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=-13.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY 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 573F3C433B4 for ; Wed, 12 May 2021 01:04:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 120166192C for ; Wed, 12 May 2021 01:04:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229932AbhELBFk (ORCPT ); Tue, 11 May 2021 21:05:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:54496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229637AbhELBFj (ORCPT ); Tue, 11 May 2021 21:05:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 92DFF6188B; Wed, 12 May 2021 01:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620781471; bh=4ukDiIKKgh1y+mRhe74OIC0185vE18PdqlfDiEBdDE4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HksElAHPqQqPB2hMXEL/asB8GFQXO3cFgF3KADg+VblDPr/PBw4dPekdB21RFxoSJ 5Awaw1RlZivkW7DrIaEee7Ctm/wxfD/BTyXlqhTLHsF6mSqovXt/1rZiv/s9Vq62w3 3Efp0CgDDF5waFLOzD8jmBLv46/LliifFIMNAspqqG5791JL8rsBnFOkUg8efhqMxD pkxMmHCzryjgNtteu5hzHqyqzm1ACsfYCcMcwQ1fqIHGyWcNqL+R5z4nKs9grDuPoL CZ5m0uxIYixuIs41CZ0xcuJBTkXamHs/pU58ime2FvfEtX89szvZdLuu9FTwcx5E8R DAQVLPTmCDdfw== Date: Tue, 11 May 2021 18:04:28 -0700 From: "Darrick J. Wong" To: Shiyang Ruan Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, darrick.wong@oracle.com, dan.j.williams@intel.com, willy@infradead.org, viro@zeniv.linux.org.uk, david@fromorbit.com, hch@lst.de, rgoldwyn@suse.de Subject: Re: [PATCH v5 7/7] fs/xfs: Add dax dedupe support Message-ID: <20210512010428.GQ8582@magnolia> References: <20210511030933.3080921-1-ruansy.fnst@fujitsu.com> <20210511030933.3080921-8-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210511030933.3080921-8-ruansy.fnst@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, May 11, 2021 at 11:09:33AM +0800, Shiyang Ruan wrote: > Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files > who are going to be deduped. After that, call compare range function > only when files are both DAX or not. > > Signed-off-by: Shiyang Ruan > --- > fs/xfs/xfs_file.c | 2 +- > fs/xfs/xfs_inode.c | 66 +++++++++++++++++++++++++++++++++++++++++++- > fs/xfs/xfs_inode.h | 1 + > fs/xfs/xfs_reflink.c | 4 +-- > 4 files changed, 69 insertions(+), 4 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 38d8eca05aee..bd5002d38df4 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -823,7 +823,7 @@ xfs_wait_dax_page( > xfs_ilock(ip, XFS_MMAPLOCK_EXCL); > } > > -static int > +int > xfs_break_dax_layouts( > struct inode *inode, > bool *retry) > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index 0369eb22c1bb..0774b6e2b940 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -3711,6 +3711,64 @@ xfs_iolock_two_inodes_and_break_layout( > return 0; > } > > +static int > +xfs_mmaplock_two_inodes_and_break_dax_layout( > + struct inode *src, > + struct inode *dest) MMAPLOCK is an xfs_inode lock, so please pass those in here. > +{ > + int error, attempts = 0; > + bool retry; > + struct xfs_inode *ip0, *ip1; > + struct page *page; > + struct xfs_log_item *lp; > + > + if (src > dest) > + swap(src, dest); The MMAPLOCK (and ILOCK) locking order is increasing inode number, not the address of the incore object. This is different (and not consistent with) i_rwsem/XFS_IOLOCK, but those are the rules. > + ip0 = XFS_I(src); > + ip1 = XFS_I(dest); > + > +again: > + retry = false; > + /* Lock the first inode */ > + xfs_ilock(ip0, XFS_MMAPLOCK_EXCL); > + error = xfs_break_dax_layouts(src, &retry); > + if (error || retry) { > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL); > + goto again; > + } > + > + if (src == dest) > + return 0; > + > + /* Nested lock the second inode */ > + lp = &ip0->i_itemp->ili_item; > + if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) { > + if (!xfs_ilock_nowait(ip1, > + xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) { > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL); > + if ((++attempts % 5) == 0) > + delay(1); /* Don't just spin the CPU */ > + goto again; > + } > + } else > + xfs_ilock(ip1, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1)); > + /* > + * We cannot use xfs_break_dax_layouts() directly here because it may > + * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable > + * for this nested lock case. > + */ > + page = dax_layout_busy_page(dest->i_mapping); > + if (page) { > + if (page_ref_count(page) != 1) { This could be flattened to: if (page && page_ref_count(page) != 1) { ... } --D > + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL); > + goto again; > + } > + } > + > + return 0; > +} > + > /* > * Lock two inodes so that userspace cannot initiate I/O via file syscalls or > * mmap activity. > @@ -3721,10 +3779,16 @@ xfs_ilock2_io_mmap( > struct xfs_inode *ip2) > { > int ret; > + struct inode *ino1 = VFS_I(ip1); > + struct inode *ino2 = VFS_I(ip2); > > - ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2)); > + ret = xfs_iolock_two_inodes_and_break_layout(ino1, ino2); > if (ret) > return ret; > + > + if (IS_DAX(ino1) && IS_DAX(ino2)) > + return xfs_mmaplock_two_inodes_and_break_dax_layout(ino1, ino2); > + > if (ip1 == ip2) > xfs_ilock(ip1, XFS_MMAPLOCK_EXCL); > else > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h > index ca826cfba91c..2d0b344fb100 100644 > --- a/fs/xfs/xfs_inode.h > +++ b/fs/xfs/xfs_inode.h > @@ -457,6 +457,7 @@ enum xfs_prealloc_flags { > > int xfs_update_prealloc_flags(struct xfs_inode *ip, > enum xfs_prealloc_flags flags); > +int xfs_break_dax_layouts(struct inode *inode, bool *retry); > int xfs_break_layouts(struct inode *inode, uint *iolock, > enum layout_break_reason reason); > > diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c > index 9a780948dbd0..ff308304c5cd 100644 > --- a/fs/xfs/xfs_reflink.c > +++ b/fs/xfs/xfs_reflink.c > @@ -1324,8 +1324,8 @@ xfs_reflink_remap_prep( > if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest)) > goto out_unlock; > > - /* Don't share DAX file data for now. */ > - if (IS_DAX(inode_in) || IS_DAX(inode_out)) > + /* Don't share DAX file data with non-DAX file. */ > + if (IS_DAX(inode_in) != IS_DAX(inode_out)) > goto out_unlock; > > if (!IS_DAX(inode_in)) > -- > 2.31.1 > > >