target: Simplify fabric sense data length handling

Every fabric driver has to supply a se_tfo->set_fabric_sense_len()
method, just so iSCSI can return an offset of 2.  However, every fabric
driver is already allocating a sense buffer and passing it into the
target core, either via transport_init_se_cmd() or target_submit_cmd().

So instead of having iSCSI pass the start of its sense buffer into the
core and then later tell the core to skip the first 2 bytes, it seems
easier for iSCSI just to do the offset of 2 when it passes the sense
buffer into the core.  Then we can drop the se_tfo->set_fabric_sense_len()
everywhere, and just add a couple of lines of code to iSCSI to set the
sense data length to the beginning of the buffer right before it sends
it over the network.

(nab: Remove .set_fabric_sense_len usage from tcm_qla2xxx_npiv_ops +
      change transport_get_sense_buffer to follow v3.6-rc6 code w/o
      ->set_fabric_sense_len usage)

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 0 insertions, 6 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 4ab1d0b..7a0da1a 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -846,11 +846,6 @@ static int tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd)
 	return 0;
 }
 
-static u16 tcm_loop_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
-{
-	return 0;
-}
-
 static char *tcm_loop_dump_proto_id(struct tcm_loop_hba *tl_hba)
 {
 	switch (tl_hba->tl_proto_id) {
@@ -1368,7 +1363,6 @@ static int tcm_loop_register_configfs(void)
 	fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
 	fabric->tf_ops.queue_status = &tcm_loop_queue_status;
 	fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
-	fabric->tf_ops.set_fabric_sense_len = &tcm_loop_set_fabric_sense_len;
 
 	/*
 	 * Setup function pointers for generic logic in target_core_fabric_configfs.c