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 37 #include <scsi/scsi.h> 38 #include <scsi/scsi_cmnd.h> 39 #include <scsi/scsi_device.h> 40 #include <scsi/scsi_driver.h> 41 #include <scsi/scsi_devinfo.h> 42 #include <scsi/scsi_host.h> 43 #include <scsi/scsi_transport.h> 44 #include <scsi/scsi_eh.h> 45 46 #include "scsi_priv.h" 47 #include "scsi_logging.h" 48 49 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \ 50 " SCSI scanning, some SCSI devices might not be configured\n" 51 52 /* 53 * Default timeout 54 */ 55 #define SCSI_TIMEOUT (2*HZ) 56 57 /* 58 * Prefix values for the SCSI id's (stored in sysfs name field) 59 */ 60 #define SCSI_UID_SER_NUM 'S' 61 #define SCSI_UID_UNKNOWN 'Z' 62 63 /* 64 * Return values of some of the scanning functions. 65 * 66 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this 67 * includes allocation or general failures preventing IO from being sent. 68 * 69 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available 70 * on the given LUN. 71 * 72 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a 73 * given LUN. 74 */ 75 #define SCSI_SCAN_NO_RESPONSE 0 76 #define SCSI_SCAN_TARGET_PRESENT 1 77 #define SCSI_SCAN_LUN_PRESENT 2 78 79 static const char *scsi_null_device_strs = "nullnullnullnull"; 80 81 #define MAX_SCSI_LUNS 512 82 83 #ifdef CONFIG_SCSI_MULTI_LUN 84 static unsigned int max_scsi_luns = MAX_SCSI_LUNS; 85 #else 86 static unsigned int max_scsi_luns = 1; 87 #endif 88 89 module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR); 90 MODULE_PARM_DESC(max_luns, 91 "last scsi LUN (should be between 1 and 2^32-1)"); 92 93 #ifdef CONFIG_SCSI_SCAN_ASYNC 94 #define SCSI_SCAN_TYPE_DEFAULT "async" 95 #else 96 #define SCSI_SCAN_TYPE_DEFAULT "sync" 97 #endif 98 99 static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT; 100 101 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO); 102 MODULE_PARM_DESC(scan, "sync, async or none"); 103 104 /* 105 * max_scsi_report_luns: the maximum number of LUNS that will be 106 * returned from the REPORT LUNS command. 8 times this value must 107 * be allocated. In theory this could be up to an 8 byte value, but 108 * in practice, the maximum number of LUNs suppored by any device 109 * is about 16k. 110 */ 111 static unsigned int max_scsi_report_luns = 511; 112 113 module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR); 114 MODULE_PARM_DESC(max_report_luns, 115 "REPORT LUNS maximum number of LUNS received (should be" 116 " between 1 and 16384)"); 117 118 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3; 119 120 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR); 121 MODULE_PARM_DESC(inq_timeout, 122 "Timeout (in seconds) waiting for devices to answer INQUIRY." 123 " Default is 5. Some non-compliant devices need more."); 124 125 /* This lock protects only this list */ 126 static DEFINE_SPINLOCK(async_scan_lock); 127 static LIST_HEAD(scanning_hosts); 128 129 struct async_scan_data { 130 struct list_head list; 131 struct Scsi_Host *shost; 132 struct completion prev_finished; 133 }; 134 135 /** 136 * scsi_complete_async_scans - Wait for asynchronous scans to complete 137 * 138 * When this function returns, any host which started scanning before 139 * this function was called will have finished its scan. Hosts which 140 * started scanning after this function was called may or may not have 141 * finished. 142 */ 143 int scsi_complete_async_scans(void) 144 { 145 struct async_scan_data *data; 146 147 do { 148 if (list_empty(&scanning_hosts)) 149 return 0; 150 /* If we can't get memory immediately, that's OK. Just 151 * sleep a little. Even if we never get memory, the async 152 * scans will finish eventually. 153 */ 154 data = kmalloc(sizeof(*data), GFP_KERNEL); 155 if (!data) 156 msleep(1); 157 } while (!data); 158 159 data->shost = NULL; 160 init_completion(&data->prev_finished); 161 162 spin_lock(&async_scan_lock); 163 /* Check that there's still somebody else on the list */ 164 if (list_empty(&scanning_hosts)) 165 goto done; 166 list_add_tail(&data->list, &scanning_hosts); 167 spin_unlock(&async_scan_lock); 168 169 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n"); 170 wait_for_completion(&data->prev_finished); 171 172 spin_lock(&async_scan_lock); 173 list_del(&data->list); 174 if (!list_empty(&scanning_hosts)) { 175 struct async_scan_data *next = list_entry(scanning_hosts.next, 176 struct async_scan_data, list); 177 complete(&next->prev_finished); 178 } 179 done: 180 spin_unlock(&async_scan_lock); 181 182 kfree(data); 183 /* Synchronize async operations globally */ 184 async_synchronize_full(); 185 return 0; 186 } 187 188 /* Only exported for the benefit of scsi_wait_scan */ 189 EXPORT_SYMBOL_GPL(scsi_complete_async_scans); 190 191 #ifndef MODULE 192 /* 193 * For async scanning we need to wait for all the scans to complete before 194 * trying to mount the root fs. Otherwise non-modular drivers may not be ready 195 * yet. 196 */ 197 late_initcall(scsi_complete_async_scans); 198 #endif 199 200 /** 201 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 202 * @sdev: scsi device to send command to 203 * @result: area to store the result of the MODE SENSE 204 * 205 * Description: 206 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 207 * Called for BLIST_KEY devices. 208 **/ 209 static void scsi_unlock_floptical(struct scsi_device *sdev, 210 unsigned char *result) 211 { 212 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 213 214 printk(KERN_NOTICE "scsi: unlocking floptical drive\n"); 215 scsi_cmd[0] = MODE_SENSE; 216 scsi_cmd[1] = 0; 217 scsi_cmd[2] = 0x2e; 218 scsi_cmd[3] = 0; 219 scsi_cmd[4] = 0x2a; /* size */ 220 scsi_cmd[5] = 0; 221 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 222 SCSI_TIMEOUT, 3, NULL); 223 } 224 225 /** 226 * scsi_alloc_sdev - allocate and setup a scsi_Device 227 * @starget: which target to allocate a &scsi_device for 228 * @lun: which lun 229 * @hostdata: usually NULL and set by ->slave_alloc instead 230 * 231 * Description: 232 * Allocate, initialize for io, and return a pointer to a scsi_Device. 233 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 234 * adds scsi_Device to the appropriate list. 235 * 236 * Return value: 237 * scsi_Device pointer, or NULL on failure. 238 **/ 239 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 240 unsigned int lun, void *hostdata) 241 { 242 struct scsi_device *sdev; 243 int display_failure_msg = 1, ret; 244 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 245 extern void scsi_evt_thread(struct work_struct *work); 246 247 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 248 GFP_ATOMIC); 249 if (!sdev) 250 goto out; 251 252 sdev->vendor = scsi_null_device_strs; 253 sdev->model = scsi_null_device_strs; 254 sdev->rev = scsi_null_device_strs; 255 sdev->host = shost; 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 transport_destroy_device(&sdev->sdev_gendev); 321 put_device(&sdev->sdev_gendev); 322 out: 323 if (display_failure_msg) 324 printk(ALLOC_FAILURE_MSG, __func__); 325 return NULL; 326 } 327 328 static void scsi_target_destroy(struct scsi_target *starget) 329 { 330 struct device *dev = &starget->dev; 331 struct Scsi_Host *shost = dev_to_shost(dev->parent); 332 unsigned long flags; 333 334 transport_destroy_device(dev); 335 spin_lock_irqsave(shost->host_lock, flags); 336 if (shost->hostt->target_destroy) 337 shost->hostt->target_destroy(starget); 338 list_del_init(&starget->siblings); 339 spin_unlock_irqrestore(shost->host_lock, flags); 340 put_device(dev); 341 } 342 343 static void scsi_target_dev_release(struct device *dev) 344 { 345 struct device *parent = dev->parent; 346 struct scsi_target *starget = to_scsi_target(dev); 347 348 kfree(starget); 349 put_device(parent); 350 } 351 352 static struct device_type scsi_target_type = { 353 .name = "scsi_target", 354 .release = scsi_target_dev_release, 355 }; 356 357 int scsi_is_target_device(const struct device *dev) 358 { 359 return dev->type == &scsi_target_type; 360 } 361 EXPORT_SYMBOL(scsi_is_target_device); 362 363 static struct scsi_target *__scsi_find_target(struct device *parent, 364 int channel, uint id) 365 { 366 struct scsi_target *starget, *found_starget = NULL; 367 struct Scsi_Host *shost = dev_to_shost(parent); 368 /* 369 * Search for an existing target for this sdev. 370 */ 371 list_for_each_entry(starget, &shost->__targets, siblings) { 372 if (starget->id == id && 373 starget->channel == channel) { 374 found_starget = starget; 375 break; 376 } 377 } 378 if (found_starget) 379 get_device(&found_starget->dev); 380 381 return found_starget; 382 } 383 384 /** 385 * scsi_alloc_target - allocate a new or find an existing target 386 * @parent: parent of the target (need not be a scsi host) 387 * @channel: target channel number (zero if no channels) 388 * @id: target id number 389 * 390 * Return an existing target if one exists, provided it hasn't already 391 * gone into STARGET_DEL state, otherwise allocate a new target. 392 * 393 * The target is returned with an incremented reference, so the caller 394 * is responsible for both reaping and doing a last put 395 */ 396 static struct scsi_target *scsi_alloc_target(struct device *parent, 397 int channel, uint id) 398 { 399 struct Scsi_Host *shost = dev_to_shost(parent); 400 struct device *dev = NULL; 401 unsigned long flags; 402 const int size = sizeof(struct scsi_target) 403 + shost->transportt->target_size; 404 struct scsi_target *starget; 405 struct scsi_target *found_target; 406 int error; 407 408 starget = kzalloc(size, GFP_KERNEL); 409 if (!starget) { 410 printk(KERN_ERR "%s: allocation failure\n", __func__); 411 return NULL; 412 } 413 dev = &starget->dev; 414 device_initialize(dev); 415 starget->reap_ref = 1; 416 dev->parent = get_device(parent); 417 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 418 #ifndef CONFIG_SYSFS_DEPRECATED 419 dev->bus = &scsi_bus_type; 420 #endif 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 retry: 430 spin_lock_irqsave(shost->host_lock, flags); 431 432 found_target = __scsi_find_target(parent, channel, id); 433 if (found_target) 434 goto found; 435 436 list_add_tail(&starget->siblings, &shost->__targets); 437 spin_unlock_irqrestore(shost->host_lock, flags); 438 /* allocate and add */ 439 transport_setup_device(dev); 440 if (shost->hostt->target_alloc) { 441 error = shost->hostt->target_alloc(starget); 442 443 if(error) { 444 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 445 /* don't want scsi_target_reap to do the final 446 * put because it will be under the host lock */ 447 scsi_target_destroy(starget); 448 return NULL; 449 } 450 } 451 get_device(dev); 452 453 return starget; 454 455 found: 456 found_target->reap_ref++; 457 spin_unlock_irqrestore(shost->host_lock, flags); 458 if (found_target->state != STARGET_DEL) { 459 put_device(parent); 460 kfree(starget); 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; 494 495 spin_lock_irqsave(shost->host_lock, flags); 496 state = starget->state; 497 empty = --starget->reap_ref == 0 && 498 list_empty(&starget->devices) ? 1 : 0; 499 spin_unlock_irqrestore(shost->host_lock, flags); 500 501 if (!empty) 502 return; 503 504 BUG_ON(state == STARGET_DEL); 505 starget->state = STARGET_DEL; 506 if (state == STARGET_CREATED) 507 scsi_target_destroy(starget); 508 else 509 execute_in_process_context(scsi_target_reap_usercontext, 510 &starget->ew); 511 } 512 513 /** 514 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string 515 * @s: INQUIRY result string to sanitize 516 * @len: length of the string 517 * 518 * Description: 519 * The SCSI spec says that INQUIRY vendor, product, and revision 520 * strings must consist entirely of graphic ASCII characters, 521 * padded on the right with spaces. Since not all devices obey 522 * this rule, we will replace non-graphic or non-ASCII characters 523 * with spaces. Exception: a NUL character is interpreted as a 524 * string terminator, so all the following characters are set to 525 * spaces. 526 **/ 527 static void sanitize_inquiry_string(unsigned char *s, int len) 528 { 529 int terminated = 0; 530 531 for (; len > 0; (--len, ++s)) { 532 if (*s == 0) 533 terminated = 1; 534 if (terminated || *s < 0x20 || *s > 0x7e) 535 *s = ' '; 536 } 537 } 538 539 /** 540 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 541 * @sdev: scsi_device to probe 542 * @inq_result: area to store the INQUIRY result 543 * @result_len: len of inq_result 544 * @bflags: store any bflags found here 545 * 546 * Description: 547 * Probe the lun associated with @req using a standard SCSI INQUIRY; 548 * 549 * If the INQUIRY is successful, zero is returned and the 550 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 551 * are copied to the scsi_device any flags value is stored in *@bflags. 552 **/ 553 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 554 int result_len, int *bflags) 555 { 556 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 557 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 558 int response_len = 0; 559 int pass, count, result; 560 struct scsi_sense_hdr sshdr; 561 562 *bflags = 0; 563 564 /* Perform up to 3 passes. The first pass uses a conservative 565 * transfer length of 36 unless sdev->inquiry_len specifies a 566 * different value. */ 567 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 568 try_inquiry_len = first_inquiry_len; 569 pass = 1; 570 571 next_pass: 572 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 573 "scsi scan: INQUIRY pass %d length %d\n", 574 pass, try_inquiry_len)); 575 576 /* Each pass gets up to three chances to ignore Unit Attention */ 577 for (count = 0; count < 3; ++count) { 578 int resid; 579 580 memset(scsi_cmd, 0, 6); 581 scsi_cmd[0] = INQUIRY; 582 scsi_cmd[4] = (unsigned char) try_inquiry_len; 583 584 memset(inq_result, 0, try_inquiry_len); 585 586 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 587 inq_result, try_inquiry_len, &sshdr, 588 HZ / 2 + HZ * scsi_inq_timeout, 3, 589 &resid); 590 591 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s " 592 "with code 0x%x\n", 593 result ? "failed" : "successful", result)); 594 595 if (result) { 596 /* 597 * not-ready to ready transition [asc/ascq=0x28/0x0] 598 * or power-on, reset [asc/ascq=0x29/0x0], continue. 599 * INQUIRY should not yield UNIT_ATTENTION 600 * but many buggy devices do so anyway. 601 */ 602 if ((driver_byte(result) & DRIVER_SENSE) && 603 scsi_sense_valid(&sshdr)) { 604 if ((sshdr.sense_key == UNIT_ATTENTION) && 605 ((sshdr.asc == 0x28) || 606 (sshdr.asc == 0x29)) && 607 (sshdr.ascq == 0)) 608 continue; 609 } 610 } else { 611 /* 612 * if nothing was transferred, we try 613 * again. It's a workaround for some USB 614 * devices. 615 */ 616 if (resid == try_inquiry_len) 617 continue; 618 } 619 break; 620 } 621 622 if (result == 0) { 623 sanitize_inquiry_string(&inq_result[8], 8); 624 sanitize_inquiry_string(&inq_result[16], 16); 625 sanitize_inquiry_string(&inq_result[32], 4); 626 627 response_len = inq_result[4] + 5; 628 if (response_len > 255) 629 response_len = first_inquiry_len; /* sanity */ 630 631 /* 632 * Get any flags for this device. 633 * 634 * XXX add a bflags to scsi_device, and replace the 635 * corresponding bit fields in scsi_device, so bflags 636 * need not be passed as an argument. 637 */ 638 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 639 &inq_result[16]); 640 641 /* When the first pass succeeds we gain information about 642 * what larger transfer lengths might work. */ 643 if (pass == 1) { 644 if (BLIST_INQUIRY_36 & *bflags) 645 next_inquiry_len = 36; 646 else if (BLIST_INQUIRY_58 & *bflags) 647 next_inquiry_len = 58; 648 else if (sdev->inquiry_len) 649 next_inquiry_len = sdev->inquiry_len; 650 else 651 next_inquiry_len = response_len; 652 653 /* If more data is available perform the second pass */ 654 if (next_inquiry_len > try_inquiry_len) { 655 try_inquiry_len = next_inquiry_len; 656 pass = 2; 657 goto next_pass; 658 } 659 } 660 661 } else if (pass == 2) { 662 printk(KERN_INFO "scsi scan: %d byte inquiry failed. " 663 "Consider BLIST_INQUIRY_36 for this device\n", 664 try_inquiry_len); 665 666 /* If this pass failed, the third pass goes back and transfers 667 * the same amount as we successfully got in the first pass. */ 668 try_inquiry_len = first_inquiry_len; 669 pass = 3; 670 goto next_pass; 671 } 672 673 /* If the last transfer attempt got an error, assume the 674 * peripheral doesn't exist or is dead. */ 675 if (result) 676 return -EIO; 677 678 /* Don't report any more data than the device says is valid */ 679 sdev->inquiry_len = min(try_inquiry_len, response_len); 680 681 /* 682 * XXX Abort if the response length is less than 36? If less than 683 * 32, the lookup of the device flags (above) could be invalid, 684 * and it would be possible to take an incorrect action - we do 685 * not want to hang because of a short INQUIRY. On the flip side, 686 * if the device is spun down or becoming ready (and so it gives a 687 * short INQUIRY), an abort here prevents any further use of the 688 * device, including spin up. 689 * 690 * On the whole, the best approach seems to be to assume the first 691 * 36 bytes are valid no matter what the device says. That's 692 * better than copying < 36 bytes to the inquiry-result buffer 693 * and displaying garbage for the Vendor, Product, or Revision 694 * strings. 695 */ 696 if (sdev->inquiry_len < 36) { 697 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d)," 698 " using 36\n", sdev->inquiry_len); 699 sdev->inquiry_len = 36; 700 } 701 702 /* 703 * Related to the above issue: 704 * 705 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 706 * and if not ready, sent a START_STOP to start (maybe spin up) and 707 * then send the INQUIRY again, since the INQUIRY can change after 708 * a device is initialized. 709 * 710 * Ideally, start a device if explicitly asked to do so. This 711 * assumes that a device is spun up on power on, spun down on 712 * request, and then spun up on request. 713 */ 714 715 /* 716 * The scanning code needs to know the scsi_level, even if no 717 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 718 * non-zero LUNs can be scanned. 719 */ 720 sdev->scsi_level = inq_result[2] & 0x07; 721 if (sdev->scsi_level >= 2 || 722 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 723 sdev->scsi_level++; 724 sdev->sdev_target->scsi_level = sdev->scsi_level; 725 726 return 0; 727 } 728 729 /** 730 * scsi_add_lun - allocate and fully initialze a scsi_device 731 * @sdev: holds information to be stored in the new scsi_device 732 * @inq_result: holds the result of a previous INQUIRY to the LUN 733 * @bflags: black/white list flag 734 * @async: 1 if this device is being scanned asynchronously 735 * 736 * Description: 737 * Initialize the scsi_device @sdev. Optionally set fields based 738 * on values in *@bflags. 739 * 740 * Return: 741 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 742 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 743 **/ 744 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 745 int *bflags, int async) 746 { 747 int ret; 748 749 /* 750 * XXX do not save the inquiry, since it can change underneath us, 751 * save just vendor/model/rev. 752 * 753 * Rather than save it and have an ioctl that retrieves the saved 754 * value, have an ioctl that executes the same INQUIRY code used 755 * in scsi_probe_lun, let user level programs doing INQUIRY 756 * scanning run at their own risk, or supply a user level program 757 * that can correctly scan. 758 */ 759 760 /* 761 * Copy at least 36 bytes of INQUIRY data, so that we don't 762 * dereference unallocated memory when accessing the Vendor, 763 * Product, and Revision strings. Badly behaved devices may set 764 * the INQUIRY Additional Length byte to a small value, indicating 765 * these strings are invalid, but often they contain plausible data 766 * nonetheless. It doesn't matter if the device sent < 36 bytes 767 * total, since scsi_probe_lun() initializes inq_result with 0s. 768 */ 769 sdev->inquiry = kmemdup(inq_result, 770 max_t(size_t, sdev->inquiry_len, 36), 771 GFP_ATOMIC); 772 if (sdev->inquiry == NULL) 773 return SCSI_SCAN_NO_RESPONSE; 774 775 sdev->vendor = (char *) (sdev->inquiry + 8); 776 sdev->model = (char *) (sdev->inquiry + 16); 777 sdev->rev = (char *) (sdev->inquiry + 32); 778 779 if (*bflags & BLIST_ISROM) { 780 sdev->type = TYPE_ROM; 781 sdev->removable = 1; 782 } else { 783 sdev->type = (inq_result[0] & 0x1f); 784 sdev->removable = (inq_result[1] & 0x80) >> 7; 785 } 786 787 switch (sdev->type) { 788 case TYPE_RBC: 789 case TYPE_TAPE: 790 case TYPE_DISK: 791 case TYPE_PRINTER: 792 case TYPE_MOD: 793 case TYPE_PROCESSOR: 794 case TYPE_SCANNER: 795 case TYPE_MEDIUM_CHANGER: 796 case TYPE_ENCLOSURE: 797 case TYPE_COMM: 798 case TYPE_RAID: 799 sdev->writeable = 1; 800 break; 801 case TYPE_ROM: 802 case TYPE_WORM: 803 sdev->writeable = 0; 804 break; 805 default: 806 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type); 807 } 808 809 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 810 /* RBC and MMC devices can return SCSI-3 compliance and yet 811 * still not support REPORT LUNS, so make them act as 812 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 813 * specifically set */ 814 if ((*bflags & BLIST_REPORTLUN2) == 0) 815 *bflags |= BLIST_NOREPORTLUN; 816 } 817 818 /* 819 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 820 * spec says: The device server is capable of supporting the 821 * specified peripheral device type on this logical unit. However, 822 * the physical device is not currently connected to this logical 823 * unit. 824 * 825 * The above is vague, as it implies that we could treat 001 and 826 * 011 the same. Stay compatible with previous code, and create a 827 * scsi_device for a PQ of 1 828 * 829 * Don't set the device offline here; rather let the upper 830 * level drivers eval the PQ to decide whether they should 831 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 832 */ 833 834 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 835 sdev->lockable = sdev->removable; 836 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 837 838 if (sdev->scsi_level >= SCSI_3 || 839 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 840 sdev->ppr = 1; 841 if (inq_result[7] & 0x60) 842 sdev->wdtr = 1; 843 if (inq_result[7] & 0x10) 844 sdev->sdtr = 1; 845 846 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 847 "ANSI: %d%s\n", scsi_device_type(sdev->type), 848 sdev->vendor, sdev->model, sdev->rev, 849 sdev->inq_periph_qual, inq_result[2] & 0x07, 850 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 851 852 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 853 !(*bflags & BLIST_NOTQ)) 854 sdev->tagged_supported = 1; 855 856 /* 857 * Some devices (Texel CD ROM drives) have handshaking problems 858 * when used with the Seagate controllers. borken is initialized 859 * to 1, and then set it to 0 here. 860 */ 861 if ((*bflags & BLIST_BORKEN) == 0) 862 sdev->borken = 0; 863 864 if (*bflags & BLIST_NO_ULD_ATTACH) 865 sdev->no_uld_attach = 1; 866 867 /* 868 * Apparently some really broken devices (contrary to the SCSI 869 * standards) need to be selected without asserting ATN 870 */ 871 if (*bflags & BLIST_SELECT_NO_ATN) 872 sdev->select_no_atn = 1; 873 874 /* 875 * Maximum 512 sector transfer length 876 * broken RA4x00 Compaq Disk Array 877 */ 878 if (*bflags & BLIST_MAX_512) 879 blk_queue_max_sectors(sdev->request_queue, 512); 880 881 /* 882 * Some devices may not want to have a start command automatically 883 * issued when a device is added. 884 */ 885 if (*bflags & BLIST_NOSTARTONADD) 886 sdev->no_start_on_add = 1; 887 888 if (*bflags & BLIST_SINGLELUN) 889 scsi_target(sdev)->single_lun = 1; 890 891 sdev->use_10_for_rw = 1; 892 893 if (*bflags & BLIST_MS_SKIP_PAGE_08) 894 sdev->skip_ms_page_8 = 1; 895 896 if (*bflags & BLIST_MS_SKIP_PAGE_3F) 897 sdev->skip_ms_page_3f = 1; 898 899 if (*bflags & BLIST_USE_10_BYTE_MS) 900 sdev->use_10_for_ms = 1; 901 902 /* set the device running here so that slave configure 903 * may do I/O */ 904 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 905 if (ret) { 906 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 907 908 if (ret) { 909 sdev_printk(KERN_ERR, sdev, 910 "in wrong state %s to complete scan\n", 911 scsi_device_state_name(sdev->sdev_state)); 912 return SCSI_SCAN_NO_RESPONSE; 913 } 914 } 915 916 if (*bflags & BLIST_MS_192_BYTES_FOR_3F) 917 sdev->use_192_bytes_for_3f = 1; 918 919 if (*bflags & BLIST_NOT_LOCKABLE) 920 sdev->lockable = 0; 921 922 if (*bflags & BLIST_RETRY_HWERROR) 923 sdev->retry_hwerror = 1; 924 925 transport_configure_device(&sdev->sdev_gendev); 926 927 if (sdev->host->hostt->slave_configure) { 928 ret = sdev->host->hostt->slave_configure(sdev); 929 if (ret) { 930 /* 931 * if LLDD reports slave not present, don't clutter 932 * console with alloc failure messages 933 */ 934 if (ret != -ENXIO) { 935 sdev_printk(KERN_ERR, sdev, 936 "failed to configure device\n"); 937 } 938 return SCSI_SCAN_NO_RESPONSE; 939 } 940 } 941 942 /* 943 * Ok, the device is now all set up, we can 944 * register it and tell the rest of the kernel 945 * about it. 946 */ 947 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 948 return SCSI_SCAN_NO_RESPONSE; 949 950 return SCSI_SCAN_LUN_PRESENT; 951 } 952 953 static inline void scsi_destroy_sdev(struct scsi_device *sdev) 954 { 955 scsi_device_set_state(sdev, SDEV_DEL); 956 if (sdev->host->hostt->slave_destroy) 957 sdev->host->hostt->slave_destroy(sdev); 958 transport_destroy_device(&sdev->sdev_gendev); 959 put_device(&sdev->sdev_gendev); 960 } 961 962 #ifdef CONFIG_SCSI_LOGGING 963 /** 964 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 965 * @buf: Output buffer with at least end-first+1 bytes of space 966 * @inq: Inquiry buffer (input) 967 * @first: Offset of string into inq 968 * @end: Index after last character in inq 969 */ 970 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 971 unsigned first, unsigned end) 972 { 973 unsigned term = 0, idx; 974 975 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 976 if (inq[idx+first] > ' ') { 977 buf[idx] = inq[idx+first]; 978 term = idx+1; 979 } else { 980 buf[idx] = ' '; 981 } 982 } 983 buf[term] = 0; 984 return buf; 985 } 986 #endif 987 988 /** 989 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 990 * @starget: pointer to target device structure 991 * @lun: LUN of target device 992 * @bflagsp: store bflags here if not NULL 993 * @sdevp: probe the LUN corresponding to this scsi_device 994 * @rescan: if nonzero skip some code only needed on first scan 995 * @hostdata: passed to scsi_alloc_sdev() 996 * 997 * Description: 998 * Call scsi_probe_lun, if a LUN with an attached device is found, 999 * allocate and set it up by calling scsi_add_lun. 1000 * 1001 * Return: 1002 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1003 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1004 * attached at the LUN 1005 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1006 **/ 1007 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1008 uint lun, int *bflagsp, 1009 struct scsi_device **sdevp, int rescan, 1010 void *hostdata) 1011 { 1012 struct scsi_device *sdev; 1013 unsigned char *result; 1014 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1015 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1016 1017 /* 1018 * The rescan flag is used as an optimization, the first scan of a 1019 * host adapter calls into here with rescan == 0. 1020 */ 1021 sdev = scsi_device_lookup_by_target(starget, lun); 1022 if (sdev) { 1023 if (rescan || !scsi_device_created(sdev)) { 1024 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1025 "scsi scan: device exists on %s\n", 1026 dev_name(&sdev->sdev_gendev))); 1027 if (sdevp) 1028 *sdevp = sdev; 1029 else 1030 scsi_device_put(sdev); 1031 1032 if (bflagsp) 1033 *bflagsp = scsi_get_device_flags(sdev, 1034 sdev->vendor, 1035 sdev->model); 1036 return SCSI_SCAN_LUN_PRESENT; 1037 } 1038 scsi_device_put(sdev); 1039 } else 1040 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1041 if (!sdev) 1042 goto out; 1043 1044 result = kmalloc(result_len, GFP_ATOMIC | 1045 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1046 if (!result) 1047 goto out_free_sdev; 1048 1049 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1050 goto out_free_result; 1051 1052 if (bflagsp) 1053 *bflagsp = bflags; 1054 /* 1055 * result contains valid SCSI INQUIRY data. 1056 */ 1057 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) { 1058 /* 1059 * For a Peripheral qualifier 3 (011b), the SCSI 1060 * spec says: The device server is not capable of 1061 * supporting a physical device on this logical 1062 * unit. 1063 * 1064 * For disks, this implies that there is no 1065 * logical disk configured at sdev->lun, but there 1066 * is a target id responding. 1067 */ 1068 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1069 " peripheral qualifier of 3, device not" 1070 " added\n")) 1071 if (lun == 0) { 1072 SCSI_LOG_SCAN_BUS(1, { 1073 unsigned char vend[9]; 1074 unsigned char mod[17]; 1075 1076 sdev_printk(KERN_INFO, sdev, 1077 "scsi scan: consider passing scsi_mod." 1078 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1079 scsi_inq_str(vend, result, 8, 16), 1080 scsi_inq_str(mod, result, 16, 32)); 1081 }); 1082 1083 } 1084 1085 res = SCSI_SCAN_TARGET_PRESENT; 1086 goto out_free_result; 1087 } 1088 1089 /* 1090 * Some targets may set slight variations of PQ and PDT to signal 1091 * that no LUN is present, so don't add sdev in these cases. 1092 * Two specific examples are: 1093 * 1) NetApp targets: return PQ=1, PDT=0x1f 1094 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1095 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1096 * 1097 * References: 1098 * 1) SCSI SPC-3, pp. 145-146 1099 * PQ=1: "A peripheral device having the specified peripheral 1100 * device type is not connected to this logical unit. However, the 1101 * device server is capable of supporting the specified peripheral 1102 * device type on this logical unit." 1103 * PDT=0x1f: "Unknown or no device type" 1104 * 2) USB UFI 1.0, p. 20 1105 * PDT=00h Direct-access device (floppy) 1106 * PDT=1Fh none (no FDD connected to the requested logical unit) 1107 */ 1108 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1109 (result[0] & 0x1f) == 0x1f && 1110 !scsi_is_wlun(lun)) { 1111 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1112 "scsi scan: peripheral device type" 1113 " of 31, no device added\n")); 1114 res = SCSI_SCAN_TARGET_PRESENT; 1115 goto out_free_result; 1116 } 1117 1118 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1119 if (res == SCSI_SCAN_LUN_PRESENT) { 1120 if (bflags & BLIST_KEY) { 1121 sdev->lockable = 0; 1122 scsi_unlock_floptical(sdev, result); 1123 } 1124 } 1125 1126 out_free_result: 1127 kfree(result); 1128 out_free_sdev: 1129 if (res == SCSI_SCAN_LUN_PRESENT) { 1130 if (sdevp) { 1131 if (scsi_device_get(sdev) == 0) { 1132 *sdevp = sdev; 1133 } else { 1134 __scsi_remove_device(sdev); 1135 res = SCSI_SCAN_NO_RESPONSE; 1136 } 1137 } 1138 } else 1139 scsi_destroy_sdev(sdev); 1140 out: 1141 return res; 1142 } 1143 1144 /** 1145 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1146 * @starget: pointer to target structure to scan 1147 * @bflags: black/white list flag for LUN 0 1148 * @scsi_level: Which version of the standard does this device adhere to 1149 * @rescan: passed to scsi_probe_add_lun() 1150 * 1151 * Description: 1152 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1153 * scanned) to some maximum lun until a LUN is found with no device 1154 * attached. Use the bflags to figure out any oddities. 1155 * 1156 * Modifies sdevscan->lun. 1157 **/ 1158 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1159 int bflags, int scsi_level, int rescan) 1160 { 1161 unsigned int sparse_lun, lun, max_dev_lun; 1162 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1163 1164 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of" 1165 "%s\n", dev_name(&starget->dev))); 1166 1167 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1168 /* 1169 * If this device is known to support sparse multiple units, 1170 * override the other settings, and scan all of them. Normally, 1171 * SCSI-3 devices should be scanned via the REPORT LUNS. 1172 */ 1173 if (bflags & BLIST_SPARSELUN) { 1174 max_dev_lun = shost->max_lun; 1175 sparse_lun = 1; 1176 } else 1177 sparse_lun = 0; 1178 1179 /* 1180 * If less than SCSI_1_CSS, and no special lun scaning, stop 1181 * scanning; this matches 2.4 behaviour, but could just be a bug 1182 * (to continue scanning a SCSI_1_CSS device). 1183 * 1184 * This test is broken. We might not have any device on lun0 for 1185 * a sparselun device, and if that's the case then how would we 1186 * know the real scsi_level, eh? It might make sense to just not 1187 * scan any SCSI_1 device for non-0 luns, but that check would best 1188 * go into scsi_alloc_sdev() and just have it return null when asked 1189 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1190 * 1191 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1192 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1193 == 0)) 1194 return; 1195 */ 1196 /* 1197 * If this device is known to support multiple units, override 1198 * the other settings, and scan all of them. 1199 */ 1200 if (bflags & BLIST_FORCELUN) 1201 max_dev_lun = shost->max_lun; 1202 /* 1203 * REGAL CDC-4X: avoid hang after LUN 4 1204 */ 1205 if (bflags & BLIST_MAX5LUN) 1206 max_dev_lun = min(5U, max_dev_lun); 1207 /* 1208 * Do not scan SCSI-2 or lower device past LUN 7, unless 1209 * BLIST_LARGELUN. 1210 */ 1211 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1212 max_dev_lun = min(8U, max_dev_lun); 1213 1214 /* 1215 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1216 * until we reach the max, or no LUN is found and we are not 1217 * sparse_lun. 1218 */ 1219 for (lun = 1; lun < max_dev_lun; ++lun) 1220 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1221 NULL) != SCSI_SCAN_LUN_PRESENT) && 1222 !sparse_lun) 1223 return; 1224 } 1225 1226 /** 1227 * scsilun_to_int: convert a scsi_lun to an int 1228 * @scsilun: struct scsi_lun to be converted. 1229 * 1230 * Description: 1231 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered 1232 * integer, and return the result. The caller must check for 1233 * truncation before using this function. 1234 * 1235 * Notes: 1236 * The struct scsi_lun is assumed to be four levels, with each level 1237 * effectively containing a SCSI byte-ordered (big endian) short; the 1238 * addressing bits of each level are ignored (the highest two bits). 1239 * For a description of the LUN format, post SCSI-3 see the SCSI 1240 * Architecture Model, for SCSI-3 see the SCSI Controller Commands. 1241 * 1242 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns 1243 * the integer: 0x0b030a04 1244 **/ 1245 int scsilun_to_int(struct scsi_lun *scsilun) 1246 { 1247 int i; 1248 unsigned int lun; 1249 1250 lun = 0; 1251 for (i = 0; i < sizeof(lun); i += 2) 1252 lun = lun | (((scsilun->scsi_lun[i] << 8) | 1253 scsilun->scsi_lun[i + 1]) << (i * 8)); 1254 return lun; 1255 } 1256 EXPORT_SYMBOL(scsilun_to_int); 1257 1258 /** 1259 * int_to_scsilun: reverts an int into a scsi_lun 1260 * @lun: integer to be reverted 1261 * @scsilun: struct scsi_lun to be set. 1262 * 1263 * Description: 1264 * Reverts the functionality of the scsilun_to_int, which packed 1265 * an 8-byte lun value into an int. This routine unpacks the int 1266 * back into the lun value. 1267 * Note: the scsilun_to_int() routine does not truly handle all 1268 * 8bytes of the lun value. This functions restores only as much 1269 * as was set by the routine. 1270 * 1271 * Notes: 1272 * Given an integer : 0x0b030a04, this function returns a 1273 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00 1274 * 1275 **/ 1276 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun) 1277 { 1278 int i; 1279 1280 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun)); 1281 1282 for (i = 0; i < sizeof(lun); i += 2) { 1283 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF; 1284 scsilun->scsi_lun[i+1] = lun & 0xFF; 1285 lun = lun >> 16; 1286 } 1287 } 1288 EXPORT_SYMBOL(int_to_scsilun); 1289 1290 /** 1291 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1292 * @starget: which target 1293 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1294 * @rescan: nonzero if we can skip code only needed on first scan 1295 * 1296 * Description: 1297 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1298 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1299 * 1300 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1301 * LUNs even if it's older than SCSI-3. 1302 * If BLIST_NOREPORTLUN is set, return 1 always. 1303 * If BLIST_NOLUN is set, return 0 always. 1304 * 1305 * Return: 1306 * 0: scan completed (or no memory, so further scanning is futile) 1307 * 1: could not scan with REPORT LUN 1308 **/ 1309 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, 1310 int rescan) 1311 { 1312 char devname[64]; 1313 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1314 unsigned int length; 1315 unsigned int lun; 1316 unsigned int num_luns; 1317 unsigned int retries; 1318 int result; 1319 struct scsi_lun *lunp, *lun_data; 1320 u8 *data; 1321 struct scsi_sense_hdr sshdr; 1322 struct scsi_device *sdev; 1323 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1324 int ret = 0; 1325 1326 /* 1327 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1328 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1329 * support more than 8 LUNs. 1330 */ 1331 if (bflags & BLIST_NOREPORTLUN) 1332 return 1; 1333 if (starget->scsi_level < SCSI_2 && 1334 starget->scsi_level != SCSI_UNKNOWN) 1335 return 1; 1336 if (starget->scsi_level < SCSI_3 && 1337 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1338 return 1; 1339 if (bflags & BLIST_NOLUN) 1340 return 0; 1341 1342 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1343 sdev = scsi_alloc_sdev(starget, 0, NULL); 1344 if (!sdev) 1345 return 0; 1346 if (scsi_device_get(sdev)) 1347 return 0; 1348 } 1349 1350 sprintf(devname, "host %d channel %d id %d", 1351 shost->host_no, sdev->channel, sdev->id); 1352 1353 /* 1354 * Allocate enough to hold the header (the same size as one scsi_lun) 1355 * plus the max number of luns we are requesting. 1356 * 1357 * Reallocating and trying again (with the exact amount we need) 1358 * would be nice, but then we need to somehow limit the size 1359 * allocated based on the available memory and the limits of 1360 * kmalloc - we don't want a kmalloc() failure of a huge value to 1361 * prevent us from finding any LUNs on this target. 1362 */ 1363 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun); 1364 lun_data = kmalloc(length, GFP_ATOMIC | 1365 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1366 if (!lun_data) { 1367 printk(ALLOC_FAILURE_MSG, __func__); 1368 goto out; 1369 } 1370 1371 scsi_cmd[0] = REPORT_LUNS; 1372 1373 /* 1374 * bytes 1 - 5: reserved, set to zero. 1375 */ 1376 memset(&scsi_cmd[1], 0, 5); 1377 1378 /* 1379 * bytes 6 - 9: length of the command. 1380 */ 1381 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff; 1382 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff; 1383 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff; 1384 scsi_cmd[9] = (unsigned char) length & 0xff; 1385 1386 scsi_cmd[10] = 0; /* reserved */ 1387 scsi_cmd[11] = 0; /* control */ 1388 1389 /* 1390 * We can get a UNIT ATTENTION, for example a power on/reset, so 1391 * retry a few times (like sd.c does for TEST UNIT READY). 1392 * Experience shows some combinations of adapter/devices get at 1393 * least two power on/resets. 1394 * 1395 * Illegal requests (for devices that do not support REPORT LUNS) 1396 * should come through as a check condition, and will not generate 1397 * a retry. 1398 */ 1399 for (retries = 0; retries < 3; retries++) { 1400 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending" 1401 " REPORT LUNS to %s (try %d)\n", devname, 1402 retries)); 1403 1404 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1405 lun_data, length, &sshdr, 1406 SCSI_TIMEOUT + 4 * HZ, 3, NULL); 1407 1408 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS" 1409 " %s (try %d) result 0x%x\n", result 1410 ? "failed" : "successful", retries, result)); 1411 if (result == 0) 1412 break; 1413 else if (scsi_sense_valid(&sshdr)) { 1414 if (sshdr.sense_key != UNIT_ATTENTION) 1415 break; 1416 } 1417 } 1418 1419 if (result) { 1420 /* 1421 * The device probably does not support a REPORT LUN command 1422 */ 1423 ret = 1; 1424 goto out_err; 1425 } 1426 1427 /* 1428 * Get the length from the first four bytes of lun_data. 1429 */ 1430 data = (u8 *) lun_data->scsi_lun; 1431 length = ((data[0] << 24) | (data[1] << 16) | 1432 (data[2] << 8) | (data[3] << 0)); 1433 1434 num_luns = (length / sizeof(struct scsi_lun)); 1435 if (num_luns > max_scsi_report_luns) { 1436 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)" 1437 " of %d luns reported, try increasing" 1438 " max_scsi_report_luns.\n", devname, 1439 max_scsi_report_luns, num_luns); 1440 num_luns = max_scsi_report_luns; 1441 } 1442 1443 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1444 "scsi scan: REPORT LUN scan\n")); 1445 1446 /* 1447 * Scan the luns in lun_data. The entry at offset 0 is really 1448 * the header, so start at 1 and go up to and including num_luns. 1449 */ 1450 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1451 lun = scsilun_to_int(lunp); 1452 1453 /* 1454 * Check if the unused part of lunp is non-zero, and so 1455 * does not fit in lun. 1456 */ 1457 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) { 1458 int i; 1459 1460 /* 1461 * Output an error displaying the LUN in byte order, 1462 * this differs from what linux would print for the 1463 * integer LUN value. 1464 */ 1465 printk(KERN_WARNING "scsi: %s lun 0x", devname); 1466 data = (char *)lunp->scsi_lun; 1467 for (i = 0; i < sizeof(struct scsi_lun); i++) 1468 printk("%02x", data[i]); 1469 printk(" has a LUN larger than currently supported.\n"); 1470 } else if (lun > sdev->host->max_lun) { 1471 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger" 1472 " than allowed by the host adapter\n", 1473 devname, lun); 1474 } else { 1475 int res; 1476 1477 res = scsi_probe_and_add_lun(starget, 1478 lun, NULL, NULL, rescan, NULL); 1479 if (res == SCSI_SCAN_NO_RESPONSE) { 1480 /* 1481 * Got some results, but now none, abort. 1482 */ 1483 sdev_printk(KERN_ERR, sdev, 1484 "Unexpected response" 1485 " from lun %d while scanning, scan" 1486 " aborted\n", lun); 1487 break; 1488 } 1489 } 1490 } 1491 1492 out_err: 1493 kfree(lun_data); 1494 out: 1495 scsi_device_put(sdev); 1496 if (scsi_device_created(sdev)) 1497 /* 1498 * the sdev we used didn't appear in the report luns scan 1499 */ 1500 scsi_destroy_sdev(sdev); 1501 return ret; 1502 } 1503 1504 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1505 uint id, uint lun, void *hostdata) 1506 { 1507 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1508 struct device *parent = &shost->shost_gendev; 1509 struct scsi_target *starget; 1510 1511 if (strncmp(scsi_scan_type, "none", 4) == 0) 1512 return ERR_PTR(-ENODEV); 1513 1514 starget = scsi_alloc_target(parent, channel, id); 1515 if (!starget) 1516 return ERR_PTR(-ENOMEM); 1517 1518 mutex_lock(&shost->scan_mutex); 1519 if (!shost->async_scan) 1520 scsi_complete_async_scans(); 1521 1522 if (scsi_host_scan_allowed(shost)) 1523 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1524 mutex_unlock(&shost->scan_mutex); 1525 scsi_target_reap(starget); 1526 put_device(&starget->dev); 1527 1528 return sdev; 1529 } 1530 EXPORT_SYMBOL(__scsi_add_device); 1531 1532 int scsi_add_device(struct Scsi_Host *host, uint channel, 1533 uint target, uint lun) 1534 { 1535 struct scsi_device *sdev = 1536 __scsi_add_device(host, channel, target, lun, NULL); 1537 if (IS_ERR(sdev)) 1538 return PTR_ERR(sdev); 1539 1540 scsi_device_put(sdev); 1541 return 0; 1542 } 1543 EXPORT_SYMBOL(scsi_add_device); 1544 1545 void scsi_rescan_device(struct device *dev) 1546 { 1547 struct scsi_driver *drv; 1548 1549 if (!dev->driver) 1550 return; 1551 1552 drv = to_scsi_driver(dev->driver); 1553 if (try_module_get(drv->owner)) { 1554 if (drv->rescan) 1555 drv->rescan(dev); 1556 module_put(drv->owner); 1557 } 1558 } 1559 EXPORT_SYMBOL(scsi_rescan_device); 1560 1561 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1562 unsigned int id, unsigned int lun, int rescan) 1563 { 1564 struct Scsi_Host *shost = dev_to_shost(parent); 1565 int bflags = 0; 1566 int res; 1567 struct scsi_target *starget; 1568 1569 if (shost->this_id == id) 1570 /* 1571 * Don't scan the host adapter 1572 */ 1573 return; 1574 1575 starget = scsi_alloc_target(parent, channel, id); 1576 if (!starget) 1577 return; 1578 1579 if (lun != SCAN_WILD_CARD) { 1580 /* 1581 * Scan for a specific host/chan/id/lun. 1582 */ 1583 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1584 goto out_reap; 1585 } 1586 1587 /* 1588 * Scan LUN 0, if there is some response, scan further. Ideally, we 1589 * would not configure LUN 0 until all LUNs are scanned. 1590 */ 1591 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1592 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1593 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1594 /* 1595 * The REPORT LUN did not scan the target, 1596 * do a sequential scan. 1597 */ 1598 scsi_sequential_lun_scan(starget, bflags, 1599 starget->scsi_level, rescan); 1600 } 1601 1602 out_reap: 1603 /* now determine if the target has any children at all 1604 * and if not, nuke it */ 1605 scsi_target_reap(starget); 1606 1607 put_device(&starget->dev); 1608 } 1609 1610 /** 1611 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1612 * @parent: host to scan 1613 * @channel: channel to scan 1614 * @id: target id to scan 1615 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1616 * @rescan: passed to LUN scanning routines 1617 * 1618 * Description: 1619 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1620 * and possibly all LUNs on the target id. 1621 * 1622 * First try a REPORT LUN scan, if that does not scan the target, do a 1623 * sequential scan of LUNs on the target id. 1624 **/ 1625 void scsi_scan_target(struct device *parent, unsigned int channel, 1626 unsigned int id, unsigned int lun, int rescan) 1627 { 1628 struct Scsi_Host *shost = dev_to_shost(parent); 1629 1630 if (strncmp(scsi_scan_type, "none", 4) == 0) 1631 return; 1632 1633 mutex_lock(&shost->scan_mutex); 1634 if (!shost->async_scan) 1635 scsi_complete_async_scans(); 1636 1637 if (scsi_host_scan_allowed(shost)) 1638 __scsi_scan_target(parent, channel, id, lun, rescan); 1639 mutex_unlock(&shost->scan_mutex); 1640 } 1641 EXPORT_SYMBOL(scsi_scan_target); 1642 1643 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1644 unsigned int id, unsigned int lun, int rescan) 1645 { 1646 uint order_id; 1647 1648 if (id == SCAN_WILD_CARD) 1649 for (id = 0; id < shost->max_id; ++id) { 1650 /* 1651 * XXX adapter drivers when possible (FCP, iSCSI) 1652 * could modify max_id to match the current max, 1653 * not the absolute max. 1654 * 1655 * XXX add a shost id iterator, so for example, 1656 * the FC ID can be the same as a target id 1657 * without a huge overhead of sparse id's. 1658 */ 1659 if (shost->reverse_ordering) 1660 /* 1661 * Scan from high to low id. 1662 */ 1663 order_id = shost->max_id - id - 1; 1664 else 1665 order_id = id; 1666 __scsi_scan_target(&shost->shost_gendev, channel, 1667 order_id, lun, rescan); 1668 } 1669 else 1670 __scsi_scan_target(&shost->shost_gendev, channel, 1671 id, lun, rescan); 1672 } 1673 1674 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1675 unsigned int id, unsigned int lun, int rescan) 1676 { 1677 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1678 "%s: <%u:%u:%u>\n", 1679 __func__, channel, id, lun)); 1680 1681 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1682 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1683 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun))) 1684 return -EINVAL; 1685 1686 mutex_lock(&shost->scan_mutex); 1687 if (!shost->async_scan) 1688 scsi_complete_async_scans(); 1689 1690 if (scsi_host_scan_allowed(shost)) { 1691 if (channel == SCAN_WILD_CARD) 1692 for (channel = 0; channel <= shost->max_channel; 1693 channel++) 1694 scsi_scan_channel(shost, channel, id, lun, 1695 rescan); 1696 else 1697 scsi_scan_channel(shost, channel, id, lun, rescan); 1698 } 1699 mutex_unlock(&shost->scan_mutex); 1700 1701 return 0; 1702 } 1703 1704 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1705 { 1706 struct scsi_device *sdev; 1707 shost_for_each_device(sdev, shost) { 1708 if (!scsi_host_scan_allowed(shost) || 1709 scsi_sysfs_add_sdev(sdev) != 0) 1710 scsi_destroy_sdev(sdev); 1711 } 1712 } 1713 1714 /** 1715 * scsi_prep_async_scan - prepare for an async scan 1716 * @shost: the host which will be scanned 1717 * Returns: a cookie to be passed to scsi_finish_async_scan() 1718 * 1719 * Tells the midlayer this host is going to do an asynchronous scan. 1720 * It reserves the host's position in the scanning list and ensures 1721 * that other asynchronous scans started after this one won't affect the 1722 * ordering of the discovered devices. 1723 */ 1724 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1725 { 1726 struct async_scan_data *data; 1727 unsigned long flags; 1728 1729 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1730 return NULL; 1731 1732 if (shost->async_scan) { 1733 printk("%s called twice for host %d", __func__, 1734 shost->host_no); 1735 dump_stack(); 1736 return NULL; 1737 } 1738 1739 data = kmalloc(sizeof(*data), GFP_KERNEL); 1740 if (!data) 1741 goto err; 1742 data->shost = scsi_host_get(shost); 1743 if (!data->shost) 1744 goto err; 1745 init_completion(&data->prev_finished); 1746 1747 mutex_lock(&shost->scan_mutex); 1748 spin_lock_irqsave(shost->host_lock, flags); 1749 shost->async_scan = 1; 1750 spin_unlock_irqrestore(shost->host_lock, flags); 1751 mutex_unlock(&shost->scan_mutex); 1752 1753 spin_lock(&async_scan_lock); 1754 if (list_empty(&scanning_hosts)) 1755 complete(&data->prev_finished); 1756 list_add_tail(&data->list, &scanning_hosts); 1757 spin_unlock(&async_scan_lock); 1758 1759 return data; 1760 1761 err: 1762 kfree(data); 1763 return NULL; 1764 } 1765 1766 /** 1767 * scsi_finish_async_scan - asynchronous scan has finished 1768 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1769 * 1770 * All the devices currently attached to this host have been found. 1771 * This function announces all the devices it has found to the rest 1772 * of the system. 1773 */ 1774 static void scsi_finish_async_scan(struct async_scan_data *data) 1775 { 1776 struct Scsi_Host *shost; 1777 unsigned long flags; 1778 1779 if (!data) 1780 return; 1781 1782 shost = data->shost; 1783 1784 mutex_lock(&shost->scan_mutex); 1785 1786 if (!shost->async_scan) { 1787 printk("%s called twice for host %d", __func__, 1788 shost->host_no); 1789 dump_stack(); 1790 mutex_unlock(&shost->scan_mutex); 1791 return; 1792 } 1793 1794 wait_for_completion(&data->prev_finished); 1795 1796 scsi_sysfs_add_devices(shost); 1797 1798 spin_lock_irqsave(shost->host_lock, flags); 1799 shost->async_scan = 0; 1800 spin_unlock_irqrestore(shost->host_lock, flags); 1801 1802 mutex_unlock(&shost->scan_mutex); 1803 1804 spin_lock(&async_scan_lock); 1805 list_del(&data->list); 1806 if (!list_empty(&scanning_hosts)) { 1807 struct async_scan_data *next = list_entry(scanning_hosts.next, 1808 struct async_scan_data, list); 1809 complete(&next->prev_finished); 1810 } 1811 spin_unlock(&async_scan_lock); 1812 1813 scsi_host_put(shost); 1814 kfree(data); 1815 } 1816 1817 static void do_scsi_scan_host(struct Scsi_Host *shost) 1818 { 1819 if (shost->hostt->scan_finished) { 1820 unsigned long start = jiffies; 1821 if (shost->hostt->scan_start) 1822 shost->hostt->scan_start(shost); 1823 1824 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1825 msleep(10); 1826 } else { 1827 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1828 SCAN_WILD_CARD, 0); 1829 } 1830 } 1831 1832 static int do_scan_async(void *_data) 1833 { 1834 struct async_scan_data *data = _data; 1835 do_scsi_scan_host(data->shost); 1836 scsi_finish_async_scan(data); 1837 return 0; 1838 } 1839 1840 /** 1841 * scsi_scan_host - scan the given adapter 1842 * @shost: adapter to scan 1843 **/ 1844 void scsi_scan_host(struct Scsi_Host *shost) 1845 { 1846 struct task_struct *p; 1847 struct async_scan_data *data; 1848 1849 if (strncmp(scsi_scan_type, "none", 4) == 0) 1850 return; 1851 1852 data = scsi_prep_async_scan(shost); 1853 if (!data) { 1854 do_scsi_scan_host(shost); 1855 return; 1856 } 1857 1858 p = kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no); 1859 if (IS_ERR(p)) 1860 do_scan_async(data); 1861 } 1862 EXPORT_SYMBOL(scsi_scan_host); 1863 1864 void scsi_forget_host(struct Scsi_Host *shost) 1865 { 1866 struct scsi_device *sdev; 1867 unsigned long flags; 1868 1869 restart: 1870 spin_lock_irqsave(shost->host_lock, flags); 1871 list_for_each_entry(sdev, &shost->__devices, siblings) { 1872 if (sdev->sdev_state == SDEV_DEL) 1873 continue; 1874 spin_unlock_irqrestore(shost->host_lock, flags); 1875 __scsi_remove_device(sdev); 1876 goto restart; 1877 } 1878 spin_unlock_irqrestore(shost->host_lock, flags); 1879 } 1880 1881 /* 1882 * Function: scsi_get_host_dev() 1883 * 1884 * Purpose: Create a scsi_device that points to the host adapter itself. 1885 * 1886 * Arguments: SHpnt - Host that needs a scsi_device 1887 * 1888 * Lock status: None assumed. 1889 * 1890 * Returns: The scsi_device or NULL 1891 * 1892 * Notes: 1893 * Attach a single scsi_device to the Scsi_Host - this should 1894 * be made to look like a "pseudo-device" that points to the 1895 * HA itself. 1896 * 1897 * Note - this device is not accessible from any high-level 1898 * drivers (including generics), which is probably not 1899 * optimal. We can add hooks later to attach 1900 */ 1901 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1902 { 1903 struct scsi_device *sdev = NULL; 1904 struct scsi_target *starget; 1905 1906 mutex_lock(&shost->scan_mutex); 1907 if (!scsi_host_scan_allowed(shost)) 1908 goto out; 1909 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1910 if (!starget) 1911 goto out; 1912 1913 sdev = scsi_alloc_sdev(starget, 0, NULL); 1914 if (sdev) { 1915 sdev->sdev_gendev.parent = get_device(&starget->dev); 1916 sdev->borken = 0; 1917 } else 1918 scsi_target_reap(starget); 1919 put_device(&starget->dev); 1920 out: 1921 mutex_unlock(&shost->scan_mutex); 1922 return sdev; 1923 } 1924 EXPORT_SYMBOL(scsi_get_host_dev); 1925 1926 /* 1927 * Function: scsi_free_host_dev() 1928 * 1929 * Purpose: Free a scsi_device that points to the host adapter itself. 1930 * 1931 * Arguments: SHpnt - Host that needs a scsi_device 1932 * 1933 * Lock status: None assumed. 1934 * 1935 * Returns: Nothing 1936 * 1937 * Notes: 1938 */ 1939 void scsi_free_host_dev(struct scsi_device *sdev) 1940 { 1941 BUG_ON(sdev->id != sdev->host->this_id); 1942 1943 scsi_destroy_sdev(sdev); 1944 } 1945 EXPORT_SYMBOL(scsi_free_host_dev); 1946 1947