drivers/infiniband/ulp/iser/iser_initiator.c

   1 /*
   2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
   3  *
   4  * This software is available to you under a choice of one of two
   5  * licenses.  You may choose to be licensed under the terms of the GNU
   6  * General Public License (GPL) Version 2, available from the file
   7  * COPYING in the main directory of this source tree, or the
   8  * OpenIB.org BSD license below:
   9  *
  10  *     Redistribution and use in source and binary forms, with or
  11  *     without modification, are permitted provided that the following
  12  *     conditions are met:
  13  *
  14  *      - Redistributions of source code must retain the above
  15  *        copyright notice, this list of conditions and the following
  16  *        disclaimer.
  17  *
  18  *      - Redistributions in binary form must reproduce the above
  19  *        copyright notice, this list of conditions and the following
  20  *        disclaimer in the documentation and/or other materials
  21  *        provided with the distribution.
  22  *
  23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  30  * SOFTWARE.
  31  */
  32 #include <linux/kernel.h>
  33 #include <linux/slab.h>
  34 #include <linux/mm.h>
  35 #include <linux/scatterlist.h>
  36 #include <linux/kfifo.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39
  40 #include "iscsi_iser.h"
  41
  42 /* Register user buffer memory and initialize passive rdma
  43  *  dto descriptor. Total data size is stored in
  44  *  iser_task->data[ISER_DIR_IN].data_len
  45  */
  46 static int iser_prepare_read_cmd(struct iscsi_task *task,
  47                                  unsigned int edtl)
  48
  49 {
  50         struct iscsi_iser_task *iser_task = task->dd_data;
  51         struct iser_regd_buf *regd_buf;
  52         int err;
  53         struct iser_hdr *hdr = &iser_task->desc.iser_header;
  54         struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
  55
  56         err = iser_dma_map_task_data(iser_task,
  57                                      buf_in,
  58                                      ISER_DIR_IN,
  59                                      DMA_FROM_DEVICE);
  60         if (err)
  61                 return err;
  62
  63         if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
  64                 iser_err("Total data length: %ld, less than EDTL: "
  65                          "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
  66                          iser_task->data[ISER_DIR_IN].data_len, edtl,
  67                          task->itt, iser_task->iser_conn);
  68                 return -EINVAL;
  69         }
  70
  71         err = iser_reg_rdma_mem(iser_task,ISER_DIR_IN);
  72         if (err) {
  73                 iser_err("Failed to set up Data-IN RDMA\n");
  74                 return err;
  75         }
  76         regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
  77
  78         hdr->flags    |= ISER_RSV;
  79         hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
  80         hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
  81
  82         iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
  83                  task->itt, regd_buf->reg.rkey,
  84                  (unsigned long long)regd_buf->reg.va);
  85
  86         return 0;
  87 }
  88
  89 /* Register user buffer memory and initialize passive rdma
  90  *  dto descriptor. Total data size is stored in
  91  *  task->data[ISER_DIR_OUT].data_len
  92  */
  93 static int
  94 iser_prepare_write_cmd(struct iscsi_task *task,
  95                        unsigned int imm_sz,
  96                        unsigned int unsol_sz,
  97                        unsigned int edtl)
  98 {
  99         struct iscsi_iser_task *iser_task = task->dd_data;
 100         struct iser_regd_buf *regd_buf;
 101         int err;
 102         struct iser_hdr *hdr = &iser_task->desc.iser_header;
 103         struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
 104         struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
 105
 106         err = iser_dma_map_task_data(iser_task,
 107                                      buf_out,
 108                                      ISER_DIR_OUT,
 109                                      DMA_TO_DEVICE);
 110         if (err)
 111                 return err;
 112
 113         if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
 114                 iser_err("Total data length: %ld, less than EDTL: %d, "
 115                          "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
 116                          iser_task->data[ISER_DIR_OUT].data_len,
 117                          edtl, task->itt, task->conn);
 118                 return -EINVAL;
 119         }
 120
 121         err = iser_reg_rdma_mem(iser_task,ISER_DIR_OUT);
 122         if (err != 0) {
 123                 iser_err("Failed to register write cmd RDMA mem\n");
 124                 return err;
 125         }
 126
 127         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 128
 129         if (unsol_sz < edtl) {
 130                 hdr->flags     |= ISER_WSV;
 131                 hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
 132                 hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
 133
 134                 iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
 135                          "VA:%#llX + unsol:%d\n",
 136                          task->itt, regd_buf->reg.rkey,
 137                          (unsigned long long)regd_buf->reg.va, unsol_sz);
 138         }
 139
 140         if (imm_sz > 0) {
 141                 iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
 142                          task->itt, imm_sz);
 143                 tx_dsg->addr   = regd_buf->reg.va;
 144                 tx_dsg->length = imm_sz;
 145                 tx_dsg->lkey   = regd_buf->reg.lkey;
 146                 iser_task->desc.num_sge = 2;
 147         }
 148
 149         return 0;
 150 }
 151
 152 /* creates a new tx descriptor and adds header regd buffer */
 153 static void iser_create_send_desc(struct iser_conn      *ib_conn,
 154                                   struct iser_tx_desc   *tx_desc)
 155 {
 156         struct iser_device *device = ib_conn->device;
 157
 158         ib_dma_sync_single_for_cpu(device->ib_device,
 159                 tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
 160
 161         memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
 162         tx_desc->iser_header.flags = ISER_VER;
 163
 164         tx_desc->num_sge = 1;
 165
 166         if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
 167                 tx_desc->tx_sg[0].lkey = device->mr->lkey;
 168                 iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
 169         }
 170 }
 171
 172
 173 static int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
 174 {
 175         int i, j;
 176         u64 dma_addr;
 177         struct iser_rx_desc *rx_desc;
 178         struct ib_sge       *rx_sg;
 179         struct iser_device  *device = ib_conn->device;
 180
 181         ib_conn->rx_descs = kmalloc(ISER_QP_MAX_RECV_DTOS *
 182                                 sizeof(struct iser_rx_desc), GFP_KERNEL);
 183         if (!ib_conn->rx_descs)
 184                 goto rx_desc_alloc_fail;
 185
 186         rx_desc = ib_conn->rx_descs;
 187
 188         for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
 189                 dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
 190                                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 191                 if (ib_dma_mapping_error(device->ib_device, dma_addr))
 192                         goto rx_desc_dma_map_failed;
 193
 194                 rx_desc->dma_addr = dma_addr;
 195
 196                 rx_sg = &rx_desc->rx_sg;
 197                 rx_sg->addr   = rx_desc->dma_addr;
 198                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
 199                 rx_sg->lkey   = device->mr->lkey;
 200         }
 201
 202         ib_conn->rx_desc_head = 0;
 203         return 0;
 204
 205 rx_desc_dma_map_failed:
 206         rx_desc = ib_conn->rx_descs;
 207         for (j = 0; j < i; j++, rx_desc++)
 208                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 209                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 210         kfree(ib_conn->rx_descs);
 211         ib_conn->rx_descs = NULL;
 212 rx_desc_alloc_fail:
 213         iser_err("failed allocating rx descriptors / data buffers\n");
 214         return -ENOMEM;
 215 }
 216
 217 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
 218 {
 219         int i;
 220         struct iser_rx_desc *rx_desc;
 221         struct iser_device *device = ib_conn->device;
 222
 223         if (ib_conn->login_buf) {
 224                 ib_dma_unmap_single(device->ib_device, ib_conn->login_dma,
 225                         ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
 226                 kfree(ib_conn->login_buf);
 227         }
 228
 229         if (!ib_conn->rx_descs)
 230                 return;
 231
 232         rx_desc = ib_conn->rx_descs;
 233         for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)
 234                 ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
 235                         ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
 236         kfree(ib_conn->rx_descs);
 237 }
 238
 239 /**
 240  *  iser_conn_set_full_featured_mode - (iSER API)
 241  */
 242 int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
 243 {
 244         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 245
 246         iser_dbg("Initially post: %d\n", ISER_MIN_POSTED_RX);
 247
 248         /* Check that there is no posted recv or send buffers left - */
 249         /* they must be consumed during the login phase */
 250         BUG_ON(iser_conn->ib_conn->post_recv_buf_count != 0);
 251         BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
 252
 253         if (iser_alloc_rx_descriptors(iser_conn->ib_conn))
 254                 return -ENOMEM;
 255
 256         /* Initial post receive buffers */
 257         if (iser_post_recvm(iser_conn->ib_conn, ISER_MIN_POSTED_RX))
 258                 return -ENOMEM;
 259
 260         return 0;
 261 }
 262
 263 /**
 264  * iser_send_command - send command PDU
 265  */
 266 int iser_send_command(struct iscsi_conn *conn,
 267                       struct iscsi_task *task)
 268 {
 269         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 270         struct iscsi_iser_task *iser_task = task->dd_data;
 271         unsigned long edtl;
 272         int err;
 273         struct iser_data_buf *data_buf;
 274         struct iscsi_cmd *hdr =  (struct iscsi_cmd *)task->hdr;
 275         struct scsi_cmnd *sc  =  task->sc;
 276         struct iser_tx_desc *tx_desc = &iser_task->desc;
 277
 278         edtl = ntohl(hdr->data_length);
 279
 280         /* build the tx desc regd header and add it to the tx desc dto */
 281         tx_desc->type = ISCSI_TX_SCSI_COMMAND;
 282         iser_create_send_desc(iser_conn->ib_conn, tx_desc);
 283
 284         if (hdr->flags & ISCSI_FLAG_CMD_READ)
 285                 data_buf = &iser_task->data[ISER_DIR_IN];
 286         else
 287                 data_buf = &iser_task->data[ISER_DIR_OUT];
 288
 289         if (scsi_sg_count(sc)) { /* using a scatter list */
 290                 data_buf->buf  = scsi_sglist(sc);
 291                 data_buf->size = scsi_sg_count(sc);
 292         }
 293
 294         data_buf->data_len = scsi_bufflen(sc);
 295
 296         if (hdr->flags & ISCSI_FLAG_CMD_READ) {
 297                 err = iser_prepare_read_cmd(task, edtl);
 298                 if (err)
 299                         goto send_command_error;
 300         }
 301         if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
 302                 err = iser_prepare_write_cmd(task,
 303                                              task->imm_count,
 304                                              task->imm_count +
 305                                              task->unsol_r2t.data_length,
 306                                              edtl);
 307                 if (err)
 308                         goto send_command_error;
 309         }
 310
 311         iser_task->status = ISER_TASK_STATUS_STARTED;
 312
 313         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 314         if (!err)
 315                 return 0;
 316
 317 send_command_error:
 318         iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
 319         return err;
 320 }
 321
 322 /**
 323  * iser_send_data_out - send data out PDU
 324  */
 325 int iser_send_data_out(struct iscsi_conn *conn,
 326                        struct iscsi_task *task,
 327                        struct iscsi_data *hdr)
 328 {
 329         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 330         struct iscsi_iser_task *iser_task = task->dd_data;
 331         struct iser_tx_desc *tx_desc = NULL;
 332         struct iser_regd_buf *regd_buf;
 333         unsigned long buf_offset;
 334         unsigned long data_seg_len;
 335         uint32_t itt;
 336         int err = 0;
 337         struct ib_sge *tx_dsg;
 338
 339         itt = (__force uint32_t)hdr->itt;
 340         data_seg_len = ntoh24(hdr->dlength);
 341         buf_offset   = ntohl(hdr->offset);
 342
 343         iser_dbg("%s itt %d dseg_len %d offset %d\n",
 344                  __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
 345
 346         tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
 347         if (tx_desc == NULL) {
 348                 iser_err("Failed to alloc desc for post dataout\n");
 349                 return -ENOMEM;
 350         }
 351
 352         tx_desc->type = ISCSI_TX_DATAOUT;
 353         tx_desc->iser_header.flags = ISER_VER;
 354         memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
 355
 356         /* build the tx desc */
 357         iser_initialize_task_headers(task, tx_desc);
 358
 359         regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
 360         tx_dsg = &tx_desc->tx_sg[1];
 361         tx_dsg->addr    = regd_buf->reg.va + buf_offset;
 362         tx_dsg->length  = data_seg_len;
 363         tx_dsg->lkey    = regd_buf->reg.lkey;
 364         tx_desc->num_sge = 2;
 365
 366         if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
 367                 iser_err("Offset:%ld & DSL:%ld in Data-Out "
 368                          "inconsistent with total len:%ld, itt:%d\n",
 369                          buf_offset, data_seg_len,
 370                          iser_task->data[ISER_DIR_OUT].data_len, itt);
 371                 err = -EINVAL;
 372                 goto send_data_out_error;
 373         }
 374         iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
 375                  itt, buf_offset, data_seg_len);
 376
 377
 378         err = iser_post_send(iser_conn->ib_conn, tx_desc);
 379         if (!err)
 380                 return 0;
 381
 382 send_data_out_error:
 383         kmem_cache_free(ig.desc_cache, tx_desc);
 384         iser_err("conn %p failed err %d\n",conn, err);
 385         return err;
 386 }
 387
 388 int iser_send_control(struct iscsi_conn *conn,
 389                       struct iscsi_task *task)
 390 {
 391         struct iscsi_iser_conn *iser_conn = conn->dd_data;
 392         struct iscsi_iser_task *iser_task = task->dd_data;
 393         struct iser_tx_desc *mdesc = &iser_task->desc;
 394         unsigned long data_seg_len;
 395         int err = 0;
 396         struct iser_device *device;
 397
 398         /* build the tx desc regd header and add it to the tx desc dto */
 399         mdesc->type = ISCSI_TX_CONTROL;
 400         iser_create_send_desc(iser_conn->ib_conn, mdesc);
 401
 402         device = iser_conn->ib_conn->device;
 403
 404         data_seg_len = ntoh24(task->hdr->dlength);
 405
 406         if (data_seg_len > 0) {
 407                 struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
 408                 if (task != conn->login_task) {
 409                         iser_err("data present on non login task!!!\n");
 410                         goto send_control_error;
 411                 }
 412                 memcpy(iser_conn->ib_conn->login_buf, task->data,
 413                                                         task->data_count);
 414                 tx_dsg->addr    = iser_conn->ib_conn->login_dma;
 415                 tx_dsg->length  = data_seg_len;
 416                 tx_dsg->lkey    = device->mr->lkey;
 417                 mdesc->num_sge = 2;
 418         }
 419
 420         if (task == conn->login_task) {
 421                 err = iser_post_recvl(iser_conn->ib_conn);
 422                 if (err)
 423                         goto send_control_error;
 424         }
 425
 426         err = iser_post_send(iser_conn->ib_conn, mdesc);
 427         if (!err)
 428                 return 0;
 429
 430 send_control_error:
 431         iser_err("conn %p failed err %d\n",conn, err);
 432         return err;
 433 }
 434
 435 /**
 436  * iser_rcv_dto_completion - recv DTO completion
 437  */
 438 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
 439                          unsigned long rx_xfer_len,
 440                          struct iser_conn *ib_conn)
 441 {
 442         struct iscsi_iser_conn *conn = ib_conn->iser_conn;
 443         struct iscsi_hdr *hdr;
 444         u64 rx_dma;
 445         int rx_buflen, outstanding, count, err;
 446
 447         /* differentiate between login to all other PDUs */
 448         if ((char *)rx_desc == ib_conn->login_buf) {
 449                 rx_dma = ib_conn->login_dma;
 450                 rx_buflen = ISER_RX_LOGIN_SIZE;
 451         } else {
 452                 rx_dma = rx_desc->dma_addr;
 453                 rx_buflen = ISER_RX_PAYLOAD_SIZE;
 454         }
 455
 456         ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
 457                         rx_buflen, DMA_FROM_DEVICE);
 458
 459         hdr = &rx_desc->iscsi_header;
 460
 461         iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
 462                         hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
 463
 464         iscsi_iser_recv(conn->iscsi_conn, hdr,
 465                 rx_desc->data, rx_xfer_len - ISER_HEADERS_LEN);
 466
 467         ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
 468                         rx_buflen, DMA_FROM_DEVICE);
 469
 470         /* decrementing conn->post_recv_buf_count only --after-- freeing the   *
 471          * task eliminates the need to worry on tasks which are completed in   *
 472          * parallel to the execution of iser_conn_term. So the code that waits *
 473          * for the posted rx bufs refcount to become zero handles everything   */
 474         conn->ib_conn->post_recv_buf_count--;
 475
 476         if (rx_dma == ib_conn->login_dma)
 477                 return;
 478
 479         outstanding = ib_conn->post_recv_buf_count;
 480         if (outstanding + ISER_MIN_POSTED_RX <= ISER_QP_MAX_RECV_DTOS) {
 481                 count = min(ISER_QP_MAX_RECV_DTOS - outstanding,
 482                                                 ISER_MIN_POSTED_RX);
 483                 err = iser_post_recvm(ib_conn, count);
 484                 if (err)
 485                         iser_err("posting %d rx bufs err %d\n", count, err);
 486         }
 487 }
 488
 489 void iser_snd_completion(struct iser_tx_desc *tx_desc,
 490                         struct iser_conn *ib_conn)
 491 {
 492         struct iscsi_task *task;
 493         struct iser_device *device = ib_conn->device;
 494
 495         if (tx_desc->type == ISCSI_TX_DATAOUT) {
 496                 ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
 497                                         ISER_HEADERS_LEN, DMA_TO_DEVICE);
 498                 kmem_cache_free(ig.desc_cache, tx_desc);
 499         }
 500
 501         atomic_dec(&ib_conn->post_send_buf_count);
 502
 503         if (tx_desc->type == ISCSI_TX_CONTROL) {
 504                 /* this arithmetic is legal by libiscsi dd_data allocation */
 505                 task = (void *) ((long)(void *)tx_desc -
 506                                   sizeof(struct iscsi_task));
 507                 if (task->hdr->itt == RESERVED_ITT)
 508                         iscsi_put_task(task);
 509         }
 510 }
 511
 512 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
 513
 514 {
 515         iser_task->status = ISER_TASK_STATUS_INIT;
 516
 517         iser_task->dir[ISER_DIR_IN] = 0;
 518         iser_task->dir[ISER_DIR_OUT] = 0;
 519
 520         iser_task->data[ISER_DIR_IN].data_len  = 0;
 521         iser_task->data[ISER_DIR_OUT].data_len = 0;
 522
 523         memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
 524                sizeof(struct iser_regd_buf));
 525         memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
 526                sizeof(struct iser_regd_buf));
 527 }
 528
 529 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
 530 {
 531         int is_rdma_aligned = 1;
 532         struct iser_regd_buf *regd;
 533
 534         /* if we were reading, copy back to unaligned sglist,
 535          * anyway dma_unmap and free the copy
 536          */
 537         if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
 538                 is_rdma_aligned = 0;
 539                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
 540         }
 541         if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
 542                 is_rdma_aligned = 0;
 543                 iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
 544         }
 545
 546         if (iser_task->dir[ISER_DIR_IN]) {
 547                 regd = &iser_task->rdma_regd[ISER_DIR_IN];
 548                 if (regd->reg.is_fmr)
 549                         iser_unreg_mem(&regd->reg);
 550         }
 551
 552         if (iser_task->dir[ISER_DIR_OUT]) {
 553                 regd = &iser_task->rdma_regd[ISER_DIR_OUT];
 554                 if (regd->reg.is_fmr)
 555                         iser_unreg_mem(&regd->reg);
 556         }
 557
 558        /* if the data was unaligned, it was already unmapped and then copied */
 559        if (is_rdma_aligned)
 560                 iser_dma_unmap_task_data(iser_task);
 561 }