linux-kernel - [PATCH 5.4 275/411] bfq: Drop pointless unlock-lock pair

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 13 Jun 2022 12:09:08 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "yukuai (C)" <yukuai3@...wei.com>, Jan Kara <jack@...e.cz>,
        Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 5.4 275/411] bfq: Drop pointless unlock-lock pair

From: Jan Kara <jack@...e.cz>

commit fc84e1f941b91221092da5b3102ec82da24c5673 upstream.

In bfq_insert_request() we unlock bfqd->lock only to call
trace_block_rq_insert() and then lock bfqd->lock again. This is really
pointless since tracing is disabled if we really care about performance
and even if the tracepoint is enabled, it is a quick call.

CC: stable@...r.kernel.org
Tested-by: "yukuai (C)" <yukuai3@...wei.com>
Signed-off-by: Jan Kara <jack@...e.cz>
Reviewed-by: Christoph Hellwig <hch@....de>
Link: https://lore.kernel.org/r/20220401102752.8599-5-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 block/bfq-iosched.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5529,11 +5529,8 @@ static void bfq_insert_request(struct bl
 		return;
 	}
 
-	spin_unlock_irq(&bfqd->lock);
-
 	blk_mq_sched_request_inserted(rq);
 
-	spin_lock_irq(&bfqd->lock);
 	bfqq = bfq_init_rq(rq);
 	if (!bfqq || at_head || blk_rq_is_passthrough(rq)) {
 		if (at_head)