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

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _BCACHEFS_BTREE_UPDATE_INTERIOR_H
   3 #define _BCACHEFS_BTREE_UPDATE_INTERIOR_H
   4
   5 #include "btree_cache.h"
   6 #include "btree_locking.h"
   7 #include "btree_update.h"
   8
   9 void __bch2_btree_calc_format(struct bkey_format_state *, struct btree *);
  10 bool bch2_btree_node_format_fits(struct bch_fs *c, struct btree *,
  11                                 struct bkey_format *);
  12
  13 #define BTREE_UPDATE_NODES_MAX          ((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES)
  14
  15 #define BTREE_UPDATE_JOURNAL_RES        (BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1))
  16
  17 /*
  18  * Tracks an in progress split/rewrite of a btree node and the update to the
  19  * parent node:
  20  *
  21  * When we split/rewrite a node, we do all the updates in memory without
  22  * waiting for any writes to complete - we allocate the new node(s) and update
  23  * the parent node, possibly recursively up to the root.
  24  *
  25  * The end result is that we have one or more new nodes being written -
  26  * possibly several, if there were multiple splits - and then a write (updating
  27  * an interior node) which will make all these new nodes visible.
  28  *
  29  * Additionally, as we split/rewrite nodes we free the old nodes - but the old
  30  * nodes can't be freed (their space on disk can't be reclaimed) until the
  31  * update to the interior node that makes the new node visible completes -
  32  * until then, the old nodes are still reachable on disk.
  33  *
  34  */
  35 struct btree_update {
  36         struct closure                  cl;
  37         struct bch_fs                   *c;
  38         u64                             start_time;
  39
  40         struct list_head                list;
  41         struct list_head                unwritten_list;
  42
  43         /* What kind of update are we doing? */
  44         enum {
  45                 BTREE_INTERIOR_NO_UPDATE,
  46                 BTREE_INTERIOR_UPDATING_NODE,
  47                 BTREE_INTERIOR_UPDATING_ROOT,
  48                 BTREE_INTERIOR_UPDATING_AS,
  49         } mode;
  50
  51         unsigned                        nodes_written:1;
  52         unsigned                        took_gc_lock:1;
  53
  54         enum btree_id                   btree_id;
  55         unsigned                        update_level;
  56
  57         struct disk_reservation         disk_res;
  58         struct journal_preres           journal_preres;
  59
  60         /*
  61          * BTREE_INTERIOR_UPDATING_NODE:
  62          * The update that made the new nodes visible was a regular update to an
  63          * existing interior node - @b. We can't write out the update to @b
  64          * until the new nodes we created are finished writing, so we block @b
  65          * from writing by putting this btree_interior update on the
  66          * @b->write_blocked list with @write_blocked_list:
  67          */
  68         struct btree                    *b;
  69         struct list_head                write_blocked_list;
  70
  71         /*
  72          * We may be freeing nodes that were dirty, and thus had journal entries
  73          * pinned: we need to transfer the oldest of those pins to the
  74          * btree_update operation, and release it when the new node(s)
  75          * are all persistent and reachable:
  76          */
  77         struct journal_entry_pin        journal;
  78
  79         /* Preallocated nodes we reserve when we start the update: */
  80         struct prealloc_nodes {
  81                 struct btree            *b[BTREE_UPDATE_NODES_MAX];
  82                 unsigned                nr;
  83         }                               prealloc_nodes[2];
  84
  85         /* Nodes being freed: */
  86         struct keylist                  old_keys;
  87         u64                             _old_keys[BTREE_UPDATE_NODES_MAX *
  88                                                   BKEY_BTREE_PTR_U64s_MAX];
  89
  90         /* Nodes being added: */
  91         struct keylist                  new_keys;
  92         u64                             _new_keys[BTREE_UPDATE_NODES_MAX *
  93                                                   BKEY_BTREE_PTR_U64s_MAX];
  94
  95         /* New nodes, that will be made reachable by this update: */
  96         struct btree                    *new_nodes[BTREE_UPDATE_NODES_MAX];
  97         unsigned                        nr_new_nodes;
  98
  99         struct btree                    *old_nodes[BTREE_UPDATE_NODES_MAX];
 100         __le64                          old_nodes_seq[BTREE_UPDATE_NODES_MAX];
 101         unsigned                        nr_old_nodes;
 102
 103         open_bucket_idx_t               open_buckets[BTREE_UPDATE_NODES_MAX *
 104                                                      BCH_REPLICAS_MAX];
 105         open_bucket_idx_t               nr_open_buckets;
 106
 107         unsigned                        journal_u64s;
 108         u64                             journal_entries[BTREE_UPDATE_JOURNAL_RES];
 109
 110         /* Only here to reduce stack usage on recursive splits: */
 111         struct keylist                  parent_keys;
 112         /*
 113          * Enough room for btree_split's keys without realloc - btree node
 114          * pointers never have crc/compression info, so we only need to acount
 115          * for the pointers for three keys
 116          */
 117         u64                             inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3];
 118 };
 119
 120 struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *,
 121                                                   struct btree_trans *,
 122                                                   struct btree *,
 123                                                   struct bkey_format);
 124
 125 int bch2_btree_split_leaf(struct btree_trans *, struct btree_path *, unsigned);
 126
 127 int __bch2_foreground_maybe_merge(struct btree_trans *, struct btree_path *,
 128                                   unsigned, unsigned, enum btree_node_sibling);
 129
 130 static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans,
 131                                         struct btree_path *path,
 132                                         unsigned level, unsigned flags,
 133                                         enum btree_node_sibling sib)
 134 {
 135         struct btree *b;
 136
 137         EBUG_ON(!btree_node_locked(path, level));
 138
 139         b = path->l[level].b;
 140         if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold)
 141                 return 0;
 142
 143         return __bch2_foreground_maybe_merge(trans, path, level, flags, sib);
 144 }
 145
 146 static inline int bch2_foreground_maybe_merge(struct btree_trans *trans,
 147                                               struct btree_path *path,
 148                                               unsigned level,
 149                                               unsigned flags)
 150 {
 151         return  bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
 152                                                     btree_prev_sib) ?:
 153                 bch2_foreground_maybe_merge_sibling(trans, path, level, flags,
 154                                                     btree_next_sib);
 155 }
 156
 157 int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *,
 158                             struct btree *, unsigned);
 159 void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *);
 160 int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *,
 161                                struct btree *, struct bkey_i *,
 162                                unsigned, bool);
 163 int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *,
 164                                         struct bkey_i *, unsigned, bool);
 165
 166 void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *);
 167 void bch2_btree_root_alloc(struct bch_fs *, enum btree_id);
 168
 169 static inline unsigned btree_update_reserve_required(struct bch_fs *c,
 170                                                      struct btree *b)
 171 {
 172         unsigned depth = btree_node_root(c, b)->c.level + 1;
 173
 174         /*
 175          * Number of nodes we might have to allocate in a worst case btree
 176          * split operation - we split all the way up to the root, then allocate
 177          * a new root, unless we're already at max depth:
 178          */
 179         if (depth < BTREE_MAX_DEPTH)
 180                 return (depth - b->c.level) * 2 + 1;
 181         else
 182                 return (depth - b->c.level) * 2 - 1;
 183 }
 184
 185 static inline void btree_node_reset_sib_u64s(struct btree *b)
 186 {
 187         b->sib_u64s[0] = b->nr.live_u64s;
 188         b->sib_u64s[1] = b->nr.live_u64s;
 189 }
 190
 191 static inline void *btree_data_end(struct bch_fs *c, struct btree *b)
 192 {
 193         return (void *) b->data + btree_bytes(c);
 194 }
 195
 196 static inline struct bkey_packed *unwritten_whiteouts_start(struct bch_fs *c,
 197                                                             struct btree *b)
 198 {
 199         return (void *) ((u64 *) btree_data_end(c, b) - b->whiteout_u64s);
 200 }
 201
 202 static inline struct bkey_packed *unwritten_whiteouts_end(struct bch_fs *c,
 203                                                           struct btree *b)
 204 {
 205         return btree_data_end(c, b);
 206 }
 207
 208 static inline void *write_block(struct btree *b)
 209 {
 210         return (void *) b->data + (b->written << 9);
 211 }
 212
 213 static inline bool __btree_addr_written(struct btree *b, void *p)
 214 {
 215         return p < write_block(b);
 216 }
 217
 218 static inline bool bset_written(struct btree *b, struct bset *i)
 219 {
 220         return __btree_addr_written(b, i);
 221 }
 222
 223 static inline bool bkey_written(struct btree *b, struct bkey_packed *k)
 224 {
 225         return __btree_addr_written(b, k);
 226 }
 227
 228 static inline ssize_t __bch_btree_u64s_remaining(struct bch_fs *c,
 229                                                  struct btree *b,
 230                                                  void *end)
 231 {
 232         ssize_t used = bset_byte_offset(b, end) / sizeof(u64) +
 233                 b->whiteout_u64s;
 234         ssize_t total = c->opts.btree_node_size >> 3;
 235
 236         /* Always leave one extra u64 for bch2_varint_decode: */
 237         used++;
 238
 239         return total - used;
 240 }
 241
 242 static inline size_t bch_btree_keys_u64s_remaining(struct bch_fs *c,
 243                                                    struct btree *b)
 244 {
 245         ssize_t remaining = __bch_btree_u64s_remaining(c, b,
 246                                 btree_bkey_last(b, bset_tree_last(b)));
 247
 248         BUG_ON(remaining < 0);
 249
 250         if (bset_written(b, btree_bset_last(b)))
 251                 return 0;
 252
 253         return remaining;
 254 }
 255
 256 #define BTREE_WRITE_SET_U64s_BITS       9
 257
 258 static inline unsigned btree_write_set_buffer(struct btree *b)
 259 {
 260         /*
 261          * Could buffer up larger amounts of keys for btrees with larger keys,
 262          * pending benchmarking:
 263          */
 264         return 8 << BTREE_WRITE_SET_U64s_BITS;
 265 }
 266
 267 static inline struct btree_node_entry *want_new_bset(struct bch_fs *c,
 268                                                      struct btree *b)
 269 {
 270         struct bset_tree *t = bset_tree_last(b);
 271         struct btree_node_entry *bne = max(write_block(b),
 272                         (void *) btree_bkey_last(b, bset_tree_last(b)));
 273         ssize_t remaining_space =
 274                 __bch_btree_u64s_remaining(c, b, &bne->keys.start[0]);
 275
 276         if (unlikely(bset_written(b, bset(b, t)))) {
 277                 if (remaining_space > (ssize_t) (block_bytes(c) >> 3))
 278                         return bne;
 279         } else {
 280                 if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) &&
 281                     remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3))
 282                         return bne;
 283         }
 284
 285         return NULL;
 286 }
 287
 288 static inline void push_whiteout(struct bch_fs *c, struct btree *b,
 289                                  struct bpos pos)
 290 {
 291         struct bkey_packed k;
 292
 293         BUG_ON(bch_btree_keys_u64s_remaining(c, b) < BKEY_U64s);
 294         EBUG_ON(btree_node_just_written(b));
 295
 296         if (!bkey_pack_pos(&k, pos, b)) {
 297                 struct bkey *u = (void *) &k;
 298
 299                 bkey_init(u);
 300                 u->p = pos;
 301         }
 302
 303         k.needs_whiteout = true;
 304
 305         b->whiteout_u64s += k.u64s;
 306         bkey_copy(unwritten_whiteouts_start(c, b), &k);
 307 }
 308
 309 /*
 310  * write lock must be held on @b (else the dirty bset that we were going to
 311  * insert into could be written out from under us)
 312  */
 313 static inline bool bch2_btree_node_insert_fits(struct bch_fs *c,
 314                                                struct btree *b, unsigned u64s)
 315 {
 316         if (unlikely(btree_node_need_rewrite(b)))
 317                 return false;
 318
 319         return u64s <= bch_btree_keys_u64s_remaining(c, b);
 320 }
 321
 322 void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *);
 323
 324 bool bch2_btree_interior_updates_flush(struct bch_fs *);
 325
 326 void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *);
 327 struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *,
 328                                         struct jset_entry *, struct jset_entry *);
 329
 330 void bch2_do_pending_node_rewrites(struct bch_fs *);
 331 void bch2_free_pending_node_rewrites(struct bch_fs *);
 332
 333 void bch2_fs_btree_interior_update_exit(struct bch_fs *);
 334 void bch2_fs_btree_interior_update_init_early(struct bch_fs *);
 335 int bch2_fs_btree_interior_update_init(struct bch_fs *);
 336
 337 #endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */