btrfs: invalid rmdir issued by send operation

Test that an incremental send operation does not prematurely issues
rmdir operations under a particular scenario (the rmdir operation is
sent before the target directory is empty).

This issue is fixed by the following patch for the linux kernel:

  "Btrfs: incremental send, fix premature rmdir operations"

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

tests/btrfs/129

@@ -0,0 +1,125 @@
+#! /bin/bash
+# FS QA Test No. btrfs/129
+#
+# Test that an incremental send operation does not prematurely issues rmdir
+# operations under a particular scenario (the rmdir operation is sent before
+# the target directory is empty).
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2016 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"
+
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -fr $send_files_dir
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_test
+_require_scratch
+_require_fssum
+
+send_files_dir=$TEST_DIR/btrfs-test-$seq
+
+rm -f $seqres.full
+rm -fr $send_files_dir
+mkdir $send_files_dir
+
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+mkdir $SCRATCH_MNT/a
+mkdir $SCRATCH_MNT/tmp
+mkdir $SCRATCH_MNT/del
+mv $SCRATCH_MNT/tmp $SCRATCH_MNT/del
+mkdir $SCRATCH_MNT/a/c
+mkdir $SCRATCH_MNT/del/x
+
+# Filesystem looks like:
+#
+# .                                                             (ino 256)
+# |--- a/                                                       (ino 257)
+# |    |--- c/                                                  (ino 260)
+# |
+# |--- del/                                                     (ino 259)
+#       |--- tmp/                                               (ino 258)
+#       |--- x/                                                 (ino 261)
+#
+_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1
+
+# When inode 260 was processed, rename operations for it and for inode 258 were
+# issued (the rename for inode 260 must happen before the rename for inode 258).
+# Then immediately after issuing the rename operation for inode 258, and before
+# inode 261 was processed, the send stream issued a rmdir operation for inode
+# 260, which would make the receiver fail with the error ENOTEMPTY because inode
+# 261 was not yet renamed, it was still a child of inode 260 at that time.
+#
+mv $SCRATCH_MNT/a/c $SCRATCH_MNT
+mv $SCRATCH_MNT/del/x $SCRATCH_MNT/a
+mv $SCRATCH_MNT/del/tmp $SCRATCH_MNT/c
+rmdir $SCRATCH_MNT/del
+
+# Filesystem now looks like:
+#
+# .                                                             (ino 256)
+# |--- a/                                                       (ino 257)
+# |    |--- x/                                                  (ino 261)
+# |
+# |--- c/                                                       (ino 260)
+#      |--- tmp/                                                (ino 258)
+#
+_run_btrfs_util_prog subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2
+
+run_check $FSSUM_PROG -A -f -w $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
+run_check $FSSUM_PROG -A -f -w $send_files_dir/2.fssum \
+	-x $SCRATCH_MNT/mysnap2/mysnap1 $SCRATCH_MNT/mysnap2
+
+_run_btrfs_util_prog send $SCRATCH_MNT/mysnap1 -f $send_files_dir/1.snap
+_run_btrfs_util_prog send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \
+	-f $send_files_dir/2.snap
+
+# Now recreate the filesystem by receiving both send streams and verify we get
+# the same content that the original filesystem had.
+_scratch_unmount
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/1.snap
+run_check $FSSUM_PROG -r $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
+_run_btrfs_util_prog receive $SCRATCH_MNT -f $send_files_dir/2.snap
+run_check $FSSUM_PROG -r $send_files_dir/2.fssum $SCRATCH_MNT/mysnap2
+
+echo "Silence is golden"
+status=0
+exit

tests/btrfs/129.out

@@ -0,0 +1,2 @@
+QA output created by 129
+Silence is golden

tests/btrfs/group

@@ -131,3 +131,4 @@
 126 auto quick qgroup
 127 auto quick send
 128 auto quick send
+129 auto quick send