Introduced the LFS_O_SNAPSHOT flag

LFS_O_SNAPSHOT brings back some of littlefs's idiosyncratic behavior
removed in the changes to open file syncing in a form that may be more
useful for users.

LFS_O_SNAPSHOT allows you to open a "snapshot" of a file. This is a cheap,
local copy of a file who's changes are not reflected on disk.

Internally, snapshot files use the same mechanism as pending writes. A
separate, copy-on-write CTZ skip-list is created, with read-only
references to the existing data blocks until a write occurs. The
difference is that snapshot files are not enrolled in the mlist, meaning
they won't get updates from open file syncs, and during close their
contents are simply discarded.

As an extra benefit, LFS_O_CREAT | LFS_O_SNAPSHOT is equivalent to
Linux's O_TMPFILE, making it easy to create temporary, unnamed files.

This may be useful for embedded development, where unnamed flash-backed
buffers may provide a slower, but larger, alternative to RAM-backed
buffers.

.github/workflows/post-release.yml

@@ -1,26 +0,0 @@
-name: post-release
-on:
-  release:
-    branches: [master]
-    types: [released]
-
-jobs:
-  post-release:
-    runs-on: ubuntu-18.04
-    steps:
-      # trigger post-release in dependency repo, this indirection allows the
-      # dependency repo to be updated often without affecting this repo. At
-      # the time of this comment, the dependency repo is responsible for
-      # creating PRs for other dependent repos post-release.
-      - name: trigger-post-release
-        continue-on-error: true
-        run: |
-          curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
-            "$GITHUB_API_URL/repos/${{secrets.POST_RELEASE_REPO}}/dispatches" \
-            -d "$(jq -n '{
-              event_type: "post-release",
-              client_payload: {
-                repo: env.GITHUB_REPOSITORY,
-                version: "${{github.event.release.tag_name}}"}}' \
-              | tee /dev/stderr)"
-

.github/workflows/release.yml

@@ -1,215 +0,0 @@
-name: release
-on:
-  workflow_run:
-    workflows: [test]
-    branches: [master]
-    types: [completed]
-
-jobs:
-  release:
-    runs-on: ubuntu-18.04
-
-    # need to manually check for a couple things
-    # - tests passed?
-    # - we are the most recent commit on master?
-    if: ${{github.event.workflow_run.conclusion == 'success' &&
-      github.event.workflow_run.head_sha == github.sha}}
-
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          ref: ${{github.event.workflow_run.head_sha}}
-          # need workflow access since we push branches
-          # containing workflows
-          token: ${{secrets.BOT_TOKEN}}
-          # need all tags
-          fetch-depth: 0
-
-      # try to get results from tests
-      - uses: dawidd6/action-download-artifact@v2
-        continue-on-error: true
-        with:
-          workflow: ${{github.event.workflow_run.name}}
-          run_id: ${{github.event.workflow_run.id}}
-          name: results
-          path: results
-
-      - name: find-version
-        run: |
-          # rip version from lfs.h
-          LFS_VERSION="$(grep -o '^#define LFS_VERSION .*$' lfs.h \
-            | awk '{print $3}')"
-          LFS_VERSION_MAJOR="$((0xffff & ($LFS_VERSION >> 16)))"
-          LFS_VERSION_MINOR="$((0xffff & ($LFS_VERSION >>  0)))"
-
-          # find a new patch version based on what we find in our tags
-          LFS_VERSION_PATCH="$( \
-            ( git describe --tags --abbrev=0 \
-                --match="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.*" \
-              || echo 'v0.0.-1' ) \
-            | awk -F '.' '{print $3+1}')"
-
-          # found new version
-          LFS_VERSION="v$LFS_VERSION_MAJOR`
-            `.$LFS_VERSION_MINOR`
-            `.$LFS_VERSION_PATCH"
-          echo "LFS_VERSION=$LFS_VERSION"
-          echo "LFS_VERSION=$LFS_VERSION" >> $GITHUB_ENV
-          echo "LFS_VERSION_MAJOR=$LFS_VERSION_MAJOR" >> $GITHUB_ENV
-          echo "LFS_VERSION_MINOR=$LFS_VERSION_MINOR" >> $GITHUB_ENV
-          echo "LFS_VERSION_PATCH=$LFS_VERSION_PATCH" >> $GITHUB_ENV
-
-      # try to find previous version?
-      - name: find-prev-version
-        continue-on-error: true
-        run: |
-          LFS_PREV_VERSION="$(git describe --tags --abbrev=0 --match 'v*')"
-          echo "LFS_PREV_VERSION=$LFS_PREV_VERSION"
-          echo "LFS_PREV_VERSION=$LFS_PREV_VERSION" >> $GITHUB_ENV
-
-      # try to find results from tests
-      - name: collect-results
-        run: |
-          # previous results to compare against?
-          [ -n "$LFS_PREV_VERSION" ] && curl -sS \
-            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/`
-              `status/$LFS_PREV_VERSION" \
-            | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]' \
-            >> prev-results.json \
-            || true
-
-          # unfortunately these each have their own format
-          [ -e results/code-thumb.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / code").description
-                  | capture("Code size is (?<result>[0-9]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/code.py -u results/code-thumb.csv -s | awk '
-              NR==2 {printf "Code size,%d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-          [ -e results/code-thumb-readonly.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / code (readonly)").description
-                  | capture("Code size is (?<result>[0-9]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/code.py -u results/code-thumb-readonly.csv -s | awk '
-              NR==2 {printf "Code size<br/>(readonly),%d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-          [ -e results/code-thumb-threadsafe.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / code (threadsafe)").description
-                  | capture("Code size is (?<result>[0-9]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/code.py -u results/code-thumb-threadsafe.csv -s | awk '
-              NR==2 {printf "Code size<br/>(threadsafe),%d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-          [ -e results/code-thumb-migrate.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / code (migrate)").description
-                  | capture("Code size is (?<result>[0-9]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/code.py -u results/code-thumb-migrate.csv -s | awk '
-              NR==2 {printf "Code size<br/>(migrate),%d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-          [ -e results/code-thumb-error-asserts.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / code (error-asserts)").description
-                  | capture("Code size is (?<result>[0-9]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/code.py -u results/code-thumb-error-asserts.csv -s | awk '
-              NR==2 {printf "Code size<br/>(error-asserts),%d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-          [ -e results/coverage.csv ] && ( \
-            export PREV="$(jq -re '
-                  select(.context == "results / coverage").description
-                  | capture("Coverage is (?<result>[0-9\\.]+)").result' \
-                prev-results.json || echo 0)"
-            ./scripts/coverage.py -u results/coverage.csv -s | awk -F '[ /%]+' '
-              NR==2 {printf "Coverage,%.1f%% of %d lines",$4,$3}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",$4-ENVIRON["PREV"]}
-              NR==2 {printf "\n"}' \
-            >> results.csv)
-
-          # transpose to GitHub table
-          [ -e results.csv ] || exit 0
-          awk -F ',' '
-            {label[NR]=$1; value[NR]=$2}
-            END {
-              for (r=1; r<=NR; r++) {printf "| %s ",label[r]}; printf "|\n";
-              for (r=1; r<=NR; r++) {printf "|:--"}; printf "|\n";
-              for (r=1; r<=NR; r++) {printf "| %s ",value[r]}; printf "|\n"}' \
-            results.csv > results.txt
-          echo "RESULTS:"
-          cat results.txt
-
-      # find changes from history
-      - name: collect-changes
-        run: |
-          [ -n "$LFS_PREV_VERSION" ] || exit 0
-          # use explicit link to github commit so that release notes can
-          # be copied elsewhere
-          git log "$LFS_PREV_VERSION.." \
-            --grep='^Merge' --invert-grep \
-            --format="format:[\`%h\`](`
-              `https://github.com/$GITHUB_REPOSITORY/commit/%h) %s" \
-            > changes.txt
-          echo "CHANGES:"
-          cat changes.txt
-
-      # create and update major branches (vN and vN-prefix)
-      - name: create-major-branches
-        run: |
-          # create major branch
-          git branch "v$LFS_VERSION_MAJOR" HEAD
-
-          # create major prefix branch
-          git config user.name ${{secrets.BOT_USER}}
-          git config user.email ${{secrets.BOT_EMAIL}}
-          git fetch "https://github.com/$GITHUB_REPOSITORY.git" \
-            "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
-
-          # push!
-          git push --atomic origin \
-            "v$LFS_VERSION_MAJOR" \
-            "v$LFS_VERSION_MAJOR-prefix"
-
-      # build release notes
-      - name: create-release
-        run: |
-          # create release and patch version tag (vN.N.N)
-          # only draft if not a patch release
-          [ -e results.txt ] && export RESULTS="$(cat results.txt)"
-          [ -e changes.txt ] && export CHANGES="$(cat changes.txt)"
-          curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
-            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/releases" \
-            -d "$(jq -n '{
-              tag_name: env.LFS_VERSION,
-              name: env.LFS_VERSION | rtrimstr(".0"),
-              target_commitish: "${{github.event.workflow_run.head_sha}}",
-              draft: env.LFS_VERSION | endswith(".0"),
-              body: [env.RESULTS, env.CHANGES | select(.)] | join("\n\n")}' \
-              | tee /dev/stderr)"
-

.github/workflows/status.yml

@@ -1,55 +0,0 @@
-name: status
-on:
-  workflow_run:
-    workflows: [test]
-    types: [completed]
-
-jobs:
-  status:
-    runs-on: ubuntu-18.04
-    steps:
-      # custom statuses?
-      - uses: dawidd6/action-download-artifact@v2
-        continue-on-error: true
-        with:
-          workflow: ${{github.event.workflow_run.name}}
-          run_id: ${{github.event.workflow_run.id}}
-          name: status
-          path: status
-      - name: update-status
-        continue-on-error: true
-        run: |
-          ls status
-          for s in $(shopt -s nullglob ; echo status/*.json)
-          do
-            # parse requested status
-            export STATE="$(jq -er '.state' $s)"
-            export CONTEXT="$(jq -er '.context' $s)"
-            export DESCRIPTION="$(jq -er '.description' $s)"
-            # help lookup URL for job/steps because GitHub makes
-            # it VERY HARD to link to specific jobs
-            export TARGET_URL="$(
-              jq -er '.target_url // empty' $s || (
-                export TARGET_JOB="$(jq -er '.target_job' $s)"
-                export TARGET_STEP="$(jq -er '.target_step // ""' $s)"
-                curl -sS -H "authorization: token ${{secrets.BOT_TOKEN}}" \
-                  "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/actions/runs/`
-                    `${{github.event.workflow_run.id}}/jobs" \
-                  | jq -er '.jobs[]
-                    | select(.name == env.TARGET_JOB)
-                    | .html_url
-                      + "?check_suite_focus=true"
-                      + ((.steps[]
-                        | select(.name == env.TARGET_STEP)
-                        | "#step:\(.number):0") // "")'))"
-            # update status
-            curl -sS -X POST -H "authorization: token ${{secrets.BOT_TOKEN}}" \
-              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/statuses/`
-                `${{github.event.workflow_run.head_sha}}" \
-              -d "$(jq -n '{
-                state: env.STATE,
-                context: env.CONTEXT,
-                description: env.DESCRIPTION,
-                target_url: env.TARGET_URL}' \
-                | tee /dev/stderr)"
-          done

.github/workflows/test.yml

@@ -1,446 +0,0 @@
-name: test
-on: [push, pull_request]
-
-env:
-  CFLAGS: -Werror
-  MAKEFLAGS: -j
-
-jobs:
-  # run tests
-  test:
-    runs-on: ubuntu-18.04
-    strategy:
-      fail-fast: false
-      matrix:
-        arch: [x86_64, thumb, mips, powerpc]
-
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          # need toml, also pip3 isn't installed by default?
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip lcov
-          sudo pip3 install toml
-          gcc --version
-
-          # setup a ram-backed disk to speed up reentrant tests
-          mkdir disks
-          sudo mount -t tmpfs -o size=100m tmpfs disks
-          TESTFLAGS="$TESTFLAGS --disk=disks/disk"
-
-          # collect coverage
-          mkdir -p coverage
-          TESTFLAGS="$TESTFLAGS --coverage=`
-            `coverage/${{github.job}}-${{matrix.arch}}.info"
-
-          echo "TESTFLAGS=$TESTFLAGS" >> $GITHUB_ENV
-
-      # cross-compile with ARM Thumb (32-bit, little-endian)
-      - name: install-thumb
-        if: ${{matrix.arch == 'thumb'}}
-        run: |
-          sudo apt-get install -qq \
-            gcc-arm-linux-gnueabi \
-            libc6-dev-armel-cross \
-            qemu-user
-          echo "CC=arm-linux-gnueabi-gcc -mthumb --static" >> $GITHUB_ENV
-          echo "EXEC=qemu-arm" >> $GITHUB_ENV
-          arm-linux-gnueabi-gcc --version
-          qemu-arm -version
-      # cross-compile with MIPS (32-bit, big-endian)
-      - name: install-mips
-        if: ${{matrix.arch == 'mips'}}
-        run: |
-          sudo apt-get install -qq \
-            gcc-mips-linux-gnu \
-            libc6-dev-mips-cross \
-            qemu-user
-          echo "CC=mips-linux-gnu-gcc --static" >> $GITHUB_ENV
-          echo "EXEC=qemu-mips" >> $GITHUB_ENV
-          mips-linux-gnu-gcc --version
-          qemu-mips -version
-      # cross-compile with PowerPC (32-bit, big-endian)
-      - name: install-powerpc
-        if: ${{matrix.arch == 'powerpc'}}
-        run: |
-          sudo apt-get install -qq \
-            gcc-powerpc-linux-gnu \
-            libc6-dev-powerpc-cross \
-            qemu-user
-          echo "CC=powerpc-linux-gnu-gcc --static" >> $GITHUB_ENV
-          echo "EXEC=qemu-ppc" >> $GITHUB_ENV
-          powerpc-linux-gnu-gcc --version
-          qemu-ppc -version
-
-      # make sure example can at least compile
-      - name: test-example
-        run: |
-          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"
-          rm test.c
-
-      # test configurations
-      # normal+reentrant tests
-      - name: test-default
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk"
-      # NOR flash: read/prog = 1 block = 4KiB
-      - name: test-nor
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_READ_SIZE=1 -DLFS_BLOCK_SIZE=4096"
-      # SD/eMMC: read/prog = 512 block = 512
-      - name: test-emmc
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_READ_SIZE=512 -DLFS_BLOCK_SIZE=512"
-      # NAND flash: read/prog = 4KiB block = 32KiB
-      - name: test-nand
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_READ_SIZE=4096 -DLFS_BLOCK_SIZE=\(32*1024\)"
-      # other extreme geometries that are useful for various corner cases
-      - name: test-no-intrinsics
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_NO_INTRINSICS"
-      - name: test-byte-writes
-        # it just takes too long to test byte-level writes when in qemu,
-        # should be plenty covered by the other configurations
-        if: ${{matrix.arch == 'x86_64'}}
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_READ_SIZE=1 -DLFS_CACHE_SIZE=1"
-      - name: test-block-cycles
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_BLOCK_CYCLES=1"
-      - name: test-odd-block-count
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_BLOCK_COUNT=1023 -DLFS_LOOKAHEAD_SIZE=256"
-      - name: test-odd-block-size
-        run: |
-          make clean
-          make test TESTFLAGS+="-nrk \
-            -DLFS_READ_SIZE=11 -DLFS_BLOCK_SIZE=704"
-
-      # upload coverage for later coverage
-      - name: upload-coverage
-        uses: actions/upload-artifact@v2
-        with:
-          name: coverage
-          path: coverage
-          retention-days: 1
-
-      # update results
-      - name: results-code
-        run: |
-          mkdir -p results
-          make clean
-          make code \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR" \
-            CODEFLAGS+="-o results/code-${{matrix.arch}}.csv"
-      - name: results-code-readonly
-        run: |
-          mkdir -p results
-          make clean
-          make code \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_READONLY" \
-            CODEFLAGS+="-o results/code-${{matrix.arch}}-readonly.csv"
-      - name: results-code-threadsafe
-        run: |
-          mkdir -p results
-          make clean
-          make code \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_THREADSAFE" \
-            CODEFLAGS+="-o results/code-${{matrix.arch}}-threadsafe.csv"
-      - name: results-code-migrate
-        run: |
-          mkdir -p results
-          make clean
-          make code \
-            CFLAGS+=" \
-              -DLFS_NO_ASSERT \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -DLFS_MIGRATE" \
-            CODEFLAGS+="-o results/code-${{matrix.arch}}-migrate.csv"
-      - name: results-code-error-asserts
-        run: |
-          mkdir -p results
-          make clean
-          make code \
-            CFLAGS+=" \
-              -DLFS_NO_DEBUG \
-              -DLFS_NO_WARN \
-              -DLFS_NO_ERROR \
-              -D'LFS_ASSERT(test)=do {if(!(test)) {return -1;}} while(0)'" \
-            CODEFLAGS+="-o results/code-${{matrix.arch}}-error-asserts.csv"
-      - name: upload-results
-        uses: actions/upload-artifact@v2
-        with:
-          name: results
-          path: results
-      # limit reporting to Thumb, otherwise there would be too many numbers
-      # flying around for the results to be easily readable
-      - name: collect-status
-        if: ${{matrix.arch == 'thumb'}}
-        run: |
-          mkdir -p status
-          for f in $(shopt -s nullglob ; echo results/code*.csv)
-          do
-            export STEP="results-code$(
-              echo $f | sed -n 's/.*code-.*-\(.*\).csv/-\1/p')"
-            export CONTEXT="results / code$(
-              echo $f | sed -n 's/.*code-.*-\(.*\).csv/ (\1)/p')"
-            export PREV="$(curl -sS \
-              "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/master" \
-              | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]
-                | select(.context == env.CONTEXT).description
-                | capture("Code size is (?<result>[0-9]+)").result' \
-              || echo 0)"
-            export DESCRIPTION="$(./scripts/code.py -u $f -s | awk '
-              NR==2 {printf "Code size is %d B",$2}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",100*($2-ENVIRON["PREV"])/ENVIRON["PREV"]}')"
-            jq -n '{
-              state: "success",
-              context: env.CONTEXT,
-              description: env.DESCRIPTION,
-              target_job: "${{github.job}} (${{matrix.arch}})",
-              target_step: env.STEP}' \
-              | tee status/code$(
-                echo $f | sed -n 's/.*code-.*-\(.*\).csv/-\1/p').json
-          done
-      - name: upload-status
-        if: ${{matrix.arch == 'thumb'}}
-        uses: actions/upload-artifact@v2
-        with:
-          name: status
-          path: status
-          retention-days: 1
-
-  # run under Valgrind to check for memory errors
-  valgrind:
-    runs-on: ubuntu-18.04
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          # need toml, also pip3 isn't installed by default?
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip
-          sudo pip3 install toml
-      - name: install-valgrind
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -qq valgrind
-          valgrind --version
-      # normal tests, we don't need to test all geometries
-      - name: test-valgrind
-        run: make test TESTFLAGS+="-k --valgrind"
-
-  # self-host with littlefs-fuse for a fuzz-like test
-  fuse:
-    runs-on: ubuntu-18.04
-    if: ${{!endsWith(github.ref, '-prefix')}}
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          # need toml, also pip3 isn't installed by default?
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip libfuse-dev
-          sudo pip3 install toml
-          fusermount -V
-          gcc --version
-      - uses: actions/checkout@v2
-        with:
-          repository: littlefs-project/littlefs-fuse
-          ref: v2
-          path: littlefs-fuse
-      - name: setup
-        run: |
-          # copy our new version into littlefs-fuse
-          rm -rf littlefs-fuse/littlefs/*
-          cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs
-
-          # setup disk for littlefs-fuse
-          mkdir mount
-          sudo chmod a+rw /dev/loop0
-          dd if=/dev/zero bs=512 count=128K of=disk
-          losetup /dev/loop0 disk
-      - name: test
-        run: |
-          # self-host test
-          make -C littlefs-fuse
-
-          littlefs-fuse/lfs --format /dev/loop0
-          littlefs-fuse/lfs /dev/loop0 mount
-
-          ls mount
-          mkdir mount/littlefs
-          cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-          cd mount/littlefs
-          stat .
-          ls -flh
-          make -B test
-
-  # test migration using littlefs-fuse
-  migrate:
-    runs-on: ubuntu-18.04
-    if: ${{!endsWith(github.ref, '-prefix')}}
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          # need toml, also pip3 isn't installed by default?
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip libfuse-dev
-          sudo pip3 install toml
-          fusermount -V
-          gcc --version
-      - uses: actions/checkout@v2
-        with:
-          repository: littlefs-project/littlefs-fuse
-          ref: v2
-          path: v2
-      - uses: actions/checkout@v2
-        with:
-          repository: littlefs-project/littlefs-fuse
-          ref: v1
-          path: v1
-      - name: setup
-        run: |
-          # copy our new version into littlefs-fuse
-          rm -rf v2/littlefs/*
-          cp -r $(git ls-tree --name-only HEAD) v2/littlefs
-
-          # setup disk for littlefs-fuse
-          mkdir mount
-          sudo chmod a+rw /dev/loop0
-          dd if=/dev/zero bs=512 count=128K of=disk
-          losetup /dev/loop0 disk
-      - name: test
-        run: |
-          # compile v1 and v2
-          make -C v1
-          make -C v2
-
-          # run self-host test with v1
-          v1/lfs --format /dev/loop0
-          v1/lfs /dev/loop0 mount
-
-          ls mount
-          mkdir mount/littlefs
-          cp -r $(git ls-tree --name-only HEAD) mount/littlefs
-          cd mount/littlefs
-          stat .
-          ls -flh
-          make -B test
-
-          # attempt to migrate
-          cd ../..
-          fusermount -u mount
-
-          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
-
-  # collect coverage info
-  coverage:
-    runs-on: ubuntu-18.04
-    needs: [test]
-    steps:
-      - uses: actions/checkout@v2
-      - name: install
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -qq python3 python3-pip lcov
-          sudo pip3 install toml
-      # yes we continue-on-error nearly every step, continue-on-error
-      # at job level apparently still marks a job as failed, which isn't
-      # what we want
-      - uses: actions/download-artifact@v2
-        continue-on-error: true
-        with:
-          name: coverage
-          path: coverage
-      - name: results-coverage
-        continue-on-error: true
-        run: |
-          mkdir -p results
-          lcov $(for f in coverage/*.info ; do echo "-a $f" ; done) \
-            -o results/coverage.info
-          ./scripts/coverage.py results/coverage.info -o results/coverage.csv
-      - name: upload-results
-        uses: actions/upload-artifact@v2
-        with:
-          name: results
-          path: results
-      - name: collect-status
-        run: |
-          mkdir -p status
-          [ -e results/coverage.csv ] || exit 0
-          export STEP="results-coverage"
-          export CONTEXT="results / coverage"
-          export PREV="$(curl -sS \
-            "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/status/master" \
-            | jq -re 'select(.sha != env.GITHUB_SHA) | .statuses[]
-              | select(.context == env.CONTEXT).description
-              | capture("Coverage is (?<result>[0-9\\.]+)").result' \
-            || echo 0)"
-          export DESCRIPTION="$(
-            ./scripts/coverage.py -u results/coverage.csv -s | awk -F '[ /%]+' '
-              NR==2 {printf "Coverage is %.1f%% of %d lines",$4,$3}
-              NR==2 && ENVIRON["PREV"]+0 != 0 {
-                printf " (%+.1f%%)",$4-ENVIRON["PREV"]}')"
-          jq -n '{
-            state: "success",
-            context: env.CONTEXT,
-            description: env.DESCRIPTION,
-            target_job: "${{github.job}}",
-            target_step: env.STEP}' \
-            | tee status/coverage.json
-      - name: upload-status
-        uses: actions/upload-artifact@v2
-        with:
-          name: status
-          path: status
-          retention-days: 1

.travis.yml

@@ -0,0 +1,461 @@
+# environment variables
+env:
+  global:
+    - CFLAGS=-Werror
+    - MAKEFLAGS=-j
+
+# 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 &&
+    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"
+
+# report size 
+_: &report-size
+  # compile and find the code size with the smallest configuration
+  - 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 ]
+    then
+        CURR=$(tail -n1 sizes | awk '{print $1}')
+        PREV=$(curl -u "$GEKY_BOT_STATUSES" https://api.github.com/repos/$TRAVIS_REPO_SLUG/status/master \
+            | jq -re "select(.sha != \"$TRAVIS_COMMIT\")
+                | .statuses[] | select(.context == \"${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
+            STATUS="$STATUS ($(python -c "print '%+.2f' % (100*($CURR-$PREV)/$PREV.0)")%)"
+        fi
+    fi
+
+# stage control
+stages:
+  - name: test
+  - name: deploy
+    if: branch = master AND type = push
+
+# job control
+jobs:
+  # native testing
+  - &x86
+    stage: test
+    env:
+      - NAME=littlefs-x86
+    install: *install-common
+    script: [*test-example, *report-size]
+  - {<<: *x86, script: [*test-default,          *report-size]}
+  - {<<: *x86, script: [*test-nor,              *report-size]}
+  - {<<: *x86, script: [*test-emmc,             *report-size]}
+  - {<<: *x86, script: [*test-nand,             *report-size]}
+  - {<<: *x86, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *x86, script: [*test-no-inline,        *report-size]}
+  - {<<: *x86, script: [*test-byte-writes,      *report-size]}
+  - {<<: *x86, script: [*test-block-cycles,     *report-size]}
+  - {<<: *x86, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *x86, script: [*test-odd-block-size,   *report-size]}
+
+  # cross-compile with ARM (thumb mode)
+  - &arm
+    stage: test
+    env:
+      - NAME=littlefs-arm
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - TFLAGS="$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 MIPS
+  - &mips
+    stage: test
+    env:
+      - NAME=littlefs-mips
+      - CC="mips-linux-gnu-gcc --static"
+      - TFLAGS="$TFLAGS --exec=qemu-mips"
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-mips-linux-gnu
+            libc6-dev-mips-cross
+            qemu-user
+      - mips-linux-gnu-gcc --version
+      - qemu-mips -version
+    script: [*test-example, *report-size]
+  - {<<: *mips, script: [*test-default,          *report-size]}
+  - {<<: *mips, script: [*test-nor,              *report-size]}
+  - {<<: *mips, script: [*test-emmc,             *report-size]}
+  - {<<: *mips, script: [*test-nand,             *report-size]}
+  - {<<: *mips, script: [*test-no-intrinsics,    *report-size]}
+  - {<<: *mips, script: [*test-no-inline,        *report-size]}
+  # it just takes way to long to run byte-level writes in qemu,
+  # note this is still tested in the native tests
+  #- {<<: *mips, script: [*test-byte-writes,      *report-size]}
+  - {<<: *mips, script: [*test-block-cycles,     *report-size]}
+  - {<<: *mips, script: [*test-odd-block-count,  *report-size]}
+  - {<<: *mips, script: [*test-odd-block-size,   *report-size]}
+
+  # cross-compile with PowerPC
+  - &powerpc
+    stage: test
+    env:
+      - NAME=littlefs-powerpc
+      - CC="powerpc-linux-gnu-gcc --static"
+      - TFLAGS="$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"
+
+  # test compilation in read-only mode
+  - stage: test
+    env:
+      - NAME=littlefs-readonly
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - CFLAGS="-Werror -DLFS_READONLY"
+    if: branch !~ -prefix$
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-arm-linux-gnueabi
+            libc6-dev-armel-cross
+      - arm-linux-gnueabi-gcc --version
+    # report-size will compile littlefs and report the size
+    script: [*report-size]
+
+  # test compilation in thread-safe mode
+  - stage: test
+    env:
+      - NAME=littlefs-threadsafe
+      - CC="arm-linux-gnueabi-gcc --static -mthumb"
+      - CFLAGS="-Werror -DLFS_THREADSAFE"
+    if: branch !~ -prefix$
+    install:
+      - *install-common
+      - sudo apt-get install
+            gcc-arm-linux-gnueabi
+            libc6-dev-armel-cross
+      - arm-linux-gnueabi-gcc --version
+    # report-size will compile littlefs and report the size
+    script: [*report-size]
+
+  # 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
+
+      # 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=128K of=disk
+      - losetup /dev/loop0 disk
+    script:
+      # self-host test
+      - make -C littlefs-fuse
+
+      - littlefs-fuse/lfs --format /dev/loop0
+      - littlefs-fuse/lfs /dev/loop0 mount
+
+      - ls mount
+      - mkdir mount/littlefs
+      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test
+
+  # test migration using littlefs-fuse
+  - stage: test
+    env:
+      - NAME=littlefs-migration
+    if: branch !~ -prefix$
+    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
+
+      # 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=128K of=disk
+      - losetup /dev/loop0 disk
+    script:
+      # compile v1 and v2
+      - make -C v1
+      - make -C v2
+
+      # run self-host test with v1
+      - v1/lfs --format /dev/loop0
+      - v1/lfs /dev/loop0 mount
+
+      - ls mount
+      - mkdir mount/littlefs
+      - cp -r $(git ls-tree --name-only HEAD) mount/littlefs
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test
+
+      # attempt to migrate
+      - cd ../..
+      - fusermount -u mount
+
+      - v2/lfs --migrate /dev/loop0
+      - v2/lfs /dev/loop0 mount
+
+      # run self-host test with v2 right where we left off
+      - ls mount
+      - cd mount/littlefs
+      - stat .
+      - ls -flh
+      - make -B test
+
+  # automatically create releases
+  - stage: deploy
+    env:
+      - NAME=deploy
+    script:
+      - |
+        bash << 'SCRIPT'
+        set -ev
+        # Find version defined in lfs.h
+        LFS_VERSION=$(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:
+  - |
+    # 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#$TRAVIS_JOB_NUMBER\"
+            }"
+    fi
+
+after_failure:
+  - |
+    # don't clobber other (not us) failures
+    if ! curl https://api.github.com/repos/$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:
+  - |
+    # 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

Makefile

@@ -1,39 +1,25 @@
-ifdef BUILDDIR
-# make sure BUILDDIR ends with a slash
-override BUILDDIR := $(BUILDDIR)/
-# bit of a hack, but we want to make sure BUILDDIR directory structure
-# is correct before any commands
-$(if $(findstring n,$(MAKEFLAGS)),, $(shell mkdir -p \
-	$(BUILDDIR) \
-	$(BUILDDIR)bd \
-	$(BUILDDIR)tests))
-endif
-
-# overridable target/src/tools/flags/etc
+TARGET = lfs.a
 ifneq ($(wildcard test.c main.c),)
-TARGET ?= $(BUILDDIR)lfs
-else
-TARGET ?= $(BUILDDIR)lfs.a
+override TARGET = lfs
 endif
 
-
 CC ?= gcc
 AR ?= ar
 SIZE ?= size
-CTAGS ?= ctags
-NM ?= nm
-LCOV ?= lcov
 
-SRC ?= $(wildcard *.c)
-OBJ := $(SRC:%.c=$(BUILDDIR)%.o)
-DEP := $(SRC:%.c=$(BUILDDIR)%.d)
-ASM := $(SRC:%.c=$(BUILDDIR)%.s)
+SRC += $(wildcard *.c bd/*.c)
+OBJ := $(SRC:.c=.o)
+DEP := $(SRC:.c=.d)
+ASM := $(SRC:.c=.s)
 
 ifdef DEBUG
 override CFLAGS += -O0 -g3
 else
 override CFLAGS += -Os
 endif
+ifdef WORD
+override CFLAGS += -m$(WORD)
+endif
 ifdef TRACE
 override CFLAGS += -DLFS_YES_TRACE
 endif
@@ -42,73 +28,40 @@ override CFLAGS += -std=c99 -Wall -pedantic
 override CFLAGS += -Wextra -Wshadow -Wjump-misses-init -Wundef
 
 ifdef VERBOSE
-override TESTFLAGS += -v
-override CODEFLAGS += -v
-override COVERAGEFLAGS += -v
-endif
-ifdef EXEC
-override TESTFLAGS += --exec="$(EXEC)"
-endif
-ifdef BUILDDIR
-override TESTFLAGS += --build-dir="$(BUILDDIR:/=)"
-override CODEFLAGS += --build-dir="$(BUILDDIR:/=)"
-endif
-ifneq ($(NM),nm)
-override CODEFLAGS += --nm-tool="$(NM)"
+override TFLAGS += -v
 endif
 
 
-# commands
-.PHONY: all build
-all build: $(TARGET)
+all: $(TARGET)
 
-.PHONY: asm
 asm: $(ASM)
 
-.PHONY: size
 size: $(OBJ)
 	$(SIZE) -t $^
 
-.PHONY: tags
-tags:
-	$(CTAGS) --totals --c-types=+p $(shell find -H -name '*.h') $(SRC)
-
-.PHONY: code
-code: $(OBJ)
-	./scripts/code.py $^ $(CODEFLAGS)
-
-.PHONY: test
 test:
-	./scripts/test.py $(TESTFLAGS)
+	./scripts/test.py $(TFLAGS)
 .SECONDEXPANSION:
 test%: tests/test$$(firstword $$(subst \#, ,%)).toml
-	./scripts/test.py $@ $(TESTFLAGS)
+	./scripts/test.py $@ $(TFLAGS)
 
-.PHONY: coverage
-coverage:
-	./scripts/coverage.py $(BUILDDIR)tests/*.toml.info $(COVERAGEFLAGS)
-
-# rules
 -include $(DEP)
-.SUFFIXES:
 
-$(BUILDDIR)lfs: $(OBJ)
+lfs: $(OBJ)
 	$(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
 
-$(BUILDDIR)%.a: $(OBJ)
+%.a: $(OBJ)
 	$(AR) rcs $@ $^
 
-$(BUILDDIR)%.o: %.c
+%.o: %.c
 	$(CC) -c -MMD $(CFLAGS) $< -o $@
 
-$(BUILDDIR)%.s: %.c
+%.s: %.c
 	$(CC) -S $(CFLAGS) $< -o $@
 
-# clean everything
-.PHONY: clean
 clean:
 	rm -f $(TARGET)
 	rm -f $(OBJ)
 	rm -f $(DEP)
 	rm -f $(ASM)
-	rm -f $(BUILDDIR)tests/*.toml.*
+	rm -f tests/*.toml.*

README.md

@@ -192,7 +192,7 @@ More details on how littlefs works can be found in [DESIGN.md](DESIGN.md) and
 ## Testing
 
 The littlefs comes with a test suite designed to run on a PC using the
-[emulated block device](bd/lfs_testbd.h) found in the `bd` directory.
+[emulated block device](emubd/lfs_emubd.h) found in the emubd directory.
 The tests assume a Linux environment and can be started with make:
 
 ``` bash

SPEC.md

@@ -233,19 +233,19 @@ Metadata tag fields:
    into a 3-bit abstract type and an 8-bit chunk field. Note that the value
    `0x000` is invalid and not assigned a type.
 
-    1. **Type1 (3-bits)** - Abstract type of the tag. Groups the tags into
-       8 categories that facilitate bitmasked lookups.
+3. **Type1 (3-bits)** - Abstract type of the tag. Groups the tags into
+   8 categories that facilitate bitmasked lookups.
 
-    2. **Chunk (8-bits)** - Chunk field used for various purposes by the different
-       abstract types.  type1+chunk+id form a unique identifier for each tag in the
-       metadata block.
+4. **Chunk (8-bits)** - Chunk field used for various purposes by the different
+   abstract types.  type1+chunk+id form a unique identifier for each tag in the
+   metadata block.
 
-3. **Id (10-bits)** - File id associated with the tag. Each file in a metadata
+5. **Id (10-bits)** - File id associated with the tag. Each file in a metadata
    block gets a unique id which is used to associate tags with that file. The
    special value `0x3ff` is used for any tags that are not associated with a
    file, such as directory and global metadata.
 
-4. **Length (10-bits)** - Length of the data in bytes. The special value
+6. **Length (10-bits)** - Length of the data in bytes. The special value
    `0x3ff` indicates that this tag has been deleted.
 
 ## Metadata types

bd/lfs_filebd.c

@@ -80,7 +80,7 @@ int lfs_filebd_read(const struct lfs_config *cfg, lfs_block_t block,
     LFS_ASSERT(size % cfg->read_size == 0);
     LFS_ASSERT(block < cfg->block_count);
 
-    // zero for reproducibility (in case file is truncated)
+    // zero for reproducability (in case file is truncated)
     if (bd->cfg->erase_value != -1) {
         memset(buffer, bd->cfg->erase_value, size);
     }

bd/lfs_rambd.c

@@ -32,12 +32,10 @@ int lfs_rambd_createcfg(const struct lfs_config *cfg,
         }
     }
 
-    // zero for reproducibility?
+    // zero for reproducability?
     if (bd->cfg->erase_value != -1) {
         memset(bd->buffer, bd->cfg->erase_value,
                 cfg->block_size * cfg->block_count);
-    } else {
-        memset(bd->buffer, 0, cfg->block_size * cfg->block_count);
     }
 
     LFS_RAMBD_TRACE("lfs_rambd_createcfg -> %d", 0);

lfs.c

@@ -11,7 +11,6 @@
 #define LFS_BLOCK_INLINE ((lfs_block_t)-2)
 
 /// Caching block device operations ///
-
 static inline void lfs_cache_drop(lfs_t *lfs, lfs_cache_t *rcache) {
     // do not zero, cheaper if cache is readonly or only going to be
     // written with identical data (during relocates)
@@ -25,6 +24,14 @@ static inline void lfs_cache_zero(lfs_t *lfs, lfs_cache_t *pcache) {
     pcache->block = LFS_BLOCK_NULL;
 }
 
+static inline void lfs_cache_copy(lfs_t *lfs,
+        lfs_cache_t *dcache, const lfs_cache_t *scache) {
+    memcpy(dcache->buffer, scache->buffer, lfs->cfg->cache_size);
+    dcache->block = scache->block;
+    dcache->off   = scache->off;
+    dcache->size  = scache->size;
+}
+
 static int lfs_bd_read(lfs_t *lfs,
         const lfs_cache_t *pcache, lfs_cache_t *rcache, lfs_size_t hint,
         lfs_block_t block, lfs_off_t off,
@@ -269,26 +276,22 @@ static inline int lfs_pair_cmp(
              paira[0] == pairb[1] || paira[1] == pairb[0]);
 }
 
-#ifndef LFS_READONLY
 static inline bool lfs_pair_sync(
         const lfs_block_t paira[2],
         const lfs_block_t pairb[2]) {
     return (paira[0] == pairb[0] && paira[1] == pairb[1]) ||
            (paira[0] == pairb[1] && paira[1] == pairb[0]);
 }
-#endif
 
 static inline void lfs_pair_fromle32(lfs_block_t pair[2]) {
     pair[0] = lfs_fromle32(pair[0]);
     pair[1] = lfs_fromle32(pair[1]);
 }
 
-#ifndef LFS_READONLY
 static inline void lfs_pair_tole32(lfs_block_t pair[2]) {
     pair[0] = lfs_tole32(pair[0]);
     pair[1] = lfs_tole32(pair[1]);
 }
-#endif
 
 // operations on 32-bit entry tags
 typedef uint32_t lfs_tag_t;
@@ -370,7 +373,6 @@ static inline bool lfs_gstate_iszero(const lfs_gstate_t *a) {
     return true;
 }
 
-#ifndef LFS_READONLY
 static inline bool lfs_gstate_hasorphans(const lfs_gstate_t *a) {
     return lfs_tag_size(a->tag);
 }
@@ -382,7 +384,6 @@ static inline uint8_t lfs_gstate_getorphans(const lfs_gstate_t *a) {
 static inline bool lfs_gstate_hasmove(const lfs_gstate_t *a) {
     return lfs_tag_type1(a->tag);
 }
-#endif
 
 static inline bool lfs_gstate_hasmovehere(const lfs_gstate_t *a,
         const lfs_block_t *pair) {
@@ -395,13 +396,11 @@ static inline void lfs_gstate_fromle32(lfs_gstate_t *a) {
     a->pair[1] = lfs_fromle32(a->pair[1]);
 }
 
-#ifndef LFS_READONLY
 static inline void lfs_gstate_tole32(lfs_gstate_t *a) {
     a->tag     = lfs_tole32(a->tag);
     a->pair[0] = lfs_tole32(a->pair[0]);
     a->pair[1] = lfs_tole32(a->pair[1]);
 }
-#endif
 
 // other endianness operations
 static void lfs_ctz_fromle32(struct lfs_ctz *ctz) {
@@ -425,7 +424,6 @@ static inline void lfs_superblock_fromle32(lfs_superblock_t *superblock) {
     superblock->attr_max    = lfs_fromle32(superblock->attr_max);
 }
 
-#ifndef LFS_READONLY
 static inline void lfs_superblock_tole32(lfs_superblock_t *superblock) {
     superblock->version     = lfs_tole32(superblock->version);
     superblock->block_size  = lfs_tole32(superblock->block_size);
@@ -434,10 +432,8 @@ static inline void lfs_superblock_tole32(lfs_superblock_t *superblock) {
     superblock->file_max    = lfs_tole32(superblock->file_max);
     superblock->attr_max    = lfs_tole32(superblock->attr_max);
 }
-#endif
 
-#ifndef LFS_NO_ASSERT
-static bool lfs_mlist_isopen(struct lfs_mlist *head,
+static inline bool lfs_mlist_isopen(struct lfs_mlist *head,
         struct lfs_mlist *node) {
     for (struct lfs_mlist **p = &head; *p; p = &(*p)->next) {
         if (*p == (struct lfs_mlist*)node) {
@@ -447,9 +443,8 @@ static bool lfs_mlist_isopen(struct lfs_mlist *head,
 
     return false;
 }
-#endif
 
-static void lfs_mlist_remove(lfs_t *lfs, struct lfs_mlist *mlist) {
+static inline void lfs_mlist_remove(lfs_t *lfs, struct lfs_mlist *mlist) {
     for (struct lfs_mlist **p = &lfs->mlist; *p; p = &(*p)->next) {
         if (*p == mlist) {
             *p = (*p)->next;
@@ -458,7 +453,7 @@ static void lfs_mlist_remove(lfs_t *lfs, struct lfs_mlist *mlist) {
     }
 }
 
-static void lfs_mlist_append(lfs_t *lfs, struct lfs_mlist *mlist) {
+static inline void lfs_mlist_append(lfs_t *lfs, struct lfs_mlist *mlist) {
     mlist->next = lfs->mlist;
     lfs->mlist = mlist;
 }
@@ -478,7 +473,7 @@ static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file);
 static int lfs_file_outline(lfs_t *lfs, lfs_file_t *file);
 static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file);
 
-static int lfs_fs_preporphans(lfs_t *lfs, int8_t orphans);
+static void lfs_fs_preporphans(lfs_t *lfs, int8_t orphans);
 static void lfs_fs_prepmove(lfs_t *lfs,
         uint16_t id, const lfs_block_t pair[2]);
 static int lfs_fs_pred(lfs_t *lfs, const lfs_block_t dir[2],
@@ -643,8 +638,6 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
                 return err;
             }
 
-            memset((uint8_t*)gbuffer + diff, 0, gsize - diff);
-
             return tag + gdiff;
         }
     }
@@ -828,8 +821,12 @@ static int lfs_dir_traverse(lfs_t *lfs,
                 return err;
             }
         } else if (lfs_tag_type3(tag) == LFS_FROM_USERATTRS) {
+            const struct lfs_attr *a = buffer;
             for (unsigned i = 0; i < lfs_tag_size(tag); i++) {
-                const struct lfs_attr *a = buffer;
+                if (a[i].size > lfs->attr_max) {
+                    return LFS_ERR_NOSPC;
+                }
+
                 int err = cb(data, LFS_MKTAG(LFS_TYPE_USERATTR + a[i].type,
                         lfs_tag_id(tag) + diff, a[i].size), a[i].buffer);
                 if (err) {
@@ -1093,7 +1090,7 @@ static int lfs_dir_fetch(lfs_t *lfs,
 
 static int lfs_dir_getgstate(lfs_t *lfs, const lfs_mdir_t *dir,
         lfs_gstate_t *gstate) {
-    lfs_gstate_t temp;
+    lfs_gstate_t temp = {0};
     lfs_stag_t res = lfs_dir_get(lfs, dir, LFS_MKTAG(0x7ff, 0, 0),
             LFS_MKTAG(LFS_TYPE_MOVESTATE, 0, sizeof(temp)), &temp);
     if (res < 0 && res != LFS_ERR_NOENT) {
@@ -1119,10 +1116,11 @@ static int lfs_dir_getinfo(lfs_t *lfs, lfs_mdir_t *dir,
     }
 
     lfs_stag_t tag = lfs_dir_get(lfs, dir, LFS_MKTAG(0x780, 0x3ff, 0),
-            LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max+1), info->name);
+            LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max), info->name);
     if (tag < 0) {
         return (int)tag;
     }
+    info->name[lfs_tag_size(tag)] = '\0';
 
     info->type = lfs_tag_type3(tag);
 
@@ -1186,6 +1184,11 @@ static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
     dir->tail[0] = lfs->root[0];
     dir->tail[1] = lfs->root[1];
 
+    // NULL path == root
+    if (!name) {
+        return tag;
+    }
+
     while (true) {
 nextname:
         // skip slashes
@@ -1460,7 +1463,7 @@ static int lfs_dir_alloc(lfs_t *lfs, lfs_mdir_t *dir) {
         }
     }
 
-    // zero for reproducibility in case initial block is unreadable
+    // zero for reproducability in case initial block is unreadable
     dir->rev = 0;
 
     // rather than clobbering one of the blocks we just pretend
@@ -1520,6 +1523,7 @@ static int lfs_dir_split(lfs_t *lfs,
         lfs_mdir_t *dir, const struct lfs_mattr *attrs, int attrcount,
         lfs_mdir_t *source, uint16_t split, uint16_t end) {
     // create tail directory
+    lfs_alloc_ack(lfs);
     lfs_mdir_t tail;
     int err = lfs_dir_alloc(lfs, &tail);
     if (err) {
@@ -1601,8 +1605,7 @@ static int lfs_dir_compact(lfs_t *lfs,
         // for metadata updates.
         if (end - begin < 0xff &&
                 size <= lfs_min(lfs->cfg->block_size - 36,
-                    lfs_alignup((lfs->cfg->metadata_max ?
-                            lfs->cfg->metadata_max : lfs->cfg->block_size)/2,
+                    lfs_alignup(lfs->cfg->block_size/2,
                         lfs->cfg->prog_size))) {
             break;
         }
@@ -1687,8 +1690,7 @@ static int lfs_dir_compact(lfs_t *lfs,
                 .crc = 0xffffffff,
 
                 .begin = 0,
-                .end = (lfs->cfg->metadata_max ?
-                    lfs->cfg->metadata_max : lfs->cfg->block_size) - 8,
+                .end = lfs->cfg->block_size - 8,
             };
 
             // erase block to write to
@@ -1835,7 +1837,7 @@ relocate:
 #ifndef LFS_READONLY
 static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
         const struct lfs_mattr *attrs, int attrcount) {
-    // check for any inline files that aren't RAM backed and
+    // check for any open inline files that aren't RAM backed and
     // forcefully evict them, needed for filesystem consistency
     for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
         if (dir != &f->m && lfs_pair_cmp(f->m.pair, dir->pair) == 0 &&
@@ -1898,8 +1900,7 @@ static int lfs_dir_commit(lfs_t *lfs, lfs_mdir_t *dir,
             .crc = 0xffffffff,
 
             .begin = dir->off,
-            .end = (lfs->cfg->metadata_max ?
-                lfs->cfg->metadata_max : lfs->cfg->block_size) - 8,
+            .end = lfs->cfg->block_size - 8,
         };
 
         // traverse attrs that need to be written out
@@ -2028,6 +2029,7 @@ compact:
 #ifndef LFS_READONLY
 static int lfs_rawmkdir(lfs_t *lfs, const char *path) {
     // deorphan if we haven't yet, needed at most once after poweron
+    LFS_ASSERT(path);
     int err = lfs_fs_forceconsistency(lfs);
     if (err) {
         return err;
@@ -2076,10 +2078,7 @@ static int lfs_rawmkdir(lfs_t *lfs, const char *path) {
     // current block end of list?
     if (cwd.m.split) {
         // update tails, this creates a desync
-        err = lfs_fs_preporphans(lfs, +1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, +1);
 
         // it's possible our predecessor has to be relocated, and if
         // our parent is our predecessor's predecessor, this could have
@@ -2099,10 +2098,7 @@ static int lfs_rawmkdir(lfs_t *lfs, const char *path) {
         }
 
         lfs->mlist = cwd.next;
-        err = lfs_fs_preporphans(lfs, -1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, -1);
     }
 
     // now insert into our parent block
@@ -2471,14 +2467,14 @@ static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
         const struct lfs_file_config *cfg) {
 #ifndef LFS_READONLY
     // deorphan if we haven't yet, needed at most once after poweron
-    if ((flags & LFS_O_WRONLY) == LFS_O_WRONLY) {
+    if (flags & LFS_O_WRONLY) {
         int err = lfs_fs_forceconsistency(lfs);
         if (err) {
             return err;
         }
     }
 #else
-    LFS_ASSERT((flags & LFS_O_RDONLY) == LFS_O_RDONLY);
+    LFS_ASSERT(flags & LFS_O_RDONLY);
 #endif
 
     // setup simple file details
@@ -2489,7 +2485,7 @@ static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
     file->off = 0;
     file->cache.buffer = NULL;
 
-    // allocate entry for file if it doesn't exist
+    // find path
     lfs_stag_t tag = lfs_dir_find(lfs, &file->m, &path, &file->id);
     if (tag < 0 && !(tag == LFS_ERR_NOENT && file->id != 0x3ff)) {
         err = tag;
@@ -2497,19 +2493,22 @@ static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
     }
 
     // get id, add to list of mdirs to catch update changes
-    file->type = LFS_TYPE_REG;
-    lfs_mlist_append(lfs, (struct lfs_mlist *)file);
+    if (!(flags & LFS_O_SNAPSHOT)) {
+        file->type = LFS_TYPE_REG;
+        lfs_mlist_append(lfs, (struct lfs_mlist *)file);
+    }
 
-#ifdef LFS_READONLY
-    if (tag == LFS_ERR_NOENT) {
-        err = LFS_ERR_NOENT;
+#ifndef LFS_READONLY
+    if ((flags & LFS_O_CREAT) && (flags & LFS_O_SNAPSHOT) &&
+            (tag == LFS_ERR_NOENT || lfs_tag_type3(tag) != LFS_TYPE_REG)) {
+        // special case for "temporary" files
+        tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, 0);
+    } else if ((flags & LFS_O_EXCL) && tag != LFS_ERR_NOENT) {
+        err = LFS_ERR_EXIST;
         goto cleanup;
-#else
-    if (tag == LFS_ERR_NOENT) {
-        if (!(flags & LFS_O_CREAT)) {
-            err = LFS_ERR_NOENT;
-            goto cleanup;
-        }
+    } else if ((flags & LFS_O_CREAT) && tag == LFS_ERR_NOENT) {
+        // allocate entry for file if it doesn't exist
+        LFS_ASSERT(path);
 
         // check that name fits
         lfs_size_t nlen = strlen(path);
@@ -2522,63 +2521,57 @@ static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
         err = lfs_dir_commit(lfs, &file->m, LFS_MKATTRS(
                 {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), NULL}));
+                {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0), NULL},
+                {LFS_MKTAG(LFS_FROM_USERATTRS, file->id,
+                    file->cfg->attr_count), file->cfg->attrs}));
         if (err) {
-            err = LFS_ERR_NAMETOOLONG;
             goto cleanup;
         }
 
         tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, 0);
-    } else if (flags & LFS_O_EXCL) {
-        err = LFS_ERR_EXIST;
+    } else /**/
+#endif     /**/
+    /*********/
+    /**/ if (tag == LFS_ERR_NOENT) {
+        err = LFS_ERR_NOENT;
         goto cleanup;
-#endif
     } else if (lfs_tag_type3(tag) != LFS_TYPE_REG) {
         err = LFS_ERR_ISDIR;
         goto cleanup;
-#ifndef LFS_READONLY
-    } else if (flags & LFS_O_TRUNC) {
-        // truncate if requested
-        tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, file->id, 0);
-        file->flags |= LFS_F_DIRTY;
-#endif
     } else {
-        // try to load what's on disk, if it's inlined we'll fix it later
-        tag = lfs_dir_get(lfs, &file->m, LFS_MKTAG(0x700, 0x3ff, 0),
-                LFS_MKTAG(LFS_TYPE_STRUCT, file->id, 8), &file->ctz);
-        if (tag < 0) {
-            err = tag;
-            goto cleanup;
-        }
-        lfs_ctz_fromle32(&file->ctz);
-    }
-
-    // fetch attrs
-    for (unsigned i = 0; i < file->cfg->attr_count; i++) {
-        // if opened for read / read-write operations
-        if ((file->flags & LFS_O_RDONLY) == LFS_O_RDONLY) {
-            lfs_stag_t res = lfs_dir_get(lfs, &file->m,
-                    LFS_MKTAG(0x7ff, 0x3ff, 0),
-                    LFS_MKTAG(LFS_TYPE_USERATTR + file->cfg->attrs[i].type,
-                        file->id, file->cfg->attrs[i].size),
-                        file->cfg->attrs[i].buffer);
-            if (res < 0 && res != LFS_ERR_NOENT) {
-                err = res;
-                goto cleanup;
-            }
-        }
-
 #ifndef LFS_READONLY
-        // if opened for write / read-write operations
-        if ((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY) {
-            if (file->cfg->attrs[i].size > lfs->attr_max) {
-                err = LFS_ERR_NOSPC;
+        if (flags & LFS_O_TRUNC) {
+            // truncate if requested
+            // always mark dirty in case we have custom attributes
+            tag = LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, 0);
+            file->flags |= LFS_F_DIRTY;
+        } else /**/
+#endif  /*********/
+        /**/ {
+            // try to load what's on disk, if it's inlined we'll fix it later
+            tag = lfs_dir_get(lfs, &file->m, LFS_MKTAG(0x700, 0x3ff, 0),
+                    LFS_MKTAG(LFS_TYPE_STRUCT, file->id, 8), &file->ctz);
+            if (tag < 0) {
+                err = tag;
                 goto cleanup;
             }
-
-            file->flags |= LFS_F_DIRTY;
+            lfs_ctz_fromle32(&file->ctz);
+        }
+
+        // fetch attrs if opened for read / read-write operations
+        if (flags & LFS_O_RDONLY) {
+            for (lfs_size_t i = 0; i < file->cfg->attr_count; i++) {
+                lfs_stag_t res = lfs_dir_get(lfs, &file->m,
+                        LFS_MKTAG(0x7ff, 0x3ff, 0),
+                        LFS_MKTAG(LFS_TYPE_USERATTR + file->cfg->attrs[i].type,
+                            file->id, file->cfg->attrs[i].size),
+                            file->cfg->attrs[i].buffer);
+                if (res < 0 && res != LFS_ERR_NOENT) {
+                    err = res;
+                    goto cleanup;
+                }
+            }
         }
-#endif
     }
 
     // allocate buffer if needed
@@ -2623,7 +2616,7 @@ static int lfs_file_rawopencfg(lfs_t *lfs, lfs_file_t *file,
 cleanup:
     // clean up lingering resources
 #ifndef LFS_READONLY
-    file->flags |= LFS_F_ERRED;
+    file->flags |= LFS_F_ZOMBIE;
 #endif
     lfs_file_rawclose(lfs, file);
     return err;
@@ -2637,10 +2630,9 @@ static int lfs_file_rawopen(lfs_t *lfs, lfs_file_t *file,
 }
 
 static int lfs_file_rawclose(lfs_t *lfs, lfs_file_t *file) {
-#ifndef LFS_READONLY
-    int err = lfs_file_rawsync(lfs, file);
-#else
     int err = 0;
+#ifndef LFS_READONLY
+    err = lfs_file_rawsync(lfs, file);
 #endif
 
     // remove from list of mdirs
@@ -2740,6 +2732,7 @@ static int lfs_file_outline(lfs_t *lfs, lfs_file_t *file) {
 }
 #endif
 
+#ifndef LFS_READONLY
 static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
     if (file->flags & LFS_F_READING) {
         if (!(file->flags & LFS_F_INLINE)) {
@@ -2748,7 +2741,6 @@ static int lfs_file_flush(lfs_t *lfs, lfs_file_t *file) {
         file->flags &= ~LFS_F_READING;
     }
 
-#ifndef LFS_READONLY
     if (file->flags & LFS_F_WRITING) {
         lfs_off_t pos = file->pos;
 
@@ -2815,24 +2807,28 @@ relocate:
 
         file->pos = pos;
     }
-#endif
 
     return 0;
 }
+#endif
 
 #ifndef LFS_READONLY
 static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file) {
-    if (file->flags & LFS_F_ERRED) {
+    if (file->flags & LFS_F_ZOMBIE) {
         // it's not safe to do anything if our file errored
         return 0;
     }
 
     int err = lfs_file_flush(lfs, file);
     if (err) {
-        file->flags |= LFS_F_ERRED;
+        file->flags |= LFS_F_ZOMBIE;
         return err;
     }
 
+    if (file->flags & LFS_O_SNAPSHOT) {
+        // we do flush snapshot files, but we don't commit, so stop here
+        return 0;
+    }
 
     if ((file->flags & LFS_F_DIRTY) &&
             !lfs_pair_isnull(file->m.pair)) {
@@ -2862,10 +2858,41 @@ static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file) {
                 {LFS_MKTAG(LFS_FROM_USERATTRS, file->id,
                     file->cfg->attr_count), file->cfg->attrs}));
         if (err) {
-            file->flags |= LFS_F_ERRED;
+            file->flags |= LFS_F_ZOMBIE;
             return err;
         }
 
+        // update readable handles referencing this file device-side
+        for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
+            if (f != file &&
+                    f->type == LFS_TYPE_REG &&
+                    lfs_pair_cmp(f->m.pair, file->m.pair) == 0 &&
+                    f->id == file->id &&
+                    // only readable handles because wronly files
+                    // may reference attributes in ROM
+                    (f->flags & LFS_O_RDONLY)) {
+                // sync disk structure
+                f->ctz = file->ctz;
+                // copying the cache is required for inline files
+                lfs_cache_copy(lfs, &f->cache, &file->cache);
+
+                // sync attrs
+                for (lfs_size_t i = 0; i < f->cfg->attr_count; i++) {
+                    for (lfs_size_t j = 0; j < file->cfg->attr_count; j++) {
+                        if (f->cfg->attrs[i].type == file->cfg->attrs[i].type) {
+                            memcpy(f->cfg->attrs[i].buffer,
+                                    file->cfg->attrs[i].buffer,
+                                    lfs_min(
+                                        f->cfg->attrs[i].size,
+                                        file->cfg->attrs[i].size));
+                        }
+                    }
+                }
+
+                f->flags &= ~(LFS_F_DIRTY | LFS_F_WRITING | LFS_F_READING);
+            }
+        }
+
         file->flags &= ~LFS_F_DIRTY;
     }
 
@@ -2875,7 +2902,7 @@ static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file) {
 
 static lfs_ssize_t lfs_file_rawread(lfs_t *lfs, lfs_file_t *file,
         void *buffer, lfs_size_t size) {
-    LFS_ASSERT((file->flags & LFS_O_RDONLY) == LFS_O_RDONLY);
+    LFS_ASSERT(file->flags & LFS_O_RDONLY);
 
     uint8_t *data = buffer;
     lfs_size_t nsize = size;
@@ -2949,7 +2976,7 @@ static lfs_ssize_t lfs_file_rawread(lfs_t *lfs, lfs_file_t *file,
 #ifndef LFS_READONLY
 static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
         const void *buffer, lfs_size_t size) {
-    LFS_ASSERT((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY);
+    LFS_ASSERT(file->flags & LFS_O_WRONLY);
 
     const uint8_t *data = buffer;
     lfs_size_t nsize = size;
@@ -2987,13 +3014,11 @@ static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
     if ((file->flags & LFS_F_INLINE) &&
             lfs_max(file->pos+nsize, file->ctz.size) >
             lfs_min(0x3fe, lfs_min(
-                lfs->cfg->cache_size,
-                (lfs->cfg->metadata_max ?
-                    lfs->cfg->metadata_max : lfs->cfg->block_size) / 8))) {
+                lfs->cfg->cache_size, lfs->cfg->block_size/8))) {
         // inline file doesn't fit anymore
         int err = lfs_file_outline(lfs, file);
         if (err) {
-            file->flags |= LFS_F_ERRED;
+            file->flags |= LFS_F_ZOMBIE;
             return err;
         }
     }
@@ -3009,7 +3034,7 @@ static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
                             file->ctz.head, file->ctz.size,
                             file->pos-1, &file->block, &file->off);
                     if (err) {
-                        file->flags |= LFS_F_ERRED;
+                        file->flags |= LFS_F_ZOMBIE;
                         return err;
                     }
 
@@ -3023,7 +3048,7 @@ static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
                         file->block, file->pos,
                         &file->block, &file->off);
                 if (err) {
-                    file->flags |= LFS_F_ERRED;
+                    file->flags |= LFS_F_ZOMBIE;
                     return err;
                 }
             } else {
@@ -3043,7 +3068,7 @@ static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
                 if (err == LFS_ERR_CORRUPT) {
                     goto relocate;
                 }
-                file->flags |= LFS_F_ERRED;
+                file->flags |= LFS_F_ZOMBIE;
                 return err;
             }
 
@@ -3051,7 +3076,7 @@ static lfs_ssize_t lfs_file_rawwrite(lfs_t *lfs, lfs_file_t *file,
 relocate:
             err = lfs_file_relocate(lfs, file);
             if (err) {
-                file->flags |= LFS_F_ERRED;
+                file->flags |= LFS_F_ZOMBIE;
                 return err;
             }
         }
@@ -3064,13 +3089,21 @@ relocate:
         lfs_alloc_ack(lfs);
     }
 
-    file->flags &= ~LFS_F_ERRED;
+    file->flags &= ~LFS_F_ZOMBIE;
     return size;
 }
 #endif
 
 static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
         lfs_soff_t off, int whence) {
+#ifndef LFS_READONLY
+    // write out everything beforehand, may be noop if rdonly
+    int err = lfs_file_flush(lfs, file);
+    if (err) {
+        return err;
+    }
+#endif
+
     // find new pos
     lfs_off_t npos = file->pos;
     if (whence == LFS_SEEK_SET) {
@@ -3078,7 +3111,7 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
     } else if (whence == LFS_SEEK_CUR) {
         npos = file->pos + off;
     } else if (whence == LFS_SEEK_END) {
-        npos = lfs_file_rawsize(lfs, file) + off;
+        npos = file->ctz.size + off;
     }
 
     if (npos > lfs->file_max) {
@@ -3086,17 +3119,6 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
         return LFS_ERR_INVAL;
     }
 
-    if (file->pos == npos) {
-        // noop - position has not changed
-        return npos;
-    }
-
-    // write out everything beforehand, may be noop if rdonly
-    int err = lfs_file_flush(lfs, file);
-    if (err) {
-        return err;
-    }
-
     // update pos
     file->pos = npos;
     return npos;
@@ -3104,7 +3126,7 @@ static lfs_soff_t lfs_file_rawseek(lfs_t *lfs, lfs_file_t *file,
 
 #ifndef LFS_READONLY
 static int lfs_file_rawtruncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
-    LFS_ASSERT((file->flags & LFS_O_WRONLY) == LFS_O_WRONLY);
+    LFS_ASSERT(file->flags & LFS_O_WRONLY);
 
     if (size > LFS_FILE_MAX) {
         return LFS_ERR_INVAL;
@@ -3127,22 +3149,21 @@ static int lfs_file_rawtruncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
             return err;
         }
 
-        // need to set pos/block/off consistently so seeking back to
-        // the old position does not get confused
-        file->pos = size;
         file->ctz.head = file->block;
         file->ctz.size = size;
         file->flags |= LFS_F_DIRTY | LFS_F_READING;
     } else if (size > oldsize) {
         // flush+seek if not already at end
-        lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_END);
-        if (res < 0) {
-            return (int)res;
+        if (file->pos != oldsize) {
+            lfs_soff_t res = lfs_file_rawseek(lfs, file, 0, LFS_SEEK_END);
+            if (res < 0) {
+                return (int)res;
+            }
         }
 
         // fill with zeros
         while (file->pos < size) {
-            res = lfs_file_rawwrite(lfs, file, &(uint8_t){0}, 1);
+            lfs_ssize_t res = lfs_file_rawwrite(lfs, file, &(uint8_t){0}, 1);
             if (res < 0) {
                 return (int)res;
             }
@@ -3233,10 +3254,7 @@ static int lfs_rawremove(lfs_t *lfs, const char *path) {
         }
 
         // mark fs as orphaned
-        err = lfs_fs_preporphans(lfs, +1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, +1);
 
         // I know it's crazy but yes, dir can be changed by our parent's
         // commit (if predecessor is child)
@@ -3256,10 +3274,7 @@ static int lfs_rawremove(lfs_t *lfs, const char *path) {
     lfs->mlist = dir.next;
     if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
         // fix orphan
-        err = lfs_fs_preporphans(lfs, -1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, -1);
 
         err = lfs_fs_pred(lfs, dir.m.pair, &cwd);
         if (err) {
@@ -3345,10 +3360,7 @@ static int lfs_rawrename(lfs_t *lfs, const char *oldpath, const char *newpath) {
         }
 
         // mark fs as orphaned
-        err = lfs_fs_preporphans(lfs, +1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, +1);
 
         // I know it's crazy but yes, dir can be changed by our parent's
         // commit (if predecessor is child)
@@ -3391,10 +3403,7 @@ static int lfs_rawrename(lfs_t *lfs, const char *oldpath, const char *newpath) {
     lfs->mlist = prevdir.next;
     if (prevtag != LFS_ERR_NOENT && lfs_tag_type3(prevtag) == LFS_TYPE_DIR) {
         // fix orphan
-        err = lfs_fs_preporphans(lfs, -1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, -1);
 
         err = lfs_fs_pred(lfs, prevdir.m.pair, &newcwd);
         if (err) {
@@ -3463,8 +3472,34 @@ static int lfs_commitattr(lfs_t *lfs, const char *path,
         }
     }
 
-    return lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
+    int err = lfs_dir_commit(lfs, &cwd, LFS_MKATTRS(
             {LFS_MKTAG(LFS_TYPE_USERATTR + type, id, size), buffer}));
+    if (err) {
+        return err;
+    }
+
+    if (lfs_tag_type3(tag) == LFS_TYPE_REG && size != 0x3ff) {
+        // sync attrs with any files open for reading, this follows
+        // the behavior of lfs_file_sync with attributes
+        for (lfs_file_t *f = (lfs_file_t*)lfs->mlist; f; f = f->next) {
+            if (f->type == LFS_TYPE_REG &&
+                    lfs_pair_cmp(f->m.pair, cwd.pair) == 0 &&
+                    f->id == id &&
+                    // only readable handles because wronly files
+                    // may reference attributes in ROM
+                    (f->flags & LFS_O_RDONLY)) {
+                // sync attrs
+                for (lfs_size_t i = 0; i < f->cfg->attr_count; i++) {
+                    if (f->cfg->attrs[i].type == type) {
+                        memcpy(f->cfg->attrs[i].buffer, buffer,
+                                lfs_min(f->cfg->attrs[i].size, size));
+                    }
+                }
+            }
+        }
+    }
+
+    return 0;
 }
 #endif
 
@@ -3575,8 +3610,6 @@ static int lfs_init(lfs_t *lfs, const struct lfs_config *cfg) {
         lfs->attr_max = LFS_ATTR_MAX;
     }
 
-    LFS_ASSERT(lfs->cfg->metadata_max <= lfs->cfg->block_size);
-
     // setup default state
     lfs->root[0] = LFS_BLOCK_NULL;
     lfs->root[1] = LFS_BLOCK_NULL;
@@ -3657,16 +3690,16 @@ static int lfs_rawformat(lfs_t *lfs, const struct lfs_config *cfg) {
             goto cleanup;
         }
 
-        // force compaction to prevent accidentally mounting any
-        // older version of littlefs that may live on disk
-        root.erased = false;
-        err = lfs_dir_commit(lfs, &root, NULL, 0);
+        // sanity check that fetch works
+        err = lfs_dir_fetch(lfs, &root, (const lfs_block_t[2]){0, 1});
         if (err) {
             goto cleanup;
         }
 
-        // sanity check that fetch works
-        err = lfs_dir_fetch(lfs, &root, (const lfs_block_t[2]){0, 1});
+        // force compaction to prevent accidentally mounting any
+        // older version of littlefs that may live on disk
+        root.erased = false;
+        err = lfs_dir_commit(lfs, &root, NULL, 0);
         if (err) {
             goto cleanup;
         }
@@ -4027,10 +4060,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
 
     if (tag != LFS_ERR_NOENT) {
         // update disk, this creates a desync
-        int err = lfs_fs_preporphans(lfs, +1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, +1);
 
         // fix pending move in this pair? this looks like an optimization but
         // is in fact _required_ since relocating may outdate the move.
@@ -4047,7 +4077,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         }
 
         lfs_pair_tole32(newpair);
-        err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
+        int err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
                 {LFS_MKTAG_IF(moveid != 0x3ff,
                     LFS_TYPE_DELETE, moveid, 0), NULL},
                 {tag, newpair}));
@@ -4057,10 +4087,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
         }
 
         // next step, clean up orphans
-        err = lfs_fs_preporphans(lfs, -1);
-        if (err) {
-            return err;
-        }
+        lfs_fs_preporphans(lfs, -1);
     }
 
     // find pred
@@ -4082,7 +4109,7 @@ static int lfs_fs_relocate(lfs_t *lfs,
             lfs_fs_prepmove(lfs, 0x3ff, NULL);
         }
 
-        // replace bad pair, either we clean up desync, or no desync occurred
+        // replace bad pair, either we clean up desync, or no desync occured
         lfs_pair_tole32(newpair);
         err = lfs_dir_commit(lfs, &parent, LFS_MKATTRS(
                 {LFS_MKTAG_IF(moveid != 0x3ff,
@@ -4099,13 +4126,11 @@ static int lfs_fs_relocate(lfs_t *lfs,
 #endif
 
 #ifndef LFS_READONLY
-static int lfs_fs_preporphans(lfs_t *lfs, int8_t orphans) {
+static void lfs_fs_preporphans(lfs_t *lfs, int8_t orphans) {
     LFS_ASSERT(lfs_tag_size(lfs->gstate.tag) > 0 || orphans >= 0);
     lfs->gstate.tag += orphans;
     lfs->gstate.tag = ((lfs->gstate.tag & ~LFS_MKTAG(0x800, 0, 0)) |
             ((uint32_t)lfs_gstate_hasorphans(&lfs->gstate) << 31));
-
-    return 0;
 }
 #endif
 
@@ -4222,7 +4247,8 @@ static int lfs_fs_deorphan(lfs_t *lfs) {
     }
 
     // mark orphans as fixed
-    return lfs_fs_preporphans(lfs, -lfs_gstate_getorphans(&lfs->gstate));
+    lfs_fs_preporphans(lfs, -lfs_gstate_getorphans(&lfs->gstate));
+    return 0;
 }
 #endif
 
@@ -4771,7 +4797,7 @@ static int lfs_rawmigrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
                 lfs1_entry_tole32(&entry1.d);
                 err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
-                        {LFS_MKTAG(LFS_TYPE_CREATE, id, 0), NULL},
+                        {LFS_MKTAG(LFS_TYPE_CREATE, id, 0)},
                         {LFS_MKTAG_IF_ELSE(isdir,
                             LFS_TYPE_DIR, id, entry1.d.nlen,
                             LFS_TYPE_REG, id, entry1.d.nlen),
@@ -4876,7 +4902,7 @@ static int lfs_rawmigrate(lfs_t *lfs, const struct lfs_config *cfg) {
 
         lfs_superblock_tole32(&superblock);
         err = lfs_dir_commit(lfs, &dir2, LFS_MKATTRS(
-                {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0), NULL},
+                {LFS_MKTAG(LFS_TYPE_CREATE, 0, 0)},
                 {LFS_MKTAG(LFS_TYPE_SUPERBLOCK, 0, 8), "littlefs"},
                 {LFS_MKTAG(LFS_TYPE_INLINESTRUCT, 0, sizeof(superblock)),
                     &superblock}));
@@ -5132,7 +5158,8 @@ int lfs_file_close(lfs_t *lfs, lfs_file_t *file) {
         return err;
     }
     LFS_TRACE("lfs_file_close(%p, %p)", (void*)lfs, (void*)file);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     err = lfs_file_rawclose(lfs, file);
 
@@ -5148,7 +5175,8 @@ int lfs_file_sync(lfs_t *lfs, lfs_file_t *file) {
         return err;
     }
     LFS_TRACE("lfs_file_sync(%p, %p)", (void*)lfs, (void*)file);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     err = lfs_file_rawsync(lfs, file);
 
@@ -5166,7 +5194,8 @@ lfs_ssize_t lfs_file_read(lfs_t *lfs, lfs_file_t *file,
     }
     LFS_TRACE("lfs_file_read(%p, %p, %p, %"PRIu32")",
             (void*)lfs, (void*)file, buffer, size);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     lfs_ssize_t res = lfs_file_rawread(lfs, file, buffer, size);
 
@@ -5184,7 +5213,8 @@ lfs_ssize_t lfs_file_write(lfs_t *lfs, lfs_file_t *file,
     }
     LFS_TRACE("lfs_file_write(%p, %p, %p, %"PRIu32")",
             (void*)lfs, (void*)file, buffer, size);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     lfs_ssize_t res = lfs_file_rawwrite(lfs, file, buffer, size);
 
@@ -5202,7 +5232,8 @@ lfs_soff_t lfs_file_seek(lfs_t *lfs, lfs_file_t *file,
     }
     LFS_TRACE("lfs_file_seek(%p, %p, %"PRId32", %d)",
             (void*)lfs, (void*)file, off, whence);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     lfs_soff_t res = lfs_file_rawseek(lfs, file, off, whence);
 
@@ -5219,7 +5250,8 @@ int lfs_file_truncate(lfs_t *lfs, lfs_file_t *file, lfs_off_t size) {
     }
     LFS_TRACE("lfs_file_truncate(%p, %p, %"PRIu32")",
             (void*)lfs, (void*)file, size);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     err = lfs_file_rawtruncate(lfs, file, size);
 
@@ -5235,7 +5267,8 @@ lfs_soff_t lfs_file_tell(lfs_t *lfs, lfs_file_t *file) {
         return err;
     }
     LFS_TRACE("lfs_file_tell(%p, %p)", (void*)lfs, (void*)file);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     lfs_soff_t res = lfs_file_rawtell(lfs, file);
 
@@ -5264,7 +5297,8 @@ lfs_soff_t lfs_file_size(lfs_t *lfs, lfs_file_t *file) {
         return err;
     }
     LFS_TRACE("lfs_file_size(%p, %p)", (void*)lfs, (void*)file);
-    LFS_ASSERT(lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
+    LFS_ASSERT((file->flags & LFS_O_SNAPSHOT) ||
+            lfs_mlist_isopen(lfs->mlist, (struct lfs_mlist*)file));
 
     lfs_soff_t res = lfs_file_rawsize(lfs, file);
 

lfs.h

@@ -22,7 +22,7 @@ extern "C"
 // Software library version
 // Major (top-nibble), incremented on backwards incompatible changes
 // Minor (bottom-nibble), incremented on feature additions
-#define LFS_VERSION 0x00020004
+#define LFS_VERSION 0x00020003
 #define LFS_VERSION_MAJOR (0xffff & (LFS_VERSION >> 16))
 #define LFS_VERSION_MINOR (0xffff & (LFS_VERSION >>  0))
 
@@ -123,26 +123,30 @@ enum lfs_type {
 // File open flags
 enum lfs_open_flags {
     // open flags
-    LFS_O_RDONLY = 1,         // Open a file as read only
+    LFS_O_RDONLY    = 1,        // Open a file as read only
 #ifndef LFS_READONLY
-    LFS_O_WRONLY = 2,         // Open a file as write only
-    LFS_O_RDWR   = 3,         // Open a file as read and write
-    LFS_O_CREAT  = 0x0100,    // Create a file if it does not exist
-    LFS_O_EXCL   = 0x0200,    // Fail if a file already exists
-    LFS_O_TRUNC  = 0x0400,    // Truncate the existing file to zero size
-    LFS_O_APPEND = 0x0800,    // Move to end of file on every write
+    LFS_O_WRONLY    = 2,        // Open a file as write only
+    LFS_O_RDWR      = 3,        // Open a file as read and write
+#endif
+
+#ifndef LFS_READONLY
+    LFS_O_CREAT     = 0x0100,   // Create a file if it does not exist
+    LFS_O_EXCL      = 0x0200,   // Fail if a file already exists
+    LFS_O_TRUNC     = 0x0400,   // Truncate the existing file to zero size
+    LFS_O_APPEND    = 0x0800,   // Move to end of file on every write
+    LFS_O_SNAPSHOT  = 0x1000,   // Open a temporary snapshot, ignore changes
 #endif
 
     // internally used flags
 #ifndef LFS_READONLY
-    LFS_F_DIRTY   = 0x010000, // File does not match storage
-    LFS_F_WRITING = 0x020000, // File has been written since last flush
+    LFS_F_DIRTY     = 0x010000, // File does not match storage
 #endif
-    LFS_F_READING = 0x040000, // File has been read since last flush
+    LFS_F_READING   = 0x020000, // File has been read since last flush
 #ifndef LFS_READONLY
-    LFS_F_ERRED   = 0x080000, // An error occurred during write
+    LFS_F_WRITING   = 0x040000, // File has been written since last flush
+    LFS_F_ZOMBIE    = 0x080000, // An error occurred during write
 #endif
-    LFS_F_INLINE  = 0x100000, // Currently inlined in directory entry
+    LFS_F_INLINE    = 0x100000, // Currently inlined in directory entry
 };
 
 // File seek flags
@@ -159,55 +163,55 @@ struct lfs_config {
     // information to the block device operations
     void *context;
 
-    // Read a region in a block. Negative error codes are propagated
+    // Read a region in a block. Negative error codes are propogated
     // to the user.
     int (*read)(const struct lfs_config *c, lfs_block_t block,
             lfs_off_t off, void *buffer, lfs_size_t size);
 
     // Program a region in a block. The block must have previously
-    // been erased. Negative error codes are propagated to the user.
+    // been erased. Negative error codes are propogated to the user.
     // May return LFS_ERR_CORRUPT if the block should be considered bad.
     int (*prog)(const struct lfs_config *c, lfs_block_t block,
             lfs_off_t off, const void *buffer, lfs_size_t size);
 
     // Erase a block. A block must be erased before being programmed.
     // The state of an erased block is undefined. Negative error codes
-    // are propagated to the user.
+    // are propogated to the user.
     // May return LFS_ERR_CORRUPT if the block should be considered bad.
     int (*erase)(const struct lfs_config *c, lfs_block_t block);
 
     // Sync the state of the underlying block device. Negative error codes
-    // are propagated to the user.
+    // are propogated to the user.
     int (*sync)(const struct lfs_config *c);
 
 #ifdef LFS_THREADSAFE
     // Lock the underlying block device. Negative error codes
-    // are propagated to the user.
+    // are propogated to the user.
     int (*lock)(const struct lfs_config *c);
 
     // Unlock the underlying block device. Negative error codes
-    // are propagated to the user.
+    // are propogated to the user.
     int (*unlock)(const struct lfs_config *c);
 #endif
 
-    // Minimum size of a block read in bytes. All read operations will be a
+    // Minimum size of a block read. All read operations will be a
     // multiple of this value.
     lfs_size_t read_size;
 
-    // Minimum size of a block program in bytes. All program operations will be
-    // a multiple of this value.
+    // Minimum size of a block program. All program operations will be a
+    // multiple of this value.
     lfs_size_t prog_size;
 
-    // Size of an erasable block in bytes. This does not impact ram consumption
-    // and may be larger than the physical erase size. However, non-inlined
-    // files take up at minimum one block. Must be a multiple of the read and
-    // program sizes.
+    // Size of an erasable block. This does not impact ram consumption and
+    // may be larger than the physical erase size. However, non-inlined files
+    // take up at minimum one block. Must be a multiple of the read
+    // and program sizes.
     lfs_size_t block_size;
 
     // Number of erasable blocks on the device.
     lfs_size_t block_count;
 
-    // Number of erase cycles before littlefs evicts metadata logs and moves
+    // Number of erase cycles before littlefs evicts metadata logs and moves 
     // the metadata to another block. Suggested values are in the
     // range 100-1000, with large values having better performance at the cost
     // of less consistent wear distribution.
@@ -215,11 +219,11 @@ struct lfs_config {
     // Set to -1 to disable block-level wear-leveling.
     int32_t block_cycles;
 
-    // Size of block caches in bytes. Each cache buffers a portion of a block in
-    // RAM. The littlefs needs a read cache, a program cache, and one additional
+    // Size of block caches. Each cache buffers a portion of a block in RAM.
+    // The littlefs needs a read cache, a program cache, and one additional
     // cache per file. Larger caches can improve performance by storing more
-    // data and reducing the number of disk accesses. Must be a multiple of the
-    // read and program sizes, and a factor of the block size.
+    // data and reducing the number of disk accesses. Must be a multiple of
+    // the read and program sizes, and a factor of the block size.
     lfs_size_t cache_size;
 
     // Size of the lookahead buffer in bytes. A larger lookahead buffer
@@ -256,12 +260,6 @@ struct lfs_config {
     // larger attributes size but must be <= LFS_ATTR_MAX. Defaults to
     // LFS_ATTR_MAX when zero.
     lfs_size_t attr_max;
-
-    // Optional upper limit on total space given to metadata pairs in bytes. On
-    // devices with large blocks (e.g. 128kB) setting this to a low size (2-8kB)
-    // can help bound the metadata compaction time. Must be <= block_size.
-    // Defaults to block_size when zero.
-    lfs_size_t metadata_max;
 };
 
 // File info structure
@@ -300,16 +298,15 @@ struct lfs_file_config {
     void *buffer;
 
     // Optional list of custom attributes related to the file. If the file
-    // is opened with read access, these attributes will be read from disk
-    // during the open call. If the file is opened with write access, the
-    // attributes will be written to disk every file sync or close. This
-    // write occurs atomically with update to the file's contents.
+    // is opened for reading, these attributes will be read from disk during
+    // open. If the file is open for writing, these attribute will be atomically
+    // written to disk when the file is written to disk. Note that these
+    // attributes are not written unless the file is modified.
     //
     // Custom attributes are uniquely identified by an 8-bit type and limited
-    // to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller
-    // than the buffer, it will be padded with zeros. If the stored attribute
-    // is larger, then it will be silently truncated. If the attribute is not
-    // found, it will be created implicitly.
+    // to LFS_ATTR_MAX bytes. If the stored attribute is larger than the
+    // provided buffer, it will be silently truncated. If no attribute is
+    // found, and the file is open for writing, it will be created implicitly.
     struct lfs_attr *attrs;
 
     // Number of custom attributes in the list
@@ -477,15 +474,14 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
 // Get a custom attribute
 //
 // Custom attributes are uniquely identified by an 8-bit type and limited
-// to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller than
-// the buffer, it will be padded with zeros. If the stored attribute is larger,
-// then it will be silently truncated. If no attribute is found, the error
-// LFS_ERR_NOATTR is returned and the buffer is filled with zeros.
+// to LFS_ATTR_MAX bytes. If the stored attribute is larger than the
+// provided buffer, it will be silently truncated. If no attribute is found,
+// the error LFS_ERR_NOATTR is returned and the buffer is filled with zeros.
 //
 // Returns the size of the attribute, or a negative error code on failure.
 // Note, the returned size is the size of the attribute on disk, irrespective
 // of the size of the buffer. This can be used to dynamically allocate a buffer
-// or check for existence.
+// or check for existance.
 lfs_ssize_t lfs_getattr(lfs_t *lfs, const char *path,
         uint8_t type, void *buffer, lfs_size_t size);
 

lfs_util.h

@@ -49,7 +49,6 @@ extern "C"
 // code footprint
 
 // Logging functions
-#ifndef LFS_TRACE
 #ifdef LFS_YES_TRACE
 #define LFS_TRACE_(fmt, ...) \
     printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -57,9 +56,7 @@ extern "C"
 #else
 #define LFS_TRACE(...)
 #endif
-#endif
 
-#ifndef LFS_DEBUG
 #ifndef LFS_NO_DEBUG
 #define LFS_DEBUG_(fmt, ...) \
     printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -67,9 +64,7 @@ extern "C"
 #else
 #define LFS_DEBUG(...)
 #endif
-#endif
 
-#ifndef LFS_WARN
 #ifndef LFS_NO_WARN
 #define LFS_WARN_(fmt, ...) \
     printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -77,9 +72,7 @@ extern "C"
 #else
 #define LFS_WARN(...)
 #endif
-#endif
 
-#ifndef LFS_ERROR
 #ifndef LFS_NO_ERROR
 #define LFS_ERROR_(fmt, ...) \
     printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
@@ -87,16 +80,13 @@ extern "C"
 #else
 #define LFS_ERROR(...)
 #endif
-#endif
 
 // Runtime assertions
-#ifndef LFS_ASSERT
 #ifndef LFS_NO_ASSERT
 #define LFS_ASSERT(test) assert(test)
 #else
 #define LFS_ASSERT(test)
 #endif
-#endif
 
 
 // Builtin functions, these may be replaced by more efficient

scripts/code.py

@@ -1,214 +0,0 @@
-#!/usr/bin/env python3
-#
-# Script to find code size at the function level. Basically just a bit wrapper
-# around nm with some extra conveniences for comparing builds. Heavily inspired
-# by Linux's Bloat-O-Meter.
-#
-
-import os
-import glob
-import itertools as it
-import subprocess as sp
-import shlex
-import re
-import csv
-import collections as co
-
-
-OBJ_PATHS = ['*.o', 'bd/*.o']
-
-def collect(paths, **args):
-    results = co.defaultdict(lambda: 0)
-    pattern = re.compile(
-        '^(?P<size>[0-9a-fA-F]+)' +
-        ' (?P<type>[%s])' % re.escape(args['type']) +
-        ' (?P<func>.+?)$')
-    for path in paths:
-        # note nm-tool may contain extra args
-        cmd = args['nm_tool'] + ['--size-sort', path]
-        if args.get('verbose'):
-            print(' '.join(shlex.quote(c) for c in cmd))
-        proc = sp.Popen(cmd,
-            stdout=sp.PIPE,
-            stderr=sp.PIPE if not args.get('verbose') else None,
-            universal_newlines=True)
-        for line in proc.stdout:
-            m = pattern.match(line)
-            if m:
-                results[(path, m.group('func'))] += int(m.group('size'), 16)
-        proc.wait()
-        if proc.returncode != 0:
-            if not args.get('verbose'):
-                for line in proc.stderr:
-                    sys.stdout.write(line)
-            sys.exit(-1)
-
-    flat_results = []
-    for (file, func), size in results.items():
-        # map to source files
-        if args.get('build_dir'):
-            file = re.sub('%s/*' % re.escape(args['build_dir']), '', file)
-        # discard internal functions
-        if func.startswith('__'):
-            continue
-        # discard .8449 suffixes created by optimizer
-        func = re.sub('\.[0-9]+', '', func)
-        flat_results.append((file, func, size))
-
-    return flat_results
-
-def main(**args):
-    # find sizes
-    if not args.get('use', None):
-        # find .o files
-        paths = []
-        for path in args['obj_paths']:
-            if os.path.isdir(path):
-                path = path + '/*.o'
-
-            for path in glob.glob(path):
-                paths.append(path)
-
-        if not paths:
-            print('no .obj files found in %r?' % args['obj_paths'])
-            sys.exit(-1)
-
-        results = collect(paths, **args)
-    else:
-        with open(args['use']) as f:
-            r = csv.DictReader(f)
-            results = [
-                (   result['file'],
-                    result['function'],
-                    int(result['size']))
-                for result in r]
-
-    total = 0
-    for _, _, size in results:
-        total += size
-
-    # find previous results?
-    if args.get('diff'):
-        with open(args['diff']) as f:
-            r = csv.DictReader(f)
-            prev_results = [
-                (   result['file'],
-                    result['function'],
-                    int(result['size']))
-                for result in r]
-
-        prev_total = 0
-        for _, _, size in prev_results:
-            prev_total += size
-
-    # write results to CSV
-    if args.get('output'):
-        with open(args['output'], 'w') as f:
-            w = csv.writer(f)
-            w.writerow(['file', 'function', 'size'])
-            for file, func, size in sorted(results):
-                w.writerow((file, func, size))
-
-    # print results
-    def dedup_entries(results, by='function'):
-        entries = co.defaultdict(lambda: 0)
-        for file, func, size in results:
-            entry = (file if by == 'file' else func)
-            entries[entry] += size
-        return entries
-
-    def diff_entries(olds, news):
-        diff = co.defaultdict(lambda: (0, 0, 0, 0))
-        for name, new in news.items():
-            diff[name] = (0, new, new, 1.0)
-        for name, old in olds.items():
-            _, new, _, _ = diff[name]
-            diff[name] = (old, new, new-old, (new-old)/old if old else 1.0)
-        return diff
-
-    def print_header(by=''):
-        if not args.get('diff'):
-            print('%-36s %7s' % (by, 'size'))
-        else:
-            print('%-36s %7s %7s %7s' % (by, 'old', 'new', 'diff'))
-
-    def print_entries(by='function'):
-        entries = dedup_entries(results, by=by)
-
-        if not args.get('diff'):
-            print_header(by=by)
-            for name, size in sorted(entries.items()):
-                print("%-36s %7d" % (name, size))
-        else:
-            prev_entries = dedup_entries(prev_results, by=by)
-            diff = diff_entries(prev_entries, entries)
-            print_header(by='%s (%d added, %d removed)' % (by,
-                sum(1 for old, _, _, _ in diff.values() if not old),
-                sum(1 for _, new, _, _ in diff.values() if not new)))
-            for name, (old, new, diff, ratio) in sorted(diff.items(),
-                    key=lambda x: (-x[1][3], x)):
-                if ratio or args.get('all'):
-                    print("%-36s %7s %7s %+7d%s" % (name,
-                        old or "-",
-                        new or "-",
-                        diff,
-                        ' (%+.1f%%)' % (100*ratio) if ratio else ''))
-
-    def print_totals():
-        if not args.get('diff'):
-            print("%-36s %7d" % ('TOTAL', total))
-        else:
-            ratio = (total-prev_total)/prev_total if prev_total else 1.0
-            print("%-36s %7s %7s %+7d%s" % (
-                'TOTAL',
-                prev_total if prev_total else '-',
-                total if total else '-',
-                total-prev_total,
-                ' (%+.1f%%)' % (100*ratio) if ratio else ''))
-
-    if args.get('quiet'):
-        pass
-    elif args.get('summary'):
-        print_header()
-        print_totals()
-    elif args.get('files'):
-        print_entries(by='file')
-        print_totals()
-    else:
-        print_entries(by='function')
-        print_totals()
-
-if __name__ == "__main__":
-    import argparse
-    import sys
-    parser = argparse.ArgumentParser(
-        description="Find code size at the function level.")
-    parser.add_argument('obj_paths', nargs='*', default=OBJ_PATHS,
-        help="Description of where to find *.o files. May be a directory \
-            or a list of paths. Defaults to %r." % OBJ_PATHS)
-    parser.add_argument('-v', '--verbose', action='store_true',
-        help="Output commands that run behind the scenes.")
-    parser.add_argument('-o', '--output',
-        help="Specify CSV file to store results.")
-    parser.add_argument('-u', '--use',
-        help="Don't compile and find code sizes, instead use this CSV file.")
-    parser.add_argument('-d', '--diff',
-        help="Specify CSV file to diff code size against.")
-    parser.add_argument('-a', '--all', action='store_true',
-        help="Show all functions, not just the ones that changed.")
-    parser.add_argument('--files', action='store_true',
-        help="Show file-level code sizes. Note this does not include padding! "
-            "So sizes may differ from other tools.")
-    parser.add_argument('-s', '--summary', action='store_true',
-        help="Only show the total code size.")
-    parser.add_argument('-q', '--quiet', action='store_true',
-        help="Don't show anything, useful with -o.")
-    parser.add_argument('--type', default='tTrRdDbB',
-        help="Type of symbols to report, this uses the same single-character "
-            "type-names emitted by nm. Defaults to %(default)r.")
-    parser.add_argument('--nm-tool', default=['nm'], type=lambda x: x.split(),
-        help="Path to the nm tool to use.")
-    parser.add_argument('--build-dir',
-        help="Specify the relative build directory. Used to map object files \
-            to the correct source files.")
-    sys.exit(main(**vars(parser.parse_args())))

scripts/coverage.py

@@ -1,254 +0,0 @@
-#!/usr/bin/env python3
-#
-# Parse and report coverage info from .info files generated by lcov
-#
-import os
-import glob
-import csv
-import re
-import collections as co
-import bisect as b
-
-
-INFO_PATHS = ['tests/*.toml.info']
-
-def collect(paths, **args):
-    file = None
-    funcs = []
-    lines = co.defaultdict(lambda: 0)
-    pattern = re.compile(
-        '^(?P<file>SF:/?(?P<file_name>.*))$'
-        '|^(?P<func>FN:(?P<func_lineno>[0-9]*),(?P<func_name>.*))$'
-        '|^(?P<line>DA:(?P<line_lineno>[0-9]*),(?P<line_hits>[0-9]*))$')
-    for path in paths:
-        with open(path) as f:
-            for line in f:
-                m = pattern.match(line)
-                if m and m.group('file'):
-                    file = m.group('file_name')
-                elif m and file and m.group('func'):
-                    funcs.append((file, int(m.group('func_lineno')),
-                        m.group('func_name')))
-                elif m and file and m.group('line'):
-                    lines[(file, int(m.group('line_lineno')))] += (
-                        int(m.group('line_hits')))
-
-    # map line numbers to functions
-    funcs.sort()
-    def func_from_lineno(file, lineno):
-        i = b.bisect(funcs, (file, lineno))
-        if i and funcs[i-1][0] == file:
-            return funcs[i-1][2]
-        else:
-            return None
-
-    # reduce to function info
-    reduced_funcs = co.defaultdict(lambda: (0, 0))
-    for (file, line_lineno), line_hits in lines.items():
-        func = func_from_lineno(file, line_lineno)
-        if not func:
-            continue
-        hits, count = reduced_funcs[(file, func)]
-        reduced_funcs[(file, func)] = (hits + (line_hits > 0), count + 1)
-
-    results = []
-    for (file, func), (hits, count) in reduced_funcs.items():
-        # discard internal/testing functions (test_* injected with
-        # internal testing)
-        if func.startswith('__') or func.startswith('test_'):
-            continue
-        # discard .8449 suffixes created by optimizer
-        func = re.sub('\.[0-9]+', '', func)
-        results.append((file, func, hits, count))
-
-    return results
-
-
-def main(**args):
-    # find coverage
-    if not args.get('use'):
-        # find *.info files
-        paths = []
-        for path in args['info_paths']:
-            if os.path.isdir(path):
-                path = path + '/*.gcov'
-
-            for path in glob.glob(path):
-                paths.append(path)
-
-        if not paths:
-            print('no .info files found in %r?' % args['info_paths'])
-            sys.exit(-1)
-
-        results = collect(paths, **args)
-    else:
-        with open(args['use']) as f:
-            r = csv.DictReader(f)
-            results = [
-                (   result['file'],
-                    result['function'],
-                    int(result['hits']),
-                    int(result['count']))
-                for result in r]
-
-    total_hits, total_count = 0, 0
-    for _, _, hits, count in results:
-        total_hits += hits
-        total_count += count
-
-    # find previous results?
-    if args.get('diff'):
-        with open(args['diff']) as f:
-            r = csv.DictReader(f)
-            prev_results = [
-                (   result['file'],
-                    result['function'],
-                    int(result['hits']),
-                    int(result['count']))
-                for result in r]
-
-        prev_total_hits, prev_total_count = 0, 0
-        for _, _, hits, count in prev_results:
-            prev_total_hits += hits
-            prev_total_count += count
-
-    # write results to CSV
-    if args.get('output'):
-        with open(args['output'], 'w') as f:
-            w = csv.writer(f)
-            w.writerow(['file', 'function', 'hits', 'count'])
-            for file, func, hits, count in sorted(results):
-                w.writerow((file, func, hits, count))
-
-    # print results
-    def dedup_entries(results, by='function'):
-        entries = co.defaultdict(lambda: (0, 0))
-        for file, func, hits, count in results:
-            entry = (file if by == 'file' else func)
-            entry_hits, entry_count = entries[entry]
-            entries[entry] = (entry_hits + hits, entry_count + count)
-        return entries
-
-    def diff_entries(olds, news):
-        diff = co.defaultdict(lambda: (0, 0, 0, 0, 0, 0, 0))
-        for name, (new_hits, new_count) in news.items():
-            diff[name] = (
-                0, 0,
-                new_hits, new_count,
-                new_hits, new_count,
-                (new_hits/new_count if new_count else 1.0) - 1.0)
-        for name, (old_hits, old_count) in olds.items():
-            _, _, new_hits, new_count, _, _, _ = diff[name]
-            diff[name] = (
-                old_hits, old_count,
-                new_hits, new_count,
-                new_hits-old_hits, new_count-old_count,
-                ((new_hits/new_count if new_count else 1.0)
-                    - (old_hits/old_count if old_count else 1.0)))
-        return diff
-
-    def print_header(by=''):
-        if not args.get('diff'):
-            print('%-36s %19s' % (by, 'hits/line'))
-        else:
-            print('%-36s %19s %19s %11s' % (by, 'old', 'new', 'diff'))
-
-    def print_entries(by='function'):
-        entries = dedup_entries(results, by=by)
-
-        if not args.get('diff'):
-            print_header(by=by)
-            for name, (hits, count) in sorted(entries.items()):
-                print("%-36s %11s %7s" % (name,
-                    '%d/%d' % (hits, count)
-                        if count else '-',
-                    '%.1f%%' % (100*hits/count)
-                        if count else '-'))
-        else:
-            prev_entries = dedup_entries(prev_results, by=by)
-            diff = diff_entries(prev_entries, entries)
-            print_header(by='%s (%d added, %d removed)' % (by,
-                sum(1 for _, old, _, _, _, _, _ in diff.values() if not old),
-                sum(1 for _, _, _, new, _, _, _ in diff.values() if not new)))
-            for name, (
-                    old_hits, old_count,
-                    new_hits, new_count,
-                    diff_hits, diff_count, ratio) in sorted(diff.items(),
-                        key=lambda x: (-x[1][6], x)):
-                if ratio or args.get('all'):
-                    print("%-36s %11s %7s %11s %7s %11s%s" % (name,
-                        '%d/%d' % (old_hits, old_count)
-                            if old_count else '-',
-                        '%.1f%%' % (100*old_hits/old_count)
-                            if old_count else '-',
-                        '%d/%d' % (new_hits, new_count)
-                            if new_count else '-',
-                        '%.1f%%' % (100*new_hits/new_count)
-                            if new_count else '-',
-                        '%+d/%+d' % (diff_hits, diff_count),
-                        ' (%+.1f%%)' % (100*ratio) if ratio else ''))
-
-    def print_totals():
-        if not args.get('diff'):
-            print("%-36s %11s %7s" % ('TOTAL',
-                '%d/%d' % (total_hits, total_count)
-                    if total_count else '-',
-                '%.1f%%' % (100*total_hits/total_count)
-                    if total_count else '-'))
-        else:
-            ratio = ((total_hits/total_count
-                    if total_count else 1.0)
-                - (prev_total_hits/prev_total_count
-                    if prev_total_count else 1.0))
-            print("%-36s %11s %7s %11s %7s %11s%s" % ('TOTAL',
-                '%d/%d' % (prev_total_hits, prev_total_count)
-                    if prev_total_count else '-',
-                '%.1f%%' % (100*prev_total_hits/prev_total_count)
-                    if prev_total_count else '-',
-                '%d/%d' % (total_hits, total_count)
-                    if total_count else '-',
-                '%.1f%%' % (100*total_hits/total_count)
-                    if total_count else '-',
-                '%+d/%+d' % (total_hits-prev_total_hits,
-                    total_count-prev_total_count),
-                ' (%+.1f%%)' % (100*ratio) if ratio else ''))
-
-    if args.get('quiet'):
-        pass
-    elif args.get('summary'):
-        print_header()
-        print_totals()
-    elif args.get('files'):
-        print_entries(by='file')
-        print_totals()
-    else:
-        print_entries(by='function')
-        print_totals()
-
-if __name__ == "__main__":
-    import argparse
-    import sys
-    parser = argparse.ArgumentParser(
-        description="Parse and report coverage info from .info files \
-            generated by lcov")
-    parser.add_argument('info_paths', nargs='*', default=INFO_PATHS,
-        help="Description of where to find *.info files. May be a directory \
-            or list of paths. *.info files will be merged to show the total \
-            coverage. Defaults to %r." % INFO_PATHS)
-    parser.add_argument('-v', '--verbose', action='store_true',
-        help="Output commands that run behind the scenes.")
-    parser.add_argument('-o', '--output',
-        help="Specify CSV file to store results.")
-    parser.add_argument('-u', '--use',
-        help="Don't do any work, instead use this CSV file.")
-    parser.add_argument('-d', '--diff',
-        help="Specify CSV file to diff code size against.")
-    parser.add_argument('-a', '--all', action='store_true',
-        help="Show all functions, not just the ones that changed.")
-    parser.add_argument('--files', action='store_true',
-        help="Show file-level coverage.")
-    parser.add_argument('-s', '--summary', action='store_true',
-        help="Only show the total coverage.")
-    parser.add_argument('-q', '--quiet', action='store_true',
-        help="Don't show anything, useful with -o.")
-    sys.exit(main(**vars(parser.parse_args())))

scripts/test.py

@@ -20,50 +20,19 @@ import pty
 import errno
 import signal
 
-TEST_PATHS = 'tests'
+TESTDIR = 'tests'
 RULES = """
-# add block devices to sources
-TESTSRC ?= $(SRC) $(wildcard bd/*.c)
-
 define FLATTEN
-%(path)s%%$(subst /,.,$(target)): $(target)
+tests/%$(subst /,.,$(target)): $(target)
     ./scripts/explode_asserts.py $$< -o $$@
 endef
-$(foreach target,$(TESTSRC),$(eval $(FLATTEN)))
+$(foreach target,$(SRC),$(eval $(FLATTEN)))
+
+-include tests/*.d
 
--include %(path)s*.d
 .SECONDARY:
-
-%(path)s.test: %(path)s.test.o \\
-        $(foreach t,$(subst /,.,$(TESTSRC:.c=.o)),%(path)s.$t)
+%.test: %.test.o $(foreach f,$(subst /,.,$(SRC:.c=.o)),%.$f)
     $(CC) $(CFLAGS) $^ $(LFLAGS) -o $@
-
-# needed in case builddir is different
-%(path)s%%.o: %(path)s%%.c
-    $(CC) -c -MMD $(CFLAGS) $< -o $@
-"""
-COVERAGE_RULES = """
-%(path)s.test: override CFLAGS += -fprofile-arcs -ftest-coverage
-
-# delete lingering coverage
-%(path)s.test: | %(path)s.info.clean
-.PHONY: %(path)s.info.clean
-%(path)s.info.clean:
-    rm -f %(path)s*.gcda
-
-# accumulate coverage info
-.PHONY: %(path)s.info
-%(path)s.info:
-    $(strip $(LCOV) -c \\
-        $(addprefix -d ,$(wildcard %(path)s*.gcda)) \\
-        --rc 'geninfo_adjust_src_path=$(shell pwd)' \\
-        -o $@)
-    $(LCOV) -e $@ $(addprefix /,$(SRC)) -o $@
-ifdef COVERAGETARGET
-    $(strip $(LCOV) -a $@ \\
-        $(addprefix -a ,$(wildcard $(COVERAGETARGET))) \\
-        -o $(COVERAGETARGET))
-endif
 """
 GLOBALS = """
 //////////////// AUTOGENERATED TEST ////////////////
@@ -150,8 +119,6 @@ class TestCase:
         self.if_ = config.get('if', None)
         self.in_ = config.get('in', None)
 
-        self.result = None
-
     def __str__(self):
         if hasattr(self, 'permno'):
             if any(k not in self.case.defines for k in self.defines):
@@ -212,7 +179,7 @@ class TestCase:
                 len(self.filter) >= 2 and
                 self.filter[1] != self.permno):
             return False
-        elif args.get('no_internal') and self.in_ is not None:
+        elif args.get('no_internal', False) and self.in_ is not None:
             return False
         elif self.if_ is not None:
             if_ = self.if_
@@ -246,7 +213,7 @@ class TestCase:
                 try:
                     with open(disk, 'w') as f:
                         f.truncate(0)
-                    if args.get('verbose'):
+                    if args.get('verbose', False):
                         print('truncate --size=0', disk)
                 except FileNotFoundError:
                     pass
@@ -270,14 +237,14 @@ class TestCase:
                     '-ex', 'r'])
             ncmd.extend(['--args'] + cmd)
 
-            if args.get('verbose'):
+            if args.get('verbose', False):
                 print(' '.join(shlex.quote(c) for c in ncmd))
             signal.signal(signal.SIGINT, signal.SIG_IGN)
             sys.exit(sp.call(ncmd))
 
         # run test case!
         mpty, spty = pty.openpty()
-        if args.get('verbose'):
+        if args.get('verbose', False):
             print(' '.join(shlex.quote(c) for c in cmd))
         proc = sp.Popen(cmd, stdout=spty, stderr=spty)
         os.close(spty)
@@ -292,10 +259,8 @@ class TestCase:
                     if e.errno == errno.EIO:
                         break
                     raise
-                if not line:
-                    break;
                 stdout.append(line)
-                if args.get('verbose'):
+                if args.get('verbose', False):
                     sys.stdout.write(line)
                 # intercept asserts
                 m = re.match(
@@ -334,7 +299,7 @@ class ValgrindTestCase(TestCase):
         return not self.leaky and super().shouldtest(**args)
 
     def test(self, exec=[], **args):
-        verbose = args.get('verbose')
+        verbose = args.get('verbose', False)
         uninit = (self.defines.get('LFS_ERASE_VALUE', None) == -1)
         exec = [
             'valgrind',
@@ -386,17 +351,12 @@ class TestSuite:
         self.name = os.path.basename(path)
         if self.name.endswith('.toml'):
             self.name = self.name[:-len('.toml')]
-        if args.get('build_dir'):
-            self.toml = path
-            self.path = args['build_dir'] + '/' + path
-        else:
-            self.toml = path
-            self.path = path
+        self.path = path
         self.classes = classes
         self.defines = defines.copy()
         self.filter = filter
 
-        with open(self.toml) as f:
+        with open(path) as f:
             # load tests
             config = toml.load(f)
 
@@ -507,7 +467,7 @@ class TestSuite:
 
     def build(self, **args):
         # build test files
-        tf = open(self.path + '.test.tc', 'w')
+        tf = open(self.path + '.test.c.t', 'w')
         tf.write(GLOBALS)
         if self.code is not None:
             tf.write('#line %d "%s"\n' % (self.code_lineno, self.path))
@@ -517,7 +477,7 @@ class TestSuite:
         for case in self.cases:
             if case.in_ not in tfs:
                 tfs[case.in_] = open(self.path+'.'+
-                    re.sub('(\.c)?$', '.tc', case.in_.replace('/', '.')), 'w')
+                    case.in_.replace('/', '.')+'.t', 'w')
                 tfs[case.in_].write('#line 1 "%s"\n' % case.in_)
                 with open(case.in_) as f:
                     for line in f:
@@ -556,33 +516,25 @@ class TestSuite:
 
         # write makefiles
         with open(self.path + '.mk', 'w') as mk:
-            mk.write(RULES.replace(4*' ', '\t') % dict(path=self.path))
+            mk.write(RULES.replace(4*' ', '\t'))
             mk.write('\n')
 
-            # add coverage hooks?
-            if args.get('coverage'):
-                mk.write(COVERAGE_RULES.replace(4*' ', '\t') % dict(
-                    path=self.path))
-                mk.write('\n')
-
-            # add truly global defines globally
+            # add truely global defines globally
             for k, v in sorted(self.defines.items()):
-                mk.write('%s.test: override CFLAGS += -D%s=%r\n'
-                    % (self.path, k, v))
+                mk.write('%s: override CFLAGS += -D%s=%r\n' % (
+                    self.path+'.test', k, v))
 
             for path in tfs:
                 if path is None:
                     mk.write('%s: %s | %s\n' % (
                         self.path+'.test.c',
-                        self.toml,
-                        self.path+'.test.tc'))
+                        self.path,
+                        self.path+'.test.c.t'))
                 else:
                     mk.write('%s: %s %s | %s\n' % (
                         self.path+'.'+path.replace('/', '.'),
-                        self.toml,
-                        path,
-                        self.path+'.'+re.sub('(\.c)?$', '.tc',
-                            path.replace('/', '.'))))
+                        self.path, path,
+                        self.path+'.'+path.replace('/', '.')+'.t'))
                 mk.write('\t./scripts/explode_asserts.py $| -o $@\n')
 
         self.makefile = self.path + '.mk'
@@ -605,7 +557,7 @@ class TestSuite:
                 if not args.get('verbose', True):
                     sys.stdout.write(FAIL)
                     sys.stdout.flush()
-                if not args.get('keep_going'):
+                if not args.get('keep_going', False):
                     if not args.get('verbose', True):
                         sys.stdout.write('\n')
                     raise
@@ -627,36 +579,36 @@ def main(**args):
 
     # and what class of TestCase to run
     classes = []
-    if args.get('normal'):
+    if args.get('normal', False):
         classes.append(TestCase)
-    if args.get('reentrant'):
+    if args.get('reentrant', False):
         classes.append(ReentrantTestCase)
-    if args.get('valgrind'):
+    if args.get('valgrind', False):
         classes.append(ValgrindTestCase)
     if not classes:
         classes = [TestCase]
 
     suites = []
-    for testpath in args['test_paths']:
+    for testpath in args['testpaths']:
         # optionally specified test case/perm
         testpath, *filter = testpath.split('#')
         filter = [int(f) for f in filter]
 
         # figure out the suite's toml file
         if os.path.isdir(testpath):
-            testpath = testpath + '/*.toml'
+            testpath = testpath + '/test_*.toml'
         elif os.path.isfile(testpath):
             testpath = testpath
         elif testpath.endswith('.toml'):
-            testpath = TEST_PATHS + '/' + testpath
+            testpath = TESTDIR + '/' + testpath
         else:
-            testpath = TEST_PATHS + '/' + testpath + '.toml'
+            testpath = TESTDIR + '/' + testpath + '.toml'
 
         # find tests
         for path in glob.glob(testpath):
             suites.append(TestSuite(path, classes, defines, filter, **args))
 
-    # sort for reproducibility
+    # sort for reproducability
     suites = sorted(suites)
 
     # generate permutations
@@ -676,7 +628,7 @@ def main(**args):
         list(it.chain.from_iterable(['-f', m] for m in makefiles)) +
         [target for target in targets])
     mpty, spty = pty.openpty()
-    if args.get('verbose'):
+    if args.get('verbose', False):
         print(' '.join(shlex.quote(c) for c in cmd))
     proc = sp.Popen(cmd, stdout=spty, stderr=spty)
     os.close(spty)
@@ -689,17 +641,15 @@ def main(**args):
             if e.errno == errno.EIO:
                 break
             raise
-        if not line:
-            break;
         stdout.append(line)
-        if args.get('verbose'):
+        if args.get('verbose', False):
             sys.stdout.write(line)
         # intercept warnings
         m = re.match(
             '^{0}([^:]+):(\d+):(?:\d+:)?{0}{1}:{0}(.*)$'
             .format('(?:\033\[[\d;]*.| )*', 'warning'),
             line)
-        if m and not args.get('verbose'):
+        if m and not args.get('verbose', False):
             try:
                 with open(m.group(1)) as f:
                     lineno = int(m.group(2))
@@ -712,26 +662,27 @@ def main(**args):
             except:
                 pass
     proc.wait()
+
     if proc.returncode != 0:
-        if not args.get('verbose'):
+        if not args.get('verbose', False):
             for line in stdout:
                 sys.stdout.write(line)
-        sys.exit(-1)
+        sys.exit(-3)
 
     print('built %d test suites, %d test cases, %d permutations' % (
         len(suites),
         sum(len(suite.cases) for suite in suites),
         sum(len(suite.perms) for suite in suites)))
 
-    total = 0
+    filtered = 0
     for suite in suites:
         for perm in suite.perms:
-            total += perm.shouldtest(**args)
-    if total != sum(len(suite.perms) for suite in suites):
-        print('filtered down to %d permutations' % total)
+            filtered += perm.shouldtest(**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'):
+    if args.get('build', False):
         return 0
 
     print('====== testing ======')
@@ -746,12 +697,15 @@ def main(**args):
     failed = 0
     for suite in suites:
         for perm in suite.perms:
+            if not hasattr(perm, 'result'):
+                continue
+
             if perm.result == PASS:
                 passed += 1
-            elif isinstance(perm.result, TestFailure):
+            else:
                 sys.stdout.write(
                     "\033[01m{path}:{lineno}:\033[01;31mfailure:\033[m "
-                    "{perm} failed\n".format(
+                    "{perm} failed with {returncode}\n".format(
                         perm=perm, path=perm.suite.path, lineno=perm.lineno,
                         returncode=perm.result.returncode or 0))
                 if perm.result.stdout:
@@ -769,33 +723,11 @@ def main(**args):
                 sys.stdout.write('\n')
                 failed += 1
 
-    if args.get('coverage'):
-        # collect coverage info
-        # why -j1? lcov doesn't work in parallel because of gcov limitations
-        cmd = (['make', '-j1', '-f', 'Makefile'] +
-            list(it.chain.from_iterable(['-f', m] for m in makefiles)) +
-            (['COVERAGETARGET=%s' % args['coverage']]
-                if isinstance(args['coverage'], str) else []) +
-            [suite.path + '.info' for suite in suites
-                if any(perm.result == PASS for perm in suite.perms)])
-        if args.get('verbose'):
-            print(' '.join(shlex.quote(c) for c in cmd))
-        proc = sp.Popen(cmd,
-            stdout=sp.PIPE if not args.get('verbose') else None,
-            stderr=sp.STDOUT if not args.get('verbose') else None,
-            universal_newlines=True)
-        proc.wait()
-        if proc.returncode != 0:
-            if not args.get('verbose'):
-                for line in proc.stdout:
-                    sys.stdout.write(line)
-            sys.exit(-1)
-
-    if args.get('gdb'):
+    if args.get('gdb', False):
         failure = None
         for suite in suites:
             for perm in suite.perms:
-                if isinstance(perm.result, TestFailure):
+                if getattr(perm, 'result', PASS) != PASS:
                     failure = perm.result
         if failure is not None:
             print('======= gdb ======')
@@ -803,22 +735,20 @@ def main(**args):
             failure.case.test(failure=failure, **args)
             sys.exit(0)
 
-    print('tests passed %d/%d (%.2f%%)' % (passed, total,
-        100*(passed/total if total else 1.0)))
-    print('tests failed %d/%d (%.2f%%)' % (failed, total,
-        100*(failed/total if total else 1.0)))
+    print('tests passed: %d' % passed)
+    print('tests failed: %d' % failed)
     return 1 if failed > 0 else 0
 
 if __name__ == "__main__":
     import argparse
     parser = argparse.ArgumentParser(
         description="Run parameterized tests in various configurations.")
-    parser.add_argument('test_paths', nargs='*', default=[TEST_PATHS],
+    parser.add_argument('testpaths', nargs='*', default=[TESTDIR],
         help="Description of test(s) to run. By default, this is all tests \
             found in the \"{0}\" directory. Here, you can specify a different \
-            directory of tests, a specific file, a suite by name, and even \
-            specific test cases and permutations. For example \
-            \"test_dirs#1\" or \"{0}/test_dirs.toml#1#1\".".format(TEST_PATHS))
+            directory of tests, a specific file, a suite by name, and even a \
+            specific test case by adding brackets. For example \
+            \"test_dirs[0]\" or \"{0}/test_dirs.toml[0]\".".format(TESTDIR))
     parser.add_argument('-D', action='append', default=[],
         help="Overriding parameter definitions.")
     parser.add_argument('-v', '--verbose', action='store_true',
@@ -839,19 +769,10 @@ if __name__ == "__main__":
         help="Run tests normally.")
     parser.add_argument('-r', '--reentrant', action='store_true',
         help="Run reentrant tests with simulated power-loss.")
-    parser.add_argument('--valgrind', action='store_true',
+    parser.add_argument('-V', '--valgrind', action='store_true',
         help="Run non-leaky tests under valgrind to check for memory leaks.")
-    parser.add_argument('--exec', default=[], type=lambda e: e.split(),
+    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('--disk',
+    parser.add_argument('-d', '--disk',
         help="Specify a file to use for persistent/reentrant tests.")
-    parser.add_argument('--coverage', type=lambda x: x if x else True,
-        nargs='?', const='',
-        help="Collect coverage information during testing. This uses lcov/gcov \
-            to accumulate coverage information into *.info files. May also \
-            a path to a *.info file to accumulate coverage info into.")
-    parser.add_argument('--build-dir',
-        help="Build relative to the specified directory instead of the \
-            current directory.")
-
     sys.exit(main(**vars(parser.parse_args())))

tests/test_attrs.toml

@@ -16,41 +16,39 @@ code = '''
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 6;
     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "bbbbbb", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     lfs_setattr(&lfs, "hello", 'B', "", 0) => 0;
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 0;
     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",         4) => 0;
-    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",        5) => 0;
+    assert(memcmp(buffer,    "aaaa",         4) == 0);
+    assert(memcmp(buffer+10, "ccccc",        5) == 0);
 
     lfs_removeattr(&lfs, "hello", 'B') => 0;
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => LFS_ERR_NOATTR;
     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",         4) => 0;
-    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",        5) => 0;
+    assert(memcmp(buffer,    "aaaa",         4) == 0);
+    assert(memcmp(buffer+10, "ccccc",        5) == 0);
 
     lfs_setattr(&lfs, "hello", 'B', "dddddd", 6) => 0;
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 6;
     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "dddddd", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "dddddd", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     lfs_setattr(&lfs, "hello", 'B', "eee", 3) => 0;
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  6) => 3;
     lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+4,  "eee",   3) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     lfs_setattr(&lfs, "hello", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
     lfs_setattr(&lfs, "hello", 'B', "fffffffff", 9) => 0;
@@ -65,13 +63,13 @@ code = '''
     lfs_getattr(&lfs, "hello", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "hello", 'B', buffer+4,  9) => 9;
     lfs_getattr(&lfs, "hello", 'C', buffer+13, 5) => 5;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "fffffffff", 9) => 0;
-    memcmp(buffer+13, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",      4) == 0);
+    assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
+    assert(memcmp(buffer+13, "ccccc",     5) == 0);
 
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
-    memcmp(buffer, "hello", strlen("hello")) => 0;
+    assert(memcmp(buffer, "hello", strlen("hello")) == 0);
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 '''
@@ -94,41 +92,39 @@ code = '''
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 6;
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "bbbbbb", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     lfs_setattr(&lfs, "/", 'B', "", 0) => 0;
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 0;
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",         4) => 0;
-    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",        5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     lfs_removeattr(&lfs, "/", 'B') => 0;
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => LFS_ERR_NOATTR;
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",         4) => 0;
-    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",        5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     lfs_setattr(&lfs, "/", 'B', "dddddd", 6) => 0;
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 6;
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "dddddd", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "dddddd", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     lfs_setattr(&lfs, "/", 'B', "eee", 3) => 0;
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  6) => 3;
     lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+4,  "eee",   3) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     lfs_setattr(&lfs, "/", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
     lfs_setattr(&lfs, "/", 'B', "fffffffff", 9) => 0;
@@ -142,13 +138,13 @@ code = '''
     lfs_getattr(&lfs, "/", 'A', buffer,    4) => 4;
     lfs_getattr(&lfs, "/", 'B', buffer+4,  9) => 9;
     lfs_getattr(&lfs, "/", 'C', buffer+13, 5) => 5;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "fffffffff", 9) => 0;
-    memcmp(buffer+13, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",      4) == 0);
+    assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
+    assert(memcmp(buffer+13, "ccccc",     5) == 0);
 
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
-    memcmp(buffer, "hello", strlen("hello")) => 0;
+    assert(memcmp(buffer, "hello", strlen("hello")) == 0);
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 '''
@@ -176,52 +172,55 @@ code = '''
     memcpy(buffer,    "aaaa",   4);
     memcpy(buffer+4,  "bbbbbb", 6);
     memcpy(buffer+10, "ccccc",  5);
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_close(&lfs, &file) => 0;
     memset(buffer, 0, 15);
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
     lfs_file_close(&lfs, &file) => 0;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "bbbbbb", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "bbbbbb", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     attrs1[1].size = 0;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_close(&lfs, &file) => 0;
     memset(buffer, 0, 15);
     attrs1[1].size = 6;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
     lfs_file_close(&lfs, &file) => 0;
-    memcmp(buffer,    "aaaa",         4) => 0;
-    memcmp(buffer+4,  "\0\0\0\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",        5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     attrs1[1].size = 6;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
     memcpy(buffer+4,  "dddddd", 6);
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_close(&lfs, &file) => 0;
     memset(buffer, 0, 15);
     attrs1[1].size = 6;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
     lfs_file_close(&lfs, &file) => 0;
-    memcmp(buffer,    "aaaa",   4) => 0;
-    memcmp(buffer+4,  "dddddd", 6) => 0;
-    memcmp(buffer+10, "ccccc",  5) => 0;
+    assert(memcmp(buffer,    "aaaa",   4) == 0);
+    assert(memcmp(buffer+4,  "dddddd", 6) == 0);
+    assert(memcmp(buffer+10, "ccccc",  5) == 0);
 
     attrs1[1].size = 3;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
     memcpy(buffer+4,  "eee", 3);
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_close(&lfs, &file) => 0;
     memset(buffer, 0, 15);
     attrs1[1].size = 6;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
     lfs_file_close(&lfs, &file) => 0;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "eee\0\0\0", 6) => 0;
-    memcmp(buffer+10, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",  4) == 0);
+    assert(memcmp(buffer+4,  "eee",   3) == 0);
+    assert(memcmp(buffer+10, "ccccc", 5) == 0);
 
     attrs1[0].size = LFS_ATTR_MAX+1;
-    lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1)
-        => LFS_ERR_NOSPC;
+    lfs_file_opencfg(&lfs, &file, "hello/hello2",
+            LFS_O_WRONLY | LFS_O_CREAT, &cfg1) => LFS_ERR_NOSPC;
 
     struct lfs_attr attrs2[] = {
         {'A', buffer,    4},
@@ -231,6 +230,7 @@ code = '''
     struct lfs_file_config cfg2 = {.attrs=attrs2, .attr_count=3};
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDWR, &cfg2) => 0;
     memcpy(buffer+4,  "fffffffff", 9);
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_close(&lfs, &file) => 0;
     attrs1[0].size = 4;
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
@@ -249,13 +249,13 @@ code = '''
 
     lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg3) => 0;
     lfs_file_close(&lfs, &file) => 0;
-    memcmp(buffer,    "aaaa",      4) => 0;
-    memcmp(buffer+4,  "fffffffff", 9) => 0;
-    memcmp(buffer+13, "ccccc",     5) => 0;
+    assert(memcmp(buffer,    "aaaa",      4) == 0);
+    assert(memcmp(buffer+4,  "fffffffff", 9) == 0);
+    assert(memcmp(buffer+13, "ccccc",     5) == 0);
 
     lfs_file_open(&lfs, &file, "hello/hello", LFS_O_RDONLY) => 0;
     lfs_file_read(&lfs, &file, buffer, sizeof(buffer)) => strlen("hello");
-    memcmp(buffer, "hello", strlen("hello")) => 0;
+    assert(memcmp(buffer, "hillo", strlen("hello")) == 0);
     lfs_file_close(&lfs, &file);
     lfs_unmount(&lfs) => 0;
 '''
@@ -287,17 +287,16 @@ code = '''
     lfs_getattr(&lfs, "hello/hello", 'B', buffer,    9) => 9;
     lfs_getattr(&lfs, "hello/hello", 'C', buffer+9,  9) => 5;
     lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => LFS_ERR_NOATTR;
-    memcmp(buffer,    "fffffffff",          9) => 0;
-    memcmp(buffer+9,  "ccccc\0\0\0\0",      9) => 0;
-    memcmp(buffer+18, "\0\0\0\0\0\0\0\0\0", 9) => 0;
+    assert(memcmp(buffer,    "fffffffff", 9) == 0);
+    assert(memcmp(buffer+9,  "ccccc",     5) == 0);
 
+    lfs_file_write(&lfs, &file, "hi", 2) => 2;
     lfs_file_sync(&lfs, &file) => 0;
     lfs_getattr(&lfs, "hello/hello", 'B', buffer,    9) => 4;
     lfs_getattr(&lfs, "hello/hello", 'C', buffer+9,  9) => 0;
     lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => 4;
-    memcmp(buffer,    "gggg\0\0\0\0\0",     9) => 0;
-    memcmp(buffer+9,  "\0\0\0\0\0\0\0\0\0", 9) => 0;
-    memcmp(buffer+18, "hhhh\0\0\0\0\0",     9) => 0;
+    assert(memcmp(buffer,    "gggg", 4) == 0);
+    assert(memcmp(buffer+18, "hhhh", 4) == 0);
 
     lfs_file_close(&lfs, &file) => 0;
     lfs_unmount(&lfs) => 0;

tests/test_interspersed.toml

@@ -1,7 +1,7 @@
 
 [[case]] # interspersed file test
 define.SIZE = [10, 100]
-define.FILES = [4, 10, 26] 
+define.FILES = [4, 10, 26]
 code = '''
     lfs_file_t files[FILES];
     const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
@@ -55,7 +55,7 @@ code = '''
     for (int j = 0; j < FILES; j++) {
         lfs_file_close(&lfs, &files[j]);
     }
-    
+
     lfs_unmount(&lfs) => 0;
 '''
 
@@ -108,7 +108,7 @@ code = '''
         assert(buffer[0] == '~');
     }
     lfs_file_close(&lfs, &file);
-    
+
     lfs_unmount(&lfs) => 0;
 '''
 
@@ -168,13 +168,13 @@ code = '''
     }
     lfs_file_close(&lfs, &files[0]);
     lfs_file_close(&lfs, &files[1]);
-    
+
     lfs_unmount(&lfs) => 0;
 '''
 
 [[case]] # reentrant interspersed file test
 define.SIZE = [10, 100]
-define.FILES = [4, 10, 26] 
+define.FILES = [4, 10, 26]
 reentrant = true
 code = '''
     lfs_file_t files[FILES];
@@ -239,6 +239,698 @@ code = '''
     for (int j = 0; j < FILES; j++) {
         lfs_file_close(&lfs, &files[j]);
     }
-    
+
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # open same file reading from separate file handles
+define.READERS = 3
+define.SIZE = [10, 100, 1000, 10000]
+define.RDMODE = ['LFS_O_RDONLY', 'LFS_O_RDWR']
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "shared", LFS_O_CREAT | LFS_O_WRONLY) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open all files
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t readers[READERS];
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_open(&lfs, &readers[i], "shared", RDMODE) => 0;
+    }
+
+    // perform operations while all readers are open
+    for (int i = 0; i < READERS; i++) {
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == alphas[j % 26]);
+        }
+    }
+
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_close(&lfs, &readers[i]) => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # open same file reading and writing from separate file handles
+define.READERS = 3
+define.SIZE = [10, 100, 1000, 10000]
+define.RDMODE = ['LFS_O_RDONLY', 'LFS_O_RDWR']
+define.WRMODE = ['LFS_O_WRONLY', 'LFS_O_RDWR']
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    const char nums[] = "0123456789";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, "shared", LFS_O_CREAT | LFS_O_WRONLY) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open all files
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t writer;
+    lfs_file_t readers[READERS];
+    lfs_file_open(&lfs, &writer, "shared", WRMODE) => 0;
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_open(&lfs, &readers[i], "shared", RDMODE) => 0;
+    }
+
+    // perform operations while all readers are open
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &writer, &nums[j % 10], 1) => 1;
+    }
+
+    for (int i = 0; i < READERS; i++) {
+        for (int j = 0; j < SIZE/2; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == alphas[j % 26]);
+        }
+    }
+
+    // sync, now write should reflect in all open files
+    lfs_file_sync(&lfs, &writer) => 0;
+
+    for (int i = 0; i < READERS; i++) {
+        for (int j = SIZE/2; j < SIZE; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    }
+
+    // double check our writer reflects its own changes
+    if (WRMODE == LFS_O_RDWR) {
+        lfs_file_rewind(&lfs, &writer) => 0;
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &writer, buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    }
+
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_close(&lfs, &readers[i]) => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # check that attributes are updated in open files
+define.READERS = 3
+define.SIZE = 10
+define.RDMODE = ['LFS_O_RDONLY', 'LFS_O_RDWR']
+define.WRMODE = ['LFS_O_WRONLY', 'LFS_O_RDWR']
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    const char nums[] = "0123456789";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    const struct lfs_file_config filecfg = {
+        .attr_count = 3,
+        .attrs = (struct lfs_attr[]){
+            {'A', "a",   1},
+            {'B', "bb",  2},
+            {'C', "ccc", 3},
+        },
+    };
+    lfs_file_opencfg(&lfs, &file, "shared",
+            LFS_O_CREAT | LFS_O_WRONLY, &filecfg) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open all files
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t writer;
+    const struct lfs_file_config writercfg = {
+        .attr_count = 3,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[1]){0}, 1},
+            {'B', &(uint8_t[2]){0}, 2},
+            {'C', &(uint8_t[3]){0}, 3}}};
+    lfs_file_t readers[READERS];
+    const struct lfs_file_config readercfgs[READERS] = {
+        {   .attr_count = 3,
+            .attrs = (struct lfs_attr[]){
+                {'A', &(uint8_t[1]){0}, 1},
+                {'B', &(uint8_t[2]){0}, 2},
+                {'C', &(uint8_t[3]){0}, 3}}},
+        {   .attr_count = 3,
+            .attrs = (struct lfs_attr[]){
+                {'A', &(uint8_t[1]){0}, 1},
+                {'B', &(uint8_t[2]){0}, 2},
+                {'C', &(uint8_t[3]){0}, 3}}},
+        {   .attr_count = 3,
+            .attrs = (struct lfs_attr[]){
+                {'A', &(uint8_t[1]){0}, 1},
+                {'B', &(uint8_t[2]){0}, 2},
+                {'C', &(uint8_t[3]){0}, 3}}}};
+    lfs_file_opencfg(&lfs, &writer, "shared",
+            WRMODE, &writercfg) => 0;
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_opencfg(&lfs, &readers[i], "shared",
+                RDMODE, &readercfgs[i]) => 0;
+    }
+
+    // perform operations while all readers are open
+    writercfg.attrs[0].size = 1;
+    memcpy(writercfg.attrs[0].buffer, "0", 1);
+    writercfg.attrs[1].size = 2;
+    memcpy(writercfg.attrs[1].buffer, "11", 2);
+    writercfg.attrs[2].size = 3;
+    memcpy(writercfg.attrs[2].buffer, "222", 3);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &writer, &nums[j % 10], 1) => 1;
+    }
+
+    for (int i = 0; i < READERS; i++) {
+        assert(readercfgs[i].attrs[0].size == 1);
+        assert(memcmp(readercfgs[i].attrs[0].buffer, "a", 1) == 0);
+        assert(readercfgs[i].attrs[1].size == 2);
+        assert(memcmp(readercfgs[i].attrs[1].buffer, "bb", 2) == 0);
+        assert(readercfgs[i].attrs[2].size == 3);
+        assert(memcmp(readercfgs[i].attrs[2].buffer, "ccc", 3) == 0);
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == alphas[j % 26]);
+        }
+    }
+
+    // sync, now write should reflect in all open files
+    lfs_file_sync(&lfs, &writer) => 0;
+
+    for (int i = 0; i < READERS; i++) {
+        assert(readercfgs[i].attrs[0].size == 1);
+        assert(memcmp(readercfgs[i].attrs[0].buffer, "0", 1) == 0);
+        assert(readercfgs[i].attrs[1].size == 2);
+        assert(memcmp(readercfgs[i].attrs[1].buffer, "11", 2) == 0);
+        assert(readercfgs[i].attrs[2].size == 3);
+        assert(memcmp(readercfgs[i].attrs[2].buffer, "222", 3) == 0);
+        lfs_file_rewind(&lfs, &readers[i]) => 0;
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    }
+
+    // double check our writer reflects its own changes
+    if (WRMODE == LFS_O_RDWR) {
+        assert(writercfg.attrs[0].size == 1);
+        assert(memcmp(writercfg.attrs[0].buffer, "0", 1) == 0);
+        assert(writercfg.attrs[1].size == 2);
+        assert(memcmp(writercfg.attrs[1].buffer, "11", 2) == 0);
+        assert(writercfg.attrs[2].size == 3);
+        assert(memcmp(writercfg.attrs[2].buffer, "222", 3) == 0);
+        lfs_file_rewind(&lfs, &writer) => 0;
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &writer, buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    }
+
+    // now try explicit lfs_setattr calls, this should still update open files
+    lfs_setattr(&lfs, "shared", 'A', "A",   1) => 0;
+    lfs_setattr(&lfs, "shared", 'B', "BB",  2) => 0;
+    lfs_setattr(&lfs, "shared", 'C', "CCC", 3) => 0;
+
+    for (int i = 0; i < READERS; i++) {
+        assert(readercfgs[i].attrs[0].size == 1);
+        assert(memcmp(readercfgs[i].attrs[0].buffer, "A", 1) == 0);
+        assert(readercfgs[i].attrs[1].size == 2);
+        assert(memcmp(readercfgs[i].attrs[1].buffer, "BB", 2) == 0);
+        assert(readercfgs[i].attrs[2].size == 3);
+        assert(memcmp(readercfgs[i].attrs[2].buffer, "CCC", 3) == 0);
+        lfs_file_rewind(&lfs, &readers[i]) => 0;
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &readers[i], buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    }
+
+    if (WRMODE == LFS_O_RDWR) {
+        assert(writercfg.attrs[0].size == 1);
+        assert(memcmp(writercfg.attrs[0].buffer, "A", 1) == 0);
+        assert(writercfg.attrs[1].size == 2);
+        assert(memcmp(writercfg.attrs[1].buffer, "BB", 2) == 0);
+        assert(writercfg.attrs[2].size == 3);
+        assert(memcmp(writercfg.attrs[2].buffer, "CCC", 3) == 0);
+        lfs_file_rewind(&lfs, &writer) => 0;
+        for (int j = 0; j < SIZE; j++) {
+            lfs_file_read(&lfs, &writer, buffer, 1) => 1;
+            assert(buffer[0] == nums[j % 10]);
+        }
+    } else if (WRMODE == LFS_O_WRONLY) {
+        // this should NOT update wronly attributes, these may be
+        // stored in read-only memory
+        assert(writercfg.attrs[0].size == 1);
+        assert(memcmp(writercfg.attrs[0].buffer, "0", 1) == 0);
+        assert(writercfg.attrs[1].size == 2);
+        assert(memcmp(writercfg.attrs[1].buffer, "11", 2) == 0);
+        assert(writercfg.attrs[2].size == 3);
+        assert(memcmp(writercfg.attrs[2].buffer, "222", 3) == 0);
+    }
+
+    for (int i = 0; i < READERS; i++) {
+        lfs_file_close(&lfs, &readers[i]) => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # simple snapshot for reading
+define.SIZE = [10, 100, 1000, 10000]
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    const char nums[] = "0123456789";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    const struct lfs_file_config filecfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', "abcd", 4},
+        },
+    };
+    lfs_file_opencfg(&lfs, &file, "open_me",
+            LFS_O_CREAT | LFS_O_WRONLY, &filecfg) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open reader/writer/snapshot
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t reader;
+    const struct lfs_file_config readercfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_t writer;
+    const struct lfs_file_config writercfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_t snapshot;
+    const struct lfs_file_config snapshotcfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    lfs_file_opencfg(&lfs, &writer, "open_me",
+            LFS_O_WRONLY, &writercfg) => 0;
+    lfs_file_opencfg(&lfs, &snapshot, "open_me",
+            LFS_O_RDONLY | LFS_O_SNAPSHOT, &snapshotcfg) => 0;
+
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE/2; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    assert(memcmp(snapshotcfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE/2; j++) {
+        lfs_file_read(&lfs, &snapshot, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    // write file
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &writer, &nums[j % 10], 1) => 1;
+    }
+    memcpy(writercfg.attrs[0].buffer, "0123", 4);
+    lfs_file_sync(&lfs, &writer) => 0;
+
+    // reader should change
+    assert(memcmp(readercfg.attrs[0].buffer, "0123", 4) == 0);
+    for (int j = SIZE/2; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    // snapshot should remain unchanged
+    assert(memcmp(snapshotcfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = SIZE/2; j < SIZE; j++) {
+        lfs_file_read(&lfs, &snapshot, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_file_close(&lfs, &writer) => 0;
+    lfs_file_close(&lfs, &snapshot) => 0;
+
+    // disk should change
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "0123", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "0123", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # simple snapshot for writing
+define.SIZE = [10, 100, 1000, 10000]
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    const char nums[] = "0123456789";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    const struct lfs_file_config filecfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', "abcd", 4},
+        },
+    };
+    lfs_file_opencfg(&lfs, &file, "open_me",
+            LFS_O_CREAT | LFS_O_WRONLY, &filecfg) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open reader/snapshot
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t reader;
+    const struct lfs_file_config readercfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_t snapshot;
+    const struct lfs_file_config snapshotcfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    lfs_file_opencfg(&lfs, &snapshot, "open_me",
+            LFS_O_RDWR | LFS_O_SNAPSHOT, &snapshotcfg) => 0;
+
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE/2; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    assert(memcmp(snapshotcfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &snapshot, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    // modify snapshot
+    lfs_file_rewind(&lfs, &snapshot) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &snapshot, &nums[j % 10], 1) => 1;
+    }
+    memcpy(snapshotcfg.attrs[0].buffer, "0123", 4);
+
+    lfs_file_rewind(&lfs, &snapshot) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &snapshot, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    lfs_file_sync(&lfs, &snapshot) => 0;
+
+    // reader should not change
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = SIZE/2; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    // snapshot should changed
+    assert(memcmp(snapshotcfg.attrs[0].buffer, "0123", 4) == 0);
+    lfs_file_rewind(&lfs, &snapshot) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &snapshot, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_file_close(&lfs, &snapshot) => 0;
+
+    // disk should not change
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # temporary files
+define.SIZE = [10, 100, 1000, 10000]
+define.TMP_PATH = 'range(4)'
+code = '''
+    const char alphas[] = "abcdefghijklmnopqrstuvwxyz";
+    const char nums[] = "0123456789";
+    const char caps[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    const struct lfs_file_config filecfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', "abcd", 4},
+        },
+    };
+    lfs_file_opencfg(&lfs, &file, "open_me",
+            LFS_O_CREAT | LFS_O_WRONLY, &filecfg) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_file_opencfg(&lfs, &file, "dont_open_me",
+            LFS_O_CREAT | LFS_O_WRONLY, &filecfg) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &file, &alphas[j % 26], 1) => 1;
+    }
+    lfs_file_close(&lfs, &file) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    // open reader/writer/temp
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_t reader;
+    const struct lfs_file_config readercfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_t writer;
+    const struct lfs_file_config writercfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_t tmp;
+    const struct lfs_file_config tmpcfg = {
+        .attr_count = 1,
+        .attrs = (struct lfs_attr[]){
+            {'A', &(uint8_t[4]){0}, 4}
+        },
+    };
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    lfs_file_opencfg(&lfs, &writer, "open_me",
+            LFS_O_WRONLY, &writercfg) => 0;
+    const char *tmp_paths[] = {NULL, "/", "/tmp", "/open_me.tmp"};
+    lfs_file_opencfg(&lfs, &tmp, tmp_paths[TMP_PATH],
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_SNAPSHOT, &tmpcfg) => 0;
+
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE/3; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    assert(memcmp(tmpcfg.attrs[0].buffer, "\0\0\0\0", 4) == 0);
+    assert(lfs_file_size(&lfs, &tmp) == 0);
+
+    // write to tmp
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &tmp, &nums[j % 10], 1) => 1;
+    }
+    memcpy(tmpcfg.attrs[0].buffer, "0123", 4);
+
+    lfs_file_rewind(&lfs, &tmp) => 0;
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &tmp, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    lfs_file_sync(&lfs, &tmp) => 0;
+
+    // reader should not change
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = SIZE/3; j < 2*SIZE/3; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+
+    // tmp should change
+    assert(memcmp(tmpcfg.attrs[0].buffer, "0123", 4) == 0);
+    lfs_file_rewind(&lfs, &tmp) => 0;
+    for (int j = 0; j < SIZE/2; j++) {
+        lfs_file_read(&lfs, &tmp, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    // write to file
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_write(&lfs, &writer, &caps[j % 26], 1) => 1;
+    }
+    memcpy(writercfg.attrs[0].buffer, "ABCD", 4);
+    lfs_file_sync(&lfs, &writer) => 0;
+
+    // reader should change
+    assert(memcmp(readercfg.attrs[0].buffer, "ABCD", 4) == 0);
+    for (int j = 2*SIZE/3; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == caps[j % 26]);
+    }
+
+    // tmp should not change
+    assert(memcmp(tmpcfg.attrs[0].buffer, "0123", 4) == 0);
+    for (int j = SIZE/2; j < SIZE; j++) {
+        lfs_file_read(&lfs, &tmp, buffer, 1) => 1;
+        assert(buffer[0] == nums[j % 10]);
+    }
+
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_file_close(&lfs, &writer) => 0;
+    lfs_file_close(&lfs, &tmp) => 0;
+
+    // tmp should not appear on disk
+    lfs_dir_open(&lfs, &dir, "/") => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, ".") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, "..") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "dont_open_me") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "open_me") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "ABCD", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == caps[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_file_opencfg(&lfs, &reader, "dont_open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_dir_open(&lfs, &dir, "/") => 0;
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, ".") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_DIR);
+    assert(strcmp(info.name, "..") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "dont_open_me") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 1;
+    assert(info.type == LFS_TYPE_REG);
+    assert(strcmp(info.name, "open_me") == 0);
+    lfs_dir_read(&lfs, &dir, &info) => 0;
+    lfs_dir_close(&lfs, &dir) => 0;
+    lfs_file_opencfg(&lfs, &reader, "open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "ABCD", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == caps[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_file_opencfg(&lfs, &reader, "dont_open_me",
+            LFS_O_RDONLY, &readercfg) => 0;
+    assert(memcmp(readercfg.attrs[0].buffer, "abcd", 4) == 0);
+    for (int j = 0; j < SIZE; j++) {
+        lfs_file_read(&lfs, &reader, buffer, 1) => 1;
+        assert(buffer[0] == alphas[j % 26]);
+    }
+    lfs_file_close(&lfs, &reader) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # test snapshot open errors
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_file_open(&lfs, &file, NULL,
+            LFS_O_RDWR | LFS_O_SNAPSHOT) => LFS_ERR_ISDIR;
+    lfs_file_open(&lfs, &file, "/",
+            LFS_O_RDWR | LFS_O_SNAPSHOT) => LFS_ERR_ISDIR;
+    lfs_file_open(&lfs, &file, "/tmp",
+            LFS_O_RDWR | LFS_O_SNAPSHOT) => LFS_ERR_NOENT;
+    lfs_file_open(&lfs, &file, "/tmp/",
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_SNAPSHOT) => LFS_ERR_NOENT;
+    lfs_file_open(&lfs, &file, "/tmp/tmp",
+            LFS_O_RDWR | LFS_O_CREAT | LFS_O_SNAPSHOT) => LFS_ERR_NOENT;
     lfs_unmount(&lfs) => 0;
 '''

tests/test_paths.toml

@@ -95,9 +95,9 @@ code = '''
 
     lfs_mkdir(&lfs, "coffee/../milk") => 0;
     lfs_stat(&lfs, "coffee/../milk", &info) => 0;
-    strcmp(info.name, "milk") => 0;
+    assert(strcmp(info.name, "milk") == 0);
     lfs_stat(&lfs, "milk", &info) => 0;
-    strcmp(info.name, "milk") => 0;
+    assert(strcmp(info.name, "milk") == 0);
     lfs_unmount(&lfs) => 0;
 '''
 
@@ -129,9 +129,9 @@ code = '''
     lfs_mount(&lfs, &cfg) => 0;
     lfs_mkdir(&lfs, ".milk") => 0;
     lfs_stat(&lfs, ".milk", &info) => 0;
-    strcmp(info.name, ".milk") => 0;
+    assert(strcmp(info.name, ".milk") == 0);
     lfs_stat(&lfs, "tea/.././.milk", &info) => 0;
-    strcmp(info.name, ".milk") => 0;
+    assert(strcmp(info.name, ".milk") == 0);
     lfs_unmount(&lfs) => 0;
 '''
 
@@ -149,13 +149,13 @@ code = '''
     lfs_mkdir(&lfs, "coffee/coldcoffee") => 0;
 
     lfs_stat(&lfs, "coffee/../../../../../../tea/hottea", &info) => 0;
-    strcmp(info.name, "hottea") => 0;
+    assert(strcmp(info.name, "hottea") == 0);
 
     lfs_mkdir(&lfs, "coffee/../../../../../../milk") => 0;
     lfs_stat(&lfs, "coffee/../../../../../../milk", &info) => 0;
-    strcmp(info.name, "milk") => 0;
+    assert(strcmp(info.name, "milk") == 0);
     lfs_stat(&lfs, "milk", &info) => 0;
-    strcmp(info.name, "milk") => 0;
+    assert(strcmp(info.name, "milk") == 0);
     lfs_unmount(&lfs) => 0;
 '''
 

tests/test_truncate.toml

@@ -392,48 +392,3 @@ code = '''
 
     lfs_unmount(&lfs) => 0;
 '''
-
-[[case]] # noop truncate
-define.MEDIUMSIZE = [32, 2048]
-code = '''
-    lfs_format(&lfs, &cfg) => 0;
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file, "baldynoop",
-            LFS_O_RDWR | LFS_O_CREAT) => 0;
-
-    strcpy((char*)buffer, "hair");
-    size = strlen((char*)buffer);
-    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_write(&lfs, &file, buffer, size) => size;
-
-        // this truncate should do nothing
-        lfs_file_truncate(&lfs, &file, j+size) => 0;
-    }
-    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
-
-    lfs_file_seek(&lfs, &file, 0, LFS_SEEK_SET) => 0;
-    // should do nothing again
-    lfs_file_truncate(&lfs, &file, MEDIUMSIZE) => 0;
-    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
-
-    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hair", size) => 0;
-    }
-    lfs_file_read(&lfs, &file, buffer, size) => 0;
-
-    lfs_file_close(&lfs, &file) => 0;
-    lfs_unmount(&lfs) => 0;
-
-    // still there after reboot?
-    lfs_mount(&lfs, &cfg) => 0;
-    lfs_file_open(&lfs, &file, "baldynoop", LFS_O_RDWR) => 0;
-    lfs_file_size(&lfs, &file) => MEDIUMSIZE;
-    for (lfs_off_t j = 0; j < MEDIUMSIZE; j += size) {
-        lfs_file_read(&lfs, &file, buffer, size) => size;
-        memcmp(buffer, "hair", size) => 0;
-    }
-    lfs_file_read(&lfs, &file, buffer, size) => 0;
-    lfs_file_close(&lfs, &file) => 0;
-    lfs_unmount(&lfs) => 0;
-'''