Commit 8023e144 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

block: move the poll flag to queue_limits 



Move the poll flag into the queue_limits feature field so that it can
be set atomically with the queue frozen.

Stacking drivers are simplified in that they now can simply set the
flag, and blk_stack_limits will clear it when the features is not
supported by any of the underlying devices.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-22-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f467fee4

block/blk-core.c

+2 −3
Original line number Diff line number Diff line
@@ -791,7 +791,7 @@ void submit_bio_noacct(struct bio *bio) 
		}

	}



	if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))

	if (!(q->limits.features & BLK_FEAT_POLL))

		bio_clear_polled(bio);



	switch (bio_op(bio)) {
@@ -915,8 +915,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags) 
		return 0;



	q = bdev_get_queue(bdev);

	if (cookie == BLK_QC_T_NONE ||

	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))

	if (cookie == BLK_QC_T_NONE || !(q->limits.features & BLK_FEAT_POLL))

		return 0;



	blk_flush_plug(current->plug, false);

block/blk-mq-debugfs.c

+0 −1
Original line number Diff line number Diff line
@@ -87,7 +87,6 @@ static const char *const blk_queue_flag_name[] = { 
	QUEUE_FLAG_NAME(NOXMERGES),

	QUEUE_FLAG_NAME(SAME_FORCE),

	QUEUE_FLAG_NAME(INIT_DONE),

	QUEUE_FLAG_NAME(POLL),

	QUEUE_FLAG_NAME(STATS),

	QUEUE_FLAG_NAME(REGISTERED),

	QUEUE_FLAG_NAME(QUIESCED),

block/blk-mq.c

+18 −13
Original line number Diff line number Diff line
@@ -4109,6 +4109,12 @@ void blk_mq_release(struct request_queue *q) 
	blk_mq_sysfs_deinit(q);

}



static bool blk_mq_can_poll(struct blk_mq_tag_set *set)

{

	return set->nr_maps > HCTX_TYPE_POLL &&

		set->map[HCTX_TYPE_POLL].nr_queues;

}



struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set,

		struct queue_limits *lim, void *queuedata)

{
@@ -4119,6 +4125,8 @@ struct request_queue *blk_mq_alloc_queue(struct blk_mq_tag_set *set, 
	if (!lim)

		lim = &default_lim;

	lim->features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT;

	if (blk_mq_can_poll(set))

		lim->features |= BLK_FEAT_POLL;



	q = blk_alloc_queue(lim, set->numa_node);

	if (IS_ERR(q))
@@ -4273,17 +4281,6 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, 
	mutex_unlock(&q->sysfs_lock);

}



static void blk_mq_update_poll_flag(struct request_queue *q)

{

	struct blk_mq_tag_set *set = q->tag_set;



	if (set->nr_maps > HCTX_TYPE_POLL &&

	    set->map[HCTX_TYPE_POLL].nr_queues)

		blk_queue_flag_set(QUEUE_FLAG_POLL, q);

	else

		blk_queue_flag_clear(QUEUE_FLAG_POLL, q);

}



int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,

		struct request_queue *q)

{
@@ -4311,7 +4308,6 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, 
	q->tag_set = set;



	q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;

	blk_mq_update_poll_flag(q);



	INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);

	INIT_LIST_HEAD(&q->flush_list);
@@ -4798,8 +4794,10 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, 
fallback:

	blk_mq_update_queue_map(set);

	list_for_each_entry(q, &set->tag_list, tag_set_list) {

		struct queue_limits lim;



		blk_mq_realloc_hw_ctxs(set, q);

		blk_mq_update_poll_flag(q);



		if (q->nr_hw_queues != set->nr_hw_queues) {

			int i = prev_nr_hw_queues;
@@ -4811,6 +4809,13 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, 
			set->nr_hw_queues = prev_nr_hw_queues;

			goto fallback;

		}

		lim = queue_limits_start_update(q);

		if (blk_mq_can_poll(set))

			lim.features |= BLK_FEAT_POLL;

		else

			lim.features &= ~BLK_FEAT_POLL;

		if (queue_limits_commit_update(q, &lim) < 0)

			pr_warn("updating the poll flag failed\n");

		blk_mq_map_swqueue(q);

	}

block/blk-settings.c

+6 −4
Original line number Diff line number Diff line
@@ -460,13 +460,15 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, 
	t->features |= (b->features & BLK_FEAT_INHERIT_MASK);



	/*

	 * BLK_FEAT_NOWAIT needs to be supported both by the stacking driver

	 * and all underlying devices.  The stacking driver sets the flag

	 * before stacking the limits, and this will clear the flag if any

	 * of the underlying devices does not support it.

	 * BLK_FEAT_NOWAIT and BLK_FEAT_POLL need to be supported both by the

	 * stacking driver and all underlying devices.  The stacking driver sets

	 * the flags before stacking the limits, and this will clear the flags

	 * if any of the underlying devices does not support it.

	 */

	if (!(b->features & BLK_FEAT_NOWAIT))

		t->features &= ~BLK_FEAT_NOWAIT;

	if (!(b->features & BLK_FEAT_POLL))

		t->features &= ~BLK_FEAT_POLL;



	t->max_sectors = min_not_zero(t->max_sectors, b->max_sectors);

	t->max_user_sectors = min_not_zero(t->max_user_sectors,

block/blk-sysfs.c

+2 −2
Original line number Diff line number Diff line
@@ -394,13 +394,13 @@ static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page, 


static ssize_t queue_poll_show(struct request_queue *q, char *page)

{

	return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);

	return queue_var_show(q->limits.features & BLK_FEAT_POLL, page);

}



static ssize_t queue_poll_store(struct request_queue *q, const char *page,

				size_t count)

{

	if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))

	if (!(q->limits.features & BLK_FEAT_POLL))

		return -EINVAL;

	pr_info_ratelimited("writes to the poll attribute are ignored.\n");

	pr_info_ratelimited("please use driver specific parameters instead.\n");