FGP_WRITE
fgf_t fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_NOFS,
#define FGP_WRITEBEGIN (FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE)
else if (fgp_flags & FGP_WRITE) {
if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping))