Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751551Ab0KIMsB (ORCPT ); Tue, 9 Nov 2010 07:48:01 -0500 Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:56555 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750869Ab0KIMsA (ORCPT ); Tue, 9 Nov 2010 07:48:00 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvsEAOrQ2Ex5LcZK/2dsb2JhbACiHnK/OoVKBA Date: Tue, 9 Nov 2010 23:47:57 +1100 From: Nick Piggin To: Al Viro , Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [patch 2/6] fs: icache avoid RCU freeing for pseudo fs Message-ID: <20101109124757.GC11477@amd> References: <20101109124610.GB11477@amd> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101109124610.GB11477@amd> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4198 Lines: 117 Filesystems that don't put inode on any RCU list or reachable by rcu-walk dentries do not need to RCU free their inodes. Signed-off-by: Nick Piggin --- fs/inode.c | 6 ++++++ fs/pipe.c | 6 +++++- include/linux/fs.h | 1 + include/linux/net.h | 1 + net/socket.c | 17 +++++++++-------- 5 files changed, 22 insertions(+), 9 deletions(-) Index: linux-2.6/net/socket.c =================================================================== --- linux-2.6.orig/net/socket.c 2010-11-09 22:11:10.000000000 +1100 +++ linux-2.6/net/socket.c 2010-11-09 22:11:10.000000000 +1100 @@ -262,20 +262,21 @@ static struct inode *sock_alloc_inode(st } -static void sock_free_rcu(struct rcu_head *head) + +static void wq_free_rcu(struct rcu_head *head) { - struct inode *inode = container_of(head, struct inode, i_rcu); - struct socket_alloc *ei = container_of(inode, struct socket_alloc, - vfs_inode); + struct socket_wq *wq = container_of(head, struct socket_wq, rcu); - kfree(ei->socket.wq); - INIT_LIST_HEAD(&inode->i_dentry); - kmem_cache_free(sock_inode_cachep, ei); + kfree(wq); } static void sock_destroy_inode(struct inode *inode) { - call_rcu(&inode->i_rcu, sock_free_rcu); + struct socket_alloc *ei; + + ei = container_of(inode, struct socket_alloc, vfs_inode); + call_rcu(&ei->socket.wq->rcu, wq_free_rcu); + kmem_cache_free(sock_inode_cachep, ei); } static void init_once(void *foo) Index: linux-2.6/fs/inode.c =================================================================== --- linux-2.6.orig/fs/inode.c 2010-11-09 22:11:10.000000000 +1100 +++ linux-2.6/fs/inode.c 2010-11-09 22:11:10.000000000 +1100 @@ -255,6 +255,12 @@ static struct inode *alloc_inode(struct return inode; } +void free_inode_nonrcu(struct inode *inode) +{ + kmem_cache_free(inode_cachep, inode); +} +EXPORT_SYMBOL(free_inode_nonrcu); + void __destroy_inode(struct inode *inode) { BUG_ON(inode_has_buffers(inode)); Index: linux-2.6/fs/pipe.c =================================================================== --- linux-2.6.orig/fs/pipe.c 2010-11-09 22:11:00.000000000 +1100 +++ linux-2.6/fs/pipe.c 2010-11-09 22:11:10.000000000 +1100 @@ -1241,6 +1241,10 @@ long pipe_fcntl(struct file *file, unsig return ret; } +static const struct super_operations pipefs_ops = { + .destroy_inode = free_inode_nonrcu, +}; + /* * pipefs should _never_ be mounted by userland - too much of security hassle, * no real gain from having the whole whorehouse mounted. So we don't need @@ -1250,7 +1254,7 @@ long pipe_fcntl(struct file *file, unsig static struct dentry *pipefs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { - return mount_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC); + return mount_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC); } static struct file_system_type pipe_fs_type = { Index: linux-2.6/include/linux/fs.h =================================================================== --- linux-2.6.orig/include/linux/fs.h 2010-11-09 22:11:10.000000000 +1100 +++ linux-2.6/include/linux/fs.h 2010-11-09 22:11:10.000000000 +1100 @@ -2233,6 +2233,7 @@ extern void iget_failed(struct inode *); extern void end_writeback(struct inode *); extern void __destroy_inode(struct inode *); extern struct inode *new_inode(struct super_block *); +extern void free_inode_nonrcu(struct inode *inode); extern int should_remove_suid(struct dentry *); extern int file_remove_suid(struct file *); Index: linux-2.6/include/linux/net.h =================================================================== --- linux-2.6.orig/include/linux/net.h 2010-11-09 22:11:10.000000000 +1100 +++ linux-2.6/include/linux/net.h 2010-11-09 22:11:10.000000000 +1100 @@ -120,6 +120,7 @@ enum sock_shutdown_cmd { struct socket_wq { wait_queue_head_t wait; struct fasync_struct *fasync_list; + struct rcu_head rcu; } ____cacheline_aligned_in_smp; /** -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/