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);
                free(s);
        }
        free(sl->interval_count);

+       sl->interval_count = NULL;

        free(sl->snapshots);
        free(sl->snapshots);

+       sl->snapshots = NULL;
+       sl->num_snapshots = 0;

 }
 
 void stop_rsync_process(void)
 }
 
 void stop_rsync_process(void)


@@ -546,9 +549,95 @@ void kill_process(pid_t pid)
        kill(pid, SIGTERM);
 }
 
        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)
 }
 
 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);
 }
 
        tv_add(&now, &tmp, &next_snapshot_time);
 }
 

-void handle_signal(struct snapshot_list *sl)
+void handle_signal(void)

 {
        int sig, ret = next_signal();
 
 {
        int sig, ret = next_signal();
 


@@ -722,6 +811,7 @@ void handle_signal(struct snapshot_list *sl)
                exit(EXIT_FAILURE);
        case SIGHUP:
                handle_sighup();
                exit(EXIT_FAILURE);
        case SIGHUP:
                handle_sighup();

+               ret = 1;

                break;
        case SIGCHLD:
                ret = reap_child(&pid, &status);
                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);
                        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)
        }
 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};
 
        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;
 
        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)
                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;
                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();
                if (rm_pid)
                        continue;
                ret = disk_space_low();


@@ -978,61 +1068,6 @@ __noreturn void clean_exit(int status)
        free(dss_error_txt);
        exit(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;
 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 */
        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();
        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);
        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.
        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
 "
 
 option "daemon" d