KCSAN: data-race in ext4_fc_commit / ext4_fc_commit (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 42eb8fdac2fc Merge tag 'gfs2-v5.16-rc2-fixes' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13a567fab00000
kernel config: https://syzkaller.appspot.com/x/.config?x=a70237460d215073
dashboard link: https://syzkaller.appspot.com/bug?extid=8a25420757b5dd767814
compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.2
CC: [adilger...@dilger.ca linux...@vger.kernel.org linux-...@vger.kernel.org ty...@mit.edu]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8a2542...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in ext4_fc_commit / ext4_fc_commit

write to 0xffff8881031fa820 of 8 bytes by task 10761 on cpu 0:
ext4_fc_commit+0x1f4/0x1360
ext4_fsync_journal fs/ext4/fsync.c:115 [inline]
ext4_sync_file+0x336/0x6e0 fs/ext4/fsync.c:174
vfs_fsync_range+0x107/0x120 fs/sync.c:182
generic_write_sync include/linux/fs.h:2956 [inline]
iomap_dio_complete+0x2d5/0x3e0 fs/iomap/direct-io.c:116
iomap_dio_rw+0x56/0x80 fs/iomap/direct-io.c:682
ext4_dio_write_iter fs/ext4/file.c:568 [inline]
ext4_file_write_iter+0xac3/0x1200 fs/ext4/file.c:679
call_write_iter include/linux/fs.h:2162 [inline]
do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
do_iter_write+0x192/0x5c0 fs/read_write.c:851
vfs_iter_write+0x4c/0x70 fs/read_write.c:892
iter_file_splice_write+0x43a/0x790 fs/splice.c:689
do_splice_from fs/splice.c:767 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:936
splice_direct_to_actor+0x345/0x650 fs/splice.c:891
do_splice_direct+0x106/0x190 fs/splice.c:979
do_sendfile+0x675/0xc40 fs/read_write.c:1245
__do_sys_sendfile64 fs/read_write.c:1310 [inline]
__se_sys_sendfile64 fs/read_write.c:1296 [inline]
__x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881031fa820 of 8 bytes by task 10760 on cpu 1:
ext4_fc_commit+0x1c2/0x1360 fs/ext4/fast_commit.c:1205
ext4_fsync_journal fs/ext4/fsync.c:115 [inline]
ext4_sync_file+0x336/0x6e0 fs/ext4/fsync.c:174
vfs_fsync_range+0x107/0x120 fs/sync.c:182
generic_write_sync include/linux/fs.h:2956 [inline]
iomap_dio_complete+0x2d5/0x3e0 fs/iomap/direct-io.c:116
iomap_dio_rw+0x56/0x80 fs/iomap/direct-io.c:682
ext4_dio_write_iter fs/ext4/file.c:568 [inline]
ext4_file_write_iter+0xac3/0x1200 fs/ext4/file.c:679
call_write_iter include/linux/fs.h:2162 [inline]
do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
do_iter_write+0x192/0x5c0 fs/read_write.c:851
vfs_iter_write+0x4c/0x70 fs/read_write.c:892
iter_file_splice_write+0x43a/0x790 fs/splice.c:689
do_splice_from fs/splice.c:767 [inline]
direct_splice_actor+0x80/0xa0 fs/splice.c:936
splice_direct_to_actor+0x345/0x650 fs/splice.c:891
do_splice_direct+0x106/0x190 fs/splice.c:979
do_sendfile+0x675/0xc40 fs/read_write.c:1245
__do_sys_sendfile64 fs/read_write.c:1310 [inline]
__se_sys_sendfile64 fs/read_write.c:1296 [inline]
__x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x000000000000017f -> 0x0000000000000187

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10760 Comm: syz-executor.5 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.