2 * bcache setup/teardown code, and some metadata io - read a superblock and
3 * figure out what to do with it.
5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6 * Copyright 2012 Google, Inc.
13 #include "writeback.h"
15 #include <linux/blkdev.h>
16 #include <linux/buffer_head.h>
17 #include <linux/debugfs.h>
18 #include <linux/genhd.h>
19 #include <linux/kthread.h>
20 #include <linux/module.h>
21 #include <linux/random.h>
22 #include <linux/reboot.h>
23 #include <linux/sysfs.h>
25 MODULE_LICENSE("GPL");
26 MODULE_AUTHOR("Kent Overstreet <kent.overstreet@gmail.com>");
28 static const char bcache_magic[] = {
29 0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
30 0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81
33 static const char invalid_uuid[] = {
34 0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78,
35 0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99
38 /* Default is -1; we skip past it for struct cached_dev's cache mode */
39 const char * const bch_cache_modes[] = {
48 struct uuid_entry_v0 {
57 static struct kobject *bcache_kobj;
58 struct mutex bch_register_lock;
59 LIST_HEAD(bch_cache_sets);
60 static LIST_HEAD(uncached_devices);
62 static int bcache_major, bcache_minor;
63 static wait_queue_head_t unregister_wait;
64 struct workqueue_struct *bcache_wq;
66 #define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE)
68 static void bio_split_pool_free(struct bio_split_pool *p)
70 if (p->bio_split_hook)
71 mempool_destroy(p->bio_split_hook);
74 bioset_free(p->bio_split);
77 static int bio_split_pool_init(struct bio_split_pool *p)
79 p->bio_split = bioset_create(4, 0);
83 p->bio_split_hook = mempool_create_kmalloc_pool(4,
84 sizeof(struct bio_split_hook));
85 if (!p->bio_split_hook)
93 static const char *read_super(struct cache_sb *sb, struct block_device *bdev,
98 struct buffer_head *bh = __bread(bdev, 1, SB_SIZE);
104 s = (struct cache_sb *) bh->b_data;
106 sb->offset = le64_to_cpu(s->offset);
107 sb->version = le64_to_cpu(s->version);
109 memcpy(sb->magic, s->magic, 16);
110 memcpy(sb->uuid, s->uuid, 16);
111 memcpy(sb->set_uuid, s->set_uuid, 16);
112 memcpy(sb->label, s->label, SB_LABEL_SIZE);
114 sb->flags = le64_to_cpu(s->flags);
115 sb->seq = le64_to_cpu(s->seq);
116 sb->last_mount = le32_to_cpu(s->last_mount);
117 sb->first_bucket = le16_to_cpu(s->first_bucket);
118 sb->keys = le16_to_cpu(s->keys);
120 for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
121 sb->d[i] = le64_to_cpu(s->d[i]);
123 pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u",
124 sb->version, sb->flags, sb->seq, sb->keys);
126 err = "Not a bcache superblock";
127 if (sb->offset != SB_SECTOR)
130 if (memcmp(sb->magic, bcache_magic, 16))
133 err = "Too many journal buckets";
134 if (sb->keys > SB_JOURNAL_BUCKETS)
137 err = "Bad checksum";
138 if (s->csum != csum_set(s))
142 if (bch_is_zero(sb->uuid, 16))
145 sb->block_size = le16_to_cpu(s->block_size);
147 err = "Superblock block size smaller than device block size";
148 if (sb->block_size << 9 < bdev_logical_block_size(bdev))
151 switch (sb->version) {
152 case BCACHE_SB_VERSION_BDEV:
153 sb->data_offset = BDEV_DATA_START_DEFAULT;
155 case BCACHE_SB_VERSION_BDEV_WITH_OFFSET:
156 sb->data_offset = le64_to_cpu(s->data_offset);
158 err = "Bad data offset";
159 if (sb->data_offset < BDEV_DATA_START_DEFAULT)
163 case BCACHE_SB_VERSION_CDEV:
164 case BCACHE_SB_VERSION_CDEV_WITH_UUID:
165 sb->nbuckets = le64_to_cpu(s->nbuckets);
166 sb->block_size = le16_to_cpu(s->block_size);
167 sb->bucket_size = le16_to_cpu(s->bucket_size);
169 sb->nr_in_set = le16_to_cpu(s->nr_in_set);
170 sb->nr_this_dev = le16_to_cpu(s->nr_this_dev);
172 err = "Too many buckets";
173 if (sb->nbuckets > LONG_MAX)
176 err = "Not enough buckets";
177 if (sb->nbuckets < 1 << 7)
180 err = "Bad block/bucket size";
181 if (!is_power_of_2(sb->block_size) ||
182 sb->block_size > PAGE_SECTORS ||
183 !is_power_of_2(sb->bucket_size) ||
184 sb->bucket_size < PAGE_SECTORS)
187 err = "Invalid superblock: device too small";
188 if (get_capacity(bdev->bd_disk) < sb->bucket_size * sb->nbuckets)
192 if (bch_is_zero(sb->set_uuid, 16))
195 err = "Bad cache device number in set";
196 if (!sb->nr_in_set ||
197 sb->nr_in_set <= sb->nr_this_dev ||
198 sb->nr_in_set > MAX_CACHES_PER_SET)
201 err = "Journal buckets not sequential";
202 for (i = 0; i < sb->keys; i++)
203 if (sb->d[i] != sb->first_bucket + i)
206 err = "Too many journal buckets";
207 if (sb->first_bucket + sb->keys > sb->nbuckets)
210 err = "Invalid superblock: first bucket comes before end of super";
211 if (sb->first_bucket * sb->bucket_size < 16)
216 err = "Unsupported superblock version";
220 sb->last_mount = get_seconds();
223 get_page(bh->b_page);
230 static void write_bdev_super_endio(struct bio *bio, int error)
232 struct cached_dev *dc = bio->bi_private;
233 /* XXX: error checking */
235 closure_put(&dc->sb_write.cl);
238 static void __write_super(struct cache_sb *sb, struct bio *bio)
240 struct cache_sb *out = page_address(bio->bi_io_vec[0].bv_page);
243 bio->bi_sector = SB_SECTOR;
244 bio->bi_rw = REQ_SYNC|REQ_META;
245 bio->bi_size = SB_SIZE;
246 bch_bio_map(bio, NULL);
248 out->offset = cpu_to_le64(sb->offset);
249 out->version = cpu_to_le64(sb->version);
251 memcpy(out->uuid, sb->uuid, 16);
252 memcpy(out->set_uuid, sb->set_uuid, 16);
253 memcpy(out->label, sb->label, SB_LABEL_SIZE);
255 out->flags = cpu_to_le64(sb->flags);
256 out->seq = cpu_to_le64(sb->seq);
258 out->last_mount = cpu_to_le32(sb->last_mount);
259 out->first_bucket = cpu_to_le16(sb->first_bucket);
260 out->keys = cpu_to_le16(sb->keys);
262 for (i = 0; i < sb->keys; i++)
263 out->d[i] = cpu_to_le64(sb->d[i]);
265 out->csum = csum_set(out);
267 pr_debug("ver %llu, flags %llu, seq %llu",
268 sb->version, sb->flags, sb->seq);
270 submit_bio(REQ_WRITE, bio);
273 void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent)
275 struct closure *cl = &dc->sb_write.cl;
276 struct bio *bio = &dc->sb_bio;
278 closure_lock(&dc->sb_write, parent);
281 bio->bi_bdev = dc->bdev;
282 bio->bi_end_io = write_bdev_super_endio;
283 bio->bi_private = dc;
286 __write_super(&dc->sb, bio);
291 static void write_super_endio(struct bio *bio, int error)
293 struct cache *ca = bio->bi_private;
295 bch_count_io_errors(ca, error, "writing superblock");
296 closure_put(&ca->set->sb_write.cl);
299 void bcache_write_super(struct cache_set *c)
301 struct closure *cl = &c->sb_write.cl;
305 closure_lock(&c->sb_write, &c->cl);
309 for_each_cache(ca, c, i) {
310 struct bio *bio = &ca->sb_bio;
312 ca->sb.version = BCACHE_SB_VERSION_CDEV_WITH_UUID;
313 ca->sb.seq = c->sb.seq;
314 ca->sb.last_mount = c->sb.last_mount;
316 SET_CACHE_SYNC(&ca->sb, CACHE_SYNC(&c->sb));
319 bio->bi_bdev = ca->bdev;
320 bio->bi_end_io = write_super_endio;
321 bio->bi_private = ca;
324 __write_super(&ca->sb, bio);
332 static void uuid_endio(struct bio *bio, int error)
334 struct closure *cl = bio->bi_private;
335 struct cache_set *c = container_of(cl, struct cache_set, uuid_write.cl);
337 cache_set_err_on(error, c, "accessing uuids");
338 bch_bbio_free(bio, c);
342 static void uuid_io(struct cache_set *c, unsigned long rw,
343 struct bkey *k, struct closure *parent)
345 struct closure *cl = &c->uuid_write.cl;
346 struct uuid_entry *u;
351 closure_lock(&c->uuid_write, parent);
353 for (i = 0; i < KEY_PTRS(k); i++) {
354 struct bio *bio = bch_bbio_alloc(c);
356 bio->bi_rw = REQ_SYNC|REQ_META|rw;
357 bio->bi_size = KEY_SIZE(k) << 9;
359 bio->bi_end_io = uuid_endio;
360 bio->bi_private = cl;
361 bch_bio_map(bio, c->uuids);
363 bch_submit_bbio(bio, c, k, i);
369 bch_bkey_to_text(buf, sizeof(buf), k);
370 pr_debug("%s UUIDs at %s", rw & REQ_WRITE ? "wrote" : "read", buf);
372 for (u = c->uuids; u < c->uuids + c->nr_uuids; u++)
373 if (!bch_is_zero(u->uuid, 16))
374 pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u",
375 u - c->uuids, u->uuid, u->label,
376 u->first_reg, u->last_reg, u->invalidated);
381 static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl)
383 struct bkey *k = &j->uuid_bucket;
385 if (__bch_ptr_invalid(c, 1, k))
386 return "bad uuid pointer";
388 bkey_copy(&c->uuid_bucket, k);
389 uuid_io(c, READ_SYNC, k, cl);
391 if (j->version < BCACHE_JSET_VERSION_UUIDv1) {
392 struct uuid_entry_v0 *u0 = (void *) c->uuids;
393 struct uuid_entry *u1 = (void *) c->uuids;
399 * Since the new uuid entry is bigger than the old, we have to
400 * convert starting at the highest memory address and work down
401 * in order to do it in place
404 for (i = c->nr_uuids - 1;
407 memcpy(u1[i].uuid, u0[i].uuid, 16);
408 memcpy(u1[i].label, u0[i].label, 32);
410 u1[i].first_reg = u0[i].first_reg;
411 u1[i].last_reg = u0[i].last_reg;
412 u1[i].invalidated = u0[i].invalidated;
422 static int __uuid_write(struct cache_set *c)
426 closure_init_stack(&cl);
428 lockdep_assert_held(&bch_register_lock);
430 if (bch_bucket_alloc_set(c, WATERMARK_METADATA, &k.key, 1, true))
433 SET_KEY_SIZE(&k.key, c->sb.bucket_size);
434 uuid_io(c, REQ_WRITE, &k.key, &cl);
437 bkey_copy(&c->uuid_bucket, &k.key);
438 __bkey_put(c, &k.key);
442 int bch_uuid_write(struct cache_set *c)
444 int ret = __uuid_write(c);
447 bch_journal_meta(c, NULL);
452 static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid)
454 struct uuid_entry *u;
457 u < c->uuids + c->nr_uuids; u++)
458 if (!memcmp(u->uuid, uuid, 16))
464 static struct uuid_entry *uuid_find_empty(struct cache_set *c)
466 static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
467 return uuid_find(c, zero_uuid);
471 * Bucket priorities/gens:
473 * For each bucket, we store on disk its
477 * See alloc.c for an explanation of the gen. The priority is used to implement
478 * lru (and in the future other) cache replacement policies; for most purposes
479 * it's just an opaque integer.
481 * The gens and the priorities don't have a whole lot to do with each other, and
482 * it's actually the gens that must be written out at specific times - it's no
483 * big deal if the priorities don't get written, if we lose them we just reuse
484 * buckets in suboptimal order.
486 * On disk they're stored in a packed array, and in as many buckets are required
487 * to fit them all. The buckets we use to store them form a list; the journal
488 * header points to the first bucket, the first bucket points to the second
491 * This code is used by the allocation code; periodically (whenever it runs out
492 * of buckets to allocate from) the allocation code will invalidate some
493 * buckets, but it can't use those buckets until their new gens are safely on
497 static void prio_endio(struct bio *bio, int error)
499 struct cache *ca = bio->bi_private;
501 cache_set_err_on(error, ca->set, "accessing priorities");
502 bch_bbio_free(bio, ca->set);
503 closure_put(&ca->prio);
506 static void prio_io(struct cache *ca, uint64_t bucket, unsigned long rw)
508 struct closure *cl = &ca->prio;
509 struct bio *bio = bch_bbio_alloc(ca->set);
511 closure_init_stack(cl);
513 bio->bi_sector = bucket * ca->sb.bucket_size;
514 bio->bi_bdev = ca->bdev;
515 bio->bi_rw = REQ_SYNC|REQ_META|rw;
516 bio->bi_size = bucket_bytes(ca);
518 bio->bi_end_io = prio_endio;
519 bio->bi_private = ca;
520 bch_bio_map(bio, ca->disk_buckets);
522 closure_bio_submit(bio, &ca->prio, ca);
526 #define buckets_free(c) "free %zu, free_inc %zu, unused %zu", \
527 fifo_used(&c->free), fifo_used(&c->free_inc), fifo_used(&c->unused)
529 void bch_prio_write(struct cache *ca)
535 closure_init_stack(&cl);
537 lockdep_assert_held(&ca->set->bucket_lock);
539 for (b = ca->buckets;
540 b < ca->buckets + ca->sb.nbuckets; b++)
541 b->disk_gen = b->gen;
543 ca->disk_buckets->seq++;
545 atomic_long_add(ca->sb.bucket_size * prio_buckets(ca),
546 &ca->meta_sectors_written);
548 pr_debug("free %zu, free_inc %zu, unused %zu", fifo_used(&ca->free),
549 fifo_used(&ca->free_inc), fifo_used(&ca->unused));
551 for (i = prio_buckets(ca) - 1; i >= 0; --i) {
553 struct prio_set *p = ca->disk_buckets;
554 struct bucket_disk *d = p->data;
555 struct bucket_disk *end = d + prios_per_bucket(ca);
557 for (b = ca->buckets + i * prios_per_bucket(ca);
558 b < ca->buckets + ca->sb.nbuckets && d < end;
560 d->prio = cpu_to_le16(b->prio);
564 p->next_bucket = ca->prio_buckets[i + 1];
565 p->magic = pset_magic(ca);
566 p->csum = bch_crc64(&p->magic, bucket_bytes(ca) - 8);
568 bucket = bch_bucket_alloc(ca, WATERMARK_PRIO, true);
569 BUG_ON(bucket == -1);
571 mutex_unlock(&ca->set->bucket_lock);
572 prio_io(ca, bucket, REQ_WRITE);
573 mutex_lock(&ca->set->bucket_lock);
575 ca->prio_buckets[i] = bucket;
576 atomic_dec_bug(&ca->buckets[bucket].pin);
579 mutex_unlock(&ca->set->bucket_lock);
581 bch_journal_meta(ca->set, &cl);
584 mutex_lock(&ca->set->bucket_lock);
586 ca->need_save_prio = 0;
589 * Don't want the old priorities to get garbage collected until after we
590 * finish writing the new ones, and they're journalled
592 for (i = 0; i < prio_buckets(ca); i++)
593 ca->prio_last_buckets[i] = ca->prio_buckets[i];
596 static void prio_read(struct cache *ca, uint64_t bucket)
598 struct prio_set *p = ca->disk_buckets;
599 struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d;
601 unsigned bucket_nr = 0;
603 for (b = ca->buckets;
604 b < ca->buckets + ca->sb.nbuckets;
607 ca->prio_buckets[bucket_nr] = bucket;
608 ca->prio_last_buckets[bucket_nr] = bucket;
611 prio_io(ca, bucket, READ_SYNC);
613 if (p->csum != bch_crc64(&p->magic, bucket_bytes(ca) - 8))
614 pr_warn("bad csum reading priorities");
616 if (p->magic != pset_magic(ca))
617 pr_warn("bad magic reading priorities");
619 bucket = p->next_bucket;
623 b->prio = le16_to_cpu(d->prio);
624 b->gen = b->disk_gen = b->last_gc = b->gc_gen = d->gen;
630 static int open_dev(struct block_device *b, fmode_t mode)
632 struct bcache_device *d = b->bd_disk->private_data;
633 if (atomic_read(&d->closing))
640 static void release_dev(struct gendisk *b, fmode_t mode)
642 struct bcache_device *d = b->private_data;
646 static int ioctl_dev(struct block_device *b, fmode_t mode,
647 unsigned int cmd, unsigned long arg)
649 struct bcache_device *d = b->bd_disk->private_data;
650 return d->ioctl(d, mode, cmd, arg);
653 static const struct block_device_operations bcache_ops = {
655 .release = release_dev,
657 .owner = THIS_MODULE,
660 void bcache_device_stop(struct bcache_device *d)
662 if (!atomic_xchg(&d->closing, 1))
663 closure_queue(&d->cl);
666 static void bcache_device_unlink(struct bcache_device *d)
671 sysfs_remove_link(&d->c->kobj, d->name);
672 sysfs_remove_link(&d->kobj, "cache");
674 for_each_cache(ca, d->c, i)
675 bd_unlink_disk_holder(ca->bdev, d->disk);
678 static void bcache_device_link(struct bcache_device *d, struct cache_set *c,
684 for_each_cache(ca, d->c, i)
685 bd_link_disk_holder(ca->bdev, d->disk);
687 snprintf(d->name, BCACHEDEVNAME_SIZE,
688 "%s%u", name, d->id);
690 WARN(sysfs_create_link(&d->kobj, &c->kobj, "cache") ||
691 sysfs_create_link(&c->kobj, &d->kobj, d->name),
692 "Couldn't create device <-> cache set symlinks");
695 static void bcache_device_detach(struct bcache_device *d)
697 lockdep_assert_held(&bch_register_lock);
699 if (atomic_read(&d->detaching)) {
700 struct uuid_entry *u = d->c->uuids + d->id;
702 SET_UUID_FLASH_ONLY(u, 0);
703 memcpy(u->uuid, invalid_uuid, 16);
704 u->invalidated = cpu_to_le32(get_seconds());
705 bch_uuid_write(d->c);
707 atomic_set(&d->detaching, 0);
711 bcache_device_unlink(d);
713 d->c->devices[d->id] = NULL;
714 closure_put(&d->c->caching);
718 static void bcache_device_attach(struct bcache_device *d, struct cache_set *c,
721 BUG_ON(test_bit(CACHE_SET_STOPPING, &c->flags));
727 closure_get(&c->caching);
730 static void bcache_device_free(struct bcache_device *d)
732 lockdep_assert_held(&bch_register_lock);
734 pr_info("%s stopped", d->disk->disk_name);
737 bcache_device_detach(d);
738 if (d->disk && d->disk->flags & GENHD_FL_UP)
739 del_gendisk(d->disk);
740 if (d->disk && d->disk->queue)
741 blk_cleanup_queue(d->disk->queue);
745 bio_split_pool_free(&d->bio_split_hook);
746 if (d->unaligned_bvec)
747 mempool_destroy(d->unaligned_bvec);
749 bioset_free(d->bio_split);
750 if (is_vmalloc_addr(d->stripe_sectors_dirty))
751 vfree(d->stripe_sectors_dirty);
753 kfree(d->stripe_sectors_dirty);
755 closure_debug_destroy(&d->cl);
758 static int bcache_device_init(struct bcache_device *d, unsigned block_size,
761 struct request_queue *q;
765 d->stripe_size = 1 << 31;
767 d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
769 if (!d->nr_stripes || d->nr_stripes > SIZE_MAX / sizeof(atomic_t))
772 n = d->nr_stripes * sizeof(atomic_t);
773 d->stripe_sectors_dirty = n < PAGE_SIZE << 6
774 ? kzalloc(n, GFP_KERNEL)
776 if (!d->stripe_sectors_dirty)
779 if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
780 !(d->unaligned_bvec = mempool_create_kmalloc_pool(1,
781 sizeof(struct bio_vec) * BIO_MAX_PAGES)) ||
782 bio_split_pool_init(&d->bio_split_hook) ||
783 !(d->disk = alloc_disk(1)) ||
784 !(q = blk_alloc_queue(GFP_KERNEL)))
787 set_capacity(d->disk, sectors);
788 snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", bcache_minor);
790 d->disk->major = bcache_major;
791 d->disk->first_minor = bcache_minor++;
792 d->disk->fops = &bcache_ops;
793 d->disk->private_data = d;
795 blk_queue_make_request(q, NULL);
798 q->backing_dev_info.congested_data = d;
799 q->limits.max_hw_sectors = UINT_MAX;
800 q->limits.max_sectors = UINT_MAX;
801 q->limits.max_segment_size = UINT_MAX;
802 q->limits.max_segments = BIO_MAX_PAGES;
803 q->limits.max_discard_sectors = UINT_MAX;
804 q->limits.io_min = block_size;
805 q->limits.logical_block_size = block_size;
806 q->limits.physical_block_size = block_size;
807 set_bit(QUEUE_FLAG_NONROT, &d->disk->queue->queue_flags);
808 set_bit(QUEUE_FLAG_DISCARD, &d->disk->queue->queue_flags);
810 blk_queue_flush(q, REQ_FLUSH|REQ_FUA);
817 static void calc_cached_dev_sectors(struct cache_set *c)
819 uint64_t sectors = 0;
820 struct cached_dev *dc;
822 list_for_each_entry(dc, &c->cached_devs, list)
823 sectors += bdev_sectors(dc->bdev);
825 c->cached_dev_sectors = sectors;
828 void bch_cached_dev_run(struct cached_dev *dc)
830 struct bcache_device *d = &dc->disk;
831 char buf[SB_LABEL_SIZE + 1];
834 kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid),
839 memcpy(buf, dc->sb.label, SB_LABEL_SIZE);
840 buf[SB_LABEL_SIZE] = '\0';
841 env[2] = kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf);
843 if (atomic_xchg(&dc->running, 1))
847 BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) {
849 closure_init_stack(&cl);
851 SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE);
852 bch_write_bdev_super(dc, &cl);
857 bd_link_disk_holder(dc->bdev, dc->disk.disk);
858 /* won't show up in the uevent file, use udevadm monitor -e instead
859 * only class / kset properties are persistent */
860 kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env);
864 if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") ||
865 sysfs_create_link(&disk_to_dev(d->disk)->kobj, &d->kobj, "bcache"))
866 pr_debug("error creating sysfs link");
869 static void cached_dev_detach_finish(struct work_struct *w)
871 struct cached_dev *dc = container_of(w, struct cached_dev, detach);
872 char buf[BDEVNAME_SIZE];
874 closure_init_stack(&cl);
876 BUG_ON(!atomic_read(&dc->disk.detaching));
877 BUG_ON(atomic_read(&dc->count));
879 mutex_lock(&bch_register_lock);
881 memset(&dc->sb.set_uuid, 0, 16);
882 SET_BDEV_STATE(&dc->sb, BDEV_STATE_NONE);
884 bch_write_bdev_super(dc, &cl);
887 bcache_device_detach(&dc->disk);
888 list_move(&dc->list, &uncached_devices);
890 mutex_unlock(&bch_register_lock);
892 pr_info("Caching disabled for %s", bdevname(dc->bdev, buf));
894 /* Drop ref we took in cached_dev_detach() */
895 closure_put(&dc->disk.cl);
898 void bch_cached_dev_detach(struct cached_dev *dc)
900 lockdep_assert_held(&bch_register_lock);
902 if (atomic_read(&dc->disk.closing))
905 if (atomic_xchg(&dc->disk.detaching, 1))
909 * Block the device from being closed and freed until we're finished
912 closure_get(&dc->disk.cl);
914 bch_writeback_queue(dc);
918 int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c)
920 uint32_t rtime = cpu_to_le32(get_seconds());
921 struct uuid_entry *u;
922 char buf[BDEVNAME_SIZE];
924 bdevname(dc->bdev, buf);
926 if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16))
930 pr_err("Can't attach %s: already attached", buf);
934 if (test_bit(CACHE_SET_STOPPING, &c->flags)) {
935 pr_err("Can't attach %s: shutting down", buf);
939 if (dc->sb.block_size < c->sb.block_size) {
941 pr_err("Couldn't attach %s: block size less than set's block size",
946 u = uuid_find(c, dc->sb.uuid);
949 (BDEV_STATE(&dc->sb) == BDEV_STATE_STALE ||
950 BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) {
951 memcpy(u->uuid, invalid_uuid, 16);
952 u->invalidated = cpu_to_le32(get_seconds());
957 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
958 pr_err("Couldn't find uuid for %s in set", buf);
962 u = uuid_find_empty(c);
964 pr_err("Not caching %s, no room for UUID", buf);
969 /* Deadlocks since we're called via sysfs...
970 sysfs_remove_file(&dc->kobj, &sysfs_attach);
973 if (bch_is_zero(u->uuid, 16)) {
975 closure_init_stack(&cl);
977 memcpy(u->uuid, dc->sb.uuid, 16);
978 memcpy(u->label, dc->sb.label, SB_LABEL_SIZE);
979 u->first_reg = u->last_reg = rtime;
982 memcpy(dc->sb.set_uuid, c->sb.set_uuid, 16);
983 SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN);
985 bch_write_bdev_super(dc, &cl);
992 bcache_device_attach(&dc->disk, c, u - c->uuids);
993 list_move(&dc->list, &c->cached_devs);
994 calc_cached_dev_sectors(c);
998 * dc->c must be set before dc->count != 0 - paired with the mb in
1001 atomic_set(&dc->count, 1);
1003 if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) {
1004 bch_sectors_dirty_init(dc);
1005 atomic_set(&dc->has_dirty, 1);
1006 atomic_inc(&dc->count);
1007 bch_writeback_queue(dc);
1010 bch_cached_dev_run(dc);
1011 bcache_device_link(&dc->disk, c, "bdev");
1013 pr_info("Caching %s as %s on set %pU",
1014 bdevname(dc->bdev, buf), dc->disk.disk->disk_name,
1015 dc->disk.c->sb.set_uuid);
1019 void bch_cached_dev_release(struct kobject *kobj)
1021 struct cached_dev *dc = container_of(kobj, struct cached_dev,
1024 module_put(THIS_MODULE);
1027 static void cached_dev_free(struct closure *cl)
1029 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1031 cancel_delayed_work_sync(&dc->writeback_rate_update);
1033 mutex_lock(&bch_register_lock);
1035 if (atomic_read(&dc->running))
1036 bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
1037 bcache_device_free(&dc->disk);
1038 list_del(&dc->list);
1040 mutex_unlock(&bch_register_lock);
1042 if (!IS_ERR_OR_NULL(dc->bdev)) {
1043 if (dc->bdev->bd_disk)
1044 blk_sync_queue(bdev_get_queue(dc->bdev));
1046 blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1049 wake_up(&unregister_wait);
1051 kobject_put(&dc->disk.kobj);
1054 static void cached_dev_flush(struct closure *cl)
1056 struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl);
1057 struct bcache_device *d = &dc->disk;
1059 mutex_lock(&bch_register_lock);
1063 bcache_device_unlink(d);
1065 mutex_unlock(&bch_register_lock);
1067 bch_cache_accounting_destroy(&dc->accounting);
1068 kobject_del(&d->kobj);
1070 continue_at(cl, cached_dev_free, system_wq);
1073 static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
1077 struct request_queue *q = bdev_get_queue(dc->bdev);
1079 __module_get(THIS_MODULE);
1080 INIT_LIST_HEAD(&dc->list);
1081 closure_init(&dc->disk.cl, NULL);
1082 set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
1083 kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
1084 INIT_WORK(&dc->detach, cached_dev_detach_finish);
1085 closure_init_unlocked(&dc->sb_write);
1086 INIT_LIST_HEAD(&dc->io_lru);
1087 spin_lock_init(&dc->io_lock);
1088 bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
1090 dc->sequential_merge = true;
1091 dc->sequential_cutoff = 4 << 20;
1093 for (io = dc->io; io < dc->io + RECENT_IO; io++) {
1094 list_add(&io->lru, &dc->io_lru);
1095 hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
1098 ret = bcache_device_init(&dc->disk, block_size,
1099 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1103 set_capacity(dc->disk.disk,
1104 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
1106 dc->disk.disk->queue->backing_dev_info.ra_pages =
1107 max(dc->disk.disk->queue->backing_dev_info.ra_pages,
1108 q->backing_dev_info.ra_pages);
1110 bch_cached_dev_request_init(dc);
1111 bch_cached_dev_writeback_init(dc);
1115 /* Cached device - bcache superblock */
1117 static void register_bdev(struct cache_sb *sb, struct page *sb_page,
1118 struct block_device *bdev,
1119 struct cached_dev *dc)
1121 char name[BDEVNAME_SIZE];
1122 const char *err = "cannot allocate memory";
1123 struct cache_set *c;
1125 memcpy(&dc->sb, sb, sizeof(struct cache_sb));
1127 dc->bdev->bd_holder = dc;
1129 bio_init(&dc->sb_bio);
1130 dc->sb_bio.bi_max_vecs = 1;
1131 dc->sb_bio.bi_io_vec = dc->sb_bio.bi_inline_vecs;
1132 dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
1135 if (cached_dev_init(dc, sb->block_size << 9))
1138 err = "error creating kobject";
1139 if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
1142 if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
1145 pr_info("registered backing device %s", bdevname(bdev, name));
1147 list_add(&dc->list, &uncached_devices);
1148 list_for_each_entry(c, &bch_cache_sets, list)
1149 bch_cached_dev_attach(dc, c);
1151 if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE ||
1152 BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
1153 bch_cached_dev_run(dc);
1157 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1158 bcache_device_stop(&dc->disk);
1161 /* Flash only volumes */
1163 void bch_flash_dev_release(struct kobject *kobj)
1165 struct bcache_device *d = container_of(kobj, struct bcache_device,
1170 static void flash_dev_free(struct closure *cl)
1172 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1173 bcache_device_free(d);
1174 kobject_put(&d->kobj);
1177 static void flash_dev_flush(struct closure *cl)
1179 struct bcache_device *d = container_of(cl, struct bcache_device, cl);
1181 bcache_device_unlink(d);
1182 kobject_del(&d->kobj);
1183 continue_at(cl, flash_dev_free, system_wq);
1186 static int flash_dev_run(struct cache_set *c, struct uuid_entry *u)
1188 struct bcache_device *d = kzalloc(sizeof(struct bcache_device),
1193 closure_init(&d->cl, NULL);
1194 set_closure_fn(&d->cl, flash_dev_flush, system_wq);
1196 kobject_init(&d->kobj, &bch_flash_dev_ktype);
1198 if (bcache_device_init(d, block_bytes(c), u->sectors))
1201 bcache_device_attach(d, c, u - c->uuids);
1202 bch_flash_dev_request_init(d);
1205 if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache"))
1208 bcache_device_link(d, c, "volume");
1212 kobject_put(&d->kobj);
1216 static int flash_devs_run(struct cache_set *c)
1219 struct uuid_entry *u;
1222 u < c->uuids + c->nr_uuids && !ret;
1224 if (UUID_FLASH_ONLY(u))
1225 ret = flash_dev_run(c, u);
1230 int bch_flash_dev_create(struct cache_set *c, uint64_t size)
1232 struct uuid_entry *u;
1234 if (test_bit(CACHE_SET_STOPPING, &c->flags))
1237 u = uuid_find_empty(c);
1239 pr_err("Can't create volume, no room for UUID");
1243 get_random_bytes(u->uuid, 16);
1244 memset(u->label, 0, 32);
1245 u->first_reg = u->last_reg = cpu_to_le32(get_seconds());
1247 SET_UUID_FLASH_ONLY(u, 1);
1248 u->sectors = size >> 9;
1252 return flash_dev_run(c, u);
1258 bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...)
1262 if (c->on_error != ON_ERROR_PANIC &&
1263 test_bit(CACHE_SET_STOPPING, &c->flags))
1266 /* XXX: we can be called from atomic context
1267 acquire_console_sem();
1270 printk(KERN_ERR "bcache: error on %pU: ", c->sb.set_uuid);
1272 va_start(args, fmt);
1276 printk(", disabling caching\n");
1278 if (c->on_error == ON_ERROR_PANIC)
1279 panic("panic forced after error\n");
1281 bch_cache_set_unregister(c);
1285 void bch_cache_set_release(struct kobject *kobj)
1287 struct cache_set *c = container_of(kobj, struct cache_set, kobj);
1289 module_put(THIS_MODULE);
1292 static void cache_set_free(struct closure *cl)
1294 struct cache_set *c = container_of(cl, struct cache_set, cl);
1298 if (!IS_ERR_OR_NULL(c->debug))
1299 debugfs_remove(c->debug);
1301 bch_open_buckets_free(c);
1302 bch_btree_cache_free(c);
1303 bch_journal_free(c);
1305 for_each_cache(ca, c, i)
1307 kobject_put(&ca->kobj);
1309 free_pages((unsigned long) c->uuids, ilog2(bucket_pages(c)));
1310 free_pages((unsigned long) c->sort, ilog2(bucket_pages(c)));
1313 bioset_free(c->bio_split);
1315 mempool_destroy(c->fill_iter);
1317 mempool_destroy(c->bio_meta);
1319 mempool_destroy(c->search);
1322 mutex_lock(&bch_register_lock);
1324 mutex_unlock(&bch_register_lock);
1326 pr_info("Cache set %pU unregistered", c->sb.set_uuid);
1327 wake_up(&unregister_wait);
1329 closure_debug_destroy(&c->cl);
1330 kobject_put(&c->kobj);
1333 static void cache_set_flush(struct closure *cl)
1335 struct cache_set *c = container_of(cl, struct cache_set, caching);
1340 bch_cache_accounting_destroy(&c->accounting);
1342 kobject_put(&c->internal);
1343 kobject_del(&c->kobj);
1346 kthread_stop(c->gc_thread);
1348 if (!IS_ERR_OR_NULL(c->root))
1349 list_add(&c->root->list, &c->btree_cache);
1351 /* Should skip this if we're unregistering because of an error */
1352 list_for_each_entry(b, &c->btree_cache, list)
1353 if (btree_node_dirty(b))
1354 bch_btree_node_write(b, NULL);
1356 for_each_cache(ca, c, i)
1357 if (ca->alloc_thread)
1358 kthread_stop(ca->alloc_thread);
1363 static void __cache_set_unregister(struct closure *cl)
1365 struct cache_set *c = container_of(cl, struct cache_set, caching);
1366 struct cached_dev *dc;
1369 mutex_lock(&bch_register_lock);
1371 for (i = 0; i < c->nr_uuids; i++)
1372 if (c->devices[i]) {
1373 if (!UUID_FLASH_ONLY(&c->uuids[i]) &&
1374 test_bit(CACHE_SET_UNREGISTERING, &c->flags)) {
1375 dc = container_of(c->devices[i],
1376 struct cached_dev, disk);
1377 bch_cached_dev_detach(dc);
1379 bcache_device_stop(c->devices[i]);
1383 mutex_unlock(&bch_register_lock);
1385 continue_at(cl, cache_set_flush, system_wq);
1388 void bch_cache_set_stop(struct cache_set *c)
1390 if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags))
1391 closure_queue(&c->caching);
1394 void bch_cache_set_unregister(struct cache_set *c)
1396 set_bit(CACHE_SET_UNREGISTERING, &c->flags);
1397 bch_cache_set_stop(c);
1400 #define alloc_bucket_pages(gfp, c) \
1401 ((void *) __get_free_pages(__GFP_ZERO|gfp, ilog2(bucket_pages(c))))
1403 struct cache_set *bch_cache_set_alloc(struct cache_sb *sb)
1406 struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL);
1410 __module_get(THIS_MODULE);
1411 closure_init(&c->cl, NULL);
1412 set_closure_fn(&c->cl, cache_set_free, system_wq);
1414 closure_init(&c->caching, &c->cl);
1415 set_closure_fn(&c->caching, __cache_set_unregister, system_wq);
1417 /* Maybe create continue_at_noreturn() and use it here? */
1418 closure_set_stopped(&c->cl);
1419 closure_put(&c->cl);
1421 kobject_init(&c->kobj, &bch_cache_set_ktype);
1422 kobject_init(&c->internal, &bch_cache_set_internal_ktype);
1424 bch_cache_accounting_init(&c->accounting, &c->cl);
1426 memcpy(c->sb.set_uuid, sb->set_uuid, 16);
1427 c->sb.block_size = sb->block_size;
1428 c->sb.bucket_size = sb->bucket_size;
1429 c->sb.nr_in_set = sb->nr_in_set;
1430 c->sb.last_mount = sb->last_mount;
1431 c->bucket_bits = ilog2(sb->bucket_size);
1432 c->block_bits = ilog2(sb->block_size);
1433 c->nr_uuids = bucket_bytes(c) / sizeof(struct uuid_entry);
1435 c->btree_pages = c->sb.bucket_size / PAGE_SECTORS;
1436 if (c->btree_pages > BTREE_MAX_PAGES)
1437 c->btree_pages = max_t(int, c->btree_pages / 4,
1440 c->sort_crit_factor = int_sqrt(c->btree_pages);
1442 closure_init_unlocked(&c->sb_write);
1443 mutex_init(&c->bucket_lock);
1444 init_waitqueue_head(&c->try_wait);
1445 init_waitqueue_head(&c->bucket_wait);
1446 closure_init_unlocked(&c->uuid_write);
1447 spin_lock_init(&c->sort_time_lock);
1448 mutex_init(&c->sort_lock);
1449 spin_lock_init(&c->btree_read_time_lock);
1451 bch_moving_init_cache_set(c);
1453 INIT_LIST_HEAD(&c->list);
1454 INIT_LIST_HEAD(&c->cached_devs);
1455 INIT_LIST_HEAD(&c->btree_cache);
1456 INIT_LIST_HEAD(&c->btree_cache_freeable);
1457 INIT_LIST_HEAD(&c->btree_cache_freed);
1458 INIT_LIST_HEAD(&c->data_buckets);
1460 c->search = mempool_create_slab_pool(32, bch_search_cache);
1464 iter_size = (sb->bucket_size / sb->block_size + 1) *
1465 sizeof(struct btree_iter_set);
1467 if (!(c->devices = kzalloc(c->nr_uuids * sizeof(void *), GFP_KERNEL)) ||
1468 !(c->bio_meta = mempool_create_kmalloc_pool(2,
1469 sizeof(struct bbio) + sizeof(struct bio_vec) *
1470 bucket_pages(c))) ||
1471 !(c->fill_iter = mempool_create_kmalloc_pool(1, iter_size)) ||
1472 !(c->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
1473 !(c->sort = alloc_bucket_pages(GFP_KERNEL, c)) ||
1474 !(c->uuids = alloc_bucket_pages(GFP_KERNEL, c)) ||
1475 bch_journal_alloc(c) ||
1476 bch_btree_cache_alloc(c) ||
1477 bch_open_buckets_alloc(c))
1480 c->congested_read_threshold_us = 2000;
1481 c->congested_write_threshold_us = 20000;
1482 c->error_limit = 8 << IO_ERROR_SHIFT;
1486 bch_cache_set_unregister(c);
1490 static void run_cache_set(struct cache_set *c)
1492 const char *err = "cannot allocate memory";
1493 struct cached_dev *dc, *t;
1498 bch_btree_op_init_stack(&op);
1501 for_each_cache(ca, c, i)
1502 c->nbuckets += ca->sb.nbuckets;
1504 if (CACHE_SYNC(&c->sb)) {
1509 err = "cannot allocate memory for journal";
1510 if (bch_journal_read(c, &journal, &op))
1513 pr_debug("btree_journal_read() done");
1515 err = "no journal entries found";
1516 if (list_empty(&journal))
1519 j = &list_entry(journal.prev, struct journal_replay, list)->j;
1521 err = "IO error reading priorities";
1522 for_each_cache(ca, c, i)
1523 prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev]);
1526 * If prio_read() fails it'll call cache_set_error and we'll
1527 * tear everything down right away, but if we perhaps checked
1528 * sooner we could avoid journal replay.
1533 err = "bad btree root";
1534 if (__bch_ptr_invalid(c, j->btree_level + 1, k))
1537 err = "error reading btree root";
1538 c->root = bch_btree_node_get(c, k, j->btree_level, true);
1539 if (IS_ERR_OR_NULL(c->root))
1542 list_del_init(&c->root->list);
1543 rw_unlock(true, c->root);
1545 err = uuid_read(c, j, &op.cl);
1549 err = "error in recovery";
1550 if (bch_btree_check(c, &op))
1553 bch_journal_mark(c, &journal);
1554 bch_btree_gc_finish(c);
1555 pr_debug("btree_check() done");
1558 * bcache_journal_next() can't happen sooner, or
1559 * btree_gc_finish() will give spurious errors about last_gc >
1560 * gc_gen - this is a hack but oh well.
1562 bch_journal_next(&c->journal);
1564 err = "error starting allocator thread";
1565 for_each_cache(ca, c, i)
1566 if (bch_cache_allocator_start(ca))
1570 * First place it's safe to allocate: btree_check() and
1571 * btree_gc_finish() have to run before we have buckets to
1572 * allocate, and bch_bucket_alloc_set() might cause a journal
1573 * entry to be written so bcache_journal_next() has to be called
1576 * If the uuids were in the old format we have to rewrite them
1577 * before the next journal entry is written:
1579 if (j->version < BCACHE_JSET_VERSION_UUID)
1582 bch_journal_replay(c, &journal, &op);
1584 pr_notice("invalidating existing data");
1586 for_each_cache(ca, c, i) {
1589 ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7,
1590 2, SB_JOURNAL_BUCKETS);
1592 for (j = 0; j < ca->sb.keys; j++)
1593 ca->sb.d[j] = ca->sb.first_bucket + j;
1596 bch_btree_gc_finish(c);
1598 err = "error starting allocator thread";
1599 for_each_cache(ca, c, i)
1600 if (bch_cache_allocator_start(ca))
1603 mutex_lock(&c->bucket_lock);
1604 for_each_cache(ca, c, i)
1606 mutex_unlock(&c->bucket_lock);
1608 err = "cannot allocate new UUID bucket";
1609 if (__uuid_write(c))
1612 err = "cannot allocate new btree root";
1613 c->root = bch_btree_node_alloc(c, 0);
1614 if (IS_ERR_OR_NULL(c->root))
1617 bkey_copy_key(&c->root->key, &MAX_KEY);
1618 bch_btree_node_write(c->root, &op.cl);
1620 bch_btree_set_root(c->root);
1621 rw_unlock(true, c->root);
1624 * We don't want to write the first journal entry until
1625 * everything is set up - fortunately journal entries won't be
1626 * written until the SET_CACHE_SYNC() here:
1628 SET_CACHE_SYNC(&c->sb, true);
1630 bch_journal_next(&c->journal);
1631 bch_journal_meta(c, &op.cl);
1634 err = "error starting gc thread";
1635 if (bch_gc_thread_start(c))
1638 closure_sync(&op.cl);
1639 c->sb.last_mount = get_seconds();
1640 bcache_write_super(c);
1642 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1643 bch_cached_dev_attach(dc, c);
1649 closure_sync(&op.cl);
1650 /* XXX: test this, it's broken */
1651 bch_cache_set_error(c, err);
1654 static bool can_attach_cache(struct cache *ca, struct cache_set *c)
1656 return ca->sb.block_size == c->sb.block_size &&
1657 ca->sb.bucket_size == c->sb.block_size &&
1658 ca->sb.nr_in_set == c->sb.nr_in_set;
1661 static const char *register_cache_set(struct cache *ca)
1664 const char *err = "cannot allocate memory";
1665 struct cache_set *c;
1667 list_for_each_entry(c, &bch_cache_sets, list)
1668 if (!memcmp(c->sb.set_uuid, ca->sb.set_uuid, 16)) {
1669 if (c->cache[ca->sb.nr_this_dev])
1670 return "duplicate cache set member";
1672 if (!can_attach_cache(ca, c))
1673 return "cache sb does not match set";
1675 if (!CACHE_SYNC(&ca->sb))
1676 SET_CACHE_SYNC(&c->sb, false);
1681 c = bch_cache_set_alloc(&ca->sb);
1685 err = "error creating kobject";
1686 if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->sb.set_uuid) ||
1687 kobject_add(&c->internal, &c->kobj, "internal"))
1690 if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj))
1693 bch_debug_init_cache_set(c);
1695 list_add(&c->list, &bch_cache_sets);
1697 sprintf(buf, "cache%i", ca->sb.nr_this_dev);
1698 if (sysfs_create_link(&ca->kobj, &c->kobj, "set") ||
1699 sysfs_create_link(&c->kobj, &ca->kobj, buf))
1702 if (ca->sb.seq > c->sb.seq) {
1703 c->sb.version = ca->sb.version;
1704 memcpy(c->sb.set_uuid, ca->sb.set_uuid, 16);
1705 c->sb.flags = ca->sb.flags;
1706 c->sb.seq = ca->sb.seq;
1707 pr_debug("set version = %llu", c->sb.version);
1711 ca->set->cache[ca->sb.nr_this_dev] = ca;
1712 c->cache_by_alloc[c->caches_loaded++] = ca;
1714 if (c->caches_loaded == c->sb.nr_in_set)
1719 bch_cache_set_unregister(c);
1725 void bch_cache_release(struct kobject *kobj)
1727 struct cache *ca = container_of(kobj, struct cache, kobj);
1730 ca->set->cache[ca->sb.nr_this_dev] = NULL;
1732 bio_split_pool_free(&ca->bio_split_hook);
1734 free_pages((unsigned long) ca->disk_buckets, ilog2(bucket_pages(ca)));
1735 kfree(ca->prio_buckets);
1738 free_heap(&ca->heap);
1739 free_fifo(&ca->unused);
1740 free_fifo(&ca->free_inc);
1741 free_fifo(&ca->free);
1743 if (ca->sb_bio.bi_inline_vecs[0].bv_page)
1744 put_page(ca->sb_bio.bi_io_vec[0].bv_page);
1746 if (!IS_ERR_OR_NULL(ca->bdev)) {
1747 blk_sync_queue(bdev_get_queue(ca->bdev));
1748 blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1752 module_put(THIS_MODULE);
1755 static int cache_alloc(struct cache_sb *sb, struct cache *ca)
1760 __module_get(THIS_MODULE);
1761 kobject_init(&ca->kobj, &bch_cache_ktype);
1763 bio_init(&ca->journal.bio);
1764 ca->journal.bio.bi_max_vecs = 8;
1765 ca->journal.bio.bi_io_vec = ca->journal.bio.bi_inline_vecs;
1767 free = roundup_pow_of_two(ca->sb.nbuckets) >> 9;
1768 free = max_t(size_t, free, (prio_buckets(ca) + 8) * 2);
1770 if (!init_fifo(&ca->free, free, GFP_KERNEL) ||
1771 !init_fifo(&ca->free_inc, free << 2, GFP_KERNEL) ||
1772 !init_fifo(&ca->unused, free << 2, GFP_KERNEL) ||
1773 !init_heap(&ca->heap, free << 3, GFP_KERNEL) ||
1774 !(ca->buckets = vzalloc(sizeof(struct bucket) *
1775 ca->sb.nbuckets)) ||
1776 !(ca->prio_buckets = kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
1778 !(ca->disk_buckets = alloc_bucket_pages(GFP_KERNEL, ca)) ||
1779 bio_split_pool_init(&ca->bio_split_hook))
1782 ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
1784 for_each_bucket(b, ca)
1785 atomic_set(&b->pin, 0);
1787 if (bch_cache_allocator_init(ca))
1792 kobject_put(&ca->kobj);
1796 static void register_cache(struct cache_sb *sb, struct page *sb_page,
1797 struct block_device *bdev, struct cache *ca)
1799 char name[BDEVNAME_SIZE];
1800 const char *err = "cannot allocate memory";
1802 memcpy(&ca->sb, sb, sizeof(struct cache_sb));
1804 ca->bdev->bd_holder = ca;
1806 bio_init(&ca->sb_bio);
1807 ca->sb_bio.bi_max_vecs = 1;
1808 ca->sb_bio.bi_io_vec = ca->sb_bio.bi_inline_vecs;
1809 ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
1812 if (blk_queue_discard(bdev_get_queue(ca->bdev)))
1813 ca->discard = CACHE_DISCARD(&ca->sb);
1815 if (cache_alloc(sb, ca) != 0)
1818 err = "error creating kobject";
1819 if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache"))
1822 err = register_cache_set(ca);
1826 pr_info("registered cache device %s", bdevname(bdev, name));
1829 pr_notice("error opening %s: %s", bdevname(bdev, name), err);
1830 kobject_put(&ca->kobj);
1833 /* Global interfaces/init */
1835 static ssize_t register_bcache(struct kobject *, struct kobj_attribute *,
1836 const char *, size_t);
1838 kobj_attribute_write(register, register_bcache);
1839 kobj_attribute_write(register_quiet, register_bcache);
1841 static bool bch_is_open_backing(struct block_device *bdev) {
1842 struct cache_set *c, *tc;
1843 struct cached_dev *dc, *t;
1845 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1846 list_for_each_entry_safe(dc, t, &c->cached_devs, list)
1847 if (dc->bdev == bdev)
1849 list_for_each_entry_safe(dc, t, &uncached_devices, list)
1850 if (dc->bdev == bdev)
1855 static bool bch_is_open_cache(struct block_device *bdev) {
1856 struct cache_set *c, *tc;
1860 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1861 for_each_cache(ca, c, i)
1862 if (ca->bdev == bdev)
1867 static bool bch_is_open(struct block_device *bdev) {
1868 return bch_is_open_cache(bdev) || bch_is_open_backing(bdev);
1871 static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
1872 const char *buffer, size_t size)
1875 const char *err = "cannot allocate memory";
1877 struct cache_sb *sb = NULL;
1878 struct block_device *bdev = NULL;
1879 struct page *sb_page = NULL;
1881 if (!try_module_get(THIS_MODULE))
1884 mutex_lock(&bch_register_lock);
1886 if (!(path = kstrndup(buffer, size, GFP_KERNEL)) ||
1887 !(sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL)))
1890 err = "failed to open device";
1891 bdev = blkdev_get_by_path(strim(path),
1892 FMODE_READ|FMODE_WRITE|FMODE_EXCL,
1895 if (bdev == ERR_PTR(-EBUSY)) {
1896 bdev = lookup_bdev(strim(path));
1897 if (!IS_ERR(bdev) && bch_is_open(bdev))
1898 err = "device already registered";
1900 err = "device busy";
1905 err = "failed to set blocksize";
1906 if (set_blocksize(bdev, 4096))
1909 err = read_super(sb, bdev, &sb_page);
1913 if (SB_IS_BDEV(sb)) {
1914 struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
1918 register_bdev(sb, sb_page, bdev, dc);
1920 struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
1924 register_cache(sb, sb_page, bdev, ca);
1931 mutex_unlock(&bch_register_lock);
1932 module_put(THIS_MODULE);
1936 blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
1938 if (attr != &ksysfs_register_quiet)
1939 pr_info("error opening %s: %s", path, err);
1944 static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
1946 if (code == SYS_DOWN ||
1948 code == SYS_POWER_OFF) {
1950 unsigned long start = jiffies;
1951 bool stopped = false;
1953 struct cache_set *c, *tc;
1954 struct cached_dev *dc, *tdc;
1956 mutex_lock(&bch_register_lock);
1958 if (list_empty(&bch_cache_sets) &&
1959 list_empty(&uncached_devices))
1962 pr_info("Stopping all devices:");
1964 list_for_each_entry_safe(c, tc, &bch_cache_sets, list)
1965 bch_cache_set_stop(c);
1967 list_for_each_entry_safe(dc, tdc, &uncached_devices, list)
1968 bcache_device_stop(&dc->disk);
1970 /* What's a condition variable? */
1972 long timeout = start + 2 * HZ - jiffies;
1974 stopped = list_empty(&bch_cache_sets) &&
1975 list_empty(&uncached_devices);
1977 if (timeout < 0 || stopped)
1980 prepare_to_wait(&unregister_wait, &wait,
1981 TASK_UNINTERRUPTIBLE);
1983 mutex_unlock(&bch_register_lock);
1984 schedule_timeout(timeout);
1985 mutex_lock(&bch_register_lock);
1988 finish_wait(&unregister_wait, &wait);
1991 pr_info("All devices stopped");
1993 pr_notice("Timeout waiting for devices to be closed");
1995 mutex_unlock(&bch_register_lock);
2001 static struct notifier_block reboot = {
2002 .notifier_call = bcache_reboot,
2003 .priority = INT_MAX, /* before any real devices */
2006 static void bcache_exit(void)
2009 bch_writeback_exit();
2013 kobject_put(bcache_kobj);
2015 destroy_workqueue(bcache_wq);
2016 unregister_blkdev(bcache_major, "bcache");
2017 unregister_reboot_notifier(&reboot);
2020 static int __init bcache_init(void)
2022 static const struct attribute *files[] = {
2023 &ksysfs_register.attr,
2024 &ksysfs_register_quiet.attr,
2028 mutex_init(&bch_register_lock);
2029 init_waitqueue_head(&unregister_wait);
2030 register_reboot_notifier(&reboot);
2031 closure_debug_init();
2033 bcache_major = register_blkdev(0, "bcache");
2034 if (bcache_major < 0)
2035 return bcache_major;
2037 if (!(bcache_wq = create_workqueue("bcache")) ||
2038 !(bcache_kobj = kobject_create_and_add("bcache", fs_kobj)) ||
2039 sysfs_create_files(bcache_kobj, files) ||
2041 bch_request_init() ||
2042 bch_writeback_init() ||
2043 bch_debug_init(bcache_kobj))
2052 module_exit(bcache_exit);
2053 module_init(bcache_init);