On Mon, Oct 09, 2017 at 12:39:52PM -0400, Brian Foster wrote: > 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. Makes sense, I'll convert it to run reader in a thread and only start writer after reader is ready. Thanks for the review! Eryu > > 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 linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
