1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*******************************************************************************
   3 * Filename:  target_core_pscsi.c
   4 *
   5 * This file contains the generic target mode <-> Linux SCSI subsystem plugin.
   6 *
   7 * (c) Copyright 2003-2013 Datera, Inc.
   8 *
   9 * Nicholas A. Bellinger <nab@kernel.org>
  10 *
  11 ******************************************************************************/
  12
  13#include <linux/string.h>
  14#include <linux/parser.h>
  15#include <linux/timer.h>
  16#include <linux/blkdev.h>
  17#include <linux/blk_types.h>
  18#include <linux/slab.h>
  19#include <linux/spinlock.h>
  20#include <linux/cdrom.h>
  21#include <linux/ratelimit.h>
  22#include <linux/module.h>
  23#include <linux/unaligned.h>
  24
  25#include <scsi/scsi_device.h>
  26#include <scsi/scsi_host.h>
  27#include <scsi/scsi_tcq.h>
  28
  29#include <target/target_core_base.h>
  30#include <target/target_core_backend.h>
  31
  32#include "target_core_alua.h"
  33#include "target_core_internal.h"
  34#include "target_core_pscsi.h"
  35
  36static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
  37{
  38	return container_of(dev, struct pscsi_dev_virt, dev);
  39}
  40
  41static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
  42static enum rq_end_io_ret pscsi_req_done(struct request *, blk_status_t);
  43
  44/*	pscsi_attach_hba():
  45 *
  46 * 	pscsi_get_sh() used scsi_host_lookup() to locate struct Scsi_Host.
  47 *	from the passed SCSI Host ID.
  48 */
  49static int pscsi_attach_hba(struct se_hba *hba, u32 host_id)
  50{
  51	struct pscsi_hba_virt *phv;
  52
  53	phv = kzalloc(sizeof(struct pscsi_hba_virt), GFP_KERNEL);
  54	if (!phv) {
  55		pr_err("Unable to allocate struct pscsi_hba_virt\n");
  56		return -ENOMEM;
  57	}
  58	phv->phv_host_id = host_id;
  59	phv->phv_mode = PHV_VIRTUAL_HOST_ID;
  60
  61	hba->hba_ptr = phv;
  62
  63	pr_debug("CORE_HBA[%d] - TCM SCSI HBA Driver %s on"
  64		" Generic Target Core Stack %s\n", hba->hba_id,
  65		PSCSI_VERSION, TARGET_CORE_VERSION);
  66	pr_debug("CORE_HBA[%d] - Attached SCSI HBA to Generic\n",
  67	       hba->hba_id);
  68
  69	return 0;
  70}
  71
  72static void pscsi_detach_hba(struct se_hba *hba)
  73{
  74	struct pscsi_hba_virt *phv = hba->hba_ptr;
  75	struct Scsi_Host *scsi_host = phv->phv_lld_host;
  76
  77	if (scsi_host) {
  78		scsi_host_put(scsi_host);
  79
  80		pr_debug("CORE_HBA[%d] - Detached SCSI HBA: %s from"
  81			" Generic Target Core\n", hba->hba_id,
  82			(scsi_host->hostt->name) ? (scsi_host->hostt->name) :
  83			"Unknown");
  84	} else
  85		pr_debug("CORE_HBA[%d] - Detached Virtual SCSI HBA"
  86			" from Generic Target Core\n", hba->hba_id);
  87
  88	kfree(phv);
  89	hba->hba_ptr = NULL;
  90}
  91
  92static int pscsi_pmode_enable_hba(struct se_hba *hba, unsigned long mode_flag)
  93{
  94	struct pscsi_hba_virt *phv = hba->hba_ptr;
  95	struct Scsi_Host *sh = phv->phv_lld_host;
  96	/*
  97	 * Release the struct Scsi_Host
  98	 */
  99	if (!mode_flag) {
 100		if (!sh)
 101			return 0;
 102
 103		phv->phv_lld_host = NULL;
 104		phv->phv_mode = PHV_VIRTUAL_HOST_ID;
 105
 106		pr_debug("CORE_HBA[%d] - Disabled pSCSI HBA Passthrough"
 107			" %s\n", hba->hba_id, (sh->hostt->name) ?
 108			(sh->hostt->name) : "Unknown");
 109
 110		scsi_host_put(sh);
 111		return 0;
 112	}
 113	/*
 114	 * Otherwise, locate struct Scsi_Host from the original passed
 115	 * pSCSI Host ID and enable for phba mode
 116	 */
 117	sh = scsi_host_lookup(phv->phv_host_id);
 118	if (!sh) {
 119		pr_err("pSCSI: Unable to locate SCSI Host for"
 120			" phv_host_id: %d\n", phv->phv_host_id);
 121		return -EINVAL;
 122	}
 123
 124	phv->phv_lld_host = sh;
 125	phv->phv_mode = PHV_LLD_SCSI_HOST_NO;
 126
 127	pr_debug("CORE_HBA[%d] - Enabled pSCSI HBA Passthrough %s\n",
 128		hba->hba_id, (sh->hostt->name) ? (sh->hostt->name) : "Unknown");
 129
 130	return 1;
 131}
 132
 133static void pscsi_tape_read_blocksize(struct se_device *dev,
 134		struct scsi_device *sdev)
 135{
 136	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
 137	int ret;
 138
 139	buf = kzalloc(12, GFP_KERNEL);
 140	if (!buf)
 141		goto out_free;
 142
 143	memset(cdb, 0, MAX_COMMAND_SIZE);
 144	cdb[0] = MODE_SENSE;
 145	cdb[4] = 0x0c; /* 12 bytes */
 146
 147	ret = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, buf, 12, HZ, 1, NULL);
 148	if (ret)
 149		goto out_free;
 150
 151	/*
 152	 * If MODE_SENSE still returns zero, set the default value to 1024.
 153	 */
 154	sdev->sector_size = get_unaligned_be24(&buf[9]);
 155out_free:
 156	if (!sdev->sector_size)
 157		sdev->sector_size = 1024;
 158
 159	kfree(buf);
 160}
 161
 162static void
 163pscsi_set_inquiry_info(struct scsi_device *sdev, struct t10_wwn *wwn)
 164{
 165	if (sdev->inquiry_len < INQUIRY_LEN)
 166		return;
 167	/*
 168	 * Use sdev->inquiry data from drivers/scsi/scsi_scan.c:scsi_add_lun()
 169	 */
 170	BUILD_BUG_ON(sizeof(wwn->vendor) != INQUIRY_VENDOR_LEN + 1);
 171	snprintf(wwn->vendor, sizeof(wwn->vendor),
 172		 "%." __stringify(INQUIRY_VENDOR_LEN) "s", sdev->vendor);
 173	BUILD_BUG_ON(sizeof(wwn->model) != INQUIRY_MODEL_LEN + 1);
 174	snprintf(wwn->model, sizeof(wwn->model),
 175		 "%." __stringify(INQUIRY_MODEL_LEN) "s", sdev->model);
 176	BUILD_BUG_ON(sizeof(wwn->revision) != INQUIRY_REVISION_LEN + 1);
 177	snprintf(wwn->revision, sizeof(wwn->revision),
 178		 "%." __stringify(INQUIRY_REVISION_LEN) "s", sdev->rev);
 179}
 180
 181static int
 182pscsi_get_inquiry_vpd_serial(struct scsi_device *sdev, struct t10_wwn *wwn)
 183{
 184	unsigned char cdb[MAX_COMMAND_SIZE], *buf;
 185	int ret;
 186
 187	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
 188	if (!buf)
 189		return -ENOMEM;
 190
 191	memset(cdb, 0, MAX_COMMAND_SIZE);
 192	cdb[0] = INQUIRY;
 193	cdb[1] = 0x01; /* Query VPD */
 194	cdb[2] = 0x80; /* Unit Serial Number */
 195	put_unaligned_be16(INQUIRY_VPD_SERIAL_LEN, &cdb[3]);
 196
 197	ret = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, buf,
 198			       INQUIRY_VPD_SERIAL_LEN, HZ, 1, NULL);
 199	if (ret)
 200		goto out_free;
 201
 202	snprintf(&wwn->unit_serial[0], INQUIRY_VPD_SERIAL_LEN, "%s", &buf[4]);
 203
 204	wwn->t10_dev->dev_flags |= DF_FIRMWARE_VPD_UNIT_SERIAL;
 205
 206	kfree(buf);
 207	return 0;
 208
 209out_free:
 210	kfree(buf);
 211	return -EPERM;
 212}
 213
 214static void
 215pscsi_get_inquiry_vpd_device_ident(struct scsi_device *sdev,
 216		struct t10_wwn *wwn)
 217{
 218	unsigned char cdb[MAX_COMMAND_SIZE], *buf, *page_83;
 219	int ident_len, page_len, off = 4, ret;
 220	struct t10_vpd *vpd;
 221
 222	buf = kzalloc(INQUIRY_VPD_SERIAL_LEN, GFP_KERNEL);
 223	if (!buf)
 224		return;
 225
 226	memset(cdb, 0, MAX_COMMAND_SIZE);
 227	cdb[0] = INQUIRY;
 228	cdb[1] = 0x01; /* Query VPD */
 229	cdb[2] = 0x83; /* Device Identifier */
 230	put_unaligned_be16(INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, &cdb[3]);
 231
 232	ret = scsi_execute_cmd(sdev, cdb, REQ_OP_DRV_IN, buf,
 233			       INQUIRY_VPD_DEVICE_IDENTIFIER_LEN, HZ, 1, NULL);
 234	if (ret)
 235		goto out;
 236
 237	page_len = get_unaligned_be16(&buf[2]);
 238	while (page_len > 0) {
 239		/* Grab a pointer to the Identification descriptor */
 240		page_83 = &buf[off];
 241		ident_len = page_83[3];
 242		if (!ident_len) {
 243			pr_err("page_83[3]: identifier"
 244					" length zero!\n");
 245			break;
 246		}
 247		pr_debug("T10 VPD Identifier Length: %d\n", ident_len);
 248
 249		vpd = kzalloc(sizeof(struct t10_vpd), GFP_KERNEL);
 250		if (!vpd) {
 251			pr_err("Unable to allocate memory for"
 252					" struct t10_vpd\n");
 253			goto out;
 254		}
 255		INIT_LIST_HEAD(&vpd->vpd_list);
 256
 257		transport_set_vpd_proto_id(vpd, page_83);
 258		transport_set_vpd_assoc(vpd, page_83);
 259
 260		if (transport_set_vpd_ident_type(vpd, page_83) < 0) {
 261			off += (ident_len + 4);
 262			page_len -= (ident_len + 4);
 263			kfree(vpd);
 264			continue;
 265		}
 266		if (transport_set_vpd_ident(vpd, page_83) < 0) {
 267			off += (ident_len + 4);
 268			page_len -= (ident_len + 4);
 269			kfree(vpd);
 270			continue;
 271		}
 272
 273		list_add_tail(&vpd->vpd_list, &wwn->t10_vpd_list);
 274		off += (ident_len + 4);
 275		page_len -= (ident_len + 4);
 276	}
 277
 278out:
 279	kfree(buf);
 280}
 281
 282static int pscsi_add_device_to_list(struct se_device *dev,
 283		struct scsi_device *sd)
 284{
 285	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 286	struct request_queue *q = sd->request_queue;
 287
 288	pdv->pdv_sd = sd;
 289
 290	if (!sd->queue_depth) {
 291		sd->queue_depth = PSCSI_DEFAULT_QUEUEDEPTH;
 292
 293		pr_err("Set broken SCSI Device %d:%d:%llu"
 294			" queue_depth to %d\n", sd->channel, sd->id,
 295				sd->lun, sd->queue_depth);
 296	}
 297
 298	dev->dev_attrib.hw_block_size =
 299		min_not_zero((int)sd->sector_size, 512);
 300	dev->dev_attrib.hw_max_sectors =
 301		min_not_zero(sd->host->max_sectors, queue_max_hw_sectors(q));
 302	dev->dev_attrib.hw_queue_depth = sd->queue_depth;
 303
 304	/*
 305	 * Setup our standard INQUIRY info into se_dev->t10_wwn
 306	 */
 307	pscsi_set_inquiry_info(sd, &dev->t10_wwn);
 308
 309	/*
 310	 * Locate VPD WWN Information used for various purposes within
 311	 * the Storage Engine.
 312	 */
 313	if (!pscsi_get_inquiry_vpd_serial(sd, &dev->t10_wwn)) {
 314		/*
 315		 * If VPD Unit Serial returned GOOD status, try
 316		 * VPD Device Identification page (0x83).
 317		 */
 318		pscsi_get_inquiry_vpd_device_ident(sd, &dev->t10_wwn);
 319	}
 320
 321	/*
 322	 * For TYPE_TAPE, attempt to determine blocksize with MODE_SENSE.
 323	 */
 324	if (sd->type == TYPE_TAPE) {
 325		pscsi_tape_read_blocksize(dev, sd);
 326		dev->dev_attrib.hw_block_size = sd->sector_size;
 327	}
 328	return 0;
 329}
 330
 331static struct se_device *pscsi_alloc_device(struct se_hba *hba,
 332		const char *name)
 333{
 334	struct pscsi_dev_virt *pdv;
 335
 336	pdv = kzalloc(sizeof(struct pscsi_dev_virt), GFP_KERNEL);
 337	if (!pdv) {
 338		pr_err("Unable to allocate memory for struct pscsi_dev_virt\n");
 339		return NULL;
 340	}
 341
 342	pr_debug("PSCSI: Allocated pdv: %p for %s\n", pdv, name);
 343	return &pdv->dev;
 344}
 345
 346/*
 347 * Called with struct Scsi_Host->host_lock called.
 348 */
 349static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
 350	__releases(sh->host_lock)
 351{
 352	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 353	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 354	struct Scsi_Host *sh = sd->host;
 355	struct file *bdev_file;
 356	int ret;
 357
 358	if (scsi_device_get(sd)) {
 359		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
 360			sh->host_no, sd->channel, sd->id, sd->lun);
 361		spin_unlock_irq(sh->host_lock);
 362		return -EIO;
 363	}
 364	spin_unlock_irq(sh->host_lock);
 365	/*
 366	 * Claim exclusive struct block_device access to struct scsi_device
 367	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
 368	 */
 369	bdev_file = bdev_file_open_by_path(dev->udev_path,
 370				BLK_OPEN_WRITE | BLK_OPEN_READ, pdv, NULL);
 371	if (IS_ERR(bdev_file)) {
 372		pr_err("pSCSI: bdev_file_open_by_path() failed\n");
 373		scsi_device_put(sd);
 374		return PTR_ERR(bdev_file);
 375	}
 376	pdv->pdv_bdev_file = bdev_file;
 377
 378	ret = pscsi_add_device_to_list(dev, sd);
 379	if (ret) {
 380		fput(bdev_file);
 381		scsi_device_put(sd);
 382		return ret;
 383	}
 384
 385	pr_debug("CORE_PSCSI[%d] - Added TYPE_%s for %d:%d:%d:%llu\n",
 386		phv->phv_host_id, sd->type == TYPE_DISK ? "DISK" : "ZBC",
 387		sh->host_no, sd->channel, sd->id, sd->lun);
 388	return 0;
 389}
 390
 391/*
 392 * Called with struct Scsi_Host->host_lock called.
 393 */
 394static int pscsi_create_type_nondisk(struct se_device *dev, struct scsi_device *sd)
 395	__releases(sh->host_lock)
 396{
 397	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 398	struct Scsi_Host *sh = sd->host;
 399	int ret;
 400
 401	if (scsi_device_get(sd)) {
 402		pr_err("scsi_device_get() failed for %d:%d:%d:%llu\n",
 403			sh->host_no, sd->channel, sd->id, sd->lun);
 404		spin_unlock_irq(sh->host_lock);
 405		return -EIO;
 406	}
 407	spin_unlock_irq(sh->host_lock);
 408
 409	ret = pscsi_add_device_to_list(dev, sd);
 410	if (ret) {
 411		scsi_device_put(sd);
 412		return ret;
 413	}
 414	pr_debug("CORE_PSCSI[%d] - Added Type: %s for %d:%d:%d:%llu\n",
 415		phv->phv_host_id, scsi_device_type(sd->type), sh->host_no,
 416		sd->channel, sd->id, sd->lun);
 417
 418	return 0;
 419}
 420
 421static int pscsi_configure_device(struct se_device *dev)
 422{
 423	struct se_hba *hba = dev->se_hba;
 424	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 425	struct scsi_device *sd;
 426	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 427	struct Scsi_Host *sh = phv->phv_lld_host;
 428	int legacy_mode_enable = 0;
 429	int ret;
 430
 431	if (!(pdv->pdv_flags & PDF_HAS_CHANNEL_ID) ||
 432	    !(pdv->pdv_flags & PDF_HAS_TARGET_ID) ||
 433	    !(pdv->pdv_flags & PDF_HAS_LUN_ID)) {
 434		pr_err("Missing scsi_channel_id=, scsi_target_id= and"
 435			" scsi_lun_id= parameters\n");
 436		return -EINVAL;
 437	}
 438
 439	/*
 440	 * If not running in PHV_LLD_SCSI_HOST_NO mode, locate the
 441	 * struct Scsi_Host we will need to bring the TCM/pSCSI object online
 442	 */
 443	if (!sh) {
 444		if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
 445			pr_err("pSCSI: Unable to locate struct"
 446				" Scsi_Host for PHV_LLD_SCSI_HOST_NO\n");
 447			return -ENODEV;
 448		}
 449		/*
 450		 * For the newer PHV_VIRTUAL_HOST_ID struct scsi_device
 451		 * reference, we enforce that udev_path has been set
 452		 */
 453		if (!(dev->dev_flags & DF_USING_UDEV_PATH)) {
 454			pr_err("pSCSI: udev_path attribute has not"
 455				" been set before ENABLE=1\n");
 456			return -EINVAL;
 457		}
 458		/*
 459		 * If no scsi_host_id= was passed for PHV_VIRTUAL_HOST_ID,
 460		 * use the original TCM hba ID to reference Linux/SCSI Host No
 461		 * and enable for PHV_LLD_SCSI_HOST_NO mode.
 462		 */
 463		if (!(pdv->pdv_flags & PDF_HAS_VIRT_HOST_ID)) {
 464			if (hba->dev_count) {
 465				pr_err("pSCSI: Unable to set hba_mode"
 466					" with active devices\n");
 467				return -EEXIST;
 468			}
 469
 470			if (pscsi_pmode_enable_hba(hba, 1) != 1)
 471				return -ENODEV;
 472
 473			legacy_mode_enable = 1;
 474			hba->hba_flags |= HBA_FLAGS_PSCSI_MODE;
 475			sh = phv->phv_lld_host;
 476		} else {
 477			sh = scsi_host_lookup(pdv->pdv_host_id);
 478			if (!sh) {
 479				pr_err("pSCSI: Unable to locate"
 480					" pdv_host_id: %d\n", pdv->pdv_host_id);
 481				return -EINVAL;
 482			}
 483			pdv->pdv_lld_host = sh;
 484		}
 485	} else {
 486		if (phv->phv_mode == PHV_VIRTUAL_HOST_ID) {
 487			pr_err("pSCSI: PHV_VIRTUAL_HOST_ID set while"
 488				" struct Scsi_Host exists\n");
 489			return -EEXIST;
 490		}
 491	}
 492
 493	spin_lock_irq(sh->host_lock);
 494	list_for_each_entry(sd, &sh->__devices, siblings) {
 495		if ((pdv->pdv_channel_id != sd->channel) ||
 496		    (pdv->pdv_target_id != sd->id) ||
 497		    (pdv->pdv_lun_id != sd->lun))
 498			continue;
 499		/*
 500		 * Functions will release the held struct scsi_host->host_lock
 501		 * before calling pscsi_add_device_to_list() to register
 502		 * struct scsi_device with target_core_mod.
 503		 */
 504		switch (sd->type) {
 505		case TYPE_DISK:
 506		case TYPE_ZBC:
 507			ret = pscsi_create_type_disk(dev, sd);
 508			break;
 509		default:
 510			ret = pscsi_create_type_nondisk(dev, sd);
 511			break;
 512		}
 513
 514		if (ret) {
 515			if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
 516				scsi_host_put(sh);
 517			else if (legacy_mode_enable) {
 518				pscsi_pmode_enable_hba(hba, 0);
 519				hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
 520			}
 521			pdv->pdv_sd = NULL;
 522			return ret;
 523		}
 524		return 0;
 525	}
 526	spin_unlock_irq(sh->host_lock);
 527
 528	pr_err("pSCSI: Unable to locate %d:%d:%d:%d\n", sh->host_no,
 529		pdv->pdv_channel_id,  pdv->pdv_target_id, pdv->pdv_lun_id);
 530
 531	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
 532		scsi_host_put(sh);
 533	else if (legacy_mode_enable) {
 534		pscsi_pmode_enable_hba(hba, 0);
 535		hba->hba_flags &= ~HBA_FLAGS_PSCSI_MODE;
 536	}
 537
 538	return -ENODEV;
 539}
 540
 541static void pscsi_dev_call_rcu(struct rcu_head *p)
 542{
 543	struct se_device *dev = container_of(p, struct se_device, rcu_head);
 544	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 545
 546	kfree(pdv);
 547}
 548
 549static void pscsi_free_device(struct se_device *dev)
 550{
 551	call_rcu(&dev->rcu_head, pscsi_dev_call_rcu);
 552}
 553
 554static void pscsi_destroy_device(struct se_device *dev)
 555{
 556	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 557	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 558	struct scsi_device *sd = pdv->pdv_sd;
 559
 560	if (sd) {
 561		/*
 562		 * Release exclusive pSCSI internal struct block_device claim for
 563		 * struct scsi_device with TYPE_DISK or TYPE_ZBC
 564		 * from pscsi_create_type_disk()
 565		 */
 566		if ((sd->type == TYPE_DISK || sd->type == TYPE_ZBC) &&
 567		    pdv->pdv_bdev_file) {
 568			fput(pdv->pdv_bdev_file);
 569			pdv->pdv_bdev_file = NULL;
 570		}
 571		/*
 572		 * For HBA mode PHV_LLD_SCSI_HOST_NO, release the reference
 573		 * to struct Scsi_Host now.
 574		 */
 575		if ((phv->phv_mode == PHV_LLD_SCSI_HOST_NO) &&
 576		    (phv->phv_lld_host != NULL))
 577			scsi_host_put(phv->phv_lld_host);
 578		else if (pdv->pdv_lld_host)
 579			scsi_host_put(pdv->pdv_lld_host);
 580
 581		scsi_device_put(sd);
 582
 583		pdv->pdv_sd = NULL;
 584	}
 585}
 586
 587static void pscsi_complete_cmd(struct se_cmd *cmd, u8 scsi_status,
 588			       unsigned char *req_sense, int valid_data)
 589{
 590	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
 591	struct scsi_device *sd = pdv->pdv_sd;
 592	unsigned char *cdb = cmd->priv;
 593
 594	/*
 595	 * Special case for REPORT_LUNs which is emulated and not passed on.
 596	 */
 597	if (!cdb)
 598		return;
 599
 600	/*
 601	 * Hack to make sure that Write-Protect modepage is set if R/O mode is
 602	 * forced.
 603	 */
 604	if (!cmd->data_length)
 605		goto after_mode_sense;
 606
 607	if (((cdb[0] == MODE_SENSE) || (cdb[0] == MODE_SENSE_10)) &&
 608	    scsi_status == SAM_STAT_GOOD) {
 609		bool read_only = target_lun_is_rdonly(cmd);
 610
 611		if (read_only) {
 612			unsigned char *buf;
 613
 614			buf = transport_kmap_data_sg(cmd);
 615			if (!buf) {
 616				; /* XXX: TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE */
 617			} else {
 618				if (cdb[0] == MODE_SENSE_10) {
 619					if (!(buf[3] & 0x80))
 620						buf[3] |= 0x80;
 621				} else {
 622					if (!(buf[2] & 0x80))
 623						buf[2] |= 0x80;
 624				}
 625
 626				transport_kunmap_data_sg(cmd);
 627			}
 628		}
 629	}
 630after_mode_sense:
 631
 632	if (sd->type != TYPE_TAPE || !cmd->data_length)
 633		goto after_mode_select;
 634
 635	/*
 636	 * Hack to correctly obtain the initiator requested blocksize for
 637	 * TYPE_TAPE.  Since this value is dependent upon each tape media,
 638	 * struct scsi_device->sector_size will not contain the correct value
 639	 * by default, so we go ahead and set it so
 640	 * TRANSPORT(dev)->get_blockdev() returns the correct value to the
 641	 * storage engine.
 642	 */
 643	if (((cdb[0] == MODE_SELECT) || (cdb[0] == MODE_SELECT_10)) &&
 644	     scsi_status == SAM_STAT_GOOD) {
 645		unsigned char *buf;
 646		u16 bdl;
 647		u32 blocksize;
 648
 649		buf = sg_virt(&cmd->t_data_sg[0]);
 650		if (!buf) {
 651			pr_err("Unable to get buf for scatterlist\n");
 652			goto after_mode_select;
 653		}
 654
 655		if (cdb[0] == MODE_SELECT)
 656			bdl = buf[3];
 657		else
 658			bdl = get_unaligned_be16(&buf[6]);
 659
 660		if (!bdl)
 661			goto after_mode_select;
 662
 663		if (cdb[0] == MODE_SELECT)
 664			blocksize = get_unaligned_be24(&buf[9]);
 665		else
 666			blocksize = get_unaligned_be24(&buf[13]);
 667
 668		sd->sector_size = blocksize;
 669	}
 670after_mode_select:
 671
 672	if (scsi_status == SAM_STAT_CHECK_CONDITION) {
 673		transport_copy_sense_to_cmd(cmd, req_sense);
 674
 675		/*
 676		 * check for TAPE device reads with
 677		 * FM/EOM/ILI set, so that we can get data
 678		 * back despite framework assumption that a
 679		 * check condition means there is no data
 680		 */
 681		if (sd->type == TYPE_TAPE && valid_data &&
 682		    cmd->data_direction == DMA_FROM_DEVICE) {
 683			/*
 684			 * is sense data valid, fixed format,
 685			 * and have FM, EOM, or ILI set?
 686			 */
 687			if (req_sense[0] == 0xf0 &&	/* valid, fixed format */
 688			    req_sense[2] & 0xe0 &&	/* FM, EOM, or ILI */
 689			    (req_sense[2] & 0xf) == 0) { /* key==NO_SENSE */
 690				pr_debug("Tape FM/EOM/ILI status detected. Treat as normal read.\n");
 691				cmd->se_cmd_flags |= SCF_TREAT_READ_AS_NORMAL;
 692			}
 693		}
 694	}
 695}
 696
 697enum {
 698	Opt_scsi_host_id, Opt_scsi_channel_id, Opt_scsi_target_id,
 699	Opt_scsi_lun_id, Opt_err
 700};
 701
 702static match_table_t tokens = {
 703	{Opt_scsi_host_id, "scsi_host_id=%d"},
 704	{Opt_scsi_channel_id, "scsi_channel_id=%d"},
 705	{Opt_scsi_target_id, "scsi_target_id=%d"},
 706	{Opt_scsi_lun_id, "scsi_lun_id=%d"},
 707	{Opt_err, NULL}
 708};
 709
 710static ssize_t pscsi_set_configfs_dev_params(struct se_device *dev,
 711		const char *page, ssize_t count)
 712{
 713	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 714	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 715	char *orig, *ptr, *opts;
 716	substring_t args[MAX_OPT_ARGS];
 717	int ret = 0, arg, token;
 718
 719	opts = kstrdup(page, GFP_KERNEL);
 720	if (!opts)
 721		return -ENOMEM;
 722
 723	orig = opts;
 724
 725	while ((ptr = strsep(&opts, ",\n")) != NULL) {
 726		if (!*ptr)
 727			continue;
 728
 729		token = match_token(ptr, tokens, args);
 730		switch (token) {
 731		case Opt_scsi_host_id:
 732			if (phv->phv_mode == PHV_LLD_SCSI_HOST_NO) {
 733				pr_err("PSCSI[%d]: Unable to accept"
 734					" scsi_host_id while phv_mode =="
 735					" PHV_LLD_SCSI_HOST_NO\n",
 736					phv->phv_host_id);
 737				ret = -EINVAL;
 738				goto out;
 739			}
 740			ret = match_int(args, &arg);
 741			if (ret)
 742				goto out;
 743			pdv->pdv_host_id = arg;
 744			pr_debug("PSCSI[%d]: Referencing SCSI Host ID:"
 745				" %d\n", phv->phv_host_id, pdv->pdv_host_id);
 746			pdv->pdv_flags |= PDF_HAS_VIRT_HOST_ID;
 747			break;
 748		case Opt_scsi_channel_id:
 749			ret = match_int(args, &arg);
 750			if (ret)
 751				goto out;
 752			pdv->pdv_channel_id = arg;
 753			pr_debug("PSCSI[%d]: Referencing SCSI Channel"
 754				" ID: %d\n",  phv->phv_host_id,
 755				pdv->pdv_channel_id);
 756			pdv->pdv_flags |= PDF_HAS_CHANNEL_ID;
 757			break;
 758		case Opt_scsi_target_id:
 759			ret = match_int(args, &arg);
 760			if (ret)
 761				goto out;
 762			pdv->pdv_target_id = arg;
 763			pr_debug("PSCSI[%d]: Referencing SCSI Target"
 764				" ID: %d\n", phv->phv_host_id,
 765				pdv->pdv_target_id);
 766			pdv->pdv_flags |= PDF_HAS_TARGET_ID;
 767			break;
 768		case Opt_scsi_lun_id:
 769			ret = match_int(args, &arg);
 770			if (ret)
 771				goto out;
 772			pdv->pdv_lun_id = arg;
 773			pr_debug("PSCSI[%d]: Referencing SCSI LUN ID:"
 774				" %d\n", phv->phv_host_id, pdv->pdv_lun_id);
 775			pdv->pdv_flags |= PDF_HAS_LUN_ID;
 776			break;
 777		default:
 778			break;
 779		}
 780	}
 781
 782out:
 783	kfree(orig);
 784	return (!ret) ? count : ret;
 785}
 786
 787static ssize_t pscsi_show_configfs_dev_params(struct se_device *dev, char *b)
 788{
 789	struct pscsi_hba_virt *phv = dev->se_hba->hba_ptr;
 790	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 791	struct scsi_device *sd = pdv->pdv_sd;
 792	unsigned char host_id[16];
 793	ssize_t bl;
 794
 795	if (phv->phv_mode == PHV_VIRTUAL_HOST_ID)
 796		snprintf(host_id, 16, "%d", pdv->pdv_host_id);
 797	else
 798		snprintf(host_id, 16, "PHBA Mode");
 799
 800	bl = sprintf(b, "SCSI Device Bus Location:"
 801		" Channel ID: %d Target ID: %d LUN: %d Host ID: %s\n",
 802		pdv->pdv_channel_id, pdv->pdv_target_id, pdv->pdv_lun_id,
 803		host_id);
 804
 805	if (sd) {
 806		bl += sprintf(b + bl, "        Vendor: %."
 807			__stringify(INQUIRY_VENDOR_LEN) "s", sd->vendor);
 808		bl += sprintf(b + bl, " Model: %."
 809			__stringify(INQUIRY_MODEL_LEN) "s", sd->model);
 810		bl += sprintf(b + bl, " Rev: %."
 811			__stringify(INQUIRY_REVISION_LEN) "s\n", sd->rev);
 812	}
 813	return bl;
 814}
 815
 816static void pscsi_bi_endio(struct bio *bio)
 817{
 818	bio_uninit(bio);
 819	kfree(bio);
 820}
 821
 822static sense_reason_t
 823pscsi_map_sg(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 824		struct request *req)
 825{
 826	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
 827	struct bio *bio = NULL;
 828	struct page *page;
 829	struct scatterlist *sg;
 830	u32 data_len = cmd->data_length, i, len, bytes, off;
 831	int nr_pages = (cmd->data_length + sgl[0].offset +
 832			PAGE_SIZE - 1) >> PAGE_SHIFT;
 833	int nr_vecs = 0, rc;
 834	int rw = (cmd->data_direction == DMA_TO_DEVICE);
 835
 836	BUG_ON(!cmd->data_length);
 837
 838	pr_debug("PSCSI: nr_pages: %d\n", nr_pages);
 839
 840	for_each_sg(sgl, sg, sgl_nents, i) {
 841		page = sg_page(sg);
 842		off = sg->offset;
 843		len = sg->length;
 844
 845		pr_debug("PSCSI: i: %d page: %p len: %d off: %d\n", i,
 846			page, len, off);
 847
 848		/*
 849		 * We only have one page of data in each sg element,
 850		 * we can not cross a page boundary.
 851		 */
 852		if (off + len > PAGE_SIZE)
 853			goto fail;
 854
 855		if (len > 0 && data_len > 0) {
 856			bytes = min_t(unsigned int, len, PAGE_SIZE - off);
 857			bytes = min(bytes, data_len);
 858
 859			if (!bio) {
 860new_bio:
 861				nr_vecs = bio_max_segs(nr_pages);
 862				bio = bio_kmalloc(nr_vecs, GFP_KERNEL);
 863				if (!bio)
 864					goto fail;
 865				bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs,
 866					 rw ? REQ_OP_WRITE : REQ_OP_READ);
 867				bio->bi_end_io = pscsi_bi_endio;
 868
 869				pr_debug("PSCSI: Allocated bio: %p,"
 870					" dir: %s nr_vecs: %d\n", bio,
 871					(rw) ? "rw" : "r", nr_vecs);
 872			}
 873
 874			pr_debug("PSCSI: Calling bio_add_pc_page() i: %d"
 875				" bio: %p page: %p len: %d off: %d\n", i, bio,
 876				page, len, off);
 877
 878			rc = bio_add_pc_page(pdv->pdv_sd->request_queue,
 879					bio, page, bytes, off);
 880			pr_debug("PSCSI: bio->bi_vcnt: %d nr_vecs: %d\n",
 881				bio_segments(bio), nr_vecs);
 882			if (rc != bytes) {
 883				pr_debug("PSCSI: Reached bio->bi_vcnt max:"
 884					" %d i: %d bio: %p, allocating another"
 885					" bio\n", bio->bi_vcnt, i, bio);
 886
 887				rc = blk_rq_append_bio(req, bio);
 888				if (rc) {
 889					pr_err("pSCSI: failed to append bio\n");
 890					goto fail;
 891				}
 892
 893				goto new_bio;
 894			}
 895
 896			data_len -= bytes;
 897		}
 898	}
 899
 900	if (bio) {
 901		rc = blk_rq_append_bio(req, bio);
 902		if (rc) {
 903			pr_err("pSCSI: failed to append bio\n");
 904			goto fail;
 905		}
 906	}
 907
 908	return 0;
 909fail:
 910	if (bio) {
 911		bio_uninit(bio);
 912		kfree(bio);
 913	}
 914	while (req->bio) {
 915		bio = req->bio;
 916		req->bio = bio->bi_next;
 917		bio_uninit(bio);
 918		kfree(bio);
 919	}
 920	req->biotail = NULL;
 921	return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 922}
 923
 924static sense_reason_t
 925pscsi_parse_cdb(struct se_cmd *cmd)
 926{
 927	if (cmd->se_cmd_flags & SCF_BIDI)
 928		return TCM_UNSUPPORTED_SCSI_OPCODE;
 929
 930	return passthrough_parse_cdb(cmd, pscsi_execute_cmd);
 931}
 932
 933static sense_reason_t
 934pscsi_execute_cmd(struct se_cmd *cmd)
 935{
 936	struct scatterlist *sgl = cmd->t_data_sg;
 937	u32 sgl_nents = cmd->t_data_nents;
 938	struct pscsi_dev_virt *pdv = PSCSI_DEV(cmd->se_dev);
 939	struct scsi_cmnd *scmd;
 940	struct request *req;
 941	sense_reason_t ret;
 942
 943	req = scsi_alloc_request(pdv->pdv_sd->request_queue,
 944			cmd->data_direction == DMA_TO_DEVICE ?
 945			REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
 946	if (IS_ERR(req))
 947		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 948
 949	if (sgl) {
 950		ret = pscsi_map_sg(cmd, sgl, sgl_nents, req);
 951		if (ret)
 952			goto fail_put_request;
 953	}
 954
 955	req->end_io = pscsi_req_done;
 956	req->end_io_data = cmd;
 957
 958	scmd = blk_mq_rq_to_pdu(req);
 959	scmd->cmd_len = scsi_command_size(cmd->t_task_cdb);
 960	if (scmd->cmd_len > sizeof(scmd->cmnd)) {
 961		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 962		goto fail_put_request;
 963	}
 964	memcpy(scmd->cmnd, cmd->t_task_cdb, scmd->cmd_len);
 965
 966	if (pdv->pdv_sd->type == TYPE_DISK ||
 967	    pdv->pdv_sd->type == TYPE_ZBC)
 968		req->timeout = PS_TIMEOUT_DISK;
 969	else
 970		req->timeout = PS_TIMEOUT_OTHER;
 971	scmd->allowed = PS_RETRY;
 972
 973	cmd->priv = scmd->cmnd;
 974
 975	blk_execute_rq_nowait(req, cmd->sam_task_attr == TCM_HEAD_TAG);
 976
 977	return 0;
 978
 979fail_put_request:
 980	blk_mq_free_request(req);
 981	return ret;
 982}
 983
 984/*	pscsi_get_device_type():
 985 *
 986 *
 987 */
 988static u32 pscsi_get_device_type(struct se_device *dev)
 989{
 990	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 991	struct scsi_device *sd = pdv->pdv_sd;
 992
 993	return (sd) ? sd->type : TYPE_NO_LUN;
 994}
 995
 996static sector_t pscsi_get_blocks(struct se_device *dev)
 997{
 998	struct pscsi_dev_virt *pdv = PSCSI_DEV(dev);
 999
1000	if (pdv->pdv_bdev_file)
1001		return bdev_nr_sectors(file_bdev(pdv->pdv_bdev_file));
1002	return 0;
1003}
1004
1005static enum rq_end_io_ret pscsi_req_done(struct request *req,
1006					 blk_status_t status)
1007{
1008	struct se_cmd *cmd = req->end_io_data;
1009	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
1010	enum sam_status scsi_status = scmd->result & 0xff;
1011	int valid_data = cmd->data_length - scmd->resid_len;
1012	u8 *cdb = cmd->priv;
1013
1014	if (scsi_status != SAM_STAT_GOOD) {
1015		pr_debug("PSCSI Status Byte exception at cmd: %p CDB:"
1016			" 0x%02x Result: 0x%08x\n", cmd, cdb[0], scmd->result);
1017	}
1018
1019	pscsi_complete_cmd(cmd, scsi_status, scmd->sense_buffer, valid_data);
1020
1021	switch (host_byte(scmd->result)) {
1022	case DID_OK:
1023		target_complete_cmd_with_length(cmd, scsi_status, valid_data);
1024		break;
1025	default:
1026		pr_debug("PSCSI Host Byte exception at cmd: %p CDB:"
1027			" 0x%02x Result: 0x%08x\n", cmd, cdb[0], scmd->result);
1028		target_complete_cmd(cmd, SAM_STAT_CHECK_CONDITION);
1029		break;
1030	}
1031
1032	blk_mq_free_request(req);
1033	return RQ_END_IO_NONE;
1034}
1035
1036static const struct target_backend_ops pscsi_ops = {
1037	.name			= "pscsi",
1038	.owner			= THIS_MODULE,
1039	.transport_flags_default = TRANSPORT_FLAG_PASSTHROUGH |
1040				   TRANSPORT_FLAG_PASSTHROUGH_ALUA |
1041				   TRANSPORT_FLAG_PASSTHROUGH_PGR,
1042	.attach_hba		= pscsi_attach_hba,
1043	.detach_hba		= pscsi_detach_hba,
1044	.pmode_enable_hba	= pscsi_pmode_enable_hba,
1045	.alloc_device		= pscsi_alloc_device,
1046	.configure_device	= pscsi_configure_device,
1047	.destroy_device		= pscsi_destroy_device,
1048	.free_device		= pscsi_free_device,
1049	.parse_cdb		= pscsi_parse_cdb,
1050	.set_configfs_dev_params = pscsi_set_configfs_dev_params,
1051	.show_configfs_dev_params = pscsi_show_configfs_dev_params,
1052	.get_device_type	= pscsi_get_device_type,
1053	.get_blocks		= pscsi_get_blocks,
1054	.tb_dev_attrib_attrs	= passthrough_attrib_attrs,
1055};
1056
1057static int __init pscsi_module_init(void)
1058{
1059	return transport_backend_register(&pscsi_ops);
1060}
1061
1062static void __exit pscsi_module_exit(void)
1063{
1064	target_backend_unregister(&pscsi_ops);
1065}
1066
1067MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
1068MODULE_AUTHOR("nab@Linux-iSCSI.org");
1069MODULE_LICENSE("GPL");
1070
1071module_init(pscsi_module_init);
1072module_exit(pscsi_module_exit);