nfs41: Don't clear DRAINING flag on NFS4ERR_STALE_CLIENTID

If CREATE_SESSION fails with NFS4ERR_STALE_CLIENTID, don't clear the
NFS4CLNT_SESSION_DRAINING flag and don't wake RPCs waiting for the
session to be reestablished.  We don't have a session yet, so there
is no reason to wake other RPCs.

This avoids sending spurious compounds with bogus sequenceID during
session and state recovery.

Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
[Trond.Myklebust@netapp.com: cleaned up patch by adding the
                             nfs41_begin/end_drain_session() helpers]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 43 insertions, 18 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 4be036942569..fbae2c94dbc6 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4586,10 +4586,12 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
         init_completion(&session->complete);
 
         tbl = &session->fc_slot_table;
+        tbl->highest_used_slotid = -1;
         spin_lock_init(&tbl->slot_tbl_lock);
         rpc_init_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
 
         tbl = &session->bc_slot_table;
+        tbl->highest_used_slotid = -1;
         spin_lock_init(&tbl->slot_tbl_lock);
         rpc_init_wait_queue(&tbl->slot_tbl_waitq, "BackChannel Slot table");
 
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 9cfe6864d9ed..1b629cca7072 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -135,16 +135,43 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
         return status;
 }
 
+static void nfs41_end_drain_session(struct nfs_client *clp,
+                struct nfs4_session *ses)
+{
+        if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state))
+                rpc_wake_up(&ses->fc_slot_table.slot_tbl_waitq);
+}
+
+static int nfs41_begin_drain_session(struct nfs_client *clp,
+                struct nfs4_session *ses)
+{
+        struct nfs4_slot_table *tbl = &ses->fc_slot_table;
+
+        spin_lock(&tbl->slot_tbl_lock);
+        set_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state);
+        if (tbl->highest_used_slotid != -1) {
+                INIT_COMPLETION(ses->complete);
+                spin_unlock(&tbl->slot_tbl_lock);
+                return wait_for_completion_interruptible(&ses->complete);
+        }
+        spin_unlock(&tbl->slot_tbl_lock);
+        return 0;
+}
+
 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 {
         int status;
 
+        status = nfs41_begin_drain_session(clp, clp->cl_session);
+        if (status != 0)
+                goto out;
         status = nfs4_proc_exchange_id(clp, cred);
         if (status != 0)
                 goto out;
         status = nfs4_proc_create_session(clp);
         if (status != 0)
                 goto out;
+        nfs41_end_drain_session(clp, clp->cl_session);
         nfs41_setup_state_renewal(clp);
         nfs_mark_client_ready(clp, NFS_CS_READY);
 out:
@@ -1239,20 +1266,11 @@ static void nfs4_session_recovery_handle_error(struct nfs_client *clp, int err)
 static int nfs4_reset_session(struct nfs_client *clp)
 {
         struct nfs4_session *ses = clp->cl_session;
-        struct nfs4_slot_table *tbl = &ses->fc_slot_table;
         int status;
 
-        spin_lock(&tbl->slot_tbl_lock);
-        set_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state);
-        if (tbl->highest_used_slotid != -1) {
-                INIT_COMPLETION(ses->complete);
-                spin_unlock(&tbl->slot_tbl_lock);
-                status = wait_for_completion_interruptible(&ses->complete);
-                if (status) /* -ERESTARTSYS */
-                        goto out;
-        } else {
-                spin_unlock(&tbl->slot_tbl_lock);
-        }
+        status = nfs41_begin_drain_session(clp, ses);
+        if (status != 0)
+                return status;
 
         status = nfs4_proc_destroy_session(clp->cl_session);
         if (status && status != -NFS4ERR_BADSESSION &&
@@ -1265,13 +1283,18 @@ static int nfs4_reset_session(struct nfs_client *clp)
         status = nfs4_proc_create_session(clp);
         if (status)
                 nfs4_session_recovery_handle_error(clp, status);
-                /* fall through*/
+
 out:
-        /* Wake up the next rpc task even on error */
-        clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state);
-        rpc_wake_up(&clp->cl_session->fc_slot_table.slot_tbl_waitq);
-        if (status == 0)
-                nfs41_setup_state_renewal(clp);
+        /*
+         * Let the state manager reestablish state
+         * without waking other tasks yet.
+         */
+        if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
+                /* Wake up the next rpc task */
+                nfs41_end_drain_session(clp, ses);
+                if (status == 0)
+                        nfs41_setup_state_renewal(clp);
+        }
         return status;
 }