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sh_eth: fix EESIPR values for SH77{34|63}
[linux/fpc-iii.git] / drivers / md / bcache / super.c
blob3a19cbc8b230e5a7b77cafa89427b8e282c251dc
1 /*
2 * bcache setup/teardown code, and some metadata io - read a superblock and
3 * figure out what to do with it.
4 *
5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6 * Copyright 2012 Google, Inc.
7 */
8
9 #include "bcache.h"
10 #include "btree.h"
11 #include "debug.h"
12 #include "extents.h"
13 #include "request.h"
14 #include "writeback.h"
15
16 #include <linux/blkdev.h>
17 #include <linux/buffer_head.h>
18 #include <linux/debugfs.h>
19 #include <linux/genhd.h>
20 #include <linux/idr.h>
21 #include <linux/kthread.h>
22 #include <linux/module.h>
23 #include <linux/random.h>
24 #include <linux/reboot.h>
25 #include <linux/sysfs.h>
26
27 MODULE_LICENSE("GPL");
28 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
29
30 static const char bcache_magic[] = {
31 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
32 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
33 };
34
35 static const char invalid_uuid[] = {
36 0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78,
37 0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99
38 };
39
40 /* Default is -1; we skip past it for struct cached_dev's cache mode */
41 const char * const bch_cache_modes[] = {
42 "default",
43 "writethrough",
44 "writeback",
45 "writearound",
46 "none",
47 NULL
48 };
49
50 static struct kobject *bcache_kobj;
51 struct mutex bch_register_lock;
52 LIST_HEAD(bch_cache_sets);
53 static LIST_HEAD(uncached_devices);
54
55 static int bcache_major;
56 static DEFINE_IDA(bcache_minor);
57 static wait_queue_head_t unregister_wait;
58 struct workqueue_struct *bcache_wq;
59
60 #define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE)
61 #define BCACHE_MINORS 16 /* partition support */
62
63 /* Superblock */
64
65 static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
66 struct page **res)
67 {
68 const char *err;
69 struct cache_sb *s;
70 struct buffer_head *bh = __bread(bdev, 1, SB_SIZE);
71 unsigned i;
72
73 if (!bh)
74 return "IO error";
75
76 s = (struct cache_sb *) bh->b_data;
77
78 sb->offset = le64_to_cpu(s->offset);
79 sb->version = le64_to_cpu(s->version);
80
81 memcpy(sb->magic, s->magic, 16);
82 memcpy(sb->uuid, s->uuid, 16);
83 memcpy(sb->set_uuid, s->set_uuid, 16);
84 memcpy(sb->label, s->label, SB_LABEL_SIZE);
85
86 sb->flags = le64_to_cpu(s->flags);
87 sb->seq = le64_to_cpu(s->seq);
88 sb->last_mount = le32_to_cpu(s->last_mount);
89 sb->first_bucket = le16_to_cpu(s->first_bucket);
90 sb->keys = le16_to_cpu(s->keys);
91
92 for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
93 sb->d[i] = le64_to_cpu(s->d[i]);
94
95 pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
96 sb->version, sb->flags, sb->seq, sb->keys);
97
98 err = "Not a bcache superblock";
99 if (sb->offset != SB_SECTOR)
100 goto err;
101
102 if (memcmp(sb->magic, bcache_magic, 16))
103 goto err;
104
105 err = "Too many journal buckets";
106 if (sb->keys > SB_JOURNAL_BUCKETS)
107 goto err;
108
109 err = "Bad checksum";
110 if (s->csum != csum_set(s))
111 goto err;
112
113 err = "Bad UUID";
114 if (bch_is_zero(sb->uuid, 16))
115 goto err;
116
117 sb->block_size = le16_to_cpu(s->block_size);
118
119 err = "Superblock block size smaller than device block size";
120 if (sb->block_size << 9 < bdev_logical_block_size(bdev))
121 goto err;
122
123 switch (sb->version) {
124 case BCACHE_SB_VERSION_BDEV:
125 sb->data_offset = BDEV_DATA_START_DEFAULT;
126 break;
127 case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
128 sb->data_offset = le64_to_cpu(s->data_offset);
129
130 err = "Bad data offset";
131 if (sb->data_offset < BDEV_DATA_START_DEFAULT)
132 goto err;
133
134 break;
135 case BCACHE_SB_VERSION_CDEV:
136 case BCACHE_SB_VERSION_CDEV_WITH_UUID:
137 sb->nbuckets = le64_to_cpu(s->nbuckets);
138 sb->bucket_size = le16_to_cpu(s->bucket_size);
139
140 sb->nr_in_set = le16_to_cpu(s->nr_in_set);
141 sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
142
143 err = "Too many buckets";
144 if (sb->nbuckets > LONG_MAX)
145 goto err;
146
147 err = "Not enough buckets";
148 if (sb->nbuckets < 1 << 7)
149 goto err;
150
151 err = "Bad block/bucket size";
152 if (!is_power_of_2(sb->block_size) ||
153 sb->block_size > PAGE_SECTORS ||
154 !is_power_of_2(sb->bucket_size) ||
155 sb->bucket_size < PAGE_SECTORS)
156 goto err;
157
158 err = "Invalid superblock: device too small";
159 if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
160 goto err;
161
162 err = "Bad UUID";
163 if (bch_is_zero(sb->set_uuid, 16))
164 goto err;
165
166 err = "Bad cache device number in set";
167 if (!sb->nr_in_set ||
168 sb->nr_in_set <= sb->nr_this_dev ||
169 sb->nr_in_set > MAX_CACHES_PER_SET)
170 goto err;
171
172 err = "Journal buckets not sequential";
173 for (i = 0; i < sb->keys; i++)
174 if (sb->d[i] != sb->first_bucket + i)
175 goto err;
176
177 err = "Too many journal buckets";
178 if (sb->first_bucket + sb->keys > sb->nbuckets)
179 goto err;
180
181 err = "Invalid superblock: first bucket comes before end of super";
182 if (sb->first_bucket * sb->bucket_size < 16)
183 goto err;
184
185 break;
186 default:
187 err = "Unsupported superblock version";
188 goto err;
189 }
190
191 sb->last_mount = get_seconds();
192 err = NULL;
193
194 get_page(bh->b_page);
195 *res = bh->b_page;
196 err:
197 put_bh(bh);
198 return err;
199 }
200
201 static void write_bdev_super_endio(struct bio *bio)
202 {
203 struct cached_dev *dc = bio->bi_private;
204 /* XXX: error checking */
205
206 closure_put(&dc->sb_write);
207 }
208
209 static void __write_super(struct cache_sb *sb, struct bio *bio)
210 {
211 struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
212 unsigned i;
213
214 bio->bi_iter.bi_sector = SB_SECTOR;
215 bio->bi_iter.bi_size = SB_SIZE;
216 bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_SYNC|REQ_META);
217 bch_bio_map(bio, NULL);
218
219 out->offset = cpu_to_le64(sb->offset);
220 out->version = cpu_to_le64(sb->version);
221
222 memcpy(out->uuid, sb->uuid, 16);
223 memcpy(out->set_uuid, sb->set_uuid, 16);
224 memcpy(out->label, sb->label, SB_LABEL_SIZE);
225
226 out->flags = cpu_to_le64(sb->flags);
227 out->seq = cpu_to_le64(sb->seq);
228
229 out->last_mount = cpu_to_le32(sb->last_mount);
230 out->first_bucket = cpu_to_le16(sb->first_bucket);
231 out->keys = cpu_to_le16(sb->keys);
232
233 for (i = 0; i < sb->keys; i++)
234 out->d[i] = cpu_to_le64(sb->d[i]);
235
236 out->csum = csum_set(out);
237
238 pr_debug("ver %llu, flags %llu, seq %llu",
239 sb->version, sb->flags, sb->seq);
240
241 submit_bio(bio);
242 }
243
244 static void bch_write_bdev_super_unlock(struct closure *cl)
245 {
246 struct cached_dev *dc = container_of(cl, struct cached_dev, sb_write);
247
248 up(&dc->sb_write_mutex);
249 }
250
251 void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
252 {
253 struct closure *cl = &dc->sb_write;
254 struct bio *bio = &dc->sb_bio;
255
256 down(&dc->sb_write_mutex);
257 closure_init(cl, parent);
258
259 bio_reset(bio);
260 bio->bi_bdev = dc->bdev;
261 bio->bi_end_io = write_bdev_super_endio;
262 bio->bi_private = dc;
263
264 closure_get(cl);
265 __write_super(&dc->sb, bio);
266
267 closure_return_with_destructor(cl, bch_write_bdev_super_unlock);
268 }
269
270 static void write_super_endio(struct bio *bio)
271 {
272 struct cache *ca = bio->bi_private;
273
274 bch_count_io_errors(ca, bio->bi_error, "writing superblock");
275 closure_put(&ca->set->sb_write);
276 }
277
278 static void bcache_write_super_unlock(struct closure *cl)
279 {
280 struct cache_set *c = container_of(cl, struct cache_set, sb_write);
281
282 up(&c->sb_write_mutex);
283 }
284
285 void bcache_write_super(struct cache_set *c)
286 {
287 struct closure *cl = &c->sb_write;
288 struct cache *ca;
289 unsigned i;
290
291 down(&c->sb_write_mutex);
292 closure_init(cl, &c->cl);
293
294 c->sb.seq++;
295
296 for_each_cache(ca, c, i) {
297 struct bio *bio = &ca->sb_bio;
298
299 ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
300 ca->sb.seq = c->sb.seq;
301 ca->sb.last_mount = c->sb.last_mount;
302
303 SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb));
304
305 bio_reset(bio);
306 bio->bi_bdev = ca->bdev;
307 bio->bi_end_io = write_super_endio;
308 bio->bi_private = ca;
309
310 closure_get(cl);
311 __write_super(&ca->sb, bio);
312 }
313
314 closure_return_with_destructor(cl, bcache_write_super_unlock);
315 }
316
317 /* UUID io */
318
319 static void uuid_endio(struct bio *bio)
320 {
321 struct closure *cl = bio->bi_private;
322 struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
323
324 cache_set_err_on(bio->bi_error, c, "accessing uuids");
325 bch_bbio_free(bio, c);
326 closure_put(cl);
327 }
328
329 static void uuid_io_unlock(struct closure *cl)
330 {
331 struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
332
333 up(&c->uuid_write_mutex);
334 }
335
336 static void uuid_io(struct cache_set *c, int op, unsigned long op_flags,
337 struct bkey *k, struct closure *parent)
338 {
339 struct closure *cl = &c->uuid_write;
340 struct uuid_entry *u;
341 unsigned i;
342 char buf[80];
343
344 BUG_ON(!parent);
345 down(&c->uuid_write_mutex);
346 closure_init(cl, parent);
347
348 for (i = 0; i < KEY_PTRS(k); i++) {
349 struct bio *bio = bch_bbio_alloc(c);
350
351 bio->bi_opf = REQ_SYNC | REQ_META | op_flags;
352 bio->bi_iter.bi_size = KEY_SIZE(k) << 9;
353
354 bio->bi_end_io = uuid_endio;
355 bio->bi_private = cl;
356 bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags);
357 bch_bio_map(bio, c->uuids);
358
359 bch_submit_bbio(bio, c, k, i);
360
361 if (op != REQ_OP_WRITE)
362 break;
363 }
364
365 bch_extent_to_text(buf, sizeof(buf), k);
366 pr_debug("%s UUIDs at %s", op == REQ_OP_WRITE ? "wrote" : "read", buf);
367
368 for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
369 if (!bch_is_zero(u->uuid, 16))
370 pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
371 u - c->uuids, u->uuid, u->label,
372 u->first_reg, u->last_reg, u->invalidated);
373
374 closure_return_with_destructor(cl, uuid_io_unlock);
375 }
376
377 static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
378 {
379 struct bkey *k = &j->uuid_bucket;
380
381 if (__bch_btree_ptr_invalid(c, k))
382 return "bad uuid pointer";
383
384 bkey_copy(&c->uuid_bucket, k);
385 uuid_io(c, REQ_OP_READ, 0, k, cl);
386
387 if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
388 struct uuid_entry_v0 *u0 = (void *) c->uuids;
389 struct uuid_entry *u1 = (void *) c->uuids;
390 int i;
391
392 closure_sync(cl);
393
394 /*
395 * Since the new uuid entry is bigger than the old, we have to
396 * convert starting at the highest memory address and work down
397 * in order to do it in place
398 */
399
400 for (i = c->nr_uuids - 1;
401 i >= 0;
402 --i) {
403 memcpy(u1[i].uuid, u0[i].uuid, 16);
404 memcpy(u1[i].label, u0[i].label, 32);
405
406 u1[i].first_reg = u0[i].first_reg;
407 u1[i].last_reg = u0[i].last_reg;
408 u1[i].invalidated = u0[i].invalidated;
409
410 u1[i].flags = 0;
411 u1[i].sectors = 0;
412 }
413 }
414
415 return NULL;
416 }
417
418 static int __uuid_write(struct cache_set *c)
419 {
420 BKEY_PADDED(key) k;
421 struct closure cl;
422 closure_init_stack(&cl);
423
424 lockdep_assert_held(&bch_register_lock);
425
426 if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true))
427 return 1;
428
429 SET_KEY_SIZE(&k.key, c->sb.bucket_size);
430 uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl);
431 closure_sync(&cl);
432
433 bkey_copy(&c->uuid_bucket, &k.key);
434 bkey_put(c, &k.key);
435 return 0;
436 }
437
438 int bch_uuid_write(struct cache_set *c)
439 {
440 int ret = __uuid_write(c);
441
442 if (!ret)
443 bch_journal_meta(c, NULL);
444
445 return ret;
446 }
447
448 static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
449 {
450 struct uuid_entry *u;
451
452 for (u = c->uuids;
453 u < c->uuids + c->nr_uuids; u++)
454 if (!memcmp(u->uuid, uuid, 16))
455 return u;
456
457 return NULL;
458 }
459
460 static struct uuid_entry *uuid_find_empty(struct cache_set *c)
461 {
462 static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
463 return uuid_find(c, zero_uuid);
464 }
465
466 /*
467 * Bucket priorities/gens:
468 *
469 * For each bucket, we store on disk its
470 * 8 bit gen
471 * 16 bit priority
472 *
473 * See alloc.c for an explanation of the gen. The priority is used to implement
474 * lru (and in the future other) cache replacement policies; for most purposes
475 * it's just an opaque integer.
476 *
477 * The gens and the priorities don't have a whole lot to do with each other, and
478 * it's actually the gens that must be written out at specific times - it's no
479 * big deal if the priorities don't get written, if we lose them we just reuse
480 * buckets in suboptimal order.
481 *
482 * On disk they're stored in a packed array, and in as many buckets are required
483 * to fit them all. The buckets we use to store them form a list; the journal
484 * header points to the first bucket, the first bucket points to the second
485 * bucket, et cetera.
486 *
487 * This code is used by the allocation code; periodically (whenever it runs out
488 * of buckets to allocate from) the allocation code will invalidate some
489 * buckets, but it can't use those buckets until their new gens are safely on
490 * disk.
491 */
492
493 static void prio_endio(struct bio *bio)
494 {
495 struct cache *ca = bio->bi_private;
496
497 cache_set_err_on(bio->bi_error, ca->set, "accessing priorities");
498 bch_bbio_free(bio, ca->set);
499 closure_put(&ca->prio);
500 }
501
502 static void prio_io(struct cache *ca, uint64_t bucket, int op,
503 unsigned long op_flags)
504 {
505 struct closure *cl = &ca->prio;
506 struct bio *bio = bch_bbio_alloc(ca->set);
507
508 closure_init_stack(cl);
509
510 bio->bi_iter.bi_sector = bucket * ca->sb.bucket_size;
511 bio->bi_bdev = ca->bdev;
512 bio->bi_iter.bi_size = bucket_bytes(ca);
513
514 bio->bi_end_io = prio_endio;
515 bio->bi_private = ca;
516 bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags);
517 bch_bio_map(bio, ca->disk_buckets);
518
519 closure_bio_submit(bio, &ca->prio);
520 closure_sync(cl);
521 }
522
523 void bch_prio_write(struct cache *ca)
524 {
525 int i;
526 struct bucket *b;
527 struct closure cl;
528
529 closure_init_stack(&cl);
530
531 lockdep_assert_held(&ca->set->bucket_lock);
532
533 ca->disk_buckets->seq++;
534
535 atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
536 &ca->meta_sectors_written);
537
538 //pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free),
539 // fifo_used(&ca->free_inc), fifo_used(&ca->unused));
540
541 for (i = prio_buckets(ca) - 1; i >= 0; --i) {
542 long bucket;
543 struct prio_set *p = ca->disk_buckets;
544 struct bucket_disk *d = p->data;
545 struct bucket_disk *end = d + prios_per_bucket(ca);
546
547 for (b = ca->buckets + i * prios_per_bucket(ca);
548 b < ca->buckets + ca->sb.nbuckets && d < end;
549 b++, d++) {
550 d->prio = cpu_to_le16(b->prio);
551 d->gen = b->gen;
552 }
553
554 p->next_bucket = ca->prio_buckets[i + 1];
555 p->magic = pset_magic(&ca->sb);
556 p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8);
557
558 bucket = bch_bucket_alloc(ca, RESERVE_PRIO, true);
559 BUG_ON(bucket == -1);
560
561 mutex_unlock(&ca->set->bucket_lock);
562 prio_io(ca, bucket, REQ_OP_WRITE, 0);
563 mutex_lock(&ca->set->bucket_lock);
564
565 ca->prio_buckets[i] = bucket;
566 atomic_dec_bug(&ca->buckets[bucket].pin);
567 }
568
569 mutex_unlock(&ca->set->bucket_lock);
570
571 bch_journal_meta(ca->set, &cl);
572 closure_sync(&cl);
573
574 mutex_lock(&ca->set->bucket_lock);
575
576 /*
577 * Don't want the old priorities to get garbage collected until after we
578 * finish writing the new ones, and they're journalled
579 */
580 for (i = 0; i < prio_buckets(ca); i++) {
581 if (ca->prio_last_buckets[i])
582 __bch_bucket_free(ca,
583 &ca->buckets[ca->prio_last_buckets[i]]);
584
585 ca->prio_last_buckets[i] = ca->prio_buckets[i];
586 }
587 }
588
589 static void prio_read(struct cache *ca, uint64_t bucket)
590 {
591 struct prio_set *p = ca->disk_buckets;
592 struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
593 struct bucket *b;
594 unsigned bucket_nr = 0;
595
596 for (b = ca->buckets;
597 b < ca->buckets + ca->sb.nbuckets;
598 b++, d++) {
599 if (d == end) {
600 ca->prio_buckets[bucket_nr] = bucket;
601 ca->prio_last_buckets[bucket_nr] = bucket;
602 bucket_nr++;
603
604 prio_io(ca, bucket, REQ_OP_READ, 0);
605
606 if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8))
607 pr_warn("bad csum reading priorities");
608
609 if (p->magic != pset_magic(&ca->sb))
610 pr_warn("bad magic reading priorities");
611
612 bucket = p->next_bucket;
613 d = p->data;
614 }
615
616 b->prio = le16_to_cpu(d->prio);
617 b->gen = b->last_gc = d->gen;
618 }
619 }
620
621 /* Bcache device */
622
623 static int open_dev(struct block_device *b, fmode_t mode)
624 {
625 struct bcache_device *d = b->bd_disk->private_data;
626 if (test_bit(BCACHE_DEV_CLOSING, &d->flags))
627 return -ENXIO;
628
629 closure_get(&d->cl);
630 return 0;
631 }
632
633 static void release_dev(struct gendisk *b, fmode_t mode)
634 {
635 struct bcache_device *d = b->private_data;
636 closure_put(&d->cl);
637 }
638
639 static int ioctl_dev(struct block_device *b, fmode_t mode,
640 unsigned int cmd, unsigned long arg)
641 {
642 struct bcache_device *d = b->bd_disk->private_data;
643 return d->ioctl(d, mode, cmd, arg);
644 }
645
646 static const struct block_device_operations bcache_ops = {
647 .open = open_dev,
648 .release = release_dev,
649 .ioctl = ioctl_dev,
650 .owner = THIS_MODULE,
651 };
652
653 void bcache_device_stop(struct bcache_device *d)
654 {
655 if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags))
656 closure_queue(&d->cl);
657 }
658
659 static void bcache_device_unlink(struct bcache_device *d)
660 {
661 lockdep_assert_held(&bch_register_lock);
662
663 if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) {
664 unsigned i;
665 struct cache *ca;
666
667 sysfs_remove_link(&d->c->kobj, d->name);
668 sysfs_remove_link(&d->kobj, "cache");
669
670 for_each_cache(ca, d->c, i)
671 bd_unlink_disk_holder(ca->bdev, d->disk);
672 }
673 }
674
675 static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
676 const char *name)
677 {
678 unsigned i;
679 struct cache *ca;
680
681 for_each_cache(ca, d->c, i)
682 bd_link_disk_holder(ca->bdev, d->disk);
683
684 snprintf(d->name, BCACHEDEVNAME_SIZE,
685 "%s%u", name, d->id);
686
687 WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
688 sysfs_create_link(&c->kobj, &d->kobj, d->name),
689 "Couldn't create device <-> cache set symlinks");
690
691 clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
692 }
693
694 static void bcache_device_detach(struct bcache_device *d)
695 {
696 lockdep_assert_held(&bch_register_lock);
697
698 if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) {
699 struct uuid_entry *u = d->c->uuids + d->id;
700
701 SET_UUID_FLASH_ONLY(u, 0);
702 memcpy(u->uuid, invalid_uuid, 16);
703 u->invalidated = cpu_to_le32(get_seconds());
704 bch_uuid_write(d->c);
705 }
706
707 bcache_device_unlink(d);
708
709 d->c->devices[d->id] = NULL;
710 closure_put(&d->c->caching);
711 d->c = NULL;
712 }
713
714 static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
715 unsigned id)
716 {
717 d->id = id;
718 d->c = c;
719 c->devices[id] = d;
720
721 closure_get(&c->caching);
722 }
723
724 static void bcache_device_free(struct bcache_device *d)
725 {
726 lockdep_assert_held(&bch_register_lock);
727
728 pr_info("%s stopped", d->disk->disk_name);
729
730 if (d->c)
731 bcache_device_detach(d);
732 if (d->disk && d->disk->flags & GENHD_FL_UP)
733 del_gendisk(d->disk);
734 if (d->disk && d->disk->queue)
735 blk_cleanup_queue(d->disk->queue);
736 if (d->disk) {
737 ida_simple_remove(&bcache_minor, d->disk->first_minor);
738 put_disk(d->disk);
739 }
740
741 if (d->bio_split)
742 bioset_free(d->bio_split);
743 kvfree(d->full_dirty_stripes);
744 kvfree(d->stripe_sectors_dirty);
745
746 closure_debug_destroy(&d->cl);
747 }
748
749 static int bcache_device_init(struct bcache_device *d, unsigned block_size,
750 sector_t sectors)
751 {
752 struct request_queue *q;
753 size_t n;
754 int minor;
755
756 if (!d->stripe_size)
757 d->stripe_size = 1 << 31;
758
759 d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
760
761 if (!d->nr_stripes ||
762 d->nr_stripes > INT_MAX ||
763 d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
764 pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)",
765 (unsigned)d->nr_stripes);
766 return -ENOMEM;
767 }
768
769 n = d->nr_stripes * sizeof(atomic_t);
770 d->stripe_sectors_dirty = n < PAGE_SIZE << 6
771 ? kzalloc(n, GFP_KERNEL)
772 : vzalloc(n);
773 if (!d->stripe_sectors_dirty)
774 return -ENOMEM;
775
776 n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long);
777 d->full_dirty_stripes = n < PAGE_SIZE << 6
778 ? kzalloc(n, GFP_KERNEL)
779 : vzalloc(n);
780 if (!d->full_dirty_stripes)
781 return -ENOMEM;
782
783 minor = ida_simple_get(&bcache_minor, 0, MINORMASK + 1, GFP_KERNEL);
784 if (minor < 0)
785 return minor;
786
787 minor *= BCACHE_MINORS;
788
789 if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
790 !(d->disk = alloc_disk(BCACHE_MINORS))) {
791 ida_simple_remove(&bcache_minor, minor);
792 return -ENOMEM;
793 }
794
795 set_capacity(d->disk, sectors);
796 snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", minor);
797
798 d->disk->major = bcache_major;
799 d->disk->first_minor = minor;
800 d->disk->fops = &bcache_ops;
801 d->disk->private_data = d;
802
803 q = blk_alloc_queue(GFP_KERNEL);
804 if (!q)
805 return -ENOMEM;
806
807 blk_queue_make_request(q, NULL);
808 d->disk->queue = q;
809 q->queuedata = d;
810 q->backing_dev_info.congested_data = d;
811 q->limits.max_hw_sectors = UINT_MAX;
812 q->limits.max_sectors = UINT_MAX;
813 q->limits.max_segment_size = UINT_MAX;
814 q->limits.max_segments = BIO_MAX_PAGES;
815 blk_queue_max_discard_sectors(q, UINT_MAX);
816 q->limits.discard_granularity = 512;
817 q->limits.io_min = block_size;
818 q->limits.logical_block_size = block_size;
819 q->limits.physical_block_size = block_size;
820 set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags);
821 clear_bit(QUEUE_FLAG_ADD_RANDOM, &d->disk->queue->queue_flags);
822 set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags);
823
824 blk_queue_write_cache(q, true, true);
825
826 return 0;
827 }
828
829 /* Cached device */
830
831 static void calc_cached_dev_sectors(struct cache_set *c)
832 {
833 uint64_t sectors = 0;
834 struct cached_dev *dc;
835
836 list_for_each_entry(dc, &c->cached_devs, list)
837 sectors += bdev_sectors(dc->bdev);
838
839 c->cached_dev_sectors = sectors;
840 }
841
842 void bch_cached_dev_run(struct cached_dev *dc)
843 {
844 struct bcache_device *d = &dc->disk;
845 char buf[SB_LABEL_SIZE + 1];
846 char *env[] = {
847 "DRIVER=bcache",
848 kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid),
849 NULL,
850 NULL,
851 };
852
853 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
854 buf[SB_LABEL_SIZE] = '\0';
855 env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf);
856
857 if (atomic_xchg(&dc->running, 1)) {
858 kfree(env[1]);
859 kfree(env[2]);
860 return;
861 }
862
863 if (!d->c &&
864 BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
865 struct closure cl;
866 closure_init_stack(&cl);
867
868 SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
869 bch_write_bdev_super(dc, &cl);
870 closure_sync(&cl);
871 }
872
873 add_disk(d->disk);
874 bd_link_disk_holder(dc->bdev, dc->disk.disk);
875 /* won't show up in the uevent file, use udevadm monitor -e instead
876 * only class / kset properties are persistent */
877 kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
878 kfree(env[1]);
879 kfree(env[2]);
880
881 if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
882 sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache"))
883 pr_debug("error creating sysfs link");
884 }
885
886 static void cached_dev_detach_finish(struct work_struct *w)
887 {
888 struct cached_dev *dc = container_of(w, struct cached_dev, detach);
889 char buf[BDEVNAME_SIZE];
890 struct closure cl;
891 closure_init_stack(&cl);
892
893 BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags));
894 BUG_ON(atomic_read(&dc->count));
895
896 mutex_lock(&bch_register_lock);
897
898 memset(&dc->sb.set_uuid, 0, 16);
899 SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
900
901 bch_write_bdev_super(dc, &cl);
902 closure_sync(&cl);
903
904 bcache_device_detach(&dc->disk);
905 list_move(&dc->list, &uncached_devices);
906
907 clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags);
908 clear_bit(BCACHE_DEV_UNLINK_DONE, &dc->disk.flags);
909
910 mutex_unlock(&bch_register_lock);
911
912 pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
913
914 /* Drop ref we took in cached_dev_detach() */
915 closure_put(&dc->disk.cl);
916 }
917
918 void bch_cached_dev_detach(struct cached_dev *dc)
919 {
920 lockdep_assert_held(&bch_register_lock);
921
922 if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
923 return;
924
925 if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
926 return;
927
928 /*
929 * Block the device from being closed and freed until we're finished
930 * detaching
931 */
932 closure_get(&dc->disk.cl);
933
934 bch_writeback_queue(dc);
935 cached_dev_put(dc);
936 }
937
938 int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c)
939 {
940 uint32_t rtime = cpu_to_le32(get_seconds());
941 struct uuid_entry *u;
942 char buf[BDEVNAME_SIZE];
943
944 bdevname(dc->bdev, buf);
945
946 if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16))
947 return -ENOENT;
948
949 if (dc->disk.c) {
950 pr_err("Can't attach %s: already attached", buf);
951 return -EINVAL;
952 }
953
954 if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
955 pr_err("Can't attach %s: shutting down", buf);
956 return -EINVAL;
957 }
958
959 if (dc->sb.block_size < c->sb.block_size) {
960 /* Will die */
961 pr_err("Couldn't attach %s: block size less than set's block size",
962 buf);
963 return -EINVAL;
964 }
965
966 u = uuid_find(c, dc->sb.uuid);
967
968 if (u &&
969 (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
970 BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
971 memcpy(u->uuid, invalid_uuid, 16);
972 u->invalidated = cpu_to_le32(get_seconds());
973 u = NULL;
974 }
975
976 if (!u) {
977 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
978 pr_err("Couldn't find uuid for %s in set", buf);
979 return -ENOENT;
980 }
981
982 u = uuid_find_empty(c);
983 if (!u) {
984 pr_err("Not caching %s, no room for UUID", buf);
985 return -EINVAL;
986 }
987 }
988
989 /* Deadlocks since we're called via sysfs...
990 sysfs_remove_file(&dc->kobj, &sysfs_attach);
991 */
992
993 if (bch_is_zero(u->uuid, 16)) {
994 struct closure cl;
995 closure_init_stack(&cl);
996
997 memcpy(u->uuid, dc->sb.uuid, 16);
998 memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
999 u->first_reg = u->last_reg = rtime;
1000 bch_uuid_write(c);
1001
1002 memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
1003 SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
1004
1005 bch_write_bdev_super(dc, &cl);
1006 closure_sync(&cl);
1007 } else {
1008 u->last_reg = rtime;
1009 bch_uuid_write(c);
1010 }
1011
1012 bcache_device_attach(&dc->disk, c, u - c->uuids);
1013 list_move(&dc->list, &c->cached_devs);
1014 calc_cached_dev_sectors(c);
1015
1016 smp_wmb();
1017 /*
1018 * dc->c must be set before dc->count != 0 - paired with the mb in
1019 * cached_dev_get()
1020 */
1021 atomic_set(&dc->count, 1);
1022
1023 /* Block writeback thread, but spawn it */
1024 down_write(&dc->writeback_lock);
1025 if (bch_cached_dev_writeback_start(dc)) {
1026 up_write(&dc->writeback_lock);
1027 return -ENOMEM;
1028 }
1029
1030 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
1031 bch_sectors_dirty_init(dc);
1032 atomic_set(&dc->has_dirty, 1);
1033 atomic_inc(&dc->count);
1034 bch_writeback_queue(dc);
1035 }
1036
1037 bch_cached_dev_run(dc);
1038 bcache_device_link(&dc->disk, c, "bdev");
1039
1040 /* Allow the writeback thread to proceed */
1041 up_write(&dc->writeback_lock);
1042
1043 pr_info("Caching %s as %s on set %pU",
1044 bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
1045 dc->disk.c->sb.set_uuid);
1046 return 0;
1047 }
1048
1049 void bch_cached_dev_release(struct kobject *kobj)
1050 {
1051 struct cached_dev *dc = container_of(kobj, struct cached_dev,
1052 disk.kobj);
1053 kfree(dc);
1054 module_put(THIS_MODULE);
1055 }
1056
1057 static void cached_dev_free(struct closure *cl)
1058 {
1059 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1060
1061 cancel_delayed_work_sync(&dc->writeback_rate_update);
1062 if (!IS_ERR_OR_NULL(dc->writeback_thread))
1063 kthread_stop(dc->writeback_thread);
1064
1065 mutex_lock(&bch_register_lock);
1066
1067 if (atomic_read(&dc->running))
1068 bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
1069 bcache_device_free(&dc->disk);
1070 list_del(&dc->list);
1071
1072 mutex_unlock(&bch_register_lock);
1073
1074 if (!IS_ERR_OR_NULL(dc->bdev))
1075 blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1076
1077 wake_up(&unregister_wait);
1078
1079 kobject_put(&dc->disk.kobj);
1080 }
1081
1082 static void cached_dev_flush(struct closure *cl)
1083 {
1084 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1085 struct bcache_device *d = &dc->disk;
1086
1087 mutex_lock(&bch_register_lock);
1088 bcache_device_unlink(d);
1089 mutex_unlock(&bch_register_lock);
1090
1091 bch_cache_accounting_destroy(&dc->accounting);
1092 kobject_del(&d->kobj);
1093
1094 continue_at(cl, cached_dev_free, system_wq);
1095 }
1096
1097 static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
1098 {
1099 int ret;
1100 struct io *io;
1101 struct request_queue *q = bdev_get_queue(dc->bdev);
1102
1103 __module_get(THIS_MODULE);
1104 INIT_LIST_HEAD(&dc->list);
1105 closure_init(&dc->disk.cl, NULL);
1106 set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
1107 kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
1108 INIT_WORK(&dc->detach, cached_dev_detach_finish);
1109 sema_init(&dc->sb_write_mutex, 1);
1110 INIT_LIST_HEAD(&dc->io_lru);
1111 spin_lock_init(&dc->io_lock);
1112 bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
1113
1114 dc->sequential_cutoff = 4 << 20;
1115
1116 for (io = dc->io; io < dc->io + RECENT_IO; io++) {
1117 list_add(&io->lru, &dc->io_lru);
1118 hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
1119 }
1120
1121 dc->disk.stripe_size = q->limits.io_opt >> 9;
1122
1123 if (dc->disk.stripe_size)
1124 dc->partial_stripes_expensive =
1125 q->limits.raid_partial_stripes_expensive;
1126
1127 ret = bcache_device_init(&dc->disk, block_size,
1128 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1129 if (ret)
1130 return ret;
1131
1132 set_capacity(dc->disk.disk,
1133 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1134
1135 dc->disk.disk->queue->backing_dev_info.ra_pages =
1136 max(dc->disk.disk->queue->backing_dev_info.ra_pages,
1137 q->backing_dev_info.ra_pages);
1138
1139 bch_cached_dev_request_init(dc);
1140 bch_cached_dev_writeback_init(dc);
1141 return 0;
1142 }
1143
1144 /* Cached device - bcache superblock */
1145
1146 static void register_bdev(struct cache_sb *sb, struct page *sb_page,
1147 struct block_device *bdev,
1148 struct cached_dev *dc)
1149 {
1150 char name[BDEVNAME_SIZE];
1151 const char *err = "cannot allocate memory";
1152 struct cache_set *c;
1153
1154 memcpy(&dc->sb, sb, sizeof(struct cache_sb));
1155 dc->bdev = bdev;
1156 dc->bdev->bd_holder = dc;
1157
1158 bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1);
1159 dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
1160 get_page(sb_page);
1161
1162 if (cached_dev_init(dc, sb->block_size << 9))
1163 goto err;
1164
1165 err = "error creating kobject";
1166 if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
1167 "bcache"))
1168 goto err;
1169 if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
1170 goto err;
1171
1172 pr_info("registered backing device %s", bdevname(bdev, name));
1173
1174 list_add(&dc->list, &uncached_devices);
1175 list_for_each_entry(c, &bch_cache_sets, list)
1176 bch_cached_dev_attach(dc, c);
1177
1178 if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
1179 BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
1180 bch_cached_dev_run(dc);
1181
1182 return;
1183 err:
1184 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1185 bcache_device_stop(&dc->disk);
1186 }
1187
1188 /* Flash only volumes */
1189
1190 void bch_flash_dev_release(struct kobject *kobj)
1191 {
1192 struct bcache_device *d = container_of(kobj, struct bcache_device,
1193 kobj);
1194 kfree(d);
1195 }
1196
1197 static void flash_dev_free(struct closure *cl)
1198 {
1199 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1200 mutex_lock(&bch_register_lock);
1201 bcache_device_free(d);
1202 mutex_unlock(&bch_register_lock);
1203 kobject_put(&d->kobj);
1204 }
1205
1206 static void flash_dev_flush(struct closure *cl)
1207 {
1208 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1209
1210 mutex_lock(&bch_register_lock);
1211 bcache_device_unlink(d);
1212 mutex_unlock(&bch_register_lock);
1213 kobject_del(&d->kobj);
1214 continue_at(cl, flash_dev_free, system_wq);
1215 }
1216
1217 static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
1218 {
1219 struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
1220 GFP_KERNEL);
1221 if (!d)
1222 return -ENOMEM;
1223
1224 closure_init(&d->cl, NULL);
1225 set_closure_fn(&d->cl, flash_dev_flush, system_wq);
1226
1227 kobject_init(&d->kobj, &bch_flash_dev_ktype);
1228
1229 if (bcache_device_init(d, block_bytes(c), u->sectors))
1230 goto err;
1231
1232 bcache_device_attach(d, c, u - c->uuids);
1233 bch_flash_dev_request_init(d);
1234 add_disk(d->disk);
1235
1236 if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache"))
1237 goto err;
1238
1239 bcache_device_link(d, c, "volume");
1240
1241 return 0;
1242 err:
1243 kobject_put(&d->kobj);
1244 return -ENOMEM;
1245 }
1246
1247 static int flash_devs_run(struct cache_set *c)
1248 {
1249 int ret = 0;
1250 struct uuid_entry *u;
1251
1252 for (u = c->uuids;
1253 u < c->uuids + c->nr_uuids && !ret;
1254 u++)
1255 if (UUID_FLASH_ONLY(u))
1256 ret = flash_dev_run(c, u);
1257
1258 return ret;
1259 }
1260
1261 int bch_flash_dev_create(struct cache_set *c, uint64_t size)
1262 {
1263 struct uuid_entry *u;
1264
1265 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1266 return -EINTR;
1267
1268 if (!test_bit(CACHE_SET_RUNNING, &c->flags))
1269 return -EPERM;
1270
1271 u = uuid_find_empty(c);
1272 if (!u) {
1273 pr_err("Can't create volume, no room for UUID");
1274 return -EINVAL;
1275 }
1276
1277 get_random_bytes(u->uuid, 16);
1278 memset(u->label, 0, 32);
1279 u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
1280
1281 SET_UUID_FLASH_ONLY(u, 1);
1282 u->sectors = size >> 9;
1283
1284 bch_uuid_write(c);
1285
1286 return flash_dev_run(c, u);
1287 }
1288
1289 /* Cache set */
1290
1291 __printf(2, 3)
1292 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
1293 {
1294 va_list args;
1295
1296 if (c->on_error != ON_ERROR_PANIC &&
1297 test_bit(CACHE_SET_STOPPING, &c->flags))
1298 return false;
1299
1300 /* XXX: we can be called from atomic context
1301 acquire_console_sem();
1302 */
1303
1304 printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid);
1305
1306 va_start(args, fmt);
1307 vprintk(fmt, args);
1308 va_end(args);
1309
1310 printk(", disabling caching\n");
1311
1312 if (c->on_error == ON_ERROR_PANIC)
1313 panic("panic forced after error\n");
1314
1315 bch_cache_set_unregister(c);
1316 return true;
1317 }
1318
1319 void bch_cache_set_release(struct kobject *kobj)
1320 {
1321 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
1322 kfree(c);
1323 module_put(THIS_MODULE);
1324 }
1325
1326 static void cache_set_free(struct closure *cl)
1327 {
1328 struct cache_set *c = container_of(cl, struct cache_set, cl);
1329 struct cache *ca;
1330 unsigned i;
1331
1332 if (!IS_ERR_OR_NULL(c->debug))
1333 debugfs_remove(c->debug);
1334
1335 bch_open_buckets_free(c);
1336 bch_btree_cache_free(c);
1337 bch_journal_free(c);
1338
1339 for_each_cache(ca, c, i)
1340 if (ca) {
1341 ca->set = NULL;
1342 c->cache[ca->sb.nr_this_dev] = NULL;
1343 kobject_put(&ca->kobj);
1344 }
1345
1346 bch_bset_sort_state_free(&c->sort);
1347 free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
1348
1349 if (c->moving_gc_wq)
1350 destroy_workqueue(c->moving_gc_wq);
1351 if (c->bio_split)
1352 bioset_free(c->bio_split);
1353 if (c->fill_iter)
1354 mempool_destroy(c->fill_iter);
1355 if (c->bio_meta)
1356 mempool_destroy(c->bio_meta);
1357 if (c->search)
1358 mempool_destroy(c->search);
1359 kfree(c->devices);
1360
1361 mutex_lock(&bch_register_lock);
1362 list_del(&c->list);
1363 mutex_unlock(&bch_register_lock);
1364
1365 pr_info("Cache set %pU unregistered", c->sb.set_uuid);
1366 wake_up(&unregister_wait);
1367
1368 closure_debug_destroy(&c->cl);
1369 kobject_put(&c->kobj);
1370 }
1371
1372 static void cache_set_flush(struct closure *cl)
1373 {
1374 struct cache_set *c = container_of(cl, struct cache_set, caching);
1375 struct cache *ca;
1376 struct btree *b;
1377 unsigned i;
1378
1379 if (!c)
1380 closure_return(cl);
1381
1382 bch_cache_accounting_destroy(&c->accounting);
1383
1384 kobject_put(&c->internal);
1385 kobject_del(&c->kobj);
1386
1387 if (c->gc_thread)
1388 kthread_stop(c->gc_thread);
1389
1390 if (!IS_ERR_OR_NULL(c->root))
1391 list_add(&c->root->list, &c->btree_cache);
1392
1393 /* Should skip this if we're unregistering because of an error */
1394 list_for_each_entry(b, &c->btree_cache, list) {
1395 mutex_lock(&b->write_lock);
1396 if (btree_node_dirty(b))
1397 __bch_btree_node_write(b, NULL);
1398 mutex_unlock(&b->write_lock);
1399 }
1400
1401 for_each_cache(ca, c, i)
1402 if (ca->alloc_thread)
1403 kthread_stop(ca->alloc_thread);
1404
1405 if (c->journal.cur) {
1406 cancel_delayed_work_sync(&c->journal.work);
1407 /* flush last journal entry if needed */
1408 c->journal.work.work.func(&c->journal.work.work);
1409 }
1410
1411 closure_return(cl);
1412 }
1413
1414 static void __cache_set_unregister(struct closure *cl)
1415 {
1416 struct cache_set *c = container_of(cl, struct cache_set, caching);
1417 struct cached_dev *dc;
1418 size_t i;
1419
1420 mutex_lock(&bch_register_lock);
1421
1422 for (i = 0; i < c->nr_uuids; i++)
1423 if (c->devices[i]) {
1424 if (!UUID_FLASH_ONLY(&c->uuids[i]) &&
1425 test_bit(CACHE_SET_UNREGISTERING, &c->flags)) {
1426 dc = container_of(c->devices[i],
1427 struct cached_dev, disk);
1428 bch_cached_dev_detach(dc);
1429 } else {
1430 bcache_device_stop(c->devices[i]);
1431 }
1432 }
1433
1434 mutex_unlock(&bch_register_lock);
1435
1436 continue_at(cl, cache_set_flush, system_wq);
1437 }
1438
1439 void bch_cache_set_stop(struct cache_set *c)
1440 {
1441 if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
1442 closure_queue(&c->caching);
1443 }
1444
1445 void bch_cache_set_unregister(struct cache_set *c)
1446 {
1447 set_bit(CACHE_SET_UNREGISTERING, &c->flags);
1448 bch_cache_set_stop(c);
1449 }
1450
1451 #define alloc_bucket_pages(gfp, c) \
1452 ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c))))
1453
1454 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1455 {
1456 int iter_size;
1457 struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
1458 if (!c)
1459 return NULL;
1460
1461 __module_get(THIS_MODULE);
1462 closure_init(&c->cl, NULL);
1463 set_closure_fn(&c->cl, cache_set_free, system_wq);
1464
1465 closure_init(&c->caching, &c->cl);
1466 set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
1467
1468 /* Maybe create continue_at_noreturn() and use it here? */
1469 closure_set_stopped(&c->cl);
1470 closure_put(&c->cl);
1471
1472 kobject_init(&c->kobj, &bch_cache_set_ktype);
1473 kobject_init(&c->internal, &bch_cache_set_internal_ktype);
1474
1475 bch_cache_accounting_init(&c->accounting, &c->cl);
1476
1477 memcpy(c->sb.set_uuid, sb->set_uuid, 16);
1478 c->sb.block_size = sb->block_size;
1479 c->sb.bucket_size = sb->bucket_size;
1480 c->sb.nr_in_set = sb->nr_in_set;
1481 c->sb.last_mount = sb->last_mount;
1482 c->bucket_bits = ilog2(sb->bucket_size);
1483 c->block_bits = ilog2(sb->block_size);
1484 c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
1485
1486 c->btree_pages = bucket_pages(c);
1487 if (c->btree_pages > BTREE_MAX_PAGES)
1488 c->btree_pages = max_t(int, c->btree_pages / 4,
1489 BTREE_MAX_PAGES);
1490
1491 sema_init(&c->sb_write_mutex, 1);
1492 mutex_init(&c->bucket_lock);
1493 init_waitqueue_head(&c->btree_cache_wait);
1494 init_waitqueue_head(&c->bucket_wait);
1495 init_waitqueue_head(&c->gc_wait);
1496 sema_init(&c->uuid_write_mutex, 1);
1497
1498 spin_lock_init(&c->btree_gc_time.lock);
1499 spin_lock_init(&c->btree_split_time.lock);
1500 spin_lock_init(&c->btree_read_time.lock);
1501
1502 bch_moving_init_cache_set(c);
1503
1504 INIT_LIST_HEAD(&c->list);
1505 INIT_LIST_HEAD(&c->cached_devs);
1506 INIT_LIST_HEAD(&c->btree_cache);
1507 INIT_LIST_HEAD(&c->btree_cache_freeable);
1508 INIT_LIST_HEAD(&c->btree_cache_freed);
1509 INIT_LIST_HEAD(&c->data_buckets);
1510
1511 c->search = mempool_create_slab_pool(32, bch_search_cache);
1512 if (!c->search)
1513 goto err;
1514
1515 iter_size = (sb->bucket_size / sb->block_size + 1) *
1516 sizeof(struct btree_iter_set);
1517
1518 if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) ||
1519 !(c->bio_meta = mempool_create_kmalloc_pool(2,
1520 sizeof(struct bbio) + sizeof(struct bio_vec) *
1521 bucket_pages(c))) ||
1522 !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
1523 !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
1524 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1525 !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
1526 WQ_MEM_RECLAIM, 0)) ||
1527 bch_journal_alloc(c) ||
1528 bch_btree_cache_alloc(c) ||
1529 bch_open_buckets_alloc(c) ||
1530 bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
1531 goto err;
1532
1533 c->congested_read_threshold_us = 2000;
1534 c->congested_write_threshold_us = 20000;
1535 c->error_limit = 8 << IO_ERROR_SHIFT;
1536
1537 return c;
1538 err:
1539 bch_cache_set_unregister(c);
1540 return NULL;
1541 }
1542
1543 static void run_cache_set(struct cache_set *c)
1544 {
1545 const char *err = "cannot allocate memory";
1546 struct cached_dev *dc, *t;
1547 struct cache *ca;
1548 struct closure cl;
1549 unsigned i;
1550
1551 closure_init_stack(&cl);
1552
1553 for_each_cache(ca, c, i)
1554 c->nbuckets += ca->sb.nbuckets;
1555 set_gc_sectors(c);
1556
1557 if (CACHE_SYNC(&c->sb)) {
1558 LIST_HEAD(journal);
1559 struct bkey *k;
1560 struct jset *j;
1561
1562 err = "cannot allocate memory for journal";
1563 if (bch_journal_read(c, &journal))
1564 goto err;
1565
1566 pr_debug("btree_journal_read() done");
1567
1568 err = "no journal entries found";
1569 if (list_empty(&journal))
1570 goto err;
1571
1572 j = &list_entry(journal.prev, struct journal_replay, list)->j;
1573
1574 err = "IO error reading priorities";
1575 for_each_cache(ca, c, i)
1576 prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]);
1577
1578 /*
1579 * If prio_read() fails it'll call cache_set_error and we'll
1580 * tear everything down right away, but if we perhaps checked
1581 * sooner we could avoid journal replay.
1582 */
1583
1584 k = &j->btree_root;
1585
1586 err = "bad btree root";
1587 if (__bch_btree_ptr_invalid(c, k))
1588 goto err;
1589
1590 err = "error reading btree root";
1591 c->root = bch_btree_node_get(c, NULL, k, j->btree_level, true, NULL);
1592 if (IS_ERR_OR_NULL(c->root))
1593 goto err;
1594
1595 list_del_init(&c->root->list);
1596 rw_unlock(true, c->root);
1597
1598 err = uuid_read(c, j, &cl);
1599 if (err)
1600 goto err;
1601
1602 err = "error in recovery";
1603 if (bch_btree_check(c))
1604 goto err;
1605
1606 bch_journal_mark(c, &journal);
1607 bch_initial_gc_finish(c);
1608 pr_debug("btree_check() done");
1609
1610 /*
1611 * bcache_journal_next() can't happen sooner, or
1612 * btree_gc_finish() will give spurious errors about last_gc >
1613 * gc_gen - this is a hack but oh well.
1614 */
1615 bch_journal_next(&c->journal);
1616
1617 err = "error starting allocator thread";
1618 for_each_cache(ca, c, i)
1619 if (bch_cache_allocator_start(ca))
1620 goto err;
1621
1622 /*
1623 * First place it's safe to allocate: btree_check() and
1624 * btree_gc_finish() have to run before we have buckets to
1625 * allocate, and bch_bucket_alloc_set() might cause a journal
1626 * entry to be written so bcache_journal_next() has to be called
1627 * first.
1628 *
1629 * If the uuids were in the old format we have to rewrite them
1630 * before the next journal entry is written:
1631 */
1632 if (j->version < BCACHE_JSET_VERSION_UUID)
1633 __uuid_write(c);
1634
1635 bch_journal_replay(c, &journal);
1636 } else {
1637 pr_notice("invalidating existing data");
1638
1639 for_each_cache(ca, c, i) {
1640 unsigned j;
1641
1642 ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
1643 2, SB_JOURNAL_BUCKETS);
1644
1645 for (j = 0; j < ca->sb.keys; j++)
1646 ca->sb.d[j] = ca->sb.first_bucket + j;
1647 }
1648
1649 bch_initial_gc_finish(c);
1650
1651 err = "error starting allocator thread";
1652 for_each_cache(ca, c, i)
1653 if (bch_cache_allocator_start(ca))
1654 goto err;
1655
1656 mutex_lock(&c->bucket_lock);
1657 for_each_cache(ca, c, i)
1658 bch_prio_write(ca);
1659 mutex_unlock(&c->bucket_lock);
1660
1661 err = "cannot allocate new UUID bucket";
1662 if (__uuid_write(c))
1663 goto err;
1664
1665 err = "cannot allocate new btree root";
1666 c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL);
1667 if (IS_ERR_OR_NULL(c->root))
1668 goto err;
1669
1670 mutex_lock(&c->root->write_lock);
1671 bkey_copy_key(&c->root->key, &MAX_KEY);
1672 bch_btree_node_write(c->root, &cl);
1673 mutex_unlock(&c->root->write_lock);
1674
1675 bch_btree_set_root(c->root);
1676 rw_unlock(true, c->root);
1677
1678 /*
1679 * We don't want to write the first journal entry until
1680 * everything is set up - fortunately journal entries won't be
1681 * written until the SET_CACHE_SYNC() here:
1682 */
1683 SET_CACHE_SYNC(&c->sb, true);
1684
1685 bch_journal_next(&c->journal);
1686 bch_journal_meta(c, &cl);
1687 }
1688
1689 err = "error starting gc thread";
1690 if (bch_gc_thread_start(c))
1691 goto err;
1692
1693 closure_sync(&cl);
1694 c->sb.last_mount = get_seconds();
1695 bcache_write_super(c);
1696
1697 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1698 bch_cached_dev_attach(dc, c);
1699
1700 flash_devs_run(c);
1701
1702 set_bit(CACHE_SET_RUNNING, &c->flags);
1703 return;
1704 err:
1705 closure_sync(&cl);
1706 /* XXX: test this, it's broken */
1707 bch_cache_set_error(c, "%s", err);
1708 }
1709
1710 static bool can_attach_cache(struct cache *ca, struct cache_set *c)
1711 {
1712 return ca->sb.block_size == c->sb.block_size &&
1713 ca->sb.bucket_size == c->sb.bucket_size &&
1714 ca->sb.nr_in_set == c->sb.nr_in_set;
1715 }
1716
1717 static const char *register_cache_set(struct cache *ca)
1718 {
1719 char buf[12];
1720 const char *err = "cannot allocate memory";
1721 struct cache_set *c;
1722
1723 list_for_each_entry(c, &bch_cache_sets, list)
1724 if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
1725 if (c->cache[ca->sb.nr_this_dev])
1726 return "duplicate cache set member";
1727
1728 if (!can_attach_cache(ca, c))
1729 return "cache sb does not match set";
1730
1731 if (!CACHE_SYNC(&ca->sb))
1732 SET_CACHE_SYNC(&c->sb, false);
1733
1734 goto found;
1735 }
1736
1737 c = bch_cache_set_alloc(&ca->sb);
1738 if (!c)
1739 return err;
1740
1741 err = "error creating kobject";
1742 if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
1743 kobject_add(&c->internal, &c->kobj, "internal"))
1744 goto err;
1745
1746 if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
1747 goto err;
1748
1749 bch_debug_init_cache_set(c);
1750
1751 list_add(&c->list, &bch_cache_sets);
1752 found:
1753 sprintf(buf, "cache%i", ca->sb.nr_this_dev);
1754 if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
1755 sysfs_create_link(&c->kobj, &ca->kobj, buf))
1756 goto err;
1757
1758 if (ca->sb.seq > c->sb.seq) {
1759 c->sb.version = ca->sb.version;
1760 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
1761 c->sb.flags = ca->sb.flags;
1762 c->sb.seq = ca->sb.seq;
1763 pr_debug("set version = %llu", c->sb.version);
1764 }
1765
1766 kobject_get(&ca->kobj);
1767 ca->set = c;
1768 ca->set->cache[ca->sb.nr_this_dev] = ca;
1769 c->cache_by_alloc[c->caches_loaded++] = ca;
1770
1771 if (c->caches_loaded == c->sb.nr_in_set)
1772 run_cache_set(c);
1773
1774 return NULL;
1775 err:
1776 bch_cache_set_unregister(c);
1777 return err;
1778 }
1779
1780 /* Cache device */
1781
1782 void bch_cache_release(struct kobject *kobj)
1783 {
1784 struct cache *ca = container_of(kobj, struct cache, kobj);
1785 unsigned i;
1786
1787 if (ca->set) {
1788 BUG_ON(ca->set->cache[ca->sb.nr_this_dev] != ca);
1789 ca->set->cache[ca->sb.nr_this_dev] = NULL;
1790 }
1791
1792 free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
1793 kfree(ca->prio_buckets);
1794 vfree(ca->buckets);
1795
1796 free_heap(&ca->heap);
1797 free_fifo(&ca->free_inc);
1798
1799 for (i = 0; i < RESERVE_NR; i++)
1800 free_fifo(&ca->free[i]);
1801
1802 if (ca->sb_bio.bi_inline_vecs[0].bv_page)
1803 put_page(ca->sb_bio.bi_io_vec[0].bv_page);
1804
1805 if (!IS_ERR_OR_NULL(ca->bdev))
1806 blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1807
1808 kfree(ca);
1809 module_put(THIS_MODULE);
1810 }
1811
1812 static int cache_alloc(struct cache *ca)
1813 {
1814 size_t free;
1815 struct bucket *b;
1816
1817 __module_get(THIS_MODULE);
1818 kobject_init(&ca->kobj, &bch_cache_ktype);
1819
1820 bio_init(&ca->journal.bio, ca->journal.bio.bi_inline_vecs, 8);
1821
1822 free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
1823
1824 if (!init_fifo(&ca->free[RESERVE_BTREE], 8, GFP_KERNEL) ||
1825 !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
1826 !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
1827 !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
1828 !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
1829 !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
1830 !(ca->buckets = vzalloc(sizeof(struct bucket) *
1831 ca->sb.nbuckets)) ||
1832 !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
1833 2, GFP_KERNEL)) ||
1834 !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)))
1835 return -ENOMEM;
1836
1837 ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
1838
1839 for_each_bucket(b, ca)
1840 atomic_set(&b->pin, 0);
1841
1842 return 0;
1843 }
1844
1845 static int register_cache(struct cache_sb *sb, struct page *sb_page,
1846 struct block_device *bdev, struct cache *ca)
1847 {
1848 char name[BDEVNAME_SIZE];
1849 const char *err = NULL; /* must be set for any error case */
1850 int ret = 0;
1851
1852 memcpy(&ca->sb, sb, sizeof(struct cache_sb));
1853 ca->bdev = bdev;
1854 ca->bdev->bd_holder = ca;
1855
1856 bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1);
1857 ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
1858 get_page(sb_page);
1859
1860 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1861 ca->discard = CACHE_DISCARD(&ca->sb);
1862
1863 ret = cache_alloc(ca);
1864 if (ret != 0) {
1865 if (ret == -ENOMEM)
1866 err = "cache_alloc(): -ENOMEM";
1867 else
1868 err = "cache_alloc(): unknown error";
1869 goto err;
1870 }
1871
1872 if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache")) {
1873 err = "error calling kobject_add";
1874 ret = -ENOMEM;
1875 goto out;
1876 }
1877
1878 mutex_lock(&bch_register_lock);
1879 err = register_cache_set(ca);
1880 mutex_unlock(&bch_register_lock);
1881
1882 if (err) {
1883 ret = -ENODEV;
1884 goto out;
1885 }
1886
1887 pr_info("registered cache device %s", bdevname(bdev, name));
1888
1889 out:
1890 kobject_put(&ca->kobj);
1891
1892 err:
1893 if (err)
1894 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1895
1896 return ret;
1897 }
1898
1899 /* Global interfaces/init */
1900
1901 static ssize_t register_bcache(struct kobject *, struct kobj_attribute *,
1902 const char *, size_t);
1903
1904 kobj_attribute_write(register, register_bcache);
1905 kobj_attribute_write(register_quiet, register_bcache);
1906
1907 static bool bch_is_open_backing(struct block_device *bdev) {
1908 struct cache_set *c, *tc;
1909 struct cached_dev *dc, *t;
1910
1911 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1912 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1913 if (dc->bdev == bdev)
1914 return true;
1915 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1916 if (dc->bdev == bdev)
1917 return true;
1918 return false;
1919 }
1920
1921 static bool bch_is_open_cache(struct block_device *bdev) {
1922 struct cache_set *c, *tc;
1923 struct cache *ca;
1924 unsigned i;
1925
1926 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1927 for_each_cache(ca, c, i)
1928 if (ca->bdev == bdev)
1929 return true;
1930 return false;
1931 }
1932
1933 static bool bch_is_open(struct block_device *bdev) {
1934 return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
1935 }
1936
1937 static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
1938 const char *buffer, size_t size)
1939 {
1940 ssize_t ret = size;
1941 const char *err = "cannot allocate memory";
1942 char *path = NULL;
1943 struct cache_sb *sb = NULL;
1944 struct block_device *bdev = NULL;
1945 struct page *sb_page = NULL;
1946
1947 if (!try_module_get(THIS_MODULE))
1948 return -EBUSY;
1949
1950 if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
1951 !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
1952 goto err;
1953
1954 err = "failed to open device";
1955 bdev = blkdev_get_by_path(strim(path),
1956 FMODE_READ|FMODE_WRITE|FMODE_EXCL,
1957 sb);
1958 if (IS_ERR(bdev)) {
1959 if (bdev == ERR_PTR(-EBUSY)) {
1960 bdev = lookup_bdev(strim(path));
1961 mutex_lock(&bch_register_lock);
1962 if (!IS_ERR(bdev) && bch_is_open(bdev))
1963 err = "device already registered";
1964 else
1965 err = "device busy";
1966 mutex_unlock(&bch_register_lock);
1967 if (attr == &ksysfs_register_quiet)
1968 goto out;
1969 }
1970 goto err;
1971 }
1972
1973 err = "failed to set blocksize";
1974 if (set_blocksize(bdev, 4096))
1975 goto err_close;
1976
1977 err = read_super(sb, bdev, &sb_page);
1978 if (err)
1979 goto err_close;
1980
1981 if (SB_IS_BDEV(sb)) {
1982 struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
1983 if (!dc)
1984 goto err_close;
1985
1986 mutex_lock(&bch_register_lock);
1987 register_bdev(sb, sb_page, bdev, dc);
1988 mutex_unlock(&bch_register_lock);
1989 } else {
1990 struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1991 if (!ca)
1992 goto err_close;
1993
1994 if (register_cache(sb, sb_page, bdev, ca) != 0)
1995 goto err_close;
1996 }
1997 out:
1998 if (sb_page)
1999 put_page(sb_page);
2000 kfree(sb);
2001 kfree(path);
2002 module_put(THIS_MODULE);
2003 return ret;
2004
2005 err_close:
2006 blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2007 err:
2008 pr_info("error opening %s: %s", path, err);
2009 ret = -EINVAL;
2010 goto out;
2011 }
2012
2013 static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
2014 {
2015 if (code == SYS_DOWN ||
2016 code == SYS_HALT ||
2017 code == SYS_POWER_OFF) {
2018 DEFINE_WAIT(wait);
2019 unsigned long start = jiffies;
2020 bool stopped = false;
2021
2022 struct cache_set *c, *tc;
2023 struct cached_dev *dc, *tdc;
2024
2025 mutex_lock(&bch_register_lock);
2026
2027 if (list_empty(&bch_cache_sets) &&
2028 list_empty(&uncached_devices))
2029 goto out;
2030
2031 pr_info("Stopping all devices:");
2032
2033 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
2034 bch_cache_set_stop(c);
2035
2036 list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
2037 bcache_device_stop(&dc->disk);
2038
2039 /* What's a condition variable? */
2040 while (1) {
2041 long timeout = start + 2 * HZ - jiffies;
2042
2043 stopped = list_empty(&bch_cache_sets) &&
2044 list_empty(&uncached_devices);
2045
2046 if (timeout < 0 || stopped)
2047 break;
2048
2049 prepare_to_wait(&unregister_wait, &wait,
2050 TASK_UNINTERRUPTIBLE);
2051
2052 mutex_unlock(&bch_register_lock);
2053 schedule_timeout(timeout);
2054 mutex_lock(&bch_register_lock);
2055 }
2056
2057 finish_wait(&unregister_wait, &wait);
2058
2059 if (stopped)
2060 pr_info("All devices stopped");
2061 else
2062 pr_notice("Timeout waiting for devices to be closed");
2063 out:
2064 mutex_unlock(&bch_register_lock);
2065 }
2066
2067 return NOTIFY_DONE;
2068 }
2069
2070 static struct notifier_block reboot = {
2071 .notifier_call = bcache_reboot,
2072 .priority = INT_MAX, /* before any real devices */
2073 };
2074
2075 static void bcache_exit(void)
2076 {
2077 bch_debug_exit();
2078 bch_request_exit();
2079 if (bcache_kobj)
2080 kobject_put(bcache_kobj);
2081 if (bcache_wq)
2082 destroy_workqueue(bcache_wq);
2083 if (bcache_major)
2084 unregister_blkdev(bcache_major, "bcache");
2085 unregister_reboot_notifier(&reboot);
2086 }
2087
2088 static int __init bcache_init(void)
2089 {
2090 static const struct attribute *files[] = {
2091 &ksysfs_register.attr,
2092 &ksysfs_register_quiet.attr,
2093 NULL
2094 };
2095
2096 mutex_init(&bch_register_lock);
2097 init_waitqueue_head(&unregister_wait);
2098 register_reboot_notifier(&reboot);
2099 closure_debug_init();
2100
2101 bcache_major = register_blkdev(0, "bcache");
2102 if (bcache_major < 0) {
2103 unregister_reboot_notifier(&reboot);
2104 return bcache_major;
2105 }
2106
2107 if (!(bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) ||
2108 !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
2109 sysfs_create_files(bcache_kobj, files) ||
2110 bch_request_init() ||
2111 bch_debug_init(bcache_kobj))
2112 goto err;
2113
2114 return 0;
2115 err:
2116 bcache_exit();
2117 return -ENOMEM;
2118 }
2119
2120 module_exit(bcache_exit);
2121 module_init(bcache_init);
Linux with added FPC-III support