From: Bart Van Assche <bvanassche@acm.org>
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>,
Hannes Reinecke <hare@suse.com>,
Greg KH <gregkh@linuxfoundation.org>,
Mike Snitzer <snitzer@redhat.com>
Subject: Re: [PATCH] block: don't release queue's sysfs lock during switching elevator
Date: Tue, 24 Sep 2019 11:37:09 -0700 [thread overview]
Message-ID: <bc5864cd-a62b-d6d5-2d69-6ec03983508b@acm.org> (raw)
In-Reply-To: <20190923151209.7466-1-ming.lei@redhat.com>
On 9/23/19 8:12 AM, Ming Lei wrote:
> @@ -523,11 +521,9 @@ void elv_unregister_queue(struct request_queue *q)
> kobject_uevent(&e->kobj, KOBJ_REMOVE);
> kobject_del(&e->kobj);
>
> - mutex_lock(&q->sysfs_lock);
> e->registered = 0;
> /* Re-enable throttling in case elevator disabled it */
> wbt_enable_default(q);
> - mutex_unlock(&q->sysfs_lock);
> }
> }
Does this patch cause sysfs_lock to be held around
kobject_del(&e->kobj)? Since sysfs_lock is locked from inside
elv_attr_show() and elv_attr_store(), does this mean that this patch
reintroduces the lock inversion problem that was fixed recently?
Thanks,
Bart.
next prev parent reply other threads:[~2019-09-24 18:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-23 15:12 [PATCH] block: don't release queue's sysfs lock during switching elevator Ming Lei
2019-09-24 18:37 ` Bart Van Assche [this message]
2019-09-25 0:13 ` Ming Lei
2019-09-25 23:40 ` Bart Van Assche
2019-09-26 6:46 ` Jens Axboe
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