10.3/mount-try-external-program.diff

Always try external mount programs at first.
Try 'mount.<fstype>' first, then 'mount_<fstype>'.

diff -ru --exclude-from freebsd-src-diff-exclude-names /var/tmp/freebsd-10.3-src/usr/src/sbin/mount/mount.c freebsd-10.3/usr/src/sbin/mount/mount.c
--- /var/tmp/freebsd-10.3-src/usr/src/sbin/mount/mount.c	2016-03-25 09:10:18.000000000 +0800
+++ freebsd-10.3/usr/src/sbin/mount/mount.c	2018-11-07 23:33:33.026775789 +0800
@@ -168,15 +168,12 @@
 	switch (pid = fork()) {
 	case -1:				/* Error. */
 		warn("fork");
-		exit (1);
+		exit(1);
 	case 0:					/* Child. */
 		/* Go find an executable. */
 		execvP(execname, _PATH_SYSPATH, argv);
 		if (errno == ENOENT) {
-			warn("exec %s not found", execname);
-			if (execname[0] != '/') {
-				warnx("in path: %s", _PATH_SYSPATH);
-			}
+			exit(127);
 		}
 		exit(1);
 	default:				/* Parent. */
@@ -591,7 +603,7 @@
 	}
 
 	/* Construct the name of the appropriate mount command */
-	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
+	(void)snprintf(execname, sizeof(execname), "mount.%s", vfstype);
 
 	mnt_argv.c = -1;
 	append_arg(&mnt_argv, execname);
@@ -605,7 +617,7 @@
 
 	if (debug) {
 		if (use_mountprog(vfstype))
-			printf("exec: %s", execname);
+			printf("should exec: %s", execname);
 		else
 			printf("mount -t %s", vfstype);
 		for (i = 1; i < mnt_argv.c; i++)
@@ -617,10 +629,14 @@
 		return (0);
 	}
 
-	if (use_mountprog(vfstype)) {
+	ret = exec_mountprog(name, execname, mnt_argv.a);
+	if(ret == 127) {
+		snprintf(execname, sizeof(execname), "mount_%s", vfstype);
 		ret = exec_mountprog(name, execname, mnt_argv.a);
-	} else {
-		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
+		if(ret == 127) {
+			strcpy(execname, "mount");
+			ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
+		}
 	}
 
 	free(optbuf);