[PATCH 0/2] xfs: test xfs_scrub media scan

[PATCH 0/2] xfs: test xfs_scrub media scan

[Darrick J. Wong]

Hi all,

Simple tests of the xfs_scrub media verifier that uses dm-error to
simulate disk errors and ensure that the reporting is accurate.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This is an extraordinary way to destroy everything.  Enjoy!
Comments and questions are, as always, welcome.

--D

xfsprogs git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfsprogs-dev.git/log/?h=scrub-media-error-reporting

fstests git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfstests-dev.git/log/?h=scrub-media-error-reporting

[PATCH 1/2] common/dmerror: always try to resume device

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

When we're reloading the error-target dm table, always resume the device
even if the reload fails because (a) we shouldn't leave dm state for the
callers to clean up and (b) the caller don't clean up the state which
just leads to the scratch filesystem hanging on the suspended dm error
device.  Resume the dm device when we're cleaning up so that cleaning up
the scratch filesystem won't hang.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 common/dmerror |   15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)


diff --git a/common/dmerror b/common/dmerror
index 8c52e127..ca1c7335 100644
--- a/common/dmerror
+++ b/common/dmerror
@@ -44,6 +44,7 @@ _dmerror_unmount()
 
 _dmerror_cleanup()
 {
+	$DMSETUP_PROG resume error-test > /dev/null 2>&1
 	$UMOUNT_PROG $SCRATCH_MNT > /dev/null 2>&1
 	_dmsetup_remove error-test
 }
@@ -62,10 +63,13 @@ _dmerror_load_error_table()
 	[ $? -ne 0 ] && _fail  "dmsetup suspend failed"
 
 	$DMSETUP_PROG load error-test --table "$DMERROR_TABLE"
-	[ $? -ne 0 ] && _fail "dmsetup failed to load error table"
+	load_res=$?
 
 	$DMSETUP_PROG resume error-test
-	[ $? -ne 0 ] && _fail  "dmsetup resume failed"
+	resume_res=$?
+
+	[ $load_res -ne 0 ] && _fail "dmsetup failed to load error table"
+	[ $resume_res -ne 0 ] && _fail  "dmsetup resume failed"
 }
 
 _dmerror_load_working_table()
@@ -82,8 +86,11 @@ _dmerror_load_working_table()
 	[ $? -ne 0 ] && _fail  "dmsetup suspend failed"
 
 	$DMSETUP_PROG load error-test --table "$DMLINEAR_TABLE"
-	[ $? -ne 0 ] && _fail "dmsetup failed to load error table"
+	load_res=$?
 
 	$DMSETUP_PROG resume error-test
-	[ $? -ne 0 ] && _fail  "dmsetup resume failed"
+	resume_res=$?
+
+	[ $load_res -ne 0 ] && _fail "dmsetup failed to load error table"
+	[ $resume_res -ne 0 ] && _fail  "dmsetup resume failed"
 }

[PATCH 2/2] xfs: test xfs_scrub phase 6 media error reporting

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Add new helpers to dmerror to provide for marking selected ranges
totally bad -- both reads and writes will fail.  Create a new test for
xfs_scrub to check that it reports media errors correctly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 common/dmerror    |  107 +++++++++++++++++++++++++++++++++++++++++-
 tests/xfs/747     |  136 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/747.out |   12 +++++
 tests/xfs/748     |  102 ++++++++++++++++++++++++++++++++++++++++
 tests/xfs/748.out |    5 ++
 tests/xfs/group   |    2 +
 6 files changed, 363 insertions(+), 1 deletion(-)
 create mode 100755 tests/xfs/747
 create mode 100644 tests/xfs/747.out
 create mode 100755 tests/xfs/748
 create mode 100644 tests/xfs/748.out


diff --git a/common/dmerror b/common/dmerror
index ca1c7335..ee3051f1 100644
--- a/common/dmerror
+++ b/common/dmerror
@@ -62,7 +62,7 @@ _dmerror_load_error_table()
 	$DMSETUP_PROG suspend $suspend_opt error-test
 	[ $? -ne 0 ] && _fail  "dmsetup suspend failed"
 
-	$DMSETUP_PROG load error-test --table "$DMERROR_TABLE"
+	echo "$DMERROR_TABLE" | $DMSETUP_PROG load error-test
 	load_res=$?
 
 	$DMSETUP_PROG resume error-test
@@ -94,3 +94,108 @@ _dmerror_load_working_table()
 	[ $load_res -ne 0 ] && _fail "dmsetup failed to load error table"
 	[ $resume_res -ne 0 ] && _fail  "dmsetup resume failed"
 }
+
+# Given a list of (start, length) tuples on stdin, combine adjacent tuples into
+# larger ones and write the new list to stdout.
+__dmerror_combine_extents()
+{
+	awk 'BEGIN{start = 0; len = 0;}{
+if (start + len == $1) {
+	len += $2;
+} else {
+	if (len > 0)
+		printf("%d %d\n", start, len);
+	start = $1;
+	len = $2;
+}
+} END {
+	if (len > 0)
+		printf("%d %d\n", start, len);
+}'
+}
+
+# Given a block device, the name of a preferred dm target, the name of an
+# implied dm target, and a list of (start, len) tuples on stdin, create a new
+# dm table which maps each of the tuples to the preferred target and all other
+# areas to the implied dm target.
+__dmerror_recreate_map()
+{
+	local device="$1"
+	local preferred_tgt="$2"
+	local implied_tgt="$3"
+	local size=$(blockdev --getsz "$device")
+
+	awk -v device="$device" -v size=$size -v implied_tgt="$implied_tgt" \
+		-v preferred_tgt="$preferred_tgt" 'BEGIN{implied_start = 0;}{
+	extent_start = $1;
+	extent_len = $2;
+
+	if (extent_start > size) {
+		extent_start = size;
+		extent_len = 0;
+	} else if (extent_start + extent_len > size) {
+		extent_len = size - extent_start;
+	}
+
+	if (implied_start < extent_start)
+		printf("%d %d %s %s %d\n", implied_start,
+				extent_start - implied_start, implied_tgt,
+				device, implied_start);
+	printf("%d %d %s %s %d\n", extent_start, extent_len, preferred_tgt,
+			device, extent_start);
+	implied_start = extent_start + extent_len;
+}END{
+	if (implied_start < size)
+		printf("%d %d %s %s %d\n", implied_start, size - implied_start,
+				implied_tgt, device, implied_start);
+}'
+}
+
+# Update the dm error table so that the range (start, len) maps to the
+# preferred dm target, overriding anything that maps to the implied dm target.
+# This assumes that the only desired targets for this dm device are the
+# preferred and and implied targets.  The optional fifth argument can be used
+# to change the underlying device.
+__dmerror_change()
+{
+	local start="$1"
+	local len="$2"
+	local preferred_tgt="$3"
+	local implied_tgt="$4"
+	local dm_backing_dev="$5"
+	test -z "$dm_backing_dev" && dm_backing_dev="$SCRATCH_DEV"
+
+	DMERROR_TABLE="$( (echo "$DMERROR_TABLE"; echo "$start $len $preferred_tgt") | \
+		awk -v type="$preferred_tgt" '{if ($3 == type) print $0;}' | \
+		sort -g | \
+		__dmerror_combine_extents | \
+		__dmerror_recreate_map "$dm_backing_dev" "$preferred_tgt" \
+				"$implied_tgt" )"
+}
+
+# Reset the dm error table to everything ok.  The dm device itself must be
+# remapped by calling _dmerror_load_error_table.
+_dmerror_reset_table()
+{
+	DMERROR_TABLE="$DMLINEAR_TABLE"
+}
+
+# Update the dm error table so that IOs to the given range will return EIO.
+# The dm device itself must be remapped by calling _dmerror_load_error_table.
+_dmerror_mark_range_bad()
+{
+	local start="$1"
+	local len="$2"
+
+	__dmerror_change "$start" "$len" error linear
+}
+
+# Update the dm error table so that IOs to the given range will succeed.
+# The dm device itself must be remapped by calling _dmerror_load_error_table.
+_dmerror_mark_range_good()
+{
+	local start="$1"
+	local len="$2"
+
+	__dmerror_change "$start" "$len" linear error
+}
diff --git a/tests/xfs/747 b/tests/xfs/747
new file mode 100755
index 00000000..f5894411
--- /dev/null
+++ b/tests/xfs/747
@@ -0,0 +1,136 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-newer
+# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
+#
+# FS QA Test No. 747
+#
+# Check xfs_scrub's media scan can actually return diagnostic information for
+# media errors in file data extents.
+
+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.error
+	_dmerror_cleanup
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/fuzzy
+. ./common/filter
+. ./common/dmerror
+
+# real QA test starts here
+_supported_fs xfs
+_supported_os Linux
+_require_dm_target error
+_require_scratch_xfs_crc
+_require_scrub
+
+rm -f $seqres.full
+
+filter_scrub_errors() {
+	_filter_scratch | sed -e "s/offset $((blksz * 2)) /offset 2FSB /g" \
+		-e "s/length $blksz.*/length 1FSB./g"
+}
+
+_scratch_mkfs > $tmp.mkfs
+_dmerror_init
+_dmerror_mount >> $seqres.full 2>&1
+
+_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
+
+victim=$SCRATCH_MNT/a
+$XFS_IO_PROG -f -c "pwrite -S 0x58 0 1m" -c "fsync" $victim >> $seqres.full
+bmap_str="$($XFS_IO_PROG -c "bmap -elpv" $victim | grep "^[[:space:]]*0:")"
+echo "$bmap_str" >> $seqres.full
+
+phys="$(echo "$bmap_str" | awk '{print $3}')"
+len="$(echo "$bmap_str" | awk '{print $6}')"
+blksz=$(_get_file_block_size $SCRATCH_MNT)
+sectors_per_block=$((blksz / 512))
+
+# Did we get at least 4 fs blocks worth of extent?
+min_len_sectors=$(( 4 * sectors_per_block ))
+test "$len" -lt $min_len_sectors && \
+	_fail "could not format a long enough extent on an empty fs??"
+
+phys_start=$(echo "$phys" | sed -e 's/\.\..*//g')
+
+
+echo ":$phys:$len:$blksz:$phys_start" >> $seqres.full
+echo "victim file:" >> $seqres.full
+od -tx1 -Ad -c $victim >> $seqres.full
+
+# Reset the dmerror table so that all IO will pass through.
+_dmerror_reset_table
+
+cat >> $seqres.full << ENDL
+dmerror before:
+$DMERROR_TABLE
+<end table>
+ENDL
+
+# Now mark /only/ the middle of the extent bad.
+_dmerror_mark_range_bad $(( phys_start + (2 * sectors_per_block) + 1 )) 1
+
+cat >> $seqres.full << ENDL
+dmerror after marking bad:
+$DMERROR_TABLE
+<end table>
+ENDL
+
+_dmerror_load_error_table
+
+# See if the media scan picks it up.
+echo "Scrub for injected media error (single threaded)"
+
+# Once in single-threaded mode
+_scratch_scrub -b -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# Once in parallel mode
+echo "Scrub for injected media error (multi threaded)"
+_scratch_scrub -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# Remount to flush the page cache and reread to see the IO error
+_dmerror_unmount
+_dmerror_mount
+echo "victim file:" >> $seqres.full
+od -tx1 -Ad -c $victim >> $seqres.full 2> $tmp.error
+cat $tmp.error | _filter_scratch
+
+# Scrub again to re-confirm the media error across a remount
+echo "Scrub for injected media error (after remount)"
+_scratch_scrub -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# Now mark the bad range good.
+_dmerror_mark_range_good $(( phys_start + (2 * sectors_per_block) + 1 )) 1
+_dmerror_load_error_table
+
+cat >> $seqres.full << ENDL
+dmerror after marking good:
+$DMERROR_TABLE
+<end table>
+ENDL
+
+echo "Scrub after removing injected media error"
+
+# Scrub one last time to make sure the error's gone.
+_scratch_scrub -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/747.out b/tests/xfs/747.out
new file mode 100644
index 00000000..f85f1753
--- /dev/null
+++ b/tests/xfs/747.out
@@ -0,0 +1,12 @@
+QA output created by 747
+Scrub for injected media error (single threaded)
+Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
+SCRATCH_MNT: unfixable errors found: 1
+Scrub for injected media error (multi threaded)
+Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
+SCRATCH_MNT: unfixable errors found: 1
+od: SCRATCH_MNT/a: read error: Input/output error
+Scrub for injected media error (after remount)
+Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
+SCRATCH_MNT: unfixable errors found: 1
+Scrub after removing injected media error
diff --git a/tests/xfs/748 b/tests/xfs/748
new file mode 100755
index 00000000..130cc6f2
--- /dev/null
+++ b/tests/xfs/748
@@ -0,0 +1,102 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0-or-newer
+# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
+#
+# FS QA Test No. 748
+#
+# Check xfs_scrub's media scan can actually return diagnostic information for
+# media errors in filesystem metadata.
+
+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.error $tmp.fsmap
+	_dmerror_cleanup
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/fuzzy
+. ./common/filter
+. ./common/dmerror
+
+# real QA test starts here
+_supported_fs xfs
+_supported_os Linux
+_require_dm_target error
+_require_xfs_scratch_rmapbt
+_require_scrub
+
+rm -f $seqres.full
+
+filter_scrub_errors() {
+	_filter_scratch | sed -e "s/disk offset [0-9]*: /disk offset NNN: /g" \
+		-e "/errors found:/d" -e 's/phase6.c line [0-9]*/!/g' \
+		-e "/corruptions found:/d" | uniq
+}
+
+_scratch_mkfs > $tmp.mkfs
+_dmerror_init
+_dmerror_mount >> $seqres.full 2>&1
+
+_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
+
+# Create a bunch of metadata so that we can mark them bad in the next step.
+victim=$SCRATCH_MNT/a
+$FSSTRESS_PROG -z -n 200 -p 10 \
+	       -f creat=10 \
+	       -f resvsp=1 \
+	       -f truncate=1 \
+	       -f punch=1 \
+	       -f chown=5 \
+	       -f mkdir=5 \
+	       -f mknod=1 \
+	       -d $victim >> $seqres.full 2>&1
+
+# Mark all the metadata bad
+_dmerror_reset_table
+$XFS_IO_PROG -c "fsmap -n100 -vvv" $victim | grep inodes > $tmp.fsmap
+while read a b c crap; do
+	phys="$(echo $c | sed -e 's/^.\([0-9]*\)\.\.\([0-9]*\).*$/\1:\2/g')"
+	target_begin="$(echo "$phys" | cut -d ':' -f 1)"
+	target_end="$(echo "$phys" | cut -d ':' -f 2)"
+
+	_dmerror_mark_range_bad $target_begin $((target_end - target_begin))
+done < $tmp.fsmap
+cat $tmp.fsmap >> $seqres.full
+
+cat >> $seqres.full << ENDL
+dmerror after marking bad:
+$DMERROR_TABLE
+<end table>
+ENDL
+
+_dmerror_load_error_table
+
+# See if the media scan picks it up.
+echo "Scrub for injected media error"
+
+XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# Make the disk work again
+_dmerror_load_working_table
+
+echo "Scrub after removing injected media error"
+
+# Scrub one last time to make sure the error's gone.
+XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
+cat $tmp.error | filter_scrub_errors
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/748.out b/tests/xfs/748.out
new file mode 100644
index 00000000..49dc2d7a
--- /dev/null
+++ b/tests/xfs/748.out
@@ -0,0 +1,5 @@
+QA output created by 748
+Scrub for injected media error
+Corruption: disk offset NNN: media error in inodes. (!)
+SCRATCH_MNT: Unmount and run xfs_repair.
+Scrub after removing injected media error
diff --git a/tests/xfs/group b/tests/xfs/group
index 18a593d9..3a58864b 100644
--- a/tests/xfs/group
+++ b/tests/xfs/group
@@ -509,3 +509,5 @@
 510 auto ioctl quick
 511 auto quick quota
 741 auto quick rw
+747 auto quick scrub
+748 auto quick scrub

Re: [PATCH 2/2] xfs: test xfs_scrub phase 6 media error reporting

[Eryu Guan]

On Tue, Dec 10, 2019 at 09:38:38PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Add new helpers to dmerror to provide for marking selected ranges
> totally bad -- both reads and writes will fail.  Create a new test for
> xfs_scrub to check that it reports media errors correctly.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

I hit assert failure when testing on v5.5-rc3+ kernel, is that an
expected result? Both test failed in the same way.

[  192.610313] xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff)
[  193.149329] Buffer I/O error on dev dm-11, logical block 128, async page read
[  193.150173] Buffer I/O error on dev dm-11, logical block 129, async page read
[  193.151254] Buffer I/O error on dev dm-11, logical block 130, async page read
[  193.152173] Buffer I/O error on dev dm-11, logical block 131, async page read
[  193.152980] Buffer I/O error on dev dm-11, logical block 132, async page read
[  193.153935] Buffer I/O error on dev dm-11, logical block 133, async page read
[  193.154869] Buffer I/O error on dev dm-11, logical block 134, async page read
[  193.155800] Buffer I/O error on dev dm-11, logical block 135, async page read
[  193.249751] XFS: Assertion failed: !(sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR), file: fs/xfs/scrub/repair.h, line: 78
[  193.255979] ------------[ cut here ]------------
[  193.258406] kernel BUG at fs/xfs/xfs_message.c:110!
[  193.260996] invalid opcode: 0000 [#1] SMP PTI
[  193.263323] CPU: 0 PID: 5613 Comm: xfs_scrub Not tainted 5.5.0-rc3+ #44
[  193.266717] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
[  193.273736] RIP: 0010:assfail+0x23/0x28 [xfs]
[  193.276045] Code: 67 fc ff ff 0f 0b c3 0f 1f 44 00 00 41 89 c8 48 89 d1 48 89 f2 48 c7 c6 78 e9 8d c0 e8 82 f9 ff ff 80 3d 9a d7 08 00 00 74 02 <0f> 0b 0f 0b c3 48 8b 03 48 c7 c7 68 ee 8d c0 c6 05 0e 2b 0a 00 01
[  193.284481] RSP: 0018:ffffac9540b7fbe0 EFLAGS: 00010202
[  193.286297] RAX: 0000000000000000 RBX: ffffac9540b7fcc8 RCX: 0000000000000000
[  193.288390] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffffc08d144a
[  193.290235] RBP: ffffac9540b7fbf8 R08: 0000000000000000 R09: 0000000000000000
[  193.292083] R10: 000000000000000a R11: f000000000000000 R12: 0000000000000000
[  193.293589] R13: ffff90006701c000 R14: ffff900071746400 R15: ffff900071746558
[  193.295068] FS:  00007f91892cc740(0000) GS:ffff900078c00000(0000) knlGS:0000000000000000
[  193.296899] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  193.297977] CR2: 0000000001ef0078 CR3: 0000000236050002 CR4: 00000000003606f0
[  193.299234] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  193.300555] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  193.301805] Call Trace:
[  193.302296]  xchk_setup_fs+0x35/0x40 [xfs]
[  193.302937]  xfs_scrub_metadata+0x23d/0x480 [xfs]
[  193.303658]  xfs_ioc_scrub_metadata+0x50/0xa0 [xfs]
[  193.304417]  xfs_file_ioctl+0xb23/0xc60 [xfs]
[  193.305075]  ? pagevec_lru_move_fn+0xbd/0xe0
[  193.305719]  ? get_kernel_page+0x60/0x60
[  193.306321]  ? __lru_cache_add+0x62/0x80
[  193.306922]  ? __handle_mm_fault+0xc65/0x1930
[  193.307553]  do_vfs_ioctl+0x448/0x6c0
[  193.308042]  ? handle_mm_fault+0xc4/0x1f0
[  193.308572]  ksys_ioctl+0x5e/0x90
[  193.309006]  __x64_sys_ioctl+0x16/0x20
[  193.309501]  do_syscall_64+0x5b/0x1d0
[  193.309990]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

> ---
>  common/dmerror    |  107 +++++++++++++++++++++++++++++++++++++++++-
>  tests/xfs/747     |  136 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/747.out |   12 +++++
>  tests/xfs/748     |  102 ++++++++++++++++++++++++++++++++++++++++
>  tests/xfs/748.out |    5 ++
>  tests/xfs/group   |    2 +
>  6 files changed, 363 insertions(+), 1 deletion(-)
>  create mode 100755 tests/xfs/747
>  create mode 100644 tests/xfs/747.out
>  create mode 100755 tests/xfs/748
>  create mode 100644 tests/xfs/748.out
> 
> 
> diff --git a/common/dmerror b/common/dmerror
> index ca1c7335..ee3051f1 100644
> --- a/common/dmerror
> +++ b/common/dmerror
> @@ -62,7 +62,7 @@ _dmerror_load_error_table()
>  	$DMSETUP_PROG suspend $suspend_opt error-test
>  	[ $? -ne 0 ] && _fail  "dmsetup suspend failed"
>  
> -	$DMSETUP_PROG load error-test --table "$DMERROR_TABLE"
> +	echo "$DMERROR_TABLE" | $DMSETUP_PROG load error-test
>  	load_res=$?
>  
>  	$DMSETUP_PROG resume error-test
> @@ -94,3 +94,108 @@ _dmerror_load_working_table()
>  	[ $load_res -ne 0 ] && _fail "dmsetup failed to load error table"
>  	[ $resume_res -ne 0 ] && _fail  "dmsetup resume failed"
>  }
> +
> +# Given a list of (start, length) tuples on stdin, combine adjacent tuples into
> +# larger ones and write the new list to stdout.
> +__dmerror_combine_extents()
> +{
> +	awk 'BEGIN{start = 0; len = 0;}{

$AWK_PROG

> +if (start + len == $1) {
> +	len += $2;
> +} else {
> +	if (len > 0)
> +		printf("%d %d\n", start, len);
> +	start = $1;
> +	len = $2;
> +}
> +} END {
> +	if (len > 0)
> +		printf("%d %d\n", start, len);
> +}'
> +}
> +
> +# Given a block device, the name of a preferred dm target, the name of an
> +# implied dm target, and a list of (start, len) tuples on stdin, create a new
> +# dm table which maps each of the tuples to the preferred target and all other
> +# areas to the implied dm target.
> +__dmerror_recreate_map()
> +{
> +	local device="$1"
> +	local preferred_tgt="$2"
> +	local implied_tgt="$3"
> +	local size=$(blockdev --getsz "$device")
> +
> +	awk -v device="$device" -v size=$size -v implied_tgt="$implied_tgt" \

Same here.

> +		-v preferred_tgt="$preferred_tgt" 'BEGIN{implied_start = 0;}{
> +	extent_start = $1;
> +	extent_len = $2;
> +
> +	if (extent_start > size) {
> +		extent_start = size;
> +		extent_len = 0;
> +	} else if (extent_start + extent_len > size) {
> +		extent_len = size - extent_start;
> +	}
> +
> +	if (implied_start < extent_start)
> +		printf("%d %d %s %s %d\n", implied_start,
> +				extent_start - implied_start, implied_tgt,
> +				device, implied_start);
> +	printf("%d %d %s %s %d\n", extent_start, extent_len, preferred_tgt,
> +			device, extent_start);
> +	implied_start = extent_start + extent_len;
> +}END{
> +	if (implied_start < size)
> +		printf("%d %d %s %s %d\n", implied_start, size - implied_start,
> +				implied_tgt, device, implied_start);
> +}'
> +}
> +
> +# Update the dm error table so that the range (start, len) maps to the
> +# preferred dm target, overriding anything that maps to the implied dm target.
> +# This assumes that the only desired targets for this dm device are the
> +# preferred and and implied targets.  The optional fifth argument can be used
> +# to change the underlying device.
> +__dmerror_change()
> +{
> +	local start="$1"
> +	local len="$2"
> +	local preferred_tgt="$3"
> +	local implied_tgt="$4"
> +	local dm_backing_dev="$5"
> +	test -z "$dm_backing_dev" && dm_backing_dev="$SCRATCH_DEV"
> +
> +	DMERROR_TABLE="$( (echo "$DMERROR_TABLE"; echo "$start $len $preferred_tgt") | \
> +		awk -v type="$preferred_tgt" '{if ($3 == type) print $0;}' | \

Same here.

> +		sort -g | \
> +		__dmerror_combine_extents | \
> +		__dmerror_recreate_map "$dm_backing_dev" "$preferred_tgt" \
> +				"$implied_tgt" )"
> +}
> +
> +# Reset the dm error table to everything ok.  The dm device itself must be
> +# remapped by calling _dmerror_load_error_table.
> +_dmerror_reset_table()
> +{
> +	DMERROR_TABLE="$DMLINEAR_TABLE"
> +}
> +
> +# Update the dm error table so that IOs to the given range will return EIO.
> +# The dm device itself must be remapped by calling _dmerror_load_error_table.
> +_dmerror_mark_range_bad()
> +{
> +	local start="$1"
> +	local len="$2"
> +
> +	__dmerror_change "$start" "$len" error linear
> +}
> +
> +# Update the dm error table so that IOs to the given range will succeed.
> +# The dm device itself must be remapped by calling _dmerror_load_error_table.
> +_dmerror_mark_range_good()
> +{
> +	local start="$1"
> +	local len="$2"
> +
> +	__dmerror_change "$start" "$len" linear error
> +}
> diff --git a/tests/xfs/747 b/tests/xfs/747
> new file mode 100755
> index 00000000..f5894411
> --- /dev/null
> +++ b/tests/xfs/747
> @@ -0,0 +1,136 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0-or-newer
> +# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
> +#
> +# FS QA Test No. 747
> +#
> +# Check xfs_scrub's media scan can actually return diagnostic information for
> +# media errors in file data extents.
> +
> +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.error

	rm -f $tmp.*

would be find. Otherwise files like $tmp.mkfs are still there.

> +	_dmerror_cleanup
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/fuzzy
> +. ./common/filter
> +. ./common/dmerror
> +
> +# real QA test starts here
> +_supported_fs xfs
> +_supported_os Linux
> +_require_dm_target error
> +_require_scratch_xfs_crc
> +_require_scrub
> +
> +rm -f $seqres.full
> +
> +filter_scrub_errors() {
> +	_filter_scratch | sed -e "s/offset $((blksz * 2)) /offset 2FSB /g" \
> +		-e "s/length $blksz.*/length 1FSB./g"
> +}
> +
> +_scratch_mkfs > $tmp.mkfs
> +_dmerror_init
> +_dmerror_mount >> $seqres.full 2>&1
> +
> +_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
> +
> +victim=$SCRATCH_MNT/a
> +$XFS_IO_PROG -f -c "pwrite -S 0x58 0 1m" -c "fsync" $victim >> $seqres.full
> +bmap_str="$($XFS_IO_PROG -c "bmap -elpv" $victim | grep "^[[:space:]]*0:")"
> +echo "$bmap_str" >> $seqres.full
> +
> +phys="$(echo "$bmap_str" | awk '{print $3}')"
> +len="$(echo "$bmap_str" | awk '{print $6}')"
> +blksz=$(_get_file_block_size $SCRATCH_MNT)
> +sectors_per_block=$((blksz / 512))
> +
> +# Did we get at least 4 fs blocks worth of extent?
> +min_len_sectors=$(( 4 * sectors_per_block ))
> +test "$len" -lt $min_len_sectors && \
> +	_fail "could not format a long enough extent on an empty fs??"
> +
> +phys_start=$(echo "$phys" | sed -e 's/\.\..*//g')
> +
> +
> +echo ":$phys:$len:$blksz:$phys_start" >> $seqres.full
> +echo "victim file:" >> $seqres.full
> +od -tx1 -Ad -c $victim >> $seqres.full
> +
> +# Reset the dmerror table so that all IO will pass through.
> +_dmerror_reset_table
> +
> +cat >> $seqres.full << ENDL
> +dmerror before:
> +$DMERROR_TABLE
> +<end table>
> +ENDL
> +
> +# Now mark /only/ the middle of the extent bad.
> +_dmerror_mark_range_bad $(( phys_start + (2 * sectors_per_block) + 1 )) 1
> +
> +cat >> $seqres.full << ENDL
> +dmerror after marking bad:
> +$DMERROR_TABLE
> +<end table>
> +ENDL
> +
> +_dmerror_load_error_table
> +
> +# See if the media scan picks it up.
> +echo "Scrub for injected media error (single threaded)"
> +
> +# Once in single-threaded mode
> +_scratch_scrub -b -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# Once in parallel mode
> +echo "Scrub for injected media error (multi threaded)"
> +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# Remount to flush the page cache and reread to see the IO error
> +_dmerror_unmount
> +_dmerror_mount
> +echo "victim file:" >> $seqres.full
> +od -tx1 -Ad -c $victim >> $seqres.full 2> $tmp.error
> +cat $tmp.error | _filter_scratch
> +
> +# Scrub again to re-confirm the media error across a remount
> +echo "Scrub for injected media error (after remount)"
> +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# Now mark the bad range good.
> +_dmerror_mark_range_good $(( phys_start + (2 * sectors_per_block) + 1 )) 1
> +_dmerror_load_error_table
> +
> +cat >> $seqres.full << ENDL
> +dmerror after marking good:
> +$DMERROR_TABLE
> +<end table>
> +ENDL
> +
> +echo "Scrub after removing injected media error"
> +
> +# Scrub one last time to make sure the error's gone.
> +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/747.out b/tests/xfs/747.out
> new file mode 100644
> index 00000000..f85f1753
> --- /dev/null
> +++ b/tests/xfs/747.out
> @@ -0,0 +1,12 @@
> +QA output created by 747
> +Scrub for injected media error (single threaded)
> +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> +SCRATCH_MNT: unfixable errors found: 1
> +Scrub for injected media error (multi threaded)
> +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> +SCRATCH_MNT: unfixable errors found: 1
> +od: SCRATCH_MNT/a: read error: Input/output error
> +Scrub for injected media error (after remount)
> +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> +SCRATCH_MNT: unfixable errors found: 1
> +Scrub after removing injected media error
> diff --git a/tests/xfs/748 b/tests/xfs/748
> new file mode 100755
> index 00000000..130cc6f2
> --- /dev/null
> +++ b/tests/xfs/748
> @@ -0,0 +1,102 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0-or-newer
> +# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
> +#
> +# FS QA Test No. 748
> +#
> +# Check xfs_scrub's media scan can actually return diagnostic information for
> +# media errors in filesystem metadata.
> +
> +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.error $tmp.fsmap

rm -f $tmp.*

> +	_dmerror_cleanup
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/fuzzy
> +. ./common/filter
> +. ./common/dmerror
> +
> +# real QA test starts here
> +_supported_fs xfs
> +_supported_os Linux
> +_require_dm_target error
> +_require_xfs_scratch_rmapbt

Add a comment on why rmapbt is needed?

Thanks,
Eryu

> +_require_scrub
> +
> +rm -f $seqres.full
> +
> +filter_scrub_errors() {
> +	_filter_scratch | sed -e "s/disk offset [0-9]*: /disk offset NNN: /g" \
> +		-e "/errors found:/d" -e 's/phase6.c line [0-9]*/!/g' \
> +		-e "/corruptions found:/d" | uniq
> +}
> +
> +_scratch_mkfs > $tmp.mkfs
> +_dmerror_init
> +_dmerror_mount >> $seqres.full 2>&1
> +
> +_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
> +
> +# Create a bunch of metadata so that we can mark them bad in the next step.
> +victim=$SCRATCH_MNT/a
> +$FSSTRESS_PROG -z -n 200 -p 10 \
> +	       -f creat=10 \
> +	       -f resvsp=1 \
> +	       -f truncate=1 \
> +	       -f punch=1 \
> +	       -f chown=5 \
> +	       -f mkdir=5 \
> +	       -f mknod=1 \
> +	       -d $victim >> $seqres.full 2>&1
> +
> +# Mark all the metadata bad
> +_dmerror_reset_table
> +$XFS_IO_PROG -c "fsmap -n100 -vvv" $victim | grep inodes > $tmp.fsmap
> +while read a b c crap; do
> +	phys="$(echo $c | sed -e 's/^.\([0-9]*\)\.\.\([0-9]*\).*$/\1:\2/g')"
> +	target_begin="$(echo "$phys" | cut -d ':' -f 1)"
> +	target_end="$(echo "$phys" | cut -d ':' -f 2)"
> +
> +	_dmerror_mark_range_bad $target_begin $((target_end - target_begin))
> +done < $tmp.fsmap
> +cat $tmp.fsmap >> $seqres.full
> +
> +cat >> $seqres.full << ENDL
> +dmerror after marking bad:
> +$DMERROR_TABLE
> +<end table>
> +ENDL
> +
> +_dmerror_load_error_table
> +
> +# See if the media scan picks it up.
> +echo "Scrub for injected media error"
> +
> +XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# Make the disk work again
> +_dmerror_load_working_table
> +
> +echo "Scrub after removing injected media error"
> +
> +# Scrub one last time to make sure the error's gone.
> +XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
> +cat $tmp.error | filter_scrub_errors
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/748.out b/tests/xfs/748.out
> new file mode 100644
> index 00000000..49dc2d7a
> --- /dev/null
> +++ b/tests/xfs/748.out
> @@ -0,0 +1,5 @@
> +QA output created by 748
> +Scrub for injected media error
> +Corruption: disk offset NNN: media error in inodes. (!)
> +SCRATCH_MNT: Unmount and run xfs_repair.
> +Scrub after removing injected media error
> diff --git a/tests/xfs/group b/tests/xfs/group
> index 18a593d9..3a58864b 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -509,3 +509,5 @@
>  510 auto ioctl quick
>  511 auto quick quota
>  741 auto quick rw
> +747 auto quick scrub
> +748 auto quick scrub
> 

Re: [PATCH 2/2] xfs: test xfs_scrub phase 6 media error reporting

[Darrick J. Wong]

On Mon, Jan 06, 2020 at 03:58:30PM +0800, Eryu Guan wrote:
> On Tue, Dec 10, 2019 at 09:38:38PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Add new helpers to dmerror to provide for marking selected ranges
> > totally bad -- both reads and writes will fail.  Create a new test for
> > xfs_scrub to check that it reports media errors correctly.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> 
> I hit assert failure when testing on v5.5-rc3+ kernel, is that an
> expected result? Both test failed in the same way.

Oh, my.  That's a bogus assertion in xrep_calc_ag_resblks when
CONFIG_XFS_ONLINE_REPAIR=n.  That's definitely a kernel bug, though it's
not related to this test.  I'll start working on a fix, thank you for
reporting this!

> 
> [  192.610313] xfs filesystem being mounted at /mnt/scratch supports timestamps until 2038 (0x7fffffff)
> [  193.149329] Buffer I/O error on dev dm-11, logical block 128, async page read
> [  193.150173] Buffer I/O error on dev dm-11, logical block 129, async page read
> [  193.151254] Buffer I/O error on dev dm-11, logical block 130, async page read
> [  193.152173] Buffer I/O error on dev dm-11, logical block 131, async page read
> [  193.152980] Buffer I/O error on dev dm-11, logical block 132, async page read
> [  193.153935] Buffer I/O error on dev dm-11, logical block 133, async page read
> [  193.154869] Buffer I/O error on dev dm-11, logical block 134, async page read
> [  193.155800] Buffer I/O error on dev dm-11, logical block 135, async page read
> [  193.249751] XFS: Assertion failed: !(sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR), file: fs/xfs/scrub/repair.h, line: 78
> [  193.255979] ------------[ cut here ]------------
> [  193.258406] kernel BUG at fs/xfs/xfs_message.c:110!
> [  193.260996] invalid opcode: 0000 [#1] SMP PTI
> [  193.263323] CPU: 0 PID: 5613 Comm: xfs_scrub Not tainted 5.5.0-rc3+ #44
> [  193.266717] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014
> [  193.273736] RIP: 0010:assfail+0x23/0x28 [xfs]
> [  193.276045] Code: 67 fc ff ff 0f 0b c3 0f 1f 44 00 00 41 89 c8 48 89 d1 48 89 f2 48 c7 c6 78 e9 8d c0 e8 82 f9 ff ff 80 3d 9a d7 08 00 00 74 02 <0f> 0b 0f 0b c3 48 8b 03 48 c7 c7 68 ee 8d c0 c6 05 0e 2b 0a 00 01
> [  193.284481] RSP: 0018:ffffac9540b7fbe0 EFLAGS: 00010202
> [  193.286297] RAX: 0000000000000000 RBX: ffffac9540b7fcc8 RCX: 0000000000000000
> [  193.288390] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffffc08d144a
> [  193.290235] RBP: ffffac9540b7fbf8 R08: 0000000000000000 R09: 0000000000000000
> [  193.292083] R10: 000000000000000a R11: f000000000000000 R12: 0000000000000000
> [  193.293589] R13: ffff90006701c000 R14: ffff900071746400 R15: ffff900071746558
> [  193.295068] FS:  00007f91892cc740(0000) GS:ffff900078c00000(0000) knlGS:0000000000000000
> [  193.296899] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  193.297977] CR2: 0000000001ef0078 CR3: 0000000236050002 CR4: 00000000003606f0
> [  193.299234] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [  193.300555] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [  193.301805] Call Trace:
> [  193.302296]  xchk_setup_fs+0x35/0x40 [xfs]
> [  193.302937]  xfs_scrub_metadata+0x23d/0x480 [xfs]
> [  193.303658]  xfs_ioc_scrub_metadata+0x50/0xa0 [xfs]
> [  193.304417]  xfs_file_ioctl+0xb23/0xc60 [xfs]
> [  193.305075]  ? pagevec_lru_move_fn+0xbd/0xe0
> [  193.305719]  ? get_kernel_page+0x60/0x60
> [  193.306321]  ? __lru_cache_add+0x62/0x80
> [  193.306922]  ? __handle_mm_fault+0xc65/0x1930
> [  193.307553]  do_vfs_ioctl+0x448/0x6c0
> [  193.308042]  ? handle_mm_fault+0xc4/0x1f0
> [  193.308572]  ksys_ioctl+0x5e/0x90
> [  193.309006]  __x64_sys_ioctl+0x16/0x20
> [  193.309501]  do_syscall_64+0x5b/0x1d0
> [  193.309990]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> 
> > ---
> >  common/dmerror    |  107 +++++++++++++++++++++++++++++++++++++++++-
> >  tests/xfs/747     |  136 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/xfs/747.out |   12 +++++
> >  tests/xfs/748     |  102 ++++++++++++++++++++++++++++++++++++++++
> >  tests/xfs/748.out |    5 ++
> >  tests/xfs/group   |    2 +
> >  6 files changed, 363 insertions(+), 1 deletion(-)
> >  create mode 100755 tests/xfs/747
> >  create mode 100644 tests/xfs/747.out
> >  create mode 100755 tests/xfs/748
> >  create mode 100644 tests/xfs/748.out
> > 
> > 
> > diff --git a/common/dmerror b/common/dmerror
> > index ca1c7335..ee3051f1 100644
> > --- a/common/dmerror
> > +++ b/common/dmerror
> > @@ -62,7 +62,7 @@ _dmerror_load_error_table()
> >  	$DMSETUP_PROG suspend $suspend_opt error-test
> >  	[ $? -ne 0 ] && _fail  "dmsetup suspend failed"
> >  
> > -	$DMSETUP_PROG load error-test --table "$DMERROR_TABLE"
> > +	echo "$DMERROR_TABLE" | $DMSETUP_PROG load error-test
> >  	load_res=$?
> >  
> >  	$DMSETUP_PROG resume error-test
> > @@ -94,3 +94,108 @@ _dmerror_load_working_table()
> >  	[ $load_res -ne 0 ] && _fail "dmsetup failed to load error table"
> >  	[ $resume_res -ne 0 ] && _fail  "dmsetup resume failed"
> >  }
> > +
> > +# Given a list of (start, length) tuples on stdin, combine adjacent tuples into
> > +# larger ones and write the new list to stdout.
> > +__dmerror_combine_extents()
> > +{
> > +	awk 'BEGIN{start = 0; len = 0;}{
> 
> $AWK_PROG

Fixed all of these.

> 
> > +if (start + len == $1) {
> > +	len += $2;
> > +} else {
> > +	if (len > 0)
> > +		printf("%d %d\n", start, len);
> > +	start = $1;
> > +	len = $2;
> > +}
> > +} END {
> > +	if (len > 0)
> > +		printf("%d %d\n", start, len);
> > +}'
> > +}
> > +
> > +# Given a block device, the name of a preferred dm target, the name of an
> > +# implied dm target, and a list of (start, len) tuples on stdin, create a new
> > +# dm table which maps each of the tuples to the preferred target and all other
> > +# areas to the implied dm target.
> > +__dmerror_recreate_map()
> > +{
> > +	local device="$1"
> > +	local preferred_tgt="$2"
> > +	local implied_tgt="$3"
> > +	local size=$(blockdev --getsz "$device")
> > +
> > +	awk -v device="$device" -v size=$size -v implied_tgt="$implied_tgt" \
> 
> Same here.
> 
> > +		-v preferred_tgt="$preferred_tgt" 'BEGIN{implied_start = 0;}{
> > +	extent_start = $1;
> > +	extent_len = $2;
> > +
> > +	if (extent_start > size) {
> > +		extent_start = size;
> > +		extent_len = 0;
> > +	} else if (extent_start + extent_len > size) {
> > +		extent_len = size - extent_start;
> > +	}
> > +
> > +	if (implied_start < extent_start)
> > +		printf("%d %d %s %s %d\n", implied_start,
> > +				extent_start - implied_start, implied_tgt,
> > +				device, implied_start);
> > +	printf("%d %d %s %s %d\n", extent_start, extent_len, preferred_tgt,
> > +			device, extent_start);
> > +	implied_start = extent_start + extent_len;
> > +}END{
> > +	if (implied_start < size)
> > +		printf("%d %d %s %s %d\n", implied_start, size - implied_start,
> > +				implied_tgt, device, implied_start);
> > +}'
> > +}
> > +
> > +# Update the dm error table so that the range (start, len) maps to the
> > +# preferred dm target, overriding anything that maps to the implied dm target.
> > +# This assumes that the only desired targets for this dm device are the
> > +# preferred and and implied targets.  The optional fifth argument can be used
> > +# to change the underlying device.
> > +__dmerror_change()
> > +{
> > +	local start="$1"
> > +	local len="$2"
> > +	local preferred_tgt="$3"
> > +	local implied_tgt="$4"
> > +	local dm_backing_dev="$5"
> > +	test -z "$dm_backing_dev" && dm_backing_dev="$SCRATCH_DEV"
> > +
> > +	DMERROR_TABLE="$( (echo "$DMERROR_TABLE"; echo "$start $len $preferred_tgt") | \
> > +		awk -v type="$preferred_tgt" '{if ($3 == type) print $0;}' | \
> 
> Same here.
> 
> > +		sort -g | \
> > +		__dmerror_combine_extents | \
> > +		__dmerror_recreate_map "$dm_backing_dev" "$preferred_tgt" \
> > +				"$implied_tgt" )"
> > +}
> > +
> > +# Reset the dm error table to everything ok.  The dm device itself must be
> > +# remapped by calling _dmerror_load_error_table.
> > +_dmerror_reset_table()
> > +{
> > +	DMERROR_TABLE="$DMLINEAR_TABLE"
> > +}
> > +
> > +# Update the dm error table so that IOs to the given range will return EIO.
> > +# The dm device itself must be remapped by calling _dmerror_load_error_table.
> > +_dmerror_mark_range_bad()
> > +{
> > +	local start="$1"
> > +	local len="$2"
> > +
> > +	__dmerror_change "$start" "$len" error linear
> > +}
> > +
> > +# Update the dm error table so that IOs to the given range will succeed.
> > +# The dm device itself must be remapped by calling _dmerror_load_error_table.
> > +_dmerror_mark_range_good()
> > +{
> > +	local start="$1"
> > +	local len="$2"
> > +
> > +	__dmerror_change "$start" "$len" linear error
> > +}
> > diff --git a/tests/xfs/747 b/tests/xfs/747
> > new file mode 100755
> > index 00000000..f5894411
> > --- /dev/null
> > +++ b/tests/xfs/747
> > @@ -0,0 +1,136 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0-or-newer
> > +# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
> > +#
> > +# FS QA Test No. 747
> > +#
> > +# Check xfs_scrub's media scan can actually return diagnostic information for
> > +# media errors in file data extents.
> > +
> > +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.error
> 
> 	rm -f $tmp.*
> 
> would be find. Otherwise files like $tmp.mkfs are still there.

Fixed this too.

> > +	_dmerror_cleanup
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/fuzzy
> > +. ./common/filter
> > +. ./common/dmerror
> > +
> > +# real QA test starts here
> > +_supported_fs xfs
> > +_supported_os Linux
> > +_require_dm_target error
> > +_require_scratch_xfs_crc
> > +_require_scrub
> > +
> > +rm -f $seqres.full
> > +
> > +filter_scrub_errors() {
> > +	_filter_scratch | sed -e "s/offset $((blksz * 2)) /offset 2FSB /g" \
> > +		-e "s/length $blksz.*/length 1FSB./g"
> > +}
> > +
> > +_scratch_mkfs > $tmp.mkfs
> > +_dmerror_init
> > +_dmerror_mount >> $seqres.full 2>&1
> > +
> > +_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
> > +
> > +victim=$SCRATCH_MNT/a
> > +$XFS_IO_PROG -f -c "pwrite -S 0x58 0 1m" -c "fsync" $victim >> $seqres.full
> > +bmap_str="$($XFS_IO_PROG -c "bmap -elpv" $victim | grep "^[[:space:]]*0:")"
> > +echo "$bmap_str" >> $seqres.full
> > +
> > +phys="$(echo "$bmap_str" | awk '{print $3}')"
> > +len="$(echo "$bmap_str" | awk '{print $6}')"
> > +blksz=$(_get_file_block_size $SCRATCH_MNT)
> > +sectors_per_block=$((blksz / 512))
> > +
> > +# Did we get at least 4 fs blocks worth of extent?
> > +min_len_sectors=$(( 4 * sectors_per_block ))
> > +test "$len" -lt $min_len_sectors && \
> > +	_fail "could not format a long enough extent on an empty fs??"
> > +
> > +phys_start=$(echo "$phys" | sed -e 's/\.\..*//g')
> > +
> > +
> > +echo ":$phys:$len:$blksz:$phys_start" >> $seqres.full
> > +echo "victim file:" >> $seqres.full
> > +od -tx1 -Ad -c $victim >> $seqres.full
> > +
> > +# Reset the dmerror table so that all IO will pass through.
> > +_dmerror_reset_table
> > +
> > +cat >> $seqres.full << ENDL
> > +dmerror before:
> > +$DMERROR_TABLE
> > +<end table>
> > +ENDL
> > +
> > +# Now mark /only/ the middle of the extent bad.
> > +_dmerror_mark_range_bad $(( phys_start + (2 * sectors_per_block) + 1 )) 1
> > +
> > +cat >> $seqres.full << ENDL
> > +dmerror after marking bad:
> > +$DMERROR_TABLE
> > +<end table>
> > +ENDL
> > +
> > +_dmerror_load_error_table
> > +
> > +# See if the media scan picks it up.
> > +echo "Scrub for injected media error (single threaded)"
> > +
> > +# Once in single-threaded mode
> > +_scratch_scrub -b -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# Once in parallel mode
> > +echo "Scrub for injected media error (multi threaded)"
> > +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# Remount to flush the page cache and reread to see the IO error
> > +_dmerror_unmount
> > +_dmerror_mount
> > +echo "victim file:" >> $seqres.full
> > +od -tx1 -Ad -c $victim >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | _filter_scratch
> > +
> > +# Scrub again to re-confirm the media error across a remount
> > +echo "Scrub for injected media error (after remount)"
> > +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# Now mark the bad range good.
> > +_dmerror_mark_range_good $(( phys_start + (2 * sectors_per_block) + 1 )) 1
> > +_dmerror_load_error_table
> > +
> > +cat >> $seqres.full << ENDL
> > +dmerror after marking good:
> > +$DMERROR_TABLE
> > +<end table>
> > +ENDL
> > +
> > +echo "Scrub after removing injected media error"
> > +
> > +# Scrub one last time to make sure the error's gone.
> > +_scratch_scrub -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/xfs/747.out b/tests/xfs/747.out
> > new file mode 100644
> > index 00000000..f85f1753
> > --- /dev/null
> > +++ b/tests/xfs/747.out
> > @@ -0,0 +1,12 @@
> > +QA output created by 747
> > +Scrub for injected media error (single threaded)
> > +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> > +SCRATCH_MNT: unfixable errors found: 1
> > +Scrub for injected media error (multi threaded)
> > +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> > +SCRATCH_MNT: unfixable errors found: 1
> > +od: SCRATCH_MNT/a: read error: Input/output error
> > +Scrub for injected media error (after remount)
> > +Unfixable Error: SCRATCH_MNT/a: media error at data offset 2FSB length 1FSB.
> > +SCRATCH_MNT: unfixable errors found: 1
> > +Scrub after removing injected media error
> > diff --git a/tests/xfs/748 b/tests/xfs/748
> > new file mode 100755
> > index 00000000..130cc6f2
> > --- /dev/null
> > +++ b/tests/xfs/748
> > @@ -0,0 +1,102 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0-or-newer
> > +# Copyright (c) 2019, Oracle and/or its affiliates.  All Rights Reserved.
> > +#
> > +# FS QA Test No. 748
> > +#
> > +# Check xfs_scrub's media scan can actually return diagnostic information for
> > +# media errors in filesystem metadata.
> > +
> > +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.error $tmp.fsmap
> 
> rm -f $tmp.*
> 
> > +	_dmerror_cleanup
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/fuzzy
> > +. ./common/filter
> > +. ./common/dmerror
> > +
> > +# real QA test starts here
> > +_supported_fs xfs
> > +_supported_os Linux
> > +_require_dm_target error
> > +_require_xfs_scratch_rmapbt
> 
> Add a comment on why rmapbt is needed?

"rmapbt is required to enable reporting of what metadata was lost."

--D

> Thanks,
> Eryu
> 
> > +_require_scrub
> > +
> > +rm -f $seqres.full
> > +
> > +filter_scrub_errors() {
> > +	_filter_scratch | sed -e "s/disk offset [0-9]*: /disk offset NNN: /g" \
> > +		-e "/errors found:/d" -e 's/phase6.c line [0-9]*/!/g' \
> > +		-e "/corruptions found:/d" | uniq
> > +}
> > +
> > +_scratch_mkfs > $tmp.mkfs
> > +_dmerror_init
> > +_dmerror_mount >> $seqres.full 2>&1
> > +
> > +_supports_xfs_scrub $SCRATCH_MNT $SCRATCH_DEV || _notrun "Scrub not supported"
> > +
> > +# Create a bunch of metadata so that we can mark them bad in the next step.
> > +victim=$SCRATCH_MNT/a
> > +$FSSTRESS_PROG -z -n 200 -p 10 \
> > +	       -f creat=10 \
> > +	       -f resvsp=1 \
> > +	       -f truncate=1 \
> > +	       -f punch=1 \
> > +	       -f chown=5 \
> > +	       -f mkdir=5 \
> > +	       -f mknod=1 \
> > +	       -d $victim >> $seqres.full 2>&1
> > +
> > +# Mark all the metadata bad
> > +_dmerror_reset_table
> > +$XFS_IO_PROG -c "fsmap -n100 -vvv" $victim | grep inodes > $tmp.fsmap
> > +while read a b c crap; do
> > +	phys="$(echo $c | sed -e 's/^.\([0-9]*\)\.\.\([0-9]*\).*$/\1:\2/g')"
> > +	target_begin="$(echo "$phys" | cut -d ':' -f 1)"
> > +	target_end="$(echo "$phys" | cut -d ':' -f 2)"
> > +
> > +	_dmerror_mark_range_bad $target_begin $((target_end - target_begin))
> > +done < $tmp.fsmap
> > +cat $tmp.fsmap >> $seqres.full
> > +
> > +cat >> $seqres.full << ENDL
> > +dmerror after marking bad:
> > +$DMERROR_TABLE
> > +<end table>
> > +ENDL
> > +
> > +_dmerror_load_error_table
> > +
> > +# See if the media scan picks it up.
> > +echo "Scrub for injected media error"
> > +
> > +XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# Make the disk work again
> > +_dmerror_load_working_table
> > +
> > +echo "Scrub after removing injected media error"
> > +
> > +# Scrub one last time to make sure the error's gone.
> > +XFS_SCRUB_PHASE=6 _scratch_scrub -x >> $seqres.full 2> $tmp.error
> > +cat $tmp.error | filter_scrub_errors
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/xfs/748.out b/tests/xfs/748.out
> > new file mode 100644
> > index 00000000..49dc2d7a
> > --- /dev/null
> > +++ b/tests/xfs/748.out
> > @@ -0,0 +1,5 @@
> > +QA output created by 748
> > +Scrub for injected media error
> > +Corruption: disk offset NNN: media error in inodes. (!)
> > +SCRATCH_MNT: Unmount and run xfs_repair.
> > +Scrub after removing injected media error
> > diff --git a/tests/xfs/group b/tests/xfs/group
> > index 18a593d9..3a58864b 100644
> > --- a/tests/xfs/group
> > +++ b/tests/xfs/group
> > @@ -509,3 +509,5 @@
> >  510 auto ioctl quick
> >  511 auto quick quota
> >  741 auto quick rw
> > +747 auto quick scrub
> > +748 auto quick scrub
> >