new file mode 100755
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+#! /bin/bash
+# FS QA Test No. btrfs/135
+#
+# Test that an incremental send operation works when in both snapshots there are
+# two directory inodes that have the same number but different generations and
+# have an entry with the same name that corresponds to different inodes in each
+# snapshot.
+#
+#-----------------------------------------------------------------------
+# Copyright (C) 2017 Synology Inc. All Rights Reserved.
+# Author: Robbie Ko <robbieko@synology.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
+
+touch $SCRATCH_MNT/f
+mkdir $SCRATCH_MNT/d1
+mkdir $SCRATCH_MNT/d259_old
+mv $SCRATCH_MNT/d1 $SCRATCH_MNT/d259_old/d1
+
+# Filesystem looks like:
+#
+# . (ino 256)
+# |--- f (ino 257)
+# |
+# |--- d259_old/ (ino 259)
+# |--- d1/ (ino 258)
+#
+$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT \
+ $SCRATCH_MNT/mysnap1 > /dev/null
+
+$BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f \
+ $send_files_dir/1.snap 2>&1 1>/dev/null | _filter_scratch
+
+_scratch_unmount
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+mkdir $SCRATCH_MNT/d1
+mkdir $SCRATCH_MNT/dir258
+mkdir $SCRATCH_MNT/dir259
+mv $SCRATCH_MNT/d1 $SCRATCH_MNT/dir259/d1
+
+# Filesystem now looks like:
+#
+# . (ino 256)
+# |--- dir258/ (ino 258)
+# |
+# |--- dir259/ (ino 259)
+# |--- d1/ (ino 257)
+#
+# Notice that at this point all inodes have a generation with value 7, which is
+# the generation value for a brand new filesystem.
+
+# Now create the second snapshot. This makes the filesystem's current generation
+# value to increase to the value 8, due to a transaction commit performed by the
+# snapshot creation ioctl.
+$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT \
+ $SCRATCH_MNT/mysnap2 > /dev/null
+
+# Now receive the first snapshot created in the first filesystem.
+# Before creating any inodes, the receive command creates the first snapshot,
+# which causes a transaction commit and therefore bumps the filesystem's current
+# generation to the value 9. All the inodes created end up getting a generation
+# value of 9 and the snapshot's root inode (256) gets a generation value of 8.
+$BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $send_files_dir/1.snap > /dev/null
+rm $send_files_dir/1.snap
+
+$FSSUM_PROG -A -f -w $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
+$FSSUM_PROG -A -f -w $send_files_dir/2.fssum $SCRATCH_MNT/mysnap2
+
+$BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f \
+ $send_files_dir/1.snap 2>&1 1>/dev/null | _filter_scratch
+$BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 $SCRATCH_MNT/mysnap2 \
+ -f $send_files_dir/2.snap 2>&1 1>/dev/null | _filter_scratch
+
+# Now recreate the filesystem by receiving both send streams and verify we get
+# the same content that the original filesystem had.
+_scratch_unmount
+_scratch_mkfs >>$seqres.full 2>&1
+_scratch_mount
+
+$BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $send_files_dir/1.snap > /dev/null
+$FSSUM_PROG -r $send_files_dir/1.fssum $SCRATCH_MNT/mysnap1
+# The receive of the incremental send stream used to fail because it contained
+# a rmdir operation with an invalid path. The output of the receive command,
+# with verbose mode (argument -vv), was the following:
+#
+# utimes
+# unlink f
+# mkdir o257-7-0
+# mkdir o259-7-0
+# rename o257-7-0 -> o259-7-0/d1
+# chown o259-7-0/d1 - uid=0, gid=0
+# chmod o259-7-0/d1 - mode=0755
+# utimes o259-7-0/d1
+# rmdir o258-9-0
+# ERROR: rmdir o258-9-0 failed: No such file or directory
+#
+# When the kernel was computing the send stream and processing inode 258, it
+# noticed that in both snapshots this inode is a direct child of inode 259, and
+# that in both snapshots inode 259 as an entry with the name "d1". Because of
+# that it decided (incorrectly) to issue an rmdir operation using the orphanized
+# name of the inode 258 from the parent snapshot (which has a generation of 9).
+# However that decision to send an rmdir operation due to the dentry collision
+# was incorrect because the inodes with number 259 in both snapshots are not the
+# same, they have different generations.
+#
+$BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $send_files_dir/2.snap > /dev/null
+$FSSUM_PROG -r $send_files_dir/2.fssum $SCRATCH_MNT/mysnap2
+
+status=0
+exit
new file mode 100644
@@ -0,0 +1,8 @@
+QA output created by 135
+At subvol SCRATCH_MNT/mysnap1
+At subvol mysnap1
+At subvol SCRATCH_MNT/mysnap1
+At subvol SCRATCH_MNT/mysnap2
+At subvol mysnap1
+OK
+OK
@@ -136,3 +136,4 @@
132 auto enospc
133 auto quick send
134 auto quick send
+135 auto quick send