nfsd: fix configuration of supported minor versions

When the user turns off all minor versions of NFSv4, that should be
equivalent to turning off NFSv4 support, so a mount attempt using NFSv4
should get RPC_PROG_MISMATCH, not NFSERR_MINOR_VERS_MISMATCH.

Allow the user to use either '4.0' or '4' to enable or disable minor
version 0.  Other minor versions are still enabled or disabled using the
'4.x' format.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 2e378d0479ad..efd66da99201 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -153,6 +153,18 @@ int nfsd_vers(int vers, enum vers_op change)
         return 0;
 }
 
+static void
+nfsd_adjust_nfsd_versions4(void)
+{
+        unsigned i;
+
+        for (i = 0; i <= NFSD_SUPPORTED_MINOR_VERSION; i++) {
+                if (nfsd_supported_minorversions[i])
+                        return;
+        }
+        nfsd_vers(4, NFSD_CLEAR);
+}
+
 int nfsd_minorversion(u32 minorversion, enum vers_op change)
 {
         if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
@@ -160,9 +172,11 @@ int nfsd_minorversion(u32 minorversion, enum vers_op change)
         switch(change) {
         case NFSD_SET:
                 nfsd_supported_minorversions[minorversion] = true;
+                nfsd_vers(4, NFSD_SET);
                 break;
         case NFSD_CLEAR:
                 nfsd_supported_minorversions[minorversion] = false;
+                nfsd_adjust_nfsd_versions4();
                 break;
         case NFSD_TEST:
                 return nfsd_supported_minorversions[minorversion];