UBC was a disaster. It worked very good when it worked, but on some

machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

1 files changed, 38 insertions, 5 deletions

diff --git a/sys/nfs/nfs_syscalls.c b/sys/nfs/nfs_syscalls.c
index 5a189ba344d..87c1618a4a4 100644
--- a/sys/nfs/nfs_syscalls.c
+++ b/sys/nfs/nfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_syscalls.c,v 1.21 2001/11/27 05:27:12 art Exp $	*/
+/*	$OpenBSD: nfs_syscalls.c,v 1.22 2001/12/19 08:58:06 art Exp $	*/
 /*	$NetBSD: nfs_syscalls.c,v 1.19 1996/02/18 11:53:52 fvdl Exp $	*/
 
 /*
@@ -913,9 +913,10 @@ int
 nfssvc_iod(p)
 	struct proc *p;
 {
-	struct buf *bp;
-	int i, myiod;
-	int error = 0;
+	register struct buf *bp, *nbp;
+	register int i, myiod;
+	struct vnode *vp;
+	int error = 0, s;
 
 	/*
 	 * Assign my position or return error if too many already running
@@ -943,7 +944,39 @@ nfssvc_iod(p)
 	    while ((bp = nfs_bufq.tqh_first) != NULL) {
 		/* Take one off the front of the list */
 		TAILQ_REMOVE(&nfs_bufq, bp, b_freelist);
-		(void) nfs_doio(bp, NULL);
+		if (bp->b_flags & B_READ)
+		    (void) nfs_doio(bp, NULL);
+		else do {
+		    /*
+		     * Look for a delayed write for the same vnode, so I can do 
+		     * it now. We must grab it before calling nfs_doio() to
+		     * avoid any risk of the vnode getting vclean()'d while
+		     * we are doing the write rpc.
+		     */
+		    vp = bp->b_vp;
+		    s = splbio();
+		    for (nbp = vp->v_dirtyblkhd.lh_first; nbp;
+			nbp = nbp->b_vnbufs.le_next) {
+			if ((nbp->b_flags &
+			    (B_BUSY|B_DELWRI|B_NEEDCOMMIT|B_NOCACHE))!=B_DELWRI)
+			    continue;
+			bremfree(nbp);
+			nbp->b_flags |= (B_BUSY|B_ASYNC);
+			break;
+		    }
+		    /*
+		     * For the delayed write, do the first part of nfs_bwrite()
+		     * up to, but not including nfs_strategy().
+		     */
+		    if (nbp) {
+			nbp->b_flags &= ~(B_READ|B_DONE|B_ERROR);
+			buf_undirty(bp);
+			nbp->b_vp->v_numoutput++;
+		    }
+		    splx(s);
+
+		    (void) nfs_doio(bp, NULL);
+		} while ((bp = nbp) != NULL);
 	    }
 	    if (error) {
 		PRELE(p);