[Ocfs2-tools-devel] a patch for fswreck of ocfs2-tools

[tao.ma]

Joel Becker wrote:

>On Wed, Aug 30, 2006 at 09:23:55AM +0800, tao.ma wrote:
>  
>
>>You are right. In fswreck, we need to create some special files with 
>>deeper trees and with this flag we can easily do that.
>>You know, if we create a file and extend it, it is quite slow to make a 
>>file with deep tree.
>>And since this flag is not used by other tools or lib functions, I don't 
>>see any  influence to  others.
>>    
>>
>
>	It's part of the public interface.  We shouldn't have a
>fully-generic flag in the public API for some wacky debugging scheme.
>I'm going to have to NAK it.
>	Now, I understand what you are trying to do.  You could try a
>couple other approaches.  One would be to modify each extent_list as it
>is allocated to have an l_count of 1.  That way, the regular allocation
>code will consider the extent_list full after one record.  You could
>basically open-code ocfs2_extend_allocation() in your application and make sure to modify l_count on any new extent_block->h_list.
>  
>
Change l_count to 1 won't be helpful. You know when we try 
ocfs2_extend_allocation of a file, it will allocate a block from the 
bitmap and then try to set this block num to the extent list. Under my 
circumstance, I will create a file at one time, so now matter how many 
block I create, the block nums will be allocated contiguously and only 
the 0 entry will be enlarged. So only one extent_rec is needed actually.

Anyway, I will open-code ocfs2_extend_allocation in my own tools, and 
try to solve this problem. Will resend the patch later.

>	Another less interesting (from the library perspective)
>possibility would be to add an internal ocfs2_insert_extent_real()
>function.  This would not live in the ocfs2.h header, but in a private
>header.  It would take an argument setting a flag on the struct
>insert_context resulting in the behavior you want.  The
>ocfs2_insert_extent() function would then call
>ocfs2_insert_extent_real() with the appropriate flag unset.
>
>Joel
>
>  
>


-- 
* **     Tao Ma
*     Member of Techincal Staff *

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