[PATCH] SCSI: make scsi_implement_eh() generic API for SCSI transports

libata implemented a feature to schedule EH without an associated EH
by manipulating shost->host_eh_scheduled in ata_scsi_schedule_eh()
directly.  Move this function to scsi_error.c and rename it to
scsi_schedule_eh().  It is now an exported API for SCSI transports and
exported via new header file drivers/scsi/scsi_transport_api.h

This patch also de-export scsi_eh_wakeup() which was exported
specifically for ata_scsi_schedule_eh().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 22 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 9ca71cbefce0..346ab72ebf86 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -56,7 +56,28 @@ void scsi_eh_wakeup(struct Scsi_Host *shost)
                                 printk("Waking error handler thread\n"));
         }
 }
-EXPORT_SYMBOL_GPL(scsi_eh_wakeup);
+
+/**
+ * scsi_schedule_eh - schedule EH for SCSI host
+ * @shost:      SCSI host to invoke error handling on.
+ *
+ * Schedule SCSI EH without scmd.
+ **/
+void scsi_schedule_eh(struct Scsi_Host *shost)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(shost->host_lock, flags);
+
+        if (scsi_host_set_state(shost, SHOST_RECOVERY) == 0 ||
+            scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY) == 0) {
+                shost->host_eh_scheduled++;
+                scsi_eh_wakeup(shost);
+        }
+
+        spin_unlock_irqrestore(shost->host_lock, flags);
+}
+EXPORT_SYMBOL_GPL(scsi_schedule_eh);
 
 /**
  * scsi_eh_scmd_add - add scsi cmd to error handling.