f2fs: add sanity check for proc_mkdir

Return -ENOMEM when proc_mkdir failed.
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/sysfs.c

@@ -1386,12 +1386,19 @@ int __init f2fs_init_sysfs(void)
 
 	ret = kobject_init_and_add(&f2fs_feat, &f2fs_feat_ktype,
 				   NULL, "features");
-	if (ret) {
-		kobject_put(&f2fs_feat);
-		kset_unregister(&f2fs_kset);
-	} else {
-		f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+	if (ret)
+		goto put_kobject;
+
+	f2fs_proc_root = proc_mkdir("fs/f2fs", NULL);
+	if (!f2fs_proc_root) {
+		ret = -ENOMEM;
+		goto put_kobject;
 	}
+
+	return 0;
+put_kobject:
+	kobject_put(&f2fs_feat);
+	kset_unregister(&f2fs_kset);
 	return ret;
 }
 
@@ -1430,23 +1437,24 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
 	if (err)
 		goto put_feature_list_kobj;
 
-	if (f2fs_proc_root)
-		sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+	sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root);
+	if (!sbi->s_proc) {
+		err = -ENOMEM;
+		goto put_feature_list_kobj;
+	}
 
-	if (sbi->s_proc) {
-		proc_create_single_data("segment_info", 0444, sbi->s_proc,
+	proc_create_single_data("segment_info", 0444, sbi->s_proc,
 				segment_info_seq_show, sb);
-		proc_create_single_data("segment_bits", 0444, sbi->s_proc,
+	proc_create_single_data("segment_bits", 0444, sbi->s_proc,
 				segment_bits_seq_show, sb);
 #ifdef CONFIG_F2FS_IOSTAT
-		proc_create_single_data("iostat_info", 0444, sbi->s_proc,
+	proc_create_single_data("iostat_info", 0444, sbi->s_proc,
 				iostat_info_seq_show, sb);
 #endif
-		proc_create_single_data("victim_bits", 0444, sbi->s_proc,
+	proc_create_single_data("victim_bits", 0444, sbi->s_proc,
 				victim_bits_seq_show, sb);
-		proc_create_single_data("discard_plist_info", 0444, sbi->s_proc,
+	proc_create_single_data("discard_plist_info", 0444, sbi->s_proc,
 				discard_plist_seq_show, sb);
-	}
 	return 0;
 put_feature_list_kobj:
 	kobject_put(&sbi->s_feature_list_kobj);
@@ -1462,8 +1470,7 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi)
 
 void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi)
 {
-	if (sbi->s_proc)
-		remove_proc_subtree(sbi->sb->s_id, f2fs_proc_root);
+	remove_proc_subtree(sbi->sb->s_id, f2fs_proc_root);
 
 	kobject_put(&sbi->s_stat_kobj);
 	wait_for_completion(&sbi->s_stat_kobj_unregister);