[SCSI] libsas: Handle SCSI commands that complete with failure codes
This patch moves the code that handles SAS failures out of the main EH
function and into a separate function. It also detects commands that have
no sas_task (i.e. they completed, but with error data) and sends them into
scsi_error for processing. This allows us to handle SCSI errors (and
enables auto-spinup as a side effect) instead of dropping them on the
floor and falling into an infinite loop. It also requires the
implementation of a device reset function, which the SAS failure code has
been modified to employ for REQ_DEVICE_RESET.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 9ffe760..eac1d2d 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -34,6 +34,7 @@
#include <scsi/scsi_transport_sas.h>
#include "../scsi_sas_internal.h"
#include "../scsi_transport_api.h"
+#include "../scsi_priv.h"
#include <linux/err.h>
#include <linux/blkdev.h>
@@ -396,54 +397,80 @@
return res;
}
-static int eh_reset_phy_helper(struct sas_phy *phy)
+/* Find the sas_phy that's attached to this device */
+struct sas_phy *find_local_sas_phy(struct domain_device *dev)
{
- int tmf_resp;
+ struct domain_device *pdev = dev->parent;
+ struct ex_phy *exphy = NULL;
+ int i;
- tmf_resp = sas_phy_reset(phy, 1);
- if (tmf_resp)
- SAS_DPRINTK("Hard reset of phy %d failed 0x%x\n",
- phy->identify.phy_identifier,
- tmf_resp);
+ /* Directly attached device */
+ if (!pdev)
+ return dev->port->phy;
- return tmf_resp;
+ /* Otherwise look in the expander */
+ for (i = 0; i < pdev->ex_dev.num_phys; i++)
+ if (!memcmp(dev->sas_addr,
+ pdev->ex_dev.ex_phy[i].attached_sas_addr,
+ SAS_ADDR_SIZE)) {
+ exphy = &pdev->ex_dev.ex_phy[i];
+ break;
+ }
+
+ BUG_ON(!exphy);
+ return exphy->phy;
}
-void sas_scsi_recover_host(struct Scsi_Host *shost)
+/* Attempt to send a target reset message to a device */
+int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
- struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
- unsigned long flags;
- LIST_HEAD(error_q);
+ struct domain_device *dev = cmd_to_domain_dev(cmd);
+ struct sas_phy *phy = find_local_sas_phy(dev);
+ int res;
+
+ res = sas_phy_reset(phy, 1);
+ if (res)
+ SAS_DPRINTK("Device reset of %s failed 0x%x\n",
+ phy->dev.kobj.k_name,
+ res);
+ if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
+ return SUCCESS;
+
+ return FAILED;
+}
+
+/* Try to reset a device */
+static int try_to_reset_cmd_device(struct Scsi_Host *shost,
+ struct scsi_cmnd *cmd)
+{
+ if (!shost->hostt->eh_device_reset_handler)
+ return FAILED;
+
+ return shost->hostt->eh_device_reset_handler(cmd);
+}
+
+static int sas_eh_handle_sas_errors(struct Scsi_Host *shost,
+ struct list_head *work_q,
+ struct list_head *done_q)
+{
struct scsi_cmnd *cmd, *n;
enum task_disposition res = TASK_IS_DONE;
int tmf_resp, need_reset;
struct sas_internal *i = to_sas_internal(shost->transportt);
- struct sas_phy *task_sas_phy = NULL;
+ unsigned long flags;
+ struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
- spin_lock_irqsave(shost->host_lock, flags);
- list_splice_init(&shost->eh_cmd_q, &error_q);
- spin_unlock_irqrestore(shost->host_lock, flags);
-
- SAS_DPRINTK("Enter %s\n", __FUNCTION__);
-
- /* All tasks on this list were marked SAS_TASK_STATE_ABORTED
- * by sas_scsi_timed_out() callback.
- */
Again:
- SAS_DPRINTK("going over list...\n");
- list_for_each_entry_safe(cmd, n, &error_q, eh_entry) {
+ 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);
- if (!task) {
- SAS_DPRINTK("%s: taskless cmd?!\n", __FUNCTION__);
+ if (!task)
continue;
- }
+
+ list_del_init(&cmd->eh_entry);
spin_lock_irqsave(&task->task_state_lock, flags);
need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
- if (need_reset)
- task_sas_phy = task->dev->port->phy;
spin_unlock_irqrestore(&task->task_state_lock, flags);
SAS_DPRINTK("trying to find task 0x%p\n", task);
@@ -457,14 +484,14 @@
task);
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
+ 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);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
+ try_to_reset_cmd_device(shost, cmd);
continue;
case TASK_IS_AT_LU:
SAS_DPRINTK("task 0x%p is at LU: lu recover\n", task);
@@ -476,8 +503,8 @@
cmd->device->lun);
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
- sas_scsi_clear_queue_lu(&error_q, cmd);
+ try_to_reset_cmd_device(shost, cmd);
+ sas_scsi_clear_queue_lu(work_q, cmd);
goto Again;
}
/* fallthrough */
@@ -491,8 +518,8 @@
SAS_ADDR(task->dev->sas_addr));
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
- sas_scsi_clear_queue_I_T(&error_q, task->dev);
+ try_to_reset_cmd_device(shost, cmd);
+ sas_scsi_clear_queue_I_T(work_q, task->dev);
goto Again;
}
/* Hammer time :-) */
@@ -506,8 +533,8 @@
"succeeded\n", port->id);
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
- sas_scsi_clear_queue_port(&error_q,
+ try_to_reset_cmd_device(shost, cmd);
+ sas_scsi_clear_queue_port(work_q,
port);
goto Again;
}
@@ -520,7 +547,7 @@
"succeeded\n");
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
+ try_to_reset_cmd_device(shost, cmd);
goto out;
}
}
@@ -535,21 +562,53 @@
task->task_done(task);
if (need_reset)
- eh_reset_phy_helper(task_sas_phy);
+ try_to_reset_cmd_device(shost, cmd);
goto clear_q;
}
}
out:
- scsi_eh_flush_done_q(&ha->eh_done_q);
- SAS_DPRINTK("--- Exit %s\n", __FUNCTION__);
- return;
+ return list_empty(work_q);
clear_q:
SAS_DPRINTK("--- Exit %s -- clear_q\n", __FUNCTION__);
- list_for_each_entry_safe(cmd, n, &error_q, eh_entry) {
+ 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);
}
+ return list_empty(work_q);
+}
+
+void sas_scsi_recover_host(struct Scsi_Host *shost)
+{
+ struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
+ unsigned long flags;
+ LIST_HEAD(eh_work_q);
+
+ spin_lock_irqsave(shost->host_lock, flags);
+ list_splice_init(&shost->eh_cmd_q, &eh_work_q);
+ spin_unlock_irqrestore(shost->host_lock, flags);
+
+ SAS_DPRINTK("Enter %s\n", __FUNCTION__);
+ /*
+ * Deal with commands that still have SAS tasks (i.e. they didn't
+ * complete via the normal sas_task completion mechanism)
+ */
+ if (sas_eh_handle_sas_errors(shost, &eh_work_q, &ha->eh_done_q))
+ goto out;
+
+ /*
+ * Now deal with SCSI commands that completed ok but have a an error
+ * code (and hopefully sense data) attached. This is roughly what
+ * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
+ * command we see here has no sas_task and is thus unknown to the HA.
+ */
+ if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
+ scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);
+
+out:
+ scsi_eh_flush_done_q(&ha->eh_done_q);
+ SAS_DPRINTK("--- Exit %s\n", __FUNCTION__);
+ return;
}
enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
@@ -914,3 +973,4 @@
EXPORT_SYMBOL_GPL(sas_task_abort);
EXPORT_SYMBOL_GPL(sas_phy_reset);
EXPORT_SYMBOL_GPL(sas_phy_enable);
+EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);