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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>
This commit is contained in:
Nicholas Bellinger 2012-10-01 23:29:49 -07:00
parent a026757ff5
commit 8f9f44f895
1 changed files with 8 additions and 54 deletions
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62
drivers/target/loopback/tcm_loop.c
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@ -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: