xref: /openbmc/linux/drivers/scsi/scsi_sysfs.c (revision 407e7517)
1 /*
2  * scsi_sysfs.c
3  *
4  * SCSI sysfs interface routines.
5  *
6  * Created to pull SCSI mid layer sysfs routines into one file.
7  */
8 
9 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/init.h>
12 #include <linux/blkdev.h>
13 #include <linux/device.h>
14 #include <linux/pm_runtime.h>
15 
16 #include <scsi/scsi.h>
17 #include <scsi/scsi_device.h>
18 #include <scsi/scsi_host.h>
19 #include <scsi/scsi_tcq.h>
20 #include <scsi/scsi_dh.h>
21 #include <scsi/scsi_transport.h>
22 #include <scsi/scsi_driver.h>
23 #include <scsi/scsi_devinfo.h>
24 
25 #include "scsi_priv.h"
26 #include "scsi_logging.h"
27 
28 static struct device_type scsi_dev_type;
29 
30 static const struct {
31 	enum scsi_device_state	value;
32 	char			*name;
33 } sdev_states[] = {
34 	{ SDEV_CREATED, "created" },
35 	{ SDEV_RUNNING, "running" },
36 	{ SDEV_CANCEL, "cancel" },
37 	{ SDEV_DEL, "deleted" },
38 	{ SDEV_QUIESCE, "quiesce" },
39 	{ SDEV_OFFLINE,	"offline" },
40 	{ SDEV_TRANSPORT_OFFLINE, "transport-offline" },
41 	{ SDEV_BLOCK,	"blocked" },
42 	{ SDEV_CREATED_BLOCK, "created-blocked" },
43 };
44 
45 const char *scsi_device_state_name(enum scsi_device_state state)
46 {
47 	int i;
48 	char *name = NULL;
49 
50 	for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
51 		if (sdev_states[i].value == state) {
52 			name = sdev_states[i].name;
53 			break;
54 		}
55 	}
56 	return name;
57 }
58 
59 static const struct {
60 	enum scsi_host_state	value;
61 	char			*name;
62 } shost_states[] = {
63 	{ SHOST_CREATED, "created" },
64 	{ SHOST_RUNNING, "running" },
65 	{ SHOST_CANCEL, "cancel" },
66 	{ SHOST_DEL, "deleted" },
67 	{ SHOST_RECOVERY, "recovery" },
68 	{ SHOST_CANCEL_RECOVERY, "cancel/recovery" },
69 	{ SHOST_DEL_RECOVERY, "deleted/recovery", },
70 };
71 const char *scsi_host_state_name(enum scsi_host_state state)
72 {
73 	int i;
74 	char *name = NULL;
75 
76 	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
77 		if (shost_states[i].value == state) {
78 			name = shost_states[i].name;
79 			break;
80 		}
81 	}
82 	return name;
83 }
84 
85 #ifdef CONFIG_SCSI_DH
86 static const struct {
87 	unsigned char	value;
88 	char		*name;
89 } sdev_access_states[] = {
90 	{ SCSI_ACCESS_STATE_OPTIMAL, "active/optimized" },
91 	{ SCSI_ACCESS_STATE_ACTIVE, "active/non-optimized" },
92 	{ SCSI_ACCESS_STATE_STANDBY, "standby" },
93 	{ SCSI_ACCESS_STATE_UNAVAILABLE, "unavailable" },
94 	{ SCSI_ACCESS_STATE_LBA, "lba-dependent" },
95 	{ SCSI_ACCESS_STATE_OFFLINE, "offline" },
96 	{ SCSI_ACCESS_STATE_TRANSITIONING, "transitioning" },
97 };
98 
99 static const char *scsi_access_state_name(unsigned char state)
100 {
101 	int i;
102 	char *name = NULL;
103 
104 	for (i = 0; i < ARRAY_SIZE(sdev_access_states); i++) {
105 		if (sdev_access_states[i].value == state) {
106 			name = sdev_access_states[i].name;
107 			break;
108 		}
109 	}
110 	return name;
111 }
112 #endif
113 
114 static int check_set(unsigned long long *val, char *src)
115 {
116 	char *last;
117 
118 	if (strcmp(src, "-") == 0) {
119 		*val = SCAN_WILD_CARD;
120 	} else {
121 		/*
122 		 * Doesn't check for int overflow
123 		 */
124 		*val = simple_strtoull(src, &last, 0);
125 		if (*last != '\0')
126 			return 1;
127 	}
128 	return 0;
129 }
130 
131 static int scsi_scan(struct Scsi_Host *shost, const char *str)
132 {
133 	char s1[15], s2[15], s3[17], junk;
134 	unsigned long long channel, id, lun;
135 	int res;
136 
137 	res = sscanf(str, "%10s %10s %16s %c", s1, s2, s3, &junk);
138 	if (res != 3)
139 		return -EINVAL;
140 	if (check_set(&channel, s1))
141 		return -EINVAL;
142 	if (check_set(&id, s2))
143 		return -EINVAL;
144 	if (check_set(&lun, s3))
145 		return -EINVAL;
146 	if (shost->transportt->user_scan)
147 		res = shost->transportt->user_scan(shost, channel, id, lun);
148 	else
149 		res = scsi_scan_host_selected(shost, channel, id, lun,
150 					      SCSI_SCAN_MANUAL);
151 	return res;
152 }
153 
154 /*
155  * shost_show_function: macro to create an attr function that can be used to
156  * show a non-bit field.
157  */
158 #define shost_show_function(name, field, format_string)			\
159 static ssize_t								\
160 show_##name (struct device *dev, struct device_attribute *attr, 	\
161 	     char *buf)							\
162 {									\
163 	struct Scsi_Host *shost = class_to_shost(dev);			\
164 	return snprintf (buf, 20, format_string, shost->field);		\
165 }
166 
167 /*
168  * shost_rd_attr: macro to create a function and attribute variable for a
169  * read only field.
170  */
171 #define shost_rd_attr2(name, field, format_string)			\
172 	shost_show_function(name, field, format_string)			\
173 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
174 
175 #define shost_rd_attr(field, format_string) \
176 shost_rd_attr2(field, field, format_string)
177 
178 /*
179  * Create the actual show/store functions and data structures.
180  */
181 
182 static ssize_t
183 store_scan(struct device *dev, struct device_attribute *attr,
184 	   const char *buf, size_t count)
185 {
186 	struct Scsi_Host *shost = class_to_shost(dev);
187 	int res;
188 
189 	res = scsi_scan(shost, buf);
190 	if (res == 0)
191 		res = count;
192 	return res;
193 };
194 static DEVICE_ATTR(scan, S_IWUSR, NULL, store_scan);
195 
196 static ssize_t
197 store_shost_state(struct device *dev, struct device_attribute *attr,
198 		  const char *buf, size_t count)
199 {
200 	int i;
201 	struct Scsi_Host *shost = class_to_shost(dev);
202 	enum scsi_host_state state = 0;
203 
204 	for (i = 0; i < ARRAY_SIZE(shost_states); i++) {
205 		const int len = strlen(shost_states[i].name);
206 		if (strncmp(shost_states[i].name, buf, len) == 0 &&
207 		   buf[len] == '\n') {
208 			state = shost_states[i].value;
209 			break;
210 		}
211 	}
212 	if (!state)
213 		return -EINVAL;
214 
215 	if (scsi_host_set_state(shost, state))
216 		return -EINVAL;
217 	return count;
218 }
219 
220 static ssize_t
221 show_shost_state(struct device *dev, struct device_attribute *attr, char *buf)
222 {
223 	struct Scsi_Host *shost = class_to_shost(dev);
224 	const char *name = scsi_host_state_name(shost->shost_state);
225 
226 	if (!name)
227 		return -EINVAL;
228 
229 	return snprintf(buf, 20, "%s\n", name);
230 }
231 
232 /* DEVICE_ATTR(state) clashes with dev_attr_state for sdev */
233 static struct device_attribute dev_attr_hstate =
234 	__ATTR(state, S_IRUGO | S_IWUSR, show_shost_state, store_shost_state);
235 
236 static ssize_t
237 show_shost_mode(unsigned int mode, char *buf)
238 {
239 	ssize_t len = 0;
240 
241 	if (mode & MODE_INITIATOR)
242 		len = sprintf(buf, "%s", "Initiator");
243 
244 	if (mode & MODE_TARGET)
245 		len += sprintf(buf + len, "%s%s", len ? ", " : "", "Target");
246 
247 	len += sprintf(buf + len, "\n");
248 
249 	return len;
250 }
251 
252 static ssize_t
253 show_shost_supported_mode(struct device *dev, struct device_attribute *attr,
254 			  char *buf)
255 {
256 	struct Scsi_Host *shost = class_to_shost(dev);
257 	unsigned int supported_mode = shost->hostt->supported_mode;
258 
259 	if (supported_mode == MODE_UNKNOWN)
260 		/* by default this should be initiator */
261 		supported_mode = MODE_INITIATOR;
262 
263 	return show_shost_mode(supported_mode, buf);
264 }
265 
266 static DEVICE_ATTR(supported_mode, S_IRUGO | S_IWUSR, show_shost_supported_mode, NULL);
267 
268 static ssize_t
269 show_shost_active_mode(struct device *dev,
270 		       struct device_attribute *attr, char *buf)
271 {
272 	struct Scsi_Host *shost = class_to_shost(dev);
273 
274 	if (shost->active_mode == MODE_UNKNOWN)
275 		return snprintf(buf, 20, "unknown\n");
276 	else
277 		return show_shost_mode(shost->active_mode, buf);
278 }
279 
280 static DEVICE_ATTR(active_mode, S_IRUGO | S_IWUSR, show_shost_active_mode, NULL);
281 
282 static int check_reset_type(const char *str)
283 {
284 	if (sysfs_streq(str, "adapter"))
285 		return SCSI_ADAPTER_RESET;
286 	else if (sysfs_streq(str, "firmware"))
287 		return SCSI_FIRMWARE_RESET;
288 	else
289 		return 0;
290 }
291 
292 static ssize_t
293 store_host_reset(struct device *dev, struct device_attribute *attr,
294 		const char *buf, size_t count)
295 {
296 	struct Scsi_Host *shost = class_to_shost(dev);
297 	struct scsi_host_template *sht = shost->hostt;
298 	int ret = -EINVAL;
299 	int type;
300 
301 	type = check_reset_type(buf);
302 	if (!type)
303 		goto exit_store_host_reset;
304 
305 	if (sht->host_reset)
306 		ret = sht->host_reset(shost, type);
307 	else
308 		ret = -EOPNOTSUPP;
309 
310 exit_store_host_reset:
311 	if (ret == 0)
312 		ret = count;
313 	return ret;
314 }
315 
316 static DEVICE_ATTR(host_reset, S_IWUSR, NULL, store_host_reset);
317 
318 static ssize_t
319 show_shost_eh_deadline(struct device *dev,
320 		      struct device_attribute *attr, char *buf)
321 {
322 	struct Scsi_Host *shost = class_to_shost(dev);
323 
324 	if (shost->eh_deadline == -1)
325 		return snprintf(buf, strlen("off") + 2, "off\n");
326 	return sprintf(buf, "%u\n", shost->eh_deadline / HZ);
327 }
328 
329 static ssize_t
330 store_shost_eh_deadline(struct device *dev, struct device_attribute *attr,
331 		const char *buf, size_t count)
332 {
333 	struct Scsi_Host *shost = class_to_shost(dev);
334 	int ret = -EINVAL;
335 	unsigned long deadline, flags;
336 
337 	if (shost->transportt &&
338 	    (shost->transportt->eh_strategy_handler ||
339 	     !shost->hostt->eh_host_reset_handler))
340 		return ret;
341 
342 	if (!strncmp(buf, "off", strlen("off")))
343 		deadline = -1;
344 	else {
345 		ret = kstrtoul(buf, 10, &deadline);
346 		if (ret)
347 			return ret;
348 		if (deadline * HZ > UINT_MAX)
349 			return -EINVAL;
350 	}
351 
352 	spin_lock_irqsave(shost->host_lock, flags);
353 	if (scsi_host_in_recovery(shost))
354 		ret = -EBUSY;
355 	else {
356 		if (deadline == -1)
357 			shost->eh_deadline = -1;
358 		else
359 			shost->eh_deadline = deadline * HZ;
360 
361 		ret = count;
362 	}
363 	spin_unlock_irqrestore(shost->host_lock, flags);
364 
365 	return ret;
366 }
367 
368 static DEVICE_ATTR(eh_deadline, S_IRUGO | S_IWUSR, show_shost_eh_deadline, store_shost_eh_deadline);
369 
370 shost_rd_attr(use_blk_mq, "%d\n");
371 shost_rd_attr(unique_id, "%u\n");
372 shost_rd_attr(cmd_per_lun, "%hd\n");
373 shost_rd_attr(can_queue, "%hd\n");
374 shost_rd_attr(sg_tablesize, "%hu\n");
375 shost_rd_attr(sg_prot_tablesize, "%hu\n");
376 shost_rd_attr(unchecked_isa_dma, "%d\n");
377 shost_rd_attr(prot_capabilities, "%u\n");
378 shost_rd_attr(prot_guard_type, "%hd\n");
379 shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");
380 
381 static ssize_t
382 show_host_busy(struct device *dev, struct device_attribute *attr, char *buf)
383 {
384 	struct Scsi_Host *shost = class_to_shost(dev);
385 	return snprintf(buf, 20, "%d\n", atomic_read(&shost->host_busy));
386 }
387 static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);
388 
389 static struct attribute *scsi_sysfs_shost_attrs[] = {
390 	&dev_attr_use_blk_mq.attr,
391 	&dev_attr_unique_id.attr,
392 	&dev_attr_host_busy.attr,
393 	&dev_attr_cmd_per_lun.attr,
394 	&dev_attr_can_queue.attr,
395 	&dev_attr_sg_tablesize.attr,
396 	&dev_attr_sg_prot_tablesize.attr,
397 	&dev_attr_unchecked_isa_dma.attr,
398 	&dev_attr_proc_name.attr,
399 	&dev_attr_scan.attr,
400 	&dev_attr_hstate.attr,
401 	&dev_attr_supported_mode.attr,
402 	&dev_attr_active_mode.attr,
403 	&dev_attr_prot_capabilities.attr,
404 	&dev_attr_prot_guard_type.attr,
405 	&dev_attr_host_reset.attr,
406 	&dev_attr_eh_deadline.attr,
407 	NULL
408 };
409 
410 static struct attribute_group scsi_shost_attr_group = {
411 	.attrs =	scsi_sysfs_shost_attrs,
412 };
413 
414 const struct attribute_group *scsi_sysfs_shost_attr_groups[] = {
415 	&scsi_shost_attr_group,
416 	NULL
417 };
418 
419 static void scsi_device_cls_release(struct device *class_dev)
420 {
421 	struct scsi_device *sdev;
422 
423 	sdev = class_to_sdev(class_dev);
424 	put_device(&sdev->sdev_gendev);
425 }
426 
427 static void scsi_device_dev_release_usercontext(struct work_struct *work)
428 {
429 	struct scsi_device *sdev;
430 	struct device *parent;
431 	struct list_head *this, *tmp;
432 	struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
433 	unsigned long flags;
434 
435 	sdev = container_of(work, struct scsi_device, ew.work);
436 
437 	scsi_dh_release_device(sdev);
438 
439 	parent = sdev->sdev_gendev.parent;
440 
441 	spin_lock_irqsave(sdev->host->host_lock, flags);
442 	list_del(&sdev->siblings);
443 	list_del(&sdev->same_target_siblings);
444 	list_del(&sdev->starved_entry);
445 	spin_unlock_irqrestore(sdev->host->host_lock, flags);
446 
447 	cancel_work_sync(&sdev->event_work);
448 
449 	list_for_each_safe(this, tmp, &sdev->event_list) {
450 		struct scsi_event *evt;
451 
452 		evt = list_entry(this, struct scsi_event, node);
453 		list_del(&evt->node);
454 		kfree(evt);
455 	}
456 
457 	blk_put_queue(sdev->request_queue);
458 	/* NULL queue means the device can't be used */
459 	sdev->request_queue = NULL;
460 
461 	mutex_lock(&sdev->inquiry_mutex);
462 	rcu_swap_protected(sdev->vpd_pg80, vpd_pg80,
463 			   lockdep_is_held(&sdev->inquiry_mutex));
464 	rcu_swap_protected(sdev->vpd_pg83, vpd_pg83,
465 			   lockdep_is_held(&sdev->inquiry_mutex));
466 	mutex_unlock(&sdev->inquiry_mutex);
467 
468 	if (vpd_pg83)
469 		kfree_rcu(vpd_pg83, rcu);
470 	if (vpd_pg80)
471 		kfree_rcu(vpd_pg80, rcu);
472 	kfree(sdev->inquiry);
473 	kfree(sdev);
474 
475 	if (parent)
476 		put_device(parent);
477 }
478 
479 static void scsi_device_dev_release(struct device *dev)
480 {
481 	struct scsi_device *sdp = to_scsi_device(dev);
482 	execute_in_process_context(scsi_device_dev_release_usercontext,
483 				   &sdp->ew);
484 }
485 
486 static struct class sdev_class = {
487 	.name		= "scsi_device",
488 	.dev_release	= scsi_device_cls_release,
489 };
490 
491 /* all probing is done in the individual ->probe routines */
492 static int scsi_bus_match(struct device *dev, struct device_driver *gendrv)
493 {
494 	struct scsi_device *sdp;
495 
496 	if (dev->type != &scsi_dev_type)
497 		return 0;
498 
499 	sdp = to_scsi_device(dev);
500 	if (sdp->no_uld_attach)
501 		return 0;
502 	return (sdp->inq_periph_qual == SCSI_INQ_PQ_CON)? 1: 0;
503 }
504 
505 static int scsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env)
506 {
507 	struct scsi_device *sdev;
508 
509 	if (dev->type != &scsi_dev_type)
510 		return 0;
511 
512 	sdev = to_scsi_device(dev);
513 
514 	add_uevent_var(env, "MODALIAS=" SCSI_DEVICE_MODALIAS_FMT, sdev->type);
515 	return 0;
516 }
517 
518 struct bus_type scsi_bus_type = {
519         .name		= "scsi",
520         .match		= scsi_bus_match,
521 	.uevent		= scsi_bus_uevent,
522 #ifdef CONFIG_PM
523 	.pm		= &scsi_bus_pm_ops,
524 #endif
525 };
526 EXPORT_SYMBOL_GPL(scsi_bus_type);
527 
528 int scsi_sysfs_register(void)
529 {
530 	int error;
531 
532 	error = bus_register(&scsi_bus_type);
533 	if (!error) {
534 		error = class_register(&sdev_class);
535 		if (error)
536 			bus_unregister(&scsi_bus_type);
537 	}
538 
539 	return error;
540 }
541 
542 void scsi_sysfs_unregister(void)
543 {
544 	class_unregister(&sdev_class);
545 	bus_unregister(&scsi_bus_type);
546 }
547 
548 /*
549  * sdev_show_function: macro to create an attr function that can be used to
550  * show a non-bit field.
551  */
552 #define sdev_show_function(field, format_string)				\
553 static ssize_t								\
554 sdev_show_##field (struct device *dev, struct device_attribute *attr,	\
555 		   char *buf)						\
556 {									\
557 	struct scsi_device *sdev;					\
558 	sdev = to_scsi_device(dev);					\
559 	return snprintf (buf, 20, format_string, sdev->field);		\
560 }									\
561 
562 /*
563  * sdev_rd_attr: macro to create a function and attribute variable for a
564  * read only field.
565  */
566 #define sdev_rd_attr(field, format_string)				\
567 	sdev_show_function(field, format_string)			\
568 static DEVICE_ATTR(field, S_IRUGO, sdev_show_##field, NULL);
569 
570 
571 /*
572  * sdev_rw_attr: create a function and attribute variable for a
573  * read/write field.
574  */
575 #define sdev_rw_attr(field, format_string)				\
576 	sdev_show_function(field, format_string)				\
577 									\
578 static ssize_t								\
579 sdev_store_##field (struct device *dev, struct device_attribute *attr,	\
580 		    const char *buf, size_t count)			\
581 {									\
582 	struct scsi_device *sdev;					\
583 	sdev = to_scsi_device(dev);					\
584 	sscanf (buf, format_string, &sdev->field);			\
585 	return count;							\
586 }									\
587 static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);
588 
589 /* Currently we don't export bit fields, but we might in future,
590  * so leave this code in */
591 #if 0
592 /*
593  * sdev_rd_attr: create a function and attribute variable for a
594  * read/write bit field.
595  */
596 #define sdev_rw_attr_bit(field)						\
597 	sdev_show_function(field, "%d\n")					\
598 									\
599 static ssize_t								\
600 sdev_store_##field (struct device *dev, struct device_attribute *attr,	\
601 		    const char *buf, size_t count)			\
602 {									\
603 	int ret;							\
604 	struct scsi_device *sdev;					\
605 	ret = scsi_sdev_check_buf_bit(buf);				\
606 	if (ret >= 0)	{						\
607 		sdev = to_scsi_device(dev);				\
608 		sdev->field = ret;					\
609 		ret = count;						\
610 	}								\
611 	return ret;							\
612 }									\
613 static DEVICE_ATTR(field, S_IRUGO | S_IWUSR, sdev_show_##field, sdev_store_##field);
614 
615 /*
616  * scsi_sdev_check_buf_bit: return 0 if buf is "0", return 1 if buf is "1",
617  * else return -EINVAL.
618  */
619 static int scsi_sdev_check_buf_bit(const char *buf)
620 {
621 	if ((buf[1] == '\0') || ((buf[1] == '\n') && (buf[2] == '\0'))) {
622 		if (buf[0] == '1')
623 			return 1;
624 		else if (buf[0] == '0')
625 			return 0;
626 		else
627 			return -EINVAL;
628 	} else
629 		return -EINVAL;
630 }
631 #endif
632 /*
633  * Create the actual show/store functions and data structures.
634  */
635 sdev_rd_attr (type, "%d\n");
636 sdev_rd_attr (scsi_level, "%d\n");
637 sdev_rd_attr (vendor, "%.8s\n");
638 sdev_rd_attr (model, "%.16s\n");
639 sdev_rd_attr (rev, "%.4s\n");
640 
641 static ssize_t
642 sdev_show_device_busy(struct device *dev, struct device_attribute *attr,
643 		char *buf)
644 {
645 	struct scsi_device *sdev = to_scsi_device(dev);
646 	return snprintf(buf, 20, "%d\n", atomic_read(&sdev->device_busy));
647 }
648 static DEVICE_ATTR(device_busy, S_IRUGO, sdev_show_device_busy, NULL);
649 
650 static ssize_t
651 sdev_show_device_blocked(struct device *dev, struct device_attribute *attr,
652 		char *buf)
653 {
654 	struct scsi_device *sdev = to_scsi_device(dev);
655 	return snprintf(buf, 20, "%d\n", atomic_read(&sdev->device_blocked));
656 }
657 static DEVICE_ATTR(device_blocked, S_IRUGO, sdev_show_device_blocked, NULL);
658 
659 /*
660  * TODO: can we make these symlinks to the block layer ones?
661  */
662 static ssize_t
663 sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
664 {
665 	struct scsi_device *sdev;
666 	sdev = to_scsi_device(dev);
667 	return snprintf(buf, 20, "%d\n", sdev->request_queue->rq_timeout / HZ);
668 }
669 
670 static ssize_t
671 sdev_store_timeout (struct device *dev, struct device_attribute *attr,
672 		    const char *buf, size_t count)
673 {
674 	struct scsi_device *sdev;
675 	int timeout;
676 	sdev = to_scsi_device(dev);
677 	sscanf (buf, "%d\n", &timeout);
678 	blk_queue_rq_timeout(sdev->request_queue, timeout * HZ);
679 	return count;
680 }
681 static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout);
682 
683 static ssize_t
684 sdev_show_eh_timeout(struct device *dev, struct device_attribute *attr, char *buf)
685 {
686 	struct scsi_device *sdev;
687 	sdev = to_scsi_device(dev);
688 	return snprintf(buf, 20, "%u\n", sdev->eh_timeout / HZ);
689 }
690 
691 static ssize_t
692 sdev_store_eh_timeout(struct device *dev, struct device_attribute *attr,
693 		    const char *buf, size_t count)
694 {
695 	struct scsi_device *sdev;
696 	unsigned int eh_timeout;
697 	int err;
698 
699 	if (!capable(CAP_SYS_ADMIN))
700 		return -EACCES;
701 
702 	sdev = to_scsi_device(dev);
703 	err = kstrtouint(buf, 10, &eh_timeout);
704 	if (err)
705 		return err;
706 	sdev->eh_timeout = eh_timeout * HZ;
707 
708 	return count;
709 }
710 static DEVICE_ATTR(eh_timeout, S_IRUGO | S_IWUSR, sdev_show_eh_timeout, sdev_store_eh_timeout);
711 
712 static ssize_t
713 store_rescan_field (struct device *dev, struct device_attribute *attr,
714 		    const char *buf, size_t count)
715 {
716 	scsi_rescan_device(dev);
717 	return count;
718 }
719 static DEVICE_ATTR(rescan, S_IWUSR, NULL, store_rescan_field);
720 
721 static ssize_t
722 sdev_store_delete(struct device *dev, struct device_attribute *attr,
723 		  const char *buf, size_t count)
724 {
725 	if (device_remove_file_self(dev, attr))
726 		scsi_remove_device(to_scsi_device(dev));
727 	return count;
728 };
729 static DEVICE_ATTR(delete, S_IWUSR, NULL, sdev_store_delete);
730 
731 static ssize_t
732 store_state_field(struct device *dev, struct device_attribute *attr,
733 		  const char *buf, size_t count)
734 {
735 	int i, ret;
736 	struct scsi_device *sdev = to_scsi_device(dev);
737 	enum scsi_device_state state = 0;
738 
739 	for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
740 		const int len = strlen(sdev_states[i].name);
741 		if (strncmp(sdev_states[i].name, buf, len) == 0 &&
742 		   buf[len] == '\n') {
743 			state = sdev_states[i].value;
744 			break;
745 		}
746 	}
747 	if (!state)
748 		return -EINVAL;
749 
750 	mutex_lock(&sdev->state_mutex);
751 	ret = scsi_device_set_state(sdev, state);
752 	mutex_unlock(&sdev->state_mutex);
753 
754 	return ret == 0 ? count : -EINVAL;
755 }
756 
757 static ssize_t
758 show_state_field(struct device *dev, struct device_attribute *attr, char *buf)
759 {
760 	struct scsi_device *sdev = to_scsi_device(dev);
761 	const char *name = scsi_device_state_name(sdev->sdev_state);
762 
763 	if (!name)
764 		return -EINVAL;
765 
766 	return snprintf(buf, 20, "%s\n", name);
767 }
768 
769 static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_state_field, store_state_field);
770 
771 static ssize_t
772 show_queue_type_field(struct device *dev, struct device_attribute *attr,
773 		      char *buf)
774 {
775 	struct scsi_device *sdev = to_scsi_device(dev);
776 	const char *name = "none";
777 
778 	if (sdev->simple_tags)
779 		name = "simple";
780 
781 	return snprintf(buf, 20, "%s\n", name);
782 }
783 
784 static ssize_t
785 store_queue_type_field(struct device *dev, struct device_attribute *attr,
786 		       const char *buf, size_t count)
787 {
788 	struct scsi_device *sdev = to_scsi_device(dev);
789 
790 	if (!sdev->tagged_supported)
791 		return -EINVAL;
792 
793 	sdev_printk(KERN_INFO, sdev,
794 		    "ignoring write to deprecated queue_type attribute");
795 	return count;
796 }
797 
798 static DEVICE_ATTR(queue_type, S_IRUGO | S_IWUSR, show_queue_type_field,
799 		   store_queue_type_field);
800 
801 #define sdev_vpd_pg_attr(_page)						\
802 static ssize_t							\
803 show_vpd_##_page(struct file *filp, struct kobject *kobj,	\
804 		 struct bin_attribute *bin_attr,			\
805 		 char *buf, loff_t off, size_t count)			\
806 {									\
807 	struct device *dev = container_of(kobj, struct device, kobj);	\
808 	struct scsi_device *sdev = to_scsi_device(dev);			\
809 	struct scsi_vpd *vpd_page;					\
810 	int ret = -EINVAL;						\
811 									\
812 	rcu_read_lock();						\
813 	vpd_page = rcu_dereference(sdev->vpd_##_page);			\
814 	if (vpd_page)							\
815 		ret = memory_read_from_buffer(buf, count, &off,		\
816 				vpd_page->data, vpd_page->len);		\
817 	rcu_read_unlock();						\
818 	return ret;							\
819 }									\
820 static struct bin_attribute dev_attr_vpd_##_page = {		\
821 	.attr =	{.name = __stringify(vpd_##_page), .mode = S_IRUGO },	\
822 	.size = 0,							\
823 	.read = show_vpd_##_page,					\
824 };
825 
826 sdev_vpd_pg_attr(pg83);
827 sdev_vpd_pg_attr(pg80);
828 
829 static ssize_t show_inquiry(struct file *filep, struct kobject *kobj,
830 			    struct bin_attribute *bin_attr,
831 			    char *buf, loff_t off, size_t count)
832 {
833 	struct device *dev = container_of(kobj, struct device, kobj);
834 	struct scsi_device *sdev = to_scsi_device(dev);
835 
836 	if (!sdev->inquiry)
837 		return -EINVAL;
838 
839 	return memory_read_from_buffer(buf, count, &off, sdev->inquiry,
840 				       sdev->inquiry_len);
841 }
842 
843 static struct bin_attribute dev_attr_inquiry = {
844 	.attr = {
845 		.name = "inquiry",
846 		.mode = S_IRUGO,
847 	},
848 	.size = 0,
849 	.read = show_inquiry,
850 };
851 
852 static ssize_t
853 show_iostat_counterbits(struct device *dev, struct device_attribute *attr,
854 			char *buf)
855 {
856 	return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
857 }
858 
859 static DEVICE_ATTR(iocounterbits, S_IRUGO, show_iostat_counterbits, NULL);
860 
861 #define show_sdev_iostat(field)						\
862 static ssize_t								\
863 show_iostat_##field(struct device *dev, struct device_attribute *attr,	\
864 		    char *buf)						\
865 {									\
866 	struct scsi_device *sdev = to_scsi_device(dev);			\
867 	unsigned long long count = atomic_read(&sdev->field);		\
868 	return snprintf(buf, 20, "0x%llx\n", count);			\
869 }									\
870 static DEVICE_ATTR(field, S_IRUGO, show_iostat_##field, NULL)
871 
872 show_sdev_iostat(iorequest_cnt);
873 show_sdev_iostat(iodone_cnt);
874 show_sdev_iostat(ioerr_cnt);
875 
876 static ssize_t
877 sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
878 {
879 	struct scsi_device *sdev;
880 	sdev = to_scsi_device(dev);
881 	return snprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
882 }
883 static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);
884 
885 #define DECLARE_EVT_SHOW(name, Cap_name)				\
886 static ssize_t								\
887 sdev_show_evt_##name(struct device *dev, struct device_attribute *attr,	\
888 		     char *buf)						\
889 {									\
890 	struct scsi_device *sdev = to_scsi_device(dev);			\
891 	int val = test_bit(SDEV_EVT_##Cap_name, sdev->supported_events);\
892 	return snprintf(buf, 20, "%d\n", val);				\
893 }
894 
895 #define DECLARE_EVT_STORE(name, Cap_name)				\
896 static ssize_t								\
897 sdev_store_evt_##name(struct device *dev, struct device_attribute *attr,\
898 		      const char *buf, size_t count)			\
899 {									\
900 	struct scsi_device *sdev = to_scsi_device(dev);			\
901 	int val = simple_strtoul(buf, NULL, 0);				\
902 	if (val == 0)							\
903 		clear_bit(SDEV_EVT_##Cap_name, sdev->supported_events);	\
904 	else if (val == 1)						\
905 		set_bit(SDEV_EVT_##Cap_name, sdev->supported_events);	\
906 	else								\
907 		return -EINVAL;						\
908 	return count;							\
909 }
910 
911 #define DECLARE_EVT(name, Cap_name)					\
912 	DECLARE_EVT_SHOW(name, Cap_name)				\
913 	DECLARE_EVT_STORE(name, Cap_name)				\
914 	static DEVICE_ATTR(evt_##name, S_IRUGO, sdev_show_evt_##name,	\
915 			   sdev_store_evt_##name);
916 #define REF_EVT(name) &dev_attr_evt_##name.attr
917 
918 DECLARE_EVT(media_change, MEDIA_CHANGE)
919 DECLARE_EVT(inquiry_change_reported, INQUIRY_CHANGE_REPORTED)
920 DECLARE_EVT(capacity_change_reported, CAPACITY_CHANGE_REPORTED)
921 DECLARE_EVT(soft_threshold_reached, SOFT_THRESHOLD_REACHED_REPORTED)
922 DECLARE_EVT(mode_parameter_change_reported, MODE_PARAMETER_CHANGE_REPORTED)
923 DECLARE_EVT(lun_change_reported, LUN_CHANGE_REPORTED)
924 
925 static ssize_t
926 sdev_store_queue_depth(struct device *dev, struct device_attribute *attr,
927 		       const char *buf, size_t count)
928 {
929 	int depth, retval;
930 	struct scsi_device *sdev = to_scsi_device(dev);
931 	struct scsi_host_template *sht = sdev->host->hostt;
932 
933 	if (!sht->change_queue_depth)
934 		return -EINVAL;
935 
936 	depth = simple_strtoul(buf, NULL, 0);
937 
938 	if (depth < 1 || depth > sdev->host->can_queue)
939 		return -EINVAL;
940 
941 	retval = sht->change_queue_depth(sdev, depth);
942 	if (retval < 0)
943 		return retval;
944 
945 	sdev->max_queue_depth = sdev->queue_depth;
946 
947 	return count;
948 }
949 sdev_show_function(queue_depth, "%d\n");
950 
951 static DEVICE_ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
952 		   sdev_store_queue_depth);
953 
954 static ssize_t
955 sdev_show_wwid(struct device *dev, struct device_attribute *attr,
956 		    char *buf)
957 {
958 	struct scsi_device *sdev = to_scsi_device(dev);
959 	ssize_t count;
960 
961 	count = scsi_vpd_lun_id(sdev, buf, PAGE_SIZE);
962 	if (count > 0) {
963 		buf[count] = '\n';
964 		count++;
965 	}
966 	return count;
967 }
968 static DEVICE_ATTR(wwid, S_IRUGO, sdev_show_wwid, NULL);
969 
970 #define BLIST_FLAG_NAME(name)					\
971 	[ilog2((__force unsigned int)BLIST_##name)] = #name
972 static const char *const sdev_bflags_name[] = {
973 #include "scsi_devinfo_tbl.c"
974 };
975 #undef BLIST_FLAG_NAME
976 
977 static ssize_t
978 sdev_show_blacklist(struct device *dev, struct device_attribute *attr,
979 		    char *buf)
980 {
981 	struct scsi_device *sdev = to_scsi_device(dev);
982 	int i;
983 	ssize_t len = 0;
984 
985 	for (i = 0; i < sizeof(sdev->sdev_bflags) * BITS_PER_BYTE; i++) {
986 		const char *name = NULL;
987 
988 		if (!(sdev->sdev_bflags & (__force blist_flags_t)BIT(i)))
989 			continue;
990 		if (i < ARRAY_SIZE(sdev_bflags_name) && sdev_bflags_name[i])
991 			name = sdev_bflags_name[i];
992 
993 		if (name)
994 			len += snprintf(buf + len, PAGE_SIZE - len,
995 					"%s%s", len ? " " : "", name);
996 		else
997 			len += snprintf(buf + len, PAGE_SIZE - len,
998 					"%sINVALID_BIT(%d)", len ? " " : "", i);
999 	}
1000 	if (len)
1001 		len += snprintf(buf + len, PAGE_SIZE - len, "\n");
1002 	return len;
1003 }
1004 static DEVICE_ATTR(blacklist, S_IRUGO, sdev_show_blacklist, NULL);
1005 
1006 #ifdef CONFIG_SCSI_DH
1007 static ssize_t
1008 sdev_show_dh_state(struct device *dev, struct device_attribute *attr,
1009 		   char *buf)
1010 {
1011 	struct scsi_device *sdev = to_scsi_device(dev);
1012 
1013 	if (!sdev->handler)
1014 		return snprintf(buf, 20, "detached\n");
1015 
1016 	return snprintf(buf, 20, "%s\n", sdev->handler->name);
1017 }
1018 
1019 static ssize_t
1020 sdev_store_dh_state(struct device *dev, struct device_attribute *attr,
1021 		    const char *buf, size_t count)
1022 {
1023 	struct scsi_device *sdev = to_scsi_device(dev);
1024 	int err = -EINVAL;
1025 
1026 	if (sdev->sdev_state == SDEV_CANCEL ||
1027 	    sdev->sdev_state == SDEV_DEL)
1028 		return -ENODEV;
1029 
1030 	if (!sdev->handler) {
1031 		/*
1032 		 * Attach to a device handler
1033 		 */
1034 		err = scsi_dh_attach(sdev->request_queue, buf);
1035 	} else if (!strncmp(buf, "activate", 8)) {
1036 		/*
1037 		 * Activate a device handler
1038 		 */
1039 		if (sdev->handler->activate)
1040 			err = sdev->handler->activate(sdev, NULL, NULL);
1041 		else
1042 			err = 0;
1043 	} else if (!strncmp(buf, "detach", 6)) {
1044 		/*
1045 		 * Detach from a device handler
1046 		 */
1047 		sdev_printk(KERN_WARNING, sdev,
1048 			    "can't detach handler %s.\n",
1049 			    sdev->handler->name);
1050 		err = -EINVAL;
1051 	}
1052 
1053 	return err < 0 ? err : count;
1054 }
1055 
1056 static DEVICE_ATTR(dh_state, S_IRUGO | S_IWUSR, sdev_show_dh_state,
1057 		   sdev_store_dh_state);
1058 
1059 static ssize_t
1060 sdev_show_access_state(struct device *dev,
1061 		       struct device_attribute *attr,
1062 		       char *buf)
1063 {
1064 	struct scsi_device *sdev = to_scsi_device(dev);
1065 	unsigned char access_state;
1066 	const char *access_state_name;
1067 
1068 	if (!sdev->handler)
1069 		return -EINVAL;
1070 
1071 	access_state = (sdev->access_state & SCSI_ACCESS_STATE_MASK);
1072 	access_state_name = scsi_access_state_name(access_state);
1073 
1074 	return sprintf(buf, "%s\n",
1075 		       access_state_name ? access_state_name : "unknown");
1076 }
1077 static DEVICE_ATTR(access_state, S_IRUGO, sdev_show_access_state, NULL);
1078 
1079 static ssize_t
1080 sdev_show_preferred_path(struct device *dev,
1081 			 struct device_attribute *attr,
1082 			 char *buf)
1083 {
1084 	struct scsi_device *sdev = to_scsi_device(dev);
1085 
1086 	if (!sdev->handler)
1087 		return -EINVAL;
1088 
1089 	if (sdev->access_state & SCSI_ACCESS_STATE_PREFERRED)
1090 		return sprintf(buf, "1\n");
1091 	else
1092 		return sprintf(buf, "0\n");
1093 }
1094 static DEVICE_ATTR(preferred_path, S_IRUGO, sdev_show_preferred_path, NULL);
1095 #endif
1096 
1097 static ssize_t
1098 sdev_show_queue_ramp_up_period(struct device *dev,
1099 			       struct device_attribute *attr,
1100 			       char *buf)
1101 {
1102 	struct scsi_device *sdev;
1103 	sdev = to_scsi_device(dev);
1104 	return snprintf(buf, 20, "%u\n",
1105 			jiffies_to_msecs(sdev->queue_ramp_up_period));
1106 }
1107 
1108 static ssize_t
1109 sdev_store_queue_ramp_up_period(struct device *dev,
1110 				struct device_attribute *attr,
1111 				const char *buf, size_t count)
1112 {
1113 	struct scsi_device *sdev = to_scsi_device(dev);
1114 	unsigned int period;
1115 
1116 	if (kstrtouint(buf, 10, &period))
1117 		return -EINVAL;
1118 
1119 	sdev->queue_ramp_up_period = msecs_to_jiffies(period);
1120 	return count;
1121 }
1122 
1123 static DEVICE_ATTR(queue_ramp_up_period, S_IRUGO | S_IWUSR,
1124 		   sdev_show_queue_ramp_up_period,
1125 		   sdev_store_queue_ramp_up_period);
1126 
1127 static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
1128 					 struct attribute *attr, int i)
1129 {
1130 	struct device *dev = container_of(kobj, struct device, kobj);
1131 	struct scsi_device *sdev = to_scsi_device(dev);
1132 
1133 
1134 	if (attr == &dev_attr_queue_depth.attr &&
1135 	    !sdev->host->hostt->change_queue_depth)
1136 		return S_IRUGO;
1137 
1138 	if (attr == &dev_attr_queue_ramp_up_period.attr &&
1139 	    !sdev->host->hostt->change_queue_depth)
1140 		return 0;
1141 
1142 #ifdef CONFIG_SCSI_DH
1143 	if (attr == &dev_attr_access_state.attr &&
1144 	    !sdev->handler)
1145 		return 0;
1146 	if (attr == &dev_attr_preferred_path.attr &&
1147 	    !sdev->handler)
1148 		return 0;
1149 #endif
1150 	return attr->mode;
1151 }
1152 
1153 static umode_t scsi_sdev_bin_attr_is_visible(struct kobject *kobj,
1154 					     struct bin_attribute *attr, int i)
1155 {
1156 	struct device *dev = container_of(kobj, struct device, kobj);
1157 	struct scsi_device *sdev = to_scsi_device(dev);
1158 
1159 
1160 	if (attr == &dev_attr_vpd_pg80 && !sdev->vpd_pg80)
1161 		return 0;
1162 
1163 	if (attr == &dev_attr_vpd_pg83 && !sdev->vpd_pg83)
1164 		return 0;
1165 
1166 	return S_IRUGO;
1167 }
1168 
1169 /* Default template for device attributes.  May NOT be modified */
1170 static struct attribute *scsi_sdev_attrs[] = {
1171 	&dev_attr_device_blocked.attr,
1172 	&dev_attr_type.attr,
1173 	&dev_attr_scsi_level.attr,
1174 	&dev_attr_device_busy.attr,
1175 	&dev_attr_vendor.attr,
1176 	&dev_attr_model.attr,
1177 	&dev_attr_rev.attr,
1178 	&dev_attr_rescan.attr,
1179 	&dev_attr_delete.attr,
1180 	&dev_attr_state.attr,
1181 	&dev_attr_timeout.attr,
1182 	&dev_attr_eh_timeout.attr,
1183 	&dev_attr_iocounterbits.attr,
1184 	&dev_attr_iorequest_cnt.attr,
1185 	&dev_attr_iodone_cnt.attr,
1186 	&dev_attr_ioerr_cnt.attr,
1187 	&dev_attr_modalias.attr,
1188 	&dev_attr_queue_depth.attr,
1189 	&dev_attr_queue_type.attr,
1190 	&dev_attr_wwid.attr,
1191 	&dev_attr_blacklist.attr,
1192 #ifdef CONFIG_SCSI_DH
1193 	&dev_attr_dh_state.attr,
1194 	&dev_attr_access_state.attr,
1195 	&dev_attr_preferred_path.attr,
1196 #endif
1197 	&dev_attr_queue_ramp_up_period.attr,
1198 	REF_EVT(media_change),
1199 	REF_EVT(inquiry_change_reported),
1200 	REF_EVT(capacity_change_reported),
1201 	REF_EVT(soft_threshold_reached),
1202 	REF_EVT(mode_parameter_change_reported),
1203 	REF_EVT(lun_change_reported),
1204 	NULL
1205 };
1206 
1207 static struct bin_attribute *scsi_sdev_bin_attrs[] = {
1208 	&dev_attr_vpd_pg83,
1209 	&dev_attr_vpd_pg80,
1210 	&dev_attr_inquiry,
1211 	NULL
1212 };
1213 static struct attribute_group scsi_sdev_attr_group = {
1214 	.attrs =	scsi_sdev_attrs,
1215 	.bin_attrs =	scsi_sdev_bin_attrs,
1216 	.is_visible =	scsi_sdev_attr_is_visible,
1217 	.is_bin_visible = scsi_sdev_bin_attr_is_visible,
1218 };
1219 
1220 static const struct attribute_group *scsi_sdev_attr_groups[] = {
1221 	&scsi_sdev_attr_group,
1222 	NULL
1223 };
1224 
1225 static int scsi_target_add(struct scsi_target *starget)
1226 {
1227 	int error;
1228 
1229 	if (starget->state != STARGET_CREATED)
1230 		return 0;
1231 
1232 	error = device_add(&starget->dev);
1233 	if (error) {
1234 		dev_err(&starget->dev, "target device_add failed, error %d\n", error);
1235 		return error;
1236 	}
1237 	transport_add_device(&starget->dev);
1238 	starget->state = STARGET_RUNNING;
1239 
1240 	pm_runtime_set_active(&starget->dev);
1241 	pm_runtime_enable(&starget->dev);
1242 	device_enable_async_suspend(&starget->dev);
1243 
1244 	return 0;
1245 }
1246 
1247 /**
1248  * scsi_sysfs_add_sdev - add scsi device to sysfs
1249  * @sdev:	scsi_device to add
1250  *
1251  * Return value:
1252  * 	0 on Success / non-zero on Failure
1253  **/
1254 int scsi_sysfs_add_sdev(struct scsi_device *sdev)
1255 {
1256 	int error, i;
1257 	struct request_queue *rq = sdev->request_queue;
1258 	struct scsi_target *starget = sdev->sdev_target;
1259 
1260 	error = scsi_target_add(starget);
1261 	if (error)
1262 		return error;
1263 
1264 	transport_configure_device(&starget->dev);
1265 
1266 	device_enable_async_suspend(&sdev->sdev_gendev);
1267 	scsi_autopm_get_target(starget);
1268 	pm_runtime_set_active(&sdev->sdev_gendev);
1269 	pm_runtime_forbid(&sdev->sdev_gendev);
1270 	pm_runtime_enable(&sdev->sdev_gendev);
1271 	scsi_autopm_put_target(starget);
1272 
1273 	scsi_autopm_get_device(sdev);
1274 
1275 	scsi_dh_add_device(sdev);
1276 
1277 	error = device_add(&sdev->sdev_gendev);
1278 	if (error) {
1279 		sdev_printk(KERN_INFO, sdev,
1280 				"failed to add device: %d\n", error);
1281 		return error;
1282 	}
1283 
1284 	device_enable_async_suspend(&sdev->sdev_dev);
1285 	error = device_add(&sdev->sdev_dev);
1286 	if (error) {
1287 		sdev_printk(KERN_INFO, sdev,
1288 				"failed to add class device: %d\n", error);
1289 		device_del(&sdev->sdev_gendev);
1290 		return error;
1291 	}
1292 	transport_add_device(&sdev->sdev_gendev);
1293 	sdev->is_visible = 1;
1294 
1295 	error = bsg_register_queue(rq, &sdev->sdev_gendev, NULL, NULL);
1296 
1297 	if (error)
1298 		/* we're treating error on bsg register as non-fatal,
1299 		 * so pretend nothing went wrong */
1300 		sdev_printk(KERN_INFO, sdev,
1301 			    "Failed to register bsg queue, errno=%d\n", error);
1302 
1303 	/* add additional host specific attributes */
1304 	if (sdev->host->hostt->sdev_attrs) {
1305 		for (i = 0; sdev->host->hostt->sdev_attrs[i]; i++) {
1306 			error = device_create_file(&sdev->sdev_gendev,
1307 					sdev->host->hostt->sdev_attrs[i]);
1308 			if (error)
1309 				return error;
1310 		}
1311 	}
1312 
1313 	scsi_autopm_put_device(sdev);
1314 	return error;
1315 }
1316 
1317 void __scsi_remove_device(struct scsi_device *sdev)
1318 {
1319 	struct device *dev = &sdev->sdev_gendev;
1320 	int res;
1321 
1322 	/*
1323 	 * This cleanup path is not reentrant and while it is impossible
1324 	 * to get a new reference with scsi_device_get() someone can still
1325 	 * hold a previously acquired one.
1326 	 */
1327 	if (sdev->sdev_state == SDEV_DEL)
1328 		return;
1329 
1330 	if (sdev->is_visible) {
1331 		/*
1332 		 * If scsi_internal_target_block() is running concurrently,
1333 		 * wait until it has finished before changing the device state.
1334 		 */
1335 		mutex_lock(&sdev->state_mutex);
1336 		/*
1337 		 * If blocked, we go straight to DEL and restart the queue so
1338 		 * any commands issued during driver shutdown (like sync
1339 		 * cache) are errored immediately.
1340 		 */
1341 		res = scsi_device_set_state(sdev, SDEV_CANCEL);
1342 		if (res != 0) {
1343 			res = scsi_device_set_state(sdev, SDEV_DEL);
1344 			if (res == 0)
1345 				scsi_start_queue(sdev);
1346 		}
1347 		mutex_unlock(&sdev->state_mutex);
1348 
1349 		if (res != 0)
1350 			return;
1351 
1352 		bsg_unregister_queue(sdev->request_queue);
1353 		device_unregister(&sdev->sdev_dev);
1354 		transport_remove_device(dev);
1355 		device_del(dev);
1356 	} else
1357 		put_device(&sdev->sdev_dev);
1358 
1359 	/*
1360 	 * Stop accepting new requests and wait until all queuecommand() and
1361 	 * scsi_run_queue() invocations have finished before tearing down the
1362 	 * device.
1363 	 */
1364 	mutex_lock(&sdev->state_mutex);
1365 	scsi_device_set_state(sdev, SDEV_DEL);
1366 	mutex_unlock(&sdev->state_mutex);
1367 
1368 	blk_cleanup_queue(sdev->request_queue);
1369 	cancel_work_sync(&sdev->requeue_work);
1370 
1371 	if (sdev->host->hostt->slave_destroy)
1372 		sdev->host->hostt->slave_destroy(sdev);
1373 	transport_destroy_device(dev);
1374 
1375 	/*
1376 	 * Paired with the kref_get() in scsi_sysfs_initialize().  We have
1377 	 * remoed sysfs visibility from the device, so make the target
1378 	 * invisible if this was the last device underneath it.
1379 	 */
1380 	scsi_target_reap(scsi_target(sdev));
1381 
1382 	put_device(dev);
1383 }
1384 
1385 /**
1386  * scsi_remove_device - unregister a device from the scsi bus
1387  * @sdev:	scsi_device to unregister
1388  **/
1389 void scsi_remove_device(struct scsi_device *sdev)
1390 {
1391 	struct Scsi_Host *shost = sdev->host;
1392 
1393 	mutex_lock(&shost->scan_mutex);
1394 	__scsi_remove_device(sdev);
1395 	mutex_unlock(&shost->scan_mutex);
1396 }
1397 EXPORT_SYMBOL(scsi_remove_device);
1398 
1399 static void __scsi_remove_target(struct scsi_target *starget)
1400 {
1401 	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
1402 	unsigned long flags;
1403 	struct scsi_device *sdev;
1404 
1405 	spin_lock_irqsave(shost->host_lock, flags);
1406  restart:
1407 	list_for_each_entry(sdev, &shost->__devices, siblings) {
1408 		/*
1409 		 * We cannot call scsi_device_get() here, as
1410 		 * we might've been called from rmmod() causing
1411 		 * scsi_device_get() to fail the module_is_live()
1412 		 * check.
1413 		 */
1414 		if (sdev->channel != starget->channel ||
1415 		    sdev->id != starget->id)
1416 			continue;
1417 		if (sdev->sdev_state == SDEV_DEL ||
1418 		    sdev->sdev_state == SDEV_CANCEL ||
1419 		    !get_device(&sdev->sdev_gendev))
1420 			continue;
1421 		spin_unlock_irqrestore(shost->host_lock, flags);
1422 		scsi_remove_device(sdev);
1423 		put_device(&sdev->sdev_gendev);
1424 		spin_lock_irqsave(shost->host_lock, flags);
1425 		goto restart;
1426 	}
1427 	spin_unlock_irqrestore(shost->host_lock, flags);
1428 }
1429 
1430 /**
1431  * scsi_remove_target - try to remove a target and all its devices
1432  * @dev: generic starget or parent of generic stargets to be removed
1433  *
1434  * Note: This is slightly racy.  It is possible that if the user
1435  * requests the addition of another device then the target won't be
1436  * removed.
1437  */
1438 void scsi_remove_target(struct device *dev)
1439 {
1440 	struct Scsi_Host *shost = dev_to_shost(dev->parent);
1441 	struct scsi_target *starget;
1442 	unsigned long flags;
1443 
1444 restart:
1445 	spin_lock_irqsave(shost->host_lock, flags);
1446 	list_for_each_entry(starget, &shost->__targets, siblings) {
1447 		if (starget->state == STARGET_DEL ||
1448 		    starget->state == STARGET_REMOVE ||
1449 		    starget->state == STARGET_CREATED_REMOVE)
1450 			continue;
1451 		if (starget->dev.parent == dev || &starget->dev == dev) {
1452 			kref_get(&starget->reap_ref);
1453 			if (starget->state == STARGET_CREATED)
1454 				starget->state = STARGET_CREATED_REMOVE;
1455 			else
1456 				starget->state = STARGET_REMOVE;
1457 			spin_unlock_irqrestore(shost->host_lock, flags);
1458 			__scsi_remove_target(starget);
1459 			scsi_target_reap(starget);
1460 			goto restart;
1461 		}
1462 	}
1463 	spin_unlock_irqrestore(shost->host_lock, flags);
1464 }
1465 EXPORT_SYMBOL(scsi_remove_target);
1466 
1467 int scsi_register_driver(struct device_driver *drv)
1468 {
1469 	drv->bus = &scsi_bus_type;
1470 
1471 	return driver_register(drv);
1472 }
1473 EXPORT_SYMBOL(scsi_register_driver);
1474 
1475 int scsi_register_interface(struct class_interface *intf)
1476 {
1477 	intf->class = &sdev_class;
1478 
1479 	return class_interface_register(intf);
1480 }
1481 EXPORT_SYMBOL(scsi_register_interface);
1482 
1483 /**
1484  * scsi_sysfs_add_host - add scsi host to subsystem
1485  * @shost:     scsi host struct to add to subsystem
1486  **/
1487 int scsi_sysfs_add_host(struct Scsi_Host *shost)
1488 {
1489 	int error, i;
1490 
1491 	/* add host specific attributes */
1492 	if (shost->hostt->shost_attrs) {
1493 		for (i = 0; shost->hostt->shost_attrs[i]; i++) {
1494 			error = device_create_file(&shost->shost_dev,
1495 					shost->hostt->shost_attrs[i]);
1496 			if (error)
1497 				return error;
1498 		}
1499 	}
1500 
1501 	transport_register_device(&shost->shost_gendev);
1502 	transport_configure_device(&shost->shost_gendev);
1503 	return 0;
1504 }
1505 
1506 static struct device_type scsi_dev_type = {
1507 	.name =		"scsi_device",
1508 	.release =	scsi_device_dev_release,
1509 	.groups =	scsi_sdev_attr_groups,
1510 };
1511 
1512 void scsi_sysfs_device_initialize(struct scsi_device *sdev)
1513 {
1514 	unsigned long flags;
1515 	struct Scsi_Host *shost = sdev->host;
1516 	struct scsi_target  *starget = sdev->sdev_target;
1517 
1518 	device_initialize(&sdev->sdev_gendev);
1519 	sdev->sdev_gendev.bus = &scsi_bus_type;
1520 	sdev->sdev_gendev.type = &scsi_dev_type;
1521 	dev_set_name(&sdev->sdev_gendev, "%d:%d:%d:%llu",
1522 		     sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
1523 
1524 	device_initialize(&sdev->sdev_dev);
1525 	sdev->sdev_dev.parent = get_device(&sdev->sdev_gendev);
1526 	sdev->sdev_dev.class = &sdev_class;
1527 	dev_set_name(&sdev->sdev_dev, "%d:%d:%d:%llu",
1528 		     sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
1529 	/*
1530 	 * Get a default scsi_level from the target (derived from sibling
1531 	 * devices).  This is the best we can do for guessing how to set
1532 	 * sdev->lun_in_cdb for the initial INQUIRY command.  For LUN 0 the
1533 	 * setting doesn't matter, because all the bits are zero anyway.
1534 	 * But it does matter for higher LUNs.
1535 	 */
1536 	sdev->scsi_level = starget->scsi_level;
1537 	if (sdev->scsi_level <= SCSI_2 &&
1538 			sdev->scsi_level != SCSI_UNKNOWN &&
1539 			!shost->no_scsi2_lun_in_cdb)
1540 		sdev->lun_in_cdb = 1;
1541 
1542 	transport_setup_device(&sdev->sdev_gendev);
1543 	spin_lock_irqsave(shost->host_lock, flags);
1544 	list_add_tail(&sdev->same_target_siblings, &starget->devices);
1545 	list_add_tail(&sdev->siblings, &shost->__devices);
1546 	spin_unlock_irqrestore(shost->host_lock, flags);
1547 	/*
1548 	 * device can now only be removed via __scsi_remove_device() so hold
1549 	 * the target.  Target will be held in CREATED state until something
1550 	 * beneath it becomes visible (in which case it moves to RUNNING)
1551 	 */
1552 	kref_get(&starget->reap_ref);
1553 }
1554 
1555 int scsi_is_sdev_device(const struct device *dev)
1556 {
1557 	return dev->type == &scsi_dev_type;
1558 }
1559 EXPORT_SYMBOL(scsi_is_sdev_device);
1560 
1561 /* A blank transport template that is used in drivers that don't
1562  * yet implement Transport Attributes */
1563 struct scsi_transport_template blank_transport_template = { { { {NULL, }, }, }, };
1564