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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 0845EC2BA2B for ; Thu, 16 Apr 2020 22:33:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C86F92078B for ; Thu, 16 Apr 2020 22:33:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729093AbgDPWda (ORCPT ); Thu, 16 Apr 2020 18:33:30 -0400 Received: from mga04.intel.com ([192.55.52.120]:7694 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725768AbgDPWd3 (ORCPT ); Thu, 16 Apr 2020 18:33:29 -0400 IronPort-SDR: aNum4qSW63qL0ApQGG1zl4gUL/+VxRBooKDVqjjq19n3RSYs7nfRMXiVbkPtXwC5WkhXBxTcDx GTJXM21JEZKw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2020 15:33:28 -0700 IronPort-SDR: 9HpPHnHF9xKXWxCXL8RYLwPBJDDcKekcWmdTV+0SUNRn7YA/ysAZeNNoZ4fWdk5TSwbZQQcMMT pqYMruz0LS6w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,392,1580803200"; d="scan'208";a="257380105" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by orsmga006.jf.intel.com with ESMTP; 16 Apr 2020 15:33:28 -0700 Date: Thu, 16 Apr 2020 15:33:27 -0700 From: Ira Weiny To: "Darrick J. Wong" 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: <20200416223327.GO2309605@iweiny-DESK2.sc.intel.com> References: <20200414040030.1802884-1-ira.weiny@intel.com> <20200414040030.1802884-5-ira.weiny@intel.com> <20200416162504.GB6733@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200416162504.GB6733@magnolia> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 16, 2020 at 09:25:04AM -0700, Darrick J. Wong wrote: > 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. Interesting... > > (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. :) Seems like I should change this... And I did not realize I was inherently changing a bit definition which was exposed to other FS's... > > 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. :-/ Are there any potential users of FS_XFLAG_DAX now? >From what it looks like, changing FS_XFLAG_DAX to FS_DAX_FL would be pretty straight forward. Just to be sure, looks like XFS converts the FS_[xxx]_FL to FS_XFLAGS_[xxx] in xfs_merge_ioc_xflags()? But it does not look like all the FS_[xxx]_FL flags are converted. Is is that XFS does not support those options? Or is it depending on the VFS layer for some of them? Ira > > --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 > >