Re: [PATCH 6/9] generic: test I/O error path by fully filling dm snapshot

[Eryu Guan <eguan@redhat.com>]

On Wed, Mar 25, 2015 at 07:08:39PM -0400, Brian Foster wrote:
> On Fri, Mar 20, 2015 at 06:16:55PM +0800, Eryu Guan wrote:
> > xfs used to panic in this test, this xfs commit fix the bug
> > 
> > 8d6c121 xfs: fix buffer use after free on IO error
> > 
> > ext4 and btrfs trigger WARNING on current 4.0-rc3 kernel
> > 
> > Signed-off-by: Eryu Guan <eguan@redhat.com>
> > ---
> >  common/config         |  1 +
> >  tests/generic/081     | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/generic/081.out |  2 ++
> >  tests/generic/group   |  1 +
> >  4 files changed, 83 insertions(+)
> >  create mode 100755 tests/generic/081
> >  create mode 100644 tests/generic/081.out
> > 
> > diff --git a/common/config b/common/config
> > index e5c3579..3732287 100644
> > --- a/common/config
> > +++ b/common/config
> > @@ -190,6 +190,7 @@ export DMSETUP_PROG="`set_prog_path dmsetup`"
> >  export WIPEFS_PROG="`set_prog_path wipefs`"
> >  export DUMP_PROG="`set_prog_path dump`"
> >  export RESTORE_PROG="`set_prog_path restore`"
> > +export LVM_PROG="`set_prog_path lvm`"
> >  
> >  # Generate a comparable xfsprogs version number in the form of
> >  # major * 10000 + minor * 100 + release
> > diff --git a/tests/generic/081 b/tests/generic/081
> > new file mode 100755
> > index 0000000..476bfb9
> > --- /dev/null
> > +++ b/tests/generic/081
> > @@ -0,0 +1,79 @@
> > +#! /bin/bash
> > +# FS QA Test No. 081
> > +#
> > +# Test I/O error path by fully filling an dm snapshot.
> > +#
> > +#-----------------------------------------------------------------------
> > +# 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!
> > +trap "_cleanup; exit \$status" 0 1 2 3 15
> > +
> > +_cleanup()
> > +{
> > +	cd /
> > +	rm -f $tmp.*
> > +	# lvm may have umounted it on I/O error, but in case it does not
> > +	$UMOUNT_PROG $mnt >/dev/null 2>&1
> > +	$LVM_PROG vgremove -f $vgname >>$seqres.full 2>&1
> > +	$LVM_PROG pvremove -f $SCRATCH_DEV >>$seqres.full 2>&1
> > +}
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +# real QA test starts here
> > +_supported_fs generic
> > +_supported_os Linux
> > +_require_test
> > +_require_scratch_nocheck
> > +_require_block_device $SCRATCH_DEV
> > +_require_command $LVM_PROG lvm
> > +
> > +echo "Silence is golden"
> > +rm -f $seqres.full
> > +
> > +vgname=vg_$seq
> > +lvname=base_$seq
> > +snapname=snap_$seq
> > +mnt=$TEST_DIR/mnt_$seq
> > +mkdir -p $mnt
> > +
> > +$LVM_PROG vgcreate -f $vgname $SCRATCH_DEV >>$seqres.full 2>&1
> > +$LVM_PROG lvcreate --yes -L 256M -n $lvname $vgname >>$seqres.full 2>&1
> > +
> 
> Hmm, I take it this introduces a block size size requirement of 256MB.
> If so, perhaps we could use a sparse file and loop, seeing as we're not
> actually using much space. It's not that big of a deal I suppose, even a
> ramdisk probably has that much space. At the very least we should do
> something like the following:
> 
> lvcreate -L 256M ... || _fail "lvcreate failed"
> 
> ... to catch any failures from these commands.

If vgcreate/lvcreate fails to create lv, the following _mkfs_dev fails
too and breaks the output match.

I think I can _require_fs_space <300M> of SCRATCH_DEV (in case lvm takes
some space to store metadata)

> 
> > +_mkfs_dev /dev/mapper/$vgname-$lvname
> > +
> > +# create a 4M snapshot
> > +$LVM_PROG lvcreate -s -L 4M -n $snapname $vgname/$lvname >>$seqres.full 2>&1
> 
> Same thing here... I guess we're assuming dm-snapshot is available too.
> We might want a require test for that...

Yes, will do.

Thanks for the review!

Eryu
> 
> Brian
> 
> > +
> > +_mount /dev/mapper/$vgname-$snapname $mnt
> > +
> > +# write 5M data to the snapshot
> > +$XFS_IO_PROG -fc "pwrite 0 5m" $mnt/testfile >>$seqres.full 2>&1
> > +
> > +# _check_dmesg will check for WARNINGs/BUGs in dmesg
> > +status=0
> > +exit
> > diff --git a/tests/generic/081.out b/tests/generic/081.out
> > new file mode 100644
> > index 0000000..663a886
> > --- /dev/null
> > +++ b/tests/generic/081.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 081
> > +Silence is golden
> > diff --git a/tests/generic/group b/tests/generic/group
> > index cf7408c..f5ebe48 100644
> > --- a/tests/generic/group
> > +++ b/tests/generic/group
> > @@ -83,6 +83,7 @@
> >  078 auto quick metadata
> >  079 acl attr ioctl metadata auto quick
> >  080 auto freeze mount
> > +081 auto quick
> >  083 rw auto enospc stress
> >  088 perms auto quick
> >  089 metadata auto
> > -- 
> > 2.1.0
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe fstests" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html