X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.c;h=a233c11f7060c0321502c35e555df78ef0b3931b;hp=6101f17742c7ba8ef6e3a57a1878dfccb7227feb;hb=1e77c93a4da4dae8b75fcd305552e56ccae89b90;hpb=0ba29646cbd80a8bb7bdf827352bd1332217c398

diff --git a/dss.c b/dss.c
index 6101f17..a233c11 100644
--- a/dss.c
+++ b/dss.c
@@ -47,7 +47,7 @@ static int create_process_stopped;
 /** Process id of current pre-remove/rm/post-remove process. */
 static pid_t remove_pid;
 /** When the next snapshot is due. */
-static struct timeval next_snapshot_time;
+static int64_t next_snapshot_time;
 /** When to try to remove something. */
 static struct timeval next_removal_check;
 /** Creation time of the snapshot currently being created. */
@@ -151,21 +151,16 @@ static void dss_get_snapshot_list(struct snapshot_list *sl)
 	get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 }
 
-static int next_snapshot_is_due(void)
+static int64_t compute_next_snapshot_time(void)
 {
-	struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
-		tmp, diff;
-	int64_t x = 0;
+	int64_t x = 0, now = get_current_time(), unit_interval
+		= 24 * 3600 * conf.unit_interval_arg, ret;
 	unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
 		num_complete_snapshots = 0;
-	int i, ret;
+	int i;
 	struct snapshot *s = NULL;
 	struct snapshot_list sl;
 
-	gettimeofday(&now, NULL);
-	if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
-		return 0;
-	assert(snapshot_creation_status == HS_READY);
 	current_snapshot_creation_time = 0;
 	dss_get_snapshot_list(&sl);
 	FOR_EACH_SNAPSHOT(s, i, &sl) {
@@ -175,37 +170,52 @@ static int next_snapshot_is_due(void)
 		x += s->completion_time - s->creation_time;
 	}
 	assert(x >= 0);
-	if (num_complete_snapshots)
-		x /= num_complete_snapshots; /* avg time to create one snapshot */
-	x *= wanted; /* time to create all snapshots in interval 0 */
-	tmp.tv_sec = x;
-	tmp.tv_usec = 0;
-	ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
-	if (ret < 0 || !s) { /* unit_interval < tmp or no snapshot */
-		ret = 1;
-		goto out;
-	}
 
-	tv_divide(wanted, &diff, &tmp); /* sleep time between two snapshots */
-	diff.tv_sec = s->completion_time; /* completion time of the latest snapshot */
-	diff.tv_usec = 0;
-	tv_add(&diff, &tmp, &next_snapshot_time);
-	ret = (tv_diff(&now, &next_snapshot_time, &diff) < 0)? 0 : 1;
+	ret = now;
+	if (num_complete_snapshots == 0)
+		goto out;
+	x /= num_complete_snapshots; /* avg time to create one snapshot */
+	if (unit_interval < x * wanted) /* oops, no sleep at all */
+		goto out;
+	ret = s->completion_time + unit_interval / wanted - x;
 out:
 	free_snapshot_list(&sl);
-	if (ret == 0)
-		DSS_DEBUG_LOG("next snapshot due in %lu seconds\n",
-			tv2ms(&diff) / 1000);
-	else
-		DSS_DEBUG_LOG("next snapshot: now\n");
 	return ret;
 }
 
+static inline void invalidate_next_snapshot_time(void)
+{
+	next_snapshot_time = 0;
+}
+
+static inline int next_snapshot_time_is_valid(void)
+{
+	return next_snapshot_time != 0;
+}
+
+static int next_snapshot_is_due(void)
+{
+	int64_t now = get_current_time();
+
+	assert(snapshot_creation_status == HS_READY);
+	if (!next_snapshot_time_is_valid())
+		next_snapshot_time = compute_next_snapshot_time();
+	if (next_snapshot_time <= now) {
+		DSS_DEBUG_LOG("next snapshot: now\n");
+		return 1;
+	}
+	DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
+		next_snapshot_time - now);
+	return 0;
+}
+
 static int 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();
 	if (!conf.pre_create_hook_given) {
 		snapshot_creation_status = HS_PRE_SUCCESS;
 		return 0;
@@ -385,14 +395,14 @@ static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
 	int i;
 	struct snapshot *s;
 
-	DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
+	DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
 		conf.num_intervals_arg);
 	FOR_EACH_SNAPSHOT(s, i, sl) {
 		if (snapshot_is_being_created(s))
 			continue;
 		if (is_reference_snapshot(s))
 			continue;
-		if (s->interval <= conf.num_intervals_arg)
+		if (s->interval < conf.num_intervals_arg)
 			continue;
 		return s;
 	}
@@ -707,8 +717,7 @@ static int handle_rsync_exit(int status)
 		DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
 			(int)create_pid, es);
 		snapshot_creation_status = HS_NEEDS_RESTART;
-		gettimeofday(&next_snapshot_time, NULL);
-		next_snapshot_time.tv_sec += 60;
+		next_snapshot_time = get_current_time() + 60;
 		ret = 1;
 		goto out;
 	}
@@ -748,8 +757,7 @@ static int handle_pre_create_hook_exit(int status)
 			DSS_NOTICE_LOG("deferring snapshot creation...\n");
 			warn_count = 60; /* warn only once per hour */
 		}
-		gettimeofday(&next_snapshot_time, NULL);
-		next_snapshot_time.tv_sec += 60;
+		next_snapshot_time = get_current_time() + 60;
 		snapshot_creation_status = HS_READY;
 		ret = 0;
 		goto out;
@@ -810,9 +818,13 @@ static int check_config(void)
 	return 1;
 }
 
+/*
+ * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
+ * file was read successfully.
+ */
 static int parse_config_file(int override)
 {
-	int ret;
+	int ret, config_file_exists;
 	char *config_file;
 	struct stat statbuf;
 	char *old_logfile_arg = NULL;
@@ -831,13 +843,13 @@ static int parse_config_file(int override)
 		old_daemon_given = conf.daemon_given;
 	}
 
-	ret = stat(config_file, &statbuf);
-	if (ret && conf.config_file_given) {
+	config_file_exists = !stat(config_file, &statbuf);
+	if (!config_file_exists && conf.config_file_given) {
 		ret = -ERRNO_TO_DSS_ERROR(errno);
 		DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
 		goto out;
 	}
-	if (!ret) {
+	if (config_file_exists) {
 		struct cmdline_parser_params params = {
 			.override = override,
 			.initialize = 0,
@@ -877,6 +889,7 @@ static int parse_config_file(int override)
 	}
 	DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
 //	cmdline_parser_dump(logfile? logfile : stdout, &conf);
+	ret = config_file_exists;
 out:
 	free(config_file);
 	if (ret < 0)
@@ -898,6 +911,7 @@ static int handle_sighup(void)
 	ret = parse_config_file(1);
 	if (ret < 0)
 		return ret;
+	invalidate_next_snapshot_time();
 	return change_to_dest_dir();
 }
 
@@ -1285,6 +1299,20 @@ int main(int argc, char **argv)
 	ret = parse_config_file(0);
 	if (ret < 0)
 		goto out;
+	if (ret == 0) { /* no config file given */
+		/*
+		 * 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
+		};
+		cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
+	}
 	if (conf.daemon_given)
 		daemon_init();
 	ret = change_to_dest_dir();