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>

1 files changed, 1 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 9d536a8..a9735a6 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));