3 files changed, 150 insertions, 116 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 1e722f5aabd4..0afdca2224c2 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 f909edbf61ee..b039160ebafd 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 63981edf9ab9..63f0a15d9887 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;