X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=dss.c;h=1354aa757128d1ec6069290f7c8303991e6eeb5c;hb=refs%2Fheads%2Fpu;hp=9390f48c9f8f16a810680b374050ae45ba6349b0;hpb=7a6ff706b99f35a3f4f1ee116f49827dbdf15c64;p=dss.git

diff --git a/dss.c b/dss.c
index 9390f48..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. */
@@ -81,7 +85,7 @@ static int64_t next_snapshot_time;
 static struct timeval next_removal_check;
 /** Creation time of the snapshot currently being created. */
 static int64_t current_snapshot_creation_time;
-/** The snapshot currently being removed. */
+/* Set by the pre-rm hook, cleared by handle_remove_exit(). */
 struct snapshot *snapshot_currently_being_removed;
 /** Needed by the post-create hook. */
 static char *path_to_last_complete_snapshot;
@@ -158,7 +162,7 @@ static void dump_dss_config(const char *msg)
 	fprintf(log, "\n*** internal state ***\n\n");
 	fprintf(log,
 		"pid: %d\n"
-		"logile: %s\n"
+		"logfile: %s\n"
 		"snapshot_currently_being_removed: %s\n"
 		"path_to_last_complete_snapshot: %s\n"
 		"reference_snapshot: %s\n"
@@ -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)) {
@@ -574,9 +590,6 @@ static int is_reference_snapshot(struct snapshot *s)
 	return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
 }
 
-/*
- * return: 0: no redundant snapshots, 1: rm process started, negative: error
- */
 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 {
 	int i, interval;
@@ -654,6 +667,7 @@ static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 	int i, num_complete;
 	struct snapshot *s, *ref = NULL;
 
+	DSS_DEBUG_LOG(("picking snapshot with earliest creation time\n"));
 	num_complete = num_complete_snapshots(sl);
 	if (num_complete <= OPT_UINT32_VAL(DSS, MIN_COMPLETE))
 		return NULL;
@@ -664,7 +678,6 @@ static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 			ref = s;
 			continue;
 		}
-		DSS_INFO_LOG(("oldest removable snapshot: %s\n", s->name));
 		return s;
 	}
 	assert(ref);
@@ -672,6 +685,50 @@ static struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 	return ref;
 }
 
+/* returns NULL <==> *reason is set to NULL */
+static struct snapshot *find_removable_snapshot(struct snapshot_list *sl,
+		bool try_hard, char **reason)
+{
+	struct snapshot *victim;
+
+	/*
+	 * Don't remove anything if there is free space and we have fewer
+	 * snapshots than configured, plus one. This way there is always one
+	 * snapshot that can be recycled.
+	 */
+	if (!try_hard && sl->num_snapshots <=
+			1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
+		goto nope;
+	victim = find_orphaned_snapshot(sl);
+	if (victim) {
+		*reason = make_message("orphaned");
+		return victim;
+	}
+	victim = find_outdated_snapshot(sl);
+	if (victim) {
+		*reason = make_message("outdated");
+		return victim;
+	}
+	if (!OPT_GIVEN(DSS, KEEP_REDUNDANT)) {
+		victim = find_redundant_snapshot(sl);
+		if (victim) {
+			*reason = make_message("redundant");
+			return victim;
+		}
+	}
+	if (!try_hard)
+		goto nope;
+	DSS_WARNING_LOG(("nothing obvious to remove\n"));
+	victim = find_oldest_removable_snapshot(sl);
+	if (victim) {
+		*reason = make_message("oldest");
+		return victim;
+	}
+nope:
+	*reason = NULL;
+	return NULL;
+}
+
 static int rename_incomplete_snapshot(int64_t start)
 {
 	char *old_name;
@@ -704,7 +761,7 @@ static int try_to_free_disk_space(void)
 	struct snapshot_list sl;
 	struct snapshot *victim;
 	struct timeval now;
-	const char *why;
+	char *why;
 	int low_disk_space;
 
 	ret = disk_space_low(NULL);
@@ -715,55 +772,25 @@ static int try_to_free_disk_space(void)
 	if (tv_diff(&next_removal_check, &now, NULL) > 0)
 		return 0;
 	if (!low_disk_space) {
-		if (OPT_GIVEN(DSS, KEEP_REDUNDANT))
-			return 0;
 		if (snapshot_creation_status != HS_READY)
 			return 0;
 		if (next_snapshot_is_due())
 			return 0;
 	}
-	/*
-	 * Idle and --keep_redundant not given, or low disk space. Look at
-	 * existing snapshots.
-	 */
+	/* Idle or low disk space, look at existing snapshots. */
 	dss_get_snapshot_list(&sl);
-	ret = 0;
-	/*
-	 * Don't remove anything if there is free space and we have fewer
-	 * snapshots than configured, plus one. This way there is always one
-	 * snapshot that can be recycled.
-	 */
-	if (!low_disk_space && sl.num_snapshots <=
-			1 << OPT_UINT32_VAL(DSS, NUM_INTERVALS))
-		goto out;
-	why = "outdated";
-	victim = find_outdated_snapshot(&sl);
-	if (victim)
-		goto remove;
-	why = "redundant";
-	victim = find_redundant_snapshot(&sl);
-	if (victim)
-		goto remove;
-	why = "orphaned";
-	victim = find_orphaned_snapshot(&sl);
+	victim = find_removable_snapshot(&sl, low_disk_space, &why);
+	if (victim) {
+		pre_remove_hook(victim, why);
+		free(why);
+	}
+	free_snapshot_list(&sl);
 	if (victim)
-		goto remove;
-	/* try harder only if disk space is low */
+		return 1;
 	if (!low_disk_space)
-		goto out;
-	DSS_WARNING_LOG(("disk space low and nothing obvious to remove\n"));
-	why = "oldest";
-	victim = find_oldest_removable_snapshot(&sl);
-	if (victim)
-		goto remove;
+		return 0;
 	DSS_CRIT_LOG(("uhuhu: disk space low and nothing to remove\n"));
-	ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
-	goto out;
-remove:
-	pre_remove_hook(victim, why);
-out:
-	free_snapshot_list(&sl);
-	return ret;
+	return -ERRNO_TO_DSS_ERROR(ENOSPC);
 }
 
 static void post_create_hook(void)
@@ -1111,7 +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);
 
@@ -1136,9 +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;
@@ -1159,7 +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;
@@ -1251,9 +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;
 }
 
@@ -1301,9 +1320,7 @@ static int handle_signal(void)
 	switch (sig) {
 	case SIGINT:
 	case SIGTERM:
-		kill_children();
-		ret = -E_SIGNAL;
-		break;
+		return -E_SIGNAL;
 	case SIGHUP:
 		ret = handle_sighup();
 		break;
@@ -1388,7 +1405,7 @@ out:
 static void create_rsync_argv(char ***argv, int64_t *num)
 {
 	char *logname;
-	int i = 0, j, N = OPT_GIVEN(DSS, RSYNC_OPTION);
+	int i = 0, j, N;
 	struct snapshot_list sl;
 	static bool seeded;
 
@@ -1397,7 +1414,13 @@ static void create_rsync_argv(char ***argv, int64_t *num)
 	name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
 	free_snapshot_list(&sl);
 
-	*argv = dss_malloc((15 + N) * sizeof(char *));
+	/*
+	 * We specify up to 6 arguments, one argument per given rsync option
+	 * and one argument per given source dir. We also need space for the
+	 * terminating NULL pointer.
+	 */
+	N = OPT_GIVEN(DSS, RSYNC_OPTION) + OPT_GIVEN(DSS, SOURCE_DIR);
+	*argv = dss_malloc((7 + N) * sizeof(char *));
 	(*argv)[i++] = dss_strdup("rsync");
 	(*argv)[i++] = dss_strdup("-a");
 	(*argv)[i++] = dss_strdup("--delete");
@@ -1409,7 +1432,7 @@ static void create_rsync_argv(char ***argv, int64_t *num)
 		DSS_NOTICE_LOG(("adding --checksum to rsync options\n"));
 		(*argv)[i++] = dss_strdup("--checksum");
 	}
-	for (j = 0; j < N; j++)
+	for (j = 0; j < OPT_GIVEN(DSS, RSYNC_OPTION); j++)
 		(*argv)[i++] = dss_strdup(lls_string_val(j,
 			OPT_RESULT(DSS, RSYNC_OPTION)));
 	if (name_of_reference_snapshot) {
@@ -1419,14 +1442,34 @@ static void create_rsync_argv(char ***argv, int64_t *num)
 	} else
 		DSS_INFO_LOG(("no suitable reference snapshot found\n"));
 	logname = dss_logname();
-	if (use_rsync_locally(logname))
-		(*argv)[i++] = dss_strdup(OPT_STRING_VAL(DSS, SOURCE_DIR));
-	else
-		(*argv)[i++] = make_message("%s@%s:%s/",
-			OPT_GIVEN(DSS, REMOTE_USER)?
-				OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
-			OPT_STRING_VAL(DSS, REMOTE_HOST),
-			OPT_STRING_VAL(DSS, SOURCE_DIR));
+	if (use_rsync_locally(logname)) {
+		for (j = 0; j < OPT_GIVEN(DSS, SOURCE_DIR); j++)
+			(*argv)[i++] = dss_strdup(lls_string_val(j,
+				OPT_RESULT(DSS, SOURCE_DIR)));
+	} else {
+		/*
+		 * dss-1.0 and earlier did not support multiple source
+		 * directories.  These versions appended a slash to the end of
+		 * the source directory to make sure that only the contents of
+		 * the single source directory, but not the directory itself,
+		 * are copied to the destination. For multiple source
+		 * directories, however, this is not a good idea because the
+		 * source directories may well contain identical file names,
+		 * which would then be copied to the same location on the
+		 * destination, overwriting each other. Moreover, we want the
+		 * directory on the destination match the source. To preserve
+		 * the old behaviour, we thus have to special-case N=1.
+		 */
+		for (j = 0; j < OPT_GIVEN(DSS, SOURCE_DIR); j++) {
+			(*argv)[i++] = make_message("%s@%s:%s%s",
+				OPT_GIVEN(DSS, REMOTE_USER)?
+					OPT_STRING_VAL(DSS, REMOTE_USER) : logname,
+				OPT_STRING_VAL(DSS, REMOTE_HOST),
+				lls_string_val(j, OPT_RESULT(DSS, SOURCE_DIR)),
+				OPT_GIVEN(DSS, SOURCE_DIR) == 1? "/" : ""
+			);
+		}
+	}
 	free(logname);
 	*num = get_current_time();
 	(*argv)[i++] = incomplete_name(*num);
@@ -1546,7 +1589,7 @@ static void exit_hook(int exit_code)
 {
 	pid_t pid;
 	char **argv, *tmp = dss_strdup(OPT_STRING_VAL(DSS, EXIT_HOOK));
-	unsigned n = split_args(tmp, &argv, " \t");
+	unsigned n = split_args(tmp, &argv);
 
 	n++;
 	argv = dss_realloc(argv, (n + 1) * sizeof(char *));
@@ -1560,10 +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);
@@ -1573,26 +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)
@@ -1624,55 +1673,58 @@ static int com_prune(void)
 	struct snapshot_list sl;
 	struct snapshot *victim;
 	struct disk_space ds;
-	const char *why;
+	char *why;
+	bool try_hard;
 
 	lock_dss_or_die();
-	ret = get_disk_space(".", &ds);
+	ret = change_to_dest_dir();
 	if (ret < 0)
 		return ret;
-	log_disk_space(&ds);
+	switch (OPT_UINT32_VAL(PRUNE, DISK_SPACE)) {
+	case FDS_LOW: try_hard = true; break;
+	case FDS_HIGH: try_hard = false; break;
+	default:
+		ret = get_disk_space(".", &ds);
+		if (ret < 0)
+			return ret;
+		log_disk_space(&ds);
+		try_hard = disk_space_low(&ds);
+	}
 	dss_get_snapshot_list(&sl);
-	why = "outdated";
-	victim = find_outdated_snapshot(&sl);
-	if (victim)
-		goto rm;
-	why = "redundant";
-	victim = find_redundant_snapshot(&sl);
-	if (victim)
-		goto rm;
-	ret = 0;
-	goto out;
-rm:
+	victim = find_removable_snapshot(&sl, try_hard, &why);
+	if (!victim) {
+		dss_msg("nothing to prune\n");
+		ret = 0;
+		goto free_sl;
+	}
 	if (OPT_GIVEN(DSS, DRY_RUN)) {
-		dss_msg("%s snapshot %s (interval = %i)\n",
+		dss_msg("picking %s snapshot %s (interval = %i)\n",
 			why, victim->name, victim->interval);
 		ret = 0;
-		goto out;
+		goto free_why;
 	}
 	pre_remove_hook(victim, why);
 	if (snapshot_removal_status == HS_PRE_RUNNING) {
 		ret = wait_for_remove_process();
 		if (ret < 0)
-			goto out;
+			goto free_why;
+		ret = -E_HOOK_FAILED;
 		if (snapshot_removal_status != HS_PRE_SUCCESS)
-			goto out;
+			goto free_why;
 	}
 	ret = exec_rm();
 	if (ret < 0)
-		goto out;
+		goto free_why;
 	ret = wait_for_remove_process();
 	if (ret < 0)
-		goto out;
-	if (snapshot_removal_status != HS_SUCCESS)
-		goto out;
+		goto free_why;
+	assert(snapshot_removal_status == HS_SUCCESS);
 	post_remove_hook();
-	if (snapshot_removal_status != HS_POST_RUNNING)
-		goto out;
+	assert(snapshot_removal_status == HS_POST_RUNNING);
 	ret = wait_for_remove_process();
-	if (ret < 0)
-		goto out;
-	ret = 1;
-out:
+free_why:
+	free(why);
+free_sl:
 	free_snapshot_list(&sl);
 	return ret;
 }
@@ -1684,6 +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;
@@ -1729,11 +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;
@@ -1771,19 +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 = dss_strdup(VERSION_STRING);
 	else
 		return;
 	printf("%s", txt);
+	printf("\nRun dss help for help on subcommands.\n");
 	free(txt);
 	exit(EXIT_SUCCESS);
 }
@@ -1799,8 +1861,39 @@ 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)
 {
@@ -1815,13 +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);
@@ -1860,5 +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);
 }