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" | |
1da177e4 LT |
10 | #include "dm-bio-list.h" |
11 | #include "dm-bio-record.h" | |
b15546f9 | 12 | #include "dm-uevent.h" |
1da177e4 LT |
13 | |
14 | #include <linux/ctype.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/mempool.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/slab.h> | |
20 | #include <linux/time.h> | |
21 | #include <linux/workqueue.h> | |
cfae5c9b | 22 | #include <scsi/scsi_dh.h> |
1da177e4 LT |
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 | ||
cfae5c9b | 64 | const char *hw_handler_name; |
bab7cfc7 | 65 | struct work_struct activate_path; |
1da177e4 LT |
66 | unsigned nr_priority_groups; |
67 | struct list_head priority_groups; | |
68 | unsigned pg_init_required; /* pg_init needs calling? */ | |
c3cd4f6b | 69 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
1da177e4 LT |
70 | |
71 | unsigned nr_valid_paths; /* Total number of usable paths */ | |
72 | struct pgpath *current_pgpath; | |
73 | struct priority_group *current_pg; | |
74 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
75 | unsigned repeat_count; /* I/Os left before calling PS again */ | |
76 | ||
77 | unsigned queue_io; /* Must we queue all I/O? */ | |
78 | unsigned queue_if_no_path; /* Queue I/O if last path fails? */ | |
436d4108 | 79 | unsigned saved_queue_if_no_path;/* Saved state during suspension */ |
c9e45581 DW |
80 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
81 | unsigned pg_init_count; /* Number of times pg_init called */ | |
1da177e4 LT |
82 | |
83 | struct work_struct process_queued_ios; | |
84 | struct bio_list queued_ios; | |
85 | unsigned queue_size; | |
86 | ||
87 | struct work_struct trigger_event; | |
88 | ||
89 | /* | |
028867ac | 90 | * We must use a mempool of dm_mpath_io structs so that we |
1da177e4 LT |
91 | * can resubmit bios on error. |
92 | */ | |
93 | mempool_t *mpio_pool; | |
94 | }; | |
95 | ||
96 | /* | |
97 | * Context information attached to each bio we process. | |
98 | */ | |
028867ac | 99 | struct dm_mpath_io { |
1da177e4 LT |
100 | struct pgpath *pgpath; |
101 | struct dm_bio_details details; | |
102 | }; | |
103 | ||
104 | typedef int (*action_fn) (struct pgpath *pgpath); | |
105 | ||
106 | #define MIN_IOS 256 /* Mempool size */ | |
107 | ||
e18b890b | 108 | static struct kmem_cache *_mpio_cache; |
1da177e4 | 109 | |
bab7cfc7 | 110 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 DH |
111 | static void process_queued_ios(struct work_struct *work); |
112 | static void trigger_event(struct work_struct *work); | |
bab7cfc7 | 113 | static void activate_path(struct work_struct *work); |
1da177e4 LT |
114 | |
115 | ||
116 | /*----------------------------------------------- | |
117 | * Allocation routines | |
118 | *-----------------------------------------------*/ | |
119 | ||
120 | static struct pgpath *alloc_pgpath(void) | |
121 | { | |
e69fae56 | 122 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 123 | |
e69fae56 | 124 | if (pgpath) |
1da177e4 | 125 | pgpath->path.is_active = 1; |
1da177e4 LT |
126 | |
127 | return pgpath; | |
128 | } | |
129 | ||
028867ac | 130 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
131 | { |
132 | kfree(pgpath); | |
133 | } | |
134 | ||
135 | static struct priority_group *alloc_priority_group(void) | |
136 | { | |
137 | struct priority_group *pg; | |
138 | ||
e69fae56 | 139 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 140 | |
e69fae56 MM |
141 | if (pg) |
142 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
143 | |
144 | return pg; | |
145 | } | |
146 | ||
147 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
148 | { | |
149 | struct pgpath *pgpath, *tmp; | |
150 | ||
151 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
152 | list_del(&pgpath->list); | |
153 | dm_put_device(ti, pgpath->path.dev); | |
154 | free_pgpath(pgpath); | |
155 | } | |
156 | } | |
157 | ||
158 | static void free_priority_group(struct priority_group *pg, | |
159 | struct dm_target *ti) | |
160 | { | |
161 | struct path_selector *ps = &pg->ps; | |
162 | ||
163 | if (ps->type) { | |
164 | ps->type->destroy(ps); | |
165 | dm_put_path_selector(ps->type); | |
166 | } | |
167 | ||
168 | free_pgpaths(&pg->pgpaths, ti); | |
169 | kfree(pg); | |
170 | } | |
171 | ||
28f16c20 | 172 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
173 | { |
174 | struct multipath *m; | |
175 | ||
e69fae56 | 176 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 177 | if (m) { |
1da177e4 LT |
178 | INIT_LIST_HEAD(&m->priority_groups); |
179 | spin_lock_init(&m->lock); | |
180 | m->queue_io = 1; | |
c4028958 DH |
181 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
182 | INIT_WORK(&m->trigger_event, trigger_event); | |
bab7cfc7 | 183 | INIT_WORK(&m->activate_path, activate_path); |
93d2341c | 184 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
1da177e4 LT |
185 | if (!m->mpio_pool) { |
186 | kfree(m); | |
187 | return NULL; | |
188 | } | |
28f16c20 MM |
189 | m->ti = ti; |
190 | ti->private = m; | |
1da177e4 LT |
191 | } |
192 | ||
193 | return m; | |
194 | } | |
195 | ||
196 | static void free_multipath(struct multipath *m) | |
197 | { | |
198 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
199 | |
200 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
201 | list_del(&pg->list); | |
202 | free_priority_group(pg, m->ti); | |
203 | } | |
204 | ||
cfae5c9b | 205 | kfree(m->hw_handler_name); |
1da177e4 LT |
206 | mempool_destroy(m->mpio_pool); |
207 | kfree(m); | |
208 | } | |
209 | ||
210 | ||
211 | /*----------------------------------------------- | |
212 | * Path selection | |
213 | *-----------------------------------------------*/ | |
214 | ||
215 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) | |
216 | { | |
1da177e4 LT |
217 | m->current_pg = pgpath->pg; |
218 | ||
219 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 220 | if (m->hw_handler_name) { |
1da177e4 LT |
221 | m->pg_init_required = 1; |
222 | m->queue_io = 1; | |
223 | } else { | |
224 | m->pg_init_required = 0; | |
225 | m->queue_io = 0; | |
226 | } | |
c9e45581 DW |
227 | |
228 | m->pg_init_count = 0; | |
1da177e4 LT |
229 | } |
230 | ||
231 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg) | |
232 | { | |
c922d5f7 | 233 | struct dm_path *path; |
1da177e4 LT |
234 | |
235 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count); | |
236 | if (!path) | |
237 | return -ENXIO; | |
238 | ||
239 | m->current_pgpath = path_to_pgpath(path); | |
240 | ||
241 | if (m->current_pg != pg) | |
242 | __switch_pg(m, m->current_pgpath); | |
243 | ||
244 | return 0; | |
245 | } | |
246 | ||
247 | static void __choose_pgpath(struct multipath *m) | |
248 | { | |
249 | struct priority_group *pg; | |
250 | unsigned bypassed = 1; | |
251 | ||
252 | if (!m->nr_valid_paths) | |
253 | goto failed; | |
254 | ||
255 | /* Were we instructed to switch PG? */ | |
256 | if (m->next_pg) { | |
257 | pg = m->next_pg; | |
258 | m->next_pg = NULL; | |
259 | if (!__choose_path_in_pg(m, pg)) | |
260 | return; | |
261 | } | |
262 | ||
263 | /* Don't change PG until it has no remaining paths */ | |
264 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg)) | |
265 | return; | |
266 | ||
267 | /* | |
268 | * Loop through priority groups until we find a valid path. | |
269 | * First time we skip PGs marked 'bypassed'. | |
270 | * Second time we only try the ones we skipped. | |
271 | */ | |
272 | do { | |
273 | list_for_each_entry(pg, &m->priority_groups, list) { | |
274 | if (pg->bypassed == bypassed) | |
275 | continue; | |
276 | if (!__choose_path_in_pg(m, pg)) | |
277 | return; | |
278 | } | |
279 | } while (bypassed--); | |
280 | ||
281 | failed: | |
282 | m->current_pgpath = NULL; | |
283 | m->current_pg = NULL; | |
284 | } | |
285 | ||
45e15720 KU |
286 | /* |
287 | * Check whether bios must be queued in the device-mapper core rather | |
288 | * than here in the target. | |
289 | * | |
290 | * m->lock must be held on entry. | |
291 | * | |
292 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
293 | * same value then we are not between multipath_presuspend() | |
294 | * and multipath_resume() calls and we have no need to check | |
295 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
296 | */ | |
297 | static int __must_push_back(struct multipath *m) | |
298 | { | |
299 | return (m->queue_if_no_path != m->saved_queue_if_no_path && | |
300 | dm_noflush_suspending(m->ti)); | |
301 | } | |
302 | ||
028867ac AK |
303 | static int map_io(struct multipath *m, struct bio *bio, |
304 | struct dm_mpath_io *mpio, unsigned was_queued) | |
1da177e4 | 305 | { |
d2a7ad29 | 306 | int r = DM_MAPIO_REMAPPED; |
1da177e4 LT |
307 | unsigned long flags; |
308 | struct pgpath *pgpath; | |
309 | ||
310 | spin_lock_irqsave(&m->lock, flags); | |
311 | ||
312 | /* Do we need to select a new pgpath? */ | |
313 | if (!m->current_pgpath || | |
314 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
315 | __choose_pgpath(m); | |
316 | ||
317 | pgpath = m->current_pgpath; | |
318 | ||
319 | if (was_queued) | |
320 | m->queue_size--; | |
321 | ||
322 | if ((pgpath && m->queue_io) || | |
436d4108 | 323 | (!pgpath && m->queue_if_no_path)) { |
1da177e4 LT |
324 | /* Queue for the daemon to resubmit */ |
325 | bio_list_add(&m->queued_ios, bio); | |
326 | m->queue_size++; | |
c3cd4f6b AK |
327 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
328 | !m->queue_io) | |
c557308e | 329 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 330 | pgpath = NULL; |
d2a7ad29 | 331 | r = DM_MAPIO_SUBMITTED; |
45e15720 | 332 | } else if (pgpath) |
1da177e4 | 333 | bio->bi_bdev = pgpath->path.dev->bdev; |
45e15720 KU |
334 | else if (__must_push_back(m)) |
335 | r = DM_MAPIO_REQUEUE; | |
336 | else | |
337 | r = -EIO; /* Failed */ | |
1da177e4 LT |
338 | |
339 | mpio->pgpath = pgpath; | |
340 | ||
341 | spin_unlock_irqrestore(&m->lock, flags); | |
342 | ||
343 | return r; | |
344 | } | |
345 | ||
346 | /* | |
347 | * If we run out of usable paths, should we queue I/O or error it? | |
348 | */ | |
485ef69e AK |
349 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
350 | unsigned save_old_value) | |
1da177e4 LT |
351 | { |
352 | unsigned long flags; | |
353 | ||
354 | spin_lock_irqsave(&m->lock, flags); | |
355 | ||
485ef69e AK |
356 | if (save_old_value) |
357 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
358 | else | |
359 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 360 | m->queue_if_no_path = queue_if_no_path; |
c3cd4f6b | 361 | if (!m->queue_if_no_path && m->queue_size) |
c557308e | 362 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
363 | |
364 | spin_unlock_irqrestore(&m->lock, flags); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
369 | /*----------------------------------------------------------------- | |
370 | * The multipath daemon is responsible for resubmitting queued ios. | |
371 | *---------------------------------------------------------------*/ | |
372 | ||
373 | static void dispatch_queued_ios(struct multipath *m) | |
374 | { | |
375 | int r; | |
376 | unsigned long flags; | |
377 | struct bio *bio = NULL, *next; | |
028867ac | 378 | struct dm_mpath_io *mpio; |
1da177e4 LT |
379 | union map_info *info; |
380 | ||
381 | spin_lock_irqsave(&m->lock, flags); | |
382 | bio = bio_list_get(&m->queued_ios); | |
383 | spin_unlock_irqrestore(&m->lock, flags); | |
384 | ||
385 | while (bio) { | |
386 | next = bio->bi_next; | |
387 | bio->bi_next = NULL; | |
388 | ||
389 | info = dm_get_mapinfo(bio); | |
390 | mpio = info->ptr; | |
391 | ||
392 | r = map_io(m, bio, mpio, 1); | |
393 | if (r < 0) | |
6712ecf8 | 394 | bio_endio(bio, r); |
d2a7ad29 | 395 | else if (r == DM_MAPIO_REMAPPED) |
1da177e4 | 396 | generic_make_request(bio); |
45e15720 | 397 | else if (r == DM_MAPIO_REQUEUE) |
6712ecf8 | 398 | bio_endio(bio, -EIO); |
1da177e4 LT |
399 | |
400 | bio = next; | |
401 | } | |
402 | } | |
403 | ||
c4028958 | 404 | static void process_queued_ios(struct work_struct *work) |
1da177e4 | 405 | { |
c4028958 DH |
406 | struct multipath *m = |
407 | container_of(work, struct multipath, process_queued_ios); | |
c3cd4f6b AK |
408 | struct pgpath *pgpath = NULL; |
409 | unsigned init_required = 0, must_queue = 1; | |
1da177e4 LT |
410 | unsigned long flags; |
411 | ||
412 | spin_lock_irqsave(&m->lock, flags); | |
413 | ||
c3cd4f6b AK |
414 | if (!m->queue_size) |
415 | goto out; | |
416 | ||
1da177e4 LT |
417 | if (!m->current_pgpath) |
418 | __choose_pgpath(m); | |
419 | ||
420 | pgpath = m->current_pgpath; | |
421 | ||
c3cd4f6b AK |
422 | if ((pgpath && !m->queue_io) || |
423 | (!pgpath && !m->queue_if_no_path)) | |
424 | must_queue = 0; | |
1da177e4 | 425 | |
c3cd4f6b | 426 | if (m->pg_init_required && !m->pg_init_in_progress) { |
c9e45581 | 427 | m->pg_init_count++; |
1da177e4 | 428 | m->pg_init_required = 0; |
c3cd4f6b AK |
429 | m->pg_init_in_progress = 1; |
430 | init_required = 1; | |
431 | } | |
1da177e4 | 432 | |
c3cd4f6b | 433 | out: |
1da177e4 LT |
434 | spin_unlock_irqrestore(&m->lock, flags); |
435 | ||
bab7cfc7 CS |
436 | if (init_required) |
437 | queue_work(kmpath_handlerd, &m->activate_path); | |
1da177e4 LT |
438 | |
439 | if (!must_queue) | |
440 | dispatch_queued_ios(m); | |
441 | } | |
442 | ||
443 | /* | |
444 | * An event is triggered whenever a path is taken out of use. | |
445 | * Includes path failure and PG bypass. | |
446 | */ | |
c4028958 | 447 | static void trigger_event(struct work_struct *work) |
1da177e4 | 448 | { |
c4028958 DH |
449 | struct multipath *m = |
450 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
451 | |
452 | dm_table_event(m->ti->table); | |
453 | } | |
454 | ||
455 | /*----------------------------------------------------------------- | |
456 | * Constructor/argument parsing: | |
457 | * <#multipath feature args> [<arg>]* | |
458 | * <#hw_handler args> [hw_handler [<arg>]*] | |
459 | * <#priority groups> | |
460 | * <initial priority group> | |
461 | * [<selector> <#selector args> [<arg>]* | |
462 | * <#paths> <#per-path selector args> | |
463 | * [<path> [<arg>]* ]+ ]+ | |
464 | *---------------------------------------------------------------*/ | |
465 | struct param { | |
466 | unsigned min; | |
467 | unsigned max; | |
468 | char *error; | |
469 | }; | |
470 | ||
1da177e4 LT |
471 | static int read_param(struct param *param, char *str, unsigned *v, char **error) |
472 | { | |
473 | if (!str || | |
474 | (sscanf(str, "%u", v) != 1) || | |
475 | (*v < param->min) || | |
476 | (*v > param->max)) { | |
477 | *error = param->error; | |
478 | return -EINVAL; | |
479 | } | |
480 | ||
481 | return 0; | |
482 | } | |
483 | ||
484 | struct arg_set { | |
485 | unsigned argc; | |
486 | char **argv; | |
487 | }; | |
488 | ||
489 | static char *shift(struct arg_set *as) | |
490 | { | |
491 | char *r; | |
492 | ||
493 | if (as->argc) { | |
494 | as->argc--; | |
495 | r = *as->argv; | |
496 | as->argv++; | |
497 | return r; | |
498 | } | |
499 | ||
500 | return NULL; | |
501 | } | |
502 | ||
503 | static void consume(struct arg_set *as, unsigned n) | |
504 | { | |
505 | BUG_ON (as->argc < n); | |
506 | as->argc -= n; | |
507 | as->argv += n; | |
508 | } | |
509 | ||
510 | static int parse_path_selector(struct arg_set *as, struct priority_group *pg, | |
511 | struct dm_target *ti) | |
512 | { | |
513 | int r; | |
514 | struct path_selector_type *pst; | |
515 | unsigned ps_argc; | |
516 | ||
517 | static struct param _params[] = { | |
72d94861 | 518 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
519 | }; |
520 | ||
521 | pst = dm_get_path_selector(shift(as)); | |
522 | if (!pst) { | |
72d94861 | 523 | ti->error = "unknown path selector type"; |
1da177e4 LT |
524 | return -EINVAL; |
525 | } | |
526 | ||
527 | r = read_param(_params, shift(as), &ps_argc, &ti->error); | |
371b2e34 MP |
528 | if (r) { |
529 | dm_put_path_selector(pst); | |
1da177e4 | 530 | return -EINVAL; |
371b2e34 | 531 | } |
1da177e4 LT |
532 | |
533 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
534 | if (r) { | |
535 | dm_put_path_selector(pst); | |
72d94861 | 536 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
537 | return r; |
538 | } | |
539 | ||
540 | pg->ps.type = pst; | |
541 | consume(as, ps_argc); | |
542 | ||
543 | return 0; | |
544 | } | |
545 | ||
546 | static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, | |
547 | struct dm_target *ti) | |
548 | { | |
549 | int r; | |
550 | struct pgpath *p; | |
551 | ||
552 | /* we need at least a path arg */ | |
553 | if (as->argc < 1) { | |
72d94861 | 554 | ti->error = "no device given"; |
1da177e4 LT |
555 | return NULL; |
556 | } | |
557 | ||
558 | p = alloc_pgpath(); | |
559 | if (!p) | |
560 | return NULL; | |
561 | ||
562 | r = dm_get_device(ti, shift(as), ti->begin, ti->len, | |
563 | dm_table_get_mode(ti->table), &p->path.dev); | |
564 | if (r) { | |
72d94861 | 565 | ti->error = "error getting device"; |
1da177e4 LT |
566 | goto bad; |
567 | } | |
568 | ||
569 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); | |
570 | if (r) { | |
571 | dm_put_device(ti, p->path.dev); | |
572 | goto bad; | |
573 | } | |
574 | ||
575 | return p; | |
576 | ||
577 | bad: | |
578 | free_pgpath(p); | |
579 | return NULL; | |
580 | } | |
581 | ||
582 | static struct priority_group *parse_priority_group(struct arg_set *as, | |
28f16c20 | 583 | struct multipath *m) |
1da177e4 LT |
584 | { |
585 | static struct param _params[] = { | |
72d94861 AK |
586 | {1, 1024, "invalid number of paths"}, |
587 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
588 | }; |
589 | ||
590 | int r; | |
591 | unsigned i, nr_selector_args, nr_params; | |
592 | struct priority_group *pg; | |
28f16c20 | 593 | struct dm_target *ti = m->ti; |
1da177e4 LT |
594 | |
595 | if (as->argc < 2) { | |
596 | as->argc = 0; | |
72d94861 | 597 | ti->error = "not enough priority group aruments"; |
1da177e4 LT |
598 | return NULL; |
599 | } | |
600 | ||
601 | pg = alloc_priority_group(); | |
602 | if (!pg) { | |
72d94861 | 603 | ti->error = "couldn't allocate priority group"; |
1da177e4 LT |
604 | return NULL; |
605 | } | |
606 | pg->m = m; | |
607 | ||
608 | r = parse_path_selector(as, pg, ti); | |
609 | if (r) | |
610 | goto bad; | |
611 | ||
612 | /* | |
613 | * read the paths | |
614 | */ | |
615 | r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error); | |
616 | if (r) | |
617 | goto bad; | |
618 | ||
619 | r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error); | |
620 | if (r) | |
621 | goto bad; | |
622 | ||
623 | nr_params = 1 + nr_selector_args; | |
624 | for (i = 0; i < pg->nr_pgpaths; i++) { | |
625 | struct pgpath *pgpath; | |
626 | struct arg_set path_args; | |
627 | ||
148acff6 MP |
628 | if (as->argc < nr_params) { |
629 | ti->error = "not enough path parameters"; | |
1da177e4 | 630 | goto bad; |
148acff6 | 631 | } |
1da177e4 LT |
632 | |
633 | path_args.argc = nr_params; | |
634 | path_args.argv = as->argv; | |
635 | ||
636 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
637 | if (!pgpath) | |
638 | goto bad; | |
639 | ||
640 | pgpath->pg = pg; | |
641 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
642 | consume(as, nr_params); | |
643 | } | |
644 | ||
645 | return pg; | |
646 | ||
647 | bad: | |
648 | free_priority_group(pg, ti); | |
649 | return NULL; | |
650 | } | |
651 | ||
28f16c20 | 652 | static int parse_hw_handler(struct arg_set *as, struct multipath *m) |
1da177e4 | 653 | { |
1da177e4 | 654 | unsigned hw_argc; |
28f16c20 | 655 | struct dm_target *ti = m->ti; |
1da177e4 LT |
656 | |
657 | static struct param _params[] = { | |
72d94861 | 658 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
659 | }; |
660 | ||
cfae5c9b | 661 | if (read_param(_params, shift(as), &hw_argc, &ti->error)) |
1da177e4 LT |
662 | return -EINVAL; |
663 | ||
664 | if (!hw_argc) | |
665 | return 0; | |
666 | ||
cfae5c9b CS |
667 | m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL); |
668 | request_module("scsi_dh_%s", m->hw_handler_name); | |
669 | if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { | |
72d94861 | 670 | ti->error = "unknown hardware handler type"; |
fe9233fb CS |
671 | kfree(m->hw_handler_name); |
672 | m->hw_handler_name = NULL; | |
1da177e4 LT |
673 | return -EINVAL; |
674 | } | |
1da177e4 LT |
675 | consume(as, hw_argc - 1); |
676 | ||
677 | return 0; | |
678 | } | |
679 | ||
28f16c20 | 680 | static int parse_features(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
681 | { |
682 | int r; | |
683 | unsigned argc; | |
28f16c20 | 684 | struct dm_target *ti = m->ti; |
c9e45581 | 685 | const char *param_name; |
1da177e4 LT |
686 | |
687 | static struct param _params[] = { | |
c9e45581 DW |
688 | {0, 3, "invalid number of feature args"}, |
689 | {1, 50, "pg_init_retries must be between 1 and 50"}, | |
1da177e4 LT |
690 | }; |
691 | ||
692 | r = read_param(_params, shift(as), &argc, &ti->error); | |
693 | if (r) | |
694 | return -EINVAL; | |
695 | ||
696 | if (!argc) | |
697 | return 0; | |
698 | ||
c9e45581 DW |
699 | do { |
700 | param_name = shift(as); | |
701 | argc--; | |
702 | ||
703 | if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { | |
704 | r = queue_if_no_path(m, 1, 0); | |
705 | continue; | |
706 | } | |
707 | ||
708 | if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && | |
709 | (argc >= 1)) { | |
710 | r = read_param(_params + 1, shift(as), | |
711 | &m->pg_init_retries, &ti->error); | |
712 | argc--; | |
713 | continue; | |
714 | } | |
715 | ||
1da177e4 | 716 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
717 | r = -EINVAL; |
718 | } while (argc && !r); | |
719 | ||
720 | return r; | |
1da177e4 LT |
721 | } |
722 | ||
723 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
724 | char **argv) | |
725 | { | |
726 | /* target parameters */ | |
727 | static struct param _params[] = { | |
72d94861 AK |
728 | {1, 1024, "invalid number of priority groups"}, |
729 | {1, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
730 | }; |
731 | ||
732 | int r; | |
733 | struct multipath *m; | |
734 | struct arg_set as; | |
735 | unsigned pg_count = 0; | |
736 | unsigned next_pg_num; | |
737 | ||
738 | as.argc = argc; | |
739 | as.argv = argv; | |
740 | ||
28f16c20 | 741 | m = alloc_multipath(ti); |
1da177e4 | 742 | if (!m) { |
72d94861 | 743 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
744 | return -EINVAL; |
745 | } | |
746 | ||
28f16c20 | 747 | r = parse_features(&as, m); |
1da177e4 LT |
748 | if (r) |
749 | goto bad; | |
750 | ||
28f16c20 | 751 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
752 | if (r) |
753 | goto bad; | |
754 | ||
755 | r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error); | |
756 | if (r) | |
757 | goto bad; | |
758 | ||
759 | r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error); | |
760 | if (r) | |
761 | goto bad; | |
762 | ||
763 | /* parse the priority groups */ | |
764 | while (as.argc) { | |
765 | struct priority_group *pg; | |
766 | ||
28f16c20 | 767 | pg = parse_priority_group(&as, m); |
1da177e4 LT |
768 | if (!pg) { |
769 | r = -EINVAL; | |
770 | goto bad; | |
771 | } | |
772 | ||
773 | m->nr_valid_paths += pg->nr_pgpaths; | |
774 | list_add_tail(&pg->list, &m->priority_groups); | |
775 | pg_count++; | |
776 | pg->pg_num = pg_count; | |
777 | if (!--next_pg_num) | |
778 | m->next_pg = pg; | |
779 | } | |
780 | ||
781 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 782 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
783 | r = -EINVAL; |
784 | goto bad; | |
785 | } | |
786 | ||
1da177e4 LT |
787 | return 0; |
788 | ||
789 | bad: | |
790 | free_multipath(m); | |
791 | return r; | |
792 | } | |
793 | ||
794 | static void multipath_dtr(struct dm_target *ti) | |
795 | { | |
796 | struct multipath *m = (struct multipath *) ti->private; | |
a044d016 | 797 | |
bab7cfc7 | 798 | flush_workqueue(kmpath_handlerd); |
a044d016 | 799 | flush_workqueue(kmultipathd); |
1da177e4 LT |
800 | free_multipath(m); |
801 | } | |
802 | ||
803 | /* | |
804 | * Map bios, recording original fields for later in case we have to resubmit | |
805 | */ | |
806 | static int multipath_map(struct dm_target *ti, struct bio *bio, | |
807 | union map_info *map_context) | |
808 | { | |
809 | int r; | |
028867ac | 810 | struct dm_mpath_io *mpio; |
1da177e4 LT |
811 | struct multipath *m = (struct multipath *) ti->private; |
812 | ||
813 | mpio = mempool_alloc(m->mpio_pool, GFP_NOIO); | |
814 | dm_bio_record(&mpio->details, bio); | |
815 | ||
816 | map_context->ptr = mpio; | |
817 | bio->bi_rw |= (1 << BIO_RW_FAILFAST); | |
818 | r = map_io(m, bio, mpio, 0); | |
45e15720 | 819 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
1da177e4 LT |
820 | mempool_free(mpio, m->mpio_pool); |
821 | ||
822 | return r; | |
823 | } | |
824 | ||
825 | /* | |
826 | * Take a path out of use. | |
827 | */ | |
828 | static int fail_path(struct pgpath *pgpath) | |
829 | { | |
830 | unsigned long flags; | |
831 | struct multipath *m = pgpath->pg->m; | |
832 | ||
833 | spin_lock_irqsave(&m->lock, flags); | |
834 | ||
835 | if (!pgpath->path.is_active) | |
836 | goto out; | |
837 | ||
72d94861 | 838 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
839 | |
840 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
841 | pgpath->path.is_active = 0; | |
842 | pgpath->fail_count++; | |
843 | ||
844 | m->nr_valid_paths--; | |
845 | ||
846 | if (pgpath == m->current_pgpath) | |
847 | m->current_pgpath = NULL; | |
848 | ||
b15546f9 MA |
849 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
850 | pgpath->path.dev->name, m->nr_valid_paths); | |
851 | ||
c557308e | 852 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
853 | |
854 | out: | |
855 | spin_unlock_irqrestore(&m->lock, flags); | |
856 | ||
857 | return 0; | |
858 | } | |
859 | ||
860 | /* | |
861 | * Reinstate a previously-failed path | |
862 | */ | |
863 | static int reinstate_path(struct pgpath *pgpath) | |
864 | { | |
865 | int r = 0; | |
866 | unsigned long flags; | |
867 | struct multipath *m = pgpath->pg->m; | |
868 | ||
869 | spin_lock_irqsave(&m->lock, flags); | |
870 | ||
871 | if (pgpath->path.is_active) | |
872 | goto out; | |
873 | ||
874 | if (!pgpath->pg->ps.type) { | |
875 | DMWARN("Reinstate path not supported by path selector %s", | |
876 | pgpath->pg->ps.type->name); | |
877 | r = -EINVAL; | |
878 | goto out; | |
879 | } | |
880 | ||
881 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
882 | if (r) | |
883 | goto out; | |
884 | ||
885 | pgpath->path.is_active = 1; | |
886 | ||
887 | m->current_pgpath = NULL; | |
c3cd4f6b | 888 | if (!m->nr_valid_paths++ && m->queue_size) |
c557308e | 889 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 890 | |
b15546f9 MA |
891 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
892 | pgpath->path.dev->name, m->nr_valid_paths); | |
893 | ||
c557308e | 894 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
895 | |
896 | out: | |
897 | spin_unlock_irqrestore(&m->lock, flags); | |
898 | ||
899 | return r; | |
900 | } | |
901 | ||
902 | /* | |
903 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
904 | */ | |
905 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
906 | action_fn action) | |
907 | { | |
908 | int r = 0; | |
909 | struct pgpath *pgpath; | |
910 | struct priority_group *pg; | |
911 | ||
912 | list_for_each_entry(pg, &m->priority_groups, list) { | |
913 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
914 | if (pgpath->path.dev == dev) | |
915 | r = action(pgpath); | |
916 | } | |
917 | } | |
918 | ||
919 | return r; | |
920 | } | |
921 | ||
922 | /* | |
923 | * Temporarily try to avoid having to use the specified PG | |
924 | */ | |
925 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
926 | int bypassed) | |
927 | { | |
928 | unsigned long flags; | |
929 | ||
930 | spin_lock_irqsave(&m->lock, flags); | |
931 | ||
932 | pg->bypassed = bypassed; | |
933 | m->current_pgpath = NULL; | |
934 | m->current_pg = NULL; | |
935 | ||
936 | spin_unlock_irqrestore(&m->lock, flags); | |
937 | ||
c557308e | 938 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
939 | } |
940 | ||
941 | /* | |
942 | * Switch to using the specified PG from the next I/O that gets mapped | |
943 | */ | |
944 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
945 | { | |
946 | struct priority_group *pg; | |
947 | unsigned pgnum; | |
948 | unsigned long flags; | |
949 | ||
950 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
951 | (pgnum > m->nr_priority_groups)) { | |
952 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
953 | return -EINVAL; | |
954 | } | |
955 | ||
956 | spin_lock_irqsave(&m->lock, flags); | |
957 | list_for_each_entry(pg, &m->priority_groups, list) { | |
958 | pg->bypassed = 0; | |
959 | if (--pgnum) | |
960 | continue; | |
961 | ||
962 | m->current_pgpath = NULL; | |
963 | m->current_pg = NULL; | |
964 | m->next_pg = pg; | |
965 | } | |
966 | spin_unlock_irqrestore(&m->lock, flags); | |
967 | ||
c557308e | 968 | queue_work(kmultipathd, &m->trigger_event); |
1da177e4 LT |
969 | return 0; |
970 | } | |
971 | ||
972 | /* | |
973 | * Set/clear bypassed status of a PG. | |
974 | * PGs are numbered upwards from 1 in the order they were declared. | |
975 | */ | |
976 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
977 | { | |
978 | struct priority_group *pg; | |
979 | unsigned pgnum; | |
980 | ||
981 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
982 | (pgnum > m->nr_priority_groups)) { | |
983 | DMWARN("invalid PG number supplied to bypass_pg"); | |
984 | return -EINVAL; | |
985 | } | |
986 | ||
987 | list_for_each_entry(pg, &m->priority_groups, list) { | |
988 | if (!--pgnum) | |
989 | break; | |
990 | } | |
991 | ||
992 | bypass_pg(m, pg, bypassed); | |
993 | return 0; | |
994 | } | |
995 | ||
c9e45581 DW |
996 | /* |
997 | * Should we retry pg_init immediately? | |
998 | */ | |
999 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1000 | { | |
1001 | unsigned long flags; | |
1002 | int limit_reached = 0; | |
1003 | ||
1004 | spin_lock_irqsave(&m->lock, flags); | |
1005 | ||
1006 | if (m->pg_init_count <= m->pg_init_retries) | |
1007 | m->pg_init_required = 1; | |
1008 | else | |
1009 | limit_reached = 1; | |
1010 | ||
1011 | spin_unlock_irqrestore(&m->lock, flags); | |
1012 | ||
1013 | return limit_reached; | |
1014 | } | |
1015 | ||
cfae5c9b CS |
1016 | static void pg_init_done(struct dm_path *path, int errors) |
1017 | { | |
1018 | struct pgpath *pgpath = path_to_pgpath(path); | |
1019 | struct priority_group *pg = pgpath->pg; | |
1020 | struct multipath *m = pg->m; | |
1021 | unsigned long flags; | |
1022 | ||
1023 | /* device or driver problems */ | |
1024 | switch (errors) { | |
1025 | case SCSI_DH_OK: | |
1026 | break; | |
1027 | case SCSI_DH_NOSYS: | |
1028 | if (!m->hw_handler_name) { | |
1029 | errors = 0; | |
1030 | break; | |
1031 | } | |
1032 | DMERR("Cannot failover device because scsi_dh_%s was not " | |
1033 | "loaded.", m->hw_handler_name); | |
1034 | /* | |
1035 | * Fail path for now, so we do not ping pong | |
1036 | */ | |
1037 | fail_path(pgpath); | |
1038 | break; | |
1039 | case SCSI_DH_DEV_TEMP_BUSY: | |
1040 | /* | |
1041 | * Probably doing something like FW upgrade on the | |
1042 | * controller so try the other pg. | |
1043 | */ | |
1044 | bypass_pg(m, pg, 1); | |
1045 | break; | |
1046 | /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */ | |
1047 | case SCSI_DH_RETRY: | |
1048 | case SCSI_DH_IMM_RETRY: | |
1049 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1050 | if (pg_init_limit_reached(m, pgpath)) | |
1051 | fail_path(pgpath); | |
1052 | errors = 0; | |
1053 | break; | |
1054 | default: | |
1055 | /* | |
1056 | * We probably do not want to fail the path for a device | |
1057 | * error, but this is what the old dm did. In future | |
1058 | * patches we can do more advanced handling. | |
1059 | */ | |
1060 | fail_path(pgpath); | |
1061 | } | |
1062 | ||
1063 | spin_lock_irqsave(&m->lock, flags); | |
1064 | if (errors) { | |
1065 | DMERR("Could not failover device. Error %d.", errors); | |
1066 | m->current_pgpath = NULL; | |
1067 | m->current_pg = NULL; | |
1068 | } else if (!m->pg_init_required) { | |
1069 | m->queue_io = 0; | |
1070 | pg->bypassed = 0; | |
1071 | } | |
1072 | ||
1073 | m->pg_init_in_progress = 0; | |
1074 | queue_work(kmultipathd, &m->process_queued_ios); | |
1075 | spin_unlock_irqrestore(&m->lock, flags); | |
1076 | } | |
1077 | ||
bab7cfc7 CS |
1078 | static void activate_path(struct work_struct *work) |
1079 | { | |
1080 | int ret; | |
1081 | struct multipath *m = | |
1082 | container_of(work, struct multipath, activate_path); | |
1083 | struct dm_path *path = &m->current_pgpath->path; | |
1084 | ||
1085 | ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev)); | |
1086 | pg_init_done(path, ret); | |
1087 | } | |
1088 | ||
1da177e4 LT |
1089 | /* |
1090 | * end_io handling | |
1091 | */ | |
1092 | static int do_end_io(struct multipath *m, struct bio *bio, | |
028867ac | 1093 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1094 | { |
640eb3b0 | 1095 | unsigned long flags; |
1da177e4 LT |
1096 | |
1097 | if (!error) | |
1098 | return 0; /* I/O complete */ | |
1099 | ||
4f58802f LMB |
1100 | if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio)) |
1101 | return error; | |
1102 | ||
f6a80ea8 AK |
1103 | if (error == -EOPNOTSUPP) |
1104 | return error; | |
1105 | ||
640eb3b0 | 1106 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 1107 | if (!m->nr_valid_paths) { |
45e15720 KU |
1108 | if (__must_push_back(m)) { |
1109 | spin_unlock_irqrestore(&m->lock, flags); | |
1110 | return DM_ENDIO_REQUEUE; | |
1111 | } else if (!m->queue_if_no_path) { | |
640eb3b0 | 1112 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1113 | return -EIO; |
1114 | } else { | |
640eb3b0 | 1115 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1116 | goto requeue; |
1117 | } | |
1118 | } | |
640eb3b0 | 1119 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1120 | |
cfae5c9b CS |
1121 | if (mpio->pgpath) |
1122 | fail_path(mpio->pgpath); | |
1da177e4 LT |
1123 | |
1124 | requeue: | |
1125 | dm_bio_restore(&mpio->details, bio); | |
1126 | ||
1127 | /* queue for the daemon to resubmit or fail */ | |
640eb3b0 | 1128 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
1129 | bio_list_add(&m->queued_ios, bio); |
1130 | m->queue_size++; | |
1131 | if (!m->queue_io) | |
c557308e | 1132 | queue_work(kmultipathd, &m->process_queued_ios); |
640eb3b0 | 1133 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1134 | |
d2a7ad29 | 1135 | return DM_ENDIO_INCOMPLETE; /* io not complete */ |
1da177e4 LT |
1136 | } |
1137 | ||
1138 | static int multipath_end_io(struct dm_target *ti, struct bio *bio, | |
1139 | int error, union map_info *map_context) | |
1140 | { | |
028867ac AK |
1141 | struct multipath *m = ti->private; |
1142 | struct dm_mpath_io *mpio = map_context->ptr; | |
1da177e4 LT |
1143 | struct pgpath *pgpath = mpio->pgpath; |
1144 | struct path_selector *ps; | |
1145 | int r; | |
1146 | ||
1147 | r = do_end_io(m, bio, error, mpio); | |
1148 | if (pgpath) { | |
1149 | ps = &pgpath->pg->ps; | |
1150 | if (ps->type->end_io) | |
1151 | ps->type->end_io(ps, &pgpath->path); | |
1152 | } | |
d2a7ad29 | 1153 | if (r != DM_ENDIO_INCOMPLETE) |
1da177e4 LT |
1154 | mempool_free(mpio, m->mpio_pool); |
1155 | ||
1156 | return r; | |
1157 | } | |
1158 | ||
1159 | /* | |
1160 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1161 | * the last path fails we must error any remaining I/O. |
1162 | * Note that if the freeze_bdev fails while suspending, the | |
1163 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1164 | */ |
1165 | static void multipath_presuspend(struct dm_target *ti) | |
1166 | { | |
1167 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1168 | |
485ef69e | 1169 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1170 | } |
1171 | ||
436d4108 AK |
1172 | /* |
1173 | * Restore the queue_if_no_path setting. | |
1174 | */ | |
1da177e4 LT |
1175 | static void multipath_resume(struct dm_target *ti) |
1176 | { | |
1177 | struct multipath *m = (struct multipath *) ti->private; | |
1178 | unsigned long flags; | |
1179 | ||
1180 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1181 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1182 | spin_unlock_irqrestore(&m->lock, flags); |
1183 | } | |
1184 | ||
1185 | /* | |
1186 | * Info output has the following format: | |
1187 | * num_multipath_feature_args [multipath_feature_args]* | |
1188 | * num_handler_status_args [handler_status_args]* | |
1189 | * num_groups init_group_number | |
1190 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1191 | * num_paths num_selector_args | |
1192 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1193 | * | |
1194 | * Table output has the following format (identical to the constructor string): | |
1195 | * num_feature_args [features_args]* | |
1196 | * num_handler_args hw_handler [hw_handler_args]* | |
1197 | * num_groups init_group_number | |
1198 | * [priority selector-name num_ps_args [ps_args]* | |
1199 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1200 | */ | |
1201 | static int multipath_status(struct dm_target *ti, status_type_t type, | |
1202 | char *result, unsigned int maxlen) | |
1203 | { | |
1204 | int sz = 0; | |
1205 | unsigned long flags; | |
1206 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1207 | struct priority_group *pg; |
1208 | struct pgpath *p; | |
1209 | unsigned pg_num; | |
1210 | char state; | |
1211 | ||
1212 | spin_lock_irqsave(&m->lock, flags); | |
1213 | ||
1214 | /* Features */ | |
1215 | if (type == STATUSTYPE_INFO) | |
c9e45581 DW |
1216 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
1217 | else { | |
1218 | DMEMIT("%u ", m->queue_if_no_path + | |
1219 | (m->pg_init_retries > 0) * 2); | |
1220 | if (m->queue_if_no_path) | |
1221 | DMEMIT("queue_if_no_path "); | |
1222 | if (m->pg_init_retries) | |
1223 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
1224 | } | |
1da177e4 | 1225 | |
cfae5c9b | 1226 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1227 | DMEMIT("0 "); |
1228 | else | |
cfae5c9b | 1229 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1230 | |
1231 | DMEMIT("%u ", m->nr_priority_groups); | |
1232 | ||
1233 | if (m->next_pg) | |
1234 | pg_num = m->next_pg->pg_num; | |
1235 | else if (m->current_pg) | |
1236 | pg_num = m->current_pg->pg_num; | |
1237 | else | |
1238 | pg_num = 1; | |
1239 | ||
1240 | DMEMIT("%u ", pg_num); | |
1241 | ||
1242 | switch (type) { | |
1243 | case STATUSTYPE_INFO: | |
1244 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1245 | if (pg->bypassed) | |
1246 | state = 'D'; /* Disabled */ | |
1247 | else if (pg == m->current_pg) | |
1248 | state = 'A'; /* Currently Active */ | |
1249 | else | |
1250 | state = 'E'; /* Enabled */ | |
1251 | ||
1252 | DMEMIT("%c ", state); | |
1253 | ||
1254 | if (pg->ps.type->status) | |
1255 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1256 | result + sz, | |
1257 | maxlen - sz); | |
1258 | else | |
1259 | DMEMIT("0 "); | |
1260 | ||
1261 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1262 | pg->ps.type->info_args); | |
1263 | ||
1264 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1265 | DMEMIT("%s %s %u ", p->path.dev->name, | |
1266 | p->path.is_active ? "A" : "F", | |
1267 | p->fail_count); | |
1268 | if (pg->ps.type->status) | |
1269 | sz += pg->ps.type->status(&pg->ps, | |
1270 | &p->path, type, result + sz, | |
1271 | maxlen - sz); | |
1272 | } | |
1273 | } | |
1274 | break; | |
1275 | ||
1276 | case STATUSTYPE_TABLE: | |
1277 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1278 | DMEMIT("%s ", pg->ps.type->name); | |
1279 | ||
1280 | if (pg->ps.type->status) | |
1281 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1282 | result + sz, | |
1283 | maxlen - sz); | |
1284 | else | |
1285 | DMEMIT("0 "); | |
1286 | ||
1287 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1288 | pg->ps.type->table_args); | |
1289 | ||
1290 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1291 | DMEMIT("%s ", p->path.dev->name); | |
1292 | if (pg->ps.type->status) | |
1293 | sz += pg->ps.type->status(&pg->ps, | |
1294 | &p->path, type, result + sz, | |
1295 | maxlen - sz); | |
1296 | } | |
1297 | } | |
1298 | break; | |
1299 | } | |
1300 | ||
1301 | spin_unlock_irqrestore(&m->lock, flags); | |
1302 | ||
1303 | return 0; | |
1304 | } | |
1305 | ||
1306 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1307 | { | |
1308 | int r; | |
1309 | struct dm_dev *dev; | |
1310 | struct multipath *m = (struct multipath *) ti->private; | |
1311 | action_fn action; | |
1312 | ||
1313 | if (argc == 1) { | |
1314 | if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) | |
485ef69e | 1315 | return queue_if_no_path(m, 1, 0); |
1da177e4 | 1316 | else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) |
485ef69e | 1317 | return queue_if_no_path(m, 0, 0); |
1da177e4 LT |
1318 | } |
1319 | ||
1320 | if (argc != 2) | |
1321 | goto error; | |
1322 | ||
1323 | if (!strnicmp(argv[0], MESG_STR("disable_group"))) | |
1324 | return bypass_pg_num(m, argv[1], 1); | |
1325 | else if (!strnicmp(argv[0], MESG_STR("enable_group"))) | |
1326 | return bypass_pg_num(m, argv[1], 0); | |
1327 | else if (!strnicmp(argv[0], MESG_STR("switch_group"))) | |
1328 | return switch_pg_num(m, argv[1]); | |
1329 | else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) | |
1330 | action = reinstate_path; | |
1331 | else if (!strnicmp(argv[0], MESG_STR("fail_path"))) | |
1332 | action = fail_path; | |
1333 | else | |
1334 | goto error; | |
1335 | ||
1336 | r = dm_get_device(ti, argv[1], ti->begin, ti->len, | |
1337 | dm_table_get_mode(ti->table), &dev); | |
1338 | if (r) { | |
72d94861 | 1339 | DMWARN("message: error getting device %s", |
1da177e4 LT |
1340 | argv[1]); |
1341 | return -EINVAL; | |
1342 | } | |
1343 | ||
1344 | r = action_dev(m, dev, action); | |
1345 | ||
1346 | dm_put_device(ti, dev); | |
1347 | ||
1348 | return r; | |
1349 | ||
1350 | error: | |
1351 | DMWARN("Unrecognised multipath message received."); | |
1352 | return -EINVAL; | |
1353 | } | |
1354 | ||
9af4aa30 MB |
1355 | static int multipath_ioctl(struct dm_target *ti, struct inode *inode, |
1356 | struct file *filp, unsigned int cmd, | |
1357 | unsigned long arg) | |
1358 | { | |
1359 | struct multipath *m = (struct multipath *) ti->private; | |
1360 | struct block_device *bdev = NULL; | |
1361 | unsigned long flags; | |
e90dae1f MB |
1362 | struct file fake_file = {}; |
1363 | struct dentry fake_dentry = {}; | |
9af4aa30 MB |
1364 | int r = 0; |
1365 | ||
c649bb9c | 1366 | fake_file.f_path.dentry = &fake_dentry; |
e90dae1f | 1367 | |
9af4aa30 MB |
1368 | spin_lock_irqsave(&m->lock, flags); |
1369 | ||
1370 | if (!m->current_pgpath) | |
1371 | __choose_pgpath(m); | |
1372 | ||
e90dae1f | 1373 | if (m->current_pgpath) { |
9af4aa30 | 1374 | bdev = m->current_pgpath->path.dev->bdev; |
e90dae1f MB |
1375 | fake_dentry.d_inode = bdev->bd_inode; |
1376 | fake_file.f_mode = m->current_pgpath->path.dev->mode; | |
1377 | } | |
9af4aa30 MB |
1378 | |
1379 | if (m->queue_io) | |
1380 | r = -EAGAIN; | |
1381 | else if (!bdev) | |
1382 | r = -EIO; | |
1383 | ||
1384 | spin_unlock_irqrestore(&m->lock, flags); | |
1385 | ||
e90dae1f MB |
1386 | return r ? : blkdev_driver_ioctl(bdev->bd_inode, &fake_file, |
1387 | bdev->bd_disk, cmd, arg); | |
9af4aa30 MB |
1388 | } |
1389 | ||
1da177e4 LT |
1390 | /*----------------------------------------------------------------- |
1391 | * Module setup | |
1392 | *---------------------------------------------------------------*/ | |
1393 | static struct target_type multipath_target = { | |
1394 | .name = "multipath", | |
9af4aa30 | 1395 | .version = {1, 0, 5}, |
1da177e4 LT |
1396 | .module = THIS_MODULE, |
1397 | .ctr = multipath_ctr, | |
1398 | .dtr = multipath_dtr, | |
1399 | .map = multipath_map, | |
1400 | .end_io = multipath_end_io, | |
1401 | .presuspend = multipath_presuspend, | |
1402 | .resume = multipath_resume, | |
1403 | .status = multipath_status, | |
1404 | .message = multipath_message, | |
9af4aa30 | 1405 | .ioctl = multipath_ioctl, |
1da177e4 LT |
1406 | }; |
1407 | ||
1408 | static int __init dm_multipath_init(void) | |
1409 | { | |
1410 | int r; | |
1411 | ||
1412 | /* allocate a slab for the dm_ios */ | |
028867ac | 1413 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1414 | if (!_mpio_cache) |
1415 | return -ENOMEM; | |
1416 | ||
1417 | r = dm_register_target(&multipath_target); | |
1418 | if (r < 0) { | |
0cd33124 | 1419 | DMERR("register failed %d", r); |
1da177e4 LT |
1420 | kmem_cache_destroy(_mpio_cache); |
1421 | return -EINVAL; | |
1422 | } | |
1423 | ||
c557308e AK |
1424 | kmultipathd = create_workqueue("kmpathd"); |
1425 | if (!kmultipathd) { | |
0cd33124 | 1426 | DMERR("failed to create workqueue kmpathd"); |
c557308e AK |
1427 | dm_unregister_target(&multipath_target); |
1428 | kmem_cache_destroy(_mpio_cache); | |
1429 | return -ENOMEM; | |
1430 | } | |
1431 | ||
bab7cfc7 CS |
1432 | /* |
1433 | * A separate workqueue is used to handle the device handlers | |
1434 | * to avoid overloading existing workqueue. Overloading the | |
1435 | * old workqueue would also create a bottleneck in the | |
1436 | * path of the storage hardware device activation. | |
1437 | */ | |
1438 | kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd"); | |
1439 | if (!kmpath_handlerd) { | |
1440 | DMERR("failed to create workqueue kmpath_handlerd"); | |
1441 | destroy_workqueue(kmultipathd); | |
1442 | dm_unregister_target(&multipath_target); | |
1443 | kmem_cache_destroy(_mpio_cache); | |
1444 | return -ENOMEM; | |
1445 | } | |
1446 | ||
72d94861 | 1447 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1448 | multipath_target.version[0], multipath_target.version[1], |
1449 | multipath_target.version[2]); | |
1450 | ||
1451 | return r; | |
1452 | } | |
1453 | ||
1454 | static void __exit dm_multipath_exit(void) | |
1455 | { | |
1456 | int r; | |
1457 | ||
bab7cfc7 | 1458 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1459 | destroy_workqueue(kmultipathd); |
1460 | ||
1da177e4 LT |
1461 | r = dm_unregister_target(&multipath_target); |
1462 | if (r < 0) | |
0cd33124 | 1463 | DMERR("target unregister failed %d", r); |
1da177e4 LT |
1464 | kmem_cache_destroy(_mpio_cache); |
1465 | } | |
1466 | ||
1da177e4 LT |
1467 | module_init(dm_multipath_init); |
1468 | module_exit(dm_multipath_exit); | |
1469 | ||
1470 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1471 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1472 | MODULE_LICENSE("GPL"); |