NFS: added FREE_STATEID call

FREE_STATEID is used to tell the server that we want to free a stateid
that no longer has any locks associated with it.  This allows the client
to reclaim locks without encountering edge conditions documented in
section 8.4.3 of RFC 5661.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5612ba997db7..197ad0a737f6 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6043,6 +6043,36 @@ static int nfs41_test_stateid(struct nfs_server *server, struct nfs4_state *stat
         } while (exception.retry);
         return err;
 }
+
+static int _nfs4_free_stateid(struct nfs_server *server, struct nfs4_state *state)
+{
+        int status;
+        struct nfs41_free_stateid_args args = {
+                .stateid = &state->stateid,
+        };
+        struct nfs41_free_stateid_res res;
+        struct rpc_message msg = {
+                .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_FREE_STATEID],
+                .rpc_argp = &args,
+                .rpc_resp = &res,
+        };
+
+        args.seq_args.sa_session = res.seq_res.sr_session = NULL;
+        status = nfs4_call_sync_sequence(server->client, server, &msg, &args.seq_args, &res.seq_res, 0, 1);
+        return status;
+}
+
+static int nfs41_free_stateid(struct nfs_server *server, struct nfs4_state *state)
+{
+        struct nfs4_exception exception = { };
+        int err;
+        do {
+                err = nfs4_handle_exception(server,
+                                _nfs4_free_stateid(server, state),
+                                &exception);
+        } while (exception.retry);
+        return err;
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 struct nfs4_state_recovery_ops nfs40_reboot_recovery_ops = {