Re: [PATCH COW] sys_copyfile

[Steve French <smfltc@us.ibm.com>]

On Tue, 2004-04-27 at 11:42, Jörn Engel wrote:

> Shouldn't it be rather
> 
> 	if (old_nd->dentry->d_inode->i_op->copy)
> 		return old_nd->dentry->d_inode->i_op->copy(old_nd->dentry,
> 				mode, new_dentry);
> 
> or something similar?  The copy() effectively replaces the complete
> create/sendfile/possibly-unlink series.
> 

In some network protocols the client does not know whether the server
wants to support copy operation or not (perhaps if the files were on
different server partitions the server might return an error e.g), in
those cases the filesystem client could return error not supported or
equivalent and the remainder of your function is executed doing the copy
the harder way (open/read/close create/write/close) but still faster a
few percent faster than before your patch.