2014-10-09 22:57 GMT+08:00 Dmitry Monakhov > Original report: https://lkml.org/lkml/2014/10/8/545 > perform AIO-DIO and fcntl(F_SETFL) concurently > Unaligned AIO likely result in synchronization which makes racewindow wider. > > changes from v1->v2 > - Properly reuse aio context > > Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx> > — this test could not reproduce problem every time, but i could always produce it within 10 times, after applying Ext4 kernel patch, tests passed after looping 100 times! Tested-by: Wang Shilong <wangshilong1991@xxxxxxxxx > src/aio-dio-regress/aio-dio-fcntl-race.c | 148 ++++++++++++++++++++++++++++++ > tests/generic/326 | 51 ++++++++++ > tests/generic/326.out | 2 + > tests/generic/group | 1 + > 4 files changed, 202 insertions(+), 0 deletions(-) > create mode 100644 src/aio-dio-regress/aio-dio-fcntl-race.c > create mode 100755 tests/generic/326 > create mode 100644 tests/generic/326.out > > diff --git a/src/aio-dio-regress/aio-dio-fcntl-race.c b/src/aio-dio-regress/aio-dio-fcntl-race.c > new file mode 100644 > index 0000000..835dbdf > --- /dev/null > +++ b/src/aio-dio-regress/aio-dio-fcntl-race.c > @@ -0,0 +1,148 @@ > +/* > + * Perform aio writes to file and toggle O_DIRECT flag concurrently > + * this may trigger race between file->f_flags read and modification > + * unuligned aio allow to makes race window wider. > + * Regression test for https://lkml.org/lkml/2014/10/8/545 > + * > + * Copyright (C) 2010 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; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will 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 to the Free Software > + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. > + */ > +#include <sys/stat.h> > +#include <sys/types.h> > +#include <errno.h> > +#include <fcntl.h> > +#include <unistd.h> > +#include <libaio.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <time.h> > +#include <sys/time.h> > +#include <sys/types.h> > +#include <sys/wait.h> > + > +#define BUF_SIZE 512 > +#define LOOP_SECONDS 10 > + > + > +static int do_aio_loop(int fd, void *buf) > +{ > + int err, ret; > + struct io_context *ctx = NULL; > + struct io_event ev; > + struct iocb iocb, *iocbs[] = { &iocb }; > + struct timeval start, now, delta = { 0, 0 }; > + > + ret = 0; > + err = io_setup(1, &ctx); > + if (err) { > + fprintf(stderr, "error %s during %s\n", > + strerror(-err), "io_setup" ); > + return 1; > + } > + while (1) { > + io_prep_pwrite(&iocb, fd, buf, BUF_SIZE, BUF_SIZE); > + err = io_submit(ctx, 1, iocbs); > + if (err != 1) { > + fprintf(stderr, "error %s during %s\n", > + strerror(-err), > + "io_submit"); > + ret = 1; > + break; > + } > + err = io_getevents(ctx, 1, 1, &ev, NULL); > + if (err != 1) { > + fprintf(stderr, "error %s during %s\n", > + strerror(-err), > + "io_getevents"); > + ret = 1; > + break; > + } > + gettimeofday(&now, NULL); > + timersub(&now, &start, &delta); > + if (delta.tv_sec >= LOOP_SECONDS) > + break; > + } > + io_destroy(ctx); > + return ret; > +} > + > +int main(int argc, char **argv) > +{ > + int flags, fd; > + int pid1, pid2 = 0; > + int ret1, ret = 0; > + > + if (argc != 2){ > + printf("Usage %s fname\n", argv[0]); > + return 1; > + } > + fd = open(argv[1], O_CREAT | O_TRUNC | O_RDWR, 0600); > + if (fd < 0) > + return 1; > + > + pid1 = fork(); > + if (pid1 < 0) > + return 1; > + > + if (pid1 == 0) { > + struct timeval start, now, delta = { 0, 0 }; > + > + gettimeofday(&start, NULL); > + > + /* child: toggle O_DIRECT*/ > + flags = fcntl(fd, F_GETFL); > + while (1) { > + ret = fcntl(fd, F_SETFL, flags | O_DIRECT); > + if (ret) > + return ret; > + ret = fcntl(fd, F_SETFL, flags); > + if (ret) > + return ret; > + > + gettimeofday(&now, NULL); > + timersub(&now, &start, &delta); > + if (delta.tv_sec >= LOOP_SECONDS) > + break; > + } > + } else { > + /* parent: AIO */ > + void *buf; > + posix_memalign(&buf, BUF_SIZE, BUF_SIZE); > + /* Two tasks which performs unaligned aio will be serialized > + which maks race window wider */ > + pid2 = fork(); > + if (pid2 < 0) > + goto out; > + else if (pid2 > 0) > + printf("All tasks are spawned\n"); > + > + ret = do_aio_loop(fd, buf); > + } > +out: > + /* Parent wait for all others */ > + if (pid2 > 0){ > + waitpid(pid1, &ret1, 0); > + if (!ret) > + ret = ret1; > + waitpid(pid2, &ret1, 0); > + } else { > + waitpid(pid1, &ret1, 0); > + } > + if (!ret) > + ret = ret1; > + > + return ret; > +} > diff --git a/tests/generic/326 b/tests/generic/326 > new file mode 100755 > index 0000000..8975a91 > --- /dev/null > +++ b/tests/generic/326 > @@ -0,0 +1,51 @@ > +#! /bin/bash > +# FS QA Test No. 326 > +# > +# Run aio-dio-fcntl-race - test aio write race with O_DIRECT toggle > +# > +#----------------------------------------------------------------------- > +# Copyright (c) 2009 Dmitry Monakhov. 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 > + > +# real QA test starts here > + > +_supported_fs generic > +_supported_os Linux > +_require_test > + > +_run_aiodio aio-dio-fcntl-race > + > +exit $status > diff --git a/tests/generic/326.out b/tests/generic/326.out > new file mode 100644 > index 0000000..a0c44b9 > --- /dev/null > +++ b/tests/generic/326.out > @@ -0,0 +1,2 @@ > +QA output created by 326 > +All tasks are spawned > diff --git a/tests/generic/group b/tests/generic/group > index 799bfd8..4aea4c6 100644 > --- a/tests/generic/group > +++ b/tests/generic/group > @@ -151,3 +151,4 @@ > 323 auto aio stress > 324 auto fsr quick > 325 auto quick data log > +326 auto quick aio rw stress > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html Best Regards, Wang Shilong -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
