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=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 419E0C3B187 for ; Tue, 11 Feb 2020 05:47:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 29DAB2082F for ; Tue, 11 Feb 2020 05:47:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728070AbgBKFrx (ORCPT ); Tue, 11 Feb 2020 00:47:53 -0500 Received: from mail105.syd.optusnet.com.au ([211.29.132.249]:44791 "EHLO mail105.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727594AbgBKFrx (ORCPT ); Tue, 11 Feb 2020 00:47:53 -0500 Received: from dread.disaster.area (pa49-179-138-28.pa.nsw.optusnet.com.au [49.179.138.28]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id 8AB503A353F; Tue, 11 Feb 2020 16:47:49 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1j1OOi-0005zL-VL; Tue, 11 Feb 2020 16:47:48 +1100 Date: Tue, 11 Feb 2020 16:47:48 +1100 From: Dave Chinner To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, Alexander Viro , "Darrick J. Wong" , Dan Williams , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v3 03/12] fs/xfs: Separate functionality of xfs_inode_supports_dax() Message-ID: <20200211054748.GF10776@dread.disaster.area> References: <20200208193445.27421-1-ira.weiny@intel.com> <20200208193445.27421-4-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200208193445.27421-4-ira.weiny@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=W5xGqiek c=1 sm=1 tr=0 a=zAxSp4fFY/GQY8/esVNjqw==:117 a=zAxSp4fFY/GQY8/esVNjqw==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=l697ptgUJYAA:10 a=QyXUC8HyAAAA:8 a=7-415B0cAAAA:8 a=Yrr-Swfh6q8XfX9a3mMA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Sat, Feb 08, 2020 at 11:34:36AM -0800, ira.weiny@intel.com wrote: > From: Ira Weiny > > xfs_inode_supports_dax() should reflect if the inode can support DAX not > that it is enabled for DAX. Leave that to other helper functions. > > Change the caller of xfs_inode_supports_dax() to call > xfs_inode_use_dax() which reflects new logic to override the effective > DAX flag with either the mount option or the physical DAX flag. > > To make the logic clear create 2 helper functions for the mount and > physical flag. > > Signed-off-by: Ira Weiny > --- > fs/xfs/xfs_iops.c | 32 ++++++++++++++++++++++++++------ > 1 file changed, 26 insertions(+), 6 deletions(-) > > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > index 81f2f93caec0..a7db50d923d4 100644 > --- a/fs/xfs/xfs_iops.c > +++ b/fs/xfs/xfs_iops.c > @@ -1236,6 +1236,15 @@ static const struct inode_operations xfs_inline_symlink_inode_operations = { > .update_time = xfs_vn_update_time, > }; > > +static bool > +xfs_inode_mount_is_dax( > + struct xfs_inode *ip) > +{ > + struct xfs_mount *mp = ip->i_mount; > + > + return (mp->m_flags & XFS_MOUNT_DAX) == XFS_MOUNT_DAX; > +} > + > /* Figure out if this file actually supports DAX. */ > static bool > xfs_inode_supports_dax( > @@ -1247,11 +1256,6 @@ xfs_inode_supports_dax( > if (!S_ISREG(VFS_I(ip)->i_mode) || xfs_is_reflink_inode(ip)) > return false; > > - /* DAX mount option or DAX iflag must be set. */ > - if (!(mp->m_flags & XFS_MOUNT_DAX) && > - !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)) > - return false; > - > /* Block size must match page size */ > if (mp->m_sb.sb_blocksize != PAGE_SIZE) > return false; > @@ -1260,6 +1264,22 @@ xfs_inode_supports_dax( > return xfs_inode_buftarg(ip)->bt_daxdev != NULL; > } > > +static bool > +xfs_inode_is_dax( > + struct xfs_inode *ip) > +{ > + return (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) == XFS_DIFLAG2_DAX; > +} I don't think these wrappers add any value at all - the naming of them is entirely confusing, too. e.g. "inode is dax" doesn't tell me that it is checking the on disk flags - it doesn't tell me how it is different to IS_DAX, or why I'd use one versus the other. And then xfs_inode_mount_is_dax() is just... worse. Naming is hard. :) > + > +static bool > +xfs_inode_use_dax( > + struct xfs_inode *ip) > +{ > + return xfs_inode_supports_dax(ip) && > + (xfs_inode_mount_is_dax(ip) || > + xfs_inode_is_dax(ip)); > +} Urk. Naming - we're not "using dax" here, we are checkign to see if we should enable DAX on this inode. IOWs: static bool xfs_inode_enable_dax( struct xfs_inode *ip) { if (!xfs_inode_supports_dax(ip)) return false; if (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX) return true; if (ip->i_mount->m_flags & XFS_MOUNT_DAX) return true; return false; } Cheers, Dave. -- Dave Chinner david@fromorbit.com