2 * bcache setup/teardown code, and some metadata io - read a superblock and
3 * figure out what to do with it.
5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6 * Copyright 2012 Google, Inc.
13 #include "writeback.h"
15 #include <linux/blkdev.h>
16 #include <linux/buffer_head.h>
17 #include <linux/debugfs.h>
18 #include <linux/genhd.h>
19 #include <linux/idr.h>
20 #include <linux/kthread.h>
21 #include <linux/module.h>
22 #include <linux/random.h>
23 #include <linux/reboot.h>
24 #include <linux/sysfs.h>
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
29 static const char bcache_magic[] = {
30 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
31 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
34 static const char invalid_uuid[] = {
35 0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78,
36 0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99
39 /* Default is -1; we skip past it for struct cached_dev's cache mode */
40 const char * const bch_cache_modes[] = {
49 static struct kobject *bcache_kobj;
50 struct mutex bch_register_lock;
51 LIST_HEAD(bch_cache_sets);
52 static LIST_HEAD(uncached_devices);
54 static int bcache_major;
55 static DEFINE_IDA(bcache_minor);
56 static wait_queue_head_t unregister_wait;
57 struct workqueue_struct *bcache_wq;
59 #define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE)
61 static void bio_split_pool_free(struct bio_split_pool *p)
63 if (p->bio_split_hook)
64 mempool_destroy(p->bio_split_hook);
67 bioset_free(p->bio_split);
70 static int bio_split_pool_init(struct bio_split_pool *p)
72 p->bio_split = bioset_create(4, 0);
76 p->bio_split_hook = mempool_create_kmalloc_pool(4,
77 sizeof(struct bio_split_hook));
78 if (!p->bio_split_hook)
86 static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
91 struct buffer_head *bh = __bread(bdev, 1, SB_SIZE);
97 s = (struct cache_sb *) bh->b_data;
99 sb->offset = le64_to_cpu(s->offset);
100 sb->version = le64_to_cpu(s->version);
102 memcpy(sb->magic, s->magic, 16);
103 memcpy(sb->uuid, s->uuid, 16);
104 memcpy(sb->set_uuid, s->set_uuid, 16);
105 memcpy(sb->label, s->label, SB_LABEL_SIZE);
107 sb->flags = le64_to_cpu(s->flags);
108 sb->seq = le64_to_cpu(s->seq);
109 sb->last_mount = le32_to_cpu(s->last_mount);
110 sb->first_bucket = le16_to_cpu(s->first_bucket);
111 sb->keys = le16_to_cpu(s->keys);
113 for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
114 sb->d[i] = le64_to_cpu(s->d[i]);
116 pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
117 sb->version, sb->flags, sb->seq, sb->keys);
119 err = "Not a bcache superblock";
120 if (sb->offset != SB_SECTOR)
123 if (memcmp(sb->magic, bcache_magic, 16))
126 err = "Too many journal buckets";
127 if (sb->keys > SB_JOURNAL_BUCKETS)
130 err = "Bad checksum";
131 if (s->csum != csum_set(s))
135 if (bch_is_zero(sb->uuid, 16))
138 sb->block_size = le16_to_cpu(s->block_size);
140 err = "Superblock block size smaller than device block size";
141 if (sb->block_size << 9 < bdev_logical_block_size(bdev))
144 switch (sb->version) {
145 case BCACHE_SB_VERSION_BDEV:
146 sb->data_offset = BDEV_DATA_START_DEFAULT;
148 case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
149 sb->data_offset = le64_to_cpu(s->data_offset);
151 err = "Bad data offset";
152 if (sb->data_offset < BDEV_DATA_START_DEFAULT)
156 case BCACHE_SB_VERSION_CDEV:
157 case BCACHE_SB_VERSION_CDEV_WITH_UUID:
158 sb->nbuckets = le64_to_cpu(s->nbuckets);
159 sb->block_size = le16_to_cpu(s->block_size);
160 sb->bucket_size = le16_to_cpu(s->bucket_size);
162 sb->nr_in_set = le16_to_cpu(s->nr_in_set);
163 sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
165 err = "Too many buckets";
166 if (sb->nbuckets > LONG_MAX)
169 err = "Not enough buckets";
170 if (sb->nbuckets < 1 << 7)
173 err = "Bad block/bucket size";
174 if (!is_power_of_2(sb->block_size) ||
175 sb->block_size > PAGE_SECTORS ||
176 !is_power_of_2(sb->bucket_size) ||
177 sb->bucket_size < PAGE_SECTORS)
180 err = "Invalid superblock: device too small";
181 if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
185 if (bch_is_zero(sb->set_uuid, 16))
188 err = "Bad cache device number in set";
189 if (!sb->nr_in_set ||
190 sb->nr_in_set <= sb->nr_this_dev ||
191 sb->nr_in_set > MAX_CACHES_PER_SET)
194 err = "Journal buckets not sequential";
195 for (i = 0; i < sb->keys; i++)
196 if (sb->d[i] != sb->first_bucket + i)
199 err = "Too many journal buckets";
200 if (sb->first_bucket + sb->keys > sb->nbuckets)
203 err = "Invalid superblock: first bucket comes before end of super";
204 if (sb->first_bucket * sb->bucket_size < 16)
209 err = "Unsupported superblock version";
213 sb->last_mount = get_seconds();
216 get_page(bh->b_page);
223 static void write_bdev_super_endio(struct bio *bio, int error)
225 struct cached_dev *dc = bio->bi_private;
226 /* XXX: error checking */
228 closure_put(&dc->sb_write.cl);
231 static void __write_super(struct cache_sb *sb, struct bio *bio)
233 struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
236 bio->bi_sector = SB_SECTOR;
237 bio->bi_rw = REQ_SYNC|REQ_META;
238 bio->bi_size = SB_SIZE;
239 bch_bio_map(bio, NULL);
241 out->offset = cpu_to_le64(sb->offset);
242 out->version = cpu_to_le64(sb->version);
244 memcpy(out->uuid, sb->uuid, 16);
245 memcpy(out->set_uuid, sb->set_uuid, 16);
246 memcpy(out->label, sb->label, SB_LABEL_SIZE);
248 out->flags = cpu_to_le64(sb->flags);
249 out->seq = cpu_to_le64(sb->seq);
251 out->last_mount = cpu_to_le32(sb->last_mount);
252 out->first_bucket = cpu_to_le16(sb->first_bucket);
253 out->keys = cpu_to_le16(sb->keys);
255 for (i = 0; i < sb->keys; i++)
256 out->d[i] = cpu_to_le64(sb->d[i]);
258 out->csum = csum_set(out);
260 pr_debug("ver %llu, flags %llu, seq %llu",
261 sb->version, sb->flags, sb->seq);
263 submit_bio(REQ_WRITE, bio);
266 void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
268 struct closure *cl = &dc->sb_write.cl;
269 struct bio *bio = &dc->sb_bio;
271 closure_lock(&dc->sb_write, parent);
274 bio->bi_bdev = dc->bdev;
275 bio->bi_end_io = write_bdev_super_endio;
276 bio->bi_private = dc;
279 __write_super(&dc->sb, bio);
284 static void write_super_endio(struct bio *bio, int error)
286 struct cache *ca = bio->bi_private;
288 bch_count_io_errors(ca, error, "writing superblock");
289 closure_put(&ca->set->sb_write.cl);
292 void bcache_write_super(struct cache_set *c)
294 struct closure *cl = &c->sb_write.cl;
298 closure_lock(&c->sb_write, &c->cl);
302 for_each_cache(ca, c, i) {
303 struct bio *bio = &ca->sb_bio;
305 ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
306 ca->sb.seq = c->sb.seq;
307 ca->sb.last_mount = c->sb.last_mount;
309 SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb));
312 bio->bi_bdev = ca->bdev;
313 bio->bi_end_io = write_super_endio;
314 bio->bi_private = ca;
317 __write_super(&ca->sb, bio);
325 static void uuid_endio(struct bio *bio, int error)
327 struct closure *cl = bio->bi_private;
328 struct cache_set *c = container_of(cl, struct cache_set, uuid_write.cl);
330 cache_set_err_on(error, c, "accessing uuids");
331 bch_bbio_free(bio, c);
335 static void uuid_io(struct cache_set *c, unsigned long rw,
336 struct bkey *k, struct closure *parent)
338 struct closure *cl = &c->uuid_write.cl;
339 struct uuid_entry *u;
344 closure_lock(&c->uuid_write, parent);
346 for (i = 0; i < KEY_PTRS(k); i++) {
347 struct bio *bio = bch_bbio_alloc(c);
349 bio->bi_rw = REQ_SYNC|REQ_META|rw;
350 bio->bi_size = KEY_SIZE(k) << 9;
352 bio->bi_end_io = uuid_endio;
353 bio->bi_private = cl;
354 bch_bio_map(bio, c->uuids);
356 bch_submit_bbio(bio, c, k, i);
362 bch_bkey_to_text(buf, sizeof(buf), k);
363 pr_debug("%s UUIDs at %s", rw & REQ_WRITE ? "wrote" : "read", buf);
365 for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
366 if (!bch_is_zero(u->uuid, 16))
367 pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
368 u - c->uuids, u->uuid, u->label,
369 u->first_reg, u->last_reg, u->invalidated);
374 static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
376 struct bkey *k = &j->uuid_bucket;
378 if (bch_btree_ptr_invalid(c, k))
379 return "bad uuid pointer";
381 bkey_copy(&c->uuid_bucket, k);
382 uuid_io(c, READ_SYNC, k, cl);
384 if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
385 struct uuid_entry_v0 *u0 = (void *) c->uuids;
386 struct uuid_entry *u1 = (void *) c->uuids;
392 * Since the new uuid entry is bigger than the old, we have to
393 * convert starting at the highest memory address and work down
394 * in order to do it in place
397 for (i = c->nr_uuids - 1;
400 memcpy(u1[i].uuid, u0[i].uuid, 16);
401 memcpy(u1[i].label, u0[i].label, 32);
403 u1[i].first_reg = u0[i].first_reg;
404 u1[i].last_reg = u0[i].last_reg;
405 u1[i].invalidated = u0[i].invalidated;
415 static int __uuid_write(struct cache_set *c)
419 closure_init_stack(&cl);
421 lockdep_assert_held(&bch_register_lock);
423 if (bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, true))
426 SET_KEY_SIZE(&k.key, c->sb.bucket_size);
427 uuid_io(c, REQ_WRITE, &k.key, &cl);
430 bkey_copy(&c->uuid_bucket, &k.key);
435 int bch_uuid_write(struct cache_set *c)
437 int ret = __uuid_write(c);
440 bch_journal_meta(c, NULL);
445 static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
447 struct uuid_entry *u;
450 u < c->uuids + c->nr_uuids; u++)
451 if (!memcmp(u->uuid, uuid, 16))
457 static struct uuid_entry *uuid_find_empty(struct cache_set *c)
459 static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
460 return uuid_find(c, zero_uuid);
464 * Bucket priorities/gens:
466 * For each bucket, we store on disk its
470 * See alloc.c for an explanation of the gen. The priority is used to implement
471 * lru (and in the future other) cache replacement policies; for most purposes
472 * it's just an opaque integer.
474 * The gens and the priorities don't have a whole lot to do with each other, and
475 * it's actually the gens that must be written out at specific times - it's no
476 * big deal if the priorities don't get written, if we lose them we just reuse
477 * buckets in suboptimal order.
479 * On disk they're stored in a packed array, and in as many buckets are required
480 * to fit them all. The buckets we use to store them form a list; the journal
481 * header points to the first bucket, the first bucket points to the second
484 * This code is used by the allocation code; periodically (whenever it runs out
485 * of buckets to allocate from) the allocation code will invalidate some
486 * buckets, but it can't use those buckets until their new gens are safely on
490 static void prio_endio(struct bio *bio, int error)
492 struct cache *ca = bio->bi_private;
494 cache_set_err_on(error, ca->set, "accessing priorities");
495 bch_bbio_free(bio, ca->set);
496 closure_put(&ca->prio);
499 static void prio_io(struct cache *ca, uint64_t bucket, unsigned long rw)
501 struct closure *cl = &ca->prio;
502 struct bio *bio = bch_bbio_alloc(ca->set);
504 closure_init_stack(cl);
506 bio->bi_sector = bucket * ca->sb.bucket_size;
507 bio->bi_bdev = ca->bdev;
508 bio->bi_rw = REQ_SYNC|REQ_META|rw;
509 bio->bi_size = bucket_bytes(ca);
511 bio->bi_end_io = prio_endio;
512 bio->bi_private = ca;
513 bch_bio_map(bio, ca->disk_buckets);
515 closure_bio_submit(bio, &ca->prio, ca);
519 #define buckets_free(c) "free %zu, free_inc %zu, unused %zu", \
520 fifo_used(&c->free), fifo_used(&c->free_inc), fifo_used(&c->unused)
522 void bch_prio_write(struct cache *ca)
528 closure_init_stack(&cl);
530 lockdep_assert_held(&ca->set->bucket_lock);
532 for (b = ca->buckets;
533 b < ca->buckets + ca->sb.nbuckets; b++)
534 b->disk_gen = b->gen;
536 ca->disk_buckets->seq++;
538 atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
539 &ca->meta_sectors_written);
541 pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free),
542 fifo_used(&ca->free_inc), fifo_used(&ca->unused));
544 for (i = prio_buckets(ca) - 1; i >= 0; --i) {
546 struct prio_set *p = ca->disk_buckets;
547 struct bucket_disk *d = p->data;
548 struct bucket_disk *end = d + prios_per_bucket(ca);
550 for (b = ca->buckets + i * prios_per_bucket(ca);
551 b < ca->buckets + ca->sb.nbuckets && d < end;
553 d->prio = cpu_to_le16(b->prio);
557 p->next_bucket = ca->prio_buckets[i + 1];
558 p->magic = pset_magic(&ca->sb);
559 p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8);
561 bucket = bch_bucket_alloc(ca, WATERMARK_PRIO, true);
562 BUG_ON(bucket == -1);
564 mutex_unlock(&ca->set->bucket_lock);
565 prio_io(ca, bucket, REQ_WRITE);
566 mutex_lock(&ca->set->bucket_lock);
568 ca->prio_buckets[i] = bucket;
569 atomic_dec_bug(&ca->buckets[bucket].pin);
572 mutex_unlock(&ca->set->bucket_lock);
574 bch_journal_meta(ca->set, &cl);
577 mutex_lock(&ca->set->bucket_lock);
579 ca->need_save_prio = 0;
582 * Don't want the old priorities to get garbage collected until after we
583 * finish writing the new ones, and they're journalled
585 for (i = 0; i < prio_buckets(ca); i++)
586 ca->prio_last_buckets[i] = ca->prio_buckets[i];
589 static void prio_read(struct cache *ca, uint64_t bucket)
591 struct prio_set *p = ca->disk_buckets;
592 struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
594 unsigned bucket_nr = 0;
596 for (b = ca->buckets;
597 b < ca->buckets + ca->sb.nbuckets;
600 ca->prio_buckets[bucket_nr] = bucket;
601 ca->prio_last_buckets[bucket_nr] = bucket;
604 prio_io(ca, bucket, READ_SYNC);
606 if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8))
607 pr_warn("bad csum reading priorities");
609 if (p->magic != pset_magic(&ca->sb))
610 pr_warn("bad magic reading priorities");
612 bucket = p->next_bucket;
616 b->prio = le16_to_cpu(d->prio);
617 b->gen = b->disk_gen = b->last_gc = b->gc_gen = d->gen;
623 static int open_dev(struct block_device *b, fmode_t mode)
625 struct bcache_device *d = b->bd_disk->private_data;
626 if (test_bit(BCACHE_DEV_CLOSING, &d->flags))
633 static void release_dev(struct gendisk *b, fmode_t mode)
635 struct bcache_device *d = b->private_data;
639 static int ioctl_dev(struct block_device *b, fmode_t mode,
640 unsigned int cmd, unsigned long arg)
642 struct bcache_device *d = b->bd_disk->private_data;
643 return d->ioctl(d, mode, cmd, arg);
646 static const struct block_device_operations bcache_ops = {
648 .release = release_dev,
650 .owner = THIS_MODULE,
653 void bcache_device_stop(struct bcache_device *d)
655 if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags))
656 closure_queue(&d->cl);
659 static void bcache_device_unlink(struct bcache_device *d)
661 lockdep_assert_held(&bch_register_lock);
663 if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) {
667 sysfs_remove_link(&d->c->kobj, d->name);
668 sysfs_remove_link(&d->kobj, "cache");
670 for_each_cache(ca, d->c, i)
671 bd_unlink_disk_holder(ca->bdev, d->disk);
675 static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
681 for_each_cache(ca, d->c, i)
682 bd_link_disk_holder(ca->bdev, d->disk);
684 snprintf(d->name, BCACHEDEVNAME_SIZE,
685 "%s%u", name, d->id);
687 WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
688 sysfs_create_link(&c->kobj, &d->kobj, d->name),
689 "Couldn't create device <-> cache set symlinks");
692 static void bcache_device_detach(struct bcache_device *d)
694 lockdep_assert_held(&bch_register_lock);
696 if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) {
697 struct uuid_entry *u = d->c->uuids + d->id;
699 SET_UUID_FLASH_ONLY(u, 0);
700 memcpy(u->uuid, invalid_uuid, 16);
701 u->invalidated = cpu_to_le32(get_seconds());
702 bch_uuid_write(d->c);
705 bcache_device_unlink(d);
707 d->c->devices[d->id] = NULL;
708 closure_put(&d->c->caching);
712 static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
715 BUG_ON(test_bit(CACHE_SET_STOPPING, &c->flags));
721 closure_get(&c->caching);
724 static void bcache_device_free(struct bcache_device *d)
726 lockdep_assert_held(&bch_register_lock);
728 pr_info("%s stopped", d->disk->disk_name);
731 bcache_device_detach(d);
732 if (d->disk && d->disk->flags & GENHD_FL_UP)
733 del_gendisk(d->disk);
734 if (d->disk && d->disk->queue)
735 blk_cleanup_queue(d->disk->queue);
737 ida_simple_remove(&bcache_minor, d->disk->first_minor);
741 bio_split_pool_free(&d->bio_split_hook);
743 bioset_free(d->bio_split);
744 if (is_vmalloc_addr(d->full_dirty_stripes))
745 vfree(d->full_dirty_stripes);
747 kfree(d->full_dirty_stripes);
748 if (is_vmalloc_addr(d->stripe_sectors_dirty))
749 vfree(d->stripe_sectors_dirty);
751 kfree(d->stripe_sectors_dirty);
753 closure_debug_destroy(&d->cl);
756 static int bcache_device_init(struct bcache_device *d, unsigned block_size,
759 struct request_queue *q;
764 d->stripe_size = 1 << 31;
766 d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
768 if (!d->nr_stripes ||
769 d->nr_stripes > INT_MAX ||
770 d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
771 pr_err("nr_stripes too large");
775 n = d->nr_stripes * sizeof(atomic_t);
776 d->stripe_sectors_dirty = n < PAGE_SIZE << 6
777 ? kzalloc(n, GFP_KERNEL)
779 if (!d->stripe_sectors_dirty)
782 n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long);
783 d->full_dirty_stripes = n < PAGE_SIZE << 6
784 ? kzalloc(n, GFP_KERNEL)
786 if (!d->full_dirty_stripes)
789 minor = ida_simple_get(&bcache_minor, 0, MINORMASK + 1, GFP_KERNEL);
793 if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
794 bio_split_pool_init(&d->bio_split_hook) ||
795 !(d->disk = alloc_disk(1))) {
796 ida_simple_remove(&bcache_minor, minor);
800 set_capacity(d->disk, sectors);
801 snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", minor);
803 d->disk->major = bcache_major;
804 d->disk->first_minor = minor;
805 d->disk->fops = &bcache_ops;
806 d->disk->private_data = d;
808 q = blk_alloc_queue(GFP_KERNEL);
812 blk_queue_make_request(q, NULL);
815 q->backing_dev_info.congested_data = d;
816 q->limits.max_hw_sectors = UINT_MAX;
817 q->limits.max_sectors = UINT_MAX;
818 q->limits.max_segment_size = UINT_MAX;
819 q->limits.max_segments = BIO_MAX_PAGES;
820 q->limits.max_discard_sectors = UINT_MAX;
821 q->limits.io_min = block_size;
822 q->limits.logical_block_size = block_size;
823 q->limits.physical_block_size = block_size;
824 set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags);
825 set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags);
827 blk_queue_flush(q, REQ_FLUSH|REQ_FUA);
834 static void calc_cached_dev_sectors(struct cache_set *c)
836 uint64_t sectors = 0;
837 struct cached_dev *dc;
839 list_for_each_entry(dc, &c->cached_devs, list)
840 sectors += bdev_sectors(dc->bdev);
842 c->cached_dev_sectors = sectors;
845 void bch_cached_dev_run(struct cached_dev *dc)
847 struct bcache_device *d = &dc->disk;
848 char buf[SB_LABEL_SIZE + 1];
851 kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid),
856 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
857 buf[SB_LABEL_SIZE] = '\0';
858 env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf);
860 if (atomic_xchg(&dc->running, 1))
864 BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
866 closure_init_stack(&cl);
868 SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
869 bch_write_bdev_super(dc, &cl);
874 bd_link_disk_holder(dc->bdev, dc->disk.disk);
875 /* won't show up in the uevent file, use udevadm monitor -e instead
876 * only class / kset properties are persistent */
877 kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
881 if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
882 sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache"))
883 pr_debug("error creating sysfs link");
886 static void cached_dev_detach_finish(struct work_struct *w)
888 struct cached_dev *dc = container_of(w, struct cached_dev, detach);
889 char buf[BDEVNAME_SIZE];
891 closure_init_stack(&cl);
893 BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags));
894 BUG_ON(atomic_read(&dc->count));
896 mutex_lock(&bch_register_lock);
898 memset(&dc->sb.set_uuid, 0, 16);
899 SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
901 bch_write_bdev_super(dc, &cl);
904 bcache_device_detach(&dc->disk);
905 list_move(&dc->list, &uncached_devices);
907 clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags);
909 mutex_unlock(&bch_register_lock);
911 pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
913 /* Drop ref we took in cached_dev_detach() */
914 closure_put(&dc->disk.cl);
917 void bch_cached_dev_detach(struct cached_dev *dc)
919 lockdep_assert_held(&bch_register_lock);
921 if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags))
924 if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags))
928 * Block the device from being closed and freed until we're finished
931 closure_get(&dc->disk.cl);
933 bch_writeback_queue(dc);
937 int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c)
939 uint32_t rtime = cpu_to_le32(get_seconds());
940 struct uuid_entry *u;
941 char buf[BDEVNAME_SIZE];
943 bdevname(dc->bdev, buf);
945 if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16))
949 pr_err("Can't attach %s: already attached", buf);
953 if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
954 pr_err("Can't attach %s: shutting down", buf);
958 if (dc->sb.block_size < c->sb.block_size) {
960 pr_err("Couldn't attach %s: block size less than set's block size",
965 u = uuid_find(c, dc->sb.uuid);
968 (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
969 BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
970 memcpy(u->uuid, invalid_uuid, 16);
971 u->invalidated = cpu_to_le32(get_seconds());
976 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
977 pr_err("Couldn't find uuid for %s in set", buf);
981 u = uuid_find_empty(c);
983 pr_err("Not caching %s, no room for UUID", buf);
988 /* Deadlocks since we're called via sysfs...
989 sysfs_remove_file(&dc->kobj, &sysfs_attach);
992 if (bch_is_zero(u->uuid, 16)) {
994 closure_init_stack(&cl);
996 memcpy(u->uuid, dc->sb.uuid, 16);
997 memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
998 u->first_reg = u->last_reg = rtime;
1001 memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
1002 SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
1004 bch_write_bdev_super(dc, &cl);
1007 u->last_reg = rtime;
1011 bcache_device_attach(&dc->disk, c, u - c->uuids);
1012 list_move(&dc->list, &c->cached_devs);
1013 calc_cached_dev_sectors(c);
1017 * dc->c must be set before dc->count != 0 - paired with the mb in
1020 atomic_set(&dc->count, 1);
1022 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
1023 bch_sectors_dirty_init(dc);
1024 atomic_set(&dc->has_dirty, 1);
1025 atomic_inc(&dc->count);
1026 bch_writeback_queue(dc);
1029 bch_cached_dev_run(dc);
1030 bcache_device_link(&dc->disk, c, "bdev");
1032 pr_info("Caching %s as %s on set %pU",
1033 bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
1034 dc->disk.c->sb.set_uuid);
1038 void bch_cached_dev_release(struct kobject *kobj)
1040 struct cached_dev *dc = container_of(kobj, struct cached_dev,
1043 module_put(THIS_MODULE);
1046 static void cached_dev_free(struct closure *cl)
1048 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1050 cancel_delayed_work_sync(&dc->writeback_rate_update);
1051 kthread_stop(dc->writeback_thread);
1053 mutex_lock(&bch_register_lock);
1055 if (atomic_read(&dc->running))
1056 bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
1057 bcache_device_free(&dc->disk);
1058 list_del(&dc->list);
1060 mutex_unlock(&bch_register_lock);
1062 if (!IS_ERR_OR_NULL(dc->bdev)) {
1063 if (dc->bdev->bd_disk)
1064 blk_sync_queue(bdev_get_queue(dc->bdev));
1066 blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1069 wake_up(&unregister_wait);
1071 kobject_put(&dc->disk.kobj);
1074 static void cached_dev_flush(struct closure *cl)
1076 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1077 struct bcache_device *d = &dc->disk;
1079 mutex_lock(&bch_register_lock);
1080 bcache_device_unlink(d);
1081 mutex_unlock(&bch_register_lock);
1083 bch_cache_accounting_destroy(&dc->accounting);
1084 kobject_del(&d->kobj);
1086 continue_at(cl, cached_dev_free, system_wq);
1089 static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
1093 struct request_queue *q = bdev_get_queue(dc->bdev);
1095 __module_get(THIS_MODULE);
1096 INIT_LIST_HEAD(&dc->list);
1097 closure_init(&dc->disk.cl, NULL);
1098 set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
1099 kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
1100 INIT_WORK(&dc->detach, cached_dev_detach_finish);
1101 closure_init_unlocked(&dc->sb_write);
1102 INIT_LIST_HEAD(&dc->io_lru);
1103 spin_lock_init(&dc->io_lock);
1104 bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
1106 dc->sequential_cutoff = 4 << 20;
1108 for (io = dc->io; io < dc->io + RECENT_IO; io++) {
1109 list_add(&io->lru, &dc->io_lru);
1110 hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
1113 ret = bcache_device_init(&dc->disk, block_size,
1114 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1118 set_capacity(dc->disk.disk,
1119 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1121 dc->disk.disk->queue->backing_dev_info.ra_pages =
1122 max(dc->disk.disk->queue->backing_dev_info.ra_pages,
1123 q->backing_dev_info.ra_pages);
1125 bch_cached_dev_request_init(dc);
1126 bch_cached_dev_writeback_init(dc);
1130 /* Cached device - bcache superblock */
1132 static void register_bdev(struct cache_sb *sb, struct page *sb_page,
1133 struct block_device *bdev,
1134 struct cached_dev *dc)
1136 char name[BDEVNAME_SIZE];
1137 const char *err = "cannot allocate memory";
1138 struct cache_set *c;
1140 memcpy(&dc->sb, sb, sizeof(struct cache_sb));
1142 dc->bdev->bd_holder = dc;
1144 bio_init(&dc->sb_bio);
1145 dc->sb_bio.bi_max_vecs = 1;
1146 dc->sb_bio.bi_io_vec = dc->sb_bio.bi_inline_vecs;
1147 dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
1150 if (cached_dev_init(dc, sb->block_size << 9))
1153 err = "error creating kobject";
1154 if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
1157 if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
1160 pr_info("registered backing device %s", bdevname(bdev, name));
1162 list_add(&dc->list, &uncached_devices);
1163 list_for_each_entry(c, &bch_cache_sets, list)
1164 bch_cached_dev_attach(dc, c);
1166 if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
1167 BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
1168 bch_cached_dev_run(dc);
1172 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1173 bcache_device_stop(&dc->disk);
1176 /* Flash only volumes */
1178 void bch_flash_dev_release(struct kobject *kobj)
1180 struct bcache_device *d = container_of(kobj, struct bcache_device,
1185 static void flash_dev_free(struct closure *cl)
1187 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1188 bcache_device_free(d);
1189 kobject_put(&d->kobj);
1192 static void flash_dev_flush(struct closure *cl)
1194 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1196 bcache_device_unlink(d);
1197 kobject_del(&d->kobj);
1198 continue_at(cl, flash_dev_free, system_wq);
1201 static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
1203 struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
1208 closure_init(&d->cl, NULL);
1209 set_closure_fn(&d->cl, flash_dev_flush, system_wq);
1211 kobject_init(&d->kobj, &bch_flash_dev_ktype);
1213 if (bcache_device_init(d, block_bytes(c), u->sectors))
1216 bcache_device_attach(d, c, u - c->uuids);
1217 bch_flash_dev_request_init(d);
1220 if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache"))
1223 bcache_device_link(d, c, "volume");
1227 kobject_put(&d->kobj);
1231 static int flash_devs_run(struct cache_set *c)
1234 struct uuid_entry *u;
1237 u < c->uuids + c->nr_uuids && !ret;
1239 if (UUID_FLASH_ONLY(u))
1240 ret = flash_dev_run(c, u);
1245 int bch_flash_dev_create(struct cache_set *c, uint64_t size)
1247 struct uuid_entry *u;
1249 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1252 u = uuid_find_empty(c);
1254 pr_err("Can't create volume, no room for UUID");
1258 get_random_bytes(u->uuid, 16);
1259 memset(u->label, 0, 32);
1260 u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
1262 SET_UUID_FLASH_ONLY(u, 1);
1263 u->sectors = size >> 9;
1267 return flash_dev_run(c, u);
1273 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
1277 if (c->on_error != ON_ERROR_PANIC &&
1278 test_bit(CACHE_SET_STOPPING, &c->flags))
1281 /* XXX: we can be called from atomic context
1282 acquire_console_sem();
1285 printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid);
1287 va_start(args, fmt);
1291 printk(", disabling caching\n");
1293 if (c->on_error == ON_ERROR_PANIC)
1294 panic("panic forced after error\n");
1296 bch_cache_set_unregister(c);
1300 void bch_cache_set_release(struct kobject *kobj)
1302 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
1304 module_put(THIS_MODULE);
1307 static void cache_set_free(struct closure *cl)
1309 struct cache_set *c = container_of(cl, struct cache_set, cl);
1313 if (!IS_ERR_OR_NULL(c->debug))
1314 debugfs_remove(c->debug);
1316 bch_open_buckets_free(c);
1317 bch_btree_cache_free(c);
1318 bch_journal_free(c);
1320 for_each_cache(ca, c, i)
1322 kobject_put(&ca->kobj);
1324 free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
1325 free_pages((unsigned long) c->sort, ilog2(bucket_pages(c)));
1328 bioset_free(c->bio_split);
1330 mempool_destroy(c->fill_iter);
1332 mempool_destroy(c->bio_meta);
1334 mempool_destroy(c->search);
1337 mutex_lock(&bch_register_lock);
1339 mutex_unlock(&bch_register_lock);
1341 pr_info("Cache set %pU unregistered", c->sb.set_uuid);
1342 wake_up(&unregister_wait);
1344 closure_debug_destroy(&c->cl);
1345 kobject_put(&c->kobj);
1348 static void cache_set_flush(struct closure *cl)
1350 struct cache_set *c = container_of(cl, struct cache_set, caching);
1355 bch_cache_accounting_destroy(&c->accounting);
1357 kobject_put(&c->internal);
1358 kobject_del(&c->kobj);
1361 kthread_stop(c->gc_thread);
1363 if (!IS_ERR_OR_NULL(c->root))
1364 list_add(&c->root->list, &c->btree_cache);
1366 /* Should skip this if we're unregistering because of an error */
1367 list_for_each_entry(b, &c->btree_cache, list)
1368 if (btree_node_dirty(b))
1369 bch_btree_node_write(b, NULL);
1371 for_each_cache(ca, c, i)
1372 if (ca->alloc_thread)
1373 kthread_stop(ca->alloc_thread);
1378 static void __cache_set_unregister(struct closure *cl)
1380 struct cache_set *c = container_of(cl, struct cache_set, caching);
1381 struct cached_dev *dc;
1384 mutex_lock(&bch_register_lock);
1386 for (i = 0; i < c->nr_uuids; i++)
1387 if (c->devices[i]) {
1388 if (!UUID_FLASH_ONLY(&c->uuids[i]) &&
1389 test_bit(CACHE_SET_UNREGISTERING, &c->flags)) {
1390 dc = container_of(c->devices[i],
1391 struct cached_dev, disk);
1392 bch_cached_dev_detach(dc);
1394 bcache_device_stop(c->devices[i]);
1398 mutex_unlock(&bch_register_lock);
1400 continue_at(cl, cache_set_flush, system_wq);
1403 void bch_cache_set_stop(struct cache_set *c)
1405 if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
1406 closure_queue(&c->caching);
1409 void bch_cache_set_unregister(struct cache_set *c)
1411 set_bit(CACHE_SET_UNREGISTERING, &c->flags);
1412 bch_cache_set_stop(c);
1415 #define alloc_bucket_pages(gfp, c) \
1416 ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c))))
1418 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1421 struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
1425 __module_get(THIS_MODULE);
1426 closure_init(&c->cl, NULL);
1427 set_closure_fn(&c->cl, cache_set_free, system_wq);
1429 closure_init(&c->caching, &c->cl);
1430 set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
1432 /* Maybe create continue_at_noreturn() and use it here? */
1433 closure_set_stopped(&c->cl);
1434 closure_put(&c->cl);
1436 kobject_init(&c->kobj, &bch_cache_set_ktype);
1437 kobject_init(&c->internal, &bch_cache_set_internal_ktype);
1439 bch_cache_accounting_init(&c->accounting, &c->cl);
1441 memcpy(c->sb.set_uuid, sb->set_uuid, 16);
1442 c->sb.block_size = sb->block_size;
1443 c->sb.bucket_size = sb->bucket_size;
1444 c->sb.nr_in_set = sb->nr_in_set;
1445 c->sb.last_mount = sb->last_mount;
1446 c->bucket_bits = ilog2(sb->bucket_size);
1447 c->block_bits = ilog2(sb->block_size);
1448 c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
1450 c->btree_pages = c->sb.bucket_size / PAGE_SECTORS;
1451 if (c->btree_pages > BTREE_MAX_PAGES)
1452 c->btree_pages = max_t(int, c->btree_pages / 4,
1455 c->sort_crit_factor = int_sqrt(c->btree_pages);
1457 closure_init_unlocked(&c->sb_write);
1458 mutex_init(&c->bucket_lock);
1459 init_waitqueue_head(&c->try_wait);
1460 init_waitqueue_head(&c->bucket_wait);
1461 closure_init_unlocked(&c->uuid_write);
1462 mutex_init(&c->sort_lock);
1464 spin_lock_init(&c->sort_time.lock);
1465 spin_lock_init(&c->btree_gc_time.lock);
1466 spin_lock_init(&c->btree_split_time.lock);
1467 spin_lock_init(&c->btree_read_time.lock);
1468 spin_lock_init(&c->try_harder_time.lock);
1470 bch_moving_init_cache_set(c);
1472 INIT_LIST_HEAD(&c->list);
1473 INIT_LIST_HEAD(&c->cached_devs);
1474 INIT_LIST_HEAD(&c->btree_cache);
1475 INIT_LIST_HEAD(&c->btree_cache_freeable);
1476 INIT_LIST_HEAD(&c->btree_cache_freed);
1477 INIT_LIST_HEAD(&c->data_buckets);
1479 c->search = mempool_create_slab_pool(32, bch_search_cache);
1483 iter_size = (sb->bucket_size / sb->block_size + 1) *
1484 sizeof(struct btree_iter_set);
1486 if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) ||
1487 !(c->bio_meta = mempool_create_kmalloc_pool(2,
1488 sizeof(struct bbio) + sizeof(struct bio_vec) *
1489 bucket_pages(c))) ||
1490 !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
1491 !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
1492 !(c->sort = alloc_bucket_pages(GFP_KERNEL, c)) ||
1493 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1494 bch_journal_alloc(c) ||
1495 bch_btree_cache_alloc(c) ||
1496 bch_open_buckets_alloc(c))
1499 c->congested_read_threshold_us = 2000;
1500 c->congested_write_threshold_us = 20000;
1501 c->error_limit = 8 << IO_ERROR_SHIFT;
1505 bch_cache_set_unregister(c);
1509 static void run_cache_set(struct cache_set *c)
1511 const char *err = "cannot allocate memory";
1512 struct cached_dev *dc, *t;
1517 closure_init_stack(&cl);
1519 for_each_cache(ca, c, i)
1520 c->nbuckets += ca->sb.nbuckets;
1522 if (CACHE_SYNC(&c->sb)) {
1527 err = "cannot allocate memory for journal";
1528 if (bch_journal_read(c, &journal))
1531 pr_debug("btree_journal_read() done");
1533 err = "no journal entries found";
1534 if (list_empty(&journal))
1537 j = &list_entry(journal.prev, struct journal_replay, list)->j;
1539 err = "IO error reading priorities";
1540 for_each_cache(ca, c, i)
1541 prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]);
1544 * If prio_read() fails it'll call cache_set_error and we'll
1545 * tear everything down right away, but if we perhaps checked
1546 * sooner we could avoid journal replay.
1551 err = "bad btree root";
1552 if (bch_btree_ptr_invalid(c, k))
1555 err = "error reading btree root";
1556 c->root = bch_btree_node_get(c, k, j->btree_level, true);
1557 if (IS_ERR_OR_NULL(c->root))
1560 list_del_init(&c->root->list);
1561 rw_unlock(true, c->root);
1563 err = uuid_read(c, j, &cl);
1567 err = "error in recovery";
1568 if (bch_btree_check(c))
1571 bch_journal_mark(c, &journal);
1572 bch_btree_gc_finish(c);
1573 pr_debug("btree_check() done");
1576 * bcache_journal_next() can't happen sooner, or
1577 * btree_gc_finish() will give spurious errors about last_gc >
1578 * gc_gen - this is a hack but oh well.
1580 bch_journal_next(&c->journal);
1582 err = "error starting allocator thread";
1583 for_each_cache(ca, c, i)
1584 if (bch_cache_allocator_start(ca))
1588 * First place it's safe to allocate: btree_check() and
1589 * btree_gc_finish() have to run before we have buckets to
1590 * allocate, and bch_bucket_alloc_set() might cause a journal
1591 * entry to be written so bcache_journal_next() has to be called
1594 * If the uuids were in the old format we have to rewrite them
1595 * before the next journal entry is written:
1597 if (j->version < BCACHE_JSET_VERSION_UUID)
1600 bch_journal_replay(c, &journal);
1602 pr_notice("invalidating existing data");
1604 for_each_cache(ca, c, i) {
1607 ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
1608 2, SB_JOURNAL_BUCKETS);
1610 for (j = 0; j < ca->sb.keys; j++)
1611 ca->sb.d[j] = ca->sb.first_bucket + j;
1614 bch_btree_gc_finish(c);
1616 err = "error starting allocator thread";
1617 for_each_cache(ca, c, i)
1618 if (bch_cache_allocator_start(ca))
1621 mutex_lock(&c->bucket_lock);
1622 for_each_cache(ca, c, i)
1624 mutex_unlock(&c->bucket_lock);
1626 err = "cannot allocate new UUID bucket";
1627 if (__uuid_write(c))
1630 err = "cannot allocate new btree root";
1631 c->root = bch_btree_node_alloc(c, 0, true);
1632 if (IS_ERR_OR_NULL(c->root))
1635 bkey_copy_key(&c->root->key, &MAX_KEY);
1636 bch_btree_node_write(c->root, &cl);
1638 bch_btree_set_root(c->root);
1639 rw_unlock(true, c->root);
1642 * We don't want to write the first journal entry until
1643 * everything is set up - fortunately journal entries won't be
1644 * written until the SET_CACHE_SYNC() here:
1646 SET_CACHE_SYNC(&c->sb, true);
1648 bch_journal_next(&c->journal);
1649 bch_journal_meta(c, &cl);
1652 err = "error starting gc thread";
1653 if (bch_gc_thread_start(c))
1657 c->sb.last_mount = get_seconds();
1658 bcache_write_super(c);
1660 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1661 bch_cached_dev_attach(dc, c);
1668 /* XXX: test this, it's broken */
1669 bch_cache_set_error(c, "%s", err);
1672 static bool can_attach_cache(struct cache *ca, struct cache_set *c)
1674 return ca->sb.block_size == c->sb.block_size &&
1675 ca->sb.bucket_size == c->sb.block_size &&
1676 ca->sb.nr_in_set == c->sb.nr_in_set;
1679 static const char *register_cache_set(struct cache *ca)
1682 const char *err = "cannot allocate memory";
1683 struct cache_set *c;
1685 list_for_each_entry(c, &bch_cache_sets, list)
1686 if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
1687 if (c->cache[ca->sb.nr_this_dev])
1688 return "duplicate cache set member";
1690 if (!can_attach_cache(ca, c))
1691 return "cache sb does not match set";
1693 if (!CACHE_SYNC(&ca->sb))
1694 SET_CACHE_SYNC(&c->sb, false);
1699 c = bch_cache_set_alloc(&ca->sb);
1703 err = "error creating kobject";
1704 if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
1705 kobject_add(&c->internal, &c->kobj, "internal"))
1708 if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
1711 bch_debug_init_cache_set(c);
1713 list_add(&c->list, &bch_cache_sets);
1715 sprintf(buf, "cache%i", ca->sb.nr_this_dev);
1716 if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
1717 sysfs_create_link(&c->kobj, &ca->kobj, buf))
1720 if (ca->sb.seq > c->sb.seq) {
1721 c->sb.version = ca->sb.version;
1722 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
1723 c->sb.flags = ca->sb.flags;
1724 c->sb.seq = ca->sb.seq;
1725 pr_debug("set version = %llu", c->sb.version);
1729 ca->set->cache[ca->sb.nr_this_dev] = ca;
1730 c->cache_by_alloc[c->caches_loaded++] = ca;
1732 if (c->caches_loaded == c->sb.nr_in_set)
1737 bch_cache_set_unregister(c);
1743 void bch_cache_release(struct kobject *kobj)
1745 struct cache *ca = container_of(kobj, struct cache, kobj);
1748 ca->set->cache[ca->sb.nr_this_dev] = NULL;
1750 bio_split_pool_free(&ca->bio_split_hook);
1752 free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
1753 kfree(ca->prio_buckets);
1756 free_heap(&ca->heap);
1757 free_fifo(&ca->unused);
1758 free_fifo(&ca->free_inc);
1759 free_fifo(&ca->free);
1761 if (ca->sb_bio.bi_inline_vecs[0].bv_page)
1762 put_page(ca->sb_bio.bi_io_vec[0].bv_page);
1764 if (!IS_ERR_OR_NULL(ca->bdev)) {
1765 blk_sync_queue(bdev_get_queue(ca->bdev));
1766 blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1770 module_put(THIS_MODULE);
1773 static int cache_alloc(struct cache_sb *sb, struct cache *ca)
1778 __module_get(THIS_MODULE);
1779 kobject_init(&ca->kobj, &bch_cache_ktype);
1781 bio_init(&ca->journal.bio);
1782 ca->journal.bio.bi_max_vecs = 8;
1783 ca->journal.bio.bi_io_vec = ca->journal.bio.bi_inline_vecs;
1785 free = roundup_pow_of_two(ca->sb.nbuckets) >> 9;
1786 free = max_t(size_t, free, (prio_buckets(ca) + 8) * 2);
1788 if (!init_fifo(&ca->free, free, GFP_KERNEL) ||
1789 !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
1790 !init_fifo(&ca->unused, free << 2, GFP_KERNEL) ||
1791 !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
1792 !(ca->buckets = vzalloc(sizeof(struct bucket) *
1793 ca->sb.nbuckets)) ||
1794 !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
1796 !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)) ||
1797 bio_split_pool_init(&ca->bio_split_hook))
1800 ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
1802 for_each_bucket(b, ca)
1803 atomic_set(&b->pin, 0);
1805 if (bch_cache_allocator_init(ca))
1810 kobject_put(&ca->kobj);
1814 static void register_cache(struct cache_sb *sb, struct page *sb_page,
1815 struct block_device *bdev, struct cache *ca)
1817 char name[BDEVNAME_SIZE];
1818 const char *err = "cannot allocate memory";
1820 memcpy(&ca->sb, sb, sizeof(struct cache_sb));
1822 ca->bdev->bd_holder = ca;
1824 bio_init(&ca->sb_bio);
1825 ca->sb_bio.bi_max_vecs = 1;
1826 ca->sb_bio.bi_io_vec = ca->sb_bio.bi_inline_vecs;
1827 ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
1830 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1831 ca->discard = CACHE_DISCARD(&ca->sb);
1833 if (cache_alloc(sb, ca) != 0)
1836 err = "error creating kobject";
1837 if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache"))
1840 err = register_cache_set(ca);
1844 pr_info("registered cache device %s", bdevname(bdev, name));
1847 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1848 kobject_put(&ca->kobj);
1851 /* Global interfaces/init */
1853 static ssize_t register_bcache(struct kobject *, struct kobj_attribute *,
1854 const char *, size_t);
1856 kobj_attribute_write(register, register_bcache);
1857 kobj_attribute_write(register_quiet, register_bcache);
1859 static bool bch_is_open_backing(struct block_device *bdev) {
1860 struct cache_set *c, *tc;
1861 struct cached_dev *dc, *t;
1863 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1864 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1865 if (dc->bdev == bdev)
1867 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1868 if (dc->bdev == bdev)
1873 static bool bch_is_open_cache(struct block_device *bdev) {
1874 struct cache_set *c, *tc;
1878 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1879 for_each_cache(ca, c, i)
1880 if (ca->bdev == bdev)
1885 static bool bch_is_open(struct block_device *bdev) {
1886 return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
1889 static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
1890 const char *buffer, size_t size)
1893 const char *err = "cannot allocate memory";
1895 struct cache_sb *sb = NULL;
1896 struct block_device *bdev = NULL;
1897 struct page *sb_page = NULL;
1899 if (!try_module_get(THIS_MODULE))
1902 mutex_lock(&bch_register_lock);
1904 if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
1905 !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
1908 err = "failed to open device";
1909 bdev = blkdev_get_by_path(strim(path),
1910 FMODE_READ|FMODE_WRITE|FMODE_EXCL,
1913 if (bdev == ERR_PTR(-EBUSY)) {
1914 bdev = lookup_bdev(strim(path));
1915 if (!IS_ERR(bdev) && bch_is_open(bdev))
1916 err = "device already registered";
1918 err = "device busy";
1923 err = "failed to set blocksize";
1924 if (set_blocksize(bdev, 4096))
1927 err = read_super(sb, bdev, &sb_page);
1931 if (SB_IS_BDEV(sb)) {
1932 struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
1936 register_bdev(sb, sb_page, bdev, dc);
1938 struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1942 register_cache(sb, sb_page, bdev, ca);
1949 mutex_unlock(&bch_register_lock);
1950 module_put(THIS_MODULE);
1954 blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1956 if (attr != &ksysfs_register_quiet)
1957 pr_info("error opening %s: %s", path, err);
1962 static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
1964 if (code == SYS_DOWN ||
1966 code == SYS_POWER_OFF) {
1968 unsigned long start = jiffies;
1969 bool stopped = false;
1971 struct cache_set *c, *tc;
1972 struct cached_dev *dc, *tdc;
1974 mutex_lock(&bch_register_lock);
1976 if (list_empty(&bch_cache_sets) &&
1977 list_empty(&uncached_devices))
1980 pr_info("Stopping all devices:");
1982 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1983 bch_cache_set_stop(c);
1985 list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
1986 bcache_device_stop(&dc->disk);
1988 /* What's a condition variable? */
1990 long timeout = start + 2 * HZ - jiffies;
1992 stopped = list_empty(&bch_cache_sets) &&
1993 list_empty(&uncached_devices);
1995 if (timeout < 0 || stopped)
1998 prepare_to_wait(&unregister_wait, &wait,
1999 TASK_UNINTERRUPTIBLE);
2001 mutex_unlock(&bch_register_lock);
2002 schedule_timeout(timeout);
2003 mutex_lock(&bch_register_lock);
2006 finish_wait(&unregister_wait, &wait);
2009 pr_info("All devices stopped");
2011 pr_notice("Timeout waiting for devices to be closed");
2013 mutex_unlock(&bch_register_lock);
2019 static struct notifier_block reboot = {
2020 .notifier_call = bcache_reboot,
2021 .priority = INT_MAX, /* before any real devices */
2024 static void bcache_exit(void)
2030 kobject_put(bcache_kobj);
2032 destroy_workqueue(bcache_wq);
2033 unregister_blkdev(bcache_major, "bcache");
2034 unregister_reboot_notifier(&reboot);
2037 static int __init bcache_init(void)
2039 static const struct attribute *files[] = {
2040 &ksysfs_register.attr,
2041 &ksysfs_register_quiet.attr,
2045 mutex_init(&bch_register_lock);
2046 init_waitqueue_head(&unregister_wait);
2047 register_reboot_notifier(&reboot);
2048 closure_debug_init();
2050 bcache_major = register_blkdev(0, "bcache");
2051 if (bcache_major < 0)
2052 return bcache_major;
2054 if (!(bcache_wq = create_workqueue("bcache")) ||
2055 !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
2056 sysfs_create_files(bcache_kobj, files) ||
2058 bch_request_init() ||
2059 bch_debug_init(bcache_kobj))
2068 module_exit(bcache_exit);
2069 module_init(bcache_init);