#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/swap.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
do_invalidatepage */
+/**
+ * do_invalidatepage - invalidate part of all of a page
+ * @page: the page which is affected
+ * @offset: the index of the truncation point
+ *
+ * do_invalidatepage() is called when all or part of the page has become
+ * invalidated by a truncate operation.
+ *
+ * do_invalidatepage() does not have to release all buffers, but it must
+ * ensure that no dirty buffer is left outside @offset and that no I/O
+ * is underway against any of the blocks which are outside the truncation
+ * point. Because the caller is about to free (and possibly reuse) those
+ * blocks on-disk.
+ */
+void do_invalidatepage(struct page *page, unsigned long offset)
+{
+ void (*invalidatepage)(struct page *, unsigned long);
+ invalidatepage = page->mapping->a_ops->invalidatepage;
+#ifdef CONFIG_BLOCK
+ if (!invalidatepage)
+ invalidatepage = block_invalidatepage;
+#endif
+ if (invalidatepage)
+ (*invalidatepage)(page, offset);
+}
+
static inline void truncate_partial_page(struct page *page, unsigned partial)
{
memclear_highpage_flush(page, partial, PAGE_CACHE_SIZE-partial);
/*
* This is for invalidate_inode_pages(). That function can be called at
* any time, and is not supposed to throw away dirty pages. But pages can
- * be marked dirty at any time too. So we re-check the dirtiness inside
- * ->tree_lock. That provides exclusion against the __set_page_dirty
- * functions.
+ * be marked dirty at any time too, so use remove_mapping which safely
+ * discards clean, unused pages.
*
* Returns non-zero if the page was successfully invalidated.
*/
static int
invalidate_complete_page(struct address_space *mapping, struct page *page)
{
+ int ret;
+
if (page->mapping != mapping)
return 0;
if (PagePrivate(page) && !try_to_release_page(page, 0))
return 0;
- write_lock_irq(&mapping->tree_lock);
- if (PageDirty(page))
- goto failed;
- if (page_count(page) != 2) /* caller's ref + pagecache ref */
- goto failed;
-
- BUG_ON(PagePrivate(page));
- __remove_from_page_cache(page);
- write_unlock_irq(&mapping->tree_lock);
+ ret = remove_mapping(mapping, page);
ClearPageUptodate(page);
- page_cache_release(page); /* pagecache ref */
- return 1;
-failed:
- write_unlock_irq(&mapping->tree_lock);
- return 0;
+
+ return ret;
}
/**