fs: devpts_pty_new() return -ENOMEM if dentry allocation failed

In this case nobody can open a slave point, so will be better return
from devpts_pty_new()

Now we should not check error code from d_find_alias() in
devpts_pty_kill(), because the dentry exists all times.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/devpts/inode.c

@@ -479,6 +479,7 @@ int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
 	struct dentry *root = sb->s_root;
 	struct pts_fs_info *fsi = DEVPTS_SB(sb);
 	struct pts_mount_opts *opts = &fsi->mount_opts;
+	int ret = 0;
 	char s[12];
 
 	/* We're supposed to be given the slave end of a pty */
@@ -504,11 +505,14 @@ int devpts_pty_new(struct inode *ptmx_inode, struct tty_struct *tty)
 	if (!IS_ERR(dentry)) {
 		d_add(dentry, inode);
 		fsnotify_create(root->d_inode, dentry);
+	} else {
+		iput(inode);
+		ret = -ENOMEM;
 	}
 
 	mutex_unlock(&root->d_inode->i_mutex);
 
-	return 0;
+	return ret;
 }
 
 struct tty_struct *devpts_get_tty(struct inode *pts_inode, int number)
@@ -544,17 +548,12 @@ void devpts_pty_kill(struct tty_struct *tty)
 	mutex_lock(&root->d_inode->i_mutex);
 
 	dentry = d_find_alias(inode);
-	if (IS_ERR(dentry))
-		goto out;
-
-	if (dentry) {
-		inode->i_nlink--;
-		d_delete(dentry);
-		dput(dentry);	/* d_alloc_name() in devpts_pty_new() */
-	}
 
+	inode->i_nlink--;
+	d_delete(dentry);
+	dput(dentry);	/* d_alloc_name() in devpts_pty_new() */
 	dput(dentry);		/* d_find_alias above */
-out:
+
 	mutex_unlock(&root->d_inode->i_mutex);
 }