block: support pi with extended metadata

The nvme spec allows protection information formats with metadata
extending beyond the pi field. Use the actual size of the metadata field
for incrementing the buffer.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20220303201312.3255347-2-kbusch@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/bio-integrity.c

@@ -165,6 +165,7 @@ static blk_status_t bio_integrity_process(struct bio *bio,
 
 	iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
 	iter.interval = 1 << bi->interval_exp;
+	iter.tuple_size = bi->tuple_size;
 	iter.seed = proc_iter->bi_sector;
 	iter.prot_buf = bvec_virt(bip->bip_vec);
 

block/t10-pi.c

@@ -44,7 +44,7 @@ static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
 			pi->ref_tag = 0;
 
 		iter->data_buf += iter->interval;
-		iter->prot_buf += sizeof(struct t10_pi_tuple);
+		iter->prot_buf += iter->tuple_size;
 		iter->seed++;
 	}
 
@@ -93,7 +93,7 @@ static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
 
 next:
 		iter->data_buf += iter->interval;
-		iter->prot_buf += sizeof(struct t10_pi_tuple);
+		iter->prot_buf += iter->tuple_size;
 		iter->seed++;
 	}
 

include/linux/blk-integrity.h

@@ -19,6 +19,7 @@ struct blk_integrity_iter {
 	sector_t		seed;
 	unsigned int		data_size;
 	unsigned short		interval;
+	unsigned char		tuple_size;
 	const char		*disk_name;
 };