[SCSI] iscsi: fix writepsace race

We can race and misset the suspend bit if iscsi_write_space is
called then iscsi_send returns with a failure indicating
there is no space.

To handle this this patch returns a error upwards allowing xmitworker
to decide if we need to try and transmit again. For the no
write space case xmitworker will not retry, and instead
let iscsi_write_space queue it back up if needed (this relies
on the work queue code to properly requeue us if needed).

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index 92129b97d31e..b684426a5900 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -57,8 +57,12 @@ struct iscsi_mgmt_task;
  *                      Called from queuecommand with session lock held.
  * @init_mgmt_task:     Initialize a iscsi_mgmt_task and any internal structs.
  *                      Called from iscsi_conn_send_generic with xmitmutex.
- * @xmit_cmd_task:      requests LLD to transfer cmd task
- * @xmit_mgmt_task:     requests LLD to transfer mgmt task
+ * @xmit_cmd_task:      Requests LLD to transfer cmd task. Returns 0 or the
+ *                      the number of bytes transferred on success, and -Exyz
+ *                      value on error.
+ * @xmit_mgmt_task:     Requests LLD to transfer mgmt task. Returns 0 or the
+ *                      the number of bytes transferred on success, and -Exyz
+ *                      value on error.
  * @cleanup_cmd_task:   requests LLD to fail cmd task. Called with xmitmutex
  *                      and session->lock after the connection has been
  *                      suspended and terminated during recovery. If called