Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 38 | static void *mp_pool_alloc(gfp_t gfp_flags, void *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | { |
| 40 | struct multipath_bh *mpb; |
NeilBrown | 9ffae0c | 2006-01-06 00:20:32 -0800 | [diff] [blame] | 41 | mpb = kzalloc(sizeof(*mpb), gfp_flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | return mpb; |
| 43 | } |
| 44 | |
| 45 | static void mp_pool_free(void *mpb, void *data) |
| 46 | { |
| 47 | kfree(mpb); |
| 48 | } |
| 49 | |
| 50 | static int multipath_map (multipath_conf_t *conf) |
| 51 | { |
| 52 | int i, disks = conf->raid_disks; |
| 53 | |
| 54 | /* |
| 55 | * Later we do read balancing on the read side |
| 56 | * now we use the first available disk. |
| 57 | */ |
| 58 | |
| 59 | rcu_read_lock(); |
| 60 | for (i = 0; i < disks; i++) { |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 61 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 62 | if (rdev && test_bit(In_sync, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 63 | atomic_inc(&rdev->nr_pending); |
| 64 | rcu_read_unlock(); |
| 65 | return i; |
| 66 | } |
| 67 | } |
| 68 | rcu_read_unlock(); |
| 69 | |
| 70 | printk(KERN_ERR "multipath_map(): no more operational IO paths?\n"); |
| 71 | return (-1); |
| 72 | } |
| 73 | |
| 74 | static void multipath_reschedule_retry (struct multipath_bh *mp_bh) |
| 75 | { |
| 76 | unsigned long flags; |
| 77 | mddev_t *mddev = mp_bh->mddev; |
| 78 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 79 | |
| 80 | spin_lock_irqsave(&conf->device_lock, flags); |
| 81 | list_add(&mp_bh->retry_list, &conf->retry_list); |
| 82 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 83 | md_wakeup_thread(mddev->thread); |
| 84 | } |
| 85 | |
| 86 | |
| 87 | /* |
| 88 | * multipath_end_bh_io() is called when we have finished servicing a multipathed |
| 89 | * operation and are ready to return a success/failure code to the buffer |
| 90 | * cache layer. |
| 91 | */ |
| 92 | static void multipath_end_bh_io (struct multipath_bh *mp_bh, int err) |
| 93 | { |
| 94 | struct bio *bio = mp_bh->master_bio; |
| 95 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); |
| 96 | |
| 97 | bio_endio(bio, bio->bi_size, err); |
| 98 | mempool_free(mp_bh, conf->pool); |
| 99 | } |
| 100 | |
Adrian Bunk | 75c96f8 | 2005-05-05 16:16:09 -0700 | [diff] [blame] | 101 | static int multipath_end_request(struct bio *bio, unsigned int bytes_done, |
| 102 | int error) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | { |
| 104 | int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| 105 | struct multipath_bh * mp_bh = (struct multipath_bh *)(bio->bi_private); |
| 106 | multipath_conf_t *conf = mddev_to_conf(mp_bh->mddev); |
| 107 | mdk_rdev_t *rdev = conf->multipaths[mp_bh->path].rdev; |
| 108 | |
| 109 | if (bio->bi_size) |
| 110 | return 1; |
| 111 | |
| 112 | if (uptodate) |
| 113 | multipath_end_bh_io(mp_bh, 0); |
| 114 | else if (!bio_rw_ahead(bio)) { |
| 115 | /* |
| 116 | * oops, IO error: |
| 117 | */ |
| 118 | char b[BDEVNAME_SIZE]; |
| 119 | md_error (mp_bh->mddev, rdev); |
| 120 | printk(KERN_ERR "multipath: %s: rescheduling sector %llu\n", |
| 121 | bdevname(rdev->bdev,b), |
| 122 | (unsigned long long)bio->bi_sector); |
| 123 | multipath_reschedule_retry(mp_bh); |
| 124 | } else |
| 125 | multipath_end_bh_io(mp_bh, error); |
| 126 | rdev_dec_pending(rdev, conf->mddev); |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | static void unplug_slaves(mddev_t *mddev) |
| 131 | { |
| 132 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 133 | int i; |
| 134 | |
| 135 | rcu_read_lock(); |
| 136 | for (i=0; i<mddev->raid_disks; i++) { |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 137 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 138 | if (rdev && !test_bit(Faulty, &rdev->flags) |
| 139 | && atomic_read(&rdev->nr_pending)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | request_queue_t *r_queue = bdev_get_queue(rdev->bdev); |
| 141 | |
| 142 | atomic_inc(&rdev->nr_pending); |
| 143 | rcu_read_unlock(); |
| 144 | |
| 145 | if (r_queue->unplug_fn) |
| 146 | r_queue->unplug_fn(r_queue); |
| 147 | |
| 148 | rdev_dec_pending(rdev, mddev); |
| 149 | rcu_read_lock(); |
| 150 | } |
| 151 | } |
| 152 | rcu_read_unlock(); |
| 153 | } |
| 154 | |
| 155 | static void multipath_unplug(request_queue_t *q) |
| 156 | { |
| 157 | unplug_slaves(q->queuedata); |
| 158 | } |
| 159 | |
| 160 | |
| 161 | static int multipath_make_request (request_queue_t *q, struct bio * bio) |
| 162 | { |
| 163 | mddev_t *mddev = q->queuedata; |
| 164 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 165 | struct multipath_bh * mp_bh; |
| 166 | struct multipath_info *multipath; |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 167 | const int rw = bio_data_dir(bio); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | |
NeilBrown | e5dcdd8 | 2005-09-09 16:23:41 -0700 | [diff] [blame] | 169 | if (unlikely(bio_barrier(bio))) { |
| 170 | bio_endio(bio, bio->bi_size, -EOPNOTSUPP); |
| 171 | return 0; |
| 172 | } |
| 173 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | mp_bh = mempool_alloc(conf->pool, GFP_NOIO); |
| 175 | |
| 176 | mp_bh->master_bio = bio; |
| 177 | mp_bh->mddev = mddev; |
| 178 | |
Jens Axboe | a362357 | 2005-11-01 09:26:16 +0100 | [diff] [blame] | 179 | disk_stat_inc(mddev->gendisk, ios[rw]); |
| 180 | disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
| 182 | mp_bh->path = multipath_map(conf); |
| 183 | if (mp_bh->path < 0) { |
| 184 | bio_endio(bio, bio->bi_size, -EIO); |
| 185 | mempool_free(mp_bh, conf->pool); |
| 186 | return 0; |
| 187 | } |
| 188 | multipath = conf->multipaths + mp_bh->path; |
| 189 | |
| 190 | mp_bh->bio = *bio; |
| 191 | mp_bh->bio.bi_sector += multipath->rdev->data_offset; |
| 192 | mp_bh->bio.bi_bdev = multipath->rdev->bdev; |
| 193 | mp_bh->bio.bi_rw |= (1 << BIO_RW_FAILFAST); |
| 194 | mp_bh->bio.bi_end_io = multipath_end_request; |
| 195 | mp_bh->bio.bi_private = mp_bh; |
| 196 | generic_make_request(&mp_bh->bio); |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static void multipath_status (struct seq_file *seq, mddev_t *mddev) |
| 201 | { |
| 202 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 203 | int i; |
| 204 | |
| 205 | seq_printf (seq, " [%d/%d] [", conf->raid_disks, |
| 206 | conf->working_disks); |
| 207 | for (i = 0; i < conf->raid_disks; i++) |
| 208 | seq_printf (seq, "%s", |
| 209 | conf->multipaths[i].rdev && |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 210 | test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | seq_printf (seq, "]"); |
| 212 | } |
| 213 | |
| 214 | static int multipath_issue_flush(request_queue_t *q, struct gendisk *disk, |
| 215 | sector_t *error_sector) |
| 216 | { |
| 217 | mddev_t *mddev = q->queuedata; |
| 218 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 219 | int i, ret = 0; |
| 220 | |
| 221 | rcu_read_lock(); |
| 222 | for (i=0; i<mddev->raid_disks && ret == 0; i++) { |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 223 | mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev); |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 224 | if (rdev && !test_bit(Faulty, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | struct block_device *bdev = rdev->bdev; |
| 226 | request_queue_t *r_queue = bdev_get_queue(bdev); |
| 227 | |
| 228 | if (!r_queue->issue_flush_fn) |
| 229 | ret = -EOPNOTSUPP; |
| 230 | else { |
| 231 | atomic_inc(&rdev->nr_pending); |
| 232 | rcu_read_unlock(); |
| 233 | ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, |
| 234 | error_sector); |
| 235 | rdev_dec_pending(rdev, mddev); |
| 236 | rcu_read_lock(); |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | rcu_read_unlock(); |
| 241 | return ret; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * Careful, this can execute in IRQ contexts as well! |
| 246 | */ |
| 247 | static void multipath_error (mddev_t *mddev, mdk_rdev_t *rdev) |
| 248 | { |
| 249 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 250 | |
| 251 | if (conf->working_disks <= 1) { |
| 252 | /* |
| 253 | * Uh oh, we can do nothing if this is our last path, but |
| 254 | * first check if this is a queued request for a device |
| 255 | * which has just failed. |
| 256 | */ |
| 257 | printk(KERN_ALERT |
| 258 | "multipath: only one IO path left and IO error.\n"); |
| 259 | /* leave it active... it's all we have */ |
| 260 | } else { |
| 261 | /* |
| 262 | * Mark disk as unusable |
| 263 | */ |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 264 | if (!test_bit(Faulty, &rdev->flags)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | char b[BDEVNAME_SIZE]; |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 266 | clear_bit(In_sync, &rdev->flags); |
| 267 | set_bit(Faulty, &rdev->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | mddev->sb_dirty = 1; |
| 269 | conf->working_disks--; |
| 270 | printk(KERN_ALERT "multipath: IO failure on %s," |
| 271 | " disabling IO path. \n Operation continuing" |
| 272 | " on %d IO paths.\n", |
| 273 | bdevname (rdev->bdev,b), |
| 274 | conf->working_disks); |
| 275 | } |
| 276 | } |
| 277 | } |
| 278 | |
| 279 | static void print_multipath_conf (multipath_conf_t *conf) |
| 280 | { |
| 281 | int i; |
| 282 | struct multipath_info *tmp; |
| 283 | |
| 284 | printk("MULTIPATH conf printout:\n"); |
| 285 | if (!conf) { |
| 286 | printk("(conf==NULL)\n"); |
| 287 | return; |
| 288 | } |
| 289 | printk(" --- wd:%d rd:%d\n", conf->working_disks, |
| 290 | conf->raid_disks); |
| 291 | |
| 292 | for (i = 0; i < conf->raid_disks; i++) { |
| 293 | char b[BDEVNAME_SIZE]; |
| 294 | tmp = conf->multipaths + i; |
| 295 | if (tmp->rdev) |
| 296 | printk(" disk%d, o:%d, dev:%s\n", |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 297 | i,!test_bit(Faulty, &tmp->rdev->flags), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | bdevname(tmp->rdev->bdev,b)); |
| 299 | } |
| 300 | } |
| 301 | |
| 302 | |
| 303 | static int multipath_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) |
| 304 | { |
| 305 | multipath_conf_t *conf = mddev->private; |
| 306 | int found = 0; |
| 307 | int path; |
| 308 | struct multipath_info *p; |
| 309 | |
| 310 | print_multipath_conf(conf); |
| 311 | |
| 312 | for (path=0; path<mddev->raid_disks; path++) |
| 313 | if ((p=conf->multipaths+path)->rdev == NULL) { |
| 314 | blk_queue_stack_limits(mddev->queue, |
| 315 | rdev->bdev->bd_disk->queue); |
| 316 | |
| 317 | /* as we don't honour merge_bvec_fn, we must never risk |
| 318 | * violating it, so limit ->max_sector to one PAGE, as |
| 319 | * a one page request is never in violation. |
| 320 | * (Note: it is very unlikely that a device with |
| 321 | * merge_bvec_fn will be involved in multipath.) |
| 322 | */ |
| 323 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && |
| 324 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) |
| 325 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); |
| 326 | |
| 327 | conf->working_disks++; |
| 328 | rdev->raid_disk = path; |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 329 | set_bit(In_sync, &rdev->flags); |
Suzanne Wood | d6065f7 | 2005-11-08 21:39:27 -0800 | [diff] [blame] | 330 | rcu_assign_pointer(p->rdev, rdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | found = 1; |
| 332 | } |
| 333 | |
| 334 | print_multipath_conf(conf); |
| 335 | return found; |
| 336 | } |
| 337 | |
| 338 | static int multipath_remove_disk(mddev_t *mddev, int number) |
| 339 | { |
| 340 | multipath_conf_t *conf = mddev->private; |
| 341 | int err = 0; |
| 342 | mdk_rdev_t *rdev; |
| 343 | struct multipath_info *p = conf->multipaths + number; |
| 344 | |
| 345 | print_multipath_conf(conf); |
| 346 | |
| 347 | rdev = p->rdev; |
| 348 | if (rdev) { |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 349 | if (test_bit(In_sync, &rdev->flags) || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | atomic_read(&rdev->nr_pending)) { |
| 351 | printk(KERN_ERR "hot-remove-disk, slot %d is identified" " but is still operational!\n", number); |
| 352 | err = -EBUSY; |
| 353 | goto abort; |
| 354 | } |
| 355 | p->rdev = NULL; |
Paul E. McKenney | fbd568a3e | 2005-05-01 08:59:04 -0700 | [diff] [blame] | 356 | synchronize_rcu(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | if (atomic_read(&rdev->nr_pending)) { |
| 358 | /* lost the race, try later */ |
| 359 | err = -EBUSY; |
| 360 | p->rdev = rdev; |
| 361 | } |
| 362 | } |
| 363 | abort: |
| 364 | |
| 365 | print_multipath_conf(conf); |
| 366 | return err; |
| 367 | } |
| 368 | |
| 369 | |
| 370 | |
| 371 | /* |
| 372 | * This is a kernel thread which: |
| 373 | * |
| 374 | * 1. Retries failed read operations on working multipaths. |
| 375 | * 2. Updates the raid superblock when problems encounter. |
| 376 | * 3. Performs writes following reads for array syncronising. |
| 377 | */ |
| 378 | |
| 379 | static void multipathd (mddev_t *mddev) |
| 380 | { |
| 381 | struct multipath_bh *mp_bh; |
| 382 | struct bio *bio; |
| 383 | unsigned long flags; |
| 384 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 385 | struct list_head *head = &conf->retry_list; |
| 386 | |
| 387 | md_check_recovery(mddev); |
| 388 | for (;;) { |
| 389 | char b[BDEVNAME_SIZE]; |
| 390 | spin_lock_irqsave(&conf->device_lock, flags); |
| 391 | if (list_empty(head)) |
| 392 | break; |
| 393 | mp_bh = list_entry(head->prev, struct multipath_bh, retry_list); |
| 394 | list_del(head->prev); |
| 395 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 396 | |
| 397 | bio = &mp_bh->bio; |
| 398 | bio->bi_sector = mp_bh->master_bio->bi_sector; |
| 399 | |
| 400 | if ((mp_bh->path = multipath_map (conf))<0) { |
| 401 | printk(KERN_ALERT "multipath: %s: unrecoverable IO read" |
| 402 | " error for block %llu\n", |
| 403 | bdevname(bio->bi_bdev,b), |
| 404 | (unsigned long long)bio->bi_sector); |
| 405 | multipath_end_bh_io(mp_bh, -EIO); |
| 406 | } else { |
| 407 | printk(KERN_ERR "multipath: %s: redirecting sector %llu" |
| 408 | " to another IO path\n", |
| 409 | bdevname(bio->bi_bdev,b), |
| 410 | (unsigned long long)bio->bi_sector); |
| 411 | *bio = *(mp_bh->master_bio); |
| 412 | bio->bi_sector += conf->multipaths[mp_bh->path].rdev->data_offset; |
| 413 | bio->bi_bdev = conf->multipaths[mp_bh->path].rdev->bdev; |
| 414 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); |
| 415 | bio->bi_end_io = multipath_end_request; |
| 416 | bio->bi_private = mp_bh; |
| 417 | generic_make_request(bio); |
| 418 | } |
| 419 | } |
| 420 | spin_unlock_irqrestore(&conf->device_lock, flags); |
| 421 | } |
| 422 | |
| 423 | static int multipath_run (mddev_t *mddev) |
| 424 | { |
| 425 | multipath_conf_t *conf; |
| 426 | int disk_idx; |
| 427 | struct multipath_info *disk; |
| 428 | mdk_rdev_t *rdev; |
| 429 | struct list_head *tmp; |
| 430 | |
| 431 | if (mddev->level != LEVEL_MULTIPATH) { |
| 432 | printk("multipath: %s: raid level not set to multipath IO (%d)\n", |
| 433 | mdname(mddev), mddev->level); |
| 434 | goto out; |
| 435 | } |
| 436 | /* |
| 437 | * copy the already verified devices into our private MULTIPATH |
| 438 | * bookkeeping area. [whatever we allocate in multipath_run(), |
| 439 | * should be freed in multipath_stop()] |
| 440 | */ |
| 441 | |
NeilBrown | 9ffae0c | 2006-01-06 00:20:32 -0800 | [diff] [blame] | 442 | conf = kzalloc(sizeof(multipath_conf_t), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | mddev->private = conf; |
| 444 | if (!conf) { |
| 445 | printk(KERN_ERR |
| 446 | "multipath: couldn't allocate memory for %s\n", |
| 447 | mdname(mddev)); |
| 448 | goto out; |
| 449 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | |
NeilBrown | 9ffae0c | 2006-01-06 00:20:32 -0800 | [diff] [blame] | 451 | conf->multipaths = kzalloc(sizeof(struct multipath_info)*mddev->raid_disks, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | GFP_KERNEL); |
| 453 | if (!conf->multipaths) { |
| 454 | printk(KERN_ERR |
| 455 | "multipath: couldn't allocate memory for %s\n", |
| 456 | mdname(mddev)); |
| 457 | goto out_free_conf; |
| 458 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | conf->working_disks = 0; |
| 461 | ITERATE_RDEV(mddev,rdev,tmp) { |
| 462 | disk_idx = rdev->raid_disk; |
| 463 | if (disk_idx < 0 || |
| 464 | disk_idx >= mddev->raid_disks) |
| 465 | continue; |
| 466 | |
| 467 | disk = conf->multipaths + disk_idx; |
| 468 | disk->rdev = rdev; |
| 469 | |
| 470 | blk_queue_stack_limits(mddev->queue, |
| 471 | rdev->bdev->bd_disk->queue); |
| 472 | /* as we don't honour merge_bvec_fn, we must never risk |
| 473 | * violating it, not that we ever expect a device with |
| 474 | * a merge_bvec_fn to be involved in multipath */ |
| 475 | if (rdev->bdev->bd_disk->queue->merge_bvec_fn && |
| 476 | mddev->queue->max_sectors > (PAGE_SIZE>>9)) |
| 477 | blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); |
| 478 | |
NeilBrown | b2d444d | 2005-11-08 21:39:31 -0800 | [diff] [blame] | 479 | if (!test_bit(Faulty, &rdev->flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | conf->working_disks++; |
| 481 | } |
| 482 | |
| 483 | conf->raid_disks = mddev->raid_disks; |
| 484 | mddev->sb_dirty = 1; |
| 485 | conf->mddev = mddev; |
| 486 | spin_lock_init(&conf->device_lock); |
| 487 | INIT_LIST_HEAD(&conf->retry_list); |
| 488 | |
| 489 | if (!conf->working_disks) { |
| 490 | printk(KERN_ERR "multipath: no operational IO paths for %s\n", |
| 491 | mdname(mddev)); |
| 492 | goto out_free_conf; |
| 493 | } |
| 494 | mddev->degraded = conf->raid_disks = conf->working_disks; |
| 495 | |
| 496 | conf->pool = mempool_create(NR_RESERVED_BUFS, |
| 497 | mp_pool_alloc, mp_pool_free, |
| 498 | NULL); |
| 499 | if (conf->pool == NULL) { |
| 500 | printk(KERN_ERR |
| 501 | "multipath: couldn't allocate memory for %s\n", |
| 502 | mdname(mddev)); |
| 503 | goto out_free_conf; |
| 504 | } |
| 505 | |
| 506 | { |
| 507 | mddev->thread = md_register_thread(multipathd, mddev, "%s_multipath"); |
| 508 | if (!mddev->thread) { |
| 509 | printk(KERN_ERR "multipath: couldn't allocate thread" |
| 510 | " for %s\n", mdname(mddev)); |
| 511 | goto out_free_conf; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | printk(KERN_INFO |
| 516 | "multipath: array %s active with %d out of %d IO paths\n", |
| 517 | mdname(mddev), conf->working_disks, mddev->raid_disks); |
| 518 | /* |
| 519 | * Ok, everything is just fine now |
| 520 | */ |
| 521 | mddev->array_size = mddev->size; |
NeilBrown | 7a5febe | 2005-05-16 21:53:16 -0700 | [diff] [blame] | 522 | |
| 523 | mddev->queue->unplug_fn = multipath_unplug; |
| 524 | mddev->queue->issue_flush_fn = multipath_issue_flush; |
| 525 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | return 0; |
| 527 | |
| 528 | out_free_conf: |
| 529 | if (conf->pool) |
| 530 | mempool_destroy(conf->pool); |
Jesper Juhl | 990a8ba | 2005-06-21 17:17:30 -0700 | [diff] [blame] | 531 | kfree(conf->multipaths); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | kfree(conf); |
| 533 | mddev->private = NULL; |
| 534 | out: |
| 535 | return -EIO; |
| 536 | } |
| 537 | |
| 538 | |
| 539 | static int multipath_stop (mddev_t *mddev) |
| 540 | { |
| 541 | multipath_conf_t *conf = mddev_to_conf(mddev); |
| 542 | |
| 543 | md_unregister_thread(mddev->thread); |
| 544 | mddev->thread = NULL; |
| 545 | blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
| 546 | mempool_destroy(conf->pool); |
| 547 | kfree(conf->multipaths); |
| 548 | kfree(conf); |
| 549 | mddev->private = NULL; |
| 550 | return 0; |
| 551 | } |
| 552 | |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame^] | 553 | static struct mdk_personality multipath_personality = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | { |
| 555 | .name = "multipath", |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame^] | 556 | .level = LEVEL_MULTIPATH, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | .owner = THIS_MODULE, |
| 558 | .make_request = multipath_make_request, |
| 559 | .run = multipath_run, |
| 560 | .stop = multipath_stop, |
| 561 | .status = multipath_status, |
| 562 | .error_handler = multipath_error, |
| 563 | .hot_add_disk = multipath_add_disk, |
| 564 | .hot_remove_disk= multipath_remove_disk, |
| 565 | }; |
| 566 | |
| 567 | static int __init multipath_init (void) |
| 568 | { |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame^] | 569 | return register_md_personality (&multipath_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 570 | } |
| 571 | |
| 572 | static void __exit multipath_exit (void) |
| 573 | { |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame^] | 574 | unregister_md_personality (&multipath_personality); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | } |
| 576 | |
| 577 | module_init(multipath_init); |
| 578 | module_exit(multipath_exit); |
| 579 | MODULE_LICENSE("GPL"); |
| 580 | MODULE_ALIAS("md-personality-7"); /* MULTIPATH */ |
NeilBrown | 2604b70 | 2006-01-06 00:20:36 -0800 | [diff] [blame^] | 581 | MODULE_ALIAS("md-level--4"); |