| /* |
| * bcache setup/teardown code, and some metadata io - read a superblock and |
| * figure out what to do with it. |
| * |
| * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> |
| * Copyright 2012 Google, Inc. |
| */ |
| |
| #include "bcache.h" |
| #include "btree.h" |
| #include "debug.h" |
| #include "extents.h" |
| #include "request.h" |
| #include "writeback.h" |
| |
| #include <linux/blkdev.h> |
| #include <linux/buffer_head.h> |
| #include <linux/debugfs.h> |
| #include <linux/genhd.h> |
| #include <linux/idr.h> |
| #include <linux/kthread.h> |
| #include <linux/module.h> |
| #include <linux/random.h> |
| #include <linux/reboot.h> |
| #include <linux/sysfs.h> |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>"); |
| |
| static const char bcache_magic[] = { |
| 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca, |
| 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81 |
| }; |
| |
| static const char invalid_uuid[] = { |
| 0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78, |
| 0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99 |
| }; |
| |
| /* Default is -1; we skip past it for struct cached_dev's cache mode */ |
| const char * const bch_cache_modes[] = { |
| "default", |
| "writethrough", |
| "writeback", |
| "writearound", |
| "none", |
| NULL |
| }; |
| |
| static struct kobject *bcache_kobj; |
| struct mutex bch_register_lock; |
| LIST_HEAD(bch_cache_sets); |
| static LIST_HEAD(uncached_devices); |
| |
| static int bcache_major; |
| static DEFINE_IDA(bcache_minor); |
| static wait_queue_head_t unregister_wait; |
| struct workqueue_struct *bcache_wq; |
| |
| #define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE) |
| #define BCACHE_MINORS 16 /* partition support */ |
| |
| /* Superblock */ |
| |
| static const char *read_super(struct cache_sb *sb, struct block_device *bdev, |
| struct page **res) |
| { |
| const char *err; |
| struct cache_sb *s; |
| struct buffer_head *bh = __bread(bdev, 1, SB_SIZE); |
| unsigned i; |
| |
| if (!bh) |
| return "IO error"; |
| |
| s = (struct cache_sb *) bh->b_data; |
| |
| sb->offset = le64_to_cpu(s->offset); |
| sb->version = le64_to_cpu(s->version); |
| |
| memcpy(sb->magic, s->magic, 16); |
| memcpy(sb->uuid, s->uuid, 16); |
| memcpy(sb->set_uuid, s->set_uuid, 16); |
| memcpy(sb->label, s->label, SB_LABEL_SIZE); |
| |
| sb->flags = le64_to_cpu(s->flags); |
| sb->seq = le64_to_cpu(s->seq); |
| sb->last_mount = le32_to_cpu(s->last_mount); |
| sb->first_bucket = le16_to_cpu(s->first_bucket); |
| sb->keys = le16_to_cpu(s->keys); |
| |
| for (i = 0; i < SB_JOURNAL_BUCKETS; i++) |
| sb->d[i] = le64_to_cpu(s->d[i]); |
| |
| pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u", |
| sb->version, sb->flags, sb->seq, sb->keys); |
| |
| err = "Not a bcache superblock"; |
| if (sb->offset != SB_SECTOR) |
| goto err; |
| |
| if (memcmp(sb->magic, bcache_magic, 16)) |
| goto err; |
| |
| err = "Too many journal buckets"; |
| if (sb->keys > SB_JOURNAL_BUCKETS) |
| goto err; |
| |
| err = "Bad checksum"; |
| if (s->csum != csum_set(s)) |
| goto err; |
| |
| err = "Bad UUID"; |
| if (bch_is_zero(sb->uuid, 16)) |
| goto err; |
| |
| sb->block_size = le16_to_cpu(s->block_size); |
| |
| err = "Superblock block size smaller than device block size"; |
| if (sb->block_size << 9 < bdev_logical_block_size(bdev)) |
| goto err; |
| |
| switch (sb->version) { |
| case BCACHE_SB_VERSION_BDEV: |
| sb->data_offset = BDEV_DATA_START_DEFAULT; |
| break; |
| case BCACHE_SB_VERSION_BDEV_WITH_OFFSET: |
| sb->data_offset = le64_to_cpu(s->data_offset); |
| |
| err = "Bad data offset"; |
| if (sb->data_offset < BDEV_DATA_START_DEFAULT) |
| goto err; |
| |
| break; |
| case BCACHE_SB_VERSION_CDEV: |
| case BCACHE_SB_VERSION_CDEV_WITH_UUID: |
| sb->nbuckets = le64_to_cpu(s->nbuckets); |
| sb->bucket_size = le16_to_cpu(s->bucket_size); |
| |
| sb->nr_in_set = le16_to_cpu(s->nr_in_set); |
| sb->nr_this_dev = le16_to_cpu(s->nr_this_dev); |
| |
| err = "Too many buckets"; |
| if (sb->nbuckets > LONG_MAX) |
| goto err; |
| |
| err = "Not enough buckets"; |
| if (sb->nbuckets < 1 << 7) |
| goto err; |
| |
| err = "Bad block/bucket size"; |
| if (!is_power_of_2(sb->block_size) || |
| sb->block_size > PAGE_SECTORS || |
| !is_power_of_2(sb->bucket_size) || |
| sb->bucket_size < PAGE_SECTORS) |
| goto err; |
| |
| err = "Invalid superblock: device too small"; |
| if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets) |
| goto err; |
| |
| err = "Bad UUID"; |
| if (bch_is_zero(sb->set_uuid, 16)) |
| goto err; |
| |
| err = "Bad cache device number in set"; |
| if (!sb->nr_in_set || |
| sb->nr_in_set <= sb->nr_this_dev || |
| sb->nr_in_set > MAX_CACHES_PER_SET) |
| goto err; |
| |
| err = "Journal buckets not sequential"; |
| for (i = 0; i < sb->keys; i++) |
| if (sb->d[i] != sb->first_bucket + i) |
| goto err; |
| |
| err = "Too many journal buckets"; |
| if (sb->first_bucket + sb->keys > sb->nbuckets) |
| goto err; |
| |
| err = "Invalid superblock: first bucket comes before end of super"; |
| if (sb->first_bucket * sb->bucket_size < 16) |
| goto err; |
| |
| break; |
| default: |
| err = "Unsupported superblock version"; |
| goto err; |
| } |
| |
| sb->last_mount = get_seconds(); |
| err = NULL; |
| |
| get_page(bh->b_page); |
| *res = bh->b_page; |
| err: |
| put_bh(bh); |
| return err; |
| } |
| |
| static void write_bdev_super_endio(struct bio *bio) |
| { |
| struct cached_dev *dc = bio->bi_private; |
| /* XXX: error checking */ |
| |
| closure_put(&dc->sb_write); |
| } |
| |
| static void __write_super(struct cache_sb *sb, struct bio *bio) |
| { |
| struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page); |
| unsigned i; |
| |
| bio->bi_iter.bi_sector = SB_SECTOR; |
| bio->bi_iter.bi_size = SB_SIZE; |
| bio_set_op_attrs(bio, REQ_OP_WRITE, REQ_SYNC|REQ_META); |
| bch_bio_map(bio, NULL); |
| |
| out->offset = cpu_to_le64(sb->offset); |
| out->version = cpu_to_le64(sb->version); |
| |
| memcpy(out->uuid, sb->uuid, 16); |
| memcpy(out->set_uuid, sb->set_uuid, 16); |
| memcpy(out->label, sb->label, SB_LABEL_SIZE); |
| |
| out->flags = cpu_to_le64(sb->flags); |
| out->seq = cpu_to_le64(sb->seq); |
| |
| out->last_mount = cpu_to_le32(sb->last_mount); |
| out->first_bucket = cpu_to_le16(sb->first_bucket); |
| out->keys = cpu_to_le16(sb->keys); |
| |
| for (i = 0; i < sb->keys; i++) |
| out->d[i] = cpu_to_le64(sb->d[i]); |
| |
| out->csum = csum_set(out); |
| |
| pr_debug("ver %llu, flags %llu, seq %llu", |
| sb->version, sb->flags, sb->seq); |
| |
| submit_bio(bio); |
| } |
| |
| static void bch_write_bdev_super_unlock(struct closure *cl) |
| { |
| struct cached_dev *dc = container_of(cl, struct cached_dev, sb_write); |
| |
| up(&dc->sb_write_mutex); |
| } |
| |
| void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent) |
| { |
| struct closure *cl = &dc->sb_write; |
| struct bio *bio = &dc->sb_bio; |
| |
| down(&dc->sb_write_mutex); |
| closure_init(cl, parent); |
| |
| bio_reset(bio); |
| bio->bi_bdev = dc->bdev; |
| bio->bi_end_io = write_bdev_super_endio; |
| bio->bi_private = dc; |
| |
| closure_get(cl); |
| __write_super(&dc->sb, bio); |
| |
| closure_return_with_destructor(cl, bch_write_bdev_super_unlock); |
| } |
| |
| static void write_super_endio(struct bio *bio) |
| { |
| struct cache *ca = bio->bi_private; |
| |
| bch_count_io_errors(ca, bio->bi_error, "writing superblock"); |
| closure_put(&ca->set->sb_write); |
| } |
| |
| static void bcache_write_super_unlock(struct closure *cl) |
| { |
| struct cache_set *c = container_of(cl, struct cache_set, sb_write); |
| |
| up(&c->sb_write_mutex); |
| } |
| |
| void bcache_write_super(struct cache_set *c) |
| { |
| struct closure *cl = &c->sb_write; |
| struct cache *ca; |
| unsigned i; |
| |
| down(&c->sb_write_mutex); |
| closure_init(cl, &c->cl); |
| |
| c->sb.seq++; |
| |
| for_each_cache(ca, c, i) { |
| struct bio *bio = &ca->sb_bio; |
| |
| ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID; |
| ca->sb.seq = c->sb.seq; |
| ca->sb.last_mount = c->sb.last_mount; |
| |
| SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb)); |
| |
| bio_reset(bio); |
| bio->bi_bdev = ca->bdev; |
| bio->bi_end_io = write_super_endio; |
| bio->bi_private = ca; |
| |
| closure_get(cl); |
| __write_super(&ca->sb, bio); |
| } |
| |
| closure_return_with_destructor(cl, bcache_write_super_unlock); |
| } |
| |
| /* UUID io */ |
| |
| static void uuid_endio(struct bio *bio) |
| { |
| struct closure *cl = bio->bi_private; |
| struct cache_set *c = container_of(cl, struct cache_set, uuid_write); |
| |
| cache_set_err_on(bio->bi_error, c, "accessing uuids"); |
| bch_bbio_free(bio, c); |
| closure_put(cl); |
| } |
| |
| static void uuid_io_unlock(struct closure *cl) |
| { |
| struct cache_set *c = container_of(cl, struct cache_set, uuid_write); |
| |
| up(&c->uuid_write_mutex); |
| } |
| |
| static void uuid_io(struct cache_set *c, int op, unsigned long op_flags, |
| struct bkey *k, struct closure *parent) |
| { |
| struct closure *cl = &c->uuid_write; |
| struct uuid_entry *u; |
| unsigned i; |
| char buf[80]; |
| |
| BUG_ON(!parent); |
| down(&c->uuid_write_mutex); |
| closure_init(cl, parent); |
| |
| for (i = 0; i < KEY_PTRS(k); i++) { |
| struct bio *bio = bch_bbio_alloc(c); |
| |
| bio->bi_opf = REQ_SYNC | REQ_META | op_flags; |
| bio->bi_iter.bi_size = KEY_SIZE(k) << 9; |
| |
| bio->bi_end_io = uuid_endio; |
| bio->bi_private = cl; |
| bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags); |
| bch_bio_map(bio, c->uuids); |
| |
| bch_submit_bbio(bio, c, k, i); |
| |
| if (op != REQ_OP_WRITE) |
| break; |
| } |
| |
| bch_extent_to_text(buf, sizeof(buf), k); |
| pr_debug("%s UUIDs at %s", op == REQ_OP_WRITE ? "wrote" : "read", buf); |
| |
| for (u = c->uuids; u < c->uuids + c->nr_uuids; u++) |
| if (!bch_is_zero(u->uuid, 16)) |
| pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u", |
| u - c->uuids, u->uuid, u->label, |
| u->first_reg, u->last_reg, u->invalidated); |
| |
| closure_return_with_destructor(cl, uuid_io_unlock); |
| } |
| |
| static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl) |
| { |
| struct bkey *k = &j->uuid_bucket; |
| |
| if (__bch_btree_ptr_invalid(c, k)) |
| return "bad uuid pointer"; |
| |
| bkey_copy(&c->uuid_bucket, k); |
| uuid_io(c, REQ_OP_READ, 0, k, cl); |
| |
| if (j->version < BCACHE_JSET_VERSION_UUIDv1) { |
| struct uuid_entry_v0 *u0 = (void *) c->uuids; |
| struct uuid_entry *u1 = (void *) c->uuids; |
| int i; |
| |
| closure_sync(cl); |
| |
| /* |
| * Since the new uuid entry is bigger than the old, we have to |
| * convert starting at the highest memory address and work down |
| * in order to do it in place |
| */ |
| |
| for (i = c->nr_uuids - 1; |
| i >= 0; |
| --i) { |
| memcpy(u1[i].uuid, u0[i].uuid, 16); |
| memcpy(u1[i].label, u0[i].label, 32); |
| |
| u1[i].first_reg = u0[i].first_reg; |
| u1[i].last_reg = u0[i].last_reg; |
| u1[i].invalidated = u0[i].invalidated; |
| |
| u1[i].flags = 0; |
| u1[i].sectors = 0; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| static int __uuid_write(struct cache_set *c) |
| { |
| BKEY_PADDED(key) k; |
| struct closure cl; |
| closure_init_stack(&cl); |
| |
| lockdep_assert_held(&bch_register_lock); |
| |
| if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true)) |
| return 1; |
| |
| SET_KEY_SIZE(&k.key, c->sb.bucket_size); |
| uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl); |
| closure_sync(&cl); |
| |
| bkey_copy(&c->uuid_bucket, &k.key); |
| bkey_put(c, &k.key); |
| return 0; |
| } |
| |
| int bch_uuid_write(struct cache_set *c) |
| { |
| int ret = __uuid_write(c); |
| |
| if (!ret) |
| bch_journal_meta(c, NULL); |
| |
| return ret; |
| } |
| |
| static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid) |
| { |
| struct uuid_entry *u; |
| |
| for (u = c->uuids; |
| u < c->uuids + c->nr_uuids; u++) |
| if (!memcmp(u->uuid, uuid, 16)) |
| return u; |
| |
| return NULL; |
| } |
| |
| static struct uuid_entry *uuid_find_empty(struct cache_set *c) |
| { |
| static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; |
| return uuid_find(c, zero_uuid); |
| } |
| |
| /* |
| * Bucket priorities/gens: |
| * |
| * For each bucket, we store on disk its |
| * 8 bit gen |
| * 16 bit priority |
| * |
| * See alloc.c for an explanation of the gen. The priority is used to implement |
| * lru (and in the future other) cache replacement policies; for most purposes |
| * it's just an opaque integer. |
| * |
| * The gens and the priorities don't have a whole lot to do with each other, and |
| * it's actually the gens that must be written out at specific times - it's no |
| * big deal if the priorities don't get written, if we lose them we just reuse |
| * buckets in suboptimal order. |
| * |
| * On disk they're stored in a packed array, and in as many buckets are required |
| * to fit them all. The buckets we use to store them form a list; the journal |
| * header points to the first bucket, the first bucket points to the second |
| * bucket, et cetera. |
| * |
| * This code is used by the allocation code; periodically (whenever it runs out |
| * of buckets to allocate from) the allocation code will invalidate some |
| * buckets, but it can't use those buckets until their new gens are safely on |
| * disk. |
| */ |
| |
| static void prio_endio(struct bio *bio) |
| { |
| struct cache *ca = bio->bi_private; |
| |
| cache_set_err_on(bio->bi_error, ca->set, "accessing priorities"); |
| bch_bbio_free(bio, ca->set); |
| closure_put(&ca->prio); |
| } |
| |
| static void prio_io(struct cache *ca, uint64_t bucket, int op, |
| unsigned long op_flags) |
| { |
| struct closure *cl = &ca->prio; |
| struct bio *bio = bch_bbio_alloc(ca->set); |
| |
| closure_init_stack(cl); |
| |
| bio->bi_iter.bi_sector = bucket * ca->sb.bucket_size; |
| bio->bi_bdev = ca->bdev; |
| bio->bi_iter.bi_size = bucket_bytes(ca); |
| |
| bio->bi_end_io = prio_endio; |
| bio->bi_private = ca; |
| bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags); |
| bch_bio_map(bio, ca->disk_buckets); |
| |
| closure_bio_submit(bio, &ca->prio); |
| closure_sync(cl); |
| } |
| |
| void bch_prio_write(struct cache *ca) |
| { |
| int i; |
| struct bucket *b; |
| struct closure cl; |
| |
| closure_init_stack(&cl); |
| |
| lockdep_assert_held(&ca->set->bucket_lock); |
| |
| ca->disk_buckets->seq++; |
| |
| atomic_long_add(ca->sb.bucket_size * prio_buckets(ca), |
| &ca->meta_sectors_written); |
| |
| //pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free), |
| // fifo_used(&ca->free_inc), fifo_used(&ca->unused)); |
| |
| for (i = prio_buckets(ca) - 1; i >= 0; --i) { |
| long bucket; |
| struct prio_set *p = ca->disk_buckets; |
| struct bucket_disk *d = p->data; |
| struct bucket_disk *end = d + prios_per_bucket(ca); |
| |
| for (b = ca->buckets + i * prios_per_bucket(ca); |
| b < ca->buckets + ca->sb.nbuckets && d < end; |
| b++, d++) { |
| d->prio = cpu_to_le16(b->prio); |
| d->gen = b->gen; |
| } |
| |
| p->next_bucket = ca->prio_buckets[i + 1]; |
| p->magic = pset_magic(&ca->sb); |
| p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8); |
| |
| bucket = bch_bucket_alloc(ca, RESERVE_PRIO, true); |
| BUG_ON(bucket == -1); |
| |
| mutex_unlock(&ca->set->bucket_lock); |
| prio_io(ca, bucket, REQ_OP_WRITE, 0); |
| mutex_lock(&ca->set->bucket_lock); |
| |
| ca->prio_buckets[i] = bucket; |
| atomic_dec_bug(&ca->buckets[bucket].pin); |
| } |
| |
| mutex_unlock(&ca->set->bucket_lock); |
| |
| bch_journal_meta(ca->set, &cl); |
| closure_sync(&cl); |
| |
| mutex_lock(&ca->set->bucket_lock); |
| |
| /* |
| * Don't want the old priorities to get garbage collected until after we |
| * finish writing the new ones, and they're journalled |
| */ |
| for (i = 0; i < prio_buckets(ca); i++) { |
| if (ca->prio_last_buckets[i]) |
| __bch_bucket_free(ca, |
| &ca->buckets[ca->prio_last_buckets[i]]); |
| |
| ca->prio_last_buckets[i] = ca->prio_buckets[i]; |
| } |
| } |
| |
| static void prio_read(struct cache *ca, uint64_t bucket) |
| { |
| struct prio_set *p = ca->disk_buckets; |
| struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d; |
| struct bucket *b; |
| unsigned bucket_nr = 0; |
| |
| for (b = ca->buckets; |
| b < ca->buckets + ca->sb.nbuckets; |
| b++, d++) { |
| if (d == end) { |
| ca->prio_buckets[bucket_nr] = bucket; |
| ca->prio_last_buckets[bucket_nr] = bucket; |
| bucket_nr++; |
| |
| prio_io(ca, bucket, REQ_OP_READ, 0); |
| |
| if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8)) |
| pr_warn("bad csum reading priorities"); |
| |
| if (p->magic != pset_magic(&ca->sb)) |
| pr_warn("bad magic reading priorities"); |
| |
| bucket = p->next_bucket; |
| d = p->data; |
| } |
| |
| b->prio = le16_to_cpu(d->prio); |
| b->gen = b->last_gc = d->gen; |
| } |
| } |
| |
| /* Bcache device */ |
| |
| static int open_dev(struct block_device *b, fmode_t mode) |
| { |
| struct bcache_device *d = b->bd_disk->private_data; |
| if (test_bit(BCACHE_DEV_CLOSING, &d->flags)) |
| return -ENXIO; |
| |
| closure_get(&d->cl); |
| return 0; |
| } |
| |
| static void release_dev(struct gendisk *b, fmode_t mode) |
| { |
| struct bcache_device *d = b->private_data; |
| closure_put(&d->cl); |
| } |
| |
| static int ioctl_dev(struct block_device *b, fmode_t mode, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct bcache_device *d = b->bd_disk->private_data; |
| return d->ioctl(d, mode, cmd, arg); |
| } |
| |
| static const struct block_device_operations bcache_ops = { |
| .open = open_dev, |
| .release = release_dev, |
| .ioctl = ioctl_dev, |
| .owner = THIS_MODULE, |
| }; |
| |
| void bcache_device_stop(struct bcache_device *d) |
| { |
| if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags)) |
| closure_queue(&d->cl); |
| } |
| |
| static void bcache_device_unlink(struct bcache_device *d) |
| { |
| lockdep_assert_held(&bch_register_lock); |
| |
| if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) { |
| unsigned i; |
| struct cache *ca; |
| |
| sysfs_remove_link(&d->c->kobj, d->name); |
| sysfs_remove_link(&d->kobj, "cache"); |
| |
| for_each_cache(ca, d->c, i) |
| bd_unlink_disk_holder(ca->bdev, d->disk); |
| } |
| } |
| |
| static void bcache_device_link(struct bcache_device *d, struct cache_set *c, |
| const char *name) |
| { |
| unsigned i; |
| struct cache *ca; |
| |
| for_each_cache(ca, d->c, i) |
| bd_link_disk_holder(ca->bdev, d->disk); |
| |
| snprintf(d->name, BCACHEDEVNAME_SIZE, |
| "%s%u", name, d->id); |
| |
| WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") || |
| sysfs_create_link(&c->kobj, &d->kobj, d->name), |
| "Couldn't create device <-> cache set symlinks"); |
| |
| clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags); |
| } |
| |
| static void bcache_device_detach(struct bcache_device *d) |
| { |
| lockdep_assert_held(&bch_register_lock); |
| |
| if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) { |
| struct uuid_entry *u = d->c->uuids + d->id; |
| |
| SET_UUID_FLASH_ONLY(u, 0); |
| memcpy(u->uuid, invalid_uuid, 16); |
| u->invalidated = cpu_to_le32(get_seconds()); |
| bch_uuid_write(d->c); |
| } |
| |
| bcache_device_unlink(d); |
| |
| d->c->devices[d->id] = NULL; |
| closure_put(&d->c->caching); |
| d->c = NULL; |
| } |
| |
| static void bcache_device_attach(struct bcache_device *d, struct cache_set *c, |
| unsigned id) |
| { |
| d->id = id; |
| d->c = c; |
| c->devices[id] = d; |
| |
| closure_get(&c->caching); |
| } |
| |
| static void bcache_device_free(struct bcache_device *d) |
| { |
| lockdep_assert_held(&bch_register_lock); |
| |
| pr_info("%s stopped", d->disk->disk_name); |
| |
| if (d->c) |
| bcache_device_detach(d); |
| if (d->disk && d->disk->flags & GENHD_FL_UP) |
| del_gendisk(d->disk); |
| if (d->disk && d->disk->queue) |
| blk_cleanup_queue(d->disk->queue); |
| if (d->disk) { |
| ida_simple_remove(&bcache_minor, d->disk->first_minor); |
| put_disk(d->disk); |
| } |
| |
| if (d->bio_split) |
| bioset_free(d->bio_split); |
| kvfree(d->full_dirty_stripes); |
| kvfree(d->stripe_sectors_dirty); |
| |
| closure_debug_destroy(&d->cl); |
| } |
| |
| static int bcache_device_init(struct bcache_device *d, unsigned block_size, |
| sector_t sectors) |
| { |
| struct request_queue *q; |
| size_t n; |
| int minor; |
| |
| if (!d->stripe_size) |
| d->stripe_size = 1 << 31; |
| |
| d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size); |
| |
| if (!d->nr_stripes || |
| d->nr_stripes > INT_MAX || |
| d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) { |
| pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)", |
| (unsigned)d->nr_stripes); |
| return -ENOMEM; |
| } |
| |
| n = d->nr_stripes * sizeof(atomic_t); |
| d->stripe_sectors_dirty = n < PAGE_SIZE << 6 |
| ? kzalloc(n, GFP_KERNEL) |
| : vzalloc(n); |
| if (!d->stripe_sectors_dirty) |
| return -ENOMEM; |
| |
| n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long); |
| d->full_dirty_stripes = n < PAGE_SIZE << 6 |
| ? kzalloc(n, GFP_KERNEL) |
| : vzalloc(n); |
| if (!d->full_dirty_stripes) |
| return -ENOMEM; |
| |
| minor = ida_simple_get(&bcache_minor, 0, MINORMASK + 1, GFP_KERNEL); |
| if (minor < 0) |
| return minor; |
| |
| minor *= BCACHE_MINORS; |
| |
| if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) || |
| !(d->disk = alloc_disk(BCACHE_MINORS))) { |
| ida_simple_remove(&bcache_minor, minor); |
| return -ENOMEM; |
| } |
| |
| set_capacity(d->disk, sectors); |
| snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", minor); |
| |
| d->disk->major = bcache_major; |
| d->disk->first_minor = minor; |
| d->disk->fops = &bcache_ops; |
| d->disk->private_data = d; |
| |
| q = blk_alloc_queue(GFP_KERNEL); |
| if (!q) |
| return -ENOMEM; |
| |
| blk_queue_make_request(q, NULL); |
| d->disk->queue = q; |
| q->queuedata = d; |
| q->backing_dev_info->congested_data = d; |
| q->limits.max_hw_sectors = UINT_MAX; |
| q->limits.max_sectors = UINT_MAX; |
| q->limits.max_segment_size = UINT_MAX; |
| q->limits.max_segments = BIO_MAX_PAGES; |
| blk_queue_max_discard_sectors(q, UINT_MAX); |
| q->limits.discard_granularity = 512; |
| q->limits.io_min = block_size; |
| q->limits.logical_block_size = block_size; |
| q->limits.physical_block_size = block_size; |
| set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags); |
| clear_bit(QUEUE_FLAG_ADD_RANDOM, &d->disk->queue->queue_flags); |
| set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags); |
| |
| blk_queue_write_cache(q, true, true); |
| |
| return 0; |
| } |
| |
| /* Cached device */ |
| |
| static void calc_cached_dev_sectors(struct cache_set *c) |
| { |
| uint64_t sectors = 0; |
| struct cached_dev *dc; |
| |
| list_for_each_entry(dc, &c->cached_devs, list) |
| sectors += bdev_sectors(dc->bdev); |
| |
| c->cached_dev_sectors = sectors; |
| } |
| |
| void bch_cached_dev_run(struct cached_dev *dc) |
| { |
| struct bcache_device *d = &dc->disk; |
| char buf[SB_LABEL_SIZE + 1]; |
| char *env[] = { |
| "DRIVER=bcache", |
| kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid), |
| NULL, |
| NULL, |
| }; |
| |
| memcpy(buf, dc->sb.label, SB_LABEL_SIZE); |
| buf[SB_LABEL_SIZE] = '\0'; |
| env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf); |
| |
| if (atomic_xchg(&dc->running, 1)) { |
| kfree(env[1]); |
| kfree(env[2]); |
| return; |
| } |
| |
| if (!d->c && |
| BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) { |
| struct closure cl; |
| closure_init_stack(&cl); |
| |
| SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE); |
| bch_write_bdev_super(dc, &cl); |
| closure_sync(&cl); |
| } |
| |
| add_disk(d->disk); |
| bd_link_disk_holder(dc->bdev, dc->disk.disk); |
| /* won't show up in the uevent file, use udevadm monitor -e instead |
| * only class / kset properties are persistent */ |
| kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env); |
| kfree(env[1]); |
| kfree(env[2]); |
| |
| if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") || |
| sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache")) |
| pr_debug("error creating sysfs link"); |
| } |
| |
| static void cached_dev_detach_finish(struct work_struct *w) |
| { |
| struct cached_dev *dc = container_of(w, struct cached_dev, detach); |
| char buf[BDEVNAME_SIZE]; |
| struct closure cl; |
| closure_init_stack(&cl); |
| |
| BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)); |
| BUG_ON(atomic_read(&dc->count)); |
| |
| mutex_lock(&bch_register_lock); |
| |
| memset(&dc->sb.set_uuid, 0, 16); |
| SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE); |
| |
| bch_write_bdev_super(dc, &cl); |
| closure_sync(&cl); |
| |
| bcache_device_detach(&dc->disk); |
| list_move(&dc->list, &uncached_devices); |
| |
| clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags); |
| clear_bit(BCACHE_DEV_UNLINK_DONE, &dc->disk.flags); |
| |
| mutex_unlock(&bch_register_lock); |
| |
| pr_info("Caching disabled for %s", bdevname(dc->bdev, buf)); |
| |
| /* Drop ref we took in cached_dev_detach() */ |
| closure_put(&dc->disk.cl); |
| } |
| |
| void bch_cached_dev_detach(struct cached_dev *dc) |
| { |
| lockdep_assert_held(&bch_register_lock); |
| |
| if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags)) |
| return; |
| |
| if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) |
| return; |
| |
| /* |
| * Block the device from being closed and freed until we're finished |
| * detaching |
| */ |
| closure_get(&dc->disk.cl); |
| |
| bch_writeback_queue(dc); |
| cached_dev_put(dc); |
| } |
| |
| int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c) |
| { |
| uint32_t rtime = cpu_to_le32(get_seconds()); |
| struct uuid_entry *u; |
| char buf[BDEVNAME_SIZE]; |
| |
| bdevname(dc->bdev, buf); |
| |
| if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16)) |
| return -ENOENT; |
| |
| if (dc->disk.c) { |
| pr_err("Can't attach %s: already attached", buf); |
| return -EINVAL; |
| } |
| |
| if (test_bit(CACHE_SET_STOPPING, &c->flags)) { |
| pr_err("Can't attach %s: shutting down", buf); |
| return -EINVAL; |
| } |
| |
| if (dc->sb.block_size < c->sb.block_size) { |
| /* Will die */ |
| pr_err("Couldn't attach %s: block size less than set's block size", |
| buf); |
| return -EINVAL; |
| } |
| |
| u = uuid_find(c, dc->sb.uuid); |
| |
| if (u && |
| (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE || |
| BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) { |
| memcpy(u->uuid, invalid_uuid, 16); |
| u->invalidated = cpu_to_le32(get_seconds()); |
| u = NULL; |
| } |
| |
| if (!u) { |
| if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) { |
| pr_err("Couldn't find uuid for %s in set", buf); |
| return -ENOENT; |
| } |
| |
| u = uuid_find_empty(c); |
| if (!u) { |
| pr_err("Not caching %s, no room for UUID", buf); |
| return -EINVAL; |
| } |
| } |
| |
| /* Deadlocks since we're called via sysfs... |
| sysfs_remove_file(&dc->kobj, &sysfs_attach); |
| */ |
| |
| if (bch_is_zero(u->uuid, 16)) { |
| struct closure cl; |
| closure_init_stack(&cl); |
| |
| memcpy(u->uuid, dc->sb.uuid, 16); |
| memcpy(u->label, dc->sb.label, SB_LABEL_SIZE); |
| u->first_reg = u->last_reg = rtime; |
| bch_uuid_write(c); |
| |
| memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16); |
| SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN); |
| |
| bch_write_bdev_super(dc, &cl); |
| closure_sync(&cl); |
| } else { |
| u->last_reg = rtime; |
| bch_uuid_write(c); |
| } |
| |
| bcache_device_attach(&dc->disk, c, u - c->uuids); |
| list_move(&dc->list, &c->cached_devs); |
| calc_cached_dev_sectors(c); |
| |
| smp_wmb(); |
| /* |
| * dc->c must be set before dc->count != 0 - paired with the mb in |
| * cached_dev_get() |
| */ |
| atomic_set(&dc->count, 1); |
| |
| /* Block writeback thread, but spawn it */ |
| down_write(&dc->writeback_lock); |
| if (bch_cached_dev_writeback_start(dc)) { |
| up_write(&dc->writeback_lock); |
| return -ENOMEM; |
| } |
| |
| if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) { |
| bch_sectors_dirty_init(dc); |
| atomic_set(&dc->has_dirty, 1); |
| atomic_inc(&dc->count); |
| bch_writeback_queue(dc); |
| } |
| |
| bch_cached_dev_run(dc); |
| bcache_device_link(&dc->disk, c, "bdev"); |
| |
| /* Allow the writeback thread to proceed */ |
| up_write(&dc->writeback_lock); |
| |
| pr_info("Caching %s as %s on set %pU", |
| bdevname(dc->bdev, buf), dc->disk.disk->disk_name, |
| dc->disk.c->sb.set_uuid); |
| return 0; |
| } |
| |
| void bch_cached_dev_release(struct kobject *kobj) |
| { |
| struct cached_dev *dc = container_of(kobj, struct cached_dev, |
| disk.kobj); |
| kfree(dc); |
| module_put(THIS_MODULE); |
| } |
| |
| static void cached_dev_free(struct closure *cl) |
| { |
| struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl); |
| |
| cancel_delayed_work_sync(&dc->writeback_rate_update); |
| if (!IS_ERR_OR_NULL(dc->writeback_thread)) |
| kthread_stop(dc->writeback_thread); |
| |
| mutex_lock(&bch_register_lock); |
| |
| if (atomic_read(&dc->running)) |
| bd_unlink_disk_holder(dc->bdev, dc->disk.disk); |
| bcache_device_free(&dc->disk); |
| list_del(&dc->list); |
| |
| mutex_unlock(&bch_register_lock); |
| |
| if (!IS_ERR_OR_NULL(dc->bdev)) |
| blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
| |
| wake_up(&unregister_wait); |
| |
| kobject_put(&dc->disk.kobj); |
| } |
| |
| static void cached_dev_flush(struct closure *cl) |
| { |
| struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl); |
| struct bcache_device *d = &dc->disk; |
| |
| mutex_lock(&bch_register_lock); |
| bcache_device_unlink(d); |
| mutex_unlock(&bch_register_lock); |
| |
| bch_cache_accounting_destroy(&dc->accounting); |
| kobject_del(&d->kobj); |
| |
| continue_at(cl, cached_dev_free, system_wq); |
| } |
| |
| static int cached_dev_init(struct cached_dev *dc, unsigned block_size) |
| { |
| int ret; |
| struct io *io; |
| struct request_queue *q = bdev_get_queue(dc->bdev); |
| |
| __module_get(THIS_MODULE); |
| INIT_LIST_HEAD(&dc->list); |
| closure_init(&dc->disk.cl, NULL); |
| set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq); |
| kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype); |
| INIT_WORK(&dc->detach, cached_dev_detach_finish); |
| sema_init(&dc->sb_write_mutex, 1); |
| INIT_LIST_HEAD(&dc->io_lru); |
| spin_lock_init(&dc->io_lock); |
| bch_cache_accounting_init(&dc->accounting, &dc->disk.cl); |
| |
| dc->sequential_cutoff = 4 << 20; |
| |
| for (io = dc->io; io < dc->io + RECENT_IO; io++) { |
| list_add(&io->lru, &dc->io_lru); |
| hlist_add_head(&io->hash, dc->io_hash + RECENT_IO); |
| } |
| |
| dc->disk.stripe_size = q->limits.io_opt >> 9; |
| |
| if (dc->disk.stripe_size) |
| dc->partial_stripes_expensive = |
| q->limits.raid_partial_stripes_expensive; |
| |
| ret = bcache_device_init(&dc->disk, block_size, |
| dc->bdev->bd_part->nr_sects - dc->sb.data_offset); |
| if (ret) |
| return ret; |
| |
| set_capacity(dc->disk.disk, |
| dc->bdev->bd_part->nr_sects - dc->sb.data_offset); |
| |
| dc->disk.disk->queue->backing_dev_info->ra_pages = |
| max(dc->disk.disk->queue->backing_dev_info->ra_pages, |
| q->backing_dev_info->ra_pages); |
| |
| bch_cached_dev_request_init(dc); |
| bch_cached_dev_writeback_init(dc); |
| return 0; |
| } |
| |
| /* Cached device - bcache superblock */ |
| |
| static void register_bdev(struct cache_sb *sb, struct page *sb_page, |
| struct block_device *bdev, |
| struct cached_dev *dc) |
| { |
| char name[BDEVNAME_SIZE]; |
| const char *err = "cannot allocate memory"; |
| struct cache_set *c; |
| |
| memcpy(&dc->sb, sb, sizeof(struct cache_sb)); |
| dc->bdev = bdev; |
| dc->bdev->bd_holder = dc; |
| |
| bio_init(&dc->sb_bio, dc->sb_bio.bi_inline_vecs, 1); |
| dc->sb_bio.bi_io_vec[0].bv_page = sb_page; |
| get_page(sb_page); |
| |
| if (cached_dev_init(dc, sb->block_size << 9)) |
| goto err; |
| |
| err = "error creating kobject"; |
| if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj, |
| "bcache")) |
| goto err; |
| if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj)) |
| goto err; |
| |
| pr_info("registered backing device %s", bdevname(bdev, name)); |
| |
| list_add(&dc->list, &uncached_devices); |
| list_for_each_entry(c, &bch_cache_sets, list) |
| bch_cached_dev_attach(dc, c); |
| |
| if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE || |
| BDEV_STATE(&dc->sb) == BDEV_STATE_STALE) |
| bch_cached_dev_run(dc); |
| |
| return; |
| err: |
| pr_notice("error opening %s: %s", bdevname(bdev, name), err); |
| bcache_device_stop(&dc->disk); |
| } |
| |
| /* Flash only volumes */ |
| |
| void bch_flash_dev_release(struct kobject *kobj) |
| { |
| struct bcache_device *d = container_of(kobj, struct bcache_device, |
| kobj); |
| kfree(d); |
| } |
| |
| static void flash_dev_free(struct closure *cl) |
| { |
| struct bcache_device *d = container_of(cl, struct bcache_device, cl); |
| mutex_lock(&bch_register_lock); |
| bcache_device_free(d); |
| mutex_unlock(&bch_register_lock); |
| kobject_put(&d->kobj); |
| } |
| |
| static void flash_dev_flush(struct closure *cl) |
| { |
| struct bcache_device *d = container_of(cl, struct bcache_device, cl); |
| |
| mutex_lock(&bch_register_lock); |
| bcache_device_unlink(d); |
| mutex_unlock(&bch_register_lock); |
| kobject_del(&d->kobj); |
| continue_at(cl, flash_dev_free, system_wq); |
| } |
| |
| static int flash_dev_run(struct cache_set *c, struct uuid_entry *u) |
| { |
| struct bcache_device *d = kzalloc(sizeof(struct bcache_device), |
| GFP_KERNEL); |
| if (!d) |
| return -ENOMEM; |
| |
| closure_init(&d->cl, NULL); |
| set_closure_fn(&d->cl, flash_dev_flush, system_wq); |
| |
| kobject_init(&d->kobj, &bch_flash_dev_ktype); |
| |
| if (bcache_device_init(d, block_bytes(c), u->sectors)) |
| goto err; |
| |
| bcache_device_attach(d, c, u - c->uuids); |
| bch_flash_dev_request_init(d); |
| add_disk(d->disk); |
| |
| if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache")) |
| goto err; |
| |
| bcache_device_link(d, c, "volume"); |
| |
| return 0; |
| err: |
| kobject_put(&d->kobj); |
| return -ENOMEM; |
| } |
| |
| static int flash_devs_run(struct cache_set *c) |
| { |
| int ret = 0; |
| struct uuid_entry *u; |
| |
| for (u = c->uuids; |
| u < c->uuids + c->nr_uuids && !ret; |
| u++) |
| if (UUID_FLASH_ONLY(u)) |
| ret = flash_dev_run(c, u); |
| |
| return ret; |
| } |
| |
| int bch_flash_dev_create(struct cache_set *c, uint64_t size) |
| { |
| struct uuid_entry *u; |
| |
| if (test_bit(CACHE_SET_STOPPING, &c->flags)) |
| return -EINTR; |
| |
| if (!test_bit(CACHE_SET_RUNNING, &c->flags)) |
| return -EPERM; |
| |
| u = uuid_find_empty(c); |
| if (!u) { |
| pr_err("Can't create volume, no room for UUID"); |
| return -EINVAL; |
| } |
| |
| get_random_bytes(u->uuid, 16); |
| memset(u->label, 0, 32); |
| u->first_reg = u->last_reg = cpu_to_le32(get_seconds()); |
| |
| SET_UUID_FLASH_ONLY(u, 1); |
| u->sectors = size >> 9; |
| |
| bch_uuid_write(c); |
| |
| return flash_dev_run(c, u); |
| } |
| |
| /* Cache set */ |
| |
| __printf(2, 3) |
| bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...) |
| { |
| va_list args; |
| |
| if (c->on_error != ON_ERROR_PANIC && |
| test_bit(CACHE_SET_STOPPING, &c->flags)) |
| return false; |
| |
| /* XXX: we can be called from atomic context |
| acquire_console_sem(); |
| */ |
| |
| printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid); |
| |
| va_start(args, fmt); |
| vprintk(fmt, args); |
| va_end(args); |
| |
| printk(", disabling caching\n"); |
| |
| if (c->on_error == ON_ERROR_PANIC) |
| panic("panic forced after error\n"); |
| |
| bch_cache_set_unregister(c); |
| return true; |
| } |
| |
| void bch_cache_set_release(struct kobject *kobj) |
| { |
| struct cache_set *c = container_of(kobj, struct cache_set, kobj); |
| kfree(c); |
| module_put(THIS_MODULE); |
| } |
| |
| static void cache_set_free(struct closure *cl) |
| { |
| struct cache_set *c = container_of(cl, struct cache_set, cl); |
| struct cache *ca; |
| unsigned i; |
| |
| if (!IS_ERR_OR_NULL(c->debug)) |
| debugfs_remove(c->debug); |
| |
| bch_open_buckets_free(c); |
| bch_btree_cache_free(c); |
| bch_journal_free(c); |
| |
| for_each_cache(ca, c, i) |
| if (ca) { |
| ca->set = NULL; |
| c->cache[ca->sb.nr_this_dev] = NULL; |
| kobject_put(&ca->kobj); |
| } |
| |
| bch_bset_sort_state_free(&c->sort); |
| free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c))); |
| |
| if (c->moving_gc_wq) |
| destroy_workqueue(c->moving_gc_wq); |
| if (c->bio_split) |
| bioset_free(c->bio_split); |
| if (c->fill_iter) |
| mempool_destroy(c->fill_iter); |
| if (c->bio_meta) |
| mempool_destroy(c->bio_meta); |
| if (c->search) |
| mempool_destroy(c->search); |
| kfree(c->devices); |
| |
| mutex_lock(&bch_register_lock); |
| list_del(&c->list); |
| mutex_unlock(&bch_register_lock); |
| |
| pr_info("Cache set %pU unregistered", c->sb.set_uuid); |
| wake_up(&unregister_wait); |
| |
| closure_debug_destroy(&c->cl); |
| kobject_put(&c->kobj); |
| } |
| |
| static void cache_set_flush(struct closure *cl) |
| { |
| struct cache_set *c = container_of(cl, struct cache_set, caching); |
| struct cache *ca; |
| struct btree *b; |
| unsigned i; |
| |
| if (!c) |
| closure_return(cl); |
| |
| bch_cache_accounting_destroy(&c->accounting); |
| |
| kobject_put(&c->internal); |
| kobject_del(&c->kobj); |
| |
| if (c->gc_thread) |
| kthread_stop(c->gc_thread); |
| |
| if (!IS_ERR_OR_NULL(c->root)) |
| list_add(&c->root->list, &c->btree_cache); |
| |
| /* Should skip this if we're unregistering because of an error */ |
| list_for_each_entry(b, &c->btree_cache, list) { |
| mutex_lock(&b->write_lock); |
| if (btree_node_dirty(b)) |
| __bch_btree_node_write(b, NULL); |
| mutex_unlock(&b->write_lock); |
| } |
| |
| for_each_cache(ca, c, i) |
| if (ca->alloc_thread) |
| kthread_stop(ca->alloc_thread); |
| |
| if (c->journal.cur) { |
| cancel_delayed_work_sync(&c->journal.work); |
| /* flush last journal entry if needed */ |
| c->journal.work.work.func(&c->journal.work.work); |
| } |
| |
| closure_return(cl); |
| } |
| |
| static void __cache_set_unregister(struct closure *cl) |
| { |
| struct cache_set *c = container_of(cl, struct cache_set, caching); |
| struct cached_dev *dc; |
| size_t i; |
| |
| mutex_lock(&bch_register_lock); |
| |
| for (i = 0; i < c->nr_uuids; i++) |
| if (c->devices[i]) { |
| if (!UUID_FLASH_ONLY(&c->uuids[i]) && |
| test_bit(CACHE_SET_UNREGISTERING, &c->flags)) { |
| dc = container_of(c->devices[i], |
| struct cached_dev, disk); |
| bch_cached_dev_detach(dc); |
| } else { |
| bcache_device_stop(c->devices[i]); |
| } |
| } |
| |
| mutex_unlock(&bch_register_lock); |
| |
| continue_at(cl, cache_set_flush, system_wq); |
| } |
| |
| void bch_cache_set_stop(struct cache_set *c) |
| { |
| if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags)) |
| closure_queue(&c->caching); |
| } |
| |
| void bch_cache_set_unregister(struct cache_set *c) |
| { |
| set_bit(CACHE_SET_UNREGISTERING, &c->flags); |
| bch_cache_set_stop(c); |
| } |
| |
| #define alloc_bucket_pages(gfp, c) \ |
| ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c)))) |
| |
| struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) |
| { |
| int iter_size; |
| struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL); |
| if (!c) |
| return NULL; |
| |
| __module_get(THIS_MODULE); |
| closure_init(&c->cl, NULL); |
| set_closure_fn(&c->cl, cache_set_free, system_wq); |
| |
| closure_init(&c->caching, &c->cl); |
| set_closure_fn(&c->caching, __cache_set_unregister, system_wq); |
| |
| /* Maybe create continue_at_noreturn() and use it here? */ |
| closure_set_stopped(&c->cl); |
| closure_put(&c->cl); |
| |
| kobject_init(&c->kobj, &bch_cache_set_ktype); |
| kobject_init(&c->internal, &bch_cache_set_internal_ktype); |
| |
| bch_cache_accounting_init(&c->accounting, &c->cl); |
| |
| memcpy(c->sb.set_uuid, sb->set_uuid, 16); |
| c->sb.block_size = sb->block_size; |
| c->sb.bucket_size = sb->bucket_size; |
| c->sb.nr_in_set = sb->nr_in_set; |
| c->sb.last_mount = sb->last_mount; |
| c->bucket_bits = ilog2(sb->bucket_size); |
| c->block_bits = ilog2(sb->block_size); |
| c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry); |
| |
| c->btree_pages = bucket_pages(c); |
| if (c->btree_pages > BTREE_MAX_PAGES) |
| c->btree_pages = max_t(int, c->btree_pages / 4, |
| BTREE_MAX_PAGES); |
| |
| sema_init(&c->sb_write_mutex, 1); |
| mutex_init(&c->bucket_lock); |
| init_waitqueue_head(&c->btree_cache_wait); |
| init_waitqueue_head(&c->bucket_wait); |
| init_waitqueue_head(&c->gc_wait); |
| sema_init(&c->uuid_write_mutex, 1); |
| |
| spin_lock_init(&c->btree_gc_time.lock); |
| spin_lock_init(&c->btree_split_time.lock); |
| spin_lock_init(&c->btree_read_time.lock); |
| |
| bch_moving_init_cache_set(c); |
| |
| INIT_LIST_HEAD(&c->list); |
| INIT_LIST_HEAD(&c->cached_devs); |
| INIT_LIST_HEAD(&c->btree_cache); |
| INIT_LIST_HEAD(&c->btree_cache_freeable); |
| INIT_LIST_HEAD(&c->btree_cache_freed); |
| INIT_LIST_HEAD(&c->data_buckets); |
| |
| c->search = mempool_create_slab_pool(32, bch_search_cache); |
| if (!c->search) |
| goto err; |
| |
| iter_size = (sb->bucket_size / sb->block_size + 1) * |
| sizeof(struct btree_iter_set); |
| |
| if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) || |
| !(c->bio_meta = mempool_create_kmalloc_pool(2, |
| sizeof(struct bbio) + sizeof(struct bio_vec) * |
| bucket_pages(c))) || |
| !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) || |
| !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) || |
| !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) || |
| !(c->moving_gc_wq = alloc_workqueue("bcache_gc", |
| WQ_MEM_RECLAIM, 0)) || |
| bch_journal_alloc(c) || |
| bch_btree_cache_alloc(c) || |
| bch_open_buckets_alloc(c) || |
| bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages))) |
| goto err; |
| |
| c->congested_read_threshold_us = 2000; |
| c->congested_write_threshold_us = 20000; |
| c->error_limit = 8 << IO_ERROR_SHIFT; |
| |
| return c; |
| err: |
| bch_cache_set_unregister(c); |
| return NULL; |
| } |
| |
| static void run_cache_set(struct cache_set *c) |
| { |
| const char *err = "cannot allocate memory"; |
| struct cached_dev *dc, *t; |
| struct cache *ca; |
| struct closure cl; |
| unsigned i; |
| |
| closure_init_stack(&cl); |
| |
| for_each_cache(ca, c, i) |
| c->nbuckets += ca->sb.nbuckets; |
| set_gc_sectors(c); |
| |
| if (CACHE_SYNC(&c->sb)) { |
| LIST_HEAD(journal); |
| struct bkey *k; |
| struct jset *j; |
| |
| err = "cannot allocate memory for journal"; |
| if (bch_journal_read(c, &journal)) |
| goto err; |
| |
| pr_debug("btree_journal_read() done"); |
| |
| err = "no journal entries found"; |
| if (list_empty(&journal)) |
| goto err; |
| |
| j = &list_entry(journal.prev, struct journal_replay, list)->j; |
| |
| err = "IO error reading priorities"; |
| for_each_cache(ca, c, i) |
| prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]); |
| |
| /* |
| * If prio_read() fails it'll call cache_set_error and we'll |
| * tear everything down right away, but if we perhaps checked |
| * sooner we could avoid journal replay. |
| */ |
| |
| k = &j->btree_root; |
| |
| err = "bad btree root"; |
| if (__bch_btree_ptr_invalid(c, k)) |
| goto err; |
| |
| err = "error reading btree root"; |
| c->root = bch_btree_node_get(c, NULL, k, j->btree_level, true, NULL); |
| if (IS_ERR_OR_NULL(c->root)) |
| goto err; |
| |
| list_del_init(&c->root->list); |
| rw_unlock(true, c->root); |
| |
| err = uuid_read(c, j, &cl); |
| if (err) |
| goto err; |
| |
| err = "error in recovery"; |
| if (bch_btree_check(c)) |
| goto err; |
| |
| bch_journal_mark(c, &journal); |
| bch_initial_gc_finish(c); |
| pr_debug("btree_check() done"); |
| |
| /* |
| * bcache_journal_next() can't happen sooner, or |
| * btree_gc_finish() will give spurious errors about last_gc > |
| * gc_gen - this is a hack but oh well. |
| */ |
| bch_journal_next(&c->journal); |
| |
| err = "error starting allocator thread"; |
| for_each_cache(ca, c, i) |
| if (bch_cache_allocator_start(ca)) |
| goto err; |
| |
| /* |
| * First place it's safe to allocate: btree_check() and |
| * btree_gc_finish() have to run before we have buckets to |
| * allocate, and bch_bucket_alloc_set() might cause a journal |
| * entry to be written so bcache_journal_next() has to be called |
| * first. |
| * |
| * If the uuids were in the old format we have to rewrite them |
| * before the next journal entry is written: |
| */ |
| if (j->version < BCACHE_JSET_VERSION_UUID) |
| __uuid_write(c); |
| |
| bch_journal_replay(c, &journal); |
| } else { |
| pr_notice("invalidating existing data"); |
| |
| for_each_cache(ca, c, i) { |
| unsigned j; |
| |
| ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7, |
| 2, SB_JOURNAL_BUCKETS); |
| |
| for (j = 0; j < ca->sb.keys; j++) |
| ca->sb.d[j] = ca->sb.first_bucket + j; |
| } |
| |
| bch_initial_gc_finish(c); |
| |
| err = "error starting allocator thread"; |
| for_each_cache(ca, c, i) |
| if (bch_cache_allocator_start(ca)) |
| goto err; |
| |
| mutex_lock(&c->bucket_lock); |
| for_each_cache(ca, c, i) |
| bch_prio_write(ca); |
| mutex_unlock(&c->bucket_lock); |
| |
| err = "cannot allocate new UUID bucket"; |
| if (__uuid_write(c)) |
| goto err; |
| |
| err = "cannot allocate new btree root"; |
| c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL); |
| if (IS_ERR_OR_NULL(c->root)) |
| goto err; |
| |
| mutex_lock(&c->root->write_lock); |
| bkey_copy_key(&c->root->key, &MAX_KEY); |
| bch_btree_node_write(c->root, &cl); |
| mutex_unlock(&c->root->write_lock); |
| |
| bch_btree_set_root(c->root); |
| rw_unlock(true, c->root); |
| |
| /* |
| * We don't want to write the first journal entry until |
| * everything is set up - fortunately journal entries won't be |
| * written until the SET_CACHE_SYNC() here: |
| */ |
| SET_CACHE_SYNC(&c->sb, true); |
| |
| bch_journal_next(&c->journal); |
| bch_journal_meta(c, &cl); |
| } |
| |
| err = "error starting gc thread"; |
| if (bch_gc_thread_start(c)) |
| goto err; |
| |
| closure_sync(&cl); |
| c->sb.last_mount = get_seconds(); |
| bcache_write_super(c); |
| |
| list_for_each_entry_safe(dc, t, &uncached_devices, list) |
| bch_cached_dev_attach(dc, c); |
| |
| flash_devs_run(c); |
| |
| set_bit(CACHE_SET_RUNNING, &c->flags); |
| return; |
| err: |
| closure_sync(&cl); |
| /* XXX: test this, it's broken */ |
| bch_cache_set_error(c, "%s", err); |
| } |
| |
| static bool can_attach_cache(struct cache *ca, struct cache_set *c) |
| { |
| return ca->sb.block_size == c->sb.block_size && |
| ca->sb.bucket_size == c->sb.bucket_size && |
| ca->sb.nr_in_set == c->sb.nr_in_set; |
| } |
| |
| static const char *register_cache_set(struct cache *ca) |
| { |
| char buf[12]; |
| const char *err = "cannot allocate memory"; |
| struct cache_set *c; |
| |
| list_for_each_entry(c, &bch_cache_sets, list) |
| if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) { |
| if (c->cache[ca->sb.nr_this_dev]) |
| return "duplicate cache set member"; |
| |
| if (!can_attach_cache(ca, c)) |
| return "cache sb does not match set"; |
| |
| if (!CACHE_SYNC(&ca->sb)) |
| SET_CACHE_SYNC(&c->sb, false); |
| |
| goto found; |
| } |
| |
| c = bch_cache_set_alloc(&ca->sb); |
| if (!c) |
| return err; |
| |
| err = "error creating kobject"; |
| if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) || |
| kobject_add(&c->internal, &c->kobj, "internal")) |
| goto err; |
| |
| if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj)) |
| goto err; |
| |
| bch_debug_init_cache_set(c); |
| |
| list_add(&c->list, &bch_cache_sets); |
| found: |
| sprintf(buf, "cache%i", ca->sb.nr_this_dev); |
| if (sysfs_create_link(&ca->kobj, &c->kobj, "set") || |
| sysfs_create_link(&c->kobj, &ca->kobj, buf)) |
| goto err; |
| |
| if (ca->sb.seq > c->sb.seq) { |
| c->sb.version = ca->sb.version; |
| memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16); |
| c->sb.flags = ca->sb.flags; |
| c->sb.seq = ca->sb.seq; |
| pr_debug("set version = %llu", c->sb.version); |
| } |
| |
| kobject_get(&ca->kobj); |
| ca->set = c; |
| ca->set->cache[ca->sb.nr_this_dev] = ca; |
| c->cache_by_alloc[c->caches_loaded++] = ca; |
| |
| if (c->caches_loaded == c->sb.nr_in_set) |
| run_cache_set(c); |
| |
| return NULL; |
| err: |
| bch_cache_set_unregister(c); |
| return err; |
| } |
| |
| /* Cache device */ |
| |
| void bch_cache_release(struct kobject *kobj) |
| { |
| struct cache *ca = container_of(kobj, struct cache, kobj); |
| unsigned i; |
| |
| if (ca->set) { |
| BUG_ON(ca->set->cache[ca->sb.nr_this_dev] != ca); |
| ca->set->cache[ca->sb.nr_this_dev] = NULL; |
| } |
| |
| free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca))); |
| kfree(ca->prio_buckets); |
| vfree(ca->buckets); |
| |
| free_heap(&ca->heap); |
| free_fifo(&ca->free_inc); |
| |
| for (i = 0; i < RESERVE_NR; i++) |
| free_fifo(&ca->free[i]); |
| |
| if (ca->sb_bio.bi_inline_vecs[0].bv_page) |
| put_page(ca->sb_bio.bi_io_vec[0].bv_page); |
| |
| if (!IS_ERR_OR_NULL(ca->bdev)) |
| blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
| |
| kfree(ca); |
| module_put(THIS_MODULE); |
| } |
| |
| static int cache_alloc(struct cache *ca) |
| { |
| size_t free; |
| struct bucket *b; |
| |
| __module_get(THIS_MODULE); |
| kobject_init(&ca->kobj, &bch_cache_ktype); |
| |
| bio_init(&ca->journal.bio, ca->journal.bio.bi_inline_vecs, 8); |
| |
| free = roundup_pow_of_two(ca->sb.nbuckets) >> 10; |
| |
| if (!init_fifo(&ca->free[RESERVE_BTREE], 8, GFP_KERNEL) || |
| !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) || |
| !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) || |
| !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) || |
| !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) || |
| !init_heap(&ca->heap, free << 3, GFP_KERNEL) || |
| !(ca->buckets = vzalloc(sizeof(struct bucket) * |
| ca->sb.nbuckets)) || |
| !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) * |
| 2, GFP_KERNEL)) || |
| !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca))) |
| return -ENOMEM; |
| |
| ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca); |
| |
| for_each_bucket(b, ca) |
| atomic_set(&b->pin, 0); |
| |
| return 0; |
| } |
| |
| static int register_cache(struct cache_sb *sb, struct page *sb_page, |
| struct block_device *bdev, struct cache *ca) |
| { |
| char name[BDEVNAME_SIZE]; |
| const char *err = NULL; /* must be set for any error case */ |
| int ret = 0; |
| |
| memcpy(&ca->sb, sb, sizeof(struct cache_sb)); |
| ca->bdev = bdev; |
| ca->bdev->bd_holder = ca; |
| |
| bio_init(&ca->sb_bio, ca->sb_bio.bi_inline_vecs, 1); |
| ca->sb_bio.bi_io_vec[0].bv_page = sb_page; |
| get_page(sb_page); |
| |
| if (blk_queue_discard(bdev_get_queue(ca->bdev))) |
| ca->discard = CACHE_DISCARD(&ca->sb); |
| |
| ret = cache_alloc(ca); |
| if (ret != 0) { |
| if (ret == -ENOMEM) |
| err = "cache_alloc(): -ENOMEM"; |
| else |
| err = "cache_alloc(): unknown error"; |
| goto err; |
| } |
| |
| if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache")) { |
| err = "error calling kobject_add"; |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| mutex_lock(&bch_register_lock); |
| err = register_cache_set(ca); |
| mutex_unlock(&bch_register_lock); |
| |
| if (err) { |
| ret = -ENODEV; |
| goto out; |
| } |
| |
| pr_info("registered cache device %s", bdevname(bdev, name)); |
| |
| out: |
| kobject_put(&ca->kobj); |
| |
| err: |
| if (err) |
| pr_notice("error opening %s: %s", bdevname(bdev, name), err); |
| |
| return ret; |
| } |
| |
| /* Global interfaces/init */ |
| |
| static ssize_t register_bcache(struct kobject *, struct kobj_attribute *, |
| const char *, size_t); |
| |
| kobj_attribute_write(register, register_bcache); |
| kobj_attribute_write(register_quiet, register_bcache); |
| |
| static bool bch_is_open_backing(struct block_device *bdev) { |
| struct cache_set *c, *tc; |
| struct cached_dev *dc, *t; |
| |
| list_for_each_entry_safe(c, tc, &bch_cache_sets, list) |
| list_for_each_entry_safe(dc, t, &c->cached_devs, list) |
| if (dc->bdev == bdev) |
| return true; |
| list_for_each_entry_safe(dc, t, &uncached_devices, list) |
| if (dc->bdev == bdev) |
| return true; |
| return false; |
| } |
| |
| static bool bch_is_open_cache(struct block_device *bdev) { |
| struct cache_set *c, *tc; |
| struct cache *ca; |
| unsigned i; |
| |
| list_for_each_entry_safe(c, tc, &bch_cache_sets, list) |
| for_each_cache(ca, c, i) |
| if (ca->bdev == bdev) |
| return true; |
| return false; |
| } |
| |
| static bool bch_is_open(struct block_device *bdev) { |
| return bch_is_open_cache(bdev) || bch_is_open_backing(bdev); |
| } |
| |
| static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, |
| const char *buffer, size_t size) |
| { |
| ssize_t ret = size; |
| const char *err = "cannot allocate memory"; |
| char *path = NULL; |
| struct cache_sb *sb = NULL; |
| struct block_device *bdev = NULL; |
| struct page *sb_page = NULL; |
| |
| if (!try_module_get(THIS_MODULE)) |
| return -EBUSY; |
| |
| if (!(path = kstrndup(buffer, size, GFP_KERNEL)) || |
| !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL))) |
| goto err; |
| |
| err = "failed to open device"; |
| bdev = blkdev_get_by_path(strim(path), |
| FMODE_READ|FMODE_WRITE|FMODE_EXCL, |
| sb); |
| if (IS_ERR(bdev)) { |
| if (bdev == ERR_PTR(-EBUSY)) { |
| bdev = lookup_bdev(strim(path)); |
| mutex_lock(&bch_register_lock); |
| if (!IS_ERR(bdev) && bch_is_open(bdev)) |
| err = "device already registered"; |
| else |
| err = "device busy"; |
| mutex_unlock(&bch_register_lock); |
| if (attr == &ksysfs_register_quiet) |
| goto out; |
| } |
| goto err; |
| } |
| |
| err = "failed to set blocksize"; |
| if (set_blocksize(bdev, 4096)) |
| goto err_close; |
| |
| err = read_super(sb, bdev, &sb_page); |
| if (err) |
| goto err_close; |
| |
| if (SB_IS_BDEV(sb)) { |
| struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL); |
| if (!dc) |
| goto err_close; |
| |
| mutex_lock(&bch_register_lock); |
| register_bdev(sb, sb_page, bdev, dc); |
| mutex_unlock(&bch_register_lock); |
| } else { |
| struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL); |
| if (!ca) |
| goto err_close; |
| |
| if (register_cache(sb, sb_page, bdev, ca) != 0) |
| goto err_close; |
| } |
| out: |
| if (sb_page) |
| put_page(sb_page); |
| kfree(sb); |
| kfree(path); |
| module_put(THIS_MODULE); |
| return ret; |
| |
| err_close: |
| blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
| err: |
| pr_info("error opening %s: %s", path, err); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x) |
| { |
| if (code == SYS_DOWN || |
| code == SYS_HALT || |
| code == SYS_POWER_OFF) { |
| DEFINE_WAIT(wait); |
| unsigned long start = jiffies; |
| bool stopped = false; |
| |
| struct cache_set *c, *tc; |
| struct cached_dev *dc, *tdc; |
| |
| mutex_lock(&bch_register_lock); |
| |
| if (list_empty(&bch_cache_sets) && |
| list_empty(&uncached_devices)) |
| goto out; |
| |
| pr_info("Stopping all devices:"); |
| |
| list_for_each_entry_safe(c, tc, &bch_cache_sets, list) |
| bch_cache_set_stop(c); |
| |
| list_for_each_entry_safe(dc, tdc, &uncached_devices, list) |
| bcache_device_stop(&dc->disk); |
| |
| /* What's a condition variable? */ |
| while (1) { |
| long timeout = start + 2 * HZ - jiffies; |
| |
| stopped = list_empty(&bch_cache_sets) && |
| list_empty(&uncached_devices); |
| |
| if (timeout < 0 || stopped) |
| break; |
| |
| prepare_to_wait(&unregister_wait, &wait, |
| TASK_UNINTERRUPTIBLE); |
| |
| mutex_unlock(&bch_register_lock); |
| schedule_timeout(timeout); |
| mutex_lock(&bch_register_lock); |
| } |
| |
| finish_wait(&unregister_wait, &wait); |
| |
| if (stopped) |
| pr_info("All devices stopped"); |
| else |
| pr_notice("Timeout waiting for devices to be closed"); |
| out: |
| mutex_unlock(&bch_register_lock); |
| } |
| |
| return NOTIFY_DONE; |
| } |
| |
| static struct notifier_block reboot = { |
| .notifier_call = bcache_reboot, |
| .priority = INT_MAX, /* before any real devices */ |
| }; |
| |
| static void bcache_exit(void) |
| { |
| bch_debug_exit(); |
| bch_request_exit(); |
| if (bcache_kobj) |
| kobject_put(bcache_kobj); |
| if (bcache_wq) |
| destroy_workqueue(bcache_wq); |
| if (bcache_major) |
| unregister_blkdev(bcache_major, "bcache"); |
| unregister_reboot_notifier(&reboot); |
| } |
| |
| static int __init bcache_init(void) |
| { |
| static const struct attribute *files[] = { |
| &ksysfs_register.attr, |
| &ksysfs_register_quiet.attr, |
| NULL |
| }; |
| |
| mutex_init(&bch_register_lock); |
| init_waitqueue_head(&unregister_wait); |
| register_reboot_notifier(&reboot); |
| closure_debug_init(); |
| |
| bcache_major = register_blkdev(0, "bcache"); |
| if (bcache_major < 0) { |
| unregister_reboot_notifier(&reboot); |
| return bcache_major; |
| } |
| |
| if (!(bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0)) || |
| !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) || |
| sysfs_create_files(bcache_kobj, files) || |
| bch_request_init() || |
| bch_debug_init(bcache_kobj)) |
| goto err; |
| |
| return 0; |
| err: |
| bcache_exit(); |
| return -ENOMEM; |
| } |
| |
| module_exit(bcache_exit); |
| module_init(bcache_init); |