On Thu, Jul 09, 2015 at 03:51:13PM +0100, fdmanana@xxxxxxxxxx wrote:
> From: Filipe Manana <fdmanana@xxxxxxxx>
>
> 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 (which always happens at
> transaction commit time) does not fail.
>
> The regression was introduced in the 4.2-rc1 Linux kernel and fixed by
> the patch titled: "Btrfs: fix order by which delayed references are run".
>
> Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
> ---
> tests/btrfs/095 | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/btrfs/095.out | 9 ++++
> tests/btrfs/group | 1 +
> 3 files changed, 163 insertions(+)
> create mode 100755 tests/btrfs/095
> create mode 100644 tests/btrfs/095.out
>
> diff --git a/tests/btrfs/095 b/tests/btrfs/095
> new file mode 100755
> index 0000000..e68f2bf
> --- /dev/null
> +++ b/tests/btrfs/095
> @@ -0,0 +1,153 @@
> +#! /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 <fdmanana@xxxxxxxx>
> +#
> +# 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
> +
> +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" $SCRATCH_MNT/foo
You're using falloc, so I think you need _require_xfs_io_command "falloc".
Otherwise,
Reviewed-by: Omar Sandoval <osandov@xxxxxx>
> +
> +# Now write to the last 80K of the prealloc extent plus 40K to the unallocated
> +# space that immediately follows it. This creates a new extent of 40K that spans
> +# the range [620K, 660K[.
> +$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" $SCRATCH_MNT/foo | _filter_xfs_io
> +
> +# At this point, there are now (in memory) 4 back references to the prealloc
> +# extent.
> +#
> +# Two of them are for file offset 160K, related to file extent items
> +# matching the file offsets 160K and 540K respectively, with data offsets of
> +# 0 and 380K respectively, and with lengths of 380K and 80K respectively.
> +#
> +# The other two references are for file offset 2M, related to file extent items
> +# matching the file offsets 2M and 2M + 380K respectively, with data offsets of
> +# 0 and 380K respectively, and with lengths of 389K and 80K respectively.
> +#
> +# The 40K extent has 2 back references, one for file offset 620K and the other
> +# for file offset 2M + 460K.
> +#
> +# The 100K extent has a single back reference and it relates to file offset 3M.
> +
> +# Now clone our 100K extent into offset 600K. That offset covers the last 20K
> +# of the prealloc extent, the whole 40K extent and 40K of the hole starting at
> +# offset 660K.
> +$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 0000000..e93435c
> --- /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 ffe18bf..79feea9 100644
> --- a/tests/btrfs/group
> +++ b/tests/btrfs/group
> @@ -96,3 +96,4 @@
> 092 auto quick send
> 093 auto quick clone
> 094 auto quick send
> +095 auto quick metadata
> --
> 2.1.3
>
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--
Omar
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