1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * scsi_scan.c 4 * 5 * Copyright (C) 2000 Eric Youngdale, 6 * Copyright (C) 2002 Patrick Mansfield 7 * 8 * The general scanning/probing algorithm is as follows, exceptions are 9 * made to it depending on device specific flags, compilation options, and 10 * global variable (boot or module load time) settings. 11 * 12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a 13 * device attached, a scsi_device is allocated and setup for it. 14 * 15 * For every id of every channel on the given host: 16 * 17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no 18 * device or storage attached to LUN 0): 19 * 20 * If LUN 0 has a device attached, allocate and setup a 21 * scsi_device for it. 22 * 23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan 24 * all of the LUNs returned by the REPORT LUN; else, 25 * sequentially scan LUNs up until some maximum is reached, 26 * or a LUN is seen that cannot have a device attached to it. 27 */ 28 29 #include <linux/module.h> 30 #include <linux/moduleparam.h> 31 #include <linux/init.h> 32 #include <linux/blkdev.h> 33 #include <linux/delay.h> 34 #include <linux/kthread.h> 35 #include <linux/spinlock.h> 36 #include <linux/async.h> 37 #include <linux/slab.h> 38 #include <asm/unaligned.h> 39 40 #include <scsi/scsi.h> 41 #include <scsi/scsi_cmnd.h> 42 #include <scsi/scsi_device.h> 43 #include <scsi/scsi_driver.h> 44 #include <scsi/scsi_devinfo.h> 45 #include <scsi/scsi_host.h> 46 #include <scsi/scsi_transport.h> 47 #include <scsi/scsi_dh.h> 48 #include <scsi/scsi_eh.h> 49 50 #include "scsi_priv.h" 51 #include "scsi_logging.h" 52 53 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 54 " SCSI scanning, some SCSI devices might not be configured\n" 55 56 /* 57 * Default timeout 58 */ 59 #define SCSI_TIMEOUT (2*HZ) 60 #define SCSI_REPORT_LUNS_TIMEOUT (30*HZ) 61 62 /* 63 * Prefix values for the SCSI id's (stored in sysfs name field) 64 */ 65 #define SCSI_UID_SER_NUM 'S' 66 #define SCSI_UID_UNKNOWN 'Z' 67 68 /* 69 * Return values of some of the scanning functions. 70 * 71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 72 * includes allocation or general failures preventing IO from being sent. 73 * 74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 75 * on the given LUN. 76 * 77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 78 * given LUN. 79 */ 80 #define SCSI_SCAN_NO_RESPONSE 0 81 #define SCSI_SCAN_TARGET_PRESENT 1 82 #define SCSI_SCAN_LUN_PRESENT 2 83 84 static const char *scsi_null_device_strs = "nullnullnullnull"; 85 86 #define MAX_SCSI_LUNS 512 87 88 static u64 max_scsi_luns = MAX_SCSI_LUNS; 89 90 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR); 91 MODULE_PARM_DESC(max_luns, 92 "last scsi LUN (should be between 1 and 2^64-1)"); 93 94 #ifdef CONFIG_SCSI_SCAN_ASYNC 95 #define SCSI_SCAN_TYPE_DEFAULT "async" 96 #else 97 #define SCSI_SCAN_TYPE_DEFAULT "sync" 98 #endif 99 100 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 if (list_empty(&scanning_hosts)) 155 return 0; 156 /* If we can't get memory immediately, that's OK. Just 157 * sleep a little. Even if we never get memory, the async 158 * scans will finish eventually. 159 */ 160 data = kmalloc(sizeof(*data), GFP_KERNEL); 161 if (!data) 162 msleep(1); 163 } while (!data); 164 165 data->shost = NULL; 166 init_completion(&data->prev_finished); 167 168 spin_lock(&async_scan_lock); 169 /* Check that there's still somebody else on the list */ 170 if (list_empty(&scanning_hosts)) 171 goto done; 172 list_add_tail(&data->list, &scanning_hosts); 173 spin_unlock(&async_scan_lock); 174 175 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 176 wait_for_completion(&data->prev_finished); 177 178 spin_lock(&async_scan_lock); 179 list_del(&data->list); 180 if (!list_empty(&scanning_hosts)) { 181 struct async_scan_data *next = list_entry(scanning_hosts.next, 182 struct async_scan_data, list); 183 complete(&next->prev_finished); 184 } 185 done: 186 spin_unlock(&async_scan_lock); 187 188 kfree(data); 189 return 0; 190 } 191 192 /** 193 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 194 * @sdev: scsi device to send command to 195 * @result: area to store the result of the MODE SENSE 196 * 197 * Description: 198 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 199 * Called for BLIST_KEY devices. 200 **/ 201 static void scsi_unlock_floptical(struct scsi_device *sdev, 202 unsigned char *result) 203 { 204 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 205 206 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n"); 207 scsi_cmd[0] = MODE_SENSE; 208 scsi_cmd[1] = 0; 209 scsi_cmd[2] = 0x2e; 210 scsi_cmd[3] = 0; 211 scsi_cmd[4] = 0x2a; /* size */ 212 scsi_cmd[5] = 0; 213 scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, result, 0x2a, 214 SCSI_TIMEOUT, 3, NULL); 215 } 216 217 static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, 218 unsigned int depth) 219 { 220 int new_shift = sbitmap_calculate_shift(depth); 221 bool need_alloc = !sdev->budget_map.map; 222 bool need_free = false; 223 int ret; 224 struct sbitmap sb_backup; 225 226 depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev)); 227 228 /* 229 * realloc if new shift is calculated, which is caused by setting 230 * up one new default queue depth after calling ->device_configure 231 */ 232 if (!need_alloc && new_shift != sdev->budget_map.shift) 233 need_alloc = need_free = true; 234 235 if (!need_alloc) 236 return 0; 237 238 /* 239 * Request queue has to be frozen for reallocating budget map, 240 * and here disk isn't added yet, so freezing is pretty fast 241 */ 242 if (need_free) { 243 blk_mq_freeze_queue(sdev->request_queue); 244 sb_backup = sdev->budget_map; 245 } 246 ret = sbitmap_init_node(&sdev->budget_map, 247 scsi_device_max_queue_depth(sdev), 248 new_shift, GFP_KERNEL, 249 sdev->request_queue->node, false, true); 250 if (!ret) 251 sbitmap_resize(&sdev->budget_map, depth); 252 253 if (need_free) { 254 if (ret) 255 sdev->budget_map = sb_backup; 256 else 257 sbitmap_free(&sb_backup); 258 ret = 0; 259 blk_mq_unfreeze_queue(sdev->request_queue); 260 } 261 return ret; 262 } 263 264 /** 265 * scsi_alloc_sdev - allocate and setup a scsi_Device 266 * @starget: which target to allocate a &scsi_device for 267 * @lun: which lun 268 * @hostdata: usually NULL and set by ->slave_alloc instead 269 * 270 * Description: 271 * Allocate, initialize for io, and return a pointer to a scsi_Device. 272 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 273 * adds scsi_Device to the appropriate list. 274 * 275 * Return value: 276 * scsi_Device pointer, or NULL on failure. 277 **/ 278 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 279 u64 lun, void *hostdata) 280 { 281 unsigned int depth; 282 struct scsi_device *sdev; 283 struct request_queue *q; 284 int display_failure_msg = 1, ret; 285 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 286 struct queue_limits lim; 287 288 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 289 GFP_KERNEL); 290 if (!sdev) 291 goto out; 292 293 sdev->vendor = scsi_null_device_strs; 294 sdev->model = scsi_null_device_strs; 295 sdev->rev = scsi_null_device_strs; 296 sdev->host = shost; 297 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 298 sdev->id = starget->id; 299 sdev->lun = lun; 300 sdev->channel = starget->channel; 301 mutex_init(&sdev->state_mutex); 302 sdev->sdev_state = SDEV_CREATED; 303 INIT_LIST_HEAD(&sdev->siblings); 304 INIT_LIST_HEAD(&sdev->same_target_siblings); 305 INIT_LIST_HEAD(&sdev->starved_entry); 306 INIT_LIST_HEAD(&sdev->event_list); 307 spin_lock_init(&sdev->list_lock); 308 mutex_init(&sdev->inquiry_mutex); 309 INIT_WORK(&sdev->event_work, scsi_evt_thread); 310 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 311 312 sdev->sdev_gendev.parent = get_device(&starget->dev); 313 sdev->sdev_target = starget; 314 315 /* usually NULL and set by ->slave_alloc instead */ 316 sdev->hostdata = hostdata; 317 318 /* if the device needs this changing, it may do so in the 319 * slave_configure function */ 320 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 321 322 /* 323 * Some low level driver could use device->type 324 */ 325 sdev->type = -1; 326 327 /* 328 * Assume that the device will have handshaking problems, 329 * and then fix this field later if it turns out it 330 * doesn't 331 */ 332 sdev->borken = 1; 333 334 sdev->sg_reserved_size = INT_MAX; 335 336 scsi_init_limits(shost, &lim); 337 q = blk_mq_alloc_queue(&sdev->host->tag_set, &lim, NULL); 338 if (IS_ERR(q)) { 339 /* release fn is set up in scsi_sysfs_device_initialise, so 340 * have to free and put manually here */ 341 put_device(&starget->dev); 342 kfree(sdev); 343 goto out; 344 } 345 kref_get(&sdev->host->tagset_refcnt); 346 sdev->request_queue = q; 347 q->queuedata = sdev; 348 349 depth = sdev->host->cmd_per_lun ?: 1; 350 351 /* 352 * Use .can_queue as budget map's depth because we have to 353 * support adjusting queue depth from sysfs. Meantime use 354 * default device queue depth to figure out sbitmap shift 355 * since we use this queue depth most of times. 356 */ 357 if (scsi_realloc_sdev_budget_map(sdev, depth)) { 358 put_device(&starget->dev); 359 kfree(sdev); 360 goto out; 361 } 362 363 scsi_change_queue_depth(sdev, depth); 364 365 scsi_sysfs_device_initialize(sdev); 366 367 if (shost->hostt->slave_alloc) { 368 ret = shost->hostt->slave_alloc(sdev); 369 if (ret) { 370 /* 371 * if LLDD reports slave not present, don't clutter 372 * console with alloc failure messages 373 */ 374 if (ret == -ENXIO) 375 display_failure_msg = 0; 376 goto out_device_destroy; 377 } 378 } 379 380 return sdev; 381 382 out_device_destroy: 383 __scsi_remove_device(sdev); 384 out: 385 if (display_failure_msg) 386 printk(ALLOC_FAILURE_MSG, __func__); 387 return NULL; 388 } 389 390 static void scsi_target_destroy(struct scsi_target *starget) 391 { 392 struct device *dev = &starget->dev; 393 struct Scsi_Host *shost = dev_to_shost(dev->parent); 394 unsigned long flags; 395 396 BUG_ON(starget->state == STARGET_DEL); 397 starget->state = STARGET_DEL; 398 transport_destroy_device(dev); 399 spin_lock_irqsave(shost->host_lock, flags); 400 if (shost->hostt->target_destroy) 401 shost->hostt->target_destroy(starget); 402 list_del_init(&starget->siblings); 403 spin_unlock_irqrestore(shost->host_lock, flags); 404 put_device(dev); 405 } 406 407 static void scsi_target_dev_release(struct device *dev) 408 { 409 struct device *parent = dev->parent; 410 struct scsi_target *starget = to_scsi_target(dev); 411 412 kfree(starget); 413 put_device(parent); 414 } 415 416 static const struct device_type scsi_target_type = { 417 .name = "scsi_target", 418 .release = scsi_target_dev_release, 419 }; 420 421 int scsi_is_target_device(const struct device *dev) 422 { 423 return dev->type == &scsi_target_type; 424 } 425 EXPORT_SYMBOL(scsi_is_target_device); 426 427 static struct scsi_target *__scsi_find_target(struct device *parent, 428 int channel, uint id) 429 { 430 struct scsi_target *starget, *found_starget = NULL; 431 struct Scsi_Host *shost = dev_to_shost(parent); 432 /* 433 * Search for an existing target for this sdev. 434 */ 435 list_for_each_entry(starget, &shost->__targets, siblings) { 436 if (starget->id == id && 437 starget->channel == channel) { 438 found_starget = starget; 439 break; 440 } 441 } 442 if (found_starget) 443 get_device(&found_starget->dev); 444 445 return found_starget; 446 } 447 448 /** 449 * scsi_target_reap_ref_release - remove target from visibility 450 * @kref: the reap_ref in the target being released 451 * 452 * Called on last put of reap_ref, which is the indication that no device 453 * under this target is visible anymore, so render the target invisible in 454 * sysfs. Note: we have to be in user context here because the target reaps 455 * should be done in places where the scsi device visibility is being removed. 456 */ 457 static void scsi_target_reap_ref_release(struct kref *kref) 458 { 459 struct scsi_target *starget 460 = container_of(kref, struct scsi_target, reap_ref); 461 462 /* 463 * if we get here and the target is still in a CREATED state that 464 * means it was allocated but never made visible (because a scan 465 * turned up no LUNs), so don't call device_del() on it. 466 */ 467 if ((starget->state != STARGET_CREATED) && 468 (starget->state != STARGET_CREATED_REMOVE)) { 469 transport_remove_device(&starget->dev); 470 device_del(&starget->dev); 471 } 472 scsi_target_destroy(starget); 473 } 474 475 static void scsi_target_reap_ref_put(struct scsi_target *starget) 476 { 477 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 478 } 479 480 /** 481 * scsi_alloc_target - allocate a new or find an existing target 482 * @parent: parent of the target (need not be a scsi host) 483 * @channel: target channel number (zero if no channels) 484 * @id: target id number 485 * 486 * Return an existing target if one exists, provided it hasn't already 487 * gone into STARGET_DEL state, otherwise allocate a new target. 488 * 489 * The target is returned with an incremented reference, so the caller 490 * is responsible for both reaping and doing a last put 491 */ 492 static struct scsi_target *scsi_alloc_target(struct device *parent, 493 int channel, uint id) 494 { 495 struct Scsi_Host *shost = dev_to_shost(parent); 496 struct device *dev = NULL; 497 unsigned long flags; 498 const int size = sizeof(struct scsi_target) 499 + shost->transportt->target_size; 500 struct scsi_target *starget; 501 struct scsi_target *found_target; 502 int error, ref_got; 503 504 starget = kzalloc(size, GFP_KERNEL); 505 if (!starget) { 506 printk(KERN_ERR "%s: allocation failure\n", __func__); 507 return NULL; 508 } 509 dev = &starget->dev; 510 device_initialize(dev); 511 kref_init(&starget->reap_ref); 512 dev->parent = get_device(parent); 513 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 514 dev->bus = &scsi_bus_type; 515 dev->type = &scsi_target_type; 516 scsi_enable_async_suspend(dev); 517 starget->id = id; 518 starget->channel = channel; 519 starget->can_queue = 0; 520 INIT_LIST_HEAD(&starget->siblings); 521 INIT_LIST_HEAD(&starget->devices); 522 starget->state = STARGET_CREATED; 523 starget->scsi_level = SCSI_2; 524 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 525 retry: 526 spin_lock_irqsave(shost->host_lock, flags); 527 528 found_target = __scsi_find_target(parent, channel, id); 529 if (found_target) 530 goto found; 531 532 list_add_tail(&starget->siblings, &shost->__targets); 533 spin_unlock_irqrestore(shost->host_lock, flags); 534 /* allocate and add */ 535 transport_setup_device(dev); 536 if (shost->hostt->target_alloc) { 537 error = shost->hostt->target_alloc(starget); 538 539 if(error) { 540 if (error != -ENXIO) 541 dev_err(dev, "target allocation failed, error %d\n", error); 542 /* don't want scsi_target_reap to do the final 543 * put because it will be under the host lock */ 544 scsi_target_destroy(starget); 545 return NULL; 546 } 547 } 548 get_device(dev); 549 550 return starget; 551 552 found: 553 /* 554 * release routine already fired if kref is zero, so if we can still 555 * take the reference, the target must be alive. If we can't, it must 556 * be dying and we need to wait for a new target 557 */ 558 ref_got = kref_get_unless_zero(&found_target->reap_ref); 559 560 spin_unlock_irqrestore(shost->host_lock, flags); 561 if (ref_got) { 562 put_device(dev); 563 return found_target; 564 } 565 /* 566 * Unfortunately, we found a dying target; need to wait until it's 567 * dead before we can get a new one. There is an anomaly here. We 568 * *should* call scsi_target_reap() to balance the kref_get() of the 569 * reap_ref above. However, since the target being released, it's 570 * already invisible and the reap_ref is irrelevant. If we call 571 * scsi_target_reap() we might spuriously do another device_del() on 572 * an already invisible target. 573 */ 574 put_device(&found_target->dev); 575 /* 576 * length of time is irrelevant here, we just want to yield the CPU 577 * for a tick to avoid busy waiting for the target to die. 578 */ 579 msleep(1); 580 goto retry; 581 } 582 583 /** 584 * scsi_target_reap - check to see if target is in use and destroy if not 585 * @starget: target to be checked 586 * 587 * This is used after removing a LUN or doing a last put of the target 588 * it checks atomically that nothing is using the target and removes 589 * it if so. 590 */ 591 void scsi_target_reap(struct scsi_target *starget) 592 { 593 /* 594 * serious problem if this triggers: STARGET_DEL is only set in the if 595 * the reap_ref drops to zero, so we're trying to do another final put 596 * on an already released kref 597 */ 598 BUG_ON(starget->state == STARGET_DEL); 599 scsi_target_reap_ref_put(starget); 600 } 601 602 /** 603 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 604 * INQUIRY result string 605 * @s: INQUIRY result string to sanitize 606 * @len: length of the string 607 * 608 * Description: 609 * The SCSI spec says that INQUIRY vendor, product, and revision 610 * strings must consist entirely of graphic ASCII characters, 611 * padded on the right with spaces. Since not all devices obey 612 * this rule, we will replace non-graphic or non-ASCII characters 613 * with spaces. Exception: a NUL character is interpreted as a 614 * string terminator, so all the following characters are set to 615 * spaces. 616 **/ 617 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 618 { 619 int terminated = 0; 620 621 for (; len > 0; (--len, ++s)) { 622 if (*s == 0) 623 terminated = 1; 624 if (terminated || *s < 0x20 || *s > 0x7e) 625 *s = ' '; 626 } 627 } 628 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 629 630 631 /** 632 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 633 * @sdev: scsi_device to probe 634 * @inq_result: area to store the INQUIRY result 635 * @result_len: len of inq_result 636 * @bflags: store any bflags found here 637 * 638 * Description: 639 * Probe the lun associated with @req using a standard SCSI INQUIRY; 640 * 641 * If the INQUIRY is successful, zero is returned and the 642 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 643 * are copied to the scsi_device any flags value is stored in *@bflags. 644 **/ 645 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 646 int result_len, blist_flags_t *bflags) 647 { 648 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 649 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 650 int response_len = 0; 651 int pass, count, result, resid; 652 struct scsi_failure failure_defs[] = { 653 /* 654 * not-ready to ready transition [asc/ascq=0x28/0x0] or 655 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY 656 * should not yield UNIT_ATTENTION but many buggy devices do 657 * so anyway. 658 */ 659 { 660 .sense = UNIT_ATTENTION, 661 .asc = 0x28, 662 .result = SAM_STAT_CHECK_CONDITION, 663 }, 664 { 665 .sense = UNIT_ATTENTION, 666 .asc = 0x29, 667 .result = SAM_STAT_CHECK_CONDITION, 668 }, 669 { 670 .allowed = 1, 671 .result = DID_TIME_OUT << 16, 672 }, 673 {} 674 }; 675 struct scsi_failures failures = { 676 .total_allowed = 3, 677 .failure_definitions = failure_defs, 678 }; 679 const struct scsi_exec_args exec_args = { 680 .resid = &resid, 681 .failures = &failures, 682 }; 683 684 *bflags = 0; 685 686 /* Perform up to 3 passes. The first pass uses a conservative 687 * transfer length of 36 unless sdev->inquiry_len specifies a 688 * different value. */ 689 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 690 try_inquiry_len = first_inquiry_len; 691 pass = 1; 692 693 next_pass: 694 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 695 "scsi scan: INQUIRY pass %d length %d\n", 696 pass, try_inquiry_len)); 697 698 /* Each pass gets up to three chances to ignore Unit Attention */ 699 scsi_failures_reset_retries(&failures); 700 701 for (count = 0; count < 3; ++count) { 702 memset(scsi_cmd, 0, 6); 703 scsi_cmd[0] = INQUIRY; 704 scsi_cmd[4] = (unsigned char) try_inquiry_len; 705 706 memset(inq_result, 0, try_inquiry_len); 707 708 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, 709 inq_result, try_inquiry_len, 710 HZ / 2 + HZ * scsi_inq_timeout, 3, 711 &exec_args); 712 713 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 714 "scsi scan: INQUIRY %s with code 0x%x\n", 715 result ? "failed" : "successful", result)); 716 717 if (result == 0) { 718 /* 719 * if nothing was transferred, we try 720 * again. It's a workaround for some USB 721 * devices. 722 */ 723 if (resid == try_inquiry_len) 724 continue; 725 } 726 break; 727 } 728 729 if (result == 0) { 730 scsi_sanitize_inquiry_string(&inq_result[8], 8); 731 scsi_sanitize_inquiry_string(&inq_result[16], 16); 732 scsi_sanitize_inquiry_string(&inq_result[32], 4); 733 734 response_len = inq_result[4] + 5; 735 if (response_len > 255) 736 response_len = first_inquiry_len; /* sanity */ 737 738 /* 739 * Get any flags for this device. 740 * 741 * XXX add a bflags to scsi_device, and replace the 742 * corresponding bit fields in scsi_device, so bflags 743 * need not be passed as an argument. 744 */ 745 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 746 &inq_result[16]); 747 748 /* When the first pass succeeds we gain information about 749 * what larger transfer lengths might work. */ 750 if (pass == 1) { 751 if (BLIST_INQUIRY_36 & *bflags) 752 next_inquiry_len = 36; 753 /* 754 * LLD specified a maximum sdev->inquiry_len 755 * but device claims it has more data. Capping 756 * the length only makes sense for legacy 757 * devices. If a device supports SPC-4 (2014) 758 * or newer, assume that it is safe to ask for 759 * as much as the device says it supports. 760 */ 761 else if (sdev->inquiry_len && 762 response_len > sdev->inquiry_len && 763 (inq_result[2] & 0x7) < 6) /* SPC-4 */ 764 next_inquiry_len = sdev->inquiry_len; 765 else 766 next_inquiry_len = response_len; 767 768 /* If more data is available perform the second pass */ 769 if (next_inquiry_len > try_inquiry_len) { 770 try_inquiry_len = next_inquiry_len; 771 pass = 2; 772 goto next_pass; 773 } 774 } 775 776 } else if (pass == 2) { 777 sdev_printk(KERN_INFO, sdev, 778 "scsi scan: %d byte inquiry failed. " 779 "Consider BLIST_INQUIRY_36 for this device\n", 780 try_inquiry_len); 781 782 /* If this pass failed, the third pass goes back and transfers 783 * the same amount as we successfully got in the first pass. */ 784 try_inquiry_len = first_inquiry_len; 785 pass = 3; 786 goto next_pass; 787 } 788 789 /* If the last transfer attempt got an error, assume the 790 * peripheral doesn't exist or is dead. */ 791 if (result) 792 return -EIO; 793 794 /* Don't report any more data than the device says is valid */ 795 sdev->inquiry_len = min(try_inquiry_len, response_len); 796 797 /* 798 * XXX Abort if the response length is less than 36? If less than 799 * 32, the lookup of the device flags (above) could be invalid, 800 * and it would be possible to take an incorrect action - we do 801 * not want to hang because of a short INQUIRY. On the flip side, 802 * if the device is spun down or becoming ready (and so it gives a 803 * short INQUIRY), an abort here prevents any further use of the 804 * device, including spin up. 805 * 806 * On the whole, the best approach seems to be to assume the first 807 * 36 bytes are valid no matter what the device says. That's 808 * better than copying < 36 bytes to the inquiry-result buffer 809 * and displaying garbage for the Vendor, Product, or Revision 810 * strings. 811 */ 812 if (sdev->inquiry_len < 36) { 813 if (!sdev->host->short_inquiry) { 814 shost_printk(KERN_INFO, sdev->host, 815 "scsi scan: INQUIRY result too short (%d)," 816 " using 36\n", sdev->inquiry_len); 817 sdev->host->short_inquiry = 1; 818 } 819 sdev->inquiry_len = 36; 820 } 821 822 /* 823 * Related to the above issue: 824 * 825 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 826 * and if not ready, sent a START_STOP to start (maybe spin up) and 827 * then send the INQUIRY again, since the INQUIRY can change after 828 * a device is initialized. 829 * 830 * Ideally, start a device if explicitly asked to do so. This 831 * assumes that a device is spun up on power on, spun down on 832 * request, and then spun up on request. 833 */ 834 835 /* 836 * The scanning code needs to know the scsi_level, even if no 837 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 838 * non-zero LUNs can be scanned. 839 */ 840 sdev->scsi_level = inq_result[2] & 0x0f; 841 if (sdev->scsi_level >= 2 || 842 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 843 sdev->scsi_level++; 844 sdev->sdev_target->scsi_level = sdev->scsi_level; 845 846 /* 847 * If SCSI-2 or lower, and if the transport requires it, 848 * store the LUN value in CDB[1]. 849 */ 850 sdev->lun_in_cdb = 0; 851 if (sdev->scsi_level <= SCSI_2 && 852 sdev->scsi_level != SCSI_UNKNOWN && 853 !sdev->host->no_scsi2_lun_in_cdb) 854 sdev->lun_in_cdb = 1; 855 856 return 0; 857 } 858 859 /** 860 * scsi_add_lun - allocate and fully initialze a scsi_device 861 * @sdev: holds information to be stored in the new scsi_device 862 * @inq_result: holds the result of a previous INQUIRY to the LUN 863 * @bflags: black/white list flag 864 * @async: 1 if this device is being scanned asynchronously 865 * 866 * Description: 867 * Initialize the scsi_device @sdev. Optionally set fields based 868 * on values in *@bflags. 869 * 870 * Return: 871 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 872 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 873 **/ 874 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 875 blist_flags_t *bflags, int async) 876 { 877 const struct scsi_host_template *hostt = sdev->host->hostt; 878 struct queue_limits lim; 879 int ret; 880 881 /* 882 * XXX do not save the inquiry, since it can change underneath us, 883 * save just vendor/model/rev. 884 * 885 * Rather than save it and have an ioctl that retrieves the saved 886 * value, have an ioctl that executes the same INQUIRY code used 887 * in scsi_probe_lun, let user level programs doing INQUIRY 888 * scanning run at their own risk, or supply a user level program 889 * that can correctly scan. 890 */ 891 892 /* 893 * Copy at least 36 bytes of INQUIRY data, so that we don't 894 * dereference unallocated memory when accessing the Vendor, 895 * Product, and Revision strings. Badly behaved devices may set 896 * the INQUIRY Additional Length byte to a small value, indicating 897 * these strings are invalid, but often they contain plausible data 898 * nonetheless. It doesn't matter if the device sent < 36 bytes 899 * total, since scsi_probe_lun() initializes inq_result with 0s. 900 */ 901 sdev->inquiry = kmemdup(inq_result, 902 max_t(size_t, sdev->inquiry_len, 36), 903 GFP_KERNEL); 904 if (sdev->inquiry == NULL) 905 return SCSI_SCAN_NO_RESPONSE; 906 907 sdev->vendor = (char *) (sdev->inquiry + 8); 908 sdev->model = (char *) (sdev->inquiry + 16); 909 sdev->rev = (char *) (sdev->inquiry + 32); 910 911 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 912 /* 913 * sata emulation layer device. This is a hack to work around 914 * the SATL power management specifications which state that 915 * when the SATL detects the device has gone into standby 916 * mode, it shall respond with NOT READY. 917 */ 918 sdev->allow_restart = 1; 919 } 920 921 if (*bflags & BLIST_ISROM) { 922 sdev->type = TYPE_ROM; 923 sdev->removable = 1; 924 } else { 925 sdev->type = (inq_result[0] & 0x1f); 926 sdev->removable = (inq_result[1] & 0x80) >> 7; 927 928 /* 929 * some devices may respond with wrong type for 930 * well-known logical units. Force well-known type 931 * to enumerate them correctly. 932 */ 933 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 934 sdev_printk(KERN_WARNING, sdev, 935 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 936 __func__, sdev->type, (unsigned int)sdev->lun); 937 sdev->type = TYPE_WLUN; 938 } 939 940 } 941 942 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 943 /* RBC and MMC devices can return SCSI-3 compliance and yet 944 * still not support REPORT LUNS, so make them act as 945 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 946 * specifically set */ 947 if ((*bflags & BLIST_REPORTLUN2) == 0) 948 *bflags |= BLIST_NOREPORTLUN; 949 } 950 951 /* 952 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 953 * spec says: The device server is capable of supporting the 954 * specified peripheral device type on this logical unit. However, 955 * the physical device is not currently connected to this logical 956 * unit. 957 * 958 * The above is vague, as it implies that we could treat 001 and 959 * 011 the same. Stay compatible with previous code, and create a 960 * scsi_device for a PQ of 1 961 * 962 * Don't set the device offline here; rather let the upper 963 * level drivers eval the PQ to decide whether they should 964 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 965 */ 966 967 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 968 sdev->lockable = sdev->removable; 969 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 970 971 if (sdev->scsi_level >= SCSI_3 || 972 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 973 sdev->ppr = 1; 974 if (inq_result[7] & 0x60) 975 sdev->wdtr = 1; 976 if (inq_result[7] & 0x10) 977 sdev->sdtr = 1; 978 979 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 980 "ANSI: %d%s\n", scsi_device_type(sdev->type), 981 sdev->vendor, sdev->model, sdev->rev, 982 sdev->inq_periph_qual, inq_result[2] & 0x07, 983 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 984 985 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 986 !(*bflags & BLIST_NOTQ)) { 987 sdev->tagged_supported = 1; 988 sdev->simple_tags = 1; 989 } 990 991 /* 992 * Some devices (Texel CD ROM drives) have handshaking problems 993 * when used with the Seagate controllers. borken is initialized 994 * to 1, and then set it to 0 here. 995 */ 996 if ((*bflags & BLIST_BORKEN) == 0) 997 sdev->borken = 0; 998 999 if (*bflags & BLIST_NO_ULD_ATTACH) 1000 sdev->no_uld_attach = 1; 1001 1002 /* 1003 * Apparently some really broken devices (contrary to the SCSI 1004 * standards) need to be selected without asserting ATN 1005 */ 1006 if (*bflags & BLIST_SELECT_NO_ATN) 1007 sdev->select_no_atn = 1; 1008 1009 /* 1010 * Some devices may not want to have a start command automatically 1011 * issued when a device is added. 1012 */ 1013 if (*bflags & BLIST_NOSTARTONADD) 1014 sdev->no_start_on_add = 1; 1015 1016 if (*bflags & BLIST_SINGLELUN) 1017 scsi_target(sdev)->single_lun = 1; 1018 1019 sdev->use_10_for_rw = 1; 1020 1021 /* some devices don't like REPORT SUPPORTED OPERATION CODES 1022 * and will simply timeout causing sd_mod init to take a very 1023 * very long time */ 1024 if (*bflags & BLIST_NO_RSOC) 1025 sdev->no_report_opcodes = 1; 1026 1027 /* set the device running here so that slave configure 1028 * may do I/O */ 1029 mutex_lock(&sdev->state_mutex); 1030 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 1031 if (ret) 1032 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 1033 mutex_unlock(&sdev->state_mutex); 1034 1035 if (ret) { 1036 sdev_printk(KERN_ERR, sdev, 1037 "in wrong state %s to complete scan\n", 1038 scsi_device_state_name(sdev->sdev_state)); 1039 return SCSI_SCAN_NO_RESPONSE; 1040 } 1041 1042 if (*bflags & BLIST_NOT_LOCKABLE) 1043 sdev->lockable = 0; 1044 1045 if (*bflags & BLIST_RETRY_HWERROR) 1046 sdev->retry_hwerror = 1; 1047 1048 if (*bflags & BLIST_NO_DIF) 1049 sdev->no_dif = 1; 1050 1051 if (*bflags & BLIST_UNMAP_LIMIT_WS) 1052 sdev->unmap_limit_for_ws = 1; 1053 1054 if (*bflags & BLIST_IGN_MEDIA_CHANGE) 1055 sdev->ignore_media_change = 1; 1056 1057 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 1058 1059 if (*bflags & BLIST_TRY_VPD_PAGES) 1060 sdev->try_vpd_pages = 1; 1061 else if (*bflags & BLIST_SKIP_VPD_PAGES) 1062 sdev->skip_vpd_pages = 1; 1063 1064 if (*bflags & BLIST_NO_VPD_SIZE) 1065 sdev->no_vpd_size = 1; 1066 1067 transport_configure_device(&sdev->sdev_gendev); 1068 1069 /* 1070 * No need to freeze the queue as it isn't reachable to anyone else yet. 1071 */ 1072 lim = queue_limits_start_update(sdev->request_queue); 1073 if (*bflags & BLIST_MAX_512) 1074 lim.max_hw_sectors = 512; 1075 else if (*bflags & BLIST_MAX_1024) 1076 lim.max_hw_sectors = 1024; 1077 1078 if (hostt->device_configure) 1079 ret = hostt->device_configure(sdev, &lim); 1080 else if (hostt->slave_configure) 1081 ret = hostt->slave_configure(sdev); 1082 if (ret) { 1083 queue_limits_cancel_update(sdev->request_queue); 1084 /* 1085 * If the LLDD reports device not present, don't clutter the 1086 * console with failure messages. 1087 */ 1088 if (ret != -ENXIO) 1089 sdev_printk(KERN_ERR, sdev, 1090 "failed to configure device\n"); 1091 return SCSI_SCAN_NO_RESPONSE; 1092 } 1093 1094 ret = queue_limits_commit_update(sdev->request_queue, &lim); 1095 if (ret) { 1096 sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n"); 1097 return SCSI_SCAN_NO_RESPONSE; 1098 } 1099 1100 /* 1101 * The queue_depth is often changed in ->device_configure. 1102 * 1103 * Set up budget map again since memory consumption of the map depends 1104 * on actual queue depth. 1105 */ 1106 if (hostt->device_configure || hostt->slave_configure) 1107 scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth); 1108 1109 if (sdev->scsi_level >= SCSI_3) 1110 scsi_attach_vpd(sdev); 1111 1112 scsi_cdl_check(sdev); 1113 1114 sdev->max_queue_depth = sdev->queue_depth; 1115 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); 1116 sdev->sdev_bflags = *bflags; 1117 1118 /* 1119 * Ok, the device is now all set up, we can 1120 * register it and tell the rest of the kernel 1121 * about it. 1122 */ 1123 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 1124 return SCSI_SCAN_NO_RESPONSE; 1125 1126 return SCSI_SCAN_LUN_PRESENT; 1127 } 1128 1129 #ifdef CONFIG_SCSI_LOGGING 1130 /** 1131 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1132 * @buf: Output buffer with at least end-first+1 bytes of space 1133 * @inq: Inquiry buffer (input) 1134 * @first: Offset of string into inq 1135 * @end: Index after last character in inq 1136 */ 1137 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1138 unsigned first, unsigned end) 1139 { 1140 unsigned term = 0, idx; 1141 1142 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1143 if (inq[idx+first] > ' ') { 1144 buf[idx] = inq[idx+first]; 1145 term = idx+1; 1146 } else { 1147 buf[idx] = ' '; 1148 } 1149 } 1150 buf[term] = 0; 1151 return buf; 1152 } 1153 #endif 1154 1155 /** 1156 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1157 * @starget: pointer to target device structure 1158 * @lun: LUN of target device 1159 * @bflagsp: store bflags here if not NULL 1160 * @sdevp: probe the LUN corresponding to this scsi_device 1161 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1162 * needed on first scan 1163 * @hostdata: passed to scsi_alloc_sdev() 1164 * 1165 * Description: 1166 * Call scsi_probe_lun, if a LUN with an attached device is found, 1167 * allocate and set it up by calling scsi_add_lun. 1168 * 1169 * Return: 1170 * 1171 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1172 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1173 * attached at the LUN 1174 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1175 **/ 1176 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1177 u64 lun, blist_flags_t *bflagsp, 1178 struct scsi_device **sdevp, 1179 enum scsi_scan_mode rescan, 1180 void *hostdata) 1181 { 1182 struct scsi_device *sdev; 1183 unsigned char *result; 1184 blist_flags_t bflags; 1185 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1186 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1187 1188 /* 1189 * The rescan flag is used as an optimization, the first scan of a 1190 * host adapter calls into here with rescan == 0. 1191 */ 1192 sdev = scsi_device_lookup_by_target(starget, lun); 1193 if (sdev) { 1194 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1195 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1196 "scsi scan: device exists on %s\n", 1197 dev_name(&sdev->sdev_gendev))); 1198 if (sdevp) 1199 *sdevp = sdev; 1200 else 1201 scsi_device_put(sdev); 1202 1203 if (bflagsp) 1204 *bflagsp = scsi_get_device_flags(sdev, 1205 sdev->vendor, 1206 sdev->model); 1207 return SCSI_SCAN_LUN_PRESENT; 1208 } 1209 scsi_device_put(sdev); 1210 } else 1211 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1212 if (!sdev) 1213 goto out; 1214 1215 result = kmalloc(result_len, GFP_KERNEL); 1216 if (!result) 1217 goto out_free_sdev; 1218 1219 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1220 goto out_free_result; 1221 1222 if (bflagsp) 1223 *bflagsp = bflags; 1224 /* 1225 * result contains valid SCSI INQUIRY data. 1226 */ 1227 if ((result[0] >> 5) == 3) { 1228 /* 1229 * For a Peripheral qualifier 3 (011b), the SCSI 1230 * spec says: The device server is not capable of 1231 * supporting a physical device on this logical 1232 * unit. 1233 * 1234 * For disks, this implies that there is no 1235 * logical disk configured at sdev->lun, but there 1236 * is a target id responding. 1237 */ 1238 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1239 " peripheral qualifier of 3, device not" 1240 " added\n")) 1241 if (lun == 0) { 1242 SCSI_LOG_SCAN_BUS(1, { 1243 unsigned char vend[9]; 1244 unsigned char mod[17]; 1245 1246 sdev_printk(KERN_INFO, sdev, 1247 "scsi scan: consider passing scsi_mod." 1248 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1249 scsi_inq_str(vend, result, 8, 16), 1250 scsi_inq_str(mod, result, 16, 32)); 1251 }); 1252 1253 } 1254 1255 res = SCSI_SCAN_TARGET_PRESENT; 1256 goto out_free_result; 1257 } 1258 1259 /* 1260 * Some targets may set slight variations of PQ and PDT to signal 1261 * that no LUN is present, so don't add sdev in these cases. 1262 * Two specific examples are: 1263 * 1) NetApp targets: return PQ=1, PDT=0x1f 1264 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1265 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1266 * 1267 * References: 1268 * 1) SCSI SPC-3, pp. 145-146 1269 * PQ=1: "A peripheral device having the specified peripheral 1270 * device type is not connected to this logical unit. However, the 1271 * device server is capable of supporting the specified peripheral 1272 * device type on this logical unit." 1273 * PDT=0x1f: "Unknown or no device type" 1274 * 2) USB UFI 1.0, p. 20 1275 * PDT=00h Direct-access device (floppy) 1276 * PDT=1Fh none (no FDD connected to the requested logical unit) 1277 */ 1278 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1279 (result[0] & 0x1f) == 0x1f && 1280 !scsi_is_wlun(lun)) { 1281 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1282 "scsi scan: peripheral device type" 1283 " of 31, no device added\n")); 1284 res = SCSI_SCAN_TARGET_PRESENT; 1285 goto out_free_result; 1286 } 1287 1288 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1289 if (res == SCSI_SCAN_LUN_PRESENT) { 1290 if (bflags & BLIST_KEY) { 1291 sdev->lockable = 0; 1292 scsi_unlock_floptical(sdev, result); 1293 } 1294 } 1295 1296 out_free_result: 1297 kfree(result); 1298 out_free_sdev: 1299 if (res == SCSI_SCAN_LUN_PRESENT) { 1300 if (sdevp) { 1301 if (scsi_device_get(sdev) == 0) { 1302 *sdevp = sdev; 1303 } else { 1304 __scsi_remove_device(sdev); 1305 res = SCSI_SCAN_NO_RESPONSE; 1306 } 1307 } 1308 } else 1309 __scsi_remove_device(sdev); 1310 out: 1311 return res; 1312 } 1313 1314 /** 1315 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1316 * @starget: pointer to target structure to scan 1317 * @bflags: black/white list flag for LUN 0 1318 * @scsi_level: Which version of the standard does this device adhere to 1319 * @rescan: passed to scsi_probe_add_lun() 1320 * 1321 * Description: 1322 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1323 * scanned) to some maximum lun until a LUN is found with no device 1324 * attached. Use the bflags to figure out any oddities. 1325 * 1326 * Modifies sdevscan->lun. 1327 **/ 1328 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1329 blist_flags_t bflags, int scsi_level, 1330 enum scsi_scan_mode rescan) 1331 { 1332 uint max_dev_lun; 1333 u64 sparse_lun, lun; 1334 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1335 1336 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1337 "scsi scan: Sequential scan\n")); 1338 1339 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1340 /* 1341 * If this device is known to support sparse multiple units, 1342 * override the other settings, and scan all of them. Normally, 1343 * SCSI-3 devices should be scanned via the REPORT LUNS. 1344 */ 1345 if (bflags & BLIST_SPARSELUN) { 1346 max_dev_lun = shost->max_lun; 1347 sparse_lun = 1; 1348 } else 1349 sparse_lun = 0; 1350 1351 /* 1352 * If less than SCSI_1_CCS, and no special lun scanning, stop 1353 * scanning; this matches 2.4 behaviour, but could just be a bug 1354 * (to continue scanning a SCSI_1_CCS device). 1355 * 1356 * This test is broken. We might not have any device on lun0 for 1357 * a sparselun device, and if that's the case then how would we 1358 * know the real scsi_level, eh? It might make sense to just not 1359 * scan any SCSI_1 device for non-0 luns, but that check would best 1360 * go into scsi_alloc_sdev() and just have it return null when asked 1361 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1362 * 1363 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1364 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1365 == 0)) 1366 return; 1367 */ 1368 /* 1369 * If this device is known to support multiple units, override 1370 * the other settings, and scan all of them. 1371 */ 1372 if (bflags & BLIST_FORCELUN) 1373 max_dev_lun = shost->max_lun; 1374 /* 1375 * REGAL CDC-4X: avoid hang after LUN 4 1376 */ 1377 if (bflags & BLIST_MAX5LUN) 1378 max_dev_lun = min(5U, max_dev_lun); 1379 /* 1380 * Do not scan SCSI-2 or lower device past LUN 7, unless 1381 * BLIST_LARGELUN. 1382 */ 1383 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1384 max_dev_lun = min(8U, max_dev_lun); 1385 else 1386 max_dev_lun = min(256U, max_dev_lun); 1387 1388 /* 1389 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1390 * until we reach the max, or no LUN is found and we are not 1391 * sparse_lun. 1392 */ 1393 for (lun = 1; lun < max_dev_lun; ++lun) 1394 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1395 NULL) != SCSI_SCAN_LUN_PRESENT) && 1396 !sparse_lun) 1397 return; 1398 } 1399 1400 /** 1401 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1402 * @starget: which target 1403 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1404 * @rescan: nonzero if we can skip code only needed on first scan 1405 * 1406 * Description: 1407 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1408 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1409 * 1410 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1411 * LUNs even if it's older than SCSI-3. 1412 * If BLIST_NOREPORTLUN is set, return 1 always. 1413 * If BLIST_NOLUN is set, return 0 always. 1414 * If starget->no_report_luns is set, return 1 always. 1415 * 1416 * Return: 1417 * 0: scan completed (or no memory, so further scanning is futile) 1418 * 1: could not scan with REPORT LUN 1419 **/ 1420 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1421 enum scsi_scan_mode rescan) 1422 { 1423 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1424 unsigned int length; 1425 u64 lun; 1426 unsigned int num_luns; 1427 int result; 1428 struct scsi_lun *lunp, *lun_data; 1429 struct scsi_device *sdev; 1430 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1431 struct scsi_failure failure_defs[] = { 1432 { 1433 .sense = UNIT_ATTENTION, 1434 .asc = SCMD_FAILURE_ASC_ANY, 1435 .ascq = SCMD_FAILURE_ASCQ_ANY, 1436 .result = SAM_STAT_CHECK_CONDITION, 1437 }, 1438 /* Fail all CCs except the UA above */ 1439 { 1440 .sense = SCMD_FAILURE_SENSE_ANY, 1441 .result = SAM_STAT_CHECK_CONDITION, 1442 }, 1443 /* Retry any other errors not listed above */ 1444 { 1445 .result = SCMD_FAILURE_RESULT_ANY, 1446 }, 1447 {} 1448 }; 1449 struct scsi_failures failures = { 1450 .total_allowed = 3, 1451 .failure_definitions = failure_defs, 1452 }; 1453 const struct scsi_exec_args exec_args = { 1454 .failures = &failures, 1455 }; 1456 int ret = 0; 1457 1458 /* 1459 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1460 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1461 * support more than 8 LUNs. 1462 * Don't attempt if the target doesn't support REPORT LUNS. 1463 */ 1464 if (bflags & BLIST_NOREPORTLUN) 1465 return 1; 1466 if (starget->scsi_level < SCSI_2 && 1467 starget->scsi_level != SCSI_UNKNOWN) 1468 return 1; 1469 if (starget->scsi_level < SCSI_3 && 1470 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1471 return 1; 1472 if (bflags & BLIST_NOLUN) 1473 return 0; 1474 if (starget->no_report_luns) 1475 return 1; 1476 1477 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1478 sdev = scsi_alloc_sdev(starget, 0, NULL); 1479 if (!sdev) 1480 return 0; 1481 if (scsi_device_get(sdev)) { 1482 __scsi_remove_device(sdev); 1483 return 0; 1484 } 1485 } 1486 1487 /* 1488 * Allocate enough to hold the header (the same size as one scsi_lun) 1489 * plus the number of luns we are requesting. 511 was the default 1490 * value of the now removed max_report_luns parameter. 1491 */ 1492 length = (511 + 1) * sizeof(struct scsi_lun); 1493 retry: 1494 lun_data = kmalloc(length, GFP_KERNEL); 1495 if (!lun_data) { 1496 printk(ALLOC_FAILURE_MSG, __func__); 1497 goto out; 1498 } 1499 1500 scsi_cmd[0] = REPORT_LUNS; 1501 1502 /* 1503 * bytes 1 - 5: reserved, set to zero. 1504 */ 1505 memset(&scsi_cmd[1], 0, 5); 1506 1507 /* 1508 * bytes 6 - 9: length of the command. 1509 */ 1510 put_unaligned_be32(length, &scsi_cmd[6]); 1511 1512 scsi_cmd[10] = 0; /* reserved */ 1513 scsi_cmd[11] = 0; /* control */ 1514 1515 /* 1516 * We can get a UNIT ATTENTION, for example a power on/reset, so 1517 * retry a few times (like sd.c does for TEST UNIT READY). 1518 * Experience shows some combinations of adapter/devices get at 1519 * least two power on/resets. 1520 * 1521 * Illegal requests (for devices that do not support REPORT LUNS) 1522 * should come through as a check condition, and will not generate 1523 * a retry. 1524 */ 1525 scsi_failures_reset_retries(&failures); 1526 1527 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1528 "scsi scan: Sending REPORT LUNS\n")); 1529 1530 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data, 1531 length, SCSI_REPORT_LUNS_TIMEOUT, 3, 1532 &exec_args); 1533 1534 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1535 "scsi scan: REPORT LUNS %s result 0x%x\n", 1536 result ? "failed" : "successful", result)); 1537 if (result) { 1538 /* 1539 * The device probably does not support a REPORT LUN command 1540 */ 1541 ret = 1; 1542 goto out_err; 1543 } 1544 1545 /* 1546 * Get the length from the first four bytes of lun_data. 1547 */ 1548 if (get_unaligned_be32(lun_data->scsi_lun) + 1549 sizeof(struct scsi_lun) > length) { 1550 length = get_unaligned_be32(lun_data->scsi_lun) + 1551 sizeof(struct scsi_lun); 1552 kfree(lun_data); 1553 goto retry; 1554 } 1555 length = get_unaligned_be32(lun_data->scsi_lun); 1556 1557 num_luns = (length / sizeof(struct scsi_lun)); 1558 1559 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1560 "scsi scan: REPORT LUN scan\n")); 1561 1562 /* 1563 * Scan the luns in lun_data. The entry at offset 0 is really 1564 * the header, so start at 1 and go up to and including num_luns. 1565 */ 1566 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1567 lun = scsilun_to_int(lunp); 1568 1569 if (lun > sdev->host->max_lun) { 1570 sdev_printk(KERN_WARNING, sdev, 1571 "lun%llu has a LUN larger than" 1572 " allowed by the host adapter\n", lun); 1573 } else { 1574 int res; 1575 1576 res = scsi_probe_and_add_lun(starget, 1577 lun, NULL, NULL, rescan, NULL); 1578 if (res == SCSI_SCAN_NO_RESPONSE) { 1579 /* 1580 * Got some results, but now none, abort. 1581 */ 1582 sdev_printk(KERN_ERR, sdev, 1583 "Unexpected response" 1584 " from lun %llu while scanning, scan" 1585 " aborted\n", (unsigned long long)lun); 1586 break; 1587 } 1588 } 1589 } 1590 1591 out_err: 1592 kfree(lun_data); 1593 out: 1594 if (scsi_device_created(sdev)) 1595 /* 1596 * the sdev we used didn't appear in the report luns scan 1597 */ 1598 __scsi_remove_device(sdev); 1599 scsi_device_put(sdev); 1600 return ret; 1601 } 1602 1603 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1604 uint id, u64 lun, void *hostdata) 1605 { 1606 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1607 struct device *parent = &shost->shost_gendev; 1608 struct scsi_target *starget; 1609 1610 if (strncmp(scsi_scan_type, "none", 4) == 0) 1611 return ERR_PTR(-ENODEV); 1612 1613 starget = scsi_alloc_target(parent, channel, id); 1614 if (!starget) 1615 return ERR_PTR(-ENOMEM); 1616 scsi_autopm_get_target(starget); 1617 1618 mutex_lock(&shost->scan_mutex); 1619 if (!shost->async_scan) 1620 scsi_complete_async_scans(); 1621 1622 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1623 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1624 SCSI_SCAN_RESCAN, hostdata); 1625 scsi_autopm_put_host(shost); 1626 } 1627 mutex_unlock(&shost->scan_mutex); 1628 scsi_autopm_put_target(starget); 1629 /* 1630 * paired with scsi_alloc_target(). Target will be destroyed unless 1631 * scsi_probe_and_add_lun made an underlying device visible 1632 */ 1633 scsi_target_reap(starget); 1634 put_device(&starget->dev); 1635 1636 return sdev; 1637 } 1638 EXPORT_SYMBOL(__scsi_add_device); 1639 1640 int scsi_add_device(struct Scsi_Host *host, uint channel, 1641 uint target, u64 lun) 1642 { 1643 struct scsi_device *sdev = 1644 __scsi_add_device(host, channel, target, lun, NULL); 1645 if (IS_ERR(sdev)) 1646 return PTR_ERR(sdev); 1647 1648 scsi_device_put(sdev); 1649 return 0; 1650 } 1651 EXPORT_SYMBOL(scsi_add_device); 1652 1653 int scsi_resume_device(struct scsi_device *sdev) 1654 { 1655 struct device *dev = &sdev->sdev_gendev; 1656 int ret = 0; 1657 1658 device_lock(dev); 1659 1660 /* 1661 * Bail out if the device or its queue are not running. Otherwise, 1662 * the rescan may block waiting for commands to be executed, with us 1663 * holding the device lock. This can result in a potential deadlock 1664 * in the power management core code when system resume is on-going. 1665 */ 1666 if (sdev->sdev_state != SDEV_RUNNING || 1667 blk_queue_pm_only(sdev->request_queue)) { 1668 ret = -EWOULDBLOCK; 1669 goto unlock; 1670 } 1671 1672 if (dev->driver && try_module_get(dev->driver->owner)) { 1673 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1674 1675 if (drv->resume) 1676 ret = drv->resume(dev); 1677 module_put(dev->driver->owner); 1678 } 1679 1680 unlock: 1681 device_unlock(dev); 1682 1683 return ret; 1684 } 1685 EXPORT_SYMBOL(scsi_resume_device); 1686 1687 int scsi_rescan_device(struct scsi_device *sdev) 1688 { 1689 struct device *dev = &sdev->sdev_gendev; 1690 int ret = 0; 1691 1692 device_lock(dev); 1693 1694 /* 1695 * Bail out if the device or its queue are not running. Otherwise, 1696 * the rescan may block waiting for commands to be executed, with us 1697 * holding the device lock. This can result in a potential deadlock 1698 * in the power management core code when system resume is on-going. 1699 */ 1700 if (sdev->sdev_state != SDEV_RUNNING || 1701 blk_queue_pm_only(sdev->request_queue)) { 1702 ret = -EWOULDBLOCK; 1703 goto unlock; 1704 } 1705 1706 scsi_attach_vpd(sdev); 1707 scsi_cdl_check(sdev); 1708 1709 if (sdev->handler && sdev->handler->rescan) 1710 sdev->handler->rescan(sdev); 1711 1712 if (dev->driver && try_module_get(dev->driver->owner)) { 1713 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1714 1715 if (drv->rescan) 1716 drv->rescan(dev); 1717 module_put(dev->driver->owner); 1718 } 1719 1720 unlock: 1721 device_unlock(dev); 1722 1723 return ret; 1724 } 1725 EXPORT_SYMBOL(scsi_rescan_device); 1726 1727 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1728 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1729 { 1730 struct Scsi_Host *shost = dev_to_shost(parent); 1731 blist_flags_t bflags = 0; 1732 int res; 1733 struct scsi_target *starget; 1734 1735 if (shost->this_id == id) 1736 /* 1737 * Don't scan the host adapter 1738 */ 1739 return; 1740 1741 starget = scsi_alloc_target(parent, channel, id); 1742 if (!starget) 1743 return; 1744 scsi_autopm_get_target(starget); 1745 1746 if (lun != SCAN_WILD_CARD) { 1747 /* 1748 * Scan for a specific host/chan/id/lun. 1749 */ 1750 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1751 goto out_reap; 1752 } 1753 1754 /* 1755 * Scan LUN 0, if there is some response, scan further. Ideally, we 1756 * would not configure LUN 0 until all LUNs are scanned. 1757 */ 1758 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1759 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1760 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1761 /* 1762 * The REPORT LUN did not scan the target, 1763 * do a sequential scan. 1764 */ 1765 scsi_sequential_lun_scan(starget, bflags, 1766 starget->scsi_level, rescan); 1767 } 1768 1769 out_reap: 1770 scsi_autopm_put_target(starget); 1771 /* 1772 * paired with scsi_alloc_target(): determine if the target has 1773 * any children at all and if not, nuke it 1774 */ 1775 scsi_target_reap(starget); 1776 1777 put_device(&starget->dev); 1778 } 1779 1780 /** 1781 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1782 * @parent: host to scan 1783 * @channel: channel to scan 1784 * @id: target id to scan 1785 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1786 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1787 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1788 * and SCSI_SCAN_MANUAL to force scanning even if 1789 * 'scan=manual' is set. 1790 * 1791 * Description: 1792 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1793 * and possibly all LUNs on the target id. 1794 * 1795 * First try a REPORT LUN scan, if that does not scan the target, do a 1796 * sequential scan of LUNs on the target id. 1797 **/ 1798 void scsi_scan_target(struct device *parent, unsigned int channel, 1799 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1800 { 1801 struct Scsi_Host *shost = dev_to_shost(parent); 1802 1803 if (strncmp(scsi_scan_type, "none", 4) == 0) 1804 return; 1805 1806 if (rescan != SCSI_SCAN_MANUAL && 1807 strncmp(scsi_scan_type, "manual", 6) == 0) 1808 return; 1809 1810 mutex_lock(&shost->scan_mutex); 1811 if (!shost->async_scan) 1812 scsi_complete_async_scans(); 1813 1814 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1815 __scsi_scan_target(parent, channel, id, lun, rescan); 1816 scsi_autopm_put_host(shost); 1817 } 1818 mutex_unlock(&shost->scan_mutex); 1819 } 1820 EXPORT_SYMBOL(scsi_scan_target); 1821 1822 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1823 unsigned int id, u64 lun, 1824 enum scsi_scan_mode rescan) 1825 { 1826 uint order_id; 1827 1828 if (id == SCAN_WILD_CARD) 1829 for (id = 0; id < shost->max_id; ++id) { 1830 /* 1831 * XXX adapter drivers when possible (FCP, iSCSI) 1832 * could modify max_id to match the current max, 1833 * not the absolute max. 1834 * 1835 * XXX add a shost id iterator, so for example, 1836 * the FC ID can be the same as a target id 1837 * without a huge overhead of sparse id's. 1838 */ 1839 if (shost->reverse_ordering) 1840 /* 1841 * Scan from high to low id. 1842 */ 1843 order_id = shost->max_id - id - 1; 1844 else 1845 order_id = id; 1846 __scsi_scan_target(&shost->shost_gendev, channel, 1847 order_id, lun, rescan); 1848 } 1849 else 1850 __scsi_scan_target(&shost->shost_gendev, channel, 1851 id, lun, rescan); 1852 } 1853 1854 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1855 unsigned int id, u64 lun, 1856 enum scsi_scan_mode rescan) 1857 { 1858 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1859 "%s: <%u:%u:%llu>\n", 1860 __func__, channel, id, lun)); 1861 1862 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1863 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1864 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1865 return -EINVAL; 1866 1867 mutex_lock(&shost->scan_mutex); 1868 if (!shost->async_scan) 1869 scsi_complete_async_scans(); 1870 1871 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1872 if (channel == SCAN_WILD_CARD) 1873 for (channel = 0; channel <= shost->max_channel; 1874 channel++) 1875 scsi_scan_channel(shost, channel, id, lun, 1876 rescan); 1877 else 1878 scsi_scan_channel(shost, channel, id, lun, rescan); 1879 scsi_autopm_put_host(shost); 1880 } 1881 mutex_unlock(&shost->scan_mutex); 1882 1883 return 0; 1884 } 1885 1886 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1887 { 1888 struct scsi_device *sdev; 1889 shost_for_each_device(sdev, shost) { 1890 /* target removed before the device could be added */ 1891 if (sdev->sdev_state == SDEV_DEL) 1892 continue; 1893 /* If device is already visible, skip adding it to sysfs */ 1894 if (sdev->is_visible) 1895 continue; 1896 if (!scsi_host_scan_allowed(shost) || 1897 scsi_sysfs_add_sdev(sdev) != 0) 1898 __scsi_remove_device(sdev); 1899 } 1900 } 1901 1902 /** 1903 * scsi_prep_async_scan - prepare for an async scan 1904 * @shost: the host which will be scanned 1905 * Returns: a cookie to be passed to scsi_finish_async_scan() 1906 * 1907 * Tells the midlayer this host is going to do an asynchronous scan. 1908 * It reserves the host's position in the scanning list and ensures 1909 * that other asynchronous scans started after this one won't affect the 1910 * ordering of the discovered devices. 1911 */ 1912 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1913 { 1914 struct async_scan_data *data = NULL; 1915 unsigned long flags; 1916 1917 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1918 return NULL; 1919 1920 mutex_lock(&shost->scan_mutex); 1921 if (shost->async_scan) { 1922 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1923 goto err; 1924 } 1925 1926 data = kmalloc(sizeof(*data), GFP_KERNEL); 1927 if (!data) 1928 goto err; 1929 data->shost = scsi_host_get(shost); 1930 if (!data->shost) 1931 goto err; 1932 init_completion(&data->prev_finished); 1933 1934 spin_lock_irqsave(shost->host_lock, flags); 1935 shost->async_scan = 1; 1936 spin_unlock_irqrestore(shost->host_lock, flags); 1937 mutex_unlock(&shost->scan_mutex); 1938 1939 spin_lock(&async_scan_lock); 1940 if (list_empty(&scanning_hosts)) 1941 complete(&data->prev_finished); 1942 list_add_tail(&data->list, &scanning_hosts); 1943 spin_unlock(&async_scan_lock); 1944 1945 return data; 1946 1947 err: 1948 mutex_unlock(&shost->scan_mutex); 1949 kfree(data); 1950 return NULL; 1951 } 1952 1953 /** 1954 * scsi_finish_async_scan - asynchronous scan has finished 1955 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1956 * 1957 * All the devices currently attached to this host have been found. 1958 * This function announces all the devices it has found to the rest 1959 * of the system. 1960 */ 1961 static void scsi_finish_async_scan(struct async_scan_data *data) 1962 { 1963 struct Scsi_Host *shost; 1964 unsigned long flags; 1965 1966 if (!data) 1967 return; 1968 1969 shost = data->shost; 1970 1971 mutex_lock(&shost->scan_mutex); 1972 1973 if (!shost->async_scan) { 1974 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1975 dump_stack(); 1976 mutex_unlock(&shost->scan_mutex); 1977 return; 1978 } 1979 1980 wait_for_completion(&data->prev_finished); 1981 1982 scsi_sysfs_add_devices(shost); 1983 1984 spin_lock_irqsave(shost->host_lock, flags); 1985 shost->async_scan = 0; 1986 spin_unlock_irqrestore(shost->host_lock, flags); 1987 1988 mutex_unlock(&shost->scan_mutex); 1989 1990 spin_lock(&async_scan_lock); 1991 list_del(&data->list); 1992 if (!list_empty(&scanning_hosts)) { 1993 struct async_scan_data *next = list_entry(scanning_hosts.next, 1994 struct async_scan_data, list); 1995 complete(&next->prev_finished); 1996 } 1997 spin_unlock(&async_scan_lock); 1998 1999 scsi_autopm_put_host(shost); 2000 scsi_host_put(shost); 2001 kfree(data); 2002 } 2003 2004 static void do_scsi_scan_host(struct Scsi_Host *shost) 2005 { 2006 if (shost->hostt->scan_finished) { 2007 unsigned long start = jiffies; 2008 if (shost->hostt->scan_start) 2009 shost->hostt->scan_start(shost); 2010 2011 while (!shost->hostt->scan_finished(shost, jiffies - start)) 2012 msleep(10); 2013 } else { 2014 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 2015 SCAN_WILD_CARD, SCSI_SCAN_INITIAL); 2016 } 2017 } 2018 2019 static void do_scan_async(void *_data, async_cookie_t c) 2020 { 2021 struct async_scan_data *data = _data; 2022 struct Scsi_Host *shost = data->shost; 2023 2024 do_scsi_scan_host(shost); 2025 scsi_finish_async_scan(data); 2026 } 2027 2028 /** 2029 * scsi_scan_host - scan the given adapter 2030 * @shost: adapter to scan 2031 **/ 2032 void scsi_scan_host(struct Scsi_Host *shost) 2033 { 2034 struct async_scan_data *data; 2035 2036 if (strncmp(scsi_scan_type, "none", 4) == 0 || 2037 strncmp(scsi_scan_type, "manual", 6) == 0) 2038 return; 2039 if (scsi_autopm_get_host(shost) < 0) 2040 return; 2041 2042 data = scsi_prep_async_scan(shost); 2043 if (!data) { 2044 do_scsi_scan_host(shost); 2045 scsi_autopm_put_host(shost); 2046 return; 2047 } 2048 2049 /* register with the async subsystem so wait_for_device_probe() 2050 * will flush this work 2051 */ 2052 async_schedule(do_scan_async, data); 2053 2054 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 2055 } 2056 EXPORT_SYMBOL(scsi_scan_host); 2057 2058 void scsi_forget_host(struct Scsi_Host *shost) 2059 { 2060 struct scsi_device *sdev; 2061 unsigned long flags; 2062 2063 restart: 2064 spin_lock_irqsave(shost->host_lock, flags); 2065 list_for_each_entry(sdev, &shost->__devices, siblings) { 2066 if (sdev->sdev_state == SDEV_DEL) 2067 continue; 2068 spin_unlock_irqrestore(shost->host_lock, flags); 2069 __scsi_remove_device(sdev); 2070 goto restart; 2071 } 2072 spin_unlock_irqrestore(shost->host_lock, flags); 2073 } 2074 2075