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2937 lines
72 KiB
2937 lines
72 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* bcache setup/teardown code, and some metadata io - read a superblock and |
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* figure out what to do with it. |
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* |
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* Copyright 2010, 2011 Kent Overstreet <[email protected]> |
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* Copyright 2012 Google, Inc. |
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*/ |
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|
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#include "bcache.h" |
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#include "btree.h" |
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#include "debug.h" |
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#include "extents.h" |
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#include "request.h" |
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#include "writeback.h" |
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#include "features.h" |
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|
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#include <linux/blkdev.h> |
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#include <linux/pagemap.h> |
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#include <linux/debugfs.h> |
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#include <linux/genhd.h> |
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#include <linux/idr.h> |
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#include <linux/kthread.h> |
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#include <linux/workqueue.h> |
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#include <linux/module.h> |
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#include <linux/random.h> |
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#include <linux/reboot.h> |
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#include <linux/sysfs.h> |
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|
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unsigned int bch_cutoff_writeback; |
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unsigned int bch_cutoff_writeback_sync; |
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|
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static const char bcache_magic[] = { |
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0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca, |
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0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81 |
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}; |
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|
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static const char invalid_uuid[] = { |
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0xa0, 0x3e, 0xf8, 0xed, 0x3e, 0xe1, 0xb8, 0x78, |
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0xc8, 0x50, 0xfc, 0x5e, 0xcb, 0x16, 0xcd, 0x99 |
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}; |
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|
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static struct kobject *bcache_kobj; |
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struct mutex bch_register_lock; |
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bool bcache_is_reboot; |
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LIST_HEAD(bch_cache_sets); |
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static LIST_HEAD(uncached_devices); |
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|
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static int bcache_major; |
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static DEFINE_IDA(bcache_device_idx); |
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static wait_queue_head_t unregister_wait; |
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struct workqueue_struct *bcache_wq; |
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struct workqueue_struct *bch_flush_wq; |
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struct workqueue_struct *bch_journal_wq; |
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|
|
|
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#define BTREE_MAX_PAGES (256 * 1024 / PAGE_SIZE) |
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/* limitation of partitions number on single bcache device */ |
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#define BCACHE_MINORS 128 |
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/* limitation of bcache devices number on single system */ |
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#define BCACHE_DEVICE_IDX_MAX ((1U << MINORBITS)/BCACHE_MINORS) |
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|
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/* Superblock */ |
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|
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static unsigned int get_bucket_size(struct cache_sb *sb, struct cache_sb_disk *s) |
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{ |
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unsigned int bucket_size = le16_to_cpu(s->bucket_size); |
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|
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if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) { |
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if (bch_has_feature_large_bucket(sb)) { |
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unsigned int max, order; |
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|
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max = sizeof(unsigned int) * BITS_PER_BYTE - 1; |
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order = le16_to_cpu(s->bucket_size); |
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/* |
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* bcache tool will make sure the overflow won't |
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* happen, an error message here is enough. |
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*/ |
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if (order > max) |
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pr_err("Bucket size (1 << %u) overflows\n", |
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order); |
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bucket_size = 1 << order; |
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} else if (bch_has_feature_obso_large_bucket(sb)) { |
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bucket_size += |
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le16_to_cpu(s->obso_bucket_size_hi) << 16; |
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} |
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} |
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|
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return bucket_size; |
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} |
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|
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static const char *read_super_common(struct cache_sb *sb, struct block_device *bdev, |
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struct cache_sb_disk *s) |
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{ |
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const char *err; |
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unsigned int i; |
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|
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sb->first_bucket= le16_to_cpu(s->first_bucket); |
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sb->nbuckets = le64_to_cpu(s->nbuckets); |
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sb->bucket_size = get_bucket_size(sb, s); |
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|
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sb->nr_in_set = le16_to_cpu(s->nr_in_set); |
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sb->nr_this_dev = le16_to_cpu(s->nr_this_dev); |
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|
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err = "Too many journal buckets"; |
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if (sb->keys > SB_JOURNAL_BUCKETS) |
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goto err; |
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|
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err = "Too many buckets"; |
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if (sb->nbuckets > LONG_MAX) |
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goto err; |
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|
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err = "Not enough buckets"; |
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if (sb->nbuckets < 1 << 7) |
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goto err; |
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|
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err = "Bad block size (not power of 2)"; |
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if (!is_power_of_2(sb->block_size)) |
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goto err; |
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|
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err = "Bad block size (larger than page size)"; |
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if (sb->block_size > PAGE_SECTORS) |
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goto err; |
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|
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err = "Bad bucket size (not power of 2)"; |
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if (!is_power_of_2(sb->bucket_size)) |
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goto err; |
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|
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err = "Bad bucket size (smaller than page size)"; |
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if (sb->bucket_size < PAGE_SECTORS) |
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goto err; |
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|
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err = "Invalid superblock: device too small"; |
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if (get_capacity(bdev->bd_disk) < |
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sb->bucket_size * sb->nbuckets) |
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goto err; |
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|
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err = "Bad UUID"; |
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if (bch_is_zero(sb->set_uuid, 16)) |
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goto err; |
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|
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err = "Bad cache device number in set"; |
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if (!sb->nr_in_set || |
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sb->nr_in_set <= sb->nr_this_dev || |
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sb->nr_in_set > MAX_CACHES_PER_SET) |
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goto err; |
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|
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err = "Journal buckets not sequential"; |
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for (i = 0; i < sb->keys; i++) |
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if (sb->d[i] != sb->first_bucket + i) |
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goto err; |
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|
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err = "Too many journal buckets"; |
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if (sb->first_bucket + sb->keys > sb->nbuckets) |
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goto err; |
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|
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err = "Invalid superblock: first bucket comes before end of super"; |
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if (sb->first_bucket * sb->bucket_size < 16) |
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goto err; |
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|
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err = NULL; |
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err: |
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return err; |
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} |
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static const char *read_super(struct cache_sb *sb, struct block_device *bdev, |
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struct cache_sb_disk **res) |
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{ |
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const char *err; |
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struct cache_sb_disk *s; |
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struct page *page; |
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unsigned int i; |
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|
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page = read_cache_page_gfp(bdev->bd_inode->i_mapping, |
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SB_OFFSET >> PAGE_SHIFT, GFP_KERNEL); |
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if (IS_ERR(page)) |
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return "IO error"; |
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s = page_address(page) + offset_in_page(SB_OFFSET); |
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|
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sb->offset = le64_to_cpu(s->offset); |
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sb->version = le64_to_cpu(s->version); |
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|
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memcpy(sb->magic, s->magic, 16); |
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memcpy(sb->uuid, s->uuid, 16); |
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memcpy(sb->set_uuid, s->set_uuid, 16); |
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memcpy(sb->label, s->label, SB_LABEL_SIZE); |
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|
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sb->flags = le64_to_cpu(s->flags); |
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sb->seq = le64_to_cpu(s->seq); |
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sb->last_mount = le32_to_cpu(s->last_mount); |
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sb->keys = le16_to_cpu(s->keys); |
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|
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for (i = 0; i < SB_JOURNAL_BUCKETS; i++) |
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sb->d[i] = le64_to_cpu(s->d[i]); |
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|
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pr_debug("read sb version %llu, flags %llu, seq %llu, journal size %u\n", |
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sb->version, sb->flags, sb->seq, sb->keys); |
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|
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err = "Not a bcache superblock (bad offset)"; |
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if (sb->offset != SB_SECTOR) |
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goto err; |
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|
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err = "Not a bcache superblock (bad magic)"; |
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if (memcmp(sb->magic, bcache_magic, 16)) |
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goto err; |
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|
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err = "Bad checksum"; |
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if (s->csum != csum_set(s)) |
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goto err; |
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|
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err = "Bad UUID"; |
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if (bch_is_zero(sb->uuid, 16)) |
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goto err; |
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|
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sb->block_size = le16_to_cpu(s->block_size); |
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|
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err = "Superblock block size smaller than device block size"; |
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if (sb->block_size << 9 < bdev_logical_block_size(bdev)) |
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goto err; |
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|
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switch (sb->version) { |
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case BCACHE_SB_VERSION_BDEV: |
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sb->data_offset = BDEV_DATA_START_DEFAULT; |
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break; |
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case BCACHE_SB_VERSION_BDEV_WITH_OFFSET: |
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case BCACHE_SB_VERSION_BDEV_WITH_FEATURES: |
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sb->data_offset = le64_to_cpu(s->data_offset); |
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|
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err = "Bad data offset"; |
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if (sb->data_offset < BDEV_DATA_START_DEFAULT) |
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goto err; |
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|
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break; |
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case BCACHE_SB_VERSION_CDEV: |
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case BCACHE_SB_VERSION_CDEV_WITH_UUID: |
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err = read_super_common(sb, bdev, s); |
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if (err) |
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goto err; |
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break; |
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case BCACHE_SB_VERSION_CDEV_WITH_FEATURES: |
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/* |
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* Feature bits are needed in read_super_common(), |
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* convert them firstly. |
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*/ |
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sb->feature_compat = le64_to_cpu(s->feature_compat); |
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sb->feature_incompat = le64_to_cpu(s->feature_incompat); |
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sb->feature_ro_compat = le64_to_cpu(s->feature_ro_compat); |
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|
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/* Check incompatible features */ |
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err = "Unsupported compatible feature found"; |
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if (bch_has_unknown_compat_features(sb)) |
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goto err; |
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|
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err = "Unsupported read-only compatible feature found"; |
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if (bch_has_unknown_ro_compat_features(sb)) |
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goto err; |
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|
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err = "Unsupported incompatible feature found"; |
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if (bch_has_unknown_incompat_features(sb)) |
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goto err; |
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err = read_super_common(sb, bdev, s); |
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if (err) |
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goto err; |
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break; |
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default: |
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err = "Unsupported superblock version"; |
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goto err; |
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} |
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|
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sb->last_mount = (u32)ktime_get_real_seconds(); |
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*res = s; |
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return NULL; |
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err: |
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put_page(page); |
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return err; |
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} |
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static void write_bdev_super_endio(struct bio *bio) |
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{ |
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struct cached_dev *dc = bio->bi_private; |
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|
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if (bio->bi_status) |
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bch_count_backing_io_errors(dc, bio); |
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|
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closure_put(&dc->sb_write); |
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} |
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static void __write_super(struct cache_sb *sb, struct cache_sb_disk *out, |
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struct bio *bio) |
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{ |
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unsigned int i; |
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|
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bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_META; |
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bio->bi_iter.bi_sector = SB_SECTOR; |
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__bio_add_page(bio, virt_to_page(out), SB_SIZE, |
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offset_in_page(out)); |
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|
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out->offset = cpu_to_le64(sb->offset); |
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|
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memcpy(out->uuid, sb->uuid, 16); |
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memcpy(out->set_uuid, sb->set_uuid, 16); |
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memcpy(out->label, sb->label, SB_LABEL_SIZE); |
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|
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out->flags = cpu_to_le64(sb->flags); |
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out->seq = cpu_to_le64(sb->seq); |
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|
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out->last_mount = cpu_to_le32(sb->last_mount); |
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out->first_bucket = cpu_to_le16(sb->first_bucket); |
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out->keys = cpu_to_le16(sb->keys); |
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|
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for (i = 0; i < sb->keys; i++) |
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out->d[i] = cpu_to_le64(sb->d[i]); |
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|
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if (sb->version >= BCACHE_SB_VERSION_CDEV_WITH_FEATURES) { |
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out->feature_compat = cpu_to_le64(sb->feature_compat); |
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out->feature_incompat = cpu_to_le64(sb->feature_incompat); |
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out->feature_ro_compat = cpu_to_le64(sb->feature_ro_compat); |
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} |
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|
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out->version = cpu_to_le64(sb->version); |
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out->csum = csum_set(out); |
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|
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pr_debug("ver %llu, flags %llu, seq %llu\n", |
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sb->version, sb->flags, sb->seq); |
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|
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submit_bio(bio); |
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} |
|
|
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static void bch_write_bdev_super_unlock(struct closure *cl) |
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{ |
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struct cached_dev *dc = container_of(cl, struct cached_dev, sb_write); |
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|
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up(&dc->sb_write_mutex); |
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} |
|
|
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void bch_write_bdev_super(struct cached_dev *dc, struct closure *parent) |
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{ |
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struct closure *cl = &dc->sb_write; |
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struct bio *bio = &dc->sb_bio; |
|
|
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down(&dc->sb_write_mutex); |
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closure_init(cl, parent); |
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|
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bio_init(bio, dc->sb_bv, 1); |
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bio_set_dev(bio, dc->bdev); |
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bio->bi_end_io = write_bdev_super_endio; |
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bio->bi_private = dc; |
|
|
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closure_get(cl); |
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/* I/O request sent to backing device */ |
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__write_super(&dc->sb, dc->sb_disk, bio); |
|
|
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closure_return_with_destructor(cl, bch_write_bdev_super_unlock); |
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} |
|
|
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static void write_super_endio(struct bio *bio) |
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{ |
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struct cache *ca = bio->bi_private; |
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|
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/* is_read = 0 */ |
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bch_count_io_errors(ca, bio->bi_status, 0, |
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"writing superblock"); |
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closure_put(&ca->set->sb_write); |
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} |
|
|
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static void bcache_write_super_unlock(struct closure *cl) |
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{ |
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struct cache_set *c = container_of(cl, struct cache_set, sb_write); |
|
|
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up(&c->sb_write_mutex); |
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} |
|
|
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void bcache_write_super(struct cache_set *c) |
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{ |
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struct closure *cl = &c->sb_write; |
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struct cache *ca = c->cache; |
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struct bio *bio = &ca->sb_bio; |
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unsigned int version = BCACHE_SB_VERSION_CDEV_WITH_UUID; |
|
|
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down(&c->sb_write_mutex); |
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closure_init(cl, &c->cl); |
|
|
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ca->sb.seq++; |
|
|
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if (ca->sb.version < version) |
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ca->sb.version = version; |
|
|
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bio_init(bio, ca->sb_bv, 1); |
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bio_set_dev(bio, ca->bdev); |
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bio->bi_end_io = write_super_endio; |
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bio->bi_private = ca; |
|
|
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closure_get(cl); |
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__write_super(&ca->sb, ca->sb_disk, bio); |
|
|
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closure_return_with_destructor(cl, bcache_write_super_unlock); |
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} |
|
|
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/* UUID io */ |
|
|
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static void uuid_endio(struct bio *bio) |
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{ |
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struct closure *cl = bio->bi_private; |
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struct cache_set *c = container_of(cl, struct cache_set, uuid_write); |
|
|
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cache_set_err_on(bio->bi_status, c, "accessing uuids"); |
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bch_bbio_free(bio, c); |
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closure_put(cl); |
|
} |
|
|
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static void uuid_io_unlock(struct closure *cl) |
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{ |
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struct cache_set *c = container_of(cl, struct cache_set, uuid_write); |
|
|
|
up(&c->uuid_write_mutex); |
|
} |
|
|
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static void uuid_io(struct cache_set *c, int op, unsigned long op_flags, |
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struct bkey *k, struct closure *parent) |
|
{ |
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struct closure *cl = &c->uuid_write; |
|
struct uuid_entry *u; |
|
unsigned int i; |
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char buf[80]; |
|
|
|
BUG_ON(!parent); |
|
down(&c->uuid_write_mutex); |
|
closure_init(cl, parent); |
|
|
|
for (i = 0; i < KEY_PTRS(k); i++) { |
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struct bio *bio = bch_bbio_alloc(c); |
|
|
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bio->bi_opf = REQ_SYNC | REQ_META | op_flags; |
|
bio->bi_iter.bi_size = KEY_SIZE(k) << 9; |
|
|
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bio->bi_end_io = uuid_endio; |
|
bio->bi_private = cl; |
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bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags); |
|
bch_bio_map(bio, c->uuids); |
|
|
|
bch_submit_bbio(bio, c, k, i); |
|
|
|
if (op != REQ_OP_WRITE) |
|
break; |
|
} |
|
|
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bch_extent_to_text(buf, sizeof(buf), k); |
|
pr_debug("%s UUIDs at %s\n", op == REQ_OP_WRITE ? "wrote" : "read", buf); |
|
|
|
for (u = c->uuids; u < c->uuids + c->nr_uuids; u++) |
|
if (!bch_is_zero(u->uuid, 16)) |
|
pr_debug("Slot %zi: %pU: %s: 1st: %u last: %u inv: %u\n", |
|
u - c->uuids, u->uuid, u->label, |
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u->first_reg, u->last_reg, u->invalidated); |
|
|
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closure_return_with_destructor(cl, uuid_io_unlock); |
|
} |
|
|
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static char *uuid_read(struct cache_set *c, struct jset *j, struct closure *cl) |
|
{ |
|
struct bkey *k = &j->uuid_bucket; |
|
|
|
if (__bch_btree_ptr_invalid(c, k)) |
|
return "bad uuid pointer"; |
|
|
|
bkey_copy(&c->uuid_bucket, k); |
|
uuid_io(c, REQ_OP_READ, 0, k, cl); |
|
|
|
if (j->version < BCACHE_JSET_VERSION_UUIDv1) { |
|
struct uuid_entry_v0 *u0 = (void *) c->uuids; |
|
struct uuid_entry *u1 = (void *) c->uuids; |
|
int i; |
|
|
|
closure_sync(cl); |
|
|
|
/* |
|
* Since the new uuid entry is bigger than the old, we have to |
|
* convert starting at the highest memory address and work down |
|
* in order to do it in place |
|
*/ |
|
|
|
for (i = c->nr_uuids - 1; |
|
i >= 0; |
|
--i) { |
|
memcpy(u1[i].uuid, u0[i].uuid, 16); |
|
memcpy(u1[i].label, u0[i].label, 32); |
|
|
|
u1[i].first_reg = u0[i].first_reg; |
|
u1[i].last_reg = u0[i].last_reg; |
|
u1[i].invalidated = u0[i].invalidated; |
|
|
|
u1[i].flags = 0; |
|
u1[i].sectors = 0; |
|
} |
|
} |
|
|
|
return NULL; |
|
} |
|
|
|
static int __uuid_write(struct cache_set *c) |
|
{ |
|
BKEY_PADDED(key) k; |
|
struct closure cl; |
|
struct cache *ca = c->cache; |
|
unsigned int size; |
|
|
|
closure_init_stack(&cl); |
|
lockdep_assert_held(&bch_register_lock); |
|
|
|
if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, true)) |
|
return 1; |
|
|
|
size = meta_bucket_pages(&ca->sb) * PAGE_SECTORS; |
|
SET_KEY_SIZE(&k.key, size); |
|
uuid_io(c, REQ_OP_WRITE, 0, &k.key, &cl); |
|
closure_sync(&cl); |
|
|
|
/* Only one bucket used for uuid write */ |
|
atomic_long_add(ca->sb.bucket_size, &ca->meta_sectors_written); |
|
|
|
bkey_copy(&c->uuid_bucket, &k.key); |
|
bkey_put(c, &k.key); |
|
return 0; |
|
} |
|
|
|
int bch_uuid_write(struct cache_set *c) |
|
{ |
|
int ret = __uuid_write(c); |
|
|
|
if (!ret) |
|
bch_journal_meta(c, NULL); |
|
|
|
return ret; |
|
} |
|
|
|
static struct uuid_entry *uuid_find(struct cache_set *c, const char *uuid) |
|
{ |
|
struct uuid_entry *u; |
|
|
|
for (u = c->uuids; |
|
u < c->uuids + c->nr_uuids; u++) |
|
if (!memcmp(u->uuid, uuid, 16)) |
|
return u; |
|
|
|
return NULL; |
|
} |
|
|
|
static struct uuid_entry *uuid_find_empty(struct cache_set *c) |
|
{ |
|
static const char zero_uuid[16] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"; |
|
|
|
return uuid_find(c, zero_uuid); |
|
} |
|
|
|
/* |
|
* Bucket priorities/gens: |
|
* |
|
* For each bucket, we store on disk its |
|
* 8 bit gen |
|
* 16 bit priority |
|
* |
|
* See alloc.c for an explanation of the gen. The priority is used to implement |
|
* lru (and in the future other) cache replacement policies; for most purposes |
|
* it's just an opaque integer. |
|
* |
|
* The gens and the priorities don't have a whole lot to do with each other, and |
|
* it's actually the gens that must be written out at specific times - it's no |
|
* big deal if the priorities don't get written, if we lose them we just reuse |
|
* buckets in suboptimal order. |
|
* |
|
* On disk they're stored in a packed array, and in as many buckets are required |
|
* to fit them all. The buckets we use to store them form a list; the journal |
|
* header points to the first bucket, the first bucket points to the second |
|
* bucket, et cetera. |
|
* |
|
* This code is used by the allocation code; periodically (whenever it runs out |
|
* of buckets to allocate from) the allocation code will invalidate some |
|
* buckets, but it can't use those buckets until their new gens are safely on |
|
* disk. |
|
*/ |
|
|
|
static void prio_endio(struct bio *bio) |
|
{ |
|
struct cache *ca = bio->bi_private; |
|
|
|
cache_set_err_on(bio->bi_status, ca->set, "accessing priorities"); |
|
bch_bbio_free(bio, ca->set); |
|
closure_put(&ca->prio); |
|
} |
|
|
|
static void prio_io(struct cache *ca, uint64_t bucket, int op, |
|
unsigned long op_flags) |
|
{ |
|
struct closure *cl = &ca->prio; |
|
struct bio *bio = bch_bbio_alloc(ca->set); |
|
|
|
closure_init_stack(cl); |
|
|
|
bio->bi_iter.bi_sector = bucket * ca->sb.bucket_size; |
|
bio_set_dev(bio, ca->bdev); |
|
bio->bi_iter.bi_size = meta_bucket_bytes(&ca->sb); |
|
|
|
bio->bi_end_io = prio_endio; |
|
bio->bi_private = ca; |
|
bio_set_op_attrs(bio, op, REQ_SYNC|REQ_META|op_flags); |
|
bch_bio_map(bio, ca->disk_buckets); |
|
|
|
closure_bio_submit(ca->set, bio, &ca->prio); |
|
closure_sync(cl); |
|
} |
|
|
|
int bch_prio_write(struct cache *ca, bool wait) |
|
{ |
|
int i; |
|
struct bucket *b; |
|
struct closure cl; |
|
|
|
pr_debug("free_prio=%zu, free_none=%zu, free_inc=%zu\n", |
|
fifo_used(&ca->free[RESERVE_PRIO]), |
|
fifo_used(&ca->free[RESERVE_NONE]), |
|
fifo_used(&ca->free_inc)); |
|
|
|
/* |
|
* Pre-check if there are enough free buckets. In the non-blocking |
|
* scenario it's better to fail early rather than starting to allocate |
|
* buckets and do a cleanup later in case of failure. |
|
*/ |
|
if (!wait) { |
|
size_t avail = fifo_used(&ca->free[RESERVE_PRIO]) + |
|
fifo_used(&ca->free[RESERVE_NONE]); |
|
if (prio_buckets(ca) > avail) |
|
return -ENOMEM; |
|
} |
|
|
|
closure_init_stack(&cl); |
|
|
|
lockdep_assert_held(&ca->set->bucket_lock); |
|
|
|
ca->disk_buckets->seq++; |
|
|
|
atomic_long_add(ca->sb.bucket_size * prio_buckets(ca), |
|
&ca->meta_sectors_written); |
|
|
|
for (i = prio_buckets(ca) - 1; i >= 0; --i) { |
|
long bucket; |
|
struct prio_set *p = ca->disk_buckets; |
|
struct bucket_disk *d = p->data; |
|
struct bucket_disk *end = d + prios_per_bucket(ca); |
|
|
|
for (b = ca->buckets + i * prios_per_bucket(ca); |
|
b < ca->buckets + ca->sb.nbuckets && d < end; |
|
b++, d++) { |
|
d->prio = cpu_to_le16(b->prio); |
|
d->gen = b->gen; |
|
} |
|
|
|
p->next_bucket = ca->prio_buckets[i + 1]; |
|
p->magic = pset_magic(&ca->sb); |
|
p->csum = bch_crc64(&p->magic, meta_bucket_bytes(&ca->sb) - 8); |
|
|
|
bucket = bch_bucket_alloc(ca, RESERVE_PRIO, wait); |
|
BUG_ON(bucket == -1); |
|
|
|
mutex_unlock(&ca->set->bucket_lock); |
|
prio_io(ca, bucket, REQ_OP_WRITE, 0); |
|
mutex_lock(&ca->set->bucket_lock); |
|
|
|
ca->prio_buckets[i] = bucket; |
|
atomic_dec_bug(&ca->buckets[bucket].pin); |
|
} |
|
|
|
mutex_unlock(&ca->set->bucket_lock); |
|
|
|
bch_journal_meta(ca->set, &cl); |
|
closure_sync(&cl); |
|
|
|
mutex_lock(&ca->set->bucket_lock); |
|
|
|
/* |
|
* Don't want the old priorities to get garbage collected until after we |
|
* finish writing the new ones, and they're journalled |
|
*/ |
|
for (i = 0; i < prio_buckets(ca); i++) { |
|
if (ca->prio_last_buckets[i]) |
|
__bch_bucket_free(ca, |
|
&ca->buckets[ca->prio_last_buckets[i]]); |
|
|
|
ca->prio_last_buckets[i] = ca->prio_buckets[i]; |
|
} |
|
return 0; |
|
} |
|
|
|
static int prio_read(struct cache *ca, uint64_t bucket) |
|
{ |
|
struct prio_set *p = ca->disk_buckets; |
|
struct bucket_disk *d = p->data + prios_per_bucket(ca), *end = d; |
|
struct bucket *b; |
|
unsigned int bucket_nr = 0; |
|
int ret = -EIO; |
|
|
|
for (b = ca->buckets; |
|
b < ca->buckets + ca->sb.nbuckets; |
|
b++, d++) { |
|
if (d == end) { |
|
ca->prio_buckets[bucket_nr] = bucket; |
|
ca->prio_last_buckets[bucket_nr] = bucket; |
|
bucket_nr++; |
|
|
|
prio_io(ca, bucket, REQ_OP_READ, 0); |
|
|
|
if (p->csum != |
|
bch_crc64(&p->magic, meta_bucket_bytes(&ca->sb) - 8)) { |
|
pr_warn("bad csum reading priorities\n"); |
|
goto out; |
|
} |
|
|
|
if (p->magic != pset_magic(&ca->sb)) { |
|
pr_warn("bad magic reading priorities\n"); |
|
goto out; |
|
} |
|
|
|
bucket = p->next_bucket; |
|
d = p->data; |
|
} |
|
|
|
b->prio = le16_to_cpu(d->prio); |
|
b->gen = b->last_gc = d->gen; |
|
} |
|
|
|
ret = 0; |
|
out: |
|
return ret; |
|
} |
|
|
|
/* Bcache device */ |
|
|
|
static int open_dev(struct block_device *b, fmode_t mode) |
|
{ |
|
struct bcache_device *d = b->bd_disk->private_data; |
|
|
|
if (test_bit(BCACHE_DEV_CLOSING, &d->flags)) |
|
return -ENXIO; |
|
|
|
closure_get(&d->cl); |
|
return 0; |
|
} |
|
|
|
static void release_dev(struct gendisk *b, fmode_t mode) |
|
{ |
|
struct bcache_device *d = b->private_data; |
|
|
|
closure_put(&d->cl); |
|
} |
|
|
|
static int ioctl_dev(struct block_device *b, fmode_t mode, |
|
unsigned int cmd, unsigned long arg) |
|
{ |
|
struct bcache_device *d = b->bd_disk->private_data; |
|
|
|
return d->ioctl(d, mode, cmd, arg); |
|
} |
|
|
|
static const struct block_device_operations bcache_cached_ops = { |
|
.submit_bio = cached_dev_submit_bio, |
|
.open = open_dev, |
|
.release = release_dev, |
|
.ioctl = ioctl_dev, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
static const struct block_device_operations bcache_flash_ops = { |
|
.submit_bio = flash_dev_submit_bio, |
|
.open = open_dev, |
|
.release = release_dev, |
|
.ioctl = ioctl_dev, |
|
.owner = THIS_MODULE, |
|
}; |
|
|
|
void bcache_device_stop(struct bcache_device *d) |
|
{ |
|
if (!test_and_set_bit(BCACHE_DEV_CLOSING, &d->flags)) |
|
/* |
|
* closure_fn set to |
|
* - cached device: cached_dev_flush() |
|
* - flash dev: flash_dev_flush() |
|
*/ |
|
closure_queue(&d->cl); |
|
} |
|
|
|
static void bcache_device_unlink(struct bcache_device *d) |
|
{ |
|
lockdep_assert_held(&bch_register_lock); |
|
|
|
if (d->c && !test_and_set_bit(BCACHE_DEV_UNLINK_DONE, &d->flags)) { |
|
struct cache *ca = d->c->cache; |
|
|
|
sysfs_remove_link(&d->c->kobj, d->name); |
|
sysfs_remove_link(&d->kobj, "cache"); |
|
|
|
bd_unlink_disk_holder(ca->bdev, d->disk); |
|
} |
|
} |
|
|
|
static void bcache_device_link(struct bcache_device *d, struct cache_set *c, |
|
const char *name) |
|
{ |
|
struct cache *ca = c->cache; |
|
int ret; |
|
|
|
bd_link_disk_holder(ca->bdev, d->disk); |
|
|
|
snprintf(d->name, BCACHEDEVNAME_SIZE, |
|
"%s%u", name, d->id); |
|
|
|
ret = sysfs_create_link(&d->kobj, &c->kobj, "cache"); |
|
if (ret < 0) |
|
pr_err("Couldn't create device -> cache set symlink\n"); |
|
|
|
ret = sysfs_create_link(&c->kobj, &d->kobj, d->name); |
|
if (ret < 0) |
|
pr_err("Couldn't create cache set -> device symlink\n"); |
|
|
|
clear_bit(BCACHE_DEV_UNLINK_DONE, &d->flags); |
|
} |
|
|
|
static void bcache_device_detach(struct bcache_device *d) |
|
{ |
|
lockdep_assert_held(&bch_register_lock); |
|
|
|
atomic_dec(&d->c->attached_dev_nr); |
|
|
|
if (test_bit(BCACHE_DEV_DETACHING, &d->flags)) { |
|
struct uuid_entry *u = d->c->uuids + d->id; |
|
|
|
SET_UUID_FLASH_ONLY(u, 0); |
|
memcpy(u->uuid, invalid_uuid, 16); |
|
u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); |
|
bch_uuid_write(d->c); |
|
} |
|
|
|
bcache_device_unlink(d); |
|
|
|
d->c->devices[d->id] = NULL; |
|
closure_put(&d->c->caching); |
|
d->c = NULL; |
|
} |
|
|
|
static void bcache_device_attach(struct bcache_device *d, struct cache_set *c, |
|
unsigned int id) |
|
{ |
|
d->id = id; |
|
d->c = c; |
|
c->devices[id] = d; |
|
|
|
if (id >= c->devices_max_used) |
|
c->devices_max_used = id + 1; |
|
|
|
closure_get(&c->caching); |
|
} |
|
|
|
static inline int first_minor_to_idx(int first_minor) |
|
{ |
|
return (first_minor/BCACHE_MINORS); |
|
} |
|
|
|
static inline int idx_to_first_minor(int idx) |
|
{ |
|
return (idx * BCACHE_MINORS); |
|
} |
|
|
|
static void bcache_device_free(struct bcache_device *d) |
|
{ |
|
struct gendisk *disk = d->disk; |
|
|
|
lockdep_assert_held(&bch_register_lock); |
|
|
|
if (disk) |
|
pr_info("%s stopped\n", disk->disk_name); |
|
else |
|
pr_err("bcache device (NULL gendisk) stopped\n"); |
|
|
|
if (d->c) |
|
bcache_device_detach(d); |
|
|
|
if (disk) { |
|
ida_simple_remove(&bcache_device_idx, |
|
first_minor_to_idx(disk->first_minor)); |
|
blk_cleanup_disk(disk); |
|
} |
|
|
|
bioset_exit(&d->bio_split); |
|
kvfree(d->full_dirty_stripes); |
|
kvfree(d->stripe_sectors_dirty); |
|
|
|
closure_debug_destroy(&d->cl); |
|
} |
|
|
|
static int bcache_device_init(struct bcache_device *d, unsigned int block_size, |
|
sector_t sectors, struct block_device *cached_bdev, |
|
const struct block_device_operations *ops) |
|
{ |
|
struct request_queue *q; |
|
const size_t max_stripes = min_t(size_t, INT_MAX, |
|
SIZE_MAX / sizeof(atomic_t)); |
|
uint64_t n; |
|
int idx; |
|
|
|
if (!d->stripe_size) |
|
d->stripe_size = 1 << 31; |
|
|
|
n = DIV_ROUND_UP_ULL(sectors, d->stripe_size); |
|
if (!n || n > max_stripes) { |
|
pr_err("nr_stripes too large or invalid: %llu (start sector beyond end of disk?)\n", |
|
n); |
|
return -ENOMEM; |
|
} |
|
d->nr_stripes = n; |
|
|
|
n = d->nr_stripes * sizeof(atomic_t); |
|
d->stripe_sectors_dirty = kvzalloc(n, GFP_KERNEL); |
|
if (!d->stripe_sectors_dirty) |
|
return -ENOMEM; |
|
|
|
n = BITS_TO_LONGS(d->nr_stripes) * sizeof(unsigned long); |
|
d->full_dirty_stripes = kvzalloc(n, GFP_KERNEL); |
|
if (!d->full_dirty_stripes) |
|
goto out_free_stripe_sectors_dirty; |
|
|
|
idx = ida_simple_get(&bcache_device_idx, 0, |
|
BCACHE_DEVICE_IDX_MAX, GFP_KERNEL); |
|
if (idx < 0) |
|
goto out_free_full_dirty_stripes; |
|
|
|
if (bioset_init(&d->bio_split, 4, offsetof(struct bbio, bio), |
|
BIOSET_NEED_BVECS|BIOSET_NEED_RESCUER)) |
|
goto out_ida_remove; |
|
|
|
d->disk = blk_alloc_disk(NUMA_NO_NODE); |
|
if (!d->disk) |
|
goto out_bioset_exit; |
|
|
|
set_capacity(d->disk, sectors); |
|
snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", idx); |
|
|
|
d->disk->major = bcache_major; |
|
d->disk->first_minor = idx_to_first_minor(idx); |
|
d->disk->minors = BCACHE_MINORS; |
|
d->disk->fops = ops; |
|
d->disk->private_data = d; |
|
|
|
q = d->disk->queue; |
|
q->limits.max_hw_sectors = UINT_MAX; |
|
q->limits.max_sectors = UINT_MAX; |
|
q->limits.max_segment_size = UINT_MAX; |
|
q->limits.max_segments = BIO_MAX_VECS; |
|
blk_queue_max_discard_sectors(q, UINT_MAX); |
|
q->limits.discard_granularity = 512; |
|
q->limits.io_min = block_size; |
|
q->limits.logical_block_size = block_size; |
|
q->limits.physical_block_size = block_size; |
|
|
|
if (q->limits.logical_block_size > PAGE_SIZE && cached_bdev) { |
|
/* |
|
* This should only happen with BCACHE_SB_VERSION_BDEV. |
|
* Block/page size is checked for BCACHE_SB_VERSION_CDEV. |
|
*/ |
|
pr_info("%s: sb/logical block size (%u) greater than page size (%lu) falling back to device logical block size (%u)\n", |
|
d->disk->disk_name, q->limits.logical_block_size, |
|
PAGE_SIZE, bdev_logical_block_size(cached_bdev)); |
|
|
|
/* This also adjusts physical block size/min io size if needed */ |
|
blk_queue_logical_block_size(q, bdev_logical_block_size(cached_bdev)); |
|
} |
|
|
|
blk_queue_flag_set(QUEUE_FLAG_NONROT, d->disk->queue); |
|
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, d->disk->queue); |
|
blk_queue_flag_set(QUEUE_FLAG_DISCARD, d->disk->queue); |
|
|
|
blk_queue_write_cache(q, true, true); |
|
|
|
return 0; |
|
|
|
out_bioset_exit: |
|
bioset_exit(&d->bio_split); |
|
out_ida_remove: |
|
ida_simple_remove(&bcache_device_idx, idx); |
|
out_free_full_dirty_stripes: |
|
kvfree(d->full_dirty_stripes); |
|
out_free_stripe_sectors_dirty: |
|
kvfree(d->stripe_sectors_dirty); |
|
return -ENOMEM; |
|
|
|
} |
|
|
|
/* Cached device */ |
|
|
|
static void calc_cached_dev_sectors(struct cache_set *c) |
|
{ |
|
uint64_t sectors = 0; |
|
struct cached_dev *dc; |
|
|
|
list_for_each_entry(dc, &c->cached_devs, list) |
|
sectors += bdev_sectors(dc->bdev); |
|
|
|
c->cached_dev_sectors = sectors; |
|
} |
|
|
|
#define BACKING_DEV_OFFLINE_TIMEOUT 5 |
|
static int cached_dev_status_update(void *arg) |
|
{ |
|
struct cached_dev *dc = arg; |
|
struct request_queue *q; |
|
|
|
/* |
|
* If this delayed worker is stopping outside, directly quit here. |
|
* dc->io_disable might be set via sysfs interface, so check it |
|
* here too. |
|
*/ |
|
while (!kthread_should_stop() && !dc->io_disable) { |
|
q = bdev_get_queue(dc->bdev); |
|
if (blk_queue_dying(q)) |
|
dc->offline_seconds++; |
|
else |
|
dc->offline_seconds = 0; |
|
|
|
if (dc->offline_seconds >= BACKING_DEV_OFFLINE_TIMEOUT) { |
|
pr_err("%s: device offline for %d seconds\n", |
|
dc->backing_dev_name, |
|
BACKING_DEV_OFFLINE_TIMEOUT); |
|
pr_err("%s: disable I/O request due to backing device offline\n", |
|
dc->disk.name); |
|
dc->io_disable = true; |
|
/* let others know earlier that io_disable is true */ |
|
smp_mb(); |
|
bcache_device_stop(&dc->disk); |
|
break; |
|
} |
|
schedule_timeout_interruptible(HZ); |
|
} |
|
|
|
wait_for_kthread_stop(); |
|
return 0; |
|
} |
|
|
|
|
|
int bch_cached_dev_run(struct cached_dev *dc) |
|
{ |
|
int ret = 0; |
|
struct bcache_device *d = &dc->disk; |
|
char *buf = kmemdup_nul(dc->sb.label, SB_LABEL_SIZE, GFP_KERNEL); |
|
char *env[] = { |
|
"DRIVER=bcache", |
|
kasprintf(GFP_KERNEL, "CACHED_UUID=%pU", dc->sb.uuid), |
|
kasprintf(GFP_KERNEL, "CACHED_LABEL=%s", buf ? : ""), |
|
NULL, |
|
}; |
|
|
|
if (dc->io_disable) { |
|
pr_err("I/O disabled on cached dev %s\n", |
|
dc->backing_dev_name); |
|
ret = -EIO; |
|
goto out; |
|
} |
|
|
|
if (atomic_xchg(&dc->running, 1)) { |
|
pr_info("cached dev %s is running already\n", |
|
dc->backing_dev_name); |
|
ret = -EBUSY; |
|
goto out; |
|
} |
|
|
|
if (!d->c && |
|
BDEV_STATE(&dc->sb) != BDEV_STATE_NONE) { |
|
struct closure cl; |
|
|
|
closure_init_stack(&cl); |
|
|
|
SET_BDEV_STATE(&dc->sb, BDEV_STATE_STALE); |
|
bch_write_bdev_super(dc, &cl); |
|
closure_sync(&cl); |
|
} |
|
|
|
add_disk(d->disk); |
|
bd_link_disk_holder(dc->bdev, dc->disk.disk); |
|
/* |
|
* won't show up in the uevent file, use udevadm monitor -e instead |
|
* only class / kset properties are persistent |
|
*/ |
|
kobject_uevent_env(&disk_to_dev(d->disk)->kobj, KOBJ_CHANGE, env); |
|
|
|
if (sysfs_create_link(&d->kobj, &disk_to_dev(d->disk)->kobj, "dev") || |
|
sysfs_create_link(&disk_to_dev(d->disk)->kobj, |
|
&d->kobj, "bcache")) { |
|
pr_err("Couldn't create bcache dev <-> disk sysfs symlinks\n"); |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
dc->status_update_thread = kthread_run(cached_dev_status_update, |
|
dc, "bcache_status_update"); |
|
if (IS_ERR(dc->status_update_thread)) { |
|
pr_warn("failed to create bcache_status_update kthread, continue to run without monitoring backing device status\n"); |
|
} |
|
|
|
out: |
|
kfree(env[1]); |
|
kfree(env[2]); |
|
kfree(buf); |
|
return ret; |
|
} |
|
|
|
/* |
|
* If BCACHE_DEV_RATE_DW_RUNNING is set, it means routine of the delayed |
|
* work dc->writeback_rate_update is running. Wait until the routine |
|
* quits (BCACHE_DEV_RATE_DW_RUNNING is clear), then continue to |
|
* cancel it. If BCACHE_DEV_RATE_DW_RUNNING is not clear after time_out |
|
* seconds, give up waiting here and continue to cancel it too. |
|
*/ |
|
static void cancel_writeback_rate_update_dwork(struct cached_dev *dc) |
|
{ |
|
int time_out = WRITEBACK_RATE_UPDATE_SECS_MAX * HZ; |
|
|
|
do { |
|
if (!test_bit(BCACHE_DEV_RATE_DW_RUNNING, |
|
&dc->disk.flags)) |
|
break; |
|
time_out--; |
|
schedule_timeout_interruptible(1); |
|
} while (time_out > 0); |
|
|
|
if (time_out == 0) |
|
pr_warn("give up waiting for dc->writeback_write_update to quit\n"); |
|
|
|
cancel_delayed_work_sync(&dc->writeback_rate_update); |
|
} |
|
|
|
static void cached_dev_detach_finish(struct work_struct *w) |
|
{ |
|
struct cached_dev *dc = container_of(w, struct cached_dev, detach); |
|
|
|
BUG_ON(!test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)); |
|
BUG_ON(refcount_read(&dc->count)); |
|
|
|
|
|
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)) |
|
cancel_writeback_rate_update_dwork(dc); |
|
|
|
if (!IS_ERR_OR_NULL(dc->writeback_thread)) { |
|
kthread_stop(dc->writeback_thread); |
|
dc->writeback_thread = NULL; |
|
} |
|
|
|
mutex_lock(&bch_register_lock); |
|
|
|
calc_cached_dev_sectors(dc->disk.c); |
|
bcache_device_detach(&dc->disk); |
|
list_move(&dc->list, &uncached_devices); |
|
|
|
clear_bit(BCACHE_DEV_DETACHING, &dc->disk.flags); |
|
clear_bit(BCACHE_DEV_UNLINK_DONE, &dc->disk.flags); |
|
|
|
mutex_unlock(&bch_register_lock); |
|
|
|
pr_info("Caching disabled for %s\n", dc->backing_dev_name); |
|
|
|
/* Drop ref we took in cached_dev_detach() */ |
|
closure_put(&dc->disk.cl); |
|
} |
|
|
|
void bch_cached_dev_detach(struct cached_dev *dc) |
|
{ |
|
lockdep_assert_held(&bch_register_lock); |
|
|
|
if (test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags)) |
|
return; |
|
|
|
if (test_and_set_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) |
|
return; |
|
|
|
/* |
|
* Block the device from being closed and freed until we're finished |
|
* detaching |
|
*/ |
|
closure_get(&dc->disk.cl); |
|
|
|
bch_writeback_queue(dc); |
|
|
|
cached_dev_put(dc); |
|
} |
|
|
|
int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, |
|
uint8_t *set_uuid) |
|
{ |
|
uint32_t rtime = cpu_to_le32((u32)ktime_get_real_seconds()); |
|
struct uuid_entry *u; |
|
struct cached_dev *exist_dc, *t; |
|
int ret = 0; |
|
|
|
if ((set_uuid && memcmp(set_uuid, c->set_uuid, 16)) || |
|
(!set_uuid && memcmp(dc->sb.set_uuid, c->set_uuid, 16))) |
|
return -ENOENT; |
|
|
|
if (dc->disk.c) { |
|
pr_err("Can't attach %s: already attached\n", |
|
dc->backing_dev_name); |
|
return -EINVAL; |
|
} |
|
|
|
if (test_bit(CACHE_SET_STOPPING, &c->flags)) { |
|
pr_err("Can't attach %s: shutting down\n", |
|
dc->backing_dev_name); |
|
return -EINVAL; |
|
} |
|
|
|
if (dc->sb.block_size < c->cache->sb.block_size) { |
|
/* Will die */ |
|
pr_err("Couldn't attach %s: block size less than set's block size\n", |
|
dc->backing_dev_name); |
|
return -EINVAL; |
|
} |
|
|
|
/* Check whether already attached */ |
|
list_for_each_entry_safe(exist_dc, t, &c->cached_devs, list) { |
|
if (!memcmp(dc->sb.uuid, exist_dc->sb.uuid, 16)) { |
|
pr_err("Tried to attach %s but duplicate UUID already attached\n", |
|
dc->backing_dev_name); |
|
|
|
return -EINVAL; |
|
} |
|
} |
|
|
|
u = uuid_find(c, dc->sb.uuid); |
|
|
|
if (u && |
|
(BDEV_STATE(&dc->sb) == BDEV_STATE_STALE || |
|
BDEV_STATE(&dc->sb) == BDEV_STATE_NONE)) { |
|
memcpy(u->uuid, invalid_uuid, 16); |
|
u->invalidated = cpu_to_le32((u32)ktime_get_real_seconds()); |
|
u = NULL; |
|
} |
|
|
|
if (!u) { |
|
if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) { |
|
pr_err("Couldn't find uuid for %s in set\n", |
|
dc->backing_dev_name); |
|
return -ENOENT; |
|
} |
|
|
|
u = uuid_find_empty(c); |
|
if (!u) { |
|
pr_err("Not caching %s, no room for UUID\n", |
|
dc->backing_dev_name); |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/* |
|
* Deadlocks since we're called via sysfs... |
|
* sysfs_remove_file(&dc->kobj, &sysfs_attach); |
|
*/ |
|
|
|
if (bch_is_zero(u->uuid, 16)) { |
|
struct closure cl; |
|
|
|
closure_init_stack(&cl); |
|
|
|
memcpy(u->uuid, dc->sb.uuid, 16); |
|
memcpy(u->label, dc->sb.label, SB_LABEL_SIZE); |
|
u->first_reg = u->last_reg = rtime; |
|
bch_uuid_write(c); |
|
|
|
memcpy(dc->sb.set_uuid, c->set_uuid, 16); |
|
SET_BDEV_STATE(&dc->sb, BDEV_STATE_CLEAN); |
|
|
|
bch_write_bdev_super(dc, &cl); |
|
closure_sync(&cl); |
|
} else { |
|
u->last_reg = rtime; |
|
bch_uuid_write(c); |
|
} |
|
|
|
bcache_device_attach(&dc->disk, c, u - c->uuids); |
|
list_move(&dc->list, &c->cached_devs); |
|
calc_cached_dev_sectors(c); |
|
|
|
/* |
|
* dc->c must be set before dc->count != 0 - paired with the mb in |
|
* cached_dev_get() |
|
*/ |
|
smp_wmb(); |
|
refcount_set(&dc->count, 1); |
|
|
|
/* Block writeback thread, but spawn it */ |
|
down_write(&dc->writeback_lock); |
|
if (bch_cached_dev_writeback_start(dc)) { |
|
up_write(&dc->writeback_lock); |
|
pr_err("Couldn't start writeback facilities for %s\n", |
|
dc->disk.disk->disk_name); |
|
return -ENOMEM; |
|
} |
|
|
|
if (BDEV_STATE(&dc->sb) == BDEV_STATE_DIRTY) { |
|
atomic_set(&dc->has_dirty, 1); |
|
bch_writeback_queue(dc); |
|
} |
|
|
|
bch_sectors_dirty_init(&dc->disk); |
|
|
|
ret = bch_cached_dev_run(dc); |
|
if (ret && (ret != -EBUSY)) { |
|
up_write(&dc->writeback_lock); |
|
/* |
|
* bch_register_lock is held, bcache_device_stop() is not |
|
* able to be directly called. The kthread and kworker |
|
* created previously in bch_cached_dev_writeback_start() |
|
* have to be stopped manually here. |
|
*/ |
|
kthread_stop(dc->writeback_thread); |
|
cancel_writeback_rate_update_dwork(dc); |
|
pr_err("Couldn't run cached device %s\n", |
|
dc->backing_dev_name); |
|
return ret; |
|
} |
|
|
|
bcache_device_link(&dc->disk, c, "bdev"); |
|
atomic_inc(&c->attached_dev_nr); |
|
|
|
if (bch_has_feature_obso_large_bucket(&(c->cache->sb))) { |
|
pr_err("The obsoleted large bucket layout is unsupported, set the bcache device into read-only\n"); |
|
pr_err("Please update to the latest bcache-tools to create the cache device\n"); |
|
set_disk_ro(dc->disk.disk, 1); |
|
} |
|
|
|
/* Allow the writeback thread to proceed */ |
|
up_write(&dc->writeback_lock); |
|
|
|
pr_info("Caching %s as %s on set %pU\n", |
|
dc->backing_dev_name, |
|
dc->disk.disk->disk_name, |
|
dc->disk.c->set_uuid); |
|
return 0; |
|
} |
|
|
|
/* when dc->disk.kobj released */ |
|
void bch_cached_dev_release(struct kobject *kobj) |
|
{ |
|
struct cached_dev *dc = container_of(kobj, struct cached_dev, |
|
disk.kobj); |
|
kfree(dc); |
|
module_put(THIS_MODULE); |
|
} |
|
|
|
static void cached_dev_free(struct closure *cl) |
|
{ |
|
struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl); |
|
|
|
if (test_and_clear_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)) |
|
cancel_writeback_rate_update_dwork(dc); |
|
|
|
if (!IS_ERR_OR_NULL(dc->writeback_thread)) |
|
kthread_stop(dc->writeback_thread); |
|
if (!IS_ERR_OR_NULL(dc->status_update_thread)) |
|
kthread_stop(dc->status_update_thread); |
|
|
|
mutex_lock(&bch_register_lock); |
|
|
|
if (atomic_read(&dc->running)) { |
|
bd_unlink_disk_holder(dc->bdev, dc->disk.disk); |
|
del_gendisk(dc->disk.disk); |
|
} |
|
bcache_device_free(&dc->disk); |
|
list_del(&dc->list); |
|
|
|
mutex_unlock(&bch_register_lock); |
|
|
|
if (dc->sb_disk) |
|
put_page(virt_to_page(dc->sb_disk)); |
|
|
|
if (!IS_ERR_OR_NULL(dc->bdev)) |
|
blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
|
|
|
wake_up(&unregister_wait); |
|
|
|
kobject_put(&dc->disk.kobj); |
|
} |
|
|
|
static void cached_dev_flush(struct closure *cl) |
|
{ |
|
struct cached_dev *dc = container_of(cl, struct cached_dev, disk.cl); |
|
struct bcache_device *d = &dc->disk; |
|
|
|
mutex_lock(&bch_register_lock); |
|
bcache_device_unlink(d); |
|
mutex_unlock(&bch_register_lock); |
|
|
|
bch_cache_accounting_destroy(&dc->accounting); |
|
kobject_del(&d->kobj); |
|
|
|
continue_at(cl, cached_dev_free, system_wq); |
|
} |
|
|
|
static int cached_dev_init(struct cached_dev *dc, unsigned int block_size) |
|
{ |
|
int ret; |
|
struct io *io; |
|
struct request_queue *q = bdev_get_queue(dc->bdev); |
|
|
|
__module_get(THIS_MODULE); |
|
INIT_LIST_HEAD(&dc->list); |
|
closure_init(&dc->disk.cl, NULL); |
|
set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq); |
|
kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype); |
|
INIT_WORK(&dc->detach, cached_dev_detach_finish); |
|
sema_init(&dc->sb_write_mutex, 1); |
|
INIT_LIST_HEAD(&dc->io_lru); |
|
spin_lock_init(&dc->io_lock); |
|
bch_cache_accounting_init(&dc->accounting, &dc->disk.cl); |
|
|
|
dc->sequential_cutoff = 4 << 20; |
|
|
|
for (io = dc->io; io < dc->io + RECENT_IO; io++) { |
|
list_add(&io->lru, &dc->io_lru); |
|
hlist_add_head(&io->hash, dc->io_hash + RECENT_IO); |
|
} |
|
|
|
dc->disk.stripe_size = q->limits.io_opt >> 9; |
|
|
|
if (dc->disk.stripe_size) |
|
dc->partial_stripes_expensive = |
|
q->limits.raid_partial_stripes_expensive; |
|
|
|
ret = bcache_device_init(&dc->disk, block_size, |
|
bdev_nr_sectors(dc->bdev) - dc->sb.data_offset, |
|
dc->bdev, &bcache_cached_ops); |
|
if (ret) |
|
return ret; |
|
|
|
blk_queue_io_opt(dc->disk.disk->queue, |
|
max(queue_io_opt(dc->disk.disk->queue), queue_io_opt(q))); |
|
|
|
atomic_set(&dc->io_errors, 0); |
|
dc->io_disable = false; |
|
dc->error_limit = DEFAULT_CACHED_DEV_ERROR_LIMIT; |
|
/* default to auto */ |
|
dc->stop_when_cache_set_failed = BCH_CACHED_DEV_STOP_AUTO; |
|
|
|
bch_cached_dev_request_init(dc); |
|
bch_cached_dev_writeback_init(dc); |
|
return 0; |
|
} |
|
|
|
/* Cached device - bcache superblock */ |
|
|
|
static int register_bdev(struct cache_sb *sb, struct cache_sb_disk *sb_disk, |
|
struct block_device *bdev, |
|
struct cached_dev *dc) |
|
{ |
|
const char *err = "cannot allocate memory"; |
|
struct cache_set *c; |
|
int ret = -ENOMEM; |
|
|
|
bdevname(bdev, dc->backing_dev_name); |
|
memcpy(&dc->sb, sb, sizeof(struct cache_sb)); |
|
dc->bdev = bdev; |
|
dc->bdev->bd_holder = dc; |
|
dc->sb_disk = sb_disk; |
|
|
|
if (cached_dev_init(dc, sb->block_size << 9)) |
|
goto err; |
|
|
|
err = "error creating kobject"; |
|
if (kobject_add(&dc->disk.kobj, bdev_kobj(bdev), "bcache")) |
|
goto err; |
|
if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj)) |
|
goto err; |
|
|
|
pr_info("registered backing device %s\n", dc->backing_dev_name); |
|
|
|
list_add(&dc->list, &uncached_devices); |
|
/* attach to a matched cache set if it exists */ |
|
list_for_each_entry(c, &bch_cache_sets, list) |
|
bch_cached_dev_attach(dc, c, NULL); |
|
|
|
if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE || |
|
BDEV_STATE(&dc->sb) == BDEV_STATE_STALE) { |
|
err = "failed to run cached device"; |
|
ret = bch_cached_dev_run(dc); |
|
if (ret) |
|
goto err; |
|
} |
|
|
|
return 0; |
|
err: |
|
pr_notice("error %s: %s\n", dc->backing_dev_name, err); |
|
bcache_device_stop(&dc->disk); |
|
return ret; |
|
} |
|
|
|
/* Flash only volumes */ |
|
|
|
/* When d->kobj released */ |
|
void bch_flash_dev_release(struct kobject *kobj) |
|
{ |
|
struct bcache_device *d = container_of(kobj, struct bcache_device, |
|
kobj); |
|
kfree(d); |
|
} |
|
|
|
static void flash_dev_free(struct closure *cl) |
|
{ |
|
struct bcache_device *d = container_of(cl, struct bcache_device, cl); |
|
|
|
mutex_lock(&bch_register_lock); |
|
atomic_long_sub(bcache_dev_sectors_dirty(d), |
|
&d->c->flash_dev_dirty_sectors); |
|
del_gendisk(d->disk); |
|
bcache_device_free(d); |
|
mutex_unlock(&bch_register_lock); |
|
kobject_put(&d->kobj); |
|
} |
|
|
|
static void flash_dev_flush(struct closure *cl) |
|
{ |
|
struct bcache_device *d = container_of(cl, struct bcache_device, cl); |
|
|
|
mutex_lock(&bch_register_lock); |
|
bcache_device_unlink(d); |
|
mutex_unlock(&bch_register_lock); |
|
kobject_del(&d->kobj); |
|
continue_at(cl, flash_dev_free, system_wq); |
|
} |
|
|
|
static int flash_dev_run(struct cache_set *c, struct uuid_entry *u) |
|
{ |
|
struct bcache_device *d = kzalloc(sizeof(struct bcache_device), |
|
GFP_KERNEL); |
|
if (!d) |
|
return -ENOMEM; |
|
|
|
closure_init(&d->cl, NULL); |
|
set_closure_fn(&d->cl, flash_dev_flush, system_wq); |
|
|
|
kobject_init(&d->kobj, &bch_flash_dev_ktype); |
|
|
|
if (bcache_device_init(d, block_bytes(c->cache), u->sectors, |
|
NULL, &bcache_flash_ops)) |
|
goto err; |
|
|
|
bcache_device_attach(d, c, u - c->uuids); |
|
bch_sectors_dirty_init(d); |
|
bch_flash_dev_request_init(d); |
|
add_disk(d->disk); |
|
|
|
if (kobject_add(&d->kobj, &disk_to_dev(d->disk)->kobj, "bcache")) |
|
goto err; |
|
|
|
bcache_device_link(d, c, "volume"); |
|
|
|
if (bch_has_feature_obso_large_bucket(&c->cache->sb)) { |
|
pr_err("The obsoleted large bucket layout is unsupported, set the bcache device into read-only\n"); |
|
pr_err("Please update to the latest bcache-tools to create the cache device\n"); |
|
set_disk_ro(d->disk, 1); |
|
} |
|
|
|
return 0; |
|
err: |
|
kobject_put(&d->kobj); |
|
return -ENOMEM; |
|
} |
|
|
|
static int flash_devs_run(struct cache_set *c) |
|
{ |
|
int ret = 0; |
|
struct uuid_entry *u; |
|
|
|
for (u = c->uuids; |
|
u < c->uuids + c->nr_uuids && !ret; |
|
u++) |
|
if (UUID_FLASH_ONLY(u)) |
|
ret = flash_dev_run(c, u); |
|
|
|
return ret; |
|
} |
|
|
|
int bch_flash_dev_create(struct cache_set *c, uint64_t size) |
|
{ |
|
struct uuid_entry *u; |
|
|
|
if (test_bit(CACHE_SET_STOPPING, &c->flags)) |
|
return -EINTR; |
|
|
|
if (!test_bit(CACHE_SET_RUNNING, &c->flags)) |
|
return -EPERM; |
|
|
|
u = uuid_find_empty(c); |
|
if (!u) { |
|
pr_err("Can't create volume, no room for UUID\n"); |
|
return -EINVAL; |
|
} |
|
|
|
get_random_bytes(u->uuid, 16); |
|
memset(u->label, 0, 32); |
|
u->first_reg = u->last_reg = cpu_to_le32((u32)ktime_get_real_seconds()); |
|
|
|
SET_UUID_FLASH_ONLY(u, 1); |
|
u->sectors = size >> 9; |
|
|
|
bch_uuid_write(c); |
|
|
|
return flash_dev_run(c, u); |
|
} |
|
|
|
bool bch_cached_dev_error(struct cached_dev *dc) |
|
{ |
|
if (!dc || test_bit(BCACHE_DEV_CLOSING, &dc->disk.flags)) |
|
return false; |
|
|
|
dc->io_disable = true; |
|
/* make others know io_disable is true earlier */ |
|
smp_mb(); |
|
|
|
pr_err("stop %s: too many IO errors on backing device %s\n", |
|
dc->disk.disk->disk_name, dc->backing_dev_name); |
|
|
|
bcache_device_stop(&dc->disk); |
|
return true; |
|
} |
|
|
|
/* Cache set */ |
|
|
|
__printf(2, 3) |
|
bool bch_cache_set_error(struct cache_set *c, const char *fmt, ...) |
|
{ |
|
struct va_format vaf; |
|
va_list args; |
|
|
|
if (c->on_error != ON_ERROR_PANIC && |
|
test_bit(CACHE_SET_STOPPING, &c->flags)) |
|
return false; |
|
|
|
if (test_and_set_bit(CACHE_SET_IO_DISABLE, &c->flags)) |
|
pr_info("CACHE_SET_IO_DISABLE already set\n"); |
|
|
|
/* |
|
* XXX: we can be called from atomic context |
|
* acquire_console_sem(); |
|
*/ |
|
|
|
va_start(args, fmt); |
|
|
|
vaf.fmt = fmt; |
|
vaf.va = &args; |
|
|
|
pr_err("error on %pU: %pV, disabling caching\n", |
|
c->set_uuid, &vaf); |
|
|
|
va_end(args); |
|
|
|
if (c->on_error == ON_ERROR_PANIC) |
|
panic("panic forced after error\n"); |
|
|
|
bch_cache_set_unregister(c); |
|
return true; |
|
} |
|
|
|
/* When c->kobj released */ |
|
void bch_cache_set_release(struct kobject *kobj) |
|
{ |
|
struct cache_set *c = container_of(kobj, struct cache_set, kobj); |
|
|
|
kfree(c); |
|
module_put(THIS_MODULE); |
|
} |
|
|
|
static void cache_set_free(struct closure *cl) |
|
{ |
|
struct cache_set *c = container_of(cl, struct cache_set, cl); |
|
struct cache *ca; |
|
|
|
debugfs_remove(c->debug); |
|
|
|
bch_open_buckets_free(c); |
|
bch_btree_cache_free(c); |
|
bch_journal_free(c); |
|
|
|
mutex_lock(&bch_register_lock); |
|
bch_bset_sort_state_free(&c->sort); |
|
free_pages((unsigned long) c->uuids, ilog2(meta_bucket_pages(&c->cache->sb))); |
|
|
|
ca = c->cache; |
|
if (ca) { |
|
ca->set = NULL; |
|
c->cache = NULL; |
|
kobject_put(&ca->kobj); |
|
} |
|
|
|
|
|
if (c->moving_gc_wq) |
|
destroy_workqueue(c->moving_gc_wq); |
|
bioset_exit(&c->bio_split); |
|
mempool_exit(&c->fill_iter); |
|
mempool_exit(&c->bio_meta); |
|
mempool_exit(&c->search); |
|
kfree(c->devices); |
|
|
|
list_del(&c->list); |
|
mutex_unlock(&bch_register_lock); |
|
|
|
pr_info("Cache set %pU unregistered\n", c->set_uuid); |
|
wake_up(&unregister_wait); |
|
|
|
closure_debug_destroy(&c->cl); |
|
kobject_put(&c->kobj); |
|
} |
|
|
|
static void cache_set_flush(struct closure *cl) |
|
{ |
|
struct cache_set *c = container_of(cl, struct cache_set, caching); |
|
struct cache *ca = c->cache; |
|
struct btree *b; |
|
|
|
bch_cache_accounting_destroy(&c->accounting); |
|
|
|
kobject_put(&c->internal); |
|
kobject_del(&c->kobj); |
|
|
|
if (!IS_ERR_OR_NULL(c->gc_thread)) |
|
kthread_stop(c->gc_thread); |
|
|
|
if (!IS_ERR_OR_NULL(c->root)) |
|
list_add(&c->root->list, &c->btree_cache); |
|
|
|
/* |
|
* Avoid flushing cached nodes if cache set is retiring |
|
* due to too many I/O errors detected. |
|
*/ |
|
if (!test_bit(CACHE_SET_IO_DISABLE, &c->flags)) |
|
list_for_each_entry(b, &c->btree_cache, list) { |
|
mutex_lock(&b->write_lock); |
|
if (btree_node_dirty(b)) |
|
__bch_btree_node_write(b, NULL); |
|
mutex_unlock(&b->write_lock); |
|
} |
|
|
|
if (ca->alloc_thread) |
|
kthread_stop(ca->alloc_thread); |
|
|
|
if (c->journal.cur) { |
|
cancel_delayed_work_sync(&c->journal.work); |
|
/* flush last journal entry if needed */ |
|
c->journal.work.work.func(&c->journal.work.work); |
|
} |
|
|
|
closure_return(cl); |
|
} |
|
|
|
/* |
|
* This function is only called when CACHE_SET_IO_DISABLE is set, which means |
|
* cache set is unregistering due to too many I/O errors. In this condition, |
|
* the bcache device might be stopped, it depends on stop_when_cache_set_failed |
|
* value and whether the broken cache has dirty data: |
|
* |
|
* dc->stop_when_cache_set_failed dc->has_dirty stop bcache device |
|
* BCH_CACHED_STOP_AUTO 0 NO |
|
* BCH_CACHED_STOP_AUTO 1 YES |
|
* BCH_CACHED_DEV_STOP_ALWAYS 0 YES |
|
* BCH_CACHED_DEV_STOP_ALWAYS 1 YES |
|
* |
|
* The expected behavior is, if stop_when_cache_set_failed is configured to |
|
* "auto" via sysfs interface, the bcache device will not be stopped if the |
|
* backing device is clean on the broken cache device. |
|
*/ |
|
static void conditional_stop_bcache_device(struct cache_set *c, |
|
struct bcache_device *d, |
|
struct cached_dev *dc) |
|
{ |
|
if (dc->stop_when_cache_set_failed == BCH_CACHED_DEV_STOP_ALWAYS) { |
|
pr_warn("stop_when_cache_set_failed of %s is \"always\", stop it for failed cache set %pU.\n", |
|
d->disk->disk_name, c->set_uuid); |
|
bcache_device_stop(d); |
|
} else if (atomic_read(&dc->has_dirty)) { |
|
/* |
|
* dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO |
|
* and dc->has_dirty == 1 |
|
*/ |
|
pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is dirty, stop it to avoid potential data corruption.\n", |
|
d->disk->disk_name); |
|
/* |
|
* There might be a small time gap that cache set is |
|
* released but bcache device is not. Inside this time |
|
* gap, regular I/O requests will directly go into |
|
* backing device as no cache set attached to. This |
|
* behavior may also introduce potential inconsistence |
|
* data in writeback mode while cache is dirty. |
|
* Therefore before calling bcache_device_stop() due |
|
* to a broken cache device, dc->io_disable should be |
|
* explicitly set to true. |
|
*/ |
|
dc->io_disable = true; |
|
/* make others know io_disable is true earlier */ |
|
smp_mb(); |
|
bcache_device_stop(d); |
|
} else { |
|
/* |
|
* dc->stop_when_cache_set_failed == BCH_CACHED_STOP_AUTO |
|
* and dc->has_dirty == 0 |
|
*/ |
|
pr_warn("stop_when_cache_set_failed of %s is \"auto\" and cache is clean, keep it alive.\n", |
|
d->disk->disk_name); |
|
} |
|
} |
|
|
|
static void __cache_set_unregister(struct closure *cl) |
|
{ |
|
struct cache_set *c = container_of(cl, struct cache_set, caching); |
|
struct cached_dev *dc; |
|
struct bcache_device *d; |
|
size_t i; |
|
|
|
mutex_lock(&bch_register_lock); |
|
|
|
for (i = 0; i < c->devices_max_used; i++) { |
|
d = c->devices[i]; |
|
if (!d) |
|
continue; |
|
|
|
if (!UUID_FLASH_ONLY(&c->uuids[i]) && |
|
test_bit(CACHE_SET_UNREGISTERING, &c->flags)) { |
|
dc = container_of(d, struct cached_dev, disk); |
|
bch_cached_dev_detach(dc); |
|
if (test_bit(CACHE_SET_IO_DISABLE, &c->flags)) |
|
conditional_stop_bcache_device(c, d, dc); |
|
} else { |
|
bcache_device_stop(d); |
|
} |
|
} |
|
|
|
mutex_unlock(&bch_register_lock); |
|
|
|
continue_at(cl, cache_set_flush, system_wq); |
|
} |
|
|
|
void bch_cache_set_stop(struct cache_set *c) |
|
{ |
|
if (!test_and_set_bit(CACHE_SET_STOPPING, &c->flags)) |
|
/* closure_fn set to __cache_set_unregister() */ |
|
closure_queue(&c->caching); |
|
} |
|
|
|
void bch_cache_set_unregister(struct cache_set *c) |
|
{ |
|
set_bit(CACHE_SET_UNREGISTERING, &c->flags); |
|
bch_cache_set_stop(c); |
|
} |
|
|
|
#define alloc_meta_bucket_pages(gfp, sb) \ |
|
((void *) __get_free_pages(__GFP_ZERO|__GFP_COMP|gfp, ilog2(meta_bucket_pages(sb)))) |
|
|
|
struct cache_set *bch_cache_set_alloc(struct cache_sb *sb) |
|
{ |
|
int iter_size; |
|
struct cache *ca = container_of(sb, struct cache, sb); |
|
struct cache_set *c = kzalloc(sizeof(struct cache_set), GFP_KERNEL); |
|
|
|
if (!c) |
|
return NULL; |
|
|
|
__module_get(THIS_MODULE); |
|
closure_init(&c->cl, NULL); |
|
set_closure_fn(&c->cl, cache_set_free, system_wq); |
|
|
|
closure_init(&c->caching, &c->cl); |
|
set_closure_fn(&c->caching, __cache_set_unregister, system_wq); |
|
|
|
/* Maybe create continue_at_noreturn() and use it here? */ |
|
closure_set_stopped(&c->cl); |
|
closure_put(&c->cl); |
|
|
|
kobject_init(&c->kobj, &bch_cache_set_ktype); |
|
kobject_init(&c->internal, &bch_cache_set_internal_ktype); |
|
|
|
bch_cache_accounting_init(&c->accounting, &c->cl); |
|
|
|
memcpy(c->set_uuid, sb->set_uuid, 16); |
|
|
|
c->cache = ca; |
|
c->cache->set = c; |
|
c->bucket_bits = ilog2(sb->bucket_size); |
|
c->block_bits = ilog2(sb->block_size); |
|
c->nr_uuids = meta_bucket_bytes(sb) / sizeof(struct uuid_entry); |
|
c->devices_max_used = 0; |
|
atomic_set(&c->attached_dev_nr, 0); |
|
c->btree_pages = meta_bucket_pages(sb); |
|
if (c->btree_pages > BTREE_MAX_PAGES) |
|
c->btree_pages = max_t(int, c->btree_pages / 4, |
|
BTREE_MAX_PAGES); |
|
|
|
sema_init(&c->sb_write_mutex, 1); |
|
mutex_init(&c->bucket_lock); |
|
init_waitqueue_head(&c->btree_cache_wait); |
|
spin_lock_init(&c->btree_cannibalize_lock); |
|
init_waitqueue_head(&c->bucket_wait); |
|
init_waitqueue_head(&c->gc_wait); |
|
sema_init(&c->uuid_write_mutex, 1); |
|
|
|
spin_lock_init(&c->btree_gc_time.lock); |
|
spin_lock_init(&c->btree_split_time.lock); |
|
spin_lock_init(&c->btree_read_time.lock); |
|
|
|
bch_moving_init_cache_set(c); |
|
|
|
INIT_LIST_HEAD(&c->list); |
|
INIT_LIST_HEAD(&c->cached_devs); |
|
INIT_LIST_HEAD(&c->btree_cache); |
|
INIT_LIST_HEAD(&c->btree_cache_freeable); |
|
INIT_LIST_HEAD(&c->btree_cache_freed); |
|
INIT_LIST_HEAD(&c->data_buckets); |
|
|
|
iter_size = ((meta_bucket_pages(sb) * PAGE_SECTORS) / sb->block_size + 1) * |
|
sizeof(struct btree_iter_set); |
|
|
|
c->devices = kcalloc(c->nr_uuids, sizeof(void *), GFP_KERNEL); |
|
if (!c->devices) |
|
goto err; |
|
|
|
if (mempool_init_slab_pool(&c->search, 32, bch_search_cache)) |
|
goto err; |
|
|
|
if (mempool_init_kmalloc_pool(&c->bio_meta, 2, |
|
sizeof(struct bbio) + |
|
sizeof(struct bio_vec) * meta_bucket_pages(sb))) |
|
goto err; |
|
|
|
if (mempool_init_kmalloc_pool(&c->fill_iter, 1, iter_size)) |
|
goto err; |
|
|
|
if (bioset_init(&c->bio_split, 4, offsetof(struct bbio, bio), |
|
BIOSET_NEED_RESCUER)) |
|
goto err; |
|
|
|
c->uuids = alloc_meta_bucket_pages(GFP_KERNEL, sb); |
|
if (!c->uuids) |
|
goto err; |
|
|
|
c->moving_gc_wq = alloc_workqueue("bcache_gc", WQ_MEM_RECLAIM, 0); |
|
if (!c->moving_gc_wq) |
|
goto err; |
|
|
|
if (bch_journal_alloc(c)) |
|
goto err; |
|
|
|
if (bch_btree_cache_alloc(c)) |
|
goto err; |
|
|
|
if (bch_open_buckets_alloc(c)) |
|
goto err; |
|
|
|
if (bch_bset_sort_state_init(&c->sort, ilog2(c->btree_pages))) |
|
goto err; |
|
|
|
c->congested_read_threshold_us = 2000; |
|
c->congested_write_threshold_us = 20000; |
|
c->error_limit = DEFAULT_IO_ERROR_LIMIT; |
|
c->idle_max_writeback_rate_enabled = 1; |
|
WARN_ON(test_and_clear_bit(CACHE_SET_IO_DISABLE, &c->flags)); |
|
|
|
return c; |
|
err: |
|
bch_cache_set_unregister(c); |
|
return NULL; |
|
} |
|
|
|
static int run_cache_set(struct cache_set *c) |
|
{ |
|
const char *err = "cannot allocate memory"; |
|
struct cached_dev *dc, *t; |
|
struct cache *ca = c->cache; |
|
struct closure cl; |
|
LIST_HEAD(journal); |
|
struct journal_replay *l; |
|
|
|
closure_init_stack(&cl); |
|
|
|
c->nbuckets = ca->sb.nbuckets; |
|
set_gc_sectors(c); |
|
|
|
if (CACHE_SYNC(&c->cache->sb)) { |
|
struct bkey *k; |
|
struct jset *j; |
|
|
|
err = "cannot allocate memory for journal"; |
|
if (bch_journal_read(c, &journal)) |
|
goto err; |
|
|
|
pr_debug("btree_journal_read() done\n"); |
|
|
|
err = "no journal entries found"; |
|
if (list_empty(&journal)) |
|
goto err; |
|
|
|
j = &list_entry(journal.prev, struct journal_replay, list)->j; |
|
|
|
err = "IO error reading priorities"; |
|
if (prio_read(ca, j->prio_bucket[ca->sb.nr_this_dev])) |
|
goto err; |
|
|
|
/* |
|
* If prio_read() fails it'll call cache_set_error and we'll |
|
* tear everything down right away, but if we perhaps checked |
|
* sooner we could avoid journal replay. |
|
*/ |
|
|
|
k = &j->btree_root; |
|
|
|
err = "bad btree root"; |
|
if (__bch_btree_ptr_invalid(c, k)) |
|
goto err; |
|
|
|
err = "error reading btree root"; |
|
c->root = bch_btree_node_get(c, NULL, k, |
|
j->btree_level, |
|
true, NULL); |
|
if (IS_ERR_OR_NULL(c->root)) |
|
goto err; |
|
|
|
list_del_init(&c->root->list); |
|
rw_unlock(true, c->root); |
|
|
|
err = uuid_read(c, j, &cl); |
|
if (err) |
|
goto err; |
|
|
|
err = "error in recovery"; |
|
if (bch_btree_check(c)) |
|
goto err; |
|
|
|
bch_journal_mark(c, &journal); |
|
bch_initial_gc_finish(c); |
|
pr_debug("btree_check() done\n"); |
|
|
|
/* |
|
* bcache_journal_next() can't happen sooner, or |
|
* btree_gc_finish() will give spurious errors about last_gc > |
|
* gc_gen - this is a hack but oh well. |
|
*/ |
|
bch_journal_next(&c->journal); |
|
|
|
err = "error starting allocator thread"; |
|
if (bch_cache_allocator_start(ca)) |
|
goto err; |
|
|
|
/* |
|
* First place it's safe to allocate: btree_check() and |
|
* btree_gc_finish() have to run before we have buckets to |
|
* allocate, and bch_bucket_alloc_set() might cause a journal |
|
* entry to be written so bcache_journal_next() has to be called |
|
* first. |
|
* |
|
* If the uuids were in the old format we have to rewrite them |
|
* before the next journal entry is written: |
|
*/ |
|
if (j->version < BCACHE_JSET_VERSION_UUID) |
|
__uuid_write(c); |
|
|
|
err = "bcache: replay journal failed"; |
|
if (bch_journal_replay(c, &journal)) |
|
goto err; |
|
} else { |
|
unsigned int j; |
|
|
|
pr_notice("invalidating existing data\n"); |
|
ca->sb.keys = clamp_t(int, ca->sb.nbuckets >> 7, |
|
2, SB_JOURNAL_BUCKETS); |
|
|
|
for (j = 0; j < ca->sb.keys; j++) |
|
ca->sb.d[j] = ca->sb.first_bucket + j; |
|
|
|
bch_initial_gc_finish(c); |
|
|
|
err = "error starting allocator thread"; |
|
if (bch_cache_allocator_start(ca)) |
|
goto err; |
|
|
|
mutex_lock(&c->bucket_lock); |
|
bch_prio_write(ca, true); |
|
mutex_unlock(&c->bucket_lock); |
|
|
|
err = "cannot allocate new UUID bucket"; |
|
if (__uuid_write(c)) |
|
goto err; |
|
|
|
err = "cannot allocate new btree root"; |
|
c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL); |
|
if (IS_ERR_OR_NULL(c->root)) |
|
goto err; |
|
|
|
mutex_lock(&c->root->write_lock); |
|
bkey_copy_key(&c->root->key, &MAX_KEY); |
|
bch_btree_node_write(c->root, &cl); |
|
mutex_unlock(&c->root->write_lock); |
|
|
|
bch_btree_set_root(c->root); |
|
rw_unlock(true, c->root); |
|
|
|
/* |
|
* We don't want to write the first journal entry until |
|
* everything is set up - fortunately journal entries won't be |
|
* written until the SET_CACHE_SYNC() here: |
|
*/ |
|
SET_CACHE_SYNC(&c->cache->sb, true); |
|
|
|
bch_journal_next(&c->journal); |
|
bch_journal_meta(c, &cl); |
|
} |
|
|
|
err = "error starting gc thread"; |
|
if (bch_gc_thread_start(c)) |
|
goto err; |
|
|
|
closure_sync(&cl); |
|
c->cache->sb.last_mount = (u32)ktime_get_real_seconds(); |
|
bcache_write_super(c); |
|
|
|
if (bch_has_feature_obso_large_bucket(&c->cache->sb)) |
|
pr_err("Detect obsoleted large bucket layout, all attached bcache device will be read-only\n"); |
|
|
|
list_for_each_entry_safe(dc, t, &uncached_devices, list) |
|
bch_cached_dev_attach(dc, c, NULL); |
|
|
|
flash_devs_run(c); |
|
|
|
set_bit(CACHE_SET_RUNNING, &c->flags); |
|
return 0; |
|
err: |
|
while (!list_empty(&journal)) { |
|
l = list_first_entry(&journal, struct journal_replay, list); |
|
list_del(&l->list); |
|
kfree(l); |
|
} |
|
|
|
closure_sync(&cl); |
|
|
|
bch_cache_set_error(c, "%s", err); |
|
|
|
return -EIO; |
|
} |
|
|
|
static const char *register_cache_set(struct cache *ca) |
|
{ |
|
char buf[12]; |
|
const char *err = "cannot allocate memory"; |
|
struct cache_set *c; |
|
|
|
list_for_each_entry(c, &bch_cache_sets, list) |
|
if (!memcmp(c->set_uuid, ca->sb.set_uuid, 16)) { |
|
if (c->cache) |
|
return "duplicate cache set member"; |
|
|
|
goto found; |
|
} |
|
|
|
c = bch_cache_set_alloc(&ca->sb); |
|
if (!c) |
|
return err; |
|
|
|
err = "error creating kobject"; |
|
if (kobject_add(&c->kobj, bcache_kobj, "%pU", c->set_uuid) || |
|
kobject_add(&c->internal, &c->kobj, "internal")) |
|
goto err; |
|
|
|
if (bch_cache_accounting_add_kobjs(&c->accounting, &c->kobj)) |
|
goto err; |
|
|
|
bch_debug_init_cache_set(c); |
|
|
|
list_add(&c->list, &bch_cache_sets); |
|
found: |
|
sprintf(buf, "cache%i", ca->sb.nr_this_dev); |
|
if (sysfs_create_link(&ca->kobj, &c->kobj, "set") || |
|
sysfs_create_link(&c->kobj, &ca->kobj, buf)) |
|
goto err; |
|
|
|
kobject_get(&ca->kobj); |
|
ca->set = c; |
|
ca->set->cache = ca; |
|
|
|
err = "failed to run cache set"; |
|
if (run_cache_set(c) < 0) |
|
goto err; |
|
|
|
return NULL; |
|
err: |
|
bch_cache_set_unregister(c); |
|
return err; |
|
} |
|
|
|
/* Cache device */ |
|
|
|
/* When ca->kobj released */ |
|
void bch_cache_release(struct kobject *kobj) |
|
{ |
|
struct cache *ca = container_of(kobj, struct cache, kobj); |
|
unsigned int i; |
|
|
|
if (ca->set) { |
|
BUG_ON(ca->set->cache != ca); |
|
ca->set->cache = NULL; |
|
} |
|
|
|
free_pages((unsigned long) ca->disk_buckets, ilog2(meta_bucket_pages(&ca->sb))); |
|
kfree(ca->prio_buckets); |
|
vfree(ca->buckets); |
|
|
|
free_heap(&ca->heap); |
|
free_fifo(&ca->free_inc); |
|
|
|
for (i = 0; i < RESERVE_NR; i++) |
|
free_fifo(&ca->free[i]); |
|
|
|
if (ca->sb_disk) |
|
put_page(virt_to_page(ca->sb_disk)); |
|
|
|
if (!IS_ERR_OR_NULL(ca->bdev)) |
|
blkdev_put(ca->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
|
|
|
kfree(ca); |
|
module_put(THIS_MODULE); |
|
} |
|
|
|
static int cache_alloc(struct cache *ca) |
|
{ |
|
size_t free; |
|
size_t btree_buckets; |
|
struct bucket *b; |
|
int ret = -ENOMEM; |
|
const char *err = NULL; |
|
|
|
__module_get(THIS_MODULE); |
|
kobject_init(&ca->kobj, &bch_cache_ktype); |
|
|
|
bio_init(&ca->journal.bio, ca->journal.bio.bi_inline_vecs, 8); |
|
|
|
/* |
|
* when ca->sb.njournal_buckets is not zero, journal exists, |
|
* and in bch_journal_replay(), tree node may split, |
|
* so bucket of RESERVE_BTREE type is needed, |
|
* the worst situation is all journal buckets are valid journal, |
|
* and all the keys need to replay, |
|
* so the number of RESERVE_BTREE type buckets should be as much |
|
* as journal buckets |
|
*/ |
|
btree_buckets = ca->sb.njournal_buckets ?: 8; |
|
free = roundup_pow_of_two(ca->sb.nbuckets) >> 10; |
|
if (!free) { |
|
ret = -EPERM; |
|
err = "ca->sb.nbuckets is too small"; |
|
goto err_free; |
|
} |
|
|
|
if (!init_fifo(&ca->free[RESERVE_BTREE], btree_buckets, |
|
GFP_KERNEL)) { |
|
err = "ca->free[RESERVE_BTREE] alloc failed"; |
|
goto err_btree_alloc; |
|
} |
|
|
|
if (!init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), |
|
GFP_KERNEL)) { |
|
err = "ca->free[RESERVE_PRIO] alloc failed"; |
|
goto err_prio_alloc; |
|
} |
|
|
|
if (!init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL)) { |
|
err = "ca->free[RESERVE_MOVINGGC] alloc failed"; |
|
goto err_movinggc_alloc; |
|
} |
|
|
|
if (!init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL)) { |
|
err = "ca->free[RESERVE_NONE] alloc failed"; |
|
goto err_none_alloc; |
|
} |
|
|
|
if (!init_fifo(&ca->free_inc, free << 2, GFP_KERNEL)) { |
|
err = "ca->free_inc alloc failed"; |
|
goto err_free_inc_alloc; |
|
} |
|
|
|
if (!init_heap(&ca->heap, free << 3, GFP_KERNEL)) { |
|
err = "ca->heap alloc failed"; |
|
goto err_heap_alloc; |
|
} |
|
|
|
ca->buckets = vzalloc(array_size(sizeof(struct bucket), |
|
ca->sb.nbuckets)); |
|
if (!ca->buckets) { |
|
err = "ca->buckets alloc failed"; |
|
goto err_buckets_alloc; |
|
} |
|
|
|
ca->prio_buckets = kzalloc(array3_size(sizeof(uint64_t), |
|
prio_buckets(ca), 2), |
|
GFP_KERNEL); |
|
if (!ca->prio_buckets) { |
|
err = "ca->prio_buckets alloc failed"; |
|
goto err_prio_buckets_alloc; |
|
} |
|
|
|
ca->disk_buckets = alloc_meta_bucket_pages(GFP_KERNEL, &ca->sb); |
|
if (!ca->disk_buckets) { |
|
err = "ca->disk_buckets alloc failed"; |
|
goto err_disk_buckets_alloc; |
|
} |
|
|
|
ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca); |
|
|
|
for_each_bucket(b, ca) |
|
atomic_set(&b->pin, 0); |
|
return 0; |
|
|
|
err_disk_buckets_alloc: |
|
kfree(ca->prio_buckets); |
|
err_prio_buckets_alloc: |
|
vfree(ca->buckets); |
|
err_buckets_alloc: |
|
free_heap(&ca->heap); |
|
err_heap_alloc: |
|
free_fifo(&ca->free_inc); |
|
err_free_inc_alloc: |
|
free_fifo(&ca->free[RESERVE_NONE]); |
|
err_none_alloc: |
|
free_fifo(&ca->free[RESERVE_MOVINGGC]); |
|
err_movinggc_alloc: |
|
free_fifo(&ca->free[RESERVE_PRIO]); |
|
err_prio_alloc: |
|
free_fifo(&ca->free[RESERVE_BTREE]); |
|
err_btree_alloc: |
|
err_free: |
|
module_put(THIS_MODULE); |
|
if (err) |
|
pr_notice("error %s: %s\n", ca->cache_dev_name, err); |
|
return ret; |
|
} |
|
|
|
static int register_cache(struct cache_sb *sb, struct cache_sb_disk *sb_disk, |
|
struct block_device *bdev, struct cache *ca) |
|
{ |
|
const char *err = NULL; /* must be set for any error case */ |
|
int ret = 0; |
|
|
|
bdevname(bdev, ca->cache_dev_name); |
|
memcpy(&ca->sb, sb, sizeof(struct cache_sb)); |
|
ca->bdev = bdev; |
|
ca->bdev->bd_holder = ca; |
|
ca->sb_disk = sb_disk; |
|
|
|
if (blk_queue_discard(bdev_get_queue(bdev))) |
|
ca->discard = CACHE_DISCARD(&ca->sb); |
|
|
|
ret = cache_alloc(ca); |
|
if (ret != 0) { |
|
/* |
|
* If we failed here, it means ca->kobj is not initialized yet, |
|
* kobject_put() won't be called and there is no chance to |
|
* call blkdev_put() to bdev in bch_cache_release(). So we |
|
* explicitly call blkdev_put() here. |
|
*/ |
|
blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL); |
|
if (ret == -ENOMEM) |
|
err = "cache_alloc(): -ENOMEM"; |
|
else if (ret == -EPERM) |
|
err = "cache_alloc(): cache device is too small"; |
|
else |
|
err = "cache_alloc(): unknown error"; |
|
goto err; |
|
} |
|
|
|
if (kobject_add(&ca->kobj, bdev_kobj(bdev), "bcache")) { |
|
err = "error calling kobject_add"; |
|
ret = -ENOMEM; |
|
goto out; |
|
} |
|
|
|
mutex_lock(&bch_register_lock); |
|
err = register_cache_set(ca); |
|
mutex_unlock(&bch_register_lock); |
|
|
|
if (err) { |
|
ret = -ENODEV; |
|
goto out; |
|
} |
|
|
|
pr_info("registered cache device %s\n", ca->cache_dev_name); |
|
|
|
out: |
|
kobject_put(&ca->kobj); |
|
|
|
err: |
|
if (err) |
|
pr_notice("error %s: %s\n", ca->cache_dev_name, err); |
|
|
|
return ret; |
|
} |
|
|
|
/* Global interfaces/init */ |
|
|
|
static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, |
|
const char *buffer, size_t size); |
|
static ssize_t bch_pending_bdevs_cleanup(struct kobject *k, |
|
struct kobj_attribute *attr, |
|
const char *buffer, size_t size); |
|
|
|
kobj_attribute_write(register, register_bcache); |
|
kobj_attribute_write(register_quiet, register_bcache); |
|
kobj_attribute_write(pendings_cleanup, bch_pending_bdevs_cleanup); |
|
|
|
static bool bch_is_open_backing(dev_t dev) |
|
{ |
|
struct cache_set *c, *tc; |
|
struct cached_dev *dc, *t; |
|
|
|
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) |
|
list_for_each_entry_safe(dc, t, &c->cached_devs, list) |
|
if (dc->bdev->bd_dev == dev) |
|
return true; |
|
list_for_each_entry_safe(dc, t, &uncached_devices, list) |
|
if (dc->bdev->bd_dev == dev) |
|
return true; |
|
return false; |
|
} |
|
|
|
static bool bch_is_open_cache(dev_t dev) |
|
{ |
|
struct cache_set *c, *tc; |
|
|
|
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) { |
|
struct cache *ca = c->cache; |
|
|
|
if (ca->bdev->bd_dev == dev) |
|
return true; |
|
} |
|
|
|
return false; |
|
} |
|
|
|
static bool bch_is_open(dev_t dev) |
|
{ |
|
return bch_is_open_cache(dev) || bch_is_open_backing(dev); |
|
} |
|
|
|
struct async_reg_args { |
|
struct delayed_work reg_work; |
|
char *path; |
|
struct cache_sb *sb; |
|
struct cache_sb_disk *sb_disk; |
|
struct block_device *bdev; |
|
}; |
|
|
|
static void register_bdev_worker(struct work_struct *work) |
|
{ |
|
int fail = false; |
|
struct async_reg_args *args = |
|
container_of(work, struct async_reg_args, reg_work.work); |
|
struct cached_dev *dc; |
|
|
|
dc = kzalloc(sizeof(*dc), GFP_KERNEL); |
|
if (!dc) { |
|
fail = true; |
|
put_page(virt_to_page(args->sb_disk)); |
|
blkdev_put(args->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); |
|
goto out; |
|
} |
|
|
|
mutex_lock(&bch_register_lock); |
|
if (register_bdev(args->sb, args->sb_disk, args->bdev, dc) < 0) |
|
fail = true; |
|
mutex_unlock(&bch_register_lock); |
|
|
|
out: |
|
if (fail) |
|
pr_info("error %s: fail to register backing device\n", |
|
args->path); |
|
kfree(args->sb); |
|
kfree(args->path); |
|
kfree(args); |
|
module_put(THIS_MODULE); |
|
} |
|
|
|
static void register_cache_worker(struct work_struct *work) |
|
{ |
|
int fail = false; |
|
struct async_reg_args *args = |
|
container_of(work, struct async_reg_args, reg_work.work); |
|
struct cache *ca; |
|
|
|
ca = kzalloc(sizeof(*ca), GFP_KERNEL); |
|
if (!ca) { |
|
fail = true; |
|
put_page(virt_to_page(args->sb_disk)); |
|
blkdev_put(args->bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); |
|
goto out; |
|
} |
|
|
|
/* blkdev_put() will be called in bch_cache_release() */ |
|
if (register_cache(args->sb, args->sb_disk, args->bdev, ca) != 0) |
|
fail = true; |
|
|
|
out: |
|
if (fail) |
|
pr_info("error %s: fail to register cache device\n", |
|
args->path); |
|
kfree(args->sb); |
|
kfree(args->path); |
|
kfree(args); |
|
module_put(THIS_MODULE); |
|
} |
|
|
|
static void register_device_async(struct async_reg_args *args) |
|
{ |
|
if (SB_IS_BDEV(args->sb)) |
|
INIT_DELAYED_WORK(&args->reg_work, register_bdev_worker); |
|
else |
|
INIT_DELAYED_WORK(&args->reg_work, register_cache_worker); |
|
|
|
/* 10 jiffies is enough for a delay */ |
|
queue_delayed_work(system_wq, &args->reg_work, 10); |
|
} |
|
|
|
static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr, |
|
const char *buffer, size_t size) |
|
{ |
|
const char *err; |
|
char *path = NULL; |
|
struct cache_sb *sb; |
|
struct cache_sb_disk *sb_disk; |
|
struct block_device *bdev; |
|
ssize_t ret; |
|
bool async_registration = false; |
|
|
|
#ifdef CONFIG_BCACHE_ASYNC_REGISTRATION |
|
async_registration = true; |
|
#endif |
|
|
|
ret = -EBUSY; |
|
err = "failed to reference bcache module"; |
|
if (!try_module_get(THIS_MODULE)) |
|
goto out; |
|
|
|
/* For latest state of bcache_is_reboot */ |
|
smp_mb(); |
|
err = "bcache is in reboot"; |
|
if (bcache_is_reboot) |
|
goto out_module_put; |
|
|
|
ret = -ENOMEM; |
|
err = "cannot allocate memory"; |
|
path = kstrndup(buffer, size, GFP_KERNEL); |
|
if (!path) |
|
goto out_module_put; |
|
|
|
sb = kmalloc(sizeof(struct cache_sb), GFP_KERNEL); |
|
if (!sb) |
|
goto out_free_path; |
|
|
|
ret = -EINVAL; |
|
err = "failed to open device"; |
|
bdev = blkdev_get_by_path(strim(path), |
|
FMODE_READ|FMODE_WRITE|FMODE_EXCL, |
|
sb); |
|
if (IS_ERR(bdev)) { |
|
if (bdev == ERR_PTR(-EBUSY)) { |
|
dev_t dev; |
|
|
|
mutex_lock(&bch_register_lock); |
|
if (lookup_bdev(strim(path), &dev) == 0 && |
|
bch_is_open(dev)) |
|
err = "device already registered"; |
|
else |
|
err = "device busy"; |
|
mutex_unlock(&bch_register_lock); |
|
if (attr == &ksysfs_register_quiet) |
|
goto done; |
|
} |
|
goto out_free_sb; |
|
} |
|
|
|
err = "failed to set blocksize"; |
|
if (set_blocksize(bdev, 4096)) |
|
goto out_blkdev_put; |
|
|
|
err = read_super(sb, bdev, &sb_disk); |
|
if (err) |
|
goto out_blkdev_put; |
|
|
|
err = "failed to register device"; |
|
|
|
if (async_registration) { |
|
/* register in asynchronous way */ |
|
struct async_reg_args *args = |
|
kzalloc(sizeof(struct async_reg_args), GFP_KERNEL); |
|
|
|
if (!args) { |
|
ret = -ENOMEM; |
|
err = "cannot allocate memory"; |
|
goto out_put_sb_page; |
|
} |
|
|
|
args->path = path; |
|
args->sb = sb; |
|
args->sb_disk = sb_disk; |
|
args->bdev = bdev; |
|
register_device_async(args); |
|
/* No wait and returns to user space */ |
|
goto async_done; |
|
} |
|
|
|
if (SB_IS_BDEV(sb)) { |
|
struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL); |
|
|
|
if (!dc) |
|
goto out_put_sb_page; |
|
|
|
mutex_lock(&bch_register_lock); |
|
ret = register_bdev(sb, sb_disk, bdev, dc); |
|
mutex_unlock(&bch_register_lock); |
|
/* blkdev_put() will be called in cached_dev_free() */ |
|
if (ret < 0) |
|
goto out_free_sb; |
|
} else { |
|
struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL); |
|
|
|
if (!ca) |
|
goto out_put_sb_page; |
|
|
|
/* blkdev_put() will be called in bch_cache_release() */ |
|
if (register_cache(sb, sb_disk, bdev, ca) != 0) |
|
goto out_free_sb; |
|
} |
|
|
|
done: |
|
kfree(sb); |
|
kfree(path); |
|
module_put(THIS_MODULE); |
|
async_done: |
|
return size; |
|
|
|
out_put_sb_page: |
|
put_page(virt_to_page(sb_disk)); |
|
out_blkdev_put: |
|
blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL); |
|
out_free_sb: |
|
kfree(sb); |
|
out_free_path: |
|
kfree(path); |
|
path = NULL; |
|
out_module_put: |
|
module_put(THIS_MODULE); |
|
out: |
|
pr_info("error %s: %s\n", path?path:"", err); |
|
return ret; |
|
} |
|
|
|
|
|
struct pdev { |
|
struct list_head list; |
|
struct cached_dev *dc; |
|
}; |
|
|
|
static ssize_t bch_pending_bdevs_cleanup(struct kobject *k, |
|
struct kobj_attribute *attr, |
|
const char *buffer, |
|
size_t size) |
|
{ |
|
LIST_HEAD(pending_devs); |
|
ssize_t ret = size; |
|
struct cached_dev *dc, *tdc; |
|
struct pdev *pdev, *tpdev; |
|
struct cache_set *c, *tc; |
|
|
|
mutex_lock(&bch_register_lock); |
|
list_for_each_entry_safe(dc, tdc, &uncached_devices, list) { |
|
pdev = kmalloc(sizeof(struct pdev), GFP_KERNEL); |
|
if (!pdev) |
|
break; |
|
pdev->dc = dc; |
|
list_add(&pdev->list, &pending_devs); |
|
} |
|
|
|
list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) { |
|
char *pdev_set_uuid = pdev->dc->sb.set_uuid; |
|
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) { |
|
char *set_uuid = c->set_uuid; |
|
|
|
if (!memcmp(pdev_set_uuid, set_uuid, 16)) { |
|
list_del(&pdev->list); |
|
kfree(pdev); |
|
break; |
|
} |
|
} |
|
} |
|
mutex_unlock(&bch_register_lock); |
|
|
|
list_for_each_entry_safe(pdev, tpdev, &pending_devs, list) { |
|
pr_info("delete pdev %p\n", pdev); |
|
list_del(&pdev->list); |
|
bcache_device_stop(&pdev->dc->disk); |
|
kfree(pdev); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x) |
|
{ |
|
if (bcache_is_reboot) |
|
return NOTIFY_DONE; |
|
|
|
if (code == SYS_DOWN || |
|
code == SYS_HALT || |
|
code == SYS_POWER_OFF) { |
|
DEFINE_WAIT(wait); |
|
unsigned long start = jiffies; |
|
bool stopped = false; |
|
|
|
struct cache_set *c, *tc; |
|
struct cached_dev *dc, *tdc; |
|
|
|
mutex_lock(&bch_register_lock); |
|
|
|
if (bcache_is_reboot) |
|
goto out; |
|
|
|
/* New registration is rejected since now */ |
|
bcache_is_reboot = true; |
|
/* |
|
* Make registering caller (if there is) on other CPU |
|
* core know bcache_is_reboot set to true earlier |
|
*/ |
|
smp_mb(); |
|
|
|
if (list_empty(&bch_cache_sets) && |
|
list_empty(&uncached_devices)) |
|
goto out; |
|
|
|
mutex_unlock(&bch_register_lock); |
|
|
|
pr_info("Stopping all devices:\n"); |
|
|
|
/* |
|
* The reason bch_register_lock is not held to call |
|
* bch_cache_set_stop() and bcache_device_stop() is to |
|
* avoid potential deadlock during reboot, because cache |
|
* set or bcache device stopping process will acqurie |
|
* bch_register_lock too. |
|
* |
|
* We are safe here because bcache_is_reboot sets to |
|
* true already, register_bcache() will reject new |
|
* registration now. bcache_is_reboot also makes sure |
|
* bcache_reboot() won't be re-entered on by other thread, |
|
* so there is no race in following list iteration by |
|
* list_for_each_entry_safe(). |
|
*/ |
|
list_for_each_entry_safe(c, tc, &bch_cache_sets, list) |
|
bch_cache_set_stop(c); |
|
|
|
list_for_each_entry_safe(dc, tdc, &uncached_devices, list) |
|
bcache_device_stop(&dc->disk); |
|
|
|
|
|
/* |
|
* Give an early chance for other kthreads and |
|
* kworkers to stop themselves |
|
*/ |
|
schedule(); |
|
|
|
/* What's a condition variable? */ |
|
while (1) { |
|
long timeout = start + 10 * HZ - jiffies; |
|
|
|
mutex_lock(&bch_register_lock); |
|
stopped = list_empty(&bch_cache_sets) && |
|
list_empty(&uncached_devices); |
|
|
|
if (timeout < 0 || stopped) |
|
break; |
|
|
|
prepare_to_wait(&unregister_wait, &wait, |
|
TASK_UNINTERRUPTIBLE); |
|
|
|
mutex_unlock(&bch_register_lock); |
|
schedule_timeout(timeout); |
|
} |
|
|
|
finish_wait(&unregister_wait, &wait); |
|
|
|
if (stopped) |
|
pr_info("All devices stopped\n"); |
|
else |
|
pr_notice("Timeout waiting for devices to be closed\n"); |
|
out: |
|
mutex_unlock(&bch_register_lock); |
|
} |
|
|
|
return NOTIFY_DONE; |
|
} |
|
|
|
static struct notifier_block reboot = { |
|
.notifier_call = bcache_reboot, |
|
.priority = INT_MAX, /* before any real devices */ |
|
}; |
|
|
|
static void bcache_exit(void) |
|
{ |
|
bch_debug_exit(); |
|
bch_request_exit(); |
|
if (bcache_kobj) |
|
kobject_put(bcache_kobj); |
|
if (bcache_wq) |
|
destroy_workqueue(bcache_wq); |
|
if (bch_journal_wq) |
|
destroy_workqueue(bch_journal_wq); |
|
if (bch_flush_wq) |
|
destroy_workqueue(bch_flush_wq); |
|
bch_btree_exit(); |
|
|
|
if (bcache_major) |
|
unregister_blkdev(bcache_major, "bcache"); |
|
unregister_reboot_notifier(&reboot); |
|
mutex_destroy(&bch_register_lock); |
|
} |
|
|
|
/* Check and fixup module parameters */ |
|
static void check_module_parameters(void) |
|
{ |
|
if (bch_cutoff_writeback_sync == 0) |
|
bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC; |
|
else if (bch_cutoff_writeback_sync > CUTOFF_WRITEBACK_SYNC_MAX) { |
|
pr_warn("set bch_cutoff_writeback_sync (%u) to max value %u\n", |
|
bch_cutoff_writeback_sync, CUTOFF_WRITEBACK_SYNC_MAX); |
|
bch_cutoff_writeback_sync = CUTOFF_WRITEBACK_SYNC_MAX; |
|
} |
|
|
|
if (bch_cutoff_writeback == 0) |
|
bch_cutoff_writeback = CUTOFF_WRITEBACK; |
|
else if (bch_cutoff_writeback > CUTOFF_WRITEBACK_MAX) { |
|
pr_warn("set bch_cutoff_writeback (%u) to max value %u\n", |
|
bch_cutoff_writeback, CUTOFF_WRITEBACK_MAX); |
|
bch_cutoff_writeback = CUTOFF_WRITEBACK_MAX; |
|
} |
|
|
|
if (bch_cutoff_writeback > bch_cutoff_writeback_sync) { |
|
pr_warn("set bch_cutoff_writeback (%u) to %u\n", |
|
bch_cutoff_writeback, bch_cutoff_writeback_sync); |
|
bch_cutoff_writeback = bch_cutoff_writeback_sync; |
|
} |
|
} |
|
|
|
static int __init bcache_init(void) |
|
{ |
|
static const struct attribute *files[] = { |
|
&ksysfs_register.attr, |
|
&ksysfs_register_quiet.attr, |
|
&ksysfs_pendings_cleanup.attr, |
|
NULL |
|
}; |
|
|
|
check_module_parameters(); |
|
|
|
mutex_init(&bch_register_lock); |
|
init_waitqueue_head(&unregister_wait); |
|
register_reboot_notifier(&reboot); |
|
|
|
bcache_major = register_blkdev(0, "bcache"); |
|
if (bcache_major < 0) { |
|
unregister_reboot_notifier(&reboot); |
|
mutex_destroy(&bch_register_lock); |
|
return bcache_major; |
|
} |
|
|
|
if (bch_btree_init()) |
|
goto err; |
|
|
|
bcache_wq = alloc_workqueue("bcache", WQ_MEM_RECLAIM, 0); |
|
if (!bcache_wq) |
|
goto err; |
|
|
|
/* |
|
* Let's not make this `WQ_MEM_RECLAIM` for the following reasons: |
|
* |
|
* 1. It used `system_wq` before which also does no memory reclaim. |
|
* 2. With `WQ_MEM_RECLAIM` desktop stalls, increased boot times, and |
|
* reduced throughput can be observed. |
|
* |
|
* We still want to user our own queue to not congest the `system_wq`. |
|
*/ |
|
bch_flush_wq = alloc_workqueue("bch_flush", 0, 0); |
|
if (!bch_flush_wq) |
|
goto err; |
|
|
|
bch_journal_wq = alloc_workqueue("bch_journal", WQ_MEM_RECLAIM, 0); |
|
if (!bch_journal_wq) |
|
goto err; |
|
|
|
bcache_kobj = kobject_create_and_add("bcache", fs_kobj); |
|
if (!bcache_kobj) |
|
goto err; |
|
|
|
if (bch_request_init() || |
|
sysfs_create_files(bcache_kobj, files)) |
|
goto err; |
|
|
|
bch_debug_init(); |
|
closure_debug_init(); |
|
|
|
bcache_is_reboot = false; |
|
|
|
return 0; |
|
err: |
|
bcache_exit(); |
|
return -ENOMEM; |
|
} |
|
|
|
/* |
|
* Module hooks |
|
*/ |
|
module_exit(bcache_exit); |
|
module_init(bcache_init); |
|
|
|
module_param(bch_cutoff_writeback, uint, 0); |
|
MODULE_PARM_DESC(bch_cutoff_writeback, "threshold to cutoff writeback"); |
|
|
|
module_param(bch_cutoff_writeback_sync, uint, 0); |
|
MODULE_PARM_DESC(bch_cutoff_writeback_sync, "hard threshold to cutoff writeback"); |
|
|
|
MODULE_DESCRIPTION("Bcache: a Linux block layer cache"); |
|
MODULE_AUTHOR("Kent Overstreet <[email protected]>"); |
|
MODULE_LICENSE("GPL");
|
|
|