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1// SPDX-License-Identifier: GPL-2.02/*3 * scsi_scan.c4 *5 * Copyright (C) 2000 Eric Youngdale,6 * Copyright (C) 2002 Patrick Mansfield7 *8 * The general scanning/probing algorithm is as follows, exceptions are9 * made to it depending on device specific flags, compilation options, and10 * global variable (boot or module load time) settings.11 *12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a13 * device attached, a scsi_device is allocated and setup for it.14 *15 * For every id of every channel on the given host:16 *17 * Scan LUN 0; if the target responds to LUN 0 (even if there is no18 * device or storage attached to LUN 0):19 *20 * If LUN 0 has a device attached, allocate and setup a21 * scsi_device for it.22 *23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan24 * all of the LUNs returned by the REPORT LUN; else,25 * sequentially scan LUNs up until some maximum is reached,26 * or a LUN is seen that cannot have a device attached to it.27 */28 29#include <linux/module.h>30#include <linux/moduleparam.h>31#include <linux/init.h>32#include <linux/blkdev.h>33#include <linux/delay.h>34#include <linux/kthread.h>35#include <linux/spinlock.h>36#include <linux/async.h>37#include <linux/slab.h>38#include <linux/unaligned.h>39 40#include <scsi/scsi.h>41#include <scsi/scsi_cmnd.h>42#include <scsi/scsi_device.h>43#include <scsi/scsi_driver.h>44#include <scsi/scsi_devinfo.h>45#include <scsi/scsi_host.h>46#include <scsi/scsi_transport.h>47#include <scsi/scsi_dh.h>48#include <scsi/scsi_eh.h>49 50#include "scsi_priv.h"51#include "scsi_logging.h"52 53#define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \54 " SCSI scanning, some SCSI devices might not be configured\n"55 56/*57 * Default timeout58 */59#define SCSI_TIMEOUT (2*HZ)60#define SCSI_REPORT_LUNS_TIMEOUT (30*HZ)61 62/*63 * Prefix values for the SCSI id's (stored in sysfs name field)64 */65#define SCSI_UID_SER_NUM 'S'66#define SCSI_UID_UNKNOWN 'Z'67 68/*69 * Return values of some of the scanning functions.70 *71 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this72 * includes allocation or general failures preventing IO from being sent.73 *74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available75 * on the given LUN.76 *77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a78 * given LUN.79 */80#define SCSI_SCAN_NO_RESPONSE 081#define SCSI_SCAN_TARGET_PRESENT 182#define SCSI_SCAN_LUN_PRESENT 283 84static const char *scsi_null_device_strs = "nullnullnullnull";85 86#define MAX_SCSI_LUNS 51287 88static u64 max_scsi_luns = MAX_SCSI_LUNS;89 90module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);91MODULE_PARM_DESC(max_luns,92 "last scsi LUN (should be between 1 and 2^64-1)");93 94#ifdef CONFIG_SCSI_SCAN_ASYNC95#define SCSI_SCAN_TYPE_DEFAULT "async"96#else97#define SCSI_SCAN_TYPE_DEFAULT "sync"98#endif99 100static char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;101 102module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),103 S_IRUGO|S_IWUSR);104MODULE_PARM_DESC(scan, "sync, async, manual, or none. "105 "Setting to 'manual' disables automatic scanning, but allows "106 "for manual device scan via the 'scan' sysfs attribute.");107 108static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;109 110module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);111MODULE_PARM_DESC(inq_timeout, 112 "Timeout (in seconds) waiting for devices to answer INQUIRY."113 " Default is 20. Some devices may need more; most need less.");114 115/* This lock protects only this list */116static DEFINE_SPINLOCK(async_scan_lock);117static LIST_HEAD(scanning_hosts);118 119struct async_scan_data {120 struct list_head list;121 struct Scsi_Host *shost;122 struct completion prev_finished;123};124 125/*126 * scsi_enable_async_suspend - Enable async suspend and resume127 */128void scsi_enable_async_suspend(struct device *dev)129{130 /*131 * If a user has disabled async probing a likely reason is due to a132 * storage enclosure that does not inject staggered spin-ups. For133 * safety, make resume synchronous as well in that case.134 */135 if (strncmp(scsi_scan_type, "async", 5) != 0)136 return;137 /* Enable asynchronous suspend and resume. */138 device_enable_async_suspend(dev);139}140 141/**142 * scsi_complete_async_scans - Wait for asynchronous scans to complete143 *144 * When this function returns, any host which started scanning before145 * this function was called will have finished its scan. Hosts which146 * started scanning after this function was called may or may not have147 * finished.148 */149int scsi_complete_async_scans(void)150{151 struct async_scan_data *data;152 153 do {154 if (list_empty(&scanning_hosts))155 return 0;156 /* If we can't get memory immediately, that's OK. Just157 * sleep a little. Even if we never get memory, the async158 * scans will finish eventually.159 */160 data = kmalloc(sizeof(*data), GFP_KERNEL);161 if (!data)162 msleep(1);163 } while (!data);164 165 data->shost = NULL;166 init_completion(&data->prev_finished);167 168 spin_lock(&async_scan_lock);169 /* Check that there's still somebody else on the list */170 if (list_empty(&scanning_hosts))171 goto done;172 list_add_tail(&data->list, &scanning_hosts);173 spin_unlock(&async_scan_lock);174 175 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");176 wait_for_completion(&data->prev_finished);177 178 spin_lock(&async_scan_lock);179 list_del(&data->list);180 if (!list_empty(&scanning_hosts)) {181 struct async_scan_data *next = list_entry(scanning_hosts.next,182 struct async_scan_data, list);183 complete(&next->prev_finished);184 }185 done:186 spin_unlock(&async_scan_lock);187 188 kfree(data);189 return 0;190}191 192/**193 * scsi_unlock_floptical - unlock device via a special MODE SENSE command194 * @sdev: scsi device to send command to195 * @result: area to store the result of the MODE SENSE196 *197 * Description:198 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.199 * Called for BLIST_KEY devices.200 **/201static void scsi_unlock_floptical(struct scsi_device *sdev,202 unsigned char *result)203{204 unsigned char scsi_cmd[MAX_COMMAND_SIZE];205 206 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");207 scsi_cmd[0] = MODE_SENSE;208 scsi_cmd[1] = 0;209 scsi_cmd[2] = 0x2e;210 scsi_cmd[3] = 0;211 scsi_cmd[4] = 0x2a; /* size */212 scsi_cmd[5] = 0;213 scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, result, 0x2a,214 SCSI_TIMEOUT, 3, NULL);215}216 217static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,218 unsigned int depth)219{220 int new_shift = sbitmap_calculate_shift(depth);221 bool need_alloc = !sdev->budget_map.map;222 bool need_free = false;223 int ret;224 struct sbitmap sb_backup;225 226 depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev));227 228 /*229 * realloc if new shift is calculated, which is caused by setting230 * up one new default queue depth after calling ->device_configure231 */232 if (!need_alloc && new_shift != sdev->budget_map.shift)233 need_alloc = need_free = true;234 235 if (!need_alloc)236 return 0;237 238 /*239 * Request queue has to be frozen for reallocating budget map,240 * and here disk isn't added yet, so freezing is pretty fast241 */242 if (need_free) {243 blk_mq_freeze_queue(sdev->request_queue);244 sb_backup = sdev->budget_map;245 }246 ret = sbitmap_init_node(&sdev->budget_map,247 scsi_device_max_queue_depth(sdev),248 new_shift, GFP_KERNEL,249 sdev->request_queue->node, false, true);250 if (!ret)251 sbitmap_resize(&sdev->budget_map, depth);252 253 if (need_free) {254 if (ret)255 sdev->budget_map = sb_backup;256 else257 sbitmap_free(&sb_backup);258 ret = 0;259 blk_mq_unfreeze_queue(sdev->request_queue);260 }261 return ret;262}263 264/**265 * scsi_alloc_sdev - allocate and setup a scsi_Device266 * @starget: which target to allocate a &scsi_device for267 * @lun: which lun268 * @hostdata: usually NULL and set by ->slave_alloc instead269 *270 * Description:271 * Allocate, initialize for io, and return a pointer to a scsi_Device.272 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and273 * adds scsi_Device to the appropriate list.274 *275 * Return value:276 * scsi_Device pointer, or NULL on failure.277 **/278static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,279 u64 lun, void *hostdata)280{281 unsigned int depth;282 struct scsi_device *sdev;283 struct request_queue *q;284 int display_failure_msg = 1, ret;285 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);286 struct queue_limits lim;287 288 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,289 GFP_KERNEL);290 if (!sdev)291 goto out;292 293 sdev->vendor = scsi_null_device_strs;294 sdev->model = scsi_null_device_strs;295 sdev->rev = scsi_null_device_strs;296 sdev->host = shost;297 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;298 sdev->id = starget->id;299 sdev->lun = lun;300 sdev->channel = starget->channel;301 mutex_init(&sdev->state_mutex);302 sdev->sdev_state = SDEV_CREATED;303 INIT_LIST_HEAD(&sdev->siblings);304 INIT_LIST_HEAD(&sdev->same_target_siblings);305 INIT_LIST_HEAD(&sdev->starved_entry);306 INIT_LIST_HEAD(&sdev->event_list);307 spin_lock_init(&sdev->list_lock);308 mutex_init(&sdev->inquiry_mutex);309 INIT_WORK(&sdev->event_work, scsi_evt_thread);310 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);311 312 sdev->sdev_gendev.parent = get_device(&starget->dev);313 sdev->sdev_target = starget;314 315 /* usually NULL and set by ->slave_alloc instead */316 sdev->hostdata = hostdata;317 318 /* if the device needs this changing, it may do so in the319 * slave_configure function */320 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;321 322 /*323 * Some low level driver could use device->type324 */325 sdev->type = -1;326 327 /*328 * Assume that the device will have handshaking problems,329 * and then fix this field later if it turns out it330 * doesn't331 */332 sdev->borken = 1;333 334 sdev->sg_reserved_size = INT_MAX;335 336 scsi_init_limits(shost, &lim);337 q = blk_mq_alloc_queue(&sdev->host->tag_set, &lim, sdev);338 if (IS_ERR(q)) {339 /* release fn is set up in scsi_sysfs_device_initialise, so340 * have to free and put manually here */341 put_device(&starget->dev);342 kfree(sdev);343 goto out;344 }345 kref_get(&sdev->host->tagset_refcnt);346 sdev->request_queue = q;347 348 depth = sdev->host->cmd_per_lun ?: 1;349 350 /*351 * Use .can_queue as budget map's depth because we have to352 * support adjusting queue depth from sysfs. Meantime use353 * default device queue depth to figure out sbitmap shift354 * since we use this queue depth most of times.355 */356 if (scsi_realloc_sdev_budget_map(sdev, depth)) {357 put_device(&starget->dev);358 kfree(sdev);359 goto out;360 }361 362 scsi_change_queue_depth(sdev, depth);363 364 scsi_sysfs_device_initialize(sdev);365 366 if (shost->hostt->slave_alloc) {367 ret = shost->hostt->slave_alloc(sdev);368 if (ret) {369 /*370 * if LLDD reports slave not present, don't clutter371 * console with alloc failure messages372 */373 if (ret == -ENXIO)374 display_failure_msg = 0;375 goto out_device_destroy;376 }377 }378 379 return sdev;380 381out_device_destroy:382 __scsi_remove_device(sdev);383out:384 if (display_failure_msg)385 printk(ALLOC_FAILURE_MSG, __func__);386 return NULL;387}388 389static void scsi_target_destroy(struct scsi_target *starget)390{391 struct device *dev = &starget->dev;392 struct Scsi_Host *shost = dev_to_shost(dev->parent);393 unsigned long flags;394 395 BUG_ON(starget->state == STARGET_DEL);396 starget->state = STARGET_DEL;397 transport_destroy_device(dev);398 spin_lock_irqsave(shost->host_lock, flags);399 if (shost->hostt->target_destroy)400 shost->hostt->target_destroy(starget);401 list_del_init(&starget->siblings);402 spin_unlock_irqrestore(shost->host_lock, flags);403 put_device(dev);404}405 406static void scsi_target_dev_release(struct device *dev)407{408 struct device *parent = dev->parent;409 struct scsi_target *starget = to_scsi_target(dev);410 411 kfree(starget);412 put_device(parent);413}414 415static const struct device_type scsi_target_type = {416 .name = "scsi_target",417 .release = scsi_target_dev_release,418};419 420int scsi_is_target_device(const struct device *dev)421{422 return dev->type == &scsi_target_type;423}424EXPORT_SYMBOL(scsi_is_target_device);425 426static struct scsi_target *__scsi_find_target(struct device *parent,427 int channel, uint id)428{429 struct scsi_target *starget, *found_starget = NULL;430 struct Scsi_Host *shost = dev_to_shost(parent);431 /*432 * Search for an existing target for this sdev.433 */434 list_for_each_entry(starget, &shost->__targets, siblings) {435 if (starget->id == id &&436 starget->channel == channel) {437 found_starget = starget;438 break;439 }440 }441 if (found_starget)442 get_device(&found_starget->dev);443 444 return found_starget;445}446 447/**448 * scsi_target_reap_ref_release - remove target from visibility449 * @kref: the reap_ref in the target being released450 *451 * Called on last put of reap_ref, which is the indication that no device452 * under this target is visible anymore, so render the target invisible in453 * sysfs. Note: we have to be in user context here because the target reaps454 * should be done in places where the scsi device visibility is being removed.455 */456static void scsi_target_reap_ref_release(struct kref *kref)457{458 struct scsi_target *starget459 = container_of(kref, struct scsi_target, reap_ref);460 461 /*462 * if we get here and the target is still in a CREATED state that463 * means it was allocated but never made visible (because a scan464 * turned up no LUNs), so don't call device_del() on it.465 */466 if ((starget->state != STARGET_CREATED) &&467 (starget->state != STARGET_CREATED_REMOVE)) {468 transport_remove_device(&starget->dev);469 device_del(&starget->dev);470 }471 scsi_target_destroy(starget);472}473 474static void scsi_target_reap_ref_put(struct scsi_target *starget)475{476 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);477}478 479/**480 * scsi_alloc_target - allocate a new or find an existing target481 * @parent: parent of the target (need not be a scsi host)482 * @channel: target channel number (zero if no channels)483 * @id: target id number484 *485 * Return an existing target if one exists, provided it hasn't already486 * gone into STARGET_DEL state, otherwise allocate a new target.487 *488 * The target is returned with an incremented reference, so the caller489 * is responsible for both reaping and doing a last put490 */491static struct scsi_target *scsi_alloc_target(struct device *parent,492 int channel, uint id)493{494 struct Scsi_Host *shost = dev_to_shost(parent);495 struct device *dev = NULL;496 unsigned long flags;497 const int size = sizeof(struct scsi_target)498 + shost->transportt->target_size;499 struct scsi_target *starget;500 struct scsi_target *found_target;501 int error, ref_got;502 503 starget = kzalloc(size, GFP_KERNEL);504 if (!starget) {505 printk(KERN_ERR "%s: allocation failure\n", __func__);506 return NULL;507 }508 dev = &starget->dev;509 device_initialize(dev);510 kref_init(&starget->reap_ref);511 dev->parent = get_device(parent);512 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);513 dev->bus = &scsi_bus_type;514 dev->type = &scsi_target_type;515 scsi_enable_async_suspend(dev);516 starget->id = id;517 starget->channel = channel;518 starget->can_queue = 0;519 INIT_LIST_HEAD(&starget->siblings);520 INIT_LIST_HEAD(&starget->devices);521 starget->state = STARGET_CREATED;522 starget->scsi_level = SCSI_2;523 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;524 retry:525 spin_lock_irqsave(shost->host_lock, flags);526 527 found_target = __scsi_find_target(parent, channel, id);528 if (found_target)529 goto found;530 531 list_add_tail(&starget->siblings, &shost->__targets);532 spin_unlock_irqrestore(shost->host_lock, flags);533 /* allocate and add */534 transport_setup_device(dev);535 if (shost->hostt->target_alloc) {536 error = shost->hostt->target_alloc(starget);537 538 if(error) {539 if (error != -ENXIO)540 dev_err(dev, "target allocation failed, error %d\n", error);541 /* don't want scsi_target_reap to do the final542 * put because it will be under the host lock */543 scsi_target_destroy(starget);544 return NULL;545 }546 }547 get_device(dev);548 549 return starget;550 551 found:552 /*553 * release routine already fired if kref is zero, so if we can still554 * take the reference, the target must be alive. If we can't, it must555 * be dying and we need to wait for a new target556 */557 ref_got = kref_get_unless_zero(&found_target->reap_ref);558 559 spin_unlock_irqrestore(shost->host_lock, flags);560 if (ref_got) {561 put_device(dev);562 return found_target;563 }564 /*565 * Unfortunately, we found a dying target; need to wait until it's566 * dead before we can get a new one. There is an anomaly here. We567 * *should* call scsi_target_reap() to balance the kref_get() of the568 * reap_ref above. However, since the target being released, it's569 * already invisible and the reap_ref is irrelevant. If we call570 * scsi_target_reap() we might spuriously do another device_del() on571 * an already invisible target.572 */573 put_device(&found_target->dev);574 /*575 * length of time is irrelevant here, we just want to yield the CPU576 * for a tick to avoid busy waiting for the target to die.577 */578 msleep(1);579 goto retry;580}581 582/**583 * scsi_target_reap - check to see if target is in use and destroy if not584 * @starget: target to be checked585 *586 * This is used after removing a LUN or doing a last put of the target587 * it checks atomically that nothing is using the target and removes588 * it if so.589 */590void scsi_target_reap(struct scsi_target *starget)591{592 /*593 * serious problem if this triggers: STARGET_DEL is only set in the if594 * the reap_ref drops to zero, so we're trying to do another final put595 * on an already released kref596 */597 BUG_ON(starget->state == STARGET_DEL);598 scsi_target_reap_ref_put(starget);599}600 601/**602 * scsi_sanitize_inquiry_string - remove non-graphical chars from an603 * INQUIRY result string604 * @s: INQUIRY result string to sanitize605 * @len: length of the string606 *607 * Description:608 * The SCSI spec says that INQUIRY vendor, product, and revision609 * strings must consist entirely of graphic ASCII characters,610 * padded on the right with spaces. Since not all devices obey611 * this rule, we will replace non-graphic or non-ASCII characters612 * with spaces. Exception: a NUL character is interpreted as a613 * string terminator, so all the following characters are set to614 * spaces.615 **/616void scsi_sanitize_inquiry_string(unsigned char *s, int len)617{618 int terminated = 0;619 620 for (; len > 0; (--len, ++s)) {621 if (*s == 0)622 terminated = 1;623 if (terminated || *s < 0x20 || *s > 0x7e)624 *s = ' ';625 }626}627EXPORT_SYMBOL(scsi_sanitize_inquiry_string);628 629 630/**631 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY632 * @sdev: scsi_device to probe633 * @inq_result: area to store the INQUIRY result634 * @result_len: len of inq_result635 * @bflags: store any bflags found here636 *637 * Description:638 * Probe the lun associated with @req using a standard SCSI INQUIRY;639 *640 * If the INQUIRY is successful, zero is returned and the641 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length642 * are copied to the scsi_device any flags value is stored in *@bflags.643 **/644static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,645 int result_len, blist_flags_t *bflags)646{647 unsigned char scsi_cmd[MAX_COMMAND_SIZE];648 int first_inquiry_len, try_inquiry_len, next_inquiry_len;649 int response_len = 0;650 int pass, count, result, resid;651 struct scsi_failure failure_defs[] = {652 /*653 * not-ready to ready transition [asc/ascq=0x28/0x0] or654 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY655 * should not yield UNIT_ATTENTION but many buggy devices do656 * so anyway.657 */658 {659 .sense = UNIT_ATTENTION,660 .asc = 0x28,661 .result = SAM_STAT_CHECK_CONDITION,662 },663 {664 .sense = UNIT_ATTENTION,665 .asc = 0x29,666 .result = SAM_STAT_CHECK_CONDITION,667 },668 {669 .allowed = 1,670 .result = DID_TIME_OUT << 16,671 },672 {}673 };674 struct scsi_failures failures = {675 .total_allowed = 3,676 .failure_definitions = failure_defs,677 };678 const struct scsi_exec_args exec_args = {679 .resid = &resid,680 .failures = &failures,681 };682 683 *bflags = 0;684 685 /* Perform up to 3 passes. The first pass uses a conservative686 * transfer length of 36 unless sdev->inquiry_len specifies a687 * different value. */688 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;689 try_inquiry_len = first_inquiry_len;690 pass = 1;691 692 next_pass:693 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,694 "scsi scan: INQUIRY pass %d length %d\n",695 pass, try_inquiry_len));696 697 /* Each pass gets up to three chances to ignore Unit Attention */698 scsi_failures_reset_retries(&failures);699 700 for (count = 0; count < 3; ++count) {701 memset(scsi_cmd, 0, 6);702 scsi_cmd[0] = INQUIRY;703 scsi_cmd[4] = (unsigned char) try_inquiry_len;704 705 memset(inq_result, 0, try_inquiry_len);706 707 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,708 inq_result, try_inquiry_len,709 HZ / 2 + HZ * scsi_inq_timeout, 3,710 &exec_args);711 712 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,713 "scsi scan: INQUIRY %s with code 0x%x\n",714 result ? "failed" : "successful", result));715 716 if (result == 0) {717 /*718 * if nothing was transferred, we try719 * again. It's a workaround for some USB720 * devices.721 */722 if (resid == try_inquiry_len)723 continue;724 }725 break;726 }727 728 if (result == 0) {729 scsi_sanitize_inquiry_string(&inq_result[8], 8);730 scsi_sanitize_inquiry_string(&inq_result[16], 16);731 scsi_sanitize_inquiry_string(&inq_result[32], 4);732 733 response_len = inq_result[4] + 5;734 if (response_len > 255)735 response_len = first_inquiry_len; /* sanity */736 737 /*738 * Get any flags for this device.739 *740 * XXX add a bflags to scsi_device, and replace the741 * corresponding bit fields in scsi_device, so bflags742 * need not be passed as an argument.743 */744 *bflags = scsi_get_device_flags(sdev, &inq_result[8],745 &inq_result[16]);746 747 /* When the first pass succeeds we gain information about748 * what larger transfer lengths might work. */749 if (pass == 1) {750 if (BLIST_INQUIRY_36 & *bflags)751 next_inquiry_len = 36;752 /*753 * LLD specified a maximum sdev->inquiry_len754 * but device claims it has more data. Capping755 * the length only makes sense for legacy756 * devices. If a device supports SPC-4 (2014)757 * or newer, assume that it is safe to ask for758 * as much as the device says it supports.759 */760 else if (sdev->inquiry_len &&761 response_len > sdev->inquiry_len &&762 (inq_result[2] & 0x7) < 6) /* SPC-4 */763 next_inquiry_len = sdev->inquiry_len;764 else765 next_inquiry_len = response_len;766 767 /* If more data is available perform the second pass */768 if (next_inquiry_len > try_inquiry_len) {769 try_inquiry_len = next_inquiry_len;770 pass = 2;771 goto next_pass;772 }773 }774 775 } else if (pass == 2) {776 sdev_printk(KERN_INFO, sdev,777 "scsi scan: %d byte inquiry failed. "778 "Consider BLIST_INQUIRY_36 for this device\n",779 try_inquiry_len);780 781 /* If this pass failed, the third pass goes back and transfers782 * the same amount as we successfully got in the first pass. */783 try_inquiry_len = first_inquiry_len;784 pass = 3;785 goto next_pass;786 }787 788 /* If the last transfer attempt got an error, assume the789 * peripheral doesn't exist or is dead. */790 if (result)791 return -EIO;792 793 /* Don't report any more data than the device says is valid */794 sdev->inquiry_len = min(try_inquiry_len, response_len);795 796 /*797 * XXX Abort if the response length is less than 36? If less than798 * 32, the lookup of the device flags (above) could be invalid,799 * and it would be possible to take an incorrect action - we do800 * not want to hang because of a short INQUIRY. On the flip side,801 * if the device is spun down or becoming ready (and so it gives a802 * short INQUIRY), an abort here prevents any further use of the803 * device, including spin up.804 *805 * On the whole, the best approach seems to be to assume the first806 * 36 bytes are valid no matter what the device says. That's807 * better than copying < 36 bytes to the inquiry-result buffer808 * and displaying garbage for the Vendor, Product, or Revision809 * strings.810 */811 if (sdev->inquiry_len < 36) {812 if (!sdev->host->short_inquiry) {813 shost_printk(KERN_INFO, sdev->host,814 "scsi scan: INQUIRY result too short (%d),"815 " using 36\n", sdev->inquiry_len);816 sdev->host->short_inquiry = 1;817 }818 sdev->inquiry_len = 36;819 }820 821 /*822 * Related to the above issue:823 *824 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,825 * and if not ready, sent a START_STOP to start (maybe spin up) and826 * then send the INQUIRY again, since the INQUIRY can change after827 * a device is initialized.828 *829 * Ideally, start a device if explicitly asked to do so. This830 * assumes that a device is spun up on power on, spun down on831 * request, and then spun up on request.832 */833 834 /*835 * The scanning code needs to know the scsi_level, even if no836 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so837 * non-zero LUNs can be scanned.838 */839 sdev->scsi_level = inq_result[2] & 0x0f;840 if (sdev->scsi_level >= 2 ||841 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))842 sdev->scsi_level++;843 sdev->sdev_target->scsi_level = sdev->scsi_level;844 845 /*846 * If SCSI-2 or lower, and if the transport requires it,847 * store the LUN value in CDB[1].848 */849 sdev->lun_in_cdb = 0;850 if (sdev->scsi_level <= SCSI_2 &&851 sdev->scsi_level != SCSI_UNKNOWN &&852 !sdev->host->no_scsi2_lun_in_cdb)853 sdev->lun_in_cdb = 1;854 855 return 0;856}857 858/**859 * scsi_add_lun - allocate and fully initialze a scsi_device860 * @sdev: holds information to be stored in the new scsi_device861 * @inq_result: holds the result of a previous INQUIRY to the LUN862 * @bflags: black/white list flag863 * @async: 1 if this device is being scanned asynchronously864 *865 * Description:866 * Initialize the scsi_device @sdev. Optionally set fields based867 * on values in *@bflags.868 *869 * Return:870 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device871 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized872 **/873static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,874 blist_flags_t *bflags, int async)875{876 const struct scsi_host_template *hostt = sdev->host->hostt;877 struct queue_limits lim;878 int ret;879 880 /*881 * XXX do not save the inquiry, since it can change underneath us,882 * save just vendor/model/rev.883 *884 * Rather than save it and have an ioctl that retrieves the saved885 * value, have an ioctl that executes the same INQUIRY code used886 * in scsi_probe_lun, let user level programs doing INQUIRY887 * scanning run at their own risk, or supply a user level program888 * that can correctly scan.889 */890 891 /*892 * Copy at least 36 bytes of INQUIRY data, so that we don't893 * dereference unallocated memory when accessing the Vendor,894 * Product, and Revision strings. Badly behaved devices may set895 * the INQUIRY Additional Length byte to a small value, indicating896 * these strings are invalid, but often they contain plausible data897 * nonetheless. It doesn't matter if the device sent < 36 bytes898 * total, since scsi_probe_lun() initializes inq_result with 0s.899 */900 sdev->inquiry = kmemdup(inq_result,901 max_t(size_t, sdev->inquiry_len, 36),902 GFP_KERNEL);903 if (sdev->inquiry == NULL)904 return SCSI_SCAN_NO_RESPONSE;905 906 sdev->vendor = (char *) (sdev->inquiry + 8);907 sdev->model = (char *) (sdev->inquiry + 16);908 sdev->rev = (char *) (sdev->inquiry + 32);909 910 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {911 /*912 * sata emulation layer device. This is a hack to work around913 * the SATL power management specifications which state that914 * when the SATL detects the device has gone into standby915 * mode, it shall respond with NOT READY.916 */917 sdev->allow_restart = 1;918 }919 920 if (*bflags & BLIST_ISROM) {921 sdev->type = TYPE_ROM;922 sdev->removable = 1;923 } else {924 sdev->type = (inq_result[0] & 0x1f);925 sdev->removable = (inq_result[1] & 0x80) >> 7;926 927 /*928 * some devices may respond with wrong type for929 * well-known logical units. Force well-known type930 * to enumerate them correctly.931 */932 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {933 sdev_printk(KERN_WARNING, sdev,934 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",935 __func__, sdev->type, (unsigned int)sdev->lun);936 sdev->type = TYPE_WLUN;937 }938 939 }940 941 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {942 /* RBC and MMC devices can return SCSI-3 compliance and yet943 * still not support REPORT LUNS, so make them act as944 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is945 * specifically set */946 if ((*bflags & BLIST_REPORTLUN2) == 0)947 *bflags |= BLIST_NOREPORTLUN;948 }949 950 /*951 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI952 * spec says: The device server is capable of supporting the953 * specified peripheral device type on this logical unit. However,954 * the physical device is not currently connected to this logical955 * unit.956 *957 * The above is vague, as it implies that we could treat 001 and958 * 011 the same. Stay compatible with previous code, and create a959 * scsi_device for a PQ of 1960 *961 * Don't set the device offline here; rather let the upper962 * level drivers eval the PQ to decide whether they should963 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.964 */ 965 966 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;967 sdev->lockable = sdev->removable;968 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);969 970 if (sdev->scsi_level >= SCSI_3 ||971 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))972 sdev->ppr = 1;973 if (inq_result[7] & 0x60)974 sdev->wdtr = 1;975 if (inq_result[7] & 0x10)976 sdev->sdtr = 1;977 978 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "979 "ANSI: %d%s\n", scsi_device_type(sdev->type),980 sdev->vendor, sdev->model, sdev->rev,981 sdev->inq_periph_qual, inq_result[2] & 0x07,982 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");983 984 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&985 !(*bflags & BLIST_NOTQ)) {986 sdev->tagged_supported = 1;987 sdev->simple_tags = 1;988 }989 990 /*991 * Some devices (Texel CD ROM drives) have handshaking problems992 * when used with the Seagate controllers. borken is initialized993 * to 1, and then set it to 0 here.994 */995 if ((*bflags & BLIST_BORKEN) == 0)996 sdev->borken = 0;997 998 if (*bflags & BLIST_NO_ULD_ATTACH)999 sdev->no_uld_attach = 1;1000 1001 /*1002 * Apparently some really broken devices (contrary to the SCSI1003 * standards) need to be selected without asserting ATN1004 */1005 if (*bflags & BLIST_SELECT_NO_ATN)1006 sdev->select_no_atn = 1;1007 1008 /*1009 * Some devices may not want to have a start command automatically1010 * issued when a device is added.1011 */1012 if (*bflags & BLIST_NOSTARTONADD)1013 sdev->no_start_on_add = 1;1014 1015 if (*bflags & BLIST_SINGLELUN)1016 scsi_target(sdev)->single_lun = 1;1017 1018 sdev->use_10_for_rw = 1;1019 1020 /* some devices don't like REPORT SUPPORTED OPERATION CODES1021 * and will simply timeout causing sd_mod init to take a very1022 * very long time */1023 if (*bflags & BLIST_NO_RSOC)1024 sdev->no_report_opcodes = 1;1025 1026 /* set the device running here so that slave configure1027 * may do I/O */1028 mutex_lock(&sdev->state_mutex);1029 ret = scsi_device_set_state(sdev, SDEV_RUNNING);1030 if (ret)1031 ret = scsi_device_set_state(sdev, SDEV_BLOCK);1032 mutex_unlock(&sdev->state_mutex);1033 1034 if (ret) {1035 sdev_printk(KERN_ERR, sdev,1036 "in wrong state %s to complete scan\n",1037 scsi_device_state_name(sdev->sdev_state));1038 return SCSI_SCAN_NO_RESPONSE;1039 }1040 1041 if (*bflags & BLIST_NOT_LOCKABLE)1042 sdev->lockable = 0;1043 1044 if (*bflags & BLIST_RETRY_HWERROR)1045 sdev->retry_hwerror = 1;1046 1047 if (*bflags & BLIST_NO_DIF)1048 sdev->no_dif = 1;1049 1050 if (*bflags & BLIST_UNMAP_LIMIT_WS)1051 sdev->unmap_limit_for_ws = 1;1052 1053 if (*bflags & BLIST_IGN_MEDIA_CHANGE)1054 sdev->ignore_media_change = 1;1055 1056 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;1057 1058 if (*bflags & BLIST_TRY_VPD_PAGES)1059 sdev->try_vpd_pages = 1;1060 else if (*bflags & BLIST_SKIP_VPD_PAGES)1061 sdev->skip_vpd_pages = 1;1062 1063 if (*bflags & BLIST_NO_VPD_SIZE)1064 sdev->no_vpd_size = 1;1065 1066 transport_configure_device(&sdev->sdev_gendev);1067 1068 /*1069 * No need to freeze the queue as it isn't reachable to anyone else yet.1070 */1071 lim = queue_limits_start_update(sdev->request_queue);1072 if (*bflags & BLIST_MAX_512)1073 lim.max_hw_sectors = 512;1074 else if (*bflags & BLIST_MAX_1024)1075 lim.max_hw_sectors = 1024;1076 1077 if (hostt->device_configure)1078 ret = hostt->device_configure(sdev, &lim);1079 else if (hostt->slave_configure)1080 ret = hostt->slave_configure(sdev);1081 if (ret) {1082 queue_limits_cancel_update(sdev->request_queue);1083 /*1084 * If the LLDD reports device not present, don't clutter the1085 * console with failure messages.1086 */1087 if (ret != -ENXIO)1088 sdev_printk(KERN_ERR, sdev,1089 "failed to configure device\n");1090 return SCSI_SCAN_NO_RESPONSE;1091 }1092 1093 ret = queue_limits_commit_update(sdev->request_queue, &lim);1094 if (ret) {1095 sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n");1096 return SCSI_SCAN_NO_RESPONSE;1097 }1098 1099 /*1100 * The queue_depth is often changed in ->device_configure.1101 *1102 * Set up budget map again since memory consumption of the map depends1103 * on actual queue depth.1104 */1105 if (hostt->device_configure || hostt->slave_configure)1106 scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth);1107 1108 if (sdev->scsi_level >= SCSI_3)1109 scsi_attach_vpd(sdev);1110 1111 scsi_cdl_check(sdev);1112 1113 sdev->max_queue_depth = sdev->queue_depth;1114 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);1115 sdev->sdev_bflags = *bflags;1116 1117 /*1118 * Ok, the device is now all set up, we can1119 * register it and tell the rest of the kernel1120 * about it.1121 */1122 if (!async && scsi_sysfs_add_sdev(sdev) != 0)1123 return SCSI_SCAN_NO_RESPONSE;1124 1125 return SCSI_SCAN_LUN_PRESENT;1126}1127 1128#ifdef CONFIG_SCSI_LOGGING1129/** 1130 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace1131 * @buf: Output buffer with at least end-first+1 bytes of space1132 * @inq: Inquiry buffer (input)1133 * @first: Offset of string into inq1134 * @end: Index after last character in inq1135 */1136static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,1137 unsigned first, unsigned end)1138{1139 unsigned term = 0, idx;1140 1141 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {1142 if (inq[idx+first] > ' ') {1143 buf[idx] = inq[idx+first];1144 term = idx+1;1145 } else {1146 buf[idx] = ' ';1147 }1148 }1149 buf[term] = 0;1150 return buf;1151}1152#endif1153 1154/**1155 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it1156 * @starget: pointer to target device structure1157 * @lun: LUN of target device1158 * @bflagsp: store bflags here if not NULL1159 * @sdevp: probe the LUN corresponding to this scsi_device1160 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only1161 * needed on first scan1162 * @hostdata: passed to scsi_alloc_sdev()1163 *1164 * Description:1165 * Call scsi_probe_lun, if a LUN with an attached device is found,1166 * allocate and set it up by calling scsi_add_lun.1167 *1168 * Return:1169 *1170 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device1171 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is1172 * attached at the LUN1173 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized1174 **/1175static int scsi_probe_and_add_lun(struct scsi_target *starget,1176 u64 lun, blist_flags_t *bflagsp,1177 struct scsi_device **sdevp,1178 enum scsi_scan_mode rescan,1179 void *hostdata)1180{1181 struct scsi_device *sdev;1182 unsigned char *result;1183 blist_flags_t bflags;1184 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;1185 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);1186 1187 /*1188 * The rescan flag is used as an optimization, the first scan of a1189 * host adapter calls into here with rescan == 0.1190 */1191 sdev = scsi_device_lookup_by_target(starget, lun);1192 if (sdev) {1193 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {1194 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,1195 "scsi scan: device exists on %s\n",1196 dev_name(&sdev->sdev_gendev)));1197 if (sdevp)1198 *sdevp = sdev;1199 else1200 scsi_device_put(sdev);1201 1202 if (bflagsp)1203 *bflagsp = scsi_get_device_flags(sdev,1204 sdev->vendor,1205 sdev->model);1206 return SCSI_SCAN_LUN_PRESENT;1207 }1208 scsi_device_put(sdev);1209 } else1210 sdev = scsi_alloc_sdev(starget, lun, hostdata);1211 if (!sdev)1212 goto out;1213 1214 result = kmalloc(result_len, GFP_KERNEL);1215 if (!result)1216 goto out_free_sdev;1217 1218 if (scsi_probe_lun(sdev, result, result_len, &bflags))1219 goto out_free_result;1220 1221 if (bflagsp)1222 *bflagsp = bflags;1223 /*1224 * result contains valid SCSI INQUIRY data.1225 */1226 if ((result[0] >> 5) == 3) {1227 /*1228 * For a Peripheral qualifier 3 (011b), the SCSI1229 * spec says: The device server is not capable of1230 * supporting a physical device on this logical1231 * unit.1232 *1233 * For disks, this implies that there is no1234 * logical disk configured at sdev->lun, but there1235 * is a target id responding.1236 */1237 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"1238 " peripheral qualifier of 3, device not"1239 " added\n"))1240 if (lun == 0) {1241 SCSI_LOG_SCAN_BUS(1, {1242 unsigned char vend[9];1243 unsigned char mod[17];1244 1245 sdev_printk(KERN_INFO, sdev,1246 "scsi scan: consider passing scsi_mod."1247 "dev_flags=%s:%s:0x240 or 0x1000240\n",1248 scsi_inq_str(vend, result, 8, 16),1249 scsi_inq_str(mod, result, 16, 32));1250 });1251 1252 }1253 1254 res = SCSI_SCAN_TARGET_PRESENT;1255 goto out_free_result;1256 }1257 1258 /*1259 * Some targets may set slight variations of PQ and PDT to signal1260 * that no LUN is present, so don't add sdev in these cases.1261 * Two specific examples are:1262 * 1) NetApp targets: return PQ=1, PDT=0x1f1263 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"1264 * in the UFI 1.0 spec (we cannot rely on reserved bits).1265 *1266 * References:1267 * 1) SCSI SPC-3, pp. 145-1461268 * PQ=1: "A peripheral device having the specified peripheral1269 * device type is not connected to this logical unit. However, the1270 * device server is capable of supporting the specified peripheral1271 * device type on this logical unit."1272 * PDT=0x1f: "Unknown or no device type"1273 * 2) USB UFI 1.0, p. 201274 * PDT=00h Direct-access device (floppy)1275 * PDT=1Fh none (no FDD connected to the requested logical unit)1276 */1277 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&1278 (result[0] & 0x1f) == 0x1f &&1279 !scsi_is_wlun(lun)) {1280 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,1281 "scsi scan: peripheral device type"1282 " of 31, no device added\n"));1283 res = SCSI_SCAN_TARGET_PRESENT;1284 goto out_free_result;1285 }1286 1287 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);1288 if (res == SCSI_SCAN_LUN_PRESENT) {1289 if (bflags & BLIST_KEY) {1290 sdev->lockable = 0;1291 scsi_unlock_floptical(sdev, result);1292 }1293 }1294 1295 out_free_result:1296 kfree(result);1297 out_free_sdev:1298 if (res == SCSI_SCAN_LUN_PRESENT) {1299 if (sdevp) {1300 if (scsi_device_get(sdev) == 0) {1301 *sdevp = sdev;1302 } else {1303 __scsi_remove_device(sdev);1304 res = SCSI_SCAN_NO_RESPONSE;1305 }1306 }1307 } else1308 __scsi_remove_device(sdev);1309 out:1310 return res;1311}1312 1313/**1314 * scsi_sequential_lun_scan - sequentially scan a SCSI target1315 * @starget: pointer to target structure to scan1316 * @bflags: black/white list flag for LUN 01317 * @scsi_level: Which version of the standard does this device adhere to1318 * @rescan: passed to scsi_probe_add_lun()1319 *1320 * Description:1321 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been1322 * scanned) to some maximum lun until a LUN is found with no device1323 * attached. Use the bflags to figure out any oddities.1324 *1325 * Modifies sdevscan->lun.1326 **/1327static void scsi_sequential_lun_scan(struct scsi_target *starget,1328 blist_flags_t bflags, int scsi_level,1329 enum scsi_scan_mode rescan)1330{1331 uint max_dev_lun;1332 u64 sparse_lun, lun;1333 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);1334 1335 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,1336 "scsi scan: Sequential scan\n"));1337 1338 max_dev_lun = min(max_scsi_luns, shost->max_lun);1339 /*1340 * If this device is known to support sparse multiple units,1341 * override the other settings, and scan all of them. Normally,1342 * SCSI-3 devices should be scanned via the REPORT LUNS.1343 */1344 if (bflags & BLIST_SPARSELUN) {1345 max_dev_lun = shost->max_lun;1346 sparse_lun = 1;1347 } else1348 sparse_lun = 0;1349 1350 /*1351 * If less than SCSI_1_CCS, and no special lun scanning, stop1352 * scanning; this matches 2.4 behaviour, but could just be a bug1353 * (to continue scanning a SCSI_1_CCS device).1354 *1355 * This test is broken. We might not have any device on lun0 for1356 * a sparselun device, and if that's the case then how would we1357 * know the real scsi_level, eh? It might make sense to just not1358 * scan any SCSI_1 device for non-0 luns, but that check would best1359 * go into scsi_alloc_sdev() and just have it return null when asked1360 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.1361 *1362 if ((sdevscan->scsi_level < SCSI_1_CCS) &&1363 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))1364 == 0))1365 return;1366 */1367 /*1368 * If this device is known to support multiple units, override1369 * the other settings, and scan all of them.1370 */1371 if (bflags & BLIST_FORCELUN)1372 max_dev_lun = shost->max_lun;1373 /*1374 * REGAL CDC-4X: avoid hang after LUN 41375 */1376 if (bflags & BLIST_MAX5LUN)1377 max_dev_lun = min(5U, max_dev_lun);1378 /*1379 * Do not scan SCSI-2 or lower device past LUN 7, unless1380 * BLIST_LARGELUN.1381 */1382 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))1383 max_dev_lun = min(8U, max_dev_lun);1384 else1385 max_dev_lun = min(256U, max_dev_lun);1386 1387 /*1388 * We have already scanned LUN 0, so start at LUN 1. Keep scanning1389 * until we reach the max, or no LUN is found and we are not1390 * sparse_lun.1391 */1392 for (lun = 1; lun < max_dev_lun; ++lun)1393 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,1394 NULL) != SCSI_SCAN_LUN_PRESENT) &&1395 !sparse_lun)1396 return;1397}1398 1399/**1400 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results1401 * @starget: which target1402 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN1403 * @rescan: nonzero if we can skip code only needed on first scan1404 *1405 * Description:1406 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.1407 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.1408 *1409 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 81410 * LUNs even if it's older than SCSI-3.1411 * If BLIST_NOREPORTLUN is set, return 1 always.1412 * If BLIST_NOLUN is set, return 0 always.1413 * If starget->no_report_luns is set, return 1 always.1414 *1415 * Return:1416 * 0: scan completed (or no memory, so further scanning is futile)1417 * 1: could not scan with REPORT LUN1418 **/1419static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,1420 enum scsi_scan_mode rescan)1421{1422 unsigned char scsi_cmd[MAX_COMMAND_SIZE];1423 unsigned int length;1424 u64 lun;1425 unsigned int num_luns;1426 int result;1427 struct scsi_lun *lunp, *lun_data;1428 struct scsi_device *sdev;1429 struct Scsi_Host *shost = dev_to_shost(&starget->dev);1430 struct scsi_failure failure_defs[] = {1431 {1432 .sense = UNIT_ATTENTION,1433 .asc = SCMD_FAILURE_ASC_ANY,1434 .ascq = SCMD_FAILURE_ASCQ_ANY,1435 .result = SAM_STAT_CHECK_CONDITION,1436 },1437 /* Fail all CCs except the UA above */1438 {1439 .sense = SCMD_FAILURE_SENSE_ANY,1440 .result = SAM_STAT_CHECK_CONDITION,1441 },1442 /* Retry any other errors not listed above */1443 {1444 .result = SCMD_FAILURE_RESULT_ANY,1445 },1446 {}1447 };1448 struct scsi_failures failures = {1449 .total_allowed = 3,1450 .failure_definitions = failure_defs,1451 };1452 const struct scsi_exec_args exec_args = {1453 .failures = &failures,1454 };1455 int ret = 0;1456 1457 /*1458 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.1459 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does1460 * support more than 8 LUNs.1461 * Don't attempt if the target doesn't support REPORT LUNS.1462 */1463 if (bflags & BLIST_NOREPORTLUN)1464 return 1;1465 if (starget->scsi_level < SCSI_2 &&1466 starget->scsi_level != SCSI_UNKNOWN)1467 return 1;1468 if (starget->scsi_level < SCSI_3 &&1469 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))1470 return 1;1471 if (bflags & BLIST_NOLUN)1472 return 0;1473 if (starget->no_report_luns)1474 return 1;1475 1476 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {1477 sdev = scsi_alloc_sdev(starget, 0, NULL);1478 if (!sdev)1479 return 0;1480 if (scsi_device_get(sdev)) {1481 __scsi_remove_device(sdev);1482 return 0;1483 }1484 }1485 1486 /*1487 * Allocate enough to hold the header (the same size as one scsi_lun)1488 * plus the number of luns we are requesting. 511 was the default1489 * value of the now removed max_report_luns parameter.1490 */1491 length = (511 + 1) * sizeof(struct scsi_lun);1492retry:1493 lun_data = kmalloc(length, GFP_KERNEL);1494 if (!lun_data) {1495 printk(ALLOC_FAILURE_MSG, __func__);1496 goto out;1497 }1498 1499 scsi_cmd[0] = REPORT_LUNS;1500 1501 /*1502 * bytes 1 - 5: reserved, set to zero.1503 */1504 memset(&scsi_cmd[1], 0, 5);1505 1506 /*1507 * bytes 6 - 9: length of the command.1508 */1509 put_unaligned_be32(length, &scsi_cmd[6]);1510 1511 scsi_cmd[10] = 0; /* reserved */1512 scsi_cmd[11] = 0; /* control */1513 1514 /*1515 * We can get a UNIT ATTENTION, for example a power on/reset, so1516 * retry a few times (like sd.c does for TEST UNIT READY).1517 * Experience shows some combinations of adapter/devices get at1518 * least two power on/resets.1519 *1520 * Illegal requests (for devices that do not support REPORT LUNS)1521 * should come through as a check condition, and will not generate1522 * a retry.1523 */1524 scsi_failures_reset_retries(&failures);1525 1526 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,1527 "scsi scan: Sending REPORT LUNS\n"));1528 1529 result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data,1530 length, SCSI_REPORT_LUNS_TIMEOUT, 3,1531 &exec_args);1532 1533 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,1534 "scsi scan: REPORT LUNS %s result 0x%x\n",1535 result ? "failed" : "successful", result));1536 if (result) {1537 /*1538 * The device probably does not support a REPORT LUN command1539 */1540 ret = 1;1541 goto out_err;1542 }1543 1544 /*1545 * Get the length from the first four bytes of lun_data.1546 */1547 if (get_unaligned_be32(lun_data->scsi_lun) +1548 sizeof(struct scsi_lun) > length) {1549 length = get_unaligned_be32(lun_data->scsi_lun) +1550 sizeof(struct scsi_lun);1551 kfree(lun_data);1552 goto retry;1553 }1554 length = get_unaligned_be32(lun_data->scsi_lun);1555 1556 num_luns = (length / sizeof(struct scsi_lun));1557 1558 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,1559 "scsi scan: REPORT LUN scan\n"));1560 1561 /*1562 * Scan the luns in lun_data. The entry at offset 0 is really1563 * the header, so start at 1 and go up to and including num_luns.1564 */1565 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {1566 lun = scsilun_to_int(lunp);1567 1568 if (lun > sdev->host->max_lun) {1569 sdev_printk(KERN_WARNING, sdev,1570 "lun%llu has a LUN larger than"1571 " allowed by the host adapter\n", lun);1572 } else {1573 int res;1574 1575 res = scsi_probe_and_add_lun(starget,1576 lun, NULL, NULL, rescan, NULL);1577 if (res == SCSI_SCAN_NO_RESPONSE) {1578 /*1579 * Got some results, but now none, abort.1580 */1581 sdev_printk(KERN_ERR, sdev,1582 "Unexpected response"1583 " from lun %llu while scanning, scan"1584 " aborted\n", (unsigned long long)lun);1585 break;1586 }1587 }1588 }1589 1590 out_err:1591 kfree(lun_data);1592 out:1593 if (scsi_device_created(sdev))1594 /*1595 * the sdev we used didn't appear in the report luns scan1596 */1597 __scsi_remove_device(sdev);1598 scsi_device_put(sdev);1599 return ret;1600}1601 1602struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,1603 uint id, u64 lun, void *hostdata)1604{1605 struct scsi_device *sdev = ERR_PTR(-ENODEV);1606 struct device *parent = &shost->shost_gendev;1607 struct scsi_target *starget;1608 1609 if (strncmp(scsi_scan_type, "none", 4) == 0)1610 return ERR_PTR(-ENODEV);1611 1612 starget = scsi_alloc_target(parent, channel, id);1613 if (!starget)1614 return ERR_PTR(-ENOMEM);1615 scsi_autopm_get_target(starget);1616 1617 mutex_lock(&shost->scan_mutex);1618 if (!shost->async_scan)1619 scsi_complete_async_scans();1620 1621 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {1622 scsi_probe_and_add_lun(starget, lun, NULL, &sdev,1623 SCSI_SCAN_RESCAN, hostdata);1624 scsi_autopm_put_host(shost);1625 }1626 mutex_unlock(&shost->scan_mutex);1627 scsi_autopm_put_target(starget);1628 /*1629 * paired with scsi_alloc_target(). Target will be destroyed unless1630 * scsi_probe_and_add_lun made an underlying device visible1631 */1632 scsi_target_reap(starget);1633 put_device(&starget->dev);1634 1635 return sdev;1636}1637EXPORT_SYMBOL(__scsi_add_device);1638 1639int scsi_add_device(struct Scsi_Host *host, uint channel,1640 uint target, u64 lun)1641{1642 struct scsi_device *sdev = 1643 __scsi_add_device(host, channel, target, lun, NULL);1644 if (IS_ERR(sdev))1645 return PTR_ERR(sdev);1646 1647 scsi_device_put(sdev);1648 return 0;1649}1650EXPORT_SYMBOL(scsi_add_device);1651 1652int scsi_resume_device(struct scsi_device *sdev)1653{1654 struct device *dev = &sdev->sdev_gendev;1655 int ret = 0;1656 1657 device_lock(dev);1658 1659 /*1660 * Bail out if the device or its queue are not running. Otherwise,1661 * the rescan may block waiting for commands to be executed, with us1662 * holding the device lock. This can result in a potential deadlock1663 * in the power management core code when system resume is on-going.1664 */1665 if (sdev->sdev_state != SDEV_RUNNING ||1666 blk_queue_pm_only(sdev->request_queue)) {1667 ret = -EWOULDBLOCK;1668 goto unlock;1669 }1670 1671 if (dev->driver && try_module_get(dev->driver->owner)) {1672 struct scsi_driver *drv = to_scsi_driver(dev->driver);1673 1674 if (drv->resume)1675 ret = drv->resume(dev);1676 module_put(dev->driver->owner);1677 }1678 1679unlock:1680 device_unlock(dev);1681 1682 return ret;1683}1684EXPORT_SYMBOL(scsi_resume_device);1685 1686int scsi_rescan_device(struct scsi_device *sdev)1687{1688 struct device *dev = &sdev->sdev_gendev;1689 int ret = 0;1690 1691 device_lock(dev);1692 1693 /*1694 * Bail out if the device or its queue are not running. Otherwise,1695 * the rescan may block waiting for commands to be executed, with us1696 * holding the device lock. This can result in a potential deadlock1697 * in the power management core code when system resume is on-going.1698 */1699 if (sdev->sdev_state != SDEV_RUNNING ||1700 blk_queue_pm_only(sdev->request_queue)) {1701 ret = -EWOULDBLOCK;1702 goto unlock;1703 }1704 1705 scsi_attach_vpd(sdev);1706 scsi_cdl_check(sdev);1707 1708 if (sdev->handler && sdev->handler->rescan)1709 sdev->handler->rescan(sdev);1710 1711 if (dev->driver && try_module_get(dev->driver->owner)) {1712 struct scsi_driver *drv = to_scsi_driver(dev->driver);1713 1714 if (drv->rescan)1715 drv->rescan(dev);1716 module_put(dev->driver->owner);1717 }1718 1719unlock:1720 device_unlock(dev);1721 1722 return ret;1723}1724EXPORT_SYMBOL(scsi_rescan_device);1725 1726static void __scsi_scan_target(struct device *parent, unsigned int channel,1727 unsigned int id, u64 lun, enum scsi_scan_mode rescan)1728{1729 struct Scsi_Host *shost = dev_to_shost(parent);1730 blist_flags_t bflags = 0;1731 int res;1732 struct scsi_target *starget;1733 1734 if (shost->this_id == id)1735 /*1736 * Don't scan the host adapter1737 */1738 return;1739 1740 starget = scsi_alloc_target(parent, channel, id);1741 if (!starget)1742 return;1743 scsi_autopm_get_target(starget);1744 1745 if (lun != SCAN_WILD_CARD) {1746 /*1747 * Scan for a specific host/chan/id/lun.1748 */1749 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);1750 goto out_reap;1751 }1752 1753 /*1754 * Scan LUN 0, if there is some response, scan further. Ideally, we1755 * would not configure LUN 0 until all LUNs are scanned.1756 */1757 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);1758 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {1759 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)1760 /*1761 * The REPORT LUN did not scan the target,1762 * do a sequential scan.1763 */1764 scsi_sequential_lun_scan(starget, bflags,1765 starget->scsi_level, rescan);1766 }1767 1768 out_reap:1769 scsi_autopm_put_target(starget);1770 /*1771 * paired with scsi_alloc_target(): determine if the target has1772 * any children at all and if not, nuke it1773 */1774 scsi_target_reap(starget);1775 1776 put_device(&starget->dev);1777}1778 1779/**1780 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.1781 * @parent: host to scan1782 * @channel: channel to scan1783 * @id: target id to scan1784 * @lun: Specific LUN to scan or SCAN_WILD_CARD1785 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for1786 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,1787 * and SCSI_SCAN_MANUAL to force scanning even if1788 * 'scan=manual' is set.1789 *1790 * Description:1791 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,1792 * and possibly all LUNs on the target id.1793 *1794 * First try a REPORT LUN scan, if that does not scan the target, do a1795 * sequential scan of LUNs on the target id.1796 **/1797void scsi_scan_target(struct device *parent, unsigned int channel,1798 unsigned int id, u64 lun, enum scsi_scan_mode rescan)1799{1800 struct Scsi_Host *shost = dev_to_shost(parent);1801 1802 if (strncmp(scsi_scan_type, "none", 4) == 0)1803 return;1804 1805 if (rescan != SCSI_SCAN_MANUAL &&1806 strncmp(scsi_scan_type, "manual", 6) == 0)1807 return;1808 1809 mutex_lock(&shost->scan_mutex);1810 if (!shost->async_scan)1811 scsi_complete_async_scans();1812 1813 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {1814 __scsi_scan_target(parent, channel, id, lun, rescan);1815 scsi_autopm_put_host(shost);1816 }1817 mutex_unlock(&shost->scan_mutex);1818}1819EXPORT_SYMBOL(scsi_scan_target);1820 1821static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,1822 unsigned int id, u64 lun,1823 enum scsi_scan_mode rescan)1824{1825 uint order_id;1826 1827 if (id == SCAN_WILD_CARD)1828 for (id = 0; id < shost->max_id; ++id) {1829 /*1830 * XXX adapter drivers when possible (FCP, iSCSI)1831 * could modify max_id to match the current max,1832 * not the absolute max.1833 *1834 * XXX add a shost id iterator, so for example,1835 * the FC ID can be the same as a target id1836 * without a huge overhead of sparse id's.1837 */1838 if (shost->reverse_ordering)1839 /*1840 * Scan from high to low id.1841 */1842 order_id = shost->max_id - id - 1;1843 else1844 order_id = id;1845 __scsi_scan_target(&shost->shost_gendev, channel,1846 order_id, lun, rescan);1847 }1848 else1849 __scsi_scan_target(&shost->shost_gendev, channel,1850 id, lun, rescan);1851}1852 1853int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,1854 unsigned int id, u64 lun,1855 enum scsi_scan_mode rescan)1856{1857 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,1858 "%s: <%u:%u:%llu>\n",1859 __func__, channel, id, lun));1860 1861 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||1862 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||1863 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))1864 return -EINVAL;1865 1866 mutex_lock(&shost->scan_mutex);1867 if (!shost->async_scan)1868 scsi_complete_async_scans();1869 1870 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {1871 if (channel == SCAN_WILD_CARD)1872 for (channel = 0; channel <= shost->max_channel;1873 channel++)1874 scsi_scan_channel(shost, channel, id, lun,1875 rescan);1876 else1877 scsi_scan_channel(shost, channel, id, lun, rescan);1878 scsi_autopm_put_host(shost);1879 }1880 mutex_unlock(&shost->scan_mutex);1881 1882 return 0;1883}1884 1885static void scsi_sysfs_add_devices(struct Scsi_Host *shost)1886{1887 struct scsi_device *sdev;1888 shost_for_each_device(sdev, shost) {1889 /* target removed before the device could be added */1890 if (sdev->sdev_state == SDEV_DEL)1891 continue;1892 /* If device is already visible, skip adding it to sysfs */1893 if (sdev->is_visible)1894 continue;1895 if (!scsi_host_scan_allowed(shost) ||1896 scsi_sysfs_add_sdev(sdev) != 0)1897 __scsi_remove_device(sdev);1898 }1899}1900 1901/**1902 * scsi_prep_async_scan - prepare for an async scan1903 * @shost: the host which will be scanned1904 * Returns: a cookie to be passed to scsi_finish_async_scan()1905 *1906 * Tells the midlayer this host is going to do an asynchronous scan.1907 * It reserves the host's position in the scanning list and ensures1908 * that other asynchronous scans started after this one won't affect the1909 * ordering of the discovered devices.1910 */1911static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)1912{1913 struct async_scan_data *data = NULL;1914 unsigned long flags;1915 1916 if (strncmp(scsi_scan_type, "sync", 4) == 0)1917 return NULL;1918 1919 mutex_lock(&shost->scan_mutex);1920 if (shost->async_scan) {1921 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);1922 goto err;1923 }1924 1925 data = kmalloc(sizeof(*data), GFP_KERNEL);1926 if (!data)1927 goto err;1928 data->shost = scsi_host_get(shost);1929 if (!data->shost)1930 goto err;1931 init_completion(&data->prev_finished);1932 1933 spin_lock_irqsave(shost->host_lock, flags);1934 shost->async_scan = 1;1935 spin_unlock_irqrestore(shost->host_lock, flags);1936 mutex_unlock(&shost->scan_mutex);1937 1938 spin_lock(&async_scan_lock);1939 if (list_empty(&scanning_hosts))1940 complete(&data->prev_finished);1941 list_add_tail(&data->list, &scanning_hosts);1942 spin_unlock(&async_scan_lock);1943 1944 return data;1945 1946 err:1947 mutex_unlock(&shost->scan_mutex);1948 kfree(data);1949 return NULL;1950}1951 1952/**1953 * scsi_finish_async_scan - asynchronous scan has finished1954 * @data: cookie returned from earlier call to scsi_prep_async_scan()1955 *1956 * All the devices currently attached to this host have been found.1957 * This function announces all the devices it has found to the rest1958 * of the system.1959 */1960static void scsi_finish_async_scan(struct async_scan_data *data)1961{1962 struct Scsi_Host *shost;1963 unsigned long flags;1964 1965 if (!data)1966 return;1967 1968 shost = data->shost;1969 1970 mutex_lock(&shost->scan_mutex);1971 1972 if (!shost->async_scan) {1973 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);1974 dump_stack();1975 mutex_unlock(&shost->scan_mutex);1976 return;1977 }1978 1979 wait_for_completion(&data->prev_finished);1980 1981 scsi_sysfs_add_devices(shost);1982 1983 spin_lock_irqsave(shost->host_lock, flags);1984 shost->async_scan = 0;1985 spin_unlock_irqrestore(shost->host_lock, flags);1986 1987 mutex_unlock(&shost->scan_mutex);1988 1989 spin_lock(&async_scan_lock);1990 list_del(&data->list);1991 if (!list_empty(&scanning_hosts)) {1992 struct async_scan_data *next = list_entry(scanning_hosts.next,1993 struct async_scan_data, list);1994 complete(&next->prev_finished);1995 }1996 spin_unlock(&async_scan_lock);1997 1998 scsi_autopm_put_host(shost);1999 scsi_host_put(shost);2000 kfree(data);2001}2002 2003static void do_scsi_scan_host(struct Scsi_Host *shost)2004{2005 if (shost->hostt->scan_finished) {2006 unsigned long start = jiffies;2007 if (shost->hostt->scan_start)2008 shost->hostt->scan_start(shost);2009 2010 while (!shost->hostt->scan_finished(shost, jiffies - start))2011 msleep(10);2012 } else {2013 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,2014 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);2015 }2016}2017 2018static void do_scan_async(void *_data, async_cookie_t c)2019{2020 struct async_scan_data *data = _data;2021 struct Scsi_Host *shost = data->shost;2022 2023 do_scsi_scan_host(shost);2024 scsi_finish_async_scan(data);2025}2026 2027/**2028 * scsi_scan_host - scan the given adapter2029 * @shost: adapter to scan2030 **/2031void scsi_scan_host(struct Scsi_Host *shost)2032{2033 struct async_scan_data *data;2034 2035 if (strncmp(scsi_scan_type, "none", 4) == 0 ||2036 strncmp(scsi_scan_type, "manual", 6) == 0)2037 return;2038 if (scsi_autopm_get_host(shost) < 0)2039 return;2040 2041 data = scsi_prep_async_scan(shost);2042 if (!data) {2043 do_scsi_scan_host(shost);2044 scsi_autopm_put_host(shost);2045 return;2046 }2047 2048 /* register with the async subsystem so wait_for_device_probe()2049 * will flush this work2050 */2051 async_schedule(do_scan_async, data);2052 2053 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */2054}2055EXPORT_SYMBOL(scsi_scan_host);2056 2057void scsi_forget_host(struct Scsi_Host *shost)2058{2059 struct scsi_device *sdev;2060 unsigned long flags;2061 2062 restart:2063 spin_lock_irqsave(shost->host_lock, flags);2064 list_for_each_entry(sdev, &shost->__devices, siblings) {2065 if (sdev->sdev_state == SDEV_DEL)2066 continue;2067 spin_unlock_irqrestore(shost->host_lock, flags);2068 __scsi_remove_device(sdev);2069 goto restart;2070 }2071 spin_unlock_irqrestore(shost->host_lock, flags);2072}2073 2074