From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Subject: Re: [FYI] tux3: Core changes
Date: Tue, 26 May 2015 19:22:39 +0900
Message-ID: <20150526102239.GA466@swordfish>
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Cc: Jan Kara <jack@suse.cz>, David Lang <david@lang.hm>,
	Rik van Riel <riel@redhat.com>,
	linux-fsdevel@vger.kernel.org, tux3@tux3.org,
	linux-kernel@vger.kernel.org,
	OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Daniel Phillips <daniel@phunq.net>
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On (05/26/15 01:08), Daniel Phillips wrote:
> On Tuesday, May 26, 2015 12:09:10 AM PDT, Jan Kara wrote:
> >  E.g. video drivers (or infiniband or direct IO for that matter) which
> >have buffers in user memory (may be mmapped file), grab references to pages
> >and hand out PFNs of those pages to the hardware to store data in them...
> >If you fork a page after the driver has handed PFNs to the hardware, you've
> >just lost all the writes hardware will do.
> 
> Hi Jan,
> 
> The page forked because somebody wrote to it with write(2) or mmap write at
> the same time as a video driver (or infiniband or direct IO) was doing io to
> it. Isn't the application trying hard to lose data in that case? It would
> not need page fork to lose data that way.
> 

Hello,

is it possible to page-fork-bomb the system by some 'malicious' app?

	-ss