bectl(8): Sort BEs lightly by active (now or later) BE, then others

While it could be preferred to do this at insert in libbe(3), there's no
convenient way to insert at the head of an nvlist. Instead, we'll make two
passes over- once to print anything active either now or at nextboot, and
another to print everything else.

This doesn't actually impact performance in a significant way here, so we'll
worry about further optimizations if the need actually arises.

1 files changed, 31 insertions, 5 deletions

diff --git a/sbin/bectl/bectl.c b/sbin/bectl/bectl.c
index 59174d8ad5fa..9764ea6e443c 100644
--- a/sbin/bectl/bectl.c
+++ b/sbin/bectl/bectl.c
@@ -59,7 +59,6 @@ struct printc {
 	int	current_indent;
 	int	mount_colsz;
 	int	space_colsz;
-	bool	final_be;
 	bool	hide_headers;
 	bool	show_all_datasets;
 	bool	show_snaps;
@@ -489,8 +488,6 @@ print_info(const char *name, nvlist_t *dsprops, struct printc *pc)
 			nvlist_free(originprops);
 		}
 		pc->current_indent = 0;
-		if (!pc->final_be)
-			printf("\n");
 		return;
 	}
 
@@ -600,9 +597,11 @@ bectl_cmd_list(int argc, char *argv[])
 	struct printc pc;
 	nvpair_t *cur;
 	nvlist_t *dsprops, *props;
-	int opt;
+	int opt, printed;
+	boolean_t active_now, active_reboot;
 
 	props = NULL;
+	printed = 0;
 	bzero(&pc, sizeof(pc));
 	while ((opt = getopt(argc, argv, "aDHs")) != -1) {
 		switch (opt) {
@@ -643,11 +642,38 @@ bectl_cmd_list(int argc, char *argv[])
 	}
 
 	print_headers(props, &pc);
+	/* Do a first pass to print active and next active first */
+	for (cur = nvlist_next_nvpair(props, NULL); cur != NULL;
+	    cur = nvlist_next_nvpair(props, cur)) {
+		nvpair_value_nvlist(cur, &dsprops);
+		active_now = active_reboot = false;
+
+		nvlist_lookup_boolean_value(dsprops, "active", &active_now);
+		nvlist_lookup_boolean_value(dsprops, "nextboot",
+		    &active_reboot);
+		if (!active_now && !active_reboot)
+			continue;
+		if (printed > 0 && (pc.show_all_datasets || pc.show_snaps))
+			printf("\n");
+		print_info(nvpair_name(cur), dsprops, &pc);
+		printed++;
+	}
+
+	/* Now pull everything else */
 	for (cur = nvlist_next_nvpair(props, NULL); cur != NULL;
 	    cur = nvlist_next_nvpair(props, cur)) {
 		nvpair_value_nvlist(cur, &dsprops);
-		pc.final_be = nvlist_next_nvpair(props, cur) == NULL;
+		active_now = active_reboot = false;
+
+		nvlist_lookup_boolean_value(dsprops, "active", &active_now);
+		nvlist_lookup_boolean_value(dsprops, "nextboot",
+		    &active_reboot);
+		if (active_now || active_reboot)
+			continue;
+		if (printed > 0 && (pc.show_all_datasets || pc.show_snaps))
+			printf("\n");
 		print_info(nvpair_name(cur), dsprops, &pc);
+		printed++;
 	}
 	be_prop_list_free(props);