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Commit | Line | Data |
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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; |
e54f77dd | 36 | struct work_struct activate_path; |
1da177e4 LT |
37 | }; |
38 | ||
39 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
40 | ||
41 | /* | |
42 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
43 | * Each has a path selector which controls which path gets used. | |
44 | */ | |
45 | struct priority_group { | |
46 | struct list_head list; | |
47 | ||
48 | struct multipath *m; /* Owning multipath instance */ | |
49 | struct path_selector ps; | |
50 | ||
51 | unsigned pg_num; /* Reference number */ | |
52 | unsigned bypassed; /* Temporarily bypass this PG? */ | |
53 | ||
54 | unsigned nr_pgpaths; /* Number of paths in PG */ | |
55 | struct list_head pgpaths; | |
56 | }; | |
57 | ||
58 | /* Multipath context */ | |
59 | struct multipath { | |
60 | struct list_head list; | |
61 | struct dm_target *ti; | |
62 | ||
63 | spinlock_t lock; | |
64 | ||
cfae5c9b | 65 | const char *hw_handler_name; |
2bfd2e13 | 66 | char *hw_handler_params; |
1da177e4 LT |
67 | unsigned nr_priority_groups; |
68 | struct list_head priority_groups; | |
69 | unsigned pg_init_required; /* pg_init needs calling? */ | |
c3cd4f6b | 70 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
2bded7bd | 71 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ |
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); |
1da177e4 LT |
118 | |
119 | ||
120 | /*----------------------------------------------- | |
121 | * Allocation routines | |
122 | *-----------------------------------------------*/ | |
123 | ||
124 | static struct pgpath *alloc_pgpath(void) | |
125 | { | |
e69fae56 | 126 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 127 | |
224cb3e9 | 128 | if (pgpath) { |
6680073d | 129 | pgpath->is_active = 1; |
e54f77dd | 130 | INIT_WORK(&pgpath->activate_path, activate_path); |
224cb3e9 | 131 | } |
1da177e4 LT |
132 | |
133 | return pgpath; | |
134 | } | |
135 | ||
028867ac | 136 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
137 | { |
138 | kfree(pgpath); | |
139 | } | |
140 | ||
141 | static struct priority_group *alloc_priority_group(void) | |
142 | { | |
143 | struct priority_group *pg; | |
144 | ||
e69fae56 | 145 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 146 | |
e69fae56 MM |
147 | if (pg) |
148 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
149 | |
150 | return pg; | |
151 | } | |
152 | ||
153 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
154 | { | |
155 | struct pgpath *pgpath, *tmp; | |
ae11b1b3 | 156 | struct multipath *m = ti->private; |
1da177e4 LT |
157 | |
158 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
159 | list_del(&pgpath->list); | |
ae11b1b3 HR |
160 | if (m->hw_handler_name) |
161 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); | |
1da177e4 LT |
162 | dm_put_device(ti, pgpath->path.dev); |
163 | free_pgpath(pgpath); | |
164 | } | |
165 | } | |
166 | ||
167 | static void free_priority_group(struct priority_group *pg, | |
168 | struct dm_target *ti) | |
169 | { | |
170 | struct path_selector *ps = &pg->ps; | |
171 | ||
172 | if (ps->type) { | |
173 | ps->type->destroy(ps); | |
174 | dm_put_path_selector(ps->type); | |
175 | } | |
176 | ||
177 | free_pgpaths(&pg->pgpaths, ti); | |
178 | kfree(pg); | |
179 | } | |
180 | ||
28f16c20 | 181 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
182 | { |
183 | struct multipath *m; | |
184 | ||
e69fae56 | 185 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 186 | if (m) { |
1da177e4 | 187 | INIT_LIST_HEAD(&m->priority_groups); |
f40c67f0 | 188 | INIT_LIST_HEAD(&m->queued_ios); |
1da177e4 LT |
189 | spin_lock_init(&m->lock); |
190 | m->queue_io = 1; | |
c4028958 DH |
191 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
192 | INIT_WORK(&m->trigger_event, trigger_event); | |
2bded7bd | 193 | init_waitqueue_head(&m->pg_init_wait); |
6380f26f | 194 | mutex_init(&m->work_mutex); |
93d2341c | 195 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
1da177e4 LT |
196 | if (!m->mpio_pool) { |
197 | kfree(m); | |
198 | return NULL; | |
199 | } | |
28f16c20 MM |
200 | m->ti = ti; |
201 | ti->private = m; | |
1da177e4 LT |
202 | } |
203 | ||
204 | return m; | |
205 | } | |
206 | ||
207 | static void free_multipath(struct multipath *m) | |
208 | { | |
209 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
210 | |
211 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
212 | list_del(&pg->list); | |
213 | free_priority_group(pg, m->ti); | |
214 | } | |
215 | ||
cfae5c9b | 216 | kfree(m->hw_handler_name); |
2bfd2e13 | 217 | kfree(m->hw_handler_params); |
1da177e4 LT |
218 | mempool_destroy(m->mpio_pool); |
219 | kfree(m); | |
220 | } | |
221 | ||
222 | ||
223 | /*----------------------------------------------- | |
224 | * Path selection | |
225 | *-----------------------------------------------*/ | |
226 | ||
fb612642 KU |
227 | static void __pg_init_all_paths(struct multipath *m) |
228 | { | |
229 | struct pgpath *pgpath; | |
230 | ||
231 | m->pg_init_count++; | |
232 | m->pg_init_required = 0; | |
233 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { | |
234 | /* Skip failed paths */ | |
235 | if (!pgpath->is_active) | |
236 | continue; | |
237 | if (queue_work(kmpath_handlerd, &pgpath->activate_path)) | |
238 | m->pg_init_in_progress++; | |
239 | } | |
240 | } | |
241 | ||
1da177e4 LT |
242 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) |
243 | { | |
1da177e4 LT |
244 | m->current_pg = pgpath->pg; |
245 | ||
246 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 247 | if (m->hw_handler_name) { |
1da177e4 LT |
248 | m->pg_init_required = 1; |
249 | m->queue_io = 1; | |
250 | } else { | |
251 | m->pg_init_required = 0; | |
252 | m->queue_io = 0; | |
253 | } | |
c9e45581 DW |
254 | |
255 | m->pg_init_count = 0; | |
1da177e4 LT |
256 | } |
257 | ||
02ab823f KU |
258 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
259 | size_t nr_bytes) | |
1da177e4 | 260 | { |
c922d5f7 | 261 | struct dm_path *path; |
1da177e4 | 262 | |
02ab823f | 263 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes); |
1da177e4 LT |
264 | if (!path) |
265 | return -ENXIO; | |
266 | ||
267 | m->current_pgpath = path_to_pgpath(path); | |
268 | ||
269 | if (m->current_pg != pg) | |
270 | __switch_pg(m, m->current_pgpath); | |
271 | ||
272 | return 0; | |
273 | } | |
274 | ||
02ab823f | 275 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 LT |
276 | { |
277 | struct priority_group *pg; | |
278 | unsigned bypassed = 1; | |
279 | ||
280 | if (!m->nr_valid_paths) | |
281 | goto failed; | |
282 | ||
283 | /* Were we instructed to switch PG? */ | |
284 | if (m->next_pg) { | |
285 | pg = m->next_pg; | |
286 | m->next_pg = NULL; | |
02ab823f | 287 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
288 | return; |
289 | } | |
290 | ||
291 | /* Don't change PG until it has no remaining paths */ | |
02ab823f | 292 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes)) |
1da177e4 LT |
293 | return; |
294 | ||
295 | /* | |
296 | * Loop through priority groups until we find a valid path. | |
297 | * First time we skip PGs marked 'bypassed'. | |
298 | * Second time we only try the ones we skipped. | |
299 | */ | |
300 | do { | |
301 | list_for_each_entry(pg, &m->priority_groups, list) { | |
302 | if (pg->bypassed == bypassed) | |
303 | continue; | |
02ab823f | 304 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
305 | return; |
306 | } | |
307 | } while (bypassed--); | |
308 | ||
309 | failed: | |
310 | m->current_pgpath = NULL; | |
311 | m->current_pg = NULL; | |
312 | } | |
313 | ||
45e15720 KU |
314 | /* |
315 | * Check whether bios must be queued in the device-mapper core rather | |
316 | * than here in the target. | |
317 | * | |
318 | * m->lock must be held on entry. | |
319 | * | |
320 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
321 | * same value then we are not between multipath_presuspend() | |
322 | * and multipath_resume() calls and we have no need to check | |
323 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
324 | */ | |
325 | static int __must_push_back(struct multipath *m) | |
326 | { | |
327 | return (m->queue_if_no_path != m->saved_queue_if_no_path && | |
328 | dm_noflush_suspending(m->ti)); | |
329 | } | |
330 | ||
f40c67f0 | 331 | static int map_io(struct multipath *m, struct request *clone, |
028867ac | 332 | struct dm_mpath_io *mpio, unsigned was_queued) |
1da177e4 | 333 | { |
d2a7ad29 | 334 | int r = DM_MAPIO_REMAPPED; |
f40c67f0 | 335 | size_t nr_bytes = blk_rq_bytes(clone); |
1da177e4 LT |
336 | unsigned long flags; |
337 | struct pgpath *pgpath; | |
f40c67f0 | 338 | struct block_device *bdev; |
1da177e4 LT |
339 | |
340 | spin_lock_irqsave(&m->lock, flags); | |
341 | ||
342 | /* Do we need to select a new pgpath? */ | |
343 | if (!m->current_pgpath || | |
344 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
02ab823f | 345 | __choose_pgpath(m, nr_bytes); |
1da177e4 LT |
346 | |
347 | pgpath = m->current_pgpath; | |
348 | ||
349 | if (was_queued) | |
350 | m->queue_size--; | |
351 | ||
352 | if ((pgpath && m->queue_io) || | |
436d4108 | 353 | (!pgpath && m->queue_if_no_path)) { |
1da177e4 | 354 | /* Queue for the daemon to resubmit */ |
f40c67f0 | 355 | list_add_tail(&clone->queuelist, &m->queued_ios); |
1da177e4 | 356 | m->queue_size++; |
c3cd4f6b AK |
357 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
358 | !m->queue_io) | |
c557308e | 359 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 360 | pgpath = NULL; |
d2a7ad29 | 361 | r = DM_MAPIO_SUBMITTED; |
f40c67f0 KU |
362 | } else if (pgpath) { |
363 | bdev = pgpath->path.dev->bdev; | |
364 | clone->q = bdev_get_queue(bdev); | |
365 | clone->rq_disk = bdev->bd_disk; | |
366 | } else if (__must_push_back(m)) | |
45e15720 KU |
367 | r = DM_MAPIO_REQUEUE; |
368 | else | |
369 | r = -EIO; /* Failed */ | |
1da177e4 LT |
370 | |
371 | mpio->pgpath = pgpath; | |
02ab823f KU |
372 | mpio->nr_bytes = nr_bytes; |
373 | ||
374 | if (r == DM_MAPIO_REMAPPED && pgpath->pg->ps.type->start_io) | |
375 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, &pgpath->path, | |
376 | nr_bytes); | |
1da177e4 LT |
377 | |
378 | spin_unlock_irqrestore(&m->lock, flags); | |
379 | ||
380 | return r; | |
381 | } | |
382 | ||
383 | /* | |
384 | * If we run out of usable paths, should we queue I/O or error it? | |
385 | */ | |
485ef69e AK |
386 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
387 | unsigned save_old_value) | |
1da177e4 LT |
388 | { |
389 | unsigned long flags; | |
390 | ||
391 | spin_lock_irqsave(&m->lock, flags); | |
392 | ||
485ef69e AK |
393 | if (save_old_value) |
394 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
395 | else | |
396 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 397 | m->queue_if_no_path = queue_if_no_path; |
c3cd4f6b | 398 | if (!m->queue_if_no_path && m->queue_size) |
c557308e | 399 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
400 | |
401 | spin_unlock_irqrestore(&m->lock, flags); | |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
406 | /*----------------------------------------------------------------- | |
407 | * The multipath daemon is responsible for resubmitting queued ios. | |
408 | *---------------------------------------------------------------*/ | |
409 | ||
410 | static void dispatch_queued_ios(struct multipath *m) | |
411 | { | |
412 | int r; | |
413 | unsigned long flags; | |
028867ac | 414 | struct dm_mpath_io *mpio; |
1da177e4 | 415 | union map_info *info; |
f40c67f0 KU |
416 | struct request *clone, *n; |
417 | LIST_HEAD(cl); | |
1da177e4 LT |
418 | |
419 | spin_lock_irqsave(&m->lock, flags); | |
f40c67f0 | 420 | list_splice_init(&m->queued_ios, &cl); |
1da177e4 LT |
421 | spin_unlock_irqrestore(&m->lock, flags); |
422 | ||
f40c67f0 KU |
423 | list_for_each_entry_safe(clone, n, &cl, queuelist) { |
424 | list_del_init(&clone->queuelist); | |
1da177e4 | 425 | |
f40c67f0 | 426 | info = dm_get_rq_mapinfo(clone); |
1da177e4 LT |
427 | mpio = info->ptr; |
428 | ||
f40c67f0 KU |
429 | r = map_io(m, clone, mpio, 1); |
430 | if (r < 0) { | |
431 | mempool_free(mpio, m->mpio_pool); | |
432 | dm_kill_unmapped_request(clone, r); | |
433 | } else if (r == DM_MAPIO_REMAPPED) | |
434 | dm_dispatch_request(clone); | |
435 | else if (r == DM_MAPIO_REQUEUE) { | |
436 | mempool_free(mpio, m->mpio_pool); | |
437 | dm_requeue_unmapped_request(clone); | |
438 | } | |
1da177e4 LT |
439 | } |
440 | } | |
441 | ||
c4028958 | 442 | static void process_queued_ios(struct work_struct *work) |
1da177e4 | 443 | { |
c4028958 DH |
444 | struct multipath *m = |
445 | container_of(work, struct multipath, process_queued_ios); | |
fb612642 | 446 | struct pgpath *pgpath = NULL; |
e54f77dd | 447 | unsigned must_queue = 1; |
1da177e4 LT |
448 | unsigned long flags; |
449 | ||
450 | spin_lock_irqsave(&m->lock, flags); | |
451 | ||
c3cd4f6b AK |
452 | if (!m->queue_size) |
453 | goto out; | |
454 | ||
1da177e4 | 455 | if (!m->current_pgpath) |
02ab823f | 456 | __choose_pgpath(m, 0); |
1da177e4 LT |
457 | |
458 | pgpath = m->current_pgpath; | |
459 | ||
c3cd4f6b AK |
460 | if ((pgpath && !m->queue_io) || |
461 | (!pgpath && !m->queue_if_no_path)) | |
462 | must_queue = 0; | |
1da177e4 | 463 | |
fb612642 KU |
464 | if (m->pg_init_required && !m->pg_init_in_progress && pgpath) |
465 | __pg_init_all_paths(m); | |
466 | ||
c3cd4f6b | 467 | out: |
1da177e4 | 468 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
469 | if (!must_queue) |
470 | dispatch_queued_ios(m); | |
471 | } | |
472 | ||
473 | /* | |
474 | * An event is triggered whenever a path is taken out of use. | |
475 | * Includes path failure and PG bypass. | |
476 | */ | |
c4028958 | 477 | static void trigger_event(struct work_struct *work) |
1da177e4 | 478 | { |
c4028958 DH |
479 | struct multipath *m = |
480 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
481 | |
482 | dm_table_event(m->ti->table); | |
483 | } | |
484 | ||
485 | /*----------------------------------------------------------------- | |
486 | * Constructor/argument parsing: | |
487 | * <#multipath feature args> [<arg>]* | |
488 | * <#hw_handler args> [hw_handler [<arg>]*] | |
489 | * <#priority groups> | |
490 | * <initial priority group> | |
491 | * [<selector> <#selector args> [<arg>]* | |
492 | * <#paths> <#per-path selector args> | |
493 | * [<path> [<arg>]* ]+ ]+ | |
494 | *---------------------------------------------------------------*/ | |
495 | struct param { | |
496 | unsigned min; | |
497 | unsigned max; | |
498 | char *error; | |
499 | }; | |
500 | ||
1da177e4 LT |
501 | static int read_param(struct param *param, char *str, unsigned *v, char **error) |
502 | { | |
503 | if (!str || | |
504 | (sscanf(str, "%u", v) != 1) || | |
505 | (*v < param->min) || | |
506 | (*v > param->max)) { | |
507 | *error = param->error; | |
508 | return -EINVAL; | |
509 | } | |
510 | ||
511 | return 0; | |
512 | } | |
513 | ||
514 | struct arg_set { | |
515 | unsigned argc; | |
516 | char **argv; | |
517 | }; | |
518 | ||
519 | static char *shift(struct arg_set *as) | |
520 | { | |
521 | char *r; | |
522 | ||
523 | if (as->argc) { | |
524 | as->argc--; | |
525 | r = *as->argv; | |
526 | as->argv++; | |
527 | return r; | |
528 | } | |
529 | ||
530 | return NULL; | |
531 | } | |
532 | ||
533 | static void consume(struct arg_set *as, unsigned n) | |
534 | { | |
535 | BUG_ON (as->argc < n); | |
536 | as->argc -= n; | |
537 | as->argv += n; | |
538 | } | |
539 | ||
540 | static int parse_path_selector(struct arg_set *as, struct priority_group *pg, | |
541 | struct dm_target *ti) | |
542 | { | |
543 | int r; | |
544 | struct path_selector_type *pst; | |
545 | unsigned ps_argc; | |
546 | ||
547 | static struct param _params[] = { | |
72d94861 | 548 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
549 | }; |
550 | ||
551 | pst = dm_get_path_selector(shift(as)); | |
552 | if (!pst) { | |
72d94861 | 553 | ti->error = "unknown path selector type"; |
1da177e4 LT |
554 | return -EINVAL; |
555 | } | |
556 | ||
557 | r = read_param(_params, shift(as), &ps_argc, &ti->error); | |
371b2e34 MP |
558 | if (r) { |
559 | dm_put_path_selector(pst); | |
1da177e4 | 560 | return -EINVAL; |
371b2e34 | 561 | } |
1da177e4 | 562 | |
0e0497c0 MP |
563 | if (ps_argc > as->argc) { |
564 | dm_put_path_selector(pst); | |
565 | ti->error = "not enough arguments for path selector"; | |
566 | return -EINVAL; | |
567 | } | |
568 | ||
1da177e4 LT |
569 | r = pst->create(&pg->ps, ps_argc, as->argv); |
570 | if (r) { | |
571 | dm_put_path_selector(pst); | |
72d94861 | 572 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
573 | return r; |
574 | } | |
575 | ||
576 | pg->ps.type = pst; | |
577 | consume(as, ps_argc); | |
578 | ||
579 | return 0; | |
580 | } | |
581 | ||
582 | static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, | |
583 | struct dm_target *ti) | |
584 | { | |
585 | int r; | |
586 | struct pgpath *p; | |
ae11b1b3 | 587 | struct multipath *m = ti->private; |
1da177e4 LT |
588 | |
589 | /* we need at least a path arg */ | |
590 | if (as->argc < 1) { | |
72d94861 | 591 | ti->error = "no device given"; |
01460f35 | 592 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
593 | } |
594 | ||
595 | p = alloc_pgpath(); | |
596 | if (!p) | |
01460f35 | 597 | return ERR_PTR(-ENOMEM); |
1da177e4 | 598 | |
8215d6ec NK |
599 | r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table), |
600 | &p->path.dev); | |
1da177e4 | 601 | if (r) { |
72d94861 | 602 | ti->error = "error getting device"; |
1da177e4 LT |
603 | goto bad; |
604 | } | |
605 | ||
ae11b1b3 | 606 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
607 | struct request_queue *q = bdev_get_queue(p->path.dev->bdev); |
608 | ||
609 | r = scsi_dh_attach(q, m->hw_handler_name); | |
610 | if (r == -EBUSY) { | |
611 | /* | |
612 | * Already attached to different hw_handler, | |
613 | * try to reattach with correct one. | |
614 | */ | |
615 | scsi_dh_detach(q); | |
616 | r = scsi_dh_attach(q, m->hw_handler_name); | |
617 | } | |
618 | ||
ae11b1b3 | 619 | if (r < 0) { |
a0cf7ea9 | 620 | ti->error = "error attaching hardware handler"; |
ae11b1b3 HR |
621 | dm_put_device(ti, p->path.dev); |
622 | goto bad; | |
623 | } | |
2bfd2e13 CS |
624 | |
625 | if (m->hw_handler_params) { | |
626 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
627 | if (r < 0) { | |
628 | ti->error = "unable to set hardware " | |
629 | "handler parameters"; | |
630 | scsi_dh_detach(q); | |
631 | dm_put_device(ti, p->path.dev); | |
632 | goto bad; | |
633 | } | |
634 | } | |
ae11b1b3 HR |
635 | } |
636 | ||
1da177e4 LT |
637 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
638 | if (r) { | |
639 | dm_put_device(ti, p->path.dev); | |
640 | goto bad; | |
641 | } | |
642 | ||
643 | return p; | |
644 | ||
645 | bad: | |
646 | free_pgpath(p); | |
01460f35 | 647 | return ERR_PTR(r); |
1da177e4 LT |
648 | } |
649 | ||
650 | static struct priority_group *parse_priority_group(struct arg_set *as, | |
28f16c20 | 651 | struct multipath *m) |
1da177e4 LT |
652 | { |
653 | static struct param _params[] = { | |
72d94861 AK |
654 | {1, 1024, "invalid number of paths"}, |
655 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
656 | }; |
657 | ||
658 | int r; | |
659 | unsigned i, nr_selector_args, nr_params; | |
660 | struct priority_group *pg; | |
28f16c20 | 661 | struct dm_target *ti = m->ti; |
1da177e4 LT |
662 | |
663 | if (as->argc < 2) { | |
664 | as->argc = 0; | |
01460f35 BM |
665 | ti->error = "not enough priority group arguments"; |
666 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
667 | } |
668 | ||
669 | pg = alloc_priority_group(); | |
670 | if (!pg) { | |
72d94861 | 671 | ti->error = "couldn't allocate priority group"; |
01460f35 | 672 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
673 | } |
674 | pg->m = m; | |
675 | ||
676 | r = parse_path_selector(as, pg, ti); | |
677 | if (r) | |
678 | goto bad; | |
679 | ||
680 | /* | |
681 | * read the paths | |
682 | */ | |
683 | r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error); | |
684 | if (r) | |
685 | goto bad; | |
686 | ||
687 | r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error); | |
688 | if (r) | |
689 | goto bad; | |
690 | ||
691 | nr_params = 1 + nr_selector_args; | |
692 | for (i = 0; i < pg->nr_pgpaths; i++) { | |
693 | struct pgpath *pgpath; | |
694 | struct arg_set path_args; | |
695 | ||
148acff6 MP |
696 | if (as->argc < nr_params) { |
697 | ti->error = "not enough path parameters"; | |
6bbf79a1 | 698 | r = -EINVAL; |
1da177e4 | 699 | goto bad; |
148acff6 | 700 | } |
1da177e4 LT |
701 | |
702 | path_args.argc = nr_params; | |
703 | path_args.argv = as->argv; | |
704 | ||
705 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
706 | if (IS_ERR(pgpath)) { |
707 | r = PTR_ERR(pgpath); | |
1da177e4 | 708 | goto bad; |
01460f35 | 709 | } |
1da177e4 LT |
710 | |
711 | pgpath->pg = pg; | |
712 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
713 | consume(as, nr_params); | |
714 | } | |
715 | ||
716 | return pg; | |
717 | ||
718 | bad: | |
719 | free_priority_group(pg, ti); | |
01460f35 | 720 | return ERR_PTR(r); |
1da177e4 LT |
721 | } |
722 | ||
28f16c20 | 723 | static int parse_hw_handler(struct arg_set *as, struct multipath *m) |
1da177e4 | 724 | { |
1da177e4 | 725 | unsigned hw_argc; |
2bfd2e13 | 726 | int ret; |
28f16c20 | 727 | struct dm_target *ti = m->ti; |
1da177e4 LT |
728 | |
729 | static struct param _params[] = { | |
72d94861 | 730 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
731 | }; |
732 | ||
cfae5c9b | 733 | if (read_param(_params, shift(as), &hw_argc, &ti->error)) |
1da177e4 LT |
734 | return -EINVAL; |
735 | ||
736 | if (!hw_argc) | |
737 | return 0; | |
738 | ||
e094f4f1 MP |
739 | if (hw_argc > as->argc) { |
740 | ti->error = "not enough arguments for hardware handler"; | |
741 | return -EINVAL; | |
742 | } | |
743 | ||
cfae5c9b CS |
744 | m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL); |
745 | request_module("scsi_dh_%s", m->hw_handler_name); | |
746 | if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { | |
72d94861 | 747 | ti->error = "unknown hardware handler type"; |
2bfd2e13 CS |
748 | ret = -EINVAL; |
749 | goto fail; | |
1da177e4 | 750 | } |
14e98c5c | 751 | |
2bfd2e13 CS |
752 | if (hw_argc > 1) { |
753 | char *p; | |
754 | int i, j, len = 4; | |
755 | ||
756 | for (i = 0; i <= hw_argc - 2; i++) | |
757 | len += strlen(as->argv[i]) + 1; | |
758 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
759 | if (!p) { | |
760 | ti->error = "memory allocation failed"; | |
761 | ret = -ENOMEM; | |
762 | goto fail; | |
763 | } | |
764 | j = sprintf(p, "%d", hw_argc - 1); | |
765 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
766 | j = sprintf(p, "%s", as->argv[i]); | |
767 | } | |
1da177e4 LT |
768 | consume(as, hw_argc - 1); |
769 | ||
770 | return 0; | |
2bfd2e13 CS |
771 | fail: |
772 | kfree(m->hw_handler_name); | |
773 | m->hw_handler_name = NULL; | |
774 | return ret; | |
1da177e4 LT |
775 | } |
776 | ||
28f16c20 | 777 | static int parse_features(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
778 | { |
779 | int r; | |
780 | unsigned argc; | |
28f16c20 | 781 | struct dm_target *ti = m->ti; |
c9e45581 | 782 | const char *param_name; |
1da177e4 LT |
783 | |
784 | static struct param _params[] = { | |
c9e45581 DW |
785 | {0, 3, "invalid number of feature args"}, |
786 | {1, 50, "pg_init_retries must be between 1 and 50"}, | |
1da177e4 LT |
787 | }; |
788 | ||
789 | r = read_param(_params, shift(as), &argc, &ti->error); | |
790 | if (r) | |
791 | return -EINVAL; | |
792 | ||
793 | if (!argc) | |
794 | return 0; | |
795 | ||
c9e45581 DW |
796 | do { |
797 | param_name = shift(as); | |
798 | argc--; | |
799 | ||
800 | if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { | |
801 | r = queue_if_no_path(m, 1, 0); | |
802 | continue; | |
803 | } | |
804 | ||
805 | if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && | |
806 | (argc >= 1)) { | |
807 | r = read_param(_params + 1, shift(as), | |
808 | &m->pg_init_retries, &ti->error); | |
809 | argc--; | |
810 | continue; | |
811 | } | |
812 | ||
1da177e4 | 813 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
814 | r = -EINVAL; |
815 | } while (argc && !r); | |
816 | ||
817 | return r; | |
1da177e4 LT |
818 | } |
819 | ||
820 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
821 | char **argv) | |
822 | { | |
823 | /* target parameters */ | |
824 | static struct param _params[] = { | |
72d94861 AK |
825 | {1, 1024, "invalid number of priority groups"}, |
826 | {1, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
827 | }; |
828 | ||
829 | int r; | |
830 | struct multipath *m; | |
831 | struct arg_set as; | |
832 | unsigned pg_count = 0; | |
833 | unsigned next_pg_num; | |
834 | ||
835 | as.argc = argc; | |
836 | as.argv = argv; | |
837 | ||
28f16c20 | 838 | m = alloc_multipath(ti); |
1da177e4 | 839 | if (!m) { |
72d94861 | 840 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
841 | return -EINVAL; |
842 | } | |
843 | ||
28f16c20 | 844 | r = parse_features(&as, m); |
1da177e4 LT |
845 | if (r) |
846 | goto bad; | |
847 | ||
28f16c20 | 848 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
849 | if (r) |
850 | goto bad; | |
851 | ||
852 | r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error); | |
853 | if (r) | |
854 | goto bad; | |
855 | ||
856 | r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error); | |
857 | if (r) | |
858 | goto bad; | |
859 | ||
860 | /* parse the priority groups */ | |
861 | while (as.argc) { | |
862 | struct priority_group *pg; | |
863 | ||
28f16c20 | 864 | pg = parse_priority_group(&as, m); |
01460f35 BM |
865 | if (IS_ERR(pg)) { |
866 | r = PTR_ERR(pg); | |
1da177e4 LT |
867 | goto bad; |
868 | } | |
869 | ||
870 | m->nr_valid_paths += pg->nr_pgpaths; | |
871 | list_add_tail(&pg->list, &m->priority_groups); | |
872 | pg_count++; | |
873 | pg->pg_num = pg_count; | |
874 | if (!--next_pg_num) | |
875 | m->next_pg = pg; | |
876 | } | |
877 | ||
878 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 879 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
880 | r = -EINVAL; |
881 | goto bad; | |
882 | } | |
883 | ||
8627921f | 884 | ti->num_flush_requests = 1; |
959eb4e5 | 885 | ti->num_discard_requests = 1; |
8627921f | 886 | |
1da177e4 LT |
887 | return 0; |
888 | ||
889 | bad: | |
890 | free_multipath(m); | |
891 | return r; | |
892 | } | |
893 | ||
2bded7bd KU |
894 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
895 | { | |
896 | DECLARE_WAITQUEUE(wait, current); | |
897 | unsigned long flags; | |
898 | ||
899 | add_wait_queue(&m->pg_init_wait, &wait); | |
900 | ||
901 | while (1) { | |
902 | set_current_state(TASK_UNINTERRUPTIBLE); | |
903 | ||
904 | spin_lock_irqsave(&m->lock, flags); | |
905 | if (!m->pg_init_in_progress) { | |
906 | spin_unlock_irqrestore(&m->lock, flags); | |
907 | break; | |
908 | } | |
909 | spin_unlock_irqrestore(&m->lock, flags); | |
910 | ||
911 | io_schedule(); | |
912 | } | |
913 | set_current_state(TASK_RUNNING); | |
914 | ||
915 | remove_wait_queue(&m->pg_init_wait, &wait); | |
916 | } | |
917 | ||
918 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 919 | { |
bab7cfc7 | 920 | flush_workqueue(kmpath_handlerd); |
2bded7bd | 921 | multipath_wait_for_pg_init_completion(m); |
a044d016 | 922 | flush_workqueue(kmultipathd); |
d5ffa387 | 923 | flush_work_sync(&m->trigger_event); |
6df400ab KU |
924 | } |
925 | ||
926 | static void multipath_dtr(struct dm_target *ti) | |
927 | { | |
928 | struct multipath *m = ti->private; | |
929 | ||
2bded7bd | 930 | flush_multipath_work(m); |
1da177e4 LT |
931 | free_multipath(m); |
932 | } | |
933 | ||
934 | /* | |
f40c67f0 | 935 | * Map cloned requests |
1da177e4 | 936 | */ |
f40c67f0 | 937 | static int multipath_map(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
938 | union map_info *map_context) |
939 | { | |
940 | int r; | |
028867ac | 941 | struct dm_mpath_io *mpio; |
1da177e4 LT |
942 | struct multipath *m = (struct multipath *) ti->private; |
943 | ||
f40c67f0 KU |
944 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); |
945 | if (!mpio) | |
946 | /* ENOMEM, requeue */ | |
947 | return DM_MAPIO_REQUEUE; | |
948 | memset(mpio, 0, sizeof(*mpio)); | |
1da177e4 LT |
949 | |
950 | map_context->ptr = mpio; | |
f40c67f0 KU |
951 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
952 | r = map_io(m, clone, mpio, 0); | |
45e15720 | 953 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
1da177e4 LT |
954 | mempool_free(mpio, m->mpio_pool); |
955 | ||
956 | return r; | |
957 | } | |
958 | ||
959 | /* | |
960 | * Take a path out of use. | |
961 | */ | |
962 | static int fail_path(struct pgpath *pgpath) | |
963 | { | |
964 | unsigned long flags; | |
965 | struct multipath *m = pgpath->pg->m; | |
966 | ||
967 | spin_lock_irqsave(&m->lock, flags); | |
968 | ||
6680073d | 969 | if (!pgpath->is_active) |
1da177e4 LT |
970 | goto out; |
971 | ||
72d94861 | 972 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
973 | |
974 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
6680073d | 975 | pgpath->is_active = 0; |
1da177e4 LT |
976 | pgpath->fail_count++; |
977 | ||
978 | m->nr_valid_paths--; | |
979 | ||
980 | if (pgpath == m->current_pgpath) | |
981 | m->current_pgpath = NULL; | |
982 | ||
b15546f9 MA |
983 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
984 | pgpath->path.dev->name, m->nr_valid_paths); | |
985 | ||
fe9cf30e | 986 | schedule_work(&m->trigger_event); |
1da177e4 LT |
987 | |
988 | out: | |
989 | spin_unlock_irqrestore(&m->lock, flags); | |
990 | ||
991 | return 0; | |
992 | } | |
993 | ||
994 | /* | |
995 | * Reinstate a previously-failed path | |
996 | */ | |
997 | static int reinstate_path(struct pgpath *pgpath) | |
998 | { | |
999 | int r = 0; | |
1000 | unsigned long flags; | |
1001 | struct multipath *m = pgpath->pg->m; | |
1002 | ||
1003 | spin_lock_irqsave(&m->lock, flags); | |
1004 | ||
6680073d | 1005 | if (pgpath->is_active) |
1da177e4 LT |
1006 | goto out; |
1007 | ||
def052d2 | 1008 | if (!pgpath->pg->ps.type->reinstate_path) { |
1da177e4 LT |
1009 | DMWARN("Reinstate path not supported by path selector %s", |
1010 | pgpath->pg->ps.type->name); | |
1011 | r = -EINVAL; | |
1012 | goto out; | |
1013 | } | |
1014 | ||
1015 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1016 | if (r) | |
1017 | goto out; | |
1018 | ||
6680073d | 1019 | pgpath->is_active = 1; |
1da177e4 | 1020 | |
e54f77dd CS |
1021 | if (!m->nr_valid_paths++ && m->queue_size) { |
1022 | m->current_pgpath = NULL; | |
c557308e | 1023 | queue_work(kmultipathd, &m->process_queued_ios); |
e54f77dd CS |
1024 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
1025 | if (queue_work(kmpath_handlerd, &pgpath->activate_path)) | |
1026 | m->pg_init_in_progress++; | |
1027 | } | |
1da177e4 | 1028 | |
b15546f9 MA |
1029 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
1030 | pgpath->path.dev->name, m->nr_valid_paths); | |
1031 | ||
fe9cf30e | 1032 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1033 | |
1034 | out: | |
1035 | spin_unlock_irqrestore(&m->lock, flags); | |
1036 | ||
1037 | return r; | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1042 | */ | |
1043 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1044 | action_fn action) | |
1045 | { | |
1046 | int r = 0; | |
1047 | struct pgpath *pgpath; | |
1048 | struct priority_group *pg; | |
1049 | ||
1050 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1051 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1052 | if (pgpath->path.dev == dev) | |
1053 | r = action(pgpath); | |
1054 | } | |
1055 | } | |
1056 | ||
1057 | return r; | |
1058 | } | |
1059 | ||
1060 | /* | |
1061 | * Temporarily try to avoid having to use the specified PG | |
1062 | */ | |
1063 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
1064 | int bypassed) | |
1065 | { | |
1066 | unsigned long flags; | |
1067 | ||
1068 | spin_lock_irqsave(&m->lock, flags); | |
1069 | ||
1070 | pg->bypassed = bypassed; | |
1071 | m->current_pgpath = NULL; | |
1072 | m->current_pg = NULL; | |
1073 | ||
1074 | spin_unlock_irqrestore(&m->lock, flags); | |
1075 | ||
fe9cf30e | 1076 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1077 | } |
1078 | ||
1079 | /* | |
1080 | * Switch to using the specified PG from the next I/O that gets mapped | |
1081 | */ | |
1082 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1083 | { | |
1084 | struct priority_group *pg; | |
1085 | unsigned pgnum; | |
1086 | unsigned long flags; | |
1087 | ||
1088 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
1089 | (pgnum > m->nr_priority_groups)) { | |
1090 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
1091 | return -EINVAL; | |
1092 | } | |
1093 | ||
1094 | spin_lock_irqsave(&m->lock, flags); | |
1095 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1096 | pg->bypassed = 0; | |
1097 | if (--pgnum) | |
1098 | continue; | |
1099 | ||
1100 | m->current_pgpath = NULL; | |
1101 | m->current_pg = NULL; | |
1102 | m->next_pg = pg; | |
1103 | } | |
1104 | spin_unlock_irqrestore(&m->lock, flags); | |
1105 | ||
fe9cf30e | 1106 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1107 | return 0; |
1108 | } | |
1109 | ||
1110 | /* | |
1111 | * Set/clear bypassed status of a PG. | |
1112 | * PGs are numbered upwards from 1 in the order they were declared. | |
1113 | */ | |
1114 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
1115 | { | |
1116 | struct priority_group *pg; | |
1117 | unsigned pgnum; | |
1118 | ||
1119 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
1120 | (pgnum > m->nr_priority_groups)) { | |
1121 | DMWARN("invalid PG number supplied to bypass_pg"); | |
1122 | return -EINVAL; | |
1123 | } | |
1124 | ||
1125 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1126 | if (!--pgnum) | |
1127 | break; | |
1128 | } | |
1129 | ||
1130 | bypass_pg(m, pg, bypassed); | |
1131 | return 0; | |
1132 | } | |
1133 | ||
c9e45581 DW |
1134 | /* |
1135 | * Should we retry pg_init immediately? | |
1136 | */ | |
1137 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1138 | { | |
1139 | unsigned long flags; | |
1140 | int limit_reached = 0; | |
1141 | ||
1142 | spin_lock_irqsave(&m->lock, flags); | |
1143 | ||
1144 | if (m->pg_init_count <= m->pg_init_retries) | |
1145 | m->pg_init_required = 1; | |
1146 | else | |
1147 | limit_reached = 1; | |
1148 | ||
1149 | spin_unlock_irqrestore(&m->lock, flags); | |
1150 | ||
1151 | return limit_reached; | |
1152 | } | |
1153 | ||
3ae31f6a | 1154 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1155 | { |
83c0d5d5 | 1156 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1157 | struct priority_group *pg = pgpath->pg; |
1158 | struct multipath *m = pg->m; | |
1159 | unsigned long flags; | |
1160 | ||
1161 | /* device or driver problems */ | |
1162 | switch (errors) { | |
1163 | case SCSI_DH_OK: | |
1164 | break; | |
1165 | case SCSI_DH_NOSYS: | |
1166 | if (!m->hw_handler_name) { | |
1167 | errors = 0; | |
1168 | break; | |
1169 | } | |
f7b934c8 MB |
1170 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1171 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1172 | /* |
1173 | * Fail path for now, so we do not ping pong | |
1174 | */ | |
1175 | fail_path(pgpath); | |
1176 | break; | |
1177 | case SCSI_DH_DEV_TEMP_BUSY: | |
1178 | /* | |
1179 | * Probably doing something like FW upgrade on the | |
1180 | * controller so try the other pg. | |
1181 | */ | |
1182 | bypass_pg(m, pg, 1); | |
1183 | break; | |
1184 | /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */ | |
1185 | case SCSI_DH_RETRY: | |
1186 | case SCSI_DH_IMM_RETRY: | |
1187 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1188 | if (pg_init_limit_reached(m, pgpath)) | |
1189 | fail_path(pgpath); | |
1190 | errors = 0; | |
1191 | break; | |
1192 | default: | |
1193 | /* | |
1194 | * We probably do not want to fail the path for a device | |
1195 | * error, but this is what the old dm did. In future | |
1196 | * patches we can do more advanced handling. | |
1197 | */ | |
1198 | fail_path(pgpath); | |
1199 | } | |
1200 | ||
1201 | spin_lock_irqsave(&m->lock, flags); | |
1202 | if (errors) { | |
e54f77dd CS |
1203 | if (pgpath == m->current_pgpath) { |
1204 | DMERR("Could not failover device. Error %d.", errors); | |
1205 | m->current_pgpath = NULL; | |
1206 | m->current_pg = NULL; | |
1207 | } | |
d0259bf0 | 1208 | } else if (!m->pg_init_required) |
cfae5c9b | 1209 | pg->bypassed = 0; |
cfae5c9b | 1210 | |
d0259bf0 KU |
1211 | if (--m->pg_init_in_progress) |
1212 | /* Activations of other paths are still on going */ | |
1213 | goto out; | |
1214 | ||
1215 | if (!m->pg_init_required) | |
1216 | m->queue_io = 0; | |
1217 | ||
1218 | queue_work(kmultipathd, &m->process_queued_ios); | |
1219 | ||
2bded7bd KU |
1220 | /* |
1221 | * Wake up any thread waiting to suspend. | |
1222 | */ | |
1223 | wake_up(&m->pg_init_wait); | |
1224 | ||
d0259bf0 | 1225 | out: |
cfae5c9b CS |
1226 | spin_unlock_irqrestore(&m->lock, flags); |
1227 | } | |
1228 | ||
bab7cfc7 CS |
1229 | static void activate_path(struct work_struct *work) |
1230 | { | |
e54f77dd CS |
1231 | struct pgpath *pgpath = |
1232 | container_of(work, struct pgpath, activate_path); | |
bab7cfc7 | 1233 | |
3ae31f6a | 1234 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), |
83c0d5d5 | 1235 | pg_init_done, pgpath); |
bab7cfc7 CS |
1236 | } |
1237 | ||
1da177e4 LT |
1238 | /* |
1239 | * end_io handling | |
1240 | */ | |
f40c67f0 | 1241 | static int do_end_io(struct multipath *m, struct request *clone, |
028867ac | 1242 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1243 | { |
f40c67f0 KU |
1244 | /* |
1245 | * We don't queue any clone request inside the multipath target | |
1246 | * during end I/O handling, since those clone requests don't have | |
1247 | * bio clones. If we queue them inside the multipath target, | |
1248 | * we need to make bio clones, that requires memory allocation. | |
1249 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests | |
1250 | * don't have bio clones.) | |
1251 | * Instead of queueing the clone request here, we queue the original | |
1252 | * request into dm core, which will remake a clone request and | |
1253 | * clone bios for it and resubmit it later. | |
1254 | */ | |
1255 | int r = DM_ENDIO_REQUEUE; | |
640eb3b0 | 1256 | unsigned long flags; |
1da177e4 | 1257 | |
f40c67f0 | 1258 | if (!error && !clone->errors) |
1da177e4 LT |
1259 | return 0; /* I/O complete */ |
1260 | ||
f6a80ea8 AK |
1261 | if (error == -EOPNOTSUPP) |
1262 | return error; | |
1263 | ||
959eb4e5 MS |
1264 | if (clone->cmd_flags & REQ_DISCARD) |
1265 | /* | |
1266 | * Pass all discard request failures up. | |
1267 | * FIXME: only fail_path if the discard failed due to a | |
1268 | * transport problem. This requires precise understanding | |
1269 | * of the underlying failure (e.g. the SCSI sense). | |
1270 | */ | |
1271 | return error; | |
1272 | ||
cfae5c9b CS |
1273 | if (mpio->pgpath) |
1274 | fail_path(mpio->pgpath); | |
1da177e4 | 1275 | |
640eb3b0 | 1276 | spin_lock_irqsave(&m->lock, flags); |
f40c67f0 KU |
1277 | if (!m->nr_valid_paths && !m->queue_if_no_path && !__must_push_back(m)) |
1278 | r = -EIO; | |
640eb3b0 | 1279 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1280 | |
f40c67f0 | 1281 | return r; |
1da177e4 LT |
1282 | } |
1283 | ||
f40c67f0 | 1284 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
1285 | int error, union map_info *map_context) |
1286 | { | |
028867ac AK |
1287 | struct multipath *m = ti->private; |
1288 | struct dm_mpath_io *mpio = map_context->ptr; | |
1da177e4 LT |
1289 | struct pgpath *pgpath = mpio->pgpath; |
1290 | struct path_selector *ps; | |
1291 | int r; | |
1292 | ||
f40c67f0 | 1293 | r = do_end_io(m, clone, error, mpio); |
1da177e4 LT |
1294 | if (pgpath) { |
1295 | ps = &pgpath->pg->ps; | |
1296 | if (ps->type->end_io) | |
02ab823f | 1297 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
1da177e4 | 1298 | } |
f40c67f0 | 1299 | mempool_free(mpio, m->mpio_pool); |
1da177e4 LT |
1300 | |
1301 | return r; | |
1302 | } | |
1303 | ||
1304 | /* | |
1305 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1306 | * the last path fails we must error any remaining I/O. |
1307 | * Note that if the freeze_bdev fails while suspending, the | |
1308 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1309 | */ |
1310 | static void multipath_presuspend(struct dm_target *ti) | |
1311 | { | |
1312 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1313 | |
485ef69e | 1314 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1315 | } |
1316 | ||
6df400ab KU |
1317 | static void multipath_postsuspend(struct dm_target *ti) |
1318 | { | |
6380f26f MA |
1319 | struct multipath *m = ti->private; |
1320 | ||
1321 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1322 | flush_multipath_work(m); |
6380f26f | 1323 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1324 | } |
1325 | ||
436d4108 AK |
1326 | /* |
1327 | * Restore the queue_if_no_path setting. | |
1328 | */ | |
1da177e4 LT |
1329 | static void multipath_resume(struct dm_target *ti) |
1330 | { | |
1331 | struct multipath *m = (struct multipath *) ti->private; | |
1332 | unsigned long flags; | |
1333 | ||
1334 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1335 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1336 | spin_unlock_irqrestore(&m->lock, flags); |
1337 | } | |
1338 | ||
1339 | /* | |
1340 | * Info output has the following format: | |
1341 | * num_multipath_feature_args [multipath_feature_args]* | |
1342 | * num_handler_status_args [handler_status_args]* | |
1343 | * num_groups init_group_number | |
1344 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1345 | * num_paths num_selector_args | |
1346 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1347 | * | |
1348 | * Table output has the following format (identical to the constructor string): | |
1349 | * num_feature_args [features_args]* | |
1350 | * num_handler_args hw_handler [hw_handler_args]* | |
1351 | * num_groups init_group_number | |
1352 | * [priority selector-name num_ps_args [ps_args]* | |
1353 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1354 | */ | |
1355 | static int multipath_status(struct dm_target *ti, status_type_t type, | |
1356 | char *result, unsigned int maxlen) | |
1357 | { | |
1358 | int sz = 0; | |
1359 | unsigned long flags; | |
1360 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1361 | struct priority_group *pg; |
1362 | struct pgpath *p; | |
1363 | unsigned pg_num; | |
1364 | char state; | |
1365 | ||
1366 | spin_lock_irqsave(&m->lock, flags); | |
1367 | ||
1368 | /* Features */ | |
1369 | if (type == STATUSTYPE_INFO) | |
c9e45581 DW |
1370 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
1371 | else { | |
1372 | DMEMIT("%u ", m->queue_if_no_path + | |
1373 | (m->pg_init_retries > 0) * 2); | |
1374 | if (m->queue_if_no_path) | |
1375 | DMEMIT("queue_if_no_path "); | |
1376 | if (m->pg_init_retries) | |
1377 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
1378 | } | |
1da177e4 | 1379 | |
cfae5c9b | 1380 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1381 | DMEMIT("0 "); |
1382 | else | |
cfae5c9b | 1383 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1384 | |
1385 | DMEMIT("%u ", m->nr_priority_groups); | |
1386 | ||
1387 | if (m->next_pg) | |
1388 | pg_num = m->next_pg->pg_num; | |
1389 | else if (m->current_pg) | |
1390 | pg_num = m->current_pg->pg_num; | |
1391 | else | |
1392 | pg_num = 1; | |
1393 | ||
1394 | DMEMIT("%u ", pg_num); | |
1395 | ||
1396 | switch (type) { | |
1397 | case STATUSTYPE_INFO: | |
1398 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1399 | if (pg->bypassed) | |
1400 | state = 'D'; /* Disabled */ | |
1401 | else if (pg == m->current_pg) | |
1402 | state = 'A'; /* Currently Active */ | |
1403 | else | |
1404 | state = 'E'; /* Enabled */ | |
1405 | ||
1406 | DMEMIT("%c ", state); | |
1407 | ||
1408 | if (pg->ps.type->status) | |
1409 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1410 | result + sz, | |
1411 | maxlen - sz); | |
1412 | else | |
1413 | DMEMIT("0 "); | |
1414 | ||
1415 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1416 | pg->ps.type->info_args); | |
1417 | ||
1418 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1419 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1420 | p->is_active ? "A" : "F", |
1da177e4 LT |
1421 | p->fail_count); |
1422 | if (pg->ps.type->status) | |
1423 | sz += pg->ps.type->status(&pg->ps, | |
1424 | &p->path, type, result + sz, | |
1425 | maxlen - sz); | |
1426 | } | |
1427 | } | |
1428 | break; | |
1429 | ||
1430 | case STATUSTYPE_TABLE: | |
1431 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1432 | DMEMIT("%s ", pg->ps.type->name); | |
1433 | ||
1434 | if (pg->ps.type->status) | |
1435 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1436 | result + sz, | |
1437 | maxlen - sz); | |
1438 | else | |
1439 | DMEMIT("0 "); | |
1440 | ||
1441 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1442 | pg->ps.type->table_args); | |
1443 | ||
1444 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1445 | DMEMIT("%s ", p->path.dev->name); | |
1446 | if (pg->ps.type->status) | |
1447 | sz += pg->ps.type->status(&pg->ps, | |
1448 | &p->path, type, result + sz, | |
1449 | maxlen - sz); | |
1450 | } | |
1451 | } | |
1452 | break; | |
1453 | } | |
1454 | ||
1455 | spin_unlock_irqrestore(&m->lock, flags); | |
1456 | ||
1457 | return 0; | |
1458 | } | |
1459 | ||
1460 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1461 | { | |
6380f26f | 1462 | int r = -EINVAL; |
1da177e4 LT |
1463 | struct dm_dev *dev; |
1464 | struct multipath *m = (struct multipath *) ti->private; | |
1465 | action_fn action; | |
1466 | ||
6380f26f MA |
1467 | mutex_lock(&m->work_mutex); |
1468 | ||
c2f3d24b KU |
1469 | if (dm_suspended(ti)) { |
1470 | r = -EBUSY; | |
1471 | goto out; | |
1472 | } | |
1473 | ||
1da177e4 | 1474 | if (argc == 1) { |
6380f26f MA |
1475 | if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) { |
1476 | r = queue_if_no_path(m, 1, 0); | |
1477 | goto out; | |
1478 | } else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) { | |
1479 | r = queue_if_no_path(m, 0, 0); | |
1480 | goto out; | |
1481 | } | |
1da177e4 LT |
1482 | } |
1483 | ||
6380f26f MA |
1484 | if (argc != 2) { |
1485 | DMWARN("Unrecognised multipath message received."); | |
1486 | goto out; | |
1487 | } | |
1da177e4 | 1488 | |
6380f26f MA |
1489 | if (!strnicmp(argv[0], MESG_STR("disable_group"))) { |
1490 | r = bypass_pg_num(m, argv[1], 1); | |
1491 | goto out; | |
1492 | } else if (!strnicmp(argv[0], MESG_STR("enable_group"))) { | |
1493 | r = bypass_pg_num(m, argv[1], 0); | |
1494 | goto out; | |
1495 | } else if (!strnicmp(argv[0], MESG_STR("switch_group"))) { | |
1496 | r = switch_pg_num(m, argv[1]); | |
1497 | goto out; | |
1498 | } else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) | |
1da177e4 LT |
1499 | action = reinstate_path; |
1500 | else if (!strnicmp(argv[0], MESG_STR("fail_path"))) | |
1501 | action = fail_path; | |
6380f26f MA |
1502 | else { |
1503 | DMWARN("Unrecognised multipath message received."); | |
1504 | goto out; | |
1505 | } | |
1da177e4 | 1506 | |
8215d6ec | 1507 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 1508 | if (r) { |
72d94861 | 1509 | DMWARN("message: error getting device %s", |
1da177e4 | 1510 | argv[1]); |
6380f26f | 1511 | goto out; |
1da177e4 LT |
1512 | } |
1513 | ||
1514 | r = action_dev(m, dev, action); | |
1515 | ||
1516 | dm_put_device(ti, dev); | |
1517 | ||
6380f26f MA |
1518 | out: |
1519 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 1520 | return r; |
1da177e4 LT |
1521 | } |
1522 | ||
647b3d00 | 1523 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
9af4aa30 MB |
1524 | unsigned long arg) |
1525 | { | |
1526 | struct multipath *m = (struct multipath *) ti->private; | |
1527 | struct block_device *bdev = NULL; | |
633a08b8 | 1528 | fmode_t mode = 0; |
9af4aa30 MB |
1529 | unsigned long flags; |
1530 | int r = 0; | |
1531 | ||
1532 | spin_lock_irqsave(&m->lock, flags); | |
1533 | ||
1534 | if (!m->current_pgpath) | |
02ab823f | 1535 | __choose_pgpath(m, 0); |
9af4aa30 | 1536 | |
e90dae1f | 1537 | if (m->current_pgpath) { |
9af4aa30 | 1538 | bdev = m->current_pgpath->path.dev->bdev; |
633a08b8 | 1539 | mode = m->current_pgpath->path.dev->mode; |
e90dae1f | 1540 | } |
9af4aa30 MB |
1541 | |
1542 | if (m->queue_io) | |
1543 | r = -EAGAIN; | |
1544 | else if (!bdev) | |
1545 | r = -EIO; | |
1546 | ||
1547 | spin_unlock_irqrestore(&m->lock, flags); | |
1548 | ||
633a08b8 | 1549 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
9af4aa30 MB |
1550 | } |
1551 | ||
af4874e0 MS |
1552 | static int multipath_iterate_devices(struct dm_target *ti, |
1553 | iterate_devices_callout_fn fn, void *data) | |
1554 | { | |
1555 | struct multipath *m = ti->private; | |
1556 | struct priority_group *pg; | |
1557 | struct pgpath *p; | |
1558 | int ret = 0; | |
1559 | ||
1560 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1561 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 1562 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
1563 | if (ret) |
1564 | goto out; | |
1565 | } | |
1566 | } | |
1567 | ||
1568 | out: | |
1569 | return ret; | |
1570 | } | |
1571 | ||
f40c67f0 KU |
1572 | static int __pgpath_busy(struct pgpath *pgpath) |
1573 | { | |
1574 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
1575 | ||
1576 | return dm_underlying_device_busy(q); | |
1577 | } | |
1578 | ||
1579 | /* | |
1580 | * We return "busy", only when we can map I/Os but underlying devices | |
1581 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
1582 | * the underlying queue). | |
1583 | * In other words, if we want to kill I/Os or queue them inside us | |
1584 | * due to map unavailability, we don't return "busy". Otherwise, | |
1585 | * dm core won't give us the I/Os and we can't do what we want. | |
1586 | */ | |
1587 | static int multipath_busy(struct dm_target *ti) | |
1588 | { | |
1589 | int busy = 0, has_active = 0; | |
1590 | struct multipath *m = ti->private; | |
1591 | struct priority_group *pg; | |
1592 | struct pgpath *pgpath; | |
1593 | unsigned long flags; | |
1594 | ||
1595 | spin_lock_irqsave(&m->lock, flags); | |
1596 | ||
1597 | /* Guess which priority_group will be used at next mapping time */ | |
1598 | if (unlikely(!m->current_pgpath && m->next_pg)) | |
1599 | pg = m->next_pg; | |
1600 | else if (likely(m->current_pg)) | |
1601 | pg = m->current_pg; | |
1602 | else | |
1603 | /* | |
1604 | * We don't know which pg will be used at next mapping time. | |
1605 | * We don't call __choose_pgpath() here to avoid to trigger | |
1606 | * pg_init just by busy checking. | |
1607 | * So we don't know whether underlying devices we will be using | |
1608 | * at next mapping time are busy or not. Just try mapping. | |
1609 | */ | |
1610 | goto out; | |
1611 | ||
1612 | /* | |
1613 | * If there is one non-busy active path at least, the path selector | |
1614 | * will be able to select it. So we consider such a pg as not busy. | |
1615 | */ | |
1616 | busy = 1; | |
1617 | list_for_each_entry(pgpath, &pg->pgpaths, list) | |
1618 | if (pgpath->is_active) { | |
1619 | has_active = 1; | |
1620 | ||
1621 | if (!__pgpath_busy(pgpath)) { | |
1622 | busy = 0; | |
1623 | break; | |
1624 | } | |
1625 | } | |
1626 | ||
1627 | if (!has_active) | |
1628 | /* | |
1629 | * No active path in this pg, so this pg won't be used and | |
1630 | * the current_pg will be changed at next mapping time. | |
1631 | * We need to try mapping to determine it. | |
1632 | */ | |
1633 | busy = 0; | |
1634 | ||
1635 | out: | |
1636 | spin_unlock_irqrestore(&m->lock, flags); | |
1637 | ||
1638 | return busy; | |
1639 | } | |
1640 | ||
1da177e4 LT |
1641 | /*----------------------------------------------------------------- |
1642 | * Module setup | |
1643 | *---------------------------------------------------------------*/ | |
1644 | static struct target_type multipath_target = { | |
1645 | .name = "multipath", | |
6df400ab | 1646 | .version = {1, 1, 1}, |
1da177e4 LT |
1647 | .module = THIS_MODULE, |
1648 | .ctr = multipath_ctr, | |
1649 | .dtr = multipath_dtr, | |
f40c67f0 KU |
1650 | .map_rq = multipath_map, |
1651 | .rq_end_io = multipath_end_io, | |
1da177e4 | 1652 | .presuspend = multipath_presuspend, |
6df400ab | 1653 | .postsuspend = multipath_postsuspend, |
1da177e4 LT |
1654 | .resume = multipath_resume, |
1655 | .status = multipath_status, | |
1656 | .message = multipath_message, | |
9af4aa30 | 1657 | .ioctl = multipath_ioctl, |
af4874e0 | 1658 | .iterate_devices = multipath_iterate_devices, |
f40c67f0 | 1659 | .busy = multipath_busy, |
1da177e4 LT |
1660 | }; |
1661 | ||
1662 | static int __init dm_multipath_init(void) | |
1663 | { | |
1664 | int r; | |
1665 | ||
1666 | /* allocate a slab for the dm_ios */ | |
028867ac | 1667 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1668 | if (!_mpio_cache) |
1669 | return -ENOMEM; | |
1670 | ||
1671 | r = dm_register_target(&multipath_target); | |
1672 | if (r < 0) { | |
0cd33124 | 1673 | DMERR("register failed %d", r); |
1da177e4 LT |
1674 | kmem_cache_destroy(_mpio_cache); |
1675 | return -EINVAL; | |
1676 | } | |
1677 | ||
c557308e AK |
1678 | kmultipathd = create_workqueue("kmpathd"); |
1679 | if (!kmultipathd) { | |
0cd33124 | 1680 | DMERR("failed to create workqueue kmpathd"); |
c557308e AK |
1681 | dm_unregister_target(&multipath_target); |
1682 | kmem_cache_destroy(_mpio_cache); | |
1683 | return -ENOMEM; | |
1684 | } | |
1685 | ||
bab7cfc7 CS |
1686 | /* |
1687 | * A separate workqueue is used to handle the device handlers | |
1688 | * to avoid overloading existing workqueue. Overloading the | |
1689 | * old workqueue would also create a bottleneck in the | |
1690 | * path of the storage hardware device activation. | |
1691 | */ | |
1692 | kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd"); | |
1693 | if (!kmpath_handlerd) { | |
1694 | DMERR("failed to create workqueue kmpath_handlerd"); | |
1695 | destroy_workqueue(kmultipathd); | |
1696 | dm_unregister_target(&multipath_target); | |
1697 | kmem_cache_destroy(_mpio_cache); | |
1698 | return -ENOMEM; | |
1699 | } | |
1700 | ||
72d94861 | 1701 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1702 | multipath_target.version[0], multipath_target.version[1], |
1703 | multipath_target.version[2]); | |
1704 | ||
1705 | return r; | |
1706 | } | |
1707 | ||
1708 | static void __exit dm_multipath_exit(void) | |
1709 | { | |
bab7cfc7 | 1710 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1711 | destroy_workqueue(kmultipathd); |
1712 | ||
10d3bd09 | 1713 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
1714 | kmem_cache_destroy(_mpio_cache); |
1715 | } | |
1716 | ||
1da177e4 LT |
1717 | module_init(dm_multipath_init); |
1718 | module_exit(dm_multipath_exit); | |
1719 | ||
1720 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1721 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1722 | MODULE_LICENSE("GPL"); |