[PATCH 2/2] xfs: enforce synchronous writes in xfs_bwrite

[Christoph Hellwig]

xfs_bwrite is used with the intention of synchronously writing out buffers,
but currently it does not actually clear the async flag if that's left
from previous writes but instead implements async behaviour if it finds it.
Remove the code handling asynchronous writes as we've got rid of those
entirely outside of the log and delwri buffers, and make sure that we
clear the async and read flags before writing the buffer.

Signed-off-by: Christoph Hellwig <hch at lst.de>

Index: xfs/fs/xfs/linux-2.6/xfs_buf.c
===================================================================
--- xfs.orig/fs/xfs/linux-2.6/xfs_buf.c	2010-03-11 11:42:41.596003157 +0100
+++ xfs/fs/xfs/linux-2.6/xfs_buf.c	2010-03-11 11:44:34.473008395 +0100
@@ -1056,25 +1056,20 @@ xfs_bwrite(
 	struct xfs_mount	*mp,
 	struct xfs_buf		*bp)
 {
-	int			iowait = (bp->b_flags & XBF_ASYNC) == 0;
-	int			error = 0;
+	int			error;
 
 	bp->b_strat = xfs_bdstrat_cb;
 	bp->b_mount = mp;
 	bp->b_flags |= XBF_WRITE;
-	if (!iowait)
-		bp->b_flags |= _XBF_RUN_QUEUES;
+	bp->b_flags &= ~(XBF_ASYNC | XBF_READ);
 
 	xfs_buf_delwri_dequeue(bp);
 	xfs_buf_iostrategy(bp);
 
-	if (iowait) {
-		error = xfs_buf_iowait(bp);
-		if (error)
-			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
-		xfs_buf_relse(bp);
-	}
-
+	error = xfs_buf_iowait(bp);
+	if (error)
+		xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
+	xfs_buf_relse(bp);
 	return error;
 }
 
Index: xfs/fs/xfs/linux-2.6/xfs_sync.c
===================================================================
--- xfs.orig/fs/xfs/linux-2.6/xfs_sync.c	2010-03-11 11:44:58.473010700 +0100
+++ xfs/fs/xfs/linux-2.6/xfs_sync.c	2010-03-11 11:45:03.199256475 +0100
@@ -364,7 +364,6 @@ xfs_sync_fsdata(
 	if (XFS_BUF_ISPINNED(bp))
 		xfs_log_force(mp, 0);
 
-	XFS_BUF_UNASYNC(bp);
 	return xfs_bwrite(mp, bp);
 }