On Fri, Jan 10, 2025 at 11:12:58AM +0100, Thomas Hellström wrote:
> Ming, Others
>
> On 6.13-rc6 I'm seeing a couple of lockdep splats which appear
> introduced by the commit
>
> f1be1788a32e ("block: model freeze & enter queue as lock for supporting
> lockdep")
The freeze lock connects all kinds of sub-system locks, that is why
we see lots of warnings after the commit is merged.
...
> #1
> [ 399.006581] ======================================================
> [ 399.006756] WARNING: possible circular locking dependency detected
> [ 399.006767] 6.12.0-rc4+ #1 Tainted: G U N
> [ 399.006776] ------------------------------------------------------
> [ 399.006801] kswapd0/116 is trying to acquire lock:
> [ 399.006810] ffff9a67a1284a28 (&q->q_usage_counter(io)){++++}-{0:0},
> at: __submit_bio+0xf0/0x1c0
> [ 399.006845]
> but task is already holding lock:
> [ 399.006856] ffffffff8a65bf00 (fs_reclaim){+.+.}-{0:0}, at:
> balance_pgdat+0xe2/0xa20
> [ 399.006874]
The above one is solved in for-6.14/block of block tree:
block: track queue dying state automatically for modeling queue freeze lockdep
>
> #2:
> [ 81.960829] ======================================================
> [ 81.961010] WARNING: possible circular locking dependency detected
> [ 81.961048] 6.12.0-rc4+ #3 Tainted: G U
...
> -> #3 (&q->limits_lock){+.+.}-{4:4}:
> [ 81.967815] __mutex_lock+0xad/0xb80
> [ 81.968133] nvme_update_ns_info_block+0x128/0x870 [nvme_core]
> [ 81.968456] nvme_update_ns_info+0x41/0x220 [nvme_core]
> [ 81.968774] nvme_alloc_ns+0x8a6/0xb50 [nvme_core]
> [ 81.969090] nvme_scan_ns+0x251/0x330 [nvme_core]
> [ 81.969401] async_run_entry_fn+0x31/0x130
> [ 81.969703] process_one_work+0x21a/0x590
> [ 81.970004] worker_thread+0x1c3/0x3b0
> [ 81.970302] kthread+0xd2/0x100
> [ 81.970603] ret_from_fork+0x31/0x50
> [ 81.970901] ret_from_fork_asm+0x1a/0x30
> [ 81.971195]
> -> #2 (&q->q_usage_counter(io)){++++}-{0:0}:
The above dependency is killed by Christoph's patch.
Thanks,
Ming
