xfs: defer AIO/DIO completions

We really shouldn't complete AIO or DIO requests until we have finished
the unwritten extent conversion and size update.  This means fsync never
has to pick up any ioends as all work has been completed when signalling
I/O completion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>


diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index d915644..10660c3 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -122,6 +122,11 @@
 		bh->b_end_io(bh, !ioend->io_error);
 	}
 
+	if (ioend->io_iocb) {
+		if (ioend->io_isasync)
+			aio_complete(ioend->io_iocb, ioend->io_result, 0);
+		inode_dio_done(ioend->io_inode);
+	}
 	xfs_ioend_wake(ip);
 	mempool_free(ioend, xfs_ioend_pool);
 }
@@ -236,8 +241,6 @@
 		/* ensure we don't spin on blocked ioends */
 		delay(1);
 	} else {
-		if (ioend->io_iocb)
-			aio_complete(ioend->io_iocb, ioend->io_result, 0);
 		xfs_destroy_ioend(ioend);
 	}
 }
@@ -274,6 +277,7 @@
 	 * all the I/O from calling the completion routine too early.
 	 */
 	atomic_set(&ioend->io_remaining, 1);
+	ioend->io_isasync = 0;
 	ioend->io_error = 0;
 	ioend->io_list = NULL;
 	ioend->io_type = type;
@@ -1289,7 +1293,6 @@
 	bool			is_async)
 {
 	struct xfs_ioend	*ioend = iocb->private;
-	struct inode		*inode = ioend->io_inode;
 
 	/*
 	 * blockdev_direct_IO can return an error even after the I/O
@@ -1300,28 +1303,17 @@
 
 	ioend->io_offset = offset;
 	ioend->io_size = size;
+	ioend->io_iocb = iocb;
+	ioend->io_result = ret;
 	if (private && size > 0)
 		ioend->io_type = IO_UNWRITTEN;
 
 	if (is_async) {
-		/*
-		 * If we are converting an unwritten extent we need to delay
-		 * the AIO completion until after the unwrittent extent
-		 * conversion has completed, otherwise do it ASAP.
-		 */
-		if (ioend->io_type == IO_UNWRITTEN) {
-			ioend->io_iocb = iocb;
-			ioend->io_result = ret;
-		} else {
-			aio_complete(iocb, ret, 0);
-		}
+		ioend->io_isasync = 1;
 		xfs_finish_ioend(ioend);
 	} else {
 		xfs_finish_ioend_sync(ioend);
 	}
-
-	/* XXX: probably should move into the real I/O completion handler */
-	inode_dio_done(inode);
 }
 
 STATIC ssize_t