Merge pull request containerd#16 from stevvooe/handle-compile-errors

btrfs: remove C constant redefinitions

btrfs.go

@@ -7,10 +7,6 @@ import "sort"
 #include <btrfs/ioctl.h>
 #include "btrfs.h"
 
-// Required because Go has struct casting rules for negative numbers
-const __u64 u64_BTRFS_LAST_FREE_OBJECTID = (__u64)BTRFS_LAST_FREE_OBJECTID;
-const __u64 negative_one = (__u64)-1;
-
 static char* get_name_btrfs_ioctl_vol_args_v2(struct btrfs_ioctl_vol_args_v2* btrfs_struct) {
 	return btrfs_struct->name;
 }
@@ -100,9 +96,9 @@ func subvolMap(path string) (map[uint64]*Info, error) {
 	args.key.min_type = C.BTRFS_ROOT_ITEM_KEY
 	args.key.max_type = C.BTRFS_ROOT_BACKREF_KEY
 	args.key.min_objectid = C.BTRFS_FS_TREE_OBJECTID
-	args.key.max_objectid = C.u64_BTRFS_LAST_FREE_OBJECTID
-	args.key.max_offset = C.negative_one
-	args.key.max_transid = C.negative_one
+	args.key.max_objectid = C.BTRFS_LAST_FREE_OBJECTID
+	args.key.max_offset = ^C.__u64(0)
+	args.key.max_transid = ^C.__u64(0)
 
 	subvolsByID := make(map[uint64]*Info)