- char hdb_lock_buffer[12];
- int fd, pid, n;
- char *p;
-
- if ((p = strrchr(dev, '/')) != NULL)
- dev = p + 1;
- lock_file = malloc(strlen(LOCK_PREFIX) + strlen(dev) + 1);
- if (lock_file == NULL)
- novm("lock file name");
- strcat(strcpy(lock_file, LOCK_PREFIX), dev);
-
- while ((fd = open(lock_file, O_EXCL | O_CREAT | O_RDWR, 0644)) < 0) {
- if (errno == EEXIST
- && (fd = open(lock_file, O_RDONLY, 0)) >= 0) {
- /* Read the lock file to find out who has the device locked */
-#ifdef PIDSTRING
- n = read(fd, hdb_lock_buffer, 11);
- if (n > 0) {
- hdb_lock_buffer[n] = 0;
- pid = atoi(hdb_lock_buffer);
- }
-#else
- n = read(fd, &pid, sizeof(pid));
-#endif
- if (n <= 0) {
- syslog(LOG_ERR, "Can't read pid from lock file %s", lock_file);
- close(fd);
- } else {
- if (kill(pid, 0) == -1 && errno == ESRCH) {
- /* pid no longer exists - remove the lock file */
- if (unlink(lock_file) == 0) {
- close(fd);
- syslog(LOG_NOTICE, "Removed stale lock on %s (pid %d)",
- dev, pid);
- continue;
- } else
- syslog(LOG_WARNING, "Couldn't remove stale lock on %s",
- dev);
- } else
- syslog(LOG_NOTICE, "Device %s is locked by pid %d",
- dev, pid);
- }
- close(fd);
- } else
- syslog(LOG_ERR, "Can't create lock file %s: %m", lock_file);
- free(lock_file);
- lock_file = NULL;
- return -1;
- }