[SCSI] libsas: fix error handling

[linux-2.6-omap-h63xx.git] / drivers / scsi / libsas / sas_scsi_host.c

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index f869fba8680721ed8365c0fed872fd4915ed7a84..9c96d1bd36e240221fae332e81116bf1fc8b813b 100644 (file)
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -51,10 +51,14 @@ static void sas_scsi_task_done(struct sas_task *task)
 {
        struct task_status_struct *ts = &task->task_status;
        struct scsi_cmnd *sc = task->uldd_task;
-       struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(sc->device->host);
-       unsigned ts_flags = task->task_state_flags;
        int hs = 0, stat = 0;
 
+       if (unlikely(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
+               /* Aborted tasks will be completed by the error handler */
+               SAS_DPRINTK("task done but aborted\n");
+               return;
+       }
+
        if (unlikely(!sc)) {
                SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
                list_del_init(&task->list);
@@ -120,11 +124,7 @@ static void sas_scsi_task_done(struct sas_task *task)
        sc->result = (hs << 16) | stat;
        list_del_init(&task->list);
        sas_free_task(task);
-       /* This is very ugly but this is how SCSI Core works. */
-       if (ts_flags & SAS_TASK_STATE_ABORTED)
-               scsi_eh_finish_cmd(sc, &sas_ha->eh_done_q);
-       else
-               sc->scsi_done(sc);
+       sc->scsi_done(sc);
 }
 
 static enum task_attribute sas_scsi_get_task_attr(struct scsi_cmnd *cmd)
@@ -255,13 +255,33 @@ out:
        return res;
 }
 
+static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
+{
+       struct sas_task *task = TO_SAS_TASK(cmd);
+       struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
+
+       /* remove the aborted task flag to allow the task to be
+        * completed now. At this point, we only get called following
+        * an actual abort of the task, so we should be guaranteed not
+        * to be racing with any completions from the LLD (hence we
+        * don't need the task state lock to clear the flag) */
+       task->task_state_flags &= ~SAS_TASK_STATE_ABORTED;
+       /* Now call task_done.  However, task will be free'd after
+        * this */
+       task->task_done(task);
+       /* now finish the command and move it on to the error
+        * handler done list, this also takes it off the
+        * error handler pending list */
+       scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
+}
+
 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
 {
        struct scsi_cmnd *cmd, *n;
 
        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
                if (cmd == my_cmd)
-                       list_del_init(&cmd->eh_entry);
+                       sas_eh_finish_cmd(cmd);
        }
 }
 
@@ -274,7 +294,7 @@ static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
                struct domain_device *x = cmd_to_domain_dev(cmd);
 
                if (x == dev)
-                       list_del_init(&cmd->eh_entry);
+                       sas_eh_finish_cmd(cmd);
        }
 }
 
@@ -288,7 +308,7 @@ static void sas_scsi_clear_queue_port(struct list_head *error_q,
                struct asd_sas_port *x = dev->port;
 
                if (x == port)
-                       list_del_init(&cmd->eh_entry);
+                       sas_eh_finish_cmd(cmd);
        }
 }
 
@@ -528,14 +548,14 @@ Again:
                case TASK_IS_DONE:
                        SAS_DPRINTK("%s: task 0x%p is done\n", __FUNCTION__,
                                    task);
-                       task->task_done(task);
+                       sas_eh_finish_cmd(cmd);
                        if (need_reset)
                                try_to_reset_cmd_device(shost, cmd);
                        continue;
                case TASK_IS_ABORTED:
                        SAS_DPRINTK("%s: task 0x%p is aborted\n",
                                    __FUNCTION__, task);
-                       task->task_done(task);
+                       sas_eh_finish_cmd(cmd);
                        if (need_reset)
                                try_to_reset_cmd_device(shost, cmd);
                        continue;
@@ -547,7 +567,7 @@ Again:
                                            "recovered\n",
                                            SAS_ADDR(task->dev),
                                            cmd->device->lun);
-                               task->task_done(task);
+                               sas_eh_finish_cmd(cmd);
                                if (need_reset)
                                        try_to_reset_cmd_device(shost, cmd);
                                sas_scsi_clear_queue_lu(work_q, cmd);
@@ -562,7 +582,7 @@ Again:
                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
                                SAS_DPRINTK("I_T %016llx recovered\n",
                                            SAS_ADDR(task->dev->sas_addr));
-                               task->task_done(task);
+                               sas_eh_finish_cmd(cmd);
                                if (need_reset)
                                        try_to_reset_cmd_device(shost, cmd);
                                sas_scsi_clear_queue_I_T(work_q, task->dev);
@@ -577,7 +597,7 @@ Again:
                                if (res == TMF_RESP_FUNC_COMPLETE) {
                                        SAS_DPRINTK("clear nexus port:%d "
                                                    "succeeded\n", port->id);
-                                       task->task_done(task);
+                                       sas_eh_finish_cmd(cmd);
                                        if (need_reset)
                                                try_to_reset_cmd_device(shost, cmd);
                                        sas_scsi_clear_queue_port(work_q,
@@ -591,10 +611,10 @@ Again:
                                if (res == TMF_RESP_FUNC_COMPLETE) {
                                        SAS_DPRINTK("clear nexus ha "
                                                    "succeeded\n");
-                                       task->task_done(task);
+                                       sas_eh_finish_cmd(cmd);
                                        if (need_reset)
                                                try_to_reset_cmd_device(shost, cmd);
-                                       goto out;
+                                       goto clear_q;
                                }
                        }
                        /* If we are here -- this means that no amount
@@ -606,21 +626,18 @@ Again:
                                    SAS_ADDR(task->dev->sas_addr),
                                    cmd->device->lun);
 
-                       task->task_done(task);
+                       sas_eh_finish_cmd(cmd);
                        if (need_reset)
                                try_to_reset_cmd_device(shost, cmd);
                        goto clear_q;
                }
        }
-out:
        return list_empty(work_q);
 clear_q:
        SAS_DPRINTK("--- Exit %s -- clear_q\n", __FUNCTION__);
-       list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
-               struct sas_task *task = TO_SAS_TASK(cmd);
-               list_del_init(&cmd->eh_entry);
-               task->task_done(task);
-       }
+       list_for_each_entry_safe(cmd, n, work_q, eh_entry)
+               sas_eh_finish_cmd(cmd);
+
        return list_empty(work_q);
 }