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 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 /** 188 * scsi_unlock_floptical - unlock device via a special MODE SENSE command 189 * @sdev: scsi device to send command to 190 * @result: area to store the result of the MODE SENSE 191 * 192 * Description: 193 * Send a vendor specific MODE SENSE (not a MODE SELECT) command. 194 * Called for BLIST_KEY devices. 195 **/ 196 static void scsi_unlock_floptical(struct scsi_device *sdev, 197 unsigned char *result) 198 { 199 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 200 201 printk(KERN_NOTICE "scsi: unlocking floptical drive\n"); 202 scsi_cmd[0] = MODE_SENSE; 203 scsi_cmd[1] = 0; 204 scsi_cmd[2] = 0x2e; 205 scsi_cmd[3] = 0; 206 scsi_cmd[4] = 0x2a; /* size */ 207 scsi_cmd[5] = 0; 208 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, 209 SCSI_TIMEOUT, 3, NULL); 210 } 211 212 /** 213 * scsi_alloc_sdev - allocate and setup a scsi_Device 214 * @starget: which target to allocate a &scsi_device for 215 * @lun: which lun 216 * @hostdata: usually NULL and set by ->slave_alloc instead 217 * 218 * Description: 219 * Allocate, initialize for io, and return a pointer to a scsi_Device. 220 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and 221 * adds scsi_Device to the appropriate list. 222 * 223 * Return value: 224 * scsi_Device pointer, or NULL on failure. 225 **/ 226 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, 227 unsigned int lun, void *hostdata) 228 { 229 struct scsi_device *sdev; 230 int display_failure_msg = 1, ret; 231 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 232 extern void scsi_evt_thread(struct work_struct *work); 233 extern void scsi_requeue_run_queue(struct work_struct *work); 234 235 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, 236 GFP_ATOMIC); 237 if (!sdev) 238 goto out; 239 240 sdev->vendor = scsi_null_device_strs; 241 sdev->model = scsi_null_device_strs; 242 sdev->rev = scsi_null_device_strs; 243 sdev->host = shost; 244 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD; 245 sdev->id = starget->id; 246 sdev->lun = lun; 247 sdev->channel = starget->channel; 248 sdev->sdev_state = SDEV_CREATED; 249 INIT_LIST_HEAD(&sdev->siblings); 250 INIT_LIST_HEAD(&sdev->same_target_siblings); 251 INIT_LIST_HEAD(&sdev->cmd_list); 252 INIT_LIST_HEAD(&sdev->starved_entry); 253 INIT_LIST_HEAD(&sdev->event_list); 254 spin_lock_init(&sdev->list_lock); 255 INIT_WORK(&sdev->event_work, scsi_evt_thread); 256 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue); 257 258 sdev->sdev_gendev.parent = get_device(&starget->dev); 259 sdev->sdev_target = starget; 260 261 /* usually NULL and set by ->slave_alloc instead */ 262 sdev->hostdata = hostdata; 263 264 /* if the device needs this changing, it may do so in the 265 * slave_configure function */ 266 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; 267 268 /* 269 * Some low level driver could use device->type 270 */ 271 sdev->type = -1; 272 273 /* 274 * Assume that the device will have handshaking problems, 275 * and then fix this field later if it turns out it 276 * doesn't 277 */ 278 sdev->borken = 1; 279 280 sdev->request_queue = scsi_alloc_queue(sdev); 281 if (!sdev->request_queue) { 282 /* release fn is set up in scsi_sysfs_device_initialise, so 283 * have to free and put manually here */ 284 put_device(&starget->dev); 285 kfree(sdev); 286 goto out; 287 } 288 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); 289 sdev->request_queue->queuedata = sdev; 290 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun); 291 292 scsi_sysfs_device_initialize(sdev); 293 294 if (shost->hostt->slave_alloc) { 295 ret = shost->hostt->slave_alloc(sdev); 296 if (ret) { 297 /* 298 * if LLDD reports slave not present, don't clutter 299 * console with alloc failure messages 300 */ 301 if (ret == -ENXIO) 302 display_failure_msg = 0; 303 goto out_device_destroy; 304 } 305 } 306 307 return sdev; 308 309 out_device_destroy: 310 __scsi_remove_device(sdev); 311 out: 312 if (display_failure_msg) 313 printk(ALLOC_FAILURE_MSG, __func__); 314 return NULL; 315 } 316 317 static void scsi_target_destroy(struct scsi_target *starget) 318 { 319 struct device *dev = &starget->dev; 320 struct Scsi_Host *shost = dev_to_shost(dev->parent); 321 unsigned long flags; 322 323 starget->state = STARGET_DEL; 324 transport_destroy_device(dev); 325 spin_lock_irqsave(shost->host_lock, flags); 326 if (shost->hostt->target_destroy) 327 shost->hostt->target_destroy(starget); 328 list_del_init(&starget->siblings); 329 spin_unlock_irqrestore(shost->host_lock, flags); 330 put_device(dev); 331 } 332 333 static void scsi_target_dev_release(struct device *dev) 334 { 335 struct device *parent = dev->parent; 336 struct scsi_target *starget = to_scsi_target(dev); 337 338 kfree(starget); 339 put_device(parent); 340 } 341 342 static struct device_type scsi_target_type = { 343 .name = "scsi_target", 344 .release = scsi_target_dev_release, 345 }; 346 347 int scsi_is_target_device(const struct device *dev) 348 { 349 return dev->type == &scsi_target_type; 350 } 351 EXPORT_SYMBOL(scsi_is_target_device); 352 353 static struct scsi_target *__scsi_find_target(struct device *parent, 354 int channel, uint id) 355 { 356 struct scsi_target *starget, *found_starget = NULL; 357 struct Scsi_Host *shost = dev_to_shost(parent); 358 /* 359 * Search for an existing target for this sdev. 360 */ 361 list_for_each_entry(starget, &shost->__targets, siblings) { 362 if (starget->id == id && 363 starget->channel == channel) { 364 found_starget = starget; 365 break; 366 } 367 } 368 if (found_starget) 369 get_device(&found_starget->dev); 370 371 return found_starget; 372 } 373 374 /** 375 * scsi_target_reap_ref_release - remove target from visibility 376 * @kref: the reap_ref in the target being released 377 * 378 * Called on last put of reap_ref, which is the indication that no device 379 * under this target is visible anymore, so render the target invisible in 380 * sysfs. Note: we have to be in user context here because the target reaps 381 * should be done in places where the scsi device visibility is being removed. 382 */ 383 static void scsi_target_reap_ref_release(struct kref *kref) 384 { 385 struct scsi_target *starget 386 = container_of(kref, struct scsi_target, reap_ref); 387 388 /* 389 * if we get here and the target is still in the CREATED state that 390 * means it was allocated but never made visible (because a scan 391 * turned up no LUNs), so don't call device_del() on it. 392 */ 393 if (starget->state != STARGET_CREATED) { 394 transport_remove_device(&starget->dev); 395 device_del(&starget->dev); 396 } 397 scsi_target_destroy(starget); 398 } 399 400 static void scsi_target_reap_ref_put(struct scsi_target *starget) 401 { 402 kref_put(&starget->reap_ref, scsi_target_reap_ref_release); 403 } 404 405 /** 406 * scsi_alloc_target - allocate a new or find an existing target 407 * @parent: parent of the target (need not be a scsi host) 408 * @channel: target channel number (zero if no channels) 409 * @id: target id number 410 * 411 * Return an existing target if one exists, provided it hasn't already 412 * gone into STARGET_DEL state, otherwise allocate a new target. 413 * 414 * The target is returned with an incremented reference, so the caller 415 * is responsible for both reaping and doing a last put 416 */ 417 static struct scsi_target *scsi_alloc_target(struct device *parent, 418 int channel, uint id) 419 { 420 struct Scsi_Host *shost = dev_to_shost(parent); 421 struct device *dev = NULL; 422 unsigned long flags; 423 const int size = sizeof(struct scsi_target) 424 + shost->transportt->target_size; 425 struct scsi_target *starget; 426 struct scsi_target *found_target; 427 int error, ref_got; 428 429 starget = kzalloc(size, GFP_KERNEL); 430 if (!starget) { 431 printk(KERN_ERR "%s: allocation failure\n", __func__); 432 return NULL; 433 } 434 dev = &starget->dev; 435 device_initialize(dev); 436 kref_init(&starget->reap_ref); 437 dev->parent = get_device(parent); 438 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); 439 dev->bus = &scsi_bus_type; 440 dev->type = &scsi_target_type; 441 starget->id = id; 442 starget->channel = channel; 443 starget->can_queue = 0; 444 INIT_LIST_HEAD(&starget->siblings); 445 INIT_LIST_HEAD(&starget->devices); 446 starget->state = STARGET_CREATED; 447 starget->scsi_level = SCSI_2; 448 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED; 449 retry: 450 spin_lock_irqsave(shost->host_lock, flags); 451 452 found_target = __scsi_find_target(parent, channel, id); 453 if (found_target) 454 goto found; 455 456 list_add_tail(&starget->siblings, &shost->__targets); 457 spin_unlock_irqrestore(shost->host_lock, flags); 458 /* allocate and add */ 459 transport_setup_device(dev); 460 if (shost->hostt->target_alloc) { 461 error = shost->hostt->target_alloc(starget); 462 463 if(error) { 464 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); 465 /* don't want scsi_target_reap to do the final 466 * put because it will be under the host lock */ 467 scsi_target_destroy(starget); 468 return NULL; 469 } 470 } 471 get_device(dev); 472 473 return starget; 474 475 found: 476 /* 477 * release routine already fired if kref is zero, so if we can still 478 * take the reference, the target must be alive. If we can't, it must 479 * be dying and we need to wait for a new target 480 */ 481 ref_got = kref_get_unless_zero(&found_target->reap_ref); 482 483 spin_unlock_irqrestore(shost->host_lock, flags); 484 if (ref_got) { 485 put_device(dev); 486 return found_target; 487 } 488 /* 489 * Unfortunately, we found a dying target; need to wait until it's 490 * dead before we can get a new one. There is an anomaly here. We 491 * *should* call scsi_target_reap() to balance the kref_get() of the 492 * reap_ref above. However, since the target being released, it's 493 * already invisible and the reap_ref is irrelevant. If we call 494 * scsi_target_reap() we might spuriously do another device_del() on 495 * an already invisible target. 496 */ 497 put_device(&found_target->dev); 498 /* 499 * length of time is irrelevant here, we just want to yield the CPU 500 * for a tick to avoid busy waiting for the target to die. 501 */ 502 msleep(1); 503 goto retry; 504 } 505 506 /** 507 * scsi_target_reap - check to see if target is in use and destroy if not 508 * @starget: target to be checked 509 * 510 * This is used after removing a LUN or doing a last put of the target 511 * it checks atomically that nothing is using the target and removes 512 * it if so. 513 */ 514 void scsi_target_reap(struct scsi_target *starget) 515 { 516 /* 517 * serious problem if this triggers: STARGET_DEL is only set in the if 518 * the reap_ref drops to zero, so we're trying to do another final put 519 * on an already released kref 520 */ 521 BUG_ON(starget->state == STARGET_DEL); 522 scsi_target_reap_ref_put(starget); 523 } 524 525 /** 526 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string 527 * @s: INQUIRY result string to sanitize 528 * @len: length of the string 529 * 530 * Description: 531 * The SCSI spec says that INQUIRY vendor, product, and revision 532 * strings must consist entirely of graphic ASCII characters, 533 * padded on the right with spaces. Since not all devices obey 534 * this rule, we will replace non-graphic or non-ASCII characters 535 * with spaces. Exception: a NUL character is interpreted as a 536 * string terminator, so all the following characters are set to 537 * spaces. 538 **/ 539 static void sanitize_inquiry_string(unsigned char *s, int len) 540 { 541 int terminated = 0; 542 543 for (; len > 0; (--len, ++s)) { 544 if (*s == 0) 545 terminated = 1; 546 if (terminated || *s < 0x20 || *s > 0x7e) 547 *s = ' '; 548 } 549 } 550 551 /** 552 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY 553 * @sdev: scsi_device to probe 554 * @inq_result: area to store the INQUIRY result 555 * @result_len: len of inq_result 556 * @bflags: store any bflags found here 557 * 558 * Description: 559 * Probe the lun associated with @req using a standard SCSI INQUIRY; 560 * 561 * If the INQUIRY is successful, zero is returned and the 562 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length 563 * are copied to the scsi_device any flags value is stored in *@bflags. 564 **/ 565 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, 566 int result_len, int *bflags) 567 { 568 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 569 int first_inquiry_len, try_inquiry_len, next_inquiry_len; 570 int response_len = 0; 571 int pass, count, result; 572 struct scsi_sense_hdr sshdr; 573 574 *bflags = 0; 575 576 /* Perform up to 3 passes. The first pass uses a conservative 577 * transfer length of 36 unless sdev->inquiry_len specifies a 578 * different value. */ 579 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36; 580 try_inquiry_len = first_inquiry_len; 581 pass = 1; 582 583 next_pass: 584 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, 585 "scsi scan: INQUIRY pass %d length %d\n", 586 pass, try_inquiry_len)); 587 588 /* Each pass gets up to three chances to ignore Unit Attention */ 589 for (count = 0; count < 3; ++count) { 590 int resid; 591 592 memset(scsi_cmd, 0, 6); 593 scsi_cmd[0] = INQUIRY; 594 scsi_cmd[4] = (unsigned char) try_inquiry_len; 595 596 memset(inq_result, 0, try_inquiry_len); 597 598 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 599 inq_result, try_inquiry_len, &sshdr, 600 HZ / 2 + HZ * scsi_inq_timeout, 3, 601 &resid); 602 603 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s " 604 "with code 0x%x\n", 605 result ? "failed" : "successful", result)); 606 607 if (result) { 608 /* 609 * not-ready to ready transition [asc/ascq=0x28/0x0] 610 * or power-on, reset [asc/ascq=0x29/0x0], continue. 611 * INQUIRY should not yield UNIT_ATTENTION 612 * but many buggy devices do so anyway. 613 */ 614 if ((driver_byte(result) & DRIVER_SENSE) && 615 scsi_sense_valid(&sshdr)) { 616 if ((sshdr.sense_key == UNIT_ATTENTION) && 617 ((sshdr.asc == 0x28) || 618 (sshdr.asc == 0x29)) && 619 (sshdr.ascq == 0)) 620 continue; 621 } 622 } else { 623 /* 624 * if nothing was transferred, we try 625 * again. It's a workaround for some USB 626 * devices. 627 */ 628 if (resid == try_inquiry_len) 629 continue; 630 } 631 break; 632 } 633 634 if (result == 0) { 635 sanitize_inquiry_string(&inq_result[8], 8); 636 sanitize_inquiry_string(&inq_result[16], 16); 637 sanitize_inquiry_string(&inq_result[32], 4); 638 639 response_len = inq_result[4] + 5; 640 if (response_len > 255) 641 response_len = first_inquiry_len; /* sanity */ 642 643 /* 644 * Get any flags for this device. 645 * 646 * XXX add a bflags to scsi_device, and replace the 647 * corresponding bit fields in scsi_device, so bflags 648 * need not be passed as an argument. 649 */ 650 *bflags = scsi_get_device_flags(sdev, &inq_result[8], 651 &inq_result[16]); 652 653 /* When the first pass succeeds we gain information about 654 * what larger transfer lengths might work. */ 655 if (pass == 1) { 656 if (BLIST_INQUIRY_36 & *bflags) 657 next_inquiry_len = 36; 658 else if (BLIST_INQUIRY_58 & *bflags) 659 next_inquiry_len = 58; 660 else if (sdev->inquiry_len) 661 next_inquiry_len = sdev->inquiry_len; 662 else 663 next_inquiry_len = response_len; 664 665 /* If more data is available perform the second pass */ 666 if (next_inquiry_len > try_inquiry_len) { 667 try_inquiry_len = next_inquiry_len; 668 pass = 2; 669 goto next_pass; 670 } 671 } 672 673 } else if (pass == 2) { 674 printk(KERN_INFO "scsi scan: %d byte inquiry failed. " 675 "Consider BLIST_INQUIRY_36 for this device\n", 676 try_inquiry_len); 677 678 /* If this pass failed, the third pass goes back and transfers 679 * the same amount as we successfully got in the first pass. */ 680 try_inquiry_len = first_inquiry_len; 681 pass = 3; 682 goto next_pass; 683 } 684 685 /* If the last transfer attempt got an error, assume the 686 * peripheral doesn't exist or is dead. */ 687 if (result) 688 return -EIO; 689 690 /* Don't report any more data than the device says is valid */ 691 sdev->inquiry_len = min(try_inquiry_len, response_len); 692 693 /* 694 * XXX Abort if the response length is less than 36? If less than 695 * 32, the lookup of the device flags (above) could be invalid, 696 * and it would be possible to take an incorrect action - we do 697 * not want to hang because of a short INQUIRY. On the flip side, 698 * if the device is spun down or becoming ready (and so it gives a 699 * short INQUIRY), an abort here prevents any further use of the 700 * device, including spin up. 701 * 702 * On the whole, the best approach seems to be to assume the first 703 * 36 bytes are valid no matter what the device says. That's 704 * better than copying < 36 bytes to the inquiry-result buffer 705 * and displaying garbage for the Vendor, Product, or Revision 706 * strings. 707 */ 708 if (sdev->inquiry_len < 36) { 709 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d)," 710 " using 36\n", sdev->inquiry_len); 711 sdev->inquiry_len = 36; 712 } 713 714 /* 715 * Related to the above issue: 716 * 717 * XXX Devices (disk or all?) should be sent a TEST UNIT READY, 718 * and if not ready, sent a START_STOP to start (maybe spin up) and 719 * then send the INQUIRY again, since the INQUIRY can change after 720 * a device is initialized. 721 * 722 * Ideally, start a device if explicitly asked to do so. This 723 * assumes that a device is spun up on power on, spun down on 724 * request, and then spun up on request. 725 */ 726 727 /* 728 * The scanning code needs to know the scsi_level, even if no 729 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so 730 * non-zero LUNs can be scanned. 731 */ 732 sdev->scsi_level = inq_result[2] & 0x07; 733 if (sdev->scsi_level >= 2 || 734 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) 735 sdev->scsi_level++; 736 sdev->sdev_target->scsi_level = sdev->scsi_level; 737 738 return 0; 739 } 740 741 /** 742 * scsi_add_lun - allocate and fully initialze a scsi_device 743 * @sdev: holds information to be stored in the new scsi_device 744 * @inq_result: holds the result of a previous INQUIRY to the LUN 745 * @bflags: black/white list flag 746 * @async: 1 if this device is being scanned asynchronously 747 * 748 * Description: 749 * Initialize the scsi_device @sdev. Optionally set fields based 750 * on values in *@bflags. 751 * 752 * Return: 753 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 754 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 755 **/ 756 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, 757 int *bflags, int async) 758 { 759 int ret; 760 761 /* 762 * XXX do not save the inquiry, since it can change underneath us, 763 * save just vendor/model/rev. 764 * 765 * Rather than save it and have an ioctl that retrieves the saved 766 * value, have an ioctl that executes the same INQUIRY code used 767 * in scsi_probe_lun, let user level programs doing INQUIRY 768 * scanning run at their own risk, or supply a user level program 769 * that can correctly scan. 770 */ 771 772 /* 773 * Copy at least 36 bytes of INQUIRY data, so that we don't 774 * dereference unallocated memory when accessing the Vendor, 775 * Product, and Revision strings. Badly behaved devices may set 776 * the INQUIRY Additional Length byte to a small value, indicating 777 * these strings are invalid, but often they contain plausible data 778 * nonetheless. It doesn't matter if the device sent < 36 bytes 779 * total, since scsi_probe_lun() initializes inq_result with 0s. 780 */ 781 sdev->inquiry = kmemdup(inq_result, 782 max_t(size_t, sdev->inquiry_len, 36), 783 GFP_ATOMIC); 784 if (sdev->inquiry == NULL) 785 return SCSI_SCAN_NO_RESPONSE; 786 787 sdev->vendor = (char *) (sdev->inquiry + 8); 788 sdev->model = (char *) (sdev->inquiry + 16); 789 sdev->rev = (char *) (sdev->inquiry + 32); 790 791 if (strncmp(sdev->vendor, "ATA ", 8) == 0) { 792 /* 793 * sata emulation layer device. This is a hack to work around 794 * the SATL power management specifications which state that 795 * when the SATL detects the device has gone into standby 796 * mode, it shall respond with NOT READY. 797 */ 798 sdev->allow_restart = 1; 799 } 800 801 if (*bflags & BLIST_ISROM) { 802 sdev->type = TYPE_ROM; 803 sdev->removable = 1; 804 } else { 805 sdev->type = (inq_result[0] & 0x1f); 806 sdev->removable = (inq_result[1] & 0x80) >> 7; 807 } 808 809 switch (sdev->type) { 810 case TYPE_RBC: 811 case TYPE_TAPE: 812 case TYPE_DISK: 813 case TYPE_PRINTER: 814 case TYPE_MOD: 815 case TYPE_PROCESSOR: 816 case TYPE_SCANNER: 817 case TYPE_MEDIUM_CHANGER: 818 case TYPE_ENCLOSURE: 819 case TYPE_COMM: 820 case TYPE_RAID: 821 case TYPE_OSD: 822 sdev->writeable = 1; 823 break; 824 case TYPE_ROM: 825 case TYPE_WORM: 826 sdev->writeable = 0; 827 break; 828 default: 829 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type); 830 } 831 832 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) { 833 /* RBC and MMC devices can return SCSI-3 compliance and yet 834 * still not support REPORT LUNS, so make them act as 835 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is 836 * specifically set */ 837 if ((*bflags & BLIST_REPORTLUN2) == 0) 838 *bflags |= BLIST_NOREPORTLUN; 839 } 840 841 /* 842 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI 843 * spec says: The device server is capable of supporting the 844 * specified peripheral device type on this logical unit. However, 845 * the physical device is not currently connected to this logical 846 * unit. 847 * 848 * The above is vague, as it implies that we could treat 001 and 849 * 011 the same. Stay compatible with previous code, and create a 850 * scsi_device for a PQ of 1 851 * 852 * Don't set the device offline here; rather let the upper 853 * level drivers eval the PQ to decide whether they should 854 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check. 855 */ 856 857 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7; 858 sdev->lockable = sdev->removable; 859 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2); 860 861 if (sdev->scsi_level >= SCSI_3 || 862 (sdev->inquiry_len > 56 && inq_result[56] & 0x04)) 863 sdev->ppr = 1; 864 if (inq_result[7] & 0x60) 865 sdev->wdtr = 1; 866 if (inq_result[7] & 0x10) 867 sdev->sdtr = 1; 868 869 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d " 870 "ANSI: %d%s\n", scsi_device_type(sdev->type), 871 sdev->vendor, sdev->model, sdev->rev, 872 sdev->inq_periph_qual, inq_result[2] & 0x07, 873 (inq_result[3] & 0x0f) == 1 ? " CCS" : ""); 874 875 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) && 876 !(*bflags & BLIST_NOTQ)) 877 sdev->tagged_supported = 1; 878 879 /* 880 * Some devices (Texel CD ROM drives) have handshaking problems 881 * when used with the Seagate controllers. borken is initialized 882 * to 1, and then set it to 0 here. 883 */ 884 if ((*bflags & BLIST_BORKEN) == 0) 885 sdev->borken = 0; 886 887 if (*bflags & BLIST_NO_ULD_ATTACH) 888 sdev->no_uld_attach = 1; 889 890 /* 891 * Apparently some really broken devices (contrary to the SCSI 892 * standards) need to be selected without asserting ATN 893 */ 894 if (*bflags & BLIST_SELECT_NO_ATN) 895 sdev->select_no_atn = 1; 896 897 /* 898 * Maximum 512 sector transfer length 899 * broken RA4x00 Compaq Disk Array 900 */ 901 if (*bflags & BLIST_MAX_512) 902 blk_queue_max_hw_sectors(sdev->request_queue, 512); 903 904 /* 905 * Some devices may not want to have a start command automatically 906 * issued when a device is added. 907 */ 908 if (*bflags & BLIST_NOSTARTONADD) 909 sdev->no_start_on_add = 1; 910 911 if (*bflags & BLIST_SINGLELUN) 912 scsi_target(sdev)->single_lun = 1; 913 914 sdev->use_10_for_rw = 1; 915 916 if (*bflags & BLIST_MS_SKIP_PAGE_08) 917 sdev->skip_ms_page_8 = 1; 918 919 if (*bflags & BLIST_MS_SKIP_PAGE_3F) 920 sdev->skip_ms_page_3f = 1; 921 922 if (*bflags & BLIST_USE_10_BYTE_MS) 923 sdev->use_10_for_ms = 1; 924 925 /* set the device running here so that slave configure 926 * may do I/O */ 927 ret = scsi_device_set_state(sdev, SDEV_RUNNING); 928 if (ret) { 929 ret = scsi_device_set_state(sdev, SDEV_BLOCK); 930 931 if (ret) { 932 sdev_printk(KERN_ERR, sdev, 933 "in wrong state %s to complete scan\n", 934 scsi_device_state_name(sdev->sdev_state)); 935 return SCSI_SCAN_NO_RESPONSE; 936 } 937 } 938 939 if (*bflags & BLIST_MS_192_BYTES_FOR_3F) 940 sdev->use_192_bytes_for_3f = 1; 941 942 if (*bflags & BLIST_NOT_LOCKABLE) 943 sdev->lockable = 0; 944 945 if (*bflags & BLIST_RETRY_HWERROR) 946 sdev->retry_hwerror = 1; 947 948 if (*bflags & BLIST_NO_DIF) 949 sdev->no_dif = 1; 950 951 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; 952 953 if (*bflags & BLIST_SKIP_VPD_PAGES) 954 sdev->skip_vpd_pages = 1; 955 956 transport_configure_device(&sdev->sdev_gendev); 957 958 if (sdev->host->hostt->slave_configure) { 959 ret = sdev->host->hostt->slave_configure(sdev); 960 if (ret) { 961 /* 962 * if LLDD reports slave not present, don't clutter 963 * console with alloc failure messages 964 */ 965 if (ret != -ENXIO) { 966 sdev_printk(KERN_ERR, sdev, 967 "failed to configure device\n"); 968 } 969 return SCSI_SCAN_NO_RESPONSE; 970 } 971 } 972 973 if (sdev->scsi_level >= SCSI_3) 974 scsi_attach_vpd(sdev); 975 976 sdev->max_queue_depth = sdev->queue_depth; 977 978 /* 979 * Ok, the device is now all set up, we can 980 * register it and tell the rest of the kernel 981 * about it. 982 */ 983 if (!async && scsi_sysfs_add_sdev(sdev) != 0) 984 return SCSI_SCAN_NO_RESPONSE; 985 986 return SCSI_SCAN_LUN_PRESENT; 987 } 988 989 #ifdef CONFIG_SCSI_LOGGING 990 /** 991 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace 992 * @buf: Output buffer with at least end-first+1 bytes of space 993 * @inq: Inquiry buffer (input) 994 * @first: Offset of string into inq 995 * @end: Index after last character in inq 996 */ 997 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq, 998 unsigned first, unsigned end) 999 { 1000 unsigned term = 0, idx; 1001 1002 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) { 1003 if (inq[idx+first] > ' ') { 1004 buf[idx] = inq[idx+first]; 1005 term = idx+1; 1006 } else { 1007 buf[idx] = ' '; 1008 } 1009 } 1010 buf[term] = 0; 1011 return buf; 1012 } 1013 #endif 1014 1015 /** 1016 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it 1017 * @starget: pointer to target device structure 1018 * @lun: LUN of target device 1019 * @bflagsp: store bflags here if not NULL 1020 * @sdevp: probe the LUN corresponding to this scsi_device 1021 * @rescan: if nonzero skip some code only needed on first scan 1022 * @hostdata: passed to scsi_alloc_sdev() 1023 * 1024 * Description: 1025 * Call scsi_probe_lun, if a LUN with an attached device is found, 1026 * allocate and set it up by calling scsi_add_lun. 1027 * 1028 * Return: 1029 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device 1030 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is 1031 * attached at the LUN 1032 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized 1033 **/ 1034 static int scsi_probe_and_add_lun(struct scsi_target *starget, 1035 uint lun, int *bflagsp, 1036 struct scsi_device **sdevp, int rescan, 1037 void *hostdata) 1038 { 1039 struct scsi_device *sdev; 1040 unsigned char *result; 1041 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256; 1042 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1043 1044 /* 1045 * The rescan flag is used as an optimization, the first scan of a 1046 * host adapter calls into here with rescan == 0. 1047 */ 1048 sdev = scsi_device_lookup_by_target(starget, lun); 1049 if (sdev) { 1050 if (rescan || !scsi_device_created(sdev)) { 1051 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1052 "scsi scan: device exists on %s\n", 1053 dev_name(&sdev->sdev_gendev))); 1054 if (sdevp) 1055 *sdevp = sdev; 1056 else 1057 scsi_device_put(sdev); 1058 1059 if (bflagsp) 1060 *bflagsp = scsi_get_device_flags(sdev, 1061 sdev->vendor, 1062 sdev->model); 1063 return SCSI_SCAN_LUN_PRESENT; 1064 } 1065 scsi_device_put(sdev); 1066 } else 1067 sdev = scsi_alloc_sdev(starget, lun, hostdata); 1068 if (!sdev) 1069 goto out; 1070 1071 result = kmalloc(result_len, GFP_ATOMIC | 1072 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); 1073 if (!result) 1074 goto out_free_sdev; 1075 1076 if (scsi_probe_lun(sdev, result, result_len, &bflags)) 1077 goto out_free_result; 1078 1079 if (bflagsp) 1080 *bflagsp = bflags; 1081 /* 1082 * result contains valid SCSI INQUIRY data. 1083 */ 1084 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) { 1085 /* 1086 * For a Peripheral qualifier 3 (011b), the SCSI 1087 * spec says: The device server is not capable of 1088 * supporting a physical device on this logical 1089 * unit. 1090 * 1091 * For disks, this implies that there is no 1092 * logical disk configured at sdev->lun, but there 1093 * is a target id responding. 1094 */ 1095 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:" 1096 " peripheral qualifier of 3, device not" 1097 " added\n")) 1098 if (lun == 0) { 1099 SCSI_LOG_SCAN_BUS(1, { 1100 unsigned char vend[9]; 1101 unsigned char mod[17]; 1102 1103 sdev_printk(KERN_INFO, sdev, 1104 "scsi scan: consider passing scsi_mod." 1105 "dev_flags=%s:%s:0x240 or 0x1000240\n", 1106 scsi_inq_str(vend, result, 8, 16), 1107 scsi_inq_str(mod, result, 16, 32)); 1108 }); 1109 1110 } 1111 1112 res = SCSI_SCAN_TARGET_PRESENT; 1113 goto out_free_result; 1114 } 1115 1116 /* 1117 * Some targets may set slight variations of PQ and PDT to signal 1118 * that no LUN is present, so don't add sdev in these cases. 1119 * Two specific examples are: 1120 * 1) NetApp targets: return PQ=1, PDT=0x1f 1121 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved" 1122 * in the UFI 1.0 spec (we cannot rely on reserved bits). 1123 * 1124 * References: 1125 * 1) SCSI SPC-3, pp. 145-146 1126 * PQ=1: "A peripheral device having the specified peripheral 1127 * device type is not connected to this logical unit. However, the 1128 * device server is capable of supporting the specified peripheral 1129 * device type on this logical unit." 1130 * PDT=0x1f: "Unknown or no device type" 1131 * 2) USB UFI 1.0, p. 20 1132 * PDT=00h Direct-access device (floppy) 1133 * PDT=1Fh none (no FDD connected to the requested logical unit) 1134 */ 1135 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) && 1136 (result[0] & 0x1f) == 0x1f && 1137 !scsi_is_wlun(lun)) { 1138 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO 1139 "scsi scan: peripheral device type" 1140 " of 31, no device added\n")); 1141 res = SCSI_SCAN_TARGET_PRESENT; 1142 goto out_free_result; 1143 } 1144 1145 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan); 1146 if (res == SCSI_SCAN_LUN_PRESENT) { 1147 if (bflags & BLIST_KEY) { 1148 sdev->lockable = 0; 1149 scsi_unlock_floptical(sdev, result); 1150 } 1151 } 1152 1153 out_free_result: 1154 kfree(result); 1155 out_free_sdev: 1156 if (res == SCSI_SCAN_LUN_PRESENT) { 1157 if (sdevp) { 1158 if (scsi_device_get(sdev) == 0) { 1159 *sdevp = sdev; 1160 } else { 1161 __scsi_remove_device(sdev); 1162 res = SCSI_SCAN_NO_RESPONSE; 1163 } 1164 } 1165 } else 1166 __scsi_remove_device(sdev); 1167 out: 1168 return res; 1169 } 1170 1171 /** 1172 * scsi_sequential_lun_scan - sequentially scan a SCSI target 1173 * @starget: pointer to target structure to scan 1174 * @bflags: black/white list flag for LUN 0 1175 * @scsi_level: Which version of the standard does this device adhere to 1176 * @rescan: passed to scsi_probe_add_lun() 1177 * 1178 * Description: 1179 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been 1180 * scanned) to some maximum lun until a LUN is found with no device 1181 * attached. Use the bflags to figure out any oddities. 1182 * 1183 * Modifies sdevscan->lun. 1184 **/ 1185 static void scsi_sequential_lun_scan(struct scsi_target *starget, 1186 int bflags, int scsi_level, int rescan) 1187 { 1188 unsigned int sparse_lun, lun, max_dev_lun; 1189 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); 1190 1191 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of" 1192 "%s\n", dev_name(&starget->dev))); 1193 1194 max_dev_lun = min(max_scsi_luns, shost->max_lun); 1195 /* 1196 * If this device is known to support sparse multiple units, 1197 * override the other settings, and scan all of them. Normally, 1198 * SCSI-3 devices should be scanned via the REPORT LUNS. 1199 */ 1200 if (bflags & BLIST_SPARSELUN) { 1201 max_dev_lun = shost->max_lun; 1202 sparse_lun = 1; 1203 } else 1204 sparse_lun = 0; 1205 1206 /* 1207 * If less than SCSI_1_CSS, and no special lun scaning, stop 1208 * scanning; this matches 2.4 behaviour, but could just be a bug 1209 * (to continue scanning a SCSI_1_CSS device). 1210 * 1211 * This test is broken. We might not have any device on lun0 for 1212 * a sparselun device, and if that's the case then how would we 1213 * know the real scsi_level, eh? It might make sense to just not 1214 * scan any SCSI_1 device for non-0 luns, but that check would best 1215 * go into scsi_alloc_sdev() and just have it return null when asked 1216 * to alloc an sdev for lun > 0 on an already found SCSI_1 device. 1217 * 1218 if ((sdevscan->scsi_level < SCSI_1_CCS) && 1219 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN)) 1220 == 0)) 1221 return; 1222 */ 1223 /* 1224 * If this device is known to support multiple units, override 1225 * the other settings, and scan all of them. 1226 */ 1227 if (bflags & BLIST_FORCELUN) 1228 max_dev_lun = shost->max_lun; 1229 /* 1230 * REGAL CDC-4X: avoid hang after LUN 4 1231 */ 1232 if (bflags & BLIST_MAX5LUN) 1233 max_dev_lun = min(5U, max_dev_lun); 1234 /* 1235 * Do not scan SCSI-2 or lower device past LUN 7, unless 1236 * BLIST_LARGELUN. 1237 */ 1238 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN)) 1239 max_dev_lun = min(8U, max_dev_lun); 1240 1241 /* 1242 * We have already scanned LUN 0, so start at LUN 1. Keep scanning 1243 * until we reach the max, or no LUN is found and we are not 1244 * sparse_lun. 1245 */ 1246 for (lun = 1; lun < max_dev_lun; ++lun) 1247 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, 1248 NULL) != SCSI_SCAN_LUN_PRESENT) && 1249 !sparse_lun) 1250 return; 1251 } 1252 1253 /** 1254 * scsilun_to_int - convert a scsi_lun to an int 1255 * @scsilun: struct scsi_lun to be converted. 1256 * 1257 * Description: 1258 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered 1259 * integer, and return the result. The caller must check for 1260 * truncation before using this function. 1261 * 1262 * Notes: 1263 * The struct scsi_lun is assumed to be four levels, with each level 1264 * effectively containing a SCSI byte-ordered (big endian) short; the 1265 * addressing bits of each level are ignored (the highest two bits). 1266 * For a description of the LUN format, post SCSI-3 see the SCSI 1267 * Architecture Model, for SCSI-3 see the SCSI Controller Commands. 1268 * 1269 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns 1270 * the integer: 0x0b030a04 1271 **/ 1272 int scsilun_to_int(struct scsi_lun *scsilun) 1273 { 1274 int i; 1275 unsigned int lun; 1276 1277 lun = 0; 1278 for (i = 0; i < sizeof(lun); i += 2) 1279 lun = lun | (((scsilun->scsi_lun[i] << 8) | 1280 scsilun->scsi_lun[i + 1]) << (i * 8)); 1281 return lun; 1282 } 1283 EXPORT_SYMBOL(scsilun_to_int); 1284 1285 /** 1286 * int_to_scsilun - reverts an int into a scsi_lun 1287 * @lun: integer to be reverted 1288 * @scsilun: struct scsi_lun to be set. 1289 * 1290 * Description: 1291 * Reverts the functionality of the scsilun_to_int, which packed 1292 * an 8-byte lun value into an int. This routine unpacks the int 1293 * back into the lun value. 1294 * Note: the scsilun_to_int() routine does not truly handle all 1295 * 8bytes of the lun value. This functions restores only as much 1296 * as was set by the routine. 1297 * 1298 * Notes: 1299 * Given an integer : 0x0b030a04, this function returns a 1300 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00 1301 * 1302 **/ 1303 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun) 1304 { 1305 int i; 1306 1307 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun)); 1308 1309 for (i = 0; i < sizeof(lun); i += 2) { 1310 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF; 1311 scsilun->scsi_lun[i+1] = lun & 0xFF; 1312 lun = lun >> 16; 1313 } 1314 } 1315 EXPORT_SYMBOL(int_to_scsilun); 1316 1317 /** 1318 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results 1319 * @starget: which target 1320 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN 1321 * @rescan: nonzero if we can skip code only needed on first scan 1322 * 1323 * Description: 1324 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command. 1325 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun. 1326 * 1327 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8 1328 * LUNs even if it's older than SCSI-3. 1329 * If BLIST_NOREPORTLUN is set, return 1 always. 1330 * If BLIST_NOLUN is set, return 0 always. 1331 * If starget->no_report_luns is set, return 1 always. 1332 * 1333 * Return: 1334 * 0: scan completed (or no memory, so further scanning is futile) 1335 * 1: could not scan with REPORT LUN 1336 **/ 1337 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags, 1338 int rescan) 1339 { 1340 char devname[64]; 1341 unsigned char scsi_cmd[MAX_COMMAND_SIZE]; 1342 unsigned int length; 1343 unsigned int lun; 1344 unsigned int num_luns; 1345 unsigned int retries; 1346 int result; 1347 struct scsi_lun *lunp, *lun_data; 1348 u8 *data; 1349 struct scsi_sense_hdr sshdr; 1350 struct scsi_device *sdev; 1351 struct Scsi_Host *shost = dev_to_shost(&starget->dev); 1352 int ret = 0; 1353 1354 /* 1355 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set. 1356 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does 1357 * support more than 8 LUNs. 1358 * Don't attempt if the target doesn't support REPORT LUNS. 1359 */ 1360 if (bflags & BLIST_NOREPORTLUN) 1361 return 1; 1362 if (starget->scsi_level < SCSI_2 && 1363 starget->scsi_level != SCSI_UNKNOWN) 1364 return 1; 1365 if (starget->scsi_level < SCSI_3 && 1366 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8)) 1367 return 1; 1368 if (bflags & BLIST_NOLUN) 1369 return 0; 1370 if (starget->no_report_luns) 1371 return 1; 1372 1373 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) { 1374 sdev = scsi_alloc_sdev(starget, 0, NULL); 1375 if (!sdev) 1376 return 0; 1377 if (scsi_device_get(sdev)) { 1378 __scsi_remove_device(sdev); 1379 return 0; 1380 } 1381 } 1382 1383 sprintf(devname, "host %d channel %d id %d", 1384 shost->host_no, sdev->channel, sdev->id); 1385 1386 /* 1387 * Allocate enough to hold the header (the same size as one scsi_lun) 1388 * plus the max number of luns we are requesting. 1389 * 1390 * Reallocating and trying again (with the exact amount we need) 1391 * would be nice, but then we need to somehow limit the size 1392 * allocated based on the available memory and the limits of 1393 * kmalloc - we don't want a kmalloc() failure of a huge value to 1394 * prevent us from finding any LUNs on this target. 1395 */ 1396 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun); 1397 lun_data = kmalloc(length, GFP_ATOMIC | 1398 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); 1399 if (!lun_data) { 1400 printk(ALLOC_FAILURE_MSG, __func__); 1401 goto out; 1402 } 1403 1404 scsi_cmd[0] = REPORT_LUNS; 1405 1406 /* 1407 * bytes 1 - 5: reserved, set to zero. 1408 */ 1409 memset(&scsi_cmd[1], 0, 5); 1410 1411 /* 1412 * bytes 6 - 9: length of the command. 1413 */ 1414 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff; 1415 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff; 1416 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff; 1417 scsi_cmd[9] = (unsigned char) length & 0xff; 1418 1419 scsi_cmd[10] = 0; /* reserved */ 1420 scsi_cmd[11] = 0; /* control */ 1421 1422 /* 1423 * We can get a UNIT ATTENTION, for example a power on/reset, so 1424 * retry a few times (like sd.c does for TEST UNIT READY). 1425 * Experience shows some combinations of adapter/devices get at 1426 * least two power on/resets. 1427 * 1428 * Illegal requests (for devices that do not support REPORT LUNS) 1429 * should come through as a check condition, and will not generate 1430 * a retry. 1431 */ 1432 for (retries = 0; retries < 3; retries++) { 1433 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending" 1434 " REPORT LUNS to %s (try %d)\n", devname, 1435 retries)); 1436 1437 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, 1438 lun_data, length, &sshdr, 1439 SCSI_TIMEOUT + 4 * HZ, 3, NULL); 1440 1441 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS" 1442 " %s (try %d) result 0x%x\n", result 1443 ? "failed" : "successful", retries, result)); 1444 if (result == 0) 1445 break; 1446 else if (scsi_sense_valid(&sshdr)) { 1447 if (sshdr.sense_key != UNIT_ATTENTION) 1448 break; 1449 } 1450 } 1451 1452 if (result) { 1453 /* 1454 * The device probably does not support a REPORT LUN command 1455 */ 1456 ret = 1; 1457 goto out_err; 1458 } 1459 1460 /* 1461 * Get the length from the first four bytes of lun_data. 1462 */ 1463 data = (u8 *) lun_data->scsi_lun; 1464 length = ((data[0] << 24) | (data[1] << 16) | 1465 (data[2] << 8) | (data[3] << 0)); 1466 1467 num_luns = (length / sizeof(struct scsi_lun)); 1468 if (num_luns > max_scsi_report_luns) { 1469 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)" 1470 " of %d luns reported, try increasing" 1471 " max_scsi_report_luns.\n", devname, 1472 max_scsi_report_luns, num_luns); 1473 num_luns = max_scsi_report_luns; 1474 } 1475 1476 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, 1477 "scsi scan: REPORT LUN scan\n")); 1478 1479 /* 1480 * Scan the luns in lun_data. The entry at offset 0 is really 1481 * the header, so start at 1 and go up to and including num_luns. 1482 */ 1483 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) { 1484 lun = scsilun_to_int(lunp); 1485 1486 /* 1487 * Check if the unused part of lunp is non-zero, and so 1488 * does not fit in lun. 1489 */ 1490 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) { 1491 int i; 1492 1493 /* 1494 * Output an error displaying the LUN in byte order, 1495 * this differs from what linux would print for the 1496 * integer LUN value. 1497 */ 1498 printk(KERN_WARNING "scsi: %s lun 0x", devname); 1499 data = (char *)lunp->scsi_lun; 1500 for (i = 0; i < sizeof(struct scsi_lun); i++) 1501 printk("%02x", data[i]); 1502 printk(" has a LUN larger than currently supported.\n"); 1503 } else if (lun > sdev->host->max_lun) { 1504 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger" 1505 " than allowed by the host adapter\n", 1506 devname, lun); 1507 } else { 1508 int res; 1509 1510 res = scsi_probe_and_add_lun(starget, 1511 lun, NULL, NULL, rescan, NULL); 1512 if (res == SCSI_SCAN_NO_RESPONSE) { 1513 /* 1514 * Got some results, but now none, abort. 1515 */ 1516 sdev_printk(KERN_ERR, sdev, 1517 "Unexpected response" 1518 " from lun %d while scanning, scan" 1519 " aborted\n", lun); 1520 break; 1521 } 1522 } 1523 } 1524 1525 out_err: 1526 kfree(lun_data); 1527 out: 1528 scsi_device_put(sdev); 1529 if (scsi_device_created(sdev)) 1530 /* 1531 * the sdev we used didn't appear in the report luns scan 1532 */ 1533 __scsi_remove_device(sdev); 1534 return ret; 1535 } 1536 1537 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, 1538 uint id, uint lun, void *hostdata) 1539 { 1540 struct scsi_device *sdev = ERR_PTR(-ENODEV); 1541 struct device *parent = &shost->shost_gendev; 1542 struct scsi_target *starget; 1543 1544 if (strncmp(scsi_scan_type, "none", 4) == 0) 1545 return ERR_PTR(-ENODEV); 1546 1547 starget = scsi_alloc_target(parent, channel, id); 1548 if (!starget) 1549 return ERR_PTR(-ENOMEM); 1550 scsi_autopm_get_target(starget); 1551 1552 mutex_lock(&shost->scan_mutex); 1553 if (!shost->async_scan) 1554 scsi_complete_async_scans(); 1555 1556 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1557 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); 1558 scsi_autopm_put_host(shost); 1559 } 1560 mutex_unlock(&shost->scan_mutex); 1561 scsi_autopm_put_target(starget); 1562 /* 1563 * paired with scsi_alloc_target(). Target will be destroyed unless 1564 * scsi_probe_and_add_lun made an underlying device visible 1565 */ 1566 scsi_target_reap(starget); 1567 put_device(&starget->dev); 1568 1569 return sdev; 1570 } 1571 EXPORT_SYMBOL(__scsi_add_device); 1572 1573 int scsi_add_device(struct Scsi_Host *host, uint channel, 1574 uint target, uint lun) 1575 { 1576 struct scsi_device *sdev = 1577 __scsi_add_device(host, channel, target, lun, NULL); 1578 if (IS_ERR(sdev)) 1579 return PTR_ERR(sdev); 1580 1581 scsi_device_put(sdev); 1582 return 0; 1583 } 1584 EXPORT_SYMBOL(scsi_add_device); 1585 1586 void scsi_rescan_device(struct device *dev) 1587 { 1588 struct scsi_driver *drv; 1589 1590 if (!dev->driver) 1591 return; 1592 1593 drv = to_scsi_driver(dev->driver); 1594 if (try_module_get(drv->owner)) { 1595 if (drv->rescan) 1596 drv->rescan(dev); 1597 module_put(drv->owner); 1598 } 1599 } 1600 EXPORT_SYMBOL(scsi_rescan_device); 1601 1602 static void __scsi_scan_target(struct device *parent, unsigned int channel, 1603 unsigned int id, unsigned int lun, int rescan) 1604 { 1605 struct Scsi_Host *shost = dev_to_shost(parent); 1606 int bflags = 0; 1607 int res; 1608 struct scsi_target *starget; 1609 1610 if (shost->this_id == id) 1611 /* 1612 * Don't scan the host adapter 1613 */ 1614 return; 1615 1616 starget = scsi_alloc_target(parent, channel, id); 1617 if (!starget) 1618 return; 1619 scsi_autopm_get_target(starget); 1620 1621 if (lun != SCAN_WILD_CARD) { 1622 /* 1623 * Scan for a specific host/chan/id/lun. 1624 */ 1625 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL); 1626 goto out_reap; 1627 } 1628 1629 /* 1630 * Scan LUN 0, if there is some response, scan further. Ideally, we 1631 * would not configure LUN 0 until all LUNs are scanned. 1632 */ 1633 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL); 1634 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) { 1635 if (scsi_report_lun_scan(starget, bflags, rescan) != 0) 1636 /* 1637 * The REPORT LUN did not scan the target, 1638 * do a sequential scan. 1639 */ 1640 scsi_sequential_lun_scan(starget, bflags, 1641 starget->scsi_level, rescan); 1642 } 1643 1644 out_reap: 1645 scsi_autopm_put_target(starget); 1646 /* 1647 * paired with scsi_alloc_target(): determine if the target has 1648 * any children at all and if not, nuke it 1649 */ 1650 scsi_target_reap(starget); 1651 1652 put_device(&starget->dev); 1653 } 1654 1655 /** 1656 * scsi_scan_target - scan a target id, possibly including all LUNs on the target. 1657 * @parent: host to scan 1658 * @channel: channel to scan 1659 * @id: target id to scan 1660 * @lun: Specific LUN to scan or SCAN_WILD_CARD 1661 * @rescan: passed to LUN scanning routines 1662 * 1663 * Description: 1664 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0, 1665 * and possibly all LUNs on the target id. 1666 * 1667 * First try a REPORT LUN scan, if that does not scan the target, do a 1668 * sequential scan of LUNs on the target id. 1669 **/ 1670 void scsi_scan_target(struct device *parent, unsigned int channel, 1671 unsigned int id, unsigned int lun, int rescan) 1672 { 1673 struct Scsi_Host *shost = dev_to_shost(parent); 1674 1675 if (strncmp(scsi_scan_type, "none", 4) == 0) 1676 return; 1677 1678 mutex_lock(&shost->scan_mutex); 1679 if (!shost->async_scan) 1680 scsi_complete_async_scans(); 1681 1682 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1683 __scsi_scan_target(parent, channel, id, lun, rescan); 1684 scsi_autopm_put_host(shost); 1685 } 1686 mutex_unlock(&shost->scan_mutex); 1687 } 1688 EXPORT_SYMBOL(scsi_scan_target); 1689 1690 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel, 1691 unsigned int id, unsigned int lun, int rescan) 1692 { 1693 uint order_id; 1694 1695 if (id == SCAN_WILD_CARD) 1696 for (id = 0; id < shost->max_id; ++id) { 1697 /* 1698 * XXX adapter drivers when possible (FCP, iSCSI) 1699 * could modify max_id to match the current max, 1700 * not the absolute max. 1701 * 1702 * XXX add a shost id iterator, so for example, 1703 * the FC ID can be the same as a target id 1704 * without a huge overhead of sparse id's. 1705 */ 1706 if (shost->reverse_ordering) 1707 /* 1708 * Scan from high to low id. 1709 */ 1710 order_id = shost->max_id - id - 1; 1711 else 1712 order_id = id; 1713 __scsi_scan_target(&shost->shost_gendev, channel, 1714 order_id, lun, rescan); 1715 } 1716 else 1717 __scsi_scan_target(&shost->shost_gendev, channel, 1718 id, lun, rescan); 1719 } 1720 1721 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, 1722 unsigned int id, unsigned int lun, int rescan) 1723 { 1724 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost, 1725 "%s: <%u:%u:%u>\n", 1726 __func__, channel, id, lun)); 1727 1728 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) || 1729 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) || 1730 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun))) 1731 return -EINVAL; 1732 1733 mutex_lock(&shost->scan_mutex); 1734 if (!shost->async_scan) 1735 scsi_complete_async_scans(); 1736 1737 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { 1738 if (channel == SCAN_WILD_CARD) 1739 for (channel = 0; channel <= shost->max_channel; 1740 channel++) 1741 scsi_scan_channel(shost, channel, id, lun, 1742 rescan); 1743 else 1744 scsi_scan_channel(shost, channel, id, lun, rescan); 1745 scsi_autopm_put_host(shost); 1746 } 1747 mutex_unlock(&shost->scan_mutex); 1748 1749 return 0; 1750 } 1751 1752 static void scsi_sysfs_add_devices(struct Scsi_Host *shost) 1753 { 1754 struct scsi_device *sdev; 1755 shost_for_each_device(sdev, shost) { 1756 /* target removed before the device could be added */ 1757 if (sdev->sdev_state == SDEV_DEL) 1758 continue; 1759 if (!scsi_host_scan_allowed(shost) || 1760 scsi_sysfs_add_sdev(sdev) != 0) 1761 __scsi_remove_device(sdev); 1762 } 1763 } 1764 1765 /** 1766 * scsi_prep_async_scan - prepare for an async scan 1767 * @shost: the host which will be scanned 1768 * Returns: a cookie to be passed to scsi_finish_async_scan() 1769 * 1770 * Tells the midlayer this host is going to do an asynchronous scan. 1771 * It reserves the host's position in the scanning list and ensures 1772 * that other asynchronous scans started after this one won't affect the 1773 * ordering of the discovered devices. 1774 */ 1775 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) 1776 { 1777 struct async_scan_data *data; 1778 unsigned long flags; 1779 1780 if (strncmp(scsi_scan_type, "sync", 4) == 0) 1781 return NULL; 1782 1783 if (shost->async_scan) { 1784 printk("%s called twice for host %d", __func__, 1785 shost->host_no); 1786 dump_stack(); 1787 return NULL; 1788 } 1789 1790 data = kmalloc(sizeof(*data), GFP_KERNEL); 1791 if (!data) 1792 goto err; 1793 data->shost = scsi_host_get(shost); 1794 if (!data->shost) 1795 goto err; 1796 init_completion(&data->prev_finished); 1797 1798 mutex_lock(&shost->scan_mutex); 1799 spin_lock_irqsave(shost->host_lock, flags); 1800 shost->async_scan = 1; 1801 spin_unlock_irqrestore(shost->host_lock, flags); 1802 mutex_unlock(&shost->scan_mutex); 1803 1804 spin_lock(&async_scan_lock); 1805 if (list_empty(&scanning_hosts)) 1806 complete(&data->prev_finished); 1807 list_add_tail(&data->list, &scanning_hosts); 1808 spin_unlock(&async_scan_lock); 1809 1810 return data; 1811 1812 err: 1813 kfree(data); 1814 return NULL; 1815 } 1816 1817 /** 1818 * scsi_finish_async_scan - asynchronous scan has finished 1819 * @data: cookie returned from earlier call to scsi_prep_async_scan() 1820 * 1821 * All the devices currently attached to this host have been found. 1822 * This function announces all the devices it has found to the rest 1823 * of the system. 1824 */ 1825 static void scsi_finish_async_scan(struct async_scan_data *data) 1826 { 1827 struct Scsi_Host *shost; 1828 unsigned long flags; 1829 1830 if (!data) 1831 return; 1832 1833 shost = data->shost; 1834 1835 mutex_lock(&shost->scan_mutex); 1836 1837 if (!shost->async_scan) { 1838 printk("%s called twice for host %d", __func__, 1839 shost->host_no); 1840 dump_stack(); 1841 mutex_unlock(&shost->scan_mutex); 1842 return; 1843 } 1844 1845 wait_for_completion(&data->prev_finished); 1846 1847 scsi_sysfs_add_devices(shost); 1848 1849 spin_lock_irqsave(shost->host_lock, flags); 1850 shost->async_scan = 0; 1851 spin_unlock_irqrestore(shost->host_lock, flags); 1852 1853 mutex_unlock(&shost->scan_mutex); 1854 1855 spin_lock(&async_scan_lock); 1856 list_del(&data->list); 1857 if (!list_empty(&scanning_hosts)) { 1858 struct async_scan_data *next = list_entry(scanning_hosts.next, 1859 struct async_scan_data, list); 1860 complete(&next->prev_finished); 1861 } 1862 spin_unlock(&async_scan_lock); 1863 1864 scsi_autopm_put_host(shost); 1865 scsi_host_put(shost); 1866 kfree(data); 1867 } 1868 1869 static void do_scsi_scan_host(struct Scsi_Host *shost) 1870 { 1871 if (shost->hostt->scan_finished) { 1872 unsigned long start = jiffies; 1873 if (shost->hostt->scan_start) 1874 shost->hostt->scan_start(shost); 1875 1876 while (!shost->hostt->scan_finished(shost, jiffies - start)) 1877 msleep(10); 1878 } else { 1879 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, 1880 SCAN_WILD_CARD, 0); 1881 } 1882 } 1883 1884 static void do_scan_async(void *_data, async_cookie_t c) 1885 { 1886 struct async_scan_data *data = _data; 1887 struct Scsi_Host *shost = data->shost; 1888 1889 do_scsi_scan_host(shost); 1890 scsi_finish_async_scan(data); 1891 } 1892 1893 /** 1894 * scsi_scan_host - scan the given adapter 1895 * @shost: adapter to scan 1896 **/ 1897 void scsi_scan_host(struct Scsi_Host *shost) 1898 { 1899 struct async_scan_data *data; 1900 1901 if (strncmp(scsi_scan_type, "none", 4) == 0) 1902 return; 1903 if (scsi_autopm_get_host(shost) < 0) 1904 return; 1905 1906 data = scsi_prep_async_scan(shost); 1907 if (!data) { 1908 do_scsi_scan_host(shost); 1909 scsi_autopm_put_host(shost); 1910 return; 1911 } 1912 1913 /* register with the async subsystem so wait_for_device_probe() 1914 * will flush this work 1915 */ 1916 async_schedule(do_scan_async, data); 1917 1918 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */ 1919 } 1920 EXPORT_SYMBOL(scsi_scan_host); 1921 1922 void scsi_forget_host(struct Scsi_Host *shost) 1923 { 1924 struct scsi_device *sdev; 1925 unsigned long flags; 1926 1927 restart: 1928 spin_lock_irqsave(shost->host_lock, flags); 1929 list_for_each_entry(sdev, &shost->__devices, siblings) { 1930 if (sdev->sdev_state == SDEV_DEL) 1931 continue; 1932 spin_unlock_irqrestore(shost->host_lock, flags); 1933 __scsi_remove_device(sdev); 1934 goto restart; 1935 } 1936 spin_unlock_irqrestore(shost->host_lock, flags); 1937 } 1938 1939 /** 1940 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself 1941 * @shost: Host that needs a scsi_device 1942 * 1943 * Lock status: None assumed. 1944 * 1945 * Returns: The scsi_device or NULL 1946 * 1947 * Notes: 1948 * Attach a single scsi_device to the Scsi_Host - this should 1949 * be made to look like a "pseudo-device" that points to the 1950 * HA itself. 1951 * 1952 * Note - this device is not accessible from any high-level 1953 * drivers (including generics), which is probably not 1954 * optimal. We can add hooks later to attach. 1955 */ 1956 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) 1957 { 1958 struct scsi_device *sdev = NULL; 1959 struct scsi_target *starget; 1960 1961 mutex_lock(&shost->scan_mutex); 1962 if (!scsi_host_scan_allowed(shost)) 1963 goto out; 1964 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); 1965 if (!starget) 1966 goto out; 1967 1968 sdev = scsi_alloc_sdev(starget, 0, NULL); 1969 if (sdev) 1970 sdev->borken = 0; 1971 else 1972 scsi_target_reap(starget); 1973 put_device(&starget->dev); 1974 out: 1975 mutex_unlock(&shost->scan_mutex); 1976 return sdev; 1977 } 1978 EXPORT_SYMBOL(scsi_get_host_dev); 1979 1980 /** 1981 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself 1982 * @sdev: Host device to be freed 1983 * 1984 * Lock status: None assumed. 1985 * 1986 * Returns: Nothing 1987 */ 1988 void scsi_free_host_dev(struct scsi_device *sdev) 1989 { 1990 BUG_ON(sdev->id != sdev->host->this_id); 1991 1992 __scsi_remove_device(sdev); 1993 } 1994 EXPORT_SYMBOL(scsi_free_host_dev); 1995 1996