X-Git-Url: http://git.tuebingen.mpg.de/dss.git/log?a=blobdiff_plain;f=dss.c;h=f61f33597d7863e236a804d6c0541934e6ced8d5;hb=766ebea19c1618ddab85a4fc6af2a5bf53a9ec38;hp=bcaeff2dbba49cf1c1733530818f82871f16bb7b;hpb=c806f5edbbd5383c807b18ad5157b189c90fd6c7;p=dss.git

diff --git a/dss.c b/dss.c
index bcaeff2..f61f335 100644
--- a/dss.c
+++ b/dss.c
@@ -81,7 +81,7 @@ 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 +158,7 @@ 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"
@@ -574,9 +574,6 @@ 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 +651,7 @@ 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 +662,6 @@ 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 +669,50 @@ 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 +745,7 @@ 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 +756,25 @@ 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)
@@ -1386,7 +1397,7 @@ 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;
 
@@ -1395,7 +1406,13 @@ 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");
@@ -1407,7 +1424,7 @@ 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) {
@@ -1417,14 +1434,34 @@ 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);
@@ -1544,7 +1581,7 @@ 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 *));
@@ -1622,55 +1659,55 @@ 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);
-	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;
 }