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>

1 files changed, 2 insertions, 5 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 49f3461..7fcb2ca 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1514,12 +1514,9 @@ static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
 	return disk->integrity;
 }
 
-static inline int blk_integrity_rq(struct request *rq)
+static inline bool blk_integrity_rq(struct request *rq)
 {
-	if (rq->bio == NULL)
-		return 0;
-
-	return bio_integrity(rq->bio);
+	return rq->cmd_flags & REQ_INTEGRITY;
 }
 
 static inline void blk_queue_max_integrity_segments(struct request_queue *q,