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 <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
This commit is contained in:
Martin K. Petersen
2010-09-10 20:50:10 +02:00
committed by Jens Axboe
parent c8bf133682
commit 13f05c8d8e
12 changed files with 167 additions and 50 deletions

View File

@@ -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 */