[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>

drivers/scsi/libata-eh.c

@@ -39,6 +39,7 @@
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_cmnd.h>
+#include "scsi_transport_api.h"
 
 #include <linux/libata.h>
 
@@ -432,7 +433,7 @@ void ata_port_schedule_eh(struct ata_port *ap)
 	WARN_ON(!ap->ops->error_handler);
 
 	ap->flags |= ATA_FLAG_EH_PENDING;
-	ata_schedule_scsi_eh(ap->host);
+	scsi_schedule_eh(ap->host);
 
 	DPRINTK("port EH scheduled\n");
 }

drivers/scsi/libata-scsi.c

@@ -2745,27 +2745,3 @@ void ata_scsi_scan_host(struct ata_port *ap)
 			scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0);
 	}
 }
-
-/**
- *	ata_schedule_scsi_eh - schedule EH for SCSI host
- *	@shost:	SCSI host to invoke error handling on.
- *
- *	Schedule SCSI EH without scmd.  This is a hack.
- *
- *	LOCKING:
- *	spin_lock_irqsave(host_set lock)
- **/
-void ata_schedule_scsi_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);
-}

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.

drivers/scsi/scsi_priv.h

@@ -63,6 +63,7 @@ extern int scsi_delete_timer(struct scsi_cmnd *);
 extern void scsi_times_out(struct scsi_cmnd *cmd);
 extern int scsi_error_handler(void *host);
 extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
+extern void scsi_eh_wakeup(struct Scsi_Host *shost);
 extern int scsi_eh_scmd_add(struct scsi_cmnd *, int);
 
 /* scsi_lib.c */

drivers/scsi/scsi_transport_api.h

@@ -0,0 +1,6 @@
+#ifndef _SCSI_TRANSPORT_API_H
+#define _SCSI_TRANSPORT_API_H
+
+void scsi_schedule_eh(struct Scsi_Host *shost);
+
+#endif /* _SCSI_TRANSPORT_API_H */

include/scsi/scsi_eh.h

@@ -35,7 +35,6 @@ static inline int scsi_sense_valid(struct scsi_sense_hdr *sshdr)
 }
 
 
-extern void scsi_eh_wakeup(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);