target: Fix ordered task target_setup_cmd_from_cdb exception hang

[firefly-linux-kernel-4.4.55.git] / drivers / target / target_core_transport.c

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index d151bc3d6971b0204613e64cdb136ad98615d3dd..7f4cdc82234badad8fef971732ad953f745164b4 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1270,23 +1270,6 @@ target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
 
        trace_target_sequencer_start(cmd);
 
-       /*
-        * Check for an existing UNIT ATTENTION condition
-        */
-       ret = target_scsi3_ua_check(cmd);
-       if (ret)
-               return ret;
-
-       ret = target_alua_state_check(cmd);
-       if (ret)
-               return ret;
-
-       ret = target_check_reservation(cmd);
-       if (ret) {
-               cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
-               return ret;
-       }
-
        ret = dev->transport->parse_cdb(cmd);
        if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
                pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
@@ -1749,20 +1732,45 @@ queue_full:
 }
 EXPORT_SYMBOL(transport_generic_request_failure);
 
-void __target_execute_cmd(struct se_cmd *cmd)
+void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
 {
        sense_reason_t ret;
 
-       if (cmd->execute_cmd) {
-               ret = cmd->execute_cmd(cmd);
-               if (ret) {
-                       spin_lock_irq(&cmd->t_state_lock);
-                       cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
-                       spin_unlock_irq(&cmd->t_state_lock);
+       if (!cmd->execute_cmd) {
+               ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+               goto err;
+       }
+       if (do_checks) {
+               /*
+                * Check for an existing UNIT ATTENTION condition after
+                * target_handle_task_attr() has done SAM task attr
+                * checking, and possibly have already defered execution
+                * out to target_restart_delayed_cmds() context.
+                */
+               ret = target_scsi3_ua_check(cmd);
+               if (ret)
+                       goto err;
+
+               ret = target_alua_state_check(cmd);
+               if (ret)
+                       goto err;
 
-                       transport_generic_request_failure(cmd, ret);
+               ret = target_check_reservation(cmd);
+               if (ret) {
+                       cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
+                       goto err;
                }
        }
+
+       ret = cmd->execute_cmd(cmd);
+       if (!ret)
+               return;
+err:
+       spin_lock_irq(&cmd->t_state_lock);
+       cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
+       spin_unlock_irq(&cmd->t_state_lock);
+
+       transport_generic_request_failure(cmd, ret);
 }
 
 static int target_write_prot_action(struct se_cmd *cmd)
@@ -1887,7 +1895,7 @@ void target_execute_cmd(struct se_cmd *cmd)
                return;
        }
 
-       __target_execute_cmd(cmd);
+       __target_execute_cmd(cmd, true);
 }
 EXPORT_SYMBOL(target_execute_cmd);
 
@@ -1911,7 +1919,7 @@ static void target_restart_delayed_cmds(struct se_device *dev)
                list_del(&cmd->se_delayed_node);
                spin_unlock(&dev->delayed_cmd_lock);
 
-               __target_execute_cmd(cmd);
+               __target_execute_cmd(cmd, true);
 
                if (cmd->sam_task_attr == TCM_ORDERED_TAG)
                        break;