diff --git a/fsck/inject.c b/fsck/inject.c
index f6fd346..f29e746 100644
--- a/fsck/inject.c
+++ b/fsck/inject.c
@@ -18,17 +18,43 @@ void inject_usage(void)
 	MSG(0, "[options]:\n");
 	MSG(0, "  -d debug level [default:0]\n");
 	MSG(0, "  -V print the version number and exit\n");
+	MSG(0, "  --mb <member name> which member is injected in a struct\n");
+	MSG(0, "  --val <new value> new value to set\n");
+	MSG(0, "  --str <new string> new string to set\n");
+	MSG(0, "  --idx <slot index> which slot is injected in an array\n");
+	MSG(0, "  --sb <0|1|2> --mb <name> [--idx <index>] --val/str <value/string> inject superblock\n");
 	MSG(0, "  --dry-run do not really inject\n");
 
 	exit(1);
 }
 
+static void inject_sb_usage(void)
+{
+	MSG(0, "inject.f2fs --sb <0|1|2> --mb <name> [--idx <index>] --val/str <value/string>\n");
+	MSG(0, "[sb]:\n");
+	MSG(0, "  0: auto select the first super block\n");
+	MSG(0, "  1: select the first super block\n");
+	MSG(0, "  2: select the second super block\n");
+	MSG(0, "[mb]:\n");
+	MSG(0, "  magic: inject magic number\n");
+	MSG(0, "  s_stop_reason: inject s_stop_reason array selected by --idx <index>\n");
+	MSG(0, "  s_errors: inject s_errors array selected by --idx <index>\n");
+	MSG(0, "  devs.path: inject path in devs array selected by --idx <index> specified by --str <string>\n");
+}
+
 int inject_parse_options(int argc, char *argv[], struct inject_option *opt)
 {
 	int o = 0;
-	const char *option_string = "d:V";
+	const char *pack[] = {"auto", "1", "2"};
+	const char *option_string = "d:Vh";
+	char *endptr;
 	struct option long_opt[] = {
 		{"dry-run", no_argument, 0, 1},
+		{"mb", required_argument, 0, 2},
+		{"idx", required_argument, 0, 3},
+		{"val", required_argument, 0, 4},
+		{"str", required_argument, 0, 5},
+		{"sb", required_argument, 0, 6},
 		{0, 0, 0, 0}
 	};
 
@@ -39,6 +65,38 @@ int inject_parse_options(int argc, char *argv[], struct inject_option *opt)
 			c.dry_run = 1;
 			MSG(0, "Info: Dry run\n");
 			break;
+		case 2:
+			opt->mb = optarg;
+			MSG(0, "Info: inject member %s\n", optarg);
+			break;
+		case 3:
+			if (!is_digits(optarg))
+				return EWRONG_OPT;
+			opt->idx = atoi(optarg);
+			MSG(0, "Info: inject slot index %d\n", opt->idx);
+			break;
+		case 4:
+			opt->val = strtoll(optarg, &endptr, 0);
+			if (opt->val == LLONG_MAX || opt->val == LLONG_MIN ||
+			    *endptr != '\0')
+				return -ERANGE;
+			MSG(0, "Info: inject value %lld : 0x%llx\n", opt->val,
+			    (unsigned long long)opt->val);
+			break;
+		case 5:
+			opt->str = strdup(optarg);
+			if (!opt->str)
+				return -ENOMEM;
+			MSG(0, "Info: inject string %s\n", opt->str);
+			break;
+		case 6:
+			if (!is_digits(optarg))
+				return EWRONG_OPT;
+			opt->sb = atoi(optarg);
+			if (opt->sb < 0 || opt->sb > 2)
+				return -ERANGE;
+			MSG(0, "Info: inject sb %s\n", pack[opt->sb]);
+			break;
 		case 'd':
 			if (optarg[0] == '-' || !is_digits(optarg))
 				return EWRONG_OPT;
@@ -48,7 +106,12 @@ int inject_parse_options(int argc, char *argv[], struct inject_option *opt)
 		case 'V':
 			show_version("inject.f2fs");
 			exit(0);
+		case 'h':
 		default:
+			if (opt->sb >= 0) {
+				inject_sb_usage();
+				exit(0);
+			}
 			return EUNKNOWN_OPT;
 		}
 	}
@@ -56,9 +119,84 @@ int inject_parse_options(int argc, char *argv[], struct inject_option *opt)
 	return 0;
 }
 
+static int inject_sb(struct f2fs_sb_info *sbi, struct inject_option *opt)
+{
+	struct f2fs_super_block *sb;
+	char *buf;
+	int ret;
+
+	buf = calloc(1, F2FS_BLKSIZE);
+	ASSERT(buf != NULL);
+
+	if (opt->sb == 0)
+		opt->sb = 1;
+
+	ret = dev_read_block(buf, opt->sb == 1 ? SB0_ADDR : SB1_ADDR);
+	ASSERT(ret >= 0);
+
+	sb = (struct f2fs_super_block *)(buf + F2FS_SUPER_OFFSET);
+
+	if (!strcmp(opt->mb, "magic")) {
+		MSG(0, "Info: inject magic of sb %d: 0x%x -> 0x%x\n",
+		    opt->sb, get_sb(magic), (u32)opt->val);
+		set_sb(magic, (u32)opt->val);
+	} else if (!strcmp(opt->mb, "s_stop_reason")) {
+		if (opt->idx >= MAX_STOP_REASON) {
+			ERR_MSG("invalid index %u of sb->s_stop_reason[]\n",
+				opt->idx);
+			ret = -EINVAL;
+			goto out;
+		}
+		MSG(0, "Info: inject s_stop_reason[%d] of sb %d: %d -> %d\n",
+		    opt->idx, opt->sb, sb->s_stop_reason[opt->idx],
+		    (u8)opt->val);
+		sb->s_stop_reason[opt->idx] = (u8)opt->val;
+	} else if (!strcmp(opt->mb, "s_errors")) {
+		if (opt->idx >= MAX_F2FS_ERRORS) {
+			ERR_MSG("invalid index %u of sb->s_errors[]\n",
+				opt->idx);
+			ret = -EINVAL;
+			goto out;
+		}
+		MSG(0, "Info: inject s_errors[%d] of sb %d: %x -> %x\n",
+		    opt->idx, opt->sb, sb->s_errors[opt->idx], (u8)opt->val);
+		sb->s_errors[opt->idx] = (u8)opt->val;
+	} else if (!strcmp(opt->mb, "devs.path")) {
+		if (opt->idx >= MAX_DEVICES) {
+			ERR_MSG("invalid index %u of sb->devs[]\n", opt->idx);
+			ret = -EINVAL;
+			goto out;
+		}
+		if (strlen(opt->str) >= MAX_PATH_LEN) {
+			ERR_MSG("invalid length of option str\n");
+			ret = -EINVAL;
+			goto out;
+		}
+		MSG(0, "Info: inject devs[%d].path of sb %d: %s -> %s\n",
+		    opt->idx, opt->sb, (char *)sb->devs[opt->idx].path, opt->str);
+		strcpy((char *)sb->devs[opt->idx].path, opt->str);
+	} else {
+		ERR_MSG("unknown or unsupported member \"%s\"\n", opt->mb);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	print_raw_sb_info(sb);
+	update_superblock(sb, SB_MASK((u32)opt->sb - 1));
+
+out:
+	free(buf);
+	free(opt->str);
+	return ret;
+}
+
 int do_inject(struct f2fs_sb_info *sbi)
 {
+	struct inject_option *opt = (struct inject_option *)c.private;
 	int ret = -EINVAL;
 
+	if (opt->sb >= 0)
+		ret = inject_sb(sbi, opt);
+
 	return ret;
 }
diff --git a/fsck/inject.h b/fsck/inject.h
index 62543c1..c7d0e33 100644
--- a/fsck/inject.h
+++ b/fsck/inject.h
@@ -20,6 +20,11 @@
 #include "fsck.h"
 
 struct inject_option {
+	const char *mb;		/* member name */
+	unsigned int idx;	/* slot index */
+	long long val;		/* new value */
+	char *str;		/* new string */
+	int sb;			/* which sb */
 };
 
 void inject_usage(void);
diff --git a/fsck/main.c b/fsck/main.c
index eca09aa..40edf35 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -822,7 +822,10 @@ void f2fs_parse_options(int argc, char *argv[])
 #endif /* WITH_LABEL */
 	} else if (!strcmp("inject.f2fs", prog)) {
 #ifdef WITH_INJECT
-		static struct inject_option inject_opt;
+		static struct inject_option inject_opt = {
+			.sb = -1,
+			.idx = -1,
+		};
 
 		err = inject_parse_options(argc, argv, &inject_opt);
 		if (err < 0) {
diff --git a/fsck/mount.c b/fsck/mount.c
index 8524335..77e3919 100644
--- a/fsck/mount.c
+++ b/fsck/mount.c
@@ -1212,7 +1212,7 @@ int init_sb_info(struct f2fs_sb_info *sbi)
 			c.devices[i].path = strdup((char *)sb->devs[i].path);
 			if (get_device_info(i))
 				ASSERT(0);
-		} else {
+		} else if (c.func != INJECT) {
 			ASSERT(!strcmp((char *)sb->devs[i].path,
 						(char *)c.devices[i].path));
 		}
@@ -4018,7 +4018,7 @@ int f2fs_do_mount(struct f2fs_sb_info *sbi)
 	}
 	cp = F2FS_CKPT(sbi);
 
-	if (c.func != FSCK && c.func != DUMP &&
+	if (c.func != FSCK && c.func != DUMP && c.func != INJECT &&
 		!is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG)) {
 		ERR_MSG("Mount unclean image to replay log first\n");
 		return -1;
