This patch fixes race on dpc_thread field of struct scsi_qla_host,
which can lead to crash on the module unload.
This patch is against 2.6.26
Signed-off-by: Vladislav Bolkhovitin <vst@xxxxxxxx>
qla_def.h | 1 +
qla_mbx.c | 2 +-
qla_os.c | 36 ++++++++++++++++++++++++++----------
3 files changed, 28 insertions(+), 11 deletions(-)
diff -upr linux-2.6.26/drivers/scsi/qla2xxx/qla_def.h linux-2.6.26/drivers/scsi/qla2xxx/qla_def.h
--- linux-2.6.26/drivers/scsi/qla2xxx/qla_def.h 2008-07-14 01:51:29.000000000 +0400
+++ linux-2.6.26/drivers/scsi/qla2xxx/qla_def.h 2008-07-24 10:07:39.000000000 +0400
@@ -2425,6 +2436,7 @@ typedef struct scsi_qla_host {
void *sfp_data;
dma_addr_t sfp_data_dma;
+ spinlock_t dpc_lock;
struct task_struct *dpc_thread;
uint8_t dpc_active; /* DPC routine is active */
diff -upr linux-2.6.26/drivers/scsi/qla2xxx/qla_mbx.c linux-2.6.26/drivers/scsi/qla2xxx/qla_mbx.c
--- linux-2.6.26/drivers/scsi/qla2xxx/qla_mbx.c 2008-07-14 01:51:29.000000000 +0400
+++ linux-2.6.26/drivers/scsi/qla2xxx/qla_mbx.c 2008-07-23 19:27:20.000000000 +0400
@@ -2683,7 +2687,7 @@ qla24xx_report_id_acquisition(scsi_qla_h
set_bit(VP_IDX_ACQUIRED, &vha->vp_flags);
set_bit(VP_DPC_NEEDED, &ha->dpc_flags);
- wake_up_process(ha->dpc_thread);
+ qla2xxx_wake_dpc(ha);
}
}
diff -upr linux-2.6.26/drivers/scsi/qla2xxx/qla_os.c linux-2.6.26/drivers/scsi/qla2xxx/qla_os.c
--- linux-2.6.26/drivers/scsi/qla2xxx/qla_os.c 2008-07-14 01:51:29.000000000 +0400
+++ linux-2.6.26/drivers/scsi/qla2xxx/qla_os.c 2008-07-24 10:13:45.000000000 +0400
@@ -1632,6 +1630,8 @@ qla2x00_probe_one(struct pci_dev *pdev,
/* load the F/W, read paramaters, and init the H/W */
ha->instance = num_hosts;
+ spin_lock_init(&ha->dpc_lock);
+
mutex_init(&ha->vport_lock);
init_completion(&ha->mbx_cmd_comp);
complete(&ha->mbx_cmd_comp);
@@ -1764,6 +1770,26 @@ qla2x00_remove_one(struct pci_dev *pdev)
}
static void
+qla2x00_stop_dpc_thread(scsi_qla_host_t *ha)
+{
+ struct task_struct *t = NULL;
+
+ spin_lock_irq(&ha->dpc_lock);
+ if (ha->dpc_thread != NULL) {
+ t = ha->dpc_thread;
+ /*
+ * qla2xxx_wake_dpc checks for ->dpc_thread
+ * so we need to zero it out.
+ */
+ ha->dpc_thread = NULL;
+ }
+ spin_unlock_irq(&ha->dpc_lock);
+
+ if (t != NULL)
+ kthread_stop(t);
+}
+
+static void
qla2x00_free_device(scsi_qla_host_t *ha)
{
qla2x00_abort_all_cmds(ha, DID_NO_CONNECT << 16);
@@ -1775,16 +1801,7 @@ qla2x00_free_device(scsi_qla_host_t *ha)
ha->flags.online = 0;
/* Kill the kernel thread for this host */
- if (ha->dpc_thread) {
- struct task_struct *t = ha->dpc_thread;
-
- /*
- * qla2xxx_wake_dpc checks for ->dpc_thread
- * so we need to zero it out.
- */
- ha->dpc_thread = NULL;
- kthread_stop(t);
- }
+ qla2x00_stop_dpc_thread(ha);
if (ha->flags.fce_enabled)
qla2x00_disable_fce_trace(ha, NULL, NULL);
@@ -2427,8 +2444,11 @@ qla2x00_do_dpc(void *data)
void
qla2xxx_wake_dpc(scsi_qla_host_t *ha)
{
+ unsigned long flags;
+ spin_lock_irqsave(&ha->dpc_lock, flags);
if (ha->dpc_thread)
wake_up_process(ha->dpc_thread);
+ spin_unlock_irqrestore(&ha->dpc_lock, flags);
}
/*
--
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