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
37 #include <scsi/scsi.h>
38 #include <scsi/scsi_cmnd.h>
39 #include <scsi/scsi_device.h>
40 #include <scsi/scsi_driver.h>
41 #include <scsi/scsi_devinfo.h>
42 #include <scsi/scsi_host.h>
43 #include <scsi/scsi_transport.h>
44 #include <scsi/scsi_eh.h>
45
46 #include "scsi_priv.h"
47 #include "scsi_logging.h"
48
49 #define ALLOC_FAILURE_MSG KERN_ERR "%s: Allocation failure during" \
50 " SCSI scanning, some SCSI devices might not be configured\n"
51
52 /*
53 * Default timeout
54 */
55 #define SCSI_TIMEOUT (2*HZ)
56
57 /*
58 * Prefix values for the SCSI id's (stored in sysfs name field)
59 */
60 #define SCSI_UID_SER_NUM 'S'
61 #define SCSI_UID_UNKNOWN 'Z'
62
63 /*
64 * Return values of some of the scanning functions.
65 *
66 * SCSI_SCAN_NO_RESPONSE: no valid response received from the target, this
67 * includes allocation or general failures preventing IO from being sent.
68 *
69 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is available
70 * on the given LUN.
71 *
72 * SCSI_SCAN_LUN_PRESENT: target responded, and a device is available on a
73 * given LUN.
74 */
75 #define SCSI_SCAN_NO_RESPONSE 0
76 #define SCSI_SCAN_TARGET_PRESENT 1
77 #define SCSI_SCAN_LUN_PRESENT 2
78
79 static const char *scsi_null_device_strs = "nullnullnullnull";
80
81 #define MAX_SCSI_LUNS 512
82
83 #ifdef CONFIG_SCSI_MULTI_LUN
84 static unsigned int max_scsi_luns = MAX_SCSI_LUNS;
85 #else
86 static unsigned int max_scsi_luns = 1;
87 #endif
88
89 module_param_named(max_luns, max_scsi_luns, uint, S_IRUGO|S_IWUSR);
90 MODULE_PARM_DESC(max_luns,
91 "last scsi LUN (should be between 1 and 2^32-1)");
92
93 #ifdef CONFIG_SCSI_SCAN_ASYNC
94 #define SCSI_SCAN_TYPE_DEFAULT "async"
95 #else
96 #define SCSI_SCAN_TYPE_DEFAULT "sync"
97 #endif
98
99 static char scsi_scan_type[6] = SCSI_SCAN_TYPE_DEFAULT;
100
101 module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO);
102 MODULE_PARM_DESC(scan, "sync, async or none");
103
104 /*
105 * max_scsi_report_luns: the maximum number of LUNS that will be
106 * returned from the REPORT LUNS command. 8 times this value must
107 * be allocated. In theory this could be up to an 8 byte value, but
108 * in practice, the maximum number of LUNs suppored by any device
109 * is about 16k.
110 */
111 static unsigned int max_scsi_report_luns = 511;
112
113 module_param_named(max_report_luns, max_scsi_report_luns, uint, S_IRUGO|S_IWUSR);
114 MODULE_PARM_DESC(max_report_luns,
115 "REPORT LUNS maximum number of LUNS received (should be"
116 " between 1 and 16384)");
117
118 static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+3;
119
120 module_param_named(inq_timeout, scsi_inq_timeout, uint, S_IRUGO|S_IWUSR);
121 MODULE_PARM_DESC(inq_timeout,
122 "Timeout (in seconds) waiting for devices to answer INQUIRY."
123 " Default is 5. Some non-compliant devices need more.");
124
125 /* This lock protects only this list */
126 static DEFINE_SPINLOCK(async_scan_lock);
127 static LIST_HEAD(scanning_hosts);
128
129 struct async_scan_data {
130 struct list_head list;
131 struct Scsi_Host *shost;
132 struct completion prev_finished;
133 };
134
135 /**
136 * scsi_complete_async_scans - Wait for asynchronous scans to complete
137 *
138 * When this function returns, any host which started scanning before
139 * this function was called will have finished its scan. Hosts which
140 * started scanning after this function was called may or may not have
141 * finished.
142 */
scsi_complete_async_scans(void)143 int scsi_complete_async_scans(void)
144 {
145 struct async_scan_data *data;
146
147 do {
148 if (list_empty(&scanning_hosts))
149 return 0;
150 /* If we can't get memory immediately, that's OK. Just
151 * sleep a little. Even if we never get memory, the async
152 * scans will finish eventually.
153 */
154 data = kmalloc(sizeof(*data), GFP_KERNEL);
155 if (!data)
156 msleep(1);
157 } while (!data);
158
159 data->shost = NULL;
160 init_completion(&data->prev_finished);
161
162 spin_lock(&async_scan_lock);
163 /* Check that there's still somebody else on the list */
164 if (list_empty(&scanning_hosts))
165 goto done;
166 list_add_tail(&data->list, &scanning_hosts);
167 spin_unlock(&async_scan_lock);
168
169 printk(KERN_INFO "scsi: waiting for bus probes to complete ...\n");
170 wait_for_completion(&data->prev_finished);
171
172 spin_lock(&async_scan_lock);
173 list_del(&data->list);
174 if (!list_empty(&scanning_hosts)) {
175 struct async_scan_data *next = list_entry(scanning_hosts.next,
176 struct async_scan_data, list);
177 complete(&next->prev_finished);
178 }
179 done:
180 spin_unlock(&async_scan_lock);
181
182 kfree(data);
183 /* Synchronize async operations globally */
184 async_synchronize_full();
185 return 0;
186 }
187
188 /* Only exported for the benefit of scsi_wait_scan */
189 EXPORT_SYMBOL_GPL(scsi_complete_async_scans);
190
191 #ifndef MODULE
192 /*
193 * For async scanning we need to wait for all the scans to complete before
194 * trying to mount the root fs. Otherwise non-modular drivers may not be ready
195 * yet.
196 */
197 late_initcall(scsi_complete_async_scans);
198 #endif
199
200 /**
201 * scsi_unlock_floptical - unlock device via a special MODE SENSE command
202 * @sdev: scsi device to send command to
203 * @result: area to store the result of the MODE SENSE
204 *
205 * Description:
206 * Send a vendor specific MODE SENSE (not a MODE SELECT) command.
207 * Called for BLIST_KEY devices.
208 **/
scsi_unlock_floptical(struct scsi_device * sdev,unsigned char * result)209 static void scsi_unlock_floptical(struct scsi_device *sdev,
210 unsigned char *result)
211 {
212 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
213
214 printk(KERN_NOTICE "scsi: unlocking floptical drive\n");
215 scsi_cmd[0] = MODE_SENSE;
216 scsi_cmd[1] = 0;
217 scsi_cmd[2] = 0x2e;
218 scsi_cmd[3] = 0;
219 scsi_cmd[4] = 0x2a; /* size */
220 scsi_cmd[5] = 0;
221 scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
222 SCSI_TIMEOUT, 3, NULL);
223 }
224
225 /**
226 * scsi_alloc_sdev - allocate and setup a scsi_Device
227 * @starget: which target to allocate a &scsi_device for
228 * @lun: which lun
229 * @hostdata: usually NULL and set by ->slave_alloc instead
230 *
231 * Description:
232 * Allocate, initialize for io, and return a pointer to a scsi_Device.
233 * Stores the @shost, @channel, @id, and @lun in the scsi_Device, and
234 * adds scsi_Device to the appropriate list.
235 *
236 * Return value:
237 * scsi_Device pointer, or NULL on failure.
238 **/
scsi_alloc_sdev(struct scsi_target * starget,unsigned int lun,void * hostdata)239 static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
240 unsigned int lun, void *hostdata)
241 {
242 struct scsi_device *sdev;
243 int display_failure_msg = 1, ret;
244 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
245 extern void scsi_evt_thread(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->id = starget->id;
257 sdev->lun = lun;
258 sdev->channel = starget->channel;
259 sdev->sdev_state = SDEV_CREATED;
260 INIT_LIST_HEAD(&sdev->siblings);
261 INIT_LIST_HEAD(&sdev->same_target_siblings);
262 INIT_LIST_HEAD(&sdev->cmd_list);
263 INIT_LIST_HEAD(&sdev->starved_entry);
264 INIT_LIST_HEAD(&sdev->event_list);
265 spin_lock_init(&sdev->list_lock);
266 INIT_WORK(&sdev->event_work, scsi_evt_thread);
267
268 sdev->sdev_gendev.parent = get_device(&starget->dev);
269 sdev->sdev_target = starget;
270
271 /* usually NULL and set by ->slave_alloc instead */
272 sdev->hostdata = hostdata;
273
274 /* if the device needs this changing, it may do so in the
275 * slave_configure function */
276 sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED;
277
278 /*
279 * Some low level driver could use device->type
280 */
281 sdev->type = -1;
282
283 /*
284 * Assume that the device will have handshaking problems,
285 * and then fix this field later if it turns out it
286 * doesn't
287 */
288 sdev->borken = 1;
289
290 sdev->request_queue = scsi_alloc_queue(sdev);
291 if (!sdev->request_queue) {
292 /* release fn is set up in scsi_sysfs_device_initialise, so
293 * have to free and put manually here */
294 put_device(&starget->dev);
295 kfree(sdev);
296 goto out;
297 }
298
299 sdev->request_queue->queuedata = sdev;
300 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
301
302 scsi_sysfs_device_initialize(sdev);
303
304 if (shost->hostt->slave_alloc) {
305 ret = shost->hostt->slave_alloc(sdev);
306 if (ret) {
307 /*
308 * if LLDD reports slave not present, don't clutter
309 * console with alloc failure messages
310 */
311 if (ret == -ENXIO)
312 display_failure_msg = 0;
313 goto out_device_destroy;
314 }
315 }
316
317 return sdev;
318
319 out_device_destroy:
320 scsi_device_set_state(sdev, SDEV_DEL);
321 transport_destroy_device(&sdev->sdev_gendev);
322 put_device(&sdev->sdev_gendev);
323 out:
324 if (display_failure_msg)
325 printk(ALLOC_FAILURE_MSG, __func__);
326 return NULL;
327 }
328
scsi_target_destroy(struct scsi_target * starget)329 static 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
scsi_target_dev_release(struct device * dev)344 static 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
353 static struct device_type scsi_target_type = {
354 .name = "scsi_target",
355 .release = scsi_target_dev_release,
356 };
357
scsi_is_target_device(const struct device * dev)358 int scsi_is_target_device(const struct device *dev)
359 {
360 return dev->type == &scsi_target_type;
361 }
362 EXPORT_SYMBOL(scsi_is_target_device);
363
__scsi_find_target(struct device * parent,int channel,uint id)364 static 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 */
scsi_alloc_target(struct device * parent,int channel,uint id)397 static 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 #ifndef CONFIG_SYSFS_DEPRECATED
420 dev->bus = &scsi_bus_type;
421 #endif
422 dev->type = &scsi_target_type;
423 starget->id = id;
424 starget->channel = channel;
425 starget->can_queue = 0;
426 INIT_LIST_HEAD(&starget->siblings);
427 INIT_LIST_HEAD(&starget->devices);
428 starget->state = STARGET_CREATED;
429 starget->scsi_level = SCSI_2;
430 retry:
431 spin_lock_irqsave(shost->host_lock, flags);
432
433 found_target = __scsi_find_target(parent, channel, id);
434 if (found_target)
435 goto found;
436
437 list_add_tail(&starget->siblings, &shost->__targets);
438 spin_unlock_irqrestore(shost->host_lock, flags);
439 /* allocate and add */
440 transport_setup_device(dev);
441 if (shost->hostt->target_alloc) {
442 error = shost->hostt->target_alloc(starget);
443
444 if(error) {
445 dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error);
446 /* don't want scsi_target_reap to do the final
447 * put because it will be under the host lock */
448 scsi_target_destroy(starget);
449 return NULL;
450 }
451 }
452 get_device(dev);
453
454 return starget;
455
456 found:
457 found_target->reap_ref++;
458 spin_unlock_irqrestore(shost->host_lock, flags);
459 if (found_target->state != STARGET_DEL) {
460 put_device(parent);
461 kfree(starget);
462 return found_target;
463 }
464 /* Unfortunately, we found a dying target; need to
465 * wait until it's dead before we can get a new one */
466 put_device(&found_target->dev);
467 flush_scheduled_work();
468 goto retry;
469 }
470
scsi_target_reap_usercontext(struct work_struct * work)471 static void scsi_target_reap_usercontext(struct work_struct *work)
472 {
473 struct scsi_target *starget =
474 container_of(work, struct scsi_target, ew.work);
475
476 transport_remove_device(&starget->dev);
477 device_del(&starget->dev);
478 scsi_target_destroy(starget);
479 }
480
481 /**
482 * scsi_target_reap - check to see if target is in use and destroy if not
483 * @starget: target to be checked
484 *
485 * This is used after removing a LUN or doing a last put of the target
486 * it checks atomically that nothing is using the target and removes
487 * it if so.
488 */
scsi_target_reap(struct scsi_target * starget)489 void scsi_target_reap(struct scsi_target *starget)
490 {
491 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
492 unsigned long flags;
493 enum scsi_target_state state;
494 int empty;
495
496 spin_lock_irqsave(shost->host_lock, flags);
497 state = starget->state;
498 empty = --starget->reap_ref == 0 &&
499 list_empty(&starget->devices) ? 1 : 0;
500 spin_unlock_irqrestore(shost->host_lock, flags);
501
502 if (!empty)
503 return;
504
505 BUG_ON(state == STARGET_DEL);
506 starget->state = STARGET_DEL;
507 if (state == STARGET_CREATED)
508 scsi_target_destroy(starget);
509 else
510 execute_in_process_context(scsi_target_reap_usercontext,
511 &starget->ew);
512 }
513
514 /**
515 * sanitize_inquiry_string - remove non-graphical chars from an INQUIRY result string
516 * @s: INQUIRY result string to sanitize
517 * @len: length of the string
518 *
519 * Description:
520 * The SCSI spec says that INQUIRY vendor, product, and revision
521 * strings must consist entirely of graphic ASCII characters,
522 * padded on the right with spaces. Since not all devices obey
523 * this rule, we will replace non-graphic or non-ASCII characters
524 * with spaces. Exception: a NUL character is interpreted as a
525 * string terminator, so all the following characters are set to
526 * spaces.
527 **/
sanitize_inquiry_string(unsigned char * s,int len)528 static void sanitize_inquiry_string(unsigned char *s, int len)
529 {
530 int terminated = 0;
531
532 for (; len > 0; (--len, ++s)) {
533 if (*s == 0)
534 terminated = 1;
535 if (terminated || *s < 0x20 || *s > 0x7e)
536 *s = ' ';
537 }
538 }
539
540 /**
541 * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
542 * @sdev: scsi_device to probe
543 * @inq_result: area to store the INQUIRY result
544 * @result_len: len of inq_result
545 * @bflags: store any bflags found here
546 *
547 * Description:
548 * Probe the lun associated with @req using a standard SCSI INQUIRY;
549 *
550 * If the INQUIRY is successful, zero is returned and the
551 * INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
552 * are copied to the scsi_device any flags value is stored in *@bflags.
553 **/
scsi_probe_lun(struct scsi_device * sdev,unsigned char * inq_result,int result_len,int * bflags)554 static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
555 int result_len, int *bflags)
556 {
557 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
558 int first_inquiry_len, try_inquiry_len, next_inquiry_len;
559 int response_len = 0;
560 int pass, count, result;
561 struct scsi_sense_hdr sshdr;
562
563 *bflags = 0;
564
565 /* Perform up to 3 passes. The first pass uses a conservative
566 * transfer length of 36 unless sdev->inquiry_len specifies a
567 * different value. */
568 first_inquiry_len = sdev->inquiry_len ? sdev->inquiry_len : 36;
569 try_inquiry_len = first_inquiry_len;
570 pass = 1;
571
572 next_pass:
573 SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev,
574 "scsi scan: INQUIRY pass %d length %d\n",
575 pass, try_inquiry_len));
576
577 /* Each pass gets up to three chances to ignore Unit Attention */
578 for (count = 0; count < 3; ++count) {
579 int resid;
580
581 memset(scsi_cmd, 0, 6);
582 scsi_cmd[0] = INQUIRY;
583 scsi_cmd[4] = (unsigned char) try_inquiry_len;
584
585 memset(inq_result, 0, try_inquiry_len);
586
587 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
588 inq_result, try_inquiry_len, &sshdr,
589 HZ / 2 + HZ * scsi_inq_timeout, 3,
590 &resid);
591
592 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
593 "with code 0x%x\n",
594 result ? "failed" : "successful", result));
595
596 if (result) {
597 /*
598 * not-ready to ready transition [asc/ascq=0x28/0x0]
599 * or power-on, reset [asc/ascq=0x29/0x0], continue.
600 * INQUIRY should not yield UNIT_ATTENTION
601 * but many buggy devices do so anyway.
602 */
603 if ((driver_byte(result) & DRIVER_SENSE) &&
604 scsi_sense_valid(&sshdr)) {
605 if ((sshdr.sense_key == UNIT_ATTENTION) &&
606 ((sshdr.asc == 0x28) ||
607 (sshdr.asc == 0x29)) &&
608 (sshdr.ascq == 0))
609 continue;
610 }
611 } else {
612 /*
613 * if nothing was transferred, we try
614 * again. It's a workaround for some USB
615 * devices.
616 */
617 if (resid == try_inquiry_len)
618 continue;
619 }
620 break;
621 }
622
623 if (result == 0) {
624 sanitize_inquiry_string(&inq_result[8], 8);
625 sanitize_inquiry_string(&inq_result[16], 16);
626 sanitize_inquiry_string(&inq_result[32], 4);
627
628 response_len = inq_result[4] + 5;
629 if (response_len > 255)
630 response_len = first_inquiry_len; /* sanity */
631
632 /*
633 * Get any flags for this device.
634 *
635 * XXX add a bflags to scsi_device, and replace the
636 * corresponding bit fields in scsi_device, so bflags
637 * need not be passed as an argument.
638 */
639 *bflags = scsi_get_device_flags(sdev, &inq_result[8],
640 &inq_result[16]);
641
642 /* When the first pass succeeds we gain information about
643 * what larger transfer lengths might work. */
644 if (pass == 1) {
645 if (BLIST_INQUIRY_36 & *bflags)
646 next_inquiry_len = 36;
647 else if (BLIST_INQUIRY_58 & *bflags)
648 next_inquiry_len = 58;
649 else if (sdev->inquiry_len)
650 next_inquiry_len = sdev->inquiry_len;
651 else
652 next_inquiry_len = response_len;
653
654 /* If more data is available perform the second pass */
655 if (next_inquiry_len > try_inquiry_len) {
656 try_inquiry_len = next_inquiry_len;
657 pass = 2;
658 goto next_pass;
659 }
660 }
661
662 } else if (pass == 2) {
663 printk(KERN_INFO "scsi scan: %d byte inquiry failed. "
664 "Consider BLIST_INQUIRY_36 for this device\n",
665 try_inquiry_len);
666
667 /* If this pass failed, the third pass goes back and transfers
668 * the same amount as we successfully got in the first pass. */
669 try_inquiry_len = first_inquiry_len;
670 pass = 3;
671 goto next_pass;
672 }
673
674 /* If the last transfer attempt got an error, assume the
675 * peripheral doesn't exist or is dead. */
676 if (result)
677 return -EIO;
678
679 /* Don't report any more data than the device says is valid */
680 sdev->inquiry_len = min(try_inquiry_len, response_len);
681
682 /*
683 * XXX Abort if the response length is less than 36? If less than
684 * 32, the lookup of the device flags (above) could be invalid,
685 * and it would be possible to take an incorrect action - we do
686 * not want to hang because of a short INQUIRY. On the flip side,
687 * if the device is spun down or becoming ready (and so it gives a
688 * short INQUIRY), an abort here prevents any further use of the
689 * device, including spin up.
690 *
691 * On the whole, the best approach seems to be to assume the first
692 * 36 bytes are valid no matter what the device says. That's
693 * better than copying < 36 bytes to the inquiry-result buffer
694 * and displaying garbage for the Vendor, Product, or Revision
695 * strings.
696 */
697 if (sdev->inquiry_len < 36) {
698 printk(KERN_INFO "scsi scan: INQUIRY result too short (%d),"
699 " using 36\n", sdev->inquiry_len);
700 sdev->inquiry_len = 36;
701 }
702
703 /*
704 * Related to the above issue:
705 *
706 * XXX Devices (disk or all?) should be sent a TEST UNIT READY,
707 * and if not ready, sent a START_STOP to start (maybe spin up) and
708 * then send the INQUIRY again, since the INQUIRY can change after
709 * a device is initialized.
710 *
711 * Ideally, start a device if explicitly asked to do so. This
712 * assumes that a device is spun up on power on, spun down on
713 * request, and then spun up on request.
714 */
715
716 /*
717 * The scanning code needs to know the scsi_level, even if no
718 * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so
719 * non-zero LUNs can be scanned.
720 */
721 sdev->scsi_level = inq_result[2] & 0x07;
722 if (sdev->scsi_level >= 2 ||
723 (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
724 sdev->scsi_level++;
725 sdev->sdev_target->scsi_level = sdev->scsi_level;
726
727 return 0;
728 }
729
730 /**
731 * scsi_add_lun - allocate and fully initialze a scsi_device
732 * @sdev: holds information to be stored in the new scsi_device
733 * @inq_result: holds the result of a previous INQUIRY to the LUN
734 * @bflags: black/white list flag
735 * @async: 1 if this device is being scanned asynchronously
736 *
737 * Description:
738 * Initialize the scsi_device @sdev. Optionally set fields based
739 * on values in *@bflags.
740 *
741 * Return:
742 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
743 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
744 **/
scsi_add_lun(struct scsi_device * sdev,unsigned char * inq_result,int * bflags,int async)745 static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
746 int *bflags, int async)
747 {
748 int ret;
749
750 /*
751 * XXX do not save the inquiry, since it can change underneath us,
752 * save just vendor/model/rev.
753 *
754 * Rather than save it and have an ioctl that retrieves the saved
755 * value, have an ioctl that executes the same INQUIRY code used
756 * in scsi_probe_lun, let user level programs doing INQUIRY
757 * scanning run at their own risk, or supply a user level program
758 * that can correctly scan.
759 */
760
761 /*
762 * Copy at least 36 bytes of INQUIRY data, so that we don't
763 * dereference unallocated memory when accessing the Vendor,
764 * Product, and Revision strings. Badly behaved devices may set
765 * the INQUIRY Additional Length byte to a small value, indicating
766 * these strings are invalid, but often they contain plausible data
767 * nonetheless. It doesn't matter if the device sent < 36 bytes
768 * total, since scsi_probe_lun() initializes inq_result with 0s.
769 */
770 sdev->inquiry = kmemdup(inq_result,
771 max_t(size_t, sdev->inquiry_len, 36),
772 GFP_ATOMIC);
773 if (sdev->inquiry == NULL)
774 return SCSI_SCAN_NO_RESPONSE;
775
776 sdev->vendor = (char *) (sdev->inquiry + 8);
777 sdev->model = (char *) (sdev->inquiry + 16);
778 sdev->rev = (char *) (sdev->inquiry + 32);
779
780 if (*bflags & BLIST_ISROM) {
781 sdev->type = TYPE_ROM;
782 sdev->removable = 1;
783 } else {
784 sdev->type = (inq_result[0] & 0x1f);
785 sdev->removable = (inq_result[1] & 0x80) >> 7;
786 }
787
788 switch (sdev->type) {
789 case TYPE_RBC:
790 case TYPE_TAPE:
791 case TYPE_DISK:
792 case TYPE_PRINTER:
793 case TYPE_MOD:
794 case TYPE_PROCESSOR:
795 case TYPE_SCANNER:
796 case TYPE_MEDIUM_CHANGER:
797 case TYPE_ENCLOSURE:
798 case TYPE_COMM:
799 case TYPE_RAID:
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_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 /*
944 * Ok, the device is now all set up, we can
945 * register it and tell the rest of the kernel
946 * about it.
947 */
948 if (!async && scsi_sysfs_add_sdev(sdev) != 0)
949 return SCSI_SCAN_NO_RESPONSE;
950
951 return SCSI_SCAN_LUN_PRESENT;
952 }
953
scsi_destroy_sdev(struct scsi_device * sdev)954 static inline void scsi_destroy_sdev(struct scsi_device *sdev)
955 {
956 scsi_device_set_state(sdev, SDEV_DEL);
957 if (sdev->host->hostt->slave_destroy)
958 sdev->host->hostt->slave_destroy(sdev);
959 transport_destroy_device(&sdev->sdev_gendev);
960 put_device(&sdev->sdev_gendev);
961 }
962
963 #ifdef CONFIG_SCSI_LOGGING
964 /**
965 * scsi_inq_str - print INQUIRY data from min to max index, strip trailing whitespace
966 * @buf: Output buffer with at least end-first+1 bytes of space
967 * @inq: Inquiry buffer (input)
968 * @first: Offset of string into inq
969 * @end: Index after last character in inq
970 */
scsi_inq_str(unsigned char * buf,unsigned char * inq,unsigned first,unsigned end)971 static unsigned char *scsi_inq_str(unsigned char *buf, unsigned char *inq,
972 unsigned first, unsigned end)
973 {
974 unsigned term = 0, idx;
975
976 for (idx = 0; idx + first < end && idx + first < inq[4] + 5; idx++) {
977 if (inq[idx+first] > ' ') {
978 buf[idx] = inq[idx+first];
979 term = idx+1;
980 } else {
981 buf[idx] = ' ';
982 }
983 }
984 buf[term] = 0;
985 return buf;
986 }
987 #endif
988
989 /**
990 * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
991 * @starget: pointer to target device structure
992 * @lun: LUN of target device
993 * @bflagsp: store bflags here if not NULL
994 * @sdevp: probe the LUN corresponding to this scsi_device
995 * @rescan: if nonzero skip some code only needed on first scan
996 * @hostdata: passed to scsi_alloc_sdev()
997 *
998 * Description:
999 * Call scsi_probe_lun, if a LUN with an attached device is found,
1000 * allocate and set it up by calling scsi_add_lun.
1001 *
1002 * Return:
1003 * SCSI_SCAN_NO_RESPONSE: could not allocate or setup a scsi_device
1004 * SCSI_SCAN_TARGET_PRESENT: target responded, but no device is
1005 * attached at the LUN
1006 * SCSI_SCAN_LUN_PRESENT: a new scsi_device was allocated and initialized
1007 **/
scsi_probe_and_add_lun(struct scsi_target * starget,uint lun,int * bflagsp,struct scsi_device ** sdevp,int rescan,void * hostdata)1008 static int scsi_probe_and_add_lun(struct scsi_target *starget,
1009 uint lun, int *bflagsp,
1010 struct scsi_device **sdevp, int rescan,
1011 void *hostdata)
1012 {
1013 struct scsi_device *sdev;
1014 unsigned char *result;
1015 int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
1016 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1017
1018 /*
1019 * The rescan flag is used as an optimization, the first scan of a
1020 * host adapter calls into here with rescan == 0.
1021 */
1022 sdev = scsi_device_lookup_by_target(starget, lun);
1023 if (sdev) {
1024 if (rescan || !scsi_device_created(sdev)) {
1025 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1026 "scsi scan: device exists on %s\n",
1027 dev_name(&sdev->sdev_gendev)));
1028 if (sdevp)
1029 *sdevp = sdev;
1030 else
1031 scsi_device_put(sdev);
1032
1033 if (bflagsp)
1034 *bflagsp = scsi_get_device_flags(sdev,
1035 sdev->vendor,
1036 sdev->model);
1037 return SCSI_SCAN_LUN_PRESENT;
1038 }
1039 scsi_device_put(sdev);
1040 } else
1041 sdev = scsi_alloc_sdev(starget, lun, hostdata);
1042 if (!sdev)
1043 goto out;
1044
1045 result = kmalloc(result_len, GFP_ATOMIC |
1046 ((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
1047 if (!result)
1048 goto out_free_sdev;
1049
1050 if (scsi_probe_lun(sdev, result, result_len, &bflags))
1051 goto out_free_result;
1052
1053 if (bflagsp)
1054 *bflagsp = bflags;
1055 /*
1056 * result contains valid SCSI INQUIRY data.
1057 */
1058 if (((result[0] >> 5) == 3) && !(bflags & BLIST_ATTACH_PQ3)) {
1059 /*
1060 * For a Peripheral qualifier 3 (011b), the SCSI
1061 * spec says: The device server is not capable of
1062 * supporting a physical device on this logical
1063 * unit.
1064 *
1065 * For disks, this implies that there is no
1066 * logical disk configured at sdev->lun, but there
1067 * is a target id responding.
1068 */
1069 SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
1070 " peripheral qualifier of 3, device not"
1071 " added\n"))
1072 if (lun == 0) {
1073 SCSI_LOG_SCAN_BUS(1, {
1074 unsigned char vend[9];
1075 unsigned char mod[17];
1076
1077 sdev_printk(KERN_INFO, sdev,
1078 "scsi scan: consider passing scsi_mod."
1079 "dev_flags=%s:%s:0x240 or 0x1000240\n",
1080 scsi_inq_str(vend, result, 8, 16),
1081 scsi_inq_str(mod, result, 16, 32));
1082 });
1083
1084 }
1085
1086 res = SCSI_SCAN_TARGET_PRESENT;
1087 goto out_free_result;
1088 }
1089
1090 /*
1091 * Some targets may set slight variations of PQ and PDT to signal
1092 * that no LUN is present, so don't add sdev in these cases.
1093 * Two specific examples are:
1094 * 1) NetApp targets: return PQ=1, PDT=0x1f
1095 * 2) USB UFI: returns PDT=0x1f, with the PQ bits being "reserved"
1096 * in the UFI 1.0 spec (we cannot rely on reserved bits).
1097 *
1098 * References:
1099 * 1) SCSI SPC-3, pp. 145-146
1100 * PQ=1: "A peripheral device having the specified peripheral
1101 * device type is not connected to this logical unit. However, the
1102 * device server is capable of supporting the specified peripheral
1103 * device type on this logical unit."
1104 * PDT=0x1f: "Unknown or no device type"
1105 * 2) USB UFI 1.0, p. 20
1106 * PDT=00h Direct-access device (floppy)
1107 * PDT=1Fh none (no FDD connected to the requested logical unit)
1108 */
1109 if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
1110 (result[0] & 0x1f) == 0x1f &&
1111 !scsi_is_wlun(lun)) {
1112 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
1113 "scsi scan: peripheral device type"
1114 " of 31, no device added\n"));
1115 res = SCSI_SCAN_TARGET_PRESENT;
1116 goto out_free_result;
1117 }
1118
1119 res = scsi_add_lun(sdev, result, &bflags, shost->async_scan);
1120 if (res == SCSI_SCAN_LUN_PRESENT) {
1121 if (bflags & BLIST_KEY) {
1122 sdev->lockable = 0;
1123 scsi_unlock_floptical(sdev, result);
1124 }
1125 }
1126
1127 out_free_result:
1128 kfree(result);
1129 out_free_sdev:
1130 if (res == SCSI_SCAN_LUN_PRESENT) {
1131 if (sdevp) {
1132 if (scsi_device_get(sdev) == 0) {
1133 *sdevp = sdev;
1134 } else {
1135 __scsi_remove_device(sdev);
1136 res = SCSI_SCAN_NO_RESPONSE;
1137 }
1138 }
1139 } else
1140 scsi_destroy_sdev(sdev);
1141 out:
1142 return res;
1143 }
1144
1145 /**
1146 * scsi_sequential_lun_scan - sequentially scan a SCSI target
1147 * @starget: pointer to target structure to scan
1148 * @bflags: black/white list flag for LUN 0
1149 * @scsi_level: Which version of the standard does this device adhere to
1150 * @rescan: passed to scsi_probe_add_lun()
1151 *
1152 * Description:
1153 * Generally, scan from LUN 1 (LUN 0 is assumed to already have been
1154 * scanned) to some maximum lun until a LUN is found with no device
1155 * attached. Use the bflags to figure out any oddities.
1156 *
1157 * Modifies sdevscan->lun.
1158 **/
scsi_sequential_lun_scan(struct scsi_target * starget,int bflags,int scsi_level,int rescan)1159 static void scsi_sequential_lun_scan(struct scsi_target *starget,
1160 int bflags, int scsi_level, int rescan)
1161 {
1162 unsigned int sparse_lun, lun, max_dev_lun;
1163 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1164
1165 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: Sequential scan of"
1166 "%s\n", dev_name(&starget->dev)));
1167
1168 max_dev_lun = min(max_scsi_luns, shost->max_lun);
1169 /*
1170 * If this device is known to support sparse multiple units,
1171 * override the other settings, and scan all of them. Normally,
1172 * SCSI-3 devices should be scanned via the REPORT LUNS.
1173 */
1174 if (bflags & BLIST_SPARSELUN) {
1175 max_dev_lun = shost->max_lun;
1176 sparse_lun = 1;
1177 } else
1178 sparse_lun = 0;
1179
1180 /*
1181 * If less than SCSI_1_CSS, and no special lun scaning, stop
1182 * scanning; this matches 2.4 behaviour, but could just be a bug
1183 * (to continue scanning a SCSI_1_CSS device).
1184 *
1185 * This test is broken. We might not have any device on lun0 for
1186 * a sparselun device, and if that's the case then how would we
1187 * know the real scsi_level, eh? It might make sense to just not
1188 * scan any SCSI_1 device for non-0 luns, but that check would best
1189 * go into scsi_alloc_sdev() and just have it return null when asked
1190 * to alloc an sdev for lun > 0 on an already found SCSI_1 device.
1191 *
1192 if ((sdevscan->scsi_level < SCSI_1_CCS) &&
1193 ((bflags & (BLIST_FORCELUN | BLIST_SPARSELUN | BLIST_MAX5LUN))
1194 == 0))
1195 return;
1196 */
1197 /*
1198 * If this device is known to support multiple units, override
1199 * the other settings, and scan all of them.
1200 */
1201 if (bflags & BLIST_FORCELUN)
1202 max_dev_lun = shost->max_lun;
1203 /*
1204 * REGAL CDC-4X: avoid hang after LUN 4
1205 */
1206 if (bflags & BLIST_MAX5LUN)
1207 max_dev_lun = min(5U, max_dev_lun);
1208 /*
1209 * Do not scan SCSI-2 or lower device past LUN 7, unless
1210 * BLIST_LARGELUN.
1211 */
1212 if (scsi_level < SCSI_3 && !(bflags & BLIST_LARGELUN))
1213 max_dev_lun = min(8U, max_dev_lun);
1214
1215 /*
1216 * We have already scanned LUN 0, so start at LUN 1. Keep scanning
1217 * until we reach the max, or no LUN is found and we are not
1218 * sparse_lun.
1219 */
1220 for (lun = 1; lun < max_dev_lun; ++lun)
1221 if ((scsi_probe_and_add_lun(starget, lun, NULL, NULL, rescan,
1222 NULL) != SCSI_SCAN_LUN_PRESENT) &&
1223 !sparse_lun)
1224 return;
1225 }
1226
1227 /**
1228 * scsilun_to_int: convert a scsi_lun to an int
1229 * @scsilun: struct scsi_lun to be converted.
1230 *
1231 * Description:
1232 * Convert @scsilun from a struct scsi_lun to a four byte host byte-ordered
1233 * integer, and return the result. The caller must check for
1234 * truncation before using this function.
1235 *
1236 * Notes:
1237 * The struct scsi_lun is assumed to be four levels, with each level
1238 * effectively containing a SCSI byte-ordered (big endian) short; the
1239 * addressing bits of each level are ignored (the highest two bits).
1240 * For a description of the LUN format, post SCSI-3 see the SCSI
1241 * Architecture Model, for SCSI-3 see the SCSI Controller Commands.
1242 *
1243 * Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
1244 * the integer: 0x0b030a04
1245 **/
scsilun_to_int(struct scsi_lun * scsilun)1246 int scsilun_to_int(struct scsi_lun *scsilun)
1247 {
1248 int i;
1249 unsigned int lun;
1250
1251 lun = 0;
1252 for (i = 0; i < sizeof(lun); i += 2)
1253 lun = lun | (((scsilun->scsi_lun[i] << 8) |
1254 scsilun->scsi_lun[i + 1]) << (i * 8));
1255 return lun;
1256 }
1257 EXPORT_SYMBOL(scsilun_to_int);
1258
1259 /**
1260 * int_to_scsilun: reverts an int into a scsi_lun
1261 * @lun: integer to be reverted
1262 * @scsilun: struct scsi_lun to be set.
1263 *
1264 * Description:
1265 * Reverts the functionality of the scsilun_to_int, which packed
1266 * an 8-byte lun value into an int. This routine unpacks the int
1267 * back into the lun value.
1268 * Note: the scsilun_to_int() routine does not truly handle all
1269 * 8bytes of the lun value. This functions restores only as much
1270 * as was set by the routine.
1271 *
1272 * Notes:
1273 * Given an integer : 0x0b030a04, this function returns a
1274 * scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00
1275 *
1276 **/
int_to_scsilun(unsigned int lun,struct scsi_lun * scsilun)1277 void int_to_scsilun(unsigned int lun, struct scsi_lun *scsilun)
1278 {
1279 int i;
1280
1281 memset(scsilun->scsi_lun, 0, sizeof(scsilun->scsi_lun));
1282
1283 for (i = 0; i < sizeof(lun); i += 2) {
1284 scsilun->scsi_lun[i] = (lun >> 8) & 0xFF;
1285 scsilun->scsi_lun[i+1] = lun & 0xFF;
1286 lun = lun >> 16;
1287 }
1288 }
1289 EXPORT_SYMBOL(int_to_scsilun);
1290
1291 /**
1292 * scsi_report_lun_scan - Scan using SCSI REPORT LUN results
1293 * @starget: which target
1294 * @bflags: Zero or a mix of BLIST_NOLUN, BLIST_REPORTLUN2, or BLIST_NOREPORTLUN
1295 * @rescan: nonzero if we can skip code only needed on first scan
1296 *
1297 * Description:
1298 * Fast scanning for modern (SCSI-3) devices by sending a REPORT LUN command.
1299 * Scan the resulting list of LUNs by calling scsi_probe_and_add_lun.
1300 *
1301 * If BLINK_REPORTLUN2 is set, scan a target that supports more than 8
1302 * LUNs even if it's older than SCSI-3.
1303 * If BLIST_NOREPORTLUN is set, return 1 always.
1304 * If BLIST_NOLUN is set, return 0 always.
1305 *
1306 * Return:
1307 * 0: scan completed (or no memory, so further scanning is futile)
1308 * 1: could not scan with REPORT LUN
1309 **/
scsi_report_lun_scan(struct scsi_target * starget,int bflags,int rescan)1310 static int scsi_report_lun_scan(struct scsi_target *starget, int bflags,
1311 int rescan)
1312 {
1313 char devname[64];
1314 unsigned char scsi_cmd[MAX_COMMAND_SIZE];
1315 unsigned int length;
1316 unsigned int lun;
1317 unsigned int num_luns;
1318 unsigned int retries;
1319 int result;
1320 struct scsi_lun *lunp, *lun_data;
1321 u8 *data;
1322 struct scsi_sense_hdr sshdr;
1323 struct scsi_device *sdev;
1324 struct Scsi_Host *shost = dev_to_shost(&starget->dev);
1325 int ret = 0;
1326
1327 /*
1328 * Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
1329 * Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
1330 * support more than 8 LUNs.
1331 */
1332 if (bflags & BLIST_NOREPORTLUN)
1333 return 1;
1334 if (starget->scsi_level < SCSI_2 &&
1335 starget->scsi_level != SCSI_UNKNOWN)
1336 return 1;
1337 if (starget->scsi_level < SCSI_3 &&
1338 (!(bflags & BLIST_REPORTLUN2) || shost->max_lun <= 8))
1339 return 1;
1340 if (bflags & BLIST_NOLUN)
1341 return 0;
1342
1343 if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
1344 sdev = scsi_alloc_sdev(starget, 0, NULL);
1345 if (!sdev)
1346 return 0;
1347 if (scsi_device_get(sdev))
1348 return 0;
1349 }
1350
1351 sprintf(devname, "host %d channel %d id %d",
1352 shost->host_no, sdev->channel, sdev->id);
1353
1354 /*
1355 * Allocate enough to hold the header (the same size as one scsi_lun)
1356 * plus the max number of luns we are requesting.
1357 *
1358 * Reallocating and trying again (with the exact amount we need)
1359 * would be nice, but then we need to somehow limit the size
1360 * allocated based on the available memory and the limits of
1361 * kmalloc - we don't want a kmalloc() failure of a huge value to
1362 * prevent us from finding any LUNs on this target.
1363 */
1364 length = (max_scsi_report_luns + 1) * sizeof(struct scsi_lun);
1365 lun_data = kmalloc(length, GFP_ATOMIC |
1366 (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
1367 if (!lun_data) {
1368 printk(ALLOC_FAILURE_MSG, __func__);
1369 goto out;
1370 }
1371
1372 scsi_cmd[0] = REPORT_LUNS;
1373
1374 /*
1375 * bytes 1 - 5: reserved, set to zero.
1376 */
1377 memset(&scsi_cmd[1], 0, 5);
1378
1379 /*
1380 * bytes 6 - 9: length of the command.
1381 */
1382 scsi_cmd[6] = (unsigned char) (length >> 24) & 0xff;
1383 scsi_cmd[7] = (unsigned char) (length >> 16) & 0xff;
1384 scsi_cmd[8] = (unsigned char) (length >> 8) & 0xff;
1385 scsi_cmd[9] = (unsigned char) length & 0xff;
1386
1387 scsi_cmd[10] = 0; /* reserved */
1388 scsi_cmd[11] = 0; /* control */
1389
1390 /*
1391 * We can get a UNIT ATTENTION, for example a power on/reset, so
1392 * retry a few times (like sd.c does for TEST UNIT READY).
1393 * Experience shows some combinations of adapter/devices get at
1394 * least two power on/resets.
1395 *
1396 * Illegal requests (for devices that do not support REPORT LUNS)
1397 * should come through as a check condition, and will not generate
1398 * a retry.
1399 */
1400 for (retries = 0; retries < 3; retries++) {
1401 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
1402 " REPORT LUNS to %s (try %d)\n", devname,
1403 retries));
1404
1405 result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
1406 lun_data, length, &sshdr,
1407 SCSI_TIMEOUT + 4 * HZ, 3, NULL);
1408
1409 SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
1410 " %s (try %d) result 0x%x\n", result
1411 ? "failed" : "successful", retries, result));
1412 if (result == 0)
1413 break;
1414 else if (scsi_sense_valid(&sshdr)) {
1415 if (sshdr.sense_key != UNIT_ATTENTION)
1416 break;
1417 }
1418 }
1419
1420 if (result) {
1421 /*
1422 * The device probably does not support a REPORT LUN command
1423 */
1424 ret = 1;
1425 goto out_err;
1426 }
1427
1428 /*
1429 * Get the length from the first four bytes of lun_data.
1430 */
1431 data = (u8 *) lun_data->scsi_lun;
1432 length = ((data[0] << 24) | (data[1] << 16) |
1433 (data[2] << 8) | (data[3] << 0));
1434
1435 num_luns = (length / sizeof(struct scsi_lun));
1436 if (num_luns > max_scsi_report_luns) {
1437 printk(KERN_WARNING "scsi: On %s only %d (max_scsi_report_luns)"
1438 " of %d luns reported, try increasing"
1439 " max_scsi_report_luns.\n", devname,
1440 max_scsi_report_luns, num_luns);
1441 num_luns = max_scsi_report_luns;
1442 }
1443
1444 SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
1445 "scsi scan: REPORT LUN scan\n"));
1446
1447 /*
1448 * Scan the luns in lun_data. The entry at offset 0 is really
1449 * the header, so start at 1 and go up to and including num_luns.
1450 */
1451 for (lunp = &lun_data[1]; lunp <= &lun_data[num_luns]; lunp++) {
1452 lun = scsilun_to_int(lunp);
1453
1454 /*
1455 * Check if the unused part of lunp is non-zero, and so
1456 * does not fit in lun.
1457 */
1458 if (memcmp(&lunp->scsi_lun[sizeof(lun)], "\0\0\0\0", 4)) {
1459 int i;
1460
1461 /*
1462 * Output an error displaying the LUN in byte order,
1463 * this differs from what linux would print for the
1464 * integer LUN value.
1465 */
1466 printk(KERN_WARNING "scsi: %s lun 0x", devname);
1467 data = (char *)lunp->scsi_lun;
1468 for (i = 0; i < sizeof(struct scsi_lun); i++)
1469 printk("%02x", data[i]);
1470 printk(" has a LUN larger than currently supported.\n");
1471 } else if (lun > sdev->host->max_lun) {
1472 printk(KERN_WARNING "scsi: %s lun%d has a LUN larger"
1473 " than allowed by the host adapter\n",
1474 devname, lun);
1475 } else {
1476 int res;
1477
1478 res = scsi_probe_and_add_lun(starget,
1479 lun, NULL, NULL, rescan, NULL);
1480 if (res == SCSI_SCAN_NO_RESPONSE) {
1481 /*
1482 * Got some results, but now none, abort.
1483 */
1484 sdev_printk(KERN_ERR, sdev,
1485 "Unexpected response"
1486 " from lun %d while scanning, scan"
1487 " aborted\n", lun);
1488 break;
1489 }
1490 }
1491 }
1492
1493 out_err:
1494 kfree(lun_data);
1495 out:
1496 scsi_device_put(sdev);
1497 if (scsi_device_created(sdev))
1498 /*
1499 * the sdev we used didn't appear in the report luns scan
1500 */
1501 scsi_destroy_sdev(sdev);
1502 return ret;
1503 }
1504
__scsi_add_device(struct Scsi_Host * shost,uint channel,uint id,uint lun,void * hostdata)1505 struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel,
1506 uint id, uint lun, void *hostdata)
1507 {
1508 struct scsi_device *sdev = ERR_PTR(-ENODEV);
1509 struct device *parent = &shost->shost_gendev;
1510 struct scsi_target *starget;
1511
1512 if (strncmp(scsi_scan_type, "none", 4) == 0)
1513 return ERR_PTR(-ENODEV);
1514
1515 starget = scsi_alloc_target(parent, channel, id);
1516 if (!starget)
1517 return ERR_PTR(-ENOMEM);
1518
1519 mutex_lock(&shost->scan_mutex);
1520 if (!shost->async_scan)
1521 scsi_complete_async_scans();
1522
1523 if (scsi_host_scan_allowed(shost))
1524 scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata);
1525 mutex_unlock(&shost->scan_mutex);
1526 scsi_target_reap(starget);
1527 put_device(&starget->dev);
1528
1529 return sdev;
1530 }
1531 EXPORT_SYMBOL(__scsi_add_device);
1532
scsi_add_device(struct Scsi_Host * host,uint channel,uint target,uint lun)1533 int scsi_add_device(struct Scsi_Host *host, uint channel,
1534 uint target, uint lun)
1535 {
1536 struct scsi_device *sdev =
1537 __scsi_add_device(host, channel, target, lun, NULL);
1538 if (IS_ERR(sdev))
1539 return PTR_ERR(sdev);
1540
1541 scsi_device_put(sdev);
1542 return 0;
1543 }
1544 EXPORT_SYMBOL(scsi_add_device);
1545
scsi_rescan_device(struct device * dev)1546 void scsi_rescan_device(struct device *dev)
1547 {
1548 struct scsi_driver *drv;
1549
1550 if (!dev->driver)
1551 return;
1552
1553 drv = to_scsi_driver(dev->driver);
1554 if (try_module_get(drv->owner)) {
1555 if (drv->rescan)
1556 drv->rescan(dev);
1557 module_put(drv->owner);
1558 }
1559 }
1560 EXPORT_SYMBOL(scsi_rescan_device);
1561
__scsi_scan_target(struct device * parent,unsigned int channel,unsigned int id,unsigned int lun,int rescan)1562 static void __scsi_scan_target(struct device *parent, unsigned int channel,
1563 unsigned int id, unsigned int lun, int rescan)
1564 {
1565 struct Scsi_Host *shost = dev_to_shost(parent);
1566 int bflags = 0;
1567 int res;
1568 struct scsi_target *starget;
1569
1570 if (shost->this_id == id)
1571 /*
1572 * Don't scan the host adapter
1573 */
1574 return;
1575
1576 starget = scsi_alloc_target(parent, channel, id);
1577 if (!starget)
1578 return;
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 /* now determine if the target has any children at all
1605 * and if not, nuke it */
1606 scsi_target_reap(starget);
1607
1608 put_device(&starget->dev);
1609 }
1610
1611 /**
1612 * scsi_scan_target - scan a target id, possibly including all LUNs on the target.
1613 * @parent: host to scan
1614 * @channel: channel to scan
1615 * @id: target id to scan
1616 * @lun: Specific LUN to scan or SCAN_WILD_CARD
1617 * @rescan: passed to LUN scanning routines
1618 *
1619 * Description:
1620 * Scan the target id on @parent, @channel, and @id. Scan at least LUN 0,
1621 * and possibly all LUNs on the target id.
1622 *
1623 * First try a REPORT LUN scan, if that does not scan the target, do a
1624 * sequential scan of LUNs on the target id.
1625 **/
scsi_scan_target(struct device * parent,unsigned int channel,unsigned int id,unsigned int lun,int rescan)1626 void scsi_scan_target(struct device *parent, unsigned int channel,
1627 unsigned int id, unsigned int lun, int rescan)
1628 {
1629 struct Scsi_Host *shost = dev_to_shost(parent);
1630
1631 if (strncmp(scsi_scan_type, "none", 4) == 0)
1632 return;
1633
1634 mutex_lock(&shost->scan_mutex);
1635 if (!shost->async_scan)
1636 scsi_complete_async_scans();
1637
1638 if (scsi_host_scan_allowed(shost))
1639 __scsi_scan_target(parent, channel, id, lun, rescan);
1640 mutex_unlock(&shost->scan_mutex);
1641 }
1642 EXPORT_SYMBOL(scsi_scan_target);
1643
scsi_scan_channel(struct Scsi_Host * shost,unsigned int channel,unsigned int id,unsigned int lun,int rescan)1644 static void scsi_scan_channel(struct Scsi_Host *shost, unsigned int channel,
1645 unsigned int id, unsigned int lun, int rescan)
1646 {
1647 uint order_id;
1648
1649 if (id == SCAN_WILD_CARD)
1650 for (id = 0; id < shost->max_id; ++id) {
1651 /*
1652 * XXX adapter drivers when possible (FCP, iSCSI)
1653 * could modify max_id to match the current max,
1654 * not the absolute max.
1655 *
1656 * XXX add a shost id iterator, so for example,
1657 * the FC ID can be the same as a target id
1658 * without a huge overhead of sparse id's.
1659 */
1660 if (shost->reverse_ordering)
1661 /*
1662 * Scan from high to low id.
1663 */
1664 order_id = shost->max_id - id - 1;
1665 else
1666 order_id = id;
1667 __scsi_scan_target(&shost->shost_gendev, channel,
1668 order_id, lun, rescan);
1669 }
1670 else
1671 __scsi_scan_target(&shost->shost_gendev, channel,
1672 id, lun, rescan);
1673 }
1674
scsi_scan_host_selected(struct Scsi_Host * shost,unsigned int channel,unsigned int id,unsigned int lun,int rescan)1675 int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel,
1676 unsigned int id, unsigned int lun, int rescan)
1677 {
1678 SCSI_LOG_SCAN_BUS(3, shost_printk (KERN_INFO, shost,
1679 "%s: <%u:%u:%u>\n",
1680 __func__, channel, id, lun));
1681
1682 if (((channel != SCAN_WILD_CARD) && (channel > shost->max_channel)) ||
1683 ((id != SCAN_WILD_CARD) && (id >= shost->max_id)) ||
1684 ((lun != SCAN_WILD_CARD) && (lun > shost->max_lun)))
1685 return -EINVAL;
1686
1687 mutex_lock(&shost->scan_mutex);
1688 if (!shost->async_scan)
1689 scsi_complete_async_scans();
1690
1691 if (scsi_host_scan_allowed(shost)) {
1692 if (channel == SCAN_WILD_CARD)
1693 for (channel = 0; channel <= shost->max_channel;
1694 channel++)
1695 scsi_scan_channel(shost, channel, id, lun,
1696 rescan);
1697 else
1698 scsi_scan_channel(shost, channel, id, lun, rescan);
1699 }
1700 mutex_unlock(&shost->scan_mutex);
1701
1702 return 0;
1703 }
1704
scsi_sysfs_add_devices(struct Scsi_Host * shost)1705 static void scsi_sysfs_add_devices(struct Scsi_Host *shost)
1706 {
1707 struct scsi_device *sdev;
1708 shost_for_each_device(sdev, shost) {
1709 if (!scsi_host_scan_allowed(shost) ||
1710 scsi_sysfs_add_sdev(sdev) != 0)
1711 scsi_destroy_sdev(sdev);
1712 }
1713 }
1714
1715 /**
1716 * scsi_prep_async_scan - prepare for an async scan
1717 * @shost: the host which will be scanned
1718 * Returns: a cookie to be passed to scsi_finish_async_scan()
1719 *
1720 * Tells the midlayer this host is going to do an asynchronous scan.
1721 * It reserves the host's position in the scanning list and ensures
1722 * that other asynchronous scans started after this one won't affect the
1723 * ordering of the discovered devices.
1724 */
scsi_prep_async_scan(struct Scsi_Host * shost)1725 static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost)
1726 {
1727 struct async_scan_data *data;
1728 unsigned long flags;
1729
1730 if (strncmp(scsi_scan_type, "sync", 4) == 0)
1731 return NULL;
1732
1733 if (shost->async_scan) {
1734 printk("%s called twice for host %d", __func__,
1735 shost->host_no);
1736 dump_stack();
1737 return NULL;
1738 }
1739
1740 data = kmalloc(sizeof(*data), GFP_KERNEL);
1741 if (!data)
1742 goto err;
1743 data->shost = scsi_host_get(shost);
1744 if (!data->shost)
1745 goto err;
1746 init_completion(&data->prev_finished);
1747
1748 mutex_lock(&shost->scan_mutex);
1749 spin_lock_irqsave(shost->host_lock, flags);
1750 shost->async_scan = 1;
1751 spin_unlock_irqrestore(shost->host_lock, flags);
1752 mutex_unlock(&shost->scan_mutex);
1753
1754 spin_lock(&async_scan_lock);
1755 if (list_empty(&scanning_hosts))
1756 complete(&data->prev_finished);
1757 list_add_tail(&data->list, &scanning_hosts);
1758 spin_unlock(&async_scan_lock);
1759
1760 return data;
1761
1762 err:
1763 kfree(data);
1764 return NULL;
1765 }
1766
1767 /**
1768 * scsi_finish_async_scan - asynchronous scan has finished
1769 * @data: cookie returned from earlier call to scsi_prep_async_scan()
1770 *
1771 * All the devices currently attached to this host have been found.
1772 * This function announces all the devices it has found to the rest
1773 * of the system.
1774 */
scsi_finish_async_scan(struct async_scan_data * data)1775 static void scsi_finish_async_scan(struct async_scan_data *data)
1776 {
1777 struct Scsi_Host *shost;
1778 unsigned long flags;
1779
1780 if (!data)
1781 return;
1782
1783 shost = data->shost;
1784
1785 mutex_lock(&shost->scan_mutex);
1786
1787 if (!shost->async_scan) {
1788 printk("%s called twice for host %d", __func__,
1789 shost->host_no);
1790 dump_stack();
1791 mutex_unlock(&shost->scan_mutex);
1792 return;
1793 }
1794
1795 wait_for_completion(&data->prev_finished);
1796
1797 scsi_sysfs_add_devices(shost);
1798
1799 spin_lock_irqsave(shost->host_lock, flags);
1800 shost->async_scan = 0;
1801 spin_unlock_irqrestore(shost->host_lock, flags);
1802
1803 mutex_unlock(&shost->scan_mutex);
1804
1805 spin_lock(&async_scan_lock);
1806 list_del(&data->list);
1807 if (!list_empty(&scanning_hosts)) {
1808 struct async_scan_data *next = list_entry(scanning_hosts.next,
1809 struct async_scan_data, list);
1810 complete(&next->prev_finished);
1811 }
1812 spin_unlock(&async_scan_lock);
1813
1814 scsi_host_put(shost);
1815 kfree(data);
1816 }
1817
do_scsi_scan_host(struct Scsi_Host * shost)1818 static void do_scsi_scan_host(struct Scsi_Host *shost)
1819 {
1820 if (shost->hostt->scan_finished) {
1821 unsigned long start = jiffies;
1822 if (shost->hostt->scan_start)
1823 shost->hostt->scan_start(shost);
1824
1825 while (!shost->hostt->scan_finished(shost, jiffies - start))
1826 msleep(10);
1827 } else {
1828 scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD,
1829 SCAN_WILD_CARD, 0);
1830 }
1831 }
1832
do_scan_async(void * _data)1833 static int do_scan_async(void *_data)
1834 {
1835 struct async_scan_data *data = _data;
1836 do_scsi_scan_host(data->shost);
1837 scsi_finish_async_scan(data);
1838 return 0;
1839 }
1840
1841 /**
1842 * scsi_scan_host - scan the given adapter
1843 * @shost: adapter to scan
1844 **/
scsi_scan_host(struct Scsi_Host * shost)1845 void scsi_scan_host(struct Scsi_Host *shost)
1846 {
1847 struct task_struct *p;
1848 struct async_scan_data *data;
1849
1850 if (strncmp(scsi_scan_type, "none", 4) == 0)
1851 return;
1852
1853 data = scsi_prep_async_scan(shost);
1854 if (!data) {
1855 do_scsi_scan_host(shost);
1856 return;
1857 }
1858
1859 p = kthread_run(do_scan_async, data, "scsi_scan_%d", shost->host_no);
1860 if (IS_ERR(p))
1861 do_scan_async(data);
1862 }
1863 EXPORT_SYMBOL(scsi_scan_host);
1864
scsi_forget_host(struct Scsi_Host * shost)1865 void scsi_forget_host(struct Scsi_Host *shost)
1866 {
1867 struct scsi_device *sdev;
1868 unsigned long flags;
1869
1870 restart:
1871 spin_lock_irqsave(shost->host_lock, flags);
1872 list_for_each_entry(sdev, &shost->__devices, siblings) {
1873 if (sdev->sdev_state == SDEV_DEL)
1874 continue;
1875 spin_unlock_irqrestore(shost->host_lock, flags);
1876 __scsi_remove_device(sdev);
1877 goto restart;
1878 }
1879 spin_unlock_irqrestore(shost->host_lock, flags);
1880 }
1881
1882 /*
1883 * Function: scsi_get_host_dev()
1884 *
1885 * Purpose: Create a scsi_device that points to the host adapter itself.
1886 *
1887 * Arguments: SHpnt - Host that needs a scsi_device
1888 *
1889 * Lock status: None assumed.
1890 *
1891 * Returns: The scsi_device or NULL
1892 *
1893 * Notes:
1894 * Attach a single scsi_device to the Scsi_Host - this should
1895 * be made to look like a "pseudo-device" that points to the
1896 * HA itself.
1897 *
1898 * Note - this device is not accessible from any high-level
1899 * drivers (including generics), which is probably not
1900 * optimal. We can add hooks later to attach
1901 */
scsi_get_host_dev(struct Scsi_Host * shost)1902 struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost)
1903 {
1904 struct scsi_device *sdev = NULL;
1905 struct scsi_target *starget;
1906
1907 mutex_lock(&shost->scan_mutex);
1908 if (!scsi_host_scan_allowed(shost))
1909 goto out;
1910 starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id);
1911 if (!starget)
1912 goto out;
1913
1914 sdev = scsi_alloc_sdev(starget, 0, NULL);
1915 if (sdev) {
1916 sdev->sdev_gendev.parent = get_device(&starget->dev);
1917 sdev->borken = 0;
1918 } else
1919 scsi_target_reap(starget);
1920 put_device(&starget->dev);
1921 out:
1922 mutex_unlock(&shost->scan_mutex);
1923 return sdev;
1924 }
1925 EXPORT_SYMBOL(scsi_get_host_dev);
1926
1927 /*
1928 * Function: scsi_free_host_dev()
1929 *
1930 * Purpose: Free a scsi_device that points to the host adapter itself.
1931 *
1932 * Arguments: SHpnt - Host that needs a scsi_device
1933 *
1934 * Lock status: None assumed.
1935 *
1936 * Returns: Nothing
1937 *
1938 * Notes:
1939 */
scsi_free_host_dev(struct scsi_device * sdev)1940 void scsi_free_host_dev(struct scsi_device *sdev)
1941 {
1942 BUG_ON(sdev->id != sdev->host->this_id);
1943
1944 scsi_destroy_sdev(sdev);
1945 }
1946 EXPORT_SYMBOL(scsi_free_host_dev);
1947
1948