Spawn mdmon with --offroot if mdadm was launched with --offroot

Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

mdadm.c

@@ -181,6 +181,7 @@ int main(int argc, char *argv[])
 		 */
 		case OffRootOpt:
 			argv[0][0] = '@';
+			__offroot = 1;
 			continue;
 
 		case ':':

mdadm.h

@@ -1383,3 +1383,5 @@ static inline int xasprintf(char **strp, const char *fmt, ...) {
 
 #define PROCESS_DELAYED -2
 #define PROCESS_PENDING -3
+
+extern int __offroot;

util.c

@@ -32,6 +32,8 @@
 #include	<dirent.h>
 #include	<signal.h>
 
+int __offroot;
+
 /*
  * following taken from linux/blkpg.h because they aren't
  * anywhere else and it isn't safe to #include linux/ * stuff.
@@ -1622,10 +1624,17 @@ int start_mdmon(int devnum)
 				skipped = 0;
 
 		for (i=0; paths[i]; i++)
-			if (paths[i][0])
-				execl(paths[i], "mdmon",
-				      devnum2devname(devnum),
-				      NULL);
+			if (paths[i][0]) {
+				if (__offroot) {
+					execl(paths[i], "mdmon", "--offroot",
+					      devnum2devname(devnum),
+					      NULL);
+				} else {
+					execl(paths[i], "mdmon",
+					      devnum2devname(devnum),
+					      NULL);
+				}
+			}
 		exit(1);
 	case -1: fprintf(stderr, Name ": cannot run mdmon. "
 			 "Array remains readonly\n");