eject: use libmount context API for umount

libmount provides a context API that can be used to replace
the fork+exec code pattern needed to leverage umount(8).
This does not only simplify the code base but also removes
the concern for signal handling due to a wait(2) call, avoids
forking and allocating additional system resources, reduces
security management and makes the code more consistent as other
functions were already using some libmount functionalities.

Signed-off-by: Christian Goeschel Ndjomouo <cgoesc2@wgu.edu>

diff --git a/sys-utils/eject.c b/sys-utils/eject.c
index 6e0e7cbc824d09244da34424ac83fc8f9ce3e32c..6f708174eca7e59ec280db43aa0c1da7804e94d7 100644 (file)
--- a/sys-utils/eject.c
+++ b/sys-utils/eject.c
@@ -654,41 +654,34 @@ static int eject_tape(int fd)
        return ioctl(fd, MTIOCTOP, &op) >= 0;
 }
 
-
 /* umount a device. */
 static void umount_one(const struct eject_control *ctl, const char *name)
 {
-       int status;
+       int rc;
+       struct libmnt_context *mnt_ctx;
 
        if (!name)
-               return;
+               errx(EXIT_FAILURE, _("missing device/partition path"));
 
        verbose(ctl, _("%s: unmounting"), name);
 
-       switch (fork()) {
-       case 0: /* child */
-               if (drop_permissions() != 0)
-                       err(EXIT_FAILURE, _("drop permissions failed"));
-               if (ctl->p_option)
-                       execl("/bin/umount", "/bin/umount", name, "-n", (char *)NULL);
-               else
-                       execl("/bin/umount", "/bin/umount", name, (char *)NULL);
+       mnt_ctx = mnt_new_context();
+       if (!mnt_ctx)
+               err(EXIT_FAILURE, _("libmount context allocation failed"));
 
-               errexec("/bin/umount");
+       rc = mnt_context_set_target(mnt_ctx, name);
+       if (rc)
+               err(EXIT_FAILURE, _("failed to set libmount context target"));
 
-       case -1:
-               warn( _("unable to fork"));
-               break;
+       if (ctl->p_option)
+               mnt_context_disable_mtab(mnt_ctx, true);
 
-       default: /* parent */
-               if (wait(&status) == -1 || WIFEXITED(status) == 0)
-                       errx(EXIT_FAILURE,
-                            _("unmount of `%s' did not exit normally"), name);
+       rc = mnt_context_umount(mnt_ctx);
+       rc = mnt_context_get_excode(mnt_ctx, rc, NULL, 0);
+       if (rc != MNT_EX_SUCCESS)
+               errx(EXIT_FAILURE, _("unmount of `%s' failed"), name);
 
-               if (WEXITSTATUS(status) != 0)
-                       errx(EXIT_FAILURE, _("unmount of `%s' failed"), name);
-               break;
-       }
+       mnt_free_context(mnt_ctx);
 }
 
 /* Open a device file. */
@@ -872,9 +865,6 @@ int main(int argc, char **argv)
                return EXIT_SUCCESS;
        }
 
-       /* clear any inherited settings */
-       signal(SIGCHLD, SIG_DFL);
-
        if (!ctl.device) {
                ctl.device = mnt_resolve_path(EJECT_DEFAULT_DEVICE, NULL);
                verbose(&ctl, _("using default device `%s'"), ctl.device);