On Wed, 2007-05-09 at 21:31 +0530, Amit K. Arora wrote:

I have the updated patches ready which take care of Andrew's comments.
Will run some tests and post them soon.

But, before submitting these patches, I think it will be better to finalize
on certain things which might be worth some discussion here:

1) Should the file size change when preallocation is done beyond EOF ?
   - Andreas and Chris Wedgwood are in favor of not changing the
     file size in this case. I also tend to agree with them. Does anyone
     has an argument in favor of changing the filesize ?
     If not, I will remove the code which changes the filesize, before I
     resubmit the concerned ext4 patch.

If we chose not to update the file size beyong EOF, then for filesystem
without fallocate() support (ext2,3 currently), posix_fallocate() will
follow the hard way(zero-out) to do preallocation. Then we will get
different behavior on filesystems w/o fallocate() support. It make sense
to be consistent, IMO.

My point of view, preallocation is just a efficient way to allocating
blocks for files without zero-out, other than this, the new behavior
should be consistent with the old way: file size update,mtime/ctime,
ENOSPC etc.

Mingming