The `truncated' page in block_write_full_page() may stick for a long time.
E.g. ext2_rmdir() will set i_size to 0, and then the dir inode may hang around
because of being referenced by someone.

So clear PAGECACHE_TAG_DIRTY to prevent pdflush from retrying and iowaiting on
it.

Tested-by: Joerg Platte <jplatte@naasa.net>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
---
fs/buffer.c |    2 ++
 1 files changed, 2 insertions(+)

Index: linux/fs/buffer.c
===================================================================
--- linux.orig/fs/buffer.c
+++ linux/fs/buffer.c
@@ -2820,7 +2820,9 @@ int block_write_full_page(struct page *p
 		 * freeable here, so the page does not leak.
 		 */
 		do_invalidatepage(page, 0);
+		set_page_writeback(page);
 		unlock_page(page);
+		end_page_writeback(page);
 		return 0; /* don't care */
 	}
 
--