btrfs: rename struct btrfs_io_bio to btrfs_bio

Previously we had "struct btrfs_bio", which records IO context for
mirrored IO and RAID56, and "strcut btrfs_io_bio", which records extra
btrfs specific info for logical bytenr bio.

With "btrfs_bio" renamed to "btrfs_io_context", we are safe to rename
"btrfs_io_bio" to "btrfs_bio" which is a more suitable name now.

The struct btrfs_bio changes meaning by this commit. There was a
suggested name like btrfs_logical_bio but it's a bit long and we'd
prefer to use a shorter name.

This could be a concern for backports to older kernels where the
different meaning could possibly cause confusion or bugs. Comparing the
new and old structures, there's no overlap among the struct members so a
build would break in case of incorrect backport.

We haven't had many backports to bio code anyway so this is more of a
theoretical cause of bugs and a matter of precaution but we'll need to
keep the semantic change in mind.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 6 insertions, 7 deletions

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 0b9401a5afd3..ddb9c7ee796f 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -358,7 +358,7 @@ static int search_file_offset_in_bio(struct bio *bio, struct inode *inode,
  * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
  *       checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
  *       NULL, the checksum buffer is allocated and returned in
- *       btrfs_io_bio(bio)->csum instead.
+ *       btrfs_bio(bio)->csum instead.
  *
  * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
  */
@@ -397,19 +397,18 @@ blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst
 		return BLK_STS_RESOURCE;
 
 	if (!dst) {
-		struct btrfs_io_bio *btrfs_bio = btrfs_io_bio(bio);
+		struct btrfs_bio *bbio = btrfs_bio(bio);
 
 		if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
-			btrfs_bio->csum = kmalloc_array(nblocks, csum_size,
-							GFP_NOFS);
-			if (!btrfs_bio->csum) {
+			bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
+			if (!bbio->csum) {
 				btrfs_free_path(path);
 				return BLK_STS_RESOURCE;
 			}
 		} else {
-			btrfs_bio->csum = btrfs_bio->csum_inline;
+			bbio->csum = bbio->csum_inline;
 		}
-		csum = btrfs_bio->csum;
+		csum = bbio->csum;
 	} else {
 		csum = dst;
 	}