tcm_loop: Convert I/O path to use target_submit_cmd_map_sgls

This patch converts tcm_loop to use target_submit_cmd_map_sgls() for
I/O submission and mapping of pre-allocated SGL memory from incoming
scsi_cmnd -> se_cmd descriptors.

This includes removing the original open-coded fabric uses of target
core callers to support transport_generic_map_mem_to_cmd() between
target_setup_cmd_from_cdb() and transport_handle_cdb_direct() logic.

(v2: Use renamed target_submit_cmd_map_sgls)

Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 7a0da1ae0040895d95cced339dae7b41cae79940..2d444b1ccd33231a57a6bd8f8eb57456ed8f61da 100644 (file)
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -166,7 +166,7 @@ static void tcm_loop_submission_work(struct work_struct *work)
        struct tcm_loop_tpg *tl_tpg;
        struct scatterlist *sgl_bidi = NULL;
        u32 sgl_bidi_count = 0;
-       int ret;
+       int rc;
 
        tl_hba = *(struct tcm_loop_hba **)shost_priv(sc->device->host);
        tl_tpg = &tl_hba->tl_hba_tpgs[sc->device->id];
@@ -187,12 +187,6 @@ static void tcm_loop_submission_work(struct work_struct *work)
                set_host_byte(sc, DID_ERROR);
                goto out_done;
        }
-
-       transport_init_se_cmd(se_cmd, tl_tpg->tl_se_tpg.se_tpg_tfo,
-                       tl_nexus->se_sess,
-                       scsi_bufflen(sc), sc->sc_data_direction,
-                       tcm_loop_sam_attr(sc), &tl_cmd->tl_sense_buf[0]);
-
        if (scsi_bidi_cmnd(sc)) {
                struct scsi_data_buffer *sdb = scsi_in(sc);
 
@@ -201,56 +195,16 @@ static void tcm_loop_submission_work(struct work_struct *work)
                se_cmd->se_cmd_flags |= SCF_BIDI;
 
        }
-
-       if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
-               kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
+       rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
+                       &tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
+                       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);
+       if (rc < 0) {
                set_host_byte(sc, DID_NO_CONNECT);
                goto out_done;
        }
-
-       /*
-        * Because some userspace code via scsi-generic do not memset their
-        * associated read buffers, go ahead and do that here for type
-        * non-data CDBs.  Also note that this is currently guaranteed to be a
-        * single SGL for this case by target core in
-        * target_setup_cmd_from_cdb() -> transport_generic_cmd_sequencer().
-        */
-       if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
-           se_cmd->data_direction == DMA_FROM_DEVICE) {
-               struct scatterlist *sg = scsi_sglist(sc);
-               unsigned char *buf = kmap(sg_page(sg)) + sg->offset;
-
-               if (buf != NULL) {
-                       memset(buf, 0, sg->length);
-                       kunmap(sg_page(sg));
-               }
-       }
-
-       ret = target_setup_cmd_from_cdb(se_cmd, sc->cmnd);
-       if (ret == -ENOMEM) {
-               transport_send_check_condition_and_sense(se_cmd,
-                               TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
-               transport_generic_free_cmd(se_cmd, 0);
-               return;
-       } else if (ret < 0) {
-               if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
-                       tcm_loop_queue_status(se_cmd);
-               else
-                       transport_send_check_condition_and_sense(se_cmd,
-                                       se_cmd->scsi_sense_reason, 0);
-               transport_generic_free_cmd(se_cmd, 0);
-               return;
-       }
-
-       ret = transport_generic_map_mem_to_cmd(se_cmd, scsi_sglist(sc),
-                       scsi_sg_count(sc), sgl_bidi, sgl_bidi_count);
-       if (ret) {
-               transport_send_check_condition_and_sense(se_cmd,
-                                       se_cmd->scsi_sense_reason, 0);
-               transport_generic_free_cmd(se_cmd, 0);
-               return;
-       }
-       transport_handle_cdb_direct(se_cmd);
        return;
 
 out_done: