Merge branch 't/cleanups'
[dss.git] / dss.c
diff --git a/dss.c b/dss.c
index 223f80e086e66b6ae3367e84292de91c62a9195a..745729fae629aa279a1747f5779faa92fe901866 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2008-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2008-2011 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -33,6 +33,7 @@
 #include "df.h"
 #include "time.h"
 #include "snap.h"
+#include "ipc.h"
 
 /** Command line and config file options. */
 static struct gengetopt_args_info conf;
@@ -64,7 +65,7 @@ enum hook_status snapshot_removal_status;
 
 
 DEFINE_DSS_ERRLIST;
-static const char const *hook_status_description[] = {HOOK_STATUS_ARRAY};
+static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
 
 /* may be called with ds == NULL. */
 static int disk_space_low(struct disk_space *ds)
@@ -170,7 +171,10 @@ static void dump_dss_config(const char *msg)
        COMMAND(ls) \
        COMMAND(create) \
        COMMAND(prune) \
-       COMMAND(run)
+       COMMAND(run) \
+       COMMAND(kill) \
+       COMMAND(reload) \
+
 #define COMMAND(x) static int com_ ##x(void);
 COMMANDS
 #undef COMMAND
@@ -226,6 +230,47 @@ static __printf_1_2 void dss_msg(const char* fmt,...)
        va_end(argp);
 }
 
+static char *get_config_file_name(void)
+{
+       char *home, *config_file;
+
+       if (conf.config_file_given)
+               return dss_strdup(conf.config_file_arg);
+       home = get_homedir();
+       config_file = make_message("%s/.dssrc", home);
+       free(home);
+       return config_file;
+}
+
+static int send_signal(int sig)
+{
+       pid_t pid;
+       char *config_file = get_config_file_name();
+       int ret = get_dss_pid(config_file, &pid);
+
+       free(config_file);
+       if (ret < 0)
+               return ret;
+       if (conf.dry_run_given) {
+               dss_msg("%d\n", (int)pid);
+               return 0;
+       }
+       ret = kill(pid, sig);
+       if (ret < 0)
+               return -ERRNO_TO_DSS_ERROR(errno);
+       return 1;
+}
+
+static int com_kill(void)
+{
+       return send_signal(SIGTERM);
+}
+
+static int com_reload(void)
+{
+       return send_signal(SIGHUP);
+}
+
 static void dss_get_snapshot_list(struct snapshot_list *sl)
 {
        get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
@@ -287,29 +332,22 @@ static int next_snapshot_is_due(void)
        return 0;
 }
 
-static int pre_create_hook(void)
+static void pre_create_hook(void)
 {
-       int ret, fds[3] = {0, 0, 0};
-
        assert(snapshot_creation_status == HS_READY);
        /* make sure that the next snapshot time will be recomputed */
        invalidate_next_snapshot_time();
        DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
-       ret = dss_exec_cmdline_pid(&create_pid,
-               conf.pre_create_hook_arg, fds);
-       if (ret < 0)
-               return ret;
+       dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
        snapshot_creation_status = HS_PRE_RUNNING;
-       return ret;
 }
 
-static int pre_remove_hook(struct snapshot *s, const char *why)
+static void pre_remove_hook(struct snapshot *s, const char *why)
 {
-       int ret, fds[3] = {0, 0, 0};
        char *cmd;
 
        if (!s)
-               return 0;
+               return;
        DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
        assert(snapshot_removal_status == HS_READY);
        assert(remove_pid == 0);
@@ -322,22 +360,23 @@ static int pre_remove_hook(struct snapshot *s, const char *why)
        cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
                conf.dest_dir_arg, s->name);
        DSS_DEBUG_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
+       dss_exec_cmdline_pid(&remove_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_removal_status = HS_PRE_RUNNING;
-       return ret;
 }
 
 static int exec_rm(void)
 {
        struct snapshot *s = snapshot_currently_being_removed;
-       int fds[3] = {0, 0, 0};
        char *new_name = being_deleted_name(s);
-       char *argv[] = {"rm", "-rf", new_name, NULL};
+       char *argv[4];
        int ret;
 
+       argv[0] = "rm";
+       argv[1] = "-rf";
+       argv[2] = new_name;
+       argv[3] = NULL;
+
        assert(snapshot_removal_status == HS_PRE_SUCCESS);
        assert(remove_pid == 0);
 
@@ -345,9 +384,7 @@ static int exec_rm(void)
        ret = dss_rename(s->name, new_name);
        if (ret < 0)
                goto out;
-       ret = dss_exec(&remove_pid, argv[0], argv, fds);
-       if (ret < 0)
-               goto out;
+       dss_exec(&remove_pid, argv[0], argv);
        snapshot_removal_status = HS_RUNNING;
 out:
        free(new_name);
@@ -418,8 +455,6 @@ static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 
                if (keep >= num)
                        missing += keep - num;
-//             DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
-//                     interval, keep, num, missing);
                if (keep + missing >= num)
                        continue;
                /* redundant snapshot in this interval, pick snapshot with lowest score */
@@ -430,7 +465,6 @@ static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
                                continue;
                        if (is_reference_snapshot(s))
                                continue;
-                       //DSS_DEBUG_LOG("checking %s\n", s->name);
                        if (s->interval > interval) {
                                prev = s;
                                continue;
@@ -446,7 +480,6 @@ static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
                        /* check if s is a better victim */
                        this_score = s->creation_time - prev->creation_time;
                        assert(this_score >= 0);
-                       //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
                        if (this_score < score) {
                                score = this_score;
                                victim = s;
@@ -563,31 +596,24 @@ static int try_to_free_disk_space(void)
        ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
        goto out;
 remove:
-       ret = pre_remove_hook(victim, why);
+       pre_remove_hook(victim, why);
 out:
        free_snapshot_list(&sl);
        return ret;
 }
 
-static int post_create_hook(void)
+static void post_create_hook(void)
 {
-       int ret, fds[3] = {0, 0, 0};
-       char *cmd;
-
-       cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
+       char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
                conf.dest_dir_arg, path_to_last_complete_snapshot);
        DSS_NOTICE_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
+       dss_exec_cmdline_pid(&create_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_creation_status = HS_POST_RUNNING;
-       return ret;
 }
 
-static int post_remove_hook(void)
+static void post_remove_hook(void)
 {
-       int ret, fds[3] = {0, 0, 0};
        char *cmd;
        struct snapshot *s = snapshot_currently_being_removed;
 
@@ -596,12 +622,9 @@ static int post_remove_hook(void)
        cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
                conf.dest_dir_arg, s->name);
        DSS_NOTICE_LOG("executing %s\n", cmd);
-       ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
+       dss_exec_cmdline_pid(&remove_pid, cmd);
        free(cmd);
-       if (ret < 0)
-               return ret;
        snapshot_removal_status = HS_POST_RUNNING;
-       return ret;
 }
 
 static void dss_kill(pid_t pid, int sig, const char *msg)
@@ -906,18 +929,11 @@ static int check_config(void)
 static int parse_config_file(int override)
 {
        int ret, config_file_exists;
-       char *config_file;
+       char *config_file = get_config_file_name();
        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);
@@ -931,13 +947,12 @@ static int parse_config_file(int override)
                goto out;
        }
        if (config_file_exists) {
-               struct cmdline_parser_params params = {
-                       .override = override,
-                       .initialize = 0,
-                       .check_required = 1,
-                       .check_ambiguity = 0,
-                       .print_errors = 1
-               };
+               struct cmdline_parser_params params;
+               params.override = override;
+               params.initialize = 0;
+               params.check_required = 1;
+               params.check_ambiguity = 0;
+               params.print_errors = 1;
                if (override) { /* invalidate all rsync options */
                        int i;
 
@@ -964,7 +979,7 @@ static int parse_config_file(int override)
                        conf.logfile_given = 1;
                }
        }
-       if (conf.logfile_given) {
+       if (conf.logfile_given && conf.run_given && conf.daemon_given) {
                logfile = open_log(conf.logfile_arg);
                log_welcome(conf.loglevel_arg);
        }
@@ -1042,12 +1057,14 @@ static int use_rsync_locally(char *logname)
 
 static int rename_resume_snap(int64_t creation_time)
 {
-       struct snapshot_list sl = {.num_snapshots = 0};
+       struct snapshot_list sl;
        struct snapshot *s = NULL;
        char *new_name = incomplete_name(creation_time);
        int ret;
        const char *why;
 
+       sl.num_snapshots = 0;
+
        ret = 0;
        if (conf.no_resume_given)
                goto out;
@@ -1143,14 +1160,12 @@ static void free_rsync_argv(char **argv)
 
 static int create_snapshot(char **argv)
 {
-       int ret, fds[3] = {0, 0, 0};
+       int ret;
 
        ret = rename_resume_snap(current_snapshot_creation_time);
        if (ret < 0)
                return ret;
-       ret = dss_exec(&create_pid, argv[0], argv, fds);
-       if (ret < 0)
-               return ret;
+       dss_exec(&create_pid, argv[0], argv);
        snapshot_creation_status = HS_RUNNING;
        return ret;
 }
@@ -1192,9 +1207,7 @@ static int select_loop(void)
                        continue;
                }
                if (snapshot_removal_status == HS_SUCCESS) {
-                       ret = post_remove_hook();
-                       if (ret < 0)
-                               goto out;
+                       post_remove_hook();
                        continue;
                }
                ret = try_to_free_disk_space();
@@ -1209,9 +1222,7 @@ static int select_loop(void)
                case HS_READY:
                        if (!next_snapshot_is_due())
                                continue;
-                       ret = pre_create_hook();
-                       if (ret < 0)
-                               goto out;
+                       pre_create_hook();
                        continue;
                case HS_PRE_RUNNING:
                case HS_RUNNING:
@@ -1234,9 +1245,7 @@ static int select_loop(void)
                                goto out;
                        continue;
                case HS_SUCCESS:
-                       ret = post_create_hook();
-                       if (ret < 0)
-                               goto out;
+                       post_create_hook();
                        continue;
                }
        }
@@ -1246,18 +1255,34 @@ out:
 
 static void exit_hook(int exit_code)
 {
-       int fds[3] = {0, 0, 0};
-       char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
+       char *argv[3];
        pid_t pid;
 
+       argv[0] = conf.exit_hook_arg;
+       argv[1] = dss_strerror(-exit_code);
+       argv[2] = NULL;
+
        DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
-       dss_exec(&pid, conf.exit_hook_arg, argv, fds);
+       dss_exec(&pid, conf.exit_hook_arg, argv);
+}
+
+static void lock_dss_or_die(void)
+{
+       char *config_file = get_config_file_name();
+       int ret = lock_dss(config_file);
+
+       free(config_file);
+       if (ret < 0) {
+               DSS_EMERG_LOG("failed to lock: %s\n", dss_strerror(-ret));
+               exit(EXIT_FAILURE);
+       }
 }
 
 static int com_run(void)
 {
        int ret;
 
+       lock_dss_or_die();
        if (conf.dry_run_given) {
                DSS_ERROR_LOG("dry_run not supported by this command\n");
                return -E_SYNTAX;
@@ -1280,6 +1305,7 @@ static int com_prune(void)
        struct disk_space ds;
        const char *why;
 
+       lock_dss_or_die();
        ret = get_disk_space(".", &ds);
        if (ret < 0)
                return ret;
@@ -1302,9 +1328,7 @@ rm:
                ret = 0;
                goto out;
        }
-       ret = pre_remove_hook(victim, why);
-       if (ret < 0)
-               goto out;
+       pre_remove_hook(victim, why);
        if (snapshot_removal_status == HS_PRE_RUNNING) {
                ret = wait_for_remove_process();
                if (ret < 0)
@@ -1320,9 +1344,7 @@ rm:
                goto out;
        if (snapshot_removal_status != HS_SUCCESS)
                goto out;
-       ret = post_remove_hook();
-       if (ret < 0)
-               goto out;
+       post_remove_hook();
        if (snapshot_removal_status != HS_POST_RUNNING)
                goto out;
        ret = wait_for_remove_process();
@@ -1339,6 +1361,7 @@ static int com_create(void)
        int ret, status;
        char **rsync_argv;
 
+       lock_dss_or_die();
        if (conf.dry_run_given) {
                int i;
                char *msg = NULL;
@@ -1354,9 +1377,7 @@ static int com_create(void)
                free(msg);
                return 1;
        }
-       ret = pre_create_hook();
-       if (ret < 0)
-               return ret;
+       pre_create_hook();
        if (create_pid) {
                ret = wait_for_process(create_pid, &status);
                if (ret < 0)
@@ -1424,13 +1445,13 @@ static int setup_signal_handling(void)
 int main(int argc, char **argv)
 {
        int ret;
-       struct cmdline_parser_params params = {
-               .override = 0,
-               .initialize = 1,
-               .check_required = 0,
-               .check_ambiguity = 0,
-               .print_errors = 1
-       };
+       struct cmdline_parser_params params;
+
+       params.override = 0;
+       params.initialize = 1;
+       params.check_required = 0;
+       params.check_ambiguity = 0;
+       params.print_errors = 1;
 
        cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
        ret = parse_config_file(0);
@@ -1441,13 +1462,12 @@ int main(int argc, char **argv)
                 * Parse the command line options again, but this time check
                 * that all required options are given.
                 */
-               params = (struct cmdline_parser_params) {
-                       .override = 1,
-                       .initialize = 1,
-                       .check_required = 1,
-                       .check_ambiguity = 1,
-                       .print_errors = 1
-               };
+               struct cmdline_parser_params params;
+               params.override = 1;
+               params.initialize = 1;
+               params.check_required = 1;
+               params.check_ambiguity = 1;
+               params.print_errors = 1;
                cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
        }
        if (conf.daemon_given)