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 discard_in_flight { 497 bool in_progress:1; 498 u64 bucket:63; 499 }; 500 501 struct bch_dev { 502 struct kobject kobj; 503 #ifdef CONFIG_BCACHEFS_DEBUG 504 atomic_long_t ref; 505 bool dying; 506 unsigned long last_put; 507 #else 508 struct percpu_ref ref; 509 #endif 510 struct completion ref_completion; 511 struct percpu_ref io_ref; 512 struct completion io_ref_completion; 513 514 struct bch_fs *fs; 515 516 u8 dev_idx; 517 /* 518 * Cached version of this device's member info from superblock 519 * Committed by bch2_write_super() -> bch_fs_mi_update() 520 */ 521 struct bch_member_cpu mi; 522 atomic64_t errors[BCH_MEMBER_ERROR_NR]; 523 524 __uuid_t uuid; 525 char name[BDEVNAME_SIZE]; 526 527 struct bch_sb_handle disk_sb; 528 struct bch_sb *sb_read_scratch; 529 int sb_write_error; 530 dev_t dev; 531 atomic_t flush_seq; 532 533 struct bch_devs_mask self; 534 535 /* 536 * Buckets: 537 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and 538 * gc_lock, for device resize - holding any is sufficient for access: 539 * Or rcu_read_lock(), but only for dev_ptr_stale(): 540 */ 541 struct bucket_array __rcu *buckets_gc; 542 struct bucket_gens __rcu *bucket_gens; 543 u8 *oldest_gen; 544 unsigned long *buckets_nouse; 545 struct rw_semaphore bucket_lock; 546 547 struct bch_dev_usage *usage_base; 548 struct bch_dev_usage __percpu *usage[JOURNAL_BUF_NR]; 549 struct bch_dev_usage __percpu *usage_gc; 550 551 /* Allocator: */ 552 u64 new_fs_bucket_idx; 553 u64 alloc_cursor[3]; 554 555 unsigned nr_open_buckets; 556 unsigned nr_btree_reserve; 557 558 size_t inc_gen_needs_gc; 559 size_t inc_gen_really_needs_gc; 560 size_t buckets_waiting_on_journal; 561 562 struct work_struct invalidate_work; 563 struct work_struct discard_work; 564 struct mutex discard_buckets_in_flight_lock; 565 DARRAY(struct discard_in_flight) discard_buckets_in_flight; 566 struct work_struct discard_fast_work; 567 568 atomic64_t rebalance_work; 569 570 struct journal_device journal; 571 u64 prev_journal_sector; 572 573 struct work_struct io_error_work; 574 575 /* The rest of this all shows up in sysfs */ 576 atomic64_t cur_latency[2]; 577 struct bch2_time_stats_quantiles io_latency[2]; 578 579 #define CONGESTED_MAX 1024 580 atomic_t congested; 581 u64 congested_last; 582 583 struct io_count __percpu *io_done; 584 }; 585 586 /* 587 * initial_gc_unfixed 588 * error 589 * topology error 590 */ 591 592 #define BCH_FS_FLAGS() \ 593 x(new_fs) \ 594 x(started) \ 595 x(may_go_rw) \ 596 x(rw) \ 597 x(was_rw) \ 598 x(stopping) \ 599 x(emergency_ro) \ 600 x(going_ro) \ 601 x(write_disable_complete) \ 602 x(clean_shutdown) \ 603 x(fsck_running) \ 604 x(initial_gc_unfixed) \ 605 x(need_delete_dead_snapshots) \ 606 x(error) \ 607 x(topology_error) \ 608 x(errors_fixed) \ 609 x(errors_not_fixed) \ 610 x(no_invalid_checks) 611 612 enum bch_fs_flags { 613 #define x(n) BCH_FS_##n, 614 BCH_FS_FLAGS() 615 #undef x 616 }; 617 618 struct btree_debug { 619 unsigned id; 620 }; 621 622 #define BCH_TRANSACTIONS_NR 128 623 624 struct btree_transaction_stats { 625 struct bch2_time_stats duration; 626 struct bch2_time_stats lock_hold_times; 627 struct mutex lock; 628 unsigned nr_max_paths; 629 unsigned journal_entries_size; 630 unsigned max_mem; 631 char *max_paths_text; 632 }; 633 634 struct bch_fs_pcpu { 635 u64 sectors_available; 636 }; 637 638 struct journal_seq_blacklist_table { 639 size_t nr; 640 struct journal_seq_blacklist_table_entry { 641 u64 start; 642 u64 end; 643 bool dirty; 644 } entries[]; 645 }; 646 647 struct journal_keys { 648 /* must match layout in darray_types.h */ 649 size_t nr, size; 650 struct journal_key { 651 u64 journal_seq; 652 u32 journal_offset; 653 enum btree_id btree_id:8; 654 unsigned level:8; 655 bool allocated; 656 bool overwritten; 657 struct bkey_i *k; 658 } *data; 659 /* 660 * Gap buffer: instead of all the empty space in the array being at the 661 * end of the buffer - from @nr to @size - the empty space is at @gap. 662 * This means that sequential insertions are O(n) instead of O(n^2). 663 */ 664 size_t gap; 665 atomic_t ref; 666 bool initial_ref_held; 667 }; 668 669 struct btree_trans_buf { 670 struct btree_trans *trans; 671 }; 672 673 #define REPLICAS_DELTA_LIST_MAX (1U << 16) 674 675 #define BCACHEFS_ROOT_SUBVOL_INUM \ 676 ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO }) 677 678 #define BCH_WRITE_REFS() \ 679 x(trans) \ 680 x(write) \ 681 x(promote) \ 682 x(node_rewrite) \ 683 x(stripe_create) \ 684 x(stripe_delete) \ 685 x(reflink) \ 686 x(fallocate) \ 687 x(fsync) \ 688 x(dio_write) \ 689 x(discard) \ 690 x(discard_fast) \ 691 x(invalidate) \ 692 x(delete_dead_snapshots) \ 693 x(gc_gens) \ 694 x(snapshot_delete_pagecache) \ 695 x(sysfs) \ 696 x(btree_write_buffer) 697 698 enum bch_write_ref { 699 #define x(n) BCH_WRITE_REF_##n, 700 BCH_WRITE_REFS() 701 #undef x 702 BCH_WRITE_REF_NR, 703 }; 704 705 struct bch_fs { 706 struct closure cl; 707 708 struct list_head list; 709 struct kobject kobj; 710 struct kobject counters_kobj; 711 struct kobject internal; 712 struct kobject opts_dir; 713 struct kobject time_stats; 714 unsigned long flags; 715 716 int minor; 717 struct device *chardev; 718 struct super_block *vfs_sb; 719 dev_t dev; 720 char name[40]; 721 struct stdio_redirect *stdio; 722 struct task_struct *stdio_filter; 723 724 /* ro/rw, add/remove/resize devices: */ 725 struct rw_semaphore state_lock; 726 727 /* Counts outstanding writes, for clean transition to read-only */ 728 #ifdef BCH_WRITE_REF_DEBUG 729 atomic_long_t writes[BCH_WRITE_REF_NR]; 730 #else 731 struct percpu_ref writes; 732 #endif 733 /* 734 * Analagous to c->writes, for asynchronous ops that don't necessarily 735 * need fs to be read-write 736 */ 737 refcount_t ro_ref; 738 wait_queue_head_t ro_ref_wait; 739 740 struct work_struct read_only_work; 741 742 struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX]; 743 744 struct bch_replicas_cpu replicas; 745 struct bch_replicas_cpu replicas_gc; 746 struct mutex replicas_gc_lock; 747 mempool_t replicas_delta_pool; 748 749 struct journal_entry_res btree_root_journal_res; 750 struct journal_entry_res replicas_journal_res; 751 struct journal_entry_res clock_journal_res; 752 struct journal_entry_res dev_usage_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 */ 875 876 /* 877 * When capacity _decreases_ (due to a disk being removed), we 878 * increment capacity_gen - this invalidates outstanding reservations 879 * and forces them to be revalidated 880 */ 881 u32 capacity_gen; 882 unsigned bucket_size_max; 883 884 atomic64_t sectors_available; 885 struct mutex sectors_available_lock; 886 887 struct bch_fs_pcpu __percpu *pcpu; 888 889 struct percpu_rw_semaphore mark_lock; 890 891 seqcount_t usage_lock; 892 struct bch_fs_usage *usage_base; 893 struct bch_fs_usage __percpu *usage[JOURNAL_BUF_NR]; 894 struct bch_fs_usage __percpu *usage_gc; 895 u64 __percpu *online_reserved; 896 897 /* single element mempool: */ 898 struct mutex usage_scratch_lock; 899 struct bch_fs_usage_online *usage_scratch; 900 901 struct io_clock io_clock[2]; 902 903 /* JOURNAL SEQ BLACKLIST */ 904 struct journal_seq_blacklist_table * 905 journal_seq_blacklist_table; 906 907 /* ALLOCATOR */ 908 spinlock_t freelist_lock; 909 struct closure_waitlist freelist_wait; 910 911 open_bucket_idx_t open_buckets_freelist; 912 open_bucket_idx_t open_buckets_nr_free; 913 struct closure_waitlist open_buckets_wait; 914 struct open_bucket open_buckets[OPEN_BUCKETS_COUNT]; 915 open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT]; 916 917 open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT]; 918 open_bucket_idx_t open_buckets_partial_nr; 919 920 struct write_point btree_write_point; 921 struct write_point rebalance_write_point; 922 923 struct write_point write_points[WRITE_POINT_MAX]; 924 struct hlist_head write_points_hash[WRITE_POINT_HASH_NR]; 925 struct mutex write_points_hash_lock; 926 unsigned write_points_nr; 927 928 struct buckets_waiting_for_journal buckets_waiting_for_journal; 929 930 /* GARBAGE COLLECTION */ 931 struct work_struct gc_gens_work; 932 unsigned long gc_count; 933 934 enum btree_id gc_gens_btree; 935 struct bpos gc_gens_pos; 936 937 /* 938 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos] 939 * has been marked by GC. 940 * 941 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.) 942 * 943 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread 944 * can read without a lock. 945 */ 946 seqcount_t gc_pos_lock; 947 struct gc_pos gc_pos; 948 949 /* 950 * The allocation code needs gc_mark in struct bucket to be correct, but 951 * it's not while a gc is in progress. 952 */ 953 struct rw_semaphore gc_lock; 954 struct mutex gc_gens_lock; 955 956 /* IO PATH */ 957 struct semaphore io_in_flight; 958 struct bio_set bio_read; 959 struct bio_set bio_read_split; 960 struct bio_set bio_write; 961 struct bio_set replica_set; 962 struct mutex bio_bounce_pages_lock; 963 mempool_t bio_bounce_pages; 964 struct bucket_nocow_lock_table 965 nocow_locks; 966 struct rhashtable promote_table; 967 968 mempool_t compression_bounce[2]; 969 mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR]; 970 mempool_t decompress_workspace; 971 size_t zstd_workspace_size; 972 973 struct crypto_shash *sha256; 974 struct crypto_sync_skcipher *chacha20; 975 struct crypto_shash *poly1305; 976 977 atomic64_t key_version; 978 979 mempool_t large_bkey_pool; 980 981 /* MOVE.C */ 982 struct list_head moving_context_list; 983 struct mutex moving_context_lock; 984 985 /* REBALANCE */ 986 struct bch_fs_rebalance rebalance; 987 988 /* COPYGC */ 989 struct task_struct *copygc_thread; 990 struct write_point copygc_write_point; 991 s64 copygc_wait_at; 992 s64 copygc_wait; 993 bool copygc_running; 994 wait_queue_head_t copygc_running_wq; 995 996 /* STRIPES: */ 997 GENRADIX(struct stripe) stripes; 998 GENRADIX(struct gc_stripe) gc_stripes; 999 1000 struct hlist_head ec_stripes_new[32]; 1001 spinlock_t ec_stripes_new_lock; 1002 1003 ec_stripes_heap ec_stripes_heap; 1004 struct mutex ec_stripes_heap_lock; 1005 1006 /* ERASURE CODING */ 1007 struct list_head ec_stripe_head_list; 1008 struct mutex ec_stripe_head_lock; 1009 1010 struct list_head ec_stripe_new_list; 1011 struct mutex ec_stripe_new_lock; 1012 wait_queue_head_t ec_stripe_new_wait; 1013 1014 struct work_struct ec_stripe_create_work; 1015 u64 ec_stripe_hint; 1016 1017 struct work_struct ec_stripe_delete_work; 1018 1019 struct bio_set ec_bioset; 1020 1021 /* REFLINK */ 1022 reflink_gc_table reflink_gc_table; 1023 size_t reflink_gc_nr; 1024 1025 /* fs.c */ 1026 struct list_head vfs_inodes_list; 1027 struct mutex vfs_inodes_lock; 1028 1029 /* VFS IO PATH - fs-io.c */ 1030 struct bio_set writepage_bioset; 1031 struct bio_set dio_write_bioset; 1032 struct bio_set dio_read_bioset; 1033 struct bio_set nocow_flush_bioset; 1034 1035 /* QUOTAS */ 1036 struct bch_memquota_type quotas[QTYP_NR]; 1037 1038 /* RECOVERY */ 1039 u64 journal_replay_seq_start; 1040 u64 journal_replay_seq_end; 1041 /* 1042 * Two different uses: 1043 * "Has this fsck pass?" - i.e. should this type of error be an 1044 * emergency read-only 1045 * And, in certain situations fsck will rewind to an earlier pass: used 1046 * for signaling to the toplevel code which pass we want to run now. 1047 */ 1048 enum bch_recovery_pass curr_recovery_pass; 1049 /* bitmap of explicitly enabled recovery passes: */ 1050 u64 recovery_passes_explicit; 1051 /* bitmask of recovery passes that we actually ran */ 1052 u64 recovery_passes_complete; 1053 /* never rewinds version of curr_recovery_pass */ 1054 enum bch_recovery_pass recovery_pass_done; 1055 struct semaphore online_fsck_mutex; 1056 1057 /* DEBUG JUNK */ 1058 struct dentry *fs_debug_dir; 1059 struct dentry *btree_debug_dir; 1060 struct btree_debug btree_debug[BTREE_ID_NR]; 1061 struct btree *verify_data; 1062 struct btree_node *verify_ondisk; 1063 struct mutex verify_lock; 1064 1065 u64 *unused_inode_hints; 1066 unsigned inode_shard_bits; 1067 1068 /* 1069 * A btree node on disk could have too many bsets for an iterator to fit 1070 * on the stack - have to dynamically allocate them 1071 */ 1072 mempool_t fill_iter; 1073 1074 mempool_t btree_bounce_pool; 1075 1076 struct journal journal; 1077 GENRADIX(struct journal_replay *) journal_entries; 1078 u64 journal_entries_base_seq; 1079 struct journal_keys journal_keys; 1080 struct list_head journal_iters; 1081 1082 struct find_btree_nodes found_btree_nodes; 1083 1084 u64 last_bucket_seq_cleanup; 1085 1086 u64 counters_on_mount[BCH_COUNTER_NR]; 1087 u64 __percpu *counters; 1088 1089 unsigned copy_gc_enabled:1; 1090 bool promote_whole_extents; 1091 1092 struct bch2_time_stats times[BCH_TIME_STAT_NR]; 1093 1094 struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR]; 1095 1096 /* ERRORS */ 1097 struct list_head fsck_error_msgs; 1098 struct mutex fsck_error_msgs_lock; 1099 bool fsck_alloc_msgs_err; 1100 1101 bch_sb_errors_cpu fsck_error_counts; 1102 struct mutex fsck_error_counts_lock; 1103 }; 1104 1105 extern struct wait_queue_head bch2_read_only_wait; 1106 1107 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref) 1108 { 1109 #ifdef BCH_WRITE_REF_DEBUG 1110 atomic_long_inc(&c->writes[ref]); 1111 #else 1112 percpu_ref_get(&c->writes); 1113 #endif 1114 } 1115 1116 static inline bool __bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1117 { 1118 #ifdef BCH_WRITE_REF_DEBUG 1119 return !test_bit(BCH_FS_going_ro, &c->flags) && 1120 atomic_long_inc_not_zero(&c->writes[ref]); 1121 #else 1122 return percpu_ref_tryget(&c->writes); 1123 #endif 1124 } 1125 1126 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1127 { 1128 #ifdef BCH_WRITE_REF_DEBUG 1129 return !test_bit(BCH_FS_going_ro, &c->flags) && 1130 atomic_long_inc_not_zero(&c->writes[ref]); 1131 #else 1132 return percpu_ref_tryget_live(&c->writes); 1133 #endif 1134 } 1135 1136 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref) 1137 { 1138 #ifdef BCH_WRITE_REF_DEBUG 1139 long v = atomic_long_dec_return(&c->writes[ref]); 1140 1141 BUG_ON(v < 0); 1142 if (v) 1143 return; 1144 for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) 1145 if (atomic_long_read(&c->writes[i])) 1146 return; 1147 1148 set_bit(BCH_FS_write_disable_complete, &c->flags); 1149 wake_up(&bch2_read_only_wait); 1150 #else 1151 percpu_ref_put(&c->writes); 1152 #endif 1153 } 1154 1155 static inline bool bch2_ro_ref_tryget(struct bch_fs *c) 1156 { 1157 if (test_bit(BCH_FS_stopping, &c->flags)) 1158 return false; 1159 1160 return refcount_inc_not_zero(&c->ro_ref); 1161 } 1162 1163 static inline void bch2_ro_ref_put(struct bch_fs *c) 1164 { 1165 if (refcount_dec_and_test(&c->ro_ref)) 1166 wake_up(&c->ro_ref_wait); 1167 } 1168 1169 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) 1170 { 1171 #ifndef NO_BCACHEFS_FS 1172 if (c->vfs_sb) 1173 c->vfs_sb->s_bdi->ra_pages = ra_pages; 1174 #endif 1175 } 1176 1177 static inline unsigned bucket_bytes(const struct bch_dev *ca) 1178 { 1179 return ca->mi.bucket_size << 9; 1180 } 1181 1182 static inline unsigned block_bytes(const struct bch_fs *c) 1183 { 1184 return c->opts.block_size; 1185 } 1186 1187 static inline unsigned block_sectors(const struct bch_fs *c) 1188 { 1189 return c->opts.block_size >> 9; 1190 } 1191 1192 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree) 1193 { 1194 return c->btree_key_cache_btrees & (1U << btree); 1195 } 1196 1197 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time) 1198 { 1199 struct timespec64 t; 1200 s32 rem; 1201 1202 time += c->sb.time_base_lo; 1203 1204 t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem); 1205 t.tv_nsec = rem * c->sb.nsec_per_time_unit; 1206 return t; 1207 } 1208 1209 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts) 1210 { 1211 return (ts.tv_sec * c->sb.time_units_per_sec + 1212 (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo; 1213 } 1214 1215 static inline s64 bch2_current_time(const struct bch_fs *c) 1216 { 1217 struct timespec64 now; 1218 1219 ktime_get_coarse_real_ts64(&now); 1220 return timespec_to_bch2_time(c, now); 1221 } 1222 1223 static inline u64 bch2_current_io_time(const struct bch_fs *c, int rw) 1224 { 1225 return max(1ULL, (u64) atomic64_read(&c->io_clock[rw].now) & LRU_TIME_MAX); 1226 } 1227 1228 static inline struct stdio_redirect *bch2_fs_stdio_redirect(struct bch_fs *c) 1229 { 1230 struct stdio_redirect *stdio = c->stdio; 1231 1232 if (c->stdio_filter && c->stdio_filter != current) 1233 stdio = NULL; 1234 return stdio; 1235 } 1236 1237 static inline unsigned metadata_replicas_required(struct bch_fs *c) 1238 { 1239 return min(c->opts.metadata_replicas, 1240 c->opts.metadata_replicas_required); 1241 } 1242 1243 static inline unsigned data_replicas_required(struct bch_fs *c) 1244 { 1245 return min(c->opts.data_replicas, 1246 c->opts.data_replicas_required); 1247 } 1248 1249 #define BKEY_PADDED_ONSTACK(key, pad) \ 1250 struct { struct bkey_i key; __u64 key ## _pad[pad]; } 1251 1252 #endif /* _BCACHEFS_H */ 1253