iser-target: Fix command leak for tx_desc->comp_llnode_batch

This patch addresses a number of active I/O shutdown issues
related to isert_cmd descriptors being leaked that are part
of a completion interrupt coalescing batch.

This includes adding logic in isert_cq_tx_comp_err() to
drain any associated tx_desc->comp_llnode_batch, as well
as isert_cq_drain_comp_llist() to drain any associated
isert_conn->conn_comp_llist.

Also, set tx_desc->llnode_active in isert_init_send_wr()
in order to determine when work requests need to be skipped
in isert_cq_tx_work() exception path code.

Finally, update isert_init_send_wr() to only allow interrupt
coalescing when ISER_CONN_UP.

Acked-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org> #3.13+
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 614a6ef6a79d7c9a9a028b46c35da5834a58f110..8ee228e9ab5aa28b85ee2893a92b3ab243c35388 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -497,7 +497,6 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
        kref_init(&isert_conn->conn_kref);
        kref_get(&isert_conn->conn_kref);
        mutex_init(&isert_conn->conn_mutex);
-       mutex_init(&isert_conn->conn_comp_mutex);
        spin_lock_init(&isert_conn->conn_lock);
 
        cma_id->context = isert_conn;
@@ -888,16 +887,17 @@ isert_init_send_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
         * Coalesce send completion interrupts by only setting IB_SEND_SIGNALED
         * bit for every ISERT_COMP_BATCH_COUNT number of ib_post_send() calls.
         */
-       mutex_lock(&isert_conn->conn_comp_mutex);
-       if (coalesce &&
+       mutex_lock(&isert_conn->conn_mutex);
+       if (coalesce && isert_conn->state == ISER_CONN_UP &&
            ++isert_conn->conn_comp_batch < ISERT_COMP_BATCH_COUNT) {
+               tx_desc->llnode_active = true;
                llist_add(&tx_desc->comp_llnode, &isert_conn->conn_comp_llist);
-               mutex_unlock(&isert_conn->conn_comp_mutex);
+               mutex_unlock(&isert_conn->conn_mutex);
                return;
        }
        isert_conn->conn_comp_batch = 0;
        tx_desc->comp_llnode_batch = llist_del_all(&isert_conn->conn_comp_llist);
-       mutex_unlock(&isert_conn->conn_comp_mutex);
+       mutex_unlock(&isert_conn->conn_mutex);
 
        send_wr->send_flags = IB_SEND_SIGNALED;
 }
@@ -1692,11 +1692,46 @@ isert_send_completion(struct iser_tx_desc *tx_desc,
        __isert_send_completion(tx_desc, isert_conn);
 }
 
+static void
+isert_cq_drain_comp_llist(struct isert_conn *isert_conn, struct ib_device *ib_dev)
+{
+       struct llist_node *llnode;
+       struct isert_rdma_wr *wr;
+       struct iser_tx_desc *t;
+
+       mutex_lock(&isert_conn->conn_mutex);
+       llnode = llist_del_all(&isert_conn->conn_comp_llist);
+       isert_conn->conn_comp_batch = 0;
+       mutex_unlock(&isert_conn->conn_mutex);
+
+       while (llnode) {
+               t = llist_entry(llnode, struct iser_tx_desc, comp_llnode);
+               llnode = llist_next(llnode);
+               wr = &t->isert_cmd->rdma_wr;
+
+               atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+               isert_completion_put(t, t->isert_cmd, ib_dev);
+       }
+}
+
 static void
 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;
+       struct llist_node *llnode = tx_desc->comp_llnode_batch;
+       struct isert_rdma_wr *wr;
+       struct iser_tx_desc *t;
+
+       while (llnode) {
+               t = llist_entry(llnode, struct iser_tx_desc, comp_llnode);
+               llnode = llist_next(llnode);
+               wr = &t->isert_cmd->rdma_wr;
+
+               atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
+               isert_completion_put(t, t->isert_cmd, ib_dev);
+       }
+       tx_desc->comp_llnode_batch = NULL;
 
        if (!isert_cmd)
                isert_unmap_tx_desc(tx_desc, ib_dev);
@@ -1713,6 +1748,8 @@ isert_cq_rx_comp_err(struct isert_conn *isert_conn)
        if (isert_conn->post_recv_buf_count)
                return;
 
+       isert_cq_drain_comp_llist(isert_conn, ib_dev);
+
        if (conn->sess) {
                target_sess_cmd_list_set_waiting(conn->sess->se_sess);
                target_wait_for_sess_cmds(conn->sess->se_sess);
@@ -1752,6 +1789,9 @@ isert_cq_tx_work(struct work_struct *work)
                        pr_debug("TX wc.vendor_err: 0x%08x\n", wc.vendor_err);
 
                        if (wc.wr_id != ISER_FASTREG_LI_WRID) {
+                               if (tx_desc->llnode_active)
+                                       continue;
+
                                atomic_dec(&isert_conn->post_send_buf_count);
                                isert_cq_tx_comp_err(tx_desc, isert_conn);
                        }

diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index 10be55a3185e7280e4eb79482d4ba17ae7650145..f6ae7f5dd4082768f3b6f0dfb36c1d45506b5eb6 100644 (file)
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -46,6 +46,7 @@ struct iser_tx_desc {
        struct isert_cmd *isert_cmd;
        struct llist_node *comp_llnode_batch;
        struct llist_node comp_llnode;
+       bool            llnode_active;
        struct ib_send_wr send_wr;
 } __packed;
 
@@ -127,7 +128,6 @@ struct isert_conn {
 #define ISERT_COMP_BATCH_COUNT 8
        int                     conn_comp_batch;
        struct llist_head       conn_comp_llist;
-       struct mutex            conn_comp_mutex;
 };
 
 #define ISERT_MAX_CQ 64