btrfs: Deduplicate extent_buffer init code

When a new extent buffer is allocated there are a few mandatory fields
which need to be set in order for the buffer to be sane: level,
generation, bytenr, backref_rev, owner and FSID/UUID. Currently this
is open coded in the callers of btrfs_alloc_tree_block, meaning it's
fairly high in the abstraction hierarchy of operations. This patch
solves this by simply moving this init code in btrfs_init_new_buffer,
since this is the function which initializes a newly allocated
extent buffer. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 0 insertions, 8 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0c4b9f364e84..08b8c0b346b3 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -616,14 +616,6 @@ static noinline int create_subvol(struct inode *dir,
                 goto fail;
         }
 
-        memzero_extent_buffer(leaf, 0, sizeof(struct btrfs_header));
-        btrfs_set_header_bytenr(leaf, leaf->start);
-        btrfs_set_header_generation(leaf, trans->transid);
-        btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
-        btrfs_set_header_owner(leaf, objectid);
-
-        write_extent_buffer_fsid(leaf, fs_info->fsid);
-        write_extent_buffer_chunk_tree_uuid(leaf, fs_info->chunk_tree_uuid);
         btrfs_mark_buffer_dirty(leaf);
 
         inode_item = &root_item->inode;