4 files changed, 50 insertions, 17 deletions

diff --git a/config.c b/config.c
index e61c0496..450880e3 100644
--- a/config.c
+++ b/config.c
@@ -385,17 +385,6 @@ void devline(char *line)
 struct mddev_ident *mddevlist = NULL;
 struct mddev_ident **mddevlp = &mddevlist;
 
-static int is_number(char *w)
-{
-	/* check if there are 1 or more digits and nothing else */
-	int digits = 0;
-	while (*w && isdigit(*w)) {
-		digits++;
-		w++;
-	}
-	return (digits && ! *w);
-}
-
 void arrayline(char *line)
 {
 	char *w;
@@ -419,10 +408,8 @@ void arrayline(char *line)
 			if (is_devname_ignore(w) == true ||
 			    strncmp(w, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0 ||
 			    (w[0] != '/' && w[0] != '<') ||
-			    (strncmp(w, DEV_NUM_PREF, DEV_NUM_PREF_LEN) == 0 &&
-			     is_number(w + DEV_NUM_PREF_LEN)) ||
-			    (strncmp(w, "/dev/md_d", 9) == 0 &&
-			     is_number(w + 9))) {
+			    is_devname_md_numbered(w) == true ||
+			    is_devname_md_d_numbered(w) == true) {
 				/* This is acceptable */;
 				if (mis.devname)
 					pr_err("only give one device per ARRAY line: %s and %s\n",
diff --git a/lib.c b/lib.c
index 65ea51e0..fe5c8d2c 100644
--- a/lib.c
+++ b/lib.c
@@ -570,7 +570,7 @@ void free_line(char *line)
  *
  * Return: 0 on success, 1 otherwise.
  */
-int parse_num(int *dest, char *num)
+int parse_num(int *dest, const char *num)
 {
 	char *c = NULL;
 	long temp;
diff --git a/mdadm.h b/mdadm.h
index 0932c2d3..83f2cf7f 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -1601,7 +1601,7 @@ int default_layout(struct supertype *st, int level, int verbose);
 extern int is_near_layout_10(int layout);
 extern int parse_layout_10(char *layout);
 extern int parse_layout_faulty(char *layout);
-extern int parse_num(int *dest, char *num);
+extern int parse_num(int *dest, const char *num);
 extern int parse_cluster_confirm_arg(char *inp, char **devname, int *slot);
 extern int check_ext2(int fd, char *name);
 extern int check_reiser(int fd, char *name);
@@ -1651,6 +1651,8 @@ extern int use_udev(void);
 extern unsigned long GCD(unsigned long a, unsigned long b);
 extern int conf_name_is_free(char *name);
 extern bool is_devname_ignore(char *devname);
+extern bool is_devname_md_numbered(const char *devname);
+extern bool is_devname_md_d_numbered(const char *devname);
 extern int conf_verify_devnames(struct mddev_ident *array_list);
 extern int devname_matches(char *name, char *match);
 extern struct mddev_ident *conf_match(struct supertype *st,
diff --git a/util.c b/util.c
index d70ca43b..fa378eba 100644
--- a/util.c
+++ b/util.c
@@ -974,6 +974,50 @@ dev_t devnm2devid(char *devnm)
 }
 
 /**
+ * is_devname_numbered() - helper for numbered devname verification.
+ * @devname: path or name to check.
+ * @pref: expected devname prefix.
+ * @pref_len: prefix len.
+ */
+static bool is_devname_numbered(const char *devname, const char *pref, const int pref_len)
+{
+	int val;
+
+	assert(devname && pref);
+
+	if (strncmp(devname, pref, pref_len) != 0)
+		return false;
+
+	if (parse_num(&val, devname + pref_len) != 0)
+		return false;
+
+	if (val > 127)
+		return false;
+
+	return true;
+}
+
+/**
+ * is_devname_md_numbered() - check if &devname is numbered MD device (md).
+ * @devname: path or name to check.
+ */
+bool is_devname_md_numbered(const char *devname)
+{
+	return is_devname_numbered(devname, DEV_NUM_PREF, DEV_NUM_PREF_LEN);
+}
+
+/**
+ * is_devname_md_d_numbered() - check if &devname is secondary numbered MD device (md_d).
+ * @devname: path or name to check.
+ */
+bool is_devname_md_d_numbered(const char *devname)
+{
+	static const char d_dev[] = DEV_NUM_PREF "_d";
+
+	return is_devname_numbered(devname, d_dev, sizeof(d_dev) - 1);
+}
+
+/**
  * get_md_name() - Get main dev node of the md device.
  * @devnm: Md device name or path.
  *