$ make btrfs-sb-mod
$ ./btrfs-sb-mod image field1 operation1 ...
Fields (only u64 supported for now):
* total_bytes
* root
* generation
* chunk_root
* chunk_root_generation
* cache_generation
* uuid_tree_generation
Operations:
* read value ?0
* set value =NUMBER
* add to +NUMBER
* subtract from value -NUMBER
* xor with value ^NUMBER
* byteswap (u64) @0
Use with care!
Signed-off-by: David Sterba <dsterba@suse.com>