[SCSI] libsas: let libata handle command timeouts
Dan Williams [Tue, 29 Nov 2011 20:08:50 +0000 (12:08 -0800)]
libsas-eh if it successfully aborts an ata command will hide the timeout
condition (AC_ERR_TIMEOUT) from libata.  The command likely completes
with the all-zero task->task_status it started with.  Instead, interpret
a TMF_RESP_FUNC_COMPLETE as the end of the sas_task but keep the scmd
around for libata-eh to handle.

Tested-by: Andrzej Jakowski <andrzej.jakowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/libsas/sas_init.c
drivers/scsi/libsas/sas_scsi_host.c
include/scsi/libsas.h

index 52cd11d..e17fe35 100644 (file)
@@ -146,6 +146,7 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
        }
 
        INIT_LIST_HEAD(&sas_ha->eh_done_q);
+       INIT_LIST_HEAD(&sas_ha->eh_ata_q);
 
        return 0;
 
index 0e3fdba..e02ca3d 100644 (file)
@@ -265,6 +265,22 @@ static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
        scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
 }
 
+static void sas_eh_defer_cmd(struct scsi_cmnd *cmd)
+{
+       struct sas_task *task = TO_SAS_TASK(cmd);
+       struct domain_device *dev = task->dev;
+       struct sas_ha_struct *ha = dev->port->ha;
+
+       if (!dev_is_sata(dev)) {
+               sas_eh_finish_cmd(cmd);
+               return;
+       }
+
+       /* report the timeout to libata */
+       sas_end_task(cmd, task);
+       list_move_tail(&cmd->eh_entry, &ha->eh_ata_q);
+}
+
 static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
 {
        struct scsi_cmnd *cmd, *n;
@@ -562,12 +578,12 @@ Again:
                case TASK_IS_DONE:
                        SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
                                    task);
-                       sas_eh_finish_cmd(cmd);
+                       sas_eh_defer_cmd(cmd);
                        continue;
                case TASK_IS_ABORTED:
                        SAS_DPRINTK("%s: task 0x%p is aborted\n",
                                    __func__, task);
-                       sas_eh_finish_cmd(cmd);
+                       sas_eh_defer_cmd(cmd);
                        continue;
                case TASK_IS_AT_LU:
                        SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
@@ -635,12 +651,14 @@ Again:
                        goto clear_q;
                }
        }
+       list_splice_tail_init(&ha->eh_ata_q, work_q);
        return list_empty(work_q);
 clear_q:
        SAS_DPRINTK("--- Exit %s -- clear_q\n", __func__);
        list_for_each_entry_safe(cmd, n, work_q, eh_entry)
                sas_eh_finish_cmd(cmd);
 
+       list_splice_tail_init(&ha->eh_ata_q, work_q);
        return list_empty(work_q);
 }
 
index aa7192f..6b80310 100644 (file)
@@ -382,7 +382,8 @@ struct sas_ha_struct {
 
        void *lldd_ha;            /* not touched by sas class code */
 
-       struct list_head eh_done_q;
+       struct list_head eh_done_q;  /* complete via scsi_eh_flush_done_q */
+       struct list_head eh_ata_q; /* scmds to promote from sas to ata eh */
 };
 
 #define SHOST_TO_SAS_HA(_shost) (*(struct sas_ha_struct **)(_shost)->hostdata)