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 | ||
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; | |
ae11b1b3 | 162 | struct multipath *m = ti->private; |
1da177e4 LT |
163 | |
164 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
165 | list_del(&pgpath->list); | |
ae11b1b3 HR |
166 | if (m->hw_handler_name) |
167 | scsi_dh_detach(bdev_get_queue(pgpath->path.dev->bdev)); | |
1da177e4 LT |
168 | dm_put_device(ti, pgpath->path.dev); |
169 | free_pgpath(pgpath); | |
170 | } | |
171 | } | |
172 | ||
173 | static void free_priority_group(struct priority_group *pg, | |
174 | struct dm_target *ti) | |
175 | { | |
176 | struct path_selector *ps = &pg->ps; | |
177 | ||
178 | if (ps->type) { | |
179 | ps->type->destroy(ps); | |
180 | dm_put_path_selector(ps->type); | |
181 | } | |
182 | ||
183 | free_pgpaths(&pg->pgpaths, ti); | |
184 | kfree(pg); | |
185 | } | |
186 | ||
28f16c20 | 187 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
188 | { |
189 | struct multipath *m; | |
f4790826 | 190 | unsigned min_ios = dm_get_reserved_rq_based_ios(); |
1da177e4 | 191 | |
e69fae56 | 192 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 193 | if (m) { |
1da177e4 LT |
194 | INIT_LIST_HEAD(&m->priority_groups); |
195 | spin_lock_init(&m->lock); | |
196 | m->queue_io = 1; | |
4e2d19e4 | 197 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; |
c4028958 | 198 | INIT_WORK(&m->trigger_event, trigger_event); |
2bded7bd | 199 | init_waitqueue_head(&m->pg_init_wait); |
6380f26f | 200 | mutex_init(&m->work_mutex); |
f4790826 | 201 | m->mpio_pool = mempool_create_slab_pool(min_ios, _mpio_cache); |
1da177e4 LT |
202 | if (!m->mpio_pool) { |
203 | kfree(m); | |
204 | return NULL; | |
205 | } | |
28f16c20 MM |
206 | m->ti = ti; |
207 | ti->private = m; | |
1da177e4 LT |
208 | } |
209 | ||
210 | return m; | |
211 | } | |
212 | ||
213 | static void free_multipath(struct multipath *m) | |
214 | { | |
215 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
216 | |
217 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
218 | list_del(&pg->list); | |
219 | free_priority_group(pg, m->ti); | |
220 | } | |
221 | ||
cfae5c9b | 222 | kfree(m->hw_handler_name); |
2bfd2e13 | 223 | kfree(m->hw_handler_params); |
1da177e4 LT |
224 | mempool_destroy(m->mpio_pool); |
225 | kfree(m); | |
226 | } | |
227 | ||
466891f9 JN |
228 | static int set_mapinfo(struct multipath *m, union map_info *info) |
229 | { | |
230 | struct dm_mpath_io *mpio; | |
231 | ||
232 | mpio = mempool_alloc(m->mpio_pool, GFP_ATOMIC); | |
233 | if (!mpio) | |
234 | return -ENOMEM; | |
235 | ||
236 | memset(mpio, 0, sizeof(*mpio)); | |
237 | info->ptr = mpio; | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static void clear_mapinfo(struct multipath *m, union map_info *info) | |
243 | { | |
244 | struct dm_mpath_io *mpio = info->ptr; | |
245 | ||
246 | info->ptr = NULL; | |
247 | mempool_free(mpio, m->mpio_pool); | |
248 | } | |
1da177e4 LT |
249 | |
250 | /*----------------------------------------------- | |
251 | * Path selection | |
252 | *-----------------------------------------------*/ | |
253 | ||
3e9f1be1 | 254 | static int __pg_init_all_paths(struct multipath *m) |
fb612642 KU |
255 | { |
256 | struct pgpath *pgpath; | |
4e2d19e4 | 257 | unsigned long pg_init_delay = 0; |
fb612642 | 258 | |
17f4ff45 | 259 | if (m->pg_init_in_progress || m->pg_init_disabled) |
3e9f1be1 | 260 | return 0; |
17f4ff45 | 261 | |
fb612642 KU |
262 | m->pg_init_count++; |
263 | m->pg_init_required = 0; | |
3e9f1be1 HR |
264 | |
265 | /* Check here to reset pg_init_required */ | |
266 | if (!m->current_pg) | |
267 | return 0; | |
268 | ||
4e2d19e4 CS |
269 | if (m->pg_init_delay_retry) |
270 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? | |
271 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); | |
fb612642 KU |
272 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
273 | /* Skip failed paths */ | |
274 | if (!pgpath->is_active) | |
275 | continue; | |
4e2d19e4 CS |
276 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
277 | pg_init_delay)) | |
fb612642 KU |
278 | m->pg_init_in_progress++; |
279 | } | |
3e9f1be1 | 280 | return m->pg_init_in_progress; |
fb612642 KU |
281 | } |
282 | ||
1da177e4 LT |
283 | static void __switch_pg(struct multipath *m, struct pgpath *pgpath) |
284 | { | |
1da177e4 LT |
285 | m->current_pg = pgpath->pg; |
286 | ||
287 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 288 | if (m->hw_handler_name) { |
1da177e4 LT |
289 | m->pg_init_required = 1; |
290 | m->queue_io = 1; | |
291 | } else { | |
292 | m->pg_init_required = 0; | |
293 | m->queue_io = 0; | |
294 | } | |
c9e45581 DW |
295 | |
296 | m->pg_init_count = 0; | |
1da177e4 LT |
297 | } |
298 | ||
02ab823f KU |
299 | static int __choose_path_in_pg(struct multipath *m, struct priority_group *pg, |
300 | size_t nr_bytes) | |
1da177e4 | 301 | { |
c922d5f7 | 302 | struct dm_path *path; |
1da177e4 | 303 | |
02ab823f | 304 | path = pg->ps.type->select_path(&pg->ps, &m->repeat_count, nr_bytes); |
1da177e4 LT |
305 | if (!path) |
306 | return -ENXIO; | |
307 | ||
308 | m->current_pgpath = path_to_pgpath(path); | |
309 | ||
310 | if (m->current_pg != pg) | |
311 | __switch_pg(m, m->current_pgpath); | |
312 | ||
313 | return 0; | |
314 | } | |
315 | ||
02ab823f | 316 | static void __choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 LT |
317 | { |
318 | struct priority_group *pg; | |
319 | unsigned bypassed = 1; | |
320 | ||
1f271972 BM |
321 | if (!m->nr_valid_paths) { |
322 | m->queue_io = 0; | |
1da177e4 | 323 | goto failed; |
1f271972 | 324 | } |
1da177e4 LT |
325 | |
326 | /* Were we instructed to switch PG? */ | |
327 | if (m->next_pg) { | |
328 | pg = m->next_pg; | |
329 | m->next_pg = NULL; | |
02ab823f | 330 | if (!__choose_path_in_pg(m, pg, nr_bytes)) |
1da177e4 LT |
331 | return; |
332 | } | |
333 | ||
334 | /* Don't change PG until it has no remaining paths */ | |
02ab823f | 335 | if (m->current_pg && !__choose_path_in_pg(m, m->current_pg, nr_bytes)) |
1da177e4 LT |
336 | return; |
337 | ||
338 | /* | |
339 | * Loop through priority groups until we find a valid path. | |
340 | * First time we skip PGs marked 'bypassed'. | |
f220fd4e MC |
341 | * Second time we only try the ones we skipped, but set |
342 | * pg_init_delay_retry so we do not hammer controllers. | |
1da177e4 LT |
343 | */ |
344 | do { | |
345 | list_for_each_entry(pg, &m->priority_groups, list) { | |
346 | if (pg->bypassed == bypassed) | |
347 | continue; | |
f220fd4e MC |
348 | if (!__choose_path_in_pg(m, pg, nr_bytes)) { |
349 | if (!bypassed) | |
350 | m->pg_init_delay_retry = 1; | |
1da177e4 | 351 | return; |
f220fd4e | 352 | } |
1da177e4 LT |
353 | } |
354 | } while (bypassed--); | |
355 | ||
356 | failed: | |
357 | m->current_pgpath = NULL; | |
358 | m->current_pg = NULL; | |
359 | } | |
360 | ||
45e15720 KU |
361 | /* |
362 | * Check whether bios must be queued in the device-mapper core rather | |
363 | * than here in the target. | |
364 | * | |
365 | * m->lock must be held on entry. | |
366 | * | |
367 | * If m->queue_if_no_path and m->saved_queue_if_no_path hold the | |
368 | * same value then we are not between multipath_presuspend() | |
369 | * and multipath_resume() calls and we have no need to check | |
370 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
371 | */ | |
372 | static int __must_push_back(struct multipath *m) | |
373 | { | |
e8099177 HR |
374 | return (m->queue_if_no_path || |
375 | (m->queue_if_no_path != m->saved_queue_if_no_path && | |
376 | dm_noflush_suspending(m->ti))); | |
45e15720 KU |
377 | } |
378 | ||
36fcffcc HR |
379 | /* |
380 | * Map cloned requests | |
381 | */ | |
e5863d9a MS |
382 | static int __multipath_map(struct dm_target *ti, struct request *clone, |
383 | union map_info *map_context, | |
384 | struct request *rq, struct request **__clone) | |
1da177e4 | 385 | { |
36fcffcc | 386 | struct multipath *m = (struct multipath *) ti->private; |
e3bde04f | 387 | int r = DM_MAPIO_REQUEUE; |
e5863d9a | 388 | size_t nr_bytes = clone ? blk_rq_bytes(clone) : blk_rq_bytes(rq); |
1da177e4 | 389 | struct pgpath *pgpath; |
f40c67f0 | 390 | struct block_device *bdev; |
e3bde04f | 391 | struct dm_mpath_io *mpio; |
1da177e4 | 392 | |
2eb6e1e3 | 393 | spin_lock_irq(&m->lock); |
1da177e4 LT |
394 | |
395 | /* Do we need to select a new pgpath? */ | |
396 | if (!m->current_pgpath || | |
397 | (!m->queue_io && (m->repeat_count && --m->repeat_count == 0))) | |
02ab823f | 398 | __choose_pgpath(m, nr_bytes); |
1da177e4 LT |
399 | |
400 | pgpath = m->current_pgpath; | |
401 | ||
9bf59a61 MS |
402 | if (!pgpath) { |
403 | if (!__must_push_back(m)) | |
404 | r = -EIO; /* Failed */ | |
405 | goto out_unlock; | |
6afbc01d | 406 | } else if (m->queue_io || m->pg_init_required) { |
e3bde04f | 407 | __pg_init_all_paths(m); |
9bf59a61 MS |
408 | goto out_unlock; |
409 | } | |
6afbc01d | 410 | |
9bf59a61 MS |
411 | if (set_mapinfo(m, map_context) < 0) |
412 | /* ENOMEM, requeue */ | |
413 | goto out_unlock; | |
414 | ||
2eb6e1e3 KB |
415 | mpio = map_context->ptr; |
416 | mpio->pgpath = pgpath; | |
417 | mpio->nr_bytes = nr_bytes; | |
418 | ||
9bf59a61 | 419 | bdev = pgpath->path.dev->bdev; |
2eb6e1e3 | 420 | |
2eb6e1e3 KB |
421 | spin_unlock_irq(&m->lock); |
422 | ||
e5863d9a MS |
423 | if (clone) { |
424 | /* Old request-based interface: allocated clone is passed in */ | |
425 | clone->q = bdev_get_queue(bdev); | |
426 | clone->rq_disk = bdev->bd_disk; | |
427 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; | |
428 | } else { | |
429 | /* blk-mq request-based interface */ | |
430 | *__clone = blk_get_request(bdev_get_queue(bdev), | |
02233342 | 431 | rq_data_dir(rq), GFP_ATOMIC); |
4c6dd53d | 432 | if (IS_ERR(*__clone)) { |
e5863d9a | 433 | /* ENOMEM, requeue */ |
4c6dd53d | 434 | clear_mapinfo(m, map_context); |
e5863d9a | 435 | return r; |
4c6dd53d | 436 | } |
e5863d9a MS |
437 | (*__clone)->bio = (*__clone)->biotail = NULL; |
438 | (*__clone)->rq_disk = bdev->bd_disk; | |
439 | (*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT; | |
440 | } | |
441 | ||
9bf59a61 MS |
442 | if (pgpath->pg->ps.type->start_io) |
443 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
444 | &pgpath->path, | |
445 | nr_bytes); | |
2eb6e1e3 | 446 | return DM_MAPIO_REMAPPED; |
1da177e4 | 447 | |
e3bde04f | 448 | out_unlock: |
2eb6e1e3 | 449 | spin_unlock_irq(&m->lock); |
1da177e4 LT |
450 | |
451 | return r; | |
452 | } | |
453 | ||
e5863d9a MS |
454 | static int multipath_map(struct dm_target *ti, struct request *clone, |
455 | union map_info *map_context) | |
456 | { | |
457 | return __multipath_map(ti, clone, map_context, NULL, NULL); | |
458 | } | |
459 | ||
460 | static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, | |
461 | union map_info *map_context, | |
462 | struct request **clone) | |
463 | { | |
464 | return __multipath_map(ti, NULL, map_context, rq, clone); | |
465 | } | |
466 | ||
467 | static void multipath_release_clone(struct request *clone) | |
468 | { | |
469 | blk_put_request(clone); | |
470 | } | |
471 | ||
1da177e4 LT |
472 | /* |
473 | * If we run out of usable paths, should we queue I/O or error it? | |
474 | */ | |
485ef69e AK |
475 | static int queue_if_no_path(struct multipath *m, unsigned queue_if_no_path, |
476 | unsigned save_old_value) | |
1da177e4 LT |
477 | { |
478 | unsigned long flags; | |
479 | ||
480 | spin_lock_irqsave(&m->lock, flags); | |
481 | ||
485ef69e AK |
482 | if (save_old_value) |
483 | m->saved_queue_if_no_path = m->queue_if_no_path; | |
484 | else | |
485 | m->saved_queue_if_no_path = queue_if_no_path; | |
1da177e4 | 486 | m->queue_if_no_path = queue_if_no_path; |
1da177e4 LT |
487 | spin_unlock_irqrestore(&m->lock, flags); |
488 | ||
63d832c3 HR |
489 | if (!queue_if_no_path) |
490 | dm_table_run_md_queue_async(m->ti->table); | |
491 | ||
1da177e4 LT |
492 | return 0; |
493 | } | |
494 | ||
1da177e4 LT |
495 | /* |
496 | * An event is triggered whenever a path is taken out of use. | |
497 | * Includes path failure and PG bypass. | |
498 | */ | |
c4028958 | 499 | static void trigger_event(struct work_struct *work) |
1da177e4 | 500 | { |
c4028958 DH |
501 | struct multipath *m = |
502 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
503 | |
504 | dm_table_event(m->ti->table); | |
505 | } | |
506 | ||
507 | /*----------------------------------------------------------------- | |
508 | * Constructor/argument parsing: | |
509 | * <#multipath feature args> [<arg>]* | |
510 | * <#hw_handler args> [hw_handler [<arg>]*] | |
511 | * <#priority groups> | |
512 | * <initial priority group> | |
513 | * [<selector> <#selector args> [<arg>]* | |
514 | * <#paths> <#per-path selector args> | |
515 | * [<path> [<arg>]* ]+ ]+ | |
516 | *---------------------------------------------------------------*/ | |
498f0103 | 517 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
1da177e4 LT |
518 | struct dm_target *ti) |
519 | { | |
520 | int r; | |
521 | struct path_selector_type *pst; | |
522 | unsigned ps_argc; | |
523 | ||
498f0103 | 524 | static struct dm_arg _args[] = { |
72d94861 | 525 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
526 | }; |
527 | ||
498f0103 | 528 | pst = dm_get_path_selector(dm_shift_arg(as)); |
1da177e4 | 529 | if (!pst) { |
72d94861 | 530 | ti->error = "unknown path selector type"; |
1da177e4 LT |
531 | return -EINVAL; |
532 | } | |
533 | ||
498f0103 | 534 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
371b2e34 MP |
535 | if (r) { |
536 | dm_put_path_selector(pst); | |
1da177e4 | 537 | return -EINVAL; |
371b2e34 | 538 | } |
1da177e4 LT |
539 | |
540 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
541 | if (r) { | |
542 | dm_put_path_selector(pst); | |
72d94861 | 543 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
544 | return r; |
545 | } | |
546 | ||
547 | pg->ps.type = pst; | |
498f0103 | 548 | dm_consume_args(as, ps_argc); |
1da177e4 LT |
549 | |
550 | return 0; | |
551 | } | |
552 | ||
498f0103 | 553 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, |
1da177e4 LT |
554 | struct dm_target *ti) |
555 | { | |
556 | int r; | |
557 | struct pgpath *p; | |
ae11b1b3 | 558 | struct multipath *m = ti->private; |
a58a935d MS |
559 | struct request_queue *q = NULL; |
560 | const char *attached_handler_name; | |
1da177e4 LT |
561 | |
562 | /* we need at least a path arg */ | |
563 | if (as->argc < 1) { | |
72d94861 | 564 | ti->error = "no device given"; |
01460f35 | 565 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
566 | } |
567 | ||
568 | p = alloc_pgpath(); | |
569 | if (!p) | |
01460f35 | 570 | return ERR_PTR(-ENOMEM); |
1da177e4 | 571 | |
498f0103 | 572 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), |
8215d6ec | 573 | &p->path.dev); |
1da177e4 | 574 | if (r) { |
72d94861 | 575 | ti->error = "error getting device"; |
1da177e4 LT |
576 | goto bad; |
577 | } | |
578 | ||
a58a935d MS |
579 | if (m->retain_attached_hw_handler || m->hw_handler_name) |
580 | q = bdev_get_queue(p->path.dev->bdev); | |
581 | ||
582 | if (m->retain_attached_hw_handler) { | |
583 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); | |
584 | if (attached_handler_name) { | |
585 | /* | |
586 | * Reset hw_handler_name to match the attached handler | |
587 | * and clear any hw_handler_params associated with the | |
588 | * ignored handler. | |
589 | * | |
590 | * NB. This modifies the table line to show the actual | |
591 | * handler instead of the original table passed in. | |
592 | */ | |
593 | kfree(m->hw_handler_name); | |
594 | m->hw_handler_name = attached_handler_name; | |
595 | ||
596 | kfree(m->hw_handler_params); | |
597 | m->hw_handler_params = NULL; | |
598 | } | |
599 | } | |
a0cf7ea9 | 600 | |
a58a935d MS |
601 | if (m->hw_handler_name) { |
602 | /* | |
603 | * Increments scsi_dh reference, even when using an | |
604 | * already-attached handler. | |
605 | */ | |
a0cf7ea9 HR |
606 | r = scsi_dh_attach(q, m->hw_handler_name); |
607 | if (r == -EBUSY) { | |
608 | /* | |
a58a935d | 609 | * Already attached to different hw_handler: |
a0cf7ea9 HR |
610 | * try to reattach with correct one. |
611 | */ | |
612 | scsi_dh_detach(q); | |
613 | r = scsi_dh_attach(q, m->hw_handler_name); | |
614 | } | |
615 | ||
ae11b1b3 | 616 | if (r < 0) { |
a0cf7ea9 | 617 | ti->error = "error attaching hardware handler"; |
ae11b1b3 HR |
618 | dm_put_device(ti, p->path.dev); |
619 | goto bad; | |
620 | } | |
2bfd2e13 CS |
621 | |
622 | if (m->hw_handler_params) { | |
623 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
624 | if (r < 0) { | |
625 | ti->error = "unable to set hardware " | |
626 | "handler parameters"; | |
627 | scsi_dh_detach(q); | |
628 | dm_put_device(ti, p->path.dev); | |
629 | goto bad; | |
630 | } | |
631 | } | |
ae11b1b3 HR |
632 | } |
633 | ||
1da177e4 LT |
634 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
635 | if (r) { | |
636 | dm_put_device(ti, p->path.dev); | |
637 | goto bad; | |
638 | } | |
639 | ||
640 | return p; | |
641 | ||
642 | bad: | |
643 | free_pgpath(p); | |
01460f35 | 644 | return ERR_PTR(r); |
1da177e4 LT |
645 | } |
646 | ||
498f0103 | 647 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
28f16c20 | 648 | struct multipath *m) |
1da177e4 | 649 | { |
498f0103 | 650 | static struct dm_arg _args[] = { |
72d94861 AK |
651 | {1, 1024, "invalid number of paths"}, |
652 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
653 | }; |
654 | ||
655 | int r; | |
498f0103 | 656 | unsigned i, nr_selector_args, nr_args; |
1da177e4 | 657 | struct priority_group *pg; |
28f16c20 | 658 | struct dm_target *ti = m->ti; |
1da177e4 LT |
659 | |
660 | if (as->argc < 2) { | |
661 | as->argc = 0; | |
01460f35 BM |
662 | ti->error = "not enough priority group arguments"; |
663 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
664 | } |
665 | ||
666 | pg = alloc_priority_group(); | |
667 | if (!pg) { | |
72d94861 | 668 | ti->error = "couldn't allocate priority group"; |
01460f35 | 669 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
670 | } |
671 | pg->m = m; | |
672 | ||
673 | r = parse_path_selector(as, pg, ti); | |
674 | if (r) | |
675 | goto bad; | |
676 | ||
677 | /* | |
678 | * read the paths | |
679 | */ | |
498f0103 | 680 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
1da177e4 LT |
681 | if (r) |
682 | goto bad; | |
683 | ||
498f0103 | 684 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
1da177e4 LT |
685 | if (r) |
686 | goto bad; | |
687 | ||
498f0103 | 688 | nr_args = 1 + nr_selector_args; |
1da177e4 LT |
689 | for (i = 0; i < pg->nr_pgpaths; i++) { |
690 | struct pgpath *pgpath; | |
498f0103 | 691 | struct dm_arg_set path_args; |
1da177e4 | 692 | |
498f0103 | 693 | if (as->argc < nr_args) { |
148acff6 | 694 | ti->error = "not enough path parameters"; |
6bbf79a1 | 695 | r = -EINVAL; |
1da177e4 | 696 | goto bad; |
148acff6 | 697 | } |
1da177e4 | 698 | |
498f0103 | 699 | path_args.argc = nr_args; |
1da177e4 LT |
700 | path_args.argv = as->argv; |
701 | ||
702 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
703 | if (IS_ERR(pgpath)) { |
704 | r = PTR_ERR(pgpath); | |
1da177e4 | 705 | goto bad; |
01460f35 | 706 | } |
1da177e4 LT |
707 | |
708 | pgpath->pg = pg; | |
709 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
498f0103 | 710 | dm_consume_args(as, nr_args); |
1da177e4 LT |
711 | } |
712 | ||
713 | return pg; | |
714 | ||
715 | bad: | |
716 | free_priority_group(pg, ti); | |
01460f35 | 717 | return ERR_PTR(r); |
1da177e4 LT |
718 | } |
719 | ||
498f0103 | 720 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
1da177e4 | 721 | { |
1da177e4 | 722 | unsigned hw_argc; |
2bfd2e13 | 723 | int ret; |
28f16c20 | 724 | struct dm_target *ti = m->ti; |
1da177e4 | 725 | |
498f0103 | 726 | static struct dm_arg _args[] = { |
72d94861 | 727 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
728 | }; |
729 | ||
498f0103 | 730 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
1da177e4 LT |
731 | return -EINVAL; |
732 | ||
733 | if (!hw_argc) | |
734 | return 0; | |
735 | ||
498f0103 | 736 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
510193a2 MS |
737 | if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name), |
738 | "scsi_dh_%s", m->hw_handler_name)) { | |
72d94861 | 739 | ti->error = "unknown hardware handler type"; |
2bfd2e13 CS |
740 | ret = -EINVAL; |
741 | goto fail; | |
1da177e4 | 742 | } |
14e98c5c | 743 | |
2bfd2e13 CS |
744 | if (hw_argc > 1) { |
745 | char *p; | |
746 | int i, j, len = 4; | |
747 | ||
748 | for (i = 0; i <= hw_argc - 2; i++) | |
749 | len += strlen(as->argv[i]) + 1; | |
750 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
751 | if (!p) { | |
752 | ti->error = "memory allocation failed"; | |
753 | ret = -ENOMEM; | |
754 | goto fail; | |
755 | } | |
756 | j = sprintf(p, "%d", hw_argc - 1); | |
757 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
758 | j = sprintf(p, "%s", as->argv[i]); | |
759 | } | |
498f0103 | 760 | dm_consume_args(as, hw_argc - 1); |
1da177e4 LT |
761 | |
762 | return 0; | |
2bfd2e13 CS |
763 | fail: |
764 | kfree(m->hw_handler_name); | |
765 | m->hw_handler_name = NULL; | |
766 | return ret; | |
1da177e4 LT |
767 | } |
768 | ||
498f0103 | 769 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
1da177e4 LT |
770 | { |
771 | int r; | |
772 | unsigned argc; | |
28f16c20 | 773 | struct dm_target *ti = m->ti; |
498f0103 | 774 | const char *arg_name; |
1da177e4 | 775 | |
498f0103 | 776 | static struct dm_arg _args[] = { |
a58a935d | 777 | {0, 6, "invalid number of feature args"}, |
c9e45581 | 778 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
4e2d19e4 | 779 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
1da177e4 LT |
780 | }; |
781 | ||
498f0103 | 782 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
1da177e4 LT |
783 | if (r) |
784 | return -EINVAL; | |
785 | ||
786 | if (!argc) | |
787 | return 0; | |
788 | ||
c9e45581 | 789 | do { |
498f0103 | 790 | arg_name = dm_shift_arg(as); |
c9e45581 DW |
791 | argc--; |
792 | ||
498f0103 | 793 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
c9e45581 DW |
794 | r = queue_if_no_path(m, 1, 0); |
795 | continue; | |
796 | } | |
797 | ||
a58a935d MS |
798 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
799 | m->retain_attached_hw_handler = 1; | |
800 | continue; | |
801 | } | |
802 | ||
498f0103 | 803 | if (!strcasecmp(arg_name, "pg_init_retries") && |
c9e45581 | 804 | (argc >= 1)) { |
498f0103 | 805 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
c9e45581 DW |
806 | argc--; |
807 | continue; | |
808 | } | |
809 | ||
498f0103 | 810 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
4e2d19e4 | 811 | (argc >= 1)) { |
498f0103 | 812 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
4e2d19e4 CS |
813 | argc--; |
814 | continue; | |
815 | } | |
816 | ||
1da177e4 | 817 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
818 | r = -EINVAL; |
819 | } while (argc && !r); | |
820 | ||
821 | return r; | |
1da177e4 LT |
822 | } |
823 | ||
824 | static int multipath_ctr(struct dm_target *ti, unsigned int argc, | |
825 | char **argv) | |
826 | { | |
498f0103 MS |
827 | /* target arguments */ |
828 | static struct dm_arg _args[] = { | |
a490a07a MS |
829 | {0, 1024, "invalid number of priority groups"}, |
830 | {0, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
831 | }; |
832 | ||
833 | int r; | |
834 | struct multipath *m; | |
498f0103 | 835 | struct dm_arg_set as; |
1da177e4 LT |
836 | unsigned pg_count = 0; |
837 | unsigned next_pg_num; | |
838 | ||
839 | as.argc = argc; | |
840 | as.argv = argv; | |
841 | ||
28f16c20 | 842 | m = alloc_multipath(ti); |
1da177e4 | 843 | if (!m) { |
72d94861 | 844 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
845 | return -EINVAL; |
846 | } | |
847 | ||
28f16c20 | 848 | r = parse_features(&as, m); |
1da177e4 LT |
849 | if (r) |
850 | goto bad; | |
851 | ||
28f16c20 | 852 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
853 | if (r) |
854 | goto bad; | |
855 | ||
498f0103 | 856 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
1da177e4 LT |
857 | if (r) |
858 | goto bad; | |
859 | ||
498f0103 | 860 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
1da177e4 LT |
861 | if (r) |
862 | goto bad; | |
863 | ||
a490a07a MS |
864 | if ((!m->nr_priority_groups && next_pg_num) || |
865 | (m->nr_priority_groups && !next_pg_num)) { | |
866 | ti->error = "invalid initial priority group"; | |
867 | r = -EINVAL; | |
868 | goto bad; | |
869 | } | |
870 | ||
1da177e4 LT |
871 | /* parse the priority groups */ |
872 | while (as.argc) { | |
873 | struct priority_group *pg; | |
874 | ||
28f16c20 | 875 | pg = parse_priority_group(&as, m); |
01460f35 BM |
876 | if (IS_ERR(pg)) { |
877 | r = PTR_ERR(pg); | |
1da177e4 LT |
878 | goto bad; |
879 | } | |
880 | ||
881 | m->nr_valid_paths += pg->nr_pgpaths; | |
882 | list_add_tail(&pg->list, &m->priority_groups); | |
883 | pg_count++; | |
884 | pg->pg_num = pg_count; | |
885 | if (!--next_pg_num) | |
886 | m->next_pg = pg; | |
887 | } | |
888 | ||
889 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 890 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
891 | r = -EINVAL; |
892 | goto bad; | |
893 | } | |
894 | ||
55a62eef AK |
895 | ti->num_flush_bios = 1; |
896 | ti->num_discard_bios = 1; | |
042bcef8 | 897 | ti->num_write_same_bios = 1; |
8627921f | 898 | |
1da177e4 LT |
899 | return 0; |
900 | ||
901 | bad: | |
902 | free_multipath(m); | |
903 | return r; | |
904 | } | |
905 | ||
2bded7bd KU |
906 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
907 | { | |
908 | DECLARE_WAITQUEUE(wait, current); | |
909 | unsigned long flags; | |
910 | ||
911 | add_wait_queue(&m->pg_init_wait, &wait); | |
912 | ||
913 | while (1) { | |
914 | set_current_state(TASK_UNINTERRUPTIBLE); | |
915 | ||
916 | spin_lock_irqsave(&m->lock, flags); | |
917 | if (!m->pg_init_in_progress) { | |
918 | spin_unlock_irqrestore(&m->lock, flags); | |
919 | break; | |
920 | } | |
921 | spin_unlock_irqrestore(&m->lock, flags); | |
922 | ||
923 | io_schedule(); | |
924 | } | |
925 | set_current_state(TASK_RUNNING); | |
926 | ||
927 | remove_wait_queue(&m->pg_init_wait, &wait); | |
928 | } | |
929 | ||
930 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 931 | { |
954a73d5 SKM |
932 | unsigned long flags; |
933 | ||
934 | spin_lock_irqsave(&m->lock, flags); | |
935 | m->pg_init_disabled = 1; | |
936 | spin_unlock_irqrestore(&m->lock, flags); | |
937 | ||
bab7cfc7 | 938 | flush_workqueue(kmpath_handlerd); |
2bded7bd | 939 | multipath_wait_for_pg_init_completion(m); |
a044d016 | 940 | flush_workqueue(kmultipathd); |
43829731 | 941 | flush_work(&m->trigger_event); |
954a73d5 SKM |
942 | |
943 | spin_lock_irqsave(&m->lock, flags); | |
944 | m->pg_init_disabled = 0; | |
945 | spin_unlock_irqrestore(&m->lock, flags); | |
6df400ab KU |
946 | } |
947 | ||
948 | static void multipath_dtr(struct dm_target *ti) | |
949 | { | |
950 | struct multipath *m = ti->private; | |
951 | ||
2bded7bd | 952 | flush_multipath_work(m); |
1da177e4 LT |
953 | free_multipath(m); |
954 | } | |
955 | ||
1da177e4 LT |
956 | /* |
957 | * Take a path out of use. | |
958 | */ | |
959 | static int fail_path(struct pgpath *pgpath) | |
960 | { | |
961 | unsigned long flags; | |
962 | struct multipath *m = pgpath->pg->m; | |
963 | ||
964 | spin_lock_irqsave(&m->lock, flags); | |
965 | ||
6680073d | 966 | if (!pgpath->is_active) |
1da177e4 LT |
967 | goto out; |
968 | ||
72d94861 | 969 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
970 | |
971 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
6680073d | 972 | pgpath->is_active = 0; |
1da177e4 LT |
973 | pgpath->fail_count++; |
974 | ||
975 | m->nr_valid_paths--; | |
976 | ||
977 | if (pgpath == m->current_pgpath) | |
978 | m->current_pgpath = NULL; | |
979 | ||
b15546f9 MA |
980 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
981 | pgpath->path.dev->name, m->nr_valid_paths); | |
982 | ||
fe9cf30e | 983 | schedule_work(&m->trigger_event); |
1da177e4 LT |
984 | |
985 | out: | |
986 | spin_unlock_irqrestore(&m->lock, flags); | |
987 | ||
988 | return 0; | |
989 | } | |
990 | ||
991 | /* | |
992 | * Reinstate a previously-failed path | |
993 | */ | |
994 | static int reinstate_path(struct pgpath *pgpath) | |
995 | { | |
63d832c3 | 996 | int r = 0, run_queue = 0; |
1da177e4 LT |
997 | unsigned long flags; |
998 | struct multipath *m = pgpath->pg->m; | |
999 | ||
1000 | spin_lock_irqsave(&m->lock, flags); | |
1001 | ||
6680073d | 1002 | if (pgpath->is_active) |
1da177e4 LT |
1003 | goto out; |
1004 | ||
def052d2 | 1005 | if (!pgpath->pg->ps.type->reinstate_path) { |
1da177e4 LT |
1006 | DMWARN("Reinstate path not supported by path selector %s", |
1007 | pgpath->pg->ps.type->name); | |
1008 | r = -EINVAL; | |
1009 | goto out; | |
1010 | } | |
1011 | ||
1012 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1013 | if (r) | |
1014 | goto out; | |
1015 | ||
6680073d | 1016 | pgpath->is_active = 1; |
1da177e4 | 1017 | |
e8099177 | 1018 | if (!m->nr_valid_paths++) { |
e54f77dd | 1019 | m->current_pgpath = NULL; |
63d832c3 | 1020 | run_queue = 1; |
e54f77dd | 1021 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
4e2d19e4 | 1022 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
e54f77dd CS |
1023 | m->pg_init_in_progress++; |
1024 | } | |
1da177e4 | 1025 | |
b15546f9 MA |
1026 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
1027 | pgpath->path.dev->name, m->nr_valid_paths); | |
1028 | ||
fe9cf30e | 1029 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1030 | |
1031 | out: | |
1032 | spin_unlock_irqrestore(&m->lock, flags); | |
63d832c3 HR |
1033 | if (run_queue) |
1034 | dm_table_run_md_queue_async(m->ti->table); | |
1da177e4 LT |
1035 | |
1036 | return r; | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1041 | */ | |
1042 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1043 | action_fn action) | |
1044 | { | |
19040c0b | 1045 | int r = -EINVAL; |
1da177e4 LT |
1046 | struct pgpath *pgpath; |
1047 | struct priority_group *pg; | |
1048 | ||
1049 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1050 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1051 | if (pgpath->path.dev == dev) | |
1052 | r = action(pgpath); | |
1053 | } | |
1054 | } | |
1055 | ||
1056 | return r; | |
1057 | } | |
1058 | ||
1059 | /* | |
1060 | * Temporarily try to avoid having to use the specified PG | |
1061 | */ | |
1062 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
1063 | int bypassed) | |
1064 | { | |
1065 | unsigned long flags; | |
1066 | ||
1067 | spin_lock_irqsave(&m->lock, flags); | |
1068 | ||
1069 | pg->bypassed = bypassed; | |
1070 | m->current_pgpath = NULL; | |
1071 | m->current_pg = NULL; | |
1072 | ||
1073 | spin_unlock_irqrestore(&m->lock, flags); | |
1074 | ||
fe9cf30e | 1075 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1076 | } |
1077 | ||
1078 | /* | |
1079 | * Switch to using the specified PG from the next I/O that gets mapped | |
1080 | */ | |
1081 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1082 | { | |
1083 | struct priority_group *pg; | |
1084 | unsigned pgnum; | |
1085 | unsigned long flags; | |
31998ef1 | 1086 | char dummy; |
1da177e4 | 1087 | |
31998ef1 | 1088 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
1da177e4 LT |
1089 | (pgnum > m->nr_priority_groups)) { |
1090 | DMWARN("invalid PG number supplied to switch_pg_num"); | |
1091 | return -EINVAL; | |
1092 | } | |
1093 | ||
1094 | spin_lock_irqsave(&m->lock, flags); | |
1095 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1096 | pg->bypassed = 0; | |
1097 | if (--pgnum) | |
1098 | continue; | |
1099 | ||
1100 | m->current_pgpath = NULL; | |
1101 | m->current_pg = NULL; | |
1102 | m->next_pg = pg; | |
1103 | } | |
1104 | spin_unlock_irqrestore(&m->lock, flags); | |
1105 | ||
fe9cf30e | 1106 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1107 | return 0; |
1108 | } | |
1109 | ||
1110 | /* | |
1111 | * Set/clear bypassed status of a PG. | |
1112 | * PGs are numbered upwards from 1 in the order they were declared. | |
1113 | */ | |
1114 | static int bypass_pg_num(struct multipath *m, const char *pgstr, int bypassed) | |
1115 | { | |
1116 | struct priority_group *pg; | |
1117 | unsigned pgnum; | |
31998ef1 | 1118 | char dummy; |
1da177e4 | 1119 | |
31998ef1 | 1120 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
1da177e4 LT |
1121 | (pgnum > m->nr_priority_groups)) { |
1122 | DMWARN("invalid PG number supplied to bypass_pg"); | |
1123 | return -EINVAL; | |
1124 | } | |
1125 | ||
1126 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1127 | if (!--pgnum) | |
1128 | break; | |
1129 | } | |
1130 | ||
1131 | bypass_pg(m, pg, bypassed); | |
1132 | return 0; | |
1133 | } | |
1134 | ||
c9e45581 DW |
1135 | /* |
1136 | * Should we retry pg_init immediately? | |
1137 | */ | |
1138 | static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) | |
1139 | { | |
1140 | unsigned long flags; | |
1141 | int limit_reached = 0; | |
1142 | ||
1143 | spin_lock_irqsave(&m->lock, flags); | |
1144 | ||
954a73d5 | 1145 | if (m->pg_init_count <= m->pg_init_retries && !m->pg_init_disabled) |
c9e45581 DW |
1146 | m->pg_init_required = 1; |
1147 | else | |
1148 | limit_reached = 1; | |
1149 | ||
1150 | spin_unlock_irqrestore(&m->lock, flags); | |
1151 | ||
1152 | return limit_reached; | |
1153 | } | |
1154 | ||
3ae31f6a | 1155 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1156 | { |
83c0d5d5 | 1157 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1158 | struct priority_group *pg = pgpath->pg; |
1159 | struct multipath *m = pg->m; | |
1160 | unsigned long flags; | |
4e2d19e4 | 1161 | unsigned delay_retry = 0; |
cfae5c9b CS |
1162 | |
1163 | /* device or driver problems */ | |
1164 | switch (errors) { | |
1165 | case SCSI_DH_OK: | |
1166 | break; | |
1167 | case SCSI_DH_NOSYS: | |
1168 | if (!m->hw_handler_name) { | |
1169 | errors = 0; | |
1170 | break; | |
1171 | } | |
f7b934c8 MB |
1172 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1173 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1174 | /* |
1175 | * Fail path for now, so we do not ping pong | |
1176 | */ | |
1177 | fail_path(pgpath); | |
1178 | break; | |
1179 | case SCSI_DH_DEV_TEMP_BUSY: | |
1180 | /* | |
1181 | * Probably doing something like FW upgrade on the | |
1182 | * controller so try the other pg. | |
1183 | */ | |
1184 | bypass_pg(m, pg, 1); | |
1185 | break; | |
cfae5c9b | 1186 | case SCSI_DH_RETRY: |
4e2d19e4 CS |
1187 | /* Wait before retrying. */ |
1188 | delay_retry = 1; | |
cfae5c9b CS |
1189 | case SCSI_DH_IMM_RETRY: |
1190 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1191 | if (pg_init_limit_reached(m, pgpath)) | |
1192 | fail_path(pgpath); | |
1193 | errors = 0; | |
1194 | break; | |
1195 | default: | |
1196 | /* | |
1197 | * We probably do not want to fail the path for a device | |
1198 | * error, but this is what the old dm did. In future | |
1199 | * patches we can do more advanced handling. | |
1200 | */ | |
1201 | fail_path(pgpath); | |
1202 | } | |
1203 | ||
1204 | spin_lock_irqsave(&m->lock, flags); | |
1205 | if (errors) { | |
e54f77dd CS |
1206 | if (pgpath == m->current_pgpath) { |
1207 | DMERR("Could not failover device. Error %d.", errors); | |
1208 | m->current_pgpath = NULL; | |
1209 | m->current_pg = NULL; | |
1210 | } | |
d0259bf0 | 1211 | } else if (!m->pg_init_required) |
cfae5c9b | 1212 | pg->bypassed = 0; |
cfae5c9b | 1213 | |
d0259bf0 KU |
1214 | if (--m->pg_init_in_progress) |
1215 | /* Activations of other paths are still on going */ | |
1216 | goto out; | |
1217 | ||
3e9f1be1 HR |
1218 | if (m->pg_init_required) { |
1219 | m->pg_init_delay_retry = delay_retry; | |
1220 | if (__pg_init_all_paths(m)) | |
1221 | goto out; | |
1222 | } | |
1223 | m->queue_io = 0; | |
d0259bf0 | 1224 | |
2bded7bd KU |
1225 | /* |
1226 | * Wake up any thread waiting to suspend. | |
1227 | */ | |
1228 | wake_up(&m->pg_init_wait); | |
1229 | ||
d0259bf0 | 1230 | out: |
cfae5c9b CS |
1231 | spin_unlock_irqrestore(&m->lock, flags); |
1232 | } | |
1233 | ||
bab7cfc7 CS |
1234 | static void activate_path(struct work_struct *work) |
1235 | { | |
e54f77dd | 1236 | struct pgpath *pgpath = |
4e2d19e4 | 1237 | container_of(work, struct pgpath, activate_path.work); |
bab7cfc7 | 1238 | |
3a017509 HR |
1239 | if (pgpath->is_active) |
1240 | scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev), | |
1241 | pg_init_done, pgpath); | |
1242 | else | |
1243 | pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); | |
bab7cfc7 CS |
1244 | } |
1245 | ||
7e782af5 HR |
1246 | static int noretry_error(int error) |
1247 | { | |
1248 | switch (error) { | |
1249 | case -EOPNOTSUPP: | |
1250 | case -EREMOTEIO: | |
1251 | case -EILSEQ: | |
1252 | case -ENODATA: | |
cc9d3c38 | 1253 | case -ENOSPC: |
7e782af5 HR |
1254 | return 1; |
1255 | } | |
1256 | ||
1257 | /* Anything else could be a path failure, so should be retried */ | |
1258 | return 0; | |
1259 | } | |
1260 | ||
1da177e4 LT |
1261 | /* |
1262 | * end_io handling | |
1263 | */ | |
f40c67f0 | 1264 | static int do_end_io(struct multipath *m, struct request *clone, |
028867ac | 1265 | int error, struct dm_mpath_io *mpio) |
1da177e4 | 1266 | { |
f40c67f0 KU |
1267 | /* |
1268 | * We don't queue any clone request inside the multipath target | |
1269 | * during end I/O handling, since those clone requests don't have | |
1270 | * bio clones. If we queue them inside the multipath target, | |
1271 | * we need to make bio clones, that requires memory allocation. | |
1272 | * (See drivers/md/dm.c:end_clone_bio() about why the clone requests | |
1273 | * don't have bio clones.) | |
1274 | * Instead of queueing the clone request here, we queue the original | |
1275 | * request into dm core, which will remake a clone request and | |
1276 | * clone bios for it and resubmit it later. | |
1277 | */ | |
1278 | int r = DM_ENDIO_REQUEUE; | |
640eb3b0 | 1279 | unsigned long flags; |
1da177e4 | 1280 | |
f40c67f0 | 1281 | if (!error && !clone->errors) |
1da177e4 LT |
1282 | return 0; /* I/O complete */ |
1283 | ||
7eee4ae2 | 1284 | if (noretry_error(error)) |
959eb4e5 MS |
1285 | return error; |
1286 | ||
cfae5c9b CS |
1287 | if (mpio->pgpath) |
1288 | fail_path(mpio->pgpath); | |
1da177e4 | 1289 | |
640eb3b0 | 1290 | spin_lock_irqsave(&m->lock, flags); |
751b2a7d HR |
1291 | if (!m->nr_valid_paths) { |
1292 | if (!m->queue_if_no_path) { | |
1293 | if (!__must_push_back(m)) | |
1294 | r = -EIO; | |
1295 | } else { | |
1296 | if (error == -EBADE) | |
1297 | r = error; | |
1298 | } | |
1299 | } | |
640eb3b0 | 1300 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 1301 | |
f40c67f0 | 1302 | return r; |
1da177e4 LT |
1303 | } |
1304 | ||
f40c67f0 | 1305 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
1da177e4 LT |
1306 | int error, union map_info *map_context) |
1307 | { | |
028867ac AK |
1308 | struct multipath *m = ti->private; |
1309 | struct dm_mpath_io *mpio = map_context->ptr; | |
a71a261f | 1310 | struct pgpath *pgpath; |
1da177e4 LT |
1311 | struct path_selector *ps; |
1312 | int r; | |
1313 | ||
466891f9 JN |
1314 | BUG_ON(!mpio); |
1315 | ||
f40c67f0 | 1316 | r = do_end_io(m, clone, error, mpio); |
a71a261f | 1317 | pgpath = mpio->pgpath; |
1da177e4 LT |
1318 | if (pgpath) { |
1319 | ps = &pgpath->pg->ps; | |
1320 | if (ps->type->end_io) | |
02ab823f | 1321 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
1da177e4 | 1322 | } |
466891f9 | 1323 | clear_mapinfo(m, map_context); |
1da177e4 LT |
1324 | |
1325 | return r; | |
1326 | } | |
1327 | ||
1328 | /* | |
1329 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1330 | * the last path fails we must error any remaining I/O. |
1331 | * Note that if the freeze_bdev fails while suspending, the | |
1332 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1333 | */ |
1334 | static void multipath_presuspend(struct dm_target *ti) | |
1335 | { | |
1336 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 | 1337 | |
485ef69e | 1338 | queue_if_no_path(m, 0, 1); |
1da177e4 LT |
1339 | } |
1340 | ||
6df400ab KU |
1341 | static void multipath_postsuspend(struct dm_target *ti) |
1342 | { | |
6380f26f MA |
1343 | struct multipath *m = ti->private; |
1344 | ||
1345 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1346 | flush_multipath_work(m); |
6380f26f | 1347 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1348 | } |
1349 | ||
436d4108 AK |
1350 | /* |
1351 | * Restore the queue_if_no_path setting. | |
1352 | */ | |
1da177e4 LT |
1353 | static void multipath_resume(struct dm_target *ti) |
1354 | { | |
1355 | struct multipath *m = (struct multipath *) ti->private; | |
1356 | unsigned long flags; | |
1357 | ||
1358 | spin_lock_irqsave(&m->lock, flags); | |
436d4108 | 1359 | m->queue_if_no_path = m->saved_queue_if_no_path; |
1da177e4 LT |
1360 | spin_unlock_irqrestore(&m->lock, flags); |
1361 | } | |
1362 | ||
1363 | /* | |
1364 | * Info output has the following format: | |
1365 | * num_multipath_feature_args [multipath_feature_args]* | |
1366 | * num_handler_status_args [handler_status_args]* | |
1367 | * num_groups init_group_number | |
1368 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1369 | * num_paths num_selector_args | |
1370 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1371 | * | |
1372 | * Table output has the following format (identical to the constructor string): | |
1373 | * num_feature_args [features_args]* | |
1374 | * num_handler_args hw_handler [hw_handler_args]* | |
1375 | * num_groups init_group_number | |
1376 | * [priority selector-name num_ps_args [ps_args]* | |
1377 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1378 | */ | |
fd7c092e MP |
1379 | static void multipath_status(struct dm_target *ti, status_type_t type, |
1380 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
1381 | { |
1382 | int sz = 0; | |
1383 | unsigned long flags; | |
1384 | struct multipath *m = (struct multipath *) ti->private; | |
1da177e4 LT |
1385 | struct priority_group *pg; |
1386 | struct pgpath *p; | |
1387 | unsigned pg_num; | |
1388 | char state; | |
1389 | ||
1390 | spin_lock_irqsave(&m->lock, flags); | |
1391 | ||
1392 | /* Features */ | |
1393 | if (type == STATUSTYPE_INFO) | |
e8099177 | 1394 | DMEMIT("2 %u %u ", m->queue_io, m->pg_init_count); |
c9e45581 DW |
1395 | else { |
1396 | DMEMIT("%u ", m->queue_if_no_path + | |
4e2d19e4 | 1397 | (m->pg_init_retries > 0) * 2 + |
a58a935d MS |
1398 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
1399 | m->retain_attached_hw_handler); | |
c9e45581 DW |
1400 | if (m->queue_if_no_path) |
1401 | DMEMIT("queue_if_no_path "); | |
1402 | if (m->pg_init_retries) | |
1403 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
4e2d19e4 CS |
1404 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
1405 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); | |
a58a935d MS |
1406 | if (m->retain_attached_hw_handler) |
1407 | DMEMIT("retain_attached_hw_handler "); | |
c9e45581 | 1408 | } |
1da177e4 | 1409 | |
cfae5c9b | 1410 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1411 | DMEMIT("0 "); |
1412 | else | |
cfae5c9b | 1413 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1414 | |
1415 | DMEMIT("%u ", m->nr_priority_groups); | |
1416 | ||
1417 | if (m->next_pg) | |
1418 | pg_num = m->next_pg->pg_num; | |
1419 | else if (m->current_pg) | |
1420 | pg_num = m->current_pg->pg_num; | |
1421 | else | |
a490a07a | 1422 | pg_num = (m->nr_priority_groups ? 1 : 0); |
1da177e4 LT |
1423 | |
1424 | DMEMIT("%u ", pg_num); | |
1425 | ||
1426 | switch (type) { | |
1427 | case STATUSTYPE_INFO: | |
1428 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1429 | if (pg->bypassed) | |
1430 | state = 'D'; /* Disabled */ | |
1431 | else if (pg == m->current_pg) | |
1432 | state = 'A'; /* Currently Active */ | |
1433 | else | |
1434 | state = 'E'; /* Enabled */ | |
1435 | ||
1436 | DMEMIT("%c ", state); | |
1437 | ||
1438 | if (pg->ps.type->status) | |
1439 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1440 | result + sz, | |
1441 | maxlen - sz); | |
1442 | else | |
1443 | DMEMIT("0 "); | |
1444 | ||
1445 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1446 | pg->ps.type->info_args); | |
1447 | ||
1448 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1449 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1450 | p->is_active ? "A" : "F", |
1da177e4 LT |
1451 | p->fail_count); |
1452 | if (pg->ps.type->status) | |
1453 | sz += pg->ps.type->status(&pg->ps, | |
1454 | &p->path, type, result + sz, | |
1455 | maxlen - sz); | |
1456 | } | |
1457 | } | |
1458 | break; | |
1459 | ||
1460 | case STATUSTYPE_TABLE: | |
1461 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1462 | DMEMIT("%s ", pg->ps.type->name); | |
1463 | ||
1464 | if (pg->ps.type->status) | |
1465 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1466 | result + sz, | |
1467 | maxlen - sz); | |
1468 | else | |
1469 | DMEMIT("0 "); | |
1470 | ||
1471 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1472 | pg->ps.type->table_args); | |
1473 | ||
1474 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1475 | DMEMIT("%s ", p->path.dev->name); | |
1476 | if (pg->ps.type->status) | |
1477 | sz += pg->ps.type->status(&pg->ps, | |
1478 | &p->path, type, result + sz, | |
1479 | maxlen - sz); | |
1480 | } | |
1481 | } | |
1482 | break; | |
1483 | } | |
1484 | ||
1485 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
1486 | } |
1487 | ||
1488 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1489 | { | |
6380f26f | 1490 | int r = -EINVAL; |
1da177e4 LT |
1491 | struct dm_dev *dev; |
1492 | struct multipath *m = (struct multipath *) ti->private; | |
1493 | action_fn action; | |
1494 | ||
6380f26f MA |
1495 | mutex_lock(&m->work_mutex); |
1496 | ||
c2f3d24b KU |
1497 | if (dm_suspended(ti)) { |
1498 | r = -EBUSY; | |
1499 | goto out; | |
1500 | } | |
1501 | ||
1da177e4 | 1502 | if (argc == 1) { |
498f0103 | 1503 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
6380f26f MA |
1504 | r = queue_if_no_path(m, 1, 0); |
1505 | goto out; | |
498f0103 | 1506 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
6380f26f MA |
1507 | r = queue_if_no_path(m, 0, 0); |
1508 | goto out; | |
1509 | } | |
1da177e4 LT |
1510 | } |
1511 | ||
6380f26f | 1512 | if (argc != 2) { |
a356e426 | 1513 | DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); |
6380f26f MA |
1514 | goto out; |
1515 | } | |
1da177e4 | 1516 | |
498f0103 | 1517 | if (!strcasecmp(argv[0], "disable_group")) { |
6380f26f MA |
1518 | r = bypass_pg_num(m, argv[1], 1); |
1519 | goto out; | |
498f0103 | 1520 | } else if (!strcasecmp(argv[0], "enable_group")) { |
6380f26f MA |
1521 | r = bypass_pg_num(m, argv[1], 0); |
1522 | goto out; | |
498f0103 | 1523 | } else if (!strcasecmp(argv[0], "switch_group")) { |
6380f26f MA |
1524 | r = switch_pg_num(m, argv[1]); |
1525 | goto out; | |
498f0103 | 1526 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
1da177e4 | 1527 | action = reinstate_path; |
498f0103 | 1528 | else if (!strcasecmp(argv[0], "fail_path")) |
1da177e4 | 1529 | action = fail_path; |
6380f26f | 1530 | else { |
a356e426 | 1531 | DMWARN("Unrecognised multipath message received: %s", argv[0]); |
6380f26f MA |
1532 | goto out; |
1533 | } | |
1da177e4 | 1534 | |
8215d6ec | 1535 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 1536 | if (r) { |
72d94861 | 1537 | DMWARN("message: error getting device %s", |
1da177e4 | 1538 | argv[1]); |
6380f26f | 1539 | goto out; |
1da177e4 LT |
1540 | } |
1541 | ||
1542 | r = action_dev(m, dev, action); | |
1543 | ||
1544 | dm_put_device(ti, dev); | |
1545 | ||
6380f26f MA |
1546 | out: |
1547 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 1548 | return r; |
1da177e4 LT |
1549 | } |
1550 | ||
647b3d00 | 1551 | static int multipath_ioctl(struct dm_target *ti, unsigned int cmd, |
9af4aa30 MB |
1552 | unsigned long arg) |
1553 | { | |
35991652 | 1554 | struct multipath *m = ti->private; |
7ba10aa6 | 1555 | struct pgpath *pgpath; |
35991652 MP |
1556 | struct block_device *bdev; |
1557 | fmode_t mode; | |
9af4aa30 | 1558 | unsigned long flags; |
35991652 MP |
1559 | int r; |
1560 | ||
35991652 MP |
1561 | bdev = NULL; |
1562 | mode = 0; | |
1563 | r = 0; | |
9af4aa30 MB |
1564 | |
1565 | spin_lock_irqsave(&m->lock, flags); | |
1566 | ||
1567 | if (!m->current_pgpath) | |
02ab823f | 1568 | __choose_pgpath(m, 0); |
9af4aa30 | 1569 | |
7ba10aa6 MS |
1570 | pgpath = m->current_pgpath; |
1571 | ||
1572 | if (pgpath) { | |
1573 | bdev = pgpath->path.dev->bdev; | |
1574 | mode = pgpath->path.dev->mode; | |
e90dae1f | 1575 | } |
9af4aa30 | 1576 | |
7ba10aa6 | 1577 | if ((pgpath && m->queue_io) || (!pgpath && m->queue_if_no_path)) |
6c182cd8 | 1578 | r = -ENOTCONN; |
9af4aa30 MB |
1579 | else if (!bdev) |
1580 | r = -EIO; | |
1581 | ||
1582 | spin_unlock_irqrestore(&m->lock, flags); | |
1583 | ||
ec8013be PB |
1584 | /* |
1585 | * Only pass ioctls through if the device sizes match exactly. | |
1586 | */ | |
a1989b33 HR |
1587 | if (!bdev || ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT) { |
1588 | int err = scsi_verify_blk_ioctl(NULL, cmd); | |
1589 | if (err) | |
1590 | r = err; | |
1591 | } | |
ec8013be | 1592 | |
3e9f1be1 HR |
1593 | if (r == -ENOTCONN && !fatal_signal_pending(current)) { |
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 | |
633a08b8 | 1605 | return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg); |
9af4aa30 MB |
1606 | } |
1607 | ||
af4874e0 MS |
1608 | static int multipath_iterate_devices(struct dm_target *ti, |
1609 | iterate_devices_callout_fn fn, void *data) | |
1610 | { | |
1611 | struct multipath *m = ti->private; | |
1612 | struct priority_group *pg; | |
1613 | struct pgpath *p; | |
1614 | int ret = 0; | |
1615 | ||
1616 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1617 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 1618 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
1619 | if (ret) |
1620 | goto out; | |
1621 | } | |
1622 | } | |
1623 | ||
1624 | out: | |
1625 | return ret; | |
1626 | } | |
1627 | ||
f40c67f0 KU |
1628 | static int __pgpath_busy(struct pgpath *pgpath) |
1629 | { | |
1630 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
1631 | ||
52b09914 | 1632 | return blk_lld_busy(q); |
f40c67f0 KU |
1633 | } |
1634 | ||
1635 | /* | |
1636 | * We return "busy", only when we can map I/Os but underlying devices | |
1637 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
1638 | * the underlying queue). | |
1639 | * In other words, if we want to kill I/Os or queue them inside us | |
1640 | * due to map unavailability, we don't return "busy". Otherwise, | |
1641 | * dm core won't give us the I/Os and we can't do what we want. | |
1642 | */ | |
1643 | static int multipath_busy(struct dm_target *ti) | |
1644 | { | |
1645 | int busy = 0, has_active = 0; | |
1646 | struct multipath *m = ti->private; | |
1647 | struct priority_group *pg; | |
1648 | struct pgpath *pgpath; | |
1649 | unsigned long flags; | |
1650 | ||
1651 | spin_lock_irqsave(&m->lock, flags); | |
1652 | ||
7a7a3b45 JN |
1653 | /* pg_init in progress or no paths available */ |
1654 | if (m->pg_init_in_progress || | |
1655 | (!m->nr_valid_paths && m->queue_if_no_path)) { | |
b63349a7 HR |
1656 | busy = 1; |
1657 | goto out; | |
1658 | } | |
f40c67f0 KU |
1659 | /* Guess which priority_group will be used at next mapping time */ |
1660 | if (unlikely(!m->current_pgpath && m->next_pg)) | |
1661 | pg = m->next_pg; | |
1662 | else if (likely(m->current_pg)) | |
1663 | pg = m->current_pg; | |
1664 | else | |
1665 | /* | |
1666 | * We don't know which pg will be used at next mapping time. | |
1667 | * We don't call __choose_pgpath() here to avoid to trigger | |
1668 | * pg_init just by busy checking. | |
1669 | * So we don't know whether underlying devices we will be using | |
1670 | * at next mapping time are busy or not. Just try mapping. | |
1671 | */ | |
1672 | goto out; | |
1673 | ||
1674 | /* | |
1675 | * If there is one non-busy active path at least, the path selector | |
1676 | * will be able to select it. So we consider such a pg as not busy. | |
1677 | */ | |
1678 | busy = 1; | |
1679 | list_for_each_entry(pgpath, &pg->pgpaths, list) | |
1680 | if (pgpath->is_active) { | |
1681 | has_active = 1; | |
1682 | ||
1683 | if (!__pgpath_busy(pgpath)) { | |
1684 | busy = 0; | |
1685 | break; | |
1686 | } | |
1687 | } | |
1688 | ||
1689 | if (!has_active) | |
1690 | /* | |
1691 | * No active path in this pg, so this pg won't be used and | |
1692 | * the current_pg will be changed at next mapping time. | |
1693 | * We need to try mapping to determine it. | |
1694 | */ | |
1695 | busy = 0; | |
1696 | ||
1697 | out: | |
1698 | spin_unlock_irqrestore(&m->lock, flags); | |
1699 | ||
1700 | return busy; | |
1701 | } | |
1702 | ||
1da177e4 LT |
1703 | /*----------------------------------------------------------------- |
1704 | * Module setup | |
1705 | *---------------------------------------------------------------*/ | |
1706 | static struct target_type multipath_target = { | |
1707 | .name = "multipath", | |
bfebd1cd | 1708 | .version = {1, 9, 0}, |
1da177e4 LT |
1709 | .module = THIS_MODULE, |
1710 | .ctr = multipath_ctr, | |
1711 | .dtr = multipath_dtr, | |
f40c67f0 | 1712 | .map_rq = multipath_map, |
e5863d9a MS |
1713 | .clone_and_map_rq = multipath_clone_and_map, |
1714 | .release_clone_rq = multipath_release_clone, | |
f40c67f0 | 1715 | .rq_end_io = multipath_end_io, |
1da177e4 | 1716 | .presuspend = multipath_presuspend, |
6df400ab | 1717 | .postsuspend = multipath_postsuspend, |
1da177e4 LT |
1718 | .resume = multipath_resume, |
1719 | .status = multipath_status, | |
1720 | .message = multipath_message, | |
9af4aa30 | 1721 | .ioctl = multipath_ioctl, |
af4874e0 | 1722 | .iterate_devices = multipath_iterate_devices, |
f40c67f0 | 1723 | .busy = multipath_busy, |
1da177e4 LT |
1724 | }; |
1725 | ||
1726 | static int __init dm_multipath_init(void) | |
1727 | { | |
1728 | int r; | |
1729 | ||
1730 | /* allocate a slab for the dm_ios */ | |
028867ac | 1731 | _mpio_cache = KMEM_CACHE(dm_mpath_io, 0); |
1da177e4 LT |
1732 | if (!_mpio_cache) |
1733 | return -ENOMEM; | |
1734 | ||
1735 | r = dm_register_target(&multipath_target); | |
1736 | if (r < 0) { | |
0cd33124 | 1737 | DMERR("register failed %d", r); |
ff658e9c JT |
1738 | r = -EINVAL; |
1739 | goto bad_register_target; | |
1da177e4 LT |
1740 | } |
1741 | ||
4d4d66ab | 1742 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
c557308e | 1743 | if (!kmultipathd) { |
0cd33124 | 1744 | DMERR("failed to create workqueue kmpathd"); |
ff658e9c JT |
1745 | r = -ENOMEM; |
1746 | goto bad_alloc_kmultipathd; | |
c557308e AK |
1747 | } |
1748 | ||
bab7cfc7 CS |
1749 | /* |
1750 | * A separate workqueue is used to handle the device handlers | |
1751 | * to avoid overloading existing workqueue. Overloading the | |
1752 | * old workqueue would also create a bottleneck in the | |
1753 | * path of the storage hardware device activation. | |
1754 | */ | |
4d4d66ab TH |
1755 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
1756 | WQ_MEM_RECLAIM); | |
bab7cfc7 CS |
1757 | if (!kmpath_handlerd) { |
1758 | DMERR("failed to create workqueue kmpath_handlerd"); | |
ff658e9c JT |
1759 | r = -ENOMEM; |
1760 | goto bad_alloc_kmpath_handlerd; | |
bab7cfc7 CS |
1761 | } |
1762 | ||
72d94861 | 1763 | DMINFO("version %u.%u.%u loaded", |
1da177e4 LT |
1764 | multipath_target.version[0], multipath_target.version[1], |
1765 | multipath_target.version[2]); | |
1766 | ||
ff658e9c JT |
1767 | return 0; |
1768 | ||
1769 | bad_alloc_kmpath_handlerd: | |
1770 | destroy_workqueue(kmultipathd); | |
1771 | bad_alloc_kmultipathd: | |
1772 | dm_unregister_target(&multipath_target); | |
1773 | bad_register_target: | |
1774 | kmem_cache_destroy(_mpio_cache); | |
1775 | ||
1da177e4 LT |
1776 | return r; |
1777 | } | |
1778 | ||
1779 | static void __exit dm_multipath_exit(void) | |
1780 | { | |
bab7cfc7 | 1781 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
1782 | destroy_workqueue(kmultipathd); |
1783 | ||
10d3bd09 | 1784 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
1785 | kmem_cache_destroy(_mpio_cache); |
1786 | } | |
1787 | ||
1da177e4 LT |
1788 | module_init(dm_multipath_init); |
1789 | module_exit(dm_multipath_exit); | |
1790 | ||
1791 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
1792 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
1793 | MODULE_LICENSE("GPL"); |