Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965094AbXBTQGb (ORCPT ); Tue, 20 Feb 2007 11:06:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965292AbXBTQGb (ORCPT ); Tue, 20 Feb 2007 11:06:31 -0500 Received: from kanga.kvack.org ([66.96.29.28]:45331 "EHLO kanga.kvack.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965094AbXBTQGa (ORCPT ); Tue, 20 Feb 2007 11:06:30 -0500 Date: Tue, 20 Feb 2007 11:06:15 -0500 From: Benjamin LaHaise To: Trond Myklebust Cc: Chris Mason , "Ananiev, Leonid I" , Zach Brown , linux-aio@kvack.org, linux-kernel@vger.kernel.org, Suparna bhattacharya , Andrew Morton Subject: Re: [PATCH] aio: propogate post-EIOCBQUEUED errors to completion event Message-ID: <20070220160615.GT31205@kvack.org> References: <20070219203527.20419.68418.sendpatchset@tetsuo.zabbo.net> <20070219215048.GI6133@think.oraclecorp.com> <20070220002109.GG31205@kvack.org> <1171987310.6271.23.camel@heimdal.trondhjem.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1171987310.6271.23.camel@heimdal.trondhjem.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1095 Lines: 25 On Tue, Feb 20, 2007 at 11:01:50AM -0500, Trond Myklebust wrote: > We don't try to resolve "conflicting" writes between ordinary mmap() and > write(), so why should we be doing it for mmap and O_DIRECT? Yes we do -- both writes will succeed. More importantly, if one modifies the first 512 bytes of a page and the other modifies the last 512 bytes of the page, both writes will show up in the completed result. This is not the case with the -EIO bailout. > mmap() is designed to violate the ordinary mutex locks for write(), so > if a conflict arises, whether it be with O_DIRECT or ordinary writes > then it is a case of "last writer wins". Except that we're not handling cases like the one mentioned above, which is quite broken. -ben -- "Time is of no importance, Mr. President, only life is important." Don't Email: . - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/