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 "darray.h"
  12 #include "journal_types.h"
  13
  14 struct open_bucket;
  15 struct btree_update;
  16 struct btree_trans;
  17
  18 #define MAX_BSETS               3U
  19
  20 struct btree_nr_keys {
  21
  22         /*
  23          * Amount of live metadata (i.e. size of node after a compaction) in
  24          * units of u64s
  25          */
  26         u16                     live_u64s;
  27         u16                     bset_u64s[MAX_BSETS];
  28
  29         /* live keys only: */
  30         u16                     packed_keys;
  31         u16                     unpacked_keys;
  32 };
  33
  34 struct bset_tree {
  35         /*
  36          * We construct a binary tree in an array as if the array
  37          * started at 1, so that things line up on the same cachelines
  38          * better: see comments in bset.c at cacheline_to_bkey() for
  39          * details
  40          */
  41
  42         /* size of the binary tree and prev array */
  43         u16                     size;
  44
  45         /* function of size - precalculated for to_inorder() */
  46         u16                     extra;
  47
  48         u16                     data_offset;
  49         u16                     aux_data_offset;
  50         u16                     end_offset;
  51 };
  52
  53 struct btree_write {
  54         struct journal_entry_pin        journal;
  55 };
  56
  57 struct btree_alloc {
  58         struct open_buckets     ob;
  59         __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX);
  60 };
  61
  62 struct btree_bkey_cached_common {
  63         struct six_lock         lock;
  64         u8                      level;
  65         u8                      btree_id;
  66 };
  67
  68 struct btree {
  69         struct btree_bkey_cached_common c;
  70
  71         struct rhash_head       hash;
  72         u64                     hash_val;
  73
  74         unsigned long           flags;
  75         u16                     written;
  76         u8                      nsets;
  77         u8                      nr_key_bits;
  78         u16                     version_ondisk;
  79
  80         struct bkey_format      format;
  81
  82         struct btree_node       *data;
  83         void                    *aux_data;
  84
  85         /*
  86          * Sets of sorted keys - the real btree node - plus a binary search tree
  87          *
  88          * set[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
  89          * to the memory we have allocated for this btree node. Additionally,
  90          * set[0]->data points to the entire btree node as it exists on disk.
  91          */
  92         struct bset_tree        set[MAX_BSETS];
  93
  94         struct btree_nr_keys    nr;
  95         u16                     sib_u64s[2];
  96         u16                     whiteout_u64s;
  97         u8                      byte_order;
  98         u8                      unpack_fn_len;
  99
 100         struct btree_write      writes[2];
 101
 102         /* Key/pointer for this btree node */
 103         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 104
 105         /*
 106          * XXX: add a delete sequence number, so when bch2_btree_node_relock()
 107          * fails because the lock sequence number has changed - i.e. the
 108          * contents were modified - we can still relock the node if it's still
 109          * the one we want, without redoing the traversal
 110          */
 111
 112         /*
 113          * For asynchronous splits/interior node updates:
 114          * When we do a split, we allocate new child nodes and update the parent
 115          * node to point to them: we update the parent in memory immediately,
 116          * but then we must wait until the children have been written out before
 117          * the update to the parent can be written - this is a list of the
 118          * btree_updates that are blocking this node from being
 119          * written:
 120          */
 121         struct list_head        write_blocked;
 122
 123         /*
 124          * Also for asynchronous splits/interior node updates:
 125          * If a btree node isn't reachable yet, we don't want to kick off
 126          * another write - because that write also won't yet be reachable and
 127          * marking it as completed before it's reachable would be incorrect:
 128          */
 129         unsigned long           will_make_reachable;
 130
 131         struct open_buckets     ob;
 132
 133         /* lru list */
 134         struct list_head        list;
 135 };
 136
 137 struct btree_cache {
 138         struct rhashtable       table;
 139         bool                    table_init_done;
 140         /*
 141          * We never free a struct btree, except on shutdown - we just put it on
 142          * the btree_cache_freed list and reuse it later. This simplifies the
 143          * code, and it doesn't cost us much memory as the memory usage is
 144          * dominated by buffers that hold the actual btree node data and those
 145          * can be freed - and the number of struct btrees allocated is
 146          * effectively bounded.
 147          *
 148          * btree_cache_freeable effectively is a small cache - we use it because
 149          * high order page allocations can be rather expensive, and it's quite
 150          * common to delete and allocate btree nodes in quick succession. It
 151          * should never grow past ~2-3 nodes in practice.
 152          */
 153         struct mutex            lock;
 154         struct list_head        live;
 155         struct list_head        freeable;
 156         struct list_head        freed_pcpu;
 157         struct list_head        freed_nonpcpu;
 158
 159         /* Number of elements in live + freeable lists */
 160         unsigned                used;
 161         unsigned                reserve;
 162         atomic_t                dirty;
 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 /*
 182  * Iterate over all possible positions, synthesizing deleted keys for holes:
 183  */
 184 #define BTREE_ITER_SLOTS                (1 << 0)
 185 #define BTREE_ITER_ALL_LEVELS           (1 << 1)
 186 /*
 187  * Indicates that intent locks should be taken on leaf nodes, because we expect
 188  * to be doing updates:
 189  */
 190 #define BTREE_ITER_INTENT               (1 << 2)
 191 /*
 192  * Causes the btree iterator code to prefetch additional btree nodes from disk:
 193  */
 194 #define BTREE_ITER_PREFETCH             (1 << 3)
 195 /*
 196  * Used in bch2_btree_iter_traverse(), to indicate whether we're searching for
 197  * @pos or the first key strictly greater than @pos
 198  */
 199 #define BTREE_ITER_IS_EXTENTS           (1 << 4)
 200 #define BTREE_ITER_NOT_EXTENTS          (1 << 5)
 201 #define BTREE_ITER_CACHED               (1 << 6)
 202 #define BTREE_ITER_CACHED_NOFILL        (1 << 7)
 203 #define BTREE_ITER_CACHED_NOCREATE      (1 << 8)
 204 #define BTREE_ITER_WITH_KEY_CACHE       (1 << 9)
 205 #define BTREE_ITER_WITH_UPDATES         (1 << 10)
 206 #define BTREE_ITER_WITH_JOURNAL         (1 << 11)
 207 #define __BTREE_ITER_ALL_SNAPSHOTS      (1 << 12)
 208 #define BTREE_ITER_ALL_SNAPSHOTS        (1 << 13)
 209 #define BTREE_ITER_FILTER_SNAPSHOTS     (1 << 14)
 210 #define BTREE_ITER_NOPRESERVE           (1 << 15)
 211
 212 enum btree_path_uptodate {
 213         BTREE_ITER_UPTODATE             = 0,
 214         BTREE_ITER_NEED_RELOCK          = 1,
 215         BTREE_ITER_NEED_TRAVERSE        = 2,
 216 };
 217
 218 #define BTREE_ITER_NO_NODE_GET_LOCKS    ((struct btree *) 1)
 219 #define BTREE_ITER_NO_NODE_DROP         ((struct btree *) 2)
 220 #define BTREE_ITER_NO_NODE_LOCK_ROOT    ((struct btree *) 3)
 221 #define BTREE_ITER_NO_NODE_UP           ((struct btree *) 4)
 222 #define BTREE_ITER_NO_NODE_DOWN         ((struct btree *) 5)
 223 #define BTREE_ITER_NO_NODE_INIT         ((struct btree *) 6)
 224 #define BTREE_ITER_NO_NODE_ERROR        ((struct btree *) 7)
 225 #define BTREE_ITER_NO_NODE_CACHED       ((struct btree *) 8)
 226
 227 struct btree_path {
 228         u8                      idx;
 229         u8                      sorted_idx;
 230         u8                      ref;
 231         u8                      intent_ref;
 232
 233         /* btree_iter_copy starts here: */
 234         struct bpos             pos;
 235
 236         enum btree_id           btree_id:4;
 237         bool                    cached:1;
 238         bool                    preserve:1;
 239         enum btree_path_uptodate uptodate:2;
 240         /*
 241          * When true, failing to relock this path will cause the transaction to
 242          * restart:
 243          */
 244         bool                    should_be_locked:1;
 245         unsigned                level:3,
 246                                 locks_want:4,
 247                                 nodes_locked:4,
 248                                 nodes_intent_locked:4;
 249
 250         struct btree_path_level {
 251                 struct btree    *b;
 252                 struct btree_node_iter iter;
 253                 u32             lock_seq;
 254         }                       l[BTREE_MAX_DEPTH];
 255 #ifdef CONFIG_BCACHEFS_DEBUG
 256         unsigned long           ip_allocated;
 257 #endif
 258 };
 259
 260 static inline struct btree_path_level *path_l(struct btree_path *path)
 261 {
 262         return path->l + path->level;
 263 }
 264
 265 /*
 266  * @pos                 - iterator's current position
 267  * @level               - current btree depth
 268  * @locks_want          - btree level below which we start taking intent locks
 269  * @nodes_locked        - bitmask indicating which nodes in @nodes are locked
 270  * @nodes_intent_locked - bitmask indicating which locks are intent locks
 271  */
 272 struct btree_iter {
 273         struct btree_trans      *trans;
 274         struct btree_path       *path;
 275         struct btree_path       *update_path;
 276         struct btree_path       *key_cache_path;
 277
 278         enum btree_id           btree_id:4;
 279         unsigned                min_depth:3;
 280         unsigned                advanced:1;
 281
 282         /* btree_iter_copy starts here: */
 283         u16                     flags;
 284
 285         /* When we're filtering by snapshot, the snapshot ID we're looking for: */
 286         unsigned                snapshot;
 287
 288         struct bpos             pos;
 289         struct bpos             pos_after_commit;
 290         /*
 291          * Current unpacked key - so that bch2_btree_iter_next()/
 292          * bch2_btree_iter_next_slot() can correctly advance pos.
 293          */
 294         struct bkey             k;
 295 #ifdef CONFIG_BCACHEFS_DEBUG
 296         unsigned long           ip_allocated;
 297 #endif
 298 };
 299
 300 struct btree_key_cache {
 301         struct mutex            lock;
 302         struct rhashtable       table;
 303         bool                    table_init_done;
 304         struct list_head        freed;
 305         struct shrinker         shrink;
 306         unsigned                shrink_iter;
 307
 308         size_t                  nr_freed;
 309         atomic_long_t           nr_keys;
 310         atomic_long_t           nr_dirty;
 311 };
 312
 313 struct bkey_cached_key {
 314         u32                     btree_id;
 315         struct bpos             pos;
 316 } __attribute__((packed, aligned(4)));
 317
 318 #define BKEY_CACHED_ACCESSED            0
 319 #define BKEY_CACHED_DIRTY               1
 320
 321 struct bkey_cached {
 322         struct btree_bkey_cached_common c;
 323
 324         unsigned long           flags;
 325         u16                     u64s;
 326         bool                    valid;
 327         u32                     btree_trans_barrier_seq;
 328         struct bkey_cached_key  key;
 329
 330         struct rhash_head       hash;
 331         struct list_head        list;
 332
 333         struct journal_preres   res;
 334         struct journal_entry_pin journal;
 335
 336         struct bkey_i           *k;
 337 };
 338
 339 struct btree_insert_entry {
 340         unsigned                flags;
 341         u8                      bkey_type;
 342         enum btree_id           btree_id:8;
 343         u8                      level:4;
 344         bool                    cached:1;
 345         bool                    insert_trigger_run:1;
 346         bool                    overwrite_trigger_run:1;
 347         /*
 348          * @old_k may be a key from the journal; @old_btree_u64s always refers
 349          * to the size of the key being overwritten in the btree:
 350          */
 351         u8                      old_btree_u64s;
 352         struct bkey_i           *k;
 353         struct btree_path       *path;
 354         /* key being overwritten: */
 355         struct bkey             old_k;
 356         const struct bch_val    *old_v;
 357         unsigned long           ip_allocated;
 358 };
 359
 360 #ifndef CONFIG_LOCKDEP
 361 #define BTREE_ITER_MAX          64
 362 #else
 363 #define BTREE_ITER_MAX          32
 364 #endif
 365
 366 struct btree_trans_commit_hook;
 367 typedef int (btree_trans_commit_hook_fn)(struct btree_trans *, struct btree_trans_commit_hook *);
 368
 369 struct btree_trans_commit_hook {
 370         btree_trans_commit_hook_fn      *fn;
 371         struct btree_trans_commit_hook  *next;
 372 };
 373
 374 #define BTREE_TRANS_MEM_MAX     (1U << 14)
 375
 376 struct btree_trans {
 377         struct bch_fs           *c;
 378         const char              *fn;
 379         struct list_head        list;
 380         struct btree            *locking;
 381         unsigned                locking_path_idx;
 382         struct bpos             locking_pos;
 383         u8                      locking_btree_id;
 384         u8                      locking_level;
 385         u8                      locking_lock_type;
 386         pid_t                   pid;
 387         int                     srcu_idx;
 388
 389         u8                      nr_sorted;
 390         u8                      nr_updates;
 391         u8                      traverse_all_idx;
 392         bool                    used_mempool:1;
 393         bool                    in_traverse_all:1;
 394         bool                    restarted:1;
 395         bool                    memory_allocation_failure:1;
 396         bool                    journal_transaction_names:1;
 397         bool                    is_initial_gc:1;
 398         /*
 399          * For when bch2_trans_update notices we'll be splitting a compressed
 400          * extent:
 401          */
 402         unsigned                extra_journal_res;
 403
 404         u64                     paths_allocated;
 405
 406         unsigned                mem_top;
 407         unsigned                mem_bytes;
 408         void                    *mem;
 409
 410         u8                      sorted[BTREE_ITER_MAX];
 411         struct btree_path       *paths;
 412         struct btree_insert_entry *updates;
 413
 414         /* update path: */
 415         struct btree_trans_commit_hook *hooks;
 416         DARRAY(u64)             extra_journal_entries;
 417         struct journal_entry_pin *journal_pin;
 418
 419         struct journal_res      journal_res;
 420         struct journal_preres   journal_preres;
 421         u64                     *journal_seq;
 422         struct disk_reservation *disk_res;
 423         unsigned                flags;
 424         unsigned                journal_u64s;
 425         unsigned                journal_preres_u64s;
 426         struct replicas_delta_list *fs_usage_deltas;
 427 };
 428
 429 #define BTREE_FLAGS()                                                   \
 430         x(read_in_flight)                                               \
 431         x(read_error)                                                   \
 432         x(dirty)                                                        \
 433         x(need_write)                                                   \
 434         x(write_blocked)                                                \
 435         x(will_make_reachable)                                          \
 436         x(noevict)                                                      \
 437         x(write_idx)                                                    \
 438         x(accessed)                                                     \
 439         x(write_in_flight)                                              \
 440         x(write_in_flight_inner)                                        \
 441         x(just_written)                                                 \
 442         x(dying)                                                        \
 443         x(fake)                                                         \
 444         x(need_rewrite)                                                 \
 445         x(never_write)
 446
 447 enum btree_flags {
 448 #define x(flag) BTREE_NODE_##flag,
 449         BTREE_FLAGS()
 450 #undef x
 451 };
 452
 453 #define x(flag)                                                         \
 454 static inline bool btree_node_ ## flag(struct btree *b)                 \
 455 {       return test_bit(BTREE_NODE_ ## flag, &b->flags); }              \
 456                                                                         \
 457 static inline void set_btree_node_ ## flag(struct btree *b)             \
 458 {       set_bit(BTREE_NODE_ ## flag, &b->flags); }                      \
 459                                                                         \
 460 static inline void clear_btree_node_ ## flag(struct btree *b)           \
 461 {       clear_bit(BTREE_NODE_ ## flag, &b->flags); }
 462
 463 BTREE_FLAGS()
 464 #undef x
 465
 466 static inline struct btree_write *btree_current_write(struct btree *b)
 467 {
 468         return b->writes + btree_node_write_idx(b);
 469 }
 470
 471 static inline struct btree_write *btree_prev_write(struct btree *b)
 472 {
 473         return b->writes + (btree_node_write_idx(b) ^ 1);
 474 }
 475
 476 static inline struct bset_tree *bset_tree_last(struct btree *b)
 477 {
 478         EBUG_ON(!b->nsets);
 479         return b->set + b->nsets - 1;
 480 }
 481
 482 static inline void *
 483 __btree_node_offset_to_ptr(const struct btree *b, u16 offset)
 484 {
 485         return (void *) ((u64 *) b->data + 1 + offset);
 486 }
 487
 488 static inline u16
 489 __btree_node_ptr_to_offset(const struct btree *b, const void *p)
 490 {
 491         u16 ret = (u64 *) p - 1 - (u64 *) b->data;
 492
 493         EBUG_ON(__btree_node_offset_to_ptr(b, ret) != p);
 494         return ret;
 495 }
 496
 497 static inline struct bset *bset(const struct btree *b,
 498                                 const struct bset_tree *t)
 499 {
 500         return __btree_node_offset_to_ptr(b, t->data_offset);
 501 }
 502
 503 static inline void set_btree_bset_end(struct btree *b, struct bset_tree *t)
 504 {
 505         t->end_offset =
 506                 __btree_node_ptr_to_offset(b, vstruct_last(bset(b, t)));
 507 }
 508
 509 static inline void set_btree_bset(struct btree *b, struct bset_tree *t,
 510                                   const struct bset *i)
 511 {
 512         t->data_offset = __btree_node_ptr_to_offset(b, i);
 513         set_btree_bset_end(b, t);
 514 }
 515
 516 static inline struct bset *btree_bset_first(struct btree *b)
 517 {
 518         return bset(b, b->set);
 519 }
 520
 521 static inline struct bset *btree_bset_last(struct btree *b)
 522 {
 523         return bset(b, bset_tree_last(b));
 524 }
 525
 526 static inline u16
 527 __btree_node_key_to_offset(const struct btree *b, const struct bkey_packed *k)
 528 {
 529         return __btree_node_ptr_to_offset(b, k);
 530 }
 531
 532 static inline struct bkey_packed *
 533 __btree_node_offset_to_key(const struct btree *b, u16 k)
 534 {
 535         return __btree_node_offset_to_ptr(b, k);
 536 }
 537
 538 static inline unsigned btree_bkey_first_offset(const struct bset_tree *t)
 539 {
 540         return t->data_offset + offsetof(struct bset, _data) / sizeof(u64);
 541 }
 542
 543 #define btree_bkey_first(_b, _t)                                        \
 544 ({                                                                      \
 545         EBUG_ON(bset(_b, _t)->start !=                                  \
 546                 __btree_node_offset_to_key(_b, btree_bkey_first_offset(_t)));\
 547                                                                         \
 548         bset(_b, _t)->start;                                            \
 549 })
 550
 551 #define btree_bkey_last(_b, _t)                                         \
 552 ({                                                                      \
 553         EBUG_ON(__btree_node_offset_to_key(_b, (_t)->end_offset) !=     \
 554                 vstruct_last(bset(_b, _t)));                            \
 555                                                                         \
 556         __btree_node_offset_to_key(_b, (_t)->end_offset);               \
 557 })
 558
 559 static inline unsigned bset_u64s(struct bset_tree *t)
 560 {
 561         return t->end_offset - t->data_offset -
 562                 sizeof(struct bset) / sizeof(u64);
 563 }
 564
 565 static inline unsigned bset_dead_u64s(struct btree *b, struct bset_tree *t)
 566 {
 567         return bset_u64s(t) - b->nr.bset_u64s[t - b->set];
 568 }
 569
 570 static inline unsigned bset_byte_offset(struct btree *b, void *i)
 571 {
 572         return i - (void *) b->data;
 573 }
 574
 575 enum btree_node_type {
 576 #define x(kwd, val) BKEY_TYPE_##kwd = val,
 577         BCH_BTREE_IDS()
 578 #undef x
 579         BKEY_TYPE_btree,
 580 };
 581
 582 /* Type of a key in btree @id at level @level: */
 583 static inline enum btree_node_type __btree_node_type(unsigned level, enum btree_id id)
 584 {
 585         return level ? BKEY_TYPE_btree : (enum btree_node_type) id;
 586 }
 587
 588 /* Type of keys @b contains: */
 589 static inline enum btree_node_type btree_node_type(struct btree *b)
 590 {
 591         return __btree_node_type(b->c.level, b->c.btree_id);
 592 }
 593
 594 #define BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS              \
 595         ((1U << BKEY_TYPE_extents)|                     \
 596          (1U << BKEY_TYPE_alloc)|                       \
 597          (1U << BKEY_TYPE_inodes)|                      \
 598          (1U << BKEY_TYPE_stripes)|                     \
 599          (1U << BKEY_TYPE_reflink)|                     \
 600          (1U << BKEY_TYPE_btree))
 601
 602 #define BTREE_NODE_TYPE_HAS_MEM_TRIGGERS                \
 603         ((1U << BKEY_TYPE_alloc)|                       \
 604          (1U << BKEY_TYPE_inodes)|                      \
 605          (1U << BKEY_TYPE_stripes)|                     \
 606          (1U << BKEY_TYPE_snapshots))
 607
 608 #define BTREE_NODE_TYPE_HAS_TRIGGERS                    \
 609         (BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS|            \
 610          BTREE_NODE_TYPE_HAS_MEM_TRIGGERS)
 611
 612 #define BTREE_ID_IS_EXTENTS                             \
 613         ((1U << BTREE_ID_extents)|                      \
 614          (1U << BTREE_ID_reflink)|                      \
 615          (1U << BTREE_ID_freespace))
 616
 617 static inline bool btree_node_type_is_extents(enum btree_node_type type)
 618 {
 619         return (1U << type) & BTREE_ID_IS_EXTENTS;
 620 }
 621
 622 #define BTREE_ID_HAS_SNAPSHOTS                          \
 623         ((1U << BTREE_ID_extents)|                      \
 624          (1U << BTREE_ID_inodes)|                       \
 625          (1U << BTREE_ID_dirents)|                      \
 626          (1U << BTREE_ID_xattrs))
 627
 628 #define BTREE_ID_HAS_PTRS                               \
 629         ((1U << BTREE_ID_extents)|                      \
 630          (1U << BTREE_ID_reflink))
 631
 632 static inline bool btree_type_has_snapshots(enum btree_id id)
 633 {
 634         return (1 << id) & BTREE_ID_HAS_SNAPSHOTS;
 635 }
 636
 637 static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 638 {
 639         return BTREE_NODE_TYPE_HAS_TRIGGERS & (1U << type);
 640 }
 641
 642 struct btree_root {
 643         struct btree            *b;
 644
 645         /* On disk root - see async splits: */
 646         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 647         u8                      level;
 648         u8                      alive;
 649         s8                      error;
 650 };
 651
 652 enum btree_insert_ret {
 653         BTREE_INSERT_OK,
 654         /* leaf node needs to be split */
 655         BTREE_INSERT_BTREE_NODE_FULL,
 656         BTREE_INSERT_NEED_MARK_REPLICAS,
 657         BTREE_INSERT_NEED_JOURNAL_RES,
 658         BTREE_INSERT_NEED_JOURNAL_RECLAIM,
 659 };
 660
 661 enum btree_gc_coalesce_fail_reason {
 662         BTREE_GC_COALESCE_FAIL_RESERVE_GET,
 663         BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC,
 664         BTREE_GC_COALESCE_FAIL_FORMAT_FITS,
 665 };
 666
 667 enum btree_node_sibling {
 668         btree_prev_sib,
 669         btree_next_sib,
 670 };
 671
 672 #endif /* _BCACHEFS_BTREE_TYPES_H */