Re: Review of ext4-online-defrag-check-for-freespace-fragmentation.patch

[Akira Fujita <a-fujita@rs.jp.nec.com>]

Hi Ted,

Theodore Tso wrote:
> On Sat, Sep 13, 2008 at 06:16:42PM -0400, Theodore Ts'o wrote:
>> Secondly, some of the ioctl numbers chosen by the defrag patches overlap
>> other, already existing patches.  This is something we will need to fix,
>> long term.  For now, folks should know that we can't count on the ioctl
>> numbers being stable, since we will probably need to move them.
> 
> Note: I have done this in the version of the defrag patches in the
> ext4 patch queue, where all of the ioctl's introduced by the defrag
> patches have been renumbered starting at 15, to avoid conflicts with
> other ioctls that either exist already or could be introduced in the
> future.
> 
> If you don't mind, we can also merge up some of the patches that have
> been inserted in the patch queue, and then you can start working from
> the modified version in the patch queue.  The other way to move
> forward is that we can start creating new ioctl's that are more
> general and have carefully designed interfaces, and then as the
> replacement ioctl's are created, the defrag patches can be shortened
> and the on-line defrag command modified to use the new ioctl's.

I see, I will use the renumbered defrag patches in the patch queue.
(Currently, I am working on the defrag to use FS_IOC_FIEMAP
  instead of EXT4_IOC_EXTENTS_INFO and remove block size limitation
  to support 1KB and 2KB block size.  I will release them soon.)

Thanks,
Akira Fujita