[PATCH 1/2] Fix uninitialised variable usage in nfs_options2pmap

[NeilBrown <neilb@suse.com>]

From: Andreas Schwab <schwab@suse.com>

Commit 5bea22e33b7a introduced a regression.  Prior to that commit
nfs_nfs_version would set *version to 0 if NFS version wasn't specified.
Since that commit, version.v_mode is set to V_DEFAULT if the NFS version
isn't specified, but nfs_options2pmap uses version.major without checking
v_mode.  This can lead to incorrect behaviour.
In particular fall-ack to v3 if server doesn't support v4 can fail.

So test v_mode before using version.major.

URL: https://bugzilla.opensuse.org/show_bug.cgi?id=956743
Fixes: 5bea22e33b7a ("mount.nfs: Add struct nfs_version and generalize version parsing")
Signed-off-by: NeilBrown <neilb@suse.com>
---
 utils/mount/network.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/utils/mount/network.c b/utils/mount/network.c
index ebc39d361e2c..8a9bf1476d51 100644
--- a/utils/mount/network.c
+++ b/utils/mount/network.c
@@ -1631,7 +1631,10 @@ int nfs_options2pmap(struct mount_options *options,
 		return 0;
 	if (!nfs_nfs_version(options, &version))
 		return 0;
-	nfs_pmap->pm_vers = version.major;
+	if (version.v_mode == V_DEFAULT)
+		nfs_pmap->pm_vers = 0;
+	else
+		nfs_pmap->pm_vers = version.major;
 	if (!nfs_nfs_protocol(options, &nfs_pmap->pm_prot))
 		return 0;
 	if (!nfs_nfs_port(options, &nfs_pmap->pm_port))