nfsd4: introduce nfs4_client.cl_refcount

Currently just initialize the cl_refcount to 1
and decrement in expire_client(), conditionally freeing the
client when the refcount reaches 0.

To be used later by nfsv4.1 compounds to keep the client from
timing out while in use.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

2 files changed, 5 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index dede43c37336..e439a882e0c2 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -740,8 +740,9 @@ expire_client(struct nfs4_client *clp)
         list_del(&clp->cl_strhash);
         spin_lock(&client_lock);
         unhash_client_locked(clp);
+        if (atomic_read(&clp->cl_refcount) == 0)
+                free_client(clp);
         spin_unlock(&client_lock);
-        free_client(clp);
 }
 
 static void copy_verf(struct nfs4_client *target, nfs4_verifier *source)
@@ -827,6 +828,7 @@ static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
         }
 
         memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
+        atomic_set(&clp->cl_refcount, 0);
         atomic_set(&clp->cl_cb_set, 0);
         INIT_LIST_HEAD(&clp->cl_idhash);
         INIT_LIST_HEAD(&clp->cl_strhash);
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 98836fd87f69..ee42a0beecfa 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -233,6 +233,8 @@ struct nfs4_client {
         struct nfsd4_clid_slot  cl_cs_slot;     /* create_session slot */
         u32                     cl_exchange_flags;
         struct nfs4_sessionid   cl_sessionid;
+        /* number of rpc's in progress over an associated session: */
+        atomic_t                cl_refcount;
 
         /* for nfs41 callbacks */
         /* We currently support a single back channel with a single slot */