nfs41: Adjust max cache response size value

For the CREATE_SESSION attribute ca_maxresponsesize_cached, calculate
the value based on the rpc reply header size plus the maximum nfs compound
reply size.

Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e437fd6a819f..020ebf151184 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1578,6 +1578,14 @@ static void encode_create_session(struct xdr_stream *xdr,
         char machine_name[NFS4_MAX_MACHINE_NAME_LEN];
         uint32_t len;
         struct nfs_client *clp = args->client;
+        u32 max_resp_sz_cached;
+
+        /*
+         * Assumes OPEN is the biggest non-idempotent compound.
+         * 2 is the verifier.
+         */
+        max_resp_sz_cached = (NFS4_dec_open_sz + RPC_REPHDRSIZE +
+                              RPC_MAX_AUTH_SIZE + 2) * XDR_UNIT;
 
         len = scnprintf(machine_name, sizeof(machine_name), "%s",
                         clp->cl_ipaddr);
@@ -1592,7 +1600,7 @@ static void encode_create_session(struct xdr_stream *xdr,
         *p++ = cpu_to_be32(args->fc_attrs.headerpadsz); /* header padding size */
         *p++ = cpu_to_be32(args->fc_attrs.max_rqst_sz); /* max req size */
         *p++ = cpu_to_be32(args->fc_attrs.max_resp_sz); /* max resp size */
-        *p++ = cpu_to_be32(args->fc_attrs.max_resp_sz_cached);  /* Max resp sz cached */
+        *p++ = cpu_to_be32(max_resp_sz_cached);         /* Max resp sz cached */
         *p++ = cpu_to_be32(args->fc_attrs.max_ops);     /* max operations */
         *p++ = cpu_to_be32(args->fc_attrs.max_reqs);    /* max requests */
         *p++ = cpu_to_be32(0);                          /* rdmachannel_attrs */