1// SPDX-License-Identifier: GPL-2.0
2/*
3 * scsi_scan.c
4 *
5 * Copyright (C) 2000 Eric Youngdale,
6 * Copyright (C) 2002 Patrick Mansfield
7 *
8 * The general scanning/probing algorithm is as follows, exceptions are
9 * made to it depending on device specific flags, compilation options, and
10 * global variable (boot or module load time) settings.
11 *
12 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
13 * 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 no
18 * device or storage attached to LUN 0):
19 *
20 * If LUN 0 has a device attached, allocate and setup a
21 * scsi_device for it.
22 *
23 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
24 * 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 timeout
58 */
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, this
72 * includes allocation or general failures preventing IO from being sent.
73 *
74 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
75 * on the given LUN.
76 *
77 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
78 * given LUN.
79 */
80#define SCSI_SCAN_NO_RESPONSE 0
81#define SCSI_SCAN_TARGET_PRESENT 1
82#define SCSI_SCAN_LUN_PRESENT 2
83
84static const char *scsi_null_device_strs = "nullnullnullnull";
85
86#define MAX_SCSI_LUNS 512
87
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_ASYNC
95#define SCSI_SCAN_TYPE_DEFAULT "async"
96#else
97#define SCSI_SCAN_TYPE_DEFAULT "sync"
98#endif
99
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 resume
127 */
128void scsi_enable_async_suspend(struct device *dev)
129{
130 /*
131 * If a user has disabled async probing a likely reason is due to a
132 * storage enclosure that does not inject staggered spin-ups. For
133 * 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 complete
143 *
144 * When this function returns, any host which started scanning before
145 * this function was called will have finished its scan. Hosts which
146 * started scanning after this function was called may or may not have
147 * finished.
148 */
149int scsi_complete_async_scans(void)
150{
151 struct async_scan_data *data;
152
153 do {
154 scoped_guard(spinlock, &async_scan_lock)
155 if (list_empty(head: &scanning_hosts))
156 return 0;
157 /* If we can't get memory immediately, that's OK. Just
158 * sleep a little. Even if we never get memory, the async
159 * scans will finish eventually.
160 */
161 data = kmalloc(sizeof(*data), GFP_KERNEL);
162 if (!data)
163 msleep(msecs: 1);
164 } while (!data);
165
166 data->shost = NULL;
167 init_completion(x: &data->prev_finished);
168
169 spin_lock(lock: &async_scan_lock);
170 /* Check that there's still somebody else on the list */
171 if (list_empty(head: &scanning_hosts))
172 goto done;
173 list_add_tail(new: &data->list, head: &scanning_hosts);
174 spin_unlock(lock: &async_scan_lock);
175
176 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
177 wait_for_completion(&data->prev_finished);
178
179 spin_lock(lock: &async_scan_lock);
180 list_del(entry: &data->list);
181 if (!list_empty(head: &scanning_hosts)) {
182 struct async_scan_data *next = list_entry(scanning_hosts.next,
183 struct async_scan_data, list);
184 complete(&next->prev_finished);
185 }
186 done:
187 spin_unlock(lock: &async_scan_lock);
188
189 kfree(objp: data);
190 return 0;
191}
192
193/**
194 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
195 * @sdev: scsi device to send command to
196 * @result: area to store the result of the MODE SENSE
197 *
198 * Description:
199 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
200 * Called for BLIST_KEY devices.
201 **/
202static void scsi_unlock_floptical(struct scsi_device *sdev,
203 unsigned char *result)
204{
205 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
206
207 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
208 scsi_cmd[0] = MODE_SENSE;
209 scsi_cmd[1] = 0;
210 scsi_cmd[2] = 0x2e;
211 scsi_cmd[3] = 0;
212 scsi_cmd[4] = 0x2a; /* size */
213 scsi_cmd[5] = 0;
214 scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN, buffer: result, bufflen: 0x2a,
215 SCSI_TIMEOUT, retries: 3, NULL);
216}
217
218static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev,
219 unsigned int depth)
220{
221 int new_shift = sbitmap_calculate_shift(depth);
222 bool need_alloc = !sdev->budget_map.map;
223 bool need_free = false;
224 unsigned int memflags;
225 int ret;
226 struct sbitmap sb_backup;
227
228 depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev));
229
230 /*
231 * realloc if new shift is calculated, which is caused by setting
232 * up one new default queue depth after calling ->sdev_configure
233 */
234 if (!need_alloc && new_shift != sdev->budget_map.shift)
235 need_alloc = need_free = true;
236
237 if (!need_alloc)
238 return 0;
239
240 /*
241 * Request queue has to be frozen for reallocating budget map,
242 * and here disk isn't added yet, so freezing is pretty fast
243 */
244 if (need_free) {
245 memflags = blk_mq_freeze_queue(q: sdev->request_queue);
246 sb_backup = sdev->budget_map;
247 }
248 ret = sbitmap_init_node(sb: &sdev->budget_map,
249 depth: scsi_device_max_queue_depth(sdev),
250 shift: new_shift, GFP_NOIO,
251 node: sdev->request_queue->node, round_robin: false, alloc_hint: true);
252 if (!ret)
253 sbitmap_resize(sb: &sdev->budget_map, depth);
254
255 if (need_free) {
256 if (ret)
257 sdev->budget_map = sb_backup;
258 else
259 sbitmap_free(sb: &sb_backup);
260 ret = 0;
261 blk_mq_unfreeze_queue(q: sdev->request_queue, memflags);
262 }
263 return ret;
264}
265
266/**
267 * scsi_alloc_sdev - allocate and setup a scsi_Device
268 * @starget: which target to allocate a &scsi_device for
269 * @lun: which lun
270 * @hostdata: usually NULL and set by ->sdev_init instead
271 *
272 * Description:
273 * Allocate, initialize for io, and return a pointer to a scsi_Device.
274 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
275 * adds scsi_Device to the appropriate list.
276 *
277 * Return value:
278 * scsi_Device pointer, or NULL on failure.
279 **/
280static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
281 u64 lun, void *hostdata)
282{
283 unsigned int depth;
284 struct scsi_device *sdev;
285 struct request_queue *q;
286 int display_failure_msg = 1, ret;
287 struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent);
288 struct queue_limits lim;
289
290 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
291 GFP_KERNEL);
292 if (!sdev)
293 goto out;
294
295 sdev->vendor = scsi_null_device_strs;
296 sdev->model = scsi_null_device_strs;
297 sdev->rev = scsi_null_device_strs;
298 sdev->host = shost;
299 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
300 sdev->id = starget->id;
301 sdev->lun = lun;
302 sdev->channel = starget->channel;
303 mutex_init(&sdev->state_mutex);
304 sdev->sdev_state = SDEV_CREATED;
305 INIT_LIST_HEAD(list: &sdev->siblings);
306 INIT_LIST_HEAD(list: &sdev->same_target_siblings);
307 INIT_LIST_HEAD(list: &sdev->starved_entry);
308 INIT_LIST_HEAD(list: &sdev->event_list);
309 spin_lock_init(&sdev->list_lock);
310 mutex_init(&sdev->inquiry_mutex);
311 INIT_WORK(&sdev->event_work, scsi_evt_thread);
312 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
313
314 sdev->sdev_gendev.parent = get_device(dev: &starget->dev);
315 sdev->sdev_target = starget;
316
317 /* usually NULL and set by ->sdev_init instead */
318 sdev->hostdata = hostdata;
319
320 /* if the device needs this changing, it may do so in the
321 * sdev_configure function */
322 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
323
324 /*
325 * Some low level driver could use device->type
326 */
327 sdev->type = -1;
328
329 /*
330 * Assume that the device will have handshaking problems,
331 * and then fix this field later if it turns out it
332 * doesn't
333 */
334 sdev->borken = 1;
335
336 sdev->sg_reserved_size = INT_MAX;
337
338 scsi_init_limits(shost, lim: &lim);
339 q = blk_mq_alloc_queue(set: &sdev->host->tag_set, lim: &lim, queuedata: sdev);
340 if (IS_ERR(ptr: q)) {
341 /* release fn is set up in scsi_sysfs_device_initialise, so
342 * have to free and put manually here */
343 put_device(dev: &starget->dev);
344 kfree(objp: sdev);
345 goto out;
346 }
347 kref_get(kref: &sdev->host->tagset_refcnt);
348 sdev->request_queue = q;
349
350 depth = sdev->host->cmd_per_lun ?: 1;
351
352 /*
353 * Use .can_queue as budget map's depth because we have to
354 * support adjusting queue depth from sysfs. Meantime use
355 * default device queue depth to figure out sbitmap shift
356 * since we use this queue depth most of times.
357 */
358 if (scsi_realloc_sdev_budget_map(sdev, depth)) {
359 put_device(dev: &starget->dev);
360 kfree(objp: sdev);
361 goto out;
362 }
363
364 scsi_change_queue_depth(sdev, depth);
365
366 scsi_sysfs_device_initialize(sdev);
367
368 if (shost->hostt->sdev_init) {
369 ret = shost->hostt->sdev_init(sdev);
370 if (ret) {
371 /*
372 * if LLDD reports slave not present, don't clutter
373 * console with alloc failure messages
374 */
375 if (ret == -ENXIO)
376 display_failure_msg = 0;
377 goto out_device_destroy;
378 }
379 }
380
381 return sdev;
382
383out_device_destroy:
384 __scsi_remove_device(sdev);
385out:
386 if (display_failure_msg)
387 printk(ALLOC_FAILURE_MSG, __func__);
388 return NULL;
389}
390
391static void scsi_target_destroy(struct scsi_target *starget)
392{
393 struct device *dev = &starget->dev;
394 struct Scsi_Host *shost = dev_to_shost(dev: dev->parent);
395 unsigned long flags;
396
397 BUG_ON(starget->state == STARGET_DEL);
398 starget->state = STARGET_DEL;
399 transport_destroy_device(dev);
400 spin_lock_irqsave(shost->host_lock, flags);
401 if (shost->hostt->target_destroy)
402 shost->hostt->target_destroy(starget);
403 list_del_init(entry: &starget->siblings);
404 spin_unlock_irqrestore(lock: shost->host_lock, flags);
405 put_device(dev);
406}
407
408static void scsi_target_dev_release(struct device *dev)
409{
410 struct device *parent = dev->parent;
411 struct scsi_target *starget = to_scsi_target(dev);
412
413 kfree(objp: starget);
414 put_device(dev: parent);
415}
416
417static const struct device_type scsi_target_type = {
418 .name = "scsi_target",
419 .release = scsi_target_dev_release,
420};
421
422int scsi_is_target_device(const struct device *dev)
423{
424 return dev->type == &scsi_target_type;
425}
426EXPORT_SYMBOL(scsi_is_target_device);
427
428static struct scsi_target *__scsi_find_target(struct device *parent,
429 int channel, uint id)
430{
431 struct scsi_target *starget, *found_starget = NULL;
432 struct Scsi_Host *shost = dev_to_shost(dev: parent);
433 /*
434 * Search for an existing target for this sdev.
435 */
436 list_for_each_entry(starget, &shost->__targets, siblings) {
437 if (starget->id == id &&
438 starget->channel == channel) {
439 found_starget = starget;
440 break;
441 }
442 }
443 if (found_starget)
444 get_device(dev: &found_starget->dev);
445
446 return found_starget;
447}
448
449/**
450 * scsi_target_reap_ref_release - remove target from visibility
451 * @kref: the reap_ref in the target being released
452 *
453 * Called on last put of reap_ref, which is the indication that no device
454 * under this target is visible anymore, so render the target invisible in
455 * sysfs. Note: we have to be in user context here because the target reaps
456 * should be done in places where the scsi device visibility is being removed.
457 */
458static void scsi_target_reap_ref_release(struct kref *kref)
459{
460 struct scsi_target *starget
461 = container_of(kref, struct scsi_target, reap_ref);
462
463 /*
464 * if we get here and the target is still in a CREATED state that
465 * means it was allocated but never made visible (because a scan
466 * turned up no LUNs), so don't call device_del() on it.
467 */
468 if ((starget->state != STARGET_CREATED) &&
469 (starget->state != STARGET_CREATED_REMOVE)) {
470 transport_remove_device(&starget->dev);
471 device_del(dev: &starget->dev);
472 }
473 scsi_target_destroy(starget);
474}
475
476static void scsi_target_reap_ref_put(struct scsi_target *starget)
477{
478 kref_put(kref: &starget->reap_ref, release: scsi_target_reap_ref_release);
479}
480
481/**
482 * scsi_alloc_target - allocate a new or find an existing target
483 * @parent: parent of the target (need not be a scsi host)
484 * @channel: target channel number (zero if no channels)
485 * @id: target id number
486 *
487 * Return an existing target if one exists, provided it hasn't already
488 * gone into STARGET_DEL state, otherwise allocate a new target.
489 *
490 * The target is returned with an incremented reference, so the caller
491 * is responsible for both reaping and doing a last put
492 */
493static struct scsi_target *scsi_alloc_target(struct device *parent,
494 int channel, uint id)
495{
496 struct Scsi_Host *shost = dev_to_shost(dev: parent);
497 struct device *dev = NULL;
498 unsigned long flags;
499 const int size = sizeof(struct scsi_target)
500 + shost->transportt->target_size;
501 struct scsi_target *starget;
502 struct scsi_target *found_target;
503 int error, ref_got;
504
505 starget = kzalloc(size, GFP_KERNEL);
506 if (!starget) {
507 printk(KERN_ERR "%s: allocation failure\n", __func__);
508 return NULL;
509 }
510 dev = &starget->dev;
511 device_initialize(dev);
512 kref_init(kref: &starget->reap_ref);
513 dev->parent = get_device(dev: parent);
514 dev_set_name(dev, name: "target%d:%d:%d", shost->host_no, channel, id);
515 dev->bus = &scsi_bus_type;
516 dev->type = &scsi_target_type;
517 scsi_enable_async_suspend(dev);
518 starget->id = id;
519 starget->channel = channel;
520 starget->can_queue = 0;
521 INIT_LIST_HEAD(list: &starget->siblings);
522 INIT_LIST_HEAD(list: &starget->devices);
523 starget->state = STARGET_CREATED;
524 starget->scsi_level = SCSI_2;
525 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
526 retry:
527 spin_lock_irqsave(shost->host_lock, flags);
528
529 found_target = __scsi_find_target(parent, channel, id);
530 if (found_target)
531 goto found;
532
533 list_add_tail(new: &starget->siblings, head: &shost->__targets);
534 spin_unlock_irqrestore(lock: shost->host_lock, flags);
535 /* allocate and add */
536 transport_setup_device(dev);
537 if (shost->hostt->target_alloc) {
538 error = shost->hostt->target_alloc(starget);
539
540 if(error) {
541 if (error != -ENXIO)
542 dev_err(dev, "target allocation failed, error %d\n", error);
543 /* don't want scsi_target_reap to do the final
544 * put because it will be under the host lock */
545 scsi_target_destroy(starget);
546 return NULL;
547 }
548 }
549 get_device(dev);
550
551 return starget;
552
553 found:
554 /*
555 * release routine already fired if kref is zero, so if we can still
556 * take the reference, the target must be alive. If we can't, it must
557 * be dying and we need to wait for a new target
558 */
559 ref_got = kref_get_unless_zero(kref: &found_target->reap_ref);
560
561 spin_unlock_irqrestore(lock: shost->host_lock, flags);
562 if (ref_got) {
563 put_device(dev);
564 return found_target;
565 }
566 /*
567 * Unfortunately, we found a dying target; need to wait until it's
568 * dead before we can get a new one. There is an anomaly here. We
569 * *should* call scsi_target_reap() to balance the kref_get() of the
570 * reap_ref above. However, since the target being released, it's
571 * already invisible and the reap_ref is irrelevant. If we call
572 * scsi_target_reap() we might spuriously do another device_del() on
573 * an already invisible target.
574 */
575 put_device(dev: &found_target->dev);
576 /*
577 * length of time is irrelevant here, we just want to yield the CPU
578 * for a tick to avoid busy waiting for the target to die.
579 */
580 msleep(msecs: 1);
581 goto retry;
582}
583
584/**
585 * scsi_target_reap - check to see if target is in use and destroy if not
586 * @starget: target to be checked
587 *
588 * This is used after removing a LUN or doing a last put of the target
589 * it checks atomically that nothing is using the target and removes
590 * it if so.
591 */
592void scsi_target_reap(struct scsi_target *starget)
593{
594 /*
595 * serious problem if this triggers: STARGET_DEL is only set in the if
596 * the reap_ref drops to zero, so we're trying to do another final put
597 * on an already released kref
598 */
599 BUG_ON(starget->state == STARGET_DEL);
600 scsi_target_reap_ref_put(starget);
601}
602
603/**
604 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
605 * INQUIRY result string
606 * @s: INQUIRY result string to sanitize
607 * @len: length of the string
608 *
609 * Description:
610 * The SCSI spec says that INQUIRY vendor, product, and revision
611 * strings must consist entirely of graphic ASCII characters,
612 * padded on the right with spaces. Since not all devices obey
613 * this rule, we will replace non-graphic or non-ASCII characters
614 * with spaces. Exception: a NUL character is interpreted as a
615 * string terminator, so all the following characters are set to
616 * spaces.
617 **/
618void scsi_sanitize_inquiry_string(unsigned char *s, int len)
619{
620 int terminated = 0;
621
622 for (; len > 0; (--len, ++s)) {
623 if (*s == 0)
624 terminated = 1;
625 if (terminated || *s < 0x20 || *s > 0x7e)
626 *s = ' ';
627 }
628}
629EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
630
631
632/**
633 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
634 * @sdev: scsi_device to probe
635 * @inq_result: area to store the INQUIRY result
636 * @result_len: len of inq_result
637 * @bflags: store any bflags found here
638 *
639 * Description:
640 * Probe the lun associated with @req using a standard SCSI INQUIRY;
641 *
642 * If the INQUIRY is successful, zero is returned and the
643 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
644 * are copied to the scsi_device any flags value is stored in *@bflags.
645 **/
646static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
647 int result_len, blist_flags_t *bflags)
648{
649 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
650 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
651 int response_len = 0;
652 int pass, count, result, resid;
653 struct scsi_failure failure_defs[] = {
654 /*
655 * not-ready to ready transition [asc/ascq=0x28/0x0] or
656 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY
657 * should not yield UNIT_ATTENTION but many buggy devices do
658 * so anyway.
659 */
660 {
661 .sense = UNIT_ATTENTION,
662 .asc = 0x28,
663 .result = SAM_STAT_CHECK_CONDITION,
664 },
665 {
666 .sense = UNIT_ATTENTION,
667 .asc = 0x29,
668 .result = SAM_STAT_CHECK_CONDITION,
669 },
670 {
671 .allowed = 1,
672 .result = DID_TIME_OUT << 16,
673 },
674 {}
675 };
676 struct scsi_failures failures = {
677 .total_allowed = 3,
678 .failure_definitions = failure_defs,
679 };
680 const struct scsi_exec_args exec_args = {
681 .resid = &resid,
682 .failures = &failures,
683 };
684
685 *bflags = 0;
686
687 /* Perform up to 3 passes. The first pass uses a conservative
688 * transfer length of 36 unless sdev->inquiry_len specifies a
689 * different value. */
690 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
691 try_inquiry_len = first_inquiry_len;
692 pass = 1;
693
694 next_pass:
695 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
696 "scsi scan: INQUIRY pass %d length %d\n",
697 pass, try_inquiry_len));
698
699 /* Each pass gets up to three chances to ignore Unit Attention */
700 scsi_failures_reset_retries(failures: &failures);
701
702 for (count = 0; count < 3; ++count) {
703 memset(s: scsi_cmd, c: 0, n: 6);
704 scsi_cmd[0] = INQUIRY;
705 scsi_cmd[4] = (unsigned char) try_inquiry_len;
706
707 memset(s: inq_result, c: 0, n: try_inquiry_len);
708
709 result = scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN,
710 buffer: inq_result, bufflen: try_inquiry_len,
711 HZ / 2 + HZ * scsi_inq_timeout, retries: 3,
712 args: &exec_args);
713
714 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
715 "scsi scan: INQUIRY %s with code 0x%x\n",
716 result ? "failed" : "successful", result));
717
718 if (result == 0) {
719 /*
720 * if nothing was transferred, we try
721 * again. It's a workaround for some USB
722 * devices.
723 */
724 if (resid == try_inquiry_len)
725 continue;
726 }
727 break;
728 }
729
730 if (result == 0) {
731 scsi_sanitize_inquiry_string(&inq_result[8], 8);
732 scsi_sanitize_inquiry_string(&inq_result[16], 16);
733 scsi_sanitize_inquiry_string(&inq_result[32], 4);
734
735 response_len = inq_result[4] + 5;
736 if (response_len > 255)
737 response_len = first_inquiry_len; /* sanity */
738
739 /*
740 * Get any flags for this device.
741 *
742 * XXX add a bflags to scsi_device, and replace the
743 * corresponding bit fields in scsi_device, so bflags
744 * need not be passed as an argument.
745 */
746 *bflags = scsi_get_device_flags(sdev, vendor: &inq_result[8],
747 model: &inq_result[16]);
748
749 /* When the first pass succeeds we gain information about
750 * what larger transfer lengths might work. */
751 if (pass == 1) {
752 if (BLIST_INQUIRY_36 & *bflags)
753 next_inquiry_len = 36;
754 /*
755 * LLD specified a maximum sdev->inquiry_len
756 * but device claims it has more data. Capping
757 * the length only makes sense for legacy
758 * devices. If a device supports SPC-4 (2014)
759 * or newer, assume that it is safe to ask for
760 * as much as the device says it supports.
761 */
762 else if (sdev->inquiry_len &&
763 response_len > sdev->inquiry_len &&
764 (inq_result[2] & 0x7) < 6) /* SPC-4 */
765 next_inquiry_len = sdev->inquiry_len;
766 else
767 next_inquiry_len = response_len;
768
769 /* If more data is available perform the second pass */
770 if (next_inquiry_len > try_inquiry_len) {
771 try_inquiry_len = next_inquiry_len;
772 pass = 2;
773 goto next_pass;
774 }
775 }
776
777 } else if (pass == 2) {
778 sdev_printk(KERN_INFO, sdev,
779 "scsi scan: %d byte inquiry failed. "
780 "Consider BLIST_INQUIRY_36 for this device\n",
781 try_inquiry_len);
782
783 /* If this pass failed, the third pass goes back and transfers
784 * the same amount as we successfully got in the first pass. */
785 try_inquiry_len = first_inquiry_len;
786 pass = 3;
787 goto next_pass;
788 }
789
790 /* If the last transfer attempt got an error, assume the
791 * peripheral doesn't exist or is dead. */
792 if (result)
793 return -EIO;
794
795 /* Don't report any more data than the device says is valid */
796 sdev->inquiry_len = min(try_inquiry_len, response_len);
797
798 /*
799 * XXX Abort if the response length is less than 36? If less than
800 * 32, the lookup of the device flags (above) could be invalid,
801 * and it would be possible to take an incorrect action - we do
802 * not want to hang because of a short INQUIRY. On the flip side,
803 * if the device is spun down or becoming ready (and so it gives a
804 * short INQUIRY), an abort here prevents any further use of the
805 * device, including spin up.
806 *
807 * On the whole, the best approach seems to be to assume the first
808 * 36 bytes are valid no matter what the device says. That's
809 * better than copying < 36 bytes to the inquiry-result buffer
810 * and displaying garbage for the Vendor, Product, or Revision
811 * strings.
812 */
813 if (sdev->inquiry_len < 36) {
814 if (!sdev->host->short_inquiry) {
815 shost_printk(KERN_INFO, sdev->host,
816 "scsi scan: INQUIRY result too short (%d),"
817 " using 36\n", sdev->inquiry_len);
818 sdev->host->short_inquiry = 1;
819 }
820 sdev->inquiry_len = 36;
821 }
822
823 /*
824 * Related to the above issue:
825 *
826 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
827 * and if not ready, sent a START_STOP to start (maybe spin up) and
828 * then send the INQUIRY again, since the INQUIRY can change after
829 * a device is initialized.
830 *
831 * Ideally, start a device if explicitly asked to do so. This
832 * assumes that a device is spun up on power on, spun down on
833 * request, and then spun up on request.
834 */
835
836 /*
837 * The scanning code needs to know the scsi_level, even if no
838 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
839 * non-zero LUNs can be scanned.
840 */
841 sdev->scsi_level = inq_result[2] & 0x0f;
842 if (sdev->scsi_level >= 2 ||
843 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
844 sdev->scsi_level++;
845 sdev->sdev_target->scsi_level = sdev->scsi_level;
846
847 /*
848 * If SCSI-2 or lower, and if the transport requires it,
849 * store the LUN value in CDB[1].
850 */
851 sdev->lun_in_cdb = 0;
852 if (sdev->scsi_level <= SCSI_2 &&
853 sdev->scsi_level != SCSI_UNKNOWN &&
854 !sdev->host->no_scsi2_lun_in_cdb)
855 sdev->lun_in_cdb = 1;
856
857 return 0;
858}
859
860/**
861 * scsi_add_lun - allocate and fully initialze a scsi_device
862 * @sdev: holds information to be stored in the new scsi_device
863 * @inq_result: holds the result of a previous INQUIRY to the LUN
864 * @bflags: black/white list flag
865 * @async: 1 if this device is being scanned asynchronously
866 *
867 * Description:
868 * Initialize the scsi_device @sdev. Optionally set fields based
869 * on values in *@bflags.
870 *
871 * Return:
872 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
873 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
874 **/
875static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
876 blist_flags_t *bflags, int async)
877{
878 const struct scsi_host_template *hostt = sdev->host->hostt;
879 struct queue_limits lim;
880 int ret;
881
882 /*
883 * XXX do not save the inquiry, since it can change underneath us,
884 * save just vendor/model/rev.
885 *
886 * Rather than save it and have an ioctl that retrieves the saved
887 * value, have an ioctl that executes the same INQUIRY code used
888 * in scsi_probe_lun, let user level programs doing INQUIRY
889 * scanning run at their own risk, or supply a user level program
890 * that can correctly scan.
891 */
892
893 /*
894 * Copy at least 36 bytes of INQUIRY data, so that we don't
895 * dereference unallocated memory when accessing the Vendor,
896 * Product, and Revision strings. Badly behaved devices may set
897 * the INQUIRY Additional Length byte to a small value, indicating
898 * these strings are invalid, but often they contain plausible data
899 * nonetheless. It doesn't matter if the device sent < 36 bytes
900 * total, since scsi_probe_lun() initializes inq_result with 0s.
901 */
902 sdev->inquiry = kmemdup(inq_result,
903 max_t(size_t, sdev->inquiry_len, 36),
904 GFP_KERNEL);
905 if (sdev->inquiry == NULL)
906 return SCSI_SCAN_NO_RESPONSE;
907
908 sdev->vendor = (char *) (sdev->inquiry + 8);
909 sdev->model = (char *) (sdev->inquiry + 16);
910 sdev->rev = (char *) (sdev->inquiry + 32);
911
912 sdev->is_ata = strncmp(sdev->vendor, "ATA ", 8) == 0;
913 if (sdev->is_ata) {
914 /*
915 * sata emulation layer device. This is a hack to work around
916 * the SATL power management specifications which state that
917 * when the SATL detects the device has gone into standby
918 * mode, it shall respond with NOT READY.
919 */
920 sdev->allow_restart = 1;
921 }
922
923 if (*bflags & BLIST_ISROM) {
924 sdev->type = TYPE_ROM;
925 sdev->removable = 1;
926 } else {
927 sdev->type = (inq_result[0] & 0x1f);
928 sdev->removable = (inq_result[1] & 0x80) >> 7;
929
930 /*
931 * some devices may respond with wrong type for
932 * well-known logical units. Force well-known type
933 * to enumerate them correctly.
934 */
935 if (scsi_is_wlun(lun: sdev->lun) && sdev->type != TYPE_WLUN) {
936 sdev_printk(KERN_WARNING, sdev,
937 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
938 __func__, sdev->type, (unsigned int)sdev->lun);
939 sdev->type = TYPE_WLUN;
940 }
941
942 }
943
944 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
945 /* RBC and MMC devices can return SCSI-3 compliance and yet
946 * still not support REPORT LUNS, so make them act as
947 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
948 * specifically set */
949 if ((*bflags & BLIST_REPORTLUN2) == 0)
950 *bflags |= BLIST_NOREPORTLUN;
951 }
952
953 /*
954 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
955 * spec says: The device server is capable of supporting the
956 * specified peripheral device type on this logical unit. However,
957 * the physical device is not currently connected to this logical
958 * unit.
959 *
960 * The above is vague, as it implies that we could treat 001 and
961 * 011 the same. Stay compatible with previous code, and create a
962 * scsi_device for a PQ of 1
963 *
964 * Don't set the device offline here; rather let the upper
965 * level drivers eval the PQ to decide whether they should
966 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
967 */
968
969 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
970 sdev->lockable = sdev->removable;
971 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
972
973 if (sdev->scsi_level >= SCSI_3 ||
974 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
975 sdev->ppr = 1;
976 if (inq_result[7] & 0x60)
977 sdev->wdtr = 1;
978 if (inq_result[7] & 0x10)
979 sdev->sdtr = 1;
980
981 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
982 "ANSI: %d%s\n", scsi_device_type(sdev->type),
983 sdev->vendor, sdev->model, sdev->rev,
984 sdev->inq_periph_qual, inq_result[2] & 0x07,
985 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
986
987 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
988 !(*bflags & BLIST_NOTQ)) {
989 sdev->tagged_supported = 1;
990 sdev->simple_tags = 1;
991 }
992
993 /*
994 * Some devices (Texel CD ROM drives) have handshaking problems
995 * when used with the Seagate controllers. borken is initialized
996 * to 1, and then set it to 0 here.
997 */
998 if ((*bflags & BLIST_BORKEN) == 0)
999 sdev->borken = 0;
1000
1001 if (*bflags & BLIST_NO_ULD_ATTACH)
1002 sdev->no_uld_attach = 1;
1003
1004 /*
1005 * Apparently some really broken devices (contrary to the SCSI
1006 * standards) need to be selected without asserting ATN
1007 */
1008 if (*bflags & BLIST_SELECT_NO_ATN)
1009 sdev->select_no_atn = 1;
1010
1011 /*
1012 * Some devices may not want to have a start command automatically
1013 * issued when a device is added.
1014 */
1015 if (*bflags & BLIST_NOSTARTONADD)
1016 sdev->no_start_on_add = 1;
1017
1018 if (*bflags & BLIST_SINGLELUN)
1019 scsi_target(sdev)->single_lun = 1;
1020
1021 sdev->use_10_for_rw = 1;
1022
1023 /* some devices don't like REPORT SUPPORTED OPERATION CODES
1024 * and will simply timeout causing sd_mod init to take a very
1025 * very long time */
1026 if (*bflags & BLIST_NO_RSOC)
1027 sdev->no_report_opcodes = 1;
1028
1029 /* set the device running here so that slave configure
1030 * may do I/O */
1031 mutex_lock(lock: &sdev->state_mutex);
1032 ret = scsi_device_set_state(sdev, state: SDEV_RUNNING);
1033 if (ret)
1034 ret = scsi_device_set_state(sdev, state: SDEV_BLOCK);
1035 mutex_unlock(lock: &sdev->state_mutex);
1036
1037 if (ret) {
1038 sdev_printk(KERN_ERR, sdev,
1039 "in wrong state %s to complete scan\n",
1040 scsi_device_state_name(sdev->sdev_state));
1041 return SCSI_SCAN_NO_RESPONSE;
1042 }
1043
1044 if (*bflags & BLIST_NOT_LOCKABLE)
1045 sdev->lockable = 0;
1046
1047 if (*bflags & BLIST_RETRY_HWERROR)
1048 sdev->retry_hwerror = 1;
1049
1050 if (*bflags & BLIST_NO_DIF)
1051 sdev->no_dif = 1;
1052
1053 if (*bflags & BLIST_UNMAP_LIMIT_WS)
1054 sdev->unmap_limit_for_ws = 1;
1055
1056 if (*bflags & BLIST_IGN_MEDIA_CHANGE)
1057 sdev->ignore_media_change = 1;
1058
1059 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
1060
1061 if (*bflags & BLIST_TRY_VPD_PAGES)
1062 sdev->try_vpd_pages = 1;
1063 else if (*bflags & BLIST_SKIP_VPD_PAGES)
1064 sdev->skip_vpd_pages = 1;
1065
1066 if (*bflags & BLIST_NO_VPD_SIZE)
1067 sdev->no_vpd_size = 1;
1068
1069 transport_configure_device(&sdev->sdev_gendev);
1070
1071 /*
1072 * No need to freeze the queue as it isn't reachable to anyone else yet.
1073 */
1074 lim = queue_limits_start_update(q: sdev->request_queue);
1075 if (*bflags & BLIST_MAX_512)
1076 lim.max_hw_sectors = 512;
1077 else if (*bflags & BLIST_MAX_1024)
1078 lim.max_hw_sectors = 1024;
1079
1080 if (hostt->sdev_configure)
1081 ret = hostt->sdev_configure(sdev, &lim);
1082 if (ret) {
1083 queue_limits_cancel_update(q: sdev->request_queue);
1084 /*
1085 * If the LLDD reports device not present, don't clutter the
1086 * console with failure messages.
1087 */
1088 if (ret != -ENXIO)
1089 sdev_printk(KERN_ERR, sdev,
1090 "failed to configure device\n");
1091 return SCSI_SCAN_NO_RESPONSE;
1092 }
1093
1094 ret = queue_limits_commit_update(q: sdev->request_queue, lim: &lim);
1095 if (ret) {
1096 sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n");
1097 return SCSI_SCAN_NO_RESPONSE;
1098 }
1099
1100 /*
1101 * The queue_depth is often changed in ->sdev_configure.
1102 *
1103 * Set up budget map again since memory consumption of the map depends
1104 * on actual queue depth.
1105 */
1106 if (hostt->sdev_configure)
1107 scsi_realloc_sdev_budget_map(sdev, depth: sdev->queue_depth);
1108
1109 if (sdev->scsi_level >= SCSI_3)
1110 scsi_attach_vpd(sdev);
1111
1112 scsi_cdl_check(sdev);
1113
1114 sdev->max_queue_depth = sdev->queue_depth;
1115 WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth);
1116 sdev->sdev_bflags = *bflags;
1117
1118 /*
1119 * Ok, the device is now all set up, we can
1120 * register it and tell the rest of the kernel
1121 * about it.
1122 */
1123 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
1124 return SCSI_SCAN_NO_RESPONSE;
1125
1126 return SCSI_SCAN_LUN_PRESENT;
1127}
1128
1129#ifdef CONFIG_SCSI_LOGGING
1130/**
1131 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
1132 * @buf: Output buffer with at least end-first+1 bytes of space
1133 * @inq: Inquiry buffer (input)
1134 * @first: Offset of string into inq
1135 * @end: Index after last character in inq
1136 */
1137static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1138 unsigned first, unsigned end)
1139{
1140 unsigned term = 0, idx;
1141
1142 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1143 if (inq[idx+first] > ' ') {
1144 buf[idx] = inq[idx+first];
1145 term = idx+1;
1146 } else {
1147 buf[idx] = ' ';
1148 }
1149 }
1150 buf[term] = 0;
1151 return buf;
1152}
1153#endif
1154
1155/**
1156 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1157 * @starget: pointer to target device structure
1158 * @lun: LUN of target device
1159 * @bflagsp: store bflags here if not NULL
1160 * @sdevp: probe the LUN corresponding to this scsi_device
1161 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1162 * needed on first scan
1163 * @hostdata: passed to scsi_alloc_sdev()
1164 *
1165 * Description:
1166 * Call scsi_probe_lun, if a LUN with an attached device is found,
1167 * allocate and set it up by calling scsi_add_lun.
1168 *
1169 * Return:
1170 *
1171 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1172 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1173 * attached at the LUN
1174 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1175 **/
1176static int scsi_probe_and_add_lun(struct scsi_target *starget,
1177 u64 lun, blist_flags_t *bflagsp,
1178 struct scsi_device **sdevp,
1179 enum scsi_scan_mode rescan,
1180 void *hostdata)
1181{
1182 struct scsi_device *sdev;
1183 unsigned char *result;
1184 blist_flags_t bflags;
1185 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1186 struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent);
1187
1188 /*
1189 * The rescan flag is used as an optimization, the first scan of a
1190 * host adapter calls into here with rescan == 0.
1191 */
1192 sdev = scsi_device_lookup_by_target(starget, lun);
1193 if (sdev) {
1194 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {
1195 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1196 "scsi scan: device exists on %s\n",
1197 dev_name(&sdev->sdev_gendev)));
1198 if (sdevp)
1199 *sdevp = sdev;
1200 else
1201 scsi_device_put(sdev);
1202
1203 if (bflagsp)
1204 *bflagsp = scsi_get_device_flags(sdev,
1205 vendor: sdev->vendor,
1206 model: sdev->model);
1207 return SCSI_SCAN_LUN_PRESENT;
1208 }
1209 scsi_device_put(sdev);
1210 } else
1211 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1212 if (!sdev)
1213 goto out;
1214
1215 result = kmalloc(result_len, GFP_KERNEL);
1216 if (!result)
1217 goto out_free_sdev;
1218
1219 if (scsi_probe_lun(sdev, inq_result: result, result_len, bflags: &bflags))
1220 goto out_free_result;
1221
1222 if (bflagsp)
1223 *bflagsp = bflags;
1224 /*
1225 * result contains valid SCSI INQUIRY data.
1226 */
1227 if ((result[0] >> 5) == 3) {
1228 /*
1229 * For a Peripheral qualifier 3 (011b), the SCSI
1230 * spec says: The device server is not capable of
1231 * supporting a physical device on this logical
1232 * unit.
1233 *
1234 * For disks, this implies that there is no
1235 * logical disk configured at sdev->lun, but there
1236 * is a target id responding.
1237 */
1238 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1239 " peripheral qualifier of 3, device not"
1240 " added\n"))
1241 if (lun == 0) {
1242 SCSI_LOG_SCAN_BUS(1, {
1243 unsigned char vend[9];
1244 unsigned char mod[17];
1245
1246 sdev_printk(KERN_INFO, sdev,
1247 "scsi scan: consider passing scsi_mod."
1248 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1249 scsi_inq_str(vend, result, 8, 16),
1250 scsi_inq_str(mod, result, 16, 32));
1251 });
1252
1253 }
1254
1255 res = SCSI_SCAN_TARGET_PRESENT;
1256 goto out_free_result;
1257 }
1258
1259 /*
1260 * Some targets may set slight variations of PQ and PDT to signal
1261 * that no LUN is present, so don't add sdev in these cases.
1262 * Two specific examples are:
1263 * 1) NetApp targets: return PQ=1, PDT=0x1f
1264 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1265 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1266 *
1267 * References:
1268 * 1) SCSI SPC-3, pp. 145-146
1269 * PQ=1: "A peripheral device having the specified peripheral
1270 * device type is not connected to this logical unit. However, the
1271 * device server is capable of supporting the specified peripheral
1272 * device type on this logical unit."
1273 * PDT=0x1f: "Unknown or no device type"
1274 * 2) USB UFI 1.0, p. 20
1275 * PDT=00h Direct-access device (floppy)
1276 * PDT=1Fh none (no FDD connected to the requested logical unit)
1277 */
1278 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1279 (result[0] & 0x1f) == 0x1f &&
1280 !scsi_is_wlun(lun)) {
1281 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1282 "scsi scan: peripheral device type"
1283 " of 31, no device added\n"));
1284 res = SCSI_SCAN_TARGET_PRESENT;
1285 goto out_free_result;
1286 }
1287
1288 res = scsi_add_lun(sdev, inq_result: result, bflags: &bflags, async: shost->async_scan);
1289 if (res == SCSI_SCAN_LUN_PRESENT) {
1290 if (bflags & BLIST_KEY) {
1291 sdev->lockable = 0;
1292 scsi_unlock_floptical(sdev, result);
1293 }
1294 }
1295
1296 out_free_result:
1297 kfree(objp: result);
1298 out_free_sdev:
1299 if (res == SCSI_SCAN_LUN_PRESENT) {
1300 if (sdevp) {
1301 if (scsi_device_get(sdev) == 0) {
1302 *sdevp = sdev;
1303 } else {
1304 __scsi_remove_device(sdev);
1305 res = SCSI_SCAN_NO_RESPONSE;
1306 }
1307 }
1308 } else
1309 __scsi_remove_device(sdev);
1310 out:
1311 return res;
1312}
1313
1314/**
1315 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1316 * @starget: pointer to target structure to scan
1317 * @bflags: black/white list flag for LUN 0
1318 * @scsi_level: Which version of the standard does this device adhere to
1319 * @rescan: passed to scsi_probe_add_lun()
1320 *
1321 * Description:
1322 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1323 * scanned) to some maximum lun until a LUN is found with no device
1324 * attached. Use the bflags to figure out any oddities.
1325 *
1326 * Modifies sdevscan->lun.
1327 **/
1328static void scsi_sequential_lun_scan(struct scsi_target *starget,
1329 blist_flags_t bflags, int scsi_level,
1330 enum scsi_scan_mode rescan)
1331{
1332 uint max_dev_lun;
1333 u64 sparse_lun, lun;
1334 struct Scsi_Host *shost = dev_to_shost(dev: starget->dev.parent);
1335
1336 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1337 "scsi scan: Sequential scan\n"));
1338
1339 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1340 /*
1341 * If this device is known to support sparse multiple units,
1342 * override the other settings, and scan all of them. Normally,
1343 * SCSI-3 devices should be scanned via the REPORT LUNS.
1344 */
1345 if (bflags & BLIST_SPARSELUN) {
1346 max_dev_lun = shost->max_lun;
1347 sparse_lun = 1;
1348 } else
1349 sparse_lun = 0;
1350
1351 /*
1352 * If less than SCSI_1_CCS, and no special lun scanning, stop
1353 * scanning; this matches 2.4 behaviour, but could just be a bug
1354 * (to continue scanning a SCSI_1_CCS device).
1355 *
1356 * This test is broken. We might not have any device on lun0 for
1357 * a sparselun device, and if that's the case then how would we
1358 * know the real scsi_level, eh? It might make sense to just not
1359 * scan any SCSI_1 device for non-0 luns, but that check would best
1360 * go into scsi_alloc_sdev() and just have it return null when asked
1361 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1362 *
1363 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1364 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1365 == 0))
1366 return;
1367 */
1368 /*
1369 * If this device is known to support multiple units, override
1370 * the other settings, and scan all of them.
1371 */
1372 if (bflags & BLIST_FORCELUN)
1373 max_dev_lun = shost->max_lun;
1374 /*
1375 * REGAL CDC-4X: avoid hang after LUN 4
1376 */
1377 if (bflags & BLIST_MAX5LUN)
1378 max_dev_lun = min(5U, max_dev_lun);
1379 /*
1380 * Do not scan SCSI-2 or lower device past LUN 7, unless
1381 * BLIST_LARGELUN.
1382 */
1383 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1384 max_dev_lun = min(8U, max_dev_lun);
1385 else
1386 max_dev_lun = min(256U, max_dev_lun);
1387
1388 /*
1389 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1390 * until we reach the max, or no LUN is found and we are not
1391 * sparse_lun.
1392 */
1393 for (lun = 1; lun < max_dev_lun; ++lun)
1394 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1395 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1396 !sparse_lun)
1397 return;
1398}
1399
1400/**
1401 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1402 * @starget: which target
1403 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1404 * @rescan: nonzero if we can skip code only needed on first scan
1405 *
1406 * Description:
1407 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1408 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1409 *
1410 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1411 * LUNs even if it's older than SCSI-3.
1412 * If BLIST_NOREPORTLUN is set, return 1 always.
1413 * If BLIST_NOLUN is set, return 0 always.
1414 * If starget->no_report_luns is set, return 1 always.
1415 *
1416 * Return:
1417 * 0: scan completed (or no memory, so further scanning is futile)
1418 * 1: could not scan with REPORT LUN
1419 **/
1420static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,
1421 enum scsi_scan_mode rescan)
1422{
1423 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1424 unsigned int length;
1425 u64 lun;
1426 unsigned int num_luns;
1427 int result;
1428 struct scsi_lun *lunp, *lun_data;
1429 struct scsi_device *sdev;
1430 struct Scsi_Host *shost = dev_to_shost(dev: &starget->dev);
1431 struct scsi_failure failure_defs[] = {
1432 {
1433 .sense = UNIT_ATTENTION,
1434 .asc = SCMD_FAILURE_ASC_ANY,
1435 .ascq = SCMD_FAILURE_ASCQ_ANY,
1436 .result = SAM_STAT_CHECK_CONDITION,
1437 },
1438 /* Fail all CCs except the UA above */
1439 {
1440 .sense = SCMD_FAILURE_SENSE_ANY,
1441 .result = SAM_STAT_CHECK_CONDITION,
1442 },
1443 /* Retry any other errors not listed above */
1444 {
1445 .result = SCMD_FAILURE_RESULT_ANY,
1446 },
1447 {}
1448 };
1449 struct scsi_failures failures = {
1450 .total_allowed = 3,
1451 .failure_definitions = failure_defs,
1452 };
1453 const struct scsi_exec_args exec_args = {
1454 .failures = &failures,
1455 };
1456 int ret = 0;
1457
1458 /*
1459 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1460 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1461 * support more than 8 LUNs.
1462 * Don't attempt if the target doesn't support REPORT LUNS.
1463 */
1464 if (bflags & BLIST_NOREPORTLUN)
1465 return 1;
1466 if (starget->scsi_level < SCSI_2 &&
1467 starget->scsi_level != SCSI_UNKNOWN)
1468 return 1;
1469 if (starget->scsi_level < SCSI_3 &&
1470 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1471 return 1;
1472 if (bflags & BLIST_NOLUN)
1473 return 0;
1474 if (starget->no_report_luns)
1475 return 1;
1476
1477 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1478 sdev = scsi_alloc_sdev(starget, lun: 0, NULL);
1479 if (!sdev)
1480 return 0;
1481 if (scsi_device_get(sdev)) {
1482 __scsi_remove_device(sdev);
1483 return 0;
1484 }
1485 }
1486
1487 /*
1488 * Allocate enough to hold the header (the same size as one scsi_lun)
1489 * plus the number of luns we are requesting. 511 was the default
1490 * value of the now removed max_report_luns parameter.
1491 */
1492 length = (511 + 1) * sizeof(struct scsi_lun);
1493retry:
1494 lun_data = kmalloc(length, GFP_KERNEL);
1495 if (!lun_data) {
1496 printk(ALLOC_FAILURE_MSG, __func__);
1497 goto out;
1498 }
1499
1500 scsi_cmd[0] = REPORT_LUNS;
1501
1502 /*
1503 * bytes 1 - 5: reserved, set to zero.
1504 */
1505 memset(s: &scsi_cmd[1], c: 0, n: 5);
1506
1507 /*
1508 * bytes 6 - 9: length of the command.
1509 */
1510 put_unaligned_be32(val: length, p: &scsi_cmd[6]);
1511
1512 scsi_cmd[10] = 0; /* reserved */
1513 scsi_cmd[11] = 0; /* control */
1514
1515 /*
1516 * We can get a UNIT ATTENTION, for example a power on/reset, so
1517 * retry a few times (like sd.c does for TEST UNIT READY).
1518 * Experience shows some combinations of adapter/devices get at
1519 * least two power on/resets.
1520 *
1521 * Illegal requests (for devices that do not support REPORT LUNS)
1522 * should come through as a check condition, and will not generate
1523 * a retry.
1524 */
1525 scsi_failures_reset_retries(failures: &failures);
1526
1527 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1528 "scsi scan: Sending REPORT LUNS\n"));
1529
1530 result = scsi_execute_cmd(sdev, cmd: scsi_cmd, opf: REQ_OP_DRV_IN, buffer: lun_data,
1531 bufflen: length, SCSI_REPORT_LUNS_TIMEOUT, retries: 3,
1532 args: &exec_args);
1533
1534 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1535 "scsi scan: REPORT LUNS %s result 0x%x\n",
1536 result ? "failed" : "successful", result));
1537 if (result) {
1538 /*
1539 * The device probably does not support a REPORT LUN command
1540 */
1541 ret = 1;
1542 goto out_err;
1543 }
1544
1545 /*
1546 * Get the length from the first four bytes of lun_data.
1547 */
1548 if (get_unaligned_be32(p: lun_data->scsi_lun) +
1549 sizeof(struct scsi_lun) > length) {
1550 length = get_unaligned_be32(p: lun_data->scsi_lun) +
1551 sizeof(struct scsi_lun);
1552 kfree(objp: lun_data);
1553 goto retry;
1554 }
1555 length = get_unaligned_be32(p: lun_data->scsi_lun);
1556
1557 num_luns = (length / sizeof(struct scsi_lun));
1558
1559 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1560 "scsi scan: REPORT LUN scan\n"));
1561
1562 /*
1563 * Scan the luns in lun_data. The entry at offset 0 is really
1564 * the header, so start at 1 and go up to and including num_luns.
1565 */
1566 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1567 lun = scsilun_to_int(lunp);
1568
1569 if (lun > sdev->host->max_lun) {
1570 sdev_printk(KERN_WARNING, sdev,
1571 "lun%llu has a LUN larger than"
1572 " allowed by the host adapter\n", lun);
1573 } else {
1574 int res;
1575
1576 res = scsi_probe_and_add_lun(starget,
1577 lun, NULL, NULL, rescan, NULL);
1578 if (res == SCSI_SCAN_NO_RESPONSE) {
1579 /*
1580 * Got some results, but now none, abort.
1581 */
1582 sdev_printk(KERN_ERR, sdev,
1583 "Unexpected response"
1584 " from lun %llu while scanning, scan"
1585 " aborted\n", (unsigned long long)lun);
1586 break;
1587 }
1588 }
1589 }
1590
1591 out_err:
1592 kfree(objp: lun_data);
1593 out:
1594 if (scsi_device_created(sdev))
1595 /*
1596 * the sdev we used didn't appear in the report luns scan
1597 */
1598 __scsi_remove_device(sdev);
1599 scsi_device_put(sdev);
1600 return ret;
1601}
1602
1603struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1604 uint id, u64 lun, void *hostdata)
1605{
1606 struct scsi_device *sdev = ERR_PTR(error: -ENODEV);
1607 struct device *parent = &shost->shost_gendev;
1608 struct scsi_target *starget;
1609
1610 if (strncmp(scsi_scan_type, "none", 4) == 0)
1611 return ERR_PTR(error: -ENODEV);
1612
1613 starget = scsi_alloc_target(parent, channel, id);
1614 if (!starget)
1615 return ERR_PTR(error: -ENOMEM);
1616 scsi_autopm_get_target(starget);
1617
1618 mutex_lock(lock: &shost->scan_mutex);
1619 if (!shost->async_scan)
1620 scsi_complete_async_scans();
1621
1622 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1623 scsi_probe_and_add_lun(starget, lun, NULL, sdevp: &sdev,
1624 rescan: SCSI_SCAN_RESCAN, hostdata);
1625 scsi_autopm_put_host(shost);
1626 }
1627 mutex_unlock(lock: &shost->scan_mutex);
1628 scsi_autopm_put_target(starget);
1629 /*
1630 * paired with scsi_alloc_target(). Target will be destroyed unless
1631 * scsi_probe_and_add_lun made an underlying device visible
1632 */
1633 scsi_target_reap(starget);
1634 put_device(dev: &starget->dev);
1635
1636 return sdev;
1637}
1638EXPORT_SYMBOL(__scsi_add_device);
1639
1640/**
1641 * scsi_add_device - creates a new SCSI (LU) instance
1642 * @host: the &Scsi_Host instance where the device is located
1643 * @channel: target channel number (rarely other than %0)
1644 * @target: target id number
1645 * @lun: LUN of target device
1646 *
1647 * Probe for a specific LUN and add it if found.
1648 *
1649 * Notes: This call is usually performed internally during a SCSI
1650 * bus scan when an HBA is added (i.e. scsi_scan_host()). So it
1651 * should only be called if the HBA becomes aware of a new SCSI
1652 * device (LU) after scsi_scan_host() has completed. If successful
1653 * this call can lead to sdev_init() and sdev_configure() callbacks
1654 * into the LLD.
1655 *
1656 * Return: %0 on success or negative error code on failure
1657 */
1658int scsi_add_device(struct Scsi_Host *host, uint channel,
1659 uint target, u64 lun)
1660{
1661 struct scsi_device *sdev =
1662 __scsi_add_device(host, channel, target, lun, NULL);
1663 if (IS_ERR(ptr: sdev))
1664 return PTR_ERR(ptr: sdev);
1665
1666 scsi_device_put(sdev);
1667 return 0;
1668}
1669EXPORT_SYMBOL(scsi_add_device);
1670
1671int scsi_resume_device(struct scsi_device *sdev)
1672{
1673 struct device *dev = &sdev->sdev_gendev;
1674 int ret = 0;
1675
1676 device_lock(dev);
1677
1678 /*
1679 * Bail out if the device or its queue are not running. Otherwise,
1680 * the rescan may block waiting for commands to be executed, with us
1681 * holding the device lock. This can result in a potential deadlock
1682 * in the power management core code when system resume is on-going.
1683 */
1684 if (sdev->sdev_state != SDEV_RUNNING ||
1685 blk_queue_pm_only(sdev->request_queue)) {
1686 ret = -EWOULDBLOCK;
1687 goto unlock;
1688 }
1689
1690 if (dev->driver && try_module_get(module: dev->driver->owner)) {
1691 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1692
1693 if (drv->resume)
1694 ret = drv->resume(dev);
1695 module_put(module: dev->driver->owner);
1696 }
1697
1698unlock:
1699 device_unlock(dev);
1700
1701 return ret;
1702}
1703EXPORT_SYMBOL(scsi_resume_device);
1704
1705int scsi_rescan_device(struct scsi_device *sdev)
1706{
1707 struct device *dev = &sdev->sdev_gendev;
1708 int ret = 0;
1709
1710 device_lock(dev);
1711
1712 /*
1713 * Bail out if the device or its queue are not running. Otherwise,
1714 * the rescan may block waiting for commands to be executed, with us
1715 * holding the device lock. This can result in a potential deadlock
1716 * in the power management core code when system resume is on-going.
1717 */
1718 if (sdev->sdev_state != SDEV_RUNNING ||
1719 blk_queue_pm_only(sdev->request_queue)) {
1720 ret = -EWOULDBLOCK;
1721 goto unlock;
1722 }
1723
1724 scsi_attach_vpd(sdev);
1725 scsi_cdl_check(sdev);
1726
1727 if (sdev->handler && sdev->handler->rescan)
1728 sdev->handler->rescan(sdev);
1729
1730 if (dev->driver && try_module_get(module: dev->driver->owner)) {
1731 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1732
1733 if (drv->rescan)
1734 drv->rescan(dev);
1735 module_put(module: dev->driver->owner);
1736 }
1737
1738unlock:
1739 device_unlock(dev);
1740
1741 return ret;
1742}
1743EXPORT_SYMBOL(scsi_rescan_device);
1744
1745static void __scsi_scan_target(struct device *parent, unsigned int channel,
1746 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1747{
1748 struct Scsi_Host *shost = dev_to_shost(dev: parent);
1749 blist_flags_t bflags = 0;
1750 int res;
1751 struct scsi_target *starget;
1752
1753 if (shost->this_id == id)
1754 /*
1755 * Don't scan the host adapter
1756 */
1757 return;
1758
1759 starget = scsi_alloc_target(parent, channel, id);
1760 if (!starget)
1761 return;
1762 scsi_autopm_get_target(starget);
1763
1764 if (lun != SCAN_WILD_CARD) {
1765 /*
1766 * Scan for a specific host/chan/id/lun.
1767 */
1768 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1769 goto out_reap;
1770 }
1771
1772 /*
1773 * Scan LUN 0, if there is some response, scan further. Ideally, we
1774 * would not configure LUN 0 until all LUNs are scanned.
1775 */
1776 res = scsi_probe_and_add_lun(starget, lun: 0, bflagsp: &bflags, NULL, rescan, NULL);
1777 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1778 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1779 /*
1780 * The REPORT LUN did not scan the target,
1781 * do a sequential scan.
1782 */
1783 scsi_sequential_lun_scan(starget, bflags,
1784 scsi_level: starget->scsi_level, rescan);
1785 }
1786
1787 out_reap:
1788 scsi_autopm_put_target(starget);
1789 /*
1790 * paired with scsi_alloc_target(): determine if the target has
1791 * any children at all and if not, nuke it
1792 */
1793 scsi_target_reap(starget);
1794
1795 put_device(dev: &starget->dev);
1796}
1797
1798/**
1799 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1800 * @parent: host to scan
1801 * @channel: channel to scan
1802 * @id: target id to scan
1803 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1804 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1805 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1806 * and SCSI_SCAN_MANUAL to force scanning even if
1807 * 'scan=manual' is set.
1808 *
1809 * Description:
1810 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1811 * and possibly all LUNs on the target id.
1812 *
1813 * First try a REPORT LUN scan, if that does not scan the target, do a
1814 * sequential scan of LUNs on the target id.
1815 **/
1816void scsi_scan_target(struct device *parent, unsigned int channel,
1817 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1818{
1819 struct Scsi_Host *shost = dev_to_shost(dev: parent);
1820
1821 if (strncmp(scsi_scan_type, "none", 4) == 0)
1822 return;
1823
1824 if (rescan != SCSI_SCAN_MANUAL &&
1825 strncmp(scsi_scan_type, "manual", 6) == 0)
1826 return;
1827
1828 mutex_lock(lock: &shost->scan_mutex);
1829 if (!shost->async_scan)
1830 scsi_complete_async_scans();
1831
1832 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1833 __scsi_scan_target(parent, channel, id, lun, rescan);
1834 scsi_autopm_put_host(shost);
1835 }
1836 mutex_unlock(lock: &shost->scan_mutex);
1837}
1838EXPORT_SYMBOL(scsi_scan_target);
1839
1840static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1841 unsigned int id, u64 lun,
1842 enum scsi_scan_mode rescan)
1843{
1844 uint order_id;
1845
1846 if (id == SCAN_WILD_CARD)
1847 for (id = 0; id < shost->max_id; ++id) {
1848 /*
1849 * XXX adapter drivers when possible (FCP, iSCSI)
1850 * could modify max_id to match the current max,
1851 * not the absolute max.
1852 *
1853 * XXX add a shost id iterator, so for example,
1854 * the FC ID can be the same as a target id
1855 * without a huge overhead of sparse id's.
1856 */
1857 if (shost->reverse_ordering)
1858 /*
1859 * Scan from high to low id.
1860 */
1861 order_id = shost->max_id - id - 1;
1862 else
1863 order_id = id;
1864 __scsi_scan_target(parent: &shost->shost_gendev, channel,
1865 id: order_id, lun, rescan);
1866 }
1867 else
1868 __scsi_scan_target(parent: &shost->shost_gendev, channel,
1869 id, lun, rescan);
1870}
1871
1872int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1873 unsigned int id, u64 lun,
1874 enum scsi_scan_mode rescan)
1875{
1876 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1877 "%s: <%u:%u:%llu>\n",
1878 __func__, channel, id, lun));
1879
1880 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1881 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1882 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
1883 return -EINVAL;
1884
1885 mutex_lock(lock: &shost->scan_mutex);
1886 if (!shost->async_scan)
1887 scsi_complete_async_scans();
1888
1889 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1890 if (channel == SCAN_WILD_CARD)
1891 for (channel = 0; channel <= shost->max_channel;
1892 channel++)
1893 scsi_scan_channel(shost, channel, id, lun,
1894 rescan);
1895 else
1896 scsi_scan_channel(shost, channel, id, lun, rescan);
1897 scsi_autopm_put_host(shost);
1898 }
1899 mutex_unlock(lock: &shost->scan_mutex);
1900
1901 return 0;
1902}
1903EXPORT_SYMBOL(scsi_scan_host_selected);
1904static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1905{
1906 struct scsi_device *sdev;
1907 shost_for_each_device(sdev, shost) {
1908 /* target removed before the device could be added */
1909 if (sdev->sdev_state == SDEV_DEL)
1910 continue;
1911 /* If device is already visible, skip adding it to sysfs */
1912 if (sdev->is_visible)
1913 continue;
1914 if (!scsi_host_scan_allowed(shost) ||
1915 scsi_sysfs_add_sdev(sdev) != 0)
1916 __scsi_remove_device(sdev);
1917 }
1918}
1919
1920/**
1921 * scsi_prep_async_scan - prepare for an async scan
1922 * @shost: the host which will be scanned
1923 * Returns: a cookie to be passed to scsi_finish_async_scan()
1924 *
1925 * Tells the midlayer this host is going to do an asynchronous scan.
1926 * It reserves the host's position in the scanning list and ensures
1927 * that other asynchronous scans started after this one won't affect the
1928 * ordering of the discovered devices.
1929 */
1930static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1931{
1932 struct async_scan_data *data = NULL;
1933 unsigned long flags;
1934
1935 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1936 return NULL;
1937
1938 mutex_lock(lock: &shost->scan_mutex);
1939 if (shost->async_scan) {
1940 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
1941 goto err;
1942 }
1943
1944 data = kmalloc(sizeof(*data), GFP_KERNEL);
1945 if (!data)
1946 goto err;
1947 data->shost = scsi_host_get(shost);
1948 if (!data->shost)
1949 goto err;
1950 init_completion(x: &data->prev_finished);
1951
1952 spin_lock_irqsave(shost->host_lock, flags);
1953 shost->async_scan = 1;
1954 spin_unlock_irqrestore(lock: shost->host_lock, flags);
1955 mutex_unlock(lock: &shost->scan_mutex);
1956
1957 spin_lock(lock: &async_scan_lock);
1958 if (list_empty(head: &scanning_hosts))
1959 complete(&data->prev_finished);
1960 list_add_tail(new: &data->list, head: &scanning_hosts);
1961 spin_unlock(lock: &async_scan_lock);
1962
1963 return data;
1964
1965 err:
1966 mutex_unlock(lock: &shost->scan_mutex);
1967 kfree(objp: data);
1968 return NULL;
1969}
1970
1971/**
1972 * scsi_finish_async_scan - asynchronous scan has finished
1973 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1974 *
1975 * All the devices currently attached to this host have been found.
1976 * This function announces all the devices it has found to the rest
1977 * of the system.
1978 */
1979static void scsi_finish_async_scan(struct async_scan_data *data)
1980{
1981 struct Scsi_Host *shost;
1982 unsigned long flags;
1983
1984 if (!data)
1985 return;
1986
1987 shost = data->shost;
1988
1989 mutex_lock(lock: &shost->scan_mutex);
1990
1991 if (!shost->async_scan) {
1992 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1993 dump_stack();
1994 mutex_unlock(lock: &shost->scan_mutex);
1995 return;
1996 }
1997
1998 wait_for_completion(&data->prev_finished);
1999
2000 scsi_sysfs_add_devices(shost);
2001
2002 spin_lock_irqsave(shost->host_lock, flags);
2003 shost->async_scan = 0;
2004 spin_unlock_irqrestore(lock: shost->host_lock, flags);
2005
2006 mutex_unlock(lock: &shost->scan_mutex);
2007
2008 spin_lock(lock: &async_scan_lock);
2009 list_del(entry: &data->list);
2010 if (!list_empty(head: &scanning_hosts)) {
2011 struct async_scan_data *next = list_entry(scanning_hosts.next,
2012 struct async_scan_data, list);
2013 complete(&next->prev_finished);
2014 }
2015 spin_unlock(lock: &async_scan_lock);
2016
2017 scsi_autopm_put_host(shost);
2018 scsi_host_put(t: shost);
2019 kfree(objp: data);
2020}
2021
2022static void do_scsi_scan_host(struct Scsi_Host *shost)
2023{
2024 if (shost->hostt->scan_finished) {
2025 unsigned long start = jiffies;
2026 if (shost->hostt->scan_start)
2027 shost->hostt->scan_start(shost);
2028
2029 while (!shost->hostt->scan_finished(shost, jiffies - start))
2030 msleep(msecs: 10);
2031 } else {
2032 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
2033 SCAN_WILD_CARD, SCSI_SCAN_INITIAL);
2034 }
2035}
2036
2037static void do_scan_async(void *_data, async_cookie_t c)
2038{
2039 struct async_scan_data *data = _data;
2040 struct Scsi_Host *shost = data->shost;
2041
2042 do_scsi_scan_host(shost);
2043 scsi_finish_async_scan(data);
2044}
2045
2046/**
2047 * scsi_scan_host - scan the given adapter
2048 * @shost: adapter to scan
2049 *
2050 * Notes: Should be called after scsi_add_host()
2051 **/
2052void scsi_scan_host(struct Scsi_Host *shost)
2053{
2054 struct async_scan_data *data;
2055
2056 if (strncmp(scsi_scan_type, "none", 4) == 0 ||
2057 strncmp(scsi_scan_type, "manual", 6) == 0)
2058 return;
2059 if (scsi_autopm_get_host(shost) < 0)
2060 return;
2061
2062 data = scsi_prep_async_scan(shost);
2063 if (!data) {
2064 do_scsi_scan_host(shost);
2065 scsi_autopm_put_host(shost);
2066 return;
2067 }
2068
2069 /* register with the async subsystem so wait_for_device_probe()
2070 * will flush this work
2071 */
2072 async_schedule(func: do_scan_async, data);
2073
2074 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
2075}
2076EXPORT_SYMBOL(scsi_scan_host);
2077
2078void scsi_forget_host(struct Scsi_Host *shost)
2079{
2080 struct scsi_device *sdev;
2081 unsigned long flags;
2082
2083 restart:
2084 spin_lock_irqsave(shost->host_lock, flags);
2085 list_for_each_entry(sdev, &shost->__devices, siblings) {
2086 if (sdev->sdev_state == SDEV_DEL)
2087 continue;
2088 spin_unlock_irqrestore(lock: shost->host_lock, flags);
2089 __scsi_remove_device(sdev);
2090 goto restart;
2091 }
2092 spin_unlock_irqrestore(lock: shost->host_lock, flags);
2093}
2094
2095