X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Ftests%2Fsanity-lfsck.sh;h=66eba9579632c77d02fed49d5b318c32c4529adc;hp=34ee6eddc05ec6872e7e6966081d8671f5e65e93;hb=698209700faf51c227f9ba16626de5ed70fa97c8;hpb=a274b711ef583b16910fea47cf3545edabca1062

diff --git a/lustre/tests/sanity-lfsck.sh b/lustre/tests/sanity-lfsck.sh
index 34ee6ed..66eba95 100644
--- a/lustre/tests/sanity-lfsck.sh
+++ b/lustre/tests/sanity-lfsck.sh
@@ -7,7 +7,10 @@
 set -e
 
 ONLY=${ONLY:-"$*"}
+
+#Bug number for excepting test
 ALWAYS_EXCEPT="$SANITY_LFSCK_EXCEPT"
+
 [ "$SLOW" = "no" ] && EXCEPT_SLOW=""
 # UPDATE THE COMMENT ABOVE WITH BUG NUMBERS WHEN CHANGING ALWAYS_EXCEPT!
 
@@ -19,23 +22,34 @@ init_logging
 
 require_dsh_mds || exit 0
 
+load_modules
+
+if ! check_versions; then
+	skip "It is NOT necessary to test lfsck under interoperation mode"
+	exit 0
+fi
+
+[[ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.3.60) ]] &&
+	skip "Need MDS version at least 2.3.60" && exit 0
+
+LTIME=${LTIME:-120}
+
 SAVED_MDSSIZE=${MDSSIZE}
 SAVED_OSTSIZE=${OSTSIZE}
 SAVED_OSTCOUNT=${OSTCOUNT}
 # use small MDS + OST size to speed formatting time
 # do not use too small MDSSIZE/OSTSIZE, which affect the default journal size
 MDSSIZE=100000
+[ $(facet_fstype $SINGLEMDS) == zfs ] && MDSSIZE=300000
 OSTSIZE=100000
-# no need too much OSTs, to reduce the format/start/stop overhead
+[ $(facet_fstype ost1) == zfs ] && OSTSIZE=300000
+
+# no need too many OSTs, to reduce the format/start/stop overhead
+cleanupall
 [ $OSTCOUNT -gt 4 ] && OSTCOUNT=4
 
 # build up a clean test environment.
-formatall
-setupall
-
-[[ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.3.60) ]] &&
-	skip "Need MDS version at least 2.3.60" && check_and_cleanup_lustre &&
-	exit 0
+REFORMAT="yes" check_and_setup_lustre
 
 [[ $(lustre_version_code $SINGLEMDS) -le $(version_code 2.4.90) ]] &&
 	ALWAYS_EXCEPT="$ALWAYS_EXCEPT 2c"
@@ -43,13 +57,14 @@ setupall
 [[ $(lustre_version_code ost1) -lt $(version_code 2.5.55) ]] &&
 	ALWAYS_EXCEPT="$ALWAYS_EXCEPT 11 12 13 14 15 16 17 18 19 20 21"
 
-[ $(facet_fstype $SINGLEMDS) = "zfs" ] &&
-# bug number for skipped test:        LU-4970
-	ALWAYS_EXCEPT="$ALWAYS_EXCEPT 14"
+[[ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.6.50) ]] &&
+	ALWAYS_EXCEPT="$ALWAYS_EXCEPT 2d 2e 3 22 23 24 25 26 27 28 29 30 31"
 
-build_test_filter
+# DNE does not support striped directory on zfs-based backend yet.
+[ $(facet_fstype $SINGLEMDS) != ldiskfs ] &&
+	ALWAYS_EXCEPT="$ALWAYS_EXCEPT 31"
 
-$LCTL set_param debug=+lfsck > /dev/null || true
+build_test_filter
 
 MDT_DEV="${FSNAME}-MDT0000"
 OST_DEV="${FSNAME}-OST0000"
@@ -68,6 +83,7 @@ SHOW_LAYOUT_ON_OST="do_facet ost1 \
 		$LCTL get_param -n obdfilter.${OST_DEV}.lfsck_layout"
 MOUNT_OPTS_SCRUB="-o user_xattr"
 MOUNT_OPTS_NOSCRUB="-o user_xattr,noscrub"
+MOUNT_OPTS_SKIP_LFSCK="-o user_xattr,skip_lfsck"
 
 lfsck_prep() {
 	local ndirs=$1
@@ -103,6 +119,46 @@ lfsck_prep() {
 	echo "prepared $(date)."
 }
 
+run_e2fsck_on_mdt0() {
+	[ $(facet_fstype $SINGLEMDS) != ldiskfs ] && return
+
+	stop $SINGLEMDS > /dev/null || error "(0) Fail to the stop MDT0"
+	run_e2fsck $(facet_active_host $SINGLEMDS) $(mdsdevname 1) "-n" |
+		grep "Fix? no" && {
+		run_e2fsck $(facet_active_host $SINGLEMDS) $(mdsdevname 1) "-n"
+		error "(2) Detected inconsistency on MDT0"
+	}
+	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_NOSCRUB > /dev/null ||
+		error "(3) Fail to start MDT0"
+}
+
+wait_all_targets_blocked() {
+	local com=$1
+	local status=$2
+	local err=$3
+
+	local count=$(do_facet mds1 \
+		     "$LCTL lfsck_query -t $com -M ${FSNAME}-MDT0000 -w |
+		      awk '/^${com}_mdts_${status}/ { print \\\$2 }'")
+	[[ $count -eq $MDSCOUNT ]] || {
+		do_facet mds1 "$LCTL lfsck_query -t $com -M ${FSNAME}-MDT0000"
+		error "($err) only $count of $MDSCOUNT MDTs are in ${status}"
+	}
+}
+
+wait_all_targets() {
+	local com=$1
+	local status=$2
+	local err=$3
+
+	wait_update_facet mds1 "$LCTL lfsck_query -t $com -M ${FSNAME}-MDT0000 |
+		awk '/^${com}_mdts_${status}/ { print \\\$2 }'" \
+		"$MDSCOUNT" $LTIME || {
+		do_facet mds1 "$LCTL lfsck_query -t $com -M ${FSNAME}-MDT0000"
+		error "($err) some MDTs are not in ${status}"
+	}
+}
+
 test_0() {
 	lfsck_prep 3 3
 
@@ -131,7 +187,7 @@ test_0() {
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(9) unexpected status"
 	}
@@ -145,7 +201,7 @@ test_0() {
 	$START_NAMESPACE -r || error "(11) Fail to reset LFSCK!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(12) unexpected status"
 	}
@@ -160,9 +216,6 @@ test_0() {
 run_test 0 "Control LFSCK manually"
 
 test_1a() {
-	[ $(facet_fstype $SINGLEMDS) != ldiskfs ] &&
-		skip "OI Scrub not implemented for ZFS" && return
-
 	lfsck_prep 1 1
 
 	#define OBD_FAIL_FID_INDIR	0x1501
@@ -174,7 +227,7 @@ test_1a() {
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -189,6 +242,8 @@ test_1a() {
 	[ $repaired -eq 1 ] ||
 		error "(5) Fail to repair crashed FID-in-dirent: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(6) Fail to start client!"
 
 	#define OBD_FAIL_FID_LOOKUP	0x1505
@@ -217,7 +272,7 @@ test_1b()
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -230,9 +285,11 @@ test_1b()
 			 awk '/^updated_phase1/ { print $2 }')
 
 	[ $repaired -eq 1 ] ||
-		error "(5) Fail to repair missed FID-in-LMA: $repaired"
+		error "(5) Fail to repair the missing FID-in-LMA: $repaired"
 
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(6) Fail to start client!"
 
 	#define OBD_FAIL_FID_LOOKUP	0x1505
@@ -241,7 +298,46 @@ test_1b()
 
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
 }
-run_test 1b "LFSCK can find out and repair missed FID-in-LMA"
+run_test 1b "LFSCK can find out and repair the missing FID-in-LMA"
+
+test_1c() {
+	lfsck_prep 1 1
+
+	#define OBD_FAIL_FID_IGIF	0x1504
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1504
+	touch $DIR/$tdir/dummy
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+	umount_client $MOUNT
+	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(4) unexpected status"
+	}
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dirent_repaired/ { print $2 }')
+	# for interop with old server
+	[ -z "$repaired" ] &&
+		repaired=$($SHOW_NAMESPACE |
+			 awk '/^updated_phase1/ { print $2 }')
+
+	[ $repaired -eq 1 ] ||
+		error "(5) Fail to repair lost FID-in-dirent: $repaired"
+
+	run_e2fsck_on_mdt0
+
+	mount_client $MOUNT || error "(6) Fail to start client!"
+
+	#define OBD_FAIL_FID_LOOKUP	0x1505
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1505
+	ls $DIR/$tdir/ > /dev/null || error "(7) no FID-in-dirent."
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+}
+run_test 1c "LFSCK can find out and repair lost FID-in-dirent"
 
 test_2a() {
 	lfsck_prep 1 1
@@ -255,7 +351,7 @@ test_2a() {
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -265,11 +361,13 @@ test_2a() {
 	# for interop with old server
 	[ -z "$repaired" ] &&
 		repaired=$($SHOW_NAMESPACE |
-			 awk '/^updated_phase1/ { print $2 }')
+			 awk '/^updated_phase2/ { print $2 }')
 
 	[ $repaired -eq 1 ] ||
 		error "(5) Fail to repair crashed linkEA: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(6) Fail to start client!"
 
 	stat $DIR/$tdir/dummy | grep "Links: 1" > /dev/null ||
@@ -295,7 +393,7 @@ test_2b()
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -305,6 +403,8 @@ test_2b()
 	[ $repaired -eq 1 ] ||
 		error "(5) Fail to repair crashed linkEA: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(6) Fail to start client!"
 
 	stat $DIR/$tdir/dummy | grep "Links: 1" > /dev/null ||
@@ -330,7 +430,7 @@ test_2c()
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -340,6 +440,8 @@ test_2c()
 	[ $repaired -eq 1 ] ||
 		error "(5) Fail to repair crashed linkEA: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(6) Fail to start client!"
 
 	stat $DIR/$tdir/dummy | grep "Links: 1" > /dev/null ||
@@ -352,6 +454,114 @@ test_2c()
 }
 run_test 2c "LFSCK can find out and remove repeated linkEA entry"
 
+test_2d()
+{
+	lfsck_prep 1 1
+
+	#define OBD_FAIL_LFSCK_NO_LINKEA	0x161d
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x161d
+	touch $DIR/$tdir/dummy
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+	umount_client $MOUNT
+	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(4) unexpected status"
+	}
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^linkea_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(5) Fail to repair crashed linkEA: $repaired"
+
+	run_e2fsck_on_mdt0
+
+	mount_client $MOUNT || error "(6) Fail to start client!"
+
+	stat $DIR/$tdir/dummy | grep "Links: 1" > /dev/null ||
+		error "(7) Fail to stat $DIR/$tdir/dummy"
+
+	local dummyfid=$($LFS path2fid $DIR/$tdir/dummy)
+	local dummyname=$($LFS fid2path $DIR $dummyfid)
+	[ "$dummyname" == "$DIR/$tdir/dummy" ] ||
+		error "(8) Fail to repair linkEA: $dummyfid $dummyname"
+}
+run_test 2d "LFSCK can recover the missing linkEA entry"
+
+test_2e()
+{
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0 on MDT1"
+
+	#define OBD_FAIL_LFSCK_LINKEA_CRASH	0x1603
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1603
+	$LFS mkdir -i 0 $DIR/$tdir/d0/d1 || error "(2) Fail to mkdir d1 on MDT0"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	$START_NAMESPACE -r -A || error "(3) Fail to start LFSCK for namespace!"
+
+	wait_all_targets_blocked namespace completed 4
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^linkea_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(5) Fail to repair crashed linkEA: $repaired"
+
+	local fid=$($LFS path2fid $DIR/$tdir/d0/d1)
+	local name=$($LFS fid2path $DIR $fid)
+	[ "$name" == "$DIR/$tdir/d0/d1" ] ||
+		error "(6) Fail to repair linkEA: $fid $name"
+}
+run_test 2e "namespace LFSCK can verify remote object linkEA"
+
+test_3()
+{
+	lfsck_prep 4 4
+
+	mkdir $DIR/$tdir/dummy || error "(1) Fail to mkdir"
+	ln $DIR/$tdir/d0/f0 $DIR/$tdir/dummy/f0 || error "(2) Fail to hardlink"
+	ln $DIR/$tdir/d0/f1 $DIR/$tdir/dummy/f1 || error "(3) Fail to hardlink"
+
+	$LFS mkdir -i 0 $DIR/$tdir/edir || error "(4) Fail to mkdir"
+	touch $DIR/$tdir/edir/f0 || error "(5) Fail to touch"
+	touch $DIR/$tdir/edir/f1 || error "(6) Fail to touch"
+
+	#define OBD_FAIL_LFSCK_LINKEA_CRASH	0x1603
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1603
+	ln $DIR/$tdir/edir/f0 $DIR/$tdir/edir/w0 || error "(7) Fail to hardlink"
+
+	#define OBD_FAIL_LFSCK_LINKEA_MORE	0x1604
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1604
+	ln $DIR/$tdir/edir/f1 $DIR/$tdir/edir/w1 || error "(8) Fail to hardlink"
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	$START_NAMESPACE -r || error "(9) Fail to start LFSCK for namespace!"
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(10) unexpected status"
+	}
+
+	local checked=$($SHOW_NAMESPACE |
+			awk '/^checked_phase2/ { print $2 }')
+	[ $checked -ge 4 ] ||
+		error "(11) Fail to check multiple-linked object: $checked"
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^multiple_linked_repaired/ { print $2 }')
+	[ $repaired -ge 2 ] ||
+		error "(12) Fail to repair multiple-linked object: $repaired"
+}
+run_test 3 "LFSCK can verify multiple-linked objects"
+
 test_4()
 {
 	[ $(facet_fstype $SINGLEMDS) != ldiskfs ] &&
@@ -371,7 +581,7 @@ test_4()
 	$START_NAMESPACE -r || error "(4) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^flags/ { print \\\$2 }'" "inconsistent" 6 || {
+		awk '/^flags/ { print \\\$2 }'" "inconsistent" 32 || {
 		$SHOW_NAMESPACE
 		error "(5) unexpected status"
 	}
@@ -383,7 +593,7 @@ test_4()
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(7) unexpected status"
 	}
@@ -401,6 +611,8 @@ test_4()
 	[ $repaired -ge 9 ] ||
 		error "(9) Fail to re-generate FID-in-dirent: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(10) Fail to start client!"
 
 	#define OBD_FAIL_FID_LOOKUP	0x1505
@@ -429,7 +641,7 @@ test_5()
 	$START_NAMESPACE -r || error "(4) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^flags/ { print \\\$2 }'" "inconsistent,upgrade" 6 || {
+		awk '/^flags/ { print \\\$2 }'" "inconsistent,upgrade" 32 || {
 		$SHOW_NAMESPACE
 		error "(5) unexpected status"
 	}
@@ -441,7 +653,7 @@ test_5()
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(7) unexpected status"
 	}
@@ -459,6 +671,8 @@ test_5()
 	[ $repaired -ge 2 ] ||
 		error "(9) Fail to generate FID-in-dirent for IGIF: $repaired"
 
+	run_e2fsck_on_mdt0
+
 	mount_client $MOUNT || error "(10) Fail to start client!"
 
 	#define OBD_FAIL_FID_LOOKUP	0x1505
@@ -493,7 +707,7 @@ test_6a() {
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x80001608
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "failed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "failed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -519,7 +733,7 @@ test_6a() {
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(8) unexpected status"
 	}
@@ -544,7 +758,7 @@ test_6b() {
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x80001609
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "failed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "failed" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
@@ -570,6 +784,8 @@ test_6b() {
 	local D_POS1=$($SHOW_NAMESPACE |
 		       awk '/^latest_start_position/ { print $4 }')
 
+	echo "Additional debug for 6b"
+	$SHOW_NAMESPACE
 	if [ "$D_POS0" == "N/A" -o "$D_POS1" == "N/A" ]; then
 		[[ $O_POS0 -lt $O_POS1 ]] ||
 			error "(7.1) $O_POS1 is not larger than $O_POS0"
@@ -581,7 +797,7 @@ test_6b() {
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(8) unexpected status"
 	}
@@ -606,11 +822,11 @@ test_7a()
 	echo "stop $SINGLEMDS"
 	stop $SINGLEMDS > /dev/null || error "(4) Fail to stop MDS!"
 
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	echo "start $SINGLEMDS"
 	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_SCRUB > /dev/null ||
 		error "(5) Fail to start MDS!"
 
-	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
 		awk '/^status/ { print \\\$2 }'" "completed" 30 || {
@@ -635,19 +851,20 @@ test_7b()
 	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 6 || {
+		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 32 || {
 		$SHOW_NAMESPACE
 		error "(4) unexpected status"
 	}
 
+	umount_client $MOUNT
 	echo "stop $SINGLEMDS"
 	stop $SINGLEMDS > /dev/null || error "(5) Fail to stop MDS!"
 
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	echo "start $SINGLEMDS"
 	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_SCRUB > /dev/null ||
 		error "(6) Fail to start MDS!"
 
-	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
 		awk '/^status/ { print \\\$2 }'" "completed" 30 || {
@@ -706,7 +923,7 @@ test_8()
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x80001609
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "failed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "failed" 32 || {
 		$SHOW_NAMESPACE
 		error "(10) unexpected status"
 	}
@@ -733,6 +950,21 @@ test_8()
 	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_SCRUB > /dev/null ||
 		error "(14) Fail to start MDS!"
 
+	local timeout=$(max_recovery_time)
+	local timer=0
+
+	while [ $timer -lt $timeout ]; do
+		STATUS=$(do_facet $SINGLEMDS "$LCTL get_param -n \
+			mdt.${MDT_DEV}.recovery_status |
+			awk '/^status/ { print \\\$2 }'")
+		[ "$STATUS" != "RECOVERING" ] && break;
+		sleep 1
+		timer=$((timer + 1))
+	done
+
+	[ $timer != $timeout ] ||
+		error "(14.1) recovery timeout"
+
 	STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
 	[ "$STATUS" == "crashed" ] ||
 		error "(15) Expect 'crashed', but got '$STATUS'"
@@ -755,17 +987,54 @@ test_8()
 	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_SCRUB > /dev/null ||
 		error "(19) Fail to start MDS!"
 
+	timer=0
+	while [ $timer -lt $timeout ]; do
+		STATUS=$(do_facet $SINGLEMDS "$LCTL get_param -n \
+			mdt.${MDT_DEV}.recovery_status |
+			awk '/^status/ { print \\\$2 }'")
+		[ "$STATUS" != "RECOVERING" ] && break;
+		sleep 1
+		timer=$((timer + 1))
+	done
+
+	[ $timer != $timeout ] ||
+		error "(19.1) recovery timeout"
+
 	STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
 	[ "$STATUS" == "paused" ] ||
 		error "(20) Expect 'paused', but got '$STATUS'"
 
+	echo "stop $SINGLEMDS"
+	stop $SINGLEMDS > /dev/null || error "(20.1) Fail to stop MDS!"
+
+	echo "start $SINGLEMDS without resume LFSCK"
+	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_SKIP_LFSCK > /dev/null ||
+		error "(20.2) Fail to start MDS!"
+
+	timer=0
+	while [ $timer -lt $timeout ]; do
+		STATUS=$(do_facet $SINGLEMDS "$LCTL get_param -n \
+			mdt.${MDT_DEV}.recovery_status |
+			awk '/^status/ { print \\\$2 }'")
+		[ "$STATUS" != "RECOVERING" ] && break;
+		sleep 1
+		timer=$((timer + 1))
+	done
+
+	[ $timer != $timeout ] ||
+		error "(20.3) recovery timeout"
+
+	STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
+	[ "$STATUS" == "paused" ] ||
+		error "(20.4) Expect 'paused', but got '$STATUS'"
+
 	#define OBD_FAIL_LFSCK_DELAY3		0x1602
 	do_facet $SINGLEMDS $LCTL set_param fail_val=2 fail_loc=0x1602
 
 	$START_NAMESPACE || error "(21) Fail to start LFSCK for namespace!"
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 6 || {
+		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 32 || {
 		$SHOW_NAMESPACE
 		error "(22) unexpected status"
 	}
@@ -777,7 +1046,7 @@ test_8()
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(24) unexpected status"
 	}
@@ -793,28 +1062,34 @@ test_9a() {
 		return 0
 	fi
 
-	lfsck_prep 70 70
+	check_mount_and_prep
+	$LFS mkdir -i 0 $DIR/$tdir/lfsck || error "(1) Fail to mkdir lfsck"
+	$LFS setstripe -c 1 -i -1 $DIR/$tdir/lfsck
+	createmany -o $DIR/$tdir/lfsck/f 5000
 
 	local BASE_SPEED1=100
 	local RUN_TIME1=10
-	$START_NAMESPACE -r -s $BASE_SPEED1 || error "(3) Fail to start LFSCK!"
+	$START_LAYOUT -r -s $BASE_SPEED1 || error "(2) Fail to start LFSCK!"
 
 	sleep $RUN_TIME1
-	STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
+	STATUS=$($SHOW_LAYOUT | awk '/^status/ { print $2 }')
 	[ "$STATUS" == "scanning-phase1" ] ||
 		error "(3) Expect 'scanning-phase1', but got '$STATUS'"
 
-	local SPEED=$($SHOW_NAMESPACE |
+	local SPEED=$($SHOW_LAYOUT |
 		      awk '/^average_speed_phase1/ { print $2 }')
 
 	# There may be time error, normally it should be less than 2 seconds.
 	# We allow another 20% schedule error.
 	local TIME_DIFF=2
-	# MAX_MARGIN = 1.2 = 12 / 10
+	# MAX_MARGIN = 1.3 = 13 / 10
 	local MAX_SPEED=$((BASE_SPEED1 * (RUN_TIME1 + TIME_DIFF) / \
-			   RUN_TIME1 * 12 / 10))
-	[ $SPEED -lt $MAX_SPEED ] ||
-		error "(4) Got speed $SPEED, expected less than $MAX_SPEED"
+			   RUN_TIME1 * 13 / 10))
+	[ $SPEED -lt $MAX_SPEED ] || {
+		$SHOW_LAYOUT
+		log "speed1: $BASE_SPEED1 time1: $RUN_TIME1"
+		error "(4) Speed $SPEED, expected < $MAX_SPEED"
+	}
 
 	# adjust speed limit
 	local BASE_SPEED2=300
@@ -823,28 +1098,40 @@ test_9a() {
 		$LCTL set_param -n mdd.${MDT_DEV}.lfsck_speed_limit $BASE_SPEED2
 	sleep $RUN_TIME2
 
-	SPEED=$($SHOW_NAMESPACE | awk '/^average_speed_phase1/ { print $2 }')
-	# MIN_MARGIN = 0.8 = 8 / 10
+	SPEED=$($SHOW_LAYOUT | awk '/^average_speed_phase1/ { print $2 }')
+	# MIN_MARGIN = 0.7 = 7 / 10
 	local MIN_SPEED=$(((BASE_SPEED1 * (RUN_TIME1 - TIME_DIFF) + \
 			    BASE_SPEED2 * (RUN_TIME2 - TIME_DIFF)) / \
-			   (RUN_TIME1 + RUN_TIME2) * 8 / 10))
-	# Account for slow ZFS performance - LU-4934
-	[ $SPEED -gt $MIN_SPEED ] || [ $(facet_fstype $SINGLEMDS) -eq zfs ] ||
-		error "(5) Got speed $SPEED, expected more than $MIN_SPEED"
+			   (RUN_TIME1 + RUN_TIME2) * 7 / 10))
+	[ $SPEED -gt $MIN_SPEED ] || {
+		if [ $(facet_fstype $SINGLEMDS) != ldiskfs ]; then
+			error_ignore LU-5624 \
+			"(5.1) Got speed $SPEED, expected more than $MIN_SPEED"
+		else
+			error \
+			"(5.2) Got speed $SPEED, expected more than $MIN_SPEED"
+		fi
+	}
 
-	# MAX_MARGIN = 1.2 = 12 / 10
+	# MAX_MARGIN = 1.3 = 13 / 10
 	MAX_SPEED=$(((BASE_SPEED1 * (RUN_TIME1 + TIME_DIFF) + \
 		      BASE_SPEED2 * (RUN_TIME2 + TIME_DIFF)) / \
-		     (RUN_TIME1 + RUN_TIME2) * 12 / 10))
-	[ $SPEED -lt $MAX_SPEED ] ||
-		error "(6) Got speed $SPEED, expected less than $MAX_SPEED"
+		     (RUN_TIME1 + RUN_TIME2) * 13 / 10))
+	[ $SPEED -lt $MAX_SPEED ] || {
+		$SHOW_LAYOUT
+		log "speed1: $BASE_SPEED1 time1: $RUN_TIME1"
+		log "speed2: $BASE_SPEED2 time2: $RUN_TIME2"
+		error "(6) Speed $SPEED, expected < $MAX_SPEED"
+	}
 
-	do_facet $SINGLEMDS \
-		$LCTL set_param -n mdd.${MDT_DEV}.lfsck_speed_limit 0
+	do_nodes $(comma_list $(mdts_nodes)) \
+		$LCTL set_param -n mdd.*.lfsck_speed_limit 0
+	do_nodes $(comma_list $(osts_nodes)) \
+		$LCTL set_param -n obdfilter.*.lfsck_speed_limit 0
 
 	wait_update_facet $SINGLEMDS \
-	    "$LCTL get_param -n mdd.${MDT_DEV}.lfsck_namespace|\
-	    awk '/^status/ { print \\\$2 }'" "completed" 30 ||
+		"$LCTL get_param -n mdd.${MDT_DEV}.lfsck_layout |
+		awk '/^status/ { print \\\$2 }'" "completed" 30 ||
 		error "(7) Failed to get expected 'completed'"
 }
 run_test 9a "LFSCK speed control (1)"
@@ -893,11 +1180,14 @@ test_9b() {
 	# There may be time error, normally it should be less than 2 seconds.
 	# We allow another 20% schedule error.
 	local TIME_DIFF=2
-	# MAX_MARGIN = 1.2 = 12 / 10
+	# MAX_MARGIN = 1.3 = 13 / 10
 	local MAX_SPEED=$((BASE_SPEED1 * (RUN_TIME1 + TIME_DIFF) / \
-			  RUN_TIME1 * 12 / 10))
-	[ $SPEED -lt $MAX_SPEED ] ||
-		error "(8) Got speed $SPEED, expected less than $MAX_SPEED"
+			  RUN_TIME1 * 13 / 10))
+	[ $SPEED -lt $MAX_SPEED ] || {
+		$SHOW_NAMESPACE
+		log "speed1: $BASE_SPEED1 time1: $RUN_TIME1"
+		error "(8) Speed $SPEED, expected < $MAX_SPEED"
+	}
 
 	# adjust speed limit
 	local BASE_SPEED2=150
@@ -907,25 +1197,38 @@ test_9b() {
 	sleep $RUN_TIME2
 
 	SPEED=$($SHOW_NAMESPACE | awk '/^average_speed_phase2/ { print $2 }')
-	# MIN_MARGIN = 0.8 = 8 / 10
+	# MIN_MARGIN = 0.7 = 7 / 10
 	local MIN_SPEED=$(((BASE_SPEED1 * (RUN_TIME1 - TIME_DIFF) + \
 			    BASE_SPEED2 * (RUN_TIME2 - TIME_DIFF)) / \
-			   (RUN_TIME1 + RUN_TIME2) * 8 / 10))
-	[ $SPEED -gt $MIN_SPEED ] ||[ $(facet_fstype $SINGLEMDS) -eq zfs ] ||
-		error "(9) Got speed $SPEED, expected more than $MIN_SPEED"
+			   (RUN_TIME1 + RUN_TIME2) * 7 / 10))
+	[ $SPEED -gt $MIN_SPEED ] || {
+		if [ $(facet_fstype $SINGLEMDS) != ldiskfs ]; then
+			error_ignore LU-5624 \
+			"(9.1) Got speed $SPEED, expected more than $MIN_SPEED"
+		else
+			error \
+			"(9.2) Got speed $SPEED, expected more than $MIN_SPEED"
+		fi
+	}
 
-	# MAX_MARGIN = 1.2 = 12 / 10
+	# MAX_MARGIN = 1.3 = 13 / 10
 	MAX_SPEED=$(((BASE_SPEED1 * (RUN_TIME1 + TIME_DIFF) + \
 		      BASE_SPEED2 * (RUN_TIME2 + TIME_DIFF)) / \
-		     (RUN_TIME1 + RUN_TIME2) * 12 / 10))
-	[ $SPEED -lt $MAX_SPEED ] ||
-		error "(10) Got speed $SPEED, expected less than $MAX_SPEED"
+		     (RUN_TIME1 + RUN_TIME2) * 13 / 10))
+	[ $SPEED -lt $MAX_SPEED ] || {
+		$SHOW_NAMESPACE
+		log "speed1: $BASE_SPEED1 time1: $RUN_TIME1"
+		log "speed2: $BASE_SPEED2 time2: $RUN_TIME2"
+		error "(10) Speed $SPEED, expected < $MAX_SPEED"
+	}
 
-	do_facet $SINGLEMDS \
-		$LCTL set_param -n mdd.${MDT_DEV}.lfsck_speed_limit 0
+	do_nodes $(comma_list $(mdts_nodes)) \
+		$LCTL set_param -n mdd.*.lfsck_speed_limit 0
+	do_nodes $(comma_list $(osts_nodes)) \
+		$LCTL set_param -n obdfilter.*.lfsck_speed_limit 0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(11) unexpected status"
 	}
@@ -994,11 +1297,13 @@ test_10()
 	[ "$STATUS" == "scanning-phase1" ] ||
 		error "(15) Expect 'scanning-phase1', but got '$STATUS'"
 
-	do_facet $SINGLEMDS \
-		$LCTL set_param -n mdd.${MDT_DEV}.lfsck_speed_limit 0
+	do_nodes $(comma_list $(mdts_nodes)) \
+		$LCTL set_param -n mdd.*.lfsck_speed_limit 0
+	do_nodes $(comma_list $(osts_nodes)) \
+		$LCTL set_param -n obdfilter.*.lfsck_speed_limit 0
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_namespace |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_NAMESPACE
 		error "(16) unexpected status"
 	}
@@ -1051,7 +1356,7 @@ test_11a() {
 
 	wait_update_facet ost1 "$LCTL get_param -n \
 		obdfilter.${OST_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT_ON_OST
 		error "(6) unexpected status"
 	}
@@ -1069,9 +1374,16 @@ test_11b() {
 	echo "set fail_loc=0x160d to skip the updating LAST_ID on-disk"
 	#define OBD_FAIL_LFSCK_SKIP_LASTID	0x160d
 	do_facet ost1 $LCTL set_param fail_loc=0x160d
-	createmany -o $DIR/$tdir/f 64
+
+	local count=$(precreated_ost_obj_count 0 0)
+
+	createmany -o $DIR/$tdir/f $((count + 32))
+
+	local proc_path="${FSNAME}-OST0000-osc-MDT0000"
+	local seq=$(do_facet mds1 $LCTL get_param -n \
+		    osp.${proc_path}.prealloc_last_seq)
 	local lastid1=$(do_facet ost1 "lctl get_param -n \
-		obdfilter.${ost1_svc}.last_id" | grep 0x100000000 |
+		obdfilter.${ost1_svc}.last_id" | grep $seq |
 		awk -F: '{ print $2 }')
 
 	umount_client $MOUNT
@@ -1085,7 +1397,7 @@ test_11b() {
 
 	for ((i = 0; i < 60; i++)); do
 		lastid2=$(do_facet ost1 "lctl get_param -n \
-			obdfilter.${ost1_svc}.last_id" | grep 0x100000000 |
+			obdfilter.${ost1_svc}.last_id" | grep $seq |
 			awk -F: '{ print $2 }')
 		[ ! -z $lastid2 ] && break;
 		sleep 1
@@ -1100,7 +1412,7 @@ test_11b() {
 
 	wait_update_facet ost1 "$LCTL get_param -n \
 		obdfilter.${OST_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT_ON_OST
 		error "(6) unexpected status"
 	}
@@ -1112,10 +1424,11 @@ test_11b() {
 
 	echo "the on-disk LAST_ID should have been rebuilt"
 	wait_update_facet ost1 "$LCTL get_param -n \
-		obdfilter.${ost1_svc}.last_id | grep 0x100000000 |
+		obdfilter.${ost1_svc}.last_id | grep $seq |
 		awk -F: '{ print \\\$2 }'" "$lastid1" 60 || {
-		$LCTL get_param -n obdfilter.${ost1_svc}.last_id
-		error "(9) expect lastid1 0x100000000:$lastid1"
+		do_facet ost1 $LCTL get_param -n \
+		obdfilter.${ost1_svc}.last_id
+		error "(9) expect lastid1 $seq:$lastid1"
 	}
 
 	do_facet ost1 $LCTL set_param fail_loc=0
@@ -1123,9 +1436,8 @@ test_11b() {
 }
 run_test 11b "LFSCK can rebuild crashed last_id"
 
-test_12() {
-	[ $MDSCOUNT -lt 2 ] &&
-		skip "We need at least 2 MDSes for test_12" && exit 0
+test_12a() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
 
 	check_mount_and_prep
 	for k in $(seq $MDSCOUNT); do
@@ -1139,64 +1451,37 @@ test_12() {
 		-s 1 -r || error "(2) Fail to start LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'scanning-phase1' status."
-	for k in $(seq $MDSCOUNT); do
-		local STATUS=$(do_facet mds${k} $LCTL get_param -n \
-				mdd.$(facet_svc mds${k}).lfsck_namespace |
-				awk '/^status/ { print $2 }')
-		[ "$STATUS" == "scanning-phase1" ] ||
-		error "(3) MDS${k} Expect 'scanning-phase1', but got '$STATUS'"
-	done
+	wait_all_targets namespace scanning-phase1 3
 
 	echo "Stop namespace LFSCK on all targets by single lctl command."
 	do_facet mds1 $LCTL lfsck_stop -M ${FSNAME}-MDT0000 -A ||
 		error "(4) Fail to stop LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'stopped' status."
-	for k in $(seq $MDSCOUNT); do
-		local STATUS=$(do_facet mds${k} $LCTL get_param -n \
-				mdd.$(facet_svc mds${k}).lfsck_namespace |
-				awk '/^status/ { print $2 }')
-		[ "$STATUS" == "stopped" ] ||
-			error "(5) MDS${k} Expect 'stopped', but got '$STATUS'"
-	done
+	wait_all_targets_blocked namespace stopped 5
 
 	echo "Re-start namespace LFSCK on all targets by single command (-s 0)."
 	do_facet mds1 $LCTL lfsck_start -M ${FSNAME}-MDT0000 -t namespace -A \
 		-s 0 -r || error "(6) Fail to start LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'completed' status."
-	for k in $(seq $MDSCOUNT); do
-		wait_update_facet mds${k} "$LCTL get_param -n \
-			mdd.$(facet_svc mds${k}).lfsck_namespace |
-			awk '/^status/ { print \\\$2 }'" "completed" 8 ||
-			error "(7) MDS${k} is not the expected 'completed'"
-	done
+	wait_all_targets_blocked namespace completed 7
+
+	start_full_debug_logging
 
 	echo "Start layout LFSCK on all targets by single command (-s 1)."
 	do_facet mds1 $LCTL lfsck_start -M ${FSNAME}-MDT0000 -t layout -A \
 		-s 1 -r || error "(8) Fail to start LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'scanning-phase1' status."
-	for k in $(seq $MDSCOUNT); do
-		local STATUS=$(do_facet mds${k} $LCTL get_param -n \
-				mdd.$(facet_svc mds${k}).lfsck_layout |
-				awk '/^status/ { print $2 }')
-		[ "$STATUS" == "scanning-phase1" ] ||
-		error "(9) MDS${k} Expect 'scanning-phase1', but got '$STATUS'"
-	done
+	wait_all_targets layout scanning-phase1 9
 
 	echo "Stop layout LFSCK on all targets by single lctl command."
 	do_facet mds1 $LCTL lfsck_stop -M ${FSNAME}-MDT0000 -A ||
 		error "(10) Fail to stop LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'stopped' status."
-	for k in $(seq $MDSCOUNT); do
-		local STATUS=$(do_facet mds${k} $LCTL get_param -n \
-				mdd.$(facet_svc mds${k}).lfsck_layout |
-				awk '/^status/ { print $2 }')
-		[ "$STATUS" == "stopped" ] ||
-			error "(11) MDS${k} Expect 'stopped', but got '$STATUS'"
-	done
+	wait_all_targets_blocked layout stopped 11
 
 	for k in $(seq $OSTCOUNT); do
 		local STATUS=$(do_facet ost${k} $LCTL get_param -n \
@@ -1211,17 +1496,34 @@ test_12() {
 		-s 0 -r || error "(13) Fail to start LFSCK on all devices!"
 
 	echo "All the LFSCK targets should be in 'completed' status."
-	for k in $(seq $MDSCOUNT); do
-		# The LFSCK status query internal is 30 seconds. For the case
-		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
-		# time to guarantee the status sync up.
-		wait_update_facet mds${k} "$LCTL get_param -n \
-			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
-			error "(14) MDS${k} is not the expected 'completed'"
-	done
+	wait_all_targets_blocked layout completed 14
+
+	stop_full_debug_logging
+}
+run_test 12a "single command to trigger LFSCK on all devices"
+
+test_12b() {
+	check_mount_and_prep
+
+	echo "Start LFSCK without '-M' specified."
+	do_facet mds1 $LCTL lfsck_start -A -r ||
+		error "(0) Fail to start LFSCK without '-M'"
+
+	wait_all_targets_blocked namespace completed 1
+	wait_all_targets_blocked layout completed 2
+
+	local count=$(do_facet mds1 $LCTL dl |
+		      awk '{ print $3 }' | grep mdt | wc -l)
+	if [ $count -gt 1 ]; then
+		echo
+		echo "Start layout LFSCK on the node with multipe targets,"
+		echo "but not specify '-M'/'-A' option. Should get failure."
+		echo
+		do_facet mds1 $LCTL lfsck_start -t layout -r &&
+			error "(3) Start layout LFSCK should fail" || true
+	fi
 }
-run_test 12 "single command to trigger LFSCK on all devices"
+run_test 12b "auto detect Lustre device"
 
 test_13() {
 	echo "#####"
@@ -1235,7 +1537,9 @@ test_13() {
 	echo "Inject failure stub to simulate bad lmm_oi"
 	#define OBD_FAIL_LFSCK_BAD_LMMOI	0x160f
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x160f
-	createmany -o $DIR/$tdir/f 32
+	createmany -o $DIR/$tdir/f 1
+	$LFS setstripe -E 1M -S 1M -E -1 $DIR/$tdir/f1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f1"
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
 
 	echo "Trigger layout LFSCK to find out the bad lmm_oi and fix them"
@@ -1243,33 +1547,44 @@ test_13() {
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(2) unexpected status"
 	}
 
 	local repaired=$($SHOW_LAYOUT |
 			 awk '/^repaired_others/ { print $2 }')
-	[ $repaired -eq 32 ] ||
+	[ $repaired -eq 2 ] ||
 		error "(3) Fail to repair crashed lmm_oi: $repaired"
 }
 run_test 13 "LFSCK can repair crashed lmm_oi"
 
-test_14() {
+test_14a() {
 	echo "#####"
 	echo "The OST-object referenced by the MDT-object should be there;"
-	echo "otherwise, the LFSCK should re-create the missed OST-object."
+	echo "otherwise, the LFSCK should re-create the missing OST-object."
+	echo "without '--delay-create-ostobj' option."
 	echo "#####"
 
 	check_mount_and_prep
 	$LFS setstripe -c 1 -i 0 $DIR/$tdir
 
-	local count=$(precreated_ost_obj_count 0 0)
-
 	echo "Inject failure stub to simulate dangling referenced MDT-object"
 	#define OBD_FAIL_LFSCK_DANGLING	0x1610
 	do_facet ost1 $LCTL set_param fail_loc=0x1610
-	createmany -o $DIR/$tdir/f $((count + 32))
+	local count=$(precreated_ost_obj_count 0 0)
+
+	createmany -o $DIR/$tdir/f $((count + 16)) ||
+		error "(0.1) Fail to create $DIR/$tdir/fx"
+	touch $DIR/$tdir/guard0
+
+	for ((i = 0; i < 16; i++)); do
+		$LFS setstripe -E 512K -S 256K -o 0 -E 2M \
+			$DIR/$tdir/f_comp${i} ||
+			error "(0.2) Fail to create $DIR/$tdir/f_comp${i}"
+	done
+	touch $DIR/$tdir/guard1
+
 	do_facet ost1 $LCTL set_param fail_loc=0
 
 	start_full_debug_logging
@@ -1277,7 +1592,7 @@ test_14() {
 	# exhaust other pre-created dangling cases
 	count=$(precreated_ost_obj_count 0 0)
 	createmany -o $DIR/$tdir/a $count ||
-		error "(0) Fail to create $count files."
+		error "(0.5) Fail to create $count files."
 
 	echo "'ls' should fail because of dangling referenced MDT-object"
 	ls -ail $DIR/$tdir > /dev/null 2>&1 && error "(1) ls should fail."
@@ -1287,7 +1602,7 @@ test_14() {
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(3) unexpected status"
 	}
@@ -1297,62 +1612,166 @@ test_14() {
 	[ $repaired -ge 32 ] ||
 		error "(4) Fail to repair dangling reference: $repaired"
 
-	echo "'ls' should fail because it will not repair dangling by default"
-	ls -ail $DIR/$tdir > /dev/null 2>&1 && error "(5) ls should fail."
+	echo "'stat' should fail because of not repair dangling by default"
+	stat $DIR/$tdir/guard0 > /dev/null 2>&1 &&
+		error "(5.1) stat should fail"
+	stat $DIR/$tdir/guard1 > /dev/null 2>&1 &&
+		error "(5.2) stat should fail"
 
 	echo "Trigger layout LFSCK to repair dangling reference"
 	$START_LAYOUT -r -c || error "(6) Fail to start LFSCK for layout!"
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(7) unexpected status"
 	}
 
+	# There may be some async LFSCK updates in processing, wait for
+	# a while until the target reparation has been done. LU-4970.
+
+	echo "'stat' should success after layout LFSCK repairing"
+	wait_update_facet client "stat $DIR/$tdir/guard0 |
+		awk '/Size/ { print \\\$2 }'" "0" 32 || {
+		stat $DIR/$tdir/guard0
+		$SHOW_LAYOUT
+		error "(8.1) unexpected size"
+	}
+
+	wait_update_facet client "stat $DIR/$tdir/guard1 |
+		awk '/Size/ { print \\\$2 }'" "0" 32 || {
+		stat $DIR/$tdir/guard1
+		$SHOW_LAYOUT
+		error "(8.2) unexpected size"
+	}
+
 	repaired=$($SHOW_LAYOUT |
 			 awk '/^repaired_dangling/ { print $2 }')
 	[ $repaired -ge 32 ] ||
-		error "(8) Fail to repair dangling reference: $repaired"
+		error "(9) Fail to repair dangling reference: $repaired"
 
-	echo "'ls' should success after layout LFSCK repairing"
-	ls -ail $DIR/$tdir > /dev/null || error "(9) ls should success."
 	stop_full_debug_logging
+
+	echo "stopall to cleanup object cache"
+	stopall > /dev/null
+	echo "setupall"
+	setupall > /dev/null
 }
-run_test 14 "LFSCK can repair MDT-object with dangling reference"
+run_test 14a "LFSCK can repair MDT-object with dangling LOV EA reference (1)"
 
-test_15a() {
+test_14b() {
 	echo "#####"
-	echo "If the OST-object referenced by the MDT-object back points"
-	echo "to some non-exist MDT-object, then the LFSCK should repair"
-	echo "the OST-object to back point to the right MDT-object."
+	echo "The OST-object referenced by the MDT-object should be there;"
+	echo "otherwise, the LFSCK should re-create the missing OST-object."
+	echo "with '--delay-create-ostobj' option."
 	echo "#####"
 
 	check_mount_and_prep
 	$LFS setstripe -c 1 -i 0 $DIR/$tdir
 
-	echo "Inject failure stub to make the OST-object to back point to"
-	echo "non-exist MDT-object."
-	#define OBD_FAIL_LFSCK_UNMATCHED_PAIR1	0x1611
+	echo "Inject failure stub to simulate dangling referenced MDT-object"
+	#define OBD_FAIL_LFSCK_DANGLING	0x1610
+	do_facet ost1 $LCTL set_param fail_loc=0x1610
+	local count=$(precreated_ost_obj_count 0 0)
 
-	do_facet ost1 $LCTL set_param fail_loc=0x1611
+	createmany -o $DIR/$tdir/f $((count + 31))
+	touch $DIR/$tdir/guard
+	do_facet ost1 $LCTL set_param fail_loc=0
+
+	start_full_debug_logging
+
+	# exhaust other pre-created dangling cases
+	count=$(precreated_ost_obj_count 0 0)
+	createmany -o $DIR/$tdir/a $count ||
+		error "(0) Fail to create $count files."
+
+	echo "'ls' should fail because of dangling referenced MDT-object"
+	ls -ail $DIR/$tdir > /dev/null 2>&1 && error "(1) ls should fail."
+
+	echo "Trigger layout LFSCK to find out dangling reference"
+	$START_LAYOUT -r -o -d || error "(2) Fail to start LFSCK for layout!"
+
+	wait_all_targets_blocked layout completed 3
+
+	local repaired=$($SHOW_LAYOUT |
+			 awk '/^repaired_dangling/ { print $2 }')
+	[ $repaired -ge 32 ] ||
+		error "(4) Fail to repair dangling reference: $repaired"
+
+	echo "'stat' should fail because of not repair dangling by default"
+	stat $DIR/$tdir/guard > /dev/null 2>&1 && error "(5) stat should fail"
+
+	echo "Trigger layout LFSCK to repair dangling reference"
+	$START_LAYOUT -r -o -c -d || error "(6) Fail to start LFSCK for layout!"
+
+	wait_all_targets_blocked layout completed 7
+
+	# There may be some async LFSCK updates in processing, wait for
+	# a while until the target reparation has been done. LU-4970.
+
+	echo "'stat' should success after layout LFSCK repairing"
+	wait_update_facet client "stat $DIR/$tdir/guard |
+		awk '/Size/ { print \\\$2 }'" "0" 32 || {
+		stat $DIR/$tdir/guard
+		$SHOW_LAYOUT
+		error "(8) unexpected size"
+	}
+
+	repaired=$($SHOW_LAYOUT |
+			 awk '/^repaired_dangling/ { print $2 }')
+	[ $repaired -ge 32 ] ||
+		error "(9) Fail to repair dangling reference: $repaired"
+
+	stop_full_debug_logging
+
+	echo "stopall to cleanup object cache"
+	stopall > /dev/null
+	echo "setupall"
+	setupall > /dev/null
+}
+run_test 14b "LFSCK can repair MDT-object with dangling LOV EA reference (2)"
+
+test_15a() {
+	echo "#####"
+	echo "If the OST-object referenced by the MDT-object back points"
+	echo "to some non-exist MDT-object, then the LFSCK should repair"
+	echo "the OST-object to back point to the right MDT-object."
+	echo "#####"
+
+	check_mount_and_prep
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir
+
+	echo "Inject failure stub to make the OST-object to back point to"
+	echo "non-exist MDT-object."
+	#define OBD_FAIL_LFSCK_UNMATCHED_PAIR1	0x1611
+
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0x1611
 	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=1
+	$LFS setstripe -E 1M -S 256K -c 1 -E -1 -S 512K -c $OSTCOUNT \
+		$DIR/$tdir/f1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f1"
+	# 'dd' will trigger punch RPC firstly on every OST-objects.
+	# So even though some OST-object will not be write by 'dd',
+	# as long as it is allocated (may be NOT allocated in pfl_3b)
+	# its layout information will be set also.
+	dd if=/dev/zero of=$DIR/$tdir/f1 bs=4K count=257
 	cancel_lru_locks osc
-	do_facet ost1 $LCTL set_param fail_loc=0
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0
 
 	echo "Trigger layout LFSCK to find out unmatched pairs and fix them"
 	$START_LAYOUT -r || error "(1) Fail to start LFSCK for layout!"
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(2) unexpected status"
 	}
 
 	local repaired=$($SHOW_LAYOUT |
 			 awk '/^repaired_unmatched_pair/ { print $2 }')
-	[ $repaired -eq 1 ] ||
+	[ $repaired -ge 3 ] ||
 		error "(3) Fail to repair unmatched pair: $repaired"
 }
 run_test 15a "LFSCK can repair unmatched MDT-object/OST-object pairs (1)"
@@ -1366,36 +1785,93 @@ test_15b() {
 	echo "#####"
 
 	check_mount_and_prep
-	$LFS setstripe -c 1 -i 0 $DIR/$tdir
-	dd if=/dev/zero of=$DIR/$tdir/guard bs=1M count=1
+	mkdir -p $DIR/$tdir/0
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/0
+	dd if=/dev/zero of=$DIR/$tdir/0/guard bs=1M count=1
 	cancel_lru_locks osc
 
 	echo "Inject failure stub to make the OST-object to back point to"
 	echo "other MDT-object"
 
+	local stripes=1
+	[ $OSTCOUNT -ge 2 ] && stripes=2
+
 	#define OBD_FAIL_LFSCK_UNMATCHED_PAIR2	0x1612
-	do_facet ost1 $LCTL set_param fail_loc=0x1612
-	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=1
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0x1612
+	dd if=/dev/zero of=$DIR/$tdir/0/f0 bs=1M count=1
+	$LFS setstripe -E 1M -S 256K -c $stripes -E 2M -S 512K -c 1 \
+		$DIR/$tdir/f1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f1"
+	dd if=/dev/zero of=$DIR/$tdir/f1 bs=1M count=2
 	cancel_lru_locks osc
-	do_facet ost1 $LCTL set_param fail_loc=0
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0
 
 	echo "Trigger layout LFSCK to find out unmatched pairs and fix them"
 	$START_LAYOUT -r || error "(1) Fail to start LFSCK for layout!"
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(2) unexpected status"
 	}
 
 	local repaired=$($SHOW_LAYOUT |
 			 awk '/^repaired_unmatched_pair/ { print $2 }')
-	[ $repaired -eq 1 ] ||
+	[ $repaired -eq 4 ] ||
 		error "(3) Fail to repair unmatched pair: $repaired"
 }
 run_test 15b "LFSCK can repair unmatched MDT-object/OST-object pairs (2)"
 
+test_15c() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	[ $(lustre_version_code $SINGLEMDS) -ge $(version_code 2.7.55) ] &&
+		skip "Skip the test after 2.7.55 see LU-6437" && return
+
+	echo "#####"
+	echo "According to current metadata migration implementation,"
+	echo "before the old MDT-object is removed, both the new MDT-object"
+	echo "and old MDT-object will reference the same LOV layout. Then if"
+	echo "the layout LFSCK finds the new MDT-object by race, it will"
+	echo "regard related OST-object(s) as multiple referenced case, and"
+	echo "will try to create new OST-object(s) for the new MDT-object."
+	echo "To avoid such trouble, the layout LFSCK needs to lock the old"
+	echo "MDT-object before confirm the multiple referenced case."
+	echo "#####"
+
+	check_mount_and_prep
+	$LFS mkdir -i 1 $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
+	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=1
+	cancel_lru_locks osc
+
+	echo "Inject failure stub on MDT1 to delay the migration"
+
+	#define OBD_FAIL_MIGRATE_DELAY			0x1803
+	do_facet mds2 $LCTL set_param fail_val=5 fail_loc=0x1803
+	echo "Migrate $DIR/$tdir/a1 from MDT1 to MDT0 with delay"
+	$LFS migrate -m 0 $DIR/$tdir/a1 &
+
+	sleep 1
+	echo "Trigger layout LFSCK to race with the migration"
+	$START_LAYOUT -A -r || error "(1) Fail to start layout LFSCK!"
+
+	wait_all_targets_blocked layout completed 2
+
+	do_facet mds2 $LCTL set_param fail_loc=0 fail_val=0
+	local repaired=$($SHOW_LAYOUT |
+			 awk '/^repaired_unmatched_pair/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(3) Fail to repair unmatched pair: $repaired"
+
+	repaired=$($SHOW_LAYOUT |
+		   awk '/^repaired_multiple_referenced/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(4) Unexpectedly repaird multiple references: $repaired"
+}
+run_test 15c "LFSCK can repair unmatched MDT-object/OST-object pairs (3)"
+
 test_16() {
 	echo "#####"
 	echo "If the OST-object's owner information does not match the owner"
@@ -1408,6 +1884,11 @@ test_16() {
 	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=1
 	cancel_lru_locks osc
 
+	# created but no setattr or write to the file.
+	mkdir $DIR/$tdir/d1
+	chown $RUNAS_ID:$RUNAS_GID $DIR/$tdir/d1
+	$RUNAS createmany -o $DIR/$tdir/d1/o 100 || error "create failed"
+
 	echo "Inject failure stub to skip OST-object owner changing"
 	#define OBD_FAIL_LFSCK_BAD_OWNER	0x1613
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1613
@@ -1421,7 +1902,7 @@ test_16() {
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(2) unexpected status"
 	}
@@ -1449,21 +1930,30 @@ test_17() {
 
 	#define OBD_FAIL_LFSCK_MULTIPLE_REF	0x1614
 	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0x1614
-
 	dd if=/dev/zero of=$DIR/$tdir/guard bs=1M count=1
+	cancel_lru_locks mdc
 	cancel_lru_locks osc
 
 	createmany -o $DIR/$tdir/f 1
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
 
-	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
-
+	$LFS setstripe -E 2M -S 256K -o 0 -E 4M -S 512K -o 0 \
+		$DIR/$tdir/f1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f1"
 	cancel_lru_locks mdc
 	cancel_lru_locks osc
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
 
 	echo "$DIR/$tdir/f0 and $DIR/$tdir/guard use the same OST-objects"
+	echo "$DIR/$tdir/f1 and $DIR/$tdir/guard use the same OST-objects"
 	local size=$(ls -l $DIR/$tdir/f0 | awk '{ print $5 }')
 	[ $size -eq 1048576 ] ||
-		error "(1) f0 (wrong) size should be 1048576, but got $size"
+		error "(1.1) f0 (wrong) size should be 1048576, but got $size"
+
+	size=$(ls -l $DIR/$tdir/f1 | awk '{ print $5 }')
+	[ $size -eq 1048576 ] ||
+		error "(1.2) f1 (wrong) size should be 1048576, but got $size"
 
 	echo "Trigger layout LFSCK to find out multiple refenced MDT-objects"
 	echo "and fix them"
@@ -1472,14 +1962,14 @@ test_17() {
 
 	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
 		mdd.${MDT_DEV}.lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "completed" 6 || {
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
 		$SHOW_LAYOUT
 		error "(3) unexpected status"
 	}
 
 	local repaired=$($SHOW_LAYOUT |
 			 awk '/^repaired_multiple_referenced/ { print $2 }')
-	[ $repaired -eq 1 ] ||
+	[ $repaired -eq 2 ] ||
 		error "(4) Fail to repair multiple references: $repaired"
 
 	echo "$DIR/$tdir/f0 and $DIR/$tdir/guard should use diff OST-objects"
@@ -1488,34 +1978,53 @@ test_17() {
 	size=$(ls -l $DIR/$tdir/guard | awk '{ print $5 }')
 	[ $size -eq 1048576 ] ||
 		error "(6) guard size should be 1048576, but got $size"
+
+	echo "$DIR/$tdir/f1 and $DIR/$tdir/guard should use diff OST-objects"
+	dd if=/dev/zero of=$DIR/$tdir/f1 bs=1M count=2 ||
+		error "(7) Fail to write f1."
+	size=$(ls -l $DIR/$tdir/guard | awk '{ print $5 }')
+	[ $size -eq 1048576 ] ||
+		error "(8) guard size should be 1048576, but got $size"
 }
 run_test 17 "LFSCK can repair multiple references"
 
+$LCTL set_param debug=+cache > /dev/null
+
 test_18a() {
 	echo "#####"
 	echo "The target MDT-object is there, but related stripe information"
-	echo "is lost or partly lost. The LFSCK should regenerate the missed"
+	echo "is lost or partly lost. The LFSCK should regenerate the missing"
 	echo "layout EA entries."
 	echo "#####"
 
 	check_mount_and_prep
 	$LFS mkdir -i 0 $DIR/$tdir/a1
-	$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
 	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=2
 
-	local saved_size=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
+	local saved_size1=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
 
 	$LFS path2fid $DIR/$tdir/a1/f1
 	$LFS getstripe $DIR/$tdir/a1/f1
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		$LFS mkdir -i 1 $DIR/$tdir/a2
-		$LFS setstripe -c 2 -i 1 -s 1M $DIR/$tdir/a2
+		$LFS setstripe -c 2 -i 1 -S 1M $DIR/$tdir/a2
 		dd if=/dev/zero of=$DIR/$tdir/a2/f2 bs=1M count=2
 		$LFS path2fid $DIR/$tdir/a2/f2
 		$LFS getstripe $DIR/$tdir/a2/f2
 	fi
 
+	$LFS setstripe -E 1M -S 1M -o 0 -E -1 -S 1M $DIR/$tdir/f3 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f3"
+
+	dd if=/dev/zero of=$DIR/$tdir/f3 bs=1M count=2
+
+	local saved_size2=$(ls -il $DIR/$tdir/f3 | awk '{ print $6 }')
+
+	$LFS path2fid $DIR/$tdir/f3
+	$LFS getstripe $DIR/$tdir/f3
+
 	cancel_lru_locks osc
 
 	echo "Inject failure, to make the MDT-object lost its layout EA"
@@ -1528,6 +2037,8 @@ test_18a() {
 		chown 1.1 $DIR/$tdir/a2/f2
 	fi
 
+	chown 1.1 $DIR/$tdir/f3
+
 	sync
 	sleep 2
 
@@ -1541,15 +2052,19 @@ test_18a() {
 
 	echo "The file size should be incorrect since layout EA is lost"
 	local cur_size=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
-	[ "$cur_size" != "$saved_size" ] ||
+	[ "$cur_size" != "$saved_size1" ] ||
 		error "(1) Expect incorrect file1 size"
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		cur_size=$(ls -il $DIR/$tdir/a2/f2 | awk '{ print $6 }')
-		[ "$cur_size" != "$saved_size" ] ||
+		[ "$cur_size" != "$saved_size1" ] ||
 			error "(2) Expect incorrect file2 size"
 	fi
 
+	cur_size=$(ls -il $DIR/$tdir/f3 | awk '{ print $6 }')
+	[ "$cur_size" != "$saved_size2" ] ||
+		error "(1.2) Expect incorrect file3 size"
+
 	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
 	$START_LAYOUT -r -o || error "(3) Fail to start LFSCK for layout!"
 
@@ -1559,7 +2074,7 @@ test_18a() {
 		# time to guarantee the status sync up.
 		wait_update_facet mds${k} "$LCTL get_param -n \
 			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
 			error "(4) MDS${k} is not the expected 'completed'"
 	done
 
@@ -1574,8 +2089,8 @@ test_18a() {
 	local repaired=$(do_facet mds1 $LCTL get_param -n \
 			 mdd.$(facet_svc mds1).lfsck_layout |
 			 awk '/^repaired_orphan/ { print $2 }')
-	[ $repaired -eq 1 ] ||
-	error "(6.1) Expect 1 fixed on mds1, but got: $repaired"
+	[ $repaired -eq 3 ] ||
+	error "(6.1) Expect 3 fixed on mds1, but got: $repaired"
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		repaired=$(do_facet mds2 $LCTL get_param -n \
@@ -1593,20 +2108,29 @@ test_18a() {
 		$LFS getstripe $DIR/$tdir/a2/f2
 	fi
 
+	$LFS path2fid $DIR/$tdir/f3
+	$LFS getstripe $DIR/$tdir/f3
+
 	echo "The file size should be correct after layout LFSCK scanning"
 	cur_size=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
-	[ "$cur_size" == "$saved_size" ] ||
-		error "(7) Expect file1 size $saved_size, but got $cur_size"
+	[ "$cur_size" == "$saved_size1" ] ||
+		error "(7) Expect file1 size $saved_size1, but got $cur_size"
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		cur_size=$(ls -il $DIR/$tdir/a2/f2 | awk '{ print $6 }')
-		[ "$cur_size" == "$saved_size" ] ||
-		error "(8) Expect file2 size $saved_size, but got $cur_size"
+		[ "$cur_size" == "$saved_size1" ] ||
+		error "(8) Expect file2 size $saved_size1, but got $cur_size"
 	fi
+
+	cur_size=$(ls -il $DIR/$tdir/f3 | awk '{ print $6 }')
+	[ "$cur_size" == "$saved_size2" ] ||
+		error "(9) Expect file1 size $saved_size2, but got $cur_size"
 }
 run_test 18a "Find out orphan OST-object and repair it (1)"
 
 test_18b() {
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
 	echo "#####"
 	echo "The target MDT-object is lost. The LFSCK should re-create the"
 	echo "MDT-object under .lustre/lost+found/MDTxxxx. The admin should"
@@ -1615,22 +2139,32 @@ test_18b() {
 
 	check_mount_and_prep
 	$LFS mkdir -i 0 $DIR/$tdir/a1
-	$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
 	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=2
-	local saved_size=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
+	local saved_size1=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
 	local fid1=$($LFS path2fid $DIR/$tdir/a1/f1)
 	echo ${fid1}
 	$LFS getstripe $DIR/$tdir/a1/f1
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		$LFS mkdir -i 1 $DIR/$tdir/a2
-		$LFS setstripe -c 2 -i 1 -s 1M $DIR/$tdir/a2
+		$LFS setstripe -c 2 -i 1 -S 1M $DIR/$tdir/a2
 		dd if=/dev/zero of=$DIR/$tdir/a2/f2 bs=1M count=2
 		fid2=$($LFS path2fid $DIR/$tdir/a2/f2)
 		echo ${fid2}
 		$LFS getstripe $DIR/$tdir/a2/f2
 	fi
 
+	$LFS setstripe -E 1M -S 1M -o 0 -E -1 -S 1M $DIR/$tdir/f3 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f3"
+
+	dd if=/dev/zero of=$DIR/$tdir/f3 bs=1M count=2
+
+	local saved_size2=$(ls -il $DIR/$tdir/f3 | awk '{ print $6 }')
+	local fid3=$($LFS path2fid $DIR/$tdir/f3)
+	echo ${fid3}
+	$LFS getstripe $DIR/$tdir/f3
+
 	cancel_lru_locks osc
 
 	echo "Inject failure, to simulate the case of missing the MDT-object"
@@ -1643,6 +2177,8 @@ test_18b() {
 		rm -f $DIR/$tdir/a2/f2
 	fi
 
+	rm -f $DIR/$tdir/f3
+
 	sync
 	sleep 2
 
@@ -1663,7 +2199,7 @@ test_18b() {
 		# time to guarantee the status sync up.
 		wait_update_facet mds${k} "$LCTL get_param -n \
 			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
 			error "(2) MDS${k} is not the expected 'completed'"
 	done
 
@@ -1678,8 +2214,8 @@ test_18b() {
 	local repaired=$(do_facet mds1 $LCTL get_param -n \
 			 mdd.$(facet_svc mds1).lfsck_layout |
 			 awk '/^repaired_orphan/ { print $2 }')
-	[ $repaired -eq 1 ] ||
-	error "(4.1) Expect 1 fixed on mds1, but got: $repaired"
+	[ $repaired -eq 3 ] ||
+	error "(4.1) Expect 3 fixed on mds1, but got: $repaired"
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		repaired=$(do_facet mds2 $LCTL get_param -n \
@@ -1698,6 +2234,9 @@ test_18b() {
 		mv $name $DIR/$tdir/a2/f2 || error "(6) Fail to move $name"
 	fi
 
+	mv $MOUNT/.lustre/lost+found/MDT0000/${fid3}-R-0 $DIR/$tdir/f3 ||
+	error "(5) Fail to move $MOUNT/.lustre/lost+found/MDT0000/${fid3}-R-0"
+
 	$LFS path2fid $DIR/$tdir/a1/f1
 	$LFS getstripe $DIR/$tdir/a1/f1
 
@@ -1706,20 +2245,29 @@ test_18b() {
 		$LFS getstripe $DIR/$tdir/a2/f2
 	fi
 
+	$LFS path2fid $DIR/$tdir/f3
+	$LFS getstripe $DIR/$tdir/f3
+
 	echo "The file size should be correct after layout LFSCK scanning"
 	local cur_size=$(ls -il $DIR/$tdir/a1/f1 | awk '{ print $6 }')
-	[ "$cur_size" == "$saved_size" ] ||
-		error "(7) Expect file1 size $saved_size, but got $cur_size"
+	[ "$cur_size" == "$saved_size1" ] ||
+		error "(7) Expect file1 size $saved_size1, but got $cur_size"
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		cur_size=$(ls -il $DIR/$tdir/a2/f2 | awk '{ print $6 }')
-		[ "$cur_size" == "$saved_size" ] ||
-		error "(8) Expect file2 size $saved_size, but got $cur_size"
+		[ "$cur_size" == "$saved_size1" ] ||
+		error "(8) Expect file2 size $saved_size1, but got $cur_size"
 	fi
+
+	cur_size=$(ls -il $DIR/$tdir/f3 | awk '{ print $6 }')
+	[ "$cur_size" == "$saved_size2" ] ||
+		error "(9) Expect file1 size $saved_size2, but got $cur_size"
 }
 run_test 18b "Find out orphan OST-object and repair it (2)"
 
 test_18c() {
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
 	echo "#####"
 	echo "The target MDT-object is lost, and the OST-object FID is missing."
 	echo "The LFSCK should re-create the MDT-object with new FID under the "
@@ -1728,23 +2276,30 @@ test_18c() {
 
 	check_mount_and_prep
 	$LFS mkdir -i 0 $DIR/$tdir/a1
-	$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
 
 	echo "Inject failure, to simulate the case of missing parent FID"
 	#define OBD_FAIL_LFSCK_NOPFID		0x1617
-	do_facet ost1 $LCTL set_param fail_loc=0x1617
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0x1617
 
 	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=2
 	$LFS getstripe $DIR/$tdir/a1/f1
 
 	if [ $MDSCOUNT -ge 2 ]; then
 		$LFS mkdir -i 1 $DIR/$tdir/a2
-		$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a2
+		$LFS setstripe -c 1 -i 0 $DIR/$tdir/a2
 		dd if=/dev/zero of=$DIR/$tdir/a2/f2 bs=1M count=2
 		$LFS getstripe $DIR/$tdir/a2/f2
 	fi
 
+	$LFS setstripe -E 1M -S 1M -o 0 -E -1 -S 1M $DIR/$tdir/f3 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f3"
+
+	dd if=/dev/zero of=$DIR/$tdir/f3 bs=1M count=2
+	$LFS getstripe $DIR/$tdir/f3
+
 	cancel_lru_locks osc
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0
 
 	echo "Inject failure, to simulate the case of missing the MDT-object"
 	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
@@ -1756,6 +2311,8 @@ test_18c() {
 		rm -f $DIR/$tdir/a2/f2
 	fi
 
+	rm -f $DIR/$tdir/f3
+
 	sync
 	sleep 2
 
@@ -1776,7 +2333,7 @@ test_18c() {
 		# time to guarantee the status sync up.
 		wait_update_facet mds${k} "$LCTL get_param -n \
 			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
 			error "(2) MDS${k} is not the expected 'completed'"
 	done
 
@@ -1789,9 +2346,9 @@ test_18c() {
 	done
 
 	if [ $MDSCOUNT -ge 2 ]; then
-		expected=2
+		expected=4
 	else
-		expected=1
+		expected=3
 	fi
 
 	local repaired=$(do_facet mds1 $LCTL get_param -n \
@@ -1808,47 +2365,72 @@ test_18c() {
 			error "(5) Expect 0 fixed on mds2, but got: $repaired"
 	fi
 
+	ls -ail $MOUNT/.lustre/lost+found/
+
 	echo "There should NOT be some stub under .lustre/lost+found/MDT0001/"
-	ls -ail $MOUNT/.lustre/lost+found/MDT0001/*-N-0 &&
-		error "(6) .lustre/lost+found/MDT0001/ should be empty"
+	if [ -d $MOUNT/.lustre/lost+found/MDT0001 ]; then
+		cname=$(find $MOUNT/.lustre/lost+found/MDT0001/ -name *-N-*)
+		[ -z "$cname" ] ||
+			error "(6) .lustre/lost+found/MDT0001/ should be empty"
+	fi
 
 	echo "There should be some stub under .lustre/lost+found/MDT0000/"
-	ls -ail $MOUNT/.lustre/lost+found/MDT0000/*-N-0 ||
-		error "(7) .lustre/lost+found/MDT0000/ should not be empty"
+	[ -d $MOUNT/.lustre/lost+found/MDT0000 ] ||
+		error "(7) $MOUNT/.lustre/lost+found/MDT0000/ should be there"
+
+	cname=$(find $MOUNT/.lustre/lost+found/MDT0000/ -name *-N-*)
+	[ ! -z "$cname" ] ||
+		error "(8) .lustre/lost+found/MDT0000/ should not be empty"
 }
 run_test 18c "Find out orphan OST-object and repair it (3)"
 
 test_18d() {
 	echo "#####"
-	echo "The target MDT-object layout EA slot is occpuied by some new"
-	echo "created OST-object when repair dangling reference case. Such"
-	echo "conflict OST-object has never been modified. Then when found"
-	echo "the orphan OST-object, LFSCK will replace it with the orphan"
-	echo "OST-object."
+	echo "The target MDT-object layout EA is corrupted, but the right"
+	echo "OST-object is still alive as orphan. The layout LFSCK will"
+	echo "not create new OST-object to occupy such slot."
 	echo "#####"
 
 	check_mount_and_prep
 	mkdir $DIR/$tdir/a1
-	$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
 	echo "guard" > $DIR/$tdir/a1/f1
 	echo "foo" > $DIR/$tdir/a1/f2
-	local saved_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
+
+	echo "guard" > $DIR/$tdir/a1/f3
+	$LFS setstripe -E 1M -S 1M -o 0 -E -1 -S 1M $DIR/$tdir/a1/f4 ||
+		error "(0) Fail to create PFL $DIR/$tdir/a1/f4"
+	echo "foo" > $DIR/$tdir/a1/f4
+
+	local saved_size1=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
+	local saved_size2=$(ls -il $DIR/$tdir/a1/f4 | awk '{ print $6 }')
 	$LFS path2fid $DIR/$tdir/a1/f1
 	$LFS getstripe $DIR/$tdir/a1/f1
 	$LFS path2fid $DIR/$tdir/a1/f2
 	$LFS getstripe $DIR/$tdir/a1/f2
+	$LFS path2fid $DIR/$tdir/a1/f3
+	$LFS getstripe $DIR/$tdir/a1/f3
+	$LFS path2fid $DIR/$tdir/a1/f4
+	$LFS getstripe $DIR/$tdir/a1/f4
 	cancel_lru_locks osc
 
 	echo "Inject failure to make $DIR/$tdir/a1/f1 and $DIR/$tdir/a1/f2"
 	echo "to reference the same OST-object (which is f1's OST-obejct)."
 	echo "Then drop $DIR/$tdir/a1/f1 and its OST-object, so f2 becomes"
 	echo "dangling reference case, but f2's old OST-object is there."
+
+	echo "The failure also makes $DIR/$tdir/a1/f3 and $DIR/$tdir/a1/f4"
+	echo "to reference the same OST-object (which is f3's OST-obejct)."
+	echo "Then drop $DIR/$tdir/a1/f3 and its OST-object, so f4 becomes"
+	echo "dangling reference case, but f4's old OST-object is there."
 	echo
 
 	#define OBD_FAIL_LFSCK_CHANGE_STRIPE	0x1618
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1618
 	chown 1.1 $DIR/$tdir/a1/f2
+	chown 1.1 $DIR/$tdir/a1/f4
 	rm -f $DIR/$tdir/a1/f1
+	rm -f $DIR/$tdir/a1/f3
 	sync
 	sleep 2
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
@@ -1858,23 +2440,8 @@ test_18d() {
 	echo "setupall"
 	setupall > /dev/null
 
-	echo "The file size should be incorrect since dangling referenced"
-	local cur_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
-	[ "$cur_size" != "$saved_size" ] ||
-		error "(1) Expect incorrect file2 size"
-
-	#define OBD_FAIL_LFSCK_DELAY3		0x1602
-	do_facet $SINGLEMDS $LCTL set_param fail_val=5 fail_loc=0x1602
-
 	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
-	$START_LAYOUT -r -o -c || error "(2) Fail to start LFSCK for layout!"
-
-	wait_update_facet mds1 "$LCTL get_param -n \
-		mdd.$(facet_svc mds1).lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 6 ||
-		error "(3.0) MDS1 is not the expected 'scanning-phase2'"
-
-	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0
+	$START_LAYOUT -r -o -c -d || error "(2) Fail to start LFSCK for layout!"
 
 	for k in $(seq $MDSCOUNT); do
 		# The LFSCK status query internal is 30 seconds. For the case
@@ -1882,7 +2449,7 @@ test_18d() {
 		# time to guarantee the status sync up.
 		wait_update_facet mds${k} "$LCTL get_param -n \
 			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
 			error "(3) MDS${k} is not the expected 'completed'"
 	done
 
@@ -1897,22 +2464,37 @@ test_18d() {
 	local repaired=$(do_facet $SINGLEMDS $LCTL get_param -n \
 			 mdd.$(facet_svc $SINGLEMDS).lfsck_layout |
 			 awk '/^repaired_orphan/ { print $2 }')
-	[ $repaired -eq 1 ] ||
-		error "(5) Expect 1 orphan has been fixed, but got: $repaired"
+	[ $repaired -eq 2 ] ||
+		error "(5) Expect 2 orphans have been fixed, but got: $repaired"
+
+	repaired=$(do_facet $SINGLEMDS $LCTL get_param -n \
+		   mdd.$(facet_svc $SINGLEMDS).lfsck_layout |
+		   awk '/^repaired_dangling/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(6) Expect 0 dangling has been fixed, but got: $repaired"
 
 	echo "The file size should be correct after layout LFSCK scanning"
-	cur_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
-	[ "$cur_size" == "$saved_size" ] ||
-		error "(6) Expect file2 size $saved_size, but got $cur_size"
+	local cur_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
+	[ "$cur_size" == "$saved_size1" ] ||
+		error "(7) Expect file2 size $saved_size1, but got $cur_size"
+
+	cur_size=$(ls -il $DIR/$tdir/a1/f4 | awk '{ print $6 }')
+	[ "$cur_size" == "$saved_size2" ] ||
+		error "(8) Expect file4 size $saved_size2, but got $cur_size"
 
 	echo "The LFSCK should find back the original data."
 	cat $DIR/$tdir/a1/f2
 	$LFS path2fid $DIR/$tdir/a1/f2
 	$LFS getstripe $DIR/$tdir/a1/f2
+	cat $DIR/$tdir/a1/f4
+	$LFS path2fid $DIR/$tdir/a1/f4
+	$LFS getstripe $DIR/$tdir/a1/f4
 }
 run_test 18d "Find out orphan OST-object and repair it (4)"
 
 test_18e() {
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
 	echo "#####"
 	echo "The target MDT-object layout EA slot is occpuied by some new"
 	echo "created OST-object when repair dangling reference case. Such"
@@ -1923,26 +2505,45 @@ test_18e() {
 
 	check_mount_and_prep
 	mkdir $DIR/$tdir/a1
-	$LFS setstripe -c 1 -i 0 -s 1M $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
 	echo "guard" > $DIR/$tdir/a1/f1
 	echo "foo" > $DIR/$tdir/a1/f2
-	local saved_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
+
+	echo "guard" > $DIR/$tdir/a1/f3
+	$LFS setstripe -E 1M -S 1M -o 0 -E -1 -S 1M $DIR/$tdir/a1/f4 ||
+		error "(0) Fail to create PFL $DIR/$tdir/a1/f4"
+	echo "foo" > $DIR/$tdir/a1/f4
+
+	local saved_size1=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
+	local saved_size2=$(ls -il $DIR/$tdir/a1/f4 | awk '{ print $6 }')
+
 	$LFS path2fid $DIR/$tdir/a1/f1
 	$LFS getstripe $DIR/$tdir/a1/f1
 	$LFS path2fid $DIR/$tdir/a1/f2
 	$LFS getstripe $DIR/$tdir/a1/f2
+	$LFS path2fid $DIR/$tdir/a1/f3
+	$LFS getstripe $DIR/$tdir/a1/f3
+	$LFS path2fid $DIR/$tdir/a1/f4
+	$LFS getstripe $DIR/$tdir/a1/f4
 	cancel_lru_locks osc
 
 	echo "Inject failure to make $DIR/$tdir/a1/f1 and $DIR/$tdir/a1/f2"
 	echo "to reference the same OST-object (which is f1's OST-obejct)."
 	echo "Then drop $DIR/$tdir/a1/f1 and its OST-object, so f2 becomes"
 	echo "dangling reference case, but f2's old OST-object is there."
+
+	echo "Also the failure makes $DIR/$tdir/a1/f3 and $DIR/$tdir/a1/f4"
+	echo "to reference the same OST-object (which is f3's OST-obejct)."
+	echo "Then drop $DIR/$tdir/a1/f3 and its OST-object, so f4 becomes"
+	echo "dangling reference case, but f4's old OST-object is there."
 	echo
 
 	#define OBD_FAIL_LFSCK_CHANGE_STRIPE	0x1618
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1618
 	chown 1.1 $DIR/$tdir/a1/f2
+	chown 1.1 $DIR/$tdir/a1/f4
 	rm -f $DIR/$tdir/a1/f1
+	rm -f $DIR/$tdir/a1/f3
 	sync
 	sleep 2
 	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
@@ -1952,28 +2553,26 @@ test_18e() {
 	echo "setupall"
 	setupall > /dev/null
 
-	echo "The file size should be incorrect since dangling referenced"
-	local cur_size=$(ls -il $DIR/$tdir/a1/f2 | awk '{ print $6 }')
-	[ "$cur_size" != "$saved_size" ] ||
-		error "(1) Expect incorrect file2 size"
-
 	#define OBD_FAIL_LFSCK_DELAY3		0x1602
 	do_facet $SINGLEMDS $LCTL set_param fail_val=10 fail_loc=0x1602
 
+	start_full_debug_logging
+
 	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
 	$START_LAYOUT -r -o -c || error "(2) Fail to start LFSCK for layout!"
 
 	wait_update_facet mds1 "$LCTL get_param -n \
 		mdd.$(facet_svc mds1).lfsck_layout |
-		awk '/^status/ { print \\\$2 }'" "scanning-phase2" 6 ||
+		awk '/^status/ { print \\\$2 }'" "scanning-phase2" $LTIME ||
 		error "(3) MDS1 is not the expected 'scanning-phase2'"
 
 	# to guarantee all updates are synced.
 	sync
 	sleep 2
 
-	echo "Write new data to f2 to modify the new created OST-object."
-	echo "dummy" >> $DIR/$tdir/a1/f2
+	echo "Write new data to f2/f4 to modify the new created OST-object."
+	echo "dummy" >> $DIR/$tdir/a1/f2 || error "write a1/f2 failed"
+	echo "dummy" >> $DIR/$tdir/a1/f4 || error "write a1/f4 failed"
 
 	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0
 
@@ -1983,7 +2582,7 @@ test_18e() {
 		# time to guarantee the status sync up.
 		wait_update_facet mds${k} "$LCTL get_param -n \
 			mdd.$(facet_svc mds${k}).lfsck_layout |
-			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
 			error "(4) MDS${k} is not the expected 'completed'"
 	done
 
@@ -1995,112 +2594,434 @@ test_18e() {
 		error "(5) OST${k} Expect 'completed', but got '$cur_status'"
 	done
 
+	stop_full_debug_logging
+
 	local repaired=$(do_facet $SINGLEMDS $LCTL get_param -n \
 			 mdd.$(facet_svc $SINGLEMDS).lfsck_layout |
 			 awk '/^repaired_orphan/ { print $2 }')
-	[ $repaired -eq 1 ] ||
-		error "(6) Expect 1 orphan has been fixed, but got: $repaired"
+	[ $repaired -eq 2 ] ||
+		error "(6) Expect 2 orphans have been fixed, but got: $repaired"
 
 	echo "There should be stub file under .lustre/lost+found/MDT0000/"
-	local cname=$(ls $MOUNT/.lustre/lost+found/MDT0000/*-C-0)
-	[ ! -z $name ] ||
-		error "(7) .lustre/lost+found/MDT0000/ should not be empty"
+	[ -d $MOUNT/.lustre/lost+found/MDT0000 ] ||
+		error "(7) $MOUNT/.lustre/lost+found/MDT0000/ should be there"
 
-	echo "The stub file should keep the original f2 data"
+	local count=$(ls -l $MOUNT/.lustre/lost+found/MDT0000/*-C-* | wc -l)
+	if [ $count -ne 2 ]; then
+		ls -l $MOUNT/.lustre/lost+found/MDT0000/*-C-*
+		error "(8) Expect 2 stubs under lost+found, but got $count"
+	fi
+
+	echo "The stub file should keep the original f2 or f4 data"
+	cname=$(find $MOUNT/.lustre/lost+found/MDT0000/ -name *-C-* | head -n 1)
+	local cur_size=$(ls -il $cname | awk '{ print $6 }')
+	[ "$cur_size" != "$saved_size1" -a "$cur_size" != "$saved_size2" ] &&
+		error "(9) Got unexpected $cur_size"
+
+	cat $cname
+	$LFS path2fid $cname
+	$LFS getstripe $cname
+
+	cname=$(find $MOUNT/.lustre/lost+found/MDT0000/ -name *-C-* | tail -n 1)
 	cur_size=$(ls -il $cname | awk '{ print $6 }')
-	[ "$cur_size" == "$saved_size" ] ||
-		error "(8) Expect file2 size $saved_size, but got $cur_size"
+	[ "$cur_size" != "$saved_size1" -a "$cur_size" != "$saved_size2" ] &&
+		error "(10) Got unexpected $cur_size"
 
 	cat $cname
 	$LFS path2fid $cname
 	$LFS getstripe $cname
 
-	echo "The f2 should contains new data."
+	echo "The f2/f4 should contains new data."
 	cat $DIR/$tdir/a1/f2
 	$LFS path2fid $DIR/$tdir/a1/f2
 	$LFS getstripe $DIR/$tdir/a1/f2
+	cat $DIR/$tdir/a1/f4
+	$LFS path2fid $DIR/$tdir/a1/f4
+	$LFS getstripe $DIR/$tdir/a1/f4
 }
 run_test 18e "Find out orphan OST-object and repair it (5)"
 
-test_19a() {
+test_18f() {
+	[ $OSTCOUNT -lt 2 ] && skip "needs >= 2 OSTs" && return
+
+	echo "#####"
+	echo "The target MDT-object is lost. The LFSCK should re-create the"
+	echo "MDT-object under .lustre/lost+found/MDTxxxx. If some OST fail"
+	echo "to verify some OST-object(s) during the first stage-scanning,"
+	echo "the LFSCK should skip orphan OST-objects for such OST. Others"
+	echo "should not be affected."
+	echo "#####"
+
 	check_mount_and_prep
-	$LFS setstripe -c 1 -i 0 $DIR/$tdir
+	$LFS mkdir -i 0 $DIR/$tdir/a1
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir/a1
+	dd if=/dev/zero of=$DIR/$tdir/a1/guard bs=1M count=2
+	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=2
+	$LFS mkdir -i 0 $DIR/$tdir/a2
+	$LFS setstripe -c 2 -i 0 -S 1M $DIR/$tdir/a2
+	dd if=/dev/zero of=$DIR/$tdir/a2/f2 bs=1M count=2
+	$LFS getstripe $DIR/$tdir/a1/f1
+	$LFS getstripe $DIR/$tdir/a2/f2
+
+	if [ $MDSCOUNT -ge 2 ]; then
+		$LFS mkdir -i 1 $DIR/$tdir/a3
+		$LFS setstripe -c 1 -i 0 $DIR/$tdir/a3
+		dd if=/dev/zero of=$DIR/$tdir/a3/guard bs=1M count=2
+		dd if=/dev/zero of=$DIR/$tdir/a3/f3 bs=1M count=2
+		$LFS mkdir -i 1 $DIR/$tdir/a4
+		$LFS setstripe -c 2 -i 0 -S 1M $DIR/$tdir/a4
+		dd if=/dev/zero of=$DIR/$tdir/a4/f4 bs=1M count=2
+		$LFS getstripe $DIR/$tdir/a3/f3
+		$LFS getstripe $DIR/$tdir/a4/f4
+	fi
 
-	echo "foo" > $DIR/$tdir/a0
-	echo "guard" > $DIR/$tdir/a1
 	cancel_lru_locks osc
 
-	echo "Inject failure, then client will offer wrong parent FID when read"
-	do_facet ost1 $LCTL set_param -n \
-		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 1
-	#define OBD_FAIL_LFSCK_INVALID_PFID	0x1619
-	$LCTL set_param fail_loc=0x1619
+	echo "Inject failure, to simulate the case of missing the MDT-object"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
+	do_facet mds1 $LCTL set_param fail_loc=0x1616
+	rm -f $DIR/$tdir/a1/f1
+	rm -f $DIR/$tdir/a2/f2
 
-	echo "Read RPC with wrong parent FID should be denied"
-	cat $DIR/$tdir/a0 && error "(3) Read should be denied!"
-	$LCTL set_param fail_loc=0
-}
-run_test 19a "OST-object inconsistency self detect"
+	if [ $MDSCOUNT -ge 2 ]; then
+		do_facet mds2 $LCTL set_param fail_loc=0x1616
+		rm -f $DIR/$tdir/a3/f3
+		rm -f $DIR/$tdir/a4/f4
+	fi
 
-test_19b() {
-	check_mount_and_prep
-	$LFS setstripe -c 1 -i 0 $DIR/$tdir
+	sync
+	sleep 2
 
-	echo "Inject failure stub to make the OST-object to back point to"
-	echo "non-exist MDT-object"
+	do_facet mds1 $LCTL set_param fail_loc=0
+	if [ $MDSCOUNT -ge 2 ]; then
+		do_facet mds2 $LCTL set_param fail_loc=0
+	fi
 
-	#define OBD_FAIL_LFSCK_UNMATCHED_PAIR1	0x1611
-	do_facet ost1 $LCTL set_param fail_loc=0x1611
-	echo "foo" > $DIR/$tdir/f0
+	cancel_lru_locks mdc
 	cancel_lru_locks osc
-	do_facet ost1 $LCTL set_param fail_loc=0
-
-	echo "Nothing should be fixed since self detect and repair is disabled"
-	local repaired=$(do_facet ost1 $LCTL get_param -n \
-			obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid |
-			awk '/^repaired/ { print $2 }')
-	[ $repaired -eq 0 ] ||
-		error "(1) Expected 0 repaired, but got $repaired"
 
-	echo "Read RPC with right parent FID should be accepted,"
-	echo "and cause parent FID on OST to be fixed"
+	echo "Inject failure, to simulate the OST0 fail to handle"
+	echo "MDT0 LFSCK request during the first-stage scanning."
+	#define OBD_FAIL_LFSCK_BAD_NETWORK	0x161c
+	do_facet mds1 $LCTL set_param fail_loc=0x161c fail_val=0
 
-	do_facet ost1 $LCTL set_param -n \
-		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 1
-	cat $DIR/$tdir/f0 || error "(2) Read should not be denied!"
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(1) Fail to start LFSCK for layout!"
 
-	repaired=$(do_facet ost1 $LCTL get_param -n \
-		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid |
-		awk '/^repaired/ { print $2 }')
-	[ $repaired -eq 1 ] ||
-		error "(3) Expected 1 repaired, but got $repaired"
-}
-run_test 19b "OST-object inconsistency self repair"
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "partial" $LTIME ||
+			error "(2) MDS${k} is not the expected 'partial'"
+	done
 
-test_20() {
-	[ $OSTCOUNT -lt 2 ] &&
-		skip "The test needs at least 2 OSTs" && return
+	wait_update_facet ost1 "$LCTL get_param -n \
+		obdfilter.$(facet_svc ost1).lfsck_layout |
+		awk '/^status/ { print \\\$2 }'" "partial" $LTIME || {
+		error "(3) OST1 is not the expected 'partial'"
+	}
 
-	echo "#####"
-	echo "The target MDT-object and some of its OST-object are lost."
-	echo "The LFSCK should find out the left OST-objects and re-create"
-	echo "the MDT-object under the direcotry .lustre/lost+found/MDTxxxx/"
-	echo "with the partial OST-objects (LOV EA hole)."
+	wait_update_facet ost2 "$LCTL get_param -n \
+		obdfilter.$(facet_svc ost2).lfsck_layout |
+		awk '/^status/ { print \\\$2 }'" "completed" $LTIME || {
+		error "(4) OST2 is not the expected 'completed'"
+	}
 
-	echo "New client can access the file with LOV EA hole via normal"
-	echo "system tools or commands without crash the system."
+	do_facet mds1 $LCTL set_param fail_loc=0 fail_val=0
 
-	echo "For old client, even though it cannot access the file with"
-	echo "LOV EA hole, it should not cause the system crash."
-	echo "#####"
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(5) Expect 1 fixed on mds{1}, but got: $repaired"
 
-	check_mount_and_prep
+	if [ $MDSCOUNT -ge 2 ]; then
+		repaired=$(do_facet mds2 $LCTL get_param -n \
+			 mdd.$(facet_svc mds2).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+		[ $repaired -eq 1 ] ||
+		error "(6) Expect 1 fixed on mds{2}, but got: $repaired"
+	fi
+
+	echo "Trigger layout LFSCK on all devices again to cleanup"
+	$START_LAYOUT -r -o || error "(7) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
+			error "(8) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		cur_status=$(do_facet ost${k} $LCTL get_param -n \
+			     obdfilter.$(facet_svc ost${k}).lfsck_layout |
+			     awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(9) OST${k} Expect 'completed', but got '$cur_status'"
+
+	done
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq 2 ] ||
+		error "(10) Expect 2 fixed on mds{1}, but got: $repaired"
+
+	if [ $MDSCOUNT -ge 2 ]; then
+		repaired=$(do_facet mds2 $LCTL get_param -n \
+			 mdd.$(facet_svc mds2).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+		[ $repaired -eq 2 ] ||
+		error "(11) Expect 2 fixed on mds{2}, but got: $repaired"
+	fi
+}
+run_test 18f "Skip the failed OST(s) when handle orphan OST-objects"
+
+test_18g() {
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The target MDT-object is lost, but related OI mapping is there"
+	echo "The LFSCK should recreate the lost MDT-object without affected"
+	echo "by the stale OI mapping."
+	echo "#####"
+
+	check_mount_and_prep
+	$LFS mkdir -i 0 $DIR/$tdir/a1
+	$LFS setstripe -c -1 -i 0 -S 1M $DIR/$tdir/a1
+	dd if=/dev/zero of=$DIR/$tdir/a1/f1 bs=1M count=$OSTCOUNT
+	local fid1=$($LFS path2fid $DIR/$tdir/a1/f1)
+	echo ${fid1}
+	$LFS getstripe $DIR/$tdir/a1/f1
+	cancel_lru_locks osc
+
+	echo "Inject failure to simulate lost MDT-object but keep OI mapping"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ2	0x162e
+	do_facet mds1 $LCTL set_param fail_loc=0x162e
+	rm -f $DIR/$tdir/a1/f1
+
+	do_facet mds1 $LCTL set_param fail_loc=0
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(1) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
+			error "(2) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		local cur_status=$(do_facet ost${k} $LCTL get_param -n \
+				obdfilter.$(facet_svc ost${k}).lfsck_layout |
+				awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(3) OST${k} Expect 'completed', but got '$cur_status'"
+	done
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq $OSTCOUNT ] ||
+		error "(4) Expect $OSTCOUNT fixed, but got: $repaired"
+
+	echo "Move the files from ./lustre/lost+found/MDTxxxx to namespace"
+	mv $MOUNT/.lustre/lost+found/MDT0000/${fid1}-R-0 $DIR/$tdir/a1/f1 ||
+	error "(5) Fail to move $MOUNT/.lustre/lost+found/MDT0000/${fid1}-R-0"
+
+	$LFS path2fid $DIR/$tdir/a1/f1
+	$LFS getstripe $DIR/$tdir/a1/f1
+}
+run_test 18g "Find out orphan OST-object and repair it (7)"
+
+test_18h() {
+	echo "#####"
+	echo "The PFL extent crashed. During the first cycle LFSCK scanning,"
+	echo "the layout LFSCK will keep the bad PFL file(s) there without"
+	echo "scanning its OST-object(s). Then in the second stage scanning,"
+	echo "the OST will return related OST-object(s) to the MDT as orphan."
+	echo "And then the LFSCK on the MDT can rebuild the PFL extent with"
+	echo "the 'orphan(s)' stripe information."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setstripe -E 2M -S 1M -c 1 -E -1 $DIR/$tdir/f0 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f0"
+
+	cat $LUSTRE/tests/test-framework.sh > $DIR/$tdir/f0 ||
+		error "(1.1) Fail to write $DIR/$tdir/f0"
+
+	dd if=$LUSTRE/tests/test-framework.sh of=$DIR/$tdir/f0 bs=1M seek=2 ||
+		error "(1.2) Fail to write $DIR/$tdir/f0"
+
+	cp $DIR/$tdir/f0 $DIR/$tdir/guard
+
+	echo "Inject failure stub to simulate bad PFL extent range"
+	#define OBD_FAIL_LFSCK_BAD_PFL_RANGE	0x162f
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x162f
+
+	chown 1.1 $DIR/$tdir/f0
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=1 &&
+		error "(2) Write to bad PFL file should fail"
+
+	echo "Trigger layout LFSCK to find out the bad lmm_oi and fix them"
+	$START_LAYOUT -r -o || error "(3) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
+			error "(4.1) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		cur_status=$(do_facet ost${k} $LCTL get_param -n \
+			     obdfilter.$(facet_svc ost${k}).lfsck_layout |
+			     awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(4.2) OST${k} Expect 'completed', but got '$cur_status'"
+
+	done
+
+	local repaired=$($SHOW_LAYOUT |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq 2 ] ||
+		error "(5) Fail to repair crashed PFL range: $repaired"
+
+	echo "Data in $DIR/$tdir/f0 should not be broken"
+	diff $DIR/$tdir/f0 $DIR/$tdir/guard ||
+		error "(6) Data in $DIR/$tdir/f0 is broken"
+
+	echo "Write should succeed after LFSCK repairing the bad PFL range"
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=1 ||
+		error "(7) Write should succeed after LFSCK"
+}
+run_test 18h "LFSCK can repair crashed PFL extent range"
+
+$LCTL set_param debug=-cache > /dev/null
+
+test_19a() {
+	check_mount_and_prep
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir
+
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 0
+
+	echo "foo1" > $DIR/$tdir/a0
+	$LFS setstripe -E 512K -S 512K -o 0 -E -1 -S 1M $DIR/$tdir/a1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/a1"
+	echo "foo2" > $DIR/$tdir/a1
+	echo "guard" > $DIR/$tdir/a2
+	cancel_lru_locks osc
+
+	echo "Inject failure, then client will offer wrong parent FID when read"
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 1
+
+	#define OBD_FAIL_LFSCK_INVALID_PFID	0x1619
+	$LCTL set_param fail_loc=0x1619
+
+	echo "Read RPC with wrong parent FID should be denied"
+	cat $DIR/$tdir/a0 && error "(3.1) Read a0 should be denied!"
+	cat $DIR/$tdir/a1 && error "(3.2) Read a1 should be denied!"
+	$LCTL set_param fail_loc=0
+}
+run_test 19a "OST-object inconsistency self detect"
+
+test_19b() {
+	check_mount_and_prep
+	$LFS setstripe -c 1 -i 0 $DIR/$tdir
+
+	echo "Inject failure stub to make the OST-object to back point to"
+	echo "non-exist MDT-object"
+
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 0
+
+	#define OBD_FAIL_LFSCK_UNMATCHED_PAIR1	0x1611
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0x1611
+	echo "foo1" > $DIR/$tdir/f0
+	$LFS setstripe -E 1M -S 1M -o 0 -E 4M -S 256K $DIR/$tdir/f1 ||
+		error "(0) Fail to create PFL $DIR/$tdir/f1"
+	echo "foo2" > $DIR/$tdir/f1
+	cancel_lru_locks osc
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param fail_loc=0
+
+	do_facet ost1 $LCTL set_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 0
+	echo "Nothing should be fixed since self detect and repair is disabled"
+	local repaired=$(do_facet ost1 $LCTL get_param -n \
+			obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid |
+			awk '/^repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(1) Expected 0 repaired, but got $repaired"
+
+	echo "Read RPC with right parent FID should be accepted,"
+	echo "and cause parent FID on OST to be fixed"
+
+	do_nodes $(comma_list $(osts_nodes)) $LCTL set_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid 1
+
+	cat $DIR/$tdir/f0 || error "(2.1) Read f0 should not be denied!"
+	cat $DIR/$tdir/f1 || error "(2.2) Read f1 should not be denied!"
+
+	repaired=$(do_facet ost1 $LCTL get_param -n \
+		obdfilter.${FSNAME}-OST0000.lfsck_verify_pfid |
+		awk '/^repaired/ { print $2 }')
+	[ $repaired -eq 2 ] ||
+		error "(3) Expected 1 repaired, but got $repaired"
+}
+run_test 19b "OST-object inconsistency self repair"
+
+PATTERN_WITH_HOLE="40000001"
+PATTERN_WITHOUT_HOLE="raid0"
+
+test_20a() {
+	[ $OSTCOUNT -lt 2 ] && skip "needs >= 2 OSTs" && return
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The target MDT-object and some of its OST-object are lost."
+	echo "The LFSCK should find out the left OST-objects and re-create"
+	echo "the MDT-object under the direcotry .lustre/lost+found/MDTxxxx/"
+	echo "with the partial OST-objects (LOV EA hole)."
+
+	echo "New client can access the file with LOV EA hole via normal"
+	echo "system tools or commands without crash the system."
+
+	echo "For old client, even though it cannot access the file with"
+	echo "LOV EA hole, it should not cause the system crash."
+	echo "#####"
+
+	check_mount_and_prep
 	$LFS mkdir -i 0 $DIR/$tdir/a1
 	if [ $OSTCOUNT -gt 2 ]; then
-		$LFS setstripe -c 3 -i 0 -s 1M $DIR/$tdir/a1
+		$LFS setstripe -c 3 -i 0 -S 1M $DIR/$tdir/a1
 		bcount=513
 	else
-		$LFS setstripe -c 2 -i 0 -s 1M $DIR/$tdir/a1
+		$LFS setstripe -c 2 -i 0 -S 1M $DIR/$tdir/a1
 		bcount=257
 	fi
 
@@ -2158,16 +3079,9 @@ test_20() {
 	sleep 2
 	do_facet mds1 $LCTL set_param fail_loc=0 fail_val=0
 
-	echo "Inject failure to slow down the LFSCK on OST0"
-	#define OBD_FAIL_LFSCK_DELAY5		0x161b
-	do_facet ost1 $LCTL set_param fail_loc=0x161b
-
 	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
 	$START_LAYOUT -r -o || error "(1) Fail to start LFSCK for layout!"
 
-	sleep 3
-	do_facet ost1 $LCTL set_param fail_loc=0
-
 	for k in $(seq $MDSCOUNT); do
 		# The LFSCK status query internal is 30 seconds. For the case
 		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
@@ -2209,8 +3123,8 @@ test_20() {
 
 	$LFS getstripe -v $name || error "(5.1) cannot getstripe on $name"
 
-	local pattern=0x$($LFS getstripe -L $name)
-	[[ $((pattern & LOV_PATTERN_F_HOLE)) -eq 0 ]] ||
+	local pattern=$($LFS getstripe -L $name)
+	[[ "$pattern" = "$PATTERN_WITHOUT_HOLE" ]] ||
 		error "(5.2) NOT expect pattern flag hole, but got $pattern"
 
 	local stripes=$($LFS getstripe -c $name)
@@ -2248,8 +3162,8 @@ test_20() {
 
 	$LFS getstripe -v $name || error "(6.1) cannot getstripe on $name"
 
-	pattern=0x$($LFS getstripe -L $name)
-	[[ $((pattern & LOV_PATTERN_F_HOLE)) -ne 0 ]] ||
+	pattern=$($LFS getstripe -L $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
 		error "(6.2) expect pattern flag hole, but got $pattern"
 
 	stripes=$($LFS getstripe -c $name)
@@ -2304,13 +3218,13 @@ test_20() {
 
 	$LFS getstripe -v $name || error "(7.1) cannot getstripe on $name"
 
-	pattern=0x$($LFS getstripe -L $name)
+	pattern=$($LFS getstripe -L $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(7.2) expect pattern flag hole, but got $pattern"
+
 	stripes=$($LFS getstripe -c $name)
 	size=$(stat $name | awk '/Size:/ { print $2 }')
 	if [ $OSTCOUNT -gt 2 ]; then
-		[[ $((pattern & LOV_PATTERN_F_HOLE)) -ne 0 ]] ||
-		error "(7.2.1) expect pattern flag hole, but got $pattern"
-
 		[ $stripes -eq 3 ] ||
 		error "(7.3.1) expect the stripe count is 3, but got $stripes"
 
@@ -2344,19 +3258,28 @@ test_20() {
 
 		touch $name || error "(7.10.1) cannot touch $name"
 	else
-		[[ $((pattern & LOV_PATTERN_F_HOLE)) -eq 0 ]] ||
-		error "(7.2.2) NOT expect pattern flag hole, but got $pattern"
-
-		[ $stripes -eq 1 ] ||
-		error "(7.3.2) expect the stripe count is 1, but got $stripes"
+		[ $stripes -eq 2 ] ||
+		error "(7.3.2) expect the stripe count is 2, but got $stripes"
 
 		# stripe1 is dummy
 		[ $size -eq $((4096 * (256 + 0))) ] ||
 		error "(7.4.2) expect the size $((4096 * 256)), but got $size"
 
-		cat $name > /dev/null || error "(7.5.2) cannot read $name"
+		cat $name > /dev/null &&
+			error "(7.5.2) normal read $name should fail"
+
+		failures=$(dd if=$name of=$DIR/$tdir/dump conv=sync,noerror \
+			   bs=4096 2>&1 | grep "Input/output error" | wc -l)
+		[ $failures -eq 256 ] ||
+		error "(7.6.2) expect 256 IO failures, but get $failures"
+
+		bcount=$((256 * 2))
+		size=$(stat $DIR/$tdir/dump | awk '/Size:/ { print $2 }')
+		[ $size -eq $((4096 * $bcount)) ] ||
+		error "(7.7.2) expect the size $((4096 * $bcount)), got $size"
 
-		echo "dummy" >> $name || error "(7.8.2) cannot write $name"
+		dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 \
+		seek=256 && error "(7.8.2) write to the LOV EA hole should fail"
 
 		chown $RUNAS_ID:$RUNAS_GID $name ||
 			error "(7.9.2) cannot chown on $name"
@@ -2376,63 +3299,2278 @@ test_20() {
 
 	$LFS getstripe -v $name || error "(8.1) cannot getstripe on $name"
 
-	pattern=0x$($LFS getstripe -L $name)
-	[[ $((pattern & LOV_PATTERN_F_HOLE)) -eq 0 ]] ||
-		error "(8.2) NOT expect pattern flag hole, but got $pattern"
+	pattern=$($LFS getstripe -L $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(8.2) expect pattern flag hole, but got $pattern"
 
 	stripes=$($LFS getstripe -c $name)
-	# LFSCK does not know the old f3 had 3 stripes.
-	# It only tries to find as much as possible.
-	# The stripe count depends on the last stripe's offset.
-	[ $stripes -eq 2 ] ||
-		error "(8.3) expect the stripe count is 2, but got $stripes"
+	[ $stripes -eq 3 ] ||
+		error "(8.3) expect the stripe count is 3, but got $stripes"
 
 	size=$(stat $name | awk '/Size:/ { print $2 }')
 	# stripe2 is lost
 	[ $size -eq $((4096 * (256 + 256 + 0))) ] ||
 		error "(8.4) expect the size $((4096 * 512)), but got $size"
 
-	cat $name > /dev/null || error "(8.5) cannot read $name"
+	cat $name > /dev/null &&
+		error "(8.5) normal read $name should fail"
+
+	failures=$(dd if=$name of=$DIR/$tdir/dump conv=sync,noerror \
+		   bs=4096 2>&1 | grep "Input/output error" | wc -l)
+	# stripe2 is dummy
+	[ $failures -eq 256 ] ||
+		error "(8.6) expect 256 IO failures, but get $failures"
+
+	bcount=$((256 * 3))
+	size=$(stat $DIR/$tdir/dump | awk '/Size:/ { print $2 }')
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(8.7) expect the size $((4096 * $bcount)), but got $size"
 
-	echo "dummy" >> $name || error "(8.6) cannot write $name"
+	dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 \
+		seek=512 && error "(8.8) write to the LOV EA hole should fail"
 
 	chown $RUNAS_ID:$RUNAS_GID $name ||
-		error "(8.7) cannot chown on $name"
+		error "(8.9) cannot chown on $name"
 
-	touch $name || error "(8.8) cannot touch $name"
+	touch $name || error "(8.10) cannot touch $name"
 
-	rm -f $name || error "(8.9) cannot unlink $name"
+	rm -f $name || error "(8.11) cannot unlink $name"
 }
-run_test 20 "Handle the orphan with dummy LOV EA slot properly"
+run_test 20a "Handle the orphan with dummy LOV EA slot properly"
 
-test_21() {
-	[[ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.5.59) ]] &&
-		skip "ignore the test if MDS is older than 2.5.59" && exit 0
+test_20b() {
+	[ $OSTCOUNT -lt 2 ] && skip "needs >= 2 OSTs" && return
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The target MDT-object and some of its OST-object are lost."
+	echo "The LFSCK should find out the left OST-objects and re-create"
+	echo "the MDT-object under the direcotry .lustre/lost+found/MDTxxxx/"
+	echo "with the partial OST-objects (LOV EA hole)."
+
+	echo "New client can access the file with LOV EA hole via normal"
+	echo "system tools or commands without crash the system - PFL case."
+	echo "#####"
 
 	check_mount_and_prep
-	createmany -o $DIR/$tdir/f 100 || error "(0) Fail to create 100 files"
 
-	echo "Start all LFSCK components by default (-s 1)"
-	do_facet mds1 $LCTL lfsck_start -M ${FSNAME}-MDT0000 -s 1 -r ||
-		error "Fail to start LFSCK"
+	$LFS setstripe -E 2M -S 1M -c 2 -E -1 -S 1M -c 2 $DIR/$tdir/f0 ||
+		error "(0) Fail to create PFL file $DIR/$tdir/f0"
+	$LFS setstripe -E 2M -S 1M -c 2 -E -1 -S 1M -c 2 $DIR/$tdir/f1 ||
+		error "(1) Fail to create PFL file $DIR/$tdir/f1"
+	$LFS setstripe -E 2M -S 1M -c 2 -E -1 -S 1M -c 2 $DIR/$tdir/f2 ||
+		error "(2) Fail to create PFL file $DIR/$tdir/f2"
 
-	echo "namespace LFSCK should be in 'scanning-phase1' status"
-	local STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
-	[ "$STATUS" == "scanning-phase1" ] ||
-		error "Expect namespace 'scanning-phase1', but got '$STATUS'"
+	local bcount=$((256 * 3 + 1))
 
-	echo "layout LFSCK should be in 'scanning-phase1' status"
-	STATUS=$($SHOW_LAYOUT | awk '/^status/ { print $2 }')
-	[ "$STATUS" == "scanning-phase1" ] ||
-		error "Expect layout 'scanning-phase1', but got '$STATUS'"
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=4096 count=$bcount
+	dd if=/dev/zero of=$DIR/$tdir/f1 bs=4096 count=$bcount
+	dd if=/dev/zero of=$DIR/$tdir/f2 bs=4096 count=$bcount
 
-	echo "Stop all LFSCK components by default"
-	do_facet mds1 $LCTL lfsck_stop -M ${FSNAME}-MDT0000 ||
-		error "Fail to stop LFSCK"
-}
-run_test 21 "run all LFSCK components by default"
+	local fid0=$($LFS path2fid $DIR/$tdir/f0)
+	local fid1=$($LFS path2fid $DIR/$tdir/f1)
+	local fid2=$($LFS path2fid $DIR/$tdir/f2)
+
+	echo ${fid0}
+	$LFS getstripe $DIR/$tdir/f0
+	echo ${fid1}
+	$LFS getstripe $DIR/$tdir/f1
+	echo ${fid2}
+	$LFS getstripe $DIR/$tdir/f2
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	echo "Inject failure..."
+	echo "To simulate f0 lost MDT-object"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1616
+	rm -f $DIR/$tdir/f0
+
+	echo "To simulate the case of f1 lost MDT-object and "
+	echo "the first OST-object in each PFL component"
+	#define OBD_FAIL_LFSCK_LOST_SPEOBJ	0x161a
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x161a
+	rm -f $DIR/$tdir/f1
+
+	echo "To simulate the case of f2 lost MDT-object and "
+	echo "the second OST-object in each PFL component"
+	do_facet $SINGLEMDS $LCTL set_param fail_val=1
+	rm -f $DIR/$tdir/f2
+
+	sync
+	sleep 2
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
+
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(3) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			error "(4) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		local cur_status=$(do_facet ost${k} $LCTL get_param -n \
+				obdfilter.$(facet_svc ost${k}).lfsck_layout |
+				awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(5) OST${k} Expect 'completed', but got '$cur_status'"
+	done
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq 8 ] ||
+		error "(6) Expect 8 fixed on mds1, but got: $repaired"
+
+	#
+	# ${fid0}-R-0 is the old f0
+	#
+	local name="$MOUNT/.lustre/lost+found/MDT0000/${fid0}-R-0"
+	echo "Check $name, which is the old f0"
+
+	$LFS getstripe -v $name || error "(7.1) cannot getstripe on $name"
+
+	local pattern=$($LFS getstripe -L -I1 $name)
+	[[ "$pattern" = "$PATTERN_WITHOUT_HOLE" ]] ||
+		error "(7.2.1) NOT expect pattern flag hole, but got $pattern"
+
+	pattern=$($LFS getstripe -L -I2 $name)
+	[[ "$pattern" = "$PATTERN_WITHOUT_HOLE" ]] ||
+		error "(7.2.2) NOT expect pattern flag hole, but got $pattern"
+
+	local stripes=$($LFS getstripe -c -I1 $name)
+	[ $stripes -eq 2 ] ||
+		error "(7.3.1) expect 2 stripes, but got $stripes"
+
+	stripes=$($LFS getstripe -c -I2 $name)
+	[ $stripes -eq 2 ] ||
+		error "(7.3.2) expect 2 stripes, but got $stripes"
+
+	local e_start=$($LFS getstripe -I1 $name |
+			awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 0 ] ||
+		error "(7.4.1) expect the COMP1 start at 0, got $e_start"
+
+	local e_end=$($LFS getstripe -I1 $name |
+		      awk '/lcme_extent.e_end:/ { print $2 }')
+	[ $e_end -eq 2097152 ] ||
+		error "(7.4.2) expect the COMP1 end at 2097152, got $e_end"
+
+	e_start=$($LFS getstripe -I2 $name |
+		  awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 2097152 ] ||
+		error "(7.5.1) expect the COMP2 start at 2097152, got $e_start"
+
+	e_end=$($LFS getstripe -I2 $name |
+		awk '/lcme_extent.e_end:/ { print $2 }')
+	[ "$e_end" = "EOF" ] ||
+		error "(7.5.2) expect the COMP2 end at (EOF), got $e_end"
+
+	local size=$(stat $name | awk '/Size:/ { print $2 }')
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(7.6) expect the size $((4096 * $bcount)), but got $size"
+
+	cat $name > /dev/null || error "(7.7) cannot read $name"
+
+	echo "dummy" >> $name || error "(7.8) cannot write $name"
+
+	chown $RUNAS_ID:$RUNAS_GID $name || error "(7.9) cannot chown on $name"
+
+	touch $name || error "(7.10) cannot touch $name"
+
+	rm -f $name || error "(7.11) cannot unlink $name"
+
+	#
+	# ${fid1}-R-0 contains the old f1's second stripe in each COMP
+	#
+	name="$MOUNT/.lustre/lost+found/MDT0000/${fid1}-R-0"
+	echo "Check $name, it contains f1's second OST-object in each COMP"
+
+	$LFS getstripe -v $name || error "(8.1) cannot getstripe on $name"
+
+	pattern=$($LFS getstripe -L -I1 $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(8.2.1) expect pattern flag hole, but got $pattern"
+
+	pattern=$($LFS getstripe -L -I2 $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(8.2.2) expect pattern flag hole, but got $pattern"
+
+	stripes=$($LFS getstripe -c -I1 $name)
+	[ $stripes -eq 2 ] ||
+		error "(8.3.2) expect 2 stripes, but got $stripes"
+
+	stripes=$($LFS getstripe -c -I2 $name)
+	[ $stripes -eq 2 ] ||
+		error "(8.3.2) expect 2 stripes, but got $stripes"
+
+	e_start=$($LFS getstripe -I1 $name |
+		  awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 0 ] ||
+		error "(8.4.1) expect the COMP1 start at 0, got $e_start"
+
+	e_end=$($LFS getstripe -I1 $name |
+		awk '/lcme_extent.e_end:/ { print $2 }')
+	[ $e_end -eq 2097152 ] ||
+		error "(8.4.2) expect the COMP1 end at 2097152, got $e_end"
+
+	e_start=$($LFS getstripe -I2 $name |
+		  awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 2097152 ] ||
+		error "(8.5.1) expect the COMP2 start at 2097152, got $e_start"
+
+	e_end=$($LFS getstripe -I2 $name |
+		awk '/lcme_extent.e_end:/ { print $2 }')
+	[ "$e_end" = "EOF" ] ||
+		error "(8.5.2) expect the COMP2 end at (EOF), got $e_end"
+
+	size=$(stat $name | awk '/Size:/ { print $2 }')
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(8.6) expect the size $((4096 * $bcount)), but got $size"
+
+	cat $name > /dev/null && error "(8.7) normal read $name should fail"
+
+	local failures=$(dd if=$name of=$DIR/$tdir/dump conv=sync,noerror \
+			 bs=4096 2>&1 | grep "Input/output error" | wc -l)
+
+	# The first stripe in each COMP was lost
+	[ $failures -eq 512 ] ||
+		error "(8.8) expect 512 IO failures, but get $failures"
+
+	size=$(stat $DIR/$tdir/dump | awk '/Size:/ { print $2 }')
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(8.9) expect the size $((4096 * $bcount)), but got $size"
+
+	dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 &&
+		error "(8.10) write to the LOV EA hole should fail"
+
+	dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 seek=300 ||
+		error "(8.11) write to normal stripe should NOT fail"
+
+	echo "foo" >> $name && error "(8.12) append write $name should fail"
+
+	chown $RUNAS_ID:$RUNAS_GID $name || error "(8.13) cannot chown on $name"
+
+	touch $name || error "(8.14) cannot touch $name"
+
+	rm -f $name || error "(8.15) cannot unlink $name"
+
+	#
+	# ${fid2}-R-0 contains the old f2's first stripe in each COMP
+	#
+	name="$MOUNT/.lustre/lost+found/MDT0000/${fid2}-R-0"
+	echo "Check $name, it contains f2's first stripe in each COMP"
+
+	$LFS getstripe -v $name || error "(9.1) cannot getstripe on $name"
+
+	pattern=$($LFS getstripe -L -I1 $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(9.2.1) expect pattern flag hole, but got $pattern"
+
+	pattern=$($LFS getstripe -L -I2 $name)
+	[[ "$pattern" = "$PATTERN_WITH_HOLE" ]] ||
+		error "(9.2.2) expect pattern flag hole, but got $pattern"
+
+	stripes=$($LFS getstripe -c -I1 $name)
+	[ $stripes -eq 2 ] ||
+		error "(9.3.2) expect 2 stripes, but got $stripes"
+
+	stripes=$($LFS getstripe -c -I2 $name)
+	[ $stripes -eq 2 ] ||
+		error "(9.3.2) expect 2 stripes, but got $stripes"
+
+	e_start=$($LFS getstripe -I1 $name |
+		  awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 0 ] ||
+		error "(9.4.1) expect the COMP1 start at 0, got $e_start"
+
+	e_end=$($LFS getstripe -I1 $name |
+		awk '/lcme_extent.e_end:/ { print $2 }')
+	[ $e_end -eq 2097152 ] ||
+		error "(9.4.2) expect the COMP1 end at 2097152, got $e_end"
+
+	e_start=$($LFS getstripe -I2 $name |
+		  awk '/lcme_extent.e_start:/ { print $2 }')
+	[ $e_start -eq 2097152 ] ||
+		error "(9.5.1) expect the COMP2 start at 2097152, got $e_start"
+
+	e_end=$($LFS getstripe -I2 $name |
+		awk '/lcme_extent.e_end:/ { print $2 }')
+	[ "$e_end" = "EOF" ] ||
+		error "(9.5.2) expect the COMP2 end at (EOF), got $e_end"
+
+	size=$(stat $name | awk '/Size:/ { print $2 }')
+	# The second stripe in COMP was lost, so we do not know there
+	# have ever been some data before. 'stat' will regard it as
+	# no data on the lost stripe.
+	bcount=$((256 * 3))
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(9.6) expect size $((4096 * $bcount)), but got $size"
+
+	cat $name > /dev/null &&
+		error "(9.7) normal read $name should fail"
+
+	failures=$(dd if=$name of=$DIR/$tdir/dump conv=sync,noerror \
+		   bs=4096 2>&1 | grep "Input/output error" | wc -l)
+	[ $failures -eq 512 ] ||
+		error "(9.8) expect 256 IO failures, but get $failures"
+
+	size=$(stat $DIR/$tdir/dump | awk '/Size:/ { print $2 }')
+	# The second stripe in COMP was lost, so we do not know there
+	# have ever been some data before. Since 'dd' skip failure,
+	# it will regard the lost stripe contains data.
+	bcount=$((256 * 4))
+	[ $size -eq $((4096 * $bcount)) ] ||
+		error "(9.9) expect the size $((4096 * $bcount)), but got $size"
+
+	dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 \
+		seek=300 && error "(9.10) write to the LOV EA hole should fail"
+
+	dd if=/dev/zero of=$name conv=sync,notrunc bs=4096 count=1 ||
+		error "(9.11) write to normal stripe should NOT fail"
+
+	echo "foo" >> $name &&
+		error "(9.12) append write $name should fail"
+
+	chown $RUNAS_ID:$RUNAS_GID $name ||
+		error "(9.13) cannot chown on $name"
+
+	touch $name || error "(9.14) cannot touch $name"
+
+	rm -f $name || error "(7.15) cannot unlink $name"
+}
+run_test 20b "Handle the orphan with dummy LOV EA slot properly - PFL case"
+
+test_21() {
+	[[ $(lustre_version_code $SINGLEMDS) -lt $(version_code 2.5.59) ]] &&
+		skip "ignore the test if MDS is older than 2.5.59" && return
+
+	check_mount_and_prep
+	createmany -o $DIR/$tdir/f 100 || error "(0) Fail to create 100 files"
+
+	echo "Start all LFSCK components by default (-s 1)"
+	do_facet mds1 $LCTL lfsck_start -M ${FSNAME}-MDT0000 -s 1 -r ||
+		error "Fail to start LFSCK"
+
+	echo "namespace LFSCK should be in 'scanning-phase1' status"
+	local STATUS=$($SHOW_NAMESPACE | awk '/^status/ { print $2 }')
+	[ "$STATUS" == "scanning-phase1" ] ||
+		error "Expect namespace 'scanning-phase1', but got '$STATUS'"
+
+	echo "layout LFSCK should be in 'scanning-phase1' status"
+	STATUS=$($SHOW_LAYOUT | awk '/^status/ { print $2 }')
+	[ "$STATUS" == "scanning-phase1" ] ||
+		error "Expect layout 'scanning-phase1', but got '$STATUS'"
+
+	echo "Stop all LFSCK components by default"
+	do_facet mds1 $LCTL lfsck_stop -M ${FSNAME}-MDT0000 ||
+		error "Fail to stop LFSCK"
+}
+run_test 21 "run all LFSCK components by default"
+
+test_22a() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "The parent_A references the child directory via some name entry,"
+	echo "but the child directory back references another parent_B via its"
+	echo "".." name entry. The parent_B does not exist. Then the namespace"
+	echo "LFSCK will repair the child directory's ".." name entry."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/guard || error "(1) Fail to mkdir on MDT1"
+	$LFS mkdir -i 1 $DIR/$tdir/foo || error "(2) Fail to mkdir on MDT1"
+
+	echo "Inject failure stub on MDT0 to simulate bad dotdot name entry"
+	echo "The dummy's dotdot name entry references the guard."
+	#define OBD_FAIL_LFSCK_BAD_PARENT	0x161e
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x161e
+	$LFS mkdir -i 0 $DIR/$tdir/foo/dummy ||
+		error "(3) Fail to mkdir on MDT0"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	rmdir $DIR/$tdir/guard || error "(4) Fail to rmdir $DIR/$tdir/guard"
+
+	echo "Trigger namespace LFSCK to repair unmatched pairs"
+	$START_NAMESPACE -A -r ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^unmatched_pairs_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair unmatched pairs: $repaired"
+
+	echo "'ls' should success after namespace LFSCK repairing"
+	ls -ail $DIR/$tdir/foo/dummy > /dev/null ||
+		error "(8) ls should success."
+}
+run_test 22a "LFSCK can repair unmatched pairs (1)"
+
+test_22b() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "The parent_A references the child directory via the name entry_B,"
+	echo "but the child directory back references another parent_C via its"
+	echo "".." name entry. The parent_C exists, but there is no the name"
+	echo "entry_B under the parent_C. Then the namespace LFSCK will repair"
+	echo "the child directory's ".." name entry and its linkEA."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/guard || error "(1) Fail to mkdir on MDT1"
+	$LFS mkdir -i 1 $DIR/$tdir/foo || error "(2) Fail to mkdir on MDT1"
+
+	echo "Inject failure stub on MDT0 to simulate bad dotdot name entry"
+	echo "and bad linkEA. The dummy's dotdot name entry references the"
+	echo "guard. The dummy's linkEA references n non-exist name entry."
+	#define OBD_FAIL_LFSCK_BAD_PARENT	0x161e
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x161e
+	$LFS mkdir -i 0 $DIR/$tdir/foo/dummy ||
+		error "(3) Fail to mkdir on MDT0"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	local dummyfid=$($LFS path2fid $DIR/$tdir/foo/dummy)
+	echo "fid2path should NOT work on the dummy's FID $dummyfid"
+	local dummyname=$($LFS fid2path $DIR $dummyfid)
+	[ "$dummyname" != "$DIR/$tdir/foo/dummy" ] ||
+		error "(4) fid2path works unexpectedly."
+
+	echo "Trigger namespace LFSCK to repair unmatched pairs"
+	$START_NAMESPACE -A -r ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^unmatched_pairs_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair unmatched pairs: $repaired"
+
+	echo "fid2path should work on the dummy's FID $dummyfid after LFSCK"
+	local dummyname=$($LFS fid2path $DIR $dummyfid)
+	[ "$dummyname" == "$DIR/$tdir/foo/dummy" ] ||
+		error "(8) fid2path does not work"
+}
+run_test 22b "LFSCK can repair unmatched pairs (2)"
+
+test_23a() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "The name entry is there, but the MDT-object for such name "
+	echo "entry does not exist. The namespace LFSCK should find out "
+	echo "and repair the inconsistency as required."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0 on MDT0"
+	$LFS mkdir -i 1 $DIR/$tdir/d0/d1 || error "(2) Fail to mkdir d1 on MDT1"
+
+	echo "Inject failure stub on MDT1 to simulate dangling name entry"
+	#define OBD_FAIL_LFSCK_DANGLING2	0x1620
+	do_facet mds2 $LCTL set_param fail_loc=0x1620
+	rmdir $DIR/$tdir/d0/d1 || error "(3) Fail to rmdir d1"
+	do_facet mds2 $LCTL set_param fail_loc=0
+
+	echo "'ls' should fail because of dangling name entry"
+	ls -ail $DIR/$tdir/d0/d1 > /dev/null 2>&1 && error "(4) ls should fail."
+
+	echo "Trigger namespace LFSCK to find out dangling name entry"
+	$START_NAMESPACE -A -r ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dangling_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair dangling name entry: $repaired"
+
+	echo "'ls' should fail because not re-create MDT-object by default"
+	ls -ail $DIR/$tdir/d0/d1 > /dev/null 2>&1 && error "(8) ls should fail."
+
+	echo "Trigger namespace LFSCK again to repair dangling name entry"
+	$START_NAMESPACE -A -r -C ||
+		error "(9) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 10
+
+	repaired=$($SHOW_NAMESPACE |
+		   awk '/^dangling_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(11) Fail to repair dangling name entry: $repaired"
+
+	echo "'ls' should success after namespace LFSCK repairing"
+	ls -ail $DIR/$tdir/d0/d1 > /dev/null || error "(12) ls should success."
+}
+run_test 23a "LFSCK can repair dangling name entry (1)"
+
+test_23b() {
+	echo "#####"
+	echo "The objectA has multiple hard links, one of them corresponding"
+	echo "to the name entry_B. But there is something wrong for the name"
+	echo "entry_B and cause entry_B to references non-exist object_C."
+	echo "In the first-stage scanning, the LFSCK will think the entry_B"
+	echo "as dangling, and re-create the lost object_C. When the LFSCK"
+	echo "comes to the second-stage scanning, it will find that the"
+	echo "former re-creating object_C is not proper, and will try to"
+	echo "replace the object_C with the real object_A."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0 on MDT0"
+	$LFS path2fid $DIR/$tdir/d0
+
+	createmany -o $DIR/$tdir/d0/t 10 || error "(1.5) Fail to creatmany"
+
+	echo "dummy" > $DIR/$tdir/d0/f0 || error "(2) Fail to touch on MDT0"
+	$LFS path2fid $DIR/$tdir/d0/f0
+
+	echo "dead" > $DIR/$tdir/d0/f1 || error "(3) Fail to touch on MDT0"
+	$LFS path2fid $DIR/$tdir/d0/f1
+
+	local SEQ0=$($LFS path2fid $DIR/$tdir/d0/f0 | awk -F':' '{print $1}')
+	local SEQ1=$($LFS path2fid $DIR/$tdir/d0/f1 | awk -F':' '{print $1}')
+
+	if [ "$SEQ0" != "$SEQ1" ]; then
+		# To guarantee that the f0 and f1 are in the same FID seq
+		rm -f $DIR/$tdir/d0/f0 ||
+			error "(3.1) Fail to unlink $DIR/$tdir/d0/f0"
+		echo "dummy" > $DIR/$tdir/d0/f0 ||
+			error "(3.2) Fail to touch on MDT0"
+		$LFS path2fid $DIR/$tdir/d0/f0
+	fi
+
+	local OID=$($LFS path2fid $DIR/$tdir/d0/f1 | awk -F':' '{print $2}')
+	OID=$(printf %d $OID)
+
+	echo "Inject failure stub on MDT0 to simulate dangling name entry"
+	#define OBD_FAIL_LFSCK_DANGLING3	0x1621
+	do_facet $SINGLEMDS $LCTL set_param fail_val=$OID fail_loc=0x1621
+	ln $DIR/$tdir/d0/f0 $DIR/$tdir/d0/foo || error "(4) Fail to hard link"
+	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0
+
+	# If there is creation after the dangling injection, it may re-use
+	# the just released local object (inode) that is referenced by the
+	# dangling name entry. It will fail the dangling injection.
+	# So before deleting the target object for the dangling name entry,
+	# remove some other objects to avoid the target object being reused
+	# by some potential creations. LU-7429
+	unlinkmany $DIR/$tdir/d0/t 10 || error "(5.0) Fail to unlinkmany"
+
+	rm -f $DIR/$tdir/d0/f1 || error "(5) Fail to unlink $DIR/$tdir/d0/f1"
+
+	echo "'ls' should fail because of dangling name entry"
+	ls -ail $DIR/$tdir/d0/foo > /dev/null 2>&1 &&
+		error "(6) ls should fail."
+
+	echo "Trigger namespace LFSCK to find out dangling name entry"
+	$START_NAMESPACE -r -C ||
+		error "(7) Fail to start LFSCK for namespace"
+
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(8) unexpected status"
+	}
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dangling_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(9) Fail to repair dangling name entry: $repaired"
+
+	repaired=$($SHOW_NAMESPACE |
+		   awk '/^multiple_linked_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(10) Fail to drop the former created object: $repaired"
+
+	local data=$(cat $DIR/$tdir/d0/foo)
+	[ "$data" == "dummy" ] ||
+		error "(11) The $DIR/$tdir/d0/foo is not recovered: $data"
+}
+run_test 23b "LFSCK can repair dangling name entry (2)"
+
+cleanup_23c() {
+	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(10) unexpected status"
+	}
+
+	stop_full_debug_logging
+}
+
+test_23c() {
+	echo "#####"
+	echo "The objectA has multiple hard links, one of them corresponding"
+	echo "to the name entry_B. But there is something wrong for the name"
+	echo "entry_B and cause entry_B to references non-exist object_C."
+	echo "In the first-stage scanning, the LFSCK will think the entry_B"
+	echo "as dangling, and re-create the lost object_C. And then others"
+	echo "modified the re-created object_C. When the LFSCK comes to the"
+	echo "second-stage scanning, it will find that the former re-creating"
+	echo "object_C maybe wrong and try to replace the object_C with the"
+	echo "real object_A. But because object_C has been modified, so the"
+	echo "LFSCK cannot replace it."
+	echo "#####"
+
+	start_full_debug_logging
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0 on MDT0"
+	parent_fid="$($LFS path2fid $DIR/$tdir/d0)"
+	echo "parent_fid=$parent_fid"
+
+	createmany -o $DIR/$tdir/d0/t 10 || error "(1.5) Fail to creatmany"
+
+	echo "dummy" > $DIR/$tdir/d0/f0 || error "(2) Fail to touch on MDT0"
+	f0_fid="$($LFS path2fid $DIR/$tdir/d0/f0)"
+	echo "f0_fid=$f0_fid"
+
+	echo "dead" > $DIR/$tdir/d0/f1 || error "(3) Fail to touch on MDT0"
+	f1_fid="$($LFS path2fid $DIR/$tdir/d0/f1)"
+	echo "f1_fid=$f1_fid"
+
+	if [ "${fid_f0/:.*/}" != "${fid_f1/:.*/}" ]; then
+		# To guarantee that the f0 and f1 are in the same FID seq
+		rm -f $DIR/$tdir/d0/f0 ||
+			error "(3.1) Fail to unlink $DIR/$tdir/d0/f0"
+		echo "dummy" > $DIR/$tdir/d0/f0 ||
+			error "(3.2) Fail to touch on MDT0"
+		f0_fid="$($LFS path2fid $DIR/$tdir/d0/f0)"
+		echo "f0_fid=$f0_fid (replaced)"
+	fi
+
+	local oid=$(awk -F':' '{ printf $2 }' <<< $f1_fid)
+
+	echo "Inject failure stub on MDT0 to simulate dangling name entry"
+	#define OBD_FAIL_LFSCK_DANGLING3	0x1621
+	do_facet $SINGLEMDS $LCTL set_param fail_val=$oid fail_loc=0x1621
+	ln $DIR/$tdir/d0/f0 $DIR/$tdir/d0/foo || error "(4) Fail to hard link"
+	do_facet $SINGLEMDS $LCTL set_param fail_val=0 fail_loc=0
+
+	# If there is creation after the dangling injection, it may re-use
+	# the just released local object (inode) that is referenced by the
+	# dangling name entry. It will fail the dangling injection.
+	# So before deleting the target object for the dangling name entry,
+	# remove some other objects to avoid the target object being reused
+	# by some potential creations. LU-7429
+	unlinkmany $DIR/$tdir/d0/t 10 || error "(5.0) Fail to unlinkmany"
+
+	rm -f $DIR/$tdir/d0/f1 || error "(5) Fail to unlink $DIR/$tdir/d0/f1"
+
+	echo "'ls' should fail because of dangling name entry"
+	ls -ail $DIR/$tdir/d0/foo > /dev/null 2>&1 &&
+		error "(6) ls should fail."
+
+	#define OBD_FAIL_LFSCK_DELAY3		0x1602
+	do_facet $SINGLEMDS $LCTL set_param fail_val=10 fail_loc=0x1602
+
+	echo "Trigger namespace LFSCK to find out dangling name entry"
+	$START_NAMESPACE -r -C ||
+		error "(7) Fail to start LFSCK for namespace"
+
+	wait_update_facet client "stat -c%s $DIR/$tdir/d0/foo" "0" $LTIME || {
+		# While unexpected by the test, it is valid for LFSCK to repair
+		# the link to the original object before any data is written.
+		local size=$(stat -c %s $DIR/$tdir/d0/foo)
+
+		if [ "$size" = "6" -a "$(<$DIR/$tdir/d0/foo)" = "dummy" ]; then
+			log "LFSCK repaired file prematurely"
+			cleanup_23c
+			return 0
+		fi
+
+		stat $DIR/$tdir/d0/foo
+		$SHOW_NAMESPACE
+		error "(8) unexpected size"
+	}
+
+	echo "data" >> $DIR/$tdir/d0/foo || error "(9) Fail to write"
+	cancel_lru_locks osc
+
+	cleanup_23c
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dangling_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(11) Fail to repair dangling name entry: $repaired"
+
+	local data=$(cat $DIR/$tdir/d0/foo)
+	[ "$data" != "dummy" ] ||
+		error "(12) The $DIR/$tdir/d0/foo should not be recovered"
+}
+run_test 23c "LFSCK can repair dangling name entry (3)"
+
+test_24() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "Two MDT-objects back reference the same name entry via their"
+	echo "each own linkEA entry, but the name entry only references one"
+	echo "MDT-object. The namespace LFSCK will remove the linkEA entry"
+	echo "for the MDT-object that is not recognized. If such MDT-object"
+	echo "has no other linkEA entry after the removing, then the LFSCK"
+	echo "will add it as orphan under the .lustre/lost+found/MDTxxxx/."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+
+	mkdir $DIR/$tdir/d0/guard || error "(1) Fail to mkdir guard"
+	$LFS path2fid $DIR/$tdir/d0/guard
+
+	mkdir $DIR/$tdir/d0/dummy || error "(2) Fail to mkdir dummy"
+	$LFS path2fid $DIR/$tdir/d0/dummy
+
+	local pfid
+	if [ $(facet_fstype $SINGLEMDS) != ldiskfs ]; then
+		pfid=$($LFS path2fid $DIR/$tdir/d0/guard)
+	else
+		pfid=$($LFS path2fid $DIR/$tdir/d0/dummy)
+	fi
+
+	touch $DIR/$tdir/d0/guard/foo ||
+		error "(3) Fail to touch $DIR/$tdir/d0/guard/foo"
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "the $DIR/$tdir/d0/dummy/foo has the 'bad' linkEA entry"
+	echo "that references $DIR/$tdir/d0/guard/foo."
+	echo "Then remove the name entry $DIR/$tdir/d0/dummy/foo."
+	echo "So the MDT-object $DIR/$tdir/d0/dummy/foo will be left"
+	echo "there with the same linkEA entry as another MDT-object"
+	echo "$DIR/$tdir/d0/guard/foo has"
+
+	#define OBD_FAIL_LFSCK_MUL_REF		0x1622
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1622
+	$LFS mkdir -i 0 $DIR/$tdir/d0/dummy/foo ||
+		error "(4) Fail to mkdir $DIR/$tdir/d0/dummy/foo"
+	$LFS path2fid $DIR/$tdir/d0/dummy/foo
+	local cfid=$($LFS path2fid $DIR/$tdir/d0/dummy/foo)
+	rmdir $DIR/$tdir/d0/dummy/foo ||
+		error "(5) Fail to remove $DIR/$tdir/d0/dummy/foo name entry"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	echo "stat $DIR/$tdir/d0/dummy/foo should fail"
+	stat $DIR/$tdir/d0/dummy/foo > /dev/null 2>&1 &&
+		error "(6) stat successfully unexpectedly"
+
+	echo "Trigger namespace LFSCK to repair multiple-referenced name entry"
+	$START_NAMESPACE -A -r ||
+		error "(7) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 8
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^multiple_referenced_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+	error "(9) Fail to repair multiple referenced name entry: $repaired"
+
+	echo "There should be an orphan under .lustre/lost+found/MDT0000/"
+	[ -d $MOUNT/.lustre/lost+found/MDT0000 ] ||
+		error "(10) $MOUNT/.lustre/lost+found/MDT0000/ should be there"
+
+	local cname="$cfid-$pfid-D-0"
+	ls -ail $MOUNT/.lustre/lost+found/MDT0000/$cname ||
+		error "(11) .lustre/lost+found/MDT0000/ should not be empty"
+}
+run_test 24 "LFSCK can repair multiple-referenced name entry"
+
+test_25() {
+	[ $(facet_fstype $SINGLEMDS) != ldiskfs ] &&
+		skip "ldiskfs only test" && return
+
+	echo "#####"
+	echo "The file type in the name entry does not match the file type"
+	echo "claimed by the referenced object. Then the LFSCK will update"
+	echo "the file type in the name entry."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "the file type stored in the name entry is wrong."
+
+	#define OBD_FAIL_LFSCK_BAD_TYPE		0x1623
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1623
+	touch $DIR/$tdir/d0/foo || error "(2) Fail to touch $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	echo "Trigger namespace LFSCK to repair bad file type in the name entry"
+	$START_NAMESPACE -r || error "(3) Fail to start LFSCK for namespace"
+
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(4) unexpected status"
+	}
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^bad_file_type_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+	error "(5) Fail to repair bad file type in name entry: $repaired"
+
+	ls -ail $DIR/$tdir/d0 || error "(6) Fail to 'ls' the $DIR/$tdir/d0"
+}
+run_test 25 "LFSCK can repair bad file type in the name entry"
+
+test_26a() {
+	echo "#####"
+	echo "The local name entry back referenced by the MDT-object is lost."
+	echo "The namespace LFSCK will add the missing local name entry back"
+	echo "to the normal namespace."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	touch $DIR/$tdir/d0/foo || error "(2) Fail to create foo"
+	local foofid=$($LFS path2fid $DIR/$tdir/d0/foo)
+
+	ln $DIR/$tdir/d0/foo $DIR/$tdir/d0/dummy ||
+		error "(3) Fail to hard link to $DIR/$tdir/d0/foo"
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "foo's name entry will be removed, but the foo's object"
+	echo "and its linkEA are kept in the system."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1624
+	rm -f $DIR/$tdir/d0/foo || error "(4) Fail to unlink $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	ls -ail $DIR/$tdir/d0/foo > /dev/null 2>&1 &&
+		error "(5) 'ls' should fail"
+
+	echo "Trigger namespace LFSCK to repair the missing remote name entry"
+	$START_NAMESPACE -r -A ||
+		error "(6) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 7
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(8) Fail to repair lost dirent: $repaired"
+
+	ls -ail $DIR/$tdir/d0/foo ||
+		error "(9) Fail to 'ls' $DIR/$tdir/d0/foo"
+
+	local foofid2=$($LFS path2fid $DIR/$tdir/d0/foo)
+	[ "$foofid" == "$foofid2" ] ||
+		error "(10) foo's FID changed: $foofid, $foofid2"
+}
+run_test 26a "LFSCK can add the missing local name entry back to the namespace"
+
+test_26b() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "The remote name entry back referenced by the MDT-object is lost."
+	echo "The namespace LFSCK will add the missing remote name entry back"
+	echo "to the normal namespace."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	$LFS mkdir -i 0 $DIR/$tdir/d0/foo || error "(2) Fail to mkdir foo"
+	local foofid=$($LFS path2fid $DIR/$tdir/d0/foo)
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "foo's name entry will be removed, but the foo's object"
+	echo "and its linkEA are kept in the system."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1624
+	rmdir $DIR/$tdir/d0/foo || error "(3) Fail to rmdir $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	ls -ail $DIR/$tdir/d0/foo > /dev/null 2>&1 &&
+		error "(4) 'ls' should fail"
+
+	echo "Trigger namespace LFSCK to repair the missing remote name entry"
+	$START_NAMESPACE -r -A ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair lost dirent: $repaired"
+
+	ls -ail $DIR/$tdir/d0/foo ||
+		error "(8) Fail to 'ls' $DIR/$tdir/d0/foo"
+
+	local foofid2=$($LFS path2fid $DIR/$tdir/d0/foo)
+	[ "$foofid" == "$foofid2" ] ||
+		error "(9) foo's FID changed: $foofid, $foofid2"
+}
+run_test 26b "LFSCK can add the missing remote name entry back to the namespace"
+
+test_27a() {
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The local parent referenced by the MDT-object linkEA is lost."
+	echo "The namespace LFSCK will re-create the lost parent as orphan."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	touch $DIR/$tdir/d0/foo || error "(2) Fail to create foo"
+	ln $DIR/$tdir/d0/foo $DIR/$tdir/d0/dummy ||
+		error "(3) Fail to hard link to $DIR/$tdir/d0/foo"
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "foo's name entry will be removed, but the foo's object"
+	echo "and its linkEA are kept in the system. And then remove"
+	echo "another hard link and the parent directory."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1624
+	rm -f $DIR/$tdir/d0/foo ||
+		error "(4) Fail to unlink $DIR/$tdir/d0/foo"
+	rm -f $DIR/$tdir/d0/dummy ||
+		error "(5) Fail to unlink $DIR/$tdir/d0/dummy"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	rm -rf $DIR/$tdir/d0 || error "(5) Fail to unlink the dir d0"
+	ls -ail $DIR/$tdir/d0 > /dev/null 2>&1 && error "(6) 'ls' should fail"
+
+	echo "Trigger namespace LFSCK to repair the lost parent"
+	$START_NAMESPACE -r -A ||
+		error "(6) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 7
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(8) Fail to repair lost dirent: $repaired"
+
+	echo "There should be an orphan under .lustre/lost+found/MDT0000/"
+	[ -d $MOUNT/.lustre/lost+found/MDT0000 ] ||
+		error "(9) $MOUNT/.lustre/lost+found/MDT0000/ should be there"
+
+	ls -ail $MOUNT/.lustre/lost+found/MDT0000/
+
+	cname=$(find $MOUNT/.lustre/lost+found/MDT0000/ -name *-P-*)
+	[ ! -z "$cname" ] ||
+		error "(10) .lustre/lost+found/MDT0000/ should not be empty"
+}
+run_test 27a "LFSCK can recreate the lost local parent directory as orphan"
+
+test_27b() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The remote parent referenced by the MDT-object linkEA is lost."
+	echo "The namespace LFSCK will re-create the lost parent as orphan."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 1 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	$LFS mkdir -i 0 $DIR/$tdir/d0/foo || error "(2) Fail to mkdir foo"
+
+	$LFS path2fid $DIR/$tdir/d0
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "foo's name entry will be removed, but the foo's object"
+	echo "and its linkEA are kept in the system. And then remove"
+	echo "the parent directory."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1624
+	rmdir $DIR/$tdir/d0/foo || error "(3) Fail to rmdir $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	rmdir $DIR/$tdir/d0 || error "(4) Fail to unlink the dir d0"
+	ls -ail $DIR/$tdir/d0 > /dev/null 2>&1 && error "(5) 'ls' should fail"
+
+	echo "Trigger namespace LFSCK to repair the missing remote name entry"
+	$START_NAMESPACE -r -A ||
+		error "(6) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 7
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(8) Fail to repair lost dirent: $repaired"
+
+	ls -ail $MOUNT/.lustre/lost+found/
+
+	echo "There should be an orphan under .lustre/lost+found/MDT0001/"
+	[ -d $MOUNT/.lustre/lost+found/MDT0001 ] ||
+		error "(9) $MOUNT/.lustre/lost+found/MDT0001/ should be there"
+
+	ls -ail $MOUNT/.lustre/lost+found/MDT0001/
+
+	cname=$(find $MOUNT/.lustre/lost+found/MDT0001/ -name *-P-*)
+	[ ! -z "$cname" ] ||
+		error "(10) .lustre/lost+found/MDT0001/ should not be empty"
+}
+run_test 27b "LFSCK can recreate the lost remote parent directory as orphan"
+
+test_28() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "The target name entry is lost. The LFSCK should insert the"
+	echo "orphan MDT-object under .lustre/lost+found/MDTxxxx. But if"
+	echo "the MDT (on which the orphan MDT-object resides) has ever"
+	echo "failed to respond some name entry verification during the"
+	echo "first stage-scanning, then the LFSCK should skip to handle"
+	echo "orphan MDT-object on this MDT. But other MDTs should not"
+	echo "be affected."
+	echo "#####"
+
+	check_mount_and_prep
+	$LFS mkdir -i 0 $DIR/$tdir/d1
+	$LFS mkdir -i 1 $DIR/$tdir/d1/a1
+	$LFS mkdir -i 1 $DIR/$tdir/d1/a2
+
+	$LFS mkdir -i 1 $DIR/$tdir/d2
+	$LFS mkdir -i 0 $DIR/$tdir/d2/a1
+	$LFS mkdir -i 0 $DIR/$tdir/d2/a2
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "d1/a1's name entry will be removed, but the d1/a1's object"
+	echo "and its linkEA are kept in the system. And the case that"
+	echo "d2/a2's name entry will be removed, but the d2/a2's object"
+	echo "and its linkEA are kept in the system."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet mds1 $LCTL set_param fail_loc=0x1624
+	do_facet mds2 $LCTL set_param fail_loc=0x1624
+	rmdir $DIR/$tdir/d1/a1 || error "(1) Fail to rmdir $DIR/$tdir/d1/a1"
+	rmdir $DIR/$tdir/d2/a2 || error "(2) Fail to rmdir $DIR/$tdir/d2/a2"
+	do_facet mds1 $LCTL set_param fail_loc=0
+	do_facet mds2 $LCTL set_param fail_loc=0
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	echo "Inject failure, to simulate the MDT0 fail to handle"
+	echo "MDT1 LFSCK request during the first-stage scanning."
+	#define OBD_FAIL_LFSCK_BAD_NETWORK	0x161c
+	do_facet mds2 $LCTL set_param fail_loc=0x161c fail_val=0
+
+	echo "Trigger namespace LFSCK on all devices to find out orphan object"
+	$START_NAMESPACE -r -A ||
+		error "(3) Fail to start LFSCK for namespace"
+
+	wait_update_facet mds1 "$LCTL get_param -n \
+		mdd.$(facet_svc mds1).lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "partial" 32 || {
+		error "(4) mds1 is not the expected 'partial'"
+	}
+
+	wait_update_facet mds2 "$LCTL get_param -n \
+		mdd.$(facet_svc mds2).lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		error "(5) mds2 is not the expected 'completed'"
+	}
+
+	do_facet mds2 $LCTL set_param fail_loc=0 fail_val=0
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_namespace |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(6) Expect 0 fixed on mds1, but got: $repaired"
+
+	repaired=$(do_facet mds2 $LCTL get_param -n \
+		   mdd.$(facet_svc mds2).lfsck_namespace |
+		   awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Expect 1 fixed on mds2, but got: $repaired"
+
+	echo "Trigger namespace LFSCK on all devices again to cleanup"
+	$START_NAMESPACE -r -A ||
+		error "(8) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 9
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_namespace |
+			 awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(10) Expect 1 fixed on mds1, but got: $repaired"
+
+	repaired=$(do_facet mds2 $LCTL get_param -n \
+		   mdd.$(facet_svc mds2).lfsck_namespace |
+		   awk '/^lost_dirent_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(11) Expect 0 fixed on mds2, but got: $repaired"
+}
+run_test 28 "Skip the failed MDT(s) when handle orphan MDT-objects"
+
+test_29a() {
+	echo "#####"
+	echo "The object's nlink attribute is larger than the object's known"
+	echo "name entries count. The LFSCK will repair the object's nlink"
+	echo "attribute to match the known name entries count"
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	touch $DIR/$tdir/d0/foo || error "(2) Fail to create foo"
+
+	echo "Inject failure stub on MDT0 to simulate the case that foo's"
+	echo "nlink attribute is larger than its name entries count."
+
+	#define OBD_FAIL_LFSCK_MORE_NLINK	0x1625
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1625
+	ln $DIR/$tdir/d0/foo $DIR/$tdir/d0/h1 ||
+		error "(3) Fail to hard link to $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	cancel_lru_locks mdc
+	local count=$(stat --format=%h $DIR/$tdir/d0/foo)
+	[ $count -eq 3 ] || error "(4) Cannot inject error: $count"
+
+	echo "Trigger namespace LFSCK to repair the nlink count"
+	$START_NAMESPACE -r -A ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^nlinks_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair nlink count: $repaired"
+
+	cancel_lru_locks mdc
+	count=$(stat --format=%h $DIR/$tdir/d0/foo)
+	[ $count -eq 2 ] || error "(8) Fail to repair nlink count: $count"
+}
+# Disable 29a, we only allow nlink to be updated if the known linkEA
+# entries is larger than nlink count.
+#
+#run_test 29a "LFSCK can repair bad nlink count (1)"
+
+test_29b() {
+	echo "#####"
+	echo "The object's nlink attribute is smaller than the object's known"
+	echo "name entries count. The LFSCK will repair the object's nlink"
+	echo "attribute to match the known name entries count"
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/d0 || error "(1) Fail to mkdir d0"
+	touch $DIR/$tdir/d0/foo || error "(2) Fail to create foo"
+
+	echo "Inject failure stub on MDT0 to simulate the case that foo's"
+	echo "nlink attribute is smaller than its name entries count."
+
+	#define OBD_FAIL_LFSCK_LESS_NLINK	0x1626
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1626
+	ln $DIR/$tdir/d0/foo $DIR/$tdir/d0/h1 ||
+		error "(3) Fail to hard link to $DIR/$tdir/d0/foo"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	cancel_lru_locks mdc
+	local count=$(stat --format=%h $DIR/$tdir/d0/foo)
+	[ $count -eq 1 ] || error "(4) Cannot inject error: $count"
+
+	echo "Trigger namespace LFSCK to repair the nlink count"
+	$START_NAMESPACE -r -A ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^nlinks_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(7) Fail to repair nlink count: $repaired"
+
+	cancel_lru_locks mdc
+	count=$(stat --format=%h $DIR/$tdir/d0/foo)
+	[ $count -eq 2 ] || error "(8) Fail to repair nlink count: $count"
+}
+run_test 29b "LFSCK can repair bad nlink count (2)"
+
+test_29c()
+{
+	echo "#####"
+	echo "The namespace LFSCK will create many hard links to the target"
+	echo "file as to exceed the linkEA size limitation. Under such case"
+	echo "the linkEA will be marked as overflow that will prevent the"
+	echo "target file to be migrated. Then remove some hard links to"
+	echo "make the left hard links to be held within the linkEA size"
+	echo "limitation. But before the namespace LFSCK adding all the"
+	echo "missed linkEA entries back, the overflow mark (timestamp)"
+	echo "will not be cleared."
+	echo "#####"
+
+	check_mount_and_prep
+
+	mkdir -p $DIR/$tdir/guard || error "(0.1) Fail to mkdir"
+	$LFS mkdir -i $((MDSCOUNT - 1)) $DIR/$tdir/foo ||
+		error "(0.2) Fail to mkdir"
+	touch $DIR/$tdir/guard/f0 || error "(1) Fail to create"
+	local oldfid=$($LFS path2fid $DIR/$tdir/guard/f0)
+
+	# define MAX_LINKEA_SIZE        4096
+	# sizeof(link_ea_header) = 24
+	# sizeof(link_ea_entry) = 18
+	# nlink_min=$(((MAX_LINKEA_SIZE - sizeof(link_ea_header)) /
+	#	      (sizeof(link_ea_entry) + name_length))
+	# If the average name length is 12 bytes, then 150 hard links
+	# is totally enough to overflow the linkEA
+	echo "Create 150 hard links should succeed although the linkEA overflow"
+	createmany -l $DIR/$tdir/guard/f0 $DIR/$tdir/foo/ttttttttttt 150 ||
+		error "(2) Fail to hard link"
+
+	cancel_lru_locks mdc
+	if [ $MDSCOUNT -ge 2 ]; then
+		$LFS migrate -m 1 $DIR/$tdir/guard 2>/dev/null &&
+			error "(3.1) Migrate should fail"
+
+		echo "The object with linkEA overflow should NOT be migrated"
+		local newfid=$($LFS path2fid $DIR/$tdir/guard/f0)
+		[ "$newfid" == "$oldfid" ] ||
+			error "(3.2) Migrate should fail: $newfid != $oldfid"
+	fi
+
+	# Remove 100 hard links, then the linkEA should have space
+	# to hold the missed linkEA entries.
+	echo "Remove 100 hard links to save space for the missed linkEA entries"
+	unlinkmany $DIR/$tdir/foo/ttttttttttt 100 || error "(4) Fail to unlink"
+
+	if [ $MDSCOUNT -ge 2 ]; then
+		$LFS migrate -m 1 $DIR/$tdir/guard 2>/dev/null &&
+			error "(5.1) Migrate should fail"
+
+		# The overflow timestamp is still there, so migration will fail.
+		local newfid=$($LFS path2fid $DIR/$tdir/guard/f0)
+		[ "$newfid" == "$oldfid" ] ||
+			error "(5.2) Migrate should fail: $newfid != $oldfid"
+	fi
+
+	# sleep 3 seconds to guarantee that the overflow is recognized
+	sleep 3
+
+	echo "Trigger namespace LFSCK to clear the overflow timestamp"
+	$START_NAMESPACE -r -A ||
+		error "(6) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 7
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^linkea_overflow_cleared/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(8) Fail to clear linkea overflow: $repaired"
+
+	repaired=$($SHOW_NAMESPACE |
+		   awk '/^nlinks_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(9) Unexpected nlink repaired: $repaired"
+
+	if [ $MDSCOUNT -ge 2 ]; then
+		$LFS migrate -m 1 $DIR/$tdir/guard 2>/dev/null ||
+			error "(10.1) Migrate failure"
+
+		# Migration should succeed after clear the overflow timestamp.
+		local newfid=$($LFS path2fid $DIR/$tdir/guard/f0)
+		[ "$newfid" != "$oldfid" ] ||
+			error "(10.2) Migrate should succeed"
+
+		ls -l $DIR/$tdir/foo > /dev/null ||
+			error "(11) 'ls' failed after migration"
+	fi
+
+	rm -f $DIR/$tdir/guard/f0 || error "(12) Fail to unlink f0"
+	rm -rf $DIR/$tdir/foo || error "(13) Fail to rmdir foo"
+}
+run_test 29c "verify linkEA size limitation"
+
+test_30() {
+	[ $(facet_fstype $SINGLEMDS) != ldiskfs ] &&
+		skip "ldiskfs only test" && return
+	[ -n "$FILESET" ] && skip "Not functional for FILESET set"
+
+	echo "#####"
+	echo "The namespace LFSCK will move the orphans from backend"
+	echo "/lost+found directory to normal client visible namespace"
+	echo "or to global visible ./lustre/lost+found/MDTxxxx/ directory"
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $DIR/$tdir/foo || error "(1) Fail to mkdir foo"
+	touch $DIR/$tdir/foo/f0 || error "(2) Fail to touch f1"
+
+	echo "Inject failure stub on MDT0 to simulate the case that"
+	echo "directory d0 has no linkEA entry, then the LFSCK will"
+	echo "move it into .lustre/lost+found/MDTxxxx/ later."
+
+	#define OBD_FAIL_LFSCK_NO_LINKEA	0x161d
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x161d
+	mkdir $DIR/$tdir/foo/d0 || error "(3) Fail to mkdir d0"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	local pfid=$($LFS path2fid $DIR/$tdir/foo)
+	local cfid=$($LFS path2fid $DIR/$tdir/foo/d0)
+
+	touch $DIR/$tdir/foo/d0/f1 || error "(4) Fail to touch f1"
+	mkdir $DIR/$tdir/foo/d0/d1 || error "(5) Fail to mkdir d1"
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "object's name entry will be removed, but not destroy the"
+	echo "object. Then backend e2fsck will handle it as orphan and"
+	echo "add them into the backend /lost+found directory."
+
+	#define OBD_FAIL_LFSCK_NO_NAMEENTRY	0x1624
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1624
+	rmdir $DIR/$tdir/foo/d0/d1 || error "(6) Fail to rmdir d1"
+	rm -f $DIR/$tdir/foo/d0/f1 || error "(7) Fail to unlink f1"
+	rmdir $DIR/$tdir/foo/d0 || error "(8) Fail to rmdir d0"
+	rm -f $DIR/$tdir/foo/f0 || error "(9) Fail to unlink f0"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	umount_client $MOUNT || error "(10) Fail to stop client!"
+
+	stop $SINGLEMDS || error "(11) Fail to stop MDT0"
+
+	echo "run e2fsck"
+	run_e2fsck $(facet_host $SINGLEMDS) $MDT_DEVNAME "-y" ||
+		error "(12) Fail to run e2fsck"
+
+	start $SINGLEMDS $MDT_DEVNAME $MOUNT_OPTS_NOSCRUB > /dev/null ||
+		error "(13) Fail to start MDT0"
+
+	echo "Trigger namespace LFSCK to recover backend orphans"
+	$START_NAMESPACE -r -A ||
+		error "(14) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 15
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^local_lost_found_moved/ { print $2 }')
+	[ $repaired -ge 4 ] ||
+		error "(16) Fail to recover backend orphans: $repaired"
+
+	mount_client $MOUNT || error "(17) Fail to start client!"
+
+	stat $DIR/$tdir/foo/f0 || error "(18) f0 is not recovered"
+
+	ls -ail $MOUNT/.lustre/lost+found/
+
+	echo "d0 should become orphan under .lustre/lost+found/MDT0000/"
+	[ -d $MOUNT/.lustre/lost+found/MDT0000 ] ||
+		error "(19) $MOUNT/.lustre/lost+found/MDT0000/ should be there"
+
+	ls -ail $MOUNT/.lustre/lost+found/MDT0000/
+
+	local cname=$MOUNT/.lustre/lost+found/MDT0000/${cfid}-${pfid}-D-0
+	[ ! -z "$cname" ] || error "(20) d0 is not recovered"
+
+	stat ${cname}/d1 || error "(21) d1 is not recovered"
+	stat ${cname}/f1 || error "(22) f1 is not recovered"
+}
+run_test 30 "LFSCK can recover the orphans from backend /lost+found"
+
+test_31a() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For the name entry under a striped directory, if the name"
+	echo "hash does not match the shard, then the LFSCK will repair"
+	echo "the bad name entry"
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+
+	echo "Inject failure stub on client to simulate the case that"
+	echo "some name entry should be inserted into other non-first"
+	echo "shard, but inserted into the first shard by wrong"
+
+	#define OBD_FAIL_LFSCK_BAD_NAME_HASH	0x1628
+	$LCTL set_param fail_loc=0x1628 fail_val=0
+	createmany -d $DIR/$tdir/striped_dir/d $MDSCOUNT ||
+		error "(2) Fail to create file under striped directory"
+	$LCTL set_param fail_loc=0 fail_val=0
+
+	echo "Trigger namespace LFSCK to repair bad name hash"
+	$START_NAMESPACE -r -A ||
+		error "(3) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 4
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^name_hash_repaired/ { print $2 }')
+	[ $repaired -ge 1 ] ||
+		error "(5) Fail to repair bad name hash: $repaired"
+
+	umount_client $MOUNT || error "(6) umount failed"
+	mount_client $MOUNT || error "(7) mount failed"
+
+	for ((i = 0; i < $MDSCOUNT; i++)); do
+		stat $DIR/$tdir/striped_dir/d$i ||
+			error "(8) Fail to stat d$i after LFSCK"
+		rmdir $DIR/$tdir/striped_dir/d$i ||
+			error "(9) Fail to unlink d$i after LFSCK"
+	done
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(10) Fail to remove the striped directory after LFSCK"
+}
+run_test 31a "The LFSCK can find/repair the name entry with bad name hash (1)"
+
+test_31b() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For the name entry under a striped directory, if the name"
+	echo "hash does not match the shard, then the LFSCK will repair"
+	echo "the bad name entry"
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+
+	echo "Inject failure stub on client to simulate the case that"
+	echo "some name entry should be inserted into other non-second"
+	echo "shard, but inserted into the secod shard by wrong"
+
+	#define OBD_FAIL_LFSCK_BAD_NAME_HASH	0x1628
+	$LCTL set_param fail_loc=0x1628 fail_val=1
+	createmany -d $DIR/$tdir/striped_dir/d $MDSCOUNT ||
+		error "(2) Fail to create file under striped directory"
+	$LCTL set_param fail_loc=0 fail_val=0
+
+	echo "Trigger namespace LFSCK to repair bad name hash"
+	$START_NAMESPACE -r -A ||
+		error "(3) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 4
+
+	local repaired=$(do_facet mds2 $LCTL get_param -n \
+			 mdd.$(facet_svc mds2).lfsck_namespace |
+			 awk '/^name_hash_repaired/ { print $2 }')
+	[ $repaired -ge 1 ] ||
+		error "(5) Fail to repair bad name hash: $repaired"
+
+	umount_client $MOUNT || error "(6) umount failed"
+	mount_client $MOUNT || error "(7) mount failed"
+
+	for ((i = 0; i < $MDSCOUNT; i++)); do
+		stat $DIR/$tdir/striped_dir/d$i ||
+			error "(8) Fail to stat d$i after LFSCK"
+		rmdir $DIR/$tdir/striped_dir/d$i ||
+			error "(9) Fail to unlink d$i after LFSCK"
+	done
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(10) Fail to remove the striped directory after LFSCK"
+}
+run_test 31b "The LFSCK can find/repair the name entry with bad name hash (2)"
+
+test_31c() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the master MDT-object of the striped directory"
+	echo "may lost its master LMV EA. If nobody created files under the"
+	echo "master directly after the master LMV EA lost, then the LFSCK"
+	echo "should re-generate the master LMV EA."
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "master MDT-object of the striped directory lost the LMV EA."
+
+	#define OBD_FAIL_LFSCK_LOST_MASTER_LMV	0x1629
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1629
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+
+	echo "Trigger namespace LFSCK to re-generate master LMV EA"
+	$START_NAMESPACE -r -A ||
+		error "(2) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 3
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^striped_dirs_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to re-generate master LMV EA: $repaired"
+
+	umount_client $MOUNT || error "(5) umount failed"
+	mount_client $MOUNT || error "(6) mount failed"
+
+	local empty=$(ls $DIR/$tdir/striped_dir/)
+	[ -z "$empty" ] || error "(7) The master LMV EA is not repaired: $empty"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(8) Fail to remove the striped directory after LFSCK"
+}
+run_test 31c "Re-generate the lost master LMV EA for striped directory"
+
+test_31d() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the master MDT-object of the striped directory"
+	echo "may lost its master LMV EA. If somebody created files under the"
+	echo "master directly after the master LMV EA lost, then the LFSCK"
+	echo "should NOT re-generate the master LMV EA, instead, it should"
+	echo "change the broken striped dirctory as read-only to prevent"
+	echo "further damage"
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "master MDT-object of the striped directory lost the LMV EA."
+
+	#define OBD_FAIL_LFSCK_LOST_MASTER_LMV	0x1629
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1629
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x0
+
+	umount_client $MOUNT || error "(2) umount failed"
+	mount_client $MOUNT || error "(3) mount failed"
+
+	touch $DIR/$tdir/striped_dir/dummy ||
+		error "(4) Fail to touch under broken striped directory"
+
+	echo "Trigger namespace LFSCK to find out the inconsistency"
+	$START_NAMESPACE -r -A ||
+		error "(5) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 6
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^striped_dirs_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(7) Re-generate master LMV EA unexpected: $repaired"
+
+	stat $DIR/$tdir/striped_dir/dummy ||
+		error "(8) Fail to stat $DIR/$tdir/striped_dir/dummy"
+
+	touch $DIR/$tdir/striped_dir/foo &&
+		error "(9) The broken striped directory should be read-only"
+
+	chattr -i $DIR/$tdir/striped_dir ||
+		error "(10) Fail to chattr on the broken striped directory"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(11) Fail to remove the striped directory after LFSCK"
+}
+run_test 31d "Set broken striped directory (modified after broken) as read-only"
+
+test_31e() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the slave MDT-object of the striped directory"
+	echo "may lost its slave LMV EA. The LFSCK should re-generate the"
+	echo "slave LMV EA."
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "slave MDT-object (that resides on the same MDT as the master"
+	echo "MDT-object resides on) lost the LMV EA."
+
+	#define OBD_FAIL_LFSCK_LOST_SLAVE_LMV	0x162a
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x162a fail_val=0
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x0 fail_val=0
+
+	echo "Trigger namespace LFSCK to re-generate slave LMV EA"
+	$START_NAMESPACE -r -A ||
+		error "(2) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 3
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^striped_shards_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to re-generate slave LMV EA: $repaired"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(5) Fail to remove the striped directory after LFSCK"
+}
+run_test 31e "Re-generate the lost slave LMV EA for striped directory (1)"
+
+test_31f() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the slave MDT-object of the striped directory"
+	echo "may lost its slave LMV EA. The LFSCK should re-generate the"
+	echo "slave LMV EA."
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "slave MDT-object (that resides on different MDT as the master"
+	echo "MDT-object resides on) lost the LMV EA."
+
+	#define OBD_FAIL_LFSCK_LOST_SLAVE_LMV	0x162a
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x162a fail_val=1
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x0 fail_val=0
+
+	echo "Trigger namespace LFSCK to re-generate slave LMV EA"
+	$START_NAMESPACE -r -A ||
+		error "(2) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 3
+
+	local repaired=$(do_facet mds2 $LCTL get_param -n \
+			 mdd.$(facet_svc mds2).lfsck_namespace |
+			 awk '/^striped_shards_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to re-generate slave LMV EA: $repaired"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(5) Fail to remove the striped directory after LFSCK"
+}
+run_test 31f "Re-generate the lost slave LMV EA for striped directory (2)"
+
+test_31g() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the stripe index in the slave LMV EA is"
+	echo "corrupted. The LFSCK should repair the slave LMV EA."
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "slave LMV EA on the first shard of the striped directory"
+	echo "claims the same index as the second shard claims"
+
+	#define OBD_FAIL_LFSCK_BAD_SLAVE_LMV	0x162b
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x162b fail_val=0
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x0 fail_val=0
+
+	echo "Trigger namespace LFSCK to repair the slave LMV EA"
+	$START_NAMESPACE -r -A ||
+		error "(2) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 3
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^striped_shards_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to repair slave LMV EA: $repaired"
+
+	umount_client $MOUNT || error "(5) umount failed"
+	mount_client $MOUNT || error "(6) mount failed"
+
+	touch $DIR/$tdir/striped_dir/foo ||
+		error "(7) Fail to touch file after the LFSCK"
+
+	rm -f $DIR/$tdir/striped_dir/foo ||
+		error "(8) Fail to unlink file after the LFSCK"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(9) Fail to remove the striped directory after LFSCK"
+}
+run_test 31g "Repair the corrupted slave LMV EA"
+
+test_31h() {
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	echo "#####"
+	echo "For some reason, the shard's name entry in the striped"
+	echo "directory may be corrupted. The LFSCK should repair the"
+	echo "bad shard's name entry."
+	echo "#####"
+
+	check_mount_and_prep
+
+	echo "Inject failure stub on MDT0 to simulate the case that the"
+	echo "first shard's name entry in the striped directory claims"
+	echo "the same index as the second shard's name entry claims."
+
+	#define OBD_FAIL_LFSCK_BAD_SLAVE_NAME	0x162c
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x162c fail_val=0
+	$LFS setdirstripe -i 0 -c $MDSCOUNT $DIR/$tdir/striped_dir ||
+		error "(1) Fail to create striped directory"
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x0 fail_val=0
+
+	echo "Trigger namespace LFSCK to repair the shard's name entry"
+	$START_NAMESPACE -r -A ||
+		error "(2) Fail to start LFSCK for namespace"
+
+	wait_all_targets_blocked namespace completed 3
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to repair shard's name entry: $repaired"
+
+	umount_client $MOUNT || error "(5) umount failed"
+	mount_client $MOUNT || error "(6) mount failed"
+
+	touch $DIR/$tdir/striped_dir/foo ||
+		error "(7) Fail to touch file after the LFSCK"
+
+	rm -f $DIR/$tdir/striped_dir/foo ||
+		error "(8) Fail to unlink file after the LFSCK"
+
+	rmdir $DIR/$tdir/striped_dir ||
+		error "(9) Fail to remove the striped directory after LFSCK"
+}
+run_test 31h "Repair the corrupted shard's name entry"
+
+test_32a()
+{
+	lfsck_prep 5 5
+	umount_client $MOUNT
+
+	#define OBD_FAIL_LFSCK_ENGINE_DELAY	0x162d
+	do_facet $SINGLEMDS $LCTL set_param fail_val=3 fail_loc=0x162d
+	$START_LAYOUT -r || error "(1) Fail to start LFSCK for layout!"
+
+	local STATUS=$($SHOW_LAYOUT | awk '/^status/ { print $2 }')
+	[ "$STATUS" == "scanning-phase1" ] ||
+		error "(2) Expect 'scanning-phase1', but got '$STATUS'"
+
+	echo "stop ost1"
+	stop ost1 > /dev/null || error "(3) Fail to stop OST1!"
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
+	sleep 4
+
+	echo "stop LFSCK"
+	$STOP_LFSCK || error "(4) Fail to stop LFSCK!"
+
+	start ost1 $(ostdevname 1) $MOUNT_OPTS_NOSCRUB > /dev/null ||
+		error "(5) Fail to start ost1"
+}
+run_test 32a "stop LFSCK when some OST failed"
+
+test_32b()
+{
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	lfsck_prep 5 5
+	$LFS mkdir -i 1 $DIR/$tdir/dp ||
+		error "(1) Fail to create $DIR/$tdir/dp"
+	$LFS mkdir -i 0 -c $MDSCOUNT $DIR/$tdir/dp/dc1 ||
+		error "(2) Fail to create $DIR/$tdir/dp/dc1"
+	$LFS mkdir -i 0 -c $MDSCOUNT $DIR/$tdir/dp/dc2 ||
+		error "(3) Fail to create $DIR/$tdir/dp/dc2"
+	umount_client $MOUNT
+
+	#define OBD_FAIL_LFSCK_ENGINE_DELAY	0x162d
+	do_facet $SINGLEMDS $LCTL set_param fail_val=3 fail_loc=0x162d
+	$START_NAMESPACE -r -A || error "(4) Fail to start LFSCK for namespace!"
+
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "scanning-phase1" 32 || {
+		$SHOW_NAMESPACE
+		error "(5) unexpected status"
+	}
+
+	echo "stop mds2"
+	stop mds2 > /dev/null || error "(6) Fail to stop MDT2!"
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0 fail_val=0
+	sleep 4
+
+	echo "stop LFSCK"
+	$STOP_LFSCK || error "(7) Fail to stop LFSCK!"
+
+	start mds2 $(mdsdevname 2) $MOUNT_OPTS_NOSCRUB > /dev/null ||
+		error "(8) Fail to start MDT2"
+}
+run_test 32b "stop LFSCK when some MDT failed"
+
+test_33()
+{
+	lfsck_prep 5 5
+
+	$START_LAYOUT --dryrun -o -r ||
+		error "(1) Fail to start layout LFSCK"
+	wait_all_targets_blocked layout completed 2
+
+	local PARAMS=$($SHOW_LAYOUT | awk '/^param/ { print $2 }')
+	[ "$PARAMS" == "dryrun,all_targets,orphan" ] ||
+		error "(3) Expect 'dryrun,all_targets,orphan', got '$PARAMS'"
+
+	$START_NAMESPACE -e abort -A -r ||
+		error "(4) Fail to start namespace LFSCK"
+	wait_all_targets_blocked namespace completed 5
+
+	PARAMS=$($SHOW_NAMESPACE | awk '/^param/ { print $2 }')
+	[ "$PARAMS" == "failout,all_targets" ] ||
+		error "(6) Expect 'failout,all_targets', got '$PARAMS'"
+}
+run_test 33 "check LFSCK paramters"
+
+test_34()
+{
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+	[ $(facet_fstype $SINGLEMDS) != zfs ] &&
+		skip "Only valid for ZFS backend" && return
+
+	lfsck_prep 1 1
+
+	#define OBD_FAIL_LFSCK_NO_AGENTOBJ	0x1630
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0x1630
+	$LFS mkdir -i 1 $DIR/$tdir/dummy ||
+		error "(1) Fail to create $DIR/$tdir/dummy"
+
+	do_facet $SINGLEMDS $LCTL set_param fail_loc=0
+	$START_NAMESPACE -r || error "(2) Fail to start LFSCK for namespace!"
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(3) unexpected status"
+	}
+
+	local repaired=$($SHOW_NAMESPACE |
+			 awk '/^dirent_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to repair the lost agent object: $repaired"
+
+	$START_NAMESPACE -r || error "(5) Fail to start LFSCK for namespace!"
+	wait_update_facet $SINGLEMDS "$LCTL get_param -n \
+		mdd.${MDT_DEV}.lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" 32 || {
+		$SHOW_NAMESPACE
+		error "(6) unexpected status"
+	}
+
+	repaired=$($SHOW_NAMESPACE | awk '/^dirent_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(7) Unexpected repairing: $repaired"
+}
+run_test 34 "LFSCK can rebuild the lost agent object"
+
+test_35()
+{
+	[ $MDSCOUNT -lt 2 ] && skip "needs >= 2 MDTs" && return
+
+	lfsck_prep 1 1
+
+	#define OBD_FAIL_LFSCK_NO_AGENTENT	0x1631
+	do_facet mds2 $LCTL set_param fail_loc=0x1631
+	$LFS mkdir -i 1 $DIR/$tdir/dummy ||
+		error "(1) Fail to create $DIR/$tdir/dummy"
+
+	sync; sleep 3
+	do_facet mds2 $LCTL set_param fail_loc=0
+	$START_NAMESPACE -A -r || error "(2) Fail to start LFSCK for namespace!"
+	wait_update_facet mds2 "$LCTL get_param -n \
+		mdd.$(facet_svc mds2).lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
+		error "(3) MDS${k} is not the expected 'completed'"
+
+	local repaired=$(do_facet mds2 $LCTL get_param -n \
+			 mdd.$(facet_svc mds2).lfsck_namespace |
+			 awk '/^agent_entries_repaired/ { print $2 }')
+	[ $repaired -eq 1 ] ||
+		error "(4) Fail to repair the lost agent entry: $repaired"
+
+	echo "stopall to cleanup object cache"
+	stopall > /dev/null
+	echo "setupall"
+	setupall > /dev/null
+
+	$START_NAMESPACE -A -r || error "(5) Fail to start LFSCK for namespace!"
+	wait_update_facet mds2 "$LCTL get_param -n \
+		mdd.$(facet_svc mds2).lfsck_namespace |
+		awk '/^status/ { print \\\$2 }'" "completed" $LTIME ||
+		error "(6) MDS${k} is not the expected 'completed'"
+
+	repaired=$(do_facet mds2 $LCTL get_param -n \
+		   mdd.$(facet_svc mds2).lfsck_namespace |
+		   awk '/^agent_entries_repaired/ { print $2 }')
+	[ $repaired -eq 0 ] ||
+		error "(7) Unexpected repairing: $repaired"
+}
+run_test 35 "LFSCK can rebuild the lost agent entry"
+
+test_36a() {
+	[ $OSTCOUNT -lt 3 ] && skip "needs >= 3 OSTs" && return
+
+	echo "#####"
+	echo "The target MDT-object's LOV EA corrupted as to lose one of the "
+	echo "mirrors information. The layout LFSCK should rebuild the LOV EA "
+	echo "with the PFID EA of related OST-object(s) belong to the mirror."
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setstripe -N -E 1M -o 0,1 -E -1 -o 2 -N -E 2M -o 1,2 -E -1 -o 0 \
+		-N -E 3M -o 2,0 -E -1 -o 1 $DIR/$tdir/f0 ||
+		error "(0) Fail to create mirror file $DIR/$tdir/f0"
+	$LFS setstripe -N -E 1M -o 0,1 -E -1 -o 2 -N -E 2M -o 1,2 -E -1 -o 0 \
+		-N -E 3M -o 2,0 -E -1 -o 1 $DIR/$tdir/f1 ||
+		error "(1) Fail to create mirror file $DIR/$tdir/f1"
+	$LFS setstripe -N -E 1M -o 0,1 -E -1 -o 2 -N -E 2M -o 1,2 -E -1 -o 0 \
+		-N -E 3M -o 2,0 -E -1 -o 1 $DIR/$tdir/f2 ||
+		error "(2) Fail to create mirror file $DIR/$tdir/f2"
+
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=4 ||
+		error "(3) Fail to write $DIR/$tdir/f0"
+	dd if=/dev/zero of=$DIR/$tdir/f1 bs=1M count=4 ||
+		error "(4) Fail to write $DIR/$tdir/f1"
+	dd if=/dev/zero of=$DIR/$tdir/f2 bs=1M count=4 ||
+		error "(5) Fail to write $DIR/$tdir/f2"
+
+	$LFS mirror resync $DIR/$tdir/f0 ||
+		error "(6) Fail to resync $DIR/$tdir/f0"
+	$LFS mirror resync $DIR/$tdir/f1 ||
+		error "(7) Fail to resync $DIR/$tdir/f1"
+	$LFS mirror resync $DIR/$tdir/f2 ||
+		error "(8) Fail to resync $DIR/$tdir/f2"
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	$LFS getstripe $DIR/$tdir/f0 ||
+		error "(9) Fail to getstripe for $DIR/$tdir/f0"
+	$LFS getstripe $DIR/$tdir/f1 ||
+		error "(10) Fail to getstripe for $DIR/$tdir/f1"
+	$LFS getstripe $DIR/$tdir/f2 ||
+		error "(11) Fail to getstripe for $DIR/$tdir/f2"
+
+	echo "Inject failure, to simulate the case of missing one mirror in LOV"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
+	do_facet mds1 $LCTL set_param fail_loc=0x1616
+
+	$LFS mirror split --mirror-id 1 -d $DIR/$tdir/f0 ||
+		error "(12) Fail to split 1st mirror from $DIR/$tdir/f0"
+	$LFS mirror split --mirror-id 2 -d $DIR/$tdir/f1 ||
+		error "(13) Fail to split 2nd mirror from $DIR/$tdir/f1"
+	$LFS mirror split --mirror-id 3 -d $DIR/$tdir/f2 ||
+		error "(14) Fail to split 3rd mirror from $DIR/$tdir/f2"
+
+	sync
+	sleep 2
+	do_facet mds1 $LCTL set_param fail_loc=0
+
+	$LFS getstripe $DIR/$tdir/f0 | grep "lcme_mirror_id:.*1" &&
+		error "(15) The 1st of mirror is not destroyed"
+	$LFS getstripe $DIR/$tdir/f1 | grep "lcme_mirror_id:.*2" &&
+		error "(16) The 2nd of mirror is not destroyed"
+	$LFS getstripe $DIR/$tdir/f2 | grep "lcme_mirror_id:.*3" &&
+		error "(17) The 3rd of mirror is not destroyed"
+
+	local mirrors
+
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f0)
+	[ $mirrors -eq 2 ] || error "(18) $DIR/$tdir/f0 has $mirrors mirrors"
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f1)
+	[ $mirrors -eq 2 ] || error "(19) $DIR/$tdir/f1 has $mirrors mirrors"
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f2)
+	[ $mirrors -eq 2 ] || error "(20) $DIR/$tdir/f2 has $mirrors mirrors"
+
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(21) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			error "(22) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		local cur_status=$(do_facet ost${k} $LCTL get_param -n \
+				obdfilter.$(facet_svc ost${k}).lfsck_layout |
+				awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(23) OST${k} Expect 'completed', but got '$cur_status'"
+	done
+
+	local repaired=$(do_facet mds1 $LCTL get_param -n \
+			 mdd.$(facet_svc mds1).lfsck_layout |
+			 awk '/^repaired_orphan/ { print $2 }')
+	[ $repaired -eq 9 ] ||
+		error "(24) Expect 9 fixed on mds1, but got: $repaired"
+
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f0)
+	[ $mirrors -eq 3 ] || error "(25) $DIR/$tdir/f0 has $mirrors mirrors"
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f1)
+	[ $mirrors -eq 3 ] || error "(26) $DIR/$tdir/f1 has $mirrors mirrors"
+	mirrors=$($LFS getstripe -N $DIR/$tdir/f2)
+	[ $mirrors -eq 3 ] || error "(27) $DIR/$tdir/f2 has $mirrors mirrors"
+
+	$LFS getstripe $DIR/$tdir/f0 | grep "lcme_mirror_id:.*1" || {
+		$LFS getstripe $DIR/$tdir/f0
+		error "(28) The 1st of mirror is not recovered"
+	}
+
+	$LFS getstripe $DIR/$tdir/f1 | grep "lcme_mirror_id:.*2" || {
+		$LFS getstripe $DIR/$tdir/f1
+		error "(29) The 2nd of mirror is not recovered"
+	}
+
+	$LFS getstripe $DIR/$tdir/f2 | grep "lcme_mirror_id:.*3" || {
+		$LFS getstripe $DIR/$tdir/f2
+		error "(30) The 3rd of mirror is not recovered"
+	}
+}
+run_test 36a "rebuild LOV EA for mirrored file (1)"
+
+test_36b() {
+	[ $OSTCOUNT -lt 3 ] && skip "needs >= 3 OSTs" && return
+
+	echo "#####"
+	echo "The mirrored file lost its MDT-object, but relatd OST-objects "
+	echo "are still there. The layout LFSCK should rebuild the LOV EA "
+	echo "with the PFID EA of related OST-object(s) belong to the file. "
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setstripe -N -E 1M -o 0,1 -E -1 -o 2 -N -E 2M -o 1,2 -E -1 -o 0 \
+		-N -E 3M -o 2,0 -E -1 -o 1 $DIR/$tdir/f0 ||
+		error "(0) Fail to create mirror file $DIR/$tdir/f0"
+
+	local fid=$($LFS path2fid $DIR/$tdir/f0)
+
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=4 ||
+		error "(1) Fail to write $DIR/$tdir/f0"
+	$LFS mirror resync $DIR/$tdir/f0 ||
+		error "(2) Fail to resync $DIR/$tdir/f0"
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	$LFS getstripe $DIR/$tdir/f0 ||
+		error "(3) Fail to getstripe for $DIR/$tdir/f0"
+
+	echo "Inject failure, to simulate the case of missing the MDT-object"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
+	do_facet mds1 $LCTL set_param fail_loc=0x1616
+	rm -f $DIR/$tdir/f0 || error "(4) Fail to remove $DIR/$tdir/f0"
+
+	sync
+	sleep 2
+	do_facet mds1 $LCTL set_param fail_loc=0
+
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(5) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			error "(6) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		local cur_status=$(do_facet ost${k} $LCTL get_param -n \
+				obdfilter.$(facet_svc ost${k}).lfsck_layout |
+				awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(7) OST${k} Expect 'completed', but got '$cur_status'"
+	done
+
+	local count=$(do_facet mds1 $LCTL get_param -n \
+		      mdd.$(facet_svc mds1).lfsck_layout |
+		      awk '/^repaired_orphan/ { print $2 }')
+	[ $count -eq 9 ] || error "(8) Expect 9 fixed on mds1, but got: $count"
+
+	local name=$MOUNT/.lustre/lost+found/MDT0000/${fid}-R-0
+	count=$($LFS getstripe --mirror-count $name)
+	[ $count -eq 3 ] || error "(9) $DIR/$tdir/f0 has $count mirrors"
+
+	count=$($LFS getstripe --component-count $name)
+	[ $count -eq 6 ] || error "(10) $DIR/$tdir/f0 has $count components"
+
+	$LFS getstripe $name | grep "lcme_mirror_id:.*1" || {
+		$LFS getstripe $name
+		error "(11) The 1st of mirror is not recovered"
+	}
+
+	$LFS getstripe $name | grep "lcme_mirror_id:.*2" || {
+		$LFS getstripe $name
+		error "(12) The 2nd of mirror is not recovered"
+	}
+
+	$LFS getstripe $name | grep "lcme_mirror_id:.*3" || {
+		$LFS getstripe $name
+		error "(13) The 3rd of mirror is not recovered"
+	}
+}
+run_test 36b "rebuild LOV EA for mirrored file (2)"
+
+test_36c() {
+	[ $OSTCOUNT -lt 3 ] && skip "needs >= 3 OSTs" && return
+
+	echo "#####"
+	echo "The mirrored file has been modified, not resynced yet, then "
+	echo "lost its MDT-object, but relatd OST-objects are still there. "
+	echo "The layout LFSCK should rebuild the LOV EA and relatd status "
+	echo "with the PFID EA of related OST-object(s) belong to the file. "
+	echo "#####"
+
+	check_mount_and_prep
+
+	$LFS setstripe -N -E 1M -o 0,1 -E -1 -o 2 -N -E 2M -o 1,2 -E -1 -o 0 \
+		$DIR/$tdir/f0 ||
+		error "(0) Fail to create mirror file $DIR/$tdir/f0"
+
+	local fid=$($LFS path2fid $DIR/$tdir/f0)
+
+	# The 1st dd && resync makes all related OST-objects have been written
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=4 ||
+		error "(1.1) Fail to write $DIR/$tdir/f0"
+	$LFS mirror resync $DIR/$tdir/f0 ||
+		error "(1.2) Fail to resync $DIR/$tdir/f0"
+	# The 2nd dd makes one mirror to be stale
+	dd if=/dev/zero of=$DIR/$tdir/f0 bs=1M count=4 ||
+		error "(1.3) Fail to write $DIR/$tdir/f0"
+
+	cancel_lru_locks mdc
+	cancel_lru_locks osc
+
+	$LFS getstripe $DIR/$tdir/f0 ||
+		error "(2) Fail to getstripe for $DIR/$tdir/f0"
+
+	local saved_flags1=$($LFS getstripe $DIR/$tdir/f0 | head -n 10 |
+			     awk '/lcme_flags/ { print $2 }')
+	local saved_flags2=$($LFS getstripe $DIR/$tdir/f0 | tail -n 10 |
+			     awk '/lcme_flags/ { print $2 }')
+
+	echo "Inject failure, to simulate the case of missing the MDT-object"
+	#define OBD_FAIL_LFSCK_LOST_MDTOBJ	0x1616
+	do_facet mds1 $LCTL set_param fail_loc=0x1616
+	rm -f $DIR/$tdir/f0 || error "(3) Fail to remove $DIR/$tdir/f0"
+
+	sync
+	sleep 2
+	do_facet mds1 $LCTL set_param fail_loc=0
+
+	echo "Trigger layout LFSCK on all devices to find out orphan OST-object"
+	$START_LAYOUT -r -o || error "(4) Fail to start LFSCK for layout!"
+
+	for k in $(seq $MDSCOUNT); do
+		# The LFSCK status query internal is 30 seconds. For the case
+		# of some LFSCK_NOTIFY RPCs failure/lost, we will wait enough
+		# time to guarantee the status sync up.
+		wait_update_facet mds${k} "$LCTL get_param -n \
+			mdd.$(facet_svc mds${k}).lfsck_layout |
+			awk '/^status/ { print \\\$2 }'" "completed" 32 ||
+			error "(5) MDS${k} is not the expected 'completed'"
+	done
+
+	for k in $(seq $OSTCOUNT); do
+		local cur_status=$(do_facet ost${k} $LCTL get_param -n \
+				obdfilter.$(facet_svc ost${k}).lfsck_layout |
+				awk '/^status/ { print $2 }')
+		[ "$cur_status" == "completed" ] ||
+		error "(6) OST${k} Expect 'completed', but got '$cur_status'"
+	done
+
+	local count=$(do_facet mds1 $LCTL get_param -n \
+		      mdd.$(facet_svc mds1).lfsck_layout |
+		      awk '/^repaired_orphan/ { print $2 }')
+	[ $count -eq 6 ] || error "(7) Expect 9 fixed on mds1, but got: $count"
+
+	local name=$MOUNT/.lustre/lost+found/MDT0000/${fid}-R-0
+	count=$($LFS getstripe --mirror-count $name)
+	[ $count -eq 2 ] || error "(8) $DIR/$tdir/f0 has $count mirrors"
+
+	count=$($LFS getstripe --component-count $name)
+	[ $count -eq 4 ] || error "(9) $DIR/$tdir/f0 has $count components"
+
+	local flags=$($LFS getstripe $name | head -n 10 |
+		awk '/lcme_flags/ { print $2 }')
+	[ "$flags" == "$saved_flags1" ] || {
+		$LFS getstripe $name
+		error "(10) expect flags $saved_flags1, got $flags"
+	}
+
+	flags=$($LFS getstripe $name | tail -n 10 |
+		awk '/lcme_flags/ { print $2 }')
+	[ "$flags" == "$saved_flags2" ] || {
+		$LFS getstripe $name
+		error "(11) expect flags $saved_flags2, got $flags"
+	}
+}
+run_test 36c "rebuild LOV EA for mirrored file (3)"
+
+test_37()
+{
+	local PID
+	local rc
+	local t_dir="$DIR/$tdir/d0"
+	check_mount_and_prep
+
+	$LFS mkdir -i 0 $t_dir || error "(2) Fail to mkdir $t_dir on MDT0"
+	multiop_bg_pause $t_dir D_c || { error "multiop failed: $?"; return 1; }
+	PID=$!
+	rmdir $t_dir
+
+	$START_NAMESPACE -r -A || {
+	    error "(3) Fail to start LFSCK for namespace!"; kill -USR1 $PID; }
+
+	wait_all_targets_blocked namespace completed 4
+	stat $t_dir && rc=1
+	kill -USR1 $PID
+	return $rc
+}
+run_test 37 "LFSCK must skip a ORPHAN"
 
-$LCTL set_param debug=-lfsck > /dev/null || true
 
 # restore MDS/OST size
 MDSSIZE=${SAVED_MDSSIZE}
@@ -2440,7 +5578,8 @@ OSTSIZE=${SAVED_OSTSIZE}
 OSTCOUNT=${SAVED_OSTCOUNT}
 
 # cleanup the system at last
-formatall
+REFORMAT="yes" cleanup_and_setup_lustre
 
 complete $SECONDS
+check_and_cleanup_lustre
 exit_status