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