X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fmemory.c;h=2a8430844b6dc5b2a4ef4c4a28a4723c5f5937cc;hb=557ed1fa2620dc119adb86b34c614e152a629a80;hp=ca8cac11bd2cf4930533f306a0209bbbea0e9c31;hpb=644b55ce889edd37d6406df26e2d96d7a7390749;p=linux-2.6

diff --git a/mm/memory.c b/mm/memory.c
index ca8cac11bd..2a8430844b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -966,7 +966,7 @@ no_page_table:
 	 * has touched so far, we don't want to allocate page tables.
 	 */
 	if (flags & FOLL_ANON) {
-		page = ZERO_PAGE(address);
+		page = ZERO_PAGE(0);
 		if (flags & FOLL_GET)
 			get_page(page);
 		BUG_ON(flags & FOLL_WRITE);
@@ -1111,95 +1111,6 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 }
 EXPORT_SYMBOL(get_user_pages);
 
-static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd,
-			unsigned long addr, unsigned long end, pgprot_t prot)
-{
-	pte_t *pte;
-	spinlock_t *ptl;
-	int err = 0;
-
-	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
-	if (!pte)
-		return -EAGAIN;
-	arch_enter_lazy_mmu_mode();
-	do {
-		struct page *page = ZERO_PAGE(addr);
-		pte_t zero_pte = pte_wrprotect(mk_pte(page, prot));
-
-		if (unlikely(!pte_none(*pte))) {
-			err = -EEXIST;
-			pte++;
-			break;
-		}
-		page_cache_get(page);
-		page_add_file_rmap(page);
-		inc_mm_counter(mm, file_rss);
-		set_pte_at(mm, addr, pte, zero_pte);
-	} while (pte++, addr += PAGE_SIZE, addr != end);
-	arch_leave_lazy_mmu_mode();
-	pte_unmap_unlock(pte - 1, ptl);
-	return err;
-}
-
-static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud,
-			unsigned long addr, unsigned long end, pgprot_t prot)
-{
-	pmd_t *pmd;
-	unsigned long next;
-	int err;
-
-	pmd = pmd_alloc(mm, pud, addr);
-	if (!pmd)
-		return -EAGAIN;
-	do {
-		next = pmd_addr_end(addr, end);
-		err = zeromap_pte_range(mm, pmd, addr, next, prot);
-		if (err)
-			break;
-	} while (pmd++, addr = next, addr != end);
-	return err;
-}
-
-static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd,
-			unsigned long addr, unsigned long end, pgprot_t prot)
-{
-	pud_t *pud;
-	unsigned long next;
-	int err;
-
-	pud = pud_alloc(mm, pgd, addr);
-	if (!pud)
-		return -EAGAIN;
-	do {
-		next = pud_addr_end(addr, end);
-		err = zeromap_pmd_range(mm, pud, addr, next, prot);
-		if (err)
-			break;
-	} while (pud++, addr = next, addr != end);
-	return err;
-}
-
-int zeromap_page_range(struct vm_area_struct *vma,
-			unsigned long addr, unsigned long size, pgprot_t prot)
-{
-	pgd_t *pgd;
-	unsigned long next;
-	unsigned long end = addr + size;
-	struct mm_struct *mm = vma->vm_mm;
-	int err;
-
-	BUG_ON(addr >= end);
-	pgd = pgd_offset(mm, addr);
-	flush_cache_range(vma, addr, end);
-	do {
-		next = pgd_addr_end(addr, end);
-		err = zeromap_pud_range(mm, pgd, addr, next, prot);
-		if (err)
-			break;
-	} while (pgd++, addr = next, addr != end);
-	return err;
-}
-
 pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
 {
 	pgd_t * pgd = pgd_offset(mm, addr);
@@ -1639,6 +1550,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	struct page *old_page, *new_page;
 	pte_t entry;
 	int reuse = 0, ret = 0;
+	int page_mkwrite = 0;
 	struct page *dirty_page = NULL;
 
 	old_page = vm_normal_page(vma, address, orig_pte);
@@ -1687,6 +1599,8 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			page_cache_release(old_page);
 			if (!pte_same(*page_table, orig_pte))
 				goto unlock;
+
+			page_mkwrite = 1;
 		}
 		dirty_page = old_page;
 		get_page(dirty_page);
@@ -1714,16 +1628,11 @@ gotten:
 
 	if (unlikely(anon_vma_prepare(vma)))
 		goto oom;
-	if (old_page == ZERO_PAGE(address)) {
-		new_page = alloc_zeroed_user_highpage_movable(vma, address);
-		if (!new_page)
-			goto oom;
-	} else {
-		new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
-		if (!new_page)
-			goto oom;
-		cow_user_page(new_page, old_page, address, vma);
-	}
+	VM_BUG_ON(old_page == ZERO_PAGE(0));
+	new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+	if (!new_page)
+		goto oom;
+	cow_user_page(new_page, old_page, address, vma);
 
 	/*
 	 * Re-check the pte - we dropped the lock
@@ -1774,7 +1683,7 @@ unlock:
 		 * do_no_page is protected similarly.
 		 */
 		wait_on_page_locked(dirty_page);
-		set_page_dirty_balance(dirty_page);
+		set_page_dirty_balance(dirty_page, page_mkwrite);
 		put_page(dirty_page);
 	}
 	return ret;
@@ -2249,39 +2158,24 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	spinlock_t *ptl;
 	pte_t entry;
 
-	if (write_access) {
-		/* Allocate our own private page. */
-		pte_unmap(page_table);
-
-		if (unlikely(anon_vma_prepare(vma)))
-			goto oom;
-		page = alloc_zeroed_user_highpage_movable(vma, address);
-		if (!page)
-			goto oom;
-
-		entry = mk_pte(page, vma->vm_page_prot);
-		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+	/* Allocate our own private page. */
+	pte_unmap(page_table);
 
-		page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
-		if (!pte_none(*page_table))
-			goto release;
-		inc_mm_counter(mm, anon_rss);
-		lru_cache_add_active(page);
-		page_add_new_anon_rmap(page, vma, address);
-	} else {
-		/* Map the ZERO_PAGE - vm_page_prot is readonly */
-		page = ZERO_PAGE(address);
-		page_cache_get(page);
-		entry = mk_pte(page, vma->vm_page_prot);
+	if (unlikely(anon_vma_prepare(vma)))
+		goto oom;
+	page = alloc_zeroed_user_highpage_movable(vma, address);
+	if (!page)
+		goto oom;
 
-		ptl = pte_lockptr(mm, pmd);
-		spin_lock(ptl);
-		if (!pte_none(*page_table))
-			goto release;
-		inc_mm_counter(mm, file_rss);
-		page_add_file_rmap(page);
-	}
+	entry = mk_pte(page, vma->vm_page_prot);
+	entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
+	page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+	if (!pte_none(*page_table))
+		goto release;
+	inc_mm_counter(mm, anon_rss);
+	lru_cache_add_active(page);
+	page_add_new_anon_rmap(page, vma, address);
 	set_pte_at(mm, address, page_table, entry);
 
 	/* No need to invalidate - it was non-present before */
@@ -2307,13 +2201,14 @@ oom:
  * do not need to flush old virtual caches or the TLB.
  *
  * We enter with non-exclusive mmap_sem (to exclude vma changes,
- * but allow concurrent faults), and pte mapped but not yet locked.
+ * but allow concurrent faults), and pte neither mapped nor locked.
  * We return with mmap_sem still held, but pte unmapped and unlocked.
  */
 static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-		unsigned long address, pte_t *page_table, pmd_t *pmd,
+		unsigned long address, pmd_t *pmd,
 		pgoff_t pgoff, unsigned int flags, pte_t orig_pte)
 {
+	pte_t *page_table;
 	spinlock_t *ptl;
 	struct page *page;
 	pte_t entry;
@@ -2321,13 +2216,13 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	struct page *dirty_page = NULL;
 	struct vm_fault vmf;
 	int ret;
+	int page_mkwrite = 0;
 
 	vmf.virtual_address = (void __user *)(address & PAGE_MASK);
 	vmf.pgoff = pgoff;
 	vmf.flags = flags;
 	vmf.page = NULL;
 
-	pte_unmap(page_table);
 	BUG_ON(vma->vm_flags & VM_PFNMAP);
 
 	if (likely(vma->vm_ops->fault)) {
@@ -2398,6 +2293,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 					anon = 1; /* no anon but release vmf.page */
 					goto out;
 				}
+				page_mkwrite = 1;
 			}
 		}
 
@@ -2453,7 +2349,7 @@ out_unlocked:
 	if (anon)
 		page_cache_release(vmf.page);
 	else if (dirty_page) {
-		set_page_dirty_balance(dirty_page);
+		set_page_dirty_balance(dirty_page, page_mkwrite);
 		put_page(dirty_page);
 	}
 
@@ -2468,8 +2364,8 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 			- vma->vm_start) >> PAGE_CACHE_SHIFT) + vma->vm_pgoff;
 	unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
 
-	return __do_fault(mm, vma, address, page_table, pmd, pgoff,
-							flags, orig_pte);
+	pte_unmap(page_table);
+	return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
 }
 
 
@@ -2552,9 +2448,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	}
 
 	pgoff = pte_to_pgoff(orig_pte);
-
-	return __do_fault(mm, vma, address, page_table, pmd, pgoff,
-							flags, orig_pte);
+	return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
 }
 
 /*