[PATCH] mpage_end_io_write() I/O error handling fix

When fsync() runs wait_on_page_writeback_range() it only inspects pages which
are actually under I/O (PAGECACHE_TAG_WRITEBACK).  If a page completed I/O
prior to wait_on_page_writeback_range() looking at it, it is supposed to have
recorded its I/O error state in the address_space.

But mpage_mpage_end_io_write() forgot to set the address_space error flag in
this case.

Signed-off-by: Qu Fuping <fs@ercist.iscas.ac.cn>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/mpage.c

@@ -79,8 +79,11 @@ static int mpage_end_io_write(struct bio *bio, unsigned int bytes_done, int err)
 		if (--bvec >= bio->bi_io_vec)
 			prefetchw(&bvec->bv_page->flags);
 
-		if (!uptodate)
+		if (!uptodate){
 			SetPageError(page);
+			if (page->mapping)
+				set_bit(AS_EIO, &page->mapping->flags);
+		}
 		end_page_writeback(page);
 	} while (bvec >= bio->bi_io_vec);
 	bio_put(bio);