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 "disk_accounting_types.h" 209 #include "errcode.h" 210 #include "fifo.h" 211 #include "nocow_locking_types.h" 212 #include "opts.h" 213 #include "recovery_passes_types.h" 214 #include "sb-errors_types.h" 215 #include "seqmutex.h" 216 #include "time_stats.h" 217 #include "util.h" 218 219 #ifdef CONFIG_BCACHEFS_DEBUG 220 #define BCH_WRITE_REF_DEBUG 221 #endif 222 223 #ifndef dynamic_fault 224 #define dynamic_fault(...) 0 225 #endif 226 227 #define race_fault(...) dynamic_fault("bcachefs:race") 228 229 #define count_event(_c, _name) this_cpu_inc((_c)->counters[BCH_COUNTER_##_name]) 230 231 #define trace_and_count(_c, _name, ...) \ 232 do { \ 233 count_event(_c, _name); \ 234 trace_##_name(__VA_ARGS__); \ 235 } while (0) 236 237 #define bch2_fs_init_fault(name) \ 238 dynamic_fault("bcachefs:bch_fs_init:" name) 239 #define bch2_meta_read_fault(name) \ 240 dynamic_fault("bcachefs:meta:read:" name) 241 #define bch2_meta_write_fault(name) \ 242 dynamic_fault("bcachefs:meta:write:" name) 243 244 #ifdef __KERNEL__ 245 #define BCACHEFS_LOG_PREFIX 246 #endif 247 248 #ifdef BCACHEFS_LOG_PREFIX 249 250 #define bch2_log_msg(_c, fmt) "bcachefs (%s): " fmt, ((_c)->name) 251 #define bch2_fmt_dev(_ca, fmt) "bcachefs (%s): " fmt "\n", ((_ca)->name) 252 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset) 253 #define bch2_fmt_inum(_c, _inum, fmt) "bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum) 254 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 255 "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset) 256 257 #else 258 259 #define bch2_log_msg(_c, fmt) fmt 260 #define bch2_fmt_dev(_ca, fmt) "%s: " fmt "\n", ((_ca)->name) 261 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "%s sector %llu: " fmt "\n", ((_ca)->name), (_offset) 262 #define bch2_fmt_inum(_c, _inum, fmt) "inum %llu: " fmt "\n", (_inum) 263 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 264 "inum %llu offset %llu: " fmt "\n", (_inum), (_offset) 265 266 #endif 267 268 #define bch2_fmt(_c, fmt) bch2_log_msg(_c, fmt "\n") 269 270 void bch2_print_str(struct bch_fs *, const char *); 271 272 __printf(2, 3) 273 void bch2_print_opts(struct bch_opts *, const char *, ...); 274 275 __printf(2, 3) 276 void __bch2_print(struct bch_fs *c, const char *fmt, ...); 277 278 #define maybe_dev_to_fs(_c) _Generic((_c), \ 279 struct bch_dev *: ((struct bch_dev *) (_c))->fs, \ 280 struct bch_fs *: (_c)) 281 282 #define bch2_print(_c, ...) __bch2_print(maybe_dev_to_fs(_c), __VA_ARGS__) 283 284 #define bch2_print_ratelimited(_c, ...) \ 285 do { \ 286 static DEFINE_RATELIMIT_STATE(_rs, \ 287 DEFAULT_RATELIMIT_INTERVAL, \ 288 DEFAULT_RATELIMIT_BURST); \ 289 \ 290 if (__ratelimit(&_rs)) \ 291 bch2_print(_c, __VA_ARGS__); \ 292 } while (0) 293 294 #define bch_info(c, fmt, ...) \ 295 bch2_print(c, KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__) 296 #define bch_notice(c, fmt, ...) \ 297 bch2_print(c, KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__) 298 #define bch_warn(c, fmt, ...) \ 299 bch2_print(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 300 #define bch_warn_ratelimited(c, fmt, ...) \ 301 bch2_print_ratelimited(c, KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 302 303 #define bch_err(c, fmt, ...) \ 304 bch2_print(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 305 #define bch_err_dev(ca, fmt, ...) \ 306 bch2_print(c, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 307 #define bch_err_dev_offset(ca, _offset, fmt, ...) \ 308 bch2_print(c, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 309 #define bch_err_inum(c, _inum, fmt, ...) \ 310 bch2_print(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 311 #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \ 312 bch2_print(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 313 314 #define bch_err_ratelimited(c, fmt, ...) \ 315 bch2_print_ratelimited(c, KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 316 #define bch_err_dev_ratelimited(ca, fmt, ...) \ 317 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 318 #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \ 319 bch2_print_ratelimited(ca, KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 320 #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \ 321 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 322 #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \ 323 bch2_print_ratelimited(c, KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 324 325 static inline bool should_print_err(int err) 326 { 327 return err && !bch2_err_matches(err, BCH_ERR_transaction_restart); 328 } 329 330 #define bch_err_fn(_c, _ret) \ 331 do { \ 332 if (should_print_err(_ret)) \ 333 bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ 334 } while (0) 335 336 #define bch_err_fn_ratelimited(_c, _ret) \ 337 do { \ 338 if (should_print_err(_ret)) \ 339 bch_err_ratelimited(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ 340 } while (0) 341 342 #define bch_err_msg(_c, _ret, _msg, ...) \ 343 do { \ 344 if (should_print_err(_ret)) \ 345 bch_err(_c, "%s(): error " _msg " %s", __func__, \ 346 ##__VA_ARGS__, bch2_err_str(_ret)); \ 347 } while (0) 348 349 #define bch_verbose(c, fmt, ...) \ 350 do { \ 351 if ((c)->opts.verbose) \ 352 bch_info(c, fmt, ##__VA_ARGS__); \ 353 } while (0) 354 355 #define pr_verbose_init(opts, fmt, ...) \ 356 do { \ 357 if (opt_get(opts, verbose)) \ 358 pr_info(fmt, ##__VA_ARGS__); \ 359 } while (0) 360 361 /* Parameters that are useful for debugging, but should always be compiled in: */ 362 #define BCH_DEBUG_PARAMS_ALWAYS() \ 363 BCH_DEBUG_PARAM(key_merging_disabled, \ 364 "Disables merging of extents") \ 365 BCH_DEBUG_PARAM(btree_node_merging_disabled, \ 366 "Disables merging of btree nodes") \ 367 BCH_DEBUG_PARAM(btree_gc_always_rewrite, \ 368 "Causes mark and sweep to compact and rewrite every " \ 369 "btree node it traverses") \ 370 BCH_DEBUG_PARAM(btree_gc_rewrite_disabled, \ 371 "Disables rewriting of btree nodes during mark and sweep")\ 372 BCH_DEBUG_PARAM(btree_shrinker_disabled, \ 373 "Disables the shrinker callback for the btree node cache")\ 374 BCH_DEBUG_PARAM(verify_btree_ondisk, \ 375 "Reread btree nodes at various points to verify the " \ 376 "mergesort in the read path against modifications " \ 377 "done in memory") \ 378 BCH_DEBUG_PARAM(verify_all_btree_replicas, \ 379 "When reading btree nodes, read all replicas and " \ 380 "compare them") \ 381 BCH_DEBUG_PARAM(backpointers_no_use_write_buffer, \ 382 "Don't use the write buffer for backpointers, enabling "\ 383 "extra runtime checks") 384 385 /* Parameters that should only be compiled in debug mode: */ 386 #define BCH_DEBUG_PARAMS_DEBUG() \ 387 BCH_DEBUG_PARAM(expensive_debug_checks, \ 388 "Enables various runtime debugging checks that " \ 389 "significantly affect performance") \ 390 BCH_DEBUG_PARAM(debug_check_iterators, \ 391 "Enables extra verification for btree iterators") \ 392 BCH_DEBUG_PARAM(debug_check_btree_accounting, \ 393 "Verify btree accounting for keys within a node") \ 394 BCH_DEBUG_PARAM(journal_seq_verify, \ 395 "Store the journal sequence number in the version " \ 396 "number of every btree key, and verify that btree " \ 397 "update ordering is preserved during recovery") \ 398 BCH_DEBUG_PARAM(inject_invalid_keys, \ 399 "Store the journal sequence number in the version " \ 400 "number of every btree key, and verify that btree " \ 401 "update ordering is preserved during recovery") \ 402 BCH_DEBUG_PARAM(test_alloc_startup, \ 403 "Force allocator startup to use the slowpath where it" \ 404 "can't find enough free buckets without invalidating" \ 405 "cached data") \ 406 BCH_DEBUG_PARAM(force_reconstruct_read, \ 407 "Force reads to use the reconstruct path, when reading" \ 408 "from erasure coded extents") \ 409 BCH_DEBUG_PARAM(test_restart_gc, \ 410 "Test restarting mark and sweep gc when bucket gens change") 411 412 #define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG() 413 414 #ifdef CONFIG_BCACHEFS_DEBUG 415 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL() 416 #else 417 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS() 418 #endif 419 420 #define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name; 421 BCH_DEBUG_PARAMS() 422 #undef BCH_DEBUG_PARAM 423 424 #ifndef CONFIG_BCACHEFS_DEBUG 425 #define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name; 426 BCH_DEBUG_PARAMS_DEBUG() 427 #undef BCH_DEBUG_PARAM 428 #endif 429 430 #define BCH_TIME_STATS() \ 431 x(btree_node_mem_alloc) \ 432 x(btree_node_split) \ 433 x(btree_node_compact) \ 434 x(btree_node_merge) \ 435 x(btree_node_sort) \ 436 x(btree_node_read) \ 437 x(btree_node_read_done) \ 438 x(btree_interior_update_foreground) \ 439 x(btree_interior_update_total) \ 440 x(btree_gc) \ 441 x(data_write) \ 442 x(data_read) \ 443 x(data_promote) \ 444 x(journal_flush_write) \ 445 x(journal_noflush_write) \ 446 x(journal_flush_seq) \ 447 x(blocked_journal_low_on_space) \ 448 x(blocked_journal_low_on_pin) \ 449 x(blocked_journal_max_in_flight) \ 450 x(blocked_allocate) \ 451 x(blocked_allocate_open_bucket) \ 452 x(blocked_write_buffer_full) \ 453 x(nocow_lock_contended) 454 455 enum bch_time_stats { 456 #define x(name) BCH_TIME_##name, 457 BCH_TIME_STATS() 458 #undef x 459 BCH_TIME_STAT_NR 460 }; 461 462 #include "alloc_types.h" 463 #include "btree_gc_types.h" 464 #include "btree_types.h" 465 #include "btree_node_scan_types.h" 466 #include "btree_write_buffer_types.h" 467 #include "buckets_types.h" 468 #include "buckets_waiting_for_journal_types.h" 469 #include "clock_types.h" 470 #include "disk_groups_types.h" 471 #include "ec_types.h" 472 #include "journal_types.h" 473 #include "keylist_types.h" 474 #include "quota_types.h" 475 #include "rebalance_types.h" 476 #include "replicas_types.h" 477 #include "sb-members_types.h" 478 #include "subvolume_types.h" 479 #include "super_types.h" 480 #include "thread_with_file_types.h" 481 482 /* Number of nodes btree coalesce will try to coalesce at once */ 483 #define GC_MERGE_NODES 4U 484 485 /* Maximum number of nodes we might need to allocate atomically: */ 486 #define BTREE_RESERVE_MAX (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1)) 487 488 /* Size of the freelist we allocate btree nodes from: */ 489 #define BTREE_NODE_RESERVE (BTREE_RESERVE_MAX * 4) 490 491 #define BTREE_NODE_OPEN_BUCKET_RESERVE (BTREE_RESERVE_MAX * BCH_REPLICAS_MAX) 492 493 struct btree; 494 495 struct io_count { 496 u64 sectors[2][BCH_DATA_NR]; 497 }; 498 499 struct discard_in_flight { 500 bool in_progress:1; 501 u64 bucket:63; 502 }; 503 504 struct bch_dev { 505 struct kobject kobj; 506 #ifdef CONFIG_BCACHEFS_DEBUG 507 atomic_long_t ref; 508 bool dying; 509 unsigned long last_put; 510 #else 511 struct percpu_ref ref; 512 #endif 513 struct completion ref_completion; 514 struct percpu_ref io_ref; 515 struct completion io_ref_completion; 516 517 struct bch_fs *fs; 518 519 u8 dev_idx; 520 /* 521 * Cached version of this device's member info from superblock 522 * Committed by bch2_write_super() -> bch_fs_mi_update() 523 */ 524 struct bch_member_cpu mi; 525 atomic64_t errors[BCH_MEMBER_ERROR_NR]; 526 527 __uuid_t uuid; 528 char name[BDEVNAME_SIZE]; 529 530 struct bch_sb_handle disk_sb; 531 struct bch_sb *sb_read_scratch; 532 int sb_write_error; 533 dev_t dev; 534 atomic_t flush_seq; 535 536 struct bch_devs_mask self; 537 538 /* 539 * Buckets: 540 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and 541 * gc_gens_lock, for device resize - holding any is sufficient for 542 * access: Or rcu_read_lock(), but only for dev_ptr_stale(): 543 */ 544 struct bucket_array __rcu *buckets_gc; 545 struct bucket_gens __rcu *bucket_gens; 546 u8 *oldest_gen; 547 unsigned long *buckets_nouse; 548 struct rw_semaphore bucket_lock; 549 550 struct bch_dev_usage __percpu *usage; 551 552 /* Allocator: */ 553 u64 new_fs_bucket_idx; 554 u64 alloc_cursor[3]; 555 556 unsigned nr_open_buckets; 557 unsigned nr_btree_reserve; 558 559 size_t inc_gen_needs_gc; 560 size_t inc_gen_really_needs_gc; 561 size_t buckets_waiting_on_journal; 562 563 struct work_struct invalidate_work; 564 struct work_struct discard_work; 565 struct mutex discard_buckets_in_flight_lock; 566 DARRAY(struct discard_in_flight) discard_buckets_in_flight; 567 struct work_struct discard_fast_work; 568 569 atomic64_t rebalance_work; 570 571 struct journal_device journal; 572 u64 prev_journal_sector; 573 574 struct work_struct io_error_work; 575 576 /* The rest of this all shows up in sysfs */ 577 atomic64_t cur_latency[2]; 578 struct bch2_time_stats_quantiles io_latency[2]; 579 580 #define CONGESTED_MAX 1024 581 atomic_t congested; 582 u64 congested_last; 583 584 struct io_count __percpu *io_done; 585 }; 586 587 /* 588 * initial_gc_unfixed 589 * error 590 * topology error 591 */ 592 593 #define BCH_FS_FLAGS() \ 594 x(new_fs) \ 595 x(started) \ 596 x(btree_running) \ 597 x(accounting_replay_done) \ 598 x(may_go_rw) \ 599 x(rw) \ 600 x(was_rw) \ 601 x(stopping) \ 602 x(emergency_ro) \ 603 x(going_ro) \ 604 x(write_disable_complete) \ 605 x(clean_shutdown) \ 606 x(fsck_running) \ 607 x(initial_gc_unfixed) \ 608 x(need_delete_dead_snapshots) \ 609 x(error) \ 610 x(topology_error) \ 611 x(errors_fixed) \ 612 x(errors_not_fixed) \ 613 x(no_invalid_checks) 614 615 enum bch_fs_flags { 616 #define x(n) BCH_FS_##n, 617 BCH_FS_FLAGS() 618 #undef x 619 }; 620 621 struct btree_debug { 622 unsigned id; 623 }; 624 625 #define BCH_TRANSACTIONS_NR 128 626 627 struct btree_transaction_stats { 628 struct bch2_time_stats duration; 629 struct bch2_time_stats lock_hold_times; 630 struct mutex lock; 631 unsigned nr_max_paths; 632 unsigned journal_entries_size; 633 unsigned max_mem; 634 char *max_paths_text; 635 }; 636 637 struct bch_fs_pcpu { 638 u64 sectors_available; 639 }; 640 641 struct journal_seq_blacklist_table { 642 size_t nr; 643 struct journal_seq_blacklist_table_entry { 644 u64 start; 645 u64 end; 646 bool dirty; 647 } entries[]; 648 }; 649 650 struct journal_keys { 651 /* must match layout in darray_types.h */ 652 size_t nr, size; 653 struct journal_key { 654 u64 journal_seq; 655 u32 journal_offset; 656 enum btree_id btree_id:8; 657 unsigned level:8; 658 bool allocated; 659 bool overwritten; 660 struct bkey_i *k; 661 } *data; 662 /* 663 * Gap buffer: instead of all the empty space in the array being at the 664 * end of the buffer - from @nr to @size - the empty space is at @gap. 665 * This means that sequential insertions are O(n) instead of O(n^2). 666 */ 667 size_t gap; 668 atomic_t ref; 669 bool initial_ref_held; 670 }; 671 672 struct btree_trans_buf { 673 struct btree_trans *trans; 674 }; 675 676 #define BCACHEFS_ROOT_SUBVOL_INUM \ 677 ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO }) 678 679 #define BCH_WRITE_REFS() \ 680 x(trans) \ 681 x(write) \ 682 x(promote) \ 683 x(node_rewrite) \ 684 x(stripe_create) \ 685 x(stripe_delete) \ 686 x(reflink) \ 687 x(fallocate) \ 688 x(fsync) \ 689 x(dio_write) \ 690 x(discard) \ 691 x(discard_fast) \ 692 x(invalidate) \ 693 x(delete_dead_snapshots) \ 694 x(gc_gens) \ 695 x(snapshot_delete_pagecache) \ 696 x(sysfs) \ 697 x(btree_write_buffer) 698 699 enum bch_write_ref { 700 #define x(n) BCH_WRITE_REF_##n, 701 BCH_WRITE_REFS() 702 #undef x 703 BCH_WRITE_REF_NR, 704 }; 705 706 struct bch_fs { 707 struct closure cl; 708 709 struct list_head list; 710 struct kobject kobj; 711 struct kobject counters_kobj; 712 struct kobject internal; 713 struct kobject opts_dir; 714 struct kobject time_stats; 715 unsigned long flags; 716 717 int minor; 718 struct device *chardev; 719 struct super_block *vfs_sb; 720 dev_t dev; 721 char name[40]; 722 struct stdio_redirect *stdio; 723 struct task_struct *stdio_filter; 724 725 /* ro/rw, add/remove/resize devices: */ 726 struct rw_semaphore state_lock; 727 728 /* Counts outstanding writes, for clean transition to read-only */ 729 #ifdef BCH_WRITE_REF_DEBUG 730 atomic_long_t writes[BCH_WRITE_REF_NR]; 731 #else 732 struct percpu_ref writes; 733 #endif 734 /* 735 * Analagous to c->writes, for asynchronous ops that don't necessarily 736 * need fs to be read-write 737 */ 738 refcount_t ro_ref; 739 wait_queue_head_t ro_ref_wait; 740 741 struct work_struct read_only_work; 742 743 struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX]; 744 745 struct bch_accounting_mem accounting; 746 747 struct bch_replicas_cpu replicas; 748 struct bch_replicas_cpu replicas_gc; 749 struct mutex replicas_gc_lock; 750 751 struct journal_entry_res btree_root_journal_res; 752 struct journal_entry_res clock_journal_res; 753 754 struct bch_disk_groups_cpu __rcu *disk_groups; 755 756 struct bch_opts opts; 757 758 /* Updated by bch2_sb_update():*/ 759 struct { 760 __uuid_t uuid; 761 __uuid_t user_uuid; 762 763 u16 version; 764 u16 version_min; 765 u16 version_upgrade_complete; 766 767 u8 nr_devices; 768 u8 clean; 769 770 u8 encryption_type; 771 772 u64 time_base_lo; 773 u32 time_base_hi; 774 unsigned time_units_per_sec; 775 unsigned nsec_per_time_unit; 776 u64 features; 777 u64 compat; 778 unsigned long errors_silent[BITS_TO_LONGS(BCH_SB_ERR_MAX)]; 779 u64 btrees_lost_data; 780 } sb; 781 782 783 struct bch_sb_handle disk_sb; 784 785 unsigned short block_bits; /* ilog2(block_size) */ 786 787 u16 btree_foreground_merge_threshold; 788 789 struct closure sb_write; 790 struct mutex sb_lock; 791 792 /* snapshot.c: */ 793 struct snapshot_table __rcu *snapshots; 794 struct mutex snapshot_table_lock; 795 struct rw_semaphore snapshot_create_lock; 796 797 struct work_struct snapshot_delete_work; 798 struct work_struct snapshot_wait_for_pagecache_and_delete_work; 799 snapshot_id_list snapshots_unlinked; 800 struct mutex snapshots_unlinked_lock; 801 802 /* BTREE CACHE */ 803 struct bio_set btree_bio; 804 struct workqueue_struct *btree_read_complete_wq; 805 struct workqueue_struct *btree_write_submit_wq; 806 807 struct btree_root btree_roots_known[BTREE_ID_NR]; 808 DARRAY(struct btree_root) btree_roots_extra; 809 struct mutex btree_root_lock; 810 811 struct btree_cache btree_cache; 812 813 /* 814 * Cache of allocated btree nodes - if we allocate a btree node and 815 * don't use it, if we free it that space can't be reused until going 816 * _all_ the way through the allocator (which exposes us to a livelock 817 * when allocating btree reserves fail halfway through) - instead, we 818 * can stick them here: 819 */ 820 struct btree_alloc btree_reserve_cache[BTREE_NODE_RESERVE * 2]; 821 unsigned btree_reserve_cache_nr; 822 struct mutex btree_reserve_cache_lock; 823 824 mempool_t btree_interior_update_pool; 825 struct list_head btree_interior_update_list; 826 struct list_head btree_interior_updates_unwritten; 827 struct mutex btree_interior_update_lock; 828 struct closure_waitlist btree_interior_update_wait; 829 830 struct workqueue_struct *btree_interior_update_worker; 831 struct work_struct btree_interior_update_work; 832 833 struct workqueue_struct *btree_node_rewrite_worker; 834 835 struct list_head pending_node_rewrites; 836 struct mutex pending_node_rewrites_lock; 837 838 /* btree_io.c: */ 839 spinlock_t btree_write_error_lock; 840 struct btree_write_stats { 841 atomic64_t nr; 842 atomic64_t bytes; 843 } btree_write_stats[BTREE_WRITE_TYPE_NR]; 844 845 /* btree_iter.c: */ 846 struct seqmutex btree_trans_lock; 847 struct list_head btree_trans_list; 848 mempool_t btree_trans_pool; 849 mempool_t btree_trans_mem_pool; 850 struct btree_trans_buf __percpu *btree_trans_bufs; 851 852 struct srcu_struct btree_trans_barrier; 853 bool btree_trans_barrier_initialized; 854 855 struct btree_key_cache btree_key_cache; 856 unsigned btree_key_cache_btrees; 857 858 struct btree_write_buffer btree_write_buffer; 859 860 struct workqueue_struct *btree_update_wq; 861 struct workqueue_struct *btree_io_complete_wq; 862 /* copygc needs its own workqueue for index updates.. */ 863 struct workqueue_struct *copygc_wq; 864 /* 865 * Use a dedicated wq for write ref holder tasks. Required to avoid 866 * dependency problems with other wq tasks that can block on ref 867 * draining, such as read-only transition. 868 */ 869 struct workqueue_struct *write_ref_wq; 870 871 /* ALLOCATION */ 872 struct bch_devs_mask rw_devs[BCH_DATA_NR]; 873 874 u64 capacity; /* sectors */ 875 u64 reserved; /* sectors */ 876 877 /* 878 * When capacity _decreases_ (due to a disk being removed), we 879 * increment capacity_gen - this invalidates outstanding reservations 880 * and forces them to be revalidated 881 */ 882 u32 capacity_gen; 883 unsigned bucket_size_max; 884 885 atomic64_t sectors_available; 886 struct mutex sectors_available_lock; 887 888 struct bch_fs_pcpu __percpu *pcpu; 889 890 struct percpu_rw_semaphore mark_lock; 891 892 seqcount_t usage_lock; 893 struct bch_fs_usage_base __percpu *usage; 894 u64 __percpu *online_reserved; 895 896 unsigned long allocator_last_stuck; 897 898 struct io_clock io_clock[2]; 899 900 /* JOURNAL SEQ BLACKLIST */ 901 struct journal_seq_blacklist_table * 902 journal_seq_blacklist_table; 903 904 /* ALLOCATOR */ 905 spinlock_t freelist_lock; 906 struct closure_waitlist freelist_wait; 907 908 open_bucket_idx_t open_buckets_freelist; 909 open_bucket_idx_t open_buckets_nr_free; 910 struct closure_waitlist open_buckets_wait; 911 struct open_bucket open_buckets[OPEN_BUCKETS_COUNT]; 912 open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT]; 913 914 open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT]; 915 open_bucket_idx_t open_buckets_partial_nr; 916 917 struct write_point btree_write_point; 918 struct write_point rebalance_write_point; 919 920 struct write_point write_points[WRITE_POINT_MAX]; 921 struct hlist_head write_points_hash[WRITE_POINT_HASH_NR]; 922 struct mutex write_points_hash_lock; 923 unsigned write_points_nr; 924 925 struct buckets_waiting_for_journal buckets_waiting_for_journal; 926 927 /* GARBAGE COLLECTION */ 928 struct work_struct gc_gens_work; 929 unsigned long gc_count; 930 931 enum btree_id gc_gens_btree; 932 struct bpos gc_gens_pos; 933 934 /* 935 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos] 936 * has been marked by GC. 937 * 938 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.) 939 * 940 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread 941 * can read without a lock. 942 */ 943 seqcount_t gc_pos_lock; 944 struct gc_pos gc_pos; 945 946 /* 947 * The allocation code needs gc_mark in struct bucket to be correct, but 948 * it's not while a gc is in progress. 949 */ 950 struct rw_semaphore gc_lock; 951 struct mutex gc_gens_lock; 952 953 /* IO PATH */ 954 struct semaphore io_in_flight; 955 struct bio_set bio_read; 956 struct bio_set bio_read_split; 957 struct bio_set bio_write; 958 struct bio_set replica_set; 959 struct mutex bio_bounce_pages_lock; 960 mempool_t bio_bounce_pages; 961 struct bucket_nocow_lock_table 962 nocow_locks; 963 struct rhashtable promote_table; 964 965 mempool_t compression_bounce[2]; 966 mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR]; 967 mempool_t decompress_workspace; 968 size_t zstd_workspace_size; 969 970 struct crypto_shash *sha256; 971 struct crypto_sync_skcipher *chacha20; 972 struct crypto_shash *poly1305; 973 974 atomic64_t key_version; 975 976 mempool_t large_bkey_pool; 977 978 /* MOVE.C */ 979 struct list_head moving_context_list; 980 struct mutex moving_context_lock; 981 982 /* REBALANCE */ 983 struct bch_fs_rebalance rebalance; 984 985 /* COPYGC */ 986 struct task_struct *copygc_thread; 987 struct write_point copygc_write_point; 988 s64 copygc_wait_at; 989 s64 copygc_wait; 990 bool copygc_running; 991 wait_queue_head_t copygc_running_wq; 992 993 /* STRIPES: */ 994 GENRADIX(struct stripe) stripes; 995 GENRADIX(struct gc_stripe) gc_stripes; 996 997 struct hlist_head ec_stripes_new[32]; 998 spinlock_t ec_stripes_new_lock; 999 1000 ec_stripes_heap ec_stripes_heap; 1001 struct mutex ec_stripes_heap_lock; 1002 1003 /* ERASURE CODING */ 1004 struct list_head ec_stripe_head_list; 1005 struct mutex ec_stripe_head_lock; 1006 1007 struct list_head ec_stripe_new_list; 1008 struct mutex ec_stripe_new_lock; 1009 wait_queue_head_t ec_stripe_new_wait; 1010 1011 struct work_struct ec_stripe_create_work; 1012 u64 ec_stripe_hint; 1013 1014 struct work_struct ec_stripe_delete_work; 1015 1016 struct bio_set ec_bioset; 1017 1018 /* REFLINK */ 1019 reflink_gc_table reflink_gc_table; 1020 size_t reflink_gc_nr; 1021 1022 /* fs.c */ 1023 struct list_head vfs_inodes_list; 1024 struct mutex vfs_inodes_lock; 1025 1026 /* VFS IO PATH - fs-io.c */ 1027 struct bio_set writepage_bioset; 1028 struct bio_set dio_write_bioset; 1029 struct bio_set dio_read_bioset; 1030 struct bio_set nocow_flush_bioset; 1031 1032 /* QUOTAS */ 1033 struct bch_memquota_type quotas[QTYP_NR]; 1034 1035 /* RECOVERY */ 1036 u64 journal_replay_seq_start; 1037 u64 journal_replay_seq_end; 1038 /* 1039 * Two different uses: 1040 * "Has this fsck pass?" - i.e. should this type of error be an 1041 * emergency read-only 1042 * And, in certain situations fsck will rewind to an earlier pass: used 1043 * for signaling to the toplevel code which pass we want to run now. 1044 */ 1045 enum bch_recovery_pass curr_recovery_pass; 1046 /* bitmap of explicitly enabled recovery passes: */ 1047 u64 recovery_passes_explicit; 1048 /* bitmask of recovery passes that we actually ran */ 1049 u64 recovery_passes_complete; 1050 /* never rewinds version of curr_recovery_pass */ 1051 enum bch_recovery_pass recovery_pass_done; 1052 struct semaphore online_fsck_mutex; 1053 1054 /* DEBUG JUNK */ 1055 struct dentry *fs_debug_dir; 1056 struct dentry *btree_debug_dir; 1057 struct btree_debug btree_debug[BTREE_ID_NR]; 1058 struct btree *verify_data; 1059 struct btree_node *verify_ondisk; 1060 struct mutex verify_lock; 1061 1062 u64 *unused_inode_hints; 1063 unsigned inode_shard_bits; 1064 1065 /* 1066 * A btree node on disk could have too many bsets for an iterator to fit 1067 * on the stack - have to dynamically allocate them 1068 */ 1069 mempool_t fill_iter; 1070 1071 mempool_t btree_bounce_pool; 1072 1073 struct journal journal; 1074 GENRADIX(struct journal_replay *) journal_entries; 1075 u64 journal_entries_base_seq; 1076 struct journal_keys journal_keys; 1077 struct list_head journal_iters; 1078 1079 struct find_btree_nodes found_btree_nodes; 1080 1081 u64 last_bucket_seq_cleanup; 1082 1083 u64 counters_on_mount[BCH_COUNTER_NR]; 1084 u64 __percpu *counters; 1085 1086 unsigned copy_gc_enabled:1; 1087 bool promote_whole_extents; 1088 1089 struct bch2_time_stats times[BCH_TIME_STAT_NR]; 1090 1091 struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR]; 1092 1093 /* ERRORS */ 1094 struct list_head fsck_error_msgs; 1095 struct mutex fsck_error_msgs_lock; 1096 bool fsck_alloc_msgs_err; 1097 1098 bch_sb_errors_cpu fsck_error_counts; 1099 struct mutex fsck_error_counts_lock; 1100 }; 1101 1102 extern struct wait_queue_head bch2_read_only_wait; 1103 1104 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref) 1105 { 1106 #ifdef BCH_WRITE_REF_DEBUG 1107 atomic_long_inc(&c->writes[ref]); 1108 #else 1109 percpu_ref_get(&c->writes); 1110 #endif 1111 } 1112 1113 static inline bool __bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1114 { 1115 #ifdef BCH_WRITE_REF_DEBUG 1116 return !test_bit(BCH_FS_going_ro, &c->flags) && 1117 atomic_long_inc_not_zero(&c->writes[ref]); 1118 #else 1119 return percpu_ref_tryget(&c->writes); 1120 #endif 1121 } 1122 1123 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1124 { 1125 #ifdef BCH_WRITE_REF_DEBUG 1126 return !test_bit(BCH_FS_going_ro, &c->flags) && 1127 atomic_long_inc_not_zero(&c->writes[ref]); 1128 #else 1129 return percpu_ref_tryget_live(&c->writes); 1130 #endif 1131 } 1132 1133 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref) 1134 { 1135 #ifdef BCH_WRITE_REF_DEBUG 1136 long v = atomic_long_dec_return(&c->writes[ref]); 1137 1138 BUG_ON(v < 0); 1139 if (v) 1140 return; 1141 for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) 1142 if (atomic_long_read(&c->writes[i])) 1143 return; 1144 1145 set_bit(BCH_FS_write_disable_complete, &c->flags); 1146 wake_up(&bch2_read_only_wait); 1147 #else 1148 percpu_ref_put(&c->writes); 1149 #endif 1150 } 1151 1152 static inline bool bch2_ro_ref_tryget(struct bch_fs *c) 1153 { 1154 if (test_bit(BCH_FS_stopping, &c->flags)) 1155 return false; 1156 1157 return refcount_inc_not_zero(&c->ro_ref); 1158 } 1159 1160 static inline void bch2_ro_ref_put(struct bch_fs *c) 1161 { 1162 if (refcount_dec_and_test(&c->ro_ref)) 1163 wake_up(&c->ro_ref_wait); 1164 } 1165 1166 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) 1167 { 1168 #ifndef NO_BCACHEFS_FS 1169 if (c->vfs_sb) 1170 c->vfs_sb->s_bdi->ra_pages = ra_pages; 1171 #endif 1172 } 1173 1174 static inline unsigned bucket_bytes(const struct bch_dev *ca) 1175 { 1176 return ca->mi.bucket_size << 9; 1177 } 1178 1179 static inline unsigned block_bytes(const struct bch_fs *c) 1180 { 1181 return c->opts.block_size; 1182 } 1183 1184 static inline unsigned block_sectors(const struct bch_fs *c) 1185 { 1186 return c->opts.block_size >> 9; 1187 } 1188 1189 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree) 1190 { 1191 return c->btree_key_cache_btrees & (1U << btree); 1192 } 1193 1194 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time) 1195 { 1196 struct timespec64 t; 1197 s32 rem; 1198 1199 time += c->sb.time_base_lo; 1200 1201 t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem); 1202 t.tv_nsec = rem * c->sb.nsec_per_time_unit; 1203 return t; 1204 } 1205 1206 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts) 1207 { 1208 return (ts.tv_sec * c->sb.time_units_per_sec + 1209 (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo; 1210 } 1211 1212 static inline s64 bch2_current_time(const struct bch_fs *c) 1213 { 1214 struct timespec64 now; 1215 1216 ktime_get_coarse_real_ts64(&now); 1217 return timespec_to_bch2_time(c, now); 1218 } 1219 1220 static inline u64 bch2_current_io_time(const struct bch_fs *c, int rw) 1221 { 1222 return max(1ULL, (u64) atomic64_read(&c->io_clock[rw].now) & LRU_TIME_MAX); 1223 } 1224 1225 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c) 1226 { 1227 struct stdio_redirect *stdio = c->stdio; 1228 1229 if (c->stdio_filter && c->stdio_filter != current) 1230 stdio = NULL; 1231 return stdio; 1232 } 1233 1234 static inline unsigned metadata_replicas_required(struct bch_fs *c) 1235 { 1236 return min(c->opts.metadata_replicas, 1237 c->opts.metadata_replicas_required); 1238 } 1239 1240 static inline unsigned data_replicas_required(struct bch_fs *c) 1241 { 1242 return min(c->opts.data_replicas, 1243 c->opts.data_replicas_required); 1244 } 1245 1246 #define BKEY_PADDED_ONSTACK(key, pad) \ 1247 struct { struct bkey_i key; __u64 key ## _pad[pad]; } 1248 1249 #endif /* _BCACHEFS_H */ 1250