Re: [PATCH v1 3/3] blk-mq: start to freeze queue just after setting dying
From: Hannes Reinecke <hare@suse.de>
Date: 2017-03-18 11:45:02
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On 03/17/2017 10:57 AM, Ming Lei wrote:
Before commit 780db2071a(blk-mq: decouble blk-mq freezing from generic bypassing), the dying flag is checked before entering queue, and Tejun converts the checking into .mq_freeze_depth, and assumes the counter is increased just after dying flag is set. Unfortunately we doesn't do that in blk_set_queue_dying(). This patch calls blk_mq_freeze_queue_start() for blk-mq in blk_set_queue_dying(), so that we can block new I/O coming once the queue is set as dying. Given blk_set_queue_dying() is always called in remove path of block device, and queue will be cleaned up later, we don't need to worry about undoing the counter. Cc: Bart Van Assche <redacted> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Ming Lei <tom.leiming@gmail.com> --- block/blk-core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
Reviewed-by: Hannes Reinecke <hare@suse.com> Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N�rnberg GF: J. Hawn, J. Guild, F. Imend�rffer, HRB 16746 (AG N�rnberg)