+ int error = shmem_getpage(inode, page->index, &page, SGP_CACHE, NULL);
+ unlock_page(page);
+ return error;
+}
+
+static int
+shmem_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ *pagep = NULL;
+ return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
+}
+
+static int
+shmem_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+
+ set_page_dirty(page);
+ page_cache_release(page);
+
+ if (pos+copied > inode->i_size)
+ i_size_write(inode, pos+copied);
+
+ return copied;