diff options
| -rw-r--r-- | cmd/zed/zed.c | 3 | ||||
| -rw-r--r-- | cmd/zed/zed_conf.c | 107 | ||||
| -rw-r--r-- | cmd/zed/zed_conf.h | 1 |
3 files changed, 78 insertions, 33 deletions
diff --git a/cmd/zed/zed.c b/cmd/zed/zed.c index b8dbc442c..2205f7367 100644 --- a/cmd/zed/zed.c +++ b/cmd/zed/zed.c @@ -259,7 +259,8 @@ main(int argc, char *argv[]) if (zcp->do_memlock) _lock_memory(); - (void) zed_conf_write_pid(zcp); + if ((zed_conf_write_pid(zcp) < 0) && (!zcp->do_force)) + exit(EXIT_FAILURE); if (!zcp->do_foreground) _finish_daemonize(); diff --git a/cmd/zed/zed_conf.c b/cmd/zed/zed_conf.c index 5e21a3db9..3f38945c0 100644 --- a/cmd/zed/zed_conf.c +++ b/cmd/zed/zed_conf.c @@ -58,6 +58,7 @@ zed_conf_create(void) zcp->syslog_facility = LOG_DAEMON; zcp->min_events = ZED_MIN_EVENTS; zcp->max_events = ZED_MAX_EVENTS; + zcp->pid_fd = -1; zcp->zedlets = NULL; /* created via zed_conf_scan_dir() */ zcp->state_fd = -1; /* opened via zed_conf_open_state() */ zcp->zfs_hdl = NULL; /* opened via zed_event_init() */ @@ -105,6 +106,13 @@ zed_conf_destroy(struct zed_conf *zcp) "Failed to remove PID file \"%s\": %s", zcp->pid_file, strerror(errno)); } + if (zcp->pid_fd >= 0) { + if (close(zcp->pid_fd) < 0) + zed_log_msg(LOG_WARNING, + "Failed to close PID file \"%s\": %s", + zcp->pid_file, strerror(errno)); + zcp->pid_fd = -1; + } if (zcp->conf_file) free(zcp->conf_file); @@ -437,65 +445,101 @@ zed_conf_scan_dir(struct zed_conf *zcp) * This must be called after fork()ing to become a daemon (so the correct PID * is recorded), but before daemonization is complete and the parent process * exits (for synchronization with systemd). - * - * FIXME: Only update the PID file after verifying the PID previously stored - * in the PID file no longer exists or belongs to a foreign process - * in order to ensure the daemon cannot be started more than once. - * (This check is currently done by zed_conf_open_state().) */ int zed_conf_write_pid(struct zed_conf *zcp) { - char dirbuf[PATH_MAX]; - mode_t dirmode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; + const mode_t dirmode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; + const mode_t filemode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; + char buf[PATH_MAX]; int n; char *p; mode_t mask; - FILE *fp; + int rv; if (!zcp || !zcp->pid_file) { errno = EINVAL; - zed_log_msg(LOG_ERR, "Failed to write PID file: %s", + zed_log_msg(LOG_ERR, "Failed to create PID file: %s", strerror(errno)); return (-1); } - n = strlcpy(dirbuf, zcp->pid_file, sizeof (dirbuf)); - if (n >= sizeof (dirbuf)) { + assert(zcp->pid_fd == -1); + /* + * Create PID file directory if needed. + */ + n = strlcpy(buf, zcp->pid_file, sizeof (buf)); + if (n >= sizeof (buf)) { errno = ENAMETOOLONG; - zed_log_msg(LOG_WARNING, "Failed to write PID file: %s", + zed_log_msg(LOG_ERR, "Failed to create PID file: %s", strerror(errno)); - return (-1); + goto err; } - p = strrchr(dirbuf, '/'); + p = strrchr(buf, '/'); if (p) *p = '\0'; - if ((mkdirp(dirbuf, dirmode) < 0) && (errno != EEXIST)) { - zed_log_msg(LOG_WARNING, - "Failed to create directory \"%s\": %s", - dirbuf, strerror(errno)); - return (-1); + if ((mkdirp(buf, dirmode) < 0) && (errno != EEXIST)) { + zed_log_msg(LOG_ERR, "Failed to create directory \"%s\": %s", + buf, strerror(errno)); + goto err; } - (void) unlink(zcp->pid_file); - + /* + * Obtain PID file lock. + */ mask = umask(0); umask(mask | 022); - fp = fopen(zcp->pid_file, "w"); + zcp->pid_fd = open(zcp->pid_file, (O_RDWR | O_CREAT), filemode); umask(mask); - - if (!fp) { - zed_log_msg(LOG_WARNING, "Failed to open PID file \"%s\": %s", + if (zcp->pid_fd < 0) { + zed_log_msg(LOG_ERR, "Failed to open PID file \"%s\": %s", + zcp->pid_file, strerror(errno)); + goto err; + } + rv = zed_file_lock(zcp->pid_fd); + if (rv < 0) { + zed_log_msg(LOG_ERR, "Failed to lock PID file \"%s\": %s", + zcp->pid_file, strerror(errno)); + goto err; + } else if (rv > 0) { + pid_t pid = zed_file_is_locked(zcp->pid_fd); + if (pid < 0) { + zed_log_msg(LOG_ERR, + "Failed to test lock on PID file \"%s\"", + zcp->pid_file); + } else if (pid > 0) { + zed_log_msg(LOG_ERR, + "Found PID %d bound to PID file \"%s\"", + pid, zcp->pid_file); + } else { + zed_log_msg(LOG_ERR, + "Inconsistent lock state on PID file \"%s\"", + zcp->pid_file); + } + goto err; + } + /* + * Write PID file. + */ + n = snprintf(buf, sizeof (buf), "%d\n", (int) getpid()); + if ((n < 0) || (n >= sizeof (buf))) { + errno = ERANGE; + zed_log_msg(LOG_ERR, "Failed to write PID file \"%s\": %s", zcp->pid_file, strerror(errno)); - } else if (fprintf(fp, "%d\n", (int) getpid()) == EOF) { - zed_log_msg(LOG_WARNING, "Failed to write PID file \"%s\": %s", + } else if (zed_file_write_n(zcp->pid_fd, buf, n) != n) { + zed_log_msg(LOG_ERR, "Failed to write PID file \"%s\": %s", zcp->pid_file, strerror(errno)); - } else if (fclose(fp) == EOF) { - zed_log_msg(LOG_WARNING, "Failed to close PID file \"%s\": %s", + } else if (fdatasync(zcp->pid_fd) < 0) { + zed_log_msg(LOG_ERR, "Failed to sync PID file \"%s\": %s", zcp->pid_file, strerror(errno)); } else { return (0); } - (void) unlink(zcp->pid_file); + +err: + if (zcp->pid_fd >= 0) { + (void) close(zcp->pid_fd); + zcp->pid_fd = -1; + } return (-1); } @@ -503,8 +547,7 @@ zed_conf_write_pid(struct zed_conf *zcp) * Open and lock the [zcp] state_file. * Return 0 on success, -1 on error. * - * FIXME: If state_file exists, verify ownership & permissions. - * FIXME: Move lock to pid_file instead. + * FIXME: Move state information into kernel. */ int zed_conf_open_state(struct zed_conf *zcp) diff --git a/cmd/zed/zed_conf.h b/cmd/zed/zed_conf.h index 126075842..20e04039b 100644 --- a/cmd/zed/zed_conf.h +++ b/cmd/zed/zed_conf.h @@ -42,6 +42,7 @@ struct zed_conf { int max_events; /* RESERVED FOR FUTURE USE */ char *conf_file; /* abs path to config file */ char *pid_file; /* abs path to pid file */ + int pid_fd; /* fd to pid file for lock */ char *zedlet_dir; /* abs path to zedlet dir */ zed_strings_t *zedlets; /* names of enabled zedlets */ char *state_file; /* abs path to state file */ |