server: improve pidfile and log handling

[fio.git] / server.c

diff --git a/server.c b/server.c
index cf3a48ef25058288f698cab03471d5810a91ab71..4f9c02310563604c08064209af92567a306acbe6 100644 (file)
--- a/server.c
+++ b/server.c
@@ -525,12 +525,12 @@ out:
        return exitval;
 }
 
-int fio_server_text_output(const char *buf, unsigned int len)
+int fio_server_text_output(const char *buf, size_t len)
 {
        if (server_fd != -1)
                return fio_net_send_cmd(server_fd, FIO_NET_CMD_TEXT, buf, len, 0);
 
-       return fwrite(buf, len, 1, f_err);
+       return log_local_buf(buf, len);
 }
 
 static void convert_io_stat(struct io_stat *dst, struct io_stat *src)
@@ -924,31 +924,93 @@ static void server_signal_handler(void)
        sigaction(SIGTERM, &act, NULL);
 }
 
-int fio_start_server(int daemonize)
+static int check_existing_pidfile(const char *pidfile)
 {
+       struct stat sb;
+       char buf[16];
        pid_t pid;
+       FILE *f;
+
+       if (stat(pidfile, &sb))
+               return 0;
+
+       f = fopen(pidfile, "r");
+       if (!f)
+               return 0;
+
+       if (fread(buf, sb.st_size, 1, f) < 0) {
+               fclose(f);
+               return 1;
+       }
+       fclose(f);
+
+       pid = atoi(buf);
+       if (kill(pid, SIGCONT) < 0)
+               return 0;
+
+       return 1;
+}
+
+static int write_pid(pid_t pid, const char *pidfile)
+{
+       FILE *fpid;
+
+       fpid = fopen(pidfile, "w");
+       if (!fpid) {
+               log_err("fio: failed opening pid file %s\n", pidfile);
+               return 1;
+       }
+
+       fprintf(fpid, "%u\n", (unsigned int) pid);
+       fclose(fpid);
+       return 0;
+}
+
+/*
+ * If pidfile is specified, background us.
+ */
+int fio_start_server(char *pidfile)
+{
+       pid_t pid;
+       int ret;
 
        server_signal_handler();
 
-       if (!daemonize)
+       if (!pidfile)
                return fio_server();
 
-       openlog("fio", LOG_NDELAY|LOG_NOWAIT|LOG_PID, LOG_USER);
+       if (check_existing_pidfile(pidfile)) {
+               log_err("fio: pidfile %s exists and server appears alive\n",
+                                                               pidfile);
+               return -1;
+       }
+
        pid = fork();
        if (pid < 0) {
-               syslog(LOG_ERR, "failed server fork");
+               log_err("fio: failed server fork: %s", strerror(errno));
+               free(pidfile);
                return -1;
-       } else if (pid)
-               exit(0);
+       } else if (pid) {
+               int ret = write_pid(pid, pidfile);
+
+               exit(ret);
+       }
 
        setsid();
+       openlog("fio", LOG_NDELAY|LOG_NOWAIT|LOG_PID, LOG_USER);
+       log_syslog = 1;
        close(STDIN_FILENO);
        close(STDOUT_FILENO);
        close(STDERR_FILENO);
        f_out = NULL;
        f_err = NULL;
-       log_syslog = 1;
-       return fio_server();
+
+       ret = fio_server();
+
+       closelog();
+       unlink(pidfile);
+       free(pidfile);
+       return ret;
 }
 
 void fio_server_set_arg(const char *arg)