btrfs-progs: qgroup: move btrfs_show_qgroups's error handler to __qgroup_search

We have to process the return value of BTRFS_IOC_TREE_SEARCH ioctl in
advance, so that we can distinguish between the two case where quota
is not enabled (ioctl return -ENOENT) and either parent qgroup or child
qgroup does not exist (update_qgroup_relation return -ENOENT). Besides
this, any error in this routine has been reported, so we don't need to
report again in cmd_qgroup_show.

Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/qgroup.c b/qgroup.c
index 156825fd..23463d8a 100644
--- a/qgroup.c
+++ b/qgroup.c
@@ -1065,8 +1065,18 @@ static int __qgroups_search(int fd, struct qgroup_lookup *qgroup_lookup)
 
 	while (1) {
 		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
-		if (ret < 0)
-			return -errno;
+		if (ret < 0) {
+			if (errno == ENOENT) {
+				error("can't list qgroups: quotas not enabled");
+				ret = -ENOTTY;
+			} else {
+				error("can't list qgroups: %s",
+				       strerror(errno));
+				ret = -errno;
+			}
+
+			break;
+		}
 
 		/* the ioctl returns the number of item it found in nr_items */
 		if (sk->nr_items == 0)