| Message ID | 87lgpceeuo.fsf@notabene.neil.brown.name (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 05/31/2017 08:22 PM, NeilBrown wrote: > > 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@redhat.com> > Signed-off-by: NeilBrown <neilb@suse.com> Committed... with the addition change to nfs_set_version() which stops -t nfs4 from rolling back to v3. Thanks! steved. > --- > 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); > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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); }