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