btrfs: add fstrim test case on the sprout device

Add fstrim test case on the sprout device, verify seed device
integrity. Targeting kernel commit 5e753a817b2d ("btrfs: fix
unmountable seed device after fstrim")

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

tests/btrfs/238

@@ -0,0 +1,79 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Oracle. All Rights Reserved.
+#
+# FS QA Test 238
+#
+# 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

tests/btrfs/238.out

@@ -0,0 +1,5 @@
+QA output created by 238
+mount: device write-protected, mounting read-only
+096003817ad2638000a6836e55866697  SCRATCH_MNT/foo
+mount: device write-protected, mounting read-only
+096003817ad2638000a6836e55866697  SCRATCH_MNT/foo

tests/btrfs/group

@@ -240,3 +240,4 @@
 235 auto quick send
 236 auto quick log
 237 auto quick zone balance
+238 auto quick seed trim