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_foreground_maybe_merge(struct btree_trans *, btree_path_idx_t, 123 unsigned, unsigned, enum btree_node_sibling); 124 125 static inline int bch2_foreground_maybe_merge_sibling(struct btree_trans *trans, 126 btree_path_idx_t path_idx, 127 unsigned level, unsigned flags, 128 enum btree_node_sibling sib) 129 { 130 struct btree_path *path = trans->paths + path_idx; 131 struct btree *b; 132 133 EBUG_ON(!btree_node_locked(path, level)); 134 135 b = path->l[level].b; 136 if (b->sib_u64s[sib] > trans->c->btree_foreground_merge_threshold) 137 return 0; 138 139 return __bch2_foreground_maybe_merge(trans, path_idx, level, flags, sib); 140 } 141 142 static inline int bch2_foreground_maybe_merge(struct btree_trans *trans, 143 btree_path_idx_t path, 144 unsigned level, 145 unsigned flags) 146 { 147 return bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 148 btree_prev_sib) ?: 149 bch2_foreground_maybe_merge_sibling(trans, path, level, flags, 150 btree_next_sib); 151 } 152 153 int bch2_btree_node_rewrite(struct btree_trans *, struct btree_iter *, 154 struct btree *, unsigned); 155 void bch2_btree_node_rewrite_async(struct bch_fs *, struct btree *); 156 int bch2_btree_node_update_key(struct btree_trans *, struct btree_iter *, 157 struct btree *, struct bkey_i *, 158 unsigned, bool); 159 int bch2_btree_node_update_key_get_iter(struct btree_trans *, struct btree *, 160 struct bkey_i *, unsigned, bool); 161 162 void bch2_btree_set_root_for_read(struct bch_fs *, struct btree *); 163 void bch2_btree_root_alloc(struct bch_fs *, enum btree_id); 164 165 static inline unsigned btree_update_reserve_required(struct bch_fs *c, 166 struct btree *b) 167 { 168 unsigned depth = btree_node_root(c, b)->c.level + 1; 169 170 /* 171 * Number of nodes we might have to allocate in a worst case btree 172 * split operation - we split all the way up to the root, then allocate 173 * a new root, unless we're already at max depth: 174 */ 175 if (depth < BTREE_MAX_DEPTH) 176 return (depth - b->c.level) * 2 + 1; 177 else 178 return (depth - b->c.level) * 2 - 1; 179 } 180 181 static inline void btree_node_reset_sib_u64s(struct btree *b) 182 { 183 b->sib_u64s[0] = b->nr.live_u64s; 184 b->sib_u64s[1] = b->nr.live_u64s; 185 } 186 187 static inline void *btree_data_end(struct btree *b) 188 { 189 return (void *) b->data + btree_buf_bytes(b); 190 } 191 192 static inline struct bkey_packed *unwritten_whiteouts_start(struct btree *b) 193 { 194 return (void *) ((u64 *) btree_data_end(b) - b->whiteout_u64s); 195 } 196 197 static inline struct bkey_packed *unwritten_whiteouts_end(struct btree *b) 198 { 199 return btree_data_end(b); 200 } 201 202 static inline void *write_block(struct btree *b) 203 { 204 return (void *) b->data + (b->written << 9); 205 } 206 207 static inline bool __btree_addr_written(struct btree *b, void *p) 208 { 209 return p < write_block(b); 210 } 211 212 static inline bool bset_written(struct btree *b, struct bset *i) 213 { 214 return __btree_addr_written(b, i); 215 } 216 217 static inline bool bkey_written(struct btree *b, struct bkey_packed *k) 218 { 219 return __btree_addr_written(b, k); 220 } 221 222 static inline ssize_t __bch2_btree_u64s_remaining(struct btree *b, void *end) 223 { 224 ssize_t used = bset_byte_offset(b, end) / sizeof(u64) + 225 b->whiteout_u64s; 226 ssize_t total = btree_buf_bytes(b) >> 3; 227 228 /* Always leave one extra u64 for bch2_varint_decode: */ 229 used++; 230 231 return total - used; 232 } 233 234 static inline size_t bch2_btree_keys_u64s_remaining(struct btree *b) 235 { 236 ssize_t remaining = __bch2_btree_u64s_remaining(b, 237 btree_bkey_last(b, bset_tree_last(b))); 238 239 BUG_ON(remaining < 0); 240 241 if (bset_written(b, btree_bset_last(b))) 242 return 0; 243 244 return remaining; 245 } 246 247 #define BTREE_WRITE_SET_U64s_BITS 9 248 249 static inline unsigned btree_write_set_buffer(struct btree *b) 250 { 251 /* 252 * Could buffer up larger amounts of keys for btrees with larger keys, 253 * pending benchmarking: 254 */ 255 return 8 << BTREE_WRITE_SET_U64s_BITS; 256 } 257 258 static inline struct btree_node_entry *want_new_bset(struct bch_fs *c, struct btree *b) 259 { 260 struct bset_tree *t = bset_tree_last(b); 261 struct btree_node_entry *bne = max(write_block(b), 262 (void *) btree_bkey_last(b, bset_tree_last(b))); 263 ssize_t remaining_space = 264 __bch2_btree_u64s_remaining(b, bne->keys.start); 265 266 if (unlikely(bset_written(b, bset(b, t)))) { 267 if (remaining_space > (ssize_t) (block_bytes(c) >> 3)) 268 return bne; 269 } else { 270 if (unlikely(bset_u64s(t) * sizeof(u64) > btree_write_set_buffer(b)) && 271 remaining_space > (ssize_t) (btree_write_set_buffer(b) >> 3)) 272 return bne; 273 } 274 275 return NULL; 276 } 277 278 static inline void push_whiteout(struct btree *b, struct bpos pos) 279 { 280 struct bkey_packed k; 281 282 BUG_ON(bch2_btree_keys_u64s_remaining(b) < BKEY_U64s); 283 EBUG_ON(btree_node_just_written(b)); 284 285 if (!bkey_pack_pos(&k, pos, b)) { 286 struct bkey *u = (void *) &k; 287 288 bkey_init(u); 289 u->p = pos; 290 } 291 292 k.needs_whiteout = true; 293 294 b->whiteout_u64s += k.u64s; 295 bkey_p_copy(unwritten_whiteouts_start(b), &k); 296 } 297 298 /* 299 * write lock must be held on @b (else the dirty bset that we were going to 300 * insert into could be written out from under us) 301 */ 302 static inline bool bch2_btree_node_insert_fits(struct btree *b, unsigned u64s) 303 { 304 if (unlikely(btree_node_need_rewrite(b))) 305 return false; 306 307 return u64s <= bch2_btree_keys_u64s_remaining(b); 308 } 309 310 void bch2_btree_updates_to_text(struct printbuf *, struct bch_fs *); 311 312 bool bch2_btree_interior_updates_flush(struct bch_fs *); 313 314 void bch2_journal_entry_to_btree_root(struct bch_fs *, struct jset_entry *); 315 struct jset_entry *bch2_btree_roots_to_journal_entries(struct bch_fs *, 316 struct jset_entry *, unsigned long); 317 318 void bch2_do_pending_node_rewrites(struct bch_fs *); 319 void bch2_free_pending_node_rewrites(struct bch_fs *); 320 321 void bch2_fs_btree_interior_update_exit(struct bch_fs *); 322 void bch2_fs_btree_interior_update_init_early(struct bch_fs *); 323 int bch2_fs_btree_interior_update_init(struct bch_fs *); 324 325 #endif /* _BCACHEFS_BTREE_UPDATE_INTERIOR_H */ 326