NFSv4.1: Don't set up a backchannel if the server didn't agree to do so

If the server doesn't agree to out backchannel setup request, then
don't set one up.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index e36a9d78ea49adc63329253a0a94cb22d6be933a..197806fb87ffb459c19f3c4bbc8da50c58c870dc 100644 (file)
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -427,6 +427,8 @@ __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
        if (clp == NULL)
                goto out;
 
+       if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
+               goto out;
        tbl = &clp->cl_session->bc_slot_table;
 
        spin_lock(&tbl->slot_tbl_lock);

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 006bfa3da55be8d20918fc4e21e4b8e16c111f3f..59853797825c3a79891412e68c60aeb67fcc251f 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7195,6 +7195,8 @@ static int nfs4_verify_back_channel_attrs(struct nfs41_create_session_args *args
        struct nfs4_channel_attrs *sent = &args->bc_attrs;
        struct nfs4_channel_attrs *rcvd = &res->bc_attrs;
 
+       if (!(res->flags & SESSION4_BACK_CHAN))
+               goto out;
        if (rcvd->max_rqst_sz > sent->max_rqst_sz)
                return -EINVAL;
        if (rcvd->max_resp_sz < sent->max_resp_sz)
@@ -7206,6 +7208,7 @@ static int nfs4_verify_back_channel_attrs(struct nfs41_create_session_args *args
                return -EINVAL;
        if (rcvd->max_reqs != sent->max_reqs)
                return -EINVAL;
+out:
        return 0;
 }
 
@@ -7226,7 +7229,9 @@ static void nfs4_update_session(struct nfs4_session *session,
        nfs4_copy_sessionid(&session->sess_id, &res->sessionid);
        session->flags = res->flags;
        memcpy(&session->fc_attrs, &res->fc_attrs, sizeof(session->fc_attrs));
-       memcpy(&session->bc_attrs, &res->bc_attrs, sizeof(session->bc_attrs));
+       if (res->flags & SESSION4_BACK_CHAN)
+               memcpy(&session->bc_attrs, &res->bc_attrs,
+                               sizeof(session->bc_attrs));
 }
 
 static int _nfs4_proc_create_session(struct nfs_client *clp,

diff --git a/fs/nfs/nfs4session.c b/fs/nfs/nfs4session.c
index e799dc3c3b1db9f7681199907bff5e7bffb3f853..e23366effcfb1e43bcb81983bcbaeacf2e512002 100644 (file)
--- a/fs/nfs/nfs4session.c
+++ b/fs/nfs/nfs4session.c
@@ -450,7 +450,7 @@ int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
        tbl = &ses->fc_slot_table;
        tbl->session = ses;
        status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1);
-       if (status) /* -ENOMEM */
+       if (status || !(ses->flags & SESSION4_BACK_CHAN)) /* -ENOMEM */
                return status;
        /* Back channel */
        tbl = &ses->bc_slot_table;