On 2/24/15 6:51 PM, Filipe Manana wrote:
> This test is motivated by an fsync issue discovered in btrfs.
> The issue was that after adding a new hard link to an existing file
> (one that was created in a past transaction) and fsync'ing the parent
> directory of the new hard link, after the fsync log replay the file's
> inode link count did not get its link count incremented, while the new
> directory entry was visible.
> Also, unlike xfs and ext4, new files under the directory we fsync were
> not being written to the fsync log, nor were any child directories and
> new files and links under the children directories. So this test verifies
> too that btrfs has the same behaviour as xfs and ext4.
>
> The btrfs issue was fixed by the following linux kernel patch:
>
> Btrfs: fix metadata inconsistencies after directory fsync
>
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
>
> V2: Make use of the new function '_require_metadata_journaling' added
> by Eric. Make the test pass on ext3 - unlike ext4 (and xfs), the
> file hello gets all its data synced, so we don't get an empty file
> after the fsync log is replayed.
>
> V3: Make our file 'foo' not empty and verify that after log replay its
> content remains unchanged. Motivated by an issue found during development
> of the btrfs fix.
>
> V4: Updated test description to be more concise. Now it mentions more
> directly what the test does rather than the btrfs issue, which forced
> the reader to infer it and read the whole test.
Thanks. Ok, verified that it passes on ext4 and xfs, too -
Reviewed-by: Eric Sandeen <sandeen@xxxxxxxxxx>
> tests/generic/060 | 172 ++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/generic/060.out | 11 ++++
> tests/generic/group | 1 +
> 3 files changed, 184 insertions(+)
> create mode 100755 tests/generic/060
> create mode 100644 tests/generic/060.out
>
> diff --git a/tests/generic/060 b/tests/generic/060
> new file mode 100755
> index 0000000..2b80078
> --- /dev/null
> +++ b/tests/generic/060
> @@ -0,0 +1,172 @@
> +#! /bin/bash
> +# FS QA Test No. 060
> +#
> +# Test fsync on directories that got new hardlinks added to them and that point
> +# to existing inodes. The goal is to verify that after the fsync log is replayed
> +# the new hardlinks exist and the inodes have a correct link count.
> +# Also test that new hardlinks pointing to new inodes are logged and exist as
> +# well after the fsync log is replayed.
> +#
> +# This test is motivated by an issue discovered in btrfs, where the inode link
> +# counts were incorrect after the fsync log was replayed and the hardlinks for
> +# new inodes were not logged.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
> +# Author: Filipe Manana <fdmanana@xxxxxxxx>
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> +#-----------------------------------------------------------------------
> +#
> +
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1 # failure is the default!
> +
> +_cleanup()
> +{
> + _cleanup_flakey
> + rm -f $tmp.*
> +}
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/dmflakey
> +
> +# real QA test starts here
> +_supported_fs generic
> +_supported_os Linux
> +_need_to_be_root
> +_require_scratch
> +_require_dm_flakey
> +_require_metadata_journaling $SCRATCH_DEV
> +
> +rm -f $seqres.full
> +
> +_scratch_mkfs >> $seqres.full 2>&1
> +_init_flakey
> +_mount_flakey
> +
> +# Create our main test file and directory.
> +$XFS_IO_PROG -f -c "pwrite -S 0xaa 0 8K" $SCRATCH_MNT/foo | _filter_xfs_io
> +mkdir $SCRATCH_MNT/mydir
> +
> +# Make sure all metadata and data are durably persisted.
> +sync
> +
> +# Add a hard link to 'foo' inside our test directory and fsync only the
> +# directory. The btrfs fsync implementation had a bug that caused the new
> +# directory entry to be visible after the fsync log replay but, the inode
> +# of our file remained with a link count of 1.
> +ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_2
> +
> +# Add a few more links and new files.
> +# This is just to verify nothing breaks or gives incorrect results after the
> +# fsync log is replayed.
> +ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/foo_3
> +$XFS_IO_PROG -f -c "pwrite -S 0xff 0 64K" $SCRATCH_MNT/hello | _filter_xfs_io
> +ln $SCRATCH_MNT/hello $SCRATCH_MNT/mydir/hello_2
> +
> +# Add some subdirectories and new files and links to them. This is to verify
> +# that after fsyncing our top level directory 'mydir', all the subdirectories
> +# and their files/links are registered in the fsync log and exist after the
> +# fsync log is replayed.
> +mkdir -p $SCRATCH_MNT/mydir/x/y/z
> +ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/foo_y_link
> +ln $SCRATCH_MNT/foo $SCRATCH_MNT/mydir/x/y/z/foo_z_link
> +touch $SCRATCH_MNT/mydir/x/y/z/qwerty
> +
> +# Now fsync only our top directory.
> +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/mydir
> +
> +# Simulate a crash/power loss.
> +_load_flakey_table $FLAKEY_DROP_WRITES
> +_unmount_flakey
> +
> +_load_flakey_table $FLAKEY_ALLOW_WRITES
> +_mount_flakey
> +
> +# Verify the content of our file 'foo' remains the same as before, 8192 bytes,
> +# all with the value 0xaa.
> +echo "File 'foo' content after log replay:"
> +od -t x1 $SCRATCH_MNT/foo
> +
> +# Remove the first name of our inode. Because of the directory fsync bug, the
> +# inode's link count was 1 instead of 5, so removing the 'foo' name ended up
> +# deleting the inode and the other names became stale directory entries (still
> +# visible to applications). Attempting to remove or access the remaining
> +# dentries pointing to that inode resulted in stale file handle errors and
> +# made it impossible to remove the parent directories since it was impossible
> +# for them to become empty.
> +echo "file 'foo' link count after log replay: $(stat -c %h $SCRATCH_MNT/foo)"
> +rm -f $SCRATCH_MNT/foo
> +
> +# Now verify that all files, links and directories created before fsyncing our
> +# directory exist after the fsync log was replayed.
> +[ -f $SCRATCH_MNT/mydir/foo_2 ] || echo "Link mydir/foo_2 is missing"
> +[ -f $SCRATCH_MNT/mydir/foo_3 ] || echo "Link mydir/foo_3 is missing"
> +[ -f $SCRATCH_MNT/hello ] || echo "File hello is missing"
> +[ -f $SCRATCH_MNT/mydir/hello_2 ] || echo "Link mydir/hello_2 is missing"
> +[ -f $SCRATCH_MNT/mydir/x/y/foo_y_link ] || \
> + echo "Link mydir/x/y/foo_y_link is missing"
> +[ -f $SCRATCH_MNT/mydir/x/y/z/foo_z_link ] || \
> + echo "Link mydir/x/y/z/foo_z_link is missing"
> +[ -f $SCRATCH_MNT/mydir/x/y/z/qwerty ] || \
> + echo "File mydir/x/y/z/qwerty is missing"
> +
> +digest_ok=no
> +hello_digest=$(md5sum $SCRATCH_MNT/hello | cut -d ' ' -f 1)
> +
> +case "$FSTYP" in
> +ext3)
> + # a 64Kb file, with all bytes having the value 0xff
> + [ $hello_digest == "ecb99e6ffea7be1e5419350f725da86b" ] && digest_ok=yes
> + ;;
> +*)
> + # an empty file
> + [ $hello_digest == "d41d8cd98f00b204e9800998ecf8427e" ] && digest_ok=yes
> + ;;
> +esac
> +
> +if [ $digest_ok == "yes" ]; then
> + echo "file 'hello' has expected size and content"
> +else
> + echo "file 'hello' has unexpected size or content"
> +fi
> +
> +# Now remove all files/links, under our test directory 'mydir', and verify we
> +# can remove all the directories.
> +rm -f $SCRATCH_MNT/mydir/x/y/z/*
> +rmdir $SCRATCH_MNT/mydir/x/y/z
> +rm -f $SCRATCH_MNT/mydir/x/y/*
> +rmdir $SCRATCH_MNT/mydir/x/y
> +rmdir $SCRATCH_MNT/mydir/x
> +rm -f $SCRATCH_MNT/mydir/*
> +rmdir $SCRATCH_MNT/mydir
> +
> +# An fsck, run by the fstests framework everytime a test finishes, also detected
> +# the inconsistency and printed the following error message:
> +#
> +# root 5 inode 257 errors 2001, no inode item, link count wrong
> +# unresolved ref dir 258 index 2 namelen 5 name foo_2 filetype 1 errors 4, no inode ref
> +# unresolved ref dir 258 index 3 namelen 5 name foo_3 filetype 1 errors 4, no inode ref
> +
> +status=0
> +exit
> diff --git a/tests/generic/060.out b/tests/generic/060.out
> new file mode 100644
> index 0000000..f86a8fc
> --- /dev/null
> +++ b/tests/generic/060.out
> @@ -0,0 +1,11 @@
> +QA output created by 060
> +wrote 8192/8192 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +wrote 65536/65536 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +File 'foo' content after log replay:
> +0000000 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
> +*
> +0020000
> +file 'foo' link count after log replay: 5
> +file 'hello' has expected size and content
> diff --git a/tests/generic/group b/tests/generic/group
> index f2eb87a..85ff384 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -61,6 +61,7 @@
> 056 metadata auto quick
> 057 metadata auto quick
> 059 metadata auto quick
> +060 metadata auto quick
> 062 attr udf auto quick
> 068 other auto freeze dangerous stress
> 069 rw udf auto quick
>
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