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.
Signed-off-by: Dmitry Monakhov <[email protected]>
---
src/aio-dio-regress/aio-dio-fcntl-race.c | 144 ++++++++++++++++++++++++++++++
tests/generic/326 | 51 +++++++++++
tests/generic/326.out | 2 +
tests/generic/group | 1 +
4 files changed, 198 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..db012d8
--- /dev/null
+++ b/src/aio-dio-regress/aio-dio-fcntl-race.c
@@ -0,0 +1,144 @@
+/*
+ * 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
+
+
+int do_aio_write(int fd, void *buf)
+{
+ struct io_context *ctx = NULL;
+ struct io_event ev;
+ struct iocb iocb, *iocbs[] = { &iocb };
+ int err;
+
+ err = io_setup(1, &ctx);
+ if (err) {
+ if (err == -EAGAIN)
+ return 0;
+ fprintf(stderr, "error %s during %s\n",
+ strerror(-err), "io_setup" );
+ return 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");
+ return 1;
+ }
+ err = io_getevents(ctx, 1, 1, &ev, NULL);
+ if (err != 1) {
+ fprintf(stderr, "error %s during %s\n",
+ strerror(-err),
+ "io_getevents");
+ return 1;
+ }
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int flags, fd;
+ int pid1, pid2 = 0;
+ int ret1, ret = 0;
+
+ struct timeval start, now, delta = { 0, 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;
+
+ gettimeofday(&start, NULL);
+ if (pid1 == 0) {
+ /* 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");
+
+ while(1) {
+ do_aio_write(fd, buf);
+
+ gettimeofday(&now, NULL);
+ timersub(&now, &start, &delta);
+ if (delta.tv_sec >= LOOP_SECONDS)
+ break;
+ }
+ }
+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
Hi Dmitry Monakhov,
Without applying Ext4 path, i could easily trigger BUG_ON()
using this test.
But after applying the patch, test is eating out memory quickly
and failed eventually.
[root@vm01 xfstests-dev]# ./check tests/generic/326
FSTYP -- ext4
PLATFORM -- Linux/x86_64 vm01 3.17.0-rc5+
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- -o acl,user_xattr /dev/sdc /mnt/scratch
generic/326 - output mismatch (see /root/xfstests-dev/results//generic/326.out.bad)
--- tests/generic/326.out 2014-10-09 18:16:44.554059794 -0400
+++ /root/xfstests-dev/results//generic/326.out.bad 2014-10-09 18:46:32.199023371 -0400
@@ -1,2 +1,286458 @@
QA output created by 326
+error Cannot allocate memory during io_setup
+error Cannot allocate memory during io_setup
+error Cannot allocate memory during io_setup
+error Cannot allocate memory during io_setup
+error Cannot allocate memory during io_setup
+error Cannot allocate memory during io_setup
...
(Run 'diff -u tests/generic/326.out /root/xfstests-dev/results//generic/326.out.bad' to see the entire diff)
Ran: generic/326
Failures: generic/326
Failed 1 of 1 tests
> 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.
>
> Signed-off-by: Dmitry Monakhov <[email protected]>
> ---
> src/aio-dio-regress/aio-dio-fcntl-race.c | 144 ++++++++++++++++++++++++++++++
> tests/generic/326 | 51 +++++++++++
> tests/generic/326.out | 2 +
> tests/generic/group | 1 +
> 4 files changed, 198 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..db012d8
> --- /dev/null
> +++ b/src/aio-dio-regress/aio-dio-fcntl-race.c
> @@ -0,0 +1,144 @@
> +/*
> + * 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
> +
> +
> +int do_aio_write(int fd, void *buf)
> +{
> + struct io_context *ctx = NULL;
> + struct io_event ev;
> + struct iocb iocb, *iocbs[] = { &iocb };
> + int err;
> +
> + err = io_setup(1, &ctx);
> + if (err) {
> + if (err == -EAGAIN)
> + return 0;
> + fprintf(stderr, "error %s during %s\n",
> + strerror(-err), "io_setup" );
> + return 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");
> + return 1;
> + }
> + err = io_getevents(ctx, 1, 1, &ev, NULL);
> + if (err != 1) {
> + fprintf(stderr, "error %s during %s\n",
> + strerror(-err),
> + "io_getevents");
> + return 1;
> + }
> + return 0;
> +}
> +
> +int main(int argc, char **argv)
> +{
> + int flags, fd;
> + int pid1, pid2 = 0;
> + int ret1, ret = 0;
> +
> + struct timeval start, now, delta = { 0, 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;
> +
> + gettimeofday(&start, NULL);
> + if (pid1 == 0) {
> + /* 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");
> +
> + while(1) {
> + do_aio_write(fd, buf);
> +
> + gettimeofday(&now, NULL);
> + timersub(&now, &start, &delta);
> + if (delta.tv_sec >= LOOP_SECONDS)
> + break;
> + }
> + }
> +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
>
> --
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Best Regards,
Wang Shilong