Commit | Line | Data |
---|---|---|
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> |
acf3368f | 25 | #include <linux/module.h> |
a6a8d9f8 CS |
26 | #include <scsi/scsi_dh.h> |
27 | #include "../scsi_priv.h" | |
28 | ||
29 | static DEFINE_SPINLOCK(list_lock); | |
30 | static LIST_HEAD(scsi_dh_list); | |
31 | ||
566079c8 | 32 | static struct scsi_device_handler *__scsi_dh_lookup(const char *name) |
a6a8d9f8 CS |
33 | { |
34 | struct scsi_device_handler *tmp, *found = NULL; | |
35 | ||
36 | spin_lock(&list_lock); | |
37 | list_for_each_entry(tmp, &scsi_dh_list, list) { | |
765cbc6d | 38 | if (!strncmp(tmp->name, name, strlen(tmp->name))) { |
a6a8d9f8 CS |
39 | found = tmp; |
40 | break; | |
41 | } | |
42 | } | |
43 | spin_unlock(&list_lock); | |
44 | return found; | |
45 | } | |
46 | ||
566079c8 CH |
47 | static struct scsi_device_handler *scsi_dh_lookup(const char *name) |
48 | { | |
49 | struct scsi_device_handler *dh; | |
50 | ||
51 | dh = __scsi_dh_lookup(name); | |
52 | if (!dh) { | |
53 | request_module(name); | |
54 | dh = __scsi_dh_lookup(name); | |
55 | } | |
56 | ||
57 | return dh; | |
58 | } | |
59 | ||
6c3633d0 HR |
60 | /* |
61 | * device_handler_match_function - Match a device handler to a device | |
62 | * @sdev - SCSI device to be tested | |
63 | * | |
64 | * Tests @sdev against the match function of all registered device_handler. | |
65 | * Returns the found device handler or NULL if not found. | |
66 | */ | |
67 | static struct scsi_device_handler * | |
68 | device_handler_match_function(struct scsi_device *sdev) | |
69 | { | |
70 | struct scsi_device_handler *tmp_dh, *found_dh = NULL; | |
71 | ||
72 | spin_lock(&list_lock); | |
73 | list_for_each_entry(tmp_dh, &scsi_dh_list, list) { | |
74 | if (tmp_dh->match && tmp_dh->match(sdev)) { | |
75 | found_dh = tmp_dh; | |
76 | break; | |
77 | } | |
78 | } | |
79 | spin_unlock(&list_lock); | |
80 | return found_dh; | |
81 | } | |
82 | ||
7c32c7a2 HR |
83 | /* |
84 | * device_handler_match - Attach a device handler to a device | |
85 | * @scsi_dh - The device handler to match against or NULL | |
86 | * @sdev - SCSI device to be tested against @scsi_dh | |
87 | * | |
88 | * Tests @sdev against the device handler @scsi_dh or against | |
89 | * all registered device_handler if @scsi_dh == NULL. | |
90 | * Returns the found device handler or NULL if not found. | |
91 | */ | |
92 | static struct scsi_device_handler * | |
93 | device_handler_match(struct scsi_device_handler *scsi_dh, | |
94 | struct scsi_device *sdev) | |
95 | { | |
6c3633d0 | 96 | struct scsi_device_handler *found_dh; |
7c32c7a2 | 97 | |
6c3633d0 | 98 | found_dh = device_handler_match_function(sdev); |
7c32c7a2 | 99 | |
940d7faa PJ |
100 | if (scsi_dh && found_dh != scsi_dh) |
101 | found_dh = NULL; | |
7c32c7a2 HR |
102 | |
103 | return found_dh; | |
a6a8d9f8 CS |
104 | } |
105 | ||
106 | /* | |
765cbc6d HR |
107 | * scsi_dh_handler_attach - Attach a device handler to a device |
108 | * @sdev - SCSI device the device handler should attach to | |
109 | * @scsi_dh - The device handler to attach | |
110 | */ | |
111 | static int scsi_dh_handler_attach(struct scsi_device *sdev, | |
112 | struct scsi_device_handler *scsi_dh) | |
113 | { | |
1d520328 | 114 | struct scsi_dh_data *d; |
765cbc6d | 115 | |
1f12ffa5 CH |
116 | if (!try_module_get(scsi_dh->module)) |
117 | return -EINVAL; | |
27c888f0 | 118 | |
1d520328 CH |
119 | d = scsi_dh->attach(sdev); |
120 | if (IS_ERR(d)) { | |
121 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n", | |
122 | scsi_dh->name, PTR_ERR(d)); | |
1f12ffa5 | 123 | module_put(scsi_dh->module); |
1d520328 | 124 | return PTR_ERR(d); |
6c10db72 | 125 | } |
1f12ffa5 | 126 | |
1d520328 | 127 | d->scsi_dh = scsi_dh; |
1d520328 CH |
128 | d->sdev = sdev; |
129 | ||
130 | spin_lock_irq(sdev->request_queue->queue_lock); | |
131 | sdev->scsi_dh_data = d; | |
132 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
133 | return 0; | |
765cbc6d HR |
134 | } |
135 | ||
1bab0de0 CH |
136 | /* |
137 | * scsi_dh_handler_detach - Detach a device handler from a device | |
138 | * @sdev - SCSI device the device handler should be detached from | |
139 | */ | |
140 | static void scsi_dh_handler_detach(struct scsi_device *sdev) | |
6c10db72 | 141 | { |
1bab0de0 | 142 | struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; |
27c888f0 | 143 | struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; |
1d520328 | 144 | |
28072ad5 MC |
145 | scsi_dh->detach(sdev); |
146 | ||
1d520328 CH |
147 | spin_lock_irq(sdev->request_queue->queue_lock); |
148 | sdev->scsi_dh_data = NULL; | |
149 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
27c888f0 | 150 | |
1d520328 | 151 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); |
27c888f0 | 152 | module_put(scsi_dh->module); |
6c10db72 CS |
153 | } |
154 | ||
4c05ae52 HR |
155 | /* |
156 | * Functions for sysfs attribute 'dh_state' | |
157 | */ | |
158 | static ssize_t | |
159 | store_dh_state(struct device *dev, struct device_attribute *attr, | |
160 | const char *buf, size_t count) | |
161 | { | |
162 | struct scsi_device *sdev = to_scsi_device(dev); | |
163 | struct scsi_device_handler *scsi_dh; | |
164 | int err = -EINVAL; | |
165 | ||
6bc8d2a0 HR |
166 | if (sdev->sdev_state == SDEV_CANCEL || |
167 | sdev->sdev_state == SDEV_DEL) | |
168 | return -ENODEV; | |
169 | ||
4c05ae52 HR |
170 | if (!sdev->scsi_dh_data) { |
171 | /* | |
172 | * Attach to a device handler | |
173 | */ | |
566079c8 CH |
174 | scsi_dh = scsi_dh_lookup(buf); |
175 | if (!scsi_dh) | |
4c05ae52 HR |
176 | return err; |
177 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
178 | } else { | |
179 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
180 | if (!strncmp(buf, "detach", 6)) { | |
181 | /* | |
182 | * Detach from a device handler | |
183 | */ | |
1bab0de0 | 184 | scsi_dh_handler_detach(sdev); |
4c05ae52 HR |
185 | err = 0; |
186 | } else if (!strncmp(buf, "activate", 8)) { | |
187 | /* | |
188 | * Activate a device handler | |
189 | */ | |
190 | if (scsi_dh->activate) | |
3ae31f6a | 191 | err = scsi_dh->activate(sdev, NULL, NULL); |
4c05ae52 HR |
192 | else |
193 | err = 0; | |
194 | } | |
195 | } | |
196 | ||
197 | return err<0?err:count; | |
198 | } | |
199 | ||
200 | static ssize_t | |
201 | show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) | |
202 | { | |
203 | struct scsi_device *sdev = to_scsi_device(dev); | |
204 | ||
205 | if (!sdev->scsi_dh_data) | |
206 | return snprintf(buf, 20, "detached\n"); | |
207 | ||
208 | return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name); | |
209 | } | |
210 | ||
211 | static struct device_attribute scsi_dh_state_attr = | |
212 | __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, | |
213 | store_dh_state); | |
214 | ||
215 | /* | |
216 | * scsi_dh_sysfs_attr_add - Callback for scsi_init_dh | |
217 | */ | |
218 | static int scsi_dh_sysfs_attr_add(struct device *dev, void *data) | |
219 | { | |
220 | struct scsi_device *sdev; | |
221 | int err; | |
222 | ||
223 | if (!scsi_is_sdev_device(dev)) | |
224 | return 0; | |
225 | ||
226 | sdev = to_scsi_device(dev); | |
227 | ||
228 | err = device_create_file(&sdev->sdev_gendev, | |
229 | &scsi_dh_state_attr); | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | /* | |
235 | * scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh | |
236 | */ | |
237 | static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data) | |
238 | { | |
239 | struct scsi_device *sdev; | |
240 | ||
241 | if (!scsi_is_sdev_device(dev)) | |
242 | return 0; | |
243 | ||
244 | sdev = to_scsi_device(dev); | |
245 | ||
246 | device_remove_file(&sdev->sdev_gendev, | |
247 | &scsi_dh_state_attr); | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
765cbc6d HR |
252 | /* |
253 | * scsi_dh_notifier - notifier chain callback | |
254 | */ | |
255 | static int scsi_dh_notifier(struct notifier_block *nb, | |
256 | unsigned long action, void *data) | |
257 | { | |
258 | struct device *dev = data; | |
259 | struct scsi_device *sdev; | |
260 | int err = 0; | |
7c32c7a2 | 261 | struct scsi_device_handler *devinfo = NULL; |
765cbc6d HR |
262 | |
263 | if (!scsi_is_sdev_device(dev)) | |
264 | return 0; | |
265 | ||
266 | sdev = to_scsi_device(dev); | |
a6a8d9f8 | 267 | |
765cbc6d | 268 | if (action == BUS_NOTIFY_ADD_DEVICE) { |
5917290c CS |
269 | err = device_create_file(dev, &scsi_dh_state_attr); |
270 | /* don't care about err */ | |
7c32c7a2 | 271 | devinfo = device_handler_match(NULL, sdev); |
5917290c CS |
272 | if (devinfo) |
273 | err = scsi_dh_handler_attach(sdev, devinfo); | |
765cbc6d | 274 | } else if (action == BUS_NOTIFY_DEL_DEVICE) { |
4c05ae52 | 275 | device_remove_file(dev, &scsi_dh_state_attr); |
1bab0de0 CH |
276 | if (sdev->scsi_dh_data) |
277 | scsi_dh_handler_detach(sdev); | |
765cbc6d | 278 | } |
765cbc6d | 279 | return err; |
a6a8d9f8 | 280 | } |
a6a8d9f8 | 281 | |
765cbc6d HR |
282 | /* |
283 | * scsi_dh_notifier_add - Callback for scsi_register_device_handler | |
284 | */ | |
285 | static int scsi_dh_notifier_add(struct device *dev, void *data) | |
286 | { | |
287 | struct scsi_device_handler *scsi_dh = data; | |
288 | struct scsi_device *sdev; | |
289 | ||
290 | if (!scsi_is_sdev_device(dev)) | |
291 | return 0; | |
292 | ||
293 | if (!get_device(dev)) | |
294 | return 0; | |
295 | ||
296 | sdev = to_scsi_device(dev); | |
297 | ||
298 | if (device_handler_match(scsi_dh, sdev)) | |
299 | scsi_dh_handler_attach(sdev, scsi_dh); | |
300 | ||
301 | put_device(dev); | |
302 | ||
303 | return 0; | |
304 | } | |
305 | ||
306 | /* | |
307 | * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler | |
308 | */ | |
a6a8d9f8 CS |
309 | static int scsi_dh_notifier_remove(struct device *dev, void *data) |
310 | { | |
311 | struct scsi_device_handler *scsi_dh = data; | |
765cbc6d HR |
312 | struct scsi_device *sdev; |
313 | ||
314 | if (!scsi_is_sdev_device(dev)) | |
315 | return 0; | |
316 | ||
317 | if (!get_device(dev)) | |
318 | return 0; | |
319 | ||
320 | sdev = to_scsi_device(dev); | |
321 | ||
1bab0de0 CH |
322 | if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh == scsi_dh) |
323 | scsi_dh_handler_detach(sdev); | |
765cbc6d HR |
324 | |
325 | put_device(dev); | |
a6a8d9f8 | 326 | |
a6a8d9f8 CS |
327 | return 0; |
328 | } | |
329 | ||
765cbc6d HR |
330 | /* |
331 | * scsi_register_device_handler - register a device handler personality | |
332 | * module. | |
333 | * @scsi_dh - device handler to be registered. | |
334 | * | |
335 | * Returns 0 on success, -EBUSY if handler already registered. | |
336 | */ | |
337 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) | |
338 | { | |
566079c8 | 339 | if (__scsi_dh_lookup(scsi_dh->name)) |
765cbc6d HR |
340 | return -EBUSY; |
341 | ||
1f12ffa5 CH |
342 | if (!scsi_dh->attach || !scsi_dh->detach) |
343 | return -EINVAL; | |
344 | ||
765cbc6d HR |
345 | spin_lock(&list_lock); |
346 | list_add(&scsi_dh->list, &scsi_dh_list); | |
347 | spin_unlock(&list_lock); | |
940d7faa | 348 | |
765cbc6d HR |
349 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add); |
350 | printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); | |
351 | ||
352 | return SCSI_DH_OK; | |
353 | } | |
354 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); | |
355 | ||
a6a8d9f8 CS |
356 | /* |
357 | * scsi_unregister_device_handler - register a device handler personality | |
358 | * module. | |
359 | * @scsi_dh - device handler to be unregistered. | |
360 | * | |
361 | * Returns 0 on success, -ENODEV if handler not registered. | |
362 | */ | |
363 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) | |
364 | { | |
7c32c7a2 | 365 | |
566079c8 | 366 | if (!__scsi_dh_lookup(scsi_dh->name)) |
765cbc6d | 367 | return -ENODEV; |
a6a8d9f8 CS |
368 | |
369 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, | |
765cbc6d HR |
370 | scsi_dh_notifier_remove); |
371 | ||
a6a8d9f8 CS |
372 | spin_lock(&list_lock); |
373 | list_del(&scsi_dh->list); | |
374 | spin_unlock(&list_lock); | |
765cbc6d | 375 | printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |
a6a8d9f8 | 376 | |
765cbc6d | 377 | return SCSI_DH_OK; |
a6a8d9f8 CS |
378 | } |
379 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); | |
380 | ||
381 | /* | |
382 | * scsi_dh_activate - activate the path associated with the scsi_device | |
383 | * corresponding to the given request queue. | |
3ae31f6a CS |
384 | * Returns immediately without waiting for activation to be completed. |
385 | * @q - Request queue that is associated with the scsi_device to be | |
386 | * activated. | |
387 | * @fn - Function to be called upon completion of the activation. | |
388 | * Function fn is called with data (below) and the error code. | |
389 | * Function fn may be called from the same calling context. So, | |
390 | * do not hold the lock in the caller which may be needed in fn. | |
391 | * @data - data passed to the function fn upon completion. | |
392 | * | |
a6a8d9f8 | 393 | */ |
3ae31f6a | 394 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
a6a8d9f8 CS |
395 | { |
396 | int err = 0; | |
397 | unsigned long flags; | |
398 | struct scsi_device *sdev; | |
399 | struct scsi_device_handler *scsi_dh = NULL; | |
0b839357 | 400 | struct device *dev = NULL; |
a6a8d9f8 CS |
401 | |
402 | spin_lock_irqsave(q->queue_lock, flags); | |
403 | sdev = q->queuedata; | |
a18a920c MB |
404 | if (!sdev) { |
405 | spin_unlock_irqrestore(q->queue_lock, flags); | |
406 | err = SCSI_DH_NOSYS; | |
407 | if (fn) | |
408 | fn(data, err); | |
409 | return err; | |
410 | } | |
411 | ||
412 | if (sdev->scsi_dh_data) | |
a6a8d9f8 | 413 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
0b839357 MS |
414 | dev = get_device(&sdev->sdev_gendev); |
415 | if (!scsi_dh || !dev || | |
db422318 MH |
416 | sdev->sdev_state == SDEV_CANCEL || |
417 | sdev->sdev_state == SDEV_DEL) | |
a6a8d9f8 | 418 | err = SCSI_DH_NOSYS; |
db422318 MH |
419 | if (sdev->sdev_state == SDEV_OFFLINE) |
420 | err = SCSI_DH_DEV_OFFLINED; | |
a6a8d9f8 CS |
421 | spin_unlock_irqrestore(q->queue_lock, flags); |
422 | ||
db422318 MH |
423 | if (err) { |
424 | if (fn) | |
425 | fn(data, err); | |
0b839357 | 426 | goto out; |
db422318 | 427 | } |
a6a8d9f8 CS |
428 | |
429 | if (scsi_dh->activate) | |
3ae31f6a | 430 | err = scsi_dh->activate(sdev, fn, data); |
0b839357 MS |
431 | out: |
432 | put_device(dev); | |
a6a8d9f8 CS |
433 | return err; |
434 | } | |
435 | EXPORT_SYMBOL_GPL(scsi_dh_activate); | |
436 | ||
18ee70c9 CS |
437 | /* |
438 | * scsi_dh_set_params - set the parameters for the device as per the | |
439 | * string specified in params. | |
440 | * @q - Request queue that is associated with the scsi_device for | |
441 | * which the parameters to be set. | |
442 | * @params - parameters in the following format | |
443 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
444 | * for example, string for 2 parameters with value 10 and 21 | |
445 | * is specified as "2\010\021\0". | |
446 | */ | |
447 | int scsi_dh_set_params(struct request_queue *q, const char *params) | |
448 | { | |
449 | int err = -SCSI_DH_NOSYS; | |
450 | unsigned long flags; | |
451 | struct scsi_device *sdev; | |
452 | struct scsi_device_handler *scsi_dh = NULL; | |
453 | ||
454 | spin_lock_irqsave(q->queue_lock, flags); | |
455 | sdev = q->queuedata; | |
456 | if (sdev && sdev->scsi_dh_data) | |
457 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
458 | if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) | |
459 | err = 0; | |
460 | spin_unlock_irqrestore(q->queue_lock, flags); | |
461 | ||
462 | if (err) | |
463 | return err; | |
464 | err = scsi_dh->set_params(sdev, params); | |
465 | put_device(&sdev->sdev_gendev); | |
466 | return err; | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); | |
469 | ||
ae11b1b3 | 470 | /* |
2a9ab40f | 471 | * scsi_dh_attach - Attach device handler |
7e8a74b1 MS |
472 | * @q - Request queue that is associated with the scsi_device |
473 | * the handler should be attached to | |
ae11b1b3 HR |
474 | * @name - name of the handler to attach |
475 | */ | |
476 | int scsi_dh_attach(struct request_queue *q, const char *name) | |
477 | { | |
478 | unsigned long flags; | |
479 | struct scsi_device *sdev; | |
480 | struct scsi_device_handler *scsi_dh; | |
481 | int err = 0; | |
482 | ||
566079c8 | 483 | scsi_dh = scsi_dh_lookup(name); |
ae11b1b3 HR |
484 | if (!scsi_dh) |
485 | return -EINVAL; | |
486 | ||
487 | spin_lock_irqsave(q->queue_lock, flags); | |
488 | sdev = q->queuedata; | |
489 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
490 | err = -ENODEV; | |
491 | spin_unlock_irqrestore(q->queue_lock, flags); | |
492 | ||
1bab0de0 CH |
493 | if (err) |
494 | return err; | |
ae11b1b3 HR |
495 | |
496 | if (sdev->scsi_dh_data) { | |
1bab0de0 CH |
497 | if (sdev->scsi_dh_data->scsi_dh != scsi_dh) |
498 | err = -EBUSY; | |
499 | goto out_put_device; | |
ae11b1b3 | 500 | } |
1bab0de0 CH |
501 | |
502 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
503 | ||
504 | out_put_device: | |
ae11b1b3 | 505 | put_device(&sdev->sdev_gendev); |
1bab0de0 | 506 | return err; |
ae11b1b3 | 507 | } |
1bab0de0 | 508 | EXPORT_SYMBOL_GPL(scsi_dh_attach); |
ae11b1b3 | 509 | |
7e8a74b1 MS |
510 | /* |
511 | * scsi_dh_attached_handler_name - Get attached device handler's name | |
512 | * @q - Request queue that is associated with the scsi_device | |
513 | * that may have a device handler attached | |
514 | * @gfp - the GFP mask used in the kmalloc() call when allocating memory | |
515 | * | |
516 | * Returns name of attached handler, NULL if no handler is attached. | |
517 | * Caller must take care to free the returned string. | |
518 | */ | |
519 | const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) | |
520 | { | |
521 | unsigned long flags; | |
522 | struct scsi_device *sdev; | |
523 | const char *handler_name = NULL; | |
524 | ||
525 | spin_lock_irqsave(q->queue_lock, flags); | |
526 | sdev = q->queuedata; | |
527 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
528 | sdev = NULL; | |
529 | spin_unlock_irqrestore(q->queue_lock, flags); | |
530 | ||
531 | if (!sdev) | |
532 | return NULL; | |
533 | ||
534 | if (sdev->scsi_dh_data) | |
535 | handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); | |
536 | ||
537 | put_device(&sdev->sdev_gendev); | |
538 | return handler_name; | |
539 | } | |
540 | EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); | |
541 | ||
765cbc6d HR |
542 | static struct notifier_block scsi_dh_nb = { |
543 | .notifier_call = scsi_dh_notifier | |
544 | }; | |
545 | ||
546 | static int __init scsi_dh_init(void) | |
547 | { | |
548 | int r; | |
549 | ||
550 | r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb); | |
551 | ||
4c05ae52 HR |
552 | if (!r) |
553 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, | |
554 | scsi_dh_sysfs_attr_add); | |
555 | ||
765cbc6d HR |
556 | return r; |
557 | } | |
558 | ||
559 | static void __exit scsi_dh_exit(void) | |
560 | { | |
4c05ae52 HR |
561 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, |
562 | scsi_dh_sysfs_attr_remove); | |
765cbc6d HR |
563 | bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb); |
564 | } | |
565 | ||
566 | module_init(scsi_dh_init); | |
567 | module_exit(scsi_dh_exit); | |
568 | ||
a6a8d9f8 CS |
569 | MODULE_DESCRIPTION("SCSI device handler"); |
570 | MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>"); | |
571 | MODULE_LICENSE("GPL"); |