[PATCH] blockdev direct_io: fix signedness bug

size_t is unsigned.  IO errors aren't getting through.

Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 8b18e43..da020be 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -146,7 +146,7 @@
 		iocb->ki_nbytes = -EIO;
 
 	if (atomic_dec_and_test(bio_count)) {
-		if (iocb->ki_nbytes < 0)
+		if ((long)iocb->ki_nbytes < 0)
 			aio_complete(iocb, iocb->ki_nbytes, 0);
 		else
 			aio_complete(iocb, iocb->ki_left, 0);