From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ea0-f176.google.com (mail-ea0-f176.google.com [209.85.215.176]) by kanga.kvack.org (Postfix) with ESMTP id 06F716B0031 for ; Mon, 23 Dec 2013 15:26:26 -0500 (EST) Received: by mail-ea0-f176.google.com with SMTP id h14so2522312eaj.35 for ; Mon, 23 Dec 2013 12:26:26 -0800 (PST) Received: from jenni1.inet.fi (mta-out.inet.fi. [195.156.147.13]) by mx.google.com with ESMTP id p9si21845268eew.55.2013.12.23.12.26.26 for ; Mon, 23 Dec 2013 12:26:26 -0800 (PST) Date: Mon, 23 Dec 2013 20:54:33 +0200 From: "Kirill A. Shutemov" Subject: Re: [PATCH v4 21/22] Add support for pmd_faults Message-ID: <20131223185433.GA18067@node.dhcp.inet.fi> References: <20131223134113.GA14806@node.dhcp.inet.fi> <20131223145031.GB11091@parisc-linux.org> <20131223151003.GA15744@node.dhcp.inet.fi> <20131223184222.GE11091@parisc-linux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131223184222.GE11091@parisc-linux.org> Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli On Mon, Dec 23, 2013 at 11:42:22AM -0700, Matthew Wilcox wrote: > > Do you know anyone who relay on SIGBUS for correctness? > > Oh, I remember the real reason now. If we install a PMD that hangs off > the end of the file then by reading past i_size, we can read the blocks of > whatever happens to be in storage after the end of the file, which could > be another file's data. This doesn't happen for the PTE case because the > existing code only works for filesystems with a block size == PAGE_SIZE. I see. It's valid reason. Probably, it's better to add comment there. -- Kirill A. Shutemov -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org