--- /dev/null
+/* 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/refcount.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 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(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_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_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_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;
+};
+
+/*
+ * initial_gc_unfixed
+ * error
+ * topology error
+ */
+
+#define BCH_FS_FLAGS() \
+ 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 {
+ 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) \
+ 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)];
+ } 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;
+ /*
+ * 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;
+
+ 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 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];
+}
+
+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;
+}
+
+#define BKEY_PADDED_ONSTACK(key, pad) \
+ struct { struct bkey_i key; __u64 key ## _pad[pad]; }
+
+#endif /* _BCACHEFS_H */
projects / bcachefs-tools-debian / blobdiff