diff --git a/tests/btrfs/095 b/tests/btrfs/095 new file mode 100755 index 00000000..032d1ffe --- /dev/null +++ b/tests/btrfs/095 @@ -0,0 +1,154 @@ +#! /bin/bash +# FSQA Test No. 095 +# +# Regression test for adding and dropping an equal number of references for +# file extents. Verify that if we drop N references for a file extent and we +# add too N new references for that same file extent in the same transaction, +# running the delayed references (always happens at transaction commit time) +# does not fail. +# +# The regression was introduced in the 4.2-rc1 Linux kernel. +# +#----------------------------------------------------------------------- +# +# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved. +# Author: Filipe Manana +# +# This program is free software; you can redistribute it and/or +# modify it under the terms of the GNU General Public License as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it would be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write the Free Software Foundation, +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +#----------------------------------------------------------------------- +# + +seq=`basename $0` +seqres=$RESULT_DIR/$seq +echo "QA output created by $seq" +tmp=/tmp/$$ +status=1 # failure is the default! +trap "_cleanup; exit \$status" 0 1 2 3 15 + +_cleanup() +{ + _cleanup_flakey + rm -f $tmp.* +} + +# get standard environment, filters and checks +. ./common/rc +. ./common/filter +. ./common/dmflakey + +# real QA test starts here +_need_to_be_root +_supported_fs btrfs +_supported_os Linux +_require_scratch +_require_dm_flakey +_require_cloner +_require_metadata_journaling $SCRATCH_DEV +_require_xfs_io_command "falloc" + +rm -f $seqres.full + +_scratch_mkfs >>$seqres.full 2>&1 +_init_flakey +_mount_flakey + +# Create prealloc extent covering range [160K, 620K[ +$XFS_IO_PROG -f -c "falloc 160K 460K" $SCRATCH_MNT/foo + +# Now write to the last 80K of the prealloc extent plus 40K to the unallocated +# space that immediately follows it. This creates a new extent of 40K that spans +# the range [620K, 660K[. +$XFS_IO_PROG -c "pwrite -S 0xaa 540K 120K" $SCRATCH_MNT/foo | _filter_xfs_io + +# At this point, there are now 2 back references to the prealloc extent in our +# extent tree. Both are for our file offset 160K and one relates to a file +# extent item with a data offset of 0 and a length of 380K, while the other +# relates to a file extent item with a data offset of 380K and a length of 80K. + +# Make sure everything done so far is durably persisted (all back references are +# in the extent tree, etc). +sync + +# Now clone all extents of our file that cover the offset 160K up to its eof +# (660K at this point) into itself at offset 2M. This leaves a hole in the file +# covering the range [660K, 2M[. The prealloc extent will now be referenced by +# the file twice, once for offset 160K and once for offset 2M. The 40K extent +# that follows the prealloc extent will also be referenced twice by our file, +# once for offset 620K and once for offset 2M + 460K. +$CLONER_PROG -s $((160 * 1024)) -d $((2 * 1024 * 1024)) -l 0 $SCRATCH_MNT/foo \ + $SCRATCH_MNT/foo + +# Now create one new extent in our file with a size of 100Kb. It will span the +# range [3M, 3M + 100K[. It also will cause creation of a hole spanning the +# range [2M + 460K, 3M[. Our new file size is 3M + 100K. +$XFS_IO_PROG -c "pwrite -S 0xbb 3M 100K" $SCRATCH_MNT/foo | _filter_xfs_io + +# At this point, there are now (in memory) 4 back references to the prealloc +# extent. +# +# Two of them are for file offset 160K, related to file extent items +# matching the file offsets 160K and 540K respectively, with data offsets of +# 0 and 380K respectively, and with lengths of 380K and 80K respectively. +# +# The other two references are for file offset 2M, related to file extent items +# matching the file offsets 2M and 2M + 380K respectively, with data offsets of +# 0 and 380K respectively, and with lengths of 380K and 80K respectively. +# +# The 40K extent has 2 back references, one for file offset 620K and the other +# for file offset 2M + 460K. +# +# The 100K extent has a single back reference and it relates to file offset 3M. + +# Now clone our 100K extent into offset 600K. That offset covers the last 20K +# of the prealloc extent, the whole 40K extent and 40K of the hole starting at +# offset 660K. +$CLONER_PROG -s $((3 * 1024 * 1024)) -d $((600 * 1024)) -l $((100 * 1024)) \ + $SCRATCH_MNT/foo $SCRATCH_MNT/foo + +# At this point there's only one reference to the 40K extent, at file offset +# 2M + 460K, we have 4 references for the prealloc extent (2 for file offset +# 160K and 2 for file offset 2M) and 2 references for the 100K extent (1 for +# file offset 3M and a new one for file offset 600K). + +# Now fsync our file to make all its new data and metadata updates are durably +# persisted and present if a power failure/crash happens after a successful +# fsync and before the next transaction commit. +$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo + +echo "File digest before power failure:" +md5sum $SCRATCH_MNT/foo | _filter_scratch + +# Silently drop all writes and ummount to simulate a crash/power failure. +_load_flakey_table $FLAKEY_DROP_WRITES +_unmount_flakey + +# Allow writes again, mount to trigger log replay and validate file contents. +# During log replay, the btrfs delayed references implementation used to run the +# deletion of back references before the addition of new back references, which +# made the addition fail as it didn't find the key in the extent tree that it +# was looking for. The failure triggered by this test was related to the 40K +# extent, which got 1 reference dropped and 1 reference added during the fsync +# log replay - when running the delayed references at transaction commit time, +# btrfs was applying the deletion before the insertion, resulting in a failure +# of the insertion that ended up turning the fs into read-only mode. +_load_flakey_table $FLAKEY_ALLOW_WRITES +_mount_flakey + +echo "File digest after log replay:" +md5sum $SCRATCH_MNT/foo | _filter_scratch + +_unmount_flakey + +status=0 +exit diff --git a/tests/btrfs/095.out b/tests/btrfs/095.out new file mode 100644 index 00000000..e93435cd --- /dev/null +++ b/tests/btrfs/095.out @@ -0,0 +1,9 @@ +QA output created by 095 +wrote 122880/122880 bytes at offset 552960 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +wrote 102400/102400 bytes at offset 3145728 +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) +File digest before power failure: +beaf47c36659ac29bb9363fb8ffa10a1 SCRATCH_MNT/foo +File digest after log replay: +beaf47c36659ac29bb9363fb8ffa10a1 SCRATCH_MNT/foo diff --git a/tests/btrfs/group b/tests/btrfs/group index 616d0607..a5c03d39 100644 --- a/tests/btrfs/group +++ b/tests/btrfs/group @@ -97,3 +97,4 @@ 092 auto quick send 093 auto quick clone 094 auto quick send +095 auto quick metadata