btrfs: btrfs_multi_bio replaced with btrfs_bio

btrfs_bio is a bio abstraction able to split and not complete after the last
bio has returned (like the old btrfs_multi_bio). Additionally, btrfs_bio
tracks the mirror_num used to read data which can be used for error
correction purposes.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 6d866db4e177..71f4f3f67495 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -136,7 +136,10 @@ struct btrfs_bio_stripe {
         u64 length; /* only used for discard mappings */
 };
 
-struct btrfs_multi_bio {
+struct btrfs_bio;
+typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
+
+struct btrfs_bio {
         atomic_t stripes_pending;
         bio_end_io_t *end_io;
         struct bio *orig_bio;
@@ -144,6 +147,7 @@ struct btrfs_multi_bio {
         atomic_t error;
         int max_errors;
         int num_stripes;
+        int mirror_num;
         struct btrfs_bio_stripe stripes[];
 };
 
@@ -171,7 +175,7 @@ struct map_lookup {
 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
                                    u64 end, u64 *length);
 
-#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
+#define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
                             (sizeof(struct btrfs_bio_stripe) * (n)))
 
 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
@@ -180,7 +184,7 @@ int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
                            u64 chunk_offset, u64 start, u64 num_bytes);
 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
                     u64 logical, u64 *length,
-                    struct btrfs_multi_bio **multi_ret, int mirror_num);
+                    struct btrfs_bio **bbio_ret, int mirror_num);
 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
                      u64 chunk_start, u64 physical, u64 devid,
                      u64 **logical, int *naddrs, int *stripe_len);