On Oct 23, 2006 18:31 +0400, Alex Tomas wrote: > isn't that a kernel responsbility to find/allocate target blocks? > wouldn't it better to specify desirable target group and minimal > acceptable chunk of free blocks? In some cases this is useful (e.g. if file has small fragments after being written in small pieces or in a fragmented free space). In other cases the user tool HAS to be able to specify the new mapping in order to make progress. Consider if there are two very large fragmented files and user-space defrag tool wants to make contiguous free space. If kernel is left to do allocation it will always consume the largest chunk of free space first, even if it is not yet optimal (e.g. large 1MB aligned extent). I would make this interface optionally allow the target extent to be specified, but if target block == 0 then the kernel is free to do its own allocation. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
