IB/srp: Avoid duplicate connections
The connection uniqueness check is performed before a new connection
is added to the target list. This patch protects both actions by a
mutex such that simultaneous writes from two different threads into the
"add_target" variable do not result in duplicate connections.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 2ec9c05..3294f10 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -2614,6 +2614,8 @@
target->tl_retry_count = 7;
target->queue_size = SRP_DEFAULT_QUEUE_SIZE;
+ mutex_lock(&host->add_target_mutex);
+
ret = srp_parse_options(buf, target);
if (ret)
goto err;
@@ -2682,7 +2684,11 @@
be64_to_cpu(target->service_id),
target->path.sgid.raw, target->path.dgid.raw);
- return count;
+ ret = count;
+
+out:
+ mutex_unlock(&host->add_target_mutex);
+ return ret;
err_disconnect:
srp_disconnect_target(target);
@@ -2698,8 +2704,7 @@
err:
scsi_host_put(target_host);
-
- return ret;
+ goto out;
}
static DEVICE_ATTR(add_target, S_IWUSR, NULL, srp_create_target);
@@ -2735,6 +2740,7 @@
INIT_LIST_HEAD(&host->target_list);
spin_lock_init(&host->target_lock);
init_completion(&host->released);
+ mutex_init(&host->add_target_mutex);
host->srp_dev = device;
host->port = port;