Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software Limited. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
586e80e6 MP |
8 | #include <linux/device-mapper.h> |
9 | ||
1da177e4 | 10 | #include "dm-path-selector.h" |
1da177e4 LT |
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> | |
cfae5c9b | 23 | #include <scsi/scsi_dh.h> |
1da177e4 LT |
24 | #include <asm/atomic.h> |
25 | ||
72d94861 | 26 | #define DM_MSG_PREFIX "multipath" |
1da177e4 LT |
27 | #define MESG_STR(x) x, sizeof(x) |
28 | ||
29 | /* Path properties */ | |
30 | struct pgpath { | |
31 | struct list_head list; | |
32 | ||
33 | struct priority_group *pg; /* Owning PG */ | |
6680073d | 34 | unsigned is_active; /* Path status */ |
1da177e4 LT |
35 | unsigned fail_count; /* Cumulative failure count */ |
36 | ||
c922d5f7 | 37 | struct dm_path path; |
224cb3e9 | 38 | struct work_struct deactivate_path; |
1da177e4 LT |
39 | }; |
40 | ||
41 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
42 | ||
43 | /* | |
44 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
45 | * Each has a path selector which controls which path gets used. | |
46 | */ | |
47 | struct priority_group { | |
48 | struct list_head list; | |
49 | ||
50 | struct multipath *m; /* Owning multipath instance */ | |
51 | struct path_selector ps; | |
52 | ||
53 | unsigned pg_num; /* Reference number */ | |
54 | unsigned bypassed; /* Temporarily bypass this PG? */ | |
55 | ||
56 | unsigned nr_pgpaths; /* Number of paths in PG */ | |
57 | struct list_head pgpaths; | |
58 | }; | |
59 | ||
60 | /* Multipath context */ | |
61 | struct multipath { | |
62 | struct list_head list; | |
63 | struct dm_target *ti; | |
64 | ||
65 | spinlock_t lock; | |
66 | ||
cfae5c9b | 67 | const char *hw_handler_name; |
bab7cfc7 | 68 | struct work_struct activate_path; |
7253a334 | 69 | struct pgpath *pgpath_to_activate; |
1da177e4 LT |
70 | unsigned nr_priority_groups; |
71 | struct list_head priority_groups; | |
72 | unsigned pg_init_required; /* pg_init needs calling? */ | |
c3cd4f6b | 73 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
1da177e4 LT |
74 | |
75 | unsigned nr_valid_paths; /* Total number of usable paths */ | |
76 | struct pgpath *current_pgpath; | |
77 | struct priority_group *current_pg; | |
78 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
79 | unsigned repeat_count; /* I/Os left before calling PS again */ | |
80 | ||
81 | unsigned queue_io; /* Must we queue all I/O? */ | |
82 | unsigned queue_if_no_path; /* Queue I/O if last path fails? */ | |
436d4108 | 83 | unsigned saved_queue_if_no_path;/* Saved state during suspension */ |
c9e45581 DW |
84 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
85 | unsigned pg_init_count; /* Number of times pg_init called */ | |
1da177e4 LT |
86 | |
87 | struct work_struct process_queued_ios; | |
88 | struct bio_list queued_ios; | |
89 | unsigned queue_size; | |
90 | ||
91 | struct work_struct trigger_event; | |
92 | ||
93 | /* | |
028867ac | 94 | * We must use a mempool of dm_mpath_io structs so that we |
1da177e4 LT |
95 | * can resubmit bios on error. |
96 | */ | |
97 | mempool_t *mpio_pool; | |
98 | }; | |
99 | ||
100 | /* | |
101 | * Context information attached to each bio we process. | |
102 | */ | |
028867ac | 103 | struct dm_mpath_io { |
1da177e4 LT |
104 | struct pgpath *pgpath; |
105 | struct dm_bio_details details; | |
106 | }; | |
107 | ||
108 | typedef int (*action_fn) (struct pgpath *pgpath); | |
109 | ||
110 | #define MIN_IOS 256 /* Mempool size */ | |
111 | ||
e18b890b | 112 | static struct kmem_cache *_mpio_cache; |
1da177e4 | 113 | |
bab7cfc7 | 114 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 DH |
115 | static void process_queued_ios(struct work_struct *work); |
116 | static void trigger_event(struct work_struct *work); | |
bab7cfc7 | 117 | static void activate_path(struct work_struct *work); |
224cb3e9 | 118 | static void deactivate_path(struct work_struct *work); |
1da177e4 LT |
119 | |
120 | ||
121 | /*----------------------------------------------- | |
122 | * Allocation routines | |
123 | *-----------------------------------------------*/ | |
124 | ||
125 | static struct pgpath *alloc_pgpath(void) | |
126 | { | |
e69fae56 | 127 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 128 | |
224cb3e9 | 129 | if (pgpath) { |
6680073d | 130 | pgpath->is_active = 1; |
224cb3e9 MA |
131 | INIT_WORK(&pgpath->deactivate_path, deactivate_path); |
132 | } | |
1da177e4 LT |
133 | |
134 | return pgpath; | |
135 | } | |
136 | ||
028867ac | 137 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
138 | { |
139 | kfree(pgpath); | |
140 | } | |
141 | ||
224cb3e9 MA |
142 | static void deactivate_path(struct work_struct *work) |
143 | { | |
144 | struct pgpath *pgpath = | |
145 | container_of(work, struct pgpath, deactivate_path); | |
146 | ||
147 | blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue); | |
148 | } | |
149 | ||
1da177e4 LT |
150 | static struct priority_group *alloc_priority_group(void) |
151 | { | |
152 | struct priority_group *pg; | |
153 | ||
e69fae56 | 154 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 155 | |
e69fae56 MM |
156 | if (pg) |
157 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
158 | |
159 | return pg; | |
160 | } | |
161 | ||
162 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
163 | { | |
7253a334 | 164 | unsigned long flags; |
1da177e4 | 165 | struct pgpath *pgpath, *tmp; |
ae11b1b3 | 166 | struct multipath *m = ti->private; |
1da177e4 LT |
167 | |
168 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
169 | list_del(&pgpath->list); | |
ae11b1b3 HR |
170 | if (m->hw_handler_name) |
171 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); | |
1da177e4 | 172 | dm_put_device(ti, pgpath->path.dev); |
7253a334 CS |
173 | spin_lock_irqsave(&m->lock, flags); |
174 | if (m->pgpath_to_activate == pgpath) | |
175 | m->pgpath_to_activate = NULL; | |
176 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
177 | free_pgpath(pgpath); |
178 | } | |
179 | } | |
180 | ||
181 | static void free_priority_group(struct priority_group *pg, | |
182 | struct dm_target *ti) | |
183 | { | |
184 | struct path_selector *ps = &pg->ps; | |
185 | ||
186 | if (ps->type) { | |
187 | ps->type->destroy(ps); | |
188 | dm_put_path_selector(ps->type); | |
189 | } | |
190 | ||
191 | free_pgpaths(&pg->pgpaths, ti); | |
192 | kfree(pg); | |
193 | } | |
194 | ||
28f16c20 | 195 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
196 | { |
197 | struct multipath *m; | |
198 | ||
e69fae56 | 199 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 200 | if (m) { |
1da177e4 LT |
201 | INIT_LIST_HEAD(&m->priority_groups); |
202 | spin_lock_init(&m->lock); | |
203 | m->queue_io = 1; | |
c4028958 DH |
204 | INIT_WORK(&m->process_queued_ios, process_queued_ios); |
205 | INIT_WORK(&m->trigger_event, trigger_event); | |
bab7cfc7 | 206 | INIT_WORK(&m->activate_path, activate_path); |
93d2341c | 207 | m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); |
1da177e4 LT |
208 | if (!m->mpio_pool) { |
209 | kfree(m); | |
210 | return NULL; | |
211 | } | |
28f16c20 MM |
212 | m->ti = ti; |
213 | ti->private = m; | |
1da177e4 LT |
214 | } |
215 | ||
216 | return m; | |
217 | } | |
218 | ||
219 | static void free_multipath(struct multipath *m) | |
220 | { | |
221 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
222 | |
223 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
224 | list_del(&pg->list); | |
225 | free_priority_group(pg, m->ti); | |
226 | } | |
227 | ||
cfae5c9b | 228 | kfree(m->hw_handler_name); |
1da177e4 LT |
229 | mempool_destroy(m->mpio_pool); |
230 | kfree(m); | |
231 | } | |
232 | ||
233 | ||
234 | /*----------------------------------------------- | |
235 | * Path selection | |
236 | *-----------------------------------------------*/ | |
237 | ||
238 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) | |
239 | { | |
1da177e4 LT |
240 | m->current_pg = pgpath->pg; |
241 | ||
242 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 243 | if (m->hw_handler_name) { |
1da177e4 LT |
244 | m->pg_init_required = 1; |
245 | m->queue_io = 1; | |
246 | } else { | |
247 | m->pg_init_required = 0; | |
248 | m->queue_io = 0; | |
249 | } | |
c9e45581 DW |
250 | |
251 | m->pg_init_count = 0; | |
1da177e4 LT |
252 | } |
253 | ||
254 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg) | |
255 | { | |
c922d5f7 | 256 | struct dm_path *path; |
1da177e4 LT |
257 | |
258 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count); | |
259 | if (!path) | |
260 | return -ENXIO; | |
261 | ||
262 | m->current_pgpath = path_to_pgpath(path); | |
263 | ||
264 | if (m->current_pg != pg) | |
265 | __switch_pg(m, m->current_pgpath); | |
266 | ||
267 | return 0; | |
268 | } | |
269 | ||
270 | static void __choose_pgpath(struct multipath *m) | |
271 | { | |
272 | struct priority_group *pg; | |
273 | unsigned bypassed = 1; | |
274 | ||
275 | if (!m->nr_valid_paths) | |
276 | goto failed; | |
277 | ||
278 | /* Were we instructed to switch PG? */ | |
279 | if (m->next_pg) { | |
280 | pg = m->next_pg; | |
281 | m->next_pg = NULL; | |
282 | if (!__choose_path_in_pg(m, pg)) | |
283 | return; | |
284 | } | |
285 | ||
286 | /* Don't change PG until it has no remaining paths */ | |
287 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg)) | |
288 | return; | |
289 | ||
290 | /* | |
291 | * Loop through priority groups until we find a valid path. | |
292 | * First time we skip PGs marked 'bypassed'. | |
293 | * Second time we only try the ones we skipped. | |
294 | */ | |
295 | do { | |
296 | list_for_each_entry(pg, &m->priority_groups, list) { | |
297 | if (pg->bypassed == bypassed) | |
298 | continue; | |
299 | if (!__choose_path_in_pg(m, pg)) | |
300 | return; | |
301 | } | |
302 | } while (bypassed--); | |
303 | ||
304 | failed: | |
305 | m->current_pgpath = NULL; | |
306 | m->current_pg = NULL; | |
307 | } | |
308 | ||
45e15720 KU |
309 | /* |
310 | * Check whether bios must be queued in the device-mapper core rather | |
311 | * than here in the target. | |
312 | * | |
313 | * m->lock must be held on entry. | |
314 | * | |
315 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
316 | * same value then we are not between multipath_presuspend() | |
317 | * and multipath_resume() calls and we have no need to check | |
318 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
319 | */ | |
320 | static int __must_push_back(struct multipath *m) | |
321 | { | |
322 | return (m->queue_if_no_path != m->saved_queue_if_no_path && | |
323 | dm_noflush_suspending(m->ti)); | |
324 | } | |
325 | ||
028867ac AK |
326 | static int map_io(struct multipath *m, struct bio *bio, |
327 | struct dm_mpath_io *mpio, unsigned was_queued) | |
1da177e4 | 328 | { |
d2a7ad29 | 329 | int r = DM_MAPIO_REMAPPED; |
1da177e4 LT |
330 | unsigned long flags; |
331 | struct pgpath *pgpath; | |
332 | ||
333 | spin_lock_irqsave(&m->lock, flags); | |
334 | ||
335 | /* Do we need to select a new pgpath? */ | |
336 | if (!m->current_pgpath || | |
337 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
338 | __choose_pgpath(m); | |
339 | ||
340 | pgpath = m->current_pgpath; | |
341 | ||
342 | if (was_queued) | |
343 | m->queue_size--; | |
344 | ||
345 | if ((pgpath && m->queue_io) || | |
436d4108 | 346 | (!pgpath && m->queue_if_no_path)) { |
1da177e4 LT |
347 | /* Queue for the daemon to resubmit */ |
348 | bio_list_add(&m->queued_ios, bio); | |
349 | m->queue_size++; | |
c3cd4f6b AK |
350 | if ((m->pg_init_required && !m->pg_init_in_progress) || |
351 | !m->queue_io) | |
c557308e | 352 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 353 | pgpath = NULL; |
d2a7ad29 | 354 | r = DM_MAPIO_SUBMITTED; |
45e15720 | 355 | } else if (pgpath) |
1da177e4 | 356 | bio->bi_bdev = pgpath->path.dev->bdev; |
45e15720 KU |
357 | else if (__must_push_back(m)) |
358 | r = DM_MAPIO_REQUEUE; | |
359 | else | |
360 | r = -EIO; /* Failed */ | |
1da177e4 LT |
361 | |
362 | mpio->pgpath = pgpath; | |
363 | ||
364 | spin_unlock_irqrestore(&m->lock, flags); | |
365 | ||
366 | return r; | |
367 | } | |
368 | ||
369 | /* | |
370 | * If we run out of usable paths, should we queue I/O or error it? | |
371 | */ | |
485ef69e AK |
372 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
373 | unsigned save_old_value) | |
1da177e4 LT |
374 | { |
375 | unsigned long flags; | |
376 | ||
377 | spin_lock_irqsave(&m->lock, flags); | |
378 | ||
485ef69e AK |
379 | if (save_old_value) |
380 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
381 | else | |
382 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 383 | m->queue_if_no_path = queue_if_no_path; |
c3cd4f6b | 384 | if (!m->queue_if_no_path && m->queue_size) |
c557308e | 385 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 LT |
386 | |
387 | spin_unlock_irqrestore(&m->lock, flags); | |
388 | ||
389 | return 0; | |
390 | } | |
391 | ||
392 | /*----------------------------------------------------------------- | |
393 | * The multipath daemon is responsible for resubmitting queued ios. | |
394 | *---------------------------------------------------------------*/ | |
395 | ||
396 | static void dispatch_queued_ios(struct multipath *m) | |
397 | { | |
398 | int r; | |
399 | unsigned long flags; | |
400 | struct bio *bio = NULL, *next; | |
028867ac | 401 | struct dm_mpath_io *mpio; |
1da177e4 LT |
402 | union map_info *info; |
403 | ||
404 | spin_lock_irqsave(&m->lock, flags); | |
405 | bio = bio_list_get(&m->queued_ios); | |
406 | spin_unlock_irqrestore(&m->lock, flags); | |
407 | ||
408 | while (bio) { | |
409 | next = bio->bi_next; | |
410 | bio->bi_next = NULL; | |
411 | ||
412 | info = dm_get_mapinfo(bio); | |
413 | mpio = info->ptr; | |
414 | ||
415 | r = map_io(m, bio, mpio, 1); | |
416 | if (r < 0) | |
6712ecf8 | 417 | bio_endio(bio, r); |
d2a7ad29 | 418 | else if (r == DM_MAPIO_REMAPPED) |
1da177e4 | 419 | generic_make_request(bio); |
45e15720 | 420 | else if (r == DM_MAPIO_REQUEUE) |
6712ecf8 | 421 | bio_endio(bio, -EIO); |
1da177e4 LT |
422 | |
423 | bio = next; | |
424 | } | |
425 | } | |
426 | ||
c4028958 | 427 | static void process_queued_ios(struct work_struct *work) |
1da177e4 | 428 | { |
c4028958 DH |
429 | struct multipath *m = |
430 | container_of(work, struct multipath, process_queued_ios); | |
c3cd4f6b AK |
431 | struct pgpath *pgpath = NULL; |
432 | unsigned init_required = 0, must_queue = 1; | |
1da177e4 LT |
433 | unsigned long flags; |
434 | ||
435 | spin_lock_irqsave(&m->lock, flags); | |
436 | ||
c3cd4f6b AK |
437 | if (!m->queue_size) |
438 | goto out; | |
439 | ||
1da177e4 LT |
440 | if (!m->current_pgpath) |
441 | __choose_pgpath(m); | |
442 | ||
443 | pgpath = m->current_pgpath; | |
444 | ||
c3cd4f6b AK |
445 | if ((pgpath && !m->queue_io) || |
446 | (!pgpath && !m->queue_if_no_path)) | |
447 | must_queue = 0; | |
1da177e4 | 448 | |
b81aa1c7 CS |
449 | if (m->pg_init_required && !m->pg_init_in_progress && pgpath) { |
450 | m->pgpath_to_activate = pgpath; | |
c9e45581 | 451 | m->pg_init_count++; |
1da177e4 | 452 | m->pg_init_required = 0; |
c3cd4f6b AK |
453 | m->pg_init_in_progress = 1; |
454 | init_required = 1; | |
455 | } | |
1da177e4 | 456 | |
c3cd4f6b | 457 | out: |
1da177e4 LT |
458 | spin_unlock_irqrestore(&m->lock, flags); |
459 | ||
bab7cfc7 CS |
460 | if (init_required) |
461 | queue_work(kmpath_handlerd, &m->activate_path); | |
1da177e4 LT |
462 | |
463 | if (!must_queue) | |
464 | dispatch_queued_ios(m); | |
465 | } | |
466 | ||
467 | /* | |
468 | * An event is triggered whenever a path is taken out of use. | |
469 | * Includes path failure and PG bypass. | |
470 | */ | |
c4028958 | 471 | static void trigger_event(struct work_struct *work) |
1da177e4 | 472 | { |
c4028958 DH |
473 | struct multipath *m = |
474 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
475 | |
476 | dm_table_event(m->ti->table); | |
477 | } | |
478 | ||
479 | /*----------------------------------------------------------------- | |
480 | * Constructor/argument parsing: | |
481 | * <#multipath feature args> [<arg>]* | |
482 | * <#hw_handler args> [hw_handler [<arg>]*] | |
483 | * <#priority groups> | |
484 | * <initial priority group> | |
485 | * [<selector> <#selector args> [<arg>]* | |
486 | * <#paths> <#per-path selector args> | |
487 | * [<path> [<arg>]* ]+ ]+ | |
488 | *---------------------------------------------------------------*/ | |
489 | struct param { | |
490 | unsigned min; | |
491 | unsigned max; | |
492 | char *error; | |
493 | }; | |
494 | ||
1da177e4 LT |
495 | static int read_param(struct param *param, char *str, unsigned *v, char **error) |
496 | { | |
497 | if (!str || | |
498 | (sscanf(str, "%u", v) != 1) || | |
499 | (*v < param->min) || | |
500 | (*v > param->max)) { | |
501 | *error = param->error; | |
502 | return -EINVAL; | |
503 | } | |
504 | ||
505 | return 0; | |
506 | } | |
507 | ||
508 | struct arg_set { | |
509 | unsigned argc; | |
510 | char **argv; | |
511 | }; | |
512 | ||
513 | static char *shift(struct arg_set *as) | |
514 | { | |
515 | char *r; | |
516 | ||
517 | if (as->argc) { | |
518 | as->argc--; | |
519 | r = *as->argv; | |
520 | as->argv++; | |
521 | return r; | |
522 | } | |
523 | ||
524 | return NULL; | |
525 | } | |
526 | ||
527 | static void consume(struct arg_set *as, unsigned n) | |
528 | { | |
529 | BUG_ON (as->argc < n); | |
530 | as->argc -= n; | |
531 | as->argv += n; | |
532 | } | |
533 | ||
534 | static int parse_path_selector(struct arg_set *as, struct priority_group *pg, | |
535 | struct dm_target *ti) | |
536 | { | |
537 | int r; | |
538 | struct path_selector_type *pst; | |
539 | unsigned ps_argc; | |
540 | ||
541 | static struct param _params[] = { | |
72d94861 | 542 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
543 | }; |
544 | ||
545 | pst = dm_get_path_selector(shift(as)); | |
546 | if (!pst) { | |
72d94861 | 547 | ti->error = "unknown path selector type"; |
1da177e4 LT |
548 | return -EINVAL; |
549 | } | |
550 | ||
551 | r = read_param(_params, shift(as), &ps_argc, &ti->error); | |
371b2e34 MP |
552 | if (r) { |
553 | dm_put_path_selector(pst); | |
1da177e4 | 554 | return -EINVAL; |
371b2e34 | 555 | } |
1da177e4 LT |
556 | |
557 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
558 | if (r) { | |
559 | dm_put_path_selector(pst); | |
72d94861 | 560 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
561 | return r; |
562 | } | |
563 | ||
564 | pg->ps.type = pst; | |
565 | consume(as, ps_argc); | |
566 | ||
567 | return 0; | |
568 | } | |
569 | ||
570 | static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps, | |
571 | struct dm_target *ti) | |
572 | { | |
573 | int r; | |
574 | struct pgpath *p; | |
ae11b1b3 | 575 | struct multipath *m = ti->private; |
1da177e4 LT |
576 | |
577 | /* we need at least a path arg */ | |
578 | if (as->argc < 1) { | |
72d94861 | 579 | ti->error = "no device given"; |
01460f35 | 580 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
581 | } |
582 | ||
583 | p = alloc_pgpath(); | |
584 | if (!p) | |
01460f35 | 585 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
586 | |
587 | r = dm_get_device(ti, shift(as), ti->begin, ti->len, | |
588 | dm_table_get_mode(ti->table), &p->path.dev); | |
589 | if (r) { | |
72d94861 | 590 | ti->error = "error getting device"; |
1da177e4 LT |
591 | goto bad; |
592 | } | |
593 | ||
ae11b1b3 HR |
594 | if (m->hw_handler_name) { |
595 | r = scsi_dh_attach(bdev_get_queue(p->path.dev->bdev), | |
596 | m->hw_handler_name); | |
597 | if (r < 0) { | |
598 | dm_put_device(ti, p->path.dev); | |
599 | goto bad; | |
600 | } | |
601 | } | |
602 | ||
1da177e4 LT |
603 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
604 | if (r) { | |
605 | dm_put_device(ti, p->path.dev); | |
606 | goto bad; | |
607 | } | |
608 | ||
609 | return p; | |
610 | ||
611 | bad: | |
612 | free_pgpath(p); | |
01460f35 | 613 | return ERR_PTR(r); |
1da177e4 LT |
614 | } |
615 | ||
616 | static struct priority_group *parse_priority_group(struct arg_set *as, | |
28f16c20 | 617 | struct multipath *m) |
1da177e4 LT |
618 | { |
619 | static struct param _params[] = { | |
72d94861 AK |
620 | {1, 1024, "invalid number of paths"}, |
621 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
622 | }; |
623 | ||
624 | int r; | |
625 | unsigned i, nr_selector_args, nr_params; | |
626 | struct priority_group *pg; | |
28f16c20 | 627 | struct dm_target *ti = m->ti; |
1da177e4 LT |
628 | |
629 | if (as->argc < 2) { | |
630 | as->argc = 0; | |
01460f35 BM |
631 | ti->error = "not enough priority group arguments"; |
632 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
633 | } |
634 | ||
635 | pg = alloc_priority_group(); | |
636 | if (!pg) { | |
72d94861 | 637 | ti->error = "couldn't allocate priority group"; |
01460f35 | 638 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
639 | } |
640 | pg->m = m; | |
641 | ||
642 | r = parse_path_selector(as, pg, ti); | |
643 | if (r) | |
644 | goto bad; | |
645 | ||
646 | /* | |
647 | * read the paths | |
648 | */ | |
649 | r = read_param(_params, shift(as), &pg->nr_pgpaths, &ti->error); | |
650 | if (r) | |
651 | goto bad; | |
652 | ||
653 | r = read_param(_params + 1, shift(as), &nr_selector_args, &ti->error); | |
654 | if (r) | |
655 | goto bad; | |
656 | ||
657 | nr_params = 1 + nr_selector_args; | |
658 | for (i = 0; i < pg->nr_pgpaths; i++) { | |
659 | struct pgpath *pgpath; | |
660 | struct arg_set path_args; | |
661 | ||
148acff6 MP |
662 | if (as->argc < nr_params) { |
663 | ti->error = "not enough path parameters"; | |
1da177e4 | 664 | goto bad; |
148acff6 | 665 | } |
1da177e4 LT |
666 | |
667 | path_args.argc = nr_params; | |
668 | path_args.argv = as->argv; | |
669 | ||
670 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
671 | if (IS_ERR(pgpath)) { |
672 | r = PTR_ERR(pgpath); | |
1da177e4 | 673 | goto bad; |
01460f35 | 674 | } |
1da177e4 LT |
675 | |
676 | pgpath->pg = pg; | |
677 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
678 | consume(as, nr_params); | |
679 | } | |
680 | ||
681 | return pg; | |
682 | ||
683 | bad: | |
684 | free_priority_group(pg, ti); | |
01460f35 | 685 | return ERR_PTR(r); |
1da177e4 LT |
686 | } |
687 | ||
28f16c20 | 688 | static int parse_hw_handler(struct arg_set *as, struct multipath *m) |
1da177e4 | 689 | { |
1da177e4 | 690 | unsigned hw_argc; |
28f16c20 | 691 | struct dm_target *ti = m->ti; |
1da177e4 LT |
692 | |
693 | static struct param _params[] = { | |
72d94861 | 694 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
695 | }; |
696 | ||
cfae5c9b | 697 | if (read_param(_params, shift(as), &hw_argc, &ti->error)) |
1da177e4 LT |
698 | return -EINVAL; |
699 | ||
700 | if (!hw_argc) | |
701 | return 0; | |
702 | ||
cfae5c9b CS |
703 | m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL); |
704 | request_module("scsi_dh_%s", m->hw_handler_name); | |
705 | if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { | |
72d94861 | 706 | ti->error = "unknown hardware handler type"; |
fe9233fb CS |
707 | kfree(m->hw_handler_name); |
708 | m->hw_handler_name = NULL; | |
1da177e4 LT |
709 | return -EINVAL; |
710 | } | |
14e98c5c CS |
711 | |
712 | if (hw_argc > 1) | |
713 | DMWARN("Ignoring user-specified arguments for " | |
714 | "hardware handler \"%s\"", m->hw_handler_name); | |
1da177e4 LT |
715 | consume(as, hw_argc - 1); |
716 | ||
717 | return 0; | |
718 | } | |
719 | ||
28f16c20 | 720 | static int parse_features(struct arg_set *as, struct multipath *m) |
1da177e4 LT |
721 | { |
722 | int r; | |
723 | unsigned argc; | |
28f16c20 | 724 | struct dm_target *ti = m->ti; |
c9e45581 | 725 | const char *param_name; |
1da177e4 LT |
726 | |
727 | static struct param _params[] = { | |
c9e45581 DW |
728 | {0, 3, "invalid number of feature args"}, |
729 | {1, 50, "pg_init_retries must be between 1 and 50"}, | |
1da177e4 LT |
730 | }; |
731 | ||
732 | r = read_param(_params, shift(as), &argc, &ti->error); | |
733 | if (r) | |
734 | return -EINVAL; | |
735 | ||
736 | if (!argc) | |
737 | return 0; | |
738 | ||
c9e45581 DW |
739 | do { |
740 | param_name = shift(as); | |
741 | argc--; | |
742 | ||
743 | if (!strnicmp(param_name, MESG_STR("queue_if_no_path"))) { | |
744 | r = queue_if_no_path(m, 1, 0); | |
745 | continue; | |
746 | } | |
747 | ||
748 | if (!strnicmp(param_name, MESG_STR("pg_init_retries")) && | |
749 | (argc >= 1)) { | |
750 | r = read_param(_params + 1, shift(as), | |
751 | &m->pg_init_retries, &ti->error); | |
752 | argc--; | |
753 | continue; | |
754 | } | |
755 | ||
1da177e4 | 756 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
757 | r = -EINVAL; |
758 | } while (argc && !r); | |
759 | ||
760 | return r; | |
1da177e4 LT |
761 | } |
762 | ||
763 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
764 | char **argv) | |
765 | { | |
766 | /* target parameters */ | |
767 | static struct param _params[] = { | |
72d94861 AK |
768 | {1, 1024, "invalid number of priority groups"}, |
769 | {1, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
770 | }; |
771 | ||
772 | int r; | |
773 | struct multipath *m; | |
774 | struct arg_set as; | |
775 | unsigned pg_count = 0; | |
776 | unsigned next_pg_num; | |
777 | ||
778 | as.argc = argc; | |
779 | as.argv = argv; | |
780 | ||
28f16c20 | 781 | m = alloc_multipath(ti); |
1da177e4 | 782 | if (!m) { |
72d94861 | 783 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
784 | return -EINVAL; |
785 | } | |
786 | ||
28f16c20 | 787 | r = parse_features(&as, m); |
1da177e4 LT |
788 | if (r) |
789 | goto bad; | |
790 | ||
28f16c20 | 791 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
792 | if (r) |
793 | goto bad; | |
794 | ||
795 | r = read_param(_params, shift(&as), &m->nr_priority_groups, &ti->error); | |
796 | if (r) | |
797 | goto bad; | |
798 | ||
799 | r = read_param(_params + 1, shift(&as), &next_pg_num, &ti->error); | |
800 | if (r) | |
801 | goto bad; | |
802 | ||
803 | /* parse the priority groups */ | |
804 | while (as.argc) { | |
805 | struct priority_group *pg; | |
806 | ||
28f16c20 | 807 | pg = parse_priority_group(&as, m); |
01460f35 BM |
808 | if (IS_ERR(pg)) { |
809 | r = PTR_ERR(pg); | |
1da177e4 LT |
810 | goto bad; |
811 | } | |
812 | ||
813 | m->nr_valid_paths += pg->nr_pgpaths; | |
814 | list_add_tail(&pg->list, &m->priority_groups); | |
815 | pg_count++; | |
816 | pg->pg_num = pg_count; | |
817 | if (!--next_pg_num) | |
818 | m->next_pg = pg; | |
819 | } | |
820 | ||
821 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 822 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
823 | r = -EINVAL; |
824 | goto bad; | |
825 | } | |
826 | ||
1da177e4 LT |
827 | return 0; |
828 | ||
829 | bad: | |
830 | free_multipath(m); | |
831 | return r; | |
832 | } | |
833 | ||
834 | static void multipath_dtr(struct dm_target *ti) | |
835 | { | |
836 | struct multipath *m = (struct multipath *) ti->private; | |
a044d016 | 837 | |
bab7cfc7 | 838 | flush_workqueue(kmpath_handlerd); |
a044d016 | 839 | flush_workqueue(kmultipathd); |
1da177e4 LT |
840 | free_multipath(m); |
841 | } | |
842 | ||
843 | /* | |
844 | * Map bios, recording original fields for later in case we have to resubmit | |
845 | */ | |
846 | static int multipath_map(struct dm_target *ti, struct bio *bio, | |
847 | union map_info *map_context) | |
848 | { | |
849 | int r; | |
028867ac | 850 | struct dm_mpath_io *mpio; |
1da177e4 LT |
851 | struct multipath *m = (struct multipath *) ti->private; |
852 | ||
853 | mpio = mempool_alloc(m->mpio_pool, GFP_NOIO); | |
854 | dm_bio_record(&mpio->details, bio); | |
855 | ||
856 | map_context->ptr = mpio; | |
6000a368 | 857 | bio->bi_rw |= (1 << BIO_RW_FAILFAST_TRANSPORT); |
1da177e4 | 858 | r = map_io(m, bio, mpio, 0); |
45e15720 | 859 | if (r < 0 || r == DM_MAPIO_REQUEUE) |
1da177e4 LT |
860 | mempool_free(mpio, m->mpio_pool); |
861 | ||
862 | return r; | |
863 | } | |
864 | ||
865 | /* | |
866 | * Take a path out of use. | |
867 | */ | |
868 | static int fail_path(struct pgpath *pgpath) | |
869 | { | |
870 | unsigned long flags; | |
871 | struct multipath *m = pgpath->pg->m; | |
872 | ||
873 | spin_lock_irqsave(&m->lock, flags); | |
874 | ||
6680073d | 875 | if (!pgpath->is_active) |
1da177e4 LT |
876 | goto out; |
877 | ||
72d94861 | 878 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
879 | |
880 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
6680073d | 881 | pgpath->is_active = 0; |
1da177e4 LT |
882 | pgpath->fail_count++; |
883 | ||
884 | m->nr_valid_paths--; | |
885 | ||
886 | if (pgpath == m->current_pgpath) | |
887 | m->current_pgpath = NULL; | |
888 | ||
b15546f9 MA |
889 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
890 | pgpath->path.dev->name, m->nr_valid_paths); | |
891 | ||
fe9cf30e | 892 | schedule_work(&m->trigger_event); |
224cb3e9 | 893 | queue_work(kmultipathd, &pgpath->deactivate_path); |
1da177e4 LT |
894 | |
895 | out: | |
896 | spin_unlock_irqrestore(&m->lock, flags); | |
897 | ||
898 | return 0; | |
899 | } | |
900 | ||
901 | /* | |
902 | * Reinstate a previously-failed path | |
903 | */ | |
904 | static int reinstate_path(struct pgpath *pgpath) | |
905 | { | |
906 | int r = 0; | |
907 | unsigned long flags; | |
908 | struct multipath *m = pgpath->pg->m; | |
909 | ||
910 | spin_lock_irqsave(&m->lock, flags); | |
911 | ||
6680073d | 912 | if (pgpath->is_active) |
1da177e4 LT |
913 | goto out; |
914 | ||
def052d2 | 915 | if (!pgpath->pg->ps.type->reinstate_path) { |
1da177e4 LT |
916 | DMWARN("Reinstate path not supported by path selector %s", |
917 | pgpath->pg->ps.type->name); | |
918 | r = -EINVAL; | |
919 | goto out; | |
920 | } | |
921 | ||
922 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
923 | if (r) | |
924 | goto out; | |
925 | ||
6680073d | 926 | pgpath->is_active = 1; |
1da177e4 LT |
927 | |
928 | m->current_pgpath = NULL; | |
c3cd4f6b | 929 | if (!m->nr_valid_paths++ && m->queue_size) |
c557308e | 930 | queue_work(kmultipathd, &m->process_queued_ios); |
1da177e4 | 931 | |
b15546f9 MA |
932 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
933 | pgpath->path.dev->name, m->nr_valid_paths); | |
934 | ||
fe9cf30e | 935 | schedule_work(&m->trigger_event); |
1da177e4 LT |
936 | |
937 | out: | |
938 | spin_unlock_irqrestore(&m->lock, flags); | |
939 | ||
940 | return r; | |
941 | } | |
942 | ||
943 | /* | |
944 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
945 | */ | |
946 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
947 | action_fn action) | |
948 | { | |
949 | int r = 0; | |
950 | struct pgpath *pgpath; | |
951 | struct priority_group *pg; | |
952 | ||
953 | list_for_each_entry(pg, &m->priority_groups, list) { | |
954 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
955 | if (pgpath->path.dev == dev) | |
956 | r = action(pgpath); | |
957 | } | |
958 | } | |
959 | ||
960 | return r; | |
961 | } | |
962 | ||
963 | /* | |
964 | * Temporarily try to avoid having to use the specified PG | |
965 | */ | |
966 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
967 | int bypassed) | |
968 | { | |
969 | unsigned long flags; | |
970 | ||
971 | spin_lock_irqsave(&m->lock, flags); | |
972 | ||
973 | pg->bypassed = bypassed; | |
974 | m->current_pgpath = NULL; | |
975 | m->current_pg = NULL; | |
976 | ||
977 | spin_unlock_irqrestore(&m->lock, flags); | |
978 | ||
fe9cf30e | 979 | schedule_work(&m->trigger_event); |
1da177e4 LT |
980 | } |
981 | ||
982 | /* | |
983 | * Switch to using the specified PG from the next I/O that gets mapped | |
984 | */ | |
985 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
986 | { | |
987 | struct priority_group *pg; | |
988 | unsigned pgnum; | |
989 | unsigned long flags; | |
990 | ||
991 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
992 | (pgnum > m->nr_priority_groups)) { | |
993 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
994 | return -EINVAL; | |
995 | } | |
996 | ||
997 | spin_lock_irqsave(&m->lock, flags); | |
998 | list_for_each_entry(pg, &m->priority_groups, list) { | |
999 | pg->bypassed = 0; | |
1000 | if (--pgnum) | |
1001 | continue; | |
1002 | ||
1003 | m->current_pgpath = NULL; | |
1004 | m->current_pg = NULL; | |
1005 | m->next_pg = pg; | |
1006 | } | |
1007 | spin_unlock_irqrestore(&m->lock, flags); | |
1008 | ||
fe9cf30e | 1009 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1010 | return 0; |
1011 | } | |
1012 | ||
1013 | /* | |
1014 | * Set/clear bypassed status of a PG. | |
1015 | * PGs are numbered upwards from 1 in the order they were declared. | |
1016 | */ | |
1017 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
1018 | { | |
1019 | struct priority_group *pg; | |
1020 | unsigned pgnum; | |
1021 | ||
1022 | if (!pgstr || (sscanf(pgstr, "%u", &pgnum) != 1) || !pgnum || | |
1023 | (pgnum > m->nr_priority_groups)) { | |
1024 | DMWARN("invalid PG number supplied to bypass_pg"); | |
1025 | return -EINVAL; | |
1026 | } | |
1027 | ||
1028 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1029 | if (!--pgnum) | |
1030 | break; | |
1031 | } | |
1032 | ||
1033 | bypass_pg(m, pg, bypassed); | |
1034 | return 0; | |
1035 | } | |
1036 | ||
c9e45581 DW |
1037 | /* |
1038 | * Should we retry pg_init immediately? | |
1039 | */ | |
1040 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1041 | { | |
1042 | unsigned long flags; | |
1043 | int limit_reached = 0; | |
1044 | ||
1045 | spin_lock_irqsave(&m->lock, flags); | |
1046 | ||
1047 | if (m->pg_init_count <= m->pg_init_retries) | |
1048 | m->pg_init_required = 1; | |
1049 | else | |
1050 | limit_reached = 1; | |
1051 | ||
1052 | spin_unlock_irqrestore(&m->lock, flags); | |
1053 | ||
1054 | return limit_reached; | |
1055 | } | |
1056 | ||
cfae5c9b CS |
1057 | static void pg_init_done(struct dm_path *path, int errors) |
1058 | { | |
1059 | struct pgpath *pgpath = path_to_pgpath(path); | |
1060 | struct priority_group *pg = pgpath->pg; | |
1061 | struct multipath *m = pg->m; | |
1062 | unsigned long flags; | |
1063 | ||
1064 | /* device or driver problems */ | |
1065 | switch (errors) { | |
1066 | case SCSI_DH_OK: | |
1067 | break; | |
1068 | case SCSI_DH_NOSYS: | |
1069 | if (!m->hw_handler_name) { | |
1070 | errors = 0; | |
1071 | break; | |
1072 | } | |
1073 | DMERR("Cannot failover device because scsi_dh_%s was not " | |
1074 | "loaded.", m->hw_handler_name); | |
1075 | /* | |
1076 | * Fail path for now, so we do not ping pong | |
1077 | */ | |
1078 | fail_path(pgpath); | |
1079 | break; | |
1080 | case SCSI_DH_DEV_TEMP_BUSY: | |
1081 | /* | |
1082 | * Probably doing something like FW upgrade on the | |
1083 | * controller so try the other pg. | |
1084 | */ | |
1085 | bypass_pg(m, pg, 1); | |
1086 | break; | |
1087 | /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */ | |
1088 | case SCSI_DH_RETRY: | |
1089 | case SCSI_DH_IMM_RETRY: | |
1090 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1091 | if (pg_init_limit_reached(m, pgpath)) | |
1092 | fail_path(pgpath); | |
1093 | errors = 0; | |
1094 | break; | |
1095 | default: | |
1096 | /* | |
1097 | * We probably do not want to fail the path for a device | |
1098 | * error, but this is what the old dm did. In future | |
1099 | * patches we can do more advanced handling. | |
1100 | */ | |
1101 | fail_path(pgpath); | |
1102 | } | |
1103 | ||
1104 | spin_lock_irqsave(&m->lock, flags); | |
1105 | if (errors) { | |
1106 | DMERR("Could not failover device. Error %d.", errors); | |
1107 | m->current_pgpath = NULL; | |
1108 | m->current_pg = NULL; | |
1109 | } else if (!m->pg_init_required) { | |
1110 | m->queue_io = 0; | |
1111 | pg->bypassed = 0; | |
1112 | } | |
1113 | ||
1114 | m->pg_init_in_progress = 0; | |
1115 | queue_work(kmultipathd, &m->process_queued_ios); | |
1116 | spin_unlock_irqrestore(&m->lock, flags); | |
1117 | } | |
1118 | ||
bab7cfc7 CS |
1119 | static void activate_path(struct work_struct *work) |
1120 | { | |
1121 | int ret; | |
1122 | struct multipath *m = | |
1123 | container_of(work, struct multipath, activate_path); | |
7253a334 CS |
1124 | struct dm_path *path; |
1125 | unsigned long flags; | |
bab7cfc7 | 1126 | |
7253a334 CS |
1127 | spin_lock_irqsave(&m->lock, flags); |
1128 | path = &m->pgpath_to_activate->path; | |
1129 | m->pgpath_to_activate = NULL; | |
1130 | spin_unlock_irqrestore(&m->lock, flags); | |
1131 | if (!path) | |
1132 | return; | |
bab7cfc7 CS |
1133 | ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev)); |
1134 | pg_init_done(path, ret); | |
1135 | } | |
1136 | ||
1da177e4 LT |
1137 | /* |
1138 | * end_io handling | |
1139 | */ | |
1140 | static int do_end_io(struct multipath *m, struct bio *bio, | |
028867ac | 1141 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1142 | { |
640eb3b0 | 1143 | unsigned long flags; |
1da177e4 LT |
1144 | |
1145 | if (!error) | |
1146 | return 0; /* I/O complete */ | |
1147 | ||
4f58802f LMB |
1148 | if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio)) |
1149 | return error; | |
1150 | ||
f6a80ea8 AK |
1151 | if (error == -EOPNOTSUPP) |
1152 | return error; | |
1153 | ||
640eb3b0 | 1154 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 1155 | if (!m->nr_valid_paths) { |
45e15720 KU |
1156 | if (__must_push_back(m)) { |
1157 | spin_unlock_irqrestore(&m->lock, flags); | |
1158 | return DM_ENDIO_REQUEUE; | |
1159 | } else if (!m->queue_if_no_path) { | |
640eb3b0 | 1160 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1161 | return -EIO; |
1162 | } else { | |
640eb3b0 | 1163 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1164 | goto requeue; |
1165 | } | |
1166 | } | |
640eb3b0 | 1167 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1168 | |
cfae5c9b CS |
1169 | if (mpio->pgpath) |
1170 | fail_path(mpio->pgpath); | |
1da177e4 LT |
1171 | |
1172 | requeue: | |
1173 | dm_bio_restore(&mpio->details, bio); | |
1174 | ||
1175 | /* queue for the daemon to resubmit or fail */ | |
640eb3b0 | 1176 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
1177 | bio_list_add(&m->queued_ios, bio); |
1178 | m->queue_size++; | |
1179 | if (!m->queue_io) | |
c557308e | 1180 | queue_work(kmultipathd, &m->process_queued_ios); |
640eb3b0 | 1181 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1182 | |
d2a7ad29 | 1183 | return DM_ENDIO_INCOMPLETE; /* io not complete */ |
1da177e4 LT |
1184 | } |
1185 | ||
1186 | static int multipath_end_io(struct dm_target *ti, struct bio *bio, | |
1187 | int error, union map_info *map_context) | |
1188 | { | |
028867ac AK |
1189 | struct multipath *m = ti->private; |
1190 | struct dm_mpath_io *mpio = map_context->ptr; | |
1da177e4 LT |
1191 | struct pgpath *pgpath = mpio->pgpath; |
1192 | struct path_selector *ps; | |
1193 | int r; | |
1194 | ||
1195 | r = do_end_io(m, bio, error, mpio); | |
1196 | if (pgpath) { | |
1197 | ps = &pgpath->pg->ps; | |
1198 | if (ps->type->end_io) | |
1199 | ps->type->end_io(ps, &pgpath->path); | |
1200 | } | |
d2a7ad29 | 1201 | if (r != DM_ENDIO_INCOMPLETE) |
1da177e4 LT |
1202 | mempool_free(mpio, m->mpio_pool); |
1203 | ||
1204 | return r; | |
1205 | } | |
1206 | ||
1207 | /* | |
1208 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1209 | * the last path fails we must error any remaining I/O. |
1210 | * Note that if the freeze_bdev fails while suspending, the | |
1211 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1212 | */ |
1213 | static void multipath_presuspend(struct dm_target *ti) | |
1214 | { | |
1215 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1216 | |
485ef69e | 1217 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1218 | } |
1219 | ||
436d4108 AK |
1220 | /* |
1221 | * Restore the queue_if_no_path setting. | |
1222 | */ | |
1da177e4 LT |
1223 | static void multipath_resume(struct dm_target *ti) |
1224 | { | |
1225 | struct multipath *m = (struct multipath *) ti->private; | |
1226 | unsigned long flags; | |
1227 | ||
1228 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1229 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1230 | spin_unlock_irqrestore(&m->lock, flags); |
1231 | } | |
1232 | ||
1233 | /* | |
1234 | * Info output has the following format: | |
1235 | * num_multipath_feature_args [multipath_feature_args]* | |
1236 | * num_handler_status_args [handler_status_args]* | |
1237 | * num_groups init_group_number | |
1238 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1239 | * num_paths num_selector_args | |
1240 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1241 | * | |
1242 | * Table output has the following format (identical to the constructor string): | |
1243 | * num_feature_args [features_args]* | |
1244 | * num_handler_args hw_handler [hw_handler_args]* | |
1245 | * num_groups init_group_number | |
1246 | * [priority selector-name num_ps_args [ps_args]* | |
1247 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1248 | */ | |
1249 | static int multipath_status(struct dm_target *ti, status_type_t type, | |
1250 | char *result, unsigned int maxlen) | |
1251 | { | |
1252 | int sz = 0; | |
1253 | unsigned long flags; | |
1254 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1255 | struct priority_group *pg; |
1256 | struct pgpath *p; | |
1257 | unsigned pg_num; | |
1258 | char state; | |
1259 | ||
1260 | spin_lock_irqsave(&m->lock, flags); | |
1261 | ||
1262 | /* Features */ | |
1263 | if (type == STATUSTYPE_INFO) | |
c9e45581 DW |
1264 | DMEMIT("2 %u %u ", m->queue_size, m->pg_init_count); |
1265 | else { | |
1266 | DMEMIT("%u ", m->queue_if_no_path + | |
1267 | (m->pg_init_retries > 0) * 2); | |
1268 | if (m->queue_if_no_path) | |
1269 | DMEMIT("queue_if_no_path "); | |
1270 | if (m->pg_init_retries) | |
1271 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
1272 | } | |
1da177e4 | 1273 | |
cfae5c9b | 1274 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1275 | DMEMIT("0 "); |
1276 | else | |
cfae5c9b | 1277 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1278 | |
1279 | DMEMIT("%u ", m->nr_priority_groups); | |
1280 | ||
1281 | if (m->next_pg) | |
1282 | pg_num = m->next_pg->pg_num; | |
1283 | else if (m->current_pg) | |
1284 | pg_num = m->current_pg->pg_num; | |
1285 | else | |
1286 | pg_num = 1; | |
1287 | ||
1288 | DMEMIT("%u ", pg_num); | |
1289 | ||
1290 | switch (type) { | |
1291 | case STATUSTYPE_INFO: | |
1292 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1293 | if (pg->bypassed) | |
1294 | state = 'D'; /* Disabled */ | |
1295 | else if (pg == m->current_pg) | |
1296 | state = 'A'; /* Currently Active */ | |
1297 | else | |
1298 | state = 'E'; /* Enabled */ | |
1299 | ||
1300 | DMEMIT("%c ", state); | |
1301 | ||
1302 | if (pg->ps.type->status) | |
1303 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1304 | result + sz, | |
1305 | maxlen - sz); | |
1306 | else | |
1307 | DMEMIT("0 "); | |
1308 | ||
1309 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1310 | pg->ps.type->info_args); | |
1311 | ||
1312 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1313 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1314 | p->is_active ? "A" : "F", |
1da177e4 LT |
1315 | p->fail_count); |
1316 | if (pg->ps.type->status) | |
1317 | sz += pg->ps.type->status(&pg->ps, | |
1318 | &p->path, type, result + sz, | |
1319 | maxlen - sz); | |
1320 | } | |
1321 | } | |
1322 | break; | |
1323 | ||
1324 | case STATUSTYPE_TABLE: | |
1325 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1326 | DMEMIT("%s ", pg->ps.type->name); | |
1327 | ||
1328 | if (pg->ps.type->status) | |
1329 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1330 | result + sz, | |
1331 | maxlen - sz); | |
1332 | else | |
1333 | DMEMIT("0 "); | |
1334 | ||
1335 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1336 | pg->ps.type->table_args); | |
1337 | ||
1338 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1339 | DMEMIT("%s ", p->path.dev->name); | |
1340 | if (pg->ps.type->status) | |
1341 | sz += pg->ps.type->status(&pg->ps, | |
1342 | &p->path, type, result + sz, | |
1343 | maxlen - sz); | |
1344 | } | |
1345 | } | |
1346 | break; | |
1347 | } | |
1348 | ||
1349 | spin_unlock_irqrestore(&m->lock, flags); | |
1350 | ||
1351 | return 0; | |
1352 | } | |
1353 | ||
1354 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1355 | { | |
1356 | int r; | |
1357 | struct dm_dev *dev; | |
1358 | struct multipath *m = (struct multipath *) ti->private; | |
1359 | action_fn action; | |
1360 | ||
1361 | if (argc == 1) { | |
1362 | if (!strnicmp(argv[0], MESG_STR("queue_if_no_path"))) | |
485ef69e | 1363 | return queue_if_no_path(m, 1, 0); |
1da177e4 | 1364 | else if (!strnicmp(argv[0], MESG_STR("fail_if_no_path"))) |
485ef69e | 1365 | return queue_if_no_path(m, 0, 0); |
1da177e4 LT |
1366 | } |
1367 | ||
1368 | if (argc != 2) | |
1369 | goto error; | |
1370 | ||
1371 | if (!strnicmp(argv[0], MESG_STR("disable_group"))) | |
1372 | return bypass_pg_num(m, argv[1], 1); | |
1373 | else if (!strnicmp(argv[0], MESG_STR("enable_group"))) | |
1374 | return bypass_pg_num(m, argv[1], 0); | |
1375 | else if (!strnicmp(argv[0], MESG_STR("switch_group"))) | |
1376 | return switch_pg_num(m, argv[1]); | |
1377 | else if (!strnicmp(argv[0], MESG_STR("reinstate_path"))) | |
1378 | action = reinstate_path; | |
1379 | else if (!strnicmp(argv[0], MESG_STR("fail_path"))) | |
1380 | action = fail_path; | |
1381 | else | |
1382 | goto error; | |
1383 | ||
1384 | r = dm_get_device(ti, argv[1], ti->begin, ti->len, | |
1385 | dm_table_get_mode(ti->table), &dev); | |
1386 | if (r) { | |
72d94861 | 1387 | DMWARN("message: error getting device %s", |
1da177e4 LT |
1388 | argv[1]); |
1389 | return -EINVAL; | |
1390 | } | |
1391 | ||
1392 | r = action_dev(m, dev, action); | |
1393 | ||
1394 | dm_put_device(ti, dev); | |
1395 | ||
1396 | return r; | |
1397 | ||
1398 | error: | |
1399 | DMWARN("Unrecognised multipath message received."); | |
1400 | return -EINVAL; | |
1401 | } | |
1402 | ||
647b3d00 | 1403 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
9af4aa30 MB |
1404 | unsigned long arg) |
1405 | { | |
1406 | struct multipath *m = (struct multipath *) ti->private; | |
1407 | struct block_device *bdev = NULL; | |
633a08b8 | 1408 | fmode_t mode = 0; |
9af4aa30 MB |
1409 | unsigned long flags; |
1410 | int r = 0; | |
1411 | ||
1412 | spin_lock_irqsave(&m->lock, flags); | |
1413 | ||
1414 | if (!m->current_pgpath) | |
1415 | __choose_pgpath(m); | |
1416 | ||
e90dae1f | 1417 | if (m->current_pgpath) { |
9af4aa30 | 1418 | bdev = m->current_pgpath->path.dev->bdev; |
633a08b8 | 1419 | mode = m->current_pgpath->path.dev->mode; |
e90dae1f | 1420 | } |
9af4aa30 MB |
1421 | |
1422 | if (m->queue_io) | |
1423 | r = -EAGAIN; | |
1424 | else if (!bdev) | |
1425 | r = -EIO; | |
1426 | ||
1427 | spin_unlock_irqrestore(&m->lock, flags); | |
1428 | ||
633a08b8 | 1429 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
9af4aa30 MB |
1430 | } |
1431 | ||
1da177e4 LT |
1432 | /*----------------------------------------------------------------- |
1433 | * Module setup | |
1434 | *---------------------------------------------------------------*/ | |
1435 | static struct target_type multipath_target = { | |
1436 | .name = "multipath", | |
9af4aa30 | 1437 | .version = {1, 0, 5}, |
1da177e4 LT |
1438 | .module = THIS_MODULE, |
1439 | .ctr = multipath_ctr, | |
1440 | .dtr = multipath_dtr, | |
1441 | .map = multipath_map, | |
1442 | .end_io = multipath_end_io, | |
1443 | .presuspend = multipath_presuspend, | |
1444 | .resume = multipath_resume, | |
1445 | .status = multipath_status, | |
1446 | .message = multipath_message, | |
9af4aa30 | 1447 | .ioctl = multipath_ioctl, |
1da177e4 LT |
1448 | }; |
1449 | ||
1450 | static int __init dm_multipath_init(void) | |
1451 | { | |
1452 | int r; | |
1453 | ||
1454 | /* allocate a slab for the dm_ios */ | |
028867ac | 1455 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1456 | if (!_mpio_cache) |
1457 | return -ENOMEM; | |
1458 | ||
1459 | r = dm_register_target(&multipath_target); | |
1460 | if (r < 0) { | |
0cd33124 | 1461 | DMERR("register failed %d", r); |
1da177e4 LT |
1462 | kmem_cache_destroy(_mpio_cache); |
1463 | return -EINVAL; | |
1464 | } | |
1465 | ||
c557308e AK |
1466 | kmultipathd = create_workqueue("kmpathd"); |
1467 | if (!kmultipathd) { | |
0cd33124 | 1468 | DMERR("failed to create workqueue kmpathd"); |
c557308e AK |
1469 | dm_unregister_target(&multipath_target); |
1470 | kmem_cache_destroy(_mpio_cache); | |
1471 | return -ENOMEM; | |
1472 | } | |
1473 | ||
bab7cfc7 CS |
1474 | /* |
1475 | * A separate workqueue is used to handle the device handlers | |
1476 | * to avoid overloading existing workqueue. Overloading the | |
1477 | * old workqueue would also create a bottleneck in the | |
1478 | * path of the storage hardware device activation. | |
1479 | */ | |
1480 | kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd"); | |
1481 | if (!kmpath_handlerd) { | |
1482 | DMERR("failed to create workqueue kmpath_handlerd"); | |
1483 | destroy_workqueue(kmultipathd); | |
1484 | dm_unregister_target(&multipath_target); | |
1485 | kmem_cache_destroy(_mpio_cache); | |
1486 | return -ENOMEM; | |
1487 | } | |
1488 | ||
72d94861 | 1489 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1490 | multipath_target.version[0], multipath_target.version[1], |
1491 | multipath_target.version[2]); | |
1492 | ||
1493 | return r; | |
1494 | } | |
1495 | ||
1496 | static void __exit dm_multipath_exit(void) | |
1497 | { | |
bab7cfc7 | 1498 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1499 | destroy_workqueue(kmultipathd); |
1500 | ||
10d3bd09 | 1501 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
1502 | kmem_cache_destroy(_mpio_cache); |
1503 | } | |
1504 | ||
1da177e4 LT |
1505 | module_init(dm_multipath_init); |
1506 | module_exit(dm_multipath_exit); | |
1507 | ||
1508 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1509 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1510 | MODULE_LICENSE("GPL"); |