[RFC 1/7] block: support pi with extended metadata

[Keith Busch]

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 protection buffer.

Cc: "Martin K. Petersen" <martin.petersen at oracle.com>
Signed-off-by: Keith Busch <kbusch at kernel.org>
---
 block/bio-integrity.c         | 1 +
 block/t10-pi.c                | 4 ++--
 include/linux/blk-integrity.h | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index d25114715459..e40b1f965960 100644
--- a/block/bio-integrity.c
+++ b/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);
 
diff --git a/block/t10-pi.c b/block/t10-pi.c
index 25a52a2a09a8..758a76518854 100644
--- a/block/t10-pi.c
+++ b/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++;
 	}
 
diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index 8a038ea0717e..378b2459efe2 100644
--- a/include/linux/blk-integrity.h
+++ b/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;
 };
 
-- 
2.25.4