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