Renamed all prefixes to include the major version

This is needed to allow compilation of multiple versions in the same
binary. Also note that the FUSE testing was removed because of related
name issues.

./scripts/prefix.py lfs2

.gitignore

@@ -0,0 +1,9 @@
+# Compilation output
+*.o
+*.d
+*.a
+
+# Testing things
+blocks/
+lfs2
+test.c

.travis.yml

@@ -1,14 +1,197 @@
+# Environment variables
+env:
+  global:
+    - CFLAGS=-Werror
+
+# Common test script
 script:
-    # make sure example can at least compile
+  # make sure example can at least compile
-    - sed -n '/``` c/,/```/{/```/d; p;}' README.md > test.c &&
+  - sed -n '/``` c/,/```/{/```/d; p;}' README.md > test.c &&
-      CFLAGS='
+    make all CFLAGS+="
         -Duser_provided_block_device_read=NULL
         -Duser_provided_block_device_prog=NULL
         -Duser_provided_block_device_erase=NULL
         -Duser_provided_block_device_sync=NULL
-        -include stdio.h -Werror' make all size
+        -include stdio.h"
 
-    # run tests
+  # run tests
-    - CFLAGS="-DLFS_READ_SIZE=16  -DLFS_PROG_SIZE=16"  make test
+  - make test QUIET=1
-    - CFLAGS="-DLFS_READ_SIZE=1   -DLFS_PROG_SIZE=1"   make test
+
-    - CFLAGS="-DLFS_READ_SIZE=512 -DLFS_PROG_SIZE=512" make test
+  # run tests with a few different configurations
+  - make test QUIET=1 CFLAGS+="-DLFS2_READ_SIZE=1      -DLFS2_CACHE_SIZE=4"
+  - make test QUIET=1 CFLAGS+="-DLFS2_READ_SIZE=512    -DLFS2_CACHE_SIZE=512 -DLFS2_BLOCK_CYCLES=16"
+  - make test QUIET=1 CFLAGS+="-DLFS2_BLOCK_COUNT=1023 -DLFS2_LOOKAHEAD_SIZE=256"
+
+  - make clean test QUIET=1 CFLAGS+="-DLFS2_INLINE_MAX=0"
+  - make clean test QUIET=1 CFLAGS+="-DLFS2_NO_INTRINSICS"
+
+  # compile and find the code size with the smallest configuration
+  - make clean size
+        OBJ="$(ls lfs2*.o | tr '\n' ' ')"
+        CFLAGS+="-DLFS2_NO_ASSERT -DLFS2_NO_DEBUG -DLFS2_NO_WARN -DLFS2_NO_ERROR"
+        | tee sizes
+
+  # update status if we succeeded, compare with master if possible
+  - |
+    if [ "$TRAVIS_TEST_RESULT" -eq 0 ]
+    then
+        CURR=$(tail -n1 sizes | awk '{print $1}')
+        PREV=$(curl -u $GEKY_BOT_STATUSES https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/master \
+            | jq -re "select(.sha != \"$TRAVIS_COMMIT\")
+                | .statuses[] | select(.context == \"$STAGE/$NAME\").description
+                | capture(\"code size is (?<size>[0-9]+)\").size" \
+            || echo 0)
+
+        STATUS="Passed, code size is ${CURR}B"
+        if [ "$PREV" -ne 0 ]
+        then
+            STATUS="$STATUS ($(python -c "print '%+.2f' % (100*($CURR-$PREV)/$PREV.0)")%)"
+        fi
+    fi
+
+# CI matrix
+jobs:
+  include:
+    # native testing
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-x86
+
+    # cross-compile with ARM (thumb mode)
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-arm
+        - CC="arm-linux-gnueabi-gcc --static -mthumb"
+        - EXEC="qemu-arm"
+      install:
+        - sudo apt-get install gcc-arm-linux-gnueabi qemu-user
+        - arm-linux-gnueabi-gcc --version
+        - qemu-arm -version
+
+    # cross-compile with PowerPC
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-powerpc
+        - CC="powerpc-linux-gnu-gcc --static"
+        - EXEC="qemu-ppc"
+      install:
+        - sudo apt-get install gcc-powerpc-linux-gnu qemu-user
+        - powerpc-linux-gnu-gcc --version
+        - qemu-ppc -version
+
+    # cross-compile with MIPS
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-mips
+        - CC="mips-linux-gnu-gcc --static"
+        - EXEC="qemu-mips"
+      install:
+        - sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu/ xenial main universe"
+        - sudo apt-get -qq update
+        - sudo apt-get install gcc-mips-linux-gnu qemu-user
+        - mips-linux-gnu-gcc --version
+        - qemu-mips -version
+
+      # Automatically update releases
+    - stage: deploy
+      env:
+        - STAGE=deploy
+        - NAME=deploy
+      script:
+        # Find version defined in lfs2.h
+        - LFS2_VERSION=$(grep -ox '#define LFS2_VERSION .*' lfs2.h | cut -d ' ' -f3)
+        - LFS2_VERSION_MAJOR=$((0xffff & ($LFS2_VERSION >> 16)))
+        - LFS2_VERSION_MINOR=$((0xffff & ($LFS2_VERSION >>  0)))
+        # Grab latests patch from repo tags, default to 0, needs finagling to get past github's pagination api
+        - PREV_URL=https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs/tags/v$LFS2_VERSION_MAJOR.$LFS2_VERSION_MINOR.
+        - PREV_URL=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" -I
+                | sed -n '/^Link/{s/.*<\(.*\)>; rel="last"/\1/;p;q0};$q1'
+                || echo $PREV_URL)
+        - LFS2_VERSION_PATCH=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL"
+                | jq 'map(.ref | match("\\bv.*\\..*\\.(.*)$";"g")
+                    .captures[].string | tonumber) | max + 1'
+                || echo 0)
+        # We have our new version
+        - LFS2_VERSION="v$LFS2_VERSION_MAJOR.$LFS2_VERSION_MINOR.$LFS2_VERSION_PATCH"
+        - echo "VERSION $LFS2_VERSION"
+        - |
+          # Check that we're the most recent commit
+          CURRENT_COMMIT=$(curl -f -u "$GEKY_BOT_RELEASES" \
+                https://api.github.com/repos/$TRAVIS_REPO_SLUG/commits/master \
+                | jq -re '.sha')
+          if [ "$TRAVIS_COMMIT" == "$CURRENT_COMMIT" ]
+          then
+            # Create a simple tag
+            curl -f -u "$GEKY_BOT_RELEASES" -X POST \
+                https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs \
+                -d "{
+                    \"ref\": \"refs/tags/$LFS2_VERSION\",
+                    \"sha\": \"$TRAVIS_COMMIT\"
+                }"
+            # Minor release?
+            if [[ "$LFS2_VERSION" == *.0 ]]
+            then
+              # Build release notes
+              PREV=$(git tag --sort=-v:refname -l "v*.0" | head -1)
+              if [ ! -z "$PREV" ]
+              then
+                  echo "PREV $PREV"
+                  CHANGES=$'### Changes\n\n'$( \
+                      git log --oneline $PREV.. --grep='^Merge' --invert-grep)
+                  printf "CHANGES\n%s\n\n" "$CHANGES"
+              fi
+              # Create the release
+              curl -f -u "$GEKY_BOT_RELEASES" -X POST \
+                  https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases \
+                  -d "{
+                      \"tag_name\": \"$LFS2_VERSION\",
+                      \"name\": \"${LFS2_VERSION%.0}\",
+                      \"draft\": true,
+                      \"body\": $(jq -sR '.' <<< "$CHANGES")
+                  }"
+            fi
+          fi
+
+# Manage statuses
+before_install:
+  - |
+    curl -u $GEKY_BOT_STATUSES -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"pending\",
+            \"description\": \"${STATUS:-In progress}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+after_failure:
+  - |
+    curl -u $GEKY_BOT_STATUSES -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"failure\",
+            \"description\": \"${STATUS:-Failed}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+after_success:
+  - |
+    curl -u $GEKY_BOT_STATUSES -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"success\",
+            \"description\": \"${STATUS:-Passed}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+# Job control
+stages:
+    - name: test
+    - name: deploy
+      if: branch = master AND type = push

DESIGN.md

@@ -1,6 +1,6 @@
 ## The design of the little filesystem
 
-The littlefs is a little fail-safe filesystem designed for embedded systems.
+A little fail-safe filesystem designed for embedded systems.
 
 ```
    | | |     .---._____
@@ -16,9 +16,9 @@ more about filesystem design by tackling the relative unsolved problem of
 managing a robust filesystem resilient to power loss on devices
 with limited RAM and ROM.
 
-The embedded systems the littlefs is targeting are usually 32bit
+The embedded systems the littlefs is targeting are usually 32 bit
-microcontrollers with around 32Kbytes of RAM and 512Kbytes of ROM. These are
+microcontrollers with around 32KB of RAM and 512KB of ROM. These are
-often paired with SPI NOR flash chips with about 4Mbytes of flash storage.
+often paired with SPI NOR flash chips with about 4MB of flash storage.
 
 Flash itself is a very interesting piece of technology with quite a bit of
 nuance. Unlike most other forms of storage, writing to flash requires two
@@ -27,22 +27,23 @@ cheap, and can be very granular. For NOR flash specifically, byte-level
 programs are quite common. Erasing, however, requires an expensive operation
 that forces the state of large blocks of memory to reset in a destructive
 reaction that gives flash its name. The [Wikipedia entry](https://en.wikipedia.org/wiki/Flash_memory)
-has more information if you are interesting in how this works.
+has more information if you are interested in how this works.
 
 This leaves us with an interesting set of limitations that can be simplified
 to three strong requirements:
 
-1. **Fail-safe** - This is actually the main goal of the littlefs and the focus
+1. **Power-loss resilient** - This is the main goal of the littlefs and the
-   of this project. Embedded systems are usually designed without a shutdown
+   focus of this project.
-   routine and a notable lack of user interface for recovery, so filesystems
+
-   targeting embedded systems should be prepared to lose power an any given
+   Embedded systems are usually designed without a shutdown routine and a
-   time.
+   notable lack of user interface for recovery, so filesystems targeting
+   embedded systems must be prepared to lose power at any given time.
 
    Despite this state of things, there are very few embedded filesystems that
-   handle power loss in a reasonable manner, and can become corrupted if the
+   handle power loss in a reasonable manner, and most can become corrupted if
-   user is unlucky enough.
+   the user is unlucky enough.
 
-2. **Wear awareness** - Due to the destructive nature of flash, most flash
+2. **Wear leveling** - Due to the destructive nature of flash, most flash
    chips have a limited number of erase cycles, usually in the order of around
    100,000 erases per block for NOR flash. Filesystems that don't take wear
    into account can easily burn through blocks used to store frequently updated
@@ -52,7 +53,8 @@ to three strong requirements:
    which stores a file allocation table (FAT) at a specific offset from the
    beginning of disk. Every block allocation will update this table, and after
    100,000 updates, the block will likely go bad, rendering the filesystem
-   unusable even if there are many more erase cycles available on the storage.
+   unusable even if there are many more erase cycles available on the storage
+   as a whole.
 
 3. **Bounded RAM/ROM** - Even with the design difficulties presented by the
    previous two limitations, we have already seen several flash filesystems
@@ -72,33 +74,32 @@ to three strong requirements:
 
 ## Existing designs?
 
-There are of course, many different existing filesystem. Heres a very rough
+There are of course, many different existing filesystem. Here is a very rough
 summary of the general ideas behind some of them.
 
 Most of the existing filesystems fall into the one big category of filesystem
 designed in the early days of spinny magnet disks. While there is a vast amount
 of interesting technology and ideas in this area, the nature of spinny magnet
-disks encourage properties such as grouping writes near each other, that don't
+disks encourage properties, such as grouping writes near each other, that don't
 make as much sense on recent storage types. For instance, on flash, write
-locality is not as important and can actually increase wear destructively.
+locality is not important and can actually increase wear.
 
 One of the most popular designs for flash filesystems is called the
 [logging filesystem](https://en.wikipedia.org/wiki/Log-structured_file_system).
 The flash filesystems [jffs](https://en.wikipedia.org/wiki/JFFS)
-and [yaffs](https://en.wikipedia.org/wiki/YAFFS) are good examples. In
+and [yaffs](https://en.wikipedia.org/wiki/YAFFS) are good examples. In a
-logging filesystem, data is not store in a data structure on disk, but instead
+logging filesystem, data is not stored in a data structure on disk, but instead
 the changes to the files are stored on disk. This has several neat advantages,
-such as the fact that the data is written in a cyclic log format naturally
+such as the fact that the data is written in a cyclic log format and naturally
 wear levels as a side effect. And, with a bit of error detection, the entire
 filesystem can easily be designed to be resilient to power loss. The
-journalling component of most modern day filesystems is actually a reduced
+journaling component of most modern day filesystems is actually a reduced
 form of a logging filesystem. However, logging filesystems have a difficulty
 scaling as the size of storage increases. And most filesystems compensate by
-caching large parts of the filesystem in RAM, a strategy that is unavailable
+caching large parts of the filesystem in RAM, a strategy that is inappropriate
 for embedded systems.
 
-Another interesting filesystem design technique that the littlefs borrows the
+Another interesting filesystem design technique is that of [copy-on-write (COW)](https://en.wikipedia.org/wiki/Copy-on-write).
-most from, is the [copy-on-write (COW)](https://en.wikipedia.org/wiki/Copy-on-write).
 A good example of this is the [btrfs](https://en.wikipedia.org/wiki/Btrfs)
 filesystem. COW filesystems can easily recover from corrupted blocks and have
 natural protection against power loss. However, if they are not designed with
@@ -108,14 +109,14 @@ where the COW data structures are synchronized.
 ## Metadata pairs
 
 The core piece of technology that provides the backbone for the littlefs is
-the concept of metadata pairs. The key idea here, is that any metadata that
+the concept of metadata pairs. The key idea here is that any metadata that
 needs to be updated atomically is stored on a pair of blocks tagged with
 a revision count and checksum. Every update alternates between these two
 pairs, so that at any time there is always a backup containing the previous
 state of the metadata.
 
 Consider a small example where each metadata pair has a revision count,
-a number as data, and the xor of the block as a quick checksum. If
+a number as data, and the XOR of the block as a quick checksum. If
 we update the data to a value of 9, and then to a value of 5, here is
 what the pair of blocks may look like after each update:
 ```
@@ -131,7 +132,7 @@ what the pair of blocks may look like after each update:
 After each update, we can find the most up to date value of data by looking
 at the revision count.
 
-Now consider what the blocks may look like if we suddenly loss power while
+Now consider what the blocks may look like if we suddenly lose power while
 changing the value of data to 5:
 ```
   block 1   block 2        block 1   block 2        block 1   block 2
@@ -150,19 +151,19 @@ check our checksum we notice that block 1 was corrupted. So we fall back to
 block 2 and use the value 9.
 
 Using this concept, the littlefs is able to update metadata blocks atomically.
-There are a few other tweaks, such as using a 32bit crc and using sequence
+There are a few other tweaks, such as using a 32 bit CRC and using sequence
 arithmetic to handle revision count overflow, but the basic concept
 is the same. These metadata pairs define the backbone of the littlefs, and the
 rest of the filesystem is built on top of these atomic updates.
 
-## Files
+## Non-meta data
 
 Now, the metadata pairs do come with some drawbacks. Most notably, each pair
 requires two blocks for each block of data. I'm sure users would be very
 unhappy if their storage was suddenly cut in half! Instead of storing
 everything in these metadata blocks, the littlefs uses a COW data structure
 for files which is in turn pointed to by a metadata block. When
-we update a file, we create a copies of any blocks that are modified until
+we update a file, we create copies of any blocks that are modified until
 the metadata blocks are updated with the new copy. Once the metadata block
 points to the new copy, we deallocate the old blocks that are no longer in use.
 
@@ -185,7 +186,7 @@ Here is what updating a one-block file may look like:
             update data in file        update metadata pair
 ```
 
-It doesn't matter if we lose power while writing block 5 with the new data,
+It doesn't matter if we lose power while writing new data to block 5,
 since the old data remains unmodified in block 4. This example also
 highlights how the atomic updates of the metadata blocks provide a
 synchronization barrier for the rest of the littlefs.
@@ -200,14 +201,14 @@ Now we could just leave files here, copying the entire file on write
 provides the synchronization without the duplicated memory requirements
 of the metadata blocks. However, we can do a bit better.
 
-## CTZ linked-lists
+## CTZ skip-lists
 
 There are many different data structures for representing the actual
 files in filesystems. Of these, the littlefs uses a rather unique [COW](https://upload.wikimedia.org/wikipedia/commons/0/0c/Cow_female_black_white.jpg)
 data structure that allows the filesystem to reuse unmodified parts of the
 file without additional metadata pairs.
 
-First lets consider storing files in a simple linked-list. What happens when
+First lets consider storing files in a simple linked-list. What happens when we
 append a block? We have to change the last block in the linked-list to point
 to this new block, which means we have to copy out the last block, and change
 the second-to-last block, and then the third-to-last, and so on until we've
@@ -224,12 +225,12 @@ Exhibit A: A linked-list
 
 To get around this, the littlefs, at its heart, stores files backwards. Each
 block points to its predecessor, with the first block containing no pointers.
-If you think about this, it makes a bit of sense. Appending blocks just point
+If you think about for a while, it starts to make a bit of sense. Appending
-to their predecessor and no other blocks need to be updated. If we update
+blocks just point to their predecessor and no other blocks need to be updated.
-a block in the middle, we will need to copy out the blocks that follow,
+If we update a block in the middle, we will need to copy out the blocks that
-but can reuse the blocks before the modified block. Since most file operations
+follow, but can reuse the blocks before the modified block. Since most file
-either reset the file each write or append to files, this design avoids
+operations either reset the file each write or append to files, this design
-copying the file in the most common cases.
+avoids copying the file in the most common cases.
 
 ```
 Exhibit B: A backwards linked-list
@@ -241,24 +242,24 @@ Exhibit B: A backwards linked-list
 ```
 
 However, a backwards linked-list does come with a rather glaring problem.
-Iterating over a file _in order_ has a runtime of O(n^2). Gah! A quadratic
+Iterating over a file _in order_ has a runtime cost of O(n^2). Gah! A quadratic
-runtime to just _read_ a file? That's awful. Keep in mind reading files are
+runtime to just _read_ a file? That's awful. Keep in mind reading files is
 usually the most common filesystem operation.
 
 To avoid this problem, the littlefs uses a multilayered linked-list. For
-every block that is divisible by a power of two, the block contains an
+every nth block where n is divisible by 2^x, the block contains a pointer
-additional pointer that points back by that power of two. Another way of
+to block n-2^x. So each block contains anywhere from 1 to log2(n) pointers
-thinking about this design is that there are actually many linked-lists
+that skip to various sections of the preceding list. If you're familiar with
-threaded together, with each linked-lists skipping an increasing number
+data-structures, you may have recognized that this is a type of deterministic
-of blocks. If you're familiar with data-structures, you may have also
+skip-list.
-recognized that this is a deterministic skip-list.
 
-To find the power of two factors efficiently, we can use the instruction
+The name comes from the use of the
-[count trailing zeros (CTZ)](https://en.wikipedia.org/wiki/Count_trailing_zeros),
+[count trailing zeros (CTZ)](https://en.wikipedia.org/wiki/Count_trailing_zeros)
-which is where this linked-list's name comes from.
+instruction, which allows us to calculate the power-of-two factors efficiently.
+For a given block n, the block contains ctz(n)+1 pointers.
 
 ```
-Exhibit C: A backwards CTZ linked-list
+Exhibit C: A backwards CTZ skip-list
 .--------.  .--------.  .--------.  .--------.  .--------.  .--------.
 | data 0 |<-| data 1 |<-| data 2 |<-| data 3 |<-| data 4 |<-| data 5 |
 |        |<-|        |--|        |<-|        |--|        |  |        |
@@ -266,6 +267,9 @@ Exhibit C: A backwards CTZ linked-list
 '--------'  '--------'  '--------'  '--------'  '--------'  '--------'
 ```
 
+The additional pointers allow us to navigate the data-structure on disk
+much more efficiently than in a singly linked-list.
+
 Taking exhibit C for example, here is the path from data block 5 to data
 block 1. You can see how data block 3 was completely skipped:
 ```
@@ -285,15 +289,132 @@ The path to data block 0 is even more quick, requiring only two jumps:
 '--------'  '--------'  '--------'  '--------'  '--------'  '--------'
 ```
 
-The CTZ linked-list has quite a few interesting properties. All of the pointers
+We can find the runtime complexity by looking at the path to any block from
-in the block can be found by just knowing the index in the list of the current
+the block containing the most pointers. Every step along the path divides
-block, and, with a bit of math, the amortized overhead for the linked-list is
+the search space for the block in half. This gives us a runtime of O(log n).
-only two pointers per block.  Most importantly, the CTZ linked-list has a
+To get to the block with the most pointers, we can perform the same steps
-worst case lookup runtime of O(logn), which brings the runtime of reading a
+backwards, which puts the runtime at O(2 log n) = O(log n). The interesting
-file down to O(n logn). Given that the constant runtime is divided by the
+part about this data structure is that this optimal path occurs naturally
-amount of data we can store in a block, this is pretty reasonable.
+if we greedily choose the pointer that covers the most distance without passing
+our target block.
 
-Here is what it might look like to update a file stored with a CTZ linked-list:
+So now we have a representation of files that can be appended trivially with
+a runtime of O(1), and can be read with a worst case runtime of O(n log n).
+Given that the the runtime is also divided by the amount of data we can store
+in a block, this is pretty reasonable.
+
+Unfortunately, the CTZ skip-list comes with a few questions that aren't
+straightforward to answer. What is the overhead? How do we handle more
+pointers than we can store in a block? How do we store the skip-list in
+a directory entry?
+
+One way to find the overhead per block is to look at the data structure as
+multiple layers of linked-lists. Each linked-list skips twice as many blocks
+as the previous linked-list. Another way of looking at it is that each 
+linked-list uses half as much storage per block as the previous linked-list.
+As we approach infinity, the number of pointers per block forms a geometric
+series. Solving this geometric series gives us an average of only 2 pointers
+per block.
+
+![overhead_per_block](https://latex.codecogs.com/svg.latex?%5Clim_%7Bn%5Cto%5Cinfty%7D%5Cfrac%7B1%7D%7Bn%7D%5Csum_%7Bi%3D0%7D%5E%7Bn%7D%5Cleft%28%5Ctext%7Bctz%7D%28i%29&plus;1%5Cright%29%20%3D%20%5Csum_%7Bi%3D0%7D%5Cfrac%7B1%7D%7B2%5Ei%7D%20%3D%202)
+
+Finding the maximum number of pointers in a block is a bit more complicated,
+but since our file size is limited by the integer width we use to store the
+size, we can solve for it. Setting the overhead of the maximum pointers equal
+to the block size we get the following equation. Note that a smaller block size
+results in more pointers, and a larger word width results in larger pointers.
+
+![maximum overhead](https://latex.codecogs.com/svg.latex?B%20%3D%20%5Cfrac%7Bw%7D%7B8%7D%5Cleft%5Clceil%5Clog_2%5Cleft%28%5Cfrac%7B2%5Ew%7D%7BB-2%5Cfrac%7Bw%7D%7B8%7D%7D%5Cright%29%5Cright%5Crceil)
+
+where:  
+B = block size in bytes  
+w = word width in bits  
+
+Solving the equation for B gives us the minimum block size for various word
+widths:  
+32 bit CTZ skip-list = minimum block size of 104 bytes  
+64 bit CTZ skip-list = minimum block size of 448 bytes  
+
+Since littlefs uses a 32 bit word size, we are limited to a minimum block
+size of 104 bytes. This is a perfectly reasonable minimum block size, with most
+block sizes starting around 512 bytes. So we can avoid additional logic to
+avoid overflowing our block's capacity in the CTZ skip-list.
+
+So, how do we store the skip-list in a directory entry? A naive approach would
+be to store a pointer to the head of the skip-list, the length of the file
+in bytes, the index of the head block in the skip-list, and the offset in the
+head block in bytes. However this is a lot of information, and we can observe
+that a file size maps to only one block index + offset pair. So it should be
+sufficient to store only the pointer and file size.
+
+But there is one problem, calculating the block index + offset pair from a
+file size doesn't have an obvious implementation.
+
+We can start by just writing down an equation. The first idea that comes to
+mind is to just use a for loop to sum together blocks until we reach our
+file size. We can write this equation as a summation:
+
+![summation1](https://latex.codecogs.com/svg.latex?N%20%3D%20%5Csum_i%5En%5Cleft%5BB-%5Cfrac%7Bw%7D%7B8%7D%5Cleft%28%5Ctext%7Bctz%7D%28i%29&plus;1%5Cright%29%5Cright%5D)
+
+where:  
+B = block size in bytes  
+w = word width in bits  
+n = block index in skip-list  
+N = file size in bytes  
+
+And this works quite well, but is not trivial to calculate. This equation
+requires O(n) to compute, which brings the entire runtime of reading a file
+to O(n^2 log n). Fortunately, the additional O(n) does not need to touch disk,
+so it is not completely unreasonable. But if we could solve this equation into
+a form that is easily computable, we can avoid a big slowdown.
+
+Unfortunately, the summation of the CTZ instruction presents a big challenge.
+How would you even begin to reason about integrating a bitwise instruction?
+Fortunately, there is a powerful tool I've found useful in these situations:
+The [On-Line Encyclopedia of Integer Sequences (OEIS)](https://oeis.org/).
+If we work out the first couple of values in our summation, we find that CTZ
+maps to [A001511](https://oeis.org/A001511), and its partial summation maps
+to [A005187](https://oeis.org/A005187), and surprisingly, both of these
+sequences have relatively trivial equations! This leads us to a rather
+unintuitive property:
+
+![mindblown](https://latex.codecogs.com/svg.latex?%5Csum_i%5En%5Cleft%28%5Ctext%7Bctz%7D%28i%29&plus;1%5Cright%29%20%3D%202n-%5Ctext%7Bpopcount%7D%28n%29)
+
+where:  
+ctz(x) = the number of trailing bits that are 0 in x  
+popcount(x) = the number of bits that are 1 in x  
+
+It's a bit bewildering that these two seemingly unrelated bitwise instructions
+are related by this property. But if we start to dissect this equation we can
+see that it does hold. As n approaches infinity, we do end up with an average
+overhead of 2 pointers as we find earlier. And popcount seems to handle the
+error from this average as it accumulates in the CTZ skip-list.
+
+Now we can substitute into the original equation to get a trivial equation
+for a file size:
+
+![summation2](https://latex.codecogs.com/svg.latex?N%20%3D%20Bn%20-%20%5Cfrac%7Bw%7D%7B8%7D%5Cleft%282n-%5Ctext%7Bpopcount%7D%28n%29%5Cright%29)
+
+Unfortunately, we're not quite done. The popcount function is non-injective,
+so we can only find the file size from the block index, not the other way
+around. However, we can solve for an n' block index that is greater than n
+with an error bounded by the range of the popcount function. We can then
+repeatedly substitute this n' into the original equation until the error
+is smaller than the integer division. As it turns out, we only need to
+perform this substitution once. Now we directly calculate our block index:
+
+![formulaforn](https://latex.codecogs.com/svg.latex?n%20%3D%20%5Cleft%5Clfloor%5Cfrac%7BN-%5Cfrac%7Bw%7D%7B8%7D%5Cleft%28%5Ctext%7Bpopcount%7D%5Cleft%28%5Cfrac%7BN%7D%7BB-2%5Cfrac%7Bw%7D%7B8%7D%7D-1%5Cright%29&plus;2%5Cright%29%7D%7BB-2%5Cfrac%7Bw%7D%7B8%7D%7D%5Cright%5Crfloor)
+
+Now that we have our block index n, we can just plug it back into the above
+equation to find the offset. However, we do need to rearrange the equation
+a bit to avoid integer overflow:
+
+![formulaforoff](https://latex.codecogs.com/svg.latex?%5Cmathit%7Boff%7D%20%3D%20N%20-%20%5Cleft%28B-2%5Cfrac%7Bw%7D%7B8%7D%5Cright%29n%20-%20%5Cfrac%7Bw%7D%7B8%7D%5Ctext%7Bpopcount%7D%28n%29)
+
+The solution involves quite a bit of math, but computers are very good at math.
+Now we can solve for both the block index and offset from the file size in O(1).
+
+Here is what it might look like to update a file stored with a CTZ skip-list:
 ```
                                       block 1   block 2
                                     .---------.---------.
@@ -367,7 +488,7 @@ v
 ## Block allocation
 
 So those two ideas provide the grounds for the filesystem. The metadata pairs
-give us directories, and the CTZ linked-lists give us files. But this leaves
+give us directories, and the CTZ skip-lists give us files. But this leaves
 one big [elephant](https://upload.wikimedia.org/wikipedia/commons/3/37/African_Bush_Elephant.jpg)
 of a question. How do we get those blocks in the first place?
 
@@ -380,16 +501,17 @@ scanned to find the most recent free list, but once the list was found the
 state of all free blocks becomes known.
 
 However, this approach had several issues:
+
 - There was a lot of nuanced logic for adding blocks to the free list without
   modifying the blocks, since the blocks remain active until the metadata is
   updated.
-- The free list had to support both additions and removals in fifo order while
+- The free list had to support both additions and removals in FIFO order while
   minimizing block erases.
 - The free list had to handle the case where the file system completely ran
   out of blocks and may no longer be able to add blocks to the free list.
 - If we used a revision count to track the most recently updated free list,
   metadata blocks that were left unmodified were ticking time bombs that would
-  cause the system to go haywire if the revision count overflowed
+  cause the system to go haywire if the revision count overflowed.
 - Every single metadata block wasted space to store these free list references.
 
 Actually, to simplify, this approach had one massive glaring issue: complexity.
@@ -419,7 +541,7 @@ would have an abhorrent runtime.
 So the littlefs compromises. It doesn't store a bitmap the size of the storage,
 but it does store a little bit-vector that contains a fixed set lookahead
 for block allocations. During a block allocation, the lookahead vector is
-checked for any free blocks, if there are none, the lookahead region jumps
+checked for any free blocks. If there are none, the lookahead region jumps
 forward and the entire filesystem is scanned for free blocks.
 
 Here's what it might look like to allocate 4 blocks on a decently busy
@@ -502,7 +624,7 @@ So, as a solution, the littlefs adopted a sort of threaded tree. Each
 directory not only contains pointers to all of its children, but also a
 pointer to the next directory. These pointers create a linked-list that
 is threaded through all of the directories in the filesystem. Since we
-only use this linked list to check for existance, the order doesn't actually
+only use this linked list to check for existence, the order doesn't actually
 matter. As an added plus, we can repurpose the pointer for the individual
 directory linked-lists and avoid using any additional space.
 
@@ -653,9 +775,17 @@ deorphan step that simply iterates through every directory in the linked-list
 and checks it against every directory entry in the filesystem to see if it
 has a parent. The deorphan step occurs on the first block allocation after
 boot, so orphans should never cause the littlefs to run out of storage
-prematurely.
+prematurely. Note that the deorphan step never needs to run in a read-only
+filesystem.
 
-And for my final trick, moving a directory:
+## The move problem
+
+Now we have a real problem. How do we move things between directories while
+remaining power resilient? Even looking at the problem from a high level,
+it seems impossible. We can update directory blocks atomically, but atomically
+updating two independent directory blocks is not an atomic operation.
+
+Here's the steps the filesystem may go through to move a directory:
 ```
          .--------.
          |root dir|-.
@@ -716,25 +846,142 @@ v
      '--------'
 ```
 
-Note that once again we don't care about the ordering of directories in the
+We can leave any orphans up to the deorphan step to collect, but that doesn't
-linked-list, so we can simply leave directories in their old positions. This
+help the case where dir A has both dir B and the root dir as parents if we
-does make the diagrams a bit hard to draw, but the littlefs doesn't really
+lose power inconveniently.
-care.
 
-It's also worth noting that once again we have an operation that isn't actually
+Initially, you might think this is fine. Dir A _might_ end up with two parents,
-atomic. After we add directory A to directory B, we could lose power, leaving
+but the filesystem will still work as intended. But then this raises the
-directory A as a part of both the root directory and directory B. However,
+question of what do we do when the dir A wears out? For other directory blocks
-there isn't anything inherent to the littlefs that prevents a directory from
+we can update the parent pointer, but for a dir with two parents we would need
-having multiple parents, so in this case, we just allow that to happen. Extra
+work out how to update both parents. And the check for multiple parents would
-care is taken to only remove a directory from the linked-list if there are
+need to be carried out for every directory, even if the directory has never
-no parents left in the filesystem.
+been moved.
+
+It also presents a bad user-experience, since the condition of ending up with
+two parents is rare, it's unlikely user-level code will be prepared. Just think
+about how a user would recover from a multi-parented directory. They can't just
+remove one directory, since remove would report the directory as "not empty".
+
+Other atomic filesystems simple COW the entire directory tree. But this
+introduces a significant bit of complexity, which leads to code size, along
+with a surprisingly expensive runtime cost during what most users assume is
+a single pointer update.
+
+Another option is to update the directory block we're moving from to point
+to the destination with a sort of predicate that we have moved if the
+destination exists. Unfortunately, the omnipresent concern of wear could
+cause any of these directory entries to change blocks, and changing the
+entry size before a move introduces complications if it spills out of
+the current directory block.
+
+So how do we go about moving a directory atomically?
+
+We rely on the improbableness of power loss.
+
+Power loss during a move is certainly possible, but it's actually relatively
+rare. Unless a device is writing to a filesystem constantly, it's unlikely that
+a power loss will occur during filesystem activity. We still need to handle
+the condition, but runtime during a power loss takes a back seat to the runtime
+during normal operations.
+
+So what littlefs does is inelegantly simple. When littlefs moves a file, it
+marks the file as "moving". This is stored as a single bit in the directory
+entry and doesn't take up much space. Then littlefs moves the directory,
+finishing with the complete remove of the "moving" directory entry.
+
+```
+         .--------.
+         |root dir|-.
+         | pair 0 | |
+.--------|        |-'
+|        '--------'
+|        .-'    '-.
+|       v          v
+|  .--------.  .--------.
+'->| dir A  |->| dir B  |
+   | pair 0 |  | pair 0 |
+   |        |  |        |
+   '--------'  '--------'
+
+|  update root directory to mark directory A as moving
+v
+
+        .----------.
+        |root dir  |-.
+        | pair 0   | |
+.-------| moving A!|-'
+|       '----------'
+|        .-'    '-.
+|       v          v
+|  .--------.  .--------.
+'->| dir A  |->| dir B  |
+   | pair 0 |  | pair 0 |
+   |        |  |        |
+   '--------'  '--------'
+
+|  update directory B to point to directory A
+v
+
+        .----------.
+        |root dir  |-.
+        | pair 0   | |
+.-------| moving A!|-'
+|       '----------'
+|    .-----'    '-.
+|    |             v
+|    |           .--------.
+|    |        .->| dir B  |
+|    |        |  | pair 0 |
+|    |        |  |        |
+|    |        |  '--------'
+|    |     .-------'
+|    v    v   |
+|  .--------. |
+'->| dir A  |-'
+   | pair 0 |
+   |        |
+   '--------'
+
+|  update root to no longer contain directory A
+v
+     .--------.
+     |root dir|-.
+     | pair 0 | |
+.----|        |-'
+|    '--------'
+|        |
+|        v
+|    .--------.
+| .->| dir B  |
+| |  | pair 0 |
+| '--|        |-.
+|    '--------' |
+|        |      |
+|        v      |
+|    .--------. |
+'--->| dir A  |-'
+     | pair 0 |
+     |        |
+     '--------'
+```
+
+Now, if we run into a directory entry that has been marked as "moved", one
+of two things is possible. Either the directory entry exists elsewhere in the
+filesystem, or it doesn't. This is a O(n) operation, but only occurs in the
+unlikely case we lost power during a move.
+
+And we can easily fix the "moved" directory entry. Since we're already scanning
+the filesystem during the deorphan step, we can also check for moved entries.
+If we find one, we either remove the "moved" marking or remove the whole entry
+if it exists elsewhere in the filesystem.
 
 ## Wear awareness
 
 So now that we have all of the pieces of a filesystem, we can look at a more
 subtle attribute of embedded storage: The wear down of flash blocks.
 
-The first concern for the littlefs, is that prefectly valid blocks can suddenly
+The first concern for the littlefs, is that perfectly valid blocks can suddenly
 become unusable. As a nice side-effect of using a COW data-structure for files,
 we can simply move on to a different block when a file write fails. All
 modifications to files are performed in copies, so we will only replace the
@@ -906,23 +1153,28 @@ develops errors and needs to be moved.
 
 ## Wear leveling
 
-The second concern for the littlefs, is that blocks in the filesystem may wear
+The second concern for the littlefs is that blocks in the filesystem may wear
 unevenly. In this situation, a filesystem may meet an early demise where
-there are no more non-corrupted blocks that aren't in use. It may be entirely
+there are no more non-corrupted blocks that aren't in use. It's common to
-possible that files were written once and left unmodified, wasting the
+have files that were written once and left unmodified, wasting the potential
-potential erase cycles of the blocks it sits on.
+erase cycles of the blocks it sits on.
 
 Wear leveling is a term that describes distributing block writes evenly to
 avoid the early termination of a flash part. There are typically two levels
 of wear leveling:
-1. Dynamic wear leveling - Blocks are distributed evenly during blocks writes.
+1. Dynamic wear leveling - Wear is distributed evenly across all **dynamic**
-   Note that the issue with write-once files still exists in this case.
+   blocks. Usually this is accomplished by simply choosing the unused block
-2. Static wear leveling - Unmodified blocks are evicted for new block writes.
+   with the lowest amount of wear. Note this does not solve the problem of
-   This provides the longest lifetime for a flash device.
+   static data.
+2. Static wear leveling - Wear is distributed evenly across all **dynamic**
+   and **static** blocks. Unmodified blocks may be evicted for new block
+   writes. This does handle the problem of static data but may lead to
+   wear amplification.
 
-Now, it's possible to use the revision count on metadata pairs to approximate
+In littlefs's case, it's possible to use the revision count on metadata pairs
-the wear of a metadata block. And combined with the COW nature of files, the
+to approximate the wear of a metadata block. And combined with the COW nature
-littlefs could provide a form of dynamic wear leveling.
+of files, littlefs could provide your usual implementation of dynamic wear
+leveling.
 
 However, the littlefs does not. This is for a few reasons. Most notably, even
 if the littlefs did implement dynamic wear leveling, this would still not
@@ -933,19 +1185,20 @@ As a flash device reaches the end of its life, the metadata blocks will
 naturally be the first to go since they are updated most often. In this
 situation, the littlefs is designed to simply move on to another set of
 metadata blocks. This travelling means that at the end of a flash device's
-life, the filesystem will have worn the device down as evenly as a dynamic
+life, the filesystem will have worn the device down nearly as evenly as the
-wear leveling filesystem could anyways. Simply put, if the lifetime of flash
+usual dynamic wear leveling could. More aggressive wear leveling would come
-is a serious concern, static wear leveling is the only valid solution.
+with a code-size cost for marginal benefit.
 
-This is a very important takeaway to note. If your storage stack uses highly
+
-sensitive storage such as NAND flash. In most cases you are going to be better
+One important takeaway to note, if your storage stack uses highly sensitive
-off just using a [flash translation layer (FTL)](https://en.wikipedia.org/wiki/Flash_translation_layer).
+storage such as NAND flash, static wear leveling is the only valid solution.
+In most cases you are going to be better off using a full [flash translation layer (FTL)](https://en.wikipedia.org/wiki/Flash_translation_layer).
 NAND flash already has many limitations that make it poorly suited for an
 embedded system: low erase cycles, very large blocks, errors that can develop
 even during reads, errors that can develop during writes of neighboring blocks.
 Managing sensitive storage such as NAND flash is out of scope for the littlefs.
 The littlefs does have some properties that may be beneficial on top of a FTL,
-such as limiting the number of writes where possible. But if you have the
+such as limiting the number of writes where possible, but if you have the
 storage requirements that necessitate the need of NAND flash, you should have
 the RAM to match and just use an FTL or flash filesystem.
 
@@ -955,18 +1208,18 @@ So, to summarize:
 
 1. The littlefs is composed of directory blocks
 2. Each directory is a linked-list of metadata pairs
-3. These metadata pairs can be updated atomically by alternative which
+3. These metadata pairs can be updated atomically by alternating which
    metadata block is active
 4. Directory blocks contain either references to other directories or files
-5. Files are represented by copy-on-write CTZ linked-lists
+5. Files are represented by copy-on-write CTZ skip-lists which support O(1)
-6. The CTZ linked-lists support appending in O(1) and reading in O(n logn)
+   append and O(n log n) reading
-7. Blocks are allocated by scanning the filesystem for used blocks in a
+6. Blocks are allocated by scanning the filesystem for used blocks in a
-   fixed-size lookahead region is that stored in a bit-vector
+   fixed-size lookahead region that is stored in a bit-vector
-8. To facilitate scanning the filesystem, all directories are part of a
+7. To facilitate scanning the filesystem, all directories are part of a
    linked-list that is threaded through the entire filesystem
-9. If a block develops an error, the littlefs allocates a new block, and
+8. If a block develops an error, the littlefs allocates a new block, and
    moves the data and references of the old block to the new.
-10. Any case where an atomic operation is not possible, it is taken care of
+9. Any case where an atomic operation is not possible, mistakes are resolved
    by a deorphan step that occurs on the first allocation after boot
 
 That's the little filesystem. Thanks for reading!

LICENSE.md

@@ -1,165 +1,24 @@
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-damages for loss of goodwill, work stoppage, computer failure or malfunction, or
-any and all other commercial damages or losses), even if such Contributor has
-been advised of the possibility of such damages.
-
-9. Accepting Warranty or Additional Liability.
-
-While redistributing the Work or Derivative Works thereof, You may choose to
-offer, and charge a fee for, acceptance of support, warranty, indemnity, or
-other liability obligations and/or rights consistent with this License. However,
-in accepting such obligations, You may act only on Your own behalf and on Your
-sole responsibility, not on behalf of any other Contributor, and only if You
-agree to indemnify, defend, and hold each Contributor harmless for any liability
-incurred by, or claims asserted against, such Contributor by reason of your
-accepting any such warranty or additional liability.

Makefile

@@ -1,8 +1,11 @@
-TARGET = lfs
+TARGET = lfs2.a
+ifneq ($(wildcard test.c main.c),)
+override TARGET = lfs2
+endif
 
-CC = gcc
+CC ?= gcc
-AR = ar
+AR ?= ar
-SIZE = size
+SIZE ?= size
 
 SRC += $(wildcard *.c emubd/*.c)
 OBJ := $(SRC:.c=.o)
@@ -11,16 +14,19 @@ ASM := $(SRC:.c=.s)
 
 TEST := $(patsubst tests/%.sh,%,$(wildcard tests/test_*))
 
+SHELL = /bin/bash -o pipefail
+
 ifdef DEBUG
-CFLAGS += -O0 -g3
+override CFLAGS += -O0 -g3
 else
-CFLAGS += -Os
+override CFLAGS += -Os
 endif
 ifdef WORD
-CFLAGS += -m$(WORD)
+override CFLAGS += -m$(WORD)
 endif
-CFLAGS += -I.
+override CFLAGS += -I.
-CFLAGS += -std=c99 -Wall -pedantic
+override CFLAGS += -std=c99 -Wall -pedantic
+override CFLAGS += -Wshadow -Wunused-parameter -Wjump-misses-init -Wsign-compare
 
 
 all: $(TARGET)
@@ -31,14 +37,21 @@ size: $(OBJ)
 	$(SIZE) -t $^
 
 .SUFFIXES:
-test: test_format test_dirs test_files test_seek test_parallel \
+test: test_format test_dirs test_files test_seek test_truncate \
-	test_alloc test_paths test_orphan test_corrupt
+	test_entries test_interspersed test_alloc test_paths test_attrs \
+	test_move test_orphan test_corrupt
+	@rm test.c
 test_%: tests/test_%.sh
+
+ifdef QUIET
+	@./$< | sed -n '/^[-=]/p'
+else
 	./$<
+endif
 
 -include $(DEP)
 
-$(TARGET): $(OBJ)
+lfs2: $(OBJ)
 	$(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
 
 %.a: $(OBJ)

README.md

@@ -11,23 +11,17 @@ A little fail-safe filesystem designed for embedded systems.
    | | |
 ```
 
-**Fail-safe** - The littlefs is designed to work consistently with random
+**Bounded RAM/ROM** - The littlefs is designed to work with a limited amount
-power failures. During filesystem operations the storage on disk is always
+of memory. Recursion is avoided and dynamic memory is limited to configurable
-kept in a valid state. The filesystem also has strong copy-on-write garuntees.
+buffers that can be provided statically.
-When updating a file, the original file will remain unmodified until the
-file is closed, or sync is called.
 
-**Wear awareness** - While the littlefs does not implement static wear
+**Power-loss resilient** - The littlefs is designed for systems that may have
-leveling, the littlefs takes into account write errors reported by the
+random power failures. The littlefs has strong copy-on-write guarantees and
-underlying block device and uses a limited form of dynamic wear leveling
+storage on disk is always kept in a valid state.
-to manage blocks that go bad during the lifetime of the filesystem.
 
-**Bounded ram/rom** - The littlefs is designed to work in a
+**Wear leveling** - Since the most common form of embedded storage is erodible
-limited amount of memory, recursion is avoided, and dynamic memory is kept
+flash memories, littlefs provides a form of dynamic wear leveling for systems
-to a minimum. The littlefs allocates two fixed-size buffers for general
+that can not fit a full flash translation layer.
-operations, and one fixed-size buffer per file. If there is only ever one file
-in use, all memory can be provided statically and the littlefs can be used
-in a system without dynamic memory.
 
 ## Example
 
@@ -36,14 +30,14 @@ main runs. The program can be interrupted at any time without losing track
 of how many times it has been booted and without corrupting the filesystem:
 
 ``` c
-#include "lfs.h"
+#include "lfs2.h"
 
 // variables used by the filesystem
-lfs_t lfs;
+lfs2_t lfs2;
-lfs_file_t file;
+lfs2_file_t file;
 
 // configuration of the filesystem is provided by this struct
-const struct lfs_config cfg = {
+const struct lfs2_config cfg = {
     // block device operations
     .read  = user_provided_block_device_read,
     .prog  = user_provided_block_device_prog,
@@ -55,36 +49,37 @@ const struct lfs_config cfg = {
     .prog_size = 16,
     .block_size = 4096,
     .block_count = 128,
-    .lookahead = 128,
+    .cache_size = 16,
+    .lookahead_size = 16,
 };
 
 // entry point
 int main(void) {
     // mount the filesystem
-    int err = lfs_mount(&lfs, &cfg);
+    int err = lfs2_mount(&lfs2, &cfg);
 
     // reformat if we can't mount the filesystem
     // this should only happen on the first boot
     if (err) {
-        lfs_format(&lfs, &cfg);
+        lfs2_format(&lfs2, &cfg);
-        lfs_mount(&lfs, &cfg);
+        lfs2_mount(&lfs2, &cfg);
     }
 
     // read current count
     uint32_t boot_count = 0;
-    lfs_file_open(&lfs, &file, "boot_count", LFS_O_RDWR | LFS_O_CREAT);
+    lfs2_file_open(&lfs2, &file, "boot_count", LFS2_O_RDWR | LFS2_O_CREAT);
-    lfs_file_read(&lfs, &file, &boot_count, sizeof(boot_count));
+    lfs2_file_read(&lfs2, &file, &boot_count, sizeof(boot_count));
 
     // update boot count
     boot_count += 1;
-    lfs_file_rewind(&lfs, &file);
+    lfs2_file_rewind(&lfs2, &file);
-    lfs_file_write(&lfs, &file, &boot_count, sizeof(boot_count));
+    lfs2_file_write(&lfs2, &file, &boot_count, sizeof(boot_count));
 
     // remember the storage is not updated until the file is closed successfully
-    lfs_file_close(&lfs, &file);
+    lfs2_file_close(&lfs2, &file);
 
     // release any resources we were using
-    lfs_unmount(&lfs);
+    lfs2_unmount(&lfs2);
 
     // print the boot count
     printf("boot_count: %d\n", boot_count);
@@ -94,51 +89,105 @@ int main(void) {
 ## Usage
 
 Detailed documentation (or at least as much detail as is currently available)
-can be cound in the comments in [lfs.h](lfs.h).
+can be found in the comments in [lfs2.h](lfs2.h).
 
-As you may have noticed, the littlefs takes in a configuration structure that
+As you may have noticed, littlefs takes in a configuration structure that
 defines how the filesystem operates. The configuration struct provides the
 filesystem with the block device operations and dimensions, tweakable
 parameters that tradeoff memory usage for performance, and optional
 static buffers if the user wants to avoid dynamic memory.
 
-The state of the littlefs is stored in the `lfs_t` type which is left up
+The state of the littlefs is stored in the `lfs2_t` type which is left up
 to the user to allocate, allowing multiple filesystems to be in use
-simultaneously. With the `lfs_t` and configuration struct, a user can either
+simultaneously. With the `lfs2_t` and configuration struct, a user can
 format a block device or mount the filesystem.
 
-Once mounted, the littlefs provides a full set of posix-like file and
+Once mounted, the littlefs provides a full set of POSIX-like file and
 directory functions, with the deviation that the allocation of filesystem
-structures must be provided by the user. An important addition is that
+structures must be provided by the user.
-no file updates will actually be written to disk until a sync or close
+
-is called.
+All POSIX operations, such as remove and rename, are atomic, even in event
+of power-loss. Additionally, no file updates are actually committed to the
+filesystem until sync or close is called on the file.
 
 ## Other notes
 
 All littlefs have the potential to return a negative error code. The errors
-can be either one of those found in the `enum lfs_error` in [lfs.h](lfs.h),
+can be either one of those found in the `enum lfs2_error` in [lfs2.h](lfs2.h),
 or an error returned by the user's block device operations.
 
-It should also be noted that the littlefs does not do anything to insure
+In the configuration struct, the `prog` and `erase` function provided by the
-that the data written to disk is machine portable. It should be fine as
+user may return a `LFS2_ERR_CORRUPT` error if the implementation already can
-long as the machines involved share endianness and don't have really
+detect corrupt blocks. However, the wear leveling does not depend on the return
-strange padding requirements. If the question does come up, the littlefs
+code of these functions, instead all data is read back and checked for
-metadata should be stored on disk in little-endian format.
+integrity.
 
-## Design
+If your storage caches writes, make sure that the provided `sync` function
+flushes all the data to memory and ensures that the next read fetches the data
+from memory, otherwise data integrity can not be guaranteed. If the `write`
+function does not perform caching, and therefore each `read` or `write` call
+hits the memory, the `sync` function can simply return 0.
 
-the littlefs was developed with the goal of learning more about filesystem
+## Reference material
-design by tackling the relative unsolved problem of managing a robust
+
-filesystem resilient to power loss on devices with limited RAM and ROM.
+[DESIGN.md](DESIGN.md) - DESIGN.md contains a fully detailed dive into how
-More detail on the solutions and tradeoffs incorporated into this filesystem
+littlefs actually works. I would encourage you to read it since the
-can be found in [DESIGN.md](DESIGN.md).
+solutions and tradeoffs at work here are quite interesting.
+
+[SPEC.md](SPEC.md) - SPEC.md contains the on-disk specification of littlefs
+with all the nitty-gritty details. Can be useful for developing tooling.
 
 ## Testing
 
-The littlefs comes with a test suite designed to run on a pc using the
+The littlefs comes with a test suite designed to run on a PC using the
-[emulated block device](emubd/lfs_emubd.h) found in the emubd directory.
+[emulated block device](emubd/lfs2_emubd.h) found in the emubd directory.
-The tests assume a linux environment and can be started with make:
+The tests assume a Linux environment and can be started with make:
 
 ``` bash
 make test
 ```
+
+## License
+
+The littlefs is provided under the [BSD-3-Clause](https://spdx.org/licenses/BSD-3-Clause.html)
+license. See [LICENSE.md](LICENSE.md) for more information. Contributions to
+this project are accepted under the same license.
+
+Individual files contain the following tag instead of the full license text.
+
+    SPDX-License-Identifier:    BSD-3-Clause
+
+This enables machine processing of license information based on the SPDX
+License Identifiers that are here available: http://spdx.org/licenses/
+
+## Related projects
+
+[Mbed OS](https://github.com/ARMmbed/mbed-os/tree/master/features/filesystem/littlefs) -
+The easiest way to get started with littlefs is to jump into [Mbed](https://os.mbed.com/),
+which already has block device drivers for most forms of embedded storage. The
+littlefs is available in Mbed OS as the [LittleFileSystem](https://os.mbed.com/docs/latest/reference/littlefilesystem.html)
+class.
+
+[littlefs-fuse](https://github.com/geky/littlefs-fuse) - A [FUSE](https://github.com/libfuse/libfuse)
+wrapper for littlefs. The project allows you to mount littlefs directly on a
+Linux machine. Can be useful for debugging littlefs if you have an SD card
+handy.
+
+[littlefs-js](https://github.com/geky/littlefs-js) - A javascript wrapper for
+littlefs. I'm not sure why you would want this, but it is handy for demos.
+You can see it in action [here](http://littlefs.geky.net/demo.html).
+
+[mklfs](https://github.com/whitecatboard/Lua-RTOS-ESP32/tree/master/components/mklfs/src) -
+A command line tool built by the [Lua RTOS](https://github.com/whitecatboard/Lua-RTOS-ESP32)
+guys for making littlefs images from a host PC. Supports Windows, Mac OS,
+and Linux.
+
+[SPIFFS](https://github.com/pellepl/spiffs) - Another excellent embedded
+filesystem for NOR flash. As a more traditional logging filesystem with full
+static wear-leveling, SPIFFS will likely outperform littlefs on small
+memories such as the internal flash on microcontrollers.
+
+[Dhara](https://github.com/dlbeer/dhara) - An interesting NAND flash
+translation layer designed for small MCUs. It offers static wear-leveling and
+power-resilience with only a fixed O(|address|) pointer structure stored on
+each block and in RAM.

SPEC.md

@@ -0,0 +1,370 @@
+## The little filesystem technical specification
+
+This is the technical specification of the little filesystem. This document
+covers the technical details of how the littlefs is stored on disk for
+introspection and tooling development. This document assumes you are
+familiar with the design of the littlefs, for more info on how littlefs
+works check out [DESIGN.md](DESIGN.md).
+
+```
+   | | |     .---._____
+  .-----.   |          |
+--|o    |---| littlefs |
+--|     |---|          |
+  '-----'   '----------'
+   | | |
+```
+
+## Some important details
+
+- The littlefs is a block-based filesystem. This is, the disk is divided into
+  an array of evenly sized blocks that are used as the logical unit of storage
+  in littlefs. Block pointers are stored in 32 bits.
+
+- There is no explicit free-list stored on disk, the littlefs only knows what
+  is in use in the filesystem.
+
+- The littlefs uses the value of 0xffffffff to represent a null block-pointer.
+
+- All values in littlefs are stored in little-endian byte order.
+
+## Directories / Metadata pairs
+
+Metadata pairs form the backbone of the littlefs and provide a system for
+atomic updates. Even the superblock is stored in a metadata pair.
+
+As their name suggests, a metadata pair is stored in two blocks, with one block
+acting as a redundant backup in case the other is corrupted. These two blocks
+could be anywhere in the disk and may not be next to each other, so any
+pointers to directory pairs need to be stored as two block pointers.
+
+Here's the layout of metadata blocks on disk:
+
+| offset | size          | description    |
+|--------|---------------|----------------|
+| 0x00   | 32 bits       | revision count |
+| 0x04   | 32 bits       | dir size       |
+| 0x08   | 64 bits       | tail pointer   |
+| 0x10   | size-16 bytes | dir entries    |
+| 0x00+s | 32 bits       | CRC            |
+
+**Revision count** - Incremented every update, only the uncorrupted
+metadata-block with the most recent revision count contains the valid metadata.
+Comparison between revision counts must use sequence comparison since the
+revision counts may overflow.
+
+**Dir size** - Size in bytes of the contents in the current metadata block,
+including the metadata-pair metadata. Additionally, the highest bit of the
+dir size may be set to indicate that the directory's contents continue on the
+next metadata-pair pointed to by the tail pointer.
+
+**Tail pointer** - Pointer to the next metadata-pair in the filesystem.
+A null pair-pointer (0xffffffff, 0xffffffff) indicates the end of the list.
+If the highest bit in the dir size is set, this points to the next
+metadata-pair in the current directory, otherwise it points to an arbitrary
+metadata-pair. Starting with the superblock, the tail-pointers form a
+linked-list containing all metadata-pairs in the filesystem.
+
+**CRC** - 32 bit CRC used to detect corruption from power-lost, from block
+end-of-life, or just from noise on the storage bus. The CRC is appended to
+the end of each metadata-block. The littlefs uses the standard CRC-32, which
+uses a polynomial of 0x04c11db7, initialized with 0xffffffff.
+
+Here's an example of a simple directory stored on disk:
+```
+(32 bits) revision count = 10                    (0x0000000a)
+(32 bits) dir size       = 154 bytes, end of dir (0x0000009a)
+(64 bits) tail pointer   = 37, 36                (0x00000025, 0x00000024)
+(32 bits) CRC            = 0xc86e3106
+
+00000000: 0a 00 00 00 9a 00 00 00 25 00 00 00 24 00 00 00  ........%...$...
+00000010: 22 08 00 03 05 00 00 00 04 00 00 00 74 65 61 22  "...........tea"
+00000020: 08 00 06 07 00 00 00 06 00 00 00 63 6f 66 66 65  ...........coffe
+00000030: 65 22 08 00 04 09 00 00 00 08 00 00 00 73 6f 64  e"...........sod
+00000040: 61 22 08 00 05 1d 00 00 00 1c 00 00 00 6d 69 6c  a"...........mil
+00000050: 6b 31 22 08 00 05 1f 00 00 00 1e 00 00 00 6d 69  k1"...........mi
+00000060: 6c 6b 32 22 08 00 05 21 00 00 00 20 00 00 00 6d  lk2"...!... ...m
+00000070: 69 6c 6b 33 22 08 00 05 23 00 00 00 22 00 00 00  ilk3"...#..."...
+00000080: 6d 69 6c 6b 34 22 08 00 05 25 00 00 00 24 00 00  milk4"...%...$..
+00000090: 00 6d 69 6c 6b 35 06 31 6e c8                    .milk5.1n.
+```
+
+A note about the tail pointer linked-list: Normally, this linked-list is
+threaded through the entire filesystem. However, after power-loss this
+linked-list may become out of sync with the rest of the filesystem.
+- The linked-list may contain a directory that has actually been removed
+- The linked-list may contain a metadata pair that has not been updated after
+  a block in the pair has gone bad.
+
+The threaded linked-list must be checked for these errors before it can be
+used reliably. Fortunately, the threaded linked-list can simply be ignored
+if littlefs is mounted read-only.
+
+## Entries
+
+Each metadata block contains a series of entries that follow a standard
+layout. An entry contains the type of the entry, along with a section for
+entry-specific data, attributes, and a name.
+
+Here's the layout of entries on disk:
+
+| offset  | size                   | description                |
+|---------|------------------------|----------------------------|
+| 0x0     | 8 bits                 | entry type                 |
+| 0x1     | 8 bits                 | entry length               |
+| 0x2     | 8 bits                 | attribute length           |
+| 0x3     | 8 bits                 | name length                |
+| 0x4     | entry length bytes     | entry-specific data        |
+| 0x4+e   | attribute length bytes | system-specific attributes |
+| 0x4+e+a | name length bytes      | entry name                 |
+
+**Entry type** - Type of the entry, currently this is limited to the following:
+- 0x11 - file entry
+- 0x22 - directory entry
+- 0x2e - superblock entry
+
+Additionally, the type is broken into two 4 bit nibbles, with the upper nibble
+specifying the type's data structure used when scanning the filesystem. The
+lower nibble clarifies the type further when multiple entries share the same
+data structure.
+
+The highest bit is reserved for marking the entry as "moved". If an entry
+is marked as "moved", the entry may also exist somewhere else in the
+filesystem. If the entry exists elsewhere, this entry must be treated as
+though it does not exist.
+
+**Entry length** - Length in bytes of the entry-specific data. This does
+not include the entry type size, attributes, or name. The full size in bytes
+of the entry is 4 + entry length + attribute length + name length.
+
+**Attribute length** - Length of system-specific attributes in bytes. Since
+attributes are system specific, there is not much guarantee on the values in
+this section, and systems are expected to work even when it is empty. See the
+[attributes](#entry-attributes) section for more details.
+
+**Name length** - Length of the entry name. Entry names are stored as UTF8,
+although most systems will probably only support ASCII. Entry names can not
+contain '/' and can not be '.' or '..' as these are a part of the syntax of
+filesystem paths.
+
+Here's an example of a simple entry stored on disk:
+```
+(8 bits)   entry type       = file     (0x11)
+(8 bits)   entry length     = 8 bytes  (0x08)
+(8 bits)   attribute length = 0 bytes  (0x00)
+(8 bits)   name length      = 12 bytes (0x0c)
+(8 bytes)  entry data       = 05 00 00 00 20 00 00 00
+(12 bytes) entry name       = smallavacado
+
+00000000: 11 08 00 0c 05 00 00 00 20 00 00 00 73 6d 61 6c  ........ ...smal
+00000010: 6c 61 76 61 63 61 64 6f                          lavacado
+```
+
+## Superblock
+
+The superblock is the anchor for the littlefs. The superblock is stored as
+a metadata pair containing a single superblock entry. It is through the
+superblock that littlefs can access the rest of the filesystem.
+
+The superblock can always be found in blocks 0 and 1, however fetching the
+superblock requires knowing the block size. The block size can be guessed by
+searching the beginning of disk for the string "littlefs", although currently
+the filesystems relies on the user providing the correct block size.
+
+The superblock is the most valuable block in the filesystem. It is updated
+very rarely, only during format or when the root directory must be moved. It
+is encouraged to always write out both superblock pairs even though it is not
+required.
+
+Here's the layout of the superblock entry:
+
+| offset | size                   | description                            |
+|--------|------------------------|----------------------------------------|
+| 0x00   | 8 bits                 | entry type (0x2e for superblock entry) |
+| 0x01   | 8 bits                 | entry length (20 bytes)                |
+| 0x02   | 8 bits                 | attribute length                       |
+| 0x03   | 8 bits                 | name length (8 bytes)                  |
+| 0x04   | 64 bits                | root directory                         |
+| 0x0c   | 32 bits                | block size                             |
+| 0x10   | 32 bits                | block count                            |
+| 0x14   | 32 bits                | version                                |
+| 0x18   | attribute length bytes | system-specific attributes             |
+| 0x18+a | 8 bytes                | magic string ("littlefs")              |
+
+**Root directory** - Pointer to the root directory's metadata pair.
+
+**Block size** - Size of the logical block size used by the filesystem.
+
+**Block count** - Number of blocks in the filesystem.
+
+**Version** - The littlefs version encoded as a 32 bit value. The upper 16 bits
+encodes the major version, which is incremented when a breaking-change is
+introduced in the filesystem specification. The lower 16 bits encodes the
+minor version, which is incremented when a backwards-compatible change is
+introduced. Non-standard Attribute changes do not change the version. This
+specification describes version 1.1 (0x00010001), which is the first version
+of littlefs.
+
+**Magic string** - The magic string "littlefs" takes the place of an entry
+name.
+
+Here's an example of a complete superblock:
+```
+(32 bits) revision count   = 3                    (0x00000003)
+(32 bits) dir size         = 52 bytes, end of dir (0x00000034)
+(64 bits) tail pointer     = 3, 2                 (0x00000003, 0x00000002)
+(8 bits)  entry type       = superblock           (0x2e)
+(8 bits)  entry length     = 20 bytes             (0x14)
+(8 bits)  attribute length = 0 bytes              (0x00)
+(8 bits)  name length      = 8 bytes              (0x08)
+(64 bits) root directory   = 3, 2                 (0x00000003, 0x00000002)
+(32 bits) block size       = 512 bytes            (0x00000200)
+(32 bits) block count      = 1024 blocks          (0x00000400)
+(32 bits) version          = 1.1                  (0x00010001)
+(8 bytes) magic string     = littlefs
+(32 bits) CRC              = 0xc50b74fa
+
+00000000: 03 00 00 00 34 00 00 00 03 00 00 00 02 00 00 00  ....4...........
+00000010: 2e 14 00 08 03 00 00 00 02 00 00 00 00 02 00 00  ................
+00000020: 00 04 00 00 01 00 01 00 6c 69 74 74 6c 65 66 73  ........littlefs
+00000030: fa 74 0b c5                                      .t..
+```
+
+## Directory entries
+
+Directories are stored in entries with a pointer to the first metadata pair
+in the directory. Keep in mind that a directory may be composed of multiple
+metadata pairs connected by the tail pointer when the highest bit in the dir
+size is set.
+
+Here's the layout of a directory entry:
+
+| offset | size                   | description                             |
+|--------|------------------------|-----------------------------------------|
+| 0x0    | 8 bits                 | entry type (0x22 for directory entries) |
+| 0x1    | 8 bits                 | entry length (8 bytes)                  |
+| 0x2    | 8 bits                 | attribute length                        |
+| 0x3    | 8 bits                 | name length                             |
+| 0x4    | 64 bits                | directory pointer                       |
+| 0xc    | attribute length bytes | system-specific attributes              |
+| 0xc+a  | name length bytes      | directory name                          |
+
+**Directory pointer** - Pointer to the first metadata pair in the directory.
+
+Here's an example of a directory entry:
+```
+(8 bits)  entry type        = directory (0x22)
+(8 bits)  entry length      = 8 bytes   (0x08)
+(8 bits)  attribute length  = 0 bytes   (0x00)
+(8 bits)  name length       = 3 bytes   (0x03)
+(64 bits) directory pointer = 5, 4      (0x00000005, 0x00000004)
+(3 bytes) name              = tea
+
+00000000: 22 08 00 03 05 00 00 00 04 00 00 00 74 65 61     "...........tea
+```
+
+## File entries
+
+Files are stored in entries with a pointer to the head of the file and the
+size of the file. This is enough information to determine the state of the
+CTZ skip-list that is being referenced.
+
+How files are actually stored on disk is a bit complicated. The full
+explanation of CTZ skip-lists can be found in [DESIGN.md](DESIGN.md#ctz-skip-lists).
+
+A terribly quick summary: For every nth block where n is divisible by 2^x,
+the block contains a pointer to block n-2^x. These pointers are stored in
+increasing order of x in each block of the file preceding the data in the
+block.
+
+The maximum number of pointers in a block is bounded by the maximum file size
+divided by the block size. With 32 bits for file size, this results in a
+minimum block size of 104 bytes.
+
+Here's the layout of a file entry:
+
+| offset | size                   | description                        |
+|--------|------------------------|------------------------------------|
+| 0x0    | 8 bits                 | entry type (0x11 for file entries) |
+| 0x1    | 8 bits                 | entry length (8 bytes)             |
+| 0x2    | 8 bits                 | attribute length                   |
+| 0x3    | 8 bits                 | name length                        |
+| 0x4    | 32 bits                | file head                          |
+| 0x8    | 32 bits                | file size                          |
+| 0xc    | attribute length bytes | system-specific attributes         |
+| 0xc+a  | name length bytes      | directory name                     |
+
+**File head** - Pointer to the block that is the head of the file's CTZ
+skip-list.
+
+**File size** - Size of file in bytes.
+
+Here's an example of a file entry:
+```
+(8 bits)   entry type       = file     (0x11)
+(8 bits)   entry length     = 8 bytes  (0x08)
+(8 bits)   attribute length = 0 bytes  (0x00)
+(8 bits)   name length      = 12 bytes (0x03)
+(32 bits)  file head        = 543      (0x0000021f)
+(32 bits)  file size        = 256 KB   (0x00040000)
+(12 bytes) name             = largeavacado
+
+00000000: 11 08 00 0c 1f 02 00 00 00 00 04 00 6c 61 72 67  ............larg
+00000010: 65 61 76 61 63 61 64 6f                          eavacado
+```
+
+## Entry attributes
+
+Each dir entry can have up to 256 bytes of system-specific attributes. Since
+these attributes are system-specific, they may not be portable between
+different systems. For this reason, all attributes must be optional. A minimal
+littlefs driver must be able to get away with supporting no attributes at all.
+
+For some level of portability, littlefs has a simple scheme for attributes.
+Each attribute is prefixes with an 8-bit type that indicates what the attribute
+is. The length of attributes may also be determined from this type. Attributes
+in an entry should be sorted based on portability, since attribute parsing
+will end when it hits the first attribute it does not understand.
+
+Each system should choose a 4-bit value to prefix all attribute types with to
+avoid conflicts with other systems. Additionally, littlefs drivers that support
+attributes should provide a "ignore attributes" flag to users in case attribute
+conflicts do occur.
+
+Attribute types prefixes with 0x0 and 0xf are currently reserved for future
+standard attributes. Standard attributes will be added to this document in
+that case.
+
+Here's an example of non-standard time attribute:
+```
+(8 bits)  attribute type  = time       (0xc1)
+(72 bits) time in seconds = 1506286115 (0x0059c81a23)
+
+00000000: c1 23 1a c8 59 00                                .#..Y.
+```
+
+Here's an example of non-standard permissions attribute:
+```
+(8 bits)  attribute type  = permissions (0xc2)
+(16 bits) permission bits = rw-rw-r--   (0x01b4)
+
+00000000: c2 b4 01                                         ...
+```
+
+Here's what a dir entry may look like with these attributes:
+```
+(8 bits)   entry type       = file         (0x11)
+(8 bits)   entry length     = 8 bytes      (0x08)
+(8 bits)   attribute length = 9 bytes      (0x09)
+(8 bits)   name length      = 12 bytes     (0x0c)
+(8 bytes)  entry data       = 05 00 00 00 20 00 00 00
+(8 bits)   attribute type   = time         (0xc1)
+(72 bits)  time in seconds  = 1506286115   (0x0059c81a23)
+(8 bits)   attribute type   = permissions  (0xc2)
+(16 bits)  permission bits  = rw-rw-r--    (0x01b4)
+(12 bytes) entry name       = smallavacado
+
+00000000: 11 08 09 0c 05 00 00 00 20 00 00 00 c1 23 1a c8  ........ ....#..
+00000010: 59 00 c2 b4 01 73 6d 61 6c 6c 61 76 61 63 61 64  Y....smallavacad
+00000020: 6f                                               o
+```

emubd/lfs2_emubd.c

@@ -0,0 +1,324 @@
+/*
+ * Block device emulated on standard files
+ *
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include "emubd/lfs2_emubd.h"
+
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <limits.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <assert.h>
+#include <stdbool.h>
+#include <inttypes.h>
+
+
+// Emulated block device utils
+static inline void lfs2_emubd_tole32(lfs2_emubd_t *emu) {
+    emu->cfg.read_size     = lfs2_tole32(emu->cfg.read_size);
+    emu->cfg.prog_size     = lfs2_tole32(emu->cfg.prog_size);
+    emu->cfg.block_size    = lfs2_tole32(emu->cfg.block_size);
+    emu->cfg.block_count   = lfs2_tole32(emu->cfg.block_count);
+
+    emu->stats.read_count  = lfs2_tole32(emu->stats.read_count);
+    emu->stats.prog_count  = lfs2_tole32(emu->stats.prog_count);
+    emu->stats.erase_count = lfs2_tole32(emu->stats.erase_count);
+
+    for (unsigned i = 0; i < sizeof(emu->history.blocks) /
+            sizeof(emu->history.blocks[0]); i++) {
+        emu->history.blocks[i] = lfs2_tole32(emu->history.blocks[i]);
+    }
+}
+
+static inline void lfs2_emubd_fromle32(lfs2_emubd_t *emu) {
+    emu->cfg.read_size     = lfs2_fromle32(emu->cfg.read_size);
+    emu->cfg.prog_size     = lfs2_fromle32(emu->cfg.prog_size);
+    emu->cfg.block_size    = lfs2_fromle32(emu->cfg.block_size);
+    emu->cfg.block_count   = lfs2_fromle32(emu->cfg.block_count);
+
+    emu->stats.read_count  = lfs2_fromle32(emu->stats.read_count);
+    emu->stats.prog_count  = lfs2_fromle32(emu->stats.prog_count);
+    emu->stats.erase_count = lfs2_fromle32(emu->stats.erase_count);
+
+    for (unsigned i = 0; i < sizeof(emu->history.blocks) /
+            sizeof(emu->history.blocks[0]); i++) {
+        emu->history.blocks[i] = lfs2_fromle32(emu->history.blocks[i]);
+    }
+}
+
+
+// Block device emulated on existing filesystem
+int lfs2_emubd_create(const struct lfs2_config *cfg, const char *path) {
+    lfs2_emubd_t *emu = cfg->context;
+    emu->cfg.read_size   = cfg->read_size;
+    emu->cfg.prog_size   = cfg->prog_size;
+    emu->cfg.block_size  = cfg->block_size;
+    emu->cfg.block_count = cfg->block_count;
+
+    // Allocate buffer for creating children files
+    size_t pathlen = strlen(path);
+    emu->path = malloc(pathlen + 1 + LFS2_NAME_MAX + 1);
+    if (!emu->path) {
+        return -ENOMEM;
+    }
+
+    strcpy(emu->path, path);
+    emu->path[pathlen] = '/';
+    emu->child = &emu->path[pathlen+1];
+    memset(emu->child, '\0', LFS2_NAME_MAX+1);
+
+    // Create directory if it doesn't exist
+    int err = mkdir(path, 0777);
+    if (err && errno != EEXIST) {
+        return -errno;
+    }
+
+    // Load stats to continue incrementing
+    snprintf(emu->child, LFS2_NAME_MAX, ".stats");
+    FILE *f = fopen(emu->path, "r");
+    if (!f) {
+        memset(&emu->stats, 0, sizeof(emu->stats));
+    } else {
+        size_t res = fread(&emu->stats, sizeof(emu->stats), 1, f);
+        lfs2_emubd_fromle32(emu);
+        if (res < 1) {
+            return -errno;
+        }
+
+        err = fclose(f);
+        if (err) {
+            return -errno;
+        }
+    }
+
+    // Load history
+    snprintf(emu->child, LFS2_NAME_MAX, ".history");
+    f = fopen(emu->path, "r");
+    if (!f) {
+        memset(&emu->history, 0, sizeof(emu->history));
+    } else {
+        size_t res = fread(&emu->history, sizeof(emu->history), 1, f);
+        lfs2_emubd_fromle32(emu);
+        if (res < 1) {
+            return -errno;
+        }
+
+        err = fclose(f);
+        if (err) {
+            return -errno;
+        }
+    }
+
+    return 0;
+}
+
+void lfs2_emubd_destroy(const struct lfs2_config *cfg) {
+    lfs2_emubd_sync(cfg);
+
+    lfs2_emubd_t *emu = cfg->context;
+    free(emu->path);
+}
+
+int lfs2_emubd_read(const struct lfs2_config *cfg, lfs2_block_t block,
+        lfs2_off_t off, void *buffer, lfs2_size_t size) {
+    lfs2_emubd_t *emu = cfg->context;
+    uint8_t *data = buffer;
+
+    // Check if read is valid
+    assert(off  % cfg->read_size == 0);
+    assert(size % cfg->read_size == 0);
+    assert(block < cfg->block_count);
+
+    // Zero out buffer for debugging
+    memset(data, 0, size);
+
+    // Read data
+    snprintf(emu->child, LFS2_NAME_MAX, "%" PRIx32, block);
+
+    FILE *f = fopen(emu->path, "rb");
+    if (!f && errno != ENOENT) {
+        return -errno;
+    }
+
+    if (f) {
+        int err = fseek(f, off, SEEK_SET);
+        if (err) {
+            return -errno;
+        }
+
+        size_t res = fread(data, 1, size, f);
+        if (res < size && !feof(f)) {
+            return -errno;
+        }
+
+        err = fclose(f);
+        if (err) {
+            return -errno;
+        }
+    }
+
+    emu->stats.read_count += 1;
+    return 0;
+}
+
+int lfs2_emubd_prog(const struct lfs2_config *cfg, lfs2_block_t block,
+        lfs2_off_t off, const void *buffer, lfs2_size_t size) {
+    lfs2_emubd_t *emu = cfg->context;
+    const uint8_t *data = buffer;
+
+    // Check if write is valid
+    assert(off  % cfg->prog_size == 0);
+    assert(size % cfg->prog_size == 0);
+    assert(block < cfg->block_count);
+
+    // Program data
+    snprintf(emu->child, LFS2_NAME_MAX, "%" PRIx32, block);
+
+    FILE *f = fopen(emu->path, "r+b");
+    if (!f) {
+        return (errno == EACCES) ? 0 : -errno;
+    }
+
+    // Check that file was erased
+    assert(f);
+
+    int err = fseek(f, off, SEEK_SET);
+    if (err) {
+        return -errno;
+    }
+
+    size_t res = fwrite(data, 1, size, f);
+    if (res < size) {
+        return -errno;
+    }
+
+    err = fseek(f, off, SEEK_SET);
+    if (err) {
+        return -errno;
+    }
+
+    uint8_t dat;
+    res = fread(&dat, 1, 1, f);
+    if (res < 1) {
+        return -errno;
+    }
+
+    err = fclose(f);
+    if (err) {
+        return -errno;
+    }
+
+    // update history and stats
+    if (block != emu->history.blocks[0]) {
+        memcpy(&emu->history.blocks[1], &emu->history.blocks[0],
+                sizeof(emu->history) - sizeof(emu->history.blocks[0]));
+        emu->history.blocks[0] = block;
+    }
+
+    emu->stats.prog_count += 1;
+    return 0;
+}
+
+int lfs2_emubd_erase(const struct lfs2_config *cfg, lfs2_block_t block) {
+    lfs2_emubd_t *emu = cfg->context;
+
+    // Check if erase is valid
+    assert(block < cfg->block_count);
+
+    // Erase the block
+    snprintf(emu->child, LFS2_NAME_MAX, "%" PRIx32, block);
+    struct stat st;
+    int err = stat(emu->path, &st);
+    if (err && errno != ENOENT) {
+        return -errno;
+    }
+
+    if (!err && S_ISREG(st.st_mode) && (S_IWUSR & st.st_mode)) {
+        err = unlink(emu->path);
+        if (err) {
+            return -errno;
+        }
+    }
+
+    if (err || (S_ISREG(st.st_mode) && (S_IWUSR & st.st_mode))) {
+        FILE *f = fopen(emu->path, "w");
+        if (!f) {
+            return -errno;
+        }
+
+        err = fclose(f);
+        if (err) {
+            return -errno;
+        }
+    }
+
+    emu->stats.erase_count += 1;
+    return 0;
+}
+
+int lfs2_emubd_sync(const struct lfs2_config *cfg) {
+    lfs2_emubd_t *emu = cfg->context;
+
+    // Just write out info/stats for later lookup
+    snprintf(emu->child, LFS2_NAME_MAX, ".config");
+    FILE *f = fopen(emu->path, "w");
+    if (!f) {
+        return -errno;
+    }
+
+    lfs2_emubd_tole32(emu);
+    size_t res = fwrite(&emu->cfg, sizeof(emu->cfg), 1, f);
+    lfs2_emubd_fromle32(emu);
+    if (res < 1) {
+        return -errno;
+    }
+
+    int err = fclose(f);
+    if (err) {
+        return -errno;
+    }
+
+    snprintf(emu->child, LFS2_NAME_MAX, ".stats");
+    f = fopen(emu->path, "w");
+    if (!f) {
+        return -errno;
+    }
+
+    lfs2_emubd_tole32(emu);
+    res = fwrite(&emu->stats, sizeof(emu->stats), 1, f);
+    lfs2_emubd_fromle32(emu);
+    if (res < 1) {
+        return -errno;
+    }
+
+    err = fclose(f);
+    if (err) {
+        return -errno;
+    }
+
+    snprintf(emu->child, LFS2_NAME_MAX, ".history");
+    f = fopen(emu->path, "w");
+    if (!f) {
+        return -errno;
+    }
+
+    lfs2_emubd_tole32(emu);
+    res = fwrite(&emu->history, sizeof(emu->history), 1, f);
+    lfs2_emubd_fromle32(emu);
+    if (res < 1) {
+        return -errno;
+    }
+
+    err = fclose(f);
+    if (err) {
+        return -errno;
+    }
+
+    return 0;
+}

emubd/lfs2_emubd.h

@@ -0,0 +1,91 @@
+/*
+ * Block device emulated on standard files
+ *
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef LFS2_EMUBD_H
+#define LFS2_EMUBD_H
+
+#include "lfs2.h"
+#include "lfs2_util.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
+// Config options
+#ifndef LFS2_EMUBD_READ_SIZE
+#define LFS2_EMUBD_READ_SIZE 1
+#endif
+
+#ifndef LFS2_EMUBD_PROG_SIZE
+#define LFS2_EMUBD_PROG_SIZE 1
+#endif
+
+#ifndef LFS2_EMUBD_ERASE_SIZE
+#define LFS2_EMUBD_ERASE_SIZE 512
+#endif
+
+#ifndef LFS2_EMUBD_TOTAL_SIZE
+#define LFS2_EMUBD_TOTAL_SIZE 524288
+#endif
+
+
+// The emu bd state
+typedef struct lfs2_emubd {
+    char *path;
+    char *child;
+
+    struct {
+        uint64_t read_count;
+        uint64_t prog_count;
+        uint64_t erase_count;
+    } stats;
+
+    struct {
+        lfs2_block_t blocks[4];
+    } history;
+
+    struct {
+        uint32_t read_size;
+        uint32_t prog_size;
+        uint32_t block_size;
+        uint32_t block_count;
+    } cfg;
+} lfs2_emubd_t;
+
+
+// Create a block device using path for the directory to store blocks
+int lfs2_emubd_create(const struct lfs2_config *cfg, const char *path);
+
+// Clean up memory associated with emu block device
+void lfs2_emubd_destroy(const struct lfs2_config *cfg);
+
+// Read a block
+int lfs2_emubd_read(const struct lfs2_config *cfg, lfs2_block_t block,
+        lfs2_off_t off, void *buffer, lfs2_size_t size);
+
+// Program a block
+//
+// The block must have previously been erased.
+int lfs2_emubd_prog(const struct lfs2_config *cfg, lfs2_block_t block,
+        lfs2_off_t off, const void *buffer, lfs2_size_t size);
+
+// Erase a block
+//
+// A block must be erased before being programmed. The
+// state of an erased block is undefined.
+int lfs2_emubd_erase(const struct lfs2_config *cfg, lfs2_block_t block);
+
+// Sync the block device
+int lfs2_emubd_sync(const struct lfs2_config *cfg);
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

emubd/lfs_emubd.c

@@ -1,242 +0,0 @@
-/*
- * Block device emulated on standard files
- *
- * Copyright (c) 2017 Christopher Haster
- * Distributed under the Apache 2.0 license
- */
-#include "emubd/lfs_emubd.h"
-
-#include <errno.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <limits.h>
-#include <dirent.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <assert.h>
-#include <stdbool.h>
-
-
-// Block device emulated on existing filesystem
-int lfs_emubd_create(const struct lfs_config *cfg, const char *path) {
-    lfs_emubd_t *emu = cfg->context;
-    emu->cfg.read_size   = cfg->read_size;
-    emu->cfg.prog_size   = cfg->prog_size;
-    emu->cfg.block_size  = cfg->block_size;
-    emu->cfg.block_count = cfg->block_count;
-
-    // Allocate buffer for creating children files
-    size_t pathlen = strlen(path);
-    emu->path = malloc(pathlen + 1 + LFS_NAME_MAX + 1);
-    if (!emu->path) {
-        return -ENOMEM;
-    }
-
-    strcpy(emu->path, path);
-    emu->path[pathlen] = '/';
-    emu->child = &emu->path[pathlen+1];
-    memset(emu->child, '\0', LFS_NAME_MAX+1);
-
-    // Create directory if it doesn't exist
-    int err = mkdir(path, 0777);
-    if (err && errno != EEXIST) {
-        return -errno;
-    }
-
-    // Load stats to continue incrementing
-    snprintf(emu->child, LFS_NAME_MAX, "stats");
-    FILE *f = fopen(emu->path, "r");
-    if (!f) {
-        return -errno;
-    }
-
-    size_t res = fread(&emu->stats, sizeof(emu->stats), 1, f);
-    if (res < 1) {
-        return -errno;
-    }
-
-    err = fclose(f);
-    if (err) {
-        return -errno;
-    }
-
-    return 0;
-}
-
-void lfs_emubd_destroy(const struct lfs_config *cfg) {
-    lfs_emubd_sync(cfg);
-
-    lfs_emubd_t *emu = cfg->context;
-    free(emu->path);
-}
-
-int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, void *buffer, lfs_size_t size) {
-    lfs_emubd_t *emu = cfg->context;
-    uint8_t *data = buffer;
-
-    // Check if read is valid
-    assert(off  % cfg->read_size == 0);
-    assert(size % cfg->read_size == 0);
-    assert(block < cfg->block_count);
-
-    // Zero out buffer for debugging
-    memset(data, 0, size);
-
-    // Read data
-    snprintf(emu->child, LFS_NAME_MAX, "%x", block);
-
-    FILE *f = fopen(emu->path, "rb");
-    if (!f && errno != ENOENT) {
-        return -errno;
-    }
-
-    if (f) {
-        int err = fseek(f, off, SEEK_SET);
-        if (err) {
-            return -errno;
-        }
-
-        size_t res = fread(data, 1, size, f);
-        if (res < size && !feof(f)) {
-            return -errno;
-        }
-
-        err = fclose(f);
-        if (err) {
-            return -errno;
-        }
-    }
-
-    emu->stats.read_count += 1;
-    return 0;
-}
-
-int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, const void *buffer, lfs_size_t size) {
-    lfs_emubd_t *emu = cfg->context;
-    const uint8_t *data = buffer;
-
-    // Check if write is valid
-    assert(off  % cfg->prog_size == 0);
-    assert(size % cfg->prog_size == 0);
-    assert(block < cfg->block_count);
-
-    // Program data
-    snprintf(emu->child, LFS_NAME_MAX, "%x", block);
-
-    FILE *f = fopen(emu->path, "r+b");
-    if (!f && errno != ENOENT) {
-        return -errno;
-    }
-
-    // Check that file was erased
-    assert(f);
-
-    int err = fseek(f, off, SEEK_SET);
-    if (err) {
-        return -errno;
-    }
-
-    size_t res = fwrite(data, 1, size, f);
-    if (res < size) {
-        return -errno;
-    }
-
-    err = fseek(f, off, SEEK_SET);
-    if (err) {
-        return -errno;
-    }
-
-    uint8_t dat;
-    res = fread(&dat, 1, 1, f);
-    if (res < 1) {
-        return -errno;
-    }
-
-    err = fclose(f);
-    if (err) {
-        return -errno;
-    }
-
-    emu->stats.prog_count += 1;
-    return 0;
-}
-
-int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    lfs_emubd_t *emu = cfg->context;
-
-    // Check if erase is valid
-    assert(block < cfg->block_count);
-
-    // Erase the block
-    snprintf(emu->child, LFS_NAME_MAX, "%x", block);
-    struct stat st;
-    int err = stat(emu->path, &st);
-    if (err && errno != ENOENT) {
-        return -errno;
-    }
-
-    if (!err && S_ISREG(st.st_mode)) {
-        int err = unlink(emu->path);
-        if (err) {
-            return -errno;
-        }
-    }
-
-    if (err || S_ISREG(st.st_mode)) {
-        FILE *f = fopen(emu->path, "w");
-        if (!f) {
-            return -errno;
-        }
-
-        err = fclose(f);
-        if (err) {
-            return -errno;
-        }
-    }
-
-    emu->stats.erase_count += 1;
-    return 0;
-}
-
-int lfs_emubd_sync(const struct lfs_config *cfg) {
-    lfs_emubd_t *emu = cfg->context;
-
-    // Just write out info/stats for later lookup
-    snprintf(emu->child, LFS_NAME_MAX, "config");
-    FILE *f = fopen(emu->path, "w");
-    if (!f) {
-        return -errno;
-    }
-
-    size_t res = fwrite(&emu->cfg, sizeof(emu->cfg), 1, f);
-    if (res < 1) {
-        return -errno;
-    }
-
-    int err = fclose(f);
-    if (err) {
-        return -errno;
-    }
-
-    snprintf(emu->child, LFS_NAME_MAX, "stats");
-    f = fopen(emu->path, "w");
-    if (!f) {
-        return -errno;
-    }
-
-    res = fwrite(&emu->stats, sizeof(emu->stats), 1, f);
-    if (res < 1) {
-        return -errno;
-    }
-
-    err = fclose(f);
-    if (err) {
-        return -errno;
-    }
-
-    return 0;
-}
-

emubd/lfs_emubd.h

@@ -1,78 +0,0 @@
-/*
- * Block device emulated on standard files
- *
- * Copyright (c) 2017 Christopher Haster
- * Distributed under the Apache 2.0 license
- */
-#ifndef LFS_EMUBD_H
-#define LFS_EMUBD_H
-
-#include "lfs.h"
-#include "lfs_util.h"
-
-
-// Config options
-#ifndef LFS_EMUBD_READ_SIZE
-#define LFS_EMUBD_READ_SIZE 1
-#endif
-
-#ifndef LFS_EMUBD_PROG_SIZE
-#define LFS_EMUBD_PROG_SIZE 1
-#endif
-
-#ifndef LFS_EMUBD_ERASE_SIZE
-#define LFS_EMUBD_ERASE_SIZE 512
-#endif
-
-#ifndef LFS_EMUBD_TOTAL_SIZE
-#define LFS_EMUBD_TOTAL_SIZE 524288
-#endif
-
-
-// The emu bd state
-typedef struct lfs_emubd {
-    char *path;
-    char *child;
-
-    struct {
-        uint64_t read_count;
-        uint64_t prog_count;
-        uint64_t erase_count;
-    } stats;
-
-    struct {
-        uint32_t read_size;
-        uint32_t prog_size;
-        uint32_t block_size;
-        uint32_t block_count;
-    } cfg;
-} lfs_emubd_t;
-
-
-// Create a block device using path for the directory to store blocks
-int lfs_emubd_create(const struct lfs_config *cfg, const char *path);
-
-// Clean up memory associated with emu block device
-void lfs_emubd_destroy(const struct lfs_config *cfg);
-
-// Read a block
-int lfs_emubd_read(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, void *buffer, lfs_size_t size);
-
-// Program a block
-//
-// The block must have previously been erased.
-int lfs_emubd_prog(const struct lfs_config *cfg, lfs_block_t block,
-        lfs_off_t off, const void *buffer, lfs_size_t size);
-
-// Erase a block
-//
-// A block must be erased before being programmed. The
-// state of an erased block is undefined.
-int lfs_emubd_erase(const struct lfs_config *cfg, lfs_block_t block);
-
-// Sync the block device
-int lfs_emubd_sync(const struct lfs_config *cfg);
-
-
-#endif

lfs.h

@@ -1,437 +0,0 @@
-/*
- * The little filesystem
- *
- * Copyright (c) 2017 Christopher Haster
- * Distributed under the Apache 2.0 license
- */
-#ifndef LFS_H
-#define LFS_H
-
-#include <stdint.h>
-#include <stdbool.h>
-
-
-/// Definitions ///
-
-// Type definitions
-typedef uint32_t lfs_size_t;
-typedef uint32_t lfs_off_t;
-
-typedef int32_t  lfs_ssize_t;
-typedef int32_t  lfs_soff_t;
-
-typedef uint32_t lfs_block_t;
-
-// Max name size in bytes
-#ifndef LFS_NAME_MAX
-#define LFS_NAME_MAX 255
-#endif
-
-// Possible error codes, these are negative to allow
-// valid positive return values
-enum lfs_error {
-    LFS_ERR_OK      = 0,    // No error
-    LFS_ERR_IO      = -5,   // Error during device operation
-    LFS_ERR_CORRUPT = -52,  // Corrupted
-    LFS_ERR_NOENT   = -2,   // No directory entry
-    LFS_ERR_EXISTS  = -17,  // Entry already exists
-    LFS_ERR_NOTDIR  = -20,  // Entry is not a dir
-    LFS_ERR_ISDIR   = -21,  // Entry is a dir
-    LFS_ERR_INVAL   = -22,  // Invalid parameter
-    LFS_ERR_NOSPC   = -28,  // No space left on device
-    LFS_ERR_NOMEM   = -12,  // No more memory available
-};
-
-// File types
-enum lfs_type {
-    LFS_TYPE_REG        = 0x11,
-    LFS_TYPE_DIR        = 0x22,
-    LFS_TYPE_SUPERBLOCK = 0xe2,
-};
-
-// File open flags
-enum lfs_open_flags {
-    // open flags
-    LFS_O_RDONLY = 1,        // Open a file as read only
-    LFS_O_WRONLY = 2,        // Open a file as write only
-    LFS_O_RDWR   = 3,        // Open a file as read and write
-    LFS_O_CREAT  = 0x0100,   // Create a file if it does not exist
-    LFS_O_EXCL   = 0x0200,   // Fail if a file already exists
-    LFS_O_TRUNC  = 0x0400,   // Truncate the existing file to zero size
-    LFS_O_APPEND = 0x0800,   // Move to end of file on every write
-
-    // internally used flags
-    LFS_F_DIRTY   = 0x10000, // File does not match storage
-    LFS_F_WRITING = 0x20000, // File has been written since last flush
-    LFS_F_READING = 0x40000, // File has been read since last flush
-};
-
-// File seek flags
-enum lfs_whence_flags {
-    LFS_SEEK_SET = 0,   // Seek relative to an absolute position
-    LFS_SEEK_CUR = 1,   // Seek relative to the current file position
-    LFS_SEEK_END = 2,   // Seek relative to the end of the file
-};
-
-
-// Configuration provided during initialization of the littlefs
-struct lfs_config {
-    // Opaque user provided context that can be used to pass
-    // information to the block device operations
-    void *context;
-
-    // Read a region in a block. Negative error codes are propogated
-    // to the user.
-    int (*read)(const struct lfs_config *c, lfs_block_t block,
-            lfs_off_t off, void *buffer, lfs_size_t size);
-
-    // Program a region in a block. The block must have previously
-    // been erased. Negative error codes are propogated to the user.
-    // The prog function must return LFS_ERR_CORRUPT if the block should
-    // be considered bad.
-    int (*prog)(const struct lfs_config *c, lfs_block_t block,
-            lfs_off_t off, const void *buffer, lfs_size_t size);
-
-    // Erase a block. A block must be erased before being programmed.
-    // The state of an erased block is undefined. Negative error codes
-    // are propogated to the user.
-    int (*erase)(const struct lfs_config *c, lfs_block_t block);
-
-    // Sync the state of the underlying block device. Negative error codes
-    // are propogated to the user.
-    int (*sync)(const struct lfs_config *c);
-
-    // Minimum size of a block read. This determines the size of read buffers.
-    // This may be larger than the physical read size to improve performance
-    // by caching more of the block device.
-    lfs_size_t read_size;
-
-    // Minimum size of a block program. This determines the size of program
-    // buffers. This may be larger than the physical program size to improve
-    // performance by caching more of the block device.
-    lfs_size_t prog_size;
-
-    // Size of an erasable block. This does not impact ram consumption and
-    // may be larger than the physical erase size. However, this should be
-    // kept small as each file currently takes up an entire block .
-    lfs_size_t block_size;
-
-    // Number of erasable blocks on the device.
-    lfs_size_t block_count;
-
-    // Number of blocks to lookahead during block allocation. A larger
-    // lookahead reduces the number of passes required to allocate a block.
-    // The lookahead buffer requires only 1 bit per block so it can be quite
-    // large with little ram impact. Should be a multiple of 32.
-    lfs_size_t lookahead;
-
-    // Optional, statically allocated read buffer. Must be read sized.
-    void *read_buffer;
-
-    // Optional, statically allocated program buffer. Must be program sized.
-    void *prog_buffer;
-
-    // Optional, statically allocated lookahead buffer. Must be 1 bit per
-    // lookahead block.
-    void *lookahead_buffer;
-
-    // Optional, statically allocated buffer for files. Must be program sized.
-    // If enabled, only one file may be opened at a time.
-    void *file_buffer;
-};
-
-
-// File info structure
-struct lfs_info {
-    // Type of the file, either LFS_TYPE_REG or LFS_TYPE_DIR
-    uint8_t type;
-
-    // Size of the file, only valid for REG files
-    lfs_size_t size;
-
-    // Name of the file stored as a null-terminated string
-    char name[LFS_NAME_MAX+1];
-};
-
-
-/// littlefs data structures ///
-typedef struct lfs_entry {
-    lfs_off_t off;
-
-    struct lfs_disk_entry {
-        uint8_t type;
-        uint8_t elen;
-        uint8_t alen;
-        uint8_t nlen;
-        union {
-            struct {
-                lfs_block_t head;
-                lfs_size_t size;
-            } file;
-            lfs_block_t dir[2];
-        } u;
-    } d;
-} lfs_entry_t;
-
-typedef struct lfs_cache {
-    lfs_block_t block;
-    lfs_off_t off;
-    uint8_t *buffer;
-} lfs_cache_t;
-
-typedef struct lfs_file {
-    struct lfs_file *next;
-    lfs_block_t pair[2];
-    lfs_off_t poff;
-
-    lfs_block_t head;
-    lfs_size_t size;
-
-    uint32_t flags;
-    lfs_off_t pos;
-    lfs_block_t block;
-    lfs_off_t off;
-    lfs_cache_t cache;
-} lfs_file_t;
-
-typedef struct lfs_dir {
-    lfs_block_t pair[2];
-    lfs_off_t off;
-
-    lfs_block_t head[2];
-    lfs_off_t pos;
-
-    struct lfs_disk_dir {
-        uint32_t rev;
-        lfs_size_t size;
-        lfs_block_t tail[2];
-    } d;
-} lfs_dir_t;
-
-typedef struct lfs_superblock {
-    lfs_off_t off;
-
-    struct lfs_disk_superblock {
-        uint8_t type;
-        uint8_t elen;
-        uint8_t alen;
-        uint8_t nlen;
-        lfs_block_t root[2];
-        uint32_t block_size;
-        uint32_t block_count;
-        uint32_t version;
-        char magic[8];
-    } d;
-} lfs_superblock_t;
-
-typedef struct lfs_free {
-    lfs_block_t end;
-    lfs_block_t start;
-    lfs_block_t off;
-    uint32_t *lookahead;
-} lfs_free_t;
-
-// The littlefs type
-typedef struct lfs {
-    const struct lfs_config *cfg;
-
-    lfs_block_t root[2];
-    lfs_file_t *files;
-    bool deorphaned;
-
-    lfs_cache_t rcache;
-    lfs_cache_t pcache;
-
-    lfs_free_t free;
-} lfs_t;
-
-
-/// Filesystem functions ///
-
-// Format a block device with the littlefs
-//
-// Requires a littlefs object and config struct. This clobbers the littlefs
-// object, and does not leave the filesystem mounted.
-//
-// Returns a negative error code on failure.
-int lfs_format(lfs_t *lfs, const struct lfs_config *config);
-
-// Mounts a littlefs
-//
-// Requires a littlefs object and config struct. Multiple filesystems
-// may be mounted simultaneously with multiple littlefs objects. Both
-// lfs and config must be allocated while mounted.
-//
-// Returns a negative error code on failure.
-int lfs_mount(lfs_t *lfs, const struct lfs_config *config);
-
-// Unmounts a littlefs
-//
-// Does nothing besides releasing any allocated resources.
-// Returns a negative error code on failure.
-int lfs_unmount(lfs_t *lfs);
-
-/// General operations ///
-
-// Removes a file or directory
-//
-// If removing a directory, the directory must be empty.
-// Returns a negative error code on failure.
-int lfs_remove(lfs_t *lfs, const char *path);
-
-// Rename or move a file or directory
-//
-// If the destination exists, it must match the source in type.
-// If the destination is a directory, the directory must be empty.
-//
-// Note: If power loss occurs, it is possible that the file or directory
-// will exist in both the oldpath and newpath simultaneously after the
-// next mount.
-//
-// Returns a negative error code on failure.
-int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath);
-
-// Find info about a file or directory
-//
-// Fills out the info structure, based on the specified file or directory.
-// Returns a negative error code on failure.
-int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
-
-
-/// File operations ///
-
-// Open a file
-//
-// The mode that the file is opened in is determined
-// by the flags, which are values from the enum lfs_open_flags
-// that are bitwise-ored together.
-//
-// Returns a negative error code on failure.
-int lfs_file_open(lfs_t *lfs, lfs_file_t *file,
-        const char *path, int flags);
-
-// Close a file
-//
-// Any pending writes are written out to storage as though
-// sync had been called and releases any allocated resources.
-//
-// Returns a negative error code on failure.
-int lfs_file_close(lfs_t *lfs, lfs_file_t *file);
-
-// Synchronize a file on storage
-//
-// Any pending writes are written out to storage.
-// Returns a negative error code on failure.
-int lfs_file_sync(lfs_t *lfs, lfs_file_t *file);
-
-// Read data from file
-//
-// Takes a buffer and size indicating where to store the read data.
-// Returns the number of bytes read, or a negative error code on failure.
-lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
-        void *buffer, lfs_size_t size);
-
-// Write data to file
-//
-// Takes a buffer and size indicating the data to write. The file will not
-// actually be updated on the storage until either sync or close is called.
-//
-// Returns the number of bytes written, or a negative error code on failure.
-lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
-        const void *buffer, lfs_size_t size);
-
-// Change the position of the file
-//
-// The change in position is determined by the offset and whence flag.
-// Returns the old position of the file, or a negative error code on failure.
-lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
-        lfs_soff_t off, int whence);
-
-// Return the position of the file
-//
-// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_CUR)
-// Returns the position of the file, or a negative error code on failure.
-lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file);
-
-// Change the position of the file to the beginning of the file
-//
-// Equivalent to lfs_file_seek(lfs, file, 0, LFS_SEEK_CUR)
-// Returns a negative error code on failure.
-int lfs_file_rewind(lfs_t *lfs, lfs_file_t *file);
-
-// Return the size of the file
-//
-// Similar to lfs_file_seek(lfs, file, 0, LFS_SEEK_END)
-// Returns the size of the file, or a negative error code on failure.
-lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file);
-
-
-/// Directory operations ///
-
-// Create a directory
-//
-// Returns a negative error code on failure.
-int lfs_mkdir(lfs_t *lfs, const char *path);
-
-// Open a directory
-//
-// Once open a directory can be used with read to iterate over files.
-// Returns a negative error code on failure.
-int lfs_dir_open(lfs_t *lfs, lfs_dir_t *dir, const char *path);
-
-// Close a directory
-//
-// Releases any allocated resources.
-// Returns a negative error code on failure.
-int lfs_dir_close(lfs_t *lfs, lfs_dir_t *dir);
-
-// Read an entry in the directory
-//
-// Fills out the info structure, based on the specified file or directory.
-// Returns a negative error code on failure.
-int lfs_dir_read(lfs_t *lfs, lfs_dir_t *dir, struct lfs_info *info);
-
-// Change the position of the directory
-//
-// The new off must be a value previous returned from tell and specifies
-// an absolute offset in the directory seek.
-//
-// Returns a negative error code on failure.
-int lfs_dir_seek(lfs_t *lfs, lfs_dir_t *dir, lfs_off_t off);
-
-// Return the position of the directory
-//
-// The returned offset is only meant to be consumed by seek and may not make
-// sense, but does indicate the current position in the directory iteration.
-//
-// Returns the position of the directory, or a negative error code on failure.
-lfs_soff_t lfs_dir_tell(lfs_t *lfs, lfs_dir_t *dir);
-
-// Change the position of the directory to the beginning of the directory
-//
-// Returns a negative error code on failure.
-int lfs_dir_rewind(lfs_t *lfs, lfs_dir_t *dir);
-
-
-/// Miscellaneous littlefs specific operations ///
-
-// Traverse through all blocks in use by the filesystem
-//
-// The provided callback will be called with each block address that is
-// currently in use by the filesystem. This can be used to determine which
-// blocks are in use or how much of the storage is available.
-//
-// Returns a negative error code on failure.
-int lfs_traverse(lfs_t *lfs, int (*cb)(void*, lfs_block_t), void *data);
-
-// Prunes any recoverable errors that may have occured in the filesystem
-//
-// Not needed to be called by user unless an operation is interrupted
-// but the filesystem is still mounted. This is already called on first
-// allocation.
-//
-// Returns a negative error code on failure.
-int lfs_deorphan(lfs_t *lfs);
-
-
-#endif

lfs2.h

@@ -0,0 +1,625 @@
+/*
+ * The little filesystem
+ *
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef LFS2_H
+#define LFS2_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
+/// Version info ///
+
+// Software library version
+// Major (top-nibble), incremented on backwards incompatible changes
+// Minor (bottom-nibble), incremented on feature additions
+#define LFS2_VERSION 0x00020000
+#define LFS2_VERSION_MAJOR (0xffff & (LFS2_VERSION >> 16))
+#define LFS2_VERSION_MINOR (0xffff & (LFS2_VERSION >>  0))
+
+// Version of On-disk data structures
+// Major (top-nibble), incremented on backwards incompatible changes
+// Minor (bottom-nibble), incremented on feature additions
+#define LFS2_DISK_VERSION 0x00020000
+#define LFS2_DISK_VERSION_MAJOR (0xffff & (LFS2_DISK_VERSION >> 16))
+#define LFS2_DISK_VERSION_MINOR (0xffff & (LFS2_DISK_VERSION >>  0))
+
+
+/// Definitions ///
+
+// Type definitions
+typedef uint32_t lfs2_size_t;
+typedef uint32_t lfs2_off_t;
+
+typedef int32_t  lfs2_ssize_t;
+typedef int32_t  lfs2_soff_t;
+
+typedef uint32_t lfs2_block_t;
+
+// Maximum name size in bytes, may be redefined to reduce the size of the
+// info struct. Limited to <= 1022. Stored in superblock and must be
+// respected by other littlefs drivers.
+#ifndef LFS2_NAME_MAX
+#define LFS2_NAME_MAX 255
+#endif
+
+// Maximum size of a file in bytes, may be redefined to limit to support other
+// drivers. Limited on disk to <= 4294967296. However, above 2147483647 the
+// functions lfs2_file_seek, lfs2_file_size, and lfs2_file_tell will return
+// incorrect values due to using signed integers. Stored in superblock and
+// must be respected by other littlefs drivers.
+#ifndef LFS2_FILE_MAX
+#define LFS2_FILE_MAX 2147483647
+#endif
+
+// Maximum size of custom attributes in bytes, may be redefined, but there is
+// no real benefit to using a smaller LFS2_ATTR_MAX. Limited to <= 1022.
+#ifndef LFS2_ATTR_MAX
+#define LFS2_ATTR_MAX 1022
+#endif
+
+// Possible error codes, these are negative to allow
+// valid positive return values
+enum lfs2_error {
+    LFS2_ERR_OK          = 0,    // No error
+    LFS2_ERR_IO          = -5,   // Error during device operation
+    LFS2_ERR_CORRUPT     = -84,  // Corrupted
+    LFS2_ERR_NOENT       = -2,   // No directory entry
+    LFS2_ERR_EXIST       = -17,  // Entry already exists
+    LFS2_ERR_NOTDIR      = -20,  // Entry is not a dir
+    LFS2_ERR_ISDIR       = -21,  // Entry is a dir
+    LFS2_ERR_NOTEMPTY    = -39,  // Dir is not empty
+    LFS2_ERR_BADF        = -9,   // Bad file number
+    LFS2_ERR_FBIG        = -27,  // File too large
+    LFS2_ERR_INVAL       = -22,  // Invalid parameter
+    LFS2_ERR_NOSPC       = -28,  // No space left on device
+    LFS2_ERR_NOMEM       = -12,  // No more memory available
+    LFS2_ERR_NOATTR      = -61,  // No data/attr available
+    LFS2_ERR_NAMETOOLONG = -36,  // File name too long
+};
+
+// File types
+enum lfs2_type {
+    // file types
+    LFS2_TYPE_REG            = 0x001,
+    LFS2_TYPE_DIR            = 0x002,
+
+    // internally used types
+    LFS2_TYPE_SPLICE         = 0x400,
+    LFS2_TYPE_NAME           = 0x000,
+    LFS2_TYPE_STRUCT         = 0x200,
+    LFS2_TYPE_USERATTR       = 0x300,
+    LFS2_TYPE_FROM           = 0x100,
+    LFS2_TYPE_TAIL           = 0x600,
+    LFS2_TYPE_GLOBALS        = 0x700,
+    LFS2_TYPE_CRC            = 0x500,
+
+    // internally used type specializations
+    LFS2_TYPE_CREATE         = 0x401,
+    LFS2_TYPE_DELETE         = 0x4ff,
+    LFS2_TYPE_SUPERBLOCK     = 0x0ff,
+    LFS2_TYPE_DIRSTRUCT      = 0x200,
+    LFS2_TYPE_CTZSTRUCT      = 0x202,
+    LFS2_TYPE_INLINESTRUCT   = 0x201,
+    LFS2_TYPE_SOFTTAIL       = 0x600,
+    LFS2_TYPE_HARDTAIL       = 0x601,
+    LFS2_TYPE_MOVESTATE      = 0x7ff,
+
+    // internal chip sources
+    LFS2_FROM_NOOP           = 0x000,
+    LFS2_FROM_MOVE           = 0x101,
+    LFS2_FROM_USERATTRS      = 0x102,
+};
+
+// File open flags
+enum lfs2_open_flags {
+    // open flags
+    LFS2_O_RDONLY = 1,         // Open a file as read only
+    LFS2_O_WRONLY = 2,         // Open a file as write only
+    LFS2_O_RDWR   = 3,         // Open a file as read and write
+    LFS2_O_CREAT  = 0x0100,    // Create a file if it does not exist
+    LFS2_O_EXCL   = 0x0200,    // Fail if a file already exists
+    LFS2_O_TRUNC  = 0x0400,    // Truncate the existing file to zero size
+    LFS2_O_APPEND = 0x0800,    // Move to end of file on every write
+
+    // internally used flags
+    LFS2_F_DIRTY   = 0x010000, // File does not match storage
+    LFS2_F_WRITING = 0x020000, // File has been written since last flush
+    LFS2_F_READING = 0x040000, // File has been read since last flush
+    LFS2_F_ERRED   = 0x080000, // An error occured during write
+    LFS2_F_INLINE  = 0x100000, // Currently inlined in directory entry
+};
+
+// File seek flags
+enum lfs2_whence_flags {
+    LFS2_SEEK_SET = 0,   // Seek relative to an absolute position
+    LFS2_SEEK_CUR = 1,   // Seek relative to the current file position
+    LFS2_SEEK_END = 2,   // Seek relative to the end of the file
+};
+
+
+// Configuration provided during initialization of the littlefs
+struct lfs2_config {
+    // Opaque user provided context that can be used to pass
+    // information to the block device operations
+    void *context;
+
+    // Read a region in a block. Negative error codes are propogated
+    // to the user.
+    int (*read)(const struct lfs2_config *c, lfs2_block_t block,
+            lfs2_off_t off, void *buffer, lfs2_size_t size);
+
+    // Program a region in a block. The block must have previously
+    // been erased. Negative error codes are propogated to the user.
+    // May return LFS2_ERR_CORRUPT if the block should be considered bad.
+    int (*prog)(const struct lfs2_config *c, lfs2_block_t block,
+            lfs2_off_t off, const void *buffer, lfs2_size_t size);
+
+    // Erase a block. A block must be erased before being programmed.
+    // The state of an erased block is undefined. Negative error codes
+    // are propogated to the user.
+    // May return LFS2_ERR_CORRUPT if the block should be considered bad.
+    int (*erase)(const struct lfs2_config *c, lfs2_block_t block);
+
+    // Sync the state of the underlying block device. Negative error codes
+    // are propogated to the user.
+    int (*sync)(const struct lfs2_config *c);
+
+    // Minimum size of a block read. All read operations will be a
+    // multiple of this value.
+    lfs2_size_t read_size;
+
+    // Minimum size of a block program. All program operations will be a
+    // multiple of this value.
+    lfs2_size_t prog_size;
+
+    // Size of an erasable block. This does not impact ram consumption and
+    // may be larger than the physical erase size. However, non-inlined files
+    // take up at minimum one block. Must be a multiple of the read
+    // and program sizes.
+    lfs2_size_t block_size;
+
+    // Number of erasable blocks on the device.
+    lfs2_size_t block_count;
+
+    // Number of erase cycles before we should move data to another block.
+    // May be zero, in which case no block-level wear-leveling is performed.
+    uint32_t block_cycles;
+
+    // Size of block caches. Each cache buffers a portion of a block in RAM.
+    // The littlefs needs a read cache, a program cache, and one additional
+    // cache per file. Larger caches can improve performance by storing more
+    // data and reducing the number of disk accesses. Must be a multiple of
+    // the read and program sizes, and a factor of the block size.
+    lfs2_size_t cache_size;
+
+    // Size of the lookahead buffer in bytes. A larger lookahead buffer
+    // increases the number of blocks found during an allocation pass. The
+    // lookahead buffer is stored as a compact bitmap, so each byte of RAM
+    // can track 8 blocks. Must be a multiple of 4.
+    lfs2_size_t lookahead_size;
+
+    // Optional statically allocated read buffer. Must be cache_size.
+    // By default lfs2_malloc is used to allocate this buffer.
+    void *read_buffer;
+
+    // Optional statically allocated program buffer. Must be cache_size.
+    // By default lfs2_malloc is used to allocate this buffer.
+    void *prog_buffer;
+
+    // Optional statically allocated program buffer. Must be lookahead_size.
+    // By default lfs2_malloc is used to allocate this buffer.
+    void *lookahead_buffer;
+
+    // Optional upper limit on length of file names in bytes. No downside for
+    // larger names except the size of the info struct which is controlled by
+    // the LFS2_NAME_MAX define. Defaults to LFS2_NAME_MAX when zero. Stored in
+    // superblock and must be respected by other littlefs drivers.
+    lfs2_size_t name_max;
+
+    // Optional upper limit on files in bytes. No downside for larger files
+    // but must be <= LFS2_FILE_MAX. Defaults to LFS2_FILE_MAX when zero. Stored
+    // in superblock and must be respected by other littlefs drivers.
+    lfs2_size_t file_max;
+
+    // Optional upper limit on custom attributes in bytes. No downside for
+    // larger attributes size but must be <= LFS2_ATTR_MAX. Defaults to
+    // LFS2_ATTR_MAX when zero.
+    lfs2_size_t attr_max;
+};
+
+// File info structure
+struct lfs2_info {
+    // Type of the file, either LFS2_TYPE_REG or LFS2_TYPE_DIR
+    uint8_t type;
+
+    // Size of the file, only valid for REG files. Limited to 32-bits.
+    lfs2_size_t size;
+
+    // Name of the file stored as a null-terminated string. Limited to
+    // LFS2_NAME_MAX+1, which can be changed by redefining LFS2_NAME_MAX to
+    // reduce RAM. LFS2_NAME_MAX is stored in superblock and must be
+    // respected by other littlefs drivers.
+    char name[LFS2_NAME_MAX+1];
+};
+
+// Custom attribute structure, used to describe custom attributes
+// committed atomically during file writes.
+struct lfs2_attr {
+    // 8-bit type of attribute, provided by user and used to
+    // identify the attribute
+    uint8_t type;
+
+    // Pointer to buffer containing the attribute
+    void *buffer;
+
+    // Size of attribute in bytes, limited to LFS2_ATTR_MAX
+    lfs2_size_t size;
+};
+
+// Optional configuration provided during lfs2_file_opencfg
+struct lfs2_file_config {
+    // Optional statically allocated file buffer. Must be cache_size.
+    // By default lfs2_malloc is used to allocate this buffer.
+    void *buffer;
+
+    // Optional list of custom attributes related to the file. If the file
+    // is opened with read access, these attributes will be read from disk
+    // during the open call. If the file is opened with write access, the
+    // attributes will be written to disk every file sync or close. This
+    // write occurs atomically with update to the file's contents.
+    //
+    // Custom attributes are uniquely identified by an 8-bit type and limited
+    // to LFS2_ATTR_MAX bytes. When read, if the stored attribute is smaller
+    // than the buffer, it will be padded with zeros. If the stored attribute
+    // is larger, then it will be silently truncated. If the attribute is not
+    // found, it will be created implicitly.
+    struct lfs2_attr *attrs;
+
+    // Number of custom attributes in the list
+    lfs2_size_t attr_count;
+};
+
+
+/// internal littlefs data structures ///
+typedef struct lfs2_cache {
+    lfs2_block_t block;
+    lfs2_off_t off;
+    lfs2_size_t size;
+    uint8_t *buffer;
+} lfs2_cache_t;
+
+typedef struct lfs2_mdir {
+    lfs2_block_t pair[2];
+    uint32_t rev;
+    lfs2_off_t off;
+    uint32_t etag;
+    uint16_t count;
+    bool erased;
+    bool split;
+    lfs2_block_t tail[2];
+} lfs2_mdir_t;
+
+// littlefs directory type
+typedef struct lfs2_dir {
+    struct lfs2_dir *next;
+    uint16_t id;
+    uint8_t type;
+    lfs2_mdir_t m;
+
+    lfs2_off_t pos;
+    lfs2_block_t head[2];
+} lfs2_dir_t;
+
+// littlefs file type
+typedef struct lfs2_file {
+    struct lfs2_file *next;
+    uint16_t id;
+    uint8_t type;
+    lfs2_mdir_t m;
+
+    struct lfs2_ctz {
+        lfs2_block_t head;
+        lfs2_size_t size;
+    } ctz;
+
+    uint32_t flags;
+    lfs2_off_t pos;
+    lfs2_block_t block;
+    lfs2_off_t off;
+    lfs2_cache_t cache;
+
+    const struct lfs2_file_config *cfg;
+} lfs2_file_t;
+
+typedef struct lfs2_superblock {
+    uint32_t version;
+    lfs2_size_t block_size;
+    lfs2_size_t block_count;
+    lfs2_size_t name_max;
+    lfs2_size_t file_max;
+    lfs2_size_t attr_max;
+} lfs2_superblock_t;
+
+// The littlefs filesystem type
+typedef struct lfs2 {
+    lfs2_cache_t rcache;
+    lfs2_cache_t pcache;
+
+    lfs2_block_t root[2];
+    struct lfs2_mlist {
+        struct lfs2_mlist *next;
+        uint16_t id;
+        uint8_t type;
+        lfs2_mdir_t m;
+    } *mlist;
+    uint32_t seed;
+
+    struct lfs2_gstate {
+        uint32_t tag;
+        lfs2_block_t pair[2];
+    } gstate, gpending, gdelta;
+
+    struct lfs2_free {
+        lfs2_block_t off;
+        lfs2_block_t size;
+        lfs2_block_t i;
+        lfs2_block_t ack;
+        uint32_t *buffer;
+    } free;
+
+    const struct lfs2_config *cfg;
+    lfs2_size_t name_max;
+    lfs2_size_t file_max;
+    lfs2_size_t attr_max;
+} lfs2_t;
+
+
+/// Filesystem functions ///
+
+// Format a block device with the littlefs
+//
+// Requires a littlefs object and config struct. This clobbers the littlefs
+// object, and does not leave the filesystem mounted. The config struct must
+// be zeroed for defaults and backwards compatibility.
+//
+// Returns a negative error code on failure.
+int lfs2_format(lfs2_t *lfs2, const struct lfs2_config *config);
+
+// Mounts a littlefs
+//
+// Requires a littlefs object and config struct. Multiple filesystems
+// may be mounted simultaneously with multiple littlefs objects. Both
+// lfs2 and config must be allocated while mounted. The config struct must
+// be zeroed for defaults and backwards compatibility.
+//
+// Returns a negative error code on failure.
+int lfs2_mount(lfs2_t *lfs2, const struct lfs2_config *config);
+
+// Unmounts a littlefs
+//
+// Does nothing besides releasing any allocated resources.
+// Returns a negative error code on failure.
+int lfs2_unmount(lfs2_t *lfs2);
+
+/// General operations ///
+
+// Removes a file or directory
+//
+// If removing a directory, the directory must be empty.
+// Returns a negative error code on failure.
+int lfs2_remove(lfs2_t *lfs2, const char *path);
+
+// Rename or move a file or directory
+//
+// If the destination exists, it must match the source in type.
+// If the destination is a directory, the directory must be empty.
+//
+// Returns a negative error code on failure.
+int lfs2_rename(lfs2_t *lfs2, const char *oldpath, const char *newpath);
+
+// Find info about a file or directory
+//
+// Fills out the info structure, based on the specified file or directory.
+// Returns a negative error code on failure.
+int lfs2_stat(lfs2_t *lfs2, const char *path, struct lfs2_info *info);
+
+// Get a custom attribute
+//
+// Custom attributes are uniquely identified by an 8-bit type and limited
+// to LFS2_ATTR_MAX bytes. When read, if the stored attribute is smaller than
+// the buffer, it will be padded with zeros. If the stored attribute is larger,
+// then it will be silently truncated. If no attribute is found, the error
+// LFS2_ERR_NOATTR is returned and the buffer is filled with zeros.
+//
+// Returns the size of the attribute, or a negative error code on failure.
+// Note, the returned size is the size of the attribute on disk, irrespective
+// of the size of the buffer. This can be used to dynamically allocate a buffer
+// or check for existance.
+lfs2_ssize_t lfs2_getattr(lfs2_t *lfs2, const char *path,
+        uint8_t type, void *buffer, lfs2_size_t size);
+
+// Set custom attributes
+//
+// Custom attributes are uniquely identified by an 8-bit type and limited
+// to LFS2_ATTR_MAX bytes. If an attribute is not found, it will be
+// implicitly created.
+//
+// Returns a negative error code on failure.
+int lfs2_setattr(lfs2_t *lfs2, const char *path,
+        uint8_t type, const void *buffer, lfs2_size_t size);
+
+// Removes a custom attribute
+//
+// If an attribute is not found, nothing happens.
+//
+// Returns a negative error code on failure.
+int lfs2_removeattr(lfs2_t *lfs2, const char *path, uint8_t type);
+
+
+/// File operations ///
+
+// Open a file
+//
+// The mode that the file is opened in is determined by the flags, which
+// are values from the enum lfs2_open_flags that are bitwise-ored together.
+//
+// Returns a negative error code on failure.
+int lfs2_file_open(lfs2_t *lfs2, lfs2_file_t *file,
+        const char *path, int flags);
+
+// Open a file with extra configuration
+//
+// The mode that the file is opened in is determined by the flags, which
+// are values from the enum lfs2_open_flags that are bitwise-ored together.
+//
+// The config struct provides additional config options per file as described
+// above. The config struct must be allocated while the file is open, and the
+// config struct must be zeroed for defaults and backwards compatibility.
+//
+// Returns a negative error code on failure.
+int lfs2_file_opencfg(lfs2_t *lfs2, lfs2_file_t *file,
+        const char *path, int flags,
+        const struct lfs2_file_config *config);
+
+// Close a file
+//
+// Any pending writes are written out to storage as though
+// sync had been called and releases any allocated resources.
+//
+// Returns a negative error code on failure.
+int lfs2_file_close(lfs2_t *lfs2, lfs2_file_t *file);
+
+// Synchronize a file on storage
+//
+// Any pending writes are written out to storage.
+// Returns a negative error code on failure.
+int lfs2_file_sync(lfs2_t *lfs2, lfs2_file_t *file);
+
+// Read data from file
+//
+// Takes a buffer and size indicating where to store the read data.
+// Returns the number of bytes read, or a negative error code on failure.
+lfs2_ssize_t lfs2_file_read(lfs2_t *lfs2, lfs2_file_t *file,
+        void *buffer, lfs2_size_t size);
+
+// Write data to file
+//
+// Takes a buffer and size indicating the data to write. The file will not
+// actually be updated on the storage until either sync or close is called.
+//
+// Returns the number of bytes written, or a negative error code on failure.
+lfs2_ssize_t lfs2_file_write(lfs2_t *lfs2, lfs2_file_t *file,
+        const void *buffer, lfs2_size_t size);
+
+// Change the position of the file
+//
+// The change in position is determined by the offset and whence flag.
+// Returns the old position of the file, or a negative error code on failure.
+lfs2_soff_t lfs2_file_seek(lfs2_t *lfs2, lfs2_file_t *file,
+        lfs2_soff_t off, int whence);
+
+// Truncates the size of the file to the specified size
+//
+// Returns a negative error code on failure.
+int lfs2_file_truncate(lfs2_t *lfs2, lfs2_file_t *file, lfs2_off_t size);
+
+// Return the position of the file
+//
+// Equivalent to lfs2_file_seek(lfs2, file, 0, LFS2_SEEK_CUR)
+// Returns the position of the file, or a negative error code on failure.
+lfs2_soff_t lfs2_file_tell(lfs2_t *lfs2, lfs2_file_t *file);
+
+// Change the position of the file to the beginning of the file
+//
+// Equivalent to lfs2_file_seek(lfs2, file, 0, LFS2_SEEK_CUR)
+// Returns a negative error code on failure.
+int lfs2_file_rewind(lfs2_t *lfs2, lfs2_file_t *file);
+
+// Return the size of the file
+//
+// Similar to lfs2_file_seek(lfs2, file, 0, LFS2_SEEK_END)
+// Returns the size of the file, or a negative error code on failure.
+lfs2_soff_t lfs2_file_size(lfs2_t *lfs2, lfs2_file_t *file);
+
+
+/// Directory operations ///
+
+// Create a directory
+//
+// Returns a negative error code on failure.
+int lfs2_mkdir(lfs2_t *lfs2, const char *path);
+
+// Open a directory
+//
+// Once open a directory can be used with read to iterate over files.
+// Returns a negative error code on failure.
+int lfs2_dir_open(lfs2_t *lfs2, lfs2_dir_t *dir, const char *path);
+
+// Close a directory
+//
+// Releases any allocated resources.
+// Returns a negative error code on failure.
+int lfs2_dir_close(lfs2_t *lfs2, lfs2_dir_t *dir);
+
+// Read an entry in the directory
+//
+// Fills out the info structure, based on the specified file or directory.
+// Returns a negative error code on failure.
+int lfs2_dir_read(lfs2_t *lfs2, lfs2_dir_t *dir, struct lfs2_info *info);
+
+// Change the position of the directory
+//
+// The new off must be a value previous returned from tell and specifies
+// an absolute offset in the directory seek.
+//
+// Returns a negative error code on failure.
+int lfs2_dir_seek(lfs2_t *lfs2, lfs2_dir_t *dir, lfs2_off_t off);
+
+// Return the position of the directory
+//
+// The returned offset is only meant to be consumed by seek and may not make
+// sense, but does indicate the current position in the directory iteration.
+//
+// Returns the position of the directory, or a negative error code on failure.
+lfs2_soff_t lfs2_dir_tell(lfs2_t *lfs2, lfs2_dir_t *dir);
+
+// Change the position of the directory to the beginning of the directory
+//
+// Returns a negative error code on failure.
+int lfs2_dir_rewind(lfs2_t *lfs2, lfs2_dir_t *dir);
+
+
+/// Filesystem-level filesystem operations
+
+// Finds the current size of the filesystem
+//
+// Note: Result is best effort. If files share COW structures, the returned
+// size may be larger than the filesystem actually is.
+//
+// Returns the number of allocated blocks, or a negative error code on failure.
+lfs2_ssize_t lfs2_fs_size(lfs2_t *lfs2);
+
+// Traverse through all blocks in use by the filesystem
+//
+// The provided callback will be called with each block address that is
+// currently in use by the filesystem. This can be used to determine which
+// blocks are in use or how much of the storage is available.
+//
+// Returns a negative error code on failure.
+int lfs2_fs_traverse(lfs2_t *lfs2, int (*cb)(void*, lfs2_block_t), void *data);
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

lfs2_util.c

@@ -0,0 +1,33 @@
+/*
+ * lfs2 util functions
+ *
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include "lfs2_util.h"
+
+// Only compile if user does not provide custom config
+#ifndef LFS2_CONFIG
+
+
+// Software CRC implementation with small lookup table
+uint32_t lfs2_crc(uint32_t crc, const void *buffer, size_t size) {
+    static const uint32_t rtable[16] = {
+        0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
+        0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
+        0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
+        0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
+    };
+
+    const uint8_t *data = buffer;
+
+    for (size_t i = 0; i < size; i++) {
+        crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 0)) & 0xf];
+        crc = (crc >> 4) ^ rtable[(crc ^ (data[i] >> 4)) & 0xf];
+    }
+
+    return crc;
+}
+
+
+#endif

lfs2_util.h

@@ -0,0 +1,219 @@
+/*
+ * lfs2 utility functions
+ *
+ * Copyright (c) 2017, Arm Limited. All rights reserved.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#ifndef LFS2_UTIL_H
+#define LFS2_UTIL_H
+
+// Users can override lfs2_util.h with their own configuration by defining
+// LFS2_CONFIG as a header file to include (-DLFS2_CONFIG=lfs2_config.h).
+//
+// If LFS2_CONFIG is used, none of the default utils will be emitted and must be
+// provided by the config file. To start, I would suggest copying lfs2_util.h
+// and modifying as needed.
+#ifdef LFS2_CONFIG
+#define LFS2_STRINGIZE(x) LFS2_STRINGIZE2(x)
+#define LFS2_STRINGIZE2(x) #x
+#include LFS2_STRINGIZE(LFS2_CONFIG)
+#else
+
+// System includes
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <inttypes.h>
+
+#ifndef LFS2_NO_MALLOC
+#include <stdlib.h>
+#endif
+#ifndef LFS2_NO_ASSERT
+#include <assert.h>
+#endif
+#if !defined(LFS2_NO_DEBUG) || !defined(LFS2_NO_WARN) || !defined(LFS2_NO_ERROR)
+#include <stdio.h>
+#endif
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+
+// Macros, may be replaced by system specific wrappers. Arguments to these
+// macros must not have side-effects as the macros can be removed for a smaller
+// code footprint
+
+// Logging functions
+#ifndef LFS2_NO_DEBUG
+#define LFS2_DEBUG(fmt, ...) \
+    printf("lfs2 debug:%d: " fmt "\n", __LINE__, __VA_ARGS__)
+#else
+#define LFS2_DEBUG(fmt, ...)
+#endif
+
+#ifndef LFS2_NO_WARN
+#define LFS2_WARN(fmt, ...) \
+    printf("lfs2 warn:%d: " fmt "\n", __LINE__, __VA_ARGS__)
+#else
+#define LFS2_WARN(fmt, ...)
+#endif
+
+#ifndef LFS2_NO_ERROR
+#define LFS2_ERROR(fmt, ...) \
+    printf("lfs2 error:%d: " fmt "\n", __LINE__, __VA_ARGS__)
+#else
+#define LFS2_ERROR(fmt, ...)
+#endif
+
+// Runtime assertions
+#ifndef LFS2_NO_ASSERT
+#define LFS2_ASSERT(test) assert(test)
+#else
+#define LFS2_ASSERT(test)
+#endif
+
+
+// Builtin functions, these may be replaced by more efficient
+// toolchain-specific implementations. LFS2_NO_INTRINSICS falls back to a more
+// expensive basic C implementation for debugging purposes
+
+// Min/max functions for unsigned 32-bit numbers
+static inline uint32_t lfs2_max(uint32_t a, uint32_t b) {
+    return (a > b) ? a : b;
+}
+
+static inline uint32_t lfs2_min(uint32_t a, uint32_t b) {
+    return (a < b) ? a : b;
+}
+
+// Align to nearest multiple of a size
+static inline uint32_t lfs2_aligndown(uint32_t a, uint32_t alignment) {
+    return a - (a % alignment);
+}
+
+static inline uint32_t lfs2_alignup(uint32_t a, uint32_t alignment) {
+    return lfs2_aligndown(a + alignment-1, alignment);
+}
+
+// Find the next smallest power of 2 less than or equal to a
+static inline uint32_t lfs2_npw2(uint32_t a) {
+#if !defined(LFS2_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
+    return 32 - __builtin_clz(a-1);
+#else
+    uint32_t r = 0;
+    uint32_t s;
+    a -= 1;
+    s = (a > 0xffff) << 4; a >>= s; r |= s;
+    s = (a > 0xff  ) << 3; a >>= s; r |= s;
+    s = (a > 0xf   ) << 2; a >>= s; r |= s;
+    s = (a > 0x3   ) << 1; a >>= s; r |= s;
+    return (r | (a >> 1)) + 1;
+#endif
+}
+
+// Count the number of trailing binary zeros in a
+// lfs2_ctz(0) may be undefined
+static inline uint32_t lfs2_ctz(uint32_t a) {
+#if !defined(LFS2_NO_INTRINSICS) && defined(__GNUC__)
+    return __builtin_ctz(a);
+#else
+    return lfs2_npw2((a & -a) + 1) - 1;
+#endif
+}
+
+// Count the number of binary ones in a
+static inline uint32_t lfs2_popc(uint32_t a) {
+#if !defined(LFS2_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
+    return __builtin_popcount(a);
+#else
+    a = a - ((a >> 1) & 0x55555555);
+    a = (a & 0x33333333) + ((a >> 2) & 0x33333333);
+    return (((a + (a >> 4)) & 0xf0f0f0f) * 0x1010101) >> 24;
+#endif
+}
+
+// Find the sequence comparison of a and b, this is the distance
+// between a and b ignoring overflow
+static inline int lfs2_scmp(uint32_t a, uint32_t b) {
+    return (int)(unsigned)(a - b);
+}
+
+// Convert between 32-bit little-endian and native order
+static inline uint32_t lfs2_fromle32(uint32_t a) {
+#if !defined(LFS2_NO_INTRINSICS) && ( \
+    (defined(  BYTE_ORDER  ) &&   BYTE_ORDER   ==   ORDER_LITTLE_ENDIAN  ) || \
+    (defined(__BYTE_ORDER  ) && __BYTE_ORDER   == __ORDER_LITTLE_ENDIAN  ) || \
+    (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+    return a;
+#elif !defined(LFS2_NO_INTRINSICS) && ( \
+    (defined(  BYTE_ORDER  ) &&   BYTE_ORDER   ==   ORDER_BIG_ENDIAN  ) || \
+    (defined(__BYTE_ORDER  ) && __BYTE_ORDER   == __ORDER_BIG_ENDIAN  ) || \
+    (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+    return __builtin_bswap32(a);
+#else
+    return (((uint8_t*)&a)[0] <<  0) |
+           (((uint8_t*)&a)[1] <<  8) |
+           (((uint8_t*)&a)[2] << 16) |
+           (((uint8_t*)&a)[3] << 24);
+#endif
+}
+
+static inline uint32_t lfs2_tole32(uint32_t a) {
+    return lfs2_fromle32(a);
+}
+
+// Convert between 32-bit big-endian and native order
+static inline uint32_t lfs2_frombe32(uint32_t a) {
+#if !defined(LFS2_NO_INTRINSICS) && ( \
+    (defined(  BYTE_ORDER  ) &&   BYTE_ORDER   ==   ORDER_LITTLE_ENDIAN  ) || \
+    (defined(__BYTE_ORDER  ) && __BYTE_ORDER   == __ORDER_LITTLE_ENDIAN  ) || \
+    (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+    return __builtin_bswap32(a);
+#elif !defined(LFS2_NO_INTRINSICS) && ( \
+    (defined(  BYTE_ORDER  ) &&   BYTE_ORDER   ==   ORDER_BIG_ENDIAN  ) || \
+    (defined(__BYTE_ORDER  ) && __BYTE_ORDER   == __ORDER_BIG_ENDIAN  ) || \
+    (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+    return a;
+#else
+    return (((uint8_t*)&a)[0] << 24) |
+           (((uint8_t*)&a)[1] << 16) |
+           (((uint8_t*)&a)[2] <<  8) |
+           (((uint8_t*)&a)[3] <<  0);
+#endif
+}
+
+static inline uint32_t lfs2_tobe32(uint32_t a) {
+    return lfs2_frombe32(a);
+}
+
+// Calculate CRC-32 with polynomial = 0x04c11db7
+uint32_t lfs2_crc(uint32_t crc, const void *buffer, size_t size);
+
+// Allocate memory, only used if buffers are not provided to littlefs
+static inline void *lfs2_malloc(size_t size) {
+#ifndef LFS2_NO_MALLOC
+    return malloc(size);
+#else
+    (void)size;
+    return NULL;
+#endif
+}
+
+// Deallocate memory, only used if buffers are not provided to littlefs
+static inline void lfs2_free(void *p) {
+#ifndef LFS2_NO_MALLOC
+    free(p);
+#else
+    (void)p;
+#endif
+}
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif
+#endif

lfs_util.c

@@ -1,25 +0,0 @@
-/*
- * lfs util functions
- *
- * Copyright (c) 2017 Christopher Haster
- * Distributed under the Apache 2.0 license
- */
-#include "lfs_util.h"
-
-
-void lfs_crc(uint32_t *restrict crc, const void *buffer, size_t size) {
-    static const uint32_t rtable[16] = {
-        0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
-        0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
-        0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
-        0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c,
-    };
-
-    const uint8_t *data = buffer;
-
-    for (size_t i = 0; i < size; i++) {
-        *crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 0)) & 0xf];
-        *crc = (*crc >> 4) ^ rtable[(*crc ^ (data[i] >> 4)) & 0xf];
-    }
-}
-

lfs_util.h

@@ -1,45 +0,0 @@
-/*
- * lfs utility functions
- *
- * Copyright (c) 2017 Christopher Haster
- * Distributed under the Apache 2.0 license
- */
-#ifndef LFS_UTIL_H
-#define LFS_UTIL_H
-
-#include <stdlib.h>
-#include <stdint.h>
-#include <stdio.h>
-
-
-// Builtin functions
-static inline uint32_t lfs_max(uint32_t a, uint32_t b) {
-    return (a > b) ? a : b;
-}
-
-static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
-    return (a < b) ? a : b;
-}
-
-static inline uint32_t lfs_ctz(uint32_t a) {
-    return __builtin_ctz(a);
-}
-
-static inline uint32_t lfs_npw2(uint32_t a) {
-    return 32 - __builtin_clz(a-1);
-}
-
-static inline int lfs_scmp(uint32_t a, uint32_t b) {
-    return (int)(unsigned)(a - b);
-}
-
-void lfs_crc(uint32_t *crc, const void *buffer, size_t size);
-
-
-// Logging functions
-#define LFS_DEBUG(fmt, ...) printf("lfs debug: " fmt "\n", __VA_ARGS__)
-#define LFS_WARN(fmt, ...)  printf("lfs warn: " fmt "\n", __VA_ARGS__)
-#define LFS_ERROR(fmt, ...) printf("lfs error: " fmt "\n", __VA_ARGS__)
-
-
-#endif

scripts/prefix.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python
+
+# This script replaces prefixes of files, and symbols in that file.
+# Useful for creating different versions of the codebase that don't
+# conflict at compile time.
+#
+# example:
+# $ ./scripts/prefix.py lfs22
+
+import os
+import os.path
+import re
+import glob
+import itertools
+import tempfile
+import shutil
+import subprocess
+
+DEFAULT_PREFIX = "lfs2"
+
+def subn(from_prefix, to_prefix, name):
+    name, count1 = re.subn('\\b'+from_prefix, to_prefix, name)
+    name, count2 = re.subn('\\b'+from_prefix.upper(), to_prefix.upper(), name)
+    name, count3 = re.subn('\\B-D'+from_prefix.upper(),
+            '-D'+to_prefix.upper(), name)
+    return name, count1+count2+count3
+
+def main(from_prefix, to_prefix=None, files=None):
+    if not to_prefix:
+        from_prefix, to_prefix = DEFAULT_PREFIX, from_prefix
+
+    if not files:
+        files = subprocess.check_output([
+                'git', 'ls-tree', '-r', '--name-only', 'HEAD']).split()
+
+    for oldname in files:
+        # Rename any matching file names
+        newname, namecount = subn(from_prefix, to_prefix, oldname)
+        if namecount:
+            subprocess.check_call(['git', 'mv', oldname, newname])
+
+        # Rename any prefixes in file
+        count = 0
+        with open(newname+'~', 'w') as tempf:
+            with open(newname) as newf:
+                for line in newf:
+                    line, n = subn(from_prefix, to_prefix, line)
+                    count += n
+                    tempf.write(line)
+        shutil.copystat(newname, newname+'~')
+        os.rename(newname+'~', newname)
+        subprocess.check_call(['git', 'add', newname])
+
+        # Summary
+        print '%s: %d replacements' % (
+                '%s -> %s' % (oldname, newname) if namecount else oldname,
+                count)
+
+if __name__ == "__main__":
+    import sys
+    sys.exit(main(*sys.argv[1:]))

tests/corrupt.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+import struct
+import sys
+import os
+import argparse
+
+def corrupt(block):
+    with open(block, 'r+b') as file:
+        # skip rev
+        file.read(4)
+
+        # go to last commit
+        tag = 0xffffffff
+        while True:
+            try:
+                ntag, = struct.unpack('>I', file.read(4))
+            except struct.error:
+                break
+
+            tag ^= ntag
+            size = (tag & 0x3ff) if (tag & 0x3ff) != 0x3ff else 0
+            file.seek(size, os.SEEK_CUR)
+
+        # lob off last 3 bytes
+        file.seek(-(size + 3), os.SEEK_CUR)
+        file.truncate()
+
+def main(args):
+    if args.n or not args.blocks:
+        with open('blocks/.history', 'rb') as file:
+            for i in range(int(args.n or 1)):
+                last, = struct.unpack('<I', file.read(4))
+                args.blocks.append('blocks/%x' % last)
+
+    for block in args.blocks:
+        print 'corrupting %s' % block
+        corrupt(block)
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument('-n')
+    parser.add_argument('blocks', nargs='*')
+    main(parser.parse_args())

tests/debug.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python2
+
+import struct
+import binascii
+
+TYPES = {
+    (0x700, 0x400): 'splice',
+    (0x7ff, 0x401): 'create',
+    (0x7ff, 0x4ff): 'delete',
+    (0x700, 0x000): 'name',
+    (0x7ff, 0x001): 'name reg',
+    (0x7ff, 0x002): 'name dir',
+    (0x7ff, 0x0ff): 'name superblock',
+    (0x700, 0x200): 'struct',
+    (0x7ff, 0x200): 'struct dir',
+    (0x7ff, 0x202): 'struct ctz',
+    (0x7ff, 0x201): 'struct inline',
+    (0x700, 0x300): 'userattr',
+    (0x700, 0x600): 'tail',
+    (0x7ff, 0x600): 'tail soft',
+    (0x7ff, 0x601): 'tail hard',
+    (0x700, 0x700): 'gstate',
+    (0x7ff, 0x7ff): 'gstate move',
+    (0x700, 0x500): 'crc',
+}
+
+def typeof(type):
+    for prefix in range(12):
+        mask = 0x7ff & ~((1 << prefix)-1)
+        if (mask, type & mask) in TYPES:
+            return TYPES[mask, type & mask] + (
+                ' %0*x' % (prefix/4, type & ((1 << prefix)-1))
+                if prefix else '')
+    else:
+        return '%02x' % type
+
+def main(*blocks):
+    # find most recent block
+    file = None
+    rev = None
+    crc = None
+    versions = []
+
+    for block in blocks:
+        try:
+            nfile = open(block, 'rb')
+            ndata = nfile.read(4)
+            ncrc = binascii.crc32(ndata)
+            nrev, = struct.unpack('<I', ndata)
+
+            assert rev != nrev
+            if not file or ((rev - nrev) & 0x80000000):
+                file = nfile
+                rev = nrev
+                crc = ncrc
+
+            versions.append((nrev, '%s (rev %d)' % (block, nrev)))
+        except (IOError, struct.error):
+            pass
+
+    if not file:
+        print 'Bad metadata pair {%s}' % ', '.join(blocks)
+        return 1
+
+    print "--- %s ---" % ', '.join(v for _,v in sorted(versions, reverse=True))
+
+    # go through each tag, print useful information
+    print "%-4s  %-8s  %-14s  %3s %4s  %s" % (
+        'off', 'tag', 'type', 'id', 'len', 'dump')
+
+    tag = 0xffffffff
+    off = 4
+    while True:
+        try:
+            data = file.read(4)
+            crc = binascii.crc32(data, crc)
+            ntag, = struct.unpack('>I', data)
+        except struct.error:
+            break
+
+        tag ^= ntag
+        off += 4
+
+        type = (tag & 0x7ff00000) >> 20
+        id   = (tag & 0x000ffc00) >> 10
+        size = (tag & 0x000003ff) >> 0
+        iscrc = (type & 0x700) == 0x500
+
+        data = file.read(size if size != 0x3ff else 0)
+        if iscrc:
+            crc = binascii.crc32(data[:4], crc)
+        else:
+            crc = binascii.crc32(data, crc)
+
+        print '%04x: %08x  %-15s %3s %4s  %-23s  %-8s' % (
+            off, tag,
+            typeof(type) + (' bad!' if iscrc and ~crc else ''),
+            id if id != 0x3ff else '.',
+            size if size != 0x3ff else 'x',
+            ' '.join('%02x' % ord(c) for c in data[:8]),
+            ''.join(c if c >= ' ' and c <= '~' else '.' for c in data[:8]))
+
+        off += size if size != 0x3ff else 0
+        if iscrc:
+            crc = 0
+            tag ^= (type & 1) << 31
+
+    return 0
+
+if __name__ == "__main__":
+    import sys
+    sys.exit(main(*sys.argv[1:]))

tests/stats.py

@@ -7,7 +7,7 @@ import os
 import re
 
 def main():
-    with open('blocks/config') as file:
+    with open('blocks/.config') as file:
         s = struct.unpack('<LLLL', file.read())
         print 'read_size: %d' % s[0]
         print 'prog_size: %d' % s[1]
@@ -18,7 +18,7 @@ def main():
         os.path.getsize(os.path.join('blocks', f))
         for f in os.listdir('blocks') if re.match('\d+', f))
 
-    with open('blocks/stats') as file:
+    with open('blocks/.stats') as file:
         s = struct.unpack('<QQQ', file.read())
         print 'read_count: %d' % s[0]
         print 'prog_count: %d' % s[1]

tests/template.fmt

@@ -1,17 +1,17 @@
 /// AUTOGENERATED TEST ///
-#include "lfs.h"
+#include "lfs2.h"
-#include "emubd/lfs_emubd.h"
+#include "emubd/lfs2_emubd.h"
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 
 
 // test stuff
-void test_log(const char *s, uintmax_t v) {{
+static void test_log(const char *s, uintmax_t v) {{
     printf("%s: %jd\n", s, v);
 }}
 
-void test_assert(const char *file, unsigned line,
+static void test_assert(const char *file, unsigned line,
         const char *s, uintmax_t v, uintmax_t e) {{
     static const char *last[6] = {{0, 0}};
     if (v != e || !(last[0] == s || last[1] == s ||
@@ -27,8 +27,8 @@ void test_assert(const char *file, unsigned line,
     }}
 
     if (v != e) {{
-        printf("\033[31m%s:%u: assert %s failed, expected %jd\033[0m\n",
+        fprintf(stderr, "\033[31m%s:%u: assert %s failed with %jd, "
-                file, line, s, e);
+                "expected %jd\033[0m\n", file, line, s, v, e);
         exit(-2);
     }}
 }}
@@ -37,69 +37,80 @@ void test_assert(const char *file, unsigned line,
 
 
 // utility functions for traversals
-int test_count(void *p, lfs_block_t b) {{
+static int __attribute__((used)) test_count(void *p, lfs2_block_t b) {{
+    (void)b;
     unsigned *u = (unsigned*)p;
     *u += 1;
     return 0;
 }}
 
 
-// lfs declarations
+// lfs2 declarations
-lfs_t lfs;
+lfs2_t lfs2;
-lfs_emubd_t bd;
+lfs2_emubd_t bd;
-lfs_file_t file[4];
+lfs2_file_t file[4];
-lfs_dir_t dir[4];
+lfs2_dir_t dir[4];
-struct lfs_info info;
+struct lfs2_info info;
 
 uint8_t buffer[1024];
 uint8_t wbuffer[1024];
 uint8_t rbuffer[1024];
-lfs_size_t size;
+lfs2_size_t size;
-lfs_size_t wsize;
+lfs2_size_t wsize;
-lfs_size_t rsize;
+lfs2_size_t rsize;
 
-uintmax_t res;
+uintmax_t test;
 
-#ifndef LFS_READ_SIZE
+#ifndef LFS2_READ_SIZE
-#define LFS_READ_SIZE 16
+#define LFS2_READ_SIZE 16
 #endif
 
-#ifndef LFS_PROG_SIZE
+#ifndef LFS2_PROG_SIZE
-#define LFS_PROG_SIZE 16
+#define LFS2_PROG_SIZE LFS2_READ_SIZE
 #endif
 
-#ifndef LFS_BLOCK_SIZE
+#ifndef LFS2_BLOCK_SIZE
-#define LFS_BLOCK_SIZE 512
+#define LFS2_BLOCK_SIZE 512
 #endif
 
-#ifndef LFS_BLOCK_COUNT
+#ifndef LFS2_BLOCK_COUNT
-#define LFS_BLOCK_COUNT 1024
+#define LFS2_BLOCK_COUNT 1024
 #endif
 
-#ifndef LFS_LOOKAHEAD
+#ifndef LFS2_BLOCK_CYCLES
-#define LFS_LOOKAHEAD 128
+#define LFS2_BLOCK_CYCLES 1024
 #endif
 
-const struct lfs_config cfg = {{
+#ifndef LFS2_CACHE_SIZE
+#define LFS2_CACHE_SIZE 64
+#endif
+
+#ifndef LFS2_LOOKAHEAD_SIZE
+#define LFS2_LOOKAHEAD_SIZE 16
+#endif
+
+const struct lfs2_config cfg = {{
     .context = &bd,
-    .read  = &lfs_emubd_read,
+    .read  = &lfs2_emubd_read,
-    .prog  = &lfs_emubd_prog,
+    .prog  = &lfs2_emubd_prog,
-    .erase = &lfs_emubd_erase,
+    .erase = &lfs2_emubd_erase,
-    .sync  = &lfs_emubd_sync,
+    .sync  = &lfs2_emubd_sync,
 
-    .read_size   = LFS_READ_SIZE,
+    .read_size      = LFS2_READ_SIZE,
-    .prog_size   = LFS_PROG_SIZE,
+    .prog_size      = LFS2_PROG_SIZE,
-    .block_size  = LFS_BLOCK_SIZE,
+    .block_size     = LFS2_BLOCK_SIZE,
-    .block_count = LFS_BLOCK_COUNT,
+    .block_count    = LFS2_BLOCK_COUNT,
-    .lookahead   = LFS_LOOKAHEAD,
+    .block_cycles   = LFS2_BLOCK_CYCLES,
+    .cache_size     = LFS2_CACHE_SIZE,
+    .lookahead_size = LFS2_LOOKAHEAD_SIZE,
 }};
 
 
 // Entry point
-int main() {{
+int main(void) {{
-    lfs_emubd_create(&cfg, "blocks");
+    lfs2_emubd_create(&cfg, "blocks");
 
 {tests}
 
-    lfs_emubd_destroy(&cfg);
+    lfs2_emubd_destroy(&cfg);
 }}

tests/test.py

@@ -10,26 +10,38 @@ def generate(test):
         template = file.read()
 
     lines = []
-    for line in re.split('(?<=[;{}])\n', test.read()):
+    for line in re.split('(?<=(?:.;| [{}]))\n', test.read()):
         match = re.match('(?: *\n)*( *)(.*)=>(.*);', line, re.DOTALL | re.MULTILINE)
         if match:
             tab, test, expect = match.groups()
-            lines.append(tab+'res = {test};'.format(test=test.strip()))
+            lines.append(tab+'test = {test};'.format(test=test.strip()))
-            lines.append(tab+'test_assert("{name}", res, {expect});'.format(
+            lines.append(tab+'test_assert("{name}", test, {expect});'.format(
                     name = re.match('\w*', test.strip()).group(),
                     expect = expect.strip()))
         else:
             lines.append(line)
 
+    # Create test file
     with open('test.c', 'w') as file:
         file.write(template.format(tests='\n'.join(lines)))
 
+    # Remove build artifacts to force rebuild
+    try:
+        os.remove('test.o')
+        os.remove('lfs2')
+    except OSError:
+        pass
+
 def compile():
-    os.environ['CFLAGS'] = os.environ.get('CFLAGS', '') + ' -Werror'
+    subprocess.check_call([
-    subprocess.check_call(['make', '--no-print-directory', '-s'], env=os.environ)
+            os.environ.get('MAKE', 'make'),
+            '--no-print-directory', '-s'])
 
 def execute():
-    subprocess.check_call(["./lfs"])
+    if 'EXEC' in os.environ:
+        subprocess.check_call([os.environ['EXEC'], "./lfs2"])
+    else:
+        subprocess.check_call(["./lfs2"])
 
 def main(test=None):
     if test and not test.startswith('-'):

tests/test_alloc.sh

@@ -4,258 +4,482 @@ set -eu
 echo "=== Allocator tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 TEST
 
 SIZE=15000
 
-lfs_mkdir() {
+lfs2_mkdir() {
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "$1") => 0;
+    lfs2_mkdir(&lfs2, "$1") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
-lfs_remove() {
+lfs2_remove() {
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_remove(&lfs, "$1/eggs") => 0;
+    lfs2_remove(&lfs2, "$1/eggs") => 0;
-    lfs_remove(&lfs, "$1/bacon") => 0;
+    lfs2_remove(&lfs2, "$1/bacon") => 0;
-    lfs_remove(&lfs, "$1/pancakes") => 0;
+    lfs2_remove(&lfs2, "$1/pancakes") => 0;
-    lfs_remove(&lfs, "$1") => 0;
+    lfs2_remove(&lfs2, "$1") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
-lfs_alloc_singleproc() {
+lfs2_alloc_singleproc() {
 tests/test.py << TEST
     const char *names[] = {"bacon", "eggs", "pancakes"};
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    for (int n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
+    for (unsigned n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
         sprintf((char*)buffer, "$1/%s", names[n]);
-        lfs_file_open(&lfs, &file[n], (char*)buffer,
+        lfs2_file_open(&lfs2, &file[n], (char*)buffer,
-                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+                LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_APPEND) => 0;
     }
-    for (int n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
+    for (unsigned n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
         size = strlen(names[n]);
         for (int i = 0; i < $SIZE; i++) {
-            lfs_file_write(&lfs, &file[n], names[n], size) => size;
+            lfs2_file_write(&lfs2, &file[n], names[n], size) => size;
         }
     }
-    for (int n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
+    for (unsigned n = 0; n < sizeof(names)/sizeof(names[0]); n++) {
-        lfs_file_close(&lfs, &file[n]) => 0;
+        lfs2_file_close(&lfs2, &file[n]) => 0;
     }
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
-lfs_alloc_multiproc() {
+lfs2_alloc_multiproc() {
 for name in bacon eggs pancakes
 do
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$1/$name",
+    lfs2_file_open(&lfs2, &file[0], "$1/$name",
-            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+            LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_APPEND) => 0;
     size = strlen("$name");
     memcpy(buffer, "$name", size);
     for (int i = 0; i < $SIZE; i++) {
-        lfs_file_write(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 done
 }
 
-lfs_verify() {
+lfs2_verify() {
 for name in bacon eggs pancakes
 do
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$1/$name", LFS_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[0], "$1/$name", LFS2_O_RDONLY) => 0;
     size = strlen("$name");
     for (int i = 0; i < $SIZE; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
         memcmp(buffer, "$name", size) => 0;
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 done
 }
 
 echo "--- Single-process allocation test ---"
-lfs_mkdir singleproc
+lfs2_mkdir singleproc
-lfs_alloc_singleproc singleproc
+lfs2_alloc_singleproc singleproc
-lfs_verify singleproc
+lfs2_verify singleproc
 
 echo "--- Multi-process allocation test ---"
-lfs_mkdir multiproc
+lfs2_mkdir multiproc
-lfs_alloc_multiproc multiproc
+lfs2_alloc_multiproc multiproc
-lfs_verify multiproc
+lfs2_verify multiproc
-lfs_verify singleproc
+lfs2_verify singleproc
 
 echo "--- Single-process reuse test ---"
-lfs_remove singleproc
+lfs2_remove singleproc
-lfs_mkdir singleprocreuse
+lfs2_mkdir singleprocreuse
-lfs_alloc_singleproc singleprocreuse
+lfs2_alloc_singleproc singleprocreuse
-lfs_verify singleprocreuse
+lfs2_verify singleprocreuse
-lfs_verify multiproc
+lfs2_verify multiproc
 
 echo "--- Multi-process reuse test ---"
-lfs_remove multiproc
+lfs2_remove multiproc
-lfs_mkdir multiprocreuse
+lfs2_mkdir multiprocreuse
-lfs_alloc_singleproc multiprocreuse
+lfs2_alloc_singleproc multiprocreuse
-lfs_verify multiprocreuse
+lfs2_verify multiprocreuse
-lfs_verify singleprocreuse
+lfs2_verify singleprocreuse
 
 echo "--- Cleanup ---"
-lfs_remove multiprocreuse
+lfs2_remove multiprocreuse
-lfs_remove singleprocreuse
+lfs2_remove singleprocreuse
 
 echo "--- Exhaustion test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
     size = strlen("exhaustion");
     memcpy(buffer, "exhaustion", size);
-    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
 
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
-    lfs_ssize_t res;
+    lfs2_ssize_t res;
     while (true) {
-        res = lfs_file_write(&lfs, &file[0], buffer, size);
+        res = lfs2_file_write(&lfs2, &file[0], buffer, size);
         if (res < 0) {
             break;
         }
 
         res => size;
     }
-    res => LFS_ERR_NOSPC;
+    res => LFS2_ERR_NOSPC;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_RDONLY);
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_RDONLY);
     size = strlen("exhaustion");
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_size(&lfs2, &file[0]) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "exhaustion", size) => 0;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Exhaustion wraparound test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_remove(&lfs, "exhaustion") => 0;
+    lfs2_remove(&lfs2, "exhaustion") => 0;
 
-    lfs_file_open(&lfs, &file[0], "padding", LFS_O_WRONLY | LFS_O_CREAT);
+    lfs2_file_open(&lfs2, &file[0], "padding", LFS2_O_WRONLY | LFS2_O_CREAT);
     size = strlen("buffering");
     memcpy(buffer, "buffering", size);
     for (int i = 0; i < $SIZE; i++) {
-        lfs_file_write(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_remove(&lfs, "padding") => 0;
+    lfs2_remove(&lfs2, "padding") => 0;
 
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
     size = strlen("exhaustion");
     memcpy(buffer, "exhaustion", size);
-    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
 
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
-    lfs_ssize_t res;
+    lfs2_ssize_t res;
     while (true) {
-        res = lfs_file_write(&lfs, &file[0], buffer, size);
+        res = lfs2_file_write(&lfs2, &file[0], buffer, size);
         if (res < 0) {
             break;
         }
 
         res => size;
     }
-    res => LFS_ERR_NOSPC;
+    res => LFS2_ERR_NOSPC;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_RDONLY);
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_RDONLY);
     size = strlen("exhaustion");
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_size(&lfs2, &file[0]) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "exhaustion", size) => 0;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_remove(&lfs2, "exhaustion") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Dir exhaustion test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "exhaustion", &info) => 0;
-    lfs_size_t fullsize = info.size;
-    lfs_remove(&lfs, "exhaustion") => 0;
 
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
+    // find out max file size
+    lfs2_mkdir(&lfs2, "exhaustiondir") => 0;
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
-    for (lfs_size_t i = 0; i < fullsize - 2*512; i += size) {
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
-        lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    int count = 0;
+    int err;
+    while (true) {
+        err = lfs2_file_write(&lfs2, &file[0], buffer, size);
+        if (err < 0) {
+            break;
+        }
+
+        count += 1;
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    err => LFS2_ERR_NOSPC;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
 
-    lfs_mkdir(&lfs, "exhaustiondir") => 0;
+    lfs2_remove(&lfs2, "exhaustion") => 0;
-    lfs_remove(&lfs, "exhaustiondir") => 0;
+    lfs2_remove(&lfs2, "exhaustiondir") => 0;
 
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_APPEND);
+    // see if dir fits with max file size
-    size = strlen("blahblahblahblah");
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
-    memcpy(buffer, "blahblahblahblah", size);
+    for (int i = 0; i < count; i++) {
-    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
 
-    lfs_mkdir(&lfs, "exhaustiondir") => LFS_ERR_NOSPC;
+    lfs2_mkdir(&lfs2, "exhaustiondir") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_remove(&lfs2, "exhaustiondir") => 0;
+    lfs2_remove(&lfs2, "exhaustion") => 0;
+
+    // see if dir fits with > max file size
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
+    for (int i = 0; i < count+1; i++) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_mkdir(&lfs2, "exhaustiondir") => LFS2_ERR_NOSPC;
+
+    lfs2_remove(&lfs2, "exhaustion") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Chained dir exhaustion test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "exhaustion", &info) => 0;
-    lfs_size_t fullsize = info.size;
 
-    lfs_remove(&lfs, "exhaustion") => 0;
+    // find out max file size
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
+    lfs2_mkdir(&lfs2, "exhaustiondir") => 0;
-    size = strlen("blahblahblahblah");
+    for (int i = 0; i < 10; i++) {
-    memcpy(buffer, "blahblahblahblah", size);
-    for (lfs_size_t i = 0; i < fullsize - 19*512; i += size) {
-        lfs_file_write(&lfs, &file[0], buffer, size) => size;
-    }
-    lfs_file_close(&lfs, &file[0]) => 0;
-
-    for (int i = 0; i < 9; i++) {
         sprintf((char*)buffer, "dirwithanexhaustivelylongnameforpadding%d", i);
-        lfs_mkdir(&lfs, (char*)buffer) => 0;
+        lfs2_mkdir(&lfs2, (char*)buffer) => 0;
     }
-
-    lfs_mkdir(&lfs, "exhaustiondir") => LFS_ERR_NOSPC;
-
-    lfs_remove(&lfs, "exhaustion") => 0;
-    lfs_file_open(&lfs, &file[0], "exhaustion", LFS_O_WRONLY | LFS_O_CREAT);
     size = strlen("blahblahblahblah");
     memcpy(buffer, "blahblahblahblah", size);
-    for (lfs_size_t i = 0; i < fullsize - 20*512; i += size) {
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
-        lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    int count = 0;
-    }
+    int err;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    while (true) {
+        err = lfs2_file_write(&lfs2, &file[0], buffer, size);
+        if (err < 0) {
+            break;
+        }
 
-    lfs_mkdir(&lfs, "exhaustiondir") => 0;
+        count += 1;
-    lfs_mkdir(&lfs, "exhaustiondir2") => LFS_ERR_NOSPC;
+    }
+    err => LFS2_ERR_NOSPC;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_remove(&lfs2, "exhaustion") => 0;
+    lfs2_remove(&lfs2, "exhaustiondir") => 0;
+    for (int i = 0; i < 10; i++) {
+        sprintf((char*)buffer, "dirwithanexhaustivelylongnameforpadding%d", i);
+        lfs2_remove(&lfs2, (char*)buffer) => 0;
+    }
+
+    // see that chained dir fails
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
+    for (int i = 0; i < count+1; i++) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
+
+    for (int i = 0; i < 10; i++) {
+        sprintf((char*)buffer, "dirwithanexhaustivelylongnameforpadding%d", i);
+        lfs2_mkdir(&lfs2, (char*)buffer) => 0;
+    }
+
+    lfs2_mkdir(&lfs2, "exhaustiondir") => LFS2_ERR_NOSPC;
+
+    // shorten file to try a second chained dir
+    while (true) {
+        err = lfs2_mkdir(&lfs2, "exhaustiondir");
+        if (err != LFS2_ERR_NOSPC) {
+            break;
+        }
+
+        lfs2_ssize_t filesize = lfs2_file_size(&lfs2, &file[0]);
+        filesize > 0 => true;
+
+        lfs2_file_truncate(&lfs2, &file[0], filesize - size) => 0;
+        lfs2_file_sync(&lfs2, &file[0]) => 0;
+    }
+    err => 0;
+
+    lfs2_mkdir(&lfs2, "exhaustiondir2") => LFS2_ERR_NOSPC;
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
+echo "--- Split dir test ---"
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // create one block hole for half a directory
+    lfs2_file_open(&lfs2, &file[0], "bump", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    for (lfs2_size_t i = 0; i < cfg.block_size; i += 2) {
+        memcpy(&buffer[i], "hi", 2);
+    }
+    lfs2_file_write(&lfs2, &file[0], buffer, cfg.block_size) => cfg.block_size;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "exhaustion", LFS2_O_WRONLY | LFS2_O_CREAT);
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < (cfg.block_count-4)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    // remount to force reset of lookahead
+    lfs2_unmount(&lfs2) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // open hole
+    lfs2_remove(&lfs2, "bump") => 0;
+
+    lfs2_mkdir(&lfs2, "splitdir") => 0;
+    lfs2_file_open(&lfs2, &file[0], "splitdir/bump",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    for (lfs2_size_t i = 0; i < cfg.block_size; i += 2) {
+        memcpy(&buffer[i], "hi", 2);
+    }
+    lfs2_file_write(&lfs2, &file[0], buffer, 2*cfg.block_size) => LFS2_ERR_NOSPC;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Outdated lookahead test ---"
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // fill completely with two files
+    lfs2_file_open(&lfs2, &file[0], "exhaustion1",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "exhaustion2",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    // remount to force reset of lookahead
+    lfs2_unmount(&lfs2) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // rewrite one file
+    lfs2_file_open(&lfs2, &file[0], "exhaustion1",
+            LFS2_O_WRONLY | LFS2_O_TRUNC) => 0;
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    // rewrite second file, this requires lookahead does not
+    // use old population
+    lfs2_file_open(&lfs2, &file[0], "exhaustion2",
+            LFS2_O_WRONLY | LFS2_O_TRUNC) => 0;
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+TEST
+
+echo "--- Outdated lookahead and split dir test ---"
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // fill completely with two files
+    lfs2_file_open(&lfs2, &file[0], "exhaustion1",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "exhaustion2",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2+1)/2)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    // remount to force reset of lookahead
+    lfs2_unmount(&lfs2) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    // rewrite one file with a hole of one block
+    lfs2_file_open(&lfs2, &file[0], "exhaustion1",
+            LFS2_O_WRONLY | LFS2_O_TRUNC) => 0;
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
+    size = strlen("blahblahblahblah");
+    memcpy(buffer, "blahblahblahblah", size);
+    for (lfs2_size_t i = 0;
+            i < ((cfg.block_count-2)/2 - 1)*(cfg.block_size-8);
+            i += size) {
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+    }
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    // try to allocate a directory, should fail!
+    lfs2_mkdir(&lfs2, "split") => LFS2_ERR_NOSPC;
+
+    // file should not fail
+    lfs2_file_open(&lfs2, &file[0], "notasplit",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_write(&lfs2, &file[0], "hi", 2) => 2;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
 
 echo "--- Results ---"
 tests/stats.py

tests/test_attrs.sh

@@ -0,0 +1,286 @@
+#!/bin/bash
+set -eu
+
+echo "=== Attr tests ==="
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "hello") => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/hello",
+            LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_write(&lfs2, &file[0], "hello", strlen("hello"))
+            => strlen("hello");
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Set/get attribute ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_setattr(&lfs2, "hello", 'A', "aaaa",   4) => 0;
+    lfs2_setattr(&lfs2, "hello", 'B', "bbbbbb", 6) => 0;
+    lfs2_setattr(&lfs2, "hello", 'C', "ccccc",  5) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => 6;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "bbbbbb", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    lfs2_setattr(&lfs2, "hello", 'B', "", 0) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => 0;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",         4) => 0;
+    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",        5) => 0;
+
+    lfs2_removeattr(&lfs2, "hello", 'B') => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => LFS2_ERR_NOATTR;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",         4) => 0;
+    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",        5) => 0;
+
+    lfs2_setattr(&lfs2, "hello", 'B', "dddddd", 6) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => 6;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "dddddd", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    lfs2_setattr(&lfs2, "hello", 'B', "eee", 3) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => 3;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",     5) => 0;
+
+    lfs2_setattr(&lfs2, "hello", 'A', buffer, LFS2_ATTR_MAX+1) => LFS2_ERR_NOSPC;
+    lfs2_setattr(&lfs2, "hello", 'B', "fffffffff", 9) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  6) => 9;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+10, 5) => 5;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_getattr(&lfs2, "hello", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "hello", 'B', buffer+4,  9) => 9;
+    lfs2_getattr(&lfs2, "hello", 'C', buffer+13, 5) => 5;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "fffffffff", 9) => 0;
+    memcmp(buffer+13, "ccccc",     5) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, sizeof(buffer)) => strlen("hello");
+    memcmp(buffer, "hello", strlen("hello")) => 0;
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Set/get root attribute ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_setattr(&lfs2, "/", 'A', "aaaa",   4) => 0;
+    lfs2_setattr(&lfs2, "/", 'B', "bbbbbb", 6) => 0;
+    lfs2_setattr(&lfs2, "/", 'C', "ccccc",  5) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => 6;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "bbbbbb", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    lfs2_setattr(&lfs2, "/", 'B', "", 0) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => 0;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",         4) => 0;
+    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",        5) => 0;
+
+    lfs2_removeattr(&lfs2, "/", 'B') => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => LFS2_ERR_NOATTR;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",         4) => 0;
+    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",        5) => 0;
+
+    lfs2_setattr(&lfs2, "/", 'B', "dddddd", 6) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => 6;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "dddddd", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    lfs2_setattr(&lfs2, "/", 'B', "eee", 3) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => 3;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",     5) => 0;
+
+    lfs2_setattr(&lfs2, "/", 'A', buffer, LFS2_ATTR_MAX+1) => LFS2_ERR_NOSPC;
+    lfs2_setattr(&lfs2, "/", 'B', "fffffffff", 9) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  6) => 9;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+10, 5) => 5;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_getattr(&lfs2, "/", 'A', buffer,    4) => 4;
+    lfs2_getattr(&lfs2, "/", 'B', buffer+4,  9) => 9;
+    lfs2_getattr(&lfs2, "/", 'C', buffer+13, 5) => 5;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "fffffffff", 9) => 0;
+    memcmp(buffer+13, "ccccc",     5) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, sizeof(buffer)) => strlen("hello");
+    memcmp(buffer, "hello", strlen("hello")) => 0;
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Set/get file attribute ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    struct lfs2_attr attrs1[] = {
+        {'A', buffer,    4},
+        {'B', buffer+4,  6},
+        {'C', buffer+10, 5},
+    };
+    struct lfs2_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
+
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1) => 0;
+    memcpy(buffer,    "aaaa",   4);
+    memcpy(buffer+4,  "bbbbbb", 6);
+    memcpy(buffer+10, "ccccc",  5);
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memset(buffer, 0, 15);
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "bbbbbb", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    attrs1[1].size = 0;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memset(buffer, 0, 15);
+    attrs1[1].size = 6;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memcmp(buffer,    "aaaa",         4) => 0;
+    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",        5) => 0;
+
+    attrs1[1].size = 6;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1) => 0;
+    memcpy(buffer+4,  "dddddd", 6);
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memset(buffer, 0, 15);
+    attrs1[1].size = 6;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memcmp(buffer,    "aaaa",   4) => 0;
+    memcmp(buffer+4,  "dddddd", 6) => 0;
+    memcmp(buffer+10, "ccccc",  5) => 0;
+
+    attrs1[1].size = 3;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1) => 0;
+    memcpy(buffer+4,  "eee", 3);
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memset(buffer, 0, 15);
+    attrs1[1].size = 6;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
+    memcmp(buffer+10, "ccccc",     5) => 0;
+
+    attrs1[0].size = LFS2_ATTR_MAX+1;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1)
+        => LFS2_ERR_NOSPC;
+
+    struct lfs2_attr attrs2[] = {
+        {'A', buffer,    4},
+        {'B', buffer+4,  9},
+        {'C', buffer+13, 5},
+    };
+    struct lfs2_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDWR, &cfg2) => 0;
+    memcpy(buffer+4,  "fffffffff", 9);
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    attrs1[0].size = 4;
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg1) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    struct lfs2_attr attrs2[] = {
+        {'A', buffer,    4},
+        {'B', buffer+4,  9},
+        {'C', buffer+13, 5},
+    };
+    struct lfs2_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
+
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY, &cfg2) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    memcmp(buffer,    "aaaa",      4) => 0;
+    memcmp(buffer+4,  "fffffffff", 9) => 0;
+    memcmp(buffer+13, "ccccc",     5) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "hello/hello", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, sizeof(buffer)) => strlen("hello");
+    memcmp(buffer, "hello", strlen("hello")) => 0;
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Deferred file attributes ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    struct lfs2_attr attrs1[] = {
+        {'B', "gggg", 4},
+        {'C', "",     0},
+        {'D', "hhhh", 4},
+    };
+    struct lfs2_file_config cfg1 = {.attrs=attrs1, .attr_count=3};
+
+    lfs2_file_opencfg(&lfs2, &file[0], "hello/hello", LFS2_O_WRONLY, &cfg1) => 0;
+
+    lfs2_getattr(&lfs2, "hello/hello", 'B', buffer,    9) => 9;
+    lfs2_getattr(&lfs2, "hello/hello", 'C', buffer+9,  9) => 5;
+    lfs2_getattr(&lfs2, "hello/hello", 'D', buffer+18, 9) => LFS2_ERR_NOATTR;
+    memcmp(buffer,    "fffffffff",          9) => 0;
+    memcmp(buffer+9,  "ccccc\0\0\0\0",      9) => 0;
+    memcmp(buffer+18, "\0\0\0\0\0\0\0\0\0", 9) => 0;
+
+    lfs2_file_sync(&lfs2, &file[0]) => 0;
+    lfs2_getattr(&lfs2, "hello/hello", 'B', buffer,    9) => 4;
+    lfs2_getattr(&lfs2, "hello/hello", 'C', buffer+9,  9) => 0;
+    lfs2_getattr(&lfs2, "hello/hello", 'D', buffer+18, 9) => 4;
+    memcmp(buffer,    "gggg\0\0\0\0\0",     9) => 0;
+    memcmp(buffer+9,  "\0\0\0\0\0\0\0\0\0", 9) => 0;
+    memcmp(buffer+18, "hhhh\0\0\0\0\0",     9) => 0;
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Results ---"
+tests/stats.py

tests/test_corrupt.sh

@@ -6,101 +6,113 @@ echo "=== Corrupt tests ==="
 NAMEMULT=64
 FILEMULT=1
 
-lfs_mktree() {
+lfs2_mktree() {
 tests/test.py ${1:-} << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < $NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
         buffer[$NAMEMULT] = '\0';
-        lfs_mkdir(&lfs, (char*)buffer) => 0;
+        lfs2_mkdir(&lfs2, (char*)buffer) => 0;
 
         buffer[$NAMEMULT] = '/';
         for (int j = 0; j < $NAMEMULT; j++) {
             buffer[j+$NAMEMULT+1] = '0'+i;
         }
         buffer[2*$NAMEMULT+1] = '\0';
-        lfs_file_open(&lfs, &file[0], (char*)buffer,
+        lfs2_file_open(&lfs2, &file[0], (char*)buffer,
-                LFS_O_WRONLY | LFS_O_CREAT) => 0;
+                LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
         
         size = $NAMEMULT;
         for (int j = 0; j < i*$FILEMULT; j++) {
-            lfs_file_write(&lfs, &file[0], buffer, size) => size;
+            lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
         }
 
-        lfs_file_close(&lfs, &file[0]) => 0;
+        lfs2_file_close(&lfs2, &file[0]) => 0;
     }
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
-lfs_chktree() {
+lfs2_chktree() {
 tests/test.py ${1:-} << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
     for (int i = 1; i < 10; i++) {
         for (int j = 0; j < $NAMEMULT; j++) {
             buffer[j] = '0'+i;
         }
         buffer[$NAMEMULT] = '\0';
-        lfs_stat(&lfs, (char*)buffer, &info) => 0;
+        lfs2_stat(&lfs2, (char*)buffer, &info) => 0;
-        info.type => LFS_TYPE_DIR;
+        info.type => LFS2_TYPE_DIR;
 
         buffer[$NAMEMULT] = '/';
         for (int j = 0; j < $NAMEMULT; j++) {
             buffer[j+$NAMEMULT+1] = '0'+i;
         }
         buffer[2*$NAMEMULT+1] = '\0';
-        lfs_file_open(&lfs, &file[0], (char*)buffer, LFS_O_RDONLY) => 0;
+        lfs2_file_open(&lfs2, &file[0], (char*)buffer, LFS2_O_RDONLY) => 0;
         
         size = $NAMEMULT;
         for (int j = 0; j < i*$FILEMULT; j++) {
-            lfs_file_read(&lfs, &file[0], rbuffer, size) => size;
+            lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
             memcmp(buffer, rbuffer, size) => 0;
         }
 
-        lfs_file_close(&lfs, &file[0]) => 0;
+        lfs2_file_close(&lfs2, &file[0]) => 0;
     }
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
 echo "--- Sanity check ---"
 rm -rf blocks
-lfs_mktree
+lfs2_mktree
-lfs_chktree
+lfs2_chktree
+BLOCKS="$(ls blocks | grep -vw '[01]')"
 
 echo "--- Block corruption ---"
-for i in {0..33}
+for b in $BLOCKS
 do 
     rm -rf blocks
     mkdir blocks
-    ln -s /dev/zero blocks/$(printf '%x' $i)
+    ln -s /dev/zero blocks/$b
-    lfs_mktree
+    lfs2_mktree
-    lfs_chktree
+    lfs2_chktree
+done
+
+echo "--- Block persistance ---"
+for b in $BLOCKS
+do 
+    rm -rf blocks
+    mkdir blocks
+    lfs2_mktree
+    chmod a-w blocks/$b || true
+    lfs2_mktree
+    lfs2_chktree
 done
 
 echo "--- Big region corruption ---"
 rm -rf blocks
 mkdir blocks
-for i in {2..255}
+for i in {2..512}
 do
     ln -s /dev/zero blocks/$(printf '%x' $i)
 done
-lfs_mktree
+lfs2_mktree
-lfs_chktree
+lfs2_chktree
 
 echo "--- Alternating corruption ---"
 rm -rf blocks
 mkdir blocks
-for i in {2..511..2}
+for i in {2..1024..2}
 do
     ln -s /dev/zero blocks/$(printf '%x' $i)
 done
-lfs_mktree
+lfs2_mktree
-lfs_chktree
+lfs2_chktree
 
 echo "--- Results ---"
 tests/stats.py

tests/test_dirs.sh

@@ -6,281 +6,478 @@ LARGESIZE=128
 echo "=== Directory tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 TEST
 
 echo "--- Root directory ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Directory creation ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "potato") => 0;
+    lfs2_mkdir(&lfs2, "potato") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- File creation ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "burito", LFS_O_CREAT | LFS_O_WRONLY) => 0;
+    lfs2_file_open(&lfs2, &file[0], "burito", LFS2_O_CREAT | LFS2_O_WRONLY) => 0;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Directory iteration ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "potato") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "burito") => 0;
-    info.type => LFS_TYPE_REG;
+    info.type => LFS2_TYPE_REG;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "potato") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Directory failures ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "potato") => LFS_ERR_EXISTS;
+    lfs2_mkdir(&lfs2, "potato") => LFS2_ERR_EXIST;
-    lfs_dir_open(&lfs, &dir[0], "tomato") => LFS_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "tomato") => LFS2_ERR_NOENT;
-    lfs_dir_open(&lfs, &dir[0], "burito") => LFS_ERR_NOTDIR;
+    lfs2_dir_open(&lfs2, &dir[0], "burito") => LFS2_ERR_NOTDIR;
-    lfs_file_open(&lfs, &file[0], "tomato", LFS_O_RDONLY) => LFS_ERR_NOENT;
+    lfs2_file_open(&lfs2, &file[0], "tomato", LFS2_O_RDONLY) => LFS2_ERR_NOENT;
-    lfs_file_open(&lfs, &file[0], "potato", LFS_O_RDONLY) => LFS_ERR_ISDIR;
+    lfs2_file_open(&lfs2, &file[0], "potato", LFS2_O_RDONLY) => LFS2_ERR_ISDIR;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Nested directories ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "potato/baked") => 0;
+    lfs2_mkdir(&lfs2, "potato/baked") => 0;
-    lfs_mkdir(&lfs, "potato/sweet") => 0;
+    lfs2_mkdir(&lfs2, "potato/sweet") => 0;
-    lfs_mkdir(&lfs, "potato/fried") => 0;
+    lfs2_mkdir(&lfs2, "potato/fried") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "potato") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "potato") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "baked") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "sweet") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "fried") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "sweet") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Multi-block directory ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "cactus") => 0;
+    lfs2_mkdir(&lfs2, "cactus") => 0;
     for (int i = 0; i < $LARGESIZE; i++) {
-        sprintf((char*)buffer, "cactus/test%d", i);
+        sprintf((char*)buffer, "cactus/test%03d", i);
-        lfs_mkdir(&lfs, (char*)buffer) => 0;
+        lfs2_mkdir(&lfs2, (char*)buffer) => 0;
     }
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "cactus") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "cactus") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
     for (int i = 0; i < $LARGESIZE; i++) {
-        sprintf((char*)buffer, "test%d", i);
+        sprintf((char*)buffer, "test%03d", i);
-        lfs_dir_read(&lfs, &dir[0], &info) => 1;
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
         strcmp(info.name, (char*)buffer) => 0;
+        info.type => LFS2_TYPE_DIR;
     }
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Directory remove ---"
-# TESTING HERE
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_remove(&lfs, "potato") => LFS_ERR_INVAL;
+    lfs2_remove(&lfs2, "potato") => LFS2_ERR_NOTEMPTY;
-    lfs_remove(&lfs, "potato/sweet") => 0;
+    lfs2_remove(&lfs2, "potato/sweet") => 0;
-    lfs_remove(&lfs, "potato/baked") => 0;
+    lfs2_remove(&lfs2, "potato/baked") => 0;
-    lfs_remove(&lfs, "potato/fried") => 0;
+    lfs2_remove(&lfs2, "potato/fried") => 0;
 
-    lfs_dir_open(&lfs, &dir[0], "potato") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "potato") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
 
-    lfs_remove(&lfs, "potato") => 0;
+    lfs2_remove(&lfs2, "potato") => 0;
 
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "burito") => 0;
-    info.type => LFS_TYPE_REG;
+    info.type => LFS2_TYPE_REG;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "cactus") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "burito") => 0;
-    info.type => LFS_TYPE_REG;
+    info.type => LFS2_TYPE_REG;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "cactus") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Directory rename ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "coldpotato") => 0;
+    lfs2_mkdir(&lfs2, "coldpotato") => 0;
-    lfs_mkdir(&lfs, "coldpotato/baked") => 0;
+    lfs2_mkdir(&lfs2, "coldpotato/baked") => 0;
-    lfs_mkdir(&lfs, "coldpotato/sweet") => 0;
+    lfs2_mkdir(&lfs2, "coldpotato/sweet") => 0;
-    lfs_mkdir(&lfs, "coldpotato/fried") => 0;
+    lfs2_mkdir(&lfs2, "coldpotato/fried") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_rename(&lfs, "coldpotato", "hotpotato") => 0;
+    lfs2_rename(&lfs2, "coldpotato", "hotpotato") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "hotpotato") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "hotpotato") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "baked") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "sweet") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "fried") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "sweet") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "warmpotato") => 0;
+    lfs2_mkdir(&lfs2, "warmpotato") => 0;
-    lfs_mkdir(&lfs, "warmpotato/mushy") => 0;
+    lfs2_mkdir(&lfs2, "warmpotato/mushy") => 0;
-    lfs_rename(&lfs, "hotpotato", "warmpotato") => LFS_ERR_INVAL;
+    lfs2_rename(&lfs2, "hotpotato", "warmpotato") => LFS2_ERR_NOTEMPTY;
 
-    lfs_remove(&lfs, "warmpotato/mushy") => 0;
+    lfs2_remove(&lfs2, "warmpotato/mushy") => 0;
-    lfs_rename(&lfs, "hotpotato", "warmpotato") => 0;
+    lfs2_rename(&lfs2, "hotpotato", "warmpotato") => 0;
 
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "warmpotato") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "warmpotato") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "baked") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "sweet") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "fried") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "sweet") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "coldpotato") => 0;
+    lfs2_mkdir(&lfs2, "coldpotato") => 0;
-    lfs_rename(&lfs, "warmpotato/baked", "coldpotato/baked") => 0;
+    lfs2_rename(&lfs2, "warmpotato/baked", "coldpotato/baked") => 0;
-    lfs_rename(&lfs, "warmpotato/sweet", "coldpotato/sweet") => 0;
+    lfs2_rename(&lfs2, "warmpotato/sweet", "coldpotato/sweet") => 0;
-    lfs_rename(&lfs, "warmpotato/fried", "coldpotato/fried") => 0;
+    lfs2_rename(&lfs2, "warmpotato/fried", "coldpotato/fried") => 0;
-    lfs_remove(&lfs, "coldpotato") => LFS_ERR_INVAL;
+    lfs2_remove(&lfs2, "coldpotato") => LFS2_ERR_NOTEMPTY;
-    lfs_remove(&lfs, "warmpotato") => 0;
+    lfs2_remove(&lfs2, "warmpotato") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "coldpotato") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "coldpotato") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "baked") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "sweet") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "fried") => 0;
-    info.type => LFS_TYPE_DIR;
+    info.type => LFS2_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "sweet") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Recursive remove ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_remove(&lfs2, "coldpotato") => LFS2_ERR_NOTEMPTY;
+
+    lfs2_dir_open(&lfs2, &dir[0], "coldpotato") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+
+    while (true) {
+        int err = lfs2_dir_read(&lfs2, &dir[0], &info);
+        err >= 0 => 1;
+        if (err == 0) {
+            break;
+        }
+
+        strcpy((char*)buffer, "coldpotato/");
+        strcat((char*)buffer, info.name);
+        lfs2_remove(&lfs2, (char*)buffer) => 0;
+    }
+
+    lfs2_remove(&lfs2, "coldpotato") => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "burito") => 0;
+    info.type => LFS2_TYPE_REG;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "cactus") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Multi-block rename ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "cactus/test%03d", i);
+        sprintf((char*)wbuffer, "cactus/tedd%03d", i);
+        lfs2_rename(&lfs2, (char*)buffer, (char*)wbuffer) => 0;
+    }
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "cactus") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "tedd%03d", i);
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+        strcmp(info.name, (char*)buffer) => 0;
+        info.type => LFS2_TYPE_DIR;
+    }
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Multi-block remove ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_remove(&lfs2, "cactus") => LFS2_ERR_NOTEMPTY;
+
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "cactus/tedd%03d", i);
+        lfs2_remove(&lfs2, (char*)buffer) => 0;
+    }
+
+    lfs2_remove(&lfs2, "cactus") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "burito") => 0;
+    info.type => LFS2_TYPE_REG;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Multi-block directory with files ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "prickly-pear") => 0;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "prickly-pear/test%03d", i);
+        lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+                LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+        size = 6;
+        memcpy(wbuffer, "Hello", size);
+        lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+        lfs2_file_close(&lfs2, &file[0]) => 0;
+    }
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "prickly-pear") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "test%03d", i);
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+        strcmp(info.name, (char*)buffer) => 0;
+        info.type => LFS2_TYPE_REG;
+        info.size => 6;
+    }
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Multi-block rename with files ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "prickly-pear/test%03d", i);
+        sprintf((char*)wbuffer, "prickly-pear/tedd%03d", i);
+        lfs2_rename(&lfs2, (char*)buffer, (char*)wbuffer) => 0;
+    }
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "prickly-pear") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "tedd%03d", i);
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+        strcmp(info.name, (char*)buffer) => 0;
+        info.type => LFS2_TYPE_REG;
+        info.size => 6;
+    }
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Multi-block remove with files ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_remove(&lfs2, "prickly-pear") => LFS2_ERR_NOTEMPTY;
+
+    for (int i = 0; i < $LARGESIZE; i++) {
+        sprintf((char*)buffer, "prickly-pear/tedd%03d", i);
+        lfs2_remove(&lfs2, (char*)buffer) => 0;
+    }
+
+    lfs2_remove(&lfs2, "prickly-pear") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "burito") => 0;
+    info.type => LFS2_TYPE_REG;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_entries.sh

@@ -0,0 +1,221 @@
+#!/bin/bash
+set -eu
+
+# Note: These tests are intended for 512 byte inline size at different
+# inline sizes they should still pass, but won't be testing anything
+
+echo "=== Entry tests ==="
+rm -rf blocks
+function read_file {
+cat << TEST
+
+    size = $2;
+    lfs2_file_open(&lfs2, &file[0], "$1", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
+    memcmp(rbuffer, wbuffer, size) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+TEST
+}
+
+function write_file {
+cat << TEST
+
+    size = $2;
+    lfs2_file_open(&lfs2, &file[0], "$1",
+            LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC) => 0;
+    memset(wbuffer, 'c', size);
+    lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+TEST
+}
+
+echo "--- Entry grow test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 20)
+    $(write_file "hi1" 20)
+    $(write_file "hi2" 20)
+    $(write_file "hi3" 20)
+
+    $(read_file "hi1" 20)
+    $(write_file "hi1" 200)
+
+    $(read_file "hi0" 20)
+    $(read_file "hi1" 200)
+    $(read_file "hi2" 20)
+    $(read_file "hi3" 20)
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Entry shrink test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 20)
+    $(write_file "hi1" 200)
+    $(write_file "hi2" 20)
+    $(write_file "hi3" 20)
+
+    $(read_file "hi1" 200)
+    $(write_file "hi1" 20)
+
+    $(read_file "hi0" 20)
+    $(read_file "hi1" 20)
+    $(read_file "hi2" 20)
+    $(read_file "hi3" 20)
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Entry spill test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 200)
+    $(write_file "hi1" 200)
+    $(write_file "hi2" 200)
+    $(write_file "hi3" 200)
+
+    $(read_file "hi0" 200)
+    $(read_file "hi1" 200)
+    $(read_file "hi2" 200)
+    $(read_file "hi3" 200)
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Entry push spill test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 200)
+    $(write_file "hi1" 20)
+    $(write_file "hi2" 200)
+    $(write_file "hi3" 200)
+
+    $(read_file "hi1" 20)
+    $(write_file "hi1" 200)
+
+    $(read_file "hi0" 200)
+    $(read_file "hi1" 200)
+    $(read_file "hi2" 200)
+    $(read_file "hi3" 200)
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Entry push spill two test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 200)
+    $(write_file "hi1" 20)
+    $(write_file "hi2" 200)
+    $(write_file "hi3" 200)
+    $(write_file "hi4" 200)
+
+    $(read_file "hi1" 20)
+    $(write_file "hi1" 200)
+
+    $(read_file "hi0" 200)
+    $(read_file "hi1" 200)
+    $(read_file "hi2" 200)
+    $(read_file "hi3" 200)
+    $(read_file "hi4" 200)
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Entry drop test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    $(write_file "hi0" 200)
+    $(write_file "hi1" 200)
+    $(write_file "hi2" 200)
+    $(write_file "hi3" 200)
+
+    lfs2_remove(&lfs2, "hi1") => 0;
+    lfs2_stat(&lfs2, "hi1", &info) => LFS2_ERR_NOENT;
+    $(read_file "hi0" 200)
+    $(read_file "hi2" 200)
+    $(read_file "hi3" 200)
+
+    lfs2_remove(&lfs2, "hi2") => 0;
+    lfs2_stat(&lfs2, "hi2", &info) => LFS2_ERR_NOENT;
+    $(read_file "hi0" 200)
+    $(read_file "hi3" 200)
+
+    lfs2_remove(&lfs2, "hi3") => 0;
+    lfs2_stat(&lfs2, "hi3", &info) => LFS2_ERR_NOENT;
+    $(read_file "hi0" 200)
+
+    lfs2_remove(&lfs2, "hi0") => 0;
+    lfs2_stat(&lfs2, "hi0", &info) => LFS2_ERR_NOENT;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Create too big ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    memset(buffer, 'm', 200);
+    buffer[200] = '\0';
+
+    size = 400;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+            LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC) => 0;
+    memset(wbuffer, 'c', size);
+    lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    size = 400;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer, LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
+    memcmp(rbuffer, wbuffer, size) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Resize too big ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    memset(buffer, 'm', 200);
+    buffer[200] = '\0';
+
+    size = 40;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+            LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC) => 0;
+    memset(wbuffer, 'c', size);
+    lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    size = 40;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer, LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
+    memcmp(rbuffer, wbuffer, size) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    size = 400;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+            LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC) => 0;
+    memset(wbuffer, 'c', size);
+    lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    size = 400;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer, LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
+    memcmp(rbuffer, wbuffer, size) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Results ---"
+tests/stats.py

tests/test_files.sh

@@ -8,61 +8,65 @@ LARGESIZE=262144
 echo "=== File tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 TEST
 
 echo "--- Simple file test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "hello", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
     size = strlen("Hello World!\n");
     memcpy(wbuffer, "Hello World!\n", size);
-    lfs_file_write(&lfs, &file[0], wbuffer, size) => size;
+    lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
 
-    lfs_file_open(&lfs, &file[0], "hello", LFS_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello", LFS2_O_RDONLY) => 0;
     size = strlen("Hello World!\n");
-    lfs_file_read(&lfs, &file[0], rbuffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], rbuffer, size) => size;
     memcmp(rbuffer, wbuffer, size) => 0;
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 w_test() {
-tests/test.py << TEST
+tests/test.py ${4:-} << TEST
-    lfs_size_t size = $1;
+    size = $1;
-    lfs_size_t chunk = 31;
+    lfs2_size_t chunk = 31;
     srand(0);
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$2", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[0], "$2",
-    for (lfs_size_t i = 0; i < size; i += chunk) {
+        ${3:-LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC}) => 0;
+    for (lfs2_size_t i = 0; i < size; i += chunk) {
         chunk = (chunk < size - i) ? chunk : size - i;
-        for (lfs_size_t b = 0; b < chunk; b++) {
+        for (lfs2_size_t b = 0; b < chunk; b++) {
             buffer[b] = rand() & 0xff;
         }
-        lfs_file_write(&lfs, &file[0], buffer, chunk) => chunk;
+        lfs2_file_write(&lfs2, &file[0], buffer, chunk) => chunk;
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
 r_test() {
 tests/test.py << TEST
-    lfs_size_t size = $1;
+    size = $1;
-    lfs_size_t chunk = 29;
+    lfs2_size_t chunk = 29;
     srand(0);
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "$2", LFS_O_RDONLY) => 0;
+    lfs2_stat(&lfs2, "$2", &info) => 0;
-    for (lfs_size_t i = 0; i < size; i += chunk) {
+    info.type => LFS2_TYPE_REG;
+    info.size => size;
+    lfs2_file_open(&lfs2, &file[0], "$2", ${3:-LFS2_O_RDONLY}) => 0;
+    for (lfs2_size_t i = 0; i < size; i += chunk) {
         chunk = (chunk < size - i) ? chunk : size - i;
-        lfs_file_read(&lfs, &file[0], buffer, chunk) => chunk;
+        lfs2_file_read(&lfs2, &file[0], buffer, chunk) => chunk;
-        for (lfs_size_t b = 0; b < chunk && i+b < size; b++) {
+        for (lfs2_size_t b = 0; b < chunk && i+b < size; b++) {
             buffer[b] => rand() & 0xff;
         }
     }
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 }
 
@@ -78,36 +82,76 @@ echo "--- Large file test ---"
 w_test $LARGESIZE largeavacado
 r_test $LARGESIZE largeavacado
 
+echo "--- Zero file test ---"
+w_test 0 noavacado
+r_test 0 noavacado
+
+echo "--- Truncate small test ---"
+w_test $SMALLSIZE mediumavacado
+r_test $SMALLSIZE mediumavacado
+w_test $MEDIUMSIZE mediumavacado
+r_test $MEDIUMSIZE mediumavacado
+
+echo "--- Truncate zero test ---"
+w_test $SMALLSIZE noavacado
+r_test $SMALLSIZE noavacado
+w_test 0 noavacado
+r_test 0 noavacado
+
 echo "--- Non-overlap check ---"
 r_test $SMALLSIZE smallavacado
 r_test $MEDIUMSIZE mediumavacado
 r_test $LARGESIZE largeavacado
+r_test 0 noavacado
 
 echo "--- Dir check ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "hello") => 0;
-    info.type => LFS_TYPE_REG;
+    info.type => LFS2_TYPE_REG;
     info.size => strlen("Hello World!\n");
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    strcmp(info.name, "smallavacado") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => $SMALLSIZE;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "mediumavacado") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => $MEDIUMSIZE;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
     strcmp(info.name, "largeavacado") => 0;
-    info.type => LFS_TYPE_REG;
+    info.type => LFS2_TYPE_REG;
     info.size => $LARGESIZE;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    strcmp(info.name, "mediumavacado") => 0;
-    lfs_unmount(&lfs) => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => $MEDIUMSIZE;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "noavacado") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "smallavacado") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => $SMALLSIZE;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Many file test ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+TEST
+tests/test.py << TEST
+    // Create 300 files of 6 bytes
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "directory") => 0;
+    for (unsigned i = 0; i < 300; i++) {
+        snprintf((char*)buffer, sizeof(buffer), "file_%03d", i);
+        lfs2_file_open(&lfs2, &file[0], (char*)buffer, LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+        size = 6;
+        memcpy(wbuffer, "Hello", size);
+        lfs2_file_write(&lfs2, &file[0], wbuffer, size) => size;
+        lfs2_file_close(&lfs2, &file[0]) => 0;
+    }
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_format.sh

@@ -6,43 +6,44 @@ rm -rf blocks
 
 echo "--- Basic formatting ---"
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
+TEST
+
+echo "--- Basic mounting ---"
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Invalid superblocks ---"
 ln -f -s /dev/zero blocks/0
 ln -f -s /dev/zero blocks/1
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => LFS_ERR_CORRUPT;
+    lfs2_format(&lfs2, &cfg) => LFS2_ERR_NOSPC;
 TEST
 rm blocks/0 blocks/1
 
-echo "--- Basic mounting ---"
-tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
-TEST
-tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_unmount(&lfs) => 0;
-TEST
-
 echo "--- Invalid mount ---"
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => LFS2_ERR_CORRUPT;
-TEST
-rm blocks/0 blocks/1
-tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
 TEST
 
-echo "--- Valid corrupt mount ---"
+echo "--- Expanding superblock ---"
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
+    for (int i = 0; i < 100; i++) {
+        lfs2_mkdir(&lfs2, "dummy") => 0;
+        lfs2_remove(&lfs2, "dummy") => 0;
+    }
+    lfs2_unmount(&lfs2) => 0;
 TEST
-rm blocks/0
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_mkdir(&lfs2, "dummy") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_interspersed.sh

@@ -0,0 +1,186 @@
+#!/bin/bash
+set -eu
+
+echo "=== Interspersed tests ==="
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+TEST
+
+echo "--- Interspersed file test ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_file_open(&lfs2, &file[0], "a", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[1], "b", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[2], "c", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[3], "d", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+
+    for (int i = 0; i < 10; i++) {
+        lfs2_file_write(&lfs2, &file[0], (const void*)"a", 1) => 1;
+        lfs2_file_write(&lfs2, &file[1], (const void*)"b", 1) => 1;
+        lfs2_file_write(&lfs2, &file[2], (const void*)"c", 1) => 1;
+        lfs2_file_write(&lfs2, &file[3], (const void*)"d", 1) => 1;
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_file_close(&lfs2, &file[1]);
+    lfs2_file_close(&lfs2, &file[2]);
+    lfs2_file_close(&lfs2, &file[3]);
+
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "a") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "b") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "c") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "d") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "a", LFS2_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[1], "b", LFS2_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[2], "c", LFS2_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[3], "d", LFS2_O_RDONLY) => 0;
+
+    for (int i = 0; i < 10; i++) {
+        lfs2_file_read(&lfs2, &file[0], buffer, 1) => 1;
+        buffer[0] => 'a';
+        lfs2_file_read(&lfs2, &file[1], buffer, 1) => 1;
+        buffer[0] => 'b';
+        lfs2_file_read(&lfs2, &file[2], buffer, 1) => 1;
+        buffer[0] => 'c';
+        lfs2_file_read(&lfs2, &file[3], buffer, 1) => 1;
+        buffer[0] => 'd';
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_file_close(&lfs2, &file[1]);
+    lfs2_file_close(&lfs2, &file[2]);
+    lfs2_file_close(&lfs2, &file[3]);
+    
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Interspersed remove file test ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_file_open(&lfs2, &file[0], "e", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+
+    for (int i = 0; i < 5; i++) {
+        lfs2_file_write(&lfs2, &file[0], (const void*)"e", 1) => 1;
+    }
+
+    lfs2_remove(&lfs2, "a") => 0;
+    lfs2_remove(&lfs2, "b") => 0;
+    lfs2_remove(&lfs2, "c") => 0;
+    lfs2_remove(&lfs2, "d") => 0;
+
+    for (int i = 0; i < 5; i++) {
+        lfs2_file_write(&lfs2, &file[0], (const void*)"e", 1) => 1;
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "e") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "e", LFS2_O_RDONLY) => 0;
+
+    for (int i = 0; i < 10; i++) {
+        lfs2_file_read(&lfs2, &file[0], buffer, 1) => 1;
+        buffer[0] => 'e';
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+    
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Remove inconveniently test ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_file_open(&lfs2, &file[0], "e", LFS2_O_WRONLY | LFS2_O_TRUNC) => 0;
+    lfs2_file_open(&lfs2, &file[1], "f", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+    lfs2_file_open(&lfs2, &file[2], "g", LFS2_O_WRONLY | LFS2_O_CREAT) => 0;
+
+    for (int i = 0; i < 5; i++) {
+        lfs2_file_write(&lfs2, &file[0], (const void*)"e", 1) => 1;
+        lfs2_file_write(&lfs2, &file[1], (const void*)"f", 1) => 1;
+        lfs2_file_write(&lfs2, &file[2], (const void*)"g", 1) => 1;
+    }
+
+    lfs2_remove(&lfs2, "f") => 0;
+
+    for (int i = 0; i < 5; i++) {
+        lfs2_file_write(&lfs2, &file[0], (const void*)"e", 1) => 1;
+        lfs2_file_write(&lfs2, &file[1], (const void*)"f", 1) => 1;
+        lfs2_file_write(&lfs2, &file[2], (const void*)"g", 1) => 1;
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_file_close(&lfs2, &file[1]);
+    lfs2_file_close(&lfs2, &file[2]);
+
+    lfs2_dir_open(&lfs2, &dir[0], "/") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    info.type => LFS2_TYPE_DIR;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "e") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "g") => 0;
+    info.type => LFS2_TYPE_REG;
+    info.size => 10;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "e", LFS2_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[1], "g", LFS2_O_RDONLY) => 0;
+
+    for (int i = 0; i < 10; i++) {
+        lfs2_file_read(&lfs2, &file[0], buffer, 1) => 1;
+        buffer[0] => 'e';
+        lfs2_file_read(&lfs2, &file[1], buffer, 1) => 1;
+        buffer[0] => 'g';
+    }
+
+    lfs2_file_close(&lfs2, &file[0]);
+    lfs2_file_close(&lfs2, &file[1]);
+    
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Results ---"
+tests/stats.py

tests/test_move.sh

@@ -0,0 +1,332 @@
+#!/bin/bash
+set -eu
+
+echo "=== Move tests ==="
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "a") => 0;
+    lfs2_mkdir(&lfs2, "b") => 0;
+    lfs2_mkdir(&lfs2, "c") => 0;
+    lfs2_mkdir(&lfs2, "d") => 0;
+
+    lfs2_mkdir(&lfs2, "a/hi") => 0;
+    lfs2_mkdir(&lfs2, "a/hi/hola") => 0;
+    lfs2_mkdir(&lfs2, "a/hi/bonjour") => 0;
+    lfs2_mkdir(&lfs2, "a/hi/ohayo") => 0;
+
+    lfs2_file_open(&lfs2, &file[0], "a/hello", LFS2_O_CREAT | LFS2_O_WRONLY) => 0;
+    lfs2_file_write(&lfs2, &file[0], "hola\n", 5) => 5;
+    lfs2_file_write(&lfs2, &file[0], "bonjour\n", 8) => 8;
+    lfs2_file_write(&lfs2, &file[0], "ohayo\n", 6) => 6;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move file ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "a/hello", "b/hello") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "a") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move file corrupt source ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "b/hello", "c/hello") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/corrupt.py -n 1
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move file corrupt source and dest ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "c/hello", "d/hello") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/corrupt.py -n 2
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "d") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move file after corrupt ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "c/hello", "d/hello") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "d") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move dir ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "a/hi", "b/hi") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "a") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move dir corrupt source ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "b/hi", "c/hi") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/corrupt.py -n 1
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move dir corrupt source and dest ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "c/hi", "d/hi") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/corrupt.py -n 2
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "d") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move dir after corrupt ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_rename(&lfs2, "c/hi", "d/hi") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "d") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hello") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move check ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    lfs2_dir_open(&lfs2, &dir[0], "a/hi") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "b/hi") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "c/hi") => LFS2_ERR_NOENT;
+
+    lfs2_dir_open(&lfs2, &dir[0], "d/hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "bonjour") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hola") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "ohayo") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+
+    lfs2_dir_open(&lfs2, &dir[0], "a/hello") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "b/hello") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "c/hello") => LFS2_ERR_NOENT;
+
+    lfs2_file_open(&lfs2, &file[0], "d/hello", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 5) => 5;
+    memcmp(buffer, "hola\n", 5) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 8) => 8;
+    memcmp(buffer, "bonjour\n", 8) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 6) => 6;
+    memcmp(buffer, "ohayo\n", 6) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Move state stealing ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    lfs2_remove(&lfs2, "b") => 0;
+    lfs2_remove(&lfs2, "c") => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    lfs2_dir_open(&lfs2, &dir[0], "a/hi") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => LFS2_ERR_NOENT;
+
+    lfs2_dir_open(&lfs2, &dir[0], "d/hi") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, ".") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "..") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "bonjour") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "hola") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
+    strcmp(info.name, "ohayo") => 0;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
+
+    lfs2_dir_open(&lfs2, &dir[0], "a/hello") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "b") => LFS2_ERR_NOENT;
+    lfs2_dir_open(&lfs2, &dir[0], "c") => LFS2_ERR_NOENT;
+
+    lfs2_file_open(&lfs2, &file[0], "d/hello", LFS2_O_RDONLY) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 5) => 5;
+    memcmp(buffer, "hola\n", 5) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 8) => 8;
+    memcmp(buffer, "bonjour\n", 8) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, 6) => 6;
+    memcmp(buffer, "ohayo\n", 6) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+
+echo "--- Results ---"
+tests/stats.py

tests/test_orphan.sh

@@ -4,37 +4,41 @@ set -eu
 echo "=== Orphan tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 TEST
 
 echo "--- Orphan test ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "parent") => 0;
+    lfs2_mkdir(&lfs2, "parent") => 0;
-    lfs_mkdir(&lfs, "parent/orphan") => 0;
+    lfs2_mkdir(&lfs2, "parent/orphan") => 0;
-    lfs_mkdir(&lfs, "parent/child") => 0;
+    lfs2_mkdir(&lfs2, "parent/child") => 0;
-    lfs_remove(&lfs, "parent/orphan") => 0;
+    lfs2_remove(&lfs2, "parent/orphan") => 0;
 TEST
-# remove most recent file, this should be the update to the previous
+# corrupt most recent commit, this should be the update to the previous
 # linked-list entry and should orphan the child
-rm -v blocks/8
+tests/corrupt.py
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
-    unsigned before = 0;
-    lfs_traverse(&lfs, test_count, &before) => 0;
-    test_log("before", before);
 
-    lfs_deorphan(&lfs) => 0;
+    lfs2_stat(&lfs2, "parent/orphan", &info) => LFS2_ERR_NOENT;
+    lfs2_ssize_t before = lfs2_fs_size(&lfs2);
+    before => 8;
 
-    lfs_stat(&lfs, "parent/orphan", &info) => LFS_ERR_NOENT;
+    lfs2_unmount(&lfs2) => 0;
-    unsigned after = 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_traverse(&lfs, test_count, &after) => 0;
-    test_log("after", after);
 
-    int diff = before - after;
+    lfs2_stat(&lfs2, "parent/orphan", &info) => LFS2_ERR_NOENT;
-    diff => 2;
+    lfs2_ssize_t orphaned = lfs2_fs_size(&lfs2);
-    lfs_unmount(&lfs) => 0;
+    orphaned => 8;
+
+    lfs2_mkdir(&lfs2, "parent/otherchild") => 0;
+
+    lfs2_stat(&lfs2, "parent/orphan", &info) => LFS2_ERR_NOENT;
+    lfs2_ssize_t deorphaned = lfs2_fs_size(&lfs2);
+    deorphaned => 8;
+
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_parallel.sh

@@ -1,186 +0,0 @@
-#!/bin/bash
-set -eu
-
-echo "=== Parallel tests ==="
-rm -rf blocks
-tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
-TEST
-
-echo "--- Parallel file test ---"
-tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "a", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    lfs_file_open(&lfs, &file[1], "b", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    lfs_file_open(&lfs, &file[2], "c", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    lfs_file_open(&lfs, &file[3], "d", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-
-    for (int i = 0; i < 10; i++) {
-        lfs_file_write(&lfs, &file[0], (const void*)"a", 1) => 1;
-        lfs_file_write(&lfs, &file[1], (const void*)"b", 1) => 1;
-        lfs_file_write(&lfs, &file[2], (const void*)"c", 1) => 1;
-        lfs_file_write(&lfs, &file[3], (const void*)"d", 1) => 1;
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-    lfs_file_close(&lfs, &file[1]);
-    lfs_file_close(&lfs, &file[2]);
-    lfs_file_close(&lfs, &file[3]);
-
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "a") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "b") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "c") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "d") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
-
-    lfs_file_open(&lfs, &file[0], "a", LFS_O_RDONLY) => 0;
-    lfs_file_open(&lfs, &file[1], "b", LFS_O_RDONLY) => 0;
-    lfs_file_open(&lfs, &file[2], "c", LFS_O_RDONLY) => 0;
-    lfs_file_open(&lfs, &file[3], "d", LFS_O_RDONLY) => 0;
-
-    for (int i = 0; i < 10; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, 1) => 1;
-        buffer[0] => 'a';
-        lfs_file_read(&lfs, &file[1], buffer, 1) => 1;
-        buffer[0] => 'b';
-        lfs_file_read(&lfs, &file[2], buffer, 1) => 1;
-        buffer[0] => 'c';
-        lfs_file_read(&lfs, &file[3], buffer, 1) => 1;
-        buffer[0] => 'd';
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-    lfs_file_close(&lfs, &file[1]);
-    lfs_file_close(&lfs, &file[2]);
-    lfs_file_close(&lfs, &file[3]);
-    
-    lfs_unmount(&lfs) => 0;
-TEST
-
-echo "--- Parallel remove file test ---"
-tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "e", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-
-    for (int i = 0; i < 5; i++) {
-        lfs_file_write(&lfs, &file[0], (const void*)"e", 1) => 1;
-    }
-
-    lfs_remove(&lfs, "a") => 0;
-    lfs_remove(&lfs, "b") => 0;
-    lfs_remove(&lfs, "c") => 0;
-    lfs_remove(&lfs, "d") => 0;
-
-    for (int i = 0; i < 5; i++) {
-        lfs_file_write(&lfs, &file[0], (const void*)"e", 1) => 1;
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "e") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
-
-    lfs_file_open(&lfs, &file[0], "e", LFS_O_RDONLY) => 0;
-
-    for (int i = 0; i < 10; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, 1) => 1;
-        buffer[0] => 'e';
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-    
-    lfs_unmount(&lfs) => 0;
-TEST
-
-echo "--- Remove inconveniently test ---"
-tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "e", LFS_O_WRONLY | LFS_O_TRUNC) => 0;
-    lfs_file_open(&lfs, &file[1], "f", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-    lfs_file_open(&lfs, &file[2], "g", LFS_O_WRONLY | LFS_O_CREAT) => 0;
-
-    for (int i = 0; i < 5; i++) {
-        lfs_file_write(&lfs, &file[0], (const void*)"e", 1) => 1;
-        lfs_file_write(&lfs, &file[1], (const void*)"f", 1) => 1;
-        lfs_file_write(&lfs, &file[2], (const void*)"g", 1) => 1;
-    }
-
-    lfs_remove(&lfs, "f") => 0;
-
-    for (int i = 0; i < 5; i++) {
-        lfs_file_write(&lfs, &file[0], (const void*)"e", 1) => 1;
-        lfs_file_write(&lfs, &file[1], (const void*)"f", 1) => 1;
-        lfs_file_write(&lfs, &file[2], (const void*)"g", 1) => 1;
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-    lfs_file_close(&lfs, &file[1]);
-    lfs_file_close(&lfs, &file[2]);
-
-    lfs_dir_open(&lfs, &dir[0], "/") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, ".") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "..") => 0;
-    info.type => LFS_TYPE_DIR;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "e") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
-    strcmp(info.name, "g") => 0;
-    info.type => LFS_TYPE_REG;
-    info.size => 10;
-    lfs_dir_read(&lfs, &dir[0], &info) => 0;
-    lfs_dir_close(&lfs, &dir[0]) => 0;
-
-    lfs_file_open(&lfs, &file[0], "e", LFS_O_RDONLY) => 0;
-    lfs_file_open(&lfs, &file[1], "g", LFS_O_RDONLY) => 0;
-
-    for (int i = 0; i < 10; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, 1) => 1;
-        buffer[0] => 'e';
-        lfs_file_read(&lfs, &file[1], buffer, 1) => 1;
-        buffer[0] => 'g';
-    }
-
-    lfs_file_close(&lfs, &file[0]);
-    lfs_file_close(&lfs, &file[1]);
-    
-    lfs_unmount(&lfs) => 0;
-TEST
-
-echo "--- Results ---"
-tests/stats.py

tests/test_paths.sh

@@ -4,82 +4,165 @@ set -eu
 echo "=== Path tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
 TEST
 
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "tea") => 0;
+    lfs2_mkdir(&lfs2, "tea") => 0;
-    lfs_mkdir(&lfs, "coffee") => 0;
+    lfs2_mkdir(&lfs2, "coffee") => 0;
-    lfs_mkdir(&lfs, "soda") => 0;
+    lfs2_mkdir(&lfs2, "soda") => 0;
-    lfs_mkdir(&lfs, "tea/hottea") => 0;
+    lfs2_mkdir(&lfs2, "tea/hottea") => 0;
-    lfs_mkdir(&lfs, "tea/warmtea") => 0;
+    lfs2_mkdir(&lfs2, "tea/warmtea") => 0;
-    lfs_mkdir(&lfs, "tea/coldtea") => 0;
+    lfs2_mkdir(&lfs2, "tea/coldtea") => 0;
-    lfs_mkdir(&lfs, "coffee/hotcoffee") => 0;
+    lfs2_mkdir(&lfs2, "coffee/hotcoffee") => 0;
-    lfs_mkdir(&lfs, "coffee/warmcoffee") => 0;
+    lfs2_mkdir(&lfs2, "coffee/warmcoffee") => 0;
-    lfs_mkdir(&lfs, "coffee/coldcoffee") => 0;
+    lfs2_mkdir(&lfs2, "coffee/coldcoffee") => 0;
-    lfs_mkdir(&lfs, "soda/hotsoda") => 0;
+    lfs2_mkdir(&lfs2, "soda/hotsoda") => 0;
-    lfs_mkdir(&lfs, "soda/warmsoda") => 0;
+    lfs2_mkdir(&lfs2, "soda/warmsoda") => 0;
-    lfs_mkdir(&lfs, "soda/coldsoda") => 0;
+    lfs2_mkdir(&lfs2, "soda/coldsoda") => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Root path tests ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "/tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "/tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_unmount(&lfs) => 0;
+
+    lfs2_mkdir(&lfs2, "/milk1") => 0;
+    lfs2_stat(&lfs2, "/milk1", &info) => 0;
+    strcmp(info.name, "milk1") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Redundant slash path tests ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "/tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "/tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "//tea//hottea", &info) => 0;
+    lfs2_stat(&lfs2, "//tea//hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "///tea///hottea", &info) => 0;
+    lfs2_stat(&lfs2, "///tea///hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_unmount(&lfs) => 0;
+
+    lfs2_mkdir(&lfs2, "///milk2") => 0;
+    lfs2_stat(&lfs2, "///milk2", &info) => 0;
+    strcmp(info.name, "milk2") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Dot path tests ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "./tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "./tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "/./tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "/./tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "/././tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "/././tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "/./tea/./hottea", &info) => 0;
+    lfs2_stat(&lfs2, "/./tea/./hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_unmount(&lfs) => 0;
+
+    lfs2_mkdir(&lfs2, "/./milk3") => 0;
+    lfs2_stat(&lfs2, "/./milk3", &info) => 0;
+    strcmp(info.name, "milk3") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Dot dot path tests ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "coffee/../tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "coffee/../tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "tea/coldtea/../hottea", &info) => 0;
+    lfs2_stat(&lfs2, "tea/coldtea/../hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "coffee/coldcoffee/../../tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "coffee/coldcoffee/../../tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_stat(&lfs, "coffee/../soda/../tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "coffee/../soda/../tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_unmount(&lfs) => 0;
+
+    lfs2_mkdir(&lfs2, "coffee/../milk4") => 0;
+    lfs2_stat(&lfs2, "coffee/../milk4", &info) => 0;
+    strcmp(info.name, "milk4") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Trailing dot path tests ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_stat(&lfs2, "tea/hottea/", &info) => 0;
+    strcmp(info.name, "hottea") => 0;
+    lfs2_stat(&lfs2, "tea/hottea/.", &info) => 0;
+    strcmp(info.name, "hottea") => 0;
+    lfs2_stat(&lfs2, "tea/hottea/./.", &info) => 0;
+    strcmp(info.name, "hottea") => 0;
+    lfs2_stat(&lfs2, "tea/hottea/..", &info) => 0;
+    strcmp(info.name, "tea") => 0;
+    lfs2_stat(&lfs2, "tea/hottea/../.", &info) => 0;
+    strcmp(info.name, "tea") => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Root dot dot path tests ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_stat(&lfs, "coffee/../../../../../../tea/hottea", &info) => 0;
+    lfs2_stat(&lfs2, "coffee/../../../../../../tea/hottea", &info) => 0;
     strcmp(info.name, "hottea") => 0;
-    lfs_unmount(&lfs) => 0;
+
+    lfs2_mkdir(&lfs2, "coffee/../../../../../../milk5") => 0;
+    lfs2_stat(&lfs2, "coffee/../../../../../../milk5", &info) => 0;
+    strcmp(info.name, "milk5") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Root tests ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_stat(&lfs2, "/", &info) => 0;
+    info.type => LFS2_TYPE_DIR;
+    strcmp(info.name, "/") => 0;
+
+    lfs2_mkdir(&lfs2, "/") => LFS2_ERR_EXIST;
+    lfs2_file_open(&lfs2, &file[0], "/", LFS2_O_WRONLY | LFS2_O_CREAT)
+        => LFS2_ERR_ISDIR;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Sketchy path tests ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "dirt/ground") => LFS2_ERR_NOENT;
+    lfs2_mkdir(&lfs2, "dirt/ground/earth") => LFS2_ERR_NOENT;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Superblock conflict test ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_mkdir(&lfs2, "littlefs") => 0;
+    lfs2_remove(&lfs2, "littlefs") => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Max path test ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    memset(buffer, 'w', LFS2_NAME_MAX+1);
+    buffer[LFS2_NAME_MAX+2] = '\0';
+    lfs2_mkdir(&lfs2, (char*)buffer) => LFS2_ERR_NAMETOOLONG;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+            LFS2_O_WRONLY | LFS2_O_CREAT) => LFS2_ERR_NAMETOOLONG;
+
+    memcpy(buffer, "coffee/", strlen("coffee/"));
+    memset(buffer+strlen("coffee/"), 'w', LFS2_NAME_MAX+1);
+    buffer[strlen("coffee/")+LFS2_NAME_MAX+2] = '\0';
+    lfs2_mkdir(&lfs2, (char*)buffer) => LFS2_ERR_NAMETOOLONG;
+    lfs2_file_open(&lfs2, &file[0], (char*)buffer,
+            LFS2_O_WRONLY | LFS2_O_CREAT) => LFS2_ERR_NAMETOOLONG;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_seek.sh

@@ -8,273 +8,353 @@ LARGESIZE=132
 echo "=== Seek tests ==="
 rm -rf blocks
 tests/test.py << TEST
-    lfs_format(&lfs, &cfg) => 0;
+    lfs2_format(&lfs2, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_mkdir(&lfs, "hello") => 0;
+    lfs2_mkdir(&lfs2, "hello") => 0;
     for (int i = 0; i < $LARGESIZE; i++) {
-        sprintf((char*)buffer, "hello/kitty%d", i);
+        sprintf((char*)buffer, "hello/kitty%03d", i);
-        lfs_file_open(&lfs, &file[0], (char*)buffer,
+        lfs2_file_open(&lfs2, &file[0], (char*)buffer,
-                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_APPEND) => 0;
+                LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_APPEND) => 0;
 
         size = strlen("kittycatcat");
         memcpy(buffer, "kittycatcat", size);
         for (int j = 0; j < $LARGESIZE; j++) {
-            lfs_file_write(&lfs, &file[0], buffer, size);
+            lfs2_file_write(&lfs2, &file[0], buffer, size);
         }
 
-        lfs_file_close(&lfs, &file[0]) => 0;
+        lfs2_file_close(&lfs2, &file[0]) => 0;
     }
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Simple dir seek ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "hello") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "hello") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     int i;
     for (i = 0; i < $SMALLSIZE; i++) {
-        sprintf((char*)buffer, "kitty%d", i);
+        sprintf((char*)buffer, "kitty%03d", i);
-        lfs_dir_read(&lfs, &dir[0], &info) => 1;
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
         strcmp(info.name, (char*)buffer) => 0;
-        pos = lfs_dir_tell(&lfs, &dir[0]);
+        pos = lfs2_dir_tell(&lfs2, &dir[0]);
     }
     pos >= 0 => 1;
 
-    lfs_dir_seek(&lfs, &dir[0], pos) => 0;
+    lfs2_dir_seek(&lfs2, &dir[0], pos) => 0;
-    sprintf((char*)buffer, "kitty%d", i);
+    sprintf((char*)buffer, "kitty%03d", i);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_rewind(&lfs, &dir[0]) => 0;
+    lfs2_dir_rewind(&lfs2, &dir[0]) => 0;
-    sprintf((char*)buffer, "kitty%d", 0);
+    sprintf((char*)buffer, "kitty%03d", 0);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_seek(&lfs, &dir[0], pos) => 0;
+    lfs2_dir_seek(&lfs2, &dir[0], pos) => 0;
-    sprintf((char*)buffer, "kitty%d", i);
+    sprintf((char*)buffer, "kitty%03d", i);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Large dir seek ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_dir_open(&lfs, &dir[0], "hello") => 0;
+    lfs2_dir_open(&lfs2, &dir[0], "hello") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     int i;
     for (i = 0; i < $MEDIUMSIZE; i++) {
-        sprintf((char*)buffer, "kitty%d", i);
+        sprintf((char*)buffer, "kitty%03d", i);
-        lfs_dir_read(&lfs, &dir[0], &info) => 1;
+        lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
         strcmp(info.name, (char*)buffer) => 0;
-        pos = lfs_dir_tell(&lfs, &dir[0]);
+        pos = lfs2_dir_tell(&lfs2, &dir[0]);
     }
     pos >= 0 => 1;
 
-    lfs_dir_seek(&lfs, &dir[0], pos) => 0;
+    lfs2_dir_seek(&lfs2, &dir[0], pos) => 0;
-    sprintf((char*)buffer, "kitty%d", i);
+    sprintf((char*)buffer, "kitty%03d", i);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_rewind(&lfs, &dir[0]) => 0;
+    lfs2_dir_rewind(&lfs2, &dir[0]) => 0;
-    sprintf((char*)buffer, "kitty%d", 0);
+    sprintf((char*)buffer, "kitty%03d", 0);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, ".") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, "..") => 0;
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_seek(&lfs, &dir[0], pos) => 0;
+    lfs2_dir_seek(&lfs2, &dir[0], pos) => 0;
-    sprintf((char*)buffer, "kitty%d", i);
+    sprintf((char*)buffer, "kitty%03d", i);
-    lfs_dir_read(&lfs, &dir[0], &info) => 1;
+    lfs2_dir_read(&lfs2, &dir[0], &info) => 1;
     strcmp(info.name, (char*)buffer) => 0;
 
-    lfs_dir_close(&lfs, &dir[0]) => 0;
+    lfs2_dir_close(&lfs2, &dir[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Simple file seek ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "hello/kitty42", LFS_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDONLY) => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     size = strlen("kittycatcat");
     for (int i = 0; i < $SMALLSIZE; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
         memcmp(buffer, "kittycatcat", size) => 0;
-        pos = lfs_file_tell(&lfs, &file[0]);
+        pos = lfs2_file_tell(&lfs2, &file[0]);
     }
     pos >= 0 => 1;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_rewind(&lfs, &file[0]) => 0;
+    lfs2_file_rewind(&lfs2, &file[0]) => 0;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => size;
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_CUR) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], size, LFS2_SEEK_CUR) => 3*size;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_END) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_size_t size = lfs_file_size(&lfs, &file[0]);
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_CUR) => pos;
-    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_END) >= 0 => 1;
-    lfs_unmount(&lfs) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
+    size = lfs2_file_size(&lfs2, &file[0]);
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Large file seek ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "hello/kitty42", LFS_O_RDONLY) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDONLY) => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     size = strlen("kittycatcat");
     for (int i = 0; i < $MEDIUMSIZE; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
         memcmp(buffer, "kittycatcat", size) => 0;
-        pos = lfs_file_tell(&lfs, &file[0]);
+        pos = lfs2_file_tell(&lfs2, &file[0]);
     }
     pos >= 0 => 1;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_rewind(&lfs, &file[0]) => 0;
+    lfs2_file_rewind(&lfs2, &file[0]) => 0;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => size;
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_CUR) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], size, LFS2_SEEK_CUR) => 3*size;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_END) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_size_t size = lfs_file_size(&lfs, &file[0]);
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_CUR) => pos;
-    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_END) >= 0 => 1;
-    lfs_unmount(&lfs) => 0;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "kittycatcat", size) => 0;
+
+    size = lfs2_file_size(&lfs2, &file[0]);
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Simple file seek and write ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "hello/kitty42", LFS_O_RDWR) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDWR) => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     size = strlen("kittycatcat");
     for (int i = 0; i < $SMALLSIZE; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
         memcmp(buffer, "kittycatcat", size) => 0;
-        pos = lfs_file_tell(&lfs, &file[0]);
+        pos = lfs2_file_tell(&lfs2, &file[0]);
     }
     pos >= 0 => 1;
 
     memcpy(buffer, "doggodogdog", size);
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "doggodogdog", size) => 0;
 
-    lfs_file_rewind(&lfs, &file[0]) => 0;
+    lfs2_file_rewind(&lfs2, &file[0]) => 0;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "doggodogdog", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_END) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_END) >= 0 => 1;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_size_t size = lfs_file_size(&lfs, &file[0]);
+    size = lfs2_file_size(&lfs2, &file[0]);
-    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Large file seek and write ---"
 tests/test.py << TEST
-    lfs_mount(&lfs, &cfg) => 0;
+    lfs2_mount(&lfs2, &cfg) => 0;
-    lfs_file_open(&lfs, &file[0], "hello/kitty42", LFS_O_RDWR) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDWR) => 0;
 
-    lfs_soff_t pos;
+    lfs2_soff_t pos;
     size = strlen("kittycatcat");
     for (int i = 0; i < $MEDIUMSIZE; i++) {
-        lfs_file_read(&lfs, &file[0], buffer, size) => size;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
         if (i != $SMALLSIZE) {
             memcmp(buffer, "kittycatcat", size) => 0;
         }
-        pos = lfs_file_tell(&lfs, &file[0]);
+        pos = lfs2_file_tell(&lfs2, &file[0]);
     }
     pos >= 0 => 1;
 
     memcpy(buffer, "doggodogdog", size);
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_write(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "doggodogdog", size) => 0;
 
-    lfs_file_rewind(&lfs, &file[0]) => 0;
+    lfs2_file_rewind(&lfs2, &file[0]) => 0;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], pos, LFS_SEEK_SET) => size;
+    lfs2_file_seek(&lfs2, &file[0], pos, LFS2_SEEK_SET) => pos;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "doggodogdog", size) => 0;
 
-    lfs_file_seek(&lfs, &file[0], -size, LFS_SEEK_END) => pos+size;
+    lfs2_file_seek(&lfs2, &file[0], -size, LFS2_SEEK_END) >= 0 => 1;
-    lfs_file_read(&lfs, &file[0], buffer, size) => size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
     memcmp(buffer, "kittycatcat", size) => 0;
 
-    lfs_size_t size = lfs_file_size(&lfs, &file[0]);
+    size = lfs2_file_size(&lfs2, &file[0]);
-    lfs_file_seek(&lfs, &file[0], 0, LFS_SEEK_CUR) => size;
+    lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_CUR) => size;
 
-    lfs_file_close(&lfs, &file[0]) => 0;
+    lfs2_file_close(&lfs2, &file[0]) => 0;
-    lfs_unmount(&lfs) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Boundary seek and write ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDWR) => 0;
+
+    size = strlen("hedgehoghog");
+    const lfs2_soff_t offsets[] = {512, 1020, 513, 1021, 511, 1019};
+
+    for (unsigned i = 0; i < sizeof(offsets) / sizeof(offsets[0]); i++) {
+        lfs2_soff_t off = offsets[i];
+        memcpy(buffer, "hedgehoghog", size);
+        lfs2_file_seek(&lfs2, &file[0], off, LFS2_SEEK_SET) => off;
+        lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+        lfs2_file_seek(&lfs2, &file[0], off, LFS2_SEEK_SET) => off;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+        memcmp(buffer, "hedgehoghog", size) => 0;
+
+        lfs2_file_seek(&lfs2, &file[0], 0, LFS2_SEEK_SET) => 0;
+        lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+        memcmp(buffer, "kittycatcat", size) => 0;
+
+        lfs2_file_sync(&lfs2, &file[0]) => 0;
+    }
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
+TEST
+
+echo "--- Out-of-bounds seek ---"
+tests/test.py << TEST
+    lfs2_mount(&lfs2, &cfg) => 0;
+    lfs2_file_open(&lfs2, &file[0], "hello/kitty042", LFS2_O_RDWR) => 0;
+
+    size = strlen("kittycatcat");
+    lfs2_file_size(&lfs2, &file[0]) => $LARGESIZE*size;
+    lfs2_file_seek(&lfs2, &file[0], ($LARGESIZE+$SMALLSIZE)*size,
+            LFS2_SEEK_SET) => ($LARGESIZE+$SMALLSIZE)*size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => 0;
+
+    memcpy(buffer, "porcupineee", size);
+    lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+
+    lfs2_file_seek(&lfs2, &file[0], ($LARGESIZE+$SMALLSIZE)*size,
+            LFS2_SEEK_SET) => ($LARGESIZE+$SMALLSIZE)*size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "porcupineee", size) => 0;
+
+    lfs2_file_seek(&lfs2, &file[0], $LARGESIZE*size,
+            LFS2_SEEK_SET) => $LARGESIZE*size;
+    lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+    memcmp(buffer, "\0\0\0\0\0\0\0\0\0\0\0", size) => 0;
+
+    lfs2_file_seek(&lfs2, &file[0], -(($LARGESIZE+$SMALLSIZE)*size),
+            LFS2_SEEK_CUR) => LFS2_ERR_INVAL;
+    lfs2_file_tell(&lfs2, &file[0]) => ($LARGESIZE+1)*size;
+
+    lfs2_file_seek(&lfs2, &file[0], -(($LARGESIZE+2*$SMALLSIZE)*size),
+            LFS2_SEEK_END) => LFS2_ERR_INVAL;
+    lfs2_file_tell(&lfs2, &file[0]) => ($LARGESIZE+1)*size;
+
+    lfs2_file_close(&lfs2, &file[0]) => 0;
+    lfs2_unmount(&lfs2) => 0;
 TEST
 
 echo "--- Results ---"

tests/test_truncate.sh

@@ -0,0 +1,158 @@
+#!/bin/bash
+set -eu
+
+SMALLSIZE=32
+MEDIUMSIZE=2048
+LARGESIZE=8192
+
+echo "=== Truncate tests ==="
+rm -rf blocks
+tests/test.py << TEST
+    lfs2_format(&lfs2, &cfg) => 0;
+TEST
+
+truncate_test() {
+STARTSIZES="$1"
+STARTSEEKS="$2"
+HOTSIZES="$3"
+COLDSIZES="$4"
+tests/test.py << TEST
+    static const lfs2_off_t startsizes[] = {$STARTSIZES};
+    static const lfs2_off_t startseeks[] = {$STARTSEEKS};
+    static const lfs2_off_t hotsizes[]   = {$HOTSIZES};
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    for (unsigned i = 0; i < sizeof(startsizes)/sizeof(startsizes[0]); i++) {
+        sprintf((char*)buffer, "hairyhead%d", i);
+        lfs2_file_open(&lfs2, &file[0], (const char*)buffer,
+                LFS2_O_WRONLY | LFS2_O_CREAT | LFS2_O_TRUNC) => 0;
+
+        strcpy((char*)buffer, "hair");
+        size = strlen((char*)buffer);
+        for (lfs2_off_t j = 0; j < startsizes[i]; j += size) {
+            lfs2_file_write(&lfs2, &file[0], buffer, size) => size;
+        }
+        lfs2_file_size(&lfs2, &file[0]) => startsizes[i];
+
+        if (startseeks[i] != startsizes[i]) {
+            lfs2_file_seek(&lfs2, &file[0],
+                    startseeks[i], LFS2_SEEK_SET) => startseeks[i];
+        }
+
+        lfs2_file_truncate(&lfs2, &file[0], hotsizes[i]) => 0;
+        lfs2_file_size(&lfs2, &file[0]) => hotsizes[i];
+
+        lfs2_file_close(&lfs2, &file[0]) => 0;
+    }
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    static const lfs2_off_t startsizes[] = {$STARTSIZES};
+    static const lfs2_off_t hotsizes[]   = {$HOTSIZES};
+    static const lfs2_off_t coldsizes[]  = {$COLDSIZES};
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    for (unsigned i = 0; i < sizeof(startsizes)/sizeof(startsizes[0]); i++) {
+        sprintf((char*)buffer, "hairyhead%d", i);
+        lfs2_file_open(&lfs2, &file[0], (const char*)buffer, LFS2_O_RDWR) => 0;
+        lfs2_file_size(&lfs2, &file[0]) => hotsizes[i];
+
+        size = strlen("hair");
+        lfs2_off_t j = 0;
+        for (; j < startsizes[i] && j < hotsizes[i]; j += size) {
+            lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+            memcmp(buffer, "hair", size) => 0;
+        }
+
+        for (; j < hotsizes[i]; j += size) {
+            lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+            memcmp(buffer, "\0\0\0\0", size) => 0;
+        }
+
+        lfs2_file_truncate(&lfs2, &file[0], coldsizes[i]) => 0;
+        lfs2_file_size(&lfs2, &file[0]) => coldsizes[i];
+
+        lfs2_file_close(&lfs2, &file[0]) => 0;
+    }
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+tests/test.py << TEST
+    static const lfs2_off_t startsizes[] = {$STARTSIZES};
+    static const lfs2_off_t hotsizes[]   = {$HOTSIZES};
+    static const lfs2_off_t coldsizes[]  = {$COLDSIZES};
+
+    lfs2_mount(&lfs2, &cfg) => 0;
+
+    for (unsigned i = 0; i < sizeof(startsizes)/sizeof(startsizes[0]); i++) {
+        sprintf((char*)buffer, "hairyhead%d", i);
+        lfs2_file_open(&lfs2, &file[0], (const char*)buffer, LFS2_O_RDONLY) => 0;
+        lfs2_file_size(&lfs2, &file[0]) => coldsizes[i];
+
+        size = strlen("hair");
+        lfs2_off_t j = 0;
+        for (; j < startsizes[i] && j < hotsizes[i] && j < coldsizes[i];
+                j += size) {
+            lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+            memcmp(buffer, "hair", size) => 0;
+        }
+
+        for (; j < coldsizes[i]; j += size) {
+            lfs2_file_read(&lfs2, &file[0], buffer, size) => size;
+            memcmp(buffer, "\0\0\0\0", size) => 0;
+        }
+
+        lfs2_file_close(&lfs2, &file[0]) => 0;
+    }
+
+    lfs2_unmount(&lfs2) => 0;
+TEST
+}
+
+echo "--- Cold shrinking truncate ---"
+truncate_test \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE"
+
+echo "--- Cold expanding truncate ---"
+truncate_test \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE"
+
+echo "--- Warm shrinking truncate ---"
+truncate_test \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,            0,            0,            0,            0"
+
+echo "--- Warm expanding truncate ---"
+truncate_test \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE"
+
+echo "--- Mid-file shrinking truncate ---"
+truncate_test \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "  $LARGESIZE,   $LARGESIZE,   $LARGESIZE,   $LARGESIZE,   $LARGESIZE" \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,            0,            0,            0,            0"
+
+echo "--- Mid-file expanding truncate ---"
+truncate_test \
+    "           0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE, 2*$LARGESIZE" \
+    "           0,            0,   $SMALLSIZE,  $MEDIUMSIZE,   $LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE" \
+    "2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE, 2*$LARGESIZE"
+
+echo "--- Results ---"
+tests/stats.py