5 files changed, 68 insertions, 33 deletions

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index afab32376126..202a42858f25 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -3998,7 +3998,13 @@ get_immediate:
         }
 
 transport_err:
-        iscsit_take_action_for_connection_exit(conn);
+        /*
+         * Avoid the normal connection failure code-path if this connection
+         * is still within LOGIN mode, and iscsi_np process context is
+         * responsible for cleaning up the early connection failure.
+         */
+        if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
+                iscsit_take_action_for_connection_exit(conn);
 out:
         return 0;
 }
@@ -4082,7 +4088,7 @@ reject:
 
 int iscsi_target_rx_thread(void *arg)
 {
-        int ret;
+        int ret, rc;
         u8 buffer[ISCSI_HDR_LEN], opcode;
         u32 checksum = 0, digest = 0;
         struct iscsi_conn *conn = arg;
@@ -4092,10 +4098,16 @@ int iscsi_target_rx_thread(void *arg)
          * connection recovery / failure event can be triggered externally.
          */
         allow_signal(SIGINT);
+        /*
+         * Wait for iscsi_post_login_handler() to complete before allowing
+         * incoming iscsi/tcp socket I/O, and/or failing the connection.
+         */
+        rc = wait_for_completion_interruptible(&conn->rx_login_comp);
+        if (rc < 0)
+                return 0;
 
         if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {
                 struct completion comp;
-                int rc;
 
                 init_completion(&comp);
                 rc = wait_for_completion_interruptible(&comp);
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 3d0fe4ff5590..7e8f65e5448f 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -82,6 +82,7 @@ static struct iscsi_login *iscsi_login_init_conn(struct iscsi_conn *conn)
         init_completion(&conn->conn_logout_comp);
         init_completion(&conn->rx_half_close_comp);
         init_completion(&conn->tx_half_close_comp);
+        init_completion(&conn->rx_login_comp);
         spin_lock_init(&conn->cmd_lock);
         spin_lock_init(&conn->conn_usage_lock);
         spin_lock_init(&conn->immed_queue_lock);
@@ -644,7 +645,7 @@ static void iscsi_post_login_start_timers(struct iscsi_conn *conn)
                 iscsit_start_nopin_timer(conn);
 }
 
-static int iscsit_start_kthreads(struct iscsi_conn *conn)
+int iscsit_start_kthreads(struct iscsi_conn *conn)
 {
         int ret = 0;
 
@@ -679,6 +680,7 @@ static int iscsit_start_kthreads(struct iscsi_conn *conn)
 
         return 0;
 out_tx:
+        send_sig(SIGINT, conn->tx_thread, 1);
         kthread_stop(conn->tx_thread);
         conn->tx_thread_active = false;
 out_bitmap:
@@ -689,7 +691,7 @@ out_bitmap:
         return ret;
 }
 
-int iscsi_post_login_handler(
+void iscsi_post_login_handler(
         struct iscsi_np *np,
         struct iscsi_conn *conn,
         u8 zero_tsih)
@@ -699,7 +701,6 @@ int iscsi_post_login_handler(
         struct se_session *se_sess = sess->se_sess;
         struct iscsi_portal_group *tpg = sess->tpg;
         struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
-        int rc;
 
         iscsit_inc_conn_usage_count(conn);
 
@@ -739,10 +740,6 @@ int iscsi_post_login_handler(
                         sess->sess_ops->InitiatorName);
                 spin_unlock_bh(&sess->conn_lock);
 
-                rc = iscsit_start_kthreads(conn);
-                if (rc)
-                        return rc;
-
                 iscsi_post_login_start_timers(conn);
                 /*
                  * Determine CPU mask to ensure connection's RX and TX kthreads
@@ -751,15 +748,20 @@ int iscsi_post_login_handler(
                 iscsit_thread_get_cpumask(conn);
                 conn->conn_rx_reset_cpumask = 1;
                 conn->conn_tx_reset_cpumask = 1;
-
+                /*
+                 * Wakeup the sleeping iscsi_target_rx_thread() now that
+                 * iscsi_conn is in TARG_CONN_STATE_LOGGED_IN state.
+                 */
+                complete(&conn->rx_login_comp);
                 iscsit_dec_conn_usage_count(conn);
+
                 if (stop_timer) {
                         spin_lock_bh(&se_tpg->session_lock);
                         iscsit_stop_time2retain_timer(sess);
                         spin_unlock_bh(&se_tpg->session_lock);
                 }
                 iscsit_dec_session_usage_count(sess);
-                return 0;
+                return;
         }
 
         iscsi_set_session_parameters(sess->sess_ops, conn->param_list, 1);
@@ -800,10 +802,6 @@ int iscsi_post_login_handler(
                 " iSCSI Target Portal Group: %hu\n", tpg->nsessions, tpg->tpgt);
         spin_unlock_bh(&se_tpg->session_lock);
 
-        rc = iscsit_start_kthreads(conn);
-        if (rc)
-                return rc;
-
         iscsi_post_login_start_timers(conn);
         /*
          * Determine CPU mask to ensure connection's RX and TX kthreads
@@ -812,10 +810,12 @@ int iscsi_post_login_handler(
         iscsit_thread_get_cpumask(conn);
         conn->conn_rx_reset_cpumask = 1;
         conn->conn_tx_reset_cpumask = 1;
-
+        /*
+         * Wakeup the sleeping iscsi_target_rx_thread() now that
+         * iscsi_conn is in TARG_CONN_STATE_LOGGED_IN state.
+         */
+        complete(&conn->rx_login_comp);
         iscsit_dec_conn_usage_count(conn);
-
-        return 0;
 }
 
 static void iscsi_handle_login_thread_timeout(unsigned long data)
@@ -1380,23 +1380,12 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
         if (ret < 0)
                 goto new_sess_out;
 
-        if (!conn->sess) {
-                pr_err("struct iscsi_conn session pointer is NULL!\n");
-                goto new_sess_out;
-        }
-
         iscsi_stop_login_thread_timer(np);
 
-        if (signal_pending(current))
-                goto new_sess_out;
-
         if (ret == 1) {
                 tpg_np = conn->tpg_np;
 
-                ret = iscsi_post_login_handler(np, conn, zero_tsih);
-                if (ret < 0)
-                        goto new_sess_out;
-
+                iscsi_post_login_handler(np, conn, zero_tsih);
                 iscsit_deaccess_np(np, tpg, tpg_np);
         }
 
diff --git a/drivers/target/iscsi/iscsi_target_login.h b/drivers/target/iscsi/iscsi_target_login.h
index 1c7358081533..57aa0d0fd820 100644
--- a/drivers/target/iscsi/iscsi_target_login.h
+++ b/drivers/target/iscsi/iscsi_target_login.h
@@ -12,7 +12,8 @@ extern int iscsit_accept_np(struct iscsi_np *, struct iscsi_conn *);
 extern int iscsit_get_login_rx(struct iscsi_conn *, struct iscsi_login *);
 extern int iscsit_put_login_tx(struct iscsi_conn *, struct iscsi_login *, u32);
 extern void iscsit_free_conn(struct iscsi_np *, struct iscsi_conn *);
-extern int iscsi_post_login_handler(struct iscsi_np *, struct iscsi_conn *, u8);
+extern int iscsit_start_kthreads(struct iscsi_conn *);
+extern void iscsi_post_login_handler(struct iscsi_np *, struct iscsi_conn *, u8);
 extern void iscsi_target_login_sess_out(struct iscsi_conn *, struct iscsi_np *,
                                 bool, bool);
 extern int iscsi_target_login_thread(void *);
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index 8c02fa34716f..f9cde9141836 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -17,6 +17,7 @@
  ******************************************************************************/
 
 #include <linux/ctype.h>
+#include <linux/kthread.h>
 #include <scsi/iscsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>
@@ -361,10 +362,24 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
                 ntohl(login_rsp->statsn), login->rsp_length);
 
         padding = ((-login->rsp_length) & 3);
+        /*
+         * Before sending the last login response containing the transition
+         * bit for full-feature-phase, go ahead and start up TX/RX threads
+         * now to avoid potential resource allocation failures after the
+         * final login response has been sent.
+         */
+        if (login->login_complete) {
+                int rc = iscsit_start_kthreads(conn);
+                if (rc) {
+                        iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
+                                            ISCSI_LOGIN_STATUS_NO_RESOURCES);
+                        return -1;
+                }
+        }
 
         if (conn->conn_transport->iscsit_put_login_tx(conn, login,
                                         login->rsp_length + padding) < 0)
-                return -1;
+                goto err;
 
         login->rsp_length               = 0;
         mutex_lock(&sess->cmdsn_mutex);
@@ -373,6 +388,23 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
         mutex_unlock(&sess->cmdsn_mutex);
 
         return 0;
+
+err:
+        if (login->login_complete) {
+                if (conn->rx_thread && conn->rx_thread_active) {
+                        send_sig(SIGINT, conn->rx_thread, 1);
+                        kthread_stop(conn->rx_thread);
+                }
+                if (conn->tx_thread && conn->tx_thread_active) {
+                        send_sig(SIGINT, conn->tx_thread, 1);
+                        kthread_stop(conn->tx_thread);
+                }
+                spin_lock(&iscsit_global->ts_bitmap_lock);
+                bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
+                                      get_order(1));
+                spin_unlock(&iscsit_global->ts_bitmap_lock);
+        }
+        return -1;
 }
 
 static void iscsi_target_sk_data_ready(struct sock *sk)
diff --git a/include/target/iscsi/iscsi_target_core.h b/include/target/iscsi/iscsi_target_core.h
index 34117b8b72e4..0aedbb2c10e0 100644
--- a/include/target/iscsi/iscsi_target_core.h
+++ b/include/target/iscsi/iscsi_target_core.h
@@ -595,6 +595,7 @@ struct iscsi_conn {
         int                     bitmap_id;
         int                     rx_thread_active;
         struct task_struct      *rx_thread;
+        struct completion       rx_login_comp;
         int                     tx_thread_active;
         struct task_struct      *tx_thread;
         /* list_head for session connection list */