Re: [PATCH] vfs: reorganize inode chattr checks

[Nick Piggin <npiggin@suse.de>]

On Wed, Mar 17, 2010 at 08:09:12PM +0300, Dmitry Monakhov wrote:
> 
> This patch fix nasty bug with truncate on swapfile.
> It contains only vfs core helpers and fix isize check path for
> fs w/o i_op->setattr method. Later i'll send corresponding changes
> to other fs which has ->setattr method.
> 
> This patch is depends on Nick's patch
> http://marc.info/?l=linux-fsdevel&m=126752788514574&w=2
> 

> >From e8587585b2e2fefb75d47f8d50ddc7099a50873c Mon Sep 17 00:00:00 2001
> From: Dmitry Monakhov <dmonakhov@openvz.org>
> Date: Wed, 17 Mar 2010 19:49:22 +0300
> Subject: [PATCH] vfs: reorganize inode chattr checks
> 
> vmtrucate may fail due to IS_SWAPFILE flag or due to RLIMIT_FSIZE.
> In some situations it is not acceptable behaviour. Off course
> we can check IS_SWAPFILE before but what about RLIMIT_FSIZE?
> 
> Let's divide newsize seting logic in two parts
>  First which perform necessery size checks
>  Second which does the work and can not fail.
> And perform size check before any inode modifications.

Yep, I think it is a good idea to perform these checks as early as
possible.