nfsd4: probe callback channel only once

Our callback code doesn't actually handle concurrent attempts to probe
the callback channel.  Some rethinking of the locking may be required.
However, we can also just move the callback probing to this case.  Since
this is the only time a client is "confirmed" (and since that can only
happen once in the lifetime of a client), this ensures we only probe
once.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

2 files changed, 2 insertions, 4 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 9d536a8cb379..a9735a672963 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -395,8 +395,7 @@ nfsd4_probe_callback(struct nfs4_client *clp)
         };
         struct task_struct *t;
 
-        if (atomic_read(&cb->cb_set))
-                return;
+        BUG_ON(atomic_read(&clp->cl_callback.cb_set));
 
         /* Initialize address */
         memset(&addr, 0, sizeof(addr));
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 31673cd251c3..9d81c7117ae6 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -948,6 +948,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                         }
                         move_to_confirmed(unconf);
                         conf = unconf;
+                        nfsd4_probe_callback(conf);
                         status = nfs_ok;
                 }
         } else if ((!conf || (conf && !same_verf(&conf->cl_confirm, &confirm)))
@@ -965,8 +966,6 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
                 status = nfserr_clid_inuse;
         }
 out:
-        if (!status)
-                nfsd4_probe_callback(conf);
         nfs4_unlock_state();
         return status;
 }