1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * scsi_scan.c 4 * 5 * Copyright (C) 2000 Eric Youngdale, 6 * Copyright (C) 2002 Patrick Mansfield 7 * 8 * The general scanning/probing algorithm is as follows, exceptions are 9 * made to it depending on device specific flags, compilation options, and 10 * global variable (boot or module load time) settings. 11 * 12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a 13 * device attached, a scsi_device is allocated and setup for it. 14 * 15 * For every id of every channel on the given host: 16 * 17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no 18 * device or storage attached to LUN 0): 19 * 20 * If LUN 0 has a device attached, allocate and setup a 21 * scsi_device for it. 22 * 23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan 24 * all of the LUNs returned by the REPORT LUN; else, 25 * sequentially scan LUNs up until some maximum is reached, 26 * or a LUN is seen that cannot have a device attached to it. 27 */ 28 29 #include <linux/module.h> 30 #include <linux/moduleparam.h> 31 #include <linux/init.h> 32 #include <linux/blkdev.h> 33 #include <linux/delay.h> 34 #include <linux/kthread.h> 35 #include <linux/spinlock.h> 36 #include <linux/async.h> 37 #include <linux/slab.h> 38 #include <asm/unaligned.h> 39 40 #include <scsi/scsi.h> 41 #include <scsi/scsi_cmnd.h> 42 #include <scsi/scsi_device.h> 43 #include <scsi/scsi_driver.h> 44 #include <scsi/scsi_devinfo.h> 45 #include <scsi/scsi_host.h> 46 #include <scsi/scsi_transport.h> 47 #include <scsi/scsi_dh.h> 48 #include <scsi/scsi_eh.h> 49 50 #include "scsi_priv.h" 51 #include "scsi_logging.h" 52 53 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 54 " SCSI scanning, some SCSI devices might not be configured\n" 55 56 /* 57 * Default timeout 58 */ 59 #define SCSI_TIMEOUT (2*HZ) 60 #define SCSI_REPORT_LUNS_TIMEOUT (30*HZ) 61 62 /* 63 * Prefix values for the SCSI id's (stored in sysfs name field) 64 */ 65 #define SCSI_UID_SER_NUM 'S' 66 #define SCSI_UID_UNKNOWN 'Z' 67 68 /* 69 * Return values of some of the scanning functions. 70 * 71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 72 * includes allocation or general failures preventing IO from being sent. 73 * 74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 75 * on the given LUN. 76 * 77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 78 * given LUN. 79 */ 80 #define SCSI_SCAN_NO_RESPONSE 0 81 #define SCSI_SCAN_TARGET_PRESENT 1 82 #define SCSI_SCAN_LUN_PRESENT 2 83 84 static const char *scsi_null_device_strs = "nullnullnullnull"; 85 86 #define MAX_SCSI_LUNS 512 87 88 static u64 max_scsi_luns = MAX_SCSI_LUNS; 89 90 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR); 91 MODULE_PARM_DESC(max_luns, 92 "last scsi LUN (should be between 1 and 2^64-1)"); 93 94 #ifdef CONFIG_SCSI_SCAN_ASYNC 95 #define SCSI_SCAN_TYPE_DEFAULT "async" 96 #else 97 #define SCSI_SCAN_TYPE_DEFAULT "sync" 98 #endif 99 100 char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT; 101 102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), 103 S_IRUGO|S_IWUSR); 104 MODULE_PARM_DESC(scan, "sync, async, manual, or none. " 105 "Setting to 'manual' disables automatic scanning, but allows " 106 "for manual device scan via the 'scan' sysfs attribute."); 107 108 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; 109 110 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR); 111 MODULE_PARM_DESC(inq_timeout, 112 "Timeout (in seconds) waiting for devices to answer INQUIRY." 113 " Default is 20. Some devices may need more; most need less."); 114 115 /* This lock protects only this list */ 116 static DEFINE_SPINLOCK(async_scan_lock); 117 static LIST_HEAD(scanning_hosts); 118 119 struct async_scan_data { 120 struct list_head list; 121 struct Scsi_Host *shost; 122 struct completion prev_finished; 123 }; 124 125 /** 126 * scsi_complete_async_scans - Wait for asynchronous scans to complete 127 * 128 * When this function returns, any host which started scanning before 129 * this function was called will have finished its scan. Hosts which 130 * started scanning after this function was called may or may not have 131 * finished. 132 */ 133 int scsi_complete_async_scans(void) 134 { 135 struct async_scan_data *data; 136 137 do { 138 if (list_empty(&scanning_hosts)) 139 return 0; 140 /* If we can't get memory immediately, that's OK. Just 141 * sleep a little. Even if we never get memory, the async 142 * scans will finish eventually. 143 */ 144 data = kmalloc(sizeof(*data), GFP_KERNEL); 145 if (!data) 146 msleep(1); 147 } while (!data); 148 149 data->shost = NULL; 150 init_completion(&data->prev_finished); 151 152 spin_lock(&async_scan_lock); 153 /* Check that there's still somebody else on the list */ 154 if (list_empty(&scanning_hosts)) 155 goto done; 156 list_add_tail(&data->list, &scanning_hosts); 157 spin_unlock(&async_scan_lock); 158 159 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 160 wait_for_completion(&data->prev_finished); 161 162 spin_lock(&async_scan_lock); 163 list_del(&data->list); 164 if (!list_empty(&scanning_hosts)) { 165 struct async_scan_data *next = list_entry(scanning_hosts.next, 166 struct async_scan_data, list); 167 complete(&next->prev_finished); 168 } 169 done: 170 spin_unlock(&async_scan_lock); 171 172 kfree(data); 173 return 0; 174 } 175 176 /** 177 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 178 * @sdev: scsi device to send command to 179 * @result: area to store the result of the MODE SENSE 180 * 181 * Description: 182 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 183 * Called for BLIST_KEY devices. 184 **/ 185 static void scsi_unlock_floptical(struct scsi_device *sdev, 186 unsigned char *result) 187 { 188 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 189 190 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n"); 191 scsi_cmd[0] = MODE_SENSE; 192 scsi_cmd[1] = 0; 193 scsi_cmd[2] = 0x2e; 194 scsi_cmd[3] = 0; 195 scsi_cmd[4] = 0x2a; /* size */ 196 scsi_cmd[5] = 0; 197 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 198 SCSI_TIMEOUT, 3, NULL); 199 } 200 201 /** 202 * scsi_alloc_sdev - allocate and setup a scsi_Device 203 * @starget: which target to allocate a &scsi_device for 204 * @lun: which lun 205 * @hostdata: usually NULL and set by ->slave_alloc instead 206 * 207 * Description: 208 * Allocate, initialize for io, and return a pointer to a scsi_Device. 209 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 210 * adds scsi_Device to the appropriate list. 211 * 212 * Return value: 213 * scsi_Device pointer, or NULL on failure. 214 **/ 215 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 216 u64 lun, void *hostdata) 217 { 218 unsigned int depth; 219 struct scsi_device *sdev; 220 struct request_queue *q; 221 int display_failure_msg = 1, ret; 222 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 223 224 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 225 GFP_KERNEL); 226 if (!sdev) 227 goto out; 228 229 sdev->vendor = scsi_null_device_strs; 230 sdev->model = scsi_null_device_strs; 231 sdev->rev = scsi_null_device_strs; 232 sdev->host = shost; 233 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 234 sdev->id = starget->id; 235 sdev->lun = lun; 236 sdev->channel = starget->channel; 237 mutex_init(&sdev->state_mutex); 238 sdev->sdev_state = SDEV_CREATED; 239 INIT_LIST_HEAD(&sdev->siblings); 240 INIT_LIST_HEAD(&sdev->same_target_siblings); 241 INIT_LIST_HEAD(&sdev->starved_entry); 242 INIT_LIST_HEAD(&sdev->event_list); 243 spin_lock_init(&sdev->list_lock); 244 mutex_init(&sdev->inquiry_mutex); 245 INIT_WORK(&sdev->event_work, scsi_evt_thread); 246 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 247 248 sdev->sdev_gendev.parent = get_device(&starget->dev); 249 sdev->sdev_target = starget; 250 251 /* usually NULL and set by ->slave_alloc instead */ 252 sdev->hostdata = hostdata; 253 254 /* if the device needs this changing, it may do so in the 255 * slave_configure function */ 256 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 257 258 /* 259 * Some low level driver could use device->type 260 */ 261 sdev->type = -1; 262 263 /* 264 * Assume that the device will have handshaking problems, 265 * and then fix this field later if it turns out it 266 * doesn't 267 */ 268 sdev->borken = 1; 269 270 q = blk_mq_init_queue(&sdev->host->tag_set); 271 if (IS_ERR(q)) { 272 /* release fn is set up in scsi_sysfs_device_initialise, so 273 * have to free and put manually here */ 274 put_device(&starget->dev); 275 kfree(sdev); 276 goto out; 277 } 278 sdev->request_queue = q; 279 q->queuedata = sdev; 280 __scsi_init_queue(sdev->host, q); 281 blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, q); 282 WARN_ON_ONCE(!blk_get_queue(q)); 283 284 depth = sdev->host->cmd_per_lun ?: 1; 285 286 /* 287 * Use .can_queue as budget map's depth because we have to 288 * support adjusting queue depth from sysfs. Meantime use 289 * default device queue depth to figure out sbitmap shift 290 * since we use this queue depth most of times. 291 */ 292 if (sbitmap_init_node(&sdev->budget_map, 293 scsi_device_max_queue_depth(sdev), 294 sbitmap_calculate_shift(depth), 295 GFP_KERNEL, sdev->request_queue->node, 296 false, true)) { 297 put_device(&starget->dev); 298 kfree(sdev); 299 goto out; 300 } 301 302 scsi_change_queue_depth(sdev, depth); 303 304 scsi_sysfs_device_initialize(sdev); 305 306 if (shost->hostt->slave_alloc) { 307 ret = shost->hostt->slave_alloc(sdev); 308 if (ret) { 309 /* 310 * if LLDD reports slave not present, don't clutter 311 * console with alloc failure messages 312 */ 313 if (ret == -ENXIO) 314 display_failure_msg = 0; 315 goto out_device_destroy; 316 } 317 } 318 319 return sdev; 320 321 out_device_destroy: 322 __scsi_remove_device(sdev); 323 out: 324 if (display_failure_msg) 325 printk(ALLOC_FAILURE_MSG, __func__); 326 return NULL; 327 } 328 329 static void scsi_target_destroy(struct scsi_target *starget) 330 { 331 struct device *dev = &starget->dev; 332 struct Scsi_Host *shost = dev_to_shost(dev->parent); 333 unsigned long flags; 334 335 BUG_ON(starget->state == STARGET_DEL); 336 starget->state = STARGET_DEL; 337 transport_destroy_device(dev); 338 spin_lock_irqsave(shost->host_lock, flags); 339 if (shost->hostt->target_destroy) 340 shost->hostt->target_destroy(starget); 341 list_del_init(&starget->siblings); 342 spin_unlock_irqrestore(shost->host_lock, flags); 343 put_device(dev); 344 } 345 346 static void scsi_target_dev_release(struct device *dev) 347 { 348 struct device *parent = dev->parent; 349 struct scsi_target *starget = to_scsi_target(dev); 350 351 kfree(starget); 352 put_device(parent); 353 } 354 355 static struct device_type scsi_target_type = { 356 .name = "scsi_target", 357 .release = scsi_target_dev_release, 358 }; 359 360 int scsi_is_target_device(const struct device *dev) 361 { 362 return dev->type == &scsi_target_type; 363 } 364 EXPORT_SYMBOL(scsi_is_target_device); 365 366 static struct scsi_target *__scsi_find_target(struct device *parent, 367 int channel, uint id) 368 { 369 struct scsi_target *starget, *found_starget = NULL; 370 struct Scsi_Host *shost = dev_to_shost(parent); 371 /* 372 * Search for an existing target for this sdev. 373 */ 374 list_for_each_entry(starget, &shost->__targets, siblings) { 375 if (starget->id == id && 376 starget->channel == channel) { 377 found_starget = starget; 378 break; 379 } 380 } 381 if (found_starget) 382 get_device(&found_starget->dev); 383 384 return found_starget; 385 } 386 387 /** 388 * scsi_target_reap_ref_release - remove target from visibility 389 * @kref: the reap_ref in the target being released 390 * 391 * Called on last put of reap_ref, which is the indication that no device 392 * under this target is visible anymore, so render the target invisible in 393 * sysfs. Note: we have to be in user context here because the target reaps 394 * should be done in places where the scsi device visibility is being removed. 395 */ 396 static void scsi_target_reap_ref_release(struct kref *kref) 397 { 398 struct scsi_target *starget 399 = container_of(kref, struct scsi_target, reap_ref); 400 401 /* 402 * if we get here and the target is still in a CREATED state that 403 * means it was allocated but never made visible (because a scan 404 * turned up no LUNs), so don't call device_del() on it. 405 */ 406 if ((starget->state != STARGET_CREATED) && 407 (starget->state != STARGET_CREATED_REMOVE)) { 408 transport_remove_device(&starget->dev); 409 device_del(&starget->dev); 410 } 411 scsi_target_destroy(starget); 412 } 413 414 static void scsi_target_reap_ref_put(struct scsi_target *starget) 415 { 416 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 417 } 418 419 /** 420 * scsi_alloc_target - allocate a new or find an existing target 421 * @parent: parent of the target (need not be a scsi host) 422 * @channel: target channel number (zero if no channels) 423 * @id: target id number 424 * 425 * Return an existing target if one exists, provided it hasn't already 426 * gone into STARGET_DEL state, otherwise allocate a new target. 427 * 428 * The target is returned with an incremented reference, so the caller 429 * is responsible for both reaping and doing a last put 430 */ 431 static struct scsi_target *scsi_alloc_target(struct device *parent, 432 int channel, uint id) 433 { 434 struct Scsi_Host *shost = dev_to_shost(parent); 435 struct device *dev = NULL; 436 unsigned long flags; 437 const int size = sizeof(struct scsi_target) 438 + shost->transportt->target_size; 439 struct scsi_target *starget; 440 struct scsi_target *found_target; 441 int error, ref_got; 442 443 starget = kzalloc(size, GFP_KERNEL); 444 if (!starget) { 445 printk(KERN_ERR "%s: allocation failure\n", __func__); 446 return NULL; 447 } 448 dev = &starget->dev; 449 device_initialize(dev); 450 kref_init(&starget->reap_ref); 451 dev->parent = get_device(parent); 452 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 453 dev->bus = &scsi_bus_type; 454 dev->type = &scsi_target_type; 455 starget->id = id; 456 starget->channel = channel; 457 starget->can_queue = 0; 458 INIT_LIST_HEAD(&starget->siblings); 459 INIT_LIST_HEAD(&starget->devices); 460 starget->state = STARGET_CREATED; 461 starget->scsi_level = SCSI_2; 462 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 463 retry: 464 spin_lock_irqsave(shost->host_lock, flags); 465 466 found_target = __scsi_find_target(parent, channel, id); 467 if (found_target) 468 goto found; 469 470 list_add_tail(&starget->siblings, &shost->__targets); 471 spin_unlock_irqrestore(shost->host_lock, flags); 472 /* allocate and add */ 473 transport_setup_device(dev); 474 if (shost->hostt->target_alloc) { 475 error = shost->hostt->target_alloc(starget); 476 477 if(error) { 478 if (error != -ENXIO) 479 dev_err(dev, "target allocation failed, error %d\n", error); 480 /* don't want scsi_target_reap to do the final 481 * put because it will be under the host lock */ 482 scsi_target_destroy(starget); 483 return NULL; 484 } 485 } 486 get_device(dev); 487 488 return starget; 489 490 found: 491 /* 492 * release routine already fired if kref is zero, so if we can still 493 * take the reference, the target must be alive. If we can't, it must 494 * be dying and we need to wait for a new target 495 */ 496 ref_got = kref_get_unless_zero(&found_target->reap_ref); 497 498 spin_unlock_irqrestore(shost->host_lock, flags); 499 if (ref_got) { 500 put_device(dev); 501 return found_target; 502 } 503 /* 504 * Unfortunately, we found a dying target; need to wait until it's 505 * dead before we can get a new one. There is an anomaly here. We 506 * *should* call scsi_target_reap() to balance the kref_get() of the 507 * reap_ref above. However, since the target being released, it's 508 * already invisible and the reap_ref is irrelevant. If we call 509 * scsi_target_reap() we might spuriously do another device_del() on 510 * an already invisible target. 511 */ 512 put_device(&found_target->dev); 513 /* 514 * length of time is irrelevant here, we just want to yield the CPU 515 * for a tick to avoid busy waiting for the target to die. 516 */ 517 msleep(1); 518 goto retry; 519 } 520 521 /** 522 * scsi_target_reap - check to see if target is in use and destroy if not 523 * @starget: target to be checked 524 * 525 * This is used after removing a LUN or doing a last put of the target 526 * it checks atomically that nothing is using the target and removes 527 * it if so. 528 */ 529 void scsi_target_reap(struct scsi_target *starget) 530 { 531 /* 532 * serious problem if this triggers: STARGET_DEL is only set in the if 533 * the reap_ref drops to zero, so we're trying to do another final put 534 * on an already released kref 535 */ 536 BUG_ON(starget->state == STARGET_DEL); 537 scsi_target_reap_ref_put(starget); 538 } 539 540 /** 541 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 542 * INQUIRY result string 543 * @s: INQUIRY result string to sanitize 544 * @len: length of the string 545 * 546 * Description: 547 * The SCSI spec says that INQUIRY vendor, product, and revision 548 * strings must consist entirely of graphic ASCII characters, 549 * padded on the right with spaces. Since not all devices obey 550 * this rule, we will replace non-graphic or non-ASCII characters 551 * with spaces. Exception: a NUL character is interpreted as a 552 * string terminator, so all the following characters are set to 553 * spaces. 554 **/ 555 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 556 { 557 int terminated = 0; 558 559 for (; len > 0; (--len, ++s)) { 560 if (*s == 0) 561 terminated = 1; 562 if (terminated || *s < 0x20 || *s > 0x7e) 563 *s = ' '; 564 } 565 } 566 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 567 568 /** 569 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 570 * @sdev: scsi_device to probe 571 * @inq_result: area to store the INQUIRY result 572 * @result_len: len of inq_result 573 * @bflags: store any bflags found here 574 * 575 * Description: 576 * Probe the lun associated with @req using a standard SCSI INQUIRY; 577 * 578 * If the INQUIRY is successful, zero is returned and the 579 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 580 * are copied to the scsi_device any flags value is stored in *@bflags. 581 **/ 582 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 583 int result_len, blist_flags_t *bflags) 584 { 585 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 586 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 587 int response_len = 0; 588 int pass, count, result; 589 struct scsi_sense_hdr sshdr; 590 591 *bflags = 0; 592 593 /* Perform up to 3 passes. The first pass uses a conservative 594 * transfer length of 36 unless sdev->inquiry_len specifies a 595 * different value. */ 596 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 597 try_inquiry_len = first_inquiry_len; 598 pass = 1; 599 600 next_pass: 601 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 602 "scsi scan: INQUIRY pass %d length %d\n", 603 pass, try_inquiry_len)); 604 605 /* Each pass gets up to three chances to ignore Unit Attention */ 606 for (count = 0; count < 3; ++count) { 607 int resid; 608 609 memset(scsi_cmd, 0, 6); 610 scsi_cmd[0] = INQUIRY; 611 scsi_cmd[4] = (unsigned char) try_inquiry_len; 612 613 memset(inq_result, 0, try_inquiry_len); 614 615 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 616 inq_result, try_inquiry_len, &sshdr, 617 HZ / 2 + HZ * scsi_inq_timeout, 3, 618 &resid); 619 620 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 621 "scsi scan: INQUIRY %s with code 0x%x\n", 622 result ? "failed" : "successful", result)); 623 624 if (result > 0) { 625 /* 626 * not-ready to ready transition [asc/ascq=0x28/0x0] 627 * or power-on, reset [asc/ascq=0x29/0x0], continue. 628 * INQUIRY should not yield UNIT_ATTENTION 629 * but many buggy devices do so anyway. 630 */ 631 if (scsi_status_is_check_condition(result) && 632 scsi_sense_valid(&sshdr)) { 633 if ((sshdr.sense_key == UNIT_ATTENTION) && 634 ((sshdr.asc == 0x28) || 635 (sshdr.asc == 0x29)) && 636 (sshdr.ascq == 0)) 637 continue; 638 } 639 } else if (result == 0) { 640 /* 641 * if nothing was transferred, we try 642 * again. It's a workaround for some USB 643 * devices. 644 */ 645 if (resid == try_inquiry_len) 646 continue; 647 } 648 break; 649 } 650 651 if (result == 0) { 652 scsi_sanitize_inquiry_string(&inq_result[8], 8); 653 scsi_sanitize_inquiry_string(&inq_result[16], 16); 654 scsi_sanitize_inquiry_string(&inq_result[32], 4); 655 656 response_len = inq_result[4] + 5; 657 if (response_len > 255) 658 response_len = first_inquiry_len; /* sanity */ 659 660 /* 661 * Get any flags for this device. 662 * 663 * XXX add a bflags to scsi_device, and replace the 664 * corresponding bit fields in scsi_device, so bflags 665 * need not be passed as an argument. 666 */ 667 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 668 &inq_result[16]); 669 670 /* When the first pass succeeds we gain information about 671 * what larger transfer lengths might work. */ 672 if (pass == 1) { 673 if (BLIST_INQUIRY_36 & *bflags) 674 next_inquiry_len = 36; 675 else if (sdev->inquiry_len) 676 next_inquiry_len = sdev->inquiry_len; 677 else 678 next_inquiry_len = response_len; 679 680 /* If more data is available perform the second pass */ 681 if (next_inquiry_len > try_inquiry_len) { 682 try_inquiry_len = next_inquiry_len; 683 pass = 2; 684 goto next_pass; 685 } 686 } 687 688 } else if (pass == 2) { 689 sdev_printk(KERN_INFO, sdev, 690 "scsi scan: %d byte inquiry failed. " 691 "Consider BLIST_INQUIRY_36 for this device\n", 692 try_inquiry_len); 693 694 /* If this pass failed, the third pass goes back and transfers 695 * the same amount as we successfully got in the first pass. */ 696 try_inquiry_len = first_inquiry_len; 697 pass = 3; 698 goto next_pass; 699 } 700 701 /* If the last transfer attempt got an error, assume the 702 * peripheral doesn't exist or is dead. */ 703 if (result) 704 return -EIO; 705 706 /* Don't report any more data than the device says is valid */ 707 sdev->inquiry_len = min(try_inquiry_len, response_len); 708 709 /* 710 * XXX Abort if the response length is less than 36? If less than 711 * 32, the lookup of the device flags (above) could be invalid, 712 * and it would be possible to take an incorrect action - we do 713 * not want to hang because of a short INQUIRY. On the flip side, 714 * if the device is spun down or becoming ready (and so it gives a 715 * short INQUIRY), an abort here prevents any further use of the 716 * device, including spin up. 717 * 718 * On the whole, the best approach seems to be to assume the first 719 * 36 bytes are valid no matter what the device says. That's 720 * better than copying < 36 bytes to the inquiry-result buffer 721 * and displaying garbage for the Vendor, Product, or Revision 722 * strings. 723 */ 724 if (sdev->inquiry_len < 36) { 725 if (!sdev->host->short_inquiry) { 726 shost_printk(KERN_INFO, sdev->host, 727 "scsi scan: INQUIRY result too short (%d)," 728 " using 36\n", sdev->inquiry_len); 729 sdev->host->short_inquiry = 1; 730 } 731 sdev->inquiry_len = 36; 732 } 733 734 /* 735 * Related to the above issue: 736 * 737 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 738 * and if not ready, sent a START_STOP to start (maybe spin up) and 739 * then send the INQUIRY again, since the INQUIRY can change after 740 * a device is initialized. 741 * 742 * Ideally, start a device if explicitly asked to do so. This 743 * assumes that a device is spun up on power on, spun down on 744 * request, and then spun up on request. 745 */ 746 747 /* 748 * The scanning code needs to know the scsi_level, even if no 749 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 750 * non-zero LUNs can be scanned. 751 */ 752 sdev->scsi_level = inq_result[2] & 0x07; 753 if (sdev->scsi_level >= 2 || 754 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 755 sdev->scsi_level++; 756 sdev->sdev_target->scsi_level = sdev->scsi_level; 757 758 /* 759 * If SCSI-2 or lower, and if the transport requires it, 760 * store the LUN value in CDB[1]. 761 */ 762 sdev->lun_in_cdb = 0; 763 if (sdev->scsi_level <= SCSI_2 && 764 sdev->scsi_level != SCSI_UNKNOWN && 765 !sdev->host->no_scsi2_lun_in_cdb) 766 sdev->lun_in_cdb = 1; 767 768 return 0; 769 } 770 771 /** 772 * scsi_add_lun - allocate and fully initialze a scsi_device 773 * @sdev: holds information to be stored in the new scsi_device 774 * @inq_result: holds the result of a previous INQUIRY to the LUN 775 * @bflags: black/white list flag 776 * @async: 1 if this device is being scanned asynchronously 777 * 778 * Description: 779 * Initialize the scsi_device @sdev. Optionally set fields based 780 * on values in *@bflags. 781 * 782 * Return: 783 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 784 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 785 **/ 786 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 787 blist_flags_t *bflags, int async) 788 { 789 int ret; 790 791 /* 792 * XXX do not save the inquiry, since it can change underneath us, 793 * save just vendor/model/rev. 794 * 795 * Rather than save it and have an ioctl that retrieves the saved 796 * value, have an ioctl that executes the same INQUIRY code used 797 * in scsi_probe_lun, let user level programs doing INQUIRY 798 * scanning run at their own risk, or supply a user level program 799 * that can correctly scan. 800 */ 801 802 /* 803 * Copy at least 36 bytes of INQUIRY data, so that we don't 804 * dereference unallocated memory when accessing the Vendor, 805 * Product, and Revision strings. Badly behaved devices may set 806 * the INQUIRY Additional Length byte to a small value, indicating 807 * these strings are invalid, but often they contain plausible data 808 * nonetheless. It doesn't matter if the device sent < 36 bytes 809 * total, since scsi_probe_lun() initializes inq_result with 0s. 810 */ 811 sdev->inquiry = kmemdup(inq_result, 812 max_t(size_t, sdev->inquiry_len, 36), 813 GFP_KERNEL); 814 if (sdev->inquiry == NULL) 815 return SCSI_SCAN_NO_RESPONSE; 816 817 sdev->vendor = (char *) (sdev->inquiry + 8); 818 sdev->model = (char *) (sdev->inquiry + 16); 819 sdev->rev = (char *) (sdev->inquiry + 32); 820 821 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 822 /* 823 * sata emulation layer device. This is a hack to work around 824 * the SATL power management specifications which state that 825 * when the SATL detects the device has gone into standby 826 * mode, it shall respond with NOT READY. 827 */ 828 sdev->allow_restart = 1; 829 } 830 831 if (*bflags & BLIST_ISROM) { 832 sdev->type = TYPE_ROM; 833 sdev->removable = 1; 834 } else { 835 sdev->type = (inq_result[0] & 0x1f); 836 sdev->removable = (inq_result[1] & 0x80) >> 7; 837 838 /* 839 * some devices may respond with wrong type for 840 * well-known logical units. Force well-known type 841 * to enumerate them correctly. 842 */ 843 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 844 sdev_printk(KERN_WARNING, sdev, 845 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 846 __func__, sdev->type, (unsigned int)sdev->lun); 847 sdev->type = TYPE_WLUN; 848 } 849 850 } 851 852 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 853 /* RBC and MMC devices can return SCSI-3 compliance and yet 854 * still not support REPORT LUNS, so make them act as 855 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 856 * specifically set */ 857 if ((*bflags & BLIST_REPORTLUN2) == 0) 858 *bflags |= BLIST_NOREPORTLUN; 859 } 860 861 /* 862 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 863 * spec says: The device server is capable of supporting the 864 * specified peripheral device type on this logical unit. However, 865 * the physical device is not currently connected to this logical 866 * unit. 867 * 868 * The above is vague, as it implies that we could treat 001 and 869 * 011 the same. Stay compatible with previous code, and create a 870 * scsi_device for a PQ of 1 871 * 872 * Don't set the device offline here; rather let the upper 873 * level drivers eval the PQ to decide whether they should 874 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 875 */ 876 877 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 878 sdev->lockable = sdev->removable; 879 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 880 881 if (sdev->scsi_level >= SCSI_3 || 882 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 883 sdev->ppr = 1; 884 if (inq_result[7] & 0x60) 885 sdev->wdtr = 1; 886 if (inq_result[7] & 0x10) 887 sdev->sdtr = 1; 888 889 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 890 "ANSI: %d%s\n", scsi_device_type(sdev->type), 891 sdev->vendor, sdev->model, sdev->rev, 892 sdev->inq_periph_qual, inq_result[2] & 0x07, 893 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 894 895 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 896 !(*bflags & BLIST_NOTQ)) { 897 sdev->tagged_supported = 1; 898 sdev->simple_tags = 1; 899 } 900 901 /* 902 * Some devices (Texel CD ROM drives) have handshaking problems 903 * when used with the Seagate controllers. borken is initialized 904 * to 1, and then set it to 0 here. 905 */ 906 if ((*bflags & BLIST_BORKEN) == 0) 907 sdev->borken = 0; 908 909 if (*bflags & BLIST_NO_ULD_ATTACH) 910 sdev->no_uld_attach = 1; 911 912 /* 913 * Apparently some really broken devices (contrary to the SCSI 914 * standards) need to be selected without asserting ATN 915 */ 916 if (*bflags & BLIST_SELECT_NO_ATN) 917 sdev->select_no_atn = 1; 918 919 /* 920 * Maximum 512 sector transfer length 921 * broken RA4x00 Compaq Disk Array 922 */ 923 if (*bflags & BLIST_MAX_512) 924 blk_queue_max_hw_sectors(sdev->request_queue, 512); 925 /* 926 * Max 1024 sector transfer length for targets that report incorrect 927 * max/optimal lengths and relied on the old block layer safe default 928 */ 929 else if (*bflags & BLIST_MAX_1024) 930 blk_queue_max_hw_sectors(sdev->request_queue, 1024); 931 932 /* 933 * Some devices may not want to have a start command automatically 934 * issued when a device is added. 935 */ 936 if (*bflags & BLIST_NOSTARTONADD) 937 sdev->no_start_on_add = 1; 938 939 if (*bflags & BLIST_SINGLELUN) 940 scsi_target(sdev)->single_lun = 1; 941 942 sdev->use_10_for_rw = 1; 943 944 /* some devices don't like REPORT SUPPORTED OPERATION CODES 945 * and will simply timeout causing sd_mod init to take a very 946 * very long time */ 947 if (*bflags & BLIST_NO_RSOC) 948 sdev->no_report_opcodes = 1; 949 950 /* set the device running here so that slave configure 951 * may do I/O */ 952 mutex_lock(&sdev->state_mutex); 953 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 954 if (ret) 955 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 956 mutex_unlock(&sdev->state_mutex); 957 958 if (ret) { 959 sdev_printk(KERN_ERR, sdev, 960 "in wrong state %s to complete scan\n", 961 scsi_device_state_name(sdev->sdev_state)); 962 return SCSI_SCAN_NO_RESPONSE; 963 } 964 965 if (*bflags & BLIST_NOT_LOCKABLE) 966 sdev->lockable = 0; 967 968 if (*bflags & BLIST_RETRY_HWERROR) 969 sdev->retry_hwerror = 1; 970 971 if (*bflags & BLIST_NO_DIF) 972 sdev->no_dif = 1; 973 974 if (*bflags & BLIST_UNMAP_LIMIT_WS) 975 sdev->unmap_limit_for_ws = 1; 976 977 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 978 979 if (*bflags & BLIST_TRY_VPD_PAGES) 980 sdev->try_vpd_pages = 1; 981 else if (*bflags & BLIST_SKIP_VPD_PAGES) 982 sdev->skip_vpd_pages = 1; 983 984 transport_configure_device(&sdev->sdev_gendev); 985 986 if (sdev->host->hostt->slave_configure) { 987 ret = sdev->host->hostt->slave_configure(sdev); 988 if (ret) { 989 /* 990 * if LLDD reports slave not present, don't clutter 991 * console with alloc failure messages 992 */ 993 if (ret != -ENXIO) { 994 sdev_printk(KERN_ERR, sdev, 995 "failed to configure device\n"); 996 } 997 return SCSI_SCAN_NO_RESPONSE; 998 } 999 } 1000 1001 if (sdev->scsi_level >= SCSI_3) 1002 scsi_attach_vpd(sdev); 1003 1004 sdev->max_queue_depth = sdev->queue_depth; 1005 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); 1006 sdev->sdev_bflags = *bflags; 1007 1008 /* 1009 * Ok, the device is now all set up, we can 1010 * register it and tell the rest of the kernel 1011 * about it. 1012 */ 1013 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 1014 return SCSI_SCAN_NO_RESPONSE; 1015 1016 return SCSI_SCAN_LUN_PRESENT; 1017 } 1018 1019 #ifdef CONFIG_SCSI_LOGGING 1020 /** 1021 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1022 * @buf: Output buffer with at least end-first+1 bytes of space 1023 * @inq: Inquiry buffer (input) 1024 * @first: Offset of string into inq 1025 * @end: Index after last character in inq 1026 */ 1027 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1028 unsigned first, unsigned end) 1029 { 1030 unsigned term = 0, idx; 1031 1032 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1033 if (inq[idx+first] > ' ') { 1034 buf[idx] = inq[idx+first]; 1035 term = idx+1; 1036 } else { 1037 buf[idx] = ' '; 1038 } 1039 } 1040 buf[term] = 0; 1041 return buf; 1042 } 1043 #endif 1044 1045 /** 1046 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1047 * @starget: pointer to target device structure 1048 * @lun: LUN of target device 1049 * @bflagsp: store bflags here if not NULL 1050 * @sdevp: probe the LUN corresponding to this scsi_device 1051 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1052 * needed on first scan 1053 * @hostdata: passed to scsi_alloc_sdev() 1054 * 1055 * Description: 1056 * Call scsi_probe_lun, if a LUN with an attached device is found, 1057 * allocate and set it up by calling scsi_add_lun. 1058 * 1059 * Return: 1060 * 1061 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1062 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1063 * attached at the LUN 1064 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1065 **/ 1066 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1067 u64 lun, blist_flags_t *bflagsp, 1068 struct scsi_device **sdevp, 1069 enum scsi_scan_mode rescan, 1070 void *hostdata) 1071 { 1072 struct scsi_device *sdev; 1073 unsigned char *result; 1074 blist_flags_t bflags; 1075 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1076 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1077 1078 /* 1079 * The rescan flag is used as an optimization, the first scan of a 1080 * host adapter calls into here with rescan == 0. 1081 */ 1082 sdev = scsi_device_lookup_by_target(starget, lun); 1083 if (sdev) { 1084 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1085 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1086 "scsi scan: device exists on %s\n", 1087 dev_name(&sdev->sdev_gendev))); 1088 if (sdevp) 1089 *sdevp = sdev; 1090 else 1091 scsi_device_put(sdev); 1092 1093 if (bflagsp) 1094 *bflagsp = scsi_get_device_flags(sdev, 1095 sdev->vendor, 1096 sdev->model); 1097 return SCSI_SCAN_LUN_PRESENT; 1098 } 1099 scsi_device_put(sdev); 1100 } else 1101 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1102 if (!sdev) 1103 goto out; 1104 1105 result = kmalloc(result_len, GFP_KERNEL); 1106 if (!result) 1107 goto out_free_sdev; 1108 1109 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1110 goto out_free_result; 1111 1112 if (bflagsp) 1113 *bflagsp = bflags; 1114 /* 1115 * result contains valid SCSI INQUIRY data. 1116 */ 1117 if ((result[0] >> 5) == 3) { 1118 /* 1119 * For a Peripheral qualifier 3 (011b), the SCSI 1120 * spec says: The device server is not capable of 1121 * supporting a physical device on this logical 1122 * unit. 1123 * 1124 * For disks, this implies that there is no 1125 * logical disk configured at sdev->lun, but there 1126 * is a target id responding. 1127 */ 1128 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1129 " peripheral qualifier of 3, device not" 1130 " added\n")) 1131 if (lun == 0) { 1132 SCSI_LOG_SCAN_BUS(1, { 1133 unsigned char vend[9]; 1134 unsigned char mod[17]; 1135 1136 sdev_printk(KERN_INFO, sdev, 1137 "scsi scan: consider passing scsi_mod." 1138 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1139 scsi_inq_str(vend, result, 8, 16), 1140 scsi_inq_str(mod, result, 16, 32)); 1141 }); 1142 1143 } 1144 1145 res = SCSI_SCAN_TARGET_PRESENT; 1146 goto out_free_result; 1147 } 1148 1149 /* 1150 * Some targets may set slight variations of PQ and PDT to signal 1151 * that no LUN is present, so don't add sdev in these cases. 1152 * Two specific examples are: 1153 * 1) NetApp targets: return PQ=1, PDT=0x1f 1154 * 2) IBM/2145 targets: return PQ=1, PDT=0 1155 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1156 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1157 * 1158 * References: 1159 * 1) SCSI SPC-3, pp. 145-146 1160 * PQ=1: "A peripheral device having the specified peripheral 1161 * device type is not connected to this logical unit. However, the 1162 * device server is capable of supporting the specified peripheral 1163 * device type on this logical unit." 1164 * PDT=0x1f: "Unknown or no device type" 1165 * 2) USB UFI 1.0, p. 20 1166 * PDT=00h Direct-access device (floppy) 1167 * PDT=1Fh none (no FDD connected to the requested logical unit) 1168 */ 1169 if (((result[0] >> 5) == 1 || 1170 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) && 1171 !scsi_is_wlun(lun)) { 1172 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1173 "scsi scan: peripheral device type" 1174 " of 31, no device added\n")); 1175 res = SCSI_SCAN_TARGET_PRESENT; 1176 goto out_free_result; 1177 } 1178 1179 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1180 if (res == SCSI_SCAN_LUN_PRESENT) { 1181 if (bflags & BLIST_KEY) { 1182 sdev->lockable = 0; 1183 scsi_unlock_floptical(sdev, result); 1184 } 1185 } 1186 1187 out_free_result: 1188 kfree(result); 1189 out_free_sdev: 1190 if (res == SCSI_SCAN_LUN_PRESENT) { 1191 if (sdevp) { 1192 if (scsi_device_get(sdev) == 0) { 1193 *sdevp = sdev; 1194 } else { 1195 __scsi_remove_device(sdev); 1196 res = SCSI_SCAN_NO_RESPONSE; 1197 } 1198 } 1199 } else 1200 __scsi_remove_device(sdev); 1201 out: 1202 return res; 1203 } 1204 1205 /** 1206 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1207 * @starget: pointer to target structure to scan 1208 * @bflags: black/white list flag for LUN 0 1209 * @scsi_level: Which version of the standard does this device adhere to 1210 * @rescan: passed to scsi_probe_add_lun() 1211 * 1212 * Description: 1213 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1214 * scanned) to some maximum lun until a LUN is found with no device 1215 * attached. Use the bflags to figure out any oddities. 1216 * 1217 * Modifies sdevscan->lun. 1218 **/ 1219 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1220 blist_flags_t bflags, int scsi_level, 1221 enum scsi_scan_mode rescan) 1222 { 1223 uint max_dev_lun; 1224 u64 sparse_lun, lun; 1225 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1226 1227 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1228 "scsi scan: Sequential scan\n")); 1229 1230 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1231 /* 1232 * If this device is known to support sparse multiple units, 1233 * override the other settings, and scan all of them. Normally, 1234 * SCSI-3 devices should be scanned via the REPORT LUNS. 1235 */ 1236 if (bflags & BLIST_SPARSELUN) { 1237 max_dev_lun = shost->max_lun; 1238 sparse_lun = 1; 1239 } else 1240 sparse_lun = 0; 1241 1242 /* 1243 * If less than SCSI_1_CCS, and no special lun scanning, stop 1244 * scanning; this matches 2.4 behaviour, but could just be a bug 1245 * (to continue scanning a SCSI_1_CCS device). 1246 * 1247 * This test is broken. We might not have any device on lun0 for 1248 * a sparselun device, and if that's the case then how would we 1249 * know the real scsi_level, eh? It might make sense to just not 1250 * scan any SCSI_1 device for non-0 luns, but that check would best 1251 * go into scsi_alloc_sdev() and just have it return null when asked 1252 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1253 * 1254 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1255 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1256 == 0)) 1257 return; 1258 */ 1259 /* 1260 * If this device is known to support multiple units, override 1261 * the other settings, and scan all of them. 1262 */ 1263 if (bflags & BLIST_FORCELUN) 1264 max_dev_lun = shost->max_lun; 1265 /* 1266 * REGAL CDC-4X: avoid hang after LUN 4 1267 */ 1268 if (bflags & BLIST_MAX5LUN) 1269 max_dev_lun = min(5U, max_dev_lun); 1270 /* 1271 * Do not scan SCSI-2 or lower device past LUN 7, unless 1272 * BLIST_LARGELUN. 1273 */ 1274 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1275 max_dev_lun = min(8U, max_dev_lun); 1276 else 1277 max_dev_lun = min(256U, max_dev_lun); 1278 1279 /* 1280 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1281 * until we reach the max, or no LUN is found and we are not 1282 * sparse_lun. 1283 */ 1284 for (lun = 1; lun < max_dev_lun; ++lun) 1285 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1286 NULL) != SCSI_SCAN_LUN_PRESENT) && 1287 !sparse_lun) 1288 return; 1289 } 1290 1291 /** 1292 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1293 * @starget: which target 1294 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1295 * @rescan: nonzero if we can skip code only needed on first scan 1296 * 1297 * Description: 1298 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1299 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1300 * 1301 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1302 * LUNs even if it's older than SCSI-3. 1303 * If BLIST_NOREPORTLUN is set, return 1 always. 1304 * If BLIST_NOLUN is set, return 0 always. 1305 * If starget->no_report_luns is set, return 1 always. 1306 * 1307 * Return: 1308 * 0: scan completed (or no memory, so further scanning is futile) 1309 * 1: could not scan with REPORT LUN 1310 **/ 1311 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1312 enum scsi_scan_mode rescan) 1313 { 1314 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1315 unsigned int length; 1316 u64 lun; 1317 unsigned int num_luns; 1318 unsigned int retries; 1319 int result; 1320 struct scsi_lun *lunp, *lun_data; 1321 struct scsi_sense_hdr sshdr; 1322 struct scsi_device *sdev; 1323 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1324 int ret = 0; 1325 1326 /* 1327 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1328 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1329 * support more than 8 LUNs. 1330 * Don't attempt if the target doesn't support REPORT LUNS. 1331 */ 1332 if (bflags & BLIST_NOREPORTLUN) 1333 return 1; 1334 if (starget->scsi_level < SCSI_2 && 1335 starget->scsi_level != SCSI_UNKNOWN) 1336 return 1; 1337 if (starget->scsi_level < SCSI_3 && 1338 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1339 return 1; 1340 if (bflags & BLIST_NOLUN) 1341 return 0; 1342 if (starget->no_report_luns) 1343 return 1; 1344 1345 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1346 sdev = scsi_alloc_sdev(starget, 0, NULL); 1347 if (!sdev) 1348 return 0; 1349 if (scsi_device_get(sdev)) { 1350 __scsi_remove_device(sdev); 1351 return 0; 1352 } 1353 } 1354 1355 /* 1356 * Allocate enough to hold the header (the same size as one scsi_lun) 1357 * plus the number of luns we are requesting. 511 was the default 1358 * value of the now removed max_report_luns parameter. 1359 */ 1360 length = (511 + 1) * sizeof(struct scsi_lun); 1361 retry: 1362 lun_data = kmalloc(length, GFP_KERNEL); 1363 if (!lun_data) { 1364 printk(ALLOC_FAILURE_MSG, __func__); 1365 goto out; 1366 } 1367 1368 scsi_cmd[0] = REPORT_LUNS; 1369 1370 /* 1371 * bytes 1 - 5: reserved, set to zero. 1372 */ 1373 memset(&scsi_cmd[1], 0, 5); 1374 1375 /* 1376 * bytes 6 - 9: length of the command. 1377 */ 1378 put_unaligned_be32(length, &scsi_cmd[6]); 1379 1380 scsi_cmd[10] = 0; /* reserved */ 1381 scsi_cmd[11] = 0; /* control */ 1382 1383 /* 1384 * We can get a UNIT ATTENTION, for example a power on/reset, so 1385 * retry a few times (like sd.c does for TEST UNIT READY). 1386 * Experience shows some combinations of adapter/devices get at 1387 * least two power on/resets. 1388 * 1389 * Illegal requests (for devices that do not support REPORT LUNS) 1390 * should come through as a check condition, and will not generate 1391 * a retry. 1392 */ 1393 for (retries = 0; retries < 3; retries++) { 1394 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1395 "scsi scan: Sending REPORT LUNS to (try %d)\n", 1396 retries)); 1397 1398 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1399 lun_data, length, &sshdr, 1400 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL); 1401 1402 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1403 "scsi scan: REPORT LUNS" 1404 " %s (try %d) result 0x%x\n", 1405 result ? "failed" : "successful", 1406 retries, result)); 1407 if (result == 0) 1408 break; 1409 else if (scsi_sense_valid(&sshdr)) { 1410 if (sshdr.sense_key != UNIT_ATTENTION) 1411 break; 1412 } 1413 } 1414 1415 if (result) { 1416 /* 1417 * The device probably does not support a REPORT LUN command 1418 */ 1419 ret = 1; 1420 goto out_err; 1421 } 1422 1423 /* 1424 * Get the length from the first four bytes of lun_data. 1425 */ 1426 if (get_unaligned_be32(lun_data->scsi_lun) + 1427 sizeof(struct scsi_lun) > length) { 1428 length = get_unaligned_be32(lun_data->scsi_lun) + 1429 sizeof(struct scsi_lun); 1430 kfree(lun_data); 1431 goto retry; 1432 } 1433 length = get_unaligned_be32(lun_data->scsi_lun); 1434 1435 num_luns = (length / sizeof(struct scsi_lun)); 1436 1437 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1438 "scsi scan: REPORT LUN scan\n")); 1439 1440 /* 1441 * Scan the luns in lun_data. The entry at offset 0 is really 1442 * the header, so start at 1 and go up to and including num_luns. 1443 */ 1444 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1445 lun = scsilun_to_int(lunp); 1446 1447 if (lun > sdev->host->max_lun) { 1448 sdev_printk(KERN_WARNING, sdev, 1449 "lun%llu has a LUN larger than" 1450 " allowed by the host adapter\n", lun); 1451 } else { 1452 int res; 1453 1454 res = scsi_probe_and_add_lun(starget, 1455 lun, NULL, NULL, rescan, NULL); 1456 if (res == SCSI_SCAN_NO_RESPONSE) { 1457 /* 1458 * Got some results, but now none, abort. 1459 */ 1460 sdev_printk(KERN_ERR, sdev, 1461 "Unexpected response" 1462 " from lun %llu while scanning, scan" 1463 " aborted\n", (unsigned long long)lun); 1464 break; 1465 } 1466 } 1467 } 1468 1469 out_err: 1470 kfree(lun_data); 1471 out: 1472 if (scsi_device_created(sdev)) 1473 /* 1474 * the sdev we used didn't appear in the report luns scan 1475 */ 1476 __scsi_remove_device(sdev); 1477 scsi_device_put(sdev); 1478 return ret; 1479 } 1480 1481 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1482 uint id, u64 lun, void *hostdata) 1483 { 1484 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1485 struct device *parent = &shost->shost_gendev; 1486 struct scsi_target *starget; 1487 1488 if (strncmp(scsi_scan_type, "none", 4) == 0) 1489 return ERR_PTR(-ENODEV); 1490 1491 starget = scsi_alloc_target(parent, channel, id); 1492 if (!starget) 1493 return ERR_PTR(-ENOMEM); 1494 scsi_autopm_get_target(starget); 1495 1496 mutex_lock(&shost->scan_mutex); 1497 if (!shost->async_scan) 1498 scsi_complete_async_scans(); 1499 1500 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1501 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1502 scsi_autopm_put_host(shost); 1503 } 1504 mutex_unlock(&shost->scan_mutex); 1505 scsi_autopm_put_target(starget); 1506 /* 1507 * paired with scsi_alloc_target(). Target will be destroyed unless 1508 * scsi_probe_and_add_lun made an underlying device visible 1509 */ 1510 scsi_target_reap(starget); 1511 put_device(&starget->dev); 1512 1513 return sdev; 1514 } 1515 EXPORT_SYMBOL(__scsi_add_device); 1516 1517 int scsi_add_device(struct Scsi_Host *host, uint channel, 1518 uint target, u64 lun) 1519 { 1520 struct scsi_device *sdev = 1521 __scsi_add_device(host, channel, target, lun, NULL); 1522 if (IS_ERR(sdev)) 1523 return PTR_ERR(sdev); 1524 1525 scsi_device_put(sdev); 1526 return 0; 1527 } 1528 EXPORT_SYMBOL(scsi_add_device); 1529 1530 void scsi_rescan_device(struct device *dev) 1531 { 1532 struct scsi_device *sdev = to_scsi_device(dev); 1533 1534 device_lock(dev); 1535 1536 scsi_attach_vpd(sdev); 1537 1538 if (sdev->handler && sdev->handler->rescan) 1539 sdev->handler->rescan(sdev); 1540 1541 if (dev->driver && try_module_get(dev->driver->owner)) { 1542 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1543 1544 if (drv->rescan) 1545 drv->rescan(dev); 1546 module_put(dev->driver->owner); 1547 } 1548 device_unlock(dev); 1549 } 1550 EXPORT_SYMBOL(scsi_rescan_device); 1551 1552 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1553 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1554 { 1555 struct Scsi_Host *shost = dev_to_shost(parent); 1556 blist_flags_t bflags = 0; 1557 int res; 1558 struct scsi_target *starget; 1559 1560 if (shost->this_id == id) 1561 /* 1562 * Don't scan the host adapter 1563 */ 1564 return; 1565 1566 starget = scsi_alloc_target(parent, channel, id); 1567 if (!starget) 1568 return; 1569 scsi_autopm_get_target(starget); 1570 1571 if (lun != SCAN_WILD_CARD) { 1572 /* 1573 * Scan for a specific host/chan/id/lun. 1574 */ 1575 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1576 goto out_reap; 1577 } 1578 1579 /* 1580 * Scan LUN 0, if there is some response, scan further. Ideally, we 1581 * would not configure LUN 0 until all LUNs are scanned. 1582 */ 1583 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1584 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1585 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1586 /* 1587 * The REPORT LUN did not scan the target, 1588 * do a sequential scan. 1589 */ 1590 scsi_sequential_lun_scan(starget, bflags, 1591 starget->scsi_level, rescan); 1592 } 1593 1594 out_reap: 1595 scsi_autopm_put_target(starget); 1596 /* 1597 * paired with scsi_alloc_target(): determine if the target has 1598 * any children at all and if not, nuke it 1599 */ 1600 scsi_target_reap(starget); 1601 1602 put_device(&starget->dev); 1603 } 1604 1605 /** 1606 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1607 * @parent: host to scan 1608 * @channel: channel to scan 1609 * @id: target id to scan 1610 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1611 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1612 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1613 * and SCSI_SCAN_MANUAL to force scanning even if 1614 * 'scan=manual' is set. 1615 * 1616 * Description: 1617 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1618 * and possibly all LUNs on the target id. 1619 * 1620 * First try a REPORT LUN scan, if that does not scan the target, do a 1621 * sequential scan of LUNs on the target id. 1622 **/ 1623 void scsi_scan_target(struct device *parent, unsigned int channel, 1624 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1625 { 1626 struct Scsi_Host *shost = dev_to_shost(parent); 1627 1628 if (strncmp(scsi_scan_type, "none", 4) == 0) 1629 return; 1630 1631 if (rescan != SCSI_SCAN_MANUAL && 1632 strncmp(scsi_scan_type, "manual", 6) == 0) 1633 return; 1634 1635 mutex_lock(&shost->scan_mutex); 1636 if (!shost->async_scan) 1637 scsi_complete_async_scans(); 1638 1639 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1640 __scsi_scan_target(parent, channel, id, lun, rescan); 1641 scsi_autopm_put_host(shost); 1642 } 1643 mutex_unlock(&shost->scan_mutex); 1644 } 1645 EXPORT_SYMBOL(scsi_scan_target); 1646 1647 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1648 unsigned int id, u64 lun, 1649 enum scsi_scan_mode rescan) 1650 { 1651 uint order_id; 1652 1653 if (id == SCAN_WILD_CARD) 1654 for (id = 0; id < shost->max_id; ++id) { 1655 /* 1656 * XXX adapter drivers when possible (FCP, iSCSI) 1657 * could modify max_id to match the current max, 1658 * not the absolute max. 1659 * 1660 * XXX add a shost id iterator, so for example, 1661 * the FC ID can be the same as a target id 1662 * without a huge overhead of sparse id's. 1663 */ 1664 if (shost->reverse_ordering) 1665 /* 1666 * Scan from high to low id. 1667 */ 1668 order_id = shost->max_id - id - 1; 1669 else 1670 order_id = id; 1671 __scsi_scan_target(&shost->shost_gendev, channel, 1672 order_id, lun, rescan); 1673 } 1674 else 1675 __scsi_scan_target(&shost->shost_gendev, channel, 1676 id, lun, rescan); 1677 } 1678 1679 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1680 unsigned int id, u64 lun, 1681 enum scsi_scan_mode rescan) 1682 { 1683 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1684 "%s: <%u:%u:%llu>\n", 1685 __func__, channel, id, lun)); 1686 1687 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1688 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1689 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1690 return -EINVAL; 1691 1692 mutex_lock(&shost->scan_mutex); 1693 if (!shost->async_scan) 1694 scsi_complete_async_scans(); 1695 1696 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1697 if (channel == SCAN_WILD_CARD) 1698 for (channel = 0; channel <= shost->max_channel; 1699 channel++) 1700 scsi_scan_channel(shost, channel, id, lun, 1701 rescan); 1702 else 1703 scsi_scan_channel(shost, channel, id, lun, rescan); 1704 scsi_autopm_put_host(shost); 1705 } 1706 mutex_unlock(&shost->scan_mutex); 1707 1708 return 0; 1709 } 1710 1711 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1712 { 1713 struct scsi_device *sdev; 1714 shost_for_each_device(sdev, shost) { 1715 /* target removed before the device could be added */ 1716 if (sdev->sdev_state == SDEV_DEL) 1717 continue; 1718 /* If device is already visible, skip adding it to sysfs */ 1719 if (sdev->is_visible) 1720 continue; 1721 if (!scsi_host_scan_allowed(shost) || 1722 scsi_sysfs_add_sdev(sdev) != 0) 1723 __scsi_remove_device(sdev); 1724 } 1725 } 1726 1727 /** 1728 * scsi_prep_async_scan - prepare for an async scan 1729 * @shost: the host which will be scanned 1730 * Returns: a cookie to be passed to scsi_finish_async_scan() 1731 * 1732 * Tells the midlayer this host is going to do an asynchronous scan. 1733 * It reserves the host's position in the scanning list and ensures 1734 * that other asynchronous scans started after this one won't affect the 1735 * ordering of the discovered devices. 1736 */ 1737 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1738 { 1739 struct async_scan_data *data = NULL; 1740 unsigned long flags; 1741 1742 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1743 return NULL; 1744 1745 mutex_lock(&shost->scan_mutex); 1746 if (shost->async_scan) { 1747 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1748 goto err; 1749 } 1750 1751 data = kmalloc(sizeof(*data), GFP_KERNEL); 1752 if (!data) 1753 goto err; 1754 data->shost = scsi_host_get(shost); 1755 if (!data->shost) 1756 goto err; 1757 init_completion(&data->prev_finished); 1758 1759 spin_lock_irqsave(shost->host_lock, flags); 1760 shost->async_scan = 1; 1761 spin_unlock_irqrestore(shost->host_lock, flags); 1762 mutex_unlock(&shost->scan_mutex); 1763 1764 spin_lock(&async_scan_lock); 1765 if (list_empty(&scanning_hosts)) 1766 complete(&data->prev_finished); 1767 list_add_tail(&data->list, &scanning_hosts); 1768 spin_unlock(&async_scan_lock); 1769 1770 return data; 1771 1772 err: 1773 mutex_unlock(&shost->scan_mutex); 1774 kfree(data); 1775 return NULL; 1776 } 1777 1778 /** 1779 * scsi_finish_async_scan - asynchronous scan has finished 1780 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1781 * 1782 * All the devices currently attached to this host have been found. 1783 * This function announces all the devices it has found to the rest 1784 * of the system. 1785 */ 1786 static void scsi_finish_async_scan(struct async_scan_data *data) 1787 { 1788 struct Scsi_Host *shost; 1789 unsigned long flags; 1790 1791 if (!data) 1792 return; 1793 1794 shost = data->shost; 1795 1796 mutex_lock(&shost->scan_mutex); 1797 1798 if (!shost->async_scan) { 1799 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1800 dump_stack(); 1801 mutex_unlock(&shost->scan_mutex); 1802 return; 1803 } 1804 1805 wait_for_completion(&data->prev_finished); 1806 1807 scsi_sysfs_add_devices(shost); 1808 1809 spin_lock_irqsave(shost->host_lock, flags); 1810 shost->async_scan = 0; 1811 spin_unlock_irqrestore(shost->host_lock, flags); 1812 1813 mutex_unlock(&shost->scan_mutex); 1814 1815 spin_lock(&async_scan_lock); 1816 list_del(&data->list); 1817 if (!list_empty(&scanning_hosts)) { 1818 struct async_scan_data *next = list_entry(scanning_hosts.next, 1819 struct async_scan_data, list); 1820 complete(&next->prev_finished); 1821 } 1822 spin_unlock(&async_scan_lock); 1823 1824 scsi_autopm_put_host(shost); 1825 scsi_host_put(shost); 1826 kfree(data); 1827 } 1828 1829 static void do_scsi_scan_host(struct Scsi_Host *shost) 1830 { 1831 if (shost->hostt->scan_finished) { 1832 unsigned long start = jiffies; 1833 if (shost->hostt->scan_start) 1834 shost->hostt->scan_start(shost); 1835 1836 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1837 msleep(10); 1838 } else { 1839 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1840 SCAN_WILD_CARD, 0); 1841 } 1842 } 1843 1844 static void do_scan_async(void *_data, async_cookie_t c) 1845 { 1846 struct async_scan_data *data = _data; 1847 struct Scsi_Host *shost = data->shost; 1848 1849 do_scsi_scan_host(shost); 1850 scsi_finish_async_scan(data); 1851 } 1852 1853 /** 1854 * scsi_scan_host - scan the given adapter 1855 * @shost: adapter to scan 1856 **/ 1857 void scsi_scan_host(struct Scsi_Host *shost) 1858 { 1859 struct async_scan_data *data; 1860 1861 if (strncmp(scsi_scan_type, "none", 4) == 0 || 1862 strncmp(scsi_scan_type, "manual", 6) == 0) 1863 return; 1864 if (scsi_autopm_get_host(shost) < 0) 1865 return; 1866 1867 data = scsi_prep_async_scan(shost); 1868 if (!data) { 1869 do_scsi_scan_host(shost); 1870 scsi_autopm_put_host(shost); 1871 return; 1872 } 1873 1874 /* register with the async subsystem so wait_for_device_probe() 1875 * will flush this work 1876 */ 1877 async_schedule(do_scan_async, data); 1878 1879 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 1880 } 1881 EXPORT_SYMBOL(scsi_scan_host); 1882 1883 void scsi_forget_host(struct Scsi_Host *shost) 1884 { 1885 struct scsi_device *sdev; 1886 unsigned long flags; 1887 1888 restart: 1889 spin_lock_irqsave(shost->host_lock, flags); 1890 list_for_each_entry(sdev, &shost->__devices, siblings) { 1891 if (sdev->sdev_state == SDEV_DEL) 1892 continue; 1893 spin_unlock_irqrestore(shost->host_lock, flags); 1894 __scsi_remove_device(sdev); 1895 goto restart; 1896 } 1897 spin_unlock_irqrestore(shost->host_lock, flags); 1898 } 1899 1900 /** 1901 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself 1902 * @shost: Host that needs a scsi_device 1903 * 1904 * Lock status: None assumed. 1905 * 1906 * Returns: The scsi_device or NULL 1907 * 1908 * Notes: 1909 * Attach a single scsi_device to the Scsi_Host - this should 1910 * be made to look like a "pseudo-device" that points to the 1911 * HA itself. 1912 * 1913 * Note - this device is not accessible from any high-level 1914 * drivers (including generics), which is probably not 1915 * optimal. We can add hooks later to attach. 1916 */ 1917 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1918 { 1919 struct scsi_device *sdev = NULL; 1920 struct scsi_target *starget; 1921 1922 mutex_lock(&shost->scan_mutex); 1923 if (!scsi_host_scan_allowed(shost)) 1924 goto out; 1925 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1926 if (!starget) 1927 goto out; 1928 1929 sdev = scsi_alloc_sdev(starget, 0, NULL); 1930 if (sdev) 1931 sdev->borken = 0; 1932 else 1933 scsi_target_reap(starget); 1934 put_device(&starget->dev); 1935 out: 1936 mutex_unlock(&shost->scan_mutex); 1937 return sdev; 1938 } 1939 EXPORT_SYMBOL(scsi_get_host_dev); 1940 1941 /** 1942 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself 1943 * @sdev: Host device to be freed 1944 * 1945 * Lock status: None assumed. 1946 * 1947 * Returns: Nothing 1948 */ 1949 void scsi_free_host_dev(struct scsi_device *sdev) 1950 { 1951 BUG_ON(sdev->id != sdev->host->this_id); 1952 1953 __scsi_remove_device(sdev); 1954 } 1955 EXPORT_SYMBOL(scsi_free_host_dev); 1956 1957