Below is a modified magic entry to show the feature flags in the BTRFS superblock. It also removes the leafsize field due to the following comment in the documentation of the superblock. Also note that in the kernel header for this the field is named __unused_leafsize. pub node_size: u32, /// Unused and must be equal to `nodesize` pub leafsize: u32, 0x10040 string _BHRfS_M BTRFS Filesystem