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From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>
Cc: linux-block@vger.kernel.org, Ming Lei <ming.lei@redhat.com>,
	Yi Zhang <yi.zhang@redhat.com>,
	Bart Van Assche <bvanassche@acm.org>
Subject: [PATCH V2 0/2] block: fix race between adding wbt and normal IO
Date: Tue,  8 Jun 2021 15:19:01 +0800	[thread overview]
Message-ID: <20210608071903.431195-1-ming.lei@redhat.com> (raw)

Hello,

Yi reported several kernel panics on:

[16687.001777] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
...
[16687.163549] pc : __rq_qos_track+0x38/0x60

or

[  997.690455] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020
...
[  997.850347] pc : __rq_qos_done+0x2c/0x50

Turns out it is caused by race between adding wbt and normal IO.

Fix the issue by freezing request queue when adding/deleting rq qos.

V2:
	- switch to the approach of freezing queue, which is more generic
	  than V1.


Ming Lei (2):
  block: fix race between adding/removing rq qos and normal IO
  block: mark queue init done at the end of blk_register_queue

 block/blk-rq-qos.h | 13 +++++++++++++
 block/blk-sysfs.c  | 29 +++++++++++++++--------------
 2 files changed, 28 insertions(+), 14 deletions(-)

Cc: Yi Zhang <yi.zhang@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
-- 
2.31.1


             reply	other threads:[~2021-06-08  7:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-08  7:19 Ming Lei [this message]
2021-06-08  7:19 ` [PATCH V2 1/2] block: fix race between adding/removing rq qos and normal IO Ming Lei
2021-06-08 15:04   ` Bart Van Assche
2021-06-09  0:55     ` Ming Lei
2021-06-08  7:19 ` [PATCH V2 2/2] block: mark queue init done at the end of blk_register_queue Ming Lei

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