1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * scsi_scan.c 4 * 5 * Copyright (C) 2000 Eric Youngdale, 6 * Copyright (C) 2002 Patrick Mansfield 7 * 8 * The general scanning/probing algorithm is as follows, exceptions are 9 * made to it depending on device specific flags, compilation options, and 10 * global variable (boot or module load time) settings. 11 * 12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a 13 * device attached, a scsi_device is allocated and setup for it. 14 * 15 * For every id of every channel on the given host: 16 * 17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no 18 * device or storage attached to LUN 0): 19 * 20 * If LUN 0 has a device attached, allocate and setup a 21 * scsi_device for it. 22 * 23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan 24 * all of the LUNs returned by the REPORT LUN; else, 25 * sequentially scan LUNs up until some maximum is reached, 26 * or a LUN is seen that cannot have a device attached to it. 27 */ 28 29 #include <linux/module.h> 30 #include <linux/moduleparam.h> 31 #include <linux/init.h> 32 #include <linux/blkdev.h> 33 #include <linux/delay.h> 34 #include <linux/kthread.h> 35 #include <linux/spinlock.h> 36 #include <linux/async.h> 37 #include <linux/slab.h> 38 #include <asm/unaligned.h> 39 40 #include <scsi/scsi.h> 41 #include <scsi/scsi_cmnd.h> 42 #include <scsi/scsi_device.h> 43 #include <scsi/scsi_driver.h> 44 #include <scsi/scsi_devinfo.h> 45 #include <scsi/scsi_host.h> 46 #include <scsi/scsi_transport.h> 47 #include <scsi/scsi_dh.h> 48 #include <scsi/scsi_eh.h> 49 50 #include "scsi_priv.h" 51 #include "scsi_logging.h" 52 53 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 54 " SCSI scanning, some SCSI devices might not be configured\n" 55 56 /* 57 * Default timeout 58 */ 59 #define SCSI_TIMEOUT (2*HZ) 60 #define SCSI_REPORT_LUNS_TIMEOUT (30*HZ) 61 62 /* 63 * Prefix values for the SCSI id's (stored in sysfs name field) 64 */ 65 #define SCSI_UID_SER_NUM 'S' 66 #define SCSI_UID_UNKNOWN 'Z' 67 68 /* 69 * Return values of some of the scanning functions. 70 * 71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 72 * includes allocation or general failures preventing IO from being sent. 73 * 74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 75 * on the given LUN. 76 * 77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 78 * given LUN. 79 */ 80 #define SCSI_SCAN_NO_RESPONSE 0 81 #define SCSI_SCAN_TARGET_PRESENT 1 82 #define SCSI_SCAN_LUN_PRESENT 2 83 84 static const char *scsi_null_device_strs = "nullnullnullnull"; 85 86 #define MAX_SCSI_LUNS 512 87 88 static u64 max_scsi_luns = MAX_SCSI_LUNS; 89 90 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR); 91 MODULE_PARM_DESC(max_luns, 92 "last scsi LUN (should be between 1 and 2^64-1)"); 93 94 #ifdef CONFIG_SCSI_SCAN_ASYNC 95 #define SCSI_SCAN_TYPE_DEFAULT "async" 96 #else 97 #define SCSI_SCAN_TYPE_DEFAULT "sync" 98 #endif 99 100 char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT; 101 102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), 103 S_IRUGO|S_IWUSR); 104 MODULE_PARM_DESC(scan, "sync, async, manual, or none. " 105 "Setting to 'manual' disables automatic scanning, but allows " 106 "for manual device scan via the 'scan' sysfs attribute."); 107 108 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; 109 110 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR); 111 MODULE_PARM_DESC(inq_timeout, 112 "Timeout (in seconds) waiting for devices to answer INQUIRY." 113 " Default is 20. Some devices may need more; most need less."); 114 115 /* This lock protects only this list */ 116 static DEFINE_SPINLOCK(async_scan_lock); 117 static LIST_HEAD(scanning_hosts); 118 119 struct async_scan_data { 120 struct list_head list; 121 struct Scsi_Host *shost; 122 struct completion prev_finished; 123 }; 124 125 /** 126 * scsi_complete_async_scans - Wait for asynchronous scans to complete 127 * 128 * When this function returns, any host which started scanning before 129 * this function was called will have finished its scan. Hosts which 130 * started scanning after this function was called may or may not have 131 * finished. 132 */ 133 int scsi_complete_async_scans(void) 134 { 135 struct async_scan_data *data; 136 137 do { 138 if (list_empty(&scanning_hosts)) 139 return 0; 140 /* If we can't get memory immediately, that's OK. Just 141 * sleep a little. Even if we never get memory, the async 142 * scans will finish eventually. 143 */ 144 data = kmalloc(sizeof(*data), GFP_KERNEL); 145 if (!data) 146 msleep(1); 147 } while (!data); 148 149 data->shost = NULL; 150 init_completion(&data->prev_finished); 151 152 spin_lock(&async_scan_lock); 153 /* Check that there's still somebody else on the list */ 154 if (list_empty(&scanning_hosts)) 155 goto done; 156 list_add_tail(&data->list, &scanning_hosts); 157 spin_unlock(&async_scan_lock); 158 159 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 160 wait_for_completion(&data->prev_finished); 161 162 spin_lock(&async_scan_lock); 163 list_del(&data->list); 164 if (!list_empty(&scanning_hosts)) { 165 struct async_scan_data *next = list_entry(scanning_hosts.next, 166 struct async_scan_data, list); 167 complete(&next->prev_finished); 168 } 169 done: 170 spin_unlock(&async_scan_lock); 171 172 kfree(data); 173 return 0; 174 } 175 176 /** 177 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 178 * @sdev: scsi device to send command to 179 * @result: area to store the result of the MODE SENSE 180 * 181 * Description: 182 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 183 * Called for BLIST_KEY devices. 184 **/ 185 static void scsi_unlock_floptical(struct scsi_device *sdev, 186 unsigned char *result) 187 { 188 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 189 190 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n"); 191 scsi_cmd[0] = MODE_SENSE; 192 scsi_cmd[1] = 0; 193 scsi_cmd[2] = 0x2e; 194 scsi_cmd[3] = 0; 195 scsi_cmd[4] = 0x2a; /* size */ 196 scsi_cmd[5] = 0; 197 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 198 SCSI_TIMEOUT, 3, NULL); 199 } 200 201 /** 202 * scsi_alloc_sdev - allocate and setup a scsi_Device 203 * @starget: which target to allocate a &scsi_device for 204 * @lun: which lun 205 * @hostdata: usually NULL and set by ->slave_alloc instead 206 * 207 * Description: 208 * Allocate, initialize for io, and return a pointer to a scsi_Device. 209 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 210 * adds scsi_Device to the appropriate list. 211 * 212 * Return value: 213 * scsi_Device pointer, or NULL on failure. 214 **/ 215 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 216 u64 lun, void *hostdata) 217 { 218 struct scsi_device *sdev; 219 int display_failure_msg = 1, ret; 220 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 221 222 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 223 GFP_ATOMIC); 224 if (!sdev) 225 goto out; 226 227 sdev->vendor = scsi_null_device_strs; 228 sdev->model = scsi_null_device_strs; 229 sdev->rev = scsi_null_device_strs; 230 sdev->host = shost; 231 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 232 sdev->id = starget->id; 233 sdev->lun = lun; 234 sdev->channel = starget->channel; 235 mutex_init(&sdev->state_mutex); 236 sdev->sdev_state = SDEV_CREATED; 237 INIT_LIST_HEAD(&sdev->siblings); 238 INIT_LIST_HEAD(&sdev->same_target_siblings); 239 INIT_LIST_HEAD(&sdev->cmd_list); 240 INIT_LIST_HEAD(&sdev->starved_entry); 241 INIT_LIST_HEAD(&sdev->event_list); 242 spin_lock_init(&sdev->list_lock); 243 mutex_init(&sdev->inquiry_mutex); 244 INIT_WORK(&sdev->event_work, scsi_evt_thread); 245 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 246 247 sdev->sdev_gendev.parent = get_device(&starget->dev); 248 sdev->sdev_target = starget; 249 250 /* usually NULL and set by ->slave_alloc instead */ 251 sdev->hostdata = hostdata; 252 253 /* if the device needs this changing, it may do so in the 254 * slave_configure function */ 255 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 256 257 /* 258 * Some low level driver could use device->type 259 */ 260 sdev->type = -1; 261 262 /* 263 * Assume that the device will have handshaking problems, 264 * and then fix this field later if it turns out it 265 * doesn't 266 */ 267 sdev->borken = 1; 268 269 if (shost_use_blk_mq(shost)) 270 sdev->request_queue = scsi_mq_alloc_queue(sdev); 271 else 272 sdev->request_queue = scsi_old_alloc_queue(sdev); 273 if (!sdev->request_queue) { 274 /* release fn is set up in scsi_sysfs_device_initialise, so 275 * have to free and put manually here */ 276 put_device(&starget->dev); 277 kfree(sdev); 278 goto out; 279 } 280 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); 281 sdev->request_queue->queuedata = sdev; 282 283 if (!shost_use_blk_mq(sdev->host)) { 284 blk_queue_init_tags(sdev->request_queue, 285 sdev->host->cmd_per_lun, shost->bqt, 286 shost->hostt->tag_alloc_policy); 287 } 288 scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ? 289 sdev->host->cmd_per_lun : 1); 290 291 scsi_sysfs_device_initialize(sdev); 292 293 if (shost->hostt->slave_alloc) { 294 ret = shost->hostt->slave_alloc(sdev); 295 if (ret) { 296 /* 297 * if LLDD reports slave not present, don't clutter 298 * console with alloc failure messages 299 */ 300 if (ret == -ENXIO) 301 display_failure_msg = 0; 302 goto out_device_destroy; 303 } 304 } 305 306 return sdev; 307 308 out_device_destroy: 309 __scsi_remove_device(sdev); 310 out: 311 if (display_failure_msg) 312 printk(ALLOC_FAILURE_MSG, __func__); 313 return NULL; 314 } 315 316 static void scsi_target_destroy(struct scsi_target *starget) 317 { 318 struct device *dev = &starget->dev; 319 struct Scsi_Host *shost = dev_to_shost(dev->parent); 320 unsigned long flags; 321 322 BUG_ON(starget->state == STARGET_DEL); 323 starget->state = STARGET_DEL; 324 transport_destroy_device(dev); 325 spin_lock_irqsave(shost->host_lock, flags); 326 if (shost->hostt->target_destroy) 327 shost->hostt->target_destroy(starget); 328 list_del_init(&starget->siblings); 329 spin_unlock_irqrestore(shost->host_lock, flags); 330 put_device(dev); 331 } 332 333 static void scsi_target_dev_release(struct device *dev) 334 { 335 struct device *parent = dev->parent; 336 struct scsi_target *starget = to_scsi_target(dev); 337 338 kfree(starget); 339 put_device(parent); 340 } 341 342 static struct device_type scsi_target_type = { 343 .name = "scsi_target", 344 .release = scsi_target_dev_release, 345 }; 346 347 int scsi_is_target_device(const struct device *dev) 348 { 349 return dev->type == &scsi_target_type; 350 } 351 EXPORT_SYMBOL(scsi_is_target_device); 352 353 static struct scsi_target *__scsi_find_target(struct device *parent, 354 int channel, uint id) 355 { 356 struct scsi_target *starget, *found_starget = NULL; 357 struct Scsi_Host *shost = dev_to_shost(parent); 358 /* 359 * Search for an existing target for this sdev. 360 */ 361 list_for_each_entry(starget, &shost->__targets, siblings) { 362 if (starget->id == id && 363 starget->channel == channel) { 364 found_starget = starget; 365 break; 366 } 367 } 368 if (found_starget) 369 get_device(&found_starget->dev); 370 371 return found_starget; 372 } 373 374 /** 375 * scsi_target_reap_ref_release - remove target from visibility 376 * @kref: the reap_ref in the target being released 377 * 378 * Called on last put of reap_ref, which is the indication that no device 379 * under this target is visible anymore, so render the target invisible in 380 * sysfs. Note: we have to be in user context here because the target reaps 381 * should be done in places where the scsi device visibility is being removed. 382 */ 383 static void scsi_target_reap_ref_release(struct kref *kref) 384 { 385 struct scsi_target *starget 386 = container_of(kref, struct scsi_target, reap_ref); 387 388 /* 389 * if we get here and the target is still in a CREATED state that 390 * means it was allocated but never made visible (because a scan 391 * turned up no LUNs), so don't call device_del() on it. 392 */ 393 if ((starget->state != STARGET_CREATED) && 394 (starget->state != STARGET_CREATED_REMOVE)) { 395 transport_remove_device(&starget->dev); 396 device_del(&starget->dev); 397 } 398 scsi_target_destroy(starget); 399 } 400 401 static void scsi_target_reap_ref_put(struct scsi_target *starget) 402 { 403 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 404 } 405 406 /** 407 * scsi_alloc_target - allocate a new or find an existing target 408 * @parent: parent of the target (need not be a scsi host) 409 * @channel: target channel number (zero if no channels) 410 * @id: target id number 411 * 412 * Return an existing target if one exists, provided it hasn't already 413 * gone into STARGET_DEL state, otherwise allocate a new target. 414 * 415 * The target is returned with an incremented reference, so the caller 416 * is responsible for both reaping and doing a last put 417 */ 418 static struct scsi_target *scsi_alloc_target(struct device *parent, 419 int channel, uint id) 420 { 421 struct Scsi_Host *shost = dev_to_shost(parent); 422 struct device *dev = NULL; 423 unsigned long flags; 424 const int size = sizeof(struct scsi_target) 425 + shost->transportt->target_size; 426 struct scsi_target *starget; 427 struct scsi_target *found_target; 428 int error, ref_got; 429 430 starget = kzalloc(size, GFP_KERNEL); 431 if (!starget) { 432 printk(KERN_ERR "%s: allocation failure\n", __func__); 433 return NULL; 434 } 435 dev = &starget->dev; 436 device_initialize(dev); 437 kref_init(&starget->reap_ref); 438 dev->parent = get_device(parent); 439 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 440 dev->bus = &scsi_bus_type; 441 dev->type = &scsi_target_type; 442 starget->id = id; 443 starget->channel = channel; 444 starget->can_queue = 0; 445 INIT_LIST_HEAD(&starget->siblings); 446 INIT_LIST_HEAD(&starget->devices); 447 starget->state = STARGET_CREATED; 448 starget->scsi_level = SCSI_2; 449 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 450 retry: 451 spin_lock_irqsave(shost->host_lock, flags); 452 453 found_target = __scsi_find_target(parent, channel, id); 454 if (found_target) 455 goto found; 456 457 list_add_tail(&starget->siblings, &shost->__targets); 458 spin_unlock_irqrestore(shost->host_lock, flags); 459 /* allocate and add */ 460 transport_setup_device(dev); 461 if (shost->hostt->target_alloc) { 462 error = shost->hostt->target_alloc(starget); 463 464 if(error) { 465 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 466 /* don't want scsi_target_reap to do the final 467 * put because it will be under the host lock */ 468 scsi_target_destroy(starget); 469 return NULL; 470 } 471 } 472 get_device(dev); 473 474 return starget; 475 476 found: 477 /* 478 * release routine already fired if kref is zero, so if we can still 479 * take the reference, the target must be alive. If we can't, it must 480 * be dying and we need to wait for a new target 481 */ 482 ref_got = kref_get_unless_zero(&found_target->reap_ref); 483 484 spin_unlock_irqrestore(shost->host_lock, flags); 485 if (ref_got) { 486 put_device(dev); 487 return found_target; 488 } 489 /* 490 * Unfortunately, we found a dying target; need to wait until it's 491 * dead before we can get a new one. There is an anomaly here. We 492 * *should* call scsi_target_reap() to balance the kref_get() of the 493 * reap_ref above. However, since the target being released, it's 494 * already invisible and the reap_ref is irrelevant. If we call 495 * scsi_target_reap() we might spuriously do another device_del() on 496 * an already invisible target. 497 */ 498 put_device(&found_target->dev); 499 /* 500 * length of time is irrelevant here, we just want to yield the CPU 501 * for a tick to avoid busy waiting for the target to die. 502 */ 503 msleep(1); 504 goto retry; 505 } 506 507 /** 508 * scsi_target_reap - check to see if target is in use and destroy if not 509 * @starget: target to be checked 510 * 511 * This is used after removing a LUN or doing a last put of the target 512 * it checks atomically that nothing is using the target and removes 513 * it if so. 514 */ 515 void scsi_target_reap(struct scsi_target *starget) 516 { 517 /* 518 * serious problem if this triggers: STARGET_DEL is only set in the if 519 * the reap_ref drops to zero, so we're trying to do another final put 520 * on an already released kref 521 */ 522 BUG_ON(starget->state == STARGET_DEL); 523 scsi_target_reap_ref_put(starget); 524 } 525 526 /** 527 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 528 * INQUIRY result string 529 * @s: INQUIRY result string to sanitize 530 * @len: length of the string 531 * 532 * Description: 533 * The SCSI spec says that INQUIRY vendor, product, and revision 534 * strings must consist entirely of graphic ASCII characters, 535 * padded on the right with spaces. Since not all devices obey 536 * this rule, we will replace non-graphic or non-ASCII characters 537 * with spaces. Exception: a NUL character is interpreted as a 538 * string terminator, so all the following characters are set to 539 * spaces. 540 **/ 541 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 542 { 543 int terminated = 0; 544 545 for (; len > 0; (--len, ++s)) { 546 if (*s == 0) 547 terminated = 1; 548 if (terminated || *s < 0x20 || *s > 0x7e) 549 *s = ' '; 550 } 551 } 552 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 553 554 /** 555 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 556 * @sdev: scsi_device to probe 557 * @inq_result: area to store the INQUIRY result 558 * @result_len: len of inq_result 559 * @bflags: store any bflags found here 560 * 561 * Description: 562 * Probe the lun associated with @req using a standard SCSI INQUIRY; 563 * 564 * If the INQUIRY is successful, zero is returned and the 565 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 566 * are copied to the scsi_device any flags value is stored in *@bflags. 567 **/ 568 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 569 int result_len, blist_flags_t *bflags) 570 { 571 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 572 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 573 int response_len = 0; 574 int pass, count, result; 575 struct scsi_sense_hdr sshdr; 576 577 *bflags = 0; 578 579 /* Perform up to 3 passes. The first pass uses a conservative 580 * transfer length of 36 unless sdev->inquiry_len specifies a 581 * different value. */ 582 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 583 try_inquiry_len = first_inquiry_len; 584 pass = 1; 585 586 next_pass: 587 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 588 "scsi scan: INQUIRY pass %d length %d\n", 589 pass, try_inquiry_len)); 590 591 /* Each pass gets up to three chances to ignore Unit Attention */ 592 for (count = 0; count < 3; ++count) { 593 int resid; 594 595 memset(scsi_cmd, 0, 6); 596 scsi_cmd[0] = INQUIRY; 597 scsi_cmd[4] = (unsigned char) try_inquiry_len; 598 599 memset(inq_result, 0, try_inquiry_len); 600 601 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 602 inq_result, try_inquiry_len, &sshdr, 603 HZ / 2 + HZ * scsi_inq_timeout, 3, 604 &resid); 605 606 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 607 "scsi scan: INQUIRY %s with code 0x%x\n", 608 result ? "failed" : "successful", result)); 609 610 if (result) { 611 /* 612 * not-ready to ready transition [asc/ascq=0x28/0x0] 613 * or power-on, reset [asc/ascq=0x29/0x0], continue. 614 * INQUIRY should not yield UNIT_ATTENTION 615 * but many buggy devices do so anyway. 616 */ 617 if ((driver_byte(result) & DRIVER_SENSE) && 618 scsi_sense_valid(&sshdr)) { 619 if ((sshdr.sense_key == UNIT_ATTENTION) && 620 ((sshdr.asc == 0x28) || 621 (sshdr.asc == 0x29)) && 622 (sshdr.ascq == 0)) 623 continue; 624 } 625 } else { 626 /* 627 * if nothing was transferred, we try 628 * again. It's a workaround for some USB 629 * devices. 630 */ 631 if (resid == try_inquiry_len) 632 continue; 633 } 634 break; 635 } 636 637 if (result == 0) { 638 scsi_sanitize_inquiry_string(&inq_result[8], 8); 639 scsi_sanitize_inquiry_string(&inq_result[16], 16); 640 scsi_sanitize_inquiry_string(&inq_result[32], 4); 641 642 response_len = inq_result[4] + 5; 643 if (response_len > 255) 644 response_len = first_inquiry_len; /* sanity */ 645 646 /* 647 * Get any flags for this device. 648 * 649 * XXX add a bflags to scsi_device, and replace the 650 * corresponding bit fields in scsi_device, so bflags 651 * need not be passed as an argument. 652 */ 653 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 654 &inq_result[16]); 655 656 /* When the first pass succeeds we gain information about 657 * what larger transfer lengths might work. */ 658 if (pass == 1) { 659 if (BLIST_INQUIRY_36 & *bflags) 660 next_inquiry_len = 36; 661 else if (sdev->inquiry_len) 662 next_inquiry_len = sdev->inquiry_len; 663 else 664 next_inquiry_len = response_len; 665 666 /* If more data is available perform the second pass */ 667 if (next_inquiry_len > try_inquiry_len) { 668 try_inquiry_len = next_inquiry_len; 669 pass = 2; 670 goto next_pass; 671 } 672 } 673 674 } else if (pass == 2) { 675 sdev_printk(KERN_INFO, sdev, 676 "scsi scan: %d byte inquiry failed. " 677 "Consider BLIST_INQUIRY_36 for this device\n", 678 try_inquiry_len); 679 680 /* If this pass failed, the third pass goes back and transfers 681 * the same amount as we successfully got in the first pass. */ 682 try_inquiry_len = first_inquiry_len; 683 pass = 3; 684 goto next_pass; 685 } 686 687 /* If the last transfer attempt got an error, assume the 688 * peripheral doesn't exist or is dead. */ 689 if (result) 690 return -EIO; 691 692 /* Don't report any more data than the device says is valid */ 693 sdev->inquiry_len = min(try_inquiry_len, response_len); 694 695 /* 696 * XXX Abort if the response length is less than 36? If less than 697 * 32, the lookup of the device flags (above) could be invalid, 698 * and it would be possible to take an incorrect action - we do 699 * not want to hang because of a short INQUIRY. On the flip side, 700 * if the device is spun down or becoming ready (and so it gives a 701 * short INQUIRY), an abort here prevents any further use of the 702 * device, including spin up. 703 * 704 * On the whole, the best approach seems to be to assume the first 705 * 36 bytes are valid no matter what the device says. That's 706 * better than copying < 36 bytes to the inquiry-result buffer 707 * and displaying garbage for the Vendor, Product, or Revision 708 * strings. 709 */ 710 if (sdev->inquiry_len < 36) { 711 if (!sdev->host->short_inquiry) { 712 shost_printk(KERN_INFO, sdev->host, 713 "scsi scan: INQUIRY result too short (%d)," 714 " using 36\n", sdev->inquiry_len); 715 sdev->host->short_inquiry = 1; 716 } 717 sdev->inquiry_len = 36; 718 } 719 720 /* 721 * Related to the above issue: 722 * 723 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 724 * and if not ready, sent a START_STOP to start (maybe spin up) and 725 * then send the INQUIRY again, since the INQUIRY can change after 726 * a device is initialized. 727 * 728 * Ideally, start a device if explicitly asked to do so. This 729 * assumes that a device is spun up on power on, spun down on 730 * request, and then spun up on request. 731 */ 732 733 /* 734 * The scanning code needs to know the scsi_level, even if no 735 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 736 * non-zero LUNs can be scanned. 737 */ 738 sdev->scsi_level = inq_result[2] & 0x07; 739 if (sdev->scsi_level >= 2 || 740 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 741 sdev->scsi_level++; 742 sdev->sdev_target->scsi_level = sdev->scsi_level; 743 744 /* 745 * If SCSI-2 or lower, and if the transport requires it, 746 * store the LUN value in CDB[1]. 747 */ 748 sdev->lun_in_cdb = 0; 749 if (sdev->scsi_level <= SCSI_2 && 750 sdev->scsi_level != SCSI_UNKNOWN && 751 !sdev->host->no_scsi2_lun_in_cdb) 752 sdev->lun_in_cdb = 1; 753 754 return 0; 755 } 756 757 /** 758 * scsi_add_lun - allocate and fully initialze a scsi_device 759 * @sdev: holds information to be stored in the new scsi_device 760 * @inq_result: holds the result of a previous INQUIRY to the LUN 761 * @bflags: black/white list flag 762 * @async: 1 if this device is being scanned asynchronously 763 * 764 * Description: 765 * Initialize the scsi_device @sdev. Optionally set fields based 766 * on values in *@bflags. 767 * 768 * Return: 769 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 770 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 771 **/ 772 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 773 blist_flags_t *bflags, int async) 774 { 775 int ret; 776 777 /* 778 * XXX do not save the inquiry, since it can change underneath us, 779 * save just vendor/model/rev. 780 * 781 * Rather than save it and have an ioctl that retrieves the saved 782 * value, have an ioctl that executes the same INQUIRY code used 783 * in scsi_probe_lun, let user level programs doing INQUIRY 784 * scanning run at their own risk, or supply a user level program 785 * that can correctly scan. 786 */ 787 788 /* 789 * Copy at least 36 bytes of INQUIRY data, so that we don't 790 * dereference unallocated memory when accessing the Vendor, 791 * Product, and Revision strings. Badly behaved devices may set 792 * the INQUIRY Additional Length byte to a small value, indicating 793 * these strings are invalid, but often they contain plausible data 794 * nonetheless. It doesn't matter if the device sent < 36 bytes 795 * total, since scsi_probe_lun() initializes inq_result with 0s. 796 */ 797 sdev->inquiry = kmemdup(inq_result, 798 max_t(size_t, sdev->inquiry_len, 36), 799 GFP_ATOMIC); 800 if (sdev->inquiry == NULL) 801 return SCSI_SCAN_NO_RESPONSE; 802 803 sdev->vendor = (char *) (sdev->inquiry + 8); 804 sdev->model = (char *) (sdev->inquiry + 16); 805 sdev->rev = (char *) (sdev->inquiry + 32); 806 807 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 808 /* 809 * sata emulation layer device. This is a hack to work around 810 * the SATL power management specifications which state that 811 * when the SATL detects the device has gone into standby 812 * mode, it shall respond with NOT READY. 813 */ 814 sdev->allow_restart = 1; 815 } 816 817 if (*bflags & BLIST_ISROM) { 818 sdev->type = TYPE_ROM; 819 sdev->removable = 1; 820 } else { 821 sdev->type = (inq_result[0] & 0x1f); 822 sdev->removable = (inq_result[1] & 0x80) >> 7; 823 824 /* 825 * some devices may respond with wrong type for 826 * well-known logical units. Force well-known type 827 * to enumerate them correctly. 828 */ 829 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 830 sdev_printk(KERN_WARNING, sdev, 831 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 832 __func__, sdev->type, (unsigned int)sdev->lun); 833 sdev->type = TYPE_WLUN; 834 } 835 836 } 837 838 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 839 /* RBC and MMC devices can return SCSI-3 compliance and yet 840 * still not support REPORT LUNS, so make them act as 841 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 842 * specifically set */ 843 if ((*bflags & BLIST_REPORTLUN2) == 0) 844 *bflags |= BLIST_NOREPORTLUN; 845 } 846 847 /* 848 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 849 * spec says: The device server is capable of supporting the 850 * specified peripheral device type on this logical unit. However, 851 * the physical device is not currently connected to this logical 852 * unit. 853 * 854 * The above is vague, as it implies that we could treat 001 and 855 * 011 the same. Stay compatible with previous code, and create a 856 * scsi_device for a PQ of 1 857 * 858 * Don't set the device offline here; rather let the upper 859 * level drivers eval the PQ to decide whether they should 860 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 861 */ 862 863 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 864 sdev->lockable = sdev->removable; 865 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 866 867 if (sdev->scsi_level >= SCSI_3 || 868 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 869 sdev->ppr = 1; 870 if (inq_result[7] & 0x60) 871 sdev->wdtr = 1; 872 if (inq_result[7] & 0x10) 873 sdev->sdtr = 1; 874 875 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 876 "ANSI: %d%s\n", scsi_device_type(sdev->type), 877 sdev->vendor, sdev->model, sdev->rev, 878 sdev->inq_periph_qual, inq_result[2] & 0x07, 879 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 880 881 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 882 !(*bflags & BLIST_NOTQ)) { 883 sdev->tagged_supported = 1; 884 sdev->simple_tags = 1; 885 } 886 887 /* 888 * Some devices (Texel CD ROM drives) have handshaking problems 889 * when used with the Seagate controllers. borken is initialized 890 * to 1, and then set it to 0 here. 891 */ 892 if ((*bflags & BLIST_BORKEN) == 0) 893 sdev->borken = 0; 894 895 if (*bflags & BLIST_NO_ULD_ATTACH) 896 sdev->no_uld_attach = 1; 897 898 /* 899 * Apparently some really broken devices (contrary to the SCSI 900 * standards) need to be selected without asserting ATN 901 */ 902 if (*bflags & BLIST_SELECT_NO_ATN) 903 sdev->select_no_atn = 1; 904 905 /* 906 * Maximum 512 sector transfer length 907 * broken RA4x00 Compaq Disk Array 908 */ 909 if (*bflags & BLIST_MAX_512) 910 blk_queue_max_hw_sectors(sdev->request_queue, 512); 911 /* 912 * Max 1024 sector transfer length for targets that report incorrect 913 * max/optimal lengths and relied on the old block layer safe default 914 */ 915 else if (*bflags & BLIST_MAX_1024) 916 blk_queue_max_hw_sectors(sdev->request_queue, 1024); 917 918 /* 919 * Some devices may not want to have a start command automatically 920 * issued when a device is added. 921 */ 922 if (*bflags & BLIST_NOSTARTONADD) 923 sdev->no_start_on_add = 1; 924 925 if (*bflags & BLIST_SINGLELUN) 926 scsi_target(sdev)->single_lun = 1; 927 928 sdev->use_10_for_rw = 1; 929 930 /* some devices don't like REPORT SUPPORTED OPERATION CODES 931 * and will simply timeout causing sd_mod init to take a very 932 * very long time */ 933 if (*bflags & BLIST_NO_RSOC) 934 sdev->no_report_opcodes = 1; 935 936 /* set the device running here so that slave configure 937 * may do I/O */ 938 mutex_lock(&sdev->state_mutex); 939 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 940 if (ret) 941 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 942 mutex_unlock(&sdev->state_mutex); 943 944 if (ret) { 945 sdev_printk(KERN_ERR, sdev, 946 "in wrong state %s to complete scan\n", 947 scsi_device_state_name(sdev->sdev_state)); 948 return SCSI_SCAN_NO_RESPONSE; 949 } 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 if (*bflags & BLIST_UNMAP_LIMIT_WS) 961 sdev->unmap_limit_for_ws = 1; 962 963 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 964 965 if (*bflags & BLIST_TRY_VPD_PAGES) 966 sdev->try_vpd_pages = 1; 967 else if (*bflags & BLIST_SKIP_VPD_PAGES) 968 sdev->skip_vpd_pages = 1; 969 970 transport_configure_device(&sdev->sdev_gendev); 971 972 if (sdev->host->hostt->slave_configure) { 973 ret = sdev->host->hostt->slave_configure(sdev); 974 if (ret) { 975 /* 976 * if LLDD reports slave not present, don't clutter 977 * console with alloc failure messages 978 */ 979 if (ret != -ENXIO) { 980 sdev_printk(KERN_ERR, sdev, 981 "failed to configure device\n"); 982 } 983 return SCSI_SCAN_NO_RESPONSE; 984 } 985 } 986 987 if (sdev->scsi_level >= SCSI_3) 988 scsi_attach_vpd(sdev); 989 990 sdev->max_queue_depth = sdev->queue_depth; 991 sdev->sdev_bflags = *bflags; 992 993 /* 994 * Ok, the device is now all set up, we can 995 * register it and tell the rest of the kernel 996 * about it. 997 */ 998 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 999 return SCSI_SCAN_NO_RESPONSE; 1000 1001 return SCSI_SCAN_LUN_PRESENT; 1002 } 1003 1004 #ifdef CONFIG_SCSI_LOGGING 1005 /** 1006 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 1007 * @buf: Output buffer with at least end-first+1 bytes of space 1008 * @inq: Inquiry buffer (input) 1009 * @first: Offset of string into inq 1010 * @end: Index after last character in inq 1011 */ 1012 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1013 unsigned first, unsigned end) 1014 { 1015 unsigned term = 0, idx; 1016 1017 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1018 if (inq[idx+first] > ' ') { 1019 buf[idx] = inq[idx+first]; 1020 term = idx+1; 1021 } else { 1022 buf[idx] = ' '; 1023 } 1024 } 1025 buf[term] = 0; 1026 return buf; 1027 } 1028 #endif 1029 1030 /** 1031 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1032 * @starget: pointer to target device structure 1033 * @lun: LUN of target device 1034 * @bflagsp: store bflags here if not NULL 1035 * @sdevp: probe the LUN corresponding to this scsi_device 1036 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1037 * needed on first scan 1038 * @hostdata: passed to scsi_alloc_sdev() 1039 * 1040 * Description: 1041 * Call scsi_probe_lun, if a LUN with an attached device is found, 1042 * allocate and set it up by calling scsi_add_lun. 1043 * 1044 * Return: 1045 * 1046 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1047 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1048 * attached at the LUN 1049 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1050 **/ 1051 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1052 u64 lun, blist_flags_t *bflagsp, 1053 struct scsi_device **sdevp, 1054 enum scsi_scan_mode rescan, 1055 void *hostdata) 1056 { 1057 struct scsi_device *sdev; 1058 unsigned char *result; 1059 blist_flags_t bflags; 1060 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1061 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1062 1063 /* 1064 * The rescan flag is used as an optimization, the first scan of a 1065 * host adapter calls into here with rescan == 0. 1066 */ 1067 sdev = scsi_device_lookup_by_target(starget, lun); 1068 if (sdev) { 1069 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1070 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1071 "scsi scan: device exists on %s\n", 1072 dev_name(&sdev->sdev_gendev))); 1073 if (sdevp) 1074 *sdevp = sdev; 1075 else 1076 scsi_device_put(sdev); 1077 1078 if (bflagsp) 1079 *bflagsp = scsi_get_device_flags(sdev, 1080 sdev->vendor, 1081 sdev->model); 1082 return SCSI_SCAN_LUN_PRESENT; 1083 } 1084 scsi_device_put(sdev); 1085 } else 1086 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1087 if (!sdev) 1088 goto out; 1089 1090 result = kmalloc(result_len, GFP_ATOMIC | 1091 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1092 if (!result) 1093 goto out_free_sdev; 1094 1095 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1096 goto out_free_result; 1097 1098 if (bflagsp) 1099 *bflagsp = bflags; 1100 /* 1101 * result contains valid SCSI INQUIRY data. 1102 */ 1103 if ((result[0] >> 5) == 3) { 1104 /* 1105 * For a Peripheral qualifier 3 (011b), the SCSI 1106 * spec says: The device server is not capable of 1107 * supporting a physical device on this logical 1108 * unit. 1109 * 1110 * For disks, this implies that there is no 1111 * logical disk configured at sdev->lun, but there 1112 * is a target id responding. 1113 */ 1114 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1115 " peripheral qualifier of 3, device not" 1116 " added\n")) 1117 if (lun == 0) { 1118 SCSI_LOG_SCAN_BUS(1, { 1119 unsigned char vend[9]; 1120 unsigned char mod[17]; 1121 1122 sdev_printk(KERN_INFO, sdev, 1123 "scsi scan: consider passing scsi_mod." 1124 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1125 scsi_inq_str(vend, result, 8, 16), 1126 scsi_inq_str(mod, result, 16, 32)); 1127 }); 1128 1129 } 1130 1131 res = SCSI_SCAN_TARGET_PRESENT; 1132 goto out_free_result; 1133 } 1134 1135 /* 1136 * Some targets may set slight variations of PQ and PDT to signal 1137 * that no LUN is present, so don't add sdev in these cases. 1138 * Two specific examples are: 1139 * 1) NetApp targets: return PQ=1, PDT=0x1f 1140 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1141 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1142 * 1143 * References: 1144 * 1) SCSI SPC-3, pp. 145-146 1145 * PQ=1: "A peripheral device having the specified peripheral 1146 * device type is not connected to this logical unit. However, the 1147 * device server is capable of supporting the specified peripheral 1148 * device type on this logical unit." 1149 * PDT=0x1f: "Unknown or no device type" 1150 * 2) USB UFI 1.0, p. 20 1151 * PDT=00h Direct-access device (floppy) 1152 * PDT=1Fh none (no FDD connected to the requested logical unit) 1153 */ 1154 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1155 (result[0] & 0x1f) == 0x1f && 1156 !scsi_is_wlun(lun)) { 1157 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1158 "scsi scan: peripheral device type" 1159 " of 31, no device added\n")); 1160 res = SCSI_SCAN_TARGET_PRESENT; 1161 goto out_free_result; 1162 } 1163 1164 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1165 if (res == SCSI_SCAN_LUN_PRESENT) { 1166 if (bflags & BLIST_KEY) { 1167 sdev->lockable = 0; 1168 scsi_unlock_floptical(sdev, result); 1169 } 1170 } 1171 1172 out_free_result: 1173 kfree(result); 1174 out_free_sdev: 1175 if (res == SCSI_SCAN_LUN_PRESENT) { 1176 if (sdevp) { 1177 if (scsi_device_get(sdev) == 0) { 1178 *sdevp = sdev; 1179 } else { 1180 __scsi_remove_device(sdev); 1181 res = SCSI_SCAN_NO_RESPONSE; 1182 } 1183 } 1184 } else 1185 __scsi_remove_device(sdev); 1186 out: 1187 return res; 1188 } 1189 1190 /** 1191 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1192 * @starget: pointer to target structure to scan 1193 * @bflags: black/white list flag for LUN 0 1194 * @scsi_level: Which version of the standard does this device adhere to 1195 * @rescan: passed to scsi_probe_add_lun() 1196 * 1197 * Description: 1198 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1199 * scanned) to some maximum lun until a LUN is found with no device 1200 * attached. Use the bflags to figure out any oddities. 1201 * 1202 * Modifies sdevscan->lun. 1203 **/ 1204 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1205 blist_flags_t bflags, int scsi_level, 1206 enum scsi_scan_mode rescan) 1207 { 1208 uint max_dev_lun; 1209 u64 sparse_lun, lun; 1210 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1211 1212 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1213 "scsi scan: Sequential scan\n")); 1214 1215 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1216 /* 1217 * If this device is known to support sparse multiple units, 1218 * override the other settings, and scan all of them. Normally, 1219 * SCSI-3 devices should be scanned via the REPORT LUNS. 1220 */ 1221 if (bflags & BLIST_SPARSELUN) { 1222 max_dev_lun = shost->max_lun; 1223 sparse_lun = 1; 1224 } else 1225 sparse_lun = 0; 1226 1227 /* 1228 * If less than SCSI_1_CCS, and no special lun scanning, stop 1229 * scanning; this matches 2.4 behaviour, but could just be a bug 1230 * (to continue scanning a SCSI_1_CCS device). 1231 * 1232 * This test is broken. We might not have any device on lun0 for 1233 * a sparselun device, and if that's the case then how would we 1234 * know the real scsi_level, eh? It might make sense to just not 1235 * scan any SCSI_1 device for non-0 luns, but that check would best 1236 * go into scsi_alloc_sdev() and just have it return null when asked 1237 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1238 * 1239 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1240 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1241 == 0)) 1242 return; 1243 */ 1244 /* 1245 * If this device is known to support multiple units, override 1246 * the other settings, and scan all of them. 1247 */ 1248 if (bflags & BLIST_FORCELUN) 1249 max_dev_lun = shost->max_lun; 1250 /* 1251 * REGAL CDC-4X: avoid hang after LUN 4 1252 */ 1253 if (bflags & BLIST_MAX5LUN) 1254 max_dev_lun = min(5U, max_dev_lun); 1255 /* 1256 * Do not scan SCSI-2 or lower device past LUN 7, unless 1257 * BLIST_LARGELUN. 1258 */ 1259 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1260 max_dev_lun = min(8U, max_dev_lun); 1261 else 1262 max_dev_lun = min(256U, max_dev_lun); 1263 1264 /* 1265 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1266 * until we reach the max, or no LUN is found and we are not 1267 * sparse_lun. 1268 */ 1269 for (lun = 1; lun < max_dev_lun; ++lun) 1270 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1271 NULL) != SCSI_SCAN_LUN_PRESENT) && 1272 !sparse_lun) 1273 return; 1274 } 1275 1276 /** 1277 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1278 * @starget: which target 1279 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1280 * @rescan: nonzero if we can skip code only needed on first scan 1281 * 1282 * Description: 1283 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1284 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1285 * 1286 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1287 * LUNs even if it's older than SCSI-3. 1288 * If BLIST_NOREPORTLUN is set, return 1 always. 1289 * If BLIST_NOLUN is set, return 0 always. 1290 * If starget->no_report_luns is set, return 1 always. 1291 * 1292 * Return: 1293 * 0: scan completed (or no memory, so further scanning is futile) 1294 * 1: could not scan with REPORT LUN 1295 **/ 1296 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1297 enum scsi_scan_mode rescan) 1298 { 1299 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1300 unsigned int length; 1301 u64 lun; 1302 unsigned int num_luns; 1303 unsigned int retries; 1304 int result; 1305 struct scsi_lun *lunp, *lun_data; 1306 struct scsi_sense_hdr sshdr; 1307 struct scsi_device *sdev; 1308 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1309 int ret = 0; 1310 1311 /* 1312 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1313 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1314 * support more than 8 LUNs. 1315 * Don't attempt if the target doesn't support REPORT LUNS. 1316 */ 1317 if (bflags & BLIST_NOREPORTLUN) 1318 return 1; 1319 if (starget->scsi_level < SCSI_2 && 1320 starget->scsi_level != SCSI_UNKNOWN) 1321 return 1; 1322 if (starget->scsi_level < SCSI_3 && 1323 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1324 return 1; 1325 if (bflags & BLIST_NOLUN) 1326 return 0; 1327 if (starget->no_report_luns) 1328 return 1; 1329 1330 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1331 sdev = scsi_alloc_sdev(starget, 0, NULL); 1332 if (!sdev) 1333 return 0; 1334 if (scsi_device_get(sdev)) { 1335 __scsi_remove_device(sdev); 1336 return 0; 1337 } 1338 } 1339 1340 /* 1341 * Allocate enough to hold the header (the same size as one scsi_lun) 1342 * plus the number of luns we are requesting. 511 was the default 1343 * value of the now removed max_report_luns parameter. 1344 */ 1345 length = (511 + 1) * sizeof(struct scsi_lun); 1346 retry: 1347 lun_data = kmalloc(length, GFP_KERNEL | 1348 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1349 if (!lun_data) { 1350 printk(ALLOC_FAILURE_MSG, __func__); 1351 goto out; 1352 } 1353 1354 scsi_cmd[0] = REPORT_LUNS; 1355 1356 /* 1357 * bytes 1 - 5: reserved, set to zero. 1358 */ 1359 memset(&scsi_cmd[1], 0, 5); 1360 1361 /* 1362 * bytes 6 - 9: length of the command. 1363 */ 1364 put_unaligned_be32(length, &scsi_cmd[6]); 1365 1366 scsi_cmd[10] = 0; /* reserved */ 1367 scsi_cmd[11] = 0; /* control */ 1368 1369 /* 1370 * We can get a UNIT ATTENTION, for example a power on/reset, so 1371 * retry a few times (like sd.c does for TEST UNIT READY). 1372 * Experience shows some combinations of adapter/devices get at 1373 * least two power on/resets. 1374 * 1375 * Illegal requests (for devices that do not support REPORT LUNS) 1376 * should come through as a check condition, and will not generate 1377 * a retry. 1378 */ 1379 for (retries = 0; retries < 3; retries++) { 1380 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1381 "scsi scan: Sending REPORT LUNS to (try %d)\n", 1382 retries)); 1383 1384 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1385 lun_data, length, &sshdr, 1386 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL); 1387 1388 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1389 "scsi scan: REPORT LUNS" 1390 " %s (try %d) result 0x%x\n", 1391 result ? "failed" : "successful", 1392 retries, result)); 1393 if (result == 0) 1394 break; 1395 else if (scsi_sense_valid(&sshdr)) { 1396 if (sshdr.sense_key != UNIT_ATTENTION) 1397 break; 1398 } 1399 } 1400 1401 if (result) { 1402 /* 1403 * The device probably does not support a REPORT LUN command 1404 */ 1405 ret = 1; 1406 goto out_err; 1407 } 1408 1409 /* 1410 * Get the length from the first four bytes of lun_data. 1411 */ 1412 if (get_unaligned_be32(lun_data->scsi_lun) + 1413 sizeof(struct scsi_lun) > length) { 1414 length = get_unaligned_be32(lun_data->scsi_lun) + 1415 sizeof(struct scsi_lun); 1416 kfree(lun_data); 1417 goto retry; 1418 } 1419 length = get_unaligned_be32(lun_data->scsi_lun); 1420 1421 num_luns = (length / sizeof(struct scsi_lun)); 1422 1423 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1424 "scsi scan: REPORT LUN scan\n")); 1425 1426 /* 1427 * Scan the luns in lun_data. The entry at offset 0 is really 1428 * the header, so start at 1 and go up to and including num_luns. 1429 */ 1430 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1431 lun = scsilun_to_int(lunp); 1432 1433 if (lun > sdev->host->max_lun) { 1434 sdev_printk(KERN_WARNING, sdev, 1435 "lun%llu has a LUN larger than" 1436 " allowed by the host adapter\n", lun); 1437 } else { 1438 int res; 1439 1440 res = scsi_probe_and_add_lun(starget, 1441 lun, NULL, NULL, rescan, NULL); 1442 if (res == SCSI_SCAN_NO_RESPONSE) { 1443 /* 1444 * Got some results, but now none, abort. 1445 */ 1446 sdev_printk(KERN_ERR, sdev, 1447 "Unexpected response" 1448 " from lun %llu while scanning, scan" 1449 " aborted\n", (unsigned long long)lun); 1450 break; 1451 } 1452 } 1453 } 1454 1455 out_err: 1456 kfree(lun_data); 1457 out: 1458 if (scsi_device_created(sdev)) 1459 /* 1460 * the sdev we used didn't appear in the report luns scan 1461 */ 1462 __scsi_remove_device(sdev); 1463 scsi_device_put(sdev); 1464 return ret; 1465 } 1466 1467 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1468 uint id, u64 lun, void *hostdata) 1469 { 1470 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1471 struct device *parent = &shost->shost_gendev; 1472 struct scsi_target *starget; 1473 1474 if (strncmp(scsi_scan_type, "none", 4) == 0) 1475 return ERR_PTR(-ENODEV); 1476 1477 starget = scsi_alloc_target(parent, channel, id); 1478 if (!starget) 1479 return ERR_PTR(-ENOMEM); 1480 scsi_autopm_get_target(starget); 1481 1482 mutex_lock(&shost->scan_mutex); 1483 if (!shost->async_scan) 1484 scsi_complete_async_scans(); 1485 1486 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1487 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1488 scsi_autopm_put_host(shost); 1489 } 1490 mutex_unlock(&shost->scan_mutex); 1491 scsi_autopm_put_target(starget); 1492 /* 1493 * paired with scsi_alloc_target(). Target will be destroyed unless 1494 * scsi_probe_and_add_lun made an underlying device visible 1495 */ 1496 scsi_target_reap(starget); 1497 put_device(&starget->dev); 1498 1499 return sdev; 1500 } 1501 EXPORT_SYMBOL(__scsi_add_device); 1502 1503 int scsi_add_device(struct Scsi_Host *host, uint channel, 1504 uint target, u64 lun) 1505 { 1506 struct scsi_device *sdev = 1507 __scsi_add_device(host, channel, target, lun, NULL); 1508 if (IS_ERR(sdev)) 1509 return PTR_ERR(sdev); 1510 1511 scsi_device_put(sdev); 1512 return 0; 1513 } 1514 EXPORT_SYMBOL(scsi_add_device); 1515 1516 void scsi_rescan_device(struct device *dev) 1517 { 1518 struct scsi_device *sdev = to_scsi_device(dev); 1519 1520 device_lock(dev); 1521 1522 scsi_attach_vpd(sdev); 1523 1524 if (sdev->handler && sdev->handler->rescan) 1525 sdev->handler->rescan(sdev); 1526 1527 if (dev->driver && try_module_get(dev->driver->owner)) { 1528 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1529 1530 if (drv->rescan) 1531 drv->rescan(dev); 1532 module_put(dev->driver->owner); 1533 } 1534 device_unlock(dev); 1535 } 1536 EXPORT_SYMBOL(scsi_rescan_device); 1537 1538 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1539 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1540 { 1541 struct Scsi_Host *shost = dev_to_shost(parent); 1542 blist_flags_t bflags = 0; 1543 int res; 1544 struct scsi_target *starget; 1545 1546 if (shost->this_id == id) 1547 /* 1548 * Don't scan the host adapter 1549 */ 1550 return; 1551 1552 starget = scsi_alloc_target(parent, channel, id); 1553 if (!starget) 1554 return; 1555 scsi_autopm_get_target(starget); 1556 1557 if (lun != SCAN_WILD_CARD) { 1558 /* 1559 * Scan for a specific host/chan/id/lun. 1560 */ 1561 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1562 goto out_reap; 1563 } 1564 1565 /* 1566 * Scan LUN 0, if there is some response, scan further. Ideally, we 1567 * would not configure LUN 0 until all LUNs are scanned. 1568 */ 1569 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1570 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1571 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1572 /* 1573 * The REPORT LUN did not scan the target, 1574 * do a sequential scan. 1575 */ 1576 scsi_sequential_lun_scan(starget, bflags, 1577 starget->scsi_level, rescan); 1578 } 1579 1580 out_reap: 1581 scsi_autopm_put_target(starget); 1582 /* 1583 * paired with scsi_alloc_target(): determine if the target has 1584 * any children at all and if not, nuke it 1585 */ 1586 scsi_target_reap(starget); 1587 1588 put_device(&starget->dev); 1589 } 1590 1591 /** 1592 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1593 * @parent: host to scan 1594 * @channel: channel to scan 1595 * @id: target id to scan 1596 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1597 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1598 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1599 * and SCSI_SCAN_MANUAL to force scanning even if 1600 * 'scan=manual' is set. 1601 * 1602 * Description: 1603 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1604 * and possibly all LUNs on the target id. 1605 * 1606 * First try a REPORT LUN scan, if that does not scan the target, do a 1607 * sequential scan of LUNs on the target id. 1608 **/ 1609 void scsi_scan_target(struct device *parent, unsigned int channel, 1610 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1611 { 1612 struct Scsi_Host *shost = dev_to_shost(parent); 1613 1614 if (strncmp(scsi_scan_type, "none", 4) == 0) 1615 return; 1616 1617 if (rescan != SCSI_SCAN_MANUAL && 1618 strncmp(scsi_scan_type, "manual", 6) == 0) 1619 return; 1620 1621 mutex_lock(&shost->scan_mutex); 1622 if (!shost->async_scan) 1623 scsi_complete_async_scans(); 1624 1625 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1626 __scsi_scan_target(parent, channel, id, lun, rescan); 1627 scsi_autopm_put_host(shost); 1628 } 1629 mutex_unlock(&shost->scan_mutex); 1630 } 1631 EXPORT_SYMBOL(scsi_scan_target); 1632 1633 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1634 unsigned int id, u64 lun, 1635 enum scsi_scan_mode rescan) 1636 { 1637 uint order_id; 1638 1639 if (id == SCAN_WILD_CARD) 1640 for (id = 0; id < shost->max_id; ++id) { 1641 /* 1642 * XXX adapter drivers when possible (FCP, iSCSI) 1643 * could modify max_id to match the current max, 1644 * not the absolute max. 1645 * 1646 * XXX add a shost id iterator, so for example, 1647 * the FC ID can be the same as a target id 1648 * without a huge overhead of sparse id's. 1649 */ 1650 if (shost->reverse_ordering) 1651 /* 1652 * Scan from high to low id. 1653 */ 1654 order_id = shost->max_id - id - 1; 1655 else 1656 order_id = id; 1657 __scsi_scan_target(&shost->shost_gendev, channel, 1658 order_id, lun, rescan); 1659 } 1660 else 1661 __scsi_scan_target(&shost->shost_gendev, channel, 1662 id, lun, rescan); 1663 } 1664 1665 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1666 unsigned int id, u64 lun, 1667 enum scsi_scan_mode rescan) 1668 { 1669 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1670 "%s: <%u:%u:%llu>\n", 1671 __func__, channel, id, lun)); 1672 1673 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1674 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1675 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1676 return -EINVAL; 1677 1678 mutex_lock(&shost->scan_mutex); 1679 if (!shost->async_scan) 1680 scsi_complete_async_scans(); 1681 1682 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1683 if (channel == SCAN_WILD_CARD) 1684 for (channel = 0; channel <= shost->max_channel; 1685 channel++) 1686 scsi_scan_channel(shost, channel, id, lun, 1687 rescan); 1688 else 1689 scsi_scan_channel(shost, channel, id, lun, rescan); 1690 scsi_autopm_put_host(shost); 1691 } 1692 mutex_unlock(&shost->scan_mutex); 1693 1694 return 0; 1695 } 1696 1697 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1698 { 1699 struct scsi_device *sdev; 1700 shost_for_each_device(sdev, shost) { 1701 /* target removed before the device could be added */ 1702 if (sdev->sdev_state == SDEV_DEL) 1703 continue; 1704 /* If device is already visible, skip adding it to sysfs */ 1705 if (sdev->is_visible) 1706 continue; 1707 if (!scsi_host_scan_allowed(shost) || 1708 scsi_sysfs_add_sdev(sdev) != 0) 1709 __scsi_remove_device(sdev); 1710 } 1711 } 1712 1713 /** 1714 * scsi_prep_async_scan - prepare for an async scan 1715 * @shost: the host which will be scanned 1716 * Returns: a cookie to be passed to scsi_finish_async_scan() 1717 * 1718 * Tells the midlayer this host is going to do an asynchronous scan. 1719 * It reserves the host's position in the scanning list and ensures 1720 * that other asynchronous scans started after this one won't affect the 1721 * ordering of the discovered devices. 1722 */ 1723 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1724 { 1725 struct async_scan_data *data; 1726 unsigned long flags; 1727 1728 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1729 return NULL; 1730 1731 if (shost->async_scan) { 1732 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1733 return NULL; 1734 } 1735 1736 data = kmalloc(sizeof(*data), GFP_KERNEL); 1737 if (!data) 1738 goto err; 1739 data->shost = scsi_host_get(shost); 1740 if (!data->shost) 1741 goto err; 1742 init_completion(&data->prev_finished); 1743 1744 mutex_lock(&shost->scan_mutex); 1745 spin_lock_irqsave(shost->host_lock, flags); 1746 shost->async_scan = 1; 1747 spin_unlock_irqrestore(shost->host_lock, flags); 1748 mutex_unlock(&shost->scan_mutex); 1749 1750 spin_lock(&async_scan_lock); 1751 if (list_empty(&scanning_hosts)) 1752 complete(&data->prev_finished); 1753 list_add_tail(&data->list, &scanning_hosts); 1754 spin_unlock(&async_scan_lock); 1755 1756 return data; 1757 1758 err: 1759 kfree(data); 1760 return NULL; 1761 } 1762 1763 /** 1764 * scsi_finish_async_scan - asynchronous scan has finished 1765 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1766 * 1767 * All the devices currently attached to this host have been found. 1768 * This function announces all the devices it has found to the rest 1769 * of the system. 1770 */ 1771 static void scsi_finish_async_scan(struct async_scan_data *data) 1772 { 1773 struct Scsi_Host *shost; 1774 unsigned long flags; 1775 1776 if (!data) 1777 return; 1778 1779 shost = data->shost; 1780 1781 mutex_lock(&shost->scan_mutex); 1782 1783 if (!shost->async_scan) { 1784 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1785 dump_stack(); 1786 mutex_unlock(&shost->scan_mutex); 1787 return; 1788 } 1789 1790 wait_for_completion(&data->prev_finished); 1791 1792 scsi_sysfs_add_devices(shost); 1793 1794 spin_lock_irqsave(shost->host_lock, flags); 1795 shost->async_scan = 0; 1796 spin_unlock_irqrestore(shost->host_lock, flags); 1797 1798 mutex_unlock(&shost->scan_mutex); 1799 1800 spin_lock(&async_scan_lock); 1801 list_del(&data->list); 1802 if (!list_empty(&scanning_hosts)) { 1803 struct async_scan_data *next = list_entry(scanning_hosts.next, 1804 struct async_scan_data, list); 1805 complete(&next->prev_finished); 1806 } 1807 spin_unlock(&async_scan_lock); 1808 1809 scsi_autopm_put_host(shost); 1810 scsi_host_put(shost); 1811 kfree(data); 1812 } 1813 1814 static void do_scsi_scan_host(struct Scsi_Host *shost) 1815 { 1816 if (shost->hostt->scan_finished) { 1817 unsigned long start = jiffies; 1818 if (shost->hostt->scan_start) 1819 shost->hostt->scan_start(shost); 1820 1821 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1822 msleep(10); 1823 } else { 1824 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1825 SCAN_WILD_CARD, 0); 1826 } 1827 } 1828 1829 static void do_scan_async(void *_data, async_cookie_t c) 1830 { 1831 struct async_scan_data *data = _data; 1832 struct Scsi_Host *shost = data->shost; 1833 1834 do_scsi_scan_host(shost); 1835 scsi_finish_async_scan(data); 1836 } 1837 1838 /** 1839 * scsi_scan_host - scan the given adapter 1840 * @shost: adapter to scan 1841 **/ 1842 void scsi_scan_host(struct Scsi_Host *shost) 1843 { 1844 struct async_scan_data *data; 1845 1846 if (strncmp(scsi_scan_type, "none", 4) == 0 || 1847 strncmp(scsi_scan_type, "manual", 6) == 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