NFSv4.1: Fix the CREATE_SESSION slot number accounting

commit b519d408ea32040b1c7e10b155a3ee9a36660947 upstream.

Ensure that we conform to the algorithm described in RFC5661, section
18.36.4 for when to bump the sequence id. In essence we do it for all
cases except when the RPC call timed out, or in case of the server returning
NFS4ERR_DELAY or NFS4ERR_STALE_CLIENTID.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
[bwh: Backported to 3.16:
 - Add the 'out' label
 - Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 7dc0bf73e76afe80c438949b2ddced310ee3ac2a..1522ec81c26f5fa09511146918a29a3cdd23d9a7 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -7063,13 +7063,22 @@ static int _nfs4_proc_create_session(struct nfs_client *clp,
        status = rpc_call_sync(session->clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
        trace_nfs4_create_session(clp, status);
 
+       switch (status) {
+       case -NFS4ERR_STALE_CLIENTID:
+       case -NFS4ERR_DELAY:
+       case -ETIMEDOUT:
+       case -EACCES:
+       case -EAGAIN:
+               goto out;
+       };
+
+       clp->cl_seqid++;
        if (!status) {
                /* Verify the session's negotiated channel_attrs values */
                status = nfs4_verify_channel_attrs(&args, session);
-               /* Increment the clientid slot sequence id */
-               clp->cl_seqid++;
        }
 
+out:
        return status;
 }