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/rhashtable.h> 197 #include <linux/rwsem.h> 198 #include <linux/semaphore.h> 199 #include <linux/seqlock.h> 200 #include <linux/shrinker.h> 201 #include <linux/srcu.h> 202 #include <linux/types.h> 203 #include <linux/workqueue.h> 204 #include <linux/zstd.h> 205 206 #include "bcachefs_format.h" 207 #include "errcode.h" 208 #include "fifo.h" 209 #include "nocow_locking_types.h" 210 #include "opts.h" 211 #include "recovery_types.h" 212 #include "sb-errors_types.h" 213 #include "seqmutex.h" 214 #include "util.h" 215 216 #ifdef CONFIG_BCACHEFS_DEBUG 217 #define BCH_WRITE_REF_DEBUG 218 #endif 219 220 #ifndef dynamic_fault 221 #define dynamic_fault(...) 0 222 #endif 223 224 #define race_fault(...) dynamic_fault("bcachefs:race") 225 226 #define trace_and_count(_c, _name, ...) \ 227 do { \ 228 this_cpu_inc((_c)->counters[BCH_COUNTER_##_name]); \ 229 trace_##_name(__VA_ARGS__); \ 230 } while (0) 231 232 #define bch2_fs_init_fault(name) \ 233 dynamic_fault("bcachefs:bch_fs_init:" name) 234 #define bch2_meta_read_fault(name) \ 235 dynamic_fault("bcachefs:meta:read:" name) 236 #define bch2_meta_write_fault(name) \ 237 dynamic_fault("bcachefs:meta:write:" name) 238 239 #ifdef __KERNEL__ 240 #define BCACHEFS_LOG_PREFIX 241 #endif 242 243 #ifdef BCACHEFS_LOG_PREFIX 244 245 #define bch2_log_msg(_c, fmt) "bcachefs (%s): " fmt, ((_c)->name) 246 #define bch2_fmt_dev(_ca, fmt) "bcachefs (%s): " fmt "\n", ((_ca)->name) 247 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "bcachefs (%s sector %llu): " fmt "\n", ((_ca)->name), (_offset) 248 #define bch2_fmt_inum(_c, _inum, fmt) "bcachefs (%s inum %llu): " fmt "\n", ((_c)->name), (_inum) 249 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 250 "bcachefs (%s inum %llu offset %llu): " fmt "\n", ((_c)->name), (_inum), (_offset) 251 252 #else 253 254 #define bch2_log_msg(_c, fmt) fmt 255 #define bch2_fmt_dev(_ca, fmt) "%s: " fmt "\n", ((_ca)->name) 256 #define bch2_fmt_dev_offset(_ca, _offset, fmt) "%s sector %llu: " fmt "\n", ((_ca)->name), (_offset) 257 #define bch2_fmt_inum(_c, _inum, fmt) "inum %llu: " fmt "\n", (_inum) 258 #define bch2_fmt_inum_offset(_c, _inum, _offset, fmt) \ 259 "inum %llu offset %llu: " fmt "\n", (_inum), (_offset) 260 261 #endif 262 263 #define bch2_fmt(_c, fmt) bch2_log_msg(_c, fmt "\n") 264 265 #define bch_info(c, fmt, ...) \ 266 printk(KERN_INFO bch2_fmt(c, fmt), ##__VA_ARGS__) 267 #define bch_notice(c, fmt, ...) \ 268 printk(KERN_NOTICE bch2_fmt(c, fmt), ##__VA_ARGS__) 269 #define bch_warn(c, fmt, ...) \ 270 printk(KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 271 #define bch_warn_ratelimited(c, fmt, ...) \ 272 printk_ratelimited(KERN_WARNING bch2_fmt(c, fmt), ##__VA_ARGS__) 273 274 #define bch_err(c, fmt, ...) \ 275 printk(KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 276 #define bch_err_dev(ca, fmt, ...) \ 277 printk(KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 278 #define bch_err_dev_offset(ca, _offset, fmt, ...) \ 279 printk(KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 280 #define bch_err_inum(c, _inum, fmt, ...) \ 281 printk(KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 282 #define bch_err_inum_offset(c, _inum, _offset, fmt, ...) \ 283 printk(KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 284 285 #define bch_err_ratelimited(c, fmt, ...) \ 286 printk_ratelimited(KERN_ERR bch2_fmt(c, fmt), ##__VA_ARGS__) 287 #define bch_err_dev_ratelimited(ca, fmt, ...) \ 288 printk_ratelimited(KERN_ERR bch2_fmt_dev(ca, fmt), ##__VA_ARGS__) 289 #define bch_err_dev_offset_ratelimited(ca, _offset, fmt, ...) \ 290 printk_ratelimited(KERN_ERR bch2_fmt_dev_offset(ca, _offset, fmt), ##__VA_ARGS__) 291 #define bch_err_inum_ratelimited(c, _inum, fmt, ...) \ 292 printk_ratelimited(KERN_ERR bch2_fmt_inum(c, _inum, fmt), ##__VA_ARGS__) 293 #define bch_err_inum_offset_ratelimited(c, _inum, _offset, fmt, ...) \ 294 printk_ratelimited(KERN_ERR bch2_fmt_inum_offset(c, _inum, _offset, fmt), ##__VA_ARGS__) 295 296 #define bch_err_fn(_c, _ret) \ 297 do { \ 298 if (_ret && !bch2_err_matches(_ret, BCH_ERR_transaction_restart))\ 299 bch_err(_c, "%s(): error %s", __func__, bch2_err_str(_ret));\ 300 } while (0) 301 302 #define bch_err_msg(_c, _ret, _msg, ...) \ 303 do { \ 304 if (_ret && !bch2_err_matches(_ret, BCH_ERR_transaction_restart))\ 305 bch_err(_c, "%s(): error " _msg " %s", __func__, \ 306 ##__VA_ARGS__, bch2_err_str(_ret)); \ 307 } while (0) 308 309 #define bch_verbose(c, fmt, ...) \ 310 do { \ 311 if ((c)->opts.verbose) \ 312 bch_info(c, fmt, ##__VA_ARGS__); \ 313 } while (0) 314 315 #define pr_verbose_init(opts, fmt, ...) \ 316 do { \ 317 if (opt_get(opts, verbose)) \ 318 pr_info(fmt, ##__VA_ARGS__); \ 319 } while (0) 320 321 /* Parameters that are useful for debugging, but should always be compiled in: */ 322 #define BCH_DEBUG_PARAMS_ALWAYS() \ 323 BCH_DEBUG_PARAM(key_merging_disabled, \ 324 "Disables merging of extents") \ 325 BCH_DEBUG_PARAM(btree_gc_always_rewrite, \ 326 "Causes mark and sweep to compact and rewrite every " \ 327 "btree node it traverses") \ 328 BCH_DEBUG_PARAM(btree_gc_rewrite_disabled, \ 329 "Disables rewriting of btree nodes during mark and sweep")\ 330 BCH_DEBUG_PARAM(btree_shrinker_disabled, \ 331 "Disables the shrinker callback for the btree node cache")\ 332 BCH_DEBUG_PARAM(verify_btree_ondisk, \ 333 "Reread btree nodes at various points to verify the " \ 334 "mergesort in the read path against modifications " \ 335 "done in memory") \ 336 BCH_DEBUG_PARAM(verify_all_btree_replicas, \ 337 "When reading btree nodes, read all replicas and " \ 338 "compare them") \ 339 BCH_DEBUG_PARAM(backpointers_no_use_write_buffer, \ 340 "Don't use the write buffer for backpointers, enabling "\ 341 "extra runtime checks") 342 343 /* Parameters that should only be compiled in debug mode: */ 344 #define BCH_DEBUG_PARAMS_DEBUG() \ 345 BCH_DEBUG_PARAM(expensive_debug_checks, \ 346 "Enables various runtime debugging checks that " \ 347 "significantly affect performance") \ 348 BCH_DEBUG_PARAM(debug_check_iterators, \ 349 "Enables extra verification for btree iterators") \ 350 BCH_DEBUG_PARAM(debug_check_btree_accounting, \ 351 "Verify btree accounting for keys within a node") \ 352 BCH_DEBUG_PARAM(journal_seq_verify, \ 353 "Store the journal sequence number in the version " \ 354 "number of every btree key, and verify that btree " \ 355 "update ordering is preserved during recovery") \ 356 BCH_DEBUG_PARAM(inject_invalid_keys, \ 357 "Store the journal sequence number in the version " \ 358 "number of every btree key, and verify that btree " \ 359 "update ordering is preserved during recovery") \ 360 BCH_DEBUG_PARAM(test_alloc_startup, \ 361 "Force allocator startup to use the slowpath where it" \ 362 "can't find enough free buckets without invalidating" \ 363 "cached data") \ 364 BCH_DEBUG_PARAM(force_reconstruct_read, \ 365 "Force reads to use the reconstruct path, when reading" \ 366 "from erasure coded extents") \ 367 BCH_DEBUG_PARAM(test_restart_gc, \ 368 "Test restarting mark and sweep gc when bucket gens change") 369 370 #define BCH_DEBUG_PARAMS_ALL() BCH_DEBUG_PARAMS_ALWAYS() BCH_DEBUG_PARAMS_DEBUG() 371 372 #ifdef CONFIG_BCACHEFS_DEBUG 373 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALL() 374 #else 375 #define BCH_DEBUG_PARAMS() BCH_DEBUG_PARAMS_ALWAYS() 376 #endif 377 378 #define BCH_DEBUG_PARAM(name, description) extern bool bch2_##name; 379 BCH_DEBUG_PARAMS() 380 #undef BCH_DEBUG_PARAM 381 382 #ifndef CONFIG_BCACHEFS_DEBUG 383 #define BCH_DEBUG_PARAM(name, description) static const __maybe_unused bool bch2_##name; 384 BCH_DEBUG_PARAMS_DEBUG() 385 #undef BCH_DEBUG_PARAM 386 #endif 387 388 #define BCH_TIME_STATS() \ 389 x(btree_node_mem_alloc) \ 390 x(btree_node_split) \ 391 x(btree_node_compact) \ 392 x(btree_node_merge) \ 393 x(btree_node_sort) \ 394 x(btree_node_read) \ 395 x(btree_interior_update_foreground) \ 396 x(btree_interior_update_total) \ 397 x(btree_gc) \ 398 x(data_write) \ 399 x(data_read) \ 400 x(data_promote) \ 401 x(journal_flush_write) \ 402 x(journal_noflush_write) \ 403 x(journal_flush_seq) \ 404 x(blocked_journal) \ 405 x(blocked_allocate) \ 406 x(blocked_allocate_open_bucket) \ 407 x(nocow_lock_contended) 408 409 enum bch_time_stats { 410 #define x(name) BCH_TIME_##name, 411 BCH_TIME_STATS() 412 #undef x 413 BCH_TIME_STAT_NR 414 }; 415 416 #include "alloc_types.h" 417 #include "btree_types.h" 418 #include "btree_write_buffer_types.h" 419 #include "buckets_types.h" 420 #include "buckets_waiting_for_journal_types.h" 421 #include "clock_types.h" 422 #include "disk_groups_types.h" 423 #include "ec_types.h" 424 #include "journal_types.h" 425 #include "keylist_types.h" 426 #include "quota_types.h" 427 #include "rebalance_types.h" 428 #include "replicas_types.h" 429 #include "subvolume_types.h" 430 #include "super_types.h" 431 432 /* Number of nodes btree coalesce will try to coalesce at once */ 433 #define GC_MERGE_NODES 4U 434 435 /* Maximum number of nodes we might need to allocate atomically: */ 436 #define BTREE_RESERVE_MAX (BTREE_MAX_DEPTH + (BTREE_MAX_DEPTH - 1)) 437 438 /* Size of the freelist we allocate btree nodes from: */ 439 #define BTREE_NODE_RESERVE (BTREE_RESERVE_MAX * 4) 440 441 #define BTREE_NODE_OPEN_BUCKET_RESERVE (BTREE_RESERVE_MAX * BCH_REPLICAS_MAX) 442 443 struct btree; 444 445 enum gc_phase { 446 GC_PHASE_NOT_RUNNING, 447 GC_PHASE_START, 448 GC_PHASE_SB, 449 450 GC_PHASE_BTREE_stripes, 451 GC_PHASE_BTREE_extents, 452 GC_PHASE_BTREE_inodes, 453 GC_PHASE_BTREE_dirents, 454 GC_PHASE_BTREE_xattrs, 455 GC_PHASE_BTREE_alloc, 456 GC_PHASE_BTREE_quotas, 457 GC_PHASE_BTREE_reflink, 458 GC_PHASE_BTREE_subvolumes, 459 GC_PHASE_BTREE_snapshots, 460 GC_PHASE_BTREE_lru, 461 GC_PHASE_BTREE_freespace, 462 GC_PHASE_BTREE_need_discard, 463 GC_PHASE_BTREE_backpointers, 464 GC_PHASE_BTREE_bucket_gens, 465 GC_PHASE_BTREE_snapshot_trees, 466 GC_PHASE_BTREE_deleted_inodes, 467 GC_PHASE_BTREE_logged_ops, 468 GC_PHASE_BTREE_rebalance_work, 469 470 GC_PHASE_PENDING_DELETE, 471 }; 472 473 struct gc_pos { 474 enum gc_phase phase; 475 struct bpos pos; 476 unsigned level; 477 }; 478 479 struct reflink_gc { 480 u64 offset; 481 u32 size; 482 u32 refcount; 483 }; 484 485 typedef GENRADIX(struct reflink_gc) reflink_gc_table; 486 487 struct io_count { 488 u64 sectors[2][BCH_DATA_NR]; 489 }; 490 491 struct bch_dev { 492 struct kobject kobj; 493 struct percpu_ref ref; 494 struct completion ref_completion; 495 struct percpu_ref io_ref; 496 struct completion io_ref_completion; 497 498 struct bch_fs *fs; 499 500 u8 dev_idx; 501 /* 502 * Cached version of this device's member info from superblock 503 * Committed by bch2_write_super() -> bch_fs_mi_update() 504 */ 505 struct bch_member_cpu mi; 506 atomic64_t errors[BCH_MEMBER_ERROR_NR]; 507 508 __uuid_t uuid; 509 char name[BDEVNAME_SIZE]; 510 511 struct bch_sb_handle disk_sb; 512 struct bch_sb *sb_read_scratch; 513 int sb_write_error; 514 dev_t dev; 515 atomic_t flush_seq; 516 517 struct bch_devs_mask self; 518 519 /* biosets used in cloned bios for writing multiple replicas */ 520 struct bio_set replica_set; 521 522 /* 523 * Buckets: 524 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and 525 * gc_lock, for device resize - holding any is sufficient for access: 526 * Or rcu_read_lock(), but only for ptr_stale(): 527 */ 528 struct bucket_array __rcu *buckets_gc; 529 struct bucket_gens __rcu *bucket_gens; 530 u8 *oldest_gen; 531 unsigned long *buckets_nouse; 532 struct rw_semaphore bucket_lock; 533 534 struct bch_dev_usage *usage_base; 535 struct bch_dev_usage __percpu *usage[JOURNAL_BUF_NR]; 536 struct bch_dev_usage __percpu *usage_gc; 537 538 /* Allocator: */ 539 u64 new_fs_bucket_idx; 540 u64 alloc_cursor; 541 542 unsigned nr_open_buckets; 543 unsigned nr_btree_reserve; 544 545 size_t inc_gen_needs_gc; 546 size_t inc_gen_really_needs_gc; 547 size_t buckets_waiting_on_journal; 548 549 atomic64_t rebalance_work; 550 551 struct journal_device journal; 552 u64 prev_journal_sector; 553 554 struct work_struct io_error_work; 555 556 /* The rest of this all shows up in sysfs */ 557 atomic64_t cur_latency[2]; 558 struct bch2_time_stats io_latency[2]; 559 560 #define CONGESTED_MAX 1024 561 atomic_t congested; 562 u64 congested_last; 563 564 struct io_count __percpu *io_done; 565 }; 566 567 enum { 568 /* startup: */ 569 BCH_FS_STARTED, 570 BCH_FS_MAY_GO_RW, 571 BCH_FS_RW, 572 BCH_FS_WAS_RW, 573 574 /* shutdown: */ 575 BCH_FS_STOPPING, 576 BCH_FS_EMERGENCY_RO, 577 BCH_FS_GOING_RO, 578 BCH_FS_WRITE_DISABLE_COMPLETE, 579 BCH_FS_CLEAN_SHUTDOWN, 580 581 /* fsck passes: */ 582 BCH_FS_FSCK_DONE, 583 BCH_FS_INITIAL_GC_UNFIXED, /* kill when we enumerate fsck errors */ 584 BCH_FS_NEED_ANOTHER_GC, 585 586 BCH_FS_NEED_DELETE_DEAD_SNAPSHOTS, 587 588 /* errors: */ 589 BCH_FS_ERROR, 590 BCH_FS_TOPOLOGY_ERROR, 591 BCH_FS_ERRORS_FIXED, 592 BCH_FS_ERRORS_NOT_FIXED, 593 }; 594 595 struct btree_debug { 596 unsigned id; 597 }; 598 599 #define BCH_TRANSACTIONS_NR 128 600 601 struct btree_transaction_stats { 602 struct bch2_time_stats lock_hold_times; 603 struct mutex lock; 604 unsigned nr_max_paths; 605 unsigned wb_updates_size; 606 unsigned max_mem; 607 char *max_paths_text; 608 }; 609 610 struct bch_fs_pcpu { 611 u64 sectors_available; 612 }; 613 614 struct journal_seq_blacklist_table { 615 size_t nr; 616 struct journal_seq_blacklist_table_entry { 617 u64 start; 618 u64 end; 619 bool dirty; 620 } entries[]; 621 }; 622 623 struct journal_keys { 624 struct journal_key { 625 u64 journal_seq; 626 u32 journal_offset; 627 enum btree_id btree_id:8; 628 unsigned level:8; 629 bool allocated; 630 bool overwritten; 631 struct bkey_i *k; 632 } *d; 633 /* 634 * Gap buffer: instead of all the empty space in the array being at the 635 * end of the buffer - from @nr to @size - the empty space is at @gap. 636 * This means that sequential insertions are O(n) instead of O(n^2). 637 */ 638 size_t gap; 639 size_t nr; 640 size_t size; 641 atomic_t ref; 642 bool initial_ref_held; 643 }; 644 645 struct btree_trans_buf { 646 struct btree_trans *trans; 647 }; 648 649 #define REPLICAS_DELTA_LIST_MAX (1U << 16) 650 651 #define BCACHEFS_ROOT_SUBVOL_INUM \ 652 ((subvol_inum) { BCACHEFS_ROOT_SUBVOL, BCACHEFS_ROOT_INO }) 653 654 #define BCH_WRITE_REFS() \ 655 x(trans) \ 656 x(write) \ 657 x(promote) \ 658 x(node_rewrite) \ 659 x(stripe_create) \ 660 x(stripe_delete) \ 661 x(reflink) \ 662 x(fallocate) \ 663 x(discard) \ 664 x(invalidate) \ 665 x(delete_dead_snapshots) \ 666 x(snapshot_delete_pagecache) \ 667 x(sysfs) 668 669 enum bch_write_ref { 670 #define x(n) BCH_WRITE_REF_##n, 671 BCH_WRITE_REFS() 672 #undef x 673 BCH_WRITE_REF_NR, 674 }; 675 676 struct bch_fs { 677 struct closure cl; 678 679 struct list_head list; 680 struct kobject kobj; 681 struct kobject counters_kobj; 682 struct kobject internal; 683 struct kobject opts_dir; 684 struct kobject time_stats; 685 unsigned long flags; 686 687 int minor; 688 struct device *chardev; 689 struct super_block *vfs_sb; 690 dev_t dev; 691 char name[40]; 692 693 /* ro/rw, add/remove/resize devices: */ 694 struct rw_semaphore state_lock; 695 696 /* Counts outstanding writes, for clean transition to read-only */ 697 #ifdef BCH_WRITE_REF_DEBUG 698 atomic_long_t writes[BCH_WRITE_REF_NR]; 699 #else 700 struct percpu_ref writes; 701 #endif 702 struct work_struct read_only_work; 703 704 struct bch_dev __rcu *devs[BCH_SB_MEMBERS_MAX]; 705 706 struct bch_replicas_cpu replicas; 707 struct bch_replicas_cpu replicas_gc; 708 struct mutex replicas_gc_lock; 709 mempool_t replicas_delta_pool; 710 711 struct journal_entry_res btree_root_journal_res; 712 struct journal_entry_res replicas_journal_res; 713 struct journal_entry_res clock_journal_res; 714 struct journal_entry_res dev_usage_journal_res; 715 716 struct bch_disk_groups_cpu __rcu *disk_groups; 717 718 struct bch_opts opts; 719 720 /* Updated by bch2_sb_update():*/ 721 struct { 722 __uuid_t uuid; 723 __uuid_t user_uuid; 724 725 u16 version; 726 u16 version_min; 727 u16 version_upgrade_complete; 728 729 u8 nr_devices; 730 u8 clean; 731 732 u8 encryption_type; 733 734 u64 time_base_lo; 735 u32 time_base_hi; 736 unsigned time_units_per_sec; 737 unsigned nsec_per_time_unit; 738 u64 features; 739 u64 compat; 740 } sb; 741 742 743 struct bch_sb_handle disk_sb; 744 745 unsigned short block_bits; /* ilog2(block_size) */ 746 747 u16 btree_foreground_merge_threshold; 748 749 struct closure sb_write; 750 struct mutex sb_lock; 751 752 /* snapshot.c: */ 753 struct snapshot_table __rcu *snapshots; 754 size_t snapshot_table_size; 755 struct mutex snapshot_table_lock; 756 struct rw_semaphore snapshot_create_lock; 757 758 struct work_struct snapshot_delete_work; 759 struct work_struct snapshot_wait_for_pagecache_and_delete_work; 760 snapshot_id_list snapshots_unlinked; 761 struct mutex snapshots_unlinked_lock; 762 763 /* BTREE CACHE */ 764 struct bio_set btree_bio; 765 struct workqueue_struct *io_complete_wq; 766 767 struct btree_root btree_roots_known[BTREE_ID_NR]; 768 DARRAY(struct btree_root) btree_roots_extra; 769 struct mutex btree_root_lock; 770 771 struct btree_cache btree_cache; 772 773 /* 774 * Cache of allocated btree nodes - if we allocate a btree node and 775 * don't use it, if we free it that space can't be reused until going 776 * _all_ the way through the allocator (which exposes us to a livelock 777 * when allocating btree reserves fail halfway through) - instead, we 778 * can stick them here: 779 */ 780 struct btree_alloc btree_reserve_cache[BTREE_NODE_RESERVE * 2]; 781 unsigned btree_reserve_cache_nr; 782 struct mutex btree_reserve_cache_lock; 783 784 mempool_t btree_interior_update_pool; 785 struct list_head btree_interior_update_list; 786 struct list_head btree_interior_updates_unwritten; 787 struct mutex btree_interior_update_lock; 788 struct closure_waitlist btree_interior_update_wait; 789 790 struct workqueue_struct *btree_interior_update_worker; 791 struct work_struct btree_interior_update_work; 792 793 struct list_head pending_node_rewrites; 794 struct mutex pending_node_rewrites_lock; 795 796 /* btree_io.c: */ 797 spinlock_t btree_write_error_lock; 798 struct btree_write_stats { 799 atomic64_t nr; 800 atomic64_t bytes; 801 } btree_write_stats[BTREE_WRITE_TYPE_NR]; 802 803 /* btree_iter.c: */ 804 struct seqmutex btree_trans_lock; 805 struct list_head btree_trans_list; 806 mempool_t btree_trans_pool; 807 mempool_t btree_trans_mem_pool; 808 struct btree_trans_buf __percpu *btree_trans_bufs; 809 810 struct srcu_struct btree_trans_barrier; 811 bool btree_trans_barrier_initialized; 812 813 struct btree_key_cache btree_key_cache; 814 unsigned btree_key_cache_btrees; 815 816 struct btree_write_buffer btree_write_buffer; 817 818 struct workqueue_struct *btree_update_wq; 819 struct workqueue_struct *btree_io_complete_wq; 820 /* copygc needs its own workqueue for index updates.. */ 821 struct workqueue_struct *copygc_wq; 822 /* 823 * Use a dedicated wq for write ref holder tasks. Required to avoid 824 * dependency problems with other wq tasks that can block on ref 825 * draining, such as read-only transition. 826 */ 827 struct workqueue_struct *write_ref_wq; 828 829 /* ALLOCATION */ 830 struct bch_devs_mask rw_devs[BCH_DATA_NR]; 831 832 u64 capacity; /* sectors */ 833 834 /* 835 * When capacity _decreases_ (due to a disk being removed), we 836 * increment capacity_gen - this invalidates outstanding reservations 837 * and forces them to be revalidated 838 */ 839 u32 capacity_gen; 840 unsigned bucket_size_max; 841 842 atomic64_t sectors_available; 843 struct mutex sectors_available_lock; 844 845 struct bch_fs_pcpu __percpu *pcpu; 846 847 struct percpu_rw_semaphore mark_lock; 848 849 seqcount_t usage_lock; 850 struct bch_fs_usage *usage_base; 851 struct bch_fs_usage __percpu *usage[JOURNAL_BUF_NR]; 852 struct bch_fs_usage __percpu *usage_gc; 853 u64 __percpu *online_reserved; 854 855 /* single element mempool: */ 856 struct mutex usage_scratch_lock; 857 struct bch_fs_usage_online *usage_scratch; 858 859 struct io_clock io_clock[2]; 860 861 /* JOURNAL SEQ BLACKLIST */ 862 struct journal_seq_blacklist_table * 863 journal_seq_blacklist_table; 864 struct work_struct journal_seq_blacklist_gc_work; 865 866 /* ALLOCATOR */ 867 spinlock_t freelist_lock; 868 struct closure_waitlist freelist_wait; 869 u64 blocked_allocate; 870 u64 blocked_allocate_open_bucket; 871 872 open_bucket_idx_t open_buckets_freelist; 873 open_bucket_idx_t open_buckets_nr_free; 874 struct closure_waitlist open_buckets_wait; 875 struct open_bucket open_buckets[OPEN_BUCKETS_COUNT]; 876 open_bucket_idx_t open_buckets_hash[OPEN_BUCKETS_COUNT]; 877 878 open_bucket_idx_t open_buckets_partial[OPEN_BUCKETS_COUNT]; 879 open_bucket_idx_t open_buckets_partial_nr; 880 881 struct write_point btree_write_point; 882 struct write_point rebalance_write_point; 883 884 struct write_point write_points[WRITE_POINT_MAX]; 885 struct hlist_head write_points_hash[WRITE_POINT_HASH_NR]; 886 struct mutex write_points_hash_lock; 887 unsigned write_points_nr; 888 889 struct buckets_waiting_for_journal buckets_waiting_for_journal; 890 struct work_struct discard_work; 891 struct work_struct invalidate_work; 892 893 /* GARBAGE COLLECTION */ 894 struct task_struct *gc_thread; 895 atomic_t kick_gc; 896 unsigned long gc_count; 897 898 enum btree_id gc_gens_btree; 899 struct bpos gc_gens_pos; 900 901 /* 902 * Tracks GC's progress - everything in the range [ZERO_KEY..gc_cur_pos] 903 * has been marked by GC. 904 * 905 * gc_cur_phase is a superset of btree_ids (BTREE_ID_extents etc.) 906 * 907 * Protected by gc_pos_lock. Only written to by GC thread, so GC thread 908 * can read without a lock. 909 */ 910 seqcount_t gc_pos_lock; 911 struct gc_pos gc_pos; 912 913 /* 914 * The allocation code needs gc_mark in struct bucket to be correct, but 915 * it's not while a gc is in progress. 916 */ 917 struct rw_semaphore gc_lock; 918 struct mutex gc_gens_lock; 919 920 /* IO PATH */ 921 struct semaphore io_in_flight; 922 struct bio_set bio_read; 923 struct bio_set bio_read_split; 924 struct bio_set bio_write; 925 struct mutex bio_bounce_pages_lock; 926 mempool_t bio_bounce_pages; 927 struct bucket_nocow_lock_table 928 nocow_locks; 929 struct rhashtable promote_table; 930 931 mempool_t compression_bounce[2]; 932 mempool_t compress_workspace[BCH_COMPRESSION_TYPE_NR]; 933 mempool_t decompress_workspace; 934 size_t zstd_workspace_size; 935 936 struct crypto_shash *sha256; 937 struct crypto_sync_skcipher *chacha20; 938 struct crypto_shash *poly1305; 939 940 atomic64_t key_version; 941 942 mempool_t large_bkey_pool; 943 944 /* MOVE.C */ 945 struct list_head moving_context_list; 946 struct mutex moving_context_lock; 947 948 /* REBALANCE */ 949 struct bch_fs_rebalance rebalance; 950 951 /* COPYGC */ 952 struct task_struct *copygc_thread; 953 struct write_point copygc_write_point; 954 s64 copygc_wait_at; 955 s64 copygc_wait; 956 bool copygc_running; 957 wait_queue_head_t copygc_running_wq; 958 959 /* STRIPES: */ 960 GENRADIX(struct stripe) stripes; 961 GENRADIX(struct gc_stripe) gc_stripes; 962 963 struct hlist_head ec_stripes_new[32]; 964 spinlock_t ec_stripes_new_lock; 965 966 ec_stripes_heap ec_stripes_heap; 967 struct mutex ec_stripes_heap_lock; 968 969 /* ERASURE CODING */ 970 struct list_head ec_stripe_head_list; 971 struct mutex ec_stripe_head_lock; 972 973 struct list_head ec_stripe_new_list; 974 struct mutex ec_stripe_new_lock; 975 wait_queue_head_t ec_stripe_new_wait; 976 977 struct work_struct ec_stripe_create_work; 978 u64 ec_stripe_hint; 979 980 struct work_struct ec_stripe_delete_work; 981 982 struct bio_set ec_bioset; 983 984 /* REFLINK */ 985 reflink_gc_table reflink_gc_table; 986 size_t reflink_gc_nr; 987 988 /* fs.c */ 989 struct list_head vfs_inodes_list; 990 struct mutex vfs_inodes_lock; 991 992 /* VFS IO PATH - fs-io.c */ 993 struct bio_set writepage_bioset; 994 struct bio_set dio_write_bioset; 995 struct bio_set dio_read_bioset; 996 struct bio_set nocow_flush_bioset; 997 998 /* QUOTAS */ 999 struct bch_memquota_type quotas[QTYP_NR]; 1000 1001 /* RECOVERY */ 1002 u64 journal_replay_seq_start; 1003 u64 journal_replay_seq_end; 1004 enum bch_recovery_pass curr_recovery_pass; 1005 /* bitmap of explicitly enabled recovery passes: */ 1006 u64 recovery_passes_explicit; 1007 u64 recovery_passes_complete; 1008 1009 /* DEBUG JUNK */ 1010 struct dentry *fs_debug_dir; 1011 struct dentry *btree_debug_dir; 1012 struct btree_debug btree_debug[BTREE_ID_NR]; 1013 struct btree *verify_data; 1014 struct btree_node *verify_ondisk; 1015 struct mutex verify_lock; 1016 1017 u64 *unused_inode_hints; 1018 unsigned inode_shard_bits; 1019 1020 /* 1021 * A btree node on disk could have too many bsets for an iterator to fit 1022 * on the stack - have to dynamically allocate them 1023 */ 1024 mempool_t fill_iter; 1025 1026 mempool_t btree_bounce_pool; 1027 1028 struct journal journal; 1029 GENRADIX(struct journal_replay *) journal_entries; 1030 u64 journal_entries_base_seq; 1031 struct journal_keys journal_keys; 1032 struct list_head journal_iters; 1033 1034 u64 last_bucket_seq_cleanup; 1035 1036 u64 counters_on_mount[BCH_COUNTER_NR]; 1037 u64 __percpu *counters; 1038 1039 unsigned btree_gc_periodic:1; 1040 unsigned copy_gc_enabled:1; 1041 bool promote_whole_extents; 1042 1043 struct bch2_time_stats times[BCH_TIME_STAT_NR]; 1044 1045 struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR]; 1046 1047 /* ERRORS */ 1048 struct list_head fsck_error_msgs; 1049 struct mutex fsck_error_msgs_lock; 1050 bool fsck_alloc_msgs_err; 1051 1052 bch_sb_errors_cpu fsck_error_counts; 1053 struct mutex fsck_error_counts_lock; 1054 }; 1055 1056 extern struct wait_queue_head bch2_read_only_wait; 1057 1058 static inline void bch2_write_ref_get(struct bch_fs *c, enum bch_write_ref ref) 1059 { 1060 #ifdef BCH_WRITE_REF_DEBUG 1061 atomic_long_inc(&c->writes[ref]); 1062 #else 1063 percpu_ref_get(&c->writes); 1064 #endif 1065 } 1066 1067 static inline bool bch2_write_ref_tryget(struct bch_fs *c, enum bch_write_ref ref) 1068 { 1069 #ifdef BCH_WRITE_REF_DEBUG 1070 return !test_bit(BCH_FS_GOING_RO, &c->flags) && 1071 atomic_long_inc_not_zero(&c->writes[ref]); 1072 #else 1073 return percpu_ref_tryget_live(&c->writes); 1074 #endif 1075 } 1076 1077 static inline void bch2_write_ref_put(struct bch_fs *c, enum bch_write_ref ref) 1078 { 1079 #ifdef BCH_WRITE_REF_DEBUG 1080 long v = atomic_long_dec_return(&c->writes[ref]); 1081 1082 BUG_ON(v < 0); 1083 if (v) 1084 return; 1085 for (unsigned i = 0; i < BCH_WRITE_REF_NR; i++) 1086 if (atomic_long_read(&c->writes[i])) 1087 return; 1088 1089 set_bit(BCH_FS_WRITE_DISABLE_COMPLETE, &c->flags); 1090 wake_up(&bch2_read_only_wait); 1091 #else 1092 percpu_ref_put(&c->writes); 1093 #endif 1094 } 1095 1096 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages) 1097 { 1098 #ifndef NO_BCACHEFS_FS 1099 if (c->vfs_sb) 1100 c->vfs_sb->s_bdi->ra_pages = ra_pages; 1101 #endif 1102 } 1103 1104 static inline unsigned bucket_bytes(const struct bch_dev *ca) 1105 { 1106 return ca->mi.bucket_size << 9; 1107 } 1108 1109 static inline unsigned block_bytes(const struct bch_fs *c) 1110 { 1111 return c->opts.block_size; 1112 } 1113 1114 static inline unsigned block_sectors(const struct bch_fs *c) 1115 { 1116 return c->opts.block_size >> 9; 1117 } 1118 1119 static inline size_t btree_sectors(const struct bch_fs *c) 1120 { 1121 return c->opts.btree_node_size >> 9; 1122 } 1123 1124 static inline bool btree_id_cached(const struct bch_fs *c, enum btree_id btree) 1125 { 1126 return c->btree_key_cache_btrees & (1U << btree); 1127 } 1128 1129 static inline struct timespec64 bch2_time_to_timespec(const struct bch_fs *c, s64 time) 1130 { 1131 struct timespec64 t; 1132 s32 rem; 1133 1134 time += c->sb.time_base_lo; 1135 1136 t.tv_sec = div_s64_rem(time, c->sb.time_units_per_sec, &rem); 1137 t.tv_nsec = rem * c->sb.nsec_per_time_unit; 1138 return t; 1139 } 1140 1141 static inline s64 timespec_to_bch2_time(const struct bch_fs *c, struct timespec64 ts) 1142 { 1143 return (ts.tv_sec * c->sb.time_units_per_sec + 1144 (int) ts.tv_nsec / c->sb.nsec_per_time_unit) - c->sb.time_base_lo; 1145 } 1146 1147 static inline s64 bch2_current_time(const struct bch_fs *c) 1148 { 1149 struct timespec64 now; 1150 1151 ktime_get_coarse_real_ts64(&now); 1152 return timespec_to_bch2_time(c, now); 1153 } 1154 1155 static inline bool bch2_dev_exists2(const struct bch_fs *c, unsigned dev) 1156 { 1157 return dev < c->sb.nr_devices && c->devs[dev]; 1158 } 1159 1160 #define BKEY_PADDED_ONSTACK(key, pad) \ 1161 struct { struct bkey_i key; __u64 key ## _pad[pad]; } 1162 1163 #endif /* _BCACHEFS_H */ 1164