[SCSI] iscsi_tcp: convert to use the data buffer accessors

- remove the unnecessary map_single path.

- convert to use the new accessors for the sg lists and the
parameters.

TODO: use scsi_for_each_sg().

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 48 insertions, 89 deletions

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index d5a6527b3b3d..aebcd5fcdc55 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -237,10 +237,10 @@ 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 > sc->request_bufflen) {
+        if (tcp_ctask->data_offset + tcp_conn->in.datalen > scsi_bufflen(sc)) {
                 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);
+                          tcp_conn->in.datalen, scsi_bufflen(sc));
                 return ISCSI_ERR_DATA_OFFSET;
         }
 
@@ -250,14 +250,14 @@ iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                         int res_count = be32_to_cpu(rhdr->residual_count);
 
                         if (res_count > 0 &&
-                            res_count <= sc->request_bufflen) {
-                                sc->resid = res_count;
+                            res_count <= scsi_bufflen(sc)) {
+                                scsi_set_resid(sc, res_count);
                                 sc->result = (DID_OK << 16) | rhdr->cmd_status;
                         } else
                                 sc->result = (DID_BAD_TARGET << 16) |
                                         rhdr->cmd_status;
                 } else if (rhdr->flags & ISCSI_FLAG_DATA_OVERFLOW) {
-                        sc->resid = be32_to_cpu(rhdr->residual_count);
+                        scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
                 } else
                         sc->result = (DID_OK << 16) | rhdr->cmd_status;
@@ -285,6 +285,8 @@ iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
 {
         struct iscsi_data *hdr;
         struct scsi_cmnd *sc = ctask->sc;
+        int i, sg_count = 0;
+        struct scatterlist *sg;
 
         hdr = &r2t->dtask.hdr;
         memset(hdr, 0, sizeof(struct iscsi_data));
@@ -312,39 +314,30 @@ iscsi_solicit_data_init(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         iscsi_buf_init_iov(&r2t->headbuf, (char*)hdr,
                            sizeof(struct iscsi_hdr));
 
-        if (sc->use_sg) {
-                int i, sg_count = 0;
-                struct scatterlist *sg = sc->request_buffer;
-
-                r2t->sg = NULL;
-                for (i = 0; i < sc->use_sg; i++, sg += 1) {
-                        /* FIXME: prefetch ? */
-                        if (sg_count + sg->length > r2t->data_offset) {
-                                int page_offset;
+        sg = scsi_sglist(sc);
+        r2t->sg = NULL;
+        for (i = 0; i < scsi_sg_count(sc); i++, sg += 1) {
+                /* FIXME: prefetch ? */
+                if (sg_count + sg->length > r2t->data_offset) {
+                        int page_offset;
 
-                                /* sg page found! */
+                        /* sg page found! */
 
-                                /* offset within this page */
-                                page_offset = r2t->data_offset - sg_count;
+                        /* offset within this page */
+                        page_offset = r2t->data_offset - sg_count;
 
-                                /* fill in this buffer */
-                                iscsi_buf_init_sg(&r2t->sendbuf, sg);
-                                r2t->sendbuf.sg.offset += page_offset;
-                                r2t->sendbuf.sg.length -= page_offset;
+                        /* fill in this buffer */
+                        iscsi_buf_init_sg(&r2t->sendbuf, sg);
+                        r2t->sendbuf.sg.offset += page_offset;
+                        r2t->sendbuf.sg.length -= page_offset;
 
-                                /* xmit logic will continue with next one */
-                                r2t->sg = sg + 1;
-                                break;
-                        }
-                        sg_count += sg->length;
+                        /* xmit logic will continue with next one */
+                        r2t->sg = sg + 1;
+                        break;
                 }
-                BUG_ON(r2t->sg == NULL);
-        } else {
-                iscsi_buf_init_iov(&r2t->sendbuf,
-                            (char*)sc->request_buffer + r2t->data_offset,
-                            r2t->data_count);
-                r2t->sg = NULL;
+                sg_count += sg->length;
         }
+        BUG_ON(r2t->sg == NULL);
 }
 
 /**
@@ -404,11 +397,11 @@ 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->sc->request_bufflen) {
+        if (r2t->data_offset + r2t->data_length > scsi_bufflen(ctask->sc)) {
                 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->sc->request_bufflen);
+                       r2t->data_offset, scsi_bufflen(ctask->sc));
                 return ISCSI_ERR_DATALEN;
         }
 
@@ -612,7 +605,7 @@ 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->sc->request_bufflen);
+        BUG_ON(tcp_ctask->sent + size > scsi_bufflen(ctask->sc));
 
         rc = skb_copy_bits(tcp_conn->in.skb, tcp_conn->in.offset,
                            (char*)buf + (offset + tcp_conn->data_copied), size);
@@ -710,25 +703,8 @@ static int iscsi_scsi_data_in(struct iscsi_conn *conn)
 
         BUG_ON((void*)ctask != sc->SCp.ptr);
 
-        /*
-         * copying Data-In into the Scsi_Cmnd
-         */
-        if (!sc->use_sg) {
-                i = ctask->data_count;
-                rc = iscsi_ctask_copy(tcp_conn, ctask, sc->request_buffer,
-                                      sc->request_bufflen,
-                                      tcp_ctask->data_offset);
-                if (rc == -EAGAIN)
-                        return rc;
-                if (conn->datadgst_en)
-                        iscsi_recv_digest_update(tcp_conn, sc->request_buffer,
-                                                 i);
-                rc = 0;
-                goto done;
-        }
-
         offset = tcp_ctask->data_offset;
-        sg = sc->request_buffer;
+        sg = scsi_sglist(sc);
 
         if (tcp_ctask->data_offset)
                 for (i = 0; i < tcp_ctask->sg_count; i++)
@@ -737,7 +713,7 @@ static int iscsi_scsi_data_in(struct iscsi_conn *conn)
         if (offset < 0)
                 offset = 0;
 
-        for (i = tcp_ctask->sg_count; i < sc->use_sg; i++) {
+        for (i = tcp_ctask->sg_count; i < scsi_sg_count(sc); i++) {
                 char *dest;
 
                 dest = kmap_atomic(sg[i].page, KM_SOFTIRQ0);
@@ -782,7 +758,6 @@ static int iscsi_scsi_data_in(struct iscsi_conn *conn)
         }
         BUG_ON(ctask->data_count);
 
-done:
         /* check for non-exceptional status */
         if (tcp_conn->in.hdr->flags & ISCSI_FLAG_DATA_STATUS) {
                 debug_scsi("done [sc %lx res %d itt 0x%x flags 0x%x]\n",
@@ -1241,7 +1216,6 @@ iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
                         struct iscsi_r2t_info *r2t, int left)
 {
         struct iscsi_data *hdr;
-        struct scsi_cmnd *sc = ctask->sc;
         int new_offset;
 
         hdr = &r2t->dtask.hdr;
@@ -1271,15 +1245,8 @@ iscsi_solicit_data_cont(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         if (iscsi_buf_left(&r2t->sendbuf))
                 return;
 
-        if (sc->use_sg) {
-                iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
-                r2t->sg += 1;
-        } else {
-                iscsi_buf_init_iov(&r2t->sendbuf,
-                            (char*)sc->request_buffer + new_offset,
-                            r2t->data_count);
-                r2t->sg = NULL;
-        }
+        iscsi_buf_init_sg(&r2t->sendbuf, r2t->sg);
+        r2t->sg += 1;
 }
 
 static void iscsi_set_padding(struct iscsi_tcp_cmd_task *tcp_ctask,
@@ -1408,23 +1375,15 @@ iscsi_send_cmd_hdr(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask)
                 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;
-                        }
+                        struct scatterlist *sg = scsi_sglist(sc);
+
+                        iscsi_buf_init_sg(&tcp_ctask->sendbuf, sg);
+                        tcp_ctask->sg = sg + 1;
+                        tcp_ctask->bad_sg = sg + scsi_sg_count(sc);
 
                         debug_scsi("cmd [itt 0x%x total %d imm_data %d "
                                    "unsol count %d, unsol offset %d]\n",
-                                   ctask->itt, sc->request_bufflen,
+                                   ctask->itt, scsi_bufflen(sc),
                                    ctask->imm_count, ctask->unsol_count,
                                    ctask->unsol_offset);
                 }
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 865dd5739f0e..4d85ce100192 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -140,7 +140,7 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
         hdr->flags = ISCSI_ATTR_SIMPLE;
         int_to_scsilun(sc->device->lun, (struct scsi_lun *)hdr->lun);
         hdr->itt = build_itt(ctask->itt, conn->id, session->age);
-        hdr->data_length = cpu_to_be32(sc->request_bufflen);
+        hdr->data_length = cpu_to_be32(scsi_bufflen(sc));
         hdr->cmdsn = cpu_to_be32(session->cmdsn);
         session->cmdsn++;
         hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
@@ -172,11 +172,11 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
                 ctask->unsol_datasn = 0;
 
                 if (session->imm_data_en) {
-                        if (sc->request_bufflen >= session->first_burst)
+                        if (scsi_bufflen(sc) >= session->first_burst)
                                 ctask->imm_count = min(session->first_burst,
                                                         conn->max_xmit_dlength);
                         else
-                                ctask->imm_count = min(sc->request_bufflen,
+                                ctask->imm_count = min(scsi_bufflen(sc),
                                                         conn->max_xmit_dlength);
                         hton24(ctask->hdr->dlength, ctask->imm_count);
                 } else
@@ -184,7 +184,7 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
 
                 if (!session->initial_r2t_en) {
                         ctask->unsol_count = min((session->first_burst),
-                                (sc->request_bufflen)) - ctask->imm_count;
+                                (scsi_bufflen(sc))) - ctask->imm_count;
                         ctask->unsol_offset = ctask->imm_count;
                 }
 
@@ -204,7 +204,7 @@ static void iscsi_prep_scsi_cmd_pdu(struct iscsi_cmd_task *ctask)
         debug_scsi("iscsi prep [%s cid %d sc %p cdb 0x%x itt 0x%x len %d "
                 "cmdsn %d win %d]\n",
                 sc->sc_data_direction == DMA_TO_DEVICE ? "write" : "read",
-                conn->id, sc, sc->cmnd[0], ctask->itt, sc->request_bufflen,
+                conn->id, sc, sc->cmnd[0], ctask->itt, scsi_bufflen(sc),
                 session->cmdsn, session->max_cmdsn - session->exp_cmdsn + 1);
 }
 
@@ -297,14 +297,14 @@ invalid_datalen:
         if (rhdr->flags & ISCSI_FLAG_CMD_UNDERFLOW) {
                 int res_count = be32_to_cpu(rhdr->residual_count);
 
-                if (res_count > 0 && res_count <= sc->request_bufflen)
-                        sc->resid = res_count;
+                if (res_count > 0 && res_count <= scsi_bufflen(sc))
+                        scsi_set_resid(sc, res_count);
                 else
                         sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
         } else if (rhdr->flags & ISCSI_FLAG_CMD_BIDI_UNDERFLOW)
                 sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
         else if (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW)
-                sc->resid = be32_to_cpu(rhdr->residual_count);
+                scsi_set_resid(sc, be32_to_cpu(rhdr->residual_count));
 
 out:
         debug_scsi("done [sc %lx res %d itt 0x%x]\n",
@@ -876,7 +876,7 @@ fault:
         printk(KERN_ERR "iscsi: cmd 0x%x is not queued (%d)\n",
                sc->cmnd[0], reason);
         sc->result = (DID_NO_CONNECT << 16);
-        sc->resid = sc->request_bufflen;
+        scsi_set_resid(sc, scsi_bufflen(sc));
         sc->scsi_done(sc);
         return 0;
 }
@@ -1145,7 +1145,7 @@ static void fail_command(struct iscsi_conn *conn, struct iscsi_cmd_task *ctask,
         iscsi_ctask_mtask_cleanup(ctask);
 
         sc->result = err;
-        sc->resid = sc->request_bufflen;
+        scsi_set_resid(sc, scsi_bufflen(sc));
         if (conn->ctask == ctask)
                 conn->ctask = NULL;
         /* release ref from queuecommand */