+void
+mem_sync_pages(ptr_t mnt,
+ struct mm_region* region,
+ ptr_t start,
+ ptr_t length,
+ int options)
+{
+ if (!region->mfile || !(region->attr & REGION_WSHARED)) {
+ return;
+ }
+
+ v_mapping mapping;
+ for (size_t i = 0; i < length; i += PG_SIZE) {
+ if (!vmm_lookupat(mnt, start + i, &mapping)) {
+ continue;
+ }
+
+ if (PG_IS_DIRTY(*mapping.pte)) {
+ size_t offset = mapping.va - region->start + region->foff;
+ struct v_inode* inode = region->mfile->inode;
+
+ region->mfile->ops->write_page(
+ inode, (void*)mapping.va, PG_SIZE, offset);
+
+ *mapping.pte &= ~PG_DIRTY;
+
+ cpu_flush_page((ptr_t)mapping.pte);
+ } else if ((options & MS_INVALIDATE)) {
+ goto invalidate;
+ }
+
+ if (options & MS_INVALIDATE_ALL) {
+ goto invalidate;
+ }
+
+ continue;
+
+ invalidate:
+ *mapping.pte &= ~PG_PRESENT;
+ pmm_free_page(KERNEL_PID, mapping.pa);
+ cpu_flush_page((ptr_t)mapping.pte);
+ }
+}
+
+int
+mem_msync(ptr_t mnt,
+ vm_regions_t* regions,
+ ptr_t addr,
+ size_t length,
+ int options)
+{
+ struct mm_region* pos = list_entry(regions->next, struct mm_region, head);
+ while (length && (ptr_t)&pos->head != (ptr_t)regions) {
+ if (pos->end >= addr && pos->start <= addr) {
+ size_t l = MIN(length, pos->end - addr);
+ mem_sync_pages(mnt, pos, addr, l, options);
+
+ addr += l;
+ length -= l;
+ }
+ pos = list_entry(pos->head.next, struct mm_region, head);
+ }
+
+ if (length) {
+ return ENOMEM;
+ }
+
+ return 0;
+}
+
+void
+mem_unmap_region(ptr_t mnt, struct mm_region* region)
+{
+ size_t len = ROUNDUP(region->end - region->start, PG_SIZE);
+ mem_sync_pages(mnt, region, region->start, len, 0);
+
+ for (size_t i = region->start; i <= region->end; i += PG_SIZE) {
+ ptr_t pa = vmm_del_mapping(mnt, i);
+ if (pa) {
+ pmm_free_page(__current->pid, pa);
+ }
+ }
+ llist_delete(®ion->head);
+ region_release(region);
+}
+
+int
+mem_unmap(ptr_t mnt, vm_regions_t* regions, ptr_t addr, size_t length)