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 kref_put(&sdev->host->tagset_refcnt, scsi_mq_free_tags); 365 put_device(&starget->dev); 366 kfree(sdev); 367 goto out; 368 } 369 370 scsi_change_queue_depth(sdev, depth); 371 372 if (shost->hostt->sdev_init) { 373 ret = shost->hostt->sdev_init(sdev); 374 if (ret) { 375 /* 376 * if LLDD reports slave not present, don't clutter 377 * console with alloc failure messages 378 */ 379 if (ret == -ENXIO) 380 display_failure_msg = 0; 381 goto out_device_destroy; 382 } 383 } 384 385 return sdev; 386 387 out_device_destroy: 388 __scsi_remove_device(sdev); 389 out: 390 if (display_failure_msg) 391 printk(ALLOC_FAILURE_MSG, __func__); 392 return NULL; 393 } 394 395 static void scsi_target_destroy(struct scsi_target *starget) 396 { 397 struct device *dev = &starget->dev; 398 struct Scsi_Host *shost = dev_to_shost(dev->parent); 399 unsigned long flags; 400 401 BUG_ON(starget->state == STARGET_DEL); 402 starget->state = STARGET_DEL; 403 transport_destroy_device(dev); 404 spin_lock_irqsave(shost->host_lock, flags); 405 if (shost->hostt->target_destroy) 406 shost->hostt->target_destroy(starget); 407 list_del_init(&starget->siblings); 408 spin_unlock_irqrestore(shost->host_lock, flags); 409 put_device(dev); 410 } 411 412 static void scsi_target_dev_release(struct device *dev) 413 { 414 struct device *parent = dev->parent; 415 struct scsi_target *starget = to_scsi_target(dev); 416 417 kfree(starget); 418 put_device(parent); 419 } 420 421 static const struct device_type scsi_target_type = { 422 .name = "scsi_target", 423 .release = scsi_target_dev_release, 424 }; 425 426 int scsi_is_target_device(const struct device *dev) 427 { 428 return dev->type == &scsi_target_type; 429 } 430 EXPORT_SYMBOL(scsi_is_target_device); 431 432 static struct scsi_target *__scsi_find_target(struct device *parent, 433 int channel, uint id) 434 { 435 struct scsi_target *starget, *found_starget = NULL; 436 struct Scsi_Host *shost = dev_to_shost(parent); 437 /* 438 * Search for an existing target for this sdev. 439 */ 440 list_for_each_entry(starget, &shost->__targets, siblings) { 441 if (starget->id == id && 442 starget->channel == channel) { 443 found_starget = starget; 444 break; 445 } 446 } 447 if (found_starget) 448 get_device(&found_starget->dev); 449 450 return found_starget; 451 } 452 453 /** 454 * scsi_target_reap_ref_release - remove target from visibility 455 * @kref: the reap_ref in the target being released 456 * 457 * Called on last put of reap_ref, which is the indication that no device 458 * under this target is visible anymore, so render the target invisible in 459 * sysfs. Note: we have to be in user context here because the target reaps 460 * should be done in places where the scsi device visibility is being removed. 461 */ 462 static void scsi_target_reap_ref_release(struct kref *kref) 463 { 464 struct scsi_target *starget 465 = container_of(kref, struct scsi_target, reap_ref); 466 467 /* 468 * if we get here and the target is still in a CREATED state that 469 * means it was allocated but never made visible (because a scan 470 * turned up no LUNs), so don't call device_del() on it. 471 */ 472 if ((starget->state != STARGET_CREATED) && 473 (starget->state != STARGET_CREATED_REMOVE)) { 474 transport_remove_device(&starget->dev); 475 device_del(&starget->dev); 476 } 477 scsi_target_destroy(starget); 478 } 479 480 static void scsi_target_reap_ref_put(struct scsi_target *starget) 481 { 482 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 483 } 484 485 /** 486 * scsi_alloc_target - allocate a new or find an existing target 487 * @parent: parent of the target (need not be a scsi host) 488 * @channel: target channel number (zero if no channels) 489 * @id: target id number 490 * 491 * Return an existing target if one exists, provided it hasn't already 492 * gone into STARGET_DEL state, otherwise allocate a new target. 493 * 494 * The target is returned with an incremented reference, so the caller 495 * is responsible for both reaping and doing a last put 496 */ 497 static struct scsi_target *scsi_alloc_target(struct device *parent, 498 int channel, uint id) 499 { 500 struct Scsi_Host *shost = dev_to_shost(parent); 501 struct device *dev = NULL; 502 unsigned long flags; 503 const int size = sizeof(struct scsi_target) 504 + shost->transportt->target_size; 505 struct scsi_target *starget; 506 struct scsi_target *found_target; 507 int error, ref_got; 508 509 starget = kzalloc(size, GFP_KERNEL); 510 if (!starget) { 511 printk(KERN_ERR "%s: allocation failure\n", __func__); 512 return NULL; 513 } 514 dev = &starget->dev; 515 device_initialize(dev); 516 kref_init(&starget->reap_ref); 517 dev->parent = get_device(parent); 518 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 519 dev->bus = &scsi_bus_type; 520 dev->type = &scsi_target_type; 521 scsi_enable_async_suspend(dev); 522 starget->id = id; 523 starget->channel = channel; 524 starget->can_queue = 0; 525 INIT_LIST_HEAD(&starget->siblings); 526 INIT_LIST_HEAD(&starget->devices); 527 starget->state = STARGET_CREATED; 528 starget->scsi_level = SCSI_2; 529 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 530 retry: 531 spin_lock_irqsave(shost->host_lock, flags); 532 533 found_target = __scsi_find_target(parent, channel, id); 534 if (found_target) 535 goto found; 536 537 list_add_tail(&starget->siblings, &shost->__targets); 538 spin_unlock_irqrestore(shost->host_lock, flags); 539 /* allocate and add */ 540 transport_setup_device(dev); 541 if (shost->hostt->target_alloc) { 542 error = shost->hostt->target_alloc(starget); 543 544 if(error) { 545 if (error != -ENXIO) 546 dev_err(dev, "target allocation failed, error %d\n", error); 547 /* don't want scsi_target_reap to do the final 548 * put because it will be under the host lock */ 549 scsi_target_destroy(starget); 550 return NULL; 551 } 552 } 553 get_device(dev); 554 555 return starget; 556 557 found: 558 /* 559 * release routine already fired if kref is zero, so if we can still 560 * take the reference, the target must be alive. If we can't, it must 561 * be dying and we need to wait for a new target 562 */ 563 ref_got = kref_get_unless_zero(&found_target->reap_ref); 564 565 spin_unlock_irqrestore(shost->host_lock, flags); 566 if (ref_got) { 567 put_device(dev); 568 return found_target; 569 } 570 /* 571 * Unfortunately, we found a dying target; need to wait until it's 572 * dead before we can get a new one. There is an anomaly here. We 573 * *should* call scsi_target_reap() to balance the kref_get() of the 574 * reap_ref above. However, since the target being released, it's 575 * already invisible and the reap_ref is irrelevant. If we call 576 * scsi_target_reap() we might spuriously do another device_del() on 577 * an already invisible target. 578 */ 579 put_device(&found_target->dev); 580 /* 581 * length of time is irrelevant here, we just want to yield the CPU 582 * for a tick to avoid busy waiting for the target to die. 583 */ 584 msleep(1); 585 goto retry; 586 } 587 588 /** 589 * scsi_target_reap - check to see if target is in use and destroy if not 590 * @starget: target to be checked 591 * 592 * This is used after removing a LUN or doing a last put of the target 593 * it checks atomically that nothing is using the target and removes 594 * it if so. 595 */ 596 void scsi_target_reap(struct scsi_target *starget) 597 { 598 /* 599 * serious problem if this triggers: STARGET_DEL is only set in the if 600 * the reap_ref drops to zero, so we're trying to do another final put 601 * on an already released kref 602 */ 603 BUG_ON(starget->state == STARGET_DEL); 604 scsi_target_reap_ref_put(starget); 605 } 606 607 /** 608 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 609 * INQUIRY result string 610 * @s: INQUIRY result string to sanitize 611 * @len: length of the string 612 * 613 * Description: 614 * The SCSI spec says that INQUIRY vendor, product, and revision 615 * strings must consist entirely of graphic ASCII characters, 616 * padded on the right with spaces. Since not all devices obey 617 * this rule, we will replace non-graphic or non-ASCII characters 618 * with spaces. Exception: a NUL character is interpreted as a 619 * string terminator, so all the following characters are set to 620 * spaces. 621 **/ 622 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 623 { 624 int terminated = 0; 625 626 for (; len > 0; (--len, ++s)) { 627 if (*s == 0) 628 terminated = 1; 629 if (terminated || *s < 0x20 || *s > 0x7e) 630 *s = ' '; 631 } 632 } 633 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 634 635 636 /** 637 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 638 * @sdev: scsi_device to probe 639 * @inq_result: area to store the INQUIRY result 640 * @result_len: len of inq_result 641 * @bflags: store any bflags found here 642 * 643 * Description: 644 * Probe the lun associated with @req using a standard SCSI INQUIRY; 645 * 646 * If the INQUIRY is successful, zero is returned and the 647 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 648 * are copied to the scsi_device any flags value is stored in *@bflags. 649 **/ 650 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 651 int result_len, blist_flags_t *bflags) 652 { 653 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 654 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 655 int response_len = 0; 656 int pass, count, result, resid; 657 struct scsi_failure failure_defs[] = { 658 /* 659 * not-ready to ready transition [asc/ascq=0x28/0x0] or 660 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY 661 * should not yield UNIT_ATTENTION but many buggy devices do 662 * so anyway. 663 */ 664 { 665 .sense = UNIT_ATTENTION, 666 .asc = 0x28, 667 .result = SAM_STAT_CHECK_CONDITION, 668 }, 669 { 670 .sense = UNIT_ATTENTION, 671 .asc = 0x29, 672 .result = SAM_STAT_CHECK_CONDITION, 673 }, 674 { 675 .allowed = 1, 676 .result = DID_TIME_OUT << 16, 677 }, 678 {} 679 }; 680 struct scsi_failures failures = { 681 .total_allowed = 3, 682 .failure_definitions = failure_defs, 683 }; 684 const struct scsi_exec_args exec_args = { 685 .resid = &resid, 686 .failures = &failures, 687 }; 688 689 *bflags = 0; 690 691 /* Perform up to 3 passes. The first pass uses a conservative 692 * transfer length of 36 unless sdev->inquiry_len specifies a 693 * different value. */ 694 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 695 try_inquiry_len = first_inquiry_len; 696 pass = 1; 697 698 next_pass: 699 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 700 "scsi scan: INQUIRY pass %d length %d\n", 701 pass, try_inquiry_len)); 702 703 /* Each pass gets up to three chances to ignore Unit Attention */ 704 scsi_failures_reset_retries(&failures); 705 706 for (count = 0; count < 3; ++count) { 707 memset(scsi_cmd, 0, 6); 708 scsi_cmd[0] = INQUIRY; 709 scsi_cmd[4] = (unsigned char) try_inquiry_len; 710 711 memset(inq_result, 0, try_inquiry_len); 712 713 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 714 inq_result, try_inquiry_len, 715 HZ / 2 + HZ * scsi_inq_timeout, 3, 716 &exec_args); 717 718 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 719 "scsi scan: INQUIRY %s with code 0x%x\n", 720 result ? "failed" : "successful", result)); 721 722 if (result == 0) { 723 /* 724 * if nothing was transferred, we try 725 * again. It's a workaround for some USB 726 * devices. 727 */ 728 if (resid == try_inquiry_len) 729 continue; 730 } 731 break; 732 } 733 734 if (result == 0) { 735 scsi_sanitize_inquiry_string(&inq_result[8], 8); 736 scsi_sanitize_inquiry_string(&inq_result[16], 16); 737 scsi_sanitize_inquiry_string(&inq_result[32], 4); 738 739 response_len = inq_result[4] + 5; 740 if (response_len > 255) 741 response_len = first_inquiry_len; /* sanity */ 742 743 /* 744 * Get any flags for this device. 745 * 746 * XXX add a bflags to scsi_device, and replace the 747 * corresponding bit fields in scsi_device, so bflags 748 * need not be passed as an argument. 749 */ 750 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 751 &inq_result[16]); 752 753 /* When the first pass succeeds we gain information about 754 * what larger transfer lengths might work. */ 755 if (pass == 1) { 756 if (BLIST_INQUIRY_36 & *bflags) 757 next_inquiry_len = 36; 758 /* 759 * LLD specified a maximum sdev->inquiry_len 760 * but device claims it has more data. Capping 761 * the length only makes sense for legacy 762 * devices. If a device supports SPC-4 (2014) 763 * or newer, assume that it is safe to ask for 764 * as much as the device says it supports. 765 */ 766 else if (sdev->inquiry_len && 767 response_len > sdev->inquiry_len && 768 (inq_result[2] & 0x7) < 6) /* SPC-4 */ 769 next_inquiry_len = sdev->inquiry_len; 770 else 771 next_inquiry_len = response_len; 772 773 /* If more data is available perform the second pass */ 774 if (next_inquiry_len > try_inquiry_len) { 775 try_inquiry_len = next_inquiry_len; 776 pass = 2; 777 goto next_pass; 778 } 779 } 780 781 } else if (pass == 2) { 782 sdev_printk(KERN_INFO, sdev, 783 "scsi scan: %d byte inquiry failed. " 784 "Consider BLIST_INQUIRY_36 for this device\n", 785 try_inquiry_len); 786 787 /* If this pass failed, the third pass goes back and transfers 788 * the same amount as we successfully got in the first pass. */ 789 try_inquiry_len = first_inquiry_len; 790 pass = 3; 791 goto next_pass; 792 } 793 794 /* If the last transfer attempt got an error, assume the 795 * peripheral doesn't exist or is dead. */ 796 if (result) 797 return -EIO; 798 799 /* Don't report any more data than the device says is valid */ 800 sdev->inquiry_len = min(try_inquiry_len, response_len); 801 802 /* 803 * XXX Abort if the response length is less than 36? If less than 804 * 32, the lookup of the device flags (above) could be invalid, 805 * and it would be possible to take an incorrect action - we do 806 * not want to hang because of a short INQUIRY. On the flip side, 807 * if the device is spun down or becoming ready (and so it gives a 808 * short INQUIRY), an abort here prevents any further use of the 809 * device, including spin up. 810 * 811 * On the whole, the best approach seems to be to assume the first 812 * 36 bytes are valid no matter what the device says. That's 813 * better than copying < 36 bytes to the inquiry-result buffer 814 * and displaying garbage for the Vendor, Product, or Revision 815 * strings. 816 */ 817 if (sdev->inquiry_len < 36) { 818 if (!sdev->host->short_inquiry) { 819 shost_printk(KERN_INFO, sdev->host, 820 "scsi scan: INQUIRY result too short (%d)," 821 " using 36\n", sdev->inquiry_len); 822 sdev->host->short_inquiry = 1; 823 } 824 sdev->inquiry_len = 36; 825 } 826 827 /* 828 * Related to the above issue: 829 * 830 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 831 * and if not ready, sent a START_STOP to start (maybe spin up) and 832 * then send the INQUIRY again, since the INQUIRY can change after 833 * a device is initialized. 834 * 835 * Ideally, start a device if explicitly asked to do so. This 836 * assumes that a device is spun up on power on, spun down on 837 * request, and then spun up on request. 838 */ 839 840 /* 841 * The scanning code needs to know the scsi_level, even if no 842 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 843 * non-zero LUNs can be scanned. 844 */ 845 sdev->scsi_level = inq_result[2] & 0x0f; 846 if (sdev->scsi_level >= 2 || 847 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 848 sdev->scsi_level++; 849 sdev->sdev_target->scsi_level = sdev->scsi_level; 850 851 /* 852 * If SCSI-2 or lower, and if the transport requires it, 853 * store the LUN value in CDB[1]. 854 */ 855 sdev->lun_in_cdb = 0; 856 if (sdev->scsi_level <= SCSI_2 && 857 sdev->scsi_level != SCSI_UNKNOWN && 858 !sdev->host->no_scsi2_lun_in_cdb) 859 sdev->lun_in_cdb = 1; 860 861 return 0; 862 } 863 864 /** 865 * scsi_add_lun - allocate and fully initialze a scsi_device 866 * @sdev: holds information to be stored in the new scsi_device 867 * @inq_result: holds the result of a previous INQUIRY to the LUN 868 * @bflags: black/white list flag 869 * @async: 1 if this device is being scanned asynchronously 870 * 871 * Description: 872 * Initialize the scsi_device @sdev. Optionally set fields based 873 * on values in *@bflags. 874 * 875 * Return: 876 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 877 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 878 **/ 879 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 880 blist_flags_t *bflags, int async) 881 { 882 const struct scsi_host_template *hostt = sdev->host->hostt; 883 struct queue_limits lim; 884 int ret; 885 886 /* 887 * XXX do not save the inquiry, since it can change underneath us, 888 * save just vendor/model/rev. 889 * 890 * Rather than save it and have an ioctl that retrieves the saved 891 * value, have an ioctl that executes the same INQUIRY code used 892 * in scsi_probe_lun, let user level programs doing INQUIRY 893 * scanning run at their own risk, or supply a user level program 894 * that can correctly scan. 895 */ 896 897 /* 898 * Copy at least 36 bytes of INQUIRY data, so that we don't 899 * dereference unallocated memory when accessing the Vendor, 900 * Product, and Revision strings. Badly behaved devices may set 901 * the INQUIRY Additional Length byte to a small value, indicating 902 * these strings are invalid, but often they contain plausible data 903 * nonetheless. It doesn't matter if the device sent < 36 bytes 904 * total, since scsi_probe_lun() initializes inq_result with 0s. 905 */ 906 sdev->inquiry = kmemdup(inq_result, 907 max_t(size_t, sdev->inquiry_len, 36), 908 GFP_KERNEL); 909 if (sdev->inquiry == NULL) 910 return SCSI_SCAN_NO_RESPONSE; 911 912 sdev->vendor = (char *) (sdev->inquiry + 8); 913 sdev->model = (char *) (sdev->inquiry + 16); 914 sdev->rev = (char *) (sdev->inquiry + 32); 915 916 sdev->is_ata = strncmp(sdev->vendor, "ATA ", 8) == 0; 917 if (sdev->is_ata) { 918 /* 919 * sata emulation layer device. This is a hack to work around 920 * the SATL power management specifications which state that 921 * when the SATL detects the device has gone into standby 922 * mode, it shall respond with NOT READY. 923 */ 924 sdev->allow_restart = 1; 925 } 926 927 if (*bflags & BLIST_ISROM) { 928 sdev->type = TYPE_ROM; 929 sdev->removable = 1; 930 } else { 931 sdev->type = (inq_result[0] & 0x1f); 932 sdev->removable = (inq_result[1] & 0x80) >> 7; 933 934 /* 935 * some devices may respond with wrong type for 936 * well-known logical units. Force well-known type 937 * to enumerate them correctly. 938 */ 939 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 940 sdev_printk(KERN_WARNING, sdev, 941 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 942 __func__, sdev->type, (unsigned int)sdev->lun); 943 sdev->type = TYPE_WLUN; 944 } 945 946 } 947 948 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 949 /* RBC and MMC devices can return SCSI-3 compliance and yet 950 * still not support REPORT LUNS, so make them act as 951 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 952 * specifically set */ 953 if ((*bflags & BLIST_REPORTLUN2) == 0) 954 *bflags |= BLIST_NOREPORTLUN; 955 } 956 957 /* 958 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 959 * spec says: The device server is capable of supporting the 960 * specified peripheral device type on this logical unit. However, 961 * the physical device is not currently connected to this logical 962 * unit. 963 * 964 * The above is vague, as it implies that we could treat 001 and 965 * 011 the same. Stay compatible with previous code, and create a 966 * scsi_device for a PQ of 1 967 * 968 * Don't set the device offline here; rather let the upper 969 * level drivers eval the PQ to decide whether they should 970 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 971 */ 972 973 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 974 sdev->lockable = sdev->removable; 975 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 976 977 if (sdev->scsi_level >= SCSI_3 || 978 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 979 sdev->ppr = 1; 980 if (inq_result[7] & 0x60) 981 sdev->wdtr = 1; 982 if (inq_result[7] & 0x10) 983 sdev->sdtr = 1; 984 985 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 986 "ANSI: %d%s\n", scsi_device_type(sdev->type), 987 sdev->vendor, sdev->model, sdev->rev, 988 sdev->inq_periph_qual, inq_result[2] & 0x07, 989 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 990 991 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 992 !(*bflags & BLIST_NOTQ)) { 993 sdev->tagged_supported = 1; 994 sdev->simple_tags = 1; 995 } 996 997 /* 998 * Some devices (Texel CD ROM drives) have handshaking problems 999 * when used with the Seagate controllers. borken is initialized 1000 * to 1, and then set it to 0 here. 1001 */ 1002 if ((*bflags & BLIST_BORKEN) == 0) 1003 sdev->borken = 0; 1004 1005 if (*bflags & BLIST_NO_ULD_ATTACH) 1006 sdev->no_uld_attach = 1; 1007 1008 /* 1009 * Apparently some really broken devices (contrary to the SCSI 1010 * standards) need to be selected without asserting ATN 1011 */ 1012 if (*bflags & BLIST_SELECT_NO_ATN) 1013 sdev->select_no_atn = 1; 1014 1015 /* 1016 * Some devices may not want to have a start command automatically 1017 * issued when a device is added. 1018 */ 1019 if (*bflags & BLIST_NOSTARTONADD) 1020 sdev->no_start_on_add = 1; 1021 1022 if (*bflags & BLIST_SINGLELUN) 1023 scsi_target(sdev)->single_lun = 1; 1024 1025 sdev->use_10_for_rw = 1; 1026 1027 /* some devices don't like REPORT SUPPORTED OPERATION CODES 1028 * and will simply timeout causing sd_mod init to take a very 1029 * very long time */ 1030 if (*bflags & BLIST_NO_RSOC) 1031 sdev->no_report_opcodes = 1; 1032 1033 /* set the device running here so that slave configure 1034 * may do I/O */ 1035 mutex_lock(&sdev->state_mutex); 1036 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 1037 if (ret) 1038 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 1039 mutex_unlock(&sdev->state_mutex); 1040 1041 if (ret) { 1042 sdev_printk(KERN_ERR, sdev, 1043 "in wrong state %s to complete scan\n", 1044 scsi_device_state_name(sdev->sdev_state)); 1045 return SCSI_SCAN_NO_RESPONSE; 1046 } 1047 1048 if (*bflags & BLIST_NOT_LOCKABLE) 1049 sdev->lockable = 0; 1050 1051 if (*bflags & BLIST_RETRY_HWERROR) 1052 sdev->retry_hwerror = 1; 1053 1054 if (*bflags & BLIST_NO_DIF) 1055 sdev->no_dif = 1; 1056 1057 if (*bflags & BLIST_UNMAP_LIMIT_WS) 1058 sdev->unmap_limit_for_ws = 1; 1059 1060 if (*bflags & BLIST_IGN_MEDIA_CHANGE) 1061 sdev->ignore_media_change = 1; 1062 1063 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 1064 1065 if (*bflags & BLIST_TRY_VPD_PAGES) 1066 sdev->try_vpd_pages = 1; 1067 else if (*bflags & BLIST_SKIP_VPD_PAGES) 1068 sdev->skip_vpd_pages = 1; 1069 1070 if (*bflags & BLIST_NO_VPD_SIZE) 1071 sdev->no_vpd_size = 1; 1072 1073 transport_configure_device(&sdev->sdev_gendev); 1074 1075 sdev->sdev_bflags = *bflags; 1076 1077 if (scsi_device_is_pseudo_dev(sdev)) 1078 return SCSI_SCAN_LUN_PRESENT; 1079 1080 /* 1081 * No need to freeze the queue as it isn't reachable to anyone else yet. 1082 */ 1083 lim = queue_limits_start_update(sdev->request_queue); 1084 if (*bflags & BLIST_MAX_512) 1085 lim.max_hw_sectors = 512; 1086 else if (*bflags & BLIST_MAX_1024) 1087 lim.max_hw_sectors = 1024; 1088 1089 if (hostt->sdev_configure) 1090 ret = hostt->sdev_configure(sdev, &lim); 1091 if (ret) { 1092 queue_limits_cancel_update(sdev->request_queue); 1093 /* 1094 * If the LLDD reports device not present, don't clutter the 1095 * console with failure messages. 1096 */ 1097 if (ret != -ENXIO) 1098 sdev_printk(KERN_ERR, sdev, 1099 "failed to configure device\n"); 1100 return SCSI_SCAN_NO_RESPONSE; 1101 } 1102 1103 ret = queue_limits_commit_update(sdev->request_queue, &lim); 1104 if (ret) { 1105 sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n"); 1106 return SCSI_SCAN_NO_RESPONSE; 1107 } 1108 1109 /* 1110 * The queue_depth is often changed in ->sdev_configure. 1111 * 1112 * Set up budget map again since memory consumption of the map depends 1113 * on actual queue depth. 1114 */ 1115 if (hostt->sdev_configure) 1116 scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth); 1117 1118 if (sdev->scsi_level >= SCSI_3) 1119 scsi_attach_vpd(sdev); 1120 1121 scsi_cdl_check(sdev); 1122 1123 sdev->max_queue_depth = sdev->queue_depth; 1124 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); 1125 1126 /* 1127 * Ok, the device is now all set up, we can 1128 * register it and tell the rest of the kernel 1129 * about it. 1130 */ 1131 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 1132 return SCSI_SCAN_NO_RESPONSE; 1133 1134 return SCSI_SCAN_LUN_PRESENT; 1135 } 1136 1137 #ifdef CONFIG_SCSI_LOGGING 1138 /** 1139 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1140 * @buf: Output buffer with at least end-first+1 bytes of space 1141 * @inq: Inquiry buffer (input) 1142 * @first: Offset of string into inq 1143 * @end: Index after last character in inq 1144 */ 1145 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1146 unsigned first, unsigned end) 1147 { 1148 unsigned term = 0, idx; 1149 1150 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1151 if (inq[idx+first] > ' ') { 1152 buf[idx] = inq[idx+first]; 1153 term = idx+1; 1154 } else { 1155 buf[idx] = ' '; 1156 } 1157 } 1158 buf[term] = 0; 1159 return buf; 1160 } 1161 #endif 1162 1163 /** 1164 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1165 * @starget: pointer to target device structure 1166 * @lun: LUN of target device 1167 * @bflagsp: store bflags here if not NULL 1168 * @sdevp: probe the LUN corresponding to this scsi_device 1169 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1170 * needed on first scan 1171 * @hostdata: passed to scsi_alloc_sdev() 1172 * 1173 * Description: 1174 * Call scsi_probe_lun, if a LUN with an attached device is found, 1175 * allocate and set it up by calling scsi_add_lun. 1176 * 1177 * Return: 1178 * 1179 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1180 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1181 * attached at the LUN 1182 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1183 **/ 1184 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1185 u64 lun, blist_flags_t *bflagsp, 1186 struct scsi_device **sdevp, 1187 enum scsi_scan_mode rescan, 1188 void *hostdata) 1189 { 1190 struct scsi_device *sdev; 1191 unsigned char *result; 1192 blist_flags_t bflags; 1193 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1194 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1195 1196 /* 1197 * The rescan flag is used as an optimization, the first scan of a 1198 * host adapter calls into here with rescan == 0. 1199 */ 1200 sdev = scsi_device_lookup_by_target(starget, lun); 1201 if (sdev) { 1202 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1203 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1204 "scsi scan: device exists on %s\n", 1205 dev_name(&sdev->sdev_gendev))); 1206 if (sdevp) 1207 *sdevp = sdev; 1208 else 1209 scsi_device_put(sdev); 1210 1211 if (bflagsp) 1212 *bflagsp = scsi_get_device_flags(sdev, 1213 sdev->vendor, 1214 sdev->model); 1215 return SCSI_SCAN_LUN_PRESENT; 1216 } 1217 scsi_device_put(sdev); 1218 } else 1219 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1220 if (!sdev) 1221 goto out; 1222 1223 if (scsi_device_is_pseudo_dev(sdev)) { 1224 if (bflagsp) 1225 *bflagsp = BLIST_NOLUN; 1226 return SCSI_SCAN_LUN_PRESENT; 1227 } 1228 1229 result = kmalloc(result_len, GFP_KERNEL); 1230 if (!result) 1231 goto out_free_sdev; 1232 1233 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1234 goto out_free_result; 1235 1236 if (bflagsp) 1237 *bflagsp = bflags; 1238 /* 1239 * result contains valid SCSI INQUIRY data. 1240 */ 1241 if ((result[0] >> 5) == 3) { 1242 /* 1243 * For a Peripheral qualifier 3 (011b), the SCSI 1244 * spec says: The device server is not capable of 1245 * supporting a physical device on this logical 1246 * unit. 1247 * 1248 * For disks, this implies that there is no 1249 * logical disk configured at sdev->lun, but there 1250 * is a target id responding. 1251 */ 1252 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1253 " peripheral qualifier of 3, device not" 1254 " added\n")) 1255 if (lun == 0) { 1256 SCSI_LOG_SCAN_BUS(1, { 1257 unsigned char vend[9]; 1258 unsigned char mod[17]; 1259 1260 sdev_printk(KERN_INFO, sdev, 1261 "scsi scan: consider passing scsi_mod." 1262 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1263 scsi_inq_str(vend, result, 8, 16), 1264 scsi_inq_str(mod, result, 16, 32)); 1265 }); 1266 1267 } 1268 1269 res = SCSI_SCAN_TARGET_PRESENT; 1270 goto out_free_result; 1271 } 1272 1273 /* 1274 * Some targets may set slight variations of PQ and PDT to signal 1275 * that no LUN is present, so don't add sdev in these cases. 1276 * Two specific examples are: 1277 * 1) NetApp targets: return PQ=1, PDT=0x1f 1278 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1279 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1280 * 1281 * References: 1282 * 1) SCSI SPC-3, pp. 145-146 1283 * PQ=1: "A peripheral device having the specified peripheral 1284 * device type is not connected to this logical unit. However, the 1285 * device server is capable of supporting the specified peripheral 1286 * device type on this logical unit." 1287 * PDT=0x1f: "Unknown or no device type" 1288 * 2) USB UFI 1.0, p. 20 1289 * PDT=00h Direct-access device (floppy) 1290 * PDT=1Fh none (no FDD connected to the requested logical unit) 1291 */ 1292 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1293 (result[0] & 0x1f) == 0x1f && 1294 !scsi_is_wlun(lun)) { 1295 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1296 "scsi scan: peripheral device type" 1297 " of 31, no device added\n")); 1298 res = SCSI_SCAN_TARGET_PRESENT; 1299 goto out_free_result; 1300 } 1301 1302 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1303 if (res == SCSI_SCAN_LUN_PRESENT) { 1304 if (bflags & BLIST_KEY) { 1305 sdev->lockable = 0; 1306 scsi_unlock_floptical(sdev, result); 1307 } 1308 } 1309 1310 out_free_result: 1311 kfree(result); 1312 out_free_sdev: 1313 if (res == SCSI_SCAN_LUN_PRESENT) { 1314 if (sdevp) { 1315 if (scsi_device_get(sdev) == 0) { 1316 *sdevp = sdev; 1317 } else { 1318 __scsi_remove_device(sdev); 1319 res = SCSI_SCAN_NO_RESPONSE; 1320 } 1321 } 1322 } else 1323 __scsi_remove_device(sdev); 1324 out: 1325 return res; 1326 } 1327 1328 /** 1329 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1330 * @starget: pointer to target structure to scan 1331 * @bflags: black/white list flag for LUN 0 1332 * @scsi_level: Which version of the standard does this device adhere to 1333 * @rescan: passed to scsi_probe_add_lun() 1334 * 1335 * Description: 1336 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1337 * scanned) to some maximum lun until a LUN is found with no device 1338 * attached. Use the bflags to figure out any oddities. 1339 * 1340 * Modifies sdevscan->lun. 1341 **/ 1342 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1343 blist_flags_t bflags, int scsi_level, 1344 enum scsi_scan_mode rescan) 1345 { 1346 uint max_dev_lun; 1347 u64 sparse_lun, lun; 1348 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1349 1350 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1351 "scsi scan: Sequential scan\n")); 1352 1353 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1354 /* 1355 * If this device is known to support sparse multiple units, 1356 * override the other settings, and scan all of them. Normally, 1357 * SCSI-3 devices should be scanned via the REPORT LUNS. 1358 */ 1359 if (bflags & BLIST_SPARSELUN) { 1360 max_dev_lun = shost->max_lun; 1361 sparse_lun = 1; 1362 } else 1363 sparse_lun = 0; 1364 1365 /* 1366 * If less than SCSI_1_CCS, and no special lun scanning, stop 1367 * scanning; this matches 2.4 behaviour, but could just be a bug 1368 * (to continue scanning a SCSI_1_CCS device). 1369 * 1370 * This test is broken. We might not have any device on lun0 for 1371 * a sparselun device, and if that's the case then how would we 1372 * know the real scsi_level, eh? It might make sense to just not 1373 * scan any SCSI_1 device for non-0 luns, but that check would best 1374 * go into scsi_alloc_sdev() and just have it return null when asked 1375 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1376 * 1377 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1378 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1379 == 0)) 1380 return; 1381 */ 1382 /* 1383 * If this device is known to support multiple units, override 1384 * the other settings, and scan all of them. 1385 */ 1386 if (bflags & BLIST_FORCELUN) 1387 max_dev_lun = shost->max_lun; 1388 /* 1389 * REGAL CDC-4X: avoid hang after LUN 4 1390 */ 1391 if (bflags & BLIST_MAX5LUN) 1392 max_dev_lun = min(5U, max_dev_lun); 1393 /* 1394 * Do not scan SCSI-2 or lower device past LUN 7, unless 1395 * BLIST_LARGELUN. 1396 */ 1397 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1398 max_dev_lun = min(8U, max_dev_lun); 1399 else 1400 max_dev_lun = min(256U, max_dev_lun); 1401 1402 /* 1403 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1404 * until we reach the max, or no LUN is found and we are not 1405 * sparse_lun. 1406 */ 1407 for (lun = 1; lun < max_dev_lun; ++lun) 1408 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1409 NULL) != SCSI_SCAN_LUN_PRESENT) && 1410 !sparse_lun) 1411 return; 1412 } 1413 1414 /** 1415 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1416 * @starget: which target 1417 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1418 * @rescan: nonzero if we can skip code only needed on first scan 1419 * 1420 * Description: 1421 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1422 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1423 * 1424 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1425 * LUNs even if it's older than SCSI-3. 1426 * If BLIST_NOREPORTLUN is set, return 1 always. 1427 * If BLIST_NOLUN is set, return 0 always. 1428 * If starget->no_report_luns is set, return 1 always. 1429 * 1430 * Return: 1431 * 0: scan completed (or no memory, so further scanning is futile) 1432 * 1: could not scan with REPORT LUN 1433 **/ 1434 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1435 enum scsi_scan_mode rescan) 1436 { 1437 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1438 unsigned int length; 1439 u64 lun; 1440 unsigned int num_luns; 1441 int result; 1442 struct scsi_lun *lunp, *lun_data; 1443 struct scsi_device *sdev; 1444 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1445 struct scsi_failure failure_defs[] = { 1446 { 1447 .sense = UNIT_ATTENTION, 1448 .asc = SCMD_FAILURE_ASC_ANY, 1449 .ascq = SCMD_FAILURE_ASCQ_ANY, 1450 .result = SAM_STAT_CHECK_CONDITION, 1451 }, 1452 /* Fail all CCs except the UA above */ 1453 { 1454 .sense = SCMD_FAILURE_SENSE_ANY, 1455 .result = SAM_STAT_CHECK_CONDITION, 1456 }, 1457 /* Retry any other errors not listed above */ 1458 { 1459 .result = SCMD_FAILURE_RESULT_ANY, 1460 }, 1461 {} 1462 }; 1463 struct scsi_failures failures = { 1464 .total_allowed = 3, 1465 .failure_definitions = failure_defs, 1466 }; 1467 const struct scsi_exec_args exec_args = { 1468 .failures = &failures, 1469 }; 1470 int ret = 0; 1471 1472 /* 1473 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1474 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1475 * support more than 8 LUNs. 1476 * Don't attempt if the target doesn't support REPORT LUNS. 1477 */ 1478 if (bflags & BLIST_NOREPORTLUN) 1479 return 1; 1480 if (starget->scsi_level < SCSI_2 && 1481 starget->scsi_level != SCSI_UNKNOWN) 1482 return 1; 1483 if (starget->scsi_level < SCSI_3 && 1484 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1485 return 1; 1486 if (bflags & BLIST_NOLUN) 1487 return 0; 1488 if (starget->no_report_luns) 1489 return 1; 1490 1491 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1492 sdev = scsi_alloc_sdev(starget, 0, NULL); 1493 if (!sdev) 1494 return 0; 1495 if (scsi_device_get(sdev)) { 1496 __scsi_remove_device(sdev); 1497 return 0; 1498 } 1499 } 1500 1501 /* 1502 * Allocate enough to hold the header (the same size as one scsi_lun) 1503 * plus the number of luns we are requesting. 511 was the default 1504 * value of the now removed max_report_luns parameter. 1505 */ 1506 length = (511 + 1) * sizeof(struct scsi_lun); 1507 retry: 1508 lun_data = kmalloc(length, GFP_KERNEL); 1509 if (!lun_data) { 1510 printk(ALLOC_FAILURE_MSG, __func__); 1511 goto out; 1512 } 1513 1514 scsi_cmd[0] = REPORT_LUNS; 1515 1516 /* 1517 * bytes 1 - 5: reserved, set to zero. 1518 */ 1519 memset(&scsi_cmd[1], 0, 5); 1520 1521 /* 1522 * bytes 6 - 9: length of the command. 1523 */ 1524 put_unaligned_be32(length, &scsi_cmd[6]); 1525 1526 scsi_cmd[10] = 0; /* reserved */ 1527 scsi_cmd[11] = 0; /* control */ 1528 1529 /* 1530 * We can get a UNIT ATTENTION, for example a power on/reset, so 1531 * retry a few times (like sd.c does for TEST UNIT READY). 1532 * Experience shows some combinations of adapter/devices get at 1533 * least two power on/resets. 1534 * 1535 * Illegal requests (for devices that do not support REPORT LUNS) 1536 * should come through as a check condition, and will not generate 1537 * a retry. 1538 */ 1539 scsi_failures_reset_retries(&failures); 1540 1541 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1542 "scsi scan: Sending REPORT LUNS\n")); 1543 1544 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data, 1545 length, SCSI_REPORT_LUNS_TIMEOUT, 3, 1546 &exec_args); 1547 1548 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1549 "scsi scan: REPORT LUNS %s result 0x%x\n", 1550 result ? "failed" : "successful", result)); 1551 if (result) { 1552 /* 1553 * The device probably does not support a REPORT LUN command 1554 */ 1555 ret = 1; 1556 goto out_err; 1557 } 1558 1559 /* 1560 * Get the length from the first four bytes of lun_data. 1561 */ 1562 if (get_unaligned_be32(lun_data->scsi_lun) + 1563 sizeof(struct scsi_lun) > length) { 1564 length = get_unaligned_be32(lun_data->scsi_lun) + 1565 sizeof(struct scsi_lun); 1566 kfree(lun_data); 1567 goto retry; 1568 } 1569 length = get_unaligned_be32(lun_data->scsi_lun); 1570 1571 num_luns = (length / sizeof(struct scsi_lun)); 1572 1573 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1574 "scsi scan: REPORT LUN scan\n")); 1575 1576 /* 1577 * Scan the luns in lun_data. The entry at offset 0 is really 1578 * the header, so start at 1 and go up to and including num_luns. 1579 */ 1580 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1581 lun = scsilun_to_int(lunp); 1582 1583 if (lun > sdev->host->max_lun) { 1584 sdev_printk(KERN_WARNING, sdev, 1585 "lun%llu has a LUN larger than" 1586 " allowed by the host adapter\n", lun); 1587 } else { 1588 int res; 1589 1590 res = scsi_probe_and_add_lun(starget, 1591 lun, NULL, NULL, rescan, NULL); 1592 if (res == SCSI_SCAN_NO_RESPONSE) { 1593 /* 1594 * Got some results, but now none, abort. 1595 */ 1596 sdev_printk(KERN_ERR, sdev, 1597 "Unexpected response" 1598 " from lun %llu while scanning, scan" 1599 " aborted\n", (unsigned long long)lun); 1600 break; 1601 } 1602 } 1603 } 1604 1605 out_err: 1606 kfree(lun_data); 1607 out: 1608 if (scsi_device_created(sdev)) 1609 /* 1610 * the sdev we used didn't appear in the report luns scan 1611 */ 1612 __scsi_remove_device(sdev); 1613 scsi_device_put(sdev); 1614 return ret; 1615 } 1616 1617 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1618 uint id, u64 lun, void *hostdata) 1619 { 1620 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1621 struct device *parent = &shost->shost_gendev; 1622 struct scsi_target *starget; 1623 1624 if (strncmp(scsi_scan_type, "none", 4) == 0) 1625 return ERR_PTR(-ENODEV); 1626 1627 starget = scsi_alloc_target(parent, channel, id); 1628 if (!starget) 1629 return ERR_PTR(-ENOMEM); 1630 scsi_autopm_get_target(starget); 1631 1632 mutex_lock(&shost->scan_mutex); 1633 if (!shost->async_scan) 1634 scsi_complete_async_scans(); 1635 1636 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1637 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1638 SCSI_SCAN_RESCAN, hostdata); 1639 scsi_autopm_put_host(shost); 1640 } 1641 mutex_unlock(&shost->scan_mutex); 1642 scsi_autopm_put_target(starget); 1643 /* 1644 * paired with scsi_alloc_target(). Target will be destroyed unless 1645 * scsi_probe_and_add_lun made an underlying device visible 1646 */ 1647 scsi_target_reap(starget); 1648 put_device(&starget->dev); 1649 1650 return sdev; 1651 } 1652 EXPORT_SYMBOL(__scsi_add_device); 1653 1654 /** 1655 * scsi_add_device - creates a new SCSI (LU) instance 1656 * @host: the &Scsi_Host instance where the device is located 1657 * @channel: target channel number (rarely other than %0) 1658 * @target: target id number 1659 * @lun: LUN of target device 1660 * 1661 * Probe for a specific LUN and add it if found. 1662 * 1663 * Notes: This call is usually performed internally during a SCSI 1664 * bus scan when an HBA is added (i.e. scsi_scan_host()). So it 1665 * should only be called if the HBA becomes aware of a new SCSI 1666 * device (LU) after scsi_scan_host() has completed. If successful 1667 * this call can lead to sdev_init() and sdev_configure() callbacks 1668 * into the LLD. 1669 * 1670 * Return: %0 on success or negative error code on failure 1671 */ 1672 int scsi_add_device(struct Scsi_Host *host, uint channel, 1673 uint target, u64 lun) 1674 { 1675 struct scsi_device *sdev = 1676 __scsi_add_device(host, channel, target, lun, NULL); 1677 if (IS_ERR(sdev)) 1678 return PTR_ERR(sdev); 1679 1680 scsi_device_put(sdev); 1681 return 0; 1682 } 1683 EXPORT_SYMBOL(scsi_add_device); 1684 1685 int scsi_resume_device(struct scsi_device *sdev) 1686 { 1687 struct device *dev = &sdev->sdev_gendev; 1688 int ret = 0; 1689 1690 device_lock(dev); 1691 1692 /* 1693 * Bail out if the device or its queue are not running. Otherwise, 1694 * the rescan may block waiting for commands to be executed, with us 1695 * holding the device lock. This can result in a potential deadlock 1696 * in the power management core code when system resume is on-going. 1697 */ 1698 if (sdev->sdev_state != SDEV_RUNNING || 1699 blk_queue_pm_only(sdev->request_queue)) { 1700 ret = -EWOULDBLOCK; 1701 goto unlock; 1702 } 1703 1704 if (dev->driver && try_module_get(dev->driver->owner)) { 1705 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1706 1707 if (drv->resume) 1708 ret = drv->resume(dev); 1709 module_put(dev->driver->owner); 1710 } 1711 1712 unlock: 1713 device_unlock(dev); 1714 1715 return ret; 1716 } 1717 EXPORT_SYMBOL(scsi_resume_device); 1718 1719 int scsi_rescan_device(struct scsi_device *sdev) 1720 { 1721 struct device *dev = &sdev->sdev_gendev; 1722 int ret = 0; 1723 1724 device_lock(dev); 1725 1726 /* 1727 * Bail out if the device or its queue are not running. Otherwise, 1728 * the rescan may block waiting for commands to be executed, with us 1729 * holding the device lock. This can result in a potential deadlock 1730 * in the power management core code when system resume is on-going. 1731 */ 1732 if (sdev->sdev_state != SDEV_RUNNING || 1733 blk_queue_pm_only(sdev->request_queue)) { 1734 ret = -EWOULDBLOCK; 1735 goto unlock; 1736 } 1737 1738 scsi_attach_vpd(sdev); 1739 scsi_cdl_check(sdev); 1740 1741 if (sdev->handler && sdev->handler->rescan) 1742 sdev->handler->rescan(sdev); 1743 1744 if (dev->driver && try_module_get(dev->driver->owner)) { 1745 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1746 1747 if (drv->rescan) 1748 drv->rescan(dev); 1749 module_put(dev->driver->owner); 1750 } 1751 1752 unlock: 1753 device_unlock(dev); 1754 1755 return ret; 1756 } 1757 EXPORT_SYMBOL(scsi_rescan_device); 1758 1759 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1760 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1761 { 1762 struct Scsi_Host *shost = dev_to_shost(parent); 1763 blist_flags_t bflags = 0; 1764 int res; 1765 struct scsi_target *starget; 1766 1767 if (shost->this_id == id) 1768 /* 1769 * Don't scan the host adapter 1770 */ 1771 return; 1772 1773 starget = scsi_alloc_target(parent, channel, id); 1774 if (!starget) 1775 return; 1776 scsi_autopm_get_target(starget); 1777 1778 if (lun != SCAN_WILD_CARD) { 1779 /* 1780 * Scan for a specific host/chan/id/lun. 1781 */ 1782 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1783 goto out_reap; 1784 } 1785 1786 /* 1787 * Scan LUN 0, if there is some response, scan further. Ideally, we 1788 * would not configure LUN 0 until all LUNs are scanned. 1789 */ 1790 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1791 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1792 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1793 /* 1794 * The REPORT LUN did not scan the target, 1795 * do a sequential scan. 1796 */ 1797 scsi_sequential_lun_scan(starget, bflags, 1798 starget->scsi_level, rescan); 1799 } 1800 1801 out_reap: 1802 scsi_autopm_put_target(starget); 1803 /* 1804 * paired with scsi_alloc_target(): determine if the target has 1805 * any children at all and if not, nuke it 1806 */ 1807 scsi_target_reap(starget); 1808 1809 put_device(&starget->dev); 1810 } 1811 1812 /** 1813 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1814 * @parent: host to scan 1815 * @channel: channel to scan 1816 * @id: target id to scan 1817 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1818 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1819 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1820 * and SCSI_SCAN_MANUAL to force scanning even if 1821 * 'scan=manual' is set. 1822 * 1823 * Description: 1824 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1825 * and possibly all LUNs on the target id. 1826 * 1827 * First try a REPORT LUN scan, if that does not scan the target, do a 1828 * sequential scan of LUNs on the target id. 1829 **/ 1830 void scsi_scan_target(struct device *parent, unsigned int channel, 1831 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1832 { 1833 struct Scsi_Host *shost = dev_to_shost(parent); 1834 1835 if (strncmp(scsi_scan_type, "none", 4) == 0) 1836 return; 1837 1838 if (rescan != SCSI_SCAN_MANUAL && 1839 strncmp(scsi_scan_type, "manual", 6) == 0) 1840 return; 1841 1842 mutex_lock(&shost->scan_mutex); 1843 if (!shost->async_scan) 1844 scsi_complete_async_scans(); 1845 1846 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1847 __scsi_scan_target(parent, channel, id, lun, rescan); 1848 scsi_autopm_put_host(shost); 1849 } 1850 mutex_unlock(&shost->scan_mutex); 1851 } 1852 EXPORT_SYMBOL(scsi_scan_target); 1853 1854 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1855 unsigned int id, u64 lun, 1856 enum scsi_scan_mode rescan) 1857 { 1858 uint order_id; 1859 1860 if (id == SCAN_WILD_CARD) 1861 for (id = 0; id < shost->max_id; ++id) { 1862 /* 1863 * XXX adapter drivers when possible (FCP, iSCSI) 1864 * could modify max_id to match the current max, 1865 * not the absolute max. 1866 * 1867 * XXX add a shost id iterator, so for example, 1868 * the FC ID can be the same as a target id 1869 * without a huge overhead of sparse id's. 1870 */ 1871 if (shost->reverse_ordering) 1872 /* 1873 * Scan from high to low id. 1874 */ 1875 order_id = shost->max_id - id - 1; 1876 else 1877 order_id = id; 1878 __scsi_scan_target(&shost->shost_gendev, channel, 1879 order_id, lun, rescan); 1880 } 1881 else 1882 __scsi_scan_target(&shost->shost_gendev, channel, 1883 id, lun, rescan); 1884 } 1885 1886 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1887 unsigned int id, u64 lun, 1888 enum scsi_scan_mode rescan) 1889 { 1890 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1891 "%s: <%u:%u:%llu>\n", 1892 __func__, channel, id, lun)); 1893 1894 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1895 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1896 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1897 return -EINVAL; 1898 1899 mutex_lock(&shost->scan_mutex); 1900 if (!shost->async_scan) 1901 scsi_complete_async_scans(); 1902 1903 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1904 if (channel == SCAN_WILD_CARD) 1905 for (channel = 0; channel <= shost->max_channel; 1906 channel++) 1907 scsi_scan_channel(shost, channel, id, lun, 1908 rescan); 1909 else 1910 scsi_scan_channel(shost, channel, id, lun, rescan); 1911 scsi_autopm_put_host(shost); 1912 } 1913 mutex_unlock(&shost->scan_mutex); 1914 1915 return 0; 1916 } 1917 EXPORT_SYMBOL(scsi_scan_host_selected); 1918 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1919 { 1920 struct scsi_device *sdev; 1921 shost_for_each_device(sdev, shost) { 1922 /* target removed before the device could be added */ 1923 if (sdev->sdev_state == SDEV_DEL) 1924 continue; 1925 /* If device is already visible, skip adding it to sysfs */ 1926 if (sdev->is_visible) 1927 continue; 1928 if (!scsi_host_scan_allowed(shost) || 1929 scsi_sysfs_add_sdev(sdev) != 0) 1930 __scsi_remove_device(sdev); 1931 } 1932 } 1933 1934 /** 1935 * scsi_prep_async_scan - prepare for an async scan 1936 * @shost: the host which will be scanned 1937 * Returns: a cookie to be passed to scsi_finish_async_scan() 1938 * 1939 * Tells the midlayer this host is going to do an asynchronous scan. 1940 * It reserves the host's position in the scanning list and ensures 1941 * that other asynchronous scans started after this one won't affect the 1942 * ordering of the discovered devices. 1943 */ 1944 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1945 { 1946 struct async_scan_data *data = NULL; 1947 unsigned long flags; 1948 1949 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1950 return NULL; 1951 1952 mutex_lock(&shost->scan_mutex); 1953 if (shost->async_scan) { 1954 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1955 goto err; 1956 } 1957 1958 data = kmalloc_obj(*data); 1959 if (!data) 1960 goto err; 1961 data->shost = scsi_host_get(shost); 1962 if (!data->shost) 1963 goto err; 1964 init_completion(&data->prev_finished); 1965 1966 spin_lock_irqsave(shost->host_lock, flags); 1967 shost->async_scan = 1; 1968 spin_unlock_irqrestore(shost->host_lock, flags); 1969 mutex_unlock(&shost->scan_mutex); 1970 1971 spin_lock(&async_scan_lock); 1972 if (list_empty(&scanning_hosts)) 1973 complete(&data->prev_finished); 1974 list_add_tail(&data->list, &scanning_hosts); 1975 spin_unlock(&async_scan_lock); 1976 1977 return data; 1978 1979 err: 1980 mutex_unlock(&shost->scan_mutex); 1981 kfree(data); 1982 return NULL; 1983 } 1984 1985 /** 1986 * scsi_finish_async_scan - asynchronous scan has finished 1987 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1988 * 1989 * All the devices currently attached to this host have been found. 1990 * This function announces all the devices it has found to the rest 1991 * of the system. 1992 */ 1993 static void scsi_finish_async_scan(struct async_scan_data *data) 1994 { 1995 struct Scsi_Host *shost; 1996 unsigned long flags; 1997 1998 if (!data) 1999 return; 2000 2001 shost = data->shost; 2002 2003 mutex_lock(&shost->scan_mutex); 2004 2005 if (!shost->async_scan) { 2006 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 2007 dump_stack(); 2008 mutex_unlock(&shost->scan_mutex); 2009 return; 2010 } 2011 2012 wait_for_completion(&data->prev_finished); 2013 2014 scsi_sysfs_add_devices(shost); 2015 2016 spin_lock_irqsave(shost->host_lock, flags); 2017 shost->async_scan = 0; 2018 spin_unlock_irqrestore(shost->host_lock, flags); 2019 2020 mutex_unlock(&shost->scan_mutex); 2021 2022 spin_lock(&async_scan_lock); 2023 list_del(&data->list); 2024 if (!list_empty(&scanning_hosts)) { 2025 struct async_scan_data *next = list_entry(scanning_hosts.next, 2026 struct async_scan_data, list); 2027 complete(&next->prev_finished); 2028 } 2029 spin_unlock(&async_scan_lock); 2030 2031 scsi_autopm_put_host(shost); 2032 scsi_host_put(shost); 2033 kfree(data); 2034 } 2035 2036 static void do_scsi_scan_host(struct Scsi_Host *shost) 2037 { 2038 if (shost->hostt->scan_finished) { 2039 unsigned long start = jiffies; 2040 if (shost->hostt->scan_start) 2041 shost->hostt->scan_start(shost); 2042 2043 while (!shost->hostt->scan_finished(shost, jiffies - start)) 2044 msleep(10); 2045 } else { 2046 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 2047 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 2048 } 2049 } 2050 2051 static void do_scan_async(void *_data, async_cookie_t c) 2052 { 2053 struct async_scan_data *data = _data; 2054 struct Scsi_Host *shost = data->shost; 2055 2056 do_scsi_scan_host(shost); 2057 scsi_finish_async_scan(data); 2058 } 2059 2060 /** 2061 * scsi_scan_host - scan the given adapter 2062 * @shost: adapter to scan 2063 * 2064 * Notes: Should be called after scsi_add_host() 2065 **/ 2066 void scsi_scan_host(struct Scsi_Host *shost) 2067 { 2068 struct async_scan_data *data; 2069 2070 if (strncmp(scsi_scan_type, "none", 4) == 0 || 2071 strncmp(scsi_scan_type, "manual", 6) == 0) 2072 return; 2073 if (scsi_autopm_get_host(shost) < 0) 2074 return; 2075 2076 data = scsi_prep_async_scan(shost); 2077 if (!data) { 2078 do_scsi_scan_host(shost); 2079 scsi_autopm_put_host(shost); 2080 return; 2081 } 2082 2083 /* register with the async subsystem so wait_for_device_probe() 2084 * will flush this work 2085 */ 2086 async_schedule(do_scan_async, data); 2087 2088 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 2089 } 2090 EXPORT_SYMBOL(scsi_scan_host); 2091 2092 void scsi_forget_host(struct Scsi_Host *shost) 2093 { 2094 struct scsi_device *sdev; 2095 unsigned long flags; 2096 2097 restart: 2098 spin_lock_irqsave(shost->host_lock, flags); 2099 list_for_each_entry(sdev, &shost->__devices, siblings) { 2100 if (scsi_device_is_pseudo_dev(sdev) || 2101 sdev->sdev_state == SDEV_DEL) 2102 continue; 2103 spin_unlock_irqrestore(shost->host_lock, flags); 2104 __scsi_remove_device(sdev); 2105 goto restart; 2106 } 2107 spin_unlock_irqrestore(shost->host_lock, flags); 2108 2109 /* 2110 * Remove the pseudo device last since it may be needed during removal 2111 * of other SCSI devices. 2112 */ 2113 if (shost->pseudo_sdev) 2114 __scsi_remove_device(shost->pseudo_sdev); 2115 } 2116 2117 /** 2118 * scsi_get_pseudo_sdev() - Attach a pseudo SCSI device to a SCSI host 2119 * @shost: Host that needs a pseudo SCSI device 2120 * 2121 * Lock status: None assumed. 2122 * 2123 * Returns: The scsi_device or NULL 2124 * 2125 * Notes: 2126 * Attach a single scsi_device to the Scsi_Host. The primary aim for this 2127 * device is to serve as a container from which SCSI commands can be 2128 * allocated. Each SCSI command will carry a command tag allocated by the 2129 * block layer. These SCSI commands can be used by the LLDD to send 2130 * internal or passthrough commands without having to manage tag allocation 2131 * inside the LLDD. 2132 */ 2133 struct scsi_device *scsi_get_pseudo_sdev(struct Scsi_Host *shost) 2134 { 2135 struct scsi_device *sdev = NULL; 2136 struct scsi_target *starget; 2137 2138 guard(mutex)(&shost->scan_mutex); 2139 2140 if (!scsi_host_scan_allowed(shost)) 2141 goto out; 2142 2143 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->max_id); 2144 if (!starget) 2145 goto out; 2146 2147 sdev = scsi_alloc_sdev(starget, U64_MAX, NULL); 2148 if (!sdev) { 2149 scsi_target_reap(starget); 2150 goto put_target; 2151 } 2152 2153 sdev->borken = 0; 2154 2155 put_target: 2156 /* See also the get_device(dev) call in scsi_alloc_target(). */ 2157 put_device(&starget->dev); 2158 2159 out: 2160 return sdev; 2161 } 2162