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	block: remove legacy rq tagging
It's now unused, kill it. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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					 8 changed files with 3 additions and 517 deletions
				
			
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						 | 
				
			
			@ -65,7 +65,6 @@ Description of Contents:
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    3.2.3 I/O completion
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    3.2.4 Implications for drivers that do not interpret bios (don't handle
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 	  multiple segments)
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    3.2.5 Request command tagging
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  3.3 I/O submission
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4. The I/O scheduler
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5. Scalability related changes
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			@ -708,93 +707,6 @@ is crossed on completion of a transfer. (The end*request* functions should
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be used if only if the request has come down from block/bio path, not for
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direct access requests which only specify rq->buffer without a valid rq->bio)
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3.2.5 Generic request command tagging
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3.2.5.1 Tag helpers
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Block now offers some simple generic functionality to help support command
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queueing (typically known as tagged command queueing), ie manage more than
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one outstanding command on a queue at any given time.
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	blk_queue_init_tags(struct request_queue *q, int depth)
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	Initialize internal command tagging structures for a maximum
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	depth of 'depth'.
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	blk_queue_free_tags((struct request_queue *q)
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	Teardown tag info associated with the queue. This will be done
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	automatically by block if blk_queue_cleanup() is called on a queue
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	that is using tagging.
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The above are initialization and exit management, the main helpers during
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normal operations are:
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	blk_queue_start_tag(struct request_queue *q, struct request *rq)
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	Start tagged operation for this request. A free tag number between
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	0 and 'depth' is assigned to the request (rq->tag holds this number),
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	and 'rq' is added to the internal tag management. If the maximum depth
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	for this queue is already achieved (or if the tag wasn't started for
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	some other reason), 1 is returned. Otherwise 0 is returned.
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	blk_queue_end_tag(struct request_queue *q, struct request *rq)
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	End tagged operation on this request. 'rq' is removed from the internal
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	book keeping structures.
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To minimize struct request and queue overhead, the tag helpers utilize some
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of the same request members that are used for normal request queue management.
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This means that a request cannot both be an active tag and be on the queue
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list at the same time. blk_queue_start_tag() will remove the request, but
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the driver must remember to call blk_queue_end_tag() before signalling
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completion of the request to the block layer. This means ending tag
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operations before calling end_that_request_last()! For an example of a user
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of these helpers, see the IDE tagged command queueing support.
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3.2.5.2 Tag info
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Some block functions exist to query current tag status or to go from a
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tag number to the associated request. These are, in no particular order:
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	blk_queue_tagged(q)
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	Returns 1 if the queue 'q' is using tagging, 0 if not.
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	blk_queue_tag_request(q, tag)
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	Returns a pointer to the request associated with tag 'tag'.
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	blk_queue_tag_depth(q)
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	Return current queue depth.
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	blk_queue_tag_queue(q)
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	Returns 1 if the queue can accept a new queued command, 0 if we are
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	at the maximum depth already.
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	blk_queue_rq_tagged(rq)
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	Returns 1 if the request 'rq' is tagged.
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3.2.5.2 Internal structure
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Internally, block manages tags in the blk_queue_tag structure:
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	struct blk_queue_tag {
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		struct request **tag_index;	/* array or pointers to rq */
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		unsigned long *tag_map;		/* bitmap of free tags */
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		struct list_head busy_list;	/* fifo list of busy tags */
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		int busy;			/* queue depth */
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		int max_depth;			/* max queue depth */
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	};
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Most of the above is simple and straight forward, however busy_list may need
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a bit of explaining. Normally we don't care too much about request ordering,
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but in the event of any barrier requests in the tag queue we need to ensure
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that requests are restarted in the order they were queue.
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3.3 I/O Submission
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The routine submit_bio() is used to submit a single io. Higher level i/o
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			@ -3,7 +3,7 @@
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# Makefile for the kernel block layer
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#
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obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-tag.o blk-sysfs.o \
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obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
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			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
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			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
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			blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
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			@ -1658,9 +1658,6 @@ void blk_requeue_request(struct request_queue *q, struct request *rq)
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	trace_block_rq_requeue(q, rq);
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	rq_qos_requeue(q, rq);
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	if (rq->rq_flags & RQF_QUEUED)
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		blk_queue_end_tag(q, rq);
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	BUG_ON(blk_queued_rq(rq));
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	elv_requeue_request(q, rq);
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			@ -3174,9 +3171,6 @@ void blk_finish_request(struct request *req, blk_status_t error)
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	if (req->rq_flags & RQF_STATS)
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		blk_stat_add(req, now);
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	if (req->rq_flags & RQF_QUEUED)
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		blk_queue_end_tag(q, req);
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	BUG_ON(blk_queued_rq(req));
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	if (unlikely(laptop_mode) && !blk_rq_is_passthrough(req))
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			@ -112,7 +112,6 @@ static int queue_pm_only_show(void *data, struct seq_file *m)
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#define QUEUE_FLAG_NAME(name) [QUEUE_FLAG_##name] = #name
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static const char *const blk_queue_flag_name[] = {
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	QUEUE_FLAG_NAME(QUEUED),
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	QUEUE_FLAG_NAME(STOPPED),
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	QUEUE_FLAG_NAME(DYING),
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	QUEUE_FLAG_NAME(BYPASS),
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			@ -318,7 +317,6 @@ static const char *const cmd_flag_name[] = {
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static const char *const rqf_name[] = {
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	RQF_NAME(SORTED),
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	RQF_NAME(STARTED),
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	RQF_NAME(QUEUED),
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	RQF_NAME(SOFTBARRIER),
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	RQF_NAME(FLUSH_SEQ),
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	RQF_NAME(MIXED_MERGE),
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						 | 
				
			
			
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			@ -530,10 +530,8 @@ u32 blk_mq_unique_tag(struct request *rq)
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	struct blk_mq_hw_ctx *hctx;
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	int hwq = 0;
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	if (q->mq_ops) {
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		hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
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		hwq = hctx->queue_num;
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	}
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	hctx = blk_mq_map_queue(q, rq->mq_ctx->cpu);
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	hwq = hctx->queue_num;
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	return (hwq << BLK_MQ_UNIQUE_TAG_BITS) |
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		(rq->tag & BLK_MQ_UNIQUE_TAG_MASK);
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			@ -849,9 +849,6 @@ static void __blk_release_queue(struct work_struct *work)
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	blk_exit_rl(q, &q->root_rl);
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	if (q->queue_tags)
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		__blk_queue_free_tags(q);
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	blk_queue_free_zone_bitmaps(q);
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	if (!q->mq_ops) {
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						 | 
				
			
			
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		|||
							
								
								
									
										378
									
								
								block/blk-tag.c
									
									
									
									
									
								
							
							
						
						
									
										378
									
								
								block/blk-tag.c
									
									
									
									
									
								
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			@ -1,378 +0,0 @@
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// SPDX-License-Identifier: GPL-2.0
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/*
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 * Functions related to tagged command queuing
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 */
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/slab.h>
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#include "blk.h"
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/**
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 * blk_queue_find_tag - find a request by its tag and queue
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 * @q:	 The request queue for the device
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 * @tag: The tag of the request
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 *
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 * Notes:
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 *    Should be used when a device returns a tag and you want to match
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 *    it with a request.
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 *
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 *    no locks need be held.
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 **/
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struct request *blk_queue_find_tag(struct request_queue *q, int tag)
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{
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	return blk_map_queue_find_tag(q->queue_tags, tag);
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}
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EXPORT_SYMBOL(blk_queue_find_tag);
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/**
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 * blk_free_tags - release a given set of tag maintenance info
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 * @bqt:	the tag map to free
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 *
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 * Drop the reference count on @bqt and frees it when the last reference
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 * is dropped.
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 */
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void blk_free_tags(struct blk_queue_tag *bqt)
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{
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	if (atomic_dec_and_test(&bqt->refcnt)) {
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		BUG_ON(find_first_bit(bqt->tag_map, bqt->max_depth) <
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							bqt->max_depth);
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		kfree(bqt->tag_index);
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		bqt->tag_index = NULL;
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		kfree(bqt->tag_map);
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		bqt->tag_map = NULL;
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		kfree(bqt);
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	}
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}
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EXPORT_SYMBOL(blk_free_tags);
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/**
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 * __blk_queue_free_tags - release tag maintenance info
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 * @q:  the request queue for the device
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 *
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 *  Notes:
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 *    blk_cleanup_queue() will take care of calling this function, if tagging
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 *    has been used. So there's no need to call this directly.
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 **/
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void __blk_queue_free_tags(struct request_queue *q)
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{
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	struct blk_queue_tag *bqt = q->queue_tags;
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	if (!bqt)
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		return;
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	blk_free_tags(bqt);
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	q->queue_tags = NULL;
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	queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);
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}
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/**
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 * blk_queue_free_tags - release tag maintenance info
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 * @q:  the request queue for the device
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 *
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 *  Notes:
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 *	This is used to disable tagged queuing to a device, yet leave
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 *	queue in function.
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 **/
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void blk_queue_free_tags(struct request_queue *q)
 | 
			
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{
 | 
			
		||||
	queue_flag_clear_unlocked(QUEUE_FLAG_QUEUED, q);
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}
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EXPORT_SYMBOL(blk_queue_free_tags);
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		||||
static int
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init_tag_map(struct request_queue *q, struct blk_queue_tag *tags, int depth)
 | 
			
		||||
{
 | 
			
		||||
	struct request **tag_index;
 | 
			
		||||
	unsigned long *tag_map;
 | 
			
		||||
	int nr_ulongs;
 | 
			
		||||
 | 
			
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	if (q && depth > q->nr_requests * 2) {
 | 
			
		||||
		depth = q->nr_requests * 2;
 | 
			
		||||
		printk(KERN_ERR "%s: adjusted depth to %d\n",
 | 
			
		||||
		       __func__, depth);
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	tag_index = kcalloc(depth, sizeof(struct request *), GFP_ATOMIC);
 | 
			
		||||
	if (!tag_index)
 | 
			
		||||
		goto fail;
 | 
			
		||||
 | 
			
		||||
	nr_ulongs = ALIGN(depth, BITS_PER_LONG) / BITS_PER_LONG;
 | 
			
		||||
	tag_map = kcalloc(nr_ulongs, sizeof(unsigned long), GFP_ATOMIC);
 | 
			
		||||
	if (!tag_map)
 | 
			
		||||
		goto fail;
 | 
			
		||||
 | 
			
		||||
	tags->real_max_depth = depth;
 | 
			
		||||
	tags->max_depth = depth;
 | 
			
		||||
	tags->tag_index = tag_index;
 | 
			
		||||
	tags->tag_map = tag_map;
 | 
			
		||||
 | 
			
		||||
	return 0;
 | 
			
		||||
fail:
 | 
			
		||||
	kfree(tag_index);
 | 
			
		||||
	return -ENOMEM;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
static struct blk_queue_tag *__blk_queue_init_tags(struct request_queue *q,
 | 
			
		||||
						int depth, int alloc_policy)
 | 
			
		||||
{
 | 
			
		||||
	struct blk_queue_tag *tags;
 | 
			
		||||
 | 
			
		||||
	tags = kmalloc(sizeof(struct blk_queue_tag), GFP_ATOMIC);
 | 
			
		||||
	if (!tags)
 | 
			
		||||
		goto fail;
 | 
			
		||||
 | 
			
		||||
	if (init_tag_map(q, tags, depth))
 | 
			
		||||
		goto fail;
 | 
			
		||||
 | 
			
		||||
	atomic_set(&tags->refcnt, 1);
 | 
			
		||||
	tags->alloc_policy = alloc_policy;
 | 
			
		||||
	tags->next_tag = 0;
 | 
			
		||||
	return tags;
 | 
			
		||||
fail:
 | 
			
		||||
	kfree(tags);
 | 
			
		||||
	return NULL;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * blk_init_tags - initialize the tag info for an external tag map
 | 
			
		||||
 * @depth:	the maximum queue depth supported
 | 
			
		||||
 * @alloc_policy: tag allocation policy
 | 
			
		||||
 **/
 | 
			
		||||
struct blk_queue_tag *blk_init_tags(int depth, int alloc_policy)
 | 
			
		||||
{
 | 
			
		||||
	return __blk_queue_init_tags(NULL, depth, alloc_policy);
 | 
			
		||||
}
 | 
			
		||||
EXPORT_SYMBOL(blk_init_tags);
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * blk_queue_init_tags - initialize the queue tag info
 | 
			
		||||
 * @q:  the request queue for the device
 | 
			
		||||
 * @depth:  the maximum queue depth supported
 | 
			
		||||
 * @tags: the tag to use
 | 
			
		||||
 * @alloc_policy: tag allocation policy
 | 
			
		||||
 *
 | 
			
		||||
 * Queue lock must be held here if the function is called to resize an
 | 
			
		||||
 * existing map.
 | 
			
		||||
 **/
 | 
			
		||||
int blk_queue_init_tags(struct request_queue *q, int depth,
 | 
			
		||||
			struct blk_queue_tag *tags, int alloc_policy)
 | 
			
		||||
{
 | 
			
		||||
	int rc;
 | 
			
		||||
 | 
			
		||||
	BUG_ON(tags && q->queue_tags && tags != q->queue_tags);
 | 
			
		||||
 | 
			
		||||
	if (!tags && !q->queue_tags) {
 | 
			
		||||
		tags = __blk_queue_init_tags(q, depth, alloc_policy);
 | 
			
		||||
 | 
			
		||||
		if (!tags)
 | 
			
		||||
			return -ENOMEM;
 | 
			
		||||
 | 
			
		||||
	} else if (q->queue_tags) {
 | 
			
		||||
		rc = blk_queue_resize_tags(q, depth);
 | 
			
		||||
		if (rc)
 | 
			
		||||
			return rc;
 | 
			
		||||
		queue_flag_set(QUEUE_FLAG_QUEUED, q);
 | 
			
		||||
		return 0;
 | 
			
		||||
	} else
 | 
			
		||||
		atomic_inc(&tags->refcnt);
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * assign it, all done
 | 
			
		||||
	 */
 | 
			
		||||
	q->queue_tags = tags;
 | 
			
		||||
	queue_flag_set_unlocked(QUEUE_FLAG_QUEUED, q);
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
EXPORT_SYMBOL(blk_queue_init_tags);
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * blk_queue_resize_tags - change the queueing depth
 | 
			
		||||
 * @q:  the request queue for the device
 | 
			
		||||
 * @new_depth: the new max command queueing depth
 | 
			
		||||
 *
 | 
			
		||||
 *  Notes:
 | 
			
		||||
 *    Must be called with the queue lock held.
 | 
			
		||||
 **/
 | 
			
		||||
int blk_queue_resize_tags(struct request_queue *q, int new_depth)
 | 
			
		||||
{
 | 
			
		||||
	struct blk_queue_tag *bqt = q->queue_tags;
 | 
			
		||||
	struct request **tag_index;
 | 
			
		||||
	unsigned long *tag_map;
 | 
			
		||||
	int max_depth, nr_ulongs;
 | 
			
		||||
 | 
			
		||||
	if (!bqt)
 | 
			
		||||
		return -ENXIO;
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * if we already have large enough real_max_depth.  just
 | 
			
		||||
	 * adjust max_depth.  *NOTE* as requests with tag value
 | 
			
		||||
	 * between new_depth and real_max_depth can be in-flight, tag
 | 
			
		||||
	 * map can not be shrunk blindly here.
 | 
			
		||||
	 */
 | 
			
		||||
	if (new_depth <= bqt->real_max_depth) {
 | 
			
		||||
		bqt->max_depth = new_depth;
 | 
			
		||||
		return 0;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * Currently cannot replace a shared tag map with a new
 | 
			
		||||
	 * one, so error out if this is the case
 | 
			
		||||
	 */
 | 
			
		||||
	if (atomic_read(&bqt->refcnt) != 1)
 | 
			
		||||
		return -EBUSY;
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * save the old state info, so we can copy it back
 | 
			
		||||
	 */
 | 
			
		||||
	tag_index = bqt->tag_index;
 | 
			
		||||
	tag_map = bqt->tag_map;
 | 
			
		||||
	max_depth = bqt->real_max_depth;
 | 
			
		||||
 | 
			
		||||
	if (init_tag_map(q, bqt, new_depth))
 | 
			
		||||
		return -ENOMEM;
 | 
			
		||||
 | 
			
		||||
	memcpy(bqt->tag_index, tag_index, max_depth * sizeof(struct request *));
 | 
			
		||||
	nr_ulongs = ALIGN(max_depth, BITS_PER_LONG) / BITS_PER_LONG;
 | 
			
		||||
	memcpy(bqt->tag_map, tag_map, nr_ulongs * sizeof(unsigned long));
 | 
			
		||||
 | 
			
		||||
	kfree(tag_index);
 | 
			
		||||
	kfree(tag_map);
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
EXPORT_SYMBOL(blk_queue_resize_tags);
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * blk_queue_end_tag - end tag operations for a request
 | 
			
		||||
 * @q:  the request queue for the device
 | 
			
		||||
 * @rq: the request that has completed
 | 
			
		||||
 *
 | 
			
		||||
 *  Description:
 | 
			
		||||
 *    Typically called when end_that_request_first() returns %0, meaning
 | 
			
		||||
 *    all transfers have been done for a request. It's important to call
 | 
			
		||||
 *    this function before end_that_request_last(), as that will put the
 | 
			
		||||
 *    request back on the free list thus corrupting the internal tag list.
 | 
			
		||||
 **/
 | 
			
		||||
void blk_queue_end_tag(struct request_queue *q, struct request *rq)
 | 
			
		||||
{
 | 
			
		||||
	struct blk_queue_tag *bqt = q->queue_tags;
 | 
			
		||||
	unsigned tag = rq->tag; /* negative tags invalid */
 | 
			
		||||
 | 
			
		||||
	lockdep_assert_held(q->queue_lock);
 | 
			
		||||
 | 
			
		||||
	BUG_ON(tag >= bqt->real_max_depth);
 | 
			
		||||
 | 
			
		||||
	list_del_init(&rq->queuelist);
 | 
			
		||||
	rq->rq_flags &= ~RQF_QUEUED;
 | 
			
		||||
	rq->tag = -1;
 | 
			
		||||
	rq->internal_tag = -1;
 | 
			
		||||
 | 
			
		||||
	if (unlikely(bqt->tag_index[tag] == NULL))
 | 
			
		||||
		printk(KERN_ERR "%s: tag %d is missing\n",
 | 
			
		||||
		       __func__, tag);
 | 
			
		||||
 | 
			
		||||
	bqt->tag_index[tag] = NULL;
 | 
			
		||||
 | 
			
		||||
	if (unlikely(!test_bit(tag, bqt->tag_map))) {
 | 
			
		||||
		printk(KERN_ERR "%s: attempt to clear non-busy tag (%d)\n",
 | 
			
		||||
		       __func__, tag);
 | 
			
		||||
		return;
 | 
			
		||||
	}
 | 
			
		||||
	/*
 | 
			
		||||
	 * The tag_map bit acts as a lock for tag_index[bit], so we need
 | 
			
		||||
	 * unlock memory barrier semantics.
 | 
			
		||||
	 */
 | 
			
		||||
	clear_bit_unlock(tag, bqt->tag_map);
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * blk_queue_start_tag - find a free tag and assign it
 | 
			
		||||
 * @q:  the request queue for the device
 | 
			
		||||
 * @rq:  the block request that needs tagging
 | 
			
		||||
 *
 | 
			
		||||
 *  Description:
 | 
			
		||||
 *    This can either be used as a stand-alone helper, or possibly be
 | 
			
		||||
 *    assigned as the queue &prep_rq_fn (in which case &struct request
 | 
			
		||||
 *    automagically gets a tag assigned). Note that this function
 | 
			
		||||
 *    assumes that any type of request can be queued! if this is not
 | 
			
		||||
 *    true for your device, you must check the request type before
 | 
			
		||||
 *    calling this function.  The request will also be removed from
 | 
			
		||||
 *    the request queue, so it's the drivers responsibility to readd
 | 
			
		||||
 *    it if it should need to be restarted for some reason.
 | 
			
		||||
 **/
 | 
			
		||||
int blk_queue_start_tag(struct request_queue *q, struct request *rq)
 | 
			
		||||
{
 | 
			
		||||
	struct blk_queue_tag *bqt = q->queue_tags;
 | 
			
		||||
	unsigned max_depth;
 | 
			
		||||
	int tag;
 | 
			
		||||
 | 
			
		||||
	lockdep_assert_held(q->queue_lock);
 | 
			
		||||
 | 
			
		||||
	if (unlikely((rq->rq_flags & RQF_QUEUED))) {
 | 
			
		||||
		printk(KERN_ERR
 | 
			
		||||
		       "%s: request %p for device [%s] already tagged %d",
 | 
			
		||||
		       __func__, rq,
 | 
			
		||||
		       rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->tag);
 | 
			
		||||
		BUG();
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	/*
 | 
			
		||||
	 * Protect against shared tag maps, as we may not have exclusive
 | 
			
		||||
	 * access to the tag map.
 | 
			
		||||
	 *
 | 
			
		||||
	 * We reserve a few tags just for sync IO, since we don't want
 | 
			
		||||
	 * to starve sync IO on behalf of flooding async IO.
 | 
			
		||||
	 */
 | 
			
		||||
	max_depth = bqt->max_depth;
 | 
			
		||||
	if (!rq_is_sync(rq) && max_depth > 1) {
 | 
			
		||||
		switch (max_depth) {
 | 
			
		||||
		case 2:
 | 
			
		||||
			max_depth = 1;
 | 
			
		||||
			break;
 | 
			
		||||
		case 3:
 | 
			
		||||
			max_depth = 2;
 | 
			
		||||
			break;
 | 
			
		||||
		default:
 | 
			
		||||
			max_depth -= 2;
 | 
			
		||||
		}
 | 
			
		||||
		if (q->in_flight[BLK_RW_ASYNC] > max_depth)
 | 
			
		||||
			return 1;
 | 
			
		||||
	}
 | 
			
		||||
 | 
			
		||||
	do {
 | 
			
		||||
		if (bqt->alloc_policy == BLK_TAG_ALLOC_FIFO) {
 | 
			
		||||
			tag = find_first_zero_bit(bqt->tag_map, max_depth);
 | 
			
		||||
			if (tag >= max_depth)
 | 
			
		||||
				return 1;
 | 
			
		||||
		} else {
 | 
			
		||||
			int start = bqt->next_tag;
 | 
			
		||||
			int size = min_t(int, bqt->max_depth, max_depth + start);
 | 
			
		||||
			tag = find_next_zero_bit(bqt->tag_map, size, start);
 | 
			
		||||
			if (tag >= size && start + size > bqt->max_depth) {
 | 
			
		||||
				size = start + size - bqt->max_depth;
 | 
			
		||||
				tag = find_first_zero_bit(bqt->tag_map, size);
 | 
			
		||||
			}
 | 
			
		||||
			if (tag >= size)
 | 
			
		||||
				return 1;
 | 
			
		||||
		}
 | 
			
		||||
 | 
			
		||||
	} while (test_and_set_bit_lock(tag, bqt->tag_map));
 | 
			
		||||
	/*
 | 
			
		||||
	 * We need lock ordering semantics given by test_and_set_bit_lock.
 | 
			
		||||
	 * See blk_queue_end_tag for details.
 | 
			
		||||
	 */
 | 
			
		||||
 | 
			
		||||
	bqt->next_tag = (tag + 1) % bqt->max_depth;
 | 
			
		||||
	rq->rq_flags |= RQF_QUEUED;
 | 
			
		||||
	rq->tag = tag;
 | 
			
		||||
	bqt->tag_index[tag] = rq;
 | 
			
		||||
	blk_start_request(rq);
 | 
			
		||||
	return 0;
 | 
			
		||||
}
 | 
			
		||||
EXPORT_SYMBOL(blk_queue_start_tag);
 | 
			
		||||
| 
						 | 
				
			
			@ -85,8 +85,6 @@ typedef __u32 __bitwise req_flags_t;
 | 
			
		|||
#define RQF_SORTED		((__force req_flags_t)(1 << 0))
 | 
			
		||||
/* drive already may have started this one */
 | 
			
		||||
#define RQF_STARTED		((__force req_flags_t)(1 << 1))
 | 
			
		||||
/* uses tagged queueing */
 | 
			
		||||
#define RQF_QUEUED		((__force req_flags_t)(1 << 2))
 | 
			
		||||
/* may not be passed by ioscheduler */
 | 
			
		||||
#define RQF_SOFTBARRIER		((__force req_flags_t)(1 << 3))
 | 
			
		||||
/* request for flush sequence */
 | 
			
		||||
| 
						 | 
				
			
			@ -336,15 +334,6 @@ enum blk_queue_state {
 | 
			
		|||
	Queue_up,
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
struct blk_queue_tag {
 | 
			
		||||
	struct request **tag_index;	/* map of busy tags */
 | 
			
		||||
	unsigned long *tag_map;		/* bit map of free/busy tags */
 | 
			
		||||
	int max_depth;			/* what we will send to device */
 | 
			
		||||
	int real_max_depth;		/* what the array can hold */
 | 
			
		||||
	atomic_t refcnt;		/* map can be shared */
 | 
			
		||||
	int alloc_policy;		/* tag allocation policy */
 | 
			
		||||
	int next_tag;			/* next tag */
 | 
			
		||||
};
 | 
			
		||||
#define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
 | 
			
		||||
#define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -568,8 +557,6 @@ struct request_queue {
 | 
			
		|||
	unsigned int		dma_pad_mask;
 | 
			
		||||
	unsigned int		dma_alignment;
 | 
			
		||||
 | 
			
		||||
	struct blk_queue_tag	*queue_tags;
 | 
			
		||||
 | 
			
		||||
	unsigned int		nr_sorted;
 | 
			
		||||
	unsigned int		in_flight[2];
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -680,7 +667,6 @@ struct request_queue {
 | 
			
		|||
	u64			write_hints[BLK_MAX_WRITE_HINTS];
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
#define QUEUE_FLAG_QUEUED	0	/* uses generic tag queueing */
 | 
			
		||||
#define QUEUE_FLAG_STOPPED	1	/* queue is stopped */
 | 
			
		||||
#define QUEUE_FLAG_DYING	2	/* queue being torn down */
 | 
			
		||||
#define QUEUE_FLAG_BYPASS	3	/* act as dumb FIFO queue */
 | 
			
		||||
| 
						 | 
				
			
			@ -724,7 +710,6 @@ void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
 | 
			
		|||
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
 | 
			
		||||
bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
 | 
			
		||||
 | 
			
		||||
#define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 | 
			
		||||
#define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 | 
			
		||||
#define blk_queue_dying(q)	test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags)
 | 
			
		||||
#define blk_queue_dead(q)	test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
 | 
			
		||||
| 
						 | 
				
			
			@ -1359,26 +1344,6 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk)
 | 
			
		|||
		 !list_empty(&plug->cb_list));
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/*
 | 
			
		||||
 * tag stuff
 | 
			
		||||
 */
 | 
			
		||||
extern int blk_queue_start_tag(struct request_queue *, struct request *);
 | 
			
		||||
extern struct request *blk_queue_find_tag(struct request_queue *, int);
 | 
			
		||||
extern void blk_queue_end_tag(struct request_queue *, struct request *);
 | 
			
		||||
extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *, int);
 | 
			
		||||
extern void blk_queue_free_tags(struct request_queue *);
 | 
			
		||||
extern int blk_queue_resize_tags(struct request_queue *, int);
 | 
			
		||||
extern struct blk_queue_tag *blk_init_tags(int, int);
 | 
			
		||||
extern void blk_free_tags(struct blk_queue_tag *);
 | 
			
		||||
 | 
			
		||||
static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 | 
			
		||||
						int tag)
 | 
			
		||||
{
 | 
			
		||||
	if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
 | 
			
		||||
		return NULL;
 | 
			
		||||
	return bqt->tag_index[tag];
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 | 
			
		||||
extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 | 
			
		||||
		sector_t nr_sects, gfp_t gfp_mask, struct page *page);
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
		Loading…
	
		Reference in a new issue