block: Block layer data integrity support

Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.

This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.

See Documentation/block/data-integrity.txt for more information.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 1905aaba49fb..e0fb0bcc0c17 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -143,6 +143,10 @@ static void req_bio_endio(struct request *rq, struct bio *bio,
 
                 bio->bi_size -= nbytes;
                 bio->bi_sector += (nbytes >> 9);
+
+                if (bio_integrity(bio))
+                        bio_integrity_advance(bio, nbytes);
+
                 if (bio->bi_size == 0)
                         bio_endio(bio, error);
         } else {
@@ -1381,6 +1385,9 @@ end_io:
                  */
                 blk_partition_remap(bio);
 
+                if (bio_integrity_enabled(bio) && bio_integrity_prep(bio))
+                        goto end_io;
+
                 if (old_sector != -1)
                         blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
                                             old_sector);