Re: [PATCH 4/5] generic: add mmap write vs truncate/remap test

[Eric Sandeen <sandeen@sandeen.net>]

On 9/16/14 8:41 PM, Dave Chinner wrote:
> This test exposed a problem with mapped writes to the tail page of a
> file in XFS and potentially ext4. Eric did all the hard work of
> taking the bug report and generating the reproducable test case
> on ext4, but I haven't been able to reproduce then problem on ext4.
> 
> Regardless, make it a generic test so that we can ensure that all
> filesystems handle the case correctly.
> 
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Fine as it is; I've also sent a cleanup patch which you can fold in,
or merge separately, as you wish.

Reviewed-by: Eric Sandeen <sandeen@redhat.com>

> ---
>  tests/generic/030     | 148 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  tests/generic/030.out |  53 ++++++++++++++++++
>  tests/generic/group   |   1 +
>  3 files changed, 202 insertions(+)
>  create mode 100644 tests/generic/030
>  create mode 100644 tests/generic/030.out
> 
> diff --git a/tests/generic/030 b/tests/generic/030
> new file mode 100644
> index 0000000..9947b96
> --- /dev/null
> +++ b/tests/generic/030
> @@ -0,0 +1,148 @@
> +#! /bin/bash
> +# FS QA Test No. generic/030
> +#
> +# Test mapped writes against remap+truncate down/up to ensure we get the data
> +# correctly written. This can expose data corruption bugs on filesystems where
> +# the block size is smaller than the page size.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2014 Red Hat, Inc.  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 $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# real QA test starts here
> +
> +# Modify as appropriate.
> +_supported_fs generic
> +_supported_os IRIX Linux
> +_require_scratch
> +_require_xfs_io_command "mremap"
> +
> +testfile=$SCRATCH_MNT/testfile
> +
> +_scratch_mkfs > /dev/null 2>&1
> +_scratch_mount
> +
> +# first case is just truncate down/truncate up to check that the mapped
> +# write after the truncate up is correctly handled.
> +$XFS_IO_PROG -t -f \
> +-c "truncate 5017k"             `# truncate     |       |` \
> +-c "pwrite -S 0x58 0 5017k"     `# write        |X...XXX|` \
> +-c "mmap -rw 0 5017k"           `# mmap         |       |` \
> +-c "truncate 5020k"             `# truncate up  |                        |` \
> +-c "mremap -m 5020k"            `# mremap up    |                        |` \
> +-c "mwrite -S 0x57 5017k 3k"    `# mwrite       |        WWWWWWWWWWWWWWWW|` \
> +-c "mremap 5017k "              `# mremap dn    |       |` \
> +-c "truncate 5017k"             `# mremap dn    |       |` \
> +-c "truncate 5020k"             `# truncate up  |                        |` \
> +-c "mremap -m 5020k"            `# mremap up    |                        |` \
> +-c "mwrite -S 0x59 5017k 3k"    `# mwrite       |        YYYYYYYYYYYYYYYY|` \
> +-c "close"      \
> +$testfile | _filter_xfs_io
> +
> +echo "==== Pre-Remount ==="
> +hexdump -C $testfile
> +_scratch_remount
> +echo "==== Post-Remount =="
> +hexdump -C $testfile
> +
> +rm -f $testfile
> +sync
> +
> +# second case is to do a mwrite between the truncate to a block on the
> +# same page we are truncating within the EOF. This checks that a mapped
> +# write between truncate down and truncate up a further mapped
> +# write to the same page into the new space doesn't result in data being lost.
> +$XFS_IO_PROG -t -f \
> +-c "truncate 5017k"             `# truncate     |       |` \
> +-c "pwrite -S 0x58 0 5017k"     `# write        |X...XXX|` \
> +-c "mmap -rw 0 5017k"           `# mmap         |       |` \
> +-c "truncate 5020k"             `# truncate up  |                        |` \
> +-c "mremap -m 5020k"            `# mremap up    |                        |` \
> +-c "mwrite -S 0x57 5017k 3k"    `# mwrite       |        WWWWWWWWWWWWWWWW|` \
> +-c "mremap 5017k "              `# mremap dn    |       |` \
> +-c "truncate 5017k"             `# mremap dn    |       |` \
> +-c "mwrite -S 0x5a 5016k 1k"    `# mwrite       |    ZZZ                 |` \
> +-c "truncate 5020k"             `# truncate up  |                        |` \
> +-c "mremap -m 5020k"            `# mremap up    |                        |` \
> +-c "mwrite -S 0x59 5017k 3k"    `# mwrite       |        YYYYYYYYYYYYYYYY|` \
> +-c "close"      \
> +$testfile | _filter_xfs_io
> +
> +echo "==== Pre-Remount ==="
> +hexdump -C $testfile
> +_scratch_remount
> +echo "==== Post-Remount =="
> +hexdump -C $testfile
> +
> +# third case is the same as the first, but this time on unaligned byte
> +# boundaries rather than block boundaries. This mimics the exact mmap write
> +# patterns of the application that exposed the bug in the first place, and
> +# so is somewhat more complex and has repeated operations in it. 
> +$XFS_IO_PROG -t -f \
> +-c "truncate 5136912" \
> +-c "pwrite -S 0x58 0 5136912" \
> +-c "mmap -rw 0 5136912" \
> +-c "mremap 5136912" \
> +-c "truncate 5136912" \
> +-c "truncate 5139720" \
> +-c "mremap -m 5139720" \
> +-c "mwrite -S 0 5136912 2808" \
> +-c "mwrite -S 0 5136912 2808" \
> +-c "mwrite -S 0 5136912 2808" \
> +-c "mremap 5136912 " \
> +-c "truncate 5136912" \
> +-c "truncate 5139720" \
> +-c "mremap -m 5139720" \
> +-c "mwrite -S 0 5136912 2808" \
> +-c "mwrite -S 0 5136912 2808" \
> +-c "mwrite -S 0x59 5136912 2808" \
> +-c "truncate 5140480" \
> +-c "mremap 5140480" \
> +-c "msync -s 0 5140480" \
> +-c "mremap 5139720" \
> +-c "munmap" \
> +-c "close" \
> +$testfile | _filter_xfs_io
> +
> +echo "==== Pre-Remount ==="
> +hexdump -C $testfile
> +_scratch_remount
> +echo "==== Post-Remount =="
> +hexdump -C $testfile
> +
> +status=0
> +exit
> +
> diff --git a/tests/generic/030.out b/tests/generic/030.out
> new file mode 100644
> index 0000000..20f6561
> --- /dev/null
> +++ b/tests/generic/030.out
> @@ -0,0 +1,53 @@
> +QA output created by 030
> +wrote 5137408/5137408 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +==== Pre-Remount ===
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6400  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e7000
> +==== Post-Remount ==
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6400  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e7000
> +wrote 5137408/5137408 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +==== Pre-Remount ===
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6000  5a 5a 5a 5a 5a 5a 5a 5a  5a 5a 5a 5a 5a 5a 5a 5a  |ZZZZZZZZZZZZZZZZ|
> +*
> +004e6400  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e7000
> +==== Post-Remount ==
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6000  5a 5a 5a 5a 5a 5a 5a 5a  5a 5a 5a 5a 5a 5a 5a 5a  |ZZZZZZZZZZZZZZZZ|
> +*
> +004e6400  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e7000
> +wrote 5136912/5136912 bytes at offset 0
> +XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> +==== Pre-Remount ===
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6210  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e6d00  59 59 59 59 59 59 59 59  00 00 00 00 00 00 00 00  |YYYYYYYY........|
> +004e6d10  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
> +*
> +004e7000
> +==== Post-Remount ==
> +00000000  58 58 58 58 58 58 58 58  58 58 58 58 58 58 58 58  |XXXXXXXXXXXXXXXX|
> +*
> +004e6210  59 59 59 59 59 59 59 59  59 59 59 59 59 59 59 59  |YYYYYYYYYYYYYYYY|
> +*
> +004e6d00  59 59 59 59 59 59 59 59  00 00 00 00 00 00 00 00  |YYYYYYYY........|
> +004e6d10  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
> +*
> +004e7000
> diff --git a/tests/generic/group b/tests/generic/group
> index 18c94de..ba1c913 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -32,6 +32,7 @@
>  027 auto enospc
>  028 auto quick
>  029 auto quick rw
> +030 auto quick rw
>  053 acl repair auto quick
>  062 attr udf auto quick
>  068 other auto freeze dangerous stress
>