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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 | ||
4cc96131 | 10 | #include "dm-rq.h" |
76e33fe4 | 11 | #include "dm-bio-record.h" |
1da177e4 | 12 | #include "dm-path-selector.h" |
b15546f9 | 13 | #include "dm-uevent.h" |
1da177e4 | 14 | |
e5863d9a | 15 | #include <linux/blkdev.h> |
1da177e4 LT |
16 | #include <linux/ctype.h> |
17 | #include <linux/init.h> | |
18 | #include <linux/mempool.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/time.h> | |
23 | #include <linux/workqueue.h> | |
35991652 | 24 | #include <linux/delay.h> |
cfae5c9b | 25 | #include <scsi/scsi_dh.h> |
60063497 | 26 | #include <linux/atomic.h> |
78ce23b5 | 27 | #include <linux/blk-mq.h> |
1da177e4 | 28 | |
72d94861 | 29 | #define DM_MSG_PREFIX "multipath" |
4e2d19e4 CS |
30 | #define DM_PG_INIT_DELAY_MSECS 2000 |
31 | #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) | |
1da177e4 LT |
32 | |
33 | /* Path properties */ | |
34 | struct pgpath { | |
35 | struct list_head list; | |
36 | ||
37 | struct priority_group *pg; /* Owning PG */ | |
38 | unsigned fail_count; /* Cumulative failure count */ | |
39 | ||
c922d5f7 | 40 | struct dm_path path; |
4e2d19e4 | 41 | struct delayed_work activate_path; |
be7d31cc MS |
42 | |
43 | bool is_active:1; /* Path status */ | |
1da177e4 LT |
44 | }; |
45 | ||
46 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
47 | ||
48 | /* | |
49 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
50 | * Each has a path selector which controls which path gets used. | |
51 | */ | |
52 | struct priority_group { | |
53 | struct list_head list; | |
54 | ||
55 | struct multipath *m; /* Owning multipath instance */ | |
56 | struct path_selector ps; | |
57 | ||
58 | unsigned pg_num; /* Reference number */ | |
1da177e4 LT |
59 | unsigned nr_pgpaths; /* Number of paths in PG */ |
60 | struct list_head pgpaths; | |
be7d31cc MS |
61 | |
62 | bool bypassed:1; /* Temporarily bypass this PG? */ | |
1da177e4 LT |
63 | }; |
64 | ||
65 | /* Multipath context */ | |
66 | struct multipath { | |
67 | struct list_head list; | |
68 | struct dm_target *ti; | |
69 | ||
cfae5c9b | 70 | const char *hw_handler_name; |
2bfd2e13 | 71 | char *hw_handler_params; |
4e2d19e4 | 72 | |
1fbdd2b3 MS |
73 | spinlock_t lock; |
74 | ||
1da177e4 LT |
75 | unsigned nr_priority_groups; |
76 | struct list_head priority_groups; | |
4e2d19e4 CS |
77 | |
78 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ | |
79 | ||
1da177e4 LT |
80 | struct pgpath *current_pgpath; |
81 | struct priority_group *current_pg; | |
82 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
1da177e4 | 83 | |
518257b1 | 84 | unsigned long flags; /* Multipath state flags */ |
1fbdd2b3 | 85 | |
c9e45581 | 86 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
4e2d19e4 | 87 | unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ |
1da177e4 | 88 | |
91e968aa MS |
89 | atomic_t nr_valid_paths; /* Total number of usable paths */ |
90 | atomic_t pg_init_in_progress; /* Only one pg_init allowed at once */ | |
91 | atomic_t pg_init_count; /* Number of times pg_init called */ | |
92 | ||
7e0d574f | 93 | enum dm_queue_mode queue_mode; |
e83068a5 | 94 | |
6380f26f | 95 | struct mutex work_mutex; |
20800cb3 | 96 | struct work_struct trigger_event; |
76e33fe4 MS |
97 | |
98 | struct work_struct process_queued_bios; | |
99 | struct bio_list queued_bios; | |
1da177e4 LT |
100 | }; |
101 | ||
102 | /* | |
76e33fe4 | 103 | * Context information attached to each io we process. |
1da177e4 | 104 | */ |
028867ac | 105 | struct dm_mpath_io { |
1da177e4 | 106 | struct pgpath *pgpath; |
02ab823f | 107 | size_t nr_bytes; |
1da177e4 LT |
108 | }; |
109 | ||
110 | typedef int (*action_fn) (struct pgpath *pgpath); | |
111 | ||
bab7cfc7 | 112 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 | 113 | static void trigger_event(struct work_struct *work); |
89bfce76 BVA |
114 | static void activate_or_offline_path(struct pgpath *pgpath); |
115 | static void activate_path_work(struct work_struct *work); | |
76e33fe4 | 116 | static void process_queued_bios(struct work_struct *work); |
1da177e4 | 117 | |
518257b1 MS |
118 | /*----------------------------------------------- |
119 | * Multipath state flags. | |
120 | *-----------------------------------------------*/ | |
121 | ||
122 | #define MPATHF_QUEUE_IO 0 /* Must we queue all I/O? */ | |
123 | #define MPATHF_QUEUE_IF_NO_PATH 1 /* Queue I/O if last path fails? */ | |
124 | #define MPATHF_SAVED_QUEUE_IF_NO_PATH 2 /* Saved state during suspension */ | |
125 | #define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3 /* If there's already a hw_handler present, don't change it. */ | |
126 | #define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */ | |
127 | #define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */ | |
128 | #define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */ | |
1da177e4 LT |
129 | |
130 | /*----------------------------------------------- | |
131 | * Allocation routines | |
132 | *-----------------------------------------------*/ | |
133 | ||
134 | static struct pgpath *alloc_pgpath(void) | |
135 | { | |
e69fae56 | 136 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 137 | |
224cb3e9 | 138 | if (pgpath) { |
be7d31cc | 139 | pgpath->is_active = true; |
89bfce76 | 140 | INIT_DELAYED_WORK(&pgpath->activate_path, activate_path_work); |
224cb3e9 | 141 | } |
1da177e4 LT |
142 | |
143 | return pgpath; | |
144 | } | |
145 | ||
028867ac | 146 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
147 | { |
148 | kfree(pgpath); | |
149 | } | |
150 | ||
151 | static struct priority_group *alloc_priority_group(void) | |
152 | { | |
153 | struct priority_group *pg; | |
154 | ||
e69fae56 | 155 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 156 | |
e69fae56 MM |
157 | if (pg) |
158 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
159 | |
160 | return pg; | |
161 | } | |
162 | ||
163 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
164 | { | |
165 | struct pgpath *pgpath, *tmp; | |
166 | ||
167 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
168 | list_del(&pgpath->list); | |
169 | dm_put_device(ti, pgpath->path.dev); | |
170 | free_pgpath(pgpath); | |
171 | } | |
172 | } | |
173 | ||
174 | static void free_priority_group(struct priority_group *pg, | |
175 | struct dm_target *ti) | |
176 | { | |
177 | struct path_selector *ps = &pg->ps; | |
178 | ||
179 | if (ps->type) { | |
180 | ps->type->destroy(ps); | |
181 | dm_put_path_selector(ps->type); | |
182 | } | |
183 | ||
184 | free_pgpaths(&pg->pgpaths, ti); | |
185 | kfree(pg); | |
186 | } | |
187 | ||
e83068a5 | 188 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
189 | { |
190 | struct multipath *m; | |
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); | |
518257b1 | 196 | set_bit(MPATHF_QUEUE_IO, &m->flags); |
91e968aa MS |
197 | atomic_set(&m->nr_valid_paths, 0); |
198 | atomic_set(&m->pg_init_in_progress, 0); | |
199 | atomic_set(&m->pg_init_count, 0); | |
4e2d19e4 | 200 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; |
c4028958 | 201 | INIT_WORK(&m->trigger_event, trigger_event); |
2bded7bd | 202 | init_waitqueue_head(&m->pg_init_wait); |
6380f26f | 203 | mutex_init(&m->work_mutex); |
8637a6bf | 204 | |
e83068a5 | 205 | m->queue_mode = DM_TYPE_NONE; |
76e33fe4 | 206 | |
28f16c20 MM |
207 | m->ti = ti; |
208 | ti->private = m; | |
1da177e4 LT |
209 | } |
210 | ||
211 | return m; | |
212 | } | |
213 | ||
e83068a5 MS |
214 | static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m) |
215 | { | |
216 | if (m->queue_mode == DM_TYPE_NONE) { | |
217 | /* | |
218 | * Default to request-based. | |
219 | */ | |
220 | if (dm_use_blk_mq(dm_table_get_md(ti->table))) | |
221 | m->queue_mode = DM_TYPE_MQ_REQUEST_BASED; | |
222 | else | |
223 | m->queue_mode = DM_TYPE_REQUEST_BASED; | |
eb8db831 | 224 | } else if (m->queue_mode == DM_TYPE_BIO_BASED) { |
e83068a5 MS |
225 | INIT_WORK(&m->process_queued_bios, process_queued_bios); |
226 | /* | |
227 | * bio-based doesn't support any direct scsi_dh management; | |
228 | * it just discovers if a scsi_dh is attached. | |
229 | */ | |
230 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); | |
231 | } | |
232 | ||
233 | dm_table_set_type(ti->table, m->queue_mode); | |
234 | ||
235 | return 0; | |
236 | } | |
237 | ||
1da177e4 LT |
238 | static void free_multipath(struct multipath *m) |
239 | { | |
240 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
241 | |
242 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
243 | list_del(&pg->list); | |
244 | free_priority_group(pg, m->ti); | |
245 | } | |
246 | ||
cfae5c9b | 247 | kfree(m->hw_handler_name); |
2bfd2e13 | 248 | kfree(m->hw_handler_params); |
1da177e4 LT |
249 | kfree(m); |
250 | } | |
251 | ||
2eff1924 MS |
252 | static struct dm_mpath_io *get_mpio(union map_info *info) |
253 | { | |
254 | return info->ptr; | |
255 | } | |
256 | ||
bf661be1 MS |
257 | static size_t multipath_per_bio_data_size(void) |
258 | { | |
259 | return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details); | |
260 | } | |
261 | ||
76e33fe4 MS |
262 | static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio) |
263 | { | |
bf661be1 | 264 | return dm_per_bio_data(bio, multipath_per_bio_data_size()); |
76e33fe4 MS |
265 | } |
266 | ||
bf661be1 | 267 | static struct dm_bio_details *get_bio_details_from_bio(struct bio *bio) |
76e33fe4 | 268 | { |
bf661be1 | 269 | /* dm_bio_details is immediately after the dm_mpath_io in bio's per-bio-data */ |
76e33fe4 | 270 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); |
bf661be1 MS |
271 | void *bio_details = mpio + 1; |
272 | ||
273 | return bio_details; | |
274 | } | |
275 | ||
276 | static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p, | |
277 | struct dm_bio_details **bio_details_p) | |
278 | { | |
279 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); | |
280 | struct dm_bio_details *bio_details = get_bio_details_from_bio(bio); | |
76e33fe4 MS |
281 | |
282 | memset(mpio, 0, sizeof(*mpio)); | |
bf661be1 MS |
283 | memset(bio_details, 0, sizeof(*bio_details)); |
284 | dm_bio_record(bio_details, bio); | |
76e33fe4 | 285 | |
bf661be1 MS |
286 | if (mpio_p) |
287 | *mpio_p = mpio; | |
288 | if (bio_details_p) | |
289 | *bio_details_p = bio_details; | |
76e33fe4 MS |
290 | } |
291 | ||
1da177e4 LT |
292 | /*----------------------------------------------- |
293 | * Path selection | |
294 | *-----------------------------------------------*/ | |
295 | ||
3e9f1be1 | 296 | static int __pg_init_all_paths(struct multipath *m) |
fb612642 KU |
297 | { |
298 | struct pgpath *pgpath; | |
4e2d19e4 | 299 | unsigned long pg_init_delay = 0; |
fb612642 | 300 | |
b194679f BVA |
301 | lockdep_assert_held(&m->lock); |
302 | ||
91e968aa | 303 | if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) |
3e9f1be1 | 304 | return 0; |
17f4ff45 | 305 | |
91e968aa | 306 | atomic_inc(&m->pg_init_count); |
518257b1 | 307 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
3e9f1be1 HR |
308 | |
309 | /* Check here to reset pg_init_required */ | |
310 | if (!m->current_pg) | |
311 | return 0; | |
312 | ||
518257b1 | 313 | if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags)) |
4e2d19e4 CS |
314 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? |
315 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); | |
fb612642 KU |
316 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
317 | /* Skip failed paths */ | |
318 | if (!pgpath->is_active) | |
319 | continue; | |
4e2d19e4 CS |
320 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
321 | pg_init_delay)) | |
91e968aa | 322 | atomic_inc(&m->pg_init_in_progress); |
fb612642 | 323 | } |
91e968aa | 324 | return atomic_read(&m->pg_init_in_progress); |
fb612642 KU |
325 | } |
326 | ||
c1d7ecf7 | 327 | static int pg_init_all_paths(struct multipath *m) |
1da177e4 | 328 | { |
c1d7ecf7 | 329 | int ret; |
2da1610a MS |
330 | unsigned long flags; |
331 | ||
332 | spin_lock_irqsave(&m->lock, flags); | |
c1d7ecf7 | 333 | ret = __pg_init_all_paths(m); |
2da1610a | 334 | spin_unlock_irqrestore(&m->lock, flags); |
c1d7ecf7 BVA |
335 | |
336 | return ret; | |
2da1610a MS |
337 | } |
338 | ||
339 | static void __switch_pg(struct multipath *m, struct priority_group *pg) | |
340 | { | |
341 | m->current_pg = pg; | |
1da177e4 LT |
342 | |
343 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 344 | if (m->hw_handler_name) { |
518257b1 MS |
345 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
346 | set_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 347 | } else { |
518257b1 MS |
348 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
349 | clear_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 350 | } |
c9e45581 | 351 | |
91e968aa | 352 | atomic_set(&m->pg_init_count, 0); |
1da177e4 LT |
353 | } |
354 | ||
2da1610a MS |
355 | static struct pgpath *choose_path_in_pg(struct multipath *m, |
356 | struct priority_group *pg, | |
357 | size_t nr_bytes) | |
1da177e4 | 358 | { |
2da1610a | 359 | unsigned long flags; |
c922d5f7 | 360 | struct dm_path *path; |
2da1610a | 361 | struct pgpath *pgpath; |
1da177e4 | 362 | |
90a4323c | 363 | path = pg->ps.type->select_path(&pg->ps, nr_bytes); |
1da177e4 | 364 | if (!path) |
2da1610a | 365 | return ERR_PTR(-ENXIO); |
1da177e4 | 366 | |
2da1610a | 367 | pgpath = path_to_pgpath(path); |
1da177e4 | 368 | |
506458ef | 369 | if (unlikely(READ_ONCE(m->current_pg) != pg)) { |
2da1610a MS |
370 | /* Only update current_pgpath if pg changed */ |
371 | spin_lock_irqsave(&m->lock, flags); | |
372 | m->current_pgpath = pgpath; | |
373 | __switch_pg(m, pg); | |
374 | spin_unlock_irqrestore(&m->lock, flags); | |
375 | } | |
1da177e4 | 376 | |
2da1610a | 377 | return pgpath; |
1da177e4 LT |
378 | } |
379 | ||
2da1610a | 380 | static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 | 381 | { |
2da1610a | 382 | unsigned long flags; |
1da177e4 | 383 | struct priority_group *pg; |
2da1610a | 384 | struct pgpath *pgpath; |
d19a55cc | 385 | unsigned bypassed = 1; |
1da177e4 | 386 | |
91e968aa | 387 | if (!atomic_read(&m->nr_valid_paths)) { |
518257b1 | 388 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
1da177e4 | 389 | goto failed; |
1f271972 | 390 | } |
1da177e4 LT |
391 | |
392 | /* Were we instructed to switch PG? */ | |
506458ef | 393 | if (READ_ONCE(m->next_pg)) { |
2da1610a | 394 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 395 | pg = m->next_pg; |
2da1610a MS |
396 | if (!pg) { |
397 | spin_unlock_irqrestore(&m->lock, flags); | |
398 | goto check_current_pg; | |
399 | } | |
1da177e4 | 400 | m->next_pg = NULL; |
2da1610a MS |
401 | spin_unlock_irqrestore(&m->lock, flags); |
402 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
403 | if (!IS_ERR_OR_NULL(pgpath)) | |
404 | return pgpath; | |
1da177e4 LT |
405 | } |
406 | ||
407 | /* Don't change PG until it has no remaining paths */ | |
2da1610a | 408 | check_current_pg: |
506458ef | 409 | pg = READ_ONCE(m->current_pg); |
2da1610a MS |
410 | if (pg) { |
411 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
412 | if (!IS_ERR_OR_NULL(pgpath)) | |
413 | return pgpath; | |
414 | } | |
1da177e4 LT |
415 | |
416 | /* | |
417 | * Loop through priority groups until we find a valid path. | |
418 | * First time we skip PGs marked 'bypassed'. | |
f220fd4e MC |
419 | * Second time we only try the ones we skipped, but set |
420 | * pg_init_delay_retry so we do not hammer controllers. | |
1da177e4 LT |
421 | */ |
422 | do { | |
423 | list_for_each_entry(pg, &m->priority_groups, list) { | |
d19a55cc | 424 | if (pg->bypassed == !!bypassed) |
1da177e4 | 425 | continue; |
2da1610a MS |
426 | pgpath = choose_path_in_pg(m, pg, nr_bytes); |
427 | if (!IS_ERR_OR_NULL(pgpath)) { | |
f220fd4e | 428 | if (!bypassed) |
518257b1 | 429 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); |
2da1610a | 430 | return pgpath; |
f220fd4e | 431 | } |
1da177e4 LT |
432 | } |
433 | } while (bypassed--); | |
434 | ||
435 | failed: | |
2da1610a | 436 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
437 | m->current_pgpath = NULL; |
438 | m->current_pg = NULL; | |
2da1610a MS |
439 | spin_unlock_irqrestore(&m->lock, flags); |
440 | ||
441 | return NULL; | |
1da177e4 LT |
442 | } |
443 | ||
45e15720 | 444 | /* |
86331f39 BVA |
445 | * dm_report_EIO() is a macro instead of a function to make pr_debug() |
446 | * report the function name and line number of the function from which | |
447 | * it has been invoked. | |
45e15720 | 448 | */ |
86331f39 | 449 | #define dm_report_EIO(m) \ |
18a482f5 | 450 | do { \ |
86331f39 BVA |
451 | struct mapped_device *md = dm_table_get_md((m)->ti->table); \ |
452 | \ | |
453 | pr_debug("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d\n", \ | |
454 | dm_device_name(md), \ | |
455 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags), \ | |
456 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \ | |
457 | dm_noflush_suspending((m)->ti)); \ | |
18a482f5 | 458 | } while (0) |
45e15720 | 459 | |
c1fd0abe MS |
460 | /* |
461 | * Check whether bios must be queued in the device-mapper core rather | |
462 | * than here in the target. | |
463 | * | |
464 | * If MPATHF_QUEUE_IF_NO_PATH and MPATHF_SAVED_QUEUE_IF_NO_PATH hold | |
465 | * the same value then we are not between multipath_presuspend() | |
466 | * and multipath_resume() calls and we have no need to check | |
467 | * for the DMF_NOFLUSH_SUSPENDING flag. | |
468 | */ | |
469 | static bool __must_push_back(struct multipath *m, unsigned long flags) | |
470 | { | |
471 | return ((test_bit(MPATHF_QUEUE_IF_NO_PATH, &flags) != | |
472 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &flags)) && | |
473 | dm_noflush_suspending(m->ti)); | |
474 | } | |
475 | ||
476 | /* | |
477 | * Following functions use READ_ONCE to get atomic access to | |
478 | * all m->flags to avoid taking spinlock | |
479 | */ | |
480 | static bool must_push_back_rq(struct multipath *m) | |
481 | { | |
482 | unsigned long flags = READ_ONCE(m->flags); | |
483 | return test_bit(MPATHF_QUEUE_IF_NO_PATH, &flags) || __must_push_back(m, flags); | |
484 | } | |
485 | ||
486 | static bool must_push_back_bio(struct multipath *m) | |
487 | { | |
488 | unsigned long flags = READ_ONCE(m->flags); | |
489 | return __must_push_back(m, flags); | |
490 | } | |
491 | ||
36fcffcc | 492 | /* |
76e33fe4 | 493 | * Map cloned requests (request-based multipath) |
36fcffcc | 494 | */ |
eb8db831 CH |
495 | static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, |
496 | union map_info *map_context, | |
497 | struct request **__clone) | |
1da177e4 | 498 | { |
7943bd6d | 499 | struct multipath *m = ti->private; |
eb8db831 | 500 | size_t nr_bytes = blk_rq_bytes(rq); |
1da177e4 | 501 | struct pgpath *pgpath; |
f40c67f0 | 502 | struct block_device *bdev; |
eb8db831 | 503 | struct dm_mpath_io *mpio = get_mpio(map_context); |
7083abbb | 504 | struct request_queue *q; |
eb8db831 | 505 | struct request *clone; |
1da177e4 | 506 | |
1da177e4 | 507 | /* Do we need to select a new pgpath? */ |
506458ef | 508 | pgpath = READ_ONCE(m->current_pgpath); |
2da1610a MS |
509 | if (!pgpath || !test_bit(MPATHF_QUEUE_IO, &m->flags)) |
510 | pgpath = choose_pgpath(m, nr_bytes); | |
1da177e4 | 511 | |
9bf59a61 | 512 | if (!pgpath) { |
c1fd0abe | 513 | if (must_push_back_rq(m)) |
b88efd43 | 514 | return DM_MAPIO_DELAY_REQUEUE; |
18a482f5 | 515 | dm_report_EIO(m); /* Failed */ |
f98e0eb6 | 516 | return DM_MAPIO_KILL; |
518257b1 MS |
517 | } else if (test_bit(MPATHF_QUEUE_IO, &m->flags) || |
518 | test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) { | |
c1d7ecf7 BVA |
519 | if (pg_init_all_paths(m)) |
520 | return DM_MAPIO_DELAY_REQUEUE; | |
06eb061f | 521 | return DM_MAPIO_REQUEUE; |
9bf59a61 | 522 | } |
6afbc01d | 523 | |
eb8db831 | 524 | memset(mpio, 0, sizeof(*mpio)); |
2eb6e1e3 KB |
525 | mpio->pgpath = pgpath; |
526 | mpio->nr_bytes = nr_bytes; | |
527 | ||
9bf59a61 | 528 | bdev = pgpath->path.dev->bdev; |
7083abbb BVA |
529 | q = bdev_get_queue(bdev); |
530 | clone = blk_get_request(q, rq->cmd_flags | REQ_NOMERGE, GFP_ATOMIC); | |
eb8db831 CH |
531 | if (IS_ERR(clone)) { |
532 | /* EBUSY, ENODEV or EWOULDBLOCK: requeue */ | |
7083abbb | 533 | bool queue_dying = blk_queue_dying(q); |
7083abbb BVA |
534 | if (queue_dying) { |
535 | atomic_inc(&m->pg_init_in_progress); | |
536 | activate_or_offline_path(pgpath); | |
49406657 | 537 | return DM_MAPIO_DELAY_REQUEUE; |
7083abbb | 538 | } |
49406657 ML |
539 | |
540 | /* | |
541 | * blk-mq's SCHED_RESTART can cover this requeue, so we | |
542 | * needn't deal with it by DELAY_REQUEUE. More importantly, | |
543 | * we have to return DM_MAPIO_REQUEUE so that blk-mq can | |
544 | * get the queue busy feedback (via BLK_STS_RESOURCE), | |
545 | * otherwise I/O merging can suffer. | |
546 | */ | |
547 | if (q->mq_ops) | |
548 | return DM_MAPIO_REQUEUE; | |
549 | else | |
550 | return DM_MAPIO_DELAY_REQUEUE; | |
e5863d9a | 551 | } |
eb8db831 CH |
552 | clone->bio = clone->biotail = NULL; |
553 | clone->rq_disk = bdev->bd_disk; | |
554 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; | |
555 | *__clone = clone; | |
e5863d9a | 556 | |
9bf59a61 MS |
557 | if (pgpath->pg->ps.type->start_io) |
558 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
559 | &pgpath->path, | |
560 | nr_bytes); | |
2eb6e1e3 | 561 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
562 | } |
563 | ||
e5863d9a MS |
564 | static void multipath_release_clone(struct request *clone) |
565 | { | |
eb8db831 | 566 | blk_put_request(clone); |
e5863d9a MS |
567 | } |
568 | ||
76e33fe4 MS |
569 | /* |
570 | * Map cloned bios (bio-based multipath) | |
571 | */ | |
572 | static int __multipath_map_bio(struct multipath *m, struct bio *bio, struct dm_mpath_io *mpio) | |
573 | { | |
574 | size_t nr_bytes = bio->bi_iter.bi_size; | |
575 | struct pgpath *pgpath; | |
576 | unsigned long flags; | |
577 | bool queue_io; | |
578 | ||
579 | /* Do we need to select a new pgpath? */ | |
506458ef | 580 | pgpath = READ_ONCE(m->current_pgpath); |
76e33fe4 MS |
581 | queue_io = test_bit(MPATHF_QUEUE_IO, &m->flags); |
582 | if (!pgpath || !queue_io) | |
583 | pgpath = choose_pgpath(m, nr_bytes); | |
584 | ||
585 | if ((pgpath && queue_io) || | |
586 | (!pgpath && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags))) { | |
587 | /* Queue for the daemon to resubmit */ | |
588 | spin_lock_irqsave(&m->lock, flags); | |
589 | bio_list_add(&m->queued_bios, bio); | |
590 | spin_unlock_irqrestore(&m->lock, flags); | |
591 | /* PG_INIT_REQUIRED cannot be set without QUEUE_IO */ | |
592 | if (queue_io || test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) | |
593 | pg_init_all_paths(m); | |
594 | else if (!queue_io) | |
595 | queue_work(kmultipathd, &m->process_queued_bios); | |
596 | return DM_MAPIO_SUBMITTED; | |
597 | } | |
598 | ||
599 | if (!pgpath) { | |
c1fd0abe | 600 | if (must_push_back_bio(m)) |
ca5beb76 | 601 | return DM_MAPIO_REQUEUE; |
18a482f5 | 602 | dm_report_EIO(m); |
846785e6 | 603 | return DM_MAPIO_KILL; |
76e33fe4 MS |
604 | } |
605 | ||
606 | mpio->pgpath = pgpath; | |
607 | mpio->nr_bytes = nr_bytes; | |
608 | ||
4e4cbee9 | 609 | bio->bi_status = 0; |
74d46992 | 610 | bio_set_dev(bio, pgpath->path.dev->bdev); |
1eff9d32 | 611 | bio->bi_opf |= REQ_FAILFAST_TRANSPORT; |
76e33fe4 MS |
612 | |
613 | if (pgpath->pg->ps.type->start_io) | |
614 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
615 | &pgpath->path, | |
616 | nr_bytes); | |
617 | return DM_MAPIO_REMAPPED; | |
618 | } | |
619 | ||
620 | static int multipath_map_bio(struct dm_target *ti, struct bio *bio) | |
621 | { | |
622 | struct multipath *m = ti->private; | |
bf661be1 MS |
623 | struct dm_mpath_io *mpio = NULL; |
624 | ||
625 | multipath_init_per_bio_data(bio, &mpio, NULL); | |
76e33fe4 MS |
626 | |
627 | return __multipath_map_bio(m, bio, mpio); | |
628 | } | |
629 | ||
7e48c768 | 630 | static void process_queued_io_list(struct multipath *m) |
76e33fe4 | 631 | { |
7e48c768 MS |
632 | if (m->queue_mode == DM_TYPE_MQ_REQUEST_BASED) |
633 | dm_mq_kick_requeue_list(dm_table_get_md(m->ti->table)); | |
634 | else if (m->queue_mode == DM_TYPE_BIO_BASED) | |
76e33fe4 MS |
635 | queue_work(kmultipathd, &m->process_queued_bios); |
636 | } | |
637 | ||
638 | static void process_queued_bios(struct work_struct *work) | |
639 | { | |
640 | int r; | |
641 | unsigned long flags; | |
642 | struct bio *bio; | |
643 | struct bio_list bios; | |
644 | struct blk_plug plug; | |
645 | struct multipath *m = | |
646 | container_of(work, struct multipath, process_queued_bios); | |
647 | ||
648 | bio_list_init(&bios); | |
649 | ||
650 | spin_lock_irqsave(&m->lock, flags); | |
651 | ||
652 | if (bio_list_empty(&m->queued_bios)) { | |
653 | spin_unlock_irqrestore(&m->lock, flags); | |
654 | return; | |
655 | } | |
656 | ||
657 | bio_list_merge(&bios, &m->queued_bios); | |
658 | bio_list_init(&m->queued_bios); | |
659 | ||
660 | spin_unlock_irqrestore(&m->lock, flags); | |
661 | ||
662 | blk_start_plug(&plug); | |
663 | while ((bio = bio_list_pop(&bios))) { | |
664 | r = __multipath_map_bio(m, bio, get_mpio_from_bio(bio)); | |
846785e6 CH |
665 | switch (r) { |
666 | case DM_MAPIO_KILL: | |
4e4cbee9 CH |
667 | bio->bi_status = BLK_STS_IOERR; |
668 | bio_endio(bio); | |
047385b3 | 669 | break; |
846785e6 | 670 | case DM_MAPIO_REQUEUE: |
4e4cbee9 | 671 | bio->bi_status = BLK_STS_DM_REQUEUE; |
76e33fe4 | 672 | bio_endio(bio); |
846785e6 CH |
673 | break; |
674 | case DM_MAPIO_REMAPPED: | |
76e33fe4 | 675 | generic_make_request(bio); |
846785e6 | 676 | break; |
9157c8d3 BVA |
677 | case 0: |
678 | break; | |
679 | default: | |
680 | WARN_ONCE(true, "__multipath_map_bio() returned %d\n", r); | |
846785e6 | 681 | } |
76e33fe4 MS |
682 | } |
683 | blk_finish_plug(&plug); | |
684 | } | |
685 | ||
1da177e4 LT |
686 | /* |
687 | * If we run out of usable paths, should we queue I/O or error it? | |
688 | */ | |
be7d31cc MS |
689 | static int queue_if_no_path(struct multipath *m, bool queue_if_no_path, |
690 | bool save_old_value) | |
1da177e4 LT |
691 | { |
692 | unsigned long flags; | |
693 | ||
694 | spin_lock_irqsave(&m->lock, flags); | |
5307e2ad LW |
695 | assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, |
696 | (save_old_value && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) || | |
697 | (!save_old_value && queue_if_no_path)); | |
c1fd0abe | 698 | assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path); |
1da177e4 LT |
699 | spin_unlock_irqrestore(&m->lock, flags); |
700 | ||
76e33fe4 | 701 | if (!queue_if_no_path) { |
63d832c3 | 702 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 703 | process_queued_io_list(m); |
76e33fe4 | 704 | } |
63d832c3 | 705 | |
1da177e4 LT |
706 | return 0; |
707 | } | |
708 | ||
1da177e4 LT |
709 | /* |
710 | * An event is triggered whenever a path is taken out of use. | |
711 | * Includes path failure and PG bypass. | |
712 | */ | |
c4028958 | 713 | static void trigger_event(struct work_struct *work) |
1da177e4 | 714 | { |
c4028958 DH |
715 | struct multipath *m = |
716 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
717 | |
718 | dm_table_event(m->ti->table); | |
719 | } | |
720 | ||
721 | /*----------------------------------------------------------------- | |
722 | * Constructor/argument parsing: | |
723 | * <#multipath feature args> [<arg>]* | |
724 | * <#hw_handler args> [hw_handler [<arg>]*] | |
725 | * <#priority groups> | |
726 | * <initial priority group> | |
727 | * [<selector> <#selector args> [<arg>]* | |
728 | * <#paths> <#per-path selector args> | |
729 | * [<path> [<arg>]* ]+ ]+ | |
730 | *---------------------------------------------------------------*/ | |
498f0103 | 731 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
1da177e4 LT |
732 | struct dm_target *ti) |
733 | { | |
734 | int r; | |
735 | struct path_selector_type *pst; | |
736 | unsigned ps_argc; | |
737 | ||
5916a22b | 738 | static const struct dm_arg _args[] = { |
72d94861 | 739 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
740 | }; |
741 | ||
498f0103 | 742 | pst = dm_get_path_selector(dm_shift_arg(as)); |
1da177e4 | 743 | if (!pst) { |
72d94861 | 744 | ti->error = "unknown path selector type"; |
1da177e4 LT |
745 | return -EINVAL; |
746 | } | |
747 | ||
498f0103 | 748 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
371b2e34 MP |
749 | if (r) { |
750 | dm_put_path_selector(pst); | |
1da177e4 | 751 | return -EINVAL; |
371b2e34 | 752 | } |
1da177e4 LT |
753 | |
754 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
755 | if (r) { | |
756 | dm_put_path_selector(pst); | |
72d94861 | 757 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
758 | return r; |
759 | } | |
760 | ||
761 | pg->ps.type = pst; | |
498f0103 | 762 | dm_consume_args(as, ps_argc); |
1da177e4 LT |
763 | |
764 | return 0; | |
765 | } | |
766 | ||
498f0103 | 767 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, |
1da177e4 LT |
768 | struct dm_target *ti) |
769 | { | |
770 | int r; | |
771 | struct pgpath *p; | |
ae11b1b3 | 772 | struct multipath *m = ti->private; |
a58a935d MS |
773 | struct request_queue *q = NULL; |
774 | const char *attached_handler_name; | |
1da177e4 LT |
775 | |
776 | /* we need at least a path arg */ | |
777 | if (as->argc < 1) { | |
72d94861 | 778 | ti->error = "no device given"; |
01460f35 | 779 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
780 | } |
781 | ||
782 | p = alloc_pgpath(); | |
783 | if (!p) | |
01460f35 | 784 | return ERR_PTR(-ENOMEM); |
1da177e4 | 785 | |
498f0103 | 786 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), |
8215d6ec | 787 | &p->path.dev); |
1da177e4 | 788 | if (r) { |
72d94861 | 789 | ti->error = "error getting device"; |
1da177e4 LT |
790 | goto bad; |
791 | } | |
792 | ||
518257b1 | 793 | if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) || m->hw_handler_name) |
a58a935d MS |
794 | q = bdev_get_queue(p->path.dev->bdev); |
795 | ||
518257b1 | 796 | if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) { |
1bab0de0 | 797 | retain: |
a58a935d MS |
798 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); |
799 | if (attached_handler_name) { | |
54cd640d | 800 | /* |
801 | * Clear any hw_handler_params associated with a | |
802 | * handler that isn't already attached. | |
803 | */ | |
804 | if (m->hw_handler_name && strcmp(attached_handler_name, m->hw_handler_name)) { | |
805 | kfree(m->hw_handler_params); | |
806 | m->hw_handler_params = NULL; | |
807 | } | |
808 | ||
a58a935d MS |
809 | /* |
810 | * Reset hw_handler_name to match the attached handler | |
a58a935d MS |
811 | * |
812 | * NB. This modifies the table line to show the actual | |
813 | * handler instead of the original table passed in. | |
814 | */ | |
815 | kfree(m->hw_handler_name); | |
816 | m->hw_handler_name = attached_handler_name; | |
a58a935d MS |
817 | } |
818 | } | |
a0cf7ea9 | 819 | |
a58a935d | 820 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
821 | r = scsi_dh_attach(q, m->hw_handler_name); |
822 | if (r == -EBUSY) { | |
1bab0de0 | 823 | char b[BDEVNAME_SIZE]; |
a0cf7ea9 | 824 | |
1bab0de0 CH |
825 | printk(KERN_INFO "dm-mpath: retaining handler on device %s\n", |
826 | bdevname(p->path.dev->bdev, b)); | |
827 | goto retain; | |
828 | } | |
ae11b1b3 | 829 | if (r < 0) { |
a0cf7ea9 | 830 | ti->error = "error attaching hardware handler"; |
ae11b1b3 HR |
831 | dm_put_device(ti, p->path.dev); |
832 | goto bad; | |
833 | } | |
2bfd2e13 CS |
834 | |
835 | if (m->hw_handler_params) { | |
836 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
837 | if (r < 0) { | |
838 | ti->error = "unable to set hardware " | |
839 | "handler parameters"; | |
2bfd2e13 CS |
840 | dm_put_device(ti, p->path.dev); |
841 | goto bad; | |
842 | } | |
843 | } | |
ae11b1b3 HR |
844 | } |
845 | ||
1da177e4 LT |
846 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
847 | if (r) { | |
848 | dm_put_device(ti, p->path.dev); | |
849 | goto bad; | |
850 | } | |
851 | ||
852 | return p; | |
853 | ||
854 | bad: | |
855 | free_pgpath(p); | |
01460f35 | 856 | return ERR_PTR(r); |
1da177e4 LT |
857 | } |
858 | ||
498f0103 | 859 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
28f16c20 | 860 | struct multipath *m) |
1da177e4 | 861 | { |
5916a22b | 862 | static const struct dm_arg _args[] = { |
72d94861 AK |
863 | {1, 1024, "invalid number of paths"}, |
864 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
865 | }; |
866 | ||
867 | int r; | |
498f0103 | 868 | unsigned i, nr_selector_args, nr_args; |
1da177e4 | 869 | struct priority_group *pg; |
28f16c20 | 870 | struct dm_target *ti = m->ti; |
1da177e4 LT |
871 | |
872 | if (as->argc < 2) { | |
873 | as->argc = 0; | |
01460f35 BM |
874 | ti->error = "not enough priority group arguments"; |
875 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
876 | } |
877 | ||
878 | pg = alloc_priority_group(); | |
879 | if (!pg) { | |
72d94861 | 880 | ti->error = "couldn't allocate priority group"; |
01460f35 | 881 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
882 | } |
883 | pg->m = m; | |
884 | ||
885 | r = parse_path_selector(as, pg, ti); | |
886 | if (r) | |
887 | goto bad; | |
888 | ||
889 | /* | |
890 | * read the paths | |
891 | */ | |
498f0103 | 892 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
1da177e4 LT |
893 | if (r) |
894 | goto bad; | |
895 | ||
498f0103 | 896 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
1da177e4 LT |
897 | if (r) |
898 | goto bad; | |
899 | ||
498f0103 | 900 | nr_args = 1 + nr_selector_args; |
1da177e4 LT |
901 | for (i = 0; i < pg->nr_pgpaths; i++) { |
902 | struct pgpath *pgpath; | |
498f0103 | 903 | struct dm_arg_set path_args; |
1da177e4 | 904 | |
498f0103 | 905 | if (as->argc < nr_args) { |
148acff6 | 906 | ti->error = "not enough path parameters"; |
6bbf79a1 | 907 | r = -EINVAL; |
1da177e4 | 908 | goto bad; |
148acff6 | 909 | } |
1da177e4 | 910 | |
498f0103 | 911 | path_args.argc = nr_args; |
1da177e4 LT |
912 | path_args.argv = as->argv; |
913 | ||
914 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
915 | if (IS_ERR(pgpath)) { |
916 | r = PTR_ERR(pgpath); | |
1da177e4 | 917 | goto bad; |
01460f35 | 918 | } |
1da177e4 LT |
919 | |
920 | pgpath->pg = pg; | |
921 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
498f0103 | 922 | dm_consume_args(as, nr_args); |
1da177e4 LT |
923 | } |
924 | ||
925 | return pg; | |
926 | ||
927 | bad: | |
928 | free_priority_group(pg, ti); | |
01460f35 | 929 | return ERR_PTR(r); |
1da177e4 LT |
930 | } |
931 | ||
498f0103 | 932 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
1da177e4 | 933 | { |
1da177e4 | 934 | unsigned hw_argc; |
2bfd2e13 | 935 | int ret; |
28f16c20 | 936 | struct dm_target *ti = m->ti; |
1da177e4 | 937 | |
5916a22b | 938 | static const struct dm_arg _args[] = { |
72d94861 | 939 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
940 | }; |
941 | ||
498f0103 | 942 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
1da177e4 LT |
943 | return -EINVAL; |
944 | ||
945 | if (!hw_argc) | |
946 | return 0; | |
947 | ||
e83068a5 | 948 | if (m->queue_mode == DM_TYPE_BIO_BASED) { |
76e33fe4 MS |
949 | dm_consume_args(as, hw_argc); |
950 | DMERR("bio-based multipath doesn't allow hardware handler args"); | |
951 | return 0; | |
952 | } | |
953 | ||
498f0103 | 954 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
f97dc421 | 955 | if (!m->hw_handler_name) |
956 | return -EINVAL; | |
14e98c5c | 957 | |
2bfd2e13 CS |
958 | if (hw_argc > 1) { |
959 | char *p; | |
960 | int i, j, len = 4; | |
961 | ||
962 | for (i = 0; i <= hw_argc - 2; i++) | |
963 | len += strlen(as->argv[i]) + 1; | |
964 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
965 | if (!p) { | |
966 | ti->error = "memory allocation failed"; | |
967 | ret = -ENOMEM; | |
968 | goto fail; | |
969 | } | |
970 | j = sprintf(p, "%d", hw_argc - 1); | |
971 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
972 | j = sprintf(p, "%s", as->argv[i]); | |
973 | } | |
498f0103 | 974 | dm_consume_args(as, hw_argc - 1); |
1da177e4 LT |
975 | |
976 | return 0; | |
2bfd2e13 CS |
977 | fail: |
978 | kfree(m->hw_handler_name); | |
979 | m->hw_handler_name = NULL; | |
980 | return ret; | |
1da177e4 LT |
981 | } |
982 | ||
498f0103 | 983 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
1da177e4 LT |
984 | { |
985 | int r; | |
986 | unsigned argc; | |
28f16c20 | 987 | struct dm_target *ti = m->ti; |
498f0103 | 988 | const char *arg_name; |
1da177e4 | 989 | |
5916a22b | 990 | static const struct dm_arg _args[] = { |
e83068a5 | 991 | {0, 8, "invalid number of feature args"}, |
c9e45581 | 992 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
4e2d19e4 | 993 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
1da177e4 LT |
994 | }; |
995 | ||
498f0103 | 996 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
1da177e4 LT |
997 | if (r) |
998 | return -EINVAL; | |
999 | ||
1000 | if (!argc) | |
1001 | return 0; | |
1002 | ||
c9e45581 | 1003 | do { |
498f0103 | 1004 | arg_name = dm_shift_arg(as); |
c9e45581 DW |
1005 | argc--; |
1006 | ||
498f0103 | 1007 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
be7d31cc | 1008 | r = queue_if_no_path(m, true, false); |
c9e45581 DW |
1009 | continue; |
1010 | } | |
1011 | ||
a58a935d | 1012 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
518257b1 | 1013 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); |
a58a935d MS |
1014 | continue; |
1015 | } | |
1016 | ||
498f0103 | 1017 | if (!strcasecmp(arg_name, "pg_init_retries") && |
c9e45581 | 1018 | (argc >= 1)) { |
498f0103 | 1019 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
c9e45581 DW |
1020 | argc--; |
1021 | continue; | |
1022 | } | |
1023 | ||
498f0103 | 1024 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
4e2d19e4 | 1025 | (argc >= 1)) { |
498f0103 | 1026 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
4e2d19e4 CS |
1027 | argc--; |
1028 | continue; | |
1029 | } | |
1030 | ||
e83068a5 MS |
1031 | if (!strcasecmp(arg_name, "queue_mode") && |
1032 | (argc >= 1)) { | |
1033 | const char *queue_mode_name = dm_shift_arg(as); | |
1034 | ||
1035 | if (!strcasecmp(queue_mode_name, "bio")) | |
1036 | m->queue_mode = DM_TYPE_BIO_BASED; | |
1037 | else if (!strcasecmp(queue_mode_name, "rq")) | |
1038 | m->queue_mode = DM_TYPE_REQUEST_BASED; | |
1039 | else if (!strcasecmp(queue_mode_name, "mq")) | |
1040 | m->queue_mode = DM_TYPE_MQ_REQUEST_BASED; | |
1041 | else { | |
1042 | ti->error = "Unknown 'queue_mode' requested"; | |
1043 | r = -EINVAL; | |
1044 | } | |
1045 | argc--; | |
1046 | continue; | |
1047 | } | |
1048 | ||
1da177e4 | 1049 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
1050 | r = -EINVAL; |
1051 | } while (argc && !r); | |
1052 | ||
1053 | return r; | |
1da177e4 LT |
1054 | } |
1055 | ||
e83068a5 | 1056 | static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) |
1da177e4 | 1057 | { |
498f0103 | 1058 | /* target arguments */ |
5916a22b | 1059 | static const struct dm_arg _args[] = { |
a490a07a MS |
1060 | {0, 1024, "invalid number of priority groups"}, |
1061 | {0, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
1062 | }; |
1063 | ||
1064 | int r; | |
1065 | struct multipath *m; | |
498f0103 | 1066 | struct dm_arg_set as; |
1da177e4 LT |
1067 | unsigned pg_count = 0; |
1068 | unsigned next_pg_num; | |
1069 | ||
1070 | as.argc = argc; | |
1071 | as.argv = argv; | |
1072 | ||
e83068a5 | 1073 | m = alloc_multipath(ti); |
1da177e4 | 1074 | if (!m) { |
72d94861 | 1075 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
1076 | return -EINVAL; |
1077 | } | |
1078 | ||
28f16c20 | 1079 | r = parse_features(&as, m); |
1da177e4 LT |
1080 | if (r) |
1081 | goto bad; | |
1082 | ||
e83068a5 MS |
1083 | r = alloc_multipath_stage2(ti, m); |
1084 | if (r) | |
1085 | goto bad; | |
1086 | ||
28f16c20 | 1087 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
1088 | if (r) |
1089 | goto bad; | |
1090 | ||
498f0103 | 1091 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
1da177e4 LT |
1092 | if (r) |
1093 | goto bad; | |
1094 | ||
498f0103 | 1095 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
1da177e4 LT |
1096 | if (r) |
1097 | goto bad; | |
1098 | ||
a490a07a MS |
1099 | if ((!m->nr_priority_groups && next_pg_num) || |
1100 | (m->nr_priority_groups && !next_pg_num)) { | |
1101 | ti->error = "invalid initial priority group"; | |
1102 | r = -EINVAL; | |
1103 | goto bad; | |
1104 | } | |
1105 | ||
1da177e4 LT |
1106 | /* parse the priority groups */ |
1107 | while (as.argc) { | |
1108 | struct priority_group *pg; | |
91e968aa | 1109 | unsigned nr_valid_paths = atomic_read(&m->nr_valid_paths); |
1da177e4 | 1110 | |
28f16c20 | 1111 | pg = parse_priority_group(&as, m); |
01460f35 BM |
1112 | if (IS_ERR(pg)) { |
1113 | r = PTR_ERR(pg); | |
1da177e4 LT |
1114 | goto bad; |
1115 | } | |
1116 | ||
91e968aa MS |
1117 | nr_valid_paths += pg->nr_pgpaths; |
1118 | atomic_set(&m->nr_valid_paths, nr_valid_paths); | |
1119 | ||
1da177e4 LT |
1120 | list_add_tail(&pg->list, &m->priority_groups); |
1121 | pg_count++; | |
1122 | pg->pg_num = pg_count; | |
1123 | if (!--next_pg_num) | |
1124 | m->next_pg = pg; | |
1125 | } | |
1126 | ||
1127 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 1128 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
1129 | r = -EINVAL; |
1130 | goto bad; | |
1131 | } | |
1132 | ||
55a62eef AK |
1133 | ti->num_flush_bios = 1; |
1134 | ti->num_discard_bios = 1; | |
042bcef8 | 1135 | ti->num_write_same_bios = 1; |
ac62d620 | 1136 | ti->num_write_zeroes_bios = 1; |
e83068a5 | 1137 | if (m->queue_mode == DM_TYPE_BIO_BASED) |
bf661be1 | 1138 | ti->per_io_data_size = multipath_per_bio_data_size(); |
eb8db831 | 1139 | else |
8637a6bf | 1140 | ti->per_io_data_size = sizeof(struct dm_mpath_io); |
8627921f | 1141 | |
1da177e4 LT |
1142 | return 0; |
1143 | ||
1144 | bad: | |
1145 | free_multipath(m); | |
1146 | return r; | |
1147 | } | |
1148 | ||
2bded7bd KU |
1149 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
1150 | { | |
9f4c3f87 | 1151 | DEFINE_WAIT(wait); |
2bded7bd KU |
1152 | |
1153 | while (1) { | |
9f4c3f87 | 1154 | prepare_to_wait(&m->pg_init_wait, &wait, TASK_UNINTERRUPTIBLE); |
2bded7bd | 1155 | |
91e968aa | 1156 | if (!atomic_read(&m->pg_init_in_progress)) |
2bded7bd | 1157 | break; |
2bded7bd KU |
1158 | |
1159 | io_schedule(); | |
1160 | } | |
9f4c3f87 | 1161 | finish_wait(&m->pg_init_wait, &wait); |
2bded7bd KU |
1162 | } |
1163 | ||
1164 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 1165 | { |
518257b1 MS |
1166 | set_bit(MPATHF_PG_INIT_DISABLED, &m->flags); |
1167 | smp_mb__after_atomic(); | |
954a73d5 | 1168 | |
bab7cfc7 | 1169 | flush_workqueue(kmpath_handlerd); |
2bded7bd | 1170 | multipath_wait_for_pg_init_completion(m); |
a044d016 | 1171 | flush_workqueue(kmultipathd); |
43829731 | 1172 | flush_work(&m->trigger_event); |
954a73d5 | 1173 | |
518257b1 MS |
1174 | clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags); |
1175 | smp_mb__after_atomic(); | |
6df400ab KU |
1176 | } |
1177 | ||
1178 | static void multipath_dtr(struct dm_target *ti) | |
1179 | { | |
1180 | struct multipath *m = ti->private; | |
1181 | ||
2bded7bd | 1182 | flush_multipath_work(m); |
1da177e4 LT |
1183 | free_multipath(m); |
1184 | } | |
1185 | ||
1da177e4 LT |
1186 | /* |
1187 | * Take a path out of use. | |
1188 | */ | |
1189 | static int fail_path(struct pgpath *pgpath) | |
1190 | { | |
1191 | unsigned long flags; | |
1192 | struct multipath *m = pgpath->pg->m; | |
1193 | ||
1194 | spin_lock_irqsave(&m->lock, flags); | |
1195 | ||
6680073d | 1196 | if (!pgpath->is_active) |
1da177e4 LT |
1197 | goto out; |
1198 | ||
72d94861 | 1199 | DMWARN("Failing path %s.", pgpath->path.dev->name); |
1da177e4 LT |
1200 | |
1201 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
be7d31cc | 1202 | pgpath->is_active = false; |
1da177e4 LT |
1203 | pgpath->fail_count++; |
1204 | ||
91e968aa | 1205 | atomic_dec(&m->nr_valid_paths); |
1da177e4 LT |
1206 | |
1207 | if (pgpath == m->current_pgpath) | |
1208 | m->current_pgpath = NULL; | |
1209 | ||
b15546f9 | 1210 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
91e968aa | 1211 | pgpath->path.dev->name, atomic_read(&m->nr_valid_paths)); |
b15546f9 | 1212 | |
fe9cf30e | 1213 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1214 | |
1215 | out: | |
1216 | spin_unlock_irqrestore(&m->lock, flags); | |
1217 | ||
1218 | return 0; | |
1219 | } | |
1220 | ||
1221 | /* | |
1222 | * Reinstate a previously-failed path | |
1223 | */ | |
1224 | static int reinstate_path(struct pgpath *pgpath) | |
1225 | { | |
63d832c3 | 1226 | int r = 0, run_queue = 0; |
1da177e4 LT |
1227 | unsigned long flags; |
1228 | struct multipath *m = pgpath->pg->m; | |
91e968aa | 1229 | unsigned nr_valid_paths; |
1da177e4 LT |
1230 | |
1231 | spin_lock_irqsave(&m->lock, flags); | |
1232 | ||
6680073d | 1233 | if (pgpath->is_active) |
1da177e4 LT |
1234 | goto out; |
1235 | ||
ec31f3f7 | 1236 | DMWARN("Reinstating path %s.", pgpath->path.dev->name); |
1da177e4 LT |
1237 | |
1238 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1239 | if (r) | |
1240 | goto out; | |
1241 | ||
be7d31cc | 1242 | pgpath->is_active = true; |
1da177e4 | 1243 | |
91e968aa MS |
1244 | nr_valid_paths = atomic_inc_return(&m->nr_valid_paths); |
1245 | if (nr_valid_paths == 1) { | |
e54f77dd | 1246 | m->current_pgpath = NULL; |
63d832c3 | 1247 | run_queue = 1; |
e54f77dd | 1248 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
4e2d19e4 | 1249 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
91e968aa | 1250 | atomic_inc(&m->pg_init_in_progress); |
e54f77dd | 1251 | } |
1da177e4 | 1252 | |
b15546f9 | 1253 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
91e968aa | 1254 | pgpath->path.dev->name, nr_valid_paths); |
b15546f9 | 1255 | |
fe9cf30e | 1256 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1257 | |
1258 | out: | |
1259 | spin_unlock_irqrestore(&m->lock, flags); | |
76e33fe4 | 1260 | if (run_queue) { |
63d832c3 | 1261 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 1262 | process_queued_io_list(m); |
76e33fe4 | 1263 | } |
1da177e4 LT |
1264 | |
1265 | return r; | |
1266 | } | |
1267 | ||
1268 | /* | |
1269 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1270 | */ | |
1271 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1272 | action_fn action) | |
1273 | { | |
19040c0b | 1274 | int r = -EINVAL; |
1da177e4 LT |
1275 | struct pgpath *pgpath; |
1276 | struct priority_group *pg; | |
1277 | ||
1278 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1279 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1280 | if (pgpath->path.dev == dev) | |
1281 | r = action(pgpath); | |
1282 | } | |
1283 | } | |
1284 | ||
1285 | return r; | |
1286 | } | |
1287 | ||
1288 | /* | |
1289 | * Temporarily try to avoid having to use the specified PG | |
1290 | */ | |
1291 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
be7d31cc | 1292 | bool bypassed) |
1da177e4 LT |
1293 | { |
1294 | unsigned long flags; | |
1295 | ||
1296 | spin_lock_irqsave(&m->lock, flags); | |
1297 | ||
1298 | pg->bypassed = bypassed; | |
1299 | m->current_pgpath = NULL; | |
1300 | m->current_pg = NULL; | |
1301 | ||
1302 | spin_unlock_irqrestore(&m->lock, flags); | |
1303 | ||
fe9cf30e | 1304 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1305 | } |
1306 | ||
1307 | /* | |
1308 | * Switch to using the specified PG from the next I/O that gets mapped | |
1309 | */ | |
1310 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1311 | { | |
1312 | struct priority_group *pg; | |
1313 | unsigned pgnum; | |
1314 | unsigned long flags; | |
31998ef1 | 1315 | char dummy; |
1da177e4 | 1316 | |
31998ef1 | 1317 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1318 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1319 | DMWARN("invalid PG number supplied to switch_pg_num"); |
1320 | return -EINVAL; | |
1321 | } | |
1322 | ||
1323 | spin_lock_irqsave(&m->lock, flags); | |
1324 | list_for_each_entry(pg, &m->priority_groups, list) { | |
be7d31cc | 1325 | pg->bypassed = false; |
1da177e4 LT |
1326 | if (--pgnum) |
1327 | continue; | |
1328 | ||
1329 | m->current_pgpath = NULL; | |
1330 | m->current_pg = NULL; | |
1331 | m->next_pg = pg; | |
1332 | } | |
1333 | spin_unlock_irqrestore(&m->lock, flags); | |
1334 | ||
fe9cf30e | 1335 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1336 | return 0; |
1337 | } | |
1338 | ||
1339 | /* | |
1340 | * Set/clear bypassed status of a PG. | |
1341 | * PGs are numbered upwards from 1 in the order they were declared. | |
1342 | */ | |
be7d31cc | 1343 | static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) |
1da177e4 LT |
1344 | { |
1345 | struct priority_group *pg; | |
1346 | unsigned pgnum; | |
31998ef1 | 1347 | char dummy; |
1da177e4 | 1348 | |
31998ef1 | 1349 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1350 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1351 | DMWARN("invalid PG number supplied to bypass_pg"); |
1352 | return -EINVAL; | |
1353 | } | |
1354 | ||
1355 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1356 | if (!--pgnum) | |
1357 | break; | |
1358 | } | |
1359 | ||
1360 | bypass_pg(m, pg, bypassed); | |
1361 | return 0; | |
1362 | } | |
1363 | ||
c9e45581 DW |
1364 | /* |
1365 | * Should we retry pg_init immediately? | |
1366 | */ | |
be7d31cc | 1367 | static bool pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) |
c9e45581 DW |
1368 | { |
1369 | unsigned long flags; | |
be7d31cc | 1370 | bool limit_reached = false; |
c9e45581 DW |
1371 | |
1372 | spin_lock_irqsave(&m->lock, flags); | |
1373 | ||
91e968aa MS |
1374 | if (atomic_read(&m->pg_init_count) <= m->pg_init_retries && |
1375 | !test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) | |
518257b1 | 1376 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
c9e45581 | 1377 | else |
be7d31cc | 1378 | limit_reached = true; |
c9e45581 DW |
1379 | |
1380 | spin_unlock_irqrestore(&m->lock, flags); | |
1381 | ||
1382 | return limit_reached; | |
1383 | } | |
1384 | ||
3ae31f6a | 1385 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1386 | { |
83c0d5d5 | 1387 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1388 | struct priority_group *pg = pgpath->pg; |
1389 | struct multipath *m = pg->m; | |
1390 | unsigned long flags; | |
be7d31cc | 1391 | bool delay_retry = false; |
cfae5c9b CS |
1392 | |
1393 | /* device or driver problems */ | |
1394 | switch (errors) { | |
1395 | case SCSI_DH_OK: | |
1396 | break; | |
1397 | case SCSI_DH_NOSYS: | |
1398 | if (!m->hw_handler_name) { | |
1399 | errors = 0; | |
1400 | break; | |
1401 | } | |
f7b934c8 MB |
1402 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1403 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1404 | /* |
1405 | * Fail path for now, so we do not ping pong | |
1406 | */ | |
1407 | fail_path(pgpath); | |
1408 | break; | |
1409 | case SCSI_DH_DEV_TEMP_BUSY: | |
1410 | /* | |
1411 | * Probably doing something like FW upgrade on the | |
1412 | * controller so try the other pg. | |
1413 | */ | |
be7d31cc | 1414 | bypass_pg(m, pg, true); |
cfae5c9b | 1415 | break; |
cfae5c9b | 1416 | case SCSI_DH_RETRY: |
4e2d19e4 CS |
1417 | /* Wait before retrying. */ |
1418 | delay_retry = 1; | |
7b06e09a | 1419 | /* fall through */ |
cfae5c9b CS |
1420 | case SCSI_DH_IMM_RETRY: |
1421 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1422 | if (pg_init_limit_reached(m, pgpath)) | |
1423 | fail_path(pgpath); | |
1424 | errors = 0; | |
1425 | break; | |
ec31f3f7 | 1426 | case SCSI_DH_DEV_OFFLINED: |
cfae5c9b CS |
1427 | default: |
1428 | /* | |
1429 | * We probably do not want to fail the path for a device | |
1430 | * error, but this is what the old dm did. In future | |
1431 | * patches we can do more advanced handling. | |
1432 | */ | |
1433 | fail_path(pgpath); | |
1434 | } | |
1435 | ||
1436 | spin_lock_irqsave(&m->lock, flags); | |
1437 | if (errors) { | |
e54f77dd CS |
1438 | if (pgpath == m->current_pgpath) { |
1439 | DMERR("Could not failover device. Error %d.", errors); | |
1440 | m->current_pgpath = NULL; | |
1441 | m->current_pg = NULL; | |
1442 | } | |
518257b1 | 1443 | } else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
be7d31cc | 1444 | pg->bypassed = false; |
cfae5c9b | 1445 | |
91e968aa | 1446 | if (atomic_dec_return(&m->pg_init_in_progress) > 0) |
d0259bf0 KU |
1447 | /* Activations of other paths are still on going */ |
1448 | goto out; | |
1449 | ||
518257b1 MS |
1450 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) { |
1451 | if (delay_retry) | |
1452 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1453 | else | |
1454 | clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1455 | ||
3e9f1be1 HR |
1456 | if (__pg_init_all_paths(m)) |
1457 | goto out; | |
1458 | } | |
518257b1 | 1459 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
d0259bf0 | 1460 | |
7e48c768 | 1461 | process_queued_io_list(m); |
76e33fe4 | 1462 | |
2bded7bd KU |
1463 | /* |
1464 | * Wake up any thread waiting to suspend. | |
1465 | */ | |
1466 | wake_up(&m->pg_init_wait); | |
1467 | ||
d0259bf0 | 1468 | out: |
cfae5c9b CS |
1469 | spin_unlock_irqrestore(&m->lock, flags); |
1470 | } | |
1471 | ||
89bfce76 | 1472 | static void activate_or_offline_path(struct pgpath *pgpath) |
bab7cfc7 | 1473 | { |
f10e06b7 | 1474 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); |
bab7cfc7 | 1475 | |
f10e06b7 MS |
1476 | if (pgpath->is_active && !blk_queue_dying(q)) |
1477 | scsi_dh_activate(q, pg_init_done, pgpath); | |
3a017509 HR |
1478 | else |
1479 | pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); | |
bab7cfc7 CS |
1480 | } |
1481 | ||
89bfce76 BVA |
1482 | static void activate_path_work(struct work_struct *work) |
1483 | { | |
1484 | struct pgpath *pgpath = | |
1485 | container_of(work, struct pgpath, activate_path.work); | |
1486 | ||
1487 | activate_or_offline_path(pgpath); | |
1488 | } | |
1489 | ||
2a842aca | 1490 | static int noretry_error(blk_status_t error) |
7e782af5 HR |
1491 | { |
1492 | switch (error) { | |
2a842aca CH |
1493 | case BLK_STS_NOTSUPP: |
1494 | case BLK_STS_NOSPC: | |
1495 | case BLK_STS_TARGET: | |
1496 | case BLK_STS_NEXUS: | |
1497 | case BLK_STS_MEDIUM: | |
7e782af5 HR |
1498 | return 1; |
1499 | } | |
1500 | ||
1501 | /* Anything else could be a path failure, so should be retried */ | |
1502 | return 0; | |
1503 | } | |
1504 | ||
b79f10ee | 1505 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
2a842aca | 1506 | blk_status_t error, union map_info *map_context) |
1da177e4 | 1507 | { |
b79f10ee CH |
1508 | struct dm_mpath_io *mpio = get_mpio(map_context); |
1509 | struct pgpath *pgpath = mpio->pgpath; | |
7ed8578a | 1510 | int r = DM_ENDIO_DONE; |
b79f10ee | 1511 | |
f40c67f0 KU |
1512 | /* |
1513 | * We don't queue any clone request inside the multipath target | |
1514 | * during end I/O handling, since those clone requests don't have | |
1515 | * bio clones. If we queue them inside the multipath target, | |
1516 | * we need to make bio clones, that requires memory allocation. | |
4cc96131 | 1517 | * (See drivers/md/dm-rq.c:end_clone_bio() about why the clone requests |
f40c67f0 KU |
1518 | * don't have bio clones.) |
1519 | * Instead of queueing the clone request here, we queue the original | |
1520 | * request into dm core, which will remake a clone request and | |
1521 | * clone bios for it and resubmit it later. | |
1522 | */ | |
b79f10ee CH |
1523 | if (error && !noretry_error(error)) { |
1524 | struct multipath *m = ti->private; | |
1da177e4 | 1525 | |
7ed8578a | 1526 | r = DM_ENDIO_REQUEUE; |
1da177e4 | 1527 | |
b79f10ee CH |
1528 | if (pgpath) |
1529 | fail_path(pgpath); | |
1da177e4 | 1530 | |
b79f10ee | 1531 | if (atomic_read(&m->nr_valid_paths) == 0 && |
c1fd0abe | 1532 | !must_push_back_rq(m)) { |
2a842aca | 1533 | if (error == BLK_STS_IOERR) |
18a482f5 | 1534 | dm_report_EIO(m); |
7ed8578a CH |
1535 | /* complete with the original error */ |
1536 | r = DM_ENDIO_DONE; | |
1537 | } | |
b79f10ee | 1538 | } |
466891f9 | 1539 | |
1da177e4 | 1540 | if (pgpath) { |
b79f10ee CH |
1541 | struct path_selector *ps = &pgpath->pg->ps; |
1542 | ||
1da177e4 | 1543 | if (ps->type->end_io) |
02ab823f | 1544 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); |
1da177e4 | 1545 | } |
1da177e4 | 1546 | |
7ed8578a | 1547 | return r; |
1da177e4 LT |
1548 | } |
1549 | ||
4e4cbee9 CH |
1550 | static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, |
1551 | blk_status_t *error) | |
76e33fe4 | 1552 | { |
14ef1e48 CH |
1553 | struct multipath *m = ti->private; |
1554 | struct dm_mpath_io *mpio = get_mpio_from_bio(clone); | |
1555 | struct pgpath *pgpath = mpio->pgpath; | |
76e33fe4 | 1556 | unsigned long flags; |
1be56909 | 1557 | int r = DM_ENDIO_DONE; |
76e33fe4 | 1558 | |
4e4cbee9 | 1559 | if (!*error || noretry_error(*error)) |
14ef1e48 | 1560 | goto done; |
76e33fe4 | 1561 | |
14ef1e48 CH |
1562 | if (pgpath) |
1563 | fail_path(pgpath); | |
76e33fe4 | 1564 | |
ca5beb76 | 1565 | if (atomic_read(&m->nr_valid_paths) == 0 && |
18a482f5 | 1566 | !test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { |
c1fd0abe MS |
1567 | if (must_push_back_bio(m)) { |
1568 | r = DM_ENDIO_REQUEUE; | |
1569 | } else { | |
1570 | dm_report_EIO(m); | |
1571 | *error = BLK_STS_IOERR; | |
1572 | } | |
14ef1e48 | 1573 | goto done; |
18a482f5 | 1574 | } |
76e33fe4 MS |
1575 | |
1576 | /* Queue for the daemon to resubmit */ | |
bf661be1 | 1577 | dm_bio_restore(get_bio_details_from_bio(clone), clone); |
76e33fe4 MS |
1578 | |
1579 | spin_lock_irqsave(&m->lock, flags); | |
1580 | bio_list_add(&m->queued_bios, clone); | |
1581 | spin_unlock_irqrestore(&m->lock, flags); | |
1582 | if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) | |
1583 | queue_work(kmultipathd, &m->process_queued_bios); | |
1584 | ||
1be56909 | 1585 | r = DM_ENDIO_INCOMPLETE; |
14ef1e48 | 1586 | done: |
76e33fe4 | 1587 | if (pgpath) { |
14ef1e48 CH |
1588 | struct path_selector *ps = &pgpath->pg->ps; |
1589 | ||
76e33fe4 MS |
1590 | if (ps->type->end_io) |
1591 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes); | |
1592 | } | |
1593 | ||
1be56909 | 1594 | return r; |
76e33fe4 MS |
1595 | } |
1596 | ||
1da177e4 LT |
1597 | /* |
1598 | * Suspend can't complete until all the I/O is processed so if | |
436d4108 AK |
1599 | * the last path fails we must error any remaining I/O. |
1600 | * Note that if the freeze_bdev fails while suspending, the | |
1601 | * queue_if_no_path state is lost - userspace should reset it. | |
1da177e4 LT |
1602 | */ |
1603 | static void multipath_presuspend(struct dm_target *ti) | |
1604 | { | |
7943bd6d | 1605 | struct multipath *m = ti->private; |
1da177e4 | 1606 | |
be7d31cc | 1607 | queue_if_no_path(m, false, true); |
1da177e4 LT |
1608 | } |
1609 | ||
6df400ab KU |
1610 | static void multipath_postsuspend(struct dm_target *ti) |
1611 | { | |
6380f26f MA |
1612 | struct multipath *m = ti->private; |
1613 | ||
1614 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1615 | flush_multipath_work(m); |
6380f26f | 1616 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1617 | } |
1618 | ||
436d4108 AK |
1619 | /* |
1620 | * Restore the queue_if_no_path setting. | |
1621 | */ | |
1da177e4 LT |
1622 | static void multipath_resume(struct dm_target *ti) |
1623 | { | |
7943bd6d | 1624 | struct multipath *m = ti->private; |
1814f2e3 | 1625 | unsigned long flags; |
1da177e4 | 1626 | |
1814f2e3 | 1627 | spin_lock_irqsave(&m->lock, flags); |
5307e2ad LW |
1628 | assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, |
1629 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)); | |
1814f2e3 | 1630 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1631 | } |
1632 | ||
1633 | /* | |
1634 | * Info output has the following format: | |
1635 | * num_multipath_feature_args [multipath_feature_args]* | |
1636 | * num_handler_status_args [handler_status_args]* | |
1637 | * num_groups init_group_number | |
1638 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1639 | * num_paths num_selector_args | |
1640 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1641 | * | |
1642 | * Table output has the following format (identical to the constructor string): | |
1643 | * num_feature_args [features_args]* | |
1644 | * num_handler_args hw_handler [hw_handler_args]* | |
1645 | * num_groups init_group_number | |
1646 | * [priority selector-name num_ps_args [ps_args]* | |
1647 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1648 | */ | |
fd7c092e MP |
1649 | static void multipath_status(struct dm_target *ti, status_type_t type, |
1650 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
1651 | { |
1652 | int sz = 0; | |
1653 | unsigned long flags; | |
7943bd6d | 1654 | struct multipath *m = ti->private; |
1da177e4 LT |
1655 | struct priority_group *pg; |
1656 | struct pgpath *p; | |
1657 | unsigned pg_num; | |
1658 | char state; | |
1659 | ||
1660 | spin_lock_irqsave(&m->lock, flags); | |
1661 | ||
1662 | /* Features */ | |
1663 | if (type == STATUSTYPE_INFO) | |
91e968aa MS |
1664 | DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags), |
1665 | atomic_read(&m->pg_init_count)); | |
c9e45581 | 1666 | else { |
518257b1 | 1667 | DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) + |
4e2d19e4 | 1668 | (m->pg_init_retries > 0) * 2 + |
a58a935d | 1669 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
e83068a5 MS |
1670 | test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) + |
1671 | (m->queue_mode != DM_TYPE_REQUEST_BASED) * 2); | |
1672 | ||
518257b1 | 1673 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
c9e45581 DW |
1674 | DMEMIT("queue_if_no_path "); |
1675 | if (m->pg_init_retries) | |
1676 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
4e2d19e4 CS |
1677 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
1678 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); | |
518257b1 | 1679 | if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) |
a58a935d | 1680 | DMEMIT("retain_attached_hw_handler "); |
e83068a5 MS |
1681 | if (m->queue_mode != DM_TYPE_REQUEST_BASED) { |
1682 | switch(m->queue_mode) { | |
1683 | case DM_TYPE_BIO_BASED: | |
1684 | DMEMIT("queue_mode bio "); | |
1685 | break; | |
1686 | case DM_TYPE_MQ_REQUEST_BASED: | |
1687 | DMEMIT("queue_mode mq "); | |
1688 | break; | |
7e0d574f BVA |
1689 | default: |
1690 | WARN_ON_ONCE(true); | |
1691 | break; | |
e83068a5 MS |
1692 | } |
1693 | } | |
c9e45581 | 1694 | } |
1da177e4 | 1695 | |
cfae5c9b | 1696 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1697 | DMEMIT("0 "); |
1698 | else | |
cfae5c9b | 1699 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1700 | |
1701 | DMEMIT("%u ", m->nr_priority_groups); | |
1702 | ||
1703 | if (m->next_pg) | |
1704 | pg_num = m->next_pg->pg_num; | |
1705 | else if (m->current_pg) | |
1706 | pg_num = m->current_pg->pg_num; | |
1707 | else | |
a490a07a | 1708 | pg_num = (m->nr_priority_groups ? 1 : 0); |
1da177e4 LT |
1709 | |
1710 | DMEMIT("%u ", pg_num); | |
1711 | ||
1712 | switch (type) { | |
1713 | case STATUSTYPE_INFO: | |
1714 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1715 | if (pg->bypassed) | |
1716 | state = 'D'; /* Disabled */ | |
1717 | else if (pg == m->current_pg) | |
1718 | state = 'A'; /* Currently Active */ | |
1719 | else | |
1720 | state = 'E'; /* Enabled */ | |
1721 | ||
1722 | DMEMIT("%c ", state); | |
1723 | ||
1724 | if (pg->ps.type->status) | |
1725 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1726 | result + sz, | |
1727 | maxlen - sz); | |
1728 | else | |
1729 | DMEMIT("0 "); | |
1730 | ||
1731 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1732 | pg->ps.type->info_args); | |
1733 | ||
1734 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1735 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1736 | p->is_active ? "A" : "F", |
1da177e4 LT |
1737 | p->fail_count); |
1738 | if (pg->ps.type->status) | |
1739 | sz += pg->ps.type->status(&pg->ps, | |
1740 | &p->path, type, result + sz, | |
1741 | maxlen - sz); | |
1742 | } | |
1743 | } | |
1744 | break; | |
1745 | ||
1746 | case STATUSTYPE_TABLE: | |
1747 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1748 | DMEMIT("%s ", pg->ps.type->name); | |
1749 | ||
1750 | if (pg->ps.type->status) | |
1751 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1752 | result + sz, | |
1753 | maxlen - sz); | |
1754 | else | |
1755 | DMEMIT("0 "); | |
1756 | ||
1757 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1758 | pg->ps.type->table_args); | |
1759 | ||
1760 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1761 | DMEMIT("%s ", p->path.dev->name); | |
1762 | if (pg->ps.type->status) | |
1763 | sz += pg->ps.type->status(&pg->ps, | |
1764 | &p->path, type, result + sz, | |
1765 | maxlen - sz); | |
1766 | } | |
1767 | } | |
1768 | break; | |
1769 | } | |
1770 | ||
1771 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
1772 | } |
1773 | ||
1774 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv) | |
1775 | { | |
6380f26f | 1776 | int r = -EINVAL; |
1da177e4 | 1777 | struct dm_dev *dev; |
7943bd6d | 1778 | struct multipath *m = ti->private; |
1da177e4 LT |
1779 | action_fn action; |
1780 | ||
6380f26f MA |
1781 | mutex_lock(&m->work_mutex); |
1782 | ||
c2f3d24b KU |
1783 | if (dm_suspended(ti)) { |
1784 | r = -EBUSY; | |
1785 | goto out; | |
1786 | } | |
1787 | ||
1da177e4 | 1788 | if (argc == 1) { |
498f0103 | 1789 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
be7d31cc | 1790 | r = queue_if_no_path(m, true, false); |
6380f26f | 1791 | goto out; |
498f0103 | 1792 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
be7d31cc | 1793 | r = queue_if_no_path(m, false, false); |
6380f26f MA |
1794 | goto out; |
1795 | } | |
1da177e4 LT |
1796 | } |
1797 | ||
6380f26f | 1798 | if (argc != 2) { |
a356e426 | 1799 | DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); |
6380f26f MA |
1800 | goto out; |
1801 | } | |
1da177e4 | 1802 | |
498f0103 | 1803 | if (!strcasecmp(argv[0], "disable_group")) { |
be7d31cc | 1804 | r = bypass_pg_num(m, argv[1], true); |
6380f26f | 1805 | goto out; |
498f0103 | 1806 | } else if (!strcasecmp(argv[0], "enable_group")) { |
be7d31cc | 1807 | r = bypass_pg_num(m, argv[1], false); |
6380f26f | 1808 | goto out; |
498f0103 | 1809 | } else if (!strcasecmp(argv[0], "switch_group")) { |
6380f26f MA |
1810 | r = switch_pg_num(m, argv[1]); |
1811 | goto out; | |
498f0103 | 1812 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
1da177e4 | 1813 | action = reinstate_path; |
498f0103 | 1814 | else if (!strcasecmp(argv[0], "fail_path")) |
1da177e4 | 1815 | action = fail_path; |
6380f26f | 1816 | else { |
a356e426 | 1817 | DMWARN("Unrecognised multipath message received: %s", argv[0]); |
6380f26f MA |
1818 | goto out; |
1819 | } | |
1da177e4 | 1820 | |
8215d6ec | 1821 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 1822 | if (r) { |
72d94861 | 1823 | DMWARN("message: error getting device %s", |
1da177e4 | 1824 | argv[1]); |
6380f26f | 1825 | goto out; |
1da177e4 LT |
1826 | } |
1827 | ||
1828 | r = action_dev(m, dev, action); | |
1829 | ||
1830 | dm_put_device(ti, dev); | |
1831 | ||
6380f26f MA |
1832 | out: |
1833 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 1834 | return r; |
1da177e4 LT |
1835 | } |
1836 | ||
e56f81e0 CH |
1837 | static int multipath_prepare_ioctl(struct dm_target *ti, |
1838 | struct block_device **bdev, fmode_t *mode) | |
9af4aa30 | 1839 | { |
35991652 | 1840 | struct multipath *m = ti->private; |
2da1610a | 1841 | struct pgpath *current_pgpath; |
35991652 MP |
1842 | int r; |
1843 | ||
506458ef | 1844 | current_pgpath = READ_ONCE(m->current_pgpath); |
2da1610a MS |
1845 | if (!current_pgpath) |
1846 | current_pgpath = choose_pgpath(m, 0); | |
9af4aa30 | 1847 | |
2da1610a | 1848 | if (current_pgpath) { |
518257b1 | 1849 | if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) { |
2da1610a MS |
1850 | *bdev = current_pgpath->path.dev->bdev; |
1851 | *mode = current_pgpath->path.dev->mode; | |
43e43c9e JN |
1852 | r = 0; |
1853 | } else { | |
1854 | /* pg_init has not started or completed */ | |
1855 | r = -ENOTCONN; | |
1856 | } | |
1857 | } else { | |
1858 | /* No path is available */ | |
518257b1 | 1859 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
43e43c9e JN |
1860 | r = -ENOTCONN; |
1861 | else | |
1862 | r = -EIO; | |
e90dae1f | 1863 | } |
9af4aa30 | 1864 | |
5bbbfdf6 | 1865 | if (r == -ENOTCONN) { |
506458ef | 1866 | if (!READ_ONCE(m->current_pg)) { |
3e9f1be1 | 1867 | /* Path status changed, redo selection */ |
2da1610a | 1868 | (void) choose_pgpath(m, 0); |
3e9f1be1 | 1869 | } |
518257b1 | 1870 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
2da1610a | 1871 | pg_init_all_paths(m); |
63d832c3 | 1872 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 1873 | process_queued_io_list(m); |
3e9f1be1 | 1874 | } |
35991652 | 1875 | |
e56f81e0 CH |
1876 | /* |
1877 | * Only pass ioctls through if the device sizes match exactly. | |
1878 | */ | |
1879 | if (!r && ti->len != i_size_read((*bdev)->bd_inode) >> SECTOR_SHIFT) | |
1880 | return 1; | |
1881 | return r; | |
9af4aa30 MB |
1882 | } |
1883 | ||
af4874e0 MS |
1884 | static int multipath_iterate_devices(struct dm_target *ti, |
1885 | iterate_devices_callout_fn fn, void *data) | |
1886 | { | |
1887 | struct multipath *m = ti->private; | |
1888 | struct priority_group *pg; | |
1889 | struct pgpath *p; | |
1890 | int ret = 0; | |
1891 | ||
1892 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1893 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 1894 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
1895 | if (ret) |
1896 | goto out; | |
1897 | } | |
1898 | } | |
1899 | ||
1900 | out: | |
1901 | return ret; | |
1902 | } | |
1903 | ||
9f54cec5 | 1904 | static int pgpath_busy(struct pgpath *pgpath) |
f40c67f0 KU |
1905 | { |
1906 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
1907 | ||
52b09914 | 1908 | return blk_lld_busy(q); |
f40c67f0 KU |
1909 | } |
1910 | ||
1911 | /* | |
1912 | * We return "busy", only when we can map I/Os but underlying devices | |
1913 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
1914 | * the underlying queue). | |
1915 | * In other words, if we want to kill I/Os or queue them inside us | |
1916 | * due to map unavailability, we don't return "busy". Otherwise, | |
1917 | * dm core won't give us the I/Os and we can't do what we want. | |
1918 | */ | |
1919 | static int multipath_busy(struct dm_target *ti) | |
1920 | { | |
be7d31cc | 1921 | bool busy = false, has_active = false; |
f40c67f0 | 1922 | struct multipath *m = ti->private; |
2da1610a | 1923 | struct priority_group *pg, *next_pg; |
f40c67f0 | 1924 | struct pgpath *pgpath; |
f40c67f0 | 1925 | |
b88efd43 MS |
1926 | /* pg_init in progress */ |
1927 | if (atomic_read(&m->pg_init_in_progress)) | |
2da1610a MS |
1928 | return true; |
1929 | ||
b88efd43 MS |
1930 | /* no paths available, for blk-mq: rely on IO mapping to delay requeue */ |
1931 | if (!atomic_read(&m->nr_valid_paths) && test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) | |
1932 | return (m->queue_mode != DM_TYPE_MQ_REQUEST_BASED); | |
1933 | ||
f40c67f0 | 1934 | /* Guess which priority_group will be used at next mapping time */ |
506458ef WD |
1935 | pg = READ_ONCE(m->current_pg); |
1936 | next_pg = READ_ONCE(m->next_pg); | |
1937 | if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg)) | |
2da1610a MS |
1938 | pg = next_pg; |
1939 | ||
1940 | if (!pg) { | |
f40c67f0 KU |
1941 | /* |
1942 | * We don't know which pg will be used at next mapping time. | |
2da1610a | 1943 | * We don't call choose_pgpath() here to avoid to trigger |
f40c67f0 KU |
1944 | * pg_init just by busy checking. |
1945 | * So we don't know whether underlying devices we will be using | |
1946 | * at next mapping time are busy or not. Just try mapping. | |
1947 | */ | |
2da1610a MS |
1948 | return busy; |
1949 | } | |
f40c67f0 KU |
1950 | |
1951 | /* | |
1952 | * If there is one non-busy active path at least, the path selector | |
1953 | * will be able to select it. So we consider such a pg as not busy. | |
1954 | */ | |
be7d31cc | 1955 | busy = true; |
2da1610a | 1956 | list_for_each_entry(pgpath, &pg->pgpaths, list) { |
f40c67f0 | 1957 | if (pgpath->is_active) { |
be7d31cc | 1958 | has_active = true; |
9f54cec5 | 1959 | if (!pgpath_busy(pgpath)) { |
be7d31cc | 1960 | busy = false; |
f40c67f0 KU |
1961 | break; |
1962 | } | |
1963 | } | |
2da1610a | 1964 | } |
f40c67f0 | 1965 | |
2da1610a | 1966 | if (!has_active) { |
f40c67f0 KU |
1967 | /* |
1968 | * No active path in this pg, so this pg won't be used and | |
1969 | * the current_pg will be changed at next mapping time. | |
1970 | * We need to try mapping to determine it. | |
1971 | */ | |
be7d31cc | 1972 | busy = false; |
2da1610a | 1973 | } |
f40c67f0 KU |
1974 | |
1975 | return busy; | |
1976 | } | |
1977 | ||
1da177e4 LT |
1978 | /*----------------------------------------------------------------- |
1979 | * Module setup | |
1980 | *---------------------------------------------------------------*/ | |
1981 | static struct target_type multipath_target = { | |
1982 | .name = "multipath", | |
91f86dfa SM |
1983 | .version = {1, 13, 0}, |
1984 | .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE | | |
1985 | DM_TARGET_PASSES_INTEGRITY, | |
1da177e4 LT |
1986 | .module = THIS_MODULE, |
1987 | .ctr = multipath_ctr, | |
1988 | .dtr = multipath_dtr, | |
e5863d9a MS |
1989 | .clone_and_map_rq = multipath_clone_and_map, |
1990 | .release_clone_rq = multipath_release_clone, | |
f40c67f0 | 1991 | .rq_end_io = multipath_end_io, |
76e33fe4 MS |
1992 | .map = multipath_map_bio, |
1993 | .end_io = multipath_end_io_bio, | |
1994 | .presuspend = multipath_presuspend, | |
1995 | .postsuspend = multipath_postsuspend, | |
1996 | .resume = multipath_resume, | |
1997 | .status = multipath_status, | |
1998 | .message = multipath_message, | |
1999 | .prepare_ioctl = multipath_prepare_ioctl, | |
2000 | .iterate_devices = multipath_iterate_devices, | |
2001 | .busy = multipath_busy, | |
2002 | }; | |
2003 | ||
1da177e4 LT |
2004 | static int __init dm_multipath_init(void) |
2005 | { | |
2006 | int r; | |
2007 | ||
4d4d66ab | 2008 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
c557308e | 2009 | if (!kmultipathd) { |
0cd33124 | 2010 | DMERR("failed to create workqueue kmpathd"); |
ff658e9c JT |
2011 | r = -ENOMEM; |
2012 | goto bad_alloc_kmultipathd; | |
c557308e AK |
2013 | } |
2014 | ||
bab7cfc7 CS |
2015 | /* |
2016 | * A separate workqueue is used to handle the device handlers | |
2017 | * to avoid overloading existing workqueue. Overloading the | |
2018 | * old workqueue would also create a bottleneck in the | |
2019 | * path of the storage hardware device activation. | |
2020 | */ | |
4d4d66ab TH |
2021 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
2022 | WQ_MEM_RECLAIM); | |
bab7cfc7 CS |
2023 | if (!kmpath_handlerd) { |
2024 | DMERR("failed to create workqueue kmpath_handlerd"); | |
ff658e9c JT |
2025 | r = -ENOMEM; |
2026 | goto bad_alloc_kmpath_handlerd; | |
bab7cfc7 CS |
2027 | } |
2028 | ||
7e6358d2 | 2029 | r = dm_register_target(&multipath_target); |
2030 | if (r < 0) { | |
2031 | DMERR("request-based register failed %d", r); | |
2032 | r = -EINVAL; | |
2033 | goto bad_register_target; | |
2034 | } | |
2035 | ||
ff658e9c JT |
2036 | return 0; |
2037 | ||
7e6358d2 | 2038 | bad_register_target: |
2039 | destroy_workqueue(kmpath_handlerd); | |
ff658e9c JT |
2040 | bad_alloc_kmpath_handlerd: |
2041 | destroy_workqueue(kmultipathd); | |
2042 | bad_alloc_kmultipathd: | |
1da177e4 LT |
2043 | return r; |
2044 | } | |
2045 | ||
2046 | static void __exit dm_multipath_exit(void) | |
2047 | { | |
bab7cfc7 | 2048 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
2049 | destroy_workqueue(kmultipathd); |
2050 | ||
10d3bd09 | 2051 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
2052 | } |
2053 | ||
1da177e4 LT |
2054 | module_init(dm_multipath_init); |
2055 | module_exit(dm_multipath_exit); | |
2056 | ||
2057 | MODULE_DESCRIPTION(DM_NAME " multipath target"); | |
2058 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
2059 | MODULE_LICENSE("GPL"); |