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 | ||
32 | static struct scsi_device_handler *get_device_handler(const char *name) | |
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 | ||
6c3633d0 HR |
47 | /* |
48 | * device_handler_match_function - Match a device handler to a device | |
49 | * @sdev - SCSI device to be tested | |
50 | * | |
51 | * Tests @sdev against the match function of all registered device_handler. | |
52 | * Returns the found device handler or NULL if not found. | |
53 | */ | |
54 | static struct scsi_device_handler * | |
55 | device_handler_match_function(struct scsi_device *sdev) | |
56 | { | |
57 | struct scsi_device_handler *tmp_dh, *found_dh = NULL; | |
58 | ||
59 | spin_lock(&list_lock); | |
60 | list_for_each_entry(tmp_dh, &scsi_dh_list, list) { | |
61 | if (tmp_dh->match && tmp_dh->match(sdev)) { | |
62 | found_dh = tmp_dh; | |
63 | break; | |
64 | } | |
65 | } | |
66 | spin_unlock(&list_lock); | |
67 | return found_dh; | |
68 | } | |
69 | ||
7c32c7a2 HR |
70 | /* |
71 | * device_handler_match - Attach a device handler to a device | |
72 | * @scsi_dh - The device handler to match against or NULL | |
73 | * @sdev - SCSI device to be tested against @scsi_dh | |
74 | * | |
75 | * Tests @sdev against the device handler @scsi_dh or against | |
76 | * all registered device_handler if @scsi_dh == NULL. | |
77 | * Returns the found device handler or NULL if not found. | |
78 | */ | |
79 | static struct scsi_device_handler * | |
80 | device_handler_match(struct scsi_device_handler *scsi_dh, | |
81 | struct scsi_device *sdev) | |
82 | { | |
6c3633d0 | 83 | struct scsi_device_handler *found_dh; |
7c32c7a2 | 84 | |
6c3633d0 | 85 | found_dh = device_handler_match_function(sdev); |
7c32c7a2 | 86 | |
940d7faa PJ |
87 | if (scsi_dh && found_dh != scsi_dh) |
88 | found_dh = NULL; | |
7c32c7a2 HR |
89 | |
90 | return found_dh; | |
a6a8d9f8 CS |
91 | } |
92 | ||
93 | /* | |
765cbc6d HR |
94 | * scsi_dh_handler_attach - Attach a device handler to a device |
95 | * @sdev - SCSI device the device handler should attach to | |
96 | * @scsi_dh - The device handler to attach | |
97 | */ | |
98 | static int scsi_dh_handler_attach(struct scsi_device *sdev, | |
99 | struct scsi_device_handler *scsi_dh) | |
100 | { | |
1d520328 | 101 | struct scsi_dh_data *d; |
765cbc6d HR |
102 | |
103 | if (sdev->scsi_dh_data) { | |
104 | if (sdev->scsi_dh_data->scsi_dh != scsi_dh) | |
27c888f0 CH |
105 | return -EBUSY; |
106 | ||
107 | kref_get(&sdev->scsi_dh_data->kref); | |
108 | return 0; | |
109 | } | |
110 | ||
1f12ffa5 CH |
111 | if (!try_module_get(scsi_dh->module)) |
112 | return -EINVAL; | |
27c888f0 | 113 | |
1d520328 CH |
114 | d = scsi_dh->attach(sdev); |
115 | if (IS_ERR(d)) { | |
116 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n", | |
117 | scsi_dh->name, PTR_ERR(d)); | |
1f12ffa5 | 118 | module_put(scsi_dh->module); |
1d520328 | 119 | return PTR_ERR(d); |
6c10db72 | 120 | } |
1f12ffa5 | 121 | |
1d520328 CH |
122 | d->scsi_dh = scsi_dh; |
123 | kref_init(&d->kref); | |
124 | d->sdev = sdev; | |
125 | ||
126 | spin_lock_irq(sdev->request_queue->queue_lock); | |
127 | sdev->scsi_dh_data = d; | |
128 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
129 | return 0; | |
765cbc6d HR |
130 | } |
131 | ||
6c10db72 CS |
132 | static void __detach_handler (struct kref *kref) |
133 | { | |
27c888f0 CH |
134 | struct scsi_dh_data *scsi_dh_data = |
135 | container_of(kref, struct scsi_dh_data, kref); | |
136 | struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; | |
1d520328 CH |
137 | struct scsi_device *sdev = scsi_dh_data->sdev; |
138 | ||
28072ad5 MC |
139 | scsi_dh->detach(sdev); |
140 | ||
1d520328 CH |
141 | spin_lock_irq(sdev->request_queue->queue_lock); |
142 | sdev->scsi_dh_data = NULL; | |
143 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
27c888f0 | 144 | |
1d520328 | 145 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); |
27c888f0 | 146 | module_put(scsi_dh->module); |
6c10db72 CS |
147 | } |
148 | ||
765cbc6d HR |
149 | /* |
150 | * scsi_dh_handler_detach - Detach a device handler from a device | |
151 | * @sdev - SCSI device the device handler should be detached from | |
152 | * @scsi_dh - Device handler to be detached | |
a6a8d9f8 | 153 | * |
765cbc6d | 154 | * Detach from a device handler. If a device handler is specified, |
4c05ae52 | 155 | * only detach if the currently attached handler matches @scsi_dh. |
a6a8d9f8 | 156 | */ |
765cbc6d HR |
157 | static void scsi_dh_handler_detach(struct scsi_device *sdev, |
158 | struct scsi_device_handler *scsi_dh) | |
a6a8d9f8 | 159 | { |
765cbc6d HR |
160 | if (!sdev->scsi_dh_data) |
161 | return; | |
a6a8d9f8 | 162 | |
765cbc6d HR |
163 | if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh) |
164 | return; | |
a6a8d9f8 | 165 | |
765cbc6d HR |
166 | if (!scsi_dh) |
167 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
168 | ||
1f12ffa5 | 169 | if (scsi_dh) |
6c10db72 | 170 | kref_put(&sdev->scsi_dh_data->kref, __detach_handler); |
765cbc6d HR |
171 | } |
172 | ||
4c05ae52 HR |
173 | /* |
174 | * Functions for sysfs attribute 'dh_state' | |
175 | */ | |
176 | static ssize_t | |
177 | store_dh_state(struct device *dev, struct device_attribute *attr, | |
178 | const char *buf, size_t count) | |
179 | { | |
180 | struct scsi_device *sdev = to_scsi_device(dev); | |
181 | struct scsi_device_handler *scsi_dh; | |
182 | int err = -EINVAL; | |
183 | ||
6bc8d2a0 HR |
184 | if (sdev->sdev_state == SDEV_CANCEL || |
185 | sdev->sdev_state == SDEV_DEL) | |
186 | return -ENODEV; | |
187 | ||
4c05ae52 HR |
188 | if (!sdev->scsi_dh_data) { |
189 | /* | |
190 | * Attach to a device handler | |
191 | */ | |
192 | if (!(scsi_dh = get_device_handler(buf))) | |
193 | return err; | |
194 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
195 | } else { | |
196 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
197 | if (!strncmp(buf, "detach", 6)) { | |
198 | /* | |
199 | * Detach from a device handler | |
200 | */ | |
201 | scsi_dh_handler_detach(sdev, scsi_dh); | |
202 | err = 0; | |
203 | } else if (!strncmp(buf, "activate", 8)) { | |
204 | /* | |
205 | * Activate a device handler | |
206 | */ | |
207 | if (scsi_dh->activate) | |
3ae31f6a | 208 | err = scsi_dh->activate(sdev, NULL, NULL); |
4c05ae52 HR |
209 | else |
210 | err = 0; | |
211 | } | |
212 | } | |
213 | ||
214 | return err<0?err:count; | |
215 | } | |
216 | ||
217 | static ssize_t | |
218 | show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) | |
219 | { | |
220 | struct scsi_device *sdev = to_scsi_device(dev); | |
221 | ||
222 | if (!sdev->scsi_dh_data) | |
223 | return snprintf(buf, 20, "detached\n"); | |
224 | ||
225 | return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name); | |
226 | } | |
227 | ||
228 | static struct device_attribute scsi_dh_state_attr = | |
229 | __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, | |
230 | store_dh_state); | |
231 | ||
232 | /* | |
233 | * scsi_dh_sysfs_attr_add - Callback for scsi_init_dh | |
234 | */ | |
235 | static int scsi_dh_sysfs_attr_add(struct device *dev, void *data) | |
236 | { | |
237 | struct scsi_device *sdev; | |
238 | int err; | |
239 | ||
240 | if (!scsi_is_sdev_device(dev)) | |
241 | return 0; | |
242 | ||
243 | sdev = to_scsi_device(dev); | |
244 | ||
245 | err = device_create_file(&sdev->sdev_gendev, | |
246 | &scsi_dh_state_attr); | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | /* | |
252 | * scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh | |
253 | */ | |
254 | static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data) | |
255 | { | |
256 | struct scsi_device *sdev; | |
257 | ||
258 | if (!scsi_is_sdev_device(dev)) | |
259 | return 0; | |
260 | ||
261 | sdev = to_scsi_device(dev); | |
262 | ||
263 | device_remove_file(&sdev->sdev_gendev, | |
264 | &scsi_dh_state_attr); | |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
765cbc6d HR |
269 | /* |
270 | * scsi_dh_notifier - notifier chain callback | |
271 | */ | |
272 | static int scsi_dh_notifier(struct notifier_block *nb, | |
273 | unsigned long action, void *data) | |
274 | { | |
275 | struct device *dev = data; | |
276 | struct scsi_device *sdev; | |
277 | int err = 0; | |
7c32c7a2 | 278 | struct scsi_device_handler *devinfo = NULL; |
765cbc6d HR |
279 | |
280 | if (!scsi_is_sdev_device(dev)) | |
281 | return 0; | |
282 | ||
283 | sdev = to_scsi_device(dev); | |
a6a8d9f8 | 284 | |
765cbc6d | 285 | if (action == BUS_NOTIFY_ADD_DEVICE) { |
5917290c CS |
286 | err = device_create_file(dev, &scsi_dh_state_attr); |
287 | /* don't care about err */ | |
7c32c7a2 | 288 | devinfo = device_handler_match(NULL, sdev); |
5917290c CS |
289 | if (devinfo) |
290 | err = scsi_dh_handler_attach(sdev, devinfo); | |
765cbc6d | 291 | } else if (action == BUS_NOTIFY_DEL_DEVICE) { |
4c05ae52 | 292 | device_remove_file(dev, &scsi_dh_state_attr); |
765cbc6d HR |
293 | scsi_dh_handler_detach(sdev, NULL); |
294 | } | |
765cbc6d | 295 | return err; |
a6a8d9f8 | 296 | } |
a6a8d9f8 | 297 | |
765cbc6d HR |
298 | /* |
299 | * scsi_dh_notifier_add - Callback for scsi_register_device_handler | |
300 | */ | |
301 | static int scsi_dh_notifier_add(struct device *dev, void *data) | |
302 | { | |
303 | struct scsi_device_handler *scsi_dh = data; | |
304 | struct scsi_device *sdev; | |
305 | ||
306 | if (!scsi_is_sdev_device(dev)) | |
307 | return 0; | |
308 | ||
309 | if (!get_device(dev)) | |
310 | return 0; | |
311 | ||
312 | sdev = to_scsi_device(dev); | |
313 | ||
314 | if (device_handler_match(scsi_dh, sdev)) | |
315 | scsi_dh_handler_attach(sdev, scsi_dh); | |
316 | ||
317 | put_device(dev); | |
318 | ||
319 | return 0; | |
320 | } | |
321 | ||
322 | /* | |
323 | * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler | |
324 | */ | |
a6a8d9f8 CS |
325 | static int scsi_dh_notifier_remove(struct device *dev, void *data) |
326 | { | |
327 | struct scsi_device_handler *scsi_dh = data; | |
765cbc6d HR |
328 | struct scsi_device *sdev; |
329 | ||
330 | if (!scsi_is_sdev_device(dev)) | |
331 | return 0; | |
332 | ||
333 | if (!get_device(dev)) | |
334 | return 0; | |
335 | ||
336 | sdev = to_scsi_device(dev); | |
337 | ||
338 | scsi_dh_handler_detach(sdev, scsi_dh); | |
339 | ||
340 | put_device(dev); | |
a6a8d9f8 | 341 | |
a6a8d9f8 CS |
342 | return 0; |
343 | } | |
344 | ||
765cbc6d HR |
345 | /* |
346 | * scsi_register_device_handler - register a device handler personality | |
347 | * module. | |
348 | * @scsi_dh - device handler to be registered. | |
349 | * | |
350 | * Returns 0 on success, -EBUSY if handler already registered. | |
351 | */ | |
352 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) | |
353 | { | |
940d7faa | 354 | |
765cbc6d HR |
355 | if (get_device_handler(scsi_dh->name)) |
356 | return -EBUSY; | |
357 | ||
1f12ffa5 CH |
358 | if (!scsi_dh->attach || !scsi_dh->detach) |
359 | return -EINVAL; | |
360 | ||
765cbc6d HR |
361 | spin_lock(&list_lock); |
362 | list_add(&scsi_dh->list, &scsi_dh_list); | |
363 | spin_unlock(&list_lock); | |
940d7faa | 364 | |
765cbc6d HR |
365 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add); |
366 | printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); | |
367 | ||
368 | return SCSI_DH_OK; | |
369 | } | |
370 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); | |
371 | ||
a6a8d9f8 CS |
372 | /* |
373 | * scsi_unregister_device_handler - register a device handler personality | |
374 | * module. | |
375 | * @scsi_dh - device handler to be unregistered. | |
376 | * | |
377 | * Returns 0 on success, -ENODEV if handler not registered. | |
378 | */ | |
379 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) | |
380 | { | |
7c32c7a2 | 381 | |
765cbc6d HR |
382 | if (!get_device_handler(scsi_dh->name)) |
383 | return -ENODEV; | |
a6a8d9f8 CS |
384 | |
385 | bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, | |
765cbc6d HR |
386 | scsi_dh_notifier_remove); |
387 | ||
a6a8d9f8 CS |
388 | spin_lock(&list_lock); |
389 | list_del(&scsi_dh->list); | |
390 | spin_unlock(&list_lock); | |
765cbc6d | 391 | printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |
a6a8d9f8 | 392 | |
765cbc6d | 393 | return SCSI_DH_OK; |
a6a8d9f8 CS |
394 | } |
395 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); | |
396 | ||
397 | /* | |
398 | * scsi_dh_activate - activate the path associated with the scsi_device | |
399 | * corresponding to the given request queue. | |
3ae31f6a CS |
400 | * Returns immediately without waiting for activation to be completed. |
401 | * @q - Request queue that is associated with the scsi_device to be | |
402 | * activated. | |
403 | * @fn - Function to be called upon completion of the activation. | |
404 | * Function fn is called with data (below) and the error code. | |
405 | * Function fn may be called from the same calling context. So, | |
406 | * do not hold the lock in the caller which may be needed in fn. | |
407 | * @data - data passed to the function fn upon completion. | |
408 | * | |
a6a8d9f8 | 409 | */ |
3ae31f6a | 410 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
a6a8d9f8 CS |
411 | { |
412 | int err = 0; | |
413 | unsigned long flags; | |
414 | struct scsi_device *sdev; | |
415 | struct scsi_device_handler *scsi_dh = NULL; | |
0b839357 | 416 | struct device *dev = NULL; |
a6a8d9f8 CS |
417 | |
418 | spin_lock_irqsave(q->queue_lock, flags); | |
419 | sdev = q->queuedata; | |
a18a920c MB |
420 | if (!sdev) { |
421 | spin_unlock_irqrestore(q->queue_lock, flags); | |
422 | err = SCSI_DH_NOSYS; | |
423 | if (fn) | |
424 | fn(data, err); | |
425 | return err; | |
426 | } | |
427 | ||
428 | if (sdev->scsi_dh_data) | |
a6a8d9f8 | 429 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
0b839357 MS |
430 | dev = get_device(&sdev->sdev_gendev); |
431 | if (!scsi_dh || !dev || | |
db422318 MH |
432 | sdev->sdev_state == SDEV_CANCEL || |
433 | sdev->sdev_state == SDEV_DEL) | |
a6a8d9f8 | 434 | err = SCSI_DH_NOSYS; |
db422318 MH |
435 | if (sdev->sdev_state == SDEV_OFFLINE) |
436 | err = SCSI_DH_DEV_OFFLINED; | |
a6a8d9f8 CS |
437 | spin_unlock_irqrestore(q->queue_lock, flags); |
438 | ||
db422318 MH |
439 | if (err) { |
440 | if (fn) | |
441 | fn(data, err); | |
0b839357 | 442 | goto out; |
db422318 | 443 | } |
a6a8d9f8 CS |
444 | |
445 | if (scsi_dh->activate) | |
3ae31f6a | 446 | err = scsi_dh->activate(sdev, fn, data); |
0b839357 MS |
447 | out: |
448 | put_device(dev); | |
a6a8d9f8 CS |
449 | return err; |
450 | } | |
451 | EXPORT_SYMBOL_GPL(scsi_dh_activate); | |
452 | ||
18ee70c9 CS |
453 | /* |
454 | * scsi_dh_set_params - set the parameters for the device as per the | |
455 | * string specified in params. | |
456 | * @q - Request queue that is associated with the scsi_device for | |
457 | * which the parameters to be set. | |
458 | * @params - parameters in the following format | |
459 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
460 | * for example, string for 2 parameters with value 10 and 21 | |
461 | * is specified as "2\010\021\0". | |
462 | */ | |
463 | int scsi_dh_set_params(struct request_queue *q, const char *params) | |
464 | { | |
465 | int err = -SCSI_DH_NOSYS; | |
466 | unsigned long flags; | |
467 | struct scsi_device *sdev; | |
468 | struct scsi_device_handler *scsi_dh = NULL; | |
469 | ||
470 | spin_lock_irqsave(q->queue_lock, flags); | |
471 | sdev = q->queuedata; | |
472 | if (sdev && sdev->scsi_dh_data) | |
473 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
474 | if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) | |
475 | err = 0; | |
476 | spin_unlock_irqrestore(q->queue_lock, flags); | |
477 | ||
478 | if (err) | |
479 | return err; | |
480 | err = scsi_dh->set_params(sdev, params); | |
481 | put_device(&sdev->sdev_gendev); | |
482 | return err; | |
483 | } | |
484 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); | |
485 | ||
a6a8d9f8 CS |
486 | /* |
487 | * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for | |
488 | * the given name. FALSE(0) otherwise. | |
489 | * @name - name of the device handler. | |
490 | */ | |
491 | int scsi_dh_handler_exist(const char *name) | |
492 | { | |
493 | return (get_device_handler(name) != NULL); | |
494 | } | |
495 | EXPORT_SYMBOL_GPL(scsi_dh_handler_exist); | |
496 | ||
ae11b1b3 | 497 | /* |
2a9ab40f | 498 | * scsi_dh_attach - Attach device handler |
7e8a74b1 MS |
499 | * @q - Request queue that is associated with the scsi_device |
500 | * the handler should be attached to | |
ae11b1b3 HR |
501 | * @name - name of the handler to attach |
502 | */ | |
503 | int scsi_dh_attach(struct request_queue *q, const char *name) | |
504 | { | |
505 | unsigned long flags; | |
506 | struct scsi_device *sdev; | |
507 | struct scsi_device_handler *scsi_dh; | |
508 | int err = 0; | |
509 | ||
510 | scsi_dh = get_device_handler(name); | |
511 | if (!scsi_dh) | |
512 | return -EINVAL; | |
513 | ||
514 | spin_lock_irqsave(q->queue_lock, flags); | |
515 | sdev = q->queuedata; | |
516 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
517 | err = -ENODEV; | |
518 | spin_unlock_irqrestore(q->queue_lock, flags); | |
519 | ||
520 | if (!err) { | |
521 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
ae11b1b3 HR |
522 | put_device(&sdev->sdev_gendev); |
523 | } | |
524 | return err; | |
525 | } | |
526 | EXPORT_SYMBOL_GPL(scsi_dh_attach); | |
527 | ||
528 | /* | |
2a9ab40f | 529 | * scsi_dh_detach - Detach device handler |
7e8a74b1 MS |
530 | * @q - Request queue that is associated with the scsi_device |
531 | * the handler should be detached from | |
ae11b1b3 HR |
532 | * |
533 | * This function will detach the device handler only | |
534 | * if the sdev is not part of the internal list, ie | |
535 | * if it has been attached manually. | |
536 | */ | |
537 | void scsi_dh_detach(struct request_queue *q) | |
538 | { | |
539 | unsigned long flags; | |
540 | struct scsi_device *sdev; | |
541 | struct scsi_device_handler *scsi_dh = NULL; | |
542 | ||
543 | spin_lock_irqsave(q->queue_lock, flags); | |
544 | sdev = q->queuedata; | |
545 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
546 | sdev = NULL; | |
547 | spin_unlock_irqrestore(q->queue_lock, flags); | |
548 | ||
549 | if (!sdev) | |
550 | return; | |
551 | ||
552 | if (sdev->scsi_dh_data) { | |
ae11b1b3 | 553 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
6c10db72 | 554 | scsi_dh_handler_detach(sdev, scsi_dh); |
ae11b1b3 HR |
555 | } |
556 | put_device(&sdev->sdev_gendev); | |
557 | } | |
558 | EXPORT_SYMBOL_GPL(scsi_dh_detach); | |
559 | ||
7e8a74b1 MS |
560 | /* |
561 | * scsi_dh_attached_handler_name - Get attached device handler's name | |
562 | * @q - Request queue that is associated with the scsi_device | |
563 | * that may have a device handler attached | |
564 | * @gfp - the GFP mask used in the kmalloc() call when allocating memory | |
565 | * | |
566 | * Returns name of attached handler, NULL if no handler is attached. | |
567 | * Caller must take care to free the returned string. | |
568 | */ | |
569 | const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) | |
570 | { | |
571 | unsigned long flags; | |
572 | struct scsi_device *sdev; | |
573 | const char *handler_name = NULL; | |
574 | ||
575 | spin_lock_irqsave(q->queue_lock, flags); | |
576 | sdev = q->queuedata; | |
577 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
578 | sdev = NULL; | |
579 | spin_unlock_irqrestore(q->queue_lock, flags); | |
580 | ||
581 | if (!sdev) | |
582 | return NULL; | |
583 | ||
584 | if (sdev->scsi_dh_data) | |
585 | handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); | |
586 | ||
587 | put_device(&sdev->sdev_gendev); | |
588 | return handler_name; | |
589 | } | |
590 | EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); | |
591 | ||
765cbc6d HR |
592 | static struct notifier_block scsi_dh_nb = { |
593 | .notifier_call = scsi_dh_notifier | |
594 | }; | |
595 | ||
596 | static int __init scsi_dh_init(void) | |
597 | { | |
598 | int r; | |
599 | ||
600 | r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb); | |
601 | ||
4c05ae52 HR |
602 | if (!r) |
603 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, | |
604 | scsi_dh_sysfs_attr_add); | |
605 | ||
765cbc6d HR |
606 | return r; |
607 | } | |
608 | ||
609 | static void __exit scsi_dh_exit(void) | |
610 | { | |
4c05ae52 HR |
611 | bus_for_each_dev(&scsi_bus_type, NULL, NULL, |
612 | scsi_dh_sysfs_attr_remove); | |
765cbc6d HR |
613 | bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb); |
614 | } | |
615 | ||
616 | module_init(scsi_dh_init); | |
617 | module_exit(scsi_dh_exit); | |
618 | ||
a6a8d9f8 CS |
619 | MODULE_DESCRIPTION("SCSI device handler"); |
620 | MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>"); | |
621 | MODULE_LICENSE("GPL"); |