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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 | ||
bff61975 N |
22 | #include <linux/blkdev.h> |
23 | #include <linux/raid/md_u.h> | |
bff61975 | 24 | #include <linux/seq_file.h> |
5a0e3ad6 | 25 | #include <linux/slab.h> |
43b2e5d8 | 26 | #include "md.h" |
ef740c37 | 27 | #include "multipath.h" |
1da177e4 LT |
28 | |
29 | #define MAX_WORK_PER_DISK 128 | |
30 | ||
31 | #define NR_RESERVED_BUFS 32 | |
32 | ||
33 | ||
1da177e4 LT |
34 | static int multipath_map (multipath_conf_t *conf) |
35 | { | |
36 | int i, disks = conf->raid_disks; | |
37 | ||
38 | /* | |
39 | * Later we do read balancing on the read side | |
40 | * now we use the first available disk. | |
41 | */ | |
42 | ||
43 | rcu_read_lock(); | |
44 | for (i = 0; i < disks; i++) { | |
d6065f7b | 45 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 | 46 | if (rdev && test_bit(In_sync, &rdev->flags)) { |
1da177e4 LT |
47 | atomic_inc(&rdev->nr_pending); |
48 | rcu_read_unlock(); | |
49 | return i; | |
50 | } | |
51 | } | |
52 | rcu_read_unlock(); | |
53 | ||
54 | printk(KERN_ERR "multipath_map(): no more operational IO paths?\n"); | |
55 | return (-1); | |
56 | } | |
57 | ||
58 | static void multipath_reschedule_retry (struct multipath_bh *mp_bh) | |
59 | { | |
60 | unsigned long flags; | |
61 | mddev_t *mddev = mp_bh->mddev; | |
070ec55d | 62 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
63 | |
64 | spin_lock_irqsave(&conf->device_lock, flags); | |
65 | list_add(&mp_bh->retry_list, &conf->retry_list); | |
66 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
67 | md_wakeup_thread(mddev->thread); | |
68 | } | |
69 | ||
70 | ||
71 | /* | |
72 | * multipath_end_bh_io() is called when we have finished servicing a multipathed | |
73 | * operation and are ready to return a success/failure code to the buffer | |
74 | * cache layer. | |
75 | */ | |
76 | static void multipath_end_bh_io (struct multipath_bh *mp_bh, int err) | |
77 | { | |
78 | struct bio *bio = mp_bh->master_bio; | |
070ec55d | 79 | multipath_conf_t *conf = mp_bh->mddev->private; |
1da177e4 | 80 | |
6712ecf8 | 81 | bio_endio(bio, err); |
1da177e4 LT |
82 | mempool_free(mp_bh, conf->pool); |
83 | } | |
84 | ||
6712ecf8 | 85 | static void multipath_end_request(struct bio *bio, int error) |
1da177e4 LT |
86 | { |
87 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
7b92813c | 88 | struct multipath_bh *mp_bh = bio->bi_private; |
070ec55d | 89 | multipath_conf_t *conf = mp_bh->mddev->private; |
1da177e4 LT |
90 | mdk_rdev_t *rdev = conf->multipaths[mp_bh->path].rdev; |
91 | ||
1da177e4 LT |
92 | if (uptodate) |
93 | multipath_end_bh_io(mp_bh, 0); | |
7b6d91da | 94 | else if (!(bio->bi_rw & REQ_RAHEAD)) { |
1da177e4 LT |
95 | /* |
96 | * oops, IO error: | |
97 | */ | |
98 | char b[BDEVNAME_SIZE]; | |
99 | md_error (mp_bh->mddev, rdev); | |
100 | printk(KERN_ERR "multipath: %s: rescheduling sector %llu\n", | |
101 | bdevname(rdev->bdev,b), | |
102 | (unsigned long long)bio->bi_sector); | |
103 | multipath_reschedule_retry(mp_bh); | |
104 | } else | |
105 | multipath_end_bh_io(mp_bh, error); | |
106 | rdev_dec_pending(rdev, conf->mddev); | |
1da177e4 LT |
107 | } |
108 | ||
21a52c6d | 109 | static int multipath_make_request(mddev_t *mddev, struct bio * bio) |
1da177e4 | 110 | { |
070ec55d | 111 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
112 | struct multipath_bh * mp_bh; |
113 | struct multipath_info *multipath; | |
114 | ||
e9c7469b TH |
115 | if (unlikely(bio->bi_rw & REQ_FLUSH)) { |
116 | md_flush_request(mddev, bio); | |
e5dcdd80 N |
117 | return 0; |
118 | } | |
119 | ||
1da177e4 LT |
120 | mp_bh = mempool_alloc(conf->pool, GFP_NOIO); |
121 | ||
122 | mp_bh->master_bio = bio; | |
123 | mp_bh->mddev = mddev; | |
124 | ||
1da177e4 LT |
125 | mp_bh->path = multipath_map(conf); |
126 | if (mp_bh->path < 0) { | |
6712ecf8 | 127 | bio_endio(bio, -EIO); |
1da177e4 LT |
128 | mempool_free(mp_bh, conf->pool); |
129 | return 0; | |
130 | } | |
131 | multipath = conf->multipaths + mp_bh->path; | |
132 | ||
133 | mp_bh->bio = *bio; | |
134 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; | |
135 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; | |
7b6d91da | 136 | mp_bh->bio.bi_rw |= REQ_FAILFAST_TRANSPORT; |
1da177e4 LT |
137 | mp_bh->bio.bi_end_io = multipath_end_request; |
138 | mp_bh->bio.bi_private = mp_bh; | |
139 | generic_make_request(&mp_bh->bio); | |
140 | return 0; | |
141 | } | |
142 | ||
143 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) | |
144 | { | |
070ec55d | 145 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
146 | int i; |
147 | ||
148 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, | |
149 | conf->working_disks); | |
150 | for (i = 0; i < conf->raid_disks; i++) | |
151 | seq_printf (seq, "%s", | |
152 | conf->multipaths[i].rdev && | |
b2d444d7 | 153 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
154 | seq_printf (seq, "]"); |
155 | } | |
156 | ||
0d129228 N |
157 | static int multipath_congested(void *data, int bits) |
158 | { | |
159 | mddev_t *mddev = data; | |
070ec55d | 160 | multipath_conf_t *conf = mddev->private; |
0d129228 N |
161 | int i, ret = 0; |
162 | ||
3fa841d7 N |
163 | if (mddev_congested(mddev, bits)) |
164 | return 1; | |
165 | ||
0d129228 N |
166 | rcu_read_lock(); |
167 | for (i = 0; i < mddev->raid_disks ; i++) { | |
168 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); | |
169 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 170 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
171 | |
172 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
173 | /* Just like multipath_map, we just check the | |
174 | * first available device | |
175 | */ | |
176 | break; | |
177 | } | |
178 | } | |
179 | rcu_read_unlock(); | |
180 | return ret; | |
181 | } | |
1da177e4 LT |
182 | |
183 | /* | |
184 | * Careful, this can execute in IRQ contexts as well! | |
185 | */ | |
186 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) | |
187 | { | |
070ec55d | 188 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
189 | |
190 | if (conf->working_disks <= 1) { | |
191 | /* | |
192 | * Uh oh, we can do nothing if this is our last path, but | |
193 | * first check if this is a queued request for a device | |
194 | * which has just failed. | |
195 | */ | |
196 | printk(KERN_ALERT | |
197 | "multipath: only one IO path left and IO error.\n"); | |
198 | /* leave it active... it's all we have */ | |
199 | } else { | |
200 | /* | |
201 | * Mark disk as unusable | |
202 | */ | |
b2d444d7 | 203 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 204 | char b[BDEVNAME_SIZE]; |
b2d444d7 N |
205 | clear_bit(In_sync, &rdev->flags); |
206 | set_bit(Faulty, &rdev->flags); | |
850b2b42 | 207 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
1da177e4 | 208 | conf->working_disks--; |
750a8f3e | 209 | mddev->degraded++; |
1da177e4 | 210 | printk(KERN_ALERT "multipath: IO failure on %s," |
d7a420c9 NA |
211 | " disabling IO path.\n" |
212 | "multipath: Operation continuing" | |
1da177e4 LT |
213 | " on %d IO paths.\n", |
214 | bdevname (rdev->bdev,b), | |
215 | conf->working_disks); | |
216 | } | |
217 | } | |
218 | } | |
219 | ||
220 | static void print_multipath_conf (multipath_conf_t *conf) | |
221 | { | |
222 | int i; | |
223 | struct multipath_info *tmp; | |
224 | ||
225 | printk("MULTIPATH conf printout:\n"); | |
226 | if (!conf) { | |
227 | printk("(conf==NULL)\n"); | |
228 | return; | |
229 | } | |
230 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
231 | conf->raid_disks); | |
232 | ||
233 | for (i = 0; i < conf->raid_disks; i++) { | |
234 | char b[BDEVNAME_SIZE]; | |
235 | tmp = conf->multipaths + i; | |
236 | if (tmp->rdev) | |
237 | printk(" disk%d, o:%d, dev:%s\n", | |
b2d444d7 | 238 | i,!test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
239 | bdevname(tmp->rdev->bdev,b)); |
240 | } | |
241 | } | |
242 | ||
243 | ||
244 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
245 | { | |
246 | multipath_conf_t *conf = mddev->private; | |
352d768b | 247 | struct request_queue *q; |
199050ea | 248 | int err = -EEXIST; |
1da177e4 LT |
249 | int path; |
250 | struct multipath_info *p; | |
6c2fce2e NB |
251 | int first = 0; |
252 | int last = mddev->raid_disks - 1; | |
253 | ||
254 | if (rdev->raid_disk >= 0) | |
255 | first = last = rdev->raid_disk; | |
1da177e4 LT |
256 | |
257 | print_multipath_conf(conf); | |
258 | ||
6c2fce2e | 259 | for (path = first; path <= last; path++) |
1da177e4 | 260 | if ((p=conf->multipaths+path)->rdev == NULL) { |
352d768b | 261 | q = rdev->bdev->bd_disk->queue; |
8f6c2e4b MP |
262 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
263 | rdev->data_offset << 9); | |
1da177e4 LT |
264 | |
265 | /* as we don't honour merge_bvec_fn, we must never risk | |
627a2d3c N |
266 | * violating it, so limit ->max_segments to one, lying |
267 | * within a single page. | |
1da177e4 LT |
268 | * (Note: it is very unlikely that a device with |
269 | * merge_bvec_fn will be involved in multipath.) | |
270 | */ | |
627a2d3c N |
271 | if (q->merge_bvec_fn) { |
272 | blk_queue_max_segments(mddev->queue, 1); | |
273 | blk_queue_segment_boundary(mddev->queue, | |
274 | PAGE_CACHE_SIZE - 1); | |
275 | } | |
1da177e4 LT |
276 | |
277 | conf->working_disks++; | |
750a8f3e | 278 | mddev->degraded--; |
1da177e4 | 279 | rdev->raid_disk = path; |
b2d444d7 | 280 | set_bit(In_sync, &rdev->flags); |
d6065f7b | 281 | rcu_assign_pointer(p->rdev, rdev); |
199050ea | 282 | err = 0; |
ac5e7113 | 283 | md_integrity_add_rdev(rdev, mddev); |
199050ea | 284 | break; |
1da177e4 LT |
285 | } |
286 | ||
287 | print_multipath_conf(conf); | |
199050ea NB |
288 | |
289 | return err; | |
1da177e4 LT |
290 | } |
291 | ||
292 | static int multipath_remove_disk(mddev_t *mddev, int number) | |
293 | { | |
294 | multipath_conf_t *conf = mddev->private; | |
295 | int err = 0; | |
296 | mdk_rdev_t *rdev; | |
297 | struct multipath_info *p = conf->multipaths + number; | |
298 | ||
299 | print_multipath_conf(conf); | |
300 | ||
301 | rdev = p->rdev; | |
302 | if (rdev) { | |
b2d444d7 | 303 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 | 304 | atomic_read(&rdev->nr_pending)) { |
dfc70645 N |
305 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" |
306 | " but is still operational!\n", number); | |
1da177e4 LT |
307 | err = -EBUSY; |
308 | goto abort; | |
309 | } | |
310 | p->rdev = NULL; | |
fbd568a3 | 311 | synchronize_rcu(); |
1da177e4 LT |
312 | if (atomic_read(&rdev->nr_pending)) { |
313 | /* lost the race, try later */ | |
314 | err = -EBUSY; | |
315 | p->rdev = rdev; | |
ac5e7113 | 316 | goto abort; |
1da177e4 | 317 | } |
a91a2785 | 318 | err = md_integrity_register(mddev); |
1da177e4 LT |
319 | } |
320 | abort: | |
321 | ||
322 | print_multipath_conf(conf); | |
323 | return err; | |
324 | } | |
325 | ||
326 | ||
327 | ||
328 | /* | |
329 | * This is a kernel thread which: | |
330 | * | |
331 | * 1. Retries failed read operations on working multipaths. | |
332 | * 2. Updates the raid superblock when problems encounter. | |
333 | * 3. Performs writes following reads for array syncronising. | |
334 | */ | |
335 | ||
336 | static void multipathd (mddev_t *mddev) | |
337 | { | |
338 | struct multipath_bh *mp_bh; | |
339 | struct bio *bio; | |
340 | unsigned long flags; | |
070ec55d | 341 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
342 | struct list_head *head = &conf->retry_list; |
343 | ||
344 | md_check_recovery(mddev); | |
345 | for (;;) { | |
346 | char b[BDEVNAME_SIZE]; | |
347 | spin_lock_irqsave(&conf->device_lock, flags); | |
348 | if (list_empty(head)) | |
349 | break; | |
350 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); | |
351 | list_del(head->prev); | |
352 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
353 | ||
354 | bio = &mp_bh->bio; | |
355 | bio->bi_sector = mp_bh->master_bio->bi_sector; | |
356 | ||
357 | if ((mp_bh->path = multipath_map (conf))<0) { | |
358 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" | |
359 | " error for block %llu\n", | |
360 | bdevname(bio->bi_bdev,b), | |
361 | (unsigned long long)bio->bi_sector); | |
362 | multipath_end_bh_io(mp_bh, -EIO); | |
363 | } else { | |
364 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" | |
365 | " to another IO path\n", | |
366 | bdevname(bio->bi_bdev,b), | |
367 | (unsigned long long)bio->bi_sector); | |
368 | *bio = *(mp_bh->master_bio); | |
369 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; | |
370 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; | |
7b6d91da | 371 | bio->bi_rw |= REQ_FAILFAST_TRANSPORT; |
1da177e4 LT |
372 | bio->bi_end_io = multipath_end_request; |
373 | bio->bi_private = mp_bh; | |
374 | generic_make_request(bio); | |
375 | } | |
376 | } | |
377 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
378 | } | |
379 | ||
80c3a6ce DW |
380 | static sector_t multipath_size(mddev_t *mddev, sector_t sectors, int raid_disks) |
381 | { | |
382 | WARN_ONCE(sectors || raid_disks, | |
383 | "%s does not support generic reshape\n", __func__); | |
384 | ||
385 | return mddev->dev_sectors; | |
386 | } | |
387 | ||
1da177e4 LT |
388 | static int multipath_run (mddev_t *mddev) |
389 | { | |
390 | multipath_conf_t *conf; | |
391 | int disk_idx; | |
392 | struct multipath_info *disk; | |
393 | mdk_rdev_t *rdev; | |
1da177e4 | 394 | |
0894cc30 AN |
395 | if (md_check_no_bitmap(mddev)) |
396 | return -EINVAL; | |
397 | ||
1da177e4 LT |
398 | if (mddev->level != LEVEL_MULTIPATH) { |
399 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", | |
400 | mdname(mddev), mddev->level); | |
401 | goto out; | |
402 | } | |
403 | /* | |
404 | * copy the already verified devices into our private MULTIPATH | |
405 | * bookkeeping area. [whatever we allocate in multipath_run(), | |
406 | * should be freed in multipath_stop()] | |
407 | */ | |
408 | ||
9ffae0cf | 409 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
1da177e4 LT |
410 | mddev->private = conf; |
411 | if (!conf) { | |
412 | printk(KERN_ERR | |
413 | "multipath: couldn't allocate memory for %s\n", | |
414 | mdname(mddev)); | |
415 | goto out; | |
416 | } | |
1da177e4 | 417 | |
9ffae0cf | 418 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
1da177e4 LT |
419 | GFP_KERNEL); |
420 | if (!conf->multipaths) { | |
421 | printk(KERN_ERR | |
422 | "multipath: couldn't allocate memory for %s\n", | |
423 | mdname(mddev)); | |
424 | goto out_free_conf; | |
425 | } | |
1da177e4 | 426 | |
1da177e4 | 427 | conf->working_disks = 0; |
159ec1fc | 428 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
1da177e4 LT |
429 | disk_idx = rdev->raid_disk; |
430 | if (disk_idx < 0 || | |
431 | disk_idx >= mddev->raid_disks) | |
432 | continue; | |
433 | ||
434 | disk = conf->multipaths + disk_idx; | |
435 | disk->rdev = rdev; | |
8f6c2e4b MP |
436 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
437 | rdev->data_offset << 9); | |
1da177e4 | 438 | |
1da177e4 LT |
439 | /* as we don't honour merge_bvec_fn, we must never risk |
440 | * violating it, not that we ever expect a device with | |
441 | * a merge_bvec_fn to be involved in multipath */ | |
627a2d3c N |
442 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { |
443 | blk_queue_max_segments(mddev->queue, 1); | |
444 | blk_queue_segment_boundary(mddev->queue, | |
445 | PAGE_CACHE_SIZE - 1); | |
446 | } | |
1da177e4 | 447 | |
b2d444d7 | 448 | if (!test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
449 | conf->working_disks++; |
450 | } | |
451 | ||
452 | conf->raid_disks = mddev->raid_disks; | |
1da177e4 LT |
453 | conf->mddev = mddev; |
454 | spin_lock_init(&conf->device_lock); | |
455 | INIT_LIST_HEAD(&conf->retry_list); | |
456 | ||
457 | if (!conf->working_disks) { | |
458 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", | |
459 | mdname(mddev)); | |
460 | goto out_free_conf; | |
461 | } | |
2e333e89 | 462 | mddev->degraded = conf->raid_disks - conf->working_disks; |
1da177e4 | 463 | |
bbba809e | 464 | conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS, |
26b6e051 | 465 | sizeof(struct multipath_bh)); |
1da177e4 LT |
466 | if (conf->pool == NULL) { |
467 | printk(KERN_ERR | |
468 | "multipath: couldn't allocate memory for %s\n", | |
469 | mdname(mddev)); | |
470 | goto out_free_conf; | |
471 | } | |
472 | ||
473 | { | |
0da3c619 | 474 | mddev->thread = md_register_thread(multipathd, mddev, NULL); |
1da177e4 LT |
475 | if (!mddev->thread) { |
476 | printk(KERN_ERR "multipath: couldn't allocate thread" | |
477 | " for %s\n", mdname(mddev)); | |
478 | goto out_free_conf; | |
479 | } | |
480 | } | |
481 | ||
482 | printk(KERN_INFO | |
483 | "multipath: array %s active with %d out of %d IO paths\n", | |
484 | mdname(mddev), conf->working_disks, mddev->raid_disks); | |
485 | /* | |
486 | * Ok, everything is just fine now | |
487 | */ | |
1f403624 | 488 | md_set_array_sectors(mddev, multipath_size(mddev, 0, 0)); |
7a5febe9 | 489 | |
0d129228 N |
490 | mddev->queue->backing_dev_info.congested_fn = multipath_congested; |
491 | mddev->queue->backing_dev_info.congested_data = mddev; | |
a91a2785 MP |
492 | |
493 | if (md_integrity_register(mddev)) | |
494 | goto out_free_conf; | |
495 | ||
1da177e4 LT |
496 | return 0; |
497 | ||
498 | out_free_conf: | |
499 | if (conf->pool) | |
500 | mempool_destroy(conf->pool); | |
990a8baf | 501 | kfree(conf->multipaths); |
1da177e4 LT |
502 | kfree(conf); |
503 | mddev->private = NULL; | |
504 | out: | |
505 | return -EIO; | |
506 | } | |
507 | ||
508 | ||
509 | static int multipath_stop (mddev_t *mddev) | |
510 | { | |
070ec55d | 511 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
512 | |
513 | md_unregister_thread(mddev->thread); | |
514 | mddev->thread = NULL; | |
515 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
516 | mempool_destroy(conf->pool); | |
517 | kfree(conf->multipaths); | |
518 | kfree(conf); | |
519 | mddev->private = NULL; | |
520 | return 0; | |
521 | } | |
522 | ||
2604b703 | 523 | static struct mdk_personality multipath_personality = |
1da177e4 LT |
524 | { |
525 | .name = "multipath", | |
2604b703 | 526 | .level = LEVEL_MULTIPATH, |
1da177e4 LT |
527 | .owner = THIS_MODULE, |
528 | .make_request = multipath_make_request, | |
529 | .run = multipath_run, | |
530 | .stop = multipath_stop, | |
531 | .status = multipath_status, | |
532 | .error_handler = multipath_error, | |
533 | .hot_add_disk = multipath_add_disk, | |
534 | .hot_remove_disk= multipath_remove_disk, | |
80c3a6ce | 535 | .size = multipath_size, |
1da177e4 LT |
536 | }; |
537 | ||
538 | static int __init multipath_init (void) | |
539 | { | |
2604b703 | 540 | return register_md_personality (&multipath_personality); |
1da177e4 LT |
541 | } |
542 | ||
543 | static void __exit multipath_exit (void) | |
544 | { | |
2604b703 | 545 | unregister_md_personality (&multipath_personality); |
1da177e4 LT |
546 | } |
547 | ||
548 | module_init(multipath_init); | |
549 | module_exit(multipath_exit); | |
550 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 551 | MODULE_DESCRIPTION("simple multi-path personality for MD"); |
1da177e4 | 552 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ |
d9d166c2 | 553 | MODULE_ALIAS("md-multipath"); |
2604b703 | 554 | MODULE_ALIAS("md-level--4"); |