[0/2,v2] block: Fix deadlock when merging requests with BFQ

Message ID	20210524100416.3578-1-jack@suse.cz (mailing list archive)
Headers	show Return-Path: <linux-block-owner@kernel.org> From: Jan Kara <jack@suse.cz> To: Jens Axboe <axboe@kernel.dk> Cc: <linux-block@vger.kernel.org>, Khazhy Kumykov <khazhy@google.com>, Paolo Valente <paolo.valente@linaro.org>, Ming Lei <ming.lei@redhat.com>, Jan Kara <jack@suse.cz> Subject: [PATCH 0/2 v2] block: Fix deadlock when merging requests with BFQ Date: Mon, 24 May 2021 12:04:14 +0200 Message-Id: <20210524100416.3578-1-jack@suse.cz> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	block: Fix deadlock when merging requests with BFQ \| expand [0/2,v2] block: Fix deadlock when merging requests with BFQ [1/2] bfq: Remove merged request already in bfq_requests_merged() [2/2] blk: Fix lock inversion between ioc lock and bfqd lock

Message ID

20210524100416.3578-1-jack@suse.cz (mailing list archive)

Headers

From: Jan Kara <jack@suse.cz>
To: Jens Axboe <axboe@kernel.dk>
Cc: <linux-block@vger.kernel.org>, Khazhy Kumykov <khazhy@google.com>,
        Paolo Valente <paolo.valente@linaro.org>,
        Ming Lei <ming.lei@redhat.com>, Jan Kara <jack@suse.cz>
Subject: [PATCH 0/2 v2] block: Fix deadlock when merging requests with BFQ
Date: Mon, 24 May 2021 12:04:14 +0200
Message-Id: <20210524100416.3578-1-jack@suse.cz>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Series

block: Fix deadlock when merging requests with BFQ | expand

Message

Jan Kara May 24, 2021, 10:04 a.m. UTC

Hello,

This patch series fixes a lockdep complaint and a possible deadlock that
can happen when blk_mq_sched_try_insert_merge() merges and frees a request.

Changes since v1:
* Remove patch disabling recursing request merging during request insertion
* Modified BFQ to cleanup merged request already in its .merge_requests handler
* Added code to handle multiple requests that need freeing after being merged

								Honza