common/inject: refactor helpers to use new errortag interface

Refactor the XFS error injection helpers to use the new errortag
interface to configure error injection.  If that isn't present, fall
back either to the xfs_io/ioctl based injection or the older sysfs
knobs.  Refactor existing testcases to use the new helpers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

common/inject

@@ -35,12 +35,49 @@ _require_error_injection()
 	esac
 }
 
+# Find the errortag injection knob in sysfs for a given xfs mount's
+# block device.
+_find_xfs_mountdev_errortag_knob()
+{
+	dev="$1"
+	knob="$2"
+	shortdev="$(_short_dev "${dev}")"
+	tagfile="/sys/fs/xfs/${shortdev}/errortag/${knob}"
+
+	# Some of the new sysfs errortag knobs were previously available via
+	# another sysfs path.
+	case "${knob}" in
+	"log_bad_crc")
+		if [ ! -w "${tagfile}" ]; then
+			tagfile="/sys/fs/xfs/${shortdev}/log/log_badcrc_factor"
+		fi
+		;;
+	"drop_writes")
+		if [ ! -w "${tagfile}" ]; then
+			tagfile="/sys/fs/xfs/${shortdev}/drop_writes"
+		fi
+		if [ ! -w "${tagfile}" ]; then
+			tagfile="/sys/fs/xfs/${shortdev}/fail_writes"
+		fi
+		;;
+	*)
+		;;
+	esac
+
+	echo "${tagfile}"
+}
+
 # Requires that xfs_io inject command knows about this error type
 _require_xfs_io_error_injection()
 {
 	type="$1"
 	_require_error_injection
 
+	# Can we find the error injection knobs via the new errortag
+	# configuration mechanism?
+	knob="$(_find_xfs_mountdev_errortag_knob "${TEST_DEV}" "${type}")"
+	test -w "${knob}" && return
+
 	# NOTE: We can't actually test error injection here because xfs
 	# hasn't always range checked the argument to xfs_errortag_add.
 	# We also don't want to trip an error before we're ready to deal
@@ -54,16 +91,34 @@ _require_xfs_io_error_injection()
 _test_inject_error()
 {
 	type="$1"
+	value="$2"
 
-	$XFS_IO_PROG -x -c "inject $type" $TEST_DIR
+	knob="$(_find_xfs_mountdev_errortag_knob "${TEST_DEV}" "${type}")"
+	if [ -w "${knob}" ]; then
+		test -z "${value}" && value="default"
+		echo -n "${value}" > "${knob}"
+	elif [ -z "${value}" ] || [ "${value}" = "default" ]; then
+		$XFS_IO_PROG -x -c "inject $type" $TEST_DIR
+	else
+		_fail "Cannot inject error ${type} value ${value}."
+	fi
 }
 
 # Inject an error into the scratch fs
 _scratch_inject_error()
 {
 	type="$1"
+	value="$2"
 
-	$XFS_IO_PROG -x -c "inject $type" $SCRATCH_MNT
+	knob="$(_find_xfs_mountdev_errortag_knob "${SCRATCH_DEV}" "${type}")"
+	if [ -w "${knob}" ]; then
+		test -z "${value}" && value="default"
+		echo -n "${value}" > "${knob}"
+	elif [ -z "${value}" ] || [ "${value}" = "default" ]; then
+		$XFS_IO_PROG -x -c "inject $type" $SCRATCH_MNT
+	else
+		_fail "Cannot inject error ${type} value ${value}."
+	fi
 }
 
 # Unmount and remount the scratch device, dumping the log

tests/xfs/141

@@ -47,13 +47,14 @@ rm -f $seqres.full
 
 # get standard environment, filters and checks
 . ./common/rc
+. ./common/inject
 
 # real QA test starts here
 
 # Modify as appropriate.
 _supported_fs xfs
 _supported_os Linux
-_require_xfs_sysfs $(_short_dev $TEST_DEV)/log/log_badcrc_factor
+_require_xfs_io_error_injection "log_bad_crc"
 _require_scratch
 _require_command "$KILLALL_PROG" killall
 
@@ -69,7 +70,7 @@ for i in $(seq 1 5); do
 	# (increase this value to run fsstress longer).
 	factor=$((RANDOM % 100 + 1))
 	echo iteration $i log_badcrc_factor: $factor >> $seqres.full 2>&1
-	echo $factor > /sys/fs/xfs/$sdev/log/log_badcrc_factor
+	_scratch_inject_error "log_bad_crc" "$factor"
 
 	# Run fsstress until the filesystem shuts down. It will shut down
 	# automatically when error injection triggers.

tests/xfs/196

@@ -45,6 +45,7 @@ _cleanup()
 # get standard environment, filters and checks
 . ./common/rc
 . ./common/punch
+. ./common/inject
 
 # real QA test starts here
 rm -f $seqres.full
@@ -53,13 +54,7 @@ rm -f $seqres.full
 _supported_fs generic
 _supported_os Linux
 _require_scratch
-
-DROP_WRITES="drop_writes"
-# replace "drop_writes" with "fail_writes" for old kernel
-if [ -f /sys/fs/xfs/$(_short_dev $TEST_DEV)/fail_writes ];then
-	DROP_WRITES="fail_writes"
-fi
-_require_xfs_sysfs $(_short_dev $TEST_DEV)/${DROP_WRITES}
+_require_xfs_io_error_injection "drop_writes"
 
 _scratch_mkfs >/dev/null 2>&1
 _scratch_mount
@@ -72,7 +67,7 @@ bytes=$((64 * 1024))
 $XFS_IO_PROG -f -c "pwrite 0 $bytes" $file >> $seqres.full 2>&1
 
 # Enable write drops. All buffered writes are dropped from this point on.
-echo 1 > /sys/fs/xfs/$sdev/$DROP_WRITES
+_scratch_inject_error "drop_writes" 1
 
 # Write every other 4k range to split the larger delalloc extent into many more
 # smaller extents. Use pwrite because with write failures enabled, all
@@ -89,7 +84,7 @@ for i in $(seq 4096 8192 $endoff); do
 	$XFS_IO_PROG -c "pwrite $i 4k" $file >> $seqres.full 2>&1
 done
 
-echo 0 > /sys/fs/xfs/$sdev/$DROP_WRITES
+_scratch_inject_error "drop_writes" 0
 
 _scratch_cycle_mount
 $XFS_IO_PROG -c 'bmap -vp' $file | _filter_bmap
@@ -104,9 +99,9 @@ for offset in $(seq 0 100 500); do
 	$XFS_IO_PROG -fc "pwrite ${offset}m 100m" $file >> $seqres.full 2>&1
 
 	punchoffset=$((offset + 75))
-	echo 1 > /sys/fs/xfs/$sdev/$DROP_WRITES
+	_scratch_inject_error "drop_writes"
 	$XFS_IO_PROG -c "pwrite ${punchoffset}m 4k" $file >> $seqres.full 2>&1
-	echo 0 > /sys/fs/xfs/$sdev/$DROP_WRITES
+	_scratch_inject_error "drop_writes" 0
 done
 
 echo "Silence is golden."