[Ocfs2-devel] [PATCH 04/15] Make extend allocation generic.

[Tao Ma]

Joel Becker wrote:
> On Thu, Aug 07, 2008 at 06:31:26AM +0800, Tao Ma wrote:
>> The old ocfs2_do_extend_allocation is restrictly to be used in file
>> extension. Now a new function named ocfs2_do_cluster_allocation will
>> handle the issue of generic extend allocation and it is created in
>> suballoc.c.
> 
> <snip> 
> 
>> +int ocfs2_add_clusters_in_btree(struct ocfs2_super *osb,
>> +				struct inode *inode,
>> +				u32 *logical_offset,
>> +				u32 clusters_to_add,
>> +				int mark_unwritten,
>> +				struct buffer_head *root_bh,
>> +				struct ocfs2_extent_list *root_el,
>> +				handle_t *handle,
>> +				struct ocfs2_alloc_context *data_ac,
>> +				struct ocfs2_alloc_context *meta_ac,
>> +				enum ocfs2_alloc_restarted *reason_ret,
>> +				enum ocfs2_extent_tree_type type)
> 
> 	It seems to me that if you have root_bh and type, you can create
> an ocfs2_extent_tree and calculate root_el from that.  So you don't need
> root_el in this function's arguments, and callers don't need to know how
> to compute it.
No we can't. For a ocfs2_xattr_value_root. It can be stored in any place 
of a buffer_head, so we have to give it to this function.

Regards,
Tao