Commit 9e6a6b12 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

nvme: paring quiesce/unquiesce 



The current blk_mq_quiesce_queue() and blk_mq_unquiesce_queue() always
stops and starts the queue unconditionally. And there can be concurrent
quiesce/unquiesce coming from different unrelated code paths, so
unquiesce may come unexpectedly and start queue too early.

Prepare for supporting concurrent quiesce/unquiesce from multiple
contexts, so that we can address the above issue.

NVMe has very complicated quiesce/unquiesce use pattern, add one atomic
bit for makeiing sure that blk-mq quiece/unquiesce is always called in
pair.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211014081710.1871747-5-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ebc9b952

drivers/nvme/host/core.c

+8 −4
Original line number Diff line number Diff line
@@ -4468,11 +4468,13 @@ EXPORT_SYMBOL_GPL(nvme_init_ctrl); 


static void nvme_start_ns_queue(struct nvme_ns *ns)

{

	if (test_and_clear_bit(NVME_NS_STOPPED, &ns->flags))

		blk_mq_unquiesce_queue(ns->queue);

}



static void nvme_stop_ns_queue(struct nvme_ns *ns)

{

	if (!test_and_set_bit(NVME_NS_STOPPED, &ns->flags))

		blk_mq_quiesce_queue(ns->queue);

}
@@ -4591,12 +4593,14 @@ EXPORT_SYMBOL_GPL(nvme_start_queues); 


void nvme_stop_admin_queue(struct nvme_ctrl *ctrl)

{

	if (!test_and_set_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))

		blk_mq_quiesce_queue(ctrl->admin_q);

}

EXPORT_SYMBOL_GPL(nvme_stop_admin_queue);



void nvme_start_admin_queue(struct nvme_ctrl *ctrl)

{

	if (test_and_clear_bit(NVME_CTRL_ADMIN_Q_STOPPED, &ctrl->flags))

		blk_mq_unquiesce_queue(ctrl->admin_q);

}

EXPORT_SYMBOL_GPL(nvme_start_admin_queue);

drivers/nvme/host/nvme.h

+2 −0
Original line number Diff line number Diff line
@@ -342,6 +342,7 @@ struct nvme_ctrl { 
	int nr_reconnects;

	unsigned long flags;

#define NVME_CTRL_FAILFAST_EXPIRED	0

#define NVME_CTRL_ADMIN_Q_STOPPED	1

	struct nvmf_ctrl_options *opts;



	struct page *discard_page;
@@ -463,6 +464,7 @@ struct nvme_ns { 
#define NVME_NS_ANA_PENDING	2

#define NVME_NS_FORCE_RO	3

#define NVME_NS_READY		4

#define NVME_NS_STOPPED		5



	struct cdev		cdev;

	struct device		cdev_device;