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				https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
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	Fix racy updates of shared blk_mq_bitmap_tags::wake_index and blk_mq_hw_ctx::wake_index fields. Cc: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
		
			
				
	
	
		
			89 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			89 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef INT_BLK_MQ_TAG_H
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#define INT_BLK_MQ_TAG_H
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#include "blk-mq.h"
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enum {
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	BT_WAIT_QUEUES	= 8,
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	BT_WAIT_BATCH	= 8,
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};
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struct bt_wait_state {
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	atomic_t wait_cnt;
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	wait_queue_head_t wait;
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} ____cacheline_aligned_in_smp;
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#define TAG_TO_INDEX(bt, tag)	((tag) >> (bt)->bits_per_word)
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#define TAG_TO_BIT(bt, tag)	((tag) & ((1 << (bt)->bits_per_word) - 1))
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struct blk_mq_bitmap_tags {
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	unsigned int depth;
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	unsigned int wake_cnt;
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	unsigned int bits_per_word;
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	unsigned int map_nr;
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	struct blk_align_bitmap *map;
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	atomic_t wake_index;
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	struct bt_wait_state *bs;
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};
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/*
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 * Tag address space map.
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 */
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struct blk_mq_tags {
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	unsigned int nr_tags;
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	unsigned int nr_reserved_tags;
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	atomic_t active_queues;
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	struct blk_mq_bitmap_tags bitmap_tags;
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	struct blk_mq_bitmap_tags breserved_tags;
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	struct request **rqs;
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	struct list_head page_list;
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};
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extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int reserved_tags, int node);
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extern void blk_mq_free_tags(struct blk_mq_tags *tags);
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extern unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data);
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extern void blk_mq_put_tag(struct blk_mq_hw_ctx *hctx, unsigned int tag, unsigned int *last_tag);
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extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);
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extern ssize_t blk_mq_tag_sysfs_show(struct blk_mq_tags *tags, char *page);
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extern void blk_mq_tag_init_last_tag(struct blk_mq_tags *tags, unsigned int *last_tag);
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extern int blk_mq_tag_update_depth(struct blk_mq_tags *tags, unsigned int depth);
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enum {
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	BLK_MQ_TAG_CACHE_MIN	= 1,
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	BLK_MQ_TAG_CACHE_MAX	= 64,
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};
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enum {
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	BLK_MQ_TAG_FAIL		= -1U,
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	BLK_MQ_TAG_MIN		= BLK_MQ_TAG_CACHE_MIN,
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	BLK_MQ_TAG_MAX		= BLK_MQ_TAG_FAIL - 1,
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};
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extern bool __blk_mq_tag_busy(struct blk_mq_hw_ctx *);
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extern void __blk_mq_tag_idle(struct blk_mq_hw_ctx *);
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static inline bool blk_mq_tag_busy(struct blk_mq_hw_ctx *hctx)
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{
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	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
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		return false;
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	return __blk_mq_tag_busy(hctx);
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}
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static inline void blk_mq_tag_idle(struct blk_mq_hw_ctx *hctx)
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{
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	if (!(hctx->flags & BLK_MQ_F_TAG_SHARED))
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		return;
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	__blk_mq_tag_idle(hctx);
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}
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#endif
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