This patch implements scsi_eh_schedule_host() which provides a way to
directly invoke SCSI EH without SCSI command from drivers implementing
->eh_strategy_handler. This allows such drivers to use EH to handle
exception conditions which are not associated with particular SCSI
command.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
Jeff, I think using separate variable (->host_eh_scheduled) is the
simplest way to implement this. Adding more semantics to ->host_busy
and failed doesn't sound very attractive to me.
drivers/scsi/scsi_error.c | 38 +++++++++++++++++++++++++++++++++++++-
include/scsi/scsi_eh.h | 1 +
include/scsi/scsi_host.h | 1 +
3 files changed, 39 insertions(+), 1 deletions(-)
544d293f756e7041f676ac30152445339111a9c8
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index c314095..bc8a253 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -114,6 +114,42 @@ int scsi_eh_schedule_cmd(struct scsi_cmn
EXPORT_SYMBOL_GPL(scsi_eh_schedule_cmd);
/**
+ * scsi_eh_schedule_host - schedule scsi host for error handling
+ * @shost: SCSI host to invoke error handling on.
+ *
+ * Description:
+ * This function is used by LLDDs which don't use standard SCSI
+ * EH to schedule @shost for EH. This allows such LLDDs to use
+ * EH for handling exceptions not associated with command.
+ *
+ * Return value:
+ * 0 on failure.
+ **/
+int scsi_eh_schedule_host(struct Scsi_Host *shost)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ WARN_ON(!shost->hostt->eh_strategy_handler);
+
+ if (!shost->ehandler)
+ return 0;
+
+ spin_lock_irqsave(shost->host_lock, flags);
+ if (scsi_host_set_state(shost, SHOST_RECOVERY))
+ if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY))
+ goto out_unlock;
+
+ ret = 1;
+ shost->host_eh_scheduled++;
+ scsi_eh_wakeup(shost);
+ out_unlock:
+ spin_unlock_irqrestore(shost->host_lock, flags);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(scsi_eh_schedule_host);
+
+/**
* scsi_add_timer - Start timeout timer for a single scsi command.
* @scmd: scsi command that is about to start running.
* @timeout: amount of time to allow this command to run.
@@ -1541,7 +1577,7 @@ int scsi_error_handler(void *data)
*/
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
- if (shost->host_failed == 0 ||
+ if ((shost->host_failed == 0 && shost->host_eh_scheduled == 0) ||
shost->host_failed != shost->host_busy) {
SCSI_LOG_ERROR_RECOVERY(1,
printk("Error handler scsi_eh_%d sleeping\n",
diff --git a/include/scsi/scsi_eh.h b/include/scsi/scsi_eh.h
index dd0a50e..b1c09f4 100644
--- a/include/scsi/scsi_eh.h
+++ b/include/scsi/scsi_eh.h
@@ -36,6 +36,7 @@ static inline int scsi_sense_valid(struc
extern int scsi_eh_schedule_cmd(struct scsi_cmnd *scmd);
+extern int scsi_eh_schedule_host(struct Scsi_Host *shost);
extern void scsi_eh_finish_cmd(struct scsi_cmnd *scmd,
struct list_head *done_q);
extern void scsi_eh_flush_done_q(struct list_head *done_q);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index dc6862d..a991b9c 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -473,6 +473,7 @@ struct Scsi_Host {
*/
unsigned int host_busy; /* commands actually active on low-level */
unsigned int host_failed; /* commands that failed. */
+ unsigned int host_eh_scheduled; /* EH scheduled without command */
unsigned short host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
int resetting; /* if set, it means that last_reset is a valid value */
--
1.2.4
-
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