[PATCH v5 36/52] btrfs: add orig_logical to btrfs_bio

[Josef Bacik <josef@toxicpanda.com>]

When checksumming the encrypted bio on writes we need to know which
logical address this checksum is for.  At the point where we get the
encrypted bio the bi_sector is the physical location on the target disk,
so we need to save the original logical offset in the btrfs_bio.  Then
we can use this when csum'ing the bio instead of the
bio->iter.bi_sector.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/bio.c       | 10 ++++++++++
 fs/btrfs/bio.h       |  3 +++
 fs/btrfs/file-item.c |  2 +-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
index fc5c56a9d25f..cb998048edce 100644
--- a/fs/btrfs/bio.c
+++ b/fs/btrfs/bio.c
@@ -96,6 +96,8 @@ static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info,
 	if (bbio_has_ordered_extent(bbio)) {
 		refcount_inc(&orig_bbio->ordered->refs);
 		bbio->ordered = orig_bbio->ordered;
+		bbio->orig_logical = orig_bbio->orig_logical;
+		orig_bbio->orig_logical += map_length;
 	}
 	atomic_inc(&orig_bbio->pending_ios);
 	return bbio;
@@ -678,6 +680,14 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 		goto fail;
 	}
 
+	/*
+	 * For fscrypt writes we will get the encrypted bio after we've remapped
+	 * our bio to the physical disk location, so we need to save the
+	 * original bytenr so we know what we're checksumming.
+	 */
+	if (bio_op(bio) == REQ_OP_WRITE && is_data_bbio(bbio))
+		bbio->orig_logical = logical;
+
 	map_length = min(map_length, length);
 	if (use_append)
 		map_length = min(map_length, fs_info->max_zone_append_size);
diff --git a/fs/btrfs/bio.h b/fs/btrfs/bio.h
index bbaed317161a..a5c5371e99e2 100644
--- a/fs/btrfs/bio.h
+++ b/fs/btrfs/bio.h
@@ -54,11 +54,14 @@ struct btrfs_bio {
 		 * - pointer to the checksums for this bio
 		 * - original physical address from the allocator
 		 *   (for zone append only)
+		 * - original logical address, used for checksumming fscrypt
+		 *   bios.
 		 */
 		struct {
 			struct btrfs_ordered_extent *ordered;
 			struct btrfs_ordered_sum *sums;
 			u64 orig_physical;
+			u64 orig_logical;
 		};
 
 		/* For metadata reads: parentness verification. */
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 6264cb837dcf..a7e545e7461f 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -756,7 +756,7 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio, struct bio *bio)
 	sums->len = bio->bi_iter.bi_size;
 	INIT_LIST_HEAD(&sums->list);
 
-	sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+	sums->logical = bbio->orig_logical;
 	index = 0;
 
 	shash->tfm = fs_info->csum_shash;
-- 
2.43.0