1 /*
2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3  * Copyright (c) 2013 Mellanox Technologies. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *	- Redistributions of source code must retain the above
16  *	  copyright notice, this list of conditions and the following
17  *	  disclaimer.
18  *
19  *	- Redistributions in binary form must reproduce the above
20  *	  copyright notice, this list of conditions and the following
21  *	  disclaimer in the documentation and/or other materials
22  *	  provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/mm.h>
36 #include <linux/scatterlist.h>
37 #include <linux/kfifo.h>
38 #include <scsi/scsi_cmnd.h>
39 #include <scsi/scsi_host.h>
40 
41 #include "iscsi_iser.h"
42 
43 /* Register user buffer memory and initialize passive rdma
44  *  dto descriptor. Total data size is stored in
45  *  iser_task->data[ISER_DIR_IN].data_len
46  */
47 static int iser_prepare_read_cmd(struct iscsi_task *task,
48 				 unsigned int edtl)
49 
50 {
51 	struct iscsi_iser_task *iser_task = task->dd_data;
52 	struct iser_regd_buf *regd_buf;
53 	int err;
54 	struct iser_hdr *hdr = &iser_task->desc.iser_header;
55 	struct iser_data_buf *buf_in = &iser_task->data[ISER_DIR_IN];
56 
57 	err = iser_dma_map_task_data(iser_task,
58 				     buf_in,
59 				     ISER_DIR_IN,
60 				     DMA_FROM_DEVICE);
61 	if (err)
62 		return err;
63 
64 	if (edtl > iser_task->data[ISER_DIR_IN].data_len) {
65 		iser_err("Total data length: %ld, less than EDTL: "
66 			 "%d, in READ cmd BHS itt: %d, conn: 0x%p\n",
67 			 iser_task->data[ISER_DIR_IN].data_len, edtl,
68 			 task->itt, iser_task->iser_conn);
69 		return -EINVAL;
70 	}
71 
72 	err = iser_reg_rdma_mem(iser_task,ISER_DIR_IN);
73 	if (err) {
74 		iser_err("Failed to set up Data-IN RDMA\n");
75 		return err;
76 	}
77 	regd_buf = &iser_task->rdma_regd[ISER_DIR_IN];
78 
79 	hdr->flags    |= ISER_RSV;
80 	hdr->read_stag = cpu_to_be32(regd_buf->reg.rkey);
81 	hdr->read_va   = cpu_to_be64(regd_buf->reg.va);
82 
83 	iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
84 		 task->itt, regd_buf->reg.rkey,
85 		 (unsigned long long)regd_buf->reg.va);
86 
87 	return 0;
88 }
89 
90 /* Register user buffer memory and initialize passive rdma
91  *  dto descriptor. Total data size is stored in
92  *  task->data[ISER_DIR_OUT].data_len
93  */
94 static int
95 iser_prepare_write_cmd(struct iscsi_task *task,
96 		       unsigned int imm_sz,
97 		       unsigned int unsol_sz,
98 		       unsigned int edtl)
99 {
100 	struct iscsi_iser_task *iser_task = task->dd_data;
101 	struct iser_regd_buf *regd_buf;
102 	int err;
103 	struct iser_hdr *hdr = &iser_task->desc.iser_header;
104 	struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
105 	struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
106 
107 	err = iser_dma_map_task_data(iser_task,
108 				     buf_out,
109 				     ISER_DIR_OUT,
110 				     DMA_TO_DEVICE);
111 	if (err)
112 		return err;
113 
114 	if (edtl > iser_task->data[ISER_DIR_OUT].data_len) {
115 		iser_err("Total data length: %ld, less than EDTL: %d, "
116 			 "in WRITE cmd BHS itt: %d, conn: 0x%p\n",
117 			 iser_task->data[ISER_DIR_OUT].data_len,
118 			 edtl, task->itt, task->conn);
119 		return -EINVAL;
120 	}
121 
122 	err = iser_reg_rdma_mem(iser_task,ISER_DIR_OUT);
123 	if (err != 0) {
124 		iser_err("Failed to register write cmd RDMA mem\n");
125 		return err;
126 	}
127 
128 	regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
129 
130 	if (unsol_sz < edtl) {
131 		hdr->flags     |= ISER_WSV;
132 		hdr->write_stag = cpu_to_be32(regd_buf->reg.rkey);
133 		hdr->write_va   = cpu_to_be64(regd_buf->reg.va + unsol_sz);
134 
135 		iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X "
136 			 "VA:%#llX + unsol:%d\n",
137 			 task->itt, regd_buf->reg.rkey,
138 			 (unsigned long long)regd_buf->reg.va, unsol_sz);
139 	}
140 
141 	if (imm_sz > 0) {
142 		iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
143 			 task->itt, imm_sz);
144 		tx_dsg->addr   = regd_buf->reg.va;
145 		tx_dsg->length = imm_sz;
146 		tx_dsg->lkey   = regd_buf->reg.lkey;
147 		iser_task->desc.num_sge = 2;
148 	}
149 
150 	return 0;
151 }
152 
153 /* creates a new tx descriptor and adds header regd buffer */
154 static void iser_create_send_desc(struct iser_conn	*ib_conn,
155 				  struct iser_tx_desc	*tx_desc)
156 {
157 	struct iser_device *device = ib_conn->device;
158 
159 	ib_dma_sync_single_for_cpu(device->ib_device,
160 		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
161 
162 	memset(&tx_desc->iser_header, 0, sizeof(struct iser_hdr));
163 	tx_desc->iser_header.flags = ISER_VER;
164 
165 	tx_desc->num_sge = 1;
166 
167 	if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
168 		tx_desc->tx_sg[0].lkey = device->mr->lkey;
169 		iser_dbg("sdesc %p lkey mismatch, fixing\n", tx_desc);
170 	}
171 }
172 
173 
174 int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
175 {
176 	int i, j;
177 	u64 dma_addr;
178 	struct iser_rx_desc *rx_desc;
179 	struct ib_sge       *rx_sg;
180 	struct iser_device  *device = ib_conn->device;
181 
182 	ib_conn->rx_descs = kmalloc(ISER_QP_MAX_RECV_DTOS *
183 				sizeof(struct iser_rx_desc), GFP_KERNEL);
184 	if (!ib_conn->rx_descs)
185 		goto rx_desc_alloc_fail;
186 
187 	rx_desc = ib_conn->rx_descs;
188 
189 	for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)  {
190 		dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
191 					ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
192 		if (ib_dma_mapping_error(device->ib_device, dma_addr))
193 			goto rx_desc_dma_map_failed;
194 
195 		rx_desc->dma_addr = dma_addr;
196 
197 		rx_sg = &rx_desc->rx_sg;
198 		rx_sg->addr   = rx_desc->dma_addr;
199 		rx_sg->length = ISER_RX_PAYLOAD_SIZE;
200 		rx_sg->lkey   = device->mr->lkey;
201 	}
202 
203 	ib_conn->rx_desc_head = 0;
204 	return 0;
205 
206 rx_desc_dma_map_failed:
207 	rx_desc = ib_conn->rx_descs;
208 	for (j = 0; j < i; j++, rx_desc++)
209 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
210 			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
211 	kfree(ib_conn->rx_descs);
212 	ib_conn->rx_descs = NULL;
213 rx_desc_alloc_fail:
214 	iser_err("failed allocating rx descriptors / data buffers\n");
215 	return -ENOMEM;
216 }
217 
218 void iser_free_rx_descriptors(struct iser_conn *ib_conn)
219 {
220 	int i;
221 	struct iser_rx_desc *rx_desc;
222 	struct iser_device *device = ib_conn->device;
223 
224 	if (!ib_conn->rx_descs)
225 		return;
226 
227 	rx_desc = ib_conn->rx_descs;
228 	for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)
229 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
230 			ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
231 	kfree(ib_conn->rx_descs);
232 }
233 
234 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
235 {
236 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
237 
238 	iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
239 	/* check if this is the last login - going to full feature phase */
240 	if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
241 		return 0;
242 
243 	/*
244 	 * Check that there is one posted recv buffer (for the last login
245 	 * response) and no posted send buffers left - they must have been
246 	 * consumed during previous login phases.
247 	 */
248 	WARN_ON(iser_conn->ib_conn->post_recv_buf_count != 1);
249 	WARN_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);
250 
251 	iser_dbg("Initially post: %d\n", ISER_MIN_POSTED_RX);
252 	/* Initial post receive buffers */
253 	if (iser_post_recvm(iser_conn->ib_conn, ISER_MIN_POSTED_RX))
254 		return -ENOMEM;
255 
256 	return 0;
257 }
258 
259 /**
260  * iser_send_command - send command PDU
261  */
262 int iser_send_command(struct iscsi_conn *conn,
263 		      struct iscsi_task *task)
264 {
265 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
266 	struct iscsi_iser_task *iser_task = task->dd_data;
267 	unsigned long edtl;
268 	int err;
269 	struct iser_data_buf *data_buf;
270 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
271 	struct scsi_cmnd *sc  =  task->sc;
272 	struct iser_tx_desc *tx_desc = &iser_task->desc;
273 
274 	edtl = ntohl(hdr->data_length);
275 
276 	/* build the tx desc regd header and add it to the tx desc dto */
277 	tx_desc->type = ISCSI_TX_SCSI_COMMAND;
278 	iser_create_send_desc(iser_conn->ib_conn, tx_desc);
279 
280 	if (hdr->flags & ISCSI_FLAG_CMD_READ)
281 		data_buf = &iser_task->data[ISER_DIR_IN];
282 	else
283 		data_buf = &iser_task->data[ISER_DIR_OUT];
284 
285 	if (scsi_sg_count(sc)) { /* using a scatter list */
286 		data_buf->buf  = scsi_sglist(sc);
287 		data_buf->size = scsi_sg_count(sc);
288 	}
289 
290 	data_buf->data_len = scsi_bufflen(sc);
291 
292 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
293 		err = iser_prepare_read_cmd(task, edtl);
294 		if (err)
295 			goto send_command_error;
296 	}
297 	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
298 		err = iser_prepare_write_cmd(task,
299 					     task->imm_count,
300 				             task->imm_count +
301 					     task->unsol_r2t.data_length,
302 					     edtl);
303 		if (err)
304 			goto send_command_error;
305 	}
306 
307 	iser_task->status = ISER_TASK_STATUS_STARTED;
308 
309 	err = iser_post_send(iser_conn->ib_conn, tx_desc);
310 	if (!err)
311 		return 0;
312 
313 send_command_error:
314 	iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
315 	return err;
316 }
317 
318 /**
319  * iser_send_data_out - send data out PDU
320  */
321 int iser_send_data_out(struct iscsi_conn *conn,
322 		       struct iscsi_task *task,
323 		       struct iscsi_data *hdr)
324 {
325 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
326 	struct iscsi_iser_task *iser_task = task->dd_data;
327 	struct iser_tx_desc *tx_desc = NULL;
328 	struct iser_regd_buf *regd_buf;
329 	unsigned long buf_offset;
330 	unsigned long data_seg_len;
331 	uint32_t itt;
332 	int err = 0;
333 	struct ib_sge *tx_dsg;
334 
335 	itt = (__force uint32_t)hdr->itt;
336 	data_seg_len = ntoh24(hdr->dlength);
337 	buf_offset   = ntohl(hdr->offset);
338 
339 	iser_dbg("%s itt %d dseg_len %d offset %d\n",
340 		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
341 
342 	tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
343 	if (tx_desc == NULL) {
344 		iser_err("Failed to alloc desc for post dataout\n");
345 		return -ENOMEM;
346 	}
347 
348 	tx_desc->type = ISCSI_TX_DATAOUT;
349 	tx_desc->iser_header.flags = ISER_VER;
350 	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
351 
352 	/* build the tx desc */
353 	iser_initialize_task_headers(task, tx_desc);
354 
355 	regd_buf = &iser_task->rdma_regd[ISER_DIR_OUT];
356 	tx_dsg = &tx_desc->tx_sg[1];
357 	tx_dsg->addr    = regd_buf->reg.va + buf_offset;
358 	tx_dsg->length  = data_seg_len;
359 	tx_dsg->lkey    = regd_buf->reg.lkey;
360 	tx_desc->num_sge = 2;
361 
362 	if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
363 		iser_err("Offset:%ld & DSL:%ld in Data-Out "
364 			 "inconsistent with total len:%ld, itt:%d\n",
365 			 buf_offset, data_seg_len,
366 			 iser_task->data[ISER_DIR_OUT].data_len, itt);
367 		err = -EINVAL;
368 		goto send_data_out_error;
369 	}
370 	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
371 		 itt, buf_offset, data_seg_len);
372 
373 
374 	err = iser_post_send(iser_conn->ib_conn, tx_desc);
375 	if (!err)
376 		return 0;
377 
378 send_data_out_error:
379 	kmem_cache_free(ig.desc_cache, tx_desc);
380 	iser_err("conn %p failed err %d\n",conn, err);
381 	return err;
382 }
383 
384 int iser_send_control(struct iscsi_conn *conn,
385 		      struct iscsi_task *task)
386 {
387 	struct iscsi_iser_conn *iser_conn = conn->dd_data;
388 	struct iscsi_iser_task *iser_task = task->dd_data;
389 	struct iser_tx_desc *mdesc = &iser_task->desc;
390 	unsigned long data_seg_len;
391 	int err = 0;
392 	struct iser_device *device;
393 	struct iser_conn *ib_conn = iser_conn->ib_conn;
394 
395 	/* build the tx desc regd header and add it to the tx desc dto */
396 	mdesc->type = ISCSI_TX_CONTROL;
397 	iser_create_send_desc(iser_conn->ib_conn, mdesc);
398 
399 	device = iser_conn->ib_conn->device;
400 
401 	data_seg_len = ntoh24(task->hdr->dlength);
402 
403 	if (data_seg_len > 0) {
404 		struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
405 		if (task != conn->login_task) {
406 			iser_err("data present on non login task!!!\n");
407 			goto send_control_error;
408 		}
409 
410 		ib_dma_sync_single_for_cpu(device->ib_device,
411 			ib_conn->login_req_dma, task->data_count,
412 			DMA_TO_DEVICE);
413 
414 		memcpy(iser_conn->ib_conn->login_req_buf, task->data,
415 							task->data_count);
416 
417 		ib_dma_sync_single_for_device(device->ib_device,
418 			ib_conn->login_req_dma, task->data_count,
419 			DMA_TO_DEVICE);
420 
421 		tx_dsg->addr    = iser_conn->ib_conn->login_req_dma;
422 		tx_dsg->length  = task->data_count;
423 		tx_dsg->lkey    = device->mr->lkey;
424 		mdesc->num_sge = 2;
425 	}
426 
427 	if (task == conn->login_task) {
428 		err = iser_post_recvl(iser_conn->ib_conn);
429 		if (err)
430 			goto send_control_error;
431 		err = iser_post_rx_bufs(conn, task->hdr);
432 		if (err)
433 			goto send_control_error;
434 	}
435 
436 	err = iser_post_send(iser_conn->ib_conn, mdesc);
437 	if (!err)
438 		return 0;
439 
440 send_control_error:
441 	iser_err("conn %p failed err %d\n",conn, err);
442 	return err;
443 }
444 
445 /**
446  * iser_rcv_dto_completion - recv DTO completion
447  */
448 void iser_rcv_completion(struct iser_rx_desc *rx_desc,
449 			 unsigned long rx_xfer_len,
450 			 struct iser_conn *ib_conn)
451 {
452 	struct iscsi_iser_conn *conn = ib_conn->iser_conn;
453 	struct iscsi_hdr *hdr;
454 	u64 rx_dma;
455 	int rx_buflen, outstanding, count, err;
456 
457 	/* differentiate between login to all other PDUs */
458 	if ((char *)rx_desc == ib_conn->login_resp_buf) {
459 		rx_dma = ib_conn->login_resp_dma;
460 		rx_buflen = ISER_RX_LOGIN_SIZE;
461 	} else {
462 		rx_dma = rx_desc->dma_addr;
463 		rx_buflen = ISER_RX_PAYLOAD_SIZE;
464 	}
465 
466 	ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
467 			rx_buflen, DMA_FROM_DEVICE);
468 
469 	hdr = &rx_desc->iscsi_header;
470 
471 	iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
472 			hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));
473 
474 	iscsi_iser_recv(conn->iscsi_conn, hdr,
475 		rx_desc->data, rx_xfer_len - ISER_HEADERS_LEN);
476 
477 	ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
478 			rx_buflen, DMA_FROM_DEVICE);
479 
480 	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
481 	 * task eliminates the need to worry on tasks which are completed in   *
482 	 * parallel to the execution of iser_conn_term. So the code that waits *
483 	 * for the posted rx bufs refcount to become zero handles everything   */
484 	conn->ib_conn->post_recv_buf_count--;
485 
486 	if (rx_dma == ib_conn->login_resp_dma)
487 		return;
488 
489 	outstanding = ib_conn->post_recv_buf_count;
490 	if (outstanding + ISER_MIN_POSTED_RX <= ISER_QP_MAX_RECV_DTOS) {
491 		count = min(ISER_QP_MAX_RECV_DTOS - outstanding,
492 						ISER_MIN_POSTED_RX);
493 		err = iser_post_recvm(ib_conn, count);
494 		if (err)
495 			iser_err("posting %d rx bufs err %d\n", count, err);
496 	}
497 }
498 
499 void iser_snd_completion(struct iser_tx_desc *tx_desc,
500 			struct iser_conn *ib_conn)
501 {
502 	struct iscsi_task *task;
503 	struct iser_device *device = ib_conn->device;
504 
505 	if (tx_desc->type == ISCSI_TX_DATAOUT) {
506 		ib_dma_unmap_single(device->ib_device, tx_desc->dma_addr,
507 					ISER_HEADERS_LEN, DMA_TO_DEVICE);
508 		kmem_cache_free(ig.desc_cache, tx_desc);
509 	}
510 
511 	atomic_dec(&ib_conn->post_send_buf_count);
512 
513 	if (tx_desc->type == ISCSI_TX_CONTROL) {
514 		/* this arithmetic is legal by libiscsi dd_data allocation */
515 		task = (void *) ((long)(void *)tx_desc -
516 				  sizeof(struct iscsi_task));
517 		if (task->hdr->itt == RESERVED_ITT)
518 			iscsi_put_task(task);
519 	}
520 }
521 
522 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
523 
524 {
525 	iser_task->status = ISER_TASK_STATUS_INIT;
526 
527 	iser_task->dir[ISER_DIR_IN] = 0;
528 	iser_task->dir[ISER_DIR_OUT] = 0;
529 
530 	iser_task->data[ISER_DIR_IN].data_len  = 0;
531 	iser_task->data[ISER_DIR_OUT].data_len = 0;
532 
533 	memset(&iser_task->rdma_regd[ISER_DIR_IN], 0,
534 	       sizeof(struct iser_regd_buf));
535 	memset(&iser_task->rdma_regd[ISER_DIR_OUT], 0,
536 	       sizeof(struct iser_regd_buf));
537 }
538 
539 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
540 {
541 	int is_rdma_aligned = 1;
542 	struct iser_regd_buf *regd;
543 
544 	/* if we were reading, copy back to unaligned sglist,
545 	 * anyway dma_unmap and free the copy
546 	 */
547 	if (iser_task->data_copy[ISER_DIR_IN].copy_buf != NULL) {
548 		is_rdma_aligned = 0;
549 		iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_IN);
550 	}
551 	if (iser_task->data_copy[ISER_DIR_OUT].copy_buf != NULL) {
552 		is_rdma_aligned = 0;
553 		iser_finalize_rdma_unaligned_sg(iser_task, ISER_DIR_OUT);
554 	}
555 
556 	if (iser_task->dir[ISER_DIR_IN]) {
557 		regd = &iser_task->rdma_regd[ISER_DIR_IN];
558 		if (regd->reg.is_fmr)
559 			iser_unreg_mem(&regd->reg);
560 	}
561 
562 	if (iser_task->dir[ISER_DIR_OUT]) {
563 		regd = &iser_task->rdma_regd[ISER_DIR_OUT];
564 		if (regd->reg.is_fmr)
565 			iser_unreg_mem(&regd->reg);
566 	}
567 
568        /* if the data was unaligned, it was already unmapped and then copied */
569        if (is_rdma_aligned)
570 		iser_dma_unmap_task_data(iser_task);
571 }
572