linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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 V3 0/2] block: fix race between adding wbt and normal IO
Date: Wed,  9 Jun 2021 09:58:20 +0800	[thread overview]
Message-ID: <20210609015822.103433-1-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.

V3:
	- use ->queue_lock for protecting concurrent adding/deleting rqos on
	  same queue

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 | 24 ++++++++++++++++++++++++
 block/blk-sysfs.c  | 29 +++++++++++++++--------------
 2 files changed, 39 insertions(+), 14 deletions(-)

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


             reply	other threads:[~2021-06-09  1:58 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-09  1:58 Ming Lei [this message]
2021-06-09  1:58 ` [PATCH V3 1/2] block: fix race between adding/removing rq qos " Ming Lei
2021-06-09 20:05   ` Bart Van Assche
2021-06-09  1:58 ` [PATCH V3 2/2] block: mark queue init done at the end of blk_register_queue Ming Lei
2021-06-09 20:09   ` Bart Van Assche
2021-06-10  0:45 ` [PATCH V3 0/2] block: fix race between adding wbt and normal IO Yi Zhang
2021-06-14 21:55 ` Ming Lei
2021-06-16 14:11   ` Ming Lei
2021-06-16 14:42 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210609015822.103433-1-ming.lei@redhat.com \
    --to=ming.lei@redhat.com \
    --cc=axboe@kernel.dk \
    --cc=bvanassche@acm.org \
    --cc=hch@lst.de \
    --cc=linux-block@vger.kernel.org \
    --cc=yi.zhang@redhat.com \
    --subject='Re: [PATCH V3 0/2] block: fix race between adding wbt and normal IO' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).