[SCSI] scsi_transport_fc: Introduce helper function for blocking scsi_eh

Move the duplicated code from FC LLDs to SCSI FC transport class.
Acked-by: NJames Smart <james.smart@emulex.com>
Acked-by: NGiridhar Malavali <giridhar.malavali@qlogic.com>
Acked-by: NAbhijeet Joglekar <abjoglek@cisco.com>
Signed-off-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>

drivers/scsi/fnic/fnic_scsi.c

@@ -1225,22 +1225,6 @@ void fnic_terminate_rport_io(struct fc_rport *rport)
 
 }
 
-static void fnic_block_error_handler(struct scsi_cmnd *sc)
-{
-	struct Scsi_Host *shost = sc->device->host;
-	struct fc_rport *rport = starget_to_rport(scsi_target(sc->device));
-	unsigned long flags;
-
-	spin_lock_irqsave(shost->host_lock, flags);
-	while (rport->port_state == FC_PORTSTATE_BLOCKED) {
-		spin_unlock_irqrestore(shost->host_lock, flags);
-		msleep(1000);
-		spin_lock_irqsave(shost->host_lock, flags);
-	}
-	spin_unlock_irqrestore(shost->host_lock, flags);
-
-}
-
 /*
  * This function is exported to SCSI for sending abort cmnds.
  * A SCSI IO is represented by a io_req in the driver.
@@ -1260,7 +1244,7 @@ int fnic_abort_cmd(struct scsi_cmnd *sc)
 	DECLARE_COMPLETION_ONSTACK(tm_done);
 
 	/* Wait for rport to unblock */
-	fnic_block_error_handler(sc);
+	fc_block_scsi_eh(sc);
 
 	/* Get local-port, check ready and link up */
 	lp = shost_priv(sc->device->host);
@@ -1542,7 +1526,7 @@ int fnic_device_reset(struct scsi_cmnd *sc)
 	DECLARE_COMPLETION_ONSTACK(tm_done);
 
 	/* Wait for rport to unblock */
-	fnic_block_error_handler(sc);
+	fc_block_scsi_eh(sc);
 
 	/* Get local-port, check ready and link up */
 	lp = shost_priv(sc->device->host);

drivers/scsi/lpfc/lpfc_scsi.c

@@ -2916,28 +2916,6 @@ lpfc_queuecommand(struct scsi_cmnd *cmnd, void (*done) (struct scsi_cmnd *))
 	return 0;
 }
 
-/**
- * lpfc_block_error_handler - Routine to block error  handler
- * @cmnd: Pointer to scsi_cmnd data structure.
- *
- *  This routine blocks execution till fc_rport state is not FC_PORSTAT_BLCOEKD.
- **/
-static void
-lpfc_block_error_handler(struct scsi_cmnd *cmnd)
-{
-	struct Scsi_Host *shost = cmnd->device->host;
-	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
-
-	spin_lock_irq(shost->host_lock);
-	while (rport->port_state == FC_PORTSTATE_BLOCKED) {
-		spin_unlock_irq(shost->host_lock);
-		msleep(1000);
-		spin_lock_irq(shost->host_lock);
-	}
-	spin_unlock_irq(shost->host_lock);
-	return;
-}
-
 /**
  * lpfc_abort_handler - scsi_host_template eh_abort_handler entry point
  * @cmnd: Pointer to scsi_cmnd data structure.
@@ -2961,7 +2939,7 @@ lpfc_abort_handler(struct scsi_cmnd *cmnd)
 	int ret = SUCCESS;
 	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waitq);
 
-	lpfc_block_error_handler(cmnd);
+	fc_block_scsi_eh(cmnd);
 	lpfc_cmd = (struct lpfc_scsi_buf *)cmnd->host_scribble;
 	BUG_ON(!lpfc_cmd);
 
@@ -3259,7 +3237,7 @@ lpfc_device_reset_handler(struct scsi_cmnd *cmnd)
 	struct lpfc_scsi_event_header scsi_event;
 	int status;
 
-	lpfc_block_error_handler(cmnd);
+	fc_block_scsi_eh(cmnd);
 
 	status = lpfc_chk_tgt_mapped(vport, cmnd);
 	if (status == FAILED) {
@@ -3318,7 +3296,7 @@ lpfc_target_reset_handler(struct scsi_cmnd *cmnd)
 	struct lpfc_scsi_event_header scsi_event;
 	int status;
 
-	lpfc_block_error_handler(cmnd);
+	fc_block_scsi_eh(cmnd);
 
 	status = lpfc_chk_tgt_mapped(vport, cmnd);
 	if (status == FAILED) {
@@ -3384,7 +3362,7 @@ lpfc_bus_reset_handler(struct scsi_cmnd *cmnd)
 	fc_host_post_vendor_event(shost, fc_get_event_number(),
 		sizeof(scsi_event), (char *)&scsi_event, LPFC_NL_VENDOR_ID);
 
-	lpfc_block_error_handler(cmnd);
+	fc_block_scsi_eh(cmnd);
 
 	/*
 	 * Since the driver manages a single bus device, reset all

drivers/scsi/qla2xxx/qla_os.c

@@ -728,23 +728,6 @@ qla2x00_abort_fcport_cmds(fc_port_t *fcport)
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 }
 
-static void
-qla2x00_block_error_handler(struct scsi_cmnd *cmnd)
-{
-	struct Scsi_Host *shost = cmnd->device->host;
-	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
-	unsigned long flags;
-
-	spin_lock_irqsave(shost->host_lock, flags);
-	while (rport->port_state == FC_PORTSTATE_BLOCKED) {
-		spin_unlock_irqrestore(shost->host_lock, flags);
-		msleep(1000);
-		spin_lock_irqsave(shost->host_lock, flags);
-	}
-	spin_unlock_irqrestore(shost->host_lock, flags);
-	return;
-}
-
 /**************************************************************************
 * qla2xxx_eh_abort
 *
@@ -774,7 +757,7 @@ qla2xxx_eh_abort(struct scsi_cmnd *cmd)
 	struct req_que *req = vha->req;
 	srb_t *spt;
 
-	qla2x00_block_error_handler(cmd);
+	fc_block_scsi_eh(cmd);
 
 	if (!CMD_SP(cmd))
 		return SUCCESS;
@@ -905,7 +888,7 @@ __qla2xxx_eh_generic_reset(char *name, enum nexus_wait_type type,
 	fc_port_t *fcport = (struct fc_port *) cmd->device->hostdata;
 	int err;
 
-	qla2x00_block_error_handler(cmd);
+	fc_block_scsi_eh(cmd);
 
 	if (!fcport)
 		return FAILED;
@@ -985,7 +968,7 @@ qla2xxx_eh_bus_reset(struct scsi_cmnd *cmd)
 	unsigned long serial;
 	srb_t *sp = (srb_t *) CMD_SP(cmd);
 
-	qla2x00_block_error_handler(cmd);
+	fc_block_scsi_eh(cmd);
 
 	id = cmd->device->id;
 	lun = cmd->device->lun;
@@ -1048,7 +1031,7 @@ qla2xxx_eh_host_reset(struct scsi_cmnd *cmd)
 	srb_t *sp = (srb_t *) CMD_SP(cmd);
 	scsi_qla_host_t *base_vha = pci_get_drvdata(ha->pdev);
 
-	qla2x00_block_error_handler(cmd);
+	fc_block_scsi_eh(cmd);
 
 	id = cmd->device->id;
 	lun = cmd->device->lun;

drivers/scsi/scsi_transport_fc.c

@@ -27,6 +27,7 @@
  */
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_transport.h>
@@ -3144,6 +3145,31 @@ fc_scsi_scan_rport(struct work_struct *work)
 	spin_unlock_irqrestore(shost->host_lock, flags);
 }
 
+/**
+ * fc_block_scsi_eh - Block SCSI eh thread for blocked fc_rport
+ * @cmnd: SCSI command that scsi_eh is trying to recover
+ *
+ * This routine can be called from a FC LLD scsi_eh callback. It
+ * blocks the scsi_eh thread until the fc_rport leaves the
+ * FC_PORTSTATE_BLOCKED. This is necessary to avoid the scsi_eh
+ * failing recovery actions for blocked rports which would lead to
+ * offlined SCSI devices.
+ */
+void fc_block_scsi_eh(struct scsi_cmnd *cmnd)
+{
+	struct Scsi_Host *shost = cmnd->device->host;
+	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
+	unsigned long flags;
+
+	spin_lock_irqsave(shost->host_lock, flags);
+	while (rport->port_state == FC_PORTSTATE_BLOCKED) {
+		spin_unlock_irqrestore(shost->host_lock, flags);
+		msleep(1000);
+		spin_lock_irqsave(shost->host_lock, flags);
+	}
+	spin_unlock_irqrestore(shost->host_lock, flags);
+}
+EXPORT_SYMBOL(fc_block_scsi_eh);
 
 /**
  * fc_vport_setup - allocates and creates a FC virtual port.

include/scsi/scsi_transport_fc.h

@@ -807,5 +807,6 @@ void fc_host_post_vendor_event(struct Scsi_Host *shost, u32 event_number,
 struct fc_vport *fc_vport_create(struct Scsi_Host *shost, int channel,
 		struct fc_vport_identifiers *);
 int fc_vport_terminate(struct fc_vport *vport);
+void fc_block_scsi_eh(struct scsi_cmnd *cmnd);
 
 #endif /* SCSI_TRANSPORT_FC_H */