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 15C0CC55186 for ; Tue, 21 Apr 2020 21:43:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0016820656 for ; Tue, 21 Apr 2020 21:43:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726124AbgDUVna (ORCPT ); Tue, 21 Apr 2020 17:43:30 -0400 Received: from mga05.intel.com ([192.55.52.43]:3426 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbgDUVna (ORCPT ); Tue, 21 Apr 2020 17:43:30 -0400 IronPort-SDR: 7P8WNAcWUyj0aQ3Xi9OK9W1KZ9ggHx/r4D4g3kNIXe7tb1Jh77NDsEDZsyKWLMXtViP+DAeqfF Vpfe0R5UHuDw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2020 14:43:29 -0700 IronPort-SDR: l9v2emWz69/KRu2nwYAzuWNK6yG8VzlTGptMSXs336pBbWT0m/0+nvmKP3w1ZyAH2wx8R3haKM 7VHY+96vMIrA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="279792039" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by fmsmga004.fm.intel.com with ESMTP; 21 Apr 2020 14:43:29 -0700 Date: Tue, 21 Apr 2020 14:43:29 -0700 From: Ira Weiny To: Dave Chinner Cc: "Darrick J. Wong" , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, Al Viro , Jan Kara , Dan Williams , Christoph Hellwig , "Theodore Y. Ts'o" , Jeff Moyer , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH V9 10/11] fs/xfs: Update xfs_ioctl_setattr_dax_invalidate() Message-ID: <20200421214328.GD3372712@iweiny-DESK2.sc.intel.com> References: <20200421191754.3372370-1-ira.weiny@intel.com> <20200421191754.3372370-11-ira.weiny@intel.com> <20200421203140.GD6742@magnolia> <20200421213049.GC27860@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200421213049.GC27860@dread.disaster.area> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Wed, Apr 22, 2020 at 07:30:49AM +1000, Dave Chinner wrote: > On Tue, Apr 21, 2020 at 01:31:40PM -0700, Darrick J. Wong wrote: > > On Tue, Apr 21, 2020 at 12:17:52PM -0700, ira.weiny@intel.com wrote: > > > From: Ira Weiny > > > > > > Because of the separation of FS_XFLAG_DAX from S_DAX and the delayed > > > setting of S_DAX, data invalidation no longer needs to happen when > > > FS_XFLAG_DAX is changed. > > > > > > Change xfs_ioctl_setattr_dax_invalidate() to be > > > xfs_ioctl_dax_check_set_cache() and alter the code to reflect the new > > > functionality. > > > > > > Furthermore, we no longer need the locking so we remove the join_flags > > > logic. > > > > > > Signed-off-by: Ira Weiny > > > > > > --- > > > Changes from V8: > > > Change name of function to xfs_ioctl_dax_check_set_cache() > > > Update commit message > > > Fix bit manipulations > > > > > > Changes from V7: > > > Use new flag_inode_dontcache() > > > Skip don't cache if mount over ride is active. > > > > > > Changes from v6: > > > Fix completely broken implementation and update commit message. > > > Use the new VFS layer I_DONTCACHE to facilitate inode eviction > > > and S_DAX changing on drop_caches > > > > > > Changes from v5: > > > New patch > > > --- > > > fs/xfs/xfs_ioctl.c | 108 +++++++++------------------------------------ > > > 1 file changed, 20 insertions(+), 88 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > > > index 104495ac187c..b87b571a6748 100644 > > > --- a/fs/xfs/xfs_ioctl.c > > > +++ b/fs/xfs/xfs_ioctl.c > > > @@ -1245,64 +1245,26 @@ xfs_ioctl_setattr_xflags( > > > return 0; > > > } > > > > > > -/* > > > - * If we are changing DAX flags, we have to ensure the file is clean and any > > > - * cached objects in the address space are invalidated and removed. This > > > - * requires us to lock out other IO and page faults similar to a truncate > > > - * operation. The locks need to be held until the transaction has been committed > > > - * so that the cache invalidation is atomic with respect to the DAX flag > > > - * manipulation. > > > - */ > > > -static int > > > -xfs_ioctl_setattr_dax_invalidate( > > > +static void > > > +xfs_ioctl_dax_check_set_cache( > > > > That's a ... strange name. Set cache on what? > > > > Oh, this is the function that sets I_DONTCACHE if an FS_XFLAG_DAX change > > could have an immediate effect on S_DAX (assuming no other users). What > > do you think of the following? > > > > /* > > * If a change to FS_XFLAG_DAX will result in an change to S_DAX > > * the next time the incore inode is initialized, set the VFS > > * I_DONTCACHE flag to try to hurry that along. > > */ > > static void > > xfs_ioctl_try_change_vfs_dax(...) > > That doesn't seem any better. This is a preparation function now, in > that it can't fail and doesn't change the outcome of the operation > being performed. So, IMO, calling it something like > xfs_ioctl_setattr_prepare_dax() would be a better name for it. But it does potentially (after a check) set I_DONTCACHE. What about? xfs_ioctl_dax_check_set_dontcache()? Ira > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com