Btrfs: fix a regression in balance usage filter
Commit 3fed40cc ("Btrfs: cleanup duplicated division functions"), which
was merged into 3.8-rc1, has introduced a regression by removing logic
that was guarding us against bad user input. Bring it back.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9c84dbe..4696098 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2614,7 +2614,14 @@
cache = btrfs_lookup_block_group(fs_info, chunk_offset);
chunk_used = btrfs_block_group_used(&cache->item);
- user_thresh = div_factor_fine(cache->key.offset, bargs->usage);
+ if (bargs->usage == 0)
+ user_thresh = 0;
+ else if (bargs->usage > 100)
+ user_thresh = cache->key.offset;
+ else
+ user_thresh = div_factor_fine(cache->key.offset,
+ bargs->usage);
+
if (chunk_used < user_thresh)
ret = 0;