There is a messy cast here: min_t(int, len, (int)sizeof(*item))); min_t() should normally cast to unsigned. It's not possible for "len" to be negative, but if it were then we definitely wouldn't want to pass negatives to read_extent_buffer(). Also there is an extra cast. This patch shouldn't affect runtime, it's just a clean up. Suggested-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx> --- v2: modify commit message as Dan suggested --- fs/btrfs/root-tree.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 02d1a57af78b..893d12fbfda0 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -21,12 +21,12 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot, struct btrfs_root_item *item) { uuid_le uuid; - int len; + u32 len; int need_reset = 0; len = btrfs_item_size_nr(eb, slot); read_extent_buffer(eb, item, btrfs_item_ptr_offset(eb, slot), - min_t(int, len, (int)sizeof(*item))); + min_t(u32, len, sizeof(*item))); if (len < sizeof(*item)) need_reset = 1; if (!need_reset && btrfs_root_generation(item)