Commit | Line | Data |
---|---|---|
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 | ||
dd0fc66f | 38 | static void *mp_pool_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
39 | { |
40 | struct multipath_bh *mpb; | |
9ffae0cf | 41 | mpb = kzalloc(sizeof(*mpb), gfp_flags); |
1da177e4 LT |
42 | return mpb; |
43 | } | |
44 | ||
45 | static void mp_pool_free(void *mpb, void *data) | |
46 | { | |
47 | kfree(mpb); | |
48 | } | |
49 | ||
50 | static int multipath_map (multipath_conf_t *conf) | |
51 | { | |
52 | int i, disks = conf->raid_disks; | |
53 | ||
54 | /* | |
55 | * Later we do read balancing on the read side | |
56 | * now we use the first available disk. | |
57 | */ | |
58 | ||
59 | rcu_read_lock(); | |
60 | for (i = 0; i < disks; i++) { | |
d6065f7b | 61 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 | 62 | if (rdev && test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
63 | atomic_inc(&rdev->nr_pending); |
64 | rcu_read_unlock(); | |
65 | return i; | |
66 | } | |
67 | } | |
68 | rcu_read_unlock(); | |
69 | ||
70 | printk(KERN_ERR "multipath_map(): no more operational IO paths?\n"); | |
71 | return (-1); | |
72 | } | |
73 | ||
74 | static void multipath_reschedule_retry (struct multipath_bh *mp_bh) | |
75 | { | |
76 | unsigned long flags; | |
77 | mddev_t *mddev = mp_bh->mddev; | |
78 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
79 | ||
80 | spin_lock_irqsave(&conf->device_lock, flags); | |
81 | list_add(&mp_bh->retry_list, &conf->retry_list); | |
82 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
83 | md_wakeup_thread(mddev->thread); | |
84 | } | |
85 | ||
86 | ||
87 | /* | |
88 | * multipath_end_bh_io() is called when we have finished servicing a multipathed | |
89 | * operation and are ready to return a success/failure code to the buffer | |
90 | * cache layer. | |
91 | */ | |
92 | static void multipath_end_bh_io (struct multipath_bh *mp_bh, int err) | |
93 | { | |
94 | struct bio *bio = mp_bh->master_bio; | |
95 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); | |
96 | ||
97 | bio_endio(bio, bio->bi_size, err); | |
98 | mempool_free(mp_bh, conf->pool); | |
99 | } | |
100 | ||
75c96f85 AB |
101 | static int multipath_end_request(struct bio *bio, unsigned int bytes_done, |
102 | int error) | |
1da177e4 LT |
103 | { |
104 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
105 | struct multipath_bh * mp_bh = (struct multipath_bh *)(bio->bi_private); | |
106 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); | |
107 | mdk_rdev_t *rdev = conf->multipaths[mp_bh->path].rdev; | |
108 | ||
109 | if (bio->bi_size) | |
110 | return 1; | |
111 | ||
112 | if (uptodate) | |
113 | multipath_end_bh_io(mp_bh, 0); | |
114 | else if (!bio_rw_ahead(bio)) { | |
115 | /* | |
116 | * oops, IO error: | |
117 | */ | |
118 | char b[BDEVNAME_SIZE]; | |
119 | md_error (mp_bh->mddev, rdev); | |
120 | printk(KERN_ERR "multipath: %s: rescheduling sector %llu\n", | |
121 | bdevname(rdev->bdev,b), | |
122 | (unsigned long long)bio->bi_sector); | |
123 | multipath_reschedule_retry(mp_bh); | |
124 | } else | |
125 | multipath_end_bh_io(mp_bh, error); | |
126 | rdev_dec_pending(rdev, conf->mddev); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | static void unplug_slaves(mddev_t *mddev) | |
131 | { | |
132 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
133 | int i; | |
134 | ||
135 | rcu_read_lock(); | |
136 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 137 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 N |
138 | if (rdev && !test_bit(Faulty, &rdev->flags) |
139 | && atomic_read(&rdev->nr_pending)) { | |
1da177e4 LT |
140 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
141 | ||
142 | atomic_inc(&rdev->nr_pending); | |
143 | rcu_read_unlock(); | |
144 | ||
145 | if (r_queue->unplug_fn) | |
146 | r_queue->unplug_fn(r_queue); | |
147 | ||
148 | rdev_dec_pending(rdev, mddev); | |
149 | rcu_read_lock(); | |
150 | } | |
151 | } | |
152 | rcu_read_unlock(); | |
153 | } | |
154 | ||
155 | static void multipath_unplug(request_queue_t *q) | |
156 | { | |
157 | unplug_slaves(q->queuedata); | |
158 | } | |
159 | ||
160 | ||
161 | static int multipath_make_request (request_queue_t *q, struct bio * bio) | |
162 | { | |
163 | mddev_t *mddev = q->queuedata; | |
164 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
165 | struct multipath_bh * mp_bh; | |
166 | struct multipath_info *multipath; | |
a362357b | 167 | const int rw = bio_data_dir(bio); |
1da177e4 | 168 | |
e5dcdd80 N |
169 | if (unlikely(bio_barrier(bio))) { |
170 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); | |
171 | return 0; | |
172 | } | |
173 | ||
1da177e4 LT |
174 | mp_bh = mempool_alloc(conf->pool, GFP_NOIO); |
175 | ||
176 | mp_bh->master_bio = bio; | |
177 | mp_bh->mddev = mddev; | |
178 | ||
a362357b JA |
179 | disk_stat_inc(mddev->gendisk, ios[rw]); |
180 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); | |
1da177e4 LT |
181 | |
182 | mp_bh->path = multipath_map(conf); | |
183 | if (mp_bh->path < 0) { | |
184 | bio_endio(bio, bio->bi_size, -EIO); | |
185 | mempool_free(mp_bh, conf->pool); | |
186 | return 0; | |
187 | } | |
188 | multipath = conf->multipaths + mp_bh->path; | |
189 | ||
190 | mp_bh->bio = *bio; | |
191 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; | |
192 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; | |
193 | mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST); | |
194 | mp_bh->bio.bi_end_io = multipath_end_request; | |
195 | mp_bh->bio.bi_private = mp_bh; | |
196 | generic_make_request(&mp_bh->bio); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) | |
201 | { | |
202 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
203 | int i; | |
204 | ||
205 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, | |
206 | conf->working_disks); | |
207 | for (i = 0; i < conf->raid_disks; i++) | |
208 | seq_printf (seq, "%s", | |
209 | conf->multipaths[i].rdev && | |
b2d444d7 | 210 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
211 | seq_printf (seq, "]"); |
212 | } | |
213 | ||
214 | static int multipath_issue_flush(request_queue_t *q, struct gendisk *disk, | |
215 | sector_t *error_sector) | |
216 | { | |
217 | mddev_t *mddev = q->queuedata; | |
218 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
219 | int i, ret = 0; | |
220 | ||
221 | rcu_read_lock(); | |
222 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { | |
d6065f7b | 223 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 | 224 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
1da177e4 LT |
225 | struct block_device *bdev = rdev->bdev; |
226 | request_queue_t *r_queue = bdev_get_queue(bdev); | |
227 | ||
228 | if (!r_queue->issue_flush_fn) | |
229 | ret = -EOPNOTSUPP; | |
230 | else { | |
231 | atomic_inc(&rdev->nr_pending); | |
232 | rcu_read_unlock(); | |
233 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, | |
234 | error_sector); | |
235 | rdev_dec_pending(rdev, mddev); | |
236 | rcu_read_lock(); | |
237 | } | |
238 | } | |
239 | } | |
240 | rcu_read_unlock(); | |
241 | return ret; | |
242 | } | |
243 | ||
244 | /* | |
245 | * Careful, this can execute in IRQ contexts as well! | |
246 | */ | |
247 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) | |
248 | { | |
249 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
250 | ||
251 | if (conf->working_disks <= 1) { | |
252 | /* | |
253 | * Uh oh, we can do nothing if this is our last path, but | |
254 | * first check if this is a queued request for a device | |
255 | * which has just failed. | |
256 | */ | |
257 | printk(KERN_ALERT | |
258 | "multipath: only one IO path left and IO error.\n"); | |
259 | /* leave it active... it's all we have */ | |
260 | } else { | |
261 | /* | |
262 | * Mark disk as unusable | |
263 | */ | |
b2d444d7 | 264 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 265 | char b[BDEVNAME_SIZE]; |
b2d444d7 N |
266 | clear_bit(In_sync, &rdev->flags); |
267 | set_bit(Faulty, &rdev->flags); | |
1da177e4 LT |
268 | mddev->sb_dirty = 1; |
269 | conf->working_disks--; | |
270 | printk(KERN_ALERT "multipath: IO failure on %s," | |
271 | " disabling IO path. \n Operation continuing" | |
272 | " on %d IO paths.\n", | |
273 | bdevname (rdev->bdev,b), | |
274 | conf->working_disks); | |
275 | } | |
276 | } | |
277 | } | |
278 | ||
279 | static void print_multipath_conf (multipath_conf_t *conf) | |
280 | { | |
281 | int i; | |
282 | struct multipath_info *tmp; | |
283 | ||
284 | printk("MULTIPATH conf printout:\n"); | |
285 | if (!conf) { | |
286 | printk("(conf==NULL)\n"); | |
287 | return; | |
288 | } | |
289 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
290 | conf->raid_disks); | |
291 | ||
292 | for (i = 0; i < conf->raid_disks; i++) { | |
293 | char b[BDEVNAME_SIZE]; | |
294 | tmp = conf->multipaths + i; | |
295 | if (tmp->rdev) | |
296 | printk(" disk%d, o:%d, dev:%s\n", | |
b2d444d7 | 297 | i,!test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
298 | bdevname(tmp->rdev->bdev,b)); |
299 | } | |
300 | } | |
301 | ||
302 | ||
303 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
304 | { | |
305 | multipath_conf_t *conf = mddev->private; | |
306 | int found = 0; | |
307 | int path; | |
308 | struct multipath_info *p; | |
309 | ||
310 | print_multipath_conf(conf); | |
311 | ||
312 | for (path=0; path<mddev->raid_disks; path++) | |
313 | if ((p=conf->multipaths+path)->rdev == NULL) { | |
314 | blk_queue_stack_limits(mddev->queue, | |
315 | rdev->bdev->bd_disk->queue); | |
316 | ||
317 | /* as we don't honour merge_bvec_fn, we must never risk | |
318 | * violating it, so limit ->max_sector to one PAGE, as | |
319 | * a one page request is never in violation. | |
320 | * (Note: it is very unlikely that a device with | |
321 | * merge_bvec_fn will be involved in multipath.) | |
322 | */ | |
323 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
324 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
325 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
326 | ||
327 | conf->working_disks++; | |
328 | rdev->raid_disk = path; | |
b2d444d7 | 329 | set_bit(In_sync, &rdev->flags); |
d6065f7b | 330 | rcu_assign_pointer(p->rdev, rdev); |
1da177e4 LT |
331 | found = 1; |
332 | } | |
333 | ||
334 | print_multipath_conf(conf); | |
335 | return found; | |
336 | } | |
337 | ||
338 | static int multipath_remove_disk(mddev_t *mddev, int number) | |
339 | { | |
340 | multipath_conf_t *conf = mddev->private; | |
341 | int err = 0; | |
342 | mdk_rdev_t *rdev; | |
343 | struct multipath_info *p = conf->multipaths + number; | |
344 | ||
345 | print_multipath_conf(conf); | |
346 | ||
347 | rdev = p->rdev; | |
348 | if (rdev) { | |
b2d444d7 | 349 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 LT |
350 | atomic_read(&rdev->nr_pending)) { |
351 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" " but is still operational!\n", number); | |
352 | err = -EBUSY; | |
353 | goto abort; | |
354 | } | |
355 | p->rdev = NULL; | |
fbd568a3 | 356 | synchronize_rcu(); |
1da177e4 LT |
357 | if (atomic_read(&rdev->nr_pending)) { |
358 | /* lost the race, try later */ | |
359 | err = -EBUSY; | |
360 | p->rdev = rdev; | |
361 | } | |
362 | } | |
363 | abort: | |
364 | ||
365 | print_multipath_conf(conf); | |
366 | return err; | |
367 | } | |
368 | ||
369 | ||
370 | ||
371 | /* | |
372 | * This is a kernel thread which: | |
373 | * | |
374 | * 1. Retries failed read operations on working multipaths. | |
375 | * 2. Updates the raid superblock when problems encounter. | |
376 | * 3. Performs writes following reads for array syncronising. | |
377 | */ | |
378 | ||
379 | static void multipathd (mddev_t *mddev) | |
380 | { | |
381 | struct multipath_bh *mp_bh; | |
382 | struct bio *bio; | |
383 | unsigned long flags; | |
384 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
385 | struct list_head *head = &conf->retry_list; | |
386 | ||
387 | md_check_recovery(mddev); | |
388 | for (;;) { | |
389 | char b[BDEVNAME_SIZE]; | |
390 | spin_lock_irqsave(&conf->device_lock, flags); | |
391 | if (list_empty(head)) | |
392 | break; | |
393 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); | |
394 | list_del(head->prev); | |
395 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
396 | ||
397 | bio = &mp_bh->bio; | |
398 | bio->bi_sector = mp_bh->master_bio->bi_sector; | |
399 | ||
400 | if ((mp_bh->path = multipath_map (conf))<0) { | |
401 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" | |
402 | " error for block %llu\n", | |
403 | bdevname(bio->bi_bdev,b), | |
404 | (unsigned long long)bio->bi_sector); | |
405 | multipath_end_bh_io(mp_bh, -EIO); | |
406 | } else { | |
407 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" | |
408 | " to another IO path\n", | |
409 | bdevname(bio->bi_bdev,b), | |
410 | (unsigned long long)bio->bi_sector); | |
411 | *bio = *(mp_bh->master_bio); | |
412 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; | |
413 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; | |
414 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); | |
415 | bio->bi_end_io = multipath_end_request; | |
416 | bio->bi_private = mp_bh; | |
417 | generic_make_request(bio); | |
418 | } | |
419 | } | |
420 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
421 | } | |
422 | ||
423 | static int multipath_run (mddev_t *mddev) | |
424 | { | |
425 | multipath_conf_t *conf; | |
426 | int disk_idx; | |
427 | struct multipath_info *disk; | |
428 | mdk_rdev_t *rdev; | |
429 | struct list_head *tmp; | |
430 | ||
431 | if (mddev->level != LEVEL_MULTIPATH) { | |
432 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", | |
433 | mdname(mddev), mddev->level); | |
434 | goto out; | |
435 | } | |
436 | /* | |
437 | * copy the already verified devices into our private MULTIPATH | |
438 | * bookkeeping area. [whatever we allocate in multipath_run(), | |
439 | * should be freed in multipath_stop()] | |
440 | */ | |
441 | ||
9ffae0cf | 442 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
1da177e4 LT |
443 | mddev->private = conf; |
444 | if (!conf) { | |
445 | printk(KERN_ERR | |
446 | "multipath: couldn't allocate memory for %s\n", | |
447 | mdname(mddev)); | |
448 | goto out; | |
449 | } | |
1da177e4 | 450 | |
9ffae0cf | 451 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
1da177e4 LT |
452 | GFP_KERNEL); |
453 | if (!conf->multipaths) { | |
454 | printk(KERN_ERR | |
455 | "multipath: couldn't allocate memory for %s\n", | |
456 | mdname(mddev)); | |
457 | goto out_free_conf; | |
458 | } | |
1da177e4 | 459 | |
1da177e4 LT |
460 | conf->working_disks = 0; |
461 | ITERATE_RDEV(mddev,rdev,tmp) { | |
462 | disk_idx = rdev->raid_disk; | |
463 | if (disk_idx < 0 || | |
464 | disk_idx >= mddev->raid_disks) | |
465 | continue; | |
466 | ||
467 | disk = conf->multipaths + disk_idx; | |
468 | disk->rdev = rdev; | |
469 | ||
470 | blk_queue_stack_limits(mddev->queue, | |
471 | rdev->bdev->bd_disk->queue); | |
472 | /* as we don't honour merge_bvec_fn, we must never risk | |
473 | * violating it, not that we ever expect a device with | |
474 | * a merge_bvec_fn to be involved in multipath */ | |
475 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
476 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
477 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
478 | ||
b2d444d7 | 479 | if (!test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
480 | conf->working_disks++; |
481 | } | |
482 | ||
483 | conf->raid_disks = mddev->raid_disks; | |
484 | mddev->sb_dirty = 1; | |
485 | conf->mddev = mddev; | |
486 | spin_lock_init(&conf->device_lock); | |
487 | INIT_LIST_HEAD(&conf->retry_list); | |
488 | ||
489 | if (!conf->working_disks) { | |
490 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", | |
491 | mdname(mddev)); | |
492 | goto out_free_conf; | |
493 | } | |
494 | mddev->degraded = conf->raid_disks = conf->working_disks; | |
495 | ||
496 | conf->pool = mempool_create(NR_RESERVED_BUFS, | |
497 | mp_pool_alloc, mp_pool_free, | |
498 | NULL); | |
499 | if (conf->pool == NULL) { | |
500 | printk(KERN_ERR | |
501 | "multipath: couldn't allocate memory for %s\n", | |
502 | mdname(mddev)); | |
503 | goto out_free_conf; | |
504 | } | |
505 | ||
506 | { | |
507 | mddev->thread = md_register_thread(multipathd, mddev, "%s_multipath"); | |
508 | if (!mddev->thread) { | |
509 | printk(KERN_ERR "multipath: couldn't allocate thread" | |
510 | " for %s\n", mdname(mddev)); | |
511 | goto out_free_conf; | |
512 | } | |
513 | } | |
514 | ||
515 | printk(KERN_INFO | |
516 | "multipath: array %s active with %d out of %d IO paths\n", | |
517 | mdname(mddev), conf->working_disks, mddev->raid_disks); | |
518 | /* | |
519 | * Ok, everything is just fine now | |
520 | */ | |
521 | mddev->array_size = mddev->size; | |
7a5febe9 N |
522 | |
523 | mddev->queue->unplug_fn = multipath_unplug; | |
524 | mddev->queue->issue_flush_fn = multipath_issue_flush; | |
525 | ||
1da177e4 LT |
526 | return 0; |
527 | ||
528 | out_free_conf: | |
529 | if (conf->pool) | |
530 | mempool_destroy(conf->pool); | |
990a8baf | 531 | kfree(conf->multipaths); |
1da177e4 LT |
532 | kfree(conf); |
533 | mddev->private = NULL; | |
534 | out: | |
535 | return -EIO; | |
536 | } | |
537 | ||
538 | ||
539 | static int multipath_stop (mddev_t *mddev) | |
540 | { | |
541 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
542 | ||
543 | md_unregister_thread(mddev->thread); | |
544 | mddev->thread = NULL; | |
545 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
546 | mempool_destroy(conf->pool); | |
547 | kfree(conf->multipaths); | |
548 | kfree(conf); | |
549 | mddev->private = NULL; | |
550 | return 0; | |
551 | } | |
552 | ||
2604b703 | 553 | static struct mdk_personality multipath_personality = |
1da177e4 LT |
554 | { |
555 | .name = "multipath", | |
2604b703 | 556 | .level = LEVEL_MULTIPATH, |
1da177e4 LT |
557 | .owner = THIS_MODULE, |
558 | .make_request = multipath_make_request, | |
559 | .run = multipath_run, | |
560 | .stop = multipath_stop, | |
561 | .status = multipath_status, | |
562 | .error_handler = multipath_error, | |
563 | .hot_add_disk = multipath_add_disk, | |
564 | .hot_remove_disk= multipath_remove_disk, | |
565 | }; | |
566 | ||
567 | static int __init multipath_init (void) | |
568 | { | |
2604b703 | 569 | return register_md_personality (&multipath_personality); |
1da177e4 LT |
570 | } |
571 | ||
572 | static void __exit multipath_exit (void) | |
573 | { | |
2604b703 | 574 | unregister_md_personality (&multipath_personality); |
1da177e4 LT |
575 | } |
576 | ||
577 | module_init(multipath_init); | |
578 | module_exit(multipath_exit); | |
579 | MODULE_LICENSE("GPL"); | |
580 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ | |
d9d166c2 | 581 | MODULE_ALIAS("md-multipath"); |
2604b703 | 582 | MODULE_ALIAS("md-level--4"); |