1/* 2 * scsi_scan.c 3 * 4 * Copyright (C) 2000 Eric Youngdale, 5 * Copyright (C) 2002 Patrick Mansfield 6 * 7 * The general scanning/probing algorithm is as follows, exceptions are 8 * made to it depending on device specific flags, compilation options, and 9 * global variable (boot or module load time) settings. 10 * 11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a 12 * device attached, a scsi_device is allocated and setup for it. 13 * 14 * For every id of every channel on the given host: 15 * 16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no 17 * device or storage attached to LUN 0): 18 * 19 * If LUN 0 has a device attached, allocate and setup a 20 * scsi_device for it. 21 * 22 * If target is SCSI-3 or up, issue a REPORT LUN, and scan 23 * all of the LUNs returned by the REPORT LUN; else, 24 * sequentially scan LUNs up until some maximum is reached, 25 * or a LUN is seen that cannot have a device attached to it. 26 */ 27 28#include <linux/module.h> 29#include <linux/moduleparam.h> 30#include <linux/init.h> 31#include <linux/blkdev.h> 32#include <linux/delay.h> 33#include <linux/kthread.h> 34#include <linux/spinlock.h> 35#include <linux/async.h> 36#include <linux/slab.h> 37#include <asm/unaligned.h> 38 39#include <scsi/scsi.h> 40#include <scsi/scsi_cmnd.h> 41#include <scsi/scsi_device.h> 42#include <scsi/scsi_driver.h> 43#include <scsi/scsi_devinfo.h> 44#include <scsi/scsi_host.h> 45#include <scsi/scsi_transport.h> 46#include <scsi/scsi_eh.h> 47 48#include "scsi_priv.h" 49#include "scsi_logging.h" 50 51#define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 52 " SCSI scanning, some SCSI devices might not be configured\n" 53 54/* 55 * Default timeout 56 */ 57#define SCSI_TIMEOUT (2*HZ) 58 59/* 60 * Prefix values for the SCSI id's (stored in sysfs name field) 61 */ 62#define SCSI_UID_SER_NUM 'S' 63#define SCSI_UID_UNKNOWN 'Z' 64 65/* 66 * Return values of some of the scanning functions. 67 * 68 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 69 * includes allocation or general failures preventing IO from being sent. 70 * 71 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 72 * on the given LUN. 73 * 74 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 75 * given LUN. 76 */ 77#define SCSI_SCAN_NO_RESPONSE 0 78#define SCSI_SCAN_TARGET_PRESENT 1 79#define SCSI_SCAN_LUN_PRESENT 2 80 81static const char *scsi_null_device_strs = "nullnullnullnull"; 82 83#define MAX_SCSI_LUNS 512 84 85static u64 max_scsi_luns = MAX_SCSI_LUNS; 86 87module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR); 88MODULE_PARM_DESC(max_luns, 89 "last scsi LUN (should be between 1 and 2^64-1)"); 90 91#ifdef CONFIG_SCSI_SCAN_ASYNC 92#define SCSI_SCAN_TYPE_DEFAULT "async" 93#else 94#define SCSI_SCAN_TYPE_DEFAULT "sync" 95#endif 96 97char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT; 98 99module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO); 100MODULE_PARM_DESC(scan, "sync, async or none"); 101 102static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; 103 104module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR); 105MODULE_PARM_DESC(inq_timeout, 106 "Timeout (in seconds) waiting for devices to answer INQUIRY." 107 " Default is 20. Some devices may need more; most need less."); 108 109/* This lock protects only this list */ 110static DEFINE_SPINLOCK(async_scan_lock); 111static LIST_HEAD(scanning_hosts); 112 113struct async_scan_data { 114 struct list_head list; 115 struct Scsi_Host *shost; 116 struct completion prev_finished; 117}; 118 119/** 120 * scsi_complete_async_scans - Wait for asynchronous scans to complete 121 * 122 * When this function returns, any host which started scanning before 123 * this function was called will have finished its scan. Hosts which 124 * started scanning after this function was called may or may not have 125 * finished. 126 */ 127int scsi_complete_async_scans(void) 128{ 129 struct async_scan_data *data; 130 131 do { 132 if (list_empty(&scanning_hosts)) 133 return 0; 134 /* If we can't get memory immediately, that's OK. Just 135 * sleep a little. Even if we never get memory, the async 136 * scans will finish eventually. 137 */ 138 data = kmalloc(sizeof(*data), GFP_KERNEL); 139 if (!data) 140 msleep(1); 141 } while (!data); 142 143 data->shost = NULL; 144 init_completion(&data->prev_finished); 145 146 spin_lock(&async_scan_lock); 147 /* Check that there's still somebody else on the list */ 148 if (list_empty(&scanning_hosts)) 149 goto done; 150 list_add_tail(&data->list, &scanning_hosts); 151 spin_unlock(&async_scan_lock); 152 153 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 154 wait_for_completion(&data->prev_finished); 155 156 spin_lock(&async_scan_lock); 157 list_del(&data->list); 158 if (!list_empty(&scanning_hosts)) { 159 struct async_scan_data *next = list_entry(scanning_hosts.next, 160 struct async_scan_data, list); 161 complete(&next->prev_finished); 162 } 163 done: 164 spin_unlock(&async_scan_lock); 165 166 kfree(data); 167 return 0; 168} 169 170/** 171 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 172 * @sdev: scsi device to send command to 173 * @result: area to store the result of the MODE SENSE 174 * 175 * Description: 176 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 177 * Called for BLIST_KEY devices. 178 **/ 179static void scsi_unlock_floptical(struct scsi_device *sdev, 180 unsigned char *result) 181{ 182 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 183 184 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n"); 185 scsi_cmd[0] = MODE_SENSE; 186 scsi_cmd[1] = 0; 187 scsi_cmd[2] = 0x2e; 188 scsi_cmd[3] = 0; 189 scsi_cmd[4] = 0x2a; /* size */ 190 scsi_cmd[5] = 0; 191 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 192 SCSI_TIMEOUT, 3, NULL); 193} 194 195/** 196 * scsi_alloc_sdev - allocate and setup a scsi_Device 197 * @starget: which target to allocate a &scsi_device for 198 * @lun: which lun 199 * @hostdata: usually NULL and set by ->slave_alloc instead 200 * 201 * Description: 202 * Allocate, initialize for io, and return a pointer to a scsi_Device. 203 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 204 * adds scsi_Device to the appropriate list. 205 * 206 * Return value: 207 * scsi_Device pointer, or NULL on failure. 208 **/ 209static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 210 u64 lun, void *hostdata) 211{ 212 struct scsi_device *sdev; 213 int display_failure_msg = 1, ret; 214 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 215 extern void scsi_evt_thread(struct work_struct *work); 216 extern void scsi_requeue_run_queue(struct work_struct *work); 217 218 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 219 GFP_ATOMIC); 220 if (!sdev) 221 goto out; 222 223 sdev->vendor = scsi_null_device_strs; 224 sdev->model = scsi_null_device_strs; 225 sdev->rev = scsi_null_device_strs; 226 sdev->host = shost; 227 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 228 sdev->id = starget->id; 229 sdev->lun = lun; 230 sdev->channel = starget->channel; 231 sdev->sdev_state = SDEV_CREATED; 232 INIT_LIST_HEAD(&sdev->siblings); 233 INIT_LIST_HEAD(&sdev->same_target_siblings); 234 INIT_LIST_HEAD(&sdev->cmd_list); 235 INIT_LIST_HEAD(&sdev->starved_entry); 236 INIT_LIST_HEAD(&sdev->event_list); 237 spin_lock_init(&sdev->list_lock); 238 INIT_WORK(&sdev->event_work, scsi_evt_thread); 239 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 240 241 sdev->sdev_gendev.parent = get_device(&starget->dev); 242 sdev->sdev_target = starget; 243 244 /* usually NULL and set by ->slave_alloc instead */ 245 sdev->hostdata = hostdata; 246 247 /* if the device needs this changing, it may do so in the 248 * slave_configure function */ 249 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 250 251 /* 252 * Some low level driver could use device->type 253 */ 254 sdev->type = -1; 255 256 /* 257 * Assume that the device will have handshaking problems, 258 * and then fix this field later if it turns out it 259 * doesn't 260 */ 261 sdev->borken = 1; 262 263 if (shost_use_blk_mq(shost)) 264 sdev->request_queue = scsi_mq_alloc_queue(sdev); 265 else 266 sdev->request_queue = scsi_alloc_queue(sdev); 267 if (!sdev->request_queue) { 268 /* release fn is set up in scsi_sysfs_device_initialise, so 269 * have to free and put manually here */ 270 put_device(&starget->dev); 271 kfree(sdev); 272 goto out; 273 } 274 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); 275 sdev->request_queue->queuedata = sdev; 276 277 if (!shost_use_blk_mq(sdev->host) && 278 (shost->bqt || shost->hostt->use_blk_tags)) { 279 blk_queue_init_tags(sdev->request_queue, 280 sdev->host->cmd_per_lun, shost->bqt, 281 shost->hostt->tag_alloc_policy); 282 } 283 scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun); 284 285 scsi_sysfs_device_initialize(sdev); 286 287 if (shost->hostt->slave_alloc) { 288 ret = shost->hostt->slave_alloc(sdev); 289 if (ret) { 290 /* 291 * if LLDD reports slave not present, don't clutter 292 * console with alloc failure messages 293 */ 294 if (ret == -ENXIO) 295 display_failure_msg = 0; 296 goto out_device_destroy; 297 } 298 } 299 300 return sdev; 301 302out_device_destroy: 303 __scsi_remove_device(sdev); 304out: 305 if (display_failure_msg) 306 printk(ALLOC_FAILURE_MSG, __func__); 307 return NULL; 308} 309 310static void scsi_target_destroy(struct scsi_target *starget) 311{ 312 struct device *dev = &starget->dev; 313 struct Scsi_Host *shost = dev_to_shost(dev->parent); 314 unsigned long flags; 315 316 starget->state = STARGET_DEL; 317 transport_destroy_device(dev); 318 spin_lock_irqsave(shost->host_lock, flags); 319 if (shost->hostt->target_destroy) 320 shost->hostt->target_destroy(starget); 321 list_del_init(&starget->siblings); 322 spin_unlock_irqrestore(shost->host_lock, flags); 323 put_device(dev); 324} 325 326static void scsi_target_dev_release(struct device *dev) 327{ 328 struct device *parent = dev->parent; 329 struct scsi_target *starget = to_scsi_target(dev); 330 331 kfree(starget); 332 put_device(parent); 333} 334 335static struct device_type scsi_target_type = { 336 .name = "scsi_target", 337 .release = scsi_target_dev_release, 338}; 339 340int scsi_is_target_device(const struct device *dev) 341{ 342 return dev->type == &scsi_target_type; 343} 344EXPORT_SYMBOL(scsi_is_target_device); 345 346static struct scsi_target *__scsi_find_target(struct device *parent, 347 int channel, uint id) 348{ 349 struct scsi_target *starget, *found_starget = NULL; 350 struct Scsi_Host *shost = dev_to_shost(parent); 351 /* 352 * Search for an existing target for this sdev. 353 */ 354 list_for_each_entry(starget, &shost->__targets, siblings) { 355 if (starget->id == id && 356 starget->channel == channel) { 357 found_starget = starget; 358 break; 359 } 360 } 361 if (found_starget) 362 get_device(&found_starget->dev); 363 364 return found_starget; 365} 366 367/** 368 * scsi_target_reap_ref_release - remove target from visibility 369 * @kref: the reap_ref in the target being released 370 * 371 * Called on last put of reap_ref, which is the indication that no device 372 * under this target is visible anymore, so render the target invisible in 373 * sysfs. Note: we have to be in user context here because the target reaps 374 * should be done in places where the scsi device visibility is being removed. 375 */ 376static void scsi_target_reap_ref_release(struct kref *kref) 377{ 378 struct scsi_target *starget 379 = container_of(kref, struct scsi_target, reap_ref); 380 381 /* 382 * if we get here and the target is still in the CREATED state that 383 * means it was allocated but never made visible (because a scan 384 * turned up no LUNs), so don't call device_del() on it. 385 */ 386 if (starget->state != STARGET_CREATED) { 387 transport_remove_device(&starget->dev); 388 device_del(&starget->dev); 389 } 390 scsi_target_destroy(starget); 391} 392 393static void scsi_target_reap_ref_put(struct scsi_target *starget) 394{ 395 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 396} 397 398/** 399 * scsi_alloc_target - allocate a new or find an existing target 400 * @parent: parent of the target (need not be a scsi host) 401 * @channel: target channel number (zero if no channels) 402 * @id: target id number 403 * 404 * Return an existing target if one exists, provided it hasn't already 405 * gone into STARGET_DEL state, otherwise allocate a new target. 406 * 407 * The target is returned with an incremented reference, so the caller 408 * is responsible for both reaping and doing a last put 409 */ 410static struct scsi_target *scsi_alloc_target(struct device *parent, 411 int channel, uint id) 412{ 413 struct Scsi_Host *shost = dev_to_shost(parent); 414 struct device *dev = NULL; 415 unsigned long flags; 416 const int size = sizeof(struct scsi_target) 417 + shost->transportt->target_size; 418 struct scsi_target *starget; 419 struct scsi_target *found_target; 420 int error, ref_got; 421 422 starget = kzalloc(size, GFP_KERNEL); 423 if (!starget) { 424 printk(KERN_ERR "%s: allocation failure\n", __func__); 425 return NULL; 426 } 427 dev = &starget->dev; 428 device_initialize(dev); 429 kref_init(&starget->reap_ref); 430 dev->parent = get_device(parent); 431 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 432 dev->bus = &scsi_bus_type; 433 dev->type = &scsi_target_type; 434 starget->id = id; 435 starget->channel = channel; 436 starget->can_queue = 0; 437 INIT_LIST_HEAD(&starget->siblings); 438 INIT_LIST_HEAD(&starget->devices); 439 starget->state = STARGET_CREATED; 440 starget->scsi_level = SCSI_2; 441 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 442 retry: 443 spin_lock_irqsave(shost->host_lock, flags); 444 445 found_target = __scsi_find_target(parent, channel, id); 446 if (found_target) 447 goto found; 448 449 list_add_tail(&starget->siblings, &shost->__targets); 450 spin_unlock_irqrestore(shost->host_lock, flags); 451 /* allocate and add */ 452 transport_setup_device(dev); 453 if (shost->hostt->target_alloc) { 454 error = shost->hostt->target_alloc(starget); 455 456 if(error) { 457 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 458 /* don't want scsi_target_reap to do the final 459 * put because it will be under the host lock */ 460 scsi_target_destroy(starget); 461 return NULL; 462 } 463 } 464 get_device(dev); 465 466 return starget; 467 468 found: 469 /* 470 * release routine already fired if kref is zero, so if we can still 471 * take the reference, the target must be alive. If we can't, it must 472 * be dying and we need to wait for a new target 473 */ 474 ref_got = kref_get_unless_zero(&found_target->reap_ref); 475 476 spin_unlock_irqrestore(shost->host_lock, flags); 477 if (ref_got) { 478 put_device(dev); 479 return found_target; 480 } 481 /* 482 * Unfortunately, we found a dying target; need to wait until it's 483 * dead before we can get a new one. There is an anomaly here. We 484 * *should* call scsi_target_reap() to balance the kref_get() of the 485 * reap_ref above. However, since the target being released, it's 486 * already invisible and the reap_ref is irrelevant. If we call 487 * scsi_target_reap() we might spuriously do another device_del() on 488 * an already invisible target. 489 */ 490 put_device(&found_target->dev); 491 /* 492 * length of time is irrelevant here, we just want to yield the CPU 493 * for a tick to avoid busy waiting for the target to die. 494 */ 495 msleep(1); 496 goto retry; 497} 498 499/** 500 * scsi_target_reap - check to see if target is in use and destroy if not 501 * @starget: target to be checked 502 * 503 * This is used after removing a LUN or doing a last put of the target 504 * it checks atomically that nothing is using the target and removes 505 * it if so. 506 */ 507void scsi_target_reap(struct scsi_target *starget) 508{ 509 /* 510 * serious problem if this triggers: STARGET_DEL is only set in the if 511 * the reap_ref drops to zero, so we're trying to do another final put 512 * on an already released kref 513 */ 514 BUG_ON(starget->state == STARGET_DEL); 515 scsi_target_reap_ref_put(starget); 516} 517 518/** 519 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string 520 * @s: INQUIRY result string to sanitize 521 * @len: length of the string 522 * 523 * Description: 524 * The SCSI spec says that INQUIRY vendor, product, and revision 525 * strings must consist entirely of graphic ASCII characters, 526 * padded on the right with spaces. Since not all devices obey 527 * this rule, we will replace non-graphic or non-ASCII characters 528 * with spaces. Exception: a NUL character is interpreted as a 529 * string terminator, so all the following characters are set to 530 * spaces. 531 **/ 532static void sanitize_inquiry_string(unsigned char *s, int len) 533{ 534 int terminated = 0; 535 536 for (; len > 0; (--len, ++s)) { 537 if (*s == 0) 538 terminated = 1; 539 if (terminated || *s < 0x20 || *s > 0x7e) 540 *s = ' '; 541 } 542} 543 544/** 545 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 546 * @sdev: scsi_device to probe 547 * @inq_result: area to store the INQUIRY result 548 * @result_len: len of inq_result 549 * @bflags: store any bflags found here 550 * 551 * Description: 552 * Probe the lun associated with @req using a standard SCSI INQUIRY; 553 * 554 * If the INQUIRY is successful, zero is returned and the 555 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 556 * are copied to the scsi_device any flags value is stored in *@bflags. 557 **/ 558static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 559 int result_len, int *bflags) 560{ 561 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 562 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 563 int response_len = 0; 564 int pass, count, result; 565 struct scsi_sense_hdr sshdr; 566 567 *bflags = 0; 568 569 /* Perform up to 3 passes. The first pass uses a conservative 570 * transfer length of 36 unless sdev->inquiry_len specifies a 571 * different value. */ 572 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 573 try_inquiry_len = first_inquiry_len; 574 pass = 1; 575 576 next_pass: 577 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 578 "scsi scan: INQUIRY pass %d length %d\n", 579 pass, try_inquiry_len)); 580 581 /* Each pass gets up to three chances to ignore Unit Attention */ 582 for (count = 0; count < 3; ++count) { 583 int resid; 584 585 memset(scsi_cmd, 0, 6); 586 scsi_cmd[0] = INQUIRY; 587 scsi_cmd[4] = (unsigned char) try_inquiry_len; 588 589 memset(inq_result, 0, try_inquiry_len); 590 591 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 592 inq_result, try_inquiry_len, &sshdr, 593 HZ / 2 + HZ * scsi_inq_timeout, 3, 594 &resid); 595 596 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 597 "scsi scan: INQUIRY %s with code 0x%x\n", 598 result ? "failed" : "successful", result)); 599 600 if (result) { 601 /* 602 * not-ready to ready transition [asc/ascq=0x28/0x0] 603 * or power-on, reset [asc/ascq=0x29/0x0], continue. 604 * INQUIRY should not yield UNIT_ATTENTION 605 * but many buggy devices do so anyway. 606 */ 607 if ((driver_byte(result) & DRIVER_SENSE) && 608 scsi_sense_valid(&sshdr)) { 609 if ((sshdr.sense_key == UNIT_ATTENTION) && 610 ((sshdr.asc == 0x28) || 611 (sshdr.asc == 0x29)) && 612 (sshdr.ascq == 0)) 613 continue; 614 } 615 } else { 616 /* 617 * if nothing was transferred, we try 618 * again. It's a workaround for some USB 619 * devices. 620 */ 621 if (resid == try_inquiry_len) 622 continue; 623 } 624 break; 625 } 626 627 if (result == 0) { 628 sanitize_inquiry_string(&inq_result[8], 8); 629 sanitize_inquiry_string(&inq_result[16], 16); 630 sanitize_inquiry_string(&inq_result[32], 4); 631 632 response_len = inq_result[4] + 5; 633 if (response_len > 255) 634 response_len = first_inquiry_len; /* sanity */ 635 636 /* 637 * Get any flags for this device. 638 * 639 * XXX add a bflags to scsi_device, and replace the 640 * corresponding bit fields in scsi_device, so bflags 641 * need not be passed as an argument. 642 */ 643 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 644 &inq_result[16]); 645 646 /* When the first pass succeeds we gain information about 647 * what larger transfer lengths might work. */ 648 if (pass == 1) { 649 if (BLIST_INQUIRY_36 & *bflags) 650 next_inquiry_len = 36; 651 else if (BLIST_INQUIRY_58 & *bflags) 652 next_inquiry_len = 58; 653 else if (sdev->inquiry_len) 654 next_inquiry_len = sdev->inquiry_len; 655 else 656 next_inquiry_len = response_len; 657 658 /* If more data is available perform the second pass */ 659 if (next_inquiry_len > try_inquiry_len) { 660 try_inquiry_len = next_inquiry_len; 661 pass = 2; 662 goto next_pass; 663 } 664 } 665 666 } else if (pass == 2) { 667 sdev_printk(KERN_INFO, sdev, 668 "scsi scan: %d byte inquiry failed. " 669 "Consider BLIST_INQUIRY_36 for this device\n", 670 try_inquiry_len); 671 672 /* If this pass failed, the third pass goes back and transfers 673 * the same amount as we successfully got in the first pass. */ 674 try_inquiry_len = first_inquiry_len; 675 pass = 3; 676 goto next_pass; 677 } 678 679 /* If the last transfer attempt got an error, assume the 680 * peripheral doesn't exist or is dead. */ 681 if (result) 682 return -EIO; 683 684 /* Don't report any more data than the device says is valid */ 685 sdev->inquiry_len = min(try_inquiry_len, response_len); 686 687 /* 688 * XXX Abort if the response length is less than 36? If less than 689 * 32, the lookup of the device flags (above) could be invalid, 690 * and it would be possible to take an incorrect action - we do 691 * not want to hang because of a short INQUIRY. On the flip side, 692 * if the device is spun down or becoming ready (and so it gives a 693 * short INQUIRY), an abort here prevents any further use of the 694 * device, including spin up. 695 * 696 * On the whole, the best approach seems to be to assume the first 697 * 36 bytes are valid no matter what the device says. That's 698 * better than copying < 36 bytes to the inquiry-result buffer 699 * and displaying garbage for the Vendor, Product, or Revision 700 * strings. 701 */ 702 if (sdev->inquiry_len < 36) { 703 sdev_printk(KERN_INFO, sdev, 704 "scsi scan: INQUIRY result too short (%d)," 705 " using 36\n", sdev->inquiry_len); 706 sdev->inquiry_len = 36; 707 } 708 709 /* 710 * Related to the above issue: 711 * 712 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 713 * and if not ready, sent a START_STOP to start (maybe spin up) and 714 * then send the INQUIRY again, since the INQUIRY can change after 715 * a device is initialized. 716 * 717 * Ideally, start a device if explicitly asked to do so. This 718 * assumes that a device is spun up on power on, spun down on 719 * request, and then spun up on request. 720 */ 721 722 /* 723 * The scanning code needs to know the scsi_level, even if no 724 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 725 * non-zero LUNs can be scanned. 726 */ 727 sdev->scsi_level = inq_result[2] & 0x07; 728 if (sdev->scsi_level >= 2 || 729 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 730 sdev->scsi_level++; 731 sdev->sdev_target->scsi_level = sdev->scsi_level; 732 733 /* 734 * If SCSI-2 or lower, and if the transport requires it, 735 * store the LUN value in CDB[1]. 736 */ 737 sdev->lun_in_cdb = 0; 738 if (sdev->scsi_level <= SCSI_2 && 739 sdev->scsi_level != SCSI_UNKNOWN && 740 !sdev->host->no_scsi2_lun_in_cdb) 741 sdev->lun_in_cdb = 1; 742 743 return 0; 744} 745 746/** 747 * scsi_add_lun - allocate and fully initialze a scsi_device 748 * @sdev: holds information to be stored in the new scsi_device 749 * @inq_result: holds the result of a previous INQUIRY to the LUN 750 * @bflags: black/white list flag 751 * @async: 1 if this device is being scanned asynchronously 752 * 753 * Description: 754 * Initialize the scsi_device @sdev. Optionally set fields based 755 * on values in *@bflags. 756 * 757 * Return: 758 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 759 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 760 **/ 761static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 762 int *bflags, int async) 763{ 764 int ret; 765 766 /* 767 * XXX do not save the inquiry, since it can change underneath us, 768 * save just vendor/model/rev. 769 * 770 * Rather than save it and have an ioctl that retrieves the saved 771 * value, have an ioctl that executes the same INQUIRY code used 772 * in scsi_probe_lun, let user level programs doing INQUIRY 773 * scanning run at their own risk, or supply a user level program 774 * that can correctly scan. 775 */ 776 777 /* 778 * Copy at least 36 bytes of INQUIRY data, so that we don't 779 * dereference unallocated memory when accessing the Vendor, 780 * Product, and Revision strings. Badly behaved devices may set 781 * the INQUIRY Additional Length byte to a small value, indicating 782 * these strings are invalid, but often they contain plausible data 783 * nonetheless. It doesn't matter if the device sent < 36 bytes 784 * total, since scsi_probe_lun() initializes inq_result with 0s. 785 */ 786 sdev->inquiry = kmemdup(inq_result, 787 max_t(size_t, sdev->inquiry_len, 36), 788 GFP_ATOMIC); 789 if (sdev->inquiry == NULL) 790 return SCSI_SCAN_NO_RESPONSE; 791 792 sdev->vendor = (char *) (sdev->inquiry + 8); 793 sdev->model = (char *) (sdev->inquiry + 16); 794 sdev->rev = (char *) (sdev->inquiry + 32); 795 796 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 797 /* 798 * sata emulation layer device. This is a hack to work around 799 * the SATL power management specifications which state that 800 * when the SATL detects the device has gone into standby 801 * mode, it shall respond with NOT READY. 802 */ 803 sdev->allow_restart = 1; 804 } 805 806 if (*bflags & BLIST_ISROM) { 807 sdev->type = TYPE_ROM; 808 sdev->removable = 1; 809 } else { 810 sdev->type = (inq_result[0] & 0x1f); 811 sdev->removable = (inq_result[1] & 0x80) >> 7; 812 813 /* 814 * some devices may respond with wrong type for 815 * well-known logical units. Force well-known type 816 * to enumerate them correctly. 817 */ 818 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 819 sdev_printk(KERN_WARNING, sdev, 820 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 821 __func__, sdev->type, (unsigned int)sdev->lun); 822 sdev->type = TYPE_WLUN; 823 } 824 825 } 826 827 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 828 /* RBC and MMC devices can return SCSI-3 compliance and yet 829 * still not support REPORT LUNS, so make them act as 830 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 831 * specifically set */ 832 if ((*bflags & BLIST_REPORTLUN2) == 0) 833 *bflags |= BLIST_NOREPORTLUN; 834 } 835 836 /* 837 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 838 * spec says: The device server is capable of supporting the 839 * specified peripheral device type on this logical unit. However, 840 * the physical device is not currently connected to this logical 841 * unit. 842 * 843 * The above is vague, as it implies that we could treat 001 and 844 * 011 the same. Stay compatible with previous code, and create a 845 * scsi_device for a PQ of 1 846 * 847 * Don't set the device offline here; rather let the upper 848 * level drivers eval the PQ to decide whether they should 849 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 850 */ 851 852 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 853 sdev->lockable = sdev->removable; 854 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 855 856 if (sdev->scsi_level >= SCSI_3 || 857 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 858 sdev->ppr = 1; 859 if (inq_result[7] & 0x60) 860 sdev->wdtr = 1; 861 if (inq_result[7] & 0x10) 862 sdev->sdtr = 1; 863 864 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 865 "ANSI: %d%s\n", scsi_device_type(sdev->type), 866 sdev->vendor, sdev->model, sdev->rev, 867 sdev->inq_periph_qual, inq_result[2] & 0x07, 868 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 869 870 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 871 !(*bflags & BLIST_NOTQ)) { 872 sdev->tagged_supported = 1; 873 sdev->simple_tags = 1; 874 } 875 876 /* 877 * Some devices (Texel CD ROM drives) have handshaking problems 878 * when used with the Seagate controllers. borken is initialized 879 * to 1, and then set it to 0 here. 880 */ 881 if ((*bflags & BLIST_BORKEN) == 0) 882 sdev->borken = 0; 883 884 if (*bflags & BLIST_NO_ULD_ATTACH) 885 sdev->no_uld_attach = 1; 886 887 /* 888 * Apparently some really broken devices (contrary to the SCSI 889 * standards) need to be selected without asserting ATN 890 */ 891 if (*bflags & BLIST_SELECT_NO_ATN) 892 sdev->select_no_atn = 1; 893 894 /* 895 * Maximum 512 sector transfer length 896 * broken RA4x00 Compaq Disk Array 897 */ 898 if (*bflags & BLIST_MAX_512) 899 blk_queue_max_hw_sectors(sdev->request_queue, 512); 900 /* 901 * Max 1024 sector transfer length for targets that report incorrect 902 * max/optimal lengths and relied on the old block layer safe default 903 */ 904 else if (*bflags & BLIST_MAX_1024) 905 blk_queue_max_hw_sectors(sdev->request_queue, 1024); 906 907 /* 908 * Some devices may not want to have a start command automatically 909 * issued when a device is added. 910 */ 911 if (*bflags & BLIST_NOSTARTONADD) 912 sdev->no_start_on_add = 1; 913 914 if (*bflags & BLIST_SINGLELUN) 915 scsi_target(sdev)->single_lun = 1; 916 917 sdev->use_10_for_rw = 1; 918 919 if (*bflags & BLIST_MS_SKIP_PAGE_08) 920 sdev->skip_ms_page_8 = 1; 921 922 if (*bflags & BLIST_MS_SKIP_PAGE_3F) 923 sdev->skip_ms_page_3f = 1; 924 925 if (*bflags & BLIST_USE_10_BYTE_MS) 926 sdev->use_10_for_ms = 1; 927 928 /* some devices don't like REPORT SUPPORTED OPERATION CODES 929 * and will simply timeout causing sd_mod init to take a very 930 * very long time */ 931 if (*bflags & BLIST_NO_RSOC) 932 sdev->no_report_opcodes = 1; 933 934 /* set the device running here so that slave configure 935 * may do I/O */ 936 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 937 if (ret) { 938 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 939 940 if (ret) { 941 sdev_printk(KERN_ERR, sdev, 942 "in wrong state %s to complete scan\n", 943 scsi_device_state_name(sdev->sdev_state)); 944 return SCSI_SCAN_NO_RESPONSE; 945 } 946 } 947 948 if (*bflags & BLIST_MS_192_BYTES_FOR_3F) 949 sdev->use_192_bytes_for_3f = 1; 950 951 if (*bflags & BLIST_NOT_LOCKABLE) 952 sdev->lockable = 0; 953 954 if (*bflags & BLIST_RETRY_HWERROR) 955 sdev->retry_hwerror = 1; 956 957 if (*bflags & BLIST_NO_DIF) 958 sdev->no_dif = 1; 959 960 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 961 962 if (*bflags & BLIST_TRY_VPD_PAGES) 963 sdev->try_vpd_pages = 1; 964 else if (*bflags & BLIST_SKIP_VPD_PAGES) 965 sdev->skip_vpd_pages = 1; 966 967 transport_configure_device(&sdev->sdev_gendev); 968 969 if (sdev->host->hostt->slave_configure) { 970 ret = sdev->host->hostt->slave_configure(sdev); 971 if (ret) { 972 /* 973 * if LLDD reports slave not present, don't clutter 974 * console with alloc failure messages 975 */ 976 if (ret != -ENXIO) { 977 sdev_printk(KERN_ERR, sdev, 978 "failed to configure device\n"); 979 } 980 return SCSI_SCAN_NO_RESPONSE; 981 } 982 } 983 984 if (sdev->scsi_level >= SCSI_3) 985 scsi_attach_vpd(sdev); 986 987 sdev->max_queue_depth = sdev->queue_depth; 988 989 /* 990 * Ok, the device is now all set up, we can 991 * register it and tell the rest of the kernel 992 * about it. 993 */ 994 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 995 return SCSI_SCAN_NO_RESPONSE; 996 997 return SCSI_SCAN_LUN_PRESENT; 998} 999 1000#ifdef CONFIG_SCSI_LOGGING 1001/** 1002 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1003 * @buf: Output buffer with at least end-first+1 bytes of space 1004 * @inq: Inquiry buffer (input) 1005 * @first: Offset of string into inq 1006 * @end: Index after last character in inq 1007 */ 1008static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1009 unsigned first, unsigned end) 1010{ 1011 unsigned term = 0, idx; 1012 1013 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1014 if (inq[idx+first] > ' ') { 1015 buf[idx] = inq[idx+first]; 1016 term = idx+1; 1017 } else { 1018 buf[idx] = ' '; 1019 } 1020 } 1021 buf[term] = 0; 1022 return buf; 1023} 1024#endif 1025 1026/** 1027 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1028 * @starget: pointer to target device structure 1029 * @lun: LUN of target device 1030 * @bflagsp: store bflags here if not NULL 1031 * @sdevp: probe the LUN corresponding to this scsi_device 1032 * @rescan: if nonzero skip some code only needed on first scan 1033 * @hostdata: passed to scsi_alloc_sdev() 1034 * 1035 * Description: 1036 * Call scsi_probe_lun, if a LUN with an attached device is found, 1037 * allocate and set it up by calling scsi_add_lun. 1038 * 1039 * Return: 1040 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1041 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1042 * attached at the LUN 1043 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1044 **/ 1045static int scsi_probe_and_add_lun(struct scsi_target *starget, 1046 u64 lun, int *bflagsp, 1047 struct scsi_device **sdevp, int rescan, 1048 void *hostdata) 1049{ 1050 struct scsi_device *sdev; 1051 unsigned char *result; 1052 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1053 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1054 1055 /* 1056 * The rescan flag is used as an optimization, the first scan of a 1057 * host adapter calls into here with rescan == 0. 1058 */ 1059 sdev = scsi_device_lookup_by_target(starget, lun); 1060 if (sdev) { 1061 if (rescan || !scsi_device_created(sdev)) { 1062 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1063 "scsi scan: device exists on %s\n", 1064 dev_name(&sdev->sdev_gendev))); 1065 if (sdevp) 1066 *sdevp = sdev; 1067 else 1068 scsi_device_put(sdev); 1069 1070 if (bflagsp) 1071 *bflagsp = scsi_get_device_flags(sdev, 1072 sdev->vendor, 1073 sdev->model); 1074 return SCSI_SCAN_LUN_PRESENT; 1075 } 1076 scsi_device_put(sdev); 1077 } else 1078 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1079 if (!sdev) 1080 goto out; 1081 1082 result = kmalloc(result_len, GFP_ATOMIC | 1083 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1084 if (!result) 1085 goto out_free_sdev; 1086 1087 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1088 goto out_free_result; 1089 1090 if (bflagsp) 1091 *bflagsp = bflags; 1092 /* 1093 * result contains valid SCSI INQUIRY data. 1094 */ 1095 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) { 1096 /* 1097 * For a Peripheral qualifier 3 (011b), the SCSI 1098 * spec says: The device server is not capable of 1099 * supporting a physical device on this logical 1100 * unit. 1101 * 1102 * For disks, this implies that there is no 1103 * logical disk configured at sdev->lun, but there 1104 * is a target id responding. 1105 */ 1106 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1107 " peripheral qualifier of 3, device not" 1108 " added\n")) 1109 if (lun == 0) { 1110 SCSI_LOG_SCAN_BUS(1, { 1111 unsigned char vend[9]; 1112 unsigned char mod[17]; 1113 1114 sdev_printk(KERN_INFO, sdev, 1115 "scsi scan: consider passing scsi_mod." 1116 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1117 scsi_inq_str(vend, result, 8, 16), 1118 scsi_inq_str(mod, result, 16, 32)); 1119 }); 1120 1121 } 1122 1123 res = SCSI_SCAN_TARGET_PRESENT; 1124 goto out_free_result; 1125 } 1126 1127 /* 1128 * Some targets may set slight variations of PQ and PDT to signal 1129 * that no LUN is present, so don't add sdev in these cases. 1130 * Two specific examples are: 1131 * 1) NetApp targets: return PQ=1, PDT=0x1f 1132 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1133 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1134 * 1135 * References: 1136 * 1) SCSI SPC-3, pp. 145-146 1137 * PQ=1: "A peripheral device having the specified peripheral 1138 * device type is not connected to this logical unit. However, the 1139 * device server is capable of supporting the specified peripheral 1140 * device type on this logical unit." 1141 * PDT=0x1f: "Unknown or no device type" 1142 * 2) USB UFI 1.0, p. 20 1143 * PDT=00h Direct-access device (floppy) 1144 * PDT=1Fh none (no FDD connected to the requested logical unit) 1145 */ 1146 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1147 (result[0] & 0x1f) == 0x1f && 1148 !scsi_is_wlun(lun)) { 1149 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1150 "scsi scan: peripheral device type" 1151 " of 31, no device added\n")); 1152 res = SCSI_SCAN_TARGET_PRESENT; 1153 goto out_free_result; 1154 } 1155 1156 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1157 if (res == SCSI_SCAN_LUN_PRESENT) { 1158 if (bflags & BLIST_KEY) { 1159 sdev->lockable = 0; 1160 scsi_unlock_floptical(sdev, result); 1161 } 1162 } 1163 1164 out_free_result: 1165 kfree(result); 1166 out_free_sdev: 1167 if (res == SCSI_SCAN_LUN_PRESENT) { 1168 if (sdevp) { 1169 if (scsi_device_get(sdev) == 0) { 1170 *sdevp = sdev; 1171 } else { 1172 __scsi_remove_device(sdev); 1173 res = SCSI_SCAN_NO_RESPONSE; 1174 } 1175 } 1176 } else 1177 __scsi_remove_device(sdev); 1178 out: 1179 return res; 1180} 1181 1182/** 1183 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1184 * @starget: pointer to target structure to scan 1185 * @bflags: black/white list flag for LUN 0 1186 * @scsi_level: Which version of the standard does this device adhere to 1187 * @rescan: passed to scsi_probe_add_lun() 1188 * 1189 * Description: 1190 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1191 * scanned) to some maximum lun until a LUN is found with no device 1192 * attached. Use the bflags to figure out any oddities. 1193 * 1194 * Modifies sdevscan->lun. 1195 **/ 1196static void scsi_sequential_lun_scan(struct scsi_target *starget, 1197 int bflags, int scsi_level, int rescan) 1198{ 1199 uint max_dev_lun; 1200 u64 sparse_lun, lun; 1201 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1202 1203 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1204 "scsi scan: Sequential scan\n")); 1205 1206 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1207 /* 1208 * If this device is known to support sparse multiple units, 1209 * override the other settings, and scan all of them. Normally, 1210 * SCSI-3 devices should be scanned via the REPORT LUNS. 1211 */ 1212 if (bflags & BLIST_SPARSELUN) { 1213 max_dev_lun = shost->max_lun; 1214 sparse_lun = 1; 1215 } else 1216 sparse_lun = 0; 1217 1218 /* 1219 * If less than SCSI_1_CCS, and no special lun scanning, stop 1220 * scanning; this matches 2.4 behaviour, but could just be a bug 1221 * (to continue scanning a SCSI_1_CCS device). 1222 * 1223 * This test is broken. We might not have any device on lun0 for 1224 * a sparselun device, and if that's the case then how would we 1225 * know the real scsi_level, eh? It might make sense to just not 1226 * scan any SCSI_1 device for non-0 luns, but that check would best 1227 * go into scsi_alloc_sdev() and just have it return null when asked 1228 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1229 * 1230 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1231 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1232 == 0)) 1233 return; 1234 */ 1235 /* 1236 * If this device is known to support multiple units, override 1237 * the other settings, and scan all of them. 1238 */ 1239 if (bflags & BLIST_FORCELUN) 1240 max_dev_lun = shost->max_lun; 1241 /* 1242 * REGAL CDC-4X: avoid hang after LUN 4 1243 */ 1244 if (bflags & BLIST_MAX5LUN) 1245 max_dev_lun = min(5U, max_dev_lun); 1246 /* 1247 * Do not scan SCSI-2 or lower device past LUN 7, unless 1248 * BLIST_LARGELUN. 1249 */ 1250 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1251 max_dev_lun = min(8U, max_dev_lun); 1252 1253 /* 1254 * Stop scanning at 255 unless BLIST_SCSI3LUN 1255 */ 1256 if (!(bflags & BLIST_SCSI3LUN)) 1257 max_dev_lun = min(256U, max_dev_lun); 1258 1259 /* 1260 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1261 * until we reach the max, or no LUN is found and we are not 1262 * sparse_lun. 1263 */ 1264 for (lun = 1; lun < max_dev_lun; ++lun) 1265 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1266 NULL) != SCSI_SCAN_LUN_PRESENT) && 1267 !sparse_lun) 1268 return; 1269} 1270 1271/** 1272 * scsilun_to_int - convert a scsi_lun to an int 1273 * @scsilun: struct scsi_lun to be converted. 1274 * 1275 * Description: 1276 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered 1277 * integer, and return the result. The caller must check for 1278 * truncation before using this function. 1279 * 1280 * Notes: 1281 * For a description of the LUN format, post SCSI-3 see the SCSI 1282 * Architecture Model, for SCSI-3 see the SCSI Controller Commands. 1283 * 1284 * Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function 1285 * returns the integer: 0x0b03d204 1286 * 1287 * This encoding will return a standard integer LUN for LUNs smaller 1288 * than 256, which typically use a single level LUN structure with 1289 * addressing method 0. 1290 **/ 1291u64 scsilun_to_int(struct scsi_lun *scsilun) 1292{ 1293 int i; 1294 u64 lun; 1295 1296 lun = 0; 1297 for (i = 0; i < sizeof(lun); i += 2) 1298 lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) | 1299 ((u64)scsilun->scsi_lun[i + 1] << (i * 8))); 1300 return lun; 1301} 1302EXPORT_SYMBOL(scsilun_to_int); 1303 1304/** 1305 * int_to_scsilun - reverts an int into a scsi_lun 1306 * @lun: integer to be reverted 1307 * @scsilun: struct scsi_lun to be set. 1308 * 1309 * Description: 1310 * Reverts the functionality of the scsilun_to_int, which packed 1311 * an 8-byte lun value into an int. This routine unpacks the int 1312 * back into the lun value. 1313 * 1314 * Notes: 1315 * Given an integer : 0x0b03d204, this function returns a 1316 * struct scsi_lun of: d2 04 0b 03 00 00 00 00 1317 * 1318 **/ 1319void int_to_scsilun(u64 lun, struct scsi_lun *scsilun) 1320{ 1321 int i; 1322 1323 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun)); 1324 1325 for (i = 0; i < sizeof(lun); i += 2) { 1326 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF; 1327 scsilun->scsi_lun[i+1] = lun & 0xFF; 1328 lun = lun >> 16; 1329 } 1330} 1331EXPORT_SYMBOL(int_to_scsilun); 1332 1333/** 1334 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1335 * @starget: which target 1336 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1337 * @rescan: nonzero if we can skip code only needed on first scan 1338 * 1339 * Description: 1340 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1341 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1342 * 1343 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1344 * LUNs even if it's older than SCSI-3. 1345 * If BLIST_NOREPORTLUN is set, return 1 always. 1346 * If BLIST_NOLUN is set, return 0 always. 1347 * If starget->no_report_luns is set, return 1 always. 1348 * 1349 * Return: 1350 * 0: scan completed (or no memory, so further scanning is futile) 1351 * 1: could not scan with REPORT LUN 1352 **/ 1353static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, 1354 int rescan) 1355{ 1356 char devname[64]; 1357 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1358 unsigned int length; 1359 u64 lun; 1360 unsigned int num_luns; 1361 unsigned int retries; 1362 int result; 1363 struct scsi_lun *lunp, *lun_data; 1364 struct scsi_sense_hdr sshdr; 1365 struct scsi_device *sdev; 1366 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1367 int ret = 0; 1368 1369 /* 1370 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1371 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1372 * support more than 8 LUNs. 1373 * Don't attempt if the target doesn't support REPORT LUNS. 1374 */ 1375 if (bflags & BLIST_NOREPORTLUN) 1376 return 1; 1377 if (starget->scsi_level < SCSI_2 && 1378 starget->scsi_level != SCSI_UNKNOWN) 1379 return 1; 1380 if (starget->scsi_level < SCSI_3 && 1381 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1382 return 1; 1383 if (bflags & BLIST_NOLUN) 1384 return 0; 1385 if (starget->no_report_luns) 1386 return 1; 1387 1388 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1389 sdev = scsi_alloc_sdev(starget, 0, NULL); 1390 if (!sdev) 1391 return 0; 1392 if (scsi_device_get(sdev)) { 1393 __scsi_remove_device(sdev); 1394 return 0; 1395 } 1396 } 1397 1398 sprintf(devname, "host %d channel %d id %d", 1399 shost->host_no, sdev->channel, sdev->id); 1400 1401 /* 1402 * Allocate enough to hold the header (the same size as one scsi_lun) 1403 * plus the number of luns we are requesting. 511 was the default 1404 * value of the now removed max_report_luns parameter. 1405 */ 1406 length = (511 + 1) * sizeof(struct scsi_lun); 1407retry: 1408 lun_data = kmalloc(length, GFP_KERNEL | 1409 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1410 if (!lun_data) { 1411 printk(ALLOC_FAILURE_MSG, __func__); 1412 goto out; 1413 } 1414 1415 scsi_cmd[0] = REPORT_LUNS; 1416 1417 /* 1418 * bytes 1 - 5: reserved, set to zero. 1419 */ 1420 memset(&scsi_cmd[1], 0, 5); 1421 1422 /* 1423 * bytes 6 - 9: length of the command. 1424 */ 1425 put_unaligned_be32(length, &scsi_cmd[6]); 1426 1427 scsi_cmd[10] = 0; /* reserved */ 1428 scsi_cmd[11] = 0; /* control */ 1429 1430 /* 1431 * We can get a UNIT ATTENTION, for example a power on/reset, so 1432 * retry a few times (like sd.c does for TEST UNIT READY). 1433 * Experience shows some combinations of adapter/devices get at 1434 * least two power on/resets. 1435 * 1436 * Illegal requests (for devices that do not support REPORT LUNS) 1437 * should come through as a check condition, and will not generate 1438 * a retry. 1439 */ 1440 for (retries = 0; retries < 3; retries++) { 1441 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1442 "scsi scan: Sending REPORT LUNS to (try %d)\n", 1443 retries)); 1444 1445 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1446 lun_data, length, &sshdr, 1447 SCSI_TIMEOUT + 4 * HZ, 3, NULL); 1448 1449 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1450 "scsi scan: REPORT LUNS" 1451 " %s (try %d) result 0x%x\n", 1452 result ? "failed" : "successful", 1453 retries, result)); 1454 if (result == 0) 1455 break; 1456 else if (scsi_sense_valid(&sshdr)) { 1457 if (sshdr.sense_key != UNIT_ATTENTION) 1458 break; 1459 } 1460 } 1461 1462 if (result) { 1463 /* 1464 * The device probably does not support a REPORT LUN command 1465 */ 1466 ret = 1; 1467 goto out_err; 1468 } 1469 1470 /* 1471 * Get the length from the first four bytes of lun_data. 1472 */ 1473 if (get_unaligned_be32(lun_data->scsi_lun) + 1474 sizeof(struct scsi_lun) > length) { 1475 length = get_unaligned_be32(lun_data->scsi_lun) + 1476 sizeof(struct scsi_lun); 1477 kfree(lun_data); 1478 goto retry; 1479 } 1480 length = get_unaligned_be32(lun_data->scsi_lun); 1481 1482 num_luns = (length / sizeof(struct scsi_lun)); 1483 1484 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1485 "scsi scan: REPORT LUN scan\n")); 1486 1487 /* 1488 * Scan the luns in lun_data. The entry at offset 0 is really 1489 * the header, so start at 1 and go up to and including num_luns. 1490 */ 1491 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1492 lun = scsilun_to_int(lunp); 1493 1494 if (lun > sdev->host->max_lun) { 1495 sdev_printk(KERN_WARNING, sdev, 1496 "lun%llu has a LUN larger than" 1497 " allowed by the host adapter\n", lun); 1498 } else { 1499 int res; 1500 1501 res = scsi_probe_and_add_lun(starget, 1502 lun, NULL, NULL, rescan, NULL); 1503 if (res == SCSI_SCAN_NO_RESPONSE) { 1504 /* 1505 * Got some results, but now none, abort. 1506 */ 1507 sdev_printk(KERN_ERR, sdev, 1508 "Unexpected response" 1509 " from lun %llu while scanning, scan" 1510 " aborted\n", (unsigned long long)lun); 1511 break; 1512 } 1513 } 1514 } 1515 1516 out_err: 1517 kfree(lun_data); 1518 out: 1519 scsi_device_put(sdev); 1520 if (scsi_device_created(sdev)) 1521 /* 1522 * the sdev we used didn't appear in the report luns scan 1523 */ 1524 __scsi_remove_device(sdev); 1525 return ret; 1526} 1527 1528struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1529 uint id, u64 lun, void *hostdata) 1530{ 1531 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1532 struct device *parent = &shost->shost_gendev; 1533 struct scsi_target *starget; 1534 1535 if (strncmp(scsi_scan_type, "none", 4) == 0) 1536 return ERR_PTR(-ENODEV); 1537 1538 starget = scsi_alloc_target(parent, channel, id); 1539 if (!starget) 1540 return ERR_PTR(-ENOMEM); 1541 scsi_autopm_get_target(starget); 1542 1543 mutex_lock(&shost->scan_mutex); 1544 if (!shost->async_scan) 1545 scsi_complete_async_scans(); 1546 1547 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1548 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1549 scsi_autopm_put_host(shost); 1550 } 1551 mutex_unlock(&shost->scan_mutex); 1552 scsi_autopm_put_target(starget); 1553 /* 1554 * paired with scsi_alloc_target(). Target will be destroyed unless 1555 * scsi_probe_and_add_lun made an underlying device visible 1556 */ 1557 scsi_target_reap(starget); 1558 put_device(&starget->dev); 1559 1560 return sdev; 1561} 1562EXPORT_SYMBOL(__scsi_add_device); 1563 1564int scsi_add_device(struct Scsi_Host *host, uint channel, 1565 uint target, u64 lun) 1566{ 1567 struct scsi_device *sdev = 1568 __scsi_add_device(host, channel, target, lun, NULL); 1569 if (IS_ERR(sdev)) 1570 return PTR_ERR(sdev); 1571 1572 scsi_device_put(sdev); 1573 return 0; 1574} 1575EXPORT_SYMBOL(scsi_add_device); 1576 1577void scsi_rescan_device(struct device *dev) 1578{ 1579 device_lock(dev); 1580 if (dev->driver && try_module_get(dev->driver->owner)) { 1581 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1582 1583 if (drv->rescan) 1584 drv->rescan(dev); 1585 module_put(dev->driver->owner); 1586 } 1587 device_unlock(dev); 1588} 1589EXPORT_SYMBOL(scsi_rescan_device); 1590 1591static void __scsi_scan_target(struct device *parent, unsigned int channel, 1592 unsigned int id, u64 lun, int rescan) 1593{ 1594 struct Scsi_Host *shost = dev_to_shost(parent); 1595 int bflags = 0; 1596 int res; 1597 struct scsi_target *starget; 1598 1599 if (shost->this_id == id) 1600 /* 1601 * Don't scan the host adapter 1602 */ 1603 return; 1604 1605 starget = scsi_alloc_target(parent, channel, id); 1606 if (!starget) 1607 return; 1608 scsi_autopm_get_target(starget); 1609 1610 if (lun != SCAN_WILD_CARD) { 1611 /* 1612 * Scan for a specific host/chan/id/lun. 1613 */ 1614 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1615 goto out_reap; 1616 } 1617 1618 /* 1619 * Scan LUN 0, if there is some response, scan further. Ideally, we 1620 * would not configure LUN 0 until all LUNs are scanned. 1621 */ 1622 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1623 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1624 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1625 /* 1626 * The REPORT LUN did not scan the target, 1627 * do a sequential scan. 1628 */ 1629 scsi_sequential_lun_scan(starget, bflags, 1630 starget->scsi_level, rescan); 1631 } 1632 1633 out_reap: 1634 scsi_autopm_put_target(starget); 1635 /* 1636 * paired with scsi_alloc_target(): determine if the target has 1637 * any children at all and if not, nuke it 1638 */ 1639 scsi_target_reap(starget); 1640 1641 put_device(&starget->dev); 1642} 1643 1644/** 1645 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1646 * @parent: host to scan 1647 * @channel: channel to scan 1648 * @id: target id to scan 1649 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1650 * @rescan: passed to LUN scanning routines 1651 * 1652 * Description: 1653 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1654 * and possibly all LUNs on the target id. 1655 * 1656 * First try a REPORT LUN scan, if that does not scan the target, do a 1657 * sequential scan of LUNs on the target id. 1658 **/ 1659void scsi_scan_target(struct device *parent, unsigned int channel, 1660 unsigned int id, u64 lun, int rescan) 1661{ 1662 struct Scsi_Host *shost = dev_to_shost(parent); 1663 1664 if (strncmp(scsi_scan_type, "none", 4) == 0) 1665 return; 1666 1667 mutex_lock(&shost->scan_mutex); 1668 if (!shost->async_scan) 1669 scsi_complete_async_scans(); 1670 1671 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1672 __scsi_scan_target(parent, channel, id, lun, rescan); 1673 scsi_autopm_put_host(shost); 1674 } 1675 mutex_unlock(&shost->scan_mutex); 1676} 1677EXPORT_SYMBOL(scsi_scan_target); 1678 1679static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1680 unsigned int id, u64 lun, int rescan) 1681{ 1682 uint order_id; 1683 1684 if (id == SCAN_WILD_CARD) 1685 for (id = 0; id < shost->max_id; ++id) { 1686 /* 1687 * XXX adapter drivers when possible (FCP, iSCSI) 1688 * could modify max_id to match the current max, 1689 * not the absolute max. 1690 * 1691 * XXX add a shost id iterator, so for example, 1692 * the FC ID can be the same as a target id 1693 * without a huge overhead of sparse id's. 1694 */ 1695 if (shost->reverse_ordering) 1696 /* 1697 * Scan from high to low id. 1698 */ 1699 order_id = shost->max_id - id - 1; 1700 else 1701 order_id = id; 1702 __scsi_scan_target(&shost->shost_gendev, channel, 1703 order_id, lun, rescan); 1704 } 1705 else 1706 __scsi_scan_target(&shost->shost_gendev, channel, 1707 id, lun, rescan); 1708} 1709 1710int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1711 unsigned int id, u64 lun, int rescan) 1712{ 1713 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1714 "%s: <%u:%u:%llu>\n", 1715 __func__, channel, id, lun)); 1716 1717 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1718 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1719 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1720 return -EINVAL; 1721 1722 mutex_lock(&shost->scan_mutex); 1723 if (!shost->async_scan) 1724 scsi_complete_async_scans(); 1725 1726 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1727 if (channel == SCAN_WILD_CARD) 1728 for (channel = 0; channel <= shost->max_channel; 1729 channel++) 1730 scsi_scan_channel(shost, channel, id, lun, 1731 rescan); 1732 else 1733 scsi_scan_channel(shost, channel, id, lun, rescan); 1734 scsi_autopm_put_host(shost); 1735 } 1736 mutex_unlock(&shost->scan_mutex); 1737 1738 return 0; 1739} 1740 1741static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1742{ 1743 struct scsi_device *sdev; 1744 shost_for_each_device(sdev, shost) { 1745 /* target removed before the device could be added */ 1746 if (sdev->sdev_state == SDEV_DEL) 1747 continue; 1748 /* If device is already visible, skip adding it to sysfs */ 1749 if (sdev->is_visible) 1750 continue; 1751 if (!scsi_host_scan_allowed(shost) || 1752 scsi_sysfs_add_sdev(sdev) != 0) 1753 __scsi_remove_device(sdev); 1754 } 1755} 1756 1757/** 1758 * scsi_prep_async_scan - prepare for an async scan 1759 * @shost: the host which will be scanned 1760 * Returns: a cookie to be passed to scsi_finish_async_scan() 1761 * 1762 * Tells the midlayer this host is going to do an asynchronous scan. 1763 * It reserves the host's position in the scanning list and ensures 1764 * that other asynchronous scans started after this one won't affect the 1765 * ordering of the discovered devices. 1766 */ 1767static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1768{ 1769 struct async_scan_data *data; 1770 unsigned long flags; 1771 1772 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1773 return NULL; 1774 1775 if (shost->async_scan) { 1776 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1777 dump_stack(); 1778 return NULL; 1779 } 1780 1781 data = kmalloc(sizeof(*data), GFP_KERNEL); 1782 if (!data) 1783 goto err; 1784 data->shost = scsi_host_get(shost); 1785 if (!data->shost) 1786 goto err; 1787 init_completion(&data->prev_finished); 1788 1789 mutex_lock(&shost->scan_mutex); 1790 spin_lock_irqsave(shost->host_lock, flags); 1791 shost->async_scan = 1; 1792 spin_unlock_irqrestore(shost->host_lock, flags); 1793 mutex_unlock(&shost->scan_mutex); 1794 1795 spin_lock(&async_scan_lock); 1796 if (list_empty(&scanning_hosts)) 1797 complete(&data->prev_finished); 1798 list_add_tail(&data->list, &scanning_hosts); 1799 spin_unlock(&async_scan_lock); 1800 1801 return data; 1802 1803 err: 1804 kfree(data); 1805 return NULL; 1806} 1807 1808/** 1809 * scsi_finish_async_scan - asynchronous scan has finished 1810 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1811 * 1812 * All the devices currently attached to this host have been found. 1813 * This function announces all the devices it has found to the rest 1814 * of the system. 1815 */ 1816static void scsi_finish_async_scan(struct async_scan_data *data) 1817{ 1818 struct Scsi_Host *shost; 1819 unsigned long flags; 1820 1821 if (!data) 1822 return; 1823 1824 shost = data->shost; 1825 1826 mutex_lock(&shost->scan_mutex); 1827 1828 if (!shost->async_scan) { 1829 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1830 dump_stack(); 1831 mutex_unlock(&shost->scan_mutex); 1832 return; 1833 } 1834 1835 wait_for_completion(&data->prev_finished); 1836 1837 scsi_sysfs_add_devices(shost); 1838 1839 spin_lock_irqsave(shost->host_lock, flags); 1840 shost->async_scan = 0; 1841 spin_unlock_irqrestore(shost->host_lock, flags); 1842 1843 mutex_unlock(&shost->scan_mutex); 1844 1845 spin_lock(&async_scan_lock); 1846 list_del(&data->list); 1847 if (!list_empty(&scanning_hosts)) { 1848 struct async_scan_data *next = list_entry(scanning_hosts.next, 1849 struct async_scan_data, list); 1850 complete(&next->prev_finished); 1851 } 1852 spin_unlock(&async_scan_lock); 1853 1854 scsi_autopm_put_host(shost); 1855 scsi_host_put(shost); 1856 kfree(data); 1857} 1858 1859static void do_scsi_scan_host(struct Scsi_Host *shost) 1860{ 1861 if (shost->hostt->scan_finished) { 1862 unsigned long start = jiffies; 1863 if (shost->hostt->scan_start) 1864 shost->hostt->scan_start(shost); 1865 1866 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1867 msleep(10); 1868 } else { 1869 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1870 SCAN_WILD_CARD, 0); 1871 } 1872} 1873 1874static void do_scan_async(void *_data, async_cookie_t c) 1875{ 1876 struct async_scan_data *data = _data; 1877 struct Scsi_Host *shost = data->shost; 1878 1879 do_scsi_scan_host(shost); 1880 scsi_finish_async_scan(data); 1881} 1882 1883/** 1884 * scsi_scan_host - scan the given adapter 1885 * @shost: adapter to scan 1886 **/ 1887void scsi_scan_host(struct Scsi_Host *shost) 1888{ 1889 struct async_scan_data *data; 1890 1891 if (strncmp(scsi_scan_type, "none", 4) == 0) 1892 return; 1893 if (scsi_autopm_get_host(shost) < 0) 1894 return; 1895 1896 data = scsi_prep_async_scan(shost); 1897 if (!data) { 1898 do_scsi_scan_host(shost); 1899 scsi_autopm_put_host(shost); 1900 return; 1901 } 1902 1903 /* register with the async subsystem so wait_for_device_probe() 1904 * will flush this work 1905 */ 1906 async_schedule(do_scan_async, data); 1907 1908 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 1909} 1910EXPORT_SYMBOL(scsi_scan_host); 1911 1912void scsi_forget_host(struct Scsi_Host *shost) 1913{ 1914 struct scsi_device *sdev; 1915 unsigned long flags; 1916 1917 restart: 1918 spin_lock_irqsave(shost->host_lock, flags); 1919 list_for_each_entry(sdev, &shost->__devices, siblings) { 1920 if (sdev->sdev_state == SDEV_DEL) 1921 continue; 1922 spin_unlock_irqrestore(shost->host_lock, flags); 1923 __scsi_remove_device(sdev); 1924 goto restart; 1925 } 1926 spin_unlock_irqrestore(shost->host_lock, flags); 1927} 1928 1929/** 1930 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself 1931 * @shost: Host that needs a scsi_device 1932 * 1933 * Lock status: None assumed. 1934 * 1935 * Returns: The scsi_device or NULL 1936 * 1937 * Notes: 1938 * Attach a single scsi_device to the Scsi_Host - this should 1939 * be made to look like a "pseudo-device" that points to the 1940 * HA itself. 1941 * 1942 * Note - this device is not accessible from any high-level 1943 * drivers (including generics), which is probably not 1944 * optimal. We can add hooks later to attach. 1945 */ 1946struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1947{ 1948 struct scsi_device *sdev = NULL; 1949 struct scsi_target *starget; 1950 1951 mutex_lock(&shost->scan_mutex); 1952 if (!scsi_host_scan_allowed(shost)) 1953 goto out; 1954 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1955 if (!starget) 1956 goto out; 1957 1958 sdev = scsi_alloc_sdev(starget, 0, NULL); 1959 if (sdev) 1960 sdev->borken = 0; 1961 else 1962 scsi_target_reap(starget); 1963 put_device(&starget->dev); 1964 out: 1965 mutex_unlock(&shost->scan_mutex); 1966 return sdev; 1967} 1968EXPORT_SYMBOL(scsi_get_host_dev); 1969 1970/** 1971 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself 1972 * @sdev: Host device to be freed 1973 * 1974 * Lock status: None assumed. 1975 * 1976 * Returns: Nothing 1977 */ 1978void scsi_free_host_dev(struct scsi_device *sdev) 1979{ 1980 BUG_ON(sdev->id != sdev->host->this_id); 1981 1982 __scsi_remove_device(sdev); 1983} 1984EXPORT_SYMBOL(scsi_free_host_dev); 1985 1986