diff options
Diffstat (limited to 'drivers/target/target_core_transport.c')
| -rw-r--r-- | drivers/target/target_core_transport.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index efac6a9a7438..9cc49d1b5b1f 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -4044,8 +4044,6 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) if (!task->task_sg) continue; - BUG_ON(!task->task_padded_sg); - if (!sg_first) { sg_first = task->task_sg; chained_nents = task->task_sg_nents; @@ -4053,9 +4051,19 @@ void transport_do_task_sg_chain(struct se_cmd *cmd) sg_chain(sg_prev, sg_prev_nents, task->task_sg); chained_nents += task->task_sg_nents; } + /* + * For the padded tasks, use the extra SGL vector allocated + * in transport_allocate_data_tasks() for the sg_prev_nents + * offset into sg_chain() above.. The last task of a + * multi-task list, or a single task will not have + * task->task_sg_padded set.. + */ + if (task->task_padded_sg) + sg_prev_nents = (task->task_sg_nents + 1); + else + sg_prev_nents = task->task_sg_nents; sg_prev = task->task_sg; - sg_prev_nents = task->task_sg_nents; } /* * Setup the starting pointer and total t_tasks_sg_linked_no including @@ -4107,7 +4115,7 @@ static int transport_allocate_data_tasks( cmd_sg = sgl; for (i = 0; i < task_count; i++) { - unsigned int task_size; + unsigned int task_size, task_sg_nents_padded; int count; task = transport_generic_get_task(cmd, data_direction); @@ -4135,24 +4143,24 @@ static int transport_allocate_data_tasks( * Check if the fabric module driver is requesting that all * struct se_task->task_sg[] be chained together.. If so, * then allocate an extra padding SG entry for linking and - * marking the end of the chained SGL. - * Possibly over-allocate task sgl size by using cmd sgl size. - * It's so much easier and only a waste when task_count > 1. - * That is extremely rare. + * marking the end of the chained SGL for every task except + * the last one for (task_count > 1) operation, or skipping + * the extra padding for the (task_count == 1) case. */ - if (cmd->se_tfo->task_sg_chaining) { - task->task_sg_nents++; + if (cmd->se_tfo->task_sg_chaining && (i < (task_count - 1))) { + task_sg_nents_padded = (task->task_sg_nents + 1); task->task_padded_sg = 1; - } + } else + task_sg_nents_padded = task->task_sg_nents; task->task_sg = kmalloc(sizeof(struct scatterlist) * - task->task_sg_nents, GFP_KERNEL); + task_sg_nents_padded, GFP_KERNEL); if (!task->task_sg) { cmd->se_dev->transport->free_task(task); return -ENOMEM; } - sg_init_table(task->task_sg, task->task_sg_nents); + sg_init_table(task->task_sg, task_sg_nents_padded); task_size = task->task_size; |