If NFSv4, in general, is requested (possibly by -t nfs4 or -o v4 or -o
vers=4 etc) then we need to negotiate the best minor version, but must
not fallback to v3 or v2. Internally, this state is reflected in v_mode
== V_GENERAL. This means that a major version was given, but the minor
version still needs to be negotiated.
This is handled by nfs_autonegotiate(). It currently does the right
thing for EPROTONOSUPPORT and EINVAL, but not for other errors.
In particular, ENOENT can cause problems as NFSv4 might export
a different namespace than NFSv3 (e.g. by using fsid=0 in the Linux
NFS server). Currently a mount request for NFSv4 and a particular path
can result if an NFSv3 mount if the path is available with v3 but
not v4.
So move the special handling of V_GENERAL into the common fall_back:
code, and add extra checking in the ENCONNREFUSED case, which does
not use fall_back:.
Tested-by: Steve Dickson <steved@xxxxxxxxxx>
Signed-off-by: NeilBrown <neilb@xxxxxxxx>
---
utils/mount/stropts.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index 0fbb37569ef9..b20ad1c8bf55 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -838,9 +838,6 @@ check_result:
case EINVAL:
/* A less clear indication that our client
* does not support NFSv4 minor version. */
- if (mi->version.v_mode == V_GENERAL &&
- mi->version.minor == 0)
- return result;
if (mi->version.v_mode != V_SPECIFIC) {
if (mi->version.minor > 0) {
mi->version.minor--;
@@ -862,6 +859,9 @@ check_result:
/* UDP-Only servers won't support v4, but maybe it
* just isn't ready yet. So try v3, but double-check
* with rpcbind for v4. */
+ if (mi->version.v_mode == V_GENERAL)
+ /* Mustn't try v2,v3 */
+ return result;
result = nfs_try_mount_v3v2(mi, TRUE);
if (result == 0 && errno == EAGAIN) {
/* v4 server seems to be registered now. */
@@ -878,6 +878,9 @@ check_result:
}
fall_back:
+ if (mi->version.v_mode == V_GENERAL)
+ /* v2,3 fallback not allowed */
+ return result;
return nfs_try_mount_v3v2(mi, FALSE);
}
--
2.12.2
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