Commit daf2206e authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Changpeng Liu
Browse files

iscsi: Skip metadata space in read or write data from network socket 



This patch leaves metadata space in data buffer for read or write I/O
to generate and verify DIF.

For write I/O,
- in spdk_iscsi_read_pdu(), leave metadata space for every block
  by calling spdk_dif_set_md_interleave_iovs() and then
  spdk_iscsi_conn_readv_data(), and remember this in PDU.
- in spdk_iscsi_op_scsi() and spdk_iscsi_op_data(), set not data
  length but buffer length to length of an iovec. The reason is
  that the actual data length sent to SCSI layer will be larger
  than the data length set in PDU. SCSI task holds data length
  as an independent member and this change doesn't loose any
  information.

For read I/O, in spdk_iscsi_build_iovs(), leave metadata space for
every block by calling spdk_dif_set_md_interleave_iovs().

The reason why DIF context is saved in PDU is that DIF verification
will be done in spdk_iscsi_conn_write_pdu() and DIF context will be
used there first.

Change-Id: Iac5739211f26a91b00a4ecf2f306bbecec3d78dd
Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/446382


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent c24f5069

lib/iscsi/conn.c

+5 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#include "spdk/endian.h"

#include "spdk/env.h"

#include "spdk/event.h"

#include "spdk/likely.h"

#include "spdk/thread.h"

#include "spdk/queue.h"

#include "spdk/trace.h"
@@ -1301,6 +1302,10 @@ spdk_iscsi_conn_write_pdu(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *p 
{

	uint32_t crc32c;



	if (spdk_unlikely(spdk_iscsi_get_dif_ctx(conn, pdu, &pdu->dif_ctx))) {

		pdu->dif_insert_or_strip = true;

	}



	if (pdu->bhs.opcode != ISCSI_OP_LOGIN_RSP) {

		/* Header Digest */

		if (conn->header_digest) {

lib/iscsi/iscsi.c

+88 −8
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include "spdk/crc32.h"

#include "spdk/endian.h"

#include "spdk/env.h"

#include "spdk/likely.h"

#include "spdk/trace.h"

#include "spdk/string.h"

#include "spdk/queue.h"
@@ -384,6 +385,34 @@ spdk_iscsi_check_data_segment_length(struct spdk_iscsi_conn *conn, 
	}

}



static int

spdk_iscsi_conn_read_data_segment(struct spdk_iscsi_conn *conn,

				  struct spdk_iscsi_pdu *pdu,

				  uint32_t segment_len)

{

	struct spdk_dif_ctx dif_ctx;

	struct iovec iovs[32];

	int rc;



	if (spdk_likely(!spdk_iscsi_get_dif_ctx(conn, pdu, &dif_ctx))) {

		return spdk_iscsi_conn_read_data(conn,

						 segment_len - pdu->data_valid_bytes,

						 pdu->data_buf + pdu->data_valid_bytes);

	} else {

		pdu->dif_insert_or_strip = true;

		rc = spdk_dif_set_md_interleave_iovs(iovs, 32,

						     pdu->data_buf, pdu->data_buf_len,

						     pdu->data_valid_bytes, segment_len, NULL,

						     &dif_ctx);

		if (rc > 0) {

			return spdk_iscsi_conn_readv_data(conn, iovs, rc);

		} else {

			SPDK_ERRLOG("Setup iovs for interleaved metadata failed\n");

			return rc;

		}

	}

}



int

spdk_iscsi_read_pdu(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu **_pdu)

{
@@ -488,9 +517,7 @@ spdk_iscsi_read_pdu(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu **_pdu) 
			pdu->data_buf = pdu->mobj->buf;

		}



		rc = spdk_iscsi_conn_read_data(conn,

					       data_len - pdu->data_valid_bytes,

					       pdu->data_buf + pdu->data_valid_bytes);

		rc = spdk_iscsi_conn_read_data_segment(conn, pdu, data_len);

		if (rc < 0) {

			*_pdu = NULL;

			spdk_put_pdu(pdu);
@@ -615,6 +642,41 @@ _iov_ctx_set_iov(struct _iov_ctx *ctx, uint8_t *data, uint32_t data_len) 
	return true;

}



/* Build iovec array to leave metadata space for every data block

 * when reading data segment from socket.

 */

static inline bool

_iov_ctx_set_md_interleave_iov(struct _iov_ctx *ctx,

			       void *buf, uint32_t buf_len, uint32_t data_len,

			       struct spdk_dif_ctx *dif_ctx)

{

	int rc;

	uint32_t mapped_len = 0;



	if (ctx->iov_offset >= data_len) {

		ctx->iov_offset -= buf_len;

	} else {

		rc = spdk_dif_set_md_interleave_iovs(ctx->iov, ctx->num_iovs - ctx->iovcnt,

						     buf, buf_len,

						     ctx->iov_offset, data_len, &mapped_len,

						     dif_ctx);

		if (rc < 0) {

			SPDK_ERRLOG("Failed to setup iovs for DIF strip\n");

			return false;

		}



		ctx->mapped_len += mapped_len;

		ctx->iov_offset = 0;

		ctx->iovcnt += rc;



		if (ctx->iovcnt == ctx->num_iovs) {

			return false;

		}

	}



	return true;

}



int

spdk_iscsi_build_iovs(struct spdk_iscsi_conn *conn, struct iovec *iovs, int num_iovs,

		      struct spdk_iscsi_pdu *pdu, uint32_t *_mapped_length)
@@ -660,9 +722,16 @@ spdk_iscsi_build_iovs(struct spdk_iscsi_conn *conn, struct iovec *iovs, int num_ 


	/* Data Segment */

	if (data_len > 0) {

		if (!pdu->dif_insert_or_strip) {

			if (!_iov_ctx_set_iov(&ctx, pdu->data, data_len)) {

				goto end;

			}

		} else {

			if (!_iov_ctx_set_md_interleave_iov(&ctx, pdu->data, pdu->data_buf_len,

							    data_len, &pdu->dif_ctx)) {

				goto end;

			}

		}

	}



	/* Data Digest */
@@ -2911,6 +2980,7 @@ spdk_iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
	uint64_t lun;

	uint32_t task_tag;

	uint32_t transfer_len;

	uint32_t scsi_data_len;

	int F_bit, R_bit, W_bit;

	int lun_i, rc;

	struct iscsi_bhs_scsi_req *reqh;
@@ -2991,6 +3061,12 @@ spdk_iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
			return spdk_iscsi_reject(conn, pdu, ISCSI_REASON_PROTOCOL_ERROR);

		}



		if (spdk_likely(!pdu->dif_insert_or_strip)) {

			scsi_data_len = pdu->data_segment_len;

		} else {

			scsi_data_len = pdu->data_buf_len;

		}



		if (F_bit && pdu->data_segment_len < transfer_len) {

			/* needs R2T */

			rc = spdk_add_transfer_task(conn, task);
@@ -3006,14 +3082,14 @@ spdk_iscsi_op_scsi(struct spdk_iscsi_conn *conn, struct spdk_iscsi_pdu *pdu) 
			} else {

				/* we are doing the first partial write task */

				task->scsi.ref++;

				spdk_scsi_task_set_data(&task->scsi, pdu->data, pdu->data_segment_len);

				spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);

				task->scsi.length = pdu->data_segment_len;

			}

		}



		if (pdu->data_segment_len == transfer_len) {

			/* we are doing small writes with no R2T */

			spdk_scsi_task_set_data(&task->scsi, pdu->data, transfer_len);

			spdk_scsi_task_set_data(&task->scsi, pdu->data, scsi_data_len);

			task->scsi.length = transfer_len;

		}

	} else {
@@ -4258,7 +4334,11 @@ static int spdk_iscsi_op_data(struct spdk_iscsi_conn *conn, 
	}

	subtask->scsi.offset = buffer_offset;

	subtask->scsi.length = pdu->data_segment_len;

	if (spdk_likely(!pdu->dif_insert_or_strip)) {

		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_segment_len);

	} else {

		spdk_scsi_task_set_data(&subtask->scsi, pdu->data, pdu->data_buf_len);

	}

	spdk_iscsi_task_associate_pdu(subtask, pdu);



	if (task->next_expected_r2t_offset == transfer_len) {

lib/iscsi/iscsi.h

+3 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#include "iscsi/tgt_node.h"



#include "spdk/assert.h"

#include "spdk/dif.h"

#include "spdk/util.h"



#define SPDK_ISCSI_DEFAULT_NODEBASE "iqn.2016-06.io.spdk"
@@ -173,6 +174,8 @@ struct spdk_iscsi_pdu { 
	uint32_t cmd_sn;

	uint32_t writev_offset;

	uint32_t data_buf_len;

	bool dif_insert_or_strip;

	struct spdk_dif_ctx dif_ctx;

	TAILQ_ENTRY(spdk_iscsi_pdu)	tailq;