pte = pte_mkold(mk_pte(new, vma->vm_page_prot));
if (pte_swp_soft_dirty(*ptep))
pte = pte_mksoft_dirty(pte);
+
+ /* Recheck VMA as permissions can change since migration started */
if (is_write_migration_entry(entry))
- pte = pte_mkwrite(pte);
+ pte = maybe_mkwrite(pte, vma);
+
#ifdef CONFIG_HUGETLB_PAGE
if (PageHuge(new)) {
pte = pte_mkhuge(pte);
}
/*
+ * Congratulations to trinity for discovering this bug.
+ * mm/fremap.c's remap_file_pages() accepts any range within a single vma to
+ * convert that vma to VM_NONLINEAR; and generic_file_remap_pages() will then
+ * replace the specified range by file ptes throughout (maybe populated after).
+ * If page migration finds a page within that range, while it's still located
+ * by vma_interval_tree rather than lost to i_mmap_nonlinear list, no problem:
+ * zap_pte() clears the temporary migration entry before mmap_sem is dropped.
+ * But if the migrating page is in a part of the vma outside the range to be
+ * remapped, then it will not be cleared, and remove_migration_ptes() needs to
+ * deal with it. Fortunately, this part of the vma is of course still linear,
+ * so we just need to use linear location on the nonlinear list.
+ */
+static int remove_linear_migration_ptes_from_nonlinear(struct page *page,
+ struct address_space *mapping, void *arg)
+{
+ struct vm_area_struct *vma;
+ /* hugetlbfs does not support remap_pages, so no huge pgoff worries */
+ pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ unsigned long addr;
+
+ list_for_each_entry(vma,
+ &mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+ addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ if (addr >= vma->vm_start && addr < vma->vm_end)
+ remove_migration_pte(page, vma, addr, arg);
+ }
+ return SWAP_AGAIN;
+}
+
+/*
* Get rid of all migration entries and replace them by
* references to the indicated page.
*/
struct rmap_walk_control rwc = {
.rmap_one = remove_migration_pte,
.arg = old,
+ .file_nonlinear = remove_linear_migration_ptes_from_nonlinear,
};
rmap_walk(new, &rwc);
* Obtain the lock on page, remove all ptes and migrate the page
* to the newly allocated page in newpage.
*/
-static int unmap_and_move(new_page_t get_new_page, unsigned long private,
- struct page *page, int force, enum migrate_mode mode)
+static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page,
+ unsigned long private, struct page *page, int force,
+ enum migrate_mode mode)
{
int rc = 0;
int *result = NULL;
page_is_file_cache(page));
putback_lru_page(page);
}
+
/*
- * Move the new page to the LRU. If migration was not successful
- * then this will free the page.
+ * If migration was not successful and there's a freeing callback, use
+ * it. Otherwise, putback_lru_page() will drop the reference grabbed
+ * during isolation.
*/
- putback_lru_page(newpage);
+ if (rc != MIGRATEPAGE_SUCCESS && put_new_page) {
+ ClearPageSwapBacked(newpage);
+ put_new_page(newpage, private);
+ } else
+ putback_lru_page(newpage);
+
if (result) {
if (rc)
*result = rc;
* will wait in the page fault for migration to complete.
*/
static int unmap_and_move_huge_page(new_page_t get_new_page,
- unsigned long private, struct page *hpage,
- int force, enum migrate_mode mode)
+ free_page_t put_new_page, unsigned long private,
+ struct page *hpage, int force,
+ enum migrate_mode mode)
{
int rc = 0;
int *result = NULL;
if (!page_mapped(hpage))
rc = move_to_new_page(new_hpage, hpage, 1, mode);
- if (rc)
+ if (rc != MIGRATEPAGE_SUCCESS)
remove_migration_ptes(hpage, hpage);
if (anon_vma)
put_anon_vma(anon_vma);
- if (!rc)
+ if (rc == MIGRATEPAGE_SUCCESS)
hugetlb_cgroup_migrate(hpage, new_hpage);
unlock_page(hpage);
out:
if (rc != -EAGAIN)
putback_active_hugepage(hpage);
- put_page(new_hpage);
+
+ /*
+ * If migration was not successful and there's a freeing callback, use
+ * it. Otherwise, put_page() will drop the reference grabbed during
+ * isolation.
+ */
+ if (rc != MIGRATEPAGE_SUCCESS && put_new_page)
+ put_new_page(new_hpage, private);
+ else
+ put_page(new_hpage);
+
if (result) {
if (rc)
*result = rc;
* @from: The list of pages to be migrated.
* @get_new_page: The function used to allocate free pages to be used
* as the target of the page migration.
+ * @put_new_page: The function used to free target pages if migration
+ * fails, or NULL if no special handling is necessary.
* @private: Private data to be passed on to get_new_page()
* @mode: The migration mode that specifies the constraints for
* page migration, if any.
* Returns the number of pages that were not migrated, or an error code.
*/
int migrate_pages(struct list_head *from, new_page_t get_new_page,
- unsigned long private, enum migrate_mode mode, int reason)
+ free_page_t put_new_page, unsigned long private,
+ enum migrate_mode mode, int reason)
{
int retry = 1;
int nr_failed = 0;
if (PageHuge(page))
rc = unmap_and_move_huge_page(get_new_page,
- private, page, pass > 2, mode);
+ put_new_page, private, page,
+ pass > 2, mode);
else
- rc = unmap_and_move(get_new_page, private,
- page, pass > 2, mode);
+ rc = unmap_and_move(get_new_page, put_new_page,
+ private, page, pass > 2, mode);
switch(rc) {
case -ENOMEM:
err = 0;
if (!list_empty(&pagelist)) {
- err = migrate_pages(&pagelist, new_page_node,
+ err = migrate_pages(&pagelist, new_page_node, NULL,
(unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL);
if (err)
putback_movable_pages(&pagelist);
list_add(&page->lru, &migratepages);
nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page,
- node, MIGRATE_ASYNC, MR_NUMA_MISPLACED);
+ NULL, node, MIGRATE_ASYNC,
+ MR_NUMA_MISPLACED);
if (nr_remaining) {
if (!list_empty(&migratepages)) {
list_del(&page->lru);
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff