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 | ||
8 | #include "dm.h" | |
9 | #include "dm-path-selector.h" | |
10 | #include "dm-hw-handler.h" | |
11 | #include "dm-bio-list.h" | |
12 | #include "dm-bio-record.h" | |
b15546f9 | 13 | #include "dm-uevent.h" |
1da177e4 LT |
14 | |
15 | #include <linux/ctype.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/mempool.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/pagemap.h> | |
20 | #include <linux/slab.h> | |
21 | #include <linux/time.h> | |
22 | #include <linux/workqueue.h> | |
23 | #include <asm/atomic.h> | |
24 | ||
72d94861 | 25 | #define DM_MSG_PREFIX "multipath" |
1da177e4 LT |
26 | #define MESG_STR(x) x, sizeof(x) |
27 | ||
28 | /* Path properties */ | |
29 | struct pgpath { | |
30 | struct list_head list; | |
31 | ||
32 | struct priority_group *pg; /* Owning PG */ | |
33 | unsigned fail_count; /* Cumulative failure count */ | |
34 | ||
c922d5f7 | 35 | struct dm_path path; |
1da177e4 LT |
36 | }; |
37 | ||
38 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
39 | ||
40 | /* | |
41 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
42 | * Each has a path selector which controls which path gets used. | |
43 | */ | |
44 | struct priority_group { | |
45 | struct list_head list; | |
46 | ||
47 | struct multipath *m; /* Owning multipath instance */ | |
48 | struct path_selector ps; | |
49 | ||
50 | unsigned pg_num; /* Reference number */ | |
51 | unsigned bypassed; /* Temporarily bypass this PG? */ | |
52 | ||
53 | unsigned nr_pgpaths; /* Number of paths in PG */ | |
54 | struct list_head pgpaths; | |
55 | }; | |
56 | ||
57 | /* Multipath context */ | |
58 | struct multipath { | |
59 | struct list_head list; | |
60 | struct dm_target *ti; | |
61 | ||
62 | spinlock_t lock; | |
63 | ||
64 | struct hw_handler hw_handler; | |
65 | unsigned nr_priority_groups; | |
66 | struct list_head priority_groups; | |
67 | unsigned pg_init_required; /* pg_init needs calling? */ | |
c3cd4f6b | 68 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
1da177e4 LT |
69 | |
70 | unsigned nr_valid_paths; /* Total number of usable paths */ | |
71 | struct pgpath *current_pgpath; | |
72 | struct priority_group *current_pg; | |
73 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
74 | unsigned repeat_count; /* I/Os left before calling PS again */ | |
75 | ||
76 | unsigned queue_io; /* Must we queue all I/O? */ | |
77 | unsigned queue_if_no_path; /* Queue I/O if last path fails? */ | |
436d4108 | 78 | unsigned saved_queue_if_no_path;/* Saved state during suspension */ |
c9e45581 DW |
79 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
80 | unsigned pg_init_count; /* Number of times pg_init called */ | |
1da177e4 LT |
81 | |
82 | struct work_struct process_queued_ios; | |
83 | struct bio_list queued_ios; | |
84 | unsigned queue_size; | |
85 | ||
86 | struct work_struct trigger_event; | |
87 | ||
88 | /* | |
028867ac | 89 | * We must use a mempool of dm_mpath_io structs so that we |
1da177e4 LT |
90 | * can resubmit bios on error. |
91 | */ | |
92 | mempool_t *mpio_pool; | |
93 | }; | |
94 | ||
95 | /* | |
96 | * Context information attached to each bio we process. | |
97 | */ | |
028867ac | 98 | struct dm_mpath_io { |
1da177e4 LT |
99 | struct pgpath *pgpath; |
100 | struct dm_bio_details details; | |
101 | }; | |
102 | ||
103 | typedef int (*action_fn) (struct pgpath *pgpath); | |
104 | ||
105 | #define MIN_IOS 256 /* Mempool size */ | |
106 | ||
e18b890b | 107 | static struct kmem_cache *_mpio_cache; |
1da177e4 | 108 | |
009cd090 | 109 | static struct workqueue_struct *kmultipathd; |
c4028958 DH |
110 | static void process_queued_ios(struct work_struct *work); |
111 | static void trigger_event(struct work_struct *work); | |
1da177e4 LT |
112 | |
113 | ||
114 | /*----------------------------------------------- | |
115 | * Allocation routines | |
116 | *-----------------------------------------------*/ | |
117 | ||
118 | static struct pgpath *alloc_pgpath(void) | |
119 | { | |
e69fae56 | 120 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 121 | |
e69fae56 | 122 | if (pgpath) |
1da177e4 | 123 | pgpath->path.is_active = 1; |
1da177e4 LT |
124 | |
125 | return pgpath; | |
126 | } | |
127 | ||
028867ac | 128 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
129 | { |
130 | kfree(pgpath); | |
131 | } | |
132 | ||
133 | static struct priority_group *alloc_priority_group(void) | |
134 | { | |
135 | struct priority_group *pg; | |
136 | ||
e69fae56 | 137 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 138 | |
e69fae56 MM |
139 | if (pg) |
140 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
141 | |
142 | return pg; | |
143 | } | |
144 | ||
145 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
146 | { | |
147 | struct pgpath *pgpath, *tmp; | |
148 | ||
149 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
150 | list_del(&pgpath->list); | |
151 | dm_put_device(ti, pgpath->path.dev); | |
152 | free_pgpath(pgpath); | |
153 | } | |
154 | } | |
155 | ||
156 | static void free_priority_group(struct priority_group *pg, | |
157 | struct dm_target *ti) | |
158 | { | |
159 | struct path_selector *ps = &pg->ps; | |
160 | ||
161 | if (ps->type) { | |
162 | ps->type->destroy(ps); | |
163 | dm_put_path_selector(ps->type); | |
164 | } | |
165 | ||
166 | free_pgpaths(&pg->pgpaths, ti); | |
167 | kfree(pg); | |
168 | } | |
169 | ||
28f16c20 | 170 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
171 | { |
172 | struct multipath *m; | |
173 | ||
e69fae56 | 174 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 175 | if (m) { |
1da177e4 LT |
176 | INIT_LIST_HEAD(&m->priority_groups); |
177 | spin_lock_init(&m->lock); | |
178 | m->queue_io = 1; | |
c4028958 DH |
179 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
180 | INIT_WORK(&m->trigger_event, trigger_event); | |
93d2341c | 181 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
1da177e4 LT |
182 | if (!m->mpio_pool) { |
183 | kfree(m); | |
184 | return NULL; | |
185 | } | |
28f16c20 MM |
186 | m->ti = ti; |
187 | ti->private = m; | |
1da177e4 LT |
188 | } |
189 | ||
190 | return m; | |
191 | } | |
192 | ||
193 | static void free_multipath(struct multipath *m) | |
194 | { | |
195 | struct priority_group *pg, *tmp; | |
196 | struct hw_handler *hwh = &m->hw_handler; | |
197 | ||
198 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
199 | list_del(&pg->list); | |
200 | free_priority_group(pg, m->ti); | |
201 | } | |
202 | ||
203 | if (hwh->type) { | |
204 | hwh->type->destroy(hwh); | |
205 | dm_put_hw_handler(hwh->type); | |
206 | } | |
207 | ||
208 | mempool_destroy(m->mpio_pool); | |
209 | kfree(m); | |
210 | } | |
211 | ||
212 | ||
213 | /*----------------------------------------------- | |
214 | * Path selection | |
215 | *-----------------------------------------------*/ | |
216 | ||
217 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) | |
218 | { | |
219 | struct hw_handler *hwh = &m->hw_handler; | |
220 | ||
221 | m->current_pg = pgpath->pg; | |
222 | ||
223 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
224 | if (hwh->type && hwh->type->pg_init) { | |
225 | m->pg_init_required = 1; | |
226 | m->queue_io = 1; | |
227 | } else { | |
228 | m->pg_init_required = 0; | |
229 | m->queue_io = 0; | |
230 | } | |
c9e45581 DW |
231 | |
232 | m->pg_init_count = 0; | |
1da177e4 LT |
233 | } |
234 | ||
235 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg) | |
236 | { | |
c922d5f7 | 237 | struct dm_path *path; |
1da177e4 LT |
238 | |
239 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count); | |
240 | if (!path) | |
241 | return -ENXIO; | |
242 | ||
243 | m->current_pgpath = path_to_pgpath(path); | |
244 | ||
245 | if (m->current_pg != pg) | |
246 | __switch_pg(m, m->current_pgpath); | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
251 | static void __choose_pgpath(struct multipath *m) | |
252 | { | |
253 | struct priority_group *pg; | |
254 | unsigned bypassed = 1; | |
255 | ||
256 | if (!m->nr_valid_paths) | |
257 | goto failed; | |
258 | ||
259 | /* Were we instructed to switch PG? */ | |
260 | if (m->next_pg) { | |
261 | pg = m->next_pg; | |
262 | m->next_pg = NULL; | |
263 | if (!__choose_path_in_pg(m, pg)) | |
264 | return; | |
265 | } | |
266 | ||
267 | /* Don't change PG until it has no remaining paths */ | |
268 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg)) | |
269 | return; | |
270 | ||
271 | /* | |
272 | * Loop through priority groups until we find a valid path. | |
273 | * First time we skip PGs marked 'bypassed'. | |
274 | * Second time we only try the ones we skipped. | |
275 | */ | |
276 | do { | |
277 | list_for_each_entry(pg, &m->priority_groups, list) { | |
278 | if (pg->bypassed == bypassed) | |
279 | continue; | |
280 | if (!__choose_path_in_pg(m, pg)) | |
281 | return; | |
282 | } | |
283 | } while (bypassed--); | |
284 | ||
285 | failed: | |
286 | m->current_pgpath = NULL; | |
287 | m->current_pg = NULL; | |
288 | } | |
289 | ||
45e15720 KU |
290 | /* |
291 | * Check whether bios must be queued in the device-mapper core rather | |
292 | * than here in the target. | |
293 | * | |
294 | * m->lock must be held on entry. | |
295 | * | |
296 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
297 | * same value then we are not between multipath_presuspend() | |
298 | * and multipath_resume() calls and we have no need to check | |
299 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
300 | */ | |
301 | static int __must_push_back(struct multipath *m) | |
302 | { | |
303 | return (m->queue_if_no_path != m->saved_queue_if_no_path && | |
304 | dm_noflush_suspending(m->ti)); | |
305 | } | |
306 | ||
028867ac AK |
307 | static int map_io(struct multipath *m, struct bio *bio, |
308 | struct dm_mpath_io *mpio, unsigned was_queued) | |
1da177e4 | 309 | { |
d2a7ad29 | 310 | int r = DM_MAPIO_REMAPPED; |
1da177e4 LT |
311 | unsigned long flags; |
312 | struct pgpath *pgpath; | |
313 | ||
314 | spin_lock_irqsave(&m->lock, flags); | |
315 | ||
316 | /* Do we need to select a new pgpath? */ | |
317 | if (!m->current_pgpath || | |
318 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
319 | __choose_pgpath(m); | |
320 | ||
321 | pgpath = m->current_pgpath; | |
322 | ||
323 | if (was_queued) | |
324 | m->queue_size--; | |
325 | ||
326 | if ((pgpath && m->queue_io) || | |
436d4108 | 327 | (!pgpath && m->queue_if_no_path)) { |
1da177e4 LT |
328 | /* Queue for the daemon to resubmit */ |
329 | bio_list_add(&m->queued_ios, bio); | |
330 | m->queue_size++; | |
c3cd4f6b AK |
331 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
332 | !m->queue_io) | |
c557308e | 333 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 334 | pgpath = NULL; |
d2a7ad29 | 335 | r = DM_MAPIO_SUBMITTED; |
45e15720 | 336 | } else if (pgpath) |
1da177e4 | 337 | bio->bi_bdev = pgpath->path.dev->bdev; |
45e15720 KU |
338 | else if (__must_push_back(m)) |
339 | r = DM_MAPIO_REQUEUE; | |
340 | else | |
341 | r = -EIO; /* Failed */ | |
1da177e4 LT |
342 | |
343 | mpio->pgpath = pgpath; | |
344 | ||
345 | spin_unlock_irqrestore(&m->lock, flags); | |
346 | ||
347 | return r; | |
348 | } | |
349 | ||
350 | /* | |
351 | * If we run out of usable paths, should we queue I/O or error it? | |
352 | */ | |
485ef69e AK |
353 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
354 | unsigned save_old_value) | |
1da177e4 LT |
355 | { |
356 | unsigned long flags; | |
357 | ||
358 | spin_lock_irqsave(&m->lock, flags); | |
359 | ||
485ef69e AK |
360 | if (save_old_value) |
361 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
362 | else | |
363 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 364 | m->queue_if_no_path = queue_if_no_path; |
c3cd4f6b | 365 | if (!m->queue_if_no_path && m->queue_size) |
c557308e | 366 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
367 | |
368 | spin_unlock_irqrestore(&m->lock, flags); | |
369 | ||
370 | return 0; | |
371 | } | |
372 | ||
373 | /*----------------------------------------------------------------- | |
374 | * The multipath daemon is responsible for resubmitting queued ios. | |
375 | *---------------------------------------------------------------*/ | |
376 | ||
377 | static void dispatch_queued_ios(struct multipath *m) | |
378 | { | |
379 | int r; | |
380 | unsigned long flags; | |
381 | struct bio *bio = NULL, *next; | |
028867ac | 382 | struct dm_mpath_io *mpio; |
1da177e4 LT |
383 | union map_info *info; |
384 | ||
385 | spin_lock_irqsave(&m->lock, flags); | |
386 | bio = bio_list_get(&m->queued_ios); | |
387 | spin_unlock_irqrestore(&m->lock, flags); | |
388 | ||
389 | while (bio) { | |
390 | next = bio->bi_next; | |
391 | bio->bi_next = NULL; | |
392 | ||
393 | info = dm_get_mapinfo(bio); | |
394 | mpio = info->ptr; | |
395 | ||
396 | r = map_io(m, bio, mpio, 1); | |
397 | if (r < 0) | |
6712ecf8 | 398 | bio_endio(bio, r); |
d2a7ad29 | 399 | else if (r == DM_MAPIO_REMAPPED) |
1da177e4 | 400 | generic_make_request(bio); |
45e15720 | 401 | else if (r == DM_MAPIO_REQUEUE) |
6712ecf8 | 402 | bio_endio(bio, -EIO); |
1da177e4 LT |
403 | |
404 | bio = next; | |
405 | } | |
406 | } | |
407 | ||
c4028958 | 408 | static void process_queued_ios(struct work_struct *work) |
1da177e4 | 409 | { |
c4028958 DH |
410 | struct multipath *m = |
411 | container_of(work, struct multipath, process_queued_ios); | |
1da177e4 | 412 | struct hw_handler *hwh = &m->hw_handler; |
c3cd4f6b AK |
413 | struct pgpath *pgpath = NULL; |
414 | unsigned init_required = 0, must_queue = 1; | |
1da177e4 LT |
415 | unsigned long flags; |
416 | ||
417 | spin_lock_irqsave(&m->lock, flags); | |
418 | ||
c3cd4f6b AK |
419 | if (!m->queue_size) |
420 | goto out; | |
421 | ||
1da177e4 LT |
422 | if (!m->current_pgpath) |
423 | __choose_pgpath(m); | |
424 | ||
425 | pgpath = m->current_pgpath; | |
426 | ||
c3cd4f6b AK |
427 | if ((pgpath && !m->queue_io) || |
428 | (!pgpath && !m->queue_if_no_path)) | |
429 | must_queue = 0; | |
1da177e4 | 430 | |
c3cd4f6b | 431 | if (m->pg_init_required && !m->pg_init_in_progress) { |
c9e45581 | 432 | m->pg_init_count++; |
1da177e4 | 433 | m->pg_init_required = 0; |
c3cd4f6b AK |
434 | m->pg_init_in_progress = 1; |
435 | init_required = 1; | |
436 | } | |
1da177e4 | 437 | |
c3cd4f6b | 438 | out: |
1da177e4 LT |
439 | spin_unlock_irqrestore(&m->lock, flags); |
440 | ||
441 | if (init_required) | |
442 | hwh->type->pg_init(hwh, pgpath->pg->bypassed, &pgpath->path); | |
443 | ||
444 | if (!must_queue) | |
445 | dispatch_queued_ios(m); | |
446 | } | |
447 | ||
448 | /* | |
449 | * An event is triggered whenever a path is taken out of use. | |
450 | * Includes path failure and PG bypass. | |
451 | */ | |
c4028958 | 452 | static void trigger_event(struct work_struct *work) |
1da177e4 | 453 | { |
c4028958 DH |
454 | struct multipath *m = |
455 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
456 | |
457 | dm_table_event(m->ti->table); | |
458 | } | |
459 | ||
460 | /*----------------------------------------------------------------- | |
461 | * Constructor/argument parsing: | |
462 | * <#multipath feature args> [<arg>]* | |
463 | * <#hw_handler args> [hw_handler [<arg>]*] | |
464 | * <#priority groups> | |
465 | * <initial priority group> | |
466 | * [<selector> <#selector args> [<arg>]* | |
467 | * <#paths> <#per-path selector args> | |
468 | * [<path> [<arg>]* ]+ ]+ | |
469 | *---------------------------------------------------------------*/ | |
470 | struct param { | |
471 | unsigned min; | |
472 | unsigned max; | |
473 | char *error; | |
474 | }; | |
475 | ||
1da177e4 LT |
476 | static int read_param(struct param *param, char *str, unsigned *v, char **error) |
477 | { | |
478 | if (!str || | |
479 | (sscanf(str, "%u", v) != 1) || | |
480 | (*v < param->min) || | |
481 | (*v > param->max)) { | |
482 | *error = param->error; | |
483 | return -EINVAL; | |
484 | } | |
485 | ||
486 | return 0; | |
487 | } | |
488 | ||
489 | struct arg_set { | |
490 | unsigned argc; | |
491 | char **argv; | |
492 | }; | |
493 | ||
494 | static char *shift(struct arg_set *as) | |
495 | { | |
496 | char *r; | |
497 | ||
498 | if (as->argc) { | |
499 | as->argc--; | |
500 | r = *as->argv; | |
501 | as->argv++; | |
502 | return r; | |
503 | } | |
504 | ||
505 | return NULL; | |
506 | } | |
507 | ||
508 | static void consume(struct arg_set *as, unsigned n) | |
509 | { | |
510 | BUG_ON (as->argc < n); | |
511 | as->argc -= n; | |
512 | as->argv += n; | |
513 | } | |
514 | ||
515 | static int parse_path_selector(struct arg_set *as, struct priority_group *pg, | |
516 | struct dm_target *ti) | |
517 | { | |
518 | int r; | |
519 | struct path_selector_type *pst; | |
520 | unsigned ps_argc; | |
521 | ||
522 | static struct param _params[] = { | |
72d94861 | 523 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
524 | }; |
525 | ||
526 | pst = dm_get_path_selector(shift(as)); | |
527 | if (!pst) { | |
72d94861 | 528 | ti->error = "unknown path selector type"; |
1da177e4 LT |
529 | return -EINVAL; |
530 | } | |
531 | ||
532 | r = read_param(_params, shift(as), &ps_argc, &ti->error); | |
533 | if (r) | |
534 | return -EINVAL; | |
535 | ||
536 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
537 | if (r) { | |
538 | dm_put_path_selector(pst); | |
72d94861 | 539 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
540 | return r; |
541 | } | |
542 | ||
543 | pg->ps.type = pst; | |
544 | consume(as, ps_argc); | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
549 | static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, | |
550 | struct dm_target *ti) | |
551 | { | |
552 | int r; | |
553 | struct pgpath *p; | |
554 | ||
555 | /* we need at least a path arg */ | |
556 | if (as->argc < 1) { | |
72d94861 | 557 | ti->error = "no device given"; |
1da177e4 LT |
558 | return NULL; |
559 | } | |
560 | ||
561 | p = alloc_pgpath(); | |
562 | if (!p) | |
563 | return NULL; | |
564 | ||
565 | r = dm_get_device(ti, shift(as), ti->begin, ti->len, | |
566 | dm_table_get_mode(ti->table), &p->path.dev); | |
567 | if (r) { | |
72d94861 | 568 | ti->error = "error getting device"; |
1da177e4 LT |
569 | goto bad; |
570 | } | |
571 | ||
572 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); | |
573 | if (r) { | |
574 | dm_put_device(ti, p->path.dev); | |
575 | goto bad; | |
576 | } | |
577 | ||
578 | return p; | |
579 | ||
580 | bad: | |
581 | free_pgpath(p); | |
582 | return NULL; | |
583 | } | |
584 | ||
585 | static struct priority_group *parse_priority_group(struct arg_set *as, | |
28f16c20 | 586 | struct multipath *m) |
1da177e4 LT |
587 | { |
588 | static struct param _params[] = { | |
72d94861 AK |
589 | {1, 1024, "invalid number of paths"}, |
590 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
591 | }; |
592 | ||
593 | int r; | |
594 | unsigned i, nr_selector_args, nr_params; | |
595 | struct priority_group *pg; | |
28f16c20 | 596 | struct dm_target *ti = m->ti; |
1da177e4 LT |
597 | |
598 | if (as->argc < 2) { | |
599 | as->argc = 0; | |
72d94861 | 600 | ti->error = "not enough priority group aruments"; |
1da177e4 LT |
601 | return NULL; |
602 | } | |
603 | ||
604 | pg = alloc_priority_group(); | |
605 | if (!pg) { | |
72d94861 | 606 | ti->error = "couldn't allocate priority group"; |
1da177e4 LT |
607 | return NULL; |
608 | } | |
609 | pg->m = m; | |
610 | ||
611 | r = parse_path_selector(as, pg, ti); | |
612 | if (r) | |
613 | goto bad; | |
614 | ||
615 | /* | |
616 | * read the paths | |
617 | */ | |
618 | r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error); | |
619 | if (r) | |
620 | goto bad; | |
621 | ||
622 | r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error); | |
623 | if (r) | |
624 | goto bad; | |
625 | ||
626 | nr_params = 1 + nr_selector_args; | |
627 | for (i = 0; i < pg->nr_pgpaths; i++) { | |
628 | struct pgpath *pgpath; | |
629 | struct arg_set path_args; | |
630 | ||
631 | if (as->argc < nr_params) | |
632 | goto bad; | |
633 | ||
634 | path_args.argc = nr_params; | |
635 | path_args.argv = as->argv; | |
636 | ||
637 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
638 | if (!pgpath) | |
639 | goto bad; | |
640 | ||
641 | pgpath->pg = pg; | |
642 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
643 | consume(as, nr_params); | |
644 | } | |
645 | ||
646 | return pg; | |
647 | ||
648 | bad: | |
649 | free_priority_group(pg, ti); | |
650 | return NULL; | |
651 | } | |
652 | ||
28f16c20 | 653 | static int parse_hw_handler(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
654 | { |
655 | int r; | |
656 | struct hw_handler_type *hwht; | |
657 | unsigned hw_argc; | |
28f16c20 | 658 | struct dm_target *ti = m->ti; |
1da177e4 LT |
659 | |
660 | static struct param _params[] = { | |
72d94861 | 661 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
662 | }; |
663 | ||
664 | r = read_param(_params, shift(as), &hw_argc, &ti->error); | |
665 | if (r) | |
666 | return -EINVAL; | |
667 | ||
668 | if (!hw_argc) | |
669 | return 0; | |
670 | ||
671 | hwht = dm_get_hw_handler(shift(as)); | |
672 | if (!hwht) { | |
72d94861 | 673 | ti->error = "unknown hardware handler type"; |
1da177e4 LT |
674 | return -EINVAL; |
675 | } | |
676 | ||
79eb885c EG |
677 | m->hw_handler.md = dm_table_get_md(ti->table); |
678 | dm_put(m->hw_handler.md); | |
679 | ||
1da177e4 LT |
680 | r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv); |
681 | if (r) { | |
682 | dm_put_hw_handler(hwht); | |
72d94861 | 683 | ti->error = "hardware handler constructor failed"; |
1da177e4 LT |
684 | return r; |
685 | } | |
686 | ||
687 | m->hw_handler.type = hwht; | |
688 | consume(as, hw_argc - 1); | |
689 | ||
690 | return 0; | |
691 | } | |
692 | ||
28f16c20 | 693 | static int parse_features(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
694 | { |
695 | int r; | |
696 | unsigned argc; | |
28f16c20 | 697 | struct dm_target *ti = m->ti; |
c9e45581 | 698 | const char *param_name; |
1da177e4 LT |
699 | |
700 | static struct param _params[] = { | |
c9e45581 DW |
701 | {0, 3, "invalid number of feature args"}, |
702 | {1, 50, "pg_init_retries must be between 1 and 50"}, | |
1da177e4 LT |
703 | }; |
704 | ||
705 | r = read_param(_params, shift(as), &argc, &ti->error); | |
706 | if (r) | |
707 | return -EINVAL; | |
708 | ||
709 | if (!argc) | |
710 | return 0; | |
711 | ||
c9e45581 DW |
712 | do { |
713 | param_name = shift(as); | |
714 | argc--; | |
715 | ||
716 | if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { | |
717 | r = queue_if_no_path(m, 1, 0); | |
718 | continue; | |
719 | } | |
720 | ||
721 | if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && | |
722 | (argc >= 1)) { | |
723 | r = read_param(_params + 1, shift(as), | |
724 | &m->pg_init_retries, &ti->error); | |
725 | argc--; | |
726 | continue; | |
727 | } | |
728 | ||
1da177e4 | 729 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
730 | r = -EINVAL; |
731 | } while (argc && !r); | |
732 | ||
733 | return r; | |
1da177e4 LT |
734 | } |
735 | ||
736 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
737 | char **argv) | |
738 | { | |
739 | /* target parameters */ | |
740 | static struct param _params[] = { | |
72d94861 AK |
741 | {1, 1024, "invalid number of priority groups"}, |
742 | {1, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
743 | }; |
744 | ||
745 | int r; | |
746 | struct multipath *m; | |
747 | struct arg_set as; | |
748 | unsigned pg_count = 0; | |
749 | unsigned next_pg_num; | |
750 | ||
751 | as.argc = argc; | |
752 | as.argv = argv; | |
753 | ||
28f16c20 | 754 | m = alloc_multipath(ti); |
1da177e4 | 755 | if (!m) { |
72d94861 | 756 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
757 | return -EINVAL; |
758 | } | |
759 | ||
28f16c20 | 760 | r = parse_features(&as, m); |
1da177e4 LT |
761 | if (r) |
762 | goto bad; | |
763 | ||
28f16c20 | 764 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
765 | if (r) |
766 | goto bad; | |
767 | ||
768 | r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error); | |
769 | if (r) | |
770 | goto bad; | |
771 | ||
772 | r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error); | |
773 | if (r) | |
774 | goto bad; | |
775 | ||
776 | /* parse the priority groups */ | |
777 | while (as.argc) { | |
778 | struct priority_group *pg; | |
779 | ||
28f16c20 | 780 | pg = parse_priority_group(&as, m); |
1da177e4 LT |
781 | if (!pg) { |
782 | r = -EINVAL; | |
783 | goto bad; | |
784 | } | |
785 | ||
786 | m->nr_valid_paths += pg->nr_pgpaths; | |
787 | list_add_tail(&pg->list, &m->priority_groups); | |
788 | pg_count++; | |
789 | pg->pg_num = pg_count; | |
790 | if (!--next_pg_num) | |
791 | m->next_pg = pg; | |
792 | } | |
793 | ||
794 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 795 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
796 | r = -EINVAL; |
797 | goto bad; | |
798 | } | |
799 | ||
1da177e4 LT |
800 | return 0; |
801 | ||
802 | bad: | |
803 | free_multipath(m); | |
804 | return r; | |
805 | } | |
806 | ||
807 | static void multipath_dtr(struct dm_target *ti) | |
808 | { | |
809 | struct multipath *m = (struct multipath *) ti->private; | |
a044d016 AK |
810 | |
811 | flush_workqueue(kmultipathd); | |
1da177e4 LT |
812 | free_multipath(m); |
813 | } | |
814 | ||
815 | /* | |
816 | * Map bios, recording original fields for later in case we have to resubmit | |
817 | */ | |
818 | static int multipath_map(struct dm_target *ti, struct bio *bio, | |
819 | union map_info *map_context) | |
820 | { | |
821 | int r; | |
028867ac | 822 | struct dm_mpath_io *mpio; |
1da177e4 LT |
823 | struct multipath *m = (struct multipath *) ti->private; |
824 | ||
825 | mpio = mempool_alloc(m->mpio_pool, GFP_NOIO); | |
826 | dm_bio_record(&mpio->details, bio); | |
827 | ||
828 | map_context->ptr = mpio; | |
829 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); | |
830 | r = map_io(m, bio, mpio, 0); | |
45e15720 | 831 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
1da177e4 LT |
832 | mempool_free(mpio, m->mpio_pool); |
833 | ||
834 | return r; | |
835 | } | |
836 | ||
837 | /* | |
838 | * Take a path out of use. | |
839 | */ | |
840 | static int fail_path(struct pgpath *pgpath) | |
841 | { | |
842 | unsigned long flags; | |
843 | struct multipath *m = pgpath->pg->m; | |
844 | ||
845 | spin_lock_irqsave(&m->lock, flags); | |
846 | ||
847 | if (!pgpath->path.is_active) | |
848 | goto out; | |
849 | ||
72d94861 | 850 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
851 | |
852 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
853 | pgpath->path.is_active = 0; | |
854 | pgpath->fail_count++; | |
855 | ||
856 | m->nr_valid_paths--; | |
857 | ||
858 | if (pgpath == m->current_pgpath) | |
859 | m->current_pgpath = NULL; | |
860 | ||
b15546f9 MA |
861 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
862 | pgpath->path.dev->name, m->nr_valid_paths); | |
863 | ||
c557308e | 864 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
865 | |
866 | out: | |
867 | spin_unlock_irqrestore(&m->lock, flags); | |
868 | ||
869 | return 0; | |
870 | } | |
871 | ||
872 | /* | |
873 | * Reinstate a previously-failed path | |
874 | */ | |
875 | static int reinstate_path(struct pgpath *pgpath) | |
876 | { | |
877 | int r = 0; | |
878 | unsigned long flags; | |
879 | struct multipath *m = pgpath->pg->m; | |
880 | ||
881 | spin_lock_irqsave(&m->lock, flags); | |
882 | ||
883 | if (pgpath->path.is_active) | |
884 | goto out; | |
885 | ||
886 | if (!pgpath->pg->ps.type) { | |
887 | DMWARN("Reinstate path not supported by path selector %s", | |
888 | pgpath->pg->ps.type->name); | |
889 | r = -EINVAL; | |
890 | goto out; | |
891 | } | |
892 | ||
893 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
894 | if (r) | |
895 | goto out; | |
896 | ||
897 | pgpath->path.is_active = 1; | |
898 | ||
899 | m->current_pgpath = NULL; | |
c3cd4f6b | 900 | if (!m->nr_valid_paths++ && m->queue_size) |
c557308e | 901 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 902 | |
b15546f9 MA |
903 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
904 | pgpath->path.dev->name, m->nr_valid_paths); | |
905 | ||
c557308e | 906 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
907 | |
908 | out: | |
909 | spin_unlock_irqrestore(&m->lock, flags); | |
910 | ||
911 | return r; | |
912 | } | |
913 | ||
914 | /* | |
915 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
916 | */ | |
917 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
918 | action_fn action) | |
919 | { | |
920 | int r = 0; | |
921 | struct pgpath *pgpath; | |
922 | struct priority_group *pg; | |
923 | ||
924 | list_for_each_entry(pg, &m->priority_groups, list) { | |
925 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
926 | if (pgpath->path.dev == dev) | |
927 | r = action(pgpath); | |
928 | } | |
929 | } | |
930 | ||
931 | return r; | |
932 | } | |
933 | ||
934 | /* | |
935 | * Temporarily try to avoid having to use the specified PG | |
936 | */ | |
937 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
938 | int bypassed) | |
939 | { | |
940 | unsigned long flags; | |
941 | ||
942 | spin_lock_irqsave(&m->lock, flags); | |
943 | ||
944 | pg->bypassed = bypassed; | |
945 | m->current_pgpath = NULL; | |
946 | m->current_pg = NULL; | |
947 | ||
948 | spin_unlock_irqrestore(&m->lock, flags); | |
949 | ||
c557308e | 950 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
951 | } |
952 | ||
953 | /* | |
954 | * Switch to using the specified PG from the next I/O that gets mapped | |
955 | */ | |
956 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
957 | { | |
958 | struct priority_group *pg; | |
959 | unsigned pgnum; | |
960 | unsigned long flags; | |
961 | ||
962 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
963 | (pgnum > m->nr_priority_groups)) { | |
964 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
965 | return -EINVAL; | |
966 | } | |
967 | ||
968 | spin_lock_irqsave(&m->lock, flags); | |
969 | list_for_each_entry(pg, &m->priority_groups, list) { | |
970 | pg->bypassed = 0; | |
971 | if (--pgnum) | |
972 | continue; | |
973 | ||
974 | m->current_pgpath = NULL; | |
975 | m->current_pg = NULL; | |
976 | m->next_pg = pg; | |
977 | } | |
978 | spin_unlock_irqrestore(&m->lock, flags); | |
979 | ||
c557308e | 980 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
981 | return 0; |
982 | } | |
983 | ||
984 | /* | |
985 | * Set/clear bypassed status of a PG. | |
986 | * PGs are numbered upwards from 1 in the order they were declared. | |
987 | */ | |
988 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
989 | { | |
990 | struct priority_group *pg; | |
991 | unsigned pgnum; | |
992 | ||
993 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
994 | (pgnum > m->nr_priority_groups)) { | |
995 | DMWARN("invalid PG number supplied to bypass_pg"); | |
996 | return -EINVAL; | |
997 | } | |
998 | ||
999 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1000 | if (!--pgnum) | |
1001 | break; | |
1002 | } | |
1003 | ||
1004 | bypass_pg(m, pg, bypassed); | |
1005 | return 0; | |
1006 | } | |
1007 | ||
c9e45581 DW |
1008 | /* |
1009 | * Should we retry pg_init immediately? | |
1010 | */ | |
1011 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1012 | { | |
1013 | unsigned long flags; | |
1014 | int limit_reached = 0; | |
1015 | ||
1016 | spin_lock_irqsave(&m->lock, flags); | |
1017 | ||
1018 | if (m->pg_init_count <= m->pg_init_retries) | |
1019 | m->pg_init_required = 1; | |
1020 | else | |
1021 | limit_reached = 1; | |
1022 | ||
1023 | spin_unlock_irqrestore(&m->lock, flags); | |
1024 | ||
1025 | return limit_reached; | |
1026 | } | |
1027 | ||
1da177e4 LT |
1028 | /* |
1029 | * pg_init must call this when it has completed its initialisation | |
1030 | */ | |
c922d5f7 | 1031 | void dm_pg_init_complete(struct dm_path *path, unsigned err_flags) |
1da177e4 LT |
1032 | { |
1033 | struct pgpath *pgpath = path_to_pgpath(path); | |
1034 | struct priority_group *pg = pgpath->pg; | |
1035 | struct multipath *m = pg->m; | |
1036 | unsigned long flags; | |
1037 | ||
c9e45581 DW |
1038 | /* |
1039 | * If requested, retry pg_init until maximum number of retries exceeded. | |
1040 | * If retry not requested and PG already bypassed, always fail the path. | |
1041 | */ | |
1042 | if (err_flags & MP_RETRY) { | |
1043 | if (pg_init_limit_reached(m, pgpath)) | |
1044 | err_flags |= MP_FAIL_PATH; | |
1045 | } else if (err_flags && pg->bypassed) | |
1da177e4 LT |
1046 | err_flags |= MP_FAIL_PATH; |
1047 | ||
1048 | if (err_flags & MP_FAIL_PATH) | |
1049 | fail_path(pgpath); | |
1050 | ||
1051 | if (err_flags & MP_BYPASS_PG) | |
1052 | bypass_pg(m, pg, 1); | |
1053 | ||
1054 | spin_lock_irqsave(&m->lock, flags); | |
c9e45581 | 1055 | if (err_flags & ~MP_RETRY) { |
1da177e4 LT |
1056 | m->current_pgpath = NULL; |
1057 | m->current_pg = NULL; | |
c3cd4f6b AK |
1058 | } else if (!m->pg_init_required) |
1059 | m->queue_io = 0; | |
1060 | ||
1061 | m->pg_init_in_progress = 0; | |
c557308e | 1062 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
1063 | spin_unlock_irqrestore(&m->lock, flags); |
1064 | } | |
1065 | ||
1066 | /* | |
1067 | * end_io handling | |
1068 | */ | |
1069 | static int do_end_io(struct multipath *m, struct bio *bio, | |
028867ac | 1070 | int error, struct dm_mpath_io *mpio) |
1da177e4 LT |
1071 | { |
1072 | struct hw_handler *hwh = &m->hw_handler; | |
1073 | unsigned err_flags = MP_FAIL_PATH; /* Default behavior */ | |
640eb3b0 | 1074 | unsigned long flags; |
1da177e4 LT |
1075 | |
1076 | if (!error) | |
1077 | return 0; /* I/O complete */ | |
1078 | ||
4f58802f LMB |
1079 | if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio)) |
1080 | return error; | |
1081 | ||
f6a80ea8 AK |
1082 | if (error == -EOPNOTSUPP) |
1083 | return error; | |
1084 | ||
640eb3b0 | 1085 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 1086 | if (!m->nr_valid_paths) { |
45e15720 KU |
1087 | if (__must_push_back(m)) { |
1088 | spin_unlock_irqrestore(&m->lock, flags); | |
1089 | return DM_ENDIO_REQUEUE; | |
1090 | } else if (!m->queue_if_no_path) { | |
640eb3b0 | 1091 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1092 | return -EIO; |
1093 | } else { | |
640eb3b0 | 1094 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1095 | goto requeue; |
1096 | } | |
1097 | } | |
640eb3b0 | 1098 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1099 | |
1100 | if (hwh->type && hwh->type->error) | |
1101 | err_flags = hwh->type->error(hwh, bio); | |
1102 | ||
1103 | if (mpio->pgpath) { | |
1104 | if (err_flags & MP_FAIL_PATH) | |
1105 | fail_path(mpio->pgpath); | |
1106 | ||
1107 | if (err_flags & MP_BYPASS_PG) | |
1108 | bypass_pg(m, mpio->pgpath->pg, 1); | |
1109 | } | |
1110 | ||
1111 | if (err_flags & MP_ERROR_IO) | |
1112 | return -EIO; | |
1113 | ||
1114 | requeue: | |
1115 | dm_bio_restore(&mpio->details, bio); | |
1116 | ||
1117 | /* queue for the daemon to resubmit or fail */ | |
640eb3b0 | 1118 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
1119 | bio_list_add(&m->queued_ios, bio); |
1120 | m->queue_size++; | |
1121 | if (!m->queue_io) | |
c557308e | 1122 | queue_work(kmultipathd, &m->process_queued_ios); |
640eb3b0 | 1123 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1124 | |
d2a7ad29 | 1125 | return DM_ENDIO_INCOMPLETE; /* io not complete */ |
1da177e4 LT |
1126 | } |
1127 | ||
1128 | static int multipath_end_io(struct dm_target *ti, struct bio *bio, | |
1129 | int error, union map_info *map_context) | |
1130 | { | |
028867ac AK |
1131 | struct multipath *m = ti->private; |
1132 | struct dm_mpath_io *mpio = map_context->ptr; | |
1da177e4 LT |
1133 | struct pgpath *pgpath = mpio->pgpath; |
1134 | struct path_selector *ps; | |
1135 | int r; | |
1136 | ||
1137 | r = do_end_io(m, bio, error, mpio); | |
1138 | if (pgpath) { | |
1139 | ps = &pgpath->pg->ps; | |
1140 | if (ps->type->end_io) | |
1141 | ps->type->end_io(ps, &pgpath->path); | |
1142 | } | |
d2a7ad29 | 1143 | if (r != DM_ENDIO_INCOMPLETE) |
1da177e4 LT |
1144 | mempool_free(mpio, m->mpio_pool); |
1145 | ||
1146 | return r; | |
1147 | } | |
1148 | ||
1149 | /* | |
1150 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1151 | * the last path fails we must error any remaining I/O. |
1152 | * Note that if the freeze_bdev fails while suspending, the | |
1153 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1154 | */ |
1155 | static void multipath_presuspend(struct dm_target *ti) | |
1156 | { | |
1157 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1158 | |
485ef69e | 1159 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1160 | } |
1161 | ||
436d4108 AK |
1162 | /* |
1163 | * Restore the queue_if_no_path setting. | |
1164 | */ | |
1da177e4 LT |
1165 | static void multipath_resume(struct dm_target *ti) |
1166 | { | |
1167 | struct multipath *m = (struct multipath *) ti->private; | |
1168 | unsigned long flags; | |
1169 | ||
1170 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1171 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1172 | spin_unlock_irqrestore(&m->lock, flags); |
1173 | } | |
1174 | ||
1175 | /* | |
1176 | * Info output has the following format: | |
1177 | * num_multipath_feature_args [multipath_feature_args]* | |
1178 | * num_handler_status_args [handler_status_args]* | |
1179 | * num_groups init_group_number | |
1180 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1181 | * num_paths num_selector_args | |
1182 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1183 | * | |
1184 | * Table output has the following format (identical to the constructor string): | |
1185 | * num_feature_args [features_args]* | |
1186 | * num_handler_args hw_handler [hw_handler_args]* | |
1187 | * num_groups init_group_number | |
1188 | * [priority selector-name num_ps_args [ps_args]* | |
1189 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1190 | */ | |
1191 | static int multipath_status(struct dm_target *ti, status_type_t type, | |
1192 | char *result, unsigned int maxlen) | |
1193 | { | |
1194 | int sz = 0; | |
1195 | unsigned long flags; | |
1196 | struct multipath *m = (struct multipath *) ti->private; | |
1197 | struct hw_handler *hwh = &m->hw_handler; | |
1198 | struct priority_group *pg; | |
1199 | struct pgpath *p; | |
1200 | unsigned pg_num; | |
1201 | char state; | |
1202 | ||
1203 | spin_lock_irqsave(&m->lock, flags); | |
1204 | ||
1205 | /* Features */ | |
1206 | if (type == STATUSTYPE_INFO) | |
c9e45581 DW |
1207 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
1208 | else { | |
1209 | DMEMIT("%u ", m->queue_if_no_path + | |
1210 | (m->pg_init_retries > 0) * 2); | |
1211 | if (m->queue_if_no_path) | |
1212 | DMEMIT("queue_if_no_path "); | |
1213 | if (m->pg_init_retries) | |
1214 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
1215 | } | |
1da177e4 LT |
1216 | |
1217 | if (hwh->type && hwh->type->status) | |
1218 | sz += hwh->type->status(hwh, type, result + sz, maxlen - sz); | |
1219 | else if (!hwh->type || type == STATUSTYPE_INFO) | |
1220 | DMEMIT("0 "); | |
1221 | else | |
1222 | DMEMIT("1 %s ", hwh->type->name); | |
1223 | ||
1224 | DMEMIT("%u ", m->nr_priority_groups); | |
1225 | ||
1226 | if (m->next_pg) | |
1227 | pg_num = m->next_pg->pg_num; | |
1228 | else if (m->current_pg) | |
1229 | pg_num = m->current_pg->pg_num; | |
1230 | else | |
1231 | pg_num = 1; | |
1232 | ||
1233 | DMEMIT("%u ", pg_num); | |
1234 | ||
1235 | switch (type) { | |
1236 | case STATUSTYPE_INFO: | |
1237 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1238 | if (pg->bypassed) | |
1239 | state = 'D'; /* Disabled */ | |
1240 | else if (pg == m->current_pg) | |
1241 | state = 'A'; /* Currently Active */ | |
1242 | else | |
1243 | state = 'E'; /* Enabled */ | |
1244 | ||
1245 | DMEMIT("%c ", state); | |
1246 | ||
1247 | if (pg->ps.type->status) | |
1248 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1249 | result + sz, | |
1250 | maxlen - sz); | |
1251 | else | |
1252 | DMEMIT("0 "); | |
1253 | ||
1254 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1255 | pg->ps.type->info_args); | |
1256 | ||
1257 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1258 | DMEMIT("%s %s %u ", p->path.dev->name, | |
1259 | p->path.is_active ? "A" : "F", | |
1260 | p->fail_count); | |
1261 | if (pg->ps.type->status) | |
1262 | sz += pg->ps.type->status(&pg->ps, | |
1263 | &p->path, type, result + sz, | |
1264 | maxlen - sz); | |
1265 | } | |
1266 | } | |
1267 | break; | |
1268 | ||
1269 | case STATUSTYPE_TABLE: | |
1270 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1271 | DMEMIT("%s ", pg->ps.type->name); | |
1272 | ||
1273 | if (pg->ps.type->status) | |
1274 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1275 | result + sz, | |
1276 | maxlen - sz); | |
1277 | else | |
1278 | DMEMIT("0 "); | |
1279 | ||
1280 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1281 | pg->ps.type->table_args); | |
1282 | ||
1283 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1284 | DMEMIT("%s ", p->path.dev->name); | |
1285 | if (pg->ps.type->status) | |
1286 | sz += pg->ps.type->status(&pg->ps, | |
1287 | &p->path, type, result + sz, | |
1288 | maxlen - sz); | |
1289 | } | |
1290 | } | |
1291 | break; | |
1292 | } | |
1293 | ||
1294 | spin_unlock_irqrestore(&m->lock, flags); | |
1295 | ||
1296 | return 0; | |
1297 | } | |
1298 | ||
1299 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1300 | { | |
1301 | int r; | |
1302 | struct dm_dev *dev; | |
1303 | struct multipath *m = (struct multipath *) ti->private; | |
1304 | action_fn action; | |
1305 | ||
1306 | if (argc == 1) { | |
1307 | if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) | |
485ef69e | 1308 | return queue_if_no_path(m, 1, 0); |
1da177e4 | 1309 | else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) |
485ef69e | 1310 | return queue_if_no_path(m, 0, 0); |
1da177e4 LT |
1311 | } |
1312 | ||
1313 | if (argc != 2) | |
1314 | goto error; | |
1315 | ||
1316 | if (!strnicmp(argv[0], MESG_STR("disable_group"))) | |
1317 | return bypass_pg_num(m, argv[1], 1); | |
1318 | else if (!strnicmp(argv[0], MESG_STR("enable_group"))) | |
1319 | return bypass_pg_num(m, argv[1], 0); | |
1320 | else if (!strnicmp(argv[0], MESG_STR("switch_group"))) | |
1321 | return switch_pg_num(m, argv[1]); | |
1322 | else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) | |
1323 | action = reinstate_path; | |
1324 | else if (!strnicmp(argv[0], MESG_STR("fail_path"))) | |
1325 | action = fail_path; | |
1326 | else | |
1327 | goto error; | |
1328 | ||
1329 | r = dm_get_device(ti, argv[1], ti->begin, ti->len, | |
1330 | dm_table_get_mode(ti->table), &dev); | |
1331 | if (r) { | |
72d94861 | 1332 | DMWARN("message: error getting device %s", |
1da177e4 LT |
1333 | argv[1]); |
1334 | return -EINVAL; | |
1335 | } | |
1336 | ||
1337 | r = action_dev(m, dev, action); | |
1338 | ||
1339 | dm_put_device(ti, dev); | |
1340 | ||
1341 | return r; | |
1342 | ||
1343 | error: | |
1344 | DMWARN("Unrecognised multipath message received."); | |
1345 | return -EINVAL; | |
1346 | } | |
1347 | ||
9af4aa30 MB |
1348 | static int multipath_ioctl(struct dm_target *ti, struct inode *inode, |
1349 | struct file *filp, unsigned int cmd, | |
1350 | unsigned long arg) | |
1351 | { | |
1352 | struct multipath *m = (struct multipath *) ti->private; | |
1353 | struct block_device *bdev = NULL; | |
1354 | unsigned long flags; | |
e90dae1f MB |
1355 | struct file fake_file = {}; |
1356 | struct dentry fake_dentry = {}; | |
9af4aa30 MB |
1357 | int r = 0; |
1358 | ||
c649bb9c | 1359 | fake_file.f_path.dentry = &fake_dentry; |
e90dae1f | 1360 | |
9af4aa30 MB |
1361 | spin_lock_irqsave(&m->lock, flags); |
1362 | ||
1363 | if (!m->current_pgpath) | |
1364 | __choose_pgpath(m); | |
1365 | ||
e90dae1f | 1366 | if (m->current_pgpath) { |
9af4aa30 | 1367 | bdev = m->current_pgpath->path.dev->bdev; |
e90dae1f MB |
1368 | fake_dentry.d_inode = bdev->bd_inode; |
1369 | fake_file.f_mode = m->current_pgpath->path.dev->mode; | |
1370 | } | |
9af4aa30 MB |
1371 | |
1372 | if (m->queue_io) | |
1373 | r = -EAGAIN; | |
1374 | else if (!bdev) | |
1375 | r = -EIO; | |
1376 | ||
1377 | spin_unlock_irqrestore(&m->lock, flags); | |
1378 | ||
e90dae1f MB |
1379 | return r ? : blkdev_driver_ioctl(bdev->bd_inode, &fake_file, |
1380 | bdev->bd_disk, cmd, arg); | |
9af4aa30 MB |
1381 | } |
1382 | ||
1da177e4 LT |
1383 | /*----------------------------------------------------------------- |
1384 | * Module setup | |
1385 | *---------------------------------------------------------------*/ | |
1386 | static struct target_type multipath_target = { | |
1387 | .name = "multipath", | |
9af4aa30 | 1388 | .version = {1, 0, 5}, |
1da177e4 LT |
1389 | .module = THIS_MODULE, |
1390 | .ctr = multipath_ctr, | |
1391 | .dtr = multipath_dtr, | |
1392 | .map = multipath_map, | |
1393 | .end_io = multipath_end_io, | |
1394 | .presuspend = multipath_presuspend, | |
1395 | .resume = multipath_resume, | |
1396 | .status = multipath_status, | |
1397 | .message = multipath_message, | |
9af4aa30 | 1398 | .ioctl = multipath_ioctl, |
1da177e4 LT |
1399 | }; |
1400 | ||
1401 | static int __init dm_multipath_init(void) | |
1402 | { | |
1403 | int r; | |
1404 | ||
1405 | /* allocate a slab for the dm_ios */ | |
028867ac | 1406 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1407 | if (!_mpio_cache) |
1408 | return -ENOMEM; | |
1409 | ||
1410 | r = dm_register_target(&multipath_target); | |
1411 | if (r < 0) { | |
0cd33124 | 1412 | DMERR("register failed %d", r); |
1da177e4 LT |
1413 | kmem_cache_destroy(_mpio_cache); |
1414 | return -EINVAL; | |
1415 | } | |
1416 | ||
c557308e AK |
1417 | kmultipathd = create_workqueue("kmpathd"); |
1418 | if (!kmultipathd) { | |
0cd33124 | 1419 | DMERR("failed to create workqueue kmpathd"); |
c557308e AK |
1420 | dm_unregister_target(&multipath_target); |
1421 | kmem_cache_destroy(_mpio_cache); | |
1422 | return -ENOMEM; | |
1423 | } | |
1424 | ||
72d94861 | 1425 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1426 | multipath_target.version[0], multipath_target.version[1], |
1427 | multipath_target.version[2]); | |
1428 | ||
1429 | return r; | |
1430 | } | |
1431 | ||
1432 | static void __exit dm_multipath_exit(void) | |
1433 | { | |
1434 | int r; | |
1435 | ||
c557308e AK |
1436 | destroy_workqueue(kmultipathd); |
1437 | ||
1da177e4 LT |
1438 | r = dm_unregister_target(&multipath_target); |
1439 | if (r < 0) | |
0cd33124 | 1440 | DMERR("target unregister failed %d", r); |
1da177e4 LT |
1441 | kmem_cache_destroy(_mpio_cache); |
1442 | } | |
1443 | ||
1444 | EXPORT_SYMBOL_GPL(dm_pg_init_complete); | |
1445 | ||
1446 | module_init(dm_multipath_init); | |
1447 | module_exit(dm_multipath_exit); | |
1448 | ||
1449 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1450 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1451 | MODULE_LICENSE("GPL"); |