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xtensa: support DMA buffers in high memory
[cris-mirror.git] / drivers / md / bcache / super.c
blob312895788036705cb0426d1af5b5662a4797faf3
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_device_idx);
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 /* limitation of partitions number on single bcache device */
62 #define BCACHE_MINORS 128
63 /* limitation of bcache devices number on single system */
64 #define BCACHE_DEVICE_IDX_MAX ((1U << MINORBITS)/BCACHE_MINORS)
65
66 /* Superblock */
67
68 static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
69 struct page **res)
70 {
71 const char *err;
72 struct cache_sb *s;
73 struct buffer_head *bh = __bread(bdev, 1, SB_SIZE);
74 unsigned i;
75
76 if (!bh)
77 return "IO error";
78
79 s = (struct cache_sb *) bh->b_data;
80
81 sb->offset = le64_to_cpu(s->offset);
82 sb->version = le64_to_cpu(s->version);
83
84 memcpy(sb->magic, s->magic, 16);
85 memcpy(sb->uuid, s->uuid, 16);
86 memcpy(sb->set_uuid, s->set_uuid, 16);
87 memcpy(sb->label, s->label, SB_LABEL_SIZE);
88
89 sb->flags = le64_to_cpu(s->flags);
90 sb->seq = le64_to_cpu(s->seq);
91 sb->last_mount = le32_to_cpu(s->last_mount);
92 sb->first_bucket = le16_to_cpu(s->first_bucket);
93 sb->keys = le16_to_cpu(s->keys);
94
95 for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
96 sb->d[i] = le64_to_cpu(s->d[i]);
97
98 pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
99 sb->version, sb->flags, sb->seq, sb->keys);
100
101 err = "Not a bcache superblock";
102 if (sb->offset != SB_SECTOR)
103 goto err;
104
105 if (memcmp(sb->magic, bcache_magic, 16))
106 goto err;
107
108 err = "Too many journal buckets";
109 if (sb->keys > SB_JOURNAL_BUCKETS)
110 goto err;
111
112 err = "Bad checksum";
113 if (s->csum != csum_set(s))
114 goto err;
115
116 err = "Bad UUID";
117 if (bch_is_zero(sb->uuid, 16))
118 goto err;
119
120 sb->block_size = le16_to_cpu(s->block_size);
121
122 err = "Superblock block size smaller than device block size";
123 if (sb->block_size << 9 < bdev_logical_block_size(bdev))
124 goto err;
125
126 switch (sb->version) {
127 case BCACHE_SB_VERSION_BDEV:
128 sb->data_offset = BDEV_DATA_START_DEFAULT;
129 break;
130 case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
131 sb->data_offset = le64_to_cpu(s->data_offset);
132
133 err = "Bad data offset";
134 if (sb->data_offset < BDEV_DATA_START_DEFAULT)
135 goto err;
136
137 break;
138 case BCACHE_SB_VERSION_CDEV:
139 case BCACHE_SB_VERSION_CDEV_WITH_UUID:
140 sb->nbuckets = le64_to_cpu(s->nbuckets);
141 sb->bucket_size = le16_to_cpu(s->bucket_size);
142
143 sb->nr_in_set = le16_to_cpu(s->nr_in_set);
144 sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
145
146 err = "Too many buckets";
147 if (sb->nbuckets > LONG_MAX)
148 goto err;
149
150 err = "Not enough buckets";
151 if (sb->nbuckets < 1 << 7)
152 goto err;
153
154 err = "Bad block/bucket size";
155 if (!is_power_of_2(sb->block_size) ||
156 sb->block_size > PAGE_SECTORS ||
157 !is_power_of_2(sb->bucket_size) ||
158 sb->bucket_size < PAGE_SECTORS)
159 goto err;
160
161 err = "Invalid superblock: device too small";
162 if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
163 goto err;
164
165 err = "Bad UUID";
166 if (bch_is_zero(sb->set_uuid, 16))
167 goto err;
168
169 err = "Bad cache device number in set";
170 if (!sb->nr_in_set ||
171 sb->nr_in_set <= sb->nr_this_dev ||
172 sb->nr_in_set > MAX_CACHES_PER_SET)
173 goto err;
174
175 err = "Journal buckets not sequential";
176 for (i = 0; i < sb->keys; i++)
177 if (sb->d[i] != sb->first_bucket + i)
178 goto err;
179
180 err = "Too many journal buckets";
181 if (sb->first_bucket + sb->keys > sb->nbuckets)
182 goto err;
183
184 err = "Invalid superblock: first bucket comes before end of super";
185 if (sb->first_bucket * sb->bucket_size < 16)
186 goto err;
187
188 break;
189 default:
190 err = "Unsupported superblock version";
191 goto err;
192 }
193
194 sb->last_mount = get_seconds();
195 err = NULL;
196
197 get_page(bh->b_page);
198 *res = bh->b_page;
199 err:
200 put_bh(bh);
201 return err;
202 }
203
204 static void write_bdev_super_endio(struct bio *bio)
205 {
206 struct cached_dev *dc = bio->bi_private;
207 /* XXX: error checking */
208
209 closure_put(&dc->sb_write);
210 }
211
212 static void __write_super(struct cache_sb *sb, struct bio *bio)
213 {
214 struct cache_sb *out = page_address(bio_first_page_all(bio));
215 unsigned i;
216
217 bio->bi_iter.bi_sector = SB_SECTOR;
218 bio->bi_iter.bi_size = SB_SIZE;
219 bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_SYNC|REQ_META);
220 bch_bio_map(bio, NULL);
221
222 out->offset = cpu_to_le64(sb->offset);
223 out->version = cpu_to_le64(sb->version);
224
225 memcpy(out->uuid, sb->uuid, 16);
226 memcpy(out->set_uuid, sb->set_uuid, 16);
227 memcpy(out->label, sb->label, SB_LABEL_SIZE);
228
229 out->flags = cpu_to_le64(sb->flags);
230 out->seq = cpu_to_le64(sb->seq);
231
232 out->last_mount = cpu_to_le32(sb->last_mount);
233 out->first_bucket = cpu_to_le16(sb->first_bucket);
234 out->keys = cpu_to_le16(sb->keys);
235
236 for (i = 0; i < sb->keys; i++)
237 out->d[i] = cpu_to_le64(sb->d[i]);
238
239 out->csum = csum_set(out);
240
241 pr_debug("ver %llu, flags %llu, seq %llu",
242 sb->version, sb->flags, sb->seq);
243
244 submit_bio(bio);
245 }
246
247 static void bch_write_bdev_super_unlock(struct closure *cl)
248 {
249 struct cached_dev *dc = container_of(cl, struct cached_dev, sb_write);
250
251 up(&dc->sb_write_mutex);
252 }
253
254 void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
255 {
256 struct closure *cl = &dc->sb_write;
257 struct bio *bio = &dc->sb_bio;
258
259 down(&dc->sb_write_mutex);
260 closure_init(cl, parent);
261
262 bio_reset(bio);
263 bio_set_dev(bio, dc->bdev);
264 bio->bi_end_io = write_bdev_super_endio;
265 bio->bi_private = dc;
266
267 closure_get(cl);
268 __write_super(&dc->sb, bio);
269
270 closure_return_with_destructor(cl, bch_write_bdev_super_unlock);
271 }
272
273 static void write_super_endio(struct bio *bio)
274 {
275 struct cache *ca = bio->bi_private;
276
277 /* is_read = 0 */
278 bch_count_io_errors(ca, bio->bi_status, 0,
279 "writing superblock");
280 closure_put(&ca->set->sb_write);
281 }
282
283 static void bcache_write_super_unlock(struct closure *cl)
284 {
285 struct cache_set *c = container_of(cl, struct cache_set, sb_write);
286
287 up(&c->sb_write_mutex);
288 }
289
290 void bcache_write_super(struct cache_set *c)
291 {
292 struct closure *cl = &c->sb_write;
293 struct cache *ca;
294 unsigned i;
295
296 down(&c->sb_write_mutex);
297 closure_init(cl, &c->cl);
298
299 c->sb.seq++;
300
301 for_each_cache(ca, c, i) {
302 struct bio *bio = &ca->sb_bio;
303
304 ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
305 ca->sb.seq = c->sb.seq;
306 ca->sb.last_mount = c->sb.last_mount;
307
308 SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb));
309
310 bio_reset(bio);
311 bio_set_dev(bio, ca->bdev);
312 bio->bi_end_io = write_super_endio;
313 bio->bi_private = ca;
314
315 closure_get(cl);
316 __write_super(&ca->sb, bio);
317 }
318
319 closure_return_with_destructor(cl, bcache_write_super_unlock);
320 }
321
322 /* UUID io */
323
324 static void uuid_endio(struct bio *bio)
325 {
326 struct closure *cl = bio->bi_private;
327 struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
328
329 cache_set_err_on(bio->bi_status, c, "accessing uuids");
330 bch_bbio_free(bio, c);
331 closure_put(cl);
332 }
333
334 static void uuid_io_unlock(struct closure *cl)
335 {
336 struct cache_set *c = container_of(cl, struct cache_set, uuid_write);
337
338 up(&c->uuid_write_mutex);
339 }
340
341 static void uuid_io(struct cache_set *c, int op, unsigned long op_flags,
342 struct bkey *k, struct closure *parent)
343 {
344 struct closure *cl = &c->uuid_write;
345 struct uuid_entry *u;
346 unsigned i;
347 char buf[80];
348
349 BUG_ON(!parent);
350 down(&c->uuid_write_mutex);
351 closure_init(cl, parent);
352
353 for (i = 0; i < KEY_PTRS(k); i++) {
354 struct bio *bio = bch_bbio_alloc(c);
355
356 bio->bi_opf = REQ_SYNC | REQ_META | op_flags;
357 bio->bi_iter.bi_size = KEY_SIZE(k) << 9;
358
359 bio->bi_end_io = uuid_endio;
360 bio->bi_private = cl;
361 bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags);
362 bch_bio_map(bio, c->uuids);
363
364 bch_submit_bbio(bio, c, k, i);
365
366 if (op != REQ_OP_WRITE)
367 break;
368 }
369
370 bch_extent_to_text(buf, sizeof(buf), k);
371 pr_debug("%s UUIDs at %s", op == REQ_OP_WRITE ? "wrote" : "read", buf);
372
373 for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
374 if (!bch_is_zero(u->uuid, 16))
375 pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
376 u - c->uuids, u->uuid, u->label,
377 u->first_reg, u->last_reg, u->invalidated);
378
379 closure_return_with_destructor(cl, uuid_io_unlock);
380 }
381
382 static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
383 {
384 struct bkey *k = &j->uuid_bucket;
385
386 if (__bch_btree_ptr_invalid(c, k))
387 return "bad uuid pointer";
388
389 bkey_copy(&c->uuid_bucket, k);
390 uuid_io(c, REQ_OP_READ, 0, k, cl);
391
392 if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
393 struct uuid_entry_v0 *u0 = (void *) c->uuids;
394 struct uuid_entry *u1 = (void *) c->uuids;
395 int i;
396
397 closure_sync(cl);
398
399 /*
400 * Since the new uuid entry is bigger than the old, we have to
401 * convert starting at the highest memory address and work down
402 * in order to do it in place
403 */
404
405 for (i = c->nr_uuids - 1;
406 i >= 0;
407 --i) {
408 memcpy(u1[i].uuid, u0[i].uuid, 16);
409 memcpy(u1[i].label, u0[i].label, 32);
410
411 u1[i].first_reg = u0[i].first_reg;
412 u1[i].last_reg = u0[i].last_reg;
413 u1[i].invalidated = u0[i].invalidated;
414
415 u1[i].flags = 0;
416 u1[i].sectors = 0;
417 }
418 }
419
420 return NULL;
421 }
422
423 static int __uuid_write(struct cache_set *c)
424 {
425 BKEY_PADDED(key) k;
426 struct closure cl;
427 closure_init_stack(&cl);
428
429 lockdep_assert_held(&bch_register_lock);
430
431 if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true))
432 return 1;
433
434 SET_KEY_SIZE(&k.key, c->sb.bucket_size);
435 uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl);
436 closure_sync(&cl);
437
438 bkey_copy(&c->uuid_bucket, &k.key);
439 bkey_put(c, &k.key);
440 return 0;
441 }
442
443 int bch_uuid_write(struct cache_set *c)
444 {
445 int ret = __uuid_write(c);
446
447 if (!ret)
448 bch_journal_meta(c, NULL);
449
450 return ret;
451 }
452
453 static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
454 {
455 struct uuid_entry *u;
456
457 for (u = c->uuids;
458 u < c->uuids + c->nr_uuids; u++)
459 if (!memcmp(u->uuid, uuid, 16))
460 return u;
461
462 return NULL;
463 }
464
465 static struct uuid_entry *uuid_find_empty(struct cache_set *c)
466 {
467 static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
468 return uuid_find(c, zero_uuid);
469 }
470
471 /*
472 * Bucket priorities/gens:
473 *
474 * For each bucket, we store on disk its
475 * 8 bit gen
476 * 16 bit priority
477 *
478 * See alloc.c for an explanation of the gen. The priority is used to implement
479 * lru (and in the future other) cache replacement policies; for most purposes
480 * it's just an opaque integer.
481 *
482 * The gens and the priorities don't have a whole lot to do with each other, and
483 * it's actually the gens that must be written out at specific times - it's no
484 * big deal if the priorities don't get written, if we lose them we just reuse
485 * buckets in suboptimal order.
486 *
487 * On disk they're stored in a packed array, and in as many buckets are required
488 * to fit them all. The buckets we use to store them form a list; the journal
489 * header points to the first bucket, the first bucket points to the second
490 * bucket, et cetera.
491 *
492 * This code is used by the allocation code; periodically (whenever it runs out
493 * of buckets to allocate from) the allocation code will invalidate some
494 * buckets, but it can't use those buckets until their new gens are safely on
495 * disk.
496 */
497
498 static void prio_endio(struct bio *bio)
499 {
500 struct cache *ca = bio->bi_private;
501
502 cache_set_err_on(bio->bi_status, ca->set, "accessing priorities");
503 bch_bbio_free(bio, ca->set);
504 closure_put(&ca->prio);
505 }
506
507 static void prio_io(struct cache *ca, uint64_t bucket, int op,
508 unsigned long op_flags)
509 {
510 struct closure *cl = &ca->prio;
511 struct bio *bio = bch_bbio_alloc(ca->set);
512
513 closure_init_stack(cl);
514
515 bio->bi_iter.bi_sector = bucket * ca->sb.bucket_size;
516 bio_set_dev(bio, ca->bdev);
517 bio->bi_iter.bi_size = bucket_bytes(ca);
518
519 bio->bi_end_io = prio_endio;
520 bio->bi_private = ca;
521 bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags);
522 bch_bio_map(bio, ca->disk_buckets);
523
524 closure_bio_submit(bio, &ca->prio);
525 closure_sync(cl);
526 }
527
528 void 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 ca->disk_buckets->seq++;
539
540 atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
541 &ca->meta_sectors_written);
542
543 //pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free),
544 // fifo_used(&ca->free_inc), fifo_used(&ca->unused));
545
546 for (i = prio_buckets(ca) - 1; i >= 0; --i) {
547 long bucket;
548 struct prio_set *p = ca->disk_buckets;
549 struct bucket_disk *d = p->data;
550 struct bucket_disk *end = d + prios_per_bucket(ca);
551
552 for (b = ca->buckets + i * prios_per_bucket(ca);
553 b < ca->buckets + ca->sb.nbuckets && d < end;
554 b++, d++) {
555 d->prio = cpu_to_le16(b->prio);
556 d->gen = b->gen;
557 }
558
559 p->next_bucket = ca->prio_buckets[i + 1];
560 p->magic = pset_magic(&ca->sb);
561 p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8);
562
563 bucket = bch_bucket_alloc(ca, RESERVE_PRIO, true);
564 BUG_ON(bucket == -1);
565
566 mutex_unlock(&ca->set->bucket_lock);
567 prio_io(ca, bucket, REQ_OP_WRITE, 0);
568 mutex_lock(&ca->set->bucket_lock);
569
570 ca->prio_buckets[i] = bucket;
571 atomic_dec_bug(&ca->buckets[bucket].pin);
572 }
573
574 mutex_unlock(&ca->set->bucket_lock);
575
576 bch_journal_meta(ca->set, &cl);
577 closure_sync(&cl);
578
579 mutex_lock(&ca->set->bucket_lock);
580
581 /*
582 * Don't want the old priorities to get garbage collected until after we
583 * finish writing the new ones, and they're journalled
584 */
585 for (i = 0; i < prio_buckets(ca); i++) {
586 if (ca->prio_last_buckets[i])
587 __bch_bucket_free(ca,
588 &ca->buckets[ca->prio_last_buckets[i]]);
589
590 ca->prio_last_buckets[i] = ca->prio_buckets[i];
591 }
592 }
593
594 static void prio_read(struct cache *ca, uint64_t bucket)
595 {
596 struct prio_set *p = ca->disk_buckets;
597 struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
598 struct bucket *b;
599 unsigned bucket_nr = 0;
600
601 for (b = ca->buckets;
602 b < ca->buckets + ca->sb.nbuckets;
603 b++, d++) {
604 if (d == end) {
605 ca->prio_buckets[bucket_nr] = bucket;
606 ca->prio_last_buckets[bucket_nr] = bucket;
607 bucket_nr++;
608
609 prio_io(ca, bucket, REQ_OP_READ, 0);
610
611 if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8))
612 pr_warn("bad csum reading priorities");
613
614 if (p->magic != pset_magic(&ca->sb))
615 pr_warn("bad magic reading priorities");
616
617 bucket = p->next_bucket;
618 d = p->data;
619 }
620
621 b->prio = le16_to_cpu(d->prio);
622 b->gen = b->last_gc = d->gen;
623 }
624 }
625
626 /* Bcache device */
627
628 static int open_dev(struct block_device *b, fmode_t mode)
629 {
630 struct bcache_device *d = b->bd_disk->private_data;
631 if (test_bit(BCACHE_DEV_CLOSING, &d->flags))
632 return -ENXIO;
633
634 closure_get(&d->cl);
635 return 0;
636 }
637
638 static void release_dev(struct gendisk *b, fmode_t mode)
639 {
640 struct bcache_device *d = b->private_data;
641 closure_put(&d->cl);
642 }
643
644 static int ioctl_dev(struct block_device *b, fmode_t mode,
645 unsigned int cmd, unsigned long arg)
646 {
647 struct bcache_device *d = b->bd_disk->private_data;
648 return d->ioctl(d, mode, cmd, arg);
649 }
650
651 static const struct block_device_operations bcache_ops = {
652 .open = open_dev,
653 .release = release_dev,
654 .ioctl = ioctl_dev,
655 .owner = THIS_MODULE,
656 };
657
658 void bcache_device_stop(struct bcache_device *d)
659 {
660 if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags))
661 closure_queue(&d->cl);
662 }
663
664 static void bcache_device_unlink(struct bcache_device *d)
665 {
666 lockdep_assert_held(&bch_register_lock);
667
668 if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) {
669 unsigned i;
670 struct cache *ca;
671
672 sysfs_remove_link(&d->c->kobj, d->name);
673 sysfs_remove_link(&d->kobj, "cache");
674
675 for_each_cache(ca, d->c, i)
676 bd_unlink_disk_holder(ca->bdev, d->disk);
677 }
678 }
679
680 static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
681 const char *name)
682 {
683 unsigned i;
684 struct cache *ca;
685
686 for_each_cache(ca, d->c, i)
687 bd_link_disk_holder(ca->bdev, d->disk);
688
689 snprintf(d->name, BCACHEDEVNAME_SIZE,
690 "%s%u", name, d->id);
691
692 WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
693 sysfs_create_link(&c->kobj, &d->kobj, d->name),
694 "Couldn't create device <-> cache set symlinks");
695
696 clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags);
697 }
698
699 static void bcache_device_detach(struct bcache_device *d)
700 {
701 lockdep_assert_held(&bch_register_lock);
702
703 if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) {
704 struct uuid_entry *u = d->c->uuids + d->id;
705
706 SET_UUID_FLASH_ONLY(u, 0);
707 memcpy(u->uuid, invalid_uuid, 16);
708 u->invalidated = cpu_to_le32(get_seconds());
709 bch_uuid_write(d->c);
710 }
711
712 bcache_device_unlink(d);
713
714 d->c->devices[d->id] = NULL;
715 closure_put(&d->c->caching);
716 d->c = NULL;
717 }
718
719 static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
720 unsigned id)
721 {
722 d->id = id;
723 d->c = c;
724 c->devices[id] = d;
725
726 if (id >= c->devices_max_used)
727 c->devices_max_used = id + 1;
728
729 closure_get(&c->caching);
730 }
731
732 static inline int first_minor_to_idx(int first_minor)
733 {
734 return (first_minor/BCACHE_MINORS);
735 }
736
737 static inline int idx_to_first_minor(int idx)
738 {
739 return (idx * BCACHE_MINORS);
740 }
741
742 static void bcache_device_free(struct bcache_device *d)
743 {
744 lockdep_assert_held(&bch_register_lock);
745
746 pr_info("%s stopped", d->disk->disk_name);
747
748 if (d->c)
749 bcache_device_detach(d);
750 if (d->disk && d->disk->flags & GENHD_FL_UP)
751 del_gendisk(d->disk);
752 if (d->disk && d->disk->queue)
753 blk_cleanup_queue(d->disk->queue);
754 if (d->disk) {
755 ida_simple_remove(&bcache_device_idx,
756 first_minor_to_idx(d->disk->first_minor));
757 put_disk(d->disk);
758 }
759
760 if (d->bio_split)
761 bioset_free(d->bio_split);
762 kvfree(d->full_dirty_stripes);
763 kvfree(d->stripe_sectors_dirty);
764
765 closure_debug_destroy(&d->cl);
766 }
767
768 static int bcache_device_init(struct bcache_device *d, unsigned block_size,
769 sector_t sectors)
770 {
771 struct request_queue *q;
772 size_t n;
773 int idx;
774
775 if (!d->stripe_size)
776 d->stripe_size = 1 << 31;
777
778 d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
779
780 if (!d->nr_stripes ||
781 d->nr_stripes > INT_MAX ||
782 d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
783 pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)",
784 (unsigned)d->nr_stripes);
785 return -ENOMEM;
786 }
787
788 n = d->nr_stripes * sizeof(atomic_t);
789 d->stripe_sectors_dirty = kvzalloc(n, GFP_KERNEL);
790 if (!d->stripe_sectors_dirty)
791 return -ENOMEM;
792
793 n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long);
794 d->full_dirty_stripes = kvzalloc(n, GFP_KERNEL);
795 if (!d->full_dirty_stripes)
796 return -ENOMEM;
797
798 idx = ida_simple_get(&bcache_device_idx, 0,
799 BCACHE_DEVICE_IDX_MAX, GFP_KERNEL);
800 if (idx < 0)
801 return idx;
802
803 if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio),
804 BIOSET_NEED_BVECS |
805 BIOSET_NEED_RESCUER)) ||
806 !(d->disk = alloc_disk(BCACHE_MINORS))) {
807 ida_simple_remove(&bcache_device_idx, idx);
808 return -ENOMEM;
809 }
810
811 set_capacity(d->disk, sectors);
812 snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", idx);
813
814 d->disk->major = bcache_major;
815 d->disk->first_minor = idx_to_first_minor(idx);
816 d->disk->fops = &bcache_ops;
817 d->disk->private_data = d;
818
819 q = blk_alloc_queue(GFP_KERNEL);
820 if (!q)
821 return -ENOMEM;
822
823 blk_queue_make_request(q, NULL);
824 d->disk->queue = q;
825 q->queuedata = d;
826 q->backing_dev_info->congested_data = d;
827 q->limits.max_hw_sectors = UINT_MAX;
828 q->limits.max_sectors = UINT_MAX;
829 q->limits.max_segment_size = UINT_MAX;
830 q->limits.max_segments = BIO_MAX_PAGES;
831 blk_queue_max_discard_sectors(q, UINT_MAX);
832 q->limits.discard_granularity = 512;
833 q->limits.io_min = block_size;
834 q->limits.logical_block_size = block_size;
835 q->limits.physical_block_size = block_size;
836 set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags);
837 clear_bit(QUEUE_FLAG_ADD_RANDOM, &d->disk->queue->queue_flags);
838 set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags);
839
840 blk_queue_write_cache(q, true, true);
841
842 return 0;
843 }
844
845 /* Cached device */
846
847 static void calc_cached_dev_sectors(struct cache_set *c)
848 {
849 uint64_t sectors = 0;
850 struct cached_dev *dc;
851
852 list_for_each_entry(dc, &c->cached_devs, list)
853 sectors += bdev_sectors(dc->bdev);
854
855 c->cached_dev_sectors = sectors;
856 }
857
858 void bch_cached_dev_run(struct cached_dev *dc)
859 {
860 struct bcache_device *d = &dc->disk;
861 char buf[SB_LABEL_SIZE + 1];
862 char *env[] = {
863 "DRIVER=bcache",
864 kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid),
865 NULL,
866 NULL,
867 };
868
869 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
870 buf[SB_LABEL_SIZE] = '\0';
871 env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf);
872
873 if (atomic_xchg(&dc->running, 1)) {
874 kfree(env[1]);
875 kfree(env[2]);
876 return;
877 }
878
879 if (!d->c &&
880 BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
881 struct closure cl;
882 closure_init_stack(&cl);
883
884 SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
885 bch_write_bdev_super(dc, &cl);
886 closure_sync(&cl);
887 }
888
889 add_disk(d->disk);
890 bd_link_disk_holder(dc->bdev, dc->disk.disk);
891 /* won't show up in the uevent file, use udevadm monitor -e instead
892 * only class / kset properties are persistent */
893 kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
894 kfree(env[1]);
895 kfree(env[2]);
896
897 if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
898 sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache"))
899 pr_debug("error creating sysfs link");
900 }
901
902 static void cached_dev_detach_finish(struct work_struct *w)
903 {
904 struct cached_dev *dc = container_of(w, struct cached_dev, detach);
905 char buf[BDEVNAME_SIZE];
906 struct closure cl;
907 closure_init_stack(&cl);
908
909 BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags));
910 BUG_ON(refcount_read(&dc->count));
911
912 mutex_lock(&bch_register_lock);
913
914 cancel_delayed_work_sync(&dc->writeback_rate_update);
915 if (!IS_ERR_OR_NULL(dc->writeback_thread)) {
916 kthread_stop(dc->writeback_thread);
917 dc->writeback_thread = NULL;
918 }
919
920 memset(&dc->sb.set_uuid, 0, 16);
921 SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
922
923 bch_write_bdev_super(dc, &cl);
924 closure_sync(&cl);
925
926 bcache_device_detach(&dc->disk);
927 list_move(&dc->list, &uncached_devices);
928
929 clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags);
930 clear_bit(BCACHE_DEV_UNLINK_DONE, &dc->disk.flags);
931
932 mutex_unlock(&bch_register_lock);
933
934 pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
935
936 /* Drop ref we took in cached_dev_detach() */
937 closure_put(&dc->disk.cl);
938 }
939
940 void bch_cached_dev_detach(struct cached_dev *dc)
941 {
942 lockdep_assert_held(&bch_register_lock);
943
944 if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
945 return;
946
947 if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
948 return;
949
950 /*
951 * Block the device from being closed and freed until we're finished
952 * detaching
953 */
954 closure_get(&dc->disk.cl);
955
956 bch_writeback_queue(dc);
957 cached_dev_put(dc);
958 }
959
960 int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c,
961 uint8_t *set_uuid)
962 {
963 uint32_t rtime = cpu_to_le32(get_seconds());
964 struct uuid_entry *u;
965 char buf[BDEVNAME_SIZE];
966
967 bdevname(dc->bdev, buf);
968
969 if ((set_uuid && memcmp(set_uuid, c->sb.set_uuid, 16)) ||
970 (!set_uuid && memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16)))
971 return -ENOENT;
972
973 if (dc->disk.c) {
974 pr_err("Can't attach %s: already attached", buf);
975 return -EINVAL;
976 }
977
978 if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
979 pr_err("Can't attach %s: shutting down", buf);
980 return -EINVAL;
981 }
982
983 if (dc->sb.block_size < c->sb.block_size) {
984 /* Will die */
985 pr_err("Couldn't attach %s: block size less than set's block size",
986 buf);
987 return -EINVAL;
988 }
989
990 u = uuid_find(c, dc->sb.uuid);
991
992 if (u &&
993 (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
994 BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
995 memcpy(u->uuid, invalid_uuid, 16);
996 u->invalidated = cpu_to_le32(get_seconds());
997 u = NULL;
998 }
999
1000 if (!u) {
1001 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
1002 pr_err("Couldn't find uuid for %s in set", buf);
1003 return -ENOENT;
1004 }
1005
1006 u = uuid_find_empty(c);
1007 if (!u) {
1008 pr_err("Not caching %s, no room for UUID", buf);
1009 return -EINVAL;
1010 }
1011 }
1012
1013 /* Deadlocks since we're called via sysfs...
1014 sysfs_remove_file(&dc->kobj, &sysfs_attach);
1015 */
1016
1017 if (bch_is_zero(u->uuid, 16)) {
1018 struct closure cl;
1019 closure_init_stack(&cl);
1020
1021 memcpy(u->uuid, dc->sb.uuid, 16);
1022 memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
1023 u->first_reg = u->last_reg = rtime;
1024 bch_uuid_write(c);
1025
1026 memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
1027 SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
1028
1029 bch_write_bdev_super(dc, &cl);
1030 closure_sync(&cl);
1031 } else {
1032 u->last_reg = rtime;
1033 bch_uuid_write(c);
1034 }
1035
1036 bcache_device_attach(&dc->disk, c, u - c->uuids);
1037 list_move(&dc->list, &c->cached_devs);
1038 calc_cached_dev_sectors(c);
1039
1040 smp_wmb();
1041 /*
1042 * dc->c must be set before dc->count != 0 - paired with the mb in
1043 * cached_dev_get()
1044 */
1045 refcount_set(&dc->count, 1);
1046
1047 /* Block writeback thread, but spawn it */
1048 down_write(&dc->writeback_lock);
1049 if (bch_cached_dev_writeback_start(dc)) {
1050 up_write(&dc->writeback_lock);
1051 return -ENOMEM;
1052 }
1053
1054 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
1055 bch_sectors_dirty_init(&dc->disk);
1056 atomic_set(&dc->has_dirty, 1);
1057 refcount_inc(&dc->count);
1058 bch_writeback_queue(dc);
1059 }
1060
1061 bch_cached_dev_run(dc);
1062 bcache_device_link(&dc->disk, c, "bdev");
1063
1064 /* Allow the writeback thread to proceed */
1065 up_write(&dc->writeback_lock);
1066
1067 pr_info("Caching %s as %s on set %pU",
1068 bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
1069 dc->disk.c->sb.set_uuid);
1070 return 0;
1071 }
1072
1073 void bch_cached_dev_release(struct kobject *kobj)
1074 {
1075 struct cached_dev *dc = container_of(kobj, struct cached_dev,
1076 disk.kobj);
1077 kfree(dc);
1078 module_put(THIS_MODULE);
1079 }
1080
1081 static void cached_dev_free(struct closure *cl)
1082 {
1083 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1084
1085 cancel_delayed_work_sync(&dc->writeback_rate_update);
1086 if (!IS_ERR_OR_NULL(dc->writeback_thread))
1087 kthread_stop(dc->writeback_thread);
1088 if (dc->writeback_write_wq)
1089 destroy_workqueue(dc->writeback_write_wq);
1090
1091 mutex_lock(&bch_register_lock);
1092
1093 if (atomic_read(&dc->running))
1094 bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
1095 bcache_device_free(&dc->disk);
1096 list_del(&dc->list);
1097
1098 mutex_unlock(&bch_register_lock);
1099
1100 if (!IS_ERR_OR_NULL(dc->bdev))
1101 blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1102
1103 wake_up(&unregister_wait);
1104
1105 kobject_put(&dc->disk.kobj);
1106 }
1107
1108 static void cached_dev_flush(struct closure *cl)
1109 {
1110 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1111 struct bcache_device *d = &dc->disk;
1112
1113 mutex_lock(&bch_register_lock);
1114 bcache_device_unlink(d);
1115 mutex_unlock(&bch_register_lock);
1116
1117 bch_cache_accounting_destroy(&dc->accounting);
1118 kobject_del(&d->kobj);
1119
1120 continue_at(cl, cached_dev_free, system_wq);
1121 }
1122
1123 static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
1124 {
1125 int ret;
1126 struct io *io;
1127 struct request_queue *q = bdev_get_queue(dc->bdev);
1128
1129 __module_get(THIS_MODULE);
1130 INIT_LIST_HEAD(&dc->list);
1131 closure_init(&dc->disk.cl, NULL);
1132 set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
1133 kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
1134 INIT_WORK(&dc->detach, cached_dev_detach_finish);
1135 sema_init(&dc->sb_write_mutex, 1);
1136 INIT_LIST_HEAD(&dc->io_lru);
1137 spin_lock_init(&dc->io_lock);
1138 bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
1139
1140 dc->sequential_cutoff = 4 << 20;
1141
1142 for (io = dc->io; io < dc->io + RECENT_IO; io++) {
1143 list_add(&io->lru, &dc->io_lru);
1144 hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
1145 }
1146
1147 dc->disk.stripe_size = q->limits.io_opt >> 9;
1148
1149 if (dc->disk.stripe_size)
1150 dc->partial_stripes_expensive =
1151 q->limits.raid_partial_stripes_expensive;
1152
1153 ret = bcache_device_init(&dc->disk, block_size,
1154 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1155 if (ret)
1156 return ret;
1157
1158 dc->disk.disk->queue->backing_dev_info->ra_pages =
1159 max(dc->disk.disk->queue->backing_dev_info->ra_pages,
1160 q->backing_dev_info->ra_pages);
1161
1162 bch_cached_dev_request_init(dc);
1163 bch_cached_dev_writeback_init(dc);
1164 return 0;
1165 }
1166
1167 /* Cached device - bcache superblock */
1168
1169 static void register_bdev(struct cache_sb *sb, struct page *sb_page,
1170 struct block_device *bdev,
1171 struct cached_dev *dc)
1172 {
1173 char name[BDEVNAME_SIZE];
1174 const char *err = "cannot allocate memory";
1175 struct cache_set *c;
1176
1177 memcpy(&dc->sb, sb, sizeof(struct cache_sb));
1178 dc->bdev = bdev;
1179 dc->bdev->bd_holder = dc;
1180
1181 bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1);
1182 bio_first_bvec_all(&dc->sb_bio)->bv_page = sb_page;
1183 get_page(sb_page);
1184
1185 if (cached_dev_init(dc, sb->block_size << 9))
1186 goto err;
1187
1188 err = "error creating kobject";
1189 if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
1190 "bcache"))
1191 goto err;
1192 if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
1193 goto err;
1194
1195 pr_info("registered backing device %s", bdevname(bdev, name));
1196
1197 list_add(&dc->list, &uncached_devices);
1198 list_for_each_entry(c, &bch_cache_sets, list)
1199 bch_cached_dev_attach(dc, c, NULL);
1200
1201 if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
1202 BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
1203 bch_cached_dev_run(dc);
1204
1205 return;
1206 err:
1207 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1208 bcache_device_stop(&dc->disk);
1209 }
1210
1211 /* Flash only volumes */
1212
1213 void bch_flash_dev_release(struct kobject *kobj)
1214 {
1215 struct bcache_device *d = container_of(kobj, struct bcache_device,
1216 kobj);
1217 kfree(d);
1218 }
1219
1220 static void flash_dev_free(struct closure *cl)
1221 {
1222 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1223 mutex_lock(&bch_register_lock);
1224 bcache_device_free(d);
1225 mutex_unlock(&bch_register_lock);
1226 kobject_put(&d->kobj);
1227 }
1228
1229 static void flash_dev_flush(struct closure *cl)
1230 {
1231 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1232
1233 mutex_lock(&bch_register_lock);
1234 bcache_device_unlink(d);
1235 mutex_unlock(&bch_register_lock);
1236 kobject_del(&d->kobj);
1237 continue_at(cl, flash_dev_free, system_wq);
1238 }
1239
1240 static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
1241 {
1242 struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
1243 GFP_KERNEL);
1244 if (!d)
1245 return -ENOMEM;
1246
1247 closure_init(&d->cl, NULL);
1248 set_closure_fn(&d->cl, flash_dev_flush, system_wq);
1249
1250 kobject_init(&d->kobj, &bch_flash_dev_ktype);
1251
1252 if (bcache_device_init(d, block_bytes(c), u->sectors))
1253 goto err;
1254
1255 bcache_device_attach(d, c, u - c->uuids);
1256 bch_sectors_dirty_init(d);
1257 bch_flash_dev_request_init(d);
1258 add_disk(d->disk);
1259
1260 if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache"))
1261 goto err;
1262
1263 bcache_device_link(d, c, "volume");
1264
1265 return 0;
1266 err:
1267 kobject_put(&d->kobj);
1268 return -ENOMEM;
1269 }
1270
1271 static int flash_devs_run(struct cache_set *c)
1272 {
1273 int ret = 0;
1274 struct uuid_entry *u;
1275
1276 for (u = c->uuids;
1277 u < c->uuids + c->devices_max_used && !ret;
1278 u++)
1279 if (UUID_FLASH_ONLY(u))
1280 ret = flash_dev_run(c, u);
1281
1282 return ret;
1283 }
1284
1285 int bch_flash_dev_create(struct cache_set *c, uint64_t size)
1286 {
1287 struct uuid_entry *u;
1288
1289 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1290 return -EINTR;
1291
1292 if (!test_bit(CACHE_SET_RUNNING, &c->flags))
1293 return -EPERM;
1294
1295 u = uuid_find_empty(c);
1296 if (!u) {
1297 pr_err("Can't create volume, no room for UUID");
1298 return -EINVAL;
1299 }
1300
1301 get_random_bytes(u->uuid, 16);
1302 memset(u->label, 0, 32);
1303 u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
1304
1305 SET_UUID_FLASH_ONLY(u, 1);
1306 u->sectors = size >> 9;
1307
1308 bch_uuid_write(c);
1309
1310 return flash_dev_run(c, u);
1311 }
1312
1313 /* Cache set */
1314
1315 __printf(2, 3)
1316 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
1317 {
1318 va_list args;
1319
1320 if (c->on_error != ON_ERROR_PANIC &&
1321 test_bit(CACHE_SET_STOPPING, &c->flags))
1322 return false;
1323
1324 /* XXX: we can be called from atomic context
1325 acquire_console_sem();
1326 */
1327
1328 printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid);
1329
1330 va_start(args, fmt);
1331 vprintk(fmt, args);
1332 va_end(args);
1333
1334 printk(", disabling caching\n");
1335
1336 if (c->on_error == ON_ERROR_PANIC)
1337 panic("panic forced after error\n");
1338
1339 bch_cache_set_unregister(c);
1340 return true;
1341 }
1342
1343 void bch_cache_set_release(struct kobject *kobj)
1344 {
1345 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
1346 kfree(c);
1347 module_put(THIS_MODULE);
1348 }
1349
1350 static void cache_set_free(struct closure *cl)
1351 {
1352 struct cache_set *c = container_of(cl, struct cache_set, cl);
1353 struct cache *ca;
1354 unsigned i;
1355
1356 if (!IS_ERR_OR_NULL(c->debug))
1357 debugfs_remove(c->debug);
1358
1359 bch_open_buckets_free(c);
1360 bch_btree_cache_free(c);
1361 bch_journal_free(c);
1362
1363 for_each_cache(ca, c, i)
1364 if (ca) {
1365 ca->set = NULL;
1366 c->cache[ca->sb.nr_this_dev] = NULL;
1367 kobject_put(&ca->kobj);
1368 }
1369
1370 bch_bset_sort_state_free(&c->sort);
1371 free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
1372
1373 if (c->moving_gc_wq)
1374 destroy_workqueue(c->moving_gc_wq);
1375 if (c->bio_split)
1376 bioset_free(c->bio_split);
1377 if (c->fill_iter)
1378 mempool_destroy(c->fill_iter);
1379 if (c->bio_meta)
1380 mempool_destroy(c->bio_meta);
1381 if (c->search)
1382 mempool_destroy(c->search);
1383 kfree(c->devices);
1384
1385 mutex_lock(&bch_register_lock);
1386 list_del(&c->list);
1387 mutex_unlock(&bch_register_lock);
1388
1389 pr_info("Cache set %pU unregistered", c->sb.set_uuid);
1390 wake_up(&unregister_wait);
1391
1392 closure_debug_destroy(&c->cl);
1393 kobject_put(&c->kobj);
1394 }
1395
1396 static void cache_set_flush(struct closure *cl)
1397 {
1398 struct cache_set *c = container_of(cl, struct cache_set, caching);
1399 struct cache *ca;
1400 struct btree *b;
1401 unsigned i;
1402
1403 bch_cache_accounting_destroy(&c->accounting);
1404
1405 kobject_put(&c->internal);
1406 kobject_del(&c->kobj);
1407
1408 if (c->gc_thread)
1409 kthread_stop(c->gc_thread);
1410
1411 if (!IS_ERR_OR_NULL(c->root))
1412 list_add(&c->root->list, &c->btree_cache);
1413
1414 /* Should skip this if we're unregistering because of an error */
1415 list_for_each_entry(b, &c->btree_cache, list) {
1416 mutex_lock(&b->write_lock);
1417 if (btree_node_dirty(b))
1418 __bch_btree_node_write(b, NULL);
1419 mutex_unlock(&b->write_lock);
1420 }
1421
1422 for_each_cache(ca, c, i)
1423 if (ca->alloc_thread)
1424 kthread_stop(ca->alloc_thread);
1425
1426 if (c->journal.cur) {
1427 cancel_delayed_work_sync(&c->journal.work);
1428 /* flush last journal entry if needed */
1429 c->journal.work.work.func(&c->journal.work.work);
1430 }
1431
1432 closure_return(cl);
1433 }
1434
1435 static void __cache_set_unregister(struct closure *cl)
1436 {
1437 struct cache_set *c = container_of(cl, struct cache_set, caching);
1438 struct cached_dev *dc;
1439 size_t i;
1440
1441 mutex_lock(&bch_register_lock);
1442
1443 for (i = 0; i < c->devices_max_used; i++)
1444 if (c->devices[i]) {
1445 if (!UUID_FLASH_ONLY(&c->uuids[i]) &&
1446 test_bit(CACHE_SET_UNREGISTERING, &c->flags)) {
1447 dc = container_of(c->devices[i],
1448 struct cached_dev, disk);
1449 bch_cached_dev_detach(dc);
1450 } else {
1451 bcache_device_stop(c->devices[i]);
1452 }
1453 }
1454
1455 mutex_unlock(&bch_register_lock);
1456
1457 continue_at(cl, cache_set_flush, system_wq);
1458 }
1459
1460 void bch_cache_set_stop(struct cache_set *c)
1461 {
1462 if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
1463 closure_queue(&c->caching);
1464 }
1465
1466 void bch_cache_set_unregister(struct cache_set *c)
1467 {
1468 set_bit(CACHE_SET_UNREGISTERING, &c->flags);
1469 bch_cache_set_stop(c);
1470 }
1471
1472 #define alloc_bucket_pages(gfp, c) \
1473 ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c))))
1474
1475 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1476 {
1477 int iter_size;
1478 struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
1479 if (!c)
1480 return NULL;
1481
1482 __module_get(THIS_MODULE);
1483 closure_init(&c->cl, NULL);
1484 set_closure_fn(&c->cl, cache_set_free, system_wq);
1485
1486 closure_init(&c->caching, &c->cl);
1487 set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
1488
1489 /* Maybe create continue_at_noreturn() and use it here? */
1490 closure_set_stopped(&c->cl);
1491 closure_put(&c->cl);
1492
1493 kobject_init(&c->kobj, &bch_cache_set_ktype);
1494 kobject_init(&c->internal, &bch_cache_set_internal_ktype);
1495
1496 bch_cache_accounting_init(&c->accounting, &c->cl);
1497
1498 memcpy(c->sb.set_uuid, sb->set_uuid, 16);
1499 c->sb.block_size = sb->block_size;
1500 c->sb.bucket_size = sb->bucket_size;
1501 c->sb.nr_in_set = sb->nr_in_set;
1502 c->sb.last_mount = sb->last_mount;
1503 c->bucket_bits = ilog2(sb->bucket_size);
1504 c->block_bits = ilog2(sb->block_size);
1505 c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
1506 c->devices_max_used = 0;
1507 c->btree_pages = bucket_pages(c);
1508 if (c->btree_pages > BTREE_MAX_PAGES)
1509 c->btree_pages = max_t(int, c->btree_pages / 4,
1510 BTREE_MAX_PAGES);
1511
1512 sema_init(&c->sb_write_mutex, 1);
1513 mutex_init(&c->bucket_lock);
1514 init_waitqueue_head(&c->btree_cache_wait);
1515 init_waitqueue_head(&c->bucket_wait);
1516 init_waitqueue_head(&c->gc_wait);
1517 sema_init(&c->uuid_write_mutex, 1);
1518
1519 spin_lock_init(&c->btree_gc_time.lock);
1520 spin_lock_init(&c->btree_split_time.lock);
1521 spin_lock_init(&c->btree_read_time.lock);
1522
1523 bch_moving_init_cache_set(c);
1524
1525 INIT_LIST_HEAD(&c->list);
1526 INIT_LIST_HEAD(&c->cached_devs);
1527 INIT_LIST_HEAD(&c->btree_cache);
1528 INIT_LIST_HEAD(&c->btree_cache_freeable);
1529 INIT_LIST_HEAD(&c->btree_cache_freed);
1530 INIT_LIST_HEAD(&c->data_buckets);
1531
1532 c->search = mempool_create_slab_pool(32, bch_search_cache);
1533 if (!c->search)
1534 goto err;
1535
1536 iter_size = (sb->bucket_size / sb->block_size + 1) *
1537 sizeof(struct btree_iter_set);
1538
1539 if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) ||
1540 !(c->bio_meta = mempool_create_kmalloc_pool(2,
1541 sizeof(struct bbio) + sizeof(struct bio_vec) *
1542 bucket_pages(c))) ||
1543 !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
1544 !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio),
1545 BIOSET_NEED_BVECS |
1546 BIOSET_NEED_RESCUER)) ||
1547 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1548 !(c->moving_gc_wq = alloc_workqueue("bcache_gc",
1549 WQ_MEM_RECLAIM, 0)) ||
1550 bch_journal_alloc(c) ||
1551 bch_btree_cache_alloc(c) ||
1552 bch_open_buckets_alloc(c) ||
1553 bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages)))
1554 goto err;
1555
1556 c->congested_read_threshold_us = 2000;
1557 c->congested_write_threshold_us = 20000;
1558 c->error_limit = DEFAULT_IO_ERROR_LIMIT;
1559
1560 return c;
1561 err:
1562 bch_cache_set_unregister(c);
1563 return NULL;
1564 }
1565
1566 static void run_cache_set(struct cache_set *c)
1567 {
1568 const char *err = "cannot allocate memory";
1569 struct cached_dev *dc, *t;
1570 struct cache *ca;
1571 struct closure cl;
1572 unsigned i;
1573
1574 closure_init_stack(&cl);
1575
1576 for_each_cache(ca, c, i)
1577 c->nbuckets += ca->sb.nbuckets;
1578 set_gc_sectors(c);
1579
1580 if (CACHE_SYNC(&c->sb)) {
1581 LIST_HEAD(journal);
1582 struct bkey *k;
1583 struct jset *j;
1584
1585 err = "cannot allocate memory for journal";
1586 if (bch_journal_read(c, &journal))
1587 goto err;
1588
1589 pr_debug("btree_journal_read() done");
1590
1591 err = "no journal entries found";
1592 if (list_empty(&journal))
1593 goto err;
1594
1595 j = &list_entry(journal.prev, struct journal_replay, list)->j;
1596
1597 err = "IO error reading priorities";
1598 for_each_cache(ca, c, i)
1599 prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]);
1600
1601 /*
1602 * If prio_read() fails it'll call cache_set_error and we'll
1603 * tear everything down right away, but if we perhaps checked
1604 * sooner we could avoid journal replay.
1605 */
1606
1607 k = &j->btree_root;
1608
1609 err = "bad btree root";
1610 if (__bch_btree_ptr_invalid(c, k))
1611 goto err;
1612
1613 err = "error reading btree root";
1614 c->root = bch_btree_node_get(c, NULL, k, j->btree_level, true, NULL);
1615 if (IS_ERR_OR_NULL(c->root))
1616 goto err;
1617
1618 list_del_init(&c->root->list);
1619 rw_unlock(true, c->root);
1620
1621 err = uuid_read(c, j, &cl);
1622 if (err)
1623 goto err;
1624
1625 err = "error in recovery";
1626 if (bch_btree_check(c))
1627 goto err;
1628
1629 bch_journal_mark(c, &journal);
1630 bch_initial_gc_finish(c);
1631 pr_debug("btree_check() done");
1632
1633 /*
1634 * bcache_journal_next() can't happen sooner, or
1635 * btree_gc_finish() will give spurious errors about last_gc >
1636 * gc_gen - this is a hack but oh well.
1637 */
1638 bch_journal_next(&c->journal);
1639
1640 err = "error starting allocator thread";
1641 for_each_cache(ca, c, i)
1642 if (bch_cache_allocator_start(ca))
1643 goto err;
1644
1645 /*
1646 * First place it's safe to allocate: btree_check() and
1647 * btree_gc_finish() have to run before we have buckets to
1648 * allocate, and bch_bucket_alloc_set() might cause a journal
1649 * entry to be written so bcache_journal_next() has to be called
1650 * first.
1651 *
1652 * If the uuids were in the old format we have to rewrite them
1653 * before the next journal entry is written:
1654 */
1655 if (j->version < BCACHE_JSET_VERSION_UUID)
1656 __uuid_write(c);
1657
1658 bch_journal_replay(c, &journal);
1659 } else {
1660 pr_notice("invalidating existing data");
1661
1662 for_each_cache(ca, c, i) {
1663 unsigned j;
1664
1665 ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
1666 2, SB_JOURNAL_BUCKETS);
1667
1668 for (j = 0; j < ca->sb.keys; j++)
1669 ca->sb.d[j] = ca->sb.first_bucket + j;
1670 }
1671
1672 bch_initial_gc_finish(c);
1673
1674 err = "error starting allocator thread";
1675 for_each_cache(ca, c, i)
1676 if (bch_cache_allocator_start(ca))
1677 goto err;
1678
1679 mutex_lock(&c->bucket_lock);
1680 for_each_cache(ca, c, i)
1681 bch_prio_write(ca);
1682 mutex_unlock(&c->bucket_lock);
1683
1684 err = "cannot allocate new UUID bucket";
1685 if (__uuid_write(c))
1686 goto err;
1687
1688 err = "cannot allocate new btree root";
1689 c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL);
1690 if (IS_ERR_OR_NULL(c->root))
1691 goto err;
1692
1693 mutex_lock(&c->root->write_lock);
1694 bkey_copy_key(&c->root->key, &MAX_KEY);
1695 bch_btree_node_write(c->root, &cl);
1696 mutex_unlock(&c->root->write_lock);
1697
1698 bch_btree_set_root(c->root);
1699 rw_unlock(true, c->root);
1700
1701 /*
1702 * We don't want to write the first journal entry until
1703 * everything is set up - fortunately journal entries won't be
1704 * written until the SET_CACHE_SYNC() here:
1705 */
1706 SET_CACHE_SYNC(&c->sb, true);
1707
1708 bch_journal_next(&c->journal);
1709 bch_journal_meta(c, &cl);
1710 }
1711
1712 err = "error starting gc thread";
1713 if (bch_gc_thread_start(c))
1714 goto err;
1715
1716 closure_sync(&cl);
1717 c->sb.last_mount = get_seconds();
1718 bcache_write_super(c);
1719
1720 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1721 bch_cached_dev_attach(dc, c, NULL);
1722
1723 flash_devs_run(c);
1724
1725 set_bit(CACHE_SET_RUNNING, &c->flags);
1726 return;
1727 err:
1728 closure_sync(&cl);
1729 /* XXX: test this, it's broken */
1730 bch_cache_set_error(c, "%s", err);
1731 }
1732
1733 static bool can_attach_cache(struct cache *ca, struct cache_set *c)
1734 {
1735 return ca->sb.block_size == c->sb.block_size &&
1736 ca->sb.bucket_size == c->sb.bucket_size &&
1737 ca->sb.nr_in_set == c->sb.nr_in_set;
1738 }
1739
1740 static const char *register_cache_set(struct cache *ca)
1741 {
1742 char buf[12];
1743 const char *err = "cannot allocate memory";
1744 struct cache_set *c;
1745
1746 list_for_each_entry(c, &bch_cache_sets, list)
1747 if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
1748 if (c->cache[ca->sb.nr_this_dev])
1749 return "duplicate cache set member";
1750
1751 if (!can_attach_cache(ca, c))
1752 return "cache sb does not match set";
1753
1754 if (!CACHE_SYNC(&ca->sb))
1755 SET_CACHE_SYNC(&c->sb, false);
1756
1757 goto found;
1758 }
1759
1760 c = bch_cache_set_alloc(&ca->sb);
1761 if (!c)
1762 return err;
1763
1764 err = "error creating kobject";
1765 if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
1766 kobject_add(&c->internal, &c->kobj, "internal"))
1767 goto err;
1768
1769 if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
1770 goto err;
1771
1772 bch_debug_init_cache_set(c);
1773
1774 list_add(&c->list, &bch_cache_sets);
1775 found:
1776 sprintf(buf, "cache%i", ca->sb.nr_this_dev);
1777 if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
1778 sysfs_create_link(&c->kobj, &ca->kobj, buf))
1779 goto err;
1780
1781 if (ca->sb.seq > c->sb.seq) {
1782 c->sb.version = ca->sb.version;
1783 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
1784 c->sb.flags = ca->sb.flags;
1785 c->sb.seq = ca->sb.seq;
1786 pr_debug("set version = %llu", c->sb.version);
1787 }
1788
1789 kobject_get(&ca->kobj);
1790 ca->set = c;
1791 ca->set->cache[ca->sb.nr_this_dev] = ca;
1792 c->cache_by_alloc[c->caches_loaded++] = ca;
1793
1794 if (c->caches_loaded == c->sb.nr_in_set)
1795 run_cache_set(c);
1796
1797 return NULL;
1798 err:
1799 bch_cache_set_unregister(c);
1800 return err;
1801 }
1802
1803 /* Cache device */
1804
1805 void bch_cache_release(struct kobject *kobj)
1806 {
1807 struct cache *ca = container_of(kobj, struct cache, kobj);
1808 unsigned i;
1809
1810 if (ca->set) {
1811 BUG_ON(ca->set->cache[ca->sb.nr_this_dev] != ca);
1812 ca->set->cache[ca->sb.nr_this_dev] = NULL;
1813 }
1814
1815 free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
1816 kfree(ca->prio_buckets);
1817 vfree(ca->buckets);
1818
1819 free_heap(&ca->heap);
1820 free_fifo(&ca->free_inc);
1821
1822 for (i = 0; i < RESERVE_NR; i++)
1823 free_fifo(&ca->free[i]);
1824
1825 if (ca->sb_bio.bi_inline_vecs[0].bv_page)
1826 put_page(bio_first_page_all(&ca->sb_bio));
1827
1828 if (!IS_ERR_OR_NULL(ca->bdev))
1829 blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1830
1831 kfree(ca);
1832 module_put(THIS_MODULE);
1833 }
1834
1835 static int cache_alloc(struct cache *ca)
1836 {
1837 size_t free;
1838 size_t btree_buckets;
1839 struct bucket *b;
1840
1841 __module_get(THIS_MODULE);
1842 kobject_init(&ca->kobj, &bch_cache_ktype);
1843
1844 bio_init(&ca->journal.bio, ca->journal.bio.bi_inline_vecs, 8);
1845
1846 /*
1847 * when ca->sb.njournal_buckets is not zero, journal exists,
1848 * and in bch_journal_replay(), tree node may split,
1849 * so bucket of RESERVE_BTREE type is needed,
1850 * the worst situation is all journal buckets are valid journal,
1851 * and all the keys need to replay,
1852 * so the number of RESERVE_BTREE type buckets should be as much
1853 * as journal buckets
1854 */
1855 btree_buckets = ca->sb.njournal_buckets ?: 8;
1856 free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
1857
1858 if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, GFP_KERNEL) ||
1859 !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
1860 !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
1861 !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
1862 !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
1863 !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
1864 !(ca->buckets = vzalloc(sizeof(struct bucket) *
1865 ca->sb.nbuckets)) ||
1866 !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
1867 2, GFP_KERNEL)) ||
1868 !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)))
1869 return -ENOMEM;
1870
1871 ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
1872
1873 for_each_bucket(b, ca)
1874 atomic_set(&b->pin, 0);
1875
1876 return 0;
1877 }
1878
1879 static int register_cache(struct cache_sb *sb, struct page *sb_page,
1880 struct block_device *bdev, struct cache *ca)
1881 {
1882 char name[BDEVNAME_SIZE];
1883 const char *err = NULL; /* must be set for any error case */
1884 int ret = 0;
1885
1886 memcpy(&ca->sb, sb, sizeof(struct cache_sb));
1887 ca->bdev = bdev;
1888 ca->bdev->bd_holder = ca;
1889
1890 bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1);
1891 bio_first_bvec_all(&ca->sb_bio)->bv_page = sb_page;
1892 get_page(sb_page);
1893
1894 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1895 ca->discard = CACHE_DISCARD(&ca->sb);
1896
1897 ret = cache_alloc(ca);
1898 if (ret != 0) {
1899 if (ret == -ENOMEM)
1900 err = "cache_alloc(): -ENOMEM";
1901 else
1902 err = "cache_alloc(): unknown error";
1903 goto err;
1904 }
1905
1906 if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache")) {
1907 err = "error calling kobject_add";
1908 ret = -ENOMEM;
1909 goto out;
1910 }
1911
1912 mutex_lock(&bch_register_lock);
1913 err = register_cache_set(ca);
1914 mutex_unlock(&bch_register_lock);
1915
1916 if (err) {
1917 ret = -ENODEV;
1918 goto out;
1919 }
1920
1921 pr_info("registered cache device %s", bdevname(bdev, name));
1922
1923 out:
1924 kobject_put(&ca->kobj);
1925
1926 err:
1927 if (err)
1928 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1929
1930 return ret;
1931 }
1932
1933 /* Global interfaces/init */
1934
1935 static ssize_t register_bcache(struct kobject *, struct kobj_attribute *,
1936 const char *, size_t);
1937
1938 kobj_attribute_write(register, register_bcache);
1939 kobj_attribute_write(register_quiet, register_bcache);
1940
1941 static bool bch_is_open_backing(struct block_device *bdev) {
1942 struct cache_set *c, *tc;
1943 struct cached_dev *dc, *t;
1944
1945 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1946 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1947 if (dc->bdev == bdev)
1948 return true;
1949 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1950 if (dc->bdev == bdev)
1951 return true;
1952 return false;
1953 }
1954
1955 static bool bch_is_open_cache(struct block_device *bdev) {
1956 struct cache_set *c, *tc;
1957 struct cache *ca;
1958 unsigned i;
1959
1960 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1961 for_each_cache(ca, c, i)
1962 if (ca->bdev == bdev)
1963 return true;
1964 return false;
1965 }
1966
1967 static bool bch_is_open(struct block_device *bdev) {
1968 return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
1969 }
1970
1971 static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
1972 const char *buffer, size_t size)
1973 {
1974 ssize_t ret = size;
1975 const char *err = "cannot allocate memory";
1976 char *path = NULL;
1977 struct cache_sb *sb = NULL;
1978 struct block_device *bdev = NULL;
1979 struct page *sb_page = NULL;
1980
1981 if (!try_module_get(THIS_MODULE))
1982 return -EBUSY;
1983
1984 if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
1985 !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
1986 goto err;
1987
1988 err = "failed to open device";
1989 bdev = blkdev_get_by_path(strim(path),
1990 FMODE_READ|FMODE_WRITE|FMODE_EXCL,
1991 sb);
1992 if (IS_ERR(bdev)) {
1993 if (bdev == ERR_PTR(-EBUSY)) {
1994 bdev = lookup_bdev(strim(path));
1995 mutex_lock(&bch_register_lock);
1996 if (!IS_ERR(bdev) && bch_is_open(bdev))
1997 err = "device already registered";
1998 else
1999 err = "device busy";
2000 mutex_unlock(&bch_register_lock);
2001 if (!IS_ERR(bdev))
2002 bdput(bdev);
2003 if (attr == &ksysfs_register_quiet)
2004 goto out;
2005 }
2006 goto err;
2007 }
2008
2009 err = "failed to set blocksize";
2010 if (set_blocksize(bdev, 4096))
2011 goto err_close;
2012
2013 err = read_super(sb, bdev, &sb_page);
2014 if (err)
2015 goto err_close;
2016
2017 if (SB_IS_BDEV(sb)) {
2018 struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
2019 if (!dc)
2020 goto err_close;
2021
2022 mutex_lock(&bch_register_lock);
2023 register_bdev(sb, sb_page, bdev, dc);
2024 mutex_unlock(&bch_register_lock);
2025 } else {
2026 struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
2027 if (!ca)
2028 goto err_close;
2029
2030 if (register_cache(sb, sb_page, bdev, ca) != 0)
2031 goto err_close;
2032 }
2033 out:
2034 if (sb_page)
2035 put_page(sb_page);
2036 kfree(sb);
2037 kfree(path);
2038 module_put(THIS_MODULE);
2039 return ret;
2040
2041 err_close:
2042 blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
2043 err:
2044 pr_info("error opening %s: %s", path, err);
2045 ret = -EINVAL;
2046 goto out;
2047 }
2048
2049 static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
2050 {
2051 if (code == SYS_DOWN ||
2052 code == SYS_HALT ||
2053 code == SYS_POWER_OFF) {
2054 DEFINE_WAIT(wait);
2055 unsigned long start = jiffies;
2056 bool stopped = false;
2057
2058 struct cache_set *c, *tc;
2059 struct cached_dev *dc, *tdc;
2060
2061 mutex_lock(&bch_register_lock);
2062
2063 if (list_empty(&bch_cache_sets) &&
2064 list_empty(&uncached_devices))
2065 goto out;
2066
2067 pr_info("Stopping all devices:");
2068
2069 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
2070 bch_cache_set_stop(c);
2071
2072 list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
2073 bcache_device_stop(&dc->disk);
2074
2075 /* What's a condition variable? */
2076 while (1) {
2077 long timeout = start + 2 * HZ - jiffies;
2078
2079 stopped = list_empty(&bch_cache_sets) &&
2080 list_empty(&uncached_devices);
2081
2082 if (timeout < 0 || stopped)
2083 break;
2084
2085 prepare_to_wait(&unregister_wait, &wait,
2086 TASK_UNINTERRUPTIBLE);
2087
2088 mutex_unlock(&bch_register_lock);
2089 schedule_timeout(timeout);
2090 mutex_lock(&bch_register_lock);
2091 }
2092
2093 finish_wait(&unregister_wait, &wait);
2094
2095 if (stopped)
2096 pr_info("All devices stopped");
2097 else
2098 pr_notice("Timeout waiting for devices to be closed");
2099 out:
2100 mutex_unlock(&bch_register_lock);
2101 }
2102
2103 return NOTIFY_DONE;
2104 }
2105
2106 static struct notifier_block reboot = {
2107 .notifier_call = bcache_reboot,
2108 .priority = INT_MAX, /* before any real devices */
2109 };
2110
2111 static void bcache_exit(void)
2112 {
2113 bch_debug_exit();
2114 bch_request_exit();
2115 if (bcache_kobj)
2116 kobject_put(bcache_kobj);
2117 if (bcache_wq)
2118 destroy_workqueue(bcache_wq);
2119 if (bcache_major)
2120 unregister_blkdev(bcache_major, "bcache");
2121 unregister_reboot_notifier(&reboot);
2122 mutex_destroy(&bch_register_lock);
2123 }
2124
2125 static int __init bcache_init(void)
2126 {
2127 static const struct attribute *files[] = {
2128 &ksysfs_register.attr,
2129 &ksysfs_register_quiet.attr,
2130 NULL
2131 };
2132
2133 mutex_init(&bch_register_lock);
2134 init_waitqueue_head(&unregister_wait);
2135 register_reboot_notifier(&reboot);
2136 closure_debug_init();
2137
2138 bcache_major = register_blkdev(0, "bcache");
2139 if (bcache_major < 0) {
2140 unregister_reboot_notifier(&reboot);
2141 mutex_destroy(&bch_register_lock);
2142 return bcache_major;
2143 }
2144
2145 if (!(bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) ||
2146 !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
2147 bch_request_init() ||
2148 bch_debug_init(bcache_kobj) ||
2149 sysfs_create_files(bcache_kobj, files))
2150 goto err;
2151
2152 return 0;
2153 err:
2154 bcache_exit();
2155 return -ENOMEM;
2156 }
2157
2158 module_exit(bcache_exit);
2159 module_init(bcache_init);
CRIS linux kernel tree