[PATCH 1/3] fstests: add helper _scratch_shutdown_and_syncfs

[Amir Goldstein <amir73il@gmail.com>]

Test xfs/546 has to chain syncfs after shutdown and cannot
use the _scratch_shitdown helper, because after shutdown a fd
cannot be opened to execute syncfs on.

The xfs_io command of chaining syncfs after shutdown is rather
more complex to execute in the derived overlayfs test overlay/087.

Add a helper to abstract this complexity from test writers.
Add a _require statement to match.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 common/rc         | 27 +++++++++++++++++++++++++++
 tests/overlay/087 | 13 +++----------
 tests/xfs/546     |  5 ++---
 3 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/common/rc b/common/rc
index f71cc8f0..d9a8b52e 100644
--- a/common/rc
+++ b/common/rc
@@ -595,6 +595,27 @@ _scratch_shutdown_handle()
 	fi
 }
 
+_scratch_shutdown_and_syncfs()
+{
+	if [ $FSTYP = "overlay" ]; then
+		# In lagacy overlay usage, it may specify directory as
+		# SCRATCH_DEV, in this case OVL_BASE_SCRATCH_DEV
+		# will be null, so check OVL_BASE_SCRATCH_DEV before
+		# running shutdown to avoid shutting down base fs accidently.
+		if [ -z $OVL_BASE_SCRATCH_DEV ]; then
+			_fail "_scratch_shutdown: call _require_scratch_shutdown first in test"
+		fi
+		# This command is complicated a bit because in the case of overlayfs the
+		# syncfs fd needs to be opened before shutdown and it is different from the
+		# shutdown fd, so we cannot use the _scratch_shutdown() helper.
+		# Filter out xfs_io output of active fds.
+		$XFS_IO_PROG -x -c "open $(_scratch_shutdown_handle)" -c 'shutdown -f ' \
+				-c close -c syncfs $SCRATCH_MNT | grep -vF '[00'
+	else
+		$XFS_IO_PROG -x -c 'shutdown -f ' -c syncfs $SCRATCH_MNT
+	fi
+}
+
 _move_mount()
 {
 	local mnt=$1
@@ -4102,6 +4123,12 @@ _require_scratch_shutdown()
 	_scratch_unmount
 }
 
+_require_scratch_shutdown_and_syncfs()
+{
+	_require_xfs_io_command syncfs
+	_require_scratch_shutdown
+}
+
 _check_s_dax()
 {
 	local target=$1
diff --git a/tests/overlay/087 b/tests/overlay/087
index a5afb0d5..2ad069db 100755
--- a/tests/overlay/087
+++ b/tests/overlay/087
@@ -32,9 +32,8 @@ _begin_fstest auto quick mount shutdown
 
 
 # Modify as appropriate.
-_require_xfs_io_command syncfs
 _require_scratch_nocheck
-_require_scratch_shutdown
+_require_scratch_shutdown_and_syncfs
 
 [ "$OVL_BASE_FSTYP" == "xfs" ] || \
 	_notrun "base fs $OVL_BASE_FSTYP has unknown behavior with syncfs after shutdown"
@@ -43,19 +42,13 @@ _require_scratch_shutdown
 # bother checking the filesystem afterwards since we never wrote anything.
 echo "=== syncfs after shutdown"
 _scratch_mount
-# This command is complicated a bit because in the case of overlayfs the
-# syncfs fd needs to be opened before shutdown and it is different from the
-# shutdown fd, so we cannot use the _scratch_shutdown() helper.
-# Filter out xfs_io output of active fds.
-$XFS_IO_PROG -x -c "open $(_scratch_shutdown_handle)" -c 'shutdown -f ' -c close -c syncfs $SCRATCH_MNT | \
-	grep -vF '[00'
+_scratch_shutdown_and_syncfs
 
 # Now repeat the same test with a volatile overlayfs mount and expect no error
 _scratch_unmount
 echo "=== syncfs after shutdown (volatile)"
 _scratch_mount -o volatile
-$XFS_IO_PROG -x -c "open $(_scratch_shutdown_handle)" -c 'shutdown -f ' -c close -c syncfs $SCRATCH_MNT | \
-	grep -vF '[00'
+_scratch_shutdown_and_syncfs
 
 # success, all done
 status=0
diff --git a/tests/xfs/546 b/tests/xfs/546
index 316ffc50..c50d41a6 100755
--- a/tests/xfs/546
+++ b/tests/xfs/546
@@ -27,14 +27,13 @@ _begin_fstest auto quick shutdown
 
 
 # Modify as appropriate.
-_require_xfs_io_command syncfs
 _require_scratch_nocheck
-_require_scratch_shutdown
+_require_scratch_shutdown_and_syncfs
 
 # Reuse the fs formatted when we checked for the shutdown ioctl, and don't
 # bother checking the filesystem afterwards since we never wrote anything.
 _scratch_mount
-$XFS_IO_PROG -x -c 'shutdown -f ' -c syncfs $SCRATCH_MNT
+_scratch_shutdown_and_syncfs
 
 # success, all done
 status=0
-- 
2.34.1