Fixed single unchecked bit during commit verification

This bug was exposed by the bad-block tests due to changes to block
allocation, but could have been hit before these changes.

In flash, when blocks fail, they don't fail in a predictable manner. To
account for this, the bad-block tests check a number of failure
behaviors. The interesting one here is "LFS_TESTBD_BADBLOCK_ERASENOOP",
in which bad blocks can not be erased or programmed, and are stuck with
the data written at the time the blocks go bad.

This is actually a pretty realistic failure behavior, since flash needs a
large voltage to force the electrons of the floating gates. Though
realistically, such a failure would like corrupt the data a bit, not leave the
underlying data perfectly intact.

LFS_TESTBD_BADBLOCK_ERASENOOP is rather interesting to test for because it
means bad blocks can end up with perfectly valid CRCs after a failed write,
confusing littlefs.

---

In this case, we had the perfect series of operations such that a test
was repeatedly writing the same sequence of metadata commits to the same
block, which eventually goes bad, leaving the block stuck with metadata
that occurs later in the sequence.

What this means is that after the first commit, the metadata block
contained both the first and second commits, even though the loop in the
test hadn't reached that point yet.

expected       actual
.----------.  .----------.
| commit 1 |  | commit 1 |
| crc 1    |  | crc 1    |
|          |  | commit 2 <-- (from previous iteration)
|          |  | crc 2    |
'----------'  '----------'

To protect against this, littlefs normally compares the written CRC
against the expected CRC, but because this was the exact same data that
it was going to write, this CRCs end up the same.

Ah! But doesn't littlefs also encode the state of the next page to keep
track of if the next page has been erased or not? Wouldn't that change
between iterations?

It does! In a single bit in the CRC-tag. But thanks to some incorrect
logic attempting to avoid an extra condition in the loop for writing out
padding commits, the CRC that littlefs checked against was the CRC
immediately before we include the "is-next-page-erased" bit.

Changing the verification check to use the same CRC as what is used to
verify commits on fetch solves this problem.

.gitignore

@@ -7,4 +7,6 @@
 blocks/
 lfs
 test.c
-tests_/*.toml.*
+tests/*.toml.*
+scripts/__pycache__
+.gdb_history

.travis.yml

@@ -1,49 +1,70 @@
-# Environment variables
+# environment variables
 env:
   global:
     - CFLAGS=-Werror
+    - MAKEFLAGS=-j
 
-# Common test script
-script:
+# cache installation dirs
+cache:
+  pip: true
+  directories:
+    - $HOME/.cache/apt
+
+# common installation
+_: &install-common
+  # need toml, also pip3 isn't installed by default?
+  - sudo apt-get install python3 python3-pip
+  - sudo pip3 install toml
+  # setup a ram-backed disk to speed up reentrant tests
+  - mkdir disks
+  - sudo mount -t tmpfs -o size=100m tmpfs disks
+  - export TFLAGS="$TFLAGS --disk=disks/disk"
+
+# test cases
+_: &test-example
   # 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 &&
     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"
+# default tests
+_: &test-default
+  # normal+reentrant tests
+  - make test TFLAGS+="-nrk"
+# common real-life geometries
+_: &test-nor
+  # NOR flash: read/prog = 1 block = 4KiB
+  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=1 -DLFS_BLOCK_SIZE=4096"
+_: &test-emmc
+  # eMMC: read/prog = 512 block = 512
+  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=512 -DLFS_BLOCK_SIZE=512"
+_: &test-nand
+  # NAND flash: read/prog = 4KiB block = 32KiB
+  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=4096 -DLFS_BLOCK_SIZE=\(32*1024\)"
+# other extreme geometries that are useful for testing various corner cases
+_: &test-no-intrinsics
+  - make test TFLAGS+="-nrk -DLFS_NO_INTRINSICS"
+_: &test-no-inline
+  - make test TFLAGS+="-nrk -DLFS_INLINE_MAX=0"
+_: &test-byte-writes
+  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=1 -DLFS_CACHE_SIZE=1"
+_: &test-block-cycles
+  - make test TFLAGS+="-nrk -DLFS_BLOCK_CYCLES=1"
+_: &test-odd-block-count
+  - make test TFLAGS+="-nrk -DLFS_BLOCK_COUNT=1023 -DLFS_LOOKAHEAD_SIZE=256"
+_: &test-odd-block-size
+  - make test TFLAGS+="-nrk -DLFS_READ_SIZE=11 -DLFS_BLOCK_SIZE=704"
 
-  # run tests
-  - make test QUIET=1
-
-  # run tests with a few different configurations
-  - make test QUIET=1 CFLAGS+="-DLFS_READ_SIZE=1      -DLFS_CACHE_SIZE=4"
-  - make test QUIET=1 CFLAGS+="-DLFS_READ_SIZE=512    -DLFS_CACHE_SIZE=512 -DLFS_BLOCK_CYCLES=16"
-  - make test QUIET=1 CFLAGS+="-DLFS_READ_SIZE=8      -DLFS_CACHE_SIZE=16  -DLFS_BLOCK_CYCLES=2"
-  - make test QUIET=1 CFLAGS+="-DLFS_BLOCK_COUNT=1023 -DLFS_LOOKAHEAD_SIZE=256"
-
-  - make clean test QUIET=1 CFLAGS+="-DLFS_INLINE_MAX=0"
-  - make clean test QUIET=1 CFLAGS+="-DLFS_EMUBD_ERASE_VALUE=0xff"
-  - make clean test QUIET=1 CFLAGS+="-DLFS_NO_INTRINSICS"
-
-  # additional configurations that don't support all tests (this should be
-  # fixed but at the moment it is what it is)
-  - make test_files QUIET=1
-        CFLAGS+="-DLFS_READ_SIZE=1 -DLFS_BLOCK_SIZE=4096"
-  - make test_files QUIET=1
-        CFLAGS+="-DLFS_READ_SIZE=\(2*1024\) -DLFS_BLOCK_SIZE=\(64*1024\)"
-  - make test_files QUIET=1
-        CFLAGS+="-DLFS_READ_SIZE=\(8*1024\) -DLFS_BLOCK_SIZE=\(64*1024\)"
-  - make test_files QUIET=1
-        CFLAGS+="-DLFS_READ_SIZE=11 -DLFS_BLOCK_SIZE=704"
-
+# report size 
+_: &report-size
   # compile and find the code size with the smallest configuration
-  - make clean size
-        OBJ="$(ls lfs*.o | tr '\n' ' ')"
+  - make -j1 clean size
+        OBJ="$(ls lfs*.c | sed 's/\.c/\.o/' | tr '\n' ' ')"
         CFLAGS+="-DLFS_NO_ASSERT -DLFS_NO_DEBUG -DLFS_NO_WARN -DLFS_NO_ERROR"
         | tee sizes
-
   # update status if we succeeded, compare with master if possible
   - |
     if [ "$TRAVIS_TEST_RESULT" -eq 0 ]
@@ -51,7 +72,7 @@ script:
         CURR=$(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/$NAME\").description
+                | .statuses[] | select(.context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\").description
                 | capture(\"code size is (?<size>[0-9]+)\").size" \
             || echo 0)
   
@@ -62,79 +83,150 @@ script:
         fi
     fi
 
-# CI matrix
+# stage control
+stages:
+  - name: test
+  - name: deploy
+    if: branch = master AND type = push
+
+# job control
 jobs:
-  include:
   # native testing
-    - stage: test
+  - &x86
+    stage: test
     env:
-        - STAGE=test
       - NAME=littlefs-x86
+    install: *install-common
+    script: [*test-example, *report-size]
+  - {<<: *x86, script: [*test-default,          *report-size]}
+  - {<<: *x86, script: [*test-nor,              *report-size]}
+  - {<<: *x86, script: [*test-emmc,             *report-size]}
+  - {<<: *x86, script: [*test-nand,             *report-size]}
+  - {<<: *x86, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *x86, script: [*test-no-inline,        *report-size]}
+  - {<<: *x86, script: [*test-byte-writes,      *report-size]}
+  - {<<: *x86, script: [*test-block-cycles,     *report-size]}
+  - {<<: *x86, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *x86, script: [*test-odd-block-size,   *report-size]}
 
   # cross-compile with ARM (thumb mode)
-    - stage: test
+  - &arm
+    stage: test
     env:
-        - STAGE=test
       - NAME=littlefs-arm
       - CC="arm-linux-gnueabi-gcc --static -mthumb"
-        - EXEC="qemu-arm"
+      - TFLAGS="$TFLAGS --exec=qemu-arm"
     install:
+      - *install-common
       - sudo apt-get install
             gcc-arm-linux-gnueabi
             libc6-dev-armel-cross
             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
-              libc6-dev-powerpc-cross
-              qemu-user
-        - powerpc-linux-gnu-gcc --version
-        - qemu-ppc -version
+    script: [*test-example, *report-size]
+  - {<<: *arm, script: [*test-default,          *report-size]}
+  - {<<: *arm, script: [*test-nor,              *report-size]}
+  - {<<: *arm, script: [*test-emmc,             *report-size]}
+  - {<<: *arm, script: [*test-nand,             *report-size]}
+  - {<<: *arm, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *arm, script: [*test-no-inline,        *report-size]}
+  # it just takes way to long to run byte-level writes in qemu,
+  # note this is still tested in the native tests
+  #- {<<: *arm, script: [*test-byte-writes,      *report-size]}
+  - {<<: *arm, script: [*test-block-cycles,     *report-size]}
+  - {<<: *arm, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *arm, script: [*test-odd-block-size,   *report-size]}
 
   # cross-compile with MIPS
-    - stage: test
+  - &mips
+    stage: test
     env:
-        - STAGE=test
       - NAME=littlefs-mips
       - CC="mips-linux-gnu-gcc --static"
-        - EXEC="qemu-mips"
+      - TFLAGS="$TFLAGS --exec=qemu-mips"
     install:
+      - *install-common
       - sudo apt-get install
             gcc-mips-linux-gnu
             libc6-dev-mips-cross
             qemu-user
       - mips-linux-gnu-gcc --version
       - qemu-mips -version
+    script: [*test-example, *report-size]
+  - {<<: *mips, script: [*test-default,          *report-size]}
+  - {<<: *mips, script: [*test-nor,              *report-size]}
+  - {<<: *mips, script: [*test-emmc,             *report-size]}
+  - {<<: *mips, script: [*test-nand,             *report-size]}
+  - {<<: *mips, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *mips, script: [*test-no-inline,        *report-size]}
+  # it just takes way to long to run byte-level writes in qemu,
+  # note this is still tested in the native tests
+  #- {<<: *mips, script: [*test-byte-writes,      *report-size]}
+  - {<<: *mips, script: [*test-block-cycles,     *report-size]}
+  - {<<: *mips, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *mips, script: [*test-odd-block-size,   *report-size]}
+
+  # cross-compile with PowerPC
+  - &powerpc
+    stage: test
+    env:
+      - NAME=littlefs-powerpc
+      - CC="powerpc-linux-gnu-gcc --static"
+      - TFLAGS="$TFLAGS --exec=qemu-ppc"
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-powerpc-linux-gnu
+            libc6-dev-powerpc-cross
+            qemu-user
+      - powerpc-linux-gnu-gcc --version
+      - qemu-ppc -version
+    script: [*test-example, *report-size]
+  - {<<: *powerpc, script: [*test-default,          *report-size]}
+  - {<<: *powerpc, script: [*test-nor,              *report-size]}
+  - {<<: *powerpc, script: [*test-emmc,             *report-size]}
+  - {<<: *powerpc, script: [*test-nand,             *report-size]}
+  - {<<: *powerpc, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *powerpc, script: [*test-no-inline,        *report-size]}
+  # it just takes way to long to run byte-level writes in qemu,
+  # note this is still tested in the native tests
+  #- {<<: *powerpc, script: [*test-byte-writes,      *report-size]}
+  - {<<: *powerpc, script: [*test-block-cycles,     *report-size]}
+  - {<<: *powerpc, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *powerpc, script: [*test-odd-block-size,   *report-size]}
+
+  # test under valgrind, checking for memory errors
+  - &valgrind
+    stage: test
+    env:
+      - NAME=littlefs-valgrind
+    install:
+      - *install-common
+      - sudo apt-get install valgrind
+      - valgrind --version
+    script:
+      - make test TFLAGS+="-k --valgrind"
 
   # self-host with littlefs-fuse for fuzz test
   - stage: test
     env:
-        - STAGE=test
       - NAME=littlefs-fuse
     if: branch !~ -prefix$
     install:
+      - *install-common
       - sudo apt-get install libfuse-dev
       - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2
       - fusermount -V
       - gcc --version
-      before_script:
+
       # setup disk for littlefs-fuse
       - rm -rf littlefs-fuse/littlefs/*
       - cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs
 
       - mkdir mount
       - sudo chmod a+rw /dev/loop0
-        - dd if=/dev/zero bs=512 count=4096 of=disk
+      - dd if=/dev/zero bs=512 count=128K of=disk
       - losetup /dev/loop0 disk
     script:
       # self-host test
@@ -149,28 +241,28 @@ jobs:
       - cd mount/littlefs
       - stat .
       - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      - make -B test
 
-    # self-host with littlefs-fuse for fuzz test
+  # test migration using littlefs-fuse
   - stage: test
     env:
-        - STAGE=test
       - NAME=littlefs-migration
     if: branch !~ -prefix$
     install:
+      - *install-common
       - sudo apt-get install libfuse-dev
       - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2 v2
       - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v1 v1
       - fusermount -V
       - gcc --version
-      before_script:
+
       # setup disk for littlefs-fuse
       - rm -rf v2/littlefs/*
       - cp -r $(git ls-tree --name-only HEAD) v2/littlefs
 
       - mkdir mount
       - sudo chmod a+rw /dev/loop0
-        - dd if=/dev/zero bs=512 count=4096 of=disk
+      - dd if=/dev/zero bs=512 count=128K of=disk
       - losetup /dev/loop0 disk
     script:
       # compile v1 and v2
@@ -187,7 +279,7 @@ jobs:
       - cd mount/littlefs
       - stat .
       - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      - make -B test
 
       # attempt to migrate
       - cd ../..
@@ -201,12 +293,11 @@ jobs:
       - cd mount/littlefs
       - stat .
       - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      - make -B test
 
-    # Automatically create releases
+  # automatically create releases
   - stage: deploy
     env:
-        - STAGE=deploy
       - NAME=deploy
     script:
       - |
@@ -277,42 +368,62 @@ jobs:
             }" #"
         SCRIPT
 
-# Manage statuses
+# manage statuses
 before_install:
   - |
+    # don't clobber other (not us) failures
+    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        | jq -e ".statuses[] | select(
+            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
+            .state == \"failure\" and
+            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
+    then
         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\",
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
                 \"state\": \"pending\",
                 \"description\": \"${STATUS:-In progress}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
             }"
+    fi
 
 after_failure:
   - |
+    # don't clobber other (not us) failures
+    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        | jq -e ".statuses[] | select(
+            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
+            .state == \"failure\" and
+            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
+    then
         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\",
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
                 \"state\": \"failure\",
                 \"description\": \"${STATUS:-Failed}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
             }"
+    fi
 
 after_success:
   - |
+    # don't clobber other (not us) failures
+    # only update if we were last job to mark in progress,
+    # this isn't perfect but is probably good enough
+    if ! curl https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        | jq -e ".statuses[] | select(
+            .context == \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\" and
+            (.state == \"failure\" or .state == \"pending\") and
+            (.target_url | endswith(\"$TRAVIS_JOB_NUMBER\") | not))"
+    then
         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\",
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
                 \"state\": \"success\",
                 \"description\": \"${STATUS:-Passed}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
             }"
-
-# Job control
-stages:
-    - name: test
-    - name: deploy
-      if: branch = master AND type = push
+    fi

Makefile

@@ -26,8 +26,6 @@ endif
 override CFLAGS += -I.
 override CFLAGS += -std=c99 -Wall -pedantic
 override CFLAGS += -Wextra -Wshadow -Wjump-misses-init -Wundef
-# Remove missing-field-initializers because of GCC bug
-override CFLAGS += -Wno-missing-field-initializers
 
 ifdef VERBOSE
 override TFLAGS += -v
@@ -45,7 +43,7 @@ test:
 	./scripts/test.py $(TFLAGS)
 .SECONDEXPANSION:
 test%: tests/test$$(firstword $$(subst \#, ,%)).toml
-	./scripts/test.py $(TFLAGS) $@
+	./scripts/test.py $@ $(TFLAGS)
 
 -include $(DEP)
 

README.md

@@ -115,6 +115,9 @@ the filesystem until sync or close is called on the file.
 
 ## Other notes
 
+Littlefs is written in C, and specifically should compile with any compiler
+that conforms to the `C99` standard.
+
 All littlefs calls 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), or an error returned by the user's block device operations.

SPEC.md

@@ -289,7 +289,7 @@ Layout of the name tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][---            (size)             ---]
+[1| 3| 8 | 10 | 10 ][---          (size * 8)           ---]
  ^  ^  ^    ^    ^- size                   ^- file name
  |  |  |    '------ id
  |  |  '----------- file type
@@ -470,7 +470,7 @@ Layout of the inline-struct tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1|- 11 -| 10 | 10 ][---            (size)             ---]
+[1|- 11 -| 10 | 10 ][---           (size * 8)          ---]
  ^    ^     ^    ^- size                    ^- inline data
  |    |     '------ id
  |    '------------ type (0x201)
@@ -556,7 +556,7 @@ Layout of the user-attr tag:
 ```
         tag                          data
 [--      32      --][---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][---            (size)             ---]
+[1| 3| 8 | 10 | 10 ][---           (size * 8)          ---]
  ^  ^  ^    ^    ^- size                    ^- attr data
  |  |  |    '------ id
  |  |  '----------- attr type
@@ -764,9 +764,9 @@ Layout of the CRC tag:
 ```
         tag                                    data
 [--      32      --][--      32      --|---        variable length        ---]
-[1| 3| 8 | 10 | 10 ][--      32      --|---            (size)             ---]
+[1| 3| 8 | 10 | 10 ][--      32      --|---        (size * 8 - 32)        ---]
  ^  ^  ^    ^    ^            ^- crc                             ^- padding
- |  |  |    |    '- size (12)
+ |  |  |    |    '- size
  |  |  |    '------ id (0x3ff)
  |  |  '----------- valid state
  |  '-------------- type1 (0x5)

bd/lfs_filebd.c

@@ -12,7 +12,7 @@
 
 int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
         const struct lfs_filebd_config *bdcfg) {
-    LFS_TRACE("lfs_filebd_createcfg(%p {.context=%p, "
+    LFS_FILEBD_TRACE("lfs_filebd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -30,16 +30,16 @@ int lfs_filebd_createcfg(const struct lfs_config *cfg, const char *path,
     bd->fd = open(path, O_RDWR | O_CREAT, 0666);
     if (bd->fd < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_createcfg -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_createcfg -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_createcfg -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_TRACE("lfs_filebd_create(%p {.context=%p, "
+    LFS_FILEBD_TRACE("lfs_filebd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -51,26 +51,27 @@ int lfs_filebd_create(const struct lfs_config *cfg, const char *path) {
             path);
     static const struct lfs_filebd_config defaults = {.erase_value=-1};
     int err = lfs_filebd_createcfg(cfg, path, &defaults);
-    LFS_TRACE("lfs_filebd_create -> %d", err);
+    LFS_FILEBD_TRACE("lfs_filebd_create -> %d", err);
     return err;
 }
 
 int lfs_filebd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
+    LFS_FILEBD_TRACE("lfs_filebd_destroy(%p)", (void*)cfg);
     lfs_filebd_t *bd = cfg->context;
     int err = close(bd->fd);
     if (err < 0) {
         err = -errno;
-        LFS_TRACE("lfs_filebd_destroy -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", err);
         return err;
     }
-    LFS_TRACE("lfs_filebd_destroy -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_destroy -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_filebd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_FILEBD_TRACE("lfs_filebd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_filebd_t *bd = cfg->context;
 
@@ -89,24 +90,24 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
             (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_read -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
         return err;
     }
 
     ssize_t res2 = read(bd->fd, buffer, size);
     if (res2 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_read -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_read -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_read -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_read -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_filebd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_FILEBD_TRACE("lfs_filebd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_filebd_t *bd = cfg->context;
 
@@ -121,7 +122,7 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
                 (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
-            LFS_TRACE("lfs_filebd_prog -> %d", err);
+            LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
             return err;
         }
 
@@ -130,7 +131,7 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
             ssize_t res2 = read(bd->fd, &c, 1);
             if (res2 < 0) {
                 int err = -errno;
-                LFS_TRACE("lfs_filebd_prog -> %d", err);
+                LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
                 return err;
             }
 
@@ -143,23 +144,23 @@ int lfs_filebd_prog(const struct lfs_config *cfg, lfs_block_t block,
             (off_t)block*cfg->block_size + (off_t)off, SEEK_SET);
     if (res1 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_prog -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
         return err;
     }
 
     ssize_t res2 = write(bd->fd, buffer, size);
     if (res2 < 0) {
         int err = -errno;
-        LFS_TRACE("lfs_filebd_prog -> %d", err);
+        LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", err);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_prog -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_FILEBD_TRACE("lfs_filebd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_filebd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -170,7 +171,7 @@ int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
         off_t res1 = lseek(bd->fd, (off_t)block*cfg->block_size, SEEK_SET);
         if (res1 < 0) {
             int err = -errno;
-            LFS_TRACE("lfs_filebd_erase -> %d", err);
+            LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
             return err;
         }
 
@@ -178,27 +179,27 @@ int lfs_filebd_erase(const struct lfs_config *cfg, lfs_block_t block) {
             ssize_t res2 = write(bd->fd, &(uint8_t){bd->cfg->erase_value}, 1);
             if (res2 < 0) {
                 int err = -errno;
-                LFS_TRACE("lfs_filebd_erase -> %d", err);
+                LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", err);
                 return err;
             }
         }
     }
 
-    LFS_TRACE("lfs_filebd_erase -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_erase -> %d", 0);
     return 0;
 }
 
 int lfs_filebd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
+    LFS_FILEBD_TRACE("lfs_filebd_sync(%p)", (void*)cfg);
     // file sync
     lfs_filebd_t *bd = cfg->context;
     int err = fsync(bd->fd);
     if (err) {
         err = -errno;
-        LFS_TRACE("lfs_filebd_sync -> %d", 0);
+        LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
         return err;
     }
 
-    LFS_TRACE("lfs_filebd_sync -> %d", 0);
+    LFS_FILEBD_TRACE("lfs_filebd_sync -> %d", 0);
     return 0;
 }

bd/lfs_filebd.h

@@ -15,6 +15,14 @@ extern "C"
 {
 #endif
 
+
+// Block device specific tracing
+#ifdef LFS_FILEBD_YES_TRACE
+#define LFS_FILEBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_FILEBD_TRACE(...)
+#endif
+
 // filebd config (optional)
 struct lfs_filebd_config {
     // 8-bit erase value to use for simulating erases. -1 does not simulate

bd/lfs_rambd.c

@@ -8,7 +8,7 @@
 
 int lfs_rambd_createcfg(const struct lfs_config *cfg,
         const struct lfs_rambd_config *bdcfg) {
-    LFS_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
+    LFS_RAMBD_TRACE("lfs_rambd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -27,7 +27,7 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
     } else {
         bd->buffer = lfs_malloc(cfg->block_size * cfg->block_count);
         if (!bd->buffer) {
-            LFS_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
+            LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", LFS_ERR_NOMEM);
             return LFS_ERR_NOMEM;
         }
     }
@@ -38,12 +38,12 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
                 cfg->block_size * cfg->block_count);
     }
 
-    LFS_TRACE("lfs_rambd_createcfg -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_create(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_create(%p {.context=%p, "
+    LFS_RAMBD_TRACE("lfs_rambd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"})",
@@ -53,24 +53,25 @@ int lfs_rambd_create(const struct lfs_config *cfg) {
             cfg->read_size, cfg->prog_size, cfg->block_size, cfg->block_count);
     static const struct lfs_rambd_config defaults = {.erase_value=-1};
     int err = lfs_rambd_createcfg(cfg, &defaults);
-    LFS_TRACE("lfs_rambd_create -> %d", err);
+    LFS_RAMBD_TRACE("lfs_rambd_create -> %d", err);
     return err;
 }
 
 int lfs_rambd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
+    LFS_RAMBD_TRACE("lfs_rambd_destroy(%p)", (void*)cfg);
     // clean up memory
     lfs_rambd_t *bd = cfg->context;
     if (!bd->cfg->buffer) {
         lfs_free(bd->buffer);
     }
-    LFS_TRACE("lfs_rambd_destroy -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_destroy -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_rambd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_RAMBD_TRACE("lfs_rambd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_rambd_t *bd = cfg->context;
 
@@ -82,13 +83,14 @@ int lfs_rambd_read(const struct lfs_config *cfg, lfs_block_t block,
     // read data
     memcpy(buffer, &bd->buffer[block*cfg->block_size + off], size);
 
-    LFS_TRACE("lfs_rambd_read -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_read -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_rambd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_RAMBD_TRACE("lfs_rambd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_rambd_t *bd = cfg->context;
 
@@ -108,12 +110,12 @@ int lfs_rambd_prog(const struct lfs_config *cfg, lfs_block_t block,
     // program data
     memcpy(&bd->buffer[block*cfg->block_size + off], buffer, size);
 
-    LFS_TRACE("lfs_rambd_prog -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_RAMBD_TRACE("lfs_rambd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_rambd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -125,14 +127,14 @@ int lfs_rambd_erase(const struct lfs_config *cfg, lfs_block_t block) {
                 bd->cfg->erase_value, cfg->block_size);
     }
 
-    LFS_TRACE("lfs_rambd_erase -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_erase -> %d", 0);
     return 0;
 }
 
 int lfs_rambd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
+    LFS_RAMBD_TRACE("lfs_rambd_sync(%p)", (void*)cfg);
     // sync does nothing because we aren't backed by anything real
     (void)cfg;
-    LFS_TRACE("lfs_rambd_sync -> %d", 0);
+    LFS_RAMBD_TRACE("lfs_rambd_sync -> %d", 0);
     return 0;
 }

bd/lfs_rambd.h

@@ -15,6 +15,14 @@ extern "C"
 {
 #endif
 
+
+// Block device specific tracing
+#ifdef LFS_RAMBD_YES_TRACE
+#define LFS_RAMBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_RAMBD_TRACE(...)
+#endif
+
 // rambd config (optional)
 struct lfs_rambd_config {
     // 8-bit erase value to simulate erasing with. -1 indicates no erase

bd/lfs_testbd.c

@@ -12,7 +12,7 @@
 
 int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
         const struct lfs_testbd_config *bdcfg) {
-    LFS_TRACE("lfs_testbd_createcfg(%p {.context=%p, "
+    LFS_TESTBD_TRACE("lfs_testbd_createcfg(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -38,9 +38,9 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
         if (bd->cfg->wear_buffer) {
             bd->wear = bd->cfg->wear_buffer;
         } else {
-            bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t) * cfg->block_count);
+            bd->wear = lfs_malloc(sizeof(lfs_testbd_wear_t)*cfg->block_count);
             if (!bd->wear) {
-                LFS_TRACE("lfs_testbd_createcfg -> %d", LFS_ERR_NOMEM);
+                LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", LFS_ERR_NOMEM);
                 return LFS_ERR_NOMEM;
             }
         }
@@ -54,7 +54,7 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
             .erase_value = bd->cfg->erase_value,
         };
         int err = lfs_filebd_createcfg(cfg, path, &bd->u.file.cfg);
-        LFS_TRACE("lfs_testbd_createcfg -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     } else {
         bd->u.ram.cfg = (struct lfs_rambd_config){
@@ -62,13 +62,13 @@ int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
             .buffer = bd->cfg->buffer,
         };
         int err = lfs_rambd_createcfg(cfg, &bd->u.ram.cfg);
-        LFS_TRACE("lfs_testbd_createcfg -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_createcfg -> %d", err);
         return err;
     }
 }
 
 int lfs_testbd_create(const struct lfs_config *cfg, const char *path) {
-    LFS_TRACE("lfs_testbd_create(%p {.context=%p, "
+    LFS_TESTBD_TRACE("lfs_testbd_create(%p {.context=%p, "
                 ".read=%p, .prog=%p, .erase=%p, .sync=%p, "
                 ".read_size=%"PRIu32", .prog_size=%"PRIu32", "
                 ".block_size=%"PRIu32", .block_count=%"PRIu32"}, "
@@ -80,12 +80,12 @@ int lfs_testbd_create(const struct lfs_config *cfg, const char *path) {
             path);
     static const struct lfs_testbd_config defaults = {.erase_value=-1};
     int err = lfs_testbd_createcfg(cfg, path, &defaults);
-    LFS_TRACE("lfs_testbd_create -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_create -> %d", err);
     return err;
 }
 
 int lfs_testbd_destroy(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_testbd_destroy(%p)", (void*)cfg);
+    LFS_TESTBD_TRACE("lfs_testbd_destroy(%p)", (void*)cfg);
     lfs_testbd_t *bd = cfg->context;
     if (bd->cfg->erase_cycles && !bd->cfg->wear_buffer) {
         lfs_free(bd->wear);
@@ -93,11 +93,11 @@ int lfs_testbd_destroy(const struct lfs_config *cfg) {
 
     if (bd->persist) {
         int err = lfs_filebd_destroy(cfg);
-        LFS_TRACE("lfs_testbd_destroy -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
         return err;
     } else {
         int err = lfs_rambd_destroy(cfg);
-        LFS_TRACE("lfs_testbd_destroy -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_destroy -> %d", err);
         return err;
     }
 }
@@ -145,7 +145,8 @@ static int lfs_testbd_rawsync(const struct lfs_config *cfg) {
 /// block device API ///
 int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_testbd_read(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_TESTBD_TRACE("lfs_testbd_read(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_testbd_t *bd = cfg->context;
 
@@ -155,22 +156,22 @@ int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
     LFS_ASSERT(block < cfg->block_count);
 
     // block bad?
-    if (bd->cfg->erase_cycles &&
-            bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_NOREAD &&
-            bd->wear[block] >= bd->cfg->erase_cycles) {
-        LFS_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
+    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles &&
+            bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_READERROR) {
+        LFS_TESTBD_TRACE("lfs_testbd_read -> %d", LFS_ERR_CORRUPT);
         return LFS_ERR_CORRUPT;
     }
 
     // read
     int err = lfs_testbd_rawread(cfg, block, off, buffer, size);
-    LFS_TRACE("lfs_testbd_read -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_read -> %d", err);
     return err;
 }
 
 int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
         lfs_off_t off, const void *buffer, lfs_size_t size) {
-    LFS_TRACE("lfs_testbd_prog(%p, 0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
+    LFS_TESTBD_TRACE("lfs_testbd_prog(%p, "
+                "0x%"PRIx32", %"PRIu32", %p, %"PRIu32")",
             (void*)cfg, block, off, buffer, size);
     lfs_testbd_t *bd = cfg->context;
 
@@ -180,17 +181,24 @@ int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
     LFS_ASSERT(block < cfg->block_count);
 
     // block bad?
-    if (bd->cfg->erase_cycles &&
-            bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_NOPROG &&
-            bd->wear[block] >= bd->cfg->erase_cycles) {
-        LFS_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
+    if (bd->cfg->erase_cycles && bd->wear[block] >= bd->cfg->erase_cycles) {
+        if (bd->cfg->badblock_behavior ==
+                LFS_TESTBD_BADBLOCK_PROGERROR) {
+            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", LFS_ERR_CORRUPT);
             return LFS_ERR_CORRUPT;
+        } else if (bd->cfg->badblock_behavior ==
+                LFS_TESTBD_BADBLOCK_PROGNOOP ||
+                bd->cfg->badblock_behavior ==
+                LFS_TESTBD_BADBLOCK_ERASENOOP) {
+            LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
+            return 0;
+        }
     }
 
     // prog
     int err = lfs_testbd_rawprog(cfg, block, off, buffer, size);
     if (err) {
-        LFS_TRACE("lfs_testbd_prog -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", err);
         return err;
     }
 
@@ -205,12 +213,12 @@ int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
         }
     }
 
-    LFS_TRACE("lfs_testbd_prog -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
-    LFS_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_erase(%p, 0x%"PRIx32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if erase is valid
@@ -219,9 +227,14 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     // block bad?
     if (bd->cfg->erase_cycles) {
         if (bd->wear[block] >= bd->cfg->erase_cycles) {
-            if (bd->cfg->badblock_behavior == LFS_TESTBD_BADBLOCK_NOERASE) {
-                LFS_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
+            if (bd->cfg->badblock_behavior ==
+                    LFS_TESTBD_BADBLOCK_ERASEERROR) {
+                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", LFS_ERR_CORRUPT);
                 return LFS_ERR_CORRUPT;
+            } else if (bd->cfg->badblock_behavior ==
+                    LFS_TESTBD_BADBLOCK_ERASENOOP) {
+                LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", 0);
+                return 0;
             }
         } else {
             // mark wear
@@ -232,7 +245,7 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
     // erase
     int err = lfs_testbd_rawerase(cfg, block);
     if (err) {
-        LFS_TRACE("lfs_testbd_erase -> %d", err);
+        LFS_TESTBD_TRACE("lfs_testbd_erase -> %d", err);
         return err;
     }
 
@@ -247,14 +260,14 @@ int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block) {
         }
     }
 
-    LFS_TRACE("lfs_testbd_prog -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_prog -> %d", 0);
     return 0;
 }
 
 int lfs_testbd_sync(const struct lfs_config *cfg) {
-    LFS_TRACE("lfs_testbd_sync(%p)", (void*)cfg);
+    LFS_TESTBD_TRACE("lfs_testbd_sync(%p)", (void*)cfg);
     int err = lfs_testbd_rawsync(cfg);
-    LFS_TRACE("lfs_testbd_sync -> %d", err);
+    LFS_TESTBD_TRACE("lfs_testbd_sync -> %d", err);
     return err;
 }
 
@@ -262,20 +275,20 @@ int lfs_testbd_sync(const struct lfs_config *cfg) {
 /// simulated wear operations ///
 lfs_testbd_swear_t lfs_testbd_getwear(const struct lfs_config *cfg,
         lfs_block_t block) {
-    LFS_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_getwear(%p, %"PRIu32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if block is valid
     LFS_ASSERT(bd->cfg->erase_cycles);
     LFS_ASSERT(block < cfg->block_count);
 
-    LFS_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
+    LFS_TESTBD_TRACE("lfs_testbd_getwear -> %"PRIu32, bd->wear[block]);
     return bd->wear[block];
 }
 
 int lfs_testbd_setwear(const struct lfs_config *cfg,
         lfs_block_t block, lfs_testbd_wear_t wear) {
-    LFS_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)cfg, block);
+    LFS_TESTBD_TRACE("lfs_testbd_setwear(%p, %"PRIu32")", (void*)cfg, block);
     lfs_testbd_t *bd = cfg->context;
 
     // check if block is valid
@@ -284,6 +297,6 @@ int lfs_testbd_setwear(const struct lfs_config *cfg,
 
     bd->wear[block] = wear;
 
-    LFS_TRACE("lfs_testbd_setwear -> %d", 0);
+    LFS_TESTBD_TRACE("lfs_testbd_setwear -> %d", 0);
     return 0;
 }

bd/lfs_testbd.h

@@ -19,14 +19,25 @@ extern "C"
 #endif
 
 
-// Mode determining how "bad blocks" behave during testing. This
-// simulates some real-world circumstances such as writes not
-// going through (noprog), erases not sticking (noerase), and ECC
-// failures (noread).
+// Block device specific tracing
+#ifdef LFS_TESTBD_YES_TRACE
+#define LFS_TESTBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
+#else
+#define LFS_TESTBD_TRACE(...)
+#endif
+
+// Mode determining how "bad blocks" behave during testing. This simulates
+// some real-world circumstances such as progs not sticking (prog-noop),
+// a readonly disk (erase-noop), and ECC failures (read-error).
+//
+// Not that read-noop is not allowed. Read _must_ return a consistent (but
+// may be arbitrary) value on every read.
 enum lfs_testbd_badblock_behavior {
-    LFS_TESTBD_BADBLOCK_NOPROG  = 0,
-    LFS_TESTBD_BADBLOCK_NOERASE = 1,
-    LFS_TESTBD_BADBLOCK_NOREAD  = 2,
+    LFS_TESTBD_BADBLOCK_PROGERROR,
+    LFS_TESTBD_BADBLOCK_ERASEERROR,
+    LFS_TESTBD_BADBLOCK_READERROR,
+    LFS_TESTBD_BADBLOCK_PROGNOOP,
+    LFS_TESTBD_BADBLOCK_ERASENOOP,
 };
 
 // Type for measuring wear

lfs.c

@@ -29,8 +29,8 @@ static int lfs_bd_read(lfs_t *lfs,
         lfs_block_t block, lfs_off_t off,
         void *buffer, lfs_size_t size) {
     uint8_t *data = buffer;
-    LFS_ASSERT(block != LFS_BLOCK_NULL);
-    if (off+size > lfs->cfg->block_size) {
+    if (block >= lfs->cfg->block_count ||
+            off+size > lfs->cfg->block_size) {
         return LFS_ERR_CORRUPT;
     }
 
@@ -71,6 +71,21 @@ static int lfs_bd_read(lfs_t *lfs,
             diff = lfs_min(diff, rcache->off-off);
         }
 
+        if (size >= hint && off % lfs->cfg->read_size == 0 &&
+                size >= lfs->cfg->read_size) {
+            // bypass cache?
+            diff = lfs_aligndown(diff, lfs->cfg->read_size);
+            int err = lfs->cfg->read(lfs->cfg, block, off, data, diff);
+            if (err) {
+                return err;
+            }
+
+            data += diff;
+            off += diff;
+            size -= diff;
+            continue;
+        }
+
         // load to cache, first condition can no longer fail
         LFS_ASSERT(block < lfs->cfg->block_count);
         rcache->block = block;
@@ -173,7 +188,7 @@ static int lfs_bd_prog(lfs_t *lfs,
         lfs_block_t block, lfs_off_t off,
         const void *buffer, lfs_size_t size) {
     const uint8_t *data = buffer;
-    LFS_ASSERT(block != LFS_BLOCK_NULL);
+    LFS_ASSERT(block == LFS_BLOCK_INLINE || block < lfs->cfg->block_count);
     LFS_ASSERT(off + size <= lfs->cfg->block_size);
 
     while (size > 0) {
@@ -269,7 +284,7 @@ typedef int32_t lfs_stag_t;
     ((cond) ? LFS_MKTAG(type, id, size) : LFS_MKTAG(LFS_FROM_NOOP, 0, 0))
 
 #define LFS_MKTAG_IF_ELSE(cond, type1, id1, size1, type2, id2, size2) \
-    ((cond) ? LFS_MKTAG(type, id, size) : LFS_MKTAG(type2, id2, size2))
+    ((cond) ? LFS_MKTAG(type1, id1, size1) : LFS_MKTAG(type2, id2, size2))
 
 static inline bool lfs_tag_isvalid(lfs_tag_t tag) {
     return !(tag & 0x80000000);
@@ -414,6 +429,9 @@ static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t dir[2],
         lfs_mdir_t *parent);
 static int lfs_fs_relocate(lfs_t *lfs,
         const lfs_block_t oldpair[2], lfs_block_t newpair[2]);
+int lfs_fs_traverseraw(lfs_t *lfs,
+        int (*cb)(void *data, lfs_block_t block), void *data,
+        bool includeorphans);
 static int lfs_fs_forceconsistency(lfs_t *lfs);
 static int lfs_deinit(lfs_t *lfs);
 #ifdef LFS_MIGRATE
@@ -434,6 +452,21 @@ static int lfs_alloc_lookahead(void *p, lfs_block_t block) {
     return 0;
 }
 
+// indicate allocated blocks have been committed into the filesystem, this
+// is to prevent blocks from being garbage collected in the middle of a
+// commit operation
+static void lfs_alloc_ack(lfs_t *lfs) {
+    lfs->free.ack = lfs->cfg->block_count;
+}
+
+// drop the lookahead buffer, this is done during mounting and failed
+// traversals in order to avoid invalid lookahead state
+static void lfs_alloc_drop(lfs_t *lfs) {
+    lfs->free.size = 0;
+    lfs->free.i = 0;
+    lfs_alloc_ack(lfs);
+}
+
 static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
     while (true) {
         while (lfs->free.i != lfs->free.size) {
@@ -472,18 +505,14 @@ static int lfs_alloc(lfs_t *lfs, lfs_block_t *block) {
 
         // find mask of free blocks from tree
         memset(lfs->free.buffer, 0, lfs->cfg->lookahead_size);
-        int err = lfs_fs_traverse(lfs, lfs_alloc_lookahead, lfs);
+        int err = lfs_fs_traverseraw(lfs, lfs_alloc_lookahead, lfs, true);
         if (err) {
+            lfs_alloc_drop(lfs);
             return err;
         }
     }
 }
 
-static void lfs_alloc_ack(lfs_t *lfs) {
-    lfs->free.ack = lfs->cfg->block_count;
-}
-
-
 /// Metadata pair and directory operations ///
 static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
         lfs_tag_t gmask, lfs_tag_t gtag,
@@ -711,7 +740,7 @@ static int lfs_dir_traverse(lfs_t *lfs,
             uint16_t fromid = lfs_tag_size(tag);
             uint16_t toid = lfs_tag_id(tag);
             int err = lfs_dir_traverse(lfs,
-                    buffer, 0, LFS_BLOCK_NULL, NULL, 0,
+                    buffer, 0, 0xffffffff, NULL, 0,
                     LFS_MKTAG(0x600, 0x3ff, 0),
                     LFS_MKTAG(LFS_TYPE_STRUCT, 0, 0),
                     fromid, fromid+1, toid-fromid+diff,
@@ -745,6 +774,12 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
     // scanning the entire directory
     lfs_stag_t besttag = -1;
 
+    // if either block address is invalid we return LFS_ERR_CORRUPT here,
+    // otherwise later writes to the pair could fail
+    if (pair[0] >= lfs->cfg->block_count || pair[1] >= lfs->cfg->block_count) {
+        return LFS_ERR_CORRUPT;
+    }
+
     // find the block with the most recent revision
     uint32_t revs[2] = {0, 0};
     int r = 0;
@@ -771,7 +806,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
     // now scan tags to fetch the actual dir and find possible match
     for (int i = 0; i < 2; i++) {
         lfs_off_t off = 0;
-        lfs_tag_t ptag = LFS_BLOCK_NULL;
+        lfs_tag_t ptag = 0xffffffff;
 
         uint16_t tempcount = 0;
         lfs_block_t temptail[2] = {LFS_BLOCK_NULL, LFS_BLOCK_NULL};
@@ -779,7 +814,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
         lfs_stag_t tempbesttag = besttag;
 
         dir->rev = lfs_tole32(dir->rev);
-        uint32_t crc = lfs_crc(LFS_BLOCK_NULL, &dir->rev, sizeof(dir->rev));
+        uint32_t crc = lfs_crc(0xffffffff, &dir->rev, sizeof(dir->rev));
         dir->rev = lfs_fromle32(dir->rev);
 
         while (true) {
@@ -802,11 +837,13 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
             tag = lfs_frombe32(tag) ^ ptag;
 
             // next commit not yet programmed or we're not in valid range
-            if (!lfs_tag_isvalid(tag) ||
-                    off + lfs_tag_dsize(tag) > lfs->cfg->block_size) {
+            if (!lfs_tag_isvalid(tag)) {
                 dir->erased = (lfs_tag_type1(ptag) == LFS_TYPE_CRC &&
                         dir->off % lfs->cfg->prog_size == 0);
                 break;
+            } else if (off + lfs_tag_dsize(tag) > lfs->cfg->block_size) {
+                dir->erased = false;
+                break;
             }
 
             ptag = tag;
@@ -835,8 +872,10 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                 ptag ^= (lfs_tag_t)(lfs_tag_chunk(tag) & 1U) << 31;
 
                 // toss our crc into the filesystem seed for
-                // pseudorandom numbers
-                lfs->seed ^= crc;
+                // pseudorandom numbers, note we use another crc here
+                // as a collection function because it is sufficiently
+                // random and convenient
+                lfs->seed = lfs_crc(lfs->seed, &crc, sizeof(crc));
 
                 // update with what's found so far
                 besttag = tempbesttag;
@@ -848,7 +887,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                 dir->split = tempsplit;
 
                 // reset crc
-                crc = LFS_BLOCK_NULL;
+                crc = 0xffffffff;
                 continue;
             }
 
@@ -959,7 +998,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
         dir->rev = revs[(r+1)%2];
     }
 
-    LFS_ERROR("Corrupted dir pair at %"PRIx32" %"PRIx32,
+    LFS_ERROR("Corrupted dir pair at {0x%"PRIx32", 0x%"PRIx32"}",
             dir->pair[0], dir->pair[1]);
     return LFS_ERR_CORRUPT;
 }
@@ -1227,12 +1266,14 @@ static int lfs_dir_commitattr(lfs_t *lfs, struct lfs_commit *commit,
 
 static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
     // align to program units
-    const lfs_off_t off1 = commit->off + sizeof(lfs_tag_t);
-    const lfs_off_t end = lfs_alignup(off1 + sizeof(uint32_t),
+    const lfs_off_t end = lfs_alignup(commit->off + 2*sizeof(uint32_t),
             lfs->cfg->prog_size);
 
+    lfs_off_t off1 = 0;
+    uint32_t crc1 = 0;
+
     // create crc tags to fill up remainder of commit, note that
-    // padding is not crcd, which lets fetches skip padding but
+    // padding is not crced, which lets fetches skip padding but
     // makes committing a bit more complicated
     while (commit->off < end) {
         lfs_off_t off = commit->off + sizeof(lfs_tag_t);
@@ -1242,7 +1283,7 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
         }
 
         // read erased state from next program unit
-        lfs_tag_t tag = LFS_BLOCK_NULL;
+        lfs_tag_t tag = 0xffffffff;
         int err = lfs_bd_read(lfs,
                 NULL, &lfs->rcache, sizeof(tag),
                 commit->block, noff, &tag, sizeof(tag));
@@ -1266,9 +1307,15 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
             return err;
         }
 
+        // keep track of non-padding checksum to verify
+        if (off1 == 0) {
+            off1 = commit->off + sizeof(uint32_t);
+            crc1 = commit->crc;
+        }
+
         commit->off += sizeof(tag)+lfs_tag_size(tag);
         commit->ptag = tag ^ ((lfs_tag_t)reset << 31);
-        commit->crc = LFS_BLOCK_NULL; // reset crc for next "commit"
+        commit->crc = 0xffffffff; // reset crc for next "commit"
     }
 
     // flush buffers
@@ -1281,8 +1328,14 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
     lfs_off_t off = commit->begin;
     lfs_off_t noff = off1;
     while (off < end) {
-        uint32_t crc = LFS_BLOCK_NULL;
+        uint32_t crc = 0xffffffff;
         for (lfs_off_t i = off; i < noff+sizeof(uint32_t); i++) {
+            // check against written crc, may catch blocks that
+            // become readonly and match our commit size exactly
+            if (i == off1 && crc != crc1) {
+                return LFS_ERR_CORRUPT;
+            }
+
             // leave it up to caching to make this efficient
             uint8_t dat;
             err = lfs_bd_read(lfs,
@@ -1320,6 +1373,9 @@ static int lfs_dir_alloc(lfs_t *lfs, lfs_mdir_t *dir) {
         }
     }
 
+    // zero for reproducability in case initial block is unreadable
+    dir->rev = 0;
+
     // rather than clobbering one of the blocks we just pretend
     // the revision may be valid
     int err = lfs_bd_read(lfs,
@@ -1335,7 +1391,7 @@ static int lfs_dir_alloc(lfs_t *lfs, lfs_mdir_t *dir) {
 
     // set defaults
     dir->off = sizeof(dir->rev);
-    dir->etag = LFS_BLOCK_NULL;
+    dir->etag = 0xffffffff;
     dir->count = 0;
     dir->tail[0] = LFS_BLOCK_NULL;
     dir->tail[1] = LFS_BLOCK_NULL;
@@ -1420,16 +1476,16 @@ static int lfs_dir_compact(lfs_t *lfs,
         lfs_mdir_t *dir, const struct lfs_mattr *attrs, int attrcount,
         lfs_mdir_t *source, uint16_t begin, uint16_t end) {
     // save some state in case block is bad
-    const lfs_block_t oldpair[2] = {dir->pair[1], dir->pair[0]};
+    const lfs_block_t oldpair[2] = {dir->pair[0], dir->pair[1]};
     bool relocated = false;
-    bool exhausted = false;
+    bool tired = false;
 
     // should we split?
     while (end - begin > 1) {
         // find size
         lfs_size_t size = 0;
         int err = lfs_dir_traverse(lfs,
-                source, 0, LFS_BLOCK_NULL, attrs, attrcount,
+                source, 0, 0xffffffff, attrs, attrcount,
                 LFS_MKTAG(0x400, 0x3ff, 0),
                 LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
                 begin, end, -begin,
@@ -1469,8 +1525,14 @@ static int lfs_dir_compact(lfs_t *lfs,
 
     // increment revision count
     dir->rev += 1;
+    // If our revision count == n * block_cycles, we should force a relocation,
+    // this is how littlefs wear-levels at the metadata-pair level. Note that we
+    // actually use (block_cycles+1)|1, this is to avoid two corner cases:
+    // 1. block_cycles = 1, which would prevent relocations from terminating
+    // 2. block_cycles = 2n, which, due to aliasing, would only ever relocate
+    //    one metadata block in the pair, effectively making this useless
     if (lfs->cfg->block_cycles > 0 &&
-            (dir->rev % (lfs->cfg->block_cycles+1) == 0)) {
+            (dir->rev % ((lfs->cfg->block_cycles+1)|1) == 0)) {
         if (lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) == 0) {
             // oh no! we're writing too much to the superblock,
             // should we expand?
@@ -1506,7 +1568,7 @@ static int lfs_dir_compact(lfs_t *lfs,
 #endif
         } else {
             // we're writing too much, time to relocate
-            exhausted = true;
+            tired = true;
             goto relocate;
         }
     }
@@ -1518,8 +1580,8 @@ static int lfs_dir_compact(lfs_t *lfs,
             struct lfs_commit commit = {
                 .block = dir->pair[1],
                 .off = 0,
-                .ptag = LFS_BLOCK_NULL,
-                .crc = LFS_BLOCK_NULL,
+                .ptag = 0xffffffff,
+                .crc = 0xffffffff,
 
                 .begin = 0,
                 .end = lfs->cfg->block_size - 8,
@@ -1548,7 +1610,7 @@ static int lfs_dir_compact(lfs_t *lfs,
 
             // traverse the directory, this time writing out all unique tags
             err = lfs_dir_traverse(lfs,
-                    source, 0, LFS_BLOCK_NULL, attrs, attrcount,
+                    source, 0, 0xffffffff, attrs, attrcount,
                     LFS_MKTAG(0x400, 0x3ff, 0),
                     LFS_MKTAG(LFS_TYPE_NAME, 0, 0),
                     begin, end, -begin,
@@ -1630,29 +1692,31 @@ relocate:
         // commit was corrupted, drop caches and prepare to relocate block
         relocated = true;
         lfs_cache_drop(lfs, &lfs->pcache);
-        if (!exhausted) {
-            LFS_DEBUG("Bad block at %"PRIx32, dir->pair[1]);
+        if (!tired) {
+            LFS_DEBUG("Bad block at 0x%"PRIx32, dir->pair[1]);
         }
 
         // can't relocate superblock, filesystem is now frozen
-        if (lfs_pair_cmp(oldpair, (const lfs_block_t[2]){0, 1}) == 0) {
-            LFS_WARN("Superblock %"PRIx32" has become unwritable", oldpair[1]);
+        if (lfs_pair_cmp(dir->pair, (const lfs_block_t[2]){0, 1}) == 0) {
+            LFS_WARN("Superblock 0x%"PRIx32" has become unwritable",
+                    dir->pair[1]);
             return LFS_ERR_NOSPC;
         }
 
         // relocate half of pair
         int err = lfs_alloc(lfs, &dir->pair[1]);
-        if (err && (err != LFS_ERR_NOSPC || !exhausted)) {
+        if (err && (err != LFS_ERR_NOSPC || !tired)) {
             return err;
         }
 
-        exhausted = false;
+        tired = false;
         continue;
     }
 
     if (relocated) {
         // update references if we relocated
-        LFS_DEBUG("Relocating %"PRIx32" %"PRIx32" -> %"PRIx32" %"PRIx32,
+        LFS_DEBUG("Relocating {0x%"PRIx32", 0x%"PRIx32"} "
+                    "-> {0x%"PRIx32", 0x%"PRIx32"}",
                 oldpair[0], oldpair[1], dir->pair[0], dir->pair[1]);
         int err = lfs_fs_relocate(lfs, oldpair, dir->pair);
         if (err) {
@@ -1684,6 +1748,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
     }
 
     // calculate changes to the directory
+    lfs_mdir_t olddir = *dir;
     bool hasdelete = false;
     for (int i = 0; i < attrcount; i++) {
         if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_CREATE) {
@@ -1705,11 +1770,16 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
         lfs_mdir_t pdir;
         int err = lfs_fs_pred(lfs, dir->pair, &pdir);
         if (err && err != LFS_ERR_NOENT) {
+            *dir = olddir;
             return err;
         }
 
         if (err != LFS_ERR_NOENT && pdir.split) {
-            return lfs_dir_drop(lfs, &pdir, dir);
+            err = lfs_dir_drop(lfs, &pdir, dir);
+            if (err) {
+                *dir = olddir;
+                return err;
+            }
         }
     }
 
@@ -1719,7 +1789,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
             .block = dir->pair[0],
             .off = dir->off,
             .ptag = dir->etag,
-            .crc = LFS_BLOCK_NULL,
+            .crc = 0xffffffff,
 
             .begin = dir->off,
             .end = lfs->cfg->block_size - 8,
@@ -1737,6 +1807,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
             if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
                 goto compact;
             }
+            *dir = olddir;
             return err;
         }
 
@@ -1749,6 +1820,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
         if (!lfs_gstate_iszero(&delta)) {
             err = lfs_dir_getgstate(lfs, dir, &delta);
             if (err) {
+                *dir = olddir;
                 return err;
             }
 
@@ -1760,6 +1832,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
                 if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
                     goto compact;
                 }
+                *dir = olddir;
                 return err;
             }
         }
@@ -1770,6 +1843,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
             if (err == LFS_ERR_NOSPC || err == LFS_ERR_CORRUPT) {
                 goto compact;
             }
+            *dir = olddir;
             return err;
         }
 
@@ -1788,6 +1862,7 @@ compact:
         int err = lfs_dir_compact(lfs, dir, attrs, attrcount,
                 dir, 0, dir->count);
         if (err) {
+            *dir = olddir;
             return err;
         }
     }
@@ -1800,9 +1875,8 @@ compact:
     // we need to copy the pair so they don't get clobbered if we refetch
     // our mdir.
     for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
-        if (&d->m != dir && lfs_pair_cmp(d->m.pair, dir->pair) == 0) {
+        if (&d->m != dir && lfs_pair_cmp(d->m.pair, olddir.pair) == 0) {
             d->m = *dir;
-
             for (int i = 0; i < attrcount; i++) {
                 if (lfs_tag_type3(attrs[i].tag) == LFS_TYPE_DELETE &&
                         d->id == lfs_tag_id(attrs[i].tag)) {
@@ -1825,9 +1899,8 @@ compact:
         }
     }
 
-    lfs_block_t pair[2] = {dir->pair[0], dir->pair[1]};
     for (struct lfs_mlist *d = lfs->mlist; d; d = d->next) {
-        if (lfs_pair_cmp(d->m.pair, pair) == 0) {
+        if (lfs_pair_cmp(d->m.pair, olddir.pair) == 0) {
             while (d->id >= d->m.count && d->m.split) {
                 // we split and id is on tail now
                 d->id -= d->m.count;
@@ -2167,7 +2240,6 @@ static int lfs_ctz_find(lfs_t *lfs,
             return err;
         }
 
-        LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
         current -= 1 << skip;
     }
 
@@ -2187,7 +2259,6 @@ static int lfs_ctz_extend(lfs_t *lfs,
         if (err) {
             return err;
         }
-        LFS_ASSERT(nblock >= 2 && nblock <= lfs->cfg->block_count);
 
         {
             err = lfs_bd_erase(lfs, nblock);
@@ -2204,16 +2275,16 @@ static int lfs_ctz_extend(lfs_t *lfs,
                 return 0;
             }
 
-            size -= 1;
-            lfs_off_t index = lfs_ctz_index(lfs, &size);
-            size += 1;
+            lfs_size_t noff = size - 1;
+            lfs_off_t index = lfs_ctz_index(lfs, &noff);
+            noff = noff + 1;
 
             // just copy out the last block if it is incomplete
-            if (size != lfs->cfg->block_size) {
-                for (lfs_off_t i = 0; i < size; i++) {
+            if (noff != lfs->cfg->block_size) {
+                for (lfs_off_t i = 0; i < noff; i++) {
                     uint8_t data;
                     err = lfs_bd_read(lfs,
-                            NULL, rcache, size-i,
+                            NULL, rcache, noff-i,
                             head, i, &data, 1);
                     if (err) {
                         return err;
@@ -2231,19 +2302,19 @@ static int lfs_ctz_extend(lfs_t *lfs,
                 }
 
                 *block = nblock;
-                *off = size;
+                *off = noff;
                 return 0;
             }
 
             // append block
             index += 1;
             lfs_size_t skips = lfs_ctz(index) + 1;
-
+            lfs_block_t nhead = head;
             for (lfs_off_t i = 0; i < skips; i++) {
-                head = lfs_tole32(head);
+                nhead = lfs_tole32(nhead);
                 err = lfs_bd_prog(lfs, pcache, rcache, true,
-                        nblock, 4*i, &head, 4);
-                head = lfs_fromle32(head);
+                        nblock, 4*i, &nhead, 4);
+                nhead = lfs_fromle32(nhead);
                 if (err) {
                     if (err == LFS_ERR_CORRUPT) {
                         goto relocate;
@@ -2253,15 +2324,13 @@ static int lfs_ctz_extend(lfs_t *lfs,
 
                 if (i != skips-1) {
                     err = lfs_bd_read(lfs,
-                            NULL, rcache, sizeof(head),
-                            head, 4*i, &head, sizeof(head));
-                    head = lfs_fromle32(head);
+                            NULL, rcache, sizeof(nhead),
+                            nhead, 4*i, &nhead, sizeof(nhead));
+                    nhead = lfs_fromle32(nhead);
                     if (err) {
                         return err;
                     }
                 }
-
-                LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
             }
 
             *block = nblock;
@@ -2270,7 +2339,7 @@ static int lfs_ctz_extend(lfs_t *lfs,
         }
 
 relocate:
-        LFS_DEBUG("Bad block at %"PRIx32, nblock);
+        LFS_DEBUG("Bad block at 0x%"PRIx32, nblock);
 
         // just clear cache and try a new block
         lfs_cache_drop(lfs, pcache);
@@ -2374,9 +2443,9 @@ int lfs_file_opencfg(lfs_t *lfs, lfs_file_t *file,
 
         // get next slot and create entry to remember name
         err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
-                {LFS_MKTAG(LFS_TYPE_CREATE, file->id, 0)},
+                {LFS_MKTAG(LFS_TYPE_CREATE, file->id, 0), NULL},
                 {LFS_MKTAG(LFS_TYPE_REG, file->id, nlen), path},
-                {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0)}));
+                {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0), NULL}));
         if (err) {
             err = LFS_ERR_NAMETOOLONG;
             goto cleanup;
@@ -2574,7 +2643,7 @@ static int lfs_file_relocate(lfs_t *lfs, lfs_file_t *file) {
         return 0;
 
 relocate:
-        LFS_DEBUG("Bad block at %"PRIx32, nblock);
+        LFS_DEBUG("Bad block at 0x%"PRIx32, nblock);
 
         // just clear cache and try a new block
         lfs_cache_drop(lfs, &lfs->pcache);
@@ -2651,7 +2720,7 @@ static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
                 break;
 
 relocate:
-                LFS_DEBUG("Bad block at %"PRIx32, file->block);
+                LFS_DEBUG("Bad block at 0x%"PRIx32, file->block);
                 err = lfs_file_relocate(lfs, file);
                 if (err) {
                     return err;
@@ -2677,7 +2746,12 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
     LFS_TRACE("lfs_file_sync(%p, %p)", (void*)lfs, (void*)file);
     LFS_ASSERT(file->flags & LFS_F_OPENED);
 
-    while (true) {
+    if (file->flags & LFS_F_ERRED) {
+        // it's not safe to do anything if our file errored
+        LFS_TRACE("lfs_file_sync -> %d", 0);
+        return 0;
+    }
+
     int err = lfs_file_flush(lfs, file);
     if (err) {
         file->flags |= LFS_F_ERRED;
@@ -2686,7 +2760,6 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
     }
 
     if ((file->flags & LFS_F_DIRTY) &&
-                !(file->flags & LFS_F_ERRED) &&
             !lfs_pair_isnull(file->m.pair)) {
         // update dir entry
         uint16_t type;
@@ -2714,9 +2787,6 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
                 {LFS_MKTAG(LFS_FROM_USERATTRS, file->id,
                     file->cfg->attr_count), file->cfg->attrs}));
         if (err) {
-                if (err == LFS_ERR_NOSPC && (file->flags & LFS_F_INLINE)) {
-                    goto relocate;
-                }
             file->flags |= LFS_F_ERRED;
             LFS_TRACE("lfs_file_sync -> %d", err);
             return err;
@@ -2727,16 +2797,6 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
 
     LFS_TRACE("lfs_file_sync -> %d", 0);
     return 0;
-
-relocate:
-        // inline file doesn't fit anymore
-        err = lfs_file_outline(lfs, file);
-        if (err) {
-            file->flags |= LFS_F_ERRED;
-            LFS_TRACE("lfs_file_sync -> %d", err);
-            return err;
-        }
-    }
 }
 
 lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
@@ -3151,7 +3211,7 @@ int lfs_remove(lfs_t *lfs, const char *path) {
 
     // delete the entry
     err = lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
-            {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(tag), 0)}));
+            {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(tag), 0), NULL}));
     if (err) {
         lfs->mlist = dir.next;
         LFS_TRACE("lfs_remove -> %d", err);
@@ -3277,12 +3337,12 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
     // move over all attributes
     err = lfs_dir_commit(lfs, &newcwd, LFS_MKATTRS(
             {LFS_MKTAG_IF(prevtag != LFS_ERR_NOENT,
-                LFS_TYPE_DELETE, newid, 0)},
-            {LFS_MKTAG(LFS_TYPE_CREATE, newid, 0)},
+                LFS_TYPE_DELETE, newid, 0), NULL},
+            {LFS_MKTAG(LFS_TYPE_CREATE, newid, 0), NULL},
             {LFS_MKTAG(lfs_tag_type3(oldtag), newid, strlen(newpath)), newpath},
             {LFS_MKTAG(LFS_FROM_MOVE, newid, lfs_tag_id(oldtag)), &oldcwd},
             {LFS_MKTAG_IF(samepair,
-                LFS_TYPE_DELETE, newoldid, 0)}));
+                LFS_TYPE_DELETE, newoldid, 0), NULL}));
     if (err) {
         lfs->mlist = prevdir.next;
         LFS_TRACE("lfs_rename -> %d", err);
@@ -3295,7 +3355,7 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
         // prep gstate and delete move id
         lfs_fs_prepmove(lfs, 0x3ff, NULL);
         err = lfs_dir_commit(lfs, &oldcwd, LFS_MKATTRS(
-                {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(oldtag), 0)}));
+                {LFS_MKTAG(LFS_TYPE_DELETE, lfs_tag_id(oldtag), 0), NULL}));
         if (err) {
             lfs->mlist = prevdir.next;
             LFS_TRACE("lfs_rename -> %d", err);
@@ -3428,7 +3488,7 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
     LFS_ASSERT(lfs->cfg->block_size % lfs->cfg->cache_size == 0);
 
     // check that the block size is large enough to fit ctz pointers
-    LFS_ASSERT(4*lfs_npw2(LFS_BLOCK_NULL / (lfs->cfg->block_size-2*4))
+    LFS_ASSERT(4*lfs_npw2(0xffffffff / (lfs->cfg->block_size-2*4))
             <= lfs->cfg->block_size);
 
     // block_cycles = 0 is no longer supported.
@@ -3587,7 +3647,7 @@ int lfs_format(lfs_t *lfs, const struct lfs_config *cfg) {
 
         lfs_superblock_tole32(&superblock);
         err = lfs_dir_commit(lfs, &root, LFS_MKATTRS(
-                {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0)},
+                {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
                 {LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
                 {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
                     &superblock}));
@@ -3641,7 +3701,15 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
 
     // scan directory blocks for superblock and any global updates
     lfs_mdir_t dir = {.tail = {0, 1}};
+    lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(dir.tail)) {
+        if (cycle >= lfs->cfg->block_count/2) {
+            // loop detected
+            err = LFS_ERR_CORRUPT;
+            goto cleanup;
+        }
+        cycle += 1;
+
         // fetch next block in tail list
         lfs_stag_t tag = lfs_dir_fetchmatch(lfs, &dir, dir.tail,
                 LFS_MKTAG(0x7ff, 0x3ff, 0),
@@ -3676,7 +3744,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
             uint16_t minor_version = (0xffff & (superblock.version >>  0));
             if ((major_version != LFS_DISK_VERSION_MAJOR ||
                  minor_version > LFS_DISK_VERSION_MINOR)) {
-                LFS_ERROR("Invalid version %"PRIu16".%"PRIu16,
+                LFS_ERROR("Invalid version v%"PRIu16".%"PRIu16,
                         major_version, minor_version);
                 err = LFS_ERR_INVAL;
                 goto cleanup;
@@ -3732,7 +3800,7 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
 
     // update littlefs with gstate
     if (!lfs_gstate_iszero(&lfs->gstate)) {
-        LFS_DEBUG("Found pending gstate %08"PRIx32" %08"PRIx32" %08"PRIx32,
+        LFS_DEBUG("Found pending gstate 0x%08"PRIx32"%08"PRIx32"%08"PRIx32,
                 lfs->gstate.tag,
                 lfs->gstate.pair[0],
                 lfs->gstate.pair[1]);
@@ -3740,11 +3808,10 @@ int lfs_mount(lfs_t *lfs, const struct lfs_config *cfg) {
     lfs->gstate.tag += !lfs_tag_isvalid(lfs->gstate.tag);
     lfs->gdisk = lfs->gstate;
 
-    // setup free lookahead
-    lfs->free.off = lfs->seed % lfs->cfg->block_size;
-    lfs->free.size = 0;
-    lfs->free.i = 0;
-    lfs_alloc_ack(lfs);
+    // setup free lookahead, to distribute allocations uniformly across
+    // boots, we start the allocator at a random location
+    lfs->free.off = lfs->seed % lfs->cfg->block_count;
+    lfs_alloc_drop(lfs);
 
     LFS_TRACE("lfs_mount -> %d", 0);
     return 0;
@@ -3764,10 +3831,9 @@ int lfs_unmount(lfs_t *lfs) {
 
 
 /// Filesystem filesystem operations ///
-int lfs_fs_traverse(lfs_t *lfs,
-        int (*cb)(void *data, lfs_block_t block), void *data) {
-    LFS_TRACE("lfs_fs_traverse(%p, %p, %p)",
-            (void*)lfs, (void*)(uintptr_t)cb, data);
+int lfs_fs_traverseraw(lfs_t *lfs,
+        int (*cb)(void *data, lfs_block_t block), void *data,
+        bool includeorphans) {
     // iterate over metadata pairs
     lfs_mdir_t dir = {.tail = {0, 1}};
 
@@ -3776,7 +3842,6 @@ int lfs_fs_traverse(lfs_t *lfs,
     if (lfs->lfs1) {
         int err = lfs1_traverse(lfs, cb, data);
         if (err) {
-            LFS_TRACE("lfs_fs_traverse -> %d", err);
             return err;
         }
 
@@ -3785,11 +3850,17 @@ int lfs_fs_traverse(lfs_t *lfs,
     }
 #endif
 
+    lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(dir.tail)) {
+        if (cycle >= lfs->cfg->block_count/2) {
+            // loop detected
+            return LFS_ERR_CORRUPT;
+        }
+        cycle += 1;
+
         for (int i = 0; i < 2; i++) {
             int err = cb(data, dir.tail[i]);
             if (err) {
-                LFS_TRACE("lfs_fs_traverse -> %d", err);
                 return err;
             }
         }
@@ -3797,7 +3868,6 @@ int lfs_fs_traverse(lfs_t *lfs,
         // iterate through ids in directory
         int err = lfs_dir_fetch(lfs, &dir, dir.tail);
         if (err) {
-            LFS_TRACE("lfs_fs_traverse -> %d", err);
             return err;
         }
 
@@ -3809,7 +3879,6 @@ int lfs_fs_traverse(lfs_t *lfs,
                 if (tag == LFS_ERR_NOENT) {
                     continue;
                 }
-                LFS_TRACE("lfs_fs_traverse -> %"PRId32, tag);
                 return tag;
             }
             lfs_ctz_fromle32(&ctz);
@@ -3818,9 +3887,16 @@ int lfs_fs_traverse(lfs_t *lfs,
                 err = lfs_ctz_traverse(lfs, NULL, &lfs->rcache,
                         ctz.head, ctz.size, cb, data);
                 if (err) {
-                    LFS_TRACE("lfs_fs_traverse -> %d", err);
                     return err;
                 }
+            } else if (includeorphans && 
+                    lfs_tag_type3(tag) == LFS_TYPE_DIRSTRUCT) {
+                for (int i = 0; i < 2; i++) {
+                    err = cb(data, (&ctz.head)[i]);
+                    if (err) {
+                        return err;
+                    }
+                }
             }
         }
     }
@@ -3835,7 +3911,6 @@ int lfs_fs_traverse(lfs_t *lfs,
             int err = lfs_ctz_traverse(lfs, &f->cache, &lfs->rcache,
                     f->ctz.head, f->ctz.size, cb, data);
             if (err) {
-                LFS_TRACE("lfs_fs_traverse -> %d", err);
                 return err;
             }
         }
@@ -3844,22 +3919,36 @@ int lfs_fs_traverse(lfs_t *lfs,
             int err = lfs_ctz_traverse(lfs, &f->cache, &lfs->rcache,
                     f->block, f->pos, cb, data);
             if (err) {
-                LFS_TRACE("lfs_fs_traverse -> %d", err);
                 return err;
             }
         }
     }
 
-    LFS_TRACE("lfs_fs_traverse -> %d", 0);
     return 0;
 }
 
+int lfs_fs_traverse(lfs_t *lfs,
+        int (*cb)(void *data, lfs_block_t block), void *data) {
+    LFS_TRACE("lfs_fs_traverse(%p, %p, %p)",
+            (void*)lfs, (void*)(uintptr_t)cb, data);
+    int err = lfs_fs_traverseraw(lfs, cb, data, true);
+    LFS_TRACE("lfs_fs_traverse -> %d", 0);
+    return err;
+}
+
 static int lfs_fs_pred(lfs_t *lfs,
         const lfs_block_t pair[2], lfs_mdir_t *pdir) {
     // iterate over all directory directory entries
     pdir->tail[0] = 0;
     pdir->tail[1] = 1;
+    lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(pdir->tail)) {
+        if (cycle >= lfs->cfg->block_count/2) {
+            // loop detected
+            return LFS_ERR_CORRUPT;
+        }
+        cycle += 1;
+
         if (lfs_pair_cmp(pdir->tail, pair) == 0) {
             return 0;
         }
@@ -3902,7 +3991,14 @@ static lfs_stag_t lfs_fs_parent(lfs_t *lfs, const lfs_block_t pair[2],
     // use fetchmatch with callback to find pairs
     parent->tail[0] = 0;
     parent->tail[1] = 1;
+    lfs_block_t cycle = 0;
     while (!lfs_pair_isnull(parent->tail)) {
+        if (cycle >= lfs->cfg->block_count/2) {
+            // loop detected
+            return LFS_ERR_CORRUPT;
+        }
+        cycle += 1;
+
         lfs_stag_t tag = lfs_dir_fetchmatch(lfs, parent, parent->tail,
                 LFS_MKTAG(0x7ff, 0, 0x3ff),
                 LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 0, 8),
@@ -3921,8 +4017,6 @@ static int lfs_fs_relocate(lfs_t *lfs,
         const lfs_block_t oldpair[2], lfs_block_t newpair[2]) {
     // update internal root
     if (lfs_pair_cmp(oldpair, lfs->root) == 0) {
-        LFS_DEBUG("Relocating root %"PRIx32" %"PRIx32,
-                newpair[0], newpair[1]);
         lfs->root[0] = newpair[0];
         lfs->root[1] = newpair[1];
     }
@@ -3958,7 +4052,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         if (lfs_gstate_hasmovehere(&lfs->gstate, parent.pair)) {
             moveid = lfs_tag_id(lfs->gstate.tag);
             LFS_DEBUG("Fixing move while relocating "
-                    "%"PRIx32" %"PRIx32" %"PRIx16"\n",
+                    "{0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16"\n",
                     parent.pair[0], parent.pair[1], moveid);
             lfs_fs_prepmove(lfs, 0x3ff, NULL);
             if (moveid < lfs_tag_id(tag)) {
@@ -3969,7 +4063,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         lfs_pair_tole32(newpair);
         int err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
                 {LFS_MKTAG_IF(moveid != 0x3ff,
-                    LFS_TYPE_DELETE, moveid, 0)},
+                    LFS_TYPE_DELETE, moveid, 0), NULL},
                 {tag, newpair}));
         lfs_pair_fromle32(newpair);
         if (err) {
@@ -3994,7 +4088,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         if (lfs_gstate_hasmovehere(&lfs->gstate, parent.pair)) {
             moveid = lfs_tag_id(lfs->gstate.tag);
             LFS_DEBUG("Fixing move while relocating "
-                    "%"PRIx32" %"PRIx32" %"PRIx16"\n",
+                    "{0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16"\n",
                     parent.pair[0], parent.pair[1], moveid);
             lfs_fs_prepmove(lfs, 0x3ff, NULL);
         }
@@ -4003,7 +4097,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         lfs_pair_tole32(newpair);
         err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
                 {LFS_MKTAG_IF(moveid != 0x3ff,
-                    LFS_TYPE_DELETE, moveid, 0)},
+                    LFS_TYPE_DELETE, moveid, 0), NULL},
                 {LFS_MKTAG(LFS_TYPE_TAIL + parent.split, 0x3ff, 8), newpair}));
         lfs_pair_fromle32(newpair);
         if (err) {
@@ -4035,7 +4129,7 @@ static int lfs_fs_demove(lfs_t *lfs) {
     }
 
     // Fix bad moves
-    LFS_DEBUG("Fixing move %"PRIx32" %"PRIx32" %"PRIx16,
+    LFS_DEBUG("Fixing move {0x%"PRIx32", 0x%"PRIx32"} 0x%"PRIx16,
             lfs->gdisk.pair[0],
             lfs->gdisk.pair[1],
             lfs_tag_id(lfs->gdisk.tag));
@@ -4051,7 +4145,7 @@ static int lfs_fs_demove(lfs_t *lfs) {
     uint16_t moveid = lfs_tag_id(lfs->gdisk.tag);
     lfs_fs_prepmove(lfs, 0x3ff, NULL);
     err = lfs_dir_commit(lfs, &movedir, LFS_MKATTRS(
-            {LFS_MKTAG(LFS_TYPE_DELETE, moveid, 0)}));
+            {LFS_MKTAG(LFS_TYPE_DELETE, moveid, 0), NULL}));
     if (err) {
         return err;
     }
@@ -4086,7 +4180,7 @@ static int lfs_fs_deorphan(lfs_t *lfs) {
 
             if (tag == LFS_ERR_NOENT) {
                 // we are an orphan
-                LFS_DEBUG("Fixing orphan %"PRIx32" %"PRIx32,
+                LFS_DEBUG("Fixing orphan {0x%"PRIx32", 0x%"PRIx32"}",
                         pdir.tail[0], pdir.tail[1]);
 
                 err = lfs_dir_drop(lfs, &pdir, &dir);
@@ -4108,8 +4202,8 @@ static int lfs_fs_deorphan(lfs_t *lfs) {
 
             if (!lfs_pair_sync(pair, pdir.tail)) {
                 // we have desynced
-                LFS_DEBUG("Fixing half-orphan "
-                        "%"PRIx32" %"PRIx32" -> %"PRIx32" %"PRIx32,
+                LFS_DEBUG("Fixing half-orphan {0x%"PRIx32", 0x%"PRIx32"} "
+                            "-> {0x%"PRIx32", 0x%"PRIx32"}",
                         pdir.tail[0], pdir.tail[1], pair[0], pair[1]);
 
                 lfs_pair_tole32(pair);
@@ -4157,7 +4251,7 @@ static int lfs_fs_size_count(void *p, lfs_block_t block) {
 lfs_ssize_t lfs_fs_size(lfs_t *lfs) {
     LFS_TRACE("lfs_fs_size(%p)", (void*)lfs);
     lfs_size_t size = 0;
-    int err = lfs_fs_traverse(lfs, lfs_fs_size_count, &size);
+    int err = lfs_fs_traverseraw(lfs, lfs_fs_size_count, &size, false);
     if (err) {
         LFS_TRACE("lfs_fs_size -> %d", err);
         return err;
@@ -4345,7 +4439,7 @@ static int lfs1_dir_fetch(lfs_t *lfs,
             continue;
         }
 
-        uint32_t crc = LFS_BLOCK_NULL;
+        uint32_t crc = 0xffffffff;
         lfs1_dir_tole32(&test);
         lfs1_crc(&crc, &test, sizeof(test));
         lfs1_dir_fromle32(&test);
@@ -4372,7 +4466,7 @@ static int lfs1_dir_fetch(lfs_t *lfs,
     }
 
     if (!valid) {
-        LFS_ERROR("Corrupted dir pair at %" PRIx32 " %" PRIx32 ,
+        LFS_ERROR("Corrupted dir pair at {0x%"PRIx32", 0x%"PRIx32"}",
                 tpair[0], tpair[1]);
         return LFS_ERR_CORRUPT;
     }
@@ -4560,7 +4654,8 @@ static int lfs1_mount(lfs_t *lfs, struct lfs1 *lfs1,
         }
 
         if (err || memcmp(superblock.d.magic, "littlefs", 8) != 0) {
-            LFS_ERROR("Invalid superblock at %d %d", 0, 1);
+            LFS_ERROR("Invalid superblock at {0x%"PRIx32", 0x%"PRIx32"}",
+                    0, 1);
             err = LFS_ERR_CORRUPT;
             goto cleanup;
         }
@@ -4569,7 +4664,7 @@ static int lfs1_mount(lfs_t *lfs, struct lfs1 *lfs1,
         uint16_t minor_version = (0xffff & (superblock.d.version >>  0));
         if ((major_version != LFS1_DISK_VERSION_MAJOR ||
              minor_version > LFS1_DISK_VERSION_MINOR)) {
-            LFS_ERROR("Invalid version %d.%d", major_version, minor_version);
+            LFS_ERROR("Invalid version v%d.%d", major_version, minor_version);
             err = LFS_ERR_INVAL;
             goto cleanup;
         }
@@ -4735,7 +4830,8 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
             // Copy over first block to thread into fs. Unfortunately
             // if this fails there is not much we can do.
-            LFS_DEBUG("Migrating %"PRIx32" %"PRIx32" -> %"PRIx32" %"PRIx32,
+            LFS_DEBUG("Migrating {0x%"PRIx32", 0x%"PRIx32"} "
+                        "-> {0x%"PRIx32", 0x%"PRIx32"}",
                     lfs->root[0], lfs->root[1], dir1.head[0], dir1.head[1]);
 
             err = lfs_bd_erase(lfs, dir1.head[1]);
@@ -4781,7 +4877,7 @@ int lfs_migrate(lfs_t *lfs, const struct lfs_config *cfg) {
         dir2.pair[1] = dir1.pair[1];
         dir2.rev = dir1.d.rev;
         dir2.off = sizeof(dir2.rev);
-        dir2.etag = LFS_BLOCK_NULL;
+        dir2.etag = 0xffffffff;
         dir2.count = 0;
         dir2.tail[0] = lfs->lfs1->root[0];
         dir2.tail[1] = lfs->lfs1->root[1];

lfs.h

@@ -21,7 +21,7 @@ extern "C"
 // Software library version
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_VERSION 0x00020001
+#define LFS_VERSION 0x00020002
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 

lfs_util.h

@@ -50,31 +50,35 @@ extern "C"
 
 // Logging functions
 #ifdef LFS_YES_TRACE
-#define LFS_TRACE(fmt, ...) \
-    printf("%s:%d:trace: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_TRACE_(fmt, ...) \
+    printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
 #else
-#define LFS_TRACE(fmt, ...)
+#define LFS_TRACE(...)
 #endif
 
 #ifndef LFS_NO_DEBUG
-#define LFS_DEBUG(fmt, ...) \
-    printf("%s:%d:debug: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_DEBUG_(fmt, ...) \
+    printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_DEBUG(...) LFS_DEBUG_(__VA_ARGS__, "")
 #else
-#define LFS_DEBUG(fmt, ...)
+#define LFS_DEBUG(...)
 #endif
 
 #ifndef LFS_NO_WARN
-#define LFS_WARN(fmt, ...) \
-    printf("%s:%d:warn: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_WARN_(fmt, ...) \
+    printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_WARN(...) LFS_WARN_(__VA_ARGS__, "")
 #else
-#define LFS_WARN(fmt, ...)
+#define LFS_WARN(...)
 #endif
 
 #ifndef LFS_NO_ERROR
-#define LFS_ERROR(fmt, ...) \
-    printf("%s:%d:error: " fmt "\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_ERROR_(fmt, ...) \
+    printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
+#define LFS_ERROR(...) LFS_ERROR_(__VA_ARGS__, "")
 #else
-#define LFS_ERROR(fmt, ...)
+#define LFS_ERROR(...)
 #endif
 
 // Runtime assertions
@@ -107,7 +111,7 @@ static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment) {
     return lfs_aligndown(a + alignment-1, alignment);
 }
 
-// Find the next smallest power of 2 less than or equal to a
+// Find the smallest power of 2 greater than or equal to a
 static inline uint32_t lfs_npw2(uint32_t a) {
 #if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
     return 32 - __builtin_clz(a-1);

scripts/explode_asserts.py

@@ -166,8 +166,8 @@ def mkassert(type, comp, lh, rh, size=None):
         'type': type.lower(), 'TYPE': type.upper(),
         'comp': comp.lower(), 'COMP': comp.upper(),
         'prefix': PREFIX.lower(), 'PREFIX': PREFIX.upper(),
-        'lh': lh.strip(),
-        'rh': rh.strip(),
+        'lh': lh.strip(' '),
+        'rh': rh.strip(' '),
         'size': size,
     }
     if size:

scripts/readmdir.py

@@ -2,6 +2,7 @@
 
 import struct
 import binascii
+import sys
 import itertools as it
 
 TAG_TYPES = {
@@ -232,8 +233,8 @@ class MetadataPair:
 
     def __lt__(self, other):
         # corrupt blocks don't count
-        if not self and other:
-            return True
+        if not self or not other:
+            return bool(other)
 
         # use sequence arithmetic to avoid overflow
         return not ((other.rev - self.rev) & 0x80000000)
@@ -271,37 +272,39 @@ class MetadataPair:
 
         raise KeyError(gmask, gtag)
 
-    def _dump_tags(self, tags, truncate=True):
-        sys.stdout.write("%-8s  %-8s  %-13s %4s %4s  %s\n" % (
-            'off', 'tag', 'type', 'id', 'len',
-            'data (truncated)' if truncate else 12*' '+'data'))
+    def _dump_tags(self, tags, f=sys.stdout, truncate=True):
+        f.write("%-8s  %-8s  %-13s %4s %4s" % (
+            'off', 'tag', 'type', 'id', 'len'))
+        if truncate:
+            f.write('  data (truncated)')
+        f.write('\n')
 
         for tag in tags:
-            sys.stdout.write("%08x: %08x  %-13s %4s %4s" % (
+            f.write("%08x: %08x  %-13s %4s %4s" % (
                 tag.off, tag,
                 tag.typerepr(), tag.idrepr(), tag.sizerepr()))
             if truncate:
-                sys.stdout.write("  %-23s  %-8s\n" % (
+                f.write("  %-23s  %-8s\n" % (
                     ' '.join('%02x' % c for c in tag.data[:8]),
                     ''.join(c if c >= ' ' and c <= '~' else '.'
                         for c in map(chr, tag.data[:8]))))
             else:
-                sys.stdout.write("\n")
+                f.write("\n")
                 for i in range(0, len(tag.data), 16):
-                    sys.stdout.write("%08x: %-47s  %-16s\n" % (
+                    f.write("  %08x: %-47s  %-16s\n" % (
                         tag.off+i,
                         ' '.join('%02x' % c for c in tag.data[i:i+16]),
                         ''.join(c if c >= ' ' and c <= '~' else '.'
                             for c in map(chr, tag.data[i:i+16]))))
 
-    def dump_tags(self, truncate=True):
-        self._dump_tags(self.tags, truncate=truncate)
+    def dump_tags(self, f=sys.stdout, truncate=True):
+        self._dump_tags(self.tags, f=f, truncate=truncate)
 
-    def dump_log(self, truncate=True):
-        self._dump_tags(self.log, truncate=truncate)
+    def dump_log(self, f=sys.stdout, truncate=True):
+        self._dump_tags(self.log, f=f, truncate=truncate)
 
-    def dump_all(self, truncate=True):
-        self._dump_tags(self.all_, truncate=truncate)
+    def dump_all(self, f=sys.stdout, truncate=True):
+        self._dump_tags(self.all_, f=f, truncate=truncate)
 
 def main(args):
     blocks = []
@@ -315,6 +318,24 @@ def main(args):
 
     # find most recent pair
     mdir = MetadataPair(blocks)
+
+    try:
+        mdir.tail = mdir[Tag('tail', 0, 0)]
+        if mdir.tail.size != 8 or mdir.tail.data == 8*b'\xff':
+            mdir.tail = None
+    except KeyError:
+        mdir.tail = None
+
+    print("mdir {%s} rev %d%s%s%s" % (
+        ', '.join('%#x' % b
+            for b in [args.block1, args.block2]
+            if b is not None),
+        mdir.rev,
+        ' (was %s)' % ', '.join('%d' % m.rev for m in mdir.pair[1:])
+        if len(mdir.pair) > 1 else '',
+        ' (corrupted!)' if not mdir else '',
+        ' -> {%#x, %#x}' % struct.unpack('<II', mdir.tail.data)
+        if mdir.tail else ''))
     if args.all:
         mdir.dump_all(truncate=not args.no_truncate)
     elif args.log:
@@ -337,10 +358,10 @@ if __name__ == "__main__":
         help="First block address for finding the metadata pair.")
     parser.add_argument('block2', nargs='?', type=lambda x: int(x, 0),
         help="Second block address for finding the metadata pair.")
-    parser.add_argument('-a', '--all', action='store_true',
-        help="Show all tags in log, included tags in corrupted commits.")
     parser.add_argument('-l', '--log', action='store_true',
         help="Show tags in log.")
+    parser.add_argument('-a', '--all', action='store_true',
+        help="Show all tags in log, included tags in corrupted commits.")
     parser.add_argument('-T', '--no-truncate', action='store_true',
-        help="Don't truncate large amounts of data in tags.")
+        help="Don't truncate large amounts of data.")
     sys.exit(main(parser.parse_args()))

scripts/readtree.py

@@ -7,120 +7,24 @@ import io
 import itertools as it
 from readmdir import Tag, MetadataPair
 
-def popc(x):
-    return bin(x).count('1')
-
-def ctz(x):
-    return len(bin(x)) - len(bin(x).rstrip('0'))
-
-def dumptags(args, mdir, f):
-    if args.all:
-        tags = mdir.all_
-    elif args.log:
-        tags = mdir.log
-    else:
-        tags = mdir.tags
-
-    for k, tag in enumerate(tags):
-        f.write("tag %08x %s" % (tag, tag.typerepr()))
-        if tag.id != 0x3ff:
-            f.write(" id %d" % tag.id)
-        if tag.size != 0x3ff:
-            f.write(" size %d" % tag.size)
-        if tag.is_('name'):
-            f.write(" name %s" %
-                json.dumps(tag.data.decode('utf8')))
-        if tag.is_('dirstruct'):
-            f.write(" dir {%#x, %#x}" % struct.unpack(
-                '<II', tag.data[:8].ljust(8, b'\xff')))
-        if tag.is_('ctzstruct'):
-            f.write(" ctz {%#x} size %d" % struct.unpack(
-                '<II', tag.data[:8].ljust(8, b'\xff')))
-        if tag.is_('inlinestruct'):
-            f.write(" inline size %d" % tag.size)
-        if tag.is_('gstate'):
-            f.write(" 0x%s" % ''.join('%02x' % c for c in tag.data))
-        if tag.is_('tail'):
-            f.write(" tail {%#x, %#x}" % struct.unpack(
-                '<II', tag.data[:8].ljust(8, b'\xff')))
-        f.write("\n")
-
-        if args.data:
-            for i in range(0, len(tag.data), 16):
-                f.write("  %-47s  %-16s\n" % (
-                    ' '.join('%02x' % c for c in tag.data[i:i+16]),
-                    ''.join(c if c >= ' ' and c <= '~' else '.'
-                        for c in map(chr, tag.data[i:i+16]))))
-
-def dumpentries(args, mdir, f):
-    for k, id_ in enumerate(mdir.ids):
-        name = mdir[Tag('name', id_, 0)]
-        struct_ = mdir[Tag('struct', id_, 0)]
-
-        f.write("id %d %s %s" % (
-            id_, name.typerepr(),
-            json.dumps(name.data.decode('utf8'))))
-        if struct_.is_('dirstruct'):
-            f.write(" dir {%#x, %#x}" % struct.unpack(
-                '<II', struct_.data[:8].ljust(8, b'\xff')))
-        if struct_.is_('ctzstruct'):
-            f.write(" ctz {%#x} size %d" % struct.unpack(
-                '<II', struct_.data[:8].ljust(8, b'\xff')))
-        if struct_.is_('inlinestruct'):
-            f.write(" inline size %d" % struct_.size)
-        f.write("\n")
-
-        if args.data and struct_.is_('inlinestruct'):
-            for i in range(0, len(struct_.data), 16):
-                f.write("  %-47s  %-16s\n" % (
-                    ' '.join('%02x' % c for c in struct_.data[i:i+16]),
-                    ''.join(c if c >= ' ' and c <= '~' else '.'
-                        for c in map(chr, struct_.data[i:i+16]))))
-        elif args.data and struct_.is_('ctzstruct'):
-            block, size = struct.unpack(
-                '<II', struct_.data[:8].ljust(8, b'\xff'))
-            data = []
-            i = 0 if size == 0 else (size-1) // (args.block_size - 8)
-            if i != 0:
-                i = ((size-1) - 4*popc(i-1)+2) // (args.block_size - 8)
-            with open(args.disk, 'rb') as f2:
-                while i >= 0:
-                    f2.seek(block * args.block_size)
-                    dat = f2.read(args.block_size)
-                    data.append(dat[4*(ctz(i)+1) if i != 0 else 0:])
-                    block, = struct.unpack('<I', dat[:4].ljust(4, b'\xff'))
-                    i -= 1
-
-            data = bytes(it.islice(
-                it.chain.from_iterable(reversed(data)), size))
-            for i in range(0, min(len(data), 256)
-                    if not args.no_truncate else len(data), 16):
-                f.write("  %-47s  %-16s\n" % (
-                    ' '.join('%02x' % c for c in data[i:i+16]),
-                    ''.join(c if c >= ' ' and c <= '~' else '.'
-                        for c in map(chr, data[i:i+16]))))
-
-        for tag in mdir.tags:
-            if tag.id==id_ and tag.is_('userattr'):
-                f.write("id %d %s size %d\n" % (
-                    id_, tag.typerepr(), tag.size))
-
-                if args.data:
-                    for i in range(0, len(tag.data), 16):
-                        f.write("  %-47s  %-16s\n" % (
-                            ' '.join('%02x' % c for c in tag.data[i:i+16]),
-                            ''.join(c if c >= ' ' and c <= '~' else '.'
-                                for c in map(chr, tag.data[i:i+16]))))
-
 def main(args):
-    with open(args.disk, 'rb') as f:
-        dirs = []
     superblock = None
-        gstate = b''
+    gstate = b'\0\0\0\0\0\0\0\0\0\0\0\0'
+    dirs = []
     mdirs = []
+    corrupted = []
+    cycle = False
+    with open(args.disk, 'rb') as f:
         tail = (args.block1, args.block2)
         hard = False
         while True:
+            for m in it.chain((m for d in dirs for m in d), mdirs):
+                if set(m.blocks) == set(tail):
+                    # cycle detected
+                    cycle = m.blocks
+            if cycle:
+                break
+
             # load mdir
             data = []
             blocks = {}
@@ -129,6 +33,7 @@ def main(args):
                 data.append(f.read(args.block_size)
                     .ljust(args.block_size, b'\xff'))
                 blocks[id(data[-1])] = block
+
             mdir = MetadataPair(data)
             mdir.blocks = tuple(blocks[id(p.data)] for p in mdir.pair)
 
@@ -156,6 +61,10 @@ def main(args):
             except KeyError:
                 pass
 
+            # corrupted?
+            if not mdir:
+                corrupted.append(mdir)
+
             # add to directories
             mdirs.append(mdir)
             if mdir.tail is None or not mdir.tail.is_('hardtail'):
@@ -171,7 +80,7 @@ def main(args):
     # find paths
     dirtable = {}
     for dir in dirs:
-        dirtable[tuple(sorted(dir[0].blocks))] = dir
+        dirtable[frozenset(dir[0].blocks)] = dir
 
     pending = [("/", dirs[0])]
     while pending:
@@ -183,57 +92,51 @@ def main(args):
                         npath = tag.data.decode('utf8')
                         dirstruct = mdir[Tag('dirstruct', tag.id, 0)]
                         nblocks = struct.unpack('<II', dirstruct.data)
-                        nmdir = dirtable[tuple(sorted(nblocks))]
+                        nmdir = dirtable[frozenset(nblocks)]
                         pending.append(((path + '/' + npath), nmdir))
                     except KeyError:
                         pass
 
         dir[0].path = path.replace('//', '/')
 
-    # dump tree
-    if not args.superblock and not args.gstate and not args.mdirs:
-        args.superblock = True
-        args.gstate = True
-        args.mdirs = True
+    # print littlefs + version info
+    version = ('?', '?')
+    if superblock:
+        version = tuple(reversed(
+            struct.unpack('<HH', superblock[1].data[0:4].ljust(4, b'\xff'))))
+    print("%-47s%s" % ("littlefs v%s.%s" % version,
+        "data (truncated, if it fits)"
+        if not any([args.no_truncate, args.log, args.all]) else ""))
 
-    if args.superblock and superblock:
-        print("superblock %s v%d.%d" % (
-            json.dumps(superblock[0].data.decode('utf8')),
-            struct.unpack('<H', superblock[1].data[2:2+2])[0],
-            struct.unpack('<H', superblock[1].data[0:0+2])[0]))
-        print(
-            "  block_size %d\n"
-            "  block_count %d\n"
-            "  name_max %d\n"
-            "  file_max %d\n"
-            "  attr_max %d" % struct.unpack(
-                '<IIIII', superblock[1].data[4:4+20].ljust(20, b'\xff')))
-
-    if args.gstate and gstate:
+    # print gstate
     print("gstate 0x%s" % ''.join('%02x' % c for c in gstate))
     tag = Tag(struct.unpack('<I', gstate[0:4].ljust(4, b'\xff'))[0])
     blocks = struct.unpack('<II', gstate[4:4+8].ljust(8, b'\xff'))
-        if tag.size:
-            print("  orphans %d" % tag.size)
+    if tag.size or not tag.isvalid:
+        print("  orphans >=%d" % max(tag.size, 1))
     if tag.type:
         print("  move dir {%#x, %#x} id %d" % (
             blocks[0], blocks[1], tag.id))
 
-    if args.mdirs:
+    # print mdir info
     for i, dir in enumerate(dirs):
         print("dir %s" % (json.dumps(dir[0].path)
             if hasattr(dir[0], 'path') else '(orphan)'))
 
         for j, mdir in enumerate(dir):
-                print("mdir {%#x, %#x} rev %d%s" % (
-                    mdir.blocks[0], mdir.blocks[1], mdir.rev,
-                    ' (corrupted)' if not mdir else ''))
+            print("mdir {%#x, %#x} rev %d (was %d)%s%s" % (
+                mdir.blocks[0], mdir.blocks[1], mdir.rev, mdir.pair[1].rev,
+                ' (corrupted!)' if not mdir else '',
+                ' -> {%#x, %#x}' % struct.unpack('<II', mdir.tail.data)
+                if mdir.tail else ''))
 
             f = io.StringIO()
-                if args.tags or args.all or args.log:
-                    dumptags(args, mdir, f)
+            if args.log:
+                mdir.dump_log(f, truncate=not args.no_truncate)
+            elif args.all:
+                mdir.dump_all(f, truncate=not args.no_truncate)
             else:
-                    dumpentries(args, mdir, f)
+                mdir.dump_tags(f, truncate=not args.no_truncate)
 
             lines = list(filter(None, f.getvalue().split('\n')))
             for k, line in enumerate(lines):
@@ -243,7 +146,18 @@ def main(args):
                     '|',
                     line))
 
-    return 0 if all(mdir for dir in dirs for mdir in dir) else 1
+    errcode = 0
+    for mdir in corrupted:
+        errcode = errcode or 1
+        print("*** corrupted mdir {%#x, %#x}! ***" % (
+            mdir.blocks[0], mdir.blocks[1]))
+
+    if cycle:
+        errcode = errcode or 2
+        print("*** cycle detected {%#x, %#x}! ***" % (
+            cycle[0], cycle[1]))
+
+    return errcode
 
 if __name__ == "__main__":
     import argparse
@@ -256,24 +170,14 @@ if __name__ == "__main__":
         help="Size of a block in bytes.")
     parser.add_argument('block1', nargs='?', default=0,
         type=lambda x: int(x, 0),
-        help="Optional first block address for finding the root.")
+        help="Optional first block address for finding the superblock.")
     parser.add_argument('block2', nargs='?', default=1,
         type=lambda x: int(x, 0),
-        help="Optional second block address for finding the root.")
-    parser.add_argument('-s', '--superblock', action='store_true',
-        help="Show contents of the superblock.")
-    parser.add_argument('-g', '--gstate', action='store_true',
-        help="Show contents of global-state.")
-    parser.add_argument('-m', '--mdirs', action='store_true',
-        help="Show contents of metadata-pairs/directories.")
-    parser.add_argument('-t', '--tags', action='store_true',
-        help="Show metadata tags instead of reconstructing entries.")
-    parser.add_argument('-a', '--all', action='store_true',
-        help="Show all tags in log, included tags in corrupted commits.")
+        help="Optional second block address for finding the superblock.")
     parser.add_argument('-l', '--log', action='store_true',
         help="Show tags in log.")
-    parser.add_argument('-d', '--data', action='store_true',
-        help="Also show the raw contents of files/attrs/tags.")
+    parser.add_argument('-a', '--all', action='store_true',
+        help="Show all tags in log, included tags in corrupted commits.")
     parser.add_argument('-T', '--no-truncate', action='store_true',
-        help="Don't truncate large amounts of data in files.")
+        help="Show the full contents of files/attrs/tags.")
     sys.exit(main(parser.parse_args()))

scripts/test.py

@@ -52,7 +52,7 @@ DEFINES = {
     'LFS_LOOKAHEAD_SIZE': 16,
     'LFS_ERASE_VALUE': 0xff,
     'LFS_ERASE_CYCLES': 0,
-    'LFS_BADBLOCK_BEHAVIOR': 'LFS_TESTBD_BADBLOCK_NOPROG',
+    'LFS_BADBLOCK_BEHAVIOR': 'LFS_TESTBD_BADBLOCK_PROGERROR',
 }
 PROLOGUE = """
     // prologue
@@ -182,27 +182,43 @@ class TestCase:
         elif args.get('no_internal', False) and self.in_ is not None:
             return False
         elif self.if_ is not None:
-            return eval(self.if_, None, self.defines.copy())
+            if_ = self.if_
+            while True:
+                for k, v in sorted(self.defines.items(),
+                        key=lambda x: len(x[0]), reverse=True):
+                    if k in if_:
+                        if_ = if_.replace(k, '(%s)' % v)
+                        break
+                else:
+                    break
+            if_ = (
+                re.sub('(\&\&|\?)', ' and ',
+                re.sub('(\|\||:)', ' or ',
+                re.sub('!(?!=)', ' not ', if_))))
+            return eval(if_)
         else:
             return True
 
     def test(self, exec=[], persist=False, cycles=None,
-            gdb=False, failure=None, **args):
+            gdb=False, failure=None, disk=None, **args):
         # build command
         cmd = exec + ['./%s.test' % self.suite.path,
             repr(self.caseno), repr(self.permno)]
 
         # persist disk or keep in RAM for speed?
         if persist:
+            if not disk:
+                disk = self.suite.path + '.disk'
             if persist != 'noerase':
                 try:
-                    os.remove(self.suite.path + '.disk')
+                    with open(disk, 'w') as f:
+                        f.truncate(0)
                     if args.get('verbose', False):
-                        print('rm', self.suite.path + '.disk')
+                        print('truncate --size=0', disk)
                 except FileNotFoundError:
                     pass
 
-            cmd.append(self.suite.path + '.disk')
+            cmd.append(disk)
 
         # simulate power-loss after n cycles?
         if cycles:
@@ -215,7 +231,7 @@ class TestCase:
                 ncmd.extend(['-ex', 'r'])
                 if failure.assert_:
                     ncmd.extend(['-ex', 'up 2'])
-            elif gdb == 'start':
+            elif gdb == 'main':
                 ncmd.extend([
                     '-ex', 'b %s:%d' % (self.suite.path, self.code_lineno),
                     '-ex', 'r'])
@@ -235,6 +251,7 @@ class TestCase:
         mpty = os.fdopen(mpty, 'r', 1)
         stdout = []
         assert_ = None
+        try:
             while True:
                 try:
                     line = mpty.readline()
@@ -254,7 +271,8 @@ class TestCase:
                     try:
                         with open(m.group(1)) as f:
                             lineno = int(m.group(2))
-                        line = next(it.islice(f, lineno-1, None)).strip('\n')
+                            line = (next(it.islice(f, lineno-1, None))
+                                .strip('\n'))
                         assert_ = {
                             'path': m.group(1),
                             'line': line,
@@ -262,6 +280,8 @@ class TestCase:
                             'message': m.group(3)}
                     except:
                         pass
+        except KeyboardInterrupt:
+            raise TestFailure(self, 1, stdout, None)
         proc.wait()
 
         # did we pass?
@@ -279,11 +299,17 @@ class ValgrindTestCase(TestCase):
         return not self.leaky and super().shouldtest(**args)
 
     def test(self, exec=[], **args):
-        exec = exec + [
+        verbose = args.get('verbose', False)
+        uninit = (self.defines.get('LFS_ERASE_VALUE', None) == -1)
+        exec = [
             'valgrind',
             '--leak-check=full',
+            ] + (['--undef-value-errors=no'] if uninit else []) + [
+            ] + (['--track-origins=yes'] if not uninit else []) + [
             '--error-exitcode=4',
-            '-q']
+            '--error-limit=no',
+            ] + (['--num-callers=1'] if not verbose else []) + [
+            '-q'] + exec
         return super().test(exec=exec, **args)
 
 class ReentrantTestCase(TestCase):
@@ -294,7 +320,7 @@ class ReentrantTestCase(TestCase):
     def shouldtest(self, **args):
         return self.reentrant and super().shouldtest(**args)
 
-    def test(self, exec=[], persist=False, gdb=False, failure=None, **args):
+    def test(self, persist=False, gdb=False, failure=None, **args):
         for cycles in it.count(1):
             # clear disk first?
             if cycles == 1 and persist != 'noerase':
@@ -360,10 +386,11 @@ class TestSuite:
             # code lineno?
             if 'code' in case:
                 case['code_lineno'] = code_linenos.pop()
-            # give our case's config a copy of our "global" config
-            for k, v in config.items():
-                if k not in case:
-                    case[k] = v
+            # merge conditions if necessary
+            if 'if' in config and 'if' in case:
+                case['if'] = '(%s) && (%s)' % (config['if'], case['if'])
+            elif 'if' in config:
+                case['if'] = config['if']
             # initialize test case
             self.cases.append(TestCase(case, filter=filter,
                 suite=self, caseno=i+1, lineno=lineno, **args))
@@ -654,6 +681,10 @@ def main(**args):
     if filtered != sum(len(suite.perms) for suite in suites):
         print('filtered down to %d permutations' % filtered)
 
+    # only requested to build?
+    if args.get('build', False):
+        return 0
+
     print('====== testing ======')
     try:
         for suite in suites:
@@ -678,18 +709,17 @@ def main(**args):
                         perm=perm, path=perm.suite.path, lineno=perm.lineno,
                         returncode=perm.result.returncode or 0))
                 if perm.result.stdout:
-                    for line in (perm.result.stdout
-                            if not perm.result.assert_
-                            else perm.result.stdout[:-1]):
+                    if perm.result.assert_:
+                        stdout = perm.result.stdout[:-1]
+                    else:
+                        stdout = perm.result.stdout
+                    for line in stdout[-5:]:
                         sys.stdout.write(line)
                 if perm.result.assert_:
                     sys.stdout.write(
                         "\033[01m{path}:{lineno}:\033[01;31massert:\033[m "
                         "{message}\n{line}\n".format(
                             **perm.result.assert_))
-                else:
-                    for line in perm.result.stdout:
-                        sys.stdout.write(line)
                 sys.stdout.write('\n')
                 failed += 1
 
@@ -728,7 +758,9 @@ if __name__ == "__main__":
     parser.add_argument('-p', '--persist', choices=['erase', 'noerase'],
         nargs='?', const='erase',
         help="Store disk image in a file.")
-    parser.add_argument('-g', '--gdb', choices=['init', 'start', 'assert'],
+    parser.add_argument('-b', '--build', action='store_true',
+        help="Only build the tests, do not execute.")
+    parser.add_argument('-g', '--gdb', choices=['init', 'main', 'assert'],
         nargs='?', const='assert',
         help="Drop into gdb on test failure.")
     parser.add_argument('--no-internal', action='store_true',
@@ -741,4 +773,6 @@ if __name__ == "__main__":
         help="Run non-leaky tests under valgrind to check for memory leaks.")
     parser.add_argument('-e', '--exec', default=[], type=lambda e: e.split(' '),
         help="Run tests with another executable prefixed on the command line.")
+    parser.add_argument('-d', '--disk',
+        help="Specify a file to use for persistent/reentrant tests.")
     sys.exit(main(**vars(parser.parse_args())))

tests/test_alloc.toml

@@ -1,9 +1,10 @@
 # allocator tests
-# note for these to work there are many constraints on the device geometry
+# note for these to work there are a number constraints on the device geometry
+if = 'LFS_BLOCK_CYCLES == -1'
 
 [[case]] # parallel allocation test
 define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / FILES)'
+define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
     lfs_file_t files[FILES];
@@ -46,7 +47,7 @@ code = '''
 
 [[case]] # serial allocation test
 define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / FILES)'
+define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
 
@@ -85,7 +86,7 @@ code = '''
 
 [[case]] # parallel allocation reuse test
 define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / FILES)'
+define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
 define.CYCLES = [1, 10]
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
@@ -140,7 +141,7 @@ code = '''
 
 [[case]] # serial allocation reuse test
 define.FILES = 3
-define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-4)) / FILES)'
+define.SIZE = '(((LFS_BLOCK_SIZE-8)*(LFS_BLOCK_COUNT-6)) / FILES)'
 define.CYCLES = [1, 10]
 code = '''
     const char *names[FILES] = {"bacon", "eggs", "pancakes"};
@@ -322,6 +323,90 @@ code = '''
     lfs_unmount(&lfs) => 0;
 '''
 
+[[case]] # what if we have a bad block during an allocation scan?
+in = "lfs.c"
+define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_READERROR'
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    // first fill to exhaustion to find available space
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    lfs_size_t filesize = 0;
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_NOSPC);
+        if (res == LFS_ERR_NOSPC) {
+            break;
+        }
+        filesize += size;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    // now fill all but a couple of blocks of the filesystem with data
+    filesize -= 3*LFS_BLOCK_SIZE;
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    for (lfs_size_t i = 0; i < filesize/size; i++) {
+        lfs_file_write(&lfs, &file, buffer, size) => size;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    // also save head of file so we can error during lookahead scan
+    lfs_block_t fileblock = file.ctz.head;
+    lfs_unmount(&lfs) => 0;
+
+    // remount to force an alloc scan
+    lfs_mount(&lfs, &cfg) => 0;
+
+    // but mark the head of our file as a "bad block", this is force our
+    // scan to bail early
+    lfs_testbd_setwear(&cfg, fileblock, 0xffffffff) => 0;
+    lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "chomp");
+    size = strlen("chomp");
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_CORRUPT);
+        if (res == LFS_ERR_CORRUPT) {
+            break;
+        }
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    // now reverse the "bad block" and try to write the file again until we
+    // run out of space
+    lfs_testbd_setwear(&cfg, fileblock, 0) => 0;
+    lfs_file_open(&lfs, &file, "ghost", LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    strcpy((char*)buffer, "chomp");
+    size = strlen("chomp");
+    while (true) {
+        lfs_ssize_t res = lfs_file_write(&lfs, &file, buffer, size);
+        assert(res == (lfs_ssize_t)size || res == LFS_ERR_NOSPC);
+        if (res == LFS_ERR_NOSPC) {
+            break;
+        }
+    }
+    lfs_file_close(&lfs, &file) => 0;
+
+    lfs_unmount(&lfs) => 0;
+
+    // check that the disk isn't hurt
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "pacman", LFS_O_RDONLY) => 0;
+    strcpy((char*)buffer, "waka");
+    size = strlen("waka");
+    for (lfs_size_t i = 0; i < filesize/size; i++) {
+        uint8_t rbuffer[4];
+        lfs_file_read(&lfs, &file, rbuffer, size) => size;
+        assert(memcmp(rbuffer, buffer, size) == 0);
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+
 # Below, I don't like these tests. They're fragile and depend _heavily_
 # on the geometry of the block device. But they are valuable. Eventually they
 # should be removed and replaced with generalized tests.
@@ -329,7 +414,7 @@ code = '''
 [[case]] # chained dir exhaustion test
 define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 and LFS_BLOCK_COUNT == 1024'
+if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -400,7 +485,7 @@ code = '''
 [[case]] # split dir test
 define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 and LFS_BLOCK_COUNT == 1024'
+if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -445,7 +530,7 @@ code = '''
 [[case]] # outdated lookahead test
 define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 and LFS_BLOCK_COUNT == 1024'
+if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -510,7 +595,7 @@ code = '''
 [[case]] # outdated lookahead and split dir test
 define.LFS_BLOCK_SIZE = 512
 define.LFS_BLOCK_COUNT = 1024
-if = 'LFS_BLOCK_SIZE == 512 and LFS_BLOCK_COUNT == 1024'
+if = 'LFS_BLOCK_SIZE == 512 && LFS_BLOCK_COUNT == 1024'
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;

tests/test_badblocks.toml

@@ -1,6 +1,17 @@
+# bad blocks with block cycles should be tested in test_relocations
+if = 'LFS_BLOCK_CYCLES == -1'
+
 [[case]] # single bad blocks
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_NOPROG'
+define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
+define.LFS_BADBLOCK_BEHAVIOR = [
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
+]
 define.NAMEMULT = 64
 define.FILEMULT = 1
 code = '''
@@ -64,144 +75,16 @@ code = '''
     }
 '''
 
-[[case]] # single persistent blocks (can't erase)
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_NOERASE'
-define.NAMEMULT = 64
-define.FILEMULT = 1
-code = '''
-    for (lfs_block_t badblock = 2; badblock < LFS_BLOCK_COUNT; badblock++) {
-        lfs_testbd_setwear(&cfg, badblock-1, 0) => 0;
-        lfs_testbd_setwear(&cfg, badblock, 0xffffffff) => 0;
-        
-        lfs_format(&lfs, &cfg) => 0;
-
-        lfs_mount(&lfs, &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;
-
-            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, (char*)buffer,
-                    LFS_O_WRONLY | LFS_O_CREAT) => 0;
-            
-            size = NAMEMULT;
-            for (int j = 0; j < i*FILEMULT; j++) {
-                lfs_file_write(&lfs, &file, buffer, size) => size;
-            }
-
-            lfs_file_close(&lfs, &file) => 0;
-        }
-        lfs_unmount(&lfs) => 0;
-
-        lfs_mount(&lfs, &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;
-            info.type => LFS_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, (char*)buffer, LFS_O_RDONLY) => 0;
-            
-            size = NAMEMULT;
-            for (int j = 0; j < i*FILEMULT; j++) {
-                uint8_t rbuffer[1024];
-                lfs_file_read(&lfs, &file, rbuffer, size) => size;
-                memcmp(buffer, rbuffer, size) => 0;
-            }
-
-            lfs_file_close(&lfs, &file) => 0;
-        }
-        lfs_unmount(&lfs) => 0;
-    }
-'''
-
-[[case]] # single unreadable blocks (can't read)
-define.LFS_ERASE_CYCLES = 0xffffffff
-define.LFS_BADBLOCK_BEHAVIOR = 'LFS_TESTBD_BADBLOCK_NOREAD'
-define.NAMEMULT = 64
-define.FILEMULT = 1
-code = '''
-    for (lfs_block_t badblock = 2; badblock < LFS_BLOCK_COUNT/2; badblock++) {
-        lfs_testbd_setwear(&cfg, badblock-1, 0) => 0;
-        lfs_testbd_setwear(&cfg, badblock, 0xffffffff) => 0;
-        
-        lfs_format(&lfs, &cfg) => 0;
-
-        lfs_mount(&lfs, &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;
-
-            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, (char*)buffer,
-                    LFS_O_WRONLY | LFS_O_CREAT) => 0;
-            
-            size = NAMEMULT;
-            for (int j = 0; j < i*FILEMULT; j++) {
-                lfs_file_write(&lfs, &file, buffer, size) => size;
-            }
-
-            lfs_file_close(&lfs, &file) => 0;
-        }
-        lfs_unmount(&lfs) => 0;
-
-        lfs_mount(&lfs, &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;
-            info.type => LFS_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, (char*)buffer, LFS_O_RDONLY) => 0;
-            
-            size = NAMEMULT;
-            for (int j = 0; j < i*FILEMULT; j++) {
-                uint8_t rbuffer[1024];
-                lfs_file_read(&lfs, &file, rbuffer, size) => size;
-                memcmp(buffer, rbuffer, size) => 0;
-            }
-
-            lfs_file_close(&lfs, &file) => 0;
-        }
-        lfs_unmount(&lfs) => 0;
-    }
-'''
-
 [[case]] # region corruption (causes cascading failures)
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
 define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
 ]
 define.NAMEMULT = 64
 define.FILEMULT = 1
@@ -266,11 +149,15 @@ code = '''
 '''
 
 [[case]] # alternating corruption (causes cascading failures)
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
 define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
 ]
 define.NAMEMULT = 64
 define.FILEMULT = 1
@@ -337,10 +224,13 @@ code = '''
 # other corner cases
 [[case]] # bad superblocks (corrupt 1 or 0)
 define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_ERASE_VALUE = [0x00, 0xff, -1]
 define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
 ]
 code = '''
     lfs_testbd_setwear(&cfg, 0, 0xffffffff) => 0;

tests/test_dirs.toml

@@ -155,7 +155,7 @@ code = '''
 '''
 
 [[case]] # reentrant many directory creation/rename/removal
-define.N = [5, 25]
+define.N = [5, 11]
 reentrant = true
 code = '''
     err = lfs_mount(&lfs, &cfg);

tests/test_entries.toml

@@ -3,7 +3,7 @@
 # still pass with other inline sizes but wouldn't be testing anything.
 
 define.LFS_CACHE_SIZE = 512
-if = 'LFS_CACHE_SIZE == 512'
+if = 'LFS_CACHE_SIZE % LFS_PROG_SIZE == 0 && LFS_CACHE_SIZE == 512'
 
 [[case]] # entry grow test
 code = '''

tests/test_evil.toml

@@ -0,0 +1,288 @@
+# Tests for recovering from conditions which shouldn't normally
+# happen during normal operation of littlefs
+
+# invalid pointer tests (outside of block_count)
+
+[[case]] # invalid tail-pointer test
+define.TAIL_TYPE = ['LFS_TYPE_HARDTAIL', 'LFS_TYPE_SOFTTAIL']
+define.INVALSET = [0x3, 0x1, 0x2]
+in = "lfs.c"
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+
+    // change tail-pointer to invalid pointers
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
+                (lfs_block_t[2]){
+                    (INVALSET & 0x1) ? 0xcccccccc : 0,
+                    (INVALSET & 0x2) ? 0xcccccccc : 0}})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that mount fails gracefully
+    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+'''
+
+[[case]] # invalid dir pointer test
+define.INVALSET = [0x3, 0x1, 0x2]
+in = "lfs.c"
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+    // make a dir
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "dir_here") => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // change the dir pointer to be invalid
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    // make sure id 1 == our directory
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x700, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("dir_here")), buffer)
+                => LFS_MKTAG(LFS_TYPE_DIR, 1, strlen("dir_here"));
+    assert(memcmp((char*)buffer, "dir_here", strlen("dir_here")) == 0);
+    // change dir pointer
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, 8),
+                (lfs_block_t[2]){
+                    (INVALSET & 0x1) ? 0xcccccccc : 0,
+                    (INVALSET & 0x2) ? 0xcccccccc : 0}})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that accessing our bad dir fails, note there's a number
+    // of ways to access the dir, some can fail, but some don't
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_stat(&lfs, "dir_here", &info) => 0;
+    assert(strcmp(info.name, "dir_here") == 0);
+    assert(info.type == LFS_TYPE_DIR);
+
+    lfs_dir_open(&lfs, &dir, "dir_here") => LFS_ERR_CORRUPT;
+    lfs_stat(&lfs, "dir_here/file_here", &info) => LFS_ERR_CORRUPT;
+    lfs_dir_open(&lfs, &dir, "dir_here/dir_here") => LFS_ERR_CORRUPT;
+    lfs_file_open(&lfs, &file, "dir_here/file_here",
+            LFS_O_RDONLY) => LFS_ERR_CORRUPT;
+    lfs_file_open(&lfs, &file, "dir_here/file_here",
+            LFS_O_WRONLY | LFS_O_CREAT) => LFS_ERR_CORRUPT;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # invalid file pointer test
+in = "lfs.c"
+define.SIZE = [10, 1000, 100000] # faked file size
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+    // make a file
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "file_here",
+            LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // change the file pointer to be invalid
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    // make sure id 1 == our file
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x700, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
+                => LFS_MKTAG(LFS_TYPE_REG, 1, strlen("file_here"));
+    assert(memcmp((char*)buffer, "file_here", strlen("file_here")) == 0);
+    // change file pointer
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz)),
+                &(struct lfs_ctz){0xcccccccc, lfs_tole32(SIZE)}})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that accessing our bad file fails, note there's a number
+    // of ways to access the dir, some can fail, but some don't
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_stat(&lfs, "file_here", &info) => 0;
+    assert(strcmp(info.name, "file_here") == 0);
+    assert(info.type == LFS_TYPE_REG);
+    assert(info.size == SIZE);
+
+    lfs_file_open(&lfs, &file, "file_here", LFS_O_RDONLY) => 0;
+    lfs_file_read(&lfs, &file, buffer, SIZE) => LFS_ERR_CORRUPT;
+    lfs_file_close(&lfs, &file) => 0;
+
+    // any allocs that traverse CTZ must unfortunately must fail
+    if (SIZE > 2*LFS_BLOCK_SIZE) {
+        lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # invalid pointer in CTZ skip-list test
+define.SIZE = ['2*LFS_BLOCK_SIZE', '3*LFS_BLOCK_SIZE', '4*LFS_BLOCK_SIZE']
+in = "lfs.c"
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+    // make a file
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "file_here",
+            LFS_O_WRONLY | LFS_O_CREAT) => 0;
+    for (int i = 0; i < SIZE; i++) {
+        char c = 'c';
+        lfs_file_write(&lfs, &file, &c, 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+    // change pointer in CTZ skip-list to be invalid
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    // make sure id 1 == our file and get our CTZ structure
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x700, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_NAME, 1, strlen("file_here")), buffer)
+                => LFS_MKTAG(LFS_TYPE_REG, 1, strlen("file_here"));
+    assert(memcmp((char*)buffer, "file_here", strlen("file_here")) == 0);
+    struct lfs_ctz ctz;
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x700, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_STRUCT, 1, sizeof(struct lfs_ctz)), &ctz)
+                => LFS_MKTAG(LFS_TYPE_CTZSTRUCT, 1, sizeof(struct lfs_ctz));
+    lfs_ctz_fromle32(&ctz);
+    // rewrite block to contain bad pointer
+    uint8_t bbuffer[LFS_BLOCK_SIZE];
+    cfg.read(&cfg, ctz.head, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+    uint32_t bad = lfs_tole32(0xcccccccc);
+    memcpy(&bbuffer[0], &bad, sizeof(bad));
+    memcpy(&bbuffer[4], &bad, sizeof(bad));
+    cfg.erase(&cfg, ctz.head) => 0;
+    cfg.prog(&cfg, ctz.head, 0, bbuffer, LFS_BLOCK_SIZE) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that accessing our bad file fails, note there's a number
+    // of ways to access the dir, some can fail, but some don't
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_stat(&lfs, "file_here", &info) => 0;
+    assert(strcmp(info.name, "file_here") == 0);
+    assert(info.type == LFS_TYPE_REG);
+    assert(info.size == SIZE);
+
+    lfs_file_open(&lfs, &file, "file_here", LFS_O_RDONLY) => 0;
+    lfs_file_read(&lfs, &file, buffer, SIZE) => LFS_ERR_CORRUPT;
+    lfs_file_close(&lfs, &file) => 0;
+
+    // any allocs that traverse CTZ must unfortunately must fail
+    if (SIZE > 2*LFS_BLOCK_SIZE) {
+        lfs_mkdir(&lfs, "dir_here") => LFS_ERR_CORRUPT;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+
+[[case]] # invalid gstate pointer
+define.INVALSET = [0x3, 0x1, 0x2]
+in = "lfs.c"
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+
+    // create an invalid gstate
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_fs_prepmove(&lfs, 1, (lfs_block_t [2]){
+            (INVALSET & 0x1) ? 0xcccccccc : 0,
+            (INVALSET & 0x2) ? 0xcccccccc : 0});
+    lfs_dir_commit(&lfs, &mdir, NULL, 0) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that mount fails gracefully
+    // mount may not fail, but our first alloc should fail when
+    // we try to fix the gstate
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "should_fail") => LFS_ERR_CORRUPT;
+    lfs_unmount(&lfs) => 0;
+'''
+
+# cycle detection/recovery tests
+
+[[case]] # metadata-pair threaded-list loop test
+in = "lfs.c"
+code = '''
+    // create littlefs
+    lfs_format(&lfs, &cfg) => 0;
+
+    // change tail-pointer to point to ourself
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
+                (lfs_block_t[2]){0, 1}})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that mount fails gracefully
+    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+'''
+
+[[case]] # metadata-pair threaded-list 2-length loop test
+in = "lfs.c"
+code = '''
+    // create littlefs with child dir
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "child") => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // find child
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_block_t pair[2];
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x7ff, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
+                => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
+    lfs_pair_fromle32(pair);
+    // change tail-pointer to point to root
+    lfs_dir_fetch(&lfs, &mdir, pair) => 0;
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8),
+                (lfs_block_t[2]){0, 1}})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that mount fails gracefully
+    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+'''
+
+[[case]] # metadata-pair threaded-list 1-length child loop test
+in = "lfs.c"
+code = '''
+    // create littlefs with child dir
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "child") => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // find child
+    lfs_init(&lfs, &cfg) => 0;
+    lfs_mdir_t mdir;
+    lfs_block_t pair[2];
+    lfs_dir_fetch(&lfs, &mdir, (lfs_block_t[2]){0, 1}) => 0;
+    lfs_dir_get(&lfs, &mdir,
+            LFS_MKTAG(0x7ff, 0x3ff, 0),
+            LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair)), pair)
+                => LFS_MKTAG(LFS_TYPE_DIRSTRUCT, 1, sizeof(pair));
+    lfs_pair_fromle32(pair);
+    // change tail-pointer to point to ourself
+    lfs_dir_fetch(&lfs, &mdir, pair) => 0;
+    lfs_dir_commit(&lfs, &mdir, LFS_MKATTRS(
+            {LFS_MKTAG(LFS_TYPE_HARDTAIL, 0x3ff, 8), pair})) => 0;
+    lfs_deinit(&lfs) => 0;
+
+    // test that mount fails gracefully
+    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+'''

tests/test_exhaustion.toml

@@ -1,11 +1,13 @@
 [[case]] # test running a filesystem to exhaustion
 define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so it runs faster
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
 define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
 ]
 define.FILES = 10
 code = '''
@@ -31,6 +33,9 @@ code = '''
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
+                    err = lfs_file_close(&lfs, &file);
+                    assert(err == 0 || err == LFS_ERR_NOSPC);
+                    lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
@@ -38,6 +43,7 @@ code = '''
             err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
+                lfs_unmount(&lfs) => 0;
                 goto exhausted;
             }
         }
@@ -79,12 +85,14 @@ exhausted:
 [[case]] # test running a filesystem to exhaustion
          # which also requires expanding superblocks
 define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so it runs faster
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
 define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
+    'LFS_TESTBD_BADBLOCK_PROGERROR',
+    'LFS_TESTBD_BADBLOCK_ERASEERROR',
+    'LFS_TESTBD_BADBLOCK_READERROR',
+    'LFS_TESTBD_BADBLOCK_PROGNOOP',
+    'LFS_TESTBD_BADBLOCK_ERASENOOP',
 ]
 define.FILES = 10
 code = '''
@@ -107,6 +115,9 @@ code = '''
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
+                    err = lfs_file_close(&lfs, &file);
+                    assert(err == 0 || err == LFS_ERR_NOSPC);
+                    lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
@@ -114,6 +125,7 @@ code = '''
             err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
+                lfs_unmount(&lfs) => 0;
                 goto exhausted;
             }
         }
@@ -158,38 +170,207 @@ exhausted:
 # check for.
 
 [[case]] # wear-level test running a filesystem to exhaustion
-define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so it runs faster
+define.LFS_ERASE_CYCLES = 20
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
 define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
-]
 define.FILES = 10
+code = '''
+    uint32_t run_cycles[2];
+    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
+
+    for (int run = 0; run < 2; run++) {
+        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
+            lfs_testbd_setwear(&cfg, b,
+                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
+        }
+
+        lfs_format(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg) => 0;
+        lfs_mkdir(&lfs, "roadrunner") => 0;
+        lfs_unmount(&lfs) => 0;
+
+        uint32_t cycle = 0;
+        while (true) {
+            lfs_mount(&lfs, &cfg) => 0;
+            for (uint32_t i = 0; i < FILES; i++) {
+                // chose name, roughly random seed, and random 2^n size
+                sprintf(path, "roadrunner/test%d", i);
+                srand(cycle * i);
+                size = 1 << ((rand() % 10)+2);
+
+                lfs_file_open(&lfs, &file, path,
+                        LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+
+                for (lfs_size_t j = 0; j < size; j++) {
+                    char c = 'a' + (rand() % 26);
+                    lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
+                    assert(res == 1 || res == LFS_ERR_NOSPC);
+                    if (res == LFS_ERR_NOSPC) {
+                        err = lfs_file_close(&lfs, &file);
+                        assert(err == 0 || err == LFS_ERR_NOSPC);
+                        lfs_unmount(&lfs) => 0;
+                        goto exhausted;
+                    }
+                }
+
+                err = lfs_file_close(&lfs, &file);
+                assert(err == 0 || err == LFS_ERR_NOSPC);
+                if (err == LFS_ERR_NOSPC) {
+                    lfs_unmount(&lfs) => 0;
+                    goto exhausted;
+                }
+            }
+
+            for (uint32_t i = 0; i < FILES; i++) {
+                // check for errors
+                sprintf(path, "roadrunner/test%d", i);
+                srand(cycle * i);
+                size = 1 << ((rand() % 10)+2);
+
+                lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
+                for (lfs_size_t j = 0; j < size; j++) {
+                    char c = 'a' + (rand() % 26);
+                    char r;
+                    lfs_file_read(&lfs, &file, &r, 1) => 1;
+                    assert(r == c);
+                }
+
+                lfs_file_close(&lfs, &file) => 0;
+            }
+            lfs_unmount(&lfs) => 0;
+
+            cycle += 1;
+        }
+
+exhausted:
+        // should still be readable
+        lfs_mount(&lfs, &cfg) => 0;
+        for (uint32_t i = 0; i < FILES; i++) {
+            // check for errors
+            sprintf(path, "roadrunner/test%d", i);
+            lfs_stat(&lfs, path, &info) => 0;
+        }
+        lfs_unmount(&lfs) => 0;
+
+        run_cycles[run] = cycle;
+        LFS_WARN("completed %d blocks %d cycles",
+                run_block_count[run], run_cycles[run]);
+    }
+
+    // check we increased the lifetime by 2x with ~10% error
+    LFS_ASSERT(run_cycles[1]*110/100 > 2*run_cycles[0]);
+'''
+
+[[case]] # wear-level test + expanding superblock
+define.LFS_ERASE_CYCLES = 20
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
+define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
+define.FILES = 10
+code = '''
+    uint32_t run_cycles[2];
+    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
+
+    for (int run = 0; run < 2; run++) {
+        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
+            lfs_testbd_setwear(&cfg, b,
+                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
+        }
+
+        lfs_format(&lfs, &cfg) => 0;
+
+        uint32_t cycle = 0;
+        while (true) {
+            lfs_mount(&lfs, &cfg) => 0;
+            for (uint32_t i = 0; i < FILES; i++) {
+                // chose name, roughly random seed, and random 2^n size
+                sprintf(path, "test%d", i);
+                srand(cycle * i);
+                size = 1 << ((rand() % 10)+2);
+
+                lfs_file_open(&lfs, &file, path,
+                        LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+
+                for (lfs_size_t j = 0; j < size; j++) {
+                    char c = 'a' + (rand() % 26);
+                    lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
+                    assert(res == 1 || res == LFS_ERR_NOSPC);
+                    if (res == LFS_ERR_NOSPC) {
+                        err = lfs_file_close(&lfs, &file);
+                        assert(err == 0 || err == LFS_ERR_NOSPC);
+                        lfs_unmount(&lfs) => 0;
+                        goto exhausted;
+                    }
+                }
+
+                err = lfs_file_close(&lfs, &file);
+                assert(err == 0 || err == LFS_ERR_NOSPC);
+                if (err == LFS_ERR_NOSPC) {
+                    lfs_unmount(&lfs) => 0;
+                    goto exhausted;
+                }
+            }
+
+            for (uint32_t i = 0; i < FILES; i++) {
+                // check for errors
+                sprintf(path, "test%d", i);
+                srand(cycle * i);
+                size = 1 << ((rand() % 10)+2);
+
+                lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
+                for (lfs_size_t j = 0; j < size; j++) {
+                    char c = 'a' + (rand() % 26);
+                    char r;
+                    lfs_file_read(&lfs, &file, &r, 1) => 1;
+                    assert(r == c);
+                }
+
+                lfs_file_close(&lfs, &file) => 0;
+            }
+            lfs_unmount(&lfs) => 0;
+
+            cycle += 1;
+        }
+
+exhausted:
+        // should still be readable
+        lfs_mount(&lfs, &cfg) => 0;
+        for (uint32_t i = 0; i < FILES; i++) {
+            // check for errors
+            sprintf(path, "test%d", i);
+            lfs_stat(&lfs, path, &info) => 0;
+        }
+        lfs_unmount(&lfs) => 0;
+
+        run_cycles[run] = cycle;
+        LFS_WARN("completed %d blocks %d cycles",
+                run_block_count[run], run_cycles[run]);
+    }
+
+    // check we increased the lifetime by 2x with ~10% error
+    LFS_ASSERT(run_cycles[1]*110/100 > 2*run_cycles[0]);
+'''
+
+[[case]] # test that we wear blocks roughly evenly
+define.LFS_ERASE_CYCLES = 0xffffffff
+define.LFS_BLOCK_COUNT = 256 # small bd so test runs faster
+define.LFS_BLOCK_CYCLES = [5, 4, 3, 2, 1]
+define.CYCLES = 100
+define.FILES = 10
+if = 'LFS_BLOCK_CYCLES < CYCLES/10'
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, "roadrunner") => 0;
     lfs_unmount(&lfs) => 0;
 
-    uint32_t run_cycles[2];
-    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
-
-    for (int run = 0; run < 2; run++) {
-        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
-            lfs_testbd_setwear(&cfg, b,
-                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
-        }
-
     uint32_t cycle = 0;
-        while (true) {
+    while (cycle < CYCLES) {
         lfs_mount(&lfs, &cfg) => 0;
         for (uint32_t i = 0; i < FILES; i++) {
             // chose name, roughly random seed, and random 2^n size
             sprintf(path, "roadrunner/test%d", i);
             srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+            size = 1 << 4; //((rand() % 10)+2);
 
             lfs_file_open(&lfs, &file, path,
                     LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
@@ -199,6 +380,9 @@ code = '''
                 lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
                 assert(res == 1 || res == LFS_ERR_NOSPC);
                 if (res == LFS_ERR_NOSPC) {
+                    err = lfs_file_close(&lfs, &file);
+                    assert(err == 0 || err == LFS_ERR_NOSPC);
+                    lfs_unmount(&lfs) => 0;
                     goto exhausted;
                 }
             }
@@ -206,6 +390,7 @@ code = '''
             err = lfs_file_close(&lfs, &file);
             assert(err == 0 || err == LFS_ERR_NOSPC);
             if (err == LFS_ERR_NOSPC) {
+                lfs_unmount(&lfs) => 0;
                 goto exhausted;
             }
         }
@@ -214,7 +399,7 @@ code = '''
             // check for errors
             sprintf(path, "roadrunner/test%d", i);
             srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
+            size = 1 << 4; //((rand() % 10)+2);
 
             lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
             for (lfs_size_t j = 0; j < size; j++) {
@@ -241,101 +426,40 @@ exhausted:
     }
     lfs_unmount(&lfs) => 0;
 
-        run_cycles[run] = cycle;
-        LFS_WARN("completed %d blocks %d cycles",
-                run_block_count[run], run_cycles[run]);
-    }
+    LFS_WARN("completed %d cycles", cycle);
 
-    // check we increased the lifetime by 2x with ~10% error
-    LFS_ASSERT(run_cycles[1] > 2*run_cycles[0]-run_cycles[0]/10);
+    // check the wear on our block device
+    lfs_testbd_wear_t minwear = -1;
+    lfs_testbd_wear_t totalwear = 0;
+    lfs_testbd_wear_t maxwear = 0;
+    // skip 0 and 1 as superblock movement is intentionally avoided
+    for (lfs_block_t b = 2; b < LFS_BLOCK_COUNT; b++) {
+        lfs_testbd_wear_t wear = lfs_testbd_getwear(&cfg, b);
+        printf("%08x: wear %d\n", b, wear);
+        assert(wear >= 0);
+        if (wear < minwear) {
+            minwear = wear;
+        }
+        if (wear > maxwear) {
+            maxwear = wear;
+        }
+        totalwear += wear;
+    }
+    lfs_testbd_wear_t avgwear = totalwear / LFS_BLOCK_COUNT;
+    LFS_WARN("max wear: %d cycles", maxwear);
+    LFS_WARN("avg wear: %d cycles", totalwear / LFS_BLOCK_COUNT);
+    LFS_WARN("min wear: %d cycles", minwear);
+
+    // find standard deviation^2
+    lfs_testbd_wear_t dev2 = 0;
+    for (lfs_block_t b = 2; b < LFS_BLOCK_COUNT; b++) {
+        lfs_testbd_wear_t wear = lfs_testbd_getwear(&cfg, b);
+        assert(wear >= 0);
+        lfs_testbd_swear_t diff = wear - avgwear;
+        dev2 += diff*diff;
+    }
+    dev2 /= totalwear;
+    LFS_WARN("std dev^2: %d", dev2);
+    assert(dev2 < 8);
 '''
 
-[[case]] # wear-level test + expanding superblock
-define.LFS_ERASE_CYCLES = 10
-define.LFS_BLOCK_COUNT = 256 # small bd so it runs faster
-define.LFS_BLOCK_CYCLES = 'LFS_ERASE_CYCLES / 2'
-define.LFS_BADBLOCK_BEHAVIOR = [
-    'LFS_TESTBD_BADBLOCK_NOPROG',
-    'LFS_TESTBD_BADBLOCK_NOERASE',
-    'LFS_TESTBD_BADBLOCK_NOREAD',
-]
-define.FILES = 10
-code = '''
-    lfs_format(&lfs, &cfg) => 0;
-
-    uint32_t run_cycles[2];
-    const uint32_t run_block_count[2] = {LFS_BLOCK_COUNT/2, LFS_BLOCK_COUNT};
-
-    for (int run = 0; run < 2; run++) {
-        for (lfs_block_t b = 0; b < LFS_BLOCK_COUNT; b++) {
-            lfs_testbd_setwear(&cfg, b,
-                    (b < run_block_count[run]) ? 0 : LFS_ERASE_CYCLES) => 0;
-        }
-
-        uint32_t cycle = 0;
-        while (true) {
-            lfs_mount(&lfs, &cfg) => 0;
-            for (uint32_t i = 0; i < FILES; i++) {
-                // chose name, roughly random seed, and random 2^n size
-                sprintf(path, "test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
-
-                lfs_file_open(&lfs, &file, path,
-                        LFS_O_WRONLY | LFS_O_CREAT | LFS_O_TRUNC) => 0;
-
-                for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
-                    lfs_ssize_t res = lfs_file_write(&lfs, &file, &c, 1);
-                    assert(res == 1 || res == LFS_ERR_NOSPC);
-                    if (res == LFS_ERR_NOSPC) {
-                        goto exhausted;
-                    }
-                }
-
-                err = lfs_file_close(&lfs, &file);
-                assert(err == 0 || err == LFS_ERR_NOSPC);
-                if (err == LFS_ERR_NOSPC) {
-                    goto exhausted;
-                }
-            }    
-
-            for (uint32_t i = 0; i < FILES; i++) {
-                // check for errors
-                sprintf(path, "test%d", i);
-                srand(cycle * i);
-                size = 1 << ((rand() % 10)+2);
-
-                lfs_file_open(&lfs, &file, path, LFS_O_RDONLY) => 0;
-                for (lfs_size_t j = 0; j < size; j++) {
-                    char c = 'a' + (rand() % 26);
-                    char r;
-                    lfs_file_read(&lfs, &file, &r, 1) => 1;
-                    assert(r == c);
-                }
-
-                lfs_file_close(&lfs, &file) => 0;
-            }    
-            lfs_unmount(&lfs) => 0;
-
-            cycle += 1;
-        }
-
-exhausted:
-        // should still be readable
-        lfs_mount(&lfs, &cfg) => 0;
-        for (uint32_t i = 0; i < FILES; i++) {
-            // check for errors
-            sprintf(path, "test%d", i);
-            lfs_stat(&lfs, path, &info) => 0;
-        }    
-        lfs_unmount(&lfs) => 0;
-
-        run_cycles[run] = cycle;
-        LFS_WARN("completed %d blocks %d cycles",
-                run_block_count[run], run_cycles[run]);
-    }
-
-    // check we increased the lifetime by 2x with ~10% error
-    LFS_ASSERT(run_cycles[1] > 2*run_cycles[0]-run_cycles[0]/10);
-'''

tests/test_move.toml

@@ -148,6 +148,7 @@ code = '''
 
 [[case]] # move file corrupt source and dest
 in = "lfs.c"
+if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -239,6 +240,7 @@ code = '''
 
 [[case]] # move file after corrupt
 in = "lfs.c"
+if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -593,6 +595,7 @@ code = '''
 
 [[case]] # move dir corrupt source and dest
 in = "lfs.c"
+if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -692,6 +695,7 @@ code = '''
 
 [[case]] # move dir after corrupt
 in = "lfs.c"
+if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;

tests/test_orphans.toml

@@ -1,5 +1,6 @@
 [[case]] # orphan test
 in = "lfs.c"
+if = 'LFS_PROG_SIZE <= 0x3fe' # only works with one crc per commit
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
@@ -57,10 +58,12 @@ code = '''
 
 [[case]] # reentrant testing for orphans, basically just spam mkdir/remove
 reentrant = true
+# TODO fix this case, caused by non-DAG trees
+if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
 define = [
-    {FILES=6,  DEPTH=1, CYCLES=50},
-    {FILES=26, DEPTH=1, CYCLES=50},
-    {FILES=3,  DEPTH=3, CYCLES=50},
+    {FILES=6,  DEPTH=1, CYCLES=20},
+    {FILES=26, DEPTH=1, CYCLES=20},
+    {FILES=3,  DEPTH=3, CYCLES=20},
 ]
 code = '''
     err = lfs_mount(&lfs, &cfg);

tests/test_paths.toml

@@ -247,14 +247,14 @@ code = '''
     lfs_mkdir(&lfs, "coffee/coldcoffee") => 0;
 
     memset(path, 'w', LFS_NAME_MAX+1);
-    path[LFS_NAME_MAX+2] = '\0';
+    path[LFS_NAME_MAX+1] = '\0';
     lfs_mkdir(&lfs, path) => LFS_ERR_NAMETOOLONG;
     lfs_file_open(&lfs, &file, path, LFS_O_WRONLY | LFS_O_CREAT)
             => LFS_ERR_NAMETOOLONG;
 
     memcpy(path, "coffee/", strlen("coffee/"));
     memset(path+strlen("coffee/"), 'w', LFS_NAME_MAX+1);
-    path[strlen("coffee/")+LFS_NAME_MAX+2] = '\0';
+    path[strlen("coffee/")+LFS_NAME_MAX+1] = '\0';
     lfs_mkdir(&lfs, path) => LFS_ERR_NAMETOOLONG;
     lfs_file_open(&lfs, &file, path, LFS_O_WRONLY | LFS_O_CREAT)
             => LFS_ERR_NAMETOOLONG;
@@ -270,7 +270,6 @@ code = '''
     lfs_mkdir(&lfs, "coffee/warmcoffee") => 0;
     lfs_mkdir(&lfs, "coffee/coldcoffee") => 0;
 
-    lfs_mount(&lfs, &cfg) => 0;
     memset(path, 'w', LFS_NAME_MAX);
     path[LFS_NAME_MAX] = '\0';
     lfs_mkdir(&lfs, path) => 0;

tests/test_relocations.toml

@@ -147,10 +147,12 @@ code = '''
          # orphan testing, except here we also set block_cycles so that
          # almost every tree operation needs a relocation
 reentrant = true
+# TODO fix this case, caused by non-DAG trees
+if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
 define = [
-    {FILES=6,  DEPTH=1, CYCLES=50, LFS_BLOCK_CYCLES=1},
-    {FILES=26, DEPTH=1, CYCLES=50, LFS_BLOCK_CYCLES=1},
-    {FILES=3,  DEPTH=3, CYCLES=50, LFS_BLOCK_CYCLES=1},
+    {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
 ]
 code = '''
     err = lfs_mount(&lfs, &cfg);
@@ -207,10 +209,12 @@ code = '''
 
 [[case]] # reentrant testing for relocations, but now with random renames!
 reentrant = true
+# TODO fix this case, caused by non-DAG trees
+if = '!(DEPTH == 3 && LFS_CACHE_SIZE != 64)'
 define = [
-    {FILES=6,  DEPTH=1, CYCLES=50, LFS_BLOCK_CYCLES=1},
-    {FILES=26, DEPTH=1, CYCLES=50, LFS_BLOCK_CYCLES=1},
-    {FILES=3,  DEPTH=3, CYCLES=50, LFS_BLOCK_CYCLES=1},
+    {FILES=6,  DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
+    {FILES=26, DEPTH=1, CYCLES=20, LFS_BLOCK_CYCLES=1},
+    {FILES=3,  DEPTH=3, CYCLES=20, LFS_BLOCK_CYCLES=1},
 ]
 code = '''
     err = lfs_mount(&lfs, &cfg);

tests/test_superblocks.toml

@@ -27,41 +27,55 @@ code = '''
 '''
 
 [[case]] # expanding superblock
-define.BLOCK_CYCLES = [32, 33, 1]
+define.LFS_BLOCK_CYCLES = [32, 33, 1]
 define.N = [10, 100, 1000]
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     lfs_mount(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
-        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_file_open(&lfs, &file, "dummy",
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        lfs_file_close(&lfs, &file) => 0;
         lfs_stat(&lfs, "dummy", &info) => 0;
         assert(strcmp(info.name, "dummy") == 0);
+        assert(info.type == LFS_TYPE_REG);
         lfs_remove(&lfs, "dummy") => 0;
     }
     lfs_unmount(&lfs) => 0;
 
     // one last check after power-cycle
     lfs_mount(&lfs, &cfg) => 0;
-    lfs_mkdir(&lfs, "dummy") => 0;
+    lfs_file_open(&lfs, &file, "dummy",
+            LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+    lfs_file_close(&lfs, &file) => 0;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
+    assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # expanding superblock with power cycle
-define.BLOCK_CYCLES = [32, 33, 1]
+define.LFS_BLOCK_CYCLES = [32, 33, 1]
 define.N = [10, 100, 1000]
 code = '''
     lfs_format(&lfs, &cfg) => 0;
     for (int i = 0; i < N; i++) {
         lfs_mount(&lfs, &cfg) => 0;
         // remove lingering dummy?
-        err = lfs_remove(&lfs, "dummy");
+        err = lfs_stat(&lfs, "dummy", &info);
         assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
+        if (!err) {
+            assert(strcmp(info.name, "dummy") == 0);
+            assert(info.type == LFS_TYPE_REG);
+            lfs_remove(&lfs, "dummy") => 0;
+        }
 
-        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_file_open(&lfs, &file, "dummy",
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        lfs_file_close(&lfs, &file) => 0;
         lfs_stat(&lfs, "dummy", &info) => 0;
         assert(strcmp(info.name, "dummy") == 0);
+        assert(info.type == LFS_TYPE_REG);
         lfs_unmount(&lfs) => 0;
     }
 
@@ -69,11 +83,12 @@ code = '''
     lfs_mount(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
+    assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # reentrant expanding superblock
-define.BLOCK_CYCLES = [2, 1]
+define.LFS_BLOCK_CYCLES = [2, 1]
 define.N = 24
 reentrant = true
 code = '''
@@ -85,12 +100,20 @@ code = '''
 
     for (int i = 0; i < N; i++) {
         // remove lingering dummy?
-        err = lfs_remove(&lfs, "dummy");
+        err = lfs_stat(&lfs, "dummy", &info);
         assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
+        if (!err) {
+            assert(strcmp(info.name, "dummy") == 0);
+            assert(info.type == LFS_TYPE_REG);
+            lfs_remove(&lfs, "dummy") => 0;
+        }
 
-        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_file_open(&lfs, &file, "dummy",
+                LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
+        lfs_file_close(&lfs, &file) => 0;
         lfs_stat(&lfs, "dummy", &info) => 0;
         assert(strcmp(info.name, "dummy") == 0);
+        assert(info.type == LFS_TYPE_REG);
     }
 
     lfs_unmount(&lfs) => 0;
@@ -99,5 +122,6 @@ code = '''
     lfs_mount(&lfs, &cfg) => 0;
     lfs_stat(&lfs, "dummy", &info) => 0;
     assert(strcmp(info.name, "dummy") == 0);
+    assert(info.type == LFS_TYPE_REG);
     lfs_unmount(&lfs) => 0;
 '''

tests/test_truncate.toml

@@ -100,7 +100,7 @@ code = '''
     lfs_file_open(&lfs, &file, "sequence",
             LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
 
-    size = lfs.cfg->cache_size;
+    size = lfs_min(lfs.cfg->cache_size, sizeof(buffer)/2);
     lfs_size_t qsize = size / 4;
     uint8_t *wb = buffer;
     uint8_t *rb = buffer + size;