blob: 69244de2036b404d818193bd980894fbc2220fcf [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
NeilBrownbff61972009-03-31 14:33:13 +110022#include <linux/blkdev.h>
Paul Gortmaker056075c2011-07-03 13:58:33 -040023#include <linux/module.h>
NeilBrownbff61972009-03-31 14:33:13 +110024#include <linux/raid/md_u.h>
NeilBrownbff61972009-03-31 14:33:13 +110025#include <linux/seq_file.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090026#include <linux/slab.h>
NeilBrown43b2e5d2009-03-31 14:33:13 +110027#include "md.h"
Christoph Hellwigef740c32009-03-31 14:27:03 +110028#include "multipath.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30#define MAX_WORK_PER_DISK 128
31
32#define NR_RESERVED_BUFS 32
33
NeilBrown69724e22011-10-11 16:48:57 +110034static int multipath_map (struct mpconf *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
36 int i, disks = conf->raid_disks;
37
38 /*
NeilBrownf72ffdd2014-09-30 14:23:59 +100039 * Later we do read balancing on the read side
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 * now we use the first available disk.
41 */
42
43 rcu_read_lock();
44 for (i = 0; i < disks; i++) {
NeilBrown3cb03002011-10-11 16:45:26 +110045 struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
NeilBrownb2d444d2005-11-08 21:39:31 -080046 if (rdev && test_bit(In_sync, &rdev->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 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
58static void multipath_reschedule_retry (struct multipath_bh *mp_bh)
59{
60 unsigned long flags;
NeilBrownfd01b882011-10-11 16:47:53 +110061 struct mddev *mddev = mp_bh->mddev;
NeilBrown69724e22011-10-11 16:48:57 +110062 struct mpconf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070070/*
71 * multipath_end_bh_io() is called when we have finished servicing a multipathed
72 * operation and are ready to return a success/failure code to the buffer
73 * cache layer.
74 */
75static void multipath_end_bh_io (struct multipath_bh *mp_bh, int err)
76{
77 struct bio *bio = mp_bh->master_bio;
NeilBrown69724e22011-10-11 16:48:57 +110078 struct mpconf *conf = mp_bh->mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Christoph Hellwig4246a0b2015-07-20 15:29:37 +020080 bio->bi_error = err;
81 bio_endio(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 mempool_free(mp_bh, conf->pool);
83}
84
Christoph Hellwig4246a0b2015-07-20 15:29:37 +020085static void multipath_end_request(struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -070086{
H Hartley Sweeten7b928132010-03-08 16:02:40 +110087 struct multipath_bh *mp_bh = bio->bi_private;
NeilBrown69724e22011-10-11 16:48:57 +110088 struct mpconf *conf = mp_bh->mddev->private;
NeilBrown3cb03002011-10-11 16:45:26 +110089 struct md_rdev *rdev = conf->multipaths[mp_bh->path].rdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Christoph Hellwig4246a0b2015-07-20 15:29:37 +020091 if (!bio->bi_error)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 multipath_end_bh_io(mp_bh, 0);
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +020093 else if (!(bio->bi_rw & REQ_RAHEAD)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 /*
95 * oops, IO error:
96 */
97 char b[BDEVNAME_SIZE];
98 md_error (mp_bh->mddev, rdev);
NeilBrownf72ffdd2014-09-30 14:23:59 +100099 printk(KERN_ERR "multipath: %s: rescheduling sector %llu\n",
100 bdevname(rdev->bdev,b),
Kent Overstreet4f024f32013-10-11 15:44:27 -0700101 (unsigned long long)bio->bi_iter.bi_sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 multipath_reschedule_retry(mp_bh);
103 } else
Christoph Hellwig4246a0b2015-07-20 15:29:37 +0200104 multipath_end_bh_io(mp_bh, bio->bi_error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 rdev_dec_pending(rdev, conf->mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106}
107
Linus Torvaldsb4fdcb02011-11-04 17:06:58 -0700108static void multipath_make_request(struct mddev *mddev, struct bio * bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
NeilBrown69724e22011-10-11 16:48:57 +1100110 struct mpconf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 struct multipath_bh * mp_bh;
112 struct multipath_info *multipath;
113
Tejun Heoe9c74692010-09-03 11:56:18 +0200114 if (unlikely(bio->bi_rw & REQ_FLUSH)) {
115 md_flush_request(mddev, bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200116 return;
NeilBrowne5dcdd82005-09-09 16:23:41 -0700117 }
118
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 mp_bh = mempool_alloc(conf->pool, GFP_NOIO);
120
121 mp_bh->master_bio = bio;
122 mp_bh->mddev = mddev;
123
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 mp_bh->path = multipath_map(conf);
125 if (mp_bh->path < 0) {
Christoph Hellwig4246a0b2015-07-20 15:29:37 +0200126 bio_io_error(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 mempool_free(mp_bh, conf->pool);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200128 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 }
130 multipath = conf->multipaths + mp_bh->path;
131
Ming Leifafcde32016-03-12 09:29:40 +0800132 bio_init(&mp_bh->bio);
133 __bio_clone_fast(&mp_bh->bio, bio);
134
Kent Overstreet4f024f32013-10-11 15:44:27 -0700135 mp_bh->bio.bi_iter.bi_sector += multipath->rdev->data_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 mp_bh->bio.bi_bdev = multipath->rdev->bdev;
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200137 mp_bh->bio.bi_rw |= REQ_FAILFAST_TRANSPORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 mp_bh->bio.bi_end_io = multipath_end_request;
139 mp_bh->bio.bi_private = mp_bh;
140 generic_make_request(&mp_bh->bio);
Christoph Hellwig5a7bbad2011-09-12 12:12:01 +0200141 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142}
143
NeilBrown40cf2122016-06-02 16:19:52 +1000144static void multipath_status(struct seq_file *seq, struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
NeilBrown69724e22011-10-11 16:48:57 +1100146 struct mpconf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 int i;
NeilBrownf72ffdd2014-09-30 14:23:59 +1000148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 seq_printf (seq, " [%d/%d] [", conf->raid_disks,
NeilBrown92f861a2011-05-11 14:38:02 +1000150 conf->raid_disks - mddev->degraded);
NeilBrown40cf2122016-06-02 16:19:52 +1000151 rcu_read_lock();
152 for (i = 0; i < conf->raid_disks; i++) {
153 struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
154 seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
155 }
156 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 seq_printf (seq, "]");
158}
159
NeilBrown5c675f82014-12-15 12:56:56 +1100160static int multipath_congested(struct mddev *mddev, int bits)
NeilBrown0d129222006-10-03 01:15:54 -0700161{
NeilBrown69724e22011-10-11 16:48:57 +1100162 struct mpconf *conf = mddev->private;
NeilBrown0d129222006-10-03 01:15:54 -0700163 int i, ret = 0;
164
165 rcu_read_lock();
166 for (i = 0; i < mddev->raid_disks ; i++) {
NeilBrown3cb03002011-10-11 16:45:26 +1100167 struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
NeilBrown0d129222006-10-03 01:15:54 -0700168 if (rdev && !test_bit(Faulty, &rdev->flags)) {
Jens Axboe165125e2007-07-24 09:28:11 +0200169 struct request_queue *q = bdev_get_queue(rdev->bdev);
NeilBrown0d129222006-10-03 01:15:54 -0700170
171 ret |= bdi_congested(&q->backing_dev_info, bits);
172 /* Just like multipath_map, we just check the
173 * first available device
174 */
175 break;
176 }
177 }
178 rcu_read_unlock();
179 return ret;
180}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182/*
183 * Careful, this can execute in IRQ contexts as well!
184 */
NeilBrownfd01b882011-10-11 16:47:53 +1100185static void multipath_error (struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
NeilBrown69724e22011-10-11 16:48:57 +1100187 struct mpconf *conf = mddev->private;
NeilBrown6f8d0c72011-05-11 14:38:44 +1000188 char b[BDEVNAME_SIZE];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
NeilBrown92f861a2011-05-11 14:38:02 +1000190 if (conf->raid_disks - mddev->degraded <= 1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 /*
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 */
NeilBrownf72ffdd2014-09-30 14:23:59 +1000196 printk(KERN_ALERT
NeilBrown6f8d0c72011-05-11 14:38:44 +1000197 "multipath: only one IO path left and IO error.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 /* leave it active... it's all we have */
NeilBrown6f8d0c72011-05-11 14:38:44 +1000199 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 }
NeilBrown6f8d0c72011-05-11 14:38:44 +1000201 /*
202 * Mark disk as unusable
203 */
204 if (test_and_clear_bit(In_sync, &rdev->flags)) {
205 unsigned long flags;
206 spin_lock_irqsave(&conf->device_lock, flags);
207 mddev->degraded++;
208 spin_unlock_irqrestore(&conf->device_lock, flags);
209 }
210 set_bit(Faulty, &rdev->flags);
211 set_bit(MD_CHANGE_DEVS, &mddev->flags);
212 printk(KERN_ALERT "multipath: IO failure on %s,"
213 " disabling IO path.\n"
214 "multipath: Operation continuing"
215 " on %d IO paths.\n",
216 bdevname(rdev->bdev, b),
217 conf->raid_disks - mddev->degraded);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218}
219
NeilBrown69724e22011-10-11 16:48:57 +1100220static void print_multipath_conf (struct mpconf *conf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
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 }
NeilBrown92f861a2011-05-11 14:38:02 +1000230 printk(" --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 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",
NeilBrownb2d444d2005-11-08 21:39:31 -0800238 i,!test_bit(Faulty, &tmp->rdev->flags),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 bdevname(tmp->rdev->bdev,b));
240 }
241}
242
NeilBrownfd01b882011-10-11 16:47:53 +1100243static int multipath_add_disk(struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244{
NeilBrown69724e22011-10-11 16:48:57 +1100245 struct mpconf *conf = mddev->private;
Jesper Juhl352d7682006-01-09 20:54:44 -0800246 struct request_queue *q;
Neil Brown199050e2008-06-28 08:31:33 +1000247 int err = -EEXIST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 int path;
249 struct multipath_info *p;
Neil Brown6c2fce22008-06-28 08:31:31 +1000250 int first = 0;
251 int last = mddev->raid_disks - 1;
252
253 if (rdev->raid_disk >= 0)
254 first = last = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 print_multipath_conf(conf);
257
Neil Brown6c2fce22008-06-28 08:31:31 +1000258 for (path = first; path <= last; path++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 if ((p=conf->multipaths+path)->rdev == NULL) {
Jesper Juhl352d7682006-01-09 20:54:44 -0800260 q = rdev->bdev->bd_disk->queue;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +1000261 disk_stack_limits(mddev->gendisk, rdev->bdev,
262 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
Dan Williams1501efa2016-01-13 16:00:07 -0800264 err = md_integrity_add_rdev(rdev, mddev);
265 if (err)
266 break;
NeilBrown6f8d0c72011-05-11 14:38:44 +1000267 spin_lock_irq(&conf->device_lock);
NeilBrown750a8f3e82006-10-28 10:38:31 -0700268 mddev->degraded--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 rdev->raid_disk = path;
NeilBrownb2d444d2005-11-08 21:39:31 -0800270 set_bit(In_sync, &rdev->flags);
NeilBrown6f8d0c72011-05-11 14:38:44 +1000271 spin_unlock_irq(&conf->device_lock);
Suzanne Woodd6065f72005-11-08 21:39:27 -0800272 rcu_assign_pointer(p->rdev, rdev);
Neil Brown199050e2008-06-28 08:31:33 +1000273 err = 0;
274 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 }
276
277 print_multipath_conf(conf);
Neil Brown199050e2008-06-28 08:31:33 +1000278
279 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280}
281
NeilBrownb8321b62011-12-23 10:17:51 +1100282static int multipath_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283{
NeilBrown69724e22011-10-11 16:48:57 +1100284 struct mpconf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 int err = 0;
NeilBrownb8321b62011-12-23 10:17:51 +1100286 int number = rdev->raid_disk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 struct multipath_info *p = conf->multipaths + number;
288
289 print_multipath_conf(conf);
290
NeilBrownb8321b62011-12-23 10:17:51 +1100291 if (rdev == p->rdev) {
NeilBrownb2d444d2005-11-08 21:39:31 -0800292 if (test_bit(In_sync, &rdev->flags) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 atomic_read(&rdev->nr_pending)) {
NeilBrowndfc70642008-05-23 13:04:39 -0700294 printk(KERN_ERR "hot-remove-disk, slot %d is identified"
295 " but is still operational!\n", number);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 err = -EBUSY;
297 goto abort;
298 }
299 p->rdev = NULL;
Paul E. McKenneyfbd568a3e2005-05-01 08:59:04 -0700300 synchronize_rcu();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if (atomic_read(&rdev->nr_pending)) {
302 /* lost the race, try later */
303 err = -EBUSY;
304 p->rdev = rdev;
Andre Nollac5e7112009-08-03 10:59:47 +1000305 goto abort;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 }
Martin K. Petersena91a2782011-03-17 11:11:05 +0100307 err = md_integrity_register(mddev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 }
309abort:
310
311 print_multipath_conf(conf);
312 return err;
313}
314
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315/*
316 * This is a kernel thread which:
317 *
318 * 1. Retries failed read operations on working multipaths.
319 * 2. Updates the raid superblock when problems encounter.
320 * 3. Performs writes following reads for array syncronising.
321 */
322
Shaohua Li4ed87312012-10-11 13:34:00 +1100323static void multipathd(struct md_thread *thread)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324{
Shaohua Li4ed87312012-10-11 13:34:00 +1100325 struct mddev *mddev = thread->mddev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 struct multipath_bh *mp_bh;
327 struct bio *bio;
328 unsigned long flags;
NeilBrown69724e22011-10-11 16:48:57 +1100329 struct mpconf *conf = mddev->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 struct list_head *head = &conf->retry_list;
331
332 md_check_recovery(mddev);
333 for (;;) {
334 char b[BDEVNAME_SIZE];
335 spin_lock_irqsave(&conf->device_lock, flags);
336 if (list_empty(head))
337 break;
338 mp_bh = list_entry(head->prev, struct multipath_bh, retry_list);
339 list_del(head->prev);
340 spin_unlock_irqrestore(&conf->device_lock, flags);
341
342 bio = &mp_bh->bio;
Kent Overstreet4f024f32013-10-11 15:44:27 -0700343 bio->bi_iter.bi_sector = mp_bh->master_bio->bi_iter.bi_sector;
NeilBrownf72ffdd2014-09-30 14:23:59 +1000344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 if ((mp_bh->path = multipath_map (conf))<0) {
346 printk(KERN_ALERT "multipath: %s: unrecoverable IO read"
347 " error for block %llu\n",
348 bdevname(bio->bi_bdev,b),
Kent Overstreet4f024f32013-10-11 15:44:27 -0700349 (unsigned long long)bio->bi_iter.bi_sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 multipath_end_bh_io(mp_bh, -EIO);
351 } else {
352 printk(KERN_ERR "multipath: %s: redirecting sector %llu"
353 " to another IO path\n",
354 bdevname(bio->bi_bdev,b),
Kent Overstreet4f024f32013-10-11 15:44:27 -0700355 (unsigned long long)bio->bi_iter.bi_sector);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 *bio = *(mp_bh->master_bio);
Kent Overstreet4f024f32013-10-11 15:44:27 -0700357 bio->bi_iter.bi_sector +=
358 conf->multipaths[mp_bh->path].rdev->data_offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359 bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev;
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200360 bio->bi_rw |= REQ_FAILFAST_TRANSPORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 bio->bi_end_io = multipath_end_request;
362 bio->bi_private = mp_bh;
363 generic_make_request(bio);
364 }
365 }
366 spin_unlock_irqrestore(&conf->device_lock, flags);
367}
368
NeilBrownfd01b882011-10-11 16:47:53 +1100369static sector_t multipath_size(struct mddev *mddev, sector_t sectors, int raid_disks)
Dan Williams80c3a6c2009-03-17 18:10:40 -0700370{
371 WARN_ONCE(sectors || raid_disks,
372 "%s does not support generic reshape\n", __func__);
373
374 return mddev->dev_sectors;
375}
376
NeilBrownfd01b882011-10-11 16:47:53 +1100377static int multipath_run (struct mddev *mddev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378{
NeilBrown69724e22011-10-11 16:48:57 +1100379 struct mpconf *conf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 int disk_idx;
381 struct multipath_info *disk;
NeilBrown3cb03002011-10-11 16:45:26 +1100382 struct md_rdev *rdev;
NeilBrown92f861a2011-05-11 14:38:02 +1000383 int working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
Andre Noll0894cc32009-06-18 08:49:23 +1000385 if (md_check_no_bitmap(mddev))
386 return -EINVAL;
387
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 if (mddev->level != LEVEL_MULTIPATH) {
389 printk("multipath: %s: raid level not set to multipath IO (%d)\n",
390 mdname(mddev), mddev->level);
391 goto out;
392 }
393 /*
394 * copy the already verified devices into our private MULTIPATH
395 * bookkeeping area. [whatever we allocate in multipath_run(),
NeilBrownafa0f552014-12-15 12:56:58 +1100396 * should be freed in multipath_free()]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 */
398
NeilBrown69724e22011-10-11 16:48:57 +1100399 conf = kzalloc(sizeof(struct mpconf), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 mddev->private = conf;
401 if (!conf) {
NeilBrownf72ffdd2014-09-30 14:23:59 +1000402 printk(KERN_ERR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 "multipath: couldn't allocate memory for %s\n",
404 mdname(mddev));
405 goto out;
406 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
NeilBrown9ffae0c2006-01-06 00:20:32 -0800408 conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 GFP_KERNEL);
410 if (!conf->multipaths) {
NeilBrownf72ffdd2014-09-30 14:23:59 +1000411 printk(KERN_ERR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 "multipath: couldn't allocate memory for %s\n",
413 mdname(mddev));
414 goto out_free_conf;
415 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
NeilBrown92f861a2011-05-11 14:38:02 +1000417 working_disks = 0;
NeilBrowndafb20f2012-03-19 12:46:39 +1100418 rdev_for_each(rdev, mddev) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 disk_idx = rdev->raid_disk;
420 if (disk_idx < 0 ||
421 disk_idx >= mddev->raid_disks)
422 continue;
423
424 disk = conf->multipaths + disk_idx;
425 disk->rdev = rdev;
Martin K. Petersen8f6c2e42009-07-01 11:13:45 +1000426 disk_stack_limits(mddev->gendisk, rdev->bdev,
427 rdev->data_offset << 9);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428
NeilBrownb2d444d2005-11-08 21:39:31 -0800429 if (!test_bit(Faulty, &rdev->flags))
NeilBrown92f861a2011-05-11 14:38:02 +1000430 working_disks++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 }
432
433 conf->raid_disks = mddev->raid_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 conf->mddev = mddev;
435 spin_lock_init(&conf->device_lock);
436 INIT_LIST_HEAD(&conf->retry_list);
437
NeilBrown92f861a2011-05-11 14:38:02 +1000438 if (!working_disks) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 printk(KERN_ERR "multipath: no operational IO paths for %s\n",
440 mdname(mddev));
441 goto out_free_conf;
442 }
NeilBrown92f861a2011-05-11 14:38:02 +1000443 mddev->degraded = conf->raid_disks - working_disks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
Sage Weilbbba8092009-09-21 17:02:55 -0700445 conf->pool = mempool_create_kmalloc_pool(NR_RESERVED_BUFS,
Matthew Dobson26b6e052006-03-26 01:37:48 -0800446 sizeof(struct multipath_bh));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 if (conf->pool == NULL) {
NeilBrownf72ffdd2014-09-30 14:23:59 +1000448 printk(KERN_ERR
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 "multipath: couldn't allocate memory for %s\n",
450 mdname(mddev));
451 goto out_free_conf;
452 }
453
454 {
NeilBrown02326052012-07-03 15:56:52 +1000455 mddev->thread = md_register_thread(multipathd, mddev,
456 "multipath");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 if (!mddev->thread) {
458 printk(KERN_ERR "multipath: couldn't allocate thread"
459 " for %s\n", mdname(mddev));
460 goto out_free_conf;
461 }
462 }
463
NeilBrownf72ffdd2014-09-30 14:23:59 +1000464 printk(KERN_INFO
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 "multipath: array %s active with %d out of %d IO paths\n",
NeilBrown92f861a2011-05-11 14:38:02 +1000466 mdname(mddev), conf->raid_disks - mddev->degraded,
467 mddev->raid_disks);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 /*
469 * Ok, everything is just fine now
470 */
Dan Williams1f403622009-03-31 14:59:03 +1100471 md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
NeilBrown7a5febe2005-05-16 21:53:16 -0700472
Martin K. Petersena91a2782011-03-17 11:11:05 +0100473 if (md_integrity_register(mddev))
474 goto out_free_conf;
475
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 return 0;
477
478out_free_conf:
Julia Lawall644df1a2015-09-13 14:15:10 +0200479 mempool_destroy(conf->pool);
Jesper Juhl990a8ba2005-06-21 17:17:30 -0700480 kfree(conf->multipaths);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 kfree(conf);
482 mddev->private = NULL;
483out:
484 return -EIO;
485}
486
NeilBrownafa0f552014-12-15 12:56:58 +1100487static void multipath_free(struct mddev *mddev, void *priv)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488{
NeilBrownafa0f552014-12-15 12:56:58 +1100489 struct mpconf *conf = priv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 mempool_destroy(conf->pool);
492 kfree(conf->multipaths);
493 kfree(conf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494}
495
NeilBrown84fc4b52011-10-11 16:49:58 +1100496static struct md_personality multipath_personality =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497{
498 .name = "multipath",
NeilBrown2604b702006-01-06 00:20:36 -0800499 .level = LEVEL_MULTIPATH,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 .owner = THIS_MODULE,
501 .make_request = multipath_make_request,
502 .run = multipath_run,
NeilBrownafa0f552014-12-15 12:56:58 +1100503 .free = multipath_free,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 .status = multipath_status,
505 .error_handler = multipath_error,
506 .hot_add_disk = multipath_add_disk,
507 .hot_remove_disk= multipath_remove_disk,
Dan Williams80c3a6c2009-03-17 18:10:40 -0700508 .size = multipath_size,
NeilBrown5c675f82014-12-15 12:56:56 +1100509 .congested = multipath_congested,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510};
511
512static int __init multipath_init (void)
513{
NeilBrown2604b702006-01-06 00:20:36 -0800514 return register_md_personality (&multipath_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515}
516
517static void __exit multipath_exit (void)
518{
NeilBrown2604b702006-01-06 00:20:36 -0800519 unregister_md_personality (&multipath_personality);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520}
521
522module_init(multipath_init);
523module_exit(multipath_exit);
524MODULE_LICENSE("GPL");
NeilBrown0efb9e62009-12-14 12:49:58 +1100525MODULE_DESCRIPTION("simple multi-path personality for MD");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526MODULE_ALIAS("md-personality-7"); /* MULTIPATH */
NeilBrownd9d166c2006-01-06 00:20:51 -0800527MODULE_ALIAS("md-multipath");
NeilBrown2604b702006-01-06 00:20:36 -0800528MODULE_ALIAS("md-level--4");