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doc: Fix typo in documentation/bcache.txt
[deliverable/linux.git] / drivers / md / bcache / super.c
CommitLineData
cafe5635
KO		 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 "request.h"
279afbad 13#include "writeback.h"
cafe5635 14
c37511b8 15#include <linux/blkdev.h>
cafe5635
KO		 16#include <linux/buffer_head.h>
17#include <linux/debugfs.h>
18#include <linux/genhd.h>
19#include <linux/module.h>
20#include <linux/random.h>
21#include <linux/reboot.h>
22#include <linux/sysfs.h>
23
24MODULE_LICENSE("GPL");
25MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
26
27static const char bcache_magic[] = {
28 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
29 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
30};
31
32static const char invalid_uuid[] = {
33 0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78,
34 0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99
35};
36
37/* Default is -1; we skip past it for struct cached_dev's cache mode */
38const char * const bch_cache_modes[] = {
39 "default",
40 "writethrough",
41 "writeback",
42 "writearound",
43 "none",
44 NULL
45};
46
47struct uuid_entry_v0 {
48 uint8_t uuid[16];
49 uint8_t label[32];
50 uint32_t first_reg;
51 uint32_t last_reg;
52 uint32_t invalidated;
53 uint32_t pad;
54};
55
56static struct kobject *bcache_kobj;
57struct mutex bch_register_lock;
58LIST_HEAD(bch_cache_sets);
59static LIST_HEAD(uncached_devices);
60
61static int bcache_major, bcache_minor;
62static wait_queue_head_t unregister_wait;
63struct workqueue_struct *bcache_wq;
64
65#define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE)
66
67static void bio_split_pool_free(struct bio_split_pool *p)
68{
8ef74790
KO		 69 if (p->bio_split_hook)
70 mempool_destroy(p->bio_split_hook);
71
cafe5635
KO		 72 if (p->bio_split)
73 bioset_free(p->bio_split);
cafe5635
KO		 74}
75
76static int bio_split_pool_init(struct bio_split_pool *p)
77{
78 p->bio_split = bioset_create(4, 0);
79 if (!p->bio_split)
80 return -ENOMEM;
81
82 p->bio_split_hook = mempool_create_kmalloc_pool(4,
83 sizeof(struct bio_split_hook));
84 if (!p->bio_split_hook)
85 return -ENOMEM;
86
87 return 0;
88}
89
90/* Superblock */
91
92static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
93 struct page **res)
94{
95 const char *err;
96 struct cache_sb *s;
97 struct buffer_head *bh = __bread(bdev, 1, SB_SIZE);
98 unsigned i;
99
100 if (!bh)
101 return "IO error";
102
103 s = (struct cache_sb *) bh->b_data;
104
105 sb->offset = le64_to_cpu(s->offset);
106 sb->version = le64_to_cpu(s->version);
107
108 memcpy(sb->magic, s->magic, 16);
109 memcpy(sb->uuid, s->uuid, 16);
110 memcpy(sb->set_uuid, s->set_uuid, 16);
111 memcpy(sb->label, s->label, SB_LABEL_SIZE);
112
113 sb->flags = le64_to_cpu(s->flags);
114 sb->seq = le64_to_cpu(s->seq);
cafe5635 115 sb->last_mount = le32_to_cpu(s->last_mount);
cafe5635
KO		 116 sb->first_bucket = le16_to_cpu(s->first_bucket);
117 sb->keys = le16_to_cpu(s->keys);
118
119 for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
120 sb->d[i] = le64_to_cpu(s->d[i]);
121
122 pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
123 sb->version, sb->flags, sb->seq, sb->keys);
124
125 err = "Not a bcache superblock";
126 if (sb->offset != SB_SECTOR)
127 goto err;
128
129 if (memcmp(sb->magic, bcache_magic, 16))
130 goto err;
131
132 err = "Too many journal buckets";
133 if (sb->keys > SB_JOURNAL_BUCKETS)
134 goto err;
135
136 err = "Bad checksum";
137 if (s->csum != csum_set(s))
138 goto err;
139
140 err = "Bad UUID";
169ef1cf 141 if (bch_is_zero(sb->uuid, 16))
cafe5635
KO		 142 goto err;
143
8abb2a5d
KO		 144 sb->block_size = le16_to_cpu(s->block_size);
145
146 err = "Superblock block size smaller than device block size";
147 if (sb->block_size << 9 < bdev_logical_block_size(bdev))
148 goto err;
149
2903381f
KO		 150 switch (sb->version) {
151 case BCACHE_SB_VERSION_BDEV:
2903381f
KO		 152 sb->data_offset = BDEV_DATA_START_DEFAULT;
153 break;
154 case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
2903381f
KO		 155 sb->data_offset = le64_to_cpu(s->data_offset);
156
157 err = "Bad data offset";
158 if (sb->data_offset < BDEV_DATA_START_DEFAULT)
159 goto err;
cafe5635 160
2903381f
KO		 161 break;
162 case BCACHE_SB_VERSION_CDEV:
163 case BCACHE_SB_VERSION_CDEV_WITH_UUID:
164 sb->nbuckets = le64_to_cpu(s->nbuckets);
165 sb->block_size = le16_to_cpu(s->block_size);
166 sb->bucket_size = le16_to_cpu(s->bucket_size);
cafe5635 167
2903381f
KO		 168 sb->nr_in_set = le16_to_cpu(s->nr_in_set);
169 sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
cafe5635 170
2903381f
KO		 171 err = "Too many buckets";
172 if (sb->nbuckets > LONG_MAX)
173 goto err;
cafe5635 174
2903381f
KO		 175 err = "Not enough buckets";
176 if (sb->nbuckets < 1 << 7)
177 goto err;
cafe5635 178
2903381f
KO		 179 err = "Bad block/bucket size";
180 if (!is_power_of_2(sb->block_size) ||
181 sb->block_size > PAGE_SECTORS ||
182 !is_power_of_2(sb->bucket_size) ||
183 sb->bucket_size < PAGE_SECTORS)
184 goto err;
cafe5635 185
2903381f
KO		 186 err = "Invalid superblock: device too small";
187 if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
188 goto err;
cafe5635 189
2903381f
KO		 190 err = "Bad UUID";
191 if (bch_is_zero(sb->set_uuid, 16))
192 goto err;
cafe5635 193
2903381f
KO		 194 err = "Bad cache device number in set";
195 if (!sb->nr_in_set ||
196 sb->nr_in_set <= sb->nr_this_dev ||
197 sb->nr_in_set > MAX_CACHES_PER_SET)
cafe5635
KO		 198 goto err;
199
2903381f
KO		 200 err = "Journal buckets not sequential";
201 for (i = 0; i < sb->keys; i++)
202 if (sb->d[i] != sb->first_bucket + i)
203 goto err;
cafe5635 204
2903381f
KO		 205 err = "Too many journal buckets";
206 if (sb->first_bucket + sb->keys > sb->nbuckets)
207 goto err;
208
209 err = "Invalid superblock: first bucket comes before end of super";
210 if (sb->first_bucket * sb->bucket_size < 16)
211 goto err;
212
213 break;
214 default:
215 err = "Unsupported superblock version";
cafe5635 216 goto err;
2903381f
KO		 217 }
218
cafe5635
KO		 219 sb->last_mount = get_seconds();
220 err = NULL;
221
222 get_page(bh->b_page);
223 *res = bh->b_page;
224err:
225 put_bh(bh);
226 return err;
227}
228
229static void write_bdev_super_endio(struct bio *bio, int error)
230{
231 struct cached_dev *dc = bio->bi_private;
232 /* XXX: error checking */
233
234 closure_put(&dc->sb_write.cl);
235}
236
237static void __write_super(struct cache_sb *sb, struct bio *bio)
238{
239 struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
240 unsigned i;
241
242 bio->bi_sector = SB_SECTOR;
243 bio->bi_rw = REQ_SYNC|REQ_META;
244 bio->bi_size = SB_SIZE;
169ef1cf 245 bch_bio_map(bio, NULL);
cafe5635
KO		 246
247 out->offset = cpu_to_le64(sb->offset);
248 out->version = cpu_to_le64(sb->version);
249
250 memcpy(out->uuid, sb->uuid, 16);
251 memcpy(out->set_uuid, sb->set_uuid, 16);
252 memcpy(out->label, sb->label, SB_LABEL_SIZE);
253
254 out->flags = cpu_to_le64(sb->flags);
255 out->seq = cpu_to_le64(sb->seq);
256
257 out->last_mount = cpu_to_le32(sb->last_mount);
258 out->first_bucket = cpu_to_le16(sb->first_bucket);
259 out->keys = cpu_to_le16(sb->keys);
260
261 for (i = 0; i < sb->keys; i++)
262 out->d[i] = cpu_to_le64(sb->d[i]);
263
264 out->csum = csum_set(out);
265
266 pr_debug("ver %llu, flags %llu, seq %llu",
267 sb->version, sb->flags, sb->seq);
268
269 submit_bio(REQ_WRITE, bio);
270}
271
272void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
273{
274 struct closure *cl = &dc->sb_write.cl;
275 struct bio *bio = &dc->sb_bio;
276
277 closure_lock(&dc->sb_write, parent);
278
279 bio_reset(bio);
280 bio->bi_bdev = dc->bdev;
281 bio->bi_end_io = write_bdev_super_endio;
282 bio->bi_private = dc;
283
284 closure_get(cl);
285 __write_super(&dc->sb, bio);
286
287 closure_return(cl);
288}
289
290static void write_super_endio(struct bio *bio, int error)
291{
292 struct cache *ca = bio->bi_private;
293
294 bch_count_io_errors(ca, error, "writing superblock");
295 closure_put(&ca->set->sb_write.cl);
296}
297
298void bcache_write_super(struct cache_set *c)
299{
300 struct closure *cl = &c->sb_write.cl;
301 struct cache *ca;
302 unsigned i;
303
304 closure_lock(&c->sb_write, &c->cl);
305
306 c->sb.seq++;
307
308 for_each_cache(ca, c, i) {
309 struct bio *bio = &ca->sb_bio;
310
2903381f 311 ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
cafe5635
KO		 312 ca->sb.seq = c->sb.seq;
313 ca->sb.last_mount = c->sb.last_mount;
314
315 SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb));
316
317 bio_reset(bio);
318 bio->bi_bdev = ca->bdev;
319 bio->bi_end_io = write_super_endio;
320 bio->bi_private = ca;
321
322 closure_get(cl);
323 __write_super(&ca->sb, bio);
324 }
325
326 closure_return(cl);
327}
328
329/* UUID io */
330
331static void uuid_endio(struct bio *bio, int error)
332{
333 struct closure *cl = bio->bi_private;
334 struct cache_set *c = container_of(cl, struct cache_set, uuid_write.cl);
335
336 cache_set_err_on(error, c, "accessing uuids");
337 bch_bbio_free(bio, c);
338 closure_put(cl);
339}
340
341static void uuid_io(struct cache_set *c, unsigned long rw,
342 struct bkey *k, struct closure *parent)
343{
344 struct closure *cl = &c->uuid_write.cl;
345 struct uuid_entry *u;
346 unsigned i;
85b1492e 347 char buf[80];
cafe5635
KO		 348
349 BUG_ON(!parent);
350 closure_lock(&c->uuid_write, parent);
351
352 for (i = 0; i < KEY_PTRS(k); i++) {
353 struct bio *bio = bch_bbio_alloc(c);
354
355 bio->bi_rw = REQ_SYNC|REQ_META|rw;
356 bio->bi_size = KEY_SIZE(k) << 9;
357
358 bio->bi_end_io = uuid_endio;
359 bio->bi_private = cl;
169ef1cf 360 bch_bio_map(bio, c->uuids);
cafe5635
KO		 361
362 bch_submit_bbio(bio, c, k, i);
363
364 if (!(rw & WRITE))
365 break;
366 }
367
85b1492e
KO		 368 bch_bkey_to_text(buf, sizeof(buf), k);
369 pr_debug("%s UUIDs at %s", rw & REQ_WRITE ? "wrote" : "read", buf);
cafe5635
KO		 370
371 for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
169ef1cf 372 if (!bch_is_zero(u->uuid, 16))
cafe5635
KO		 373 pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
374 u - c->uuids, u->uuid, u->label,
375 u->first_reg, u->last_reg, u->invalidated);
376
377 closure_return(cl);
378}
379
380static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
381{
382 struct bkey *k = &j->uuid_bucket;
383
384 if (__bch_ptr_invalid(c, 1, k))
385 return "bad uuid pointer";
386
387 bkey_copy(&c->uuid_bucket, k);
388 uuid_io(c, READ_SYNC, k, cl);
389
390 if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
391 struct uuid_entry_v0 *u0 = (void *) c->uuids;
392 struct uuid_entry *u1 = (void *) c->uuids;
393 int i;
394
395 closure_sync(cl);
396
397 /*
398 * Since the new uuid entry is bigger than the old, we have to
399 * convert starting at the highest memory address and work down
400 * in order to do it in place
401 */
402
403 for (i = c->nr_uuids - 1;
404 i >= 0;
405 --i) {
406 memcpy(u1[i].uuid, u0[i].uuid, 16);
407 memcpy(u1[i].label, u0[i].label, 32);
408
409 u1[i].first_reg = u0[i].first_reg;
410 u1[i].last_reg = u0[i].last_reg;
411 u1[i].invalidated = u0[i].invalidated;
412
413 u1[i].flags = 0;
414 u1[i].sectors = 0;
415 }
416 }
417
418 return NULL;
419}
420
421static int __uuid_write(struct cache_set *c)
422{
423 BKEY_PADDED(key) k;
424 struct closure cl;
425 closure_init_stack(&cl);
426
427 lockdep_assert_held(&bch_register_lock);
428
429 if (bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, &cl))
430 return 1;
431
432 SET_KEY_SIZE(&k.key, c->sb.bucket_size);
433 uuid_io(c, REQ_WRITE, &k.key, &cl);
434 closure_sync(&cl);
435
436 bkey_copy(&c->uuid_bucket, &k.key);
437 __bkey_put(c, &k.key);
438 return 0;
439}
440
441int bch_uuid_write(struct cache_set *c)
442{
443 int ret = __uuid_write(c);
444
445 if (!ret)
446 bch_journal_meta(c, NULL);
447
448 return ret;
449}
450
451static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
452{
453 struct uuid_entry *u;
454
455 for (u = c->uuids;
456 u < c->uuids + c->nr_uuids; u++)
457 if (!memcmp(u->uuid, uuid, 16))
458 return u;
459
460 return NULL;
461}
462
463static struct uuid_entry *uuid_find_empty(struct cache_set *c)
464{
465 static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
466 return uuid_find(c, zero_uuid);
467}
468
469/*
470 * Bucket priorities/gens:
471 *
472 * For each bucket, we store on disk its
473 * 8 bit gen
474 * 16 bit priority
475 *
476 * See alloc.c for an explanation of the gen. The priority is used to implement
477 * lru (and in the future other) cache replacement policies; for most purposes
478 * it's just an opaque integer.
479 *
480 * The gens and the priorities don't have a whole lot to do with each other, and
481 * it's actually the gens that must be written out at specific times - it's no
482 * big deal if the priorities don't get written, if we lose them we just reuse
483 * buckets in suboptimal order.
484 *
485 * On disk they're stored in a packed array, and in as many buckets are required
486 * to fit them all. The buckets we use to store them form a list; the journal
487 * header points to the first bucket, the first bucket points to the second
488 * bucket, et cetera.
489 *
490 * This code is used by the allocation code; periodically (whenever it runs out
491 * of buckets to allocate from) the allocation code will invalidate some
492 * buckets, but it can't use those buckets until their new gens are safely on
493 * disk.
494 */
495
496static void prio_endio(struct bio *bio, int error)
497{
498 struct cache *ca = bio->bi_private;
499
500 cache_set_err_on(error, ca->set, "accessing priorities");
501 bch_bbio_free(bio, ca->set);
502 closure_put(&ca->prio);
503}
504
505static void prio_io(struct cache *ca, uint64_t bucket, unsigned long rw)
506{
507 struct closure *cl = &ca->prio;
508 struct bio *bio = bch_bbio_alloc(ca->set);
509
510 closure_init_stack(cl);
511
512 bio->bi_sector = bucket * ca->sb.bucket_size;
513 bio->bi_bdev = ca->bdev;
514 bio->bi_rw = REQ_SYNC|REQ_META|rw;
515 bio->bi_size = bucket_bytes(ca);
516
517 bio->bi_end_io = prio_endio;
518 bio->bi_private = ca;
169ef1cf 519 bch_bio_map(bio, ca->disk_buckets);
cafe5635
KO		 520
521 closure_bio_submit(bio, &ca->prio, ca);
522 closure_sync(cl);
523}
524
525#define buckets_free(c) "free %zu, free_inc %zu, unused %zu", \
526 fifo_used(&c->free), fifo_used(&c->free_inc), fifo_used(&c->unused)
527
528void bch_prio_write(struct cache *ca)
529{
530 int i;
531 struct bucket *b;
532 struct closure cl;
533
534 closure_init_stack(&cl);
535
536 lockdep_assert_held(&ca->set->bucket_lock);
537
538 for (b = ca->buckets;
539 b < ca->buckets + ca->sb.nbuckets; b++)
540 b->disk_gen = b->gen;
541
542 ca->disk_buckets->seq++;
543
544 atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
545 &ca->meta_sectors_written);
546
547 pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free),
548 fifo_used(&ca->free_inc), fifo_used(&ca->unused));
cafe5635
KO		 549
550 for (i = prio_buckets(ca) - 1; i >= 0; --i) {
551 long bucket;
552 struct prio_set *p = ca->disk_buckets;
b1a67b0f
KO		 553 struct bucket_disk *d = p->data;
554 struct bucket_disk *end = d + prios_per_bucket(ca);
cafe5635
KO		 555
556 for (b = ca->buckets + i * prios_per_bucket(ca);
557 b < ca->buckets + ca->sb.nbuckets && d < end;
558 b++, d++) {
559 d->prio = cpu_to_le16(b->prio);
560 d->gen = b->gen;
561 }
562
563 p->next_bucket = ca->prio_buckets[i + 1];
564 p->magic = pset_magic(ca);
169ef1cf 565 p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8);
cafe5635
KO		 566
567 bucket = bch_bucket_alloc(ca, WATERMARK_PRIO, &cl);
568 BUG_ON(bucket == -1);
569
570 mutex_unlock(&ca->set->bucket_lock);
571 prio_io(ca, bucket, REQ_WRITE);
572 mutex_lock(&ca->set->bucket_lock);
573
574 ca->prio_buckets[i] = bucket;
575 atomic_dec_bug(&ca->buckets[bucket].pin);
576 }
577
578 mutex_unlock(&ca->set->bucket_lock);
579
580 bch_journal_meta(ca->set, &cl);
581 closure_sync(&cl);
582
583 mutex_lock(&ca->set->bucket_lock);
584
585 ca->need_save_prio = 0;
586
587 /*
588 * Don't want the old priorities to get garbage collected until after we
589 * finish writing the new ones, and they're journalled
590 */
591 for (i = 0; i < prio_buckets(ca); i++)
592 ca->prio_last_buckets[i] = ca->prio_buckets[i];
593}
594
595static void prio_read(struct cache *ca, uint64_t bucket)
596{
597 struct prio_set *p = ca->disk_buckets;
598 struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
599 struct bucket *b;
600 unsigned bucket_nr = 0;
601
602 for (b = ca->buckets;
603 b < ca->buckets + ca->sb.nbuckets;
604 b++, d++) {
605 if (d == end) {
606 ca->prio_buckets[bucket_nr] = bucket;
607 ca->prio_last_buckets[bucket_nr] = bucket;
608 bucket_nr++;
609
610 prio_io(ca, bucket, READ_SYNC);
611
169ef1cf 612 if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8))
cafe5635
KO		 613 pr_warn("bad csum reading priorities");
614
615 if (p->magic != pset_magic(ca))
616 pr_warn("bad magic reading priorities");
617
618 bucket = p->next_bucket;
619 d = p->data;
620 }
621
622 b->prio = le16_to_cpu(d->prio);
623 b->gen = b->disk_gen = b->last_gc = b->gc_gen = d->gen;
624 }
625}
626
627/* Bcache device */
628
629static int open_dev(struct block_device *b, fmode_t mode)
630{
631 struct bcache_device *d = b->bd_disk->private_data;
632 if (atomic_read(&d->closing))
633 return -ENXIO;
634
635 closure_get(&d->cl);
636 return 0;
637}
638
867e1162 639static void release_dev(struct gendisk *b, fmode_t mode)
cafe5635
KO		 640{
641 struct bcache_device *d = b->private_data;
642 closure_put(&d->cl);
cafe5635
KO		 643}
644
645static int ioctl_dev(struct block_device *b, fmode_t mode,
646 unsigned int cmd, unsigned long arg)
647{
648 struct bcache_device *d = b->bd_disk->private_data;
649 return d->ioctl(d, mode, cmd, arg);
650}
651
652static const struct block_device_operations bcache_ops = {
653 .open = open_dev,
654 .release = release_dev,
655 .ioctl = ioctl_dev,
656 .owner = THIS_MODULE,
657};
658
659void bcache_device_stop(struct bcache_device *d)
660{
661 if (!atomic_xchg(&d->closing, 1))
662 closure_queue(&d->cl);
663}
664
ee668506
KO		 665static void bcache_device_unlink(struct bcache_device *d)
666{
667 unsigned i;
668 struct cache *ca;
669
670 sysfs_remove_link(&d->c->kobj, d->name);
671 sysfs_remove_link(&d->kobj, "cache");
672
673 for_each_cache(ca, d->c, i)
674 bd_unlink_disk_holder(ca->bdev, d->disk);
675}
676
677static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
678 const char *name)
679{
680 unsigned i;
681 struct cache *ca;
682
683 for_each_cache(ca, d->c, i)
684 bd_link_disk_holder(ca->bdev, d->disk);
685
686 snprintf(d->name, BCACHEDEVNAME_SIZE,
687 "%s%u", name, d->id);
688
689 WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
690 sysfs_create_link(&c->kobj, &d->kobj, d->name),
691 "Couldn't create device <-> cache set symlinks");
692}
693
cafe5635
KO		 694static void bcache_device_detach(struct bcache_device *d)
695{
696 lockdep_assert_held(&bch_register_lock);
697
698 if (atomic_read(&d->detaching)) {
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 atomic_set(&d->detaching, 0);
707 }
708
ee668506
KO		 709 bcache_device_unlink(d);
710
cafe5635
KO		 711 d->c->devices[d->id] = NULL;
712 closure_put(&d->c->caching);
713 d->c = NULL;
714}
715
716static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
717 unsigned id)
718{
719 BUG_ON(test_bit(CACHE_SET_STOPPING, &c->flags));
720
721 d->id = id;
722 d->c = c;
723 c->devices[id] = d;
724
725 closure_get(&c->caching);
726}
727
cafe5635
KO		 728static void bcache_device_free(struct bcache_device *d)
729{
730 lockdep_assert_held(&bch_register_lock);
731
732 pr_info("%s stopped", d->disk->disk_name);
733
734 if (d->c)
735 bcache_device_detach(d);
f59fce84 736 if (d->disk && d->disk->flags & GENHD_FL_UP)
cafe5635
KO		 737 del_gendisk(d->disk);
738 if (d->disk && d->disk->queue)
739 blk_cleanup_queue(d->disk->queue);
740 if (d->disk)
741 put_disk(d->disk);
742
743 bio_split_pool_free(&d->bio_split_hook);
744 if (d->unaligned_bvec)
745 mempool_destroy(d->unaligned_bvec);
746 if (d->bio_split)
747 bioset_free(d->bio_split);
279afbad
KO		 748 if (is_vmalloc_addr(d->stripe_sectors_dirty))
749 vfree(d->stripe_sectors_dirty);
750 else
751 kfree(d->stripe_sectors_dirty);
cafe5635
KO		 752
753 closure_debug_destroy(&d->cl);
754}
755
279afbad
KO		 756static int bcache_device_init(struct bcache_device *d, unsigned block_size,
757 sector_t sectors)
cafe5635
KO		 758{
759 struct request_queue *q;
279afbad
KO		 760 size_t n;
761
762 if (!d->stripe_size_bits)
763 d->stripe_size_bits = 31;
764
765 d->nr_stripes = round_up(sectors, 1 << d->stripe_size_bits) >>
766 d->stripe_size_bits;
767
768 if (!d->nr_stripes || d->nr_stripes > SIZE_MAX / sizeof(atomic_t))
769 return -ENOMEM;
770
771 n = d->nr_stripes * sizeof(atomic_t);
772 d->stripe_sectors_dirty = n < PAGE_SIZE << 6
773 ? kzalloc(n, GFP_KERNEL)
774 : vzalloc(n);
775 if (!d->stripe_sectors_dirty)
776 return -ENOMEM;
cafe5635
KO		 777
778 if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
779 !(d->unaligned_bvec = mempool_create_kmalloc_pool(1,
780 sizeof(struct bio_vec) * BIO_MAX_PAGES)) ||
f59fce84
KO		 781 bio_split_pool_init(&d->bio_split_hook) ||
782 !(d->disk = alloc_disk(1)) ||
783 !(q = blk_alloc_queue(GFP_KERNEL)))
cafe5635
KO		 784 return -ENOMEM;
785
279afbad 786 set_capacity(d->disk, sectors);
cafe5635
KO		 787 snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", bcache_minor);
788
789 d->disk->major = bcache_major;
790 d->disk->first_minor = bcache_minor++;
791 d->disk->fops = &bcache_ops;
792 d->disk->private_data = d;
793
cafe5635
KO		 794 blk_queue_make_request(q, NULL);
795 d->disk->queue = q;
796 q->queuedata = d;
797 q->backing_dev_info.congested_data = d;
798 q->limits.max_hw_sectors = UINT_MAX;
799 q->limits.max_sectors = UINT_MAX;
800 q->limits.max_segment_size = UINT_MAX;
801 q->limits.max_segments = BIO_MAX_PAGES;
802 q->limits.max_discard_sectors = UINT_MAX;
803 q->limits.io_min = block_size;
804 q->limits.logical_block_size = block_size;
805 q->limits.physical_block_size = block_size;
806 set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags);
807 set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags);
808
809 return 0;
810}
811
812/* Cached device */
813
814static void calc_cached_dev_sectors(struct cache_set *c)
815{
816 uint64_t sectors = 0;
817 struct cached_dev *dc;
818
819 list_for_each_entry(dc, &c->cached_devs, list)
820 sectors += bdev_sectors(dc->bdev);
821
822 c->cached_dev_sectors = sectors;
823}
824
825void bch_cached_dev_run(struct cached_dev *dc)
826{
827 struct bcache_device *d = &dc->disk;
828
829 if (atomic_xchg(&dc->running, 1))
830 return;
831
832 if (!d->c &&
833 BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
834 struct closure cl;
835 closure_init_stack(&cl);
836
837 SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
838 bch_write_bdev_super(dc, &cl);
839 closure_sync(&cl);
840 }
841
842 add_disk(d->disk);
ee668506 843 bd_link_disk_holder(dc->bdev, dc->disk.disk);
cafe5635
KO		 844#if 0
845 char *env[] = { "SYMLINK=label" , NULL };
846 kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
847#endif
848 if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
849 sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache"))
850 pr_debug("error creating sysfs link");
851}
852
853static void cached_dev_detach_finish(struct work_struct *w)
854{
855 struct cached_dev *dc = container_of(w, struct cached_dev, detach);
856 char buf[BDEVNAME_SIZE];
857 struct closure cl;
858 closure_init_stack(&cl);
859
860 BUG_ON(!atomic_read(&dc->disk.detaching));
861 BUG_ON(atomic_read(&dc->count));
862
cafe5635
KO		 863 mutex_lock(&bch_register_lock);
864
865 memset(&dc->sb.set_uuid, 0, 16);
866 SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
867
868 bch_write_bdev_super(dc, &cl);
869 closure_sync(&cl);
870
871 bcache_device_detach(&dc->disk);
872 list_move(&dc->list, &uncached_devices);
873
874 mutex_unlock(&bch_register_lock);
875
876 pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
877
878 /* Drop ref we took in cached_dev_detach() */
879 closure_put(&dc->disk.cl);
880}
881
882void bch_cached_dev_detach(struct cached_dev *dc)
883{
884 lockdep_assert_held(&bch_register_lock);
885
886 if (atomic_read(&dc->disk.closing))
887 return;
888
889 if (atomic_xchg(&dc->disk.detaching, 1))
890 return;
891
892 /*
893 * Block the device from being closed and freed until we're finished
894 * detaching
895 */
896 closure_get(&dc->disk.cl);
897
898 bch_writeback_queue(dc);
899 cached_dev_put(dc);
900}
901
902int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c)
903{
904 uint32_t rtime = cpu_to_le32(get_seconds());
905 struct uuid_entry *u;
906 char buf[BDEVNAME_SIZE];
907
908 bdevname(dc->bdev, buf);
909
910 if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16))
911 return -ENOENT;
912
913 if (dc->disk.c) {
914 pr_err("Can't attach %s: already attached", buf);
915 return -EINVAL;
916 }
917
918 if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
919 pr_err("Can't attach %s: shutting down", buf);
920 return -EINVAL;
921 }
922
923 if (dc->sb.block_size < c->sb.block_size) {
924 /* Will die */
b1a67b0f
KO		 925 pr_err("Couldn't attach %s: block size less than set's block size",
926 buf);
cafe5635
KO		 927 return -EINVAL;
928 }
929
930 u = uuid_find(c, dc->sb.uuid);
931
932 if (u &&
933 (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
934 BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
935 memcpy(u->uuid, invalid_uuid, 16);
936 u->invalidated = cpu_to_le32(get_seconds());
937 u = NULL;
938 }
939
940 if (!u) {
941 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
942 pr_err("Couldn't find uuid for %s in set", buf);
943 return -ENOENT;
944 }
945
946 u = uuid_find_empty(c);
947 if (!u) {
948 pr_err("Not caching %s, no room for UUID", buf);
949 return -EINVAL;
950 }
951 }
952
953 /* Deadlocks since we're called via sysfs...
954 sysfs_remove_file(&dc->kobj, &sysfs_attach);
955 */
956
169ef1cf 957 if (bch_is_zero(u->uuid, 16)) {
cafe5635
KO		 958 struct closure cl;
959 closure_init_stack(&cl);
960
961 memcpy(u->uuid, dc->sb.uuid, 16);
962 memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
963 u->first_reg = u->last_reg = rtime;
964 bch_uuid_write(c);
965
966 memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
967 SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
968
969 bch_write_bdev_super(dc, &cl);
970 closure_sync(&cl);
971 } else {
972 u->last_reg = rtime;
973 bch_uuid_write(c);
974 }
975
976 bcache_device_attach(&dc->disk, c, u - c->uuids);
cafe5635
KO		 977 list_move(&dc->list, &c->cached_devs);
978 calc_cached_dev_sectors(c);
979
980 smp_wmb();
981 /*
982 * dc->c must be set before dc->count != 0 - paired with the mb in
983 * cached_dev_get()
984 */
985 atomic_set(&dc->count, 1);
986
987 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
444fc0b6 988 bch_sectors_dirty_init(dc);
cafe5635
KO		 989 atomic_set(&dc->has_dirty, 1);
990 atomic_inc(&dc->count);
991 bch_writeback_queue(dc);
992 }
993
994 bch_cached_dev_run(dc);
ee668506 995 bcache_device_link(&dc->disk, c, "bdev");
cafe5635
KO		 996
997 pr_info("Caching %s as %s on set %pU",
998 bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
999 dc->disk.c->sb.set_uuid);
1000 return 0;
1001}
1002
1003void bch_cached_dev_release(struct kobject *kobj)
1004{
1005 struct cached_dev *dc = container_of(kobj, struct cached_dev,
1006 disk.kobj);
1007 kfree(dc);
1008 module_put(THIS_MODULE);
1009}
1010
1011static void cached_dev_free(struct closure *cl)
1012{
1013 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1014
1015 cancel_delayed_work_sync(&dc->writeback_rate_update);
1016
1017 mutex_lock(&bch_register_lock);
1018
f59fce84
KO		 1019 if (atomic_read(&dc->running))
1020 bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
cafe5635
KO		 1021 bcache_device_free(&dc->disk);
1022 list_del(&dc->list);
1023
1024 mutex_unlock(&bch_register_lock);
1025
1026 if (!IS_ERR_OR_NULL(dc->bdev)) {
f59fce84
KO		 1027 if (dc->bdev->bd_disk)
1028 blk_sync_queue(bdev_get_queue(dc->bdev));
1029
cafe5635
KO		 1030 blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1031 }
1032
1033 wake_up(&unregister_wait);
1034
1035 kobject_put(&dc->disk.kobj);
1036}
1037
1038static void cached_dev_flush(struct closure *cl)
1039{
1040 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1041 struct bcache_device *d = &dc->disk;
1042
1043 bch_cache_accounting_destroy(&dc->accounting);
1044 kobject_del(&d->kobj);
1045
1046 continue_at(cl, cached_dev_free, system_wq);
1047}
1048
1049static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
1050{
f59fce84 1051 int ret;
cafe5635 1052 struct io *io;
f59fce84 1053 struct request_queue *q = bdev_get_queue(dc->bdev);
cafe5635
KO		 1054
1055 __module_get(THIS_MODULE);
1056 INIT_LIST_HEAD(&dc->list);
f59fce84
KO		 1057 closure_init(&dc->disk.cl, NULL);
1058 set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
cafe5635 1059 kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
cafe5635 1060 INIT_WORK(&dc->detach, cached_dev_detach_finish);
f59fce84
KO		 1061 closure_init_unlocked(&dc->sb_write);
1062 INIT_LIST_HEAD(&dc->io_lru);
1063 spin_lock_init(&dc->io_lock);
1064 bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
cafe5635
KO		 1065
1066 dc->sequential_merge = true;
1067 dc->sequential_cutoff = 4 << 20;
1068
cafe5635
KO		 1069 for (io = dc->io; io < dc->io + RECENT_IO; io++) {
1070 list_add(&io->lru, &dc->io_lru);
1071 hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
1072 }
1073
279afbad
KO		 1074 ret = bcache_device_init(&dc->disk, block_size,
1075 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
f59fce84
KO		 1076 if (ret)
1077 return ret;
1078
1079 set_capacity(dc->disk.disk,
1080 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1081
1082 dc->disk.disk->queue->backing_dev_info.ra_pages =
1083 max(dc->disk.disk->queue->backing_dev_info.ra_pages,
1084 q->backing_dev_info.ra_pages);
1085
1086 bch_cached_dev_request_init(dc);
1087 bch_cached_dev_writeback_init(dc);
cafe5635 1088 return 0;
cafe5635
KO		 1089}
1090
1091/* Cached device - bcache superblock */
1092
f59fce84 1093static void register_bdev(struct cache_sb *sb, struct page *sb_page,
cafe5635
KO		 1094 struct block_device *bdev,
1095 struct cached_dev *dc)
1096{
1097 char name[BDEVNAME_SIZE];
1098 const char *err = "cannot allocate memory";
cafe5635
KO		 1099 struct cache_set *c;
1100
cafe5635 1101 memcpy(&dc->sb, sb, sizeof(struct cache_sb));
cafe5635
KO		 1102 dc->bdev = bdev;
1103 dc->bdev->bd_holder = dc;
1104
f59fce84
KO		 1105 bio_init(&dc->sb_bio);
1106 dc->sb_bio.bi_max_vecs = 1;
1107 dc->sb_bio.bi_io_vec = dc->sb_bio.bi_inline_vecs;
1108 dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
1109 get_page(sb_page);
4f0fd955 1110
f59fce84
KO		 1111 if (cached_dev_init(dc, sb->block_size << 9))
1112 goto err;
cafe5635
KO		 1113
1114 err = "error creating kobject";
1115 if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
1116 "bcache"))
1117 goto err;
1118 if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
1119 goto err;
1120
f59fce84
KO		 1121 pr_info("registered backing device %s", bdevname(bdev, name));
1122
cafe5635
KO		 1123 list_add(&dc->list, &uncached_devices);
1124 list_for_each_entry(c, &bch_cache_sets, list)
1125 bch_cached_dev_attach(dc, c);
1126
1127 if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
1128 BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
1129 bch_cached_dev_run(dc);
1130
f59fce84 1131 return;
cafe5635 1132err:
cafe5635 1133 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
f59fce84 1134 bcache_device_stop(&dc->disk);
cafe5635
KO		 1135}
1136
1137/* Flash only volumes */
1138
1139void bch_flash_dev_release(struct kobject *kobj)
1140{
1141 struct bcache_device *d = container_of(kobj, struct bcache_device,
1142 kobj);
1143 kfree(d);
1144}
1145
1146static void flash_dev_free(struct closure *cl)
1147{
1148 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1149 bcache_device_free(d);
1150 kobject_put(&d->kobj);
1151}
1152
1153static void flash_dev_flush(struct closure *cl)
1154{
1155 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1156
ee668506 1157 bcache_device_unlink(d);
cafe5635
KO		 1158 kobject_del(&d->kobj);
1159 continue_at(cl, flash_dev_free, system_wq);
1160}
1161
1162static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
1163{
1164 struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
1165 GFP_KERNEL);
1166 if (!d)
1167 return -ENOMEM;
1168
1169 closure_init(&d->cl, NULL);
1170 set_closure_fn(&d->cl, flash_dev_flush, system_wq);
1171
1172 kobject_init(&d->kobj, &bch_flash_dev_ktype);
1173
279afbad 1174 if (bcache_device_init(d, block_bytes(c), u->sectors))
cafe5635
KO		 1175 goto err;
1176
1177 bcache_device_attach(d, c, u - c->uuids);
cafe5635
KO		 1178 bch_flash_dev_request_init(d);
1179 add_disk(d->disk);
1180
1181 if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache"))
1182 goto err;
1183
1184 bcache_device_link(d, c, "volume");
1185
1186 return 0;
1187err:
1188 kobject_put(&d->kobj);
1189 return -ENOMEM;
1190}
1191
1192static int flash_devs_run(struct cache_set *c)
1193{
1194 int ret = 0;
1195 struct uuid_entry *u;
1196
1197 for (u = c->uuids;
1198 u < c->uuids + c->nr_uuids && !ret;
1199 u++)
1200 if (UUID_FLASH_ONLY(u))
1201 ret = flash_dev_run(c, u);
1202
1203 return ret;
1204}
1205
1206int bch_flash_dev_create(struct cache_set *c, uint64_t size)
1207{
1208 struct uuid_entry *u;
1209
1210 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1211 return -EINTR;
1212
1213 u = uuid_find_empty(c);
1214 if (!u) {
1215 pr_err("Can't create volume, no room for UUID");
1216 return -EINVAL;
1217 }
1218
1219 get_random_bytes(u->uuid, 16);
1220 memset(u->label, 0, 32);
1221 u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
1222
1223 SET_UUID_FLASH_ONLY(u, 1);
1224 u->sectors = size >> 9;
1225
1226 bch_uuid_write(c);
1227
1228 return flash_dev_run(c, u);
1229}
1230
1231/* Cache set */
1232
1233__printf(2, 3)
1234bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
1235{
1236 va_list args;
1237
1238 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1239 return false;
1240
1241 /* XXX: we can be called from atomic context
1242 acquire_console_sem();
1243 */
1244
1245 printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid);
1246
1247 va_start(args, fmt);
1248 vprintk(fmt, args);
1249 va_end(args);
1250
1251 printk(", disabling caching\n");
1252
1253 bch_cache_set_unregister(c);
1254 return true;
1255}
1256
1257void bch_cache_set_release(struct kobject *kobj)
1258{
1259 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
1260 kfree(c);
1261 module_put(THIS_MODULE);
1262}
1263
1264static void cache_set_free(struct closure *cl)
1265{
1266 struct cache_set *c = container_of(cl, struct cache_set, cl);
1267 struct cache *ca;
1268 unsigned i;
1269
1270 if (!IS_ERR_OR_NULL(c->debug))
1271 debugfs_remove(c->debug);
1272
1273 bch_open_buckets_free(c);
1274 bch_btree_cache_free(c);
1275 bch_journal_free(c);
1276
1277 for_each_cache(ca, c, i)
1278 if (ca)
1279 kobject_put(&ca->kobj);
1280
1281 free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
1282 free_pages((unsigned long) c->sort, ilog2(bucket_pages(c)));
1283
cafe5635
KO		 1284 if (c->bio_split)
1285 bioset_free(c->bio_split);
57943511
KO		 1286 if (c->fill_iter)
1287 mempool_destroy(c->fill_iter);
cafe5635
KO		 1288 if (c->bio_meta)
1289 mempool_destroy(c->bio_meta);
1290 if (c->search)
1291 mempool_destroy(c->search);
1292 kfree(c->devices);
1293
1294 mutex_lock(&bch_register_lock);
1295 list_del(&c->list);
1296 mutex_unlock(&bch_register_lock);
1297
1298 pr_info("Cache set %pU unregistered", c->sb.set_uuid);
1299 wake_up(&unregister_wait);
1300
1301 closure_debug_destroy(&c->cl);
1302 kobject_put(&c->kobj);
1303}
1304
1305static void cache_set_flush(struct closure *cl)
1306{
1307 struct cache_set *c = container_of(cl, struct cache_set, caching);
1308 struct btree *b;
1309
1310 /* Shut down allocator threads */
1311 set_bit(CACHE_SET_STOPPING_2, &c->flags);
119ba0f8 1312 wake_up_allocators(c);
cafe5635
KO		 1313
1314 bch_cache_accounting_destroy(&c->accounting);
1315
1316 kobject_put(&c->internal);
1317 kobject_del(&c->kobj);
1318
1319 if (!IS_ERR_OR_NULL(c->root))
1320 list_add(&c->root->list, &c->btree_cache);
1321
1322 /* Should skip this if we're unregistering because of an error */
1323 list_for_each_entry(b, &c->btree_cache, list)
1324 if (btree_node_dirty(b))
57943511 1325 bch_btree_node_write(b, NULL);
cafe5635
KO		 1326
1327 closure_return(cl);
1328}
1329
1330static void __cache_set_unregister(struct closure *cl)
1331{
1332 struct cache_set *c = container_of(cl, struct cache_set, caching);
1333 struct cached_dev *dc, *t;
1334 size_t i;
1335
1336 mutex_lock(&bch_register_lock);
1337
1338 if (test_bit(CACHE_SET_UNREGISTERING, &c->flags))
1339 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1340 bch_cached_dev_detach(dc);
1341
1342 for (i = 0; i < c->nr_uuids; i++)
1343 if (c->devices[i] && UUID_FLASH_ONLY(&c->uuids[i]))
1344 bcache_device_stop(c->devices[i]);
1345
1346 mutex_unlock(&bch_register_lock);
1347
1348 continue_at(cl, cache_set_flush, system_wq);
1349}
1350
1351void bch_cache_set_stop(struct cache_set *c)
1352{
1353 if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
1354 closure_queue(&c->caching);
1355}
1356
1357void bch_cache_set_unregister(struct cache_set *c)
1358{
1359 set_bit(CACHE_SET_UNREGISTERING, &c->flags);
1360 bch_cache_set_stop(c);
1361}
1362
1363#define alloc_bucket_pages(gfp, c) \
1364 ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c))))
1365
1366struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1367{
1368 int iter_size;
1369 struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
1370 if (!c)
1371 return NULL;
1372
1373 __module_get(THIS_MODULE);
1374 closure_init(&c->cl, NULL);
1375 set_closure_fn(&c->cl, cache_set_free, system_wq);
1376
1377 closure_init(&c->caching, &c->cl);
1378 set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
1379
1380 /* Maybe create continue_at_noreturn() and use it here? */
1381 closure_set_stopped(&c->cl);
1382 closure_put(&c->cl);
1383
1384 kobject_init(&c->kobj, &bch_cache_set_ktype);
1385 kobject_init(&c->internal, &bch_cache_set_internal_ktype);
1386
1387 bch_cache_accounting_init(&c->accounting, &c->cl);
1388
1389 memcpy(c->sb.set_uuid, sb->set_uuid, 16);
1390 c->sb.block_size = sb->block_size;
1391 c->sb.bucket_size = sb->bucket_size;
1392 c->sb.nr_in_set = sb->nr_in_set;
1393 c->sb.last_mount = sb->last_mount;
1394 c->bucket_bits = ilog2(sb->bucket_size);
1395 c->block_bits = ilog2(sb->block_size);
1396 c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
1397
1398 c->btree_pages = c->sb.bucket_size / PAGE_SECTORS;
1399 if (c->btree_pages > BTREE_MAX_PAGES)
1400 c->btree_pages = max_t(int, c->btree_pages / 4,
1401 BTREE_MAX_PAGES);
1402
6ded34d1
KO		 1403 c->sort_crit_factor = int_sqrt(c->btree_pages);
1404
cafe5635 1405 mutex_init(&c->bucket_lock);
cafe5635
KO		 1406 mutex_init(&c->sort_lock);
1407 spin_lock_init(&c->sort_time_lock);
1408 closure_init_unlocked(&c->sb_write);
1409 closure_init_unlocked(&c->uuid_write);
1410 spin_lock_init(&c->btree_read_time_lock);
1411 bch_moving_init_cache_set(c);
1412
1413 INIT_LIST_HEAD(&c->list);
1414 INIT_LIST_HEAD(&c->cached_devs);
1415 INIT_LIST_HEAD(&c->btree_cache);
1416 INIT_LIST_HEAD(&c->btree_cache_freeable);
1417 INIT_LIST_HEAD(&c->btree_cache_freed);
1418 INIT_LIST_HEAD(&c->data_buckets);
1419
1420 c->search = mempool_create_slab_pool(32, bch_search_cache);
1421 if (!c->search)
1422 goto err;
1423
1424 iter_size = (sb->bucket_size / sb->block_size + 1) *
1425 sizeof(struct btree_iter_set);
1426
1427 if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) ||
1428 !(c->bio_meta = mempool_create_kmalloc_pool(2,
1429 sizeof(struct bbio) + sizeof(struct bio_vec) *
1430 bucket_pages(c))) ||
57943511 1431 !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
cafe5635 1432 !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
cafe5635
KO		 1433 !(c->sort = alloc_bucket_pages(GFP_KERNEL, c)) ||
1434 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1435 bch_journal_alloc(c) ||
1436 bch_btree_cache_alloc(c) ||
1437 bch_open_buckets_alloc(c))
1438 goto err;
1439
cafe5635
KO		 1440 c->congested_read_threshold_us = 2000;
1441 c->congested_write_threshold_us = 20000;
1442 c->error_limit = 8 << IO_ERROR_SHIFT;
1443
1444 return c;
1445err:
1446 bch_cache_set_unregister(c);
1447 return NULL;
1448}
1449
1450static void run_cache_set(struct cache_set *c)
1451{
1452 const char *err = "cannot allocate memory";
1453 struct cached_dev *dc, *t;
1454 struct cache *ca;
1455 unsigned i;
1456
1457 struct btree_op op;
1458 bch_btree_op_init_stack(&op);
1459 op.lock = SHRT_MAX;
1460
1461 for_each_cache(ca, c, i)
1462 c->nbuckets += ca->sb.nbuckets;
1463
1464 if (CACHE_SYNC(&c->sb)) {
1465 LIST_HEAD(journal);
1466 struct bkey *k;
1467 struct jset *j;
1468
1469 err = "cannot allocate memory for journal";
1470 if (bch_journal_read(c, &journal, &op))
1471 goto err;
1472
1473 pr_debug("btree_journal_read() done");
1474
1475 err = "no journal entries found";
1476 if (list_empty(&journal))
1477 goto err;
1478
1479 j = &list_entry(journal.prev, struct journal_replay, list)->j;
1480
1481 err = "IO error reading priorities";
1482 for_each_cache(ca, c, i)
1483 prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]);
1484
1485 /*
1486 * If prio_read() fails it'll call cache_set_error and we'll
1487 * tear everything down right away, but if we perhaps checked
1488 * sooner we could avoid journal replay.
1489 */
1490
1491 k = &j->btree_root;
1492
1493 err = "bad btree root";
1494 if (__bch_ptr_invalid(c, j->btree_level + 1, k))
1495 goto err;
1496
1497 err = "error reading btree root";
1498 c->root = bch_btree_node_get(c, k, j->btree_level, &op);
1499 if (IS_ERR_OR_NULL(c->root))
1500 goto err;
1501
1502 list_del_init(&c->root->list);
1503 rw_unlock(true, c->root);
1504
1505 err = uuid_read(c, j, &op.cl);
1506 if (err)
1507 goto err;
1508
1509 err = "error in recovery";
1510 if (bch_btree_check(c, &op))
1511 goto err;
1512
1513 bch_journal_mark(c, &journal);
1514 bch_btree_gc_finish(c);
1515 pr_debug("btree_check() done");
1516
1517 /*
1518 * bcache_journal_next() can't happen sooner, or
1519 * btree_gc_finish() will give spurious errors about last_gc >
1520 * gc_gen - this is a hack but oh well.
1521 */
1522 bch_journal_next(&c->journal);
1523
119ba0f8 1524 err = "error starting allocator thread";
cafe5635 1525 for_each_cache(ca, c, i)
119ba0f8
KO		 1526 if (bch_cache_allocator_start(ca))
1527 goto err;
cafe5635
KO		 1528
1529 /*
1530 * First place it's safe to allocate: btree_check() and
1531 * btree_gc_finish() have to run before we have buckets to
1532 * allocate, and bch_bucket_alloc_set() might cause a journal
1533 * entry to be written so bcache_journal_next() has to be called
1534 * first.
1535 *
1536 * If the uuids were in the old format we have to rewrite them
1537 * before the next journal entry is written:
1538 */
1539 if (j->version < BCACHE_JSET_VERSION_UUID)
1540 __uuid_write(c);
1541
1542 bch_journal_replay(c, &journal, &op);
1543 } else {
1544 pr_notice("invalidating existing data");
1545 /* Don't want invalidate_buckets() to queue a gc yet */
1546 closure_lock(&c->gc, NULL);
1547
1548 for_each_cache(ca, c, i) {
1549 unsigned j;
1550
1551 ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
1552 2, SB_JOURNAL_BUCKETS);
1553
1554 for (j = 0; j < ca->sb.keys; j++)
1555 ca->sb.d[j] = ca->sb.first_bucket + j;
1556 }
1557
1558 bch_btree_gc_finish(c);
1559
119ba0f8 1560 err = "error starting allocator thread";
cafe5635 1561 for_each_cache(ca, c, i)
119ba0f8
KO		 1562 if (bch_cache_allocator_start(ca))
1563 goto err;
cafe5635
KO		 1564
1565 mutex_lock(&c->bucket_lock);
1566 for_each_cache(ca, c, i)
1567 bch_prio_write(ca);
1568 mutex_unlock(&c->bucket_lock);
1569
cafe5635
KO		 1570 err = "cannot allocate new UUID bucket";
1571 if (__uuid_write(c))
1572 goto err_unlock_gc;
1573
1574 err = "cannot allocate new btree root";
1575 c->root = bch_btree_node_alloc(c, 0, &op.cl);
1576 if (IS_ERR_OR_NULL(c->root))
1577 goto err_unlock_gc;
1578
1579 bkey_copy_key(&c->root->key, &MAX_KEY);
57943511 1580 bch_btree_node_write(c->root, &op.cl);
cafe5635
KO		 1581
1582 bch_btree_set_root(c->root);
1583 rw_unlock(true, c->root);
1584
1585 /*
1586 * We don't want to write the first journal entry until
1587 * everything is set up - fortunately journal entries won't be
1588 * written until the SET_CACHE_SYNC() here:
1589 */
1590 SET_CACHE_SYNC(&c->sb, true);
1591
1592 bch_journal_next(&c->journal);
1593 bch_journal_meta(c, &op.cl);
1594
1595 /* Unlock */
1596 closure_set_stopped(&c->gc.cl);
1597 closure_put(&c->gc.cl);
1598 }
1599
1600 closure_sync(&op.cl);
1601 c->sb.last_mount = get_seconds();
1602 bcache_write_super(c);
1603
1604 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1605 bch_cached_dev_attach(dc, c);
1606
1607 flash_devs_run(c);
1608
1609 return;
1610err_unlock_gc:
1611 closure_set_stopped(&c->gc.cl);
1612 closure_put(&c->gc.cl);
1613err:
1614 closure_sync(&op.cl);
1615 /* XXX: test this, it's broken */
1616 bch_cache_set_error(c, err);
1617}
1618
1619static bool can_attach_cache(struct cache *ca, struct cache_set *c)
1620{
1621 return ca->sb.block_size == c->sb.block_size &&
1622 ca->sb.bucket_size == c->sb.block_size &&
1623 ca->sb.nr_in_set == c->sb.nr_in_set;
1624}
1625
1626static const char *register_cache_set(struct cache *ca)
1627{
1628 char buf[12];
1629 const char *err = "cannot allocate memory";
1630 struct cache_set *c;
1631
1632 list_for_each_entry(c, &bch_cache_sets, list)
1633 if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
1634 if (c->cache[ca->sb.nr_this_dev])
1635 return "duplicate cache set member";
1636
1637 if (!can_attach_cache(ca, c))
1638 return "cache sb does not match set";
1639
1640 if (!CACHE_SYNC(&ca->sb))
1641 SET_CACHE_SYNC(&c->sb, false);
1642
1643 goto found;
1644 }
1645
1646 c = bch_cache_set_alloc(&ca->sb);
1647 if (!c)
1648 return err;
1649
1650 err = "error creating kobject";
1651 if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
1652 kobject_add(&c->internal, &c->kobj, "internal"))
1653 goto err;
1654
1655 if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
1656 goto err;
1657
1658 bch_debug_init_cache_set(c);
1659
1660 list_add(&c->list, &bch_cache_sets);
1661found:
1662 sprintf(buf, "cache%i", ca->sb.nr_this_dev);
1663 if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
1664 sysfs_create_link(&c->kobj, &ca->kobj, buf))
1665 goto err;
1666
1667 if (ca->sb.seq > c->sb.seq) {
1668 c->sb.version = ca->sb.version;
1669 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
1670 c->sb.flags = ca->sb.flags;
1671 c->sb.seq = ca->sb.seq;
1672 pr_debug("set version = %llu", c->sb.version);
1673 }
1674
1675 ca->set = c;
1676 ca->set->cache[ca->sb.nr_this_dev] = ca;
1677 c->cache_by_alloc[c->caches_loaded++] = ca;
1678
1679 if (c->caches_loaded == c->sb.nr_in_set)
1680 run_cache_set(c);
1681
1682 return NULL;
1683err:
1684 bch_cache_set_unregister(c);
1685 return err;
1686}
1687
1688/* Cache device */
1689
1690void bch_cache_release(struct kobject *kobj)
1691{
1692 struct cache *ca = container_of(kobj, struct cache, kobj);
1693
1694 if (ca->set)
1695 ca->set->cache[ca->sb.nr_this_dev] = NULL;
1696
1697 bch_cache_allocator_exit(ca);
1698
1699 bio_split_pool_free(&ca->bio_split_hook);
1700
cafe5635
KO		 1701 free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
1702 kfree(ca->prio_buckets);
1703 vfree(ca->buckets);
1704
1705 free_heap(&ca->heap);
1706 free_fifo(&ca->unused);
1707 free_fifo(&ca->free_inc);
1708 free_fifo(&ca->free);
1709
1710 if (ca->sb_bio.bi_inline_vecs[0].bv_page)
1711 put_page(ca->sb_bio.bi_io_vec[0].bv_page);
1712
1713 if (!IS_ERR_OR_NULL(ca->bdev)) {
1714 blk_sync_queue(bdev_get_queue(ca->bdev));
1715 blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1716 }
1717
1718 kfree(ca);
1719 module_put(THIS_MODULE);
1720}
1721
1722static int cache_alloc(struct cache_sb *sb, struct cache *ca)
1723{
1724 size_t free;
1725 struct bucket *b;
1726
cafe5635
KO		 1727 __module_get(THIS_MODULE);
1728 kobject_init(&ca->kobj, &bch_cache_ktype);
1729
cafe5635
KO		 1730 INIT_LIST_HEAD(&ca->discards);
1731
cafe5635
KO		 1732 bio_init(&ca->journal.bio);
1733 ca->journal.bio.bi_max_vecs = 8;
1734 ca->journal.bio.bi_io_vec = ca->journal.bio.bi_inline_vecs;
1735
1736 free = roundup_pow_of_two(ca->sb.nbuckets) >> 9;
1737 free = max_t(size_t, free, (prio_buckets(ca) + 8) * 2);
1738
1739 if (!init_fifo(&ca->free, free, GFP_KERNEL) ||
1740 !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
1741 !init_fifo(&ca->unused, free << 2, GFP_KERNEL) ||
1742 !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
f59fce84 1743 !(ca->buckets = vzalloc(sizeof(struct bucket) *
cafe5635
KO		 1744 ca->sb.nbuckets)) ||
1745 !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
1746 2, GFP_KERNEL)) ||
1747 !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)) ||
cafe5635 1748 bio_split_pool_init(&ca->bio_split_hook))
f59fce84 1749 return -ENOMEM;
cafe5635
KO		 1750
1751 ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
1752
cafe5635
KO		 1753 for_each_bucket(b, ca)
1754 atomic_set(&b->pin, 0);
1755
1756 if (bch_cache_allocator_init(ca))
1757 goto err;
1758
1759 return 0;
1760err:
1761 kobject_put(&ca->kobj);
1762 return -ENOMEM;
1763}
1764
f59fce84 1765static void register_cache(struct cache_sb *sb, struct page *sb_page,
cafe5635
KO		 1766 struct block_device *bdev, struct cache *ca)
1767{
1768 char name[BDEVNAME_SIZE];
1769 const char *err = "cannot allocate memory";
1770
f59fce84 1771 memcpy(&ca->sb, sb, sizeof(struct cache_sb));
cafe5635
KO		 1772 ca->bdev = bdev;
1773 ca->bdev->bd_holder = ca;
1774
f59fce84
KO		 1775 bio_init(&ca->sb_bio);
1776 ca->sb_bio.bi_max_vecs = 1;
1777 ca->sb_bio.bi_io_vec = ca->sb_bio.bi_inline_vecs;
1778 ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
1779 get_page(sb_page);
1780
cafe5635
KO		 1781 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1782 ca->discard = CACHE_DISCARD(&ca->sb);
1783
f59fce84
KO		 1784 if (cache_alloc(sb, ca) != 0)
1785 goto err;
1786
cafe5635
KO		 1787 err = "error creating kobject";
1788 if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache"))
1789 goto err;
1790
1791 err = register_cache_set(ca);
1792 if (err)
1793 goto err;
1794
1795 pr_info("registered cache device %s", bdevname(bdev, name));
f59fce84 1796 return;
cafe5635 1797err:
f59fce84 1798 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
cafe5635 1799 kobject_put(&ca->kobj);
cafe5635
KO		 1800}
1801
1802/* Global interfaces/init */
1803
1804static ssize_t register_bcache(struct kobject *, struct kobj_attribute *,
1805 const char *, size_t);
1806
1807kobj_attribute_write(register, register_bcache);
1808kobj_attribute_write(register_quiet, register_bcache);
1809
a9dd53ad
GP		 1810static bool bch_is_open_backing(struct block_device *bdev) {
1811 struct cache_set *c, *tc;
1812 struct cached_dev *dc, *t;
1813
1814 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1815 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1816 if (dc->bdev == bdev)
1817 return true;
1818 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1819 if (dc->bdev == bdev)
1820 return true;
1821 return false;
1822}
1823
1824static bool bch_is_open_cache(struct block_device *bdev) {
1825 struct cache_set *c, *tc;
1826 struct cache *ca;
1827 unsigned i;
1828
1829 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1830 for_each_cache(ca, c, i)
1831 if (ca->bdev == bdev)
1832 return true;
1833 return false;
1834}
1835
1836static bool bch_is_open(struct block_device *bdev) {
1837 return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
1838}
1839
cafe5635
KO		 1840static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
1841 const char *buffer, size_t size)
1842{
1843 ssize_t ret = size;
1844 const char *err = "cannot allocate memory";
1845 char *path = NULL;
1846 struct cache_sb *sb = NULL;
1847 struct block_device *bdev = NULL;
1848 struct page *sb_page = NULL;
1849
1850 if (!try_module_get(THIS_MODULE))
1851 return -EBUSY;
1852
1853 mutex_lock(&bch_register_lock);
1854
1855 if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
1856 !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
1857 goto err;
1858
1859 err = "failed to open device";
1860 bdev = blkdev_get_by_path(strim(path),
1861 FMODE_READ|FMODE_WRITE|FMODE_EXCL,
1862 sb);
f59fce84 1863 if (IS_ERR(bdev)) {
a9dd53ad
GP		 1864 if (bdev == ERR_PTR(-EBUSY)) {
1865 bdev = lookup_bdev(strim(path));
1866 if (!IS_ERR(bdev) && bch_is_open(bdev))
1867 err = "device already registered";
1868 else
1869 err = "device busy";
1870 }
cafe5635 1871 goto err;
f59fce84
KO		 1872 }
1873
1874 err = "failed to set blocksize";
1875 if (set_blocksize(bdev, 4096))
1876 goto err_close;
cafe5635
KO		 1877
1878 err = read_super(sb, bdev, &sb_page);
1879 if (err)
1880 goto err_close;
1881
2903381f 1882 if (SB_IS_BDEV(sb)) {
cafe5635 1883 struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
f59fce84
KO		 1884 if (!dc)
1885 goto err_close;
cafe5635 1886
f59fce84 1887 register_bdev(sb, sb_page, bdev, dc);
cafe5635
KO		 1888 } else {
1889 struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
f59fce84
KO		 1890 if (!ca)
1891 goto err_close;
cafe5635 1892
f59fce84 1893 register_cache(sb, sb_page, bdev, ca);
cafe5635 1894 }
f59fce84
KO		 1895out:
1896 if (sb_page)
cafe5635 1897 put_page(sb_page);
cafe5635
KO		 1898 kfree(sb);
1899 kfree(path);
1900 mutex_unlock(&bch_register_lock);
1901 module_put(THIS_MODULE);
1902 return ret;
f59fce84
KO		 1903
1904err_close:
1905 blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1906err:
1907 if (attr != &ksysfs_register_quiet)
1908 pr_info("error opening %s: %s", path, err);
1909 ret = -EINVAL;
1910 goto out;
cafe5635
KO		 1911}
1912
1913static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
1914{
1915 if (code == SYS_DOWN ||
1916 code == SYS_HALT ||
1917 code == SYS_POWER_OFF) {
1918 DEFINE_WAIT(wait);
1919 unsigned long start = jiffies;
1920 bool stopped = false;
1921
1922 struct cache_set *c, *tc;
1923 struct cached_dev *dc, *tdc;
1924
1925 mutex_lock(&bch_register_lock);
1926
1927 if (list_empty(&bch_cache_sets) &&
1928 list_empty(&uncached_devices))
1929 goto out;
1930
1931 pr_info("Stopping all devices:");
1932
1933 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1934 bch_cache_set_stop(c);
1935
1936 list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
1937 bcache_device_stop(&dc->disk);
1938
1939 /* What's a condition variable? */
1940 while (1) {
1941 long timeout = start + 2 * HZ - jiffies;
1942
1943 stopped = list_empty(&bch_cache_sets) &&
1944 list_empty(&uncached_devices);
1945
1946 if (timeout < 0 || stopped)
1947 break;
1948
1949 prepare_to_wait(&unregister_wait, &wait,
1950 TASK_UNINTERRUPTIBLE);
1951
1952 mutex_unlock(&bch_register_lock);
1953 schedule_timeout(timeout);
1954 mutex_lock(&bch_register_lock);
1955 }
1956
1957 finish_wait(&unregister_wait, &wait);
1958
1959 if (stopped)
1960 pr_info("All devices stopped");
1961 else
1962 pr_notice("Timeout waiting for devices to be closed");
1963out:
1964 mutex_unlock(&bch_register_lock);
1965 }
1966
1967 return NOTIFY_DONE;
1968}
1969
1970static struct notifier_block reboot = {
1971 .notifier_call = bcache_reboot,
1972 .priority = INT_MAX, /* before any real devices */
1973};
1974
1975static void bcache_exit(void)
1976{
1977 bch_debug_exit();
1978 bch_writeback_exit();
1979 bch_request_exit();
1980 bch_btree_exit();
1981 if (bcache_kobj)
1982 kobject_put(bcache_kobj);
1983 if (bcache_wq)
1984 destroy_workqueue(bcache_wq);
1985 unregister_blkdev(bcache_major, "bcache");
1986 unregister_reboot_notifier(&reboot);
1987}
1988
1989static int __init bcache_init(void)
1990{
1991 static const struct attribute *files[] = {
1992 &ksysfs_register.attr,
1993 &ksysfs_register_quiet.attr,
1994 NULL
1995 };
1996
1997 mutex_init(&bch_register_lock);
1998 init_waitqueue_head(&unregister_wait);
1999 register_reboot_notifier(&reboot);
07e86ccb 2000 closure_debug_init();
cafe5635
KO		 2001
2002 bcache_major = register_blkdev(0, "bcache");
2003 if (bcache_major < 0)
2004 return bcache_major;
2005
2006 if (!(bcache_wq = create_workqueue("bcache")) ||
2007 !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
2008 sysfs_create_files(bcache_kobj, files) ||
2009 bch_btree_init() ||
2010 bch_request_init() ||
2011 bch_writeback_init() ||
2012 bch_debug_init(bcache_kobj))
2013 goto err;
2014
2015 return 0;
2016err:
2017 bcache_exit();
2018 return -ENOMEM;
2019}
2020
2021module_exit(bcache_exit);
2022module_init(bcache_init);
Linux kernel - Deliverables
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