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Commit | Line | Data |
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a6a8d9f8 CS |
1 | /* |
2 | * SCSI device handler infrastruture. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License as published by the | |
6 | * Free Software Foundation; either version 2 of the License, or (at your | |
7 | * option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright IBM Corporation, 2007 | |
19 | * Authors: | |
20 | * Chandra Seetharaman <sekharan@us.ibm.com> | |
21 | * Mike Anderson <andmike@linux.vnet.ibm.com> | |
22 | */ | |
23 | ||
5a0e3ad6 | 24 | #include <linux/slab.h> |
a6a8d9f8 CS |
25 | #include <scsi/scsi_dh.h> |
26 | #include "../scsi_priv.h" | |
27 | ||
7c32c7a2 HR |
28 | struct scsi_dh_devinfo_list { |
29 | struct list_head node; | |
30 | char vendor[9]; | |
31 | char model[17]; | |
32 | struct scsi_device_handler *handler; | |
33 | }; | |
34 | ||
a6a8d9f8 CS |
35 | static DEFINE_SPINLOCK(list_lock); |
36 | static LIST_HEAD(scsi_dh_list); | |
7c32c7a2 | 37 | static LIST_HEAD(scsi_dh_dev_list); |
a6a8d9f8 CS |
38 | |
39 | static struct scsi_device_handler *get_device_handler(const char *name) | |
40 | { | |
41 | struct scsi_device_handler *tmp, *found = NULL; | |
42 | ||
43 | spin_lock(&list_lock); | |
44 | list_for_each_entry(tmp, &scsi_dh_list, list) { | |
765cbc6d | 45 | if (!strncmp(tmp->name, name, strlen(tmp->name))) { |
a6a8d9f8 CS |
46 | found = tmp; |
47 | break; | |
48 | } | |
49 | } | |
50 | spin_unlock(&list_lock); | |
51 | return found; | |
52 | } | |
53 | ||
7c32c7a2 HR |
54 | |
55 | static struct scsi_device_handler * | |
56 | scsi_dh_cache_lookup(struct scsi_device *sdev) | |
a6a8d9f8 | 57 | { |
7c32c7a2 HR |
58 | struct scsi_dh_devinfo_list *tmp; |
59 | struct scsi_device_handler *found_dh = NULL; | |
60 | ||
61 | spin_lock(&list_lock); | |
62 | list_for_each_entry(tmp, &scsi_dh_dev_list, node) { | |
63 | if (!strncmp(sdev->vendor, tmp->vendor, strlen(tmp->vendor)) && | |
64 | !strncmp(sdev->model, tmp->model, strlen(tmp->model))) { | |
65 | found_dh = tmp->handler; | |
66 | break; | |
765cbc6d HR |
67 | } |
68 | } | |
7c32c7a2 | 69 | spin_unlock(&list_lock); |
a6a8d9f8 | 70 | |
7c32c7a2 HR |
71 | return found_dh; |
72 | } | |
73 | ||
74 | static int scsi_dh_handler_lookup(struct scsi_device_handler *scsi_dh, | |
75 | struct scsi_device *sdev) | |
76 | { | |
77 | int i, found = 0; | |
78 | ||
79 | for(i = 0; scsi_dh->devlist[i].vendor; i++) { | |
80 | if (!strncmp(sdev->vendor, scsi_dh->devlist[i].vendor, | |
81 | strlen(scsi_dh->devlist[i].vendor)) && | |
82 | !strncmp(sdev->model, scsi_dh->devlist[i].model, | |
83 | strlen(scsi_dh->devlist[i].model))) { | |
84 | found = 1; | |
85 | break; | |
86 | } | |
87 | } | |
88 | return found; | |
89 | } | |
90 | ||
91 | /* | |
92 | * device_handler_match - Attach a device handler to a device | |
93 | * @scsi_dh - The device handler to match against or NULL | |
94 | * @sdev - SCSI device to be tested against @scsi_dh | |
95 | * | |
96 | * Tests @sdev against the device handler @scsi_dh or against | |
97 | * all registered device_handler if @scsi_dh == NULL. | |
98 | * Returns the found device handler or NULL if not found. | |
99 | */ | |
100 | static struct scsi_device_handler * | |
101 | device_handler_match(struct scsi_device_handler *scsi_dh, | |
102 | struct scsi_device *sdev) | |
103 | { | |
104 | struct scsi_device_handler *found_dh = NULL; | |
105 | struct scsi_dh_devinfo_list *tmp; | |
106 | ||
107 | found_dh = scsi_dh_cache_lookup(sdev); | |
108 | if (found_dh) | |
109 | return found_dh; | |
110 | ||
111 | if (scsi_dh) { | |
112 | if (scsi_dh_handler_lookup(scsi_dh, sdev)) | |
113 | found_dh = scsi_dh; | |
114 | } else { | |
115 | struct scsi_device_handler *tmp_dh; | |
116 | ||
117 | spin_lock(&list_lock); | |
118 | list_for_each_entry(tmp_dh, &scsi_dh_list, list) { | |
119 | if (scsi_dh_handler_lookup(tmp_dh, sdev)) | |
120 | found_dh = tmp_dh; | |
121 | } | |
122 | spin_unlock(&list_lock); | |
123 | } | |
124 | ||
125 | if (found_dh) { /* If device is found, add it to the cache */ | |
126 | tmp = kmalloc(sizeof(*tmp), GFP_KERNEL); | |
127 | if (tmp) { | |
128 | strncpy(tmp->vendor, sdev->vendor, 8); | |
129 | strncpy(tmp->model, sdev->model, 16); | |
130 | tmp->vendor[8] = '\0'; | |
131 | tmp->model[16] = '\0'; | |
132 | tmp->handler = found_dh; | |
133 | spin_lock(&list_lock); | |
134 | list_add(&tmp->node, &scsi_dh_dev_list); | |
135 | spin_unlock(&list_lock); | |
136 | } else { | |
137 | found_dh = NULL; | |
138 | } | |
139 | } | |
140 | ||
141 | return found_dh; | |
a6a8d9f8 CS |
142 | } |
143 | ||
144 | /* | |
765cbc6d HR |
145 | * scsi_dh_handler_attach - Attach a device handler to a device |
146 | * @sdev - SCSI device the device handler should attach to | |
147 | * @scsi_dh - The device handler to attach | |
148 | */ | |
149 | static int scsi_dh_handler_attach(struct scsi_device *sdev, | |
150 | struct scsi_device_handler *scsi_dh) | |
151 | { | |
152 | int err = 0; | |
153 | ||
154 | if (sdev->scsi_dh_data) { | |
155 | if (sdev->scsi_dh_data->scsi_dh != scsi_dh) | |
156 | err = -EBUSY; | |
6c10db72 CS |
157 | else |
158 | kref_get(&sdev->scsi_dh_data->kref); | |
159 | } else if (scsi_dh->attach) { | |
765cbc6d | 160 | err = scsi_dh->attach(sdev); |
6c10db72 CS |
161 | if (!err) { |
162 | kref_init(&sdev->scsi_dh_data->kref); | |
163 | sdev->scsi_dh_data->sdev = sdev; | |
164 | } | |
165 | } | |
765cbc6d HR |
166 | return err; |
167 | } | |
168 | ||
6c10db72 CS |
169 | static void __detach_handler (struct kref *kref) |
170 | { | |
171 | struct scsi_dh_data *scsi_dh_data = container_of(kref, struct scsi_dh_data, kref); | |
172 | scsi_dh_data->scsi_dh->detach(scsi_dh_data->sdev); | |
173 | } | |
174 | ||
765cbc6d HR |
175 | /* |
176 | * scsi_dh_handler_detach - Detach a device handler from a device | |
177 | * @sdev - SCSI device the device handler should be detached from | |
178 | * @scsi_dh - Device handler to be detached | |
a6a8d9f8 | 179 | * |
765cbc6d | 180 | * Detach from a device handler. If a device handler is specified, |
4c05ae52 | 181 | * only detach if the currently attached handler matches @scsi_dh. |
a6a8d9f8 | 182 | */ |
765cbc6d HR |
183 | static void scsi_dh_handler_detach(struct scsi_device *sdev, |
184 | struct scsi_device_handler *scsi_dh) | |
a6a8d9f8 | 185 | { |
765cbc6d HR |
186 | if (!sdev->scsi_dh_data) |
187 | return; | |
a6a8d9f8 | 188 | |
765cbc6d HR |
189 | if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh) |
190 | return; | |
a6a8d9f8 | 191 | |
765cbc6d HR |
192 | if (!scsi_dh) |
193 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
194 | ||
195 | if (scsi_dh && scsi_dh->detach) | |
6c10db72 | 196 | kref_put(&sdev->scsi_dh_data->kref, __detach_handler); |
765cbc6d HR |
197 | } |
198 | ||
4c05ae52 HR |
199 | /* |
200 | * Functions for sysfs attribute 'dh_state' | |
201 | */ | |
202 | static ssize_t | |
203 | store_dh_state(struct device *dev, struct device_attribute *attr, | |
204 | const char *buf, size_t count) | |
205 | { | |
206 | struct scsi_device *sdev = to_scsi_device(dev); | |
207 | struct scsi_device_handler *scsi_dh; | |
208 | int err = -EINVAL; | |
209 | ||
210 | if (!sdev->scsi_dh_data) { | |
211 | /* | |
212 | * Attach to a device handler | |
213 | */ | |
214 | if (!(scsi_dh = get_device_handler(buf))) | |
215 | return err; | |
216 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
217 | } else { | |
218 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
219 | if (!strncmp(buf, "detach", 6)) { | |
220 | /* | |
221 | * Detach from a device handler | |
222 | */ | |
223 | scsi_dh_handler_detach(sdev, scsi_dh); | |
224 | err = 0; | |
225 | } else if (!strncmp(buf, "activate", 8)) { | |
226 | /* | |
227 | * Activate a device handler | |
228 | */ | |
229 | if (scsi_dh->activate) | |
3ae31f6a | 230 | err = scsi_dh->activate(sdev, NULL, NULL); |
4c05ae52 HR |
231 | else |
232 | err = 0; | |
233 | } | |
234 | } | |
235 | ||
236 | return err<0?err:count; | |
237 | } | |
238 | ||
239 | static ssize_t | |
240 | show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) | |
241 | { | |
242 | struct scsi_device *sdev = to_scsi_device(dev); | |
243 | ||
244 | if (!sdev->scsi_dh_data) | |
245 | return snprintf(buf, 20, "detached\n"); | |
246 | ||
247 | return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name); | |
248 | } | |
249 | ||
250 | static struct device_attribute scsi_dh_state_attr = | |
251 | __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, | |
252 | store_dh_state); | |
253 | ||
254 | /* | |
255 | * scsi_dh_sysfs_attr_add - Callback for scsi_init_dh | |
256 | */ | |
257 | static int scsi_dh_sysfs_attr_add(struct device *dev, void *data) | |
258 | { | |
259 | struct scsi_device *sdev; | |
260 | int err; | |
261 | ||
262 | if (!scsi_is_sdev_device(dev)) | |
263 | return 0; | |
264 | ||
265 | sdev = to_scsi_device(dev); | |
266 | ||
267 | err = device_create_file(&sdev->sdev_gendev, | |
268 | &scsi_dh_state_attr); | |
269 | ||
270 | return 0; | |
271 | } | |
272 | ||
273 | /* | |
274 | * scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh | |
275 | */ | |
276 | static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data) | |
277 | { | |
278 | struct scsi_device *sdev; | |
279 | ||
280 | if (!scsi_is_sdev_device(dev)) | |
281 | return 0; | |
282 | ||
283 | sdev = to_scsi_device(dev); | |
284 | ||
285 | device_remove_file(&sdev->sdev_gendev, | |
286 | &scsi_dh_state_attr); | |
287 | ||
288 | return 0; | |
289 | } | |
290 | ||
765cbc6d HR |
291 | /* |
292 | * scsi_dh_notifier - notifier chain callback | |
293 | */ | |
294 | static int scsi_dh_notifier(struct notifier_block *nb, | |
295 | unsigned long action, void *data) | |
296 | { | |
297 | struct device *dev = data; | |
298 | struct scsi_device *sdev; | |
299 | int err = 0; | |
7c32c7a2 | 300 | struct scsi_device_handler *devinfo = NULL; |
765cbc6d HR |
301 | |
302 | if (!scsi_is_sdev_device(dev)) | |
303 | return 0; | |
304 | ||
305 | sdev = to_scsi_device(dev); | |
a6a8d9f8 | 306 | |
765cbc6d | 307 | if (action == BUS_NOTIFY_ADD_DEVICE) { |
5917290c CS |
308 | err = device_create_file(dev, &scsi_dh_state_attr); |
309 | /* don't care about err */ | |
7c32c7a2 | 310 | devinfo = device_handler_match(NULL, sdev); |
5917290c CS |
311 | if (devinfo) |
312 | err = scsi_dh_handler_attach(sdev, devinfo); | |
765cbc6d | 313 | } else if (action == BUS_NOTIFY_DEL_DEVICE) { |
4c05ae52 | 314 | device_remove_file(dev, &scsi_dh_state_attr); |
765cbc6d HR |
315 | scsi_dh_handler_detach(sdev, NULL); |
316 | } | |
765cbc6d | 317 | return err; |
a6a8d9f8 | 318 | } |
a6a8d9f8 | 319 | |
765cbc6d HR |
320 | /* |
321 | * scsi_dh_notifier_add - Callback for scsi_register_device_handler | |
322 | */ | |
323 | static int scsi_dh_notifier_add(struct device *dev, void *data) | |
324 | { | |
325 | struct scsi_device_handler *scsi_dh = data; | |
326 | struct scsi_device *sdev; | |
327 | ||
328 | if (!scsi_is_sdev_device(dev)) | |
329 | return 0; | |
330 | ||
331 | if (!get_device(dev)) | |
332 | return 0; | |
333 | ||
334 | sdev = to_scsi_device(dev); | |
335 | ||
336 | if (device_handler_match(scsi_dh, sdev)) | |
337 | scsi_dh_handler_attach(sdev, scsi_dh); | |
338 | ||
339 | put_device(dev); | |
340 | ||
341 | return 0; | |
342 | } | |
343 | ||
344 | /* | |
345 | * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler | |
346 | */ | |
a6a8d9f8 CS |
347 | static int scsi_dh_notifier_remove(struct device *dev, void *data) |
348 | { | |
349 | struct scsi_device_handler *scsi_dh = data; | |
765cbc6d HR |
350 | struct scsi_device *sdev; |
351 | ||
352 | if (!scsi_is_sdev_device(dev)) | |
353 | return 0; | |
354 | ||
355 | if (!get_device(dev)) | |
356 | return 0; | |
357 | ||
358 | sdev = to_scsi_device(dev); | |
359 | ||
360 | scsi_dh_handler_detach(sdev, scsi_dh); | |
361 | ||
362 | put_device(dev); | |
a6a8d9f8 | 363 | |
a6a8d9f8 CS |
364 | return 0; |
365 | } | |
366 | ||
765cbc6d HR |
367 | /* |
368 | * scsi_register_device_handler - register a device handler personality | |
369 | * module. | |
370 | * @scsi_dh - device handler to be registered. | |
371 | * | |
372 | * Returns 0 on success, -EBUSY if handler already registered. | |
373 | */ | |
374 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) | |
375 | { | |
376 | if (get_device_handler(scsi_dh->name)) | |
377 | return -EBUSY; | |
378 | ||
379 | spin_lock(&list_lock); | |
380 | list_add(&scsi_dh->list, &scsi_dh_list); | |
381 | spin_unlock(&list_lock); | |
382 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add); | |
383 | printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); | |
384 | ||
385 | return SCSI_DH_OK; | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); | |
388 | ||
a6a8d9f8 CS |
389 | /* |
390 | * scsi_unregister_device_handler - register a device handler personality | |
391 | * module. | |
392 | * @scsi_dh - device handler to be unregistered. | |
393 | * | |
394 | * Returns 0 on success, -ENODEV if handler not registered. | |
395 | */ | |
396 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) | |
397 | { | |
7c32c7a2 HR |
398 | struct scsi_dh_devinfo_list *tmp, *pos; |
399 | ||
765cbc6d HR |
400 | if (!get_device_handler(scsi_dh->name)) |
401 | return -ENODEV; | |
a6a8d9f8 CS |
402 | |
403 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, | |
765cbc6d HR |
404 | scsi_dh_notifier_remove); |
405 | ||
a6a8d9f8 CS |
406 | spin_lock(&list_lock); |
407 | list_del(&scsi_dh->list); | |
7c32c7a2 HR |
408 | list_for_each_entry_safe(pos, tmp, &scsi_dh_dev_list, node) { |
409 | if (pos->handler == scsi_dh) { | |
410 | list_del(&pos->node); | |
411 | kfree(pos); | |
412 | } | |
413 | } | |
a6a8d9f8 | 414 | spin_unlock(&list_lock); |
765cbc6d | 415 | printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |
a6a8d9f8 | 416 | |
765cbc6d | 417 | return SCSI_DH_OK; |
a6a8d9f8 CS |
418 | } |
419 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); | |
420 | ||
421 | /* | |
422 | * scsi_dh_activate - activate the path associated with the scsi_device | |
423 | * corresponding to the given request queue. | |
3ae31f6a CS |
424 | * Returns immediately without waiting for activation to be completed. |
425 | * @q - Request queue that is associated with the scsi_device to be | |
426 | * activated. | |
427 | * @fn - Function to be called upon completion of the activation. | |
428 | * Function fn is called with data (below) and the error code. | |
429 | * Function fn may be called from the same calling context. So, | |
430 | * do not hold the lock in the caller which may be needed in fn. | |
431 | * @data - data passed to the function fn upon completion. | |
432 | * | |
a6a8d9f8 | 433 | */ |
3ae31f6a | 434 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
a6a8d9f8 CS |
435 | { |
436 | int err = 0; | |
437 | unsigned long flags; | |
438 | struct scsi_device *sdev; | |
439 | struct scsi_device_handler *scsi_dh = NULL; | |
440 | ||
441 | spin_lock_irqsave(q->queue_lock, flags); | |
442 | sdev = q->queuedata; | |
443 | if (sdev && sdev->scsi_dh_data) | |
444 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
445 | if (!scsi_dh || !get_device(&sdev->sdev_gendev)) | |
446 | err = SCSI_DH_NOSYS; | |
447 | spin_unlock_irqrestore(q->queue_lock, flags); | |
448 | ||
449 | if (err) | |
450 | return err; | |
451 | ||
452 | if (scsi_dh->activate) | |
3ae31f6a | 453 | err = scsi_dh->activate(sdev, fn, data); |
a6a8d9f8 CS |
454 | put_device(&sdev->sdev_gendev); |
455 | return err; | |
456 | } | |
457 | EXPORT_SYMBOL_GPL(scsi_dh_activate); | |
458 | ||
18ee70c9 CS |
459 | /* |
460 | * scsi_dh_set_params - set the parameters for the device as per the | |
461 | * string specified in params. | |
462 | * @q - Request queue that is associated with the scsi_device for | |
463 | * which the parameters to be set. | |
464 | * @params - parameters in the following format | |
465 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
466 | * for example, string for 2 parameters with value 10 and 21 | |
467 | * is specified as "2\010\021\0". | |
468 | */ | |
469 | int scsi_dh_set_params(struct request_queue *q, const char *params) | |
470 | { | |
471 | int err = -SCSI_DH_NOSYS; | |
472 | unsigned long flags; | |
473 | struct scsi_device *sdev; | |
474 | struct scsi_device_handler *scsi_dh = NULL; | |
475 | ||
476 | spin_lock_irqsave(q->queue_lock, flags); | |
477 | sdev = q->queuedata; | |
478 | if (sdev && sdev->scsi_dh_data) | |
479 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
480 | if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) | |
481 | err = 0; | |
482 | spin_unlock_irqrestore(q->queue_lock, flags); | |
483 | ||
484 | if (err) | |
485 | return err; | |
486 | err = scsi_dh->set_params(sdev, params); | |
487 | put_device(&sdev->sdev_gendev); | |
488 | return err; | |
489 | } | |
490 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); | |
491 | ||
a6a8d9f8 CS |
492 | /* |
493 | * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for | |
494 | * the given name. FALSE(0) otherwise. | |
495 | * @name - name of the device handler. | |
496 | */ | |
497 | int scsi_dh_handler_exist(const char *name) | |
498 | { | |
499 | return (get_device_handler(name) != NULL); | |
500 | } | |
501 | EXPORT_SYMBOL_GPL(scsi_dh_handler_exist); | |
502 | ||
ae11b1b3 HR |
503 | /* |
504 | * scsi_dh_handler_attach - Attach device handler | |
505 | * @sdev - sdev the handler should be attached to | |
506 | * @name - name of the handler to attach | |
507 | */ | |
508 | int scsi_dh_attach(struct request_queue *q, const char *name) | |
509 | { | |
510 | unsigned long flags; | |
511 | struct scsi_device *sdev; | |
512 | struct scsi_device_handler *scsi_dh; | |
513 | int err = 0; | |
514 | ||
515 | scsi_dh = get_device_handler(name); | |
516 | if (!scsi_dh) | |
517 | return -EINVAL; | |
518 | ||
519 | spin_lock_irqsave(q->queue_lock, flags); | |
520 | sdev = q->queuedata; | |
521 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
522 | err = -ENODEV; | |
523 | spin_unlock_irqrestore(q->queue_lock, flags); | |
524 | ||
525 | if (!err) { | |
526 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
ae11b1b3 HR |
527 | put_device(&sdev->sdev_gendev); |
528 | } | |
529 | return err; | |
530 | } | |
531 | EXPORT_SYMBOL_GPL(scsi_dh_attach); | |
532 | ||
533 | /* | |
534 | * scsi_dh_handler_detach - Detach device handler | |
535 | * @sdev - sdev the handler should be detached from | |
536 | * | |
537 | * This function will detach the device handler only | |
538 | * if the sdev is not part of the internal list, ie | |
539 | * if it has been attached manually. | |
540 | */ | |
541 | void scsi_dh_detach(struct request_queue *q) | |
542 | { | |
543 | unsigned long flags; | |
544 | struct scsi_device *sdev; | |
545 | struct scsi_device_handler *scsi_dh = NULL; | |
546 | ||
547 | spin_lock_irqsave(q->queue_lock, flags); | |
548 | sdev = q->queuedata; | |
549 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
550 | sdev = NULL; | |
551 | spin_unlock_irqrestore(q->queue_lock, flags); | |
552 | ||
553 | if (!sdev) | |
554 | return; | |
555 | ||
556 | if (sdev->scsi_dh_data) { | |
ae11b1b3 | 557 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
6c10db72 | 558 | scsi_dh_handler_detach(sdev, scsi_dh); |
ae11b1b3 HR |
559 | } |
560 | put_device(&sdev->sdev_gendev); | |
561 | } | |
562 | EXPORT_SYMBOL_GPL(scsi_dh_detach); | |
563 | ||
765cbc6d HR |
564 | static struct notifier_block scsi_dh_nb = { |
565 | .notifier_call = scsi_dh_notifier | |
566 | }; | |
567 | ||
568 | static int __init scsi_dh_init(void) | |
569 | { | |
570 | int r; | |
571 | ||
572 | r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb); | |
573 | ||
4c05ae52 HR |
574 | if (!r) |
575 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, | |
576 | scsi_dh_sysfs_attr_add); | |
577 | ||
765cbc6d HR |
578 | return r; |
579 | } | |
580 | ||
581 | static void __exit scsi_dh_exit(void) | |
582 | { | |
4c05ae52 HR |
583 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, |
584 | scsi_dh_sysfs_attr_remove); | |
765cbc6d HR |
585 | bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb); |
586 | } | |
587 | ||
588 | module_init(scsi_dh_init); | |
589 | module_exit(scsi_dh_exit); | |
590 | ||
a6a8d9f8 CS |
591 | MODULE_DESCRIPTION("SCSI device handler"); |
592 | MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>"); | |
593 | MODULE_LICENSE("GPL"); |