From: root <vladimirn@xxxxxxxxxxxx>
Under heavy iser target(scst) start/stop stress on iser intitiator
side found race condition. When called function iscsi_iser_slave_alloc
iser_conn pointer could be NULL. Because function iscsi_iser_conn_stop
can be called before and free iser connection. Addition global mutex
help to avoid this race.
Signed-off-by: Vladimir Neyelov <vladimirn@xxxxxxxxxxxx>
---
drivers/infiniband/ulp/iser/iscsi_iser.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 5a887ef..62fff2a 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -83,6 +83,7 @@
static struct iscsi_transport iscsi_iser_transport;
static struct scsi_transport_template *iscsi_iser_scsi_transport;
static struct workqueue_struct *release_wq;
+static DEFINE_MUTEX(unbind_iser_conn_mutex);
struct iser_global ig;
int iser_debug_level = 0;
@@ -550,12 +551,14 @@ static void iscsi_iser_cleanup_task(struct iscsi_task *task)
*/
if (iser_conn) {
mutex_lock(&iser_conn->state_mutex);
+ mutex_lock(&unbind_iser_conn_mutex);
iser_conn_terminate(iser_conn);
iscsi_conn_stop(cls_conn, flag);
/* unbind */
iser_conn->iscsi_conn = NULL;
conn->dd_data = NULL;
+ mutex_unlock(&unbind_iser_conn_mutex);
complete(&iser_conn->stop_completion);
mutex_unlock(&iser_conn->state_mutex);
@@ -977,13 +980,20 @@ static int iscsi_iser_slave_alloc(struct scsi_device *sdev)
struct iser_conn *iser_conn;
struct ib_device *ib_dev;
+ mutex_lock(&unbind_iser_conn_mutex);
+
session = starget_to_session(scsi_target(sdev))->dd_data;
iser_conn = session->leadconn->dd_data;
+ if(!iser_conn) {
+ mutex_unlock(&unbind_iser_conn_mutex);
+ return -EFAULT;
+ }
ib_dev = iser_conn->ib_conn.device->ib_device;
if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG))
blk_queue_virt_boundary(sdev->request_queue, ~MASK_4K);
+ mutex_unlock(&unbind_iser_conn_mutex);
return 0;
}
--
1.8.4.3
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