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- /*
- * 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)
- /* 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->block_size = le16_to_cpu(s->block_size);
- 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_rw = REQ_SYNC|REQ_META;
- bio->bi_iter.bi_size = SB_SIZE;
- 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(REQ_WRITE, 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, unsigned long rw,
- 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_rw = REQ_SYNC|REQ_META|rw;
- bio->bi_iter.bi_size = KEY_SIZE(k) << 9;
- bio->bi_end_io = uuid_endio;
- bio->bi_private = cl;
- bch_bio_map(bio, c->uuids);
- bch_submit_bbio(bio, c, k, i);
- if (!(rw & WRITE))
- break;
- }
- bch_extent_to_text(buf, sizeof(buf), k);
- pr_debug("%s UUIDs at %s", rw & REQ_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, READ_SYNC, 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_WRITE, &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, unsigned long rw)
- {
- 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_rw = REQ_SYNC|REQ_META|rw;
- bio->bi_iter.bi_size = bucket_bytes(ca);
- bio->bi_end_io = prio_endio;
- bio->bi_private = ca;
- 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_WRITE);
- 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, READ_SYNC);
- 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");
- 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;
- if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
- !(d->disk = alloc_disk(1))) {
- 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_flush(q, REQ_FLUSH|REQ_FUA);
- 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);
- cancel_delayed_work_sync(&dc->writeback_rate_update);
- if (!IS_ERR_OR_NULL(dc->writeback_thread)) {
- kthread_stop(dc->writeback_thread);
- dc->writeback_thread = NULL;
- }
- 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,
- uint8_t *set_uuid)
- {
- uint32_t rtime = cpu_to_le32(get_seconds());
- struct uuid_entry *u;
- char buf[BDEVNAME_SIZE];
- struct cached_dev *exist_dc, *t;
- bdevname(dc->bdev, buf);
- if ((set_uuid && memcmp(set_uuid, c->sb.set_uuid, 16)) ||
- (!set_uuid && 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;
- }
- /* Check whether already attached */
- list_for_each_entry_safe(exist_dc, t, &c->cached_devs, list) {
- if (!memcmp(dc->sb.uuid, exist_dc->sb.uuid, 16)) {
- pr_err("Tried to attach %s but duplicate UUID already attached",
- 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->disk);
- 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);
- if (dc->writeback_write_wq)
- destroy_workqueue(dc->writeback_write_wq);
- 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_max_vecs = 1;
- dc->sb_bio.bi_io_vec = dc->sb_bio.bi_inline_vecs;
- 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, NULL);
- 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_sectors_dirty_init(d);
- 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 = create_workqueue("bcache_gc")) ||
- 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, NULL);
- 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_sb *sb, struct cache *ca)
- {
- size_t free;
- size_t btree_buckets;
- struct bucket *b;
- __module_get(THIS_MODULE);
- kobject_init(&ca->kobj, &bch_cache_ktype);
- bio_init(&ca->journal.bio);
- ca->journal.bio.bi_max_vecs = 8;
- ca->journal.bio.bi_io_vec = ca->journal.bio.bi_inline_vecs;
- /*
- * when ca->sb.njournal_buckets is not zero, journal exists,
- * and in bch_journal_replay(), tree node may split,
- * so bucket of RESERVE_BTREE type is needed,
- * the worst situation is all journal buckets are valid journal,
- * and all the keys need to replay,
- * so the number of RESERVE_BTREE type buckets should be as much
- * as journal buckets
- */
- btree_buckets = ca->sb.njournal_buckets ?: 8;
- free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
- if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, 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;
- 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_max_vecs = 1;
- ca->sb_bio.bi_io_vec = ca->sb_bio.bi_inline_vecs;
- 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(sb, ca);
- if (ret != 0)
- 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 (!IS_ERR(bdev))
- bdput(bdev);
- 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);
- mutex_destroy(&bch_register_lock);
- }
- 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);
- mutex_destroy(&bch_register_lock);
- return bcache_major;
- }
- if (!(bcache_wq = create_workqueue("bcache")) ||
- !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
- bch_request_init() ||
- bch_debug_init(bcache_kobj) ||
- sysfs_create_files(bcache_kobj, files))
- goto err;
- return 0;
- err:
- bcache_exit();
- return -ENOMEM;
- }
- module_exit(bcache_exit);
- module_init(bcache_init);
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