Problem to avoid processes getting stuck in "vmopar". From Ian's

mail:

	The problem seems to originate with NFS's postop_attr
	information that is returned with a read or write RPC.
	Within a vm_fault context, the code cannot deal with
	vnode_pager_setsize() shrinking a vnode.

	The workaround in the patch below stops the nfsm_postop_attr()
	macro from ever shrinking a vnode. If the new size in the
	postop_attr information is smaller, then it just sets the
	nfsnode n_attrstamp to 0 to stop the wrong size getting
	used in the future. This change only affects postop_attr
	attributes; the nfsm_loadattr() macro works as normal.

	The change is implemented by adding a new argument to
	nfs_loadattrcache() called 'dontshrink'. When this is
	non-zero, nfs_loadattrcache() will never reduce the
	vnode/nfsnode size; instead it zeros n_attrstamp.

There remain other was processes can get stuck in vmopar.

Submitted by:	Ian Dowse <iedowse@maths.tcd.ie>
Reviewed by:	dillon
Tested by:	Vadim Belman <voland@lflat.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/nfsserver/nfsrvstats.h b/sys/nfsserver/nfsrvstats.h
index e07a4f5..5c5a823 100644
--- a/sys/nfsserver/nfsrvstats.h
+++ b/sys/nfsserver/nfsrvstats.h
@@ -616,7 +616,7 @@ int	nfs_request __P((struct vnode *, struct mbuf *, int, struct proc *,
 			 struct ucred *, struct mbuf **, struct mbuf **,
 			 caddr_t *));
 int	nfs_loadattrcache __P((struct vnode **, struct mbuf **, caddr_t *,
-			       struct vattr *));
+			       struct vattr *, int));
 int	nfs_namei __P((struct nameidata *, fhandle_t *, int,
 		       struct nfssvc_sock *, struct sockaddr *, struct mbuf **,
 		       caddr_t *, struct vnode **, struct proc *, int, int));