NFS: Prevent another deadlock in nfs_release_page()
[safe/jmp/linux-2.6] / fs / nfs / nfs4state.c
index e76427e..6c5ed51 100644 (file)
@@ -135,16 +135,30 @@ 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)
+static void nfs4_end_drain_session(struct nfs_client *clp)
 {
-       if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state))
-               rpc_wake_up(&ses->fc_slot_table.slot_tbl_waitq);
+       struct nfs4_session *ses = clp->cl_session;
+       int max_slots;
+
+       if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) {
+               spin_lock(&ses->fc_slot_table.slot_tbl_lock);
+               max_slots = ses->fc_slot_table.max_slots;
+               while (max_slots--) {
+                       struct rpc_task *task;
+
+                       task = rpc_wake_up_next(&ses->fc_slot_table.
+                                               slot_tbl_waitq);
+                       if (!task)
+                               break;
+                       rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
+               }
+               spin_unlock(&ses->fc_slot_table.slot_tbl_lock);
+       }
 }
 
-static int nfs41_begin_drain_session(struct nfs_client *clp,
-               struct nfs4_session *ses)
+static int nfs4_begin_drain_session(struct nfs_client *clp)
 {
+       struct nfs4_session *ses = clp->cl_session;
        struct nfs4_slot_table *tbl = &ses->fc_slot_table;
 
        spin_lock(&tbl->slot_tbl_lock);
@@ -162,16 +176,13 @@ 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;
+       nfs4_begin_drain_session(clp);
        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:
@@ -755,16 +766,21 @@ struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
        return new;
 }
 
-void nfs_free_seqid(struct nfs_seqid *seqid)
+void nfs_release_seqid(struct nfs_seqid *seqid)
 {
        if (!list_empty(&seqid->list)) {
                struct rpc_sequence *sequence = seqid->sequence->sequence;
 
                spin_lock(&sequence->lock);
-               list_del(&seqid->list);
+               list_del_init(&seqid->list);
                spin_unlock(&sequence->lock);
                rpc_wake_up(&sequence->wait);
        }
+}
+
+void nfs_free_seqid(struct nfs_seqid *seqid)
+{
+       nfs_release_seqid(seqid);
        kfree(seqid);
 }
 
@@ -885,7 +901,7 @@ void nfs4_schedule_state_recovery(struct nfs_client *clp)
        nfs4_schedule_state_manager(clp);
 }
 
-static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
+int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
 {
 
        set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
@@ -1233,37 +1249,72 @@ static int nfs4_reclaim_lease(struct nfs_client *clp)
 }
 
 #ifdef CONFIG_NFS_V4_1
+void nfs41_handle_recall_slot(struct nfs_client *clp)
+{
+       set_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
+       nfs4_schedule_state_recovery(clp);
+}
+
+static void nfs4_reset_all_state(struct nfs_client *clp)
+{
+       if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
+               clp->cl_boot_time = CURRENT_TIME;
+               nfs4_state_start_reclaim_nograce(clp);
+               nfs4_schedule_state_recovery(clp);
+       }
+}
+
+static void nfs41_handle_server_reboot(struct nfs_client *clp)
+{
+       if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
+               nfs4_state_start_reclaim_reboot(clp);
+               nfs4_schedule_state_recovery(clp);
+       }
+}
+
+static void nfs41_handle_state_revoked(struct nfs_client *clp)
+{
+       /* Temporary */
+       nfs4_reset_all_state(clp);
+}
+
+static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
+{
+       /* This will need to handle layouts too */
+       nfs_expire_all_delegations(clp);
+}
+
+static void nfs41_handle_cb_path_down(struct nfs_client *clp)
+{
+       nfs_expire_all_delegations(clp);
+       if (test_and_set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state) == 0)
+               nfs4_schedule_state_recovery(clp);
+}
+
 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
 {
        if (!flags)
                return;
-       else if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED) {
-               set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
-               nfs4_state_start_reclaim_reboot(clp);
-               nfs4_schedule_state_recovery(clp);
-       } else if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
+       else if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
+               nfs41_handle_server_reboot(clp);
+       else if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED |
                            SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
                            SEQ4_STATUS_ADMIN_STATE_REVOKED |
-                           SEQ4_STATUS_RECALLABLE_STATE_REVOKED |
-                           SEQ4_STATUS_LEASE_MOVED)) {
-               set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
-               nfs4_state_start_reclaim_nograce(clp);
-               nfs4_schedule_state_recovery(clp);
-       } else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
+                           SEQ4_STATUS_LEASE_MOVED))
+               nfs41_handle_state_revoked(clp);
+       else if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
+               nfs41_handle_recallable_state_revoked(clp);
+       else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
                            SEQ4_STATUS_BACKCHANNEL_FAULT |
                            SEQ4_STATUS_CB_PATH_DOWN_SESSION))
-               nfs_expire_all_delegations(clp);
+               nfs41_handle_cb_path_down(clp);
 }
 
 static int nfs4_reset_session(struct nfs_client *clp)
 {
-       struct nfs4_session *ses = clp->cl_session;
        int status;
 
-       status = nfs41_begin_drain_session(clp, ses);
-       if (status != 0)
-               return status;
-
+       nfs4_begin_drain_session(clp);
        status = nfs4_proc_destroy_session(clp->cl_session);
        if (status && status != -NFS4ERR_BADSESSION &&
            status != -NFS4ERR_DEADSESSION) {
@@ -1273,25 +1324,52 @@ static int nfs4_reset_session(struct nfs_client *clp)
 
        memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
        status = nfs4_proc_create_session(clp);
-       if (status)
+       if (status) {
                status = nfs4_recovery_handle_error(clp, status);
+               goto out;
+       }
+       /* create_session negotiated new slot table */
+       clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state);
 
+        /* Let the state manager reestablish state */
+       if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
+               nfs41_setup_state_renewal(clp);
 out:
-       /*
-        * 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;
 }
 
+static int nfs4_recall_slot(struct nfs_client *clp)
+{
+       struct nfs4_slot_table *fc_tbl = &clp->cl_session->fc_slot_table;
+       struct nfs4_channel_attrs *fc_attrs = &clp->cl_session->fc_attrs;
+       struct nfs4_slot *new, *old;
+       int i;
+
+       nfs4_begin_drain_session(clp);
+       new = kmalloc(fc_tbl->target_max_slots * sizeof(struct nfs4_slot),
+                     GFP_KERNEL);
+        if (!new)
+               return -ENOMEM;
+
+       spin_lock(&fc_tbl->slot_tbl_lock);
+       for (i = 0; i < fc_tbl->target_max_slots; i++)
+               new[i].seq_nr = fc_tbl->slots[i].seq_nr;
+       old = fc_tbl->slots;
+       fc_tbl->slots = new;
+       fc_tbl->max_slots = fc_tbl->target_max_slots;
+       fc_tbl->target_max_slots = 0;
+       fc_attrs->max_reqs = fc_tbl->max_slots;
+       spin_unlock(&fc_tbl->slot_tbl_lock);
+
+       kfree(old);
+       nfs4_end_drain_session(clp);
+       return 0;
+}
+
 #else /* CONFIG_NFS_V4_1 */
 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
+static int nfs4_end_drain_session(struct nfs_client *clp) { return 0; }
+static int nfs4_recall_slot(struct nfs_client *clp) { return 0; }
 #endif /* CONFIG_NFS_V4_1 */
 
 /* Set NFS4CLNT_LEASE_EXPIRED for all v4.0 errors and for recoverable errors
@@ -1304,6 +1382,7 @@ static void nfs4_set_lease_expired(struct nfs_client *clp, int status)
                case -NFS4ERR_DELAY:
                case -NFS4ERR_CLID_INUSE:
                case -EAGAIN:
+               case -EKEYEXPIRED:
                        break;
 
                case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
@@ -1382,10 +1461,20 @@ static void nfs4_state_manager(struct nfs_client *clp)
                                goto out_error;
                }
 
+               nfs4_end_drain_session(clp);
                if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
                        nfs_client_return_marked_delegations(clp);
                        continue;
                }
+               /* Recall session slots */
+               if (test_and_clear_bit(NFS4CLNT_RECALL_SLOT, &clp->cl_state)
+                  && nfs4_has_session(clp)) {
+                       status = nfs4_recall_slot(clp);
+                       if (status < 0)
+                               goto out_error;
+                       continue;
+               }
+
 
                nfs4_clear_state_manager_bit(clp);
                /* Did we race with an attempt to give us more work? */
@@ -1398,6 +1487,7 @@ static void nfs4_state_manager(struct nfs_client *clp)
 out_error:
        printk(KERN_WARNING "Error: state manager failed on NFSv4 server %s"
                        " with error %d\n", clp->cl_hostname, -status);
+       nfs4_end_drain_session(clp);
        nfs4_clear_state_manager_bit(clp);
 }