From 03100aada96f0645bbcb89aea24c01f02d0ef1fa Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 19 Aug 2015 14:24:05 -0700 Subject: [PATCH] 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 --- block/bio.c | 3 +-- block/blk-merge.c | 23 +++++++---------------- block/blk-settings.c | 14 ++++++++++++++ drivers/block/nvme-core.c | 2 +- drivers/md/dm-table.c | 13 ------------- include/linux/bio.h | 9 --------- include/linux/blkdev.h | 21 ++++++++++++++++++++- 7 files changed, 43 insertions(+), 42 deletions(-) diff --git a/block/bio.c b/block/bio.c index 425d6d4..b1f198f 100644 --- a/block/bio.c +++ b/block/bio.c @@ -742,8 +742,7 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page * If the queue doesn't support SG gaps and adding this * offset would create a gap, disallow it. */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && - bvec_gap_to_prev(prev, offset)) + if (bvec_gap_to_prev(q, prev, offset)) return 0; } diff --git a/block/blk-merge.c b/block/blk-merge.c index 0027def..0e0d9fd 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -82,8 +82,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, * If the queue doesn't support SG gaps and adding this * offset would create a gap, disallow it. */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && - prev && bvec_gap_to_prev(&bvprv, bv.bv_offset)) + if (prev && bvec_gap_to_prev(q, &bvprv, bv.bv_offset)) goto split; if (prev && blk_queue_cluster(q)) { @@ -484,12 +483,12 @@ static bool req_no_special_merge(struct request *req) return !q->mq_ops && req->special; } -static int req_gap_to_prev(struct request *req, struct request *next) +static int req_gap_to_prev(struct request *req, struct bio *next) { struct bio *prev = req->biotail; - return bvec_gap_to_prev(&prev->bi_io_vec[prev->bi_vcnt - 1], - next->bio->bi_io_vec[0].bv_offset); + return bvec_gap_to_prev(req->q, &prev->bi_io_vec[prev->bi_vcnt - 1], + next->bi_io_vec[1].bv_offset); } static int ll_merge_requests_fn(struct request_queue *q, struct request *req, @@ -506,8 +505,7 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, if (req_no_special_merge(req) || req_no_special_merge(next)) return 0; - if (test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags) && - req_gap_to_prev(req, next)) + if (req_gap_to_prev(req, next->bio)) return 0; /* @@ -692,8 +690,6 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq, bool blk_rq_merge_ok(struct request *rq, struct bio *bio) { - struct request_queue *q = rq->q; - if (!rq_mergeable(rq) || !bio_mergeable(bio)) return false; @@ -718,13 +714,8 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) return false; /* Only check gaps if the bio carries data */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && bio_has_data(bio)) { - struct bio_vec *bprev; - - bprev = &rq->biotail->bi_io_vec[rq->biotail->bi_vcnt - 1]; - if (bvec_gap_to_prev(bprev, bio->bi_io_vec[0].bv_offset)) - return false; - } + if (bio_has_data(bio) && req_gap_to_prev(rq, bio)) + return false; return true; } diff --git a/block/blk-settings.c b/block/blk-settings.c index d27b4e2..f96c721 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -89,6 +89,7 @@ void blk_set_default_limits(struct queue_limits *lim) lim->max_segments = BLK_MAX_SEGMENTS; lim->max_integrity_segments = 0; lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK; + lim->virt_boundary_mask = 0; lim->max_segment_size = BLK_MAX_SEGMENT_SIZE; lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS; lim->chunk_sectors = 0; @@ -532,6 +533,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, t->seg_boundary_mask = min_not_zero(t->seg_boundary_mask, b->seg_boundary_mask); + t->virt_boundary_mask = min_not_zero(t->virt_boundary_mask, + b->virt_boundary_mask); t->max_segments = min_not_zero(t->max_segments, b->max_segments); t->max_integrity_segments = min_not_zero(t->max_integrity_segments, @@ -772,6 +775,17 @@ void blk_queue_segment_boundary(struct request_queue *q, unsigned long mask) EXPORT_SYMBOL(blk_queue_segment_boundary); /** + * blk_queue_virt_boundary - set boundary rules for bio merging + * @q: the request queue for the device + * @mask: the memory boundary mask + **/ +void blk_queue_virt_boundary(struct request_queue *q, unsigned long mask) +{ + q->limits.virt_boundary_mask = mask; +} +EXPORT_SYMBOL(blk_queue_virt_boundary); + +/** * blk_queue_dma_alignment - set dma length and memory alignment * @q: the request queue for the device * @mask: alignment mask diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index d844ec4..2f694d7 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -2067,7 +2067,6 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid) goto out_free_ns; queue_flag_set_unlocked(QUEUE_FLAG_NOMERGES, ns->queue); queue_flag_set_unlocked(QUEUE_FLAG_NONROT, ns->queue); - queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, ns->queue); ns->dev = dev; ns->queue->queuedata = ns; @@ -2087,6 +2086,7 @@ static void nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid) blk_queue_chunk_sectors(ns->queue, dev->stripe_size >> 9); if (dev->vwc & NVME_CTRL_VWC_PRESENT) blk_queue_flush(ns->queue, REQ_FLUSH | REQ_FUA); + blk_queue_virt_boundary(ns->queue, dev->page_size - 1); disk->major = nvme_major; disk->first_minor = 0; diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index afb4ad3..e76ed00 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1380,14 +1380,6 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev, return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags); } -static int queue_supports_sg_gaps(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) -{ - struct request_queue *q = bdev_get_queue(dev->bdev); - - return q && !test_bit(QUEUE_FLAG_SG_GAPS, &q->queue_flags); -} - static bool dm_table_all_devices_attribute(struct dm_table *t, iterate_devices_callout_fn func) { @@ -1508,11 +1500,6 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, else queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q); - if (dm_table_all_devices_attribute(t, queue_supports_sg_gaps)) - queue_flag_clear_unlocked(QUEUE_FLAG_SG_GAPS, q); - else - queue_flag_set_unlocked(QUEUE_FLAG_SG_GAPS, q); - dm_table_set_integrity(t); /* diff --git a/include/linux/bio.h b/include/linux/bio.h index ad72174..b9b6e04 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -187,15 +187,6 @@ static inline void *bio_data(struct bio *bio) __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q))) /* - * 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 bio_vec *bprv, unsigned int offset) -{ - return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1)); -} - -/* * drivers should _never_ use the all version - the bio may have been split * before it got to the driver and the driver won't own all of it */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e427deb..a622f27 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); -- 2.7.4