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[SCSI] libfc: use rport timeout values for fcp recovery
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Use the rport value for rec_tov for timeout values when
sending fcp commands. Currently, defaults are being used
which may or may not match the advertised values.

The default may cause i/o to timeout on networks that
set this value larger then the default value. To make
the timeout more configurable in the non-REC mode we
remove the FC_SCSI_ER_TIMEOUT completely allowing the
scsi-ml to do the timeout. This removes an unneeded
timer and allows the i/o timeout to be configured
using the scsi-ml knobs.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
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john fastabend authored and James Bottomley committed Dec 21, 2010
1 parent ac17ea8 commit e0883a3
Showing 1 changed file with 42 additions and 16 deletions.
58 changes: 42 additions & 16 deletions drivers/scsi/libfc/fc_fcp.c
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Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,9 @@ struct kmem_cache *scsi_pkt_cachep;
#define FC_SRB_READ (1 << 1)
#define FC_SRB_WRITE (1 << 0)

/* constant added to e_d_tov timeout to get rec_tov value */
#define REC_TOV_CONST 1

/*
* The SCp.ptr should be tested and set under the scsi_pkt_queue lock
*/
Expand Down Expand Up @@ -126,9 +129,7 @@ static void fc_fcp_srr_error(struct fc_fcp_pkt *, struct fc_frame *);
/*
* Error recovery timeout values.
*/
#define FC_SCSI_ER_TIMEOUT (10 * HZ)
#define FC_SCSI_TM_TOV (10 * HZ)
#define FC_SCSI_REC_TOV (2 * HZ)
#define FC_HOST_RESET_TIMEOUT (30 * HZ)
#define FC_CAN_QUEUE_PERIOD (60 * HZ)

Expand Down Expand Up @@ -1082,6 +1083,21 @@ static int fc_fcp_pkt_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp)
return rc;
}

/**
* get_fsp_rec_tov() - Helper function to get REC_TOV
* @fsp: the FCP packet
*/
static inline unsigned int get_fsp_rec_tov(struct fc_fcp_pkt *fsp)
{
struct fc_rport *rport;
struct fc_rport_libfc_priv *rpriv;

rport = fsp->rport;
rpriv = rport->dd_data;

return rpriv->e_d_tov + REC_TOV_CONST;
}

/**
* fc_fcp_cmd_send() - Send a FCP command
* @lport: The local port to send the command on
Expand All @@ -1099,6 +1115,7 @@ static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
struct fc_rport_libfc_priv *rpriv;
const size_t len = sizeof(fsp->cdb_cmd);
int rc = 0;
unsigned int rec_tov;

if (fc_fcp_lock_pkt(fsp))
return 0;
Expand Down Expand Up @@ -1129,10 +1146,12 @@ static int fc_fcp_cmd_send(struct fc_lport *lport, struct fc_fcp_pkt *fsp,
fsp->seq_ptr = seq;
fc_fcp_pkt_hold(fsp); /* hold for fc_fcp_pkt_destroy */

rec_tov = get_fsp_rec_tov(fsp);

setup_timer(&fsp->timer, fc_fcp_timeout, (unsigned long)fsp);
fc_fcp_timer_set(fsp,
(fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED) ?
FC_SCSI_REC_TOV : FC_SCSI_ER_TIMEOUT);

if (fsp->tgt_flags & FC_RP_FLAGS_REC_SUPPORTED)
fc_fcp_timer_set(fsp, rec_tov);
unlock:
fc_fcp_unlock_pkt(fsp);
return rc;
Expand Down Expand Up @@ -1207,13 +1226,16 @@ static void fc_lun_reset_send(unsigned long data)
{
struct fc_fcp_pkt *fsp = (struct fc_fcp_pkt *)data;
struct fc_lport *lport = fsp->lp;
unsigned int rec_tov;

if (lport->tt.fcp_cmd_send(lport, fsp, fc_tm_done)) {
if (fsp->recov_retry++ >= FC_MAX_RECOV_RETRY)
return;
if (fc_fcp_lock_pkt(fsp))
return;
rec_tov = get_fsp_rec_tov(fsp);
setup_timer(&fsp->timer, fc_lun_reset_send, (unsigned long)fsp);
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
fc_fcp_timer_set(fsp, rec_tov);
fc_fcp_unlock_pkt(fsp);
}
}
Expand Down Expand Up @@ -1351,9 +1373,6 @@ static void fc_fcp_timeout(unsigned long data)

if (rpriv->flags & FC_RP_FLAGS_REC_SUPPORTED)
fc_fcp_rec(fsp);
else if (time_after_eq(fsp->last_pkt_time + (FC_SCSI_ER_TIMEOUT / 2),
jiffies))
fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
else if (fsp->state & FC_SRB_RCV_STATUS)
fc_fcp_complete_locked(fsp);
else
Expand All @@ -1373,6 +1392,7 @@ static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
struct fc_frame *fp;
struct fc_rport *rport;
struct fc_rport_libfc_priv *rpriv;
unsigned int rec_tov;

lport = fsp->lp;
rport = fsp->rport;
Expand All @@ -1383,6 +1403,9 @@ static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
fc_fcp_complete_locked(fsp);
return;
}

rec_tov = get_fsp_rec_tov(fsp);

fp = fc_fcp_frame_alloc(lport, sizeof(struct fc_els_rec));
if (!fp)
goto retry;
Expand All @@ -1393,13 +1416,13 @@ static void fc_fcp_rec(struct fc_fcp_pkt *fsp)
FC_FCTL_REQ, 0);
if (lport->tt.elsct_send(lport, rport->port_id, fp, ELS_REC,
fc_fcp_rec_resp, fsp,
jiffies_to_msecs(FC_SCSI_REC_TOV))) {
jiffies_to_msecs(rec_tov))) {
fc_fcp_pkt_hold(fsp); /* hold while REC outstanding */
return;
}
retry:
if (fsp->recov_retry++ < FC_MAX_RECOV_RETRY)
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
fc_fcp_timer_set(fsp, rec_tov);
else
fc_fcp_recovery(fsp, FC_TIMED_OUT);
}
Expand Down Expand Up @@ -1455,7 +1478,6 @@ static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
* making progress.
*/
rpriv->flags &= ~FC_RP_FLAGS_REC_SUPPORTED;
fc_fcp_timer_set(fsp, FC_SCSI_ER_TIMEOUT);
break;
case ELS_RJT_LOGIC:
case ELS_RJT_UNAB:
Expand Down Expand Up @@ -1508,12 +1530,12 @@ static void fc_fcp_rec_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
}
fc_fcp_srr(fsp, r_ctl, offset);
} else if (e_stat & ESB_ST_SEQ_INIT) {

unsigned int rec_tov = get_fsp_rec_tov(fsp);
/*
* The remote port has the initiative, so just
* keep waiting for it to complete.
*/
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
fc_fcp_timer_set(fsp, rec_tov);
} else {

/*
Expand Down Expand Up @@ -1626,6 +1648,7 @@ static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
struct fcp_srr *srr;
struct fc_frame *fp;
u8 cdb_op;
unsigned int rec_tov;

rport = fsp->rport;
rpriv = rport->dd_data;
Expand All @@ -1650,8 +1673,9 @@ static void fc_fcp_srr(struct fc_fcp_pkt *fsp, enum fc_rctl r_ctl, u32 offset)
rpriv->local_port->port_id, FC_TYPE_FCP,
FC_FCTL_REQ, 0);

rec_tov = get_fsp_rec_tov(fsp);
seq = lport->tt.exch_seq_send(lport, fp, fc_fcp_srr_resp, NULL,
fsp, jiffies_to_msecs(FC_SCSI_REC_TOV));
fsp, jiffies_to_msecs(rec_tov));
if (!seq)
goto retry;

Expand All @@ -1675,6 +1699,7 @@ static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
{
struct fc_fcp_pkt *fsp = arg;
struct fc_frame_header *fh;
unsigned int rec_tov;

if (IS_ERR(fp)) {
fc_fcp_srr_error(fsp, fp);
Expand All @@ -1701,7 +1726,8 @@ static void fc_fcp_srr_resp(struct fc_seq *seq, struct fc_frame *fp, void *arg)
switch (fc_frame_payload_op(fp)) {
case ELS_LS_ACC:
fsp->recov_retry = 0;
fc_fcp_timer_set(fsp, FC_SCSI_REC_TOV);
rec_tov = get_fsp_rec_tov(fsp);
fc_fcp_timer_set(fsp, rec_tov);
break;
case ELS_LS_RJT:
default:
Expand Down

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