git.sesse.net Git - bcachefs-tools-debian/blob - libbcachefs/btree_types.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_BTREE_TYPES_H
   3 #define _BCACHEFS_BTREE_TYPES_H
   4
   5 #include <linux/list.h>
   6 #include <linux/rhashtable.h>
   7 #include <linux/six.h>
   8
   9 #include "bkey_methods.h"
  10 #include "buckets_types.h"
  11 #include "journal_types.h"
  12
  13 struct open_bucket;
  14 struct btree_update;
  15 struct btree_trans;
  16
  17 #define MAX_BSETS               3U
  18
  19 struct btree_nr_keys {
  20
  21         /*
  22          * Amount of live metadata (i.e. size of node after a compaction) in
  23          * units of u64s
  24          */
  25         u16                     live_u64s;
  26         u16                     bset_u64s[MAX_BSETS];
  27
  28         /* live keys only: */
  29         u16                     packed_keys;
  30         u16                     unpacked_keys;
  31 };
  32
  33 struct bset_tree {
  34         /*
  35          * We construct a binary tree in an array as if the array
  36          * started at 1, so that things line up on the same cachelines
  37          * better: see comments in bset.c at cacheline_to_bkey() for
  38          * details
  39          */
  40
  41         /* size of the binary tree and prev array */
  42         u16                     size;
  43
  44         /* function of size - precalculated for to_inorder() */
  45         u16                     extra;
  46
  47         u16                     data_offset;
  48         u16                     aux_data_offset;
  49         u16                     end_offset;
  50
  51         struct bpos             max_key;
  52 };
  53
  54 struct btree_write {
  55         struct journal_entry_pin        journal;
  56         struct closure_waitlist         wait;
  57 };
  58
  59 struct btree_alloc {
  60         struct open_buckets     ob;
  61         BKEY_PADDED(k);
  62 };
  63
  64 struct btree {
  65         /* Hottest entries first */
  66         struct rhash_head       hash;
  67         u64                     hash_val;
  68
  69         struct six_lock         lock;
  70
  71         unsigned long           flags;
  72         u16                     written;
  73         u8                      level;
  74         u8                      btree_id;
  75         u8                      nsets;
  76         u8                      nr_key_bits;
  77
  78         struct bkey_format      format;
  79
  80         struct btree_node       *data;
  81         void                    *aux_data;
  82
  83         /*
  84          * Sets of sorted keys - the real btree node - plus a binary search tree
  85          *
  86          * set[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
  87          * to the memory we have allocated for this btree node. Additionally,
  88          * set[0]->data points to the entire btree node as it exists on disk.
  89          */
  90         struct bset_tree        set[MAX_BSETS];
  91
  92         struct btree_nr_keys    nr;
  93         u16                     sib_u64s[2];
  94         u16                     whiteout_u64s;
  95         u8                      page_order;
  96         u8                      unpack_fn_len;
  97
  98         /*
  99          * XXX: add a delete sequence number, so when bch2_btree_node_relock()
 100          * fails because the lock sequence number has changed - i.e. the
 101          * contents were modified - we can still relock the node if it's still
 102          * the one we want, without redoing the traversal
 103          */
 104
 105         /*
 106          * For asynchronous splits/interior node updates:
 107          * When we do a split, we allocate new child nodes and update the parent
 108          * node to point to them: we update the parent in memory immediately,
 109          * but then we must wait until the children have been written out before
 110          * the update to the parent can be written - this is a list of the
 111          * btree_updates that are blocking this node from being
 112          * written:
 113          */
 114         struct list_head        write_blocked;
 115
 116         /*
 117          * Also for asynchronous splits/interior node updates:
 118          * If a btree node isn't reachable yet, we don't want to kick off
 119          * another write - because that write also won't yet be reachable and
 120          * marking it as completed before it's reachable would be incorrect:
 121          */
 122         unsigned long           will_make_reachable;
 123
 124         struct open_buckets     ob;
 125
 126         /* lru list */
 127         struct list_head        list;
 128
 129         struct btree_write      writes[2];
 130
 131 #ifdef CONFIG_BCACHEFS_DEBUG
 132         bool                    *expensive_debug_checks;
 133 #endif
 134
 135         /* Key/pointer for this btree node */
 136         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 137 };
 138
 139 struct btree_cache {
 140         struct rhashtable       table;
 141         bool                    table_init_done;
 142         /*
 143          * We never free a struct btree, except on shutdown - we just put it on
 144          * the btree_cache_freed list and reuse it later. This simplifies the
 145          * code, and it doesn't cost us much memory as the memory usage is
 146          * dominated by buffers that hold the actual btree node data and those
 147          * can be freed - and the number of struct btrees allocated is
 148          * effectively bounded.
 149          *
 150          * btree_cache_freeable effectively is a small cache - we use it because
 151          * high order page allocations can be rather expensive, and it's quite
 152          * common to delete and allocate btree nodes in quick succession. It
 153          * should never grow past ~2-3 nodes in practice.
 154          */
 155         struct mutex            lock;
 156         struct list_head        live;
 157         struct list_head        freeable;
 158         struct list_head        freed;
 159
 160         /* Number of elements in live + freeable lists */
 161         unsigned                used;
 162         unsigned                reserve;
 163         struct shrinker         shrink;
 164
 165         /*
 166          * If we need to allocate memory for a new btree node and that
 167          * allocation fails, we can cannibalize another node in the btree cache
 168          * to satisfy the allocation - lock to guarantee only one thread does
 169          * this at a time:
 170          */
 171         struct task_struct      *alloc_lock;
 172         struct closure_waitlist alloc_wait;
 173 };
 174
 175 struct btree_node_iter {
 176         struct btree_node_iter_set {
 177                 u16     k, end;
 178         } data[MAX_BSETS];
 179 };
 180
 181 enum btree_iter_type {
 182         BTREE_ITER_KEYS,
 183         BTREE_ITER_NODES,
 184 };
 185
 186 #define BTREE_ITER_TYPE                 ((1 << 2) - 1)
 187
 188 /*
 189  * Iterate over all possible positions, synthesizing deleted keys for holes:
 190  */
 191 #define BTREE_ITER_SLOTS                (1 << 2)
 192 /*
 193  * Indicates that intent locks should be taken on leaf nodes, because we expect
 194  * to be doing updates:
 195  */
 196 #define BTREE_ITER_INTENT               (1 << 3)
 197 /*
 198  * Causes the btree iterator code to prefetch additional btree nodes from disk:
 199  */
 200 #define BTREE_ITER_PREFETCH             (1 << 4)
 201 /*
 202  * Indicates that this iterator should not be reused until transaction commit,
 203  * either because a pending update references it or because the update depends
 204  * on that particular key being locked (e.g. by the str_hash code, for hash
 205  * table consistency)
 206  */
 207 #define BTREE_ITER_KEEP_UNTIL_COMMIT    (1 << 5)
 208 /*
 209  * Used in bch2_btree_iter_traverse(), to indicate whether we're searching for
 210  * @pos or the first key strictly greater than @pos
 211  */
 212 #define BTREE_ITER_IS_EXTENTS           (1 << 6)
 213 #define BTREE_ITER_ERROR                (1 << 7)
 214 #define BTREE_ITER_SET_POS_AFTER_COMMIT (1 << 8)
 215
 216 enum btree_iter_uptodate {
 217         BTREE_ITER_UPTODATE             = 0,
 218         BTREE_ITER_NEED_PEEK            = 1,
 219         BTREE_ITER_NEED_RELOCK          = 2,
 220         BTREE_ITER_NEED_TRAVERSE        = 3,
 221 };
 222
 223 /*
 224  * @pos                 - iterator's current position
 225  * @level               - current btree depth
 226  * @locks_want          - btree level below which we start taking intent locks
 227  * @nodes_locked        - bitmask indicating which nodes in @nodes are locked
 228  * @nodes_intent_locked - bitmask indicating which locks are intent locks
 229  */
 230 struct btree_iter {
 231         struct btree_trans      *trans;
 232         struct bpos             pos;
 233         struct bpos             pos_after_commit;
 234
 235         u16                     flags;
 236         u8                      idx;
 237
 238         enum btree_id           btree_id:4;
 239         enum btree_iter_uptodate uptodate:4;
 240         unsigned                level:4,
 241                                 min_depth:4,
 242                                 locks_want:4,
 243                                 nodes_locked:4,
 244                                 nodes_intent_locked:4;
 245
 246         struct btree_iter_level {
 247                 struct btree    *b;
 248                 struct btree_node_iter iter;
 249                 u32             lock_seq;
 250         }                       l[BTREE_MAX_DEPTH];
 251
 252         /*
 253          * Current unpacked key - so that bch2_btree_iter_next()/
 254          * bch2_btree_iter_next_slot() can correctly advance pos.
 255          */
 256         struct bkey             k;
 257 };
 258
 259 static inline enum btree_iter_type btree_iter_type(struct btree_iter *iter)
 260 {
 261         return iter->flags & BTREE_ITER_TYPE;
 262 }
 263
 264 struct btree_insert_entry {
 265         unsigned                trigger_flags;
 266         unsigned                trans_triggers_run:1;
 267         struct bkey_i           *k;
 268         struct btree_iter       *iter;
 269 };
 270
 271 #define BTREE_ITER_MAX          64
 272
 273 struct btree_trans {
 274         struct bch_fs           *c;
 275         unsigned long           ip;
 276
 277         u64                     iters_linked;
 278         u64                     iters_live;
 279         u64                     iters_touched;
 280
 281         u8                      nr_iters;
 282         u8                      nr_updates;
 283         u8                      nr_updates2;
 284         u8                      size;
 285         unsigned                used_mempool:1;
 286         unsigned                error:1;
 287         unsigned                nounlock:1;
 288         unsigned                need_reset:1;
 289
 290         unsigned                mem_top;
 291         unsigned                mem_bytes;
 292         void                    *mem;
 293
 294         struct btree_iter       *iters;
 295         struct btree_insert_entry *updates;
 296         struct btree_insert_entry *updates2;
 297
 298         /* update path: */
 299         struct journal_res      journal_res;
 300         struct journal_preres   journal_preres;
 301         u64                     *journal_seq;
 302         struct disk_reservation *disk_res;
 303         unsigned                flags;
 304         unsigned                journal_u64s;
 305         unsigned                journal_preres_u64s;
 306         struct replicas_delta_list *fs_usage_deltas;
 307
 308         struct btree_iter       iters_onstack[2];
 309         struct btree_insert_entry updates_onstack[2];
 310         struct btree_insert_entry updates2_onstack[2];
 311 };
 312
 313 #define BTREE_FLAG(flag)                                                \
 314 static inline bool btree_node_ ## flag(struct btree *b)                 \
 315 {       return test_bit(BTREE_NODE_ ## flag, &b->flags); }              \
 316                                                                         \
 317 static inline void set_btree_node_ ## flag(struct btree *b)             \
 318 {       set_bit(BTREE_NODE_ ## flag, &b->flags); }                      \
 319                                                                         \
 320 static inline void clear_btree_node_ ## flag(struct btree *b)           \
 321 {       clear_bit(BTREE_NODE_ ## flag, &b->flags); }
 322
 323 enum btree_flags {
 324         BTREE_NODE_read_in_flight,
 325         BTREE_NODE_read_error,
 326         BTREE_NODE_dirty,
 327         BTREE_NODE_need_write,
 328         BTREE_NODE_noevict,
 329         BTREE_NODE_write_idx,
 330         BTREE_NODE_accessed,
 331         BTREE_NODE_write_in_flight,
 332         BTREE_NODE_just_written,
 333         BTREE_NODE_dying,
 334         BTREE_NODE_fake,
 335         BTREE_NODE_old_extent_overwrite,
 336 };
 337
 338 BTREE_FLAG(read_in_flight);
 339 BTREE_FLAG(read_error);
 340 BTREE_FLAG(dirty);
 341 BTREE_FLAG(need_write);
 342 BTREE_FLAG(noevict);
 343 BTREE_FLAG(write_idx);
 344 BTREE_FLAG(accessed);
 345 BTREE_FLAG(write_in_flight);
 346 BTREE_FLAG(just_written);
 347 BTREE_FLAG(dying);
 348 BTREE_FLAG(fake);
 349 BTREE_FLAG(old_extent_overwrite);
 350
 351 static inline struct btree_write *btree_current_write(struct btree *b)
 352 {
 353         return b->writes + btree_node_write_idx(b);
 354 }
 355
 356 static inline struct btree_write *btree_prev_write(struct btree *b)
 357 {
 358         return b->writes + (btree_node_write_idx(b) ^ 1);
 359 }
 360
 361 static inline struct bset_tree *bset_tree_last(struct btree *b)
 362 {
 363         EBUG_ON(!b->nsets);
 364         return b->set + b->nsets - 1;
 365 }
 366
 367 static inline void *
 368 __btree_node_offset_to_ptr(const struct btree *b, u16 offset)
 369 {
 370         return (void *) ((u64 *) b->data + 1 + offset);
 371 }
 372
 373 static inline u16
 374 __btree_node_ptr_to_offset(const struct btree *b, const void *p)
 375 {
 376         u16 ret = (u64 *) p - 1 - (u64 *) b->data;
 377
 378         EBUG_ON(__btree_node_offset_to_ptr(b, ret) != p);
 379         return ret;
 380 }
 381
 382 static inline struct bset *bset(const struct btree *b,
 383                                 const struct bset_tree *t)
 384 {
 385         return __btree_node_offset_to_ptr(b, t->data_offset);
 386 }
 387
 388 static inline void set_btree_bset_end(struct btree *b, struct bset_tree *t)
 389 {
 390         t->end_offset =
 391                 __btree_node_ptr_to_offset(b, vstruct_last(bset(b, t)));
 392 }
 393
 394 static inline void set_btree_bset(struct btree *b, struct bset_tree *t,
 395                                   const struct bset *i)
 396 {
 397         t->data_offset = __btree_node_ptr_to_offset(b, i);
 398         set_btree_bset_end(b, t);
 399 }
 400
 401 static inline struct bset *btree_bset_first(struct btree *b)
 402 {
 403         return bset(b, b->set);
 404 }
 405
 406 static inline struct bset *btree_bset_last(struct btree *b)
 407 {
 408         return bset(b, bset_tree_last(b));
 409 }
 410
 411 static inline u16
 412 __btree_node_key_to_offset(const struct btree *b, const struct bkey_packed *k)
 413 {
 414         return __btree_node_ptr_to_offset(b, k);
 415 }
 416
 417 static inline struct bkey_packed *
 418 __btree_node_offset_to_key(const struct btree *b, u16 k)
 419 {
 420         return __btree_node_offset_to_ptr(b, k);
 421 }
 422
 423 static inline unsigned btree_bkey_first_offset(const struct bset_tree *t)
 424 {
 425         return t->data_offset + offsetof(struct bset, _data) / sizeof(u64);
 426 }
 427
 428 #define btree_bkey_first(_b, _t)                                        \
 429 ({                                                                      \
 430         EBUG_ON(bset(_b, _t)->start !=                                  \
 431                 __btree_node_offset_to_key(_b, btree_bkey_first_offset(_t)));\
 432                                                                         \
 433         bset(_b, _t)->start;                                            \
 434 })
 435
 436 #define btree_bkey_last(_b, _t)                                         \
 437 ({                                                                      \
 438         EBUG_ON(__btree_node_offset_to_key(_b, (_t)->end_offset) !=     \
 439                 vstruct_last(bset(_b, _t)));                            \
 440                                                                         \
 441         __btree_node_offset_to_key(_b, (_t)->end_offset);               \
 442 })
 443
 444 static inline unsigned bset_u64s(struct bset_tree *t)
 445 {
 446         return t->end_offset - t->data_offset -
 447                 sizeof(struct bset) / sizeof(u64);
 448 }
 449
 450 static inline unsigned bset_dead_u64s(struct btree *b, struct bset_tree *t)
 451 {
 452         return bset_u64s(t) - b->nr.bset_u64s[t - b->set];
 453 }
 454
 455 static inline unsigned bset_byte_offset(struct btree *b, void *i)
 456 {
 457         return i - (void *) b->data;
 458 }
 459
 460 enum btree_node_type {
 461 #define x(kwd, val, name) BKEY_TYPE_##kwd = val,
 462         BCH_BTREE_IDS()
 463 #undef x
 464         BKEY_TYPE_BTREE,
 465 };
 466
 467 /* Type of a key in btree @id at level @level: */
 468 static inline enum btree_node_type __btree_node_type(unsigned level, enum btree_id id)
 469 {
 470         return level ? BKEY_TYPE_BTREE : (enum btree_node_type) id;
 471 }
 472
 473 /* Type of keys @b contains: */
 474 static inline enum btree_node_type btree_node_type(struct btree *b)
 475 {
 476         return __btree_node_type(b->level, b->btree_id);
 477 }
 478
 479 static inline bool btree_node_type_is_extents(enum btree_node_type type)
 480 {
 481         switch (type) {
 482         case BKEY_TYPE_EXTENTS:
 483         case BKEY_TYPE_REFLINK:
 484                 return true;
 485         default:
 486                 return false;
 487         }
 488 }
 489
 490 static inline bool btree_node_is_extents(struct btree *b)
 491 {
 492         return btree_node_type_is_extents(btree_node_type(b));
 493 }
 494
 495 #define BTREE_NODE_TYPE_HAS_TRIGGERS                    \
 496         ((1U << BKEY_TYPE_EXTENTS)|                     \
 497          (1U << BKEY_TYPE_ALLOC)|                       \
 498          (1U << BKEY_TYPE_INODES)|                      \
 499          (1U << BKEY_TYPE_REFLINK)|                     \
 500          (1U << BKEY_TYPE_EC)|                          \
 501          (1U << BKEY_TYPE_BTREE))
 502
 503 #define BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS              \
 504         ((1U << BKEY_TYPE_EXTENTS)|                     \
 505          (1U << BKEY_TYPE_INODES)|                      \
 506          (1U << BKEY_TYPE_REFLINK))
 507
 508 enum btree_trigger_flags {
 509         __BTREE_TRIGGER_NORUN,          /* Don't run triggers at all */
 510         __BTREE_TRIGGER_NOOVERWRITES,   /* Don't run triggers on overwrites */
 511
 512         __BTREE_TRIGGER_INSERT,
 513         __BTREE_TRIGGER_OVERWRITE,
 514         __BTREE_TRIGGER_OVERWRITE_SPLIT,
 515
 516         __BTREE_TRIGGER_GC,
 517         __BTREE_TRIGGER_BUCKET_INVALIDATE,
 518         __BTREE_TRIGGER_ALLOC_READ,
 519         __BTREE_TRIGGER_NOATOMIC,
 520 };
 521
 522 #define BTREE_TRIGGER_NORUN             (1U << __BTREE_TRIGGER_NORUN)
 523 #define BTREE_TRIGGER_NOOVERWRITES      (1U << __BTREE_TRIGGER_NOOVERWRITES)
 524
 525 #define BTREE_TRIGGER_INSERT            (1U << __BTREE_TRIGGER_INSERT)
 526 #define BTREE_TRIGGER_OVERWRITE         (1U << __BTREE_TRIGGER_OVERWRITE)
 527 #define BTREE_TRIGGER_OVERWRITE_SPLIT   (1U << __BTREE_TRIGGER_OVERWRITE_SPLIT)
 528
 529 #define BTREE_TRIGGER_GC                (1U << __BTREE_TRIGGER_GC)
 530 #define BTREE_TRIGGER_BUCKET_INVALIDATE (1U << __BTREE_TRIGGER_BUCKET_INVALIDATE)
 531 #define BTREE_TRIGGER_ALLOC_READ        (1U << __BTREE_TRIGGER_ALLOC_READ)
 532 #define BTREE_TRIGGER_NOATOMIC          (1U << __BTREE_TRIGGER_NOATOMIC)
 533
 534 static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 535 {
 536         return BTREE_NODE_TYPE_HAS_TRIGGERS & (1U << type);
 537 }
 538
 539 struct btree_root {
 540         struct btree            *b;
 541
 542         struct btree_update     *as;
 543
 544         /* On disk root - see async splits: */
 545         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 546         u8                      level;
 547         u8                      alive;
 548         s8                      error;
 549 };
 550
 551 /*
 552  * Optional hook that will be called just prior to a btree node update, when
 553  * we're holding the write lock and we know what key is about to be overwritten:
 554  */
 555
 556 enum btree_insert_ret {
 557         BTREE_INSERT_OK,
 558         /* leaf node needs to be split */
 559         BTREE_INSERT_BTREE_NODE_FULL,
 560         BTREE_INSERT_ENOSPC,
 561         BTREE_INSERT_NEED_MARK_REPLICAS,
 562         BTREE_INSERT_NEED_JOURNAL_RES,
 563 };
 564
 565 enum btree_gc_coalesce_fail_reason {
 566         BTREE_GC_COALESCE_FAIL_RESERVE_GET,
 567         BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC,
 568         BTREE_GC_COALESCE_FAIL_FORMAT_FITS,
 569 };
 570
 571 enum btree_node_sibling {
 572         btree_prev_sib,
 573         btree_next_sib,
 574 };
 575
 576 typedef struct btree_nr_keys (*sort_fix_overlapping_fn)(struct bset *,
 577                                                         struct btree *,
 578                                                         struct btree_node_iter *);
 579
 580 #endif /* _BCACHEFS_BTREE_TYPES_H */