[PATCH v3 1/7] overlay: add filesystem check helper

["zhangyi (F)" <yi.zhang@huawei.com>]

Add filesystem check helpers for the upcoming fsck.overlay utility,
and hook them to _check_test_fs and _check_scratch_fs. This helper
works only if fsck.overlay exists.

[ _check_test_fs/_check_scratch_fs part picked from Amir's patch, thanks ]

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
---
 common/config  |  1 +
 common/overlay | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 common/rc      |  4 +--
 3 files changed, 83 insertions(+), 2 deletions(-)

diff --git a/common/config b/common/config
index d0fbfe5..0505b71 100644
--- a/common/config
+++ b/common/config
@@ -236,6 +236,7 @@ case "$HOSTOS" in
         export MKFS_REISER4_PROG="`set_prog_path mkfs.reiser4`"
 	export E2FSCK_PROG="`set_prog_path e2fsck`"
 	export TUNE2FS_PROG="`set_prog_path tune2fs`"
+	export FSCK_OVERLAY_PROG="`set_prog_path fsck.overlay`"
         ;;
 esac
 
diff --git a/common/overlay b/common/overlay
index 1da4ab1..e7f0e62 100644
--- a/common/overlay
+++ b/common/overlay
@@ -151,3 +151,83 @@ _require_scratch_overlay_feature()
 	        _notrun "${FSTYP} feature '${feature}' cannot be enabled on ${SCRATCH_DEV}"
 	_scratch_unmount
 }
+
+_overlay_fsck_dirs()
+{
+	local lowerdir=$1
+	local upperdir=$2
+	local workdir=$3
+	local options=$4
+
+	[[ ! -x "$FSCK_OVERLAY_PROG" ]] && return 0
+
+	$FSCK_OVERLAY_PROG -o lowerdir=$lowerdir -o upperdir=$upperdir \
+			   -o workdir=$workdir $options
+}
+
+_overlay_check_dirs()
+{
+	local lowerdir=$1
+	local upperdir=$2
+	local workdir=$3
+	local err=0
+
+	_overlay_fsck_dirs $* $FSCK_OPTIONS >>$tmp.fsck 2>&1
+	if [ $? -ne 0 ]; then
+		_log_err "_overlay_check_fs: overlayfs on $lowerdir,$upperdir,$workdir is inconsistent"
+		echo "*** fsck.overlay output ***"	>>$seqres.full
+		cat $tmp.fsck				>>$seqres.full
+		echo "*** end fsck.overlay output"	>>$seqres.full
+
+		echo "*** mount output ***"		>>$seqres.full
+		_mount					>>$seqres.full
+		echo "*** end mount output"		>>$seqres.full
+		err=1
+	fi
+	rm -f $tmp.fsck
+
+	if [ $err != 0 ]; then
+		status=1
+		if [ "$iam" != "check" ]; then
+			exit 1
+		fi
+		return 1
+	fi
+
+	return 0
+}
+
+_overlay_check_fs()
+{
+	local base_dev=$3
+	local base_mnt=$4
+
+	[ "$FSTYP" = overlay ] || return 0
+
+	# Base fs needs to be mounted to check overlay dirs
+	local mounted=""
+	[ -z "$base_dev" ] || mounted=`_is_mounted $base_dev`
+	[ -n "$mounted" ] || _overlay_base_mount $*
+
+	# No need to umount overlay for dir checks with default -n option
+	_overlay_check_dirs $base_mnt/$OVL_LOWER $base_mnt/$OVL_UPPER \
+			    $base_mnt/$OVL_WORK
+	local ret=$?
+
+	[ -n "$mounted" ] || _overlay_base_unmount "$base_dev" "$base_mnt"
+	return $ret
+}
+
+_check_overlay_test_fs()
+{
+	_overlay_check_fs OVL_BASE_TEST_DEV OVL_BASE_TEST_DIR \
+		"$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR" \
+		$TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS
+}
+
+_check_overlay_scratch_fs()
+{
+	_overlay_check_fs OVL_BASE_SCRATCH_DEV OVL_BASE_SCRATCH_MNT \
+		"$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT" \
+		$OVL_BASE_MOUNT_OPTIONS $SELINUX_MOUNT_OPTIONS
+}
diff --git a/common/rc b/common/rc
index 9216efd..a49f736 100644
--- a/common/rc
+++ b/common/rc
@@ -2537,7 +2537,7 @@ _check_test_fs()
 	# no way to check consistency for GlusterFS
 	;;
     overlay)
-	# no way to check consistency for overlay
+	_check_overlay_test_fs
 	;;
     pvfs2)
 	;;
@@ -2592,7 +2592,7 @@ _check_scratch_fs()
 	# no way to check consistency for GlusterFS
 	;;
     overlay)
-	# no way to check consistency for overlay
+	_check_overlay_scratch_fs
 	;;
     pvfs2)
 	;;
-- 
2.9.5