From a6727ed6659f287eb2a4f68ac5fbf3178f40498f Mon Sep 17 00:00:00 2001 From: Andre Noll Date: Mon, 12 May 2008 20:29:34 +0200 Subject: [PATCH] Implement exit-hooks. --- dss.c | 107 +++++++++++++++++++++++++++++++++----------------------- dss.ggo | 16 +++++++++ error.h | 5 ++- 3 files changed, 83 insertions(+), 45 deletions(-) diff --git a/dss.c b/dss.c index 49be348..b27bdf6 100644 --- a/dss.c +++ b/dss.c @@ -77,7 +77,7 @@ static int call_command_handler(void) { COMMANDS DSS_EMERG_LOG("BUG: did not find command handler\n"); - exit(EXIT_FAILURE); + return -E_BUG; } #undef COMMAND #undef COMMANDS @@ -558,7 +558,7 @@ static int handle_sigchld(void) return 1; } DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid); - exit(EXIT_FAILURE); + return -E_BUG; } static int check_config(void) @@ -576,8 +576,7 @@ static int check_config(void) return 1; } -/* exits on errors */ -static void parse_config_file(int override) +static int parse_config_file(int override) { int ret; char *config_file; @@ -633,36 +632,33 @@ static void parse_config_file(int override) logfile = open_log(conf.logfile_arg); log_welcome(conf.loglevel_arg); } - DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg); + DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg); // cmdline_parser_dump(logfile? logfile : stdout, &conf); out: free(config_file); - if (ret >= 0) - return; - DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); - exit(EXIT_FAILURE); + if (ret < 0) + DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); + return ret; } -static void change_to_dest_dir(void) +static int change_to_dest_dir(void) { - int ret; - DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg); - ret = dss_chdir(conf.dest_dir_arg); - if (ret >= 0) - return; - DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); - exit(EXIT_FAILURE); + return dss_chdir(conf.dest_dir_arg); } -static void handle_sighup(void) +static int handle_sighup(void) { + int ret; + DSS_NOTICE_LOG("SIGHUP\n"); - parse_config_file(1); - change_to_dest_dir(); + ret = parse_config_file(1); + if (ret < 0) + return ret; + return change_to_dest_dir(); } -static void handle_signal(void) +static int handle_signal(void) { int sig, ret = next_signal(); @@ -675,10 +671,10 @@ static void handle_signal(void) restart_rsync_process(); kill_process(rsync_pid); kill_process(rm_pid); - exit(EXIT_FAILURE); + ret = -E_SIGNAL; + break; case SIGHUP: - handle_sighup(); - ret = 1; + ret = handle_sighup(); break; case SIGCHLD: ret = handle_sigchld(); @@ -687,6 +683,7 @@ static void handle_signal(void) out: if (ret < 0) DSS_ERROR_LOG("%s\n", dss_strerror(-ret)); + return ret; } static void create_rsync_argv(char ***argv, int64_t *num) @@ -773,18 +770,21 @@ static int select_loop(void) DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec); ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp); if (ret < 0) - return ret; - if (FD_ISSET(signal_pipe, &rfds)) - handle_signal(); + goto out; + if (FD_ISSET(signal_pipe, &rfds)) { + ret = handle_signal(); + if (ret < 0) + goto out; + } if (rm_pid) continue; ret = disk_space_low(); if (ret < 0) - break; + goto out; low_disk_space = ret; ret = try_to_free_disk_space(low_disk_space); if (ret < 0) - break; + goto out; if (rm_pid) { stop_rsync_process(); continue; @@ -823,6 +823,21 @@ out: return ret; } +static void exit_hook(int exit_code) +{ + int fds[3] = {0, 0, 0}; + char *cmd; + pid_t pid; + + if (!conf.exit_hook_given) + return; + cmd = make_message("%s %s", conf.exit_hook_arg, + dss_strerror(-exit_code)); + DSS_NOTICE_LOG("executing %s\n", cmd); + dss_exec_cmdline_pid(&pid, cmd, fds); + free(cmd); +} + static int com_run(void) { int ret; @@ -835,7 +850,11 @@ static int com_run(void) if (ret < 0) return ret; compute_next_snapshot_time(); - return select_loop(); + ret = select_loop(); + if (ret >= 0) /* impossible */ + ret = -E_BUG; + exit_hook(ret); + return ret; } static int com_prune(void) @@ -939,7 +958,7 @@ static int com_ls(void) return 1; } -static void setup_signal_handling(void) +static int setup_signal_handling(void) { int ret; @@ -947,17 +966,11 @@ static void setup_signal_handling(void) signal_pipe = signal_init(); /* always successful */ ret = install_sighandler(SIGINT); if (ret < 0) - goto err; + return ret; ret = install_sighandler(SIGTERM); if (ret < 0) - goto err; - ret = install_sighandler(SIGCHLD); - if (ret < 0) - goto err; - return; -err: - DSS_EMERG_LOG("could not install signal handlers\n"); - exit(EXIT_FAILURE); + return ret; + return install_sighandler(SIGCHLD); } /** @@ -978,13 +991,19 @@ int main(int argc, char **argv) }; cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */ - parse_config_file(0); - + ret = parse_config_file(0); + if (ret < 0) + goto out; if (conf.daemon_given) daemon_init(); - change_to_dest_dir(); - setup_signal_handling(); + ret = change_to_dest_dir(); + if (ret < 0) + goto out; + ret = setup_signal_handling(); + if (ret < 0) + goto out; ret = call_command_handler(); +out: if (ret < 0) DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE); diff --git a/dss.ggo b/dss.ggo index 4ff2a6c..fc52bee 100644 --- a/dss.ggo +++ b/dss.ggo @@ -273,6 +273,22 @@ details=" store them in a database for further analysis. " +option "exit-hook" e +#~~~~~~~~~~~~~~~~~~~ +"Executed if run command exits" +string typestr="command" +optional +details=" + This hook is only used if the --run command was given which + instructs dss to run in an endless loop. The exit-hook gets + executed whenever this endless loop terminates. The reason + for terminating the loop is passed as the first argument. + + One possible application for this hook is to send email to the + system administrator to let her know that no more snapshots + are going to be created. +" + ############################### section "Disk space monitoring" ############################### diff --git a/error.h b/error.h index 6cb5deb..286db0e 100644 --- a/error.h +++ b/error.h @@ -65,7 +65,10 @@ static inline char *dss_strerror(int num) DSS_ERROR(DUP_PIPE, "exec error: can not create pipe") \ DSS_ERROR(INVOLUNTARY_EXIT, "unexpected termination cause") \ DSS_ERROR(BAD_EXIT_CODE, "unexpected exit code") \ - DSS_ERROR(SIGNAL_SIG_ERR, "signal() returned SIG_ERR") + DSS_ERROR(SIGNAL_SIG_ERR, "signal() returned SIG_ERR") \ + DSS_ERROR(SIGNAL, "caught terminating signal") \ + DSS_ERROR(BUG, "values of beta might cause dom!") \ + /** * This is temporarily defined to expand to its first argument (prefixed by -- 2.39.2