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 | ||
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> | |
be240ff5 | 23 | #include <linux/timer.h> |
1da177e4 | 24 | #include <linux/workqueue.h> |
35991652 | 25 | #include <linux/delay.h> |
cfae5c9b | 26 | #include <scsi/scsi_dh.h> |
60063497 | 27 | #include <linux/atomic.h> |
78ce23b5 | 28 | #include <linux/blk-mq.h> |
1da177e4 | 29 | |
72d94861 | 30 | #define DM_MSG_PREFIX "multipath" |
4e2d19e4 CS |
31 | #define DM_PG_INIT_DELAY_MSECS 2000 |
32 | #define DM_PG_INIT_DELAY_DEFAULT ((unsigned) -1) | |
be240ff5 AP |
33 | #define QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT 0 |
34 | ||
35 | static unsigned long queue_if_no_path_timeout_secs = QUEUE_IF_NO_PATH_TIMEOUT_DEFAULT; | |
1da177e4 LT |
36 | |
37 | /* Path properties */ | |
38 | struct pgpath { | |
39 | struct list_head list; | |
40 | ||
41 | struct priority_group *pg; /* Owning PG */ | |
42 | unsigned fail_count; /* Cumulative failure count */ | |
43 | ||
c922d5f7 | 44 | struct dm_path path; |
4e2d19e4 | 45 | struct delayed_work activate_path; |
be7d31cc MS |
46 | |
47 | bool is_active:1; /* Path status */ | |
1da177e4 LT |
48 | }; |
49 | ||
50 | #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path) | |
51 | ||
52 | /* | |
53 | * Paths are grouped into Priority Groups and numbered from 1 upwards. | |
54 | * Each has a path selector which controls which path gets used. | |
55 | */ | |
56 | struct priority_group { | |
57 | struct list_head list; | |
58 | ||
59 | struct multipath *m; /* Owning multipath instance */ | |
60 | struct path_selector ps; | |
61 | ||
62 | unsigned pg_num; /* Reference number */ | |
1da177e4 LT |
63 | unsigned nr_pgpaths; /* Number of paths in PG */ |
64 | struct list_head pgpaths; | |
be7d31cc MS |
65 | |
66 | bool bypassed:1; /* Temporarily bypass this PG? */ | |
1da177e4 LT |
67 | }; |
68 | ||
69 | /* Multipath context */ | |
70 | struct multipath { | |
848b8aef | 71 | unsigned long flags; /* Multipath state flags */ |
4e2d19e4 | 72 | |
1fbdd2b3 | 73 | spinlock_t lock; |
848b8aef | 74 | enum dm_queue_mode queue_mode; |
4e2d19e4 | 75 | |
1da177e4 LT |
76 | struct pgpath *current_pgpath; |
77 | struct priority_group *current_pg; | |
78 | struct priority_group *next_pg; /* Switch to this PG if set */ | |
1da177e4 | 79 | |
848b8aef MS |
80 | atomic_t nr_valid_paths; /* Total number of usable paths */ |
81 | unsigned nr_priority_groups; | |
82 | struct list_head priority_groups; | |
1fbdd2b3 | 83 | |
848b8aef MS |
84 | const char *hw_handler_name; |
85 | char *hw_handler_params; | |
86 | wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */ | |
c9e45581 | 87 | unsigned pg_init_retries; /* Number of times to retry pg_init */ |
4e2d19e4 | 88 | unsigned pg_init_delay_msecs; /* Number of msecs before pg_init retry */ |
91e968aa MS |
89 | atomic_t pg_init_in_progress; /* Only one pg_init allowed at once */ |
90 | atomic_t pg_init_count; /* Number of times pg_init called */ | |
91 | ||
6380f26f | 92 | struct mutex work_mutex; |
20800cb3 | 93 | struct work_struct trigger_event; |
848b8aef | 94 | struct dm_target *ti; |
76e33fe4 MS |
95 | |
96 | struct work_struct process_queued_bios; | |
97 | struct bio_list queued_bios; | |
be240ff5 AP |
98 | |
99 | struct timer_list nopath_timer; /* Timeout for queue_if_no_path */ | |
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); |
be240ff5 | 117 | static void queue_if_no_path_timeout_work(struct timer_list *t); |
1da177e4 | 118 | |
518257b1 MS |
119 | /*----------------------------------------------- |
120 | * Multipath state flags. | |
121 | *-----------------------------------------------*/ | |
122 | ||
123 | #define MPATHF_QUEUE_IO 0 /* Must we queue all I/O? */ | |
124 | #define MPATHF_QUEUE_IF_NO_PATH 1 /* Queue I/O if last path fails? */ | |
125 | #define MPATHF_SAVED_QUEUE_IF_NO_PATH 2 /* Saved state during suspension */ | |
126 | #define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3 /* If there's already a hw_handler present, don't change it. */ | |
127 | #define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */ | |
128 | #define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */ | |
129 | #define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */ | |
1da177e4 | 130 | |
374117ad MS |
131 | static bool mpath_double_check_test_bit(int MPATHF_bit, struct multipath *m) |
132 | { | |
133 | bool r = test_bit(MPATHF_bit, &m->flags); | |
134 | ||
135 | if (r) { | |
136 | unsigned long flags; | |
137 | spin_lock_irqsave(&m->lock, flags); | |
138 | r = test_bit(MPATHF_bit, &m->flags); | |
139 | spin_unlock_irqrestore(&m->lock, flags); | |
140 | } | |
141 | ||
142 | return r; | |
143 | } | |
144 | ||
1da177e4 LT |
145 | /*----------------------------------------------- |
146 | * Allocation routines | |
147 | *-----------------------------------------------*/ | |
148 | ||
149 | static struct pgpath *alloc_pgpath(void) | |
150 | { | |
e69fae56 | 151 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 152 | |
848b8aef MS |
153 | if (!pgpath) |
154 | return NULL; | |
155 | ||
156 | pgpath->is_active = true; | |
1da177e4 LT |
157 | |
158 | return pgpath; | |
159 | } | |
160 | ||
028867ac | 161 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
162 | { |
163 | kfree(pgpath); | |
164 | } | |
165 | ||
166 | static struct priority_group *alloc_priority_group(void) | |
167 | { | |
168 | struct priority_group *pg; | |
169 | ||
e69fae56 | 170 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 171 | |
e69fae56 MM |
172 | if (pg) |
173 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
174 | |
175 | return pg; | |
176 | } | |
177 | ||
178 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
179 | { | |
180 | struct pgpath *pgpath, *tmp; | |
181 | ||
182 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
183 | list_del(&pgpath->list); | |
184 | dm_put_device(ti, pgpath->path.dev); | |
185 | free_pgpath(pgpath); | |
186 | } | |
187 | } | |
188 | ||
189 | static void free_priority_group(struct priority_group *pg, | |
190 | struct dm_target *ti) | |
191 | { | |
192 | struct path_selector *ps = &pg->ps; | |
193 | ||
194 | if (ps->type) { | |
195 | ps->type->destroy(ps); | |
196 | dm_put_path_selector(ps->type); | |
197 | } | |
198 | ||
199 | free_pgpaths(&pg->pgpaths, ti); | |
200 | kfree(pg); | |
201 | } | |
202 | ||
e83068a5 | 203 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
204 | { |
205 | struct multipath *m; | |
206 | ||
e69fae56 | 207 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 208 | if (m) { |
1da177e4 LT |
209 | INIT_LIST_HEAD(&m->priority_groups); |
210 | spin_lock_init(&m->lock); | |
91e968aa | 211 | atomic_set(&m->nr_valid_paths, 0); |
c4028958 | 212 | INIT_WORK(&m->trigger_event, trigger_event); |
6380f26f | 213 | mutex_init(&m->work_mutex); |
8637a6bf | 214 | |
e83068a5 | 215 | m->queue_mode = DM_TYPE_NONE; |
76e33fe4 | 216 | |
28f16c20 MM |
217 | m->ti = ti; |
218 | ti->private = m; | |
be240ff5 AP |
219 | |
220 | timer_setup(&m->nopath_timer, queue_if_no_path_timeout_work, 0); | |
1da177e4 LT |
221 | } |
222 | ||
223 | return m; | |
224 | } | |
225 | ||
e83068a5 MS |
226 | static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m) |
227 | { | |
228 | if (m->queue_mode == DM_TYPE_NONE) { | |
953923c0 | 229 | m->queue_mode = DM_TYPE_REQUEST_BASED; |
8d47e659 | 230 | } else if (m->queue_mode == DM_TYPE_BIO_BASED) { |
e83068a5 | 231 | INIT_WORK(&m->process_queued_bios, process_queued_bios); |
8d47e659 MS |
232 | /* |
233 | * bio-based doesn't support any direct scsi_dh management; | |
234 | * it just discovers if a scsi_dh is attached. | |
235 | */ | |
236 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); | |
e83068a5 MS |
237 | } |
238 | ||
239 | dm_table_set_type(ti->table, m->queue_mode); | |
240 | ||
c3736674 MS |
241 | /* |
242 | * Init fields that are only used when a scsi_dh is attached | |
243 | * - must do this unconditionally (really doesn't hurt non-SCSI uses) | |
244 | */ | |
245 | set_bit(MPATHF_QUEUE_IO, &m->flags); | |
246 | atomic_set(&m->pg_init_in_progress, 0); | |
247 | atomic_set(&m->pg_init_count, 0); | |
248 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; | |
249 | init_waitqueue_head(&m->pg_init_wait); | |
250 | ||
e83068a5 MS |
251 | return 0; |
252 | } | |
253 | ||
1da177e4 LT |
254 | static void free_multipath(struct multipath *m) |
255 | { | |
256 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
257 | |
258 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
259 | list_del(&pg->list); | |
260 | free_priority_group(pg, m->ti); | |
261 | } | |
262 | ||
cfae5c9b | 263 | kfree(m->hw_handler_name); |
2bfd2e13 | 264 | kfree(m->hw_handler_params); |
d5ffebdd | 265 | mutex_destroy(&m->work_mutex); |
1da177e4 LT |
266 | kfree(m); |
267 | } | |
268 | ||
2eff1924 MS |
269 | static struct dm_mpath_io *get_mpio(union map_info *info) |
270 | { | |
271 | return info->ptr; | |
272 | } | |
273 | ||
bf661be1 MS |
274 | static size_t multipath_per_bio_data_size(void) |
275 | { | |
276 | return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details); | |
277 | } | |
278 | ||
76e33fe4 MS |
279 | static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio) |
280 | { | |
bf661be1 | 281 | return dm_per_bio_data(bio, multipath_per_bio_data_size()); |
76e33fe4 MS |
282 | } |
283 | ||
d07a241d | 284 | static struct dm_bio_details *get_bio_details_from_mpio(struct dm_mpath_io *mpio) |
76e33fe4 | 285 | { |
bf661be1 | 286 | /* dm_bio_details is immediately after the dm_mpath_io in bio's per-bio-data */ |
bf661be1 | 287 | void *bio_details = mpio + 1; |
bf661be1 MS |
288 | return bio_details; |
289 | } | |
290 | ||
63f6e6fd | 291 | static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p) |
bf661be1 MS |
292 | { |
293 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); | |
d07a241d | 294 | struct dm_bio_details *bio_details = get_bio_details_from_mpio(mpio); |
76e33fe4 | 295 | |
d0442f80 MS |
296 | mpio->nr_bytes = bio->bi_iter.bi_size; |
297 | mpio->pgpath = NULL; | |
298 | *mpio_p = mpio; | |
76e33fe4 | 299 | |
d0442f80 | 300 | dm_bio_record(bio_details, bio); |
76e33fe4 MS |
301 | } |
302 | ||
1da177e4 LT |
303 | /*----------------------------------------------- |
304 | * Path selection | |
305 | *-----------------------------------------------*/ | |
306 | ||
3e9f1be1 | 307 | static int __pg_init_all_paths(struct multipath *m) |
fb612642 KU |
308 | { |
309 | struct pgpath *pgpath; | |
4e2d19e4 | 310 | unsigned long pg_init_delay = 0; |
fb612642 | 311 | |
b194679f BVA |
312 | lockdep_assert_held(&m->lock); |
313 | ||
91e968aa | 314 | if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) |
3e9f1be1 | 315 | return 0; |
17f4ff45 | 316 | |
91e968aa | 317 | atomic_inc(&m->pg_init_count); |
518257b1 | 318 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
3e9f1be1 HR |
319 | |
320 | /* Check here to reset pg_init_required */ | |
321 | if (!m->current_pg) | |
322 | return 0; | |
323 | ||
518257b1 | 324 | if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags)) |
4e2d19e4 CS |
325 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? |
326 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); | |
fb612642 KU |
327 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
328 | /* Skip failed paths */ | |
329 | if (!pgpath->is_active) | |
330 | continue; | |
4e2d19e4 CS |
331 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
332 | pg_init_delay)) | |
91e968aa | 333 | atomic_inc(&m->pg_init_in_progress); |
fb612642 | 334 | } |
91e968aa | 335 | return atomic_read(&m->pg_init_in_progress); |
fb612642 KU |
336 | } |
337 | ||
c1d7ecf7 | 338 | static int pg_init_all_paths(struct multipath *m) |
1da177e4 | 339 | { |
c1d7ecf7 | 340 | int ret; |
2da1610a MS |
341 | unsigned long flags; |
342 | ||
343 | spin_lock_irqsave(&m->lock, flags); | |
c1d7ecf7 | 344 | ret = __pg_init_all_paths(m); |
2da1610a | 345 | spin_unlock_irqrestore(&m->lock, flags); |
c1d7ecf7 BVA |
346 | |
347 | return ret; | |
2da1610a MS |
348 | } |
349 | ||
350 | static void __switch_pg(struct multipath *m, struct priority_group *pg) | |
351 | { | |
69cea0d4 MS |
352 | lockdep_assert_held(&m->lock); |
353 | ||
2da1610a | 354 | m->current_pg = pg; |
1da177e4 LT |
355 | |
356 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 357 | if (m->hw_handler_name) { |
518257b1 MS |
358 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
359 | set_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 360 | } else { |
518257b1 MS |
361 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
362 | clear_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 363 | } |
c9e45581 | 364 | |
91e968aa | 365 | atomic_set(&m->pg_init_count, 0); |
1da177e4 LT |
366 | } |
367 | ||
2da1610a MS |
368 | static struct pgpath *choose_path_in_pg(struct multipath *m, |
369 | struct priority_group *pg, | |
370 | size_t nr_bytes) | |
1da177e4 | 371 | { |
2da1610a | 372 | unsigned long flags; |
c922d5f7 | 373 | struct dm_path *path; |
2da1610a | 374 | struct pgpath *pgpath; |
1da177e4 | 375 | |
90a4323c | 376 | path = pg->ps.type->select_path(&pg->ps, nr_bytes); |
1da177e4 | 377 | if (!path) |
2da1610a | 378 | return ERR_PTR(-ENXIO); |
1da177e4 | 379 | |
2da1610a | 380 | pgpath = path_to_pgpath(path); |
1da177e4 | 381 | |
506458ef | 382 | if (unlikely(READ_ONCE(m->current_pg) != pg)) { |
2da1610a MS |
383 | /* Only update current_pgpath if pg changed */ |
384 | spin_lock_irqsave(&m->lock, flags); | |
385 | m->current_pgpath = pgpath; | |
386 | __switch_pg(m, pg); | |
387 | spin_unlock_irqrestore(&m->lock, flags); | |
388 | } | |
1da177e4 | 389 | |
2da1610a | 390 | return pgpath; |
1da177e4 LT |
391 | } |
392 | ||
2da1610a | 393 | static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 | 394 | { |
2da1610a | 395 | unsigned long flags; |
1da177e4 | 396 | struct priority_group *pg; |
2da1610a | 397 | struct pgpath *pgpath; |
d19a55cc | 398 | unsigned bypassed = 1; |
1da177e4 | 399 | |
91e968aa | 400 | if (!atomic_read(&m->nr_valid_paths)) { |
69cea0d4 | 401 | spin_lock_irqsave(&m->lock, flags); |
8d47e659 | 402 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
69cea0d4 | 403 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 404 | goto failed; |
1f271972 | 405 | } |
1da177e4 LT |
406 | |
407 | /* Were we instructed to switch PG? */ | |
506458ef | 408 | if (READ_ONCE(m->next_pg)) { |
2da1610a | 409 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 410 | pg = m->next_pg; |
2da1610a MS |
411 | if (!pg) { |
412 | spin_unlock_irqrestore(&m->lock, flags); | |
413 | goto check_current_pg; | |
414 | } | |
1da177e4 | 415 | m->next_pg = NULL; |
2da1610a MS |
416 | spin_unlock_irqrestore(&m->lock, flags); |
417 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
418 | if (!IS_ERR_OR_NULL(pgpath)) | |
419 | return pgpath; | |
1da177e4 LT |
420 | } |
421 | ||
422 | /* Don't change PG until it has no remaining paths */ | |
2da1610a | 423 | check_current_pg: |
506458ef | 424 | pg = READ_ONCE(m->current_pg); |
2da1610a MS |
425 | if (pg) { |
426 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
427 | if (!IS_ERR_OR_NULL(pgpath)) | |
428 | return pgpath; | |
429 | } | |
1da177e4 LT |
430 | |
431 | /* | |
432 | * Loop through priority groups until we find a valid path. | |
433 | * First time we skip PGs marked 'bypassed'. | |
f220fd4e MC |
434 | * Second time we only try the ones we skipped, but set |
435 | * pg_init_delay_retry so we do not hammer controllers. | |
1da177e4 LT |
436 | */ |
437 | do { | |
438 | list_for_each_entry(pg, &m->priority_groups, list) { | |
d19a55cc | 439 | if (pg->bypassed == !!bypassed) |
1da177e4 | 440 | continue; |
2da1610a MS |
441 | pgpath = choose_path_in_pg(m, pg, nr_bytes); |
442 | if (!IS_ERR_OR_NULL(pgpath)) { | |
69cea0d4 MS |
443 | if (!bypassed) { |
444 | spin_lock_irqsave(&m->lock, flags); | |
518257b1 | 445 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); |
69cea0d4 MS |
446 | spin_unlock_irqrestore(&m->lock, flags); |
447 | } | |
2da1610a | 448 | return pgpath; |
f220fd4e | 449 | } |
1da177e4 LT |
450 | } |
451 | } while (bypassed--); | |
452 | ||
453 | failed: | |
2da1610a | 454 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
455 | m->current_pgpath = NULL; |
456 | m->current_pg = NULL; | |
2da1610a MS |
457 | spin_unlock_irqrestore(&m->lock, flags); |
458 | ||
459 | return NULL; | |
1da177e4 LT |
460 | } |
461 | ||
45e15720 | 462 | /* |
ac75b09f | 463 | * dm_report_EIO() is a macro instead of a function to make pr_debug_ratelimited() |
86331f39 BVA |
464 | * report the function name and line number of the function from which |
465 | * it has been invoked. | |
45e15720 | 466 | */ |
86331f39 | 467 | #define dm_report_EIO(m) \ |
18a482f5 | 468 | do { \ |
ac75b09f | 469 | DMDEBUG_LIMIT("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d", \ |
d4a512ed | 470 | dm_table_device_name((m)->ti->table), \ |
ac75b09f MS |
471 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags), \ |
472 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \ | |
473 | dm_noflush_suspending((m)->ti)); \ | |
18a482f5 | 474 | } while (0) |
45e15720 | 475 | |
c1fd0abe MS |
476 | /* |
477 | * Check whether bios must be queued in the device-mapper core rather | |
478 | * than here in the target. | |
c1fd0abe | 479 | */ |
a862e4e2 | 480 | static bool __must_push_back(struct multipath *m) |
c1fd0abe | 481 | { |
a862e4e2 | 482 | return dm_noflush_suspending(m->ti); |
c1fd0abe MS |
483 | } |
484 | ||
c1fd0abe MS |
485 | static bool must_push_back_rq(struct multipath *m) |
486 | { | |
73265f3f MS |
487 | unsigned long flags; |
488 | bool ret; | |
489 | ||
490 | spin_lock_irqsave(&m->lock, flags); | |
491 | ret = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || __must_push_back(m)); | |
492 | spin_unlock_irqrestore(&m->lock, flags); | |
493 | ||
494 | return ret; | |
c1fd0abe MS |
495 | } |
496 | ||
36fcffcc | 497 | /* |
76e33fe4 | 498 | * Map cloned requests (request-based multipath) |
36fcffcc | 499 | */ |
eb8db831 CH |
500 | static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, |
501 | union map_info *map_context, | |
502 | struct request **__clone) | |
1da177e4 | 503 | { |
7943bd6d | 504 | struct multipath *m = ti->private; |
eb8db831 | 505 | size_t nr_bytes = blk_rq_bytes(rq); |
1da177e4 | 506 | struct pgpath *pgpath; |
f40c67f0 | 507 | struct block_device *bdev; |
eb8db831 | 508 | struct dm_mpath_io *mpio = get_mpio(map_context); |
7083abbb | 509 | struct request_queue *q; |
eb8db831 | 510 | struct request *clone; |
1da177e4 | 511 | |
1da177e4 | 512 | /* Do we need to select a new pgpath? */ |
506458ef | 513 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 514 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
2da1610a | 515 | pgpath = choose_pgpath(m, nr_bytes); |
1da177e4 | 516 | |
9bf59a61 | 517 | if (!pgpath) { |
c1fd0abe | 518 | if (must_push_back_rq(m)) |
b88efd43 | 519 | return DM_MAPIO_DELAY_REQUEUE; |
18a482f5 | 520 | dm_report_EIO(m); /* Failed */ |
f98e0eb6 | 521 | return DM_MAPIO_KILL; |
374117ad MS |
522 | } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) || |
523 | mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) { | |
459b5401 ML |
524 | pg_init_all_paths(m); |
525 | return DM_MAPIO_DELAY_REQUEUE; | |
9bf59a61 | 526 | } |
6afbc01d | 527 | |
2eb6e1e3 KB |
528 | mpio->pgpath = pgpath; |
529 | mpio->nr_bytes = nr_bytes; | |
530 | ||
9bf59a61 | 531 | bdev = pgpath->path.dev->bdev; |
7083abbb | 532 | q = bdev_get_queue(bdev); |
0bf6d96c | 533 | clone = blk_mq_alloc_request(q, rq->cmd_flags | REQ_NOMERGE, |
ff005a06 | 534 | BLK_MQ_REQ_NOWAIT); |
eb8db831 CH |
535 | if (IS_ERR(clone)) { |
536 | /* EBUSY, ENODEV or EWOULDBLOCK: requeue */ | |
848b8aef | 537 | if (blk_queue_dying(q)) { |
7083abbb BVA |
538 | atomic_inc(&m->pg_init_in_progress); |
539 | activate_or_offline_path(pgpath); | |
050af08f | 540 | return DM_MAPIO_DELAY_REQUEUE; |
7083abbb | 541 | } |
050af08f ML |
542 | |
543 | /* | |
544 | * blk-mq's SCHED_RESTART can cover this requeue, so we | |
545 | * needn't deal with it by DELAY_REQUEUE. More importantly, | |
546 | * we have to return DM_MAPIO_REQUEUE so that blk-mq can | |
547 | * get the queue busy feedback (via BLK_STS_RESOURCE), | |
548 | * otherwise I/O merging can suffer. | |
549 | */ | |
6a23e05c | 550 | return DM_MAPIO_REQUEUE; |
e5863d9a | 551 | } |
eb8db831 | 552 | clone->bio = clone->biotail = NULL; |
eb8db831 CH |
553 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
554 | *__clone = clone; | |
e5863d9a | 555 | |
9bf59a61 MS |
556 | if (pgpath->pg->ps.type->start_io) |
557 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
558 | &pgpath->path, | |
559 | nr_bytes); | |
2eb6e1e3 | 560 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
561 | } |
562 | ||
5de719e3 YY |
563 | static void multipath_release_clone(struct request *clone, |
564 | union map_info *map_context) | |
e5863d9a | 565 | { |
5de719e3 YY |
566 | if (unlikely(map_context)) { |
567 | /* | |
568 | * non-NULL map_context means caller is still map | |
569 | * method; must undo multipath_clone_and_map() | |
570 | */ | |
571 | struct dm_mpath_io *mpio = get_mpio(map_context); | |
572 | struct pgpath *pgpath = mpio->pgpath; | |
573 | ||
574 | if (pgpath && pgpath->pg->ps.type->end_io) | |
575 | pgpath->pg->ps.type->end_io(&pgpath->pg->ps, | |
576 | &pgpath->path, | |
087615bf GKB |
577 | mpio->nr_bytes, |
578 | clone->io_start_time_ns); | |
5de719e3 YY |
579 | } |
580 | ||
0bf6d96c | 581 | blk_mq_free_request(clone); |
e5863d9a MS |
582 | } |
583 | ||
76e33fe4 MS |
584 | /* |
585 | * Map cloned bios (bio-based multipath) | |
586 | */ | |
0001ec56 | 587 | |
17213ec1 | 588 | static void __multipath_queue_bio(struct multipath *m, struct bio *bio) |
f45f1186 | 589 | { |
f45f1186 | 590 | /* Queue for the daemon to resubmit */ |
f45f1186 MS |
591 | bio_list_add(&m->queued_bios, bio); |
592 | if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) | |
593 | queue_work(kmultipathd, &m->process_queued_bios); | |
17213ec1 MS |
594 | } |
595 | ||
596 | static void multipath_queue_bio(struct multipath *m, struct bio *bio) | |
597 | { | |
598 | unsigned long flags; | |
599 | ||
600 | spin_lock_irqsave(&m->lock, flags); | |
601 | __multipath_queue_bio(m, bio); | |
f45f1186 MS |
602 | spin_unlock_irqrestore(&m->lock, flags); |
603 | } | |
604 | ||
0001ec56 | 605 | static struct pgpath *__map_bio(struct multipath *m, struct bio *bio) |
76e33fe4 | 606 | { |
76e33fe4 MS |
607 | struct pgpath *pgpath; |
608 | unsigned long flags; | |
76e33fe4 MS |
609 | |
610 | /* Do we need to select a new pgpath? */ | |
506458ef | 611 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 612 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
0001ec56 | 613 | pgpath = choose_pgpath(m, bio->bi_iter.bi_size); |
76e33fe4 | 614 | |
17213ec1 | 615 | if (!pgpath) { |
76e33fe4 | 616 | spin_lock_irqsave(&m->lock, flags); |
17213ec1 MS |
617 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { |
618 | __multipath_queue_bio(m, bio); | |
619 | pgpath = ERR_PTR(-EAGAIN); | |
620 | } | |
76e33fe4 | 621 | spin_unlock_irqrestore(&m->lock, flags); |
848b8aef | 622 | |
374117ad MS |
623 | } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) || |
624 | mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) { | |
f45f1186 | 625 | multipath_queue_bio(m, bio); |
17213ec1 | 626 | pg_init_all_paths(m); |
0001ec56 | 627 | return ERR_PTR(-EAGAIN); |
76e33fe4 MS |
628 | } |
629 | ||
0001ec56 MS |
630 | return pgpath; |
631 | } | |
632 | ||
0001ec56 MS |
633 | static int __multipath_map_bio(struct multipath *m, struct bio *bio, |
634 | struct dm_mpath_io *mpio) | |
635 | { | |
dbaf971c | 636 | struct pgpath *pgpath = __map_bio(m, bio); |
848b8aef | 637 | |
0001ec56 | 638 | if (IS_ERR(pgpath)) |
76e33fe4 | 639 | return DM_MAPIO_SUBMITTED; |
76e33fe4 MS |
640 | |
641 | if (!pgpath) { | |
a862e4e2 | 642 | if (__must_push_back(m)) |
ca5beb76 | 643 | return DM_MAPIO_REQUEUE; |
18a482f5 | 644 | dm_report_EIO(m); |
846785e6 | 645 | return DM_MAPIO_KILL; |
76e33fe4 MS |
646 | } |
647 | ||
648 | mpio->pgpath = pgpath; | |
76e33fe4 | 649 | |
4e4cbee9 | 650 | bio->bi_status = 0; |
74d46992 | 651 | bio_set_dev(bio, pgpath->path.dev->bdev); |
1eff9d32 | 652 | bio->bi_opf |= REQ_FAILFAST_TRANSPORT; |
76e33fe4 MS |
653 | |
654 | if (pgpath->pg->ps.type->start_io) | |
655 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
656 | &pgpath->path, | |
d0442f80 | 657 | mpio->nr_bytes); |
76e33fe4 MS |
658 | return DM_MAPIO_REMAPPED; |
659 | } | |
660 | ||
661 | static int multipath_map_bio(struct dm_target *ti, struct bio *bio) | |
662 | { | |
663 | struct multipath *m = ti->private; | |
bf661be1 MS |
664 | struct dm_mpath_io *mpio = NULL; |
665 | ||
63f6e6fd | 666 | multipath_init_per_bio_data(bio, &mpio); |
76e33fe4 MS |
667 | return __multipath_map_bio(m, bio, mpio); |
668 | } | |
669 | ||
7e48c768 | 670 | static void process_queued_io_list(struct multipath *m) |
76e33fe4 | 671 | { |
953923c0 | 672 | if (m->queue_mode == DM_TYPE_REQUEST_BASED) |
7e48c768 | 673 | dm_mq_kick_requeue_list(dm_table_get_md(m->ti->table)); |
8d47e659 | 674 | else if (m->queue_mode == DM_TYPE_BIO_BASED) |
76e33fe4 MS |
675 | queue_work(kmultipathd, &m->process_queued_bios); |
676 | } | |
677 | ||
678 | static void process_queued_bios(struct work_struct *work) | |
679 | { | |
680 | int r; | |
681 | unsigned long flags; | |
682 | struct bio *bio; | |
683 | struct bio_list bios; | |
684 | struct blk_plug plug; | |
685 | struct multipath *m = | |
686 | container_of(work, struct multipath, process_queued_bios); | |
687 | ||
688 | bio_list_init(&bios); | |
689 | ||
690 | spin_lock_irqsave(&m->lock, flags); | |
691 | ||
692 | if (bio_list_empty(&m->queued_bios)) { | |
693 | spin_unlock_irqrestore(&m->lock, flags); | |
694 | return; | |
695 | } | |
696 | ||
697 | bio_list_merge(&bios, &m->queued_bios); | |
698 | bio_list_init(&m->queued_bios); | |
699 | ||
700 | spin_unlock_irqrestore(&m->lock, flags); | |
701 | ||
702 | blk_start_plug(&plug); | |
703 | while ((bio = bio_list_pop(&bios))) { | |
1836df08 MS |
704 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); |
705 | dm_bio_restore(get_bio_details_from_mpio(mpio), bio); | |
706 | r = __multipath_map_bio(m, bio, mpio); | |
846785e6 CH |
707 | switch (r) { |
708 | case DM_MAPIO_KILL: | |
4e4cbee9 CH |
709 | bio->bi_status = BLK_STS_IOERR; |
710 | bio_endio(bio); | |
047385b3 | 711 | break; |
846785e6 | 712 | case DM_MAPIO_REQUEUE: |
4e4cbee9 | 713 | bio->bi_status = BLK_STS_DM_REQUEUE; |
76e33fe4 | 714 | bio_endio(bio); |
846785e6 CH |
715 | break; |
716 | case DM_MAPIO_REMAPPED: | |
ed00aabd | 717 | submit_bio_noacct(bio); |
846785e6 | 718 | break; |
8192a0cd | 719 | case DM_MAPIO_SUBMITTED: |
9157c8d3 BVA |
720 | break; |
721 | default: | |
722 | WARN_ONCE(true, "__multipath_map_bio() returned %d\n", r); | |
846785e6 | 723 | } |
76e33fe4 MS |
724 | } |
725 | blk_finish_plug(&plug); | |
726 | } | |
727 | ||
1da177e4 LT |
728 | /* |
729 | * If we run out of usable paths, should we queue I/O or error it? | |
730 | */ | |
be7d31cc | 731 | static int queue_if_no_path(struct multipath *m, bool queue_if_no_path, |
4c3f4838 | 732 | bool save_old_value, const char *caller) |
1da177e4 LT |
733 | { |
734 | unsigned long flags; | |
553ec94c | 735 | bool queue_if_no_path_bit, saved_queue_if_no_path_bit; |
d4a512ed | 736 | const char *dm_dev_name = dm_table_device_name(m->ti->table); |
4c3f4838 MS |
737 | |
738 | DMDEBUG("%s: %s caller=%s queue_if_no_path=%d save_old_value=%d", | |
739 | dm_dev_name, __func__, caller, queue_if_no_path, save_old_value); | |
1da177e4 LT |
740 | |
741 | spin_lock_irqsave(&m->lock, flags); | |
553ec94c MS |
742 | |
743 | queue_if_no_path_bit = test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); | |
744 | saved_queue_if_no_path_bit = test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
745 | ||
746 | if (save_old_value) { | |
747 | if (unlikely(!queue_if_no_path_bit && saved_queue_if_no_path_bit)) { | |
748 | DMERR("%s: QIFNP disabled but saved as enabled, saving again loses state, not saving!", | |
4c3f4838 | 749 | dm_dev_name); |
553ec94c MS |
750 | } else |
751 | assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path_bit); | |
752 | } else if (!queue_if_no_path && saved_queue_if_no_path_bit) { | |
753 | /* due to "fail_if_no_path" message, need to honor it. */ | |
754 | clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
755 | } | |
c1fd0abe | 756 | assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path); |
553ec94c | 757 | |
4c3f4838 MS |
758 | DMDEBUG("%s: after %s changes; QIFNP = %d; SQIFNP = %d; DNFS = %d", |
759 | dm_dev_name, __func__, | |
760 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags), | |
761 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags), | |
762 | dm_noflush_suspending(m->ti)); | |
763 | ||
1da177e4 LT |
764 | spin_unlock_irqrestore(&m->lock, flags); |
765 | ||
76e33fe4 | 766 | if (!queue_if_no_path) { |
63d832c3 | 767 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 768 | process_queued_io_list(m); |
76e33fe4 | 769 | } |
63d832c3 | 770 | |
1da177e4 LT |
771 | return 0; |
772 | } | |
773 | ||
be240ff5 AP |
774 | /* |
775 | * If the queue_if_no_path timeout fires, turn off queue_if_no_path and | |
776 | * process any queued I/O. | |
777 | */ | |
778 | static void queue_if_no_path_timeout_work(struct timer_list *t) | |
779 | { | |
780 | struct multipath *m = from_timer(m, t, nopath_timer); | |
be240ff5 | 781 | |
d4a512ed MS |
782 | DMWARN("queue_if_no_path timeout on %s, failing queued IO", |
783 | dm_table_device_name(m->ti->table)); | |
4c3f4838 | 784 | queue_if_no_path(m, false, false, __func__); |
be240ff5 AP |
785 | } |
786 | ||
787 | /* | |
788 | * Enable the queue_if_no_path timeout if necessary. | |
789 | * Called with m->lock held. | |
790 | */ | |
791 | static void enable_nopath_timeout(struct multipath *m) | |
792 | { | |
793 | unsigned long queue_if_no_path_timeout = | |
794 | READ_ONCE(queue_if_no_path_timeout_secs) * HZ; | |
795 | ||
796 | lockdep_assert_held(&m->lock); | |
797 | ||
798 | if (queue_if_no_path_timeout > 0 && | |
799 | atomic_read(&m->nr_valid_paths) == 0 && | |
800 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
801 | mod_timer(&m->nopath_timer, | |
802 | jiffies + queue_if_no_path_timeout); | |
803 | } | |
804 | } | |
805 | ||
806 | static void disable_nopath_timeout(struct multipath *m) | |
807 | { | |
808 | del_timer_sync(&m->nopath_timer); | |
809 | } | |
810 | ||
1da177e4 LT |
811 | /* |
812 | * An event is triggered whenever a path is taken out of use. | |
813 | * Includes path failure and PG bypass. | |
814 | */ | |
c4028958 | 815 | static void trigger_event(struct work_struct *work) |
1da177e4 | 816 | { |
c4028958 DH |
817 | struct multipath *m = |
818 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
819 | |
820 | dm_table_event(m->ti->table); | |
821 | } | |
822 | ||
823 | /*----------------------------------------------------------------- | |
824 | * Constructor/argument parsing: | |
825 | * <#multipath feature args> [<arg>]* | |
826 | * <#hw_handler args> [hw_handler [<arg>]*] | |
827 | * <#priority groups> | |
828 | * <initial priority group> | |
829 | * [<selector> <#selector args> [<arg>]* | |
830 | * <#paths> <#per-path selector args> | |
831 | * [<path> [<arg>]* ]+ ]+ | |
832 | *---------------------------------------------------------------*/ | |
498f0103 | 833 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
1da177e4 LT |
834 | struct dm_target *ti) |
835 | { | |
836 | int r; | |
837 | struct path_selector_type *pst; | |
838 | unsigned ps_argc; | |
839 | ||
5916a22b | 840 | static const struct dm_arg _args[] = { |
72d94861 | 841 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
842 | }; |
843 | ||
498f0103 | 844 | pst = dm_get_path_selector(dm_shift_arg(as)); |
1da177e4 | 845 | if (!pst) { |
72d94861 | 846 | ti->error = "unknown path selector type"; |
1da177e4 LT |
847 | return -EINVAL; |
848 | } | |
849 | ||
498f0103 | 850 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
371b2e34 MP |
851 | if (r) { |
852 | dm_put_path_selector(pst); | |
1da177e4 | 853 | return -EINVAL; |
371b2e34 | 854 | } |
1da177e4 LT |
855 | |
856 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
857 | if (r) { | |
858 | dm_put_path_selector(pst); | |
72d94861 | 859 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
860 | return r; |
861 | } | |
862 | ||
863 | pg->ps.type = pst; | |
498f0103 | 864 | dm_consume_args(as, ps_argc); |
1da177e4 LT |
865 | |
866 | return 0; | |
867 | } | |
868 | ||
e8f74a0f | 869 | static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, |
b592211c | 870 | const char **attached_handler_name, char **error) |
1da177e4 | 871 | { |
848b8aef | 872 | struct request_queue *q = bdev_get_queue(bdev); |
848b8aef | 873 | int r; |
a58a935d | 874 | |
374117ad | 875 | if (mpath_double_check_test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, m)) { |
1bab0de0 | 876 | retain: |
b592211c | 877 | if (*attached_handler_name) { |
54cd640d | 878 | /* |
879 | * Clear any hw_handler_params associated with a | |
880 | * handler that isn't already attached. | |
881 | */ | |
b592211c | 882 | if (m->hw_handler_name && strcmp(*attached_handler_name, m->hw_handler_name)) { |
54cd640d | 883 | kfree(m->hw_handler_params); |
884 | m->hw_handler_params = NULL; | |
885 | } | |
886 | ||
a58a935d MS |
887 | /* |
888 | * Reset hw_handler_name to match the attached handler | |
a58a935d MS |
889 | * |
890 | * NB. This modifies the table line to show the actual | |
891 | * handler instead of the original table passed in. | |
892 | */ | |
893 | kfree(m->hw_handler_name); | |
b592211c MS |
894 | m->hw_handler_name = *attached_handler_name; |
895 | *attached_handler_name = NULL; | |
a58a935d MS |
896 | } |
897 | } | |
a0cf7ea9 | 898 | |
a58a935d | 899 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
900 | r = scsi_dh_attach(q, m->hw_handler_name); |
901 | if (r == -EBUSY) { | |
168678d7 | 902 | DMINFO("retaining handler on device %pg", bdev); |
1bab0de0 CH |
903 | goto retain; |
904 | } | |
ae11b1b3 | 905 | if (r < 0) { |
848b8aef MS |
906 | *error = "error attaching hardware handler"; |
907 | return r; | |
ae11b1b3 | 908 | } |
2bfd2e13 CS |
909 | |
910 | if (m->hw_handler_params) { | |
911 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
912 | if (r < 0) { | |
848b8aef MS |
913 | *error = "unable to set hardware handler parameters"; |
914 | return r; | |
2bfd2e13 CS |
915 | } |
916 | } | |
ae11b1b3 HR |
917 | } |
918 | ||
848b8aef MS |
919 | return 0; |
920 | } | |
921 | ||
922 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, | |
923 | struct dm_target *ti) | |
924 | { | |
925 | int r; | |
926 | struct pgpath *p; | |
927 | struct multipath *m = ti->private; | |
e8f74a0f | 928 | struct request_queue *q; |
b592211c | 929 | const char *attached_handler_name = NULL; |
848b8aef MS |
930 | |
931 | /* we need at least a path arg */ | |
932 | if (as->argc < 1) { | |
933 | ti->error = "no device given"; | |
934 | return ERR_PTR(-EINVAL); | |
935 | } | |
936 | ||
937 | p = alloc_pgpath(); | |
938 | if (!p) | |
939 | return ERR_PTR(-ENOMEM); | |
940 | ||
941 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), | |
942 | &p->path.dev); | |
943 | if (r) { | |
944 | ti->error = "error getting device"; | |
945 | goto bad; | |
946 | } | |
947 | ||
e8f74a0f MS |
948 | q = bdev_get_queue(p->path.dev->bdev); |
949 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); | |
e457edf0 | 950 | if (attached_handler_name || m->hw_handler_name) { |
848b8aef | 951 | INIT_DELAYED_WORK(&p->activate_path, activate_path_work); |
b592211c | 952 | r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error); |
940bc471 | 953 | kfree(attached_handler_name); |
848b8aef MS |
954 | if (r) { |
955 | dm_put_device(ti, p->path.dev); | |
956 | goto bad; | |
957 | } | |
958 | } | |
959 | ||
1da177e4 LT |
960 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
961 | if (r) { | |
962 | dm_put_device(ti, p->path.dev); | |
963 | goto bad; | |
964 | } | |
965 | ||
966 | return p; | |
1da177e4 LT |
967 | bad: |
968 | free_pgpath(p); | |
01460f35 | 969 | return ERR_PTR(r); |
1da177e4 LT |
970 | } |
971 | ||
498f0103 | 972 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
28f16c20 | 973 | struct multipath *m) |
1da177e4 | 974 | { |
5916a22b | 975 | static const struct dm_arg _args[] = { |
72d94861 AK |
976 | {1, 1024, "invalid number of paths"}, |
977 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
978 | }; |
979 | ||
980 | int r; | |
498f0103 | 981 | unsigned i, nr_selector_args, nr_args; |
1da177e4 | 982 | struct priority_group *pg; |
28f16c20 | 983 | struct dm_target *ti = m->ti; |
1da177e4 LT |
984 | |
985 | if (as->argc < 2) { | |
986 | as->argc = 0; | |
01460f35 BM |
987 | ti->error = "not enough priority group arguments"; |
988 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
989 | } |
990 | ||
991 | pg = alloc_priority_group(); | |
992 | if (!pg) { | |
72d94861 | 993 | ti->error = "couldn't allocate priority group"; |
01460f35 | 994 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
995 | } |
996 | pg->m = m; | |
997 | ||
998 | r = parse_path_selector(as, pg, ti); | |
999 | if (r) | |
1000 | goto bad; | |
1001 | ||
1002 | /* | |
1003 | * read the paths | |
1004 | */ | |
498f0103 | 1005 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
1da177e4 LT |
1006 | if (r) |
1007 | goto bad; | |
1008 | ||
498f0103 | 1009 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
1da177e4 LT |
1010 | if (r) |
1011 | goto bad; | |
1012 | ||
498f0103 | 1013 | nr_args = 1 + nr_selector_args; |
1da177e4 LT |
1014 | for (i = 0; i < pg->nr_pgpaths; i++) { |
1015 | struct pgpath *pgpath; | |
498f0103 | 1016 | struct dm_arg_set path_args; |
1da177e4 | 1017 | |
498f0103 | 1018 | if (as->argc < nr_args) { |
148acff6 | 1019 | ti->error = "not enough path parameters"; |
6bbf79a1 | 1020 | r = -EINVAL; |
1da177e4 | 1021 | goto bad; |
148acff6 | 1022 | } |
1da177e4 | 1023 | |
498f0103 | 1024 | path_args.argc = nr_args; |
1da177e4 LT |
1025 | path_args.argv = as->argv; |
1026 | ||
1027 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
1028 | if (IS_ERR(pgpath)) { |
1029 | r = PTR_ERR(pgpath); | |
1da177e4 | 1030 | goto bad; |
01460f35 | 1031 | } |
1da177e4 LT |
1032 | |
1033 | pgpath->pg = pg; | |
1034 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
498f0103 | 1035 | dm_consume_args(as, nr_args); |
1da177e4 LT |
1036 | } |
1037 | ||
1038 | return pg; | |
1039 | ||
1040 | bad: | |
1041 | free_priority_group(pg, ti); | |
01460f35 | 1042 | return ERR_PTR(r); |
1da177e4 LT |
1043 | } |
1044 | ||
498f0103 | 1045 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
1da177e4 | 1046 | { |
1da177e4 | 1047 | unsigned hw_argc; |
2bfd2e13 | 1048 | int ret; |
28f16c20 | 1049 | struct dm_target *ti = m->ti; |
1da177e4 | 1050 | |
5916a22b | 1051 | static const struct dm_arg _args[] = { |
72d94861 | 1052 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
1053 | }; |
1054 | ||
498f0103 | 1055 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
1da177e4 LT |
1056 | return -EINVAL; |
1057 | ||
1058 | if (!hw_argc) | |
1059 | return 0; | |
1060 | ||
8d47e659 | 1061 | if (m->queue_mode == DM_TYPE_BIO_BASED) { |
76e33fe4 MS |
1062 | dm_consume_args(as, hw_argc); |
1063 | DMERR("bio-based multipath doesn't allow hardware handler args"); | |
1064 | return 0; | |
1065 | } | |
1066 | ||
498f0103 | 1067 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
f97dc421 | 1068 | if (!m->hw_handler_name) |
1069 | return -EINVAL; | |
14e98c5c | 1070 | |
2bfd2e13 CS |
1071 | if (hw_argc > 1) { |
1072 | char *p; | |
1073 | int i, j, len = 4; | |
1074 | ||
1075 | for (i = 0; i <= hw_argc - 2; i++) | |
1076 | len += strlen(as->argv[i]) + 1; | |
1077 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
1078 | if (!p) { | |
1079 | ti->error = "memory allocation failed"; | |
1080 | ret = -ENOMEM; | |
1081 | goto fail; | |
1082 | } | |
1083 | j = sprintf(p, "%d", hw_argc - 1); | |
1084 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
1085 | j = sprintf(p, "%s", as->argv[i]); | |
1086 | } | |
498f0103 | 1087 | dm_consume_args(as, hw_argc - 1); |
1da177e4 LT |
1088 | |
1089 | return 0; | |
2bfd2e13 CS |
1090 | fail: |
1091 | kfree(m->hw_handler_name); | |
1092 | m->hw_handler_name = NULL; | |
1093 | return ret; | |
1da177e4 LT |
1094 | } |
1095 | ||
498f0103 | 1096 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
1da177e4 LT |
1097 | { |
1098 | int r; | |
1099 | unsigned argc; | |
28f16c20 | 1100 | struct dm_target *ti = m->ti; |
498f0103 | 1101 | const char *arg_name; |
1da177e4 | 1102 | |
5916a22b | 1103 | static const struct dm_arg _args[] = { |
e83068a5 | 1104 | {0, 8, "invalid number of feature args"}, |
c9e45581 | 1105 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
4e2d19e4 | 1106 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
1da177e4 LT |
1107 | }; |
1108 | ||
498f0103 | 1109 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
1da177e4 LT |
1110 | if (r) |
1111 | return -EINVAL; | |
1112 | ||
1113 | if (!argc) | |
1114 | return 0; | |
1115 | ||
c9e45581 | 1116 | do { |
498f0103 | 1117 | arg_name = dm_shift_arg(as); |
c9e45581 DW |
1118 | argc--; |
1119 | ||
498f0103 | 1120 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
4c3f4838 | 1121 | r = queue_if_no_path(m, true, false, __func__); |
c9e45581 DW |
1122 | continue; |
1123 | } | |
1124 | ||
a58a935d | 1125 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
518257b1 | 1126 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); |
a58a935d MS |
1127 | continue; |
1128 | } | |
1129 | ||
498f0103 | 1130 | if (!strcasecmp(arg_name, "pg_init_retries") && |
c9e45581 | 1131 | (argc >= 1)) { |
498f0103 | 1132 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
c9e45581 DW |
1133 | argc--; |
1134 | continue; | |
1135 | } | |
1136 | ||
498f0103 | 1137 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
4e2d19e4 | 1138 | (argc >= 1)) { |
498f0103 | 1139 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
4e2d19e4 CS |
1140 | argc--; |
1141 | continue; | |
1142 | } | |
1143 | ||
e83068a5 MS |
1144 | if (!strcasecmp(arg_name, "queue_mode") && |
1145 | (argc >= 1)) { | |
1146 | const char *queue_mode_name = dm_shift_arg(as); | |
1147 | ||
1148 | if (!strcasecmp(queue_mode_name, "bio")) | |
1149 | m->queue_mode = DM_TYPE_BIO_BASED; | |
953923c0 MS |
1150 | else if (!strcasecmp(queue_mode_name, "rq") || |
1151 | !strcasecmp(queue_mode_name, "mq")) | |
e83068a5 | 1152 | m->queue_mode = DM_TYPE_REQUEST_BASED; |
e83068a5 MS |
1153 | else { |
1154 | ti->error = "Unknown 'queue_mode' requested"; | |
1155 | r = -EINVAL; | |
1156 | } | |
1157 | argc--; | |
1158 | continue; | |
1159 | } | |
1160 | ||
1da177e4 | 1161 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
1162 | r = -EINVAL; |
1163 | } while (argc && !r); | |
1164 | ||
1165 | return r; | |
1da177e4 LT |
1166 | } |
1167 | ||
e83068a5 | 1168 | static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) |
1da177e4 | 1169 | { |
498f0103 | 1170 | /* target arguments */ |
5916a22b | 1171 | static const struct dm_arg _args[] = { |
a490a07a MS |
1172 | {0, 1024, "invalid number of priority groups"}, |
1173 | {0, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
1174 | }; |
1175 | ||
1176 | int r; | |
1177 | struct multipath *m; | |
498f0103 | 1178 | struct dm_arg_set as; |
1da177e4 LT |
1179 | unsigned pg_count = 0; |
1180 | unsigned next_pg_num; | |
be240ff5 | 1181 | unsigned long flags; |
1da177e4 LT |
1182 | |
1183 | as.argc = argc; | |
1184 | as.argv = argv; | |
1185 | ||
e83068a5 | 1186 | m = alloc_multipath(ti); |
1da177e4 | 1187 | if (!m) { |
72d94861 | 1188 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
1189 | return -EINVAL; |
1190 | } | |
1191 | ||
28f16c20 | 1192 | r = parse_features(&as, m); |
1da177e4 LT |
1193 | if (r) |
1194 | goto bad; | |
1195 | ||
e83068a5 MS |
1196 | r = alloc_multipath_stage2(ti, m); |
1197 | if (r) | |
1198 | goto bad; | |
1199 | ||
28f16c20 | 1200 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
1201 | if (r) |
1202 | goto bad; | |
1203 | ||
498f0103 | 1204 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
1da177e4 LT |
1205 | if (r) |
1206 | goto bad; | |
1207 | ||
498f0103 | 1208 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
1da177e4 LT |
1209 | if (r) |
1210 | goto bad; | |
1211 | ||
a490a07a MS |
1212 | if ((!m->nr_priority_groups && next_pg_num) || |
1213 | (m->nr_priority_groups && !next_pg_num)) { | |
1214 | ti->error = "invalid initial priority group"; | |
1215 | r = -EINVAL; | |
1216 | goto bad; | |
1217 | } | |
1218 | ||
1da177e4 LT |
1219 | /* parse the priority groups */ |
1220 | while (as.argc) { | |
1221 | struct priority_group *pg; | |
91e968aa | 1222 | unsigned nr_valid_paths = atomic_read(&m->nr_valid_paths); |
1da177e4 | 1223 | |
28f16c20 | 1224 | pg = parse_priority_group(&as, m); |
01460f35 BM |
1225 | if (IS_ERR(pg)) { |
1226 | r = PTR_ERR(pg); | |
1da177e4 LT |
1227 | goto bad; |
1228 | } | |
1229 | ||
91e968aa MS |
1230 | nr_valid_paths += pg->nr_pgpaths; |
1231 | atomic_set(&m->nr_valid_paths, nr_valid_paths); | |
1232 | ||
1da177e4 LT |
1233 | list_add_tail(&pg->list, &m->priority_groups); |
1234 | pg_count++; | |
1235 | pg->pg_num = pg_count; | |
1236 | if (!--next_pg_num) | |
1237 | m->next_pg = pg; | |
1238 | } | |
1239 | ||
1240 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 1241 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
1242 | r = -EINVAL; |
1243 | goto bad; | |
1244 | } | |
1245 | ||
be240ff5 AP |
1246 | spin_lock_irqsave(&m->lock, flags); |
1247 | enable_nopath_timeout(m); | |
1248 | spin_unlock_irqrestore(&m->lock, flags); | |
1249 | ||
55a62eef AK |
1250 | ti->num_flush_bios = 1; |
1251 | ti->num_discard_bios = 1; | |
ac62d620 | 1252 | ti->num_write_zeroes_bios = 1; |
8d47e659 | 1253 | if (m->queue_mode == DM_TYPE_BIO_BASED) |
bf661be1 | 1254 | ti->per_io_data_size = multipath_per_bio_data_size(); |
eb8db831 | 1255 | else |
8637a6bf | 1256 | ti->per_io_data_size = sizeof(struct dm_mpath_io); |
8627921f | 1257 | |
1da177e4 LT |
1258 | return 0; |
1259 | ||
1260 | bad: | |
1261 | free_multipath(m); | |
1262 | return r; | |
1263 | } | |
1264 | ||
2bded7bd KU |
1265 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
1266 | { | |
9f4c3f87 | 1267 | DEFINE_WAIT(wait); |
2bded7bd KU |
1268 | |
1269 | while (1) { | |
9f4c3f87 | 1270 | prepare_to_wait(&m->pg_init_wait, &wait, TASK_UNINTERRUPTIBLE); |
2bded7bd | 1271 | |
91e968aa | 1272 | if (!atomic_read(&m->pg_init_in_progress)) |
2bded7bd | 1273 | break; |
2bded7bd KU |
1274 | |
1275 | io_schedule(); | |
1276 | } | |
9f4c3f87 | 1277 | finish_wait(&m->pg_init_wait, &wait); |
2bded7bd KU |
1278 | } |
1279 | ||
1280 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 1281 | { |
848b8aef | 1282 | if (m->hw_handler_name) { |
c322ee93 MS |
1283 | unsigned long flags; |
1284 | ||
1285 | if (!atomic_read(&m->pg_init_in_progress)) | |
1286 | goto skip; | |
1287 | ||
1288 | spin_lock_irqsave(&m->lock, flags); | |
1289 | if (atomic_read(&m->pg_init_in_progress) && | |
1290 | !test_and_set_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) { | |
1291 | spin_unlock_irqrestore(&m->lock, flags); | |
848b8aef | 1292 | |
935fcc56 | 1293 | flush_workqueue(kmpath_handlerd); |
c322ee93 | 1294 | multipath_wait_for_pg_init_completion(m); |
848b8aef | 1295 | |
c322ee93 MS |
1296 | spin_lock_irqsave(&m->lock, flags); |
1297 | clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags); | |
1298 | } | |
1299 | spin_unlock_irqrestore(&m->lock, flags); | |
848b8aef | 1300 | } |
c322ee93 | 1301 | skip: |
935fcc56 | 1302 | if (m->queue_mode == DM_TYPE_BIO_BASED) |
1303 | flush_work(&m->process_queued_bios); | |
43829731 | 1304 | flush_work(&m->trigger_event); |
6df400ab KU |
1305 | } |
1306 | ||
1307 | static void multipath_dtr(struct dm_target *ti) | |
1308 | { | |
1309 | struct multipath *m = ti->private; | |
1310 | ||
be240ff5 | 1311 | disable_nopath_timeout(m); |
2bded7bd | 1312 | flush_multipath_work(m); |
1da177e4 LT |
1313 | free_multipath(m); |
1314 | } | |
1315 | ||
1da177e4 LT |
1316 | /* |
1317 | * Take a path out of use. | |
1318 | */ | |
1319 | static int fail_path(struct pgpath *pgpath) | |
1320 | { | |
1321 | unsigned long flags; | |
1322 | struct multipath *m = pgpath->pg->m; | |
1323 | ||
1324 | spin_lock_irqsave(&m->lock, flags); | |
1325 | ||
6680073d | 1326 | if (!pgpath->is_active) |
1da177e4 LT |
1327 | goto out; |
1328 | ||
04867370 | 1329 | DMWARN("%s: Failing path %s.", |
d4a512ed | 1330 | dm_table_device_name(m->ti->table), |
04867370 | 1331 | pgpath->path.dev->name); |
1da177e4 LT |
1332 | |
1333 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
be7d31cc | 1334 | pgpath->is_active = false; |
1da177e4 LT |
1335 | pgpath->fail_count++; |
1336 | ||
91e968aa | 1337 | atomic_dec(&m->nr_valid_paths); |
1da177e4 LT |
1338 | |
1339 | if (pgpath == m->current_pgpath) | |
1340 | m->current_pgpath = NULL; | |
1341 | ||
b15546f9 | 1342 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
91e968aa | 1343 | pgpath->path.dev->name, atomic_read(&m->nr_valid_paths)); |
b15546f9 | 1344 | |
fe9cf30e | 1345 | schedule_work(&m->trigger_event); |
1da177e4 | 1346 | |
be240ff5 AP |
1347 | enable_nopath_timeout(m); |
1348 | ||
1da177e4 LT |
1349 | out: |
1350 | spin_unlock_irqrestore(&m->lock, flags); | |
1351 | ||
1352 | return 0; | |
1353 | } | |
1354 | ||
1355 | /* | |
1356 | * Reinstate a previously-failed path | |
1357 | */ | |
1358 | static int reinstate_path(struct pgpath *pgpath) | |
1359 | { | |
63d832c3 | 1360 | int r = 0, run_queue = 0; |
1da177e4 LT |
1361 | unsigned long flags; |
1362 | struct multipath *m = pgpath->pg->m; | |
91e968aa | 1363 | unsigned nr_valid_paths; |
1da177e4 LT |
1364 | |
1365 | spin_lock_irqsave(&m->lock, flags); | |
1366 | ||
6680073d | 1367 | if (pgpath->is_active) |
1da177e4 LT |
1368 | goto out; |
1369 | ||
04867370 | 1370 | DMWARN("%s: Reinstating path %s.", |
d4a512ed | 1371 | dm_table_device_name(m->ti->table), |
04867370 | 1372 | pgpath->path.dev->name); |
1da177e4 LT |
1373 | |
1374 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1375 | if (r) | |
1376 | goto out; | |
1377 | ||
be7d31cc | 1378 | pgpath->is_active = true; |
1da177e4 | 1379 | |
91e968aa MS |
1380 | nr_valid_paths = atomic_inc_return(&m->nr_valid_paths); |
1381 | if (nr_valid_paths == 1) { | |
e54f77dd | 1382 | m->current_pgpath = NULL; |
63d832c3 | 1383 | run_queue = 1; |
e54f77dd | 1384 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
4e2d19e4 | 1385 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
91e968aa | 1386 | atomic_inc(&m->pg_init_in_progress); |
e54f77dd | 1387 | } |
1da177e4 | 1388 | |
b15546f9 | 1389 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
91e968aa | 1390 | pgpath->path.dev->name, nr_valid_paths); |
b15546f9 | 1391 | |
fe9cf30e | 1392 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1393 | |
1394 | out: | |
1395 | spin_unlock_irqrestore(&m->lock, flags); | |
76e33fe4 | 1396 | if (run_queue) { |
63d832c3 | 1397 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 1398 | process_queued_io_list(m); |
76e33fe4 | 1399 | } |
1da177e4 | 1400 | |
be240ff5 AP |
1401 | if (pgpath->is_active) |
1402 | disable_nopath_timeout(m); | |
1403 | ||
1da177e4 LT |
1404 | return r; |
1405 | } | |
1406 | ||
1407 | /* | |
1408 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1409 | */ | |
1410 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1411 | action_fn action) | |
1412 | { | |
19040c0b | 1413 | int r = -EINVAL; |
1da177e4 LT |
1414 | struct pgpath *pgpath; |
1415 | struct priority_group *pg; | |
1416 | ||
1417 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1418 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1419 | if (pgpath->path.dev == dev) | |
1420 | r = action(pgpath); | |
1421 | } | |
1422 | } | |
1423 | ||
1424 | return r; | |
1425 | } | |
1426 | ||
1427 | /* | |
1428 | * Temporarily try to avoid having to use the specified PG | |
1429 | */ | |
1430 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
be7d31cc | 1431 | bool bypassed) |
1da177e4 LT |
1432 | { |
1433 | unsigned long flags; | |
1434 | ||
1435 | spin_lock_irqsave(&m->lock, flags); | |
1436 | ||
1437 | pg->bypassed = bypassed; | |
1438 | m->current_pgpath = NULL; | |
1439 | m->current_pg = NULL; | |
1440 | ||
1441 | spin_unlock_irqrestore(&m->lock, flags); | |
1442 | ||
fe9cf30e | 1443 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1444 | } |
1445 | ||
1446 | /* | |
1447 | * Switch to using the specified PG from the next I/O that gets mapped | |
1448 | */ | |
1449 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1450 | { | |
1451 | struct priority_group *pg; | |
1452 | unsigned pgnum; | |
1453 | unsigned long flags; | |
31998ef1 | 1454 | char dummy; |
1da177e4 | 1455 | |
31998ef1 | 1456 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1457 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1458 | DMWARN("invalid PG number supplied to switch_pg_num"); |
1459 | return -EINVAL; | |
1460 | } | |
1461 | ||
1462 | spin_lock_irqsave(&m->lock, flags); | |
1463 | list_for_each_entry(pg, &m->priority_groups, list) { | |
be7d31cc | 1464 | pg->bypassed = false; |
1da177e4 LT |
1465 | if (--pgnum) |
1466 | continue; | |
1467 | ||
1468 | m->current_pgpath = NULL; | |
1469 | m->current_pg = NULL; | |
1470 | m->next_pg = pg; | |
1471 | } | |
1472 | spin_unlock_irqrestore(&m->lock, flags); | |
1473 | ||
fe9cf30e | 1474 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1475 | return 0; |
1476 | } | |
1477 | ||
1478 | /* | |
1479 | * Set/clear bypassed status of a PG. | |
1480 | * PGs are numbered upwards from 1 in the order they were declared. | |
1481 | */ | |
be7d31cc | 1482 | static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) |
1da177e4 LT |
1483 | { |
1484 | struct priority_group *pg; | |
1485 | unsigned pgnum; | |
31998ef1 | 1486 | char dummy; |
1da177e4 | 1487 | |
31998ef1 | 1488 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1489 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1490 | DMWARN("invalid PG number supplied to bypass_pg"); |
1491 | return -EINVAL; | |
1492 | } | |
1493 | ||
1494 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1495 | if (!--pgnum) | |
1496 | break; | |
1497 | } | |
1498 | ||
1499 | bypass_pg(m, pg, bypassed); | |
1500 | return 0; | |
1501 | } | |
1502 | ||
c9e45581 DW |
1503 | /* |
1504 | * Should we retry pg_init immediately? | |
1505 | */ | |
be7d31cc | 1506 | static bool pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) |
c9e45581 DW |
1507 | { |
1508 | unsigned long flags; | |
be7d31cc | 1509 | bool limit_reached = false; |
c9e45581 DW |
1510 | |
1511 | spin_lock_irqsave(&m->lock, flags); | |
1512 | ||
91e968aa MS |
1513 | if (atomic_read(&m->pg_init_count) <= m->pg_init_retries && |
1514 | !test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) | |
518257b1 | 1515 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
c9e45581 | 1516 | else |
be7d31cc | 1517 | limit_reached = true; |
c9e45581 DW |
1518 | |
1519 | spin_unlock_irqrestore(&m->lock, flags); | |
1520 | ||
1521 | return limit_reached; | |
1522 | } | |
1523 | ||
3ae31f6a | 1524 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1525 | { |
83c0d5d5 | 1526 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1527 | struct priority_group *pg = pgpath->pg; |
1528 | struct multipath *m = pg->m; | |
1529 | unsigned long flags; | |
be7d31cc | 1530 | bool delay_retry = false; |
cfae5c9b CS |
1531 | |
1532 | /* device or driver problems */ | |
1533 | switch (errors) { | |
1534 | case SCSI_DH_OK: | |
1535 | break; | |
1536 | case SCSI_DH_NOSYS: | |
1537 | if (!m->hw_handler_name) { | |
1538 | errors = 0; | |
1539 | break; | |
1540 | } | |
f7b934c8 MB |
1541 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1542 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1543 | /* |
1544 | * Fail path for now, so we do not ping pong | |
1545 | */ | |
1546 | fail_path(pgpath); | |
1547 | break; | |
1548 | case SCSI_DH_DEV_TEMP_BUSY: | |
1549 | /* | |
1550 | * Probably doing something like FW upgrade on the | |
1551 | * controller so try the other pg. | |
1552 | */ | |
be7d31cc | 1553 | bypass_pg(m, pg, true); |
cfae5c9b | 1554 | break; |
cfae5c9b | 1555 | case SCSI_DH_RETRY: |
4e2d19e4 | 1556 | /* Wait before retrying. */ |
4ecc5081 | 1557 | delay_retry = true; |
df561f66 | 1558 | fallthrough; |
cfae5c9b CS |
1559 | case SCSI_DH_IMM_RETRY: |
1560 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1561 | if (pg_init_limit_reached(m, pgpath)) | |
1562 | fail_path(pgpath); | |
1563 | errors = 0; | |
1564 | break; | |
ec31f3f7 | 1565 | case SCSI_DH_DEV_OFFLINED: |
cfae5c9b CS |
1566 | default: |
1567 | /* | |
1568 | * We probably do not want to fail the path for a device | |
1569 | * error, but this is what the old dm did. In future | |
1570 | * patches we can do more advanced handling. | |
1571 | */ | |
1572 | fail_path(pgpath); | |
1573 | } | |
1574 | ||
1575 | spin_lock_irqsave(&m->lock, flags); | |
1576 | if (errors) { | |
e54f77dd CS |
1577 | if (pgpath == m->current_pgpath) { |
1578 | DMERR("Could not failover device. Error %d.", errors); | |
1579 | m->current_pgpath = NULL; | |
1580 | m->current_pg = NULL; | |
1581 | } | |
518257b1 | 1582 | } else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
be7d31cc | 1583 | pg->bypassed = false; |
cfae5c9b | 1584 | |
91e968aa | 1585 | if (atomic_dec_return(&m->pg_init_in_progress) > 0) |
d0259bf0 KU |
1586 | /* Activations of other paths are still on going */ |
1587 | goto out; | |
1588 | ||
518257b1 MS |
1589 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) { |
1590 | if (delay_retry) | |
1591 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1592 | else | |
1593 | clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1594 | ||
3e9f1be1 HR |
1595 | if (__pg_init_all_paths(m)) |
1596 | goto out; | |
1597 | } | |
518257b1 | 1598 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
d0259bf0 | 1599 | |
7e48c768 | 1600 | process_queued_io_list(m); |
76e33fe4 | 1601 | |
2bded7bd KU |
1602 | /* |
1603 | * Wake up any thread waiting to suspend. | |
1604 | */ | |
1605 | wake_up(&m->pg_init_wait); | |
1606 | ||
d0259bf0 | 1607 | out: |
cfae5c9b CS |
1608 | spin_unlock_irqrestore(&m->lock, flags); |
1609 | } | |
1610 | ||
89bfce76 | 1611 | static void activate_or_offline_path(struct pgpath *pgpath) |
bab7cfc7 | 1612 | { |
f10e06b7 | 1613 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); |
bab7cfc7 | 1614 | |
f10e06b7 MS |
1615 | if (pgpath->is_active && !blk_queue_dying(q)) |
1616 | scsi_dh_activate(q, pg_init_done, pgpath); | |
3a017509 HR |
1617 | else |
1618 | pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); | |
bab7cfc7 CS |
1619 | } |
1620 | ||
89bfce76 BVA |
1621 | static void activate_path_work(struct work_struct *work) |
1622 | { | |
1623 | struct pgpath *pgpath = | |
1624 | container_of(work, struct pgpath, activate_path.work); | |
1625 | ||
1626 | activate_or_offline_path(pgpath); | |
1627 | } | |
1628 | ||
b79f10ee | 1629 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
2a842aca | 1630 | blk_status_t error, union map_info *map_context) |
1da177e4 | 1631 | { |
b79f10ee CH |
1632 | struct dm_mpath_io *mpio = get_mpio(map_context); |
1633 | struct pgpath *pgpath = mpio->pgpath; | |
7ed8578a | 1634 | int r = DM_ENDIO_DONE; |
b79f10ee | 1635 | |
f40c67f0 KU |
1636 | /* |
1637 | * We don't queue any clone request inside the multipath target | |
1638 | * during end I/O handling, since those clone requests don't have | |
1639 | * bio clones. If we queue them inside the multipath target, | |
1640 | * we need to make bio clones, that requires memory allocation. | |
4cc96131 | 1641 | * (See drivers/md/dm-rq.c:end_clone_bio() about why the clone requests |
f40c67f0 KU |
1642 | * don't have bio clones.) |
1643 | * Instead of queueing the clone request here, we queue the original | |
1644 | * request into dm core, which will remake a clone request and | |
1645 | * clone bios for it and resubmit it later. | |
1646 | */ | |
a1275677 | 1647 | if (error && blk_path_error(error)) { |
b79f10ee | 1648 | struct multipath *m = ti->private; |
1da177e4 | 1649 | |
ac514ffc MS |
1650 | if (error == BLK_STS_RESOURCE) |
1651 | r = DM_ENDIO_DELAY_REQUEUE; | |
1652 | else | |
1653 | r = DM_ENDIO_REQUEUE; | |
1da177e4 | 1654 | |
b79f10ee CH |
1655 | if (pgpath) |
1656 | fail_path(pgpath); | |
1da177e4 | 1657 | |
73265f3f | 1658 | if (!atomic_read(&m->nr_valid_paths) && |
c1fd0abe | 1659 | !must_push_back_rq(m)) { |
2a842aca | 1660 | if (error == BLK_STS_IOERR) |
18a482f5 | 1661 | dm_report_EIO(m); |
7ed8578a CH |
1662 | /* complete with the original error */ |
1663 | r = DM_ENDIO_DONE; | |
1664 | } | |
b79f10ee | 1665 | } |
466891f9 | 1666 | |
1da177e4 | 1667 | if (pgpath) { |
b79f10ee CH |
1668 | struct path_selector *ps = &pgpath->pg->ps; |
1669 | ||
1da177e4 | 1670 | if (ps->type->end_io) |
087615bf GKB |
1671 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes, |
1672 | clone->io_start_time_ns); | |
1da177e4 | 1673 | } |
1da177e4 | 1674 | |
7ed8578a | 1675 | return r; |
1da177e4 LT |
1676 | } |
1677 | ||
4e4cbee9 | 1678 | static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, |
848b8aef | 1679 | blk_status_t *error) |
76e33fe4 | 1680 | { |
14ef1e48 CH |
1681 | struct multipath *m = ti->private; |
1682 | struct dm_mpath_io *mpio = get_mpio_from_bio(clone); | |
1683 | struct pgpath *pgpath = mpio->pgpath; | |
76e33fe4 | 1684 | unsigned long flags; |
1be56909 | 1685 | int r = DM_ENDIO_DONE; |
76e33fe4 | 1686 | |
a1275677 | 1687 | if (!*error || !blk_path_error(*error)) |
14ef1e48 | 1688 | goto done; |
76e33fe4 | 1689 | |
14ef1e48 CH |
1690 | if (pgpath) |
1691 | fail_path(pgpath); | |
76e33fe4 | 1692 | |
a271a89c MS |
1693 | if (!atomic_read(&m->nr_valid_paths)) { |
1694 | spin_lock_irqsave(&m->lock, flags); | |
1695 | if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
1696 | if (__must_push_back(m)) { | |
1697 | r = DM_ENDIO_REQUEUE; | |
1698 | } else { | |
1699 | dm_report_EIO(m); | |
1700 | *error = BLK_STS_IOERR; | |
1701 | } | |
1702 | spin_unlock_irqrestore(&m->lock, flags); | |
1703 | goto done; | |
c1fd0abe | 1704 | } |
a271a89c | 1705 | spin_unlock_irqrestore(&m->lock, flags); |
18a482f5 | 1706 | } |
76e33fe4 | 1707 | |
f45f1186 | 1708 | multipath_queue_bio(m, clone); |
1be56909 | 1709 | r = DM_ENDIO_INCOMPLETE; |
14ef1e48 | 1710 | done: |
76e33fe4 | 1711 | if (pgpath) { |
14ef1e48 CH |
1712 | struct path_selector *ps = &pgpath->pg->ps; |
1713 | ||
76e33fe4 | 1714 | if (ps->type->end_io) |
087615bf GKB |
1715 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes, |
1716 | dm_start_time_ns_from_clone(clone)); | |
76e33fe4 MS |
1717 | } |
1718 | ||
1be56909 | 1719 | return r; |
76e33fe4 MS |
1720 | } |
1721 | ||
1da177e4 | 1722 | /* |
553ec94c MS |
1723 | * Suspend with flush can't complete until all the I/O is processed |
1724 | * so if the last path fails we must error any remaining I/O. | |
1725 | * - Note that if the freeze_bdev fails while suspending, the | |
1726 | * queue_if_no_path state is lost - userspace should reset it. | |
1727 | * Otherwise, during noflush suspend, queue_if_no_path will not change. | |
1da177e4 LT |
1728 | */ |
1729 | static void multipath_presuspend(struct dm_target *ti) | |
1730 | { | |
7943bd6d | 1731 | struct multipath *m = ti->private; |
1da177e4 | 1732 | |
553ec94c MS |
1733 | /* FIXME: bio-based shouldn't need to always disable queue_if_no_path */ |
1734 | if (m->queue_mode == DM_TYPE_BIO_BASED || !dm_noflush_suspending(m->ti)) | |
4c3f4838 | 1735 | queue_if_no_path(m, false, true, __func__); |
1da177e4 LT |
1736 | } |
1737 | ||
6df400ab KU |
1738 | static void multipath_postsuspend(struct dm_target *ti) |
1739 | { | |
6380f26f MA |
1740 | struct multipath *m = ti->private; |
1741 | ||
1742 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1743 | flush_multipath_work(m); |
6380f26f | 1744 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1745 | } |
1746 | ||
436d4108 AK |
1747 | /* |
1748 | * Restore the queue_if_no_path setting. | |
1749 | */ | |
1da177e4 LT |
1750 | static void multipath_resume(struct dm_target *ti) |
1751 | { | |
7943bd6d | 1752 | struct multipath *m = ti->private; |
1814f2e3 | 1753 | unsigned long flags; |
1da177e4 | 1754 | |
1814f2e3 | 1755 | spin_lock_irqsave(&m->lock, flags); |
553ec94c MS |
1756 | if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) { |
1757 | set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); | |
1758 | clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
1759 | } | |
4c3f4838 MS |
1760 | |
1761 | DMDEBUG("%s: %s finished; QIFNP = %d; SQIFNP = %d", | |
d4a512ed | 1762 | dm_table_device_name(m->ti->table), __func__, |
4c3f4838 MS |
1763 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags), |
1764 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)); | |
1765 | ||
1814f2e3 | 1766 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1767 | } |
1768 | ||
1769 | /* | |
1770 | * Info output has the following format: | |
1771 | * num_multipath_feature_args [multipath_feature_args]* | |
1772 | * num_handler_status_args [handler_status_args]* | |
1773 | * num_groups init_group_number | |
1774 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1775 | * num_paths num_selector_args | |
1776 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1777 | * | |
1778 | * Table output has the following format (identical to the constructor string): | |
1779 | * num_feature_args [features_args]* | |
1780 | * num_handler_args hw_handler [hw_handler_args]* | |
1781 | * num_groups init_group_number | |
1782 | * [priority selector-name num_ps_args [ps_args]* | |
1783 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1784 | */ | |
fd7c092e MP |
1785 | static void multipath_status(struct dm_target *ti, status_type_t type, |
1786 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 | 1787 | { |
33ace4ca | 1788 | int sz = 0, pg_counter, pgpath_counter; |
1da177e4 | 1789 | unsigned long flags; |
7943bd6d | 1790 | struct multipath *m = ti->private; |
1da177e4 LT |
1791 | struct priority_group *pg; |
1792 | struct pgpath *p; | |
1793 | unsigned pg_num; | |
1794 | char state; | |
1795 | ||
1796 | spin_lock_irqsave(&m->lock, flags); | |
1797 | ||
1798 | /* Features */ | |
1799 | if (type == STATUSTYPE_INFO) | |
91e968aa MS |
1800 | DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags), |
1801 | atomic_read(&m->pg_init_count)); | |
c9e45581 | 1802 | else { |
518257b1 | 1803 | DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) + |
4e2d19e4 | 1804 | (m->pg_init_retries > 0) * 2 + |
a58a935d | 1805 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
e83068a5 MS |
1806 | test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) + |
1807 | (m->queue_mode != DM_TYPE_REQUEST_BASED) * 2); | |
1808 | ||
518257b1 | 1809 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
c9e45581 DW |
1810 | DMEMIT("queue_if_no_path "); |
1811 | if (m->pg_init_retries) | |
1812 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
4e2d19e4 CS |
1813 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
1814 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); | |
518257b1 | 1815 | if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) |
a58a935d | 1816 | DMEMIT("retain_attached_hw_handler "); |
e83068a5 MS |
1817 | if (m->queue_mode != DM_TYPE_REQUEST_BASED) { |
1818 | switch(m->queue_mode) { | |
1819 | case DM_TYPE_BIO_BASED: | |
1820 | DMEMIT("queue_mode bio "); | |
1821 | break; | |
7e0d574f BVA |
1822 | default: |
1823 | WARN_ON_ONCE(true); | |
1824 | break; | |
e83068a5 MS |
1825 | } |
1826 | } | |
c9e45581 | 1827 | } |
1da177e4 | 1828 | |
cfae5c9b | 1829 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1830 | DMEMIT("0 "); |
1831 | else | |
cfae5c9b | 1832 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1833 | |
1834 | DMEMIT("%u ", m->nr_priority_groups); | |
1835 | ||
1836 | if (m->next_pg) | |
1837 | pg_num = m->next_pg->pg_num; | |
1838 | else if (m->current_pg) | |
1839 | pg_num = m->current_pg->pg_num; | |
1840 | else | |
a490a07a | 1841 | pg_num = (m->nr_priority_groups ? 1 : 0); |
1da177e4 LT |
1842 | |
1843 | DMEMIT("%u ", pg_num); | |
1844 | ||
1845 | switch (type) { | |
1846 | case STATUSTYPE_INFO: | |
1847 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1848 | if (pg->bypassed) | |
1849 | state = 'D'; /* Disabled */ | |
1850 | else if (pg == m->current_pg) | |
1851 | state = 'A'; /* Currently Active */ | |
1852 | else | |
1853 | state = 'E'; /* Enabled */ | |
1854 | ||
1855 | DMEMIT("%c ", state); | |
1856 | ||
1857 | if (pg->ps.type->status) | |
1858 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1859 | result + sz, | |
1860 | maxlen - sz); | |
1861 | else | |
1862 | DMEMIT("0 "); | |
1863 | ||
1864 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1865 | pg->ps.type->info_args); | |
1866 | ||
1867 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1868 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1869 | p->is_active ? "A" : "F", |
1da177e4 LT |
1870 | p->fail_count); |
1871 | if (pg->ps.type->status) | |
1872 | sz += pg->ps.type->status(&pg->ps, | |
1873 | &p->path, type, result + sz, | |
1874 | maxlen - sz); | |
1875 | } | |
1876 | } | |
1877 | break; | |
1878 | ||
1879 | case STATUSTYPE_TABLE: | |
1880 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1881 | DMEMIT("%s ", pg->ps.type->name); | |
1882 | ||
1883 | if (pg->ps.type->status) | |
1884 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1885 | result + sz, | |
1886 | maxlen - sz); | |
1887 | else | |
1888 | DMEMIT("0 "); | |
1889 | ||
1890 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1891 | pg->ps.type->table_args); | |
1892 | ||
1893 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1894 | DMEMIT("%s ", p->path.dev->name); | |
1895 | if (pg->ps.type->status) | |
1896 | sz += pg->ps.type->status(&pg->ps, | |
1897 | &p->path, type, result + sz, | |
1898 | maxlen - sz); | |
1899 | } | |
1900 | } | |
1901 | break; | |
8ec45662 TS |
1902 | |
1903 | case STATUSTYPE_IMA: | |
33ace4ca TS |
1904 | sz = 0; /*reset the result pointer*/ |
1905 | ||
8ec45662 | 1906 | DMEMIT_TARGET_NAME_VERSION(ti->type); |
33ace4ca TS |
1907 | DMEMIT(",nr_priority_groups=%u", m->nr_priority_groups); |
1908 | ||
1909 | pg_counter = 0; | |
8ec45662 TS |
1910 | list_for_each_entry(pg, &m->priority_groups, list) { |
1911 | if (pg->bypassed) | |
1912 | state = 'D'; /* Disabled */ | |
1913 | else if (pg == m->current_pg) | |
1914 | state = 'A'; /* Currently Active */ | |
1915 | else | |
1916 | state = 'E'; /* Enabled */ | |
33ace4ca TS |
1917 | DMEMIT(",pg_state_%d=%c", pg_counter, state); |
1918 | DMEMIT(",nr_pgpaths_%d=%u", pg_counter, pg->nr_pgpaths); | |
1919 | DMEMIT(",path_selector_name_%d=%s", pg_counter, pg->ps.type->name); | |
8ec45662 | 1920 | |
33ace4ca | 1921 | pgpath_counter = 0; |
8ec45662 | 1922 | list_for_each_entry(p, &pg->pgpaths, list) { |
33ace4ca TS |
1923 | DMEMIT(",path_name_%d_%d=%s,is_active_%d_%d=%c,fail_count_%d_%d=%u", |
1924 | pg_counter, pgpath_counter, p->path.dev->name, | |
1925 | pg_counter, pgpath_counter, p->is_active ? 'A' : 'F', | |
1926 | pg_counter, pgpath_counter, p->fail_count); | |
8ec45662 | 1927 | if (pg->ps.type->status) { |
33ace4ca TS |
1928 | DMEMIT(",path_selector_status_%d_%d=", |
1929 | pg_counter, pgpath_counter); | |
8ec45662 TS |
1930 | sz += pg->ps.type->status(&pg->ps, &p->path, |
1931 | type, result + sz, | |
1932 | maxlen - sz); | |
1933 | } | |
33ace4ca | 1934 | pgpath_counter++; |
8ec45662 | 1935 | } |
33ace4ca | 1936 | pg_counter++; |
8ec45662 TS |
1937 | } |
1938 | DMEMIT(";"); | |
1939 | break; | |
1da177e4 LT |
1940 | } |
1941 | ||
1942 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
1943 | } |
1944 | ||
1eb5fa84 MS |
1945 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv, |
1946 | char *result, unsigned maxlen) | |
1da177e4 | 1947 | { |
6380f26f | 1948 | int r = -EINVAL; |
1da177e4 | 1949 | struct dm_dev *dev; |
7943bd6d | 1950 | struct multipath *m = ti->private; |
1da177e4 | 1951 | action_fn action; |
be240ff5 | 1952 | unsigned long flags; |
1da177e4 | 1953 | |
6380f26f MA |
1954 | mutex_lock(&m->work_mutex); |
1955 | ||
c2f3d24b KU |
1956 | if (dm_suspended(ti)) { |
1957 | r = -EBUSY; | |
1958 | goto out; | |
1959 | } | |
1960 | ||
1da177e4 | 1961 | if (argc == 1) { |
498f0103 | 1962 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
4c3f4838 | 1963 | r = queue_if_no_path(m, true, false, __func__); |
be240ff5 AP |
1964 | spin_lock_irqsave(&m->lock, flags); |
1965 | enable_nopath_timeout(m); | |
1966 | spin_unlock_irqrestore(&m->lock, flags); | |
6380f26f | 1967 | goto out; |
498f0103 | 1968 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
4c3f4838 | 1969 | r = queue_if_no_path(m, false, false, __func__); |
be240ff5 | 1970 | disable_nopath_timeout(m); |
6380f26f MA |
1971 | goto out; |
1972 | } | |
1da177e4 LT |
1973 | } |
1974 | ||
6380f26f | 1975 | if (argc != 2) { |
a356e426 | 1976 | DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); |
6380f26f MA |
1977 | goto out; |
1978 | } | |
1da177e4 | 1979 | |
498f0103 | 1980 | if (!strcasecmp(argv[0], "disable_group")) { |
be7d31cc | 1981 | r = bypass_pg_num(m, argv[1], true); |
6380f26f | 1982 | goto out; |
498f0103 | 1983 | } else if (!strcasecmp(argv[0], "enable_group")) { |
be7d31cc | 1984 | r = bypass_pg_num(m, argv[1], false); |
6380f26f | 1985 | goto out; |
498f0103 | 1986 | } else if (!strcasecmp(argv[0], "switch_group")) { |
6380f26f MA |
1987 | r = switch_pg_num(m, argv[1]); |
1988 | goto out; | |
498f0103 | 1989 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
1da177e4 | 1990 | action = reinstate_path; |
498f0103 | 1991 | else if (!strcasecmp(argv[0], "fail_path")) |
1da177e4 | 1992 | action = fail_path; |
6380f26f | 1993 | else { |
a356e426 | 1994 | DMWARN("Unrecognised multipath message received: %s", argv[0]); |
6380f26f MA |
1995 | goto out; |
1996 | } | |
1da177e4 | 1997 | |
8215d6ec | 1998 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 1999 | if (r) { |
72d94861 | 2000 | DMWARN("message: error getting device %s", |
1da177e4 | 2001 | argv[1]); |
6380f26f | 2002 | goto out; |
1da177e4 LT |
2003 | } |
2004 | ||
2005 | r = action_dev(m, dev, action); | |
2006 | ||
2007 | dm_put_device(ti, dev); | |
2008 | ||
6380f26f MA |
2009 | out: |
2010 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 2011 | return r; |
1da177e4 LT |
2012 | } |
2013 | ||
e56f81e0 | 2014 | static int multipath_prepare_ioctl(struct dm_target *ti, |
5bd5e8d8 | 2015 | struct block_device **bdev) |
9af4aa30 | 2016 | { |
35991652 | 2017 | struct multipath *m = ti->private; |
564dbb13 | 2018 | struct pgpath *pgpath; |
69cea0d4 | 2019 | unsigned long flags; |
35991652 MP |
2020 | int r; |
2021 | ||
564dbb13 | 2022 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 2023 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
564dbb13 | 2024 | pgpath = choose_pgpath(m, 0); |
9af4aa30 | 2025 | |
564dbb13 | 2026 | if (pgpath) { |
374117ad | 2027 | if (!mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) { |
564dbb13 | 2028 | *bdev = pgpath->path.dev->bdev; |
43e43c9e JN |
2029 | r = 0; |
2030 | } else { | |
2031 | /* pg_init has not started or completed */ | |
2032 | r = -ENOTCONN; | |
2033 | } | |
2034 | } else { | |
2035 | /* No path is available */ | |
a271a89c MS |
2036 | r = -EIO; |
2037 | spin_lock_irqsave(&m->lock, flags); | |
518257b1 | 2038 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
43e43c9e | 2039 | r = -ENOTCONN; |
a271a89c | 2040 | spin_unlock_irqrestore(&m->lock, flags); |
e90dae1f | 2041 | } |
9af4aa30 | 2042 | |
5bbbfdf6 | 2043 | if (r == -ENOTCONN) { |
506458ef | 2044 | if (!READ_ONCE(m->current_pg)) { |
3e9f1be1 | 2045 | /* Path status changed, redo selection */ |
2da1610a | 2046 | (void) choose_pgpath(m, 0); |
3e9f1be1 | 2047 | } |
69cea0d4 | 2048 | spin_lock_irqsave(&m->lock, flags); |
518257b1 | 2049 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
69cea0d4 MS |
2050 | (void) __pg_init_all_paths(m); |
2051 | spin_unlock_irqrestore(&m->lock, flags); | |
63d832c3 | 2052 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 2053 | process_queued_io_list(m); |
3e9f1be1 | 2054 | } |
35991652 | 2055 | |
e56f81e0 CH |
2056 | /* |
2057 | * Only pass ioctls through if the device sizes match exactly. | |
2058 | */ | |
6dcbb52c | 2059 | if (!r && ti->len != bdev_nr_sectors((*bdev))) |
e56f81e0 CH |
2060 | return 1; |
2061 | return r; | |
9af4aa30 MB |
2062 | } |
2063 | ||
af4874e0 MS |
2064 | static int multipath_iterate_devices(struct dm_target *ti, |
2065 | iterate_devices_callout_fn fn, void *data) | |
2066 | { | |
2067 | struct multipath *m = ti->private; | |
2068 | struct priority_group *pg; | |
2069 | struct pgpath *p; | |
2070 | int ret = 0; | |
2071 | ||
2072 | list_for_each_entry(pg, &m->priority_groups, list) { | |
2073 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 2074 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
2075 | if (ret) |
2076 | goto out; | |
2077 | } | |
2078 | } | |
2079 | ||
2080 | out: | |
2081 | return ret; | |
2082 | } | |
2083 | ||
9f54cec5 | 2084 | static int pgpath_busy(struct pgpath *pgpath) |
f40c67f0 KU |
2085 | { |
2086 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
2087 | ||
52b09914 | 2088 | return blk_lld_busy(q); |
f40c67f0 KU |
2089 | } |
2090 | ||
2091 | /* | |
2092 | * We return "busy", only when we can map I/Os but underlying devices | |
2093 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
2094 | * the underlying queue). | |
2095 | * In other words, if we want to kill I/Os or queue them inside us | |
2096 | * due to map unavailability, we don't return "busy". Otherwise, | |
2097 | * dm core won't give us the I/Os and we can't do what we want. | |
2098 | */ | |
2099 | static int multipath_busy(struct dm_target *ti) | |
2100 | { | |
be7d31cc | 2101 | bool busy = false, has_active = false; |
f40c67f0 | 2102 | struct multipath *m = ti->private; |
2da1610a | 2103 | struct priority_group *pg, *next_pg; |
f40c67f0 | 2104 | struct pgpath *pgpath; |
f40c67f0 | 2105 | |
b88efd43 MS |
2106 | /* pg_init in progress */ |
2107 | if (atomic_read(&m->pg_init_in_progress)) | |
2da1610a MS |
2108 | return true; |
2109 | ||
b88efd43 | 2110 | /* no paths available, for blk-mq: rely on IO mapping to delay requeue */ |
a271a89c MS |
2111 | if (!atomic_read(&m->nr_valid_paths)) { |
2112 | unsigned long flags; | |
2113 | spin_lock_irqsave(&m->lock, flags); | |
2114 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
2115 | spin_unlock_irqrestore(&m->lock, flags); | |
2116 | return (m->queue_mode != DM_TYPE_REQUEST_BASED); | |
2117 | } | |
2118 | spin_unlock_irqrestore(&m->lock, flags); | |
2119 | } | |
b88efd43 | 2120 | |
f40c67f0 | 2121 | /* Guess which priority_group will be used at next mapping time */ |
506458ef WD |
2122 | pg = READ_ONCE(m->current_pg); |
2123 | next_pg = READ_ONCE(m->next_pg); | |
2124 | if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg)) | |
2da1610a MS |
2125 | pg = next_pg; |
2126 | ||
2127 | if (!pg) { | |
f40c67f0 KU |
2128 | /* |
2129 | * We don't know which pg will be used at next mapping time. | |
2da1610a | 2130 | * We don't call choose_pgpath() here to avoid to trigger |
f40c67f0 KU |
2131 | * pg_init just by busy checking. |
2132 | * So we don't know whether underlying devices we will be using | |
2133 | * at next mapping time are busy or not. Just try mapping. | |
2134 | */ | |
2da1610a MS |
2135 | return busy; |
2136 | } | |
f40c67f0 KU |
2137 | |
2138 | /* | |
2139 | * If there is one non-busy active path at least, the path selector | |
2140 | * will be able to select it. So we consider such a pg as not busy. | |
2141 | */ | |
be7d31cc | 2142 | busy = true; |
2da1610a | 2143 | list_for_each_entry(pgpath, &pg->pgpaths, list) { |
f40c67f0 | 2144 | if (pgpath->is_active) { |
be7d31cc | 2145 | has_active = true; |
9f54cec5 | 2146 | if (!pgpath_busy(pgpath)) { |
be7d31cc | 2147 | busy = false; |
f40c67f0 KU |
2148 | break; |
2149 | } | |
2150 | } | |
2da1610a | 2151 | } |
f40c67f0 | 2152 | |
2da1610a | 2153 | if (!has_active) { |
f40c67f0 KU |
2154 | /* |
2155 | * No active path in this pg, so this pg won't be used and | |
2156 | * the current_pg will be changed at next mapping time. | |
2157 | * We need to try mapping to determine it. | |
2158 | */ | |
be7d31cc | 2159 | busy = false; |
2da1610a | 2160 | } |
f40c67f0 KU |
2161 | |
2162 | return busy; | |
2163 | } | |
2164 | ||
1da177e4 LT |
2165 | /*----------------------------------------------------------------- |
2166 | * Module setup | |
2167 | *---------------------------------------------------------------*/ | |
2168 | static struct target_type multipath_target = { | |
2169 | .name = "multipath", | |
636be424 | 2170 | .version = {1, 14, 0}, |
8c5c1473 SM |
2171 | .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE | |
2172 | DM_TARGET_PASSES_INTEGRITY, | |
1da177e4 LT |
2173 | .module = THIS_MODULE, |
2174 | .ctr = multipath_ctr, | |
2175 | .dtr = multipath_dtr, | |
e5863d9a MS |
2176 | .clone_and_map_rq = multipath_clone_and_map, |
2177 | .release_clone_rq = multipath_release_clone, | |
f40c67f0 | 2178 | .rq_end_io = multipath_end_io, |
76e33fe4 MS |
2179 | .map = multipath_map_bio, |
2180 | .end_io = multipath_end_io_bio, | |
2181 | .presuspend = multipath_presuspend, | |
2182 | .postsuspend = multipath_postsuspend, | |
2183 | .resume = multipath_resume, | |
2184 | .status = multipath_status, | |
2185 | .message = multipath_message, | |
2186 | .prepare_ioctl = multipath_prepare_ioctl, | |
2187 | .iterate_devices = multipath_iterate_devices, | |
2188 | .busy = multipath_busy, | |
2189 | }; | |
2190 | ||
1da177e4 LT |
2191 | static int __init dm_multipath_init(void) |
2192 | { | |
2193 | int r; | |
2194 | ||
4d4d66ab | 2195 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
c557308e | 2196 | if (!kmultipathd) { |
0cd33124 | 2197 | DMERR("failed to create workqueue kmpathd"); |
ff658e9c JT |
2198 | r = -ENOMEM; |
2199 | goto bad_alloc_kmultipathd; | |
c557308e AK |
2200 | } |
2201 | ||
bab7cfc7 CS |
2202 | /* |
2203 | * A separate workqueue is used to handle the device handlers | |
2204 | * to avoid overloading existing workqueue. Overloading the | |
2205 | * old workqueue would also create a bottleneck in the | |
2206 | * path of the storage hardware device activation. | |
2207 | */ | |
4d4d66ab TH |
2208 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
2209 | WQ_MEM_RECLAIM); | |
bab7cfc7 CS |
2210 | if (!kmpath_handlerd) { |
2211 | DMERR("failed to create workqueue kmpath_handlerd"); | |
ff658e9c JT |
2212 | r = -ENOMEM; |
2213 | goto bad_alloc_kmpath_handlerd; | |
bab7cfc7 CS |
2214 | } |
2215 | ||
7e6358d2 | 2216 | r = dm_register_target(&multipath_target); |
2217 | if (r < 0) { | |
2218 | DMERR("request-based register failed %d", r); | |
2219 | r = -EINVAL; | |
2220 | goto bad_register_target; | |
2221 | } | |
2222 | ||
ff658e9c JT |
2223 | return 0; |
2224 | ||
7e6358d2 | 2225 | bad_register_target: |
2226 | destroy_workqueue(kmpath_handlerd); | |
ff658e9c JT |
2227 | bad_alloc_kmpath_handlerd: |
2228 | destroy_workqueue(kmultipathd); | |
2229 | bad_alloc_kmultipathd: | |
1da177e4 LT |
2230 | return r; |
2231 | } | |
2232 | ||
2233 | static void __exit dm_multipath_exit(void) | |
2234 | { | |
bab7cfc7 | 2235 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
2236 | destroy_workqueue(kmultipathd); |
2237 | ||
10d3bd09 | 2238 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
2239 | } |
2240 | ||
1da177e4 LT |
2241 | module_init(dm_multipath_init); |
2242 | module_exit(dm_multipath_exit); | |
2243 | ||
be240ff5 AP |
2244 | module_param_named(queue_if_no_path_timeout_secs, |
2245 | queue_if_no_path_timeout_secs, ulong, S_IRUGO | S_IWUSR); | |
2246 | MODULE_PARM_DESC(queue_if_no_path_timeout_secs, "No available paths queue IO timeout in seconds"); | |
2247 | ||
1da177e4 LT |
2248 | MODULE_DESCRIPTION(DM_NAME " multipath target"); |
2249 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
2250 | MODULE_LICENSE("GPL"); |