1 /*******************************************************************************
2  * Filename:  target_core_pscsi.c
3  *
4  * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
5  *
6  * (c) Copyright 2003-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/string.h>
27 #include <linux/parser.h>
28 #include <linux/timer.h>
29 #include <linux/blkdev.h>
30 #include <linux/blk_types.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <linux/genhd.h>
34 #include <linux/cdrom.h>
35 #include <linux/ratelimit.h>
36 #include <linux/module.h>
37 #include <asm/unaligned.h>
38 
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_tcq.h>
42 
43 #include <target/target_core_base.h>
44 #include <target/target_core_backend.h>
45 
46 #include "target_core_alua.h"
47 #include "target_core_internal.h"
48 #include "target_core_pscsi.h"
49 
50 #define ISPRINT(a)  ((a >= ' ') && (a <= '~'))
51 
52 static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
53 {
54 	return container_of(dev, struct pscsi_dev_virt, dev);
55 }
56 
57 static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
58 static void pscsi_req_done(struct request *, blk_status_t);
59 
60 /*	pscsi_attach_hba():
61  *
62  * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
63  *	from the passed SCSI Host ID.
64  */
65 static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
66 {
67 	struct pscsi_hba_virt *phv;
68 
69 	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
70 	if (!phv) {
71 		pr_err("Unable to allocate struct pscsi_hba_virt\n");
72 		return -ENOMEM;
73 	}
74 	phv->phv_host_id = host_id;
75 	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
76 
77 	hba->hba_ptr = phv;
78 
79 	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
80 		" Generic Target Core Stack %s\n", hba->hba_id,
81 		PSCSI_VERSION, TARGET_CORE_VERSION);
82 	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
83 	       hba->hba_id);
84 
85 	return 0;
86 }
87 
88 static void pscsi_detach_hba(struct se_hba *hba)
89 {
90 	struct pscsi_hba_virt *phv = hba->hba_ptr;
91 	struct Scsi_Host *scsi_host = phv->phv_lld_host;
92 
93 	if (scsi_host) {
94 		scsi_host_put(scsi_host);
95 
96 		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
97 			" Generic Target Core\n", hba->hba_id,
98 			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
99 			"Unknown");
100 	} else
101 		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
102 			" from Generic Target Core\n", hba->hba_id);
103 
104 	kfree(phv);
105 	hba->hba_ptr = NULL;
106 }
107 
108 static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
109 {
110 	struct pscsi_hba_virt *phv = hba->hba_ptr;
111 	struct Scsi_Host *sh = phv->phv_lld_host;
112 	/*
113 	 * Release the struct Scsi_Host
114 	 */
115 	if (!mode_flag) {
116 		if (!sh)
117 			return 0;
118 
119 		phv->phv_lld_host = NULL;
120 		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
121 
122 		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
123 			" %s\n", hba->hba_id, (sh->hostt->name) ?
124 			(sh->hostt->name) : "Unknown");
125 
126 		scsi_host_put(sh);
127 		return 0;
128 	}
129 	/*
130 	 * Otherwise, locate struct Scsi_Host from the original passed
131 	 * pSCSI Host ID and enable for phba mode
132 	 */
133 	sh = scsi_host_lookup(phv->phv_host_id);
134 	if (!sh) {
135 		pr_err("pSCSI: Unable to locate SCSI Host for"
136 			" phv_host_id: %d\n", phv->phv_host_id);
137 		return -EINVAL;
138 	}
139 
140 	phv->phv_lld_host = sh;
141 	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
142 
143 	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
144 		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
145 
146 	return 1;
147 }
148 
149 static void pscsi_tape_read_blocksize(struct se_device *dev,
150 		struct scsi_device *sdev)
151 {
152 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
153 	int ret;
154 
155 	buf = kzalloc(12, GFP_KERNEL);
156 	if (!buf)
157 		goto out_free;
158 
159 	memset(cdb, 0, MAX_COMMAND_SIZE);
160 	cdb[0] = MODE_SENSE;
161 	cdb[4] = 0x0c; /* 12 bytes */
162 
163 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf, 12, NULL,
164 			HZ, 1, NULL);
165 	if (ret)
166 		goto out_free;
167 
168 	/*
169 	 * If MODE_SENSE still returns zero, set the default value to 1024.
170 	 */
171 	sdev->sector_size = get_unaligned_be24(&buf[9]);
172 out_free:
173 	if (!sdev->sector_size)
174 		sdev->sector_size = 1024;
175 
176 	kfree(buf);
177 }
178 
179 static void
180 pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
181 {
182 	if (sdev->inquiry_len < INQUIRY_LEN)
183 		return;
184 	/*
185 	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
186 	 */
187 	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
188 	snprintf(wwn->vendor, sizeof(wwn->vendor),
189 		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
190 	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
191 	snprintf(wwn->model, sizeof(wwn->model),
192 		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
193 	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
194 	snprintf(wwn->revision, sizeof(wwn->revision),
195 		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
196 }
197 
198 static int
199 pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
200 {
201 	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
202 	int ret;
203 
204 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
205 	if (!buf)
206 		return -ENOMEM;
207 
208 	memset(cdb, 0, MAX_COMMAND_SIZE);
209 	cdb[0] = INQUIRY;
210 	cdb[1] = 0x01; /* Query VPD */
211 	cdb[2] = 0x80; /* Unit Serial Number */
212 	put_unaligned_be16(INQUIRY_VPD_SERIAL_LEN, &cdb[3]);
213 
214 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
215 			      INQUIRY_VPD_SERIAL_LEN, NULL, HZ, 1, NULL);
216 	if (ret)
217 		goto out_free;
218 
219 	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
220 
221 	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
222 
223 	kfree(buf);
224 	return 0;
225 
226 out_free:
227 	kfree(buf);
228 	return -EPERM;
229 }
230 
231 static void
232 pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
233 		struct t10_wwn *wwn)
234 {
235 	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
236 	int ident_len, page_len, off = 4, ret;
237 	struct t10_vpd *vpd;
238 
239 	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
240 	if (!buf)
241 		return;
242 
243 	memset(cdb, 0, MAX_COMMAND_SIZE);
244 	cdb[0] = INQUIRY;
245 	cdb[1] = 0x01; /* Query VPD */
246 	cdb[2] = 0x83; /* Device Identifier */
247 	put_unaligned_be16(INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, &cdb[3]);
248 
249 	ret = scsi_execute_req(sdev, cdb, DMA_FROM_DEVICE, buf,
250 			      INQUIRY_VPD_DEVICE_IDENTIFIER_LEN,
251 			      NULL, HZ, 1, NULL);
252 	if (ret)
253 		goto out;
254 
255 	page_len = get_unaligned_be16(&buf[2]);
256 	while (page_len > 0) {
257 		/* Grab a pointer to the Identification descriptor */
258 		page_83 = &buf[off];
259 		ident_len = page_83[3];
260 		if (!ident_len) {
261 			pr_err("page_83[3]: identifier"
262 					" length zero!\n");
263 			break;
264 		}
265 		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
266 
267 		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
268 		if (!vpd) {
269 			pr_err("Unable to allocate memory for"
270 					" struct t10_vpd\n");
271 			goto out;
272 		}
273 		INIT_LIST_HEAD(&vpd->vpd_list);
274 
275 		transport_set_vpd_proto_id(vpd, page_83);
276 		transport_set_vpd_assoc(vpd, page_83);
277 
278 		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
279 			off += (ident_len + 4);
280 			page_len -= (ident_len + 4);
281 			kfree(vpd);
282 			continue;
283 		}
284 		if (transport_set_vpd_ident(vpd, page_83) < 0) {
285 			off += (ident_len + 4);
286 			page_len -= (ident_len + 4);
287 			kfree(vpd);
288 			continue;
289 		}
290 
291 		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
292 		off += (ident_len + 4);
293 		page_len -= (ident_len + 4);
294 	}
295 
296 out:
297 	kfree(buf);
298 }
299 
300 static int pscsi_add_device_to_list(struct se_device *dev,
301 		struct scsi_device *sd)
302 {
303 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
304 	struct request_queue *q = sd->request_queue;
305 
306 	pdv->pdv_sd = sd;
307 
308 	if (!sd->queue_depth) {
309 		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
310 
311 		pr_err("Set broken SCSI Device %d:%d:%llu"
312 			" queue_depth to %d\n", sd->channel, sd->id,
313 				sd->lun, sd->queue_depth);
314 	}
315 
316 	dev->dev_attrib.hw_block_size =
317 		min_not_zero((int)sd->sector_size, 512);
318 	dev->dev_attrib.hw_max_sectors =
319 		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
320 	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
321 
322 	/*
323 	 * Setup our standard INQUIRY info into se_dev->t10_wwn
324 	 */
325 	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
326 
327 	/*
328 	 * Locate VPD WWN Information used for various purposes within
329 	 * the Storage Engine.
330 	 */
331 	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
332 		/*
333 		 * If VPD Unit Serial returned GOOD status, try
334 		 * VPD Device Identification page (0x83).
335 		 */
336 		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
337 	}
338 
339 	/*
340 	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
341 	 */
342 	if (sd->type == TYPE_TAPE) {
343 		pscsi_tape_read_blocksize(dev, sd);
344 		dev->dev_attrib.hw_block_size = sd->sector_size;
345 	}
346 	return 0;
347 }
348 
349 static struct se_device *pscsi_alloc_device(struct se_hba *hba,
350 		const char *name)
351 {
352 	struct pscsi_dev_virt *pdv;
353 
354 	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
355 	if (!pdv) {
356 		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
357 		return NULL;
358 	}
359 
360 	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
361 	return &pdv->dev;
362 }
363 
364 /*
365  * Called with struct Scsi_Host->host_lock called.
366  */
367 static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
368 	__releases(sh->host_lock)
369 {
370 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
371 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
372 	struct Scsi_Host *sh = sd->host;
373 	struct block_device *bd;
374 	int ret;
375 
376 	if (scsi_device_get(sd)) {
377 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
378 			sh->host_no, sd->channel, sd->id, sd->lun);
379 		spin_unlock_irq(sh->host_lock);
380 		return -EIO;
381 	}
382 	spin_unlock_irq(sh->host_lock);
383 	/*
384 	 * Claim exclusive struct block_device access to struct scsi_device
385 	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
386 	 */
387 	bd = blkdev_get_by_path(dev->udev_path,
388 				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
389 	if (IS_ERR(bd)) {
390 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
391 		scsi_device_put(sd);
392 		return PTR_ERR(bd);
393 	}
394 	pdv->pdv_bd = bd;
395 
396 	ret = pscsi_add_device_to_list(dev, sd);
397 	if (ret) {
398 		blkdev_put(pdv->pdv_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
399 		scsi_device_put(sd);
400 		return ret;
401 	}
402 
403 	pr_debug("CORE_PSCSI[%d] - Added TYPE_%s for %d:%d:%d:%llu\n",
404 		phv->phv_host_id, sd->type == TYPE_DISK ? "DISK" : "ZBC",
405 		sh->host_no, sd->channel, sd->id, sd->lun);
406 	return 0;
407 }
408 
409 /*
410  * Called with struct Scsi_Host->host_lock called.
411  */
412 static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
413 	__releases(sh->host_lock)
414 {
415 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
416 	struct Scsi_Host *sh = sd->host;
417 	int ret;
418 
419 	if (scsi_device_get(sd)) {
420 		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
421 			sh->host_no, sd->channel, sd->id, sd->lun);
422 		spin_unlock_irq(sh->host_lock);
423 		return -EIO;
424 	}
425 	spin_unlock_irq(sh->host_lock);
426 
427 	ret = pscsi_add_device_to_list(dev, sd);
428 	if (ret) {
429 		scsi_device_put(sd);
430 		return ret;
431 	}
432 	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
433 		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
434 		sd->channel, sd->id, sd->lun);
435 
436 	return 0;
437 }
438 
439 static int pscsi_configure_device(struct se_device *dev)
440 {
441 	struct se_hba *hba = dev->se_hba;
442 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
443 	struct scsi_device *sd;
444 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
445 	struct Scsi_Host *sh = phv->phv_lld_host;
446 	int legacy_mode_enable = 0;
447 	int ret;
448 
449 	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
450 	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
451 	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
452 		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
453 			" scsi_lun_id= parameters\n");
454 		return -EINVAL;
455 	}
456 
457 	/*
458 	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
459 	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
460 	 */
461 	if (!sh) {
462 		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
463 			pr_err("pSCSI: Unable to locate struct"
464 				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
465 			return -ENODEV;
466 		}
467 		/*
468 		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
469 		 * reference, we enforce that udev_path has been set
470 		 */
471 		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
472 			pr_err("pSCSI: udev_path attribute has not"
473 				" been set before ENABLE=1\n");
474 			return -EINVAL;
475 		}
476 		/*
477 		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
478 		 * use the original TCM hba ID to reference Linux/SCSI Host No
479 		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
480 		 */
481 		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
482 			if (hba->dev_count) {
483 				pr_err("pSCSI: Unable to set hba_mode"
484 					" with active devices\n");
485 				return -EEXIST;
486 			}
487 
488 			if (pscsi_pmode_enable_hba(hba, 1) != 1)
489 				return -ENODEV;
490 
491 			legacy_mode_enable = 1;
492 			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
493 			sh = phv->phv_lld_host;
494 		} else {
495 			sh = scsi_host_lookup(pdv->pdv_host_id);
496 			if (!sh) {
497 				pr_err("pSCSI: Unable to locate"
498 					" pdv_host_id: %d\n", pdv->pdv_host_id);
499 				return -EINVAL;
500 			}
501 			pdv->pdv_lld_host = sh;
502 		}
503 	} else {
504 		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
505 			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
506 				" struct Scsi_Host exists\n");
507 			return -EEXIST;
508 		}
509 	}
510 
511 	spin_lock_irq(sh->host_lock);
512 	list_for_each_entry(sd, &sh->__devices, siblings) {
513 		if ((pdv->pdv_channel_id != sd->channel) ||
514 		    (pdv->pdv_target_id != sd->id) ||
515 		    (pdv->pdv_lun_id != sd->lun))
516 			continue;
517 		/*
518 		 * Functions will release the held struct scsi_host->host_lock
519 		 * before calling calling pscsi_add_device_to_list() to register
520 		 * struct scsi_device with target_core_mod.
521 		 */
522 		switch (sd->type) {
523 		case TYPE_DISK:
524 		case TYPE_ZBC:
525 			ret = pscsi_create_type_disk(dev, sd);
526 			break;
527 		default:
528 			ret = pscsi_create_type_nondisk(dev, sd);
529 			break;
530 		}
531 
532 		if (ret) {
533 			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
534 				scsi_host_put(sh);
535 			else if (legacy_mode_enable) {
536 				pscsi_pmode_enable_hba(hba, 0);
537 				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
538 			}
539 			pdv->pdv_sd = NULL;
540 			return ret;
541 		}
542 		return 0;
543 	}
544 	spin_unlock_irq(sh->host_lock);
545 
546 	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
547 		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
548 
549 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
550 		scsi_host_put(sh);
551 	else if (legacy_mode_enable) {
552 		pscsi_pmode_enable_hba(hba, 0);
553 		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
554 	}
555 
556 	return -ENODEV;
557 }
558 
559 static void pscsi_dev_call_rcu(struct rcu_head *p)
560 {
561 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
562 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
563 
564 	kfree(pdv);
565 }
566 
567 static void pscsi_free_device(struct se_device *dev)
568 {
569 	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
570 }
571 
572 static void pscsi_destroy_device(struct se_device *dev)
573 {
574 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
575 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
576 	struct scsi_device *sd = pdv->pdv_sd;
577 
578 	if (sd) {
579 		/*
580 		 * Release exclusive pSCSI internal struct block_device claim for
581 		 * struct scsi_device with TYPE_DISK or TYPE_ZBC
582 		 * from pscsi_create_type_disk()
583 		 */
584 		if ((sd->type == TYPE_DISK || sd->type == TYPE_ZBC) &&
585 		    pdv->pdv_bd) {
586 			blkdev_put(pdv->pdv_bd,
587 				   FMODE_WRITE|FMODE_READ|FMODE_EXCL);
588 			pdv->pdv_bd = NULL;
589 		}
590 		/*
591 		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
592 		 * to struct Scsi_Host now.
593 		 */
594 		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
595 		    (phv->phv_lld_host != NULL))
596 			scsi_host_put(phv->phv_lld_host);
597 		else if (pdv->pdv_lld_host)
598 			scsi_host_put(pdv->pdv_lld_host);
599 
600 		scsi_device_put(sd);
601 
602 		pdv->pdv_sd = NULL;
603 	}
604 }
605 
606 static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
607 			       unsigned char *req_sense)
608 {
609 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
610 	struct scsi_device *sd = pdv->pdv_sd;
611 	struct pscsi_plugin_task *pt = cmd->priv;
612 	unsigned char *cdb;
613 	/*
614 	 * Special case for REPORT_LUNs handling where pscsi_plugin_task has
615 	 * not been allocated because TCM is handling the emulation directly.
616 	 */
617 	if (!pt)
618 		return;
619 
620 	cdb = &pt->pscsi_cdb[0];
621 	/*
622 	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
623 	 * forced.
624 	 */
625 	if (!cmd->data_length)
626 		goto after_mode_sense;
627 
628 	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
629 	    scsi_status == SAM_STAT_GOOD) {
630 		bool read_only = target_lun_is_rdonly(cmd);
631 
632 		if (read_only) {
633 			unsigned char *buf;
634 
635 			buf = transport_kmap_data_sg(cmd);
636 			if (!buf)
637 				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
638 
639 			if (cdb[0] == MODE_SENSE_10) {
640 				if (!(buf[3] & 0x80))
641 					buf[3] |= 0x80;
642 			} else {
643 				if (!(buf[2] & 0x80))
644 					buf[2] |= 0x80;
645 			}
646 
647 			transport_kunmap_data_sg(cmd);
648 		}
649 	}
650 after_mode_sense:
651 
652 	if (sd->type != TYPE_TAPE || !cmd->data_length)
653 		goto after_mode_select;
654 
655 	/*
656 	 * Hack to correctly obtain the initiator requested blocksize for
657 	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
658 	 * struct scsi_device->sector_size will not contain the correct value
659 	 * by default, so we go ahead and set it so
660 	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
661 	 * storage engine.
662 	 */
663 	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
664 	     scsi_status == SAM_STAT_GOOD) {
665 		unsigned char *buf;
666 		u16 bdl;
667 		u32 blocksize;
668 
669 		buf = sg_virt(&cmd->t_data_sg[0]);
670 		if (!buf) {
671 			pr_err("Unable to get buf for scatterlist\n");
672 			goto after_mode_select;
673 		}
674 
675 		if (cdb[0] == MODE_SELECT)
676 			bdl = buf[3];
677 		else
678 			bdl = get_unaligned_be16(&buf[6]);
679 
680 		if (!bdl)
681 			goto after_mode_select;
682 
683 		if (cdb[0] == MODE_SELECT)
684 			blocksize = get_unaligned_be24(&buf[9]);
685 		else
686 			blocksize = get_unaligned_be24(&buf[13]);
687 
688 		sd->sector_size = blocksize;
689 	}
690 after_mode_select:
691 
692 	if (scsi_status == SAM_STAT_CHECK_CONDITION) {
693 		transport_copy_sense_to_cmd(cmd, req_sense);
694 
695 		/*
696 		 * check for TAPE device reads with
697 		 * FM/EOM/ILI set, so that we can get data
698 		 * back despite framework assumption that a
699 		 * check condition means there is no data
700 		 */
701 		if (sd->type == TYPE_TAPE &&
702 		    cmd->data_direction == DMA_FROM_DEVICE) {
703 			/*
704 			 * is sense data valid, fixed format,
705 			 * and have FM, EOM, or ILI set?
706 			 */
707 			if (req_sense[0] == 0xf0 &&	/* valid, fixed format */
708 			    req_sense[2] & 0xe0 &&	/* FM, EOM, or ILI */
709 			    (req_sense[2] & 0xf) == 0) { /* key==NO_SENSE */
710 				pr_debug("Tape FM/EOM/ILI status detected. Treat as normal read.\n");
711 				cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
712 			}
713 		}
714 	}
715 }
716 
717 enum {
718 	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
719 	Opt_scsi_lun_id, Opt_err
720 };
721 
722 static match_table_t tokens = {
723 	{Opt_scsi_host_id, "scsi_host_id=%d"},
724 	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
725 	{Opt_scsi_target_id, "scsi_target_id=%d"},
726 	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
727 	{Opt_err, NULL}
728 };
729 
730 static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
731 		const char *page, ssize_t count)
732 {
733 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
734 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
735 	char *orig, *ptr, *opts;
736 	substring_t args[MAX_OPT_ARGS];
737 	int ret = 0, arg, token;
738 
739 	opts = kstrdup(page, GFP_KERNEL);
740 	if (!opts)
741 		return -ENOMEM;
742 
743 	orig = opts;
744 
745 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
746 		if (!*ptr)
747 			continue;
748 
749 		token = match_token(ptr, tokens, args);
750 		switch (token) {
751 		case Opt_scsi_host_id:
752 			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
753 				pr_err("PSCSI[%d]: Unable to accept"
754 					" scsi_host_id while phv_mode =="
755 					" PHV_LLD_SCSI_HOST_NO\n",
756 					phv->phv_host_id);
757 				ret = -EINVAL;
758 				goto out;
759 			}
760 			ret = match_int(args, &arg);
761 			if (ret)
762 				goto out;
763 			pdv->pdv_host_id = arg;
764 			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
765 				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
766 			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
767 			break;
768 		case Opt_scsi_channel_id:
769 			ret = match_int(args, &arg);
770 			if (ret)
771 				goto out;
772 			pdv->pdv_channel_id = arg;
773 			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
774 				" ID: %d\n",  phv->phv_host_id,
775 				pdv->pdv_channel_id);
776 			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
777 			break;
778 		case Opt_scsi_target_id:
779 			ret = match_int(args, &arg);
780 			if (ret)
781 				goto out;
782 			pdv->pdv_target_id = arg;
783 			pr_debug("PSCSI[%d]: Referencing SCSI Target"
784 				" ID: %d\n", phv->phv_host_id,
785 				pdv->pdv_target_id);
786 			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
787 			break;
788 		case Opt_scsi_lun_id:
789 			ret = match_int(args, &arg);
790 			if (ret)
791 				goto out;
792 			pdv->pdv_lun_id = arg;
793 			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
794 				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
795 			pdv->pdv_flags |= PDF_HAS_LUN_ID;
796 			break;
797 		default:
798 			break;
799 		}
800 	}
801 
802 out:
803 	kfree(orig);
804 	return (!ret) ? count : ret;
805 }
806 
807 static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
808 {
809 	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
810 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
811 	struct scsi_device *sd = pdv->pdv_sd;
812 	unsigned char host_id[16];
813 	ssize_t bl;
814 
815 	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
816 		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
817 	else
818 		snprintf(host_id, 16, "PHBA Mode");
819 
820 	bl = sprintf(b, "SCSI Device Bus Location:"
821 		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
822 		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
823 		host_id);
824 
825 	if (sd) {
826 		bl += sprintf(b + bl, "        Vendor: %."
827 			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
828 		bl += sprintf(b + bl, " Model: %."
829 			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
830 		bl += sprintf(b + bl, " Rev: %."
831 			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
832 	}
833 	return bl;
834 }
835 
836 static void pscsi_bi_endio(struct bio *bio)
837 {
838 	bio_put(bio);
839 }
840 
841 static inline struct bio *pscsi_get_bio(int nr_vecs)
842 {
843 	struct bio *bio;
844 	/*
845 	 * Use bio_malloc() following the comment in for bio -> struct request
846 	 * in block/blk-core.c:blk_make_request()
847 	 */
848 	bio = bio_kmalloc(GFP_KERNEL, nr_vecs);
849 	if (!bio) {
850 		pr_err("PSCSI: bio_kmalloc() failed\n");
851 		return NULL;
852 	}
853 	bio->bi_end_io = pscsi_bi_endio;
854 
855 	return bio;
856 }
857 
858 static sense_reason_t
859 pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
860 		struct request *req)
861 {
862 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
863 	struct bio *bio = NULL;
864 	struct page *page;
865 	struct scatterlist *sg;
866 	u32 data_len = cmd->data_length, i, len, bytes, off;
867 	int nr_pages = (cmd->data_length + sgl[0].offset +
868 			PAGE_SIZE - 1) >> PAGE_SHIFT;
869 	int nr_vecs = 0, rc;
870 	int rw = (cmd->data_direction == DMA_TO_DEVICE);
871 
872 	BUG_ON(!cmd->data_length);
873 
874 	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
875 
876 	for_each_sg(sgl, sg, sgl_nents, i) {
877 		page = sg_page(sg);
878 		off = sg->offset;
879 		len = sg->length;
880 
881 		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
882 			page, len, off);
883 
884 		/*
885 		 * We only have one page of data in each sg element,
886 		 * we can not cross a page boundary.
887 		 */
888 		if (off + len > PAGE_SIZE)
889 			goto fail;
890 
891 		if (len > 0 && data_len > 0) {
892 			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
893 			bytes = min(bytes, data_len);
894 
895 			if (!bio) {
896 new_bio:
897 				nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
898 				nr_pages -= nr_vecs;
899 				/*
900 				 * Calls bio_kmalloc() and sets bio->bi_end_io()
901 				 */
902 				bio = pscsi_get_bio(nr_vecs);
903 				if (!bio)
904 					goto fail;
905 
906 				if (rw)
907 					bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
908 
909 				pr_debug("PSCSI: Allocated bio: %p,"
910 					" dir: %s nr_vecs: %d\n", bio,
911 					(rw) ? "rw" : "r", nr_vecs);
912 			}
913 
914 			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
915 				" bio: %p page: %p len: %d off: %d\n", i, bio,
916 				page, len, off);
917 
918 			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
919 					bio, page, bytes, off);
920 			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
921 				bio_segments(bio), nr_vecs);
922 			if (rc != bytes) {
923 				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
924 					" %d i: %d bio: %p, allocating another"
925 					" bio\n", bio->bi_vcnt, i, bio);
926 
927 				rc = blk_rq_append_bio(req, &bio);
928 				if (rc) {
929 					pr_err("pSCSI: failed to append bio\n");
930 					goto fail;
931 				}
932 
933 				/*
934 				 * Clear the pointer so that another bio will
935 				 * be allocated with pscsi_get_bio() above.
936 				 */
937 				bio = NULL;
938 				goto new_bio;
939 			}
940 
941 			data_len -= bytes;
942 		}
943 	}
944 
945 	if (bio) {
946 		rc = blk_rq_append_bio(req, &bio);
947 		if (rc) {
948 			pr_err("pSCSI: failed to append bio\n");
949 			goto fail;
950 		}
951 	}
952 
953 	return 0;
954 fail:
955 	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
956 }
957 
958 static sense_reason_t
959 pscsi_parse_cdb(struct se_cmd *cmd)
960 {
961 	if (cmd->se_cmd_flags & SCF_BIDI)
962 		return TCM_UNSUPPORTED_SCSI_OPCODE;
963 
964 	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
965 }
966 
967 static sense_reason_t
968 pscsi_execute_cmd(struct se_cmd *cmd)
969 {
970 	struct scatterlist *sgl = cmd->t_data_sg;
971 	u32 sgl_nents = cmd->t_data_nents;
972 	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
973 	struct pscsi_plugin_task *pt;
974 	struct request *req;
975 	sense_reason_t ret;
976 
977 	/*
978 	 * Dynamically alloc cdb space, since it may be larger than
979 	 * TCM_MAX_COMMAND_SIZE
980 	 */
981 	pt = kzalloc(sizeof(*pt) + scsi_command_size(cmd->t_task_cdb), GFP_KERNEL);
982 	if (!pt) {
983 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
984 	}
985 	cmd->priv = pt;
986 
987 	memcpy(pt->pscsi_cdb, cmd->t_task_cdb,
988 		scsi_command_size(cmd->t_task_cdb));
989 
990 	req = blk_get_request(pdv->pdv_sd->request_queue,
991 			cmd->data_direction == DMA_TO_DEVICE ?
992 			REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
993 	if (IS_ERR(req)) {
994 		pr_err("PSCSI: blk_get_request() failed\n");
995 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
996 		goto fail;
997 	}
998 
999 	if (sgl) {
1000 		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
1001 		if (ret)
1002 			goto fail_put_request;
1003 	}
1004 
1005 	req->end_io = pscsi_req_done;
1006 	req->end_io_data = cmd;
1007 	scsi_req(req)->cmd_len = scsi_command_size(pt->pscsi_cdb);
1008 	scsi_req(req)->cmd = &pt->pscsi_cdb[0];
1009 	if (pdv->pdv_sd->type == TYPE_DISK ||
1010 	    pdv->pdv_sd->type == TYPE_ZBC)
1011 		req->timeout = PS_TIMEOUT_DISK;
1012 	else
1013 		req->timeout = PS_TIMEOUT_OTHER;
1014 	scsi_req(req)->retries = PS_RETRY;
1015 
1016 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
1017 			(cmd->sam_task_attr == TCM_HEAD_TAG),
1018 			pscsi_req_done);
1019 
1020 	return 0;
1021 
1022 fail_put_request:
1023 	blk_put_request(req);
1024 fail:
1025 	kfree(pt);
1026 	return ret;
1027 }
1028 
1029 /*	pscsi_get_device_type():
1030  *
1031  *
1032  */
1033 static u32 pscsi_get_device_type(struct se_device *dev)
1034 {
1035 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1036 	struct scsi_device *sd = pdv->pdv_sd;
1037 
1038 	return (sd) ? sd->type : TYPE_NO_LUN;
1039 }
1040 
1041 static sector_t pscsi_get_blocks(struct se_device *dev)
1042 {
1043 	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
1044 
1045 	if (pdv->pdv_bd && pdv->pdv_bd->bd_part)
1046 		return pdv->pdv_bd->bd_part->nr_sects;
1047 
1048 	return 0;
1049 }
1050 
1051 static void pscsi_req_done(struct request *req, blk_status_t status)
1052 {
1053 	struct se_cmd *cmd = req->end_io_data;
1054 	struct pscsi_plugin_task *pt = cmd->priv;
1055 	int result = scsi_req(req)->result;
1056 	u8 scsi_status = status_byte(result) << 1;
1057 
1058 	if (scsi_status) {
1059 		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1060 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1061 			result);
1062 	}
1063 
1064 	pscsi_complete_cmd(cmd, scsi_status, scsi_req(req)->sense);
1065 
1066 	switch (host_byte(result)) {
1067 	case DID_OK:
1068 		target_complete_cmd_with_length(cmd, scsi_status,
1069 			cmd->data_length - scsi_req(req)->resid_len);
1070 		break;
1071 	default:
1072 		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1073 			" 0x%02x Result: 0x%08x\n", cmd, pt->pscsi_cdb[0],
1074 			result);
1075 		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1076 		break;
1077 	}
1078 
1079 	blk_put_request(req);
1080 	kfree(pt);
1081 }
1082 
1083 static const struct target_backend_ops pscsi_ops = {
1084 	.name			= "pscsi",
1085 	.owner			= THIS_MODULE,
1086 	.transport_flags	= TRANSPORT_FLAG_PASSTHROUGH |
1087 				  TRANSPORT_FLAG_PASSTHROUGH_ALUA |
1088 				  TRANSPORT_FLAG_PASSTHROUGH_PGR,
1089 	.attach_hba		= pscsi_attach_hba,
1090 	.detach_hba		= pscsi_detach_hba,
1091 	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1092 	.alloc_device		= pscsi_alloc_device,
1093 	.configure_device	= pscsi_configure_device,
1094 	.destroy_device		= pscsi_destroy_device,
1095 	.free_device		= pscsi_free_device,
1096 	.parse_cdb		= pscsi_parse_cdb,
1097 	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1098 	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1099 	.get_device_type	= pscsi_get_device_type,
1100 	.get_blocks		= pscsi_get_blocks,
1101 	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1102 };
1103 
1104 static int __init pscsi_module_init(void)
1105 {
1106 	return transport_backend_register(&pscsi_ops);
1107 }
1108 
1109 static void __exit pscsi_module_exit(void)
1110 {
1111 	target_backend_unregister(&pscsi_ops);
1112 }
1113 
1114 MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1115 MODULE_AUTHOR("nab@Linux-iSCSI.org");
1116 MODULE_LICENSE("GPL");
1117 
1118 module_init(pscsi_module_init);
1119 module_exit(pscsi_module_exit);
1120