iscsi/iser-target: Fix isert_conn->state hung shutdown issues

This patch addresses a couple of different hug shutdown issues
related to wait_event() + isert_conn->state.  First, it changes
isert_conn->conn_wait + isert_conn->conn_wait_comp_err from
waitqueues to completions, and sets ISER_CONN_TERMINATING from
within isert_disconnect_work().

Second, it splits isert_free_conn() into isert_wait_conn() that
is called earlier in iscsit_close_connection() to ensure that
all outstanding commands have completed before continuing.

Finally, it breaks isert_cq_comp_err() into seperate TX / RX
related code, and adds logic in isert_cq_rx_comp_err() to wait
for outstanding commands to complete before setting ISER_CONN_DOWN
and calling complete(&isert_conn->conn_wait_comp_err).

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

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 5eb2b88cf94739fae0afacc20d094824db145d7d..862d7b4b0411ad837b3f87fe36bee6e6c4e4e24d 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -492,8 +492,8 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
        isert_conn->state = ISER_CONN_INIT;
        INIT_LIST_HEAD(&isert_conn->conn_accept_node);
        init_completion(&isert_conn->conn_login_comp);
-       init_waitqueue_head(&isert_conn->conn_wait);
-       init_waitqueue_head(&isert_conn->conn_wait_comp_err);
+       init_completion(&isert_conn->conn_wait);
+       init_completion(&isert_conn->conn_wait_comp_err);
        kref_init(&isert_conn->conn_kref);
        kref_get(&isert_conn->conn_kref);
        mutex_init(&isert_conn->conn_mutex);
@@ -688,11 +688,11 @@ isert_disconnect_work(struct work_struct *work)
 
        pr_debug("isert_disconnect_work(): >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
        mutex_lock(&isert_conn->conn_mutex);
-       isert_conn->state = ISER_CONN_DOWN;
+       if (isert_conn->state == ISER_CONN_UP)
+               isert_conn->state = ISER_CONN_TERMINATING;
 
        if (isert_conn->post_recv_buf_count == 0 &&
            atomic_read(&isert_conn->post_send_buf_count) == 0) {
-               pr_debug("Calling wake_up(&isert_conn->conn_wait);\n");
                mutex_unlock(&isert_conn->conn_mutex);
                goto wake_up;
        }
@@ -712,7 +712,7 @@ isert_disconnect_work(struct work_struct *work)
        mutex_unlock(&isert_conn->conn_mutex);
 
 wake_up:
-       wake_up(&isert_conn->conn_wait);
+       complete(&isert_conn->conn_wait);
        isert_put_conn(isert_conn);
 }
 
@@ -1589,7 +1589,7 @@ isert_do_control_comp(struct work_struct *work)
                pr_debug("Calling iscsit_logout_post_handler >>>>>>>>>>>>>>\n");
                /*
                 * Call atomic_dec(&isert_conn->post_send_buf_count)
-                * from isert_free_conn()
+                * from isert_wait_conn()
                 */
                isert_conn->logout_posted = true;
                iscsit_logout_post_handler(cmd, cmd->conn);
@@ -1691,31 +1691,39 @@ isert_send_completion(struct iser_tx_desc *tx_desc,
 }
 
 static void
-isert_cq_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn)
+isert_cq_tx_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn)
 {
        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+       struct isert_cmd *isert_cmd = tx_desc->isert_cmd;
+
+       if (!isert_cmd)
+               isert_unmap_tx_desc(tx_desc, ib_dev);
+       else
+               isert_completion_put(tx_desc, isert_cmd, ib_dev);
+}
+
+static void
+isert_cq_rx_comp_err(struct isert_conn *isert_conn)
+{
+       struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+       struct iscsi_conn *conn = isert_conn->conn;
 
-       if (tx_desc) {
-               struct isert_cmd *isert_cmd = tx_desc->isert_cmd;
+       if (isert_conn->post_recv_buf_count)
+               return;
 
-               if (!isert_cmd)
-                       isert_unmap_tx_desc(tx_desc, ib_dev);
-               else
-                       isert_completion_put(tx_desc, isert_cmd, ib_dev);
+       if (conn->sess) {
+               target_sess_cmd_list_set_waiting(conn->sess->se_sess);
+               target_wait_for_sess_cmds(conn->sess->se_sess);
        }
 
-       if (isert_conn->post_recv_buf_count == 0 &&
-           atomic_read(&isert_conn->post_send_buf_count) == 0) {
-               pr_debug("isert_cq_comp_err >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");
-               pr_debug("Calling wake_up from isert_cq_comp_err\n");
+       while (atomic_read(&isert_conn->post_send_buf_count))
+               msleep(3000);
 
-               mutex_lock(&isert_conn->conn_mutex);
-               if (isert_conn->state != ISER_CONN_DOWN)
-                       isert_conn->state = ISER_CONN_TERMINATING;
-               mutex_unlock(&isert_conn->conn_mutex);
+       mutex_lock(&isert_conn->conn_mutex);
+       isert_conn->state = ISER_CONN_DOWN;
+       mutex_unlock(&isert_conn->conn_mutex);
 
-               wake_up(&isert_conn->conn_wait_comp_err);
-       }
+       complete(&isert_conn->conn_wait_comp_err);
 }
 
 static void
@@ -1740,8 +1748,9 @@ isert_cq_tx_work(struct work_struct *work)
                        pr_debug("TX wc.status != IB_WC_SUCCESS >>>>>>>>>>>>>>\n");
                        pr_debug("TX wc.status: 0x%08x\n", wc.status);
                        pr_debug("TX wc.vendor_err: 0x%08x\n", wc.vendor_err);
+
                        atomic_dec(&isert_conn->post_send_buf_count);
-                       isert_cq_comp_err(tx_desc, isert_conn);
+                       isert_cq_tx_comp_err(tx_desc, isert_conn);
                }
        }
 
@@ -1784,7 +1793,7 @@ isert_cq_rx_work(struct work_struct *work)
                                         wc.vendor_err);
                        }
                        isert_conn->post_recv_buf_count--;
-                       isert_cq_comp_err(NULL, isert_conn);
+                       isert_cq_rx_comp_err(isert_conn);
                }
        }
 
@@ -2702,22 +2711,11 @@ isert_free_np(struct iscsi_np *np)
        kfree(isert_np);
 }
 
-static int isert_check_state(struct isert_conn *isert_conn, int state)
-{
-       int ret;
-
-       mutex_lock(&isert_conn->conn_mutex);
-       ret = (isert_conn->state == state);
-       mutex_unlock(&isert_conn->conn_mutex);
-
-       return ret;
-}
-
-static void isert_free_conn(struct iscsi_conn *conn)
+static void isert_wait_conn(struct iscsi_conn *conn)
 {
        struct isert_conn *isert_conn = conn->context;
 
-       pr_debug("isert_free_conn: Starting \n");
+       pr_debug("isert_wait_conn: Starting \n");
        /*
         * Decrement post_send_buf_count for special case when called
         * from isert_do_control_comp() -> iscsit_logout_post_handler()
@@ -2727,38 +2725,29 @@ static void isert_free_conn(struct iscsi_conn *conn)
                atomic_dec(&isert_conn->post_send_buf_count);
 
        if (isert_conn->conn_cm_id && isert_conn->state != ISER_CONN_DOWN) {
-               pr_debug("Calling rdma_disconnect from isert_free_conn\n");
+               pr_debug("Calling rdma_disconnect from isert_wait_conn\n");
                rdma_disconnect(isert_conn->conn_cm_id);
        }
        /*
         * Only wait for conn_wait_comp_err if the isert_conn made it
         * into full feature phase..
         */
-       if (isert_conn->state == ISER_CONN_UP) {
-               pr_debug("isert_free_conn: Before wait_event comp_err %d\n",
-                        isert_conn->state);
-               mutex_unlock(&isert_conn->conn_mutex);
-
-               wait_event(isert_conn->conn_wait_comp_err,
-                         (isert_check_state(isert_conn, ISER_CONN_TERMINATING)));
-
-               wait_event(isert_conn->conn_wait,
-                         (isert_check_state(isert_conn, ISER_CONN_DOWN)));
-
-               isert_put_conn(isert_conn);
-               return;
-       }
        if (isert_conn->state == ISER_CONN_INIT) {
                mutex_unlock(&isert_conn->conn_mutex);
-               isert_put_conn(isert_conn);
                return;
        }
-       pr_debug("isert_free_conn: wait_event conn_wait %d\n",
-                isert_conn->state);
+       if (isert_conn->state == ISER_CONN_UP)
+               isert_conn->state = ISER_CONN_TERMINATING;
        mutex_unlock(&isert_conn->conn_mutex);
 
-       wait_event(isert_conn->conn_wait,
-                 (isert_check_state(isert_conn, ISER_CONN_DOWN)));
+       wait_for_completion(&isert_conn->conn_wait_comp_err);
+
+       wait_for_completion(&isert_conn->conn_wait);
+}
+
+static void isert_free_conn(struct iscsi_conn *conn)
+{
+       struct isert_conn *isert_conn = conn->context;
 
        isert_put_conn(isert_conn);
 }
@@ -2771,6 +2760,7 @@ static struct iscsit_transport iser_target_transport = {
        .iscsit_setup_np        = isert_setup_np,
        .iscsit_accept_np       = isert_accept_np,
        .iscsit_free_np         = isert_free_np,
+       .iscsit_wait_conn       = isert_wait_conn,
        .iscsit_free_conn       = isert_free_conn,
        .iscsit_get_login_rx    = isert_get_login_rx,
        .iscsit_put_login_tx    = isert_put_login_tx,

diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index 708a069002f3530e00002c5d1e454c1823119bb4..41e799ff8ecc4cb079acea64486a040f256255a2 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -116,8 +116,8 @@ struct isert_conn {
        struct isert_device     *conn_device;
        struct work_struct      conn_logout_work;
        struct mutex            conn_mutex;
-       wait_queue_head_t       conn_wait;
-       wait_queue_head_t       conn_wait_comp_err;
+       struct completion       conn_wait;
+       struct completion       conn_wait_comp_err;
        struct kref             conn_kref;
        struct list_head        conn_fr_pool;
        int                     conn_fr_pool_size;

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index ece82b0d8ea3ee09392042fbbf05460be2e779a2..b83ec378d04f8f1ed5fbc820429c6f1657b4d7a0 100644 (file)
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -4196,6 +4196,10 @@ int iscsit_close_connection(
        iscsit_stop_timers_for_cmds(conn);
        iscsit_stop_nopin_response_timer(conn);
        iscsit_stop_nopin_timer(conn);
+
+       if (conn->conn_transport->iscsit_wait_conn)
+               conn->conn_transport->iscsit_wait_conn(conn);
+
        iscsit_free_queue_reqs_for_conn(conn);
 
        /*

diff --git a/include/target/iscsi/iscsi_transport.h b/include/target/iscsi/iscsi_transport.h
index ae5a17111968c7ca8bc8667a65d16393532ffbde..4483fadfa68d8fdc744743d6bc5bcd52de301608 100644 (file)
--- a/include/target/iscsi/iscsi_transport.h
+++ b/include/target/iscsi/iscsi_transport.h
@@ -12,6 +12,7 @@ struct iscsit_transport {
        int (*iscsit_setup_np)(struct iscsi_np *, struct __kernel_sockaddr_storage *);
        int (*iscsit_accept_np)(struct iscsi_np *, struct iscsi_conn *);
        void (*iscsit_free_np)(struct iscsi_np *);
+       void (*iscsit_wait_conn)(struct iscsi_conn *);
        void (*iscsit_free_conn)(struct iscsi_conn *);
        int (*iscsit_get_login_rx)(struct iscsi_conn *, struct iscsi_login *);
        int (*iscsit_put_login_tx)(struct iscsi_conn *, struct iscsi_login *, u32);