[SCSI] iscsi tcp: fix iscsi xmit state machine

If iscsi_tcp partially sends a header, it would recalculate the
header size and readd the size of the digest (if header digests
are used).This would cause us to send sizeof(digest) extra bytes
when we sent the rest of the header.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

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

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;