Re: [PATCH] ext4/309: Add SEEK_DATA tests for offsets in the middle of holes

[Eryu Guan <guaneryu@gmail.com>]

On Thu, May 10, 2018 at 06:51:32PM +0300, Amir Goldstein wrote:
> On Thu, May 10, 2018 at 6:41 PM, Jan Kara <jack@suse.cz> wrote:
> > ext4 had a bug for files with indirect extents where it wrongly reported
> > a size of a hole in some cases and thus SEEK_DATA implementation could
> > skip some data in a file. Test for that. The problem is fixed by patch
> > "ext4: Fix hole length detection in ext4_ind_map_blocks()".
> >
> > Signed-off-by: Jan Kara <jack@suse.cz>
> > ---
> >  src/seek_sanity_test.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
> >  tests/ext4/309         | 56 +++++++++++++++++++++++++++++++++++++++
> >  tests/ext4/309.out     |  1 +
> >  tests/ext4/group       |  1 +
> >  4 files changed, 129 insertions(+)
> >  create mode 100755 tests/ext4/309
> >  create mode 100644 tests/ext4/309.out
> >
> > Note that I'm adding new tests to a common test program src/seek_sanity_test
> > but I only use them from ext4 specific test as the offsets are pretty ext4
> > specific and so I don't see any use in making this run for all other
> > filesystems. If people think it should be done differently, please speak up.
> 
> I think its a very quick test and it deserves to be in generic.
> Even thought the numbers are computed for ext4, the test is generic
> enough to run on all fs.

Agreed.

> 
> >
> > diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
> > index e82cb1f78671..9245464400e8 100644
> > --- a/src/seek_sanity_test.c
> > +++ b/src/seek_sanity_test.c
> > @@ -274,6 +274,75 @@ out:
> >         return ret;
> >  }
> >
> > +/*
> > + * Make sure hole size is properly reported when starting in the middle of a
> > + * hole in ext? doubly indirect tree
> > + */
> > +static int test20(int fd, int testnum)
> > +{
> > +       int ret = -1;
> > +       char *buf = NULL;
> > +       loff_t bufsz, filsz;
> > +
> > +       bufsz = alloc_size;
> > +       buf = do_malloc(bufsz);
> > +       if (!buf)
> > +               goto out;
> > +       memset(buf, 'a', bufsz);
> > +
> > +       /* Magic size in the middle of ext[23] triple indirect tree */
> > +       filsz = (12 + bufsz / 4 + 8 * bufsz / 4 * bufsz / 4 + 2 * bufsz / 4 + 5) * bufsz;
> > +       ret = do_pwrite(fd, buf, bufsz, filsz - bufsz);
> > +       if (ret)
> > +               goto out;
> > +
> > +       /* Offset inside ext[23] indirect block */
> > +       ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, 14 * bufsz, filsz - bufsz);
> > +       /* Offset inside ext[23] doubly indirect block */
> > +       ret += do_lseek(testnum, 2, fd, filsz, SEEK_DATA, (12 + 2 * bufsz / 4) * bufsz, filsz - bufsz);
> > +       /* Offsets inside ext[23] triply indirect block */
> > +       ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
> > +               (12 + bufsz / 4 + bufsz / 4 * bufsz / 4 + 3 * bufsz / 4 + 5) * bufsz, filsz - bufsz);
> > +       ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
> > +               (12 + bufsz / 4 + 7 * bufsz / 4 * bufsz / 4 + 5 * bufsz / 4) * bufsz, filsz - bufsz);
> > +       ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA,
> > +               (12 + bufsz / 4 + 8 * bufsz / 4 * bufsz / 4 + bufsz / 4 + 11) * bufsz, filsz - bufsz);
> > +out:
> > +       if (buf)
> > +               free(buf);
> > +       return ret;
> > +}
> > +/*
> > + * Make sure hole size is properly reported when starting in the middle of a
> > + * hole in ext? indirect tree
> > + */
> > +static int test19(int fd, int testnum)
> > +{
> > +       int ret = -1;
> > +       char *buf = NULL;
> > +       int bufsz, filsz;
> > +
> > +       bufsz = alloc_size;
> > +       buf = do_malloc(bufsz);
> > +       if (!buf)
> > +               goto out;
> > +       memset(buf, 'a', bufsz);
> > +
> > +       /* Magic size just beyond ext[23] indirect tree size */
> > +       filsz = (12 + bufsz / 4 + 1) * bufsz;
> > +       ret = do_pwrite(fd, buf, bufsz, filsz - bufsz);
> > +       if (ret)
> > +               goto out;
> > +
> > +       ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, bufsz, filsz - bufsz);
> > +       ret += do_lseek(testnum, 2, fd, filsz, SEEK_DATA, 12*bufsz, filsz - bufsz);
> > +       ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA, (12 + bufsz / 4 - 8)*bufsz, filsz - bufsz);
> > +out:
> > +       if (buf)
> > +               free(buf);
> > +       return ret;
> > +}
> > +
> >  /* Make sure we get ENXIO if we pass in a negative offset. */
> >  static int test18(int fd, int testnum)
> >  {
> > @@ -982,6 +1051,8 @@ struct testrec seek_tests[] = {
> >         { 16, test16, "Test file with unwritten extents, non-contiguous dirty pages" },
> >         { 17, test17, "Test file with unwritten extents, data-hole-data inside page" },
> >         { 18, test18, "Test file with negative SEEK_{HOLE,DATA} offsets" },
> > +       { 19, test19, "Test file SEEK_DATA from middle of a large hole" },
> > +       { 20, test20, "Test file SEEK_DATA from middle of a huge hole" },
> >  };
> >
> >  static int run_test(struct testrec *tr)
> > diff --git a/tests/ext4/309 b/tests/ext4/309
> > new file mode 100755
> > index 000000000000..ef56503db0f9
> > --- /dev/null
> > +++ b/tests/ext4/309
> > @@ -0,0 +1,56 @@
> > +#! /bin/bash
> > +# FS QA Test No. 309
> > +#
> > +# SEEK_DATA sanity tests.
> 
> Please mention this is a regression test for ext4 bug fix
> with commit id.

And it'd be good to have some more descriptive information on what the
test actually exercises here.

Thanks,
Eryu

> 
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2018 SUSE.  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 $seq"
> > +
> > +here=`pwd`
> > +status=1       # failure is the default!
> > +trap "_cleanup; exit \$status" 0 1 2 3 15
> > +
> > +# get standard environment, filters and checks
> > +. ./common/rc
> > +. ./common/filter
> > +
> > +_supported_fs generic
> > +_supported_os Linux
> > +
> > +_require_test
> > +_require_seek_data_hole
> > +
> > +BASE_TEST_FILE=$TEST_DIR/seek_sanity_testfile
> > +
> > +_require_test_program "seek_sanity_test"
> > +
> > +_cleanup()
> > +{
> > +       eval "rm -f $BASE_TEST_FILE.*"
> > +}
> > +
> > +$here/src/seek_sanity_test -s 19 -e 20 $BASE_TEST_FILE > $seqres.full 2>&1 ||
> > +       _fail "seek sanity check failed!"
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/ext4/309.out b/tests/ext4/309.out
> > new file mode 100644
> > index 000000000000..2b6375844df5
> > --- /dev/null
> > +++ b/tests/ext4/309.out
> > @@ -0,0 +1 @@
> > +QA output created by 309
> > diff --git a/tests/ext4/group b/tests/ext4/group
> > index 5bd15f82b3be..74f8273f5667 100644
> > --- a/tests/ext4/group
> > +++ b/tests/ext4/group
> > @@ -44,3 +44,4 @@
> >  306 auto rw resize quick
> >  307 auto ioctl rw defrag
> >  308 auto ioctl rw prealloc quick defrag
> > +309 auto quick
> 
> Maybe group 'rw' like the rest of the seek_sanity_test tests.
> 
> Thanks,
> Amir.
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