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
  52 struct btree_write {
  53         struct journal_entry_pin        journal;
  54 };
  55
  56 struct btree_alloc {
  57         struct open_buckets     ob;
  58         __BKEY_PADDED(k, BKEY_BTREE_PTR_VAL_U64s_MAX);
  59 };
  60
  61 struct btree_bkey_cached_common {
  62         struct six_lock         lock;
  63         u8                      level;
  64         u8                      btree_id;
  65 };
  66
  67 struct btree {
  68         struct btree_bkey_cached_common c;
  69
  70         struct rhash_head       hash;
  71         u64                     hash_val;
  72
  73         unsigned long           flags;
  74         u16                     written;
  75         u8                      nsets;
  76         u8                      nr_key_bits;
  77         u16                     version_ondisk;
  78
  79         struct bkey_format      format;
  80
  81         struct btree_node       *data;
  82         void                    *aux_data;
  83
  84         /*
  85          * Sets of sorted keys - the real btree node - plus a binary search tree
  86          *
  87          * set[0] is special; set[0]->tree, set[0]->prev and set[0]->data point
  88          * to the memory we have allocated for this btree node. Additionally,
  89          * set[0]->data points to the entire btree node as it exists on disk.
  90          */
  91         struct bset_tree        set[MAX_BSETS];
  92
  93         struct btree_nr_keys    nr;
  94         u16                     sib_u64s[2];
  95         u16                     whiteout_u64s;
  96         u8                      byte_order;
  97         u8                      unpack_fn_len;
  98
  99         struct btree_write      writes[2];
 100
 101         /* Key/pointer for this btree node */
 102         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 103
 104         /*
 105          * XXX: add a delete sequence number, so when bch2_btree_node_relock()
 106          * fails because the lock sequence number has changed - i.e. the
 107          * contents were modified - we can still relock the node if it's still
 108          * the one we want, without redoing the traversal
 109          */
 110
 111         /*
 112          * For asynchronous splits/interior node updates:
 113          * When we do a split, we allocate new child nodes and update the parent
 114          * node to point to them: we update the parent in memory immediately,
 115          * but then we must wait until the children have been written out before
 116          * the update to the parent can be written - this is a list of the
 117          * btree_updates that are blocking this node from being
 118          * written:
 119          */
 120         struct list_head        write_blocked;
 121
 122         /*
 123          * Also for asynchronous splits/interior node updates:
 124          * If a btree node isn't reachable yet, we don't want to kick off
 125          * another write - because that write also won't yet be reachable and
 126          * marking it as completed before it's reachable would be incorrect:
 127          */
 128         unsigned long           will_make_reachable;
 129
 130         struct open_buckets     ob;
 131
 132         /* lru list */
 133         struct list_head        list;
 134 };
 135
 136 struct btree_cache {
 137         struct rhashtable       table;
 138         bool                    table_init_done;
 139         /*
 140          * We never free a struct btree, except on shutdown - we just put it on
 141          * the btree_cache_freed list and reuse it later. This simplifies the
 142          * code, and it doesn't cost us much memory as the memory usage is
 143          * dominated by buffers that hold the actual btree node data and those
 144          * can be freed - and the number of struct btrees allocated is
 145          * effectively bounded.
 146          *
 147          * btree_cache_freeable effectively is a small cache - we use it because
 148          * high order page allocations can be rather expensive, and it's quite
 149          * common to delete and allocate btree nodes in quick succession. It
 150          * should never grow past ~2-3 nodes in practice.
 151          */
 152         struct mutex            lock;
 153         struct list_head        live;
 154         struct list_head        freeable;
 155         struct list_head        freed;
 156
 157         /* Number of elements in live + freeable lists */
 158         unsigned                used;
 159         unsigned                reserve;
 160         atomic_t                dirty;
 161         struct shrinker         shrink;
 162
 163         /*
 164          * If we need to allocate memory for a new btree node and that
 165          * allocation fails, we can cannibalize another node in the btree cache
 166          * to satisfy the allocation - lock to guarantee only one thread does
 167          * this at a time:
 168          */
 169         struct task_struct      *alloc_lock;
 170         struct closure_waitlist alloc_wait;
 171 };
 172
 173 struct btree_node_iter {
 174         struct btree_node_iter_set {
 175                 u16     k, end;
 176         } data[MAX_BSETS];
 177 };
 178
 179 enum btree_iter_type {
 180         BTREE_ITER_KEYS,
 181         BTREE_ITER_NODES,
 182         BTREE_ITER_CACHED,
 183 };
 184
 185 #define BTREE_ITER_TYPE                 ((1 << 2) - 1)
 186
 187 /*
 188  * Iterate over all possible positions, synthesizing deleted keys for holes:
 189  */
 190 #define BTREE_ITER_SLOTS                (1 << 2)
 191 /*
 192  * Indicates that intent locks should be taken on leaf nodes, because we expect
 193  * to be doing updates:
 194  */
 195 #define BTREE_ITER_INTENT               (1 << 3)
 196 /*
 197  * Causes the btree iterator code to prefetch additional btree nodes from disk:
 198  */
 199 #define BTREE_ITER_PREFETCH             (1 << 4)
 200 /*
 201  * Indicates that this iterator should not be reused until transaction commit,
 202  * either because a pending update references it or because the update depends
 203  * on that particular key being locked (e.g. by the str_hash code, for hash
 204  * table consistency)
 205  */
 206 #define BTREE_ITER_KEEP_UNTIL_COMMIT    (1 << 5)
 207 /*
 208  * Used in bch2_btree_iter_traverse(), to indicate whether we're searching for
 209  * @pos or the first key strictly greater than @pos
 210  */
 211 #define BTREE_ITER_IS_EXTENTS           (1 << 6)
 212 #define BTREE_ITER_ERROR                (1 << 7)
 213 #define BTREE_ITER_SET_POS_AFTER_COMMIT (1 << 8)
 214 #define BTREE_ITER_CACHED_NOFILL        (1 << 9)
 215 #define BTREE_ITER_CACHED_NOCREATE      (1 << 10)
 216 #define BTREE_ITER_NOT_EXTENTS          (1 << 11)
 217 #define BTREE_ITER_ALL_SNAPSHOTS        (1 << 12)
 218
 219 enum btree_iter_uptodate {
 220         BTREE_ITER_UPTODATE             = 0,
 221         BTREE_ITER_NEED_PEEK            = 1,
 222         BTREE_ITER_NEED_RELOCK          = 2,
 223         BTREE_ITER_NEED_TRAVERSE        = 3,
 224 };
 225
 226 #define BTREE_ITER_NO_NODE_GET_LOCKS    ((struct btree *) 1)
 227 #define BTREE_ITER_NO_NODE_DROP         ((struct btree *) 2)
 228 #define BTREE_ITER_NO_NODE_LOCK_ROOT    ((struct btree *) 3)
 229 #define BTREE_ITER_NO_NODE_UP           ((struct btree *) 4)
 230 #define BTREE_ITER_NO_NODE_DOWN         ((struct btree *) 5)
 231 #define BTREE_ITER_NO_NODE_INIT         ((struct btree *) 6)
 232 #define BTREE_ITER_NO_NODE_ERROR        ((struct btree *) 7)
 233
 234 /*
 235  * @pos                 - iterator's current position
 236  * @level               - current btree depth
 237  * @locks_want          - btree level below which we start taking intent locks
 238  * @nodes_locked        - bitmask indicating which nodes in @nodes are locked
 239  * @nodes_intent_locked - bitmask indicating which locks are intent locks
 240  */
 241 struct btree_iter {
 242         struct btree_trans      *trans;
 243         struct bpos             pos;
 244         /* what we're searching for/what the iterator actually points to: */
 245         struct bpos             real_pos;
 246         struct bpos             pos_after_commit;
 247         /* When we're filtering by snapshot, the snapshot ID we're looking for: */
 248         unsigned                snapshot;
 249
 250         u16                     flags;
 251         u8                      idx;
 252
 253         enum btree_id           btree_id:4;
 254         enum btree_iter_uptodate uptodate:4;
 255         unsigned                level:4,
 256                                 min_depth:4,
 257                                 locks_want:4,
 258                                 nodes_locked:4,
 259                                 nodes_intent_locked:4;
 260
 261         struct btree_iter_level {
 262                 struct btree    *b;
 263                 struct btree_node_iter iter;
 264                 u32             lock_seq;
 265         }                       l[BTREE_MAX_DEPTH];
 266
 267         /*
 268          * Current unpacked key - so that bch2_btree_iter_next()/
 269          * bch2_btree_iter_next_slot() can correctly advance pos.
 270          */
 271         struct bkey             k;
 272         unsigned long           ip_allocated;
 273 };
 274
 275 static inline enum btree_iter_type
 276 btree_iter_type(const struct btree_iter *iter)
 277 {
 278         return iter->flags & BTREE_ITER_TYPE;
 279 }
 280
 281 static inline bool btree_iter_is_cached(const struct btree_iter *iter)
 282 {
 283         return btree_iter_type(iter) == BTREE_ITER_CACHED;
 284 }
 285
 286 static inline struct btree_iter_level *iter_l(struct btree_iter *iter)
 287 {
 288         return iter->l + iter->level;
 289 }
 290
 291 struct btree_key_cache {
 292         struct mutex            lock;
 293         struct rhashtable       table;
 294         bool                    table_init_done;
 295         struct list_head        freed;
 296         struct shrinker         shrink;
 297         unsigned                shrink_iter;
 298
 299         size_t                  nr_freed;
 300         atomic_long_t           nr_keys;
 301         atomic_long_t           nr_dirty;
 302 };
 303
 304 struct bkey_cached_key {
 305         u32                     btree_id;
 306         struct bpos             pos;
 307 } __attribute__((packed, aligned(4)));
 308
 309 #define BKEY_CACHED_ACCESSED            0
 310 #define BKEY_CACHED_DIRTY               1
 311
 312 struct bkey_cached {
 313         struct btree_bkey_cached_common c;
 314
 315         unsigned long           flags;
 316         u8                      u64s;
 317         bool                    valid;
 318         u32                     btree_trans_barrier_seq;
 319         struct bkey_cached_key  key;
 320
 321         struct rhash_head       hash;
 322         struct list_head        list;
 323
 324         struct journal_preres   res;
 325         struct journal_entry_pin journal;
 326
 327         struct bkey_i           *k;
 328 };
 329
 330 struct btree_insert_entry {
 331         unsigned                trigger_flags;
 332         u8                      bkey_type;
 333         enum btree_id           btree_id:8;
 334         u8                      level;
 335         unsigned                trans_triggers_run:1;
 336         unsigned                is_extent:1;
 337         struct bkey_i           *k;
 338         struct btree_iter       *iter;
 339 };
 340
 341 #ifndef CONFIG_LOCKDEP
 342 #define BTREE_ITER_MAX          64
 343 #else
 344 #define BTREE_ITER_MAX          32
 345 #endif
 346
 347 struct btree_trans_commit_hook;
 348 typedef int (btree_trans_commit_hook_fn)(struct btree_trans *, struct btree_trans_commit_hook *);
 349
 350 struct btree_trans_commit_hook {
 351         btree_trans_commit_hook_fn      *fn;
 352         struct btree_trans_commit_hook  *next;
 353 };
 354
 355 struct btree_trans {
 356         struct bch_fs           *c;
 357 #ifdef CONFIG_BCACHEFS_DEBUG
 358         struct list_head        list;
 359         struct btree            *locking;
 360         unsigned                locking_iter_idx;
 361         struct bpos             locking_pos;
 362         u8                      locking_btree_id;
 363         u8                      locking_level;
 364         pid_t                   pid;
 365 #endif
 366         unsigned long           ip;
 367         int                     srcu_idx;
 368
 369         u8                      nr_updates;
 370         u8                      nr_updates2;
 371         unsigned                used_mempool:1;
 372         unsigned                error:1;
 373         unsigned                in_traverse_all:1;
 374
 375         u64                     iters_linked;
 376         u64                     iters_live;
 377         u64                     iters_touched;
 378
 379         unsigned                mem_top;
 380         unsigned                mem_bytes;
 381         void                    *mem;
 382
 383         struct btree_iter       *iters;
 384         struct btree_insert_entry *updates;
 385         struct btree_insert_entry *updates2;
 386
 387         /* update path: */
 388         struct btree_trans_commit_hook *hooks;
 389         struct jset_entry       *extra_journal_entries;
 390         unsigned                extra_journal_entry_u64s;
 391         struct journal_entry_pin *journal_pin;
 392
 393         struct journal_res      journal_res;
 394         struct journal_preres   journal_preres;
 395         u64                     *journal_seq;
 396         struct disk_reservation *disk_res;
 397         unsigned                flags;
 398         unsigned                journal_u64s;
 399         unsigned                journal_preres_u64s;
 400         struct replicas_delta_list *fs_usage_deltas;
 401 };
 402
 403 #define BTREE_FLAG(flag)                                                \
 404 static inline bool btree_node_ ## flag(struct btree *b)                 \
 405 {       return test_bit(BTREE_NODE_ ## flag, &b->flags); }              \
 406                                                                         \
 407 static inline void set_btree_node_ ## flag(struct btree *b)             \
 408 {       set_bit(BTREE_NODE_ ## flag, &b->flags); }                      \
 409                                                                         \
 410 static inline void clear_btree_node_ ## flag(struct btree *b)           \
 411 {       clear_bit(BTREE_NODE_ ## flag, &b->flags); }
 412
 413 enum btree_flags {
 414         BTREE_NODE_read_in_flight,
 415         BTREE_NODE_read_error,
 416         BTREE_NODE_dirty,
 417         BTREE_NODE_need_write,
 418         BTREE_NODE_noevict,
 419         BTREE_NODE_write_idx,
 420         BTREE_NODE_accessed,
 421         BTREE_NODE_write_in_flight,
 422         BTREE_NODE_just_written,
 423         BTREE_NODE_dying,
 424         BTREE_NODE_fake,
 425         BTREE_NODE_need_rewrite,
 426         BTREE_NODE_never_write,
 427 };
 428
 429 BTREE_FLAG(read_in_flight);
 430 BTREE_FLAG(read_error);
 431 BTREE_FLAG(need_write);
 432 BTREE_FLAG(noevict);
 433 BTREE_FLAG(write_idx);
 434 BTREE_FLAG(accessed);
 435 BTREE_FLAG(write_in_flight);
 436 BTREE_FLAG(just_written);
 437 BTREE_FLAG(dying);
 438 BTREE_FLAG(fake);
 439 BTREE_FLAG(need_rewrite);
 440 BTREE_FLAG(never_write);
 441
 442 static inline struct btree_write *btree_current_write(struct btree *b)
 443 {
 444         return b->writes + btree_node_write_idx(b);
 445 }
 446
 447 static inline struct btree_write *btree_prev_write(struct btree *b)
 448 {
 449         return b->writes + (btree_node_write_idx(b) ^ 1);
 450 }
 451
 452 static inline struct bset_tree *bset_tree_last(struct btree *b)
 453 {
 454         EBUG_ON(!b->nsets);
 455         return b->set + b->nsets - 1;
 456 }
 457
 458 static inline void *
 459 __btree_node_offset_to_ptr(const struct btree *b, u16 offset)
 460 {
 461         return (void *) ((u64 *) b->data + 1 + offset);
 462 }
 463
 464 static inline u16
 465 __btree_node_ptr_to_offset(const struct btree *b, const void *p)
 466 {
 467         u16 ret = (u64 *) p - 1 - (u64 *) b->data;
 468
 469         EBUG_ON(__btree_node_offset_to_ptr(b, ret) != p);
 470         return ret;
 471 }
 472
 473 static inline struct bset *bset(const struct btree *b,
 474                                 const struct bset_tree *t)
 475 {
 476         return __btree_node_offset_to_ptr(b, t->data_offset);
 477 }
 478
 479 static inline void set_btree_bset_end(struct btree *b, struct bset_tree *t)
 480 {
 481         t->end_offset =
 482                 __btree_node_ptr_to_offset(b, vstruct_last(bset(b, t)));
 483 }
 484
 485 static inline void set_btree_bset(struct btree *b, struct bset_tree *t,
 486                                   const struct bset *i)
 487 {
 488         t->data_offset = __btree_node_ptr_to_offset(b, i);
 489         set_btree_bset_end(b, t);
 490 }
 491
 492 static inline struct bset *btree_bset_first(struct btree *b)
 493 {
 494         return bset(b, b->set);
 495 }
 496
 497 static inline struct bset *btree_bset_last(struct btree *b)
 498 {
 499         return bset(b, bset_tree_last(b));
 500 }
 501
 502 static inline u16
 503 __btree_node_key_to_offset(const struct btree *b, const struct bkey_packed *k)
 504 {
 505         return __btree_node_ptr_to_offset(b, k);
 506 }
 507
 508 static inline struct bkey_packed *
 509 __btree_node_offset_to_key(const struct btree *b, u16 k)
 510 {
 511         return __btree_node_offset_to_ptr(b, k);
 512 }
 513
 514 static inline unsigned btree_bkey_first_offset(const struct bset_tree *t)
 515 {
 516         return t->data_offset + offsetof(struct bset, _data) / sizeof(u64);
 517 }
 518
 519 #define btree_bkey_first(_b, _t)                                        \
 520 ({                                                                      \
 521         EBUG_ON(bset(_b, _t)->start !=                                  \
 522                 __btree_node_offset_to_key(_b, btree_bkey_first_offset(_t)));\
 523                                                                         \
 524         bset(_b, _t)->start;                                            \
 525 })
 526
 527 #define btree_bkey_last(_b, _t)                                         \
 528 ({                                                                      \
 529         EBUG_ON(__btree_node_offset_to_key(_b, (_t)->end_offset) !=     \
 530                 vstruct_last(bset(_b, _t)));                            \
 531                                                                         \
 532         __btree_node_offset_to_key(_b, (_t)->end_offset);               \
 533 })
 534
 535 static inline unsigned bset_u64s(struct bset_tree *t)
 536 {
 537         return t->end_offset - t->data_offset -
 538                 sizeof(struct bset) / sizeof(u64);
 539 }
 540
 541 static inline unsigned bset_dead_u64s(struct btree *b, struct bset_tree *t)
 542 {
 543         return bset_u64s(t) - b->nr.bset_u64s[t - b->set];
 544 }
 545
 546 static inline unsigned bset_byte_offset(struct btree *b, void *i)
 547 {
 548         return i - (void *) b->data;
 549 }
 550
 551 enum btree_node_type {
 552 #define x(kwd, val) BKEY_TYPE_##kwd = val,
 553         BCH_BTREE_IDS()
 554 #undef x
 555         BKEY_TYPE_btree,
 556 };
 557
 558 /* Type of a key in btree @id at level @level: */
 559 static inline enum btree_node_type __btree_node_type(unsigned level, enum btree_id id)
 560 {
 561         return level ? BKEY_TYPE_btree : (enum btree_node_type) id;
 562 }
 563
 564 /* Type of keys @b contains: */
 565 static inline enum btree_node_type btree_node_type(struct btree *b)
 566 {
 567         return __btree_node_type(b->c.level, b->c.btree_id);
 568 }
 569
 570 static inline bool btree_node_type_is_extents(enum btree_node_type type)
 571 {
 572         switch (type) {
 573         case BKEY_TYPE_extents:
 574         case BKEY_TYPE_reflink:
 575                 return true;
 576         default:
 577                 return false;
 578         }
 579 }
 580
 581 static inline bool btree_node_is_extents(struct btree *b)
 582 {
 583         return btree_node_type_is_extents(btree_node_type(b));
 584 }
 585
 586 static inline enum btree_node_type btree_iter_key_type(struct btree_iter *iter)
 587 {
 588         return __btree_node_type(iter->level, iter->btree_id);
 589 }
 590
 591 static inline bool btree_iter_is_extents(struct btree_iter *iter)
 592 {
 593         return btree_node_type_is_extents(btree_iter_key_type(iter));
 594 }
 595
 596 #define BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS              \
 597         ((1U << BKEY_TYPE_extents)|                     \
 598          (1U << BKEY_TYPE_inodes)|                      \
 599          (1U << BKEY_TYPE_stripes)|                     \
 600          (1U << BKEY_TYPE_reflink)|                     \
 601          (1U << BKEY_TYPE_btree))
 602
 603 #define BTREE_NODE_TYPE_HAS_MEM_TRIGGERS                \
 604         ((1U << BKEY_TYPE_alloc)|                       \
 605          (1U << BKEY_TYPE_stripes))
 606
 607 #define BTREE_NODE_TYPE_HAS_TRIGGERS                    \
 608         (BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS|            \
 609          BTREE_NODE_TYPE_HAS_MEM_TRIGGERS)
 610
 611 #define BTREE_ID_HAS_SNAPSHOTS                          \
 612         ((1U << BTREE_ID_extents)|                      \
 613          (1U << BTREE_ID_inodes)|                       \
 614          (1U << BTREE_ID_dirents)|                      \
 615          (1U << BTREE_ID_xattrs))
 616
 617 static inline bool btree_type_has_snapshots(enum btree_id id)
 618 {
 619         return (1 << id) & BTREE_ID_HAS_SNAPSHOTS;
 620 }
 621
 622 enum btree_trigger_flags {
 623         __BTREE_TRIGGER_NORUN,          /* Don't run triggers at all */
 624
 625         __BTREE_TRIGGER_INSERT,
 626         __BTREE_TRIGGER_OVERWRITE,
 627         __BTREE_TRIGGER_OVERWRITE_SPLIT,
 628
 629         __BTREE_TRIGGER_GC,
 630         __BTREE_TRIGGER_BUCKET_INVALIDATE,
 631         __BTREE_TRIGGER_NOATOMIC,
 632 };
 633
 634 #define BTREE_TRIGGER_NORUN             (1U << __BTREE_TRIGGER_NORUN)
 635
 636 #define BTREE_TRIGGER_INSERT            (1U << __BTREE_TRIGGER_INSERT)
 637 #define BTREE_TRIGGER_OVERWRITE         (1U << __BTREE_TRIGGER_OVERWRITE)
 638 #define BTREE_TRIGGER_OVERWRITE_SPLIT   (1U << __BTREE_TRIGGER_OVERWRITE_SPLIT)
 639
 640 #define BTREE_TRIGGER_GC                (1U << __BTREE_TRIGGER_GC)
 641 #define BTREE_TRIGGER_BUCKET_INVALIDATE (1U << __BTREE_TRIGGER_BUCKET_INVALIDATE)
 642 #define BTREE_TRIGGER_NOATOMIC          (1U << __BTREE_TRIGGER_NOATOMIC)
 643
 644 static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 645 {
 646         return BTREE_NODE_TYPE_HAS_TRIGGERS & (1U << type);
 647 }
 648
 649 struct btree_root {
 650         struct btree            *b;
 651
 652         /* On disk root - see async splits: */
 653         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 654         u8                      level;
 655         u8                      alive;
 656         s8                      error;
 657 };
 658
 659 /*
 660  * Optional hook that will be called just prior to a btree node update, when
 661  * we're holding the write lock and we know what key is about to be overwritten:
 662  */
 663
 664 enum btree_insert_ret {
 665         BTREE_INSERT_OK,
 666         /* leaf node needs to be split */
 667         BTREE_INSERT_BTREE_NODE_FULL,
 668         BTREE_INSERT_ENOSPC,
 669         BTREE_INSERT_NEED_MARK_REPLICAS,
 670         BTREE_INSERT_NEED_JOURNAL_RES,
 671         BTREE_INSERT_NEED_JOURNAL_RECLAIM,
 672 };
 673
 674 enum btree_gc_coalesce_fail_reason {
 675         BTREE_GC_COALESCE_FAIL_RESERVE_GET,
 676         BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC,
 677         BTREE_GC_COALESCE_FAIL_FORMAT_FITS,
 678 };
 679
 680 enum btree_node_sibling {
 681         btree_prev_sib,
 682         btree_next_sib,
 683 };
 684
 685 typedef struct btree_nr_keys (*sort_fix_overlapping_fn)(struct bset *,
 686                                                         struct btree *,
 687                                                         struct btree_node_iter *);
 688
 689 #endif /* _BCACHEFS_BTREE_TYPES_H */