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[SCSI] libfc: rport retry on LS_RJT from certain ELS
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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: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Chris Leech authored and James Bottomley committed Mar 6, 2009
1 parent bc0e17f commit 6755db1
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Showing 3 changed files with 69 additions and 49 deletions.
2 changes: 0 additions & 2 deletions drivers/scsi/libfc/fc_exch.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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.
*/
Expand Down
111 changes: 64 additions & 47 deletions drivers/scsi/libfc/fc_rport.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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[] = {
Expand Down Expand Up @@ -410,57 +411,73 @@ 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:
case RPORT_ST_LOGO:
rdata->event = RPORT_EV_FAILED;
queue_work(rport_event_queue,
&rdata->event_work);
break;
case RPORT_ST_RTV:
fc_rport_enter_ready(rport);
break;
case RPORT_ST_NONE:
case RPORT_ST_READY:
case RPORT_ST_INIT:
break;
}
}
switch (rdata->rp_state) {
case RPORT_ST_PLOGI:
case RPORT_ST_PRLI:
case RPORT_ST_LOGO:
rdata->event = RPORT_EV_FAILED;
queue_work(rport_event_queue,
&rdata->event_work);
break;
case RPORT_ST_RTV:
fc_rport_enter_ready(rport);
break;
case RPORT_ST_NONE:
case RPORT_ST_READY:
case RPORT_ST_INIT:
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);
}

/**
* fc_rport_plogi_recv_resp - Handle incoming ELS PLOGI response
* @sp: current sequence in the PLOGI exchange
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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);
}
Expand Down Expand Up @@ -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);
}
Expand All @@ -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);
}
Expand Down
5 changes: 5 additions & 0 deletions include/scsi/fc/fc_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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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