From feab4ae73031699fcf92a88f4b1e4ec1b14157a5 Mon Sep 17 00:00:00 2001 From: Joe Eykholt Date: Tue, 25 Aug 2009 14:03:36 -0700 Subject: [PATCH] [SCSI] libfc: re-login to remote ports that send us LOGO After a quick link flap, a target was seen to send us a LOGO. Apparently, it saw an RSCN reporting that we had dropped out of the fabric after we had logged back into it. This is likely in larger fabrics (more than 2 FC switches) after a quick link flap at the initiator. Each link transition causes an port-specific RSCN to the target. After the link comes back up, the initiator successfully discovers and does a PLOGI to the target before the target sees the first RSCN reporting the initiator is gone, and it sends a LOGO. The target may see a subsequent RSCN saying the port is back, but probably wouldn't send a PLOGI and leaves it up to the initiator to re-login. An RSCN can be delayed by the switches due to software layers but a PLOGI is forwarded in hardware causing the PLOGI to beat the RSCN. If a remote port is in the discovered set and sends a LOGO, re-login to it. Signed-off-by: Joe Eykholt Signed-off-by: Robert Love Signed-off-by: James Bottomley --- drivers/scsi/libfc/fc_rport.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c index 04e9846ad1b5..dc97c603744f 100644 --- a/drivers/scsi/libfc/fc_rport.c +++ b/drivers/scsi/libfc/fc_rport.c @@ -1340,6 +1340,8 @@ static void fc_rport_recv_logo_req(struct fc_lport *lport, struct fc_rport_priv *rdata; u32 sid; + lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL); + fh = fc_frame_header_get(fp); sid = ntoh24(fh->fh_s_id); @@ -1349,13 +1351,20 @@ static void fc_rport_recv_logo_req(struct fc_lport *lport, mutex_lock(&rdata->rp_mutex); FC_RPORT_DBG(rdata, "Received LOGO request while in state %s\n", fc_rport_state(rdata)); - fc_rport_enter_delete(rdata, RPORT_EV_LOGO); + + /* + * If the remote port was created due to discovery, + * log back in. It may have seen a stale RSCN about us. + */ + if (rdata->rp_state != RPORT_ST_DELETE && rdata->disc_id) + fc_rport_enter_plogi(rdata); + else + fc_rport_enter_delete(rdata, RPORT_EV_LOGO); mutex_unlock(&rdata->rp_mutex); } else FC_RPORT_ID_DBG(lport, sid, "Received LOGO from non-logged-in port\n"); mutex_unlock(&lport->disc.disc_mutex); - lport->tt.seq_els_rsp_send(sp, ELS_LS_ACC, NULL); fc_frame_free(fp); } -- 2.20.1