Allow homehost to be largely ignored when assembling arrays.

If mdadm.conf contains
   HOMEHOST <ignore>
or commandline contains
   --homehost=<ignore>

then the check that array metadata mentions the given homehost is
replace by a check that the name recorded in the metadata is not
already used by some other array mentioned in mdadm.conf.

This allows more arrays to use their native name rather than having
an _NN suffix added.

This should only be used during boot time if all arrays required for
normal boot are listed in mdadm.conf.

If auto-assembly is used to find all array during boot, then the
HOMEHOST feature should be used to ensure there is no room for
confusion in choosing array names, and so it should not be set
to <ignore>.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 62 insertions, 2 deletions

diff --git a/config.c b/config.c
index 41428ae9..284896ed 100644
--- a/config.c
+++ b/config.c
@@ -663,12 +663,15 @@ void programline(char *line)
 }
 
 static char *home_host = NULL;
+static int require_homehost = 1;
 void homehostline(char *line)
 {
 	char *w;
 
 	for (w=dl_next(line); w != line ; w=dl_next(w)) {
-		if (home_host == NULL)
+		if (strcasecmp(w, "<ignore>")==0)
+			require_homehost = 0;
+		else if (home_host == NULL)
 			home_host = strdup(w);
 		else
 			fprintf(stderr, Name ": excess host name on HOMEHOST line: %s - ignored\n",
@@ -788,9 +791,11 @@ char *conf_get_program(void)
 	return alert_program;
 }
 
-char *conf_get_homehost(void)
+char *conf_get_homehost(int *require_homehostp)
 {
 	load_conffile();
+	if (require_homehostp)
+		*require_homehostp = require_homehost;
 	return home_host;
 }
 
@@ -953,3 +958,58 @@ int match_oneof(char *devices, char *devname)
     }
     return 0;
 }
+
+int devname_matches(char *name, char *match)
+{
+	/* See if the given array name matches the
+	 * given match from config file.
+	 *
+	 * First strip and /dev/md/ or /dev/, then
+	 * see if there might be a numeric match of
+	 *  mdNN with NN
+	 * then just strcmp
+	 */
+	if (strncmp(name, "/dev/md/", 8) == 0)
+		name += 8;
+	else if (strncmp(name, "/dev/", 5) == 0)
+		name += 5;
+
+	if (strncmp(match, "/dev/md/", 8) == 0)
+		match += 8;
+	else if (strncmp(match, "/dev/", 5) == 0)
+		match += 5;
+
+
+	if (strncmp(name, "md", 2) == 0 &&
+	    isdigit(name[2]))
+		name += 2;
+	if (strncmp(match, "md", 2) == 0 &&
+	    isdigit(match[2]))
+		match += 2;
+
+	return (strcmp(name, match) == 0);
+}
+
+int conf_name_is_free(char *name)
+{
+	/* Check if this name is already take by an ARRAY entry in
+	 * the config file.
+	 * It can be taken either by a match on devname, name, or
+	 * even super-minor.
+	 */
+	mddev_ident_t dev;
+
+	load_conffile();
+	for (dev = mddevlist; dev; dev = dev->next) {
+		char nbuf[100];
+		if (dev->devname && devname_matches(name, dev->devname))
+			return 0;
+		if (dev->name[0] && devname_matches(name, dev->name))
+			return 0;
+		sprintf(nbuf, "%d", dev->super_minor);
+		if (dev->super_minor != UnSet &&
+		    devname_matches(name, nbuf))
+			return 0;
+	}
+	return 1;
+}