From 03100aada96f0645bbcb89aea24c01f02d0ef1fa Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 19 Aug 2015 14:24:05 -0700 Subject: block: Replace SG_GAPS with new queue limits mask The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e427debc7008..a622f270f09e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -250,6 +250,7 @@ struct blk_queue_tag { struct queue_limits { unsigned long bounce_pfn; unsigned long seg_boundary_mask; + unsigned long virt_boundary_mask; unsigned int max_hw_sectors; unsigned int chunk_sectors; @@ -479,7 +480,6 @@ struct request_queue { #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ -#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ @@ -981,6 +981,7 @@ extern int blk_queue_dma_drain(struct request_queue *q, void *buf, unsigned int size); extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); +extern void blk_queue_virt_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); extern void blk_queue_dma_alignment(struct request_queue *, int); @@ -1149,6 +1150,11 @@ static inline unsigned long queue_segment_boundary(struct request_queue *q) return q->limits.seg_boundary_mask; } +static inline unsigned long queue_virt_boundary(struct request_queue *q) +{ + return q->limits.virt_boundary_mask; +} + static inline unsigned int queue_max_sectors(struct request_queue *q) { return q->limits.max_sectors; @@ -1349,6 +1355,19 @@ static inline void put_dev_sector(Sector p) page_cache_release(p.v); } +/* + * Check if adding a bio_vec after bprv with offset would create a gap in + * the SG list. Most drivers don't care about this, but some do. + */ +static inline bool bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + if (!queue_virt_boundary(q)) + return false; + return offset || + ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); +} + struct work_struct; int kblockd_schedule_work(struct work_struct *work); int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); -- cgit v1.2.3