Re: [PATCH] xfs_repair: test for false positive reserved attr name use

[Eryu Guan <eguan@redhat.com>]

On Wed, May 13, 2015 at 10:22:18PM -0500, Eric Sandeen wrote:
> xfs_repair compares attr names in the root namespace to
> two special/reserved names, "SGI_ACL_FILE" and "SGI_ACL_DEFAULT"
> and if the value in them aren't valid acls, flags this as
> an inconsistency.
> 
> However, due to various bugs, xfs_repair may only compare
> a smaller portion of the on-disk value; hence either
> substrings or superstrings may match, and false-positive
> corruption will be detected.  This test checks for those
> false positives; i.e. the ACL names created in this test
> may cause xfs_repair to "fix" them, but it should not.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> patch for xfs_repair will be sent shortly
> 
> diff --git a/tests/xfs/053 b/tests/xfs/053
> new file mode 100755
> index 0000000..284c014
> --- /dev/null
> +++ b/tests/xfs/053
> @@ -0,0 +1,76 @@
> +#! /bin/bash
> +# FS QA Test 053
> +#
> +# Ensure that xfs_repair can properly spot SGI_ACL_FILE
> +# and SGI_ACL_DEFAULT in the root attr namespace.
> +#
> +# Due to bugs here and there, we sometimes matched on partial
> +# strings with those names, and threw off xfs_repair.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2015 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!

I haven't run the test yet, but I don't see the trap and cleanup
function, is that on purpose?

> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter

. ./common/attr and _require_attrs ?

> +
> +# real QA test starts here
> +
> +_supported_fs xfs
> +_supported_os IRIX Linux
> +_require_scratch
> +
> +rm -f $seqres.full

Seems this file is not used and the rm can be omitted.

> +
> +_scratch_mount

Should _scratch_mkfs first

> +
> +# Create root namespace attr names which are substrings or superstrings
> +# of the reserved ACL names, and make sure xfs_repair copes.
> +
> +# Due to various bugs, either the compared length was shorter
> +# than the reserved name (7 chars), so substrings matched, and/or only
> +# the reserved name length was compared, so superstrings matched.
> +
> +rm -f $SCRATCH_MNT/$seq.*

If it's fresh fs, this seems unnecessary.

> +
> +# actual reserved names:
> +#           SGI_ACL_FILE	SGI_ACL_DEFAULT \
> +for NAME in SGI_ACL \
> +	    SGI_ACL_F		SGI_ACL_D \
> +	    SGI_ACL_FILE_FOO	SGI_ACL_DEFAULT_FOO; do
> +	touch $SCRATCH_MNT/${seq}.${NAME}
> +	attr -R -s $NAME -V "Wow, such $NAME" $SCRATCH_MNT/${seq}.${NAME} \
> +		| _filter_scratch

$ATTR_PROG

Thanks,
Eryu

> +done
> +
> +# Older repair failed because it sees the above names as matching
> +# SGI_ACL_FILE / SGI_ACL_DEFAULT but w/o valid acls on them
> +
> +# The test harness will catch this (false positive) corruption
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/xfs/053.out b/tests/xfs/053.out
> new file mode 100644
> index 0000000..d876555
> --- /dev/null
> +++ b/tests/xfs/053.out
> @@ -0,0 +1,11 @@
> +QA output created by 053
> +Attribute "SGI_ACL" set to a 17 byte value for SCRATCH_MNT/053.SGI_ACL:
> +Wow, such SGI_ACL
> +Attribute "SGI_ACL_F" set to a 19 byte value for SCRATCH_MNT/053.SGI_ACL_F:
> +Wow, such SGI_ACL_F
> +Attribute "SGI_ACL_D" set to a 19 byte value for SCRATCH_MNT/053.SGI_ACL_D:
> +Wow, such SGI_ACL_D
> +Attribute "SGI_ACL_FILE_FOO" set to a 26 byte value for SCRATCH_MNT/053.SGI_ACL_FILE_FOO:
> +Wow, such SGI_ACL_FILE_FOO
> +Attribute "SGI_ACL_DEFAULT_FOO" set to a 29 byte value for SCRATCH_MNT/053.SGI_ACL_DEFAULT_FOO:
> +Wow, such SGI_ACL_DEFAULT_FOO
> diff --git a/tests/xfs/group b/tests/xfs/group
> index 58144d2..26dd881 100644
> --- a/tests/xfs/group
> +++ b/tests/xfs/group
> @@ -50,6 +50,7 @@
>  050 quota auto quick
>  051 auto log metadata
>  052 quota db auto quick
> +053 acl auto
>  054 quota auto quick
>  055 dump ioctl remote tape
>  056 dump ioctl auto quick
> 
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