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_KERNEL); 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 sdev->request_queue = scsi_mq_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 scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ? 281 sdev->host->cmd_per_lun : 1); 282 283 scsi_sysfs_device_initialize(sdev); 284 285 if (shost->hostt->slave_alloc) { 286 ret = shost->hostt->slave_alloc(sdev); 287 if (ret) { 288 /* 289 * if LLDD reports slave not present, don't clutter 290 * console with alloc failure messages 291 */ 292 if (ret == -ENXIO) 293 display_failure_msg = 0; 294 goto out_device_destroy; 295 } 296 } 297 298 return sdev; 299 300 out_device_destroy: 301 __scsi_remove_device(sdev); 302 out: 303 if (display_failure_msg) 304 printk(ALLOC_FAILURE_MSG, __func__); 305 return NULL; 306 } 307 308 static void scsi_target_destroy(struct scsi_target *starget) 309 { 310 struct device *dev = &starget->dev; 311 struct Scsi_Host *shost = dev_to_shost(dev->parent); 312 unsigned long flags; 313 314 BUG_ON(starget->state == STARGET_DEL); 315 starget->state = STARGET_DEL; 316 transport_destroy_device(dev); 317 spin_lock_irqsave(shost->host_lock, flags); 318 if (shost->hostt->target_destroy) 319 shost->hostt->target_destroy(starget); 320 list_del_init(&starget->siblings); 321 spin_unlock_irqrestore(shost->host_lock, flags); 322 put_device(dev); 323 } 324 325 static void scsi_target_dev_release(struct device *dev) 326 { 327 struct device *parent = dev->parent; 328 struct scsi_target *starget = to_scsi_target(dev); 329 330 kfree(starget); 331 put_device(parent); 332 } 333 334 static struct device_type scsi_target_type = { 335 .name = "scsi_target", 336 .release = scsi_target_dev_release, 337 }; 338 339 int scsi_is_target_device(const struct device *dev) 340 { 341 return dev->type == &scsi_target_type; 342 } 343 EXPORT_SYMBOL(scsi_is_target_device); 344 345 static struct scsi_target *__scsi_find_target(struct device *parent, 346 int channel, uint id) 347 { 348 struct scsi_target *starget, *found_starget = NULL; 349 struct Scsi_Host *shost = dev_to_shost(parent); 350 /* 351 * Search for an existing target for this sdev. 352 */ 353 list_for_each_entry(starget, &shost->__targets, siblings) { 354 if (starget->id == id && 355 starget->channel == channel) { 356 found_starget = starget; 357 break; 358 } 359 } 360 if (found_starget) 361 get_device(&found_starget->dev); 362 363 return found_starget; 364 } 365 366 /** 367 * scsi_target_reap_ref_release - remove target from visibility 368 * @kref: the reap_ref in the target being released 369 * 370 * Called on last put of reap_ref, which is the indication that no device 371 * under this target is visible anymore, so render the target invisible in 372 * sysfs. Note: we have to be in user context here because the target reaps 373 * should be done in places where the scsi device visibility is being removed. 374 */ 375 static void scsi_target_reap_ref_release(struct kref *kref) 376 { 377 struct scsi_target *starget 378 = container_of(kref, struct scsi_target, reap_ref); 379 380 /* 381 * if we get here and the target is still in a CREATED state that 382 * means it was allocated but never made visible (because a scan 383 * turned up no LUNs), so don't call device_del() on it. 384 */ 385 if ((starget->state != STARGET_CREATED) && 386 (starget->state != STARGET_CREATED_REMOVE)) { 387 transport_remove_device(&starget->dev); 388 device_del(&starget->dev); 389 } 390 scsi_target_destroy(starget); 391 } 392 393 static void scsi_target_reap_ref_put(struct scsi_target *starget) 394 { 395 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 396 } 397 398 /** 399 * scsi_alloc_target - allocate a new or find an existing target 400 * @parent: parent of the target (need not be a scsi host) 401 * @channel: target channel number (zero if no channels) 402 * @id: target id number 403 * 404 * Return an existing target if one exists, provided it hasn't already 405 * gone into STARGET_DEL state, otherwise allocate a new target. 406 * 407 * The target is returned with an incremented reference, so the caller 408 * is responsible for both reaping and doing a last put 409 */ 410 static struct scsi_target *scsi_alloc_target(struct device *parent, 411 int channel, uint id) 412 { 413 struct Scsi_Host *shost = dev_to_shost(parent); 414 struct device *dev = NULL; 415 unsigned long flags; 416 const int size = sizeof(struct scsi_target) 417 + shost->transportt->target_size; 418 struct scsi_target *starget; 419 struct scsi_target *found_target; 420 int error, ref_got; 421 422 starget = kzalloc(size, GFP_KERNEL); 423 if (!starget) { 424 printk(KERN_ERR "%s: allocation failure\n", __func__); 425 return NULL; 426 } 427 dev = &starget->dev; 428 device_initialize(dev); 429 kref_init(&starget->reap_ref); 430 dev->parent = get_device(parent); 431 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 432 dev->bus = &scsi_bus_type; 433 dev->type = &scsi_target_type; 434 starget->id = id; 435 starget->channel = channel; 436 starget->can_queue = 0; 437 INIT_LIST_HEAD(&starget->siblings); 438 INIT_LIST_HEAD(&starget->devices); 439 starget->state = STARGET_CREATED; 440 starget->scsi_level = SCSI_2; 441 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 442 retry: 443 spin_lock_irqsave(shost->host_lock, flags); 444 445 found_target = __scsi_find_target(parent, channel, id); 446 if (found_target) 447 goto found; 448 449 list_add_tail(&starget->siblings, &shost->__targets); 450 spin_unlock_irqrestore(shost->host_lock, flags); 451 /* allocate and add */ 452 transport_setup_device(dev); 453 if (shost->hostt->target_alloc) { 454 error = shost->hostt->target_alloc(starget); 455 456 if(error) { 457 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 458 /* don't want scsi_target_reap to do the final 459 * put because it will be under the host lock */ 460 scsi_target_destroy(starget); 461 return NULL; 462 } 463 } 464 get_device(dev); 465 466 return starget; 467 468 found: 469 /* 470 * release routine already fired if kref is zero, so if we can still 471 * take the reference, the target must be alive. If we can't, it must 472 * be dying and we need to wait for a new target 473 */ 474 ref_got = kref_get_unless_zero(&found_target->reap_ref); 475 476 spin_unlock_irqrestore(shost->host_lock, flags); 477 if (ref_got) { 478 put_device(dev); 479 return found_target; 480 } 481 /* 482 * Unfortunately, we found a dying target; need to wait until it's 483 * dead before we can get a new one. There is an anomaly here. We 484 * *should* call scsi_target_reap() to balance the kref_get() of the 485 * reap_ref above. However, since the target being released, it's 486 * already invisible and the reap_ref is irrelevant. If we call 487 * scsi_target_reap() we might spuriously do another device_del() on 488 * an already invisible target. 489 */ 490 put_device(&found_target->dev); 491 /* 492 * length of time is irrelevant here, we just want to yield the CPU 493 * for a tick to avoid busy waiting for the target to die. 494 */ 495 msleep(1); 496 goto retry; 497 } 498 499 /** 500 * scsi_target_reap - check to see if target is in use and destroy if not 501 * @starget: target to be checked 502 * 503 * This is used after removing a LUN or doing a last put of the target 504 * it checks atomically that nothing is using the target and removes 505 * it if so. 506 */ 507 void scsi_target_reap(struct scsi_target *starget) 508 { 509 /* 510 * serious problem if this triggers: STARGET_DEL is only set in the if 511 * the reap_ref drops to zero, so we're trying to do another final put 512 * on an already released kref 513 */ 514 BUG_ON(starget->state == STARGET_DEL); 515 scsi_target_reap_ref_put(starget); 516 } 517 518 /** 519 * scsi_sanitize_inquiry_string - remove non-graphical chars from an 520 * INQUIRY result string 521 * @s: INQUIRY result string to sanitize 522 * @len: length of the string 523 * 524 * Description: 525 * The SCSI spec says that INQUIRY vendor, product, and revision 526 * strings must consist entirely of graphic ASCII characters, 527 * padded on the right with spaces. Since not all devices obey 528 * this rule, we will replace non-graphic or non-ASCII characters 529 * with spaces. Exception: a NUL character is interpreted as a 530 * string terminator, so all the following characters are set to 531 * spaces. 532 **/ 533 void scsi_sanitize_inquiry_string(unsigned char *s, int len) 534 { 535 int terminated = 0; 536 537 for (; len > 0; (--len, ++s)) { 538 if (*s == 0) 539 terminated = 1; 540 if (terminated || *s < 0x20 || *s > 0x7e) 541 *s = ' '; 542 } 543 } 544 EXPORT_SYMBOL(scsi_sanitize_inquiry_string); 545 546 /** 547 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 548 * @sdev: scsi_device to probe 549 * @inq_result: area to store the INQUIRY result 550 * @result_len: len of inq_result 551 * @bflags: store any bflags found here 552 * 553 * Description: 554 * Probe the lun associated with @req using a standard SCSI INQUIRY; 555 * 556 * If the INQUIRY is successful, zero is returned and the 557 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 558 * are copied to the scsi_device any flags value is stored in *@bflags. 559 **/ 560 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 561 int result_len, blist_flags_t *bflags) 562 { 563 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 564 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 565 int response_len = 0; 566 int pass, count, result; 567 struct scsi_sense_hdr sshdr; 568 569 *bflags = 0; 570 571 /* Perform up to 3 passes. The first pass uses a conservative 572 * transfer length of 36 unless sdev->inquiry_len specifies a 573 * different value. */ 574 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 575 try_inquiry_len = first_inquiry_len; 576 pass = 1; 577 578 next_pass: 579 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 580 "scsi scan: INQUIRY pass %d length %d\n", 581 pass, try_inquiry_len)); 582 583 /* Each pass gets up to three chances to ignore Unit Attention */ 584 for (count = 0; count < 3; ++count) { 585 int resid; 586 587 memset(scsi_cmd, 0, 6); 588 scsi_cmd[0] = INQUIRY; 589 scsi_cmd[4] = (unsigned char) try_inquiry_len; 590 591 memset(inq_result, 0, try_inquiry_len); 592 593 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 594 inq_result, try_inquiry_len, &sshdr, 595 HZ / 2 + HZ * scsi_inq_timeout, 3, 596 &resid); 597 598 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 599 "scsi scan: INQUIRY %s with code 0x%x\n", 600 result ? "failed" : "successful", result)); 601 602 if (result) { 603 /* 604 * not-ready to ready transition [asc/ascq=0x28/0x0] 605 * or power-on, reset [asc/ascq=0x29/0x0], continue. 606 * INQUIRY should not yield UNIT_ATTENTION 607 * but many buggy devices do so anyway. 608 */ 609 if (driver_byte(result) == DRIVER_SENSE && 610 scsi_sense_valid(&sshdr)) { 611 if ((sshdr.sense_key == UNIT_ATTENTION) && 612 ((sshdr.asc == 0x28) || 613 (sshdr.asc == 0x29)) && 614 (sshdr.ascq == 0)) 615 continue; 616 } 617 } else { 618 /* 619 * if nothing was transferred, we try 620 * again. It's a workaround for some USB 621 * devices. 622 */ 623 if (resid == try_inquiry_len) 624 continue; 625 } 626 break; 627 } 628 629 if (result == 0) { 630 scsi_sanitize_inquiry_string(&inq_result[8], 8); 631 scsi_sanitize_inquiry_string(&inq_result[16], 16); 632 scsi_sanitize_inquiry_string(&inq_result[32], 4); 633 634 response_len = inq_result[4] + 5; 635 if (response_len > 255) 636 response_len = first_inquiry_len; /* sanity */ 637 638 /* 639 * Get any flags for this device. 640 * 641 * XXX add a bflags to scsi_device, and replace the 642 * corresponding bit fields in scsi_device, so bflags 643 * need not be passed as an argument. 644 */ 645 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 646 &inq_result[16]); 647 648 /* When the first pass succeeds we gain information about 649 * what larger transfer lengths might work. */ 650 if (pass == 1) { 651 if (BLIST_INQUIRY_36 & *bflags) 652 next_inquiry_len = 36; 653 else if (sdev->inquiry_len) 654 next_inquiry_len = sdev->inquiry_len; 655 else 656 next_inquiry_len = response_len; 657 658 /* If more data is available perform the second pass */ 659 if (next_inquiry_len > try_inquiry_len) { 660 try_inquiry_len = next_inquiry_len; 661 pass = 2; 662 goto next_pass; 663 } 664 } 665 666 } else if (pass == 2) { 667 sdev_printk(KERN_INFO, sdev, 668 "scsi scan: %d byte inquiry failed. " 669 "Consider BLIST_INQUIRY_36 for this device\n", 670 try_inquiry_len); 671 672 /* If this pass failed, the third pass goes back and transfers 673 * the same amount as we successfully got in the first pass. */ 674 try_inquiry_len = first_inquiry_len; 675 pass = 3; 676 goto next_pass; 677 } 678 679 /* If the last transfer attempt got an error, assume the 680 * peripheral doesn't exist or is dead. */ 681 if (result) 682 return -EIO; 683 684 /* Don't report any more data than the device says is valid */ 685 sdev->inquiry_len = min(try_inquiry_len, response_len); 686 687 /* 688 * XXX Abort if the response length is less than 36? If less than 689 * 32, the lookup of the device flags (above) could be invalid, 690 * and it would be possible to take an incorrect action - we do 691 * not want to hang because of a short INQUIRY. On the flip side, 692 * if the device is spun down or becoming ready (and so it gives a 693 * short INQUIRY), an abort here prevents any further use of the 694 * device, including spin up. 695 * 696 * On the whole, the best approach seems to be to assume the first 697 * 36 bytes are valid no matter what the device says. That's 698 * better than copying < 36 bytes to the inquiry-result buffer 699 * and displaying garbage for the Vendor, Product, or Revision 700 * strings. 701 */ 702 if (sdev->inquiry_len < 36) { 703 if (!sdev->host->short_inquiry) { 704 shost_printk(KERN_INFO, sdev->host, 705 "scsi scan: INQUIRY result too short (%d)," 706 " using 36\n", sdev->inquiry_len); 707 sdev->host->short_inquiry = 1; 708 } 709 sdev->inquiry_len = 36; 710 } 711 712 /* 713 * Related to the above issue: 714 * 715 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 716 * and if not ready, sent a START_STOP to start (maybe spin up) and 717 * then send the INQUIRY again, since the INQUIRY can change after 718 * a device is initialized. 719 * 720 * Ideally, start a device if explicitly asked to do so. This 721 * assumes that a device is spun up on power on, spun down on 722 * request, and then spun up on request. 723 */ 724 725 /* 726 * The scanning code needs to know the scsi_level, even if no 727 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 728 * non-zero LUNs can be scanned. 729 */ 730 sdev->scsi_level = inq_result[2] & 0x07; 731 if (sdev->scsi_level >= 2 || 732 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 733 sdev->scsi_level++; 734 sdev->sdev_target->scsi_level = sdev->scsi_level; 735 736 /* 737 * If SCSI-2 or lower, and if the transport requires it, 738 * store the LUN value in CDB[1]. 739 */ 740 sdev->lun_in_cdb = 0; 741 if (sdev->scsi_level <= SCSI_2 && 742 sdev->scsi_level != SCSI_UNKNOWN && 743 !sdev->host->no_scsi2_lun_in_cdb) 744 sdev->lun_in_cdb = 1; 745 746 return 0; 747 } 748 749 /** 750 * scsi_add_lun - allocate and fully initialze a scsi_device 751 * @sdev: holds information to be stored in the new scsi_device 752 * @inq_result: holds the result of a previous INQUIRY to the LUN 753 * @bflags: black/white list flag 754 * @async: 1 if this device is being scanned asynchronously 755 * 756 * Description: 757 * Initialize the scsi_device @sdev. Optionally set fields based 758 * on values in *@bflags. 759 * 760 * Return: 761 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 762 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 763 **/ 764 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 765 blist_flags_t *bflags, int async) 766 { 767 int ret; 768 769 /* 770 * XXX do not save the inquiry, since it can change underneath us, 771 * save just vendor/model/rev. 772 * 773 * Rather than save it and have an ioctl that retrieves the saved 774 * value, have an ioctl that executes the same INQUIRY code used 775 * in scsi_probe_lun, let user level programs doing INQUIRY 776 * scanning run at their own risk, or supply a user level program 777 * that can correctly scan. 778 */ 779 780 /* 781 * Copy at least 36 bytes of INQUIRY data, so that we don't 782 * dereference unallocated memory when accessing the Vendor, 783 * Product, and Revision strings. Badly behaved devices may set 784 * the INQUIRY Additional Length byte to a small value, indicating 785 * these strings are invalid, but often they contain plausible data 786 * nonetheless. It doesn't matter if the device sent < 36 bytes 787 * total, since scsi_probe_lun() initializes inq_result with 0s. 788 */ 789 sdev->inquiry = kmemdup(inq_result, 790 max_t(size_t, sdev->inquiry_len, 36), 791 GFP_KERNEL); 792 if (sdev->inquiry == NULL) 793 return SCSI_SCAN_NO_RESPONSE; 794 795 sdev->vendor = (char *) (sdev->inquiry + 8); 796 sdev->model = (char *) (sdev->inquiry + 16); 797 sdev->rev = (char *) (sdev->inquiry + 32); 798 799 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 800 /* 801 * sata emulation layer device. This is a hack to work around 802 * the SATL power management specifications which state that 803 * when the SATL detects the device has gone into standby 804 * mode, it shall respond with NOT READY. 805 */ 806 sdev->allow_restart = 1; 807 } 808 809 if (*bflags & BLIST_ISROM) { 810 sdev->type = TYPE_ROM; 811 sdev->removable = 1; 812 } else { 813 sdev->type = (inq_result[0] & 0x1f); 814 sdev->removable = (inq_result[1] & 0x80) >> 7; 815 816 /* 817 * some devices may respond with wrong type for 818 * well-known logical units. Force well-known type 819 * to enumerate them correctly. 820 */ 821 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) { 822 sdev_printk(KERN_WARNING, sdev, 823 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n", 824 __func__, sdev->type, (unsigned int)sdev->lun); 825 sdev->type = TYPE_WLUN; 826 } 827 828 } 829 830 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 831 /* RBC and MMC devices can return SCSI-3 compliance and yet 832 * still not support REPORT LUNS, so make them act as 833 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 834 * specifically set */ 835 if ((*bflags & BLIST_REPORTLUN2) == 0) 836 *bflags |= BLIST_NOREPORTLUN; 837 } 838 839 /* 840 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 841 * spec says: The device server is capable of supporting the 842 * specified peripheral device type on this logical unit. However, 843 * the physical device is not currently connected to this logical 844 * unit. 845 * 846 * The above is vague, as it implies that we could treat 001 and 847 * 011 the same. Stay compatible with previous code, and create a 848 * scsi_device for a PQ of 1 849 * 850 * Don't set the device offline here; rather let the upper 851 * level drivers eval the PQ to decide whether they should 852 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 853 */ 854 855 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 856 sdev->lockable = sdev->removable; 857 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 858 859 if (sdev->scsi_level >= SCSI_3 || 860 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 861 sdev->ppr = 1; 862 if (inq_result[7] & 0x60) 863 sdev->wdtr = 1; 864 if (inq_result[7] & 0x10) 865 sdev->sdtr = 1; 866 867 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 868 "ANSI: %d%s\n", scsi_device_type(sdev->type), 869 sdev->vendor, sdev->model, sdev->rev, 870 sdev->inq_periph_qual, inq_result[2] & 0x07, 871 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 872 873 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 874 !(*bflags & BLIST_NOTQ)) { 875 sdev->tagged_supported = 1; 876 sdev->simple_tags = 1; 877 } 878 879 /* 880 * Some devices (Texel CD ROM drives) have handshaking problems 881 * when used with the Seagate controllers. borken is initialized 882 * to 1, and then set it to 0 here. 883 */ 884 if ((*bflags & BLIST_BORKEN) == 0) 885 sdev->borken = 0; 886 887 if (*bflags & BLIST_NO_ULD_ATTACH) 888 sdev->no_uld_attach = 1; 889 890 /* 891 * Apparently some really broken devices (contrary to the SCSI 892 * standards) need to be selected without asserting ATN 893 */ 894 if (*bflags & BLIST_SELECT_NO_ATN) 895 sdev->select_no_atn = 1; 896 897 /* 898 * Maximum 512 sector transfer length 899 * broken RA4x00 Compaq Disk Array 900 */ 901 if (*bflags & BLIST_MAX_512) 902 blk_queue_max_hw_sectors(sdev->request_queue, 512); 903 /* 904 * Max 1024 sector transfer length for targets that report incorrect 905 * max/optimal lengths and relied on the old block layer safe default 906 */ 907 else if (*bflags & BLIST_MAX_1024) 908 blk_queue_max_hw_sectors(sdev->request_queue, 1024); 909 910 /* 911 * Some devices may not want to have a start command automatically 912 * issued when a device is added. 913 */ 914 if (*bflags & BLIST_NOSTARTONADD) 915 sdev->no_start_on_add = 1; 916 917 if (*bflags & BLIST_SINGLELUN) 918 scsi_target(sdev)->single_lun = 1; 919 920 sdev->use_10_for_rw = 1; 921 922 /* some devices don't like REPORT SUPPORTED OPERATION CODES 923 * and will simply timeout causing sd_mod init to take a very 924 * very long time */ 925 if (*bflags & BLIST_NO_RSOC) 926 sdev->no_report_opcodes = 1; 927 928 /* set the device running here so that slave configure 929 * may do I/O */ 930 mutex_lock(&sdev->state_mutex); 931 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 932 if (ret) 933 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 934 mutex_unlock(&sdev->state_mutex); 935 936 if (ret) { 937 sdev_printk(KERN_ERR, sdev, 938 "in wrong state %s to complete scan\n", 939 scsi_device_state_name(sdev->sdev_state)); 940 return SCSI_SCAN_NO_RESPONSE; 941 } 942 943 if (*bflags & BLIST_NOT_LOCKABLE) 944 sdev->lockable = 0; 945 946 if (*bflags & BLIST_RETRY_HWERROR) 947 sdev->retry_hwerror = 1; 948 949 if (*bflags & BLIST_NO_DIF) 950 sdev->no_dif = 1; 951 952 if (*bflags & BLIST_UNMAP_LIMIT_WS) 953 sdev->unmap_limit_for_ws = 1; 954 955 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 956 957 if (*bflags & BLIST_TRY_VPD_PAGES) 958 sdev->try_vpd_pages = 1; 959 else if (*bflags & BLIST_SKIP_VPD_PAGES) 960 sdev->skip_vpd_pages = 1; 961 962 transport_configure_device(&sdev->sdev_gendev); 963 964 if (sdev->host->hostt->slave_configure) { 965 ret = sdev->host->hostt->slave_configure(sdev); 966 if (ret) { 967 /* 968 * if LLDD reports slave not present, don't clutter 969 * console with alloc failure messages 970 */ 971 if (ret != -ENXIO) { 972 sdev_printk(KERN_ERR, sdev, 973 "failed to configure device\n"); 974 } 975 return SCSI_SCAN_NO_RESPONSE; 976 } 977 } 978 979 if (sdev->scsi_level >= SCSI_3) 980 scsi_attach_vpd(sdev); 981 982 sdev->max_queue_depth = sdev->queue_depth; 983 sdev->sdev_bflags = *bflags; 984 985 /* 986 * Ok, the device is now all set up, we can 987 * register it and tell the rest of the kernel 988 * about it. 989 */ 990 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 991 return SCSI_SCAN_NO_RESPONSE; 992 993 return SCSI_SCAN_LUN_PRESENT; 994 } 995 996 #ifdef CONFIG_SCSI_LOGGING 997 /** 998 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 999 * @buf: Output buffer with at least end-first+1 bytes of space 1000 * @inq: Inquiry buffer (input) 1001 * @first: Offset of string into inq 1002 * @end: Index after last character in inq 1003 */ 1004 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 1005 unsigned first, unsigned end) 1006 { 1007 unsigned term = 0, idx; 1008 1009 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1010 if (inq[idx+first] > ' ') { 1011 buf[idx] = inq[idx+first]; 1012 term = idx+1; 1013 } else { 1014 buf[idx] = ' '; 1015 } 1016 } 1017 buf[term] = 0; 1018 return buf; 1019 } 1020 #endif 1021 1022 /** 1023 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1024 * @starget: pointer to target device structure 1025 * @lun: LUN of target device 1026 * @bflagsp: store bflags here if not NULL 1027 * @sdevp: probe the LUN corresponding to this scsi_device 1028 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only 1029 * needed on first scan 1030 * @hostdata: passed to scsi_alloc_sdev() 1031 * 1032 * Description: 1033 * Call scsi_probe_lun, if a LUN with an attached device is found, 1034 * allocate and set it up by calling scsi_add_lun. 1035 * 1036 * Return: 1037 * 1038 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1039 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1040 * attached at the LUN 1041 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1042 **/ 1043 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1044 u64 lun, blist_flags_t *bflagsp, 1045 struct scsi_device **sdevp, 1046 enum scsi_scan_mode rescan, 1047 void *hostdata) 1048 { 1049 struct scsi_device *sdev; 1050 unsigned char *result; 1051 blist_flags_t bflags; 1052 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1053 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1054 1055 /* 1056 * The rescan flag is used as an optimization, the first scan of a 1057 * host adapter calls into here with rescan == 0. 1058 */ 1059 sdev = scsi_device_lookup_by_target(starget, lun); 1060 if (sdev) { 1061 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) { 1062 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1063 "scsi scan: device exists on %s\n", 1064 dev_name(&sdev->sdev_gendev))); 1065 if (sdevp) 1066 *sdevp = sdev; 1067 else 1068 scsi_device_put(sdev); 1069 1070 if (bflagsp) 1071 *bflagsp = scsi_get_device_flags(sdev, 1072 sdev->vendor, 1073 sdev->model); 1074 return SCSI_SCAN_LUN_PRESENT; 1075 } 1076 scsi_device_put(sdev); 1077 } else 1078 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1079 if (!sdev) 1080 goto out; 1081 1082 result = kmalloc(result_len, GFP_KERNEL | 1083 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1084 if (!result) 1085 goto out_free_sdev; 1086 1087 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1088 goto out_free_result; 1089 1090 if (bflagsp) 1091 *bflagsp = bflags; 1092 /* 1093 * result contains valid SCSI INQUIRY data. 1094 */ 1095 if ((result[0] >> 5) == 3) { 1096 /* 1097 * For a Peripheral qualifier 3 (011b), the SCSI 1098 * spec says: The device server is not capable of 1099 * supporting a physical device on this logical 1100 * unit. 1101 * 1102 * For disks, this implies that there is no 1103 * logical disk configured at sdev->lun, but there 1104 * is a target id responding. 1105 */ 1106 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1107 " peripheral qualifier of 3, device not" 1108 " added\n")) 1109 if (lun == 0) { 1110 SCSI_LOG_SCAN_BUS(1, { 1111 unsigned char vend[9]; 1112 unsigned char mod[17]; 1113 1114 sdev_printk(KERN_INFO, sdev, 1115 "scsi scan: consider passing scsi_mod." 1116 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1117 scsi_inq_str(vend, result, 8, 16), 1118 scsi_inq_str(mod, result, 16, 32)); 1119 }); 1120 1121 } 1122 1123 res = SCSI_SCAN_TARGET_PRESENT; 1124 goto out_free_result; 1125 } 1126 1127 /* 1128 * Some targets may set slight variations of PQ and PDT to signal 1129 * that no LUN is present, so don't add sdev in these cases. 1130 * Two specific examples are: 1131 * 1) NetApp targets: return PQ=1, PDT=0x1f 1132 * 2) IBM/2145 targets: return PQ=1, PDT=0 1133 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1134 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1135 * 1136 * References: 1137 * 1) SCSI SPC-3, pp. 145-146 1138 * PQ=1: "A peripheral device having the specified peripheral 1139 * device type is not connected to this logical unit. However, the 1140 * device server is capable of supporting the specified peripheral 1141 * device type on this logical unit." 1142 * PDT=0x1f: "Unknown or no device type" 1143 * 2) USB UFI 1.0, p. 20 1144 * PDT=00h Direct-access device (floppy) 1145 * PDT=1Fh none (no FDD connected to the requested logical unit) 1146 */ 1147 if (((result[0] >> 5) == 1 || 1148 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) && 1149 !scsi_is_wlun(lun)) { 1150 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 1151 "scsi scan: peripheral device type" 1152 " of 31, no device added\n")); 1153 res = SCSI_SCAN_TARGET_PRESENT; 1154 goto out_free_result; 1155 } 1156 1157 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1158 if (res == SCSI_SCAN_LUN_PRESENT) { 1159 if (bflags & BLIST_KEY) { 1160 sdev->lockable = 0; 1161 scsi_unlock_floptical(sdev, result); 1162 } 1163 } 1164 1165 out_free_result: 1166 kfree(result); 1167 out_free_sdev: 1168 if (res == SCSI_SCAN_LUN_PRESENT) { 1169 if (sdevp) { 1170 if (scsi_device_get(sdev) == 0) { 1171 *sdevp = sdev; 1172 } else { 1173 __scsi_remove_device(sdev); 1174 res = SCSI_SCAN_NO_RESPONSE; 1175 } 1176 } 1177 } else 1178 __scsi_remove_device(sdev); 1179 out: 1180 return res; 1181 } 1182 1183 /** 1184 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1185 * @starget: pointer to target structure to scan 1186 * @bflags: black/white list flag for LUN 0 1187 * @scsi_level: Which version of the standard does this device adhere to 1188 * @rescan: passed to scsi_probe_add_lun() 1189 * 1190 * Description: 1191 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1192 * scanned) to some maximum lun until a LUN is found with no device 1193 * attached. Use the bflags to figure out any oddities. 1194 * 1195 * Modifies sdevscan->lun. 1196 **/ 1197 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1198 blist_flags_t bflags, int scsi_level, 1199 enum scsi_scan_mode rescan) 1200 { 1201 uint max_dev_lun; 1202 u64 sparse_lun, lun; 1203 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1204 1205 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget, 1206 "scsi scan: Sequential scan\n")); 1207 1208 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1209 /* 1210 * If this device is known to support sparse multiple units, 1211 * override the other settings, and scan all of them. Normally, 1212 * SCSI-3 devices should be scanned via the REPORT LUNS. 1213 */ 1214 if (bflags & BLIST_SPARSELUN) { 1215 max_dev_lun = shost->max_lun; 1216 sparse_lun = 1; 1217 } else 1218 sparse_lun = 0; 1219 1220 /* 1221 * If less than SCSI_1_CCS, and no special lun scanning, stop 1222 * scanning; this matches 2.4 behaviour, but could just be a bug 1223 * (to continue scanning a SCSI_1_CCS device). 1224 * 1225 * This test is broken. We might not have any device on lun0 for 1226 * a sparselun device, and if that's the case then how would we 1227 * know the real scsi_level, eh? It might make sense to just not 1228 * scan any SCSI_1 device for non-0 luns, but that check would best 1229 * go into scsi_alloc_sdev() and just have it return null when asked 1230 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1231 * 1232 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1233 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1234 == 0)) 1235 return; 1236 */ 1237 /* 1238 * If this device is known to support multiple units, override 1239 * the other settings, and scan all of them. 1240 */ 1241 if (bflags & BLIST_FORCELUN) 1242 max_dev_lun = shost->max_lun; 1243 /* 1244 * REGAL CDC-4X: avoid hang after LUN 4 1245 */ 1246 if (bflags & BLIST_MAX5LUN) 1247 max_dev_lun = min(5U, max_dev_lun); 1248 /* 1249 * Do not scan SCSI-2 or lower device past LUN 7, unless 1250 * BLIST_LARGELUN. 1251 */ 1252 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1253 max_dev_lun = min(8U, max_dev_lun); 1254 else 1255 max_dev_lun = min(256U, max_dev_lun); 1256 1257 /* 1258 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1259 * until we reach the max, or no LUN is found and we are not 1260 * sparse_lun. 1261 */ 1262 for (lun = 1; lun < max_dev_lun; ++lun) 1263 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1264 NULL) != SCSI_SCAN_LUN_PRESENT) && 1265 !sparse_lun) 1266 return; 1267 } 1268 1269 /** 1270 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1271 * @starget: which target 1272 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1273 * @rescan: nonzero if we can skip code only needed on first scan 1274 * 1275 * Description: 1276 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1277 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1278 * 1279 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1280 * LUNs even if it's older than SCSI-3. 1281 * If BLIST_NOREPORTLUN is set, return 1 always. 1282 * If BLIST_NOLUN is set, return 0 always. 1283 * If starget->no_report_luns is set, return 1 always. 1284 * 1285 * Return: 1286 * 0: scan completed (or no memory, so further scanning is futile) 1287 * 1: could not scan with REPORT LUN 1288 **/ 1289 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags, 1290 enum scsi_scan_mode rescan) 1291 { 1292 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1293 unsigned int length; 1294 u64 lun; 1295 unsigned int num_luns; 1296 unsigned int retries; 1297 int result; 1298 struct scsi_lun *lunp, *lun_data; 1299 struct scsi_sense_hdr sshdr; 1300 struct scsi_device *sdev; 1301 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1302 int ret = 0; 1303 1304 /* 1305 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1306 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1307 * support more than 8 LUNs. 1308 * Don't attempt if the target doesn't support REPORT LUNS. 1309 */ 1310 if (bflags & BLIST_NOREPORTLUN) 1311 return 1; 1312 if (starget->scsi_level < SCSI_2 && 1313 starget->scsi_level != SCSI_UNKNOWN) 1314 return 1; 1315 if (starget->scsi_level < SCSI_3 && 1316 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1317 return 1; 1318 if (bflags & BLIST_NOLUN) 1319 return 0; 1320 if (starget->no_report_luns) 1321 return 1; 1322 1323 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1324 sdev = scsi_alloc_sdev(starget, 0, NULL); 1325 if (!sdev) 1326 return 0; 1327 if (scsi_device_get(sdev)) { 1328 __scsi_remove_device(sdev); 1329 return 0; 1330 } 1331 } 1332 1333 /* 1334 * Allocate enough to hold the header (the same size as one scsi_lun) 1335 * plus the number of luns we are requesting. 511 was the default 1336 * value of the now removed max_report_luns parameter. 1337 */ 1338 length = (511 + 1) * sizeof(struct scsi_lun); 1339 retry: 1340 lun_data = kmalloc(length, GFP_KERNEL | 1341 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1342 if (!lun_data) { 1343 printk(ALLOC_FAILURE_MSG, __func__); 1344 goto out; 1345 } 1346 1347 scsi_cmd[0] = REPORT_LUNS; 1348 1349 /* 1350 * bytes 1 - 5: reserved, set to zero. 1351 */ 1352 memset(&scsi_cmd[1], 0, 5); 1353 1354 /* 1355 * bytes 6 - 9: length of the command. 1356 */ 1357 put_unaligned_be32(length, &scsi_cmd[6]); 1358 1359 scsi_cmd[10] = 0; /* reserved */ 1360 scsi_cmd[11] = 0; /* control */ 1361 1362 /* 1363 * We can get a UNIT ATTENTION, for example a power on/reset, so 1364 * retry a few times (like sd.c does for TEST UNIT READY). 1365 * Experience shows some combinations of adapter/devices get at 1366 * least two power on/resets. 1367 * 1368 * Illegal requests (for devices that do not support REPORT LUNS) 1369 * should come through as a check condition, and will not generate 1370 * a retry. 1371 */ 1372 for (retries = 0; retries < 3; retries++) { 1373 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1374 "scsi scan: Sending REPORT LUNS to (try %d)\n", 1375 retries)); 1376 1377 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1378 lun_data, length, &sshdr, 1379 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL); 1380 1381 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1382 "scsi scan: REPORT LUNS" 1383 " %s (try %d) result 0x%x\n", 1384 result ? "failed" : "successful", 1385 retries, result)); 1386 if (result == 0) 1387 break; 1388 else if (scsi_sense_valid(&sshdr)) { 1389 if (sshdr.sense_key != UNIT_ATTENTION) 1390 break; 1391 } 1392 } 1393 1394 if (result) { 1395 /* 1396 * The device probably does not support a REPORT LUN command 1397 */ 1398 ret = 1; 1399 goto out_err; 1400 } 1401 1402 /* 1403 * Get the length from the first four bytes of lun_data. 1404 */ 1405 if (get_unaligned_be32(lun_data->scsi_lun) + 1406 sizeof(struct scsi_lun) > length) { 1407 length = get_unaligned_be32(lun_data->scsi_lun) + 1408 sizeof(struct scsi_lun); 1409 kfree(lun_data); 1410 goto retry; 1411 } 1412 length = get_unaligned_be32(lun_data->scsi_lun); 1413 1414 num_luns = (length / sizeof(struct scsi_lun)); 1415 1416 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1417 "scsi scan: REPORT LUN scan\n")); 1418 1419 /* 1420 * Scan the luns in lun_data. The entry at offset 0 is really 1421 * the header, so start at 1 and go up to and including num_luns. 1422 */ 1423 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1424 lun = scsilun_to_int(lunp); 1425 1426 if (lun > sdev->host->max_lun) { 1427 sdev_printk(KERN_WARNING, sdev, 1428 "lun%llu has a LUN larger than" 1429 " allowed by the host adapter\n", lun); 1430 } else { 1431 int res; 1432 1433 res = scsi_probe_and_add_lun(starget, 1434 lun, NULL, NULL, rescan, NULL); 1435 if (res == SCSI_SCAN_NO_RESPONSE) { 1436 /* 1437 * Got some results, but now none, abort. 1438 */ 1439 sdev_printk(KERN_ERR, sdev, 1440 "Unexpected response" 1441 " from lun %llu while scanning, scan" 1442 " aborted\n", (unsigned long long)lun); 1443 break; 1444 } 1445 } 1446 } 1447 1448 out_err: 1449 kfree(lun_data); 1450 out: 1451 if (scsi_device_created(sdev)) 1452 /* 1453 * the sdev we used didn't appear in the report luns scan 1454 */ 1455 __scsi_remove_device(sdev); 1456 scsi_device_put(sdev); 1457 return ret; 1458 } 1459 1460 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1461 uint id, u64 lun, void *hostdata) 1462 { 1463 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1464 struct device *parent = &shost->shost_gendev; 1465 struct scsi_target *starget; 1466 1467 if (strncmp(scsi_scan_type, "none", 4) == 0) 1468 return ERR_PTR(-ENODEV); 1469 1470 starget = scsi_alloc_target(parent, channel, id); 1471 if (!starget) 1472 return ERR_PTR(-ENOMEM); 1473 scsi_autopm_get_target(starget); 1474 1475 mutex_lock(&shost->scan_mutex); 1476 if (!shost->async_scan) 1477 scsi_complete_async_scans(); 1478 1479 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1480 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1481 scsi_autopm_put_host(shost); 1482 } 1483 mutex_unlock(&shost->scan_mutex); 1484 scsi_autopm_put_target(starget); 1485 /* 1486 * paired with scsi_alloc_target(). Target will be destroyed unless 1487 * scsi_probe_and_add_lun made an underlying device visible 1488 */ 1489 scsi_target_reap(starget); 1490 put_device(&starget->dev); 1491 1492 return sdev; 1493 } 1494 EXPORT_SYMBOL(__scsi_add_device); 1495 1496 int scsi_add_device(struct Scsi_Host *host, uint channel, 1497 uint target, u64 lun) 1498 { 1499 struct scsi_device *sdev = 1500 __scsi_add_device(host, channel, target, lun, NULL); 1501 if (IS_ERR(sdev)) 1502 return PTR_ERR(sdev); 1503 1504 scsi_device_put(sdev); 1505 return 0; 1506 } 1507 EXPORT_SYMBOL(scsi_add_device); 1508 1509 void scsi_rescan_device(struct device *dev) 1510 { 1511 struct scsi_device *sdev = to_scsi_device(dev); 1512 1513 device_lock(dev); 1514 1515 scsi_attach_vpd(sdev); 1516 1517 if (sdev->handler && sdev->handler->rescan) 1518 sdev->handler->rescan(sdev); 1519 1520 if (dev->driver && try_module_get(dev->driver->owner)) { 1521 struct scsi_driver *drv = to_scsi_driver(dev->driver); 1522 1523 if (drv->rescan) 1524 drv->rescan(dev); 1525 module_put(dev->driver->owner); 1526 } 1527 device_unlock(dev); 1528 } 1529 EXPORT_SYMBOL(scsi_rescan_device); 1530 1531 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1532 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1533 { 1534 struct Scsi_Host *shost = dev_to_shost(parent); 1535 blist_flags_t bflags = 0; 1536 int res; 1537 struct scsi_target *starget; 1538 1539 if (shost->this_id == id) 1540 /* 1541 * Don't scan the host adapter 1542 */ 1543 return; 1544 1545 starget = scsi_alloc_target(parent, channel, id); 1546 if (!starget) 1547 return; 1548 scsi_autopm_get_target(starget); 1549 1550 if (lun != SCAN_WILD_CARD) { 1551 /* 1552 * Scan for a specific host/chan/id/lun. 1553 */ 1554 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1555 goto out_reap; 1556 } 1557 1558 /* 1559 * Scan LUN 0, if there is some response, scan further. Ideally, we 1560 * would not configure LUN 0 until all LUNs are scanned. 1561 */ 1562 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1563 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1564 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1565 /* 1566 * The REPORT LUN did not scan the target, 1567 * do a sequential scan. 1568 */ 1569 scsi_sequential_lun_scan(starget, bflags, 1570 starget->scsi_level, rescan); 1571 } 1572 1573 out_reap: 1574 scsi_autopm_put_target(starget); 1575 /* 1576 * paired with scsi_alloc_target(): determine if the target has 1577 * any children at all and if not, nuke it 1578 */ 1579 scsi_target_reap(starget); 1580 1581 put_device(&starget->dev); 1582 } 1583 1584 /** 1585 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1586 * @parent: host to scan 1587 * @channel: channel to scan 1588 * @id: target id to scan 1589 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1590 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for 1591 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs, 1592 * and SCSI_SCAN_MANUAL to force scanning even if 1593 * 'scan=manual' is set. 1594 * 1595 * Description: 1596 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1597 * and possibly all LUNs on the target id. 1598 * 1599 * First try a REPORT LUN scan, if that does not scan the target, do a 1600 * sequential scan of LUNs on the target id. 1601 **/ 1602 void scsi_scan_target(struct device *parent, unsigned int channel, 1603 unsigned int id, u64 lun, enum scsi_scan_mode rescan) 1604 { 1605 struct Scsi_Host *shost = dev_to_shost(parent); 1606 1607 if (strncmp(scsi_scan_type, "none", 4) == 0) 1608 return; 1609 1610 if (rescan != SCSI_SCAN_MANUAL && 1611 strncmp(scsi_scan_type, "manual", 6) == 0) 1612 return; 1613 1614 mutex_lock(&shost->scan_mutex); 1615 if (!shost->async_scan) 1616 scsi_complete_async_scans(); 1617 1618 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1619 __scsi_scan_target(parent, channel, id, lun, rescan); 1620 scsi_autopm_put_host(shost); 1621 } 1622 mutex_unlock(&shost->scan_mutex); 1623 } 1624 EXPORT_SYMBOL(scsi_scan_target); 1625 1626 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1627 unsigned int id, u64 lun, 1628 enum scsi_scan_mode rescan) 1629 { 1630 uint order_id; 1631 1632 if (id == SCAN_WILD_CARD) 1633 for (id = 0; id < shost->max_id; ++id) { 1634 /* 1635 * XXX adapter drivers when possible (FCP, iSCSI) 1636 * could modify max_id to match the current max, 1637 * not the absolute max. 1638 * 1639 * XXX add a shost id iterator, so for example, 1640 * the FC ID can be the same as a target id 1641 * without a huge overhead of sparse id's. 1642 */ 1643 if (shost->reverse_ordering) 1644 /* 1645 * Scan from high to low id. 1646 */ 1647 order_id = shost->max_id - id - 1; 1648 else 1649 order_id = id; 1650 __scsi_scan_target(&shost->shost_gendev, channel, 1651 order_id, lun, rescan); 1652 } 1653 else 1654 __scsi_scan_target(&shost->shost_gendev, channel, 1655 id, lun, rescan); 1656 } 1657 1658 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1659 unsigned int id, u64 lun, 1660 enum scsi_scan_mode rescan) 1661 { 1662 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1663 "%s: <%u:%u:%llu>\n", 1664 __func__, channel, id, lun)); 1665 1666 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1667 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1668 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun))) 1669 return -EINVAL; 1670 1671 mutex_lock(&shost->scan_mutex); 1672 if (!shost->async_scan) 1673 scsi_complete_async_scans(); 1674 1675 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1676 if (channel == SCAN_WILD_CARD) 1677 for (channel = 0; channel <= shost->max_channel; 1678 channel++) 1679 scsi_scan_channel(shost, channel, id, lun, 1680 rescan); 1681 else 1682 scsi_scan_channel(shost, channel, id, lun, rescan); 1683 scsi_autopm_put_host(shost); 1684 } 1685 mutex_unlock(&shost->scan_mutex); 1686 1687 return 0; 1688 } 1689 1690 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1691 { 1692 struct scsi_device *sdev; 1693 shost_for_each_device(sdev, shost) { 1694 /* target removed before the device could be added */ 1695 if (sdev->sdev_state == SDEV_DEL) 1696 continue; 1697 /* If device is already visible, skip adding it to sysfs */ 1698 if (sdev->is_visible) 1699 continue; 1700 if (!scsi_host_scan_allowed(shost) || 1701 scsi_sysfs_add_sdev(sdev) != 0) 1702 __scsi_remove_device(sdev); 1703 } 1704 } 1705 1706 /** 1707 * scsi_prep_async_scan - prepare for an async scan 1708 * @shost: the host which will be scanned 1709 * Returns: a cookie to be passed to scsi_finish_async_scan() 1710 * 1711 * Tells the midlayer this host is going to do an asynchronous scan. 1712 * It reserves the host's position in the scanning list and ensures 1713 * that other asynchronous scans started after this one won't affect the 1714 * ordering of the discovered devices. 1715 */ 1716 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1717 { 1718 struct async_scan_data *data; 1719 unsigned long flags; 1720 1721 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1722 return NULL; 1723 1724 if (shost->async_scan) { 1725 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); 1726 return NULL; 1727 } 1728 1729 data = kmalloc(sizeof(*data), GFP_KERNEL); 1730 if (!data) 1731 goto err; 1732 data->shost = scsi_host_get(shost); 1733 if (!data->shost) 1734 goto err; 1735 init_completion(&data->prev_finished); 1736 1737 mutex_lock(&shost->scan_mutex); 1738 spin_lock_irqsave(shost->host_lock, flags); 1739 shost->async_scan = 1; 1740 spin_unlock_irqrestore(shost->host_lock, flags); 1741 mutex_unlock(&shost->scan_mutex); 1742 1743 spin_lock(&async_scan_lock); 1744 if (list_empty(&scanning_hosts)) 1745 complete(&data->prev_finished); 1746 list_add_tail(&data->list, &scanning_hosts); 1747 spin_unlock(&async_scan_lock); 1748 1749 return data; 1750 1751 err: 1752 kfree(data); 1753 return NULL; 1754 } 1755 1756 /** 1757 * scsi_finish_async_scan - asynchronous scan has finished 1758 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1759 * 1760 * All the devices currently attached to this host have been found. 1761 * This function announces all the devices it has found to the rest 1762 * of the system. 1763 */ 1764 static void scsi_finish_async_scan(struct async_scan_data *data) 1765 { 1766 struct Scsi_Host *shost; 1767 unsigned long flags; 1768 1769 if (!data) 1770 return; 1771 1772 shost = data->shost; 1773 1774 mutex_lock(&shost->scan_mutex); 1775 1776 if (!shost->async_scan) { 1777 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__); 1778 dump_stack(); 1779 mutex_unlock(&shost->scan_mutex); 1780 return; 1781 } 1782 1783 wait_for_completion(&data->prev_finished); 1784 1785 scsi_sysfs_add_devices(shost); 1786 1787 spin_lock_irqsave(shost->host_lock, flags); 1788 shost->async_scan = 0; 1789 spin_unlock_irqrestore(shost->host_lock, flags); 1790 1791 mutex_unlock(&shost->scan_mutex); 1792 1793 spin_lock(&async_scan_lock); 1794 list_del(&data->list); 1795 if (!list_empty(&scanning_hosts)) { 1796 struct async_scan_data *next = list_entry(scanning_hosts.next, 1797 struct async_scan_data, list); 1798 complete(&next->prev_finished); 1799 } 1800 spin_unlock(&async_scan_lock); 1801 1802 scsi_autopm_put_host(shost); 1803 scsi_host_put(shost); 1804 kfree(data); 1805 } 1806 1807 static void do_scsi_scan_host(struct Scsi_Host *shost) 1808 { 1809 if (shost->hostt->scan_finished) { 1810 unsigned long start = jiffies; 1811 if (shost->hostt->scan_start) 1812 shost->hostt->scan_start(shost); 1813 1814 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1815 msleep(10); 1816 } else { 1817 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1818 SCAN_WILD_CARD, 0); 1819 } 1820 } 1821 1822 static void do_scan_async(void *_data, async_cookie_t c) 1823 { 1824 struct async_scan_data *data = _data; 1825 struct Scsi_Host *shost = data->shost; 1826 1827 do_scsi_scan_host(shost); 1828 scsi_finish_async_scan(data); 1829 } 1830 1831 /** 1832 * scsi_scan_host - scan the given adapter 1833 * @shost: adapter to scan 1834 **/ 1835 void scsi_scan_host(struct Scsi_Host *shost) 1836 { 1837 struct async_scan_data *data; 1838 1839 if (strncmp(scsi_scan_type, "none", 4) == 0 || 1840 strncmp(scsi_scan_type, "manual", 6) == 0) 1841 return; 1842 if (scsi_autopm_get_host(shost) < 0) 1843 return; 1844 1845 data = scsi_prep_async_scan(shost); 1846 if (!data) { 1847 do_scsi_scan_host(shost); 1848 scsi_autopm_put_host(shost); 1849 return; 1850 } 1851 1852 /* register with the async subsystem so wait_for_device_probe() 1853 * will flush this work 1854 */ 1855 async_schedule(do_scan_async, data); 1856 1857 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 1858 } 1859 EXPORT_SYMBOL(scsi_scan_host); 1860 1861 void scsi_forget_host(struct Scsi_Host *shost) 1862 { 1863 struct scsi_device *sdev; 1864 unsigned long flags; 1865 1866 restart: 1867 spin_lock_irqsave(shost->host_lock, flags); 1868 list_for_each_entry(sdev, &shost->__devices, siblings) { 1869 if (sdev->sdev_state == SDEV_DEL) 1870 continue; 1871 spin_unlock_irqrestore(shost->host_lock, flags); 1872 __scsi_remove_device(sdev); 1873 goto restart; 1874 } 1875 spin_unlock_irqrestore(shost->host_lock, flags); 1876 } 1877 1878 /** 1879 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself 1880 * @shost: Host that needs a scsi_device 1881 * 1882 * Lock status: None assumed. 1883 * 1884 * Returns: The scsi_device or NULL 1885 * 1886 * Notes: 1887 * Attach a single scsi_device to the Scsi_Host - this should 1888 * be made to look like a "pseudo-device" that points to the 1889 * HA itself. 1890 * 1891 * Note - this device is not accessible from any high-level 1892 * drivers (including generics), which is probably not 1893 * optimal. We can add hooks later to attach. 1894 */ 1895 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1896 { 1897 struct scsi_device *sdev = NULL; 1898 struct scsi_target *starget; 1899 1900 mutex_lock(&shost->scan_mutex); 1901 if (!scsi_host_scan_allowed(shost)) 1902 goto out; 1903 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1904 if (!starget) 1905 goto out; 1906 1907 sdev = scsi_alloc_sdev(starget, 0, NULL); 1908 if (sdev) 1909 sdev->borken = 0; 1910 else 1911 scsi_target_reap(starget); 1912 put_device(&starget->dev); 1913 out: 1914 mutex_unlock(&shost->scan_mutex); 1915 return sdev; 1916 } 1917 EXPORT_SYMBOL(scsi_get_host_dev); 1918 1919 /** 1920 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself 1921 * @sdev: Host device to be freed 1922 * 1923 * Lock status: None assumed. 1924 * 1925 * Returns: Nothing 1926 */ 1927 void scsi_free_host_dev(struct scsi_device *sdev) 1928 { 1929 BUG_ON(sdev->id != sdev->host->this_id); 1930 1931 __scsi_remove_device(sdev); 1932 } 1933 EXPORT_SYMBOL(scsi_free_host_dev); 1934 1935