linux-kernel - [PATCH 1/2] blk-stat: fix QUEUE_FLAG

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-next>] [day] [month] [year] [list]

Message-Id: <20230412160754.1981705-1-chengming.zhou@linux.dev>
Date:   Thu, 13 Apr 2023 00:07:53 +0800
From:   chengming.zhou@...ux.dev
To:     axboe@...nel.dk, tj@...nel.org
Cc:     josef@...icpanda.com, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
        Chengming Zhou <zhouchengming@...edance.com>
Subject: [PATCH 1/2] blk-stat: fix QUEUE_FLAG_STATS clear

From: Chengming Zhou <zhouchengming@...edance.com>

We need to set QUEUE_FLAG_STATS for two cases:
1. blk_stat_enable_accounting()
2. blk_stat_add_callback()

So we should clear it only when ((q->stats->accounting == 0) &&
list_empty(&q->stats->callbacks)).

blk_stat_disable_accounting() only check if q->stats->accounting
is 0 before clear the flag, this patch fix it.

Also add list_empty(&q->stats->callbacks)) check when enable, or
the flag is already set.

Signed-off-by: Chengming Zhou <zhouchengming@...edance.com>
---
 block/blk-stat.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-stat.c b/block/blk-stat.c
index 74a1a8c32d86..bc7e0ed81642 100644
--- a/block/blk-stat.c
+++ b/block/blk-stat.c
@@ -190,7 +190,7 @@ void blk_stat_disable_accounting(struct request_queue *q)
 	unsigned long flags;
 
 	spin_lock_irqsave(&q->stats->lock, flags);
-	if (!--q->stats->accounting)
+	if (!--q->stats->accounting && list_empty(&q->stats->callbacks))
 		blk_queue_flag_clear(QUEUE_FLAG_STATS, q);
 	spin_unlock_irqrestore(&q->stats->lock, flags);
 }
@@ -201,7 +201,7 @@ void blk_stat_enable_accounting(struct request_queue *q)
 	unsigned long flags;
 
 	spin_lock_irqsave(&q->stats->lock, flags);
-	if (!q->stats->accounting++)
+	if (!q->stats->accounting++ && list_empty(&q->stats->callbacks))
 		blk_queue_flag_set(QUEUE_FLAG_STATS, q);
 	spin_unlock_irqrestore(&q->stats->lock, flags);
 }
-- 
2.39.2