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authorNick Piggin <npiggin@kernel.dk>2011-01-07 01:49:50 -0500
committerNick Piggin <npiggin@kernel.dk>2011-01-07 01:50:26 -0500
commitff0c7d15f9787b7e8c601533c015295cc68329f8 (patch)
treee3db53950b8ed78e542ab35a3cd3a6eaee26eccd
parentfa0d7e3de6d6fc5004ad9dea0dd6b286af8f03e9 (diff)
fs: avoid inode RCU freeing for pseudo fs
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@kernel.dk>
-rw-r--r--fs/inode.c6
-rw-r--r--fs/pipe.c6
-rw-r--r--include/linux/fs.h1
-rw-r--r--include/linux/net.h1
-rw-r--r--net/socket.c17
5 files changed, 22 insertions, 9 deletions
diff --git a/fs/inode.c b/fs/inode.c
index 6751dfe8cc06..da85e56378f3 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -257,6 +257,12 @@ static struct inode *alloc_inode(struct super_block *sb)
257 return inode; 257 return inode;
258} 258}
259 259
260void free_inode_nonrcu(struct inode *inode)
261{
262 kmem_cache_free(inode_cachep, inode);
263}
264EXPORT_SYMBOL(free_inode_nonrcu);
265
260void __destroy_inode(struct inode *inode) 266void __destroy_inode(struct inode *inode)
261{ 267{
262 BUG_ON(inode_has_buffers(inode)); 268 BUG_ON(inode_has_buffers(inode));
diff --git a/fs/pipe.c b/fs/pipe.c
index 04629f36e397..ae3592dcc88c 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1253,6 +1253,10 @@ out:
1253 return ret; 1253 return ret;
1254} 1254}
1255 1255
1256static const struct super_operations pipefs_ops = {
1257 .destroy_inode = free_inode_nonrcu,
1258};
1259
1256/* 1260/*
1257 * pipefs should _never_ be mounted by userland - too much of security hassle, 1261 * pipefs should _never_ be mounted by userland - too much of security hassle,
1258 * no real gain from having the whole whorehouse mounted. So we don't need 1262 * no real gain from having the whole whorehouse mounted. So we don't need
@@ -1262,7 +1266,7 @@ out:
1262static struct dentry *pipefs_mount(struct file_system_type *fs_type, 1266static struct dentry *pipefs_mount(struct file_system_type *fs_type,
1263 int flags, const char *dev_name, void *data) 1267 int flags, const char *dev_name, void *data)
1264{ 1268{
1265 return mount_pseudo(fs_type, "pipe:", NULL, PIPEFS_MAGIC); 1269 return mount_pseudo(fs_type, "pipe:", &pipefs_ops, PIPEFS_MAGIC);
1266} 1270}
1267 1271
1268static struct file_system_type pipe_fs_type = { 1272static struct file_system_type pipe_fs_type = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1ff4d0a33b25..ea202fff44f8 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2233,6 +2233,7 @@ extern void iget_failed(struct inode *);
2233extern void end_writeback(struct inode *); 2233extern void end_writeback(struct inode *);
2234extern void __destroy_inode(struct inode *); 2234extern void __destroy_inode(struct inode *);
2235extern struct inode *new_inode(struct super_block *); 2235extern struct inode *new_inode(struct super_block *);
2236extern void free_inode_nonrcu(struct inode *inode);
2236extern int should_remove_suid(struct dentry *); 2237extern int should_remove_suid(struct dentry *);
2237extern int file_remove_suid(struct file *); 2238extern int file_remove_suid(struct file *);
2238 2239
diff --git a/include/linux/net.h b/include/linux/net.h
index 06bde4908473..16faa130088c 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -120,6 +120,7 @@ enum sock_shutdown_cmd {
120struct socket_wq { 120struct socket_wq {
121 wait_queue_head_t wait; 121 wait_queue_head_t wait;
122 struct fasync_struct *fasync_list; 122 struct fasync_struct *fasync_list;
123 struct rcu_head rcu;
123} ____cacheline_aligned_in_smp; 124} ____cacheline_aligned_in_smp;
124 125
125/** 126/**
diff --git a/net/socket.c b/net/socket.c
index 97fff3a4e72f..817dc92e9ef8 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -262,20 +262,21 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
262} 262}
263 263
264 264
265static void sock_free_rcu(struct rcu_head *head) 265
266static void wq_free_rcu(struct rcu_head *head)
266{ 267{
267 struct inode *inode = container_of(head, struct inode, i_rcu); 268 struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
268 struct socket_alloc *ei = container_of(inode, struct socket_alloc,
269 vfs_inode);
270 269
271 kfree(ei->socket.wq); 270 kfree(wq);
272 INIT_LIST_HEAD(&inode->i_dentry);
273 kmem_cache_free(sock_inode_cachep, ei);
274} 271}
275 272
276static void sock_destroy_inode(struct inode *inode) 273static void sock_destroy_inode(struct inode *inode)
277{ 274{
278 call_rcu(&inode->i_rcu, sock_free_rcu); 275 struct socket_alloc *ei;
276
277 ei = container_of(inode, struct socket_alloc, vfs_inode);
278 call_rcu(&ei->socket.wq->rcu, wq_free_rcu);
279 kmem_cache_free(sock_inode_cachep, ei);
279} 280}
280 281
281static void init_once(void *foo) 282static void init_once(void *foo)