From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B15FBC352BE for ; Thu, 16 Apr 2020 16:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BDD520857 for ; Thu, 16 Apr 2020 16:27:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="qSarJALw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2410799AbgDPQ1e (ORCPT ); Thu, 16 Apr 2020 12:27:34 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:60586 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387476AbgDPQ1Y (ORCPT ); Thu, 16 Apr 2020 12:27:24 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03GGHo2F164990; Thu, 16 Apr 2020 16:27:10 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=RdmCKsuZa668Ir+vRQIToVm1nsOndtntxoV1kjH984o=; b=qSarJALwHWVs8pgq4IKohUJaQKca/21QyTJH7FV86xDoNnWBv8f6XVG/94fyEFyuqIPT ynI/vWJ27r7vyG6ZC6C1+D4bkcv9ReNaaHkiBY874iEHUMsyV4M8Mid8JF2Lr576FZxR aJVLKNAkMuFCcwdJiUPu6dypLY73zwH4eDXPIz1+DePz0clV/T4WFV423IskNCQGEbJM /qI1Se99DYSWADw4q+wuA5yXzHG3KJfcthU5fArUb6Vv7p0gPdxG/VPhFIAfhkLP+0IP AVrzdfzigSMAo4G1T92Otvg3XGPwH5w9Y8V5S/Lb4bk3J9c333MPYnsADLcebSe1O8WF Og== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2130.oracle.com with ESMTP id 30e0aa81ed-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Apr 2020 16:27:10 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 03GGH5gj032632; Thu, 16 Apr 2020 16:25:10 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 30emendjrr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 16 Apr 2020 16:25:10 +0000 Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 03GGP6AQ015102; Thu, 16 Apr 2020 16:25:06 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 16 Apr 2020 09:25:06 -0700 Date: Thu, 16 Apr 2020 09:25:04 -0700 From: "Darrick J. Wong" To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, Jan Kara , Dan Williams , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jeff Moyer , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH RFC 4/8] fs/ext4: Introduce DAX inode flag Message-ID: <20200416162504.GB6733@magnolia> References: <20200414040030.1802884-1-ira.weiny@intel.com> <20200414040030.1802884-5-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414040030.1802884-5-ira.weiny@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9593 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxscore=0 suspectscore=1 mlxlogscore=999 phishscore=0 spamscore=0 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004160115 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9593 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 clxscore=1015 impostorscore=0 mlxlogscore=999 mlxscore=0 lowpriorityscore=0 suspectscore=1 adultscore=0 spamscore=0 malwarescore=0 phishscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2003020000 definitions=main-2004160115 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 13, 2020 at 09:00:26PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny > > Add a flag to preserve FS_XFLAG_DAX in the ext4 inode. > > Set the flag to be user visible and changeable. Set the flag to be > inherited. Allow applications to change the flag at any time. > > Finally, on regular files, flag the inode to not be cached to facilitate > changing S_DAX on the next creation of the inode. > > Signed-off-by: Ira Weiny > --- > fs/ext4/ext4.h | 13 +++++++++---- > fs/ext4/ioctl.c | 21 ++++++++++++++++++++- > 2 files changed, 29 insertions(+), 5 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 61b37a052052..434021fcec88 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -415,13 +415,16 @@ struct flex_groups { > #define EXT4_VERITY_FL 0x00100000 /* Verity protected inode */ > #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */ > #define EXT4_EOFBLOCKS_FL 0x00400000 /* Blocks allocated beyond EOF */ > + > +#define EXT4_DAX_FL 0x00800000 /* Inode is DAX */ Sooo, fun fact about ext4 vs. the world-- The GETFLAGS/SETFLAGS ioctl, since it came from ext2, shares the same flag values as the ondisk inode flags in ext*. Therefore, each of these EXT4_[whatever]_FL values are supposed to have a FS_[whatever]_FL equivalent in include/uapi/linux/fs.h. (Note that the "[whatever]" is a straight translation since the same uapi header also defines the FS_XFLAG_[xfswhatever] flag values; ignore those.) Evidently, FS_NOCOW_FL already took 0x800000, but ext4.h was never updated to note that the value was taken. I think Ted might be inclined to reserve the ondisk inode bit just in case ext4 ever does support copy on write, though that's his call. :) Long story short - can you use 0x1000000 for this instead, and add the corresponding value to the uapi fs.h? I guess that also means that we can change FS_XFLAG_DAX (in the form of FS_DAX_FL in FSSETFLAGS) after that. --D > + > #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */ > #define EXT4_PROJINHERIT_FL 0x20000000 /* Create with parents projid */ > #define EXT4_CASEFOLD_FL 0x40000000 /* Casefolded file */ > #define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */ > > -#define EXT4_FL_USER_VISIBLE 0x705BDFFF /* User visible flags */ > -#define EXT4_FL_USER_MODIFIABLE 0x604BC0FF /* User modifiable flags */ > +#define EXT4_FL_USER_VISIBLE 0x70DBDFFF /* User visible flags */ > +#define EXT4_FL_USER_MODIFIABLE 0x60CBC0FF /* User modifiable flags */ > > /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */ > #define EXT4_FL_XFLAG_VISIBLE (EXT4_SYNC_FL | \ > @@ -429,14 +432,16 @@ struct flex_groups { > EXT4_APPEND_FL | \ > EXT4_NODUMP_FL | \ > EXT4_NOATIME_FL | \ > - EXT4_PROJINHERIT_FL) > + EXT4_PROJINHERIT_FL | \ > + EXT4_DAX_FL) > > /* Flags that should be inherited by new inodes from their parent. */ > #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\ > EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\ > EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\ > EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\ > - EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL) > + EXT4_PROJINHERIT_FL | EXT4_CASEFOLD_FL |\ > + EXT4_DAX_FL) > > /* Flags that are appropriate for regular files (all but dir-specific ones). */ > #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL | EXT4_CASEFOLD_FL |\ > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > index ee3401a32e79..ca07d5086f03 100644 > --- a/fs/ext4/ioctl.c > +++ b/fs/ext4/ioctl.c > @@ -539,12 +539,15 @@ static inline __u32 ext4_iflags_to_xflags(unsigned long iflags) > xflags |= FS_XFLAG_NOATIME; > if (iflags & EXT4_PROJINHERIT_FL) > xflags |= FS_XFLAG_PROJINHERIT; > + if (iflags & EXT4_DAX_FL) > + xflags |= FS_XFLAG_DAX; > return xflags; > } > > #define EXT4_SUPPORTED_FS_XFLAGS (FS_XFLAG_SYNC | FS_XFLAG_IMMUTABLE | \ > FS_XFLAG_APPEND | FS_XFLAG_NODUMP | \ > - FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT) > + FS_XFLAG_NOATIME | FS_XFLAG_PROJINHERIT | \ > + FS_XFLAG_DAX) > > /* Transfer xflags flags to internal */ > static inline unsigned long ext4_xflags_to_iflags(__u32 xflags) > @@ -563,6 +566,8 @@ static inline unsigned long ext4_xflags_to_iflags(__u32 xflags) > iflags |= EXT4_NOATIME_FL; > if (xflags & FS_XFLAG_PROJINHERIT) > iflags |= EXT4_PROJINHERIT_FL; > + if (xflags & FS_XFLAG_DAX) > + iflags |= EXT4_DAX_FL; > > return iflags; > } > @@ -813,6 +818,17 @@ static int ext4_ioctl_get_es_cache(struct file *filp, unsigned long arg) > return error; > } > > +static void ext4_dax_dontcache(struct inode *inode, unsigned int flags) > +{ > + struct ext4_inode_info *ei = EXT4_I(inode); > + > + if (S_ISDIR(inode->i_mode)) > + return; > + > + if ((ei->i_flags ^ flags) == EXT4_DAX_FL) > + inode->i_state |= I_DONTCACHE; > +} > + > long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > { > struct inode *inode = file_inode(filp); > @@ -1273,6 +1289,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) > return err; > > inode_lock(inode); > + > + ext4_dax_dontcache(inode, flags); > + > ext4_fill_fsxattr(inode, &old_fa); > err = vfs_ioc_fssetxattr_check(inode, &old_fa, &fa); > if (err) > -- > 2.25.1 >