[PATCH v3] btrfs: add fstrim test case on the sprout device

[Anand Jain <anand.jain@oracle.com>]

Add fstrim test case on the sprout device, verify seed device
integrity.

 btrfs: fix unmountable seed device after fstrim

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v3:
  Drop useless write into the sprout device as we are testing the effect of
     fstrim run in the sprout on the seed device.
v2:
  Add _require_fstrim and _require_batched_discard.
  Use FSTRIM_PROG.
  Use _filter_ro_mount to handle the difference in output in different
     mount(8) version.
  Call _scratch_dev_pool_put.
  Add _check_btrfs_filesystem $seed to check the whole seed fs.
  Update in-code comments.

 tests/btrfs/236     | 79 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/236.out |  5 +++
 tests/btrfs/group   |  1 +
 3 files changed, 85 insertions(+)
 create mode 100755 tests/btrfs/236
 create mode 100644 tests/btrfs/236.out

diff --git a/tests/btrfs/236 b/tests/btrfs/236
new file mode 100755
index 000000000000..1fcb3aab8c0c
--- /dev/null
+++ b/tests/btrfs/236
@@ -0,0 +1,79 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Oracle. All Rights Reserved.
+#
+# FS QA Test 236
+#
+# Check seed device integrity after fstrim on the sprout device.
+#
+#  Kernel bug is fixed by the commit:
+#    btrfs: fix unmountable seed device after fstrim
+
+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 $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_require_command "$BTRFS_TUNE_PROG" btrfstune
+_require_fstrim
+_require_scratch_dev_pool 2
+_scratch_dev_pool_get 2
+
+seed=$(echo $SCRATCH_DEV_POOL | $AWK_PROG '{print $1}')
+sprout=$(echo $SCRATCH_DEV_POOL | $AWK_PROG '{print $2}')
+
+_mkfs_dev $seed
+_mount $seed $SCRATCH_MNT
+
+$XFS_IO_PROG -f -c "pwrite -S 0xab 0 1M" $SCRATCH_MNT/foo > /dev/null
+_scratch_unmount
+$BTRFS_TUNE_PROG -S 1 $seed
+
+# Mount the seed device and add the rw device
+_mount $seed $SCRATCH_MNT 2>&1 | _filter_ro_mount | _filter_scratch
+md5sum $SCRATCH_MNT/foo | _filter_scratch
+
+$BTRFS_UTIL_PROG device add -f $sprout $SCRATCH_MNT
+_scratch_unmount
+
+# Now remount writeable sprout device, create some data and run fstrim
+_mount $sprout $SCRATCH_MNT
+_require_batched_discard $SCRATCH_MNT
+
+$FSTRIM_PROG $SCRATCH_MNT
+
+_scratch_unmount
+
+# Verify seed device is all ok
+_mount $seed $SCRATCH_MNT 2>&1 | _filter_ro_mount | _filter_scratch
+md5sum $SCRATCH_MNT/foo | _filter_scratch
+_scratch_unmount
+
+_check_btrfs_filesystem $seed
+
+_scratch_dev_pool_put
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/236.out b/tests/btrfs/236.out
new file mode 100644
index 000000000000..01699b8fc291
--- /dev/null
+++ b/tests/btrfs/236.out
@@ -0,0 +1,5 @@
+QA output created by 236
+mount: device write-protected, mounting read-only
+096003817ad2638000a6836e55866697  SCRATCH_MNT/foo
+mount: device write-protected, mounting read-only
+096003817ad2638000a6836e55866697  SCRATCH_MNT/foo
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 331dd432fac3..5032259244e0 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -238,3 +238,4 @@
 233 auto quick subvolume
 234 auto quick compress rw
 235 auto quick send
+236 auto quick seed trim
-- 
2.27.0