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=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 73446C2BA19 for ; Thu, 23 Apr 2020 08:40:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55D4F2084D for ; Thu, 23 Apr 2020 08:40:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726744AbgDWIk4 (ORCPT ); Thu, 23 Apr 2020 04:40:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:44290 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbgDWIk4 (ORCPT ); Thu, 23 Apr 2020 04:40:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id EA591AFDC; Thu, 23 Apr 2020 08:40:53 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id ED3521E0E61; Thu, 23 Apr 2020 10:40:51 +0200 (CEST) Date: Thu, 23 Apr 2020 10:40:51 +0200 From: Jan Kara To: ira.weiny@intel.com Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, "Darrick J. Wong" , Al Viro , Jan Kara , Dan Williams , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jeff Moyer , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH V10 10/11] fs: Introduce DCACHE_DONTCACHE Message-ID: <20200423084051.GC3737@quack2.suse.cz> References: <20200422212102.3757660-1-ira.weiny@intel.com> <20200422212102.3757660-11-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200422212102.3757660-11-ira.weiny@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Wed 22-04-20 14:21:01, ira.weiny@intel.com wrote: > From: Ira Weiny > > DCACHE_DONTCACHE indicates a dentry should not be cached on final > dput(). > > Also add a helper function to mark DCACHE_DONTCACHE on all dentries > pointing to a specific inode when that inode is being set I_DONTCACHE. > > This facilitates dropping dentry references to inodes sooner which > require eviction to swap S_DAX mode. > > Cc: Al Viro > Signed-off-by: Ira Weiny The patch looks good to me. You can add: Reviewed-by: Jan Kara Honza > > --- > Changes from V9: > modify i_state under i_lock > Update comment > "Purge from memory on final dput()" > > Changes from V8: > Update commit message > Use mark_inode_dontcache in XFS > Fix locking... can't use rcu here. > Change name to mark_inode_dontcache > --- > fs/dcache.c | 4 ++++ > fs/inode.c | 15 +++++++++++++++ > fs/xfs/xfs_icache.c | 2 +- > include/linux/dcache.h | 2 ++ > include/linux/fs.h | 1 + > 5 files changed, 23 insertions(+), 1 deletion(-) > > diff --git a/fs/dcache.c b/fs/dcache.c > index b280e07e162b..0030fabab2c4 100644 > --- a/fs/dcache.c > +++ b/fs/dcache.c > @@ -647,6 +647,10 @@ static inline bool retain_dentry(struct dentry *dentry) > if (dentry->d_op->d_delete(dentry)) > return false; > } > + > + if (unlikely(dentry->d_flags & DCACHE_DONTCACHE)) > + return false; > + > /* retain; LRU fodder */ > dentry->d_lockref.count--; > if (unlikely(!(dentry->d_flags & DCACHE_LRU_LIST))) > diff --git a/fs/inode.c b/fs/inode.c > index 93d9252a00ab..316355433797 100644 > --- a/fs/inode.c > +++ b/fs/inode.c > @@ -1526,6 +1526,21 @@ int generic_delete_inode(struct inode *inode) > } > EXPORT_SYMBOL(generic_delete_inode); > > +void mark_inode_dontcache(struct inode *inode) > +{ > + struct dentry *de; > + > + spin_lock(&inode->i_lock); > + hlist_for_each_entry(de, &inode->i_dentry, d_u.d_alias) { > + spin_lock(&de->d_lock); > + de->d_flags |= DCACHE_DONTCACHE; > + spin_unlock(&de->d_lock); > + } > + inode->i_state |= I_DONTCACHE; > + spin_unlock(&inode->i_lock); > +} > +EXPORT_SYMBOL(mark_inode_dontcache); > + > /* > * Called when we're dropping the last reference > * to an inode. > diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c > index de76f7f60695..3c8f44477804 100644 > --- a/fs/xfs/xfs_icache.c > +++ b/fs/xfs/xfs_icache.c > @@ -559,7 +559,7 @@ xfs_iget_cache_miss( > */ > iflags = XFS_INEW; > if (flags & XFS_IGET_DONTCACHE) > - VFS_I(ip)->i_state |= I_DONTCACHE; > + mark_inode_dontcache(VFS_I(ip)); > ip->i_udquot = NULL; > ip->i_gdquot = NULL; > ip->i_pdquot = NULL; > diff --git a/include/linux/dcache.h b/include/linux/dcache.h > index c1488cc84fd9..a81f0c3cf352 100644 > --- a/include/linux/dcache.h > +++ b/include/linux/dcache.h > @@ -177,6 +177,8 @@ struct dentry_operations { > > #define DCACHE_REFERENCED 0x00000040 /* Recently used, don't discard. */ > > +#define DCACHE_DONTCACHE 0x00000080 /* Purge from memory on final dput() */ > + > #define DCACHE_CANT_MOUNT 0x00000100 > #define DCACHE_GENOCIDE 0x00000200 > #define DCACHE_SHRINK_LIST 0x00000400 > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 44bd45af760f..064168ec2e0b 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -3055,6 +3055,7 @@ static inline int generic_drop_inode(struct inode *inode) > return !inode->i_nlink || inode_unhashed(inode) || > (inode->i_state & I_DONTCACHE); > } > +extern void mark_inode_dontcache(struct inode *inode); > > extern struct inode *ilookup5_nowait(struct super_block *sb, > unsigned long hashval, int (*test)(struct inode *, void *), > -- > 2.25.1 > -- Jan Kara SUSE Labs, CR