btrfs: add orig_logical to btrfs_bio for encryption

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 checksumming the bio instead of the
bio->iter.bi_sector.

Note: The patch was taken from v5 of fscrypt patchset
(https://lore.kernel.org/linux-btrfs/cover.1706116485.git.josef@toxicpanda.com/)
which was handled over time by various people: Omar Sandoval, Sweet Tea
Dorminy, Josef Bacik.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
index 1b38e3ee0a3365c674fa6296906a0c74c18f4e5c..fa1d321a2fb83861b9b42bd422ce0a4edf3343ab 100644 (file)
--- a/fs/btrfs/bio.c
+++ b/fs/btrfs/bio.c
@@ -94,6 +94,8 @@ 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;
        }
        bbio->csum_search_commit_root = orig_bbio->csum_search_commit_root;
        atomic_inc(&orig_bbio->pending_ios);
@@ -765,6 +767,14 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
                goto end_bbio;
        }
 
+       /*
+        * 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 = btrfs_append_map_length(bbio, map_length);

diff --git a/fs/btrfs/bio.h b/fs/btrfs/bio.h
index 035145909b003c9a0eb80ca09a953285a0674639..1be74209f0b8dbeafd8e38b35ffce29d19f3af4e 100644 (file)
--- a/fs/btrfs/bio.h
+++ b/fs/btrfs/bio.h
@@ -52,6 +52,7 @@ 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;
@@ -60,6 +61,7 @@ struct btrfs_bio {
                        struct completion csum_done;
                        struct bvec_iter csum_saved_iter;
                        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 b17632ea085f255d658d979ae97cf8baaf5b7013..14e5257f0f04444a89d1c92b094a256ac827c3d7 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -824,7 +824,7 @@ int btrfs_csum_one_bio(struct btrfs_bio *bbio, bool async)
        if (!sums)
                return -ENOMEM;
 
-       sums->logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+       sums->logical = bbio->orig_logical;
        sums->len = bio->bi_iter.bi_size;
        INIT_LIST_HEAD(&sums->list);
        bbio->sums = sums;