int ret = 0;
BUG_ON(!PageLocked(page));
- if (PageDirty(page) || PageWriteback(page))
+ if (PageWriteback(page))
return 0;
if (mapping == NULL) { /* can this still happen? */
spin_lock(&mapping->private_lock);
ret = drop_buffers(page, &buffers_to_free);
+
+ /*
+ * If the filesystem writes its buffers by hand (eg ext3)
+ * then we can have clean buffers against a dirty page. We
+ * clean the page here; otherwise the VM will never notice
+ * that the filesystem did any IO at all.
+ *
+ * Also, during truncate, discard_buffer will have marked all
+ * the page's buffers clean. We discover that here and clean
+ * the page also.
+ *
+ * private_lock must be held over this entire operation in order
+ * to synchronise against __set_page_dirty_buffers and prevent the
+ * dirty bit from being lost.
+ */
+ if (ret)
+ cancel_dirty_page(page, PAGE_CACHE_SIZE);
spin_unlock(&mapping->private_lock);
out:
if (buffers_to_free) {