diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 11fe0b4dbe6730e0bdd9c5cb987c4d93feb45df7..693c0ff2256c91cd65aaa87ed0fe8d9b9210365b 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1255,263 +1255,63 @@ unlock:
spin_unlock(vmf->ptl);
}
-static vm_fault_t do_huge_pmd_wp_page_fallback(struct vm_fault *vmf,
- pmd_t orig_pmd, struct page *page)
-{
- struct vm_area_struct *vma = vmf->vma;
- unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
- struct mem_cgroup *memcg;
- pgtable_t pgtable;
- pmd_t _pmd;
- int i;
- vm_fault_t ret = 0;
- struct page **pages;
- struct mmu_notifier_range range;
-
- pages = kmalloc_array(HPAGE_PMD_NR, sizeof(struct page *),
- GFP_KERNEL);
- if (unlikely(!pages)) {
- ret |= VM_FAULT_OOM;
- goto out;
- }
-
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- pages[i] = alloc_page_vma_node(GFP_HIGHUSER_MOVABLE, vma,
- vmf->address, page_to_nid(page));
- if (unlikely(!pages[i] ||
- mem_cgroup_try_charge_delay(pages[i], vma->vm_mm,
- GFP_KERNEL, &memcg, false))) {
- if (pages[i])
- put_page(pages[i]);
- while (--i >= 0) {
- memcg = (void *)page_private(pages[i]);
- set_page_private(pages[i], 0);
- mem_cgroup_cancel_charge(pages[i], memcg,
- false);
- put_page(pages[i]);
- }
- kfree(pages);
- ret |= VM_FAULT_OOM;
- goto out;
- }
- set_page_private(pages[i], (unsigned long)memcg);
- }
-
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- copy_user_highpage(pages[i], page + i,
- haddr + PAGE_SIZE * i, vma);
- __SetPageUptodate(pages[i]);
- cond_resched();
- }
-
- mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
- haddr, haddr + HPAGE_PMD_SIZE);
- mmu_notifier_invalidate_range_start(&range);
-
- vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd);
- if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
- goto out_free_pages;
- VM_BUG_ON_PAGE(!PageHead(page), page);
-
- /*
- * Leave pmd empty until pte is filled note we must notify here as
- * concurrent CPU thread might write to new page before the call to
- * mmu_notifier_invalidate_range_end() happens which can lead to a
- * device seeing memory write in different order than CPU.
- *
- * See Documentation/vm/mmu_notifier.rst
- */
- pmdp_huge_clear_flush_notify(vma, haddr, vmf->pmd);
-
- pgtable = pgtable_trans_huge_withdraw(vma->vm_mm, vmf->pmd);
- pmd_populate(vma->vm_mm, &_pmd, pgtable);
-
- for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
- pte_t entry;
- entry = mk_pte(pages[i], vma->vm_page_prot);
- entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- memcg = (void *)page_private(pages[i]);
- set_page_private(pages[i], 0);
- page_add_new_anon_rmap(pages[i], vmf->vma, haddr, false);
- mem_cgroup_commit_charge(pages[i], memcg, false, false);
- lru_cache_add_active_or_unevictable(pages[i], vma);
- vmf->pte = pte_offset_map(&_pmd, haddr);
- VM_BUG_ON(!pte_none(*vmf->pte));
- set_pte_at(vma->vm_mm, haddr, vmf->pte, entry);
- pte_unmap(vmf->pte);
- }
- kfree(pages);
-
- smp_wmb(); /* make pte visible before pmd */
- pmd_populate(vma->vm_mm, vmf->pmd, pgtable);
- page_remove_rmap(page, true);
- spin_unlock(vmf->ptl);
-
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above pmdp_huge_clear_flush_notify() did already call it.
- */
- mmu_notifier_invalidate_range_only_end(&range);
-
- ret |= VM_FAULT_WRITE;
- put_page(page);
-
-out:
- return ret;
-
-out_free_pages:
- spin_unlock(vmf->ptl);
- mmu_notifier_invalidate_range_end(&range);
- for (i = 0; i < HPAGE_PMD_NR; i++) {
- memcg = (void *)page_private(pages[i]);
- set_page_private(pages[i], 0);
- mem_cgroup_cancel_charge(pages[i], memcg, false);
- put_page(pages[i]);
- }
- kfree(pages);
- goto out;
-}
-
vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd)
{
struct vm_area_struct *vma = vmf->vma;
- struct page *page = NULL, *new_page;
- struct mem_cgroup *memcg;
+ struct page *page;
unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
- struct mmu_notifier_range range;
- gfp_t huge_gfp; /* for allocation and charge */
- vm_fault_t ret = 0;
vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd);
VM_BUG_ON_VMA(!vma->anon_vma, vma);
+
if (is_huge_zero_pmd(orig_pmd))
- goto alloc;
+ goto fallback;
+
spin_lock(vmf->ptl);
- if (unlikely(!pmd_same(*vmf->pmd, orig_pmd)))
- goto out_unlock;
+
+ if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) {
+ spin_unlock(vmf->ptl);
+ return 0;
+ }
page = pmd_page(orig_pmd);
VM_BUG_ON_PAGE(!PageCompound(page) || !PageHead(page), page);
- /*
- * We can only reuse the page if nobody else maps the huge page or it's
- * part.
- */
+
+ /* Lock page for reuse_swap_page() */
if (!trylock_page(page)) {
get_page(page);
spin_unlock(vmf->ptl);
lock_page(page);
spin_lock(vmf->ptl);
if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) {
+ spin_unlock(vmf->ptl);
unlock_page(page);
put_page(page);
- goto out_unlock;
+ return 0;
}
put_page(page);
}
+
+ /*
+ * We can only reuse the page if nobody else maps the huge page or it's
+ * part.
+ */
if (reuse_swap_page(page, NULL)) {
pmd_t entry;
entry = pmd_mkyoung(orig_pmd);
entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1))
+ if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1))
update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
- ret |= VM_FAULT_WRITE;
unlock_page(page);
- goto out_unlock;
- }
- unlock_page(page);
- get_page(page);
- spin_unlock(vmf->ptl);
-alloc:
- if (__transparent_hugepage_enabled(vma) &&
- !transparent_hugepage_debug_cow()) {
- huge_gfp = alloc_hugepage_direct_gfpmask(vma);
- new_page = alloc_hugepage_vma(huge_gfp, vma, haddr, HPAGE_PMD_ORDER);
- } else
- new_page = NULL;
-
- if (likely(new_page)) {
- prep_transhuge_page(new_page);
- } else {
- if (!page) {
- split_huge_pmd(vma, vmf->pmd, vmf->address);
- ret |= VM_FAULT_FALLBACK;
- } else {
- ret = do_huge_pmd_wp_page_fallback(vmf, orig_pmd, page);
- if (ret & VM_FAULT_OOM) {
- split_huge_pmd(vma, vmf->pmd, vmf->address);
- ret |= VM_FAULT_FALLBACK;
- }
- put_page(page);
- }
- count_vm_event(THP_FAULT_FALLBACK);
- goto out;
- }
-
- if (unlikely(mem_cgroup_try_charge_delay(new_page, vma->vm_mm,
- huge_gfp, &memcg, true))) {
- put_page(new_page);
- split_huge_pmd(vma, vmf->pmd, vmf->address);
- if (page)
- put_page(page);
- ret |= VM_FAULT_FALLBACK;
- count_vm_event(THP_FAULT_FALLBACK);
- count_vm_event(THP_FAULT_FALLBACK_CHARGE);
- goto out;
- }
-
- count_vm_event(THP_FAULT_ALLOC);
- count_memcg_events(memcg, THP_FAULT_ALLOC, 1);
-
- if (!page)
- clear_huge_page(new_page, vmf->address, HPAGE_PMD_NR);
- else
- copy_user_huge_page(new_page, page, vmf->address,
- vma, HPAGE_PMD_NR);
- __SetPageUptodate(new_page);
-
- mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
- haddr, haddr + HPAGE_PMD_SIZE);
- mmu_notifier_invalidate_range_start(&range);
-
- spin_lock(vmf->ptl);
- if (page)
- put_page(page);
- if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) {
spin_unlock(vmf->ptl);
- mem_cgroup_cancel_charge(new_page, memcg, true);
- put_page(new_page);
- goto out_mn;
- } else {
- pmd_t entry;
- entry = mk_huge_pmd(new_page, vma->vm_page_prot);
- entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
- pmdp_huge_clear_flush_notify(vma, haddr, vmf->pmd);
- page_add_new_anon_rmap(new_page, vma, haddr, true);
- mem_cgroup_commit_charge(new_page, memcg, false, true);
- lru_cache_add_active_or_unevictable(new_page, vma);
- set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry);
- update_mmu_cache_pmd(vma, vmf->address, vmf->pmd);
- if (!page) {
- add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR);
- } else {
- VM_BUG_ON_PAGE(!PageHead(page), page);
- page_remove_rmap(page, true);
- put_page(page);
- }
- ret |= VM_FAULT_WRITE;
+ return VM_FAULT_WRITE;
}
+
+ unlock_page(page);
spin_unlock(vmf->ptl);
-out_mn:
- /*
- * No need to double call mmu_notifier->invalidate_range() callback as
- * the above pmdp_huge_clear_flush_notify() did already call it.
- */
- mmu_notifier_invalidate_range_only_end(&range);
-out:
- return ret;
-out_unlock:
- spin_unlock(vmf->ptl);
- return ret;
+fallback:
+ __split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL);
+ return VM_FAULT_FALLBACK;
}
/*