On Fri, Jun 23, 2017 at 10:40 AM, Eryu Guan <eguan@xxxxxxxxxx> wrote:
> On Fri, Jun 23, 2017 at 02:11:16AM +0200, Andreas Gruenbacher wrote:
>> Both ext4 and xfs have a bug in the page cache scanning code for
>> SEEK_HOLE / SEEK_DATA in unwritten extents: the start offset isn't taken
>> into account when scanning a page, so seeking can fail on filesystems
>> with a block size less than half of the page size. For example, the
>> following command fails on a filesystem with a block size of 1k:
>>
>> xfs_io -f -c "falloc 0 4k" \
>> -c "pwrite 1k 1k" \
>> -c "pwrite 3k 1k" \
>> -c "seek -a -r 0" foo
>>
>> Like with generic/436, the actual tests are added to seek_sanity_test.
>>
>> Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
>> ---
>> src/seek_sanity_test.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++
>> tests/generic/441 | 64 +++++++++++++++++++++++++++++++++++++++++++
>> tests/generic/441.out | 2 ++
>> tests/generic/group | 1 +
>> 4 files changed, 140 insertions(+)
>> create mode 100755 tests/generic/441
>> create mode 100644 tests/generic/441.out
>>
>> diff --git a/src/seek_sanity_test.c b/src/seek_sanity_test.c
>> index c9e9366..bf323f2 100644
>> --- a/src/seek_sanity_test.c
>> +++ b/src/seek_sanity_test.c
>> @@ -277,6 +277,78 @@ out:
>> return ret;
>> }
>>
>> +static int test17(int fd, int testnum)
>> +{
>> + char *buf = NULL;
>> + int pagesz = sysconf(_SC_PAGE_SIZE);
>> + int bufsz, filsz;
>> + int ret = 0;
>> +
>> + if (!unwritten_extents) {
>> + fprintf(stdout, "Test skipped\n");
>> + goto out;
>> + }
>
> Currently 'unwritten_extents' is not defined. I know it's from patch
> "src/seek_sanity_test: Fix for filesystems without unwritten extent
> support"[1] back in May, but I haven't merged it, because it used
> SEEK_DATA to check if fs supports unwritten extent and I think it's hard
> to tell if it's a SEEK_DATA bug or if fs really doesn't support
> unwritten extent. We're testing SEEK_DATA/SEEK_HOLE interface in this
> test, probably we shouldn't rely on it to setup the test.
seek_sanity_test also checks for SEEK_HOLE/SEEK_DATA support, so it's
not a new concept to check for something in the most basic form and
then test that feature more thoroughly.
> But again, if there're better ways to do the detection, please kindly
> advise.
>
> Otherwise this test looks fine to me.
Ok, can you merge without the unwritten_extents?
Thanks,
Andreas
> Thanks,
> Eryu
>
> [1] https://www.spinics.net/lists/fstests/msg06223.html
>
>> +
>> + if (pagesz < 4 * alloc_size) {
>> + fprintf(stdout, "Test skipped as page size (%d) is less than "
>> + "four times allocation size (%d).\n",
>> + pagesz, (int)alloc_size);
>> + goto out;
>> + }
>> + bufsz = alloc_size;
>> + filsz = 3 * bufsz;
>> +
>> + buf = do_malloc(bufsz);
>> + if (!buf) {
>> + ret = -1;
>> + goto out;
>> + }
>> + memset(buf, 'a', bufsz);
>> +
>> + ret = do_fallocate(fd, 0, filsz, 0);
>> + if (ret < 0) {
>> + /* Report success if fs doesn't support fallocate */
>> + if (errno == EOPNOTSUPP) {
>> + fprintf(stdout, "Test skipped as fs doesn't support fallocate.\n");
>> + ret = 0;
>> + }
>> + goto out;
>> + }
>> +
>> + ret = do_pwrite(fd, buf, bufsz, 0);
>> + if (ret)
>> + goto out;
>> +
>> + ret = do_pwrite(fd, buf, bufsz, 2 * bufsz);
>> + if (ret)
>> + goto out;
>> +
>> + ret += do_lseek(testnum, 1, fd, filsz, SEEK_DATA, 0, 0);
>> + ret += do_lseek(testnum, 2, fd, filsz, SEEK_HOLE, 0, bufsz);
>> + ret += do_lseek(testnum, 3, fd, filsz, SEEK_DATA, 1, 1);
>> + ret += do_lseek(testnum, 4, fd, filsz, SEEK_HOLE, 1, bufsz);
>> + ret += do_lseek(testnum, 5, fd, filsz, SEEK_DATA, bufsz, 2 * bufsz);
>> + ret += do_lseek(testnum, 6, fd, filsz, SEEK_HOLE, bufsz, bufsz);
>> + ret += do_lseek(testnum, 7, fd, filsz, SEEK_DATA, bufsz + 1, 2 * bufsz);
>> + ret += do_lseek(testnum, 8, fd, filsz, SEEK_HOLE, bufsz + 1, bufsz + 1);
>> + ret += do_lseek(testnum, 9, fd, filsz, SEEK_DATA, 2 * bufsz, 2 * bufsz);
>> + ret += do_lseek(testnum, 10, fd, filsz, SEEK_HOLE, 2 * bufsz, 3 * bufsz);
>> + ret += do_lseek(testnum, 11, fd, filsz, SEEK_DATA, 2 * bufsz + 1, 2 * bufsz + 1);
>> + ret += do_lseek(testnum, 12, fd, filsz, SEEK_HOLE, 2 * bufsz + 1, 3 * bufsz);
>> +
>> + filsz += bufsz;
>> + ret += do_fallocate(fd, 0, filsz, 0);
>> +
>> + ret += do_lseek(testnum, 13, fd, filsz, SEEK_DATA, 3 * bufsz, -1);
>> + ret += do_lseek(testnum, 14, fd, filsz, SEEK_HOLE, 3 * bufsz, 3 * bufsz);
>> + ret += do_lseek(testnum, 15, fd, filsz, SEEK_DATA, 3 * bufsz + 1, -1);
>> + ret += do_lseek(testnum, 16, fd, filsz, SEEK_HOLE, 3 * bufsz + 1, 3 * bufsz + 1);
>> +
>> +out:
>> + do_free(buf);
>> + return ret;
>> +}
>> +
>> /*
>> * test file with unwritten extents, having non-contiguous dirty pages in
>> * the unwritten extent.
>> @@ -912,6 +984,7 @@ struct testrec seek_tests[] = {
>> { 14, test14, "Test file with unwritten extents, small hole after pagevec dirty pages" },
>> { 15, test15, "Test file with unwritten extents, page after unwritten extent" },
>> { 16, test16, "Test file with unwritten extents, non-contiguous dirty pages" },
>> + { 17, test17, "Test file with unwritten extents, data-hole-data inside page" },
>> };
>>
>> static int run_test(struct testrec *tr)
>> diff --git a/tests/generic/441 b/tests/generic/441
>> new file mode 100755
>> index 0000000..295ccf4
>> --- /dev/null
>> +++ b/tests/generic/441
>> @@ -0,0 +1,64 @@
>> +#! /bin/bash
>> +# FS QA Test 441
>> +#
>> +# Another SEEK_DATA/SEEK_HOLE sanity test.
>> +#
>> +#-----------------------------------------------------------------------
>> +# Copyright (c) 2017 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=$$
>> +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=$TEST_DIR/seek_sanity_testfile
>> +
>> +_require_test_program "seek_sanity_test"
>> +
>> +# Disable extent zeroing for ext4 as that change where holes are created
>> +if [ "$FSTYP" = "ext4" ]; then
>> + DEV=`_short_dev $TEST_DEV`
>> + echo 0 >/sys/fs/ext4/$DEV/extent_max_zeroout_kb
>> +fi
>> +
>> +_cleanup()
>> +{
>> + rm -f $tmp.* $BASE_TEST_FILE.*
>> +}
>> +
>> +$here/src/seek_sanity_test -s 17 -e 17 $BASE_TEST_FILE > $seqres.full 2>&1 ||
>> + _fail "seek sanity check failed!"
>> +
>> +# success, all done
>> +echo "Silence is golden"
>> +status=0
>> +exit
>> diff --git a/tests/generic/441.out b/tests/generic/441.out
>> new file mode 100644
>> index 0000000..842f9c4
>> --- /dev/null
>> +++ b/tests/generic/441.out
>> @@ -0,0 +1,2 @@
>> +QA output created by 441
>> +Silence is golden
>> diff --git a/tests/generic/group b/tests/generic/group
>> index ab1e9d3..5046c97 100644
>> --- a/tests/generic/group
>> +++ b/tests/generic/group
>> @@ -443,3 +443,4 @@
>> 438 auto
>> 439 auto quick punch
>> 440 auto quick encrypt
>> +441 auto quick rw
>> --
>> 2.7.5
>>
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