GIT: unionfs2-2.6.27.y: NFSD: don't report compiled-out versions as present

[Erez Zadok]

commit b9cb946fac3288e7a35571525ef09946e2ba6d7f
Author: Pavel Emelyanov <xemul at openvz.org>
Date:   Fri May 14 15:33:36 2010 +0400

    NFSD: don't report compiled-out versions as present
    
    commit 15ddb4aec54422ead137b03ea4e9b3f5db3f7cc2 upstream.
    
    The /proc/fs/nfsd/versions file calls nfsd_vers() to check whether
    the particular nfsd version is present/available. The problem is
    that once I turn off e.g. NFSD-V4 this call returns -1 which is
    true from the callers POV which is wrong.
    
    The proposal is to report false in that case.
    
    The bug has existed since 6658d3a7bbfd1768 "[PATCH] knfsd: remove
    nfsd_versbits as intermediate storage for desired versions".
    
    Signed-off-by: Pavel Emelyanov <xemul at openvz.org>
    Acked-by: NeilBrown <neilb at suse.de>
    Signed-off-by: J. Bruce Fields <bfields at citi.umich.edu>
    Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 80292ff..e02db8e 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -126,7 +126,7 @@ struct svc_program		nfsd_program = {
 int nfsd_vers(int vers, enum vers_op change)
 {
 	if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
-		return -1;
+		return 0;
 	switch(change) {
 	case NFSD_SET:
 		nfsd_versions[vers] = nfsd_version[vers];