Added test_new.toml with failure found by AFL

Found by pjsg
Added "evil" tests and detecion/recovery from bad pointers and infinite loops
2025-11-01 08:48:31 +01:00 · 2020-03-26 15:27:30 -05:00 · 2020-03-20 09:26:07 -05:00 · 2020-02-23 22:18:08 -06:00 · 2020-02-22 23:50:03 -06:00 · 2020-02-22 23:35:28 -06:00
18 changed files with 1011 additions and 423 deletions
--- a/.travis.yml
+++ b/.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 [ "$TRAVIS_TEST_RESULT" -eq 0 ]
@@ -51,10 +72,10 @@ script:
        CURR=$(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)
-
+  
        STATUS="Passed, code size is ${CURR}B"
        if [ "$PREV" -ne 0 ]
        then
@@ -62,257 +83,347 @@ 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
-      env:
-        - STAGE=test
-        - NAME=littlefs-x86
+  # native testing
+  - &x86
+    stage: test
+    env:
+      - 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
-      env:
-        - STAGE=test
-        - NAME=littlefs-arm
-        - CC="arm-linux-gnueabi-gcc --static -mthumb"
-        - EXEC="qemu-arm"
-      install:
-        - sudo apt-get install
-              gcc-arm-linux-gnueabi
-              libc6-dev-armel-cross
-              qemu-user
-        - arm-linux-gnueabi-gcc --version
-        - qemu-arm -version
+  # cross-compile with ARM (thumb mode)
+  - &arm
+    stage: test
+    env:
+      - NAME=littlefs-arm
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - 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
+    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 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
+  # cross-compile with MIPS
+  - &mips
+    stage: test
+    env:
+      - NAME=littlefs-mips
+      - CC="mips-linux-gnu-gcc --static"
+      - 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 MIPS
-    - stage: test
-      env:
-        - STAGE=test
-        - NAME=littlefs-mips
-        - CC="mips-linux-gnu-gcc --static"
-        - EXEC="qemu-mips"
-      install:
-        - sudo apt-get install
-              gcc-mips-linux-gnu
-              libc6-dev-mips-cross
-              qemu-user
-        - mips-linux-gnu-gcc --version
-        - qemu-mips -version
+  # 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]}

-    # self-host with littlefs-fuse for fuzz test
-    - stage: test
-      env:
-        - STAGE=test
-        - NAME=littlefs-fuse
-      if: branch !~ -prefix$
-      install:
-        - 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
+  # 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"

-        - mkdir mount
-        - sudo chmod a+rw /dev/loop0
-        - dd if=/dev/zero bs=512 count=4096 of=disk
-        - losetup /dev/loop0 disk
-      script:
-        # self-host test
-        - make -C littlefs-fuse
+  # self-host with littlefs-fuse for fuzz test
+  - stage: test
+    env:
+      - 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

-        - littlefs-fuse/lfs --format /dev/loop0
-        - littlefs-fuse/lfs /dev/loop0 mount
+      # setup disk for littlefs-fuse
+      - rm -rf littlefs-fuse/littlefs/*
+      - cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs

-        - ls mount
-        - mkdir mount/littlefs
-        - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-        - cd mount/littlefs
-        - stat .
-        - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      - mkdir mount
+      - sudo chmod a+rw /dev/loop0
+      - dd if=/dev/zero bs=512 count=128K of=disk
+      - losetup /dev/loop0 disk
+    script:
+      # self-host test
+      - make -C littlefs-fuse

-    # self-host with littlefs-fuse for fuzz test
-    - stage: test
-      env:
-        - STAGE=test
-        - NAME=littlefs-migration
-      if: branch !~ -prefix$
-      install:
-        - 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
+      - littlefs-fuse/lfs --format /dev/loop0
+      - littlefs-fuse/lfs /dev/loop0 mount

-        - mkdir mount
-        - sudo chmod a+rw /dev/loop0
-        - dd if=/dev/zero bs=512 count=4096 of=disk
-        - losetup /dev/loop0 disk
-      script:
-        # compile v1 and v2
-        - make -C v1
-        - make -C v2
+      - ls mount
+      - mkdir mount/littlefs
+      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test

-        # run self-host test with v1
-        - v1/lfs --format /dev/loop0
-        - v1/lfs /dev/loop0 mount
+  # test migration using littlefs-fuse
+  - stage: test
+    env:
+      - 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

-        - ls mount
-        - mkdir mount/littlefs
-        - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-        - cd mount/littlefs
-        - stat .
-        - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      # setup disk for littlefs-fuse
+      - rm -rf v2/littlefs/*
+      - cp -r $(git ls-tree --name-only HEAD) v2/littlefs

-        # attempt to migrate
-        - cd ../..
-        - fusermount -u mount
+      - mkdir mount
+      - sudo chmod a+rw /dev/loop0
+      - dd if=/dev/zero bs=512 count=128K of=disk
+      - losetup /dev/loop0 disk
+    script:
+      # compile v1 and v2
+      - make -C v1
+      - make -C v2

-        - v2/lfs --migrate /dev/loop0
-        - v2/lfs /dev/loop0 mount
+      # run self-host test with v1
+      - v1/lfs --format /dev/loop0
+      - v1/lfs /dev/loop0 mount

-        # run self-host test with v2 right where we left off
-        - ls mount
-        - cd mount/littlefs
-        - stat .
-        - ls -flh
-        - make -B test_dirs test_files QUIET=1
+      - ls mount
+      - mkdir mount/littlefs
+      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test

-    # Automatically create releases
-    - stage: deploy
-      env:
-        - STAGE=deploy
-        - NAME=deploy
-      script:
-        - |
-          bash << 'SCRIPT'
-          set -ev
-          # Find version defined in lfs.h
-          LFS_VERSION=$(grep -ox '#define LFS_VERSION .*' lfs.h | cut -d ' ' -f3)
-          LFS_VERSION_MAJOR=$((0xffff & ($LFS_VERSION >> 16)))
-          LFS_VERSION_MINOR=$((0xffff & ($LFS_VERSION >>  0)))
-          # Grab latests patch from repo tags, default to 0, needs finagling
-          # to get past github's pagination api
-          PREV_URL=https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs/tags/v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.
-          PREV_URL=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" -I \
-              | sed -n '/^Link/{s/.*<\(.*\)>; rel="last"/\1/;p;q0};$q1' \
-              || echo $PREV_URL)
-          LFS_VERSION_PATCH=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" \
-              | jq 'map(.ref | match("\\bv.*\\..*\\.(.*)$";"g")
-                  .captures[].string | tonumber) | max + 1' \
-              || echo 0)
-          # We have our new version
-          LFS_VERSION="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.$LFS_VERSION_PATCH"
-          echo "VERSION $LFS_VERSION"
-          # Check that we're the most recent commit
-          CURRENT_COMMIT=$(curl -f -u "$GEKY_BOT_RELEASES" \
-              https://api.github.com/repos/$TRAVIS_REPO_SLUG/commits/master \
-              | jq -re '.sha')
-          [ "$TRAVIS_COMMIT" == "$CURRENT_COMMIT" ] || exit 0
-          # Create major branch
-          git branch v$LFS_VERSION_MAJOR HEAD
-          # Create major prefix branch
-          git config user.name "geky bot"
-          git config user.email "bot@geky.net"
-          git fetch https://github.com/$TRAVIS_REPO_SLUG.git \
-              --depth=50 v$LFS_VERSION_MAJOR-prefix || true
-          ./scripts/prefix.py lfs$LFS_VERSION_MAJOR
-          git branch v$LFS_VERSION_MAJOR-prefix $( \
-              git commit-tree $(git write-tree) \
-                  $(git rev-parse --verify -q FETCH_HEAD | sed -e 's/^/-p /') \
-                  -p HEAD \
-                  -m "Generated v$LFS_VERSION_MAJOR prefixes")
-          git reset --hard
-          # Update major version branches (vN and vN-prefix)
-          git push --atomic https://$GEKY_BOT_RELEASES@github.com/$TRAVIS_REPO_SLUG.git \
-              v$LFS_VERSION_MAJOR \
-              v$LFS_VERSION_MAJOR-prefix
-          # Build release notes
-          PREV=$(git tag --sort=-v:refname -l "v*" | head -1)
-          if [ ! -z "$PREV" ]
-          then
-              echo "PREV $PREV"
-              CHANGES=$(git log --oneline $PREV.. --grep='^Merge' --invert-grep)
-              printf "CHANGES\n%s\n\n" "$CHANGES"
-          fi
-          case ${GEKY_BOT_DRAFT:-minor} in
-              true)  DRAFT=true ;;
-              minor) DRAFT=$(jq -R 'endswith(".0")' <<< "$LFS_VERSION") ;;
-              false) DRAFT=false ;;
-          esac
-          # Create the release and patch version tag (vN.N.N)
-          curl -f -u "$GEKY_BOT_RELEASES" -X POST \
-              https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases \
-              -d "{
-                  \"tag_name\": \"$LFS_VERSION\",
-                  \"name\": \"${LFS_VERSION%.0}\",
-                  \"target_commitish\": \"$TRAVIS_COMMIT\",
-                  \"draft\": $DRAFT,
-                  \"body\": $(jq -sR '.' <<< "$CHANGES")
-              }" #"
-          SCRIPT
+      # attempt to migrate
+      - cd ../..
+      - fusermount -u mount

-# Manage statuses
+      - v2/lfs --migrate /dev/loop0
+      - v2/lfs /dev/loop0 mount
+
+      # run self-host test with v2 right where we left off
+      - ls mount
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test
+
+  # automatically create releases
+  - stage: deploy
+    env:
+      - NAME=deploy
+    script:
+      - |
+        bash << 'SCRIPT'
+        set -ev
+        # Find version defined in lfs.h
+        LFS_VERSION=$(grep -ox '#define LFS_VERSION .*' lfs.h | cut -d ' ' -f3)
+        LFS_VERSION_MAJOR=$((0xffff & ($LFS_VERSION >> 16)))
+        LFS_VERSION_MINOR=$((0xffff & ($LFS_VERSION >>  0)))
+        # Grab latests patch from repo tags, default to 0, needs finagling
+        # to get past github's pagination api
+        PREV_URL=https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs/tags/v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.
+        PREV_URL=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" -I \
+            | sed -n '/^Link/{s/.*<\(.*\)>; rel="last"/\1/;p;q0};$q1' \
+            || echo $PREV_URL)
+        LFS_VERSION_PATCH=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" \
+            | jq 'map(.ref | match("\\bv.*\\..*\\.(.*)$";"g")
+                .captures[].string | tonumber) | max + 1' \
+            || echo 0)
+        # We have our new version
+        LFS_VERSION="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.$LFS_VERSION_PATCH"
+        echo "VERSION $LFS_VERSION"
+        # Check that we're the most recent commit
+        CURRENT_COMMIT=$(curl -f -u "$GEKY_BOT_RELEASES" \
+            https://api.github.com/repos/$TRAVIS_REPO_SLUG/commits/master \
+            | jq -re '.sha')
+        [ "$TRAVIS_COMMIT" == "$CURRENT_COMMIT" ] || exit 0
+        # Create major branch
+        git branch v$LFS_VERSION_MAJOR HEAD
+        # Create major prefix branch
+        git config user.name "geky bot"
+        git config user.email "bot@geky.net"
+        git fetch https://github.com/$TRAVIS_REPO_SLUG.git \
+            --depth=50 v$LFS_VERSION_MAJOR-prefix || true
+        ./scripts/prefix.py lfs$LFS_VERSION_MAJOR
+        git branch v$LFS_VERSION_MAJOR-prefix $( \
+            git commit-tree $(git write-tree) \
+                $(git rev-parse --verify -q FETCH_HEAD | sed -e 's/^/-p /') \
+                -p HEAD \
+                -m "Generated v$LFS_VERSION_MAJOR prefixes")
+        git reset --hard
+        # Update major version branches (vN and vN-prefix)
+        git push --atomic https://$GEKY_BOT_RELEASES@github.com/$TRAVIS_REPO_SLUG.git \
+            v$LFS_VERSION_MAJOR \
+            v$LFS_VERSION_MAJOR-prefix
+        # Build release notes
+        PREV=$(git tag --sort=-v:refname -l "v*" | head -1)
+        if [ ! -z "$PREV" ]
+        then
+            echo "PREV $PREV"
+            CHANGES=$(git log --oneline $PREV.. --grep='^Merge' --invert-grep)
+            printf "CHANGES\n%s\n\n" "$CHANGES"
+        fi
+        case ${GEKY_BOT_DRAFT:-minor} in
+            true)  DRAFT=true ;;
+            minor) DRAFT=$(jq -R 'endswith(".0")' <<< "$LFS_VERSION") ;;
+            false) DRAFT=false ;;
+        esac
+        # Create the release and patch version tag (vN.N.N)
+        curl -f -u "$GEKY_BOT_RELEASES" -X POST \
+            https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases \
+            -d "{
+                \"tag_name\": \"$LFS_VERSION\",
+                \"name\": \"${LFS_VERSION%.0}\",
+                \"target_commitish\": \"$TRAVIS_COMMIT\",
+                \"draft\": $DRAFT,
+                \"body\": $(jq -sR '.' <<< "$CHANGES")
+            }" #"
+        SCRIPT
+
+# manage statuses
 before_install:
  - |
-    curl -u "$GEKY_BOT_STATUSES" -X POST \
-        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        -d "{
-            \"context\": \"$STAGE/$NAME\",
-            \"state\": \"pending\",
-            \"description\": \"${STATUS:-In progress}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
-        }"
+    # don't clobber other (not us) failures
+    if ! curl https://api.github.com/repos/$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:-$TRAVIS_COMMIT} \
+            -d "{
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
+                \"state\": \"pending\",
+                \"description\": \"${STATUS:-In progress}\",
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
+            }"
+    fi

 after_failure:
  - |
-    curl -u "$GEKY_BOT_STATUSES" -X POST \
-        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        -d "{
-            \"context\": \"$STAGE/$NAME\",
-            \"state\": \"failure\",
-            \"description\": \"${STATUS:-Failed}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
-        }"
+    # don't clobber other (not us) failures
+    if ! curl https://api.github.com/repos/$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:-$TRAVIS_COMMIT} \
+            -d "{
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
+                \"state\": \"failure\",
+                \"description\": \"${STATUS:-Failed}\",
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
+            }"
+    fi

 after_success:
  - |
-    curl -u "$GEKY_BOT_STATUSES" -X POST \
-        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
-        -d "{
-            \"context\": \"$STAGE/$NAME\",
-            \"state\": \"success\",
-            \"description\": \"${STATUS:-Passed}\",
-            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
-        }"
-
-# Job control
-stages:
-    - name: test
-    - name: deploy
-      if: branch = master AND type = push
+    # don't clobber other (not us) failures
+    # only update if we were last job to mark in progress,
+    # this isn't perfect but is probably good enough
+    if ! curl https://api.github.com/repos/$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:-$TRAVIS_COMMIT} \
+            -d "{
+                \"context\": \"${TRAVIS_BUILD_STAGE_NAME,,}/$NAME\",
+                \"state\": \"success\",
+                \"description\": \"${STATUS:-Passed}\",
+                \"target_url\": \"$TRAVIS_JOB_WEB_URL#$TRAVIS_JOB_NUMBER\"
+            }"
+    fi
--- a/lfs.c
+++ b/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;
    }

@@ -173,7 +173,7 @@ 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 +269,7 @@ 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);
@@ -714,7 +714,7 @@ 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,
@@ -748,6 +748,12 @@ 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;
@@ -774,7 +780,7 @@ 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};
@@ -782,7 +788,7 @@ 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) {
@@ -853,7 +859,7 @@ static lfs_stag_t lfs_dir_fetchmatch(lfs_t *lfs,
                dir->split = tempsplit;

                // reset crc
-                crc = LFS_BLOCK_NULL;
+                crc = 0xffffffff;
                continue;
            }

@@ -1231,14 +1237,14 @@ static int lfs_dir_commitattr(lfs_t *lfs, struct lfs_commit *commit,
 }

 static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
+    const lfs_off_t off1 = commit->off;
+    const uint32_t crc1 = commit->crc;
    // 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(off1 + 2*sizeof(uint32_t),
            lfs->cfg->prog_size);
-    uint32_t ncrc = commit->crc;

    // 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);
@@ -1248,7 +1254,7 @@ 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));
@@ -1272,10 +1278,9 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
            return err;
        }

-        ncrc = 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
@@ -1286,10 +1291,16 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {

    // successful commit, check checksums to make sure
    lfs_off_t off = commit->begin;
-    lfs_off_t noff = off1;
+    lfs_off_t noff = off1 + sizeof(uint32_t);
    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,
@@ -1299,12 +1310,6 @@ static int lfs_dir_commitcrc(lfs_t *lfs, struct lfs_commit *commit) {
                return err;
            }

-            // check against written crc to detect if block is readonly
-            // (we may pick up old commits)
-            if (i == noff && crc != ncrc) {
-                return LFS_ERR_CORRUPT;
-            }
-
            crc = lfs_crc(crc, &dat, 1);
        }

@@ -1351,7 +1356,7 @@ 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;
@@ -1445,7 +1450,7 @@ static int lfs_dir_compact(lfs_t *lfs,
        // 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,
@@ -1540,8 +1545,8 @@ 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,
@@ -1570,7 +1575,7 @@ 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,
@@ -1747,7 +1752,7 @@ 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,
@@ -2198,7 +2203,6 @@ static int lfs_ctz_find(lfs_t *lfs,
            return err;
        }

-        LFS_ASSERT(head >= 2 && head <= lfs->cfg->block_count);
        current -= 1 << skip;
    }

@@ -2218,7 +2222,6 @@ 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);
@@ -2291,8 +2294,6 @@ static int lfs_ctz_extend(lfs_t *lfs,
                        return err;
                    }
                }
-
-                LFS_ASSERT(nhead >= 2 && nhead <= lfs->cfg->block_count);
            }

            *block = nblock;
@@ -2708,6 +2709,12 @@ 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);

+    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;
@@ -2716,7 +2723,6 @@ 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;
@@ -3445,7 +3451,7 @@ 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.
@@ -3658,7 +3664,15 @@ 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),
@@ -3800,7 +3814,14 @@ int lfs_fs_traverseraw(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) {
@@ -3884,7 +3905,14 @@ static int lfs_fs_pred(lfs_t *lfs,
    // 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;
        }
@@ -3927,9 +3955,14 @@ 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;
-    int i = 0;
+    lfs_block_t cycle = 0;
    while (!lfs_pair_isnull(parent->tail)) {
-        i += 1;
+        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),
@@ -4372,7 +4405,7 @@ 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);
@@ -4808,7 +4841,7 @@ 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];
--- a/scripts/explode_asserts.py
+++ b/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:
--- a/scripts/readmdir.py
+++ b/scripts/readmdir.py
@@ -318,6 +318,14 @@ def main(args):

    # find most recent pair
    mdir = MetadataPair(blocks)
+    print("mdir {%s} rev %d%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 ''))
    if args.all:
        mdir.dump_all(truncate=not args.no_truncate)
    elif args.log:
--- a/scripts/readtree.py
+++ b/scripts/readtree.py
@@ -18,26 +18,22 @@ def dumpentries(args, mdir, f):
        name = mdir[Tag('name', id_, 0)]
        struct_ = mdir[Tag('struct', id_, 0)]

-        f.write("id %d %s %s" % (
+        desc = "id %d %s %s" % (
            id_, name.typerepr(),
-            json.dumps(name.data.decode('utf8'))))
+            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')))
+            desc += " 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')))
+            desc += " 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")
+            desc += " inline size %d" % struct_.size

-        if args.data and struct_.is_('inlinestruct'):
-            for i in range(0, len(struct_.data), 16):
-                f.write("  %08x: %-47s  %-16s\n" % (
-                    i, ' '.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'):
+        data = None
+        if struct_.is_('inlinestruct'):
+            data = struct_.data
+        elif struct_.is_('ctzstruct'):
            block, size = struct.unpack(
                '<II', struct_.data[:8].ljust(8, b'\xff'))
            data = []
@@ -51,28 +47,50 @@ def dumpentries(args, mdir, f):
                    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("%-45s%s\n" % (desc,
+            "%-23s  %-8s" % (
+                ' '.join('%02x' % c for c in data[:8]),
+                ''.join(c if c >= ' ' and c <= '~' else '.'
+                    for c in map(chr, data[:8])))
+            if not args.no_truncate and len(desc) < 45
+                and data is not None else ""))
+
+        if name.is_('superblock') and struct_.is_('inlinestruct'):
+            f.write(
+                "  block_size %d\n"
+                "  block_count %d\n"
+                "  name_max %d\n"
+                "  file_max %d\n"
+                "  attr_max %d\n" % struct.unpack(
+                    '<IIIII', struct_.data[4:4+20].ljust(20, b'\xff')))
+
+        for tag in mdir.tags:
+            if tag.id==id_ and tag.is_('userattr'):
+                desc = "%s size %d" % (tag.typerepr(), tag.size)
+                f.write("  %-43s%s\n" % (desc,
+                    "%-23s  %-8s" % (
+                        ' '.join('%02x' % c for c in tag.data[:8]),
+                        ''.join(c if c >= ' ' and c <= '~' else '.'
+                            for c in map(chr, tag.data[:8])))
+                    if not args.no_truncate and len(desc) < 43 else ""))
+
+                if args.no_truncate:
+                    for i in range(0, len(tag.data), 16):
+                        f.write("    %08x: %-47s  %-16s\n" % (
+                            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]))))
+
+        if args.no_truncate and data is not None:
+            for i in range(0, len(data), 16):
                f.write("  %08x: %-47s  %-16s\n" % (
                    i, ' '.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 = []
@@ -161,61 +179,51 @@ def main(args):
        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
+    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.tags, 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:
+    if 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:
-        for i, dir in enumerate(dirs):
-            print("dir %s" % (json.dumps(dir[0].path)
-                if hasattr(dir[0], 'path') else '(orphan)'))
+    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 ''))
+        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 ''))

-                f = io.StringIO()
-                if args.tags:
-                    mdir.dump_tags(f, truncate=not args.no_truncate)
-                elif 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)
+            f = io.StringIO()
+            if args.tags:
+                mdir.dump_tags(f, truncate=not args.no_truncate)
+            elif 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)

-                lines = list(filter(None, f.getvalue().split('\n')))
-                for k, line in enumerate(lines):
-                    print("%s %s" % (
-                        ' ' if j == len(dir)-1 else
-                        'v' if k == len(lines)-1 else
-                        '|',
-                        line))
+            lines = list(filter(None, f.getvalue().split('\n')))
+            for k, line in enumerate(lines):
+                print("%s %s" % (
+                    ' ' if i == len(dirs)-1 and j == len(dir)-1 else
+                    'v' if k == len(lines)-1 else
+                    '.' if j == len(dir)-1 else
+                    '|',
+                    line))

    if cycle:
        print("*** cycle detected! -> {%#x, %#x} ***" % (cycle[0], cycle[1]))
@@ -242,20 +250,12 @@ if __name__ == "__main__":
    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('-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('-d', '--data', action='store_true',
-        help="Also show the raw contents of files/attrs/tags.")
    parser.add_argument('-T', '--no-truncate', action='store_true',
-        help="Don't truncate large amounts of data.")
+        help="Show the full contents of files/attrs/tags.")
    sys.exit(main(parser.parse_args()))
--- a/scripts/test.py
+++ b/scripts/test.py
@@ -184,7 +184,8 @@ class TestCase:
        elif self.if_ is not None:
            if_ = self.if_
            while True:
-                for k, v in self.defines.items():
+                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
@@ -199,22 +200,25 @@ class TestCase:
            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:
@@ -295,11 +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):
@@ -310,7 +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':
@@ -376,10 +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))
@@ -702,8 +713,6 @@ def main(**args):
                        stdout = perm.result.stdout[:-1]
                    else:
                        stdout = perm.result.stdout
-                    if (not args.get('verbose', False) and len(stdout) > 5):
-                        sys.stdout.write('...\n')
                    for line in stdout[-5:]:
                        sys.stdout.write(line)
                if perm.result.assert_:
@@ -764,4 +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())))
--- a/tests/test_alloc.toml
+++ b/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"};
--- a/tests/test_badblocks.toml
+++ b/tests/test_badblocks.toml
@@ -1,3 +1,6 @@
+# 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
--- a/tests/test_dirs.toml
+++ b/tests/test_dirs.toml
@@ -155,7 +155,7 @@ code = '''
 '''

 [[case]] # reentrant many directory creation/rename/removal
-define.N = [5, 10] # TODO changed from 20, should we be able to do more?
+define.N = [5, 11]
 reentrant = true
 code = '''
    err = lfs_mount(&lfs, &cfg);
--- a/tests/test_entries.toml
+++ b/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 = '''
--- a/tests/test_evil.toml
+++ b/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;
+'''
--- a/tests/test_exhaustion.toml
+++ b/tests/test_exhaustion.toml
@@ -33,6 +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;
                }
            }
@@ -40,6 +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;
            }
        }
@@ -111,6 +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;
                }
            }
@@ -118,6 +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;
            }
        }
@@ -198,6 +206,9 @@ 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;
                    }
                }
@@ -205,6 +216,7 @@ 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;
                }
            }
@@ -283,6 +295,9 @@ 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;
                    }
                }
@@ -290,6 +305,7 @@ 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;
                }
            }
@@ -338,9 +354,9 @@ exhausted:
 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.LFS_BLOCK_CYCLES = [4, 2]
 define.CYCLES = 100
 define.FILES = 10
+if = 'LFS_BLOCK_CYCLES < CYCLES/10'
 code = '''
    lfs_format(&lfs, &cfg) => 0;
    lfs_mount(&lfs, &cfg) => 0;
@@ -364,6 +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;
                }
            }
@@ -371,6 +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;
            }
        }
--- a/tests/test_move.toml
+++ b/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;
--- a/tests/test_new.toml
+++ b/tests/test_new.toml
@@ -0,0 +1,85 @@
+
+#open(1, "5file5.xxxxxxxxxxxx", 0x503) -> 0
+#  write(1, , 2007)[^ 1499 us] -> 2007
+#  write(1, , 2007)[^ 1411 us] -> 2007
+#  write(1, , 2007)[^ 1390 us] -> 2007
+#  write(1, , 2007)[^ 1401 us] -> 2007
+#  close(1) -> 0
+#  open(1, "1file1.xxxx", 0x503) -> 0
+#  mount
+#  open(0, "5file5.xxxxxxxxxxxx", 0x3) -> 0
+#  open(1, "5file5.xxxxxxxxxxxx", 0x503) -> 0
+#  close(1) -> 0
+#  open(1, "1file1.xxxx", 0x2) -> 0
+#  write(0, , 63) -> 63
+#a.out: lfs.c:2169: lfs_ctz_find: Assertion `head >= 2 && head <= lfs->cfg->block_count' failed.
+#  close(0)Aborted
+
+[[case]]
+define.FILESIZE5 = '4*CHUNKSIZE5'
+define.FILESIZE1 = '4*CHUNKSIZE1'
+define.CHUNKSIZE5 = 2007
+define.CHUNKSIZE1 = 63
+code = '''
+    lfs_file_t files[2];
+    uint8_t chunk5[CHUNKSIZE5];
+    memset(chunk5, 'a', CHUNKSIZE5);
+    uint8_t chunk1[CHUNKSIZE1];
+    memset(chunk1, 'b', CHUNKSIZE1);
+
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &files[1], "5file5.xxxxxxxxxxxx",
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+    for (int i = 0; i < FILESIZE5/CHUNKSIZE5; i++) {
+        lfs_file_write(&lfs, &files[1], chunk5, CHUNKSIZE5) => CHUNKSIZE5;
+    }
+    lfs_file_close(&lfs, &files[1]) => 0;
+    lfs_file_open(&lfs, &files[1], "1file1.xxxx",
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+//  these should not change the result
+//    lfs_file_close(&lfs, &files[1]) => 0;
+//    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &files[0], "5file5.xxxxxxxxxxxx",
+            LFS_O_RDWR) => 0;
+
+    lfs_file_open(&lfs, &files[1], "5file5.xxxxxxxxxxxx",
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_TRUNC) => 0;
+    lfs_file_close(&lfs, &files[1]) => 0;
+
+    lfs_file_open(&lfs, &files[1], "1file1.xxxx",
+            LFS_O_WRONLY) => 0;
+    for (int i = 0; i < FILESIZE1/CHUNKSIZE1; i++) {
+        lfs_file_write(&lfs, &files[1], chunk1, CHUNKSIZE1) => CHUNKSIZE1;
+    }
+    lfs_file_close(&lfs, &files[1]) => 0;
+
+    memset(chunk5, 'c', CHUNKSIZE5);
+    for (int i = 0; i < FILESIZE5/CHUNKSIZE5; i++) {
+        lfs_file_write(&lfs, &files[0], chunk5, CHUNKSIZE5) => CHUNKSIZE5;
+    }
+    lfs_file_close(&lfs, &files[0]) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // check results
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &files[0], "5file5.xxxxxxxxxxxx",
+            LFS_O_RDONLY) => 0;
+    for (int i = 0; i < FILESIZE5/CHUNKSIZE5; i++) {
+        uint8_t rchunk[CHUNKSIZE5];
+        lfs_file_read(&lfs, &files[0], rchunk, CHUNKSIZE5) => CHUNKSIZE5;
+        assert(memcmp(rchunk, chunk5, CHUNKSIZE5) == 0);
+    }
+    lfs_file_close(&lfs, &files[0]) => 0;
+    lfs_file_open(&lfs, &files[0], "1file1.xxxx",
+            LFS_O_RDONLY) => 0;
+    for (int i = 0; i < FILESIZE1/CHUNKSIZE1; i++) {
+        uint8_t rchunk[CHUNKSIZE1];
+        lfs_file_read(&lfs, &files[0], rchunk, CHUNKSIZE1) => CHUNKSIZE1;
+        assert(memcmp(rchunk, chunk1, CHUNKSIZE1) == 0);
+    }
+    lfs_file_close(&lfs, &files[0]) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
--- a/tests/test_orphans.toml
+++ b/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;
--- a/tests/test_paths.toml
+++ b/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;
--- a/tests/test_superblocks.toml
+++ b/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));
-        
-        lfs_mkdir(&lfs, "dummy") => 0;
+        if (!err) {
+            assert(strcmp(info.name, "dummy") == 0);
+            assert(info.type == LFS_TYPE_REG);
+            lfs_remove(&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));
-        
-        lfs_mkdir(&lfs, "dummy") => 0;
+        if (!err) {
+            assert(strcmp(info.name, "dummy") == 0);
+            assert(info.type == LFS_TYPE_REG);
+            lfs_remove(&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;
 '''
--- a/tests/test_truncate.toml
+++ b/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;