Don't jump the queue if we have to wait on the client side because

the nfs_bufq is full - instead tsleep waiting for one of our nfsiod's
to free up space for us in the queue so we can enqueue on the end.

ok blambert@, tedu@, oga@

4 files changed, 15 insertions, 10 deletions

diff --git a/sys/nfs/nfs_bio.c b/sys/nfs/nfs_bio.c
index c16791483d6..accd806410e 100644
--- a/sys/nfs/nfs_bio.c
+++ b/sys/nfs/nfs_bio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_bio.c,v 1.70 2010/04/09 22:42:10 oga Exp $	*/
+/*	$OpenBSD: nfs_bio.c,v 1.71 2010/04/12 16:37:38 beck Exp $	*/
 /*	$NetBSD: nfs_bio.c,v 1.25.4.2 1996/07/08 20:47:04 jtc Exp $	*/
 
 /*
@@ -156,7 +156,7 @@ nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
 				return (EINTR);
 			    if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) {
 				rabp->b_flags |= (B_READ | B_ASYNC);
-				if (nfs_asyncio(rabp)) {
+				if (nfs_asyncio(rabp, 1)) {
 				    rabp->b_flags |= B_INVAL;
 				    brelse(rabp);
 				}
@@ -492,13 +492,16 @@ nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred, struct proc *p)
  * are all hung on a dead server.
  */
 int
-nfs_asyncio(struct buf *bp)
+nfs_asyncio(struct buf *bp, int readahead)
 {
 	if (nfs_numasync == 0)
 		goto out;
 
-	if (nfs_bufqlen > nfs_bufqmax)
-		goto out; /* too many bufs in use, force sync */
+	while (nfs_bufqlen > nfs_bufqmax)
+		if (readahead)
+			goto out;
+		else
+			tsleep(&nfs_bufqlen, PRIBIO, "nfs_bufq", 0);
 
 	if ((bp->b_flags & B_READ) == 0) {
 		bp->b_flags |= B_WRITEINPROG;
diff --git a/sys/nfs/nfs_syscalls.c b/sys/nfs/nfs_syscalls.c
index 0b9c45ab4d7..77bfff39817 100644
--- a/sys/nfs/nfs_syscalls.c
+++ b/sys/nfs/nfs_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_syscalls.c,v 1.88 2009/10/19 22:24:18 jsg Exp $	*/
+/*	$OpenBSD: nfs_syscalls.c,v 1.89 2010/04/12 16:37:38 beck Exp $	*/
 /*	$NetBSD: nfs_syscalls.c,v 1.19 1996/02/18 11:53:52 fvdl Exp $	*/
 
 /*
@@ -591,6 +591,7 @@ nfssvc_iod(void *arg)
 	}
 
 	nfs_bufqmax += bufcount;
+	wakeup(&nfs_bufqlen); /* wake up anyone waiting for room to enqueue IO */
 
 	/* Just loop around doin our stuff until SIGKILL. */
 	for (;;) {
@@ -635,6 +636,7 @@ nfssvc_iod(void *arg)
 
 		    (void) nfs_doio(bp, NULL);
 		} while ((bp = nbp) != NULL);
+		wakeup_one(&nfs_bufqlen); /* wake up anyone waiting for room to enqueue IO */
 	    }
 	    if (error) {
 		nfs_asyncdaemon[myiod] = NULL;
diff --git a/sys/nfs/nfs_var.h b/sys/nfs/nfs_var.h
index 56fb97a615d..9ddc8398c20 100644
--- a/sys/nfs/nfs_var.h
+++ b/sys/nfs/nfs_var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_var.h,v 1.58 2009/09/02 18:20:54 thib Exp $	*/
+/*	$OpenBSD: nfs_var.h,v 1.59 2010/04/12 16:37:38 beck Exp $	*/
 /*	$NetBSD: nfs_var.h,v 1.3 1996/02/18 11:53:54 fvdl Exp $	*/
 
 /*
@@ -49,7 +49,7 @@ int nfs_bioread(struct vnode *, struct uio *, int, struct ucred *);
 int nfs_write(void *);
 struct buf *nfs_getcacheblk(struct vnode *, daddr64_t, int, struct proc *);
 int nfs_vinvalbuf(struct vnode *, int, struct ucred *, struct proc *);
-int nfs_asyncio(struct buf *);
+int nfs_asyncio(struct buf *, int readahead);
 int nfs_doio(struct buf *, struct proc *);
 
 /* nfs_boot.c */
diff --git a/sys/nfs/nfs_vnops.c b/sys/nfs/nfs_vnops.c
index 5f0fbf3d0b6..20e38f543bb 100644
--- a/sys/nfs/nfs_vnops.c
+++ b/sys/nfs/nfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nfs_vnops.c,v 1.128 2010/03/29 23:33:39 krw Exp $	*/
+/*	$OpenBSD: nfs_vnops.c,v 1.129 2010/04/12 16:37:38 beck Exp $	*/
 /*	$NetBSD: nfs_vnops.c,v 1.62.4.1 1996/07/08 20:26:52 jtc Exp $	*/
 
 /*
@@ -2715,7 +2715,7 @@ nfs_strategy(void *v)
 	 * queue the request, wake it up and wait for completion
 	 * otherwise just do it ourselves.
 	 */
-	if ((bp->b_flags & B_ASYNC) == 0 || nfs_asyncio(bp))
+	if ((bp->b_flags & B_ASYNC) == 0 || nfs_asyncio(bp, 0))
 		error = nfs_doio(bp, p);
 	return (error);
 }