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 38 #include <scsi/scsi.h> 39 #include <scsi/scsi_cmnd.h> 40 #include <scsi/scsi_device.h> 41 #include <scsi/scsi_driver.h> 42 #include <scsi/scsi_devinfo.h> 43 #include <scsi/scsi_host.h> 44 #include <scsi/scsi_transport.h> 45 #include <scsi/scsi_eh.h> 46 47 #include "scsi_priv.h" 48 #include "scsi_logging.h" 49 50 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 51 " SCSI scanning, some SCSI devices might not be configured\n" 52 53 /* 54 * Default timeout 55 */ 56 #define SCSI_TIMEOUT (2*HZ) 57 58 /* 59 * Prefix values for the SCSI id's (stored in sysfs name field) 60 */ 61 #define SCSI_UID_SER_NUM 'S' 62 #define SCSI_UID_UNKNOWN 'Z' 63 64 /* 65 * Return values of some of the scanning functions. 66 * 67 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 68 * includes allocation or general failures preventing IO from being sent. 69 * 70 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 71 * on the given LUN. 72 * 73 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 74 * given LUN. 75 */ 76 #define SCSI_SCAN_NO_RESPONSE 0 77 #define SCSI_SCAN_TARGET_PRESENT 1 78 #define SCSI_SCAN_LUN_PRESENT 2 79 80 static const char *scsi_null_device_strs = "nullnullnullnull"; 81 82 #define MAX_SCSI_LUNS 512 83 84 #ifdef CONFIG_SCSI_MULTI_LUN 85 static unsigned int max_scsi_luns = MAX_SCSI_LUNS; 86 #else 87 static unsigned int max_scsi_luns = 1; 88 #endif 89 90 module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR); 91 MODULE_PARM_DESC(max_luns, 92 "last scsi LUN (should be between 1 and 2^32-1)"); 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 static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT; 101 102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO); 103 MODULE_PARM_DESC(scan, "sync, async or none"); 104 105 /* 106 * max_scsi_report_luns: the maximum number of LUNS that will be 107 * returned from the REPORT LUNS command. 8 times this value must 108 * be allocated. In theory this could be up to an 8 byte value, but 109 * in practice, the maximum number of LUNs suppored by any device 110 * is about 16k. 111 */ 112 static unsigned int max_scsi_report_luns = 511; 113 114 module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR); 115 MODULE_PARM_DESC(max_report_luns, 116 "REPORT LUNS maximum number of LUNS received (should be" 117 " between 1 and 16384)"); 118 119 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18; 120 121 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR); 122 MODULE_PARM_DESC(inq_timeout, 123 "Timeout (in seconds) waiting for devices to answer INQUIRY." 124 " Default is 20. Some devices may need more; most need less."); 125 126 /* This lock protects only this list */ 127 static DEFINE_SPINLOCK(async_scan_lock); 128 static LIST_HEAD(scanning_hosts); 129 130 struct async_scan_data { 131 struct list_head list; 132 struct Scsi_Host *shost; 133 struct completion prev_finished; 134 }; 135 136 /** 137 * scsi_complete_async_scans - Wait for asynchronous scans to complete 138 * 139 * When this function returns, any host which started scanning before 140 * this function was called will have finished its scan. Hosts which 141 * started scanning after this function was called may or may not have 142 * finished. 143 */ 144 int scsi_complete_async_scans(void) 145 { 146 struct async_scan_data *data; 147 148 do { 149 if (list_empty(&scanning_hosts)) 150 return 0; 151 /* If we can't get memory immediately, that's OK. Just 152 * sleep a little. Even if we never get memory, the async 153 * scans will finish eventually. 154 */ 155 data = kmalloc(sizeof(*data), GFP_KERNEL); 156 if (!data) 157 msleep(1); 158 } while (!data); 159 160 data->shost = NULL; 161 init_completion(&data->prev_finished); 162 163 spin_lock(&async_scan_lock); 164 /* Check that there's still somebody else on the list */ 165 if (list_empty(&scanning_hosts)) 166 goto done; 167 list_add_tail(&data->list, &scanning_hosts); 168 spin_unlock(&async_scan_lock); 169 170 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 171 wait_for_completion(&data->prev_finished); 172 173 spin_lock(&async_scan_lock); 174 list_del(&data->list); 175 if (!list_empty(&scanning_hosts)) { 176 struct async_scan_data *next = list_entry(scanning_hosts.next, 177 struct async_scan_data, list); 178 complete(&next->prev_finished); 179 } 180 done: 181 spin_unlock(&async_scan_lock); 182 183 kfree(data); 184 return 0; 185 } 186 187 /* Only exported for the benefit of scsi_wait_scan */ 188 EXPORT_SYMBOL_GPL(scsi_complete_async_scans); 189 190 #ifndef MODULE 191 /* 192 * For async scanning we need to wait for all the scans to complete before 193 * trying to mount the root fs. Otherwise non-modular drivers may not be ready 194 * yet. 195 */ 196 late_initcall(scsi_complete_async_scans); 197 #endif 198 199 /** 200 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 201 * @sdev: scsi device to send command to 202 * @result: area to store the result of the MODE SENSE 203 * 204 * Description: 205 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 206 * Called for BLIST_KEY devices. 207 **/ 208 static void scsi_unlock_floptical(struct scsi_device *sdev, 209 unsigned char *result) 210 { 211 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 212 213 printk(KERN_NOTICE "scsi: unlocking floptical drive\n"); 214 scsi_cmd[0] = MODE_SENSE; 215 scsi_cmd[1] = 0; 216 scsi_cmd[2] = 0x2e; 217 scsi_cmd[3] = 0; 218 scsi_cmd[4] = 0x2a; /* size */ 219 scsi_cmd[5] = 0; 220 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 221 SCSI_TIMEOUT, 3, NULL); 222 } 223 224 /** 225 * scsi_alloc_sdev - allocate and setup a scsi_Device 226 * @starget: which target to allocate a &scsi_device for 227 * @lun: which lun 228 * @hostdata: usually NULL and set by ->slave_alloc instead 229 * 230 * Description: 231 * Allocate, initialize for io, and return a pointer to a scsi_Device. 232 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 233 * adds scsi_Device to the appropriate list. 234 * 235 * Return value: 236 * scsi_Device pointer, or NULL on failure. 237 **/ 238 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 239 unsigned int lun, void *hostdata) 240 { 241 struct scsi_device *sdev; 242 int display_failure_msg = 1, ret; 243 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 244 extern void scsi_evt_thread(struct work_struct *work); 245 246 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 247 GFP_ATOMIC); 248 if (!sdev) 249 goto out; 250 251 sdev->vendor = scsi_null_device_strs; 252 sdev->model = scsi_null_device_strs; 253 sdev->rev = scsi_null_device_strs; 254 sdev->host = shost; 255 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 256 sdev->id = starget->id; 257 sdev->lun = lun; 258 sdev->channel = starget->channel; 259 sdev->sdev_state = SDEV_CREATED; 260 INIT_LIST_HEAD(&sdev->siblings); 261 INIT_LIST_HEAD(&sdev->same_target_siblings); 262 INIT_LIST_HEAD(&sdev->cmd_list); 263 INIT_LIST_HEAD(&sdev->starved_entry); 264 INIT_LIST_HEAD(&sdev->event_list); 265 spin_lock_init(&sdev->list_lock); 266 INIT_WORK(&sdev->event_work, scsi_evt_thread); 267 268 sdev->sdev_gendev.parent = get_device(&starget->dev); 269 sdev->sdev_target = starget; 270 271 /* usually NULL and set by ->slave_alloc instead */ 272 sdev->hostdata = hostdata; 273 274 /* if the device needs this changing, it may do so in the 275 * slave_configure function */ 276 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 277 278 /* 279 * Some low level driver could use device->type 280 */ 281 sdev->type = -1; 282 283 /* 284 * Assume that the device will have handshaking problems, 285 * and then fix this field later if it turns out it 286 * doesn't 287 */ 288 sdev->borken = 1; 289 290 sdev->request_queue = scsi_alloc_queue(sdev); 291 if (!sdev->request_queue) { 292 /* release fn is set up in scsi_sysfs_device_initialise, so 293 * have to free and put manually here */ 294 put_device(&starget->dev); 295 kfree(sdev); 296 goto out; 297 } 298 299 sdev->request_queue->queuedata = sdev; 300 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); 301 302 scsi_sysfs_device_initialize(sdev); 303 304 if (shost->hostt->slave_alloc) { 305 ret = shost->hostt->slave_alloc(sdev); 306 if (ret) { 307 /* 308 * if LLDD reports slave not present, don't clutter 309 * console with alloc failure messages 310 */ 311 if (ret == -ENXIO) 312 display_failure_msg = 0; 313 goto out_device_destroy; 314 } 315 } 316 317 return sdev; 318 319 out_device_destroy: 320 scsi_device_set_state(sdev, SDEV_DEL); 321 transport_destroy_device(&sdev->sdev_gendev); 322 put_device(&sdev->sdev_dev); 323 put_device(&sdev->sdev_gendev); 324 out: 325 if (display_failure_msg) 326 printk(ALLOC_FAILURE_MSG, __func__); 327 return NULL; 328 } 329 330 static void scsi_target_destroy(struct scsi_target *starget) 331 { 332 struct device *dev = &starget->dev; 333 struct Scsi_Host *shost = dev_to_shost(dev->parent); 334 unsigned long flags; 335 336 transport_destroy_device(dev); 337 spin_lock_irqsave(shost->host_lock, flags); 338 if (shost->hostt->target_destroy) 339 shost->hostt->target_destroy(starget); 340 list_del_init(&starget->siblings); 341 spin_unlock_irqrestore(shost->host_lock, flags); 342 put_device(dev); 343 } 344 345 static void scsi_target_dev_release(struct device *dev) 346 { 347 struct device *parent = dev->parent; 348 struct scsi_target *starget = to_scsi_target(dev); 349 350 kfree(starget); 351 put_device(parent); 352 } 353 354 static struct device_type scsi_target_type = { 355 .name = "scsi_target", 356 .release = scsi_target_dev_release, 357 }; 358 359 int scsi_is_target_device(const struct device *dev) 360 { 361 return dev->type == &scsi_target_type; 362 } 363 EXPORT_SYMBOL(scsi_is_target_device); 364 365 static struct scsi_target *__scsi_find_target(struct device *parent, 366 int channel, uint id) 367 { 368 struct scsi_target *starget, *found_starget = NULL; 369 struct Scsi_Host *shost = dev_to_shost(parent); 370 /* 371 * Search for an existing target for this sdev. 372 */ 373 list_for_each_entry(starget, &shost->__targets, siblings) { 374 if (starget->id == id && 375 starget->channel == channel) { 376 found_starget = starget; 377 break; 378 } 379 } 380 if (found_starget) 381 get_device(&found_starget->dev); 382 383 return found_starget; 384 } 385 386 /** 387 * scsi_alloc_target - allocate a new or find an existing target 388 * @parent: parent of the target (need not be a scsi host) 389 * @channel: target channel number (zero if no channels) 390 * @id: target id number 391 * 392 * Return an existing target if one exists, provided it hasn't already 393 * gone into STARGET_DEL state, otherwise allocate a new target. 394 * 395 * The target is returned with an incremented reference, so the caller 396 * is responsible for both reaping and doing a last put 397 */ 398 static struct scsi_target *scsi_alloc_target(struct device *parent, 399 int channel, uint id) 400 { 401 struct Scsi_Host *shost = dev_to_shost(parent); 402 struct device *dev = NULL; 403 unsigned long flags; 404 const int size = sizeof(struct scsi_target) 405 + shost->transportt->target_size; 406 struct scsi_target *starget; 407 struct scsi_target *found_target; 408 int error; 409 410 starget = kzalloc(size, GFP_KERNEL); 411 if (!starget) { 412 printk(KERN_ERR "%s: allocation failure\n", __func__); 413 return NULL; 414 } 415 dev = &starget->dev; 416 device_initialize(dev); 417 starget->reap_ref = 1; 418 dev->parent = get_device(parent); 419 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 420 dev->bus = &scsi_bus_type; 421 dev->type = &scsi_target_type; 422 starget->id = id; 423 starget->channel = channel; 424 starget->can_queue = 0; 425 INIT_LIST_HEAD(&starget->siblings); 426 INIT_LIST_HEAD(&starget->devices); 427 starget->state = STARGET_CREATED; 428 starget->scsi_level = SCSI_2; 429 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 430 retry: 431 spin_lock_irqsave(shost->host_lock, flags); 432 433 found_target = __scsi_find_target(parent, channel, id); 434 if (found_target) 435 goto found; 436 437 list_add_tail(&starget->siblings, &shost->__targets); 438 spin_unlock_irqrestore(shost->host_lock, flags); 439 /* allocate and add */ 440 transport_setup_device(dev); 441 if (shost->hostt->target_alloc) { 442 error = shost->hostt->target_alloc(starget); 443 444 if(error) { 445 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 446 /* don't want scsi_target_reap to do the final 447 * put because it will be under the host lock */ 448 scsi_target_destroy(starget); 449 return NULL; 450 } 451 } 452 get_device(dev); 453 454 return starget; 455 456 found: 457 found_target->reap_ref++; 458 spin_unlock_irqrestore(shost->host_lock, flags); 459 if (found_target->state != STARGET_DEL) { 460 put_device(dev); 461 return found_target; 462 } 463 /* Unfortunately, we found a dying target; need to 464 * wait until it's dead before we can get a new one */ 465 put_device(&found_target->dev); 466 flush_scheduled_work(); 467 goto retry; 468 } 469 470 static void scsi_target_reap_usercontext(struct work_struct *work) 471 { 472 struct scsi_target *starget = 473 container_of(work, struct scsi_target, ew.work); 474 475 transport_remove_device(&starget->dev); 476 device_del(&starget->dev); 477 scsi_target_destroy(starget); 478 } 479 480 /** 481 * scsi_target_reap - check to see if target is in use and destroy if not 482 * @starget: target to be checked 483 * 484 * This is used after removing a LUN or doing a last put of the target 485 * it checks atomically that nothing is using the target and removes 486 * it if so. 487 */ 488 void scsi_target_reap(struct scsi_target *starget) 489 { 490 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 491 unsigned long flags; 492 enum scsi_target_state state; 493 int empty = 0; 494 495 spin_lock_irqsave(shost->host_lock, flags); 496 state = starget->state; 497 if (--starget->reap_ref == 0 && list_empty(&starget->devices)) { 498 empty = 1; 499 starget->state = STARGET_DEL; 500 } 501 spin_unlock_irqrestore(shost->host_lock, flags); 502 503 if (!empty) 504 return; 505 506 BUG_ON(state == STARGET_DEL); 507 if (state == STARGET_CREATED) 508 scsi_target_destroy(starget); 509 else 510 execute_in_process_context(scsi_target_reap_usercontext, 511 &starget->ew); 512 } 513 514 /** 515 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string 516 * @s: INQUIRY result string to sanitize 517 * @len: length of the string 518 * 519 * Description: 520 * The SCSI spec says that INQUIRY vendor, product, and revision 521 * strings must consist entirely of graphic ASCII characters, 522 * padded on the right with spaces. Since not all devices obey 523 * this rule, we will replace non-graphic or non-ASCII characters 524 * with spaces. Exception: a NUL character is interpreted as a 525 * string terminator, so all the following characters are set to 526 * spaces. 527 **/ 528 static void sanitize_inquiry_string(unsigned char *s, int len) 529 { 530 int terminated = 0; 531 532 for (; len > 0; (--len, ++s)) { 533 if (*s == 0) 534 terminated = 1; 535 if (terminated || *s < 0x20 || *s > 0x7e) 536 *s = ' '; 537 } 538 } 539 540 /** 541 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 542 * @sdev: scsi_device to probe 543 * @inq_result: area to store the INQUIRY result 544 * @result_len: len of inq_result 545 * @bflags: store any bflags found here 546 * 547 * Description: 548 * Probe the lun associated with @req using a standard SCSI INQUIRY; 549 * 550 * If the INQUIRY is successful, zero is returned and the 551 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 552 * are copied to the scsi_device any flags value is stored in *@bflags. 553 **/ 554 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 555 int result_len, int *bflags) 556 { 557 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 558 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 559 int response_len = 0; 560 int pass, count, result; 561 struct scsi_sense_hdr sshdr; 562 563 *bflags = 0; 564 565 /* Perform up to 3 passes. The first pass uses a conservative 566 * transfer length of 36 unless sdev->inquiry_len specifies a 567 * different value. */ 568 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 569 try_inquiry_len = first_inquiry_len; 570 pass = 1; 571 572 next_pass: 573 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 574 "scsi scan: INQUIRY pass %d length %d\n", 575 pass, try_inquiry_len)); 576 577 /* Each pass gets up to three chances to ignore Unit Attention */ 578 for (count = 0; count < 3; ++count) { 579 int resid; 580 581 memset(scsi_cmd, 0, 6); 582 scsi_cmd[0] = INQUIRY; 583 scsi_cmd[4] = (unsigned char) try_inquiry_len; 584 585 memset(inq_result, 0, try_inquiry_len); 586 587 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 588 inq_result, try_inquiry_len, &sshdr, 589 HZ / 2 + HZ * scsi_inq_timeout, 3, 590 &resid); 591 592 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s " 593 "with code 0x%x\n", 594 result ? "failed" : "successful", result)); 595 596 if (result) { 597 /* 598 * not-ready to ready transition [asc/ascq=0x28/0x0] 599 * or power-on, reset [asc/ascq=0x29/0x0], continue. 600 * INQUIRY should not yield UNIT_ATTENTION 601 * but many buggy devices do so anyway. 602 */ 603 if ((driver_byte(result) & DRIVER_SENSE) && 604 scsi_sense_valid(&sshdr)) { 605 if ((sshdr.sense_key == UNIT_ATTENTION) && 606 ((sshdr.asc == 0x28) || 607 (sshdr.asc == 0x29)) && 608 (sshdr.ascq == 0)) 609 continue; 610 } 611 } else { 612 /* 613 * if nothing was transferred, we try 614 * again. It's a workaround for some USB 615 * devices. 616 */ 617 if (resid == try_inquiry_len) 618 continue; 619 } 620 break; 621 } 622 623 if (result == 0) { 624 sanitize_inquiry_string(&inq_result[8], 8); 625 sanitize_inquiry_string(&inq_result[16], 16); 626 sanitize_inquiry_string(&inq_result[32], 4); 627 628 response_len = inq_result[4] + 5; 629 if (response_len > 255) 630 response_len = first_inquiry_len; /* sanity */ 631 632 /* 633 * Get any flags for this device. 634 * 635 * XXX add a bflags to scsi_device, and replace the 636 * corresponding bit fields in scsi_device, so bflags 637 * need not be passed as an argument. 638 */ 639 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 640 &inq_result[16]); 641 642 /* When the first pass succeeds we gain information about 643 * what larger transfer lengths might work. */ 644 if (pass == 1) { 645 if (BLIST_INQUIRY_36 & *bflags) 646 next_inquiry_len = 36; 647 else if (BLIST_INQUIRY_58 & *bflags) 648 next_inquiry_len = 58; 649 else if (sdev->inquiry_len) 650 next_inquiry_len = sdev->inquiry_len; 651 else 652 next_inquiry_len = response_len; 653 654 /* If more data is available perform the second pass */ 655 if (next_inquiry_len > try_inquiry_len) { 656 try_inquiry_len = next_inquiry_len; 657 pass = 2; 658 goto next_pass; 659 } 660 } 661 662 } else if (pass == 2) { 663 printk(KERN_INFO "scsi scan: %d byte inquiry failed. " 664 "Consider BLIST_INQUIRY_36 for this device\n", 665 try_inquiry_len); 666 667 /* If this pass failed, the third pass goes back and transfers 668 * the same amount as we successfully got in the first pass. */ 669 try_inquiry_len = first_inquiry_len; 670 pass = 3; 671 goto next_pass; 672 } 673 674 /* If the last transfer attempt got an error, assume the 675 * peripheral doesn't exist or is dead. */ 676 if (result) 677 return -EIO; 678 679 /* Don't report any more data than the device says is valid */ 680 sdev->inquiry_len = min(try_inquiry_len, response_len); 681 682 /* 683 * XXX Abort if the response length is less than 36? If less than 684 * 32, the lookup of the device flags (above) could be invalid, 685 * and it would be possible to take an incorrect action - we do 686 * not want to hang because of a short INQUIRY. On the flip side, 687 * if the device is spun down or becoming ready (and so it gives a 688 * short INQUIRY), an abort here prevents any further use of the 689 * device, including spin up. 690 * 691 * On the whole, the best approach seems to be to assume the first 692 * 36 bytes are valid no matter what the device says. That's 693 * better than copying < 36 bytes to the inquiry-result buffer 694 * and displaying garbage for the Vendor, Product, or Revision 695 * strings. 696 */ 697 if (sdev->inquiry_len < 36) { 698 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d)," 699 " using 36\n", sdev->inquiry_len); 700 sdev->inquiry_len = 36; 701 } 702 703 /* 704 * Related to the above issue: 705 * 706 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 707 * and if not ready, sent a START_STOP to start (maybe spin up) and 708 * then send the INQUIRY again, since the INQUIRY can change after 709 * a device is initialized. 710 * 711 * Ideally, start a device if explicitly asked to do so. This 712 * assumes that a device is spun up on power on, spun down on 713 * request, and then spun up on request. 714 */ 715 716 /* 717 * The scanning code needs to know the scsi_level, even if no 718 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 719 * non-zero LUNs can be scanned. 720 */ 721 sdev->scsi_level = inq_result[2] & 0x07; 722 if (sdev->scsi_level >= 2 || 723 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 724 sdev->scsi_level++; 725 sdev->sdev_target->scsi_level = sdev->scsi_level; 726 727 return 0; 728 } 729 730 /** 731 * scsi_add_lun - allocate and fully initialze a scsi_device 732 * @sdev: holds information to be stored in the new scsi_device 733 * @inq_result: holds the result of a previous INQUIRY to the LUN 734 * @bflags: black/white list flag 735 * @async: 1 if this device is being scanned asynchronously 736 * 737 * Description: 738 * Initialize the scsi_device @sdev. Optionally set fields based 739 * on values in *@bflags. 740 * 741 * Return: 742 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 743 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 744 **/ 745 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 746 int *bflags, int async) 747 { 748 int ret; 749 750 /* 751 * XXX do not save the inquiry, since it can change underneath us, 752 * save just vendor/model/rev. 753 * 754 * Rather than save it and have an ioctl that retrieves the saved 755 * value, have an ioctl that executes the same INQUIRY code used 756 * in scsi_probe_lun, let user level programs doing INQUIRY 757 * scanning run at their own risk, or supply a user level program 758 * that can correctly scan. 759 */ 760 761 /* 762 * Copy at least 36 bytes of INQUIRY data, so that we don't 763 * dereference unallocated memory when accessing the Vendor, 764 * Product, and Revision strings. Badly behaved devices may set 765 * the INQUIRY Additional Length byte to a small value, indicating 766 * these strings are invalid, but often they contain plausible data 767 * nonetheless. It doesn't matter if the device sent < 36 bytes 768 * total, since scsi_probe_lun() initializes inq_result with 0s. 769 */ 770 sdev->inquiry = kmemdup(inq_result, 771 max_t(size_t, sdev->inquiry_len, 36), 772 GFP_ATOMIC); 773 if (sdev->inquiry == NULL) 774 return SCSI_SCAN_NO_RESPONSE; 775 776 sdev->vendor = (char *) (sdev->inquiry + 8); 777 sdev->model = (char *) (sdev->inquiry + 16); 778 sdev->rev = (char *) (sdev->inquiry + 32); 779 780 if (*bflags & BLIST_ISROM) { 781 sdev->type = TYPE_ROM; 782 sdev->removable = 1; 783 } else { 784 sdev->type = (inq_result[0] & 0x1f); 785 sdev->removable = (inq_result[1] & 0x80) >> 7; 786 } 787 788 switch (sdev->type) { 789 case TYPE_RBC: 790 case TYPE_TAPE: 791 case TYPE_DISK: 792 case TYPE_PRINTER: 793 case TYPE_MOD: 794 case TYPE_PROCESSOR: 795 case TYPE_SCANNER: 796 case TYPE_MEDIUM_CHANGER: 797 case TYPE_ENCLOSURE: 798 case TYPE_COMM: 799 case TYPE_RAID: 800 case TYPE_OSD: 801 sdev->writeable = 1; 802 break; 803 case TYPE_ROM: 804 case TYPE_WORM: 805 sdev->writeable = 0; 806 break; 807 default: 808 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type); 809 } 810 811 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 812 /* RBC and MMC devices can return SCSI-3 compliance and yet 813 * still not support REPORT LUNS, so make them act as 814 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 815 * specifically set */ 816 if ((*bflags & BLIST_REPORTLUN2) == 0) 817 *bflags |= BLIST_NOREPORTLUN; 818 } 819 820 /* 821 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 822 * spec says: The device server is capable of supporting the 823 * specified peripheral device type on this logical unit. However, 824 * the physical device is not currently connected to this logical 825 * unit. 826 * 827 * The above is vague, as it implies that we could treat 001 and 828 * 011 the same. Stay compatible with previous code, and create a 829 * scsi_device for a PQ of 1 830 * 831 * Don't set the device offline here; rather let the upper 832 * level drivers eval the PQ to decide whether they should 833 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 834 */ 835 836 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 837 sdev->lockable = sdev->removable; 838 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 839 840 if (sdev->scsi_level >= SCSI_3 || 841 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 842 sdev->ppr = 1; 843 if (inq_result[7] & 0x60) 844 sdev->wdtr = 1; 845 if (inq_result[7] & 0x10) 846 sdev->sdtr = 1; 847 848 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 849 "ANSI: %d%s\n", scsi_device_type(sdev->type), 850 sdev->vendor, sdev->model, sdev->rev, 851 sdev->inq_periph_qual, inq_result[2] & 0x07, 852 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 853 854 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 855 !(*bflags & BLIST_NOTQ)) 856 sdev->tagged_supported = 1; 857 858 /* 859 * Some devices (Texel CD ROM drives) have handshaking problems 860 * when used with the Seagate controllers. borken is initialized 861 * to 1, and then set it to 0 here. 862 */ 863 if ((*bflags & BLIST_BORKEN) == 0) 864 sdev->borken = 0; 865 866 if (*bflags & BLIST_NO_ULD_ATTACH) 867 sdev->no_uld_attach = 1; 868 869 /* 870 * Apparently some really broken devices (contrary to the SCSI 871 * standards) need to be selected without asserting ATN 872 */ 873 if (*bflags & BLIST_SELECT_NO_ATN) 874 sdev->select_no_atn = 1; 875 876 /* 877 * Maximum 512 sector transfer length 878 * broken RA4x00 Compaq Disk Array 879 */ 880 if (*bflags & BLIST_MAX_512) 881 blk_queue_max_hw_sectors(sdev->request_queue, 512); 882 883 /* 884 * Some devices may not want to have a start command automatically 885 * issued when a device is added. 886 */ 887 if (*bflags & BLIST_NOSTARTONADD) 888 sdev->no_start_on_add = 1; 889 890 if (*bflags & BLIST_SINGLELUN) 891 scsi_target(sdev)->single_lun = 1; 892 893 sdev->use_10_for_rw = 1; 894 895 if (*bflags & BLIST_MS_SKIP_PAGE_08) 896 sdev->skip_ms_page_8 = 1; 897 898 if (*bflags & BLIST_MS_SKIP_PAGE_3F) 899 sdev->skip_ms_page_3f = 1; 900 901 if (*bflags & BLIST_USE_10_BYTE_MS) 902 sdev->use_10_for_ms = 1; 903 904 /* set the device running here so that slave configure 905 * may do I/O */ 906 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 907 if (ret) { 908 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 909 910 if (ret) { 911 sdev_printk(KERN_ERR, sdev, 912 "in wrong state %s to complete scan\n", 913 scsi_device_state_name(sdev->sdev_state)); 914 return SCSI_SCAN_NO_RESPONSE; 915 } 916 } 917 918 if (*bflags & BLIST_MS_192_BYTES_FOR_3F) 919 sdev->use_192_bytes_for_3f = 1; 920 921 if (*bflags & BLIST_NOT_LOCKABLE) 922 sdev->lockable = 0; 923 924 if (*bflags & BLIST_RETRY_HWERROR) 925 sdev->retry_hwerror = 1; 926 927 transport_configure_device(&sdev->sdev_gendev); 928 929 if (sdev->host->hostt->slave_configure) { 930 ret = sdev->host->hostt->slave_configure(sdev); 931 if (ret) { 932 /* 933 * if LLDD reports slave not present, don't clutter 934 * console with alloc failure messages 935 */ 936 if (ret != -ENXIO) { 937 sdev_printk(KERN_ERR, sdev, 938 "failed to configure device\n"); 939 } 940 return SCSI_SCAN_NO_RESPONSE; 941 } 942 } 943 944 sdev->max_queue_depth = sdev->queue_depth; 945 946 /* 947 * Ok, the device is now all set up, we can 948 * register it and tell the rest of the kernel 949 * about it. 950 */ 951 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 952 return SCSI_SCAN_NO_RESPONSE; 953 954 return SCSI_SCAN_LUN_PRESENT; 955 } 956 957 #ifdef CONFIG_SCSI_LOGGING 958 /** 959 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 960 * @buf: Output buffer with at least end-first+1 bytes of space 961 * @inq: Inquiry buffer (input) 962 * @first: Offset of string into inq 963 * @end: Index after last character in inq 964 */ 965 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 966 unsigned first, unsigned end) 967 { 968 unsigned term = 0, idx; 969 970 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 971 if (inq[idx+first] > ' ') { 972 buf[idx] = inq[idx+first]; 973 term = idx+1; 974 } else { 975 buf[idx] = ' '; 976 } 977 } 978 buf[term] = 0; 979 return buf; 980 } 981 #endif 982 983 /** 984 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 985 * @starget: pointer to target device structure 986 * @lun: LUN of target device 987 * @bflagsp: store bflags here if not NULL 988 * @sdevp: probe the LUN corresponding to this scsi_device 989 * @rescan: if nonzero skip some code only needed on first scan 990 * @hostdata: passed to scsi_alloc_sdev() 991 * 992 * Description: 993 * Call scsi_probe_lun, if a LUN with an attached device is found, 994 * allocate and set it up by calling scsi_add_lun. 995 * 996 * Return: 997 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 998 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 999 * attached at the LUN 1000 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1001 **/ 1002 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1003 uint lun, int *bflagsp, 1004 struct scsi_device **sdevp, int rescan, 1005 void *hostdata) 1006 { 1007 struct scsi_device *sdev; 1008 unsigned char *result; 1009 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1010 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1011 1012 /* 1013 * The rescan flag is used as an optimization, the first scan of a 1014 * host adapter calls into here with rescan == 0. 1015 */ 1016 sdev = scsi_device_lookup_by_target(starget, lun); 1017 if (sdev) { 1018 if (rescan || !scsi_device_created(sdev)) { 1019 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1020 "scsi scan: device exists on %s\n", 1021 dev_name(&sdev->sdev_gendev))); 1022 if (sdevp) 1023 *sdevp = sdev; 1024 else 1025 scsi_device_put(sdev); 1026 1027 if (bflagsp) 1028 *bflagsp = scsi_get_device_flags(sdev, 1029 sdev->vendor, 1030 sdev->model); 1031 return SCSI_SCAN_LUN_PRESENT; 1032 } 1033 scsi_device_put(sdev); 1034 } else 1035 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1036 if (!sdev) 1037 goto out; 1038 1039 result = kmalloc(result_len, GFP_ATOMIC | 1040 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1041 if (!result) 1042 goto out_free_sdev; 1043 1044 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1045 goto out_free_result; 1046 1047 if (bflagsp) 1048 *bflagsp = bflags; 1049 /* 1050 * result contains valid SCSI INQUIRY data. 1051 */ 1052 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) { 1053 /* 1054 * For a Peripheral qualifier 3 (011b), the SCSI 1055 * spec says: The device server is not capable of 1056 * supporting a physical device on this logical 1057 * unit. 1058 * 1059 * For disks, this implies that there is no 1060 * logical disk configured at sdev->lun, but there 1061 * is a target id responding. 1062 */ 1063 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1064 " peripheral qualifier of 3, device not" 1065 " added\n")) 1066 if (lun == 0) { 1067 SCSI_LOG_SCAN_BUS(1, { 1068 unsigned char vend[9]; 1069 unsigned char mod[17]; 1070 1071 sdev_printk(KERN_INFO, sdev, 1072 "scsi scan: consider passing scsi_mod." 1073 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1074 scsi_inq_str(vend, result, 8, 16), 1075 scsi_inq_str(mod, result, 16, 32)); 1076 }); 1077 1078 } 1079 1080 res = SCSI_SCAN_TARGET_PRESENT; 1081 goto out_free_result; 1082 } 1083 1084 /* 1085 * Some targets may set slight variations of PQ and PDT to signal 1086 * that no LUN is present, so don't add sdev in these cases. 1087 * Two specific examples are: 1088 * 1) NetApp targets: return PQ=1, PDT=0x1f 1089 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1090 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1091 * 1092 * References: 1093 * 1) SCSI SPC-3, pp. 145-146 1094 * PQ=1: "A peripheral device having the specified peripheral 1095 * device type is not connected to this logical unit. However, the 1096 * device server is capable of supporting the specified peripheral 1097 * device type on this logical unit." 1098 * PDT=0x1f: "Unknown or no device type" 1099 * 2) USB UFI 1.0, p. 20 1100 * PDT=00h Direct-access device (floppy) 1101 * PDT=1Fh none (no FDD connected to the requested logical unit) 1102 */ 1103 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1104 (result[0] & 0x1f) == 0x1f && 1105 !scsi_is_wlun(lun)) { 1106 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1107 "scsi scan: peripheral device type" 1108 " of 31, no device added\n")); 1109 res = SCSI_SCAN_TARGET_PRESENT; 1110 goto out_free_result; 1111 } 1112 1113 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1114 if (res == SCSI_SCAN_LUN_PRESENT) { 1115 if (bflags & BLIST_KEY) { 1116 sdev->lockable = 0; 1117 scsi_unlock_floptical(sdev, result); 1118 } 1119 } 1120 1121 out_free_result: 1122 kfree(result); 1123 out_free_sdev: 1124 if (res == SCSI_SCAN_LUN_PRESENT) { 1125 if (sdevp) { 1126 if (scsi_device_get(sdev) == 0) { 1127 *sdevp = sdev; 1128 } else { 1129 __scsi_remove_device(sdev); 1130 res = SCSI_SCAN_NO_RESPONSE; 1131 } 1132 } 1133 } else 1134 __scsi_remove_device(sdev); 1135 out: 1136 return res; 1137 } 1138 1139 /** 1140 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1141 * @starget: pointer to target structure to scan 1142 * @bflags: black/white list flag for LUN 0 1143 * @scsi_level: Which version of the standard does this device adhere to 1144 * @rescan: passed to scsi_probe_add_lun() 1145 * 1146 * Description: 1147 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1148 * scanned) to some maximum lun until a LUN is found with no device 1149 * attached. Use the bflags to figure out any oddities. 1150 * 1151 * Modifies sdevscan->lun. 1152 **/ 1153 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1154 int bflags, int scsi_level, int rescan) 1155 { 1156 unsigned int sparse_lun, lun, max_dev_lun; 1157 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1158 1159 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of" 1160 "%s\n", dev_name(&starget->dev))); 1161 1162 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1163 /* 1164 * If this device is known to support sparse multiple units, 1165 * override the other settings, and scan all of them. Normally, 1166 * SCSI-3 devices should be scanned via the REPORT LUNS. 1167 */ 1168 if (bflags & BLIST_SPARSELUN) { 1169 max_dev_lun = shost->max_lun; 1170 sparse_lun = 1; 1171 } else 1172 sparse_lun = 0; 1173 1174 /* 1175 * If less than SCSI_1_CSS, and no special lun scaning, stop 1176 * scanning; this matches 2.4 behaviour, but could just be a bug 1177 * (to continue scanning a SCSI_1_CSS device). 1178 * 1179 * This test is broken. We might not have any device on lun0 for 1180 * a sparselun device, and if that's the case then how would we 1181 * know the real scsi_level, eh? It might make sense to just not 1182 * scan any SCSI_1 device for non-0 luns, but that check would best 1183 * go into scsi_alloc_sdev() and just have it return null when asked 1184 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1185 * 1186 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1187 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1188 == 0)) 1189 return; 1190 */ 1191 /* 1192 * If this device is known to support multiple units, override 1193 * the other settings, and scan all of them. 1194 */ 1195 if (bflags & BLIST_FORCELUN) 1196 max_dev_lun = shost->max_lun; 1197 /* 1198 * REGAL CDC-4X: avoid hang after LUN 4 1199 */ 1200 if (bflags & BLIST_MAX5LUN) 1201 max_dev_lun = min(5U, max_dev_lun); 1202 /* 1203 * Do not scan SCSI-2 or lower device past LUN 7, unless 1204 * BLIST_LARGELUN. 1205 */ 1206 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1207 max_dev_lun = min(8U, max_dev_lun); 1208 1209 /* 1210 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1211 * until we reach the max, or no LUN is found and we are not 1212 * sparse_lun. 1213 */ 1214 for (lun = 1; lun < max_dev_lun; ++lun) 1215 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1216 NULL) != SCSI_SCAN_LUN_PRESENT) && 1217 !sparse_lun) 1218 return; 1219 } 1220 1221 /** 1222 * scsilun_to_int - convert a scsi_lun to an int 1223 * @scsilun: struct scsi_lun to be converted. 1224 * 1225 * Description: 1226 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered 1227 * integer, and return the result. The caller must check for 1228 * truncation before using this function. 1229 * 1230 * Notes: 1231 * The struct scsi_lun is assumed to be four levels, with each level 1232 * effectively containing a SCSI byte-ordered (big endian) short; the 1233 * addressing bits of each level are ignored (the highest two bits). 1234 * For a description of the LUN format, post SCSI-3 see the SCSI 1235 * Architecture Model, for SCSI-3 see the SCSI Controller Commands. 1236 * 1237 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns 1238 * the integer: 0x0b030a04 1239 **/ 1240 int scsilun_to_int(struct scsi_lun *scsilun) 1241 { 1242 int i; 1243 unsigned int lun; 1244 1245 lun = 0; 1246 for (i = 0; i < sizeof(lun); i += 2) 1247 lun = lun | (((scsilun->scsi_lun[i] << 8) | 1248 scsilun->scsi_lun[i + 1]) << (i * 8)); 1249 return lun; 1250 } 1251 EXPORT_SYMBOL(scsilun_to_int); 1252 1253 /** 1254 * int_to_scsilun - reverts an int into a scsi_lun 1255 * @lun: integer to be reverted 1256 * @scsilun: struct scsi_lun to be set. 1257 * 1258 * Description: 1259 * Reverts the functionality of the scsilun_to_int, which packed 1260 * an 8-byte lun value into an int. This routine unpacks the int 1261 * back into the lun value. 1262 * Note: the scsilun_to_int() routine does not truly handle all 1263 * 8bytes of the lun value. This functions restores only as much 1264 * as was set by the routine. 1265 * 1266 * Notes: 1267 * Given an integer : 0x0b030a04, this function returns a 1268 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00 1269 * 1270 **/ 1271 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun) 1272 { 1273 int i; 1274 1275 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun)); 1276 1277 for (i = 0; i < sizeof(lun); i += 2) { 1278 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF; 1279 scsilun->scsi_lun[i+1] = lun & 0xFF; 1280 lun = lun >> 16; 1281 } 1282 } 1283 EXPORT_SYMBOL(int_to_scsilun); 1284 1285 /** 1286 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1287 * @starget: which target 1288 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1289 * @rescan: nonzero if we can skip code only needed on first scan 1290 * 1291 * Description: 1292 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1293 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1294 * 1295 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1296 * LUNs even if it's older than SCSI-3. 1297 * If BLIST_NOREPORTLUN is set, return 1 always. 1298 * If BLIST_NOLUN is set, return 0 always. 1299 * 1300 * Return: 1301 * 0: scan completed (or no memory, so further scanning is futile) 1302 * 1: could not scan with REPORT LUN 1303 **/ 1304 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, 1305 int rescan) 1306 { 1307 char devname[64]; 1308 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1309 unsigned int length; 1310 unsigned int lun; 1311 unsigned int num_luns; 1312 unsigned int retries; 1313 int result; 1314 struct scsi_lun *lunp, *lun_data; 1315 u8 *data; 1316 struct scsi_sense_hdr sshdr; 1317 struct scsi_device *sdev; 1318 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1319 int ret = 0; 1320 1321 /* 1322 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1323 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1324 * support more than 8 LUNs. 1325 */ 1326 if (bflags & BLIST_NOREPORTLUN) 1327 return 1; 1328 if (starget->scsi_level < SCSI_2 && 1329 starget->scsi_level != SCSI_UNKNOWN) 1330 return 1; 1331 if (starget->scsi_level < SCSI_3 && 1332 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1333 return 1; 1334 if (bflags & BLIST_NOLUN) 1335 return 0; 1336 1337 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1338 sdev = scsi_alloc_sdev(starget, 0, NULL); 1339 if (!sdev) 1340 return 0; 1341 if (scsi_device_get(sdev)) { 1342 __scsi_remove_device(sdev); 1343 return 0; 1344 } 1345 } 1346 1347 sprintf(devname, "host %d channel %d id %d", 1348 shost->host_no, sdev->channel, sdev->id); 1349 1350 /* 1351 * Allocate enough to hold the header (the same size as one scsi_lun) 1352 * plus the max number of luns we are requesting. 1353 * 1354 * Reallocating and trying again (with the exact amount we need) 1355 * would be nice, but then we need to somehow limit the size 1356 * allocated based on the available memory and the limits of 1357 * kmalloc - we don't want a kmalloc() failure of a huge value to 1358 * prevent us from finding any LUNs on this target. 1359 */ 1360 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun); 1361 lun_data = kmalloc(length, GFP_ATOMIC | 1362 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1363 if (!lun_data) { 1364 printk(ALLOC_FAILURE_MSG, __func__); 1365 goto out; 1366 } 1367 1368 scsi_cmd[0] = REPORT_LUNS; 1369 1370 /* 1371 * bytes 1 - 5: reserved, set to zero. 1372 */ 1373 memset(&scsi_cmd[1], 0, 5); 1374 1375 /* 1376 * bytes 6 - 9: length of the command. 1377 */ 1378 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff; 1379 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff; 1380 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff; 1381 scsi_cmd[9] = (unsigned char) length & 0xff; 1382 1383 scsi_cmd[10] = 0; /* reserved */ 1384 scsi_cmd[11] = 0; /* control */ 1385 1386 /* 1387 * We can get a UNIT ATTENTION, for example a power on/reset, so 1388 * retry a few times (like sd.c does for TEST UNIT READY). 1389 * Experience shows some combinations of adapter/devices get at 1390 * least two power on/resets. 1391 * 1392 * Illegal requests (for devices that do not support REPORT LUNS) 1393 * should come through as a check condition, and will not generate 1394 * a retry. 1395 */ 1396 for (retries = 0; retries < 3; retries++) { 1397 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending" 1398 " REPORT LUNS to %s (try %d)\n", devname, 1399 retries)); 1400 1401 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1402 lun_data, length, &sshdr, 1403 SCSI_TIMEOUT + 4 * HZ, 3, NULL); 1404 1405 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS" 1406 " %s (try %d) result 0x%x\n", result 1407 ? "failed" : "successful", retries, result)); 1408 if (result == 0) 1409 break; 1410 else if (scsi_sense_valid(&sshdr)) { 1411 if (sshdr.sense_key != UNIT_ATTENTION) 1412 break; 1413 } 1414 } 1415 1416 if (result) { 1417 /* 1418 * The device probably does not support a REPORT LUN command 1419 */ 1420 ret = 1; 1421 goto out_err; 1422 } 1423 1424 /* 1425 * Get the length from the first four bytes of lun_data. 1426 */ 1427 data = (u8 *) lun_data->scsi_lun; 1428 length = ((data[0] << 24) | (data[1] << 16) | 1429 (data[2] << 8) | (data[3] << 0)); 1430 1431 num_luns = (length / sizeof(struct scsi_lun)); 1432 if (num_luns > max_scsi_report_luns) { 1433 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)" 1434 " of %d luns reported, try increasing" 1435 " max_scsi_report_luns.\n", devname, 1436 max_scsi_report_luns, num_luns); 1437 num_luns = max_scsi_report_luns; 1438 } 1439 1440 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1441 "scsi scan: REPORT LUN scan\n")); 1442 1443 /* 1444 * Scan the luns in lun_data. The entry at offset 0 is really 1445 * the header, so start at 1 and go up to and including num_luns. 1446 */ 1447 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1448 lun = scsilun_to_int(lunp); 1449 1450 /* 1451 * Check if the unused part of lunp is non-zero, and so 1452 * does not fit in lun. 1453 */ 1454 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) { 1455 int i; 1456 1457 /* 1458 * Output an error displaying the LUN in byte order, 1459 * this differs from what linux would print for the 1460 * integer LUN value. 1461 */ 1462 printk(KERN_WARNING "scsi: %s lun 0x", devname); 1463 data = (char *)lunp->scsi_lun; 1464 for (i = 0; i < sizeof(struct scsi_lun); i++) 1465 printk("%02x", data[i]); 1466 printk(" has a LUN larger than currently supported.\n"); 1467 } else if (lun > sdev->host->max_lun) { 1468 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger" 1469 " than allowed by the host adapter\n", 1470 devname, lun); 1471 } else { 1472 int res; 1473 1474 res = scsi_probe_and_add_lun(starget, 1475 lun, NULL, NULL, rescan, NULL); 1476 if (res == SCSI_SCAN_NO_RESPONSE) { 1477 /* 1478 * Got some results, but now none, abort. 1479 */ 1480 sdev_printk(KERN_ERR, sdev, 1481 "Unexpected response" 1482 " from lun %d while scanning, scan" 1483 " aborted\n", lun); 1484 break; 1485 } 1486 } 1487 } 1488 1489 out_err: 1490 kfree(lun_data); 1491 out: 1492 scsi_device_put(sdev); 1493 if (scsi_device_created(sdev)) 1494 /* 1495 * the sdev we used didn't appear in the report luns scan 1496 */ 1497 __scsi_remove_device(sdev); 1498 return ret; 1499 } 1500 1501 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1502 uint id, uint lun, void *hostdata) 1503 { 1504 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1505 struct device *parent = &shost->shost_gendev; 1506 struct scsi_target *starget; 1507 1508 if (strncmp(scsi_scan_type, "none", 4) == 0) 1509 return ERR_PTR(-ENODEV); 1510 1511 starget = scsi_alloc_target(parent, channel, id); 1512 if (!starget) 1513 return ERR_PTR(-ENOMEM); 1514 scsi_autopm_get_target(starget); 1515 1516 mutex_lock(&shost->scan_mutex); 1517 if (!shost->async_scan) 1518 scsi_complete_async_scans(); 1519 1520 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1521 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1522 scsi_autopm_put_host(shost); 1523 } 1524 mutex_unlock(&shost->scan_mutex); 1525 scsi_autopm_put_target(starget); 1526 scsi_target_reap(starget); 1527 put_device(&starget->dev); 1528 1529 return sdev; 1530 } 1531 EXPORT_SYMBOL(__scsi_add_device); 1532 1533 int scsi_add_device(struct Scsi_Host *host, uint channel, 1534 uint target, uint lun) 1535 { 1536 struct scsi_device *sdev = 1537 __scsi_add_device(host, channel, target, lun, NULL); 1538 if (IS_ERR(sdev)) 1539 return PTR_ERR(sdev); 1540 1541 scsi_device_put(sdev); 1542 return 0; 1543 } 1544 EXPORT_SYMBOL(scsi_add_device); 1545 1546 void scsi_rescan_device(struct device *dev) 1547 { 1548 struct scsi_driver *drv; 1549 1550 if (!dev->driver) 1551 return; 1552 1553 drv = to_scsi_driver(dev->driver); 1554 if (try_module_get(drv->owner)) { 1555 if (drv->rescan) 1556 drv->rescan(dev); 1557 module_put(drv->owner); 1558 } 1559 } 1560 EXPORT_SYMBOL(scsi_rescan_device); 1561 1562 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1563 unsigned int id, unsigned int lun, int rescan) 1564 { 1565 struct Scsi_Host *shost = dev_to_shost(parent); 1566 int bflags = 0; 1567 int res; 1568 struct scsi_target *starget; 1569 1570 if (shost->this_id == id) 1571 /* 1572 * Don't scan the host adapter 1573 */ 1574 return; 1575 1576 starget = scsi_alloc_target(parent, channel, id); 1577 if (!starget) 1578 return; 1579 scsi_autopm_get_target(starget); 1580 1581 if (lun != SCAN_WILD_CARD) { 1582 /* 1583 * Scan for a specific host/chan/id/lun. 1584 */ 1585 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1586 goto out_reap; 1587 } 1588 1589 /* 1590 * Scan LUN 0, if there is some response, scan further. Ideally, we 1591 * would not configure LUN 0 until all LUNs are scanned. 1592 */ 1593 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1594 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1595 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1596 /* 1597 * The REPORT LUN did not scan the target, 1598 * do a sequential scan. 1599 */ 1600 scsi_sequential_lun_scan(starget, bflags, 1601 starget->scsi_level, rescan); 1602 } 1603 1604 out_reap: 1605 scsi_autopm_put_target(starget); 1606 /* now determine if the target has any children at all 1607 * and if not, nuke it */ 1608 scsi_target_reap(starget); 1609 1610 put_device(&starget->dev); 1611 } 1612 1613 /** 1614 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1615 * @parent: host to scan 1616 * @channel: channel to scan 1617 * @id: target id to scan 1618 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1619 * @rescan: passed to LUN scanning routines 1620 * 1621 * Description: 1622 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1623 * and possibly all LUNs on the target id. 1624 * 1625 * First try a REPORT LUN scan, if that does not scan the target, do a 1626 * sequential scan of LUNs on the target id. 1627 **/ 1628 void scsi_scan_target(struct device *parent, unsigned int channel, 1629 unsigned int id, unsigned int lun, int rescan) 1630 { 1631 struct Scsi_Host *shost = dev_to_shost(parent); 1632 1633 if (strncmp(scsi_scan_type, "none", 4) == 0) 1634 return; 1635 1636 mutex_lock(&shost->scan_mutex); 1637 if (!shost->async_scan) 1638 scsi_complete_async_scans(); 1639 1640 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1641 __scsi_scan_target(parent, channel, id, lun, rescan); 1642 scsi_autopm_put_host(shost); 1643 } 1644 mutex_unlock(&shost->scan_mutex); 1645 } 1646 EXPORT_SYMBOL(scsi_scan_target); 1647 1648 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1649 unsigned int id, unsigned int lun, int rescan) 1650 { 1651 uint order_id; 1652 1653 if (id == SCAN_WILD_CARD) 1654 for (id = 0; id < shost->max_id; ++id) { 1655 /* 1656 * XXX adapter drivers when possible (FCP, iSCSI) 1657 * could modify max_id to match the current max, 1658 * not the absolute max. 1659 * 1660 * XXX add a shost id iterator, so for example, 1661 * the FC ID can be the same as a target id 1662 * without a huge overhead of sparse id's. 1663 */ 1664 if (shost->reverse_ordering) 1665 /* 1666 * Scan from high to low id. 1667 */ 1668 order_id = shost->max_id - id - 1; 1669 else 1670 order_id = id; 1671 __scsi_scan_target(&shost->shost_gendev, channel, 1672 order_id, lun, rescan); 1673 } 1674 else 1675 __scsi_scan_target(&shost->shost_gendev, channel, 1676 id, lun, rescan); 1677 } 1678 1679 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1680 unsigned int id, unsigned int lun, int rescan) 1681 { 1682 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1683 "%s: <%u:%u:%u>\n", 1684 __func__, channel, id, lun)); 1685 1686 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1687 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1688 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun))) 1689 return -EINVAL; 1690 1691 mutex_lock(&shost->scan_mutex); 1692 if (!shost->async_scan) 1693 scsi_complete_async_scans(); 1694 1695 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1696 if (channel == SCAN_WILD_CARD) 1697 for (channel = 0; channel <= shost->max_channel; 1698 channel++) 1699 scsi_scan_channel(shost, channel, id, lun, 1700 rescan); 1701 else 1702 scsi_scan_channel(shost, channel, id, lun, rescan); 1703 scsi_autopm_put_host(shost); 1704 } 1705 mutex_unlock(&shost->scan_mutex); 1706 1707 return 0; 1708 } 1709 1710 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1711 { 1712 struct scsi_device *sdev; 1713 shost_for_each_device(sdev, shost) { 1714 if (!scsi_host_scan_allowed(shost) || 1715 scsi_sysfs_add_sdev(sdev) != 0) 1716 __scsi_remove_device(sdev); 1717 } 1718 } 1719 1720 /** 1721 * scsi_prep_async_scan - prepare for an async scan 1722 * @shost: the host which will be scanned 1723 * Returns: a cookie to be passed to scsi_finish_async_scan() 1724 * 1725 * Tells the midlayer this host is going to do an asynchronous scan. 1726 * It reserves the host's position in the scanning list and ensures 1727 * that other asynchronous scans started after this one won't affect the 1728 * ordering of the discovered devices. 1729 */ 1730 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1731 { 1732 struct async_scan_data *data; 1733 unsigned long flags; 1734 1735 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1736 return NULL; 1737 1738 if (shost->async_scan) { 1739 printk("%s called twice for host %d", __func__, 1740 shost->host_no); 1741 dump_stack(); 1742 return NULL; 1743 } 1744 1745 data = kmalloc(sizeof(*data), GFP_KERNEL); 1746 if (!data) 1747 goto err; 1748 data->shost = scsi_host_get(shost); 1749 if (!data->shost) 1750 goto err; 1751 init_completion(&data->prev_finished); 1752 1753 mutex_lock(&shost->scan_mutex); 1754 spin_lock_irqsave(shost->host_lock, flags); 1755 shost->async_scan = 1; 1756 spin_unlock_irqrestore(shost->host_lock, flags); 1757 mutex_unlock(&shost->scan_mutex); 1758 1759 spin_lock(&async_scan_lock); 1760 if (list_empty(&scanning_hosts)) 1761 complete(&data->prev_finished); 1762 list_add_tail(&data->list, &scanning_hosts); 1763 spin_unlock(&async_scan_lock); 1764 1765 return data; 1766 1767 err: 1768 kfree(data); 1769 return NULL; 1770 } 1771 1772 /** 1773 * scsi_finish_async_scan - asynchronous scan has finished 1774 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1775 * 1776 * All the devices currently attached to this host have been found. 1777 * This function announces all the devices it has found to the rest 1778 * of the system. 1779 */ 1780 static void scsi_finish_async_scan(struct async_scan_data *data) 1781 { 1782 struct Scsi_Host *shost; 1783 unsigned long flags; 1784 1785 if (!data) 1786 return; 1787 1788 shost = data->shost; 1789 1790 mutex_lock(&shost->scan_mutex); 1791 1792 if (!shost->async_scan) { 1793 printk("%s called twice for host %d", __func__, 1794 shost->host_no); 1795 dump_stack(); 1796 mutex_unlock(&shost->scan_mutex); 1797 return; 1798 } 1799 1800 wait_for_completion(&data->prev_finished); 1801 1802 scsi_sysfs_add_devices(shost); 1803 1804 spin_lock_irqsave(shost->host_lock, flags); 1805 shost->async_scan = 0; 1806 spin_unlock_irqrestore(shost->host_lock, flags); 1807 1808 mutex_unlock(&shost->scan_mutex); 1809 1810 spin_lock(&async_scan_lock); 1811 list_del(&data->list); 1812 if (!list_empty(&scanning_hosts)) { 1813 struct async_scan_data *next = list_entry(scanning_hosts.next, 1814 struct async_scan_data, list); 1815 complete(&next->prev_finished); 1816 } 1817 spin_unlock(&async_scan_lock); 1818 1819 scsi_host_put(shost); 1820 kfree(data); 1821 } 1822 1823 static void do_scsi_scan_host(struct Scsi_Host *shost) 1824 { 1825 if (shost->hostt->scan_finished) { 1826 unsigned long start = jiffies; 1827 if (shost->hostt->scan_start) 1828 shost->hostt->scan_start(shost); 1829 1830 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1831 msleep(10); 1832 } else { 1833 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1834 SCAN_WILD_CARD, 0); 1835 } 1836 } 1837 1838 static int do_scan_async(void *_data) 1839 { 1840 struct async_scan_data *data = _data; 1841 struct Scsi_Host *shost = data->shost; 1842 1843 do_scsi_scan_host(shost); 1844 scsi_finish_async_scan(data); 1845 scsi_autopm_put_host(shost); 1846 return 0; 1847 } 1848 1849 /** 1850 * scsi_scan_host - scan the given adapter 1851 * @shost: adapter to scan 1852 **/ 1853 void scsi_scan_host(struct Scsi_Host *shost) 1854 { 1855 struct task_struct *p; 1856 struct async_scan_data *data; 1857 1858 if (strncmp(scsi_scan_type, "none", 4) == 0) 1859 return; 1860 if (scsi_autopm_get_host(shost) < 0) 1861 return; 1862 1863 data = scsi_prep_async_scan(shost); 1864 if (!data) { 1865 do_scsi_scan_host(shost); 1866 scsi_autopm_put_host(shost); 1867 return; 1868 } 1869 1870 p = kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no); 1871 if (IS_ERR(p)) 1872 do_scan_async(data); 1873 /* scsi_autopm_put_host(shost) is called in do_scan_async() */ 1874 } 1875 EXPORT_SYMBOL(scsi_scan_host); 1876 1877 void scsi_forget_host(struct Scsi_Host *shost) 1878 { 1879 struct scsi_device *sdev; 1880 unsigned long flags; 1881 1882 restart: 1883 spin_lock_irqsave(shost->host_lock, flags); 1884 list_for_each_entry(sdev, &shost->__devices, siblings) { 1885 if (sdev->sdev_state == SDEV_DEL) 1886 continue; 1887 spin_unlock_irqrestore(shost->host_lock, flags); 1888 __scsi_remove_device(sdev); 1889 goto restart; 1890 } 1891 spin_unlock_irqrestore(shost->host_lock, flags); 1892 } 1893 1894 /** 1895 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself 1896 * @shost: Host that needs a scsi_device 1897 * 1898 * Lock status: None assumed. 1899 * 1900 * Returns: The scsi_device or NULL 1901 * 1902 * Notes: 1903 * Attach a single scsi_device to the Scsi_Host - this should 1904 * be made to look like a "pseudo-device" that points to the 1905 * HA itself. 1906 * 1907 * Note - this device is not accessible from any high-level 1908 * drivers (including generics), which is probably not 1909 * optimal. We can add hooks later to attach. 1910 */ 1911 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1912 { 1913 struct scsi_device *sdev = NULL; 1914 struct scsi_target *starget; 1915 1916 mutex_lock(&shost->scan_mutex); 1917 if (!scsi_host_scan_allowed(shost)) 1918 goto out; 1919 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1920 if (!starget) 1921 goto out; 1922 1923 sdev = scsi_alloc_sdev(starget, 0, NULL); 1924 if (sdev) 1925 sdev->borken = 0; 1926 else 1927 scsi_target_reap(starget); 1928 put_device(&starget->dev); 1929 out: 1930 mutex_unlock(&shost->scan_mutex); 1931 return sdev; 1932 } 1933 EXPORT_SYMBOL(scsi_get_host_dev); 1934 1935 /** 1936 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself 1937 * @sdev: Host device to be freed 1938 * 1939 * Lock status: None assumed. 1940 * 1941 * Returns: Nothing 1942 */ 1943 void scsi_free_host_dev(struct scsi_device *sdev) 1944 { 1945 BUG_ON(sdev->id != sdev->host->this_id); 1946 1947 __scsi_remove_device(sdev); 1948 } 1949 EXPORT_SYMBOL(scsi_free_host_dev); 1950 1951