On Wed 14-07-21 16:26:52, Greg Kroah-Hartman wrote:
On Wed, Jul 14, 2021 at 07:29:26PM +0530, Naresh Kamboju wrote:
On Wed, 14 Jul 2021 at 19:22, Naresh Kamboju naresh.kamboju@linaro.org wrote:
On Wed, 14 Jul 2021 at 19:01, Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
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My two cents, While running ssuite long running stress testing we have noticed deadlock.
So if you drop that, all works well? I'll go drop that from the queues now.
Let me drop that patch and test it again.
Crash log,
[ 1957.278399] ============================================ [ 1957.283717] WARNING: possible recursive locking detected [ 1957.289031] 5.13.2-rc1 #1 Not tainted [ 1957.292703] -------------------------------------------- [ 1957.298016] kworker/u8:7/236 is trying to acquire lock: [ 1957.303241] ffff8cc203f92c38 (&bfqd->lock){-.-.}-{2:2}, at: bfq_finish_requeue_request+0x55/0x500 [bfq] [ 1957.312643] [ 1957.312643] but task is already holding lock: [ 1957.318467] ffff8cc203f92c38 (&bfqd->lock){-.-.}-{2:2}, at: bfq_insert_requests+0x81/0x1750 [bfq] [ 1957.327334] [ 1957.327334] other info that might help us debug this: [ 1957.333852] Possible unsafe locking scenario: [ 1957.333852] [ 1957.339762] CPU0 [ 1957.342206] ---- [ 1957.344651] lock(&bfqd->lock); [ 1957.347873] lock(&bfqd->lock); [ 1957.351097] [ 1957.351097] *** DEADLOCK *** [ 1957.351097]
Also noticed on stable-rc 5.12.17-rc1.
I dropped the same patch from there as well already, thanks.
OK, when you dropped this patch, please also drop upstream commit fd2ef39cc9a6b ("blk: Fix lock inversion between ioc lock and bfqd lock"). Because without BFQ patch this block layer patch could cause some use-after-free issues. I'll have a look if I can understand why BFQ patch causes problems in stable kernels...
Honza