]> git.ipfire.org Git - thirdparty/mdadm.git/blobdiff - mdmon.c
mdmon: remove switch-root functionality.
[thirdparty/mdadm.git] / mdmon.c
diff --git a/mdmon.c b/mdmon.c
index 50c7be6dfbd20a2ac3278e90a8389f00ef3615c0..c590fb20f8a6ddc52a5236d706932419f0a25c07 100644 (file)
--- a/mdmon.c
+++ b/mdmon.c
@@ -113,28 +113,16 @@ static struct superswitch *find_metadata_methods(char *vers)
        return NULL;
 }
 
-static int test_pidfile(char *devname)
-{
-       char path[100];
-       struct stat st;
-
-       sprintf(path, "/var/run/mdadm/%s.pid", devname);
-       return stat(path, &st);
-}
-
-int make_pidfile(char *devname, int o_excl)
+int make_pidfile(char *devname)
 {
        char path[100];
        char pid[10];
        int fd;
        int n;
 
-       if (sigterm)
-               return -1;
-
-       sprintf(path, "/var/run/mdadm/%s.pid", devname);
+       sprintf(path, "%s/%s.pid", pid_dir, devname);
 
-       fd = open(path, O_RDWR|O_CREAT|o_excl, 0600);
+       fd = open(path, O_RDWR|O_CREAT|O_EXCL, 0600);
        if (fd < 0)
                return -errno;
        sprintf(pid, "%d\n", getpid());
@@ -157,29 +145,12 @@ int is_container_member(struct mdstat_ent *mdstat, char *container)
        return 1;
 }
 
-pid_t devname2mdmon(char *devname)
-{
-       char buf[100];
-       pid_t pid = -1;
-       int fd;
-
-       sprintf(buf, "/var/run/mdadm/%s.pid", devname);
-       fd = open(buf, O_RDONLY|O_NOATIME);
-       if (fd < 0)
-               return -1;
-
-       if (read(fd, buf, sizeof(buf)) > 0)
-               sscanf(buf, "%d\n", &pid);
-       close(fd);
-
-       return pid;
-}
-
 static void try_kill_monitor(pid_t pid, char *devname, int sock)
 {
        char buf[100];
        int fd;
-       struct mdstat_ent *mdstat;
+       int n;
+       long fl;
 
        /* first rule of survival... don't off yourself */
        if (pid == getpid())
@@ -191,36 +162,34 @@ static void try_kill_monitor(pid_t pid, char *devname, int sock)
        if (fd < 0)
                return;
 
-       if (read(fd, buf, sizeof(buf)) < 0) {
-               close(fd);
-               return;
-       }
+       n = read(fd, buf, sizeof(buf)-1);
+       buf[sizeof(buf)-1] = 0;
+       close(fd);
 
-       if (!strstr(buf, "mdmon"))
+       if (n < 0 || !strstr(buf, "mdmon"))
                return;
 
        kill(pid, SIGTERM);
 
-       mdstat = mdstat_read(0, 0);
-       for ( ; mdstat; mdstat = mdstat->next)
-               if (is_container_member(mdstat, devname)) {
-                       sprintf(buf, "/dev/%s", mdstat->dev);
-                       WaitClean(buf, sock, 0);
-               }
-       free_mdstat(mdstat);
+       /* Wait for monitor to exit by reading from the socket, after
+        * clearing the non-blocking flag */
+       fl = fcntl(sock, F_GETFL, 0);
+       fl &= ~O_NONBLOCK;
+       fcntl(sock, F_SETFL, fl);
+       read(sock, buf, 100);
 }
 
 void remove_pidfile(char *devname)
 {
        char buf[100];
 
-       if (sigterm)
-               return;
-
-       sprintf(buf, "/var/run/mdadm/%s.pid", devname);
+       sprintf(buf, "%s/%s.pid", pid_dir, devname);
        unlink(buf);
-       sprintf(buf, "/var/run/mdadm/%s.sock", devname);
+       sprintf(buf, "%s/%s.sock", pid_dir, devname);
        unlink(buf);
+       if (strcmp(pid_dir, ALT_RUN) == 0)
+               /* try to clean up when we are finished with this dir */
+               rmdir(pid_dir);
 }
 
 int make_control_sock(char *devname)
@@ -233,7 +202,7 @@ int make_control_sock(char *devname)
        if (sigterm)
                return -1;
 
-       sprintf(path, "/var/run/mdadm/%s.sock", devname);
+       sprintf(path, "%s/%s.sock", pid_dir, devname);
        unlink(path);
        sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
        if (sfd < 0)
@@ -285,32 +254,34 @@ void usage(void)
        exit(2);
 }
 
-int mdmon(char *devname, int devnum, int scan, char *switchroot);
+static int mdmon(char *devname, int devnum, int must_fork, int takeover);
 
 int main(int argc, char *argv[])
 {
        char *container_name = NULL;
-       char *switchroot = NULL;
        int devnum;
        char *devname;
-       int scan = 0;
        int status = 0;
-
-       switch (argc) {
-       case 3:
-               switchroot = argv[2];
-       case 2:
-               container_name = argv[1];
-               break;
-       default:
-               usage();
+       int arg;
+       int all = 0;
+       int takeover = 0;
+
+       for (arg = 1; arg < argc; arg++) {
+               if (strcmp(argv[arg], "--all") == 0 ||
+                   strcmp(argv[arg], "/proc/mdstat") == 0)
+                       all = 1;
+               else if (strcmp(argv[arg], "--takeover") == 0)
+                       takeover = 1;
+               else if (container_name == NULL)
+                       container_name = argv[arg];
+               else
+                       usage();
        }
 
-       if (strcmp(container_name, "/proc/mdstat") == 0) {
+       if (all) {
                struct mdstat_ent *mdstat, *e;
 
                /* launch an mdmon instance for each container found */
-               scan = 1;
                mdstat = mdstat_read(0, 0);
                for (e = mdstat; e; e = e->next) {
                        if (strncmp(e->metadata_version, "external:", 9) == 0 &&
@@ -323,8 +294,8 @@ int main(int argc, char *argv[])
                                        memset(container_name, 0, strlen(container_name));
                                        sprintf(container_name, "%s", devname);
                                }
-                               status |= mdmon(devname, e->devnum, scan,
-                                               switchroot);
+                               status |= mdmon(devname, e->devnum, 1,
+                                               takeover);
                        }
                }
                free_mdstat(mdstat);
@@ -352,10 +323,10 @@ int main(int argc, char *argv[])
                        container_name);
                exit(1);
        }
-       return mdmon(devname, devnum, scan, switchroot);
+       return mdmon(devname, devnum, do_fork(), takeover);
 }
 
-int mdmon(char *devname, int devnum, int scan, char *switchroot)
+static int mdmon(char *devname, int devnum, int must_fork, int takeover)
 {
        int mdfd;
        struct mdinfo *mdi, *di;
@@ -368,30 +339,7 @@ int mdmon(char *devname, int devnum, int scan, char *switchroot)
        pid_t victim = -1;
        int victim_sock = -1;
 
-       dprintf("starting mdmon for %s in %s\n",
-               devname, switchroot ? : "/");
-
-       /* try to spawn mdmon instances from the target file system */
-       if (switchroot && strcmp(switchroot, "/") != 0) {
-               char path[1024];
-               pid_t pid;
-
-               sprintf(path, "%s/sbin/mdmon", switchroot);
-               switch (fork()) {
-               case 0:
-                       execl(path, "mdmon", devname, NULL);
-                       exit(1);
-               case -1:
-                       return 1;
-               default:
-                       pid = wait(&status);
-                       if (pid > -1 && WIFEXITED(status) &&
-                           WEXITSTATUS(status) == 0)
-                               return 0;
-                       else
-                               return 1;
-               }
-       }
+       dprintf("starting mdmon for %s\n", devname);
 
        mdfd = open_dev(devnum);
        if (mdfd < 0) {
@@ -406,7 +354,7 @@ int mdmon(char *devname, int devnum, int scan, char *switchroot)
        }
 
        /* Fork, and have the child tell us when they are ready */
-       if (do_fork() || scan) {
+       if (must_fork) {
                if (pipe(pfd) != 0) {
                        fprintf(stderr, "mdmon: failed to create pipe\n");
                        return 1;
@@ -498,27 +446,20 @@ int mdmon(char *devname, int devnum, int scan, char *switchroot)
        act.sa_handler = SIG_IGN;
        sigaction(SIGPIPE, &act, NULL);
 
-       if (switchroot) {
-               /* we assume we assume that /sys /proc /dev are available in
-                * the new root
-                */
-               victim = devname2mdmon(container->devname);
+       if (takeover) {
+               victim = mdmon_pid(container->devnum);
                victim_sock = connect_monitor(container->devname);
-               if (chroot(switchroot) != 0) {
-                       fprintf(stderr, "mdmon: failed to chroot to '%s': %s\n",
-                               switchroot, strerror(errno));
-                       exit(4);
-               }
        }
 
        ignore = chdir("/");
-       if (victim < 0 && test_pidfile(container->devname) == 0) {
+       if (victim < 0) {
                if (ping_monitor(container->devname) == 0) {
                        fprintf(stderr, "mdmon: %s already managed\n",
                                container->devname);
                        exit(3);
-               } else if (victim < 0)
-                       victim = devname2mdmon(container->devname);
+               }
+               /* if there is a pid file, kill whoever is there just in case */
+               victim = mdmon_pid(container->devnum);
        }
        if (container->ss->load_super(container, mdfd, devname)) {
                fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
@@ -535,17 +476,7 @@ int mdmon(char *devname, int devnum, int scan, char *switchroot)
                        getppid());
        close(pfd[1]);
 
-       setsid();
-       close(0);
-       open("/dev/null", O_RDWR);
-       close(1);
-       ignore = dup(0);
-#ifndef DEBUG
-       close(2);
-       ignore = dup(0);
-#endif
-
-       mlockall(MCL_FUTURE);
+       mlockall(MCL_CURRENT | MCL_FUTURE);
 
        if (clone_monitor(container) < 0) {
                fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
@@ -557,6 +488,17 @@ int mdmon(char *devname, int devnum, int scan, char *switchroot)
                try_kill_monitor(victim, container->devname, victim_sock);
                close(victim_sock);
        }
+
+       setsid();
+       close(0);
+       open("/dev/null", O_RDWR);
+       close(1);
+       ignore = dup(0);
+#ifndef DEBUG
+       close(2);
+       ignore = dup(0);
+#endif
+
        do_manager(container);
 
        exit(0);