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_iter_uptodate uptodate:4;
 239         enum btree_id           btree_id:4;
 240         unsigned                level:4,
 241                                 locks_want:4,
 242                                 nodes_locked:4,
 243                                 nodes_intent_locked:4;
 244
 245         struct btree_iter_level {
 246                 struct btree    *b;
 247                 struct btree_node_iter iter;
 248                 u32             lock_seq;
 249         }                       l[BTREE_MAX_DEPTH];
 250
 251         /*
 252          * Current unpacked key - so that bch2_btree_iter_next()/
 253          * bch2_btree_iter_next_slot() can correctly advance pos.
 254          */
 255         struct bkey             k;
 256 };
 257
 258 static inline enum btree_iter_type btree_iter_type(struct btree_iter *iter)
 259 {
 260         return iter->flags & BTREE_ITER_TYPE;
 261 }
 262
 263 struct btree_insert_entry {
 264         unsigned                trigger_flags;
 265         unsigned                trans_triggers_run:1;
 266         struct bkey_i           *k;
 267         struct btree_iter       *iter;
 268 };
 269
 270 #define BTREE_ITER_MAX          64
 271
 272 struct btree_trans {
 273         struct bch_fs           *c;
 274         unsigned long           ip;
 275
 276         u64                     iters_linked;
 277         u64                     iters_live;
 278         u64                     iters_touched;
 279
 280         u8                      nr_iters;
 281         u8                      nr_updates;
 282         u8                      size;
 283         unsigned                used_mempool:1;
 284         unsigned                error:1;
 285         unsigned                nounlock:1;
 286         unsigned                need_reset:1;
 287
 288         unsigned                mem_top;
 289         unsigned                mem_bytes;
 290         void                    *mem;
 291
 292         struct btree_iter       *iters;
 293         struct btree_insert_entry *updates;
 294
 295         /* update path: */
 296         struct journal_res      journal_res;
 297         struct journal_preres   journal_preres;
 298         u64                     *journal_seq;
 299         struct disk_reservation *disk_res;
 300         unsigned                flags;
 301         unsigned                journal_u64s;
 302         unsigned                journal_preres_u64s;
 303         struct replicas_delta_list *fs_usage_deltas;
 304
 305         struct btree_iter       iters_onstack[2];
 306         struct btree_insert_entry updates_onstack[2];
 307 };
 308
 309 #define BTREE_FLAG(flag)                                                \
 310 static inline bool btree_node_ ## flag(struct btree *b)                 \
 311 {       return test_bit(BTREE_NODE_ ## flag, &b->flags); }              \
 312                                                                         \
 313 static inline void set_btree_node_ ## flag(struct btree *b)             \
 314 {       set_bit(BTREE_NODE_ ## flag, &b->flags); }                      \
 315                                                                         \
 316 static inline void clear_btree_node_ ## flag(struct btree *b)           \
 317 {       clear_bit(BTREE_NODE_ ## flag, &b->flags); }
 318
 319 enum btree_flags {
 320         BTREE_NODE_read_in_flight,
 321         BTREE_NODE_read_error,
 322         BTREE_NODE_dirty,
 323         BTREE_NODE_need_write,
 324         BTREE_NODE_noevict,
 325         BTREE_NODE_write_idx,
 326         BTREE_NODE_accessed,
 327         BTREE_NODE_write_in_flight,
 328         BTREE_NODE_just_written,
 329         BTREE_NODE_dying,
 330         BTREE_NODE_fake,
 331         BTREE_NODE_old_extent_overwrite,
 332 };
 333
 334 BTREE_FLAG(read_in_flight);
 335 BTREE_FLAG(read_error);
 336 BTREE_FLAG(dirty);
 337 BTREE_FLAG(need_write);
 338 BTREE_FLAG(noevict);
 339 BTREE_FLAG(write_idx);
 340 BTREE_FLAG(accessed);
 341 BTREE_FLAG(write_in_flight);
 342 BTREE_FLAG(just_written);
 343 BTREE_FLAG(dying);
 344 BTREE_FLAG(fake);
 345 BTREE_FLAG(old_extent_overwrite);
 346
 347 static inline struct btree_write *btree_current_write(struct btree *b)
 348 {
 349         return b->writes + btree_node_write_idx(b);
 350 }
 351
 352 static inline struct btree_write *btree_prev_write(struct btree *b)
 353 {
 354         return b->writes + (btree_node_write_idx(b) ^ 1);
 355 }
 356
 357 static inline struct bset_tree *bset_tree_last(struct btree *b)
 358 {
 359         EBUG_ON(!b->nsets);
 360         return b->set + b->nsets - 1;
 361 }
 362
 363 static inline void *
 364 __btree_node_offset_to_ptr(const struct btree *b, u16 offset)
 365 {
 366         return (void *) ((u64 *) b->data + 1 + offset);
 367 }
 368
 369 static inline u16
 370 __btree_node_ptr_to_offset(const struct btree *b, const void *p)
 371 {
 372         u16 ret = (u64 *) p - 1 - (u64 *) b->data;
 373
 374         EBUG_ON(__btree_node_offset_to_ptr(b, ret) != p);
 375         return ret;
 376 }
 377
 378 static inline struct bset *bset(const struct btree *b,
 379                                 const struct bset_tree *t)
 380 {
 381         return __btree_node_offset_to_ptr(b, t->data_offset);
 382 }
 383
 384 static inline void set_btree_bset_end(struct btree *b, struct bset_tree *t)
 385 {
 386         t->end_offset =
 387                 __btree_node_ptr_to_offset(b, vstruct_last(bset(b, t)));
 388 }
 389
 390 static inline void set_btree_bset(struct btree *b, struct bset_tree *t,
 391                                   const struct bset *i)
 392 {
 393         t->data_offset = __btree_node_ptr_to_offset(b, i);
 394         set_btree_bset_end(b, t);
 395 }
 396
 397 static inline struct bset *btree_bset_first(struct btree *b)
 398 {
 399         return bset(b, b->set);
 400 }
 401
 402 static inline struct bset *btree_bset_last(struct btree *b)
 403 {
 404         return bset(b, bset_tree_last(b));
 405 }
 406
 407 static inline u16
 408 __btree_node_key_to_offset(const struct btree *b, const struct bkey_packed *k)
 409 {
 410         return __btree_node_ptr_to_offset(b, k);
 411 }
 412
 413 static inline struct bkey_packed *
 414 __btree_node_offset_to_key(const struct btree *b, u16 k)
 415 {
 416         return __btree_node_offset_to_ptr(b, k);
 417 }
 418
 419 static inline unsigned btree_bkey_first_offset(const struct bset_tree *t)
 420 {
 421         return t->data_offset + offsetof(struct bset, _data) / sizeof(u64);
 422 }
 423
 424 #define btree_bkey_first(_b, _t)                                        \
 425 ({                                                                      \
 426         EBUG_ON(bset(_b, _t)->start !=                                  \
 427                 __btree_node_offset_to_key(_b, btree_bkey_first_offset(_t)));\
 428                                                                         \
 429         bset(_b, _t)->start;                                            \
 430 })
 431
 432 #define btree_bkey_last(_b, _t)                                         \
 433 ({                                                                      \
 434         EBUG_ON(__btree_node_offset_to_key(_b, (_t)->end_offset) !=     \
 435                 vstruct_last(bset(_b, _t)));                            \
 436                                                                         \
 437         __btree_node_offset_to_key(_b, (_t)->end_offset);               \
 438 })
 439
 440 static inline unsigned bset_u64s(struct bset_tree *t)
 441 {
 442         return t->end_offset - t->data_offset -
 443                 sizeof(struct bset) / sizeof(u64);
 444 }
 445
 446 static inline unsigned bset_dead_u64s(struct btree *b, struct bset_tree *t)
 447 {
 448         return bset_u64s(t) - b->nr.bset_u64s[t - b->set];
 449 }
 450
 451 static inline unsigned bset_byte_offset(struct btree *b, void *i)
 452 {
 453         return i - (void *) b->data;
 454 }
 455
 456 enum btree_node_type {
 457 #define x(kwd, val, name) BKEY_TYPE_##kwd = val,
 458         BCH_BTREE_IDS()
 459 #undef x
 460         BKEY_TYPE_BTREE,
 461 };
 462
 463 /* Type of a key in btree @id at level @level: */
 464 static inline enum btree_node_type __btree_node_type(unsigned level, enum btree_id id)
 465 {
 466         return level ? BKEY_TYPE_BTREE : (enum btree_node_type) id;
 467 }
 468
 469 /* Type of keys @b contains: */
 470 static inline enum btree_node_type btree_node_type(struct btree *b)
 471 {
 472         return __btree_node_type(b->level, b->btree_id);
 473 }
 474
 475 static inline bool btree_node_type_is_extents(enum btree_node_type type)
 476 {
 477         switch (type) {
 478         case BKEY_TYPE_EXTENTS:
 479         case BKEY_TYPE_REFLINK:
 480                 return true;
 481         default:
 482                 return false;
 483         }
 484 }
 485
 486 static inline bool btree_node_is_extents(struct btree *b)
 487 {
 488         return btree_node_type_is_extents(btree_node_type(b));
 489 }
 490
 491 #define BTREE_NODE_TYPE_HAS_TRIGGERS                    \
 492         ((1U << BKEY_TYPE_EXTENTS)|                     \
 493          (1U << BKEY_TYPE_ALLOC)|                       \
 494          (1U << BKEY_TYPE_INODES)|                      \
 495          (1U << BKEY_TYPE_REFLINK)|                     \
 496          (1U << BKEY_TYPE_EC)|                          \
 497          (1U << BKEY_TYPE_BTREE))
 498
 499 #define BTREE_NODE_TYPE_HAS_TRANS_TRIGGERS              \
 500         ((1U << BKEY_TYPE_EXTENTS)|                     \
 501          (1U << BKEY_TYPE_INODES)|                      \
 502          (1U << BKEY_TYPE_REFLINK))
 503
 504 enum btree_trigger_flags {
 505         __BTREE_TRIGGER_NORUN,          /* Don't run triggers at all */
 506         __BTREE_TRIGGER_NOOVERWRITES,   /* Don't run triggers on overwrites */
 507
 508         __BTREE_TRIGGER_INSERT,
 509         __BTREE_TRIGGER_OVERWRITE,
 510         __BTREE_TRIGGER_OVERWRITE_SPLIT,
 511
 512         __BTREE_TRIGGER_GC,
 513         __BTREE_TRIGGER_BUCKET_INVALIDATE,
 514         __BTREE_TRIGGER_ALLOC_READ,
 515         __BTREE_TRIGGER_NOATOMIC,
 516 };
 517
 518 #define BTREE_TRIGGER_NORUN             (1U << __BTREE_TRIGGER_NORUN)
 519 #define BTREE_TRIGGER_NOOVERWRITES      (1U << __BTREE_TRIGGER_NOOVERWRITES)
 520
 521 #define BTREE_TRIGGER_INSERT            (1U << __BTREE_TRIGGER_INSERT)
 522 #define BTREE_TRIGGER_OVERWRITE         (1U << __BTREE_TRIGGER_OVERWRITE)
 523 #define BTREE_TRIGGER_OVERWRITE_SPLIT   (1U << __BTREE_TRIGGER_OVERWRITE_SPLIT)
 524
 525 #define BTREE_TRIGGER_GC                (1U << __BTREE_TRIGGER_GC)
 526 #define BTREE_TRIGGER_BUCKET_INVALIDATE (1U << __BTREE_TRIGGER_BUCKET_INVALIDATE)
 527 #define BTREE_TRIGGER_ALLOC_READ        (1U << __BTREE_TRIGGER_ALLOC_READ)
 528 #define BTREE_TRIGGER_NOATOMIC          (1U << __BTREE_TRIGGER_NOATOMIC)
 529
 530 static inline bool btree_node_type_needs_gc(enum btree_node_type type)
 531 {
 532         return BTREE_NODE_TYPE_HAS_TRIGGERS & (1U << type);
 533 }
 534
 535 struct btree_root {
 536         struct btree            *b;
 537
 538         struct btree_update     *as;
 539
 540         /* On disk root - see async splits: */
 541         __BKEY_PADDED(key, BKEY_BTREE_PTR_VAL_U64s_MAX);
 542         u8                      level;
 543         u8                      alive;
 544         s8                      error;
 545 };
 546
 547 /*
 548  * Optional hook that will be called just prior to a btree node update, when
 549  * we're holding the write lock and we know what key is about to be overwritten:
 550  */
 551
 552 enum btree_insert_ret {
 553         BTREE_INSERT_OK,
 554         /* leaf node needs to be split */
 555         BTREE_INSERT_BTREE_NODE_FULL,
 556         BTREE_INSERT_ENOSPC,
 557         BTREE_INSERT_NEED_MARK_REPLICAS,
 558         BTREE_INSERT_NEED_JOURNAL_RES,
 559 };
 560
 561 enum btree_gc_coalesce_fail_reason {
 562         BTREE_GC_COALESCE_FAIL_RESERVE_GET,
 563         BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC,
 564         BTREE_GC_COALESCE_FAIL_FORMAT_FITS,
 565 };
 566
 567 enum btree_node_sibling {
 568         btree_prev_sib,
 569         btree_next_sib,
 570 };
 571
 572 typedef struct btree_nr_keys (*sort_fix_overlapping_fn)(struct bset *,
 573                                                         struct btree *,
 574                                                         struct btree_node_iter *);
 575
 576 #endif /* _BCACHEFS_BTREE_TYPES_H */