Page cache: Replace PAGE_CACHE_xx with inline functions

index 8a83537..836e9dd 100644
@@ -52,12 +52,66 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask)
  * space in smaller chunks for same flexibility).
  *
  * Or rather, it _will_ be done in larger chunks.
+ *
+ * The following constants can be used if a filesystem only supports a single
+ * page size.
  */
 #define PAGE_CACHE_SHIFT	PAGE_SHIFT
 #define PAGE_CACHE_SIZE		PAGE_SIZE
 #define PAGE_CACHE_MASK		PAGE_MASK
 #define PAGE_CACHE_ALIGN(addr)	(((addr)+PAGE_CACHE_SIZE-1)&PAGE_CACHE_MASK)
 
+/*
+ * Functions that are currently setup for a fixed PAGE_SIZEd. The use of
+ * these will allow a variable page size pagecache in the future.
+ */
+static inline int mapping_order(struct address_space *a)
+{
+	return 0;
+}
+
+static inline int page_cache_shift(struct address_space *a)
+{
+	return PAGE_SHIFT;
+}
+
+static inline unsigned int page_cache_size(struct address_space *a)
+{
+	return PAGE_SIZE;
+}
+
+static inline loff_t page_cache_mask(struct address_space *a)
+{
+	return (loff_t)PAGE_MASK;
+}
+
+static inline unsigned int page_cache_offset(struct address_space *a,
+		loff_t pos)
+{
+	return pos & ~PAGE_MASK;
+}
+
+static inline pgoff_t page_cache_index(struct address_space *a,
+		loff_t pos)
+{
+	return pos >> page_cache_shift(a);
+}
+
+/*
+ * Index of the page starting on or after the given position.
+ */
+static inline pgoff_t page_cache_next(struct address_space *a,
+		loff_t pos)
+{
+	return page_cache_index(a, pos + page_cache_size(a) - 1);
+}
+
+static inline loff_t page_cache_pos(struct address_space *a,
+		pgoff_t index, unsigned long offset)
+{
+	return ((loff_t)index << page_cache_shift(a)) + offset;
+}
+
 #define page_cache_get(page)		get_page(page)
 #define page_cache_release(page)	put_page(page)
 void release_pages(struct page **pages, int nr, int cold);

Index: mm/mm/filemap.c
===================================================================
@@ -314,8 +314,8 @@ EXPORT_SYMBOL(add_to_page_cache_lru);
 int sync_page_range(struct inode *inode, struct address_space *mapping,
 			loff_t pos, loff_t count)
 {
-	pgoff_t start = pos >> PAGE_CACHE_SHIFT;
-	pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
+	pgoff_t start = page_cache_index(mapping, pos);
+	pgoff_t end = page_cache_index(mapping, pos + count - 1);
 	int ret;
 
 	if (!mapping_cap_writeback_dirty(mapping) || !count)

@@ -346,8 +346,8 @@ EXPORT_SYMBOL(sync_page_range);
 int sync_page_range_nolock(struct inode *inode, struct address_space *mapping,
 			   loff_t pos, loff_t count)
 {
-	pgoff_t start = pos >> PAGE_CACHE_SHIFT;
-	pgoff_t end = (pos + count - 1) >> PAGE_CACHE_SHIFT;
+	pgoff_t start = page_cache_index(mapping, pos);
+	pgoff_t end = page_cache_index(mapping, pos + count - 1);
 	int ret;
 
 	if (!mapping_cap_writeback_dirty(mapping) || !count)

@@ -376,7 +376,7 @@ int filemap_fdatawait(struct address_spa
 		return 0;
 
 	return wait_on_page_writeback_range(mapping, 0,
-				(i_size - 1) >> PAGE_CACHE_SHIFT);
+				page_cache_index(mapping, i_size - 1));
 }
 EXPORT_SYMBOL(filemap_fdatawait);
 

@@ -424,8 +424,8 @@ int filemap_write_and_wait_range(struct 
 		/* See comment of filemap_write_and_wait() */
 		if (err != -EIO) {
 			int err2 = wait_on_page_writeback_range(mapping,
-						lstart >> PAGE_CACHE_SHIFT,
-						lend >> PAGE_CACHE_SHIFT);
+					page_cache_index(mapping, lstart),
+					page_cache_index(mapping, lend));
 			if (!err)
 				err = err2;
 		}

@@ -897,11 +897,11 @@ void do_generic_mapping_read(struct addr
 	unsigned int prev_offset;
 	int error;
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	prev_index = ra->prev_pos >> PAGE_CACHE_SHIFT;
-	prev_offset = ra->prev_pos & (PAGE_CACHE_SIZE-1);
-	last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
-	offset = *ppos & ~PAGE_CACHE_MASK;
+	index = page_cache_index(mapping, *ppos);
+	prev_index = page_cache_index(mapping, ra->prev_pos);
+	prev_offset = page_cache_offset(mapping, ra->prev_pos);
+	last_index = page_cache_next(mapping, *ppos + desc->count);
+	offset = page_cache_offset(mapping, *ppos);
 
 	for (;;) {
 		struct page *page;

@@ -938,16 +938,16 @@ page_ok:
 		 */
 
 		isize = i_size_read(inode);
-		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+		end_index = page_cache_index(mapping, isize - 1);
 		if (unlikely(!isize || index > end_index)) {
 			page_cache_release(page);
 			goto out;
 		}
 
 		/* nr is the maximum number of bytes to copy from this page */
-		nr = PAGE_CACHE_SIZE;
+		nr = page_cache_size(mapping);
 		if (index == end_index) {
-			nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+			nr = page_cache_offset(mapping, isize - 1) + 1;
 			if (nr <= offset) {
 				page_cache_release(page);
 				goto out;

@@ -982,8 +982,8 @@ page_ok:
 		 */
 		ret = actor(desc, page, offset, nr);
 		offset += ret;
-		index += offset >> PAGE_CACHE_SHIFT;
-		offset &= ~PAGE_CACHE_MASK;
+		index += page_cache_index(mapping, offset);
+		offset = page_cache_offset(mapping, offset);
 		prev_offset = offset;
 
 		page_cache_release(page);

@@ -1073,11 +1073,8 @@ no_cached_page:
 	}
 
 out:
-	ra->prev_pos = prev_index;
-	ra->prev_pos <<= PAGE_CACHE_SHIFT;
-	ra->prev_pos |= prev_offset;
-
-	*ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset;
+	ra->prev_pos = page_cache_pos(mapping, prev_index, prev_offset);
+	*ppos = page_cache_pos(mapping, index, offset);
 	if (filp)
 		file_accessed(filp);
 }

@@ -1257,8 +1254,8 @@ asmlinkage ssize_t sys_readahead(int fd,
 	if (file) {
 		if (file->f_mode & FMODE_READ) {
 			struct address_space *mapping = file->f_mapping;
-			pgoff_t start = offset >> PAGE_CACHE_SHIFT;
-			pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
+			pgoff_t start = page_cache_index(mapping, offset);
+			pgoff_t end = page_cache_index(mapping, offset + count - 1);
 			unsigned long len = end - start + 1;
 			ret = do_readahead(mapping, file, start, len);
 		}

@@ -1326,7 +1323,7 @@ int filemap_fault(struct vm_area_struct 
 	int did_readaround = 0;
 	int ret = 0;
 
-	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	size = page_cache_next(mapping, i_size_read(inode));
 	if (vmf->pgoff >= size)
 		return VM_FAULT_SIGBUS;
 

@@ -1401,7 +1398,7 @@ retry_find:
 		goto page_not_uptodate;
 
 	/* Must recheck i_size under page lock */
-	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	size = page_cache_next(mapping, i_size_read(inode));
 	if (unlikely(vmf->pgoff >= size)) {
 		unlock_page(page);
 		page_cache_release(page);

@@ -1412,7 +1409,7 @@ retry_find:
 	 * Found the page and have a reference on it.
 	 */
 	mark_page_accessed(page);
-	ra->prev_pos = (loff_t)page->index << PAGE_CACHE_SHIFT;
+	ra->prev_pos = page_cache_pos(mapping, page->index, 0);
 	vmf->page = page;
 	return ret | VM_FAULT_LOCKED;
 

@@ -1896,8 +1893,8 @@ int pagecache_write_begin(struct file *f
 							pagep, fsdata);
 	} else {
 		int ret;
-		pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-		unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+		pgoff_t index = page_cache_index(mapping, pos);
+		unsigned offset = page_cache_offset(mapping, pos);
 		struct inode *inode = mapping->host;
 		struct page *page;
 again:

@@ -1948,7 +1945,7 @@ int pagecache_write_end(struct file *fil
 		ret = aops->write_end(file, mapping, pos, len, copied,
 							page, fsdata);
 	} else {
-		unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
+		unsigned offset = page_cache_offset(mapping, pos);
 		struct inode *inode = mapping->host;
 
 		flush_dcache_page(page);

@@ -2053,10 +2050,11 @@ static ssize_t generic_perform_write_2co
 		unsigned long bytes;	/* Bytes to write to page */
 		size_t copied;		/* Bytes copied from user */
 
-		offset = (pos & (PAGE_CACHE_SIZE - 1));
-		index = pos >> PAGE_CACHE_SHIFT;
-		bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
-						iov_iter_count(i));
+		offset = page_cache_offset(mapping, pos);
+		index = page_cache_index(mapping, pos);
+		bytes = min_t(unsigned long,
+				page_cache_size(mapping) - offset,
+				iov_iter_count(i));
 
 		/*
 		 * a non-NULL src_page indicates that we're doing the

@@ -2227,10 +2225,11 @@ static ssize_t generic_perform_write(str
 		size_t copied;		/* Bytes copied from user */
 		void *fsdata;
 
-		offset = (pos & (PAGE_CACHE_SIZE - 1));
-		index = pos >> PAGE_CACHE_SHIFT;
-		bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
-						iov_iter_count(i));
+		offset = page_cache_offset(mapping, pos);
+		index = page_cache_index(mapping, pos);
+		bytes = min_t(unsigned long,
+				page_cache_size(mapping) - offset,
+				iov_iter_count(i));
 
 again:
 

@@ -2276,8 +2275,9 @@ again:
 			 * because not all segments in the iov can be copied at
 			 * once without a pagefault.
 			 */
-			bytes = min_t(unsigned long, PAGE_CACHE_SIZE - offset,
-						iov_iter_single_seg_count(i));
+			bytes = min_t(unsigned long,
+					page_cache_size(mapping) - offset,
+					iov_iter_single_seg_count(i));
 			goto again;
 		}
 		iov_iter_advance(i, copied);

@@ -2419,8 +2419,8 @@ __generic_file_aio_write_nolock(struct k
 		if (err == 0) {
 			written = written_buffered;
 			invalidate_mapping_pages(mapping,
-						 pos >> PAGE_CACHE_SHIFT,
-						 endbyte >> PAGE_CACHE_SHIFT);
+						 page_cache_index(mapping, pos),
+						 page_cache_index(mapping, endbyte));
 		} else {
 			/*
 			 * We don't know how much we wrote, so just return

@@ -2507,7 +2507,7 @@ generic_file_direct_IO(int rw, struct ki
 	 */
 	if (rw == WRITE) {
 		write_len = iov_length(iov, nr_segs);
-		end = (offset + write_len - 1) >> PAGE_CACHE_SHIFT;
+		end = page_cache_index(mapping, offset + write_len - 1);
 	       	if (mapping_mapped(mapping))
 			unmap_mapping_range(mapping, offset, write_len, 0);
 	}

@@ -2524,7 +2524,7 @@ generic_file_direct_IO(int rw, struct ki
 	 */
 	if (rw == WRITE && mapping->nrpages) {
 		retval = invalidate_inode_pages2_range(mapping,
-					offset >> PAGE_CACHE_SHIFT, end);
+					page_cache_index(mapping, offset), end);
 		if (retval)
 			goto out;
 	}

@@ -2540,7 +2540,8 @@ generic_file_direct_IO(int rw, struct ki
 	 * fails, tough, the write still worked...
 	 */
 	if (rw == WRITE && mapping->nrpages) {
-		invalidate_inode_pages2_range(mapping, offset >> PAGE_CACHE_SHIFT, end);
+		invalidate_inode_pages2_range(mapping,
+				page_cache_index(mapping, offset), end);
 	}
 out:
 	return retval;

Index: mm/mm/page-writeback.c
===================================================================
@@ -818,8 +818,8 @@ int write_cache_pages(struct address_spa
 		index = mapping->writeback_index; /* Start from prev offset */
 		end = -1;
 	} else {
-		index = wbc->range_start >> PAGE_CACHE_SHIFT;
-		end = wbc->range_end >> PAGE_CACHE_SHIFT;
+		index = page_cache_index(mapping, wbc->range_start);
+		end = page_cache_index(mapping, wbc->range_end);
 		if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
 			range_whole = 1;
 		scanned = 1;

@@ -1025,7 +1025,7 @@ int __set_page_dirty_nobuffers(struct pa
 				__inc_zone_page_state(page, NR_FILE_DIRTY);
 				__inc_bdi_stat(mapping->backing_dev_info,
 						BDI_RECLAIMABLE);
-				task_io_account_write(PAGE_CACHE_SIZE);
+				task_io_account_write(page_cache_size(mapping));
 			}
 			radix_tree_tag_set(&mapping->page_tree,
 				page_index(page), PAGECACHE_TAG_DIRTY);

Index: mm/mm/truncate.c
===================================================================
@@ -46,9 +46,10 @@ void do_invalidatepage(struct page *page
 		(*invalidatepage)(page, offset);
 }
 
-static inline void truncate_partial_page(struct page *page, unsigned partial)
+static inline void truncate_partial_page(struct address_space *mapping,
+			struct page *page, unsigned partial)
 {
-	zero_user_segment(page, partial, PAGE_CACHE_SIZE);
+	zero_user_segment(page, partial, page_cache_size(mapping));
 	if (PagePrivate(page))
 		do_invalidatepage(page, partial);
 }

@@ -98,7 +99,7 @@ truncate_complete_page(struct address_sp
 	if (page->mapping != mapping)
 		return;
 
-	cancel_dirty_page(page, PAGE_CACHE_SIZE);
+	cancel_dirty_page(page, page_cache_size(mapping));
 
 	if (PagePrivate(page))
 		do_invalidatepage(page, 0);

@@ -160,9 +161,9 @@ invalidate_complete_page(struct address_
 void truncate_inode_pages_range(struct address_space *mapping,
 				loff_t lstart, loff_t lend)
 {
-	const pgoff_t start = (lstart + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
+	const pgoff_t start = page_cache_next(mapping, lstart);
 	pgoff_t end;
-	const unsigned partial = lstart & (PAGE_CACHE_SIZE - 1);
+	const unsigned partial = page_cache_offset(mapping, lstart);
 	struct pagevec pvec;
 	pgoff_t next;
 	int i;

@@ -170,8 +171,9 @@ void truncate_inode_pages_range(struct a
 	if (mapping->nrpages == 0)
 		return;
 
-	BUG_ON((lend & (PAGE_CACHE_SIZE - 1)) != (PAGE_CACHE_SIZE - 1));
-	end = (lend >> PAGE_CACHE_SHIFT);
+	BUG_ON(page_cache_offset(mapping, lend) !=
+				page_cache_size(mapping) - 1);
+	end = page_cache_index(mapping, lend);
 
 	pagevec_init(&pvec, 0);
 	next = start;

@@ -197,8 +199,8 @@ void truncate_inode_pages_range(struct a
 			}
 			if (page_mapped(page)) {
 				unmap_mapping_range(mapping,
-				  (loff_t)page_index<<PAGE_CACHE_SHIFT,
-				  PAGE_CACHE_SIZE, 0);
+				  page_cache_pos(mapping, page_index, 0),
+				  page_cache_size(mapping), 0);
 			}
 			truncate_complete_page(mapping, page);
 			unlock_page(page);

@@ -211,7 +213,7 @@ void truncate_inode_pages_range(struct a
 		struct page *page = find_lock_page(mapping, start - 1);
 		if (page) {
 			wait_on_page_writeback(page);
-			truncate_partial_page(page, partial);
+			truncate_partial_page(mapping, page, partial);
 			unlock_page(page);
 			page_cache_release(page);
 		}

@@ -239,8 +241,8 @@ void truncate_inode_pages_range(struct a
 			wait_on_page_writeback(page);
 			if (page_mapped(page)) {
 				unmap_mapping_range(mapping,
-				  (loff_t)page->index<<PAGE_CACHE_SHIFT,
-				  PAGE_CACHE_SIZE, 0);
+				  page_cache_pos(mapping, page->index, 0),
+				  page_cache_size(mapping), 0);
 			}
 			if (page->index > next)
 				next = page->index;

@@ -424,9 +426,8 @@ int invalidate_inode_pages2_range(struct
 					 * Zap the rest of the file in one hit.
 					 */
 					unmap_mapping_range(mapping,
-					   (loff_t)page_index<<PAGE_CACHE_SHIFT,
-					   (loff_t)(end - page_index + 1)
-							<< PAGE_CACHE_SHIFT,
+					   page_cache_pos(mapping, page_index, 0),
+					   page_cache_pos(mapping, end - page_index + 1, 0),
 					    0);
 					did_range_unmap = 1;
 				} else {

@@ -434,8 +435,8 @@ int invalidate_inode_pages2_range(struct
 					 * Just zap this page
 					 */
 					unmap_mapping_range(mapping,
-					  (loff_t)page_index<<PAGE_CACHE_SHIFT,
-					  PAGE_CACHE_SIZE, 0);
+					  page_cache_pos(mapping, page_index, 0),
+					  page_cache_size(mapping), 0);
 				}
 			}
 			BUG_ON(page_mapped(page));

Index: mm/mm/rmap.c
===================================================================
@@ -190,9 +190,14 @@ static void page_unlock_anon_vma(struct 
 static inline unsigned long
 vma_address(struct page *page, struct vm_area_struct *vma)
 {
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff;
 	unsigned long address;
 
+	if (PageAnon(page))
+		pgoff = page->index;
+	else
+		pgoff = page->index << mapping_order(page->mapping);
+
 	address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
 	if (unlikely(address < vma->vm_start || address >= vma->vm_end)) {
 		/* page should be within @vma mapping range */

@@ -345,7 +350,7 @@ static int page_referenced_file(struct p
 {
 	unsigned int mapcount;
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int referenced = 0;

@@ -464,7 +469,7 @@ out:
 
 static int page_mkclean_file(struct address_space *mapping, struct page *page)
 {
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int ret = 0;

@@ -897,7 +902,7 @@ 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;
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int ret = SWAP_AGAIN;

Index: mm/mm/rmap.c
===================================================================
@@ -350,7 +350,7 @@ static int page_referenced_file(struct p
 {
 	unsigned int mapcount;
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << mapping_order(mapping);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int referenced = 0;

Index: mm/mm/rmap.c
===================================================================
@@ -350,7 +350,7 @@ static int page_referenced_file(struct p
 {
 	unsigned int mapcount;
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << mapping_order(mapping);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int referenced = 0;

@@ -469,7 +469,7 @@ out:
 
 static int page_mkclean_file(struct address_space *mapping, struct page *page)
 {
-	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << mapping_order(mapping);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int ret = 0;

@@ -902,7 +902,7 @@ 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;
-	pgoff_t pgoff = page->index << (page_cache_shift(mapping) - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << mapping_order(mapping);
 	struct vm_area_struct *vma;
 	struct prio_tree_iter iter;
 	int ret = SWAP_AGAIN;

Index: mm/mm/filemap_xip.c
===================================================================
@@ -60,24 +60,24 @@ do_xip_mapping_read(struct address_space
 
 	BUG_ON(!mapping->a_ops->get_xip_page);
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	offset = *ppos & ~PAGE_CACHE_MASK;
+	index = page_cache_index(mapping, *ppos);
+	offset = page_cache_offset(mapping, *ppos);
 
 	isize = i_size_read(inode);
 	if (!isize)
 		goto out;
 
-	end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+	end_index = page_cache_index(mapping, isize - 1);
 	for (;;) {
 		struct page *page;
 		unsigned long nr, ret;
 
 		/* nr is the maximum number of bytes to copy from this page */
-		nr = PAGE_CACHE_SIZE;
+		nr = page_cache_size(mapping);
 		if (index >= end_index) {
 			if (index > end_index)
 				goto out;
-			nr = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+			nr = page_cache_next(mapping, size - 1) + 1;
 			if (nr <= offset) {
 				goto out;
 			}

@@ -116,8 +116,8 @@ do_xip_mapping_read(struct address_space
 		 */
 		ret = actor(desc, page, offset, nr);
 		offset += ret;
-		index += offset >> PAGE_CACHE_SHIFT;
-		offset &= ~PAGE_CACHE_MASK;
+		index += page_cache_index(mapping, offset);
+		offset = page_cache_offset(mapping, offset);
 
 		if (ret == nr && desc->count)
 			continue;

@@ -130,7 +130,7 @@ no_xip_page:
 	}
 
 out:
-	*ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+	*ppos = page_cache_pos(mapping, index, offset);
 	if (filp)
 		file_accessed(filp);
 }

@@ -219,7 +219,7 @@ static int xip_file_fault(struct vm_area
 
 	/* XXX: are VM_FAULT_ codes OK? */
 
-	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	size = page_cache_next(mapping, i_size_read(inode));
 	if (vmf->pgoff >= size)
 		return VM_FAULT_SIGBUS;
 

@@ -289,9 +289,9 @@ __xip_file_write(struct file *filp, cons
 		size_t copied;
 		char *kaddr;
 
-		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
-		index = pos >> PAGE_CACHE_SHIFT;
-		bytes = PAGE_CACHE_SIZE - offset;
+		offset = page_cache_offset(mapping, pos); /* Within page */
+		index = page_cache_index(mapping, pos);
+		bytes = page_cache_size(mapping) - offset;
 		if (bytes > count)
 			bytes = count;
 

@@ -402,8 +402,8 @@ EXPORT_SYMBOL_GPL(xip_file_write);
 int
 xip_truncate_page(struct address_space *mapping, loff_t from)
 {
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	pgoff_t index = page_cache_index(mapping, from);
+	unsigned offset = page_cache_offset(mapping, from);
 	unsigned blocksize;
 	unsigned length;
 	struct page *page;

Index: mm/mm/migrate.c
===================================================================
@@ -197,7 +197,7 @@ static void remove_file_migration_ptes(s
 	struct vm_area_struct *vma;
 	struct address_space *mapping = page_mapping(new);
 	struct prio_tree_iter iter;
-	pgoff_t pgoff = new->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = new->index << mapping_order(mapping);
 
 	if (!mapping)
 		return;

Index: mm/fs/libfs.c
===================================================================
@@ -17,7 +17,8 @@ int simple_getattr(struct vfsmount *mnt,
 {
 	struct inode *inode = dentry->d_inode;
 	generic_fillattr(inode, stat);
-	stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9);
+	stat->blocks = inode->i_mapping->nrpages <<
+				(page_cache_shift(inode->i_mapping) - 9);
 	return 0;
 }
 

@@ -341,10 +342,10 @@ int simple_prepare_write(struct file *fi
 			unsigned from, unsigned to)
 {
 	if (!PageUptodate(page)) {
-		if (to - from != PAGE_CACHE_SIZE)
+		if (to - from != page_cache_size(file->f_mapping))
 			zero_user_segments(page,
 				0, from,
-				to, PAGE_CACHE_SIZE);
+				to, page_cache_size(file->f_mapping));
 	}
 	return 0;
 }

@@ -372,8 +373,9 @@ int simple_write_begin(struct file *file
 static int simple_commit_write(struct file *file, struct page *page,
 			       unsigned from, unsigned to)
 {
-	struct inode *inode = page->mapping->host;
-	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+	loff_t pos = page_cache_pos(mapping, page->index, to);
 
 	if (!PageUptodate(page))
 		SetPageUptodate(page);

Index: mm/fs/sync.c
===================================================================
@@ -260,8 +260,8 @@ int do_sync_mapping_range(struct address
 	ret = 0;
 	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
 		ret = wait_on_page_writeback_range(mapping,
-					offset >> PAGE_CACHE_SHIFT,
-					endbyte >> PAGE_CACHE_SHIFT);
+					page_cache_index(mapping, offset),
+					page_cache_index(mapping, endbyte));
 		if (ret < 0)
 			goto out;
 	}

@@ -275,8 +275,8 @@ int do_sync_mapping_range(struct address
 
 	if (flags & SYNC_FILE_RANGE_WAIT_AFTER) {
 		ret = wait_on_page_writeback_range(mapping,
-					offset >> PAGE_CACHE_SHIFT,
-					endbyte >> PAGE_CACHE_SHIFT);
+					page_cache_index(mapping, offset),
+					page_cache_index(mapping, endbyte));
 	}
 out:
 	return ret;

Index: mm/fs/buffer.c
===================================================================
@@ -278,7 +278,7 @@ __find_get_block_slow(struct block_devic
 	struct page *page;
 	int all_mapped = 1;
 
-	index = block >> (PAGE_CACHE_SHIFT - bd_inode->i_blkbits);
+	index = block >> (page_cache_shift(bd_mapping) - bd_inode->i_blkbits);
 	page = find_get_page(bd_mapping, index);
 	if (!page)
 		goto out;

@@ -720,7 +720,7 @@ static int __set_page_dirty(struct page 
 			__inc_zone_page_state(page, NR_FILE_DIRTY);
 			__inc_bdi_stat(mapping->backing_dev_info,
 					BDI_RECLAIMABLE);
-			task_io_account_write(PAGE_CACHE_SIZE);
+			task_io_account_write(page_cache_size(mapping));
 		}
 		radix_tree_tag_set(&mapping->page_tree,
 				page_index(page), PAGECACHE_TAG_DIRTY);

@@ -914,10 +914,11 @@ struct buffer_head *alloc_page_buffers(s
 {
 	struct buffer_head *bh, *head;
 	long offset;
+	unsigned int page_size = page_cache_size(page->mapping);
 
 try_again:
 	head = NULL;
-	offset = PAGE_SIZE;
+	offset = page_size;
 	while ((offset -= size) >= 0) {
 		bh = alloc_buffer_head(GFP_NOFS);
 		if (!bh)

@@ -1640,6 +1641,7 @@ static int __block_write_full_page(struc
 	struct buffer_head *bh, *head;
 	const unsigned blocksize = 1 << inode->i_blkbits;
 	int nr_underway = 0;
+	struct address_space *mapping = inode->i_mapping;
 
 	BUG_ON(!PageLocked(page));
 

@@ -1660,7 +1662,8 @@ static int __block_write_full_page(struc
 	 * handle that here by just cleaning them.
 	 */
 
-	block = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	block = (sector_t)page->index <<
+		(page_cache_shift(mapping) - inode->i_blkbits);
 	head = page_buffers(page);
 	bh = head;
 

@@ -1777,7 +1780,7 @@ recover:
 	} while ((bh = bh->b_this_page) != head);
 	SetPageError(page);
 	BUG_ON(PageWriteback(page));
-	mapping_set_error(page->mapping, err);
+	mapping_set_error(mapping, err);
 	set_page_writeback(page);
 	do {
 		struct buffer_head *next = bh->b_this_page;

@@ -1844,8 +1847,8 @@ static int __block_prepare_write(struct 
 	struct buffer_head *bh, *head, *wait[2], **wait_bh=wait;
 
 	BUG_ON(!PageLocked(page));
-	BUG_ON(from > PAGE_CACHE_SIZE);
-	BUG_ON(to > PAGE_CACHE_SIZE);
+	BUG_ON(from > page_cache_size(inode->i_mapping));
+	BUG_ON(to > page_cache_size(inode->i_mapping));
 	BUG_ON(from > to);
 
 	blocksize = 1 << inode->i_blkbits;

@@ -1854,7 +1857,8 @@ static int __block_prepare_write(struct 
 	head = page_buffers(page);
 
 	bbits = inode->i_blkbits;
-	block = (sector_t)page->index << (PAGE_CACHE_SHIFT - bbits);
+	block = (sector_t)page->index <<
+		(page_cache_shift(inode->i_mapping) - bbits);
 
 	for(bh = head, block_start = 0; bh != head || !block_start;
 	    block++, block_start=block_end, bh = bh->b_this_page) {

@@ -1969,8 +1973,8 @@ int block_write_begin(struct file *file,
 	unsigned start, end;
 	int ownpage = 0;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	start = pos & (PAGE_CACHE_SIZE - 1);
+	index = page_cache_index(mapping, pos);
+	start = page_cache_offset(mapping, pos);
 	end = start + len;
 
 	page = *pagep;

@@ -2017,7 +2021,7 @@ int block_write_end(struct file *file, s
 	struct inode *inode = mapping->host;
 	unsigned start;
 
-	start = pos & (PAGE_CACHE_SIZE - 1);
+	start = page_cache_offset(mapping, pos);
 
 	if (unlikely(copied < len)) {
 		/*

@@ -2095,7 +2099,8 @@ int block_read_full_page(struct page *pa
 		create_empty_buffers(page, blocksize, 0);
 	head = page_buffers(page);
 
-	iblock = (sector_t)page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	iblock = (sector_t)page->index <<
+		(page_cache_shift(page->mapping) - inode->i_blkbits);
 	lblock = (i_size_read(inode)+blocksize-1) >> inode->i_blkbits;
 	bh = head;
 	nr = 0;

@@ -2213,16 +2218,16 @@ int cont_expand_zero(struct file *file, 
 	unsigned zerofrom, offset, len;
 	int err = 0;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	offset = pos & ~PAGE_CACHE_MASK;
+	index = page_cache_index(mapping, pos);
+	offset = page_cache_offset(mapping, pos);
 
-	while (index > (curidx = (curpos = *bytes)>>PAGE_CACHE_SHIFT)) {
-		zerofrom = curpos & ~PAGE_CACHE_MASK;
+	while (index > (curidx = page_cache_index(mapping, (curpos = *bytes)))) {
+		zerofrom = page_cache_offset(mapping, curpos);
 		if (zerofrom & (blocksize-1)) {
 			*bytes |= (blocksize-1);
 			(*bytes)++;
 		}
-		len = PAGE_CACHE_SIZE - zerofrom;
+		len = page_cache_size(mapping) - zerofrom;
 
 		err = pagecache_write_begin(file, mapping, curpos, len,
 						AOP_FLAG_UNINTERRUPTIBLE,

@@ -2240,7 +2245,7 @@ int cont_expand_zero(struct file *file, 
 
 	/* page covers the boundary, find the boundary offset */
 	if (index == curidx) {
-		zerofrom = curpos & ~PAGE_CACHE_MASK;
+		zerofrom = page_cache_offset(mapping, curpos);
 		/* if we will expand the thing last block will be filled */
 		if (offset <= zerofrom) {
 			goto out;

@@ -2286,7 +2291,7 @@ int cont_write_begin(struct file *file, 
 	if (err)
 		goto out;
 
-	zerofrom = *bytes & ~PAGE_CACHE_MASK;
+	zerofrom = page_cache_offset(mapping, *bytes);
 	if (pos+len > *bytes && zerofrom & (blocksize-1)) {
 		*bytes |= (blocksize-1);
 		(*bytes)++;

@@ -2319,8 +2324,9 @@ int block_commit_write(struct page *page
 int generic_commit_write(struct file *file, struct page *page,
 		unsigned from, unsigned to)
 {
-	struct inode *inode = page->mapping->host;
-	loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
+	loff_t pos = page_cache_pos(mapping, page->index, to);
 	__block_commit_write(inode,page,from,to);
 	/*
 	 * No need to use i_size_read() here, the i_size

@@ -2356,20 +2362,22 @@ block_page_mkwrite(struct vm_area_struct
 	unsigned long end;
 	loff_t size;
 	int ret = -EINVAL;
+	struct address_space *mapping;
 
 	lock_page(page);
+	mapping = page->mapping;
 	size = i_size_read(inode);
-	if ((page->mapping != inode->i_mapping) ||
+	if ((mapping != inode->i_mapping) ||
 	    (page_offset(page) > size)) {
 		/* page got truncated out from underneath us */
 		goto out_unlock;
 	}
 
 	/* page is wholly or partially inside EOF */
-	if (((page->index + 1) << PAGE_CACHE_SHIFT) > size)
-		end = size & ~PAGE_CACHE_MASK;
+	if (page_cache_pos(mapping, page->index + 1, 0) > size)
+		end = page_cache_offset(mapping, size);
 	else
-		end = PAGE_CACHE_SIZE;
+		end = page_cache_size(mapping);
 
 	ret = block_prepare_write(page, 0, end, get_block);
 	if (!ret)

@@ -2437,8 +2445,8 @@ int nobh_write_begin(struct file *file, 
 	int ret = 0;
 	int is_mapped_to_disk = 1;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	index = page_cache_index(mapping, pos);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 	page = __grab_cache_page(mapping, index);

@@ -2473,7 +2481,8 @@ int nobh_write_begin(struct file *file, 
 		goto out_release;
 	}
 
-	block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
+	block_in_file = (sector_t)page->index <<
+			(page_cache_shift(mapping) - blkbits);
 
 	/*
 	 * We loop across all blocks in the page, whether or not they are

@@ -2481,7 +2490,7 @@ int nobh_write_begin(struct file *file, 
 	 * page is fully mapped-to-disk.
 	 */
 	for (block_start = 0, block_in_page = 0, bh = head;
-		  block_start < PAGE_CACHE_SIZE;
+		  block_start < page_cache_size(mapping);
 		  block_in_page++, block_start += blocksize, bh = bh->b_this_page) {
 		int create;
 

@@ -2607,9 +2616,10 @@ EXPORT_SYMBOL(nobh_write_end);
 int nobh_writepage(struct page *page, get_block_t *get_block,
 			struct writeback_control *wbc)
 {
-	struct inode * const inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode * const inode = mapping->host;
 	loff_t i_size = i_size_read(inode);
-	const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	const pgoff_t end_index = page_cache_offset(mapping, i_size);
 	unsigned offset;
 	int ret;
 

@@ -2618,7 +2628,7 @@ int nobh_writepage(struct page *page, ge
 		goto out;
 
 	/* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
+	offset = page_cache_offset(mapping, i_size);
 	if (page->index >= end_index+1 || !offset) {
 		/*
 		 * The page may have dirty, unmapped buffers.  For example,

@@ -2641,7 +2651,7 @@ int nobh_writepage(struct page *page, ge
 	 * the  page size, the remaining memory is zeroed when mapped, and
 	 * writes to that region are not written out to the file."
 	 */
-	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+	zero_user_segment(page, offset, page_cache_size(mapping));
 out:
 	ret = mpage_writepage(page, get_block, wbc);
 	if (ret == -EAGAIN)

@@ -2653,8 +2663,8 @@ EXPORT_SYMBOL(nobh_writepage);
 int nobh_truncate_page(struct address_space *mapping,
 			loff_t from, get_block_t *get_block)
 {
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	pgoff_t index = page_cache_index(mapping, from);
+	unsigned offset = page_cache_offset(mapping, from);
 	unsigned blocksize;
 	sector_t iblock;
 	unsigned length, pos;

@@ -2671,7 +2681,7 @@ int nobh_truncate_page(struct address_sp
 		return 0;
 
 	length = blocksize - length;
-	iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+	iblock = (sector_t)index << (page_cache_shift(mapping) - inode->i_blkbits);
 
 	page = grab_cache_page(mapping, index);
 	err = -ENOMEM;

@@ -2729,8 +2739,8 @@ EXPORT_SYMBOL(nobh_truncate_page);
 int block_truncate_page(struct address_space *mapping,
 			loff_t from, get_block_t *get_block)
 {
-	pgoff_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	pgoff_t index = page_cache_index(mapping, from);
+	unsigned offset = page_cache_offset(mapping, from);
 	unsigned blocksize;
 	sector_t iblock;
 	unsigned length, pos;

@@ -2747,8 +2757,8 @@ int block_truncate_page(struct address_s
 		return 0;
 
 	length = blocksize - length;
-	iblock = (sector_t)index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
-	
+	iblock = (sector_t)index <<
+			(page_cache_shift(mapping) - inode->i_blkbits);
 	page = grab_cache_page(mapping, index);
 	err = -ENOMEM;
 	if (!page)

@@ -2807,9 +2817,10 @@ out:
 int block_write_full_page(struct page *page, get_block_t *get_block,
 			struct writeback_control *wbc)
 {
-	struct inode * const inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode * const inode = mapping->host;
 	loff_t i_size = i_size_read(inode);
-	const pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+	const pgoff_t end_index = page_cache_index(mapping, i_size);
 	unsigned offset;
 
 	/* Is the page fully inside i_size? */

@@ -2817,7 +2828,7 @@ int block_write_full_page(struct page *p
 		return __block_write_full_page(inode, page, get_block, wbc);
 
 	/* Is the page fully outside i_size? (truncate in progress) */
-	offset = i_size & (PAGE_CACHE_SIZE-1);
+	offset = page_cache_offset(mapping, i_size);
 	if (page->index >= end_index+1 || !offset) {
 		/*
 		 * The page may have dirty, unmapped buffers.  For example,

@@ -2836,7 +2847,7 @@ int block_write_full_page(struct page *p
 	 * the  page size, the remaining memory is zeroed when mapped, and
 	 * writes to that region are not written out to the file."
 	 */
-	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+	zero_user_segment(page, offset, page_cache_size(mapping));
 	return __block_write_full_page(inode, page, get_block, wbc);
 }
 

@@ -3086,7 +3097,7 @@ int try_to_free_buffers(struct page *pag
 	 * dirty bit from being lost.
 	 */
 	if (ret)
-		cancel_dirty_page(page, PAGE_CACHE_SIZE);
+		cancel_dirty_page(page, page_cache_size(mapping));
 	spin_unlock(&mapping->private_lock);
 out:
 	if (buffers_to_free) {

Index: mm/fs/buffer.c
===================================================================
@@ -914,11 +914,10 @@ struct buffer_head *alloc_page_buffers(s
 {
 	struct buffer_head *bh, *head;
 	long offset;
-	unsigned int page_size = page_cache_size(page->mapping);
 
 try_again:
 	head = NULL;
-	offset = page_size;
+	offset = page_cache_size(page->mapping);
 	while ((offset -= size) >= 0) {
 		bh = alloc_buffer_head(GFP_NOFS);
 		if (!bh)

@@ -2221,7 +2220,8 @@ int cont_expand_zero(struct file *file, 
 	index = page_cache_index(mapping, pos);
 	offset = page_cache_offset(mapping, pos);
 
-	while (index > (curidx = page_cache_index(mapping, (curpos = *bytes)))) {
+	while (curpos = *bytes, curidx = page_cache_index(mapping, curpos),
+			index > curidx) {
 		zerofrom = page_cache_offset(mapping, curpos);
 		if (zerofrom & (blocksize-1)) {
 			*bytes |= (blocksize-1);

@@ -2368,7 +2368,7 @@ block_page_mkwrite(struct vm_area_struct
 	mapping = page->mapping;
 	size = i_size_read(inode);
 	if ((mapping != inode->i_mapping) ||
-	    (page_offset(page) > size)) {
+	    (page_cache_pos(mapping, page->index, 0) > size)) {
 		/* page got truncated out from underneath us */
 		goto out_unlock;
 	}

Index: linux-2.6/fs/mpage.c
===================================================================
@@ -125,7 +125,8 @@ mpage_alloc(struct block_device *bdev,
 static void 
 map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block) 
 {
-	struct inode *inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
 	struct buffer_head *page_bh, *head;
 	int block = 0;
 

@@ -134,9 +135,9 @@ map_buffer_to_page(struct page *page, st
 		 * don't make any buffers if there is only one buffer on
 		 * the page and the page just needs to be set up to date
 		 */
-		if (inode->i_blkbits == PAGE_CACHE_SHIFT && 
+		if (inode->i_blkbits == page_cache_shift(mapping) &&
 		    buffer_uptodate(bh)) {
-			SetPageUptodate(page);    
+			SetPageUptodate(page);
 			return;
 		}
 		create_empty_buffers(page, 1 << inode->i_blkbits, 0);

@@ -169,9 +170,10 @@ do_mpage_readpage(struct bio *bio, struc
 		sector_t *last_block_in_bio, struct buffer_head *map_bh,
 		unsigned long *first_logical_block, get_block_t get_block)
 {
-	struct inode *inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
 	const unsigned blkbits = inode->i_blkbits;
-	const unsigned blocks_per_page = PAGE_CACHE_SIZE >> blkbits;
+	const unsigned blocks_per_page = page_cache_size(mapping) >> blkbits;
 	const unsigned blocksize = 1 << blkbits;
 	sector_t block_in_file;
 	sector_t last_block;

@@ -188,7 +190,7 @@ do_mpage_readpage(struct bio *bio, struc
 	if (page_has_buffers(page))
 		goto confused;
 
-	block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
+	block_in_file = (sector_t)page->index << (page_cache_shift(mapping) - blkbits);
 	last_block = block_in_file + nr_pages * blocks_per_page;
 	last_block_in_file = (i_size_read(inode) + blocksize - 1) >> blkbits;
 	if (last_block > last_block_in_file)

@@ -276,7 +278,8 @@ do_mpage_readpage(struct bio *bio, struc
 	}
 
 	if (first_hole != blocks_per_page) {
-		zero_user_segment(page, first_hole << blkbits, PAGE_CACHE_SIZE);
+		zero_user_segment(page, first_hole << blkbits,
+					page_cache_size(mapping));
 		if (first_hole == 0) {
 			SetPageUptodate(page);
 			unlock_page(page);

@@ -454,7 +457,7 @@ static int __mpage_writepage(struct page
 	struct inode *inode = page->mapping->host;
 	const unsigned blkbits = inode->i_blkbits;
 	unsigned long end_index;
-	const unsigned blocks_per_page = PAGE_CACHE_SIZE >> blkbits;
+	const unsigned blocks_per_page = page_cache_size(mapping) >> blkbits;
 	sector_t last_block;
 	sector_t block_in_file;
 	sector_t blocks[MAX_BUF_PER_PAGE];

@@ -523,7 +526,8 @@ static int __mpage_writepage(struct page
 	 * The page has no buffers: map it to disk
 	 */
 	BUG_ON(!PageUptodate(page));
-	block_in_file = (sector_t)page->index << (PAGE_CACHE_SHIFT - blkbits);
+	block_in_file = (sector_t)page->index <<
+			(page_cache_shift(mapping) - blkbits);
 	last_block = (i_size - 1) >> blkbits;
 	map_bh.b_page = page;
 	for (page_block = 0; page_block < blocks_per_page; ) {

@@ -555,7 +559,7 @@ static int __mpage_writepage(struct page
 	first_unmapped = page_block;
 
 page_is_mapped:
-	end_index = i_size >> PAGE_CACHE_SHIFT;
+	end_index = page_cache_index(mapping, i_size);
 	if (page->index >= end_index) {
 		/*
 		 * The page straddles i_size.  It must be zeroed out on each

@@ -565,11 +569,11 @@ page_is_mapped:
 		 * is zeroed when mapped, and writes to that region are not
 		 * written out to the file."
 		 */
-		unsigned offset = i_size & (PAGE_CACHE_SIZE - 1);
+		unsigned offset = page_cache_offset(mapping, i_size);
 
 		if (page->index > end_index || !offset)
 			goto confused;
-		zero_user_segment(page, offset, PAGE_CACHE_SIZE);
+		zero_user_segment(page, offset, page_cache_size(mapping));
 	}
 
 	/*

Index: mm/mm/fadvise.c
===================================================================
@@ -79,8 +79,8 @@ asmlinkage long sys_fadvise64_64(int fd,
 		}
 
 		/* First and last PARTIAL page! */
-		start_index = offset >> PAGE_CACHE_SHIFT;
-		end_index = endbyte >> PAGE_CACHE_SHIFT;
+		start_index = page_cache_index(mapping, offset);
+		end_index = page_cache_index(mapping, endbyte);
 
 		/* Careful about overflow on the "+1" */
 		nrpages = end_index - start_index + 1;

@@ -100,8 +100,8 @@ asmlinkage long sys_fadvise64_64(int fd,
 			filemap_flush(mapping);
 
 		/* First and last FULL page! */
-		start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
-		end_index = (endbyte >> PAGE_CACHE_SHIFT);
+		start_index = page_cache_next(mapping, offset);
+		end_index = page_cache_index(mapping, endbyte);
 
 		if (end_index >= start_index)
 			invalidate_mapping_pages(mapping, start_index,

Index: mm/fs/splice.c
===================================================================
@@ -285,9 +285,9 @@ __generic_file_splice_read(struct file *
 		.spd_release = spd_release_page,
 	};
 
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	loff = *ppos & ~PAGE_CACHE_MASK;
-	req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+	index = page_cache_index(mapping, *ppos);
+	loff = page_cache_offset(mapping, *ppos);
+	req_pages = page_cache_next(mapping, len + loff);
 	nr_pages = min(req_pages, (unsigned)PIPE_BUFFERS);
 
 	/*

@@ -342,7 +342,7 @@ __generic_file_splice_read(struct file *
 	 * Now loop over the map and see if we need to start IO on any
 	 * pages, fill in the partial map, etc.
 	 */
-	index = *ppos >> PAGE_CACHE_SHIFT;
+	index = page_cache_index(mapping, *ppos);
 	nr_pages = spd.nr_pages;
 	spd.nr_pages = 0;
 	for (page_nr = 0; page_nr < nr_pages; page_nr++) {

@@ -354,7 +354,8 @@ __generic_file_splice_read(struct file *
 		/*
 		 * this_len is the max we'll use from this page
 		 */
-		this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
+		this_len = min_t(unsigned long, len,
+					page_cache_size(mapping) - loff);
 		page = pages[page_nr];
 
 		if (PageReadahead(page))

@@ -414,7 +415,7 @@ fill_it:
 		 * i_size must be checked after PageUptodate.
 		 */
 		isize = i_size_read(mapping->host);
-		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
+		end_index = page_cache_index(mapping, isize - 1);
 		if (unlikely(!isize || index > end_index))
 			break;
 

@@ -428,7 +429,7 @@ fill_it:
 			/*
 			 * max good bytes in this page
 			 */
-			plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
+			plen = page_cache_offset(mapping, isize - 1) + 1;
 			if (plen <= loff)
 				break;
 

@@ -453,7 +454,7 @@ fill_it:
 	 */
 	while (page_nr < nr_pages)
 		page_cache_release(pages[page_nr++]);
-	in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
+	in->f_ra.prev_pos = page_cache_index(mapping, index);
 
 	if (spd.nr_pages)
 		return splice_to_pipe(pipe, &spd);

@@ -579,11 +580,11 @@ static int pipe_to_file(struct pipe_inod
 	if (unlikely(ret))
 		return ret;
 
-	offset = sd->pos & ~PAGE_CACHE_MASK;
+	offset = page_cache_offset(mapping, sd->pos);
 
 	this_len = sd->len;
-	if (this_len + offset > PAGE_CACHE_SIZE)
-		this_len = PAGE_CACHE_SIZE - offset;
+	if (this_len + offset > page_cache_size(mapping))
+		this_len = page_cache_size(mapping) - offset;
 
 	ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
 				AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);

@@ -790,7 +791,7 @@ generic_file_splice_write_nolock(struct 
 		unsigned long nr_pages;
 
 		*ppos += ret;
-		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+		nr_pages = page_cache_next(mapping, ret);
 
 		/*
 		 * If file or inode is SYNC and we actually wrote some data,

@@ -852,7 +853,7 @@ generic_file_splice_write(struct pipe_in
 		unsigned long nr_pages;
 
 		*ppos += ret;
-		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+		nr_pages = page_cache_next(mapping, ret);
 
 		/*
 		 * If file or inode is SYNC and we actually wrote some data,

Index: mm/fs/splice.c
===================================================================
@@ -454,7 +454,7 @@ fill_it:
 	 */
 	while (page_nr < nr_pages)
 		page_cache_release(pages[page_nr++]);
-	in->f_ra.prev_pos = page_cache_index(mapping, index);
+	in->f_ra.prev_pos = page_cache_pos(mapping, index, 0);
 
 	if (spd.nr_pages)
 		return splice_to_pipe(pipe, &spd);

Index: linux-2.6/fs/ext2/dir.c
===================================================================
@@ -63,7 +63,8 @@ static inline void ext2_put_page(struct 
 
 static inline unsigned long dir_pages(struct inode *inode)
 {
-	return (inode->i_size+PAGE_CACHE_SIZE-1)>>PAGE_CACHE_SHIFT;
+	return (inode->i_size+page_cache_size(inode->i_mapping)-1)>>
+			page_cache_shift(inode->i_mapping);
 }
 
 /*

@@ -74,10 +75,11 @@ static unsigned
 ext2_last_byte(struct inode *inode, unsigned long page_nr)
 {
 	unsigned last_byte = inode->i_size;
+	struct address_space *mapping = inode->i_mapping;
 
-	last_byte -= page_nr << PAGE_CACHE_SHIFT;
-	if (last_byte > PAGE_CACHE_SIZE)
-		last_byte = PAGE_CACHE_SIZE;
+	last_byte -= page_nr << page_cache_shift(mapping);
+	if (last_byte > page_cache_size(mapping))
+		last_byte = page_cache_size(mapping);
 	return last_byte;
 }
 

@@ -105,18 +107,19 @@ static int ext2_commit_chunk(struct page
 
 static void ext2_check_page(struct page *page)
 {
-	struct inode *dir = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *dir = mapping->host;
 	struct super_block *sb = dir->i_sb;
 	unsigned chunk_size = ext2_chunk_size(dir);
 	char *kaddr = page_address(page);
 	u32 max_inumber = le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count);
 	unsigned offs, rec_len;
-	unsigned limit = PAGE_CACHE_SIZE;
+	unsigned limit = page_cache_size(mapping);
 	ext2_dirent *p;
 	char *error;
 
-	if ((dir->i_size >> PAGE_CACHE_SHIFT) == page->index) {
-		limit = dir->i_size & ~PAGE_CACHE_MASK;
+	if (page_cache_index(mapping, dir->i_size) == page->index) {
+		limit = page_cache_offset(mapping, dir->i_size);
 		if (limit & (chunk_size - 1))
 			goto Ebadsize;
 		if (!limit)

@@ -168,7 +171,7 @@ Einumber:
 bad_entry:
 	ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
 		"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
-		dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
+		dir->i_ino, error, page_cache_pos(mapping, page->index, offs),
 		(unsigned long) le32_to_cpu(p->inode),
 		rec_len, p->name_len);
 	goto fail;

@@ -177,7 +180,7 @@ Eend:
 	ext2_error (sb, "ext2_check_page",
 		"entry in directory #%lu spans the page boundary"
 		"offset=%lu, inode=%lu",
-		dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
+		dir->i_ino, page_cache_pos(mapping, page->index, offs),
 		(unsigned long) le32_to_cpu(p->inode));
 fail:
 	SetPageChecked(page);

@@ -276,8 +279,9 @@ ext2_readdir (struct file * filp, void *
 	loff_t pos = filp->f_pos;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 	struct super_block *sb = inode->i_sb;
-	unsigned int offset = pos & ~PAGE_CACHE_MASK;
-	unsigned long n = pos >> PAGE_CACHE_SHIFT;
+	struct address_space *mapping = inode->i_mapping;
+	unsigned int offset = page_cache_offset(mapping, pos);
+	unsigned long n = page_cache_index(mapping, pos);
 	unsigned long npages = dir_pages(inode);
 	unsigned chunk_mask = ~(ext2_chunk_size(inode)-1);
 	unsigned char *types = NULL;

@@ -298,14 +302,14 @@ ext2_readdir (struct file * filp, void *
 			ext2_error(sb, __FUNCTION__,
 				   "bad page in #%lu",
 				   inode->i_ino);
-			filp->f_pos += PAGE_CACHE_SIZE - offset;
+			filp->f_pos += page_cache_size(mapping) - offset;
 			return -EIO;
 		}
 		kaddr = page_address(page);
 		if (unlikely(need_revalidate)) {
 			if (offset) {
 				offset = ext2_validate_entry(kaddr, offset, chunk_mask);
-				filp->f_pos = (n<<PAGE_CACHE_SHIFT) + offset;
+				filp->f_pos = page_cache_pos(mapping, n, offset);
 			}
 			filp->f_version = inode->i_version;
 			need_revalidate = 0;

@@ -328,7 +332,7 @@ ext2_readdir (struct file * filp, void *
 
 				offset = (char *)de - kaddr;
 				over = filldir(dirent, de->name, de->name_len,
-						(n<<PAGE_CACHE_SHIFT) | offset,
+						page_cache_pos(mapping, n, offset),
 						le32_to_cpu(de->inode), d_type);
 				if (over) {
 					ext2_put_page(page);

@@ -354,6 +358,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 			struct dentry *dentry, struct page ** res_page)
 {
 	const char *name = dentry->d_name.name;
+	struct address_space *mapping = dir->i_mapping;
 	int namelen = dentry->d_name.len;
 	unsigned reclen = EXT2_DIR_REC_LEN(namelen);
 	unsigned long start, n;

@@ -395,7 +400,7 @@ struct ext2_dir_entry_2 * ext2_find_entr
 		if (++n >= npages)
 			n = 0;
 		/* next page is past the blocks we've got */
-		if (unlikely(n > (dir->i_blocks >> (PAGE_CACHE_SHIFT - 9)))) {
+		if (unlikely(n > (dir->i_blocks >> (page_cache_shift(mapping) - 9)))) {
 			ext2_error(dir->i_sb, __FUNCTION__,
 				"dir %lu size %lld exceeds block count %llu",
 				dir->i_ino, dir->i_size,

@@ -466,6 +471,7 @@ void ext2_set_link(struct inode *dir, st
 int ext2_add_link (struct dentry *dentry, struct inode *inode)
 {
 	struct inode *dir = dentry->d_parent->d_inode;
+	struct address_space *mapping = inode->i_mapping;
 	const char *name = dentry->d_name.name;
 	int namelen = dentry->d_name.len;
 	unsigned chunk_size = ext2_chunk_size(dir);

@@ -495,7 +501,7 @@ int ext2_add_link (struct dentry *dentry
 		kaddr = page_address(page);
 		dir_end = kaddr + ext2_last_byte(dir, n);
 		de = (ext2_dirent *)kaddr;
-		kaddr += PAGE_CACHE_SIZE - reclen;
+		kaddr += page_cache_size(mapping) - reclen;
 		while ((char *)de <= kaddr) {
 			if ((char *)de == dir_end) {
 				/* We hit i_size */

Index: mm/fs/ext2/dir.c
===================================================================
@@ -63,8 +63,7 @@ static inline void ext2_put_page(struct 
 
 static inline unsigned long dir_pages(struct inode *inode)
 {
-	return (inode->i_size+page_cache_size(inode->i_mapping)-1)>>
-			page_cache_shift(inode->i_mapping);
+	return page_cache_next(inode->i_mapping, inode->i_size);
 }
 
 /*

@@ -74,13 +73,9 @@ static inline unsigned long dir_pages(st
 static unsigned
 ext2_last_byte(struct inode *inode, unsigned long page_nr)
 {
-	unsigned last_byte = inode->i_size;
 	struct address_space *mapping = inode->i_mapping;
 
-	last_byte -= page_nr << page_cache_shift(mapping);
-	if (last_byte > page_cache_size(mapping))
-		last_byte = page_cache_size(mapping);
-	return last_byte;
+	return inode->i_size - page_cache_pos(mapping, page_nr, 0);
 }
 
 static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)

Index: mm/fs/ext2/dir.c
===================================================================
@@ -63,8 +63,7 @@ static inline void ext2_put_page(struct 
 
 static inline unsigned long dir_pages(struct inode *inode)
 {
-	return (inode->i_size+page_cache_size(inode->i_mapping)-1)>>
-			page_cache_shift(inode->i_mapping);
+	return page_cache_next(inode->i_mapping, inode->i_size);
 }
 
 /*

@@ -77,7 +76,7 @@ ext2_last_byte(struct inode *inode, unsi
 	unsigned last_byte = inode->i_size;
 	struct address_space *mapping = inode->i_mapping;
 
-	last_byte -= page_nr << page_cache_shift(mapping);
+	last_byte -= page_cache_pos(mapping, page_nr, 0);
 	if (last_byte > page_cache_size(mapping))
 		last_byte = page_cache_size(mapping);
 	return last_byte;

Index: mm/fs/ext3/dir.c
===================================================================
@@ -133,7 +133,8 @@ static int ext3_readdir(struct file * fi
 						&map_bh, 0, 0);
 		if (err > 0) {
 			pgoff_t index = map_bh.b_blocknr >>
-					(PAGE_CACHE_SHIFT - inode->i_blkbits);
+				(page_cache_shift(inode->i_mapping)
+					- inode->i_blkbits);
 			if (!ra_has_index(&filp->f_ra, index))
 				page_cache_sync_readahead(
 					sb->s_bdev->bd_inode->i_mapping,

Index: mm/fs/ext3/inode.c
===================================================================
@@ -1159,8 +1159,8 @@ static int ext3_write_begin(struct file 
 	pgoff_t index;
 	unsigned from, to;
 
-	index = pos >> PAGE_CACHE_SHIFT;
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	index = page_cache_index(mapping, pos);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 retry:

@@ -1256,7 +1256,7 @@ static int ext3_ordered_write_end(struct
 	unsigned from, to;
 	int ret = 0, ret2;
 
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 	ret = walk_page_buffers(handle, page_buffers(page),

@@ -1326,7 +1326,7 @@ static int ext3_journalled_write_end(str
 	int partial = 0;
 	unsigned from, to;
 
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 	if (copied < len) {

@@ -1489,6 +1489,7 @@ static int ext3_ordered_writepage(struct
 	handle_t *handle = NULL;
 	int ret = 0;
 	int err;
+	int pagesize = page_cache_size(inode->i_mapping);
 
 	J_ASSERT(PageLocked(page));
 

@@ -1511,8 +1512,7 @@ static int ext3_ordered_writepage(struct
 				(1 << BH_Dirty)|(1 << BH_Uptodate));
 	}
 	page_bufs = page_buffers(page);
-	walk_page_buffers(handle, page_bufs, 0,
-			PAGE_CACHE_SIZE, NULL, bget_one);
+	walk_page_buffers(handle, page_bufs, 0, pagesize, NULL, bget_one);
 
 	ret = block_write_full_page(page, ext3_get_block, wbc);
 

@@ -1529,13 +1529,12 @@ static int ext3_ordered_writepage(struct
 	 * and generally junk.
 	 */
 	if (ret == 0) {
-		err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
-					NULL, journal_dirty_data_fn);
+		err = walk_page_buffers(handle, page_bufs, 0, pagesize,
+			NULL, journal_dirty_data_fn);
 		if (!ret)
 			ret = err;
 	}
-	walk_page_buffers(handle, page_bufs, 0,
-			PAGE_CACHE_SIZE, NULL, bput_one);
+	walk_page_buffers(handle, page_bufs, 0, pagesize, NULL, bput_one);
 	err = ext3_journal_stop(handle);
 	if (!ret)
 		ret = err;

@@ -1583,10 +1582,12 @@ out_fail:
 static int ext3_journalled_writepage(struct page *page,
 				struct writeback_control *wbc)
 {
-	struct inode *inode = page->mapping->host;
+	struct address_space *mapping = page->mapping;
+	struct inode *inode = mapping->host;
 	handle_t *handle = NULL;
 	int ret = 0;
 	int err;
+	int pagesize = page_cache_size(inode->i_mapping);
 
 	if (ext3_journal_current_handle())
 		goto no_write;

@@ -1603,17 +1604,16 @@ static int ext3_journalled_writepage(str
 		 * doesn't seem much point in redirtying the page here.
 		 */
 		ClearPageChecked(page);
-		ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
-					ext3_get_block);
+		ret = block_prepare_write(page, 0, pagesize, ext3_get_block);
 		if (ret != 0) {
 			ext3_journal_stop(handle);
 			goto out_unlock;
 		}
 		ret = walk_page_buffers(handle, page_buffers(page), 0,
-			PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+			pagesize, NULL, do_journal_get_write_access);
 
 		err = walk_page_buffers(handle, page_buffers(page), 0,
-				PAGE_CACHE_SIZE, NULL, write_end_fn);
+			pagesize, NULL, write_end_fn);
 		if (ret == 0)
 			ret = err;
 		EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;

@@ -1828,8 +1828,8 @@ void ext3_set_aops(struct inode *inode)
 static int ext3_block_truncate_page(handle_t *handle, struct page *page,
 		struct address_space *mapping, loff_t from)
 {
-	ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	ext3_fsblk_t index = page_cache_index(mapping, from);
+	unsigned offset = page_cache_offset(mapping, from);
 	unsigned blocksize, iblock, length, pos;
 	struct inode *inode = mapping->host;
 	struct buffer_head *bh;

@@ -1837,7 +1837,8 @@ static int ext3_block_truncate_page(hand
 
 	blocksize = inode->i_sb->s_blocksize;
 	length = blocksize - (offset & (blocksize - 1));
-	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+	iblock = index <<
+		(page_cache_shift(mapping) - inode->i_sb->s_blocksize_bits);
 
 	/*
 	 * For "nobh" option,  we can only work if we don't need to

@@ -2316,7 +2317,7 @@ void ext3_truncate(struct inode *inode)
 		page = NULL;
 	} else {
 		page = grab_cache_page(mapping,
-				inode->i_size >> PAGE_CACHE_SHIFT);
+				page_cache_index(mapping, inode->i_size));
 		if (!page)
 			return;
 	}

Index: mm/fs/ext4/dir.c
===================================================================
@@ -132,7 +132,8 @@ static int ext4_readdir(struct file * fi
 		err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0);
 		if (err > 0) {
 			pgoff_t index = map_bh.b_blocknr >>
-					(PAGE_CACHE_SHIFT - inode->i_blkbits);
+				(page_cache_size(inode->i_mapping)
+					- inode->i_blkbits);
 			if (!ra_has_index(&filp->f_ra, index))
 				page_cache_sync_readahead(
 					sb->s_bdev->bd_inode->i_mapping,

Index: mm/fs/ext4/inode.c
===================================================================
@@ -1110,8 +1110,8 @@ static int ext4_write_begin(struct file 
  	pgoff_t index;
  	unsigned from, to;
 
- 	index = pos >> PAGE_CACHE_SHIFT;
- 	from = pos & (PAGE_CACHE_SIZE - 1);
+ 	index = page_cache_index(mapping, pos);
+ 	from = page_cache_offset(mapping, pos);
  	to = from + len;
 
 retry:

@@ -1206,7 +1206,7 @@ static int ext4_ordered_write_end(struct
 	unsigned from, to;
 	int ret = 0, ret2;
 
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 	ret = walk_page_buffers(handle, page_buffers(page),

@@ -1276,7 +1276,7 @@ static int ext4_journalled_write_end(str
 	int partial = 0;
 	unsigned from, to;
 
-	from = pos & (PAGE_CACHE_SIZE - 1);
+	from = page_cache_offset(mapping, pos);
 	to = from + len;
 
 	if (copied < len) {

@@ -1579,6 +1579,7 @@ static int ext4_ordered_writepage(struct
 	handle_t *handle = NULL;
 	int ret = 0;
 	int err;
+	int pagesize = page_cache_size(inode->i_mapping);
 
 	J_ASSERT(PageLocked(page));
 

@@ -1601,8 +1602,7 @@ static int ext4_ordered_writepage(struct
 				(1 << BH_Dirty)|(1 << BH_Uptodate));
 	}
 	page_bufs = page_buffers(page);
-	walk_page_buffers(handle, page_bufs, 0,
-			PAGE_CACHE_SIZE, NULL, bget_one);
+	walk_page_buffers(handle, page_bufs, 0, pagesize, NULL, bget_one);
 
 	ret = block_write_full_page(page, ext4_get_block, wbc);
 

@@ -1619,13 +1619,12 @@ static int ext4_ordered_writepage(struct
 	 * and generally junk.
 	 */
 	if (ret == 0) {
-		err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
+		err = walk_page_buffers(handle, page_bufs, 0, pagesize,
 					NULL, jbd2_journal_dirty_data_fn);
 		if (!ret)
 			ret = err;
 	}
-	walk_page_buffers(handle, page_bufs, 0,
-			PAGE_CACHE_SIZE, NULL, bput_one);
+	walk_page_buffers(handle, page_bufs, 0, pagesize, NULL, bput_one);
 	err = ext4_journal_stop(handle);
 	if (!ret)
 		ret = err;

@@ -1677,6 +1676,7 @@ static int ext4_journalled_writepage(str
 	handle_t *handle = NULL;
 	int ret = 0;
 	int err;
+	int pagesize = page_cache_size(inode->i_mapping);
 
 	if (ext4_journal_current_handle())
 		goto no_write;

@@ -1693,17 +1693,17 @@ static int ext4_journalled_writepage(str
 		 * doesn't seem much point in redirtying the page here.
 		 */
 		ClearPageChecked(page);
-		ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+		ret = block_prepare_write(page, 0, page_cache_size(mapping),
 					ext4_get_block);
 		if (ret != 0) {
 			ext4_journal_stop(handle);
 			goto out_unlock;
 		}
 		ret = walk_page_buffers(handle, page_buffers(page), 0,
-			PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+			page_cache_size(mapping), NULL, do_journal_get_write_access);
 
 		err = walk_page_buffers(handle, page_buffers(page), 0,
-				PAGE_CACHE_SIZE, NULL, write_end_fn);
+			page_cache_size(mapping), NULL, write_end_fn);
 		if (ret == 0)
 			ret = err;
 		EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;

@@ -1936,8 +1936,8 @@ void ext4_set_aops(struct inode *inode)
 int ext4_block_truncate_page(handle_t *handle, struct page *page,
 		struct address_space *mapping, loff_t from)
 {
-	ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
-	unsigned offset = from & (PAGE_CACHE_SIZE-1);
+	ext4_fsblk_t index = page_cache_index(mapping, from);
+	unsigned offset = page_cache_offset(mapping, from);
 	unsigned blocksize, length, pos;
 	ext4_lblk_t iblock;
 	struct inode *inode = mapping->host;

@@ -1946,7 +1946,8 @@ int ext4_block_truncate_page(handle_t *h
 
 	blocksize = inode->i_sb->s_blocksize;
 	length = blocksize - (offset & (blocksize - 1));
-	iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
+	iblock = index <<
+		(page_cache_shift(mapping) - inode->i_sb->s_blocksize_bits);
 
 	/*
 	 * For "nobh" option,  we can only work if we don't need to

@@ -2426,7 +2427,7 @@ void ext4_truncate(struct inode *inode)
 		page = NULL;
 	} else {
 		page = grab_cache_page(mapping,
-				inode->i_size >> PAGE_CACHE_SHIFT);
+				page_cache_index(mapping, inode->i_size));
 		if (!page)
 			return;
 	}

Index: mm/fs/ext4/inode.c
===================================================================
@@ -1693,17 +1693,16 @@ static int ext4_journalled_writepage(str
 		 * doesn't seem much point in redirtying the page here.
 		 */
 		ClearPageChecked(page);
-		ret = block_prepare_write(page, 0, page_cache_size(mapping),
-					ext4_get_block);
+		ret = block_prepare_write(page, 0, pagesize, ext4_get_block);
 		if (ret != 0) {
 			ext4_journal_stop(handle);
 			goto out_unlock;
 		}
 		ret = walk_page_buffers(handle, page_buffers(page), 0,
-			page_cache_size(mapping), NULL, do_journal_get_write_access);
+			pagesize, NULL, do_journal_get_write_access);
 
 		err = walk_page_buffers(handle, page_buffers(page), 0,
-			page_cache_size(mapping), NULL, write_end_fn);
+			pagesize, NULL, write_end_fn);
 		if (ret == 0)
 			ret = err;
 		EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;

Index: mm/fs/reiserfs/file.c
===================================================================
@@ -161,11 +161,12 @@ int reiserfs_commit_page(struct inode *i
 	int partial = 0;
 	unsigned blocksize;
 	struct buffer_head *bh, *head;
-	unsigned long i_size_index = inode->i_size >> PAGE_CACHE_SHIFT;
+	unsigned long i_size_index =
+		page_cache_index(inode->i_mapping, inode->i_size);
 	int new;
 	int logit = reiserfs_file_data_log(inode);
 	struct super_block *s = inode->i_sb;
-	int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize;
+	int bh_per_page = page_cache_size(inode->i_mapping) / s->s_blocksize;
 	struct reiserfs_transaction_handle th;
 	int ret = 0;
 

@@ -260,6 +261,7 @@ static ssize_t reiserfs_file_write(struc
 	/* To simplify coding at this time, we store
 	   locked pages in array for now */
 	struct reiserfs_transaction_handle th;
+	struct address_space *mapping = inode->i_mapping;
 	th.t_trans_id = 0;
 
 	/* If a filesystem is converted from 3.5 to 3.6, we'll have v3.5 items

Index: mm/fs/reiserfs/inode.c
===================================================================
@@ -337,7 +337,8 @@ static int _get_block_create_0(struct in
 		goto finished;
 	}
 	// read file tail into part of page
-	offset = (cpu_key_k_offset(&key) - 1) & (PAGE_CACHE_SIZE - 1);
+	offset = page_cache_offset(inode->i_mapping,
+				cpu_key_k_offset(&key) - 1);
 	fs_gen = get_generation(inode->i_sb);
 	copy_item_head(&tmp_ih, ih);
 

@@ -523,10 +524,10 @@ static int convert_tail_for_hole(struct 
 		return -EIO;
 
 	/* always try to read until the end of the block */
-	tail_start = tail_offset & (PAGE_CACHE_SIZE - 1);
+	tail_start = page_cache_offset(inode->i_mapping, tail_offset);
 	tail_end = (tail_start | (bh_result->b_size - 1)) + 1;
 
-	index = tail_offset >> PAGE_CACHE_SHIFT;
+	index = page_cache_index(inode->i_mapping, tail_offset);
 	/* hole_page can be zero in case of direct_io, we are sure
 	   that we cannot get here if we write with O_DIRECT into
 	   tail page */

@@ -2000,11 +2001,13 @@ static int grab_tail_page(struct inode *
 	/* we want the page with the last byte in the file,
 	 ** not the page that will hold the next byte for appending
 	 */
-	unsigned long index = (p_s_inode->i_size - 1) >> PAGE_CACHE_SHIFT;
+	unsigned long index = page_cache_index(p_s_inode->i_mapping,
+						p_s_inode->i_size - 1);
 	unsigned long pos = 0;
 	unsigned long start = 0;
 	unsigned long blocksize = p_s_inode->i_sb->s_blocksize;
-	unsigned long offset = (p_s_inode->i_size) & (PAGE_CACHE_SIZE - 1);
+	unsigned long offset = page_cache_index(p_s_inode->i_mapping,
+							p_s_inode->i_size);
 	struct buffer_head *bh;
 	struct buffer_head *head;
 	struct page *page;

@@ -2076,7 +2079,8 @@ int reiserfs_truncate_file(struct inode 
 {
 	struct reiserfs_transaction_handle th;
 	/* we want the offset for the first byte after the end of the file */
-	unsigned long offset = p_s_inode->i_size & (PAGE_CACHE_SIZE - 1);
+	unsigned long offset = page_cache_offset(p_s_inode->i_mapping,
+							p_s_inode->i_size);
 	unsigned blocksize = p_s_inode->i_sb->s_blocksize;
 	unsigned length;
 	struct page *page = NULL;

@@ -2225,7 +2229,7 @@ static int map_block_for_writepage(struc
 	} else if (is_direct_le_ih(ih)) {
 		char *p;
 		p = page_address(bh_result->b_page);
-		p += (byte_offset - 1) & (PAGE_CACHE_SIZE - 1);
+		p += page_cache_offset(inode->i_mapping, byte_offset - 1);
 		copy_size = ih_item_len(ih) - pos_in_item;
 
 		fs_gen = get_generation(inode->i_sb);

@@ -2324,7 +2328,8 @@ static int reiserfs_write_full_page(stru
 				    struct writeback_control *wbc)
 {
 	struct inode *inode = page->mapping->host;
-	unsigned long end_index = inode->i_size >> PAGE_CACHE_SHIFT;
+	unsigned long end_index = page_cache_index(inode->i_mapping,
+							inode->i_size);
 	int error = 0;
 	unsigned long block;
 	sector_t last_block;

@@ -2334,7 +2339,7 @@ static int reiserfs_write_full_page(stru
 	int checked = PageChecked(page);
 	struct reiserfs_transaction_handle th;
 	struct super_block *s = inode->i_sb;
-	int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize;
+	int bh_per_page = page_cache_size(inode->i_mapping) / s->s_blocksize;
 	th.t_trans_id = 0;
 
 	/* no logging allowed when nonblocking or from PF_MEMALLOC */

@@ -2361,16 +2366,18 @@ static int reiserfs_write_full_page(stru
 	if (page->index >= end_index) {
 		unsigned last_offset;
 
-		last_offset = inode->i_size & (PAGE_CACHE_SIZE - 1);
+		last_offset = page_cache_offset(inode->i_mapping, inode->i_size);
 		/* no file contents in this page */
 		if (page->index >= end_index + 1 || !last_offset) {
 			unlock_page(page);
 			return 0;
 		}
-		zero_user_segment(page, last_offset, PAGE_CACHE_SIZE);
+		zero_user_segment(page, last_offset,
+				page_cache_size(inode->i_mapping));
 	}
 	bh = head;
-	block = page->index << (PAGE_CACHE_SHIFT - s->s_blocksize_bits);
+	block = page->index << (page_cache_shift(inode->i_mapping)
+						- s->s_blocksize_bits);
 	last_block = (i_size_read(inode) - 1) >> inode->i_blkbits;
 	/* first map all the buffers, logging any direct items we find */
 	do {

@@ -2765,7 +2772,7 @@ int reiserfs_commit_write(struct file *f
 			  unsigned from, unsigned to)
 {
 	struct inode *inode = page->mapping->host;
-	loff_t pos = ((loff_t) page->index << PAGE_CACHE_SHIFT) + to;
+	loff_t pos = page_cache_pos(page->mapping, page->index, to);
 	int ret = 0;
 	int update_sd = 0;
 	struct reiserfs_transaction_handle *th = NULL;

Index: mm/fs/reiserfs/ioctl.c
===================================================================
@@ -194,8 +194,8 @@ static int reiserfs_unpack(struct inode 
 	 ** reiserfs_prepare_write on that page.  This will force a 
 	 ** reiserfs_get_block to unpack the tail for us.
 	 */
-	index = inode->i_size >> PAGE_CACHE_SHIFT;
 	mapping = inode->i_mapping;
+	index = page_cache_index(mapping, inode->i_size);
 	page = grab_cache_page(mapping, index);
 	retval = -ENOMEM;
 	if (!page) {

Index: mm/fs/reiserfs/stree.c
===================================================================
@@ -1283,7 +1283,8 @@ int reiserfs_delete_item(struct reiserfs
 		 */
 
 		data = kmap_atomic(p_s_un_bh->b_page, KM_USER0);
-		off = ((le_ih_k_offset(&s_ih) - 1) & (PAGE_CACHE_SIZE - 1));
+		off = page_cache_offset(p_s_inode->i_mapping,
+					le_ih_k_offset(&s_ih) - 1);
 		memcpy(data + off,
 		       B_I_PITEM(PATH_PLAST_BUFFER(p_s_path), &s_ih),
 		       n_ret_value);

@@ -1439,7 +1440,7 @@ static void unmap_buffers(struct page *p
 
 	if (page) {
 		if (page_has_buffers(page)) {
-			tail_index = pos & (PAGE_CACHE_SIZE - 1);
+			tail_index = page_cache_offset(page_mapping(page), pos);
 			cur_index = 0;
 			head = page_buffers(page);
 			bh = head;

Index: mm/fs/reiserfs/tail_conversion.c
===================================================================
@@ -128,7 +128,8 @@ int direct2indirect(struct reiserfs_tran
 	 */
 	if (up_to_date_bh) {
 		unsigned pgoff =
-		    (tail_offset + total_tail - 1) & (PAGE_CACHE_SIZE - 1);
+			page_cache_offset(inode->i_mapping,
+			tail_offset + total_tail - 1);
 		char *kaddr = kmap_atomic(up_to_date_bh->b_page, KM_USER0);
 		memset(kaddr + pgoff, 0, n_blk_size - total_tail);
 		kunmap_atomic(kaddr, KM_USER0);

@@ -238,7 +239,7 @@ int indirect2direct(struct reiserfs_tran
 	 ** the page was locked and this part of the page was up to date when
 	 ** indirect2direct was called, so we know the bytes are still valid
 	 */
-	tail = tail + (pos & (PAGE_CACHE_SIZE - 1));
+	tail = tail + page_cache_offset(p_s_inode->i_mapping, pos);
 
 	PATH_LAST_POSITION(p_s_path)++;
 

Index: mm/fs/reiserfs/xattr.c
===================================================================
@@ -468,13 +468,13 @@ reiserfs_xattr_set(struct inode *inode, 
 	while (buffer_pos < buffer_size || buffer_pos == 0) {
 		size_t chunk;
 		size_t skip = 0;
-		size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
-		if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
-			chunk = PAGE_CACHE_SIZE;
+		size_t page_offset = page_cache_offset(mapping, file_pos);
+		if (buffer_size - buffer_pos > page_cache_size(mapping))
+			chunk = page_cache_size(mapping);
 		else
 			chunk = buffer_size - buffer_pos;
 
-		page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
+		page = reiserfs_get_page(xinode, page_cache_index(mapping, file_pos));
 		if (IS_ERR(page)) {
 			err = PTR_ERR(page);
 			goto out_filp;

@@ -486,8 +486,8 @@ reiserfs_xattr_set(struct inode *inode, 
 		if (file_pos == 0) {
 			struct reiserfs_xattr_header *rxh;
 			skip = file_pos = sizeof(struct reiserfs_xattr_header);
-			if (chunk + skip > PAGE_CACHE_SIZE)
-				chunk = PAGE_CACHE_SIZE - skip;
+			if (chunk + skip > page_cache_size(mapping))
+				chunk = page_cache_size(mapping) - skip;
 			rxh = (struct reiserfs_xattr_header *)data;
 			rxh->h_magic = cpu_to_le32(REISERFS_XATTR_MAGIC);
 			rxh->h_hash = cpu_to_le32(xahash);

@@ -577,12 +577,13 @@ reiserfs_xattr_get(const struct inode *i
 		size_t chunk;
 		char *data;
 		size_t skip = 0;
-		if (isize - file_pos > PAGE_CACHE_SIZE)
-			chunk = PAGE_CACHE_SIZE;
+		if (isize - file_pos > page_cache_size(xinode->i_mapping))
+			chunk = page_cache_size(xinode->i_mapping);
 		else
 			chunk = isize - file_pos;
 
-		page = reiserfs_get_page(xinode, file_pos >> PAGE_CACHE_SHIFT);
+		page = reiserfs_get_page(xinode,
+				page_cache_index(xinode->i_mapping, file_pos));
 		if (IS_ERR(page)) {
 			err = PTR_ERR(page);
 			goto out_dput;

Index: mm/fs/reiserfs/inode.c
===================================================================
@@ -2006,7 +2006,7 @@ static int grab_tail_page(struct inode *
 	unsigned long pos = 0;
 	unsigned long start = 0;
 	unsigned long blocksize = p_s_inode->i_sb->s_blocksize;
-	unsigned long offset = page_cache_index(p_s_inode->i_mapping,
+	unsigned long offset = page_cache_offset(p_s_inode->i_mapping,
 							p_s_inode->i_size);
 	struct buffer_head *bh;
 	struct buffer_head *head;

Index: mm/fs/xfs/linux-2.6/xfs_aops.c
===================================================================
@@ -75,7 +75,7 @@ xfs_page_trace(
 	xfs_inode_t	*ip;
 	bhv_vnode_t	*vp = vn_from_inode(inode);
 	loff_t		isize = i_size_read(inode);
-	loff_t		offset = page_offset(page);
+	loff_t		offset = page_cache_offset(page->mapping);
 	int		delalloc = -1, unmapped = -1, unwritten = -1;
 
 	if (page_has_buffers(page))

@@ -618,7 +618,7 @@ xfs_probe_page(
 					break;
 			} while ((bh = bh->b_this_page) != head);
 		} else
-			ret = mapped ? 0 : PAGE_CACHE_SIZE;
+			ret = mapped ? 0 : page_cache_size(page->mapping);
 	}
 
 	return ret;

@@ -645,7 +645,7 @@ xfs_probe_cluster(
 	} while ((bh = bh->b_this_page) != head);
 
 	/* if we reached the end of the page, sum forwards in following pages */
-	tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
+	tlast = page_cache_index(inode->i_mapping, i_size_read(inode));
 	tindex = startpage->index + 1;
 
 	/* Prune this back to avoid pathological behavior */

@@ -663,14 +663,14 @@ xfs_probe_cluster(
 			size_t pg_offset, pg_len = 0;
 
 			if (tindex == tlast) {
-				pg_offset =
-				    i_size_read(inode) & (PAGE_CACHE_SIZE - 1);
+				pg_offset = page_cache_offset(inode->i_mapping,
+							i_size_read(inode));
 				if (!pg_offset) {
 					done = 1;
 					break;
 				}
 			} else
-				pg_offset = PAGE_CACHE_SIZE;
+				pg_offset = page_cache_size(inode->i_mapping);
 
 			if (page->index == tindex && !TestSetPageLocked(page)) {
 				pg_len = xfs_probe_page(page, pg_offset, mapped);

@@ -752,7 +752,8 @@ xfs_convert_page(
 	int			bbits = inode->i_blkbits;
 	int			len, page_dirty;
 	int			count = 0, done = 0, uptodate = 1;
- 	xfs_off_t		offset = page_offset(page);
+	struct address_space	*map = inode->i_mapping;
+	xfs_off_t		offset = page_cache_pos(map, page->index, 0);
 
 	if (page->index != tindex)
 		goto fail;

@@ -760,7 +761,7 @@ xfs_convert_page(
 		goto fail;
 	if (PageWriteback(page))
 		goto fail_unlock_page;
-	if (page->mapping != inode->i_mapping)
+	if (page->mapping != map)
 		goto fail_unlock_page;
 	if (!xfs_is_delayed_page(page, (*ioendp)->io_type))
 		goto fail_unlock_page;

@@ -772,20 +773,20 @@ xfs_convert_page(
 	 * Derivation:
 	 *
 	 * End offset is the highest offset that this page should represent.
-	 * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
-	 * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
+	 * If we are on the last page, (end_offset & page_cache_mask())
+	 * will evaluate non-zero and be less than page_cache_size() and
 	 * hence give us the correct page_dirty count. On any other page,
 	 * it will be zero and in that case we need page_dirty to be the
 	 * count of buffers on the page.
 	 */
 	end_offset = min_t(unsigned long long,
-			(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT,
+			(xfs_off_t)(page->index + 1) << page_cache_shift(map),
 			i_size_read(inode));
 
 	len = 1 << inode->i_blkbits;
-	p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
-					PAGE_CACHE_SIZE);
-	p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
+	p_offset = min_t(unsigned long, page_cache_offset(map, end_offset),
+					page_cache_size(map));
+	p_offset = p_offset ? roundup(p_offset, len) : page_cache_size(map);
 	page_dirty = p_offset / len;
 
 	bh = head = page_buffers(page);

@@ -941,6 +942,8 @@ xfs_page_state_convert(
 	int			page_dirty, count = 0;
 	int			trylock = 0;
 	int			all_bh = unmapped;
+	struct address_space	*map = inode->i_mapping;
+	int			pagesize = page_cache_size(map);
 
 	if (startio) {
 		if (wbc->sync_mode == WB_SYNC_NONE && wbc->nonblocking)

@@ -949,11 +952,11 @@ xfs_page_state_convert(
 
 	/* Is this page beyond the end of the file? */
 	offset = i_size_read(inode);
-	end_index = offset >> PAGE_CACHE_SHIFT;
-	last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
+	end_index = page_cache_index(map, offset);
+	last_index = page_cache_index(map, (offset - 1));
 	if (page->index >= end_index) {
 		if ((page->index >= end_index + 1) ||
-		    !(i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
+		    !(page_cache_offset(map, i_size_read(inode)))) {
 			if (startio)
 				unlock_page(page);
 			return 0;

@@ -967,22 +970,22 @@ xfs_page_state_convert(
 	 * Derivation:
 	 *
 	 * End offset is the highest offset that this page should represent.
-	 * If we are on the last page, (end_offset & (PAGE_CACHE_SIZE - 1))
-	 * will evaluate non-zero and be less than PAGE_CACHE_SIZE and
-	 * hence give us the correct page_dirty count. On any other page,
+	 * If we are on the last page, (page_cache_offset(mapping, end_offset))
+	 * will evaluate non-zero and be less than page_cache_size(mapping)
+	 * and hence give us the correct page_dirty count. On any other page,
 	 * it will be zero and in that case we need page_dirty to be the
 	 * count of buffers on the page.
  	 */
 	end_offset = min_t(unsigned long long,
-			(xfs_off_t)(page->index + 1) << PAGE_CACHE_SHIFT, offset);
+			(xfs_off_t)page_cache_pos(map, page->index + 1, 0), offset);
 	len = 1 << inode->i_blkbits;
-	p_offset = min_t(unsigned long, end_offset & (PAGE_CACHE_SIZE - 1),
-					PAGE_CACHE_SIZE);
-	p_offset = p_offset ? roundup(p_offset, len) : PAGE_CACHE_SIZE;
+	p_offset = min_t(unsigned long, page_cache_offset(map, end_offset),
+					pagesize);
+	p_offset = p_offset ? roundup(p_offset, len) : pagesize;
 	page_dirty = p_offset / len;
 
 	bh = head = page_buffers(page);
-	offset = page_offset(page);
+	offset = page_cache_pos(map, page->index, 0);
 	flags = BMAPI_READ;
 	type = IOMAP_NEW;
 

@@ -1130,7 +1133,7 @@ xfs_page_state_convert(
 
 	if (ioend && iomap_valid) {
 		offset = (iomap.iomap_offset + iomap.iomap_bsize - 1) >>
-					PAGE_CACHE_SHIFT;
+					page_cache_shift(map);
 		tlast = min_t(pgoff_t, offset, last_index);
 		xfs_cluster_write(inode, page->index + 1, &iomap, &ioend,
 					wbc, startio, all_bh, tlast);

Index: mm/fs/xfs/linux-2.6/xfs_lrw.c
===================================================================
@@ -142,8 +142,8 @@ xfs_iozero(
 		unsigned offset, bytes;
 		void *fsdata;
 
-		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
-		bytes = PAGE_CACHE_SIZE - offset;
+		offset = page_cache_offset(mapping, pos); /* Within page */
+		bytes = page_cache_size(mapping) - offset;
 		if (bytes > count)
 			bytes = count;