/drivers/scsi/scsi_scan.c
C | 1949 lines | 1090 code | 232 blank | 627 comment | 251 complexity | ccc1a1f556835c46decd7e50c2356b12 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
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1/*
2 * scsi_scan.c
3 *
4 * Copyright (C) 2000 Eric Youngdale,
5 * Copyright (C) 2002 Patrick Mansfield
6 *
7 * The general scanning/probing algorithm is as follows, exceptions are
8 * made to it depending on device specific flags, compilation options, and
9 * global variable (boot or module load time) settings.
10 *
11 * A specific LUN is scanned via an INQUIRY command; if the LUN has a
12 * device attached, a scsi_device is allocated and setup for it.
13 *
14 * For every id of every channel on the given host:
15 *
16 * Scan LUN 0; if the target responds to LUN 0 (even if there is no
17 * device or storage attached to LUN 0):
18 *
19 * If LUN 0 has a device attached, allocate and setup a
20 * scsi_device for it.
21 *
22 * If target is SCSI-3 or up, issue a REPORT LUN, and scan
23 * all of the LUNs returned by the REPORT LUN; else,
24 * sequentially scan LUNs up until some maximum is reached,
25 * or a LUN is seen that cannot have a device attached to it.
26 */
27
28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/init.h>
31#include <linux/blkdev.h>
32#include <linux/delay.h>
33#include <linux/kthread.h>
34#include <linux/spinlock.h>
35#include <linux/async.h>
36#include <linux/slab.h>
37
38#include <scsi/scsi.h>
39#include <scsi/scsi_cmnd.h>
40#include <scsi/scsi_device.h>
41#include <scsi/scsi_driver.h>
42#include <scsi/scsi_devinfo.h>
43#include <scsi/scsi_host.h>
44#include <scsi/scsi_transport.h>
45#include <scsi/scsi_eh.h>
46
47#include "scsi_priv.h"
48#include "scsi_logging.h"
49
50#define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
51 " SCSI scanning, some SCSI devices might not be configured\n"
52
53/*
54 * Default timeout
55 */
56#define SCSI_TIMEOUT (2*HZ)
57
58/*
59 * Prefix values for the SCSI id's (stored in sysfs name field)
60 */
61#define SCSI_UID_SER_NUM 'S'
62#define SCSI_UID_UNKNOWN 'Z'
63
64/*
65 * Return values of some of the scanning functions.
66 *
67 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
68 * includes allocation or general failures preventing IO from being sent.
69 *
70 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
71 * on the given LUN.
72 *
73 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
74 * given LUN.
75 */
76#define SCSI_SCAN_NO_RESPONSE 0
77#define SCSI_SCAN_TARGET_PRESENT 1
78#define SCSI_SCAN_LUN_PRESENT 2
79
80static const char *scsi_null_device_strs = "nullnullnullnull";
81
82#define MAX_SCSI_LUNS 512
83
84#ifdef CONFIG_SCSI_MULTI_LUN
85static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
86#else
87static unsigned int max_scsi_luns = 1;
88#endif
89
90module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR);
91MODULE_PARM_DESC(max_luns,
92 "last scsi LUN (should be between 1 and 2^32-1)");
93
94#ifdef CONFIG_SCSI_SCAN_ASYNC
95#define SCSI_SCAN_TYPE_DEFAULT "async"
96#else
97#define SCSI_SCAN_TYPE_DEFAULT "sync"
98#endif
99
100static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
101
102module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
103MODULE_PARM_DESC(scan, "sync, async or none");
104
105/*
106 * max_scsi_report_luns: the maximum number of LUNS that will be
107 * returned from the REPORT LUNS command. 8 times this value must
108 * be allocated. In theory this could be up to an 8 byte value, but
109 * in practice, the maximum number of LUNs suppored by any device
110 * is about 16k.
111 */
112static unsigned int max_scsi_report_luns = 511;
113
114module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
115MODULE_PARM_DESC(max_report_luns,
116 "REPORT LUNS maximum number of LUNS received (should be"
117 " between 1 and 16384)");
118
119static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ + 18;
120
121module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
122MODULE_PARM_DESC(inq_timeout,
123 "Timeout (in seconds) waiting for devices to answer INQUIRY."
124 " Default is 20. Some devices may need more; most need less.");
125
126/* This lock protects only this list */
127static DEFINE_SPINLOCK(async_scan_lock);
128static LIST_HEAD(scanning_hosts);
129
130struct async_scan_data {
131 struct list_head list;
132 struct Scsi_Host *shost;
133 struct completion prev_finished;
134};
135
136/**
137 * scsi_complete_async_scans - Wait for asynchronous scans to complete
138 *
139 * When this function returns, any host which started scanning before
140 * this function was called will have finished its scan. Hosts which
141 * started scanning after this function was called may or may not have
142 * finished.
143 */
144int scsi_complete_async_scans(void)
145{
146 struct async_scan_data *data;
147
148 do {
149 if (list_empty(&scanning_hosts))
150 return 0;
151 /* If we can't get memory immediately, that's OK. Just
152 * sleep a little. Even if we never get memory, the async
153 * scans will finish eventually.
154 */
155 data = kmalloc(sizeof(*data), GFP_KERNEL);
156 if (!data)
157 msleep(1);
158 } while (!data);
159
160 data->shost = NULL;
161 init_completion(&data->prev_finished);
162
163 spin_lock(&async_scan_lock);
164 /* Check that there's still somebody else on the list */
165 if (list_empty(&scanning_hosts))
166 goto done;
167 list_add_tail(&data->list, &scanning_hosts);
168 spin_unlock(&async_scan_lock);
169
170 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
171 wait_for_completion(&data->prev_finished);
172
173 spin_lock(&async_scan_lock);
174 list_del(&data->list);
175 if (!list_empty(&scanning_hosts)) {
176 struct async_scan_data *next = list_entry(scanning_hosts.next,
177 struct async_scan_data, list);
178 complete(&next->prev_finished);
179 }
180 done:
181 spin_unlock(&async_scan_lock);
182
183 kfree(data);
184 return 0;
185}
186
187/* Only exported for the benefit of scsi_wait_scan */
188EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
189
190#ifndef MODULE
191/*
192 * For async scanning we need to wait for all the scans to complete before
193 * trying to mount the root fs. Otherwise non-modular drivers may not be ready
194 * yet.
195 */
196late_initcall(scsi_complete_async_scans);
197#endif
198
199/**
200 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
201 * @sdev: scsi device to send command to
202 * @result: area to store the result of the MODE SENSE
203 *
204 * Description:
205 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
206 * Called for BLIST_KEY devices.
207 **/
208static void scsi_unlock_floptical(struct scsi_device *sdev,
209 unsigned char *result)
210{
211 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
212
213 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
214 scsi_cmd[0] = MODE_SENSE;
215 scsi_cmd[1] = 0;
216 scsi_cmd[2] = 0x2e;
217 scsi_cmd[3] = 0;
218 scsi_cmd[4] = 0x2a; /* size */
219 scsi_cmd[5] = 0;
220 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
221 SCSI_TIMEOUT, 3, NULL);
222}
223
224/**
225 * scsi_alloc_sdev - allocate and setup a scsi_Device
226 * @starget: which target to allocate a &scsi_device for
227 * @lun: which lun
228 * @hostdata: usually NULL and set by ->slave_alloc instead
229 *
230 * Description:
231 * Allocate, initialize for io, and return a pointer to a scsi_Device.
232 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
233 * adds scsi_Device to the appropriate list.
234 *
235 * Return value:
236 * scsi_Device pointer, or NULL on failure.
237 **/
238static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
239 unsigned int lun, void *hostdata)
240{
241 struct scsi_device *sdev;
242 int display_failure_msg = 1, ret;
243 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
244 extern void scsi_evt_thread(struct work_struct *work);
245 extern void scsi_requeue_run_queue(struct work_struct *work);
246
247 sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size,
248 GFP_ATOMIC);
249 if (!sdev)
250 goto out;
251
252 sdev->vendor = scsi_null_device_strs;
253 sdev->model = scsi_null_device_strs;
254 sdev->rev = scsi_null_device_strs;
255 sdev->host = shost;
256 sdev->queue_ramp_up_period = SCSI_DEFAULT_RAMP_UP_PERIOD;
257 sdev->id = starget->id;
258 sdev->lun = lun;
259 sdev->channel = starget->channel;
260 sdev->sdev_state = SDEV_CREATED;
261 INIT_LIST_HEAD(&sdev->siblings);
262 INIT_LIST_HEAD(&sdev->same_target_siblings);
263 INIT_LIST_HEAD(&sdev->cmd_list);
264 INIT_LIST_HEAD(&sdev->starved_entry);
265 INIT_LIST_HEAD(&sdev->event_list);
266 spin_lock_init(&sdev->list_lock);
267 INIT_WORK(&sdev->event_work, scsi_evt_thread);
268 INIT_WORK(&sdev->requeue_work, scsi_requeue_run_queue);
269
270 sdev->sdev_gendev.parent = get_device(&starget->dev);
271 sdev->sdev_target = starget;
272
273 /* usually NULL and set by ->slave_alloc instead */
274 sdev->hostdata = hostdata;
275
276 /* if the device needs this changing, it may do so in the
277 * slave_configure function */
278 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
279
280 /*
281 * Some low level driver could use device->type
282 */
283 sdev->type = -1;
284
285 /*
286 * Assume that the device will have handshaking problems,
287 * and then fix this field later if it turns out it
288 * doesn't
289 */
290 sdev->borken = 1;
291
292 sdev->request_queue = scsi_alloc_queue(sdev);
293 if (!sdev->request_queue) {
294 /* release fn is set up in scsi_sysfs_device_initialise, so
295 * have to free and put manually here */
296 put_device(&starget->dev);
297 kfree(sdev);
298 goto out;
299 }
300 blk_get_queue(sdev->request_queue);
301 sdev->request_queue->queuedata = sdev;
302 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
303
304 scsi_sysfs_device_initialize(sdev);
305
306 if (shost->hostt->slave_alloc) {
307 ret = shost->hostt->slave_alloc(sdev);
308 if (ret) {
309 /*
310 * if LLDD reports slave not present, don't clutter
311 * console with alloc failure messages
312 */
313 if (ret == -ENXIO)
314 display_failure_msg = 0;
315 goto out_device_destroy;
316 }
317 }
318
319 return sdev;
320
321out_device_destroy:
322 __scsi_remove_device(sdev);
323out:
324 if (display_failure_msg)
325 printk(ALLOC_FAILURE_MSG, __func__);
326 return NULL;
327}
328
329static void scsi_target_destroy(struct scsi_target *starget)
330{
331 struct device *dev = &starget->dev;
332 struct Scsi_Host *shost = dev_to_shost(dev->parent);
333 unsigned long flags;
334
335 transport_destroy_device(dev);
336 spin_lock_irqsave(shost->host_lock, flags);
337 if (shost->hostt->target_destroy)
338 shost->hostt->target_destroy(starget);
339 list_del_init(&starget->siblings);
340 spin_unlock_irqrestore(shost->host_lock, flags);
341 put_device(dev);
342}
343
344static void scsi_target_dev_release(struct device *dev)
345{
346 struct device *parent = dev->parent;
347 struct scsi_target *starget = to_scsi_target(dev);
348
349 kfree(starget);
350 put_device(parent);
351}
352
353static struct device_type scsi_target_type = {
354 .name = "scsi_target",
355 .release = scsi_target_dev_release,
356};
357
358int scsi_is_target_device(const struct device *dev)
359{
360 return dev->type == &scsi_target_type;
361}
362EXPORT_SYMBOL(scsi_is_target_device);
363
364static struct scsi_target *__scsi_find_target(struct device *parent,
365 int channel, uint id)
366{
367 struct scsi_target *starget, *found_starget = NULL;
368 struct Scsi_Host *shost = dev_to_shost(parent);
369 /*
370 * Search for an existing target for this sdev.
371 */
372 list_for_each_entry(starget, &shost->__targets, siblings) {
373 if (starget->id == id &&
374 starget->channel == channel) {
375 found_starget = starget;
376 break;
377 }
378 }
379 if (found_starget)
380 get_device(&found_starget->dev);
381
382 return found_starget;
383}
384
385/**
386 * scsi_alloc_target - allocate a new or find an existing target
387 * @parent: parent of the target (need not be a scsi host)
388 * @channel: target channel number (zero if no channels)
389 * @id: target id number
390 *
391 * Return an existing target if one exists, provided it hasn't already
392 * gone into STARGET_DEL state, otherwise allocate a new target.
393 *
394 * The target is returned with an incremented reference, so the caller
395 * is responsible for both reaping and doing a last put
396 */
397static struct scsi_target *scsi_alloc_target(struct device *parent,
398 int channel, uint id)
399{
400 struct Scsi_Host *shost = dev_to_shost(parent);
401 struct device *dev = NULL;
402 unsigned long flags;
403 const int size = sizeof(struct scsi_target)
404 + shost->transportt->target_size;
405 struct scsi_target *starget;
406 struct scsi_target *found_target;
407 int error;
408
409 starget = kzalloc(size, GFP_KERNEL);
410 if (!starget) {
411 printk(KERN_ERR "%s: allocation failure\n", __func__);
412 return NULL;
413 }
414 dev = &starget->dev;
415 device_initialize(dev);
416 starget->reap_ref = 1;
417 dev->parent = get_device(parent);
418 dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id);
419 dev->bus = &scsi_bus_type;
420 dev->type = &scsi_target_type;
421 starget->id = id;
422 starget->channel = channel;
423 starget->can_queue = 0;
424 INIT_LIST_HEAD(&starget->siblings);
425 INIT_LIST_HEAD(&starget->devices);
426 starget->state = STARGET_CREATED;
427 starget->scsi_level = SCSI_2;
428 starget->max_target_blocked = SCSI_DEFAULT_TARGET_BLOCKED;
429 retry:
430 spin_lock_irqsave(shost->host_lock, flags);
431
432 found_target = __scsi_find_target(parent, channel, id);
433 if (found_target)
434 goto found;
435
436 list_add_tail(&starget->siblings, &shost->__targets);
437 spin_unlock_irqrestore(shost->host_lock, flags);
438 /* allocate and add */
439 transport_setup_device(dev);
440 if (shost->hostt->target_alloc) {
441 error = shost->hostt->target_alloc(starget);
442
443 if(error) {
444 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
445 /* don't want scsi_target_reap to do the final
446 * put because it will be under the host lock */
447 scsi_target_destroy(starget);
448 return NULL;
449 }
450 }
451 get_device(dev);
452
453 return starget;
454
455 found:
456 found_target->reap_ref++;
457 spin_unlock_irqrestore(shost->host_lock, flags);
458 if (found_target->state != STARGET_DEL) {
459 put_device(dev);
460 return found_target;
461 }
462 /* Unfortunately, we found a dying target; need to
463 * wait until it's dead before we can get a new one */
464 put_device(&found_target->dev);
465 flush_scheduled_work();
466 goto retry;
467}
468
469static void scsi_target_reap_usercontext(struct work_struct *work)
470{
471 struct scsi_target *starget =
472 container_of(work, struct scsi_target, ew.work);
473
474 transport_remove_device(&starget->dev);
475 device_del(&starget->dev);
476 scsi_target_destroy(starget);
477}
478
479/**
480 * scsi_target_reap - check to see if target is in use and destroy if not
481 * @starget: target to be checked
482 *
483 * This is used after removing a LUN or doing a last put of the target
484 * it checks atomically that nothing is using the target and removes
485 * it if so.
486 */
487void scsi_target_reap(struct scsi_target *starget)
488{
489 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
490 unsigned long flags;
491 enum scsi_target_state state;
492 int empty = 0;
493
494 spin_lock_irqsave(shost->host_lock, flags);
495 state = starget->state;
496 if (--starget->reap_ref == 0 && list_empty(&starget->devices)) {
497 empty = 1;
498 starget->state = STARGET_DEL;
499 }
500 spin_unlock_irqrestore(shost->host_lock, flags);
501
502 if (!empty)
503 return;
504
505 BUG_ON(state == STARGET_DEL);
506 if (state == STARGET_CREATED)
507 scsi_target_destroy(starget);
508 else
509 execute_in_process_context(scsi_target_reap_usercontext,
510 &starget->ew);
511}
512
513/**
514 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string
515 * @s: INQUIRY result string to sanitize
516 * @len: length of the string
517 *
518 * Description:
519 * The SCSI spec says that INQUIRY vendor, product, and revision
520 * strings must consist entirely of graphic ASCII characters,
521 * padded on the right with spaces. Since not all devices obey
522 * this rule, we will replace non-graphic or non-ASCII characters
523 * with spaces. Exception: a NUL character is interpreted as a
524 * string terminator, so all the following characters are set to
525 * spaces.
526 **/
527static void sanitize_inquiry_string(unsigned char *s, int len)
528{
529 int terminated = 0;
530
531 for (; len > 0; (--len, ++s)) {
532 if (*s == 0)
533 terminated = 1;
534 if (terminated || *s < 0x20 || *s > 0x7e)
535 *s = ' ';
536 }
537}
538
539/**
540 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
541 * @sdev: scsi_device to probe
542 * @inq_result: area to store the INQUIRY result
543 * @result_len: len of inq_result
544 * @bflags: store any bflags found here
545 *
546 * Description:
547 * Probe the lun associated with @req using a standard SCSI INQUIRY;
548 *
549 * If the INQUIRY is successful, zero is returned and the
550 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
551 * are copied to the scsi_device any flags value is stored in *@bflags.
552 **/
553static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
554 int result_len, int *bflags)
555{
556 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
557 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
558 int response_len = 0;
559 int pass, count, result;
560 struct scsi_sense_hdr sshdr;
561
562 *bflags = 0;
563
564 /* Perform up to 3 passes. The first pass uses a conservative
565 * transfer length of 36 unless sdev->inquiry_len specifies a
566 * different value. */
567 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
568 try_inquiry_len = first_inquiry_len;
569 pass = 1;
570
571 next_pass:
572 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
573 "scsi scan: INQUIRY pass %d length %d\n",
574 pass, try_inquiry_len));
575
576 /* Each pass gets up to three chances to ignore Unit Attention */
577 for (count = 0; count < 3; ++count) {
578 int resid;
579
580 memset(scsi_cmd, 0, 6);
581 scsi_cmd[0] = INQUIRY;
582 scsi_cmd[4] = (unsigned char) try_inquiry_len;
583
584 memset(inq_result, 0, try_inquiry_len);
585
586 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
587 inq_result, try_inquiry_len, &sshdr,
588 HZ / 2 + HZ * scsi_inq_timeout, 3,
589 &resid);
590
591 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
592 "with code 0x%x\n",
593 result ? "failed" : "successful", result));
594
595 if (result) {
596 /*
597 * not-ready to ready transition [asc/ascq=0x28/0x0]
598 * or power-on, reset [asc/ascq=0x29/0x0], continue.
599 * INQUIRY should not yield UNIT_ATTENTION
600 * but many buggy devices do so anyway.
601 */
602 if ((driver_byte(result) & DRIVER_SENSE) &&
603 scsi_sense_valid(&sshdr)) {
604 if ((sshdr.sense_key == UNIT_ATTENTION) &&
605 ((sshdr.asc == 0x28) ||
606 (sshdr.asc == 0x29)) &&
607 (sshdr.ascq == 0))
608 continue;
609 }
610 } else {
611 /*
612 * if nothing was transferred, we try
613 * again. It's a workaround for some USB
614 * devices.
615 */
616 if (resid == try_inquiry_len)
617 continue;
618 }
619 break;
620 }
621
622 if (result == 0) {
623 sanitize_inquiry_string(&inq_result[8], 8);
624 sanitize_inquiry_string(&inq_result[16], 16);
625 sanitize_inquiry_string(&inq_result[32], 4);
626
627 response_len = inq_result[4] + 5;
628 if (response_len > 255)
629 response_len = first_inquiry_len; /* sanity */
630
631 /*
632 * Get any flags for this device.
633 *
634 * XXX add a bflags to scsi_device, and replace the
635 * corresponding bit fields in scsi_device, so bflags
636 * need not be passed as an argument.
637 */
638 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
639 &inq_result[16]);
640
641 /* When the first pass succeeds we gain information about
642 * what larger transfer lengths might work. */
643 if (pass == 1) {
644 if (BLIST_INQUIRY_36 & *bflags)
645 next_inquiry_len = 36;
646 else if (BLIST_INQUIRY_58 & *bflags)
647 next_inquiry_len = 58;
648 else if (sdev->inquiry_len)
649 next_inquiry_len = sdev->inquiry_len;
650 else
651 next_inquiry_len = response_len;
652
653 /* If more data is available perform the second pass */
654 if (next_inquiry_len > try_inquiry_len) {
655 try_inquiry_len = next_inquiry_len;
656 pass = 2;
657 goto next_pass;
658 }
659 }
660
661 } else if (pass == 2) {
662 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
663 "Consider BLIST_INQUIRY_36 for this device\n",
664 try_inquiry_len);
665
666 /* If this pass failed, the third pass goes back and transfers
667 * the same amount as we successfully got in the first pass. */
668 try_inquiry_len = first_inquiry_len;
669 pass = 3;
670 goto next_pass;
671 }
672
673 /* If the last transfer attempt got an error, assume the
674 * peripheral doesn't exist or is dead. */
675 if (result)
676 return -EIO;
677
678 /* Don't report any more data than the device says is valid */
679 sdev->inquiry_len = min(try_inquiry_len, response_len);
680
681 /*
682 * XXX Abort if the response length is less than 36? If less than
683 * 32, the lookup of the device flags (above) could be invalid,
684 * and it would be possible to take an incorrect action - we do
685 * not want to hang because of a short INQUIRY. On the flip side,
686 * if the device is spun down or becoming ready (and so it gives a
687 * short INQUIRY), an abort here prevents any further use of the
688 * device, including spin up.
689 *
690 * On the whole, the best approach seems to be to assume the first
691 * 36 bytes are valid no matter what the device says. That's
692 * better than copying < 36 bytes to the inquiry-result buffer
693 * and displaying garbage for the Vendor, Product, or Revision
694 * strings.
695 */
696 if (sdev->inquiry_len < 36) {
697 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
698 " using 36\n", sdev->inquiry_len);
699 sdev->inquiry_len = 36;
700 }
701
702 /*
703 * Related to the above issue:
704 *
705 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
706 * and if not ready, sent a START_STOP to start (maybe spin up) and
707 * then send the INQUIRY again, since the INQUIRY can change after
708 * a device is initialized.
709 *
710 * Ideally, start a device if explicitly asked to do so. This
711 * assumes that a device is spun up on power on, spun down on
712 * request, and then spun up on request.
713 */
714
715 /*
716 * The scanning code needs to know the scsi_level, even if no
717 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
718 * non-zero LUNs can be scanned.
719 */
720 sdev->scsi_level = inq_result[2] & 0x07;
721 if (sdev->scsi_level >= 2 ||
722 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
723 sdev->scsi_level++;
724 sdev->sdev_target->scsi_level = sdev->scsi_level;
725
726 return 0;
727}
728
729/**
730 * scsi_add_lun - allocate and fully initialze a scsi_device
731 * @sdev: holds information to be stored in the new scsi_device
732 * @inq_result: holds the result of a previous INQUIRY to the LUN
733 * @bflags: black/white list flag
734 * @async: 1 if this device is being scanned asynchronously
735 *
736 * Description:
737 * Initialize the scsi_device @sdev. Optionally set fields based
738 * on values in *@bflags.
739 *
740 * Return:
741 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
742 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
743 **/
744static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
745 int *bflags, int async)
746{
747 int ret;
748
749 /*
750 * XXX do not save the inquiry, since it can change underneath us,
751 * save just vendor/model/rev.
752 *
753 * Rather than save it and have an ioctl that retrieves the saved
754 * value, have an ioctl that executes the same INQUIRY code used
755 * in scsi_probe_lun, let user level programs doing INQUIRY
756 * scanning run at their own risk, or supply a user level program
757 * that can correctly scan.
758 */
759
760 /*
761 * Copy at least 36 bytes of INQUIRY data, so that we don't
762 * dereference unallocated memory when accessing the Vendor,
763 * Product, and Revision strings. Badly behaved devices may set
764 * the INQUIRY Additional Length byte to a small value, indicating
765 * these strings are invalid, but often they contain plausible data
766 * nonetheless. It doesn't matter if the device sent < 36 bytes
767 * total, since scsi_probe_lun() initializes inq_result with 0s.
768 */
769 sdev->inquiry = kmemdup(inq_result,
770 max_t(size_t, sdev->inquiry_len, 36),
771 GFP_ATOMIC);
772 if (sdev->inquiry == NULL)
773 return SCSI_SCAN_NO_RESPONSE;
774
775 sdev->vendor = (char *) (sdev->inquiry + 8);
776 sdev->model = (char *) (sdev->inquiry + 16);
777 sdev->rev = (char *) (sdev->inquiry + 32);
778
779 if (*bflags & BLIST_ISROM) {
780 sdev->type = TYPE_ROM;
781 sdev->removable = 1;
782 } else {
783 sdev->type = (inq_result[0] & 0x1f);
784 sdev->removable = (inq_result[1] & 0x80) >> 7;
785 }
786
787 switch (sdev->type) {
788 case TYPE_RBC:
789 case TYPE_TAPE:
790 case TYPE_DISK:
791 case TYPE_PRINTER:
792 case TYPE_MOD:
793 case TYPE_PROCESSOR:
794 case TYPE_SCANNER:
795 case TYPE_MEDIUM_CHANGER:
796 case TYPE_ENCLOSURE:
797 case TYPE_COMM:
798 case TYPE_RAID:
799 case TYPE_OSD:
800 sdev->writeable = 1;
801 break;
802 case TYPE_ROM:
803 case TYPE_WORM:
804 sdev->writeable = 0;
805 break;
806 default:
807 printk(KERN_INFO "scsi: unknown device type %d\n", sdev->type);
808 }
809
810 if (sdev->type == TYPE_RBC || sdev->type == TYPE_ROM) {
811 /* RBC and MMC devices can return SCSI-3 compliance and yet
812 * still not support REPORT LUNS, so make them act as
813 * BLIST_NOREPORTLUN unless BLIST_REPORTLUN2 is
814 * specifically set */
815 if ((*bflags & BLIST_REPORTLUN2) == 0)
816 *bflags |= BLIST_NOREPORTLUN;
817 }
818
819 /*
820 * For a peripheral qualifier (PQ) value of 1 (001b), the SCSI
821 * spec says: The device server is capable of supporting the
822 * specified peripheral device type on this logical unit. However,
823 * the physical device is not currently connected to this logical
824 * unit.
825 *
826 * The above is vague, as it implies that we could treat 001 and
827 * 011 the same. Stay compatible with previous code, and create a
828 * scsi_device for a PQ of 1
829 *
830 * Don't set the device offline here; rather let the upper
831 * level drivers eval the PQ to decide whether they should
832 * attach. So remove ((inq_result[0] >> 5) & 7) == 1 check.
833 */
834
835 sdev->inq_periph_qual = (inq_result[0] >> 5) & 7;
836 sdev->lockable = sdev->removable;
837 sdev->soft_reset = (inq_result[7] & 1) && ((inq_result[3] & 7) == 2);
838
839 if (sdev->scsi_level >= SCSI_3 ||
840 (sdev->inquiry_len > 56 && inq_result[56] & 0x04))
841 sdev->ppr = 1;
842 if (inq_result[7] & 0x60)
843 sdev->wdtr = 1;
844 if (inq_result[7] & 0x10)
845 sdev->sdtr = 1;
846
847 sdev_printk(KERN_NOTICE, sdev, "%s %.8s %.16s %.4s PQ: %d "
848 "ANSI: %d%s\n", scsi_device_type(sdev->type),
849 sdev->vendor, sdev->model, sdev->rev,
850 sdev->inq_periph_qual, inq_result[2] & 0x07,
851 (inq_result[3] & 0x0f) == 1 ? " CCS" : "");
852
853 if ((sdev->scsi_level >= SCSI_2) && (inq_result[7] & 2) &&
854 !(*bflags & BLIST_NOTQ))
855 sdev->tagged_supported = 1;
856
857 /*
858 * Some devices (Texel CD ROM drives) have handshaking problems
859 * when used with the Seagate controllers. borken is initialized
860 * to 1, and then set it to 0 here.
861 */
862 if ((*bflags & BLIST_BORKEN) == 0)
863 sdev->borken = 0;
864
865 if (*bflags & BLIST_NO_ULD_ATTACH)
866 sdev->no_uld_attach = 1;
867
868 /*
869 * Apparently some really broken devices (contrary to the SCSI
870 * standards) need to be selected without asserting ATN
871 */
872 if (*bflags & BLIST_SELECT_NO_ATN)
873 sdev->select_no_atn = 1;
874
875 /*
876 * Maximum 512 sector transfer length
877 * broken RA4x00 Compaq Disk Array
878 */
879 if (*bflags & BLIST_MAX_512)
880 blk_queue_max_hw_sectors(sdev->request_queue, 512);
881
882 /*
883 * Some devices may not want to have a start command automatically
884 * issued when a device is added.
885 */
886 if (*bflags & BLIST_NOSTARTONADD)
887 sdev->no_start_on_add = 1;
888
889 if (*bflags & BLIST_SINGLELUN)
890 scsi_target(sdev)->single_lun = 1;
891
892 sdev->use_10_for_rw = 1;
893
894 if (*bflags & BLIST_MS_SKIP_PAGE_08)
895 sdev->skip_ms_page_8 = 1;
896
897 if (*bflags & BLIST_MS_SKIP_PAGE_3F)
898 sdev->skip_ms_page_3f = 1;
899
900 if (*bflags & BLIST_USE_10_BYTE_MS)
901 sdev->use_10_for_ms = 1;
902
903 /* set the device running here so that slave configure
904 * may do I/O */
905 ret = scsi_device_set_state(sdev, SDEV_RUNNING);
906 if (ret) {
907 ret = scsi_device_set_state(sdev, SDEV_BLOCK);
908
909 if (ret) {
910 sdev_printk(KERN_ERR, sdev,
911 "in wrong state %s to complete scan\n",
912 scsi_device_state_name(sdev->sdev_state));
913 return SCSI_SCAN_NO_RESPONSE;
914 }
915 }
916
917 if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
918 sdev->use_192_bytes_for_3f = 1;
919
920 if (*bflags & BLIST_NOT_LOCKABLE)
921 sdev->lockable = 0;
922
923 if (*bflags & BLIST_RETRY_HWERROR)
924 sdev->retry_hwerror = 1;
925
926 transport_configure_device(&sdev->sdev_gendev);
927
928 if (sdev->host->hostt->slave_configure) {
929 ret = sdev->host->hostt->slave_configure(sdev);
930 if (ret) {
931 /*
932 * if LLDD reports slave not present, don't clutter
933 * console with alloc failure messages
934 */
935 if (ret != -ENXIO) {
936 sdev_printk(KERN_ERR, sdev,
937 "failed to configure device\n");
938 }
939 return SCSI_SCAN_NO_RESPONSE;
940 }
941 }
942
943 sdev->max_queue_depth = sdev->queue_depth;
944
945 /*
946 * Ok, the device is now all set up, we can
947 * register it and tell the rest of the kernel
948 * about it.
949 */
950 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
951 return SCSI_SCAN_NO_RESPONSE;
952
953 return SCSI_SCAN_LUN_PRESENT;
954}
955
956#ifdef CONFIG_SCSI_LOGGING
957/**
958 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
959 * @buf: Output buffer with at least end-first+1 bytes of space
960 * @inq: Inquiry buffer (input)
961 * @first: Offset of string into inq
962 * @end: Index after last character in inq
963 */
964static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
965 unsigned first, unsigned end)
966{
967 unsigned term = 0, idx;
968
969 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
970 if (inq[idx+first] > ' ') {
971 buf[idx] = inq[idx+first];
972 term = idx+1;
973 } else {
974 buf[idx] = ' ';
975 }
976 }
977 buf[term] = 0;
978 return buf;
979}
980#endif
981
982/**
983 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
984 * @starget: pointer to target device structure
985 * @lun: LUN of target device
986 * @bflagsp: store bflags here if not NULL
987 * @sdevp: probe the LUN corresponding to this scsi_device
988 * @rescan: if nonzero skip some code only needed on first scan
989 * @hostdata: passed to scsi_alloc_sdev()
990 *
991 * Description:
992 * Call scsi_probe_lun, if a LUN with an attached device is found,
993 * allocate and set it up by calling scsi_add_lun.
994 *
995 * Return:
996 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
997 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
998 * attached at the LUN
999 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1000 **/
1001static int scsi_probe_and_add_lun(struct scsi_target *starget,
1002 uint lun, int *bflagsp,
1003 struct scsi_device **sdevp, int rescan,
1004 void *hostdata)
1005{
1006 struct scsi_device *sdev;
1007 unsigned char *result;
1008 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1009 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1010
1011 /*
1012 * The rescan flag is used as an optimization, the first scan of a
1013 * host adapter calls into here with rescan == 0.
1014 */
1015 sdev = scsi_device_lookup_by_target(starget, lun);
1016 if (sdev) {
1017 if (rescan || !scsi_device_created(sdev)) {
1018 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1019 "scsi scan: device exists on %s\n",
1020 dev_name(&sdev->sdev_gendev)));
1021 if (sdevp)
1022 *sdevp = sdev;
1023 else
1024 scsi_device_put(sdev);
1025
1026 if (bflagsp)
1027 *bflagsp = scsi_get_device_flags(sdev,
1028 sdev->vendor,
1029 sdev->model);
1030 return SCSI_SCAN_LUN_PRESENT;
1031 }
1032 scsi_device_put(sdev);
1033 } else
1034 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1035 if (!sdev)
1036 goto out;
1037
1038 result = kmalloc(result_len, GFP_ATOMIC |
1039 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1040 if (!result)
1041 goto out_free_sdev;
1042
1043 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1044 goto out_free_result;
1045
1046 if (bflagsp)
1047 *bflagsp = bflags;
1048 /*
1049 * result contains valid SCSI INQUIRY data.
1050 */
1051 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
1052 /*
1053 * For a Peripheral qualifier 3 (011b), the SCSI
1054 * spec says: The device server is not capable of
1055 * supporting a physical device on this logical
1056 * unit.
1057 *
1058 * For disks, this implies that there is no
1059 * logical disk configured at sdev->lun, but there
1060 * is a target id responding.
1061 */
1062 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1063 " peripheral qualifier of 3, device not"
1064 " added\n"))
1065 if (lun == 0) {
1066 SCSI_LOG_SCAN_BUS(1, {
1067 unsigned char vend[9];
1068 unsigned char mod[17];
1069
1070 sdev_printk(KERN_INFO, sdev,
1071 "scsi scan: consider passing scsi_mod."
1072 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1073 scsi_inq_str(vend, result, 8, 16),
1074 scsi_inq_str(mod, result, 16, 32));
1075 });
1076
1077 }
1078
1079 res = SCSI_SCAN_TARGET_PRESENT;
1080 goto out_free_result;
1081 }
1082
1083 /*
1084 * Some targets may set slight variations of PQ and PDT to signal
1085 * that no LUN is present, so don't add sdev in these cases.
1086 * Two specific examples are:
1087 * 1) NetApp targets: return PQ=1, PDT=0x1f
1088 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1089 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1090 *
1091 * References:
1092 * 1) SCSI SPC-3, pp. 145-146
1093 * PQ=1: "A peripheral device having the specified peripheral
1094 * device type is not connected to this logical unit. However, the
1095 * device server is capable of supporting the specified peripheral
1096 * device type on this logical unit."
1097 * PDT=0x1f: "Unknown or no device type"
1098 * 2) USB UFI 1.0, p. 20
1099 * PDT=00h Direct-access device (floppy)
1100 * PDT=1Fh none (no FDD connected to the requested logical unit)
1101 */
1102 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1103 (result[0] & 0x1f) == 0x1f &&
1104 !scsi_is_wlun(lun)) {
1105 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1106 "scsi scan: peripheral device type"
1107 " of 31, no device added\n"));
1108 res = SCSI_SCAN_TARGET_PRESENT;
1109 goto out_free_result;
1110 }
1111
1112 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1113 if (res == SCSI_SCAN_LUN_PRESENT) {
1114 if (bflags & BLIST_KEY) {
1115 sdev->lockable = 0;
1116 scsi_unlock_floptical(sdev, result);
1117 }
1118 }
1119
1120 out_free_result:
1121 kfree(result);
1122 out_free_sdev:
1123 if (res == SCSI_SCAN_LUN_PRESENT) {
1124 if (sdevp) {
1125 if (scsi_device_get(sdev) == 0) {
1126 *sdevp = sdev;
1127 } else {
1128 __scsi_remove_device(sdev);
1129 res = SCSI_SCAN_NO_RESPONSE;
1130 }
1131 }
1132 } else
1133 __scsi_remove_device(sdev);
1134 out:
1135 return res;
1136}
1137
1138/**
1139 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1140 * @starget: pointer to target structure to scan
1141 * @bflags: black/white list flag for LUN 0
1142 * @scsi_level: Which version of the standard does this device adhere to
1143 * @rescan: passed to scsi_probe_add_lun()
1144 *
1145 * Description:
1146 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1147 * scanned) to some maximum lun until a LUN is found with no device
1148 * attached. Use the bflags to figure out any oddities.
1149 *
1150 * Modifies sdevscan->lun.
1151 **/
1152static void scsi_sequential_lun_scan(struct scsi_target *starget,
1153 int bflags, int scsi_level, int rescan)
1154{
1155 unsigned int sparse_lun, lun, max_dev_lun;
1156 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1157
1158 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
1159 "%s\n", dev_name(&starget->dev)));
1160
1161 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1162 /*
1163 * If this device is known to support sparse multiple units,
1164 * override the other settings, and scan all of them. Normally,
1165 * SCSI-3 devices should be scanned via the REPORT LUNS.
1166 */
1167 if (bflags & BLIST_SPARSELUN) {
1168 max_dev_lun = shost->max_lun;
1169 sparse_lun = 1;
1170 } else
1171 sparse_lun = 0;
1172
1173 /*
1174 * If less than SCSI_1_CSS, and no special lun scaning, stop
1175 * scanning; this matches 2.4 behaviour, but could just be a bug
1176 * (to continue scanning a SCSI_1_CSS device).
1177 *
1178 * This test is broken. We might not have any device on lun0 for
1179 * a sparselun device, and if that's the case then how would we
1180 * know the real scsi_level, eh? It might make sense to just not
1181 * scan any SCSI_1 device for non-0 luns, but that check would best
1182 * go into scsi_alloc_sdev() and just have it return null when asked
1183 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1184 *
1185 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1186 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1187 == 0))
1188 return;
1189 */
1190 /*
1191 * If this device is known to support multiple units, override
1192 * the other settings, and scan all of them.
1193 */
1194 if (bflags & BLIST_FORCELUN)
1195 max_dev_lun = shost->max_lun;
1196 /*
1197 * REGAL CDC-4X: avoid hang after LUN 4
1198 */
1199 if (bflags & BLIST_MAX5LUN)
1200 max_dev_lun = min(5U, max_dev_lun);
1201 /*
1202 * Do not scan SCSI-2 or lower device past LUN 7, unless
1203 * BLIST_LARGELUN.
1204 */
1205 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1206 max_dev_lun = min(8U, max_dev_lun);
1207
1208 /*
1209 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1210 * until we reach the max, or no LUN is found and we are not
1211 * sparse_lun.
1212 */
1213 for (lun = 1; lun < max_dev_lun; ++lun)
1214 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1215 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1216 !sparse_lun)
1217 return;
1218}
1219
1220/**
1221 * scsilun_to_int - convert a scsi_lun to an int
1222 * @scsilun: struct scsi_lun to be converted.
1223 *
1224 * Description:
1225 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1226 * integer, and return the result. The caller must check for
1227 * truncation before using this function.
1228 *
1229 * Notes:
1230 * The struct scsi_lun is assumed to be four levels, with each level
1231 * effectively containing a SCSI byte-ordered (big endian) short; the
1232 * addressing bits of each level are ignored (the highest two bits).
1233 * For a description of the LUN format, post SCSI-3 see the SCSI
1234 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1235 *
1236 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1237 * the integer: 0x0b030a04
1238 **/
1239int scsilun_to_int(struct scsi_lun *scsilun)
1240{
1241 int i;
1242 unsigned int lun;
1243
1244 lun = 0;
1245 for (i = 0; i < sizeof(lun); i += 2)
1246 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1247 scsilun->scsi_lun[i + 1]) << (i * 8));
1248 return lun;
1249}
1250EXPORT_SYMBOL(scsilun_to_int);
1251
1252/**
1253 * int_to_scsilun - reverts an int into a scsi_lun
1254 * @lun: integer to be reverted
1255 * @scsilun: struct scsi_lun to be set.
1256 *
1257 * Description:
1258 * Reverts the functionality of the scsilun_to_int, which packed
1259 * an 8-byte lun value into an int. This routine unpacks the int
1260 * back into the lun value.
1261 * Note: the scsilun_to_int() routine does not truly handle all
1262 * 8bytes of the lun value. This functions restores only as much
1263 * as was set by the routine.
1264 *
1265 * Notes:
1266 * Given an integer : 0x0b030a04, this function returns a
1267 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1268 *
1269 **/
1270void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1271{
1272 int i;
1273
1274 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1275
1276 for (i = 0; i < sizeof(lun); i += 2) {
1277 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1278 scsilun->scsi_lun[i+1] = lun & 0xFF;
1279 lun = lun >> 16;
1280 }
1281}
1282EXPORT_SYMBOL(int_to_scsilun);
1283
1284/**
1285 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1286 * @starget: which target
1287 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1288 * @rescan: nonzero if we can skip code only needed on first scan
1289 *
1290 * Description:
1291 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1292 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1293 *
1294 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1295 * LUNs even if it's older than SCSI-3.
1296 * If BLIST_NOREPORTLUN is set, return 1 always.
1297 * If BLIST_NOLUN is set, return 0 always.
1298 *
1299 * Return:
1300 * 0: scan completed (or no memory, so further scanning is futile)
1301 * 1: could not scan with REPORT LUN
1302 **/
1303static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1304 int rescan)
1305{
1306 char devname[64];
1307 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1308 unsigned int length;
1309 unsigned int lun;
1310 unsigned int num_luns;
1311 unsigned int retries;
1312 int result;
1313 struct scsi_lun *lunp, *lun_data;
1314 u8 *data;
1315 struct scsi_sense_hdr sshdr;
1316 struct scsi_device *sdev;
1317 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1318 int ret = 0;
1319
1320 /*
1321 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1322 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1323 * support more than 8 LUNs.
1324 */
1325 if (bflags & BLIST_NOREPORTLUN)
1326 return 1;
1327 if (starget->scsi_level < SCSI_2 &&
1328 starget->scsi_level != SCSI_UNKNOWN)
1329 return 1;
1330 if (starget->scsi_level < SCSI_3 &&
1331 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1332 return 1;
1333 if (bflags & BLIST_NOLUN)
1334 return 0;
1335
1336 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1337 sdev = scsi_alloc_sdev(starget, 0, NULL);
1338 if (!sdev)
1339 return 0;
1340 if (scsi_device_get(sdev)) {
1341 __scsi_remove_device(sdev);
1342 return 0;
1343 }
1344 }
1345
1346 sprintf(devname, "host %d channel %d id %d",
1347 shost->host_no, sdev->channel, sdev->id);
1348
1349 /*
1350 * Allocate enough to hold the header (the same size as one scsi_lun)
1351 * plus the max number of luns we are requesting.
1352 *
1353 * Reallocating and trying again (with the exact amount we need)
1354 * would be nice, but then we need to somehow limit the size
1355 * allocated based on the available memory and the limits of
1356 * kmalloc - we don't want a kmalloc() failure of a huge value to
1357 * prevent us from finding any LUNs on this target.
1358 */
1359 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1360 lun_data = kmalloc(length, GFP_ATOMIC |
1361 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1362 if (!lun_data) {
1363 printk(ALLOC_FAILURE_MSG, __func__);
1364 goto out;
1365 }
1366
1367 scsi_cmd[0] = REPORT_LUNS;
1368
1369 /*
1370 * bytes 1 - 5: reserved, set to zero.
1371 */
1372 memset(&scsi_cmd[1], 0, 5);
1373
1374 /*
1375 * bytes 6 - 9: length of the command.
1376 */
1377 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1378 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1379 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1380 scsi_cmd[9] = (unsigned char) length & 0xff;
1381
1382 scsi_cmd[10] = 0; /* reserved */
1383 scsi_cmd[11] = 0; /* control */
1384
1385 /*
1386 * We can get a UNIT ATTENTION, for example a power on/reset, so
1387 * retry a few times (like sd.c does for TEST UNIT READY).
1388 * Experience shows some combinations of adapter/devices get at
1389 * least two power on/resets.
1390 *
1391 * Illegal requests (for devices that do not support REPORT LUNS)
1392 * should come through as a check condition, and will not generate
1393 * a retry.
1394 */
1395 for (retries = 0; retries < 3; retries++) {
1396 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1397 " REPORT LUNS to %s (try %d)\n", devname,
1398 retries));
1399
1400 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1401 lun_data, length, &sshdr,
1402 SCSI_TIMEOUT + 4 * HZ, 3, NULL);
1403
1404 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1405 " %s (try %d) result 0x%x\n", result
1406 ? "failed" : "successful", retries, result));
1407 if (result == 0)
1408 break;
1409 else if (scsi_sense_valid(&sshdr)) {
1410 if (sshdr.sense_key != UNIT_ATTENTION)
1411 break;
1412 }
1413 }
1414
1415 if (result) {
1416 /*
1417 * The device probably does not support a REPORT LUN command
1418 */
1419 ret = 1;
1420 goto out_err;
1421 }
1422
1423 /*
1424 * Get the length from the first four bytes of lun_data.
1425 */
1426 data = (u8 *) lun_data->scsi_lun;
1427 length = ((data[0] << 24) | (data[1] << 16) |
1428 (data[2] << 8) | (data[3] << 0));
1429
1430 num_luns = (length / sizeof(struct scsi_lun));
1431 if (num_luns > max_scsi_report_luns) {
1432 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1433 " of %d luns reported, try increasing"
1434 " max_scsi_report_luns.\n", devname,
1435 max_scsi_report_luns, num_luns);
1436 num_luns = max_scsi_report_luns;
1437 }
1438
1439 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1440 "scsi scan: REPORT LUN scan\n"));
1441
1442 /*
1443 * Scan the luns in lun_data. The entry at offset 0 is really
1444 * the header, so start at 1 and go up to and including num_luns.
1445 */
1446 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1447 lun = scsilun_to_int(lunp);
1448
1449 /*
1450 * Check if the unused part of lunp is non-zero, and so
1451 * does not fit in lun.
1452 */
1453 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1454 int i;
1455
1456 /*
1457 * Output an error displaying the LUN in byte order,
1458 * this differs from what linux would print for the
1459 * integer LUN value.
1460 */
1461 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1462 data = (char *)lunp->scsi_lun;
1463 for (i = 0; i < sizeof(struct scsi_lun); i++)
1464 printk("%02x", data[i]);
1465 printk(" has a LUN larger than currently supported.\n");
1466 } else if (lun > sdev->host->max_lun) {
1467 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1468 " than allowed by the host adapter\n",
1469 devname, lun);
1470 } else {
1471 int res;
1472
1473 res = scsi_probe_and_add_lun(starget,
1474 lun, NULL, NULL, rescan, NULL);
1475 if (res == SCSI_SCAN_NO_RESPONSE) {
1476 /*
1477 * Got some results, but now none, abort.
1478 */
1479 sdev_printk(KERN_ERR, sdev,
1480 "Unexpected response"
1481 " from lun %d while scanning, scan"
1482 " aborted\n", lun);
1483 break;
1484 }
1485 }
1486 }
1487
1488 out_err:
1489 kfree(lun_data);
1490 out:
1491 scsi_device_put(sdev);
1492 if (scsi_device_created(sdev))
1493 /*
1494 * the sdev we used didn't appear in the report luns scan
1495 */
1496 __scsi_remove_device(sdev);
1497 return ret;
1498}
1499
1500struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1501 uint id, uint lun, void *hostdata)
1502{
1503 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1504 struct device *parent = &shost->shost_gendev;
1505 struct scsi_target *starget;
1506
1507 if (strncmp(scsi_scan_type, "none", 4) == 0)
1508 return ERR_PTR(-ENODEV);
1509
1510 starget = scsi_alloc_target(parent, channel, id);
1511 if (!starget)
1512 return ERR_PTR(-ENOMEM);
1513 scsi_autopm_get_target(starget);
1514
1515 mutex_lock(&shost->scan_mutex);
1516 if (!shost->async_scan)
1517 scsi_complete_async_scans();
1518
1519 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1520 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1521 scsi_autopm_put_host(shost);
1522 }
1523 mutex_unlock(&shost->scan_mutex);
1524 scsi_autopm_put_target(starget);
1525 scsi_target_reap(starget);
1526 put_device(&starget->dev);
1527
1528 return sdev;
1529}
1530EXPORT_SYMBOL(__scsi_add_device);
1531
1532int scsi_add_device(struct Scsi_Host *host, uint channel,
1533 uint target, uint lun)
1534{
1535 struct scsi_device *sdev =
1536 __scsi_add_device(host, channel, target, lun, NULL);
1537 if (IS_ERR(sdev))
1538 return PTR_ERR(sdev);
1539
1540 scsi_device_put(sdev);
1541 return 0;
1542}
1543EXPORT_SYMBOL(scsi_add_device);
1544
1545void scsi_rescan_device(struct device *dev)
1546{
1547 struct scsi_driver *drv;
1548
1549 if (!dev->driver)
1550 return;
1551
1552 drv = to_scsi_driver(dev->driver);
1553 if (try_module_get(drv->owner)) {
1554 if (drv->rescan)
1555 drv->rescan(dev);
1556 module_put(drv->owner);
1557 }
1558}
1559EXPORT_SYMBOL(scsi_rescan_device);
1560
1561static void __scsi_scan_target(struct device *parent, unsigned int channel,
1562 unsigned int id, unsigned int lun, int rescan)
1563{
1564 struct Scsi_Host *shost = dev_to_shost(parent);
1565 int bflags = 0;
1566 int res;
1567 struct scsi_target *starget;
1568
1569 if (shost->this_id == id)
1570 /*
1571 * Don't scan the host adapter
1572 */
1573 return;
1574
1575 starget = scsi_alloc_target(parent, channel, id);
1576 if (!starget)
1577 return;
1578 scsi_autopm_get_target(starget);
1579
1580 if (lun != SCAN_WILD_CARD) {
1581 /*
1582 * Scan for a specific host/chan/id/lun.
1583 */
1584 scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan, NULL);
1585 goto out_reap;
1586 }
1587
1588 /*
1589 * Scan LUN 0, if there is some response, scan further. Ideally, we
1590 * would not configure LUN 0 until all LUNs are scanned.
1591 */
1592 res = scsi_probe_and_add_lun(starget, 0, &bflags, NULL, rescan, NULL);
1593 if (res == SCSI_SCAN_LUN_PRESENT || res == SCSI_SCAN_TARGET_PRESENT) {
1594 if (scsi_report_lun_scan(starget, bflags, rescan) != 0)
1595 /*
1596 * The REPORT LUN did not scan the target,
1597 * do a sequential scan.
1598 */
1599 scsi_sequential_lun_scan(starget, bflags,
1600 starget->scsi_level, rescan);
1601 }
1602
1603 out_reap:
1604 scsi_autopm_put_target(starget);
1605 /* now determine if the target has any children at all
1606 * and if not, nuke it */
1607 scsi_target_reap(starget);
1608
1609 put_device(&starget->dev);
1610}
1611
1612/**
1613 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1614 * @parent: host to scan
1615 * @channel: channel to scan
1616 * @id: target id to scan
1617 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1618 * @rescan: passed to LUN scanning routines
1619 *
1620 * Description:
1621 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1622 * and possibly all LUNs on the target id.
1623 *
1624 * First try a REPORT LUN scan, if that does not scan the target, do a
1625 * sequential scan of LUNs on the target id.
1626 **/
1627void scsi_scan_target(struct device *parent, unsigned int channel,
1628 unsigned int id, unsigned int lun, int rescan)
1629{
1630 struct Scsi_Host *shost = dev_to_shost(parent);
1631
1632 if (strncmp(scsi_scan_type, "none", 4) == 0)
1633 return;
1634
1635 mutex_lock(&shost->scan_mutex);
1636 if (!shost->async_scan)
1637 scsi_complete_async_scans();
1638
1639 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1640 __scsi_scan_target(parent, channel, id, lun, rescan);
1641 scsi_autopm_put_host(shost);
1642 }
1643 mutex_unlock(&shost->scan_mutex);
1644}
1645EXPORT_SYMBOL(scsi_scan_target);
1646
1647static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1648 unsigned int id, unsigned int lun, int rescan)
1649{
1650 uint order_id;
1651
1652 if (id == SCAN_WILD_CARD)
1653 for (id = 0; id < shost->max_id; ++id) {
1654 /*
1655 * XXX adapter drivers when possible (FCP, iSCSI)
1656 * could modify max_id to match the current max,
1657 * not the absolute max.
1658 *
1659 * XXX add a shost id iterator, so for example,
1660 * the FC ID can be the same as a target id
1661 * without a huge overhead of sparse id's.
1662 */
1663 if (shost->reverse_ordering)
1664 /*
1665 * Scan from high to low id.
1666 */
1667 order_id = shost->max_id - id - 1;
1668 else
1669 order_id = id;
1670 __scsi_scan_target(&shost->shost_gendev, channel,
1671 order_id, lun, rescan);
1672 }
1673 else
1674 __scsi_scan_target(&shost->shost_gendev, channel,
1675 id, lun, rescan);
1676}
1677
1678int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1679 unsigned int id, unsigned int lun, int rescan)
1680{
1681 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1682 "%s: <%u:%u:%u>\n",
1683 __func__, channel, id, lun));
1684
1685 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1686 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1687 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1688 return -EINVAL;
1689
1690 mutex_lock(&shost->scan_mutex);
1691 if (!shost->async_scan)
1692 scsi_complete_async_scans();
1693
1694 if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) {
1695 if (channel == SCAN_WILD_CARD)
1696 for (channel = 0; channel <= shost->max_channel;
1697 channel++)
1698 scsi_scan_channel(shost, channel, id, lun,
1699 rescan);
1700 else
1701 scsi_scan_channel(shost, channel, id, lun, rescan);
1702 scsi_autopm_put_host(shost);
1703 }
1704 mutex_unlock(&shost->scan_mutex);
1705
1706 return 0;
1707}
1708
1709static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1710{
1711 struct scsi_device *sdev;
1712 shost_for_each_device(sdev, shost) {
1713 if (!scsi_host_scan_allowed(shost) ||
1714 scsi_sysfs_add_sdev(sdev) != 0)
1715 __scsi_remove_device(sdev);
1716 }
1717}
1718
1719/**
1720 * scsi_prep_async_sc…
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