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Commit c07d4444 authored by Boaz Harrosh's avatar Boaz Harrosh Committed by James Bottomley
Browse files

[SCSI] iscsi: bidi support at the generic libiscsi level 



- prepare the additional bidi_read rlength header.
- access the right scsi_in() and/or scsi_out() side of things.
  also for resid.
- Handle BIDI underflow overflow from target

Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
Reviewed-by: default avatarPete Wyckoff <pw@osc.edu>
Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 38d1c069

drivers/scsi/libiscsi.c

+70 −15
Original line number Diff line number Diff line
@@ -176,6 +176,31 @@ static int iscsi_prep_ecdb_ahs(struct iscsi_cmd_task *ctask) 
	return 0;

}



static int iscsi_prep_bidi_ahs(struct iscsi_cmd_task *ctask)

{

	struct scsi_cmnd *sc = ctask->sc;

	struct iscsi_rlength_ahdr *rlen_ahdr;

	int rc;



	rlen_ahdr = iscsi_next_hdr(ctask);

	rc = iscsi_add_hdr(ctask, sizeof(*rlen_ahdr));

	if (rc)

		return rc;



	rlen_ahdr->ahslength =

		cpu_to_be16(sizeof(rlen_ahdr->read_length) +

						  sizeof(rlen_ahdr->reserved));

	rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;

	rlen_ahdr->reserved = 0;

	rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);



	debug_scsi("bidi-in rlen_ahdr->read_length(%d) "

		   "rlen_ahdr->ahslength(%d)\n",

		   be32_to_cpu(rlen_ahdr->read_length),

		   be16_to_cpu(rlen_ahdr->ahslength));

	return 0;

}



/**

 * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu

 * @ctask: iscsi cmd task
@@ -200,7 +225,6 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) 
	hdr->flags = ISCSI_ATTR_SIMPLE;

	int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);

	hdr->itt = build_itt(ctask->itt, session->age);

	hdr->data_length = cpu_to_be32(scsi_bufflen(sc));

	hdr->cmdsn = cpu_to_be32(session->cmdsn);

	session->cmdsn++;

	hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
@@ -216,7 +240,15 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) 
	memcpy(hdr->cdb, sc->cmnd, cmd_len);



	ctask->imm_count = 0;

	if (scsi_bidi_cmnd(sc)) {

		hdr->flags |= ISCSI_FLAG_CMD_READ;

		rc = iscsi_prep_bidi_ahs(ctask);

		if (rc)

			return rc;

	}

	if (sc->sc_data_direction == DMA_TO_DEVICE) {

		unsigned out_len = scsi_out(sc)->length;

		hdr->data_length = cpu_to_be32(out_len);

		hdr->flags |= ISCSI_FLAG_CMD_WRITE;

		/*

		 * Write counters:
@@ -237,19 +269,19 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) 
		ctask->unsol_datasn = 0;



		if (session->imm_data_en) {

			if (scsi_bufflen(sc) >= session->first_burst)

			if (out_len >= session->first_burst)

				ctask->imm_count = min(session->first_burst,

							conn->max_xmit_dlength);

			else

				ctask->imm_count = min(scsi_bufflen(sc),

				ctask->imm_count = min(out_len,

							conn->max_xmit_dlength);

			hton24(hdr->dlength, ctask->imm_count);

		} else

			zero_data(hdr->dlength);



		if (!session->initial_r2t_en) {

			ctask->unsol_count = min((session->first_burst),

				(scsi_bufflen(sc))) - ctask->imm_count;

			ctask->unsol_count = min(session->first_burst, out_len)

							     - ctask->imm_count;

			ctask->unsol_offset = ctask->imm_count;

		}
@@ -259,6 +291,7 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) 
	} else {

		hdr->flags |= ISCSI_FLAG_CMD_FINAL;

		zero_data(hdr->dlength);

		hdr->data_length = cpu_to_be32(scsi_in(sc)->length);



		if (sc->sc_data_direction == DMA_FROM_DEVICE)

			hdr->flags |= ISCSI_FLAG_CMD_READ;
@@ -277,10 +310,12 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask) 
		return EIO;



	conn->scsicmd_pdus_cnt++;

	debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "

		"cmdsn %d win %d]\n",

	debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x "

		"len %d bidi_len %d cmdsn %d win %d]\n",

		scsi_bidi_cmnd(sc) ? "bidirectional" :

		     sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",

		conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),

		conn->id, sc, sc->cmnd[0], ctask->itt,

		scsi_bufflen(sc), scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,

		session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);

	return 0;

}
@@ -343,7 +378,12 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask, 
		conn->session->tt->cleanup_cmd_task(conn, ctask);



	sc->result = err;

	if (!scsi_bidi_cmnd(sc))

		scsi_set_resid(sc, scsi_bufflen(sc));

	else {

		scsi_out(sc)->resid = scsi_out(sc)->length;

		scsi_in(sc)->resid = scsi_in(sc)->length;

	}

	if (conn->ctask == ctask)

		conn->ctask = NULL;

	/* release ref from queuecommand */
@@ -478,6 +518,18 @@ static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
			   min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));

	}



	if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |

			   ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {

		int res_count = be32_to_cpu(rhdr->bi_residual_count);



		if (scsi_bidi_cmnd(sc) && res_count > 0 &&

				(rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||

				 res_count <= scsi_in(sc)->length))

			scsi_in(sc)->resid = res_count;

		else

			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;

	}



	if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |

	                   ISCSI_FLAG_CMD_OVERFLOW)) {

		int res_count = be32_to_cpu(rhdr->residual_count);
@@ -485,13 +537,11 @@ static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr, 
		if (res_count > 0 &&

		    (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||

		     res_count <= scsi_bufflen(sc)))

			/* write side for bidi or uni-io set_resid */

			scsi_set_resid(sc, res_count);

		else

			sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;

	} else if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |

	                          ISCSI_FLAG_CMD_BIDI_OVERFLOW))

		sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;



	}

out:

	debug_scsi("done [sc %lx res %d itt 0x%x]\n",

		   (long)sc, sc->result, ctask->itt);
@@ -1147,7 +1197,12 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *)) 
fault:

	spin_unlock(&session->lock);

	debug_scsi("iscsi: cmd 0x%x is not queued (%d)\n", sc->cmnd[0], reason);

	if (!scsi_bidi_cmnd(sc))

		scsi_set_resid(sc, scsi_bufflen(sc));

	else {

		scsi_out(sc)->resid = scsi_out(sc)->length;

		scsi_in(sc)->resid = scsi_in(sc)->length;

	}

	sc->scsi_done(sc);

	spin_lock(host->host_lock);

	return 0;