VM_PAGER_PUT_SYNC
const int zfs_vm_pagerput_sync = VM_PAGER_PUT_SYNC;
async = curproc == pageproc && (flags & VM_PAGER_PUT_SYNC) == 0;
VM_PAGER_PUT_SYNC : VM_PAGER_CLUSTER_OK;
VOP_FSYNC(vp, (pagerflags & VM_PAGER_PUT_SYNC) ? MNT_WAIT : 0);
flags |= VM_PAGER_PUT_SYNC;
if ((pager_flags & (VM_PAGER_PUT_SYNC | VM_PAGER_PUT_INVAL)) != 0)