Commit 6755db1c authored by Chris Leech's avatar Chris Leech Committed by James Bottomley
Browse files

[SCSI] libfc: rport retry on LS_RJT from certain ELS 



This allows any rport ELS to retry on LS_RJT.

The rport error handling would only retry on resource allocation failures
and exchange timeouts.  I have a target that will occasionally reject PLOGI
when we do a quick LOGO/PLOGI.  When a critical ELS was rejected, libfc would
fail silently leaving the rport in a dead state.

The retry count and delay are managed by fc_rport_error_retry.  If the retry
count is exceeded fc_rport_error will be called.  When retrying is not the
correct course of action, fc_rport_error can be called directly.

Signed-off-by: default avatarChris Leech <christopher.leech@intel.com>
Signed-off-by: default avatarRobert Love <robert.w.love@intel.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent bc0e17f6

drivers/scsi/libfc/fc_exch.c

+0 −2
Original line number Diff line number Diff line
@@ -32,8 +32,6 @@ 
#include <scsi/libfc.h>

#include <scsi/fc_encode.h>



#define	  FC_DEF_R_A_TOV      (10 * 1000) /* resource allocation timeout */



/*

 * fc_exch_debug can be set in debugger or at compile time to get more logs.

 */

drivers/scsi/libfc/fc_rport.c

+64 −47
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ static void fc_rport_recv_logo_req(struct fc_rport *, 
				   struct fc_seq *, struct fc_frame *);

static void fc_rport_timeout(struct work_struct *);

static void fc_rport_error(struct fc_rport *, struct fc_frame *);

static void fc_rport_error_retry(struct fc_rport *, struct fc_frame *);

static void fc_rport_work(struct work_struct *);



static const char *fc_rport_state_names[] = {
@@ -410,37 +411,20 @@ static void fc_rport_timeout(struct work_struct *work) 
}



/**

 * fc_rport_error - Handler for any errors

 * fc_rport_error - Error handler, called once retries have been exhausted

 * @rport: The fc_rport object

 * @fp: The frame pointer

 *

 * If the error was caused by a resource allocation failure

 * then wait for half a second and retry, otherwise retry

 * immediately.

 *

 * Locking Note: The rport lock is expected to be held before

 * calling this routine

 */

static void fc_rport_error(struct fc_rport *rport, struct fc_frame *fp)

{

	struct fc_rport_libfc_priv *rdata = rport->dd_data;

	unsigned long delay = 0;



	FC_DEBUG_RPORT("Error %ld in state %s, retries %d\n",

		       PTR_ERR(fp), fc_rport_state(rport), rdata->retries);



	if (!fp || PTR_ERR(fp) == -FC_EX_TIMEOUT) {

		/*

		 * Memory allocation failure, or the exchange timed out.

		 *  Retry after delay

		 */

		if (rdata->retries < rdata->local_port->max_retry_count) {

			rdata->retries++;

			if (!fp)

				delay = msecs_to_jiffies(500);

			get_device(&rport->dev);

			schedule_delayed_work(&rdata->retry_work, delay);

		} else {

	switch (rdata->rp_state) {

	case RPORT_ST_PLOGI:

	case RPORT_ST_PRLI:
@@ -458,7 +442,40 @@ static void fc_rport_error(struct fc_rport *rport, struct fc_frame *fp) 
		break;

	}

}



/**

 * fc_rport_error_retry - Error handler when retries are desired

 * @rport: The fc_rport object

 * @fp: The frame pointer

 *

 * If the error was an exchange timeout retry immediately,

 * otherwise wait for E_D_TOV.

 *

 * Locking Note: The rport lock is expected to be held before

 * calling this routine

 */

static void fc_rport_error_retry(struct fc_rport *rport, struct fc_frame *fp)

{

	struct fc_rport_libfc_priv *rdata = rport->dd_data;

	unsigned long delay = FC_DEF_E_D_TOV;



	/* make sure this isn't an FC_EX_CLOSED error, never retry those */

	if (PTR_ERR(fp) == -FC_EX_CLOSED)

		return fc_rport_error(rport, fp);



	if (rdata->retries < rdata->local_port->max_retry_count) {

		FC_DEBUG_RPORT("Error %ld in state %s, retrying\n",

			       PTR_ERR(fp), fc_rport_state(rport));

		rdata->retries++;

		/* no additional delay on exchange timeouts */

		if (PTR_ERR(fp) == -FC_EX_TIMEOUT)

			delay = 0;

		get_device(&rport->dev);

		schedule_delayed_work(&rdata->retry_work, delay);

		return;

	}



	return fc_rport_error(rport, fp);

}



/**
@@ -495,7 +512,7 @@ static void fc_rport_plogi_resp(struct fc_seq *sp, struct fc_frame *fp, 
	}



	if (IS_ERR(fp)) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		goto err;

	}
@@ -527,7 +544,7 @@ static void fc_rport_plogi_resp(struct fc_seq *sp, struct fc_frame *fp, 
		else

			fc_rport_enter_prli(rport);

	} else

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);



out:

	fc_frame_free(fp);
@@ -557,14 +574,14 @@ static void fc_rport_enter_plogi(struct fc_rport *rport) 
	rport->maxframe_size = FC_MIN_MAX_PAYLOAD;

	fp = fc_frame_alloc(lport, sizeof(struct fc_els_flogi));

	if (!fp) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		return;

	}

	rdata->e_d_tov = lport->e_d_tov;



	if (!lport->tt.elsct_send(lport, rport, fp, ELS_PLOGI,

				  fc_rport_plogi_resp, rport, lport->e_d_tov))

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

	else

		get_device(&rport->dev);

}
@@ -604,7 +621,7 @@ static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp, 
	}



	if (IS_ERR(fp)) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		goto err;

	}
@@ -662,7 +679,7 @@ static void fc_rport_logo_resp(struct fc_seq *sp, struct fc_frame *fp, 
		       rport->port_id);



	if (IS_ERR(fp)) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		goto err;

	}
@@ -712,13 +729,13 @@ static void fc_rport_enter_prli(struct fc_rport *rport) 


	fp = fc_frame_alloc(lport, sizeof(*pp));

	if (!fp) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		return;

	}



	if (!lport->tt.elsct_send(lport, rport, fp, ELS_PRLI,

				  fc_rport_prli_resp, rport, lport->e_d_tov))

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

	else

		get_device(&rport->dev);

}
@@ -809,13 +826,13 @@ static void fc_rport_enter_rtv(struct fc_rport *rport) 


	fp = fc_frame_alloc(lport, sizeof(struct fc_els_rtv));

	if (!fp) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		return;

	}



	if (!lport->tt.elsct_send(lport, rport, fp, ELS_RTV,

				     fc_rport_rtv_resp, rport, lport->e_d_tov))

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

	else

		get_device(&rport->dev);

}
@@ -840,13 +857,13 @@ static void fc_rport_enter_logo(struct fc_rport *rport) 


	fp = fc_frame_alloc(lport, sizeof(struct fc_els_logo));

	if (!fp) {

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

		return;

	}



	if (!lport->tt.elsct_send(lport, rport, fp, ELS_LOGO,

				  fc_rport_logo_resp, rport, lport->e_d_tov))

		fc_rport_error(rport, fp);

		fc_rport_error_retry(rport, fp);

	else

		get_device(&rport->dev);

}

include/scsi/fc/fc_fs.h

+5 −0
Original line number Diff line number Diff line
@@ -337,4 +337,9 @@ enum fc_pf_rjt_reason { 
	FC_RJT_VENDOR =		0xff,	/* vendor specific reject */

};



/* default timeout values */



#define FC_DEF_E_D_TOV	2000UL

#define FC_DEF_R_A_TOV	10000UL



#endif /* _FC_FS_H_ */

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