Re: TAKE 972756 - Implement fallocate.

[nscott@aconex.com]

> Since size log change and data I/O are not binded, it is always possible
> that size can reach to the
> disk before I/O reaching to the disk.

Not clear what that has to do with whether partial blocks are zeroed or not?
Can you give a specific series of steps that would demonstrate a problem?
(preferably with a test case)

> Also, the other problem is because
> of
> speculative allocation.
> A write-back allocation can leady to allocation of delayed extents into
> real
> and gets pruned only
> close of the file.
> Before that, we get fallocate, it allocates the exents,
> but the extents residing
> because of delayed allocation write-back will not have zero'ed content.

Again, I think a test case demonstrating the problem would go a long way
to helping explain the issue.

The preallocation code and ioctl interface have been in XFS forever on
Linux - are you reporting problems you've actually observed here, or
are these rather "potential issues" that you foresee from code analysis?

cheers.

--
Nathan