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>
This commit is contained in:
Nick Piggin 2011-01-07 17:49:50 +11:00
parent fa0d7e3de6
commit ff0c7d15f9
5 changed files with 23 additions and 10 deletions

View File

@ -257,6 +257,12 @@ static struct inode *alloc_inode(struct super_block *sb)
return inode; 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) void __destroy_inode(struct inode *inode)
{ {
BUG_ON(inode_has_buffers(inode)); BUG_ON(inode_has_buffers(inode));

View File

@ -1253,6 +1253,10 @@ out:
return ret; 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, * 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 * no real gain from having the whole whorehouse mounted. So we don't need
@ -1262,7 +1266,7 @@ out:
static struct dentry *pipefs_mount(struct file_system_type *fs_type, static struct dentry *pipefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data) 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 = { static struct file_system_type pipe_fs_type = {

View File

@ -2233,6 +2233,7 @@ extern void iget_failed(struct inode *);
extern void end_writeback(struct inode *); extern void end_writeback(struct inode *);
extern void __destroy_inode(struct inode *); extern void __destroy_inode(struct inode *);
extern struct inode *new_inode(struct super_block *); 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 should_remove_suid(struct dentry *);
extern int file_remove_suid(struct file *); extern int file_remove_suid(struct file *);

View File

@ -120,6 +120,7 @@ enum sock_shutdown_cmd {
struct socket_wq { struct socket_wq {
wait_queue_head_t wait; wait_queue_head_t wait;
struct fasync_struct *fasync_list; struct fasync_struct *fasync_list;
struct rcu_head rcu;
} ____cacheline_aligned_in_smp; } ____cacheline_aligned_in_smp;
/** /**

View File

@ -262,20 +262,21 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
} }
static void sock_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);
kfree(ei->socket.wq); static void wq_free_rcu(struct rcu_head *head)
INIT_LIST_HEAD(&inode->i_dentry); {
kmem_cache_free(sock_inode_cachep, ei); struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
kfree(wq);
} }
static void sock_destroy_inode(struct inode *inode) 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) static void init_once(void *foo)