[PATCH 2/3] fstests: btrfs/14[23]: Use proper help to get both devid and physical offset for corruption.

Qu Wenruo
2019-12-11T10:40:50Z

[BUG]
When using btrfs-progs v5.4, btrfs/142 and btrfs/143 will fail:
btrfs/142 1s ... - output mismatch (see xfstests/results//btrfs/142.out.bad)
--- tests/btrfs/142.out 2018-09-16 21:30:48.505104287 +0100
+++ xfstests/results//btrfs/142.out.bad
2019-12-10 15:35:40.280392626 +0000
@@ -3,37 +3,37 @@
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
wrote 65536/65536 bytes
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
-XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
-XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
-XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
...
(Run 'diff -u xfstests/tests/btrfs/142.out xfstests/results//btrfs/142.out.bad' to see the entire diff)

[CAUSE]
Btrfs/14[23] test whether a read on corrupted stripe will re-silver
itself.
Such test by its nature will need to modify on-disk data, thus need to
get the btrfs logical -> physical mapping, which is done by near
hard-coded lookup function, which rely on certain stripe:devid sequence.

Recent btrfs-progs commit c501c9e3b816 ("btrfs-progs: mkfs: match devid
order to the stripe index") changes how we use devices in mkfs.btrfs,
this caused a change in chunk layout, and break the hard-coded
stripe:devid sequence.

[FIX]
This patch will do full devid and physical offset lookup, instead of old
physical offset only lookup.

The only assumption made is, mkfs.btrfs assigns devid sequentially for
its devices.
Which means, for "mkfs.btrfs $dev1 $dev2 $dev3", we get devid 1 for $dev1,
devid 2 for $dev2, and so on.

This change will allow btrfs/14[23] to handle even future chunk layout
change. (Although I hope this will never happen again).

This also addes extra debug output (although less than 10 lines) into
$seqres.full, just in case when layout changes and current lookup can't
handle it, developer can still pindown the problem easily.

Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
---
tests/btrfs/142 | 50 +++++++++++++++++++++++++++++++--------------
tests/btrfs/142.out | 2 --
tests/btrfs/143 | 48 +++++++++++++++++++++++++++++++------------
tests/btrfs/143.out | 2 --
4 files changed, 70 insertions(+), 32 deletions(-)

diff --git a/tests/btrfs/142 b/tests/btrfs/142
index a23fe1bf..9c037ff6 100755
--- a/tests/btrfs/142
+++ b/tests/btrfs/142
@@ -47,30 +47,45 @@ _require_command "$FILEFRAG_PROG" filefrag

get_physical()
{
- # $1 is logical address
- # print chunk tree and find devid 2 which is $SCRATCH_DEV
+ local logical=$1
+ local stripe=$2
$BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | \
- grep $1 -A 6 | awk '($1 ~ /stripe/ && $3 ~ /devid/ && $4 ~ /1/) { print $6 }'
+ grep $logical -A 6 | \
+ awk "(\$1 ~ /stripe/ && \$3 ~ /devid/ && \$2 ~ /$stripe/) { print \$6 }"
}

+get_devid()
+{
+ local logical=$1
+ local stripe=$2
+ $BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | \
+ grep $logical -A 6 | \
+ awk "(\$1 ~ /stripe/ && \$3 ~ /devid/ && \$2 ~ /$stripe/) { print \$4 }"
+}

-SYSFS_BDEV=`_sysfs_dev $SCRATCH_DEV`
+get_device_path()
+{
+ local devid=$1
+ echo "$SCRATCH_DEV_POOL" | awk "{print \$$devid}"
+}

start_fail()
{
+ local sysfs_bdev="$1"
echo 100 > $DEBUGFS_MNT/fail_make_request/probability
echo 2 > $DEBUGFS_MNT/fail_make_request/times
echo 1 > $DEBUGFS_MNT/fail_make_request/task-filter
echo 0 > $DEBUGFS_MNT/fail_make_request/verbose
- echo 1 > $SYSFS_BDEV/make-it-fail
+ echo 1 > $sysfs_bdev/make-it-fail
}

stop_fail()
{
+ local sysfs_bdev="$1"
echo 0 > $DEBUGFS_MNT/fail_make_request/probability
echo 0 > $DEBUGFS_MNT/fail_make_request/times
echo 0 > $DEBUGFS_MNT/fail_make_request/task-filter
- echo 0 > $SYSFS_BDEV/make-it-fail
+ echo 0 > $sysfs_bdev/make-it-fail
}

_scratch_dev_pool_get 2
@@ -87,17 +102,23 @@ _scratch_mount -o nospace_cache,nodatasum
$XFS_IO_PROG -f -d -c "pwrite -S 0xaa -b 128K 0 128K" "$SCRATCH_MNT/foobar" |\
_filter_xfs_io_offset

-# step 2, corrupt the first 64k of one copy (on SCRATCH_DEV which is the first
-# one in $SCRATCH_DEV_POOL
+# step 2, corrupt the first 64k of stripe #1
echo "step 2......corrupt file extent" >>$seqres.full

${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar >> $seqres.full
logical_in_btrfs=`${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar | _filter_filefrag | cut -d '#' -f 1`
-physical_on_scratch=`get_physical ${logical_in_btrfs}`
+physical=`get_physical ${logical_in_btrfs} 1`
+devid=$(get_devid ${logical_in_btrfs} 1)
+target_dev=$(get_device_path $devid)
+
+SYSFS_BDEV=`_sysfs_dev $target_dev`

_scratch_unmount
-$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical_on_scratch 64K" $SCRATCH_DEV |\
- _filter_xfs_io_offset
+$BTRFS_UTIL_PROG ins dump-tree -t 3 $SCRATCH_DEV | \
+ grep $logical_in_btrfs -A 6 >> $seqres.full
+echo "Corrupt stripe 1 devid $devid devpath $target_dev physical $physical" \
+ >> $seqres.full
+$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical 64K" $target_dev > /dev/null

_scratch_mount -o nospace_cache

@@ -106,8 +127,7 @@ echo "step 3......repair the bad copy" >>$seqres.full

# since raid1 consists of two copies, and the bad copy was put on stripe #1
# while the good copy lies on stripe #0, the bad copy only gets access when the
-# reader's pid % 2 == 1 is true
-start_fail
+start_fail $SYSFS_BDEV
while [[ -z ${result} ]]; do
# enable task-filter only fails the following dio read so the repair is
# supposed to work.
@@ -117,12 +137,12 @@ while [[ -z ${result} ]]; do
exec $XFS_IO_PROG -d -c \"pread -b 128K 0 128K\" \"$SCRATCH_MNT/foobar\"
fi");
done
-stop_fail
+stop_fail $SYSFS_BDEV

_scratch_unmount

# check if the repair works
-$XFS_IO_PROG -c "pread -v -b 512 $physical_on_scratch 512" $SCRATCH_DEV |\
+$XFS_IO_PROG -c "pread -v -b 512 $physical 512" $target_dev | \
_filter_xfs_io_offset

_scratch_dev_pool_put
diff --git a/tests/btrfs/142.out b/tests/btrfs/142.out
index 0f32ffbe..2e22f292 100644
--- a/tests/btrfs/142.out
+++ b/tests/btrfs/142.out
@@ -1,8 +1,6 @@
QA output created by 142
wrote 131072/131072 bytes
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-wrote 65536/65536 bytes
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
diff --git a/tests/btrfs/143 b/tests/btrfs/143
index 91af52f9..b2ffeb63 100755
--- a/tests/btrfs/143
+++ b/tests/btrfs/143
@@ -54,30 +54,48 @@ _require_command "$FILEFRAG_PROG" filefrag

get_physical()
{
- # $1 is logical address
- # print chunk tree and find devid 2 which is $SCRATCH_DEV
+ local logical=$1
+ local stripe=$2
$BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | \
- grep $1 -A 6 | awk '($1 ~ /stripe/ && $3 ~ /devid/ && $4 ~ /1/) { print $6 }'
+ grep $logical -A 6 | \
+ awk "(\$1 ~ /stripe/ && \$3 ~ /devid/ && \$2 ~ /$stripe/) { print \$6 }"
+}
+
+get_devid()
+{
+ local logical=$1
+ local stripe=$2
+ $BTRFS_UTIL_PROG inspect-internal dump-tree -t 3 $SCRATCH_DEV | \
+ grep $logical -A 6 | \
+ awk "(\$1 ~ /stripe/ && \$3 ~ /devid/ && \$2 ~ /$stripe/) { print \$4 }"
+}
+
+get_device_path()
+{
+ local devid=$1
+ echo "$SCRATCH_DEV_POOL" | awk "{print \$$devid}"
}

SYSFS_BDEV=`_sysfs_dev $SCRATCH_DEV`

start_fail()
{
+ local sysfs_bdev="$1"
echo 100 > $DEBUGFS_MNT/fail_make_request/probability
# the 1st one fails the first bio which is reading 4k (or more due to
# readahead), and the 2nd one fails the retry of validation so that it
# triggers read-repair
echo 2 > $DEBUGFS_MNT/fail_make_request/times
echo 0 > $DEBUGFS_MNT/fail_make_request/verbose
- echo 1 > $SYSFS_BDEV/make-it-fail
+ echo 1 > $sysfs_bdev/make-it-fail
}

stop_fail()
{
+ local sysfs_bdev="$1"
echo 0 > $DEBUGFS_MNT/fail_make_request/probability
echo 0 > $DEBUGFS_MNT/fail_make_request/times
- echo 0 > $SYSFS_BDEV/make-it-fail
+ echo 0 > $sysfs_bdev/make-it-fail
}

_scratch_dev_pool_get 2
@@ -94,17 +112,21 @@ _scratch_mount -o nospace_cache,nodatasum
$XFS_IO_PROG -f -d -c "pwrite -S 0xaa -b 128K 0 128K" "$SCRATCH_MNT/foobar" |\
_filter_xfs_io_offset

-# step 2, corrupt the first 64k of one copy (on SCRATCH_DEV which is the first
-# one in $SCRATCH_DEV_POOL
+# step 2, corrupt the first 64k of stripe #1
echo "step 2......corrupt file extent" >>$seqres.full

${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar >> $seqres.full
logical_in_btrfs=`${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar | _filter_filefrag | cut -d '#' -f 1`
-physical_on_scratch=`get_physical ${logical_in_btrfs}`
+physical=`get_physical ${logical_in_btrfs} 1`
+devid=$(get_devid ${logical_in_btrfs} 1)
+target_dev=$(get_device_path $devid)

+SYSFS_BDEV=`_sysfs_dev $target_dev`
_scratch_unmount
-$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical_on_scratch 64K" $SCRATCH_DEV |\
- _filter_xfs_io_offset
+
+echo "corrupt stripe 1 devid $devid devpath $target_dev physical $physical" \
+ >> $seqres.full
+$XFS_IO_PROG -d -c "pwrite -S 0xbb -b 64K $physical 64K" $target_dev > /dev/null

_scratch_mount -o nospace_cache

@@ -118,18 +140,18 @@ while [[ -z ${result} ]]; do
# invalidate the page cache.
_scratch_cycle_mount

- start_fail
+ start_fail $SYSFS_BDEV
result=$(bash -c "
if [[ \$((\$\$ % 2)) -eq 1 ]]; then
exec $XFS_IO_PROG -c \"pread 0 4K\" \"$SCRATCH_MNT/foobar\"
fi");
- stop_fail
+ stop_fail $SYSFS_BDEV
done

_scratch_unmount

# check if the repair works
-$XFS_IO_PROG -c "pread -v -b 512 $physical_on_scratch 512" $SCRATCH_DEV |\
+$XFS_IO_PROG -c "pread -v -b 512 $physical 512" $target_dev |\
_filter_xfs_io_offset

_scratch_dev_pool_put
diff --git a/tests/btrfs/143.out b/tests/btrfs/143.out
index 66afea4b..a9e82ceb 100644
--- a/tests/btrfs/143.out
+++ b/tests/btrfs/143.out
@@ -1,8 +1,6 @@
QA output created by 143
wrote 131072/131072 bytes
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-wrote 65536/65536 bytes
-XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
XXXXXXXX: aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa ................
--
2.23.0