fusermount: Added support for auto_unmount option

When this option is specified fusermount will become a daemon and wait for the
parent to exit or die, which causes control fd to get closed. It will then try
to unmount the original mountpoint.

diff --git a/util/fusermount.c b/util/fusermount.c
index 85292fb28e294d7dd1598e939f32b03d7b8a54ee..21e55f1c8802023edf5189a81c5c5c285881f8c1 100644 (file)
--- a/util/fusermount.c
+++ b/util/fusermount.c
@@ -60,6 +60,8 @@ static const char *progname;
 static int user_allow_other = 0;
 static int mount_max = 1000;
 
+static int auto_unmount = 0;
+
 static const char *get_user_name(void)
 {
        struct passwd *pw = getpwuid(getuid());
@@ -746,6 +748,8 @@ static int do_mount(const char *mnt, char **typep, mode_t rootmode,
                        blkdev = 1;
                } else if (opt_eq(s, len, "nonempty")) {
                        check_empty = 0;
+               } else if (opt_eq(s, len, "auto_unmount")) {
+                       auto_unmount = 1;
                } else if (!begins_with(s, "fd=") &&
                           !begins_with(s, "rootmode=") &&
                           !begins_with(s, "user_id=") &&
@@ -1158,6 +1162,7 @@ static void show_version(void)
 
 int main(int argc, char *argv[])
 {
+       sigset_t sigset;
        int ch;
        int fd;
        int res;
@@ -1246,20 +1251,8 @@ int main(int argc, char *argv[])
                exit(1);
 
        umask(033);
-       if (unmount) {
-               if (geteuid() == 0)
-                       res = unmount_fuse(mnt, quiet, lazy);
-               else {
-                       res = umount2(mnt, lazy ? UMOUNT_DETACH : 0);
-                       if (res == -1 && !quiet)
-                               fprintf(stderr,
-                                       "%s: failed to unmount %s: %s\n",
-                                       progname, mnt, strerror(errno));
-               }
-               if (res == -1)
-                       exit(1);
-               return 0;
-       }
+       if (unmount)
+               goto do_unmount;
 
        commfd = getenv(FUSE_COMMFD_ENV);
        if (commfd == NULL) {
@@ -1276,6 +1269,48 @@ int main(int argc, char *argv[])
        res = send_fd(cfd, fd);
        if (res == -1)
                exit(1);
+       close(fd);
+
+       if (!auto_unmount)
+               return 0;
+
+       /* Decome a daemon and wait for the parent to exit or die.
+          ie For the control socket to get closed. 
+          btw We don't want to use daemon() function here because
+          it forks and messes with the file descriptors. */
+       setsid();
+       chdir("/");
+
+       sigfillset(&sigset);
+       sigprocmask(SIG_BLOCK, &sigset, NULL);
 
+       lazy  = 1;
+       quiet = 1;
+
+       while (1) {
+               unsigned char buf[16];
+               int n = recv(cfd, buf, sizeof(buf), 0);
+               if (!n)
+                       break;
+
+               if (n < 0) {
+                       if (errno == EINTR)
+                               continue;
+                       break;
+               }
+       }
+
+do_unmount:
+       if (geteuid() == 0)
+               res = unmount_fuse(mnt, quiet, lazy);
+       else {
+               res = umount2(mnt, lazy ? UMOUNT_DETACH : 0);
+               if (res == -1 && !quiet)
+                       fprintf(stderr,
+                               "%s: failed to unmount %s: %s\n",
+                               progname, mnt, strerror(errno));
+       }
+       if (res == -1)
+               exit(1);
        return 0;
 }