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 <linux/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 static 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_enable_async_suspend - Enable async suspend and resume 127 */ 128 void scsi_enable_async_suspend(struct device *dev) 129 { 130 /* 131 * If a user has disabled async probing a likely reason is due to a 132 * storage enclosure that does not inject staggered spin-ups. For 133 * safety, make resume synchronous as well in that case. 134 */ 135 if (strncmp(scsi_scan_type, "async", 5) != 0) 136 return; 137 /* Enable asynchronous suspend and resume. */ 138 device_enable_async_suspend(dev); 139 } 140 141 /** 142 * scsi_complete_async_scans - Wait for asynchronous scans to complete 143 * 144 * When this function returns, any host which started scanning before 145 * this function was called will have finished its scan. Hosts which 146 * started scanning after this function was called may or may not have 147 * finished. 148 */ 149 int scsi_complete_async_scans(void) 150 { 151 struct async_scan_data *data; 152 153 do { 154 scoped_guard(spinlock, &async_scan_lock) 155 if (list_empty(&scanning_hosts)) 156 return 0; 157 /* If we can't get memory immediately, that's OK. Just 158 * sleep a little. Even if we never get memory, the async 159 * scans will finish eventually. 160 */ 161 data = kmalloc(sizeof(*data), GFP_KERNEL); 162 if (!data) 163 msleep(1); 164 } while (!data); 165 166 data->shost = NULL; 167 init_completion(&data->prev_finished); 168 169 spin_lock(&async_scan_lock); 170 /* Check that there's still somebody else on the list */ 171 if (list_empty(&scanning_hosts)) 172 goto done; 173 list_add_tail(&data->list, &scanning_hosts); 174 spin_unlock(&async_scan_lock); 175 176 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 177 wait_for_completion(&data->prev_finished); 178 179 spin_lock(&async_scan_lock); 180 list_del(&data->list); 181 if (!list_empty(&scanning_hosts)) { 182 struct async_scan_data *next = list_entry(scanning_hosts.next, 183 struct async_scan_data, list); 184 complete(&next->prev_finished); 185 } 186 done: 187 spin_unlock(&async_scan_lock); 188 189 kfree(data); 190 return 0; 191 } 192 193 /** 194 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 195 * @sdev: scsi device to send command to 196 * @result: area to store the result of the MODE SENSE 197 * 198 * Description: 199 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 200 * Called for BLIST_KEY devices. 201 **/ 202 static void scsi_unlock_floptical(struct scsi_device *sdev, 203 unsigned char *result) 204 { 205 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 206 207 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n"); 208 scsi_cmd[0] = MODE_SENSE; 209 scsi_cmd[1] = 0; 210 scsi_cmd[2] = 0x2e; 211 scsi_cmd[3] = 0; 212 scsi_cmd[4] = 0x2a; /* size */ 213 scsi_cmd[5] = 0; 214 scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, result, 0x2a, 215 SCSI_TIMEOUT, 3, NULL); 216 } 217 218 static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, 219 unsigned int depth) 220 { 221 int new_shift = sbitmap_calculate_shift(depth); 222 bool need_alloc = !sdev->budget_map.map; 223 bool need_free = false; 224 unsigned int memflags; 225 int ret; 226 struct sbitmap sb_backup; 227 228 depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev)); 229 230 /* 231 * realloc if new shift is calculated, which is caused by setting 232 * up one new default queue depth after calling ->sdev_configure 233 */ 234 if (!need_alloc && new_shift != sdev->budget_map.shift) 235 need_alloc = need_free = true; 236 237 if (!need_alloc) 238 return 0; 239 240 /* 241 * Request queue has to be frozen for reallocating budget map, 242 * and here disk isn't added yet, so freezing is pretty fast 243 */ 244 if (need_free) { 245 memflags = blk_mq_freeze_queue(sdev->request_queue); 246 sb_backup = sdev->budget_map; 247 } 248 ret = sbitmap_init_node(&sdev->budget_map, 249 scsi_device_max_queue_depth(sdev), 250 new_shift, GFP_NOIO, 251 sdev->request_queue->node, false, true); 252 if (!ret) 253 sbitmap_resize(&sdev->budget_map, depth); 254 255 if (need_free) { 256 if (ret) 257 sdev->budget_map = sb_backup; 258 else 259 sbitmap_free(&sb_backup); 260 ret = 0; 261 blk_mq_unfreeze_queue(sdev->request_queue, memflags); 262 } 263 return ret; 264 } 265 266 /** 267 * scsi_alloc_sdev - allocate and setup a scsi_Device 268 * @starget: which target to allocate a &scsi_device for 269 * @lun: which lun 270 * @hostdata: usually NULL and set by ->sdev_init instead 271 * 272 * Description: 273 * Allocate, initialize for io, and return a pointer to a scsi_Device. 274 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 275 * adds scsi_Device to the appropriate list. 276 * 277 * Return value: 278 * scsi_Device pointer, or NULL on failure. 279 **/ 280 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 281 u64 lun, void *hostdata) 282 { 283 unsigned int depth; 284 struct scsi_device *sdev; 285 struct request_queue *q; 286 int display_failure_msg = 1, ret; 287 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 288 struct queue_limits lim; 289 290 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 291 GFP_KERNEL); 292 if (!sdev) 293 goto out; 294 295 sdev->vendor = scsi_null_device_strs; 296 sdev->model = scsi_null_device_strs; 297 sdev->rev = scsi_null_device_strs; 298 sdev->host = shost; 299 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 300 sdev->id = starget->id; 301 sdev->lun = lun; 302 sdev->channel = starget->channel; 303 mutex_init(&sdev->state_mutex); 304 sdev->sdev_state = SDEV_CREATED; 305 INIT_LIST_HEAD(&sdev->siblings); 306 INIT_LIST_HEAD(&sdev->same_target_siblings); 307 INIT_LIST_HEAD(&sdev->starved_entry); 308 INIT_LIST_HEAD(&sdev->event_list); 309 spin_lock_init(&sdev->list_lock); 310 mutex_init(&sdev->inquiry_mutex); 311 INIT_WORK(&sdev->event_work, scsi_evt_thread); 312 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 313 314 sdev->sdev_gendev.parent = get_device(&starget->dev); 315 sdev->sdev_target = starget; 316 317 /* usually NULL and set by ->sdev_init instead */ 318 sdev->hostdata = hostdata; 319 320 /* if the device needs this changing, it may do so in the 321 * sdev_configure function */ 322 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 323 324 /* 325 * Some low level driver could use device->type 326 */ 327 sdev->type = -1; 328 329 /* 330 * Assume that the device will have handshaking problems, 331 * and then fix this field later if it turns out it 332 * doesn't 333 */ 334 sdev->borken = 1; 335 336 sdev->sg_reserved_size = INT_MAX; 337 338 scsi_init_limits(shost, &lim); 339 q = blk_mq_alloc_queue(&sdev->host->tag_set, &lim, sdev); 340 if (IS_ERR(q)) { 341 /* release fn is set up in scsi_sysfs_device_initialise, so 342 * have to free and put manually here */ 343 put_device(&starget->dev); 344 kfree(sdev); 345 goto out; 346 } 347 kref_get(&sdev->host->tagset_refcnt); 348 sdev->request_queue = q; 349 350 scsi_sysfs_device_initialize(sdev); 351 352 if (scsi_device_is_pseudo_dev(sdev)) 353 return sdev; 354 355 depth = sdev->host->cmd_per_lun ?: 1; 356 357 /* 358 * Use .can_queue as budget map's depth because we have to 359 * support adjusting queue depth from sysfs. Meantime use 360 * default device queue depth to figure out sbitmap shift 361 * since we use this queue depth most of times. 362 */ 363 if (scsi_realloc_sdev_budget_map(sdev, depth)) { 364 put_device(&starget->dev); 365 kfree(sdev); 366 goto out; 367 } 368 369 scsi_change_queue_depth(sdev, depth); 370 371 if (shost->hostt->sdev_init) { 372 ret = shost->hostt->sdev_init(sdev); 373 if (ret) { 374 /* 375 * if LLDD reports slave not present, don't clutter 376 * console with alloc failure messages 377 */ 378 if (ret == -ENXIO) 379 display_failure_msg = 0; 380 goto out_device_destroy; 381 } 382 } 383 384 return sdev; 385 386 out_device_destroy: 387 __scsi_remove_device(sdev); 388 out: 389 if (display_failure_msg) 390 printk(ALLOC_FAILURE_MSG, __func__); 391 return NULL; 392 } 393 394 static void scsi_target_destroy(struct scsi_target *starget) 395 { 396 struct device *dev = &starget->dev; 397 struct Scsi_Host *shost = dev_to_shost(dev->parent); 398 unsigned long flags; 399 400 BUG_ON(starget->state == STARGET_DEL); 401 starget->state = STARGET_DEL; 402 transport_destroy_device(dev); 403 spin_lock_irqsave(shost->host_lock, flags); 404 if (shost->hostt->target_destroy) 405 shost->hostt->target_destroy(starget); 406 list_del_init(&starget->siblings); 407 spin_unlock_irqrestore(shost->host_lock, flags); 408 put_device(dev); 409 } 410 411 static void scsi_target_dev_release(struct device *dev) 412 { 413 struct device *parent = dev->parent; 414 struct scsi_target *starget = to_scsi_target(dev); 415 416 kfree(starget); 417 put_device(parent); 418 } 419 420 static const struct device_type scsi_target_type = { 421 .name = "scsi_target", 422 .release = scsi_target_dev_release, 423 }; 424 425 int scsi_is_target_device(const struct device *dev) 426 { 427 return dev->type == &scsi_target_type; 428 } 429 EXPORT_SYMBOL(scsi_is_target_device); 430 431 static struct scsi_target *__scsi_find_target(struct device *parent, 432 int channel, uint id) 433 { 434 struct scsi_target *starget, *found_starget = NULL; 435 struct Scsi_Host *shost = dev_to_shost(parent); 436 /* 437 * Search for an existing target for this sdev. 438 */ 439 list_for_each_entry(starget, &shost->__targets, siblings) { 440 if (starget->id == id && 441 starget->channel == channel) { 442 found_starget = starget; 443 break; 444 } 445 } 446 if (found_starget) 447 get_device(&found_starget->dev); 448 449 return found_starget; 450 } 451 452 /** 453 * scsi_target_reap_ref_release - remove target from visibility 454 * @kref: the reap_ref in the target being released 455 * 456 * Called on last put of reap_ref, which is the indication that no device 457 * under this target is visible anymore, so render the target invisible in 458 * sysfs. Note: we have to be in user context here because the target reaps 459 * should be done in places where the scsi device visibility is being removed. 460 */ 461 static void scsi_target_reap_ref_release(struct kref *kref) 462 { 463 struct scsi_target *starget 464 = container_of(kref, struct scsi_target, reap_ref); 465 466 /* 467 * if we get here and the target is still in a CREATED state that 468 * means it was allocated but never made visible (because a scan 469 * turned up no LUNs), so don't call device_del() on it. 470 */ 471 if ((starget->state != STARGET_CREATED) && 472 (starget->state != STARGET_CREATED_REMOVE)) { 473 transport_remove_device(&starget->dev); 474 device_del(&starget->dev); 475 } 476 scsi_target_destroy(starget); 477 } 478 479 static void scsi_target_reap_ref_put(struct scsi_target *starget) 480 { 481 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 482 } 483 484 /** 485 * scsi_alloc_target - allocate a new or find an existing target 486 * @parent: parent of the target (need not be a scsi host) 487 * @channel: target channel number (zero if no channels) 488 * @id: target id number 489 * 490 * Return an existing target if one exists, provided it hasn't already 491 * gone into STARGET_DEL state, otherwise allocate a new target. 492 * 493 * The target is returned with an incremented reference, so the caller 494 * is responsible for both reaping and doing a last put 495 */ 496 static struct scsi_target *scsi_alloc_target(struct device *parent, 497 int channel, uint id) 498 { 499 struct Scsi_Host *shost = dev_to_shost(parent); 500 struct device *dev = NULL; 501 unsigned long flags; 502 const int size = sizeof(struct scsi_target) 503 + shost->transportt->target_size; 504 struct scsi_target *starget; 505 struct scsi_target *found_target; 506 int error, ref_got; 507 508 starget = kzalloc(size, GFP_KERNEL); 509 if (!starget) { 510 printk(KERN_ERR "%s: allocation failure\n", __func__); 511 return NULL; 512 } 513 dev = &starget->dev; 514 device_initialize(dev); 515 kref_init(&starget->reap_ref); 516 dev->parent = get_device(parent); 517 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 518 dev->bus = &scsi_bus_type; 519 dev->type = &scsi_target_type; 520 scsi_enable_async_suspend(dev); 521 starget->id = id; 522 starget->channel = channel; 523 starget->can_queue = 0; 524 INIT_LIST_HEAD(&starget->siblings); 525 INIT_LIST_HEAD(&starget->devices); 526 starget->state = STARGET_CREATED; 527 starget->scsi_level = SCSI_2; 528 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 529 retry: 530 spin_lock_irqsave(shost->host_lock, flags); 531 532 found_target = __scsi_find_target(parent, channel, id); 533 if (found_target) 534 goto found; 535 536 list_add_tail(&starget->siblings, &shost->__targets); 537 spin_unlock_irqrestore(shost->host_lock, flags); 538 /* allocate and add */ 539 transport_setup_device(dev); 540 if (shost->hostt->target_alloc) { 541 error = shost->hostt->target_alloc(starget); 542 543 if(error) { 544 if (error != -ENXIO) 545 dev_err(dev, "target allocation failed, error %d\n", error); 546 /* don't want scsi_target_reap to do the final 547 * put because it will be under the host lock */ 548 scsi_target_destroy(starget); 549 return NULL; 550 } 551 } 552 get_device(dev); 553 554 return starget; 555 556 found: 557 /* 558 * release routine already fired if kref is zero, so if we can still 559 * take the reference, the target must be alive. If we can't, it must 560 * be dying and we need to wait for a new target 561 */ 562 ref_got = kref_get_unless_zero(&found_target->reap_ref); 563 564 spin_unlock_irqrestore(shost->host_lock, flags); 565 if (ref_got) { 566 put_device(dev); 567 return found_target; 568 } 569 /* 570 * Unfortunately, we found a dying target; need to wait until it's 571 * dead before we can get a new one. There is an anomaly here. We 572 * *should* call scsi_target_reap() to balance the kref_get() of the 573 * reap_ref above. However, since the target being released, it's 574 * already invisible and the reap_ref is irrelevant. If we call 575 * scsi_target_reap() we might spuriously do another device_del() on 576 * an already invisible target. 577 */ 578 put_device(&found_target->dev); 579 /* 580 * length of time is irrelevant here, we just want to yield the CPU 581 * for a tick to avoid busy waiting for the target to die. 582 */ 583 msleep(1); 584 goto retry; 585 } 586 587 /** 588 * scsi_target_reap - check to see if target is in use and destroy if not 589 * @starget: target to be checked 590 * 591 * This is used after removing a LUN or doing a last put of the target 592 * it checks atomically that nothing is using the target and removes 593 * it if so. 594 */ 595 void scsi_target_reap(struct scsi_target *starget) 596 { 597 /* 598 * serious problem if this triggers: STARGET_DEL is only set in the if 599 * the reap_ref drops to zero, so we're trying to do another final put 600 * on an already released kref 601 */ 602 BUG_ON(starget->state == STARGET_DEL); 603 scsi_target_reap_ref_put(starget); 604 } 605 606 /** 607 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 608 * INQUIRY result string 609 * @s: INQUIRY result string to sanitize 610 * @len: length of the string 611 * 612 * Description: 613 * The SCSI spec says that INQUIRY vendor, product, and revision 614 * strings must consist entirely of graphic ASCII characters, 615 * padded on the right with spaces. Since not all devices obey 616 * this rule, we will replace non-graphic or non-ASCII characters 617 * with spaces. Exception: a NUL character is interpreted as a 618 * string terminator, so all the following characters are set to 619 * spaces. 620 **/ 621 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 622 { 623 int terminated = 0; 624 625 for (; len > 0; (--len, ++s)) { 626 if (*s == 0) 627 terminated = 1; 628 if (terminated || *s < 0x20 || *s > 0x7e) 629 *s = ' '; 630 } 631 } 632 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 633 634 635 /** 636 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 637 * @sdev: scsi_device to probe 638 * @inq_result: area to store the INQUIRY result 639 * @result_len: len of inq_result 640 * @bflags: store any bflags found here 641 * 642 * Description: 643 * Probe the lun associated with @req using a standard SCSI INQUIRY; 644 * 645 * If the INQUIRY is successful, zero is returned and the 646 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 647 * are copied to the scsi_device any flags value is stored in *@bflags. 648 **/ 649 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 650 int result_len, blist_flags_t *bflags) 651 { 652 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 653 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 654 int response_len = 0; 655 int pass, count, result, resid; 656 struct scsi_failure failure_defs[] = { 657 /* 658 * not-ready to ready transition [asc/ascq=0x28/0x0] or 659 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY 660 * should not yield UNIT_ATTENTION but many buggy devices do 661 * so anyway. 662 */ 663 { 664 .sense = UNIT_ATTENTION, 665 .asc = 0x28, 666 .result = SAM_STAT_CHECK_CONDITION, 667 }, 668 { 669 .sense = UNIT_ATTENTION, 670 .asc = 0x29, 671 .result = SAM_STAT_CHECK_CONDITION, 672 }, 673 { 674 .allowed = 1, 675 .result = DID_TIME_OUT << 16, 676 }, 677 {} 678 }; 679 struct scsi_failures failures = { 680 .total_allowed = 3, 681 .failure_definitions = failure_defs, 682 }; 683 const struct scsi_exec_args exec_args = { 684 .resid = &resid, 685 .failures = &failures, 686 }; 687 688 *bflags = 0; 689 690 /* Perform up to 3 passes. The first pass uses a conservative 691 * transfer length of 36 unless sdev->inquiry_len specifies a 692 * different value. */ 693 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 694 try_inquiry_len = first_inquiry_len; 695 pass = 1; 696 697 next_pass: 698 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 699 "scsi scan: INQUIRY pass %d length %d\n", 700 pass, try_inquiry_len)); 701 702 /* Each pass gets up to three chances to ignore Unit Attention */ 703 scsi_failures_reset_retries(&failures); 704 705 for (count = 0; count < 3; ++count) { 706 memset(scsi_cmd, 0, 6); 707 scsi_cmd[0] = INQUIRY; 708 scsi_cmd[4] = (unsigned char) try_inquiry_len; 709 710 memset(inq_result, 0, try_inquiry_len); 711 712 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 713 inq_result, try_inquiry_len, 714 HZ / 2 + HZ * scsi_inq_timeout, 3, 715 &exec_args); 716 717 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 718 "scsi scan: INQUIRY %s with code 0x%x\n", 719 result ? "failed" : "successful", result)); 720 721 if (result == 0) { 722 /* 723 * if nothing was transferred, we try 724 * again. It's a workaround for some USB 725 * devices. 726 */ 727 if (resid == try_inquiry_len) 728 continue; 729 } 730 break; 731 } 732 733 if (result == 0) { 734 scsi_sanitize_inquiry_string(&inq_result[8], 8); 735 scsi_sanitize_inquiry_string(&inq_result[16], 16); 736 scsi_sanitize_inquiry_string(&inq_result[32], 4); 737 738 response_len = inq_result[4] + 5; 739 if (response_len > 255) 740 response_len = first_inquiry_len; /* sanity */ 741 742 /* 743 * Get any flags for this device. 744 * 745 * XXX add a bflags to scsi_device, and replace the 746 * corresponding bit fields in scsi_device, so bflags 747 * need not be passed as an argument. 748 */ 749 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 750 &inq_result[16]); 751 752 /* When the first pass succeeds we gain information about 753 * what larger transfer lengths might work. */ 754 if (pass == 1) { 755 if (BLIST_INQUIRY_36 & *bflags) 756 next_inquiry_len = 36; 757 /* 758 * LLD specified a maximum sdev->inquiry_len 759 * but device claims it has more data. Capping 760 * the length only makes sense for legacy 761 * devices. If a device supports SPC-4 (2014) 762 * or newer, assume that it is safe to ask for 763 * as much as the device says it supports. 764 */ 765 else if (sdev->inquiry_len && 766 response_len > sdev->inquiry_len && 767 (inq_result[2] & 0x7) < 6) /* SPC-4 */ 768 next_inquiry_len = sdev->inquiry_len; 769 else 770 next_inquiry_len = response_len; 771 772 /* If more data is available perform the second pass */ 773 if (next_inquiry_len > try_inquiry_len) { 774 try_inquiry_len = next_inquiry_len; 775 pass = 2; 776 goto next_pass; 777 } 778 } 779 780 } else if (pass == 2) { 781 sdev_printk(KERN_INFO, sdev, 782 "scsi scan: %d byte inquiry failed. " 783 "Consider BLIST_INQUIRY_36 for this device\n", 784 try_inquiry_len); 785 786 /* If this pass failed, the third pass goes back and transfers 787 * the same amount as we successfully got in the first pass. */ 788 try_inquiry_len = first_inquiry_len; 789 pass = 3; 790 goto next_pass; 791 } 792 793 /* If the last transfer attempt got an error, assume the 794 * peripheral doesn't exist or is dead. */ 795 if (result) 796 return -EIO; 797 798 /* Don't report any more data than the device says is valid */ 799 sdev->inquiry_len = min(try_inquiry_len, response_len); 800 801 /* 802 * XXX Abort if the response length is less than 36? If less than 803 * 32, the lookup of the device flags (above) could be invalid, 804 * and it would be possible to take an incorrect action - we do 805 * not want to hang because of a short INQUIRY. On the flip side, 806 * if the device is spun down or becoming ready (and so it gives a 807 * short INQUIRY), an abort here prevents any further use of the 808 * device, including spin up. 809 * 810 * On the whole, the best approach seems to be to assume the first 811 * 36 bytes are valid no matter what the device says. That's 812 * better than copying < 36 bytes to the inquiry-result buffer 813 * and displaying garbage for the Vendor, Product, or Revision 814 * strings. 815 */ 816 if (sdev->inquiry_len < 36) { 817 if (!sdev->host->short_inquiry) { 818 shost_printk(KERN_INFO, sdev->host, 819 "scsi scan: INQUIRY result too short (%d)," 820 " using 36\n", sdev->inquiry_len); 821 sdev->host->short_inquiry = 1; 822 } 823 sdev->inquiry_len = 36; 824 } 825 826 /* 827 * Related to the above issue: 828 * 829 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 830 * and if not ready, sent a START_STOP to start (maybe spin up) and 831 * then send the INQUIRY again, since the INQUIRY can change after 832 * a device is initialized. 833 * 834 * Ideally, start a device if explicitly asked to do so. This 835 * assumes that a device is spun up on power on, spun down on 836 * request, and then spun up on request. 837 */ 838 839 /* 840 * The scanning code needs to know the scsi_level, even if no 841 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 842 * non-zero LUNs can be scanned. 843 */ 844 sdev->scsi_level = inq_result[2] & 0x0f; 845 if (sdev->scsi_level >= 2 || 846 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 847 sdev->scsi_level++; 848 sdev->sdev_target->scsi_level = sdev->scsi_level; 849 850 /* 851 * If SCSI-2 or lower, and if the transport requires it, 852 * store the LUN value in CDB[1]. 853 */ 854 sdev->lun_in_cdb = 0; 855 if (sdev->scsi_level <= SCSI_2 && 856 sdev->scsi_level != SCSI_UNKNOWN && 857 !sdev->host->no_scsi2_lun_in_cdb) 858 sdev->lun_in_cdb = 1; 859 860 return 0; 861 } 862 863 /** 864 * scsi_add_lun - allocate and fully initialze a scsi_device 865 * @sdev: holds information to be stored in the new scsi_device 866 * @inq_result: holds the result of a previous INQUIRY to the LUN 867 * @bflags: black/white list flag 868 * @async: 1 if this device is being scanned asynchronously 869 * 870 * Description: 871 * Initialize the scsi_device @sdev. Optionally set fields based 872 * on values in *@bflags. 873 * 874 * Return: 875 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 876 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 877 **/ 878 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 879 blist_flags_t *bflags, int async) 880 { 881 const struct scsi_host_template *hostt = sdev->host->hostt; 882 struct queue_limits lim; 883 int ret; 884 885 /* 886 * XXX do not save the inquiry, since it can change underneath us, 887 * save just vendor/model/rev. 888 * 889 * Rather than save it and have an ioctl that retrieves the saved 890 * value, have an ioctl that executes the same INQUIRY code used 891 * in scsi_probe_lun, let user level programs doing INQUIRY 892 * scanning run at their own risk, or supply a user level program 893 * that can correctly scan. 894 */ 895 896 /* 897 * Copy at least 36 bytes of INQUIRY data, so that we don't 898 * dereference unallocated memory when accessing the Vendor, 899 * Product, and Revision strings. Badly behaved devices may set 900 * the INQUIRY Additional Length byte to a small value, indicating 901 * these strings are invalid, but often they contain plausible data 902 * nonetheless. It doesn't matter if the device sent < 36 bytes 903 * total, since scsi_probe_lun() initializes inq_result with 0s. 904 */ 905 sdev->inquiry = kmemdup(inq_result, 906 max_t(size_t, sdev->inquiry_len, 36), 907 GFP_KERNEL); 908 if (sdev->inquiry == NULL) 909 return SCSI_SCAN_NO_RESPONSE; 910 911 sdev->vendor = (char *) (sdev->inquiry + 8); 912 sdev->model = (char *) (sdev->inquiry + 16); 913 sdev->rev = (char *) (sdev->inquiry + 32); 914 915 sdev->is_ata = strncmp(sdev->vendor, "ATA ", 8) == 0; 916 if (sdev->is_ata) { 917 /* 918 * sata emulation layer device. This is a hack to work around 919 * the SATL power management specifications which state that 920 * when the SATL detects the device has gone into standby 921 * mode, it shall respond with NOT READY. 922 */ 923 sdev->allow_restart = 1; 924 } 925 926 if (*bflags & BLIST_ISROM) { 927 sdev->type = TYPE_ROM; 928 sdev->removable = 1; 929 } else { 930 sdev->type = (inq_result[0] & 0x1f); 931 sdev->removable = (inq_result[1] & 0x80) >> 7; 932 933 /* 934 * some devices may respond with wrong type for 935 * well-known logical units. Force well-known type 936 * to enumerate them correctly. 937 */ 938 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 939 sdev_printk(KERN_WARNING, sdev, 940 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 941 __func__, sdev->type, (unsigned int)sdev->lun); 942 sdev->type = TYPE_WLUN; 943 } 944 945 } 946 947 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 948 /* RBC and MMC devices can return SCSI-3 compliance and yet 949 * still not support REPORT LUNS, so make them act as 950 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 951 * specifically set */ 952 if ((*bflags & BLIST_REPORTLUN2) == 0) 953 *bflags |= BLIST_NOREPORTLUN; 954 } 955 956 /* 957 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 958 * spec says: The device server is capable of supporting the 959 * specified peripheral device type on this logical unit. However, 960 * the physical device is not currently connected to this logical 961 * unit. 962 * 963 * The above is vague, as it implies that we could treat 001 and 964 * 011 the same. Stay compatible with previous code, and create a 965 * scsi_device for a PQ of 1 966 * 967 * Don't set the device offline here; rather let the upper 968 * level drivers eval the PQ to decide whether they should 969 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 970 */ 971 972 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 973 sdev->lockable = sdev->removable; 974 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 975 976 if (sdev->scsi_level >= SCSI_3 || 977 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 978 sdev->ppr = 1; 979 if (inq_result[7] & 0x60) 980 sdev->wdtr = 1; 981 if (inq_result[7] & 0x10) 982 sdev->sdtr = 1; 983 984 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 985 "ANSI: %d%s\n", scsi_device_type(sdev->type), 986 sdev->vendor, sdev->model, sdev->rev, 987 sdev->inq_periph_qual, inq_result[2] & 0x07, 988 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 989 990 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 991 !(*bflags & BLIST_NOTQ)) { 992 sdev->tagged_supported = 1; 993 sdev->simple_tags = 1; 994 } 995 996 /* 997 * Some devices (Texel CD ROM drives) have handshaking problems 998 * when used with the Seagate controllers. borken is initialized 999 * to 1, and then set it to 0 here. 1000 */ 1001 if ((*bflags & BLIST_BORKEN) == 0) 1002 sdev->borken = 0; 1003 1004 if (*bflags & BLIST_NO_ULD_ATTACH) 1005 sdev->no_uld_attach = 1; 1006 1007 /* 1008 * Apparently some really broken devices (contrary to the SCSI 1009 * standards) need to be selected without asserting ATN 1010 */ 1011 if (*bflags & BLIST_SELECT_NO_ATN) 1012 sdev->select_no_atn = 1; 1013 1014 /* 1015 * Some devices may not want to have a start command automatically 1016 * issued when a device is added. 1017 */ 1018 if (*bflags & BLIST_NOSTARTONADD) 1019 sdev->no_start_on_add = 1; 1020 1021 if (*bflags & BLIST_SINGLELUN) 1022 scsi_target(sdev)->single_lun = 1; 1023 1024 sdev->use_10_for_rw = 1; 1025 1026 /* some devices don't like REPORT SUPPORTED OPERATION CODES 1027 * and will simply timeout causing sd_mod init to take a very 1028 * very long time */ 1029 if (*bflags & BLIST_NO_RSOC) 1030 sdev->no_report_opcodes = 1; 1031 1032 /* set the device running here so that slave configure 1033 * may do I/O */ 1034 mutex_lock(&sdev->state_mutex); 1035 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 1036 if (ret) 1037 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 1038 mutex_unlock(&sdev->state_mutex); 1039 1040 if (ret) { 1041 sdev_printk(KERN_ERR, sdev, 1042 "in wrong state %s to complete scan\n", 1043 scsi_device_state_name(sdev->sdev_state)); 1044 return SCSI_SCAN_NO_RESPONSE; 1045 } 1046 1047 if (*bflags & BLIST_NOT_LOCKABLE) 1048 sdev->lockable = 0; 1049 1050 if (*bflags & BLIST_RETRY_HWERROR) 1051 sdev->retry_hwerror = 1; 1052 1053 if (*bflags & BLIST_NO_DIF) 1054 sdev->no_dif = 1; 1055 1056 if (*bflags & BLIST_UNMAP_LIMIT_WS) 1057 sdev->unmap_limit_for_ws = 1; 1058 1059 if (*bflags & BLIST_IGN_MEDIA_CHANGE) 1060 sdev->ignore_media_change = 1; 1061 1062 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 1063 1064 if (*bflags & BLIST_TRY_VPD_PAGES) 1065 sdev->try_vpd_pages = 1; 1066 else if (*bflags & BLIST_SKIP_VPD_PAGES) 1067 sdev->skip_vpd_pages = 1; 1068 1069 if (*bflags & BLIST_NO_VPD_SIZE) 1070 sdev->no_vpd_size = 1; 1071 1072 transport_configure_device(&sdev->sdev_gendev); 1073 1074 sdev->sdev_bflags = *bflags; 1075 1076 if (scsi_device_is_pseudo_dev(sdev)) 1077 return SCSI_SCAN_LUN_PRESENT; 1078 1079 /* 1080 * No need to freeze the queue as it isn't reachable to anyone else yet. 1081 */ 1082 lim = queue_limits_start_update(sdev->request_queue); 1083 if (*bflags & BLIST_MAX_512) 1084 lim.max_hw_sectors = 512; 1085 else if (*bflags & BLIST_MAX_1024) 1086 lim.max_hw_sectors = 1024; 1087 1088 if (hostt->sdev_configure) 1089 ret = hostt->sdev_configure(sdev, &lim); 1090 if (ret) { 1091 queue_limits_cancel_update(sdev->request_queue); 1092 /* 1093 * If the LLDD reports device not present, don't clutter the 1094 * console with failure messages. 1095 */ 1096 if (ret != -ENXIO) 1097 sdev_printk(KERN_ERR, sdev, 1098 "failed to configure device\n"); 1099 return SCSI_SCAN_NO_RESPONSE; 1100 } 1101 1102 ret = queue_limits_commit_update(sdev->request_queue, &lim); 1103 if (ret) { 1104 sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n"); 1105 return SCSI_SCAN_NO_RESPONSE; 1106 } 1107 1108 /* 1109 * The queue_depth is often changed in ->sdev_configure. 1110 * 1111 * Set up budget map again since memory consumption of the map depends 1112 * on actual queue depth. 1113 */ 1114 if (hostt->sdev_configure) 1115 scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth); 1116 1117 if (sdev->scsi_level >= SCSI_3) 1118 scsi_attach_vpd(sdev); 1119 1120 scsi_cdl_check(sdev); 1121 1122 sdev->max_queue_depth = sdev->queue_depth; 1123 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); 1124 1125 /* 1126 * Ok, the device is now all set up, we can 1127 * register it and tell the rest of the kernel 1128 * about it. 1129 */ 1130 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 1131 return SCSI_SCAN_NO_RESPONSE; 1132 1133 return SCSI_SCAN_LUN_PRESENT; 1134 } 1135 1136 #ifdef CONFIG_SCSI_LOGGING 1137 /** 1138 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1139 * @buf: Output buffer with at least end-first+1 bytes of space 1140 * @inq: Inquiry buffer (input) 1141 * @first: Offset of string into inq 1142 * @end: Index after last character in inq 1143 */ 1144 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1145 unsigned first, unsigned end) 1146 { 1147 unsigned term = 0, idx; 1148 1149 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1150 if (inq[idx+first] > ' ') { 1151 buf[idx] = inq[idx+first]; 1152 term = idx+1; 1153 } else { 1154 buf[idx] = ' '; 1155 } 1156 } 1157 buf[term] = 0; 1158 return buf; 1159 } 1160 #endif 1161 1162 /** 1163 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1164 * @starget: pointer to target device structure 1165 * @lun: LUN of target device 1166 * @bflagsp: store bflags here if not NULL 1167 * @sdevp: probe the LUN corresponding to this scsi_device 1168 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1169 * needed on first scan 1170 * @hostdata: passed to scsi_alloc_sdev() 1171 * 1172 * Description: 1173 * Call scsi_probe_lun, if a LUN with an attached device is found, 1174 * allocate and set it up by calling scsi_add_lun. 1175 * 1176 * Return: 1177 * 1178 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1179 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1180 * attached at the LUN 1181 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1182 **/ 1183 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1184 u64 lun, blist_flags_t *bflagsp, 1185 struct scsi_device **sdevp, 1186 enum scsi_scan_mode rescan, 1187 void *hostdata) 1188 { 1189 struct scsi_device *sdev; 1190 unsigned char *result; 1191 blist_flags_t bflags; 1192 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1193 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1194 1195 /* 1196 * The rescan flag is used as an optimization, the first scan of a 1197 * host adapter calls into here with rescan == 0. 1198 */ 1199 sdev = scsi_device_lookup_by_target(starget, lun); 1200 if (sdev) { 1201 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1202 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1203 "scsi scan: device exists on %s\n", 1204 dev_name(&sdev->sdev_gendev))); 1205 if (sdevp) 1206 *sdevp = sdev; 1207 else 1208 scsi_device_put(sdev); 1209 1210 if (bflagsp) 1211 *bflagsp = scsi_get_device_flags(sdev, 1212 sdev->vendor, 1213 sdev->model); 1214 return SCSI_SCAN_LUN_PRESENT; 1215 } 1216 scsi_device_put(sdev); 1217 } else 1218 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1219 if (!sdev) 1220 goto out; 1221 1222 if (scsi_device_is_pseudo_dev(sdev)) { 1223 if (bflagsp) 1224 *bflagsp = BLIST_NOLUN; 1225 return SCSI_SCAN_LUN_PRESENT; 1226 } 1227 1228 result = kmalloc(result_len, GFP_KERNEL); 1229 if (!result) 1230 goto out_free_sdev; 1231 1232 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1233 goto out_free_result; 1234 1235 if (bflagsp) 1236 *bflagsp = bflags; 1237 /* 1238 * result contains valid SCSI INQUIRY data. 1239 */ 1240 if ((result[0] >> 5) == 3) { 1241 /* 1242 * For a Peripheral qualifier 3 (011b), the SCSI 1243 * spec says: The device server is not capable of 1244 * supporting a physical device on this logical 1245 * unit. 1246 * 1247 * For disks, this implies that there is no 1248 * logical disk configured at sdev->lun, but there 1249 * is a target id responding. 1250 */ 1251 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1252 " peripheral qualifier of 3, device not" 1253 " added\n")) 1254 if (lun == 0) { 1255 SCSI_LOG_SCAN_BUS(1, { 1256 unsigned char vend[9]; 1257 unsigned char mod[17]; 1258 1259 sdev_printk(KERN_INFO, sdev, 1260 "scsi scan: consider passing scsi_mod." 1261 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1262 scsi_inq_str(vend, result, 8, 16), 1263 scsi_inq_str(mod, result, 16, 32)); 1264 }); 1265 1266 } 1267 1268 res = SCSI_SCAN_TARGET_PRESENT; 1269 goto out_free_result; 1270 } 1271 1272 /* 1273 * Some targets may set slight variations of PQ and PDT to signal 1274 * that no LUN is present, so don't add sdev in these cases. 1275 * Two specific examples are: 1276 * 1) NetApp targets: return PQ=1, PDT=0x1f 1277 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1278 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1279 * 1280 * References: 1281 * 1) SCSI SPC-3, pp. 145-146 1282 * PQ=1: "A peripheral device having the specified peripheral 1283 * device type is not connected to this logical unit. However, the 1284 * device server is capable of supporting the specified peripheral 1285 * device type on this logical unit." 1286 * PDT=0x1f: "Unknown or no device type" 1287 * 2) USB UFI 1.0, p. 20 1288 * PDT=00h Direct-access device (floppy) 1289 * PDT=1Fh none (no FDD connected to the requested logical unit) 1290 */ 1291 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1292 (result[0] & 0x1f) == 0x1f && 1293 !scsi_is_wlun(lun)) { 1294 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1295 "scsi scan: peripheral device type" 1296 " of 31, no device added\n")); 1297 res = SCSI_SCAN_TARGET_PRESENT; 1298 goto out_free_result; 1299 } 1300 1301 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1302 if (res == SCSI_SCAN_LUN_PRESENT) { 1303 if (bflags & BLIST_KEY) { 1304 sdev->lockable = 0; 1305 scsi_unlock_floptical(sdev, result); 1306 } 1307 } 1308 1309 out_free_result: 1310 kfree(result); 1311 out_free_sdev: 1312 if (res == SCSI_SCAN_LUN_PRESENT) { 1313 if (sdevp) { 1314 if (scsi_device_get(sdev) == 0) { 1315 *sdevp = sdev; 1316 } else { 1317 __scsi_remove_device(sdev); 1318 res = SCSI_SCAN_NO_RESPONSE; 1319 } 1320 } 1321 } else 1322 __scsi_remove_device(sdev); 1323 out: 1324 return res; 1325 } 1326 1327 /** 1328 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1329 * @starget: pointer to target structure to scan 1330 * @bflags: black/white list flag for LUN 0 1331 * @scsi_level: Which version of the standard does this device adhere to 1332 * @rescan: passed to scsi_probe_add_lun() 1333 * 1334 * Description: 1335 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1336 * scanned) to some maximum lun until a LUN is found with no device 1337 * attached. Use the bflags to figure out any oddities. 1338 * 1339 * Modifies sdevscan->lun. 1340 **/ 1341 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1342 blist_flags_t bflags, int scsi_level, 1343 enum scsi_scan_mode rescan) 1344 { 1345 uint max_dev_lun; 1346 u64 sparse_lun, lun; 1347 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1348 1349 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1350 "scsi scan: Sequential scan\n")); 1351 1352 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1353 /* 1354 * If this device is known to support sparse multiple units, 1355 * override the other settings, and scan all of them. Normally, 1356 * SCSI-3 devices should be scanned via the REPORT LUNS. 1357 */ 1358 if (bflags & BLIST_SPARSELUN) { 1359 max_dev_lun = shost->max_lun; 1360 sparse_lun = 1; 1361 } else 1362 sparse_lun = 0; 1363 1364 /* 1365 * If less than SCSI_1_CCS, and no special lun scanning, stop 1366 * scanning; this matches 2.4 behaviour, but could just be a bug 1367 * (to continue scanning a SCSI_1_CCS device). 1368 * 1369 * This test is broken. We might not have any device on lun0 for 1370 * a sparselun device, and if that's the case then how would we 1371 * know the real scsi_level, eh? It might make sense to just not 1372 * scan any SCSI_1 device for non-0 luns, but that check would best 1373 * go into scsi_alloc_sdev() and just have it return null when asked 1374 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1375 * 1376 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1377 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1378 == 0)) 1379 return; 1380 */ 1381 /* 1382 * If this device is known to support multiple units, override 1383 * the other settings, and scan all of them. 1384 */ 1385 if (bflags & BLIST_FORCELUN) 1386 max_dev_lun = shost->max_lun; 1387 /* 1388 * REGAL CDC-4X: avoid hang after LUN 4 1389 */ 1390 if (bflags & BLIST_MAX5LUN) 1391 max_dev_lun = min(5U, max_dev_lun); 1392 /* 1393 * Do not scan SCSI-2 or lower device past LUN 7, unless 1394 * BLIST_LARGELUN. 1395 */ 1396 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1397 max_dev_lun = min(8U, max_dev_lun); 1398 else 1399 max_dev_lun = min(256U, max_dev_lun); 1400 1401 /* 1402 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1403 * until we reach the max, or no LUN is found and we are not 1404 * sparse_lun. 1405 */ 1406 for (lun = 1; lun < max_dev_lun; ++lun) 1407 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1408 NULL) != SCSI_SCAN_LUN_PRESENT) && 1409 !sparse_lun) 1410 return; 1411 } 1412 1413 /** 1414 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1415 * @starget: which target 1416 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1417 * @rescan: nonzero if we can skip code only needed on first scan 1418 * 1419 * Description: 1420 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1421 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1422 * 1423 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1424 * LUNs even if it's older than SCSI-3. 1425 * If BLIST_NOREPORTLUN is set, return 1 always. 1426 * If BLIST_NOLUN is set, return 0 always. 1427 * If starget->no_report_luns is set, return 1 always. 1428 * 1429 * Return: 1430 * 0: scan completed (or no memory, so further scanning is futile) 1431 * 1: could not scan with REPORT LUN 1432 **/ 1433 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1434 enum scsi_scan_mode rescan) 1435 { 1436 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1437 unsigned int length; 1438 u64 lun; 1439 unsigned int num_luns; 1440 int result; 1441 struct scsi_lun *lunp, *lun_data; 1442 struct scsi_device *sdev; 1443 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1444 struct scsi_failure failure_defs[] = { 1445 { 1446 .sense = UNIT_ATTENTION, 1447 .asc = SCMD_FAILURE_ASC_ANY, 1448 .ascq = SCMD_FAILURE_ASCQ_ANY, 1449 .result = SAM_STAT_CHECK_CONDITION, 1450 }, 1451 /* Fail all CCs except the UA above */ 1452 { 1453 .sense = SCMD_FAILURE_SENSE_ANY, 1454 .result = SAM_STAT_CHECK_CONDITION, 1455 }, 1456 /* Retry any other errors not listed above */ 1457 { 1458 .result = SCMD_FAILURE_RESULT_ANY, 1459 }, 1460 {} 1461 }; 1462 struct scsi_failures failures = { 1463 .total_allowed = 3, 1464 .failure_definitions = failure_defs, 1465 }; 1466 const struct scsi_exec_args exec_args = { 1467 .failures = &failures, 1468 }; 1469 int ret = 0; 1470 1471 /* 1472 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1473 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1474 * support more than 8 LUNs. 1475 * Don't attempt if the target doesn't support REPORT LUNS. 1476 */ 1477 if (bflags & BLIST_NOREPORTLUN) 1478 return 1; 1479 if (starget->scsi_level < SCSI_2 && 1480 starget->scsi_level != SCSI_UNKNOWN) 1481 return 1; 1482 if (starget->scsi_level < SCSI_3 && 1483 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1484 return 1; 1485 if (bflags & BLIST_NOLUN) 1486 return 0; 1487 if (starget->no_report_luns) 1488 return 1; 1489 1490 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1491 sdev = scsi_alloc_sdev(starget, 0, NULL); 1492 if (!sdev) 1493 return 0; 1494 if (scsi_device_get(sdev)) { 1495 __scsi_remove_device(sdev); 1496 return 0; 1497 } 1498 } 1499 1500 /* 1501 * Allocate enough to hold the header (the same size as one scsi_lun) 1502 * plus the number of luns we are requesting. 511 was the default 1503 * value of the now removed max_report_luns parameter. 1504 */ 1505 length = (511 + 1) * sizeof(struct scsi_lun); 1506 retry: 1507 lun_data = kmalloc(length, GFP_KERNEL); 1508 if (!lun_data) { 1509 printk(ALLOC_FAILURE_MSG, __func__); 1510 goto out; 1511 } 1512 1513 scsi_cmd[0] = REPORT_LUNS; 1514 1515 /* 1516 * bytes 1 - 5: reserved, set to zero. 1517 */ 1518 memset(&scsi_cmd[1], 0, 5); 1519 1520 /* 1521 * bytes 6 - 9: length of the command. 1522 */ 1523 put_unaligned_be32(length, &scsi_cmd[6]); 1524 1525 scsi_cmd[10] = 0; /* reserved */ 1526 scsi_cmd[11] = 0; /* control */ 1527 1528 /* 1529 * We can get a UNIT ATTENTION, for example a power on/reset, so 1530 * retry a few times (like sd.c does for TEST UNIT READY). 1531 * Experience shows some combinations of adapter/devices get at 1532 * least two power on/resets. 1533 * 1534 * Illegal requests (for devices that do not support REPORT LUNS) 1535 * should come through as a check condition, and will not generate 1536 * a retry. 1537 */ 1538 scsi_failures_reset_retries(&failures); 1539 1540 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1541 "scsi scan: Sending REPORT LUNS\n")); 1542 1543 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data, 1544 length, SCSI_REPORT_LUNS_TIMEOUT, 3, 1545 &exec_args); 1546 1547 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1548 "scsi scan: REPORT LUNS %s result 0x%x\n", 1549 result ? "failed" : "successful", result)); 1550 if (result) { 1551 /* 1552 * The device probably does not support a REPORT LUN command 1553 */ 1554 ret = 1; 1555 goto out_err; 1556 } 1557 1558 /* 1559 * Get the length from the first four bytes of lun_data. 1560 */ 1561 if (get_unaligned_be32(lun_data->scsi_lun) + 1562 sizeof(struct scsi_lun) > length) { 1563 length = get_unaligned_be32(lun_data->scsi_lun) + 1564 sizeof(struct scsi_lun); 1565 kfree(lun_data); 1566 goto retry; 1567 } 1568 length = get_unaligned_be32(lun_data->scsi_lun); 1569 1570 num_luns = (length / sizeof(struct scsi_lun)); 1571 1572 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1573 "scsi scan: REPORT LUN scan\n")); 1574 1575 /* 1576 * Scan the luns in lun_data. The entry at offset 0 is really 1577 * the header, so start at 1 and go up to and including num_luns. 1578 */ 1579 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1580 lun = scsilun_to_int(lunp); 1581 1582 if (lun > sdev->host->max_lun) { 1583 sdev_printk(KERN_WARNING, sdev, 1584 "lun%llu has a LUN larger than" 1585 " allowed by the host adapter\n", lun); 1586 } else { 1587 int res; 1588 1589 res = scsi_probe_and_add_lun(starget, 1590 lun, NULL, NULL, rescan, NULL); 1591 if (res == SCSI_SCAN_NO_RESPONSE) { 1592 /* 1593 * Got some results, but now none, abort. 1594 */ 1595 sdev_printk(KERN_ERR, sdev, 1596 "Unexpected response" 1597 " from lun %llu while scanning, scan" 1598 " aborted\n", (unsigned long long)lun); 1599 break; 1600 } 1601 } 1602 } 1603 1604 out_err: 1605 kfree(lun_data); 1606 out: 1607 if (scsi_device_created(sdev)) 1608 /* 1609 * the sdev we used didn't appear in the report luns scan 1610 */ 1611 __scsi_remove_device(sdev); 1612 scsi_device_put(sdev); 1613 return ret; 1614 } 1615 1616 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1617 uint id, u64 lun, void *hostdata) 1618 { 1619 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1620 struct device *parent = &shost->shost_gendev; 1621 struct scsi_target *starget; 1622 1623 if (strncmp(scsi_scan_type, "none", 4) == 0) 1624 return ERR_PTR(-ENODEV); 1625 1626 starget = scsi_alloc_target(parent, channel, id); 1627 if (!starget) 1628 return ERR_PTR(-ENOMEM); 1629 scsi_autopm_get_target(starget); 1630 1631 mutex_lock(&shost->scan_mutex); 1632 if (!shost->async_scan) 1633 scsi_complete_async_scans(); 1634 1635 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1636 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1637 SCSI_SCAN_RESCAN, hostdata); 1638 scsi_autopm_put_host(shost); 1639 } 1640 mutex_unlock(&shost->scan_mutex); 1641 scsi_autopm_put_target(starget); 1642 /* 1643 * paired with scsi_alloc_target(). Target will be destroyed unless 1644 * scsi_probe_and_add_lun made an underlying device visible 1645 */ 1646 scsi_target_reap(starget); 1647 put_device(&starget->dev); 1648 1649 return sdev; 1650 } 1651 EXPORT_SYMBOL(__scsi_add_device); 1652 1653 /** 1654 * scsi_add_device - creates a new SCSI (LU) instance 1655 * @host: the &Scsi_Host instance where the device is located 1656 * @channel: target channel number (rarely other than %0) 1657 * @target: target id number 1658 * @lun: LUN of target device 1659 * 1660 * Probe for a specific LUN and add it if found. 1661 * 1662 * Notes: This call is usually performed internally during a SCSI 1663 * bus scan when an HBA is added (i.e. scsi_scan_host()). So it 1664 * should only be called if the HBA becomes aware of a new SCSI 1665 * device (LU) after scsi_scan_host() has completed. If successful 1666 * this call can lead to sdev_init() and sdev_configure() callbacks 1667 * into the LLD. 1668 * 1669 * Return: %0 on success or negative error code on failure 1670 */ 1671 int scsi_add_device(struct Scsi_Host *host, uint channel, 1672 uint target, u64 lun) 1673 { 1674 struct scsi_device *sdev = 1675 __scsi_add_device(host, channel, target, lun, NULL); 1676 if (IS_ERR(sdev)) 1677 return PTR_ERR(sdev); 1678 1679 scsi_device_put(sdev); 1680 return 0; 1681 } 1682 EXPORT_SYMBOL(scsi_add_device); 1683 1684 int scsi_resume_device(struct scsi_device *sdev) 1685 { 1686 struct device *dev = &sdev->sdev_gendev; 1687 int ret = 0; 1688 1689 device_lock(dev); 1690 1691 /* 1692 * Bail out if the device or its queue are not running. Otherwise, 1693 * the rescan may block waiting for commands to be executed, with us 1694 * holding the device lock. This can result in a potential deadlock 1695 * in the power management core code when system resume is on-going. 1696 */ 1697 if (sdev->sdev_state != SDEV_RUNNING || 1698 blk_queue_pm_only(sdev->request_queue)) { 1699 ret = -EWOULDBLOCK; 1700 goto unlock; 1701 } 1702 1703 if (dev->driver && try_module_get(dev->driver->owner)) { 1704 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1705 1706 if (drv->resume) 1707 ret = drv->resume(dev); 1708 module_put(dev->driver->owner); 1709 } 1710 1711 unlock: 1712 device_unlock(dev); 1713 1714 return ret; 1715 } 1716 EXPORT_SYMBOL(scsi_resume_device); 1717 1718 int scsi_rescan_device(struct scsi_device *sdev) 1719 { 1720 struct device *dev = &sdev->sdev_gendev; 1721 int ret = 0; 1722 1723 device_lock(dev); 1724 1725 /* 1726 * Bail out if the device or its queue are not running. Otherwise, 1727 * the rescan may block waiting for commands to be executed, with us 1728 * holding the device lock. This can result in a potential deadlock 1729 * in the power management core code when system resume is on-going. 1730 */ 1731 if (sdev->sdev_state != SDEV_RUNNING || 1732 blk_queue_pm_only(sdev->request_queue)) { 1733 ret = -EWOULDBLOCK; 1734 goto unlock; 1735 } 1736 1737 scsi_attach_vpd(sdev); 1738 scsi_cdl_check(sdev); 1739 1740 if (sdev->handler && sdev->handler->rescan) 1741 sdev->handler->rescan(sdev); 1742 1743 if (dev->driver && try_module_get(dev->driver->owner)) { 1744 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1745 1746 if (drv->rescan) 1747 drv->rescan(dev); 1748 module_put(dev->driver->owner); 1749 } 1750 1751 unlock: 1752 device_unlock(dev); 1753 1754 return ret; 1755 } 1756 EXPORT_SYMBOL(scsi_rescan_device); 1757 1758 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1759 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1760 { 1761 struct Scsi_Host *shost = dev_to_shost(parent); 1762 blist_flags_t bflags = 0; 1763 int res; 1764 struct scsi_target *starget; 1765 1766 if (shost->this_id == id) 1767 /* 1768 * Don't scan the host adapter 1769 */ 1770 return; 1771 1772 starget = scsi_alloc_target(parent, channel, id); 1773 if (!starget) 1774 return; 1775 scsi_autopm_get_target(starget); 1776 1777 if (lun != SCAN_WILD_CARD) { 1778 /* 1779 * Scan for a specific host/chan/id/lun. 1780 */ 1781 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1782 goto out_reap; 1783 } 1784 1785 /* 1786 * Scan LUN 0, if there is some response, scan further. Ideally, we 1787 * would not configure LUN 0 until all LUNs are scanned. 1788 */ 1789 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1790 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1791 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1792 /* 1793 * The REPORT LUN did not scan the target, 1794 * do a sequential scan. 1795 */ 1796 scsi_sequential_lun_scan(starget, bflags, 1797 starget->scsi_level, rescan); 1798 } 1799 1800 out_reap: 1801 scsi_autopm_put_target(starget); 1802 /* 1803 * paired with scsi_alloc_target(): determine if the target has 1804 * any children at all and if not, nuke it 1805 */ 1806 scsi_target_reap(starget); 1807 1808 put_device(&starget->dev); 1809 } 1810 1811 /** 1812 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1813 * @parent: host to scan 1814 * @channel: channel to scan 1815 * @id: target id to scan 1816 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1817 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1818 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1819 * and SCSI_SCAN_MANUAL to force scanning even if 1820 * 'scan=manual' is set. 1821 * 1822 * Description: 1823 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1824 * and possibly all LUNs on the target id. 1825 * 1826 * First try a REPORT LUN scan, if that does not scan the target, do a 1827 * sequential scan of LUNs on the target id. 1828 **/ 1829 void scsi_scan_target(struct device *parent, unsigned int channel, 1830 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1831 { 1832 struct Scsi_Host *shost = dev_to_shost(parent); 1833 1834 if (strncmp(scsi_scan_type, "none", 4) == 0) 1835 return; 1836 1837 if (rescan != SCSI_SCAN_MANUAL && 1838 strncmp(scsi_scan_type, "manual", 6) == 0) 1839 return; 1840 1841 mutex_lock(&shost->scan_mutex); 1842 if (!shost->async_scan) 1843 scsi_complete_async_scans(); 1844 1845 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1846 __scsi_scan_target(parent, channel, id, lun, rescan); 1847 scsi_autopm_put_host(shost); 1848 } 1849 mutex_unlock(&shost->scan_mutex); 1850 } 1851 EXPORT_SYMBOL(scsi_scan_target); 1852 1853 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1854 unsigned int id, u64 lun, 1855 enum scsi_scan_mode rescan) 1856 { 1857 uint order_id; 1858 1859 if (id == SCAN_WILD_CARD) 1860 for (id = 0; id < shost->max_id; ++id) { 1861 /* 1862 * XXX adapter drivers when possible (FCP, iSCSI) 1863 * could modify max_id to match the current max, 1864 * not the absolute max. 1865 * 1866 * XXX add a shost id iterator, so for example, 1867 * the FC ID can be the same as a target id 1868 * without a huge overhead of sparse id's. 1869 */ 1870 if (shost->reverse_ordering) 1871 /* 1872 * Scan from high to low id. 1873 */ 1874 order_id = shost->max_id - id - 1; 1875 else 1876 order_id = id; 1877 __scsi_scan_target(&shost->shost_gendev, channel, 1878 order_id, lun, rescan); 1879 } 1880 else 1881 __scsi_scan_target(&shost->shost_gendev, channel, 1882 id, lun, rescan); 1883 } 1884 1885 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1886 unsigned int id, u64 lun, 1887 enum scsi_scan_mode rescan) 1888 { 1889 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1890 "%s: <%u:%u:%llu>\n", 1891 __func__, channel, id, lun)); 1892 1893 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1894 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1895 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1896 return -EINVAL; 1897 1898 mutex_lock(&shost->scan_mutex); 1899 if (!shost->async_scan) 1900 scsi_complete_async_scans(); 1901 1902 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1903 if (channel == SCAN_WILD_CARD) 1904 for (channel = 0; channel <= shost->max_channel; 1905 channel++) 1906 scsi_scan_channel(shost, channel, id, lun, 1907 rescan); 1908 else 1909 scsi_scan_channel(shost, channel, id, lun, rescan); 1910 scsi_autopm_put_host(shost); 1911 } 1912 mutex_unlock(&shost->scan_mutex); 1913 1914 return 0; 1915 } 1916 EXPORT_SYMBOL(scsi_scan_host_selected); 1917 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1918 { 1919 struct scsi_device *sdev; 1920 shost_for_each_device(sdev, shost) { 1921 /* target removed before the device could be added */ 1922 if (sdev->sdev_state == SDEV_DEL) 1923 continue; 1924 /* If device is already visible, skip adding it to sysfs */ 1925 if (sdev->is_visible) 1926 continue; 1927 if (!scsi_host_scan_allowed(shost) || 1928 scsi_sysfs_add_sdev(sdev) != 0) 1929 __scsi_remove_device(sdev); 1930 } 1931 } 1932 1933 /** 1934 * scsi_prep_async_scan - prepare for an async scan 1935 * @shost: the host which will be scanned 1936 * Returns: a cookie to be passed to scsi_finish_async_scan() 1937 * 1938 * Tells the midlayer this host is going to do an asynchronous scan. 1939 * It reserves the host's position in the scanning list and ensures 1940 * that other asynchronous scans started after this one won't affect the 1941 * ordering of the discovered devices. 1942 */ 1943 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1944 { 1945 struct async_scan_data *data = NULL; 1946 unsigned long flags; 1947 1948 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1949 return NULL; 1950 1951 mutex_lock(&shost->scan_mutex); 1952 if (shost->async_scan) { 1953 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1954 goto err; 1955 } 1956 1957 data = kmalloc(sizeof(*data), GFP_KERNEL); 1958 if (!data) 1959 goto err; 1960 data->shost = scsi_host_get(shost); 1961 if (!data->shost) 1962 goto err; 1963 init_completion(&data->prev_finished); 1964 1965 spin_lock_irqsave(shost->host_lock, flags); 1966 shost->async_scan = 1; 1967 spin_unlock_irqrestore(shost->host_lock, flags); 1968 mutex_unlock(&shost->scan_mutex); 1969 1970 spin_lock(&async_scan_lock); 1971 if (list_empty(&scanning_hosts)) 1972 complete(&data->prev_finished); 1973 list_add_tail(&data->list, &scanning_hosts); 1974 spin_unlock(&async_scan_lock); 1975 1976 return data; 1977 1978 err: 1979 mutex_unlock(&shost->scan_mutex); 1980 kfree(data); 1981 return NULL; 1982 } 1983 1984 /** 1985 * scsi_finish_async_scan - asynchronous scan has finished 1986 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1987 * 1988 * All the devices currently attached to this host have been found. 1989 * This function announces all the devices it has found to the rest 1990 * of the system. 1991 */ 1992 static void scsi_finish_async_scan(struct async_scan_data *data) 1993 { 1994 struct Scsi_Host *shost; 1995 unsigned long flags; 1996 1997 if (!data) 1998 return; 1999 2000 shost = data->shost; 2001 2002 mutex_lock(&shost->scan_mutex); 2003 2004 if (!shost->async_scan) { 2005 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 2006 dump_stack(); 2007 mutex_unlock(&shost->scan_mutex); 2008 return; 2009 } 2010 2011 wait_for_completion(&data->prev_finished); 2012 2013 scsi_sysfs_add_devices(shost); 2014 2015 spin_lock_irqsave(shost->host_lock, flags); 2016 shost->async_scan = 0; 2017 spin_unlock_irqrestore(shost->host_lock, flags); 2018 2019 mutex_unlock(&shost->scan_mutex); 2020 2021 spin_lock(&async_scan_lock); 2022 list_del(&data->list); 2023 if (!list_empty(&scanning_hosts)) { 2024 struct async_scan_data *next = list_entry(scanning_hosts.next, 2025 struct async_scan_data, list); 2026 complete(&next->prev_finished); 2027 } 2028 spin_unlock(&async_scan_lock); 2029 2030 scsi_autopm_put_host(shost); 2031 scsi_host_put(shost); 2032 kfree(data); 2033 } 2034 2035 static void do_scsi_scan_host(struct Scsi_Host *shost) 2036 { 2037 if (shost->hostt->scan_finished) { 2038 unsigned long start = jiffies; 2039 if (shost->hostt->scan_start) 2040 shost->hostt->scan_start(shost); 2041 2042 while (!shost->hostt->scan_finished(shost, jiffies - start)) 2043 msleep(10); 2044 } else { 2045 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 2046 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 2047 } 2048 } 2049 2050 static void do_scan_async(void *_data, async_cookie_t c) 2051 { 2052 struct async_scan_data *data = _data; 2053 struct Scsi_Host *shost = data->shost; 2054 2055 do_scsi_scan_host(shost); 2056 scsi_finish_async_scan(data); 2057 } 2058 2059 /** 2060 * scsi_scan_host - scan the given adapter 2061 * @shost: adapter to scan 2062 * 2063 * Notes: Should be called after scsi_add_host() 2064 **/ 2065 void scsi_scan_host(struct Scsi_Host *shost) 2066 { 2067 struct async_scan_data *data; 2068 2069 if (strncmp(scsi_scan_type, "none", 4) == 0 || 2070 strncmp(scsi_scan_type, "manual", 6) == 0) 2071 return; 2072 if (scsi_autopm_get_host(shost) < 0) 2073 return; 2074 2075 data = scsi_prep_async_scan(shost); 2076 if (!data) { 2077 do_scsi_scan_host(shost); 2078 scsi_autopm_put_host(shost); 2079 return; 2080 } 2081 2082 /* register with the async subsystem so wait_for_device_probe() 2083 * will flush this work 2084 */ 2085 async_schedule(do_scan_async, data); 2086 2087 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 2088 } 2089 EXPORT_SYMBOL(scsi_scan_host); 2090 2091 void scsi_forget_host(struct Scsi_Host *shost) 2092 { 2093 struct scsi_device *sdev; 2094 unsigned long flags; 2095 2096 restart: 2097 spin_lock_irqsave(shost->host_lock, flags); 2098 list_for_each_entry(sdev, &shost->__devices, siblings) { 2099 if (scsi_device_is_pseudo_dev(sdev) || 2100 sdev->sdev_state == SDEV_DEL) 2101 continue; 2102 spin_unlock_irqrestore(shost->host_lock, flags); 2103 __scsi_remove_device(sdev); 2104 goto restart; 2105 } 2106 spin_unlock_irqrestore(shost->host_lock, flags); 2107 2108 /* 2109 * Remove the pseudo device last since it may be needed during removal 2110 * of other SCSI devices. 2111 */ 2112 if (shost->pseudo_sdev) 2113 __scsi_remove_device(shost->pseudo_sdev); 2114 } 2115 2116 /** 2117 * scsi_get_pseudo_sdev() - Attach a pseudo SCSI device to a SCSI host 2118 * @shost: Host that needs a pseudo SCSI device 2119 * 2120 * Lock status: None assumed. 2121 * 2122 * Returns: The scsi_device or NULL 2123 * 2124 * Notes: 2125 * Attach a single scsi_device to the Scsi_Host. The primary aim for this 2126 * device is to serve as a container from which SCSI commands can be 2127 * allocated. Each SCSI command will carry a command tag allocated by the 2128 * block layer. These SCSI commands can be used by the LLDD to send 2129 * internal or passthrough commands without having to manage tag allocation 2130 * inside the LLDD. 2131 */ 2132 struct scsi_device *scsi_get_pseudo_sdev(struct Scsi_Host *shost) 2133 { 2134 struct scsi_device *sdev = NULL; 2135 struct scsi_target *starget; 2136 2137 guard(mutex)(&shost->scan_mutex); 2138 2139 if (!scsi_host_scan_allowed(shost)) 2140 goto out; 2141 2142 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->max_id); 2143 if (!starget) 2144 goto out; 2145 2146 sdev = scsi_alloc_sdev(starget, U64_MAX, NULL); 2147 if (!sdev) { 2148 scsi_target_reap(starget); 2149 goto put_target; 2150 } 2151 2152 sdev->borken = 0; 2153 2154 put_target: 2155 /* See also the get_device(dev) call in scsi_alloc_target(). */ 2156 put_device(&starget->dev); 2157 2158 out: 2159 return sdev; 2160 } 2161