Re: defrag deployment status (was Re: [PATCH] ext4: allow defrag (EXT4_IOC_MOVE_EXT) in 32bit compat mode)

[Eric Sandeen <sandeen@redhat.com>]

Jeff Garzik wrote:
> On 03/07/2010 03:32 PM, Christian Borntraeger wrote:
>> I have an x86_64 kernel with i386 userspace. e4defrag fails on the
>> EXT4_IOC_MOVE_EXT ioctl because it is not wired up for the compat
>> case. It seems that struct move_extent is compat save, only types
>> with fixed widths are used:
>> {
>>          __u32 reserved;         /* should be zero */
>>          __u32 donor_fd;         /* donor file descriptor */
>>          __u64 orig_start;       /* logical start offset in block for
>> orig */
>>          __u64 donor_start;      /* logical start offset in block for
>> donor */
>>          __u64 len;              /* block length to be moved */
>>          __u64 moved_len;        /* moved block length */
>> };
>>
>> Lets just wire up EXT4_IOC_MOVE_EXT for the compat case.
>>
>> Signed-off-by: Christian Borntraeger<borntraeger@de.ibm.com>
>> CCed: Akira Fujita<a-fujita@rs.jp.nec.com>
> 
> I'm curious, what is the overall deployment status of ext4 defragging? I
> actually worked on this problem years ago[1], and am hopeful that I will
> see defragging in a Linux distribution sometime in my lifetime!  ;-)

on ext4 you mean, I guess - you could use XFS if defragging is a high priority,
see xfs_fsr(8)

> Looking at Fedora rawhide, I do not see anything resembling e4defrag in
> any of the RPM packages like e2fsprogs.

I had it for a while, but with the various problems and general uneasiness
with the code so far, I took it back out lest people lose data to it.

-Eric

> Thanks to everyone working on this,
> 
>     Jeff
> 
> 
> 
> 
> [1] http://linux.yyz.us/misc/ext2meta.c