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 /* 14 * Tracks an in progress split/rewrite of a btree node and the update to the 15 * parent node: 16 * 17 * When we split/rewrite a node, we do all the updates in memory without 18 * waiting for any writes to complete - we allocate the new node(s) and update 19 * the parent node, possibly recursively up to the root. 20 * 21 * The end result is that we have one or more new nodes being written - 22 * possibly several, if there were multiple splits - and then a write (updating 23 * an interior node) which will make all these new nodes visible. 24 * 25 * Additionally, as we split/rewrite nodes we free the old nodes - but the old 26 * nodes can't be freed (their space on disk can't be reclaimed) until the 27 * update to the interior node that makes the new node visible completes - 28 * until then, the old nodes are still reachable on disk. 29 * 30 */ 31 struct btree_update { 32 struct closure cl; 33 struct bch_fs *c; 34 u64 start_time; 35 36 struct list_head list; 37 struct list_head unwritten_list; 38 39 /* What kind of update are we doing? */ 40 enum { 41 BTREE_INTERIOR_NO_UPDATE, 42 BTREE_INTERIOR_UPDATING_NODE, 43 BTREE_INTERIOR_UPDATING_ROOT, 44 BTREE_INTERIOR_UPDATING_AS, 45 } mode; 46 47 unsigned nodes_written:1; 48 unsigned took_gc_lock:1; 49 50 enum btree_id btree_id; 51 unsigned update_level; 52 53 struct disk_reservation disk_res; 54 55 /* 56 * BTREE_INTERIOR_UPDATING_NODE: 57 * The update that made the new nodes visible was a regular update to an 58 * existing interior node - @b. We can't write out the update to @b 59 * until the new nodes we created are finished writing, so we block @b 60 * from writing by putting this btree_interior update on the 61 * @b->write_blocked list with @write_blocked_list: 62 */ 63 struct btree *b; 64 struct list_head write_blocked_list; 65 66 /* 67 * We may be freeing nodes that were dirty, and thus had journal entries 68 * pinned: we need to transfer the oldest of those pins to the 69 * btree_update operation, and release it when the new node(s) 70 * are all persistent and reachable: 71 */ 72 struct journal_entry_pin journal; 73 74 /* Preallocated nodes we reserve when we start the update: */ 75 struct prealloc_nodes { 76 struct btree *b[BTREE_UPDATE_NODES_MAX]; 77 unsigned nr; 78 } prealloc_nodes[2]; 79 80 /* Nodes being freed: */ 81 struct keylist old_keys; 82 u64 _old_keys[BTREE_UPDATE_NODES_MAX * 83 BKEY_BTREE_PTR_U64s_MAX]; 84 85 /* Nodes being added: */ 86 struct keylist new_keys; 87 u64 _new_keys[BTREE_UPDATE_NODES_MAX * 88 BKEY_BTREE_PTR_U64s_MAX]; 89 90 /* New nodes, that will be made reachable by this update: */ 91 struct btree *new_nodes[BTREE_UPDATE_NODES_MAX]; 92 unsigned nr_new_nodes; 93 94 struct btree *old_nodes[BTREE_UPDATE_NODES_MAX]; 95 __le64 old_nodes_seq[BTREE_UPDATE_NODES_MAX]; 96 unsigned nr_old_nodes; 97 98 open_bucket_idx_t open_buckets[BTREE_UPDATE_NODES_MAX * 99 BCH_REPLICAS_MAX]; 100 open_bucket_idx_t nr_open_buckets; 101 102 unsigned journal_u64s; 103 u64 journal_entries[BTREE_UPDATE_JOURNAL_RES]; 104 105 /* Only here to reduce stack usage on recursive splits: */ 106 struct keylist parent_keys; 107 /* 108 * Enough room for btree_split's keys without realloc - btree node 109 * pointers never have crc/compression info, so we only need to acount 110 * for the pointers for three keys 111 */ 112 u64 inline_keys[BKEY_BTREE_PTR_U64s_MAX * 3]; 113 }; 114 115 struct btree *__bch2_btree_node_alloc_replacement(struct btree_update *, 116 struct btree_trans *, 117 struct btree *, 118 struct bkey_format); 119 120 int bch2_btree_split_leaf(struct btree_trans *, btree_path_idx_t, unsigned); 121 122 int bch2_btree_increase_depth(struct btree_trans *, btree_path_idx_t, unsigned); 123 124 int __bch2_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t, 125 unsigned, unsigned, enum btree_node_sibling); 126 127 static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans, 128 btree_path_idx_t path_idx, 129 unsigned level, unsigned flags, 130 enum btree_node_sibling sib) 131 { 132 struct btree_path *path = trans->paths + path_idx; 133 struct btree *b; 134 135 EBUG_ON(!btree_node_locked(path, level)); 136 137 b = path->l[level].b; 138 if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold) 139 return 0; 140 141 return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib); 142 } 143 144 static inline int bch2_foreground_maybe_merge(struct btree_trans *trans, 145 btree_path_idx_t path, 146 unsigned level, 147 unsigned flags) 148 { 149 return bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 150 btree_prev_sib) ?: 151 bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 152 btree_next_sib); 153 } 154 155 int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *, 156 struct btree *, unsigned); 157 void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *); 158 int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *, 159 struct btree *, struct bkey_i *, 160 unsigned, bool); 161 int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *, 162 struct bkey_i *, unsigned, bool); 163 164 void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *); 165 void bch2_btree_root_alloc(struct bch_fs *, enum btree_id); 166 167 static inline unsigned btree_update_reserve_required(struct bch_fs *c, 168 struct btree *b) 169 { 170 unsigned depth = btree_node_root(c, b)->c.level + 1; 171 172 /* 173 * Number of nodes we might have to allocate in a worst case btree 174 * split operation - we split all the way up to the root, then allocate 175 * a new root, unless we're already at max depth: 176 */ 177 if (depth < BTREE_MAX_DEPTH) 178 return (depth - b->c.level) * 2 + 1; 179 else 180 return (depth - b->c.level) * 2 - 1; 181 } 182 183 static inline void btree_node_reset_sib_u64s(struct btree *b) 184 { 185 b->sib_u64s[0] = b->nr.live_u64s; 186 b->sib_u64s[1] = b->nr.live_u64s; 187 } 188 189 static inline void *btree_data_end(struct btree *b) 190 { 191 return (void *) b->data + btree_buf_bytes(b); 192 } 193 194 static inline struct bkey_packed *unwritten_whiteouts_start(struct btree *b) 195 { 196 return (void *) ((u64 *) btree_data_end(b) - b->whiteout_u64s); 197 } 198 199 static inline struct bkey_packed *unwritten_whiteouts_end(struct btree *b) 200 { 201 return btree_data_end(b); 202 } 203 204 static inline void *write_block(struct btree *b) 205 { 206 return (void *) b->data + (b->written << 9); 207 } 208 209 static inline bool __btree_addr_written(struct btree *b, void *p) 210 { 211 return p < write_block(b); 212 } 213 214 static inline bool bset_written(struct btree *b, struct bset *i) 215 { 216 return __btree_addr_written(b, i); 217 } 218 219 static inline bool bkey_written(struct btree *b, struct bkey_packed *k) 220 { 221 return __btree_addr_written(b, k); 222 } 223 224 static inline ssize_t __bch2_btree_u64s_remaining(struct btree *b, void *end) 225 { 226 ssize_t used = bset_byte_offset(b, end) / sizeof(u64) + 227 b->whiteout_u64s; 228 ssize_t total = btree_buf_bytes(b) >> 3; 229 230 /* Always leave one extra u64 for bch2_varint_decode: */ 231 used++; 232 233 return total - used; 234 } 235 236 static inline size_t bch2_btree_keys_u64s_remaining(struct btree *b) 237 { 238 ssize_t remaining = __bch2_btree_u64s_remaining(b, 239 btree_bkey_last(b, bset_tree_last(b))); 240 241 BUG_ON(remaining < 0); 242 243 if (bset_written(b, btree_bset_last(b))) 244 return 0; 245 246 return remaining; 247 } 248 249 #define BTREE_WRITE_SET_U64s_BITS 9 250 251 static inline unsigned btree_write_set_buffer(struct btree *b) 252 { 253 /* 254 * Could buffer up larger amounts of keys for btrees with larger keys, 255 * pending benchmarking: 256 */ 257 return 8 << BTREE_WRITE_SET_U64s_BITS; 258 } 259 260 static inline struct btree_node_entry *want_new_bset(struct bch_fs *c, struct btree *b) 261 { 262 struct bset_tree *t = bset_tree_last(b); 263 struct btree_node_entry *bne = max(write_block(b), 264 (void *) btree_bkey_last(b, bset_tree_last(b))); 265 ssize_t remaining_space = 266 __bch2_btree_u64s_remaining(b, bne->keys.start); 267 268 if (unlikely(bset_written(b, bset(b, t)))) { 269 if (remaining_space > (ssize_t) (block_bytes(c) >> 3)) 270 return bne; 271 } else { 272 if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) && 273 remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3)) 274 return bne; 275 } 276 277 return NULL; 278 } 279 280 static inline void push_whiteout(struct btree *b, struct bpos pos) 281 { 282 struct bkey_packed k; 283 284 BUG_ON(bch2_btree_keys_u64s_remaining(b) < BKEY_U64s); 285 EBUG_ON(btree_node_just_written(b)); 286 287 if (!bkey_pack_pos(&k, pos, b)) { 288 struct bkey *u = (void *) &k; 289 290 bkey_init(u); 291 u->p = pos; 292 } 293 294 k.needs_whiteout = true; 295 296 b->whiteout_u64s += k.u64s; 297 bkey_p_copy(unwritten_whiteouts_start(b), &k); 298 } 299 300 /* 301 * write lock must be held on @b (else the dirty bset that we were going to 302 * insert into could be written out from under us) 303 */ 304 static inline bool bch2_btree_node_insert_fits(struct btree *b, unsigned u64s) 305 { 306 if (unlikely(btree_node_need_rewrite(b))) 307 return false; 308 309 return u64s <= bch2_btree_keys_u64s_remaining(b); 310 } 311 312 void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *); 313 314 bool bch2_btree_interior_updates_flush(struct bch_fs *); 315 316 void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *); 317 struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *, 318 struct jset_entry *, unsigned long); 319 320 void bch2_do_pending_node_rewrites(struct bch_fs *); 321 void bch2_free_pending_node_rewrites(struct bch_fs *); 322 323 void bch2_fs_btree_interior_update_exit(struct bch_fs *); 324 void bch2_fs_btree_interior_update_init_early(struct bch_fs *); 325 int bch2_fs_btree_interior_update_init(struct bch_fs *); 326 327 #endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */ 328