Re: [PATCH v2] fstests: generic: Check if a bull fallocate will change extent number

Eryu Guan
2015-09-29T09:55:51Z

On Tue, Sep 29, 2015 at 05:34:24PM +0800, Qu Wenruo wrote:
> Normally, a bull fallocate call on a fully written and synced file
> should not add an extent.
>
> But not all filesystem follows the correct behavior.
>
> Btrfs has a bug to always truncate the last page if the fallocate start
> offset is smaller than inode size.
>
> So add this test case to detect such malfunction.
>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
> v2:
> Add author info...
> Fix some comment typo

(I was going to point these out then saw a v2 :)

> ---
> tests/generic/110 | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
> tests/generic/110.out | 3 ++
> tests/generic/group | 1 +
> 3 files changed, 82 insertions(+)
> create mode 100755 tests/generic/110
> create mode 100644 tests/generic/110.out
>
> diff --git a/tests/generic/110 b/tests/generic/110
> new file mode 100755
> index 0000000..b2b140c
> --- /dev/null
> +++ b/tests/generic/110
> @@ -0,0 +1,78 @@
> +#! /bin/bash
> +# FS QA Test 110
> +#
> +# Test if fallocate will create uneeded extra tailing extent
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2015 Fujitsu. All Rights Reserved.
> +#
> +# 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"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1 # failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> + cd /
> + rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +. ./common/defrag
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +# real QA test starts here
> +
> +_supported_fs generic
> +_supported_os IRIX Linux
> +_require_scratch
> +_need_to_be_root

need a '_require_xfs_io_command "falloc"' here, so test _notrun
correctly on ext2/3/NFS/CIFS that don't support fallocate.

> +
> +# Use 64K file size to match any sectorsize
> +# And with a unaligned tailing range to ensure it will be at least 2 pages
> +filesize=$(( 64 * 1024 + 1024 ))
> +
> +_scratch_mkfs > /dev/null 2>&1
> +_scratch_mount
> +$XFS_IO_PROG -f -c "pwrite 0 $filesize" $SCRATCH_MNT/foo | _filter_xfs_io
> +sync
> +orig_extent_nr=`_extent_count $SCRATCH_MNT/foo`
> +
> +# As all space are allocated and even written to disk, this falloc
> +# should do nothing with extent modification.
> +$XFS_IO_PROG -f -c "falloc 0 $filesize" $SCRATCH_MNT/foo
> +sync
> +new_extent_nr=`_extent_count $SCRATCH_MNT/foo`
> +
> +echo "orig: $orig_extent_nr, new: $new_extent_nr" >> $seqres.full
> +
> +if [ "x$orig_extent_nr" != "x$new_extent_nr" ]; then
> + echo "number of extents mis-match after bull fallocate"

print out the $orig_extent_nr and $new_extent_nr in this failure case? I
think it's useful to see the difference just from the output diff, don't
have to check the full file.

Thanks,
Eryu

> +fi
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/generic/110.out b/tests/generic/110.out
> new file mode 100644
> index 0000000..64049da
> --- /dev/null
> +++ b/tests/generic/110.out
> @@ -0,0 +1,3 @@
> +QA output created by 110
> +wrote 66560/66560 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> diff --git a/tests/generic/group b/tests/generic/group
> index 4ae256f..428f3e3 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -112,6 +112,7 @@
> 107 auto quick metadata
> 108 auto quick rw
> 109 auto metadata dir
> +110 auto quick prealloc
> 112 rw aio auto quick
> 113 rw aio auto quick
> 117 attr auto quick
> --
> 1.8.3.1
>
> --
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