scsi: libfc: fix a deadlock in fc_rport_work

In places like fc_rport_recv_plogi_req and fcoe_ctlr_vn_add we always
take the lport disc_mutex lock before the rports mutex
(rp_mutex) lock. Gaurding list_del_rcu(&rdata->peers) with
disc.disc_mutex in fc_rport_work is correct but the rp_mutex lock
can and should to be dropped before taking that lock else results
in a deadlock.

Signed-off-by: Satish Kharat <satishkh@cisco.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Satish Kharat 2017-10-05 16:41:21 -07:00 committed by Martin K. Petersen
parent fbce4d97fd
commit d1b3f51ee1

View File

@ -383,11 +383,11 @@ static void fc_rport_work(struct work_struct *work)
fc_rport_enter_flogi(rdata);
mutex_unlock(&rdata->rp_mutex);
} else {
mutex_unlock(&rdata->rp_mutex);
FC_RPORT_DBG(rdata, "work delete\n");
mutex_lock(&lport->disc.disc_mutex);
list_del_rcu(&rdata->peers);
mutex_unlock(&lport->disc.disc_mutex);
mutex_unlock(&rdata->rp_mutex);
kref_put(&rdata->kref, fc_rport_destroy);
}
} else {