Implement SIGHUP handling.

diff --git a/dss.c b/dss.c
index 4bf01e961ad1d2b3d32313edd70668511f899b37..24ef6ccc83549231252ee093bedded5a911951d0 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -340,7 +340,10 @@ void free_snapshot_list(struct snapshot_list *sl)
                free(s);
        }
        free(sl->interval_count);
+       sl->interval_count = NULL;
        free(sl->snapshots);
+       sl->snapshots = NULL;
+       sl->num_snapshots = 0;
 }
 
 void stop_rsync_process(void)
@@ -546,9 +549,95 @@ void kill_process(pid_t pid)
        kill(pid, SIGTERM);
 }
 
-void handle_sighup()
+int check_config(void)
 {
-       DSS_INFO_LOG("FIXME: no sighup handling yet\n");
+       if (conf.unit_interval_arg <= 0) {
+               make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
+               return -E_INVALID_NUMBER;
+       }
+       DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
+       if (conf.num_intervals_arg <= 0) {
+               make_err_msg("bad number of intervals  %i", conf.num_intervals_arg);
+               return -E_INVALID_NUMBER;
+       }
+       DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
+       return 1;
+}
+
+/* exits on errors */
+void parse_config_file(int override)
+{
+       int ret;
+       char *config_file;
+       struct stat statbuf;
+       char *old_logfile_arg = NULL;
+       int old_daemon_given = 0;
+
+       if (conf.config_file_given)
+               config_file = dss_strdup(conf.config_file_arg);
+       else {
+               char *home = get_homedir();
+               config_file = make_message("%s/.dssrc", home);
+               free(home);
+       }
+       if (override) { /* SIGHUP */
+               if (conf.logfile_given)
+                       old_logfile_arg = dss_strdup(conf.logfile_arg);
+               old_daemon_given = conf.daemon_given;
+       }
+
+       ret = stat(config_file, &statbuf);
+       if (ret && conf.config_file_given) {
+               ret = -ERRNO_TO_DSS_ERROR(errno);
+               make_err_msg("failed to stat config file %s", config_file);
+               goto out;
+       }
+       if (!ret) {
+               struct cmdline_parser_params params = {
+                       .override = override,
+                       .initialize = 0,
+                       .check_required = 0,
+                       .check_ambiguity = 0
+               };
+               cmdline_parser_config_file(config_file, &conf, &params);
+       }
+       if (!conf.source_dir_given || !conf.dest_dir_given) {
+               ret = -E_SYNTAX;
+               make_err_msg("you need to specify both source_dir and dest_dir");
+               goto out;
+       }
+       ret = check_config();
+       if (ret < 0)
+               goto out;
+       if (override) {
+               /* don't change daemon mode on SIGHUP */
+               conf.daemon_given = old_daemon_given;
+               close_log(logfile);
+               logfile = NULL;
+               if (conf.logfile_given)
+                       free(old_logfile_arg);
+               else if (conf.daemon_given) { /* re-use old logfile */
+                       conf.logfile_arg = old_logfile_arg;
+                       conf.logfile_given = 1;
+               }
+       }
+       if (conf.logfile_given) {
+               logfile = open_log(conf.logfile_arg);
+               log_welcome(conf.loglevel_arg);
+       }
+       ret = dss_chdir(conf.dest_dir_arg);
+out:
+       free(config_file);
+       if (ret >= 0)
+               return;
+       log_err_msg(EMERG, -ret);
+       exit(EXIT_FAILURE);
+}
+
+void handle_sighup(void)
+{
+       DSS_NOTICE_LOG("SIGHUP\n");
+       parse_config_file(1);
 }
 
 int rename_incomplete_snapshot(int64_t start)
@@ -704,7 +793,7 @@ void compute_next_snapshot_time(struct snapshot_list *sl)
        tv_add(&now, &tmp, &next_snapshot_time);
 }
 
-void handle_signal(struct snapshot_list *sl)
+void handle_signal(void)
 {
        int sig, ret = next_signal();
 
@@ -722,6 +811,7 @@ void handle_signal(struct snapshot_list *sl)
                exit(EXIT_FAILURE);
        case SIGHUP:
                handle_sighup();
+               ret = 1;
                break;
        case SIGCHLD:
                ret = reap_child(&pid, &status);
@@ -732,9 +822,6 @@ void handle_signal(struct snapshot_list *sl)
                        ret = handle_rsync_exit(status);
                else
                        ret = handle_rm_exit(status);
-               free_snapshot_list(sl);
-               get_snapshot_list(sl);
-               compute_next_snapshot_time(sl);
        }
 out:
        if (ret < 0)
@@ -820,14 +907,15 @@ int select_loop(void)
        struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
        struct snapshot_list sl = {.num_snapshots = 0};
 
-       get_snapshot_list(&sl);
-       compute_next_snapshot_time(&sl);
        for (;;) {
                struct timeval now, *tvp = &tv;
                fd_set rfds;
                int low_disk_space;
                char **rsync_argv;
 
+               free_snapshot_list(&sl);
+               get_snapshot_list(&sl);
+               compute_next_snapshot_time(&sl);
                FD_ZERO(&rfds);
                FD_SET(signal_pipe, &rfds);
                if (rsync_pid)
@@ -837,8 +925,10 @@ int select_loop(void)
                ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
                if (ret < 0)
                        return ret;
-               if (FD_ISSET(signal_pipe, &rfds))
-                       handle_signal(&sl);
+               if (FD_ISSET(signal_pipe, &rfds)) {
+                       handle_signal();
+                       continue;
+               }
                if (rm_pid)
                        continue;
                ret = disk_space_low();
@@ -978,61 +1068,6 @@ __noreturn void clean_exit(int status)
        free(dss_error_txt);
        exit(status);
 }
-
-int read_config_file(void)
-{
-       int ret;
-       char *config_file;
-       struct stat statbuf;
-
-       if (conf.config_file_given)
-               config_file = dss_strdup(conf.config_file_arg);
-       else {
-               char *home = get_homedir();
-               config_file = make_message("%s/.dssrc", home);
-               free(home);
-       }
-       ret = stat(config_file, &statbuf);
-       if (ret && conf.config_file_given) {
-               ret = -ERRNO_TO_DSS_ERROR(errno);
-               make_err_msg("failed to stat config file %s", config_file);
-               goto out;
-       }
-       if (!ret) {
-               struct cmdline_parser_params params = {
-                       .override = 0,
-                       .initialize = 0,
-                       .check_required = 0,
-                       .check_ambiguity = 0
-               };
-               cmdline_parser_config_file(config_file, &conf, &params);
-       }
-       if (!conf.source_dir_given || !conf.dest_dir_given) {
-               ret = -E_SYNTAX;
-               make_err_msg("you need to specify both source_dir and dest_dir");
-               goto out;
-       }
-       ret = 1;
-out:
-       free(config_file);
-       return ret;
-}
-
-int check_config(void)
-{
-       if (conf.unit_interval_arg <= 0) {
-               make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
-               return -E_INVALID_NUMBER;
-       }
-       DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
-       if (conf.num_intervals_arg <= 0) {
-               make_err_msg("bad number of intervals  %i", conf.num_intervals_arg);
-               return -E_INVALID_NUMBER;
-       }
-       DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
-       return 1;
-}
-
 static void setup_signal_handling(void)
 {
        int ret;
@@ -1059,24 +1094,11 @@ int main(int argc, char **argv)
        int ret;
 
        cmdline_parser(argc, argv, &conf); /* aborts on errors */
-       ret = read_config_file();
-       if (ret < 0)
-               goto out;
-       ret = check_config();
-       if (ret < 0)
-               goto out;
-       if (conf.logfile_given) {
-               logfile = open_log(conf.logfile_arg);
-               log_welcome(conf.loglevel_arg);
-       }
-       ret = dss_chdir(conf.dest_dir_arg);
-       if (ret < 0)
-               goto out;
+       parse_config_file(0);
        if (conf.daemon_given)
                daemon_init();
        setup_signal_handling();
        ret = call_command_handler();
-out:
        if (ret < 0)
                log_err_msg(EMERG, -ret);
        clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);

diff --git a/dss.ggo b/dss.ggo
index a0a3503c6862c56eaeb15a75d7d55598eca3eac5..57e931323ad026336d5ba77f12d93d155f85e7dd 100644 (file)
--- a/dss.ggo
+++ b/dss.ggo
@@ -21,6 +21,17 @@ details="
        configuration file. As usual, if an option is given both at
        the command line and in the configuration file, the command
        line option takes precedence.
+
+       However, there is an important exception to this rule:
+       If the --run option was given (see below) then dss honors
+       SIGHUP and re-reads its configuration file whenever it
+       receives this signal. In this case the options in the config
+       file override any options that were previously given at the
+       command line. This allows to change the configuration of a
+       running dss process on the fly by sending SIGHUP.
+
+       Note that it is not possible to change whether dss runs as
+       background daemon by sending SIGHUP.
 "
 
 option "daemon" d