/* 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "bcachefs_format.h" #include "errcode.h" #include "fifo.h" #include "nocow_locking_types.h" #include "opts.h" #include "recovery_passes_types.h" #include "sb-errors_types.h" #include "seqmutex.h" #include "time_stats.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 count_event(_c, _name) this_cpu_inc((_c)->counters[BCH_COUNTER_##_name]) #define trace_and_count(_c, _name, ...) \ do { \ count_event(_c, _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") __printf(2, 3) void bch2_print_opts(struct bch_opts *, const char *, ...); __printf(2, 3) void __bch2_print(struct bch_fs *c, const char *fmt, ...); #define maybe_dev_to_fs(_c) _Generic((_c), \ struct bch_dev *: ((struct bch_dev *) (_c))->fs, \ struct bch_fs *: (_c)) #define bch2_print(_c, ...) __bch2_print(maybe_dev_to_fs(_c), __VA_ARGS__) #define bch2_print_ratelimited(_c, ...) \ do { \ static DEFINE_RATELIMIT_STATE(_rs, \ DEFAULT_RATELIMIT_INTERVAL, \ DEFAULT_RATELIMIT_BURST); \ \ if (__ratelimit(&_rs)) \ bch2_print(_c, __VA_ARGS__); \ } while (0) #define bch_info(c, fmt, ...) \ bch2_print(c, KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_notice(c, fmt, ...) \ bch2_print(c, KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_warn(c, fmt, ...) \ bch2_print(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_warn_ratelimited(c, fmt, ...) \ bch2_print_ratelimited(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_err(c, fmt, ...) \ bch2_print(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_err_dev(ca, fmt, ...) \ bch2_print(c, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) #define bch_err_dev_offset(ca, _offset, fmt, ...) \ bch2_print(c, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) #define bch_err_inum(c, _inum, fmt, ...) \ bch2_print(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \ bch2_print(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) #define bch_err_ratelimited(c, fmt, ...) \ bch2_print_ratelimited(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) #define bch_err_dev_ratelimited(ca, fmt, ...) \ bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \ bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \ bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \ bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) static inline bool should_print_err(int err) { return err && !bch2_err_matches(err, BCH_ERR_transaction_restart); } #define bch_err_fn(_c, _ret) \ do { \ if (should_print_err(_ret)) \ bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ } while (0) #define bch_err_fn_ratelimited(_c, _ret) \ do { \ if (should_print_err(_ret)) \ bch_err_ratelimited(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ } while (0) #define bch_err_msg(_c, _ret, _msg, ...) \ do { \ if (should_print_err(_ret)) \ 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_node_merging_disabled, \ "Disables merging of btree nodes") \ 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_node_read_done) \ 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_low_on_space) \ x(blocked_journal_low_on_pin) \ x(blocked_journal_max_in_flight) \ x(blocked_allocate) \ x(blocked_allocate_open_bucket) \ x(blocked_write_buffer_full) \ 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_node_scan_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" #include "thread_with_file_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_BTREE_subvolume_children, 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_quantiles io_latency[2]; #define CONGESTED_MAX 1024 atomic_t congested; u64 congested_last; struct io_count __percpu *io_done; }; /* * initial_gc_unfixed * error * topology error */ #define BCH_FS_FLAGS() \ x(new_fs) \ x(started) \ x(may_go_rw) \ x(rw) \ x(was_rw) \ x(stopping) \ x(emergency_ro) \ x(going_ro) \ x(write_disable_complete) \ x(clean_shutdown) \ x(fsck_running) \ x(initial_gc_unfixed) \ x(need_another_gc) \ x(need_delete_dead_snapshots) \ x(error) \ x(topology_error) \ x(errors_fixed) \ x(errors_not_fixed) enum bch_fs_flags { #define x(n) BCH_FS_##n, BCH_FS_FLAGS() #undef x }; struct btree_debug { unsigned id; }; #define BCH_TRANSACTIONS_NR 128 struct btree_transaction_stats { struct bch2_time_stats duration; struct bch2_time_stats lock_hold_times; struct mutex lock; unsigned nr_max_paths; unsigned journal_entries_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 { /* must match layout in darray_types.h */ size_t nr, size; 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; } *data; /* * 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; 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(fsync) \ x(dio_write) \ x(discard) \ x(discard_fast) \ x(invalidate) \ x(delete_dead_snapshots) \ x(snapshot_delete_pagecache) \ x(sysfs) \ x(btree_write_buffer) 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]; struct stdio_redirect *stdio; struct task_struct *stdio_filter; /* 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 /* * Analagous to c->writes, for asynchronous ops that don't necessarily * need fs to be read-write */ refcount_t ro_ref; wait_queue_head_t ro_ref_wait; 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)]; u64 btrees_lost_data; } 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; 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 workqueue_struct *btree_node_rewrite_worker; 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; 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 invalidate_work; struct work_struct discard_work; struct mutex discard_buckets_in_flight_lock; DARRAY(struct bpos) discard_buckets_in_flight; struct work_struct discard_fast_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; /* * Two different uses: * "Has this fsck pass?" - i.e. should this type of error be an * emergency read-only * And, in certain situations fsck will rewind to an earlier pass: used * for signaling to the toplevel code which pass we want to run now. */ enum bch_recovery_pass curr_recovery_pass; /* bitmap of explicitly enabled recovery passes: */ u64 recovery_passes_explicit; /* bitmask of recovery passes that we actually ran */ u64 recovery_passes_complete; /* never rewinds version of curr_recovery_pass */ enum bch_recovery_pass recovery_pass_done; struct semaphore online_fsck_mutex; /* 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; struct find_btree_nodes found_btree_nodes; 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(&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 bool bch2_ro_ref_tryget(struct bch_fs *c) { if (test_bit(BCH_FS_stopping, &c->flags)) return false; return refcount_inc_not_zero(&c->ro_ref); } static inline void bch2_ro_ref_put(struct bch_fs *c) { if (refcount_dec_and_test(&c->ro_ref)) wake_up(&c->ro_ref_wait); } 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 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]; } static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c) { struct stdio_redirect *stdio = c->stdio; if (c->stdio_filter && c->stdio_filter != current) stdio = NULL; return stdio; } static inline unsigned metadata_replicas_required(struct bch_fs *c) { return min(c->opts.metadata_replicas, c->opts.metadata_replicas_required); } static inline unsigned data_replicas_required(struct bch_fs *c) { return min(c->opts.data_replicas, c->opts.data_replicas_required); } #define BKEY_PADDED_ONSTACK(key, pad) \ struct { struct bkey_i key; __u64 key ## _pad[pad]; } #endif /* _BCACHEFS_H */