From: Alexander Nezhinsky <nezhinsky@xxxxxxxxx>
Differentiating between various possible cases for tx pdus
(r2t, data-in and scsi_response) has been made using a set of
predicates, some of which are relevant only for a specific
cmd direction types.
Although possibly correct when all counters and flags used
are up-to-date, this may be dangerous and hard to debug.
Explicit check of cmd type allows discriminating only between
the choices feasible for each cmd type.
---
usr/iscsi/iscsid.c | 33 ++++++++++++++++++++++++++++-----
1 files changed, 28 insertions(+), 5 deletions(-)
diff --git a/usr/iscsi/iscsid.c b/usr/iscsi/iscsid.c
index e1180fb..260989f 100644
--- a/usr/iscsi/iscsid.c
+++ b/usr/iscsi/iscsid.c
@@ -1785,14 +1785,37 @@ static int iscsi_task_rx_start(struct iscsi_connection *conn)
static int iscsi_scsi_cmd_tx_start(struct iscsi_task *task)
{
+ enum data_direction data_dir = scsi_get_data_dir(&task->scmd);
int err = 0;
- if (task->r2t_count)
- err = iscsi_r2t_build(task);
- else if (task->offset < scsi_get_in_transfer_len(&task->scmd))
- err = iscsi_data_rsp_build(task);
- else
+ switch (data_dir) {
+ case DATA_NONE:
err = iscsi_cmd_rsp_build(task);
+ break;
+ case DATA_READ:
+ if (task->offset < scsi_get_in_transfer_len(&task->scmd))
+ err = iscsi_data_rsp_build(task);
+ else
+ err = iscsi_cmd_rsp_build(task);
+ break;
+ case DATA_WRITE:
+ if (task->r2t_count)
+ err = iscsi_r2t_build(task);
+ else
+ err = iscsi_cmd_rsp_build(task);
+ break;
+ case DATA_BIDIRECTIONAL:
+ if (task->r2t_count)
+ err = iscsi_r2t_build(task);
+ else if (task->offset < scsi_get_in_transfer_len(&task->scmd))
+ err = iscsi_data_rsp_build(task);
+ else
+ err = iscsi_cmd_rsp_build(task);
+ break;
+ default:
+ eprintf("Unexpected data_dir %d task %p\n", data_dir, task);
+ exit(-1);
+ }
return err;
}
--
1.7.1
--
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