[PATCH] fstests: btrfs: Add test for corrupted orphan qgroup numbers

[Qu Wenruo <wqu@suse.com>]

This bug is exposed by populating a high level qgroup, and then make it
orphan (high level qgroup without child) with old qgroup numbers, and
finally do rescan.

Normally rescan should zero out all qgroups' accounting number, but due
to a kernel bug which won't mark orphan qgroups dirty, their on-disk
data is not updated, thus old numbers remain and cause qgroup
corruption.

Fixed by the following kernel patch:
"btrfs: qgroup: Dirty all qgroups before rescan"

Reported-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 tests/btrfs/170     | 82 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/170.out |  3 ++
 tests/btrfs/group   |  1 +
 3 files changed, 86 insertions(+)
 create mode 100755 tests/btrfs/170
 create mode 100644 tests/btrfs/170.out

diff --git a/tests/btrfs/170 b/tests/btrfs/170
new file mode 100755
index 000000000000..bcf8b5c0e4f3
--- /dev/null
+++ b/tests/btrfs/170
@@ -0,0 +1,82 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 SUSE Linux Products GmbH.  All Rights Reserved.
+#
+# FS QA Test 170
+#
+# Test if btrfs can clear orphan (high level qgroup without child) qgroup's
+# accounting numbers during rescan.
+# Fixed by the following kernel patch:
+# "btrfs: qgroup: Dirty all qgroups before rescan"
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch
+
+_scratch_mkfs > /dev/null 2>&1
+_scratch_mount
+
+
+# Populate the fs
+_run_btrfs_util_prog subvolume create "$SCRATCH_MNT/subvol"
+_pwrite_byte 0xcdcd 0 1M "$SCRATCH_MNT/subvol/file1" | _filter_xfs_io > /dev/null
+
+# Ensure that file reach disk, so it will also appear in snapshot
+sync
+_run_btrfs_util_prog subvolume snapshot "$SCRATCH_MNT/subvol" "$SCRATCH_MNT/snapshot"
+
+
+_run_btrfs_util_prog quota enable "$SCRATCH_MNT"
+_run_btrfs_util_prog quota rescan -w "$SCRATCH_MNT"
+
+# Create high level qgroup
+_run_btrfs_util_prog qgroup create 1/0 "$SCRATCH_MNT"
+
+# Don't use _run_btrfs_util_prog here, as it can return 1 to info user
+# that qgroup is marked inconsistent, this is a bug in btrfs-progs, but
+# to ensure it will work, we just ignore the return value.
+$BTRFS_UTIL_PROG qgroup assign "$SCRATCH_MNT/snapshot" 1/0 "$SCRATCH_MNT"
+
+# Above assign will mark qgroup inconsistent due to the shared extents
+# between subvol/snapshot/high level qgroup, do rescan here
+_run_btrfs_util_prog quota rescan -w "$SCRATCH_MNT"
+
+# Now remove the qgroup relationship and make 1/0 orphan
+# Due to the shared extent outside of 1/0, we will mark qgroup inconsistent
+# and keep the number of qgroup 1/0
+$BTRFS_UTIL_PROG qgroup remove "$SCRATCH_MNT/snapshot" 1/0 "$SCRATCH_MNT"
+
+# Above removal also marks qgroup inconsistent, rescan again
+_run_btrfs_util_prog quota rescan -w "$SCRATCH_MNT"
+
+# After the test, btrfs check will verify qgroup numbers to catch any
+# corruption.
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/170.out b/tests/btrfs/170.out
new file mode 100644
index 000000000000..9002199e48ed
--- /dev/null
+++ b/tests/btrfs/170.out
@@ -0,0 +1,3 @@
+QA output created by 170
+WARNING: quotas may be inconsistent, rescan needed
+WARNING: quotas may be inconsistent, rescan needed
diff --git a/tests/btrfs/group b/tests/btrfs/group
index b616c73d09bf..339c977135c0 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -172,3 +172,4 @@
 167 auto quick replace volume
 168 auto quick send
 169 auto quick send
+170 auto quick qgroup
-- 
2.18.0