On 22/11/17 11:02AM, Theodore Ts'o wrote:
> On Mon, Nov 07, 2022 at 05:50:49PM +0530, Ritesh Harjani (IBM) wrote:
> > f_crashdisk test failed with UNIX_IO_FORCE_BOUNCE=yes due to unbalanced
> > mutex unlock in below path.
> >
> > This patch fixes it.
> >
> > Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
>
> This has been fixed in upstream (for a while, actually);
Hello Ted,
I think you are speaking about this patch here [1], which prevents the race
of using the fd by multiple threads at a time, by using BOUNCE_MTX lock.
The current patch on the other hand fixes the unbalanced mutex_unlock(), which
can be reproduced with f_crashdisk test with UNIX_IO_FORCE_BOUNCE=yes.
(when tested with --enable-threadsan)
Below is the threadsan warning that I see.
WARNING: ThreadSanitizer: unlock of an unlocked mutex (or by a wrong thread) (pid=135059)
#0 pthread_mutex_unlock <null> (libtsan.so.0+0x3b64a)
#1 mutex_unlock ../../../lib/ext2fs/unix_io.c:161 (e2fsck+0x5b392b)
#2 raw_read_blk ../../../lib/ext2fs/unix_io.c:331 (e2fsck+0x5b392b)
#3 unix_read_blk64 ../../../lib/ext2fs/unix_io.c:1001 (e2fsck+0x5b4981)
#4 unix_read_blk ../../../lib/ext2fs/unix_io.c:1053 (e2fsck+0x5b5171)
#5 ext2fs_open2 ../../../lib/ext2fs/openfs.c:228 (e2fsck+0x579e5c)
#6 try_open_fs ../../e2fsck/unix.c:1242 (e2fsck+0x424e63)
#7 main ../../e2fsck/unix.c:1604 (e2fsck+0x41a1d2)
Location is heap block of size 376 at 0x7b4800000000 allocated by main thread:
#0 malloc <null> (libtsan.so.0+0x32919)
#1 ext2fs_get_mem ../../../lib/ext2fs/ext2fs.h:1944 (e2fsck+0x5aec30)
#2 unix_open_channel ../../../lib/ext2fs/unix_io.c:698 (e2fsck+0x5aec30)
#3 unix_open ../../../lib/ext2fs/unix_io.c:910 (e2fsck+0x5afd67)
#4 ext2fs_open2 ../../../lib/ext2fs/openfs.c:175 (e2fsck+0x579918)
#5 try_open_fs ../../e2fsck/unix.c:1242 (e2fsck+0x424e63)
#6 main ../../e2fsck/unix.c:1604 (e2fsck+0x41a1d2)
Mutex M22 (0x7b4800000128) created at:
#0 pthread_mutex_init <null> (libtsan.so.0+0x49603)
#1 unix_open_channel ../../../lib/ext2fs/unix_io.c:827 (e2fsck+0x5af5ef)
#2 unix_open ../../../lib/ext2fs/unix_io.c:910 (e2fsck+0x5afd67)
#3 ext2fs_open2 ../../../lib/ext2fs/openfs.c:175 (e2fsck+0x579918)
#4 try_open_fs ../../e2fsck/unix.c:1242 (e2fsck+0x424e63)
#5 main ../../e2fsck/unix.c:1604 (e2fsck+0x41a1d2)
SUMMARY: ThreadSanitizer: unlock of an unlocked mutex (or by a wrong thread) (/lib64/libtsan.so.0+0x3b64a) in pthread_mutex_unlock
[1]: https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/commit/?id=d557b9659ba97e093f842dcc7e2cfe9a7022c674
> what commit is your patches based upon?
1. This series is rebased on the latest e2fsprogs master branch.
https://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git/log/
Cover letter might provide some more details on how the patch series is broken
into. The github link of the series can be found at
https://github.com/riteshharjani/e2fsprogs/commits/pfsck-RFCv1
Note: I have provided some details in the cover letter about Patch-073 i.e.
("tests: Add multi-thread tests framework"). But putting it once again here...
You can ignore this ^^^ last patch in the github link.
This was added to tests all existing e2fsck test with pfsck mode.
But later I realized that it will require more work then how it is in the current
form. Since I didn't want to hold the patch series any longer and I wanted this
series to go through the initial round of review, before it becomes any
bigger and difficult to review, hence I decided to drop the last patch from
sending it to mailing list.
Please let me know if you have any queries on any patch/series.
-ritesh
