Soft updates bug fix: Set the flags on the buffer describing our intentions

before we call bioops.io_start. However, don't move buffer memory to
parent until bioops.io_start has had a chance to do its thing (otherwise,
io_start will be very disappointed went it tries to read the buffer :)

Thanks to Todd T. Fries for finding this one!

1 files changed, 9 insertions, 7 deletions

diff --git a/sys/kern/vfs_cluster.c b/sys/kern/vfs_cluster.c
index c5a3974c051..924b11f1403 100644
--- a/sys/kern/vfs_cluster.c
+++ b/sys/kern/vfs_cluster.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: vfs_cluster.c,v 1.11 1997/11/06 05:58:26 csapuntz Exp $	*/
+/*	$OpenBSD: vfs_cluster.c,v 1.12 1998/01/08 15:51:56 csapuntz Exp $	*/
 /*	$NetBSD: vfs_cluster.c,v 1.12 1996/04/22 01:39:05 christos Exp $	*/
 
 /*-
@@ -698,6 +698,13 @@ redo:
 			panic("Clustered write to wrong blocks");
 		}
 
+		/*
+		 * We might as well AGE the buffer here; it's either empty, or
+		 * contains data that we couldn't get rid of (but wanted to).
+		 */
+		tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
+		tbp->b_flags |= (B_ASYNC | B_AGE);
+
 		if (LIST_FIRST(&tbp->b_dep) != NULL && bioops.io_start)
 			(*bioops.io_start)(tbp);
 
@@ -706,12 +713,7 @@ redo:
 		bp->b_bufsize += size;
 
 		tbp->b_bufsize -= size;
-		tbp->b_flags &= ~(B_READ | B_DONE | B_ERROR | B_DELWRI);
-		/*
-		 * We might as well AGE the buffer here; it's either empty, or
-		 * contains data that we couldn't get rid of (but wanted to).
-		 */
-		tbp->b_flags |= (B_ASYNC | B_AGE);
+
 		s = splbio();
 		reassignbuf(tbp, tbp->b_vp);		/* put on clean list */
 		++tbp->b_vp->v_numoutput;