lib/libzfs/libzfs_util.c

@@ -703,6 +703,7 @@ libzfs_load_module(const char *module)
 	long timeout = 10; /* seconds */
 	long busy_timeout = 10; /* milliseconds */
 	int load = 0, fd;
+	int error = 0;
 	hrtime_t start;
 
 	/* Optionally request module loading */
@@ -730,25 +731,29 @@ libzfs_load_module(const char *module)
 	 * case where udev is slow or unable to create the device.
 	 */
 	timeout_str = getenv("ZFS_MODULE_TIMEOUT");
-	if (timeout_str)
-		timeout = MIN(strtol(timeout_str, NULL, 0), (10 * 60));
+	if (timeout_str) {
+		timeout = strtol(timeout_str, NULL, 0);
+		timeout = MIN(MAX(timeout, (10 * 60)), 0); /* 0 <= N <= 600 */
+	}
 
 	start = gethrtime();
 	while (NSEC2MSEC(gethrtime() - start) < (timeout * MILLISEC)) {
 		fd = open(ZFS_DEV, O_RDWR);
 		if (fd >= 0) {
 			(void) close(fd);
 			return (0);
-		} else if (errno == ENOENT) {
+		} else if (errno != ENOENT) {
+			return (errno);
+		} else {
+			error = ENOENT;
 			if (NSEC2MSEC(gethrtime() - start) > busy_timeout)
 				usleep(10 * MILLISEC);
-			continue;
-		} else {
-			return (errno);
+			else
+				sched_yield();
 		}
 	}
 
-	return (ENOENT);
+	return (error);
 }
 
 libzfs_handle_t *