X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=dss.c;h=1354aa757128d1ec6069290f7c8303991e6eeb5c;hb=refs%2Fheads%2Fpu;hp=f61f33597d7863e236a804d6c0541934e6ced8d5;hpb=0c8b2267407ef681e2aba63b561a3c6b56a0fb7c;p=dss.git

diff --git a/dss.c b/dss.c
index f61f335..477df6f 100644
--- a/dss.c
+++ b/dss.c
@@ -65,6 +65,10 @@ static const struct lls_command *subcmd;
 static bool daemonized;
 /** Non-NULL if we log to a file. */
 static FILE *logfile;
+/* Realpath of the config file. */
+static char *config_file;
+/* derived from config file path */
+uint32_t ipc_key;
 /** The read end of the signal pipe */
 static int signal_pipe;
 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
@@ -271,27 +275,39 @@ static __printf_1_2 void dss_msg(const char* fmt,...)
 	va_end(argp);
 }
 
-static char *get_config_file_name(void)
+static void set_config_file_name(void)
 {
-	char *home, *config_file;
 
-	if (OPT_GIVEN(DSS, CONFIG_FILE))
-		return dss_strdup(OPT_STRING_VAL(DSS, CONFIG_FILE));
-	home = get_homedir();
-	config_file = make_message("%s/.dssrc", home);
-	free(home);
-	return config_file;
+	if (OPT_GIVEN(DSS, CONFIG_FILE)) {
+		const char *arg = OPT_STRING_VAL(DSS, CONFIG_FILE);
+		config_file = realpath(arg, NULL);
+		if (!config_file) {
+			DSS_EMERG_LOG(("could not resolve path %s: %s\n", arg,
+				strerror(errno)));
+			exit(EXIT_FAILURE);
+		}
+	} else {
+		char *home = get_homedir();
+		char *arg = make_message("%s/.dssrc", home);
+		free(home);
+		config_file = realpath(arg, NULL);
+		if (config_file)
+			free(arg);
+		else /* not fatal */
+			config_file = arg;
+	}
+	DSS_DEBUG_LOG(("config file: %s\n", config_file));
+	ipc_key = super_fast_hash((uint8_t *)config_file,
+		strlen(config_file), 0) >> 1;
 }
 
 static int send_signal(int sig, bool wait)
 {
 	pid_t pid;
-	char *config_file = get_config_file_name();
-	int ret = get_dss_pid(config_file, &pid);
+	int ret = get_dss_pid(ipc_key, &pid);
 	unsigned ms = 32;
 	struct timespec ts;
 
-	free(config_file);
 	if (ret < 0)
 		return ret;
 	if (OPT_GIVEN(DSS, DRY_RUN)) {
@@ -1122,7 +1138,6 @@ static int change_to_dest_dir(void)
 
 static int check_config(void)
 {
-	int ret;
 	uint32_t unit_interval = OPT_UINT32_VAL(DSS, UNIT_INTERVAL);
 	uint32_t num_intervals = OPT_UINT32_VAL(DSS, NUM_INTERVALS);
 
@@ -1147,9 +1162,6 @@ static int check_config(void)
 			DSS_ERROR_LOG(("--dest-dir required\n"));
 			return -E_SYNTAX;
 		}
-		ret = change_to_dest_dir();
-		if (ret < 0)
-			return ret;
 	}
 	DSS_DEBUG_LOG(("number of intervals: %i\n", num_intervals));
 	return 1;
@@ -1170,7 +1182,6 @@ static int lopsub_error(int lopsub_ret, char **errctx)
 static int parse_config_file(bool sighup, const struct lls_command *cmd)
 {
 	int ret, fd = -1;
-	char *config_file = get_config_file_name();
 	struct stat statbuf;
 	void *map;
 	size_t sz;
@@ -1262,9 +1273,6 @@ close_fd:
 	if (fd >= 0)
 		close(fd);
 out:
-	free(config_file);
-	if (ret < 0)
-		DSS_EMERG_LOG(("%s\n", dss_strerror(-ret)));
 	return ret;
 }
 
@@ -1595,10 +1603,8 @@ static void exit_hook(int exit_code)
 
 static void lock_dss_or_die(void)
 {
-	char *config_file = get_config_file_name();
-	int ret = lock_dss(config_file);
+	int ret = lock_dss(ipc_key);
 
-	free(config_file);
 	if (ret < 0) {
 		DSS_EMERG_LOG(("failed to lock: %s\n", dss_strerror(-ret)));
 		exit(EXIT_FAILURE);
@@ -1608,26 +1614,34 @@ static void lock_dss_or_die(void)
 static int com_run(void)
 {
 	int ret, fd = -1;
-	char *config_file;
 	pid_t pid;
 
 	if (OPT_GIVEN(DSS, DRY_RUN)) {
 		DSS_ERROR_LOG(("dry run not supported by this command\n"));
 		return -E_SYNTAX;
 	}
-	config_file = get_config_file_name();
-	ret = get_dss_pid(config_file, &pid);
-	free(config_file);
+	ret = get_dss_pid(ipc_key, &pid);
 	if (ret >= 0) {
 		DSS_ERROR_LOG(("pid %d\n", (int)pid));
 		return -E_ALREADY_RUNNING;
 	}
+	/*
+	 * Order is important here: Since daemon_init() forks, it would drop
+	 * the lock if it had been acquired already. Changing the cwd before
+	 * grabbing the lock causes stat(2) to fail in case a relative config
+	 * file path was given, which results in a different key ID for
+	 * locking. Therefore we must first daemonize, then lock, then change
+	 * the cwd.
+	 */
 	if (OPT_GIVEN(RUN, DAEMON)) {
 		fd = daemon_init();
 		daemonized = true;
 		logfile = open_log(OPT_STRING_VAL(RUN, LOGFILE));
 	}
 	lock_dss_or_die();
+	ret = change_to_dest_dir();
+	if (ret < 0)
+		return ret;
 	dump_dss_config("startup");
 	ret = install_sighandler(SIGHUP);
 	if (ret < 0)
@@ -1663,6 +1677,9 @@ static int com_prune(void)
 	bool try_hard;
 
 	lock_dss_or_die();
+	ret = change_to_dest_dir();
+	if (ret < 0)
+		return ret;
 	switch (OPT_UINT32_VAL(PRUNE, DISK_SPACE)) {
 	case FDS_LOW: try_hard = true; break;
 	case FDS_HIGH: try_hard = false; break;
@@ -1719,6 +1736,9 @@ static int com_create(void)
 	char **rsync_argv;
 
 	lock_dss_or_die();
+	ret = change_to_dest_dir();
+	if (ret < 0)
+		return ret;
 	if (OPT_GIVEN(DSS, DRY_RUN)) {
 		int i;
 		char *msg = NULL;
@@ -1764,11 +1784,14 @@ EXPORT_CMD_HANDLER(create);
 
 static int com_ls(void)
 {
-	int i;
+	int i, ret;
 	struct snapshot_list sl;
 	struct snapshot *s;
 	int64_t now = get_current_time();
 
+	ret = change_to_dest_dir();
+	if (ret < 0)
+		return ret;
 	dss_get_snapshot_list(&sl);
 	FOR_EACH_SNAPSHOT(s, i, &sl) {
 		int64_t d;
@@ -1806,19 +1829,23 @@ static int setup_signal_handling(void)
 	return install_sighandler(SIGCHLD);
 }
 
+const char *dss_version(void);
 static void handle_version_and_help(void)
 {
 	char *txt;
 
+	if (OPT_GIVEN(DSS, VERSION)) {
+		printf("%s\n", dss_version());
+		exit(EXIT_SUCCESS);
+	}
 	if (OPT_GIVEN(DSS, DETAILED_HELP))
 		txt = lls_long_help(CMD_PTR(DSS));
 	else if (OPT_GIVEN(DSS, HELP))
 		txt = lls_short_help(CMD_PTR(DSS));
-	else if (OPT_GIVEN(DSS, VERSION))
-		txt = make_message("%s\n", VERSION_STRING);
 	else
 		return;
 	printf("%s", txt);
+	printf("\nRun dss help for help on subcommands.\n");
 	free(txt);
 	exit(EXIT_SUCCESS);
 }
@@ -1834,9 +1861,40 @@ static void show_subcommand_summary(void)
 		const char *purpose = lls_purpose(cmd);
 		printf("%-11s%s\n", name, purpose);
 	}
-	exit(EXIT_SUCCESS);
+	printf("\nRun dss help <subcmd> for help on <subcmd>.\n");
 }
 
+static int com_help(void)
+{
+	int ret;
+	char *errctx, *help;
+	const char *arg;
+	const struct lls_command *cmd;
+
+	ret = lls_check_arg_count(sublpr, 0, 1, &errctx);
+	if (ret < 0)
+		return lopsub_error(ret, &errctx);
+	if (lls_num_inputs(sublpr) == 0) {
+		show_subcommand_summary();
+		return 0;
+	}
+	arg = lls_input(0, sublpr);
+	ret = lls_lookup_subcmd(arg, dss_suite, &errctx);
+	if (ret < 0)
+		return lopsub_error(ret, &errctx);
+	cmd = lls_cmd(ret, dss_suite);
+	if (OPT_GIVEN(HELP, LONG))
+		help = lls_long_help(cmd);
+	else
+		help = lls_short_help(cmd);
+	printf("%s", help);
+	free(help);
+	if (!OPT_GIVEN(HELP, LONG))
+		printf("\nRun dss -- help -l %s for long help.\n", arg);
+	return 0;
+}
+EXPORT_CMD_HANDLER(help);
+
 int main(int argc, char **argv)
 {
 	int ret;
@@ -1850,13 +1908,17 @@ int main(int argc, char **argv)
 		goto out;
 	}
 	lpr = cmdline_lpr;
+	set_config_file_name();
 	ret = parse_config_file(false /* no SIGHUP */, CMD_PTR(DSS));
 	if (ret < 0)
 		goto out;
 	handle_version_and_help();
 	num_inputs = lls_num_inputs(lpr);
-	if (num_inputs == 0)
+	if (num_inputs == 0) {
 		show_subcommand_summary();
+		ret = 0;
+		goto out;
+	}
 	ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
 	if (ret < 0) {
 		ret = lopsub_error(ret, &errctx);
@@ -1895,5 +1957,6 @@ out:
 	lls_free_parse_result(sublpr, subcmd);
 	if (sublpr != cmdline_sublpr)
 		lls_free_parse_result(cmdline_sublpr, subcmd);
+	free(config_file);
 	exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
 }