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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software Limited. | |
3 | * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
586e80e6 MP |
8 | #include <linux/device-mapper.h> |
9 | ||
f4790826 | 10 | #include "dm.h" |
1da177e4 | 11 | #include "dm-path-selector.h" |
b15546f9 | 12 | #include "dm-uevent.h" |
1da177e4 | 13 | |
e5863d9a | 14 | #include <linux/blkdev.h> |
1da177e4 LT |
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> | |
35991652 | 23 | #include <linux/delay.h> |
cfae5c9b | 24 | #include <scsi/scsi_dh.h> |
60063497 | 25 | #include <linux/atomic.h> |
1da177e4 | 26 | |
72d94861 | 27 | #define DM_MSG_PREFIX "multipath" |
4e2d19e4 CS |
28 | #define DM_PG_INIT_DELAY_MSECS 2000 |
29 | #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) | |
1da177e4 LT |
30 | |
31 | /* Path properties */ | |
32 | struct pgpath { | |
33 | struct list_head list; | |
34 | ||
35 | struct priority_group *pg; /* Owning PG */ | |
6680073d | 36 | unsigned is_active; /* Path status */ |
1da177e4 LT |
37 | unsigned fail_count; /* Cumulative failure count */ |
38 | ||
c922d5f7 | 39 | struct dm_path path; |
4e2d19e4 | 40 | struct delayed_work activate_path; |
1da177e4 LT |
41 | }; |
42 | ||
43 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
44 | ||
45 | /* | |
46 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
47 | * Each has a path selector which controls which path gets used. | |
48 | */ | |
49 | struct priority_group { | |
50 | struct list_head list; | |
51 | ||
52 | struct multipath *m; /* Owning multipath instance */ | |
53 | struct path_selector ps; | |
54 | ||
55 | unsigned pg_num; /* Reference number */ | |
56 | unsigned bypassed; /* Temporarily bypass this PG? */ | |
57 | ||
58 | unsigned nr_pgpaths; /* Number of paths in PG */ | |
59 | struct list_head pgpaths; | |
60 | }; | |
61 | ||
62 | /* Multipath context */ | |
63 | struct multipath { | |
64 | struct list_head list; | |
65 | struct dm_target *ti; | |
66 | ||
cfae5c9b | 67 | const char *hw_handler_name; |
2bfd2e13 | 68 | char *hw_handler_params; |
4e2d19e4 | 69 | |
1fbdd2b3 MS |
70 | spinlock_t lock; |
71 | ||
1da177e4 LT |
72 | unsigned nr_priority_groups; |
73 | struct list_head priority_groups; | |
4e2d19e4 CS |
74 | |
75 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ | |
76 | ||
1da177e4 | 77 | unsigned pg_init_required; /* pg_init needs calling? */ |
c3cd4f6b | 78 | unsigned pg_init_in_progress; /* Only one pg_init allowed at once */ |
4e2d19e4 | 79 | unsigned pg_init_delay_retry; /* Delay pg_init retry? */ |
1da177e4 LT |
80 | |
81 | unsigned nr_valid_paths; /* Total number of usable paths */ | |
82 | struct pgpath *current_pgpath; | |
83 | struct priority_group *current_pg; | |
84 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
85 | unsigned repeat_count; /* I/Os left before calling PS again */ | |
86 | ||
1fbdd2b3 MS |
87 | unsigned queue_io:1; /* Must we queue all I/O? */ |
88 | unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */ | |
89 | unsigned saved_queue_if_no_path:1; /* Saved state during suspension */ | |
a58a935d | 90 | unsigned retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */ |
954a73d5 | 91 | unsigned pg_init_disabled:1; /* pg_init is not currently allowed */ |
1fbdd2b3 | 92 | |
c9e45581 DW |
93 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
94 | unsigned pg_init_count; /* Number of times pg_init called */ | |
4e2d19e4 | 95 | unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ |
1da177e4 | 96 | |
1da177e4 LT |
97 | struct work_struct trigger_event; |
98 | ||
99 | /* | |
028867ac | 100 | * We must use a mempool of dm_mpath_io structs so that we |
1da177e4 LT |
101 | * can resubmit bios on error. |
102 | */ | |
103 | mempool_t *mpio_pool; | |
6380f26f MA |
104 | |
105 | struct mutex work_mutex; | |
1da177e4 LT |
106 | }; |
107 | ||
108 | /* | |
109 | * Context information attached to each bio we process. | |
110 | */ | |
028867ac | 111 | struct dm_mpath_io { |
1da177e4 | 112 | struct pgpath *pgpath; |
02ab823f | 113 | size_t nr_bytes; |
1da177e4 LT |
114 | }; |
115 | ||
116 | typedef int (*action_fn) (struct pgpath *pgpath); | |
117 | ||
e18b890b | 118 | static struct kmem_cache *_mpio_cache; |
1da177e4 | 119 | |
bab7cfc7 | 120 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 | 121 | static void trigger_event(struct work_struct *work); |
bab7cfc7 | 122 | static void activate_path(struct work_struct *work); |
e8099177 | 123 | static int __pgpath_busy(struct pgpath *pgpath); |
1da177e4 LT |
124 | |
125 | ||
126 | /*----------------------------------------------- | |
127 | * Allocation routines | |
128 | *-----------------------------------------------*/ | |
129 | ||
130 | static struct pgpath *alloc_pgpath(void) | |
131 | { | |
e69fae56 | 132 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 133 | |
224cb3e9 | 134 | if (pgpath) { |
6680073d | 135 | pgpath->is_active = 1; |
4e2d19e4 | 136 | INIT_DELAYED_WORK(&pgpath->activate_path, activate_path); |
224cb3e9 | 137 | } |
1da177e4 LT |
138 | |
139 | return pgpath; | |
140 | } | |
141 | ||
028867ac | 142 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
143 | { |
144 | kfree(pgpath); | |
145 | } | |
146 | ||
147 | static struct priority_group *alloc_priority_group(void) | |
148 | { | |
149 | struct priority_group *pg; | |
150 | ||
e69fae56 | 151 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 152 | |
e69fae56 MM |
153 | if (pg) |
154 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
155 | |
156 | return pg; | |
157 | } | |
158 | ||
159 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
160 | { | |
161 | struct pgpath *pgpath, *tmp; | |
162 | ||
163 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
164 | list_del(&pgpath->list); | |
165 | dm_put_device(ti, pgpath->path.dev); | |
166 | free_pgpath(pgpath); | |
167 | } | |
168 | } | |
169 | ||
170 | static void free_priority_group(struct priority_group *pg, | |
171 | struct dm_target *ti) | |
172 | { | |
173 | struct path_selector *ps = &pg->ps; | |
174 | ||
175 | if (ps->type) { | |
176 | ps->type->destroy(ps); | |
177 | dm_put_path_selector(ps->type); | |
178 | } | |
179 | ||
180 | free_pgpaths(&pg->pgpaths, ti); | |
181 | kfree(pg); | |
182 | } | |
183 | ||
8637a6bf | 184 | static struct multipath *alloc_multipath(struct dm_target *ti, bool use_blk_mq) |
1da177e4 LT |
185 | { |
186 | struct multipath *m; | |
187 | ||
e69fae56 | 188 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 189 | if (m) { |
1da177e4 LT |
190 | INIT_LIST_HEAD(&m->priority_groups); |
191 | spin_lock_init(&m->lock); | |
192 | m->queue_io = 1; | |
4e2d19e4 | 193 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; |
c4028958 | 194 | INIT_WORK(&m->trigger_event, trigger_event); |
2bded7bd | 195 | init_waitqueue_head(&m->pg_init_wait); |
6380f26f | 196 | mutex_init(&m->work_mutex); |
8637a6bf MS |
197 | |
198 | m->mpio_pool = NULL; | |
199 | if (!use_blk_mq) { | |
200 | unsigned min_ios = dm_get_reserved_rq_based_ios(); | |
201 | ||
202 | m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache); | |
203 | if (!m->mpio_pool) { | |
204 | kfree(m); | |
205 | return NULL; | |
206 | } | |
1da177e4 | 207 | } |
8637a6bf | 208 | |
28f16c20 MM |
209 | m->ti = ti; |
210 | ti->private = m; | |
1da177e4 LT |
211 | } |
212 | ||
213 | return m; | |
214 | } | |
215 | ||
216 | static void free_multipath(struct multipath *m) | |
217 | { | |
218 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
219 | |
220 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
221 | list_del(&pg->list); | |
222 | free_priority_group(pg, m->ti); | |
223 | } | |
224 | ||
cfae5c9b | 225 | kfree(m->hw_handler_name); |
2bfd2e13 | 226 | kfree(m->hw_handler_params); |
1da177e4 LT |
227 | mempool_destroy(m->mpio_pool); |
228 | kfree(m); | |
229 | } | |
230 | ||
466891f9 JN |
231 | static int set_mapinfo(struct multipath *m, union map_info *info) |
232 | { | |
233 | struct dm_mpath_io *mpio; | |
234 | ||
8637a6bf MS |
235 | if (!m->mpio_pool) { |
236 | /* Use blk-mq pdu memory requested via per_io_data_size */ | |
237 | mpio = info->ptr; | |
238 | memset(mpio, 0, sizeof(*mpio)); | |
239 | return mpio; | |
240 | } | |
241 | ||
466891f9 JN |
242 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); |
243 | if (!mpio) | |
244 | return -ENOMEM; | |
245 | ||
246 | memset(mpio, 0, sizeof(*mpio)); | |
247 | info->ptr = mpio; | |
248 | ||
249 | return 0; | |
250 | } | |
251 | ||
252 | static void clear_mapinfo(struct multipath *m, union map_info *info) | |
253 | { | |
8637a6bf MS |
254 | /* Only needed for non blk-mq */ |
255 | if (m->mpio_pool) { | |
256 | struct dm_mpath_io *mpio = info->ptr; | |
466891f9 | 257 | |
8637a6bf MS |
258 | info->ptr = NULL; |
259 | mempool_free(mpio, m->mpio_pool); | |
260 | } | |
466891f9 | 261 | } |
1da177e4 LT |
262 | |
263 | /*----------------------------------------------- | |
264 | * Path selection | |
265 | *-----------------------------------------------*/ | |
266 | ||
3e9f1be1 | 267 | static int __pg_init_all_paths(struct multipath *m) |
fb612642 KU |
268 | { |
269 | struct pgpath *pgpath; | |
4e2d19e4 | 270 | unsigned long pg_init_delay = 0; |
fb612642 | 271 | |
17f4ff45 | 272 | if (m->pg_init_in_progress || m->pg_init_disabled) |
3e9f1be1 | 273 | return 0; |
17f4ff45 | 274 | |
fb612642 KU |
275 | m->pg_init_count++; |
276 | m->pg_init_required = 0; | |
3e9f1be1 HR |
277 | |
278 | /* Check here to reset pg_init_required */ | |
279 | if (!m->current_pg) | |
280 | return 0; | |
281 | ||
4e2d19e4 CS |
282 | if (m->pg_init_delay_retry) |
283 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? | |
284 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); | |
fb612642 KU |
285 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
286 | /* Skip failed paths */ | |
287 | if (!pgpath->is_active) | |
288 | continue; | |
4e2d19e4 CS |
289 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
290 | pg_init_delay)) | |
fb612642 KU |
291 | m->pg_init_in_progress++; |
292 | } | |
3e9f1be1 | 293 | return m->pg_init_in_progress; |
fb612642 KU |
294 | } |
295 | ||
1da177e4 LT |
296 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) |
297 | { | |
1da177e4 LT |
298 | m->current_pg = pgpath->pg; |
299 | ||
300 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 301 | if (m->hw_handler_name) { |
1da177e4 LT |
302 | m->pg_init_required = 1; |
303 | m->queue_io = 1; | |
304 | } else { | |
305 | m->pg_init_required = 0; | |
306 | m->queue_io = 0; | |
307 | } | |
c9e45581 DW |
308 | |
309 | m->pg_init_count = 0; | |
1da177e4 LT |
310 | } |
311 | ||
02ab823f KU |
312 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
313 | size_t nr_bytes) | |
1da177e4 | 314 | { |
c922d5f7 | 315 | struct dm_path *path; |
1da177e4 | 316 | |
02ab823f | 317 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes); |
1da177e4 LT |
318 | if (!path) |
319 | return -ENXIO; | |
320 | ||
321 | m->current_pgpath = path_to_pgpath(path); | |
322 | ||
323 | if (m->current_pg != pg) | |
324 | __switch_pg(m, m->current_pgpath); | |
325 | ||
326 | return 0; | |
327 | } | |
328 | ||
02ab823f | 329 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 LT |
330 | { |
331 | struct priority_group *pg; | |
332 | unsigned bypassed = 1; | |
333 | ||
1f271972 BM |
334 | if (!m->nr_valid_paths) { |
335 | m->queue_io = 0; | |
1da177e4 | 336 | goto failed; |
1f271972 | 337 | } |
1da177e4 LT |
338 | |
339 | /* Were we instructed to switch PG? */ | |
340 | if (m->next_pg) { | |
341 | pg = m->next_pg; | |
342 | m->next_pg = NULL; | |
02ab823f | 343 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
344 | return; |
345 | } | |
346 | ||
347 | /* Don't change PG until it has no remaining paths */ | |
02ab823f | 348 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes)) |
1da177e4 LT |
349 | return; |
350 | ||
351 | /* | |
352 | * Loop through priority groups until we find a valid path. | |
353 | * First time we skip PGs marked 'bypassed'. | |
f220fd4e MC |
354 | * Second time we only try the ones we skipped, but set |
355 | * pg_init_delay_retry so we do not hammer controllers. | |
1da177e4 LT |
356 | */ |
357 | do { | |
358 | list_for_each_entry(pg, &m->priority_groups, list) { | |
359 | if (pg->bypassed == bypassed) | |
360 | continue; | |
f220fd4e MC |
361 | if (!__choose_path_in_pg(m, pg, nr_bytes)) { |
362 | if (!bypassed) | |
363 | m->pg_init_delay_retry = 1; | |
1da177e4 | 364 | return; |
f220fd4e | 365 | } |
1da177e4 LT |
366 | } |
367 | } while (bypassed--); | |
368 | ||
369 | failed: | |
370 | m->current_pgpath = NULL; | |
371 | m->current_pg = NULL; | |
372 | } | |
373 | ||
45e15720 KU |
374 | /* |
375 | * Check whether bios must be queued in the device-mapper core rather | |
376 | * than here in the target. | |
377 | * | |
378 | * m->lock must be held on entry. | |
379 | * | |
380 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
381 | * same value then we are not between multipath_presuspend() | |
382 | * and multipath_resume() calls and we have no need to check | |
383 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
384 | */ | |
385 | static int __must_push_back(struct multipath *m) | |
386 | { | |
e8099177 HR |
387 | return (m->queue_if_no_path || |
388 | (m->queue_if_no_path != m->saved_queue_if_no_path && | |
389 | dm_noflush_suspending(m->ti))); | |
45e15720 KU |
390 | } |
391 | ||
36fcffcc HR |
392 | /* |
393 | * Map cloned requests | |
394 | */ | |
e5863d9a MS |
395 | static int __multipath_map(struct dm_target *ti, struct request *clone, |
396 | union map_info *map_context, | |
397 | struct request *rq, struct request **__clone) | |
1da177e4 | 398 | { |
36fcffcc | 399 | struct multipath *m = (struct multipath *) ti->private; |
e3bde04f | 400 | int r = DM_MAPIO_REQUEUE; |
e5863d9a | 401 | size_t nr_bytes = clone ? blk_rq_bytes(clone) : blk_rq_bytes(rq); |
1da177e4 | 402 | struct pgpath *pgpath; |
f40c67f0 | 403 | struct block_device *bdev; |
e3bde04f | 404 | struct dm_mpath_io *mpio; |
1da177e4 | 405 | |
2eb6e1e3 | 406 | spin_lock_irq(&m->lock); |
1da177e4 LT |
407 | |
408 | /* Do we need to select a new pgpath? */ | |
409 | if (!m->current_pgpath || | |
410 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
02ab823f | 411 | __choose_pgpath(m, nr_bytes); |
1da177e4 LT |
412 | |
413 | pgpath = m->current_pgpath; | |
414 | ||
9bf59a61 MS |
415 | if (!pgpath) { |
416 | if (!__must_push_back(m)) | |
417 | r = -EIO; /* Failed */ | |
418 | goto out_unlock; | |
6afbc01d | 419 | } else if (m->queue_io || m->pg_init_required) { |
e3bde04f | 420 | __pg_init_all_paths(m); |
9bf59a61 MS |
421 | goto out_unlock; |
422 | } | |
6afbc01d | 423 | |
9bf59a61 MS |
424 | if (set_mapinfo(m, map_context) < 0) |
425 | /* ENOMEM, requeue */ | |
426 | goto out_unlock; | |
427 | ||
2eb6e1e3 KB |
428 | mpio = map_context->ptr; |
429 | mpio->pgpath = pgpath; | |
430 | mpio->nr_bytes = nr_bytes; | |
431 | ||
9bf59a61 | 432 | bdev = pgpath->path.dev->bdev; |
2eb6e1e3 | 433 | |
2eb6e1e3 KB |
434 | spin_unlock_irq(&m->lock); |
435 | ||
e5863d9a | 436 | if (clone) { |
c5248f79 MS |
437 | /* |
438 | * Old request-based interface: allocated clone is passed in. | |
439 | * Used by: .request_fn stacked on .request_fn path(s). | |
440 | */ | |
e5863d9a MS |
441 | clone->q = bdev_get_queue(bdev); |
442 | clone->rq_disk = bdev->bd_disk; | |
443 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; | |
444 | } else { | |
eca7ee6d MS |
445 | /* |
446 | * blk-mq request-based interface; used by both: | |
447 | * .request_fn stacked on blk-mq path(s) and | |
448 | * blk-mq stacked on blk-mq path(s). | |
449 | */ | |
e5863d9a | 450 | *__clone = blk_get_request(bdev_get_queue(bdev), |
02233342 | 451 | rq_data_dir(rq), GFP_ATOMIC); |
4c6dd53d | 452 | if (IS_ERR(*__clone)) { |
e5863d9a | 453 | /* ENOMEM, requeue */ |
4c6dd53d | 454 | clear_mapinfo(m, map_context); |
e5863d9a | 455 | return r; |
4c6dd53d | 456 | } |
e5863d9a MS |
457 | (*__clone)->bio = (*__clone)->biotail = NULL; |
458 | (*__clone)->rq_disk = bdev->bd_disk; | |
459 | (*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT; | |
460 | } | |
461 | ||
9bf59a61 MS |
462 | if (pgpath->pg->ps.type->start_io) |
463 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
464 | &pgpath->path, | |
465 | nr_bytes); | |
2eb6e1e3 | 466 | return DM_MAPIO_REMAPPED; |
1da177e4 | 467 | |
e3bde04f | 468 | out_unlock: |
2eb6e1e3 | 469 | spin_unlock_irq(&m->lock); |
1da177e4 LT |
470 | |
471 | return r; | |
472 | } | |
473 | ||
e5863d9a MS |
474 | static int multipath_map(struct dm_target *ti, struct request *clone, |
475 | union map_info *map_context) | |
476 | { | |
477 | return __multipath_map(ti, clone, map_context, NULL, NULL); | |
478 | } | |
479 | ||
480 | static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, | |
481 | union map_info *map_context, | |
482 | struct request **clone) | |
483 | { | |
484 | return __multipath_map(ti, NULL, map_context, rq, clone); | |
485 | } | |
486 | ||
487 | static void multipath_release_clone(struct request *clone) | |
488 | { | |
489 | blk_put_request(clone); | |
490 | } | |
491 | ||
1da177e4 LT |
492 | /* |
493 | * If we run out of usable paths, should we queue I/O or error it? | |
494 | */ | |
485ef69e AK |
495 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
496 | unsigned save_old_value) | |
1da177e4 LT |
497 | { |
498 | unsigned long flags; | |
499 | ||
500 | spin_lock_irqsave(&m->lock, flags); | |
501 | ||
485ef69e AK |
502 | if (save_old_value) |
503 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
504 | else | |
505 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 506 | m->queue_if_no_path = queue_if_no_path; |
1da177e4 LT |
507 | spin_unlock_irqrestore(&m->lock, flags); |
508 | ||
63d832c3 HR |
509 | if (!queue_if_no_path) |
510 | dm_table_run_md_queue_async(m->ti->table); | |
511 | ||
1da177e4 LT |
512 | return 0; |
513 | } | |
514 | ||
1da177e4 LT |
515 | /* |
516 | * An event is triggered whenever a path is taken out of use. | |
517 | * Includes path failure and PG bypass. | |
518 | */ | |
c4028958 | 519 | static void trigger_event(struct work_struct *work) |
1da177e4 | 520 | { |
c4028958 DH |
521 | struct multipath *m = |
522 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
523 | |
524 | dm_table_event(m->ti->table); | |
525 | } | |
526 | ||
527 | /*----------------------------------------------------------------- | |
528 | * Constructor/argument parsing: | |
529 | * <#multipath feature args> [<arg>]* | |
530 | * <#hw_handler args> [hw_handler [<arg>]*] | |
531 | * <#priority groups> | |
532 | * <initial priority group> | |
533 | * [<selector> <#selector args> [<arg>]* | |
534 | * <#paths> <#per-path selector args> | |
535 | * [<path> [<arg>]* ]+ ]+ | |
536 | *---------------------------------------------------------------*/ | |
498f0103 | 537 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
1da177e4 LT |
538 | struct dm_target *ti) |
539 | { | |
540 | int r; | |
541 | struct path_selector_type *pst; | |
542 | unsigned ps_argc; | |
543 | ||
498f0103 | 544 | static struct dm_arg _args[] = { |
72d94861 | 545 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
546 | }; |
547 | ||
498f0103 | 548 | pst = dm_get_path_selector(dm_shift_arg(as)); |
1da177e4 | 549 | if (!pst) { |
72d94861 | 550 | ti->error = "unknown path selector type"; |
1da177e4 LT |
551 | return -EINVAL; |
552 | } | |
553 | ||
498f0103 | 554 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
371b2e34 MP |
555 | if (r) { |
556 | dm_put_path_selector(pst); | |
1da177e4 | 557 | return -EINVAL; |
371b2e34 | 558 | } |
1da177e4 LT |
559 | |
560 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
561 | if (r) { | |
562 | dm_put_path_selector(pst); | |
72d94861 | 563 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
564 | return r; |
565 | } | |
566 | ||
567 | pg->ps.type = pst; | |
498f0103 | 568 | dm_consume_args(as, ps_argc); |
1da177e4 LT |
569 | |
570 | return 0; | |
571 | } | |
572 | ||
498f0103 | 573 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, |
1da177e4 LT |
574 | struct dm_target *ti) |
575 | { | |
576 | int r; | |
577 | struct pgpath *p; | |
ae11b1b3 | 578 | struct multipath *m = ti->private; |
a58a935d MS |
579 | struct request_queue *q = NULL; |
580 | const char *attached_handler_name; | |
1da177e4 LT |
581 | |
582 | /* we need at least a path arg */ | |
583 | if (as->argc < 1) { | |
72d94861 | 584 | ti->error = "no device given"; |
01460f35 | 585 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
586 | } |
587 | ||
588 | p = alloc_pgpath(); | |
589 | if (!p) | |
01460f35 | 590 | return ERR_PTR(-ENOMEM); |
1da177e4 | 591 | |
498f0103 | 592 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), |
8215d6ec | 593 | &p->path.dev); |
1da177e4 | 594 | if (r) { |
72d94861 | 595 | ti->error = "error getting device"; |
1da177e4 LT |
596 | goto bad; |
597 | } | |
598 | ||
a58a935d MS |
599 | if (m->retain_attached_hw_handler || m->hw_handler_name) |
600 | q = bdev_get_queue(p->path.dev->bdev); | |
601 | ||
602 | if (m->retain_attached_hw_handler) { | |
1bab0de0 | 603 | retain: |
a58a935d MS |
604 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); |
605 | if (attached_handler_name) { | |
606 | /* | |
607 | * Reset hw_handler_name to match the attached handler | |
608 | * and clear any hw_handler_params associated with the | |
609 | * ignored handler. | |
610 | * | |
611 | * NB. This modifies the table line to show the actual | |
612 | * handler instead of the original table passed in. | |
613 | */ | |
614 | kfree(m->hw_handler_name); | |
615 | m->hw_handler_name = attached_handler_name; | |
616 | ||
617 | kfree(m->hw_handler_params); | |
618 | m->hw_handler_params = NULL; | |
619 | } | |
620 | } | |
a0cf7ea9 | 621 | |
a58a935d | 622 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
623 | r = scsi_dh_attach(q, m->hw_handler_name); |
624 | if (r == -EBUSY) { | |
1bab0de0 | 625 | char b[BDEVNAME_SIZE]; |
a0cf7ea9 | 626 | |
1bab0de0 CH |
627 | printk(KERN_INFO "dm-mpath: retaining handler on device %s\n", |
628 | bdevname(p->path.dev->bdev, b)); | |
629 | goto retain; | |
630 | } | |
ae11b1b3 | 631 | if (r < 0) { |
a0cf7ea9 | 632 | ti->error = "error attaching hardware handler"; |
ae11b1b3 HR |
633 | dm_put_device(ti, p->path.dev); |
634 | goto bad; | |
635 | } | |
2bfd2e13 CS |
636 | |
637 | if (m->hw_handler_params) { | |
638 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
639 | if (r < 0) { | |
640 | ti->error = "unable to set hardware " | |
641 | "handler parameters"; | |
2bfd2e13 CS |
642 | dm_put_device(ti, p->path.dev); |
643 | goto bad; | |
644 | } | |
645 | } | |
ae11b1b3 HR |
646 | } |
647 | ||
1da177e4 LT |
648 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
649 | if (r) { | |
650 | dm_put_device(ti, p->path.dev); | |
651 | goto bad; | |
652 | } | |
653 | ||
654 | return p; | |
655 | ||
656 | bad: | |
657 | free_pgpath(p); | |
01460f35 | 658 | return ERR_PTR(r); |
1da177e4 LT |
659 | } |
660 | ||
498f0103 | 661 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
28f16c20 | 662 | struct multipath *m) |
1da177e4 | 663 | { |
498f0103 | 664 | static struct dm_arg _args[] = { |
72d94861 AK |
665 | {1, 1024, "invalid number of paths"}, |
666 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
667 | }; |
668 | ||
669 | int r; | |
498f0103 | 670 | unsigned i, nr_selector_args, nr_args; |
1da177e4 | 671 | struct priority_group *pg; |
28f16c20 | 672 | struct dm_target *ti = m->ti; |
1da177e4 LT |
673 | |
674 | if (as->argc < 2) { | |
675 | as->argc = 0; | |
01460f35 BM |
676 | ti->error = "not enough priority group arguments"; |
677 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
678 | } |
679 | ||
680 | pg = alloc_priority_group(); | |
681 | if (!pg) { | |
72d94861 | 682 | ti->error = "couldn't allocate priority group"; |
01460f35 | 683 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
684 | } |
685 | pg->m = m; | |
686 | ||
687 | r = parse_path_selector(as, pg, ti); | |
688 | if (r) | |
689 | goto bad; | |
690 | ||
691 | /* | |
692 | * read the paths | |
693 | */ | |
498f0103 | 694 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
1da177e4 LT |
695 | if (r) |
696 | goto bad; | |
697 | ||
498f0103 | 698 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
1da177e4 LT |
699 | if (r) |
700 | goto bad; | |
701 | ||
498f0103 | 702 | nr_args = 1 + nr_selector_args; |
1da177e4 LT |
703 | for (i = 0; i < pg->nr_pgpaths; i++) { |
704 | struct pgpath *pgpath; | |
498f0103 | 705 | struct dm_arg_set path_args; |
1da177e4 | 706 | |
498f0103 | 707 | if (as->argc < nr_args) { |
148acff6 | 708 | ti->error = "not enough path parameters"; |
6bbf79a1 | 709 | r = -EINVAL; |
1da177e4 | 710 | goto bad; |
148acff6 | 711 | } |
1da177e4 | 712 | |
498f0103 | 713 | path_args.argc = nr_args; |
1da177e4 LT |
714 | path_args.argv = as->argv; |
715 | ||
716 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
717 | if (IS_ERR(pgpath)) { |
718 | r = PTR_ERR(pgpath); | |
1da177e4 | 719 | goto bad; |
01460f35 | 720 | } |
1da177e4 LT |
721 | |
722 | pgpath->pg = pg; | |
723 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
498f0103 | 724 | dm_consume_args(as, nr_args); |
1da177e4 LT |
725 | } |
726 | ||
727 | return pg; | |
728 | ||
729 | bad: | |
730 | free_priority_group(pg, ti); | |
01460f35 | 731 | return ERR_PTR(r); |
1da177e4 LT |
732 | } |
733 | ||
498f0103 | 734 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
1da177e4 | 735 | { |
1da177e4 | 736 | unsigned hw_argc; |
2bfd2e13 | 737 | int ret; |
28f16c20 | 738 | struct dm_target *ti = m->ti; |
1da177e4 | 739 | |
498f0103 | 740 | static struct dm_arg _args[] = { |
72d94861 | 741 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
742 | }; |
743 | ||
498f0103 | 744 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
1da177e4 LT |
745 | return -EINVAL; |
746 | ||
747 | if (!hw_argc) | |
748 | return 0; | |
749 | ||
498f0103 | 750 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
14e98c5c | 751 | |
2bfd2e13 CS |
752 | if (hw_argc > 1) { |
753 | char *p; | |
754 | int i, j, len = 4; | |
755 | ||
756 | for (i = 0; i <= hw_argc - 2; i++) | |
757 | len += strlen(as->argv[i]) + 1; | |
758 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
759 | if (!p) { | |
760 | ti->error = "memory allocation failed"; | |
761 | ret = -ENOMEM; | |
762 | goto fail; | |
763 | } | |
764 | j = sprintf(p, "%d", hw_argc - 1); | |
765 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
766 | j = sprintf(p, "%s", as->argv[i]); | |
767 | } | |
498f0103 | 768 | dm_consume_args(as, hw_argc - 1); |
1da177e4 LT |
769 | |
770 | return 0; | |
2bfd2e13 CS |
771 | fail: |
772 | kfree(m->hw_handler_name); | |
773 | m->hw_handler_name = NULL; | |
774 | return ret; | |
1da177e4 LT |
775 | } |
776 | ||
498f0103 | 777 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
1da177e4 LT |
778 | { |
779 | int r; | |
780 | unsigned argc; | |
28f16c20 | 781 | struct dm_target *ti = m->ti; |
498f0103 | 782 | const char *arg_name; |
1da177e4 | 783 | |
498f0103 | 784 | static struct dm_arg _args[] = { |
a58a935d | 785 | {0, 6, "invalid number of feature args"}, |
c9e45581 | 786 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
4e2d19e4 | 787 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
1da177e4 LT |
788 | }; |
789 | ||
498f0103 | 790 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
1da177e4 LT |
791 | if (r) |
792 | return -EINVAL; | |
793 | ||
794 | if (!argc) | |
795 | return 0; | |
796 | ||
c9e45581 | 797 | do { |
498f0103 | 798 | arg_name = dm_shift_arg(as); |
c9e45581 DW |
799 | argc--; |
800 | ||
498f0103 | 801 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
c9e45581 DW |
802 | r = queue_if_no_path(m, 1, 0); |
803 | continue; | |
804 | } | |
805 | ||
a58a935d MS |
806 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
807 | m->retain_attached_hw_handler = 1; | |
808 | continue; | |
809 | } | |
810 | ||
498f0103 | 811 | if (!strcasecmp(arg_name, "pg_init_retries") && |
c9e45581 | 812 | (argc >= 1)) { |
498f0103 | 813 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
c9e45581 DW |
814 | argc--; |
815 | continue; | |
816 | } | |
817 | ||
498f0103 | 818 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
4e2d19e4 | 819 | (argc >= 1)) { |
498f0103 | 820 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
4e2d19e4 CS |
821 | argc--; |
822 | continue; | |
823 | } | |
824 | ||
1da177e4 | 825 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
826 | r = -EINVAL; |
827 | } while (argc && !r); | |
828 | ||
829 | return r; | |
1da177e4 LT |
830 | } |
831 | ||
832 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
833 | char **argv) | |
834 | { | |
498f0103 MS |
835 | /* target arguments */ |
836 | static struct dm_arg _args[] = { | |
a490a07a MS |
837 | {0, 1024, "invalid number of priority groups"}, |
838 | {0, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
839 | }; |
840 | ||
841 | int r; | |
842 | struct multipath *m; | |
498f0103 | 843 | struct dm_arg_set as; |
1da177e4 LT |
844 | unsigned pg_count = 0; |
845 | unsigned next_pg_num; | |
8637a6bf | 846 | bool use_blk_mq = dm_use_blk_mq(dm_table_get_md(ti->table)); |
1da177e4 LT |
847 | |
848 | as.argc = argc; | |
849 | as.argv = argv; | |
850 | ||
8637a6bf | 851 | m = alloc_multipath(ti, use_blk_mq); |
1da177e4 | 852 | if (!m) { |
72d94861 | 853 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
854 | return -EINVAL; |
855 | } | |
856 | ||
28f16c20 | 857 | r = parse_features(&as, m); |
1da177e4 LT |
858 | if (r) |
859 | goto bad; | |
860 | ||
28f16c20 | 861 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
862 | if (r) |
863 | goto bad; | |
864 | ||
498f0103 | 865 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
1da177e4 LT |
866 | if (r) |
867 | goto bad; | |
868 | ||
498f0103 | 869 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
1da177e4 LT |
870 | if (r) |
871 | goto bad; | |
872 | ||
a490a07a MS |
873 | if ((!m->nr_priority_groups && next_pg_num) || |
874 | (m->nr_priority_groups && !next_pg_num)) { | |
875 | ti->error = "invalid initial priority group"; | |
876 | r = -EINVAL; | |
877 | goto bad; | |
878 | } | |
879 | ||
1da177e4 LT |
880 | /* parse the priority groups */ |
881 | while (as.argc) { | |
882 | struct priority_group *pg; | |
883 | ||
28f16c20 | 884 | pg = parse_priority_group(&as, m); |
01460f35 BM |
885 | if (IS_ERR(pg)) { |
886 | r = PTR_ERR(pg); | |
1da177e4 LT |
887 | goto bad; |
888 | } | |
889 | ||
890 | m->nr_valid_paths += pg->nr_pgpaths; | |
891 | list_add_tail(&pg->list, &m->priority_groups); | |
892 | pg_count++; | |
893 | pg->pg_num = pg_count; | |
894 | if (!--next_pg_num) | |
895 | m->next_pg = pg; | |
896 | } | |
897 | ||
898 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 899 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
900 | r = -EINVAL; |
901 | goto bad; | |
902 | } | |
903 | ||
55a62eef AK |
904 | ti->num_flush_bios = 1; |
905 | ti->num_discard_bios = 1; | |
042bcef8 | 906 | ti->num_write_same_bios = 1; |
8637a6bf MS |
907 | if (use_blk_mq) |
908 | ti->per_io_data_size = sizeof(struct dm_mpath_io); | |
8627921f | 909 | |
1da177e4 LT |
910 | return 0; |
911 | ||
912 | bad: | |
913 | free_multipath(m); | |
914 | return r; | |
915 | } | |
916 | ||
2bded7bd KU |
917 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
918 | { | |
919 | DECLARE_WAITQUEUE(wait, current); | |
920 | unsigned long flags; | |
921 | ||
922 | add_wait_queue(&m->pg_init_wait, &wait); | |
923 | ||
924 | while (1) { | |
925 | set_current_state(TASK_UNINTERRUPTIBLE); | |
926 | ||
927 | spin_lock_irqsave(&m->lock, flags); | |
928 | if (!m->pg_init_in_progress) { | |
929 | spin_unlock_irqrestore(&m->lock, flags); | |
930 | break; | |
931 | } | |
932 | spin_unlock_irqrestore(&m->lock, flags); | |
933 | ||
934 | io_schedule(); | |
935 | } | |
936 | set_current_state(TASK_RUNNING); | |
937 | ||
938 | remove_wait_queue(&m->pg_init_wait, &wait); | |
939 | } | |
940 | ||
941 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 942 | { |
954a73d5 SKM |
943 | unsigned long flags; |
944 | ||
945 | spin_lock_irqsave(&m->lock, flags); | |
946 | m->pg_init_disabled = 1; | |
947 | spin_unlock_irqrestore(&m->lock, flags); | |
948 | ||
bab7cfc7 | 949 | flush_workqueue(kmpath_handlerd); |
2bded7bd | 950 | multipath_wait_for_pg_init_completion(m); |
a044d016 | 951 | flush_workqueue(kmultipathd); |
43829731 | 952 | flush_work(&m->trigger_event); |
954a73d5 SKM |
953 | |
954 | spin_lock_irqsave(&m->lock, flags); | |
955 | m->pg_init_disabled = 0; | |
956 | spin_unlock_irqrestore(&m->lock, flags); | |
6df400ab KU |
957 | } |
958 | ||
959 | static void multipath_dtr(struct dm_target *ti) | |
960 | { | |
961 | struct multipath *m = ti->private; | |
962 | ||
2bded7bd | 963 | flush_multipath_work(m); |
1da177e4 LT |
964 | free_multipath(m); |
965 | } | |
966 | ||
1da177e4 LT |
967 | /* |
968 | * Take a path out of use. | |
969 | */ | |
970 | static int fail_path(struct pgpath *pgpath) | |
971 | { | |
972 | unsigned long flags; | |
973 | struct multipath *m = pgpath->pg->m; | |
974 | ||
975 | spin_lock_irqsave(&m->lock, flags); | |
976 | ||
6680073d | 977 | if (!pgpath->is_active) |
1da177e4 LT |
978 | goto out; |
979 | ||
72d94861 | 980 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
981 | |
982 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
6680073d | 983 | pgpath->is_active = 0; |
1da177e4 LT |
984 | pgpath->fail_count++; |
985 | ||
986 | m->nr_valid_paths--; | |
987 | ||
988 | if (pgpath == m->current_pgpath) | |
989 | m->current_pgpath = NULL; | |
990 | ||
b15546f9 MA |
991 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
992 | pgpath->path.dev->name, m->nr_valid_paths); | |
993 | ||
fe9cf30e | 994 | schedule_work(&m->trigger_event); |
1da177e4 LT |
995 | |
996 | out: | |
997 | spin_unlock_irqrestore(&m->lock, flags); | |
998 | ||
999 | return 0; | |
1000 | } | |
1001 | ||
1002 | /* | |
1003 | * Reinstate a previously-failed path | |
1004 | */ | |
1005 | static int reinstate_path(struct pgpath *pgpath) | |
1006 | { | |
63d832c3 | 1007 | int r = 0, run_queue = 0; |
1da177e4 LT |
1008 | unsigned long flags; |
1009 | struct multipath *m = pgpath->pg->m; | |
1010 | ||
1011 | spin_lock_irqsave(&m->lock, flags); | |
1012 | ||
6680073d | 1013 | if (pgpath->is_active) |
1da177e4 LT |
1014 | goto out; |
1015 | ||
def052d2 | 1016 | if (!pgpath->pg->ps.type->reinstate_path) { |
1da177e4 LT |
1017 | DMWARN("Reinstate path not supported by path selector %s", |
1018 | pgpath->pg->ps.type->name); | |
1019 | r = -EINVAL; | |
1020 | goto out; | |
1021 | } | |
1022 | ||
1023 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1024 | if (r) | |
1025 | goto out; | |
1026 | ||
6680073d | 1027 | pgpath->is_active = 1; |
1da177e4 | 1028 | |
e8099177 | 1029 | if (!m->nr_valid_paths++) { |
e54f77dd | 1030 | m->current_pgpath = NULL; |
63d832c3 | 1031 | run_queue = 1; |
e54f77dd | 1032 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
4e2d19e4 | 1033 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
e54f77dd CS |
1034 | m->pg_init_in_progress++; |
1035 | } | |
1da177e4 | 1036 | |
b15546f9 MA |
1037 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
1038 | pgpath->path.dev->name, m->nr_valid_paths); | |
1039 | ||
fe9cf30e | 1040 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1041 | |
1042 | out: | |
1043 | spin_unlock_irqrestore(&m->lock, flags); | |
63d832c3 HR |
1044 | if (run_queue) |
1045 | dm_table_run_md_queue_async(m->ti->table); | |
1da177e4 LT |
1046 | |
1047 | return r; | |
1048 | } | |
1049 | ||
1050 | /* | |
1051 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1052 | */ | |
1053 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1054 | action_fn action) | |
1055 | { | |
19040c0b | 1056 | int r = -EINVAL; |
1da177e4 LT |
1057 | struct pgpath *pgpath; |
1058 | struct priority_group *pg; | |
1059 | ||
1060 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1061 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1062 | if (pgpath->path.dev == dev) | |
1063 | r = action(pgpath); | |
1064 | } | |
1065 | } | |
1066 | ||
1067 | return r; | |
1068 | } | |
1069 | ||
1070 | /* | |
1071 | * Temporarily try to avoid having to use the specified PG | |
1072 | */ | |
1073 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
1074 | int bypassed) | |
1075 | { | |
1076 | unsigned long flags; | |
1077 | ||
1078 | spin_lock_irqsave(&m->lock, flags); | |
1079 | ||
1080 | pg->bypassed = bypassed; | |
1081 | m->current_pgpath = NULL; | |
1082 | m->current_pg = NULL; | |
1083 | ||
1084 | spin_unlock_irqrestore(&m->lock, flags); | |
1085 | ||
fe9cf30e | 1086 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1087 | } |
1088 | ||
1089 | /* | |
1090 | * Switch to using the specified PG from the next I/O that gets mapped | |
1091 | */ | |
1092 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1093 | { | |
1094 | struct priority_group *pg; | |
1095 | unsigned pgnum; | |
1096 | unsigned long flags; | |
31998ef1 | 1097 | char dummy; |
1da177e4 | 1098 | |
31998ef1 | 1099 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
1da177e4 LT |
1100 | (pgnum > m->nr_priority_groups)) { |
1101 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
1102 | return -EINVAL; | |
1103 | } | |
1104 | ||
1105 | spin_lock_irqsave(&m->lock, flags); | |
1106 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1107 | pg->bypassed = 0; | |
1108 | if (--pgnum) | |
1109 | continue; | |
1110 | ||
1111 | m->current_pgpath = NULL; | |
1112 | m->current_pg = NULL; | |
1113 | m->next_pg = pg; | |
1114 | } | |
1115 | spin_unlock_irqrestore(&m->lock, flags); | |
1116 | ||
fe9cf30e | 1117 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1118 | return 0; |
1119 | } | |
1120 | ||
1121 | /* | |
1122 | * Set/clear bypassed status of a PG. | |
1123 | * PGs are numbered upwards from 1 in the order they were declared. | |
1124 | */ | |
1125 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
1126 | { | |
1127 | struct priority_group *pg; | |
1128 | unsigned pgnum; | |
31998ef1 | 1129 | char dummy; |
1da177e4 | 1130 | |
31998ef1 | 1131 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
1da177e4 LT |
1132 | (pgnum > m->nr_priority_groups)) { |
1133 | DMWARN("invalid PG number supplied to bypass_pg"); | |
1134 | return -EINVAL; | |
1135 | } | |
1136 | ||
1137 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1138 | if (!--pgnum) | |
1139 | break; | |
1140 | } | |
1141 | ||
1142 | bypass_pg(m, pg, bypassed); | |
1143 | return 0; | |
1144 | } | |
1145 | ||
c9e45581 DW |
1146 | /* |
1147 | * Should we retry pg_init immediately? | |
1148 | */ | |
1149 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1150 | { | |
1151 | unsigned long flags; | |
1152 | int limit_reached = 0; | |
1153 | ||
1154 | spin_lock_irqsave(&m->lock, flags); | |
1155 | ||
954a73d5 | 1156 | if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled) |
c9e45581 DW |
1157 | m->pg_init_required = 1; |
1158 | else | |
1159 | limit_reached = 1; | |
1160 | ||
1161 | spin_unlock_irqrestore(&m->lock, flags); | |
1162 | ||
1163 | return limit_reached; | |
1164 | } | |
1165 | ||
3ae31f6a | 1166 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1167 | { |
83c0d5d5 | 1168 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1169 | struct priority_group *pg = pgpath->pg; |
1170 | struct multipath *m = pg->m; | |
1171 | unsigned long flags; | |
4e2d19e4 | 1172 | unsigned delay_retry = 0; |
cfae5c9b CS |
1173 | |
1174 | /* device or driver problems */ | |
1175 | switch (errors) { | |
1176 | case SCSI_DH_OK: | |
1177 | break; | |
1178 | case SCSI_DH_NOSYS: | |
1179 | if (!m->hw_handler_name) { | |
1180 | errors = 0; | |
1181 | break; | |
1182 | } | |
f7b934c8 MB |
1183 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1184 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1185 | /* |
1186 | * Fail path for now, so we do not ping pong | |
1187 | */ | |
1188 | fail_path(pgpath); | |
1189 | break; | |
1190 | case SCSI_DH_DEV_TEMP_BUSY: | |
1191 | /* | |
1192 | * Probably doing something like FW upgrade on the | |
1193 | * controller so try the other pg. | |
1194 | */ | |
1195 | bypass_pg(m, pg, 1); | |
1196 | break; | |
cfae5c9b | 1197 | case SCSI_DH_RETRY: |
4e2d19e4 CS |
1198 | /* Wait before retrying. */ |
1199 | delay_retry = 1; | |
cfae5c9b CS |
1200 | case SCSI_DH_IMM_RETRY: |
1201 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1202 | if (pg_init_limit_reached(m, pgpath)) | |
1203 | fail_path(pgpath); | |
1204 | errors = 0; | |
1205 | break; | |
1206 | default: | |
1207 | /* | |
1208 | * We probably do not want to fail the path for a device | |
1209 | * error, but this is what the old dm did. In future | |
1210 | * patches we can do more advanced handling. | |
1211 | */ | |
1212 | fail_path(pgpath); | |
1213 | } | |
1214 | ||
1215 | spin_lock_irqsave(&m->lock, flags); | |
1216 | if (errors) { | |
e54f77dd CS |
1217 | if (pgpath == m->current_pgpath) { |
1218 | DMERR("Could not failover device. Error %d.", errors); | |
1219 | m->current_pgpath = NULL; | |
1220 | m->current_pg = NULL; | |
1221 | } | |
d0259bf0 | 1222 | } else if (!m->pg_init_required) |
cfae5c9b | 1223 | pg->bypassed = 0; |
cfae5c9b | 1224 | |
d0259bf0 KU |
1225 | if (--m->pg_init_in_progress) |
1226 | /* Activations of other paths are still on going */ | |
1227 | goto out; | |
1228 | ||
3e9f1be1 HR |
1229 | if (m->pg_init_required) { |
1230 | m->pg_init_delay_retry = delay_retry; | |
1231 | if (__pg_init_all_paths(m)) | |
1232 | goto out; | |
1233 | } | |
1234 | m->queue_io = 0; | |
d0259bf0 | 1235 | |
2bded7bd KU |
1236 | /* |
1237 | * Wake up any thread waiting to suspend. | |
1238 | */ | |
1239 | wake_up(&m->pg_init_wait); | |
1240 | ||
d0259bf0 | 1241 | out: |
cfae5c9b CS |
1242 | spin_unlock_irqrestore(&m->lock, flags); |
1243 | } | |
1244 | ||
bab7cfc7 CS |
1245 | static void activate_path(struct work_struct *work) |
1246 | { | |
e54f77dd | 1247 | struct pgpath *pgpath = |
4e2d19e4 | 1248 | container_of(work, struct pgpath, activate_path.work); |
bab7cfc7 | 1249 | |
3a017509 HR |
1250 | if (pgpath->is_active) |
1251 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), | |
1252 | pg_init_done, pgpath); | |
1253 | else | |
1254 | pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); | |
bab7cfc7 CS |
1255 | } |
1256 | ||
7e782af5 HR |
1257 | static int noretry_error(int error) |
1258 | { | |
1259 | switch (error) { | |
1260 | case -EOPNOTSUPP: | |
1261 | case -EREMOTEIO: | |
1262 | case -EILSEQ: | |
1263 | case -ENODATA: | |
cc9d3c38 | 1264 | case -ENOSPC: |
7e782af5 HR |
1265 | return 1; |
1266 | } | |
1267 | ||
1268 | /* Anything else could be a path failure, so should be retried */ | |
1269 | return 0; | |
1270 | } | |
1271 | ||
1da177e4 LT |
1272 | /* |
1273 | * end_io handling | |
1274 | */ | |
f40c67f0 | 1275 | static int do_end_io(struct multipath *m, struct request *clone, |
028867ac | 1276 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1277 | { |
f40c67f0 KU |
1278 | /* |
1279 | * We don't queue any clone request inside the multipath target | |
1280 | * during end I/O handling, since those clone requests don't have | |
1281 | * bio clones. If we queue them inside the multipath target, | |
1282 | * we need to make bio clones, that requires memory allocation. | |
1283 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests | |
1284 | * don't have bio clones.) | |
1285 | * Instead of queueing the clone request here, we queue the original | |
1286 | * request into dm core, which will remake a clone request and | |
1287 | * clone bios for it and resubmit it later. | |
1288 | */ | |
1289 | int r = DM_ENDIO_REQUEUE; | |
640eb3b0 | 1290 | unsigned long flags; |
1da177e4 | 1291 | |
f40c67f0 | 1292 | if (!error && !clone->errors) |
1da177e4 LT |
1293 | return 0; /* I/O complete */ |
1294 | ||
7eee4ae2 | 1295 | if (noretry_error(error)) |
959eb4e5 MS |
1296 | return error; |
1297 | ||
cfae5c9b CS |
1298 | if (mpio->pgpath) |
1299 | fail_path(mpio->pgpath); | |
1da177e4 | 1300 | |
640eb3b0 | 1301 | spin_lock_irqsave(&m->lock, flags); |
751b2a7d HR |
1302 | if (!m->nr_valid_paths) { |
1303 | if (!m->queue_if_no_path) { | |
1304 | if (!__must_push_back(m)) | |
1305 | r = -EIO; | |
1306 | } else { | |
1307 | if (error == -EBADE) | |
1308 | r = error; | |
1309 | } | |
1310 | } | |
640eb3b0 | 1311 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1312 | |
f40c67f0 | 1313 | return r; |
1da177e4 LT |
1314 | } |
1315 | ||
f40c67f0 | 1316 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
1317 | int error, union map_info *map_context) |
1318 | { | |
028867ac AK |
1319 | struct multipath *m = ti->private; |
1320 | struct dm_mpath_io *mpio = map_context->ptr; | |
a71a261f | 1321 | struct pgpath *pgpath; |
1da177e4 LT |
1322 | struct path_selector *ps; |
1323 | int r; | |
1324 | ||
466891f9 JN |
1325 | BUG_ON(!mpio); |
1326 | ||
f40c67f0 | 1327 | r = do_end_io(m, clone, error, mpio); |
a71a261f | 1328 | pgpath = mpio->pgpath; |
1da177e4 LT |
1329 | if (pgpath) { |
1330 | ps = &pgpath->pg->ps; | |
1331 | if (ps->type->end_io) | |
02ab823f | 1332 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
1da177e4 | 1333 | } |
466891f9 | 1334 | clear_mapinfo(m, map_context); |
1da177e4 LT |
1335 | |
1336 | return r; | |
1337 | } | |
1338 | ||
1339 | /* | |
1340 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1341 | * the last path fails we must error any remaining I/O. |
1342 | * Note that if the freeze_bdev fails while suspending, the | |
1343 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1344 | */ |
1345 | static void multipath_presuspend(struct dm_target *ti) | |
1346 | { | |
1347 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1348 | |
485ef69e | 1349 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1350 | } |
1351 | ||
6df400ab KU |
1352 | static void multipath_postsuspend(struct dm_target *ti) |
1353 | { | |
6380f26f MA |
1354 | struct multipath *m = ti->private; |
1355 | ||
1356 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1357 | flush_multipath_work(m); |
6380f26f | 1358 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1359 | } |
1360 | ||
436d4108 AK |
1361 | /* |
1362 | * Restore the queue_if_no_path setting. | |
1363 | */ | |
1da177e4 LT |
1364 | static void multipath_resume(struct dm_target *ti) |
1365 | { | |
1366 | struct multipath *m = (struct multipath *) ti->private; | |
1367 | unsigned long flags; | |
1368 | ||
1369 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1370 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1371 | spin_unlock_irqrestore(&m->lock, flags); |
1372 | } | |
1373 | ||
1374 | /* | |
1375 | * Info output has the following format: | |
1376 | * num_multipath_feature_args [multipath_feature_args]* | |
1377 | * num_handler_status_args [handler_status_args]* | |
1378 | * num_groups init_group_number | |
1379 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1380 | * num_paths num_selector_args | |
1381 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1382 | * | |
1383 | * Table output has the following format (identical to the constructor string): | |
1384 | * num_feature_args [features_args]* | |
1385 | * num_handler_args hw_handler [hw_handler_args]* | |
1386 | * num_groups init_group_number | |
1387 | * [priority selector-name num_ps_args [ps_args]* | |
1388 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1389 | */ | |
fd7c092e MP |
1390 | static void multipath_status(struct dm_target *ti, status_type_t type, |
1391 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
1392 | { |
1393 | int sz = 0; | |
1394 | unsigned long flags; | |
1395 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1396 | struct priority_group *pg; |
1397 | struct pgpath *p; | |
1398 | unsigned pg_num; | |
1399 | char state; | |
1400 | ||
1401 | spin_lock_irqsave(&m->lock, flags); | |
1402 | ||
1403 | /* Features */ | |
1404 | if (type == STATUSTYPE_INFO) | |
e8099177 | 1405 | DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count); |
c9e45581 DW |
1406 | else { |
1407 | DMEMIT("%u ", m->queue_if_no_path + | |
4e2d19e4 | 1408 | (m->pg_init_retries > 0) * 2 + |
a58a935d MS |
1409 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
1410 | m->retain_attached_hw_handler); | |
c9e45581 DW |
1411 | if (m->queue_if_no_path) |
1412 | DMEMIT("queue_if_no_path "); | |
1413 | if (m->pg_init_retries) | |
1414 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
4e2d19e4 CS |
1415 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
1416 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); | |
a58a935d MS |
1417 | if (m->retain_attached_hw_handler) |
1418 | DMEMIT("retain_attached_hw_handler "); | |
c9e45581 | 1419 | } |
1da177e4 | 1420 | |
cfae5c9b | 1421 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1422 | DMEMIT("0 "); |
1423 | else | |
cfae5c9b | 1424 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1425 | |
1426 | DMEMIT("%u ", m->nr_priority_groups); | |
1427 | ||
1428 | if (m->next_pg) | |
1429 | pg_num = m->next_pg->pg_num; | |
1430 | else if (m->current_pg) | |
1431 | pg_num = m->current_pg->pg_num; | |
1432 | else | |
a490a07a | 1433 | pg_num = (m->nr_priority_groups ? 1 : 0); |
1da177e4 LT |
1434 | |
1435 | DMEMIT("%u ", pg_num); | |
1436 | ||
1437 | switch (type) { | |
1438 | case STATUSTYPE_INFO: | |
1439 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1440 | if (pg->bypassed) | |
1441 | state = 'D'; /* Disabled */ | |
1442 | else if (pg == m->current_pg) | |
1443 | state = 'A'; /* Currently Active */ | |
1444 | else | |
1445 | state = 'E'; /* Enabled */ | |
1446 | ||
1447 | DMEMIT("%c ", state); | |
1448 | ||
1449 | if (pg->ps.type->status) | |
1450 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1451 | result + sz, | |
1452 | maxlen - sz); | |
1453 | else | |
1454 | DMEMIT("0 "); | |
1455 | ||
1456 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1457 | pg->ps.type->info_args); | |
1458 | ||
1459 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1460 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1461 | p->is_active ? "A" : "F", |
1da177e4 LT |
1462 | p->fail_count); |
1463 | if (pg->ps.type->status) | |
1464 | sz += pg->ps.type->status(&pg->ps, | |
1465 | &p->path, type, result + sz, | |
1466 | maxlen - sz); | |
1467 | } | |
1468 | } | |
1469 | break; | |
1470 | ||
1471 | case STATUSTYPE_TABLE: | |
1472 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1473 | DMEMIT("%s ", pg->ps.type->name); | |
1474 | ||
1475 | if (pg->ps.type->status) | |
1476 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1477 | result + sz, | |
1478 | maxlen - sz); | |
1479 | else | |
1480 | DMEMIT("0 "); | |
1481 | ||
1482 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1483 | pg->ps.type->table_args); | |
1484 | ||
1485 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1486 | DMEMIT("%s ", p->path.dev->name); | |
1487 | if (pg->ps.type->status) | |
1488 | sz += pg->ps.type->status(&pg->ps, | |
1489 | &p->path, type, result + sz, | |
1490 | maxlen - sz); | |
1491 | } | |
1492 | } | |
1493 | break; | |
1494 | } | |
1495 | ||
1496 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
1497 | } |
1498 | ||
1499 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1500 | { | |
6380f26f | 1501 | int r = -EINVAL; |
1da177e4 LT |
1502 | struct dm_dev *dev; |
1503 | struct multipath *m = (struct multipath *) ti->private; | |
1504 | action_fn action; | |
1505 | ||
6380f26f MA |
1506 | mutex_lock(&m->work_mutex); |
1507 | ||
c2f3d24b KU |
1508 | if (dm_suspended(ti)) { |
1509 | r = -EBUSY; | |
1510 | goto out; | |
1511 | } | |
1512 | ||
1da177e4 | 1513 | if (argc == 1) { |
498f0103 | 1514 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
6380f26f MA |
1515 | r = queue_if_no_path(m, 1, 0); |
1516 | goto out; | |
498f0103 | 1517 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
6380f26f MA |
1518 | r = queue_if_no_path(m, 0, 0); |
1519 | goto out; | |
1520 | } | |
1da177e4 LT |
1521 | } |
1522 | ||
6380f26f | 1523 | if (argc != 2) { |
a356e426 | 1524 | DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); |
6380f26f MA |
1525 | goto out; |
1526 | } | |
1da177e4 | 1527 | |
498f0103 | 1528 | if (!strcasecmp(argv[0], "disable_group")) { |
6380f26f MA |
1529 | r = bypass_pg_num(m, argv[1], 1); |
1530 | goto out; | |
498f0103 | 1531 | } else if (!strcasecmp(argv[0], "enable_group")) { |
6380f26f MA |
1532 | r = bypass_pg_num(m, argv[1], 0); |
1533 | goto out; | |
498f0103 | 1534 | } else if (!strcasecmp(argv[0], "switch_group")) { |
6380f26f MA |
1535 | r = switch_pg_num(m, argv[1]); |
1536 | goto out; | |
498f0103 | 1537 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
1da177e4 | 1538 | action = reinstate_path; |
498f0103 | 1539 | else if (!strcasecmp(argv[0], "fail_path")) |
1da177e4 | 1540 | action = fail_path; |
6380f26f | 1541 | else { |
a356e426 | 1542 | DMWARN("Unrecognised multipath message received: %s", argv[0]); |
6380f26f MA |
1543 | goto out; |
1544 | } | |
1da177e4 | 1545 | |
8215d6ec | 1546 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 1547 | if (r) { |
72d94861 | 1548 | DMWARN("message: error getting device %s", |
1da177e4 | 1549 | argv[1]); |
6380f26f | 1550 | goto out; |
1da177e4 LT |
1551 | } |
1552 | ||
1553 | r = action_dev(m, dev, action); | |
1554 | ||
1555 | dm_put_device(ti, dev); | |
1556 | ||
6380f26f MA |
1557 | out: |
1558 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 1559 | return r; |
1da177e4 LT |
1560 | } |
1561 | ||
e56f81e0 CH |
1562 | static int multipath_prepare_ioctl(struct dm_target *ti, |
1563 | struct block_device **bdev, fmode_t *mode) | |
9af4aa30 | 1564 | { |
35991652 | 1565 | struct multipath *m = ti->private; |
9af4aa30 | 1566 | unsigned long flags; |
35991652 MP |
1567 | int r; |
1568 | ||
9af4aa30 MB |
1569 | spin_lock_irqsave(&m->lock, flags); |
1570 | ||
1571 | if (!m->current_pgpath) | |
02ab823f | 1572 | __choose_pgpath(m, 0); |
9af4aa30 | 1573 | |
43e43c9e JN |
1574 | if (m->current_pgpath) { |
1575 | if (!m->queue_io) { | |
1576 | *bdev = m->current_pgpath->path.dev->bdev; | |
1577 | *mode = m->current_pgpath->path.dev->mode; | |
1578 | r = 0; | |
1579 | } else { | |
1580 | /* pg_init has not started or completed */ | |
1581 | r = -ENOTCONN; | |
1582 | } | |
1583 | } else { | |
1584 | /* No path is available */ | |
1585 | if (m->queue_if_no_path) | |
1586 | r = -ENOTCONN; | |
1587 | else | |
1588 | r = -EIO; | |
e90dae1f | 1589 | } |
9af4aa30 | 1590 | |
9af4aa30 MB |
1591 | spin_unlock_irqrestore(&m->lock, flags); |
1592 | ||
5bbbfdf6 | 1593 | if (r == -ENOTCONN) { |
3e9f1be1 HR |
1594 | spin_lock_irqsave(&m->lock, flags); |
1595 | if (!m->current_pg) { | |
1596 | /* Path status changed, redo selection */ | |
1597 | __choose_pgpath(m, 0); | |
1598 | } | |
1599 | if (m->pg_init_required) | |
1600 | __pg_init_all_paths(m); | |
4cdd2ad7 | 1601 | spin_unlock_irqrestore(&m->lock, flags); |
63d832c3 | 1602 | dm_table_run_md_queue_async(m->ti->table); |
3e9f1be1 | 1603 | } |
35991652 | 1604 | |
e56f81e0 CH |
1605 | /* |
1606 | * Only pass ioctls through if the device sizes match exactly. | |
1607 | */ | |
1608 | if (!r && ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT) | |
1609 | return 1; | |
1610 | return r; | |
9af4aa30 MB |
1611 | } |
1612 | ||
af4874e0 MS |
1613 | static int multipath_iterate_devices(struct dm_target *ti, |
1614 | iterate_devices_callout_fn fn, void *data) | |
1615 | { | |
1616 | struct multipath *m = ti->private; | |
1617 | struct priority_group *pg; | |
1618 | struct pgpath *p; | |
1619 | int ret = 0; | |
1620 | ||
1621 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1622 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 1623 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
1624 | if (ret) |
1625 | goto out; | |
1626 | } | |
1627 | } | |
1628 | ||
1629 | out: | |
1630 | return ret; | |
1631 | } | |
1632 | ||
f40c67f0 KU |
1633 | static int __pgpath_busy(struct pgpath *pgpath) |
1634 | { | |
1635 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
1636 | ||
52b09914 | 1637 | return blk_lld_busy(q); |
f40c67f0 KU |
1638 | } |
1639 | ||
1640 | /* | |
1641 | * We return "busy", only when we can map I/Os but underlying devices | |
1642 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
1643 | * the underlying queue). | |
1644 | * In other words, if we want to kill I/Os or queue them inside us | |
1645 | * due to map unavailability, we don't return "busy". Otherwise, | |
1646 | * dm core won't give us the I/Os and we can't do what we want. | |
1647 | */ | |
1648 | static int multipath_busy(struct dm_target *ti) | |
1649 | { | |
1650 | int busy = 0, has_active = 0; | |
1651 | struct multipath *m = ti->private; | |
1652 | struct priority_group *pg; | |
1653 | struct pgpath *pgpath; | |
1654 | unsigned long flags; | |
1655 | ||
1656 | spin_lock_irqsave(&m->lock, flags); | |
1657 | ||
7a7a3b45 JN |
1658 | /* pg_init in progress or no paths available */ |
1659 | if (m->pg_init_in_progress || | |
1660 | (!m->nr_valid_paths && m->queue_if_no_path)) { | |
b63349a7 HR |
1661 | busy = 1; |
1662 | goto out; | |
1663 | } | |
f40c67f0 KU |
1664 | /* Guess which priority_group will be used at next mapping time */ |
1665 | if (unlikely(!m->current_pgpath && m->next_pg)) | |
1666 | pg = m->next_pg; | |
1667 | else if (likely(m->current_pg)) | |
1668 | pg = m->current_pg; | |
1669 | else | |
1670 | /* | |
1671 | * We don't know which pg will be used at next mapping time. | |
1672 | * We don't call __choose_pgpath() here to avoid to trigger | |
1673 | * pg_init just by busy checking. | |
1674 | * So we don't know whether underlying devices we will be using | |
1675 | * at next mapping time are busy or not. Just try mapping. | |
1676 | */ | |
1677 | goto out; | |
1678 | ||
1679 | /* | |
1680 | * If there is one non-busy active path at least, the path selector | |
1681 | * will be able to select it. So we consider such a pg as not busy. | |
1682 | */ | |
1683 | busy = 1; | |
1684 | list_for_each_entry(pgpath, &pg->pgpaths, list) | |
1685 | if (pgpath->is_active) { | |
1686 | has_active = 1; | |
1687 | ||
1688 | if (!__pgpath_busy(pgpath)) { | |
1689 | busy = 0; | |
1690 | break; | |
1691 | } | |
1692 | } | |
1693 | ||
1694 | if (!has_active) | |
1695 | /* | |
1696 | * No active path in this pg, so this pg won't be used and | |
1697 | * the current_pg will be changed at next mapping time. | |
1698 | * We need to try mapping to determine it. | |
1699 | */ | |
1700 | busy = 0; | |
1701 | ||
1702 | out: | |
1703 | spin_unlock_irqrestore(&m->lock, flags); | |
1704 | ||
1705 | return busy; | |
1706 | } | |
1707 | ||
1da177e4 LT |
1708 | /*----------------------------------------------------------------- |
1709 | * Module setup | |
1710 | *---------------------------------------------------------------*/ | |
1711 | static struct target_type multipath_target = { | |
1712 | .name = "multipath", | |
16f12266 MS |
1713 | .version = {1, 11, 0}, |
1714 | .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE, | |
1da177e4 LT |
1715 | .module = THIS_MODULE, |
1716 | .ctr = multipath_ctr, | |
1717 | .dtr = multipath_dtr, | |
f40c67f0 | 1718 | .map_rq = multipath_map, |
e5863d9a MS |
1719 | .clone_and_map_rq = multipath_clone_and_map, |
1720 | .release_clone_rq = multipath_release_clone, | |
f40c67f0 | 1721 | .rq_end_io = multipath_end_io, |
1da177e4 | 1722 | .presuspend = multipath_presuspend, |
6df400ab | 1723 | .postsuspend = multipath_postsuspend, |
1da177e4 LT |
1724 | .resume = multipath_resume, |
1725 | .status = multipath_status, | |
1726 | .message = multipath_message, | |
e56f81e0 | 1727 | .prepare_ioctl = multipath_prepare_ioctl, |
af4874e0 | 1728 | .iterate_devices = multipath_iterate_devices, |
f40c67f0 | 1729 | .busy = multipath_busy, |
1da177e4 LT |
1730 | }; |
1731 | ||
1732 | static int __init dm_multipath_init(void) | |
1733 | { | |
1734 | int r; | |
1735 | ||
1736 | /* allocate a slab for the dm_ios */ | |
028867ac | 1737 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1738 | if (!_mpio_cache) |
1739 | return -ENOMEM; | |
1740 | ||
1741 | r = dm_register_target(&multipath_target); | |
1742 | if (r < 0) { | |
0cd33124 | 1743 | DMERR("register failed %d", r); |
ff658e9c JT |
1744 | r = -EINVAL; |
1745 | goto bad_register_target; | |
1da177e4 LT |
1746 | } |
1747 | ||
4d4d66ab | 1748 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
c557308e | 1749 | if (!kmultipathd) { |
0cd33124 | 1750 | DMERR("failed to create workqueue kmpathd"); |
ff658e9c JT |
1751 | r = -ENOMEM; |
1752 | goto bad_alloc_kmultipathd; | |
c557308e AK |
1753 | } |
1754 | ||
bab7cfc7 CS |
1755 | /* |
1756 | * A separate workqueue is used to handle the device handlers | |
1757 | * to avoid overloading existing workqueue. Overloading the | |
1758 | * old workqueue would also create a bottleneck in the | |
1759 | * path of the storage hardware device activation. | |
1760 | */ | |
4d4d66ab TH |
1761 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
1762 | WQ_MEM_RECLAIM); | |
bab7cfc7 CS |
1763 | if (!kmpath_handlerd) { |
1764 | DMERR("failed to create workqueue kmpath_handlerd"); | |
ff658e9c JT |
1765 | r = -ENOMEM; |
1766 | goto bad_alloc_kmpath_handlerd; | |
bab7cfc7 CS |
1767 | } |
1768 | ||
72d94861 | 1769 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1770 | multipath_target.version[0], multipath_target.version[1], |
1771 | multipath_target.version[2]); | |
1772 | ||
ff658e9c JT |
1773 | return 0; |
1774 | ||
1775 | bad_alloc_kmpath_handlerd: | |
1776 | destroy_workqueue(kmultipathd); | |
1777 | bad_alloc_kmultipathd: | |
1778 | dm_unregister_target(&multipath_target); | |
1779 | bad_register_target: | |
1780 | kmem_cache_destroy(_mpio_cache); | |
1781 | ||
1da177e4 LT |
1782 | return r; |
1783 | } | |
1784 | ||
1785 | static void __exit dm_multipath_exit(void) | |
1786 | { | |
bab7cfc7 | 1787 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1788 | destroy_workqueue(kmultipathd); |
1789 | ||
10d3bd09 | 1790 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
1791 | kmem_cache_destroy(_mpio_cache); |
1792 | } | |
1793 | ||
1da177e4 LT |
1794 | module_init(dm_multipath_init); |
1795 | module_exit(dm_multipath_exit); | |
1796 | ||
1797 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1798 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1799 | MODULE_LICENSE("GPL"); |