Commit c265fa18 authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Tomasz Zawadzki
Browse files

lib/iscsi: Separate PDU header and payload handling for SCSI command 



SCSI command uses iSCSI task and data buffer, and will use zero copy
bdev I/O APIs.

To use zero copy bdev I/O APIs, we have to allocate iSCSI task
before allocating data buffer.

Hence we separate PDU header and payload handling for SCSI command,
include iSCSI task allocation into PDU header handling first.

Use pdu->task to pass the task allocated by the former to the latter.

In iscsi_pdu_hdr_op_scsi(), we can not expect pdu->data_segment_len
is set. So getting data segment length from PDU BHS instead.

In the updated iscsi_op_scsi(), if it sees pdu->task is NULL or
pdu->is_rejected is true, do nothing. Besides, check LUN hot plug
again to separate PDU header handling and PDU payload handling.

Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Ic09451ab022b9714381f03c63bd3008c39fedb8e
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/470290


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
parent fcccc160

lib/iscsi/iscsi.c

+43 −8
Original line number Diff line number Diff line
@@ -3279,7 +3279,6 @@ iscsi_op_scsi_read(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task) 
	int32_t remaining_size;



	TAILQ_INIT(&task->subtask_list);

	task->scsi.dxfer_dir = SPDK_SCSI_DIR_FROM_DEV;

	task->parent = NULL;

	task->scsi.offset = 0;

	task->scsi.length = DMIN32(SPDK_BDEV_LARGE_BUF_MAX_SIZE, task->scsi.transfer_len);
@@ -3350,13 +3349,14 @@ iscsi_op_scsi_write(struct spdk_iscsi_conn *conn, struct spdk_iscsi_task *task) 
}



static int

iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)

iscsi_pdu_hdr_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)

{

	struct spdk_iscsi_task	*task;

	struct spdk_scsi_dev	*dev;

	uint8_t *cdb;

	uint64_t lun;

	uint32_t task_tag;

	uint32_t data_len;

	uint32_t transfer_len;

	int R_bit, W_bit;

	int lun_i;
@@ -3373,6 +3373,7 @@ iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
	W_bit = reqh->write_bit;

	lun = from_be64(&reqh->lun);

	task_tag = from_be32(&reqh->itt);

	data_len = ISCSI_ALIGN(DGET24(pdu->bhs.data_segment_len));

	transfer_len = from_be32(&reqh->expected_data_xfer_len);

	cdb = reqh->cdb;
@@ -3412,7 +3413,7 @@ iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 


	/* no bi-directional support */

	if (R_bit) {

		return iscsi_op_scsi_read(conn, task);

		task->scsi.dxfer_dir = SPDK_SCSI_DIR_FROM_DEV;

	} else if (W_bit) {

		task->scsi.dxfer_dir = SPDK_SCSI_DIR_TO_DEV;
@@ -3438,13 +3439,11 @@ iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
		}



		/* check the ImmediateData and also pdu->data_segment_len */

		if ((!conn->sess->ImmediateData && (pdu->data_segment_len > 0)) ||

		    (pdu->data_segment_len > conn->sess->FirstBurstLength)) {

		if ((!conn->sess->ImmediateData && (data_len > 0)) ||

		    (data_len > conn->sess->FirstBurstLength)) {

			spdk_iscsi_task_put(task);

			return iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);

		}



		return iscsi_op_scsi_write(conn, task);

	} else {

		/* neither R nor W bit set */

		task->scsi.dxfer_dir = SPDK_SCSI_DIR_NONE;
@@ -3455,8 +3454,44 @@ iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
		}

	}



	pdu->task = task;

	return 0;

}



static int

iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu)

{

	struct spdk_iscsi_task *task;

	int rc;



	rc = iscsi_pdu_hdr_op_scsi(conn, pdu);

	if (rc != 0 || pdu->is_rejected || pdu->task == NULL) {

		return rc;

	}



	task = pdu->task;



	if (spdk_scsi_dev_get_lun(conn->dev, task->lun_id) == NULL) {

		spdk_scsi_task_process_null_lun(&task->scsi);

		spdk_iscsi_task_cpl(&task->scsi);

		return 0;

	}



	switch (task->scsi.dxfer_dir) {

	case SPDK_SCSI_DIR_FROM_DEV:

		return iscsi_op_scsi_read(conn, task);

	case SPDK_SCSI_DIR_TO_DEV:

		return iscsi_op_scsi_write(conn, task);

	case SPDK_SCSI_DIR_NONE:

		iscsi_queue_task(conn, task);

		return 0;

	default:

		assert(false);

		spdk_iscsi_task_put(task);

		break;

	}



	return SPDK_ISCSI_CONNECTION_FATAL;

}



static void