From 13f05c8d8e98bbdce89158bfdb2e380940695a88 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 10 Sep 2010 20:50:10 +0200 Subject: block/scsi: Provide a limit on the number of integrity segments Some controllers have a hardware limit on the number of protection information scatter-gather list segments they can handle. Introduce a max_integrity_segments limit in the block layer and provide a new scsi_host_template setting that allows HBA drivers to provide a value suitable for the hardware. Add support for honoring the integrity segment limit when merging both bios and requests. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- block/blk-integrity.c | 93 ++++++++++++++++++++++++++++++++++++----------- block/blk-merge.c | 23 +++++++----- block/blk-settings.c | 3 ++ block/blk-sysfs.c | 11 ++++++ block/blk.h | 8 ---- drivers/scsi/hosts.c | 1 + drivers/scsi/scsi_lib.c | 26 +++++++++---- drivers/scsi/scsi_sysfs.c | 2 + include/linux/bio.h | 4 ++ include/linux/blkdev.h | 33 +++++++++++++++-- include/scsi/scsi.h | 6 +++ include/scsi/scsi_host.h | 7 ++++ 12 files changed, 167 insertions(+), 50 deletions(-) diff --git a/block/blk-integrity.c b/block/blk-integrity.c index edce1ef7933d..885cbb59967e 100644 --- a/block/blk-integrity.c +++ b/block/blk-integrity.c @@ -32,24 +32,37 @@ static struct kmem_cache *integrity_cachep; /** * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements - * @rq: request with integrity metadata attached + * @q: request queue + * @bio: bio with integrity metadata attached * * Description: Returns the number of elements required in a - * scatterlist corresponding to the integrity metadata in a request. + * scatterlist corresponding to the integrity metadata in a bio. */ -int blk_rq_count_integrity_sg(struct request *rq) +int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio) { - struct bio_vec *iv, *ivprv; - struct req_iterator iter; - unsigned int segments; + struct bio_vec *iv, *ivprv = NULL; + unsigned int segments = 0; + unsigned int seg_size = 0; + unsigned int i = 0; - ivprv = NULL; - segments = 0; + bio_for_each_integrity_vec(iv, bio, i) { - rq_for_each_integrity_segment(iv, rq, iter) { + if (ivprv) { + if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) + goto new_segment; + + if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv)) + goto new_segment; + + if (seg_size + iv->bv_len > queue_max_segment_size(q)) + goto new_segment; - if (!ivprv || !BIOVEC_PHYS_MERGEABLE(ivprv, iv)) + seg_size += iv->bv_len; + } else { +new_segment: segments++; + seg_size = iv->bv_len; + } ivprv = iv; } @@ -60,30 +73,34 @@ EXPORT_SYMBOL(blk_rq_count_integrity_sg); /** * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist - * @rq: request with integrity metadata attached + * @q: request queue + * @bio: bio with integrity metadata attached * @sglist: target scatterlist * * Description: Map the integrity vectors in request into a * scatterlist. The scatterlist must be big enough to hold all * elements. I.e. sized using blk_rq_count_integrity_sg(). */ -int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist) +int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio, + struct scatterlist *sglist) { - struct bio_vec *iv, *ivprv; - struct req_iterator iter; - struct scatterlist *sg; - unsigned int segments; + struct bio_vec *iv, *ivprv = NULL; + struct scatterlist *sg = NULL; + unsigned int segments = 0; + unsigned int i = 0; - ivprv = NULL; - sg = NULL; - segments = 0; - - rq_for_each_integrity_segment(iv, rq, iter) { + bio_for_each_integrity_vec(iv, bio, i) { if (ivprv) { if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) goto new_segment; + if (!BIOVEC_SEG_BOUNDARY(q, ivprv, iv)) + goto new_segment; + + if (sg->length + iv->bv_len > queue_max_segment_size(q)) + goto new_segment; + sg->length += iv->bv_len; } else { new_segment: @@ -162,6 +179,40 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2) } EXPORT_SYMBOL(blk_integrity_compare); +int blk_integrity_merge_rq(struct request_queue *q, struct request *req, + struct request *next) +{ + if (blk_integrity_rq(req) != blk_integrity_rq(next)) + return -1; + + if (req->nr_integrity_segments + next->nr_integrity_segments > + q->limits.max_integrity_segments) + return -1; + + return 0; +} +EXPORT_SYMBOL(blk_integrity_merge_rq); + +int blk_integrity_merge_bio(struct request_queue *q, struct request *req, + struct bio *bio) +{ + int nr_integrity_segs; + struct bio *next = bio->bi_next; + + bio->bi_next = NULL; + nr_integrity_segs = blk_rq_count_integrity_sg(q, bio); + bio->bi_next = next; + + if (req->nr_integrity_segments + nr_integrity_segs > + q->limits.max_integrity_segments) + return -1; + + req->nr_integrity_segments += nr_integrity_segs; + + return 0; +} +EXPORT_SYMBOL(blk_integrity_merge_bio); + struct integrity_sysfs_entry { struct attribute attr; ssize_t (*show)(struct blk_integrity *, char *); diff --git a/block/blk-merge.c b/block/blk-merge.c index 3b0cd4249671..6a725461654d 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -205,12 +205,11 @@ static inline int ll_new_hw_segment(struct request_queue *q, { int nr_phys_segs = bio_phys_segments(q, bio); - if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q)) { - req->cmd_flags |= REQ_NOMERGE; - if (req == q->last_merge) - q->last_merge = NULL; - return 0; - } + if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q)) + goto no_merge; + + if (bio_integrity(bio) && blk_integrity_merge_bio(q, req, bio)) + goto no_merge; /* * This will form the start of a new hw segment. Bump both @@ -218,6 +217,12 @@ static inline int ll_new_hw_segment(struct request_queue *q, */ req->nr_phys_segments += nr_phys_segs; return 1; + +no_merge: + req->cmd_flags |= REQ_NOMERGE; + if (req == q->last_merge) + q->last_merge = NULL; + return 0; } int ll_back_merge_fn(struct request_queue *q, struct request *req, @@ -301,6 +306,9 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req, if (total_phys_segments > queue_max_segments(q)) return 0; + if (blk_integrity_rq(req) && blk_integrity_merge_rq(q, req, next)) + return 0; + /* Merge is OK... */ req->nr_phys_segments = total_phys_segments; return 1; @@ -372,9 +380,6 @@ static int attempt_merge(struct request_queue *q, struct request *req, || next->special) return 0; - if (blk_integrity_rq(req) != blk_integrity_rq(next)) - return 0; - /* * If we are allowed to merge, then append bio list * from next to rq and release next. merge_requests_fn diff --git a/block/blk-settings.c b/block/blk-settings.c index 8d592b559bd3..f8f2ddf20613 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -111,6 +111,7 @@ EXPORT_SYMBOL_GPL(blk_queue_lld_busy); 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->max_segment_size = BLK_MAX_SEGMENT_SIZE; lim->max_sectors = BLK_DEF_MAX_SECTORS; @@ -509,6 +510,8 @@ int blk_stack_limits(struct queue_limits *t, struct queue_limits *b, b->seg_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, + b->max_integrity_segments); t->max_segment_size = min_not_zero(t->max_segment_size, b->max_segment_size); diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 001ab18078f5..b014f7739e98 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -112,6 +112,11 @@ static ssize_t queue_max_segments_show(struct request_queue *q, char *page) return queue_var_show(queue_max_segments(q), (page)); } +static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) +{ + return queue_var_show(q->limits.max_integrity_segments, (page)); +} + static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) { if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags)) @@ -288,6 +293,11 @@ static struct queue_sysfs_entry queue_max_segments_entry = { .show = queue_max_segments_show, }; +static struct queue_sysfs_entry queue_max_integrity_segments_entry = { + .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, + .show = queue_max_integrity_segments_show, +}; + static struct queue_sysfs_entry queue_max_segment_size_entry = { .attr = {.name = "max_segment_size", .mode = S_IRUGO }, .show = queue_max_segment_size_show, @@ -375,6 +385,7 @@ static struct attribute *default_attrs[] = { &queue_max_hw_sectors_entry.attr, &queue_max_sectors_entry.attr, &queue_max_segments_entry.attr, + &queue_max_integrity_segments_entry.attr, &queue_max_segment_size_entry.attr, &queue_iosched_entry.attr, &queue_hw_sector_size_entry.attr, diff --git a/block/blk.h b/block/blk.h index 6e7dc87141e4..6738831ba447 100644 --- a/block/blk.h +++ b/block/blk.h @@ -132,14 +132,6 @@ static inline int queue_congestion_off_threshold(struct request_queue *q) return q->nr_congestion_off; } -#if defined(CONFIG_BLK_DEV_INTEGRITY) - -#define rq_for_each_integrity_segment(bvl, _rq, _iter) \ - __rq_for_each_bio(_iter.bio, _rq) \ - bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i) - -#endif /* BLK_DEV_INTEGRITY */ - static inline int blk_cpu_to_group(int cpu) { #ifdef CONFIG_SCHED_MC diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 8a8f803439e1..10478153641b 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -376,6 +376,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) shost->this_id = sht->this_id; shost->can_queue = sht->can_queue; shost->sg_tablesize = sht->sg_tablesize; + shost->sg_prot_tablesize = sht->sg_prot_tablesize; shost->cmd_per_lun = sht->cmd_per_lun; shost->unchecked_isa_dma = sht->unchecked_isa_dma; shost->use_clustering = sht->use_clustering; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9ade720422c6..861c0b937ac9 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -968,11 +968,13 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, */ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { - int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); + struct request *rq = cmd->request; + + int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); if (error) goto err_exit; - if (blk_bidi_rq(cmd->request)) { + if (blk_bidi_rq(rq)) { struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( scsi_sdb_cache, GFP_ATOMIC); if (!bidi_sdb) { @@ -980,28 +982,28 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) goto err_exit; } - cmd->request->next_rq->special = bidi_sdb; - error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, - GFP_ATOMIC); + rq->next_rq->special = bidi_sdb; + error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC); if (error) goto err_exit; } - if (blk_integrity_rq(cmd->request)) { + if (blk_integrity_rq(rq)) { struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; int ivecs, count; BUG_ON(prot_sdb == NULL); - ivecs = blk_rq_count_integrity_sg(cmd->request); + ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { error = BLKPREP_DEFER; goto err_exit; } - count = blk_rq_map_integrity_sg(cmd->request, + count = blk_rq_map_integrity_sg(rq->q, rq->bio, prot_sdb->table.sgl); BUG_ON(unlikely(count > ivecs)); + BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); cmd->prot_sdb = prot_sdb; cmd->prot_sdb->table.nents = count; @@ -1625,6 +1627,14 @@ struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, SCSI_MAX_SG_CHAIN_SEGMENTS)); + if (scsi_host_prot_dma(shost)) { + shost->sg_prot_tablesize = + min_not_zero(shost->sg_prot_tablesize, + (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); + BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); + blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); + } + blk_queue_max_hw_sectors(q, shost->max_sectors); blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); blk_queue_segment_boundary(q, shost->dma_boundary); diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index c3f67373a4f8..20ad59dff730 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -251,6 +251,7 @@ shost_rd_attr(host_busy, "%hu\n"); shost_rd_attr(cmd_per_lun, "%hd\n"); shost_rd_attr(can_queue, "%hd\n"); shost_rd_attr(sg_tablesize, "%hu\n"); +shost_rd_attr(sg_prot_tablesize, "%hu\n"); shost_rd_attr(unchecked_isa_dma, "%d\n"); shost_rd_attr(prot_capabilities, "%u\n"); shost_rd_attr(prot_guard_type, "%hd\n"); @@ -262,6 +263,7 @@ static struct attribute *scsi_sysfs_shost_attrs[] = { &dev_attr_cmd_per_lun.attr, &dev_attr_can_queue.attr, &dev_attr_sg_tablesize.attr, + &dev_attr_sg_prot_tablesize.attr, &dev_attr_unchecked_isa_dma.attr, &dev_attr_proc_name.attr, &dev_attr_scan.attr, diff --git a/include/linux/bio.h b/include/linux/bio.h index 5274103434ad..2c3fd7421607 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -496,6 +496,10 @@ static inline struct bio *bio_list_get(struct bio_list *bl) #define bip_for_each_vec(bvl, bip, i) \ __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx) +#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \ + for_each_bio(_bio) \ + bip_for_each_vec(_bvl, _bio->bi_integrity, _iter) + #define bio_integrity(bio) (bio->bi_integrity != NULL) extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2c54906f678f..7e661106270a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -124,6 +124,9 @@ struct request { * physical address coalescing is performed. */ unsigned short nr_phys_segments; +#if defined(CONFIG_BLK_DEV_INTEGRITY) + unsigned short nr_integrity_segments; +#endif unsigned short ioprio; @@ -243,6 +246,7 @@ struct queue_limits { unsigned short logical_block_size; unsigned short max_segments; + unsigned short max_integrity_segments; unsigned char misaligned; unsigned char discard_misaligned; @@ -1213,8 +1217,13 @@ struct blk_integrity { extern int blk_integrity_register(struct gendisk *, struct blk_integrity *); extern void blk_integrity_unregister(struct gendisk *); extern int blk_integrity_compare(struct gendisk *, struct gendisk *); -extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *); -extern int blk_rq_count_integrity_sg(struct request *); +extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *, + struct scatterlist *); +extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *); +extern int blk_integrity_merge_rq(struct request_queue *, struct request *, + struct request *); +extern int blk_integrity_merge_bio(struct request_queue *, struct request *, + struct bio *); static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev) @@ -1235,16 +1244,32 @@ static inline int blk_integrity_rq(struct request *rq) return bio_integrity(rq->bio); } +static inline void blk_queue_max_integrity_segments(struct request_queue *q, + unsigned int segs) +{ + q->limits.max_integrity_segments = segs; +} + +static inline unsigned short +queue_max_integrity_segments(struct request_queue *q) +{ + return q->limits.max_integrity_segments; +} + #else /* CONFIG_BLK_DEV_INTEGRITY */ #define blk_integrity_rq(rq) (0) -#define blk_rq_count_integrity_sg(a) (0) -#define blk_rq_map_integrity_sg(a, b) (0) +#define blk_rq_count_integrity_sg(a, b) (0) +#define blk_rq_map_integrity_sg(a, b, c) (0) #define bdev_get_integrity(a) (0) #define blk_get_integrity(a) (0) #define blk_integrity_compare(a, b) (0) #define blk_integrity_register(a, b) (0) #define blk_integrity_unregister(a) do { } while (0); +#define blk_queue_max_integrity_segments(a, b) do { } while (0); +#define queue_max_integrity_segments(a) (0) +#define blk_integrity_merge_rq(a, b, c) (0) +#define blk_integrity_merge_bio(a, b, c) (0) #endif /* CONFIG_BLK_DEV_INTEGRITY */ diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index 8fcb6e0e9e72..d63533a4a59e 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -31,6 +31,12 @@ struct scsi_cmnd; #define SCSI_MAX_SG_CHAIN_SEGMENTS SCSI_MAX_SG_SEGMENTS #endif +/* + * DIX-capable adapters effectively support infinite chaining for the + * protection information scatterlist + */ +#define SCSI_MAX_PROT_SG_SEGMENTS 0xFFFF + /* * Special value for scanning to specify scanning or rescanning of all * possible channels, (target) ids, or luns on a given shost. diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index b7bdecb7b76e..d0a6a845f204 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -388,6 +388,7 @@ struct scsi_host_template { * of scatter-gather. */ unsigned short sg_tablesize; + unsigned short sg_prot_tablesize; /* * Set this if the host adapter has limitations beside segment count. @@ -599,6 +600,7 @@ struct Scsi_Host { int can_queue; short cmd_per_lun; short unsigned int sg_tablesize; + short unsigned int sg_prot_tablesize; short unsigned int max_sectors; unsigned long dma_boundary; /* @@ -823,6 +825,11 @@ static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost) return shost->prot_capabilities; } +static inline int scsi_host_prot_dma(struct Scsi_Host *shost) +{ + return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION; +} + static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type) { static unsigned char cap[] = { 0, -- cgit v1.2.3-59-g8ed1b