[PATCH V2] xfs: truncate_setsize should be outside transactions

[Christoph Hellwig]

On Sat, May 03, 2014 at 09:23:39AM +1000, Dave Chinner wrote:
> before we get to the transaction that can fail:
> block_truncate_page() zeroes the tail of the page cache page. Hence
> if the transaction reservation fails, we've already trashed the file
> data - we may as well finish off the job and at least make it look
> like the truncate succeeded from a user point of view. They then get
> a ENOMEM error (only non-fatal error that can come from
> xfs_trans_reserve) and try the truncate again....

I don't think we can even get the ENOMEM.  But yeah, I guess
we want something like the old version, with comments explaining exactly
we we have this order.