Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software Limited. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
586e80e6 MP |
8 | #include <linux/device-mapper.h> |
9 | ||
1da177e4 | 10 | #include "dm-path-selector.h" |
b15546f9 | 11 | #include "dm-uevent.h" |
1da177e4 LT |
12 | |
13 | #include <linux/ctype.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/workqueue.h> | |
cfae5c9b | 21 | #include <scsi/scsi_dh.h> |
1da177e4 LT |
22 | #include <asm/atomic.h> |
23 | ||
72d94861 | 24 | #define DM_MSG_PREFIX "multipath" |
1da177e4 LT |
25 | #define MESG_STR(x) x, sizeof(x) |
26 | ||
27 | /* Path properties */ | |
28 | struct pgpath { | |
29 | struct list_head list; | |
30 | ||
31 | struct priority_group *pg; /* Owning PG */ | |
6680073d | 32 | unsigned is_active; /* Path status */ |
1da177e4 LT |
33 | unsigned fail_count; /* Cumulative failure count */ |
34 | ||
c922d5f7 | 35 | struct dm_path path; |
224cb3e9 | 36 | struct work_struct deactivate_path; |
e54f77dd | 37 | struct work_struct activate_path; |
1da177e4 LT |
38 | }; |
39 | ||
40 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
41 | ||
42 | /* | |
43 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
44 | * Each has a path selector which controls which path gets used. | |
45 | */ | |
46 | struct priority_group { | |
47 | struct list_head list; | |
48 | ||
49 | struct multipath *m; /* Owning multipath instance */ | |
50 | struct path_selector ps; | |
51 | ||
52 | unsigned pg_num; /* Reference number */ | |
53 | unsigned bypassed; /* Temporarily bypass this PG? */ | |
54 | ||
55 | unsigned nr_pgpaths; /* Number of paths in PG */ | |
56 | struct list_head pgpaths; | |
57 | }; | |
58 | ||
59 | /* Multipath context */ | |
60 | struct multipath { | |
61 | struct list_head list; | |
62 | struct dm_target *ti; | |
63 | ||
64 | spinlock_t lock; | |
65 | ||
cfae5c9b | 66 | const char *hw_handler_name; |
2bfd2e13 | 67 | char *hw_handler_params; |
1da177e4 LT |
68 | unsigned nr_priority_groups; |
69 | struct list_head priority_groups; | |
70 | unsigned pg_init_required; /* pg_init needs calling? */ | |
c3cd4f6b | 71 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
1da177e4 LT |
72 | |
73 | unsigned nr_valid_paths; /* Total number of usable paths */ | |
74 | struct pgpath *current_pgpath; | |
75 | struct priority_group *current_pg; | |
76 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
77 | unsigned repeat_count; /* I/Os left before calling PS again */ | |
78 | ||
79 | unsigned queue_io; /* Must we queue all I/O? */ | |
80 | unsigned queue_if_no_path; /* Queue I/O if last path fails? */ | |
436d4108 | 81 | unsigned saved_queue_if_no_path;/* Saved state during suspension */ |
c9e45581 DW |
82 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
83 | unsigned pg_init_count; /* Number of times pg_init called */ | |
1da177e4 LT |
84 | |
85 | struct work_struct process_queued_ios; | |
f40c67f0 | 86 | struct list_head queued_ios; |
1da177e4 LT |
87 | unsigned queue_size; |
88 | ||
89 | struct work_struct trigger_event; | |
90 | ||
91 | /* | |
028867ac | 92 | * We must use a mempool of dm_mpath_io structs so that we |
1da177e4 LT |
93 | * can resubmit bios on error. |
94 | */ | |
95 | mempool_t *mpio_pool; | |
6380f26f MA |
96 | |
97 | struct mutex work_mutex; | |
1da177e4 LT |
98 | }; |
99 | ||
100 | /* | |
101 | * Context information attached to each bio we process. | |
102 | */ | |
028867ac | 103 | struct dm_mpath_io { |
1da177e4 | 104 | struct pgpath *pgpath; |
02ab823f | 105 | size_t nr_bytes; |
1da177e4 LT |
106 | }; |
107 | ||
108 | typedef int (*action_fn) (struct pgpath *pgpath); | |
109 | ||
110 | #define MIN_IOS 256 /* Mempool size */ | |
111 | ||
e18b890b | 112 | static struct kmem_cache *_mpio_cache; |
1da177e4 | 113 | |
bab7cfc7 | 114 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 DH |
115 | static void process_queued_ios(struct work_struct *work); |
116 | static void trigger_event(struct work_struct *work); | |
bab7cfc7 | 117 | static void activate_path(struct work_struct *work); |
224cb3e9 | 118 | static void deactivate_path(struct work_struct *work); |
1da177e4 LT |
119 | |
120 | ||
121 | /*----------------------------------------------- | |
122 | * Allocation routines | |
123 | *-----------------------------------------------*/ | |
124 | ||
125 | static struct pgpath *alloc_pgpath(void) | |
126 | { | |
e69fae56 | 127 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 128 | |
224cb3e9 | 129 | if (pgpath) { |
6680073d | 130 | pgpath->is_active = 1; |
224cb3e9 | 131 | INIT_WORK(&pgpath->deactivate_path, deactivate_path); |
e54f77dd | 132 | INIT_WORK(&pgpath->activate_path, activate_path); |
224cb3e9 | 133 | } |
1da177e4 LT |
134 | |
135 | return pgpath; | |
136 | } | |
137 | ||
028867ac | 138 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
139 | { |
140 | kfree(pgpath); | |
141 | } | |
142 | ||
224cb3e9 MA |
143 | static void deactivate_path(struct work_struct *work) |
144 | { | |
145 | struct pgpath *pgpath = | |
146 | container_of(work, struct pgpath, deactivate_path); | |
147 | ||
148 | blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue); | |
149 | } | |
150 | ||
1da177e4 LT |
151 | static struct priority_group *alloc_priority_group(void) |
152 | { | |
153 | struct priority_group *pg; | |
154 | ||
e69fae56 | 155 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 156 | |
e69fae56 MM |
157 | if (pg) |
158 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
159 | |
160 | return pg; | |
161 | } | |
162 | ||
163 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
164 | { | |
165 | struct pgpath *pgpath, *tmp; | |
ae11b1b3 | 166 | struct multipath *m = ti->private; |
1da177e4 LT |
167 | |
168 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
169 | list_del(&pgpath->list); | |
ae11b1b3 HR |
170 | if (m->hw_handler_name) |
171 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); | |
1da177e4 LT |
172 | dm_put_device(ti, pgpath->path.dev); |
173 | free_pgpath(pgpath); | |
174 | } | |
175 | } | |
176 | ||
177 | static void free_priority_group(struct priority_group *pg, | |
178 | struct dm_target *ti) | |
179 | { | |
180 | struct path_selector *ps = &pg->ps; | |
181 | ||
182 | if (ps->type) { | |
183 | ps->type->destroy(ps); | |
184 | dm_put_path_selector(ps->type); | |
185 | } | |
186 | ||
187 | free_pgpaths(&pg->pgpaths, ti); | |
188 | kfree(pg); | |
189 | } | |
190 | ||
28f16c20 | 191 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
192 | { |
193 | struct multipath *m; | |
194 | ||
e69fae56 | 195 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 196 | if (m) { |
1da177e4 | 197 | INIT_LIST_HEAD(&m->priority_groups); |
f40c67f0 | 198 | INIT_LIST_HEAD(&m->queued_ios); |
1da177e4 LT |
199 | spin_lock_init(&m->lock); |
200 | m->queue_io = 1; | |
c4028958 DH |
201 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
202 | INIT_WORK(&m->trigger_event, trigger_event); | |
6380f26f | 203 | mutex_init(&m->work_mutex); |
93d2341c | 204 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
1da177e4 LT |
205 | if (!m->mpio_pool) { |
206 | kfree(m); | |
207 | return NULL; | |
208 | } | |
28f16c20 MM |
209 | m->ti = ti; |
210 | ti->private = m; | |
1da177e4 LT |
211 | } |
212 | ||
213 | return m; | |
214 | } | |
215 | ||
216 | static void free_multipath(struct multipath *m) | |
217 | { | |
218 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
219 | |
220 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
221 | list_del(&pg->list); | |
222 | free_priority_group(pg, m->ti); | |
223 | } | |
224 | ||
cfae5c9b | 225 | kfree(m->hw_handler_name); |
2bfd2e13 | 226 | kfree(m->hw_handler_params); |
1da177e4 LT |
227 | mempool_destroy(m->mpio_pool); |
228 | kfree(m); | |
229 | } | |
230 | ||
231 | ||
232 | /*----------------------------------------------- | |
233 | * Path selection | |
234 | *-----------------------------------------------*/ | |
235 | ||
236 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) | |
237 | { | |
1da177e4 LT |
238 | m->current_pg = pgpath->pg; |
239 | ||
240 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 241 | if (m->hw_handler_name) { |
1da177e4 LT |
242 | m->pg_init_required = 1; |
243 | m->queue_io = 1; | |
244 | } else { | |
245 | m->pg_init_required = 0; | |
246 | m->queue_io = 0; | |
247 | } | |
c9e45581 DW |
248 | |
249 | m->pg_init_count = 0; | |
1da177e4 LT |
250 | } |
251 | ||
02ab823f KU |
252 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
253 | size_t nr_bytes) | |
1da177e4 | 254 | { |
c922d5f7 | 255 | struct dm_path *path; |
1da177e4 | 256 | |
02ab823f | 257 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes); |
1da177e4 LT |
258 | if (!path) |
259 | return -ENXIO; | |
260 | ||
261 | m->current_pgpath = path_to_pgpath(path); | |
262 | ||
263 | if (m->current_pg != pg) | |
264 | __switch_pg(m, m->current_pgpath); | |
265 | ||
266 | return 0; | |
267 | } | |
268 | ||
02ab823f | 269 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 LT |
270 | { |
271 | struct priority_group *pg; | |
272 | unsigned bypassed = 1; | |
273 | ||
274 | if (!m->nr_valid_paths) | |
275 | goto failed; | |
276 | ||
277 | /* Were we instructed to switch PG? */ | |
278 | if (m->next_pg) { | |
279 | pg = m->next_pg; | |
280 | m->next_pg = NULL; | |
02ab823f | 281 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
282 | return; |
283 | } | |
284 | ||
285 | /* Don't change PG until it has no remaining paths */ | |
02ab823f | 286 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes)) |
1da177e4 LT |
287 | return; |
288 | ||
289 | /* | |
290 | * Loop through priority groups until we find a valid path. | |
291 | * First time we skip PGs marked 'bypassed'. | |
292 | * Second time we only try the ones we skipped. | |
293 | */ | |
294 | do { | |
295 | list_for_each_entry(pg, &m->priority_groups, list) { | |
296 | if (pg->bypassed == bypassed) | |
297 | continue; | |
02ab823f | 298 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
299 | return; |
300 | } | |
301 | } while (bypassed--); | |
302 | ||
303 | failed: | |
304 | m->current_pgpath = NULL; | |
305 | m->current_pg = NULL; | |
306 | } | |
307 | ||
45e15720 KU |
308 | /* |
309 | * Check whether bios must be queued in the device-mapper core rather | |
310 | * than here in the target. | |
311 | * | |
312 | * m->lock must be held on entry. | |
313 | * | |
314 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
315 | * same value then we are not between multipath_presuspend() | |
316 | * and multipath_resume() calls and we have no need to check | |
317 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
318 | */ | |
319 | static int __must_push_back(struct multipath *m) | |
320 | { | |
321 | return (m->queue_if_no_path != m->saved_queue_if_no_path && | |
322 | dm_noflush_suspending(m->ti)); | |
323 | } | |
324 | ||
f40c67f0 | 325 | static int map_io(struct multipath *m, struct request *clone, |
028867ac | 326 | struct dm_mpath_io *mpio, unsigned was_queued) |
1da177e4 | 327 | { |
d2a7ad29 | 328 | int r = DM_MAPIO_REMAPPED; |
f40c67f0 | 329 | size_t nr_bytes = blk_rq_bytes(clone); |
1da177e4 LT |
330 | unsigned long flags; |
331 | struct pgpath *pgpath; | |
f40c67f0 | 332 | struct block_device *bdev; |
1da177e4 LT |
333 | |
334 | spin_lock_irqsave(&m->lock, flags); | |
335 | ||
336 | /* Do we need to select a new pgpath? */ | |
337 | if (!m->current_pgpath || | |
338 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
02ab823f | 339 | __choose_pgpath(m, nr_bytes); |
1da177e4 LT |
340 | |
341 | pgpath = m->current_pgpath; | |
342 | ||
343 | if (was_queued) | |
344 | m->queue_size--; | |
345 | ||
346 | if ((pgpath && m->queue_io) || | |
436d4108 | 347 | (!pgpath && m->queue_if_no_path)) { |
1da177e4 | 348 | /* Queue for the daemon to resubmit */ |
f40c67f0 | 349 | list_add_tail(&clone->queuelist, &m->queued_ios); |
1da177e4 | 350 | m->queue_size++; |
c3cd4f6b AK |
351 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
352 | !m->queue_io) | |
c557308e | 353 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 354 | pgpath = NULL; |
d2a7ad29 | 355 | r = DM_MAPIO_SUBMITTED; |
f40c67f0 KU |
356 | } else if (pgpath) { |
357 | bdev = pgpath->path.dev->bdev; | |
358 | clone->q = bdev_get_queue(bdev); | |
359 | clone->rq_disk = bdev->bd_disk; | |
360 | } else if (__must_push_back(m)) | |
45e15720 KU |
361 | r = DM_MAPIO_REQUEUE; |
362 | else | |
363 | r = -EIO; /* Failed */ | |
1da177e4 LT |
364 | |
365 | mpio->pgpath = pgpath; | |
02ab823f KU |
366 | mpio->nr_bytes = nr_bytes; |
367 | ||
368 | if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io) | |
369 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path, | |
370 | nr_bytes); | |
1da177e4 LT |
371 | |
372 | spin_unlock_irqrestore(&m->lock, flags); | |
373 | ||
374 | return r; | |
375 | } | |
376 | ||
377 | /* | |
378 | * If we run out of usable paths, should we queue I/O or error it? | |
379 | */ | |
485ef69e AK |
380 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
381 | unsigned save_old_value) | |
1da177e4 LT |
382 | { |
383 | unsigned long flags; | |
384 | ||
385 | spin_lock_irqsave(&m->lock, flags); | |
386 | ||
485ef69e AK |
387 | if (save_old_value) |
388 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
389 | else | |
390 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 391 | m->queue_if_no_path = queue_if_no_path; |
c3cd4f6b | 392 | if (!m->queue_if_no_path && m->queue_size) |
c557308e | 393 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
394 | |
395 | spin_unlock_irqrestore(&m->lock, flags); | |
396 | ||
397 | return 0; | |
398 | } | |
399 | ||
400 | /*----------------------------------------------------------------- | |
401 | * The multipath daemon is responsible for resubmitting queued ios. | |
402 | *---------------------------------------------------------------*/ | |
403 | ||
404 | static void dispatch_queued_ios(struct multipath *m) | |
405 | { | |
406 | int r; | |
407 | unsigned long flags; | |
028867ac | 408 | struct dm_mpath_io *mpio; |
1da177e4 | 409 | union map_info *info; |
f40c67f0 KU |
410 | struct request *clone, *n; |
411 | LIST_HEAD(cl); | |
1da177e4 LT |
412 | |
413 | spin_lock_irqsave(&m->lock, flags); | |
f40c67f0 | 414 | list_splice_init(&m->queued_ios, &cl); |
1da177e4 LT |
415 | spin_unlock_irqrestore(&m->lock, flags); |
416 | ||
f40c67f0 KU |
417 | list_for_each_entry_safe(clone, n, &cl, queuelist) { |
418 | list_del_init(&clone->queuelist); | |
1da177e4 | 419 | |
f40c67f0 | 420 | info = dm_get_rq_mapinfo(clone); |
1da177e4 LT |
421 | mpio = info->ptr; |
422 | ||
f40c67f0 KU |
423 | r = map_io(m, clone, mpio, 1); |
424 | if (r < 0) { | |
425 | mempool_free(mpio, m->mpio_pool); | |
426 | dm_kill_unmapped_request(clone, r); | |
427 | } else if (r == DM_MAPIO_REMAPPED) | |
428 | dm_dispatch_request(clone); | |
429 | else if (r == DM_MAPIO_REQUEUE) { | |
430 | mempool_free(mpio, m->mpio_pool); | |
431 | dm_requeue_unmapped_request(clone); | |
432 | } | |
1da177e4 LT |
433 | } |
434 | } | |
435 | ||
c4028958 | 436 | static void process_queued_ios(struct work_struct *work) |
1da177e4 | 437 | { |
c4028958 DH |
438 | struct multipath *m = |
439 | container_of(work, struct multipath, process_queued_ios); | |
e54f77dd CS |
440 | struct pgpath *pgpath = NULL, *tmp; |
441 | unsigned must_queue = 1; | |
1da177e4 LT |
442 | unsigned long flags; |
443 | ||
444 | spin_lock_irqsave(&m->lock, flags); | |
445 | ||
c3cd4f6b AK |
446 | if (!m->queue_size) |
447 | goto out; | |
448 | ||
1da177e4 | 449 | if (!m->current_pgpath) |
02ab823f | 450 | __choose_pgpath(m, 0); |
1da177e4 LT |
451 | |
452 | pgpath = m->current_pgpath; | |
453 | ||
c3cd4f6b AK |
454 | if ((pgpath && !m->queue_io) || |
455 | (!pgpath && !m->queue_if_no_path)) | |
456 | must_queue = 0; | |
1da177e4 | 457 | |
b81aa1c7 | 458 | if (m->pg_init_required && !m->pg_init_in_progress && pgpath) { |
c9e45581 | 459 | m->pg_init_count++; |
1da177e4 | 460 | m->pg_init_required = 0; |
e54f77dd | 461 | list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) { |
f7b934c8 MB |
462 | /* Skip failed paths */ |
463 | if (!tmp->is_active) | |
464 | continue; | |
e54f77dd CS |
465 | if (queue_work(kmpath_handlerd, &tmp->activate_path)) |
466 | m->pg_init_in_progress++; | |
467 | } | |
c3cd4f6b | 468 | } |
c3cd4f6b | 469 | out: |
1da177e4 | 470 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
471 | if (!must_queue) |
472 | dispatch_queued_ios(m); | |
473 | } | |
474 | ||
475 | /* | |
476 | * An event is triggered whenever a path is taken out of use. | |
477 | * Includes path failure and PG bypass. | |
478 | */ | |
c4028958 | 479 | static void trigger_event(struct work_struct *work) |
1da177e4 | 480 | { |
c4028958 DH |
481 | struct multipath *m = |
482 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
483 | |
484 | dm_table_event(m->ti->table); | |
485 | } | |
486 | ||
487 | /*----------------------------------------------------------------- | |
488 | * Constructor/argument parsing: | |
489 | * <#multipath feature args> [<arg>]* | |
490 | * <#hw_handler args> [hw_handler [<arg>]*] | |
491 | * <#priority groups> | |
492 | * <initial priority group> | |
493 | * [<selector> <#selector args> [<arg>]* | |
494 | * <#paths> <#per-path selector args> | |
495 | * [<path> [<arg>]* ]+ ]+ | |
496 | *---------------------------------------------------------------*/ | |
497 | struct param { | |
498 | unsigned min; | |
499 | unsigned max; | |
500 | char *error; | |
501 | }; | |
502 | ||
1da177e4 LT |
503 | static int read_param(struct param *param, char *str, unsigned *v, char **error) |
504 | { | |
505 | if (!str || | |
506 | (sscanf(str, "%u", v) != 1) || | |
507 | (*v < param->min) || | |
508 | (*v > param->max)) { | |
509 | *error = param->error; | |
510 | return -EINVAL; | |
511 | } | |
512 | ||
513 | return 0; | |
514 | } | |
515 | ||
516 | struct arg_set { | |
517 | unsigned argc; | |
518 | char **argv; | |
519 | }; | |
520 | ||
521 | static char *shift(struct arg_set *as) | |
522 | { | |
523 | char *r; | |
524 | ||
525 | if (as->argc) { | |
526 | as->argc--; | |
527 | r = *as->argv; | |
528 | as->argv++; | |
529 | return r; | |
530 | } | |
531 | ||
532 | return NULL; | |
533 | } | |
534 | ||
535 | static void consume(struct arg_set *as, unsigned n) | |
536 | { | |
537 | BUG_ON (as->argc < n); | |
538 | as->argc -= n; | |
539 | as->argv += n; | |
540 | } | |
541 | ||
542 | static int parse_path_selector(struct arg_set *as, struct priority_group *pg, | |
543 | struct dm_target *ti) | |
544 | { | |
545 | int r; | |
546 | struct path_selector_type *pst; | |
547 | unsigned ps_argc; | |
548 | ||
549 | static struct param _params[] = { | |
72d94861 | 550 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
551 | }; |
552 | ||
553 | pst = dm_get_path_selector(shift(as)); | |
554 | if (!pst) { | |
72d94861 | 555 | ti->error = "unknown path selector type"; |
1da177e4 LT |
556 | return -EINVAL; |
557 | } | |
558 | ||
559 | r = read_param(_params, shift(as), &ps_argc, &ti->error); | |
371b2e34 MP |
560 | if (r) { |
561 | dm_put_path_selector(pst); | |
1da177e4 | 562 | return -EINVAL; |
371b2e34 | 563 | } |
1da177e4 | 564 | |
0e0497c0 MP |
565 | if (ps_argc > as->argc) { |
566 | dm_put_path_selector(pst); | |
567 | ti->error = "not enough arguments for path selector"; | |
568 | return -EINVAL; | |
569 | } | |
570 | ||
1da177e4 LT |
571 | r = pst->create(&pg->ps, ps_argc, as->argv); |
572 | if (r) { | |
573 | dm_put_path_selector(pst); | |
72d94861 | 574 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
575 | return r; |
576 | } | |
577 | ||
578 | pg->ps.type = pst; | |
579 | consume(as, ps_argc); | |
580 | ||
581 | return 0; | |
582 | } | |
583 | ||
584 | static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, | |
585 | struct dm_target *ti) | |
586 | { | |
587 | int r; | |
588 | struct pgpath *p; | |
ae11b1b3 | 589 | struct multipath *m = ti->private; |
1da177e4 LT |
590 | |
591 | /* we need at least a path arg */ | |
592 | if (as->argc < 1) { | |
72d94861 | 593 | ti->error = "no device given"; |
01460f35 | 594 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
595 | } |
596 | ||
597 | p = alloc_pgpath(); | |
598 | if (!p) | |
01460f35 | 599 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
600 | |
601 | r = dm_get_device(ti, shift(as), ti->begin, ti->len, | |
602 | dm_table_get_mode(ti->table), &p->path.dev); | |
603 | if (r) { | |
72d94861 | 604 | ti->error = "error getting device"; |
1da177e4 LT |
605 | goto bad; |
606 | } | |
607 | ||
ae11b1b3 | 608 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
609 | struct request_queue *q = bdev_get_queue(p->path.dev->bdev); |
610 | ||
611 | r = scsi_dh_attach(q, m->hw_handler_name); | |
612 | if (r == -EBUSY) { | |
613 | /* | |
614 | * Already attached to different hw_handler, | |
615 | * try to reattach with correct one. | |
616 | */ | |
617 | scsi_dh_detach(q); | |
618 | r = scsi_dh_attach(q, m->hw_handler_name); | |
619 | } | |
620 | ||
ae11b1b3 | 621 | if (r < 0) { |
a0cf7ea9 | 622 | ti->error = "error attaching hardware handler"; |
ae11b1b3 HR |
623 | dm_put_device(ti, p->path.dev); |
624 | goto bad; | |
625 | } | |
2bfd2e13 CS |
626 | |
627 | if (m->hw_handler_params) { | |
628 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
629 | if (r < 0) { | |
630 | ti->error = "unable to set hardware " | |
631 | "handler parameters"; | |
632 | scsi_dh_detach(q); | |
633 | dm_put_device(ti, p->path.dev); | |
634 | goto bad; | |
635 | } | |
636 | } | |
ae11b1b3 HR |
637 | } |
638 | ||
1da177e4 LT |
639 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
640 | if (r) { | |
641 | dm_put_device(ti, p->path.dev); | |
642 | goto bad; | |
643 | } | |
644 | ||
645 | return p; | |
646 | ||
647 | bad: | |
648 | free_pgpath(p); | |
01460f35 | 649 | return ERR_PTR(r); |
1da177e4 LT |
650 | } |
651 | ||
652 | static struct priority_group *parse_priority_group(struct arg_set *as, | |
28f16c20 | 653 | struct multipath *m) |
1da177e4 LT |
654 | { |
655 | static struct param _params[] = { | |
72d94861 AK |
656 | {1, 1024, "invalid number of paths"}, |
657 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
658 | }; |
659 | ||
660 | int r; | |
661 | unsigned i, nr_selector_args, nr_params; | |
662 | struct priority_group *pg; | |
28f16c20 | 663 | struct dm_target *ti = m->ti; |
1da177e4 LT |
664 | |
665 | if (as->argc < 2) { | |
666 | as->argc = 0; | |
01460f35 BM |
667 | ti->error = "not enough priority group arguments"; |
668 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
669 | } |
670 | ||
671 | pg = alloc_priority_group(); | |
672 | if (!pg) { | |
72d94861 | 673 | ti->error = "couldn't allocate priority group"; |
01460f35 | 674 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
675 | } |
676 | pg->m = m; | |
677 | ||
678 | r = parse_path_selector(as, pg, ti); | |
679 | if (r) | |
680 | goto bad; | |
681 | ||
682 | /* | |
683 | * read the paths | |
684 | */ | |
685 | r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error); | |
686 | if (r) | |
687 | goto bad; | |
688 | ||
689 | r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error); | |
690 | if (r) | |
691 | goto bad; | |
692 | ||
693 | nr_params = 1 + nr_selector_args; | |
694 | for (i = 0; i < pg->nr_pgpaths; i++) { | |
695 | struct pgpath *pgpath; | |
696 | struct arg_set path_args; | |
697 | ||
148acff6 MP |
698 | if (as->argc < nr_params) { |
699 | ti->error = "not enough path parameters"; | |
1da177e4 | 700 | goto bad; |
148acff6 | 701 | } |
1da177e4 LT |
702 | |
703 | path_args.argc = nr_params; | |
704 | path_args.argv = as->argv; | |
705 | ||
706 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
707 | if (IS_ERR(pgpath)) { |
708 | r = PTR_ERR(pgpath); | |
1da177e4 | 709 | goto bad; |
01460f35 | 710 | } |
1da177e4 LT |
711 | |
712 | pgpath->pg = pg; | |
713 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
714 | consume(as, nr_params); | |
715 | } | |
716 | ||
717 | return pg; | |
718 | ||
719 | bad: | |
720 | free_priority_group(pg, ti); | |
01460f35 | 721 | return ERR_PTR(r); |
1da177e4 LT |
722 | } |
723 | ||
28f16c20 | 724 | static int parse_hw_handler(struct arg_set *as, struct multipath *m) |
1da177e4 | 725 | { |
1da177e4 | 726 | unsigned hw_argc; |
2bfd2e13 | 727 | int ret; |
28f16c20 | 728 | struct dm_target *ti = m->ti; |
1da177e4 LT |
729 | |
730 | static struct param _params[] = { | |
72d94861 | 731 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
732 | }; |
733 | ||
cfae5c9b | 734 | if (read_param(_params, shift(as), &hw_argc, &ti->error)) |
1da177e4 LT |
735 | return -EINVAL; |
736 | ||
737 | if (!hw_argc) | |
738 | return 0; | |
739 | ||
e094f4f1 MP |
740 | if (hw_argc > as->argc) { |
741 | ti->error = "not enough arguments for hardware handler"; | |
742 | return -EINVAL; | |
743 | } | |
744 | ||
cfae5c9b CS |
745 | m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL); |
746 | request_module("scsi_dh_%s", m->hw_handler_name); | |
747 | if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { | |
72d94861 | 748 | ti->error = "unknown hardware handler type"; |
2bfd2e13 CS |
749 | ret = -EINVAL; |
750 | goto fail; | |
1da177e4 | 751 | } |
14e98c5c | 752 | |
2bfd2e13 CS |
753 | if (hw_argc > 1) { |
754 | char *p; | |
755 | int i, j, len = 4; | |
756 | ||
757 | for (i = 0; i <= hw_argc - 2; i++) | |
758 | len += strlen(as->argv[i]) + 1; | |
759 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
760 | if (!p) { | |
761 | ti->error = "memory allocation failed"; | |
762 | ret = -ENOMEM; | |
763 | goto fail; | |
764 | } | |
765 | j = sprintf(p, "%d", hw_argc - 1); | |
766 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
767 | j = sprintf(p, "%s", as->argv[i]); | |
768 | } | |
1da177e4 LT |
769 | consume(as, hw_argc - 1); |
770 | ||
771 | return 0; | |
2bfd2e13 CS |
772 | fail: |
773 | kfree(m->hw_handler_name); | |
774 | m->hw_handler_name = NULL; | |
775 | return ret; | |
1da177e4 LT |
776 | } |
777 | ||
28f16c20 | 778 | static int parse_features(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
779 | { |
780 | int r; | |
781 | unsigned argc; | |
28f16c20 | 782 | struct dm_target *ti = m->ti; |
c9e45581 | 783 | const char *param_name; |
1da177e4 LT |
784 | |
785 | static struct param _params[] = { | |
c9e45581 DW |
786 | {0, 3, "invalid number of feature args"}, |
787 | {1, 50, "pg_init_retries must be between 1 and 50"}, | |
1da177e4 LT |
788 | }; |
789 | ||
790 | r = read_param(_params, shift(as), &argc, &ti->error); | |
791 | if (r) | |
792 | return -EINVAL; | |
793 | ||
794 | if (!argc) | |
795 | return 0; | |
796 | ||
c9e45581 DW |
797 | do { |
798 | param_name = shift(as); | |
799 | argc--; | |
800 | ||
801 | if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { | |
802 | r = queue_if_no_path(m, 1, 0); | |
803 | continue; | |
804 | } | |
805 | ||
806 | if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && | |
807 | (argc >= 1)) { | |
808 | r = read_param(_params + 1, shift(as), | |
809 | &m->pg_init_retries, &ti->error); | |
810 | argc--; | |
811 | continue; | |
812 | } | |
813 | ||
1da177e4 | 814 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
815 | r = -EINVAL; |
816 | } while (argc && !r); | |
817 | ||
818 | return r; | |
1da177e4 LT |
819 | } |
820 | ||
821 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
822 | char **argv) | |
823 | { | |
824 | /* target parameters */ | |
825 | static struct param _params[] = { | |
72d94861 AK |
826 | {1, 1024, "invalid number of priority groups"}, |
827 | {1, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
828 | }; |
829 | ||
830 | int r; | |
831 | struct multipath *m; | |
832 | struct arg_set as; | |
833 | unsigned pg_count = 0; | |
834 | unsigned next_pg_num; | |
835 | ||
836 | as.argc = argc; | |
837 | as.argv = argv; | |
838 | ||
28f16c20 | 839 | m = alloc_multipath(ti); |
1da177e4 | 840 | if (!m) { |
72d94861 | 841 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
842 | return -EINVAL; |
843 | } | |
844 | ||
28f16c20 | 845 | r = parse_features(&as, m); |
1da177e4 LT |
846 | if (r) |
847 | goto bad; | |
848 | ||
28f16c20 | 849 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
850 | if (r) |
851 | goto bad; | |
852 | ||
853 | r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error); | |
854 | if (r) | |
855 | goto bad; | |
856 | ||
857 | r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error); | |
858 | if (r) | |
859 | goto bad; | |
860 | ||
861 | /* parse the priority groups */ | |
862 | while (as.argc) { | |
863 | struct priority_group *pg; | |
864 | ||
28f16c20 | 865 | pg = parse_priority_group(&as, m); |
01460f35 BM |
866 | if (IS_ERR(pg)) { |
867 | r = PTR_ERR(pg); | |
1da177e4 LT |
868 | goto bad; |
869 | } | |
870 | ||
871 | m->nr_valid_paths += pg->nr_pgpaths; | |
872 | list_add_tail(&pg->list, &m->priority_groups); | |
873 | pg_count++; | |
874 | pg->pg_num = pg_count; | |
875 | if (!--next_pg_num) | |
876 | m->next_pg = pg; | |
877 | } | |
878 | ||
879 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 880 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
881 | r = -EINVAL; |
882 | goto bad; | |
883 | } | |
884 | ||
8627921f MP |
885 | ti->num_flush_requests = 1; |
886 | ||
1da177e4 LT |
887 | return 0; |
888 | ||
889 | bad: | |
890 | free_multipath(m); | |
891 | return r; | |
892 | } | |
893 | ||
6df400ab | 894 | static void flush_multipath_work(void) |
1da177e4 | 895 | { |
bab7cfc7 | 896 | flush_workqueue(kmpath_handlerd); |
a044d016 | 897 | flush_workqueue(kmultipathd); |
53b351f9 | 898 | flush_scheduled_work(); |
6df400ab KU |
899 | } |
900 | ||
901 | static void multipath_dtr(struct dm_target *ti) | |
902 | { | |
903 | struct multipath *m = ti->private; | |
904 | ||
905 | flush_multipath_work(); | |
1da177e4 LT |
906 | free_multipath(m); |
907 | } | |
908 | ||
909 | /* | |
f40c67f0 | 910 | * Map cloned requests |
1da177e4 | 911 | */ |
f40c67f0 | 912 | static int multipath_map(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
913 | union map_info *map_context) |
914 | { | |
915 | int r; | |
028867ac | 916 | struct dm_mpath_io *mpio; |
1da177e4 LT |
917 | struct multipath *m = (struct multipath *) ti->private; |
918 | ||
f40c67f0 KU |
919 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); |
920 | if (!mpio) | |
921 | /* ENOMEM, requeue */ | |
922 | return DM_MAPIO_REQUEUE; | |
923 | memset(mpio, 0, sizeof(*mpio)); | |
1da177e4 LT |
924 | |
925 | map_context->ptr = mpio; | |
f40c67f0 KU |
926 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
927 | r = map_io(m, clone, mpio, 0); | |
45e15720 | 928 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
1da177e4 LT |
929 | mempool_free(mpio, m->mpio_pool); |
930 | ||
931 | return r; | |
932 | } | |
933 | ||
934 | /* | |
935 | * Take a path out of use. | |
936 | */ | |
937 | static int fail_path(struct pgpath *pgpath) | |
938 | { | |
939 | unsigned long flags; | |
940 | struct multipath *m = pgpath->pg->m; | |
941 | ||
942 | spin_lock_irqsave(&m->lock, flags); | |
943 | ||
6680073d | 944 | if (!pgpath->is_active) |
1da177e4 LT |
945 | goto out; |
946 | ||
72d94861 | 947 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
948 | |
949 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
6680073d | 950 | pgpath->is_active = 0; |
1da177e4 LT |
951 | pgpath->fail_count++; |
952 | ||
953 | m->nr_valid_paths--; | |
954 | ||
955 | if (pgpath == m->current_pgpath) | |
956 | m->current_pgpath = NULL; | |
957 | ||
b15546f9 MA |
958 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
959 | pgpath->path.dev->name, m->nr_valid_paths); | |
960 | ||
fe9cf30e | 961 | schedule_work(&m->trigger_event); |
224cb3e9 | 962 | queue_work(kmultipathd, &pgpath->deactivate_path); |
1da177e4 LT |
963 | |
964 | out: | |
965 | spin_unlock_irqrestore(&m->lock, flags); | |
966 | ||
967 | return 0; | |
968 | } | |
969 | ||
970 | /* | |
971 | * Reinstate a previously-failed path | |
972 | */ | |
973 | static int reinstate_path(struct pgpath *pgpath) | |
974 | { | |
975 | int r = 0; | |
976 | unsigned long flags; | |
977 | struct multipath *m = pgpath->pg->m; | |
978 | ||
979 | spin_lock_irqsave(&m->lock, flags); | |
980 | ||
6680073d | 981 | if (pgpath->is_active) |
1da177e4 LT |
982 | goto out; |
983 | ||
def052d2 | 984 | if (!pgpath->pg->ps.type->reinstate_path) { |
1da177e4 LT |
985 | DMWARN("Reinstate path not supported by path selector %s", |
986 | pgpath->pg->ps.type->name); | |
987 | r = -EINVAL; | |
988 | goto out; | |
989 | } | |
990 | ||
991 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
992 | if (r) | |
993 | goto out; | |
994 | ||
6680073d | 995 | pgpath->is_active = 1; |
1da177e4 | 996 | |
e54f77dd CS |
997 | if (!m->nr_valid_paths++ && m->queue_size) { |
998 | m->current_pgpath = NULL; | |
c557308e | 999 | queue_work(kmultipathd, &m->process_queued_ios); |
e54f77dd CS |
1000 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
1001 | if (queue_work(kmpath_handlerd, &pgpath->activate_path)) | |
1002 | m->pg_init_in_progress++; | |
1003 | } | |
1da177e4 | 1004 | |
b15546f9 MA |
1005 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
1006 | pgpath->path.dev->name, m->nr_valid_paths); | |
1007 | ||
fe9cf30e | 1008 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1009 | |
1010 | out: | |
1011 | spin_unlock_irqrestore(&m->lock, flags); | |
1012 | ||
1013 | return r; | |
1014 | } | |
1015 | ||
1016 | /* | |
1017 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1018 | */ | |
1019 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1020 | action_fn action) | |
1021 | { | |
1022 | int r = 0; | |
1023 | struct pgpath *pgpath; | |
1024 | struct priority_group *pg; | |
1025 | ||
1026 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1027 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1028 | if (pgpath->path.dev == dev) | |
1029 | r = action(pgpath); | |
1030 | } | |
1031 | } | |
1032 | ||
1033 | return r; | |
1034 | } | |
1035 | ||
1036 | /* | |
1037 | * Temporarily try to avoid having to use the specified PG | |
1038 | */ | |
1039 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
1040 | int bypassed) | |
1041 | { | |
1042 | unsigned long flags; | |
1043 | ||
1044 | spin_lock_irqsave(&m->lock, flags); | |
1045 | ||
1046 | pg->bypassed = bypassed; | |
1047 | m->current_pgpath = NULL; | |
1048 | m->current_pg = NULL; | |
1049 | ||
1050 | spin_unlock_irqrestore(&m->lock, flags); | |
1051 | ||
fe9cf30e | 1052 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1053 | } |
1054 | ||
1055 | /* | |
1056 | * Switch to using the specified PG from the next I/O that gets mapped | |
1057 | */ | |
1058 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1059 | { | |
1060 | struct priority_group *pg; | |
1061 | unsigned pgnum; | |
1062 | unsigned long flags; | |
1063 | ||
1064 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
1065 | (pgnum > m->nr_priority_groups)) { | |
1066 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
1067 | return -EINVAL; | |
1068 | } | |
1069 | ||
1070 | spin_lock_irqsave(&m->lock, flags); | |
1071 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1072 | pg->bypassed = 0; | |
1073 | if (--pgnum) | |
1074 | continue; | |
1075 | ||
1076 | m->current_pgpath = NULL; | |
1077 | m->current_pg = NULL; | |
1078 | m->next_pg = pg; | |
1079 | } | |
1080 | spin_unlock_irqrestore(&m->lock, flags); | |
1081 | ||
fe9cf30e | 1082 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1083 | return 0; |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * Set/clear bypassed status of a PG. | |
1088 | * PGs are numbered upwards from 1 in the order they were declared. | |
1089 | */ | |
1090 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
1091 | { | |
1092 | struct priority_group *pg; | |
1093 | unsigned pgnum; | |
1094 | ||
1095 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
1096 | (pgnum > m->nr_priority_groups)) { | |
1097 | DMWARN("invalid PG number supplied to bypass_pg"); | |
1098 | return -EINVAL; | |
1099 | } | |
1100 | ||
1101 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1102 | if (!--pgnum) | |
1103 | break; | |
1104 | } | |
1105 | ||
1106 | bypass_pg(m, pg, bypassed); | |
1107 | return 0; | |
1108 | } | |
1109 | ||
c9e45581 DW |
1110 | /* |
1111 | * Should we retry pg_init immediately? | |
1112 | */ | |
1113 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1114 | { | |
1115 | unsigned long flags; | |
1116 | int limit_reached = 0; | |
1117 | ||
1118 | spin_lock_irqsave(&m->lock, flags); | |
1119 | ||
1120 | if (m->pg_init_count <= m->pg_init_retries) | |
1121 | m->pg_init_required = 1; | |
1122 | else | |
1123 | limit_reached = 1; | |
1124 | ||
1125 | spin_unlock_irqrestore(&m->lock, flags); | |
1126 | ||
1127 | return limit_reached; | |
1128 | } | |
1129 | ||
3ae31f6a | 1130 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1131 | { |
83c0d5d5 | 1132 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1133 | struct priority_group *pg = pgpath->pg; |
1134 | struct multipath *m = pg->m; | |
1135 | unsigned long flags; | |
1136 | ||
1137 | /* device or driver problems */ | |
1138 | switch (errors) { | |
1139 | case SCSI_DH_OK: | |
1140 | break; | |
1141 | case SCSI_DH_NOSYS: | |
1142 | if (!m->hw_handler_name) { | |
1143 | errors = 0; | |
1144 | break; | |
1145 | } | |
f7b934c8 MB |
1146 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1147 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1148 | /* |
1149 | * Fail path for now, so we do not ping pong | |
1150 | */ | |
1151 | fail_path(pgpath); | |
1152 | break; | |
1153 | case SCSI_DH_DEV_TEMP_BUSY: | |
1154 | /* | |
1155 | * Probably doing something like FW upgrade on the | |
1156 | * controller so try the other pg. | |
1157 | */ | |
1158 | bypass_pg(m, pg, 1); | |
1159 | break; | |
1160 | /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */ | |
1161 | case SCSI_DH_RETRY: | |
1162 | case SCSI_DH_IMM_RETRY: | |
1163 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1164 | if (pg_init_limit_reached(m, pgpath)) | |
1165 | fail_path(pgpath); | |
1166 | errors = 0; | |
1167 | break; | |
1168 | default: | |
1169 | /* | |
1170 | * We probably do not want to fail the path for a device | |
1171 | * error, but this is what the old dm did. In future | |
1172 | * patches we can do more advanced handling. | |
1173 | */ | |
1174 | fail_path(pgpath); | |
1175 | } | |
1176 | ||
1177 | spin_lock_irqsave(&m->lock, flags); | |
1178 | if (errors) { | |
e54f77dd CS |
1179 | if (pgpath == m->current_pgpath) { |
1180 | DMERR("Could not failover device. Error %d.", errors); | |
1181 | m->current_pgpath = NULL; | |
1182 | m->current_pg = NULL; | |
1183 | } | |
d0259bf0 | 1184 | } else if (!m->pg_init_required) |
cfae5c9b | 1185 | pg->bypassed = 0; |
cfae5c9b | 1186 | |
d0259bf0 KU |
1187 | if (--m->pg_init_in_progress) |
1188 | /* Activations of other paths are still on going */ | |
1189 | goto out; | |
1190 | ||
1191 | if (!m->pg_init_required) | |
1192 | m->queue_io = 0; | |
1193 | ||
1194 | queue_work(kmultipathd, &m->process_queued_ios); | |
1195 | ||
1196 | out: | |
cfae5c9b CS |
1197 | spin_unlock_irqrestore(&m->lock, flags); |
1198 | } | |
1199 | ||
bab7cfc7 CS |
1200 | static void activate_path(struct work_struct *work) |
1201 | { | |
e54f77dd CS |
1202 | struct pgpath *pgpath = |
1203 | container_of(work, struct pgpath, activate_path); | |
bab7cfc7 | 1204 | |
3ae31f6a | 1205 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), |
83c0d5d5 | 1206 | pg_init_done, pgpath); |
bab7cfc7 CS |
1207 | } |
1208 | ||
1da177e4 LT |
1209 | /* |
1210 | * end_io handling | |
1211 | */ | |
f40c67f0 | 1212 | static int do_end_io(struct multipath *m, struct request *clone, |
028867ac | 1213 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1214 | { |
f40c67f0 KU |
1215 | /* |
1216 | * We don't queue any clone request inside the multipath target | |
1217 | * during end I/O handling, since those clone requests don't have | |
1218 | * bio clones. If we queue them inside the multipath target, | |
1219 | * we need to make bio clones, that requires memory allocation. | |
1220 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests | |
1221 | * don't have bio clones.) | |
1222 | * Instead of queueing the clone request here, we queue the original | |
1223 | * request into dm core, which will remake a clone request and | |
1224 | * clone bios for it and resubmit it later. | |
1225 | */ | |
1226 | int r = DM_ENDIO_REQUEUE; | |
640eb3b0 | 1227 | unsigned long flags; |
1da177e4 | 1228 | |
f40c67f0 | 1229 | if (!error && !clone->errors) |
1da177e4 LT |
1230 | return 0; /* I/O complete */ |
1231 | ||
f6a80ea8 AK |
1232 | if (error == -EOPNOTSUPP) |
1233 | return error; | |
1234 | ||
cfae5c9b CS |
1235 | if (mpio->pgpath) |
1236 | fail_path(mpio->pgpath); | |
1da177e4 | 1237 | |
640eb3b0 | 1238 | spin_lock_irqsave(&m->lock, flags); |
f40c67f0 KU |
1239 | if (!m->nr_valid_paths && !m->queue_if_no_path && !__must_push_back(m)) |
1240 | r = -EIO; | |
640eb3b0 | 1241 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1242 | |
f40c67f0 | 1243 | return r; |
1da177e4 LT |
1244 | } |
1245 | ||
f40c67f0 | 1246 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
1247 | int error, union map_info *map_context) |
1248 | { | |
028867ac AK |
1249 | struct multipath *m = ti->private; |
1250 | struct dm_mpath_io *mpio = map_context->ptr; | |
1da177e4 LT |
1251 | struct pgpath *pgpath = mpio->pgpath; |
1252 | struct path_selector *ps; | |
1253 | int r; | |
1254 | ||
f40c67f0 | 1255 | r = do_end_io(m, clone, error, mpio); |
1da177e4 LT |
1256 | if (pgpath) { |
1257 | ps = &pgpath->pg->ps; | |
1258 | if (ps->type->end_io) | |
02ab823f | 1259 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
1da177e4 | 1260 | } |
f40c67f0 | 1261 | mempool_free(mpio, m->mpio_pool); |
1da177e4 LT |
1262 | |
1263 | return r; | |
1264 | } | |
1265 | ||
1266 | /* | |
1267 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1268 | * the last path fails we must error any remaining I/O. |
1269 | * Note that if the freeze_bdev fails while suspending, the | |
1270 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1271 | */ |
1272 | static void multipath_presuspend(struct dm_target *ti) | |
1273 | { | |
1274 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1275 | |
485ef69e | 1276 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1277 | } |
1278 | ||
6df400ab KU |
1279 | static void multipath_postsuspend(struct dm_target *ti) |
1280 | { | |
6380f26f MA |
1281 | struct multipath *m = ti->private; |
1282 | ||
1283 | mutex_lock(&m->work_mutex); | |
6df400ab | 1284 | flush_multipath_work(); |
6380f26f | 1285 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1286 | } |
1287 | ||
436d4108 AK |
1288 | /* |
1289 | * Restore the queue_if_no_path setting. | |
1290 | */ | |
1da177e4 LT |
1291 | static void multipath_resume(struct dm_target *ti) |
1292 | { | |
1293 | struct multipath *m = (struct multipath *) ti->private; | |
1294 | unsigned long flags; | |
1295 | ||
1296 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1297 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1298 | spin_unlock_irqrestore(&m->lock, flags); |
1299 | } | |
1300 | ||
1301 | /* | |
1302 | * Info output has the following format: | |
1303 | * num_multipath_feature_args [multipath_feature_args]* | |
1304 | * num_handler_status_args [handler_status_args]* | |
1305 | * num_groups init_group_number | |
1306 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1307 | * num_paths num_selector_args | |
1308 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1309 | * | |
1310 | * Table output has the following format (identical to the constructor string): | |
1311 | * num_feature_args [features_args]* | |
1312 | * num_handler_args hw_handler [hw_handler_args]* | |
1313 | * num_groups init_group_number | |
1314 | * [priority selector-name num_ps_args [ps_args]* | |
1315 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1316 | */ | |
1317 | static int multipath_status(struct dm_target *ti, status_type_t type, | |
1318 | char *result, unsigned int maxlen) | |
1319 | { | |
1320 | int sz = 0; | |
1321 | unsigned long flags; | |
1322 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1323 | struct priority_group *pg; |
1324 | struct pgpath *p; | |
1325 | unsigned pg_num; | |
1326 | char state; | |
1327 | ||
1328 | spin_lock_irqsave(&m->lock, flags); | |
1329 | ||
1330 | /* Features */ | |
1331 | if (type == STATUSTYPE_INFO) | |
c9e45581 DW |
1332 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
1333 | else { | |
1334 | DMEMIT("%u ", m->queue_if_no_path + | |
1335 | (m->pg_init_retries > 0) * 2); | |
1336 | if (m->queue_if_no_path) | |
1337 | DMEMIT("queue_if_no_path "); | |
1338 | if (m->pg_init_retries) | |
1339 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
1340 | } | |
1da177e4 | 1341 | |
cfae5c9b | 1342 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1343 | DMEMIT("0 "); |
1344 | else | |
cfae5c9b | 1345 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1346 | |
1347 | DMEMIT("%u ", m->nr_priority_groups); | |
1348 | ||
1349 | if (m->next_pg) | |
1350 | pg_num = m->next_pg->pg_num; | |
1351 | else if (m->current_pg) | |
1352 | pg_num = m->current_pg->pg_num; | |
1353 | else | |
1354 | pg_num = 1; | |
1355 | ||
1356 | DMEMIT("%u ", pg_num); | |
1357 | ||
1358 | switch (type) { | |
1359 | case STATUSTYPE_INFO: | |
1360 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1361 | if (pg->bypassed) | |
1362 | state = 'D'; /* Disabled */ | |
1363 | else if (pg == m->current_pg) | |
1364 | state = 'A'; /* Currently Active */ | |
1365 | else | |
1366 | state = 'E'; /* Enabled */ | |
1367 | ||
1368 | DMEMIT("%c ", state); | |
1369 | ||
1370 | if (pg->ps.type->status) | |
1371 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1372 | result + sz, | |
1373 | maxlen - sz); | |
1374 | else | |
1375 | DMEMIT("0 "); | |
1376 | ||
1377 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1378 | pg->ps.type->info_args); | |
1379 | ||
1380 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1381 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1382 | p->is_active ? "A" : "F", |
1da177e4 LT |
1383 | p->fail_count); |
1384 | if (pg->ps.type->status) | |
1385 | sz += pg->ps.type->status(&pg->ps, | |
1386 | &p->path, type, result + sz, | |
1387 | maxlen - sz); | |
1388 | } | |
1389 | } | |
1390 | break; | |
1391 | ||
1392 | case STATUSTYPE_TABLE: | |
1393 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1394 | DMEMIT("%s ", pg->ps.type->name); | |
1395 | ||
1396 | if (pg->ps.type->status) | |
1397 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1398 | result + sz, | |
1399 | maxlen - sz); | |
1400 | else | |
1401 | DMEMIT("0 "); | |
1402 | ||
1403 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1404 | pg->ps.type->table_args); | |
1405 | ||
1406 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1407 | DMEMIT("%s ", p->path.dev->name); | |
1408 | if (pg->ps.type->status) | |
1409 | sz += pg->ps.type->status(&pg->ps, | |
1410 | &p->path, type, result + sz, | |
1411 | maxlen - sz); | |
1412 | } | |
1413 | } | |
1414 | break; | |
1415 | } | |
1416 | ||
1417 | spin_unlock_irqrestore(&m->lock, flags); | |
1418 | ||
1419 | return 0; | |
1420 | } | |
1421 | ||
1422 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1423 | { | |
6380f26f | 1424 | int r = -EINVAL; |
1da177e4 LT |
1425 | struct dm_dev *dev; |
1426 | struct multipath *m = (struct multipath *) ti->private; | |
1427 | action_fn action; | |
1428 | ||
6380f26f MA |
1429 | mutex_lock(&m->work_mutex); |
1430 | ||
c2f3d24b KU |
1431 | if (dm_suspended(ti)) { |
1432 | r = -EBUSY; | |
1433 | goto out; | |
1434 | } | |
1435 | ||
1da177e4 | 1436 | if (argc == 1) { |
6380f26f MA |
1437 | if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) { |
1438 | r = queue_if_no_path(m, 1, 0); | |
1439 | goto out; | |
1440 | } else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) { | |
1441 | r = queue_if_no_path(m, 0, 0); | |
1442 | goto out; | |
1443 | } | |
1da177e4 LT |
1444 | } |
1445 | ||
6380f26f MA |
1446 | if (argc != 2) { |
1447 | DMWARN("Unrecognised multipath message received."); | |
1448 | goto out; | |
1449 | } | |
1da177e4 | 1450 | |
6380f26f MA |
1451 | if (!strnicmp(argv[0], MESG_STR("disable_group"))) { |
1452 | r = bypass_pg_num(m, argv[1], 1); | |
1453 | goto out; | |
1454 | } else if (!strnicmp(argv[0], MESG_STR("enable_group"))) { | |
1455 | r = bypass_pg_num(m, argv[1], 0); | |
1456 | goto out; | |
1457 | } else if (!strnicmp(argv[0], MESG_STR("switch_group"))) { | |
1458 | r = switch_pg_num(m, argv[1]); | |
1459 | goto out; | |
1460 | } else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) | |
1da177e4 LT |
1461 | action = reinstate_path; |
1462 | else if (!strnicmp(argv[0], MESG_STR("fail_path"))) | |
1463 | action = fail_path; | |
6380f26f MA |
1464 | else { |
1465 | DMWARN("Unrecognised multipath message received."); | |
1466 | goto out; | |
1467 | } | |
1da177e4 LT |
1468 | |
1469 | r = dm_get_device(ti, argv[1], ti->begin, ti->len, | |
1470 | dm_table_get_mode(ti->table), &dev); | |
1471 | if (r) { | |
72d94861 | 1472 | DMWARN("message: error getting device %s", |
1da177e4 | 1473 | argv[1]); |
6380f26f | 1474 | goto out; |
1da177e4 LT |
1475 | } |
1476 | ||
1477 | r = action_dev(m, dev, action); | |
1478 | ||
1479 | dm_put_device(ti, dev); | |
1480 | ||
6380f26f MA |
1481 | out: |
1482 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 1483 | return r; |
1da177e4 LT |
1484 | } |
1485 | ||
647b3d00 | 1486 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
9af4aa30 MB |
1487 | unsigned long arg) |
1488 | { | |
1489 | struct multipath *m = (struct multipath *) ti->private; | |
1490 | struct block_device *bdev = NULL; | |
633a08b8 | 1491 | fmode_t mode = 0; |
9af4aa30 MB |
1492 | unsigned long flags; |
1493 | int r = 0; | |
1494 | ||
1495 | spin_lock_irqsave(&m->lock, flags); | |
1496 | ||
1497 | if (!m->current_pgpath) | |
02ab823f | 1498 | __choose_pgpath(m, 0); |
9af4aa30 | 1499 | |
e90dae1f | 1500 | if (m->current_pgpath) { |
9af4aa30 | 1501 | bdev = m->current_pgpath->path.dev->bdev; |
633a08b8 | 1502 | mode = m->current_pgpath->path.dev->mode; |
e90dae1f | 1503 | } |
9af4aa30 MB |
1504 | |
1505 | if (m->queue_io) | |
1506 | r = -EAGAIN; | |
1507 | else if (!bdev) | |
1508 | r = -EIO; | |
1509 | ||
1510 | spin_unlock_irqrestore(&m->lock, flags); | |
1511 | ||
633a08b8 | 1512 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
9af4aa30 MB |
1513 | } |
1514 | ||
af4874e0 MS |
1515 | static int multipath_iterate_devices(struct dm_target *ti, |
1516 | iterate_devices_callout_fn fn, void *data) | |
1517 | { | |
1518 | struct multipath *m = ti->private; | |
1519 | struct priority_group *pg; | |
1520 | struct pgpath *p; | |
1521 | int ret = 0; | |
1522 | ||
1523 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1524 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 1525 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
1526 | if (ret) |
1527 | goto out; | |
1528 | } | |
1529 | } | |
1530 | ||
1531 | out: | |
1532 | return ret; | |
1533 | } | |
1534 | ||
f40c67f0 KU |
1535 | static int __pgpath_busy(struct pgpath *pgpath) |
1536 | { | |
1537 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
1538 | ||
1539 | return dm_underlying_device_busy(q); | |
1540 | } | |
1541 | ||
1542 | /* | |
1543 | * We return "busy", only when we can map I/Os but underlying devices | |
1544 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
1545 | * the underlying queue). | |
1546 | * In other words, if we want to kill I/Os or queue them inside us | |
1547 | * due to map unavailability, we don't return "busy". Otherwise, | |
1548 | * dm core won't give us the I/Os and we can't do what we want. | |
1549 | */ | |
1550 | static int multipath_busy(struct dm_target *ti) | |
1551 | { | |
1552 | int busy = 0, has_active = 0; | |
1553 | struct multipath *m = ti->private; | |
1554 | struct priority_group *pg; | |
1555 | struct pgpath *pgpath; | |
1556 | unsigned long flags; | |
1557 | ||
1558 | spin_lock_irqsave(&m->lock, flags); | |
1559 | ||
1560 | /* Guess which priority_group will be used at next mapping time */ | |
1561 | if (unlikely(!m->current_pgpath && m->next_pg)) | |
1562 | pg = m->next_pg; | |
1563 | else if (likely(m->current_pg)) | |
1564 | pg = m->current_pg; | |
1565 | else | |
1566 | /* | |
1567 | * We don't know which pg will be used at next mapping time. | |
1568 | * We don't call __choose_pgpath() here to avoid to trigger | |
1569 | * pg_init just by busy checking. | |
1570 | * So we don't know whether underlying devices we will be using | |
1571 | * at next mapping time are busy or not. Just try mapping. | |
1572 | */ | |
1573 | goto out; | |
1574 | ||
1575 | /* | |
1576 | * If there is one non-busy active path at least, the path selector | |
1577 | * will be able to select it. So we consider such a pg as not busy. | |
1578 | */ | |
1579 | busy = 1; | |
1580 | list_for_each_entry(pgpath, &pg->pgpaths, list) | |
1581 | if (pgpath->is_active) { | |
1582 | has_active = 1; | |
1583 | ||
1584 | if (!__pgpath_busy(pgpath)) { | |
1585 | busy = 0; | |
1586 | break; | |
1587 | } | |
1588 | } | |
1589 | ||
1590 | if (!has_active) | |
1591 | /* | |
1592 | * No active path in this pg, so this pg won't be used and | |
1593 | * the current_pg will be changed at next mapping time. | |
1594 | * We need to try mapping to determine it. | |
1595 | */ | |
1596 | busy = 0; | |
1597 | ||
1598 | out: | |
1599 | spin_unlock_irqrestore(&m->lock, flags); | |
1600 | ||
1601 | return busy; | |
1602 | } | |
1603 | ||
1da177e4 LT |
1604 | /*----------------------------------------------------------------- |
1605 | * Module setup | |
1606 | *---------------------------------------------------------------*/ | |
1607 | static struct target_type multipath_target = { | |
1608 | .name = "multipath", | |
6df400ab | 1609 | .version = {1, 1, 1}, |
1da177e4 LT |
1610 | .module = THIS_MODULE, |
1611 | .ctr = multipath_ctr, | |
1612 | .dtr = multipath_dtr, | |
f40c67f0 KU |
1613 | .map_rq = multipath_map, |
1614 | .rq_end_io = multipath_end_io, | |
1da177e4 | 1615 | .presuspend = multipath_presuspend, |
6df400ab | 1616 | .postsuspend = multipath_postsuspend, |
1da177e4 LT |
1617 | .resume = multipath_resume, |
1618 | .status = multipath_status, | |
1619 | .message = multipath_message, | |
9af4aa30 | 1620 | .ioctl = multipath_ioctl, |
af4874e0 | 1621 | .iterate_devices = multipath_iterate_devices, |
f40c67f0 | 1622 | .busy = multipath_busy, |
1da177e4 LT |
1623 | }; |
1624 | ||
1625 | static int __init dm_multipath_init(void) | |
1626 | { | |
1627 | int r; | |
1628 | ||
1629 | /* allocate a slab for the dm_ios */ | |
028867ac | 1630 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1631 | if (!_mpio_cache) |
1632 | return -ENOMEM; | |
1633 | ||
1634 | r = dm_register_target(&multipath_target); | |
1635 | if (r < 0) { | |
0cd33124 | 1636 | DMERR("register failed %d", r); |
1da177e4 LT |
1637 | kmem_cache_destroy(_mpio_cache); |
1638 | return -EINVAL; | |
1639 | } | |
1640 | ||
c557308e AK |
1641 | kmultipathd = create_workqueue("kmpathd"); |
1642 | if (!kmultipathd) { | |
0cd33124 | 1643 | DMERR("failed to create workqueue kmpathd"); |
c557308e AK |
1644 | dm_unregister_target(&multipath_target); |
1645 | kmem_cache_destroy(_mpio_cache); | |
1646 | return -ENOMEM; | |
1647 | } | |
1648 | ||
bab7cfc7 CS |
1649 | /* |
1650 | * A separate workqueue is used to handle the device handlers | |
1651 | * to avoid overloading existing workqueue. Overloading the | |
1652 | * old workqueue would also create a bottleneck in the | |
1653 | * path of the storage hardware device activation. | |
1654 | */ | |
1655 | kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd"); | |
1656 | if (!kmpath_handlerd) { | |
1657 | DMERR("failed to create workqueue kmpath_handlerd"); | |
1658 | destroy_workqueue(kmultipathd); | |
1659 | dm_unregister_target(&multipath_target); | |
1660 | kmem_cache_destroy(_mpio_cache); | |
1661 | return -ENOMEM; | |
1662 | } | |
1663 | ||
72d94861 | 1664 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1665 | multipath_target.version[0], multipath_target.version[1], |
1666 | multipath_target.version[2]); | |
1667 | ||
1668 | return r; | |
1669 | } | |
1670 | ||
1671 | static void __exit dm_multipath_exit(void) | |
1672 | { | |
bab7cfc7 | 1673 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1674 | destroy_workqueue(kmultipathd); |
1675 | ||
10d3bd09 | 1676 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
1677 | kmem_cache_destroy(_mpio_cache); |
1678 | } | |
1679 | ||
1da177e4 LT |
1680 | module_init(dm_multipath_init); |
1681 | module_exit(dm_multipath_exit); | |
1682 | ||
1683 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1684 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1685 | MODULE_LICENSE("GPL"); |