From e2a60da74fc8215c68509a89e9a69c66363153db Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 18 Sep 2012 12:19:25 -0400 Subject: block: Clean up special command handling logic Remove special-casing of non-rw fs style requests (discard). The nomerge flags are consolidated in blk_types.h, and rq_mergeable() and bio_mergeable() have been modified to use them. bio_is_rw() is used in place of bio_has_data() a few places. This is done to to distinguish true reads and writes from other fs type requests that carry a payload (e.g. write same). Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 4a2ab7c85393..3a6fea7460f1 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -540,8 +540,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) #define blk_account_rq(rq) \ (((rq)->cmd_flags & REQ_STARTED) && \ - ((rq)->cmd_type == REQ_TYPE_FS || \ - ((rq)->cmd_flags & REQ_DISCARD))) + ((rq)->cmd_type == REQ_TYPE_FS)) #define blk_pm_request(rq) \ ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \ @@ -595,17 +594,16 @@ static inline void blk_clear_rl_full(struct request_list *rl, bool sync) rl->flags &= ~flag; } +static inline bool rq_mergeable(struct request *rq) +{ + if (rq->cmd_type != REQ_TYPE_FS) + return false; -/* - * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may - * it already be started by driver. - */ -#define RQ_NOMERGE_FLAGS \ - (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA | REQ_DISCARD) -#define rq_mergeable(rq) \ - (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \ - (((rq)->cmd_flags & REQ_DISCARD) || \ - (rq)->cmd_type == REQ_TYPE_FS)) + if (rq->cmd_flags & REQ_NOMERGE_FLAGS) + return false; + + return true; +} /* * q->prep_rq_fn return values -- cgit v1.2.3 From f31dc1cd490539e2b62a126bc4dc2495b165d772 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 18 Sep 2012 12:19:26 -0400 Subject: block: Consolidate command flag and queue limit checks for merges - blk_check_merge_flags() verifies that cmd_flags / bi_rw are compatible. This function is called for both req-req and req-bio merging. - blk_rq_get_max_sectors() and blk_queue_get_max_sectors() can be used to query the maximum sector count for a given request or queue. The calls will return the right value from the queue limits given the type of command (RW, discard, write same, etc.) Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3a6fea7460f1..90f7abe8f183 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -605,6 +605,18 @@ static inline bool rq_mergeable(struct request *rq) return true; } +static inline bool blk_check_merge_flags(unsigned int flags1, + unsigned int flags2) +{ + if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD)) + return false; + + if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) + return false; + + return true; +} + /* * q->prep_rq_fn return values */ @@ -800,6 +812,25 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq) return blk_rq_cur_bytes(rq) >> 9; } +static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, + unsigned int cmd_flags) +{ + if (unlikely(cmd_flags & REQ_DISCARD)) + return q->limits.max_discard_sectors; + + return q->limits.max_sectors; +} + +static inline unsigned int blk_rq_get_max_sectors(struct request *rq) +{ + struct request_queue *q = rq->q; + + if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC)) + return q->limits.max_hw_sectors; + + return blk_queue_get_max_sectors(q, rq->cmd_flags); +} + /* * Request issue related functions. */ -- cgit v1.2.3 From 4363ac7c13a9a4b763c6e8d9fdbfc2468f3b8ca4 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 18 Sep 2012 12:19:27 -0400 Subject: block: Implement support for WRITE SAME The WRITE SAME command supported on some SCSI devices allows the same block to be efficiently replicated throughout a block range. Only a single logical block is transferred from the host and the storage device writes the same data to all blocks described by the I/O. This patch implements support for WRITE SAME in the block layer. The blkdev_issue_write_same() function can be used by filesystems and block drivers to replicate a buffer across a block range. This can be used to efficiently initialize software RAID devices, etc. Signed-off-by: Martin K. Petersen Acked-by: Mike Snitzer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 90f7abe8f183..1756001210d2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -270,6 +270,7 @@ struct queue_limits { unsigned int io_min; unsigned int io_opt; unsigned int max_discard_sectors; + unsigned int max_write_same_sectors; unsigned int discard_granularity; unsigned int discard_alignment; @@ -614,9 +615,20 @@ static inline bool blk_check_merge_flags(unsigned int flags1, if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE)) return false; + if ((flags1 & REQ_WRITE_SAME) != (flags2 & REQ_WRITE_SAME)) + return false; + return true; } +static inline bool blk_write_same_mergeable(struct bio *a, struct bio *b) +{ + if (bio_data(a) == bio_data(b)) + return true; + + return false; +} + /* * q->prep_rq_fn return values */ @@ -818,6 +830,9 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, if (unlikely(cmd_flags & REQ_DISCARD)) return q->limits.max_discard_sectors; + if (unlikely(cmd_flags & REQ_WRITE_SAME)) + return q->limits.max_write_same_sectors; + return q->limits.max_sectors; } @@ -886,6 +901,8 @@ extern void blk_queue_max_segments(struct request_queue *, unsigned short); extern void blk_queue_max_segment_size(struct request_queue *, unsigned int); extern void blk_queue_max_discard_sectors(struct request_queue *q, unsigned int max_discard_sectors); +extern void blk_queue_max_write_same_sectors(struct request_queue *q, + unsigned int max_write_same_sectors); extern void blk_queue_logical_block_size(struct request_queue *, unsigned short); extern void blk_queue_physical_block_size(struct request_queue *, unsigned int); extern void blk_queue_alignment_offset(struct request_queue *q, @@ -1016,6 +1033,8 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *); extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); +extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, + sector_t nr_sects, gfp_t gfp_mask, struct page *page); extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask); static inline int sb_issue_discard(struct super_block *sb, sector_t block, @@ -1193,6 +1212,16 @@ static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev) return queue_discard_zeroes_data(bdev_get_queue(bdev)); } +static inline unsigned int bdev_write_same(struct block_device *bdev) +{ + struct request_queue *q = bdev_get_queue(bdev); + + if (q) + return q->limits.max_write_same_sectors; + + return 0; +} + static inline int queue_dma_alignment(struct request_queue *q) { return q ? q->dma_alignment : 511; -- cgit v1.2.3