From 6cc8e7430801fa238bd7d3acae1eb406c6e02fe1 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Tue, 26 Jan 2021 09:46:30 -0500 Subject: loop: scale loop device by introducing per device lock Currently, loop device has only one global lock: loop_ctl_mutex. This becomes hot in scenarios where many loop devices are used. Scale it by introducing per-device lock: lo_mutex that protects modifications of all fields in struct loop_device. Keep loop_ctl_mutex to protect global data: loop_index_idr, loop_lookup, loop_add. The new lock ordering requirement is that loop_ctl_mutex must be taken before lo_mutex. Signed-off-by: Pavel Tatashin Reviewed-by: Tyler Hicks Reviewed-by: Petr Vorel Signed-off-by: Jens Axboe --- drivers/block/loop.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/block/loop.h') diff --git a/drivers/block/loop.h b/drivers/block/loop.h index af75a5ee4094..a3c04f310672 100644 --- a/drivers/block/loop.h +++ b/drivers/block/loop.h @@ -62,6 +62,7 @@ struct loop_device { struct request_queue *lo_queue; struct blk_mq_tag_set tag_set; struct gendisk *lo_disk; + struct mutex lo_mutex; }; struct loop_cmd { -- cgit v1.2.3