xfs: test that the needsrepair feature works as advertised

Make sure that the needsrepair feature flag can be cleared only by
repair and that mounts are prohibited when the feature is set.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

common/xfs

@@ -312,6 +312,14 @@ _scratch_xfs_check()
 	_xfs_check $SCRATCH_OPTIONS $* $SCRATCH_DEV
 }
 
+# Check for secret debugging hooks in xfs_repair
+_require_libxfs_debug_flag() {
+	local hook="$1"
+
+	grep -q "$hook" "$(type -P xfs_repair)" || \
+		_notrun "libxfs debug hook $hook not detected?"
+}
+
 _scratch_xfs_repair()
 {
 	SCRATCH_OPTIONS=""
@@ -1114,3 +1122,24 @@ _xfs_get_cowgc_interval() {
 		_fail "Can't find cowgc interval procfs knob?"
 	fi
 }
+
+# Print the status of the given features on the scratch filesystem.
+# Returns 0 if all features are found, 1 otherwise.
+_check_scratch_xfs_features()
+{
+	local features="$(_scratch_xfs_db -c 'version')"
+	local output=("FEATURES:")
+	local found=0
+
+	for feature in "$@"; do
+		local status="NO"
+		if echo "${features}" | grep -q -w "${feature}"; then
+			status="YES"
+			found=$((found + 1))
+		fi
+		output+=("${feature}:${status}")
+	done
+
+	echo "${output[@]}"
+	test "${found}" -eq "$#"
+}

tests/xfs/154

@@ -0,0 +1,80 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2021 Oracle.  All Rights Reserved.
+#
+# FS QA Test No. 154
+#
+# Make sure that the kernel won't mount a filesystem if repair forcibly sets
+# NEEDSREPAIR while fixing metadata.  Corrupt a directory in such a way as
+# to force repair to write an invalid dirent value as a sentinel to trigger a
+# repair activity in a later phase.  Use a debug knob in xfs_repair to abort
+# the repair immediately after forcing the flag on.
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1    # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# real QA test starts here
+_supported_fs xfs
+_require_scratch_nocheck
+_require_scratch_xfs_crc		# needsrepair only exists for v5
+_require_libxfs_debug_flag LIBXFS_DEBUG_WRITE_CRASH
+
+rm -f $seqres.full
+
+# Set up a real filesystem for our actual test
+_scratch_mkfs >> $seqres.full
+
+# Create a directory large enough to have a dir data block.  2k worth of
+# dirent names ought to do it.
+_scratch_mount
+mkdir -p $SCRATCH_MNT/fubar
+for i in $(seq 0 256 2048); do
+	fname=$(printf "%0255d" $i)
+	ln -s -f urk $SCRATCH_MNT/fubar/$fname
+done
+inum=$(stat -c '%i' $SCRATCH_MNT/fubar)
+_scratch_unmount
+
+# Fuzz the directory
+_scratch_xfs_db -x -c "inode $inum" -c "dblock 0" \
+	-c "fuzz -d bu[2].inumber add" >> $seqres.full
+
+# Try to repair the directory, force it to crash after setting needsrepair
+LIBXFS_DEBUG_WRITE_CRASH=ddev=2 _scratch_xfs_repair 2>> $seqres.full
+test $? -eq 137 || echo "repair should have been killed??"
+
+# We can't mount, right?
+_check_scratch_xfs_features NEEDSREPAIR
+_try_scratch_mount &> $tmp.mount
+res=$?
+_filter_scratch < $tmp.mount
+if [ $res -eq 0 ]; then
+	echo "Should not be able to mount after needsrepair crash"
+	_scratch_unmount
+fi
+
+# Repair properly this time and retry the mount
+_scratch_xfs_repair 2>> $seqres.full
+_check_scratch_xfs_features NEEDSREPAIR
+
+_scratch_mount
+
+# success, all done
+status=0
+exit

tests/xfs/154.out

@@ -0,0 +1,4 @@
+QA output created by 154
+FEATURES: NEEDSREPAIR:YES
+mount: SCRATCH_MNT: mount(2) system call failed: Structure needs cleaning.
+FEATURES: NEEDSREPAIR:NO

tests/xfs/155

@@ -0,0 +1,91 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright (c) 2021 Oracle.  All Rights Reserved.
+#
+# FS QA Test No. 155
+#
+# Populate a filesystem with all types of metadata, then run repair with the
+# libxfs write failure trigger set to go after a single write.  Check that the
+# injected error trips, causing repair to abort, that needsrepair is set on the
+# fs, the kernel won't mount; and that a non-injecting repair run clears
+# needsrepair and makes the filesystem mountable again.
+#
+# Repeat with the trip point set to successively higher numbers of writes until
+# we hit ~200 writes or repair manages to run to completion without tripping.
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1    # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/populate
+. ./common/filter
+
+# real QA test starts here
+_supported_fs xfs
+_require_scratch_nocheck
+_require_scratch_xfs_crc		# needsrepair only exists for v5
+_require_populate_commands
+_require_libxfs_debug_flag LIBXFS_DEBUG_WRITE_CRASH
+
+rm -f $seqres.full
+
+# Populate the filesystem
+_scratch_populate_cached nofill >> $seqres.full 2>&1
+
+max_writes=200			# 200 loops should be enough for anyone
+nr_incr=$((13 / TIME_FACTOR))
+test $nr_incr -lt 1 && nr_incr=1
+for ((nr_writes = 1; nr_writes < max_writes; nr_writes += nr_incr)); do
+	# Add a tiny bit of randomness into each run
+	allowed_writes=$(( nr_writes + (RANDOM % 7) ))
+	echo "Setting debug hook to crash after $allowed_writes writes." >> $seqres.full
+
+	# Start a repair and force it to abort after some number of writes
+	LIBXFS_DEBUG_WRITE_CRASH=ddev=$allowed_writes \
+			_scratch_xfs_repair 2>> $seqres.full
+	res=$?
+	if [ $res -ne 0 ] && [ $res -ne 137 ]; then
+		echo "repair failed with $res??"
+		break
+	elif [ $res -eq 0 ]; then
+		[ $nr_writes -eq 1 ] && \
+			echo "ran to completion on the first try?"
+		break
+	fi
+
+	# Check the state of NEEDSREPAIR after repair fails.  If it isn't set
+	# but repair -n says the fs is clean, then it's possible that the
+	# injected error caused it to abort immediately after the write that
+	# cleared NEEDSREPAIR.
+	if ! _check_scratch_xfs_features NEEDSREPAIR > /dev/null &&
+	   ! _scratch_xfs_repair -n &>> $seqres.full; then
+		echo "NEEDSREPAIR should be set on corrupt fs"
+	fi
+done
+
+# If NEEDSREPAIR is still set on the filesystem, ensure that a full run
+# cleans everything up.
+if _check_scratch_xfs_features NEEDSREPAIR > /dev/null; then
+	echo "Clearing NEEDSREPAIR" >> $seqres.full
+	_scratch_xfs_repair 2>> $seqres.full
+	_check_scratch_xfs_features NEEDSREPAIR > /dev/null && \
+		echo "Repair failed to clear NEEDSREPAIR on the $nr_writes writes test"
+fi
+
+# success, all done
+echo Silence is golden.
+status=0
+exit

tests/xfs/155.out

@@ -0,0 +1,2 @@
+QA output created by 155
+Silence is golden.

tests/xfs/group

@@ -151,6 +151,8 @@
 151 auto quick db
 152 auto quick quota idmapped
 153 auto quick quota idmapped
+154 auto quick repair
+155 auto repair
 164 rw pattern auto prealloc quick
 165 rw pattern auto prealloc quick
 166 rw metadata auto quick