run fstests shared/298 at 2017-10-09 20:38:50

======================================================
WARNING: possible circular locking dependency detected
4.14.0-rc4-ceph-gc9ed9bcb0121 #1 Not tainted
------------------------------------------------------
loop0/15423 is trying to acquire lock:
 (jbd2_handle){++++}, at: [<ffffffffbd37b694>] start_this_handle+0x104/0x450

but now in release context of a crosslock acquired at the following:
 ((complete)&done#3){+.+.}, at: [<ffffffffbd45c79b>] submit_bio_wait+0x8b/0xc0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 ((complete)&done#3){+.+.}:
       __lock_acquire+0x111f/0x1150
       lock_acquire+0xed/0x1e0
       wait_for_completion_io+0x53/0x1b0
       submit_bio_wait+0x8b/0xc0
       blkdev_issue_zeroout+0xcf/0x1b0
       ext4_init_inode_table+0x153/0x339
       ext4_lazyinit_thread+0x2bc/0x3d0
       kthread+0x152/0x190
       ret_from_fork+0x2a/0x40

-> #1 (&meta_group_info[i]->alloc_sem){++++}:
       __lock_acquire+0x111f/0x1150
       lock_acquire+0xed/0x1e0
       down_read+0x43/0x70
       __ext4_new_inode+0xc4a/0x1470
       ext4_create+0x103/0x190
       lookup_open+0x78a/0x880
       path_openat+0x3c0/0xad0
       do_filp_open+0x8a/0xf0
       do_sys_open+0x11b/0x1f0
       SyS_open+0x1e/0x20
       entry_SYSCALL_64_fastpath+0x23/0xc2

-> #0 (jbd2_handle){++++}:
       start_this_handle+0x167/0x450
       jbd2__journal_start+0xdb/0x2b0
       __ext4_journal_start_sb+0x89/0x1e0
       ext4_punch_hole+0x229/0x570
       ext4_fallocate+0x19d/0xb20

other info that might help us debug this:

Chain exists of:
  jbd2_handle --> &meta_group_info[i]->alloc_sem --> (complete)&done#3

 Possible unsafe locking scenario by crosslock:

       CPU0                    CPU1
       ----                    ----
  lock(&meta_group_info[i]->alloc_sem);
  lock((complete)&done#3);
                               lock(jbd2_handle);
                               unlock((complete)&done#3);

 *** DEADLOCK ***

1 lock held by loop0/15423:
 #0:  (&x->wait#17){..-.}, at: [<ffffffffbd0d678d>] complete+0x1d/0x60

stack backtrace:
CPU: 1 PID: 15423 Comm: loop0 Not tainted 4.14.0-rc4-ceph-gc9ed9bcb0121 #1
Hardware name: Supermicro X8SIL/X8SIL, BIOS 1.0c 02/25/2010
Call Trace:
 dump_stack+0x85/0xc7
 print_circular_bug+0x1eb/0x2e0
 ? print_bfs_bug+0x40/0x40
 check_prev_add+0x396/0x7e0
 ? __lock_acquire+0x705/0x1150
 lock_commit_crosslock+0x3db/0x5e0
 ? lock_commit_crosslock+0x3db/0x5e0
 complete+0x29/0x60
 submit_bio_wait_endio+0x12/0x20
 bio_endio+0x9f/0x1e0
 blk_update_request+0xc4/0x3c0
 blk_mq_end_request+0x1e/0x70
 lo_complete_rq+0x30/0x80
 __blk_mq_complete_request+0xa3/0x160
 blk_mq_complete_request+0x16/0x20
 loop_queue_work+0x5f/0x9b0
 ? find_held_lock+0x39/0xb0
 ? kthread_worker_fn+0x9c/0x200
 ? trace_hardirqs_on_caller+0x11f/0x190
 kthread_worker_fn+0xbf/0x200
 loop_kthread_worker_fn+0x1e/0x20
 kthread+0x152/0x190
 ? loop_get_status64+0x90/0x90
 ? kthread_stop+0x2a0/0x2a0
 ret_from_fork+0x2a/0x40