block: Replace bi_integrity with bi_special

For commands like REQ_COPY we need a way to pass extra information along
with each bio. Like integrity metadata this information must be
available at the bottom of the stack so bi_private does not suffice.

Rename the existing bi_integrity field to bi_special and make it a union
so we can have different bio extensions for each class of command.

We previously used bi_integrity != NULL as a way to identify whether a
bio had integrity metadata or not. Introduce a REQ_INTEGRITY to be the
indicator now that bi_special can contain different things.

In addition, bio_integrity(bio) will now return a pointer to the
integrity payload (when applicable).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Martin K. Petersen 2014-09-26 19:19:56 -04:00 committed by Jens Axboe
commit 180b2f95dd
6 changed files with 36 additions and 27 deletions

View file

@ -293,6 +293,15 @@ static inline unsigned bio_segments(struct bio *bio)
#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
#if defined(CONFIG_BLK_DEV_INTEGRITY)
static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
{
if (bio->bi_rw & REQ_INTEGRITY)
return bio->bi_integrity;
return NULL;
}
/*
* bio integrity payload
*/
@ -661,8 +670,6 @@ struct biovec_slab {
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(struct bio *, gfp_t, unsigned int);
extern void bio_integrity_free(struct bio *);
extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);