X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.c;h=793e9194b1c695fb89d50d3fae5f63703dceeccd;hp=db065c689b95dc0274231c9923cb9be6dd852839;hb=55c90e8e1d56bc2aec456067cdd1789d09f97d74;hpb=00c1e3fbafc6310a32bf39bbd8c36a7acee275f9

diff --git a/dss.c b/dss.c
index db065c6..793e919 100644
--- a/dss.c
+++ b/dss.c
@@ -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;
@@ -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);
@@ -906,18 +951,11 @@ 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);
@@ -964,7 +1002,7 @@ 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);
 	}
@@ -1043,22 +1081,48 @@ 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 *s;
+	struct snapshot *s = NULL;
 	char *new_name = incomplete_name(creation_time);
 	int ret;
+	const char *why;
 
 	ret = 0;
 	if (conf.no_resume_given)
 		goto out;
 	dss_get_snapshot_list(&sl);
+	/*
+	 * Snapshot recycling: We first look at the newest snapshot. If this
+	 * snapshot happens to be incomplete, the last rsync process was
+	 * aborted and we reuse this one. Otherwise we look at snapshots which
+	 * could be removed (outdated and redundant snapshots) as candidates
+	 * for recycling. If no outdated/redundant snapshot exists, we check if
+	 * there is an orphaned snapshot, which likely is useless anyway.
+	 *
+	 * Only if no existing snapshot is suitable for recycling, we bite the
+	 * bullet and create a new one.
+	 */
 	s = get_newest_snapshot(&sl);
-	if (!s)
+	if (!s) /* no snapshots at all */
 		goto out;
-	if ((s->flags & SS_COMPLETE) != 0) /* complete */
+	/* re-use last snapshot if it is incomplete */
+	why = "aborted";
+	if ((s->flags & SS_COMPLETE) == 0)
 		goto out;
-	DSS_INFO_LOG("resuming: reusing %s as destination dir\n", s->name);
-	ret = dss_rename(s->name, new_name);
+	why = "outdated";
+	s = find_outdated_snapshot(&sl);
+	if (s)
+		goto out;
+	why = "redundant";
+	s = find_redundant_snapshot(&sl);
+	if (s)
+		goto out;
+	why = "orphaned";
+	s = find_orphaned_snapshot(&sl);
 out:
+	if (s) {
+		DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
+		ret = dss_rename(s->name, new_name);
+	}
 	if (ret >= 0)
 		DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
 	free(new_name);
@@ -1228,10 +1292,23 @@ static void exit_hook(int exit_code)
 	dss_exec(&pid, conf.exit_hook_arg, argv, fds);
 }
 
+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;
@@ -1254,6 +1331,7 @@ 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;
@@ -1313,6 +1391,7 @@ 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;