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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * multipath.c : Multiple Devices driver for Linux | |
3 | * | |
4 | * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat | |
5 | * | |
6 | * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman | |
7 | * | |
8 | * MULTIPATH management functions. | |
9 | * | |
10 | * derived from raid1.c. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2, or (at your option) | |
15 | * any later version. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * (for example /usr/src/linux/COPYING); if not, write to the Free | |
19 | * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | #include <linux/module.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/spinlock.h> | |
25 | #include <linux/raid/multipath.h> | |
26 | #include <linux/buffer_head.h> | |
27 | #include <asm/atomic.h> | |
28 | ||
29 | #define MAJOR_NR MD_MAJOR | |
30 | #define MD_DRIVER | |
31 | #define MD_PERSONALITY | |
32 | ||
33 | #define MAX_WORK_PER_DISK 128 | |
34 | ||
35 | #define NR_RESERVED_BUFS 32 | |
36 | ||
37 | ||
1da177e4 LT |
38 | static int multipath_map (multipath_conf_t *conf) |
39 | { | |
40 | int i, disks = conf->raid_disks; | |
41 | ||
42 | /* | |
43 | * Later we do read balancing on the read side | |
44 | * now we use the first available disk. | |
45 | */ | |
46 | ||
47 | rcu_read_lock(); | |
48 | for (i = 0; i < disks; i++) { | |
d6065f7b | 49 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 | 50 | if (rdev && test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
51 | atomic_inc(&rdev->nr_pending); |
52 | rcu_read_unlock(); | |
53 | return i; | |
54 | } | |
55 | } | |
56 | rcu_read_unlock(); | |
57 | ||
58 | printk(KERN_ERR "multipath_map(): no more operational IO paths?\n"); | |
59 | return (-1); | |
60 | } | |
61 | ||
62 | static void multipath_reschedule_retry (struct multipath_bh *mp_bh) | |
63 | { | |
64 | unsigned long flags; | |
65 | mddev_t *mddev = mp_bh->mddev; | |
66 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
67 | ||
68 | spin_lock_irqsave(&conf->device_lock, flags); | |
69 | list_add(&mp_bh->retry_list, &conf->retry_list); | |
70 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
71 | md_wakeup_thread(mddev->thread); | |
72 | } | |
73 | ||
74 | ||
75 | /* | |
76 | * multipath_end_bh_io() is called when we have finished servicing a multipathed | |
77 | * operation and are ready to return a success/failure code to the buffer | |
78 | * cache layer. | |
79 | */ | |
80 | static void multipath_end_bh_io (struct multipath_bh *mp_bh, int err) | |
81 | { | |
82 | struct bio *bio = mp_bh->master_bio; | |
83 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); | |
84 | ||
6712ecf8 | 85 | bio_endio(bio, err); |
1da177e4 LT |
86 | mempool_free(mp_bh, conf->pool); |
87 | } | |
88 | ||
6712ecf8 | 89 | static void multipath_end_request(struct bio *bio, int error) |
1da177e4 LT |
90 | { |
91 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
92 | struct multipath_bh * mp_bh = (struct multipath_bh *)(bio->bi_private); | |
93 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); | |
94 | mdk_rdev_t *rdev = conf->multipaths[mp_bh->path].rdev; | |
95 | ||
1da177e4 LT |
96 | if (uptodate) |
97 | multipath_end_bh_io(mp_bh, 0); | |
98 | else if (!bio_rw_ahead(bio)) { | |
99 | /* | |
100 | * oops, IO error: | |
101 | */ | |
102 | char b[BDEVNAME_SIZE]; | |
103 | md_error (mp_bh->mddev, rdev); | |
104 | printk(KERN_ERR "multipath: %s: rescheduling sector %llu\n", | |
105 | bdevname(rdev->bdev,b), | |
106 | (unsigned long long)bio->bi_sector); | |
107 | multipath_reschedule_retry(mp_bh); | |
108 | } else | |
109 | multipath_end_bh_io(mp_bh, error); | |
110 | rdev_dec_pending(rdev, conf->mddev); | |
1da177e4 LT |
111 | } |
112 | ||
113 | static void unplug_slaves(mddev_t *mddev) | |
114 | { | |
115 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
116 | int i; | |
117 | ||
118 | rcu_read_lock(); | |
119 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 120 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 N |
121 | if (rdev && !test_bit(Faulty, &rdev->flags) |
122 | && atomic_read(&rdev->nr_pending)) { | |
165125e1 | 123 | struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
1da177e4 LT |
124 | |
125 | atomic_inc(&rdev->nr_pending); | |
126 | rcu_read_unlock(); | |
127 | ||
128 | if (r_queue->unplug_fn) | |
129 | r_queue->unplug_fn(r_queue); | |
130 | ||
131 | rdev_dec_pending(rdev, mddev); | |
132 | rcu_read_lock(); | |
133 | } | |
134 | } | |
135 | rcu_read_unlock(); | |
136 | } | |
137 | ||
165125e1 | 138 | static void multipath_unplug(struct request_queue *q) |
1da177e4 LT |
139 | { |
140 | unplug_slaves(q->queuedata); | |
141 | } | |
142 | ||
143 | ||
165125e1 | 144 | static int multipath_make_request (struct request_queue *q, struct bio * bio) |
1da177e4 LT |
145 | { |
146 | mddev_t *mddev = q->queuedata; | |
147 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
148 | struct multipath_bh * mp_bh; | |
149 | struct multipath_info *multipath; | |
a362357b | 150 | const int rw = bio_data_dir(bio); |
1da177e4 | 151 | |
e5dcdd80 | 152 | if (unlikely(bio_barrier(bio))) { |
6712ecf8 | 153 | bio_endio(bio, -EOPNOTSUPP); |
e5dcdd80 N |
154 | return 0; |
155 | } | |
156 | ||
1da177e4 LT |
157 | mp_bh = mempool_alloc(conf->pool, GFP_NOIO); |
158 | ||
159 | mp_bh->master_bio = bio; | |
160 | mp_bh->mddev = mddev; | |
161 | ||
a362357b JA |
162 | disk_stat_inc(mddev->gendisk, ios[rw]); |
163 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); | |
1da177e4 LT |
164 | |
165 | mp_bh->path = multipath_map(conf); | |
166 | if (mp_bh->path < 0) { | |
6712ecf8 | 167 | bio_endio(bio, -EIO); |
1da177e4 LT |
168 | mempool_free(mp_bh, conf->pool); |
169 | return 0; | |
170 | } | |
171 | multipath = conf->multipaths + mp_bh->path; | |
172 | ||
173 | mp_bh->bio = *bio; | |
174 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; | |
175 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; | |
176 | mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST); | |
177 | mp_bh->bio.bi_end_io = multipath_end_request; | |
178 | mp_bh->bio.bi_private = mp_bh; | |
179 | generic_make_request(&mp_bh->bio); | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) | |
184 | { | |
185 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
186 | int i; | |
187 | ||
188 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, | |
189 | conf->working_disks); | |
190 | for (i = 0; i < conf->raid_disks; i++) | |
191 | seq_printf (seq, "%s", | |
192 | conf->multipaths[i].rdev && | |
b2d444d7 | 193 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
194 | seq_printf (seq, "]"); |
195 | } | |
196 | ||
0d129228 N |
197 | static int multipath_congested(void *data, int bits) |
198 | { | |
199 | mddev_t *mddev = data; | |
200 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
201 | int i, ret = 0; | |
202 | ||
203 | rcu_read_lock(); | |
204 | for (i = 0; i < mddev->raid_disks ; i++) { | |
205 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); | |
206 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 207 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
208 | |
209 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
210 | /* Just like multipath_map, we just check the | |
211 | * first available device | |
212 | */ | |
213 | break; | |
214 | } | |
215 | } | |
216 | rcu_read_unlock(); | |
217 | return ret; | |
218 | } | |
1da177e4 LT |
219 | |
220 | /* | |
221 | * Careful, this can execute in IRQ contexts as well! | |
222 | */ | |
223 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) | |
224 | { | |
225 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
226 | ||
227 | if (conf->working_disks <= 1) { | |
228 | /* | |
229 | * Uh oh, we can do nothing if this is our last path, but | |
230 | * first check if this is a queued request for a device | |
231 | * which has just failed. | |
232 | */ | |
233 | printk(KERN_ALERT | |
234 | "multipath: only one IO path left and IO error.\n"); | |
235 | /* leave it active... it's all we have */ | |
236 | } else { | |
237 | /* | |
238 | * Mark disk as unusable | |
239 | */ | |
b2d444d7 | 240 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 241 | char b[BDEVNAME_SIZE]; |
b2d444d7 N |
242 | clear_bit(In_sync, &rdev->flags); |
243 | set_bit(Faulty, &rdev->flags); | |
850b2b42 | 244 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
1da177e4 | 245 | conf->working_disks--; |
750a8f3e | 246 | mddev->degraded++; |
1da177e4 LT |
247 | printk(KERN_ALERT "multipath: IO failure on %s," |
248 | " disabling IO path. \n Operation continuing" | |
249 | " on %d IO paths.\n", | |
250 | bdevname (rdev->bdev,b), | |
251 | conf->working_disks); | |
252 | } | |
253 | } | |
254 | } | |
255 | ||
256 | static void print_multipath_conf (multipath_conf_t *conf) | |
257 | { | |
258 | int i; | |
259 | struct multipath_info *tmp; | |
260 | ||
261 | printk("MULTIPATH conf printout:\n"); | |
262 | if (!conf) { | |
263 | printk("(conf==NULL)\n"); | |
264 | return; | |
265 | } | |
266 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
267 | conf->raid_disks); | |
268 | ||
269 | for (i = 0; i < conf->raid_disks; i++) { | |
270 | char b[BDEVNAME_SIZE]; | |
271 | tmp = conf->multipaths + i; | |
272 | if (tmp->rdev) | |
273 | printk(" disk%d, o:%d, dev:%s\n", | |
b2d444d7 | 274 | i,!test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
275 | bdevname(tmp->rdev->bdev,b)); |
276 | } | |
277 | } | |
278 | ||
279 | ||
280 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
281 | { | |
282 | multipath_conf_t *conf = mddev->private; | |
352d768b | 283 | struct request_queue *q; |
1da177e4 LT |
284 | int found = 0; |
285 | int path; | |
286 | struct multipath_info *p; | |
287 | ||
288 | print_multipath_conf(conf); | |
289 | ||
290 | for (path=0; path<mddev->raid_disks; path++) | |
291 | if ((p=conf->multipaths+path)->rdev == NULL) { | |
352d768b JJ |
292 | q = rdev->bdev->bd_disk->queue; |
293 | blk_queue_stack_limits(mddev->queue, q); | |
1da177e4 LT |
294 | |
295 | /* as we don't honour merge_bvec_fn, we must never risk | |
296 | * violating it, so limit ->max_sector to one PAGE, as | |
297 | * a one page request is never in violation. | |
298 | * (Note: it is very unlikely that a device with | |
299 | * merge_bvec_fn will be involved in multipath.) | |
300 | */ | |
352d768b | 301 | if (q->merge_bvec_fn && |
1da177e4 LT |
302 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) |
303 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
304 | ||
305 | conf->working_disks++; | |
750a8f3e | 306 | mddev->degraded--; |
1da177e4 | 307 | rdev->raid_disk = path; |
b2d444d7 | 308 | set_bit(In_sync, &rdev->flags); |
d6065f7b | 309 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
310 | found = 1; |
311 | } | |
312 | ||
313 | print_multipath_conf(conf); | |
314 | return found; | |
315 | } | |
316 | ||
317 | static int multipath_remove_disk(mddev_t *mddev, int number) | |
318 | { | |
319 | multipath_conf_t *conf = mddev->private; | |
320 | int err = 0; | |
321 | mdk_rdev_t *rdev; | |
322 | struct multipath_info *p = conf->multipaths + number; | |
323 | ||
324 | print_multipath_conf(conf); | |
325 | ||
326 | rdev = p->rdev; | |
327 | if (rdev) { | |
b2d444d7 | 328 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
329 | atomic_read(&rdev->nr_pending)) { |
330 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" " but is still operational!\n", number); | |
331 | err = -EBUSY; | |
332 | goto abort; | |
333 | } | |
334 | p->rdev = NULL; | |
fbd568a3 | 335 | synchronize_rcu(); |
1da177e4 LT |
336 | if (atomic_read(&rdev->nr_pending)) { |
337 | /* lost the race, try later */ | |
338 | err = -EBUSY; | |
339 | p->rdev = rdev; | |
340 | } | |
341 | } | |
342 | abort: | |
343 | ||
344 | print_multipath_conf(conf); | |
345 | return err; | |
346 | } | |
347 | ||
348 | ||
349 | ||
350 | /* | |
351 | * This is a kernel thread which: | |
352 | * | |
353 | * 1. Retries failed read operations on working multipaths. | |
354 | * 2. Updates the raid superblock when problems encounter. | |
355 | * 3. Performs writes following reads for array syncronising. | |
356 | */ | |
357 | ||
358 | static void multipathd (mddev_t *mddev) | |
359 | { | |
360 | struct multipath_bh *mp_bh; | |
361 | struct bio *bio; | |
362 | unsigned long flags; | |
363 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
364 | struct list_head *head = &conf->retry_list; | |
365 | ||
366 | md_check_recovery(mddev); | |
367 | for (;;) { | |
368 | char b[BDEVNAME_SIZE]; | |
369 | spin_lock_irqsave(&conf->device_lock, flags); | |
370 | if (list_empty(head)) | |
371 | break; | |
372 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); | |
373 | list_del(head->prev); | |
374 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
375 | ||
376 | bio = &mp_bh->bio; | |
377 | bio->bi_sector = mp_bh->master_bio->bi_sector; | |
378 | ||
379 | if ((mp_bh->path = multipath_map (conf))<0) { | |
380 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" | |
381 | " error for block %llu\n", | |
382 | bdevname(bio->bi_bdev,b), | |
383 | (unsigned long long)bio->bi_sector); | |
384 | multipath_end_bh_io(mp_bh, -EIO); | |
385 | } else { | |
386 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" | |
387 | " to another IO path\n", | |
388 | bdevname(bio->bi_bdev,b), | |
389 | (unsigned long long)bio->bi_sector); | |
390 | *bio = *(mp_bh->master_bio); | |
391 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; | |
392 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; | |
393 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); | |
394 | bio->bi_end_io = multipath_end_request; | |
395 | bio->bi_private = mp_bh; | |
396 | generic_make_request(bio); | |
397 | } | |
398 | } | |
399 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
400 | } | |
401 | ||
402 | static int multipath_run (mddev_t *mddev) | |
403 | { | |
404 | multipath_conf_t *conf; | |
405 | int disk_idx; | |
406 | struct multipath_info *disk; | |
407 | mdk_rdev_t *rdev; | |
408 | struct list_head *tmp; | |
409 | ||
410 | if (mddev->level != LEVEL_MULTIPATH) { | |
411 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", | |
412 | mdname(mddev), mddev->level); | |
413 | goto out; | |
414 | } | |
415 | /* | |
416 | * copy the already verified devices into our private MULTIPATH | |
417 | * bookkeeping area. [whatever we allocate in multipath_run(), | |
418 | * should be freed in multipath_stop()] | |
419 | */ | |
420 | ||
9ffae0cf | 421 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
1da177e4 LT |
422 | mddev->private = conf; |
423 | if (!conf) { | |
424 | printk(KERN_ERR | |
425 | "multipath: couldn't allocate memory for %s\n", | |
426 | mdname(mddev)); | |
427 | goto out; | |
428 | } | |
1da177e4 | 429 | |
9ffae0cf | 430 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
1da177e4 LT |
431 | GFP_KERNEL); |
432 | if (!conf->multipaths) { | |
433 | printk(KERN_ERR | |
434 | "multipath: couldn't allocate memory for %s\n", | |
435 | mdname(mddev)); | |
436 | goto out_free_conf; | |
437 | } | |
1da177e4 | 438 | |
1da177e4 LT |
439 | conf->working_disks = 0; |
440 | ITERATE_RDEV(mddev,rdev,tmp) { | |
441 | disk_idx = rdev->raid_disk; | |
442 | if (disk_idx < 0 || | |
443 | disk_idx >= mddev->raid_disks) | |
444 | continue; | |
445 | ||
446 | disk = conf->multipaths + disk_idx; | |
447 | disk->rdev = rdev; | |
448 | ||
449 | blk_queue_stack_limits(mddev->queue, | |
450 | rdev->bdev->bd_disk->queue); | |
451 | /* as we don't honour merge_bvec_fn, we must never risk | |
452 | * violating it, not that we ever expect a device with | |
453 | * a merge_bvec_fn to be involved in multipath */ | |
454 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
455 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
456 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
457 | ||
b2d444d7 | 458 | if (!test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
459 | conf->working_disks++; |
460 | } | |
461 | ||
462 | conf->raid_disks = mddev->raid_disks; | |
1da177e4 LT |
463 | conf->mddev = mddev; |
464 | spin_lock_init(&conf->device_lock); | |
465 | INIT_LIST_HEAD(&conf->retry_list); | |
466 | ||
467 | if (!conf->working_disks) { | |
468 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", | |
469 | mdname(mddev)); | |
470 | goto out_free_conf; | |
471 | } | |
2e333e89 | 472 | mddev->degraded = conf->raid_disks - conf->working_disks; |
1da177e4 | 473 | |
26b6e051 MD |
474 | conf->pool = mempool_create_kzalloc_pool(NR_RESERVED_BUFS, |
475 | sizeof(struct multipath_bh)); | |
1da177e4 LT |
476 | if (conf->pool == NULL) { |
477 | printk(KERN_ERR | |
478 | "multipath: couldn't allocate memory for %s\n", | |
479 | mdname(mddev)); | |
480 | goto out_free_conf; | |
481 | } | |
482 | ||
483 | { | |
484 | mddev->thread = md_register_thread(multipathd, mddev, "%s_multipath"); | |
485 | if (!mddev->thread) { | |
486 | printk(KERN_ERR "multipath: couldn't allocate thread" | |
487 | " for %s\n", mdname(mddev)); | |
488 | goto out_free_conf; | |
489 | } | |
490 | } | |
491 | ||
492 | printk(KERN_INFO | |
493 | "multipath: array %s active with %d out of %d IO paths\n", | |
494 | mdname(mddev), conf->working_disks, mddev->raid_disks); | |
495 | /* | |
496 | * Ok, everything is just fine now | |
497 | */ | |
498 | mddev->array_size = mddev->size; | |
7a5febe9 N |
499 | |
500 | mddev->queue->unplug_fn = multipath_unplug; | |
0d129228 N |
501 | mddev->queue->backing_dev_info.congested_fn = multipath_congested; |
502 | mddev->queue->backing_dev_info.congested_data = mddev; | |
7a5febe9 | 503 | |
1da177e4 LT |
504 | return 0; |
505 | ||
506 | out_free_conf: | |
507 | if (conf->pool) | |
508 | mempool_destroy(conf->pool); | |
990a8baf | 509 | kfree(conf->multipaths); |
1da177e4 LT |
510 | kfree(conf); |
511 | mddev->private = NULL; | |
512 | out: | |
513 | return -EIO; | |
514 | } | |
515 | ||
516 | ||
517 | static int multipath_stop (mddev_t *mddev) | |
518 | { | |
519 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
520 | ||
521 | md_unregister_thread(mddev->thread); | |
522 | mddev->thread = NULL; | |
523 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
524 | mempool_destroy(conf->pool); | |
525 | kfree(conf->multipaths); | |
526 | kfree(conf); | |
527 | mddev->private = NULL; | |
528 | return 0; | |
529 | } | |
530 | ||
2604b703 | 531 | static struct mdk_personality multipath_personality = |
1da177e4 LT |
532 | { |
533 | .name = "multipath", | |
2604b703 | 534 | .level = LEVEL_MULTIPATH, |
1da177e4 LT |
535 | .owner = THIS_MODULE, |
536 | .make_request = multipath_make_request, | |
537 | .run = multipath_run, | |
538 | .stop = multipath_stop, | |
539 | .status = multipath_status, | |
540 | .error_handler = multipath_error, | |
541 | .hot_add_disk = multipath_add_disk, | |
542 | .hot_remove_disk= multipath_remove_disk, | |
543 | }; | |
544 | ||
545 | static int __init multipath_init (void) | |
546 | { | |
2604b703 | 547 | return register_md_personality (&multipath_personality); |
1da177e4 LT |
548 | } |
549 | ||
550 | static void __exit multipath_exit (void) | |
551 | { | |
2604b703 | 552 | unregister_md_personality (&multipath_personality); |
1da177e4 LT |
553 | } |
554 | ||
555 | module_init(multipath_init); | |
556 | module_exit(multipath_exit); | |
557 | MODULE_LICENSE("GPL"); | |
558 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ | |
d9d166c2 | 559 | MODULE_ALIAS("md-multipath"); |
2604b703 | 560 | MODULE_ALIAS("md-level--4"); |