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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); | |
88 | struct multipath_bh * mp_bh = (struct multipath_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); | |
1f98a13f | 94 | else if (!bio_rw_flagged(bio, BIO_RW_AHEAD)) { |
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 | ||
109 | static void unplug_slaves(mddev_t *mddev) | |
110 | { | |
070ec55d | 111 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
112 | int i; |
113 | ||
114 | rcu_read_lock(); | |
115 | for (i=0; i<mddev->raid_disks; i++) { | |
d6065f7b | 116 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
b2d444d7 N |
117 | if (rdev && !test_bit(Faulty, &rdev->flags) |
118 | && atomic_read(&rdev->nr_pending)) { | |
165125e1 | 119 | struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
1da177e4 LT |
120 | |
121 | atomic_inc(&rdev->nr_pending); | |
122 | rcu_read_unlock(); | |
123 | ||
2ad8b1ef | 124 | blk_unplug(r_queue); |
1da177e4 LT |
125 | |
126 | rdev_dec_pending(rdev, mddev); | |
127 | rcu_read_lock(); | |
128 | } | |
129 | } | |
130 | rcu_read_unlock(); | |
131 | } | |
132 | ||
165125e1 | 133 | static void multipath_unplug(struct request_queue *q) |
1da177e4 LT |
134 | { |
135 | unplug_slaves(q->queuedata); | |
136 | } | |
137 | ||
138 | ||
165125e1 | 139 | static int multipath_make_request (struct request_queue *q, struct bio * bio) |
1da177e4 LT |
140 | { |
141 | mddev_t *mddev = q->queuedata; | |
070ec55d | 142 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
143 | struct multipath_bh * mp_bh; |
144 | struct multipath_info *multipath; | |
a362357b | 145 | const int rw = bio_data_dir(bio); |
c9959059 | 146 | int cpu; |
1da177e4 | 147 | |
1f98a13f | 148 | if (unlikely(bio_rw_flagged(bio, BIO_RW_BARRIER))) { |
a2826aa9 | 149 | md_barrier_request(mddev, bio); |
e5dcdd80 N |
150 | return 0; |
151 | } | |
152 | ||
1da177e4 LT |
153 | mp_bh = mempool_alloc(conf->pool, GFP_NOIO); |
154 | ||
155 | mp_bh->master_bio = bio; | |
156 | mp_bh->mddev = mddev; | |
157 | ||
074a7aca TH |
158 | cpu = part_stat_lock(); |
159 | part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); | |
160 | part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], | |
161 | bio_sectors(bio)); | |
162 | part_stat_unlock(); | |
1da177e4 LT |
163 | |
164 | mp_bh->path = multipath_map(conf); | |
165 | if (mp_bh->path < 0) { | |
6712ecf8 | 166 | bio_endio(bio, -EIO); |
1da177e4 LT |
167 | mempool_free(mp_bh, conf->pool); |
168 | return 0; | |
169 | } | |
170 | multipath = conf->multipaths + mp_bh->path; | |
171 | ||
172 | mp_bh->bio = *bio; | |
173 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; | |
174 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; | |
6000a368 | 175 | mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST_TRANSPORT); |
1da177e4 LT |
176 | mp_bh->bio.bi_end_io = multipath_end_request; |
177 | mp_bh->bio.bi_private = mp_bh; | |
178 | generic_make_request(&mp_bh->bio); | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) | |
183 | { | |
070ec55d | 184 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
185 | int i; |
186 | ||
187 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, | |
188 | conf->working_disks); | |
189 | for (i = 0; i < conf->raid_disks; i++) | |
190 | seq_printf (seq, "%s", | |
191 | conf->multipaths[i].rdev && | |
b2d444d7 | 192 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
1da177e4 LT |
193 | seq_printf (seq, "]"); |
194 | } | |
195 | ||
0d129228 N |
196 | static int multipath_congested(void *data, int bits) |
197 | { | |
198 | mddev_t *mddev = data; | |
070ec55d | 199 | multipath_conf_t *conf = mddev->private; |
0d129228 N |
200 | int i, ret = 0; |
201 | ||
3fa841d7 N |
202 | if (mddev_congested(mddev, bits)) |
203 | return 1; | |
204 | ||
0d129228 N |
205 | rcu_read_lock(); |
206 | for (i = 0; i < mddev->raid_disks ; i++) { | |
207 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); | |
208 | if (rdev && !test_bit(Faulty, &rdev->flags)) { | |
165125e1 | 209 | struct request_queue *q = bdev_get_queue(rdev->bdev); |
0d129228 N |
210 | |
211 | ret |= bdi_congested(&q->backing_dev_info, bits); | |
212 | /* Just like multipath_map, we just check the | |
213 | * first available device | |
214 | */ | |
215 | break; | |
216 | } | |
217 | } | |
218 | rcu_read_unlock(); | |
219 | return ret; | |
220 | } | |
1da177e4 LT |
221 | |
222 | /* | |
223 | * Careful, this can execute in IRQ contexts as well! | |
224 | */ | |
225 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) | |
226 | { | |
070ec55d | 227 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
228 | |
229 | if (conf->working_disks <= 1) { | |
230 | /* | |
231 | * Uh oh, we can do nothing if this is our last path, but | |
232 | * first check if this is a queued request for a device | |
233 | * which has just failed. | |
234 | */ | |
235 | printk(KERN_ALERT | |
236 | "multipath: only one IO path left and IO error.\n"); | |
237 | /* leave it active... it's all we have */ | |
238 | } else { | |
239 | /* | |
240 | * Mark disk as unusable | |
241 | */ | |
b2d444d7 | 242 | if (!test_bit(Faulty, &rdev->flags)) { |
1da177e4 | 243 | char b[BDEVNAME_SIZE]; |
b2d444d7 N |
244 | clear_bit(In_sync, &rdev->flags); |
245 | set_bit(Faulty, &rdev->flags); | |
850b2b42 | 246 | set_bit(MD_CHANGE_DEVS, &mddev->flags); |
1da177e4 | 247 | conf->working_disks--; |
750a8f3e | 248 | mddev->degraded++; |
1da177e4 | 249 | printk(KERN_ALERT "multipath: IO failure on %s," |
d7a420c9 NA |
250 | " disabling IO path.\n" |
251 | "multipath: Operation continuing" | |
1da177e4 LT |
252 | " on %d IO paths.\n", |
253 | bdevname (rdev->bdev,b), | |
254 | conf->working_disks); | |
255 | } | |
256 | } | |
257 | } | |
258 | ||
259 | static void print_multipath_conf (multipath_conf_t *conf) | |
260 | { | |
261 | int i; | |
262 | struct multipath_info *tmp; | |
263 | ||
264 | printk("MULTIPATH conf printout:\n"); | |
265 | if (!conf) { | |
266 | printk("(conf==NULL)\n"); | |
267 | return; | |
268 | } | |
269 | printk(" --- wd:%d rd:%d\n", conf->working_disks, | |
270 | conf->raid_disks); | |
271 | ||
272 | for (i = 0; i < conf->raid_disks; i++) { | |
273 | char b[BDEVNAME_SIZE]; | |
274 | tmp = conf->multipaths + i; | |
275 | if (tmp->rdev) | |
276 | printk(" disk%d, o:%d, dev:%s\n", | |
b2d444d7 | 277 | i,!test_bit(Faulty, &tmp->rdev->flags), |
1da177e4 LT |
278 | bdevname(tmp->rdev->bdev,b)); |
279 | } | |
280 | } | |
281 | ||
282 | ||
283 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) | |
284 | { | |
285 | multipath_conf_t *conf = mddev->private; | |
352d768b | 286 | struct request_queue *q; |
199050ea | 287 | int err = -EEXIST; |
1da177e4 LT |
288 | int path; |
289 | struct multipath_info *p; | |
6c2fce2e NB |
290 | int first = 0; |
291 | int last = mddev->raid_disks - 1; | |
292 | ||
293 | if (rdev->raid_disk >= 0) | |
294 | first = last = rdev->raid_disk; | |
1da177e4 LT |
295 | |
296 | print_multipath_conf(conf); | |
297 | ||
6c2fce2e | 298 | for (path = first; path <= last; path++) |
1da177e4 | 299 | if ((p=conf->multipaths+path)->rdev == NULL) { |
352d768b | 300 | q = rdev->bdev->bd_disk->queue; |
8f6c2e4b MP |
301 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
302 | rdev->data_offset << 9); | |
1da177e4 LT |
303 | |
304 | /* as we don't honour merge_bvec_fn, we must never risk | |
627a2d3c N |
305 | * violating it, so limit ->max_segments to one, lying |
306 | * within a single page. | |
1da177e4 LT |
307 | * (Note: it is very unlikely that a device with |
308 | * merge_bvec_fn will be involved in multipath.) | |
309 | */ | |
627a2d3c N |
310 | if (q->merge_bvec_fn) { |
311 | blk_queue_max_segments(mddev->queue, 1); | |
312 | blk_queue_segment_boundary(mddev->queue, | |
313 | PAGE_CACHE_SIZE - 1); | |
314 | } | |
1da177e4 LT |
315 | |
316 | conf->working_disks++; | |
750a8f3e | 317 | mddev->degraded--; |
1da177e4 | 318 | rdev->raid_disk = path; |
b2d444d7 | 319 | set_bit(In_sync, &rdev->flags); |
d6065f7b | 320 | rcu_assign_pointer(p->rdev, rdev); |
199050ea | 321 | err = 0; |
ac5e7113 | 322 | md_integrity_add_rdev(rdev, mddev); |
199050ea | 323 | break; |
1da177e4 LT |
324 | } |
325 | ||
326 | print_multipath_conf(conf); | |
199050ea NB |
327 | |
328 | return err; | |
1da177e4 LT |
329 | } |
330 | ||
331 | static int multipath_remove_disk(mddev_t *mddev, int number) | |
332 | { | |
333 | multipath_conf_t *conf = mddev->private; | |
334 | int err = 0; | |
335 | mdk_rdev_t *rdev; | |
336 | struct multipath_info *p = conf->multipaths + number; | |
337 | ||
338 | print_multipath_conf(conf); | |
339 | ||
340 | rdev = p->rdev; | |
341 | if (rdev) { | |
b2d444d7 | 342 | if (test_bit(In_sync, &rdev->flags) || |
1da177e4 | 343 | atomic_read(&rdev->nr_pending)) { |
dfc70645 N |
344 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" |
345 | " but is still operational!\n", number); | |
1da177e4 LT |
346 | err = -EBUSY; |
347 | goto abort; | |
348 | } | |
349 | p->rdev = NULL; | |
fbd568a3 | 350 | synchronize_rcu(); |
1da177e4 LT |
351 | if (atomic_read(&rdev->nr_pending)) { |
352 | /* lost the race, try later */ | |
353 | err = -EBUSY; | |
354 | p->rdev = rdev; | |
ac5e7113 | 355 | goto abort; |
1da177e4 | 356 | } |
ac5e7113 | 357 | md_integrity_register(mddev); |
1da177e4 LT |
358 | } |
359 | abort: | |
360 | ||
361 | print_multipath_conf(conf); | |
362 | return err; | |
363 | } | |
364 | ||
365 | ||
366 | ||
367 | /* | |
368 | * This is a kernel thread which: | |
369 | * | |
370 | * 1. Retries failed read operations on working multipaths. | |
371 | * 2. Updates the raid superblock when problems encounter. | |
372 | * 3. Performs writes following reads for array syncronising. | |
373 | */ | |
374 | ||
375 | static void multipathd (mddev_t *mddev) | |
376 | { | |
377 | struct multipath_bh *mp_bh; | |
378 | struct bio *bio; | |
379 | unsigned long flags; | |
070ec55d | 380 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
381 | struct list_head *head = &conf->retry_list; |
382 | ||
383 | md_check_recovery(mddev); | |
384 | for (;;) { | |
385 | char b[BDEVNAME_SIZE]; | |
386 | spin_lock_irqsave(&conf->device_lock, flags); | |
387 | if (list_empty(head)) | |
388 | break; | |
389 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); | |
390 | list_del(head->prev); | |
391 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
392 | ||
393 | bio = &mp_bh->bio; | |
394 | bio->bi_sector = mp_bh->master_bio->bi_sector; | |
395 | ||
396 | if ((mp_bh->path = multipath_map (conf))<0) { | |
397 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" | |
398 | " error for block %llu\n", | |
399 | bdevname(bio->bi_bdev,b), | |
400 | (unsigned long long)bio->bi_sector); | |
401 | multipath_end_bh_io(mp_bh, -EIO); | |
402 | } else { | |
403 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" | |
404 | " to another IO path\n", | |
405 | bdevname(bio->bi_bdev,b), | |
406 | (unsigned long long)bio->bi_sector); | |
407 | *bio = *(mp_bh->master_bio); | |
408 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; | |
409 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; | |
6000a368 | 410 | bio->bi_rw |= (1 << BIO_RW_FAILFAST_TRANSPORT); |
1da177e4 LT |
411 | bio->bi_end_io = multipath_end_request; |
412 | bio->bi_private = mp_bh; | |
413 | generic_make_request(bio); | |
414 | } | |
415 | } | |
416 | spin_unlock_irqrestore(&conf->device_lock, flags); | |
417 | } | |
418 | ||
80c3a6ce DW |
419 | static sector_t multipath_size(mddev_t *mddev, sector_t sectors, int raid_disks) |
420 | { | |
421 | WARN_ONCE(sectors || raid_disks, | |
422 | "%s does not support generic reshape\n", __func__); | |
423 | ||
424 | return mddev->dev_sectors; | |
425 | } | |
426 | ||
1da177e4 LT |
427 | static int multipath_run (mddev_t *mddev) |
428 | { | |
429 | multipath_conf_t *conf; | |
430 | int disk_idx; | |
431 | struct multipath_info *disk; | |
432 | mdk_rdev_t *rdev; | |
1da177e4 | 433 | |
0894cc30 AN |
434 | if (md_check_no_bitmap(mddev)) |
435 | return -EINVAL; | |
436 | ||
1da177e4 LT |
437 | if (mddev->level != LEVEL_MULTIPATH) { |
438 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", | |
439 | mdname(mddev), mddev->level); | |
440 | goto out; | |
441 | } | |
442 | /* | |
443 | * copy the already verified devices into our private MULTIPATH | |
444 | * bookkeeping area. [whatever we allocate in multipath_run(), | |
445 | * should be freed in multipath_stop()] | |
446 | */ | |
e7e72bf6 | 447 | mddev->queue->queue_lock = &mddev->queue->__queue_lock; |
1da177e4 | 448 | |
9ffae0cf | 449 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
1da177e4 LT |
450 | mddev->private = conf; |
451 | if (!conf) { | |
452 | printk(KERN_ERR | |
453 | "multipath: couldn't allocate memory for %s\n", | |
454 | mdname(mddev)); | |
455 | goto out; | |
456 | } | |
1da177e4 | 457 | |
9ffae0cf | 458 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
1da177e4 LT |
459 | GFP_KERNEL); |
460 | if (!conf->multipaths) { | |
461 | printk(KERN_ERR | |
462 | "multipath: couldn't allocate memory for %s\n", | |
463 | mdname(mddev)); | |
464 | goto out_free_conf; | |
465 | } | |
1da177e4 | 466 | |
1da177e4 | 467 | conf->working_disks = 0; |
159ec1fc | 468 | list_for_each_entry(rdev, &mddev->disks, same_set) { |
1da177e4 LT |
469 | disk_idx = rdev->raid_disk; |
470 | if (disk_idx < 0 || | |
471 | disk_idx >= mddev->raid_disks) | |
472 | continue; | |
473 | ||
474 | disk = conf->multipaths + disk_idx; | |
475 | disk->rdev = rdev; | |
8f6c2e4b MP |
476 | disk_stack_limits(mddev->gendisk, rdev->bdev, |
477 | rdev->data_offset << 9); | |
1da177e4 | 478 | |
1da177e4 LT |
479 | /* as we don't honour merge_bvec_fn, we must never risk |
480 | * violating it, not that we ever expect a device with | |
481 | * a merge_bvec_fn to be involved in multipath */ | |
627a2d3c N |
482 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { |
483 | blk_queue_max_segments(mddev->queue, 1); | |
484 | blk_queue_segment_boundary(mddev->queue, | |
485 | PAGE_CACHE_SIZE - 1); | |
486 | } | |
1da177e4 | 487 | |
b2d444d7 | 488 | if (!test_bit(Faulty, &rdev->flags)) |
1da177e4 LT |
489 | conf->working_disks++; |
490 | } | |
491 | ||
492 | conf->raid_disks = mddev->raid_disks; | |
1da177e4 LT |
493 | conf->mddev = mddev; |
494 | spin_lock_init(&conf->device_lock); | |
495 | INIT_LIST_HEAD(&conf->retry_list); | |
496 | ||
497 | if (!conf->working_disks) { | |
498 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", | |
499 | mdname(mddev)); | |
500 | goto out_free_conf; | |
501 | } | |
2e333e89 | 502 | mddev->degraded = conf->raid_disks - conf->working_disks; |
1da177e4 | 503 | |
bbba809e | 504 | conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS, |
26b6e051 | 505 | sizeof(struct multipath_bh)); |
1da177e4 LT |
506 | if (conf->pool == NULL) { |
507 | printk(KERN_ERR | |
508 | "multipath: couldn't allocate memory for %s\n", | |
509 | mdname(mddev)); | |
510 | goto out_free_conf; | |
511 | } | |
512 | ||
513 | { | |
0da3c619 | 514 | mddev->thread = md_register_thread(multipathd, mddev, NULL); |
1da177e4 LT |
515 | if (!mddev->thread) { |
516 | printk(KERN_ERR "multipath: couldn't allocate thread" | |
517 | " for %s\n", mdname(mddev)); | |
518 | goto out_free_conf; | |
519 | } | |
520 | } | |
521 | ||
522 | printk(KERN_INFO | |
523 | "multipath: array %s active with %d out of %d IO paths\n", | |
524 | mdname(mddev), conf->working_disks, mddev->raid_disks); | |
525 | /* | |
526 | * Ok, everything is just fine now | |
527 | */ | |
1f403624 | 528 | md_set_array_sectors(mddev, multipath_size(mddev, 0, 0)); |
7a5febe9 N |
529 | |
530 | mddev->queue->unplug_fn = multipath_unplug; | |
0d129228 N |
531 | mddev->queue->backing_dev_info.congested_fn = multipath_congested; |
532 | mddev->queue->backing_dev_info.congested_data = mddev; | |
ac5e7113 | 533 | md_integrity_register(mddev); |
1da177e4 LT |
534 | return 0; |
535 | ||
536 | out_free_conf: | |
537 | if (conf->pool) | |
538 | mempool_destroy(conf->pool); | |
990a8baf | 539 | kfree(conf->multipaths); |
1da177e4 LT |
540 | kfree(conf); |
541 | mddev->private = NULL; | |
542 | out: | |
543 | return -EIO; | |
544 | } | |
545 | ||
546 | ||
547 | static int multipath_stop (mddev_t *mddev) | |
548 | { | |
070ec55d | 549 | multipath_conf_t *conf = mddev->private; |
1da177e4 LT |
550 | |
551 | md_unregister_thread(mddev->thread); | |
552 | mddev->thread = NULL; | |
553 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ | |
554 | mempool_destroy(conf->pool); | |
555 | kfree(conf->multipaths); | |
556 | kfree(conf); | |
557 | mddev->private = NULL; | |
558 | return 0; | |
559 | } | |
560 | ||
2604b703 | 561 | static struct mdk_personality multipath_personality = |
1da177e4 LT |
562 | { |
563 | .name = "multipath", | |
2604b703 | 564 | .level = LEVEL_MULTIPATH, |
1da177e4 LT |
565 | .owner = THIS_MODULE, |
566 | .make_request = multipath_make_request, | |
567 | .run = multipath_run, | |
568 | .stop = multipath_stop, | |
569 | .status = multipath_status, | |
570 | .error_handler = multipath_error, | |
571 | .hot_add_disk = multipath_add_disk, | |
572 | .hot_remove_disk= multipath_remove_disk, | |
80c3a6ce | 573 | .size = multipath_size, |
1da177e4 LT |
574 | }; |
575 | ||
576 | static int __init multipath_init (void) | |
577 | { | |
2604b703 | 578 | return register_md_personality (&multipath_personality); |
1da177e4 LT |
579 | } |
580 | ||
581 | static void __exit multipath_exit (void) | |
582 | { | |
2604b703 | 583 | unregister_md_personality (&multipath_personality); |
1da177e4 LT |
584 | } |
585 | ||
586 | module_init(multipath_init); | |
587 | module_exit(multipath_exit); | |
588 | MODULE_LICENSE("GPL"); | |
0efb9e61 | 589 | MODULE_DESCRIPTION("simple multi-path personality for MD"); |
1da177e4 | 590 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ |
d9d166c2 | 591 | MODULE_ALIAS("md-multipath"); |
2604b703 | 592 | MODULE_ALIAS("md-level--4"); |