KCSAN: data-race in __mark_inode_dirty / move_expired_inodes

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b3298500 Merge tag 'for-5.10/dm-fixes' of git://git.kernel..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ebc73d500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c949fed53798f819
dashboard link: https://syzkaller.appspot.com/bug?extid=523350e00be12594ac45
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project.git 913f6005669cfb590c99865a90bc51ed0983d09d)
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

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+523350...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / move_expired_inodes

read-write to 0xffff8881415f2550 of 8 bytes by task 3171 on cpu 0:
move_expired_inodes+0x1bf/0x490 fs/fs-writeback.c:1257
queue_io+0xe1/0x2b0 fs/fs-writeback.c:1304
wb_writeback+0x255/0x660 fs/fs-writeback.c:1892
wb_do_writeback+0x101/0x5d0 fs/fs-writeback.c:2039
wb_workfn+0xb8/0x410 fs/fs-writeback.c:2080
process_one_work+0x3e1/0x950 kernel/workqueue.c:2272
worker_thread+0x635/0xb90 kernel/workqueue.c:2418
kthread+0x1fd/0x220 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff8881415f2550 of 8 bytes by task 24129 on cpu 1:
__mark_inode_dirty+0xb7/0x740 fs/fs-writeback.c:2274
mark_buffer_dirty+0x143/0x230 fs/buffer.c:1141
__ext4_handle_dirty_metadata+0x20a/0x590 fs/ext4/ext4_jbd2.c:362
__ext4_new_inode+0x1f8f/0x3060 fs/ext4/ialloc.c:1226
ext4_symlink+0x2bc/0x770 fs/ext4/namei.c:3336
vfs_symlink+0x216/0x2d0 fs/namei.c:3960
do_symlinkat+0xee/0x280 fs/namei.c:3987
__do_sys_symlink fs/namei.c:4006 [inline]
__se_sys_symlink fs/namei.c:4004 [inline]
__x64_sys_symlink+0x32/0x40 fs/namei.c:4004
do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24129 Comm: syz-executor.0 Not tainted 5.10.0-rc6-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.