[PATCH 4.1 113/123] qla2xxx: Fix hardware lock/unlock issue causing kernel panic.

From: Greg Kroah-Hartman
Date: Sat Aug 08 2015 - 18:20:48 EST


4.1-stable review patch. If anyone has any objections, please let me know.

------------------

From: Saurav Kashyap <saurav.kashyap@xxxxxxxxxx>

commit ba9f6f64a0ff6b7ecaed72144c179061f8eca378 upstream.

[ Upstream commit ef86cb2059a14b4024c7320999ee58e938873032 ]

This patch fixes a kernel panic for qla2xxx Target core
Module driver introduced by a fix in the qla2xxx initiator code.

Commit ef86cb2 ("qla2xxx: Mark port lost when we receive an RSCN for it.")
introduced the regression for qla2xxx Target driver.

Stack trace will have following signature

--- <NMI exception stack> ---
[ffff88081faa3cc8] _raw_spin_lock_irqsave at ffffffff815b1f03
[ffff88081faa3cd0] qlt_fc_port_deleted at ffffffffa096ccd0 [qla2xxx]
[ffff88081faa3d20] qla2x00_schedule_rport_del at ffffffffa0913831[qla2xxx]
[ffff88081faa3d50] qla2x00_mark_device_lost at ffffffffa09159c5[qla2xxx]
[ffff88081faa3db0] qla2x00_async_event at ffffffffa0938d59 [qla2xxx]
[ffff88081faa3e30] qla24xx_msix_default at ffffffffa093a326 [qla2xxx]
[ffff88081faa3e90] handle_irq_event_percpu at ffffffff810a7b8d
[ffff88081faa3ee0] handle_irq_event at ffffffff810a7d32
[ffff88081faa3f10] handle_edge_irq at ffffffff810ab6b9
[ffff88081faa3f30] handle_irq at ffffffff8100619c
[ffff88081faa3f70] do_IRQ at ffffffff815b4b1c
--- <IRQ stack> ---

Signed-off-by: Saurav Kashyap <saurav.kashyap@xxxxxxxxxx>
Signed-off-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Reviewed-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/qla2xxx/qla_init.c | 4 ++++
drivers/scsi/qla2xxx/qla_target.c | 6 ------
2 files changed, 4 insertions(+), 6 deletions(-)

--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -2924,6 +2924,7 @@ qla2x00_rport_del(void *data)
struct fc_rport *rport;
scsi_qla_host_t *vha = fcport->vha;
unsigned long flags;
+ unsigned long vha_flags;

spin_lock_irqsave(fcport->vha->host->host_lock, flags);
rport = fcport->drport ? fcport->drport: fcport->rport;
@@ -2935,7 +2936,9 @@ qla2x00_rport_del(void *data)
* Release the target mode FC NEXUS in qla_target.c code
* if target mod is enabled.
*/
+ spin_lock_irqsave(&vha->hw->hardware_lock, vha_flags);
qlt_fc_port_deleted(vha, fcport);
+ spin_unlock_irqrestore(&vha->hw->hardware_lock, vha_flags);
}
}

@@ -3303,6 +3306,7 @@ qla2x00_reg_remote_port(scsi_qla_host_t
* Create target mode FC NEXUS in qla_target.c if target mode is
* enabled..
*/
+
qlt_fc_port_added(vha, fcport);

spin_lock_irqsave(fcport->vha->host->host_lock, flags);
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -782,10 +782,8 @@ void qlt_fc_port_added(struct scsi_qla_h

void qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport)
{
- struct qla_hw_data *ha = vha->hw;
struct qla_tgt *tgt = vha->vha_tgt.qla_tgt;
struct qla_tgt_sess *sess;
- unsigned long flags;

if (!vha->hw->tgt.tgt_ops)
return;
@@ -793,14 +791,11 @@ void qlt_fc_port_deleted(struct scsi_qla
if (!tgt || (fcport->port_type != FCT_INITIATOR))
return;

- spin_lock_irqsave(&ha->hardware_lock, flags);
if (tgt->tgt_stop) {
- spin_unlock_irqrestore(&ha->hardware_lock, flags);
return;
}
sess = qlt_find_sess_by_port_name(tgt, fcport->port_name);
if (!sess) {
- spin_unlock_irqrestore(&ha->hardware_lock, flags);
return;
}

@@ -808,7 +803,6 @@ void qlt_fc_port_deleted(struct scsi_qla

sess->local = 1;
qlt_schedule_sess_for_deletion(sess, false);
- spin_unlock_irqrestore(&ha->hardware_lock, flags);
}

static inline int test_tgt_sess_count(struct qla_tgt *tgt)


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