PFN_SIG_LEN
u8 signature[PFN_SIG_LEN];
if (memcmp(pfn_sb->signature, sig, PFN_SIG_LEN) != 0)
!memcmp(pfn_sb->signature, DAX_SIG, PFN_SIG_LEN)) {
memcpy(pfn_sb->signature, sig, PFN_SIG_LEN);