1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _BCACHEFS_H 3 #define _BCACHEFS_H 4 5 /* 6 * SOME HIGH LEVEL CODE DOCUMENTATION: 7 * 8 * Bcache mostly works with cache sets, cache devices, and backing devices. 9 * 10 * Support for multiple cache devices hasn't quite been finished off yet, but 11 * it's about 95% plumbed through. A cache set and its cache devices is sort of 12 * like a md raid array and its component devices. Most of the code doesn't care 13 * about individual cache devices, the main abstraction is the cache set. 14 * 15 * Multiple cache devices is intended to give us the ability to mirror dirty 16 * cached data and metadata, without mirroring clean cached data. 17 * 18 * Backing devices are different, in that they have a lifetime independent of a 19 * cache set. When you register a newly formatted backing device it'll come up 20 * in passthrough mode, and then you can attach and detach a backing device from 21 * a cache set at runtime - while it's mounted and in use. Detaching implicitly 22 * invalidates any cached data for that backing device. 23 * 24 * A cache set can have multiple (many) backing devices attached to it. 25 * 26 * There's also flash only volumes - this is the reason for the distinction 27 * between struct cached_dev and struct bcache_device. A flash only volume 28 * works much like a bcache device that has a backing device, except the 29 * "cached" data is always dirty. The end result is that we get thin 30 * provisioning with very little additional code. 31 * 32 * Flash only volumes work but they're not production ready because the moving 33 * garbage collector needs more work. More on that later. 34 * 35 * BUCKETS/ALLOCATION: 36 * 37 * Bcache is primarily designed for caching, which means that in normal 38 * operation all of our available space will be allocated. Thus, we need an 39 * efficient way of deleting things from the cache so we can write new things to 40 * it. 41 * 42 * To do this, we first divide the cache device up into buckets. A bucket is the 43 * unit of allocation; they're typically around 1 mb - anywhere from 128k to 2M+ 44 * works efficiently. 45 * 46 * Each bucket has a 16 bit priority, and an 8 bit generation associated with 47 * it. The gens and priorities for all the buckets are stored contiguously and 48 * packed on disk (in a linked list of buckets - aside from the superblock, all 49 * of bcache's metadata is stored in buckets). 50 * 51 * The priority is used to implement an LRU. We reset a bucket's priority when 52 * we allocate it or on cache it, and every so often we decrement the priority 53 * of each bucket. It could be used to implement something more sophisticated, 54 * if anyone ever gets around to it. 55 * 56 * The generation is used for invalidating buckets. Each pointer also has an 8 57 * bit generation embedded in it; for a pointer to be considered valid, its gen 58 * must match the gen of the bucket it points into. Thus, to reuse a bucket all 59 * we have to do is increment its gen (and write its new gen to disk; we batch 60 * this up). 61 * 62 * Bcache is entirely COW - we never write twice to a bucket, even buckets that 63 * contain metadata (including btree nodes). 64 * 65 * THE BTREE: 66 * 67 * Bcache is in large part design around the btree. 68 * 69 * At a high level, the btree is just an index of key -> ptr tuples. 70 * 71 * Keys represent extents, and thus have a size field. Keys also have a variable 72 * number of pointers attached to them (potentially zero, which is handy for 73 * invalidating the cache). 74 * 75 * The key itself is an inode:offset pair. The inode number corresponds to a 76 * backing device or a flash only volume. The offset is the ending offset of the 77 * extent within the inode - not the starting offset; this makes lookups 78 * slightly more convenient. 79 * 80 * Pointers contain the cache device id, the offset on that device, and an 8 bit 81 * generation number. More on the gen later. 82 * 83 * Index lookups are not fully abstracted - cache lookups in particular are 84 * still somewhat mixed in with the btree code, but things are headed in that 85 * direction. 86 * 87 * Updates are fairly well abstracted, though. There are two different ways of 88 * updating the btree; insert and replace. 89 * 90 * BTREE_INSERT will just take a list of keys and insert them into the btree - 91 * overwriting (possibly only partially) any extents they overlap with. This is 92 * used to update the index after a write. 93 * 94 * BTREE_REPLACE is really cmpxchg(); it inserts a key into the btree iff it is 95 * overwriting a key that matches another given key. This is used for inserting 96 * data into the cache after a cache miss, and for background writeback, and for 97 * the moving garbage collector. 98 * 99 * There is no "delete" operation; deleting things from the index is 100 * accomplished by either by invalidating pointers (by incrementing a bucket's 101 * gen) or by inserting a key with 0 pointers - which will overwrite anything 102 * previously present at that location in the index. 103 * 104 * This means that there are always stale/invalid keys in the btree. They're 105 * filtered out by the code that iterates through a btree node, and removed when 106 * a btree node is rewritten. 107 * 108 * BTREE NODES: 109 * 110 * Our unit of allocation is a bucket, and we can't arbitrarily allocate and 111 * free smaller than a bucket - so, that's how big our btree nodes are. 112 * 113 * (If buckets are really big we'll only use part of the bucket for a btree node 114 * - no less than 1/4th - but a bucket still contains no more than a single 115 * btree node. I'd actually like to change this, but for now we rely on the 116 * bucket's gen for deleting btree nodes when we rewrite/split a node.) 117 * 118 * Anyways, btree nodes are big - big enough to be inefficient with a textbook 119 * btree implementation. 120 * 121 * The way this is solved is that btree nodes are internally log structured; we 122 * can append new keys to an existing btree node without rewriting it. This 123 * means each set of keys we write is sorted, but the node is not. 124 * 125 * We maintain this log structure in memory - keeping 1Mb of keys sorted would 126 * be expensive, and we have to distinguish between the keys we have written and 127 * the keys we haven't. So to do a lookup in a btree node, we have to search 128 * each sorted set. But we do merge written sets together lazily, so the cost of 129 * these extra searches is quite low (normally most of the keys in a btree node 130 * will be in one big set, and then there'll be one or two sets that are much 131 * smaller). 132 * 133 * This log structure makes bcache's btree more of a hybrid between a 134 * conventional btree and a compacting data structure, with some of the 135 * advantages of both. 136 * 137 * GARBAGE COLLECTION: 138 * 139 * We can't just invalidate any bucket - it might contain dirty data or 140 * metadata. If it once contained dirty data, other writes might overwrite it 141 * later, leaving no valid pointers into that bucket in the index. 142 * 143 * Thus, the primary purpose of garbage collection is to find buckets to reuse. 144 * It also counts how much valid data it each bucket currently contains, so that 145 * allocation can reuse buckets sooner when they've been mostly overwritten. 146 * 147 * It also does some things that are really internal to the btree 148 * implementation. If a btree node contains pointers that are stale by more than 149 * some threshold, it rewrites the btree node to avoid the bucket's generation 150 * wrapping around. It also merges adjacent btree nodes if they're empty enough. 151 * 152 * THE JOURNAL: 153 * 154 * Bcache's journal is not necessary for consistency; we always strictly 155 * order metadata writes so that the btree and everything else is consistent on 156 * disk in the event of an unclean shutdown, and in fact bcache had writeback 157 * caching (with recovery from unclean shutdown) before journalling was 158 * implemented. 159 * 160 * Rather, the journal is purely a performance optimization; we can't complete a 161 * write until we've updated the index on disk, otherwise the cache would be 162 * inconsistent in the event of an unclean shutdown. This means that without the 163 * journal, on random write workloads we constantly have to update all the leaf 164 * nodes in the btree, and those writes will be mostly empty (appending at most 165 * a few keys each) - highly inefficient in terms of amount of metadata writes, 166 * and it puts more strain on the various btree resorting/compacting code. 167 * 168 * The journal is just a log of keys we've inserted; on startup we just reinsert 169 * all the keys in the open journal entries. That means that when we're updating 170 * a node in the btree, we can wait until a 4k block of keys fills up before 171 * writing them out. 172 * 173 * For simplicity, we only journal updates to leaf nodes; updates to parent 174 * nodes are rare enough (since our leaf nodes are huge) that it wasn't worth 175 * the complexity to deal with journalling them (in particular, journal replay) 176 * - updates to non leaf nodes just happen synchronously (see btree_split()). 177 */ 178 179 #undef pr_fmt 180 #ifdef __KERNEL__ 181 #define pr_fmt(fmt) "bcachefs: %s() " fmt "\n", __func__ 182 #else 183 #define pr_fmt(fmt) "%s() " fmt "\n", __func__ 184 #endif 185 186 #include <linux/backing-dev-defs.h> 187 #include <linux/bug.h> 188 #include <linux/bio.h> 189 #include <linux/closure.h> 190 #include <linux/kobject.h> 191 #include <linux/list.h> 192 #include <linux/math64.h> 193 #include <linux/mutex.h> 194 #include <linux/percpu-refcount.h> 195 #include <linux/percpu-rwsem.h> 196 #include <linux/refcount.h> 197 #include <linux/rhashtable.h> 198 #include <linux/rwsem.h> 199 #include <linux/semaphore.h> 200 #include <linux/seqlock.h> 201 #include <linux/shrinker.h> 202 #include <linux/srcu.h> 203 #include <linux/types.h> 204 #include <linux/workqueue.h> 205 #include <linux/zstd.h> 206 207 #include "bcachefs_format.h" 208 #include "errcode.h" 209 #include "fifo.h" 210 #include "nocow_locking_types.h" 211 #include "opts.h" 212 #include "recovery_passes_types.h" 213 #include "sb-errors_types.h" 214 #include "seqmutex.h" 215 #include "time_stats.h" 216 #include "util.h" 217 218 #ifdef CONFIG_BCACHEFS_DEBUG 219 #define BCH_WRITE_REF_DEBUG 220 #endif 221 222 #ifndef dynamic_fault 223 #define dynamic_fault(...) 0 224 #endif 225 226 #define race_fault(...) dynamic_fault("bcachefs:race") 227 228 #define count_event(_c, _name) this_cpu_inc((_c)->counters[BCH_COUNTER_##_name]) 229 230 #define trace_and_count(_c, _name, ...) \ 231 do { \ 232 count_event(_c, _name); \ 233 trace_##_name(__VA_ARGS__); \ 234 } while (0) 235 236 #define bch2_fs_init_fault(name) \ 237 dynamic_fault("bcachefs:bch_fs_init:" name) 238 #define bch2_meta_read_fault(name) \ 239 dynamic_fault("bcachefs:meta:read:" name) 240 #define bch2_meta_write_fault(name) \ 241 dynamic_fault("bcachefs:meta:write:" name) 242 243 #ifdef __KERNEL__ 244 #define BCACHEFS_LOG_PREFIX 245 #endif 246 247 #ifdef BCACHEFS_LOG_PREFIX 248 249 #define bch2_log_msg(_c, fmt) "bcachefs (%s): " fmt, ((_c)->name) 250 #define bch2_fmt_dev(_ca, fmt) "bcachefs (%s): " fmt "\n", ((_ca)->name) 251 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset) 252 #define bch2_fmt_inum(_c, _inum, fmt) "bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum) 253 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 254 "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset) 255 256 #else 257 258 #define bch2_log_msg(_c, fmt) fmt 259 #define bch2_fmt_dev(_ca, fmt) "%s: " fmt "\n", ((_ca)->name) 260 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "%s sector %llu: " fmt "\n", ((_ca)->name), (_offset) 261 #define bch2_fmt_inum(_c, _inum, fmt) "inum %llu: " fmt "\n", (_inum) 262 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 263 "inum %llu offset %llu: " fmt "\n", (_inum), (_offset) 264 265 #endif 266 267 #define bch2_fmt(_c, fmt) bch2_log_msg(_c, fmt "\n") 268 269 __printf(2, 3) 270 void bch2_print_opts(struct bch_opts *, const char *, ...); 271 272 __printf(2, 3) 273 void __bch2_print(struct bch_fs *c, const char *fmt, ...); 274 275 #define maybe_dev_to_fs(_c) _Generic((_c), \ 276 struct bch_dev *: ((struct bch_dev *) (_c))->fs, \ 277 struct bch_fs *: (_c)) 278 279 #define bch2_print(_c, ...) __bch2_print(maybe_dev_to_fs(_c), __VA_ARGS__) 280 281 #define bch2_print_ratelimited(_c, ...) \ 282 do { \ 283 static DEFINE_RATELIMIT_STATE(_rs, \ 284 DEFAULT_RATELIMIT_INTERVAL, \ 285 DEFAULT_RATELIMIT_BURST); \ 286 \ 287 if (__ratelimit(&_rs)) \ 288 bch2_print(_c, __VA_ARGS__); \ 289 } while (0) 290 291 #define bch_info(c, fmt, ...) \ 292 bch2_print(c, KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__) 293 #define bch_notice(c, fmt, ...) \ 294 bch2_print(c, KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__) 295 #define bch_warn(c, fmt, ...) \ 296 bch2_print(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 297 #define bch_warn_ratelimited(c, fmt, ...) \ 298 bch2_print_ratelimited(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 299 300 #define bch_err(c, fmt, ...) \ 301 bch2_print(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 302 #define bch_err_dev(ca, fmt, ...) \ 303 bch2_print(c, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 304 #define bch_err_dev_offset(ca, _offset, fmt, ...) \ 305 bch2_print(c, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 306 #define bch_err_inum(c, _inum, fmt, ...) \ 307 bch2_print(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 308 #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \ 309 bch2_print(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 310 311 #define bch_err_ratelimited(c, fmt, ...) \ 312 bch2_print_ratelimited(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 313 #define bch_err_dev_ratelimited(ca, fmt, ...) \ 314 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 315 #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \ 316 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 317 #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \ 318 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 319 #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \ 320 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 321 322 static inline bool should_print_err(int err) 323 { 324 return err && !bch2_err_matches(err, BCH_ERR_transaction_restart); 325 } 326 327 #define bch_err_fn(_c, _ret) \ 328 do { \ 329 if (should_print_err(_ret)) \ 330 bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ 331 } while (0) 332 333 #define bch_err_fn_ratelimited(_c, _ret) \ 334 do { \ 335 if (should_print_err(_ret)) \ 336 bch_err_ratelimited(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ 337 } while (0) 338 339 #define bch_err_msg(_c, _ret, _msg, ...) \ 340 do { \ 341 if (should_print_err(_ret)) \ 342 bch_err(_c, "%s(): error " _msg " %s", __func__, \ 343 ##__VA_ARGS__, bch2_err_str(_ret)); \ 344 } while (0) 345 346 #define bch_verbose(c, fmt, ...) \ 347 do { \ 348 if ((c)->opts.verbose) \ 349 bch_info(c, fmt, ##__VA_ARGS__); \ 350 } while (0) 351 352 #define pr_verbose_init(opts, fmt, ...) \ 353 do { \ 354 if (opt_get(opts, verbose)) \ 355 pr_info(fmt, ##__VA_ARGS__); \ 356 } while (0) 357 358 /* Parameters that are useful for debugging, but should always be compiled in: */ 359 #define BCH_DEBUG_PARAMS_ALWAYS() \ 360 BCH_DEBUG_PARAM(key_merging_disabled, \ 361 "Disables merging of extents") \ 362 BCH_DEBUG_PARAM(btree_node_merging_disabled, \ 363 "Disables merging of btree nodes") \ 364 BCH_DEBUG_PARAM(btree_gc_always_rewrite, \ 365 "Causes mark and sweep to compact and rewrite every " \ 366 "btree node it traverses") \ 367 BCH_DEBUG_PARAM(btree_gc_rewrite_disabled, \ 368 "Disables rewriting of btree nodes during mark and sweep")\ 369 BCH_DEBUG_PARAM(btree_shrinker_disabled, \ 370 "Disables the shrinker callback for the btree node cache")\ 371 BCH_DEBUG_PARAM(verify_btree_ondisk, \ 372 "Reread btree nodes at various points to verify the " \ 373 "mergesort in the read path against modifications " \ 374 "done in memory") \ 375 BCH_DEBUG_PARAM(verify_all_btree_replicas, \ 376 "When reading btree nodes, read all replicas and " \ 377 "compare them") \ 378 BCH_DEBUG_PARAM(backpointers_no_use_write_buffer, \ 379 "Don't use the write buffer for backpointers, enabling "\ 380 "extra runtime checks") 381 382 /* Parameters that should only be compiled in debug mode: */ 383 #define BCH_DEBUG_PARAMS_DEBUG() \ 384 BCH_DEBUG_PARAM(expensive_debug_checks, \ 385 "Enables various runtime debugging checks that " \ 386 "significantly affect performance") \ 387 BCH_DEBUG_PARAM(debug_check_iterators, \ 388 "Enables extra verification for btree iterators") \ 389 BCH_DEBUG_PARAM(debug_check_btree_accounting, \ 390 "Verify btree accounting for keys within a node") \ 391 BCH_DEBUG_PARAM(journal_seq_verify, \ 392 "Store the journal sequence number in the version " \ 393 "number of every btree key, and verify that btree " \ 394 "update ordering is preserved during recovery") \ 395 BCH_DEBUG_PARAM(inject_invalid_keys, \ 396 "Store the journal sequence number in the version " \ 397 "number of every btree key, and verify that btree " \ 398 "update ordering is preserved during recovery") \ 399 BCH_DEBUG_PARAM(test_alloc_startup, \ 400 "Force allocator startup to use the slowpath where it" \ 401 "can't find enough free buckets without invalidating" \ 402 "cached data") \ 403 BCH_DEBUG_PARAM(force_reconstruct_read, \ 404 "Force reads to use the reconstruct path, when reading" \ 405 "from erasure coded extents") \ 406 BCH_DEBUG_PARAM(test_restart_gc, \ 407 "Test restarting mark and sweep gc when bucket gens change") 408 409 #define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG() 410 411 #ifdef CONFIG_BCACHEFS_DEBUG 412 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL() 413 #else 414 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS() 415 #endif 416 417 #define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name; 418 BCH_DEBUG_PARAMS() 419 #undef BCH_DEBUG_PARAM 420 421 #ifndef CONFIG_BCACHEFS_DEBUG 422 #define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name; 423 BCH_DEBUG_PARAMS_DEBUG() 424 #undef BCH_DEBUG_PARAM 425 #endif 426 427 #define BCH_TIME_STATS() \ 428 x(btree_node_mem_alloc) \ 429 x(btree_node_split) \ 430 x(btree_node_compact) \ 431 x(btree_node_merge) \ 432 x(btree_node_sort) \ 433 x(btree_node_read) \ 434 x(btree_node_read_done) \ 435 x(btree_interior_update_foreground) \ 436 x(btree_interior_update_total) \ 437 x(btree_gc) \ 438 x(data_write) \ 439 x(data_read) \ 440 x(data_promote) \ 441 x(journal_flush_write) \ 442 x(journal_noflush_write) \ 443 x(journal_flush_seq) \ 444 x(blocked_journal_low_on_space) \ 445 x(blocked_journal_low_on_pin) \ 446 x(blocked_journal_max_in_flight) \ 447 x(blocked_allocate) \ 448 x(blocked_allocate_open_bucket) \ 449 x(blocked_write_buffer_full) \ 450 x(nocow_lock_contended) 451 452 enum bch_time_stats { 453 #define x(name) BCH_TIME_##name, 454 BCH_TIME_STATS() 455 #undef x 456 BCH_TIME_STAT_NR 457 }; 458 459 #include "alloc_types.h" 460 #include "btree_gc_types.h" 461 #include "btree_types.h" 462 #include "btree_node_scan_types.h" 463 #include "btree_write_buffer_types.h" 464 #include "buckets_types.h" 465 #include "buckets_waiting_for_journal_types.h" 466 #include "clock_types.h" 467 #include "disk_groups_types.h" 468 #include "ec_types.h" 469 #include "journal_types.h" 470 #include "keylist_types.h" 471 #include "quota_types.h" 472 #include "rebalance_types.h" 473 #include "replicas_types.h" 474 #include "sb-members_types.h" 475 #include "subvolume_types.h" 476 #include "super_types.h" 477 #include "thread_with_file_types.h" 478 479 /* Number of nodes btree coalesce will try to coalesce at once */ 480 #define GC_MERGE_NODES 4U 481 482 /* Maximum number of nodes we might need to allocate atomically: */ 483 #define BTREE_RESERVE_MAX (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1)) 484 485 /* Size of the freelist we allocate btree nodes from: */ 486 #define BTREE_NODE_RESERVE (BTREE_RESERVE_MAX * 4) 487 488 #define BTREE_NODE_OPEN_BUCKET_RESERVE (BTREE_RESERVE_MAX * BCH_REPLICAS_MAX) 489 490 struct btree; 491 492 struct io_count { 493 u64 sectors[2][BCH_DATA_NR]; 494 }; 495 496 struct bch_dev { 497 struct kobject kobj; 498 #ifdef CONFIG_BCACHEFS_DEBUG 499 atomic_long_t ref; 500 bool dying; 501 unsigned long last_put; 502 #else 503 struct percpu_ref ref; 504 #endif 505 struct completion ref_completion; 506 struct percpu_ref io_ref; 507 struct completion io_ref_completion; 508 509 struct bch_fs *fs; 510 511 u8 dev_idx; 512 /* 513 * Cached version of this device's member info from superblock 514 * Committed by bch2_write_super() -> bch_fs_mi_update() 515 */ 516 struct bch_member_cpu mi; 517 atomic64_t errors[BCH_MEMBER_ERROR_NR]; 518 519 __uuid_t uuid; 520 char name[BDEVNAME_SIZE]; 521 522 struct bch_sb_handle disk_sb; 523 struct bch_sb *sb_read_scratch; 524 int sb_write_error; 525 dev_t dev; 526 atomic_t flush_seq; 527 528 struct bch_devs_mask self; 529 530 /* 531 * Buckets: 532 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and 533 * gc_lock, for device resize - holding any is sufficient for access: 534 * Or rcu_read_lock(), but only for dev_ptr_stale(): 535 */ 536 struct bucket_array __rcu *buckets_gc; 537 struct bucket_gens __rcu *bucket_gens; 538 u8 *oldest_gen; 539 unsigned long *buckets_nouse; 540 struct rw_semaphore bucket_lock; 541 542 struct bch_dev_usage *usage_base; 543 struct bch_dev_usage __percpu *usage[JOURNAL_BUF_NR]; 544 struct bch_dev_usage __percpu *usage_gc; 545 546 /* Allocator: */ 547 u64 new_fs_bucket_idx; 548 u64 alloc_cursor[3]; 549 550 unsigned nr_open_buckets; 551 unsigned nr_btree_reserve; 552 553 size_t inc_gen_needs_gc; 554 size_t inc_gen_really_needs_gc; 555 size_t buckets_waiting_on_journal; 556 557 atomic64_t rebalance_work; 558 559 struct journal_device journal; 560 u64 prev_journal_sector; 561 562 struct work_struct io_error_work; 563 564 /* The rest of this all shows up in sysfs */ 565 atomic64_t cur_latency[2]; 566 struct bch2_time_stats_quantiles io_latency[2]; 567 568 #define CONGESTED_MAX 1024 569 atomic_t congested; 570 u64 congested_last; 571 572 struct io_count __percpu *io_done; 573 }; 574 575 /* 576 * initial_gc_unfixed 577 * error 578 * topology error 579 */ 580 581 #define BCH_FS_FLAGS() \ 582 x(new_fs) \ 583 x(started) \ 584 x(may_go_rw) \ 585 x(rw) \ 586 x(was_rw) \ 587 x(stopping) \ 588 x(emergency_ro) \ 589 x(going_ro) \ 590 x(write_disable_complete) \ 591 x(clean_shutdown) \ 592 x(fsck_running) \ 593 x(initial_gc_unfixed) \ 594 x(need_delete_dead_snapshots) \ 595 x(error) \ 596 x(topology_error) \ 597 x(errors_fixed) \ 598 x(errors_not_fixed) \ 599 x(no_invalid_checks) 600 601 enum bch_fs_flags { 602 #define x(n) BCH_FS_##n, 603 BCH_FS_FLAGS() 604 #undef x 605 }; 606 607 struct btree_debug { 608 unsigned id; 609 }; 610 611 #define BCH_TRANSACTIONS_NR 128 612 613 struct btree_transaction_stats { 614 struct bch2_time_stats duration; 615 struct bch2_time_stats lock_hold_times; 616 struct mutex lock; 617 unsigned nr_max_paths; 618 unsigned journal_entries_size; 619 unsigned max_mem; 620 char *max_paths_text; 621 }; 622 623 struct bch_fs_pcpu { 624 u64 sectors_available; 625 }; 626 627 struct journal_seq_blacklist_table { 628 size_t nr; 629 struct journal_seq_blacklist_table_entry { 630 u64 start; 631 u64 end; 632 bool dirty; 633 } entries[]; 634 }; 635 636 struct journal_keys { 637 /* must match layout in darray_types.h */ 638 size_t nr, size; 639 struct journal_key { 640 u64 journal_seq; 641 u32 journal_offset; 642 enum btree_id btree_id:8; 643 unsigned level:8; 644 bool allocated; 645 bool overwritten; 646 struct bkey_i *k; 647 } *data; 648 /* 649 * Gap buffer: instead of all the empty space in the array being at the 650 * end of the buffer - from @nr to @size - the empty space is at @gap. 651 * This means that sequential insertions are O(n) instead of O(n^2). 652 */ 653 size_t gap; 654 atomic_t ref; 655 bool initial_ref_held; 656 }; 657 658 struct btree_trans_buf { 659 struct btree_trans *trans; 660 }; 661 662 #define REPLICAS_DELTA_LIST_MAX (1U << 16) 663 664 #define BCACHEFS_ROOT_SUBVOL_INUM \ 665 ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO }) 666 667 #define BCH_WRITE_REFS() \ 668 x(trans) \ 669 x(write) \ 670 x(promote) \ 671 x(node_rewrite) \ 672 x(stripe_create) \ 673 x(stripe_delete) \ 674 x(reflink) \ 675 x(fallocate) \ 676 x(fsync) \ 677 x(dio_write) \ 678 x(discard) \ 679 x(discard_fast) \ 680 x(invalidate) \ 681 x(delete_dead_snapshots) \ 682 x(gc_gens) \ 683 x(snapshot_delete_pagecache) \ 684 x(sysfs) \ 685 x(btree_write_buffer) 686 687 enum bch_write_ref { 688 #define x(n) BCH_WRITE_REF_##n, 689 BCH_WRITE_REFS() 690 #undef x 691 BCH_WRITE_REF_NR, 692 }; 693 694 struct bch_fs { 695 struct closure cl; 696 697 struct list_head list; 698 struct kobject kobj; 699 struct kobject counters_kobj; 700 struct kobject internal; 701 struct kobject opts_dir; 702 struct kobject time_stats; 703 unsigned long flags; 704 705 int minor; 706 struct device *chardev; 707 struct super_block *vfs_sb; 708 dev_t dev; 709 char name[40]; 710 struct stdio_redirect *stdio; 711 struct task_struct *stdio_filter; 712 713 /* ro/rw, add/remove/resize devices: */ 714 struct rw_semaphore state_lock; 715 716 /* Counts outstanding writes, for clean transition to read-only */ 717 #ifdef BCH_WRITE_REF_DEBUG 718 atomic_long_t writes[BCH_WRITE_REF_NR]; 719 #else 720 struct percpu_ref writes; 721 #endif 722 /* 723 * Analagous to c->writes, for asynchronous ops that don't necessarily 724 * need fs to be read-write 725 */ 726 refcount_t ro_ref; 727 wait_queue_head_t ro_ref_wait; 728 729 struct work_struct read_only_work; 730 731 struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX]; 732 733 struct bch_replicas_cpu replicas; 734 struct bch_replicas_cpu replicas_gc; 735 struct mutex replicas_gc_lock; 736 mempool_t replicas_delta_pool; 737 738 struct journal_entry_res btree_root_journal_res; 739 struct journal_entry_res replicas_journal_res; 740 struct journal_entry_res clock_journal_res; 741 struct journal_entry_res dev_usage_journal_res; 742 743 struct bch_disk_groups_cpu __rcu *disk_groups; 744 745 struct bch_opts opts; 746 747 /* Updated by bch2_sb_update():*/ 748 struct { 749 __uuid_t uuid; 750 __uuid_t user_uuid; 751 752 u16 version; 753 u16 version_min; 754 u16 version_upgrade_complete; 755 756 u8 nr_devices; 757 u8 clean; 758 759 u8 encryption_type; 760 761 u64 time_base_lo; 762 u32 time_base_hi; 763 unsigned time_units_per_sec; 764 unsigned nsec_per_time_unit; 765 u64 features; 766 u64 compat; 767 unsigned long errors_silent[BITS_TO_LONGS(BCH_SB_ERR_MAX)]; 768 u64 btrees_lost_data; 769 } sb; 770 771 772 struct bch_sb_handle disk_sb; 773 774 unsigned short block_bits; /* ilog2(block_size) */ 775 776 u16 btree_foreground_merge_threshold; 777 778 struct closure sb_write; 779 struct mutex sb_lock; 780 781 /* snapshot.c: */ 782 struct snapshot_table __rcu *snapshots; 783 struct mutex snapshot_table_lock; 784 struct rw_semaphore snapshot_create_lock; 785 786 struct work_struct snapshot_delete_work; 787 struct work_struct snapshot_wait_for_pagecache_and_delete_work; 788 snapshot_id_list snapshots_unlinked; 789 struct mutex snapshots_unlinked_lock; 790 791 /* BTREE CACHE */ 792 struct bio_set btree_bio; 793 struct workqueue_struct *btree_read_complete_wq; 794 struct workqueue_struct *btree_write_submit_wq; 795 796 struct btree_root btree_roots_known[BTREE_ID_NR]; 797 DARRAY(struct btree_root) btree_roots_extra; 798 struct mutex btree_root_lock; 799 800 struct btree_cache btree_cache; 801 802 /* 803 * Cache of allocated btree nodes - if we allocate a btree node and 804 * don't use it, if we free it that space can't be reused until going 805 * _all_ the way through the allocator (which exposes us to a livelock 806 * when allocating btree reserves fail halfway through) - instead, we 807 * can stick them here: 808 */ 809 struct btree_alloc btree_reserve_cache[BTREE_NODE_RESERVE * 2]; 810 unsigned btree_reserve_cache_nr; 811 struct mutex btree_reserve_cache_lock; 812 813 mempool_t btree_interior_update_pool; 814 struct list_head btree_interior_update_list; 815 struct list_head btree_interior_updates_unwritten; 816 struct mutex btree_interior_update_lock; 817 struct closure_waitlist btree_interior_update_wait; 818 819 struct workqueue_struct *btree_interior_update_worker; 820 struct work_struct btree_interior_update_work; 821 822 struct workqueue_struct *btree_node_rewrite_worker; 823 824 struct list_head pending_node_rewrites; 825 struct mutex pending_node_rewrites_lock; 826 827 /* btree_io.c: */ 828 spinlock_t btree_write_error_lock; 829 struct btree_write_stats { 830 atomic64_t nr; 831 atomic64_t bytes; 832 } btree_write_stats[BTREE_WRITE_TYPE_NR]; 833 834 /* btree_iter.c: */ 835 struct seqmutex btree_trans_lock; 836 struct list_head btree_trans_list; 837 mempool_t btree_trans_pool; 838 mempool_t btree_trans_mem_pool; 839 struct btree_trans_buf __percpu *btree_trans_bufs; 840 841 struct srcu_struct btree_trans_barrier; 842 bool btree_trans_barrier_initialized; 843 844 struct btree_key_cache btree_key_cache; 845 unsigned btree_key_cache_btrees; 846 847 struct btree_write_buffer btree_write_buffer; 848 849 struct workqueue_struct *btree_update_wq; 850 struct workqueue_struct *btree_io_complete_wq; 851 /* copygc needs its own workqueue for index updates.. */ 852 struct workqueue_struct *copygc_wq; 853 /* 854 * Use a dedicated wq for write ref holder tasks. Required to avoid 855 * dependency problems with other wq tasks that can block on ref 856 * draining, such as read-only transition. 857 */ 858 struct workqueue_struct *write_ref_wq; 859 860 /* ALLOCATION */ 861 struct bch_devs_mask rw_devs[BCH_DATA_NR]; 862 863 u64 capacity; /* sectors */ 864 865 /* 866 * When capacity _decreases_ (due to a disk being removed), we 867 * increment capacity_gen - this invalidates outstanding reservations 868 * and forces them to be revalidated 869 */ 870 u32 capacity_gen; 871 unsigned bucket_size_max; 872 873 atomic64_t sectors_available; 874 struct mutex sectors_available_lock; 875 876 struct bch_fs_pcpu __percpu *pcpu; 877 878 struct percpu_rw_semaphore mark_lock; 879 880 seqcount_t usage_lock; 881 struct bch_fs_usage *usage_base; 882 struct bch_fs_usage __percpu *usage[JOURNAL_BUF_NR]; 883 struct bch_fs_usage __percpu *usage_gc; 884 u64 __percpu *online_reserved; 885 886 /* single element mempool: */ 887 struct mutex usage_scratch_lock; 888 struct bch_fs_usage_online *usage_scratch; 889 890 struct io_clock io_clock[2]; 891 892 /* JOURNAL SEQ BLACKLIST */ 893 struct journal_seq_blacklist_table * 894 journal_seq_blacklist_table; 895 896 /* ALLOCATOR */ 897 spinlock_t freelist_lock; 898 struct closure_waitlist freelist_wait; 899 900 open_bucket_idx_t open_buckets_freelist; 901 open_bucket_idx_t open_buckets_nr_free; 902 struct closure_waitlist open_buckets_wait; 903 struct open_bucket open_buckets[OPEN_BUCKETS_COUNT]; 904 open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT]; 905 906 open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT]; 907 open_bucket_idx_t open_buckets_partial_nr; 908 909 struct write_point btree_write_point; 910 struct write_point rebalance_write_point; 911 912 struct write_point write_points[WRITE_POINT_MAX]; 913 struct hlist_head write_points_hash[WRITE_POINT_HASH_NR]; 914 struct mutex write_points_hash_lock; 915 unsigned write_points_nr; 916 917 struct buckets_waiting_for_journal buckets_waiting_for_journal; 918 struct work_struct invalidate_work; 919 struct work_struct discard_work; 920 struct mutex discard_buckets_in_flight_lock; 921 DARRAY(struct bpos) discard_buckets_in_flight; 922 struct work_struct discard_fast_work; 923 924 /* GARBAGE COLLECTION */ 925 struct work_struct gc_gens_work; 926 unsigned long gc_count; 927 928 enum btree_id gc_gens_btree; 929 struct bpos gc_gens_pos; 930 931 /* 932 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos] 933 * has been marked by GC. 934 * 935 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.) 936 * 937 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread 938 * can read without a lock. 939 */ 940 seqcount_t gc_pos_lock; 941 struct gc_pos gc_pos; 942 943 /* 944 * The allocation code needs gc_mark in struct bucket to be correct, but 945 * it's not while a gc is in progress. 946 */ 947 struct rw_semaphore gc_lock; 948 struct mutex gc_gens_lock; 949 950 /* IO PATH */ 951 struct semaphore io_in_flight; 952 struct bio_set bio_read; 953 struct bio_set bio_read_split; 954 struct bio_set bio_write; 955 struct bio_set replica_set; 956 struct mutex bio_bounce_pages_lock; 957 mempool_t bio_bounce_pages; 958 struct bucket_nocow_lock_table 959 nocow_locks; 960 struct rhashtable promote_table; 961 962 mempool_t compression_bounce[2]; 963 mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR]; 964 mempool_t decompress_workspace; 965 size_t zstd_workspace_size; 966 967 struct crypto_shash *sha256; 968 struct crypto_sync_skcipher *chacha20; 969 struct crypto_shash *poly1305; 970 971 atomic64_t key_version; 972 973 mempool_t large_bkey_pool; 974 975 /* MOVE.C */ 976 struct list_head moving_context_list; 977 struct mutex moving_context_lock; 978 979 /* REBALANCE */ 980 struct bch_fs_rebalance rebalance; 981 982 /* COPYGC */ 983 struct task_struct *copygc_thread; 984 struct write_point copygc_write_point; 985 s64 copygc_wait_at; 986 s64 copygc_wait; 987 bool copygc_running; 988 wait_queue_head_t copygc_running_wq; 989 990 /* STRIPES: */ 991 GENRADIX(struct stripe) stripes; 992 GENRADIX(struct gc_stripe) gc_stripes; 993 994 struct hlist_head ec_stripes_new[32]; 995 spinlock_t ec_stripes_new_lock; 996 997 ec_stripes_heap ec_stripes_heap; 998 struct mutex ec_stripes_heap_lock; 999 1000 /* ERASURE CODING */ 1001 struct list_head ec_stripe_head_list; 1002 struct mutex ec_stripe_head_lock; 1003 1004 struct list_head ec_stripe_new_list; 1005 struct mutex ec_stripe_new_lock; 1006 wait_queue_head_t ec_stripe_new_wait; 1007 1008 struct work_struct ec_stripe_create_work; 1009 u64 ec_stripe_hint; 1010 1011 struct work_struct ec_stripe_delete_work; 1012 1013 struct bio_set ec_bioset; 1014 1015 /* REFLINK */ 1016 reflink_gc_table reflink_gc_table; 1017 size_t reflink_gc_nr; 1018 1019 /* fs.c */ 1020 struct list_head vfs_inodes_list; 1021 struct mutex vfs_inodes_lock; 1022 1023 /* VFS IO PATH - fs-io.c */ 1024 struct bio_set writepage_bioset; 1025 struct bio_set dio_write_bioset; 1026 struct bio_set dio_read_bioset; 1027 struct bio_set nocow_flush_bioset; 1028 1029 /* QUOTAS */ 1030 struct bch_memquota_type quotas[QTYP_NR]; 1031 1032 /* RECOVERY */ 1033 u64 journal_replay_seq_start; 1034 u64 journal_replay_seq_end; 1035 /* 1036 * Two different uses: 1037 * "Has this fsck pass?" - i.e. should this type of error be an 1038 * emergency read-only 1039 * And, in certain situations fsck will rewind to an earlier pass: used 1040 * for signaling to the toplevel code which pass we want to run now. 1041 */ 1042 enum bch_recovery_pass curr_recovery_pass; 1043 /* bitmap of explicitly enabled recovery passes: */ 1044 u64 recovery_passes_explicit; 1045 /* bitmask of recovery passes that we actually ran */ 1046 u64 recovery_passes_complete; 1047 /* never rewinds version of curr_recovery_pass */ 1048 enum bch_recovery_pass recovery_pass_done; 1049 struct semaphore online_fsck_mutex; 1050 1051 /* DEBUG JUNK */ 1052 struct dentry *fs_debug_dir; 1053 struct dentry *btree_debug_dir; 1054 struct btree_debug btree_debug[BTREE_ID_NR]; 1055 struct btree *verify_data; 1056 struct btree_node *verify_ondisk; 1057 struct mutex verify_lock; 1058 1059 u64 *unused_inode_hints; 1060 unsigned inode_shard_bits; 1061 1062 /* 1063 * A btree node on disk could have too many bsets for an iterator to fit 1064 * on the stack - have to dynamically allocate them 1065 */ 1066 mempool_t fill_iter; 1067 1068 mempool_t btree_bounce_pool; 1069 1070 struct journal journal; 1071 GENRADIX(struct journal_replay *) journal_entries; 1072 u64 journal_entries_base_seq; 1073 struct journal_keys journal_keys; 1074 struct list_head journal_iters; 1075 1076 struct find_btree_nodes found_btree_nodes; 1077 1078 u64 last_bucket_seq_cleanup; 1079 1080 u64 counters_on_mount[BCH_COUNTER_NR]; 1081 u64 __percpu *counters; 1082 1083 unsigned copy_gc_enabled:1; 1084 bool promote_whole_extents; 1085 1086 struct bch2_time_stats times[BCH_TIME_STAT_NR]; 1087 1088 struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR]; 1089 1090 /* ERRORS */ 1091 struct list_head fsck_error_msgs; 1092 struct mutex fsck_error_msgs_lock; 1093 bool fsck_alloc_msgs_err; 1094 1095 bch_sb_errors_cpu fsck_error_counts; 1096 struct mutex fsck_error_counts_lock; 1097 }; 1098 1099 extern struct wait_queue_head bch2_read_only_wait; 1100 1101 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref) 1102 { 1103 #ifdef BCH_WRITE_REF_DEBUG 1104 atomic_long_inc(&c->writes[ref]); 1105 #else 1106 percpu_ref_get(&c->writes); 1107 #endif 1108 } 1109 1110 static inline bool __bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1111 { 1112 #ifdef BCH_WRITE_REF_DEBUG 1113 return !test_bit(BCH_FS_going_ro, &c->flags) && 1114 atomic_long_inc_not_zero(&c->writes[ref]); 1115 #else 1116 return percpu_ref_tryget(&c->writes); 1117 #endif 1118 } 1119 1120 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1121 { 1122 #ifdef BCH_WRITE_REF_DEBUG 1123 return !test_bit(BCH_FS_going_ro, &c->flags) && 1124 atomic_long_inc_not_zero(&c->writes[ref]); 1125 #else 1126 return percpu_ref_tryget_live(&c->writes); 1127 #endif 1128 } 1129 1130 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref) 1131 { 1132 #ifdef BCH_WRITE_REF_DEBUG 1133 long v = atomic_long_dec_return(&c->writes[ref]); 1134 1135 BUG_ON(v < 0); 1136 if (v) 1137 return; 1138 for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) 1139 if (atomic_long_read(&c->writes[i])) 1140 return; 1141 1142 set_bit(BCH_FS_write_disable_complete, &c->flags); 1143 wake_up(&bch2_read_only_wait); 1144 #else 1145 percpu_ref_put(&c->writes); 1146 #endif 1147 } 1148 1149 static inline bool bch2_ro_ref_tryget(struct bch_fs *c) 1150 { 1151 if (test_bit(BCH_FS_stopping, &c->flags)) 1152 return false; 1153 1154 return refcount_inc_not_zero(&c->ro_ref); 1155 } 1156 1157 static inline void bch2_ro_ref_put(struct bch_fs *c) 1158 { 1159 if (refcount_dec_and_test(&c->ro_ref)) 1160 wake_up(&c->ro_ref_wait); 1161 } 1162 1163 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) 1164 { 1165 #ifndef NO_BCACHEFS_FS 1166 if (c->vfs_sb) 1167 c->vfs_sb->s_bdi->ra_pages = ra_pages; 1168 #endif 1169 } 1170 1171 static inline unsigned bucket_bytes(const struct bch_dev *ca) 1172 { 1173 return ca->mi.bucket_size << 9; 1174 } 1175 1176 static inline unsigned block_bytes(const struct bch_fs *c) 1177 { 1178 return c->opts.block_size; 1179 } 1180 1181 static inline unsigned block_sectors(const struct bch_fs *c) 1182 { 1183 return c->opts.block_size >> 9; 1184 } 1185 1186 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree) 1187 { 1188 return c->btree_key_cache_btrees & (1U << btree); 1189 } 1190 1191 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time) 1192 { 1193 struct timespec64 t; 1194 s32 rem; 1195 1196 time += c->sb.time_base_lo; 1197 1198 t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem); 1199 t.tv_nsec = rem * c->sb.nsec_per_time_unit; 1200 return t; 1201 } 1202 1203 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts) 1204 { 1205 return (ts.tv_sec * c->sb.time_units_per_sec + 1206 (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo; 1207 } 1208 1209 static inline s64 bch2_current_time(const struct bch_fs *c) 1210 { 1211 struct timespec64 now; 1212 1213 ktime_get_coarse_real_ts64(&now); 1214 return timespec_to_bch2_time(c, now); 1215 } 1216 1217 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c) 1218 { 1219 struct stdio_redirect *stdio = c->stdio; 1220 1221 if (c->stdio_filter && c->stdio_filter != current) 1222 stdio = NULL; 1223 return stdio; 1224 } 1225 1226 static inline unsigned metadata_replicas_required(struct bch_fs *c) 1227 { 1228 return min(c->opts.metadata_replicas, 1229 c->opts.metadata_replicas_required); 1230 } 1231 1232 static inline unsigned data_replicas_required(struct bch_fs *c) 1233 { 1234 return min(c->opts.data_replicas, 1235 c->opts.data_replicas_required); 1236 } 1237 1238 #define BKEY_PADDED_ONSTACK(key, pad) \ 1239 struct { struct bkey_i key; __u64 key ## _pad[pad]; } 1240 1241 #endif /* _BCACHEFS_H */ 1242