[PATCH 03/16] libfc: fix oops in point-to-point mode

Robert Love
2010-03-13T00:07:47Z

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>
---

drivers/scsi/libfc/fc_lport.c | 11 +++++++++--
1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/libfc/fc_lport.c b/drivers/scsi/libfc/fc_lport.c
index 7ec8ce7..af7343a 100644
--- a/drivers/scsi/libfc/fc_lport.c
+++ b/drivers/scsi/libfc/fc_lport.c
@@ -227,9 +227,12 @@ 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);
@@ -946,7 +949,11 @@ 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);