Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751207AbXJVUss (ORCPT ); Mon, 22 Oct 2007 16:48:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751088AbXJVUsj (ORCPT ); Mon, 22 Oct 2007 16:48:39 -0400 Received: from rv-out-0910.google.com ([209.85.198.189]:18594 "EHLO rv-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751217AbXJVUsi (ORCPT ); Mon, 22 Oct 2007 16:48:38 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=JBzVh9rSSw6H71OX4TK4F9nf2Ybm3/YkH73CCcKtbK8n+HtORpc3Jc55ncV1OpdbRjxxOQKFVVTfwpk3v8BWdmJeq9Zb5E8k+iQ2349DkNfNUVsvJAzkmOij6enMe+rs2Wg+nYIQpLLkXrReebT8FM4ahVqoF3Uh0apckX0j4Tk= Message-ID: <84144f020710221348x297795c0qda61046ec69a7178@mail.gmail.com> Date: Mon, 22 Oct 2007 23:48:37 +0300 From: "Pekka Enberg" To: "Hugh Dickins" Subject: Re: msync(2) bug(?), returns AOP_WRITEPAGE_ACTIVATE to userland Cc: "Erez Zadok" , "Ryan Finnie" , "Andrew Morton" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, cjwatson@ubuntu.com, linux-mm@kvack.org, neilb@suse.de In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200710142232.l9EMW8kK029572@agora.fsl.cs.sunysb.edu> <84144f020710150447o94b1babo8b6e6a647828465f@mail.gmail.com> X-Google-Sender-Auth: 6efe49e322c0f98c Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1217 Lines: 27 Hi Hugh, On Mon, 15 Oct 2007, Pekka Enberg wrote: > > I wonder whether _not setting_ BDI_CAP_NO_WRITEBACK implies that > > ->writepage() will never return AOP_WRITEPAGE_ACTIVATE for > > !wbc->for_reclaim case which would explain why we haven't hit this bug > > before. Hugh, Andrew? On 10/22/07, Hugh Dickins wrote: > Only ramdisk and shmem have been returning AOP_WRITEPAGE_ACTIVATE. > Both of those set BDI_CAP_NO_WRITEBACK. ramdisk never returned it > if !wbc->for_reclaim. I contend that shmem shouldn't either: it's > a special code to get the LRU rotation right, not useful elsewhere. > Though Documentation/filesystems/vfs.txt does imply wider use. > > I think this is where people use the phrase "go figure" ;) Heh. As far as I can tell, the implication of "wider use" was added by Neil in commit "341546f5ad6fce584531f744853a5807a140f2a9 Update some VFS documentation", so perhaps he might know? Neil? Pekka - 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/