[PATCH 2/2] generic: test case for reappearing device

[Anand Jain <anajain.sg@gmail.com>]

From: Anand Jain <anand.jain@oracle.com>

Tests how the filesystem handles a device that reappears with a different
MAJ:MIN due to a block layer transport failure.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 tests/generic/809     | 72 +++++++++++++++++++++++++++++++++++++++++++
 tests/generic/809.out |  2 ++
 2 files changed, 74 insertions(+)
 create mode 100755 tests/generic/809
 create mode 100644 tests/generic/809.out

diff --git a/tests/generic/809 b/tests/generic/809
new file mode 100755
index 000000000000..3e9943f9ac85
--- /dev/null
+++ b/tests/generic/809
@@ -0,0 +1,72 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2024 Oracle.  All Rights Reserved.
+#
+# FS QA Test 809
+#
+# Tests how the filesystem handles a device that reappears with a different
+# MAJ:MIN while the old MAJ:MIN is still mounted and in use, due to a block
+# layer transport failure.
+
+. ./common/preamble
+
+_begin_fstest auto quick tempfsid shutdown
+
+_cleanup()
+{
+	local new_blk_handle
+
+	cd /
+	rm -r -f $tmp.*
+	$UMOUNT_PROG $mnt1 &> /dev/null
+	$UMOUNT_PROG $SCRATCH_MNT &> /dev/null
+
+	if [[ ! -b $new_scratch_dev ]]; then
+		echo "_cleanup: failed to restore the scratch device."
+		return
+	fi
+	new_blk_handle=$(_bdev_handle $new_scratch_dev)
+	_devmgt_remove  $new_blk_handle $new_scratch_dev
+	_devmgt_add $new_blk_handle
+
+	[[ -b $SCRATCH_DEV ]] || \
+		echo "_cleanup: failed to restore scratch device."
+}
+
+_require_test
+_require_scratch
+_require_scratch_bdev_delete
+
+mnt1=$TEST_DIR/$seq/mnt1
+rm -r -f $mnt1
+mkdir -p $mnt1
+
+_scratch_mkfs >> /dev/null
+_scratch_mount
+
+$XFS_IO_PROG -fc 'pwrite -S 0x61 0 9000' $SCRATCH_MNT/foo >> $seqres.full
+_mount $SCRATCH_DEV $mnt1
+$UMOUNT_PROG $mnt1
+
+# Ensure data is flushed to disk before the device disappears
+sync
+
+id1=$(lsblk -ndo MAJ:MIN $SCRATCH_DEV)
+scratch_fsid=$(blkid --probe --match-tag UUID $SCRATCH_DEV | \
+	$AWK_PROG '{print $2}' | sed -e 's/UUID=//g' | sed -e 's/\"//g')
+blk_handle=$(_bdev_handle $SCRATCH_DEV)
+_devmgt_remove  $blk_handle $SCRATCH_DEV
+_devmgt_add $blk_handle
+new_scratch_dev=$(blkid -l -o device -t UUID=$scratch_fsid)
+id2=$(lsblk -ndo MAJ:MIN $new_scratch_dev)
+[[ -b $new_scratch_dev ]] || _fail "Device failed to reappear"
+[[ "$id1" != "$id2" ]] || \
+		_not_run "Device cannot reappear with a different major:minor"
+
+# Mount the reappeared device while the old node is still mounted
+# (not supported on XFS).
+[[ $FSTYP == "xfs" ]] && $UMOUNT_PROG $SCRATCH_MNT
+_mount $new_scratch_dev $mnt1
+echo Silence is golden
+status=0
+exit
diff --git a/tests/generic/809.out b/tests/generic/809.out
new file mode 100644
index 000000000000..e90865ca8f8c
--- /dev/null
+++ b/tests/generic/809.out
@@ -0,0 +1,2 @@
+QA output created by 809
+Silence is golden
-- 
2.51.0