Upgrade to LFS 2.0; see MGOS_LFS1_COMPAT for upgrade options

MGOS_LFS1_COMPAT - LFSv1 compatibility mode:
 * 0 - none:  No LFSv1 code in the firmware, attempts to mount LFSv1 filesystem results in an error.
 * 1 - full:  Existing LFSv1 filesystems can be mounted rw and used with no restrictions.
              Firmware contains full LFSv1 code, data is not migrated, mkfs always creates LFSv2.
 * 2 - stomp: LFSv1 filesystems are stomped and reformatted as LFSv2 without preserving the data.
              No LFSv1 code, no data migration, mkfs creates LFSv2.
              This option is suitable for cases where LFS is only used as scratch space.

CL: vfs-fs-lfs: Upgrade to LFS 2.0; see MGOS_LFS1_COMPAT for upgrade options

Author: rojer

.clang-format

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+BasedOnStyle: Google
+AllowShortFunctionsOnASingleLine: false
+SpaceAfterCStyleCast: true
+PointerBindsToType: false
+DerivePointerBinding: false

littlefs/.clang-format

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+DisableFormat: true

src/littlefs/.gitignore renamed to littlefs/.gitignore

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+# Environment variables
+env:
+  global:
+    - CFLAGS=-Werror
+
+# Common test script
+script:
+  # 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"
+
+  # run tests
+  - make test QUIET=1
+
+  # run tests with a few different configurations
+  - make test QUIET=1 CFLAGS+="-DLFS_READ_SIZE=1      -DLFS_CACHE_SIZE=4"
+  - make test QUIET=1 CFLAGS+="-DLFS_READ_SIZE=512    -DLFS_CACHE_SIZE=512 -DLFS_BLOCK_CYCLES=16"
+  - make test QUIET=1 CFLAGS+="-DLFS_BLOCK_COUNT=1023 -DLFS_LOOKAHEAD_SIZE=256"
+
+  - make clean test QUIET=1 CFLAGS+="-DLFS_INLINE_MAX=0"
+  - make clean test QUIET=1 CFLAGS+="-DLFS_NO_INTRINSICS"
+
+  # compile and find the code size with the smallest configuration
+  - make clean size
+        OBJ="$(ls lfs*.o | tr '\n' ' ')"
+        CFLAGS+="-DLFS_NO_ASSERT -DLFS_NO_DEBUG -DLFS_NO_WARN -DLFS_NO_ERROR"
+        | tee sizes
+
+  # update status if we succeeded, compare with master if possible
+  - |
+    if [ "$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 != \"$TRAVIS_COMMIT\")
+                | .statuses[] | select(.context == \"$STAGE/$NAME\").description
+                | capture(\"code size is (?<size>[0-9]+)\").size" \
+            || echo 0)
+
+        STATUS="Passed, code size is ${CURR}B"
+        if [ "$PREV" -ne 0 ]
+        then
+            STATUS="$STATUS ($(python -c "print '%+.2f' % (100*($CURR-$PREV)/$PREV.0)")%)"
+        fi
+    fi
+
+# CI matrix
+jobs:
+  include:
+    # native testing
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-x86
+
+    # cross-compile with ARM (thumb mode)
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-arm
+        - CC="arm-linux-gnueabi-gcc --static -mthumb"
+        - EXEC="qemu-arm"
+      install:
+        - sudo apt-get install gcc-arm-linux-gnueabi qemu-user
+        - arm-linux-gnueabi-gcc --version
+        - qemu-arm -version
+
+    # cross-compile with PowerPC
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-powerpc
+        - CC="powerpc-linux-gnu-gcc --static"
+        - EXEC="qemu-ppc"
+      install:
+        - sudo apt-get install gcc-powerpc-linux-gnu qemu-user
+        - powerpc-linux-gnu-gcc --version
+        - qemu-ppc -version
+
+    # cross-compile with MIPS
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-mips
+        - CC="mips-linux-gnu-gcc --static"
+        - EXEC="qemu-mips"
+      install:
+        - sudo add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu/ xenial main universe"
+        - sudo apt-get -qq update
+        - sudo apt-get install gcc-mips-linux-gnu qemu-user
+        - mips-linux-gnu-gcc --version
+        - qemu-mips -version
+
+    # self-host with littlefs-fuse for fuzz test
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-fuse
+      if: branch !~ -prefix$
+      install:
+        - sudo apt-get install libfuse-dev
+        - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2-alpha
+        - fusermount -V
+        - gcc --version
+      before_script:
+        # setup disk for littlefs-fuse
+        - rm -rf littlefs-fuse/littlefs/*
+        - cp -r $(git ls-tree --name-only HEAD) littlefs-fuse/littlefs
+
+        - mkdir mount
+        - sudo chmod a+rw /dev/loop0
+        - dd if=/dev/zero bs=512 count=4096 of=disk
+        - 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 $(git ls-tree --name-only HEAD) mount/littlefs
+        - cd mount/littlefs
+        - stat .
+        - ls -flh
+        - make -B test_dirs test_files QUIET=1
+
+    # self-host with littlefs-fuse for fuzz test
+    - stage: test
+      env:
+        - STAGE=test
+        - NAME=littlefs-migration
+      if: branch !~ -prefix$
+      install:
+        - sudo apt-get install libfuse-dev
+        - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v2-alpha v2
+        - git clone --depth 1 https://github.com/geky/littlefs-fuse -b v1 v1
+        - fusermount -V
+        - gcc --version
+      before_script:
+        # setup disk for littlefs-fuse
+        - rm -rf v2/littlefs/*
+        - cp -r $(git ls-tree --name-only HEAD) v2/littlefs
+
+        - mkdir mount
+        - sudo chmod a+rw /dev/loop0
+        - dd if=/dev/zero bs=512 count=4096 of=disk
+        - 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 $(git ls-tree --name-only HEAD) mount/littlefs
+        - cd mount/littlefs
+        - stat .
+        - ls -flh
+        - make -B test_dirs test_files QUIET=1
+
+        # attempt to migrate
+        - cd ../..
+        - fusermount -u mount
+
+        - v2/lfs --migrate /dev/loop0
+        - v2/lfs /dev/loop0 mount
+
+        # run self-host test with v2 right where we left off
+        - ls mount
+        - cd mount/littlefs
+        - stat .
+        - ls -flh
+        - make -B test_dirs test_files QUIET=1
+
+    # Automatically create releases
+    - stage: deploy
+      env:
+        - STAGE=deploy
+        - NAME=deploy
+      script:
+        - |
+          bash << 'SCRIPT'
+          set -ev
+          # Find version defined in lfs.h
+          LFS_VERSION=$(grep -ox '#define LFS_VERSION .*' lfs.h | cut -d ' ' -f3)
+          LFS_VERSION_MAJOR=$((0xffff & ($LFS_VERSION >> 16)))
+          LFS_VERSION_MINOR=$((0xffff & ($LFS_VERSION >>  0)))
+          # Grab latests patch from repo tags, default to 0, needs finagling
+          # to get past github's pagination api
+          PREV_URL=https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs/tags/v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.
+          PREV_URL=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" -I \
+              | sed -n '/^Link/{s/.*<\(.*\)>; rel="last"/\1/;p;q0};$q1' \
+              || echo $PREV_URL)
+          LFS_VERSION_PATCH=$(curl -u "$GEKY_BOT_RELEASES" "$PREV_URL" \
+              | jq 'map(.ref | match("\\bv.*\\..*\\.(.*)$";"g")
+                  .captures[].string | tonumber) | max + 1' \
+              || echo 0)
+          # We have our new version
+          LFS_VERSION="v$LFS_VERSION_MAJOR.$LFS_VERSION_MINOR.$LFS_VERSION_PATCH"
+          echo "VERSION $LFS_VERSION"
+          # Check that we're the most recent commit
+          CURRENT_COMMIT=$(curl -f -u "$GEKY_BOT_RELEASES" \
+              https://api.github.com/repos/$TRAVIS_REPO_SLUG/commits/master \
+              | jq -re '.sha')
+          [ "$TRAVIS_COMMIT" == "$CURRENT_COMMIT" ] || exit 0
+          # Create major branch
+          git branch v$LFS_VERSION_MAJOR HEAD
+          # Create major prefix branch
+          git config user.name "geky bot"
+          git config user.email "bot@geky.net"
+          git fetch https://github.com/$TRAVIS_REPO_SLUG.git \
+              --depth=50 v$LFS_VERSION_MAJOR-prefix || true
+          ./scripts/prefix.py lfs$LFS_VERSION_MAJOR
+          git branch v$LFS_VERSION_MAJOR-prefix $( \
+              git commit-tree $(git write-tree) \
+                  $(git rev-parse --verify -q FETCH_HEAD | sed -e 's/^/-p /') \
+                  -p HEAD \
+                  -m "Generated v$LFS_VERSION_MAJOR prefixes")
+          git reset --hard
+          # Update major version branches (vN and vN-prefix)
+          git push https://$GEKY_BOT_RELEASES@github.com/$TRAVIS_REPO_SLUG.git \
+              v$LFS_VERSION_MAJOR \
+              v$LFS_VERSION_MAJOR-prefix
+          # Create patch version tag (vN.N.N)
+          curl -f -u "$GEKY_BOT_RELEASES" -X POST \
+              https://api.github.com/repos/$TRAVIS_REPO_SLUG/git/refs \
+              -d "{
+                  \"ref\": \"refs/tags/$LFS_VERSION\",
+                  \"sha\": \"$TRAVIS_COMMIT\"
+              }"
+          # Create minor release?
+          [[ "$LFS_VERSION" == *.0 ]] || exit 0
+          # Build release notes
+          PREV=$(git tag --sort=-v:refname -l "v*.0" | head -1)
+          if [ ! -z "$PREV" ]
+          then
+              echo "PREV $PREV"
+              CHANGES=$'### Changes\n\n'$( \
+                  git log --oneline $PREV.. --grep='^Merge' --invert-grep)
+              printf "CHANGES\n%s\n\n" "$CHANGES"
+          fi
+          # Create the release
+          curl -f -u "$GEKY_BOT_RELEASES" -X POST \
+              https://api.github.com/repos/$TRAVIS_REPO_SLUG/releases \
+              -d "{
+                  \"tag_name\": \"$LFS_VERSION\",
+                  \"name\": \"${LFS_VERSION%.0}\",
+                  \"draft\": true,
+                  \"body\": $(jq -sR '.' <<< "$CHANGES")
+              }" #"
+          SCRIPT
+
+# Manage statuses
+before_install:
+  - |
+    curl -u "$GEKY_BOT_STATUSES" -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"pending\",
+            \"description\": \"${STATUS:-In progress}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+after_failure:
+  - |
+    curl -u "$GEKY_BOT_STATUSES" -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"failure\",
+            \"description\": \"${STATUS:-Failed}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+after_success:
+  - |
+    curl -u "$GEKY_BOT_STATUSES" -X POST \
+        https://api.github.com/repos/$TRAVIS_REPO_SLUG/statuses/${TRAVIS_PULL_REQUEST_SHA:-$TRAVIS_COMMIT} \
+        -d "{
+            \"context\": \"$STAGE/$NAME\",
+            \"state\": \"success\",
+            \"description\": \"${STATUS:-Passed}\",
+            \"target_url\": \"https://travis-ci.org/$TRAVIS_REPO_SLUG/jobs/$TRAVIS_JOB_ID\"
+        }"
+
+# Job control
+stages:
+    - name: test
+    - name: deploy
+      if: branch = master AND type = push