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, 16 deletions

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 518fd4e86409..f86833fcf33c 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1542,21 +1542,6 @@ static int lio_queue_status(struct se_cmd *se_cmd)
         return 0;
 }
 
-static u16 lio_set_fabric_sense_len(struct se_cmd *se_cmd, u32 sense_length)
-{
-        unsigned char *buffer = se_cmd->sense_buffer;
-        /*
-         * From RFC-3720 10.4.7.  Data Segment - Sense and Response Data Segment
-         * 16-bit SenseLength.
-         */
-        buffer[0] = ((sense_length >> 8) & 0xff);
-        buffer[1] = (sense_length & 0xff);
-        /*
-         * Return two byte offset into allocated sense_buffer.
-         */
-        return 2;
-}
-
 static int lio_queue_tm_rsp(struct se_cmd *se_cmd)
 {
         struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
@@ -1740,7 +1725,6 @@ int iscsi_target_register_configfs(void)
         fabric->tf_ops.queue_data_in = &lio_queue_data_in;
         fabric->tf_ops.queue_status = &lio_queue_status;
         fabric->tf_ops.queue_tm_rsp = &lio_queue_tm_rsp;
-        fabric->tf_ops.set_fabric_sense_len = &lio_set_fabric_sense_len;
         /*
          * Setup function pointers for generic logic in target_core_fabric_configfs.c
          */