Re: XFS capacity leak with dmapi

Vlad Apostolov
2007-07-11T23:35:47Z

John Groves wrote:
> Vlad, I've tried to send this via linux-xfs, but for some reason my
> posts aren't going through (although I receive messages from it every
> day). Any ideas on this?
>
> We have an application that uses DMAPI, and we've been chasing an XFS
> filesystem capacity leak for a week or two. Here is the scenario:
>
> In some cases we initially create sparse files - normal open with
> O_CREAT and than an ftruncate to the desired size.
>
> If we subsequently fill the files via dm_write_invis(), and then
> remove/unlink the files, XFS does not appear to free up the capacity
> that was allocated when the file was made non-sparse via
> dm_write_invis(). Repeating this sequence enough times results in a
> full filesystem.
>
> If we use write() to fill the file (after creating it as sparse),
> remove/unlink appears to work properly, and capacity does not appear
> to be leaked. We've seen this on several test systems; the current
> one is 2.6.22-rc4, which I think is current as to the SGI cvs tree (or
> very nearly so).
>
> Can anybody shed light on this?
>
> Thanks,
> John Groves
Hi John,

I will investigate this problem but at the moment I can't immediately jump
on it. I am copying the email to linux-xfs list in case if someone could
answer it straightaway.

Regards,
Vlad