3 files changed, 150 insertions, 116 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 1e722f5..0afdca2 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -109,7 +109,7 @@ iscsi_hdr_digest(struct iscsi_conn *conn, struct iscsi_buf *buf,
 	struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
 
 	crypto_hash_digest(&tcp_conn->tx_hash, &buf->sg, buf->sg.length, crc);
-	buf->sg.length = tcp_conn->hdr_size;
+	buf->sg.length += sizeof(u32);
 }
 
 static inline int
@@ -423,7 +423,7 @@ iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 
 	tcp_ctask->exp_datasn = r2tsn + 1;
 	__kfifo_put(tcp_ctask->r2tqueue, (void*)&r2t, sizeof(void*));
-	tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+	tcp_ctask->xmstate |= XMSTATE_SOL_HDR_INIT;
 	list_move_tail(&ctask->running, &conn->xmitqueue);
 
 	scsi_queue_work(session->host, &conn->xmitwork);
@@ -1284,41 +1284,10 @@ static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
 static void
 iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
 {
-	struct scsi_cmnd *sc = ctask->sc;
 	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
 
 	BUG_ON(__kfifo_len(tcp_ctask->r2tqueue));
-
-	tcp_ctask->sent = 0;
-	tcp_ctask->sg_count = 0;
-	tcp_ctask->exp_datasn = 0;
-
-	if (sc->sc_data_direction == DMA_TO_DEVICE) {
-		tcp_ctask->xmstate = XMSTATE_W_HDR;
-		BUG_ON(sc->request_bufflen == 0);
-
-		if (sc->use_sg) {
-			struct scatterlist *sg = sc->request_buffer;
-
-			iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
-			tcp_ctask->sg = sg + 1;
-			tcp_ctask->bad_sg = sg + sc->use_sg;
-		} else {
-			iscsi_buf_init_iov(&tcp_ctask->sendbuf,
-					   sc->request_buffer,
-					   sc->request_bufflen);
-			tcp_ctask->sg = NULL;
-			tcp_ctask->bad_sg = NULL;
-		}
-		debug_scsi("cmd [itt 0x%x total %d imm_data %d "
-			   "unsol count %d, unsol offset %d]\n",
-			   ctask->itt, sc->request_bufflen, ctask->imm_count,
-			   ctask->unsol_count, ctask->unsol_offset);
-	} else
-		tcp_ctask->xmstate = XMSTATE_R_HDR;
-
-	iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
-			    sizeof(struct iscsi_hdr));
+	tcp_ctask->xmstate = XMSTATE_CMD_HDR_INIT;
 }
 
 /**
@@ -1331,9 +1300,11 @@ iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
  *	call it again later, or recover. '0' return code means successful
  *	xmit.
  *
- *	Management xmit state machine consists of two states:
- *		IN_PROGRESS_IMM_HEAD - PDU Header xmit in progress
- *		IN_PROGRESS_IMM_DATA - PDU Data xmit in progress
+ *	Management xmit state machine consists of these states:
+ *		XMSTATE_IMM_HDR_INIT	- calculate digest of PDU Header
+ *		XMSTATE_IMM_HDR 	- PDU Header xmit in progress
+ *		XMSTATE_IMM_DATA 	- PDU Data xmit in progress
+ *		XMSTATE_IDLE		- management PDU is done
  **/
 static int
 iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
@@ -1344,23 +1315,34 @@ iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
 	debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
 		conn->id, tcp_mtask->xmstate, mtask->itt);
 
-	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
-		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
-		if (mtask->data_count)
+	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR_INIT) {
+		iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
+				   sizeof(struct iscsi_hdr));
+
+		if (mtask->data_count) {
 			tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
+			iscsi_buf_init_iov(&tcp_mtask->sendbuf,
+					   (char*)mtask->data,
+					   mtask->data_count);
+		}
+
 		if (conn->c_stage != ISCSI_CONN_INITIAL_STAGE &&
 		    conn->stop_stage != STOP_CONN_RECOVER &&
 		    conn->hdrdgst_en)
 			iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
 					(u8*)tcp_mtask->hdrext);
+
+		tcp_mtask->sent = 0;
+		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR_INIT;
+		tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
+	}
+
+	if (tcp_mtask->xmstate & XMSTATE_IMM_HDR) {
 		rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
 				   mtask->data_count);
-		if (rc) {
-			tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
-			if (mtask->data_count)
-				tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
+		if (rc)
 			return rc;
-		}
+		tcp_mtask->xmstate &= ~XMSTATE_IMM_HDR;
 	}
 
 	if (tcp_mtask->xmstate & XMSTATE_IMM_DATA) {
@@ -1394,55 +1376,75 @@ iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
 	return 0;
 }
 
-static inline int
-iscsi_send_read_hdr(struct iscsi_conn *conn,
-		    struct iscsi_tcp_cmd_task *tcp_ctask)
+static int
+iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 {
-	int rc;
+	struct scsi_cmnd *sc = ctask->sc;
+	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
+	int rc = 0;
 
-	tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
-	if (conn->hdrdgst_en)
-		iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
-				 (u8*)tcp_ctask->hdrext);
-	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
-	if (!rc) {
-		BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
-		return 0; /* wait for Data-In */
-	}
-	tcp_ctask->xmstate |= XMSTATE_R_HDR;
-	return rc;
-}
+	if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_INIT) {
+		tcp_ctask->sent = 0;
+		tcp_ctask->sg_count = 0;
+		tcp_ctask->exp_datasn = 0;
+
+		if (sc->sc_data_direction == DMA_TO_DEVICE) {
+			if (sc->use_sg) {
+				struct scatterlist *sg = sc->request_buffer;
+
+				iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
+				tcp_ctask->sg = sg + 1;
+				tcp_ctask->bad_sg = sg + sc->use_sg;
+			} else {
+				iscsi_buf_init_iov(&tcp_ctask->sendbuf,
+						   sc->request_buffer,
+						   sc->request_bufflen);
+				tcp_ctask->sg = NULL;
+				tcp_ctask->bad_sg = NULL;
+			}
 
-static inline int
-iscsi_send_write_hdr(struct iscsi_conn *conn,
-		     struct iscsi_cmd_task *ctask)
-{
-	struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
-	int rc;
+			debug_scsi("cmd [itt 0x%x total %d imm_data %d "
+				   "unsol count %d, unsol offset %d]\n",
+				   ctask->itt, sc->request_bufflen,
+				   ctask->imm_count, ctask->unsol_count,
+				   ctask->unsol_offset);
+		}
 
-	tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
-	if (conn->hdrdgst_en)
-		iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
-				 (u8*)tcp_ctask->hdrext);
-	rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
-	if (rc) {
-		tcp_ctask->xmstate |= XMSTATE_W_HDR;
-		return rc;
+		iscsi_buf_init_iov(&tcp_ctask->headbuf, (char*)ctask->hdr,
+				  sizeof(struct iscsi_hdr));
+
+		if (conn->hdrdgst_en)
+			iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
+					 (u8*)tcp_ctask->hdrext);
+		tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_INIT;
+		tcp_ctask->xmstate |= XMSTATE_CMD_HDR_XMIT;
 	}
 
-	if (ctask->imm_count) {
-		tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
-		iscsi_set_padding(tcp_ctask, ctask->imm_count);
+	if (tcp_ctask->xmstate & XMSTATE_CMD_HDR_XMIT) {
+		rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
+		if (rc)
+			return rc;
+		tcp_ctask->xmstate &= ~XMSTATE_CMD_HDR_XMIT;
+
+		if (sc->sc_data_direction != DMA_TO_DEVICE)
+			return 0;
+
+		if (ctask->imm_count) {
+			tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
+			iscsi_set_padding(tcp_ctask, ctask->imm_count);
 
-		if (ctask->conn->datadgst_en) {
-			iscsi_data_digest_init(ctask->conn->dd_data, tcp_ctask);
-			tcp_ctask->immdigest = 0;
+			if (ctask->conn->datadgst_en) {
+				iscsi_data_digest_init(ctask->conn->dd_data,
+						       tcp_ctask);
+				tcp_ctask->immdigest = 0;
+			}
 		}
-	}
 
-	if (ctask->unsol_count)
-		tcp_ctask->xmstate |= XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
-	return 0;
+		if (ctask->unsol_count)
+			tcp_ctask->xmstate |=
+					XMSTATE_UNS_HDR | XMSTATE_UNS_INIT;
+	}
+	return rc;
 }
 
 static int
@@ -1631,9 +1633,7 @@ static int iscsi_send_sol_pdu(struct iscsi_conn *conn,
 	struct iscsi_data_task *dtask;
 	int left, rc;
 
-	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
-		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
-		tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
+	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR_INIT) {
 		if (!tcp_ctask->r2t) {
 			spin_lock_bh(&session->lock);
 			__kfifo_get(tcp_ctask->r2tqueue, (void*)&tcp_ctask->r2t,
@@ -1647,12 +1647,19 @@ send_hdr:
 		if (conn->hdrdgst_en)
 			iscsi_hdr_digest(conn, &r2t->headbuf,
 					(u8*)dtask->hdrext);
+		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR_INIT;
+		tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+	}
+
+	if (tcp_ctask->xmstate & XMSTATE_SOL_HDR) {
+		r2t = tcp_ctask->r2t;
+		dtask = &r2t->dtask;
+
 		rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
-		if (rc) {
-			tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
-			tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
+		if (rc)
 			return rc;
-		}
+		tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
+		tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
 
 		if (conn->datadgst_en) {
 			iscsi_data_digest_init(conn->dd_data, tcp_ctask);
@@ -1684,8 +1691,6 @@ send_hdr:
 		left = r2t->data_length - r2t->sent;
 		if (left) {
 			iscsi_solicit_data_cont(conn, ctask, r2t, left);
-			tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
-			tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
 			goto send_hdr;
 		}
 
@@ -1700,8 +1705,6 @@ send_hdr:
 		if (__kfifo_get(tcp_ctask->r2tqueue, (void*)&r2t,
 				sizeof(void*))) {
 			tcp_ctask->r2t = r2t;
-			tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
-			tcp_ctask->xmstate &= ~XMSTATE_SOL_HDR;
 			spin_unlock_bh(&session->lock);
 			goto send_hdr;
 		}
@@ -1710,6 +1713,46 @@ send_hdr:
 	return 0;
 }
 
+/**
+ * iscsi_tcp_ctask_xmit - xmit normal PDU task
+ * @conn: iscsi connection
+ * @ctask: iscsi command task
+ *
+ * Notes:
+ *	The function can return -EAGAIN in which case caller must
+ *	call it again later, or recover. '0' return code means successful
+ *	xmit.
+ *	The function is devided to logical helpers (above) for the different
+ *	xmit stages.
+ *
+ *iscsi_send_cmd_hdr()
+ *	XMSTATE_CMD_HDR_INIT - prepare Header and Data buffers Calculate
+ *	                       Header Digest
+ *	XMSTATE_CMD_HDR_XMIT - Transmit header in progress
+ *
+ *iscsi_send_padding
+ *	XMSTATE_W_PAD        - Prepare and send pading
+ *	XMSTATE_W_RESEND_PAD - retry send pading
+ *
+ *iscsi_send_digest
+ *	XMSTATE_W_RESEND_DATA_DIGEST - Finalize and send Data Digest
+ *	XMSTATE_W_RESEND_DATA_DIGEST - retry sending digest
+ *
+ *iscsi_send_unsol_hdr
+ *	XMSTATE_UNS_INIT     - prepare un-solicit data header and digest
+ *	XMSTATE_UNS_HDR      - send un-solicit header
+ *
+ *iscsi_send_unsol_pdu
+ *	XMSTATE_UNS_DATA     - send un-solicit data in progress
+ *
+ *iscsi_send_sol_pdu
+ *	XMSTATE_SOL_HDR_INIT - solicit data header and digest initialize
+ *	XMSTATE_SOL_HDR      - send solicit header
+ *	XMSTATE_SOL_DATA     - send solicit data
+ *
+ *iscsi_tcp_ctask_xmit
+ *	XMSTATE_IMM_DATA     - xmit managment data (??)
+ **/
 static int
 iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 {
@@ -1725,14 +1768,11 @@ iscsi_tcp_ctask_xmit(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
 	if (ctask->mtask)
 		return rc;
 
-	if (tcp_ctask->xmstate & XMSTATE_R_HDR)
-		return iscsi_send_read_hdr(conn, tcp_ctask);
-
-	if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
-		rc = iscsi_send_write_hdr(conn, ctask);
-		if (rc)
-			return rc;
-	}
+	rc = iscsi_send_cmd_hdr(conn, ctask);
+	if (rc)
+		return rc;
+	if (ctask->sc->sc_data_direction != DMA_TO_DEVICE)
+		return 0;
 
 	if (tcp_ctask->xmstate & XMSTATE_IMM_DATA) {
 		rc = iscsi_send_data(ctask, &tcp_ctask->sendbuf, &tcp_ctask->sg,
@@ -1913,15 +1953,7 @@ iscsi_tcp_mgmt_init(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask,
 		    char *data, uint32_t data_size)
 {
 	struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
-
-	iscsi_buf_init_iov(&tcp_mtask->headbuf, (char*)mtask->hdr,
-			   sizeof(struct iscsi_hdr));
-	tcp_mtask->xmstate = XMSTATE_IMM_HDR;
-	tcp_mtask->sent = 0;
-
-	if (mtask->data_count)
-		iscsi_buf_init_iov(&tcp_mtask->sendbuf, (char*)mtask->data,
-				    mtask->data_count);
+	tcp_mtask->xmstate = XMSTATE_IMM_HDR_INIT;
 }
 
 static int
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index f909edb..b039160 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -32,8 +32,8 @@
 
 /* xmit state machine */
 #define XMSTATE_IDLE			0x0
-#define XMSTATE_R_HDR			0x1
-#define XMSTATE_W_HDR			0x2
+#define XMSTATE_CMD_HDR_INIT		0x1
+#define XMSTATE_CMD_HDR_XMIT		0x2
 #define XMSTATE_IMM_HDR			0x4
 #define XMSTATE_IMM_DATA		0x8
 #define XMSTATE_UNS_INIT		0x10
@@ -44,6 +44,8 @@
 #define XMSTATE_W_PAD			0x200
 #define XMSTATE_W_RESEND_PAD		0x400
 #define XMSTATE_W_RESEND_DATA_DIGEST	0x800
+#define XMSTATE_IMM_HDR_INIT		0x1000
+#define XMSTATE_SOL_HDR_INIT		0x2000
 
 #define ISCSI_PAD_LEN			4
 #define ISCSI_SG_TABLESIZE		SG_ALL
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 63981ed..63f0a15 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -125,6 +125,7 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 			MAX_COMMAND_SIZE - sc->cmd_len);
 
 	ctask->data_count = 0;
+	ctask->imm_count = 0;
 	if (sc->sc_data_direction == DMA_TO_DEVICE) {
 		hdr->flags |= ISCSI_FLAG_CMD_WRITE;
 		/*
@@ -141,7 +142,6 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 		 *
 		 *      pad_count       bytes to be sent as zero-padding
 		 */
-		ctask->imm_count = 0;
 		ctask->unsol_count = 0;
 		ctask->unsol_offset = 0;
 		ctask->unsol_datasn = 0;