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, 3 insertions, 0 deletions

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index ae7aec3cabe..524ec96f5a2 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -141,6 +141,9 @@ struct gendisk {
         struct disk_stats dkstats;
 #endif
         struct work_struct async_notify;
+#ifdef  CONFIG_BLK_DEV_INTEGRITY
+        struct blk_integrity *integrity;
+#endif
 };
 
 /*