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 #define BTREE_UPDATE_NODES_MAX ((BTREE_MAX_DEPTH - 2) * 2 + GC_MERGE_NODES) 10 11 #define BTREE_UPDATE_JOURNAL_RES (BTREE_UPDATE_NODES_MAX * (BKEY_BTREE_PTR_U64s_MAX + 1)) 12 13 int bch2_btree_node_check_topology(struct btree_trans *, struct btree *); 14 15 #define BTREE_UPDATE_MODES() \ 16 x(none) \ 17 x(node) \ 18 x(root) \ 19 x(update) 20 21 enum btree_update_mode { 22 #define x(n) BTREE_UPDATE_##n, 23 BTREE_UPDATE_MODES() 24 #undef x 25 }; 26 27 /* 28 * Tracks an in progress split/rewrite of a btree node and the update to the 29 * parent node: 30 * 31 * When we split/rewrite a node, we do all the updates in memory without 32 * waiting for any writes to complete - we allocate the new node(s) and update 33 * the parent node, possibly recursively up to the root. 34 * 35 * The end result is that we have one or more new nodes being written - 36 * possibly several, if there were multiple splits - and then a write (updating 37 * an interior node) which will make all these new nodes visible. 38 * 39 * Additionally, as we split/rewrite nodes we free the old nodes - but the old 40 * nodes can't be freed (their space on disk can't be reclaimed) until the 41 * update to the interior node that makes the new node visible completes - 42 * until then, the old nodes are still reachable on disk. 43 * 44 */ 45 struct btree_update { 46 struct closure cl; 47 struct bch_fs *c; 48 u64 start_time; 49 unsigned long ip_started; 50 51 struct list_head list; 52 struct list_head unwritten_list; 53 54 enum btree_update_mode mode; 55 enum bch_watermark watermark; 56 unsigned nodes_written:1; 57 unsigned took_gc_lock:1; 58 59 enum btree_id btree_id; 60 unsigned update_level; 61 62 struct disk_reservation disk_res; 63 64 /* 65 * BTREE_UPDATE_node: 66 * The update that made the new nodes visible was a regular update to an 67 * existing interior node - @b. We can't write out the update to @b 68 * until the new nodes we created are finished writing, so we block @b 69 * from writing by putting this btree_interior update on the 70 * @b->write_blocked list with @write_blocked_list: 71 */ 72 struct btree *b; 73 struct list_head write_blocked_list; 74 75 /* 76 * We may be freeing nodes that were dirty, and thus had journal entries 77 * pinned: we need to transfer the oldest of those pins to the 78 * btree_update operation, and release it when the new node(s) 79 * are all persistent and reachable: 80 */ 81 struct journal_entry_pin journal; 82 83 /* Preallocated nodes we reserve when we start the update: */ 84 struct prealloc_nodes { 85 struct btree *b[BTREE_UPDATE_NODES_MAX]; 86 unsigned nr; 87 } prealloc_nodes[2]; 88 89 /* Nodes being freed: */ 90 struct keylist old_keys; 91 u64 _old_keys[BTREE_UPDATE_NODES_MAX * 92 BKEY_BTREE_PTR_U64s_MAX]; 93 94 /* Nodes being added: */ 95 struct keylist new_keys; 96 u64 _new_keys[BTREE_UPDATE_NODES_MAX * 97 BKEY_BTREE_PTR_U64s_MAX]; 98 99 /* New nodes, that will be made reachable by this update: */ 100 struct btree *new_nodes[BTREE_UPDATE_NODES_MAX]; 101 unsigned nr_new_nodes; 102 103 struct btree *old_nodes[BTREE_UPDATE_NODES_MAX]; 104 __le64 old_nodes_seq[BTREE_UPDATE_NODES_MAX]; 105 unsigned nr_old_nodes; 106 107 open_bucket_idx_t open_buckets[BTREE_UPDATE_NODES_MAX * 108 BCH_REPLICAS_MAX]; 109 open_bucket_idx_t nr_open_buckets; 110 111 unsigned journal_u64s; 112 u64 journal_entries[BTREE_UPDATE_JOURNAL_RES]; 113 114 /* Only here to reduce stack usage on recursive splits: */ 115 struct keylist parent_keys; 116 /* 117 * Enough room for btree_split's keys without realloc - btree node 118 * pointers never have crc/compression info, so we only need to acount 119 * for the pointers for three keys 120 */ 121 u64 inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3]; 122 }; 123 124 struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *, 125 struct btree_trans *, 126 struct btree *, 127 struct bkey_format); 128 129 int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned); 130 131 int bch2_btree_increase_depth(struct btree_trans *, btree_path_idx_t, unsigned); 132 133 int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t, 134 unsigned, unsigned, enum btree_node_sibling); 135 136 static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans, 137 btree_path_idx_t path_idx, 138 unsigned level, unsigned flags, 139 enum btree_node_sibling sib) 140 { 141 struct btree_path *path = trans->paths + path_idx; 142 struct btree *b; 143 144 EBUG_ON(!btree_node_locked(path, level)); 145 146 b = path->l[level].b; 147 if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold) 148 return 0; 149 150 return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib); 151 } 152 153 static inline int bch2_foreground_maybe_merge(struct btree_trans *trans, 154 btree_path_idx_t path, 155 unsigned level, 156 unsigned flags) 157 { 158 return bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 159 btree_prev_sib) ?: 160 bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 161 btree_next_sib); 162 } 163 164 int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *, 165 struct btree *, unsigned); 166 void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *); 167 int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *, 168 struct btree *, struct bkey_i *, 169 unsigned, bool); 170 int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *, 171 struct bkey_i *, unsigned, bool); 172 173 void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *); 174 void bch2_btree_root_alloc_fake(struct bch_fs *, enum btree_id, unsigned); 175 176 static inline unsigned btree_update_reserve_required(struct bch_fs *c, 177 struct btree *b) 178 { 179 unsigned depth = btree_node_root(c, b)->c.level + 1; 180 181 /* 182 * Number of nodes we might have to allocate in a worst case btree 183 * split operation - we split all the way up to the root, then allocate 184 * a new root, unless we're already at max depth: 185 */ 186 if (depth < BTREE_MAX_DEPTH) 187 return (depth - b->c.level) * 2 + 1; 188 else 189 return (depth - b->c.level) * 2 - 1; 190 } 191 192 static inline void btree_node_reset_sib_u64s(struct btree *b) 193 { 194 b->sib_u64s[0] = b->nr.live_u64s; 195 b->sib_u64s[1] = b->nr.live_u64s; 196 } 197 198 static inline void *btree_data_end(struct btree *b) 199 { 200 return (void *) b->data + btree_buf_bytes(b); 201 } 202 203 static inline struct bkey_packed *unwritten_whiteouts_start(struct btree *b) 204 { 205 return (void *) ((u64 *) btree_data_end(b) - b->whiteout_u64s); 206 } 207 208 static inline struct bkey_packed *unwritten_whiteouts_end(struct btree *b) 209 { 210 return btree_data_end(b); 211 } 212 213 static inline void *write_block(struct btree *b) 214 { 215 return (void *) b->data + (b->written << 9); 216 } 217 218 static inline bool __btree_addr_written(struct btree *b, void *p) 219 { 220 return p < write_block(b); 221 } 222 223 static inline bool bset_written(struct btree *b, struct bset *i) 224 { 225 return __btree_addr_written(b, i); 226 } 227 228 static inline bool bkey_written(struct btree *b, struct bkey_packed *k) 229 { 230 return __btree_addr_written(b, k); 231 } 232 233 static inline ssize_t __bch2_btree_u64s_remaining(struct btree *b, void *end) 234 { 235 ssize_t used = bset_byte_offset(b, end) / sizeof(u64) + 236 b->whiteout_u64s; 237 ssize_t total = btree_buf_bytes(b) >> 3; 238 239 /* Always leave one extra u64 for bch2_varint_decode: */ 240 used++; 241 242 return total - used; 243 } 244 245 static inline size_t bch2_btree_keys_u64s_remaining(struct btree *b) 246 { 247 ssize_t remaining = __bch2_btree_u64s_remaining(b, 248 btree_bkey_last(b, bset_tree_last(b))); 249 250 BUG_ON(remaining < 0); 251 252 if (bset_written(b, btree_bset_last(b))) 253 return 0; 254 255 return remaining; 256 } 257 258 #define BTREE_WRITE_SET_U64s_BITS 9 259 260 static inline unsigned btree_write_set_buffer(struct btree *b) 261 { 262 /* 263 * Could buffer up larger amounts of keys for btrees with larger keys, 264 * pending benchmarking: 265 */ 266 return 8 << BTREE_WRITE_SET_U64s_BITS; 267 } 268 269 static inline struct btree_node_entry *want_new_bset(struct bch_fs *c, struct btree *b) 270 { 271 struct bset_tree *t = bset_tree_last(b); 272 struct btree_node_entry *bne = max(write_block(b), 273 (void *) btree_bkey_last(b, bset_tree_last(b))); 274 ssize_t remaining_space = 275 __bch2_btree_u64s_remaining(b, bne->keys.start); 276 277 if (unlikely(bset_written(b, bset(b, t)))) { 278 if (remaining_space > (ssize_t) (block_bytes(c) >> 3)) 279 return bne; 280 } else { 281 if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) && 282 remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3)) 283 return bne; 284 } 285 286 return NULL; 287 } 288 289 static inline void push_whiteout(struct btree *b, struct bpos pos) 290 { 291 struct bkey_packed k; 292 293 BUG_ON(bch2_btree_keys_u64s_remaining(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_p_copy(unwritten_whiteouts_start(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 btree *b, unsigned u64s) 314 { 315 if (unlikely(btree_node_need_rewrite(b))) 316 return false; 317 318 return u64s <= bch2_btree_keys_u64s_remaining(b); 319 } 320 321 void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *); 322 323 bool bch2_btree_interior_updates_flush(struct bch_fs *); 324 325 void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *); 326 struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *, 327 struct jset_entry *, unsigned long); 328 329 void bch2_do_pending_node_rewrites(struct bch_fs *); 330 void bch2_free_pending_node_rewrites(struct bch_fs *); 331 332 void bch2_fs_btree_interior_update_exit(struct bch_fs *); 333 void bch2_fs_btree_interior_update_init_early(struct bch_fs *); 334 int bch2_fs_btree_interior_update_init(struct bch_fs *); 335 336 #endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */ 337