[RFC][PATCH] page->mapping clarification [2/3] changes in /mm
From: KAMEZAWA Hiroyuki
Date: Wed Sep 19 2007 - 03:43:44 EST
Make use of page-cache.h functions in /mm layer.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
---
mm/filemap.c | 19 ++++++++++---------
mm/memory.c | 5 +++--
mm/migrate.c | 8 ++------
mm/page-writeback.c | 4 ++--
mm/rmap.c | 36 ++++++++++++++----------------------
mm/shmem.c | 4 ++--
mm/truncate.c | 15 ++++++++-------
7 files changed, 41 insertions(+), 50 deletions(-)
Index: linux-2.6.23-rc6-mm1/mm/filemap.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/filemap.c
+++ linux-2.6.23-rc6-mm1/mm/filemap.c
@@ -115,7 +115,7 @@ generic_file_direct_IO(int rw, struct ki
*/
void __remove_from_page_cache(struct page *page)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
mem_container_uncharge_page(page);
radix_tree_delete(&mapping->page_tree, page->index);
@@ -127,7 +127,7 @@ void __remove_from_page_cache(struct pag
void remove_from_page_cache(struct page *page)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
BUG_ON(!PageLocked(page));
@@ -641,7 +641,7 @@ repeat:
__lock_page(page);
/* Has the page been truncated while we slept? */
- if (unlikely(page->mapping != mapping)) {
+ if (unlikely(!is_page_consistent(page, mapping))) {
unlock_page(page);
page_cache_release(page);
goto repeat;
@@ -750,7 +750,7 @@ unsigned find_get_pages_contig(struct ad
ret = radix_tree_gang_lookup(&mapping->page_tree,
(void **)pages, index, nr_pages);
for (i = 0; i < ret; i++) {
- if (pages[i]->mapping == NULL || pages[i]->index != index)
+ if (!page_is_pagecache(pages[i]) || pages[i]->index != index)
break;
page_cache_get(pages[i]);
@@ -979,7 +979,7 @@ page_not_up_to_date:
lock_page(page);
/* Did it get truncated before we got the lock? */
- if (!page->mapping) {
+ if (!page_is_pagecache(page)) {
unlock_page(page);
page_cache_release(page);
continue;
@@ -1006,7 +1006,7 @@ readpage:
if (!PageUptodate(page)) {
lock_page(page);
if (!PageUptodate(page)) {
- if (page->mapping == NULL) {
+ if (!page_is_pagecache(page)) {
/*
* invalidate_inode_pages got it
*/
@@ -1545,7 +1545,7 @@ retry:
goto out;
lock_page(page);
- if (!page->mapping) {
+ if (!page_is_pagecache(page)) {
unlock_page(page);
page_cache_release(page);
goto retry;
@@ -2112,7 +2112,8 @@ static ssize_t generic_perform_write_2co
* use a non-zeroing copy, but the APIs aren't too
* consistent.
*/
- if (unlikely(!page->mapping || PageUptodate(page))) {
+ if (unlikely(!page_is_pagecache(page) ||
+ PageUptodate(page))) {
unlock_page(page);
page_cache_release(page);
page_cache_release(src_page);
@@ -2555,7 +2556,7 @@ out:
*/
int try_to_release_page(struct page *page, gfp_t gfp_mask)
{
- struct address_space * const mapping = page->mapping;
+ struct address_space * const mapping = page_mapping_cache(page);
BUG_ON(!PageLocked(page));
if (PageWriteback(page))
Index: linux-2.6.23-rc6-mm1/mm/memory.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/memory.c
+++ linux-2.6.23-rc6-mm1/mm/memory.c
@@ -650,7 +650,8 @@ static unsigned long zap_pte_range(struc
* unmap shared but keep private pages.
*/
if (details->check_mapping &&
- details->check_mapping != page->mapping)
+ !is_page_consistent(page,
+ details->check_mapping))
continue;
/*
* Each page->index must be checked when
@@ -2310,7 +2311,7 @@ static int __do_fault(struct mm_struct *
* reworking page_mkwrite locking API, which
* is better done later.
*/
- if (!page->mapping) {
+ if (!page_is_pagecache(page)) {
ret = 0;
anon = 1; /* no anon but release vmf.page */
goto out;
Index: linux-2.6.23-rc6-mm1/mm/migrate.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/migrate.c
+++ linux-2.6.23-rc6-mm1/mm/migrate.c
@@ -223,17 +223,13 @@ static void remove_anon_migration_ptes(s
{
struct anon_vma *anon_vma;
struct vm_area_struct *vma;
- unsigned long mapping;
-
- mapping = (unsigned long)new->mapping;
- if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
+ anon_vma = page_mapping_anon(new);
+ if (!anon_vma)
return;
-
/*
* We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
*/
- anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
spin_lock(&anon_vma->lock);
list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
Index: linux-2.6.23-rc6-mm1/mm/page-writeback.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/page-writeback.c
+++ linux-2.6.23-rc6-mm1/mm/page-writeback.c
@@ -832,7 +832,7 @@ retry:
*/
lock_page(page);
- if (unlikely(page->mapping != mapping)) {
+ if (unlikely(!is_page_consistent(page, mapping))) {
unlock_page(page);
continue;
}
@@ -940,7 +940,7 @@ int do_writepages(struct address_space *
*/
int write_one_page(struct page *page, int wait)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
int ret = 0;
struct writeback_control wbc = {
.sync_mode = WB_SYNC_ALL,
Index: linux-2.6.23-rc6-mm1/mm/rmap.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/rmap.c
+++ linux-2.6.23-rc6-mm1/mm/rmap.c
@@ -159,16 +159,13 @@ void __init anon_vma_init(void)
static struct anon_vma *page_lock_anon_vma(struct page *page)
{
struct anon_vma *anon_vma;
- unsigned long anon_mapping;
rcu_read_lock();
- anon_mapping = (unsigned long) page->mapping;
- if (!(anon_mapping & PAGE_MAPPING_ANON))
+ anon_vma = page_mapping_anon(page);
+ if (!anon_vma)
goto out;
if (!page_mapped(page))
goto out;
-
- anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
spin_lock(&anon_vma->lock);
return anon_vma;
out:
@@ -207,12 +204,11 @@ vma_address(struct page *page, struct vm
unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
{
if (PageAnon(page)) {
- if ((void *)vma->anon_vma !=
- (void *)page->mapping - PAGE_MAPPING_ANON)
+ if (vma->anon_vma != page_mapping_anon(page))
return -EFAULT;
- } else if (page->mapping && !(vma->vm_flags & VM_NONLINEAR)) {
+ } else if (page_is_pagecache(page) && !(vma->vm_flags & VM_NONLINEAR)) {
if (!vma->vm_file ||
- vma->vm_file->f_mapping != page->mapping)
+ !is_page_consistent(page, vma->vm_file->f_mapping))
return -EFAULT;
} else
return -EFAULT;
@@ -333,9 +329,9 @@ static int page_referenced_anon(struct p
* @page: the page we're checking references on.
*
* For an object-based mapped page, find all the places it is mapped and
- * check/clear the referenced flag. This is done by following the page->mapping
- * pointer, then walking the chain of vmas it holds. It returns the number
- * of references it found.
+ * check/clear the referenced flag. This is done by following the
+ * address_space of page_maping_cache(), then walking the chain of vmas it
+ * holds. It returns the number of references it found.
*
* This function is only called from page_referenced for object-based pages.
*/
@@ -343,18 +339,16 @@ static int page_referenced_file(struct p
struct mem_container *mem_cont)
{
unsigned int mapcount;
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma;
struct prio_tree_iter iter;
int referenced = 0;
/*
- * The caller's checks on page->mapping and !PageAnon have made
- * sure that this is a file page: the check for page->mapping
- * excludes the case just before it gets set on an anon page.
+ * Make sure this is a file page.
*/
- BUG_ON(PageAnon(page));
+ BUG_ON(!mapping);
/*
* The page lock not only makes sure that page->mapping cannot
@@ -421,7 +415,7 @@ int page_referenced(struct page *page, i
else if (TestSetPageLocked(page))
referenced++;
else {
- if (page->mapping)
+ if (page_is_pagecache(page))
referenced +=
page_referenced_file(page, mem_cont);
unlock_page(page);
@@ -546,9 +540,7 @@ static void __page_check_anon_rmap(struc
* are initially only visible via the pagetables, and the pte is locked
* over the call to page_add_new_anon_rmap.
*/
- struct anon_vma *anon_vma = vma->anon_vma;
- anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
- BUG_ON(page->mapping != (struct address_space *)anon_vma);
+ BUG_ON(vma->anon_vma != page_mapping_anon(page));
BUG_ON(page->index != linear_page_index(vma, address));
#endif
}
@@ -893,7 +885,7 @@ static int try_to_unmap_anon(struct page
*/
static int try_to_unmap_file(struct page *page, int migration)
{
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
struct vm_area_struct *vma;
struct prio_tree_iter iter;
Index: linux-2.6.23-rc6-mm1/mm/shmem.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/shmem.c
+++ linux-2.6.23-rc6-mm1/mm/shmem.c
@@ -917,7 +917,7 @@ static int shmem_writepage(struct page *
BUG_ON(!PageLocked(page));
BUG_ON(page_mapped(page));
- mapping = page->mapping;
+ mapping = page_mapping_cache(page);
index = page->index;
inode = mapping->host;
info = SHMEM_I(inode);
@@ -1454,7 +1454,7 @@ static const struct inode_operations shm
*/
static int shmem_readpage(struct file *file, struct page *page)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = page_inode(page);
int error = shmem_getpage(inode, page->index, &page, SGP_CACHE, NULL);
unlock_page(page);
return error;
Index: linux-2.6.23-rc6-mm1/mm/truncate.c
===================================================================
--- linux-2.6.23-rc6-mm1.orig/mm/truncate.c
+++ linux-2.6.23-rc6-mm1/mm/truncate.c
@@ -37,7 +37,7 @@
void do_invalidatepage(struct page *page, unsigned long offset)
{
void (*invalidatepage)(struct page *, unsigned long);
- invalidatepage = page->mapping->a_ops->invalidatepage;
+ invalidatepage = page_mapping_cache(page)->a_ops->invalidatepage;
#ifdef CONFIG_BLOCK
if (!invalidatepage)
invalidatepage = block_invalidatepage;
@@ -70,7 +70,7 @@ static inline void truncate_partial_page
void cancel_dirty_page(struct page *page, unsigned int account_size)
{
if (TestClearPageDirty(page)) {
- struct address_space *mapping = page->mapping;
+ struct address_space *mapping = page_mapping_cache(page);
if (mapping && mapping_cap_account_dirty(mapping)) {
dec_zone_page_state(page, NR_FILE_DIRTY);
dec_bdi_stat(mapping->backing_dev_info,
@@ -95,7 +95,7 @@ EXPORT_SYMBOL(cancel_dirty_page);
static void
truncate_complete_page(struct address_space *mapping, struct page *page)
{
- if (page->mapping != mapping)
+ if (!is_page_consistent(page, mapping))
return;
cancel_dirty_page(page, PAGE_CACHE_SIZE);
@@ -122,7 +122,7 @@ invalidate_complete_page(struct address_
{
int ret;
- if (page->mapping != mapping)
+ if (!is_page_consistent(page, mapping))
return 0;
if (PagePrivate(page) && !try_to_release_page(page, 0))
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(invalidate_mapping_pages);
static int
invalidate_complete_page2(struct address_space *mapping, struct page *page)
{
- if (page->mapping != mapping)
+ if (!is_page_consistent(page, mapping))
return 0;
if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL))
@@ -369,7 +369,8 @@ static int do_launder_page(struct addres
{
if (!PageDirty(page))
return 0;
- if (page->mapping != mapping || mapping->a_ops->launder_page == NULL)
+ if (!is_page_consistent(page, mapping) ||
+ mapping->a_ops->launder_page == NULL)
return 0;
return mapping->a_ops->launder_page(page);
}
@@ -405,7 +406,7 @@ int invalidate_inode_pages2_range(struct
pgoff_t page_index;
lock_page(page);
- if (page->mapping != mapping) {
+ if (!is_page_consistent(page, mapping)) {
unlock_page(page);
continue;
}
-
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