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| -rw-r--r-- | fs/bcachefs/bcachefs.h | 1164 |
1 files changed, 1164 insertions, 0 deletions
diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h new file mode 100644 index 0000000000..b62737fdf5 --- /dev/null +++ b/fs/bcachefs/bcachefs.h @@ -0,0 +1,1164 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHEFS_H +#define _BCACHEFS_H + +/* + * SOME HIGH LEVEL CODE DOCUMENTATION: + * + * Bcache mostly works with cache sets, cache devices, and backing devices. + * + * Support for multiple cache devices hasn't quite been finished off yet, but + * it's about 95% plumbed through. A cache set and its cache devices is sort of + * like a md raid array and its component devices. Most of the code doesn't care + * about individual cache devices, the main abstraction is the cache set. + * + * Multiple cache devices is intended to give us the ability to mirror dirty + * cached data and metadata, without mirroring clean cached data. + * + * Backing devices are different, in that they have a lifetime independent of a + * cache set. When you register a newly formatted backing device it'll come up + * in passthrough mode, and then you can attach and detach a backing device from + * a cache set at runtime - while it's mounted and in use. Detaching implicitly + * invalidates any cached data for that backing device. + * + * A cache set can have multiple (many) backing devices attached to it. + * + * There's also flash only volumes - this is the reason for the distinction + * between struct cached_dev and struct bcache_device. A flash only volume + * works much like a bcache device that has a backing device, except the + * "cached" data is always dirty. The end result is that we get thin + * provisioning with very little additional code. + * + * Flash only volumes work but they're not production ready because the moving + * garbage collector needs more work. More on that later. + * + * BUCKETS/ALLOCATION: + * + * Bcache is primarily designed for caching, which means that in normal + * operation all of our available space will be allocated. Thus, we need an + * efficient way of deleting things from the cache so we can write new things to + * it. + * + * To do this, we first divide the cache device up into buckets. A bucket is the + * unit of allocation; they're typically around 1 mb - anywhere from 128k to 2M+ + * works efficiently. + * + * Each bucket has a 16 bit priority, and an 8 bit generation associated with + * it. The gens and priorities for all the buckets are stored contiguously and + * packed on disk (in a linked list of buckets - aside from the superblock, all + * of bcache's metadata is stored in buckets). + * + * The priority is used to implement an LRU. We reset a bucket's priority when + * we allocate it or on cache it, and every so often we decrement the priority + * of each bucket. It could be used to implement something more sophisticated, + * if anyone ever gets around to it. + * + * The generation is used for invalidating buckets. Each pointer also has an 8 + * bit generation embedded in it; for a pointer to be considered valid, its gen + * must match the gen of the bucket it points into. Thus, to reuse a bucket all + * we have to do is increment its gen (and write its new gen to disk; we batch + * this up). + * + * Bcache is entirely COW - we never write twice to a bucket, even buckets that + * contain metadata (including btree nodes). + * + * THE BTREE: + * + * Bcache is in large part design around the btree. + * + * At a high level, the btree is just an index of key -> ptr tuples. + * + * Keys represent extents, and thus have a size field. Keys also have a variable + * number of pointers attached to them (potentially zero, which is handy for + * invalidating the cache). + * + * The key itself is an inode:offset pair. The inode number corresponds to a + * backing device or a flash only volume. The offset is the ending offset of the + * extent within the inode - not the starting offset; this makes lookups + * slightly more convenient. + * + * Pointers contain the cache device id, the offset on that device, and an 8 bit + * generation number. More on the gen later. + * + * Index lookups are not fully abstracted - cache lookups in particular are + * still somewhat mixed in with the btree code, but things are headed in that + * direction. + * + * Updates are fairly well abstracted, though. There are two different ways of + * updating the btree; insert and replace. + * + * BTREE_INSERT will just take a list of keys and insert them into the btree - + * overwriting (possibly only partially) any extents they overlap with. This is + * used to update the index after a write. + * + * BTREE_REPLACE is really cmpxchg(); it inserts a key into the btree iff it is + * overwriting a key that matches another given key. This is used for inserting + * data into the cache after a cache miss, and for background writeback, and for + * the moving garbage collector. + * + * There is no "delete" operation; deleting things from the index is + * accomplished by either by invalidating pointers (by incrementing a bucket's + * gen) or by inserting a key with 0 pointers - which will overwrite anything + * previously present at that location in the index. + * + * This means that there are always stale/invalid keys in the btree. They're + * filtered out by the code that iterates through a btree node, and removed when + * a btree node is rewritten. + * + * BTREE NODES: + * + * Our unit of allocation is a bucket, and we can't arbitrarily allocate and + * free smaller than a bucket - so, that's how big our btree nodes are. + * + * (If buckets are really big we'll only use part of the bucket for a btree node + * - no less than 1/4th - but a bucket still contains no more than a single + * btree node. I'd actually like to change this, but for now we rely on the + * bucket's gen for deleting btree nodes when we rewrite/split a node.) + * + * Anyways, btree nodes are big - big enough to be inefficient with a textbook + * btree implementation. + * + * The way this is solved is that btree nodes are internally log structured; we + * can append new keys to an existing btree node without rewriting it. This + * means each set of keys we write is sorted, but the node is not. + * + * We maintain this log structure in memory - keeping 1Mb of keys sorted would + * be expensive, and we have to distinguish between the keys we have written and + * the keys we haven't. So to do a lookup in a btree node, we have to search + * each sorted set. But we do merge written sets together lazily, so the cost of + * these extra searches is quite low (normally most of the keys in a btree node + * will be in one big set, and then there'll be one or two sets that are much + * smaller). + * + * This log structure makes bcache's btree more of a hybrid between a + * conventional btree and a compacting data structure, with some of the + * advantages of both. + * + * GARBAGE COLLECTION: + * + * We can't just invalidate any bucket - it might contain dirty data or + * metadata. If it once contained dirty data, other writes might overwrite it + * later, leaving no valid pointers into that bucket in the index. + * + * Thus, the primary purpose of garbage collection is to find buckets to reuse. + * It also counts how much valid data it each bucket currently contains, so that + * allocation can reuse buckets sooner when they've been mostly overwritten. + * + * It also does some things that are really internal to the btree + * implementation. If a btree node contains pointers that are stale by more than + * some threshold, it rewrites the btree node to avoid the bucket's generation + * wrapping around. It also merges adjacent btree nodes if they're empty enough. + * + * THE JOURNAL: + * + * Bcache's journal is not necessary for consistency; we always strictly + * order metadata writes so that the btree and everything else is consistent on + * disk in the event of an unclean shutdown, and in fact bcache had writeback + * caching (with recovery from unclean shutdown) before journalling was + * implemented. + * + * Rather, the journal is purely a performance optimization; we can't complete a + * write until we've updated the index on disk, otherwise the cache would be + * inconsistent in the event of an unclean shutdown. This means that without the + * journal, on random write workloads we constantly have to update all the leaf + * nodes in the btree, and those writes will be mostly empty (appending at most + * a few keys each) - highly inefficient in terms of amount of metadata writes, + * and it puts more strain on the various btree resorting/compacting code. + * + * The journal is just a log of keys we've inserted; on startup we just reinsert + * all the keys in the open journal entries. That means that when we're updating + * a node in the btree, we can wait until a 4k block of keys fills up before + * writing them out. + * + * For simplicity, we only journal updates to leaf nodes; updates to parent + * nodes are rare enough (since our leaf nodes are huge) that it wasn't worth + * the complexity to deal with journalling them (in particular, journal replay) + * - updates to non leaf nodes just happen synchronously (see btree_split()). + */ + +#undef pr_fmt +#ifdef __KERNEL__ +#define pr_fmt(fmt) "bcachefs: %s() " fmt "\n", __func__ +#else +#define pr_fmt(fmt) "%s() " fmt "\n", __func__ +#endif + +#include <linux/backing-dev-defs.h> +#include <linux/bug.h> +#include <linux/bio.h> +#include <linux/closure.h> +#include <linux/kobject.h> +#include <linux/list.h> +#include <linux/math64.h> +#include <linux/mutex.h> +#include <linux/percpu-refcount.h> +#include <linux/percpu-rwsem.h> +#include <linux/rhashtable.h> +#include <linux/rwsem.h> +#include <linux/semaphore.h> +#include <linux/seqlock.h> +#include <linux/shrinker.h> +#include <linux/srcu.h> +#include <linux/types.h> +#include <linux/workqueue.h> +#include <linux/zstd.h> + +#include "bcachefs_format.h" +#include "errcode.h" +#include "fifo.h" +#include "nocow_locking_types.h" +#include "opts.h" +#include "recovery_types.h" +#include "sb-errors_types.h" +#include "seqmutex.h" +#include "util.h" + +#ifdef CONFIG_BCACHEFS_DEBUG +#define BCH_WRITE_REF_DEBUG +#endif + +#ifndef dynamic_fault +#define dynamic_fault(...) 0 +#endif + +#define race_fault(...) dynamic_fault("bcachefs:race") + +#define trace_and_count(_c, _name, ...) \ +do { \ + this_cpu_inc((_c)->counters[BCH_COUNTER_##_name]); \ + trace_##_name(__VA_ARGS__); \ +} while (0) + +#define bch2_fs_init_fault(name) \ + dynamic_fault("bcachefs:bch_fs_init:" name) +#define bch2_meta_read_fault(name) \ + dynamic_fault("bcachefs:meta:read:" name) +#define bch2_meta_write_fault(name) \ + dynamic_fault("bcachefs:meta:write:" name) + +#ifdef __KERNEL__ +#define BCACHEFS_LOG_PREFIX +#endif + +#ifdef BCACHEFS_LOG_PREFIX + +#define bch2_log_msg(_c, fmt) "bcachefs (%s): " fmt, ((_c)->name) +#define bch2_fmt_dev(_ca, fmt) "bcachefs (%s): " fmt "\n", ((_ca)->name) +#define bch2_fmt_dev_offset(_ca, _offset, fmt) "bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset) +#define bch2_fmt_inum(_c, _inum, fmt) "bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum) +#define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ + "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset) + +#else + +#define bch2_log_msg(_c, fmt) fmt +#define bch2_fmt_dev(_ca, fmt) "%s: " fmt "\n", ((_ca)->name) +#define bch2_fmt_dev_offset(_ca, _offset, fmt) "%s sector %llu: " fmt "\n", ((_ca)->name), (_offset) +#define bch2_fmt_inum(_c, _inum, fmt) "inum %llu: " fmt "\n", (_inum) +#define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ + "inum %llu offset %llu: " fmt "\n", (_inum), (_offset) + +#endif + +#define bch2_fmt(_c, fmt) bch2_log_msg(_c, fmt "\n") + +#define bch_info(c, fmt, ...) \ + printk(KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__) +#define bch_notice(c, fmt, ...) \ + printk(KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__) +#define bch_warn(c, fmt, ...) \ + printk(KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) +#define bch_warn_ratelimited(c, fmt, ...) \ + printk_ratelimited(KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) + +#define bch_err(c, fmt, ...) \ + printk(KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) +#define bch_err_dev(ca, fmt, ...) \ + printk(KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) +#define bch_err_dev_offset(ca, _offset, fmt, ...) \ + printk(KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) +#define bch_err_inum(c, _inum, fmt, ...) \ + printk(KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) +#define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \ + printk(KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) + +#define bch_err_ratelimited(c, fmt, ...) \ + printk_ratelimited(KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) +#define bch_err_dev_ratelimited(ca, fmt, ...) \ + printk_ratelimited(KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) +#define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \ + printk_ratelimited(KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) +#define bch_err_inum_ratelimited(c, _inum, fmt, ...) \ + printk_ratelimited(KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) +#define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \ + printk_ratelimited(KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) + +#define bch_err_fn(_c, _ret) \ +do { \ + if (_ret && !bch2_err_matches(_ret, BCH_ERR_transaction_restart))\ + bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ +} while (0) + +#define bch_err_msg(_c, _ret, _msg, ...) \ +do { \ + if (_ret && !bch2_err_matches(_ret, BCH_ERR_transaction_restart))\ + bch_err(_c, "%s(): error " _msg " %s", __func__, \ + ##__VA_ARGS__, bch2_err_str(_ret)); \ +} while (0) + +#define bch_verbose(c, fmt, ...) \ +do { \ + if ((c)->opts.verbose) \ + bch_info(c, fmt, ##__VA_ARGS__); \ +} while (0) + +#define pr_verbose_init(opts, fmt, ...) \ +do { \ + if (opt_get(opts, verbose)) \ + pr_info(fmt, ##__VA_ARGS__); \ +} while (0) + +/* Parameters that are useful for debugging, but should always be compiled in: */ +#define BCH_DEBUG_PARAMS_ALWAYS() \ + BCH_DEBUG_PARAM(key_merging_disabled, \ + "Disables merging of extents") \ + BCH_DEBUG_PARAM(btree_gc_always_rewrite, \ + "Causes mark and sweep to compact and rewrite every " \ + "btree node it traverses") \ + BCH_DEBUG_PARAM(btree_gc_rewrite_disabled, \ + "Disables rewriting of btree nodes during mark and sweep")\ + BCH_DEBUG_PARAM(btree_shrinker_disabled, \ + "Disables the shrinker callback for the btree node cache")\ + BCH_DEBUG_PARAM(verify_btree_ondisk, \ + "Reread btree nodes at various points to verify the " \ + "mergesort in the read path against modifications " \ + "done in memory") \ + BCH_DEBUG_PARAM(verify_all_btree_replicas, \ + "When reading btree nodes, read all replicas and " \ + "compare them") \ + BCH_DEBUG_PARAM(backpointers_no_use_write_buffer, \ + "Don't use the write buffer for backpointers, enabling "\ + "extra runtime checks") + +/* Parameters that should only be compiled in debug mode: */ +#define BCH_DEBUG_PARAMS_DEBUG() \ + BCH_DEBUG_PARAM(expensive_debug_checks, \ + "Enables various runtime debugging checks that " \ + "significantly affect performance") \ + BCH_DEBUG_PARAM(debug_check_iterators, \ + "Enables extra verification for btree iterators") \ + BCH_DEBUG_PARAM(debug_check_btree_accounting, \ + "Verify btree accounting for keys within a node") \ + BCH_DEBUG_PARAM(journal_seq_verify, \ + "Store the journal sequence number in the version " \ + "number of every btree key, and verify that btree " \ + "update ordering is preserved during recovery") \ + BCH_DEBUG_PARAM(inject_invalid_keys, \ + "Store the journal sequence number in the version " \ + "number of every btree key, and verify that btree " \ + "update ordering is preserved during recovery") \ + BCH_DEBUG_PARAM(test_alloc_startup, \ + "Force allocator startup to use the slowpath where it" \ + "can't find enough free buckets without invalidating" \ + "cached data") \ + BCH_DEBUG_PARAM(force_reconstruct_read, \ + "Force reads to use the reconstruct path, when reading" \ + "from erasure coded extents") \ + BCH_DEBUG_PARAM(test_restart_gc, \ + "Test restarting mark and sweep gc when bucket gens change") + +#define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG() + +#ifdef CONFIG_BCACHEFS_DEBUG +#define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL() +#else +#define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS() +#endif + +#define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name; +BCH_DEBUG_PARAMS() +#undef BCH_DEBUG_PARAM + +#ifndef CONFIG_BCACHEFS_DEBUG +#define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name; +BCH_DEBUG_PARAMS_DEBUG() +#undef BCH_DEBUG_PARAM +#endif + +#define BCH_TIME_STATS() \ + x(btree_node_mem_alloc) \ + x(btree_node_split) \ + x(btree_node_compact) \ + x(btree_node_merge) \ + x(btree_node_sort) \ + x(btree_node_read) \ + x(btree_interior_update_foreground) \ + x(btree_interior_update_total) \ + x(btree_gc) \ + x(data_write) \ + x(data_read) \ + x(data_promote) \ + x(journal_flush_write) \ + x(journal_noflush_write) \ + x(journal_flush_seq) \ + x(blocked_journal) \ + x(blocked_allocate) \ + x(blocked_allocate_open_bucket) \ + x(nocow_lock_contended) + +enum bch_time_stats { +#define x(name) BCH_TIME_##name, + BCH_TIME_STATS() +#undef x + BCH_TIME_STAT_NR +}; + +#include "alloc_types.h" +#include "btree_types.h" +#include "btree_write_buffer_types.h" +#include "buckets_types.h" +#include "buckets_waiting_for_journal_types.h" +#include "clock_types.h" +#include "disk_groups_types.h" +#include "ec_types.h" +#include "journal_types.h" +#include "keylist_types.h" +#include "quota_types.h" +#include "rebalance_types.h" +#include "replicas_types.h" +#include "subvolume_types.h" +#include "super_types.h" + +/* Number of nodes btree coalesce will try to coalesce at once */ +#define GC_MERGE_NODES 4U + +/* Maximum number of nodes we might need to allocate atomically: */ +#define BTREE_RESERVE_MAX (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1)) + +/* Size of the freelist we allocate btree nodes from: */ +#define BTREE_NODE_RESERVE (BTREE_RESERVE_MAX * 4) + +#define BTREE_NODE_OPEN_BUCKET_RESERVE (BTREE_RESERVE_MAX * BCH_REPLICAS_MAX) + +struct btree; + +enum gc_phase { + GC_PHASE_NOT_RUNNING, + GC_PHASE_START, + GC_PHASE_SB, + + GC_PHASE_BTREE_stripes, + GC_PHASE_BTREE_extents, + GC_PHASE_BTREE_inodes, + GC_PHASE_BTREE_dirents, + GC_PHASE_BTREE_xattrs, + GC_PHASE_BTREE_alloc, + GC_PHASE_BTREE_quotas, + GC_PHASE_BTREE_reflink, + GC_PHASE_BTREE_subvolumes, + GC_PHASE_BTREE_snapshots, + GC_PHASE_BTREE_lru, + GC_PHASE_BTREE_freespace, + GC_PHASE_BTREE_need_discard, + GC_PHASE_BTREE_backpointers, + GC_PHASE_BTREE_bucket_gens, + GC_PHASE_BTREE_snapshot_trees, + GC_PHASE_BTREE_deleted_inodes, + GC_PHASE_BTREE_logged_ops, + GC_PHASE_BTREE_rebalance_work, + + GC_PHASE_PENDING_DELETE, +}; + +struct gc_pos { + enum gc_phase phase; + struct bpos pos; + unsigned level; +}; + +struct reflink_gc { + u64 offset; + u32 size; + u32 refcount; +}; + +typedef GENRADIX(struct reflink_gc) reflink_gc_table; + +struct io_count { + u64 sectors[2][BCH_DATA_NR]; +}; + +struct bch_dev { + struct kobject kobj; + struct percpu_ref ref; + struct completion ref_completion; + struct percpu_ref io_ref; + struct completion io_ref_completion; + + struct bch_fs *fs; + + u8 dev_idx; + /* + * Cached version of this device's member info from superblock + * Committed by bch2_write_super() -> bch_fs_mi_update() + */ + struct bch_member_cpu mi; + atomic64_t errors[BCH_MEMBER_ERROR_NR]; + + __uuid_t uuid; + char name[BDEVNAME_SIZE]; + + struct bch_sb_handle disk_sb; + struct bch_sb *sb_read_scratch; + int sb_write_error; + dev_t dev; + atomic_t flush_seq; + + struct bch_devs_mask self; + + /* biosets used in cloned bios for writing multiple replicas */ + struct bio_set replica_set; + + /* + * Buckets: + * Per-bucket arrays are protected by c->mark_lock, bucket_lock and + * gc_lock, for device resize - holding any is sufficient for access: + * Or rcu_read_lock(), but only for ptr_stale(): + */ + struct bucket_array __rcu *buckets_gc; + struct bucket_gens __rcu *bucket_gens; + u8 *oldest_gen; + unsigned long *buckets_nouse; + struct rw_semaphore bucket_lock; + + struct bch_dev_usage *usage_base; + struct bch_dev_usage __percpu *usage[JOURNAL_BUF_NR]; + struct bch_dev_usage __percpu *usage_gc; + + /* Allocator: */ + u64 new_fs_bucket_idx; + u64 alloc_cursor; + + unsigned nr_open_buckets; + unsigned nr_btree_reserve; + + size_t inc_gen_needs_gc; + size_t inc_gen_really_needs_gc; + size_t buckets_waiting_on_journal; + + atomic64_t rebalance_work; + + struct journal_device journal; + u64 prev_journal_sector; + + struct work_struct io_error_work; + + /* The rest of this all shows up in sysfs */ + atomic64_t cur_latency[2]; + struct bch2_time_stats io_latency[2]; + +#define CONGESTED_MAX 1024 + atomic_t congested; + u64 congested_last; + + struct io_count __percpu *io_done; +}; + +enum { + /* startup: */ + BCH_FS_STARTED, + BCH_FS_MAY_GO_RW, + BCH_FS_RW, + BCH_FS_WAS_RW, + + /* shutdown: */ + BCH_FS_STOPPING, + BCH_FS_EMERGENCY_RO, + BCH_FS_GOING_RO, + BCH_FS_WRITE_DISABLE_COMPLETE, + BCH_FS_CLEAN_SHUTDOWN, + + /* fsck passes: */ + BCH_FS_FSCK_DONE, + BCH_FS_INITIAL_GC_UNFIXED, /* kill when we enumerate fsck errors */ + BCH_FS_NEED_ANOTHER_GC, + + BCH_FS_NEED_DELETE_DEAD_SNAPSHOTS, + + /* errors: */ + BCH_FS_ERROR, + BCH_FS_TOPOLOGY_ERROR, + BCH_FS_ERRORS_FIXED, + BCH_FS_ERRORS_NOT_FIXED, +}; + +struct btree_debug { + unsigned id; +}; + +#define BCH_TRANSACTIONS_NR 128 + +struct btree_transaction_stats { + struct bch2_time_stats lock_hold_times; + struct mutex lock; + unsigned nr_max_paths; + unsigned wb_updates_size; + unsigned max_mem; + char *max_paths_text; +}; + +struct bch_fs_pcpu { + u64 sectors_available; +}; + +struct journal_seq_blacklist_table { + size_t nr; + struct journal_seq_blacklist_table_entry { + u64 start; + u64 end; + bool dirty; + } entries[]; +}; + +struct journal_keys { + struct journal_key { + u64 journal_seq; + u32 journal_offset; + enum btree_id btree_id:8; + unsigned level:8; + bool allocated; + bool overwritten; + struct bkey_i *k; + } *d; + /* + * Gap buffer: instead of all the empty space in the array being at the + * end of the buffer - from @nr to @size - the empty space is at @gap. + * This means that sequential insertions are O(n) instead of O(n^2). + */ + size_t gap; + size_t nr; + size_t size; + atomic_t ref; + bool initial_ref_held; +}; + +struct btree_trans_buf { + struct btree_trans *trans; +}; + +#define REPLICAS_DELTA_LIST_MAX (1U << 16) + +#define BCACHEFS_ROOT_SUBVOL_INUM \ + ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO }) + +#define BCH_WRITE_REFS() \ + x(trans) \ + x(write) \ + x(promote) \ + x(node_rewrite) \ + x(stripe_create) \ + x(stripe_delete) \ + x(reflink) \ + x(fallocate) \ + x(discard) \ + x(invalidate) \ + x(delete_dead_snapshots) \ + x(snapshot_delete_pagecache) \ + x(sysfs) + +enum bch_write_ref { +#define x(n) BCH_WRITE_REF_##n, + BCH_WRITE_REFS() +#undef x + BCH_WRITE_REF_NR, +}; + +struct bch_fs { + struct closure cl; + + struct list_head list; + struct kobject kobj; + struct kobject counters_kobj; + struct kobject internal; + struct kobject opts_dir; + struct kobject time_stats; + unsigned long flags; + + int minor; + struct device *chardev; + struct super_block *vfs_sb; + dev_t dev; + char name[40]; + + /* ro/rw, add/remove/resize devices: */ + struct rw_semaphore state_lock; + + /* Counts outstanding writes, for clean transition to read-only */ +#ifdef BCH_WRITE_REF_DEBUG + atomic_long_t writes[BCH_WRITE_REF_NR]; +#else + struct percpu_ref writes; +#endif + struct work_struct read_only_work; + + struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX]; + + struct bch_replicas_cpu replicas; + struct bch_replicas_cpu replicas_gc; + struct mutex replicas_gc_lock; + mempool_t replicas_delta_pool; + + struct journal_entry_res btree_root_journal_res; + struct journal_entry_res replicas_journal_res; + struct journal_entry_res clock_journal_res; + struct journal_entry_res dev_usage_journal_res; + + struct bch_disk_groups_cpu __rcu *disk_groups; + + struct bch_opts opts; + + /* Updated by bch2_sb_update():*/ + struct { + __uuid_t uuid; + __uuid_t user_uuid; + + u16 version; + u16 version_min; + u16 version_upgrade_complete; + + u8 nr_devices; + u8 clean; + + u8 encryption_type; + + u64 time_base_lo; + u32 time_base_hi; + unsigned time_units_per_sec; + unsigned nsec_per_time_unit; + u64 features; + u64 compat; + unsigned long errors_silent[BITS_TO_LONGS(BCH_SB_ERR_MAX)]; + } sb; + + + struct bch_sb_handle disk_sb; + + unsigned short block_bits; /* ilog2(block_size) */ + + u16 btree_foreground_merge_threshold; + + struct closure sb_write; + struct mutex sb_lock; + + /* snapshot.c: */ + struct snapshot_table __rcu *snapshots; + size_t snapshot_table_size; + struct mutex snapshot_table_lock; + struct rw_semaphore snapshot_create_lock; + + struct work_struct snapshot_delete_work; + struct work_struct snapshot_wait_for_pagecache_and_delete_work; + snapshot_id_list snapshots_unlinked; + struct mutex snapshots_unlinked_lock; + + /* BTREE CACHE */ + struct bio_set btree_bio; + struct workqueue_struct *io_complete_wq; + + struct btree_root btree_roots_known[BTREE_ID_NR]; + DARRAY(struct btree_root) btree_roots_extra; + struct mutex btree_root_lock; + + struct btree_cache btree_cache; + + /* + * Cache of allocated btree nodes - if we allocate a btree node and + * don't use it, if we free it that space can't be reused until going + * _all_ the way through the allocator (which exposes us to a livelock + * when allocating btree reserves fail halfway through) - instead, we + * can stick them here: + */ + struct btree_alloc btree_reserve_cache[BTREE_NODE_RESERVE * 2]; + unsigned btree_reserve_cache_nr; + struct mutex btree_reserve_cache_lock; + + mempool_t btree_interior_update_pool; + struct list_head btree_interior_update_list; + struct list_head btree_interior_updates_unwritten; + struct mutex btree_interior_update_lock; + struct closure_waitlist btree_interior_update_wait; + + struct workqueue_struct *btree_interior_update_worker; + struct work_struct btree_interior_update_work; + + struct list_head pending_node_rewrites; + struct mutex pending_node_rewrites_lock; + + /* btree_io.c: */ + spinlock_t btree_write_error_lock; + struct btree_write_stats { + atomic64_t nr; + atomic64_t bytes; + } btree_write_stats[BTREE_WRITE_TYPE_NR]; + + /* btree_iter.c: */ + struct seqmutex btree_trans_lock; + struct list_head btree_trans_list; + mempool_t btree_trans_pool; + mempool_t btree_trans_mem_pool; + struct btree_trans_buf __percpu *btree_trans_bufs; + + struct srcu_struct btree_trans_barrier; + bool btree_trans_barrier_initialized; + + struct btree_key_cache btree_key_cache; + unsigned btree_key_cache_btrees; + + struct btree_write_buffer btree_write_buffer; + + struct workqueue_struct *btree_update_wq; + struct workqueue_struct *btree_io_complete_wq; + /* copygc needs its own workqueue for index updates.. */ + struct workqueue_struct *copygc_wq; + /* + * Use a dedicated wq for write ref holder tasks. Required to avoid + * dependency problems with other wq tasks that can block on ref + * draining, such as read-only transition. + */ + struct workqueue_struct *write_ref_wq; + + /* ALLOCATION */ + struct bch_devs_mask rw_devs[BCH_DATA_NR]; + + u64 capacity; /* sectors */ + + /* + * When capacity _decreases_ (due to a disk being removed), we + * increment capacity_gen - this invalidates outstanding reservations + * and forces them to be revalidated + */ + u32 capacity_gen; + unsigned bucket_size_max; + + atomic64_t sectors_available; + struct mutex sectors_available_lock; + + struct bch_fs_pcpu __percpu *pcpu; + + struct percpu_rw_semaphore mark_lock; + + seqcount_t usage_lock; + struct bch_fs_usage *usage_base; + struct bch_fs_usage __percpu *usage[JOURNAL_BUF_NR]; + struct bch_fs_usage __percpu *usage_gc; + u64 __percpu *online_reserved; + + /* single element mempool: */ + struct mutex usage_scratch_lock; + struct bch_fs_usage_online *usage_scratch; + + struct io_clock io_clock[2]; + + /* JOURNAL SEQ BLACKLIST */ + struct journal_seq_blacklist_table * + journal_seq_blacklist_table; + struct work_struct journal_seq_blacklist_gc_work; + + /* ALLOCATOR */ + spinlock_t freelist_lock; + struct closure_waitlist freelist_wait; + u64 blocked_allocate; + u64 blocked_allocate_open_bucket; + + open_bucket_idx_t open_buckets_freelist; + open_bucket_idx_t open_buckets_nr_free; + struct closure_waitlist open_buckets_wait; + struct open_bucket open_buckets[OPEN_BUCKETS_COUNT]; + open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT]; + + open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT]; + open_bucket_idx_t open_buckets_partial_nr; + + struct write_point btree_write_point; + struct write_point rebalance_write_point; + + struct write_point write_points[WRITE_POINT_MAX]; + struct hlist_head write_points_hash[WRITE_POINT_HASH_NR]; + struct mutex write_points_hash_lock; + unsigned write_points_nr; + + struct buckets_waiting_for_journal buckets_waiting_for_journal; + struct work_struct discard_work; + struct work_struct invalidate_work; + + /* GARBAGE COLLECTION */ + struct task_struct *gc_thread; + atomic_t kick_gc; + unsigned long gc_count; + + enum btree_id gc_gens_btree; + struct bpos gc_gens_pos; + + /* + * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos] + * has been marked by GC. + * + * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.) + * + * Protected by gc_pos_lock. Only written to by GC thread, so GC thread + * can read without a lock. + */ + seqcount_t gc_pos_lock; + struct gc_pos gc_pos; + + /* + * The allocation code needs gc_mark in struct bucket to be correct, but + * it's not while a gc is in progress. + */ + struct rw_semaphore gc_lock; + struct mutex gc_gens_lock; + + /* IO PATH */ + struct semaphore io_in_flight; + struct bio_set bio_read; + struct bio_set bio_read_split; + struct bio_set bio_write; + struct mutex bio_bounce_pages_lock; + mempool_t bio_bounce_pages; + struct bucket_nocow_lock_table + nocow_locks; + struct rhashtable promote_table; + + mempool_t compression_bounce[2]; + mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR]; + mempool_t decompress_workspace; + size_t zstd_workspace_size; + + struct crypto_shash *sha256; + struct crypto_sync_skcipher *chacha20; + struct crypto_shash *poly1305; + + atomic64_t key_version; + + mempool_t large_bkey_pool; + + /* MOVE.C */ + struct list_head moving_context_list; + struct mutex moving_context_lock; + + /* REBALANCE */ + struct bch_fs_rebalance rebalance; + + /* COPYGC */ + struct task_struct *copygc_thread; + struct write_point copygc_write_point; + s64 copygc_wait_at; + s64 copygc_wait; + bool copygc_running; + wait_queue_head_t copygc_running_wq; + + /* STRIPES: */ + GENRADIX(struct stripe) stripes; + GENRADIX(struct gc_stripe) gc_stripes; + + struct hlist_head ec_stripes_new[32]; + spinlock_t ec_stripes_new_lock; + + ec_stripes_heap ec_stripes_heap; + struct mutex ec_stripes_heap_lock; + + /* ERASURE CODING */ + struct list_head ec_stripe_head_list; + struct mutex ec_stripe_head_lock; + + struct list_head ec_stripe_new_list; + struct mutex ec_stripe_new_lock; + wait_queue_head_t ec_stripe_new_wait; + + struct work_struct ec_stripe_create_work; + u64 ec_stripe_hint; + + struct work_struct ec_stripe_delete_work; + + struct bio_set ec_bioset; + + /* REFLINK */ + reflink_gc_table reflink_gc_table; + size_t reflink_gc_nr; + + /* fs.c */ + struct list_head vfs_inodes_list; + struct mutex vfs_inodes_lock; + + /* VFS IO PATH - fs-io.c */ + struct bio_set writepage_bioset; + struct bio_set dio_write_bioset; + struct bio_set dio_read_bioset; + struct bio_set nocow_flush_bioset; + + /* QUOTAS */ + struct bch_memquota_type quotas[QTYP_NR]; + + /* RECOVERY */ + u64 journal_replay_seq_start; + u64 journal_replay_seq_end; + enum bch_recovery_pass curr_recovery_pass; + /* bitmap of explicitly enabled recovery passes: */ + u64 recovery_passes_explicit; + u64 recovery_passes_complete; + + /* DEBUG JUNK */ + struct dentry *fs_debug_dir; + struct dentry *btree_debug_dir; + struct btree_debug btree_debug[BTREE_ID_NR]; + struct btree *verify_data; + struct btree_node *verify_ondisk; + struct mutex verify_lock; + + u64 *unused_inode_hints; + unsigned inode_shard_bits; + + /* + * A btree node on disk could have too many bsets for an iterator to fit + * on the stack - have to dynamically allocate them + */ + mempool_t fill_iter; + + mempool_t btree_bounce_pool; + + struct journal journal; + GENRADIX(struct journal_replay *) journal_entries; + u64 journal_entries_base_seq; + struct journal_keys journal_keys; + struct list_head journal_iters; + + u64 last_bucket_seq_cleanup; + + u64 counters_on_mount[BCH_COUNTER_NR]; + u64 __percpu *counters; + + unsigned btree_gc_periodic:1; + unsigned copy_gc_enabled:1; + bool promote_whole_extents; + + struct bch2_time_stats times[BCH_TIME_STAT_NR]; + + struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR]; + + /* ERRORS */ + struct list_head fsck_error_msgs; + struct mutex fsck_error_msgs_lock; + bool fsck_alloc_msgs_err; + + bch_sb_errors_cpu fsck_error_counts; + struct mutex fsck_error_counts_lock; +}; + +extern struct wait_queue_head bch2_read_only_wait; + +static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref) +{ +#ifdef BCH_WRITE_REF_DEBUG + atomic_long_inc(&c->writes[ref]); +#else + percpu_ref_get(&c->writes); +#endif +} + +static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) +{ +#ifdef BCH_WRITE_REF_DEBUG + return !test_bit(BCH_FS_GOING_RO, &c->flags) && + atomic_long_inc_not_zero(&c->writes[ref]); +#else + return percpu_ref_tryget_live(&c->writes); +#endif +} + +static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref) +{ +#ifdef BCH_WRITE_REF_DEBUG + long v = atomic_long_dec_return(&c->writes[ref]); + + BUG_ON(v < 0); + if (v) + return; + for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) + if (atomic_long_read(&c->writes[i])) + return; + + set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags); + wake_up(&bch2_read_only_wait); +#else + percpu_ref_put(&c->writes); +#endif +} + +static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) +{ +#ifndef NO_BCACHEFS_FS + if (c->vfs_sb) + c->vfs_sb->s_bdi->ra_pages = ra_pages; +#endif +} + +static inline unsigned bucket_bytes(const struct bch_dev *ca) +{ + return ca->mi.bucket_size << 9; +} + +static inline unsigned block_bytes(const struct bch_fs *c) +{ + return c->opts.block_size; +} + +static inline unsigned block_sectors(const struct bch_fs *c) +{ + return c->opts.block_size >> 9; +} + +static inline size_t btree_sectors(const struct bch_fs *c) +{ + return c->opts.btree_node_size >> 9; +} + +static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree) +{ + return c->btree_key_cache_btrees & (1U << btree); +} + +static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time) +{ + struct timespec64 t; + s32 rem; + + time += c->sb.time_base_lo; + + t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem); + t.tv_nsec = rem * c->sb.nsec_per_time_unit; + return t; +} + +static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts) +{ + return (ts.tv_sec * c->sb.time_units_per_sec + + (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo; +} + +static inline s64 bch2_current_time(const struct bch_fs *c) +{ + struct timespec64 now; + + ktime_get_coarse_real_ts64(&now); + return timespec_to_bch2_time(c, now); +} + +static inline bool bch2_dev_exists2(const struct bch_fs *c, unsigned dev) +{ + return dev < c->sb.nr_devices && c->devs[dev]; +} + +#define BKEY_PADDED_ONSTACK(key, pad) \ + struct { struct bkey_i key; __u64 key ## _pad[pad]; } + +#endif /* _BCACHEFS_H */ |