[PATCH v3 1/6] block: use integrity interval instead of sector as seed

[Caleb Sander Mateos]

bio_integrity_setup_default() and blk_integrity_iterate() set the
integrity seed (initial reference tag) to the absolute address in the
block device in units of 512-byte sectors. The seed is correctly
incremented/decremented in units of integrity intervals in
bio_integrity_map_iter(), bio_integrity_advance(), and
blk_integrity_interval(). As a result, the ref tag written or read to a
particular integrity interval on a block device with integrity interval
size > 512 bytes varies with the starting offset of the read/write.

Convert the initial seed to units of integrity intervals so a consistent
ref tag is used for each integrity interval.

Fixes: 3be91c4a3d09 ("block: Deprecate the use of the term sector in the context of block integrity")
Fixes: 63573e359d05 ("bio-integrity: Restore original iterator on verify stage")
Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
Reviewed-by: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
 block/bio-integrity.c | 3 ++-
 block/t10-pi.c        | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/block/bio-integrity.c b/block/bio-integrity.c
index e79eaf047794..3ad6a6799f17 100644
--- a/block/bio-integrity.c
+++ b/block/bio-integrity.c
@@ -103,12 +103,13 @@ void bio_integrity_free_buf(struct bio_integrity_payload *bip)
 
 void bio_integrity_setup_default(struct bio *bio)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);
+	u64 seed = bio->bi_iter.bi_sector >> (bi->interval_exp - SECTOR_SHIFT);
 
-	bip_set_seed(bip, bio->bi_iter.bi_sector);
+	bip_set_seed(bip, seed);
 
 	if (bi->csum_type) {
 		bip->bip_flags |= BIP_CHECK_GUARD;
 		if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
 			bip->bip_flags |= BIP_IP_CHECKSUM;
diff --git a/block/t10-pi.c b/block/t10-pi.c
index a19b4e102a83..e58d5eb6cefb 100644
--- a/block/t10-pi.c
+++ b/block/t10-pi.c
@@ -308,18 +308,19 @@ static blk_status_t blk_integrity_iterate(struct bio *bio,
 					  struct bvec_iter *data_iter,
 					  bool verify)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);
+	u64 seed = data_iter->bi_sector >> (bi->interval_exp - SECTOR_SHIFT);
 	struct blk_integrity_iter iter = {
 		.bio = bio,
 		.bip = bip,
 		.bi = bi,
 		.data_iter = *data_iter,
 		.prot_iter = bip->bip_iter,
 		.interval_remaining = 1 << bi->interval_exp,
-		.seed = data_iter->bi_sector,
+		.seed = seed,
 		.csum = 0,
 	};
 	blk_status_t ret = BLK_STS_OK;
 
 	while (iter.data_iter.bi_size && ret == BLK_STS_OK) {
-- 
2.45.2