Switch proc/self to nd_set_link()

commit 7fee4868 upstream.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

fs/proc/base.c

@@ -2304,16 +2304,30 @@ static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
 	struct pid_namespace *ns = dentry->d_sb->s_fs_info;
 	pid_t tgid = task_tgid_nr_ns(current, ns);
-	char tmp[PROC_NUMBUF];
-	if (!tgid)
-		return ERR_PTR(-ENOENT);
-	sprintf(tmp, "%d", task_tgid_nr_ns(current, ns));
-	return ERR_PTR(vfs_follow_link(nd,tmp));
+	char *name = ERR_PTR(-ENOENT);
+	if (tgid) {
+		name = __getname();
+		if (!name)
+			name = ERR_PTR(-ENOMEM);
+		else
+			sprintf(name, "%d", tgid);
+	}
+	nd_set_link(nd, name);
+	return NULL;
+}
+
+static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
+				void *cookie)
+{
+	char *s = nd_get_link(nd);
+	if (!IS_ERR(s))
+		__putname(s);
 }
 
 static const struct inode_operations proc_self_inode_operations = {
 	.readlink	= proc_self_readlink,
 	.follow_link	= proc_self_follow_link,
+	.put_link	= proc_self_put_link,
 };
 
 /*