diff --git a/Assemble.c b/Assemble.c
index d6beb23..a9442c8 100644
--- a/Assemble.c
+++ b/Assemble.c
@@ -1478,7 +1478,7 @@ try_again:
 			name = strchr(name, ':')+1;
 
 		mdfd = create_mddev(mddev, name, ident->autof, trustworthy,
-				    chosen_name);
+				    chosen_name, 0);
 	}
 	if (mdfd < 0) {
 		st->ss->free_super(st);
diff --git a/Build.c b/Build.c
index 11ba12f..665d906 100644
--- a/Build.c
+++ b/Build.c
@@ -109,7 +109,7 @@ int Build(char *mddev, struct mddev_dev *devlist,
 	/* We need to create the device.  It can have no name. */
 	map_lock(&map);
 	mdfd = create_mddev(mddev, NULL, c->autof, LOCAL,
-			    chosen_name);
+			    chosen_name, 0);
 	if (mdfd < 0) {
 		map_unlock(&map);
 		return 1;
diff --git a/Create.c b/Create.c
index 6ca0924..df1bc20 100644
--- a/Create.c
+++ b/Create.c
@@ -605,7 +605,7 @@ int Create(struct supertype *st, char *mddev,
 
 	/* We need to create the device */
 	map_lock(&map);
-	mdfd = create_mddev(mddev, name, c->autof, LOCAL, chosen_name);
+	mdfd = create_mddev(mddev, name, c->autof, LOCAL, chosen_name, 1);
 	if (mdfd < 0) {
 		map_unlock(&map);
 		return 1;
@@ -620,6 +620,7 @@ int Create(struct supertype *st, char *mddev,
 			chosen_name);
 		close(mdfd);
 		map_unlock(&map);
+		udev_unblock();
 		return 1;
 	}
 	mddev = chosen_name;
@@ -1053,9 +1054,15 @@ int Create(struct supertype *st, char *mddev,
 		pr_err("not starting array - not enough devices.\n");
 	}
 	close(mdfd);
+	/* Give udev a moment to process the Change event caused
+	 * by the close.
+	 */
+	usleep(100*1000);
+	udev_unblock();
 	return 0;
 
  abort:
+	udev_unblock();
 	map_lock(&map);
  abort_locked:
 	map_remove(&map, fd2devnm(mdfd));
diff --git a/Incremental.c b/Incremental.c
index 66c5b03..4789e36 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -320,7 +320,7 @@ int Incremental(struct mddev_dev *devlist, struct context *c,
 
 		/* Couldn't find an existing array, maybe make a new one */
 		mdfd = create_mddev(match ? match->devname : NULL,
-				    name_to_use, c->autof, trustworthy, chosen_name);
+				    name_to_use, c->autof, trustworthy, chosen_name, 0);
 
 		if (mdfd < 0)
 			goto out_unlock;
@@ -1596,7 +1596,7 @@ static int Incremental_container(struct supertype *st, char *devname,
 					    ra->name,
 					    c->autof,
 					    trustworthy,
-					    chosen_name);
+					    chosen_name, 0);
 		}
 		if (only && (!mp || strcmp(mp->devnm, only) != 0))
 			continue;
diff --git a/Makefile b/Makefile
index 6850696..021d3ad 100644
--- a/Makefile
+++ b/Makefile
@@ -256,8 +256,8 @@ install-man: mdadm.8 md.4 mdadm.conf.5 mdmon.8
 	$(INSTALL) -D -m 644 md.4 $(DESTDIR)$(MAN4DIR)/md.4
 	$(INSTALL) -D -m 644 mdadm.conf.5 $(DESTDIR)$(MAN5DIR)/mdadm.conf.5
 
-install-udev: udev-md-raid-arrays.rules udev-md-raid-assembly.rules
-	@for file in 63-md-raid-arrays.rules 64-md-raid-assembly.rules ; \
+install-udev: udev-md-raid-arrays.rules udev-md-raid-assembly.rules udev-md-raid-creating.rules
+	@for file in 01-md-raid-creating.rules 63-md-raid-arrays.rules 64-md-raid-assembly.rules ; \
 	do sed -e 's,BINDIR,$(BINDIR),g' udev-$${file#??-} > .install.tmp.1 && \
 	   $(ECHO) $(INSTALL) -D -m 644 udev-$${file#??-} $(DESTDIR)$(UDEVDIR)/rules.d/$$file ; \
 	   $(INSTALL) -D -m 644 .install.tmp.1 $(DESTDIR)$(UDEVDIR)/rules.d/$$file ; \
diff --git a/lib.c b/lib.c
index b640634..7e44b1f 100644
--- a/lib.c
+++ b/lib.c
@@ -163,6 +163,35 @@ char *fd2devnm(int fd)
 	return NULL;
 }
 
+/* When we create a new array, we don't want the content to
+ * be immediately examined by udev - it is probably meaningless.
+ * So create /run/mdadm/creating-FOO and expect that a udev
+ * rule will noticed this and act accordingly.
+ */
+static char block_path[] = "/run/mdadm/creating-%s";
+static char *unblock_path = NULL;
+void udev_block(char *devnm)
+{
+	int fd;
+	char *path = NULL;
+
+	xasprintf(&path, block_path, devnm);
+	fd = open(path, O_CREAT|O_RDWR, 0600);
+	if (fd >= 0) {
+		close(fd);
+		unblock_path = path;
+	} else
+		free(path);
+}
+
+void udev_unblock(void)
+{
+	if (unblock_path)
+		unlink(unblock_path);
+	free(unblock_path);
+	unblock_path = NULL;
+}
+
 /*
  * convert a major/minor pair for a block device into a name in /dev, if possible.
  * On the first call, walk /dev collecting name.
diff --git a/mdadm.h b/mdadm.h
index 1bbacfe..6a382a7 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1533,7 +1533,7 @@ extern char *get_md_name(char *devnm);
 extern char DefaultConfFile[];
 
 extern int create_mddev(char *dev, char *name, int autof, int trustworthy,
-			char *chosen);
+			char *chosen, int block_udev);
 /* values for 'trustworthy' */
 #define	LOCAL	1
 #define	LOCAL_ANY 10
@@ -1567,6 +1567,8 @@ extern char *stat2kname(struct stat *st);
 extern char *fd2kname(int fd);
 extern char *stat2devnm(struct stat *st);
 extern char *fd2devnm(int fd);
+extern void udev_block(char *devnm);
+extern void udev_unblock(void);
 
 extern int in_initrd(void);
 
diff --git a/mdopen.c b/mdopen.c
index 82b97fc..099efa0 100644
--- a/mdopen.c
+++ b/mdopen.c
@@ -135,7 +135,7 @@ void make_parts(char *dev, int cnt)
  */
 
 int create_mddev(char *dev, char *name, int autof, int trustworthy,
-		 char *chosen)
+		 char *chosen, int block_udev)
 {
 	int mdfd;
 	struct stat stb;
@@ -147,6 +147,10 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
 	char devname[37];
 	char devnm[32];
 	char cbuf[400];
+
+	if (!use_udev())
+		block_udev = 0;
+
 	if (chosen == NULL)
 		chosen = cbuf;
 
@@ -305,43 +309,53 @@ int create_mddev(char *dev, char *name, int autof, int trustworthy,
 		int fd;
 		int n = -1;
 		sprintf(devnm, "md_%s", cname);
+		if (block_udev)
+			udev_block(devnm);
 		fd = open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
 		if (fd >= 0) {
 			n = write(fd, devnm, strlen(devnm));
 			close(fd);
 		}
-		if (n < 0)
+		if (n < 0) {
 			devnm[0] = 0;
+			udev_unblock();
+		}
 	}
 	if (num >= 0) {
 		int fd;
 		int n = -1;
 		sprintf(devnm, "md%d", num);
+		if (block_udev)
+			udev_block(devnm);
 		fd = open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
 		if (fd >= 0) {
 			n = write(fd, devnm, strlen(devnm));
 			close(fd);
 		}
-		if (n < 0)
+		if (n < 0) {
 			devnm[0] = 0;
+			udev_unblock();
+		}
 	}
-	if (devnm[0])
-		;
-	else if (num < 0) {
-		/* need to choose a free number. */
-		char *_devnm = find_free_devnm(use_mdp);
-		if (_devnm == NULL) {
-			pr_err("No avail md devices - aborting\n");
-			return -1;
-		}
-		strcpy(devnm, _devnm);
-	} else {
-		sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
-		if (mddev_busy(devnm)) {
-			pr_err("%s is already in use.\n",
-				dev);
-			return -1;
+	if (devnm[0] == 0) {
+		if (num < 0) {
+			/* need to choose a free number. */
+			char *_devnm = find_free_devnm(use_mdp);
+			if (_devnm == NULL) {
+				pr_err("No avail md devices - aborting\n");
+				return -1;
+			}
+			strcpy(devnm, _devnm);
+		} else {
+			sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
+			if (mddev_busy(devnm)) {
+				pr_err("%s is already in use.\n",
+				       dev);
+				return -1;
+			}
 		}
+		if (block_udev)
+			udev_block(devnm);
 	}
 
 	sprintf(devname, "/dev/%s", devnm);
diff --git a/udev-md-raid-creating.rules b/udev-md-raid-creating.rules
new file mode 100644
index 0000000..2be466b
--- /dev/null
+++ b/udev-md-raid-creating.rules
@@ -0,0 +1,7 @@
+# do not edit this file, it will be overwritten on update
+# While mdadm is creating an array, it creates a file
+# /run/mdadm/creating-mdXXX.  If that file exists, then
+# the array is not "ready" and we should make sure the
+# content is ignored.
+
+KERNEL=="md*", TEST="/run/mdadm/creating-$kernel", ENV{SYSTEMD_READY}="0"