diff --git a/Assemble.c b/Assemble.c
index c7563ab2..2d1ff448 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -2221,8 +2221,8 @@ int assemble_container_content(struct supertype *st, int mdfd,
 		set_array_assembly_status(c, result, INCR_NO, &array);
 	else {
 		set_array_assembly_status(c, result, INCR_YES, &array);
-		wait_for(chosen_name, mdfd);
 		sysfs_rules_apply(chosen_name, content, st);
+		wait_for(chosen_name, mdfd);
 	}
 
 	return err;
diff --git a/Create.c b/Create.c
index 3a4eff77..acf75aba 100644
--- a/Create.c
+++ b/Create.c
@@ -523,6 +523,7 @@ int Create(struct supertype *st, struct mddev_ident *ident, int subdevs,
 	int container_fd = -1;
 	int need_mdmon = 0;
 	unsigned long long bitmapsize;
+	bool udev_blocked;
 	struct mdinfo info;
 	int did_default = 0;
 	int do_default_layout = 0;
@@ -1029,7 +1030,8 @@ int Create(struct supertype *st, struct mddev_ident *ident, int subdevs,
 
 	/* We need to create the device */
 	map_lock(&map);
-	mdfd = create_mddev(ident->devname, ident->name, LOCAL, chosen_name, 1);
+	udev_blocked = udev_is_available();
+	mdfd = create_mddev(ident->devname, ident->name, LOCAL, chosen_name, udev_blocked);
 	if (mdfd < 0) {
 		map_unlock(&map);
 		return 1;
@@ -1043,7 +1045,8 @@ int Create(struct supertype *st, struct mddev_ident *ident, int subdevs,
 		pr_err("Array name %s is in use already.\n", chosen_name);
 		close(mdfd);
 		map_unlock(&map);
-		udev_unblock();
+		if (udev_blocked)
+			udev_unblock();
 		return 1;
 	}
 
@@ -1331,14 +1334,15 @@ int Create(struct supertype *st, struct mddev_ident *ident, int subdevs,
 		pr_err("not starting array - not enough devices.\n");
 	}
 	close(mdfd);
-	udev_unblock();
-	sysfs_uevent(&info, "change");
+	if (udev_blocked)
+		udev_ready(&info);
 	dev_policy_free(custom_pols);
 
 	return 0;
 
  abort:
-	udev_unblock();
+	if (udev_blocked)
+		udev_unblock();
 	map_lock(&map);
  abort_locked:
 	map_remove(&map, fd2devnm(mdfd));
diff --git a/Incremental.c b/Incremental.c
index f717c9c3..2cf625ef 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -107,6 +107,8 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 	int have_target;
 	char *devname = devlist->devname;
 	int journal_device_missing = 0;
+	bool array_started = false;
+	bool udev_blocked = false;
 
 	if (!stat_is_blkdev(devname, &rdev))
 		return rv;
@@ -286,8 +288,9 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 			goto out_unlock;
 
 		/* Couldn't find an existing array, maybe make a new one */
+		udev_blocked = udev_is_available();
 		mdfd = create_mddev(match ? match->devname : NULL, name_to_use, trustworthy,
-				    chosen_name, 1);
+				    chosen_name, udev_blocked);
 
 		if (mdfd < 0)
 			goto out_unlock;
@@ -469,14 +472,12 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 			       chosen_name, info.array.working_disks,
 			       info.array.working_disks == 1?"":"s");
 		sysfs_rules_apply(chosen_name, &info, st);
-		wait_for(chosen_name, mdfd);
 		if (st->ss->external)
 			strcpy(devnm, fd2devnm(mdfd));
 		if (st->ss->load_container)
 			rv = st->ss->load_container(st, mdfd, NULL);
-		close(mdfd);
-		udev_unblock();
-		sysfs_uevent(sra, "change");
+		if (udev_blocked)
+			udev_ready(sra);
 		sysfs_free(sra);
 		if (!rv)
 			rv = Incremental_container(st, chosen_name, c, NULL);
@@ -485,7 +486,8 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 		 * so that it can eg. try to rebuild degraded array */
 		if (st->ss->external)
 			ping_monitor(devnm);
-		udev_unblock();
+		wait_for(chosen_name, mdfd);
+		close(mdfd);
 		return rv;
 	}
 
@@ -604,8 +606,7 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 			} else if (c->verbose >= 0)
 				pr_err("%s attached to %s, which has been started.\n",
 				       devname, chosen_name);
-			rv = 0;
-			wait_for(chosen_name, mdfd);
+			array_started = true;
 			/* We just started the array, so some devices
 			 * might have been evicted from the array
 			 * because their event counts were too old.
@@ -638,15 +639,19 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 	free(avail);
 	if (dfd >= 0)
 		close(dfd);
-	if (mdfd >= 0)
-		close(mdfd);
 	if (policy)
 		dev_policy_free(policy);
-	udev_unblock();
-	if (sra) {
-		sysfs_uevent(sra, "change");
-		sysfs_free(sra);
+	if (udev_blocked) {
+		if (sra)
+			udev_ready(sra);
+		else
+			udev_unblock();
 	}
+	sysfs_free(sra);
+	if (array_started)
+		wait_for(chosen_name, mdfd);
+	if (mdfd >= 0)
+		close(mdfd);
 	return rv;
 out_unlock:
 	map_unlock(&map);
@@ -1531,6 +1536,7 @@ static int Incremental_container(struct supertype *st, char *devname,
 		char *sysname;
 		struct map_ent *mp;
 		struct mddev_ident *match = NULL;
+		bool udev_blocked = false;
 
 		/* do not activate arrays blocked by metadata handler */
 		if (ra->array.state & (1 << MD_SB_BLOCK_VOLUME)) {
@@ -1601,8 +1607,9 @@ static int Incremental_container(struct supertype *st, char *devname,
 			if (match)
 				trustworthy = LOCAL;
 
+			udev_blocked = udev_is_available();
 			mdfd = create_mddev(match ? match->devname : NULL, ra->name, trustworthy,
-					    chosen_name, 1);
+					    chosen_name, udev_blocked);
 
 			if (!is_fd_valid(mdfd)) {
 				pr_err("create_mddev failed with chosen name %s: %s.\n",
@@ -1613,6 +1620,8 @@ static int Incremental_container(struct supertype *st, char *devname,
 		}
 
 		if (only && (!mp || strcmp(mp->devnm, only) != 0)) {
+			if (udev_blocked)
+				udev_unblock();
 			close_fd(&mdfd);
 			continue;
 		}
@@ -1624,8 +1633,8 @@ static int Incremental_container(struct supertype *st, char *devname,
 		sysname = fd2devnm(mdfd);
 		strncpy(info.sys_name, sysname, sizeof(sysname) - 1);
 		close_fd(&mdfd);
-		udev_unblock();
-		sysfs_uevent(&info, "change");
+		if (udev_blocked)
+			udev_ready(&info);
 	}
 	if (c->export && result) {
 		char sep = '=';
@@ -1652,8 +1661,6 @@ static int Incremental_container(struct supertype *st, char *devname,
 release:
 	map_free(map);
 	sysfs_free(list);
-	udev_unblock();
-	sysfs_uevent(&info, "change");
 	return rv;
 }
 
diff --git a/mdopen.c b/mdopen.c
index 9af0284b..f0e344d5 100644
--- a/mdopen.c
+++ b/mdopen.c
@@ -135,9 +135,6 @@ int create_mddev(char *dev, char *name, int trustworthy,
 		return -1;
 	}
 
-	if (!udev_is_available())
-		block_udev = 0;
-
 	if (chosen == NULL)
 		chosen = cbuf;
 
@@ -273,7 +270,8 @@ int create_mddev(char *dev, char *name, int trustworthy,
 			return -1;
 		if (!create_named_array(devnm)) {
 			devnm[0] = 0;
-			udev_unblock();
+			if (block_udev)
+				udev_unblock();
 		}
 	}
 	if (num >= 0) {
@@ -282,7 +280,8 @@ int create_mddev(char *dev, char *name, int trustworthy,
 			return -1;
 		if (!create_named_array(devnm)) {
 			devnm[0] = 0;
-			udev_unblock();
+			if (block_udev)
+				udev_unblock();
 		}
 	}
 	if (devnm[0] == 0) {
@@ -327,14 +326,14 @@ int create_mddev(char *dev, char *name, int trustworthy,
 			    stb.st_rdev != devnm2devid(devnm)) {
 				pr_err("%s exists but looks wrong, please fix\n",
 					devname);
-				return -1;
+				goto error;
 			}
 		} else {
 			if (mknod(devname, S_IFBLK|0600,
 				  devnm2devid(devnm)) != 0) {
 				pr_err("failed to create %s\n",
 					devname);
-				return -1;
+				goto error;
 			}
 			if (chown(devname, ci->uid, ci->gid))
 				perror("chown");
@@ -343,7 +342,7 @@ int create_mddev(char *dev, char *name, int trustworthy,
 			if (stat(devname, &stb) < 0) {
 				pr_err("failed to stat %s\n",
 						devname);
-				return -1;
+				goto error;
 			}
 			add_dev(devname, &stb, 0, NULL);
 		}
@@ -379,10 +378,17 @@ int create_mddev(char *dev, char *name, int trustworthy,
 		}
 	}
 	mdfd = open_dev_excl(devnm);
-	if (mdfd < 0)
+	if (mdfd < 0) {
 		pr_err("unexpected failure opening %s\n",
 			devname);
+		goto error;
+	}
 	return mdfd;
+
+error:
+	if (block_udev)
+		udev_unblock();
+	return -1;
 }
 
 /* Open this and check that it is an md device.
diff --git a/udev.c b/udev.c
index f857c723..ce2d4850 100644
--- a/udev.c
+++ b/udev.c
@@ -197,8 +197,24 @@ enum udev_status udev_block(char *devnm)
  */
 void udev_unblock(void)
 {
-	if (unblock_path)
-		unlink(unblock_path);
+	if (!unblock_path) {
+		pr_err("Called without prior udev block.\n");
+		return;
+	}
+
+	unlink(unblock_path);
 	free(unblock_path);
 	unblock_path = NULL;
 }
+
+/*
+ * udev_ready() - Unblock udev and signal that the device is ready.
+ *
+ * Removes the blocking file and sends a synthetic change uevent
+ * so udev re-evaluates the device in its final state.
+ */
+void udev_ready(struct mdinfo *sra)
+{
+	udev_unblock();
+	sysfs_uevent(sra, "change");
+}
diff --git a/udev.h b/udev.h
index ae0a3617..db2ef1d3 100644
--- a/udev.h
+++ b/udev.h
@@ -36,5 +36,6 @@ enum udev_status udev_wait_for_events(int seconds);
 
 enum udev_status udev_block(char *devnm);
 void udev_unblock(void);
+void udev_ready(struct mdinfo *sra);
 
 #endif