target: add unknown size flag to target_submit_cmd()

The UASP protocol does not inform the target device upfront how much
data it should expect so we have to learn in from the CDB.  So in order
to handle this case, add a TARGET_SCF_UNKNOWN_SIZE to target_submit_cmd()
and perform an explictly assignment for se_cmd->data_length from the
extracted CDB size in transport_generic_cmd_sequencer().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 443704f84fd5..25c67c800f3d 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1701,6 +1701,8 @@ void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
          */
         transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
                                 data_length, data_dir, task_attr, sense);
+        if (flags & TARGET_SCF_UNKNOWN_SIZE)
+                se_cmd->unknown_data_length = 1;
         /*
          * Obtain struct se_cmd->cmd_kref reference and add new cmd to
          * se_sess->sess_cmd_list.  A second kref_get here is necessary
@@ -3142,6 +3144,9 @@ static int transport_generic_cmd_sequencer(
                 goto out_unsupported_cdb;
         }
 
+        if (cmd->unknown_data_length)
+                cmd->data_length = size;
+
         if (size != cmd->data_length) {
                 pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
                         " %u does not match SCSI CDB Length: %u for SAM Opcode:"