Fix version fallback for unmount.

Previously, if the mtab record didn't mention a version, unmount
would assume a v3 umount and send an UNMOUNT request accordingly.
This is wrong.

So remove the 'v3' assumption, and allow probe_port to continue when
it gets a version number mis-match.

Also there was some overloading of the meaning of pm_vers==0 relating
to v4 mounts.  As do_nfs_umount is never called for v4, rename it to
do_nfs_umount23, and remove v4 handling from there and from
nfs_call_umount.

Signed-off-by: Neil Brown <neilb@suse.de>

2 files changed, 16 insertions, 28 deletions

diff --git a/utils/mount/network.c b/utils/mount/network.c
index 49d3c6b..63d5f5a 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -408,7 +408,8 @@ static int probe_port(clnt_addr_t *server, const unsigned long *versions,
 					goto out_bad;
 			}
 		}
-		if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED)
+		if (rpc_createerr.cf_stat != RPC_PROGNOTREGISTERED &&
+		    rpc_createerr.cf_stat != RPC_PROGVERSMISMATCH)
 			goto out_bad;
 
 		if (!prot) {
@@ -585,27 +586,16 @@ int nfs_call_umount(clnt_addr_t *mnt_server, dirpath *argp)
 	enum clnt_stat res = 0;
 	int msock;
 
-	switch (mnt_server->pmap.pm_vers) {
-	case 3:
-	case 2:
-	case 1:
-		if (!probe_mntport(mnt_server))
-			return 0;
-		clnt = mnt_openclnt(mnt_server, &msock);
-		if (!clnt)
-			return 0;
-		res = clnt_call(clnt, MOUNTPROC_UMNT,
-				(xdrproc_t)xdr_dirpath, (caddr_t)argp,
-				(xdrproc_t)xdr_void, NULL,
-				TIMEOUT);
-		mnt_closeclnt(clnt, msock);
-		if (res == RPC_SUCCESS)
-			return 1;
-		break;
-	default:
-		res = RPC_SUCCESS;
-		break;
-	}
+	if (!probe_mntport(mnt_server))
+		return 0;
+	clnt = mnt_openclnt(mnt_server, &msock);
+	if (!clnt)
+		return 0;
+	res = clnt_call(clnt, MOUNTPROC_UMNT,
+			(xdrproc_t)xdr_dirpath, (caddr_t)argp,
+			(xdrproc_t)xdr_void, NULL,
+			TIMEOUT);
+	mnt_closeclnt(clnt, msock);
 
 	if (res == RPC_SUCCESS)
 		return 1;
diff --git a/utils/mount/nfsumount.c b/utils/mount/nfsumount.c
index 9e9cd16..285273b 100644
--- a/utils/mount/nfsumount.c
+++ b/utils/mount/nfsumount.c
@@ -142,7 +142,7 @@ static int del_mtab(const char *spec, const char *node)
  * We will need this information to get through the firewall again
  * to do the umount.
  */
-static int do_nfs_umount(const char *spec, char *opts)
+static int do_nfs_umount23(const char *spec, char *opts)
 {
 	char *hostname;
 	char *dirname;
@@ -190,7 +190,7 @@ static int do_nfs_umount(const char *spec, char *opts)
 	}
 
 	pmap->pm_prog = MOUNTPROG;
-	pmap->pm_vers = MOUNTVERS_NFSV3;
+	pmap->pm_vers = 0; /* unknown */
 	if (opts && (p = strstr(opts, "mountprog=")) && isdigit(*(p+10)))
 		pmap->pm_prog = atoi(p+10);
 	if (opts && (p = strstr(opts, "mountport=")) && isdigit(*(p+10)))
@@ -199,8 +199,6 @@ static int do_nfs_umount(const char *spec, char *opts)
 		pmap->pm_vers = nfsvers_to_mnt(2);
 	if (opts && hasmntopt(&mnt, "v3"))
 		pmap->pm_vers = nfsvers_to_mnt(3);
-	if (opts && hasmntopt(&mnt, "v4"))
-		pmap->pm_vers = nfsvers_to_mnt(4);
 	if (opts && (p = strstr(opts, "vers=")) && isdigit(*(p+5)))
 		pmap->pm_vers = nfsvers_to_mnt(atoi(p+5));
 	if (opts && (p = strstr(opts, "mountvers=")) && isdigit(*(p+10)))
@@ -349,11 +347,11 @@ int nfsumount(int argc, char *argv[])
 	ret = 0;
 	if (mc) {
 		if (!lazy && strcmp(mc->m.mnt_type, "nfs4") != 0)
-			ret = do_nfs_umount(mc->m.mnt_fsname, mc->m.mnt_opts);
+			ret = do_nfs_umount23(mc->m.mnt_fsname, mc->m.mnt_opts);
 		ret = del_mtab(mc->m.mnt_fsname, mc->m.mnt_dir) ?: ret;
 	} else if (*spec != '/') {
 		if (!lazy)
-			ret = do_nfs_umount(spec, "tcp,v3");
+			ret = do_nfs_umount23(spec, "tcp,v3");
 	} else
 		ret = del_mtab(NULL, spec);