From dk@GENESYSLAB.COM Mon Nov 24 02:35:46 1997
Date: Wed, 5 Nov 1997 21:34:00 -0800
From: "Dmitry Kohmanyuk [KOI8-R] Дмитрий Кохманюк" 
To: BUGTRAQ@NETSPACE.ORG
Subject: netapp NFS server crash by FreeBSD client [w/patch]

this is only relevant to those using NetApp NFS file servers.

background:

there are 2 versions of NFS in town, v2 and v3.  In v3, one of
things introduced was ability to read names of files in directory
with stat(2)ing them at the same time;  the procedure name is
readdirplus.  It can be used to speed up programs like ls(1).

Apparently, NFS code in FreeBSD 2.2 (derived from 4.4BSD code, so
perhaps this applies to all of modern BSD systems here) allow client
to specify this in mount options without using NFS v3.

This meaningless set of options panics NetApp file server.

the following simple patch (attached) for
/usr/src/sys/nfs/nfs_bio.c
fixes this problem.


  [ Part 2: "Attached Text" ]

--- nfs_bio.c.ok        Wed Nov  5 20:11:17 1997
+++ nfs_bio.c   Wed Nov  5 20:14:06 1997
@@ -1031,6 +1031,8 @@
            case VDIR:
                nfsstats.readdir_bios++;
                uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
+               if (!(nmp->nm_flag & NFSMNT_NFSV3))
+                       nmp->nm_flag &= ~NFSMNT_RDIRPLUS;       /* dk@farm.org */
                if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
                        error = nfs_readdirplusrpc(vp, uiop, cr);
                        if (error == NFSERR_NOTSUPP)