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 <asm/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
84 static const char *scsi_null_device_strs = "nullnullnullnull";
85
86 #define MAX_SCSI_LUNS 512
87
88 static u64 max_scsi_luns = MAX_SCSI_LUNS;
89
90 module_param_named(max_luns, max_scsi_luns, ullong, S_IRUGO|S_IWUSR);
91 MODULE_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
100 char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT;
101
102 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type),
103 S_IRUGO|S_IWUSR);
104 MODULE_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
108 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
109
110 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
111 MODULE_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 */
116 static DEFINE_SPINLOCK(async_scan_lock);
117 static LIST_HEAD(scanning_hosts);
118
119 struct async_scan_data {
120 struct list_head list;
121 struct Scsi_Host *shost;
122 struct completion prev_finished;
123 };
124
125 /**
126 * scsi_complete_async_scans - Wait for asynchronous scans to complete
127 *
128 * When this function returns, any host which started scanning before
129 * this function was called will have finished its scan. Hosts which
130 * started scanning after this function was called may or may not have
131 * finished.
132 */
133 int scsi_complete_async_scans(void)
134 {
135 struct async_scan_data *data;
136
137 do {
138 if (list_empty(&scanning_hosts))
139 return 0;
140 /* If we can't get memory immediately, that's OK. Just
141 * sleep a little. Even if we never get memory, the async
142 * scans will finish eventually.
143 */
144 data = kmalloc(sizeof(*data), GFP_KERNEL);
145 if (!data)
146 msleep(1);
147 } while (!data);
148
149 data->shost = NULL;
150 init_completion(&data->prev_finished);
151
152 spin_lock(&async_scan_lock);
153 /* Check that there's still somebody else on the list */
154 if (list_empty(&scanning_hosts))
155 goto done;
156 list_add_tail(&data->list, &scanning_hosts);
157 spin_unlock(&async_scan_lock);
158
159 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
160 wait_for_completion(&data->prev_finished);
161
162 spin_lock(&async_scan_lock);
163 list_del(&data->list);
164 if (!list_empty(&scanning_hosts)) {
165 struct async_scan_data *next = list_entry(scanning_hosts.next,
166 struct async_scan_data, list);
167 complete(&next->prev_finished);
168 }
169 done:
170 spin_unlock(&async_scan_lock);
171
172 kfree(data);
173 return 0;
174 }
175
176 /**
177 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
178 * @sdev: scsi device to send command to
179 * @result: area to store the result of the MODE SENSE
180 *
181 * Description:
182 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
183 * Called for BLIST_KEY devices.
184 **/
185 static void scsi_unlock_floptical(struct scsi_device *sdev,
186 unsigned char *result)
187 {
188 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
189
190 sdev_printk(KERN_NOTICE, sdev, "unlocking floptical drive\n");
191 scsi_cmd[0] = MODE_SENSE;
192 scsi_cmd[1] = 0;
193 scsi_cmd[2] = 0x2e;
194 scsi_cmd[3] = 0;
195 scsi_cmd[4] = 0x2a; /* size */
196 scsi_cmd[5] = 0;
197 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
198 SCSI_TIMEOUT, 3, NULL);
199 }
200
201 /**
202 * scsi_alloc_sdev - allocate and setup a scsi_Device
203 * @starget: which target to allocate a &scsi_device for
204 * @lun: which lun
205 * @hostdata: usually NULL and set by ->slave_alloc instead
206 *
207 * Description:
208 * Allocate, initialize for io, and return a pointer to a scsi_Device.
209 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
210 * adds scsi_Device to the appropriate list.
211 *
212 * Return value:
213 * scsi_Device pointer, or NULL on failure.
214 **/
215 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
216 u64 lun, void *hostdata)
217 {
218 struct scsi_device *sdev;
219 int display_failure_msg = 1, ret;
220 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
221
222 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
223 GFP_KERNEL);
224 if (!sdev)
225 goto out;
226
227 sdev->vendor = scsi_null_device_strs;
228 sdev->model = scsi_null_device_strs;
229 sdev->rev = scsi_null_device_strs;
230 sdev->host = shost;
231 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
232 sdev->id = starget->id;
233 sdev->lun = lun;
234 sdev->channel = starget->channel;
235 mutex_init(&sdev->state_mutex);
236 sdev->sdev_state = SDEV_CREATED;
237 INIT_LIST_HEAD(&sdev->siblings);
238 INIT_LIST_HEAD(&sdev->same_target_siblings);
239 INIT_LIST_HEAD(&sdev->cmd_list);
240 INIT_LIST_HEAD(&sdev->starved_entry);
241 INIT_LIST_HEAD(&sdev->event_list);
242 spin_lock_init(&sdev->list_lock);
243 mutex_init(&sdev->inquiry_mutex);
244 INIT_WORK(&sdev->event_work, scsi_evt_thread);
245 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
246
247 sdev->sdev_gendev.parent = get_device(&starget->dev);
248 sdev->sdev_target = starget;
249
250 /* usually NULL and set by ->slave_alloc instead */
251 sdev->hostdata = hostdata;
252
253 /* if the device needs this changing, it may do so in the
254 * slave_configure function */
255 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
256
257 /*
258 * Some low level driver could use device->type
259 */
260 sdev->type = -1;
261
262 /*
263 * Assume that the device will have handshaking problems,
264 * and then fix this field later if it turns out it
265 * doesn't
266 */
267 sdev->borken = 1;
268
269 sdev->request_queue = scsi_mq_alloc_queue(sdev);
270 if (!sdev->request_queue) {
271 /* release fn is set up in scsi_sysfs_device_initialise, so
272 * have to free and put manually here */
273 put_device(&starget->dev);
274 kfree(sdev);
275 goto out;
276 }
277 WARN_ON_ONCE(!blk_get_queue(sdev->request_queue));
278 sdev->request_queue->queuedata = sdev;
279
280 scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ?
281 sdev->host->cmd_per_lun : 1);
282
283 scsi_sysfs_device_initialize(sdev);
284
285 if (shost->hostt->slave_alloc) {
286 ret = shost->hostt->slave_alloc(sdev);
287 if (ret) {
288 /*
289 * if LLDD reports slave not present, don't clutter
290 * console with alloc failure messages
291 */
292 if (ret == -ENXIO)
293 display_failure_msg = 0;
294 goto out_device_destroy;
295 }
296 }
297
298 return sdev;
299
300 out_device_destroy:
301 __scsi_remove_device(sdev);
302 out:
303 if (display_failure_msg)
304 printk(ALLOC_FAILURE_MSG, __func__);
305 return NULL;
306 }
307
308 static void scsi_target_destroy(struct scsi_target *starget)
309 {
310 struct device *dev = &starget->dev;
311 struct Scsi_Host *shost = dev_to_shost(dev->parent);
312 unsigned long flags;
313
314 BUG_ON(starget->state == STARGET_DEL);
315 starget->state = STARGET_DEL;
316 transport_destroy_device(dev);
317 spin_lock_irqsave(shost->host_lock, flags);
318 if (shost->hostt->target_destroy)
319 shost->hostt->target_destroy(starget);
320 list_del_init(&starget->siblings);
321 spin_unlock_irqrestore(shost->host_lock, flags);
322 put_device(dev);
323 }
324
325 static void scsi_target_dev_release(struct device *dev)
326 {
327 struct device *parent = dev->parent;
328 struct scsi_target *starget = to_scsi_target(dev);
329
330 kfree(starget);
331 put_device(parent);
332 }
333
334 static struct device_type scsi_target_type = {
335 .name = "scsi_target",
336 .release = scsi_target_dev_release,
337 };
338
339 int scsi_is_target_device(const struct device *dev)
340 {
341 return dev->type == &scsi_target_type;
342 }
343 EXPORT_SYMBOL(scsi_is_target_device);
344
345 static struct scsi_target *__scsi_find_target(struct device *parent,
346 int channel, uint id)
347 {
348 struct scsi_target *starget, *found_starget = NULL;
349 struct Scsi_Host *shost = dev_to_shost(parent);
350 /*
351 * Search for an existing target for this sdev.
352 */
353 list_for_each_entry(starget, &shost->__targets, siblings) {
354 if (starget->id == id &&
355 starget->channel == channel) {
356 found_starget = starget;
357 break;
358 }
359 }
360 if (found_starget)
361 get_device(&found_starget->dev);
362
363 return found_starget;
364 }
365
366 /**
367 * scsi_target_reap_ref_release - remove target from visibility
368 * @kref: the reap_ref in the target being released
369 *
370 * Called on last put of reap_ref, which is the indication that no device
371 * under this target is visible anymore, so render the target invisible in
372 * sysfs. Note: we have to be in user context here because the target reaps
373 * should be done in places where the scsi device visibility is being removed.
374 */
375 static void scsi_target_reap_ref_release(struct kref *kref)
376 {
377 struct scsi_target *starget
378 = container_of(kref, struct scsi_target, reap_ref);
379
380 /*
381 * if we get here and the target is still in a CREATED state that
382 * means it was allocated but never made visible (because a scan
383 * turned up no LUNs), so don't call device_del() on it.
384 */
385 if ((starget->state != STARGET_CREATED) &&
386 (starget->state != STARGET_CREATED_REMOVE)) {
387 transport_remove_device(&starget->dev);
388 device_del(&starget->dev);
389 }
390 scsi_target_destroy(starget);
391 }
392
393 static void scsi_target_reap_ref_put(struct scsi_target *starget)
394 {
395 kref_put(&starget->reap_ref, scsi_target_reap_ref_release);
396 }
397
398 /**
399 * scsi_alloc_target - allocate a new or find an existing target
400 * @parent: parent of the target (need not be a scsi host)
401 * @channel: target channel number (zero if no channels)
402 * @id: target id number
403 *
404 * Return an existing target if one exists, provided it hasn't already
405 * gone into STARGET_DEL state, otherwise allocate a new target.
406 *
407 * The target is returned with an incremented reference, so the caller
408 * is responsible for both reaping and doing a last put
409 */
410 static struct scsi_target *scsi_alloc_target(struct device *parent,
411 int channel, uint id)
412 {
413 struct Scsi_Host *shost = dev_to_shost(parent);
414 struct device *dev = NULL;
415 unsigned long flags;
416 const int size = sizeof(struct scsi_target)
417 + shost->transportt->target_size;
418 struct scsi_target *starget;
419 struct scsi_target *found_target;
420 int error, ref_got;
421
422 starget = kzalloc(size, GFP_KERNEL);
423 if (!starget) {
424 printk(KERN_ERR "%s: allocation failure\n", __func__);
425 return NULL;
426 }
427 dev = &starget->dev;
428 device_initialize(dev);
429 kref_init(&starget->reap_ref);
430 dev->parent = get_device(parent);
431 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
432 dev->bus = &scsi_bus_type;
433 dev->type = &scsi_target_type;
434 starget->id = id;
435 starget->channel = channel;
436 starget->can_queue = 0;
437 INIT_LIST_HEAD(&starget->siblings);
438 INIT_LIST_HEAD(&starget->devices);
439 starget->state = STARGET_CREATED;
440 starget->scsi_level = SCSI_2;
441 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
442 retry:
443 spin_lock_irqsave(shost->host_lock, flags);
444
445 found_target = __scsi_find_target(parent, channel, id);
446 if (found_target)
447 goto found;
448
449 list_add_tail(&starget->siblings, &shost->__targets);
450 spin_unlock_irqrestore(shost->host_lock, flags);
451 /* allocate and add */
452 transport_setup_device(dev);
453 if (shost->hostt->target_alloc) {
454 error = shost->hostt->target_alloc(starget);
455
456 if(error) {
457 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
458 /* don't want scsi_target_reap to do the final
459 * put because it will be under the host lock */
460 scsi_target_destroy(starget);
461 return NULL;
462 }
463 }
464 get_device(dev);
465
466 return starget;
467
468 found:
469 /*
470 * release routine already fired if kref is zero, so if we can still
471 * take the reference, the target must be alive. If we can't, it must
472 * be dying and we need to wait for a new target
473 */
474 ref_got = kref_get_unless_zero(&found_target->reap_ref);
475
476 spin_unlock_irqrestore(shost->host_lock, flags);
477 if (ref_got) {
478 put_device(dev);
479 return found_target;
480 }
481 /*
482 * Unfortunately, we found a dying target; need to wait until it's
483 * dead before we can get a new one. There is an anomaly here. We
484 * *should* call scsi_target_reap() to balance the kref_get() of the
485 * reap_ref above. However, since the target being released, it's
486 * already invisible and the reap_ref is irrelevant. If we call
487 * scsi_target_reap() we might spuriously do another device_del() on
488 * an already invisible target.
489 */
490 put_device(&found_target->dev);
491 /*
492 * length of time is irrelevant here, we just want to yield the CPU
493 * for a tick to avoid busy waiting for the target to die.
494 */
495 msleep(1);
496 goto retry;
497 }
498
499 /**
500 * scsi_target_reap - check to see if target is in use and destroy if not
501 * @starget: target to be checked
502 *
503 * This is used after removing a LUN or doing a last put of the target
504 * it checks atomically that nothing is using the target and removes
505 * it if so.
506 */
507 void scsi_target_reap(struct scsi_target *starget)
508 {
509 /*
510 * serious problem if this triggers: STARGET_DEL is only set in the if
511 * the reap_ref drops to zero, so we're trying to do another final put
512 * on an already released kref
513 */
514 BUG_ON(starget->state == STARGET_DEL);
515 scsi_target_reap_ref_put(starget);
516 }
517
518 /**
519 * scsi_sanitize_inquiry_string - remove non-graphical chars from an
520 * INQUIRY result string
521 * @s: INQUIRY result string to sanitize
522 * @len: length of the string
523 *
524 * Description:
525 * The SCSI spec says that INQUIRY vendor, product, and revision
526 * strings must consist entirely of graphic ASCII characters,
527 * padded on the right with spaces. Since not all devices obey
528 * this rule, we will replace non-graphic or non-ASCII characters
529 * with spaces. Exception: a NUL character is interpreted as a
530 * string terminator, so all the following characters are set to
531 * spaces.
532 **/
533 void scsi_sanitize_inquiry_string(unsigned char *s, int len)
534 {
535 int terminated = 0;
536
537 for (; len > 0; (--len, ++s)) {
538 if (*s == 0)
539 terminated = 1;
540 if (terminated || *s < 0x20 || *s > 0x7e)
541 *s = ' ';
542 }
543 }
544 EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
545
546 /**
547 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
548 * @sdev: scsi_device to probe
549 * @inq_result: area to store the INQUIRY result
550 * @result_len: len of inq_result
551 * @bflags: store any bflags found here
552 *
553 * Description:
554 * Probe the lun associated with @req using a standard SCSI INQUIRY;
555 *
556 * If the INQUIRY is successful, zero is returned and the
557 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
558 * are copied to the scsi_device any flags value is stored in *@bflags.
559 **/
560 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
561 int result_len, blist_flags_t *bflags)
562 {
563 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
564 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
565 int response_len = 0;
566 int pass, count, result;
567 struct scsi_sense_hdr sshdr;
568
569 *bflags = 0;
570
571 /* Perform up to 3 passes. The first pass uses a conservative
572 * transfer length of 36 unless sdev->inquiry_len specifies a
573 * different value. */
574 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
575 try_inquiry_len = first_inquiry_len;
576 pass = 1;
577
578 next_pass:
579 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
580 "scsi scan: INQUIRY pass %d length %d\n",
581 pass, try_inquiry_len));
582
583 /* Each pass gets up to three chances to ignore Unit Attention */
584 for (count = 0; count < 3; ++count) {
585 int resid;
586
587 memset(scsi_cmd, 0, 6);
588 scsi_cmd[0] = INQUIRY;
589 scsi_cmd[4] = (unsigned char) try_inquiry_len;
590
591 memset(inq_result, 0, try_inquiry_len);
592
593 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
594 inq_result, try_inquiry_len, &sshdr,
595 HZ / 2 + HZ * scsi_inq_timeout, 3,
596 &resid);
597
598 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
599 "scsi scan: INQUIRY %s with code 0x%x\n",
600 result ? "failed" : "successful", result));
601
602 if (result) {
603 /*
604 * not-ready to ready transition [asc/ascq=0x28/0x0]
605 * or power-on, reset [asc/ascq=0x29/0x0], continue.
606 * INQUIRY should not yield UNIT_ATTENTION
607 * but many buggy devices do so anyway.
608 */
609 if (driver_byte(result) == DRIVER_SENSE &&
610 scsi_sense_valid(&sshdr)) {
611 if ((sshdr.sense_key == UNIT_ATTENTION) &&
612 ((sshdr.asc == 0x28) ||
613 (sshdr.asc == 0x29)) &&
614 (sshdr.ascq == 0))
615 continue;
616 }
617 } else {
618 /*
619 * if nothing was transferred, we try
620 * again. It's a workaround for some USB
621 * devices.
622 */
623 if (resid == try_inquiry_len)
624 continue;
625 }
626 break;
627 }
628
629 if (result == 0) {
630 scsi_sanitize_inquiry_string(&inq_result[8], 8);
631 scsi_sanitize_inquiry_string(&inq_result[16], 16);
632 scsi_sanitize_inquiry_string(&inq_result[32], 4);
633
634 response_len = inq_result[4] + 5;
635 if (response_len > 255)
636 response_len = first_inquiry_len; /* sanity */
637
638 /*
639 * Get any flags for this device.
640 *
641 * XXX add a bflags to scsi_device, and replace the
642 * corresponding bit fields in scsi_device, so bflags
643 * need not be passed as an argument.
644 */
645 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
646 &inq_result[16]);
647
648 /* When the first pass succeeds we gain information about
649 * what larger transfer lengths might work. */
650 if (pass == 1) {
651 if (BLIST_INQUIRY_36 & *bflags)
652 next_inquiry_len = 36;
653 else if (sdev->inquiry_len)
654 next_inquiry_len = sdev->inquiry_len;
655 else
656 next_inquiry_len = response_len;
657
658 /* If more data is available perform the second pass */
659 if (next_inquiry_len > try_inquiry_len) {
660 try_inquiry_len = next_inquiry_len;
661 pass = 2;
662 goto next_pass;
663 }
664 }
665
666 } else if (pass == 2) {
667 sdev_printk(KERN_INFO, sdev,
668 "scsi scan: %d byte inquiry failed. "
669 "Consider BLIST_INQUIRY_36 for this device\n",
670 try_inquiry_len);
671
672 /* If this pass failed, the third pass goes back and transfers
673 * the same amount as we successfully got in the first pass. */
674 try_inquiry_len = first_inquiry_len;
675 pass = 3;
676 goto next_pass;
677 }
678
679 /* If the last transfer attempt got an error, assume the
680 * peripheral doesn't exist or is dead. */
681 if (result)
682 return -EIO;
683
684 /* Don't report any more data than the device says is valid */
685 sdev->inquiry_len = min(try_inquiry_len, response_len);
686
687 /*
688 * XXX Abort if the response length is less than 36? If less than
689 * 32, the lookup of the device flags (above) could be invalid,
690 * and it would be possible to take an incorrect action - we do
691 * not want to hang because of a short INQUIRY. On the flip side,
692 * if the device is spun down or becoming ready (and so it gives a
693 * short INQUIRY), an abort here prevents any further use of the
694 * device, including spin up.
695 *
696 * On the whole, the best approach seems to be to assume the first
697 * 36 bytes are valid no matter what the device says. That's
698 * better than copying < 36 bytes to the inquiry-result buffer
699 * and displaying garbage for the Vendor, Product, or Revision
700 * strings.
701 */
702 if (sdev->inquiry_len < 36) {
703 if (!sdev->host->short_inquiry) {
704 shost_printk(KERN_INFO, sdev->host,
705 "scsi scan: INQUIRY result too short (%d),"
706 " using 36\n", sdev->inquiry_len);
707 sdev->host->short_inquiry = 1;
708 }
709 sdev->inquiry_len = 36;
710 }
711
712 /*
713 * Related to the above issue:
714 *
715 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
716 * and if not ready, sent a START_STOP to start (maybe spin up) and
717 * then send the INQUIRY again, since the INQUIRY can change after
718 * a device is initialized.
719 *
720 * Ideally, start a device if explicitly asked to do so. This
721 * assumes that a device is spun up on power on, spun down on
722 * request, and then spun up on request.
723 */
724
725 /*
726 * The scanning code needs to know the scsi_level, even if no
727 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
728 * non-zero LUNs can be scanned.
729 */
730 sdev->scsi_level = inq_result[2] & 0x07;
731 if (sdev->scsi_level >= 2 ||
732 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
733 sdev->scsi_level++;
734 sdev->sdev_target->scsi_level = sdev->scsi_level;
735
736 /*
737 * If SCSI-2 or lower, and if the transport requires it,
738 * store the LUN value in CDB[1].
739 */
740 sdev->lun_in_cdb = 0;
741 if (sdev->scsi_level <= SCSI_2 &&
742 sdev->scsi_level != SCSI_UNKNOWN &&
743 !sdev->host->no_scsi2_lun_in_cdb)
744 sdev->lun_in_cdb = 1;
745
746 return 0;
747 }
748
749 /**
750 * scsi_add_lun - allocate and fully initialze a scsi_device
751 * @sdev: holds information to be stored in the new scsi_device
752 * @inq_result: holds the result of a previous INQUIRY to the LUN
753 * @bflags: black/white list flag
754 * @async: 1 if this device is being scanned asynchronously
755 *
756 * Description:
757 * Initialize the scsi_device @sdev. Optionally set fields based
758 * on values in *@bflags.
759 *
760 * Return:
761 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
762 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
763 **/
764 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
765 blist_flags_t *bflags, int async)
766 {
767 int ret;
768
769 /*
770 * XXX do not save the inquiry, since it can change underneath us,
771 * save just vendor/model/rev.
772 *
773 * Rather than save it and have an ioctl that retrieves the saved
774 * value, have an ioctl that executes the same INQUIRY code used
775 * in scsi_probe_lun, let user level programs doing INQUIRY
776 * scanning run at their own risk, or supply a user level program
777 * that can correctly scan.
778 */
779
780 /*
781 * Copy at least 36 bytes of INQUIRY data, so that we don't
782 * dereference unallocated memory when accessing the Vendor,
783 * Product, and Revision strings. Badly behaved devices may set
784 * the INQUIRY Additional Length byte to a small value, indicating
785 * these strings are invalid, but often they contain plausible data
786 * nonetheless. It doesn't matter if the device sent < 36 bytes
787 * total, since scsi_probe_lun() initializes inq_result with 0s.
788 */
789 sdev->inquiry = kmemdup(inq_result,
790 max_t(size_t, sdev->inquiry_len, 36),
791 GFP_KERNEL);
792 if (sdev->inquiry == NULL)
793 return SCSI_SCAN_NO_RESPONSE;
794
795 sdev->vendor = (char *) (sdev->inquiry + 8);
796 sdev->model = (char *) (sdev->inquiry + 16);
797 sdev->rev = (char *) (sdev->inquiry + 32);
798
799 if (strncmp(sdev->vendor, "ATA ", 8) == 0) {
800 /*
801 * sata emulation layer device. This is a hack to work around
802 * the SATL power management specifications which state that
803 * when the SATL detects the device has gone into standby
804 * mode, it shall respond with NOT READY.
805 */
806 sdev->allow_restart = 1;
807 }
808
809 if (*bflags & BLIST_ISROM) {
810 sdev->type = TYPE_ROM;
811 sdev->removable = 1;
812 } else {
813 sdev->type = (inq_result[0] & 0x1f);
814 sdev->removable = (inq_result[1] & 0x80) >> 7;
815
816 /*
817 * some devices may respond with wrong type for
818 * well-known logical units. Force well-known type
819 * to enumerate them correctly.
820 */
821 if (scsi_is_wlun(sdev->lun) && sdev->type != TYPE_WLUN) {
822 sdev_printk(KERN_WARNING, sdev,
823 "%s: correcting incorrect peripheral device type 0x%x for W-LUN 0x%16xhN\n",
824 __func__, sdev->type, (unsigned int)sdev->lun);
825 sdev->type = TYPE_WLUN;
826 }
827
828 }
829
830 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
831 /* RBC and MMC devices can return SCSI-3 compliance and yet
832 * still not support REPORT LUNS, so make them act as
833 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
834 * specifically set */
835 if ((*bflags & BLIST_REPORTLUN2) == 0)
836 *bflags |= BLIST_NOREPORTLUN;
837 }
838
839 /*
840 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
841 * spec says: The device server is capable of supporting the
842 * specified peripheral device type on this logical unit. However,
843 * the physical device is not currently connected to this logical
844 * unit.
845 *
846 * The above is vague, as it implies that we could treat 001 and
847 * 011 the same. Stay compatible with previous code, and create a
848 * scsi_device for a PQ of 1
849 *
850 * Don't set the device offline here; rather let the upper
851 * level drivers eval the PQ to decide whether they should
852 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
853 */
854
855 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
856 sdev->lockable = sdev->removable;
857 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
858
859 if (sdev->scsi_level >= SCSI_3 ||
860 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
861 sdev->ppr = 1;
862 if (inq_result[7] & 0x60)
863 sdev->wdtr = 1;
864 if (inq_result[7] & 0x10)
865 sdev->sdtr = 1;
866
867 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
868 "ANSI: %d%s\n", scsi_device_type(sdev->type),
869 sdev->vendor, sdev->model, sdev->rev,
870 sdev->inq_periph_qual, inq_result[2] & 0x07,
871 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
872
873 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
874 !(*bflags & BLIST_NOTQ)) {
875 sdev->tagged_supported = 1;
876 sdev->simple_tags = 1;
877 }
878
879 /*
880 * Some devices (Texel CD ROM drives) have handshaking problems
881 * when used with the Seagate controllers. borken is initialized
882 * to 1, and then set it to 0 here.
883 */
884 if ((*bflags & BLIST_BORKEN) == 0)
885 sdev->borken = 0;
886
887 if (*bflags & BLIST_NO_ULD_ATTACH)
888 sdev->no_uld_attach = 1;
889
890 /*
891 * Apparently some really broken devices (contrary to the SCSI
892 * standards) need to be selected without asserting ATN
893 */
894 if (*bflags & BLIST_SELECT_NO_ATN)
895 sdev->select_no_atn = 1;
896
897 /*
898 * Maximum 512 sector transfer length
899 * broken RA4x00 Compaq Disk Array
900 */
901 if (*bflags & BLIST_MAX_512)
902 blk_queue_max_hw_sectors(sdev->request_queue, 512);
903 /*
904 * Max 1024 sector transfer length for targets that report incorrect
905 * max/optimal lengths and relied on the old block layer safe default
906 */
907 else if (*bflags & BLIST_MAX_1024)
908 blk_queue_max_hw_sectors(sdev->request_queue, 1024);
909
910 /*
911 * Some devices may not want to have a start command automatically
912 * issued when a device is added.
913 */
914 if (*bflags & BLIST_NOSTARTONADD)
915 sdev->no_start_on_add = 1;
916
917 if (*bflags & BLIST_SINGLELUN)
918 scsi_target(sdev)->single_lun = 1;
919
920 sdev->use_10_for_rw = 1;
921
922 /* some devices don't like REPORT SUPPORTED OPERATION CODES
923 * and will simply timeout causing sd_mod init to take a very
924 * very long time */
925 if (*bflags & BLIST_NO_RSOC)
926 sdev->no_report_opcodes = 1;
927
928 /* set the device running here so that slave configure
929 * may do I/O */
930 mutex_lock(&sdev->state_mutex);
931 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
932 if (ret)
933 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
934 mutex_unlock(&sdev->state_mutex);
935
936 if (ret) {
937 sdev_printk(KERN_ERR, sdev,
938 "in wrong state %s to complete scan\n",
939 scsi_device_state_name(sdev->sdev_state));
940 return SCSI_SCAN_NO_RESPONSE;
941 }
942
943 if (*bflags & BLIST_NOT_LOCKABLE)
944 sdev->lockable = 0;
945
946 if (*bflags & BLIST_RETRY_HWERROR)
947 sdev->retry_hwerror = 1;
948
949 if (*bflags & BLIST_NO_DIF)
950 sdev->no_dif = 1;
951
952 if (*bflags & BLIST_UNMAP_LIMIT_WS)
953 sdev->unmap_limit_for_ws = 1;
954
955 sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT;
956
957 if (*bflags & BLIST_TRY_VPD_PAGES)
958 sdev->try_vpd_pages = 1;
959 else if (*bflags & BLIST_SKIP_VPD_PAGES)
960 sdev->skip_vpd_pages = 1;
961
962 transport_configure_device(&sdev->sdev_gendev);
963
964 if (sdev->host->hostt->slave_configure) {
965 ret = sdev->host->hostt->slave_configure(sdev);
966 if (ret) {
967 /*
968 * if LLDD reports slave not present, don't clutter
969 * console with alloc failure messages
970 */
971 if (ret != -ENXIO) {
972 sdev_printk(KERN_ERR, sdev,
973 "failed to configure device\n");
974 }
975 return SCSI_SCAN_NO_RESPONSE;
976 }
977 }
978
979 if (sdev->scsi_level >= SCSI_3)
980 scsi_attach_vpd(sdev);
981
982 sdev->max_queue_depth = sdev->queue_depth;
983 sdev->sdev_bflags = *bflags;
984
985 /*
986 * Ok, the device is now all set up, we can
987 * register it and tell the rest of the kernel
988 * about it.
989 */
990 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
991 return SCSI_SCAN_NO_RESPONSE;
992
993 return SCSI_SCAN_LUN_PRESENT;
994 }
995
996 #ifdef CONFIG_SCSI_LOGGING
997 /**
998 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
999 * @buf: Output buffer with at least end-first+1 bytes of space
1000 * @inq: Inquiry buffer (input)
1001 * @first: Offset of string into inq
1002 * @end: Index after last character in inq
1003 */
1004 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
1005 unsigned first, unsigned end)
1006 {
1007 unsigned term = 0, idx;
1008
1009 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
1010 if (inq[idx+first] > ' ') {
1011 buf[idx] = inq[idx+first];
1012 term = idx+1;
1013 } else {
1014 buf[idx] = ' ';
1015 }
1016 }
1017 buf[term] = 0;
1018 return buf;
1019 }
1020 #endif
1021
1022 /**
1023 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
1024 * @starget: pointer to target device structure
1025 * @lun: LUN of target device
1026 * @bflagsp: store bflags here if not NULL
1027 * @sdevp: probe the LUN corresponding to this scsi_device
1028 * @rescan: if not equal to SCSI_SCAN_INITIAL skip some code only
1029 * needed on first scan
1030 * @hostdata: passed to scsi_alloc_sdev()
1031 *
1032 * Description:
1033 * Call scsi_probe_lun, if a LUN with an attached device is found,
1034 * allocate and set it up by calling scsi_add_lun.
1035 *
1036 * Return:
1037 *
1038 * - SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1039 * - SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1040 * attached at the LUN
1041 * - SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1042 **/
1043 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1044 u64 lun, blist_flags_t *bflagsp,
1045 struct scsi_device **sdevp,
1046 enum scsi_scan_mode rescan,
1047 void *hostdata)
1048 {
1049 struct scsi_device *sdev;
1050 unsigned char *result;
1051 blist_flags_t bflags;
1052 int res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1053 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1054
1055 /*
1056 * The rescan flag is used as an optimization, the first scan of a
1057 * host adapter calls into here with rescan == 0.
1058 */
1059 sdev = scsi_device_lookup_by_target(starget, lun);
1060 if (sdev) {
1061 if (rescan != SCSI_SCAN_INITIAL || !scsi_device_created(sdev)) {
1062 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1063 "scsi scan: device exists on %s\n",
1064 dev_name(&sdev->sdev_gendev)));
1065 if (sdevp)
1066 *sdevp = sdev;
1067 else
1068 scsi_device_put(sdev);
1069
1070 if (bflagsp)
1071 *bflagsp = scsi_get_device_flags(sdev,
1072 sdev->vendor,
1073 sdev->model);
1074 return SCSI_SCAN_LUN_PRESENT;
1075 }
1076 scsi_device_put(sdev);
1077 } else
1078 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1079 if (!sdev)
1080 goto out;
1081
1082 result = kmalloc(result_len, GFP_KERNEL |
1083 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1084 if (!result)
1085 goto out_free_sdev;
1086
1087 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1088 goto out_free_result;
1089
1090 if (bflagsp)
1091 *bflagsp = bflags;
1092 /*
1093 * result contains valid SCSI INQUIRY data.
1094 */
1095 if ((result[0] >> 5) == 3) {
1096 /*
1097 * For a Peripheral qualifier 3 (011b), the SCSI
1098 * spec says: The device server is not capable of
1099 * supporting a physical device on this logical
1100 * unit.
1101 *
1102 * For disks, this implies that there is no
1103 * logical disk configured at sdev->lun, but there
1104 * is a target id responding.
1105 */
1106 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1107 " peripheral qualifier of 3, device not"
1108 " added\n"))
1109 if (lun == 0) {
1110 SCSI_LOG_SCAN_BUS(1, {
1111 unsigned char vend[9];
1112 unsigned char mod[17];
1113
1114 sdev_printk(KERN_INFO, sdev,
1115 "scsi scan: consider passing scsi_mod."
1116 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1117 scsi_inq_str(vend, result, 8, 16),
1118 scsi_inq_str(mod, result, 16, 32));
1119 });
1120
1121 }
1122
1123 res = SCSI_SCAN_TARGET_PRESENT;
1124 goto out_free_result;
1125 }
1126
1127 /*
1128 * Some targets may set slight variations of PQ and PDT to signal
1129 * that no LUN is present, so don't add sdev in these cases.
1130 * Two specific examples are:
1131 * 1) NetApp targets: return PQ=1, PDT=0x1f
1132 * 2) IBM/2145 targets: return PQ=1, PDT=0
1133 * 3) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1134 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1135 *
1136 * References:
1137 * 1) SCSI SPC-3, pp. 145-146
1138 * PQ=1: "A peripheral device having the specified peripheral
1139 * device type is not connected to this logical unit. However, the
1140 * device server is capable of supporting the specified peripheral
1141 * device type on this logical unit."
1142 * PDT=0x1f: "Unknown or no device type"
1143 * 2) USB UFI 1.0, p. 20
1144 * PDT=00h Direct-access device (floppy)
1145 * PDT=1Fh none (no FDD connected to the requested logical unit)
1146 */
1147 if (((result[0] >> 5) == 1 ||
1148 (starget->pdt_1f_for_no_lun && (result[0] & 0x1f) == 0x1f)) &&
1149 !scsi_is_wlun(lun)) {
1150 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
1151 "scsi scan: peripheral device type"
1152 " of 31, no device added\n"));
1153 res = SCSI_SCAN_TARGET_PRESENT;
1154 goto out_free_result;
1155 }
1156
1157 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1158 if (res == SCSI_SCAN_LUN_PRESENT) {
1159 if (bflags & BLIST_KEY) {
1160 sdev->lockable = 0;
1161 scsi_unlock_floptical(sdev, result);
1162 }
1163 }
1164
1165 out_free_result:
1166 kfree(result);
1167 out_free_sdev:
1168 if (res == SCSI_SCAN_LUN_PRESENT) {
1169 if (sdevp) {
1170 if (scsi_device_get(sdev) == 0) {
1171 *sdevp = sdev;
1172 } else {
1173 __scsi_remove_device(sdev);
1174 res = SCSI_SCAN_NO_RESPONSE;
1175 }
1176 }
1177 } else
1178 __scsi_remove_device(sdev);
1179 out:
1180 return res;
1181 }
1182
1183 /**
1184 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1185 * @starget: pointer to target structure to scan
1186 * @bflags: black/white list flag for LUN 0
1187 * @scsi_level: Which version of the standard does this device adhere to
1188 * @rescan: passed to scsi_probe_add_lun()
1189 *
1190 * Description:
1191 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1192 * scanned) to some maximum lun until a LUN is found with no device
1193 * attached. Use the bflags to figure out any oddities.
1194 *
1195 * Modifies sdevscan->lun.
1196 **/
1197 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1198 blist_flags_t bflags, int scsi_level,
1199 enum scsi_scan_mode rescan)
1200 {
1201 uint max_dev_lun;
1202 u64 sparse_lun, lun;
1203 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1204
1205 SCSI_LOG_SCAN_BUS(3, starget_printk(KERN_INFO, starget,
1206 "scsi scan: Sequential scan\n"));
1207
1208 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1209 /*
1210 * If this device is known to support sparse multiple units,
1211 * override the other settings, and scan all of them. Normally,
1212 * SCSI-3 devices should be scanned via the REPORT LUNS.
1213 */
1214 if (bflags & BLIST_SPARSELUN) {
1215 max_dev_lun = shost->max_lun;
1216 sparse_lun = 1;
1217 } else
1218 sparse_lun = 0;
1219
1220 /*
1221 * If less than SCSI_1_CCS, and no special lun scanning, stop
1222 * scanning; this matches 2.4 behaviour, but could just be a bug
1223 * (to continue scanning a SCSI_1_CCS device).
1224 *
1225 * This test is broken. We might not have any device on lun0 for
1226 * a sparselun device, and if that's the case then how would we
1227 * know the real scsi_level, eh? It might make sense to just not
1228 * scan any SCSI_1 device for non-0 luns, but that check would best
1229 * go into scsi_alloc_sdev() and just have it return null when asked
1230 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1231 *
1232 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1233 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1234 == 0))
1235 return;
1236 */
1237 /*
1238 * If this device is known to support multiple units, override
1239 * the other settings, and scan all of them.
1240 */
1241 if (bflags & BLIST_FORCELUN)
1242 max_dev_lun = shost->max_lun;
1243 /*
1244 * REGAL CDC-4X: avoid hang after LUN 4
1245 */
1246 if (bflags & BLIST_MAX5LUN)
1247 max_dev_lun = min(5U, max_dev_lun);
1248 /*
1249 * Do not scan SCSI-2 or lower device past LUN 7, unless
1250 * BLIST_LARGELUN.
1251 */
1252 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1253 max_dev_lun = min(8U, max_dev_lun);
1254 else
1255 max_dev_lun = min(256U, max_dev_lun);
1256
1257 /*
1258 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1259 * until we reach the max, or no LUN is found and we are not
1260 * sparse_lun.
1261 */
1262 for (lun = 1; lun < max_dev_lun; ++lun)
1263 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1264 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1265 !sparse_lun)
1266 return;
1267 }
1268
1269 /**
1270 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1271 * @starget: which target
1272 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1273 * @rescan: nonzero if we can skip code only needed on first scan
1274 *
1275 * Description:
1276 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1277 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1278 *
1279 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1280 * LUNs even if it's older than SCSI-3.
1281 * If BLIST_NOREPORTLUN is set, return 1 always.
1282 * If BLIST_NOLUN is set, return 0 always.
1283 * If starget->no_report_luns is set, return 1 always.
1284 *
1285 * Return:
1286 * 0: scan completed (or no memory, so further scanning is futile)
1287 * 1: could not scan with REPORT LUN
1288 **/
1289 static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflags,
1290 enum scsi_scan_mode rescan)
1291 {
1292 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1293 unsigned int length;
1294 u64 lun;
1295 unsigned int num_luns;
1296 unsigned int retries;
1297 int result;
1298 struct scsi_lun *lunp, *lun_data;
1299 struct scsi_sense_hdr sshdr;
1300 struct scsi_device *sdev;
1301 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1302 int ret = 0;
1303
1304 /*
1305 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1306 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1307 * support more than 8 LUNs.
1308 * Don't attempt if the target doesn't support REPORT LUNS.
1309 */
1310 if (bflags & BLIST_NOREPORTLUN)
1311 return 1;
1312 if (starget->scsi_level < SCSI_2 &&
1313 starget->scsi_level != SCSI_UNKNOWN)
1314 return 1;
1315 if (starget->scsi_level < SCSI_3 &&
1316 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1317 return 1;
1318 if (bflags & BLIST_NOLUN)
1319 return 0;
1320 if (starget->no_report_luns)
1321 return 1;
1322
1323 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1324 sdev = scsi_alloc_sdev(starget, 0, NULL);
1325 if (!sdev)
1326 return 0;
1327 if (scsi_device_get(sdev)) {
1328 __scsi_remove_device(sdev);
1329 return 0;
1330 }
1331 }
1332
1333 /*
1334 * Allocate enough to hold the header (the same size as one scsi_lun)
1335 * plus the number of luns we are requesting. 511 was the default
1336 * value of the now removed max_report_luns parameter.
1337 */
1338 length = (511 + 1) * sizeof(struct scsi_lun);
1339 retry:
1340 lun_data = kmalloc(length, GFP_KERNEL |
1341 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1342 if (!lun_data) {
1343 printk(ALLOC_FAILURE_MSG, __func__);
1344 goto out;
1345 }
1346
1347 scsi_cmd[0] = REPORT_LUNS;
1348
1349 /*
1350 * bytes 1 - 5: reserved, set to zero.
1351 */
1352 memset(&scsi_cmd[1], 0, 5);
1353
1354 /*
1355 * bytes 6 - 9: length of the command.
1356 */
1357 put_unaligned_be32(length, &scsi_cmd[6]);
1358
1359 scsi_cmd[10] = 0; /* reserved */
1360 scsi_cmd[11] = 0; /* control */
1361
1362 /*
1363 * We can get a UNIT ATTENTION, for example a power on/reset, so
1364 * retry a few times (like sd.c does for TEST UNIT READY).
1365 * Experience shows some combinations of adapter/devices get at
1366 * least two power on/resets.
1367 *
1368 * Illegal requests (for devices that do not support REPORT LUNS)
1369 * should come through as a check condition, and will not generate
1370 * a retry.
1371 */
1372 for (retries = 0; retries < 3; retries++) {
1373 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1374 "scsi scan: Sending REPORT LUNS to (try %d)\n",
1375 retries));
1376
1377 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1378 lun_data, length, &sshdr,
1379 SCSI_REPORT_LUNS_TIMEOUT, 3, NULL);
1380
1381 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1382 "scsi scan: REPORT LUNS"
1383 " %s (try %d) result 0x%x\n",
1384 result ? "failed" : "successful",
1385 retries, result));
1386 if (result == 0)
1387 break;
1388 else if (scsi_sense_valid(&sshdr)) {
1389 if (sshdr.sense_key != UNIT_ATTENTION)
1390 break;
1391 }
1392 }
1393
1394 if (result) {
1395 /*
1396 * The device probably does not support a REPORT LUN command
1397 */
1398 ret = 1;
1399 goto out_err;
1400 }
1401
1402 /*
1403 * Get the length from the first four bytes of lun_data.
1404 */
1405 if (get_unaligned_be32(lun_data->scsi_lun) +
1406 sizeof(struct scsi_lun) > length) {
1407 length = get_unaligned_be32(lun_data->scsi_lun) +
1408 sizeof(struct scsi_lun);
1409 kfree(lun_data);
1410 goto retry;
1411 }
1412 length = get_unaligned_be32(lun_data->scsi_lun);
1413
1414 num_luns = (length / sizeof(struct scsi_lun));
1415
1416 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1417 "scsi scan: REPORT LUN scan\n"));
1418
1419 /*
1420 * Scan the luns in lun_data. The entry at offset 0 is really
1421 * the header, so start at 1 and go up to and including num_luns.
1422 */
1423 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1424 lun = scsilun_to_int(lunp);
1425
1426 if (lun > sdev->host->max_lun) {
1427 sdev_printk(KERN_WARNING, sdev,
1428 "lun%llu has a LUN larger than"
1429 " allowed by the host adapter\n", lun);
1430 } else {
1431 int res;
1432
1433 res = scsi_probe_and_add_lun(starget,
1434 lun, NULL, NULL, rescan, NULL);
1435 if (res == SCSI_SCAN_NO_RESPONSE) {
1436 /*
1437 * Got some results, but now none, abort.
1438 */
1439 sdev_printk(KERN_ERR, sdev,
1440 "Unexpected response"
1441 " from lun %llu while scanning, scan"
1442 " aborted\n", (unsigned long long)lun);
1443 break;
1444 }
1445 }
1446 }
1447
1448 out_err:
1449 kfree(lun_data);
1450 out:
1451 if (scsi_device_created(sdev))
1452 /*
1453 * the sdev we used didn't appear in the report luns scan
1454 */
1455 __scsi_remove_device(sdev);
1456 scsi_device_put(sdev);
1457 return ret;
1458 }
1459
1460 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1461 uint id, u64 lun, void *hostdata)
1462 {
1463 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1464 struct device *parent = &shost->shost_gendev;
1465 struct scsi_target *starget;
1466
1467 if (strncmp(scsi_scan_type, "none", 4) == 0)
1468 return ERR_PTR(-ENODEV);
1469
1470 starget = scsi_alloc_target(parent, channel, id);
1471 if (!starget)
1472 return ERR_PTR(-ENOMEM);
1473 scsi_autopm_get_target(starget);
1474
1475 mutex_lock(&shost->scan_mutex);
1476 if (!shost->async_scan)
1477 scsi_complete_async_scans();
1478
1479 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1480 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1481 scsi_autopm_put_host(shost);
1482 }
1483 mutex_unlock(&shost->scan_mutex);
1484 scsi_autopm_put_target(starget);
1485 /*
1486 * paired with scsi_alloc_target(). Target will be destroyed unless
1487 * scsi_probe_and_add_lun made an underlying device visible
1488 */
1489 scsi_target_reap(starget);
1490 put_device(&starget->dev);
1491
1492 return sdev;
1493 }
1494 EXPORT_SYMBOL(__scsi_add_device);
1495
1496 int scsi_add_device(struct Scsi_Host *host, uint channel,
1497 uint target, u64 lun)
1498 {
1499 struct scsi_device *sdev =
1500 __scsi_add_device(host, channel, target, lun, NULL);
1501 if (IS_ERR(sdev))
1502 return PTR_ERR(sdev);
1503
1504 scsi_device_put(sdev);
1505 return 0;
1506 }
1507 EXPORT_SYMBOL(scsi_add_device);
1508
1509 void scsi_rescan_device(struct device *dev)
1510 {
1511 struct scsi_device *sdev = to_scsi_device(dev);
1512
1513 device_lock(dev);
1514
1515 scsi_attach_vpd(sdev);
1516
1517 if (sdev->handler && sdev->handler->rescan)
1518 sdev->handler->rescan(sdev);
1519
1520 if (dev->driver && try_module_get(dev->driver->owner)) {
1521 struct scsi_driver *drv = to_scsi_driver(dev->driver);
1522
1523 if (drv->rescan)
1524 drv->rescan(dev);
1525 module_put(dev->driver->owner);
1526 }
1527 device_unlock(dev);
1528 }
1529 EXPORT_SYMBOL(scsi_rescan_device);
1530
1531 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1532 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1533 {
1534 struct Scsi_Host *shost = dev_to_shost(parent);
1535 blist_flags_t bflags = 0;
1536 int res;
1537 struct scsi_target *starget;
1538
1539 if (shost->this_id == id)
1540 /*
1541 * Don't scan the host adapter
1542 */
1543 return;
1544
1545 starget = scsi_alloc_target(parent, channel, id);
1546 if (!starget)
1547 return;
1548 scsi_autopm_get_target(starget);
1549
1550 if (lun != SCAN_WILD_CARD) {
1551 /*
1552 * Scan for a specific host/chan/id/lun.
1553 */
1554 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1555 goto out_reap;
1556 }
1557
1558 /*
1559 * Scan LUN 0, if there is some response, scan further. Ideally, we
1560 * would not configure LUN 0 until all LUNs are scanned.
1561 */
1562 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1563 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1564 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1565 /*
1566 * The REPORT LUN did not scan the target,
1567 * do a sequential scan.
1568 */
1569 scsi_sequential_lun_scan(starget, bflags,
1570 starget->scsi_level, rescan);
1571 }
1572
1573 out_reap:
1574 scsi_autopm_put_target(starget);
1575 /*
1576 * paired with scsi_alloc_target(): determine if the target has
1577 * any children at all and if not, nuke it
1578 */
1579 scsi_target_reap(starget);
1580
1581 put_device(&starget->dev);
1582 }
1583
1584 /**
1585 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1586 * @parent: host to scan
1587 * @channel: channel to scan
1588 * @id: target id to scan
1589 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1590 * @rescan: passed to LUN scanning routines; SCSI_SCAN_INITIAL for
1591 * no rescan, SCSI_SCAN_RESCAN to rescan existing LUNs,
1592 * and SCSI_SCAN_MANUAL to force scanning even if
1593 * 'scan=manual' is set.
1594 *
1595 * Description:
1596 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1597 * and possibly all LUNs on the target id.
1598 *
1599 * First try a REPORT LUN scan, if that does not scan the target, do a
1600 * sequential scan of LUNs on the target id.
1601 **/
1602 void scsi_scan_target(struct device *parent, unsigned int channel,
1603 unsigned int id, u64 lun, enum scsi_scan_mode rescan)
1604 {
1605 struct Scsi_Host *shost = dev_to_shost(parent);
1606
1607 if (strncmp(scsi_scan_type, "none", 4) == 0)
1608 return;
1609
1610 if (rescan != SCSI_SCAN_MANUAL &&
1611 strncmp(scsi_scan_type, "manual", 6) == 0)
1612 return;
1613
1614 mutex_lock(&shost->scan_mutex);
1615 if (!shost->async_scan)
1616 scsi_complete_async_scans();
1617
1618 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1619 __scsi_scan_target(parent, channel, id, lun, rescan);
1620 scsi_autopm_put_host(shost);
1621 }
1622 mutex_unlock(&shost->scan_mutex);
1623 }
1624 EXPORT_SYMBOL(scsi_scan_target);
1625
1626 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1627 unsigned int id, u64 lun,
1628 enum scsi_scan_mode rescan)
1629 {
1630 uint order_id;
1631
1632 if (id == SCAN_WILD_CARD)
1633 for (id = 0; id < shost->max_id; ++id) {
1634 /*
1635 * XXX adapter drivers when possible (FCP, iSCSI)
1636 * could modify max_id to match the current max,
1637 * not the absolute max.
1638 *
1639 * XXX add a shost id iterator, so for example,
1640 * the FC ID can be the same as a target id
1641 * without a huge overhead of sparse id's.
1642 */
1643 if (shost->reverse_ordering)
1644 /*
1645 * Scan from high to low id.
1646 */
1647 order_id = shost->max_id - id - 1;
1648 else
1649 order_id = id;
1650 __scsi_scan_target(&shost->shost_gendev, channel,
1651 order_id, lun, rescan);
1652 }
1653 else
1654 __scsi_scan_target(&shost->shost_gendev, channel,
1655 id, lun, rescan);
1656 }
1657
1658 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1659 unsigned int id, u64 lun,
1660 enum scsi_scan_mode rescan)
1661 {
1662 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1663 "%s: <%u:%u:%llu>\n",
1664 __func__, channel, id, lun));
1665
1666 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1667 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1668 ((lun != SCAN_WILD_CARD) && (lun >= shost->max_lun)))
1669 return -EINVAL;
1670
1671 mutex_lock(&shost->scan_mutex);
1672 if (!shost->async_scan)
1673 scsi_complete_async_scans();
1674
1675 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1676 if (channel == SCAN_WILD_CARD)
1677 for (channel = 0; channel <= shost->max_channel;
1678 channel++)
1679 scsi_scan_channel(shost, channel, id, lun,
1680 rescan);
1681 else
1682 scsi_scan_channel(shost, channel, id, lun, rescan);
1683 scsi_autopm_put_host(shost);
1684 }
1685 mutex_unlock(&shost->scan_mutex);
1686
1687 return 0;
1688 }
1689
1690 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1691 {
1692 struct scsi_device *sdev;
1693 shost_for_each_device(sdev, shost) {
1694 /* target removed before the device could be added */
1695 if (sdev->sdev_state == SDEV_DEL)
1696 continue;
1697 /* If device is already visible, skip adding it to sysfs */
1698 if (sdev->is_visible)
1699 continue;
1700 if (!scsi_host_scan_allowed(shost) ||
1701 scsi_sysfs_add_sdev(sdev) != 0)
1702 __scsi_remove_device(sdev);
1703 }
1704 }
1705
1706 /**
1707 * scsi_prep_async_scan - prepare for an async scan
1708 * @shost: the host which will be scanned
1709 * Returns: a cookie to be passed to scsi_finish_async_scan()
1710 *
1711 * Tells the midlayer this host is going to do an asynchronous scan.
1712 * It reserves the host's position in the scanning list and ensures
1713 * that other asynchronous scans started after this one won't affect the
1714 * ordering of the discovered devices.
1715 */
1716 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1717 {
1718 struct async_scan_data *data;
1719 unsigned long flags;
1720
1721 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1722 return NULL;
1723
1724 if (shost->async_scan) {
1725 shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__);
1726 return NULL;
1727 }
1728
1729 data = kmalloc(sizeof(*data), GFP_KERNEL);
1730 if (!data)
1731 goto err;
1732 data->shost = scsi_host_get(shost);
1733 if (!data->shost)
1734 goto err;
1735 init_completion(&data->prev_finished);
1736
1737 mutex_lock(&shost->scan_mutex);
1738 spin_lock_irqsave(shost->host_lock, flags);
1739 shost->async_scan = 1;
1740 spin_unlock_irqrestore(shost->host_lock, flags);
1741 mutex_unlock(&shost->scan_mutex);
1742
1743 spin_lock(&async_scan_lock);
1744 if (list_empty(&scanning_hosts))
1745 complete(&data->prev_finished);
1746 list_add_tail(&data->list, &scanning_hosts);
1747 spin_unlock(&async_scan_lock);
1748
1749 return data;
1750
1751 err:
1752 kfree(data);
1753 return NULL;
1754 }
1755
1756 /**
1757 * scsi_finish_async_scan - asynchronous scan has finished
1758 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1759 *
1760 * All the devices currently attached to this host have been found.
1761 * This function announces all the devices it has found to the rest
1762 * of the system.
1763 */
1764 static void scsi_finish_async_scan(struct async_scan_data *data)
1765 {
1766 struct Scsi_Host *shost;
1767 unsigned long flags;
1768
1769 if (!data)
1770 return;
1771
1772 shost = data->shost;
1773
1774 mutex_lock(&shost->scan_mutex);
1775
1776 if (!shost->async_scan) {
1777 shost_printk(KERN_INFO, shost, "%s called twice\n", __func__);
1778 dump_stack();
1779 mutex_unlock(&shost->scan_mutex);
1780 return;
1781 }
1782
1783 wait_for_completion(&data->prev_finished);
1784
1785 scsi_sysfs_add_devices(shost);
1786
1787 spin_lock_irqsave(shost->host_lock, flags);
1788 shost->async_scan = 0;
1789 spin_unlock_irqrestore(shost->host_lock, flags);
1790
1791 mutex_unlock(&shost->scan_mutex);
1792
1793 spin_lock(&async_scan_lock);
1794 list_del(&data->list);
1795 if (!list_empty(&scanning_hosts)) {
1796 struct async_scan_data *next = list_entry(scanning_hosts.next,
1797 struct async_scan_data, list);
1798 complete(&next->prev_finished);
1799 }
1800 spin_unlock(&async_scan_lock);
1801
1802 scsi_autopm_put_host(shost);
1803 scsi_host_put(shost);
1804 kfree(data);
1805 }
1806
1807 static void do_scsi_scan_host(struct Scsi_Host *shost)
1808 {
1809 if (shost->hostt->scan_finished) {
1810 unsigned long start = jiffies;
1811 if (shost->hostt->scan_start)
1812 shost->hostt->scan_start(shost);
1813
1814 while (!shost->hostt->scan_finished(shost, jiffies - start))
1815 msleep(10);
1816 } else {
1817 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1818 SCAN_WILD_CARD, 0);
1819 }
1820 }
1821
1822 static void do_scan_async(void *_data, async_cookie_t c)
1823 {
1824 struct async_scan_data *data = _data;
1825 struct Scsi_Host *shost = data->shost;
1826
1827 do_scsi_scan_host(shost);
1828 scsi_finish_async_scan(data);
1829 }
1830
1831 /**
1832 * scsi_scan_host - scan the given adapter
1833 * @shost: adapter to scan
1834 **/
1835 void scsi_scan_host(struct Scsi_Host *shost)
1836 {
1837 struct async_scan_data *data;
1838
1839 if (strncmp(scsi_scan_type, "none", 4) == 0 ||
1840 strncmp(scsi_scan_type, "manual", 6) == 0)
1841 return;
1842 if (scsi_autopm_get_host(shost) < 0)
1843 return;
1844
1845 data = scsi_prep_async_scan(shost);
1846 if (!data) {
1847 do_scsi_scan_host(shost);
1848 scsi_autopm_put_host(shost);
1849 return;
1850 }
1851
1852 /* register with the async subsystem so wait_for_device_probe()
1853 * will flush this work
1854 */
1855 async_schedule(do_scan_async, data);
1856
1857 /* scsi_autopm_put_host(shost) is called in scsi_finish_async_scan() */
1858 }
1859 EXPORT_SYMBOL(scsi_scan_host);
1860
1861 void scsi_forget_host(struct Scsi_Host *shost)
1862 {
1863 struct scsi_device *sdev;
1864 unsigned long flags;
1865
1866 restart:
1867 spin_lock_irqsave(shost->host_lock, flags);
1868 list_for_each_entry(sdev, &shost->__devices, siblings) {
1869 if (sdev->sdev_state == SDEV_DEL)
1870 continue;
1871 spin_unlock_irqrestore(shost->host_lock, flags);
1872 __scsi_remove_device(sdev);
1873 goto restart;
1874 }
1875 spin_unlock_irqrestore(shost->host_lock, flags);
1876 }
1877
1878 /**
1879 * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself
1880 * @shost: Host that needs a scsi_device
1881 *
1882 * Lock status: None assumed.
1883 *
1884 * Returns: The scsi_device or NULL
1885 *
1886 * Notes:
1887 * Attach a single scsi_device to the Scsi_Host - this should
1888 * be made to look like a "pseudo-device" that points to the
1889 * HA itself.
1890 *
1891 * Note - this device is not accessible from any high-level
1892 * drivers (including generics), which is probably not
1893 * optimal. We can add hooks later to attach.
1894 */
1895 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1896 {
1897 struct scsi_device *sdev = NULL;
1898 struct scsi_target *starget;
1899
1900 mutex_lock(&shost->scan_mutex);
1901 if (!scsi_host_scan_allowed(shost))
1902 goto out;
1903 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1904 if (!starget)
1905 goto out;
1906
1907 sdev = scsi_alloc_sdev(starget, 0, NULL);
1908 if (sdev)
1909 sdev->borken = 0;
1910 else
1911 scsi_target_reap(starget);
1912 put_device(&starget->dev);
1913 out:
1914 mutex_unlock(&shost->scan_mutex);
1915 return sdev;
1916 }
1917 EXPORT_SYMBOL(scsi_get_host_dev);
1918
1919 /**
1920 * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself
1921 * @sdev: Host device to be freed
1922 *
1923 * Lock status: None assumed.
1924 *
1925 * Returns: Nothing
1926 */
1927 void scsi_free_host_dev(struct scsi_device *sdev)
1928 {
1929 BUG_ON(sdev->id != sdev->host->this_id);
1930
1931 __scsi_remove_device(sdev);
1932 }
1933 EXPORT_SYMBOL(scsi_free_host_dev);
1934