btrfs: lift bio_set_dev from bio allocation helpers

The block device is passed around for the only purpose to set it in new
bios. Move the assignment one level up. This is a preparatory patch for
further bdev cleanups.
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.c

@@ -340,7 +340,8 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 
 	bdev = fs_info->fs_devices->latest_bdev;
 
-	bio = btrfs_bio_alloc(bdev, first_byte);
+	bio = btrfs_bio_alloc(first_byte);
+	bio_set_dev(bio, bdev);
 	bio->bi_opf = REQ_OP_WRITE | write_flags;
 	bio->bi_private = cb;
 	bio->bi_end_io = end_compressed_bio_write;
@@ -382,7 +383,8 @@ blk_status_t btrfs_submit_compressed_write(struct inode *inode, u64 start,
 				bio_endio(bio);
 			}
 
-			bio = btrfs_bio_alloc(bdev, first_byte);
+			bio = btrfs_bio_alloc(first_byte);
+			bio_set_dev(bio, bdev);
 			bio->bi_opf = REQ_OP_WRITE | write_flags;
 			bio->bi_private = cb;
 			bio->bi_end_io = end_compressed_bio_write;
@@ -620,7 +622,8 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 	/* include any pages we added in add_ra-bio_pages */
 	cb->len = bio->bi_iter.bi_size;
 
-	comp_bio = btrfs_bio_alloc(bdev, cur_disk_byte);
+	comp_bio = btrfs_bio_alloc(cur_disk_byte);
+	bio_set_dev(comp_bio, bdev);
 	comp_bio->bi_opf = REQ_OP_READ;
 	comp_bio->bi_private = cb;
 	comp_bio->bi_end_io = end_compressed_bio_read;
@@ -670,7 +673,8 @@ blk_status_t btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
 				bio_endio(comp_bio);
 			}
 
-			comp_bio = btrfs_bio_alloc(bdev, cur_disk_byte);
+			comp_bio = btrfs_bio_alloc(cur_disk_byte);
+			bio_set_dev(comp_bio, bdev);
 			comp_bio->bi_opf = REQ_OP_READ;
 			comp_bio->bi_private = cb;
 			comp_bio->bi_end_io = end_compressed_bio_read;

fs/btrfs/extent_io.c

@@ -2861,12 +2861,11 @@ static inline void btrfs_io_bio_init(struct btrfs_io_bio *btrfs_bio)
  * never fail.  We're returning a bio right now but you can call btrfs_io_bio
  * for the appropriate container_of magic
  */
-struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte)
+struct bio *btrfs_bio_alloc(u64 first_byte)
 {
 	struct bio *bio;
 
 	bio = bio_alloc_bioset(GFP_NOFS, BIO_MAX_PAGES, &btrfs_bioset);
-	bio_set_dev(bio, bdev);
 	bio->bi_iter.bi_sector = first_byte >> 9;
 	btrfs_io_bio_init(btrfs_io_bio(bio));
 	return bio;
@@ -2977,7 +2976,8 @@ static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
 		}
 	}
 
-	bio = btrfs_bio_alloc(bdev, offset);
+	bio = btrfs_bio_alloc(offset);
+	bio_set_dev(bio, bdev);
 	bio_add_page(bio, page, page_size, pg_offset);
 	bio->bi_end_io = end_io_func;
 	bio->bi_private = tree;

fs/btrfs/extent_io.h

@@ -497,7 +497,7 @@ void extent_clear_unlock_delalloc(struct inode *inode, u64 start, u64 end,
 				 u64 delalloc_end, struct page *locked_page,
 				 unsigned bits_to_clear,
 				 unsigned long page_ops);
-struct bio *btrfs_bio_alloc(struct block_device *bdev, u64 first_byte);
+struct bio *btrfs_bio_alloc(u64 first_byte);
 struct bio *btrfs_io_bio_alloc(unsigned int nr_iovecs);
 struct bio *btrfs_bio_clone(struct bio *bio);
 struct bio *btrfs_bio_clone_partial(struct bio *orig, int offset, int size);