[PATCH 8/8] btrfs-progs: add quota info to btrfs sub show

[jeffm@suse.com]

From: Jeff Mahoney <jeffm@suse.com>

This patch reports on the first-level qgroup, if any, associated with
a particular subvolume.  It displays the usage and limit, subject
to the usual unit parameters.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
---
 cmds-subvolume.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 8a473f7a..29d0e0e5 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -972,6 +972,7 @@ static const char * const cmd_subvol_show_usage[] = {
 	"Show more information about the subvolume",
 	"-r|--rootid   rootid of the subvolume",
 	"-u|--uuid     uuid of the subvolume",
+	HELPINFO_UNITS_SHORT_LONG,
 	"",
 	"If no option is specified, <subvol-path> will be shown, otherwise",
 	"the rootid or uuid are resolved relative to the <mnt> path.",
@@ -993,6 +994,13 @@ static int cmd_subvol_show(int argc, char **argv)
 	int by_uuid = 0;
 	u64 rootid_arg;
 	u8 uuid_arg[BTRFS_UUID_SIZE];
+	struct btrfs_qgroup_stats stats;
+	unsigned int unit_mode;
+	const char *referenced_size;
+	const char *referenced_limit_size = "-";
+	unsigned field_width = 0;
+
+	unit_mode = get_unit_mode_from_arg(&argc, argv, 1);
 
 	while (1) {
 		int c;
@@ -1112,6 +1120,44 @@ static int cmd_subvol_show(int argc, char **argv)
 	btrfs_list_subvols_print(fd, filter_set, NULL, BTRFS_LIST_LAYOUT_RAW,
 			1, raw_prefix);
 
+	ret = btrfs_qgroup_query(fd, get_ri.root_id, &stats);
+	if (ret < 0) {
+		if (ret == -ENODATA)
+			printf("Quotas must be enabled for per-subvolume usage\n");
+		else if (ret != -ENOTTY)
+			fprintf(stderr,
+				"\nERROR: BTRFS_IOC_QUOTA_QUERY failed: %s\n",
+				strerror(errno));
+		goto out;
+	}
+
+	printf("\tQuota Usage:\t\t");
+	fflush(stdout);
+
+	referenced_size = pretty_size_mode(stats.info.referenced, unit_mode);
+	if (stats.limit.max_referenced)
+	       referenced_limit_size = pretty_size_mode(
+						stats.limit.max_referenced,
+						unit_mode);
+	field_width = max(strlen(referenced_size),
+			  strlen(referenced_limit_size));
+
+	printf("%-*s referenced, %s exclusive\n ", field_width,
+	       referenced_size,
+	       pretty_size_mode(stats.info.exclusive, unit_mode));
+
+	printf("\tQuota Limits:\t\t");
+	if (stats.limit.max_referenced || stats.limit.max_exclusive) {
+		const char *excl = "-";
+
+		if (stats.limit.max_exclusive)
+		       excl = pretty_size_mode(stats.limit.max_exclusive,
+					       unit_mode);
+		printf("%-*s referenced, %s exclusive\n", field_width,
+		       referenced_limit_size, excl);
+	} else
+		printf("None\n");
+
 out:
 	/* clean up */
 	free(get_ri.path);
-- 
2.15.1