Target/iscsi,iser: Avoid accepting transport connections during stop stage

When the target is in stop stage, iSER transport initiates RDMA disconnects.
The iSER initiator may wish to establish a new connection over the
still existing network portal. In this case iSER transport should not
accept and resume new RDMA connections. In order to learn that, iscsi_np
is added with enabled flag so the iSER transport can check when deciding
weather to accept and resume a new connection request.

The iscsi_np is enabled after successful transport setup, and disabled
before iscsi_np login threads are cleaned up.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

4 files changed, 13 insertions, 1 deletions

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 826eaf5741f6..a1710465faaf 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -562,7 +562,15 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
         struct isert_device *device;
         struct ib_device *ib_dev = cma_id->device;
         int ret = 0;
-        u8 pi_support = np->tpg_np->tpg->tpg_attrib.t10_pi;
+        u8 pi_support;
+
+        spin_lock_bh(&np->np_thread_lock);
+        if (!np->enabled) {
+                spin_unlock_bh(&np->np_thread_lock);
+                pr_debug("iscsi_np is not enabled, reject connect request\n");
+                return rdma_reject(cma_id, NULL, 0);
+        }
+        spin_unlock_bh(&np->np_thread_lock);
 
         pr_debug("Entering isert_connect_request cma_id: %p, context: %p\n",
                  cma_id, cma_id->context);
@@ -653,6 +661,7 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
                 goto out_mr;
         }
 
+        pi_support = np->tpg_np->tpg->tpg_attrib.t10_pi;
         if (pi_support && !device->pi_capable) {
                 pr_err("Protection information requested but not supported\n");
                 ret = -EINVAL;
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index 6960f22909ae..302eb3b78715 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -775,6 +775,7 @@ struct iscsi_np {
         int                     np_ip_proto;
         int                     np_sock_type;
         enum np_thread_state_table np_thread_state;
+        bool                    enabled;
         enum iscsi_timer_flags_table np_login_timer_flags;
         u32                     np_exports;
         enum np_flags_table     np_flags;
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 8739b98f6f93..b72d8550e8bc 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -984,6 +984,7 @@ int iscsi_target_setup_login_socket(
         }
 
         np->np_transport = t;
+        np->enabled = true;
         return 0;
 }
 
diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
index eb96b20dc09e..ca1811858afd 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -184,6 +184,7 @@ static void iscsit_clear_tpg_np_login_thread(
                 return;
         }
 
+        tpg_np->tpg_np->enabled = false;
         iscsit_reset_np_thread(tpg_np->tpg_np, tpg_np, tpg, shutdown);
 }