Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765175AbXJOQjI (ORCPT ); Mon, 15 Oct 2007 12:39:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759689AbXJOQi4 (ORCPT ); Mon, 15 Oct 2007 12:38:56 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:56620 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757935AbXJOQiz (ORCPT ); Mon, 15 Oct 2007 12:38:55 -0400 Subject: Re: nfs mmap adventure (was: 2.6.23-mm1) From: Peter Zijlstra To: Trond Myklebust Cc: David Howells , Andrew Morton , linux-kernel@vger.kernel.org, Nick Piggin In-Reply-To: <1192463489.7529.11.camel@heimdal.trondhjem.org> References: <1192451324.27435.71.camel@twins> <20071011213126.cf92efb7.akpm@linux-foundation.org> <21859.1192457172@redhat.com> <1192463489.7529.11.camel@heimdal.trondhjem.org> Content-Type: text/plain Date: Mon, 15 Oct 2007 18:38:34 +0200 Message-Id: <1192466314.27435.84.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.10.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1538 Lines: 40 On Mon, 2007-10-15 at 11:51 -0400, Trond Myklebust wrote: > On Mon, 2007-10-15 at 15:06 +0100, David Howells wrote: > > Peter Zijlstra wrote: > > > > > I get funny SIGBUS' like so: > > > > > > fault > > > if (->page_mkwrite() < 0) > > > nfs_vm_page_mkwrite() > > > nfs_write_begin() > > > nfs_flush_incompatible() > > > nfs_wb_page() > > > nfs_wb_page_priority() > > > nfs_sync_mapping_wait() > > > nfs_wait_on_request_locked() > > > nfs_wait_on_request() > > > nfs_wait_bit_interruptible() > > > return -ERESTARTSYS > > > SIGBUS > > > > > > trying to figure out what to do about this... > > > > > > > Hmmm... It sounds like the fault handler should deliver the appropriate > > signal, should ->page_mkwrite() return ERESTARTSYS, and then retry the access > > instruction that caused the fault when the signal handler has finished > > running. > > If you signal the process before msync() has completed, or before you > have completed unmapping the region then your writes can potentially be > lost. Why should we be providing any guarantees beyond that? Good point, I'm trying to figure out where my signal is comming from. - 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/