======================================================
WARNING: possible circular locking dependency detected
4.19.211-syzkaller #0 Not tainted
------------------------------------------------------
kworker/0:0/4533 is trying to acquire lock:
00000000d103cd20 (&sb->s_type->i_mutex_key#10){++++}, at: inode_lock include/linux/fs.h:748 [inline]
00000000d103cd20 (&sb->s_type->i_mutex_key#10){++++}, at: __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989

but task is already holding lock:
00000000b08aae89 ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 ((work_completion)(&dio->complete_work)){+.+.}:
       worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
       kthread+0x33f/0x460 kernel/kthread.c:259
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

-> #1 ((wq_completion)"dio/%s"sb->s_id){+.+.}:
       drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826
       destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183
       __alloc_workqueue_key+0xb76/0xed0 kernel/workqueue.c:4160
       sb_init_dio_done_wq+0x34/0x90 fs/direct-io.c:623
       do_blockdev_direct_IO fs/direct-io.c:1285 [inline]
       __blockdev_direct_IO+0x5f55/0xef40 fs/direct-io.c:1419
       ext4_direct_IO_write fs/ext4/inode.c:3777 [inline]
       ext4_direct_IO+0xae4/0x1c50 fs/ext4/inode.c:3915
       generic_file_direct_write+0x208/0x4a0 mm/filemap.c:3073
       __generic_file_write_iter+0x2d0/0x610 mm/filemap.c:3252
       ext4_file_write_iter+0x957/0xf20 fs/ext4/file.c:272
       call_write_iter include/linux/fs.h:1821 [inline]
       aio_write+0x37f/0x5c0 fs/aio.c:1574
       __io_submit_one fs/aio.c:1858 [inline]
       io_submit_one+0xecd/0x20c0 fs/aio.c:1909
       __do_sys_io_submit fs/aio.c:1953 [inline]
       __se_sys_io_submit+0x11b/0x4a0 fs/aio.c:1924
       do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #0 (&sb->s_type->i_mutex_key#10){++++}:
       down_write+0x34/0x90 kernel/locking/rwsem.c:70
       inode_lock include/linux/fs.h:748 [inline]
       __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989
       ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118
       vfs_fsync_range+0x13a/0x220 fs/sync.c:197
       generic_write_sync include/linux/fs.h:2750 [inline]
       dio_complete+0x763/0xac0 fs/direct-io.c:329
       process_one_work+0x864/0x1570 kernel/workqueue.c:2153
       worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
       kthread+0x33f/0x460 kernel/kthread.c:259
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

other info that might help us debug this:

Chain exists of:
  &sb->s_type->i_mutex_key#10 --> (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work)

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock((work_completion)(&dio->complete_work));
                               lock((wq_completion)"dio/%s"sb->s_id);
                               lock((work_completion)(&dio->complete_work));
  lock(&sb->s_type->i_mutex_key#10);

 *** DEADLOCK ***

2 locks held by kworker/0:0/4533:
 #0: 00000000513d8814 ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124
 #1: 00000000b08aae89 ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128

stack backtrace:
CPU: 0 PID: 4533 Comm: kworker/0:0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: dio/sda1 dio_aio_complete_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222
 check_prev_add kernel/locking/lockdep.c:1866 [inline]
 check_prevs_add kernel/locking/lockdep.c:1979 [inline]
 validate_chain kernel/locking/lockdep.c:2420 [inline]
 __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 down_write+0x34/0x90 kernel/locking/rwsem.c:70
 inode_lock include/linux/fs.h:748 [inline]
 __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:989
 ext4_sync_file+0xa35/0x1420 fs/ext4/fsync.c:118
 vfs_fsync_range+0x13a/0x220 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2750 [inline]
 dio_complete+0x763/0xac0 fs/direct-io.c:329
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
9pnet: p9_fd_create_tcp (10044): problem connecting socket to 127.0.0.1