blob: c4779ccba1c39bf1ab3f7454706868245f95ea0e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070038static 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++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -080049 mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -080050 if (rdev && test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 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
62static 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 */
80static 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
NeilBrown6712ecf2007-09-27 12:47:43 +020085 bio_endio(bio, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 mempool_free(mp_bh, conf->pool);
87}
88
NeilBrown6712ecf2007-09-27 12:47:43 +020089static void multipath_end_request(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
113static 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++) {
Suzanne Woodd6065f72005-11-08 21:39:27 -0800120 mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -0800121 if (rdev && !test_bit(Faulty, &rdev->flags)
122 && atomic_read(&rdev->nr_pending)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200123 struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 atomic_inc(&rdev->nr_pending);
126 rcu_read_unlock();
127
Alan D. Brunelle2ad8b1e2007-11-07 14:26:56 -0500128 blk_unplug(r_queue);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129
130 rdev_dec_pending(rdev, mddev);
131 rcu_read_lock();
132 }
133 }
134 rcu_read_unlock();
135}
136
Jens Axboe165125e2007-07-24 09:28:11 +0200137static void multipath_unplug(struct request_queue *q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{
139 unplug_slaves(q->queuedata);
140}
141
142
Jens Axboe165125e2007-07-24 09:28:11 +0200143static int multipath_make_request (struct request_queue *q, struct bio * bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
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;
Jens Axboea3623572005-11-01 09:26:16 +0100149 const int rw = bio_data_dir(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
NeilBrowne5dcdd82005-09-09 16:23:41 -0700151 if (unlikely(bio_barrier(bio))) {
NeilBrown6712ecf2007-09-27 12:47:43 +0200152 bio_endio(bio, -EOPNOTSUPP);
NeilBrowne5dcdd82005-09-09 16:23:41 -0700153 return 0;
154 }
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
157
158 mp_bh->master_bio = bio;
159 mp_bh->mddev = mddev;
160
Jens Axboea3623572005-11-01 09:26:16 +0100161 disk_stat_inc(mddev->gendisk, ios[rw]);
162 disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163
164 mp_bh->path = multipath_map(conf);
165 if (mp_bh->path < 0) {
NeilBrown6712ecf2007-09-27 12:47:43 +0200166 bio_endio(bio, -EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 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;
175 mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST);
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
182static void multipath_status (struct seq_file *seq, mddev_t *mddev)
183{
184 multipath_conf_t *conf = mddev_to_conf(mddev);
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 &&
NeilBrownb2d444d2005-11-08 21:39:31 -0800192 test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 seq_printf (seq, "]");
194}
195
NeilBrown0d129222006-10-03 01:15:54 -0700196static int multipath_congested(void *data, int bits)
197{
198 mddev_t *mddev = data;
199 multipath_conf_t *conf = mddev_to_conf(mddev);
200 int i, ret = 0;
201
202 rcu_read_lock();
203 for (i = 0; i < mddev->raid_disks ; i++) {
204 mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev);
205 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200206 struct request_queue *q = bdev_get_queue(rdev->bdev);
NeilBrown0d129222006-10-03 01:15:54 -0700207
208 ret |= bdi_congested(&q->backing_dev_info, bits);
209 /* Just like multipath_map, we just check the
210 * first available device
211 */
212 break;
213 }
214 }
215 rcu_read_unlock();
216 return ret;
217}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
219/*
220 * Careful, this can execute in IRQ contexts as well!
221 */
222static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev)
223{
224 multipath_conf_t *conf = mddev_to_conf(mddev);
225
226 if (conf->working_disks <= 1) {
227 /*
228 * Uh oh, we can do nothing if this is our last path, but
229 * first check if this is a queued request for a device
230 * which has just failed.
231 */
232 printk(KERN_ALERT
233 "multipath: only one IO path left and IO error.\n");
234 /* leave it active... it's all we have */
235 } else {
236 /*
237 * Mark disk as unusable
238 */
NeilBrownb2d444d2005-11-08 21:39:31 -0800239 if (!test_bit(Faulty, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 char b[BDEVNAME_SIZE];
NeilBrownb2d444d2005-11-08 21:39:31 -0800241 clear_bit(In_sync, &rdev->flags);
242 set_bit(Faulty, &rdev->flags);
NeilBrown850b2b42006-10-03 01:15:46 -0700243 set_bit(MD_CHANGE_DEVS, &mddev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 conf->working_disks--;
NeilBrown750a8f32006-10-28 10:38:31 -0700245 mddev->degraded++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 printk(KERN_ALERT "multipath: IO failure on %s,"
Nick Andrewd7a420c2008-04-28 02:15:55 -0700247 " disabling IO path.\n"
248 "multipath: Operation continuing"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 " on %d IO paths.\n",
250 bdevname (rdev->bdev,b),
251 conf->working_disks);
252 }
253 }
254}
255
256static 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",
NeilBrownb2d444d2005-11-08 21:39:31 -0800274 i,!test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 bdevname(tmp->rdev->bdev,b));
276 }
277}
278
279
280static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
281{
282 multipath_conf_t *conf = mddev->private;
Jesper Juhl352d7682006-01-09 20:54:44 -0800283 struct request_queue *q;
Neil Brown199050e2008-06-28 08:31:33 +1000284 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 int path;
286 struct multipath_info *p;
Neil Brown6c2fce22008-06-28 08:31:31 +1000287 int first = 0;
288 int last = mddev->raid_disks - 1;
289
290 if (rdev->raid_disk >= 0)
291 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292
293 print_multipath_conf(conf);
294
Neil Brown6c2fce22008-06-28 08:31:31 +1000295 for (path = first; path <= last; path++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 if ((p=conf->multipaths+path)->rdev == NULL) {
Jesper Juhl352d7682006-01-09 20:54:44 -0800297 q = rdev->bdev->bd_disk->queue;
298 blk_queue_stack_limits(mddev->queue, q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
300 /* as we don't honour merge_bvec_fn, we must never risk
301 * violating it, so limit ->max_sector to one PAGE, as
302 * a one page request is never in violation.
303 * (Note: it is very unlikely that a device with
304 * merge_bvec_fn will be involved in multipath.)
305 */
Jesper Juhl352d7682006-01-09 20:54:44 -0800306 if (q->merge_bvec_fn &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 mddev->queue->max_sectors > (PAGE_SIZE>>9))
308 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
309
310 conf->working_disks++;
NeilBrown750a8f32006-10-28 10:38:31 -0700311 mddev->degraded--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 rdev->raid_disk = path;
NeilBrownb2d444d2005-11-08 21:39:31 -0800313 set_bit(In_sync, &rdev->flags);
Suzanne Woodd6065f72005-11-08 21:39:27 -0800314 rcu_assign_pointer(p->rdev, rdev);
Neil Brown199050e2008-06-28 08:31:33 +1000315 err = 0;
316 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
318
319 print_multipath_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +1000320
321 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322}
323
324static int multipath_remove_disk(mddev_t *mddev, int number)
325{
326 multipath_conf_t *conf = mddev->private;
327 int err = 0;
328 mdk_rdev_t *rdev;
329 struct multipath_info *p = conf->multipaths + number;
330
331 print_multipath_conf(conf);
332
333 rdev = p->rdev;
334 if (rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -0800335 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 atomic_read(&rdev->nr_pending)) {
NeilBrowndfc70642008-05-23 13:04:39 -0700337 printk(KERN_ERR "hot-remove-disk, slot %d is identified"
338 " but is still operational!\n", number);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 err = -EBUSY;
340 goto abort;
341 }
342 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -0700343 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 if (atomic_read(&rdev->nr_pending)) {
345 /* lost the race, try later */
346 err = -EBUSY;
347 p->rdev = rdev;
348 }
349 }
350abort:
351
352 print_multipath_conf(conf);
353 return err;
354}
355
356
357
358/*
359 * This is a kernel thread which:
360 *
361 * 1. Retries failed read operations on working multipaths.
362 * 2. Updates the raid superblock when problems encounter.
363 * 3. Performs writes following reads for array syncronising.
364 */
365
366static void multipathd (mddev_t *mddev)
367{
368 struct multipath_bh *mp_bh;
369 struct bio *bio;
370 unsigned long flags;
371 multipath_conf_t *conf = mddev_to_conf(mddev);
372 struct list_head *head = &conf->retry_list;
373
374 md_check_recovery(mddev);
375 for (;;) {
376 char b[BDEVNAME_SIZE];
377 spin_lock_irqsave(&conf->device_lock, flags);
378 if (list_empty(head))
379 break;
380 mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
381 list_del(head->prev);
382 spin_unlock_irqrestore(&conf->device_lock, flags);
383
384 bio = &mp_bh->bio;
385 bio->bi_sector = mp_bh->master_bio->bi_sector;
386
387 if ((mp_bh->path = multipath_map (conf))<0) {
388 printk(KERN_ALERT "multipath: %s: unrecoverable IO read"
389 " error for block %llu\n",
390 bdevname(bio->bi_bdev,b),
391 (unsigned long long)bio->bi_sector);
392 multipath_end_bh_io(mp_bh, -EIO);
393 } else {
394 printk(KERN_ERR "multipath: %s: redirecting sector %llu"
395 " to another IO path\n",
396 bdevname(bio->bi_bdev,b),
397 (unsigned long long)bio->bi_sector);
398 *bio = *(mp_bh->master_bio);
399 bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset;
400 bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev;
401 bio->bi_rw |= (1 << BIO_RW_FAILFAST);
402 bio->bi_end_io = multipath_end_request;
403 bio->bi_private = mp_bh;
404 generic_make_request(bio);
405 }
406 }
407 spin_unlock_irqrestore(&conf->device_lock, flags);
408}
409
410static int multipath_run (mddev_t *mddev)
411{
412 multipath_conf_t *conf;
413 int disk_idx;
414 struct multipath_info *disk;
415 mdk_rdev_t *rdev;
416 struct list_head *tmp;
417
418 if (mddev->level != LEVEL_MULTIPATH) {
419 printk("multipath: %s: raid level not set to multipath IO (%d)\n",
420 mdname(mddev), mddev->level);
421 goto out;
422 }
423 /*
424 * copy the already verified devices into our private MULTIPATH
425 * bookkeeping area. [whatever we allocate in multipath_run(),
426 * should be freed in multipath_stop()]
427 */
Neil Browne7e72bf2008-05-14 16:05:54 -0700428 mddev->queue->queue_lock = &mddev->queue->__queue_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
NeilBrown9ffae0c2006-01-06 00:20:32 -0800430 conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 mddev->private = conf;
432 if (!conf) {
433 printk(KERN_ERR
434 "multipath: couldn't allocate memory for %s\n",
435 mdname(mddev));
436 goto out;
437 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
NeilBrown9ffae0c2006-01-06 00:20:32 -0800439 conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 GFP_KERNEL);
441 if (!conf->multipaths) {
442 printk(KERN_ERR
443 "multipath: couldn't allocate memory for %s\n",
444 mdname(mddev));
445 goto out_free_conf;
446 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 conf->working_disks = 0;
NeilBrownd089c6a2008-02-06 01:39:59 -0800449 rdev_for_each(rdev, tmp, mddev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 disk_idx = rdev->raid_disk;
451 if (disk_idx < 0 ||
452 disk_idx >= mddev->raid_disks)
453 continue;
454
455 disk = conf->multipaths + disk_idx;
456 disk->rdev = rdev;
457
458 blk_queue_stack_limits(mddev->queue,
459 rdev->bdev->bd_disk->queue);
460 /* as we don't honour merge_bvec_fn, we must never risk
461 * violating it, not that we ever expect a device with
462 * a merge_bvec_fn to be involved in multipath */
463 if (rdev->bdev->bd_disk->queue->merge_bvec_fn &&
464 mddev->queue->max_sectors > (PAGE_SIZE>>9))
465 blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);
466
NeilBrownb2d444d2005-11-08 21:39:31 -0800467 if (!test_bit(Faulty, &rdev->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 conf->working_disks++;
469 }
470
471 conf->raid_disks = mddev->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 conf->mddev = mddev;
473 spin_lock_init(&conf->device_lock);
474 INIT_LIST_HEAD(&conf->retry_list);
475
476 if (!conf->working_disks) {
477 printk(KERN_ERR "multipath: no operational IO paths for %s\n",
478 mdname(mddev));
479 goto out_free_conf;
480 }
NeilBrown2e333e82006-10-21 10:24:07 -0700481 mddev->degraded = conf->raid_disks - conf->working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
Matthew Dobson26b6e052006-03-26 01:37:48 -0800483 conf->pool = mempool_create_kzalloc_pool(NR_RESERVED_BUFS,
484 sizeof(struct multipath_bh));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 if (conf->pool == NULL) {
486 printk(KERN_ERR
487 "multipath: couldn't allocate memory for %s\n",
488 mdname(mddev));
489 goto out_free_conf;
490 }
491
492 {
493 mddev->thread = md_register_thread(multipathd, mddev, "%s_multipath");
494 if (!mddev->thread) {
495 printk(KERN_ERR "multipath: couldn't allocate thread"
496 " for %s\n", mdname(mddev));
497 goto out_free_conf;
498 }
499 }
500
501 printk(KERN_INFO
502 "multipath: array %s active with %d out of %d IO paths\n",
503 mdname(mddev), conf->working_disks, mddev->raid_disks);
504 /*
505 * Ok, everything is just fine now
506 */
Andre Nollf233ea52008-07-21 17:05:22 +1000507 mddev->array_sectors = mddev->size * 2;
NeilBrown7a5febe2005-05-16 21:53:16 -0700508
509 mddev->queue->unplug_fn = multipath_unplug;
NeilBrown0d129222006-10-03 01:15:54 -0700510 mddev->queue->backing_dev_info.congested_fn = multipath_congested;
511 mddev->queue->backing_dev_info.congested_data = mddev;
NeilBrown7a5febe2005-05-16 21:53:16 -0700512
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 return 0;
514
515out_free_conf:
516 if (conf->pool)
517 mempool_destroy(conf->pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -0700518 kfree(conf->multipaths);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 kfree(conf);
520 mddev->private = NULL;
521out:
522 return -EIO;
523}
524
525
526static int multipath_stop (mddev_t *mddev)
527{
528 multipath_conf_t *conf = mddev_to_conf(mddev);
529
530 md_unregister_thread(mddev->thread);
531 mddev->thread = NULL;
532 blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
533 mempool_destroy(conf->pool);
534 kfree(conf->multipaths);
535 kfree(conf);
536 mddev->private = NULL;
537 return 0;
538}
539
NeilBrown2604b702006-01-06 00:20:36 -0800540static struct mdk_personality multipath_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541{
542 .name = "multipath",
NeilBrown2604b702006-01-06 00:20:36 -0800543 .level = LEVEL_MULTIPATH,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 .owner = THIS_MODULE,
545 .make_request = multipath_make_request,
546 .run = multipath_run,
547 .stop = multipath_stop,
548 .status = multipath_status,
549 .error_handler = multipath_error,
550 .hot_add_disk = multipath_add_disk,
551 .hot_remove_disk= multipath_remove_disk,
552};
553
554static int __init multipath_init (void)
555{
NeilBrown2604b702006-01-06 00:20:36 -0800556 return register_md_personality (&multipath_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557}
558
559static void __exit multipath_exit (void)
560{
NeilBrown2604b702006-01-06 00:20:36 -0800561 unregister_md_personality (&multipath_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562}
563
564module_init(multipath_init);
565module_exit(multipath_exit);
566MODULE_LICENSE("GPL");
567MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
NeilBrownd9d166c2006-01-06 00:20:51 -0800568MODULE_ALIAS("md-multipath");
NeilBrown2604b702006-01-06 00:20:36 -0800569MODULE_ALIAS("md-level--4");