IB/iser: DMA unmap TX bufs used for iSCSI/iSER headers

The current driver never does DMA unmapping on these buffers.  Fix that
by adding DMA unmapping to the task cleanup callback, and DMA mapping to
the task init function (drop the headers_initialized micro-optimization).

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

2 files changed, 8 insertions, 4 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 84e8c293a715..c42b8f390c0b 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -151,7 +151,6 @@ int iser_initialize_task_headers(struct iscsi_task *task,
         tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
         tx_desc->tx_sg[0].lkey   = device->mr->lkey;
 
-        iser_task->headers_initialized  = 1;
         iser_task->iser_conn            = iser_conn;
         return 0;
 }
@@ -166,8 +165,7 @@ iscsi_iser_task_init(struct iscsi_task *task)
 {
         struct iscsi_iser_task *iser_task = task->dd_data;
 
-        if (!iser_task->headers_initialized)
-                if (iser_initialize_task_headers(task, &iser_task->desc))
+        if (iser_initialize_task_headers(task, &iser_task->desc))
                         return -ENOMEM;
 
         /* mgmt task */
@@ -278,6 +276,13 @@ iscsi_iser_task_xmit(struct iscsi_task *task)
 static void iscsi_iser_cleanup_task(struct iscsi_task *task)
 {
         struct iscsi_iser_task *iser_task = task->dd_data;
+        struct iser_tx_desc     *tx_desc = &iser_task->desc;
+
+        struct iscsi_iser_conn *iser_conn = task->conn->dd_data;
+        struct iser_device     *device    = iser_conn->ib_conn->device;
+
+        ib_dma_unmap_single(device->ib_device,
+                tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 
         /* mgmt tasks do not need special cleanup */
         if (!task->sc)
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index 2982a14a0557..db7ea3704da7 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -278,7 +278,6 @@ struct iscsi_iser_task {
         struct iser_regd_buf         rdma_regd[ISER_DIRS_NUM];/* regd rdma buf */
         struct iser_data_buf         data[ISER_DIRS_NUM];     /* orig. data des*/
         struct iser_data_buf         data_copy[ISER_DIRS_NUM];/* contig. copy  */
-        int                          headers_initialized;
 };
 
 struct iser_page_vec {