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