Re: [dm-devel] [PATCH] deadlock with suspend and quotas

[Mikulas Patocka <mpatocka redhat com>]

On Wed, 30 Nov 2011, Alasdair G Kergon wrote:

> On Wed, Nov 30, 2011 at 01:33:32PM +0000, Alasdair G Kergon wrote:
> > Have I missed something in this
> > reasoning, Mikulas?
>  
> Ah - counter-example: mmap?
> So sync might indeed be required to block on the filesystem iff there
> are newly-dirtied pages.
> 
> Alasdair

On non-journaled filesystem, both write and mmap can create dirty pages 
when suspended.

On ext4 I actually tested mmap, but it blocks any writes to mmaped pages 
while suspended.

Mikulas