+static void to_devnull(int fd)
+{
+ int devnull = open("/dev/null", fd ? O_WRONLY : O_RDONLY);
+
+ if (devnull >= 0)
+ dup2(devnull, fd);
+
+ if (devnull > STDERR_FILENO)
+ close(devnull);
+}
+
+static int exec_mount(const char *source, const char *target,
+ const char *fstype, const char *options)
+{
+ pid_t pid;
+ struct stat s;
+ FILE *mount_fd;
+ int err, status, pfds[2];
+ char errmsg[128], cmd[sizeof("/sbin/mount.XXXXXXXXXXXXXXXX\0")];
+
+ snprintf(cmd, sizeof(cmd), "/sbin/mount.%s", fstype);
+
+ if (stat(cmd, &s) < 0 || !S_ISREG(s.st_mode) || !(s.st_mode & S_IXUSR)) {
+ ULOG_ERR("No \"mount.%s\" utility available\n", fstype);
+ return -1;
+ }
+
+ if (pipe(pfds) < 0)
+ return -1;
+
+ fcntl(pfds[0], F_SETFD, fcntl(pfds[0], F_GETFD) | FD_CLOEXEC);
+ fcntl(pfds[1], F_SETFD, fcntl(pfds[1], F_GETFD) | FD_CLOEXEC);
+
+ pid = vfork();
+
+ switch (pid) {
+ case -1:
+ close(pfds[0]);
+ close(pfds[1]);
+
+ return -1;
+
+ case 0:
+ to_devnull(STDIN_FILENO);
+ to_devnull(STDOUT_FILENO);
+
+ dup2(pfds[1], STDERR_FILENO);
+ close(pfds[0]);
+ close(pfds[1]);
+
+ if (options && *options)
+ execl(cmd, cmd, "-o", options, source, target, NULL);
+ else
+ execl(cmd, cmd, source, target, NULL);
+
+ return -1;
+
+ default:
+ close(pfds[1]);
+
+ mount_fd = fdopen(pfds[0], "r");
+
+ while (fgets(errmsg, sizeof(errmsg), mount_fd))
+ ULOG_ERR("mount.%s: %s", fstype, errmsg);
+
+ fclose(mount_fd);
+
+ err = waitpid(pid, &status, 0);
+
+ if (err != -1) {
+ if (status != 0) {
+ ULOG_ERR("mount.%s: failed with status %d\n", fstype, status);
+ errno = EINVAL;
+ err = -1;
+ } else {
+ errno = 0;
+ err = 0;
+ }
+ }
+
+ break;
+ }
+
+ return err;
+}
+
+static int handle_mount(const char *source, const char *target,
+ const char *fstype, struct mount *m)
+{
+ int i, err;
+ size_t mount_opts_len;
+ char *mount_opts = NULL, *ptr;
+
+ err = mount(source, target, fstype, m ? m->flags : 0,
+ (m && m->options) ? m->options : "");
+
+ /* Requested file system type is not available in kernel,
+ attempt to call mount helper. */
+ if (err == -1 && errno == ENODEV) {
+ if (m) {
+ /* Convert mount flags back into string representation,
+ first calculate needed length of string buffer... */
+ mount_opts_len = 1 + (m->options ? strlen(m->options) : 0);
+
+ for (i = 0; i < ARRAY_SIZE(mount_flags); i++)
+ if ((mount_flags[i].flag > 0) &&
+ (mount_flags[i].flag < INT_MAX) &&
+ (m->flags & (uint32_t)mount_flags[i].flag))
+ mount_opts_len += strlen(mount_flags[i].name) + 1;
+
+ /* ... then now allocate and fill it ... */
+ ptr = mount_opts = calloc(1, mount_opts_len);
+
+ if (!ptr) {
+ errno = ENOMEM;
+ return -1;
+ }
+
+ if (m->options)
+ ptr += sprintf(ptr, "%s,", m->options);
+
+ for (i = 0; i < ARRAY_SIZE(mount_flags); i++)
+ if ((mount_flags[i].flag > 0) &&
+ (mount_flags[i].flag < INT_MAX) &&
+ (m->flags & (uint32_t)mount_flags[i].flag))
+ ptr += sprintf(ptr, "%s,", mount_flags[i].name);
+
+ mount_opts[mount_opts_len - 1] = 0;
+ }
+
+ /* ... and now finally invoke the external mount program */
+ err = exec_mount(source, target, fstype, mount_opts);
+ }
+
+ return err;
+}
+
projects / project / fstools.git / blobdiff