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