btrfs: test orphan item cleanup

This test tests three conditions where orphan items need to be
cleaned up:

1) Default subvolume is fs tree root (mkfs default)
2) Default subvolume has been set explicitly to another subvolumei
   (set-default)
3) Looking up a subvolume during a traversal

In the kernel, these three cases use separate mechanisms to look up
the subvolumes. There was a bug in the kernel where case #2 wasn't
getting handled and so orphan items would never be cleaned up if the
default subvolume was explicitly set. This issue was fixed with the
upstream commit: btrfs: cleanup orphans while looking up default
subvolume.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

tests/btrfs/085

@@ -0,0 +1,161 @@
+#!/bin/bash
+# FS QA Test No. btrfs/085
+#
+# Tests to ensure that orphan items are properly created and cleaned up
+# on next mount.
+#
+# There are three cases where orphan items may be cleaned up:
+# 1) Default subvolume is fs tree root (mkfs default)
+# 2) Default subvolume is explicitly created subvolume
+#    (i.e. btrfs subvol set-default)
+# 3) Non-default subvolume lookup
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2015 SUSE.  All Rights Reserved.
+#
+# 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 $tmp.*
+}
+
+trap "_cleanup ; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/dmflakey
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+_require_dm_flakey
+_need_to_be_root
+
+BTRFS_DEBUG_TREE_PROG="`set_prog_path btrfs-debug-tree`"
+_require_command "$BTRFS_DEBUG_TREE_PROG" btrfs-debug-tree
+
+rm -f $seqres.full
+
+has_orphan_item()
+{
+	INO=$1
+	if $BTRFS_DEBUG_TREE_PROG $SCRATCH_DEV | \
+		grep -q "key (ORPHAN ORPHAN_ITEM $INO)"; then
+		return 0
+	fi
+	return 1
+}
+
+test_orphan()
+{
+	PRECMD=$1
+	SUB=0
+
+	_scratch_mkfs >> $seqres.full 2>&1
+	_init_flakey
+
+	_mount_flakey
+
+	$PRECMD
+
+	TESTPATH=$SCRATCH_MNT/testdir/testfile
+	DIR=$(dirname $TESTPATH)
+
+	[ -d "$DIR" ] || mkdir -p $DIR
+
+	SIZE=$(( 1024 * 1024 ))
+	run_check dd if=/dev/zero of=$TESTPATH bs=$SIZE count=1
+
+	INO=$(stat -c %i $TESTPATH)
+
+	# Orphan item won't be created if the file doesn't make it to disk
+	sync
+
+	# Open and delete the file
+	exec 27<$TESTPATH
+	rm -f $TESTPATH
+
+	# Ensure the unlink (and orphan item creation) hits the disk
+	sync
+
+	# Turn off writes before closing so the orphan item will be left behind
+	_load_flakey_table $FLAKEY_DROP_WRITES
+
+	# Close the file so we can umount
+	exec 27>&-
+
+	# Orphan item should be on disk if operating correctly
+	_unmount_flakey
+	_load_flakey_table $FLAKEY_ALLOW_WRITES
+	if ! has_orphan_item $INO; then
+		echo "ERROR: No orphan item found after umount."
+		return
+	fi
+	_mount_flakey
+
+	# If $DIR is a subvolume, this will cause a lookup and orphan cleanup
+	(cd $DIR; true)
+
+	# Orphan item will be cleaned up during mount but won't be on
+	# disk until there's a sync.
+	sync
+
+	_unmount_flakey
+	if has_orphan_item $INO; then
+		echo "ERROR: Orphan item found after successful mount/sync."
+	fi
+	_cleanup_flakey
+}
+
+new_subvolume()
+{
+	_run_btrfs_util_prog subvol create $SCRATCH_MNT/testdir
+}
+
+new_default()
+{
+	new_subvolume
+	SUB=$($BTRFS_UTIL_PROG subvol list $SCRATCH_MNT |awk '{print $2}')
+	_run_btrfs_util_prog subvol set-default $SUB $SCRATCH_MNT
+
+	_unmount_flakey
+	_mount_flakey
+}
+
+echo "Testing with fs root as default subvolume"
+test_orphan true
+
+echo "Testing with explicit default subvolume"
+test_orphan new_default
+
+echo "Testing with orphan on non-default subvolume"
+test_orphan new_subvolume
+
+status=0
+exit

tests/btrfs/085.out

@@ -0,0 +1,4 @@
+QA output created by 085
+Testing with fs root as default subvolume
+Testing with explicit default subvolume
+Testing with orphan on non-default subvolume

tests/btrfs/group

@@ -87,3 +87,4 @@
 082 auto quick remount
 083 auto quick send
 084 auto quick send
+085 auto quick metadata subvol