Recursive locking complaint with nvme-5.13 branch

[Bart Van Assche]

Hi,

If I boot a VM with the nvme-5.13 branch (commit 24e238c92186
("nvme: warn of unhandled effects only once")) then the complaint
shown below is reported. Is this a known issue?

Thanks,

Bart.


============================================
WARNING: possible recursive locking detected
5.12.0-rc3-dbg+ #6 Not tainted
--------------------------------------------
systemd-udevd/299 is trying to acquire lock:
ffff88811b1e80a0 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x85/0x350

but task is already holding lock:
ffff8881134100a0 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x1a9/0x350

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&bdev->bd_mutex);
  lock(&bdev->bd_mutex);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by systemd-udevd/299:
 #0: ffff8881134100a0 (&bdev->bd_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x1a9/0x350
 #1: ffffffffa10269c8 (pktcdvd_mutex){+.+.}-{3:3}, at: pkt_open+0x22/0x15a [pktcdvd]
 #2: ffffffffa1025788 (&ctl_mutex#2){+.+.}-{3:3}, at: pkt_open+0x30/0x15a [pktcdvd]

stack backtrace:
CPU: 6 PID: 299 Comm: systemd-udevd Not tainted 5.12.0-rc3-dbg+ #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
Call Trace:
 show_stack+0x52/0x58
 dump_stack+0x9d/0xcf
 print_deadlock_bug.cold+0x131/0x136
 validate_chain+0x6d3/0xc70
 ? check_prev_add+0x11d0/0x11d0
 __lock_acquire+0x500/0x920
 ? start_flush_work+0x375/0x510
 ? __this_cpu_preempt_check+0x13/0x20
 lock_acquire.part.0+0x117/0x210
 ? blkdev_get_by_dev+0x85/0x350
 ? rcu_read_unlock+0x50/0x50
 ? __this_cpu_preempt_check+0x13/0x20
 ? lock_is_held_type+0xdb/0x130
 lock_acquire+0x9b/0x1a0
 ? blkdev_get_by_dev+0x85/0x350
 __mutex_lock+0x117/0xb60
 ? blkdev_get_by_dev+0x85/0x350
 ? blkdev_get_by_dev+0x85/0x350
 ? mutex_lock_io_nested+0xa70/0xa70
 ? __kasan_check_write+0x14/0x20
 ? __mutex_unlock_slowpath+0xa7/0x290
 ? __ww_mutex_check_kill+0x160/0x160
 ? trace_hardirqs_on+0x2b/0x130
 ? mutex_unlock+0x12/0x20
 ? disk_block_events+0x92/0xc0
 mutex_lock_nested+0x1b/0x20
 blkdev_get_by_dev+0x85/0x350
 ? __mutex_lock+0x49c/0xb60
 pkt_open_dev+0x7f/0x370 [pktcdvd]
 ? pkt_open_write+0x120/0x120 [pktcdvd]
 ? __ww_mutex_check_kill+0x160/0x160
 pkt_open+0xfd/0x15a [pktcdvd]
 __blkdev_get+0xa3/0x450
 blkdev_get_by_dev+0x1b4/0x350
 ? __kasan_check_read+0x11/0x20
 blkdev_open+0xa4/0x120
 do_dentry_open+0x27d/0x690
 ? blkdev_get_by_dev+0x350/0x350
 vfs_open+0x58/0x60
 do_open+0x316/0x4a0
 path_openat+0x1b8/0x260
 ? do_tmpfile+0x160/0x160
 ? __this_cpu_preempt_check+0x13/0x20
 do_filp_open+0x12d/0x240
 ? may_open_dev+0x60/0x60
 ? __kasan_check_read+0x11/0x20
 ? do_raw_spin_unlock+0x98/0xf0
 ? preempt_count_sub+0x18/0xc0
 ? _raw_spin_unlock+0x2d/0x50
 do_sys_openat2+0xe9/0x260
 ? build_open_flags+0x2a0/0x2a0
 __x64_sys_openat+0xd3/0x130
 ? __ia32_sys_open+0x110/0x110
 ? __secure_computing+0x74/0x140
 ? syscall_trace_enter.constprop.0+0x71/0x230
 do_syscall_64+0x32/0x80
 entry_SYSCALL_64_after_hwframe+0x44/0xae