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; |
c06dfd12 | 108 | u64 start_time_ns; |
1da177e4 LT |
109 | }; |
110 | ||
111 | typedef int (*action_fn) (struct pgpath *pgpath); | |
112 | ||
bab7cfc7 | 113 | static struct workqueue_struct *kmultipathd, *kmpath_handlerd; |
c4028958 | 114 | static void trigger_event(struct work_struct *work); |
89bfce76 BVA |
115 | static void activate_or_offline_path(struct pgpath *pgpath); |
116 | static void activate_path_work(struct work_struct *work); | |
76e33fe4 | 117 | static void process_queued_bios(struct work_struct *work); |
be240ff5 | 118 | static void queue_if_no_path_timeout_work(struct timer_list *t); |
1da177e4 | 119 | |
518257b1 MS |
120 | /*----------------------------------------------- |
121 | * Multipath state flags. | |
122 | *-----------------------------------------------*/ | |
123 | ||
124 | #define MPATHF_QUEUE_IO 0 /* Must we queue all I/O? */ | |
125 | #define MPATHF_QUEUE_IF_NO_PATH 1 /* Queue I/O if last path fails? */ | |
126 | #define MPATHF_SAVED_QUEUE_IF_NO_PATH 2 /* Saved state during suspension */ | |
127 | #define MPATHF_RETAIN_ATTACHED_HW_HANDLER 3 /* If there's already a hw_handler present, don't change it. */ | |
128 | #define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */ | |
129 | #define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */ | |
130 | #define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */ | |
1da177e4 | 131 | |
374117ad MS |
132 | static bool mpath_double_check_test_bit(int MPATHF_bit, struct multipath *m) |
133 | { | |
134 | bool r = test_bit(MPATHF_bit, &m->flags); | |
135 | ||
136 | if (r) { | |
137 | unsigned long flags; | |
138 | spin_lock_irqsave(&m->lock, flags); | |
139 | r = test_bit(MPATHF_bit, &m->flags); | |
140 | spin_unlock_irqrestore(&m->lock, flags); | |
141 | } | |
142 | ||
143 | return r; | |
144 | } | |
145 | ||
1da177e4 LT |
146 | /*----------------------------------------------- |
147 | * Allocation routines | |
148 | *-----------------------------------------------*/ | |
149 | ||
150 | static struct pgpath *alloc_pgpath(void) | |
151 | { | |
e69fae56 | 152 | struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL); |
1da177e4 | 153 | |
848b8aef MS |
154 | if (!pgpath) |
155 | return NULL; | |
156 | ||
157 | pgpath->is_active = true; | |
1da177e4 LT |
158 | |
159 | return pgpath; | |
160 | } | |
161 | ||
028867ac | 162 | static void free_pgpath(struct pgpath *pgpath) |
1da177e4 LT |
163 | { |
164 | kfree(pgpath); | |
165 | } | |
166 | ||
167 | static struct priority_group *alloc_priority_group(void) | |
168 | { | |
169 | struct priority_group *pg; | |
170 | ||
e69fae56 | 171 | pg = kzalloc(sizeof(*pg), GFP_KERNEL); |
1da177e4 | 172 | |
e69fae56 MM |
173 | if (pg) |
174 | INIT_LIST_HEAD(&pg->pgpaths); | |
1da177e4 LT |
175 | |
176 | return pg; | |
177 | } | |
178 | ||
179 | static void free_pgpaths(struct list_head *pgpaths, struct dm_target *ti) | |
180 | { | |
181 | struct pgpath *pgpath, *tmp; | |
182 | ||
183 | list_for_each_entry_safe(pgpath, tmp, pgpaths, list) { | |
184 | list_del(&pgpath->list); | |
185 | dm_put_device(ti, pgpath->path.dev); | |
186 | free_pgpath(pgpath); | |
187 | } | |
188 | } | |
189 | ||
190 | static void free_priority_group(struct priority_group *pg, | |
191 | struct dm_target *ti) | |
192 | { | |
193 | struct path_selector *ps = &pg->ps; | |
194 | ||
195 | if (ps->type) { | |
196 | ps->type->destroy(ps); | |
197 | dm_put_path_selector(ps->type); | |
198 | } | |
199 | ||
200 | free_pgpaths(&pg->pgpaths, ti); | |
201 | kfree(pg); | |
202 | } | |
203 | ||
e83068a5 | 204 | static struct multipath *alloc_multipath(struct dm_target *ti) |
1da177e4 LT |
205 | { |
206 | struct multipath *m; | |
207 | ||
e69fae56 | 208 | m = kzalloc(sizeof(*m), GFP_KERNEL); |
1da177e4 | 209 | if (m) { |
1da177e4 LT |
210 | INIT_LIST_HEAD(&m->priority_groups); |
211 | spin_lock_init(&m->lock); | |
91e968aa | 212 | atomic_set(&m->nr_valid_paths, 0); |
c4028958 | 213 | INIT_WORK(&m->trigger_event, trigger_event); |
6380f26f | 214 | mutex_init(&m->work_mutex); |
8637a6bf | 215 | |
e83068a5 | 216 | m->queue_mode = DM_TYPE_NONE; |
76e33fe4 | 217 | |
28f16c20 MM |
218 | m->ti = ti; |
219 | ti->private = m; | |
be240ff5 AP |
220 | |
221 | timer_setup(&m->nopath_timer, queue_if_no_path_timeout_work, 0); | |
1da177e4 LT |
222 | } |
223 | ||
224 | return m; | |
225 | } | |
226 | ||
e83068a5 MS |
227 | static int alloc_multipath_stage2(struct dm_target *ti, struct multipath *m) |
228 | { | |
229 | if (m->queue_mode == DM_TYPE_NONE) { | |
953923c0 | 230 | m->queue_mode = DM_TYPE_REQUEST_BASED; |
8d47e659 | 231 | } else if (m->queue_mode == DM_TYPE_BIO_BASED) { |
e83068a5 | 232 | INIT_WORK(&m->process_queued_bios, process_queued_bios); |
8d47e659 MS |
233 | /* |
234 | * bio-based doesn't support any direct scsi_dh management; | |
235 | * it just discovers if a scsi_dh is attached. | |
236 | */ | |
237 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); | |
e83068a5 MS |
238 | } |
239 | ||
240 | dm_table_set_type(ti->table, m->queue_mode); | |
241 | ||
c3736674 MS |
242 | /* |
243 | * Init fields that are only used when a scsi_dh is attached | |
244 | * - must do this unconditionally (really doesn't hurt non-SCSI uses) | |
245 | */ | |
246 | set_bit(MPATHF_QUEUE_IO, &m->flags); | |
247 | atomic_set(&m->pg_init_in_progress, 0); | |
248 | atomic_set(&m->pg_init_count, 0); | |
249 | m->pg_init_delay_msecs = DM_PG_INIT_DELAY_DEFAULT; | |
250 | init_waitqueue_head(&m->pg_init_wait); | |
251 | ||
e83068a5 MS |
252 | return 0; |
253 | } | |
254 | ||
1da177e4 LT |
255 | static void free_multipath(struct multipath *m) |
256 | { | |
257 | struct priority_group *pg, *tmp; | |
1da177e4 LT |
258 | |
259 | list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) { | |
260 | list_del(&pg->list); | |
261 | free_priority_group(pg, m->ti); | |
262 | } | |
263 | ||
cfae5c9b | 264 | kfree(m->hw_handler_name); |
2bfd2e13 | 265 | kfree(m->hw_handler_params); |
d5ffebdd | 266 | mutex_destroy(&m->work_mutex); |
1da177e4 LT |
267 | kfree(m); |
268 | } | |
269 | ||
2eff1924 MS |
270 | static struct dm_mpath_io *get_mpio(union map_info *info) |
271 | { | |
272 | return info->ptr; | |
273 | } | |
274 | ||
bf661be1 MS |
275 | static size_t multipath_per_bio_data_size(void) |
276 | { | |
277 | return sizeof(struct dm_mpath_io) + sizeof(struct dm_bio_details); | |
278 | } | |
279 | ||
76e33fe4 MS |
280 | static struct dm_mpath_io *get_mpio_from_bio(struct bio *bio) |
281 | { | |
bf661be1 | 282 | return dm_per_bio_data(bio, multipath_per_bio_data_size()); |
76e33fe4 MS |
283 | } |
284 | ||
d07a241d | 285 | static struct dm_bio_details *get_bio_details_from_mpio(struct dm_mpath_io *mpio) |
76e33fe4 | 286 | { |
bf661be1 | 287 | /* dm_bio_details is immediately after the dm_mpath_io in bio's per-bio-data */ |
bf661be1 | 288 | void *bio_details = mpio + 1; |
bf661be1 MS |
289 | return bio_details; |
290 | } | |
291 | ||
63f6e6fd | 292 | static void multipath_init_per_bio_data(struct bio *bio, struct dm_mpath_io **mpio_p) |
bf661be1 MS |
293 | { |
294 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); | |
d07a241d | 295 | struct dm_bio_details *bio_details = get_bio_details_from_mpio(mpio); |
76e33fe4 | 296 | |
d0442f80 MS |
297 | mpio->nr_bytes = bio->bi_iter.bi_size; |
298 | mpio->pgpath = NULL; | |
c06dfd12 | 299 | mpio->start_time_ns = 0; |
d0442f80 | 300 | *mpio_p = mpio; |
76e33fe4 | 301 | |
d0442f80 | 302 | dm_bio_record(bio_details, bio); |
76e33fe4 MS |
303 | } |
304 | ||
1da177e4 LT |
305 | /*----------------------------------------------- |
306 | * Path selection | |
307 | *-----------------------------------------------*/ | |
308 | ||
3e9f1be1 | 309 | static int __pg_init_all_paths(struct multipath *m) |
fb612642 KU |
310 | { |
311 | struct pgpath *pgpath; | |
4e2d19e4 | 312 | unsigned long pg_init_delay = 0; |
fb612642 | 313 | |
b194679f BVA |
314 | lockdep_assert_held(&m->lock); |
315 | ||
91e968aa | 316 | if (atomic_read(&m->pg_init_in_progress) || test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) |
3e9f1be1 | 317 | return 0; |
17f4ff45 | 318 | |
91e968aa | 319 | atomic_inc(&m->pg_init_count); |
518257b1 | 320 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
3e9f1be1 HR |
321 | |
322 | /* Check here to reset pg_init_required */ | |
323 | if (!m->current_pg) | |
324 | return 0; | |
325 | ||
518257b1 | 326 | if (test_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags)) |
4e2d19e4 CS |
327 | pg_init_delay = msecs_to_jiffies(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT ? |
328 | m->pg_init_delay_msecs : DM_PG_INIT_DELAY_MSECS); | |
fb612642 KU |
329 | list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) { |
330 | /* Skip failed paths */ | |
331 | if (!pgpath->is_active) | |
332 | continue; | |
4e2d19e4 CS |
333 | if (queue_delayed_work(kmpath_handlerd, &pgpath->activate_path, |
334 | pg_init_delay)) | |
91e968aa | 335 | atomic_inc(&m->pg_init_in_progress); |
fb612642 | 336 | } |
91e968aa | 337 | return atomic_read(&m->pg_init_in_progress); |
fb612642 KU |
338 | } |
339 | ||
c1d7ecf7 | 340 | static int pg_init_all_paths(struct multipath *m) |
1da177e4 | 341 | { |
c1d7ecf7 | 342 | int ret; |
2da1610a MS |
343 | unsigned long flags; |
344 | ||
345 | spin_lock_irqsave(&m->lock, flags); | |
c1d7ecf7 | 346 | ret = __pg_init_all_paths(m); |
2da1610a | 347 | spin_unlock_irqrestore(&m->lock, flags); |
c1d7ecf7 BVA |
348 | |
349 | return ret; | |
2da1610a MS |
350 | } |
351 | ||
352 | static void __switch_pg(struct multipath *m, struct priority_group *pg) | |
353 | { | |
69cea0d4 MS |
354 | lockdep_assert_held(&m->lock); |
355 | ||
2da1610a | 356 | m->current_pg = pg; |
1da177e4 LT |
357 | |
358 | /* Must we initialise the PG first, and queue I/O till it's ready? */ | |
cfae5c9b | 359 | if (m->hw_handler_name) { |
518257b1 MS |
360 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
361 | set_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 362 | } else { |
518257b1 MS |
363 | clear_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
364 | clear_bit(MPATHF_QUEUE_IO, &m->flags); | |
1da177e4 | 365 | } |
c9e45581 | 366 | |
91e968aa | 367 | atomic_set(&m->pg_init_count, 0); |
1da177e4 LT |
368 | } |
369 | ||
2da1610a MS |
370 | static struct pgpath *choose_path_in_pg(struct multipath *m, |
371 | struct priority_group *pg, | |
372 | size_t nr_bytes) | |
1da177e4 | 373 | { |
2da1610a | 374 | unsigned long flags; |
c922d5f7 | 375 | struct dm_path *path; |
2da1610a | 376 | struct pgpath *pgpath; |
1da177e4 | 377 | |
90a4323c | 378 | path = pg->ps.type->select_path(&pg->ps, nr_bytes); |
1da177e4 | 379 | if (!path) |
2da1610a | 380 | return ERR_PTR(-ENXIO); |
1da177e4 | 381 | |
2da1610a | 382 | pgpath = path_to_pgpath(path); |
1da177e4 | 383 | |
506458ef | 384 | if (unlikely(READ_ONCE(m->current_pg) != pg)) { |
2da1610a MS |
385 | /* Only update current_pgpath if pg changed */ |
386 | spin_lock_irqsave(&m->lock, flags); | |
387 | m->current_pgpath = pgpath; | |
388 | __switch_pg(m, pg); | |
389 | spin_unlock_irqrestore(&m->lock, flags); | |
390 | } | |
1da177e4 | 391 | |
2da1610a | 392 | return pgpath; |
1da177e4 LT |
393 | } |
394 | ||
2da1610a | 395 | static struct pgpath *choose_pgpath(struct multipath *m, size_t nr_bytes) |
1da177e4 | 396 | { |
2da1610a | 397 | unsigned long flags; |
1da177e4 | 398 | struct priority_group *pg; |
2da1610a | 399 | struct pgpath *pgpath; |
d19a55cc | 400 | unsigned bypassed = 1; |
1da177e4 | 401 | |
91e968aa | 402 | if (!atomic_read(&m->nr_valid_paths)) { |
69cea0d4 | 403 | spin_lock_irqsave(&m->lock, flags); |
8d47e659 | 404 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
69cea0d4 | 405 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 | 406 | goto failed; |
1f271972 | 407 | } |
1da177e4 LT |
408 | |
409 | /* Were we instructed to switch PG? */ | |
506458ef | 410 | if (READ_ONCE(m->next_pg)) { |
2da1610a | 411 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 | 412 | pg = m->next_pg; |
2da1610a MS |
413 | if (!pg) { |
414 | spin_unlock_irqrestore(&m->lock, flags); | |
415 | goto check_current_pg; | |
416 | } | |
1da177e4 | 417 | m->next_pg = NULL; |
2da1610a MS |
418 | spin_unlock_irqrestore(&m->lock, flags); |
419 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
420 | if (!IS_ERR_OR_NULL(pgpath)) | |
421 | return pgpath; | |
1da177e4 LT |
422 | } |
423 | ||
424 | /* Don't change PG until it has no remaining paths */ | |
2da1610a | 425 | check_current_pg: |
506458ef | 426 | pg = READ_ONCE(m->current_pg); |
2da1610a MS |
427 | if (pg) { |
428 | pgpath = choose_path_in_pg(m, pg, nr_bytes); | |
429 | if (!IS_ERR_OR_NULL(pgpath)) | |
430 | return pgpath; | |
431 | } | |
1da177e4 LT |
432 | |
433 | /* | |
434 | * Loop through priority groups until we find a valid path. | |
435 | * First time we skip PGs marked 'bypassed'. | |
f220fd4e MC |
436 | * Second time we only try the ones we skipped, but set |
437 | * pg_init_delay_retry so we do not hammer controllers. | |
1da177e4 LT |
438 | */ |
439 | do { | |
440 | list_for_each_entry(pg, &m->priority_groups, list) { | |
d19a55cc | 441 | if (pg->bypassed == !!bypassed) |
1da177e4 | 442 | continue; |
2da1610a MS |
443 | pgpath = choose_path_in_pg(m, pg, nr_bytes); |
444 | if (!IS_ERR_OR_NULL(pgpath)) { | |
69cea0d4 MS |
445 | if (!bypassed) { |
446 | spin_lock_irqsave(&m->lock, flags); | |
518257b1 | 447 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); |
69cea0d4 MS |
448 | spin_unlock_irqrestore(&m->lock, flags); |
449 | } | |
2da1610a | 450 | return pgpath; |
f220fd4e | 451 | } |
1da177e4 LT |
452 | } |
453 | } while (bypassed--); | |
454 | ||
455 | failed: | |
2da1610a | 456 | spin_lock_irqsave(&m->lock, flags); |
1da177e4 LT |
457 | m->current_pgpath = NULL; |
458 | m->current_pg = NULL; | |
2da1610a MS |
459 | spin_unlock_irqrestore(&m->lock, flags); |
460 | ||
461 | return NULL; | |
1da177e4 LT |
462 | } |
463 | ||
45e15720 | 464 | /* |
ac75b09f | 465 | * dm_report_EIO() is a macro instead of a function to make pr_debug_ratelimited() |
86331f39 BVA |
466 | * report the function name and line number of the function from which |
467 | * it has been invoked. | |
45e15720 | 468 | */ |
86331f39 | 469 | #define dm_report_EIO(m) \ |
18a482f5 | 470 | do { \ |
ac75b09f | 471 | DMDEBUG_LIMIT("%s: returning EIO; QIFNP = %d; SQIFNP = %d; DNFS = %d", \ |
d4a512ed | 472 | dm_table_device_name((m)->ti->table), \ |
ac75b09f MS |
473 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &(m)->flags), \ |
474 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &(m)->flags), \ | |
475 | dm_noflush_suspending((m)->ti)); \ | |
18a482f5 | 476 | } while (0) |
45e15720 | 477 | |
c1fd0abe MS |
478 | /* |
479 | * Check whether bios must be queued in the device-mapper core rather | |
480 | * than here in the target. | |
c1fd0abe | 481 | */ |
a862e4e2 | 482 | static bool __must_push_back(struct multipath *m) |
c1fd0abe | 483 | { |
a862e4e2 | 484 | return dm_noflush_suspending(m->ti); |
c1fd0abe MS |
485 | } |
486 | ||
c1fd0abe MS |
487 | static bool must_push_back_rq(struct multipath *m) |
488 | { | |
73265f3f MS |
489 | unsigned long flags; |
490 | bool ret; | |
491 | ||
492 | spin_lock_irqsave(&m->lock, flags); | |
493 | ret = (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) || __must_push_back(m)); | |
494 | spin_unlock_irqrestore(&m->lock, flags); | |
495 | ||
496 | return ret; | |
c1fd0abe MS |
497 | } |
498 | ||
36fcffcc | 499 | /* |
76e33fe4 | 500 | * Map cloned requests (request-based multipath) |
36fcffcc | 501 | */ |
eb8db831 CH |
502 | static int multipath_clone_and_map(struct dm_target *ti, struct request *rq, |
503 | union map_info *map_context, | |
504 | struct request **__clone) | |
1da177e4 | 505 | { |
7943bd6d | 506 | struct multipath *m = ti->private; |
eb8db831 | 507 | size_t nr_bytes = blk_rq_bytes(rq); |
1da177e4 | 508 | struct pgpath *pgpath; |
f40c67f0 | 509 | struct block_device *bdev; |
eb8db831 | 510 | struct dm_mpath_io *mpio = get_mpio(map_context); |
7083abbb | 511 | struct request_queue *q; |
eb8db831 | 512 | struct request *clone; |
1da177e4 | 513 | |
1da177e4 | 514 | /* Do we need to select a new pgpath? */ |
506458ef | 515 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 516 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
2da1610a | 517 | pgpath = choose_pgpath(m, nr_bytes); |
1da177e4 | 518 | |
9bf59a61 | 519 | if (!pgpath) { |
c1fd0abe | 520 | if (must_push_back_rq(m)) |
b88efd43 | 521 | return DM_MAPIO_DELAY_REQUEUE; |
18a482f5 | 522 | dm_report_EIO(m); /* Failed */ |
f98e0eb6 | 523 | return DM_MAPIO_KILL; |
374117ad MS |
524 | } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) || |
525 | mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) { | |
459b5401 ML |
526 | pg_init_all_paths(m); |
527 | return DM_MAPIO_DELAY_REQUEUE; | |
9bf59a61 | 528 | } |
6afbc01d | 529 | |
2eb6e1e3 KB |
530 | mpio->pgpath = pgpath; |
531 | mpio->nr_bytes = nr_bytes; | |
532 | ||
9bf59a61 | 533 | bdev = pgpath->path.dev->bdev; |
7083abbb | 534 | q = bdev_get_queue(bdev); |
0bf6d96c | 535 | clone = blk_mq_alloc_request(q, rq->cmd_flags | REQ_NOMERGE, |
ff005a06 | 536 | BLK_MQ_REQ_NOWAIT); |
eb8db831 CH |
537 | if (IS_ERR(clone)) { |
538 | /* EBUSY, ENODEV or EWOULDBLOCK: requeue */ | |
848b8aef | 539 | if (blk_queue_dying(q)) { |
7083abbb BVA |
540 | atomic_inc(&m->pg_init_in_progress); |
541 | activate_or_offline_path(pgpath); | |
050af08f | 542 | return DM_MAPIO_DELAY_REQUEUE; |
7083abbb | 543 | } |
050af08f ML |
544 | |
545 | /* | |
546 | * blk-mq's SCHED_RESTART can cover this requeue, so we | |
547 | * needn't deal with it by DELAY_REQUEUE. More importantly, | |
548 | * we have to return DM_MAPIO_REQUEUE so that blk-mq can | |
549 | * get the queue busy feedback (via BLK_STS_RESOURCE), | |
550 | * otherwise I/O merging can suffer. | |
551 | */ | |
6a23e05c | 552 | return DM_MAPIO_REQUEUE; |
e5863d9a | 553 | } |
eb8db831 | 554 | clone->bio = clone->biotail = NULL; |
eb8db831 CH |
555 | clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; |
556 | *__clone = clone; | |
e5863d9a | 557 | |
9bf59a61 MS |
558 | if (pgpath->pg->ps.type->start_io) |
559 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
560 | &pgpath->path, | |
561 | nr_bytes); | |
2eb6e1e3 | 562 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
563 | } |
564 | ||
5de719e3 YY |
565 | static void multipath_release_clone(struct request *clone, |
566 | union map_info *map_context) | |
e5863d9a | 567 | { |
5de719e3 YY |
568 | if (unlikely(map_context)) { |
569 | /* | |
570 | * non-NULL map_context means caller is still map | |
571 | * method; must undo multipath_clone_and_map() | |
572 | */ | |
573 | struct dm_mpath_io *mpio = get_mpio(map_context); | |
574 | struct pgpath *pgpath = mpio->pgpath; | |
575 | ||
576 | if (pgpath && pgpath->pg->ps.type->end_io) | |
577 | pgpath->pg->ps.type->end_io(&pgpath->pg->ps, | |
578 | &pgpath->path, | |
087615bf GKB |
579 | mpio->nr_bytes, |
580 | clone->io_start_time_ns); | |
5de719e3 YY |
581 | } |
582 | ||
0bf6d96c | 583 | blk_mq_free_request(clone); |
e5863d9a MS |
584 | } |
585 | ||
76e33fe4 MS |
586 | /* |
587 | * Map cloned bios (bio-based multipath) | |
588 | */ | |
0001ec56 | 589 | |
17213ec1 | 590 | static void __multipath_queue_bio(struct multipath *m, struct bio *bio) |
f45f1186 | 591 | { |
f45f1186 | 592 | /* Queue for the daemon to resubmit */ |
f45f1186 MS |
593 | bio_list_add(&m->queued_bios, bio); |
594 | if (!test_bit(MPATHF_QUEUE_IO, &m->flags)) | |
595 | queue_work(kmultipathd, &m->process_queued_bios); | |
17213ec1 MS |
596 | } |
597 | ||
598 | static void multipath_queue_bio(struct multipath *m, struct bio *bio) | |
599 | { | |
600 | unsigned long flags; | |
601 | ||
602 | spin_lock_irqsave(&m->lock, flags); | |
603 | __multipath_queue_bio(m, bio); | |
f45f1186 MS |
604 | spin_unlock_irqrestore(&m->lock, flags); |
605 | } | |
606 | ||
0001ec56 | 607 | static struct pgpath *__map_bio(struct multipath *m, struct bio *bio) |
76e33fe4 | 608 | { |
76e33fe4 MS |
609 | struct pgpath *pgpath; |
610 | unsigned long flags; | |
76e33fe4 MS |
611 | |
612 | /* Do we need to select a new pgpath? */ | |
506458ef | 613 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 614 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
0001ec56 | 615 | pgpath = choose_pgpath(m, bio->bi_iter.bi_size); |
76e33fe4 | 616 | |
17213ec1 | 617 | if (!pgpath) { |
76e33fe4 | 618 | spin_lock_irqsave(&m->lock, flags); |
17213ec1 MS |
619 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { |
620 | __multipath_queue_bio(m, bio); | |
621 | pgpath = ERR_PTR(-EAGAIN); | |
622 | } | |
76e33fe4 | 623 | spin_unlock_irqrestore(&m->lock, flags); |
848b8aef | 624 | |
374117ad MS |
625 | } else if (mpath_double_check_test_bit(MPATHF_QUEUE_IO, m) || |
626 | mpath_double_check_test_bit(MPATHF_PG_INIT_REQUIRED, m)) { | |
f45f1186 | 627 | multipath_queue_bio(m, bio); |
17213ec1 | 628 | pg_init_all_paths(m); |
0001ec56 | 629 | return ERR_PTR(-EAGAIN); |
76e33fe4 MS |
630 | } |
631 | ||
0001ec56 MS |
632 | return pgpath; |
633 | } | |
634 | ||
0001ec56 MS |
635 | static int __multipath_map_bio(struct multipath *m, struct bio *bio, |
636 | struct dm_mpath_io *mpio) | |
637 | { | |
dbaf971c | 638 | struct pgpath *pgpath = __map_bio(m, bio); |
848b8aef | 639 | |
0001ec56 | 640 | if (IS_ERR(pgpath)) |
76e33fe4 | 641 | return DM_MAPIO_SUBMITTED; |
76e33fe4 MS |
642 | |
643 | if (!pgpath) { | |
a862e4e2 | 644 | if (__must_push_back(m)) |
ca5beb76 | 645 | return DM_MAPIO_REQUEUE; |
18a482f5 | 646 | dm_report_EIO(m); |
846785e6 | 647 | return DM_MAPIO_KILL; |
76e33fe4 MS |
648 | } |
649 | ||
650 | mpio->pgpath = pgpath; | |
76e33fe4 | 651 | |
c06dfd12 GKB |
652 | if (dm_ps_use_hr_timer(pgpath->pg->ps.type)) |
653 | mpio->start_time_ns = ktime_get_ns(); | |
654 | ||
4e4cbee9 | 655 | bio->bi_status = 0; |
74d46992 | 656 | bio_set_dev(bio, pgpath->path.dev->bdev); |
1eff9d32 | 657 | bio->bi_opf |= REQ_FAILFAST_TRANSPORT; |
76e33fe4 MS |
658 | |
659 | if (pgpath->pg->ps.type->start_io) | |
660 | pgpath->pg->ps.type->start_io(&pgpath->pg->ps, | |
661 | &pgpath->path, | |
d0442f80 | 662 | mpio->nr_bytes); |
76e33fe4 MS |
663 | return DM_MAPIO_REMAPPED; |
664 | } | |
665 | ||
666 | static int multipath_map_bio(struct dm_target *ti, struct bio *bio) | |
667 | { | |
668 | struct multipath *m = ti->private; | |
bf661be1 MS |
669 | struct dm_mpath_io *mpio = NULL; |
670 | ||
63f6e6fd | 671 | multipath_init_per_bio_data(bio, &mpio); |
76e33fe4 MS |
672 | return __multipath_map_bio(m, bio, mpio); |
673 | } | |
674 | ||
7e48c768 | 675 | static void process_queued_io_list(struct multipath *m) |
76e33fe4 | 676 | { |
953923c0 | 677 | if (m->queue_mode == DM_TYPE_REQUEST_BASED) |
7e48c768 | 678 | dm_mq_kick_requeue_list(dm_table_get_md(m->ti->table)); |
8d47e659 | 679 | else if (m->queue_mode == DM_TYPE_BIO_BASED) |
76e33fe4 MS |
680 | queue_work(kmultipathd, &m->process_queued_bios); |
681 | } | |
682 | ||
683 | static void process_queued_bios(struct work_struct *work) | |
684 | { | |
685 | int r; | |
686 | unsigned long flags; | |
687 | struct bio *bio; | |
688 | struct bio_list bios; | |
689 | struct blk_plug plug; | |
690 | struct multipath *m = | |
691 | container_of(work, struct multipath, process_queued_bios); | |
692 | ||
693 | bio_list_init(&bios); | |
694 | ||
695 | spin_lock_irqsave(&m->lock, flags); | |
696 | ||
697 | if (bio_list_empty(&m->queued_bios)) { | |
698 | spin_unlock_irqrestore(&m->lock, flags); | |
699 | return; | |
700 | } | |
701 | ||
702 | bio_list_merge(&bios, &m->queued_bios); | |
703 | bio_list_init(&m->queued_bios); | |
704 | ||
705 | spin_unlock_irqrestore(&m->lock, flags); | |
706 | ||
707 | blk_start_plug(&plug); | |
708 | while ((bio = bio_list_pop(&bios))) { | |
1836df08 MS |
709 | struct dm_mpath_io *mpio = get_mpio_from_bio(bio); |
710 | dm_bio_restore(get_bio_details_from_mpio(mpio), bio); | |
711 | r = __multipath_map_bio(m, bio, mpio); | |
846785e6 CH |
712 | switch (r) { |
713 | case DM_MAPIO_KILL: | |
4e4cbee9 CH |
714 | bio->bi_status = BLK_STS_IOERR; |
715 | bio_endio(bio); | |
047385b3 | 716 | break; |
846785e6 | 717 | case DM_MAPIO_REQUEUE: |
4e4cbee9 | 718 | bio->bi_status = BLK_STS_DM_REQUEUE; |
76e33fe4 | 719 | bio_endio(bio); |
846785e6 CH |
720 | break; |
721 | case DM_MAPIO_REMAPPED: | |
ed00aabd | 722 | submit_bio_noacct(bio); |
846785e6 | 723 | break; |
8192a0cd | 724 | case DM_MAPIO_SUBMITTED: |
9157c8d3 BVA |
725 | break; |
726 | default: | |
727 | WARN_ONCE(true, "__multipath_map_bio() returned %d\n", r); | |
846785e6 | 728 | } |
76e33fe4 MS |
729 | } |
730 | blk_finish_plug(&plug); | |
731 | } | |
732 | ||
1da177e4 LT |
733 | /* |
734 | * If we run out of usable paths, should we queue I/O or error it? | |
735 | */ | |
be7d31cc | 736 | static int queue_if_no_path(struct multipath *m, bool queue_if_no_path, |
4c3f4838 | 737 | bool save_old_value, const char *caller) |
1da177e4 LT |
738 | { |
739 | unsigned long flags; | |
553ec94c | 740 | bool queue_if_no_path_bit, saved_queue_if_no_path_bit; |
d4a512ed | 741 | const char *dm_dev_name = dm_table_device_name(m->ti->table); |
4c3f4838 MS |
742 | |
743 | DMDEBUG("%s: %s caller=%s queue_if_no_path=%d save_old_value=%d", | |
744 | dm_dev_name, __func__, caller, queue_if_no_path, save_old_value); | |
1da177e4 LT |
745 | |
746 | spin_lock_irqsave(&m->lock, flags); | |
553ec94c MS |
747 | |
748 | queue_if_no_path_bit = test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); | |
749 | saved_queue_if_no_path_bit = test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
750 | ||
751 | if (save_old_value) { | |
752 | if (unlikely(!queue_if_no_path_bit && saved_queue_if_no_path_bit)) { | |
753 | DMERR("%s: QIFNP disabled but saved as enabled, saving again loses state, not saving!", | |
4c3f4838 | 754 | dm_dev_name); |
553ec94c MS |
755 | } else |
756 | assign_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path_bit); | |
757 | } else if (!queue_if_no_path && saved_queue_if_no_path_bit) { | |
758 | /* due to "fail_if_no_path" message, need to honor it. */ | |
759 | clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
760 | } | |
c1fd0abe | 761 | assign_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags, queue_if_no_path); |
553ec94c | 762 | |
4c3f4838 MS |
763 | DMDEBUG("%s: after %s changes; QIFNP = %d; SQIFNP = %d; DNFS = %d", |
764 | dm_dev_name, __func__, | |
765 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags), | |
766 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags), | |
767 | dm_noflush_suspending(m->ti)); | |
768 | ||
1da177e4 LT |
769 | spin_unlock_irqrestore(&m->lock, flags); |
770 | ||
76e33fe4 | 771 | if (!queue_if_no_path) { |
63d832c3 | 772 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 773 | process_queued_io_list(m); |
76e33fe4 | 774 | } |
63d832c3 | 775 | |
1da177e4 LT |
776 | return 0; |
777 | } | |
778 | ||
be240ff5 AP |
779 | /* |
780 | * If the queue_if_no_path timeout fires, turn off queue_if_no_path and | |
781 | * process any queued I/O. | |
782 | */ | |
783 | static void queue_if_no_path_timeout_work(struct timer_list *t) | |
784 | { | |
785 | struct multipath *m = from_timer(m, t, nopath_timer); | |
be240ff5 | 786 | |
d4a512ed MS |
787 | DMWARN("queue_if_no_path timeout on %s, failing queued IO", |
788 | dm_table_device_name(m->ti->table)); | |
4c3f4838 | 789 | queue_if_no_path(m, false, false, __func__); |
be240ff5 AP |
790 | } |
791 | ||
792 | /* | |
793 | * Enable the queue_if_no_path timeout if necessary. | |
794 | * Called with m->lock held. | |
795 | */ | |
796 | static void enable_nopath_timeout(struct multipath *m) | |
797 | { | |
798 | unsigned long queue_if_no_path_timeout = | |
799 | READ_ONCE(queue_if_no_path_timeout_secs) * HZ; | |
800 | ||
801 | lockdep_assert_held(&m->lock); | |
802 | ||
803 | if (queue_if_no_path_timeout > 0 && | |
804 | atomic_read(&m->nr_valid_paths) == 0 && | |
805 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
806 | mod_timer(&m->nopath_timer, | |
807 | jiffies + queue_if_no_path_timeout); | |
808 | } | |
809 | } | |
810 | ||
811 | static void disable_nopath_timeout(struct multipath *m) | |
812 | { | |
813 | del_timer_sync(&m->nopath_timer); | |
814 | } | |
815 | ||
1da177e4 LT |
816 | /* |
817 | * An event is triggered whenever a path is taken out of use. | |
818 | * Includes path failure and PG bypass. | |
819 | */ | |
c4028958 | 820 | static void trigger_event(struct work_struct *work) |
1da177e4 | 821 | { |
c4028958 DH |
822 | struct multipath *m = |
823 | container_of(work, struct multipath, trigger_event); | |
1da177e4 LT |
824 | |
825 | dm_table_event(m->ti->table); | |
826 | } | |
827 | ||
828 | /*----------------------------------------------------------------- | |
829 | * Constructor/argument parsing: | |
830 | * <#multipath feature args> [<arg>]* | |
831 | * <#hw_handler args> [hw_handler [<arg>]*] | |
832 | * <#priority groups> | |
833 | * <initial priority group> | |
834 | * [<selector> <#selector args> [<arg>]* | |
835 | * <#paths> <#per-path selector args> | |
836 | * [<path> [<arg>]* ]+ ]+ | |
837 | *---------------------------------------------------------------*/ | |
498f0103 | 838 | static int parse_path_selector(struct dm_arg_set *as, struct priority_group *pg, |
1da177e4 LT |
839 | struct dm_target *ti) |
840 | { | |
841 | int r; | |
842 | struct path_selector_type *pst; | |
843 | unsigned ps_argc; | |
844 | ||
5916a22b | 845 | static const struct dm_arg _args[] = { |
72d94861 | 846 | {0, 1024, "invalid number of path selector args"}, |
1da177e4 LT |
847 | }; |
848 | ||
498f0103 | 849 | pst = dm_get_path_selector(dm_shift_arg(as)); |
1da177e4 | 850 | if (!pst) { |
72d94861 | 851 | ti->error = "unknown path selector type"; |
1da177e4 LT |
852 | return -EINVAL; |
853 | } | |
854 | ||
498f0103 | 855 | r = dm_read_arg_group(_args, as, &ps_argc, &ti->error); |
371b2e34 MP |
856 | if (r) { |
857 | dm_put_path_selector(pst); | |
1da177e4 | 858 | return -EINVAL; |
371b2e34 | 859 | } |
1da177e4 LT |
860 | |
861 | r = pst->create(&pg->ps, ps_argc, as->argv); | |
862 | if (r) { | |
863 | dm_put_path_selector(pst); | |
72d94861 | 864 | ti->error = "path selector constructor failed"; |
1da177e4 LT |
865 | return r; |
866 | } | |
867 | ||
868 | pg->ps.type = pst; | |
498f0103 | 869 | dm_consume_args(as, ps_argc); |
1da177e4 LT |
870 | |
871 | return 0; | |
872 | } | |
873 | ||
e8f74a0f | 874 | static int setup_scsi_dh(struct block_device *bdev, struct multipath *m, |
b592211c | 875 | const char **attached_handler_name, char **error) |
1da177e4 | 876 | { |
848b8aef | 877 | struct request_queue *q = bdev_get_queue(bdev); |
848b8aef | 878 | int r; |
a58a935d | 879 | |
374117ad | 880 | if (mpath_double_check_test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, m)) { |
1bab0de0 | 881 | retain: |
b592211c | 882 | if (*attached_handler_name) { |
54cd640d | 883 | /* |
884 | * Clear any hw_handler_params associated with a | |
885 | * handler that isn't already attached. | |
886 | */ | |
b592211c | 887 | if (m->hw_handler_name && strcmp(*attached_handler_name, m->hw_handler_name)) { |
54cd640d | 888 | kfree(m->hw_handler_params); |
889 | m->hw_handler_params = NULL; | |
890 | } | |
891 | ||
a58a935d MS |
892 | /* |
893 | * Reset hw_handler_name to match the attached handler | |
a58a935d MS |
894 | * |
895 | * NB. This modifies the table line to show the actual | |
896 | * handler instead of the original table passed in. | |
897 | */ | |
898 | kfree(m->hw_handler_name); | |
b592211c MS |
899 | m->hw_handler_name = *attached_handler_name; |
900 | *attached_handler_name = NULL; | |
a58a935d MS |
901 | } |
902 | } | |
a0cf7ea9 | 903 | |
a58a935d | 904 | if (m->hw_handler_name) { |
a0cf7ea9 HR |
905 | r = scsi_dh_attach(q, m->hw_handler_name); |
906 | if (r == -EBUSY) { | |
168678d7 | 907 | DMINFO("retaining handler on device %pg", bdev); |
1bab0de0 CH |
908 | goto retain; |
909 | } | |
ae11b1b3 | 910 | if (r < 0) { |
848b8aef MS |
911 | *error = "error attaching hardware handler"; |
912 | return r; | |
ae11b1b3 | 913 | } |
2bfd2e13 CS |
914 | |
915 | if (m->hw_handler_params) { | |
916 | r = scsi_dh_set_params(q, m->hw_handler_params); | |
917 | if (r < 0) { | |
848b8aef MS |
918 | *error = "unable to set hardware handler parameters"; |
919 | return r; | |
2bfd2e13 CS |
920 | } |
921 | } | |
ae11b1b3 HR |
922 | } |
923 | ||
848b8aef MS |
924 | return 0; |
925 | } | |
926 | ||
927 | static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps, | |
928 | struct dm_target *ti) | |
929 | { | |
930 | int r; | |
931 | struct pgpath *p; | |
932 | struct multipath *m = ti->private; | |
e8f74a0f | 933 | struct request_queue *q; |
b592211c | 934 | const char *attached_handler_name = NULL; |
848b8aef MS |
935 | |
936 | /* we need at least a path arg */ | |
937 | if (as->argc < 1) { | |
938 | ti->error = "no device given"; | |
939 | return ERR_PTR(-EINVAL); | |
940 | } | |
941 | ||
942 | p = alloc_pgpath(); | |
943 | if (!p) | |
944 | return ERR_PTR(-ENOMEM); | |
945 | ||
946 | r = dm_get_device(ti, dm_shift_arg(as), dm_table_get_mode(ti->table), | |
947 | &p->path.dev); | |
948 | if (r) { | |
949 | ti->error = "error getting device"; | |
950 | goto bad; | |
951 | } | |
952 | ||
e8f74a0f MS |
953 | q = bdev_get_queue(p->path.dev->bdev); |
954 | attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); | |
e457edf0 | 955 | if (attached_handler_name || m->hw_handler_name) { |
848b8aef | 956 | INIT_DELAYED_WORK(&p->activate_path, activate_path_work); |
b592211c | 957 | r = setup_scsi_dh(p->path.dev->bdev, m, &attached_handler_name, &ti->error); |
940bc471 | 958 | kfree(attached_handler_name); |
848b8aef MS |
959 | if (r) { |
960 | dm_put_device(ti, p->path.dev); | |
961 | goto bad; | |
962 | } | |
963 | } | |
964 | ||
1da177e4 LT |
965 | r = ps->type->add_path(ps, &p->path, as->argc, as->argv, &ti->error); |
966 | if (r) { | |
967 | dm_put_device(ti, p->path.dev); | |
968 | goto bad; | |
969 | } | |
970 | ||
971 | return p; | |
1da177e4 LT |
972 | bad: |
973 | free_pgpath(p); | |
01460f35 | 974 | return ERR_PTR(r); |
1da177e4 LT |
975 | } |
976 | ||
498f0103 | 977 | static struct priority_group *parse_priority_group(struct dm_arg_set *as, |
28f16c20 | 978 | struct multipath *m) |
1da177e4 | 979 | { |
5916a22b | 980 | static const struct dm_arg _args[] = { |
72d94861 AK |
981 | {1, 1024, "invalid number of paths"}, |
982 | {0, 1024, "invalid number of selector args"} | |
1da177e4 LT |
983 | }; |
984 | ||
985 | int r; | |
498f0103 | 986 | unsigned i, nr_selector_args, nr_args; |
1da177e4 | 987 | struct priority_group *pg; |
28f16c20 | 988 | struct dm_target *ti = m->ti; |
1da177e4 LT |
989 | |
990 | if (as->argc < 2) { | |
991 | as->argc = 0; | |
01460f35 BM |
992 | ti->error = "not enough priority group arguments"; |
993 | return ERR_PTR(-EINVAL); | |
1da177e4 LT |
994 | } |
995 | ||
996 | pg = alloc_priority_group(); | |
997 | if (!pg) { | |
72d94861 | 998 | ti->error = "couldn't allocate priority group"; |
01460f35 | 999 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
1000 | } |
1001 | pg->m = m; | |
1002 | ||
1003 | r = parse_path_selector(as, pg, ti); | |
1004 | if (r) | |
1005 | goto bad; | |
1006 | ||
1007 | /* | |
1008 | * read the paths | |
1009 | */ | |
498f0103 | 1010 | r = dm_read_arg(_args, as, &pg->nr_pgpaths, &ti->error); |
1da177e4 LT |
1011 | if (r) |
1012 | goto bad; | |
1013 | ||
498f0103 | 1014 | r = dm_read_arg(_args + 1, as, &nr_selector_args, &ti->error); |
1da177e4 LT |
1015 | if (r) |
1016 | goto bad; | |
1017 | ||
498f0103 | 1018 | nr_args = 1 + nr_selector_args; |
1da177e4 LT |
1019 | for (i = 0; i < pg->nr_pgpaths; i++) { |
1020 | struct pgpath *pgpath; | |
498f0103 | 1021 | struct dm_arg_set path_args; |
1da177e4 | 1022 | |
498f0103 | 1023 | if (as->argc < nr_args) { |
148acff6 | 1024 | ti->error = "not enough path parameters"; |
6bbf79a1 | 1025 | r = -EINVAL; |
1da177e4 | 1026 | goto bad; |
148acff6 | 1027 | } |
1da177e4 | 1028 | |
498f0103 | 1029 | path_args.argc = nr_args; |
1da177e4 LT |
1030 | path_args.argv = as->argv; |
1031 | ||
1032 | pgpath = parse_path(&path_args, &pg->ps, ti); | |
01460f35 BM |
1033 | if (IS_ERR(pgpath)) { |
1034 | r = PTR_ERR(pgpath); | |
1da177e4 | 1035 | goto bad; |
01460f35 | 1036 | } |
1da177e4 LT |
1037 | |
1038 | pgpath->pg = pg; | |
1039 | list_add_tail(&pgpath->list, &pg->pgpaths); | |
498f0103 | 1040 | dm_consume_args(as, nr_args); |
1da177e4 LT |
1041 | } |
1042 | ||
1043 | return pg; | |
1044 | ||
1045 | bad: | |
1046 | free_priority_group(pg, ti); | |
01460f35 | 1047 | return ERR_PTR(r); |
1da177e4 LT |
1048 | } |
1049 | ||
498f0103 | 1050 | static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) |
1da177e4 | 1051 | { |
1da177e4 | 1052 | unsigned hw_argc; |
2bfd2e13 | 1053 | int ret; |
28f16c20 | 1054 | struct dm_target *ti = m->ti; |
1da177e4 | 1055 | |
5916a22b | 1056 | static const struct dm_arg _args[] = { |
72d94861 | 1057 | {0, 1024, "invalid number of hardware handler args"}, |
1da177e4 LT |
1058 | }; |
1059 | ||
498f0103 | 1060 | if (dm_read_arg_group(_args, as, &hw_argc, &ti->error)) |
1da177e4 LT |
1061 | return -EINVAL; |
1062 | ||
1063 | if (!hw_argc) | |
1064 | return 0; | |
1065 | ||
8d47e659 | 1066 | if (m->queue_mode == DM_TYPE_BIO_BASED) { |
76e33fe4 MS |
1067 | dm_consume_args(as, hw_argc); |
1068 | DMERR("bio-based multipath doesn't allow hardware handler args"); | |
1069 | return 0; | |
1070 | } | |
1071 | ||
498f0103 | 1072 | m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); |
f97dc421 | 1073 | if (!m->hw_handler_name) |
1074 | return -EINVAL; | |
14e98c5c | 1075 | |
2bfd2e13 CS |
1076 | if (hw_argc > 1) { |
1077 | char *p; | |
1078 | int i, j, len = 4; | |
1079 | ||
1080 | for (i = 0; i <= hw_argc - 2; i++) | |
1081 | len += strlen(as->argv[i]) + 1; | |
1082 | p = m->hw_handler_params = kzalloc(len, GFP_KERNEL); | |
1083 | if (!p) { | |
1084 | ti->error = "memory allocation failed"; | |
1085 | ret = -ENOMEM; | |
1086 | goto fail; | |
1087 | } | |
1088 | j = sprintf(p, "%d", hw_argc - 1); | |
1089 | for (i = 0, p+=j+1; i <= hw_argc - 2; i++, p+=j+1) | |
1090 | j = sprintf(p, "%s", as->argv[i]); | |
1091 | } | |
498f0103 | 1092 | dm_consume_args(as, hw_argc - 1); |
1da177e4 LT |
1093 | |
1094 | return 0; | |
2bfd2e13 CS |
1095 | fail: |
1096 | kfree(m->hw_handler_name); | |
1097 | m->hw_handler_name = NULL; | |
1098 | return ret; | |
1da177e4 LT |
1099 | } |
1100 | ||
498f0103 | 1101 | static int parse_features(struct dm_arg_set *as, struct multipath *m) |
1da177e4 LT |
1102 | { |
1103 | int r; | |
1104 | unsigned argc; | |
28f16c20 | 1105 | struct dm_target *ti = m->ti; |
498f0103 | 1106 | const char *arg_name; |
1da177e4 | 1107 | |
5916a22b | 1108 | static const struct dm_arg _args[] = { |
e83068a5 | 1109 | {0, 8, "invalid number of feature args"}, |
c9e45581 | 1110 | {1, 50, "pg_init_retries must be between 1 and 50"}, |
4e2d19e4 | 1111 | {0, 60000, "pg_init_delay_msecs must be between 0 and 60000"}, |
1da177e4 LT |
1112 | }; |
1113 | ||
498f0103 | 1114 | r = dm_read_arg_group(_args, as, &argc, &ti->error); |
1da177e4 LT |
1115 | if (r) |
1116 | return -EINVAL; | |
1117 | ||
1118 | if (!argc) | |
1119 | return 0; | |
1120 | ||
c9e45581 | 1121 | do { |
498f0103 | 1122 | arg_name = dm_shift_arg(as); |
c9e45581 DW |
1123 | argc--; |
1124 | ||
498f0103 | 1125 | if (!strcasecmp(arg_name, "queue_if_no_path")) { |
4c3f4838 | 1126 | r = queue_if_no_path(m, true, false, __func__); |
c9e45581 DW |
1127 | continue; |
1128 | } | |
1129 | ||
a58a935d | 1130 | if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { |
518257b1 | 1131 | set_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags); |
a58a935d MS |
1132 | continue; |
1133 | } | |
1134 | ||
498f0103 | 1135 | if (!strcasecmp(arg_name, "pg_init_retries") && |
c9e45581 | 1136 | (argc >= 1)) { |
498f0103 | 1137 | r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); |
c9e45581 DW |
1138 | argc--; |
1139 | continue; | |
1140 | } | |
1141 | ||
498f0103 | 1142 | if (!strcasecmp(arg_name, "pg_init_delay_msecs") && |
4e2d19e4 | 1143 | (argc >= 1)) { |
498f0103 | 1144 | r = dm_read_arg(_args + 2, as, &m->pg_init_delay_msecs, &ti->error); |
4e2d19e4 CS |
1145 | argc--; |
1146 | continue; | |
1147 | } | |
1148 | ||
e83068a5 MS |
1149 | if (!strcasecmp(arg_name, "queue_mode") && |
1150 | (argc >= 1)) { | |
1151 | const char *queue_mode_name = dm_shift_arg(as); | |
1152 | ||
1153 | if (!strcasecmp(queue_mode_name, "bio")) | |
1154 | m->queue_mode = DM_TYPE_BIO_BASED; | |
953923c0 MS |
1155 | else if (!strcasecmp(queue_mode_name, "rq") || |
1156 | !strcasecmp(queue_mode_name, "mq")) | |
e83068a5 | 1157 | m->queue_mode = DM_TYPE_REQUEST_BASED; |
e83068a5 MS |
1158 | else { |
1159 | ti->error = "Unknown 'queue_mode' requested"; | |
1160 | r = -EINVAL; | |
1161 | } | |
1162 | argc--; | |
1163 | continue; | |
1164 | } | |
1165 | ||
1da177e4 | 1166 | ti->error = "Unrecognised multipath feature request"; |
c9e45581 DW |
1167 | r = -EINVAL; |
1168 | } while (argc && !r); | |
1169 | ||
1170 | return r; | |
1da177e4 LT |
1171 | } |
1172 | ||
e83068a5 | 1173 | static int multipath_ctr(struct dm_target *ti, unsigned argc, char **argv) |
1da177e4 | 1174 | { |
498f0103 | 1175 | /* target arguments */ |
5916a22b | 1176 | static const struct dm_arg _args[] = { |
a490a07a MS |
1177 | {0, 1024, "invalid number of priority groups"}, |
1178 | {0, 1024, "invalid initial priority group number"}, | |
1da177e4 LT |
1179 | }; |
1180 | ||
1181 | int r; | |
1182 | struct multipath *m; | |
498f0103 | 1183 | struct dm_arg_set as; |
1da177e4 LT |
1184 | unsigned pg_count = 0; |
1185 | unsigned next_pg_num; | |
be240ff5 | 1186 | unsigned long flags; |
1da177e4 LT |
1187 | |
1188 | as.argc = argc; | |
1189 | as.argv = argv; | |
1190 | ||
e83068a5 | 1191 | m = alloc_multipath(ti); |
1da177e4 | 1192 | if (!m) { |
72d94861 | 1193 | ti->error = "can't allocate multipath"; |
1da177e4 LT |
1194 | return -EINVAL; |
1195 | } | |
1196 | ||
28f16c20 | 1197 | r = parse_features(&as, m); |
1da177e4 LT |
1198 | if (r) |
1199 | goto bad; | |
1200 | ||
e83068a5 MS |
1201 | r = alloc_multipath_stage2(ti, m); |
1202 | if (r) | |
1203 | goto bad; | |
1204 | ||
28f16c20 | 1205 | r = parse_hw_handler(&as, m); |
1da177e4 LT |
1206 | if (r) |
1207 | goto bad; | |
1208 | ||
498f0103 | 1209 | r = dm_read_arg(_args, &as, &m->nr_priority_groups, &ti->error); |
1da177e4 LT |
1210 | if (r) |
1211 | goto bad; | |
1212 | ||
498f0103 | 1213 | r = dm_read_arg(_args + 1, &as, &next_pg_num, &ti->error); |
1da177e4 LT |
1214 | if (r) |
1215 | goto bad; | |
1216 | ||
a490a07a MS |
1217 | if ((!m->nr_priority_groups && next_pg_num) || |
1218 | (m->nr_priority_groups && !next_pg_num)) { | |
1219 | ti->error = "invalid initial priority group"; | |
1220 | r = -EINVAL; | |
1221 | goto bad; | |
1222 | } | |
1223 | ||
1da177e4 LT |
1224 | /* parse the priority groups */ |
1225 | while (as.argc) { | |
1226 | struct priority_group *pg; | |
91e968aa | 1227 | unsigned nr_valid_paths = atomic_read(&m->nr_valid_paths); |
1da177e4 | 1228 | |
28f16c20 | 1229 | pg = parse_priority_group(&as, m); |
01460f35 BM |
1230 | if (IS_ERR(pg)) { |
1231 | r = PTR_ERR(pg); | |
1da177e4 LT |
1232 | goto bad; |
1233 | } | |
1234 | ||
91e968aa MS |
1235 | nr_valid_paths += pg->nr_pgpaths; |
1236 | atomic_set(&m->nr_valid_paths, nr_valid_paths); | |
1237 | ||
1da177e4 LT |
1238 | list_add_tail(&pg->list, &m->priority_groups); |
1239 | pg_count++; | |
1240 | pg->pg_num = pg_count; | |
1241 | if (!--next_pg_num) | |
1242 | m->next_pg = pg; | |
1243 | } | |
1244 | ||
1245 | if (pg_count != m->nr_priority_groups) { | |
72d94861 | 1246 | ti->error = "priority group count mismatch"; |
1da177e4 LT |
1247 | r = -EINVAL; |
1248 | goto bad; | |
1249 | } | |
1250 | ||
be240ff5 AP |
1251 | spin_lock_irqsave(&m->lock, flags); |
1252 | enable_nopath_timeout(m); | |
1253 | spin_unlock_irqrestore(&m->lock, flags); | |
1254 | ||
55a62eef AK |
1255 | ti->num_flush_bios = 1; |
1256 | ti->num_discard_bios = 1; | |
ac62d620 | 1257 | ti->num_write_zeroes_bios = 1; |
8d47e659 | 1258 | if (m->queue_mode == DM_TYPE_BIO_BASED) |
bf661be1 | 1259 | ti->per_io_data_size = multipath_per_bio_data_size(); |
eb8db831 | 1260 | else |
8637a6bf | 1261 | ti->per_io_data_size = sizeof(struct dm_mpath_io); |
8627921f | 1262 | |
1da177e4 LT |
1263 | return 0; |
1264 | ||
1265 | bad: | |
1266 | free_multipath(m); | |
1267 | return r; | |
1268 | } | |
1269 | ||
2bded7bd KU |
1270 | static void multipath_wait_for_pg_init_completion(struct multipath *m) |
1271 | { | |
9f4c3f87 | 1272 | DEFINE_WAIT(wait); |
2bded7bd KU |
1273 | |
1274 | while (1) { | |
9f4c3f87 | 1275 | prepare_to_wait(&m->pg_init_wait, &wait, TASK_UNINTERRUPTIBLE); |
2bded7bd | 1276 | |
91e968aa | 1277 | if (!atomic_read(&m->pg_init_in_progress)) |
2bded7bd | 1278 | break; |
2bded7bd KU |
1279 | |
1280 | io_schedule(); | |
1281 | } | |
9f4c3f87 | 1282 | finish_wait(&m->pg_init_wait, &wait); |
2bded7bd KU |
1283 | } |
1284 | ||
1285 | static void flush_multipath_work(struct multipath *m) | |
1da177e4 | 1286 | { |
848b8aef | 1287 | if (m->hw_handler_name) { |
c322ee93 MS |
1288 | unsigned long flags; |
1289 | ||
1290 | if (!atomic_read(&m->pg_init_in_progress)) | |
1291 | goto skip; | |
1292 | ||
1293 | spin_lock_irqsave(&m->lock, flags); | |
1294 | if (atomic_read(&m->pg_init_in_progress) && | |
1295 | !test_and_set_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) { | |
1296 | spin_unlock_irqrestore(&m->lock, flags); | |
848b8aef | 1297 | |
935fcc56 | 1298 | flush_workqueue(kmpath_handlerd); |
c322ee93 | 1299 | multipath_wait_for_pg_init_completion(m); |
848b8aef | 1300 | |
c322ee93 MS |
1301 | spin_lock_irqsave(&m->lock, flags); |
1302 | clear_bit(MPATHF_PG_INIT_DISABLED, &m->flags); | |
1303 | } | |
1304 | spin_unlock_irqrestore(&m->lock, flags); | |
848b8aef | 1305 | } |
c322ee93 | 1306 | skip: |
935fcc56 | 1307 | if (m->queue_mode == DM_TYPE_BIO_BASED) |
1308 | flush_work(&m->process_queued_bios); | |
43829731 | 1309 | flush_work(&m->trigger_event); |
6df400ab KU |
1310 | } |
1311 | ||
1312 | static void multipath_dtr(struct dm_target *ti) | |
1313 | { | |
1314 | struct multipath *m = ti->private; | |
1315 | ||
be240ff5 | 1316 | disable_nopath_timeout(m); |
2bded7bd | 1317 | flush_multipath_work(m); |
1da177e4 LT |
1318 | free_multipath(m); |
1319 | } | |
1320 | ||
1da177e4 LT |
1321 | /* |
1322 | * Take a path out of use. | |
1323 | */ | |
1324 | static int fail_path(struct pgpath *pgpath) | |
1325 | { | |
1326 | unsigned long flags; | |
1327 | struct multipath *m = pgpath->pg->m; | |
1328 | ||
1329 | spin_lock_irqsave(&m->lock, flags); | |
1330 | ||
6680073d | 1331 | if (!pgpath->is_active) |
1da177e4 LT |
1332 | goto out; |
1333 | ||
04867370 | 1334 | DMWARN("%s: Failing path %s.", |
d4a512ed | 1335 | dm_table_device_name(m->ti->table), |
04867370 | 1336 | pgpath->path.dev->name); |
1da177e4 LT |
1337 | |
1338 | pgpath->pg->ps.type->fail_path(&pgpath->pg->ps, &pgpath->path); | |
be7d31cc | 1339 | pgpath->is_active = false; |
1da177e4 LT |
1340 | pgpath->fail_count++; |
1341 | ||
91e968aa | 1342 | atomic_dec(&m->nr_valid_paths); |
1da177e4 LT |
1343 | |
1344 | if (pgpath == m->current_pgpath) | |
1345 | m->current_pgpath = NULL; | |
1346 | ||
b15546f9 | 1347 | dm_path_uevent(DM_UEVENT_PATH_FAILED, m->ti, |
91e968aa | 1348 | pgpath->path.dev->name, atomic_read(&m->nr_valid_paths)); |
b15546f9 | 1349 | |
fe9cf30e | 1350 | schedule_work(&m->trigger_event); |
1da177e4 | 1351 | |
be240ff5 AP |
1352 | enable_nopath_timeout(m); |
1353 | ||
1da177e4 LT |
1354 | out: |
1355 | spin_unlock_irqrestore(&m->lock, flags); | |
1356 | ||
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | /* | |
1361 | * Reinstate a previously-failed path | |
1362 | */ | |
1363 | static int reinstate_path(struct pgpath *pgpath) | |
1364 | { | |
63d832c3 | 1365 | int r = 0, run_queue = 0; |
1da177e4 LT |
1366 | unsigned long flags; |
1367 | struct multipath *m = pgpath->pg->m; | |
91e968aa | 1368 | unsigned nr_valid_paths; |
1da177e4 LT |
1369 | |
1370 | spin_lock_irqsave(&m->lock, flags); | |
1371 | ||
6680073d | 1372 | if (pgpath->is_active) |
1da177e4 LT |
1373 | goto out; |
1374 | ||
04867370 | 1375 | DMWARN("%s: Reinstating path %s.", |
d4a512ed | 1376 | dm_table_device_name(m->ti->table), |
04867370 | 1377 | pgpath->path.dev->name); |
1da177e4 LT |
1378 | |
1379 | r = pgpath->pg->ps.type->reinstate_path(&pgpath->pg->ps, &pgpath->path); | |
1380 | if (r) | |
1381 | goto out; | |
1382 | ||
be7d31cc | 1383 | pgpath->is_active = true; |
1da177e4 | 1384 | |
91e968aa MS |
1385 | nr_valid_paths = atomic_inc_return(&m->nr_valid_paths); |
1386 | if (nr_valid_paths == 1) { | |
e54f77dd | 1387 | m->current_pgpath = NULL; |
63d832c3 | 1388 | run_queue = 1; |
e54f77dd | 1389 | } else if (m->hw_handler_name && (m->current_pg == pgpath->pg)) { |
4e2d19e4 | 1390 | if (queue_work(kmpath_handlerd, &pgpath->activate_path.work)) |
91e968aa | 1391 | atomic_inc(&m->pg_init_in_progress); |
e54f77dd | 1392 | } |
1da177e4 | 1393 | |
b15546f9 | 1394 | dm_path_uevent(DM_UEVENT_PATH_REINSTATED, m->ti, |
91e968aa | 1395 | pgpath->path.dev->name, nr_valid_paths); |
b15546f9 | 1396 | |
fe9cf30e | 1397 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1398 | |
1399 | out: | |
1400 | spin_unlock_irqrestore(&m->lock, flags); | |
76e33fe4 | 1401 | if (run_queue) { |
63d832c3 | 1402 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 1403 | process_queued_io_list(m); |
76e33fe4 | 1404 | } |
1da177e4 | 1405 | |
be240ff5 AP |
1406 | if (pgpath->is_active) |
1407 | disable_nopath_timeout(m); | |
1408 | ||
1da177e4 LT |
1409 | return r; |
1410 | } | |
1411 | ||
1412 | /* | |
1413 | * Fail or reinstate all paths that match the provided struct dm_dev. | |
1414 | */ | |
1415 | static int action_dev(struct multipath *m, struct dm_dev *dev, | |
1416 | action_fn action) | |
1417 | { | |
19040c0b | 1418 | int r = -EINVAL; |
1da177e4 LT |
1419 | struct pgpath *pgpath; |
1420 | struct priority_group *pg; | |
1421 | ||
1422 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1423 | list_for_each_entry(pgpath, &pg->pgpaths, list) { | |
1424 | if (pgpath->path.dev == dev) | |
1425 | r = action(pgpath); | |
1426 | } | |
1427 | } | |
1428 | ||
1429 | return r; | |
1430 | } | |
1431 | ||
1432 | /* | |
1433 | * Temporarily try to avoid having to use the specified PG | |
1434 | */ | |
1435 | static void bypass_pg(struct multipath *m, struct priority_group *pg, | |
be7d31cc | 1436 | bool bypassed) |
1da177e4 LT |
1437 | { |
1438 | unsigned long flags; | |
1439 | ||
1440 | spin_lock_irqsave(&m->lock, flags); | |
1441 | ||
1442 | pg->bypassed = bypassed; | |
1443 | m->current_pgpath = NULL; | |
1444 | m->current_pg = NULL; | |
1445 | ||
1446 | spin_unlock_irqrestore(&m->lock, flags); | |
1447 | ||
fe9cf30e | 1448 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1449 | } |
1450 | ||
1451 | /* | |
1452 | * Switch to using the specified PG from the next I/O that gets mapped | |
1453 | */ | |
1454 | static int switch_pg_num(struct multipath *m, const char *pgstr) | |
1455 | { | |
1456 | struct priority_group *pg; | |
1457 | unsigned pgnum; | |
1458 | unsigned long flags; | |
31998ef1 | 1459 | char dummy; |
1da177e4 | 1460 | |
31998ef1 | 1461 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1462 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1463 | DMWARN("invalid PG number supplied to switch_pg_num"); |
1464 | return -EINVAL; | |
1465 | } | |
1466 | ||
1467 | spin_lock_irqsave(&m->lock, flags); | |
1468 | list_for_each_entry(pg, &m->priority_groups, list) { | |
be7d31cc | 1469 | pg->bypassed = false; |
1da177e4 LT |
1470 | if (--pgnum) |
1471 | continue; | |
1472 | ||
1473 | m->current_pgpath = NULL; | |
1474 | m->current_pg = NULL; | |
1475 | m->next_pg = pg; | |
1476 | } | |
1477 | spin_unlock_irqrestore(&m->lock, flags); | |
1478 | ||
fe9cf30e | 1479 | schedule_work(&m->trigger_event); |
1da177e4 LT |
1480 | return 0; |
1481 | } | |
1482 | ||
1483 | /* | |
1484 | * Set/clear bypassed status of a PG. | |
1485 | * PGs are numbered upwards from 1 in the order they were declared. | |
1486 | */ | |
be7d31cc | 1487 | static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed) |
1da177e4 LT |
1488 | { |
1489 | struct priority_group *pg; | |
1490 | unsigned pgnum; | |
31998ef1 | 1491 | char dummy; |
1da177e4 | 1492 | |
31998ef1 | 1493 | if (!pgstr || (sscanf(pgstr, "%u%c", &pgnum, &dummy) != 1) || !pgnum || |
cc5bd925 | 1494 | !m->nr_priority_groups || (pgnum > m->nr_priority_groups)) { |
1da177e4 LT |
1495 | DMWARN("invalid PG number supplied to bypass_pg"); |
1496 | return -EINVAL; | |
1497 | } | |
1498 | ||
1499 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1500 | if (!--pgnum) | |
1501 | break; | |
1502 | } | |
1503 | ||
1504 | bypass_pg(m, pg, bypassed); | |
1505 | return 0; | |
1506 | } | |
1507 | ||
c9e45581 DW |
1508 | /* |
1509 | * Should we retry pg_init immediately? | |
1510 | */ | |
be7d31cc | 1511 | static bool pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath) |
c9e45581 DW |
1512 | { |
1513 | unsigned long flags; | |
be7d31cc | 1514 | bool limit_reached = false; |
c9e45581 DW |
1515 | |
1516 | spin_lock_irqsave(&m->lock, flags); | |
1517 | ||
91e968aa MS |
1518 | if (atomic_read(&m->pg_init_count) <= m->pg_init_retries && |
1519 | !test_bit(MPATHF_PG_INIT_DISABLED, &m->flags)) | |
518257b1 | 1520 | set_bit(MPATHF_PG_INIT_REQUIRED, &m->flags); |
c9e45581 | 1521 | else |
be7d31cc | 1522 | limit_reached = true; |
c9e45581 DW |
1523 | |
1524 | spin_unlock_irqrestore(&m->lock, flags); | |
1525 | ||
1526 | return limit_reached; | |
1527 | } | |
1528 | ||
3ae31f6a | 1529 | static void pg_init_done(void *data, int errors) |
cfae5c9b | 1530 | { |
83c0d5d5 | 1531 | struct pgpath *pgpath = data; |
cfae5c9b CS |
1532 | struct priority_group *pg = pgpath->pg; |
1533 | struct multipath *m = pg->m; | |
1534 | unsigned long flags; | |
be7d31cc | 1535 | bool delay_retry = false; |
cfae5c9b CS |
1536 | |
1537 | /* device or driver problems */ | |
1538 | switch (errors) { | |
1539 | case SCSI_DH_OK: | |
1540 | break; | |
1541 | case SCSI_DH_NOSYS: | |
1542 | if (!m->hw_handler_name) { | |
1543 | errors = 0; | |
1544 | break; | |
1545 | } | |
f7b934c8 MB |
1546 | DMERR("Could not failover the device: Handler scsi_dh_%s " |
1547 | "Error %d.", m->hw_handler_name, errors); | |
cfae5c9b CS |
1548 | /* |
1549 | * Fail path for now, so we do not ping pong | |
1550 | */ | |
1551 | fail_path(pgpath); | |
1552 | break; | |
1553 | case SCSI_DH_DEV_TEMP_BUSY: | |
1554 | /* | |
1555 | * Probably doing something like FW upgrade on the | |
1556 | * controller so try the other pg. | |
1557 | */ | |
be7d31cc | 1558 | bypass_pg(m, pg, true); |
cfae5c9b | 1559 | break; |
cfae5c9b | 1560 | case SCSI_DH_RETRY: |
4e2d19e4 | 1561 | /* Wait before retrying. */ |
4ecc5081 | 1562 | delay_retry = true; |
df561f66 | 1563 | fallthrough; |
cfae5c9b CS |
1564 | case SCSI_DH_IMM_RETRY: |
1565 | case SCSI_DH_RES_TEMP_UNAVAIL: | |
1566 | if (pg_init_limit_reached(m, pgpath)) | |
1567 | fail_path(pgpath); | |
1568 | errors = 0; | |
1569 | break; | |
ec31f3f7 | 1570 | case SCSI_DH_DEV_OFFLINED: |
cfae5c9b CS |
1571 | default: |
1572 | /* | |
1573 | * We probably do not want to fail the path for a device | |
1574 | * error, but this is what the old dm did. In future | |
1575 | * patches we can do more advanced handling. | |
1576 | */ | |
1577 | fail_path(pgpath); | |
1578 | } | |
1579 | ||
1580 | spin_lock_irqsave(&m->lock, flags); | |
1581 | if (errors) { | |
e54f77dd CS |
1582 | if (pgpath == m->current_pgpath) { |
1583 | DMERR("Could not failover device. Error %d.", errors); | |
1584 | m->current_pgpath = NULL; | |
1585 | m->current_pg = NULL; | |
1586 | } | |
518257b1 | 1587 | } else if (!test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
be7d31cc | 1588 | pg->bypassed = false; |
cfae5c9b | 1589 | |
91e968aa | 1590 | if (atomic_dec_return(&m->pg_init_in_progress) > 0) |
d0259bf0 KU |
1591 | /* Activations of other paths are still on going */ |
1592 | goto out; | |
1593 | ||
518257b1 MS |
1594 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) { |
1595 | if (delay_retry) | |
1596 | set_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1597 | else | |
1598 | clear_bit(MPATHF_PG_INIT_DELAY_RETRY, &m->flags); | |
1599 | ||
3e9f1be1 HR |
1600 | if (__pg_init_all_paths(m)) |
1601 | goto out; | |
1602 | } | |
518257b1 | 1603 | clear_bit(MPATHF_QUEUE_IO, &m->flags); |
d0259bf0 | 1604 | |
7e48c768 | 1605 | process_queued_io_list(m); |
76e33fe4 | 1606 | |
2bded7bd KU |
1607 | /* |
1608 | * Wake up any thread waiting to suspend. | |
1609 | */ | |
1610 | wake_up(&m->pg_init_wait); | |
1611 | ||
d0259bf0 | 1612 | out: |
cfae5c9b CS |
1613 | spin_unlock_irqrestore(&m->lock, flags); |
1614 | } | |
1615 | ||
89bfce76 | 1616 | static void activate_or_offline_path(struct pgpath *pgpath) |
bab7cfc7 | 1617 | { |
f10e06b7 | 1618 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); |
bab7cfc7 | 1619 | |
f10e06b7 MS |
1620 | if (pgpath->is_active && !blk_queue_dying(q)) |
1621 | scsi_dh_activate(q, pg_init_done, pgpath); | |
3a017509 HR |
1622 | else |
1623 | pg_init_done(pgpath, SCSI_DH_DEV_OFFLINED); | |
bab7cfc7 CS |
1624 | } |
1625 | ||
89bfce76 BVA |
1626 | static void activate_path_work(struct work_struct *work) |
1627 | { | |
1628 | struct pgpath *pgpath = | |
1629 | container_of(work, struct pgpath, activate_path.work); | |
1630 | ||
1631 | activate_or_offline_path(pgpath); | |
1632 | } | |
1633 | ||
b79f10ee | 1634 | static int multipath_end_io(struct dm_target *ti, struct request *clone, |
2a842aca | 1635 | blk_status_t error, union map_info *map_context) |
1da177e4 | 1636 | { |
b79f10ee CH |
1637 | struct dm_mpath_io *mpio = get_mpio(map_context); |
1638 | struct pgpath *pgpath = mpio->pgpath; | |
7ed8578a | 1639 | int r = DM_ENDIO_DONE; |
b79f10ee | 1640 | |
f40c67f0 KU |
1641 | /* |
1642 | * We don't queue any clone request inside the multipath target | |
1643 | * during end I/O handling, since those clone requests don't have | |
1644 | * bio clones. If we queue them inside the multipath target, | |
1645 | * we need to make bio clones, that requires memory allocation. | |
4cc96131 | 1646 | * (See drivers/md/dm-rq.c:end_clone_bio() about why the clone requests |
f40c67f0 KU |
1647 | * don't have bio clones.) |
1648 | * Instead of queueing the clone request here, we queue the original | |
1649 | * request into dm core, which will remake a clone request and | |
1650 | * clone bios for it and resubmit it later. | |
1651 | */ | |
a1275677 | 1652 | if (error && blk_path_error(error)) { |
b79f10ee | 1653 | struct multipath *m = ti->private; |
1da177e4 | 1654 | |
ac514ffc MS |
1655 | if (error == BLK_STS_RESOURCE) |
1656 | r = DM_ENDIO_DELAY_REQUEUE; | |
1657 | else | |
1658 | r = DM_ENDIO_REQUEUE; | |
1da177e4 | 1659 | |
b79f10ee CH |
1660 | if (pgpath) |
1661 | fail_path(pgpath); | |
1da177e4 | 1662 | |
73265f3f | 1663 | if (!atomic_read(&m->nr_valid_paths) && |
c1fd0abe | 1664 | !must_push_back_rq(m)) { |
2a842aca | 1665 | if (error == BLK_STS_IOERR) |
18a482f5 | 1666 | dm_report_EIO(m); |
7ed8578a CH |
1667 | /* complete with the original error */ |
1668 | r = DM_ENDIO_DONE; | |
1669 | } | |
b79f10ee | 1670 | } |
466891f9 | 1671 | |
1da177e4 | 1672 | if (pgpath) { |
b79f10ee CH |
1673 | struct path_selector *ps = &pgpath->pg->ps; |
1674 | ||
1da177e4 | 1675 | if (ps->type->end_io) |
087615bf GKB |
1676 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes, |
1677 | clone->io_start_time_ns); | |
1da177e4 | 1678 | } |
1da177e4 | 1679 | |
7ed8578a | 1680 | return r; |
1da177e4 LT |
1681 | } |
1682 | ||
4e4cbee9 | 1683 | static int multipath_end_io_bio(struct dm_target *ti, struct bio *clone, |
848b8aef | 1684 | blk_status_t *error) |
76e33fe4 | 1685 | { |
14ef1e48 CH |
1686 | struct multipath *m = ti->private; |
1687 | struct dm_mpath_io *mpio = get_mpio_from_bio(clone); | |
1688 | struct pgpath *pgpath = mpio->pgpath; | |
76e33fe4 | 1689 | unsigned long flags; |
1be56909 | 1690 | int r = DM_ENDIO_DONE; |
76e33fe4 | 1691 | |
a1275677 | 1692 | if (!*error || !blk_path_error(*error)) |
14ef1e48 | 1693 | goto done; |
76e33fe4 | 1694 | |
14ef1e48 CH |
1695 | if (pgpath) |
1696 | fail_path(pgpath); | |
76e33fe4 | 1697 | |
a271a89c MS |
1698 | if (!atomic_read(&m->nr_valid_paths)) { |
1699 | spin_lock_irqsave(&m->lock, flags); | |
1700 | if (!test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
1701 | if (__must_push_back(m)) { | |
1702 | r = DM_ENDIO_REQUEUE; | |
1703 | } else { | |
1704 | dm_report_EIO(m); | |
1705 | *error = BLK_STS_IOERR; | |
1706 | } | |
1707 | spin_unlock_irqrestore(&m->lock, flags); | |
1708 | goto done; | |
c1fd0abe | 1709 | } |
a271a89c | 1710 | spin_unlock_irqrestore(&m->lock, flags); |
18a482f5 | 1711 | } |
76e33fe4 | 1712 | |
f45f1186 | 1713 | multipath_queue_bio(m, clone); |
1be56909 | 1714 | r = DM_ENDIO_INCOMPLETE; |
14ef1e48 | 1715 | done: |
76e33fe4 | 1716 | if (pgpath) { |
14ef1e48 CH |
1717 | struct path_selector *ps = &pgpath->pg->ps; |
1718 | ||
76e33fe4 | 1719 | if (ps->type->end_io) |
087615bf | 1720 | ps->type->end_io(ps, &pgpath->path, mpio->nr_bytes, |
c06dfd12 GKB |
1721 | (mpio->start_time_ns ?: |
1722 | dm_start_time_ns_from_clone(clone))); | |
76e33fe4 MS |
1723 | } |
1724 | ||
1be56909 | 1725 | return r; |
76e33fe4 MS |
1726 | } |
1727 | ||
1da177e4 | 1728 | /* |
553ec94c MS |
1729 | * Suspend with flush can't complete until all the I/O is processed |
1730 | * so if the last path fails we must error any remaining I/O. | |
1731 | * - Note that if the freeze_bdev fails while suspending, the | |
1732 | * queue_if_no_path state is lost - userspace should reset it. | |
1733 | * Otherwise, during noflush suspend, queue_if_no_path will not change. | |
1da177e4 LT |
1734 | */ |
1735 | static void multipath_presuspend(struct dm_target *ti) | |
1736 | { | |
7943bd6d | 1737 | struct multipath *m = ti->private; |
1da177e4 | 1738 | |
553ec94c MS |
1739 | /* FIXME: bio-based shouldn't need to always disable queue_if_no_path */ |
1740 | if (m->queue_mode == DM_TYPE_BIO_BASED || !dm_noflush_suspending(m->ti)) | |
4c3f4838 | 1741 | queue_if_no_path(m, false, true, __func__); |
1da177e4 LT |
1742 | } |
1743 | ||
6df400ab KU |
1744 | static void multipath_postsuspend(struct dm_target *ti) |
1745 | { | |
6380f26f MA |
1746 | struct multipath *m = ti->private; |
1747 | ||
1748 | mutex_lock(&m->work_mutex); | |
2bded7bd | 1749 | flush_multipath_work(m); |
6380f26f | 1750 | mutex_unlock(&m->work_mutex); |
6df400ab KU |
1751 | } |
1752 | ||
436d4108 AK |
1753 | /* |
1754 | * Restore the queue_if_no_path setting. | |
1755 | */ | |
1da177e4 LT |
1756 | static void multipath_resume(struct dm_target *ti) |
1757 | { | |
7943bd6d | 1758 | struct multipath *m = ti->private; |
1814f2e3 | 1759 | unsigned long flags; |
1da177e4 | 1760 | |
1814f2e3 | 1761 | spin_lock_irqsave(&m->lock, flags); |
553ec94c MS |
1762 | if (test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)) { |
1763 | set_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags); | |
1764 | clear_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags); | |
1765 | } | |
4c3f4838 MS |
1766 | |
1767 | DMDEBUG("%s: %s finished; QIFNP = %d; SQIFNP = %d", | |
d4a512ed | 1768 | dm_table_device_name(m->ti->table), __func__, |
4c3f4838 MS |
1769 | test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags), |
1770 | test_bit(MPATHF_SAVED_QUEUE_IF_NO_PATH, &m->flags)); | |
1771 | ||
1814f2e3 | 1772 | spin_unlock_irqrestore(&m->lock, flags); |
1da177e4 LT |
1773 | } |
1774 | ||
1775 | /* | |
1776 | * Info output has the following format: | |
1777 | * num_multipath_feature_args [multipath_feature_args]* | |
1778 | * num_handler_status_args [handler_status_args]* | |
1779 | * num_groups init_group_number | |
1780 | * [A|D|E num_ps_status_args [ps_status_args]* | |
1781 | * num_paths num_selector_args | |
1782 | * [path_dev A|F fail_count [selector_args]* ]+ ]+ | |
1783 | * | |
1784 | * Table output has the following format (identical to the constructor string): | |
1785 | * num_feature_args [features_args]* | |
1786 | * num_handler_args hw_handler [hw_handler_args]* | |
1787 | * num_groups init_group_number | |
1788 | * [priority selector-name num_ps_args [ps_args]* | |
1789 | * num_paths num_selector_args [path_dev [selector_args]* ]+ ]+ | |
1790 | */ | |
fd7c092e MP |
1791 | static void multipath_status(struct dm_target *ti, status_type_t type, |
1792 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 | 1793 | { |
33ace4ca | 1794 | int sz = 0, pg_counter, pgpath_counter; |
1da177e4 | 1795 | unsigned long flags; |
7943bd6d | 1796 | struct multipath *m = ti->private; |
1da177e4 LT |
1797 | struct priority_group *pg; |
1798 | struct pgpath *p; | |
1799 | unsigned pg_num; | |
1800 | char state; | |
1801 | ||
1802 | spin_lock_irqsave(&m->lock, flags); | |
1803 | ||
1804 | /* Features */ | |
1805 | if (type == STATUSTYPE_INFO) | |
91e968aa MS |
1806 | DMEMIT("2 %u %u ", test_bit(MPATHF_QUEUE_IO, &m->flags), |
1807 | atomic_read(&m->pg_init_count)); | |
c9e45581 | 1808 | else { |
518257b1 | 1809 | DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) + |
4e2d19e4 | 1810 | (m->pg_init_retries > 0) * 2 + |
a58a935d | 1811 | (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + |
e83068a5 MS |
1812 | test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) + |
1813 | (m->queue_mode != DM_TYPE_REQUEST_BASED) * 2); | |
1814 | ||
518257b1 | 1815 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
c9e45581 DW |
1816 | DMEMIT("queue_if_no_path "); |
1817 | if (m->pg_init_retries) | |
1818 | DMEMIT("pg_init_retries %u ", m->pg_init_retries); | |
4e2d19e4 CS |
1819 | if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) |
1820 | DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); | |
518257b1 | 1821 | if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags)) |
a58a935d | 1822 | DMEMIT("retain_attached_hw_handler "); |
e83068a5 MS |
1823 | if (m->queue_mode != DM_TYPE_REQUEST_BASED) { |
1824 | switch(m->queue_mode) { | |
1825 | case DM_TYPE_BIO_BASED: | |
1826 | DMEMIT("queue_mode bio "); | |
1827 | break; | |
7e0d574f BVA |
1828 | default: |
1829 | WARN_ON_ONCE(true); | |
1830 | break; | |
e83068a5 MS |
1831 | } |
1832 | } | |
c9e45581 | 1833 | } |
1da177e4 | 1834 | |
cfae5c9b | 1835 | if (!m->hw_handler_name || type == STATUSTYPE_INFO) |
1da177e4 LT |
1836 | DMEMIT("0 "); |
1837 | else | |
cfae5c9b | 1838 | DMEMIT("1 %s ", m->hw_handler_name); |
1da177e4 LT |
1839 | |
1840 | DMEMIT("%u ", m->nr_priority_groups); | |
1841 | ||
1842 | if (m->next_pg) | |
1843 | pg_num = m->next_pg->pg_num; | |
1844 | else if (m->current_pg) | |
1845 | pg_num = m->current_pg->pg_num; | |
1846 | else | |
a490a07a | 1847 | pg_num = (m->nr_priority_groups ? 1 : 0); |
1da177e4 LT |
1848 | |
1849 | DMEMIT("%u ", pg_num); | |
1850 | ||
1851 | switch (type) { | |
1852 | case STATUSTYPE_INFO: | |
1853 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1854 | if (pg->bypassed) | |
1855 | state = 'D'; /* Disabled */ | |
1856 | else if (pg == m->current_pg) | |
1857 | state = 'A'; /* Currently Active */ | |
1858 | else | |
1859 | state = 'E'; /* Enabled */ | |
1860 | ||
1861 | DMEMIT("%c ", state); | |
1862 | ||
1863 | if (pg->ps.type->status) | |
1864 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1865 | result + sz, | |
1866 | maxlen - sz); | |
1867 | else | |
1868 | DMEMIT("0 "); | |
1869 | ||
1870 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1871 | pg->ps.type->info_args); | |
1872 | ||
1873 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1874 | DMEMIT("%s %s %u ", p->path.dev->name, | |
6680073d | 1875 | p->is_active ? "A" : "F", |
1da177e4 LT |
1876 | p->fail_count); |
1877 | if (pg->ps.type->status) | |
1878 | sz += pg->ps.type->status(&pg->ps, | |
1879 | &p->path, type, result + sz, | |
1880 | maxlen - sz); | |
1881 | } | |
1882 | } | |
1883 | break; | |
1884 | ||
1885 | case STATUSTYPE_TABLE: | |
1886 | list_for_each_entry(pg, &m->priority_groups, list) { | |
1887 | DMEMIT("%s ", pg->ps.type->name); | |
1888 | ||
1889 | if (pg->ps.type->status) | |
1890 | sz += pg->ps.type->status(&pg->ps, NULL, type, | |
1891 | result + sz, | |
1892 | maxlen - sz); | |
1893 | else | |
1894 | DMEMIT("0 "); | |
1895 | ||
1896 | DMEMIT("%u %u ", pg->nr_pgpaths, | |
1897 | pg->ps.type->table_args); | |
1898 | ||
1899 | list_for_each_entry(p, &pg->pgpaths, list) { | |
1900 | DMEMIT("%s ", p->path.dev->name); | |
1901 | if (pg->ps.type->status) | |
1902 | sz += pg->ps.type->status(&pg->ps, | |
1903 | &p->path, type, result + sz, | |
1904 | maxlen - sz); | |
1905 | } | |
1906 | } | |
1907 | break; | |
8ec45662 TS |
1908 | |
1909 | case STATUSTYPE_IMA: | |
33ace4ca TS |
1910 | sz = 0; /*reset the result pointer*/ |
1911 | ||
8ec45662 | 1912 | DMEMIT_TARGET_NAME_VERSION(ti->type); |
33ace4ca TS |
1913 | DMEMIT(",nr_priority_groups=%u", m->nr_priority_groups); |
1914 | ||
1915 | pg_counter = 0; | |
8ec45662 TS |
1916 | list_for_each_entry(pg, &m->priority_groups, list) { |
1917 | if (pg->bypassed) | |
1918 | state = 'D'; /* Disabled */ | |
1919 | else if (pg == m->current_pg) | |
1920 | state = 'A'; /* Currently Active */ | |
1921 | else | |
1922 | state = 'E'; /* Enabled */ | |
33ace4ca TS |
1923 | DMEMIT(",pg_state_%d=%c", pg_counter, state); |
1924 | DMEMIT(",nr_pgpaths_%d=%u", pg_counter, pg->nr_pgpaths); | |
1925 | DMEMIT(",path_selector_name_%d=%s", pg_counter, pg->ps.type->name); | |
8ec45662 | 1926 | |
33ace4ca | 1927 | pgpath_counter = 0; |
8ec45662 | 1928 | list_for_each_entry(p, &pg->pgpaths, list) { |
33ace4ca TS |
1929 | DMEMIT(",path_name_%d_%d=%s,is_active_%d_%d=%c,fail_count_%d_%d=%u", |
1930 | pg_counter, pgpath_counter, p->path.dev->name, | |
1931 | pg_counter, pgpath_counter, p->is_active ? 'A' : 'F', | |
1932 | pg_counter, pgpath_counter, p->fail_count); | |
8ec45662 | 1933 | if (pg->ps.type->status) { |
33ace4ca TS |
1934 | DMEMIT(",path_selector_status_%d_%d=", |
1935 | pg_counter, pgpath_counter); | |
8ec45662 TS |
1936 | sz += pg->ps.type->status(&pg->ps, &p->path, |
1937 | type, result + sz, | |
1938 | maxlen - sz); | |
1939 | } | |
33ace4ca | 1940 | pgpath_counter++; |
8ec45662 | 1941 | } |
33ace4ca | 1942 | pg_counter++; |
8ec45662 TS |
1943 | } |
1944 | DMEMIT(";"); | |
1945 | break; | |
1da177e4 LT |
1946 | } |
1947 | ||
1948 | spin_unlock_irqrestore(&m->lock, flags); | |
1da177e4 LT |
1949 | } |
1950 | ||
1eb5fa84 MS |
1951 | static int multipath_message(struct dm_target *ti, unsigned argc, char **argv, |
1952 | char *result, unsigned maxlen) | |
1da177e4 | 1953 | { |
6380f26f | 1954 | int r = -EINVAL; |
1da177e4 | 1955 | struct dm_dev *dev; |
7943bd6d | 1956 | struct multipath *m = ti->private; |
1da177e4 | 1957 | action_fn action; |
be240ff5 | 1958 | unsigned long flags; |
1da177e4 | 1959 | |
6380f26f MA |
1960 | mutex_lock(&m->work_mutex); |
1961 | ||
c2f3d24b KU |
1962 | if (dm_suspended(ti)) { |
1963 | r = -EBUSY; | |
1964 | goto out; | |
1965 | } | |
1966 | ||
1da177e4 | 1967 | if (argc == 1) { |
498f0103 | 1968 | if (!strcasecmp(argv[0], "queue_if_no_path")) { |
4c3f4838 | 1969 | r = queue_if_no_path(m, true, false, __func__); |
be240ff5 AP |
1970 | spin_lock_irqsave(&m->lock, flags); |
1971 | enable_nopath_timeout(m); | |
1972 | spin_unlock_irqrestore(&m->lock, flags); | |
6380f26f | 1973 | goto out; |
498f0103 | 1974 | } else if (!strcasecmp(argv[0], "fail_if_no_path")) { |
4c3f4838 | 1975 | r = queue_if_no_path(m, false, false, __func__); |
be240ff5 | 1976 | disable_nopath_timeout(m); |
6380f26f MA |
1977 | goto out; |
1978 | } | |
1da177e4 LT |
1979 | } |
1980 | ||
6380f26f | 1981 | if (argc != 2) { |
a356e426 | 1982 | DMWARN("Invalid multipath message arguments. Expected 2 arguments, got %d.", argc); |
6380f26f MA |
1983 | goto out; |
1984 | } | |
1da177e4 | 1985 | |
498f0103 | 1986 | if (!strcasecmp(argv[0], "disable_group")) { |
be7d31cc | 1987 | r = bypass_pg_num(m, argv[1], true); |
6380f26f | 1988 | goto out; |
498f0103 | 1989 | } else if (!strcasecmp(argv[0], "enable_group")) { |
be7d31cc | 1990 | r = bypass_pg_num(m, argv[1], false); |
6380f26f | 1991 | goto out; |
498f0103 | 1992 | } else if (!strcasecmp(argv[0], "switch_group")) { |
6380f26f MA |
1993 | r = switch_pg_num(m, argv[1]); |
1994 | goto out; | |
498f0103 | 1995 | } else if (!strcasecmp(argv[0], "reinstate_path")) |
1da177e4 | 1996 | action = reinstate_path; |
498f0103 | 1997 | else if (!strcasecmp(argv[0], "fail_path")) |
1da177e4 | 1998 | action = fail_path; |
6380f26f | 1999 | else { |
a356e426 | 2000 | DMWARN("Unrecognised multipath message received: %s", argv[0]); |
6380f26f MA |
2001 | goto out; |
2002 | } | |
1da177e4 | 2003 | |
8215d6ec | 2004 | r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev); |
1da177e4 | 2005 | if (r) { |
72d94861 | 2006 | DMWARN("message: error getting device %s", |
1da177e4 | 2007 | argv[1]); |
6380f26f | 2008 | goto out; |
1da177e4 LT |
2009 | } |
2010 | ||
2011 | r = action_dev(m, dev, action); | |
2012 | ||
2013 | dm_put_device(ti, dev); | |
2014 | ||
6380f26f MA |
2015 | out: |
2016 | mutex_unlock(&m->work_mutex); | |
1da177e4 | 2017 | return r; |
1da177e4 LT |
2018 | } |
2019 | ||
e56f81e0 | 2020 | static int multipath_prepare_ioctl(struct dm_target *ti, |
5bd5e8d8 | 2021 | struct block_device **bdev) |
9af4aa30 | 2022 | { |
35991652 | 2023 | struct multipath *m = ti->private; |
564dbb13 | 2024 | struct pgpath *pgpath; |
69cea0d4 | 2025 | unsigned long flags; |
35991652 MP |
2026 | int r; |
2027 | ||
564dbb13 | 2028 | pgpath = READ_ONCE(m->current_pgpath); |
374117ad | 2029 | if (!pgpath || !mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) |
564dbb13 | 2030 | pgpath = choose_pgpath(m, 0); |
9af4aa30 | 2031 | |
564dbb13 | 2032 | if (pgpath) { |
374117ad | 2033 | if (!mpath_double_check_test_bit(MPATHF_QUEUE_IO, m)) { |
564dbb13 | 2034 | *bdev = pgpath->path.dev->bdev; |
43e43c9e JN |
2035 | r = 0; |
2036 | } else { | |
2037 | /* pg_init has not started or completed */ | |
2038 | r = -ENOTCONN; | |
2039 | } | |
2040 | } else { | |
2041 | /* No path is available */ | |
a271a89c MS |
2042 | r = -EIO; |
2043 | spin_lock_irqsave(&m->lock, flags); | |
518257b1 | 2044 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) |
43e43c9e | 2045 | r = -ENOTCONN; |
a271a89c | 2046 | spin_unlock_irqrestore(&m->lock, flags); |
e90dae1f | 2047 | } |
9af4aa30 | 2048 | |
5bbbfdf6 | 2049 | if (r == -ENOTCONN) { |
506458ef | 2050 | if (!READ_ONCE(m->current_pg)) { |
3e9f1be1 | 2051 | /* Path status changed, redo selection */ |
2da1610a | 2052 | (void) choose_pgpath(m, 0); |
3e9f1be1 | 2053 | } |
69cea0d4 | 2054 | spin_lock_irqsave(&m->lock, flags); |
518257b1 | 2055 | if (test_bit(MPATHF_PG_INIT_REQUIRED, &m->flags)) |
69cea0d4 MS |
2056 | (void) __pg_init_all_paths(m); |
2057 | spin_unlock_irqrestore(&m->lock, flags); | |
63d832c3 | 2058 | dm_table_run_md_queue_async(m->ti->table); |
7e48c768 | 2059 | process_queued_io_list(m); |
3e9f1be1 | 2060 | } |
35991652 | 2061 | |
e56f81e0 CH |
2062 | /* |
2063 | * Only pass ioctls through if the device sizes match exactly. | |
2064 | */ | |
6dcbb52c | 2065 | if (!r && ti->len != bdev_nr_sectors((*bdev))) |
e56f81e0 CH |
2066 | return 1; |
2067 | return r; | |
9af4aa30 MB |
2068 | } |
2069 | ||
af4874e0 MS |
2070 | static int multipath_iterate_devices(struct dm_target *ti, |
2071 | iterate_devices_callout_fn fn, void *data) | |
2072 | { | |
2073 | struct multipath *m = ti->private; | |
2074 | struct priority_group *pg; | |
2075 | struct pgpath *p; | |
2076 | int ret = 0; | |
2077 | ||
2078 | list_for_each_entry(pg, &m->priority_groups, list) { | |
2079 | list_for_each_entry(p, &pg->pgpaths, list) { | |
5dea271b | 2080 | ret = fn(ti, p->path.dev, ti->begin, ti->len, data); |
af4874e0 MS |
2081 | if (ret) |
2082 | goto out; | |
2083 | } | |
2084 | } | |
2085 | ||
2086 | out: | |
2087 | return ret; | |
2088 | } | |
2089 | ||
9f54cec5 | 2090 | static int pgpath_busy(struct pgpath *pgpath) |
f40c67f0 KU |
2091 | { |
2092 | struct request_queue *q = bdev_get_queue(pgpath->path.dev->bdev); | |
2093 | ||
52b09914 | 2094 | return blk_lld_busy(q); |
f40c67f0 KU |
2095 | } |
2096 | ||
2097 | /* | |
2098 | * We return "busy", only when we can map I/Os but underlying devices | |
2099 | * are busy (so even if we map I/Os now, the I/Os will wait on | |
2100 | * the underlying queue). | |
2101 | * In other words, if we want to kill I/Os or queue them inside us | |
2102 | * due to map unavailability, we don't return "busy". Otherwise, | |
2103 | * dm core won't give us the I/Os and we can't do what we want. | |
2104 | */ | |
2105 | static int multipath_busy(struct dm_target *ti) | |
2106 | { | |
be7d31cc | 2107 | bool busy = false, has_active = false; |
f40c67f0 | 2108 | struct multipath *m = ti->private; |
2da1610a | 2109 | struct priority_group *pg, *next_pg; |
f40c67f0 | 2110 | struct pgpath *pgpath; |
f40c67f0 | 2111 | |
b88efd43 MS |
2112 | /* pg_init in progress */ |
2113 | if (atomic_read(&m->pg_init_in_progress)) | |
2da1610a MS |
2114 | return true; |
2115 | ||
b88efd43 | 2116 | /* no paths available, for blk-mq: rely on IO mapping to delay requeue */ |
a271a89c MS |
2117 | if (!atomic_read(&m->nr_valid_paths)) { |
2118 | unsigned long flags; | |
2119 | spin_lock_irqsave(&m->lock, flags); | |
2120 | if (test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags)) { | |
2121 | spin_unlock_irqrestore(&m->lock, flags); | |
2122 | return (m->queue_mode != DM_TYPE_REQUEST_BASED); | |
2123 | } | |
2124 | spin_unlock_irqrestore(&m->lock, flags); | |
2125 | } | |
b88efd43 | 2126 | |
f40c67f0 | 2127 | /* Guess which priority_group will be used at next mapping time */ |
506458ef WD |
2128 | pg = READ_ONCE(m->current_pg); |
2129 | next_pg = READ_ONCE(m->next_pg); | |
2130 | if (unlikely(!READ_ONCE(m->current_pgpath) && next_pg)) | |
2da1610a MS |
2131 | pg = next_pg; |
2132 | ||
2133 | if (!pg) { | |
f40c67f0 KU |
2134 | /* |
2135 | * We don't know which pg will be used at next mapping time. | |
2da1610a | 2136 | * We don't call choose_pgpath() here to avoid to trigger |
f40c67f0 KU |
2137 | * pg_init just by busy checking. |
2138 | * So we don't know whether underlying devices we will be using | |
2139 | * at next mapping time are busy or not. Just try mapping. | |
2140 | */ | |
2da1610a MS |
2141 | return busy; |
2142 | } | |
f40c67f0 KU |
2143 | |
2144 | /* | |
2145 | * If there is one non-busy active path at least, the path selector | |
2146 | * will be able to select it. So we consider such a pg as not busy. | |
2147 | */ | |
be7d31cc | 2148 | busy = true; |
2da1610a | 2149 | list_for_each_entry(pgpath, &pg->pgpaths, list) { |
f40c67f0 | 2150 | if (pgpath->is_active) { |
be7d31cc | 2151 | has_active = true; |
9f54cec5 | 2152 | if (!pgpath_busy(pgpath)) { |
be7d31cc | 2153 | busy = false; |
f40c67f0 KU |
2154 | break; |
2155 | } | |
2156 | } | |
2da1610a | 2157 | } |
f40c67f0 | 2158 | |
2da1610a | 2159 | if (!has_active) { |
f40c67f0 KU |
2160 | /* |
2161 | * No active path in this pg, so this pg won't be used and | |
2162 | * the current_pg will be changed at next mapping time. | |
2163 | * We need to try mapping to determine it. | |
2164 | */ | |
be7d31cc | 2165 | busy = false; |
2da1610a | 2166 | } |
f40c67f0 KU |
2167 | |
2168 | return busy; | |
2169 | } | |
2170 | ||
1da177e4 LT |
2171 | /*----------------------------------------------------------------- |
2172 | * Module setup | |
2173 | *---------------------------------------------------------------*/ | |
2174 | static struct target_type multipath_target = { | |
2175 | .name = "multipath", | |
636be424 | 2176 | .version = {1, 14, 0}, |
8c5c1473 SM |
2177 | .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE | |
2178 | DM_TARGET_PASSES_INTEGRITY, | |
1da177e4 LT |
2179 | .module = THIS_MODULE, |
2180 | .ctr = multipath_ctr, | |
2181 | .dtr = multipath_dtr, | |
e5863d9a MS |
2182 | .clone_and_map_rq = multipath_clone_and_map, |
2183 | .release_clone_rq = multipath_release_clone, | |
f40c67f0 | 2184 | .rq_end_io = multipath_end_io, |
76e33fe4 MS |
2185 | .map = multipath_map_bio, |
2186 | .end_io = multipath_end_io_bio, | |
2187 | .presuspend = multipath_presuspend, | |
2188 | .postsuspend = multipath_postsuspend, | |
2189 | .resume = multipath_resume, | |
2190 | .status = multipath_status, | |
2191 | .message = multipath_message, | |
2192 | .prepare_ioctl = multipath_prepare_ioctl, | |
2193 | .iterate_devices = multipath_iterate_devices, | |
2194 | .busy = multipath_busy, | |
2195 | }; | |
2196 | ||
1da177e4 LT |
2197 | static int __init dm_multipath_init(void) |
2198 | { | |
2199 | int r; | |
2200 | ||
4d4d66ab | 2201 | kmultipathd = alloc_workqueue("kmpathd", WQ_MEM_RECLAIM, 0); |
c557308e | 2202 | if (!kmultipathd) { |
0cd33124 | 2203 | DMERR("failed to create workqueue kmpathd"); |
ff658e9c JT |
2204 | r = -ENOMEM; |
2205 | goto bad_alloc_kmultipathd; | |
c557308e AK |
2206 | } |
2207 | ||
bab7cfc7 CS |
2208 | /* |
2209 | * A separate workqueue is used to handle the device handlers | |
2210 | * to avoid overloading existing workqueue. Overloading the | |
2211 | * old workqueue would also create a bottleneck in the | |
2212 | * path of the storage hardware device activation. | |
2213 | */ | |
4d4d66ab TH |
2214 | kmpath_handlerd = alloc_ordered_workqueue("kmpath_handlerd", |
2215 | WQ_MEM_RECLAIM); | |
bab7cfc7 CS |
2216 | if (!kmpath_handlerd) { |
2217 | DMERR("failed to create workqueue kmpath_handlerd"); | |
ff658e9c JT |
2218 | r = -ENOMEM; |
2219 | goto bad_alloc_kmpath_handlerd; | |
bab7cfc7 CS |
2220 | } |
2221 | ||
7e6358d2 | 2222 | r = dm_register_target(&multipath_target); |
2223 | if (r < 0) { | |
2224 | DMERR("request-based register failed %d", r); | |
2225 | r = -EINVAL; | |
2226 | goto bad_register_target; | |
2227 | } | |
2228 | ||
ff658e9c JT |
2229 | return 0; |
2230 | ||
7e6358d2 | 2231 | bad_register_target: |
2232 | destroy_workqueue(kmpath_handlerd); | |
ff658e9c JT |
2233 | bad_alloc_kmpath_handlerd: |
2234 | destroy_workqueue(kmultipathd); | |
2235 | bad_alloc_kmultipathd: | |
1da177e4 LT |
2236 | return r; |
2237 | } | |
2238 | ||
2239 | static void __exit dm_multipath_exit(void) | |
2240 | { | |
bab7cfc7 | 2241 | destroy_workqueue(kmpath_handlerd); |
c557308e AK |
2242 | destroy_workqueue(kmultipathd); |
2243 | ||
10d3bd09 | 2244 | dm_unregister_target(&multipath_target); |
1da177e4 LT |
2245 | } |
2246 | ||
1da177e4 LT |
2247 | module_init(dm_multipath_init); |
2248 | module_exit(dm_multipath_exit); | |
2249 | ||
be240ff5 AP |
2250 | module_param_named(queue_if_no_path_timeout_secs, |
2251 | queue_if_no_path_timeout_secs, ulong, S_IRUGO | S_IWUSR); | |
2252 | MODULE_PARM_DESC(queue_if_no_path_timeout_secs, "No available paths queue IO timeout in seconds"); | |
2253 | ||
1da177e4 LT |
2254 | MODULE_DESCRIPTION(DM_NAME " multipath target"); |
2255 | MODULE_AUTHOR("Sistina Software <dm-devel@redhat.com>"); | |
2256 | MODULE_LICENSE("GPL"); |