[Ocfs2-tools-devel] [patch 11/11] Some minor modification in other files.

[tao.ma]

Mark Fasheh wrote:
> On Thu, Aug 16, 2007 at 01:56:29AM +0800, tao.ma wrote:
>   
>> ===================================================================
>> --- test.ocfs2-tools.orig/fswreck/extent.c	2007-08-16 00:27:44.000000000 -0400
>> +++ test.ocfs2-tools/fswreck/extent.c	2007-08-16 00:36:28.000000000 -0400
>> @@ -84,7 +84,7 @@ static void custom_extend_allocation(ocf
>>  {
>>  	errcode_t ret;
>>  	uint32_t n_clusters;
>> -	uint32_t i;
>> +	uint32_t i, offset = 0;
>>  	uint64_t blkno;
>>  	uint64_t tmpblk;
>>  
>> @@ -103,7 +103,8 @@ static void custom_extend_allocation(ocf
>>  		 * we insert each cluster in reverse. */
>>  		for(i = n_clusters; i; --i) {
>>  			tmpblk = blkno + ocfs2_clusters_to_blocks(fs, i - 1);
>> -		 	ret = ocfs2_insert_extent(fs, ino, tmpblk, 1);
>> +		 	ret = ocfs2_insert_extent(fs, ino, offset++,
>> +						  tmpblk, 1);
>>     
>
> Hmm... I'm not 100% sure what this function is supposed to do, but it
> _looks_ like it's trying to grow allocation based on the rightmost allocated
> cluster. Shouldn't 'offset' above start at the rightmost rec cpos + clusters
> then? Starting at '0' means you'll just try to allocate over existing
> records...
> 	--Mark
>   
This function is used to speed up the grow of extent record and extent 
block.
You know if I allocate 10 clusters from the bitmap, and even if I call 
insert_extent 10 times once a cluster, there will be only 1 extent 
record since the clusters are contiguous and they will be merged into 
one extent record. But considering I insert the last cluster first, say 
10,9,8...1, then these clusters will not be merged into one extent 
record, so the inode will have 10 extent records.
I use these function in fswreck to quickly build up a inode with many 
extent blocks with less disk space. ;)

> --
> Mark Fasheh
> Senior Software Developer, Oracle
> mark.fasheh at oracle.com
>