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=-8.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 E4E55C35641 for ; Sat, 22 Feb 2020 00:31:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE2CE2071E for ; Sat, 22 Feb 2020 00:31:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="iwNLY9wz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727213AbgBVAbW (ORCPT ); Fri, 21 Feb 2020 19:31:22 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:42526 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbgBVAbW (ORCPT ); Fri, 21 Feb 2020 19:31:22 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01M0V6ed179005; Sat, 22 Feb 2020 00:31:12 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=8dG0FXA4wWuKv9M0FiPwAifGFclBlKhCvtoUyeoOwcs=; b=iwNLY9wznf9oHIromlJJqfjEs+fiBdhTQ2FDP25t6xR8Fbb+ISZrOGhfaRt3plwGjuUx qgEoZhYxGJUM3fl/LyAMoeSokg4SxZrDCHLy+zAoCMcAFTEcrxtxL643ttglsPOVNufr R9pmQD4EtHdrC4f4+GbEsHi5P0MmB3YXFeOs0hTAZ8ixkMO1xSw36YaWJUkzkmTiFUaP pKA0Pi+v4eSEK4jl8cwS4DUfdmakOCo2DplqH4SbqoHuTAi/YPERkXYCMUJt4sPRqWKq cBQ6Y7FdY93H4PLQb2R7fSZZ2hxBJRiyNc2Tz9HyQSATDxg4mnxx6fJ6Dkqd8J2bxgED JQ== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2130.oracle.com with ESMTP id 2y8uddkjgm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 22 Feb 2020 00:31:12 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01M0RxPl118096; Sat, 22 Feb 2020 00:31:12 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2yasdv1h1v-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sat, 22 Feb 2020 00:31:12 +0000 Received: from abhmp0005.oracle.com (abhmp0005.oracle.com [141.146.116.11]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 01M0VAgt025430; Sat, 22 Feb 2020 00:31:11 GMT Received: from localhost (/10.145.179.117) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 21 Feb 2020 16:31:10 -0800 Date: Fri, 21 Feb 2020 16:31:09 -0800 From: "Darrick J. Wong" To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, Alexander Viro , Dan Williams , Dave Chinner , 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 V4 09/13] fs/xfs: Add write aops lock to xfs layer Message-ID: <20200222003109.GE9506@magnolia> References: <20200221004134.30599-1-ira.weiny@intel.com> <20200221004134.30599-10-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221004134.30599-10-ira.weiny@intel.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9538 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 phishscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 suspectscore=1 mlxscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002220000 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9538 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 impostorscore=0 mlxlogscore=999 malwarescore=0 mlxscore=0 suspectscore=1 priorityscore=1501 bulkscore=0 adultscore=0 spamscore=0 lowpriorityscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002220000 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 04:41:30PM -0800, ira.weiny@intel.com wrote: > From: Ira Weiny > > XFS requires the use of the aops of an inode to quiesced prior to > changing it to/from the DAX aops vector. > > Take the aops write lock while changing DAX state. > > We define a new XFS_DAX_EXCL lock type to carry the lock through to > transaction completion. > > Signed-off-by: Ira Weiny > > --- > Changes from v3: > Change locking function names to reflect changes in previous > patches. > > Changes from V2: > Change name of patch (WAS: fs/xfs: Add lock/unlock state to xfs) > Remove the xfs specific lock and move to the vfs layer. > We still use XFS_LOCK_DAX_EXCL to be able to pass this > flag through to the transaction code. But we no longer > have a lock specific to xfs. This removes a lot of code > from the XFS layer, preps us for using this in ext4, and > is actually more straight forward now that all the > locking requirements are better known. > > Fix locking order comment > Rework for new 'state' names > (Other comments on the previous patch are not applicable with > new patch as much of the code was removed in favor of the vfs > level lock) > --- > fs/xfs/xfs_inode.c | 22 ++++++++++++++++++++-- > fs/xfs/xfs_inode.h | 7 +++++-- > 2 files changed, 25 insertions(+), 4 deletions(-) > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index 35df324875db..5b014c428f0f 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -142,12 +142,12 @@ xfs_ilock_attr_map_shared( > * > * Basic locking order: > * > - * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock > + * s_dax_sem -> i_rwsem -> i_mmap_lock -> page_lock -> i_ilock "dax_sem"? I thought this was now called i_aops_sem? > * > * mmap_sem locking order: > * > * i_rwsem -> page lock -> mmap_sem > - * mmap_sem -> i_mmap_lock -> page_lock > + * s_dax_sem -> mmap_sem -> i_mmap_lock -> page_lock > * > * The difference in mmap_sem locking order mean that we cannot hold the > * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can > @@ -182,6 +182,9 @@ xfs_ilock( > (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); > ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0); > > + if (lock_flags & XFS_DAX_EXCL) And similarly, I think this should be XFS_OPSLOCK_EXCL... --D > + inode_aops_down_write(VFS_I(ip)); > + > if (lock_flags & XFS_IOLOCK_EXCL) { > down_write_nested(&VFS_I(ip)->i_rwsem, > XFS_IOLOCK_DEP(lock_flags)); > @@ -224,6 +227,8 @@ xfs_ilock_nowait( > * You can't set both SHARED and EXCL for the same lock, > * and only XFS_IOLOCK_SHARED, XFS_IOLOCK_EXCL, XFS_ILOCK_SHARED, > * and XFS_ILOCK_EXCL are valid values to set in lock_flags. > + * > + * XFS_DAX_* is not allowed > */ > ASSERT((lock_flags & (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)) != > (XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL)); > @@ -232,6 +237,7 @@ xfs_ilock_nowait( > ASSERT((lock_flags & (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)) != > (XFS_ILOCK_SHARED | XFS_ILOCK_EXCL)); > ASSERT((lock_flags & ~(XFS_LOCK_MASK | XFS_LOCK_SUBCLASS_MASK)) == 0); > + ASSERT((lock_flags & XFS_DAX_EXCL) == 0); > > if (lock_flags & XFS_IOLOCK_EXCL) { > if (!down_write_trylock(&VFS_I(ip)->i_rwsem)) > @@ -318,6 +324,9 @@ xfs_iunlock( > else if (lock_flags & XFS_ILOCK_SHARED) > mrunlock_shared(&ip->i_lock); > > + if (lock_flags & XFS_DAX_EXCL) > + inode_aops_up_write(VFS_I(ip)); > + > trace_xfs_iunlock(ip, lock_flags, _RET_IP_); > } > > @@ -333,6 +342,8 @@ xfs_ilock_demote( > ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)); > ASSERT((lock_flags & > ~(XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)) == 0); > + /* XFS_DAX_* is not allowed */ > + ASSERT((lock_flags & XFS_DAX_EXCL) == 0); > > if (lock_flags & XFS_ILOCK_EXCL) > mrdemote(&ip->i_lock); > @@ -465,6 +476,9 @@ xfs_lock_inodes( > ASSERT(!(lock_mode & XFS_ILOCK_EXCL) || > inodes <= XFS_ILOCK_MAX_SUBCLASS + 1); > > + /* XFS_DAX_* is not allowed */ > + ASSERT((lock_mode & XFS_DAX_EXCL) == 0); > + > if (lock_mode & XFS_IOLOCK_EXCL) { > ASSERT(!(lock_mode & (XFS_MMAPLOCK_EXCL | XFS_ILOCK_EXCL))); > } else if (lock_mode & XFS_MMAPLOCK_EXCL) > @@ -566,6 +580,10 @@ xfs_lock_two_inodes( > ASSERT(!(ip0_mode & (XFS_MMAPLOCK_SHARED|XFS_MMAPLOCK_EXCL)) || > !(ip1_mode & (XFS_ILOCK_SHARED|XFS_ILOCK_EXCL))); > > + /* XFS_DAX_* is not allowed */ > + ASSERT((ip0_mode & XFS_DAX_EXCL) == 0); > + ASSERT((ip1_mode & XFS_DAX_EXCL) == 0); > + > ASSERT(ip0->i_ino != ip1->i_ino); > > if (ip0->i_ino > ip1->i_ino) { > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h > index 492e53992fa9..25fe20740bf7 100644 > --- a/fs/xfs/xfs_inode.h > +++ b/fs/xfs/xfs_inode.h > @@ -278,10 +278,12 @@ static inline void xfs_ifunlock(struct xfs_inode *ip) > #define XFS_ILOCK_SHARED (1<<3) > #define XFS_MMAPLOCK_EXCL (1<<4) > #define XFS_MMAPLOCK_SHARED (1<<5) > +#define XFS_DAX_EXCL (1<<6) > > #define XFS_LOCK_MASK (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED \ > | XFS_ILOCK_EXCL | XFS_ILOCK_SHARED \ > - | XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED) > + | XFS_MMAPLOCK_EXCL | XFS_MMAPLOCK_SHARED \ > + | XFS_DAX_EXCL) > > #define XFS_LOCK_FLAGS \ > { XFS_IOLOCK_EXCL, "IOLOCK_EXCL" }, \ > @@ -289,7 +291,8 @@ static inline void xfs_ifunlock(struct xfs_inode *ip) > { XFS_ILOCK_EXCL, "ILOCK_EXCL" }, \ > { XFS_ILOCK_SHARED, "ILOCK_SHARED" }, \ > { XFS_MMAPLOCK_EXCL, "MMAPLOCK_EXCL" }, \ > - { XFS_MMAPLOCK_SHARED, "MMAPLOCK_SHARED" } > + { XFS_MMAPLOCK_SHARED, "MMAPLOCK_SHARED" }, \ > + { XFS_DAX_EXCL, "DAX_EXCL" } > > > /* > -- > 2.21.0 >