[SCSI] libfc: fix oops in point-to-point mode

In point-to-point mode, if the PLOGI to the remote port times
out, it can get deleted by the remote port module.  Since there's
no reference by the local port, lport->ptp_data points to a freed
rport, and when the local port is reset and tries to logout again,
an oops occurs in mutex_lock_nested().

Hold a reference count on the point-to-point rdata.

Signed-off-by: Joe Eykholt <jeykholt@cisco.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index d126ecfff70484ea49908f1cde4e8d007a64bbb8..fe8700f4326a8e11f9254c0a2f04940d682ad990 100644 (file)
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -228,9 +228,12 @@ static void fc_lport_ptp_setup(struct fc_lport *lport,
                               u64 remote_wwnn)
 {
        mutex_lock(&lport->disc.disc_mutex);
-       if (lport->ptp_rdata)
+       if (lport->ptp_rdata) {
                lport->tt.rport_logoff(lport->ptp_rdata);
+               kref_put(&lport->ptp_rdata->kref, lport->tt.rport_destroy);
+       }
        lport->ptp_rdata = lport->tt.rport_create(lport, remote_fid);
+       kref_get(&lport->ptp_rdata->kref);
        lport->ptp_rdata->ids.port_name = remote_wwpn;
        lport->ptp_rdata->ids.node_name = remote_wwnn;
        mutex_unlock(&lport->disc.disc_mutex);
@@ -947,7 +950,11 @@ static void fc_lport_reset_locked(struct fc_lport *lport)
        if (lport->dns_rdata)
                lport->tt.rport_logoff(lport->dns_rdata);
 
-       lport->ptp_rdata = NULL;
+       if (lport->ptp_rdata) {
+               lport->tt.rport_logoff(lport->ptp_rdata);
+               kref_put(&lport->ptp_rdata->kref, lport->tt.rport_destroy);
+               lport->ptp_rdata = NULL;
+       }
 
        lport->tt.disc_stop(lport);