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>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1ff4d0a..ea202ff 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2233,6 +2233,7 @@
 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 *);
 
diff --git a/include/linux/net.h b/include/linux/net.h
index 06bde49..16faa13 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -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;
 
 /**