[Ocfs2-tools-devel] [patch 02/11] Modify e_clusters used in the ocfs2-tools.

[tao.ma]

Mark Fasheh wrote:
> On Thu, Aug 16, 2007 at 01:54:47AM +0800, tao.ma wrote:
>   
>> @@ -286,6 +289,13 @@ static errcode_t check_el(o2fsck_state *
>>  
>>  	for (i = 0; i < max_recs; i++) {
>>  		er = &el->l_recs[i];
>> +		clusters = ocfs2_rec_clusters(el->l_tree_depth, er);
>> +
>> +		/* For a sparse file, we may find an empty record
>> +		 * in the left most record. Just skip it.
>> +		 */
>> +		if (el->l_tree_depth && !i && !clusters)
>> +			continue;
>>     
>
> Fsck probably wants to be extra conservative and only skip it if the sparse
> files flag is set.
>   
yes, the incompat flag need to be checked here. Thanks.
>
>   
>> @@ -334,9 +344,11 @@ static int extent_iterate_eb(struct ocfs
>>  	if (flags & (OCFS2_EXTENT_ABORT | OCFS2_EXTENT_ERROR))
>>  		iret |= flags & (OCFS2_EXTENT_ABORT | OCFS2_EXTENT_ERROR);
>>  
>> -	/* if the list was changed and we still have recs then we need
>> -	 * to write the changes to disk */
>> -	if (changed & OCFS2_EXTENT_CHANGED && el->l_next_free_rec) {
>> +	/* If the list was changed, we should write the changes to disk.
>> +	 * Note:
>> +	 * For a sparse file, we may have an empty extent block.
>> +	 */
>> +	if (changed & OCFS2_EXTENT_CHANGED) {
>>  		ctxt->errcode = ocfs2_write_extent_block(ctxt->fs,
>>  							 eb_rec->e_blkno,
>>  						ctxt->eb_bufs[tree_depth]);
>>     
>
> Hmm, not quite. I don't believe any version of ocfs2 should ever be writing out
> extent blocks with l_next_free_rec == 0. What we'd really have is an extent
> block with l_next_free_rec == 1 and an empty extent in index 0.
>   
Hi, this is used for another special case ocfs2_truncate.
In ocfs2_truncate, when we find the first extent rec of a extent block 
need to be freed, we clean the extent rec and in this case the first 
extent rec is empty. See r1323 for more details.