patches/check-mountpoint.patch

Index: b/lib/helper.c
===================================================================
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -139,6 +139,23 @@ void fuse_cmdline_help(void)
 	       "                           allowed (default: 10)\n");
 }
 
+/* In case if fuse daemon exited abnormally (e.g. SIGKILL)
+ * then mountpoint is left in inconsistent state.
+ * This function checks if mountpoint in such state and unmounts it.
+ */
+static int check_mountpoint(const char *mount)
+{
+	struct stat buff;
+	if (stat(mount, &buff) == -1 && errno == ENOTCONN) {
+		fprintf(stderr, "fuse: mountpoint '%s' is in inconsistent state. "
+			"It looks like it was not unmounted correctly. "
+			"Unmounting it now.\n", mount);
+		fuse_kern_unmount(mount, -1);
+		return 1;
+	}
+	return 0;
+}
+
 static int fuse_helper_opt_proc(void *data, const char *arg, int key,
 				struct fuse_args *outargs)
 {
@@ -152,6 +169,7 @@ static int fuse_helper_opt_proc(void *da
 				return fuse_opt_add_opt(&opts->mountpoint, arg);
 			}
 
+			check_mountpoint(arg);
 			char mountpoint[PATH_MAX] = "";
 			if (realpath(arg, mountpoint) == NULL) {
 				fuse_log(FUSE_LOG_ERR,
@@ -245,7 +263,9 @@ int fuse_daemonize(int foreground)
 		case 0:
 			break;
 		default:
-			(void) read(waiter[0], &completed, sizeof(completed));
+			if (read(waiter[0], &completed, sizeof(completed)) == -1) {
+				perror("fuse_daemonize(parent): pipe read");
+			}
 			_exit(0);
 		}
 
@@ -267,7 +287,9 @@ int fuse_daemonize(int foreground)
 
 		/* Propagate completion of daemon initialization */
 		completed = 1;
-		(void) write(waiter[1], &completed, sizeof(completed));
+		if (write(waiter[1], &completed, sizeof(completed)) == -1) {
+			perror("fuse_daemonize(child): pipe write");
+		}
 		close(waiter[0]);
 		close(waiter[1]);
 	} else {
@@ -320,6 +342,7 @@ int fuse_main_real(int argc, char *argv[
 		goto out1;
 	}
 
+	check_mountpoint(opts.mountpoint);
 	if (fuse_mount(fuse,opts.mountpoint) != 0) {
 		res = 4;
 		goto out2;