nfsd: fail init on /proc/fs/nfs/exports creation failure

I assume the reason failure of creation was ignored here was just to
continue support embedded systems that want nfsd but not proc.

However, in cases where proc is supported it would be clearer to fail
entirely than to come up with some features disabled.
Acked-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfsctl.c

@@ -674,6 +674,27 @@ static struct file_system_type nfsd_fs_type = {
 	.kill_sb	= kill_litter_super,
 };
 
+#ifdef CONFIG_PROC_FS
+static int create_proc_exports_entry(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = proc_mkdir("fs/nfs", NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry = create_proc_entry("fs/nfs/exports", 0, NULL);
+	if (!entry)
+		return -ENOMEM;
+	entry->proc_fops =  &exports_operations;
+	return 0;
+}
+#else /* CONFIG_PROC_FS */
+static int create_proc_exports_entry(void)
+{
+	return 0;
+}
+#endif
+
 static int __init init_nfsd(void)
 {
 	int retval;
@@ -689,23 +710,21 @@ static int __init init_nfsd(void)
 	nfsd_export_init();	/* Exports table */
 	nfsd_lockd_init();	/* lockd->nfsd callbacks */
 	nfsd_idmap_init();      /* Name to ID mapping */
-	if (proc_mkdir("fs/nfs", NULL)) {
-		struct proc_dir_entry *entry;
-		entry = create_proc_entry("fs/nfs/exports", 0, NULL);
-		if (entry)
-			entry->proc_fops =  &exports_operations;
-	}
+	retval = create_proc_exports_entry();
+	if (retval)
+		goto out_free_idmap;
 	retval = register_filesystem(&nfsd_fs_type);
 	if (retval)
 		goto out_free_all;
 	return 0;
 out_free_all:
-	nfsd_idmap_shutdown();
-	nfsd_export_shutdown();
-	nfsd_reply_cache_shutdown();
 	remove_proc_entry("fs/nfs/exports", NULL);
 	remove_proc_entry("fs/nfs", NULL);
+	nfsd_idmap_shutdown();
+out_free_idmap:
 	nfsd_lockd_shutdown();
+	nfsd_export_shutdown();
+	nfsd_reply_cache_shutdown();
 out_free_stat:
 	nfsd_stat_shutdown();
 	nfsd4_free_slabs();