linux-kernel - [PATCH 4.19 267/271] blk-iolatency: clear use

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]

Message-Id: <20190724191718.116443451@linuxfoundation.org>
Date:   Wed, 24 Jul 2019 21:22:16 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Tejun Heo <tj@...nel.org>,
        Josef Bacik <jbacik@...com>, Jens Axboe <axboe@...nel.dk>
Subject: [PATCH 4.19 267/271] blk-iolatency: clear use_delay when io.latency is set to zero

From: Tejun Heo <tj@...nel.org>

commit 5de0073fcd50cc1f150895a7bb04d3cf8067b1d7 upstream.

If use_delay was non-zero when the latency target of a cgroup was set
to zero, it will stay stuck until io.latency is enabled on the cgroup
again.  This keeps readahead disabled for the cgroup impacting
performance negatively.

Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Josef Bacik <jbacik@...com>
Fixes: d70675121546 ("block: introduce blk-iolatency io controller")
Cc: stable@...r.kernel.org # v4.19+
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 block/blk-iolatency.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -746,8 +746,10 @@ static int iolatency_set_min_lat_nsec(st
 
 	if (!oldval && val)
 		return 1;
-	if (oldval && !val)
+	if (oldval && !val) {
+		blkcg_clear_delay(blkg);
 		return -1;
+	}
 	return 0;
 }