target: Add protection SGLs to target_submit_cmd_map_sgls

This patch adds support to target_submit_cmd_map_sgls() for
accepting 'sgl_prot' + 'sgl_prot_count' parameters for
DIF protection information.

Note the passed parameters are stored at se_cmd->t_prot_sg
and se_cmd->t_prot_nents respectively.

Also, update tcm_loop and vhost-scsi fabrics usage of
target_submit_cmd_map_sgls() to take into account the
new parameters.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 15 insertions, 3 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 763ee450f71b..112b795a7b80 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -217,7 +217,7 @@ static void tcm_loop_submission_work(struct work_struct *work)
                         scsi_bufflen(sc), tcm_loop_sam_attr(sc),
                         sc->sc_data_direction, 0,
                         scsi_sglist(sc), scsi_sg_count(sc),
-                        sgl_bidi, sgl_bidi_count);
+                        sgl_bidi, sgl_bidi_count, NULL, 0);
         if (rc < 0) {
                 set_host_byte(sc, DID_NO_CONNECT);
                 goto out_done;
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index fa4fc0429452..aebe0bb3f23b 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1310,6 +1310,8 @@ transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
  * @sgl_count: scatterlist count for unidirectional mapping
  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
+ * @sgl_prot: struct scatterlist memory protection information
+ * @sgl_prot_count: scatterlist count for protection information
  *
  * Returns non zero to signal active I/O shutdown failure.  All other
  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
@@ -1322,7 +1324,8 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess
                 unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
                 u32 data_length, int task_attr, int data_dir, int flags,
                 struct scatterlist *sgl, u32 sgl_count,
-                struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
+                struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
+                struct scatterlist *sgl_prot, u32 sgl_prot_count)
 {
         struct se_portal_group *se_tpg;
         sense_reason_t rc;
@@ -1364,6 +1367,14 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess
                 target_put_sess_cmd(se_sess, se_cmd);
                 return 0;
         }
+        /*
+         * Save pointers for SGLs containing protection information,
+         * if present.
+         */
+        if (sgl_prot_count) {
+                se_cmd->t_prot_sg = sgl_prot;
+                se_cmd->t_prot_nents = sgl_prot_count;
+        }
 
         rc = target_setup_cmd_from_cdb(se_cmd, cdb);
         if (rc != 0) {
@@ -1406,6 +1417,7 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess
                         return 0;
                 }
         }
+
         /*
          * Check if we need to delay processing because of ALUA
          * Active/NonOptimized primary access state..
@@ -1445,7 +1457,7 @@ int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
 {
         return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
                         unpacked_lun, data_length, task_attr, data_dir,
-                        flags, NULL, 0, NULL, 0);
+                        flags, NULL, 0, NULL, 0, NULL, 0);
 }
 EXPORT_SYMBOL(target_submit_cmd);