From patchwork Fri Aug 17 15:30:14 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Liu Bo X-Patchwork-Id: 1339011 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 89315DF266 for ; Fri, 17 Aug 2012 15:30:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932273Ab2HQPak (ORCPT ); Fri, 17 Aug 2012 11:30:40 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:50269 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932207Ab2HQPaj (ORCPT ); Fri, 17 Aug 2012 11:30:39 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by rcsinet15.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id q7HFUSsn001430 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 17 Aug 2012 15:30:28 GMT Received: from acsmt358.oracle.com (acsmt358.oracle.com [141.146.40.158]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id q7HFUMxs021557 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 17 Aug 2012 15:30:25 GMT Received: from abhmt113.oracle.com (abhmt113.oracle.com [141.146.116.65]) by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id q7HFULNG005720; Fri, 17 Aug 2012 10:30:21 -0500 Received: from [192.168.1.102] (/222.90.165.119) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 17 Aug 2012 08:30:21 -0700 Message-ID: <502E6386.700@oracle.com> Date: Fri, 17 Aug 2012 23:30:14 +0800 From: Liu Bo User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: David Sterba CC: =?ISO-8859-1?Q?Llu=EDs_Batlle_i_Rossell?= , Btrfs mailing list , andrei.popa@i-neo.ro Subject: Re: References: <20120815101229.GH25996@vicerveza.homeunix.net> <502DA230.6010202@oracle.com> <20120817145940.GI17430@twin.jikos.cz> In-Reply-To: <20120817145940.GI17430@twin.jikos.cz> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 08/17/2012 10:59 PM, David Sterba wrote: > On Fri, Aug 17, 2012 at 09:45:20AM +0800, Liu Bo wrote: >> On 08/15/2012 06:12 PM, Lluís Batlle i Rossell wrote: >>> some time ago we discussed on #btrfs that the nocow attribute for files wasn't >>> working (around 3.3 or 3.4 kernels). That was evident by files fragmenting even >>> with the attribute set. >>> >>> Chris mentioned to find a fix quickly for that, and posted some lines of change >>> into irc. But recently someone mentioned that 3.6-rc looks like still not >>> respecting nocow for files. >>> >>> Is there really a fix upstream for that? Do nocow attribute on files work for >>> anyone already? >>> >> >> Dave had post a patch to fix it but only enabling NOCOW with zero sized file. >> >> FYI, the patch is http://article.gmane.org/gmane.comp.file-systems.btrfs/17351 >> >> With the patch, you don't need to mount with nodatacow any more :) >> >> And why it is only for only zero sized file: >> http://permalink.gmane.org/gmane.comp.file-systems.btrfs/18046 > > the original patch http://permalink.gmane.org/gmane.comp.file-systems.btrfs/18031 > did two things, the reasoning why it is not allowed to set nodatasum in > general applies only to the second hunk but this > > @@ -139,7 +139,7 @@ void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) > } > > if (flags & BTRFS_INODE_NODATACOW) > - BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; > + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | BTRFS_INODE_NODATASUM; > > btrfs_update_iflags(inode); > } > --- > > is sufficient to create nocow files via a directory with NOCOW attribute > set, and all new files will inherit it (they are automatically > zero-sized so it's safe). This usecase is similar to setting the > COMPRESS attribute on a directory and all new files will inherit the > flag. > > If Andrei wants to resend just this particular hunk, I'm giving it my ACK. > IMO the following is better, just make use of the original check. If you agree with this, I'll send it as a patch :) > > david > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > --- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6e8f416..d4e58df 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4721,8 +4721,10 @@ static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, if (btrfs_test_opt(root, NODATASUM)) BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; if (btrfs_test_opt(root, NODATACOW) || - (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW)) + (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW)) { BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; + } } insert_inode_hash(inode);