Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software Limited. | |
1f965b19 | 3 | * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
4 | * |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
06386bbf | 8 | #include "dm-bio-record.h" |
1da177e4 | 9 | |
1da177e4 LT |
10 | #include <linux/init.h> |
11 | #include <linux/mempool.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/pagemap.h> | |
14 | #include <linux/slab.h> | |
1da177e4 | 15 | #include <linux/workqueue.h> |
1f965b19 | 16 | #include <linux/device-mapper.h> |
a765e20e AK |
17 | #include <linux/dm-io.h> |
18 | #include <linux/dm-dirty-log.h> | |
19 | #include <linux/dm-kcopyd.h> | |
1f965b19 | 20 | #include <linux/dm-region-hash.h> |
1da177e4 | 21 | |
72d94861 | 22 | #define DM_MSG_PREFIX "raid1" |
1f965b19 HM |
23 | |
24 | #define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */ | |
88be163a | 25 | #define DM_IO_PAGES 64 |
1f965b19 | 26 | #define DM_KCOPYD_PAGES 64 |
72d94861 | 27 | |
a8e6afa2 | 28 | #define DM_RAID1_HANDLE_ERRORS 0x01 |
f44db678 | 29 | #define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS) |
a8e6afa2 | 30 | |
33184048 | 31 | static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped); |
1da177e4 | 32 | |
e4c8b3ba NB |
33 | /*----------------------------------------------------------------- |
34 | * Mirror set structures. | |
35 | *---------------------------------------------------------------*/ | |
72f4b314 JB |
36 | enum dm_raid1_error { |
37 | DM_RAID1_WRITE_ERROR, | |
38 | DM_RAID1_SYNC_ERROR, | |
39 | DM_RAID1_READ_ERROR | |
40 | }; | |
41 | ||
e4c8b3ba | 42 | struct mirror { |
aa5617c5 | 43 | struct mirror_set *ms; |
e4c8b3ba | 44 | atomic_t error_count; |
39ed7adb | 45 | unsigned long error_type; |
e4c8b3ba NB |
46 | struct dm_dev *dev; |
47 | sector_t offset; | |
48 | }; | |
49 | ||
50 | struct mirror_set { | |
51 | struct dm_target *ti; | |
52 | struct list_head list; | |
1f965b19 | 53 | |
a8e6afa2 | 54 | uint64_t features; |
e4c8b3ba | 55 | |
72f4b314 | 56 | spinlock_t lock; /* protects the lists */ |
e4c8b3ba NB |
57 | struct bio_list reads; |
58 | struct bio_list writes; | |
72f4b314 | 59 | struct bio_list failures; |
e4c8b3ba | 60 | |
1f965b19 HM |
61 | struct dm_region_hash *rh; |
62 | struct dm_kcopyd_client *kcopyd_client; | |
88be163a | 63 | struct dm_io_client *io_client; |
06386bbf | 64 | mempool_t *read_record_pool; |
88be163a | 65 | |
e4c8b3ba NB |
66 | /* recovery */ |
67 | region_t nr_regions; | |
68 | int in_sync; | |
fc1ff958 | 69 | int log_failure; |
b80aa7a0 | 70 | atomic_t suspend; |
e4c8b3ba | 71 | |
72f4b314 | 72 | atomic_t default_mirror; /* Default mirror */ |
e4c8b3ba | 73 | |
6ad36fe2 HS |
74 | struct workqueue_struct *kmirrord_wq; |
75 | struct work_struct kmirrord_work; | |
a2aebe03 MP |
76 | struct timer_list timer; |
77 | unsigned long timer_pending; | |
78 | ||
72f4b314 | 79 | struct work_struct trigger_event; |
6ad36fe2 | 80 | |
1f965b19 | 81 | unsigned nr_mirrors; |
e4c8b3ba NB |
82 | struct mirror mirror[0]; |
83 | }; | |
84 | ||
1f965b19 | 85 | static void wakeup_mirrord(void *context) |
1da177e4 | 86 | { |
1f965b19 | 87 | struct mirror_set *ms = context; |
1da177e4 | 88 | |
6ad36fe2 HS |
89 | queue_work(ms->kmirrord_wq, &ms->kmirrord_work); |
90 | } | |
91 | ||
a2aebe03 MP |
92 | static void delayed_wake_fn(unsigned long data) |
93 | { | |
94 | struct mirror_set *ms = (struct mirror_set *) data; | |
95 | ||
96 | clear_bit(0, &ms->timer_pending); | |
1f965b19 | 97 | wakeup_mirrord(ms); |
a2aebe03 MP |
98 | } |
99 | ||
100 | static void delayed_wake(struct mirror_set *ms) | |
101 | { | |
102 | if (test_and_set_bit(0, &ms->timer_pending)) | |
103 | return; | |
104 | ||
105 | ms->timer.expires = jiffies + HZ / 5; | |
106 | ms->timer.data = (unsigned long) ms; | |
107 | ms->timer.function = delayed_wake_fn; | |
108 | add_timer(&ms->timer); | |
109 | } | |
110 | ||
1f965b19 | 111 | static void wakeup_all_recovery_waiters(void *context) |
1da177e4 | 112 | { |
1f965b19 | 113 | wake_up_all(&_kmirrord_recovery_stopped); |
1da177e4 LT |
114 | } |
115 | ||
1f965b19 | 116 | static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw) |
1da177e4 LT |
117 | { |
118 | unsigned long flags; | |
1da177e4 | 119 | int should_wake = 0; |
1f965b19 | 120 | struct bio_list *bl; |
1da177e4 | 121 | |
1f965b19 HM |
122 | bl = (rw == WRITE) ? &ms->writes : &ms->reads; |
123 | spin_lock_irqsave(&ms->lock, flags); | |
124 | should_wake = !(bl->head); | |
125 | bio_list_add(bl, bio); | |
126 | spin_unlock_irqrestore(&ms->lock, flags); | |
1da177e4 LT |
127 | |
128 | if (should_wake) | |
1f965b19 | 129 | wakeup_mirrord(ms); |
1da177e4 LT |
130 | } |
131 | ||
1f965b19 | 132 | static void dispatch_bios(void *context, struct bio_list *bio_list) |
1da177e4 | 133 | { |
1f965b19 HM |
134 | struct mirror_set *ms = context; |
135 | struct bio *bio; | |
1da177e4 | 136 | |
1f965b19 HM |
137 | while ((bio = bio_list_pop(bio_list))) |
138 | queue_bio(ms, bio, WRITE); | |
1da177e4 LT |
139 | } |
140 | ||
06386bbf JB |
141 | #define MIN_READ_RECORDS 20 |
142 | struct dm_raid1_read_record { | |
143 | struct mirror *m; | |
144 | struct dm_bio_details details; | |
145 | }; | |
146 | ||
95f8fac8 MP |
147 | static struct kmem_cache *_dm_raid1_read_record_cache; |
148 | ||
1da177e4 LT |
149 | /* |
150 | * Every mirror should look like this one. | |
151 | */ | |
152 | #define DEFAULT_MIRROR 0 | |
153 | ||
154 | /* | |
06386bbf JB |
155 | * This is yucky. We squirrel the mirror struct away inside |
156 | * bi_next for read/write buffers. This is safe since the bh | |
1da177e4 LT |
157 | * doesn't get submitted to the lower levels of block layer. |
158 | */ | |
06386bbf | 159 | static struct mirror *bio_get_m(struct bio *bio) |
1da177e4 | 160 | { |
06386bbf | 161 | return (struct mirror *) bio->bi_next; |
1da177e4 LT |
162 | } |
163 | ||
06386bbf | 164 | static void bio_set_m(struct bio *bio, struct mirror *m) |
1da177e4 | 165 | { |
06386bbf | 166 | bio->bi_next = (struct bio *) m; |
1da177e4 LT |
167 | } |
168 | ||
72f4b314 JB |
169 | static struct mirror *get_default_mirror(struct mirror_set *ms) |
170 | { | |
171 | return &ms->mirror[atomic_read(&ms->default_mirror)]; | |
172 | } | |
173 | ||
174 | static void set_default_mirror(struct mirror *m) | |
175 | { | |
176 | struct mirror_set *ms = m->ms; | |
177 | struct mirror *m0 = &(ms->mirror[0]); | |
178 | ||
179 | atomic_set(&ms->default_mirror, m - m0); | |
180 | } | |
181 | ||
182 | /* fail_mirror | |
183 | * @m: mirror device to fail | |
184 | * @error_type: one of the enum's, DM_RAID1_*_ERROR | |
185 | * | |
186 | * If errors are being handled, record the type of | |
187 | * error encountered for this device. If this type | |
188 | * of error has already been recorded, we can return; | |
189 | * otherwise, we must signal userspace by triggering | |
190 | * an event. Additionally, if the device is the | |
191 | * primary device, we must choose a new primary, but | |
192 | * only if the mirror is in-sync. | |
193 | * | |
194 | * This function must not block. | |
195 | */ | |
196 | static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type) | |
197 | { | |
198 | struct mirror_set *ms = m->ms; | |
199 | struct mirror *new; | |
200 | ||
72f4b314 JB |
201 | /* |
202 | * error_count is used for nothing more than a | |
203 | * simple way to tell if a device has encountered | |
204 | * errors. | |
205 | */ | |
206 | atomic_inc(&m->error_count); | |
207 | ||
208 | if (test_and_set_bit(error_type, &m->error_type)) | |
209 | return; | |
210 | ||
d460c65a JB |
211 | if (!errors_handled(ms)) |
212 | return; | |
213 | ||
72f4b314 JB |
214 | if (m != get_default_mirror(ms)) |
215 | goto out; | |
216 | ||
217 | if (!ms->in_sync) { | |
218 | /* | |
219 | * Better to issue requests to same failing device | |
220 | * than to risk returning corrupt data. | |
221 | */ | |
222 | DMERR("Primary mirror (%s) failed while out-of-sync: " | |
223 | "Reads may fail.", m->dev->name); | |
224 | goto out; | |
225 | } | |
226 | ||
227 | for (new = ms->mirror; new < ms->mirror + ms->nr_mirrors; new++) | |
228 | if (!atomic_read(&new->error_count)) { | |
229 | set_default_mirror(new); | |
230 | break; | |
231 | } | |
232 | ||
233 | if (unlikely(new == ms->mirror + ms->nr_mirrors)) | |
234 | DMWARN("All sides of mirror have failed."); | |
235 | ||
236 | out: | |
237 | schedule_work(&ms->trigger_event); | |
238 | } | |
239 | ||
1da177e4 LT |
240 | /*----------------------------------------------------------------- |
241 | * Recovery. | |
242 | * | |
243 | * When a mirror is first activated we may find that some regions | |
244 | * are in the no-sync state. We have to recover these by | |
245 | * recopying from the default mirror to all the others. | |
246 | *---------------------------------------------------------------*/ | |
4cdc1d1f | 247 | static void recovery_complete(int read_err, unsigned long write_err, |
1da177e4 LT |
248 | void *context) |
249 | { | |
1f965b19 HM |
250 | struct dm_region *reg = context; |
251 | struct mirror_set *ms = dm_rh_region_context(reg); | |
8f0205b7 | 252 | int m, bit = 0; |
1da177e4 | 253 | |
8f0205b7 | 254 | if (read_err) { |
f44db678 JB |
255 | /* Read error means the failure of default mirror. */ |
256 | DMERR_LIMIT("Unable to read primary mirror during recovery"); | |
8f0205b7 JB |
257 | fail_mirror(get_default_mirror(ms), DM_RAID1_SYNC_ERROR); |
258 | } | |
f44db678 | 259 | |
8f0205b7 | 260 | if (write_err) { |
4cdc1d1f | 261 | DMERR_LIMIT("Write error during recovery (error = 0x%lx)", |
f44db678 | 262 | write_err); |
8f0205b7 JB |
263 | /* |
264 | * Bits correspond to devices (excluding default mirror). | |
265 | * The default mirror cannot change during recovery. | |
266 | */ | |
267 | for (m = 0; m < ms->nr_mirrors; m++) { | |
268 | if (&ms->mirror[m] == get_default_mirror(ms)) | |
269 | continue; | |
270 | if (test_bit(bit, &write_err)) | |
271 | fail_mirror(ms->mirror + m, | |
272 | DM_RAID1_SYNC_ERROR); | |
273 | bit++; | |
274 | } | |
275 | } | |
f44db678 | 276 | |
1f965b19 | 277 | dm_rh_recovery_end(reg, !(read_err || write_err)); |
1da177e4 LT |
278 | } |
279 | ||
1f965b19 | 280 | static int recover(struct mirror_set *ms, struct dm_region *reg) |
1da177e4 LT |
281 | { |
282 | int r; | |
1f965b19 | 283 | unsigned i; |
eb69aca5 | 284 | struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest; |
1da177e4 LT |
285 | struct mirror *m; |
286 | unsigned long flags = 0; | |
1f965b19 HM |
287 | region_t key = dm_rh_get_region_key(reg); |
288 | sector_t region_size = dm_rh_get_region_size(ms->rh); | |
1da177e4 LT |
289 | |
290 | /* fill in the source */ | |
72f4b314 | 291 | m = get_default_mirror(ms); |
1da177e4 | 292 | from.bdev = m->dev->bdev; |
1f965b19 HM |
293 | from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key); |
294 | if (key == (ms->nr_regions - 1)) { | |
1da177e4 LT |
295 | /* |
296 | * The final region may be smaller than | |
297 | * region_size. | |
298 | */ | |
1f965b19 | 299 | from.count = ms->ti->len & (region_size - 1); |
1da177e4 | 300 | if (!from.count) |
1f965b19 | 301 | from.count = region_size; |
1da177e4 | 302 | } else |
1f965b19 | 303 | from.count = region_size; |
1da177e4 LT |
304 | |
305 | /* fill in the destinations */ | |
306 | for (i = 0, dest = to; i < ms->nr_mirrors; i++) { | |
72f4b314 | 307 | if (&ms->mirror[i] == get_default_mirror(ms)) |
1da177e4 LT |
308 | continue; |
309 | ||
310 | m = ms->mirror + i; | |
311 | dest->bdev = m->dev->bdev; | |
1f965b19 | 312 | dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key); |
1da177e4 LT |
313 | dest->count = from.count; |
314 | dest++; | |
315 | } | |
316 | ||
317 | /* hand to kcopyd */ | |
f7c83e2e JB |
318 | if (!errors_handled(ms)) |
319 | set_bit(DM_KCOPYD_IGNORE_ERROR, &flags); | |
320 | ||
eb69aca5 HM |
321 | r = dm_kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to, |
322 | flags, recovery_complete, reg); | |
1da177e4 LT |
323 | |
324 | return r; | |
325 | } | |
326 | ||
327 | static void do_recovery(struct mirror_set *ms) | |
328 | { | |
1f965b19 HM |
329 | struct dm_region *reg; |
330 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); | |
1da177e4 | 331 | int r; |
1da177e4 LT |
332 | |
333 | /* | |
334 | * Start quiescing some regions. | |
335 | */ | |
1f965b19 | 336 | dm_rh_recovery_prepare(ms->rh); |
1da177e4 LT |
337 | |
338 | /* | |
339 | * Copy any already quiesced regions. | |
340 | */ | |
1f965b19 | 341 | while ((reg = dm_rh_recovery_start(ms->rh))) { |
1da177e4 LT |
342 | r = recover(ms, reg); |
343 | if (r) | |
1f965b19 | 344 | dm_rh_recovery_end(reg, 0); |
1da177e4 LT |
345 | } |
346 | ||
347 | /* | |
348 | * Update the in sync flag. | |
349 | */ | |
350 | if (!ms->in_sync && | |
351 | (log->type->get_sync_count(log) == ms->nr_regions)) { | |
352 | /* the sync is complete */ | |
353 | dm_table_event(ms->ti->table); | |
354 | ms->in_sync = 1; | |
355 | } | |
356 | } | |
357 | ||
358 | /*----------------------------------------------------------------- | |
359 | * Reads | |
360 | *---------------------------------------------------------------*/ | |
361 | static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector) | |
362 | { | |
06386bbf JB |
363 | struct mirror *m = get_default_mirror(ms); |
364 | ||
365 | do { | |
366 | if (likely(!atomic_read(&m->error_count))) | |
367 | return m; | |
368 | ||
369 | if (m-- == ms->mirror) | |
370 | m += ms->nr_mirrors; | |
371 | } while (m != get_default_mirror(ms)); | |
372 | ||
373 | return NULL; | |
374 | } | |
375 | ||
376 | static int default_ok(struct mirror *m) | |
377 | { | |
378 | struct mirror *default_mirror = get_default_mirror(m->ms); | |
379 | ||
380 | return !atomic_read(&default_mirror->error_count); | |
381 | } | |
382 | ||
383 | static int mirror_available(struct mirror_set *ms, struct bio *bio) | |
384 | { | |
1f965b19 HM |
385 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
386 | region_t region = dm_rh_bio_to_region(ms->rh, bio); | |
06386bbf | 387 | |
1f965b19 | 388 | if (log->type->in_sync(log, region, 0)) |
06386bbf JB |
389 | return choose_mirror(ms, bio->bi_sector) ? 1 : 0; |
390 | ||
391 | return 0; | |
1da177e4 LT |
392 | } |
393 | ||
394 | /* | |
395 | * remap a buffer to a particular mirror. | |
396 | */ | |
06386bbf JB |
397 | static sector_t map_sector(struct mirror *m, struct bio *bio) |
398 | { | |
399 | return m->offset + (bio->bi_sector - m->ms->ti->begin); | |
400 | } | |
401 | ||
402 | static void map_bio(struct mirror *m, struct bio *bio) | |
1da177e4 LT |
403 | { |
404 | bio->bi_bdev = m->dev->bdev; | |
06386bbf JB |
405 | bio->bi_sector = map_sector(m, bio); |
406 | } | |
407 | ||
22a1ceb1 | 408 | static void map_region(struct dm_io_region *io, struct mirror *m, |
06386bbf JB |
409 | struct bio *bio) |
410 | { | |
411 | io->bdev = m->dev->bdev; | |
412 | io->sector = map_sector(m, bio); | |
413 | io->count = bio->bi_size >> 9; | |
414 | } | |
415 | ||
416 | /*----------------------------------------------------------------- | |
417 | * Reads | |
418 | *---------------------------------------------------------------*/ | |
419 | static void read_callback(unsigned long error, void *context) | |
420 | { | |
421 | struct bio *bio = context; | |
422 | struct mirror *m; | |
423 | ||
424 | m = bio_get_m(bio); | |
425 | bio_set_m(bio, NULL); | |
426 | ||
427 | if (likely(!error)) { | |
428 | bio_endio(bio, 0); | |
429 | return; | |
430 | } | |
431 | ||
432 | fail_mirror(m, DM_RAID1_READ_ERROR); | |
433 | ||
434 | if (likely(default_ok(m)) || mirror_available(m->ms, bio)) { | |
435 | DMWARN_LIMIT("Read failure on mirror device %s. " | |
436 | "Trying alternative device.", | |
437 | m->dev->name); | |
438 | queue_bio(m->ms, bio, bio_rw(bio)); | |
439 | return; | |
440 | } | |
441 | ||
442 | DMERR_LIMIT("Read failure on mirror device %s. Failing I/O.", | |
443 | m->dev->name); | |
444 | bio_endio(bio, -EIO); | |
445 | } | |
446 | ||
447 | /* Asynchronous read. */ | |
448 | static void read_async_bio(struct mirror *m, struct bio *bio) | |
449 | { | |
22a1ceb1 | 450 | struct dm_io_region io; |
06386bbf JB |
451 | struct dm_io_request io_req = { |
452 | .bi_rw = READ, | |
453 | .mem.type = DM_IO_BVEC, | |
454 | .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx, | |
455 | .notify.fn = read_callback, | |
456 | .notify.context = bio, | |
457 | .client = m->ms->io_client, | |
458 | }; | |
459 | ||
460 | map_region(&io, m, bio); | |
461 | bio_set_m(bio, m); | |
1f965b19 HM |
462 | BUG_ON(dm_io(&io_req, 1, &io, NULL)); |
463 | } | |
464 | ||
465 | static inline int region_in_sync(struct mirror_set *ms, region_t region, | |
466 | int may_block) | |
467 | { | |
468 | int state = dm_rh_get_state(ms->rh, region, may_block); | |
469 | return state == DM_RH_CLEAN || state == DM_RH_DIRTY; | |
1da177e4 LT |
470 | } |
471 | ||
472 | static void do_reads(struct mirror_set *ms, struct bio_list *reads) | |
473 | { | |
474 | region_t region; | |
475 | struct bio *bio; | |
476 | struct mirror *m; | |
477 | ||
478 | while ((bio = bio_list_pop(reads))) { | |
1f965b19 | 479 | region = dm_rh_bio_to_region(ms->rh, bio); |
06386bbf | 480 | m = get_default_mirror(ms); |
1da177e4 LT |
481 | |
482 | /* | |
483 | * We can only read balance if the region is in sync. | |
484 | */ | |
1f965b19 | 485 | if (likely(region_in_sync(ms, region, 1))) |
1da177e4 | 486 | m = choose_mirror(ms, bio->bi_sector); |
06386bbf JB |
487 | else if (m && atomic_read(&m->error_count)) |
488 | m = NULL; | |
1da177e4 | 489 | |
06386bbf JB |
490 | if (likely(m)) |
491 | read_async_bio(m, bio); | |
492 | else | |
493 | bio_endio(bio, -EIO); | |
1da177e4 LT |
494 | } |
495 | } | |
496 | ||
497 | /*----------------------------------------------------------------- | |
498 | * Writes. | |
499 | * | |
500 | * We do different things with the write io depending on the | |
501 | * state of the region that it's in: | |
502 | * | |
503 | * SYNC: increment pending, use kcopyd to write to *all* mirrors | |
504 | * RECOVERING: delay the io until recovery completes | |
505 | * NOSYNC: increment pending, just write to the default mirror | |
506 | *---------------------------------------------------------------*/ | |
72f4b314 | 507 | |
72f4b314 | 508 | |
1da177e4 LT |
509 | static void write_callback(unsigned long error, void *context) |
510 | { | |
72f4b314 | 511 | unsigned i, ret = 0; |
1da177e4 LT |
512 | struct bio *bio = (struct bio *) context; |
513 | struct mirror_set *ms; | |
72f4b314 JB |
514 | int uptodate = 0; |
515 | int should_wake = 0; | |
516 | unsigned long flags; | |
1da177e4 | 517 | |
06386bbf JB |
518 | ms = bio_get_m(bio)->ms; |
519 | bio_set_m(bio, NULL); | |
1da177e4 LT |
520 | |
521 | /* | |
522 | * NOTE: We don't decrement the pending count here, | |
523 | * instead it is done by the targets endio function. | |
524 | * This way we handle both writes to SYNC and NOSYNC | |
525 | * regions with the same code. | |
526 | */ | |
72f4b314 JB |
527 | if (likely(!error)) |
528 | goto out; | |
1da177e4 | 529 | |
72f4b314 JB |
530 | for (i = 0; i < ms->nr_mirrors; i++) |
531 | if (test_bit(i, &error)) | |
532 | fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR); | |
533 | else | |
534 | uptodate = 1; | |
535 | ||
536 | if (unlikely(!uptodate)) { | |
537 | DMERR("All replicated volumes dead, failing I/O"); | |
538 | /* None of the writes succeeded, fail the I/O. */ | |
539 | ret = -EIO; | |
540 | } else if (errors_handled(ms)) { | |
1da177e4 | 541 | /* |
72f4b314 JB |
542 | * Need to raise event. Since raising |
543 | * events can block, we need to do it in | |
544 | * the main thread. | |
1da177e4 | 545 | */ |
72f4b314 JB |
546 | spin_lock_irqsave(&ms->lock, flags); |
547 | if (!ms->failures.head) | |
548 | should_wake = 1; | |
549 | bio_list_add(&ms->failures, bio); | |
550 | spin_unlock_irqrestore(&ms->lock, flags); | |
551 | if (should_wake) | |
1f965b19 | 552 | wakeup_mirrord(ms); |
72f4b314 | 553 | return; |
1da177e4 | 554 | } |
72f4b314 JB |
555 | out: |
556 | bio_endio(bio, ret); | |
1da177e4 LT |
557 | } |
558 | ||
559 | static void do_write(struct mirror_set *ms, struct bio *bio) | |
560 | { | |
561 | unsigned int i; | |
22a1ceb1 | 562 | struct dm_io_region io[ms->nr_mirrors], *dest = io; |
1da177e4 | 563 | struct mirror *m; |
88be163a MB |
564 | struct dm_io_request io_req = { |
565 | .bi_rw = WRITE, | |
566 | .mem.type = DM_IO_BVEC, | |
567 | .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx, | |
568 | .notify.fn = write_callback, | |
569 | .notify.context = bio, | |
570 | .client = ms->io_client, | |
571 | }; | |
1da177e4 | 572 | |
06386bbf JB |
573 | for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) |
574 | map_region(dest++, m, bio); | |
1da177e4 | 575 | |
06386bbf JB |
576 | /* |
577 | * Use default mirror because we only need it to retrieve the reference | |
578 | * to the mirror set in write_callback(). | |
579 | */ | |
580 | bio_set_m(bio, get_default_mirror(ms)); | |
88be163a | 581 | |
1f965b19 | 582 | BUG_ON(dm_io(&io_req, ms->nr_mirrors, io, NULL)); |
1da177e4 LT |
583 | } |
584 | ||
585 | static void do_writes(struct mirror_set *ms, struct bio_list *writes) | |
586 | { | |
587 | int state; | |
588 | struct bio *bio; | |
589 | struct bio_list sync, nosync, recover, *this_list = NULL; | |
7513c2a7 JB |
590 | struct bio_list requeue; |
591 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); | |
592 | region_t region; | |
1da177e4 LT |
593 | |
594 | if (!writes->head) | |
595 | return; | |
596 | ||
597 | /* | |
598 | * Classify each write. | |
599 | */ | |
600 | bio_list_init(&sync); | |
601 | bio_list_init(&nosync); | |
602 | bio_list_init(&recover); | |
7513c2a7 | 603 | bio_list_init(&requeue); |
1da177e4 LT |
604 | |
605 | while ((bio = bio_list_pop(writes))) { | |
7513c2a7 JB |
606 | region = dm_rh_bio_to_region(ms->rh, bio); |
607 | ||
608 | if (log->type->is_remote_recovering && | |
609 | log->type->is_remote_recovering(log, region)) { | |
610 | bio_list_add(&requeue, bio); | |
611 | continue; | |
612 | } | |
613 | ||
614 | state = dm_rh_get_state(ms->rh, region, 1); | |
1da177e4 | 615 | switch (state) { |
1f965b19 HM |
616 | case DM_RH_CLEAN: |
617 | case DM_RH_DIRTY: | |
1da177e4 LT |
618 | this_list = &sync; |
619 | break; | |
620 | ||
1f965b19 | 621 | case DM_RH_NOSYNC: |
1da177e4 LT |
622 | this_list = &nosync; |
623 | break; | |
624 | ||
1f965b19 | 625 | case DM_RH_RECOVERING: |
1da177e4 LT |
626 | this_list = &recover; |
627 | break; | |
628 | } | |
629 | ||
630 | bio_list_add(this_list, bio); | |
631 | } | |
632 | ||
7513c2a7 JB |
633 | /* |
634 | * Add bios that are delayed due to remote recovery | |
635 | * back on to the write queue | |
636 | */ | |
637 | if (unlikely(requeue.head)) { | |
638 | spin_lock_irq(&ms->lock); | |
639 | bio_list_merge(&ms->writes, &requeue); | |
640 | spin_unlock_irq(&ms->lock); | |
69885683 | 641 | delayed_wake(ms); |
7513c2a7 JB |
642 | } |
643 | ||
1da177e4 LT |
644 | /* |
645 | * Increment the pending counts for any regions that will | |
646 | * be written to (writes to recover regions are going to | |
647 | * be delayed). | |
648 | */ | |
1f965b19 HM |
649 | dm_rh_inc_pending(ms->rh, &sync); |
650 | dm_rh_inc_pending(ms->rh, &nosync); | |
d2b69864 JB |
651 | |
652 | /* | |
653 | * If the flush fails on a previous call and succeeds here, | |
654 | * we must not reset the log_failure variable. We need | |
655 | * userspace interaction to do that. | |
656 | */ | |
657 | ms->log_failure = dm_rh_flush(ms->rh) ? 1 : ms->log_failure; | |
1da177e4 LT |
658 | |
659 | /* | |
660 | * Dispatch io. | |
661 | */ | |
b80aa7a0 JB |
662 | if (unlikely(ms->log_failure)) { |
663 | spin_lock_irq(&ms->lock); | |
664 | bio_list_merge(&ms->failures, &sync); | |
665 | spin_unlock_irq(&ms->lock); | |
1f965b19 | 666 | wakeup_mirrord(ms); |
b80aa7a0 | 667 | } else |
fc1ff958 | 668 | while ((bio = bio_list_pop(&sync))) |
b80aa7a0 | 669 | do_write(ms, bio); |
1da177e4 LT |
670 | |
671 | while ((bio = bio_list_pop(&recover))) | |
1f965b19 | 672 | dm_rh_delay(ms->rh, bio); |
1da177e4 LT |
673 | |
674 | while ((bio = bio_list_pop(&nosync))) { | |
06386bbf | 675 | map_bio(get_default_mirror(ms), bio); |
1da177e4 LT |
676 | generic_make_request(bio); |
677 | } | |
678 | } | |
679 | ||
72f4b314 JB |
680 | static void do_failures(struct mirror_set *ms, struct bio_list *failures) |
681 | { | |
682 | struct bio *bio; | |
683 | ||
684 | if (!failures->head) | |
685 | return; | |
686 | ||
b80aa7a0 | 687 | if (!ms->log_failure) { |
b34578a4 | 688 | while ((bio = bio_list_pop(failures))) { |
1f965b19 HM |
689 | ms->in_sync = 0; |
690 | dm_rh_mark_nosync(ms->rh, bio, bio->bi_size, 0); | |
b34578a4 | 691 | } |
b80aa7a0 JB |
692 | return; |
693 | } | |
694 | ||
695 | /* | |
696 | * If the log has failed, unattempted writes are being | |
697 | * put on the failures list. We can't issue those writes | |
698 | * until a log has been marked, so we must store them. | |
699 | * | |
700 | * If a 'noflush' suspend is in progress, we can requeue | |
701 | * the I/O's to the core. This give userspace a chance | |
702 | * to reconfigure the mirror, at which point the core | |
703 | * will reissue the writes. If the 'noflush' flag is | |
704 | * not set, we have no choice but to return errors. | |
705 | * | |
706 | * Some writes on the failures list may have been | |
707 | * submitted before the log failure and represent a | |
708 | * failure to write to one of the devices. It is ok | |
709 | * for us to treat them the same and requeue them | |
710 | * as well. | |
711 | */ | |
712 | if (dm_noflush_suspending(ms->ti)) { | |
713 | while ((bio = bio_list_pop(failures))) | |
714 | bio_endio(bio, DM_ENDIO_REQUEUE); | |
715 | return; | |
716 | } | |
717 | ||
718 | if (atomic_read(&ms->suspend)) { | |
719 | while ((bio = bio_list_pop(failures))) | |
720 | bio_endio(bio, -EIO); | |
721 | return; | |
722 | } | |
723 | ||
724 | spin_lock_irq(&ms->lock); | |
725 | bio_list_merge(&ms->failures, failures); | |
726 | spin_unlock_irq(&ms->lock); | |
727 | ||
a2aebe03 | 728 | delayed_wake(ms); |
72f4b314 JB |
729 | } |
730 | ||
731 | static void trigger_event(struct work_struct *work) | |
732 | { | |
733 | struct mirror_set *ms = | |
734 | container_of(work, struct mirror_set, trigger_event); | |
735 | ||
736 | dm_table_event(ms->ti->table); | |
737 | } | |
738 | ||
1da177e4 LT |
739 | /*----------------------------------------------------------------- |
740 | * kmirrord | |
741 | *---------------------------------------------------------------*/ | |
a2aebe03 | 742 | static void do_mirror(struct work_struct *work) |
1da177e4 | 743 | { |
1f965b19 HM |
744 | struct mirror_set *ms = container_of(work, struct mirror_set, |
745 | kmirrord_work); | |
72f4b314 JB |
746 | struct bio_list reads, writes, failures; |
747 | unsigned long flags; | |
1da177e4 | 748 | |
72f4b314 | 749 | spin_lock_irqsave(&ms->lock, flags); |
1da177e4 LT |
750 | reads = ms->reads; |
751 | writes = ms->writes; | |
72f4b314 | 752 | failures = ms->failures; |
1da177e4 LT |
753 | bio_list_init(&ms->reads); |
754 | bio_list_init(&ms->writes); | |
72f4b314 JB |
755 | bio_list_init(&ms->failures); |
756 | spin_unlock_irqrestore(&ms->lock, flags); | |
1da177e4 | 757 | |
1f965b19 | 758 | dm_rh_update_states(ms->rh, errors_handled(ms)); |
1da177e4 LT |
759 | do_recovery(ms); |
760 | do_reads(ms, &reads); | |
761 | do_writes(ms, &writes); | |
72f4b314 | 762 | do_failures(ms, &failures); |
7ff14a36 MP |
763 | |
764 | dm_table_unplug_all(ms->ti->table); | |
1da177e4 LT |
765 | } |
766 | ||
1da177e4 LT |
767 | /*----------------------------------------------------------------- |
768 | * Target functions | |
769 | *---------------------------------------------------------------*/ | |
770 | static struct mirror_set *alloc_context(unsigned int nr_mirrors, | |
771 | uint32_t region_size, | |
772 | struct dm_target *ti, | |
416cd17b | 773 | struct dm_dirty_log *dl) |
1da177e4 LT |
774 | { |
775 | size_t len; | |
776 | struct mirror_set *ms = NULL; | |
777 | ||
1da177e4 LT |
778 | len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors); |
779 | ||
dd00cc48 | 780 | ms = kzalloc(len, GFP_KERNEL); |
1da177e4 | 781 | if (!ms) { |
72d94861 | 782 | ti->error = "Cannot allocate mirror context"; |
1da177e4 LT |
783 | return NULL; |
784 | } | |
785 | ||
1da177e4 LT |
786 | spin_lock_init(&ms->lock); |
787 | ||
788 | ms->ti = ti; | |
789 | ms->nr_mirrors = nr_mirrors; | |
790 | ms->nr_regions = dm_sector_div_up(ti->len, region_size); | |
791 | ms->in_sync = 0; | |
b80aa7a0 JB |
792 | ms->log_failure = 0; |
793 | atomic_set(&ms->suspend, 0); | |
72f4b314 | 794 | atomic_set(&ms->default_mirror, DEFAULT_MIRROR); |
1da177e4 | 795 | |
95f8fac8 MP |
796 | ms->read_record_pool = mempool_create_slab_pool(MIN_READ_RECORDS, |
797 | _dm_raid1_read_record_cache); | |
798 | ||
06386bbf JB |
799 | if (!ms->read_record_pool) { |
800 | ti->error = "Error creating mirror read_record_pool"; | |
801 | kfree(ms); | |
802 | return NULL; | |
803 | } | |
804 | ||
88be163a MB |
805 | ms->io_client = dm_io_client_create(DM_IO_PAGES); |
806 | if (IS_ERR(ms->io_client)) { | |
807 | ti->error = "Error creating dm_io client"; | |
06386bbf | 808 | mempool_destroy(ms->read_record_pool); |
88be163a MB |
809 | kfree(ms); |
810 | return NULL; | |
811 | } | |
812 | ||
1f965b19 HM |
813 | ms->rh = dm_region_hash_create(ms, dispatch_bios, wakeup_mirrord, |
814 | wakeup_all_recovery_waiters, | |
815 | ms->ti->begin, MAX_RECOVERY, | |
816 | dl, region_size, ms->nr_regions); | |
817 | if (IS_ERR(ms->rh)) { | |
72d94861 | 818 | ti->error = "Error creating dirty region hash"; |
a72cf737 | 819 | dm_io_client_destroy(ms->io_client); |
06386bbf | 820 | mempool_destroy(ms->read_record_pool); |
1da177e4 LT |
821 | kfree(ms); |
822 | return NULL; | |
823 | } | |
824 | ||
825 | return ms; | |
826 | } | |
827 | ||
828 | static void free_context(struct mirror_set *ms, struct dm_target *ti, | |
829 | unsigned int m) | |
830 | { | |
831 | while (m--) | |
832 | dm_put_device(ti, ms->mirror[m].dev); | |
833 | ||
88be163a | 834 | dm_io_client_destroy(ms->io_client); |
1f965b19 | 835 | dm_region_hash_destroy(ms->rh); |
06386bbf | 836 | mempool_destroy(ms->read_record_pool); |
1da177e4 LT |
837 | kfree(ms); |
838 | } | |
839 | ||
1da177e4 LT |
840 | static int get_mirror(struct mirror_set *ms, struct dm_target *ti, |
841 | unsigned int mirror, char **argv) | |
842 | { | |
4ee218cd | 843 | unsigned long long offset; |
1da177e4 | 844 | |
4ee218cd | 845 | if (sscanf(argv[1], "%llu", &offset) != 1) { |
72d94861 | 846 | ti->error = "Invalid offset"; |
1da177e4 LT |
847 | return -EINVAL; |
848 | } | |
849 | ||
850 | if (dm_get_device(ti, argv[0], offset, ti->len, | |
851 | dm_table_get_mode(ti->table), | |
852 | &ms->mirror[mirror].dev)) { | |
72d94861 | 853 | ti->error = "Device lookup failure"; |
1da177e4 LT |
854 | return -ENXIO; |
855 | } | |
856 | ||
aa5617c5 | 857 | ms->mirror[mirror].ms = ms; |
72f4b314 JB |
858 | atomic_set(&(ms->mirror[mirror].error_count), 0); |
859 | ms->mirror[mirror].error_type = 0; | |
1da177e4 LT |
860 | ms->mirror[mirror].offset = offset; |
861 | ||
862 | return 0; | |
863 | } | |
864 | ||
1da177e4 LT |
865 | /* |
866 | * Create dirty log: log_type #log_params <log_params> | |
867 | */ | |
416cd17b | 868 | static struct dm_dirty_log *create_dirty_log(struct dm_target *ti, |
1f965b19 HM |
869 | unsigned argc, char **argv, |
870 | unsigned *args_used) | |
1da177e4 | 871 | { |
1f965b19 | 872 | unsigned param_count; |
416cd17b | 873 | struct dm_dirty_log *dl; |
1da177e4 LT |
874 | |
875 | if (argc < 2) { | |
72d94861 | 876 | ti->error = "Insufficient mirror log arguments"; |
1da177e4 LT |
877 | return NULL; |
878 | } | |
879 | ||
880 | if (sscanf(argv[1], "%u", ¶m_count) != 1) { | |
72d94861 | 881 | ti->error = "Invalid mirror log argument count"; |
1da177e4 LT |
882 | return NULL; |
883 | } | |
884 | ||
885 | *args_used = 2 + param_count; | |
886 | ||
887 | if (argc < *args_used) { | |
72d94861 | 888 | ti->error = "Insufficient mirror log arguments"; |
1da177e4 LT |
889 | return NULL; |
890 | } | |
891 | ||
416cd17b | 892 | dl = dm_dirty_log_create(argv[0], ti, param_count, argv + 2); |
1da177e4 | 893 | if (!dl) { |
72d94861 | 894 | ti->error = "Error creating mirror dirty log"; |
1da177e4 LT |
895 | return NULL; |
896 | } | |
897 | ||
1da177e4 LT |
898 | return dl; |
899 | } | |
900 | ||
a8e6afa2 JB |
901 | static int parse_features(struct mirror_set *ms, unsigned argc, char **argv, |
902 | unsigned *args_used) | |
903 | { | |
904 | unsigned num_features; | |
905 | struct dm_target *ti = ms->ti; | |
906 | ||
907 | *args_used = 0; | |
908 | ||
909 | if (!argc) | |
910 | return 0; | |
911 | ||
912 | if (sscanf(argv[0], "%u", &num_features) != 1) { | |
913 | ti->error = "Invalid number of features"; | |
914 | return -EINVAL; | |
915 | } | |
916 | ||
917 | argc--; | |
918 | argv++; | |
919 | (*args_used)++; | |
920 | ||
921 | if (num_features > argc) { | |
922 | ti->error = "Not enough arguments to support feature count"; | |
923 | return -EINVAL; | |
924 | } | |
925 | ||
926 | if (!strcmp("handle_errors", argv[0])) | |
927 | ms->features |= DM_RAID1_HANDLE_ERRORS; | |
928 | else { | |
929 | ti->error = "Unrecognised feature requested"; | |
930 | return -EINVAL; | |
931 | } | |
932 | ||
933 | (*args_used)++; | |
934 | ||
935 | return 0; | |
936 | } | |
937 | ||
1da177e4 LT |
938 | /* |
939 | * Construct a mirror mapping: | |
940 | * | |
941 | * log_type #log_params <log_params> | |
942 | * #mirrors [mirror_path offset]{2,} | |
a8e6afa2 | 943 | * [#features <features>] |
1da177e4 LT |
944 | * |
945 | * log_type is "core" or "disk" | |
946 | * #log_params is between 1 and 3 | |
a8e6afa2 JB |
947 | * |
948 | * If present, features must be "handle_errors". | |
1da177e4 | 949 | */ |
1da177e4 LT |
950 | static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
951 | { | |
952 | int r; | |
953 | unsigned int nr_mirrors, m, args_used; | |
954 | struct mirror_set *ms; | |
416cd17b | 955 | struct dm_dirty_log *dl; |
1da177e4 LT |
956 | |
957 | dl = create_dirty_log(ti, argc, argv, &args_used); | |
958 | if (!dl) | |
959 | return -EINVAL; | |
960 | ||
961 | argv += args_used; | |
962 | argc -= args_used; | |
963 | ||
964 | if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 || | |
eb69aca5 | 965 | nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) { |
72d94861 | 966 | ti->error = "Invalid number of mirrors"; |
416cd17b | 967 | dm_dirty_log_destroy(dl); |
1da177e4 LT |
968 | return -EINVAL; |
969 | } | |
970 | ||
971 | argv++, argc--; | |
972 | ||
a8e6afa2 JB |
973 | if (argc < nr_mirrors * 2) { |
974 | ti->error = "Too few mirror arguments"; | |
416cd17b | 975 | dm_dirty_log_destroy(dl); |
1da177e4 LT |
976 | return -EINVAL; |
977 | } | |
978 | ||
979 | ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl); | |
980 | if (!ms) { | |
416cd17b | 981 | dm_dirty_log_destroy(dl); |
1da177e4 LT |
982 | return -ENOMEM; |
983 | } | |
984 | ||
985 | /* Get the mirror parameter sets */ | |
986 | for (m = 0; m < nr_mirrors; m++) { | |
987 | r = get_mirror(ms, ti, m, argv); | |
988 | if (r) { | |
989 | free_context(ms, ti, m); | |
990 | return r; | |
991 | } | |
992 | argv += 2; | |
993 | argc -= 2; | |
994 | } | |
995 | ||
996 | ti->private = ms; | |
1f965b19 | 997 | ti->split_io = dm_rh_get_region_size(ms->rh); |
1da177e4 | 998 | |
6ad36fe2 HS |
999 | ms->kmirrord_wq = create_singlethread_workqueue("kmirrord"); |
1000 | if (!ms->kmirrord_wq) { | |
1001 | DMERR("couldn't start kmirrord"); | |
a72cf737 DM |
1002 | r = -ENOMEM; |
1003 | goto err_free_context; | |
6ad36fe2 HS |
1004 | } |
1005 | INIT_WORK(&ms->kmirrord_work, do_mirror); | |
a2aebe03 MP |
1006 | init_timer(&ms->timer); |
1007 | ms->timer_pending = 0; | |
72f4b314 | 1008 | INIT_WORK(&ms->trigger_event, trigger_event); |
6ad36fe2 | 1009 | |
a8e6afa2 | 1010 | r = parse_features(ms, argc, argv, &args_used); |
a72cf737 DM |
1011 | if (r) |
1012 | goto err_destroy_wq; | |
a8e6afa2 JB |
1013 | |
1014 | argv += args_used; | |
1015 | argc -= args_used; | |
1016 | ||
f44db678 JB |
1017 | /* |
1018 | * Any read-balancing addition depends on the | |
1019 | * DM_RAID1_HANDLE_ERRORS flag being present. | |
1020 | * This is because the decision to balance depends | |
1021 | * on the sync state of a region. If the above | |
1022 | * flag is not present, we ignore errors; and | |
1023 | * the sync state may be inaccurate. | |
1024 | */ | |
1025 | ||
a8e6afa2 JB |
1026 | if (argc) { |
1027 | ti->error = "Too many mirror arguments"; | |
a72cf737 DM |
1028 | r = -EINVAL; |
1029 | goto err_destroy_wq; | |
a8e6afa2 JB |
1030 | } |
1031 | ||
1f965b19 | 1032 | r = dm_kcopyd_client_create(DM_KCOPYD_PAGES, &ms->kcopyd_client); |
a72cf737 DM |
1033 | if (r) |
1034 | goto err_destroy_wq; | |
1da177e4 | 1035 | |
1f965b19 | 1036 | wakeup_mirrord(ms); |
1da177e4 | 1037 | return 0; |
a72cf737 DM |
1038 | |
1039 | err_destroy_wq: | |
1040 | destroy_workqueue(ms->kmirrord_wq); | |
1041 | err_free_context: | |
1042 | free_context(ms, ti, ms->nr_mirrors); | |
1043 | return r; | |
1da177e4 LT |
1044 | } |
1045 | ||
1046 | static void mirror_dtr(struct dm_target *ti) | |
1047 | { | |
1048 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1049 | ||
a2aebe03 | 1050 | del_timer_sync(&ms->timer); |
6ad36fe2 | 1051 | flush_workqueue(ms->kmirrord_wq); |
18776c73 | 1052 | flush_scheduled_work(); |
eb69aca5 | 1053 | dm_kcopyd_client_destroy(ms->kcopyd_client); |
6ad36fe2 | 1054 | destroy_workqueue(ms->kmirrord_wq); |
1da177e4 LT |
1055 | free_context(ms, ti, ms->nr_mirrors); |
1056 | } | |
1057 | ||
1da177e4 LT |
1058 | /* |
1059 | * Mirror mapping function | |
1060 | */ | |
1061 | static int mirror_map(struct dm_target *ti, struct bio *bio, | |
1062 | union map_info *map_context) | |
1063 | { | |
1064 | int r, rw = bio_rw(bio); | |
1065 | struct mirror *m; | |
1066 | struct mirror_set *ms = ti->private; | |
06386bbf | 1067 | struct dm_raid1_read_record *read_record = NULL; |
1f965b19 | 1068 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
1da177e4 LT |
1069 | |
1070 | if (rw == WRITE) { | |
06386bbf | 1071 | /* Save region for mirror_end_io() handler */ |
1f965b19 | 1072 | map_context->ll = dm_rh_bio_to_region(ms->rh, bio); |
1da177e4 | 1073 | queue_bio(ms, bio, rw); |
d2a7ad29 | 1074 | return DM_MAPIO_SUBMITTED; |
1da177e4 LT |
1075 | } |
1076 | ||
1f965b19 | 1077 | r = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0); |
1da177e4 LT |
1078 | if (r < 0 && r != -EWOULDBLOCK) |
1079 | return r; | |
1080 | ||
1da177e4 | 1081 | /* |
06386bbf | 1082 | * If region is not in-sync queue the bio. |
1da177e4 | 1083 | */ |
06386bbf JB |
1084 | if (!r || (r == -EWOULDBLOCK)) { |
1085 | if (rw == READA) | |
1086 | return -EWOULDBLOCK; | |
1da177e4 | 1087 | |
1da177e4 | 1088 | queue_bio(ms, bio, rw); |
d2a7ad29 | 1089 | return DM_MAPIO_SUBMITTED; |
1da177e4 LT |
1090 | } |
1091 | ||
06386bbf JB |
1092 | /* |
1093 | * The region is in-sync and we can perform reads directly. | |
1094 | * Store enough information so we can retry if it fails. | |
1095 | */ | |
1da177e4 | 1096 | m = choose_mirror(ms, bio->bi_sector); |
06386bbf | 1097 | if (unlikely(!m)) |
1da177e4 LT |
1098 | return -EIO; |
1099 | ||
06386bbf JB |
1100 | read_record = mempool_alloc(ms->read_record_pool, GFP_NOIO); |
1101 | if (likely(read_record)) { | |
1102 | dm_bio_record(&read_record->details, bio); | |
1103 | map_context->ptr = read_record; | |
1104 | read_record->m = m; | |
1105 | } | |
1106 | ||
1107 | map_bio(m, bio); | |
1108 | ||
d2a7ad29 | 1109 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
1110 | } |
1111 | ||
1112 | static int mirror_end_io(struct dm_target *ti, struct bio *bio, | |
1113 | int error, union map_info *map_context) | |
1114 | { | |
1115 | int rw = bio_rw(bio); | |
1116 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
06386bbf JB |
1117 | struct mirror *m = NULL; |
1118 | struct dm_bio_details *bd = NULL; | |
1119 | struct dm_raid1_read_record *read_record = map_context->ptr; | |
1da177e4 LT |
1120 | |
1121 | /* | |
1122 | * We need to dec pending if this was a write. | |
1123 | */ | |
06386bbf | 1124 | if (rw == WRITE) { |
1f965b19 | 1125 | dm_rh_dec(ms->rh, map_context->ll); |
06386bbf JB |
1126 | return error; |
1127 | } | |
1da177e4 | 1128 | |
06386bbf JB |
1129 | if (error == -EOPNOTSUPP) |
1130 | goto out; | |
1131 | ||
1f98a13f | 1132 | if ((error == -EWOULDBLOCK) && bio_rw_flagged(bio, BIO_RW_AHEAD)) |
06386bbf JB |
1133 | goto out; |
1134 | ||
1135 | if (unlikely(error)) { | |
1136 | if (!read_record) { | |
1137 | /* | |
1138 | * There wasn't enough memory to record necessary | |
1139 | * information for a retry or there was no other | |
1140 | * mirror in-sync. | |
1141 | */ | |
e03f1a84 | 1142 | DMERR_LIMIT("Mirror read failed."); |
06386bbf JB |
1143 | return -EIO; |
1144 | } | |
e03f1a84 AB |
1145 | |
1146 | m = read_record->m; | |
1147 | ||
06386bbf JB |
1148 | DMERR("Mirror read failed from %s. Trying alternative device.", |
1149 | m->dev->name); | |
1150 | ||
06386bbf JB |
1151 | fail_mirror(m, DM_RAID1_READ_ERROR); |
1152 | ||
1153 | /* | |
1154 | * A failed read is requeued for another attempt using an intact | |
1155 | * mirror. | |
1156 | */ | |
1157 | if (default_ok(m) || mirror_available(ms, bio)) { | |
1158 | bd = &read_record->details; | |
1159 | ||
1160 | dm_bio_restore(bd, bio); | |
1161 | mempool_free(read_record, ms->read_record_pool); | |
1162 | map_context->ptr = NULL; | |
1163 | queue_bio(ms, bio, rw); | |
1164 | return 1; | |
1165 | } | |
1166 | DMERR("All replicated volumes dead, failing I/O"); | |
1167 | } | |
1168 | ||
1169 | out: | |
1170 | if (read_record) { | |
1171 | mempool_free(read_record, ms->read_record_pool); | |
1172 | map_context->ptr = NULL; | |
1173 | } | |
1174 | ||
1175 | return error; | |
1da177e4 LT |
1176 | } |
1177 | ||
b80aa7a0 | 1178 | static void mirror_presuspend(struct dm_target *ti) |
1da177e4 LT |
1179 | { |
1180 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1f965b19 | 1181 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
1da177e4 | 1182 | |
b80aa7a0 JB |
1183 | atomic_set(&ms->suspend, 1); |
1184 | ||
1185 | /* | |
1186 | * We must finish up all the work that we've | |
1187 | * generated (i.e. recovery work). | |
1188 | */ | |
1f965b19 | 1189 | dm_rh_stop_recovery(ms->rh); |
33184048 | 1190 | |
33184048 | 1191 | wait_event(_kmirrord_recovery_stopped, |
1f965b19 | 1192 | !dm_rh_recovery_in_flight(ms->rh)); |
33184048 | 1193 | |
b80aa7a0 JB |
1194 | if (log->type->presuspend && log->type->presuspend(log)) |
1195 | /* FIXME: need better error handling */ | |
1196 | DMWARN("log presuspend failed"); | |
1197 | ||
1198 | /* | |
1199 | * Now that recovery is complete/stopped and the | |
1200 | * delayed bios are queued, we need to wait for | |
1201 | * the worker thread to complete. This way, | |
1202 | * we know that all of our I/O has been pushed. | |
1203 | */ | |
1204 | flush_workqueue(ms->kmirrord_wq); | |
1205 | } | |
1206 | ||
1207 | static void mirror_postsuspend(struct dm_target *ti) | |
1208 | { | |
1209 | struct mirror_set *ms = ti->private; | |
1f965b19 | 1210 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
b80aa7a0 | 1211 | |
6b3df0d7 | 1212 | if (log->type->postsuspend && log->type->postsuspend(log)) |
1da177e4 | 1213 | /* FIXME: need better error handling */ |
b80aa7a0 | 1214 | DMWARN("log postsuspend failed"); |
1da177e4 LT |
1215 | } |
1216 | ||
1217 | static void mirror_resume(struct dm_target *ti) | |
1218 | { | |
b80aa7a0 | 1219 | struct mirror_set *ms = ti->private; |
1f965b19 | 1220 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
b80aa7a0 JB |
1221 | |
1222 | atomic_set(&ms->suspend, 0); | |
1da177e4 LT |
1223 | if (log->type->resume && log->type->resume(log)) |
1224 | /* FIXME: need better error handling */ | |
1225 | DMWARN("log resume failed"); | |
1f965b19 | 1226 | dm_rh_start_recovery(ms->rh); |
1da177e4 LT |
1227 | } |
1228 | ||
af195ac8 JB |
1229 | /* |
1230 | * device_status_char | |
1231 | * @m: mirror device/leg we want the status of | |
1232 | * | |
1233 | * We return one character representing the most severe error | |
1234 | * we have encountered. | |
1235 | * A => Alive - No failures | |
1236 | * D => Dead - A write failure occurred leaving mirror out-of-sync | |
1237 | * S => Sync - A sychronization failure occurred, mirror out-of-sync | |
1238 | * R => Read - A read failure occurred, mirror data unaffected | |
1239 | * | |
1240 | * Returns: <char> | |
1241 | */ | |
1242 | static char device_status_char(struct mirror *m) | |
1243 | { | |
1244 | if (!atomic_read(&(m->error_count))) | |
1245 | return 'A'; | |
1246 | ||
1247 | return (test_bit(DM_RAID1_WRITE_ERROR, &(m->error_type))) ? 'D' : | |
1248 | (test_bit(DM_RAID1_SYNC_ERROR, &(m->error_type))) ? 'S' : | |
1249 | (test_bit(DM_RAID1_READ_ERROR, &(m->error_type))) ? 'R' : 'U'; | |
1250 | } | |
1251 | ||
1252 | ||
1da177e4 LT |
1253 | static int mirror_status(struct dm_target *ti, status_type_t type, |
1254 | char *result, unsigned int maxlen) | |
1255 | { | |
315dcc22 | 1256 | unsigned int m, sz = 0; |
1da177e4 | 1257 | struct mirror_set *ms = (struct mirror_set *) ti->private; |
1f965b19 | 1258 | struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); |
af195ac8 | 1259 | char buffer[ms->nr_mirrors + 1]; |
1da177e4 | 1260 | |
1da177e4 LT |
1261 | switch (type) { |
1262 | case STATUSTYPE_INFO: | |
1263 | DMEMIT("%d ", ms->nr_mirrors); | |
af195ac8 | 1264 | for (m = 0; m < ms->nr_mirrors; m++) { |
1da177e4 | 1265 | DMEMIT("%s ", ms->mirror[m].dev->name); |
af195ac8 JB |
1266 | buffer[m] = device_status_char(&(ms->mirror[m])); |
1267 | } | |
1268 | buffer[m] = '\0'; | |
1da177e4 | 1269 | |
af195ac8 | 1270 | DMEMIT("%llu/%llu 1 %s ", |
1f965b19 | 1271 | (unsigned long long)log->type->get_sync_count(log), |
af195ac8 | 1272 | (unsigned long long)ms->nr_regions, buffer); |
315dcc22 | 1273 | |
1f965b19 | 1274 | sz += log->type->status(log, type, result+sz, maxlen-sz); |
315dcc22 | 1275 | |
1da177e4 LT |
1276 | break; |
1277 | ||
1278 | case STATUSTYPE_TABLE: | |
1f965b19 | 1279 | sz = log->type->status(log, type, result, maxlen); |
315dcc22 | 1280 | |
e52b8f6d | 1281 | DMEMIT("%d", ms->nr_mirrors); |
1da177e4 | 1282 | for (m = 0; m < ms->nr_mirrors; m++) |
e52b8f6d | 1283 | DMEMIT(" %s %llu", ms->mirror[m].dev->name, |
b80aa7a0 | 1284 | (unsigned long long)ms->mirror[m].offset); |
a8e6afa2 JB |
1285 | |
1286 | if (ms->features & DM_RAID1_HANDLE_ERRORS) | |
1287 | DMEMIT(" 1 handle_errors"); | |
1da177e4 LT |
1288 | } |
1289 | ||
1290 | return 0; | |
1291 | } | |
1292 | ||
af4874e0 MS |
1293 | static int mirror_iterate_devices(struct dm_target *ti, |
1294 | iterate_devices_callout_fn fn, void *data) | |
1295 | { | |
1296 | struct mirror_set *ms = ti->private; | |
1297 | int ret = 0; | |
1298 | unsigned i; | |
1299 | ||
1300 | for (i = 0; !ret && i < ms->nr_mirrors; i++) | |
1301 | ret = fn(ti, ms->mirror[i].dev, | |
5dea271b | 1302 | ms->mirror[i].offset, ti->len, data); |
af4874e0 MS |
1303 | |
1304 | return ret; | |
1305 | } | |
1306 | ||
1da177e4 LT |
1307 | static struct target_type mirror_target = { |
1308 | .name = "mirror", | |
af4874e0 | 1309 | .version = {1, 12, 0}, |
1da177e4 LT |
1310 | .module = THIS_MODULE, |
1311 | .ctr = mirror_ctr, | |
1312 | .dtr = mirror_dtr, | |
1313 | .map = mirror_map, | |
1314 | .end_io = mirror_end_io, | |
b80aa7a0 | 1315 | .presuspend = mirror_presuspend, |
1da177e4 LT |
1316 | .postsuspend = mirror_postsuspend, |
1317 | .resume = mirror_resume, | |
1318 | .status = mirror_status, | |
af4874e0 | 1319 | .iterate_devices = mirror_iterate_devices, |
1da177e4 LT |
1320 | }; |
1321 | ||
1322 | static int __init dm_mirror_init(void) | |
1323 | { | |
1324 | int r; | |
1325 | ||
95f8fac8 MP |
1326 | _dm_raid1_read_record_cache = KMEM_CACHE(dm_raid1_read_record, 0); |
1327 | if (!_dm_raid1_read_record_cache) { | |
1328 | DMERR("Can't allocate dm_raid1_read_record cache"); | |
1329 | r = -ENOMEM; | |
1330 | goto bad_cache; | |
1331 | } | |
1332 | ||
1da177e4 | 1333 | r = dm_register_target(&mirror_target); |
95f8fac8 | 1334 | if (r < 0) { |
0cd33124 | 1335 | DMERR("Failed to register mirror target"); |
95f8fac8 MP |
1336 | goto bad_target; |
1337 | } | |
1338 | ||
1339 | return 0; | |
1da177e4 | 1340 | |
95f8fac8 MP |
1341 | bad_target: |
1342 | kmem_cache_destroy(_dm_raid1_read_record_cache); | |
1343 | bad_cache: | |
1da177e4 LT |
1344 | return r; |
1345 | } | |
1346 | ||
1347 | static void __exit dm_mirror_exit(void) | |
1348 | { | |
10d3bd09 | 1349 | dm_unregister_target(&mirror_target); |
95f8fac8 | 1350 | kmem_cache_destroy(_dm_raid1_read_record_cache); |
1da177e4 LT |
1351 | } |
1352 | ||
1353 | /* Module hooks */ | |
1354 | module_init(dm_mirror_init); | |
1355 | module_exit(dm_mirror_exit); | |
1356 | ||
1357 | MODULE_DESCRIPTION(DM_NAME " mirror target"); | |
1358 | MODULE_AUTHOR("Joe Thornber"); | |
1359 | MODULE_LICENSE("GPL"); |