From mboxrd@z Thu Jan  1 00:00:00 1970
From: Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [PATCH] fuse: honour max_read and max_write in direct_io mode
Date: Wed, 24 Sep 2014 20:01:56 +0100
Message-ID: <20140924190156.GF7996@ZenIV.linux.org.uk>
References: <20140924150911.GB7441@tucsk.piliscsaba.szeredi.hu>
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Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
To: Miklos Szeredi <miklos@szeredi.hu>
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On Wed, Sep 24, 2014 at 05:09:11PM +0200, Miklos Szeredi wrote:
> From: Miklos Szeredi <mszeredi@suse.cz>
> 
> The third argument of fuse_get_user_pages() "nbytesp" refers to the number of
> bytes a caller asked to pack into fuse request. This value may be lesser
> than capacity of fuse request or iov_iter.  So fuse_get_user_pages() must
> ensure that *nbytesp won't grow.
> 
> Now, when helper iov_iter_get_pages() performs all hard work of extracting
> pages from iov_iter, it can be done by passing properly calculated
> "maxsize" to the helper.
> 
> The other caller of iov_iter_get_pages() (dio_refill_pages()) doesn't need
> this capability, so pass LONG_MAX as the maxsize argument here.
> 
> Fixes: c9c37e2e6378 ("fuse: switch to iov_iter_get_pages()")
> Reported-by: Werner Baumann <werner.baumann@onlinehome.de>
> Tested-by: Maxim Patlasov <mpatlasov@parallels.com>
> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

Applied, will be in tonight pull request.