On Mon, Sep 25, 2017 at 06:18:47PM +0800, Eryu Guan wrote: > From: Zheng Liu <wenqing.lz@xxxxxxxxxx> > > In this commit a new test case is added to test that i_size races > don't occur under dio reads/writes. We add a program in /src dir, > which has a writer to issue some append dio writes. Meanwhile it > has a reader in this test to do some dio reads. As we expect, > reader should read nothing or data with 'a'. But it might read some > data with '0'. > > The bug can be reproduced by this test case [1]. > > 1. http://patchwork.ozlabs.org/patch/311761/ > > This ostensibly tests commit: > 9fe55eea7 Fix race when checking i_size on direct i/o read > > Update by Eric Sandeen: > - update to recent xfstests > - update commit log > > Update by Eryu Guan: > - add aio-dio support to the test and add 'aio' group > - add ability to test different alignments > - move test from src/ to src/aio-dio-regress/ > - add .gitignore entry > - rebase against latest xfstests with various minor fixes & cleanups > - update commit log > > Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx> > Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> > Signed-off-by: Eryu Guan <eguan@xxxxxxxxxx> > --- > This test fails on XFS, the following patch fixed the XFS failure > https://www.spinics.net/lists/linux-xfs/msg10865.html > > btrfs also fails when io alignment is not 4k, perhaps a btrfs bug? > > Eric's original post > http://www.spinics.net/lists/fstests/msg06978.html > > .gitignore | 1 + > .../aio-dio-append-write-read-race.c | 214 +++++++++++++++++++++ > tests/generic/462 | 75 ++++++++ > tests/generic/462.out | 3 + > tests/generic/group | 1 + > 5 files changed, 294 insertions(+) > create mode 100644 src/aio-dio-regress/aio-dio-append-write-read-race.c > create mode 100755 tests/generic/462 > create mode 100644 tests/generic/462.out > ... > diff --git a/src/aio-dio-regress/aio-dio-append-write-read-race.c b/src/aio-dio-regress/aio-dio-append-write-read-race.c > new file mode 100644 > index 000000000000..dce2ab743f11 > --- /dev/null > +++ b/src/aio-dio-regress/aio-dio-append-write-read-race.c > @@ -0,0 +1,214 @@ ... > + > +int main(int argc, char *argv[]) > +{ ... > + for (i = 0; i < max_blocks; i++) { > + wdata.offset = i * blksize; > + if (use_aio) > + ret = pthread_create(&tid, NULL, aio_writer, &wdata); > + else > + ret = pthread_create(&tid, NULL, dio_writer, &wdata); > + if (ret) { > + fprintf(stderr, "create thread failed: %s\n", > + strerror(ret)); > + ret = 1; > + goto err; > + } > + > + memset(rbuf, 'b', blksize); > + do { > + ret = pread(rfd, rbuf, blksize, i * blksize); > + if (ret < 0) > + perror("read file"); > + } while (ret <= 0); Hmm, so IIUC the objective is to kick off a writer thread then issue reads in a loop to try and guarantee that the first valid read returns valid data. By kicking off the writer first, aren't we risking the test could be silently ineffective if the writer thread happens to run early enough to miss the conversion? I'm wondering if it might be more reliable to start the reader in a background thread first and signal a condition once it starts issuing reads. Then wait for the condition here and invoke the appropriate writer func directly. Brian > + > + ret = pthread_join(tid, NULL); > + if (ret) { > + fprintf(stderr, "pthread join failed: %s\n", > + strerror(ret)); > + ret = 1; > + goto err; > + } > + > + for (j = 0; j < blksize; j++) { > + if (rbuf[j] != 'a') { > + fprintf(stderr, "encounter an error: " > + "block %d offset %d, content %x\n", > + i, j, rbuf[j]); > + ret = 1; > + goto err; > + } > + } > + } > + > +err: > + if (rfd) > + close(rfd); > + if (wfd) > + close(wfd); > + if (rbuf) > + free(rbuf); > + if (wbuf) > + free(wbuf); > + > + exit(ret); > +} > diff --git a/tests/generic/462 b/tests/generic/462 > new file mode 100755 > index 000000000000..7abadcb11921 > --- /dev/null > +++ b/tests/generic/462 > @@ -0,0 +1,75 @@ > +#! /bin/bash > +# FS QA Test No. 462 > +# > +# Test i_size is updated properly under dio read/write > +# > +#----------------------------------------------------------------------- > +# Copyright (c) 2013 Alibaba Group. All Rights Reserved. > +# 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=/tmp/$$ > +status=1 # failure is the default! > +trap "_cleanup; exit \$status" 0 1 2 3 15 > + > +_cleanup() > +{ > + cd / > + rm -f $tmp.* $testfile.* > +} > + > +# get standard environment, filters and checks > +. ./common/rc > +. ./common/filter > + > +# real QA test starts here > +_supported_fs generic > +_supported_os Linux > + > +_require_aiodio aio-dio-append-write-read-race > +_require_test_program "feature" > + > +testfile=$TEST_DIR/$seq.$$ > +min_dio_align=`_min_dio_alignment $TEST_DEV` > +page_size=`$here/src/feature -s` > + > +rm -f $seqres.full > + > +echo "non-aio dio test" > +align=$min_dio_align > +while [ $align -le $page_size ]; do > + echo "$AIO_TEST -a $align -d $testfile.$align" >> $seqres.full > + $AIO_TEST -a $align -d $testfile.$align 2>&1 | tee -a $seqres.full > + align=$((align * 2)) > +done > + > +echo "aio-dio test" > +align=$min_dio_align > +while [ $align -le $page_size ]; do > + echo "$AIO_TEST -a $align $testfile.$align" >> $seqres.full > + $AIO_TEST -a $align $testfile.$align 2>&1 | tee -a $seqres.full > + align=$((align * 2)) > +done > + > +# success, all done > +status=0 > +exit > diff --git a/tests/generic/462.out b/tests/generic/462.out > new file mode 100644 > index 000000000000..9a368005af49 > --- /dev/null > +++ b/tests/generic/462.out > @@ -0,0 +1,3 @@ > +QA output created by 462 > +non-aio dio test > +aio-dio test > diff --git a/tests/generic/group b/tests/generic/group > index dfa86edc4a93..c65058976f1e 100644 > --- a/tests/generic/group > +++ b/tests/generic/group > @@ -464,3 +464,4 @@ > 459 auto dangerous > 460 auto quick rw > 461 auto rw > +462 auto rw quick aio > -- > 2.13.5 > > -- > To unsubscribe from this list: send the line "unsubscribe fstests" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe fstests" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
