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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 | ||
2ad8b1ef | 128 | blk_unplug(r_queue); |
1da177e4 LT |
129 | |
130 | rdev_dec_pending(rdev, mddev); | |
131 | rcu_read_lock(); | |
132 | } | |
133 | } | |
134 | rcu_read_unlock(); | |
135 | } | |
136 | ||
165125e1 | 137 | static void multipath_unplug(struct request_queue *q) |
1da177e4 LT |
138 | { |
139 | unplug_slaves(q->queuedata); | |
140 | } | |
141 | ||
142 | ||
165125e1 | 143 | static int multipath_make_request (struct request_queue *q, struct bio * bio) |
1da177e4 LT |
144 | { |
145 | mddev_t *mddev = q->queuedata; | |
146 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
147 | struct multipath_bh * mp_bh; | |
148 | struct multipath_info *multipath; | |
a362357b | 149 | const int rw = bio_data_dir(bio); |
c9959059 | 150 | int cpu; |
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 | ||
074a7aca TH |
162 | cpu = part_stat_lock(); |
163 | part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); | |
164 | part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], | |
165 | bio_sectors(bio)); | |
166 | part_stat_unlock(); | |
1da177e4 LT |
167 | |
168 | mp_bh->path = multipath_map(conf); | |
169 | if (mp_bh->path < 0) { | |
6712ecf8 | 170 | bio_endio(bio, -EIO); |
1da177e4 LT |
171 | mempool_free(mp_bh, conf->pool); |
172 | return 0; | |
173 | } | |
174 | multipath = conf->multipaths + mp_bh->path; | |
175 | ||
176 | mp_bh->bio = *bio; | |
177 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; | |
178 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; | |
179 | mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST); | |
180 | mp_bh->bio.bi_end_io = multipath_end_request; | |
181 | mp_bh->bio.bi_private = mp_bh; | |
182 | generic_make_request(&mp_bh->bio); | |
183 | return 0; | |
184 | } | |
185 | ||
186 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) | |
187 | { | |
188 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
189 | int i; | |
190 | ||
191 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, | |
192 | conf->working_disks); | |
193 | for (i = 0; i < conf->raid_disks; i++) | |
194 | seq_printf (seq, "%s", | |
195 | conf->multipaths[i].rdev && | |
b2d444d7 | 196 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
197 | seq_printf (seq, "]"); |
198 | } | |
199 | ||
0d129228 N |
200 | static int multipath_congested(void *data, int bits) |
201 | { | |
202 | mddev_t *mddev = data; | |
203 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
204 | int i, ret = 0; | |
205 | ||
206 | rcu_read_lock(); | |
207 | for (i = 0; i < mddev->raid_disks ; i++) { | |
208 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); | |
209 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 210 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
211 | |
212 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
213 | /* Just like multipath_map, we just check the | |
214 | * first available device | |
215 | */ | |
216 | break; | |
217 | } | |
218 | } | |
219 | rcu_read_unlock(); | |
220 | return ret; | |
221 | } | |
1da177e4 LT |
222 | |
223 | /* | |
224 | * Careful, this can execute in IRQ contexts as well! | |
225 | */ | |
226 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) | |
227 | { | |
228 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
229 | ||
230 | if (conf->working_disks <= 1) { | |
231 | /* | |
232 | * Uh oh, we can do nothing if this is our last path, but | |
233 | * first check if this is a queued request for a device | |
234 | * which has just failed. | |
235 | */ | |
236 | printk(KERN_ALERT | |
237 | "multipath: only one IO path left and IO error.\n"); | |
238 | /* leave it active... it's all we have */ | |
239 | } else { | |
240 | /* | |
241 | * Mark disk as unusable | |
242 | */ | |
b2d444d7 | 243 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 244 | char b[BDEVNAME_SIZE]; |
b2d444d7 N |
245 | clear_bit(In_sync, &rdev->flags); |
246 | set_bit(Faulty, &rdev->flags); | |
850b2b42 | 247 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
1da177e4 | 248 | conf->working_disks--; |
750a8f3e | 249 | mddev->degraded++; |
1da177e4 | 250 | printk(KERN_ALERT "multipath: IO failure on %s," |
d7a420c9 NA |
251 | " disabling IO path.\n" |
252 | "multipath: Operation continuing" | |
1da177e4 LT |
253 | " on %d IO paths.\n", |
254 | bdevname (rdev->bdev,b), | |
255 | conf->working_disks); | |
256 | } | |
257 | } | |
258 | } | |
259 | ||
260 | static void print_multipath_conf (multipath_conf_t *conf) | |
261 | { | |
262 | int i; | |
263 | struct multipath_info *tmp; | |
264 | ||
265 | printk("MULTIPATH conf printout:\n"); | |
266 | if (!conf) { | |
267 | printk("(conf==NULL)\n"); | |
268 | return; | |
269 | } | |
270 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
271 | conf->raid_disks); | |
272 | ||
273 | for (i = 0; i < conf->raid_disks; i++) { | |
274 | char b[BDEVNAME_SIZE]; | |
275 | tmp = conf->multipaths + i; | |
276 | if (tmp->rdev) | |
277 | printk(" disk%d, o:%d, dev:%s\n", | |
b2d444d7 | 278 | i,!test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
279 | bdevname(tmp->rdev->bdev,b)); |
280 | } | |
281 | } | |
282 | ||
283 | ||
284 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
285 | { | |
286 | multipath_conf_t *conf = mddev->private; | |
352d768b | 287 | struct request_queue *q; |
199050ea | 288 | int err = -EEXIST; |
1da177e4 LT |
289 | int path; |
290 | struct multipath_info *p; | |
6c2fce2e NB |
291 | int first = 0; |
292 | int last = mddev->raid_disks - 1; | |
293 | ||
294 | if (rdev->raid_disk >= 0) | |
295 | first = last = rdev->raid_disk; | |
1da177e4 LT |
296 | |
297 | print_multipath_conf(conf); | |
298 | ||
6c2fce2e | 299 | for (path = first; path <= last; path++) |
1da177e4 | 300 | if ((p=conf->multipaths+path)->rdev == NULL) { |
352d768b JJ |
301 | q = rdev->bdev->bd_disk->queue; |
302 | blk_queue_stack_limits(mddev->queue, q); | |
1da177e4 LT |
303 | |
304 | /* as we don't honour merge_bvec_fn, we must never risk | |
305 | * violating it, so limit ->max_sector to one PAGE, as | |
306 | * a one page request is never in violation. | |
307 | * (Note: it is very unlikely that a device with | |
308 | * merge_bvec_fn will be involved in multipath.) | |
309 | */ | |
352d768b | 310 | if (q->merge_bvec_fn && |
1da177e4 LT |
311 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) |
312 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
313 | ||
314 | conf->working_disks++; | |
750a8f3e | 315 | mddev->degraded--; |
1da177e4 | 316 | rdev->raid_disk = path; |
b2d444d7 | 317 | set_bit(In_sync, &rdev->flags); |
d6065f7b | 318 | rcu_assign_pointer(p->rdev, rdev); |
199050ea NB |
319 | err = 0; |
320 | break; | |
1da177e4 LT |
321 | } |
322 | ||
323 | print_multipath_conf(conf); | |
199050ea NB |
324 | |
325 | return err; | |
1da177e4 LT |
326 | } |
327 | ||
328 | static int multipath_remove_disk(mddev_t *mddev, int number) | |
329 | { | |
330 | multipath_conf_t *conf = mddev->private; | |
331 | int err = 0; | |
332 | mdk_rdev_t *rdev; | |
333 | struct multipath_info *p = conf->multipaths + number; | |
334 | ||
335 | print_multipath_conf(conf); | |
336 | ||
337 | rdev = p->rdev; | |
338 | if (rdev) { | |
b2d444d7 | 339 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 | 340 | atomic_read(&rdev->nr_pending)) { |
dfc70645 N |
341 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" |
342 | " but is still operational!\n", number); | |
1da177e4 LT |
343 | err = -EBUSY; |
344 | goto abort; | |
345 | } | |
346 | p->rdev = NULL; | |
fbd568a3 | 347 | synchronize_rcu(); |
1da177e4 LT |
348 | if (atomic_read(&rdev->nr_pending)) { |
349 | /* lost the race, try later */ | |
350 | err = -EBUSY; | |
351 | p->rdev = rdev; | |
352 | } | |
353 | } | |
354 | abort: | |
355 | ||
356 | print_multipath_conf(conf); | |
357 | return err; | |
358 | } | |
359 | ||
360 | ||
361 | ||
362 | /* | |
363 | * This is a kernel thread which: | |
364 | * | |
365 | * 1. Retries failed read operations on working multipaths. | |
366 | * 2. Updates the raid superblock when problems encounter. | |
367 | * 3. Performs writes following reads for array syncronising. | |
368 | */ | |
369 | ||
370 | static void multipathd (mddev_t *mddev) | |
371 | { | |
372 | struct multipath_bh *mp_bh; | |
373 | struct bio *bio; | |
374 | unsigned long flags; | |
375 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
376 | struct list_head *head = &conf->retry_list; | |
377 | ||
378 | md_check_recovery(mddev); | |
379 | for (;;) { | |
380 | char b[BDEVNAME_SIZE]; | |
381 | spin_lock_irqsave(&conf->device_lock, flags); | |
382 | if (list_empty(head)) | |
383 | break; | |
384 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); | |
385 | list_del(head->prev); | |
386 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
387 | ||
388 | bio = &mp_bh->bio; | |
389 | bio->bi_sector = mp_bh->master_bio->bi_sector; | |
390 | ||
391 | if ((mp_bh->path = multipath_map (conf))<0) { | |
392 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" | |
393 | " error for block %llu\n", | |
394 | bdevname(bio->bi_bdev,b), | |
395 | (unsigned long long)bio->bi_sector); | |
396 | multipath_end_bh_io(mp_bh, -EIO); | |
397 | } else { | |
398 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" | |
399 | " to another IO path\n", | |
400 | bdevname(bio->bi_bdev,b), | |
401 | (unsigned long long)bio->bi_sector); | |
402 | *bio = *(mp_bh->master_bio); | |
403 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; | |
404 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; | |
405 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); | |
406 | bio->bi_end_io = multipath_end_request; | |
407 | bio->bi_private = mp_bh; | |
408 | generic_make_request(bio); | |
409 | } | |
410 | } | |
411 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
412 | } | |
413 | ||
414 | static int multipath_run (mddev_t *mddev) | |
415 | { | |
416 | multipath_conf_t *conf; | |
417 | int disk_idx; | |
418 | struct multipath_info *disk; | |
419 | mdk_rdev_t *rdev; | |
420 | struct list_head *tmp; | |
421 | ||
422 | if (mddev->level != LEVEL_MULTIPATH) { | |
423 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", | |
424 | mdname(mddev), mddev->level); | |
425 | goto out; | |
426 | } | |
427 | /* | |
428 | * copy the already verified devices into our private MULTIPATH | |
429 | * bookkeeping area. [whatever we allocate in multipath_run(), | |
430 | * should be freed in multipath_stop()] | |
431 | */ | |
e7e72bf6 | 432 | mddev->queue->queue_lock = &mddev->queue->__queue_lock; |
1da177e4 | 433 | |
9ffae0cf | 434 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
1da177e4 LT |
435 | mddev->private = conf; |
436 | if (!conf) { | |
437 | printk(KERN_ERR | |
438 | "multipath: couldn't allocate memory for %s\n", | |
439 | mdname(mddev)); | |
440 | goto out; | |
441 | } | |
1da177e4 | 442 | |
9ffae0cf | 443 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
1da177e4 LT |
444 | GFP_KERNEL); |
445 | if (!conf->multipaths) { | |
446 | printk(KERN_ERR | |
447 | "multipath: couldn't allocate memory for %s\n", | |
448 | mdname(mddev)); | |
449 | goto out_free_conf; | |
450 | } | |
1da177e4 | 451 | |
1da177e4 | 452 | conf->working_disks = 0; |
d089c6af | 453 | rdev_for_each(rdev, tmp, mddev) { |
1da177e4 LT |
454 | disk_idx = rdev->raid_disk; |
455 | if (disk_idx < 0 || | |
456 | disk_idx >= mddev->raid_disks) | |
457 | continue; | |
458 | ||
459 | disk = conf->multipaths + disk_idx; | |
460 | disk->rdev = rdev; | |
461 | ||
462 | blk_queue_stack_limits(mddev->queue, | |
463 | rdev->bdev->bd_disk->queue); | |
464 | /* as we don't honour merge_bvec_fn, we must never risk | |
465 | * violating it, not that we ever expect a device with | |
466 | * a merge_bvec_fn to be involved in multipath */ | |
467 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && | |
468 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) | |
469 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); | |
470 | ||
b2d444d7 | 471 | if (!test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
472 | conf->working_disks++; |
473 | } | |
474 | ||
475 | conf->raid_disks = mddev->raid_disks; | |
1da177e4 LT |
476 | conf->mddev = mddev; |
477 | spin_lock_init(&conf->device_lock); | |
478 | INIT_LIST_HEAD(&conf->retry_list); | |
479 | ||
480 | if (!conf->working_disks) { | |
481 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", | |
482 | mdname(mddev)); | |
483 | goto out_free_conf; | |
484 | } | |
2e333e89 | 485 | mddev->degraded = conf->raid_disks - conf->working_disks; |
1da177e4 | 486 | |
26b6e051 MD |
487 | conf->pool = mempool_create_kzalloc_pool(NR_RESERVED_BUFS, |
488 | sizeof(struct multipath_bh)); | |
1da177e4 LT |
489 | if (conf->pool == NULL) { |
490 | printk(KERN_ERR | |
491 | "multipath: couldn't allocate memory for %s\n", | |
492 | mdname(mddev)); | |
493 | goto out_free_conf; | |
494 | } | |
495 | ||
496 | { | |
497 | mddev->thread = md_register_thread(multipathd, mddev, "%s_multipath"); | |
498 | if (!mddev->thread) { | |
499 | printk(KERN_ERR "multipath: couldn't allocate thread" | |
500 | " for %s\n", mdname(mddev)); | |
501 | goto out_free_conf; | |
502 | } | |
503 | } | |
504 | ||
505 | printk(KERN_INFO | |
506 | "multipath: array %s active with %d out of %d IO paths\n", | |
507 | mdname(mddev), conf->working_disks, mddev->raid_disks); | |
508 | /* | |
509 | * Ok, everything is just fine now | |
510 | */ | |
f233ea5c | 511 | mddev->array_sectors = mddev->size * 2; |
7a5febe9 N |
512 | |
513 | mddev->queue->unplug_fn = multipath_unplug; | |
0d129228 N |
514 | mddev->queue->backing_dev_info.congested_fn = multipath_congested; |
515 | mddev->queue->backing_dev_info.congested_data = mddev; | |
7a5febe9 | 516 | |
1da177e4 LT |
517 | return 0; |
518 | ||
519 | out_free_conf: | |
520 | if (conf->pool) | |
521 | mempool_destroy(conf->pool); | |
990a8baf | 522 | kfree(conf->multipaths); |
1da177e4 LT |
523 | kfree(conf); |
524 | mddev->private = NULL; | |
525 | out: | |
526 | return -EIO; | |
527 | } | |
528 | ||
529 | ||
530 | static int multipath_stop (mddev_t *mddev) | |
531 | { | |
532 | multipath_conf_t *conf = mddev_to_conf(mddev); | |
533 | ||
534 | md_unregister_thread(mddev->thread); | |
535 | mddev->thread = NULL; | |
536 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
537 | mempool_destroy(conf->pool); | |
538 | kfree(conf->multipaths); | |
539 | kfree(conf); | |
540 | mddev->private = NULL; | |
541 | return 0; | |
542 | } | |
543 | ||
2604b703 | 544 | static struct mdk_personality multipath_personality = |
1da177e4 LT |
545 | { |
546 | .name = "multipath", | |
2604b703 | 547 | .level = LEVEL_MULTIPATH, |
1da177e4 LT |
548 | .owner = THIS_MODULE, |
549 | .make_request = multipath_make_request, | |
550 | .run = multipath_run, | |
551 | .stop = multipath_stop, | |
552 | .status = multipath_status, | |
553 | .error_handler = multipath_error, | |
554 | .hot_add_disk = multipath_add_disk, | |
555 | .hot_remove_disk= multipath_remove_disk, | |
556 | }; | |
557 | ||
558 | static int __init multipath_init (void) | |
559 | { | |
2604b703 | 560 | return register_md_personality (&multipath_personality); |
1da177e4 LT |
561 | } |
562 | ||
563 | static void __exit multipath_exit (void) | |
564 | { | |
2604b703 | 565 | unregister_md_personality (&multipath_personality); |
1da177e4 LT |
566 | } |
567 | ||
568 | module_init(multipath_init); | |
569 | module_exit(multipath_exit); | |
570 | MODULE_LICENSE("GPL"); | |
571 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ | |
d9d166c2 | 572 | MODULE_ALIAS("md-multipath"); |
2604b703 | 573 | MODULE_ALIAS("md-level--4"); |