Don't account the free space in a data relocation space-info sub-group as
usable free space in statfs.

This is misleading as no user allocations can be made in this space-info
sub-group. It is only a target for relocation.

Fixes: f92ee31e031c ("btrfs: introduce btrfs_space_info sub-group")
Reviewed-by: Boris Burkov <redacted>
Signed-off-by: Johannes Thumshirn <redacted>
---
 fs/btrfs/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index fb15decb0861..a0dbc0d2213f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c

@@ -1739,7 +1739,8 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 	int mixed = 0;
 
 	list_for_each_entry(found, &fs_info->space_info, list) {
-		if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
+		if (found->flags & BTRFS_BLOCK_GROUP_DATA &&
+		    found->subgroup_id != BTRFS_SUB_GROUP_DATA_RELOC) {
 			int i;
 
 			total_free_data += found->disk_total - found->disk_used;

-- 
2.54.0