[PATCH v3] fstests: btrfs test if show_devname returns sprout device

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

Test if the show_devname() returns sprout device instead of seed device.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v2: check for presence of needed sprout device.
v3: check for not presence of needed sprout device and break the
silence.

 tests/btrfs/215     | 63 +++++++++++++++++++++++++++++++++++++++++++++
 tests/btrfs/215.out |  2 ++
 tests/btrfs/group   |  1 +
 3 files changed, 66 insertions(+)
 create mode 100755 tests/btrfs/215
 create mode 100644 tests/btrfs/215.out

diff --git a/tests/btrfs/215 b/tests/btrfs/215
new file mode 100755
index 000000000000..5be6d0f60192
--- /dev/null
+++ b/tests/btrfs/215
@@ -0,0 +1,63 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2020 Oracle.  All Rights Reserved.
+#
+# FS QA Test 215
+#
+# Test if the show_devname() returns sprout device instead of seed device.
+#
+# Fixed in kernel patch:
+#   btrfs: btrfs_show_devname don't traverse into the seed fsid
+
+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 $seqres.full
+
+# real QA test starts here
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch_dev_pool 2
+
+_scratch_dev_pool_get 2
+
+seed=$(echo $SCRATCH_DEV_POOL | awk '{print $1}')
+sprout=$(echo $SCRATCH_DEV_POOL | awk '{print $2}')
+
+_mkfs_dev $seed
+$BTRFS_TUNE_PROG -S 1 $seed
+_mount $seed $SCRATCH_MNT >> $seqres.full 2>&1
+cat /proc/self/mounts | grep $seed >> $seqres.full
+$BTRFS_UTIL_PROG device add -f $sprout $SCRATCH_MNT
+cat /proc/self/mounts | grep $sprout >> $seqres.full
+
+# check if the show_devname() returns the sprout device instead of seed device.
+dev=$(grep $SCRATCH_MNT /proc/self/mounts | $AWK_PROG '{print $1}')
+
+if [ "$sprout" != "$dev" ]; then
+	echo "Unexpected device: $dev"
+fi
+echo "Silence is golden"
+
+_scratch_dev_pool_put
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/215.out b/tests/btrfs/215.out
new file mode 100644
index 000000000000..0a11773bbb32
--- /dev/null
+++ b/tests/btrfs/215.out
@@ -0,0 +1,2 @@
+QA output created by 215
+Silence is golden
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 505665b54d61..76c8b78d08f9 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -217,3 +217,4 @@
 212 auto balance dangerous
 213 auto balance dangerous
 214 auto quick send snapshot
+215 auto quick seed
-- 
2.25.1