drivers/scsi/libiscsi.c

Source file repositories/reference/linux-study-clean/drivers/scsi/libiscsi.c

File Facts

System
Linux kernel
Corpus path
drivers/scsi/libiscsi.c
Extension
.c
Size
107614 bytes
Lines
3938
Domain
Driver Families
Bucket
drivers/scsi
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
			iscsi_session_printk(KERN_INFO, session,
					     "task [op %x itt 0x%x/0x%x] rejected.\n",
					     opcode, task->itt, task->hdr_itt);
			return -EACCES;
		}
		/*
		 * And also all data-out PDUs in response to R2T
		 * if fast_abort is set.
		 */
		if (session->fast_abort) {
			iscsi_session_printk(KERN_INFO, session,
					     "task [op %x itt 0x%x/0x%x] fast abort.\n",
					     opcode, task->itt, task->hdr_itt);
			return -EACCES;
		}
		break;
	case ISCSI_TM_FUNC_ABORT_TASK:
		/*
		 * the caller has already checked if the task
		 * they want to abort was in the pending queue so if
		 * we are here the cmd pdu has gone out already, and
		 * we will only hit this for data-outs
		 */
		if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
		    task->hdr_itt == tmf->rtt) {
			ISCSI_DBG_SESSION(session,
					  "Preventing task %x/%x from sending "
					  "data-out due to abort task in "
					  "progress\n", task->itt,
					  task->hdr_itt);
			return -EACCES;
		}
		break;
	}

	return 0;
}

/**
 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
 * @task: iscsi task
 *
 * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
 * fields like dlength or final based on how much data it sends
 */
static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
{
	struct iscsi_conn *conn = task->conn;
	struct iscsi_session *session = conn->session;
	struct scsi_cmnd *sc = task->sc;
	struct iscsi_scsi_req *hdr;
	unsigned hdrlength, cmd_len, transfer_length;
	itt_t itt;
	int rc;

	rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
	if (rc)
		return rc;

	if (conn->session->tt->alloc_pdu) {
		rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
		if (rc)
			return rc;
	}
	hdr = (struct iscsi_scsi_req *)task->hdr;
	itt = hdr->itt;
	memset(hdr, 0, sizeof(*hdr));

	if (session->tt->parse_pdu_itt)
		hdr->itt = task->hdr_itt = itt;
	else
		hdr->itt = task->hdr_itt = build_itt(task->itt,
						     task->conn->session->age);
	task->hdr_len = 0;
	rc = iscsi_add_hdr(task, sizeof(*hdr));
	if (rc)
		return rc;
	hdr->opcode = ISCSI_OP_SCSI_CMD;
	hdr->flags = ISCSI_ATTR_SIMPLE;
	int_to_scsilun(sc->device->lun, &hdr->lun);
	task->lun = hdr->lun;
	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
	cmd_len = sc->cmd_len;
	if (cmd_len < ISCSI_CDB_SIZE)
		memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
	else if (cmd_len > ISCSI_CDB_SIZE) {
		rc = iscsi_prep_ecdb_ahs(task);
		if (rc)
			return rc;

Annotation

Implementation Notes