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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 1E567C11D0C for ; Thu, 20 Feb 2020 16:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE64720801 for ; Thu, 20 Feb 2020 16:50:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728646AbgBTQuC (ORCPT ); Thu, 20 Feb 2020 11:50:02 -0500 Received: from mga17.intel.com ([192.55.52.151]:1257 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727868AbgBTQuC (ORCPT ); Thu, 20 Feb 2020 11:50:02 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Feb 2020 08:50:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,465,1574150400"; d="scan'208";a="236298537" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by orsmga003.jf.intel.com with ESMTP; 20 Feb 2020 08:49:57 -0800 Date: Thu, 20 Feb 2020 08:49:57 -0800 From: Ira Weiny To: "Darrick J. Wong" Cc: Jeff Moyer , Dan Williams , Linux Kernel Mailing List , Alexander Viro , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4 , linux-xfs , linux-fsdevel Subject: Re: [PATCH v3 00/12] Enable per-file/directory DAX operations V3 Message-ID: <20200220164957.GB20772@iweiny-DESK2.sc.intel.com> References: <20200214200607.GA18593@iweiny-DESK2.sc.intel.com> <20200214215759.GA20548@iweiny-DESK2.sc.intel.com> <20200218023535.GA14509@iweiny-DESK2.sc.intel.com> <20200218235429.GB14509@iweiny-DESK2.sc.intel.com> <20200220162027.GA20772@iweiny-DESK2.sc.intel.com> <20200220163024.GV9506@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200220163024.GV9506@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, Feb 20, 2020 at 08:30:24AM -0800, Darrick J. Wong wrote: > On Thu, Feb 20, 2020 at 08:20:28AM -0800, Ira Weiny wrote: > > On Tue, Feb 18, 2020 at 03:54:30PM -0800, 'Ira Weiny' wrote: > > > On Tue, Feb 18, 2020 at 09:22:58AM -0500, Jeff Moyer wrote: > > > > Ira Weiny writes: > > > > > If my disassembly of read_pages is correct it looks like readpage is null which > > > > > makes sense because all files should be IS_DAX() == true due to the mount option... > > > > > > > > > > But tracing code indicates that the patch: > > > > > > > > > > fs: remove unneeded IS_DAX() check > > > > > > > > > > ... may be the culprit and the following fix may work... > > > > > > > > > > diff --git a/mm/filemap.c b/mm/filemap.c > > > > > index 3a7863ba51b9..7eaf74a2a39b 100644 > > > > > --- a/mm/filemap.c > > > > > +++ b/mm/filemap.c > > > > > @@ -2257,7 +2257,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) > > > > > if (!count) > > > > > goto out; /* skip atime */ > > > > > > > > > > - if (iocb->ki_flags & IOCB_DIRECT) { > > > > > + if (iocb->ki_flags & IOCB_DIRECT || IS_DAX(inode)) { > > > > > struct file *file = iocb->ki_filp; > > > > > struct address_space *mapping = file->f_mapping; > > > > > struct inode *inode = mapping->host; > > > > > > > > Well, you'll have to up-level the inode variable instantiation, > > > > obviously. That solves this particular issue. > > > > > > Well... This seems to be a random issue. I've had BMC issues with > > > my server most of the day... But even with this patch I still get the failure > > > in read_pages(). :-/ > > > > > > And I have gotten it to both succeed and fail with qemu... :-/ > > > > ... here is the fix. I made the change in xfs_diflags_to_linux() early on with > > out factoring in the flag logic changes we have agreed upon... > > > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > > index 62d9f622bad1..d592949ad396 100644 > > --- a/fs/xfs/xfs_ioctl.c > > +++ b/fs/xfs/xfs_ioctl.c > > @@ -1123,11 +1123,11 @@ xfs_diflags_to_linux( > > inode->i_flags |= S_NOATIME; > > else > > inode->i_flags &= ~S_NOATIME; > > - if (xflags & FS_XFLAG_DAX) > > + > > + if (xfs_inode_enable_dax(ip)) > > inode->i_flags |= S_DAX; > > else > > inode->i_flags &= ~S_DAX; > > - > > } > > > > But the one thing which tripped me up, and concerns me, is we have 2 functions > > which set the inode flags. > > > > xfs_diflags_to_iflags() > > xfs_diflags_to_linux() > > > > xfs_diflags_to_iflags() is geared toward initialization but logically they do > > the same thing. I see no reason to keep them separate. Does anyone? > > > > Based on this find, the discussion on behavior in this thread, and the comments > > from Dave I'm reworking the series because the flag check/set functions have > > all changed and I really want to be as clear as possible with both the patches > > and the resulting code.[*] So v4 should be out today including attempting to > > document what we have discussed here and being as clear as possible on the > > behavior. :-D > > > > Thanks so much for testing this! > > > > Ira > > > > [*] I will probably throw in a patch to remove xfs_diflags_to_iflags() as I > > really don't see a reason to keep it. > > > > I prefer you keep the one in xfs_iops.c since ioctls are a higher level > function than general inode operations. Makes sense. Do you prefer the xfs_diflags_to_iflags() name as well? Ira > > --D