From 776687bce42bb22cce48b5da950e48ebbb9a948f Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 1 Jul 2014 10:29:17 -0600 Subject: block, blk-mq: draining can't be skipped even if bypass_depth was non-zero Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue() skip queue draining if bypass_depth was already above zero. The assumption is that the one which bumped the bypass_depth should have performed draining already; however, there's nothing which prevents a new instance of bypassing/freezing from starting before the previous one finishes draining. The current code may allow the later bypassing/freezing instances to complete while there still are in-flight requests which haven't finished draining. Fix it by draining regardless of bypass_depth. We still skip draining from blk_queue_bypass_start() while the queue is initializing to avoid introducing excessive delays during boot. INIT_DONE setting is moved above the initial blk_queue_bypass_end() so that bypassing attempts can't slip inbetween. Signed-off-by: Tejun Heo Cc: Jens Axboe Cc: Nicholas A. Bellinger Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'block/blk-sysfs.c') diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 23321fbab293..4db5abf96b9e 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -554,8 +554,8 @@ int blk_register_queue(struct gendisk *disk) * Initialization must be complete by now. Finish the initial * bypass from queue allocation. */ - blk_queue_bypass_end(q); queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q); + blk_queue_bypass_end(q); ret = blk_trace_init_sysfs(dev); if (ret) -- cgit v1.2.3-59-g8ed1b