[SCSI] iscsi: Some fixes in preparation for bidirectional support - total_length

- Remove shadow of request length from struct iscsi_cmd_task.
- change all users to use scsi_cmnd->request_bufflen directly

(With bidi we will use scsi-ml API to retrieve in/out length)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 16 insertions, 14 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 17fc79c408a2..b2827d112cb0 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -216,6 +216,7 @@ iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
         struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
         struct iscsi_session *session = conn->session;
+        struct scsi_cmnd *sc = ctask->sc;
         int datasn = be32_to_cpu(rhdr->datasn);
 
         rc = iscsi_check_assign_cmdsn(session, (struct iscsi_nopin*)rhdr);
@@ -238,12 +239,14 @@ iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
         tcp_ctask->exp_datasn++;
 
         tcp_ctask->data_offset = be32_to_cpu(rhdr->offset);
-        if (tcp_ctask->data_offset + tcp_conn->in.datalen > ctask->total_length)
+        if (tcp_ctask->data_offset + tcp_conn->in.datalen > sc->request_bufflen) {
+                debug_tcp("%s: data_offset(%d) + data_len(%d) > total_length_in(%d)\n",
+                          __FUNCTION__, tcp_ctask->data_offset,
+                          tcp_conn->in.datalen, sc->request_bufflen);
                 return ISCSI_ERR_DATA_OFFSET;
+        }
 
         if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
-                struct scsi_cmnd *sc = ctask->sc;
-
                 conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
                 if (rhdr->flags & ISCSI_FLAG_DATA_UNDERFLOW) {
                         int res_count = be32_to_cpu(rhdr->residual_count);
@@ -405,11 +408,11 @@ iscsi_r2t_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                             r2t->data_length, session->max_burst);
 
         r2t->data_offset = be32_to_cpu(rhdr->data_offset);
-        if (r2t->data_offset + r2t->data_length > ctask->total_length) {
+        if (r2t->data_offset + r2t->data_length > ctask->sc->request_bufflen) {
                 spin_unlock(&session->lock);
                 printk(KERN_ERR "iscsi_tcp: invalid R2T with data len %u at "
                        "offset %u and total length %d\n", r2t->data_length,
-                       r2t->data_offset, ctask->total_length);
+                       r2t->data_offset, ctask->sc->request_bufflen);
                 return ISCSI_ERR_DATALEN;
         }
 
@@ -604,7 +607,7 @@ iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
 {
         struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
         int buf_left = buf_size - (tcp_conn->data_copied + offset);
-        int size = min(tcp_conn->in.copy, buf_left);
+        unsigned size = min(tcp_conn->in.copy, buf_left);
         int rc;
 
         size = min(size, ctask->data_count);
@@ -613,7 +616,7 @@ iscsi_ctask_copy(struct iscsi_tcp_conn *tcp_conn, struct iscsi_cmd_task *ctask,
                size, tcp_conn->in.offset, tcp_conn->in.copied);
 
         BUG_ON(size <= 0);
-        BUG_ON(tcp_ctask->sent + size > ctask->total_length);
+        BUG_ON(tcp_ctask->sent + size > ctask->sc->request_bufflen);
 
         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
                            (char*)buf + (offset + tcp_conn->data_copied), size);
@@ -1292,7 +1295,7 @@ iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
 
         if (sc->sc_data_direction == DMA_TO_DEVICE) {
                 tcp_ctask->xmstate = XMSTATE_W_HDR;
-                BUG_ON(ctask->total_length == 0);
+                BUG_ON(sc->request_bufflen == 0);
 
                 if (sc->use_sg) {
                         struct scatterlist *sg = sc->request_buffer;
@@ -1309,7 +1312,7 @@ iscsi_tcp_cmd_init(struct iscsi_cmd_task *ctask)
                 }
                 debug_scsi("cmd [itt 0x%x total %d imm_data %d "
                            "unsol count %d, unsol offset %d]\n",
-                           ctask->itt, ctask->total_length, ctask->imm_count,
+                           ctask->itt, sc->request_bufflen, ctask->imm_count,
                            ctask->unsol_count, ctask->unsol_offset);
         } else
                 tcp_ctask->xmstate = XMSTATE_R_HDR;
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index eb5113607958..0a9c64e9ce8b 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -147,19 +147,19 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
                 ctask->unsol_datasn = 0;
 
                 if (session->imm_data_en) {
-                        if (ctask->total_length >= session->first_burst)
+                        if (sc->request_bufflen >= session->first_burst)
                                 ctask->imm_count = min(session->first_burst,
                                                         conn->max_xmit_dlength);
                         else
-                                ctask->imm_count = min(ctask->total_length,
+                                ctask->imm_count = min(sc->request_bufflen,
                                                         conn->max_xmit_dlength);
                         hton24(ctask->hdr->dlength, ctask->imm_count);
                 } else
                         zero_data(ctask->hdr->dlength);
 
                 if (!session->initial_r2t_en) {
-                        ctask->unsol_count = min(session->first_burst,
-                                ctask->total_length) - ctask->imm_count;
+                        ctask->unsol_count = min((session->first_burst),
+                                (sc->request_bufflen)) - ctask->imm_count;
                         ctask->unsol_offset = ctask->imm_count;
                 }
 
@@ -815,7 +815,6 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
         ctask->conn = conn;
         ctask->sc = sc;
         INIT_LIST_HEAD(&ctask->running);
-        ctask->total_length = sc->request_bufflen;
         iscsi_prep_scsi_cmd_pdu(ctask);
 
         session->tt->init_cmd_task(ctask);