Pseudo filesystems that don't put inode on RCU list or reachable by
rcu-walk dentries do not need to RCU free their inodes.
Signed-off-by: Nick Piggin <npiggin@xxxxxxxxx>
---
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 2010-10-19 14:18:59.000000000 +1100
+++ linux-2.6/net/socket.c 2010-10-19 14:19:22.000000000 +1100
@@ -262,20 +262,21 @@
}
-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 2010-10-19 14:18:59.000000000 +1100
+++ linux-2.6/fs/inode.c 2010-10-19 14:19:25.000000000 +1100
@@ -263,6 +263,12 @@
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 2010-10-19 14:17:18.000000000 +1100
+++ linux-2.6/fs/pipe.c 2010-10-19 14:19:22.000000000 +1100
@@ -1239,6 +1239,10 @@
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
@@ -1249,7 +1253,7 @@
int flags, const char *dev_name, void *data,
struct vfsmount *mnt)
{
- return get_sb_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC, mnt);
+ return get_sb_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC, mnt);
}
static struct file_system_type pipe_fs_type = {
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2010-10-19 14:18:59.000000000 +1100
+++ linux-2.6/include/linux/fs.h 2010-10-19 14:19:24.000000000 +1100
@@ -2196,6 +2196,7 @@
extern void destroy_inode(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 2010-10-19 14:18:59.000000000 +1100
+++ linux-2.6/include/linux/net.h 2010-10-19 14:18:59.000000000 +1100
@@ -120,6 +120,7 @@
struct socket_wq {
wait_queue_head_t wait;
struct fasync_struct *fasync_list;
+ struct rcu_head rcu;
} ____cacheline_aligned_in_smp;
/**
--
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