From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [patch 2/2] vfs: relax count check in rw_verify_area Date: Thu, 14 Oct 2010 16:30:47 -0700 Message-ID: <20101014163047.d909ad5c.akpm@linux-foundation.org> References: <201010132246.21744.edward.shishkin@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, Eric Sandeen , lmcilroy@redhat.com, LKML To: Edward Shishkin Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:41140 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753004Ab0JNXbc (ORCPT ); Thu, 14 Oct 2010 19:31:32 -0400 In-Reply-To: <201010132246.21744.edward.shishkin@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, 13 Oct 2010 22:46:21 +0200 Edward Shishkin wrote: > Increase count limit in rw_verify_area(). > OK, now this is a truly awful attempt to describe a patch. afaict what the patch does is to change rw_verify_area() so that the kernel now permits single reads and writes of up to 2^63 bytes on 64-bit systems. Whereas it was previously limited to 2^31. And the patch also fixes up a couple of callsites which were assuming that rw_verify_area() had that particular behaviour. But that's just my guess, based on a quick read of the implementation. I didn't check how far this change penetrates. Does it affect all filesystems, for example? If so were they all reviewed (or tested!) for correctness? And why was this patch written? What motivated you? What are the user-visible effects? Do manpages need updating? I don't want to have to sit here scratching my head over the implications and intent of *your* patch. As at least a starting point, you should be telling us, please.