On Mon, May 08, 2017 at 12:50:40PM -0700, Liu Bo wrote:
> On Wed, May 03, 2017 at 06:08:36PM +0800, Eryu Guan wrote:
> > On Fri, Apr 28, 2017 at 11:25:52AM -0600, Liu Bo wrote:
> > > This case tests whether dio read can repair the bad copy if we have
> > > a good copy.
> > >
> > > Commit 2dabb3248453 ("Btrfs: Direct I/O read: Work on sectorsized blocks")
> > > introduced the regression.
> > >
> > > The upstream fix is
> > > Btrfs: fix invalid dereference in btrfs_retry_endio
> > >
> > > Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
> >
> > Sorry for the late review, and many thanks to Filipe's reviews! I agreed
> > with Filipe that the common helpers can be placed in common/btrfs and/or
> > common/rc files.
> >
> > Some thoughts inline.
> >
> > > ---
> > > v2: - Add regression commit and the fix to the description
> > > - Use btrfs inspect-internal dump-tree to get rid of the dependence btrfs-map-logical
> > > - Add comments in several places
> > >
> > > v3: - Add 'mkfs -b 1G' to limit filesystem size to 2G in raid1 profile so that
> > > we get a consistent output.
> > >
> > > tests/btrfs/140 | 167 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> > > tests/btrfs/140.out | 39 ++++++++++++
> > > tests/btrfs/group | 1 +
> > > 3 files changed, 207 insertions(+)
> > > create mode 100755 tests/btrfs/140
> > > create mode 100644 tests/btrfs/140.out
> > >
> > > diff --git a/tests/btrfs/140 b/tests/btrfs/140
> > > new file mode 100755
> > > index 0000000..dcd8807
> > > --- /dev/null
> > > +++ b/tests/btrfs/140
> > > @@ -0,0 +1,167 @@
> > > +#! /bin/bash
> > > +# FS QA Test 140
> > > +#
> > > +# Regression test for btrfs DIO read's repair during read.
> > > +#
> > > +# Commit 2dabb3248453 ("Btrfs: Direct I/O read: Work on sectorsized blocks")
> > > +# introduced the regression.
> > > +# The upstream fix is
> > > +# Btrfs: fix invalid dereference in btrfs_retry_endio
> > > +#
> > > +#-----------------------------------------------------------------------
> > > +# Copyright (c) 2017 Liu Bo. 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
> > > +
> > > +# remove previous $seqres.full before test
> > > +rm -f $seqres.full
> > > +
> > > +# real QA test starts here
> > > +
> > > +# Modify as appropriate.
> > > +_supported_fs btrfs
> > > +_supported_os Linux
> > > +_require_scratch_dev_pool 2
> > > +
> > > +_require_btrfs_command inspect-internal dump-tree
> > > +_require_command "$FILEFRAG_PROG" filefrag
> > > +_require_odirect
> > > +
> > > +# helpe to convert 'file offset' to btrfs logical offset
> > > +FILEFRAG_FILTER='
> > > + if (/blocks? of (\d+) bytes/) {
> > > + $blocksize = $1;
> > > + next
> > > + }
> > > + ($ext, $logical, $physical, $length) =
> > > + (/^\s*(\d+):\s+(\d+)..\s+\d+:\s+(\d+)..\s+\d+:\s+(\d+):/)
> > > + or next;
> > > + ($flags) = /.*:\s*(\S*)$/;
> > > + print $physical * $blocksize, "#",
> > > + $length * $blocksize, "#",
> > > + $logical * $blocksize, "#",
> > > + $flags, " "'
> > ^^^ "\n" so one extent per line?
> >
> > This can be embedded in the filter function, like what _filter_mkfs
> > does.
> >
>
> OK.
>
> > > +
> > > +# this makes filefrag output script readable by using a perl helper.
> > > +# output is one extent per line, with three numbers separated by '#'
> > > +# the numbers are: physical, length, logical (all in bytes)
> > > +# sample output: "1234#10#5678" -> physical 1234, length 10, logical 5678
> > > +_filter_extents()
> >
> > Global functions start with underscore, local functions don't.
> >
>
> OK.
>
> > > +{
> > > + tee -a $seqres.full | $PERL_PROG -ne "$FILEFRAG_FILTER"
> >
> > I don't think this tee belongs here, see below.
> >
> > > +}
> > > +
> > > +_check_file_extents()
> > > +{
> > > + cmd="filefrag -v $1"
> >
> > $FILEFRAG_PROG
> >
> > > + echo "# $cmd" >> $seqres.full
> >
> > Just call filefrag -v again to dump the filefrag output to $seqres.full
> >
>
> Make sense.
>
> > > + out=`$cmd | _filter_extents`
> > > + if [ -z "$out" ]; then
> > > + return 1
> > > + fi
> > > + echo "after filter: $out" >> $seqres.full
> > > + echo $out
> > > + return 0
> > > +}
> >
> > Hmm, seems that all you want from all these filters is the logical byte
> > of the first extent in the file. How about converting
> > _check_file_extents to _filter_filefrag and put it in common/filter?
> > And _get_physical can also be converted to _btrfs_get_physical and
> > placed in common/btrfs
> > e.g.
> >
> > common/filter:
> > # <comments>
> > _filter_filefrag()
> > {
> > perl -ne '
> > <all the perl filter code here>
> > <like what _filter_mkfs does>
> > '
> > }
> >
> > then
> >
> > logical_in_btrfs=`$FILEFRAG -v $SCRATCH_MNT/foobar | _filter_filefrag | cut -d '#' -f 1`
> > physical_on_scratch=`_btrfs_get_physical $logical_in_btrfs`
> >
>
> Sounds good.
_btrfs_get_physical in this testcase assumes that the test data has been written
to a fixed position (the start position of the only data chunk), so it's not for
generic use, I'd leave it for now instead of creating a new helper in
common/btrfs. After we have stable btrfs-map-block output format, we can build
that helper on top of it.
Thanks,
liubo
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