Merge branch 'overlayfs-af_unix-fix' into overlayfs-linus

include/linux/dcache.h

@@ -575,5 +575,17 @@ static inline struct inode *vfs_select_inode(struct dentry *dentry,
 	return inode;
 }
 
+/**
+ * d_real_inode - Return the real inode
+ * @dentry: The dentry to query
+ *
+ * If dentry is on an union/overlay, then return the underlying, real inode.
+ * Otherwise return d_inode().
+ */
+static inline struct inode *d_real_inode(struct dentry *dentry)
+{
+	return d_backing_inode(d_real(dentry));
+}
+
 
 #endif	/* __LINUX_DCACHE_H */

net/unix/af_unix.c

@@ -315,7 +315,7 @@ static struct sock *unix_find_socket_byinode(struct inode *i)
 		    &unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
 		struct dentry *dentry = unix_sk(s)->path.dentry;
 
-		if (dentry && d_backing_inode(dentry) == i) {
+		if (dentry && d_real_inode(dentry) == i) {
 			sock_hold(s);
 			goto found;
 		}
@@ -911,7 +911,7 @@ static struct sock *unix_find_other(struct net *net,
 		err = kern_path(sunname->sun_path, LOOKUP_FOLLOW, &path);
 		if (err)
 			goto fail;
-		inode = d_backing_inode(path.dentry);
+		inode = d_real_inode(path.dentry);
 		err = inode_permission(inode, MAY_WRITE);
 		if (err)
 			goto put_fail;
@@ -1048,7 +1048,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 			goto out_up;
 		}
 		addr->hash = UNIX_HASH_SIZE;
-		hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
+		hash = d_real_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1);
 		spin_lock(&unix_table_lock);
 		u->path = u_path;
 		list = &unix_socket_table[hash];