--- /dev/null
+#! /bin/bash
+# FS QA Test No. 039
+#
+# This test is motivated by an fsync issue discovered in btrfs.
+# The issue was that after fsyncing an inode that got its link count
+# decremented, and the new link count is greater than zero, after the
+# fsync log replay the inode's parent directory metadata became
+# inconsistent - it had a wrong i_size and dangling index entries which
+# prevented the directory from ever being removed (rmdir always failed
+# with -ENOTEMPTY, even if the directory had no more child inodes).
+#
+# The btrfs issue was fixed by the following linux kernel patch:
+#
+# Btrfs: fix directory inconsistency after fsync log replay
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
+# Author: Filipe Manana <fdmanana@suse.com>
+#
+# 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
+}
+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
+
+rm -f $seqres.full
+
+_scratch_mkfs >> $seqres.full 2>&1
+
+_init_flakey
+_mount_flakey
+
+# Create a test file with 2 hard links in the same directory.
+mkdir -p $SCRATCH_MNT/a/b
+echo "hello world" > $SCRATCH_MNT/a/b/foo
+ln $SCRATCH_MNT/a/b/foo $SCRATCH_MNT/a/b/bar
+
+# Make sure all metadata and data are durably persisted.
+sync
+
+# Now remove one of the hard links and fsync the inode.
+rm -f $SCRATCH_MNT/a/b/bar
+$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/a/b/foo
+
+# Simulate a crash/power loss. This makes sure the next mount
+# will see an fsync log and will replay that log.
+
+_load_flakey_table $FLAKEY_DROP_WRITES
+_unmount_flakey
+
+_load_flakey_table $FLAKEY_ALLOW_WRITES
+_mount_flakey
+
+# Remove the last hard link of the file and attempt to remove its parent
+# directory - this failed in btrfs because the fsync log and replay code
+# didn't decrement the parent directory's i_size and left dangling directory
+# index entries - this made the btrfs rmdir implementation always fail with
+# the error -ENOTEMPTY.
+#
+# The dangling directory index entries were visible to user space, but it was
+# impossible to do anything on them (unlink, open, read, write, stat, etc)
+# because the inode they pointed to did not exist anymore.
+#
+# The parent directory's metadata inconsistency (stale index entries) was
+# also detected by btrfs' fsck tool, which is run automatically by the fstests
+# framework when the test finishes. The error message reported by fsck was:
+#
+# root 5 inode 259 errors 2001, no inode item, link count wrong
+# unresolved ref dir 258 index 3 namelen 3 name bar filetype 1 errors 4, no inode ref
+#
+rm -f $SCRATCH_MNT/a/b/*
+rmdir $SCRATCH_MNT/a/b
+rmdir $SCRATCH_MNT/a
+
+echo "Silence is golden"
+status=0
+exit
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