From 785141c62a26f055b27355ee9234e145955a51c6 Mon Sep 17 00:00:00 2001 From: Chad Dupuis Date: Fri, 30 Sep 2016 11:01:16 +0200 Subject: [PATCH] scsi: libfc: Do not take rdata->rp_mutex when processing a -FC_EX_CLOSED ELS response. When an ELS response handler receives a -FC_EX_CLOSED, the rdata->rp_mutex is already held which can lead to a deadlock condition like the following stack trace: [] fc_rport_plogi_resp+0x28/0x200 [libfc] [] fc_invoke_resp+0x6a/0xe0 [libfc] [] fc_exch_mgr_reset+0x1b8/0x280 [libfc] [] fc_rport_logoff+0x43/0xd0 [libfc] [] fc_disc_stop+0x6d/0xf0 [libfc] [] fc_disc_stop_final+0xe/0x20 [libfc] [] fc_fabric_logoff+0x17/0x70 [libfc] The other ELS handlers need to follow the FLOGI response handler and simply do a kref_put against the fc_rport_priv struct and exit when receving a -FC_EX_CLOSED response. Signed-off-by: Chad Dupuis Reviewed-by: Hannes Reinecke Acked-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen --- drivers/scsi/libfc/fc_rport.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c index a0ceba10c679..ff33ae6bdf7c 100644 --- a/drivers/scsi/libfc/fc_rport.c +++ b/drivers/scsi/libfc/fc_rport.c @@ -952,10 +952,13 @@ static void fc_rport_plogi_resp(struct fc_seq *sp, struct fc_frame *fp, u16 cssp_seq; u8 op; - mutex_lock(&rdata->rp_mutex); - FC_RPORT_DBG(rdata, "Received a PLOGI %s\n", fc_els_resp_type(fp)); + if (fp == ERR_PTR(-FC_EX_CLOSED)) + goto put; + + mutex_lock(&rdata->rp_mutex); + if (rdata->rp_state != RPORT_ST_PLOGI) { FC_RPORT_DBG(rdata, "Received a PLOGI response, but in state " "%s\n", fc_rport_state(rdata)); @@ -994,6 +997,7 @@ out: fc_frame_free(fp); err: mutex_unlock(&rdata->rp_mutex); +put: kref_put(&rdata->kref, lport->tt.rport_destroy); } @@ -1079,10 +1083,13 @@ static void fc_rport_prli_resp(struct fc_seq *sp, struct fc_frame *fp, u8 op; u8 resp_code = 0; - mutex_lock(&rdata->rp_mutex); - FC_RPORT_DBG(rdata, "Received a PRLI %s\n", fc_els_resp_type(fp)); + if (fp == ERR_PTR(-FC_EX_CLOSED)) + goto put; + + mutex_lock(&rdata->rp_mutex); + if (rdata->rp_state != RPORT_ST_PRLI) { FC_RPORT_DBG(rdata, "Received a PRLI response, but in state " "%s\n", fc_rport_state(rdata)); @@ -1150,6 +1157,7 @@ out: fc_frame_free(fp); err: mutex_unlock(&rdata->rp_mutex); +put: kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy); } @@ -1230,10 +1238,13 @@ static void fc_rport_rtv_resp(struct fc_seq *sp, struct fc_frame *fp, struct fc_rport_priv *rdata = rdata_arg; u8 op; - mutex_lock(&rdata->rp_mutex); - FC_RPORT_DBG(rdata, "Received a RTV %s\n", fc_els_resp_type(fp)); + if (fp == ERR_PTR(-FC_EX_CLOSED)) + goto put; + + mutex_lock(&rdata->rp_mutex); + if (rdata->rp_state != RPORT_ST_RTV) { FC_RPORT_DBG(rdata, "Received a RTV response, but in state " "%s\n", fc_rport_state(rdata)); @@ -1275,6 +1286,7 @@ out: fc_frame_free(fp); err: mutex_unlock(&rdata->rp_mutex); +put: kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy); } @@ -1374,10 +1386,13 @@ static void fc_rport_adisc_resp(struct fc_seq *sp, struct fc_frame *fp, struct fc_els_adisc *adisc; u8 op; - mutex_lock(&rdata->rp_mutex); - FC_RPORT_DBG(rdata, "Received a ADISC response\n"); + if (fp == ERR_PTR(-FC_EX_CLOSED)) + goto put; + + mutex_lock(&rdata->rp_mutex); + if (rdata->rp_state != RPORT_ST_ADISC) { FC_RPORT_DBG(rdata, "Received a ADISC resp but in state %s\n", fc_rport_state(rdata)); @@ -1412,6 +1427,7 @@ out: fc_frame_free(fp); err: mutex_unlock(&rdata->rp_mutex); +put: kref_put(&rdata->kref, rdata->local_port->tt.rport_destroy); } -- 2.39.5