btrfs: remove item_size member of struct btrfs_clone_extent_info

The value of item_size of struct btrfs_clone_extent_info is always set to
the size of a non-inline file extent item, and in fact the infrastructure
that uses this structure (btrfs_punch_hole_range()) does not work with
inline file extents at all (and it is not supposed to).

So just remove that field from the structure and use directly
sizeof(struct btrfs_file_extent_item) instead. Also assert that the
file extent type is not inline at btrfs_insert_clone_extent().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -1200,8 +1200,8 @@ struct btrfs_clone_extent_info {
 	u64 data_offset;
 	u64 data_len;
 	u64 file_offset;
+	/* Pointer to a file extent item of type regular or prealloc. */
 	char *extent_buf;
-	u32 item_size;
 	/*
 	 * Set to true when attempting to replace a file range with a new extent
 	 * described by this structure, set to false when attempting to clone an

fs/btrfs/file.c

@@ -2596,15 +2596,16 @@ static int btrfs_insert_clone_extent(struct btrfs_trans_handle *trans,
 	key.type = BTRFS_EXTENT_DATA_KEY;
 	key.offset = clone_info->file_offset;
 	ret = btrfs_insert_empty_item(trans, root, path, &key,
-				      clone_info->item_size);
+				      sizeof(struct btrfs_file_extent_item));
 	if (ret)
 		return ret;
 	leaf = path->nodes[0];
 	slot = path->slots[0];
 	write_extent_buffer(leaf, clone_info->extent_buf,
 			    btrfs_item_ptr_offset(leaf, slot),
-			    clone_info->item_size);
+			    sizeof(struct btrfs_file_extent_item));
 	extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+	ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
 	btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
 	btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
 	if (clone_info->is_new_extent)

fs/btrfs/inode.c

@@ -9617,7 +9617,6 @@ static struct btrfs_trans_handle *insert_prealloc_file_extent(
 	extent_info.data_len = len;
 	extent_info.file_offset = file_offset;
 	extent_info.extent_buf = (char *)&stack_fi;
-	extent_info.item_size = sizeof(stack_fi);
 	extent_info.is_new_extent = true;
 	extent_info.qgroup_reserved = ret;
 	extent_info.insertions = 0;

fs/btrfs/reflink.c

@@ -462,7 +462,6 @@ static int btrfs_clone(struct inode *src, struct inode *inode,
 			clone_info.data_len = datal;
 			clone_info.file_offset = new_key.offset;
 			clone_info.extent_buf = buf;
-			clone_info.item_size = size;
 			clone_info.is_new_extent = false;
 			ret = btrfs_punch_hole_range(inode, path, drop_start,
 					new_key.offset + datal - 1, &clone_info,