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=-16.4 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 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 EB83EC47087 for ; Wed, 26 May 2021 00:31:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C893F61417 for ; Wed, 26 May 2021 00:31:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232439AbhEZAcy (ORCPT ); Tue, 25 May 2021 20:32:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:48096 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232290AbhEZAcr (ORCPT ); Tue, 25 May 2021 20:32:47 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C4DD61417; Wed, 26 May 2021 00:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1621989076; bh=rS46CPL5f/bRkO3BMaBiDsChhnXIQ5enJBn3cWJSARI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EYB84DlrjLbIs+294Q2BHQTtfWQRKXf12JBKt3fQ7TQe/ngCPuxG8bq1AXIC8GFBW 164RokZrn8F2UaWo3cfJy6ODnx1A6xjqs9aP61EGhdJB4lrQ0H+LHDp4picjDqVNF6 eHNc38JvQ7+pVmbA+L/KbPR+v1N2VY+bE7DO1bqNR7dyUHjJPhVTK7RfGVv01SINOE RQSoHwH5p+J8F+Dm4+60c30NdmypCBr4x2s4EZ7hAafoGIfRsxbfJ6b/VC2yErIvUZ DS/D4Z02jdflaIRX/u2c/AW69aMYHhBebjs9tCnry30cMoRZY1G6P5kI6Mc5tK8upN B+JpymCMsUtMA== Date: Tue, 25 May 2021 17:31:16 -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, jack@suse.cz Subject: Re: [PATCH v6 7/7] fs/xfs: Add dax dedupe support Message-ID: <20210526003116.GU202121@locust> References: <20210519060045.1051226-1-ruansy.fnst@fujitsu.com> <20210519060045.1051226-8-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210519060045.1051226-8-ruansy.fnst@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 19, 2021 at 02:00:45PM +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 | 57 ++++++++++++++++++++++++++++++++++++++++++++ > fs/xfs/xfs_inode.h | 1 + > fs/xfs/xfs_reflink.c | 4 ++-- > 4 files changed, 61 insertions(+), 3 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..d5e2791969ba 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -3711,6 +3711,59 @@ xfs_iolock_two_inodes_and_break_layout( > return 0; > } > > +static int > +xfs_mmaplock_two_inodes_and_break_dax_layout( > + struct xfs_inode *ip1, > + struct xfs_inode *ip2) > +{ > + int error, attempts = 0; > + bool retry; > + struct page *page; > + struct xfs_log_item *lp; > + > + if (ip1->i_ino > ip2->i_ino) > + swap(ip1, ip2); If Jan Kara [added to cc] succeeds in hoisting the MMAPLOCK to struct address space then this is going to have to change to: if (VFS_I(ip1)->i_mapping > VFS_I(ip2)->i_mapping) swap(ip1, ip2); For now this is ok. > + > +again: > + retry = false; > + /* Lock the first inode */ > + xfs_ilock(ip1, XFS_MMAPLOCK_EXCL); > + error = xfs_break_dax_layouts(VFS_I(ip1), &retry); > + if (error || retry) { > + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); > + goto again; > + } > + > + if (ip1 == ip2) > + return 0; > + > + /* Nested lock the second inode */ > + lp = &ip1->i_itemp->ili_item; > + if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) { > + if (!xfs_ilock_nowait(ip2, > + xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) { > + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); > + if ((++attempts % 5) == 0) > + delay(1); /* Don't just spin the CPU */ > + goto again; > + } > + } else > + xfs_ilock(ip2, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1)); I wonder if this chunk is really necessary considering that the AIL never touches the MMAPLOCK/i_mapping invalidation lock? I guess it doesn't really hurt anything since that's what the code does now. Reviewed-by: Darrick J. Wong --D > + /* > + * 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(VFS_I(ip2)->i_mapping); > + if (page && page_ref_count(page) != 1) { > + xfs_iunlock(ip2, XFS_MMAPLOCK_EXCL); > + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL); > + goto again; > + } > + > + return 0; > +} > + > /* > * Lock two inodes so that userspace cannot initiate I/O via file syscalls or > * mmap activity. > @@ -3725,6 +3778,10 @@ xfs_ilock2_io_mmap( > ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2)); > if (ret) > return ret; > + > + if (IS_DAX(VFS_I(ip1)) && IS_DAX(VFS_I(ip2))) > + return xfs_mmaplock_two_inodes_and_break_dax_layout(ip1, ip2); > + > 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 > > >