| 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Maple Tree implementation |
| 4 | * Copyright (c) 2018-2022 Oracle Corporation |
| 5 | * Authors: Liam R. Howlett <Liam.Howlett@oracle.com> |
| 6 | * Matthew Wilcox <willy@infradead.org> |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * DOC: Interesting implementation details of the Maple Tree |
| 11 | * |
| 12 | * Each node type has a number of slots for entries and a number of slots for |
| 13 | * pivots. In the case of dense nodes, the pivots are implied by the position |
| 14 | * and are simply the slot index + the minimum of the node. |
| 15 | * |
| 16 | * In regular B-Tree terms, pivots are called keys. The term pivot is used to |
| 17 | * indicate that the tree is specifying ranges, Pivots may appear in the |
| 18 | * subtree with an entry attached to the value where as keys are unique to a |
| 19 | * specific position of a B-tree. Pivot values are inclusive of the slot with |
| 20 | * the same index. |
| 21 | * |
| 22 | * |
| 23 | * The following illustrates the layout of a range64 nodes slots and pivots. |
| 24 | * |
| 25 | * |
| 26 | * Slots -> | 0 | 1 | 2 | ... | 12 | 13 | 14 | 15 | |
| 27 | * ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬ ┬ |
| 28 | * │ │ │ │ │ │ │ │ └─ Implied maximum |
| 29 | * │ │ │ │ │ │ │ └─ Pivot 14 |
| 30 | * │ │ │ │ │ │ └─ Pivot 13 |
| 31 | * │ │ │ │ │ └─ Pivot 12 |
| 32 | * │ │ │ │ └─ Pivot 11 |
| 33 | * │ │ │ └─ Pivot 2 |
| 34 | * │ │ └─ Pivot 1 |
| 35 | * │ └─ Pivot 0 |
| 36 | * └─ Implied minimum |
| 37 | * |
| 38 | * Slot contents: |
| 39 | * Internal (non-leaf) nodes contain pointers to other nodes. |
| 40 | * Leaf nodes contain entries. |
| 41 | * |
| 42 | * The location of interest is often referred to as an offset. All offsets have |
| 43 | * a slot, but the last offset has an implied pivot from the node above (or |
| 44 | * UINT_MAX for the root node. |
| 45 | * |
| 46 | * Ranges complicate certain write activities. When modifying any of |
| 47 | * the B-tree variants, it is known that one entry will either be added or |
| 48 | * deleted. When modifying the Maple Tree, one store operation may overwrite |
| 49 | * the entire data set, or one half of the tree, or the middle half of the tree. |
| 50 | * |
| 51 | */ |
| 52 | |
| 53 | |
| 54 | #include <linux/maple_tree.h> |
| 55 | #include <linux/xarray.h> |
| 56 | #include <linux/types.h> |
| 57 | #include <linux/export.h> |
| 58 | #include <linux/slab.h> |
| 59 | #include <linux/limits.h> |
| 60 | #include <asm/barrier.h> |
| 61 | |
| 62 | #define CREATE_TRACE_POINTS |
| 63 | #include <trace/events/maple_tree.h> |
| 64 | |
| 65 | #define MA_ROOT_PARENT 1 |
| 66 | |
| 67 | /* |
| 68 | * Maple state flags |
| 69 | * * MA_STATE_BULK - Bulk insert mode |
| 70 | * * MA_STATE_REBALANCE - Indicate a rebalance during bulk insert |
| 71 | * * MA_STATE_PREALLOC - Preallocated nodes, WARN_ON allocation |
| 72 | */ |
| 73 | #define MA_STATE_BULK 1 |
| 74 | #define MA_STATE_REBALANCE 2 |
| 75 | #define MA_STATE_PREALLOC 4 |
| 76 | |
| 77 | #define ma_parent_ptr(x) ((struct maple_pnode *)(x)) |
| 78 | #define ma_mnode_ptr(x) ((struct maple_node *)(x)) |
| 79 | #define ma_enode_ptr(x) ((struct maple_enode *)(x)) |
| 80 | static struct kmem_cache *maple_node_cache; |
| 81 | |
| 82 | #ifdef CONFIG_DEBUG_MAPLE_TREE |
| 83 | static const unsigned long mt_max[] = { |
| 84 | [maple_dense] = MAPLE_NODE_SLOTS, |
| 85 | [maple_leaf_64] = ULONG_MAX, |
| 86 | [maple_range_64] = ULONG_MAX, |
| 87 | [maple_arange_64] = ULONG_MAX, |
| 88 | }; |
| 89 | #define mt_node_max(x) mt_max[mte_node_type(x)] |
| 90 | #endif |
| 91 | |
| 92 | static const unsigned char mt_slots[] = { |
| 93 | [maple_dense] = MAPLE_NODE_SLOTS, |
| 94 | [maple_leaf_64] = MAPLE_RANGE64_SLOTS, |
| 95 | [maple_range_64] = MAPLE_RANGE64_SLOTS, |
| 96 | [maple_arange_64] = MAPLE_ARANGE64_SLOTS, |
| 97 | }; |
| 98 | #define mt_slot_count(x) mt_slots[mte_node_type(x)] |
| 99 | |
| 100 | static const unsigned char mt_pivots[] = { |
| 101 | [maple_dense] = 0, |
| 102 | [maple_leaf_64] = MAPLE_RANGE64_SLOTS - 1, |
| 103 | [maple_range_64] = MAPLE_RANGE64_SLOTS - 1, |
| 104 | [maple_arange_64] = MAPLE_ARANGE64_SLOTS - 1, |
| 105 | }; |
| 106 | #define mt_pivot_count(x) mt_pivots[mte_node_type(x)] |
| 107 | |
| 108 | static const unsigned char mt_min_slots[] = { |
| 109 | [maple_dense] = MAPLE_NODE_SLOTS / 2, |
| 110 | [maple_leaf_64] = (MAPLE_RANGE64_SLOTS / 2) - 2, |
| 111 | [maple_range_64] = (MAPLE_RANGE64_SLOTS / 2) - 2, |
| 112 | [maple_arange_64] = (MAPLE_ARANGE64_SLOTS / 2) - 1, |
| 113 | }; |
| 114 | #define mt_min_slot_count(x) mt_min_slots[mte_node_type(x)] |
| 115 | |
| 116 | #define MAPLE_BIG_NODE_SLOTS (MAPLE_RANGE64_SLOTS * 2 + 2) |
| 117 | #define MAPLE_BIG_NODE_GAPS (MAPLE_ARANGE64_SLOTS * 2 + 1) |
| 118 | |
| 119 | struct maple_big_node { |
| 120 | struct maple_pnode *parent; |
| 121 | unsigned long pivot[MAPLE_BIG_NODE_SLOTS - 1]; |
| 122 | union { |
| 123 | struct maple_enode *slot[MAPLE_BIG_NODE_SLOTS]; |
| 124 | struct { |
| 125 | unsigned long padding[MAPLE_BIG_NODE_GAPS]; |
| 126 | unsigned long gap[MAPLE_BIG_NODE_GAPS]; |
| 127 | }; |
| 128 | }; |
| 129 | unsigned char b_end; |
| 130 | enum maple_type type; |
| 131 | }; |
| 132 | |
| 133 | /* |
| 134 | * The maple_subtree_state is used to build a tree to replace a segment of an |
| 135 | * existing tree in a more atomic way. Any walkers of the older tree will hit a |
| 136 | * dead node and restart on updates. |
| 137 | */ |
| 138 | struct maple_subtree_state { |
| 139 | struct ma_state *orig_l; /* Original left side of subtree */ |
| 140 | struct ma_state *orig_r; /* Original right side of subtree */ |
| 141 | struct ma_state *l; /* New left side of subtree */ |
| 142 | struct ma_state *m; /* New middle of subtree (rare) */ |
| 143 | struct ma_state *r; /* New right side of subtree */ |
| 144 | struct ma_topiary *free; /* nodes to be freed */ |
| 145 | struct ma_topiary *destroy; /* Nodes to be destroyed (walked and freed) */ |
| 146 | struct maple_big_node *bn; |
| 147 | }; |
| 148 | |
| 149 | #ifdef CONFIG_KASAN_STACK |
| 150 | /* Prevent mas_wr_bnode() from exceeding the stack frame limit */ |
| 151 | #define noinline_for_kasan noinline_for_stack |
| 152 | #else |
| 153 | #define noinline_for_kasan inline |
| 154 | #endif |
| 155 | |
| 156 | /* Functions */ |
| 157 | static inline struct maple_node *mt_alloc_one(gfp_t gfp) |
| 158 | { |
| 159 | return kmem_cache_alloc(maple_node_cache, gfp); |
| 160 | } |
| 161 | |
| 162 | static inline int mt_alloc_bulk(gfp_t gfp, size_t size, void **nodes) |
| 163 | { |
| 164 | return kmem_cache_alloc_bulk(maple_node_cache, gfp, size, nodes); |
| 165 | } |
| 166 | |
| 167 | static inline void mt_free_bulk(size_t size, void __rcu **nodes) |
| 168 | { |
| 169 | kmem_cache_free_bulk(maple_node_cache, size, (void **)nodes); |
| 170 | } |
| 171 | |
| 172 | static void mt_free_rcu(struct rcu_head *head) |
| 173 | { |
| 174 | struct maple_node *node = container_of(head, struct maple_node, rcu); |
| 175 | |
| 176 | kmem_cache_free(maple_node_cache, node); |
| 177 | } |
| 178 | |
| 179 | /* |
| 180 | * ma_free_rcu() - Use rcu callback to free a maple node |
| 181 | * @node: The node to free |
| 182 | * |
| 183 | * The maple tree uses the parent pointer to indicate this node is no longer in |
| 184 | * use and will be freed. |
| 185 | */ |
| 186 | static void ma_free_rcu(struct maple_node *node) |
| 187 | { |
| 188 | WARN_ON(node->parent != ma_parent_ptr(node)); |
| 189 | call_rcu(&node->rcu, mt_free_rcu); |
| 190 | } |
| 191 | |
| 192 | static void mas_set_height(struct ma_state *mas) |
| 193 | { |
| 194 | unsigned int new_flags = mas->tree->ma_flags; |
| 195 | |
| 196 | new_flags &= ~MT_FLAGS_HEIGHT_MASK; |
| 197 | BUG_ON(mas->depth > MAPLE_HEIGHT_MAX); |
| 198 | new_flags |= mas->depth << MT_FLAGS_HEIGHT_OFFSET; |
| 199 | mas->tree->ma_flags = new_flags; |
| 200 | } |
| 201 | |
| 202 | static unsigned int mas_mt_height(struct ma_state *mas) |
| 203 | { |
| 204 | return mt_height(mas->tree); |
| 205 | } |
| 206 | |
| 207 | static inline enum maple_type mte_node_type(const struct maple_enode *entry) |
| 208 | { |
| 209 | return ((unsigned long)entry >> MAPLE_NODE_TYPE_SHIFT) & |
| 210 | MAPLE_NODE_TYPE_MASK; |
| 211 | } |
| 212 | |
| 213 | static inline bool ma_is_dense(const enum maple_type type) |
| 214 | { |
| 215 | return type < maple_leaf_64; |
| 216 | } |
| 217 | |
| 218 | static inline bool ma_is_leaf(const enum maple_type type) |
| 219 | { |
| 220 | return type < maple_range_64; |
| 221 | } |
| 222 | |
| 223 | static inline bool mte_is_leaf(const struct maple_enode *entry) |
| 224 | { |
| 225 | return ma_is_leaf(mte_node_type(entry)); |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * We also reserve values with the bottom two bits set to '10' which are |
| 230 | * below 4096 |
| 231 | */ |
| 232 | static inline bool mt_is_reserved(const void *entry) |
| 233 | { |
| 234 | return ((unsigned long)entry < MAPLE_RESERVED_RANGE) && |
| 235 | xa_is_internal(entry); |
| 236 | } |
| 237 | |
| 238 | static inline void mas_set_err(struct ma_state *mas, long err) |
| 239 | { |
| 240 | mas->node = MA_ERROR(err); |
| 241 | } |
| 242 | |
| 243 | static inline bool mas_is_ptr(struct ma_state *mas) |
| 244 | { |
| 245 | return mas->node == MAS_ROOT; |
| 246 | } |
| 247 | |
| 248 | static inline bool mas_is_start(struct ma_state *mas) |
| 249 | { |
| 250 | return mas->node == MAS_START; |
| 251 | } |
| 252 | |
| 253 | bool mas_is_err(struct ma_state *mas) |
| 254 | { |
| 255 | return xa_is_err(mas->node); |
| 256 | } |
| 257 | |
| 258 | static inline bool mas_searchable(struct ma_state *mas) |
| 259 | { |
| 260 | if (mas_is_none(mas)) |
| 261 | return false; |
| 262 | |
| 263 | if (mas_is_ptr(mas)) |
| 264 | return false; |
| 265 | |
| 266 | return true; |
| 267 | } |
| 268 | |
| 269 | static inline struct maple_node *mte_to_node(const struct maple_enode *entry) |
| 270 | { |
| 271 | return (struct maple_node *)((unsigned long)entry & ~MAPLE_NODE_MASK); |
| 272 | } |
| 273 | |
| 274 | /* |
| 275 | * mte_to_mat() - Convert a maple encoded node to a maple topiary node. |
| 276 | * @entry: The maple encoded node |
| 277 | * |
| 278 | * Return: a maple topiary pointer |
| 279 | */ |
| 280 | static inline struct maple_topiary *mte_to_mat(const struct maple_enode *entry) |
| 281 | { |
| 282 | return (struct maple_topiary *) |
| 283 | ((unsigned long)entry & ~MAPLE_NODE_MASK); |
| 284 | } |
| 285 | |
| 286 | /* |
| 287 | * mas_mn() - Get the maple state node. |
| 288 | * @mas: The maple state |
| 289 | * |
| 290 | * Return: the maple node (not encoded - bare pointer). |
| 291 | */ |
| 292 | static inline struct maple_node *mas_mn(const struct ma_state *mas) |
| 293 | { |
| 294 | return mte_to_node(mas->node); |
| 295 | } |
| 296 | |
| 297 | /* |
| 298 | * mte_set_node_dead() - Set a maple encoded node as dead. |
| 299 | * @mn: The maple encoded node. |
| 300 | */ |
| 301 | static inline void mte_set_node_dead(struct maple_enode *mn) |
| 302 | { |
| 303 | mte_to_node(mn)->parent = ma_parent_ptr(mte_to_node(mn)); |
| 304 | smp_wmb(); /* Needed for RCU */ |
| 305 | } |
| 306 | |
| 307 | /* Bit 1 indicates the root is a node */ |
| 308 | #define MAPLE_ROOT_NODE 0x02 |
| 309 | /* maple_type stored bit 3-6 */ |
| 310 | #define MAPLE_ENODE_TYPE_SHIFT 0x03 |
| 311 | /* Bit 2 means a NULL somewhere below */ |
| 312 | #define MAPLE_ENODE_NULL 0x04 |
| 313 | |
| 314 | static inline struct maple_enode *mt_mk_node(const struct maple_node *node, |
| 315 | enum maple_type type) |
| 316 | { |
| 317 | return (void *)((unsigned long)node | |
| 318 | (type << MAPLE_ENODE_TYPE_SHIFT) | MAPLE_ENODE_NULL); |
| 319 | } |
| 320 | |
| 321 | static inline void *mte_mk_root(const struct maple_enode *node) |
| 322 | { |
| 323 | return (void *)((unsigned long)node | MAPLE_ROOT_NODE); |
| 324 | } |
| 325 | |
| 326 | static inline void *mte_safe_root(const struct maple_enode *node) |
| 327 | { |
| 328 | return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE); |
| 329 | } |
| 330 | |
| 331 | static inline void *mte_set_full(const struct maple_enode *node) |
| 332 | { |
| 333 | return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL); |
| 334 | } |
| 335 | |
| 336 | static inline void *mte_clear_full(const struct maple_enode *node) |
| 337 | { |
| 338 | return (void *)((unsigned long)node | MAPLE_ENODE_NULL); |
| 339 | } |
| 340 | |
| 341 | static inline bool mte_has_null(const struct maple_enode *node) |
| 342 | { |
| 343 | return (unsigned long)node & MAPLE_ENODE_NULL; |
| 344 | } |
| 345 | |
| 346 | static inline bool ma_is_root(struct maple_node *node) |
| 347 | { |
| 348 | return ((unsigned long)node->parent & MA_ROOT_PARENT); |
| 349 | } |
| 350 | |
| 351 | static inline bool mte_is_root(const struct maple_enode *node) |
| 352 | { |
| 353 | return ma_is_root(mte_to_node(node)); |
| 354 | } |
| 355 | |
| 356 | static inline bool mas_is_root_limits(const struct ma_state *mas) |
| 357 | { |
| 358 | return !mas->min && mas->max == ULONG_MAX; |
| 359 | } |
| 360 | |
| 361 | static inline bool mt_is_alloc(struct maple_tree *mt) |
| 362 | { |
| 363 | return (mt->ma_flags & MT_FLAGS_ALLOC_RANGE); |
| 364 | } |
| 365 | |
| 366 | /* |
| 367 | * The Parent Pointer |
| 368 | * Excluding root, the parent pointer is 256B aligned like all other tree nodes. |
| 369 | * When storing a 32 or 64 bit values, the offset can fit into 5 bits. The 16 |
| 370 | * bit values need an extra bit to store the offset. This extra bit comes from |
| 371 | * a reuse of the last bit in the node type. This is possible by using bit 1 to |
| 372 | * indicate if bit 2 is part of the type or the slot. |
| 373 | * |
| 374 | * Note types: |
| 375 | * 0x??1 = Root |
| 376 | * 0x?00 = 16 bit nodes |
| 377 | * 0x010 = 32 bit nodes |
| 378 | * 0x110 = 64 bit nodes |
| 379 | * |
| 380 | * Slot size and alignment |
| 381 | * 0b??1 : Root |
| 382 | * 0b?00 : 16 bit values, type in 0-1, slot in 2-7 |
| 383 | * 0b010 : 32 bit values, type in 0-2, slot in 3-7 |
| 384 | * 0b110 : 64 bit values, type in 0-2, slot in 3-7 |
| 385 | */ |
| 386 | |
| 387 | #define MAPLE_PARENT_ROOT 0x01 |
| 388 | |
| 389 | #define MAPLE_PARENT_SLOT_SHIFT 0x03 |
| 390 | #define MAPLE_PARENT_SLOT_MASK 0xF8 |
| 391 | |
| 392 | #define MAPLE_PARENT_16B_SLOT_SHIFT 0x02 |
| 393 | #define MAPLE_PARENT_16B_SLOT_MASK 0xFC |
| 394 | |
| 395 | #define MAPLE_PARENT_RANGE64 0x06 |
| 396 | #define MAPLE_PARENT_RANGE32 0x04 |
| 397 | #define MAPLE_PARENT_NOT_RANGE16 0x02 |
| 398 | |
| 399 | /* |
| 400 | * mte_parent_shift() - Get the parent shift for the slot storage. |
| 401 | * @parent: The parent pointer cast as an unsigned long |
| 402 | * Return: The shift into that pointer to the star to of the slot |
| 403 | */ |
| 404 | static inline unsigned long mte_parent_shift(unsigned long parent) |
| 405 | { |
| 406 | /* Note bit 1 == 0 means 16B */ |
| 407 | if (likely(parent & MAPLE_PARENT_NOT_RANGE16)) |
| 408 | return MAPLE_PARENT_SLOT_SHIFT; |
| 409 | |
| 410 | return MAPLE_PARENT_16B_SLOT_SHIFT; |
| 411 | } |
| 412 | |
| 413 | /* |
| 414 | * mte_parent_slot_mask() - Get the slot mask for the parent. |
| 415 | * @parent: The parent pointer cast as an unsigned long. |
| 416 | * Return: The slot mask for that parent. |
| 417 | */ |
| 418 | static inline unsigned long mte_parent_slot_mask(unsigned long parent) |
| 419 | { |
| 420 | /* Note bit 1 == 0 means 16B */ |
| 421 | if (likely(parent & MAPLE_PARENT_NOT_RANGE16)) |
| 422 | return MAPLE_PARENT_SLOT_MASK; |
| 423 | |
| 424 | return MAPLE_PARENT_16B_SLOT_MASK; |
| 425 | } |
| 426 | |
| 427 | /* |
| 428 | * mas_parent_enum() - Return the maple_type of the parent from the stored |
| 429 | * parent type. |
| 430 | * @mas: The maple state |
| 431 | * @node: The maple_enode to extract the parent's enum |
| 432 | * Return: The node->parent maple_type |
| 433 | */ |
| 434 | static inline |
| 435 | enum maple_type mte_parent_enum(struct maple_enode *p_enode, |
| 436 | struct maple_tree *mt) |
| 437 | { |
| 438 | unsigned long p_type; |
| 439 | |
| 440 | p_type = (unsigned long)p_enode; |
| 441 | if (p_type & MAPLE_PARENT_ROOT) |
| 442 | return 0; /* Validated in the caller. */ |
| 443 | |
| 444 | p_type &= MAPLE_NODE_MASK; |
| 445 | p_type = p_type & ~(MAPLE_PARENT_ROOT | mte_parent_slot_mask(p_type)); |
| 446 | |
| 447 | switch (p_type) { |
| 448 | case MAPLE_PARENT_RANGE64: /* or MAPLE_PARENT_ARANGE64 */ |
| 449 | if (mt_is_alloc(mt)) |
| 450 | return maple_arange_64; |
| 451 | return maple_range_64; |
| 452 | } |
| 453 | |
| 454 | return 0; |
| 455 | } |
| 456 | |
| 457 | static inline |
| 458 | enum maple_type mas_parent_enum(struct ma_state *mas, struct maple_enode *enode) |
| 459 | { |
| 460 | return mte_parent_enum(ma_enode_ptr(mte_to_node(enode)->parent), mas->tree); |
| 461 | } |
| 462 | |
| 463 | /* |
| 464 | * mte_set_parent() - Set the parent node and encode the slot |
| 465 | * @enode: The encoded maple node. |
| 466 | * @parent: The encoded maple node that is the parent of @enode. |
| 467 | * @slot: The slot that @enode resides in @parent. |
| 468 | * |
| 469 | * Slot number is encoded in the enode->parent bit 3-6 or 2-6, depending on the |
| 470 | * parent type. |
| 471 | */ |
| 472 | static inline |
| 473 | void mte_set_parent(struct maple_enode *enode, const struct maple_enode *parent, |
| 474 | unsigned char slot) |
| 475 | { |
| 476 | unsigned long val = (unsigned long)parent; |
| 477 | unsigned long shift; |
| 478 | unsigned long type; |
| 479 | enum maple_type p_type = mte_node_type(parent); |
| 480 | |
| 481 | BUG_ON(p_type == maple_dense); |
| 482 | BUG_ON(p_type == maple_leaf_64); |
| 483 | |
| 484 | switch (p_type) { |
| 485 | case maple_range_64: |
| 486 | case maple_arange_64: |
| 487 | shift = MAPLE_PARENT_SLOT_SHIFT; |
| 488 | type = MAPLE_PARENT_RANGE64; |
| 489 | break; |
| 490 | default: |
| 491 | case maple_dense: |
| 492 | case maple_leaf_64: |
| 493 | shift = type = 0; |
| 494 | break; |
| 495 | } |
| 496 | |
| 497 | val &= ~MAPLE_NODE_MASK; /* Clear all node metadata in parent */ |
| 498 | val |= (slot << shift) | type; |
| 499 | mte_to_node(enode)->parent = ma_parent_ptr(val); |
| 500 | } |
| 501 | |
| 502 | /* |
| 503 | * mte_parent_slot() - get the parent slot of @enode. |
| 504 | * @enode: The encoded maple node. |
| 505 | * |
| 506 | * Return: The slot in the parent node where @enode resides. |
| 507 | */ |
| 508 | static inline unsigned int mte_parent_slot(const struct maple_enode *enode) |
| 509 | { |
| 510 | unsigned long val = (unsigned long)mte_to_node(enode)->parent; |
| 511 | |
| 512 | if (val & MA_ROOT_PARENT) |
| 513 | return 0; |
| 514 | |
| 515 | /* |
| 516 | * Okay to use MAPLE_PARENT_16B_SLOT_MASK as the last bit will be lost |
| 517 | * by shift if the parent shift is MAPLE_PARENT_SLOT_SHIFT |
| 518 | */ |
| 519 | return (val & MAPLE_PARENT_16B_SLOT_MASK) >> mte_parent_shift(val); |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * mte_parent() - Get the parent of @node. |
| 524 | * @node: The encoded maple node. |
| 525 | * |
| 526 | * Return: The parent maple node. |
| 527 | */ |
| 528 | static inline struct maple_node *mte_parent(const struct maple_enode *enode) |
| 529 | { |
| 530 | return (void *)((unsigned long) |
| 531 | (mte_to_node(enode)->parent) & ~MAPLE_NODE_MASK); |
| 532 | } |
| 533 | |
| 534 | /* |
| 535 | * ma_dead_node() - check if the @enode is dead. |
| 536 | * @enode: The encoded maple node |
| 537 | * |
| 538 | * Return: true if dead, false otherwise. |
| 539 | */ |
| 540 | static inline bool ma_dead_node(const struct maple_node *node) |
| 541 | { |
| 542 | struct maple_node *parent; |
| 543 | |
| 544 | /* Do not reorder reads from the node prior to the parent check */ |
| 545 | smp_rmb(); |
| 546 | parent = (void *)((unsigned long) node->parent & ~MAPLE_NODE_MASK); |
| 547 | return (parent == node); |
| 548 | } |
| 549 | |
| 550 | /* |
| 551 | * mte_dead_node() - check if the @enode is dead. |
| 552 | * @enode: The encoded maple node |
| 553 | * |
| 554 | * Return: true if dead, false otherwise. |
| 555 | */ |
| 556 | static inline bool mte_dead_node(const struct maple_enode *enode) |
| 557 | { |
| 558 | struct maple_node *parent, *node; |
| 559 | |
| 560 | node = mte_to_node(enode); |
| 561 | /* Do not reorder reads from the node prior to the parent check */ |
| 562 | smp_rmb(); |
| 563 | parent = mte_parent(enode); |
| 564 | return (parent == node); |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * mas_allocated() - Get the number of nodes allocated in a maple state. |
| 569 | * @mas: The maple state |
| 570 | * |
| 571 | * The ma_state alloc member is overloaded to hold a pointer to the first |
| 572 | * allocated node or to the number of requested nodes to allocate. If bit 0 is |
| 573 | * set, then the alloc contains the number of requested nodes. If there is an |
| 574 | * allocated node, then the total allocated nodes is in that node. |
| 575 | * |
| 576 | * Return: The total number of nodes allocated |
| 577 | */ |
| 578 | static inline unsigned long mas_allocated(const struct ma_state *mas) |
| 579 | { |
| 580 | if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) |
| 581 | return 0; |
| 582 | |
| 583 | return mas->alloc->total; |
| 584 | } |
| 585 | |
| 586 | /* |
| 587 | * mas_set_alloc_req() - Set the requested number of allocations. |
| 588 | * @mas: the maple state |
| 589 | * @count: the number of allocations. |
| 590 | * |
| 591 | * The requested number of allocations is either in the first allocated node, |
| 592 | * located in @mas->alloc->request_count, or directly in @mas->alloc if there is |
| 593 | * no allocated node. Set the request either in the node or do the necessary |
| 594 | * encoding to store in @mas->alloc directly. |
| 595 | */ |
| 596 | static inline void mas_set_alloc_req(struct ma_state *mas, unsigned long count) |
| 597 | { |
| 598 | if (!mas->alloc || ((unsigned long)mas->alloc & 0x1)) { |
| 599 | if (!count) |
| 600 | mas->alloc = NULL; |
| 601 | else |
| 602 | mas->alloc = (struct maple_alloc *)(((count) << 1U) | 1U); |
| 603 | return; |
| 604 | } |
| 605 | |
| 606 | mas->alloc->request_count = count; |
| 607 | } |
| 608 | |
| 609 | /* |
| 610 | * mas_alloc_req() - get the requested number of allocations. |
| 611 | * @mas: The maple state |
| 612 | * |
| 613 | * The alloc count is either stored directly in @mas, or in |
| 614 | * @mas->alloc->request_count if there is at least one node allocated. Decode |
| 615 | * the request count if it's stored directly in @mas->alloc. |
| 616 | * |
| 617 | * Return: The allocation request count. |
| 618 | */ |
| 619 | static inline unsigned int mas_alloc_req(const struct ma_state *mas) |
| 620 | { |
| 621 | if ((unsigned long)mas->alloc & 0x1) |
| 622 | return (unsigned long)(mas->alloc) >> 1; |
| 623 | else if (mas->alloc) |
| 624 | return mas->alloc->request_count; |
| 625 | return 0; |
| 626 | } |
| 627 | |
| 628 | /* |
| 629 | * ma_pivots() - Get a pointer to the maple node pivots. |
| 630 | * @node - the maple node |
| 631 | * @type - the node type |
| 632 | * |
| 633 | * In the event of a dead node, this array may be %NULL |
| 634 | * |
| 635 | * Return: A pointer to the maple node pivots |
| 636 | */ |
| 637 | static inline unsigned long *ma_pivots(struct maple_node *node, |
| 638 | enum maple_type type) |
| 639 | { |
| 640 | switch (type) { |
| 641 | case maple_arange_64: |
| 642 | return node->ma64.pivot; |
| 643 | case maple_range_64: |
| 644 | case maple_leaf_64: |
| 645 | return node->mr64.pivot; |
| 646 | case maple_dense: |
| 647 | return NULL; |
| 648 | } |
| 649 | return NULL; |
| 650 | } |
| 651 | |
| 652 | /* |
| 653 | * ma_gaps() - Get a pointer to the maple node gaps. |
| 654 | * @node - the maple node |
| 655 | * @type - the node type |
| 656 | * |
| 657 | * Return: A pointer to the maple node gaps |
| 658 | */ |
| 659 | static inline unsigned long *ma_gaps(struct maple_node *node, |
| 660 | enum maple_type type) |
| 661 | { |
| 662 | switch (type) { |
| 663 | case maple_arange_64: |
| 664 | return node->ma64.gap; |
| 665 | case maple_range_64: |
| 666 | case maple_leaf_64: |
| 667 | case maple_dense: |
| 668 | return NULL; |
| 669 | } |
| 670 | return NULL; |
| 671 | } |
| 672 | |
| 673 | /* |
| 674 | * mte_pivot() - Get the pivot at @piv of the maple encoded node. |
| 675 | * @mn: The maple encoded node. |
| 676 | * @piv: The pivot. |
| 677 | * |
| 678 | * Return: the pivot at @piv of @mn. |
| 679 | */ |
| 680 | static inline unsigned long mte_pivot(const struct maple_enode *mn, |
| 681 | unsigned char piv) |
| 682 | { |
| 683 | struct maple_node *node = mte_to_node(mn); |
| 684 | enum maple_type type = mte_node_type(mn); |
| 685 | |
| 686 | if (piv >= mt_pivots[type]) { |
| 687 | WARN_ON(1); |
| 688 | return 0; |
| 689 | } |
| 690 | switch (type) { |
| 691 | case maple_arange_64: |
| 692 | return node->ma64.pivot[piv]; |
| 693 | case maple_range_64: |
| 694 | case maple_leaf_64: |
| 695 | return node->mr64.pivot[piv]; |
| 696 | case maple_dense: |
| 697 | return 0; |
| 698 | } |
| 699 | return 0; |
| 700 | } |
| 701 | |
| 702 | /* |
| 703 | * mas_safe_pivot() - get the pivot at @piv or mas->max. |
| 704 | * @mas: The maple state |
| 705 | * @pivots: The pointer to the maple node pivots |
| 706 | * @piv: The pivot to fetch |
| 707 | * @type: The maple node type |
| 708 | * |
| 709 | * Return: The pivot at @piv within the limit of the @pivots array, @mas->max |
| 710 | * otherwise. |
| 711 | */ |
| 712 | static inline unsigned long |
| 713 | mas_safe_pivot(const struct ma_state *mas, unsigned long *pivots, |
| 714 | unsigned char piv, enum maple_type type) |
| 715 | { |
| 716 | if (piv >= mt_pivots[type]) |
| 717 | return mas->max; |
| 718 | |
| 719 | return pivots[piv]; |
| 720 | } |
| 721 | |
| 722 | /* |
| 723 | * mas_safe_min() - Return the minimum for a given offset. |
| 724 | * @mas: The maple state |
| 725 | * @pivots: The pointer to the maple node pivots |
| 726 | * @offset: The offset into the pivot array |
| 727 | * |
| 728 | * Return: The minimum range value that is contained in @offset. |
| 729 | */ |
| 730 | static inline unsigned long |
| 731 | mas_safe_min(struct ma_state *mas, unsigned long *pivots, unsigned char offset) |
| 732 | { |
| 733 | if (likely(offset)) |
| 734 | return pivots[offset - 1] + 1; |
| 735 | |
| 736 | return mas->min; |
| 737 | } |
| 738 | |
| 739 | /* |
| 740 | * mas_logical_pivot() - Get the logical pivot of a given offset. |
| 741 | * @mas: The maple state |
| 742 | * @pivots: The pointer to the maple node pivots |
| 743 | * @offset: The offset into the pivot array |
| 744 | * @type: The maple node type |
| 745 | * |
| 746 | * When there is no value at a pivot (beyond the end of the data), then the |
| 747 | * pivot is actually @mas->max. |
| 748 | * |
| 749 | * Return: the logical pivot of a given @offset. |
| 750 | */ |
| 751 | static inline unsigned long |
| 752 | mas_logical_pivot(struct ma_state *mas, unsigned long *pivots, |
| 753 | unsigned char offset, enum maple_type type) |
| 754 | { |
| 755 | unsigned long lpiv = mas_safe_pivot(mas, pivots, offset, type); |
| 756 | |
| 757 | if (likely(lpiv)) |
| 758 | return lpiv; |
| 759 | |
| 760 | if (likely(offset)) |
| 761 | return mas->max; |
| 762 | |
| 763 | return lpiv; |
| 764 | } |
| 765 | |
| 766 | /* |
| 767 | * mte_set_pivot() - Set a pivot to a value in an encoded maple node. |
| 768 | * @mn: The encoded maple node |
| 769 | * @piv: The pivot offset |
| 770 | * @val: The value of the pivot |
| 771 | */ |
| 772 | static inline void mte_set_pivot(struct maple_enode *mn, unsigned char piv, |
| 773 | unsigned long val) |
| 774 | { |
| 775 | struct maple_node *node = mte_to_node(mn); |
| 776 | enum maple_type type = mte_node_type(mn); |
| 777 | |
| 778 | BUG_ON(piv >= mt_pivots[type]); |
| 779 | switch (type) { |
| 780 | default: |
| 781 | case maple_range_64: |
| 782 | case maple_leaf_64: |
| 783 | node->mr64.pivot[piv] = val; |
| 784 | break; |
| 785 | case maple_arange_64: |
| 786 | node->ma64.pivot[piv] = val; |
| 787 | break; |
| 788 | case maple_dense: |
| 789 | break; |
| 790 | } |
| 791 | |
| 792 | } |
| 793 | |
| 794 | /* |
| 795 | * ma_slots() - Get a pointer to the maple node slots. |
| 796 | * @mn: The maple node |
| 797 | * @mt: The maple node type |
| 798 | * |
| 799 | * Return: A pointer to the maple node slots |
| 800 | */ |
| 801 | static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt) |
| 802 | { |
| 803 | switch (mt) { |
| 804 | default: |
| 805 | case maple_arange_64: |
| 806 | return mn->ma64.slot; |
| 807 | case maple_range_64: |
| 808 | case maple_leaf_64: |
| 809 | return mn->mr64.slot; |
| 810 | case maple_dense: |
| 811 | return mn->slot; |
| 812 | } |
| 813 | } |
| 814 | |
| 815 | static inline bool mt_locked(const struct maple_tree *mt) |
| 816 | { |
| 817 | return mt_external_lock(mt) ? mt_lock_is_held(mt) : |
| 818 | lockdep_is_held(&mt->ma_lock); |
| 819 | } |
| 820 | |
| 821 | static inline void *mt_slot(const struct maple_tree *mt, |
| 822 | void __rcu **slots, unsigned char offset) |
| 823 | { |
| 824 | return rcu_dereference_check(slots[offset], mt_locked(mt)); |
| 825 | } |
| 826 | |
| 827 | static inline void *mt_slot_locked(struct maple_tree *mt, void __rcu **slots, |
| 828 | unsigned char offset) |
| 829 | { |
| 830 | return rcu_dereference_protected(slots[offset], mt_locked(mt)); |
| 831 | } |
| 832 | /* |
| 833 | * mas_slot_locked() - Get the slot value when holding the maple tree lock. |
| 834 | * @mas: The maple state |
| 835 | * @slots: The pointer to the slots |
| 836 | * @offset: The offset into the slots array to fetch |
| 837 | * |
| 838 | * Return: The entry stored in @slots at the @offset. |
| 839 | */ |
| 840 | static inline void *mas_slot_locked(struct ma_state *mas, void __rcu **slots, |
| 841 | unsigned char offset) |
| 842 | { |
| 843 | return mt_slot_locked(mas->tree, slots, offset); |
| 844 | } |
| 845 | |
| 846 | /* |
| 847 | * mas_slot() - Get the slot value when not holding the maple tree lock. |
| 848 | * @mas: The maple state |
| 849 | * @slots: The pointer to the slots |
| 850 | * @offset: The offset into the slots array to fetch |
| 851 | * |
| 852 | * Return: The entry stored in @slots at the @offset |
| 853 | */ |
| 854 | static inline void *mas_slot(struct ma_state *mas, void __rcu **slots, |
| 855 | unsigned char offset) |
| 856 | { |
| 857 | return mt_slot(mas->tree, slots, offset); |
| 858 | } |
| 859 | |
| 860 | /* |
| 861 | * mas_root() - Get the maple tree root. |
| 862 | * @mas: The maple state. |
| 863 | * |
| 864 | * Return: The pointer to the root of the tree |
| 865 | */ |
| 866 | static inline void *mas_root(struct ma_state *mas) |
| 867 | { |
| 868 | return rcu_dereference_check(mas->tree->ma_root, mt_locked(mas->tree)); |
| 869 | } |
| 870 | |
| 871 | static inline void *mt_root_locked(struct maple_tree *mt) |
| 872 | { |
| 873 | return rcu_dereference_protected(mt->ma_root, mt_locked(mt)); |
| 874 | } |
| 875 | |
| 876 | /* |
| 877 | * mas_root_locked() - Get the maple tree root when holding the maple tree lock. |
| 878 | * @mas: The maple state. |
| 879 | * |
| 880 | * Return: The pointer to the root of the tree |
| 881 | */ |
| 882 | static inline void *mas_root_locked(struct ma_state *mas) |
| 883 | { |
| 884 | return mt_root_locked(mas->tree); |
| 885 | } |
| 886 | |
| 887 | static inline struct maple_metadata *ma_meta(struct maple_node *mn, |
| 888 | enum maple_type mt) |
| 889 | { |
| 890 | switch (mt) { |
| 891 | case maple_arange_64: |
| 892 | return &mn->ma64.meta; |
| 893 | default: |
| 894 | return &mn->mr64.meta; |
| 895 | } |
| 896 | } |
| 897 | |
| 898 | /* |
| 899 | * ma_set_meta() - Set the metadata information of a node. |
| 900 | * @mn: The maple node |
| 901 | * @mt: The maple node type |
| 902 | * @offset: The offset of the highest sub-gap in this node. |
| 903 | * @end: The end of the data in this node. |
| 904 | */ |
| 905 | static inline void ma_set_meta(struct maple_node *mn, enum maple_type mt, |
| 906 | unsigned char offset, unsigned char end) |
| 907 | { |
| 908 | struct maple_metadata *meta = ma_meta(mn, mt); |
| 909 | |
| 910 | meta->gap = offset; |
| 911 | meta->end = end; |
| 912 | } |
| 913 | |
| 914 | /* |
| 915 | * mt_clear_meta() - clear the metadata information of a node, if it exists |
| 916 | * @mt: The maple tree |
| 917 | * @mn: The maple node |
| 918 | * @type: The maple node type |
| 919 | * @offset: The offset of the highest sub-gap in this node. |
| 920 | * @end: The end of the data in this node. |
| 921 | */ |
| 922 | static inline void mt_clear_meta(struct maple_tree *mt, struct maple_node *mn, |
| 923 | enum maple_type type) |
| 924 | { |
| 925 | struct maple_metadata *meta; |
| 926 | unsigned long *pivots; |
| 927 | void __rcu **slots; |
| 928 | void *next; |
| 929 | |
| 930 | switch (type) { |
| 931 | case maple_range_64: |
| 932 | pivots = mn->mr64.pivot; |
| 933 | if (unlikely(pivots[MAPLE_RANGE64_SLOTS - 2])) { |
| 934 | slots = mn->mr64.slot; |
| 935 | next = mt_slot_locked(mt, slots, |
| 936 | MAPLE_RANGE64_SLOTS - 1); |
| 937 | if (unlikely((mte_to_node(next) && |
| 938 | mte_node_type(next)))) |
| 939 | return; /* no metadata, could be node */ |
| 940 | } |
| 941 | fallthrough; |
| 942 | case maple_arange_64: |
| 943 | meta = ma_meta(mn, type); |
| 944 | break; |
| 945 | default: |
| 946 | return; |
| 947 | } |
| 948 | |
| 949 | meta->gap = 0; |
| 950 | meta->end = 0; |
| 951 | } |
| 952 | |
| 953 | /* |
| 954 | * ma_meta_end() - Get the data end of a node from the metadata |
| 955 | * @mn: The maple node |
| 956 | * @mt: The maple node type |
| 957 | */ |
| 958 | static inline unsigned char ma_meta_end(struct maple_node *mn, |
| 959 | enum maple_type mt) |
| 960 | { |
| 961 | struct maple_metadata *meta = ma_meta(mn, mt); |
| 962 | |
| 963 | return meta->end; |
| 964 | } |
| 965 | |
| 966 | /* |
| 967 | * ma_meta_gap() - Get the largest gap location of a node from the metadata |
| 968 | * @mn: The maple node |
| 969 | * @mt: The maple node type |
| 970 | */ |
| 971 | static inline unsigned char ma_meta_gap(struct maple_node *mn, |
| 972 | enum maple_type mt) |
| 973 | { |
| 974 | BUG_ON(mt != maple_arange_64); |
| 975 | |
| 976 | return mn->ma64.meta.gap; |
| 977 | } |
| 978 | |
| 979 | /* |
| 980 | * ma_set_meta_gap() - Set the largest gap location in a nodes metadata |
| 981 | * @mn: The maple node |
| 982 | * @mn: The maple node type |
| 983 | * @offset: The location of the largest gap. |
| 984 | */ |
| 985 | static inline void ma_set_meta_gap(struct maple_node *mn, enum maple_type mt, |
| 986 | unsigned char offset) |
| 987 | { |
| 988 | |
| 989 | struct maple_metadata *meta = ma_meta(mn, mt); |
| 990 | |
| 991 | meta->gap = offset; |
| 992 | } |
| 993 | |
| 994 | /* |
| 995 | * mat_add() - Add a @dead_enode to the ma_topiary of a list of dead nodes. |
| 996 | * @mat - the ma_topiary, a linked list of dead nodes. |
| 997 | * @dead_enode - the node to be marked as dead and added to the tail of the list |
| 998 | * |
| 999 | * Add the @dead_enode to the linked list in @mat. |
| 1000 | */ |
| 1001 | static inline void mat_add(struct ma_topiary *mat, |
| 1002 | struct maple_enode *dead_enode) |
| 1003 | { |
| 1004 | mte_set_node_dead(dead_enode); |
| 1005 | mte_to_mat(dead_enode)->next = NULL; |
| 1006 | if (!mat->tail) { |
| 1007 | mat->tail = mat->head = dead_enode; |
| 1008 | return; |
| 1009 | } |
| 1010 | |
| 1011 | mte_to_mat(mat->tail)->next = dead_enode; |
| 1012 | mat->tail = dead_enode; |
| 1013 | } |
| 1014 | |
| 1015 | static void mte_destroy_walk(struct maple_enode *, struct maple_tree *); |
| 1016 | static inline void mas_free(struct ma_state *mas, struct maple_enode *used); |
| 1017 | |
| 1018 | /* |
| 1019 | * mas_mat_free() - Free all nodes in a dead list. |
| 1020 | * @mas - the maple state |
| 1021 | * @mat - the ma_topiary linked list of dead nodes to free. |
| 1022 | * |
| 1023 | * Free walk a dead list. |
| 1024 | */ |
| 1025 | static void mas_mat_free(struct ma_state *mas, struct ma_topiary *mat) |
| 1026 | { |
| 1027 | struct maple_enode *next; |
| 1028 | |
| 1029 | while (mat->head) { |
| 1030 | next = mte_to_mat(mat->head)->next; |
| 1031 | mas_free(mas, mat->head); |
| 1032 | mat->head = next; |
| 1033 | } |
| 1034 | } |
| 1035 | |
| 1036 | /* |
| 1037 | * mas_mat_destroy() - Free all nodes and subtrees in a dead list. |
| 1038 | * @mas - the maple state |
| 1039 | * @mat - the ma_topiary linked list of dead nodes to free. |
| 1040 | * |
| 1041 | * Destroy walk a dead list. |
| 1042 | */ |
| 1043 | static void mas_mat_destroy(struct ma_state *mas, struct ma_topiary *mat) |
| 1044 | { |
| 1045 | struct maple_enode *next; |
| 1046 | |
| 1047 | while (mat->head) { |
| 1048 | next = mte_to_mat(mat->head)->next; |
| 1049 | mte_destroy_walk(mat->head, mat->mtree); |
| 1050 | mat->head = next; |
| 1051 | } |
| 1052 | } |
| 1053 | /* |
| 1054 | * mas_descend() - Descend into the slot stored in the ma_state. |
| 1055 | * @mas - the maple state. |
| 1056 | * |
| 1057 | * Note: Not RCU safe, only use in write side or debug code. |
| 1058 | */ |
| 1059 | static inline void mas_descend(struct ma_state *mas) |
| 1060 | { |
| 1061 | enum maple_type type; |
| 1062 | unsigned long *pivots; |
| 1063 | struct maple_node *node; |
| 1064 | void __rcu **slots; |
| 1065 | |
| 1066 | node = mas_mn(mas); |
| 1067 | type = mte_node_type(mas->node); |
| 1068 | pivots = ma_pivots(node, type); |
| 1069 | slots = ma_slots(node, type); |
| 1070 | |
| 1071 | if (mas->offset) |
| 1072 | mas->min = pivots[mas->offset - 1] + 1; |
| 1073 | mas->max = mas_safe_pivot(mas, pivots, mas->offset, type); |
| 1074 | mas->node = mas_slot(mas, slots, mas->offset); |
| 1075 | } |
| 1076 | |
| 1077 | /* |
| 1078 | * mte_set_gap() - Set a maple node gap. |
| 1079 | * @mn: The encoded maple node |
| 1080 | * @gap: The offset of the gap to set |
| 1081 | * @val: The gap value |
| 1082 | */ |
| 1083 | static inline void mte_set_gap(const struct maple_enode *mn, |
| 1084 | unsigned char gap, unsigned long val) |
| 1085 | { |
| 1086 | switch (mte_node_type(mn)) { |
| 1087 | default: |
| 1088 | break; |
| 1089 | case maple_arange_64: |
| 1090 | mte_to_node(mn)->ma64.gap[gap] = val; |
| 1091 | break; |
| 1092 | } |
| 1093 | } |
| 1094 | |
| 1095 | /* |
| 1096 | * mas_ascend() - Walk up a level of the tree. |
| 1097 | * @mas: The maple state |
| 1098 | * |
| 1099 | * Sets the @mas->max and @mas->min to the correct values when walking up. This |
| 1100 | * may cause several levels of walking up to find the correct min and max. |
| 1101 | * May find a dead node which will cause a premature return. |
| 1102 | * Return: 1 on dead node, 0 otherwise |
| 1103 | */ |
| 1104 | static int mas_ascend(struct ma_state *mas) |
| 1105 | { |
| 1106 | struct maple_enode *p_enode; /* parent enode. */ |
| 1107 | struct maple_enode *a_enode; /* ancestor enode. */ |
| 1108 | struct maple_node *a_node; /* ancestor node. */ |
| 1109 | struct maple_node *p_node; /* parent node. */ |
| 1110 | unsigned char a_slot; |
| 1111 | enum maple_type a_type; |
| 1112 | unsigned long min, max; |
| 1113 | unsigned long *pivots; |
| 1114 | unsigned char offset; |
| 1115 | bool set_max = false, set_min = false; |
| 1116 | |
| 1117 | a_node = mas_mn(mas); |
| 1118 | if (ma_is_root(a_node)) { |
| 1119 | mas->offset = 0; |
| 1120 | return 0; |
| 1121 | } |
| 1122 | |
| 1123 | p_node = mte_parent(mas->node); |
| 1124 | if (unlikely(a_node == p_node)) |
| 1125 | return 1; |
| 1126 | a_type = mas_parent_enum(mas, mas->node); |
| 1127 | offset = mte_parent_slot(mas->node); |
| 1128 | a_enode = mt_mk_node(p_node, a_type); |
| 1129 | |
| 1130 | /* Check to make sure all parent information is still accurate */ |
| 1131 | if (p_node != mte_parent(mas->node)) |
| 1132 | return 1; |
| 1133 | |
| 1134 | mas->node = a_enode; |
| 1135 | mas->offset = offset; |
| 1136 | |
| 1137 | if (mte_is_root(a_enode)) { |
| 1138 | mas->max = ULONG_MAX; |
| 1139 | mas->min = 0; |
| 1140 | return 0; |
| 1141 | } |
| 1142 | |
| 1143 | min = 0; |
| 1144 | max = ULONG_MAX; |
| 1145 | do { |
| 1146 | p_enode = a_enode; |
| 1147 | a_type = mas_parent_enum(mas, p_enode); |
| 1148 | a_node = mte_parent(p_enode); |
| 1149 | a_slot = mte_parent_slot(p_enode); |
| 1150 | a_enode = mt_mk_node(a_node, a_type); |
| 1151 | pivots = ma_pivots(a_node, a_type); |
| 1152 | |
| 1153 | if (unlikely(ma_dead_node(a_node))) |
| 1154 | return 1; |
| 1155 | |
| 1156 | if (!set_min && a_slot) { |
| 1157 | set_min = true; |
| 1158 | min = pivots[a_slot - 1] + 1; |
| 1159 | } |
| 1160 | |
| 1161 | if (!set_max && a_slot < mt_pivots[a_type]) { |
| 1162 | set_max = true; |
| 1163 | max = pivots[a_slot]; |
| 1164 | } |
| 1165 | |
| 1166 | if (unlikely(ma_dead_node(a_node))) |
| 1167 | return 1; |
| 1168 | |
| 1169 | if (unlikely(ma_is_root(a_node))) |
| 1170 | break; |
| 1171 | |
| 1172 | } while (!set_min || !set_max); |
| 1173 | |
| 1174 | mas->max = max; |
| 1175 | mas->min = min; |
| 1176 | return 0; |
| 1177 | } |
| 1178 | |
| 1179 | /* |
| 1180 | * mas_pop_node() - Get a previously allocated maple node from the maple state. |
| 1181 | * @mas: The maple state |
| 1182 | * |
| 1183 | * Return: A pointer to a maple node. |
| 1184 | */ |
| 1185 | static inline struct maple_node *mas_pop_node(struct ma_state *mas) |
| 1186 | { |
| 1187 | struct maple_alloc *ret, *node = mas->alloc; |
| 1188 | unsigned long total = mas_allocated(mas); |
| 1189 | unsigned int req = mas_alloc_req(mas); |
| 1190 | |
| 1191 | /* nothing or a request pending. */ |
| 1192 | if (WARN_ON(!total)) |
| 1193 | return NULL; |
| 1194 | |
| 1195 | if (total == 1) { |
| 1196 | /* single allocation in this ma_state */ |
| 1197 | mas->alloc = NULL; |
| 1198 | ret = node; |
| 1199 | goto single_node; |
| 1200 | } |
| 1201 | |
| 1202 | if (node->node_count == 1) { |
| 1203 | /* Single allocation in this node. */ |
| 1204 | mas->alloc = node->slot[0]; |
| 1205 | mas->alloc->total = node->total - 1; |
| 1206 | ret = node; |
| 1207 | goto new_head; |
| 1208 | } |
| 1209 | node->total--; |
| 1210 | ret = node->slot[--node->node_count]; |
| 1211 | node->slot[node->node_count] = NULL; |
| 1212 | |
| 1213 | single_node: |
| 1214 | new_head: |
| 1215 | if (req) { |
| 1216 | req++; |
| 1217 | mas_set_alloc_req(mas, req); |
| 1218 | } |
| 1219 | |
| 1220 | memset(ret, 0, sizeof(*ret)); |
| 1221 | return (struct maple_node *)ret; |
| 1222 | } |
| 1223 | |
| 1224 | /* |
| 1225 | * mas_push_node() - Push a node back on the maple state allocation. |
| 1226 | * @mas: The maple state |
| 1227 | * @used: The used maple node |
| 1228 | * |
| 1229 | * Stores the maple node back into @mas->alloc for reuse. Updates allocated and |
| 1230 | * requested node count as necessary. |
| 1231 | */ |
| 1232 | static inline void mas_push_node(struct ma_state *mas, struct maple_node *used) |
| 1233 | { |
| 1234 | struct maple_alloc *reuse = (struct maple_alloc *)used; |
| 1235 | struct maple_alloc *head = mas->alloc; |
| 1236 | unsigned long count; |
| 1237 | unsigned int requested = mas_alloc_req(mas); |
| 1238 | |
| 1239 | count = mas_allocated(mas); |
| 1240 | |
| 1241 | reuse->request_count = 0; |
| 1242 | reuse->node_count = 0; |
| 1243 | if (count && (head->node_count < MAPLE_ALLOC_SLOTS)) { |
| 1244 | head->slot[head->node_count++] = reuse; |
| 1245 | head->total++; |
| 1246 | goto done; |
| 1247 | } |
| 1248 | |
| 1249 | reuse->total = 1; |
| 1250 | if ((head) && !((unsigned long)head & 0x1)) { |
| 1251 | reuse->slot[0] = head; |
| 1252 | reuse->node_count = 1; |
| 1253 | reuse->total += head->total; |
| 1254 | } |
| 1255 | |
| 1256 | mas->alloc = reuse; |
| 1257 | done: |
| 1258 | if (requested > 1) |
| 1259 | mas_set_alloc_req(mas, requested - 1); |
| 1260 | } |
| 1261 | |
| 1262 | /* |
| 1263 | * mas_alloc_nodes() - Allocate nodes into a maple state |
| 1264 | * @mas: The maple state |
| 1265 | * @gfp: The GFP Flags |
| 1266 | */ |
| 1267 | static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp) |
| 1268 | { |
| 1269 | struct maple_alloc *node; |
| 1270 | unsigned long allocated = mas_allocated(mas); |
| 1271 | unsigned int requested = mas_alloc_req(mas); |
| 1272 | unsigned int count; |
| 1273 | void **slots = NULL; |
| 1274 | unsigned int max_req = 0; |
| 1275 | |
| 1276 | if (!requested) |
| 1277 | return; |
| 1278 | |
| 1279 | mas_set_alloc_req(mas, 0); |
| 1280 | if (mas->mas_flags & MA_STATE_PREALLOC) { |
| 1281 | if (allocated) |
| 1282 | return; |
| 1283 | WARN_ON(!allocated); |
| 1284 | } |
| 1285 | |
| 1286 | if (!allocated || mas->alloc->node_count == MAPLE_ALLOC_SLOTS) { |
| 1287 | node = (struct maple_alloc *)mt_alloc_one(gfp); |
| 1288 | if (!node) |
| 1289 | goto nomem_one; |
| 1290 | |
| 1291 | if (allocated) { |
| 1292 | node->slot[0] = mas->alloc; |
| 1293 | node->node_count = 1; |
| 1294 | } else { |
| 1295 | node->node_count = 0; |
| 1296 | } |
| 1297 | |
| 1298 | mas->alloc = node; |
| 1299 | node->total = ++allocated; |
| 1300 | requested--; |
| 1301 | } |
| 1302 | |
| 1303 | node = mas->alloc; |
| 1304 | node->request_count = 0; |
| 1305 | while (requested) { |
| 1306 | max_req = MAPLE_ALLOC_SLOTS - node->node_count; |
| 1307 | slots = (void **)&node->slot[node->node_count]; |
| 1308 | max_req = min(requested, max_req); |
| 1309 | count = mt_alloc_bulk(gfp, max_req, slots); |
| 1310 | if (!count) |
| 1311 | goto nomem_bulk; |
| 1312 | |
| 1313 | if (node->node_count == 0) { |
| 1314 | node->slot[0]->node_count = 0; |
| 1315 | node->slot[0]->request_count = 0; |
| 1316 | } |
| 1317 | |
| 1318 | node->node_count += count; |
| 1319 | allocated += count; |
| 1320 | node = node->slot[0]; |
| 1321 | requested -= count; |
| 1322 | } |
| 1323 | mas->alloc->total = allocated; |
| 1324 | return; |
| 1325 | |
| 1326 | nomem_bulk: |
| 1327 | /* Clean up potential freed allocations on bulk failure */ |
| 1328 | memset(slots, 0, max_req * sizeof(unsigned long)); |
| 1329 | nomem_one: |
| 1330 | mas_set_alloc_req(mas, requested); |
| 1331 | if (mas->alloc && !(((unsigned long)mas->alloc & 0x1))) |
| 1332 | mas->alloc->total = allocated; |
| 1333 | mas_set_err(mas, -ENOMEM); |
| 1334 | } |
| 1335 | |
| 1336 | /* |
| 1337 | * mas_free() - Free an encoded maple node |
| 1338 | * @mas: The maple state |
| 1339 | * @used: The encoded maple node to free. |
| 1340 | * |
| 1341 | * Uses rcu free if necessary, pushes @used back on the maple state allocations |
| 1342 | * otherwise. |
| 1343 | */ |
| 1344 | static inline void mas_free(struct ma_state *mas, struct maple_enode *used) |
| 1345 | { |
| 1346 | struct maple_node *tmp = mte_to_node(used); |
| 1347 | |
| 1348 | if (mt_in_rcu(mas->tree)) |
| 1349 | ma_free_rcu(tmp); |
| 1350 | else |
| 1351 | mas_push_node(mas, tmp); |
| 1352 | } |
| 1353 | |
| 1354 | /* |
| 1355 | * mas_node_count() - Check if enough nodes are allocated and request more if |
| 1356 | * there is not enough nodes. |
| 1357 | * @mas: The maple state |
| 1358 | * @count: The number of nodes needed |
| 1359 | * @gfp: the gfp flags |
| 1360 | */ |
| 1361 | static void mas_node_count_gfp(struct ma_state *mas, int count, gfp_t gfp) |
| 1362 | { |
| 1363 | unsigned long allocated = mas_allocated(mas); |
| 1364 | |
| 1365 | if (allocated < count) { |
| 1366 | mas_set_alloc_req(mas, count - allocated); |
| 1367 | mas_alloc_nodes(mas, gfp); |
| 1368 | } |
| 1369 | } |
| 1370 | |
| 1371 | /* |
| 1372 | * mas_node_count() - Check if enough nodes are allocated and request more if |
| 1373 | * there is not enough nodes. |
| 1374 | * @mas: The maple state |
| 1375 | * @count: The number of nodes needed |
| 1376 | * |
| 1377 | * Note: Uses GFP_NOWAIT | __GFP_NOWARN for gfp flags. |
| 1378 | */ |
| 1379 | static void mas_node_count(struct ma_state *mas, int count) |
| 1380 | { |
| 1381 | return mas_node_count_gfp(mas, count, GFP_NOWAIT | __GFP_NOWARN); |
| 1382 | } |
| 1383 | |
| 1384 | /* |
| 1385 | * mas_start() - Sets up maple state for operations. |
| 1386 | * @mas: The maple state. |
| 1387 | * |
| 1388 | * If mas->node == MAS_START, then set the min, max and depth to |
| 1389 | * defaults. |
| 1390 | * |
| 1391 | * Return: |
| 1392 | * - If mas->node is an error or not MAS_START, return NULL. |
| 1393 | * - If it's an empty tree: NULL & mas->node == MAS_NONE |
| 1394 | * - If it's a single entry: The entry & mas->node == MAS_ROOT |
| 1395 | * - If it's a tree: NULL & mas->node == safe root node. |
| 1396 | */ |
| 1397 | static inline struct maple_enode *mas_start(struct ma_state *mas) |
| 1398 | { |
| 1399 | if (likely(mas_is_start(mas))) { |
| 1400 | struct maple_enode *root; |
| 1401 | |
| 1402 | mas->min = 0; |
| 1403 | mas->max = ULONG_MAX; |
| 1404 | mas->depth = 0; |
| 1405 | |
| 1406 | retry: |
| 1407 | root = mas_root(mas); |
| 1408 | /* Tree with nodes */ |
| 1409 | if (likely(xa_is_node(root))) { |
| 1410 | mas->depth = 1; |
| 1411 | mas->node = mte_safe_root(root); |
| 1412 | mas->offset = 0; |
| 1413 | if (mte_dead_node(mas->node)) |
| 1414 | goto retry; |
| 1415 | |
| 1416 | return NULL; |
| 1417 | } |
| 1418 | |
| 1419 | /* empty tree */ |
| 1420 | if (unlikely(!root)) { |
| 1421 | mas->node = MAS_NONE; |
| 1422 | mas->offset = MAPLE_NODE_SLOTS; |
| 1423 | return NULL; |
| 1424 | } |
| 1425 | |
| 1426 | /* Single entry tree */ |
| 1427 | mas->node = MAS_ROOT; |
| 1428 | mas->offset = MAPLE_NODE_SLOTS; |
| 1429 | |
| 1430 | /* Single entry tree. */ |
| 1431 | if (mas->index > 0) |
| 1432 | return NULL; |
| 1433 | |
| 1434 | return root; |
| 1435 | } |
| 1436 | |
| 1437 | return NULL; |
| 1438 | } |
| 1439 | |
| 1440 | /* |
| 1441 | * ma_data_end() - Find the end of the data in a node. |
| 1442 | * @node: The maple node |
| 1443 | * @type: The maple node type |
| 1444 | * @pivots: The array of pivots in the node |
| 1445 | * @max: The maximum value in the node |
| 1446 | * |
| 1447 | * Uses metadata to find the end of the data when possible. |
| 1448 | * Return: The zero indexed last slot with data (may be null). |
| 1449 | */ |
| 1450 | static inline unsigned char ma_data_end(struct maple_node *node, |
| 1451 | enum maple_type type, |
| 1452 | unsigned long *pivots, |
| 1453 | unsigned long max) |
| 1454 | { |
| 1455 | unsigned char offset; |
| 1456 | |
| 1457 | if (!pivots) |
| 1458 | return 0; |
| 1459 | |
| 1460 | if (type == maple_arange_64) |
| 1461 | return ma_meta_end(node, type); |
| 1462 | |
| 1463 | offset = mt_pivots[type] - 1; |
| 1464 | if (likely(!pivots[offset])) |
| 1465 | return ma_meta_end(node, type); |
| 1466 | |
| 1467 | if (likely(pivots[offset] == max)) |
| 1468 | return offset; |
| 1469 | |
| 1470 | return mt_pivots[type]; |
| 1471 | } |
| 1472 | |
| 1473 | /* |
| 1474 | * mas_data_end() - Find the end of the data (slot). |
| 1475 | * @mas: the maple state |
| 1476 | * |
| 1477 | * This method is optimized to check the metadata of a node if the node type |
| 1478 | * supports data end metadata. |
| 1479 | * |
| 1480 | * Return: The zero indexed last slot with data (may be null). |
| 1481 | */ |
| 1482 | static inline unsigned char mas_data_end(struct ma_state *mas) |
| 1483 | { |
| 1484 | enum maple_type type; |
| 1485 | struct maple_node *node; |
| 1486 | unsigned char offset; |
| 1487 | unsigned long *pivots; |
| 1488 | |
| 1489 | type = mte_node_type(mas->node); |
| 1490 | node = mas_mn(mas); |
| 1491 | if (type == maple_arange_64) |
| 1492 | return ma_meta_end(node, type); |
| 1493 | |
| 1494 | pivots = ma_pivots(node, type); |
| 1495 | if (unlikely(ma_dead_node(node))) |
| 1496 | return 0; |
| 1497 | |
| 1498 | offset = mt_pivots[type] - 1; |
| 1499 | if (likely(!pivots[offset])) |
| 1500 | return ma_meta_end(node, type); |
| 1501 | |
| 1502 | if (likely(pivots[offset] == mas->max)) |
| 1503 | return offset; |
| 1504 | |
| 1505 | return mt_pivots[type]; |
| 1506 | } |
| 1507 | |
| 1508 | /* |
| 1509 | * mas_leaf_max_gap() - Returns the largest gap in a leaf node |
| 1510 | * @mas - the maple state |
| 1511 | * |
| 1512 | * Return: The maximum gap in the leaf. |
| 1513 | */ |
| 1514 | static unsigned long mas_leaf_max_gap(struct ma_state *mas) |
| 1515 | { |
| 1516 | enum maple_type mt; |
| 1517 | unsigned long pstart, gap, max_gap; |
| 1518 | struct maple_node *mn; |
| 1519 | unsigned long *pivots; |
| 1520 | void __rcu **slots; |
| 1521 | unsigned char i; |
| 1522 | unsigned char max_piv; |
| 1523 | |
| 1524 | mt = mte_node_type(mas->node); |
| 1525 | mn = mas_mn(mas); |
| 1526 | slots = ma_slots(mn, mt); |
| 1527 | max_gap = 0; |
| 1528 | if (unlikely(ma_is_dense(mt))) { |
| 1529 | gap = 0; |
| 1530 | for (i = 0; i < mt_slots[mt]; i++) { |
| 1531 | if (slots[i]) { |
| 1532 | if (gap > max_gap) |
| 1533 | max_gap = gap; |
| 1534 | gap = 0; |
| 1535 | } else { |
| 1536 | gap++; |
| 1537 | } |
| 1538 | } |
| 1539 | if (gap > max_gap) |
| 1540 | max_gap = gap; |
| 1541 | return max_gap; |
| 1542 | } |
| 1543 | |
| 1544 | /* |
| 1545 | * Check the first implied pivot optimizes the loop below and slot 1 may |
| 1546 | * be skipped if there is a gap in slot 0. |
| 1547 | */ |
| 1548 | pivots = ma_pivots(mn, mt); |
| 1549 | if (likely(!slots[0])) { |
| 1550 | max_gap = pivots[0] - mas->min + 1; |
| 1551 | i = 2; |
| 1552 | } else { |
| 1553 | i = 1; |
| 1554 | } |
| 1555 | |
| 1556 | /* reduce max_piv as the special case is checked before the loop */ |
| 1557 | max_piv = ma_data_end(mn, mt, pivots, mas->max) - 1; |
| 1558 | /* |
| 1559 | * Check end implied pivot which can only be a gap on the right most |
| 1560 | * node. |
| 1561 | */ |
| 1562 | if (unlikely(mas->max == ULONG_MAX) && !slots[max_piv + 1]) { |
| 1563 | gap = ULONG_MAX - pivots[max_piv]; |
| 1564 | if (gap > max_gap) |
| 1565 | max_gap = gap; |
| 1566 | } |
| 1567 | |
| 1568 | for (; i <= max_piv; i++) { |
| 1569 | /* data == no gap. */ |
| 1570 | if (likely(slots[i])) |
| 1571 | continue; |
| 1572 | |
| 1573 | pstart = pivots[i - 1]; |
| 1574 | gap = pivots[i] - pstart; |
| 1575 | if (gap > max_gap) |
| 1576 | max_gap = gap; |
| 1577 | |
| 1578 | /* There cannot be two gaps in a row. */ |
| 1579 | i++; |
| 1580 | } |
| 1581 | return max_gap; |
| 1582 | } |
| 1583 | |
| 1584 | /* |
| 1585 | * ma_max_gap() - Get the maximum gap in a maple node (non-leaf) |
| 1586 | * @node: The maple node |
| 1587 | * @gaps: The pointer to the gaps |
| 1588 | * @mt: The maple node type |
| 1589 | * @*off: Pointer to store the offset location of the gap. |
| 1590 | * |
| 1591 | * Uses the metadata data end to scan backwards across set gaps. |
| 1592 | * |
| 1593 | * Return: The maximum gap value |
| 1594 | */ |
| 1595 | static inline unsigned long |
| 1596 | ma_max_gap(struct maple_node *node, unsigned long *gaps, enum maple_type mt, |
| 1597 | unsigned char *off) |
| 1598 | { |
| 1599 | unsigned char offset, i; |
| 1600 | unsigned long max_gap = 0; |
| 1601 | |
| 1602 | i = offset = ma_meta_end(node, mt); |
| 1603 | do { |
| 1604 | if (gaps[i] > max_gap) { |
| 1605 | max_gap = gaps[i]; |
| 1606 | offset = i; |
| 1607 | } |
| 1608 | } while (i--); |
| 1609 | |
| 1610 | *off = offset; |
| 1611 | return max_gap; |
| 1612 | } |
| 1613 | |
| 1614 | /* |
| 1615 | * mas_max_gap() - find the largest gap in a non-leaf node and set the slot. |
| 1616 | * @mas: The maple state. |
| 1617 | * |
| 1618 | * If the metadata gap is set to MAPLE_ARANGE64_META_MAX, there is no gap. |
| 1619 | * |
| 1620 | * Return: The gap value. |
| 1621 | */ |
| 1622 | static inline unsigned long mas_max_gap(struct ma_state *mas) |
| 1623 | { |
| 1624 | unsigned long *gaps; |
| 1625 | unsigned char offset; |
| 1626 | enum maple_type mt; |
| 1627 | struct maple_node *node; |
| 1628 | |
| 1629 | mt = mte_node_type(mas->node); |
| 1630 | if (ma_is_leaf(mt)) |
| 1631 | return mas_leaf_max_gap(mas); |
| 1632 | |
| 1633 | node = mas_mn(mas); |
| 1634 | offset = ma_meta_gap(node, mt); |
| 1635 | if (offset == MAPLE_ARANGE64_META_MAX) |
| 1636 | return 0; |
| 1637 | |
| 1638 | gaps = ma_gaps(node, mt); |
| 1639 | return gaps[offset]; |
| 1640 | } |
| 1641 | |
| 1642 | /* |
| 1643 | * mas_parent_gap() - Set the parent gap and any gaps above, as needed |
| 1644 | * @mas: The maple state |
| 1645 | * @offset: The gap offset in the parent to set |
| 1646 | * @new: The new gap value. |
| 1647 | * |
| 1648 | * Set the parent gap then continue to set the gap upwards, using the metadata |
| 1649 | * of the parent to see if it is necessary to check the node above. |
| 1650 | */ |
| 1651 | static inline void mas_parent_gap(struct ma_state *mas, unsigned char offset, |
| 1652 | unsigned long new) |
| 1653 | { |
| 1654 | unsigned long meta_gap = 0; |
| 1655 | struct maple_node *pnode; |
| 1656 | struct maple_enode *penode; |
| 1657 | unsigned long *pgaps; |
| 1658 | unsigned char meta_offset; |
| 1659 | enum maple_type pmt; |
| 1660 | |
| 1661 | pnode = mte_parent(mas->node); |
| 1662 | pmt = mas_parent_enum(mas, mas->node); |
| 1663 | penode = mt_mk_node(pnode, pmt); |
| 1664 | pgaps = ma_gaps(pnode, pmt); |
| 1665 | |
| 1666 | ascend: |
| 1667 | meta_offset = ma_meta_gap(pnode, pmt); |
| 1668 | if (meta_offset == MAPLE_ARANGE64_META_MAX) |
| 1669 | meta_gap = 0; |
| 1670 | else |
| 1671 | meta_gap = pgaps[meta_offset]; |
| 1672 | |
| 1673 | pgaps[offset] = new; |
| 1674 | |
| 1675 | if (meta_gap == new) |
| 1676 | return; |
| 1677 | |
| 1678 | if (offset != meta_offset) { |
| 1679 | if (meta_gap > new) |
| 1680 | return; |
| 1681 | |
| 1682 | ma_set_meta_gap(pnode, pmt, offset); |
| 1683 | } else if (new < meta_gap) { |
| 1684 | meta_offset = 15; |
| 1685 | new = ma_max_gap(pnode, pgaps, pmt, &meta_offset); |
| 1686 | ma_set_meta_gap(pnode, pmt, meta_offset); |
| 1687 | } |
| 1688 | |
| 1689 | if (ma_is_root(pnode)) |
| 1690 | return; |
| 1691 | |
| 1692 | /* Go to the parent node. */ |
| 1693 | pnode = mte_parent(penode); |
| 1694 | pmt = mas_parent_enum(mas, penode); |
| 1695 | pgaps = ma_gaps(pnode, pmt); |
| 1696 | offset = mte_parent_slot(penode); |
| 1697 | penode = mt_mk_node(pnode, pmt); |
| 1698 | goto ascend; |
| 1699 | } |
| 1700 | |
| 1701 | /* |
| 1702 | * mas_update_gap() - Update a nodes gaps and propagate up if necessary. |
| 1703 | * @mas - the maple state. |
| 1704 | */ |
| 1705 | static inline void mas_update_gap(struct ma_state *mas) |
| 1706 | { |
| 1707 | unsigned char pslot; |
| 1708 | unsigned long p_gap; |
| 1709 | unsigned long max_gap; |
| 1710 | |
| 1711 | if (!mt_is_alloc(mas->tree)) |
| 1712 | return; |
| 1713 | |
| 1714 | if (mte_is_root(mas->node)) |
| 1715 | return; |
| 1716 | |
| 1717 | max_gap = mas_max_gap(mas); |
| 1718 | |
| 1719 | pslot = mte_parent_slot(mas->node); |
| 1720 | p_gap = ma_gaps(mte_parent(mas->node), |
| 1721 | mas_parent_enum(mas, mas->node))[pslot]; |
| 1722 | |
| 1723 | if (p_gap != max_gap) |
| 1724 | mas_parent_gap(mas, pslot, max_gap); |
| 1725 | } |
| 1726 | |
| 1727 | /* |
| 1728 | * mas_adopt_children() - Set the parent pointer of all nodes in @parent to |
| 1729 | * @parent with the slot encoded. |
| 1730 | * @mas - the maple state (for the tree) |
| 1731 | * @parent - the maple encoded node containing the children. |
| 1732 | */ |
| 1733 | static inline void mas_adopt_children(struct ma_state *mas, |
| 1734 | struct maple_enode *parent) |
| 1735 | { |
| 1736 | enum maple_type type = mte_node_type(parent); |
| 1737 | struct maple_node *node = mas_mn(mas); |
| 1738 | void __rcu **slots = ma_slots(node, type); |
| 1739 | unsigned long *pivots = ma_pivots(node, type); |
| 1740 | struct maple_enode *child; |
| 1741 | unsigned char offset; |
| 1742 | |
| 1743 | offset = ma_data_end(node, type, pivots, mas->max); |
| 1744 | do { |
| 1745 | child = mas_slot_locked(mas, slots, offset); |
| 1746 | mte_set_parent(child, parent, offset); |
| 1747 | } while (offset--); |
| 1748 | } |
| 1749 | |
| 1750 | /* |
| 1751 | * mas_replace() - Replace a maple node in the tree with mas->node. Uses the |
| 1752 | * parent encoding to locate the maple node in the tree. |
| 1753 | * @mas - the ma_state to use for operations. |
| 1754 | * @advanced - boolean to adopt the child nodes and free the old node (false) or |
| 1755 | * leave the node (true) and handle the adoption and free elsewhere. |
| 1756 | */ |
| 1757 | static inline void mas_replace(struct ma_state *mas, bool advanced) |
| 1758 | __must_hold(mas->tree->lock) |
| 1759 | { |
| 1760 | struct maple_node *mn = mas_mn(mas); |
| 1761 | struct maple_enode *old_enode; |
| 1762 | unsigned char offset = 0; |
| 1763 | void __rcu **slots = NULL; |
| 1764 | |
| 1765 | if (ma_is_root(mn)) { |
| 1766 | old_enode = mas_root_locked(mas); |
| 1767 | } else { |
| 1768 | offset = mte_parent_slot(mas->node); |
| 1769 | slots = ma_slots(mte_parent(mas->node), |
| 1770 | mas_parent_enum(mas, mas->node)); |
| 1771 | old_enode = mas_slot_locked(mas, slots, offset); |
| 1772 | } |
| 1773 | |
| 1774 | if (!advanced && !mte_is_leaf(mas->node)) |
| 1775 | mas_adopt_children(mas, mas->node); |
| 1776 | |
| 1777 | if (mte_is_root(mas->node)) { |
| 1778 | mn->parent = ma_parent_ptr( |
| 1779 | ((unsigned long)mas->tree | MA_ROOT_PARENT)); |
| 1780 | rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node)); |
| 1781 | mas_set_height(mas); |
| 1782 | } else { |
| 1783 | rcu_assign_pointer(slots[offset], mas->node); |
| 1784 | } |
| 1785 | |
| 1786 | if (!advanced) { |
| 1787 | mte_set_node_dead(old_enode); |
| 1788 | mas_free(mas, old_enode); |
| 1789 | } |
| 1790 | } |
| 1791 | |
| 1792 | /* |
| 1793 | * mas_new_child() - Find the new child of a node. |
| 1794 | * @mas: the maple state |
| 1795 | * @child: the maple state to store the child. |
| 1796 | */ |
| 1797 | static inline bool mas_new_child(struct ma_state *mas, struct ma_state *child) |
| 1798 | __must_hold(mas->tree->lock) |
| 1799 | { |
| 1800 | enum maple_type mt; |
| 1801 | unsigned char offset; |
| 1802 | unsigned char end; |
| 1803 | unsigned long *pivots; |
| 1804 | struct maple_enode *entry; |
| 1805 | struct maple_node *node; |
| 1806 | void __rcu **slots; |
| 1807 | |
| 1808 | mt = mte_node_type(mas->node); |
| 1809 | node = mas_mn(mas); |
| 1810 | slots = ma_slots(node, mt); |
| 1811 | pivots = ma_pivots(node, mt); |
| 1812 | end = ma_data_end(node, mt, pivots, mas->max); |
| 1813 | for (offset = mas->offset; offset <= end; offset++) { |
| 1814 | entry = mas_slot_locked(mas, slots, offset); |
| 1815 | if (mte_parent(entry) == node) { |
| 1816 | *child = *mas; |
| 1817 | mas->offset = offset + 1; |
| 1818 | child->offset = offset; |
| 1819 | mas_descend(child); |
| 1820 | child->offset = 0; |
| 1821 | return true; |
| 1822 | } |
| 1823 | } |
| 1824 | return false; |
| 1825 | } |
| 1826 | |
| 1827 | /* |
| 1828 | * mab_shift_right() - Shift the data in mab right. Note, does not clean out the |
| 1829 | * old data or set b_node->b_end. |
| 1830 | * @b_node: the maple_big_node |
| 1831 | * @shift: the shift count |
| 1832 | */ |
| 1833 | static inline void mab_shift_right(struct maple_big_node *b_node, |
| 1834 | unsigned char shift) |
| 1835 | { |
| 1836 | unsigned long size = b_node->b_end * sizeof(unsigned long); |
| 1837 | |
| 1838 | memmove(b_node->pivot + shift, b_node->pivot, size); |
| 1839 | memmove(b_node->slot + shift, b_node->slot, size); |
| 1840 | if (b_node->type == maple_arange_64) |
| 1841 | memmove(b_node->gap + shift, b_node->gap, size); |
| 1842 | } |
| 1843 | |
| 1844 | /* |
| 1845 | * mab_middle_node() - Check if a middle node is needed (unlikely) |
| 1846 | * @b_node: the maple_big_node that contains the data. |
| 1847 | * @size: the amount of data in the b_node |
| 1848 | * @split: the potential split location |
| 1849 | * @slot_count: the size that can be stored in a single node being considered. |
| 1850 | * |
| 1851 | * Return: true if a middle node is required. |
| 1852 | */ |
| 1853 | static inline bool mab_middle_node(struct maple_big_node *b_node, int split, |
| 1854 | unsigned char slot_count) |
| 1855 | { |
| 1856 | unsigned char size = b_node->b_end; |
| 1857 | |
| 1858 | if (size >= 2 * slot_count) |
| 1859 | return true; |
| 1860 | |
| 1861 | if (!b_node->slot[split] && (size >= 2 * slot_count - 1)) |
| 1862 | return true; |
| 1863 | |
| 1864 | return false; |
| 1865 | } |
| 1866 | |
| 1867 | /* |
| 1868 | * mab_no_null_split() - ensure the split doesn't fall on a NULL |
| 1869 | * @b_node: the maple_big_node with the data |
| 1870 | * @split: the suggested split location |
| 1871 | * @slot_count: the number of slots in the node being considered. |
| 1872 | * |
| 1873 | * Return: the split location. |
| 1874 | */ |
| 1875 | static inline int mab_no_null_split(struct maple_big_node *b_node, |
| 1876 | unsigned char split, unsigned char slot_count) |
| 1877 | { |
| 1878 | if (!b_node->slot[split]) { |
| 1879 | /* |
| 1880 | * If the split is less than the max slot && the right side will |
| 1881 | * still be sufficient, then increment the split on NULL. |
| 1882 | */ |
| 1883 | if ((split < slot_count - 1) && |
| 1884 | (b_node->b_end - split) > (mt_min_slots[b_node->type])) |
| 1885 | split++; |
| 1886 | else |
| 1887 | split--; |
| 1888 | } |
| 1889 | return split; |
| 1890 | } |
| 1891 | |
| 1892 | /* |
| 1893 | * mab_calc_split() - Calculate the split location and if there needs to be two |
| 1894 | * splits. |
| 1895 | * @bn: The maple_big_node with the data |
| 1896 | * @mid_split: The second split, if required. 0 otherwise. |
| 1897 | * |
| 1898 | * Return: The first split location. The middle split is set in @mid_split. |
| 1899 | */ |
| 1900 | static inline int mab_calc_split(struct ma_state *mas, |
| 1901 | struct maple_big_node *bn, unsigned char *mid_split, unsigned long min) |
| 1902 | { |
| 1903 | unsigned char b_end = bn->b_end; |
| 1904 | int split = b_end / 2; /* Assume equal split. */ |
| 1905 | unsigned char slot_min, slot_count = mt_slots[bn->type]; |
| 1906 | |
| 1907 | /* |
| 1908 | * To support gap tracking, all NULL entries are kept together and a node cannot |
| 1909 | * end on a NULL entry, with the exception of the left-most leaf. The |
| 1910 | * limitation means that the split of a node must be checked for this condition |
| 1911 | * and be able to put more data in one direction or the other. |
| 1912 | */ |
| 1913 | if (unlikely((mas->mas_flags & MA_STATE_BULK))) { |
| 1914 | *mid_split = 0; |
| 1915 | split = b_end - mt_min_slots[bn->type]; |
| 1916 | |
| 1917 | if (!ma_is_leaf(bn->type)) |
| 1918 | return split; |
| 1919 | |
| 1920 | mas->mas_flags |= MA_STATE_REBALANCE; |
| 1921 | if (!bn->slot[split]) |
| 1922 | split--; |
| 1923 | return split; |
| 1924 | } |
| 1925 | |
| 1926 | /* |
| 1927 | * Although extremely rare, it is possible to enter what is known as the 3-way |
| 1928 | * split scenario. The 3-way split comes about by means of a store of a range |
| 1929 | * that overwrites the end and beginning of two full nodes. The result is a set |
| 1930 | * of entries that cannot be stored in 2 nodes. Sometimes, these two nodes can |
| 1931 | * also be located in different parent nodes which are also full. This can |
| 1932 | * carry upwards all the way to the root in the worst case. |
| 1933 | */ |
| 1934 | if (unlikely(mab_middle_node(bn, split, slot_count))) { |
| 1935 | split = b_end / 3; |
| 1936 | *mid_split = split * 2; |
| 1937 | } else { |
| 1938 | slot_min = mt_min_slots[bn->type]; |
| 1939 | |
| 1940 | *mid_split = 0; |
| 1941 | /* |
| 1942 | * Avoid having a range less than the slot count unless it |
| 1943 | * causes one node to be deficient. |
| 1944 | * NOTE: mt_min_slots is 1 based, b_end and split are zero. |
| 1945 | */ |
| 1946 | while (((bn->pivot[split] - min) < slot_count - 1) && |
| 1947 | (split < slot_count - 1) && (b_end - split > slot_min)) |
| 1948 | split++; |
| 1949 | } |
| 1950 | |
| 1951 | /* Avoid ending a node on a NULL entry */ |
| 1952 | split = mab_no_null_split(bn, split, slot_count); |
| 1953 | |
| 1954 | if (unlikely(*mid_split)) |
| 1955 | *mid_split = mab_no_null_split(bn, *mid_split, slot_count); |
| 1956 | |
| 1957 | return split; |
| 1958 | } |
| 1959 | |
| 1960 | /* |
| 1961 | * mas_mab_cp() - Copy data from a maple state inclusively to a maple_big_node |
| 1962 | * and set @b_node->b_end to the next free slot. |
| 1963 | * @mas: The maple state |
| 1964 | * @mas_start: The starting slot to copy |
| 1965 | * @mas_end: The end slot to copy (inclusively) |
| 1966 | * @b_node: The maple_big_node to place the data |
| 1967 | * @mab_start: The starting location in maple_big_node to store the data. |
| 1968 | */ |
| 1969 | static inline void mas_mab_cp(struct ma_state *mas, unsigned char mas_start, |
| 1970 | unsigned char mas_end, struct maple_big_node *b_node, |
| 1971 | unsigned char mab_start) |
| 1972 | { |
| 1973 | enum maple_type mt; |
| 1974 | struct maple_node *node; |
| 1975 | void __rcu **slots; |
| 1976 | unsigned long *pivots, *gaps; |
| 1977 | int i = mas_start, j = mab_start; |
| 1978 | unsigned char piv_end; |
| 1979 | |
| 1980 | node = mas_mn(mas); |
| 1981 | mt = mte_node_type(mas->node); |
| 1982 | pivots = ma_pivots(node, mt); |
| 1983 | if (!i) { |
| 1984 | b_node->pivot[j] = pivots[i++]; |
| 1985 | if (unlikely(i > mas_end)) |
| 1986 | goto complete; |
| 1987 | j++; |
| 1988 | } |
| 1989 | |
| 1990 | piv_end = min(mas_end, mt_pivots[mt]); |
| 1991 | for (; i < piv_end; i++, j++) { |
| 1992 | b_node->pivot[j] = pivots[i]; |
| 1993 | if (unlikely(!b_node->pivot[j])) |
| 1994 | break; |
| 1995 | |
| 1996 | if (unlikely(mas->max == b_node->pivot[j])) |
| 1997 | goto complete; |
| 1998 | } |
| 1999 | |
| 2000 | if (likely(i <= mas_end)) |
| 2001 | b_node->pivot[j] = mas_safe_pivot(mas, pivots, i, mt); |
| 2002 | |
| 2003 | complete: |
| 2004 | b_node->b_end = ++j; |
| 2005 | j -= mab_start; |
| 2006 | slots = ma_slots(node, mt); |
| 2007 | memcpy(b_node->slot + mab_start, slots + mas_start, sizeof(void *) * j); |
| 2008 | if (!ma_is_leaf(mt) && mt_is_alloc(mas->tree)) { |
| 2009 | gaps = ma_gaps(node, mt); |
| 2010 | memcpy(b_node->gap + mab_start, gaps + mas_start, |
| 2011 | sizeof(unsigned long) * j); |
| 2012 | } |
| 2013 | } |
| 2014 | |
| 2015 | /* |
| 2016 | * mas_leaf_set_meta() - Set the metadata of a leaf if possible. |
| 2017 | * @mas: The maple state |
| 2018 | * @node: The maple node |
| 2019 | * @pivots: pointer to the maple node pivots |
| 2020 | * @mt: The maple type |
| 2021 | * @end: The assumed end |
| 2022 | * |
| 2023 | * Note, end may be incremented within this function but not modified at the |
| 2024 | * source. This is fine since the metadata is the last thing to be stored in a |
| 2025 | * node during a write. |
| 2026 | */ |
| 2027 | static inline void mas_leaf_set_meta(struct ma_state *mas, |
| 2028 | struct maple_node *node, unsigned long *pivots, |
| 2029 | enum maple_type mt, unsigned char end) |
| 2030 | { |
| 2031 | /* There is no room for metadata already */ |
| 2032 | if (mt_pivots[mt] <= end) |
| 2033 | return; |
| 2034 | |
| 2035 | if (pivots[end] && pivots[end] < mas->max) |
| 2036 | end++; |
| 2037 | |
| 2038 | if (end < mt_slots[mt] - 1) |
| 2039 | ma_set_meta(node, mt, 0, end); |
| 2040 | } |
| 2041 | |
| 2042 | /* |
| 2043 | * mab_mas_cp() - Copy data from maple_big_node to a maple encoded node. |
| 2044 | * @b_node: the maple_big_node that has the data |
| 2045 | * @mab_start: the start location in @b_node. |
| 2046 | * @mab_end: The end location in @b_node (inclusively) |
| 2047 | * @mas: The maple state with the maple encoded node. |
| 2048 | */ |
| 2049 | static inline void mab_mas_cp(struct maple_big_node *b_node, |
| 2050 | unsigned char mab_start, unsigned char mab_end, |
| 2051 | struct ma_state *mas, bool new_max) |
| 2052 | { |
| 2053 | int i, j = 0; |
| 2054 | enum maple_type mt = mte_node_type(mas->node); |
| 2055 | struct maple_node *node = mte_to_node(mas->node); |
| 2056 | void __rcu **slots = ma_slots(node, mt); |
| 2057 | unsigned long *pivots = ma_pivots(node, mt); |
| 2058 | unsigned long *gaps = NULL; |
| 2059 | unsigned char end; |
| 2060 | |
| 2061 | if (mab_end - mab_start > mt_pivots[mt]) |
| 2062 | mab_end--; |
| 2063 | |
| 2064 | if (!pivots[mt_pivots[mt] - 1]) |
| 2065 | slots[mt_pivots[mt]] = NULL; |
| 2066 | |
| 2067 | i = mab_start; |
| 2068 | do { |
| 2069 | pivots[j++] = b_node->pivot[i++]; |
| 2070 | } while (i <= mab_end && likely(b_node->pivot[i])); |
| 2071 | |
| 2072 | memcpy(slots, b_node->slot + mab_start, |
| 2073 | sizeof(void *) * (i - mab_start)); |
| 2074 | |
| 2075 | if (new_max) |
| 2076 | mas->max = b_node->pivot[i - 1]; |
| 2077 | |
| 2078 | end = j - 1; |
| 2079 | if (likely(!ma_is_leaf(mt) && mt_is_alloc(mas->tree))) { |
| 2080 | unsigned long max_gap = 0; |
| 2081 | unsigned char offset = 15; |
| 2082 | |
| 2083 | gaps = ma_gaps(node, mt); |
| 2084 | do { |
| 2085 | gaps[--j] = b_node->gap[--i]; |
| 2086 | if (gaps[j] > max_gap) { |
| 2087 | offset = j; |
| 2088 | max_gap = gaps[j]; |
| 2089 | } |
| 2090 | } while (j); |
| 2091 | |
| 2092 | ma_set_meta(node, mt, offset, end); |
| 2093 | } else { |
| 2094 | mas_leaf_set_meta(mas, node, pivots, mt, end); |
| 2095 | } |
| 2096 | } |
| 2097 | |
| 2098 | /* |
| 2099 | * mas_descend_adopt() - Descend through a sub-tree and adopt children. |
| 2100 | * @mas: the maple state with the maple encoded node of the sub-tree. |
| 2101 | * |
| 2102 | * Descend through a sub-tree and adopt children who do not have the correct |
| 2103 | * parents set. Follow the parents which have the correct parents as they are |
| 2104 | * the new entries which need to be followed to find other incorrectly set |
| 2105 | * parents. |
| 2106 | */ |
| 2107 | static inline void mas_descend_adopt(struct ma_state *mas) |
| 2108 | { |
| 2109 | struct ma_state list[3], next[3]; |
| 2110 | int i, n; |
| 2111 | |
| 2112 | /* |
| 2113 | * At each level there may be up to 3 correct parent pointers which indicates |
| 2114 | * the new nodes which need to be walked to find any new nodes at a lower level. |
| 2115 | */ |
| 2116 | |
| 2117 | for (i = 0; i < 3; i++) { |
| 2118 | list[i] = *mas; |
| 2119 | list[i].offset = 0; |
| 2120 | next[i].offset = 0; |
| 2121 | } |
| 2122 | next[0] = *mas; |
| 2123 | |
| 2124 | while (!mte_is_leaf(list[0].node)) { |
| 2125 | n = 0; |
| 2126 | for (i = 0; i < 3; i++) { |
| 2127 | if (mas_is_none(&list[i])) |
| 2128 | continue; |
| 2129 | |
| 2130 | if (i && list[i-1].node == list[i].node) |
| 2131 | continue; |
| 2132 | |
| 2133 | while ((n < 3) && (mas_new_child(&list[i], &next[n]))) |
| 2134 | n++; |
| 2135 | |
| 2136 | mas_adopt_children(&list[i], list[i].node); |
| 2137 | } |
| 2138 | |
| 2139 | while (n < 3) |
| 2140 | next[n++].node = MAS_NONE; |
| 2141 | |
| 2142 | /* descend by setting the list to the children */ |
| 2143 | for (i = 0; i < 3; i++) |
| 2144 | list[i] = next[i]; |
| 2145 | } |
| 2146 | } |
| 2147 | |
| 2148 | /* |
| 2149 | * mas_bulk_rebalance() - Rebalance the end of a tree after a bulk insert. |
| 2150 | * @mas: The maple state |
| 2151 | * @end: The maple node end |
| 2152 | * @mt: The maple node type |
| 2153 | */ |
| 2154 | static inline void mas_bulk_rebalance(struct ma_state *mas, unsigned char end, |
| 2155 | enum maple_type mt) |
| 2156 | { |
| 2157 | if (!(mas->mas_flags & MA_STATE_BULK)) |
| 2158 | return; |
| 2159 | |
| 2160 | if (mte_is_root(mas->node)) |
| 2161 | return; |
| 2162 | |
| 2163 | if (end > mt_min_slots[mt]) { |
| 2164 | mas->mas_flags &= ~MA_STATE_REBALANCE; |
| 2165 | return; |
| 2166 | } |
| 2167 | } |
| 2168 | |
| 2169 | /* |
| 2170 | * mas_store_b_node() - Store an @entry into the b_node while also copying the |
| 2171 | * data from a maple encoded node. |
| 2172 | * @wr_mas: the maple write state |
| 2173 | * @b_node: the maple_big_node to fill with data |
| 2174 | * @offset_end: the offset to end copying |
| 2175 | * |
| 2176 | * Return: The actual end of the data stored in @b_node |
| 2177 | */ |
| 2178 | static noinline_for_kasan void mas_store_b_node(struct ma_wr_state *wr_mas, |
| 2179 | struct maple_big_node *b_node, unsigned char offset_end) |
| 2180 | { |
| 2181 | unsigned char slot; |
| 2182 | unsigned char b_end; |
| 2183 | /* Possible underflow of piv will wrap back to 0 before use. */ |
| 2184 | unsigned long piv; |
| 2185 | struct ma_state *mas = wr_mas->mas; |
| 2186 | |
| 2187 | b_node->type = wr_mas->type; |
| 2188 | b_end = 0; |
| 2189 | slot = mas->offset; |
| 2190 | if (slot) { |
| 2191 | /* Copy start data up to insert. */ |
| 2192 | mas_mab_cp(mas, 0, slot - 1, b_node, 0); |
| 2193 | b_end = b_node->b_end; |
| 2194 | piv = b_node->pivot[b_end - 1]; |
| 2195 | } else |
| 2196 | piv = mas->min - 1; |
| 2197 | |
| 2198 | if (piv + 1 < mas->index) { |
| 2199 | /* Handle range starting after old range */ |
| 2200 | b_node->slot[b_end] = wr_mas->content; |
| 2201 | if (!wr_mas->content) |
| 2202 | b_node->gap[b_end] = mas->index - 1 - piv; |
| 2203 | b_node->pivot[b_end++] = mas->index - 1; |
| 2204 | } |
| 2205 | |
| 2206 | /* Store the new entry. */ |
| 2207 | mas->offset = b_end; |
| 2208 | b_node->slot[b_end] = wr_mas->entry; |
| 2209 | b_node->pivot[b_end] = mas->last; |
| 2210 | |
| 2211 | /* Appended. */ |
| 2212 | if (mas->last >= mas->max) |
| 2213 | goto b_end; |
| 2214 | |
| 2215 | /* Handle new range ending before old range ends */ |
| 2216 | piv = mas_logical_pivot(mas, wr_mas->pivots, offset_end, wr_mas->type); |
| 2217 | if (piv > mas->last) { |
| 2218 | if (piv == ULONG_MAX) |
| 2219 | mas_bulk_rebalance(mas, b_node->b_end, wr_mas->type); |
| 2220 | |
| 2221 | if (offset_end != slot) |
| 2222 | wr_mas->content = mas_slot_locked(mas, wr_mas->slots, |
| 2223 | offset_end); |
| 2224 | |
| 2225 | b_node->slot[++b_end] = wr_mas->content; |
| 2226 | if (!wr_mas->content) |
| 2227 | b_node->gap[b_end] = piv - mas->last + 1; |
| 2228 | b_node->pivot[b_end] = piv; |
| 2229 | } |
| 2230 | |
| 2231 | slot = offset_end + 1; |
| 2232 | if (slot > wr_mas->node_end) |
| 2233 | goto b_end; |
| 2234 | |
| 2235 | /* Copy end data to the end of the node. */ |
| 2236 | mas_mab_cp(mas, slot, wr_mas->node_end + 1, b_node, ++b_end); |
| 2237 | b_node->b_end--; |
| 2238 | return; |
| 2239 | |
| 2240 | b_end: |
| 2241 | b_node->b_end = b_end; |
| 2242 | } |
| 2243 | |
| 2244 | /* |
| 2245 | * mas_prev_sibling() - Find the previous node with the same parent. |
| 2246 | * @mas: the maple state |
| 2247 | * |
| 2248 | * Return: True if there is a previous sibling, false otherwise. |
| 2249 | */ |
| 2250 | static inline bool mas_prev_sibling(struct ma_state *mas) |
| 2251 | { |
| 2252 | unsigned int p_slot = mte_parent_slot(mas->node); |
| 2253 | |
| 2254 | if (mte_is_root(mas->node)) |
| 2255 | return false; |
| 2256 | |
| 2257 | if (!p_slot) |
| 2258 | return false; |
| 2259 | |
| 2260 | mas_ascend(mas); |
| 2261 | mas->offset = p_slot - 1; |
| 2262 | mas_descend(mas); |
| 2263 | return true; |
| 2264 | } |
| 2265 | |
| 2266 | /* |
| 2267 | * mas_next_sibling() - Find the next node with the same parent. |
| 2268 | * @mas: the maple state |
| 2269 | * |
| 2270 | * Return: true if there is a next sibling, false otherwise. |
| 2271 | */ |
| 2272 | static inline bool mas_next_sibling(struct ma_state *mas) |
| 2273 | { |
| 2274 | MA_STATE(parent, mas->tree, mas->index, mas->last); |
| 2275 | |
| 2276 | if (mte_is_root(mas->node)) |
| 2277 | return false; |
| 2278 | |
| 2279 | parent = *mas; |
| 2280 | mas_ascend(&parent); |
| 2281 | parent.offset = mte_parent_slot(mas->node) + 1; |
| 2282 | if (parent.offset > mas_data_end(&parent)) |
| 2283 | return false; |
| 2284 | |
| 2285 | *mas = parent; |
| 2286 | mas_descend(mas); |
| 2287 | return true; |
| 2288 | } |
| 2289 | |
| 2290 | /* |
| 2291 | * mte_node_or_node() - Return the encoded node or MAS_NONE. |
| 2292 | * @enode: The encoded maple node. |
| 2293 | * |
| 2294 | * Shorthand to avoid setting %NULLs in the tree or maple_subtree_state. |
| 2295 | * |
| 2296 | * Return: @enode or MAS_NONE |
| 2297 | */ |
| 2298 | static inline struct maple_enode *mte_node_or_none(struct maple_enode *enode) |
| 2299 | { |
| 2300 | if (enode) |
| 2301 | return enode; |
| 2302 | |
| 2303 | return ma_enode_ptr(MAS_NONE); |
| 2304 | } |
| 2305 | |
| 2306 | /* |
| 2307 | * mas_wr_node_walk() - Find the correct offset for the index in the @mas. |
| 2308 | * @wr_mas: The maple write state |
| 2309 | * |
| 2310 | * Uses mas_slot_locked() and does not need to worry about dead nodes. |
| 2311 | */ |
| 2312 | static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas) |
| 2313 | { |
| 2314 | struct ma_state *mas = wr_mas->mas; |
| 2315 | unsigned char count; |
| 2316 | unsigned char offset; |
| 2317 | unsigned long index, min, max; |
| 2318 | |
| 2319 | if (unlikely(ma_is_dense(wr_mas->type))) { |
| 2320 | wr_mas->r_max = wr_mas->r_min = mas->index; |
| 2321 | mas->offset = mas->index = mas->min; |
| 2322 | return; |
| 2323 | } |
| 2324 | |
| 2325 | wr_mas->node = mas_mn(wr_mas->mas); |
| 2326 | wr_mas->pivots = ma_pivots(wr_mas->node, wr_mas->type); |
| 2327 | count = wr_mas->node_end = ma_data_end(wr_mas->node, wr_mas->type, |
| 2328 | wr_mas->pivots, mas->max); |
| 2329 | offset = mas->offset; |
| 2330 | min = mas_safe_min(mas, wr_mas->pivots, offset); |
| 2331 | if (unlikely(offset == count)) |
| 2332 | goto max; |
| 2333 | |
| 2334 | max = wr_mas->pivots[offset]; |
| 2335 | index = mas->index; |
| 2336 | if (unlikely(index <= max)) |
| 2337 | goto done; |
| 2338 | |
| 2339 | if (unlikely(!max && offset)) |
| 2340 | goto max; |
| 2341 | |
| 2342 | min = max + 1; |
| 2343 | while (++offset < count) { |
| 2344 | max = wr_mas->pivots[offset]; |
| 2345 | if (index <= max) |
| 2346 | goto done; |
| 2347 | else if (unlikely(!max)) |
| 2348 | break; |
| 2349 | |
| 2350 | min = max + 1; |
| 2351 | } |
| 2352 | |
| 2353 | max: |
| 2354 | max = mas->max; |
| 2355 | done: |
| 2356 | wr_mas->r_max = max; |
| 2357 | wr_mas->r_min = min; |
| 2358 | wr_mas->offset_end = mas->offset = offset; |
| 2359 | } |
| 2360 | |
| 2361 | /* |
| 2362 | * mas_topiary_range() - Add a range of slots to the topiary. |
| 2363 | * @mas: The maple state |
| 2364 | * @destroy: The topiary to add the slots (usually destroy) |
| 2365 | * @start: The starting slot inclusively |
| 2366 | * @end: The end slot inclusively |
| 2367 | */ |
| 2368 | static inline void mas_topiary_range(struct ma_state *mas, |
| 2369 | struct ma_topiary *destroy, unsigned char start, unsigned char end) |
| 2370 | { |
| 2371 | void __rcu **slots; |
| 2372 | unsigned char offset; |
| 2373 | |
| 2374 | MT_BUG_ON(mas->tree, mte_is_leaf(mas->node)); |
| 2375 | slots = ma_slots(mas_mn(mas), mte_node_type(mas->node)); |
| 2376 | for (offset = start; offset <= end; offset++) { |
| 2377 | struct maple_enode *enode = mas_slot_locked(mas, slots, offset); |
| 2378 | |
| 2379 | if (mte_dead_node(enode)) |
| 2380 | continue; |
| 2381 | |
| 2382 | mat_add(destroy, enode); |
| 2383 | } |
| 2384 | } |
| 2385 | |
| 2386 | /* |
| 2387 | * mast_topiary() - Add the portions of the tree to the removal list; either to |
| 2388 | * be freed or discarded (destroy walk). |
| 2389 | * @mast: The maple_subtree_state. |
| 2390 | */ |
| 2391 | static inline void mast_topiary(struct maple_subtree_state *mast) |
| 2392 | { |
| 2393 | MA_WR_STATE(wr_mas, mast->orig_l, NULL); |
| 2394 | unsigned char r_start, r_end; |
| 2395 | unsigned char l_start, l_end; |
| 2396 | void __rcu **l_slots, **r_slots; |
| 2397 | |
| 2398 | wr_mas.type = mte_node_type(mast->orig_l->node); |
| 2399 | mast->orig_l->index = mast->orig_l->last; |
| 2400 | mas_wr_node_walk(&wr_mas); |
| 2401 | l_start = mast->orig_l->offset + 1; |
| 2402 | l_end = mas_data_end(mast->orig_l); |
| 2403 | r_start = 0; |
| 2404 | r_end = mast->orig_r->offset; |
| 2405 | |
| 2406 | if (r_end) |
| 2407 | r_end--; |
| 2408 | |
| 2409 | l_slots = ma_slots(mas_mn(mast->orig_l), |
| 2410 | mte_node_type(mast->orig_l->node)); |
| 2411 | |
| 2412 | r_slots = ma_slots(mas_mn(mast->orig_r), |
| 2413 | mte_node_type(mast->orig_r->node)); |
| 2414 | |
| 2415 | if ((l_start < l_end) && |
| 2416 | mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_start))) { |
| 2417 | l_start++; |
| 2418 | } |
| 2419 | |
| 2420 | if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_end))) { |
| 2421 | if (r_end) |
| 2422 | r_end--; |
| 2423 | } |
| 2424 | |
| 2425 | if ((l_start > r_end) && (mast->orig_l->node == mast->orig_r->node)) |
| 2426 | return; |
| 2427 | |
| 2428 | /* At the node where left and right sides meet, add the parts between */ |
| 2429 | if (mast->orig_l->node == mast->orig_r->node) { |
| 2430 | return mas_topiary_range(mast->orig_l, mast->destroy, |
| 2431 | l_start, r_end); |
| 2432 | } |
| 2433 | |
| 2434 | /* mast->orig_r is different and consumed. */ |
| 2435 | if (mte_is_leaf(mast->orig_r->node)) |
| 2436 | return; |
| 2437 | |
| 2438 | if (mte_dead_node(mas_slot_locked(mast->orig_l, l_slots, l_end))) |
| 2439 | l_end--; |
| 2440 | |
| 2441 | |
| 2442 | if (l_start <= l_end) |
| 2443 | mas_topiary_range(mast->orig_l, mast->destroy, l_start, l_end); |
| 2444 | |
| 2445 | if (mte_dead_node(mas_slot_locked(mast->orig_r, r_slots, r_start))) |
| 2446 | r_start++; |
| 2447 | |
| 2448 | if (r_start <= r_end) |
| 2449 | mas_topiary_range(mast->orig_r, mast->destroy, 0, r_end); |
| 2450 | } |
| 2451 | |
| 2452 | /* |
| 2453 | * mast_rebalance_next() - Rebalance against the next node |
| 2454 | * @mast: The maple subtree state |
| 2455 | * @old_r: The encoded maple node to the right (next node). |
| 2456 | */ |
| 2457 | static inline void mast_rebalance_next(struct maple_subtree_state *mast) |
| 2458 | { |
| 2459 | unsigned char b_end = mast->bn->b_end; |
| 2460 | |
| 2461 | mas_mab_cp(mast->orig_r, 0, mt_slot_count(mast->orig_r->node), |
| 2462 | mast->bn, b_end); |
| 2463 | mast->orig_r->last = mast->orig_r->max; |
| 2464 | } |
| 2465 | |
| 2466 | /* |
| 2467 | * mast_rebalance_prev() - Rebalance against the previous node |
| 2468 | * @mast: The maple subtree state |
| 2469 | * @old_l: The encoded maple node to the left (previous node) |
| 2470 | */ |
| 2471 | static inline void mast_rebalance_prev(struct maple_subtree_state *mast) |
| 2472 | { |
| 2473 | unsigned char end = mas_data_end(mast->orig_l) + 1; |
| 2474 | unsigned char b_end = mast->bn->b_end; |
| 2475 | |
| 2476 | mab_shift_right(mast->bn, end); |
| 2477 | mas_mab_cp(mast->orig_l, 0, end - 1, mast->bn, 0); |
| 2478 | mast->l->min = mast->orig_l->min; |
| 2479 | mast->orig_l->index = mast->orig_l->min; |
| 2480 | mast->bn->b_end = end + b_end; |
| 2481 | mast->l->offset += end; |
| 2482 | } |
| 2483 | |
| 2484 | /* |
| 2485 | * mast_spanning_rebalance() - Rebalance nodes with nearest neighbour favouring |
| 2486 | * the node to the right. Checking the nodes to the right then the left at each |
| 2487 | * level upwards until root is reached. Free and destroy as needed. |
| 2488 | * Data is copied into the @mast->bn. |
| 2489 | * @mast: The maple_subtree_state. |
| 2490 | */ |
| 2491 | static inline |
| 2492 | bool mast_spanning_rebalance(struct maple_subtree_state *mast) |
| 2493 | { |
| 2494 | struct ma_state r_tmp = *mast->orig_r; |
| 2495 | struct ma_state l_tmp = *mast->orig_l; |
| 2496 | struct maple_enode *ancestor = NULL; |
| 2497 | unsigned char start, end; |
| 2498 | unsigned char depth = 0; |
| 2499 | |
| 2500 | r_tmp = *mast->orig_r; |
| 2501 | l_tmp = *mast->orig_l; |
| 2502 | do { |
| 2503 | mas_ascend(mast->orig_r); |
| 2504 | mas_ascend(mast->orig_l); |
| 2505 | depth++; |
| 2506 | if (!ancestor && |
| 2507 | (mast->orig_r->node == mast->orig_l->node)) { |
| 2508 | ancestor = mast->orig_r->node; |
| 2509 | end = mast->orig_r->offset - 1; |
| 2510 | start = mast->orig_l->offset + 1; |
| 2511 | } |
| 2512 | |
| 2513 | if (mast->orig_r->offset < mas_data_end(mast->orig_r)) { |
| 2514 | if (!ancestor) { |
| 2515 | ancestor = mast->orig_r->node; |
| 2516 | start = 0; |
| 2517 | } |
| 2518 | |
| 2519 | mast->orig_r->offset++; |
| 2520 | do { |
| 2521 | mas_descend(mast->orig_r); |
| 2522 | mast->orig_r->offset = 0; |
| 2523 | depth--; |
| 2524 | } while (depth); |
| 2525 | |
| 2526 | mast_rebalance_next(mast); |
| 2527 | do { |
| 2528 | unsigned char l_off = 0; |
| 2529 | struct maple_enode *child = r_tmp.node; |
| 2530 | |
| 2531 | mas_ascend(&r_tmp); |
| 2532 | if (ancestor == r_tmp.node) |
| 2533 | l_off = start; |
| 2534 | |
| 2535 | if (r_tmp.offset) |
| 2536 | r_tmp.offset--; |
| 2537 | |
| 2538 | if (l_off < r_tmp.offset) |
| 2539 | mas_topiary_range(&r_tmp, mast->destroy, |
| 2540 | l_off, r_tmp.offset); |
| 2541 | |
| 2542 | if (l_tmp.node != child) |
| 2543 | mat_add(mast->free, child); |
| 2544 | |
| 2545 | } while (r_tmp.node != ancestor); |
| 2546 | |
| 2547 | *mast->orig_l = l_tmp; |
| 2548 | return true; |
| 2549 | |
| 2550 | } else if (mast->orig_l->offset != 0) { |
| 2551 | if (!ancestor) { |
| 2552 | ancestor = mast->orig_l->node; |
| 2553 | end = mas_data_end(mast->orig_l); |
| 2554 | } |
| 2555 | |
| 2556 | mast->orig_l->offset--; |
| 2557 | do { |
| 2558 | mas_descend(mast->orig_l); |
| 2559 | mast->orig_l->offset = |
| 2560 | mas_data_end(mast->orig_l); |
| 2561 | depth--; |
| 2562 | } while (depth); |
| 2563 | |
| 2564 | mast_rebalance_prev(mast); |
| 2565 | do { |
| 2566 | unsigned char r_off; |
| 2567 | struct maple_enode *child = l_tmp.node; |
| 2568 | |
| 2569 | mas_ascend(&l_tmp); |
| 2570 | if (ancestor == l_tmp.node) |
| 2571 | r_off = end; |
| 2572 | else |
| 2573 | r_off = mas_data_end(&l_tmp); |
| 2574 | |
| 2575 | if (l_tmp.offset < r_off) |
| 2576 | l_tmp.offset++; |
| 2577 | |
| 2578 | if (l_tmp.offset < r_off) |
| 2579 | mas_topiary_range(&l_tmp, mast->destroy, |
| 2580 | l_tmp.offset, r_off); |
| 2581 | |
| 2582 | if (r_tmp.node != child) |
| 2583 | mat_add(mast->free, child); |
| 2584 | |
| 2585 | } while (l_tmp.node != ancestor); |
| 2586 | |
| 2587 | *mast->orig_r = r_tmp; |
| 2588 | return true; |
| 2589 | } |
| 2590 | } while (!mte_is_root(mast->orig_r->node)); |
| 2591 | |
| 2592 | *mast->orig_r = r_tmp; |
| 2593 | *mast->orig_l = l_tmp; |
| 2594 | return false; |
| 2595 | } |
| 2596 | |
| 2597 | /* |
| 2598 | * mast_ascend_free() - Add current original maple state nodes to the free list |
| 2599 | * and ascend. |
| 2600 | * @mast: the maple subtree state. |
| 2601 | * |
| 2602 | * Ascend the original left and right sides and add the previous nodes to the |
| 2603 | * free list. Set the slots to point to the correct location in the new nodes. |
| 2604 | */ |
| 2605 | static inline void |
| 2606 | mast_ascend_free(struct maple_subtree_state *mast) |
| 2607 | { |
| 2608 | MA_WR_STATE(wr_mas, mast->orig_r, NULL); |
| 2609 | struct maple_enode *left = mast->orig_l->node; |
| 2610 | struct maple_enode *right = mast->orig_r->node; |
| 2611 | |
| 2612 | mas_ascend(mast->orig_l); |
| 2613 | mas_ascend(mast->orig_r); |
| 2614 | mat_add(mast->free, left); |
| 2615 | |
| 2616 | if (left != right) |
| 2617 | mat_add(mast->free, right); |
| 2618 | |
| 2619 | mast->orig_r->offset = 0; |
| 2620 | mast->orig_r->index = mast->r->max; |
| 2621 | /* last should be larger than or equal to index */ |
| 2622 | if (mast->orig_r->last < mast->orig_r->index) |
| 2623 | mast->orig_r->last = mast->orig_r->index; |
| 2624 | /* |
| 2625 | * The node may not contain the value so set slot to ensure all |
| 2626 | * of the nodes contents are freed or destroyed. |
| 2627 | */ |
| 2628 | wr_mas.type = mte_node_type(mast->orig_r->node); |
| 2629 | mas_wr_node_walk(&wr_mas); |
| 2630 | /* Set up the left side of things */ |
| 2631 | mast->orig_l->offset = 0; |
| 2632 | mast->orig_l->index = mast->l->min; |
| 2633 | wr_mas.mas = mast->orig_l; |
| 2634 | wr_mas.type = mte_node_type(mast->orig_l->node); |
| 2635 | mas_wr_node_walk(&wr_mas); |
| 2636 | |
| 2637 | mast->bn->type = wr_mas.type; |
| 2638 | } |
| 2639 | |
| 2640 | /* |
| 2641 | * mas_new_ma_node() - Create and return a new maple node. Helper function. |
| 2642 | * @mas: the maple state with the allocations. |
| 2643 | * @b_node: the maple_big_node with the type encoding. |
| 2644 | * |
| 2645 | * Use the node type from the maple_big_node to allocate a new node from the |
| 2646 | * ma_state. This function exists mainly for code readability. |
| 2647 | * |
| 2648 | * Return: A new maple encoded node |
| 2649 | */ |
| 2650 | static inline struct maple_enode |
| 2651 | *mas_new_ma_node(struct ma_state *mas, struct maple_big_node *b_node) |
| 2652 | { |
| 2653 | return mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), b_node->type); |
| 2654 | } |
| 2655 | |
| 2656 | /* |
| 2657 | * mas_mab_to_node() - Set up right and middle nodes |
| 2658 | * |
| 2659 | * @mas: the maple state that contains the allocations. |
| 2660 | * @b_node: the node which contains the data. |
| 2661 | * @left: The pointer which will have the left node |
| 2662 | * @right: The pointer which may have the right node |
| 2663 | * @middle: the pointer which may have the middle node (rare) |
| 2664 | * @mid_split: the split location for the middle node |
| 2665 | * |
| 2666 | * Return: the split of left. |
| 2667 | */ |
| 2668 | static inline unsigned char mas_mab_to_node(struct ma_state *mas, |
| 2669 | struct maple_big_node *b_node, struct maple_enode **left, |
| 2670 | struct maple_enode **right, struct maple_enode **middle, |
| 2671 | unsigned char *mid_split, unsigned long min) |
| 2672 | { |
| 2673 | unsigned char split = 0; |
| 2674 | unsigned char slot_count = mt_slots[b_node->type]; |
| 2675 | |
| 2676 | *left = mas_new_ma_node(mas, b_node); |
| 2677 | *right = NULL; |
| 2678 | *middle = NULL; |
| 2679 | *mid_split = 0; |
| 2680 | |
| 2681 | if (b_node->b_end < slot_count) { |
| 2682 | split = b_node->b_end; |
| 2683 | } else { |
| 2684 | split = mab_calc_split(mas, b_node, mid_split, min); |
| 2685 | *right = mas_new_ma_node(mas, b_node); |
| 2686 | } |
| 2687 | |
| 2688 | if (*mid_split) |
| 2689 | *middle = mas_new_ma_node(mas, b_node); |
| 2690 | |
| 2691 | return split; |
| 2692 | |
| 2693 | } |
| 2694 | |
| 2695 | /* |
| 2696 | * mab_set_b_end() - Add entry to b_node at b_node->b_end and increment the end |
| 2697 | * pointer. |
| 2698 | * @b_node - the big node to add the entry |
| 2699 | * @mas - the maple state to get the pivot (mas->max) |
| 2700 | * @entry - the entry to add, if NULL nothing happens. |
| 2701 | */ |
| 2702 | static inline void mab_set_b_end(struct maple_big_node *b_node, |
| 2703 | struct ma_state *mas, |
| 2704 | void *entry) |
| 2705 | { |
| 2706 | if (!entry) |
| 2707 | return; |
| 2708 | |
| 2709 | b_node->slot[b_node->b_end] = entry; |
| 2710 | if (mt_is_alloc(mas->tree)) |
| 2711 | b_node->gap[b_node->b_end] = mas_max_gap(mas); |
| 2712 | b_node->pivot[b_node->b_end++] = mas->max; |
| 2713 | } |
| 2714 | |
| 2715 | /* |
| 2716 | * mas_set_split_parent() - combine_then_separate helper function. Sets the parent |
| 2717 | * of @mas->node to either @left or @right, depending on @slot and @split |
| 2718 | * |
| 2719 | * @mas - the maple state with the node that needs a parent |
| 2720 | * @left - possible parent 1 |
| 2721 | * @right - possible parent 2 |
| 2722 | * @slot - the slot the mas->node was placed |
| 2723 | * @split - the split location between @left and @right |
| 2724 | */ |
| 2725 | static inline void mas_set_split_parent(struct ma_state *mas, |
| 2726 | struct maple_enode *left, |
| 2727 | struct maple_enode *right, |
| 2728 | unsigned char *slot, unsigned char split) |
| 2729 | { |
| 2730 | if (mas_is_none(mas)) |
| 2731 | return; |
| 2732 | |
| 2733 | if ((*slot) <= split) |
| 2734 | mte_set_parent(mas->node, left, *slot); |
| 2735 | else if (right) |
| 2736 | mte_set_parent(mas->node, right, (*slot) - split - 1); |
| 2737 | |
| 2738 | (*slot)++; |
| 2739 | } |
| 2740 | |
| 2741 | /* |
| 2742 | * mte_mid_split_check() - Check if the next node passes the mid-split |
| 2743 | * @**l: Pointer to left encoded maple node. |
| 2744 | * @**m: Pointer to middle encoded maple node. |
| 2745 | * @**r: Pointer to right encoded maple node. |
| 2746 | * @slot: The offset |
| 2747 | * @*split: The split location. |
| 2748 | * @mid_split: The middle split. |
| 2749 | */ |
| 2750 | static inline void mte_mid_split_check(struct maple_enode **l, |
| 2751 | struct maple_enode **r, |
| 2752 | struct maple_enode *right, |
| 2753 | unsigned char slot, |
| 2754 | unsigned char *split, |
| 2755 | unsigned char mid_split) |
| 2756 | { |
| 2757 | if (*r == right) |
| 2758 | return; |
| 2759 | |
| 2760 | if (slot < mid_split) |
| 2761 | return; |
| 2762 | |
| 2763 | *l = *r; |
| 2764 | *r = right; |
| 2765 | *split = mid_split; |
| 2766 | } |
| 2767 | |
| 2768 | /* |
| 2769 | * mast_set_split_parents() - Helper function to set three nodes parents. Slot |
| 2770 | * is taken from @mast->l. |
| 2771 | * @mast - the maple subtree state |
| 2772 | * @left - the left node |
| 2773 | * @right - the right node |
| 2774 | * @split - the split location. |
| 2775 | */ |
| 2776 | static inline void mast_set_split_parents(struct maple_subtree_state *mast, |
| 2777 | struct maple_enode *left, |
| 2778 | struct maple_enode *middle, |
| 2779 | struct maple_enode *right, |
| 2780 | unsigned char split, |
| 2781 | unsigned char mid_split) |
| 2782 | { |
| 2783 | unsigned char slot; |
| 2784 | struct maple_enode *l = left; |
| 2785 | struct maple_enode *r = right; |
| 2786 | |
| 2787 | if (mas_is_none(mast->l)) |
| 2788 | return; |
| 2789 | |
| 2790 | if (middle) |
| 2791 | r = middle; |
| 2792 | |
| 2793 | slot = mast->l->offset; |
| 2794 | |
| 2795 | mte_mid_split_check(&l, &r, right, slot, &split, mid_split); |
| 2796 | mas_set_split_parent(mast->l, l, r, &slot, split); |
| 2797 | |
| 2798 | mte_mid_split_check(&l, &r, right, slot, &split, mid_split); |
| 2799 | mas_set_split_parent(mast->m, l, r, &slot, split); |
| 2800 | |
| 2801 | mte_mid_split_check(&l, &r, right, slot, &split, mid_split); |
| 2802 | mas_set_split_parent(mast->r, l, r, &slot, split); |
| 2803 | } |
| 2804 | |
| 2805 | /* |
| 2806 | * mas_wmb_replace() - Write memory barrier and replace |
| 2807 | * @mas: The maple state |
| 2808 | * @free: the maple topiary list of nodes to free |
| 2809 | * @destroy: The maple topiary list of nodes to destroy (walk and free) |
| 2810 | * |
| 2811 | * Updates gap as necessary. |
| 2812 | */ |
| 2813 | static inline void mas_wmb_replace(struct ma_state *mas, |
| 2814 | struct ma_topiary *free, |
| 2815 | struct ma_topiary *destroy) |
| 2816 | { |
| 2817 | /* All nodes must see old data as dead prior to replacing that data */ |
| 2818 | smp_wmb(); /* Needed for RCU */ |
| 2819 | |
| 2820 | /* Insert the new data in the tree */ |
| 2821 | mas_replace(mas, true); |
| 2822 | |
| 2823 | if (!mte_is_leaf(mas->node)) |
| 2824 | mas_descend_adopt(mas); |
| 2825 | |
| 2826 | mas_mat_free(mas, free); |
| 2827 | |
| 2828 | if (destroy) |
| 2829 | mas_mat_destroy(mas, destroy); |
| 2830 | |
| 2831 | if (mte_is_leaf(mas->node)) |
| 2832 | return; |
| 2833 | |
| 2834 | mas_update_gap(mas); |
| 2835 | } |
| 2836 | |
| 2837 | /* |
| 2838 | * mast_new_root() - Set a new tree root during subtree creation |
| 2839 | * @mast: The maple subtree state |
| 2840 | * @mas: The maple state |
| 2841 | */ |
| 2842 | static inline void mast_new_root(struct maple_subtree_state *mast, |
| 2843 | struct ma_state *mas) |
| 2844 | { |
| 2845 | mas_mn(mast->l)->parent = |
| 2846 | ma_parent_ptr(((unsigned long)mas->tree | MA_ROOT_PARENT)); |
| 2847 | if (!mte_dead_node(mast->orig_l->node) && |
| 2848 | !mte_is_root(mast->orig_l->node)) { |
| 2849 | do { |
| 2850 | mast_ascend_free(mast); |
| 2851 | mast_topiary(mast); |
| 2852 | } while (!mte_is_root(mast->orig_l->node)); |
| 2853 | } |
| 2854 | if ((mast->orig_l->node != mas->node) && |
| 2855 | (mast->l->depth > mas_mt_height(mas))) { |
| 2856 | mat_add(mast->free, mas->node); |
| 2857 | } |
| 2858 | } |
| 2859 | |
| 2860 | /* |
| 2861 | * mast_cp_to_nodes() - Copy data out to nodes. |
| 2862 | * @mast: The maple subtree state |
| 2863 | * @left: The left encoded maple node |
| 2864 | * @middle: The middle encoded maple node |
| 2865 | * @right: The right encoded maple node |
| 2866 | * @split: The location to split between left and (middle ? middle : right) |
| 2867 | * @mid_split: The location to split between middle and right. |
| 2868 | */ |
| 2869 | static inline void mast_cp_to_nodes(struct maple_subtree_state *mast, |
| 2870 | struct maple_enode *left, struct maple_enode *middle, |
| 2871 | struct maple_enode *right, unsigned char split, unsigned char mid_split) |
| 2872 | { |
| 2873 | bool new_lmax = true; |
| 2874 | |
| 2875 | mast->l->node = mte_node_or_none(left); |
| 2876 | mast->m->node = mte_node_or_none(middle); |
| 2877 | mast->r->node = mte_node_or_none(right); |
| 2878 | |
| 2879 | mast->l->min = mast->orig_l->min; |
| 2880 | if (split == mast->bn->b_end) { |
| 2881 | mast->l->max = mast->orig_r->max; |
| 2882 | new_lmax = false; |
| 2883 | } |
| 2884 | |
| 2885 | mab_mas_cp(mast->bn, 0, split, mast->l, new_lmax); |
| 2886 | |
| 2887 | if (middle) { |
| 2888 | mab_mas_cp(mast->bn, 1 + split, mid_split, mast->m, true); |
| 2889 | mast->m->min = mast->bn->pivot[split] + 1; |
| 2890 | split = mid_split; |
| 2891 | } |
| 2892 | |
| 2893 | mast->r->max = mast->orig_r->max; |
| 2894 | if (right) { |
| 2895 | mab_mas_cp(mast->bn, 1 + split, mast->bn->b_end, mast->r, false); |
| 2896 | mast->r->min = mast->bn->pivot[split] + 1; |
| 2897 | } |
| 2898 | } |
| 2899 | |
| 2900 | /* |
| 2901 | * mast_combine_cp_left - Copy in the original left side of the tree into the |
| 2902 | * combined data set in the maple subtree state big node. |
| 2903 | * @mast: The maple subtree state |
| 2904 | */ |
| 2905 | static inline void mast_combine_cp_left(struct maple_subtree_state *mast) |
| 2906 | { |
| 2907 | unsigned char l_slot = mast->orig_l->offset; |
| 2908 | |
| 2909 | if (!l_slot) |
| 2910 | return; |
| 2911 | |
| 2912 | mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0); |
| 2913 | } |
| 2914 | |
| 2915 | /* |
| 2916 | * mast_combine_cp_right: Copy in the original right side of the tree into the |
| 2917 | * combined data set in the maple subtree state big node. |
| 2918 | * @mast: The maple subtree state |
| 2919 | */ |
| 2920 | static inline void mast_combine_cp_right(struct maple_subtree_state *mast) |
| 2921 | { |
| 2922 | if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max) |
| 2923 | return; |
| 2924 | |
| 2925 | mas_mab_cp(mast->orig_r, mast->orig_r->offset + 1, |
| 2926 | mt_slot_count(mast->orig_r->node), mast->bn, |
| 2927 | mast->bn->b_end); |
| 2928 | mast->orig_r->last = mast->orig_r->max; |
| 2929 | } |
| 2930 | |
| 2931 | /* |
| 2932 | * mast_sufficient: Check if the maple subtree state has enough data in the big |
| 2933 | * node to create at least one sufficient node |
| 2934 | * @mast: the maple subtree state |
| 2935 | */ |
| 2936 | static inline bool mast_sufficient(struct maple_subtree_state *mast) |
| 2937 | { |
| 2938 | if (mast->bn->b_end > mt_min_slot_count(mast->orig_l->node)) |
| 2939 | return true; |
| 2940 | |
| 2941 | return false; |
| 2942 | } |
| 2943 | |
| 2944 | /* |
| 2945 | * mast_overflow: Check if there is too much data in the subtree state for a |
| 2946 | * single node. |
| 2947 | * @mast: The maple subtree state |
| 2948 | */ |
| 2949 | static inline bool mast_overflow(struct maple_subtree_state *mast) |
| 2950 | { |
| 2951 | if (mast->bn->b_end >= mt_slot_count(mast->orig_l->node)) |
| 2952 | return true; |
| 2953 | |
| 2954 | return false; |
| 2955 | } |
| 2956 | |
| 2957 | static inline void *mtree_range_walk(struct ma_state *mas) |
| 2958 | { |
| 2959 | unsigned long *pivots; |
| 2960 | unsigned char offset; |
| 2961 | struct maple_node *node; |
| 2962 | struct maple_enode *next, *last; |
| 2963 | enum maple_type type; |
| 2964 | void __rcu **slots; |
| 2965 | unsigned char end; |
| 2966 | unsigned long max, min; |
| 2967 | unsigned long prev_max, prev_min; |
| 2968 | |
| 2969 | next = mas->node; |
| 2970 | min = mas->min; |
| 2971 | max = mas->max; |
| 2972 | do { |
| 2973 | offset = 0; |
| 2974 | last = next; |
| 2975 | node = mte_to_node(next); |
| 2976 | type = mte_node_type(next); |
| 2977 | pivots = ma_pivots(node, type); |
| 2978 | end = ma_data_end(node, type, pivots, max); |
| 2979 | if (unlikely(ma_dead_node(node))) |
| 2980 | goto dead_node; |
| 2981 | |
| 2982 | if (pivots[offset] >= mas->index) { |
| 2983 | prev_max = max; |
| 2984 | prev_min = min; |
| 2985 | max = pivots[offset]; |
| 2986 | goto next; |
| 2987 | } |
| 2988 | |
| 2989 | do { |
| 2990 | offset++; |
| 2991 | } while ((offset < end) && (pivots[offset] < mas->index)); |
| 2992 | |
| 2993 | prev_min = min; |
| 2994 | min = pivots[offset - 1] + 1; |
| 2995 | prev_max = max; |
| 2996 | if (likely(offset < end && pivots[offset])) |
| 2997 | max = pivots[offset]; |
| 2998 | |
| 2999 | next: |
| 3000 | slots = ma_slots(node, type); |
| 3001 | next = mt_slot(mas->tree, slots, offset); |
| 3002 | if (unlikely(ma_dead_node(node))) |
| 3003 | goto dead_node; |
| 3004 | } while (!ma_is_leaf(type)); |
| 3005 | |
| 3006 | mas->offset = offset; |
| 3007 | mas->index = min; |
| 3008 | mas->last = max; |
| 3009 | mas->min = prev_min; |
| 3010 | mas->max = prev_max; |
| 3011 | mas->node = last; |
| 3012 | return (void *)next; |
| 3013 | |
| 3014 | dead_node: |
| 3015 | mas_reset(mas); |
| 3016 | return NULL; |
| 3017 | } |
| 3018 | |
| 3019 | /* |
| 3020 | * mas_spanning_rebalance() - Rebalance across two nodes which may not be peers. |
| 3021 | * @mas: The starting maple state |
| 3022 | * @mast: The maple_subtree_state, keeps track of 4 maple states. |
| 3023 | * @count: The estimated count of iterations needed. |
| 3024 | * |
| 3025 | * Follow the tree upwards from @l_mas and @r_mas for @count, or until the root |
| 3026 | * is hit. First @b_node is split into two entries which are inserted into the |
| 3027 | * next iteration of the loop. @b_node is returned populated with the final |
| 3028 | * iteration. @mas is used to obtain allocations. orig_l_mas keeps track of the |
| 3029 | * nodes that will remain active by using orig_l_mas->index and orig_l_mas->last |
| 3030 | * to account of what has been copied into the new sub-tree. The update of |
| 3031 | * orig_l_mas->last is used in mas_consume to find the slots that will need to |
| 3032 | * be either freed or destroyed. orig_l_mas->depth keeps track of the height of |
| 3033 | * the new sub-tree in case the sub-tree becomes the full tree. |
| 3034 | * |
| 3035 | * Return: the number of elements in b_node during the last loop. |
| 3036 | */ |
| 3037 | static int mas_spanning_rebalance(struct ma_state *mas, |
| 3038 | struct maple_subtree_state *mast, unsigned char count) |
| 3039 | { |
| 3040 | unsigned char split, mid_split; |
| 3041 | unsigned char slot = 0; |
| 3042 | struct maple_enode *left = NULL, *middle = NULL, *right = NULL; |
| 3043 | |
| 3044 | MA_STATE(l_mas, mas->tree, mas->index, mas->index); |
| 3045 | MA_STATE(r_mas, mas->tree, mas->index, mas->last); |
| 3046 | MA_STATE(m_mas, mas->tree, mas->index, mas->index); |
| 3047 | MA_TOPIARY(free, mas->tree); |
| 3048 | MA_TOPIARY(destroy, mas->tree); |
| 3049 | |
| 3050 | /* |
| 3051 | * The tree needs to be rebalanced and leaves need to be kept at the same level. |
| 3052 | * Rebalancing is done by use of the ``struct maple_topiary``. |
| 3053 | */ |
| 3054 | mast->l = &l_mas; |
| 3055 | mast->m = &m_mas; |
| 3056 | mast->r = &r_mas; |
| 3057 | mast->free = &free; |
| 3058 | mast->destroy = &destroy; |
| 3059 | l_mas.node = r_mas.node = m_mas.node = MAS_NONE; |
| 3060 | |
| 3061 | /* Check if this is not root and has sufficient data. */ |
| 3062 | if (((mast->orig_l->min != 0) || (mast->orig_r->max != ULONG_MAX)) && |
| 3063 | unlikely(mast->bn->b_end <= mt_min_slots[mast->bn->type])) |
| 3064 | mast_spanning_rebalance(mast); |
| 3065 | |
| 3066 | mast->orig_l->depth = 0; |
| 3067 | |
| 3068 | /* |
| 3069 | * Each level of the tree is examined and balanced, pushing data to the left or |
| 3070 | * right, or rebalancing against left or right nodes is employed to avoid |
| 3071 | * rippling up the tree to limit the amount of churn. Once a new sub-section of |
| 3072 | * the tree is created, there may be a mix of new and old nodes. The old nodes |
| 3073 | * will have the incorrect parent pointers and currently be in two trees: the |
| 3074 | * original tree and the partially new tree. To remedy the parent pointers in |
| 3075 | * the old tree, the new data is swapped into the active tree and a walk down |
| 3076 | * the tree is performed and the parent pointers are updated. |
| 3077 | * See mas_descend_adopt() for more information.. |
| 3078 | */ |
| 3079 | while (count--) { |
| 3080 | mast->bn->b_end--; |
| 3081 | mast->bn->type = mte_node_type(mast->orig_l->node); |
| 3082 | split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle, |
| 3083 | &mid_split, mast->orig_l->min); |
| 3084 | mast_set_split_parents(mast, left, middle, right, split, |
| 3085 | mid_split); |
| 3086 | mast_cp_to_nodes(mast, left, middle, right, split, mid_split); |
| 3087 | |
| 3088 | /* |
| 3089 | * Copy data from next level in the tree to mast->bn from next |
| 3090 | * iteration |
| 3091 | */ |
| 3092 | memset(mast->bn, 0, sizeof(struct maple_big_node)); |
| 3093 | mast->bn->type = mte_node_type(left); |
| 3094 | mast->orig_l->depth++; |
| 3095 | |
| 3096 | /* Root already stored in l->node. */ |
| 3097 | if (mas_is_root_limits(mast->l)) |
| 3098 | goto new_root; |
| 3099 | |
| 3100 | mast_ascend_free(mast); |
| 3101 | mast_combine_cp_left(mast); |
| 3102 | l_mas.offset = mast->bn->b_end; |
| 3103 | mab_set_b_end(mast->bn, &l_mas, left); |
| 3104 | mab_set_b_end(mast->bn, &m_mas, middle); |
| 3105 | mab_set_b_end(mast->bn, &r_mas, right); |
| 3106 | |
| 3107 | /* Copy anything necessary out of the right node. */ |
| 3108 | mast_combine_cp_right(mast); |
| 3109 | mast_topiary(mast); |
| 3110 | mast->orig_l->last = mast->orig_l->max; |
| 3111 | |
| 3112 | if (mast_sufficient(mast)) |
| 3113 | continue; |
| 3114 | |
| 3115 | if (mast_overflow(mast)) |
| 3116 | continue; |
| 3117 | |
| 3118 | /* May be a new root stored in mast->bn */ |
| 3119 | if (mas_is_root_limits(mast->orig_l)) |
| 3120 | break; |
| 3121 | |
| 3122 | mast_spanning_rebalance(mast); |
| 3123 | |
| 3124 | /* rebalancing from other nodes may require another loop. */ |
| 3125 | if (!count) |
| 3126 | count++; |
| 3127 | } |
| 3128 | |
| 3129 | l_mas.node = mt_mk_node(ma_mnode_ptr(mas_pop_node(mas)), |
| 3130 | mte_node_type(mast->orig_l->node)); |
| 3131 | mast->orig_l->depth++; |
| 3132 | mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, &l_mas, true); |
| 3133 | mte_set_parent(left, l_mas.node, slot); |
| 3134 | if (middle) |
| 3135 | mte_set_parent(middle, l_mas.node, ++slot); |
| 3136 | |
| 3137 | if (right) |
| 3138 | mte_set_parent(right, l_mas.node, ++slot); |
| 3139 | |
| 3140 | if (mas_is_root_limits(mast->l)) { |
| 3141 | new_root: |
| 3142 | mast_new_root(mast, mas); |
| 3143 | } else { |
| 3144 | mas_mn(&l_mas)->parent = mas_mn(mast->orig_l)->parent; |
| 3145 | } |
| 3146 | |
| 3147 | if (!mte_dead_node(mast->orig_l->node)) |
| 3148 | mat_add(&free, mast->orig_l->node); |
| 3149 | |
| 3150 | mas->depth = mast->orig_l->depth; |
| 3151 | *mast->orig_l = l_mas; |
| 3152 | mte_set_node_dead(mas->node); |
| 3153 | |
| 3154 | /* Set up mas for insertion. */ |
| 3155 | mast->orig_l->depth = mas->depth; |
| 3156 | mast->orig_l->alloc = mas->alloc; |
| 3157 | *mas = *mast->orig_l; |
| 3158 | mas_wmb_replace(mas, &free, &destroy); |
| 3159 | mtree_range_walk(mas); |
| 3160 | return mast->bn->b_end; |
| 3161 | } |
| 3162 | |
| 3163 | /* |
| 3164 | * mas_rebalance() - Rebalance a given node. |
| 3165 | * @mas: The maple state |
| 3166 | * @b_node: The big maple node. |
| 3167 | * |
| 3168 | * Rebalance two nodes into a single node or two new nodes that are sufficient. |
| 3169 | * Continue upwards until tree is sufficient. |
| 3170 | * |
| 3171 | * Return: the number of elements in b_node during the last loop. |
| 3172 | */ |
| 3173 | static inline int mas_rebalance(struct ma_state *mas, |
| 3174 | struct maple_big_node *b_node) |
| 3175 | { |
| 3176 | char empty_count = mas_mt_height(mas); |
| 3177 | struct maple_subtree_state mast; |
| 3178 | unsigned char shift, b_end = ++b_node->b_end; |
| 3179 | |
| 3180 | MA_STATE(l_mas, mas->tree, mas->index, mas->last); |
| 3181 | MA_STATE(r_mas, mas->tree, mas->index, mas->last); |
| 3182 | |
| 3183 | trace_ma_op(__func__, mas); |
| 3184 | |
| 3185 | /* |
| 3186 | * Rebalancing occurs if a node is insufficient. Data is rebalanced |
| 3187 | * against the node to the right if it exists, otherwise the node to the |
| 3188 | * left of this node is rebalanced against this node. If rebalancing |
| 3189 | * causes just one node to be produced instead of two, then the parent |
| 3190 | * is also examined and rebalanced if it is insufficient. Every level |
| 3191 | * tries to combine the data in the same way. If one node contains the |
| 3192 | * entire range of the tree, then that node is used as a new root node. |
| 3193 | */ |
| 3194 | mas_node_count(mas, 1 + empty_count * 3); |
| 3195 | if (mas_is_err(mas)) |
| 3196 | return 0; |
| 3197 | |
| 3198 | mast.orig_l = &l_mas; |
| 3199 | mast.orig_r = &r_mas; |
| 3200 | mast.bn = b_node; |
| 3201 | mast.bn->type = mte_node_type(mas->node); |
| 3202 | |
| 3203 | l_mas = r_mas = *mas; |
| 3204 | |
| 3205 | if (mas_next_sibling(&r_mas)) { |
| 3206 | mas_mab_cp(&r_mas, 0, mt_slot_count(r_mas.node), b_node, b_end); |
| 3207 | r_mas.last = r_mas.index = r_mas.max; |
| 3208 | } else { |
| 3209 | mas_prev_sibling(&l_mas); |
| 3210 | shift = mas_data_end(&l_mas) + 1; |
| 3211 | mab_shift_right(b_node, shift); |
| 3212 | mas->offset += shift; |
| 3213 | mas_mab_cp(&l_mas, 0, shift - 1, b_node, 0); |
| 3214 | b_node->b_end = shift + b_end; |
| 3215 | l_mas.index = l_mas.last = l_mas.min; |
| 3216 | } |
| 3217 | |
| 3218 | return mas_spanning_rebalance(mas, &mast, empty_count); |
| 3219 | } |
| 3220 | |
| 3221 | /* |
| 3222 | * mas_destroy_rebalance() - Rebalance left-most node while destroying the maple |
| 3223 | * state. |
| 3224 | * @mas: The maple state |
| 3225 | * @end: The end of the left-most node. |
| 3226 | * |
| 3227 | * During a mass-insert event (such as forking), it may be necessary to |
| 3228 | * rebalance the left-most node when it is not sufficient. |
| 3229 | */ |
| 3230 | static inline void mas_destroy_rebalance(struct ma_state *mas, unsigned char end) |
| 3231 | { |
| 3232 | enum maple_type mt = mte_node_type(mas->node); |
| 3233 | struct maple_node reuse, *newnode, *parent, *new_left, *left, *node; |
| 3234 | struct maple_enode *eparent; |
| 3235 | unsigned char offset, tmp, split = mt_slots[mt] / 2; |
| 3236 | void __rcu **l_slots, **slots; |
| 3237 | unsigned long *l_pivs, *pivs, gap; |
| 3238 | bool in_rcu = mt_in_rcu(mas->tree); |
| 3239 | |
| 3240 | MA_STATE(l_mas, mas->tree, mas->index, mas->last); |
| 3241 | |
| 3242 | l_mas = *mas; |
| 3243 | mas_prev_sibling(&l_mas); |
| 3244 | |
| 3245 | /* set up node. */ |
| 3246 | if (in_rcu) { |
| 3247 | /* Allocate for both left and right as well as parent. */ |
| 3248 | mas_node_count(mas, 3); |
| 3249 | if (mas_is_err(mas)) |
| 3250 | return; |
| 3251 | |
| 3252 | newnode = mas_pop_node(mas); |
| 3253 | } else { |
| 3254 | newnode = &reuse; |
| 3255 | } |
| 3256 | |
| 3257 | node = mas_mn(mas); |
| 3258 | newnode->parent = node->parent; |
| 3259 | slots = ma_slots(newnode, mt); |
| 3260 | pivs = ma_pivots(newnode, mt); |
| 3261 | left = mas_mn(&l_mas); |
| 3262 | l_slots = ma_slots(left, mt); |
| 3263 | l_pivs = ma_pivots(left, mt); |
| 3264 | if (!l_slots[split]) |
| 3265 | split++; |
| 3266 | tmp = mas_data_end(&l_mas) - split; |
| 3267 | |
| 3268 | memcpy(slots, l_slots + split + 1, sizeof(void *) * tmp); |
| 3269 | memcpy(pivs, l_pivs + split + 1, sizeof(unsigned long) * tmp); |
| 3270 | pivs[tmp] = l_mas.max; |
| 3271 | memcpy(slots + tmp, ma_slots(node, mt), sizeof(void *) * end); |
| 3272 | memcpy(pivs + tmp, ma_pivots(node, mt), sizeof(unsigned long) * end); |
| 3273 | |
| 3274 | l_mas.max = l_pivs[split]; |
| 3275 | mas->min = l_mas.max + 1; |
| 3276 | eparent = mt_mk_node(mte_parent(l_mas.node), |
| 3277 | mas_parent_enum(&l_mas, l_mas.node)); |
| 3278 | tmp += end; |
| 3279 | if (!in_rcu) { |
| 3280 | unsigned char max_p = mt_pivots[mt]; |
| 3281 | unsigned char max_s = mt_slots[mt]; |
| 3282 | |
| 3283 | if (tmp < max_p) |
| 3284 | memset(pivs + tmp, 0, |
| 3285 | sizeof(unsigned long *) * (max_p - tmp)); |
| 3286 | |
| 3287 | if (tmp < mt_slots[mt]) |
| 3288 | memset(slots + tmp, 0, sizeof(void *) * (max_s - tmp)); |
| 3289 | |
| 3290 | memcpy(node, newnode, sizeof(struct maple_node)); |
| 3291 | ma_set_meta(node, mt, 0, tmp - 1); |
| 3292 | mte_set_pivot(eparent, mte_parent_slot(l_mas.node), |
| 3293 | l_pivs[split]); |
| 3294 | |
| 3295 | /* Remove data from l_pivs. */ |
| 3296 | tmp = split + 1; |
| 3297 | memset(l_pivs + tmp, 0, sizeof(unsigned long) * (max_p - tmp)); |
| 3298 | memset(l_slots + tmp, 0, sizeof(void *) * (max_s - tmp)); |
| 3299 | ma_set_meta(left, mt, 0, split); |
| 3300 | |
| 3301 | goto done; |
| 3302 | } |
| 3303 | |
| 3304 | /* RCU requires replacing both l_mas, mas, and parent. */ |
| 3305 | mas->node = mt_mk_node(newnode, mt); |
| 3306 | ma_set_meta(newnode, mt, 0, tmp); |
| 3307 | |
| 3308 | new_left = mas_pop_node(mas); |
| 3309 | new_left->parent = left->parent; |
| 3310 | mt = mte_node_type(l_mas.node); |
| 3311 | slots = ma_slots(new_left, mt); |
| 3312 | pivs = ma_pivots(new_left, mt); |
| 3313 | memcpy(slots, l_slots, sizeof(void *) * split); |
| 3314 | memcpy(pivs, l_pivs, sizeof(unsigned long) * split); |
| 3315 | ma_set_meta(new_left, mt, 0, split); |
| 3316 | l_mas.node = mt_mk_node(new_left, mt); |
| 3317 | |
| 3318 | /* replace parent. */ |
| 3319 | offset = mte_parent_slot(mas->node); |
| 3320 | mt = mas_parent_enum(&l_mas, l_mas.node); |
| 3321 | parent = mas_pop_node(mas); |
| 3322 | slots = ma_slots(parent, mt); |
| 3323 | pivs = ma_pivots(parent, mt); |
| 3324 | memcpy(parent, mte_to_node(eparent), sizeof(struct maple_node)); |
| 3325 | rcu_assign_pointer(slots[offset], mas->node); |
| 3326 | rcu_assign_pointer(slots[offset - 1], l_mas.node); |
| 3327 | pivs[offset - 1] = l_mas.max; |
| 3328 | eparent = mt_mk_node(parent, mt); |
| 3329 | done: |
| 3330 | gap = mas_leaf_max_gap(mas); |
| 3331 | mte_set_gap(eparent, mte_parent_slot(mas->node), gap); |
| 3332 | gap = mas_leaf_max_gap(&l_mas); |
| 3333 | mte_set_gap(eparent, mte_parent_slot(l_mas.node), gap); |
| 3334 | mas_ascend(mas); |
| 3335 | |
| 3336 | if (in_rcu) |
| 3337 | mas_replace(mas, false); |
| 3338 | |
| 3339 | mas_update_gap(mas); |
| 3340 | } |
| 3341 | |
| 3342 | /* |
| 3343 | * mas_split_final_node() - Split the final node in a subtree operation. |
| 3344 | * @mast: the maple subtree state |
| 3345 | * @mas: The maple state |
| 3346 | * @height: The height of the tree in case it's a new root. |
| 3347 | */ |
| 3348 | static inline bool mas_split_final_node(struct maple_subtree_state *mast, |
| 3349 | struct ma_state *mas, int height) |
| 3350 | { |
| 3351 | struct maple_enode *ancestor; |
| 3352 | |
| 3353 | if (mte_is_root(mas->node)) { |
| 3354 | if (mt_is_alloc(mas->tree)) |
| 3355 | mast->bn->type = maple_arange_64; |
| 3356 | else |
| 3357 | mast->bn->type = maple_range_64; |
| 3358 | mas->depth = height; |
| 3359 | } |
| 3360 | /* |
| 3361 | * Only a single node is used here, could be root. |
| 3362 | * The Big_node data should just fit in a single node. |
| 3363 | */ |
| 3364 | ancestor = mas_new_ma_node(mas, mast->bn); |
| 3365 | mte_set_parent(mast->l->node, ancestor, mast->l->offset); |
| 3366 | mte_set_parent(mast->r->node, ancestor, mast->r->offset); |
| 3367 | mte_to_node(ancestor)->parent = mas_mn(mas)->parent; |
| 3368 | |
| 3369 | mast->l->node = ancestor; |
| 3370 | mab_mas_cp(mast->bn, 0, mt_slots[mast->bn->type] - 1, mast->l, true); |
| 3371 | mas->offset = mast->bn->b_end - 1; |
| 3372 | return true; |
| 3373 | } |
| 3374 | |
| 3375 | /* |
| 3376 | * mast_fill_bnode() - Copy data into the big node in the subtree state |
| 3377 | * @mast: The maple subtree state |
| 3378 | * @mas: the maple state |
| 3379 | * @skip: The number of entries to skip for new nodes insertion. |
| 3380 | */ |
| 3381 | static inline void mast_fill_bnode(struct maple_subtree_state *mast, |
| 3382 | struct ma_state *mas, |
| 3383 | unsigned char skip) |
| 3384 | { |
| 3385 | bool cp = true; |
| 3386 | struct maple_enode *old = mas->node; |
| 3387 | unsigned char split; |
| 3388 | |
| 3389 | memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap)); |
| 3390 | memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot)); |
| 3391 | memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot)); |
| 3392 | mast->bn->b_end = 0; |
| 3393 | |
| 3394 | if (mte_is_root(mas->node)) { |
| 3395 | cp = false; |
| 3396 | } else { |
| 3397 | mas_ascend(mas); |
| 3398 | mat_add(mast->free, old); |
| 3399 | mas->offset = mte_parent_slot(mas->node); |
| 3400 | } |
| 3401 | |
| 3402 | if (cp && mast->l->offset) |
| 3403 | mas_mab_cp(mas, 0, mast->l->offset - 1, mast->bn, 0); |
| 3404 | |
| 3405 | split = mast->bn->b_end; |
| 3406 | mab_set_b_end(mast->bn, mast->l, mast->l->node); |
| 3407 | mast->r->offset = mast->bn->b_end; |
| 3408 | mab_set_b_end(mast->bn, mast->r, mast->r->node); |
| 3409 | if (mast->bn->pivot[mast->bn->b_end - 1] == mas->max) |
| 3410 | cp = false; |
| 3411 | |
| 3412 | if (cp) |
| 3413 | mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1, |
| 3414 | mast->bn, mast->bn->b_end); |
| 3415 | |
| 3416 | mast->bn->b_end--; |
| 3417 | mast->bn->type = mte_node_type(mas->node); |
| 3418 | } |
| 3419 | |
| 3420 | /* |
| 3421 | * mast_split_data() - Split the data in the subtree state big node into regular |
| 3422 | * nodes. |
| 3423 | * @mast: The maple subtree state |
| 3424 | * @mas: The maple state |
| 3425 | * @split: The location to split the big node |
| 3426 | */ |
| 3427 | static inline void mast_split_data(struct maple_subtree_state *mast, |
| 3428 | struct ma_state *mas, unsigned char split) |
| 3429 | { |
| 3430 | unsigned char p_slot; |
| 3431 | |
| 3432 | mab_mas_cp(mast->bn, 0, split, mast->l, true); |
| 3433 | mte_set_pivot(mast->r->node, 0, mast->r->max); |
| 3434 | mab_mas_cp(mast->bn, split + 1, mast->bn->b_end, mast->r, false); |
| 3435 | mast->l->offset = mte_parent_slot(mas->node); |
| 3436 | mast->l->max = mast->bn->pivot[split]; |
| 3437 | mast->r->min = mast->l->max + 1; |
| 3438 | if (mte_is_leaf(mas->node)) |
| 3439 | return; |
| 3440 | |
| 3441 | p_slot = mast->orig_l->offset; |
| 3442 | mas_set_split_parent(mast->orig_l, mast->l->node, mast->r->node, |
| 3443 | &p_slot, split); |
| 3444 | mas_set_split_parent(mast->orig_r, mast->l->node, mast->r->node, |
| 3445 | &p_slot, split); |
| 3446 | } |
| 3447 | |
| 3448 | /* |
| 3449 | * mas_push_data() - Instead of splitting a node, it is beneficial to push the |
| 3450 | * data to the right or left node if there is room. |
| 3451 | * @mas: The maple state |
| 3452 | * @height: The current height of the maple state |
| 3453 | * @mast: The maple subtree state |
| 3454 | * @left: Push left or not. |
| 3455 | * |
| 3456 | * Keeping the height of the tree low means faster lookups. |
| 3457 | * |
| 3458 | * Return: True if pushed, false otherwise. |
| 3459 | */ |
| 3460 | static inline bool mas_push_data(struct ma_state *mas, int height, |
| 3461 | struct maple_subtree_state *mast, bool left) |
| 3462 | { |
| 3463 | unsigned char slot_total = mast->bn->b_end; |
| 3464 | unsigned char end, space, split; |
| 3465 | |
| 3466 | MA_STATE(tmp_mas, mas->tree, mas->index, mas->last); |
| 3467 | tmp_mas = *mas; |
| 3468 | tmp_mas.depth = mast->l->depth; |
| 3469 | |
| 3470 | if (left && !mas_prev_sibling(&tmp_mas)) |
| 3471 | return false; |
| 3472 | else if (!left && !mas_next_sibling(&tmp_mas)) |
| 3473 | return false; |
| 3474 | |
| 3475 | end = mas_data_end(&tmp_mas); |
| 3476 | slot_total += end; |
| 3477 | space = 2 * mt_slot_count(mas->node) - 2; |
| 3478 | /* -2 instead of -1 to ensure there isn't a triple split */ |
| 3479 | if (ma_is_leaf(mast->bn->type)) |
| 3480 | space--; |
| 3481 | |
| 3482 | if (mas->max == ULONG_MAX) |
| 3483 | space--; |
| 3484 | |
| 3485 | if (slot_total >= space) |
| 3486 | return false; |
| 3487 | |
| 3488 | /* Get the data; Fill mast->bn */ |
| 3489 | mast->bn->b_end++; |
| 3490 | if (left) { |
| 3491 | mab_shift_right(mast->bn, end + 1); |
| 3492 | mas_mab_cp(&tmp_mas, 0, end, mast->bn, 0); |
| 3493 | mast->bn->b_end = slot_total + 1; |
| 3494 | } else { |
| 3495 | mas_mab_cp(&tmp_mas, 0, end, mast->bn, mast->bn->b_end); |
| 3496 | } |
| 3497 | |
| 3498 | /* Configure mast for splitting of mast->bn */ |
| 3499 | split = mt_slots[mast->bn->type] - 2; |
| 3500 | if (left) { |
| 3501 | /* Switch mas to prev node */ |
| 3502 | mat_add(mast->free, mas->node); |
| 3503 | *mas = tmp_mas; |
| 3504 | /* Start using mast->l for the left side. */ |
| 3505 | tmp_mas.node = mast->l->node; |
| 3506 | *mast->l = tmp_mas; |
| 3507 | } else { |
| 3508 | mat_add(mast->free, tmp_mas.node); |
| 3509 | tmp_mas.node = mast->r->node; |
| 3510 | *mast->r = tmp_mas; |
| 3511 | split = slot_total - split; |
| 3512 | } |
| 3513 | split = mab_no_null_split(mast->bn, split, mt_slots[mast->bn->type]); |
| 3514 | /* Update parent slot for split calculation. */ |
| 3515 | if (left) |
| 3516 | mast->orig_l->offset += end + 1; |
| 3517 | |
| 3518 | mast_split_data(mast, mas, split); |
| 3519 | mast_fill_bnode(mast, mas, 2); |
| 3520 | mas_split_final_node(mast, mas, height + 1); |
| 3521 | return true; |
| 3522 | } |
| 3523 | |
| 3524 | /* |
| 3525 | * mas_split() - Split data that is too big for one node into two. |
| 3526 | * @mas: The maple state |
| 3527 | * @b_node: The maple big node |
| 3528 | * Return: 1 on success, 0 on failure. |
| 3529 | */ |
| 3530 | static int mas_split(struct ma_state *mas, struct maple_big_node *b_node) |
| 3531 | { |
| 3532 | struct maple_subtree_state mast; |
| 3533 | int height = 0; |
| 3534 | unsigned char mid_split, split = 0; |
| 3535 | |
| 3536 | /* |
| 3537 | * Splitting is handled differently from any other B-tree; the Maple |
| 3538 | * Tree splits upwards. Splitting up means that the split operation |
| 3539 | * occurs when the walk of the tree hits the leaves and not on the way |
| 3540 | * down. The reason for splitting up is that it is impossible to know |
| 3541 | * how much space will be needed until the leaf is (or leaves are) |
| 3542 | * reached. Since overwriting data is allowed and a range could |
| 3543 | * overwrite more than one range or result in changing one entry into 3 |
| 3544 | * entries, it is impossible to know if a split is required until the |
| 3545 | * data is examined. |
| 3546 | * |
| 3547 | * Splitting is a balancing act between keeping allocations to a minimum |
| 3548 | * and avoiding a 'jitter' event where a tree is expanded to make room |
| 3549 | * for an entry followed by a contraction when the entry is removed. To |
| 3550 | * accomplish the balance, there are empty slots remaining in both left |
| 3551 | * and right nodes after a split. |
| 3552 | */ |
| 3553 | MA_STATE(l_mas, mas->tree, mas->index, mas->last); |
| 3554 | MA_STATE(r_mas, mas->tree, mas->index, mas->last); |
| 3555 | MA_STATE(prev_l_mas, mas->tree, mas->index, mas->last); |
| 3556 | MA_STATE(prev_r_mas, mas->tree, mas->index, mas->last); |
| 3557 | MA_TOPIARY(mat, mas->tree); |
| 3558 | |
| 3559 | trace_ma_op(__func__, mas); |
| 3560 | mas->depth = mas_mt_height(mas); |
| 3561 | /* Allocation failures will happen early. */ |
| 3562 | mas_node_count(mas, 1 + mas->depth * 2); |
| 3563 | if (mas_is_err(mas)) |
| 3564 | return 0; |
| 3565 | |
| 3566 | mast.l = &l_mas; |
| 3567 | mast.r = &r_mas; |
| 3568 | mast.orig_l = &prev_l_mas; |
| 3569 | mast.orig_r = &prev_r_mas; |
| 3570 | mast.free = &mat; |
| 3571 | mast.bn = b_node; |
| 3572 | |
| 3573 | while (height++ <= mas->depth) { |
| 3574 | if (mt_slots[b_node->type] > b_node->b_end) { |
| 3575 | mas_split_final_node(&mast, mas, height); |
| 3576 | break; |
| 3577 | } |
| 3578 | |
| 3579 | l_mas = r_mas = *mas; |
| 3580 | l_mas.node = mas_new_ma_node(mas, b_node); |
| 3581 | r_mas.node = mas_new_ma_node(mas, b_node); |
| 3582 | /* |
| 3583 | * Another way that 'jitter' is avoided is to terminate a split up early if the |
| 3584 | * left or right node has space to spare. This is referred to as "pushing left" |
| 3585 | * or "pushing right" and is similar to the B* tree, except the nodes left or |
| 3586 | * right can rarely be reused due to RCU, but the ripple upwards is halted which |
| 3587 | * is a significant savings. |
| 3588 | */ |
| 3589 | /* Try to push left. */ |
| 3590 | if (mas_push_data(mas, height, &mast, true)) |
| 3591 | break; |
| 3592 | |
| 3593 | /* Try to push right. */ |
| 3594 | if (mas_push_data(mas, height, &mast, false)) |
| 3595 | break; |
| 3596 | |
| 3597 | split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min); |
| 3598 | mast_split_data(&mast, mas, split); |
| 3599 | /* |
| 3600 | * Usually correct, mab_mas_cp in the above call overwrites |
| 3601 | * r->max. |
| 3602 | */ |
| 3603 | mast.r->max = mas->max; |
| 3604 | mast_fill_bnode(&mast, mas, 1); |
| 3605 | prev_l_mas = *mast.l; |
| 3606 | prev_r_mas = *mast.r; |
| 3607 | } |
| 3608 | |
| 3609 | /* Set the original node as dead */ |
| 3610 | mat_add(mast.free, mas->node); |
| 3611 | mas->node = l_mas.node; |
| 3612 | mas_wmb_replace(mas, mast.free, NULL); |
| 3613 | mtree_range_walk(mas); |
| 3614 | return 1; |
| 3615 | } |
| 3616 | |
| 3617 | /* |
| 3618 | * mas_reuse_node() - Reuse the node to store the data. |
| 3619 | * @wr_mas: The maple write state |
| 3620 | * @bn: The maple big node |
| 3621 | * @end: The end of the data. |
| 3622 | * |
| 3623 | * Will always return false in RCU mode. |
| 3624 | * |
| 3625 | * Return: True if node was reused, false otherwise. |
| 3626 | */ |
| 3627 | static inline bool mas_reuse_node(struct ma_wr_state *wr_mas, |
| 3628 | struct maple_big_node *bn, unsigned char end) |
| 3629 | { |
| 3630 | /* Need to be rcu safe. */ |
| 3631 | if (mt_in_rcu(wr_mas->mas->tree)) |
| 3632 | return false; |
| 3633 | |
| 3634 | if (end > bn->b_end) { |
| 3635 | int clear = mt_slots[wr_mas->type] - bn->b_end; |
| 3636 | |
| 3637 | memset(wr_mas->slots + bn->b_end, 0, sizeof(void *) * clear--); |
| 3638 | memset(wr_mas->pivots + bn->b_end, 0, sizeof(void *) * clear); |
| 3639 | } |
| 3640 | mab_mas_cp(bn, 0, bn->b_end, wr_mas->mas, false); |
| 3641 | return true; |
| 3642 | } |
| 3643 | |
| 3644 | /* |
| 3645 | * mas_commit_b_node() - Commit the big node into the tree. |
| 3646 | * @wr_mas: The maple write state |
| 3647 | * @b_node: The maple big node |
| 3648 | * @end: The end of the data. |
| 3649 | */ |
| 3650 | static noinline_for_kasan int mas_commit_b_node(struct ma_wr_state *wr_mas, |
| 3651 | struct maple_big_node *b_node, unsigned char end) |
| 3652 | { |
| 3653 | struct maple_node *node; |
| 3654 | unsigned char b_end = b_node->b_end; |
| 3655 | enum maple_type b_type = b_node->type; |
| 3656 | |
| 3657 | if ((b_end < mt_min_slots[b_type]) && |
| 3658 | (!mte_is_root(wr_mas->mas->node)) && |
| 3659 | (mas_mt_height(wr_mas->mas) > 1)) |
| 3660 | return mas_rebalance(wr_mas->mas, b_node); |
| 3661 | |
| 3662 | if (b_end >= mt_slots[b_type]) |
| 3663 | return mas_split(wr_mas->mas, b_node); |
| 3664 | |
| 3665 | if (mas_reuse_node(wr_mas, b_node, end)) |
| 3666 | goto reuse_node; |
| 3667 | |
| 3668 | mas_node_count(wr_mas->mas, 1); |
| 3669 | if (mas_is_err(wr_mas->mas)) |
| 3670 | return 0; |
| 3671 | |
| 3672 | node = mas_pop_node(wr_mas->mas); |
| 3673 | node->parent = mas_mn(wr_mas->mas)->parent; |
| 3674 | wr_mas->mas->node = mt_mk_node(node, b_type); |
| 3675 | mab_mas_cp(b_node, 0, b_end, wr_mas->mas, false); |
| 3676 | mas_replace(wr_mas->mas, false); |
| 3677 | reuse_node: |
| 3678 | mas_update_gap(wr_mas->mas); |
| 3679 | return 1; |
| 3680 | } |
| 3681 | |
| 3682 | /* |
| 3683 | * mas_root_expand() - Expand a root to a node |
| 3684 | * @mas: The maple state |
| 3685 | * @entry: The entry to store into the tree |
| 3686 | */ |
| 3687 | static inline int mas_root_expand(struct ma_state *mas, void *entry) |
| 3688 | { |
| 3689 | void *contents = mas_root_locked(mas); |
| 3690 | enum maple_type type = maple_leaf_64; |
| 3691 | struct maple_node *node; |
| 3692 | void __rcu **slots; |
| 3693 | unsigned long *pivots; |
| 3694 | int slot = 0; |
| 3695 | |
| 3696 | mas_node_count(mas, 1); |
| 3697 | if (unlikely(mas_is_err(mas))) |
| 3698 | return 0; |
| 3699 | |
| 3700 | node = mas_pop_node(mas); |
| 3701 | pivots = ma_pivots(node, type); |
| 3702 | slots = ma_slots(node, type); |
| 3703 | node->parent = ma_parent_ptr( |
| 3704 | ((unsigned long)mas->tree | MA_ROOT_PARENT)); |
| 3705 | mas->node = mt_mk_node(node, type); |
| 3706 | |
| 3707 | if (mas->index) { |
| 3708 | if (contents) { |
| 3709 | rcu_assign_pointer(slots[slot], contents); |
| 3710 | if (likely(mas->index > 1)) |
| 3711 | slot++; |
| 3712 | } |
| 3713 | pivots[slot++] = mas->index - 1; |
| 3714 | } |
| 3715 | |
| 3716 | rcu_assign_pointer(slots[slot], entry); |
| 3717 | mas->offset = slot; |
| 3718 | pivots[slot] = mas->last; |
| 3719 | if (mas->last != ULONG_MAX) |
| 3720 | slot++; |
| 3721 | mas->depth = 1; |
| 3722 | mas_set_height(mas); |
| 3723 | ma_set_meta(node, maple_leaf_64, 0, slot); |
| 3724 | /* swap the new root into the tree */ |
| 3725 | rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node)); |
| 3726 | return slot; |
| 3727 | } |
| 3728 | |
| 3729 | static inline void mas_store_root(struct ma_state *mas, void *entry) |
| 3730 | { |
| 3731 | if (likely((mas->last != 0) || (mas->index != 0))) |
| 3732 | mas_root_expand(mas, entry); |
| 3733 | else if (((unsigned long) (entry) & 3) == 2) |
| 3734 | mas_root_expand(mas, entry); |
| 3735 | else { |
| 3736 | rcu_assign_pointer(mas->tree->ma_root, entry); |
| 3737 | mas->node = MAS_START; |
| 3738 | } |
| 3739 | } |
| 3740 | |
| 3741 | /* |
| 3742 | * mas_is_span_wr() - Check if the write needs to be treated as a write that |
| 3743 | * spans the node. |
| 3744 | * @mas: The maple state |
| 3745 | * @piv: The pivot value being written |
| 3746 | * @type: The maple node type |
| 3747 | * @entry: The data to write |
| 3748 | * |
| 3749 | * Spanning writes are writes that start in one node and end in another OR if |
| 3750 | * the write of a %NULL will cause the node to end with a %NULL. |
| 3751 | * |
| 3752 | * Return: True if this is a spanning write, false otherwise. |
| 3753 | */ |
| 3754 | static bool mas_is_span_wr(struct ma_wr_state *wr_mas) |
| 3755 | { |
| 3756 | unsigned long max; |
| 3757 | unsigned long last = wr_mas->mas->last; |
| 3758 | unsigned long piv = wr_mas->r_max; |
| 3759 | enum maple_type type = wr_mas->type; |
| 3760 | void *entry = wr_mas->entry; |
| 3761 | |
| 3762 | /* Contained in this pivot */ |
| 3763 | if (piv > last) |
| 3764 | return false; |
| 3765 | |
| 3766 | max = wr_mas->mas->max; |
| 3767 | if (unlikely(ma_is_leaf(type))) { |
| 3768 | /* Fits in the node, but may span slots. */ |
| 3769 | if (last < max) |
| 3770 | return false; |
| 3771 | |
| 3772 | /* Writes to the end of the node but not null. */ |
| 3773 | if ((last == max) && entry) |
| 3774 | return false; |
| 3775 | |
| 3776 | /* |
| 3777 | * Writing ULONG_MAX is not a spanning write regardless of the |
| 3778 | * value being written as long as the range fits in the node. |
| 3779 | */ |
| 3780 | if ((last == ULONG_MAX) && (last == max)) |
| 3781 | return false; |
| 3782 | } else if (piv == last) { |
| 3783 | if (entry) |
| 3784 | return false; |
| 3785 | |
| 3786 | /* Detect spanning store wr walk */ |
| 3787 | if (last == ULONG_MAX) |
| 3788 | return false; |
| 3789 | } |
| 3790 | |
| 3791 | trace_ma_write(__func__, wr_mas->mas, piv, entry); |
| 3792 | |
| 3793 | return true; |
| 3794 | } |
| 3795 | |
| 3796 | static inline void mas_wr_walk_descend(struct ma_wr_state *wr_mas) |
| 3797 | { |
| 3798 | wr_mas->type = mte_node_type(wr_mas->mas->node); |
| 3799 | mas_wr_node_walk(wr_mas); |
| 3800 | wr_mas->slots = ma_slots(wr_mas->node, wr_mas->type); |
| 3801 | } |
| 3802 | |
| 3803 | static inline void mas_wr_walk_traverse(struct ma_wr_state *wr_mas) |
| 3804 | { |
| 3805 | wr_mas->mas->max = wr_mas->r_max; |
| 3806 | wr_mas->mas->min = wr_mas->r_min; |
| 3807 | wr_mas->mas->node = wr_mas->content; |
| 3808 | wr_mas->mas->offset = 0; |
| 3809 | wr_mas->mas->depth++; |
| 3810 | } |
| 3811 | /* |
| 3812 | * mas_wr_walk() - Walk the tree for a write. |
| 3813 | * @wr_mas: The maple write state |
| 3814 | * |
| 3815 | * Uses mas_slot_locked() and does not need to worry about dead nodes. |
| 3816 | * |
| 3817 | * Return: True if it's contained in a node, false on spanning write. |
| 3818 | */ |
| 3819 | static bool mas_wr_walk(struct ma_wr_state *wr_mas) |
| 3820 | { |
| 3821 | struct ma_state *mas = wr_mas->mas; |
| 3822 | |
| 3823 | while (true) { |
| 3824 | mas_wr_walk_descend(wr_mas); |
| 3825 | if (unlikely(mas_is_span_wr(wr_mas))) |
| 3826 | return false; |
| 3827 | |
| 3828 | wr_mas->content = mas_slot_locked(mas, wr_mas->slots, |
| 3829 | mas->offset); |
| 3830 | if (ma_is_leaf(wr_mas->type)) |
| 3831 | return true; |
| 3832 | |
| 3833 | mas_wr_walk_traverse(wr_mas); |
| 3834 | } |
| 3835 | |
| 3836 | return true; |
| 3837 | } |
| 3838 | |
| 3839 | static bool mas_wr_walk_index(struct ma_wr_state *wr_mas) |
| 3840 | { |
| 3841 | struct ma_state *mas = wr_mas->mas; |
| 3842 | |
| 3843 | while (true) { |
| 3844 | mas_wr_walk_descend(wr_mas); |
| 3845 | wr_mas->content = mas_slot_locked(mas, wr_mas->slots, |
| 3846 | mas->offset); |
| 3847 | if (ma_is_leaf(wr_mas->type)) |
| 3848 | return true; |
| 3849 | mas_wr_walk_traverse(wr_mas); |
| 3850 | |
| 3851 | } |
| 3852 | return true; |
| 3853 | } |
| 3854 | /* |
| 3855 | * mas_extend_spanning_null() - Extend a store of a %NULL to include surrounding %NULLs. |
| 3856 | * @l_wr_mas: The left maple write state |
| 3857 | * @r_wr_mas: The right maple write state |
| 3858 | */ |
| 3859 | static inline void mas_extend_spanning_null(struct ma_wr_state *l_wr_mas, |
| 3860 | struct ma_wr_state *r_wr_mas) |
| 3861 | { |
| 3862 | struct ma_state *r_mas = r_wr_mas->mas; |
| 3863 | struct ma_state *l_mas = l_wr_mas->mas; |
| 3864 | unsigned char l_slot; |
| 3865 | |
| 3866 | l_slot = l_mas->offset; |
| 3867 | if (!l_wr_mas->content) |
| 3868 | l_mas->index = l_wr_mas->r_min; |
| 3869 | |
| 3870 | if ((l_mas->index == l_wr_mas->r_min) && |
| 3871 | (l_slot && |
| 3872 | !mas_slot_locked(l_mas, l_wr_mas->slots, l_slot - 1))) { |
| 3873 | if (l_slot > 1) |
| 3874 | l_mas->index = l_wr_mas->pivots[l_slot - 2] + 1; |
| 3875 | else |
| 3876 | l_mas->index = l_mas->min; |
| 3877 | |
| 3878 | l_mas->offset = l_slot - 1; |
| 3879 | } |
| 3880 | |
| 3881 | if (!r_wr_mas->content) { |
| 3882 | if (r_mas->last < r_wr_mas->r_max) |
| 3883 | r_mas->last = r_wr_mas->r_max; |
| 3884 | r_mas->offset++; |
| 3885 | } else if ((r_mas->last == r_wr_mas->r_max) && |
| 3886 | (r_mas->last < r_mas->max) && |
| 3887 | !mas_slot_locked(r_mas, r_wr_mas->slots, r_mas->offset + 1)) { |
| 3888 | r_mas->last = mas_safe_pivot(r_mas, r_wr_mas->pivots, |
| 3889 | r_wr_mas->type, r_mas->offset + 1); |
| 3890 | r_mas->offset++; |
| 3891 | } |
| 3892 | } |
| 3893 | |
| 3894 | static inline void *mas_state_walk(struct ma_state *mas) |
| 3895 | { |
| 3896 | void *entry; |
| 3897 | |
| 3898 | entry = mas_start(mas); |
| 3899 | if (mas_is_none(mas)) |
| 3900 | return NULL; |
| 3901 | |
| 3902 | if (mas_is_ptr(mas)) |
| 3903 | return entry; |
| 3904 | |
| 3905 | return mtree_range_walk(mas); |
| 3906 | } |
| 3907 | |
| 3908 | /* |
| 3909 | * mtree_lookup_walk() - Internal quick lookup that does not keep maple state up |
| 3910 | * to date. |
| 3911 | * |
| 3912 | * @mas: The maple state. |
| 3913 | * |
| 3914 | * Note: Leaves mas in undesirable state. |
| 3915 | * Return: The entry for @mas->index or %NULL on dead node. |
| 3916 | */ |
| 3917 | static inline void *mtree_lookup_walk(struct ma_state *mas) |
| 3918 | { |
| 3919 | unsigned long *pivots; |
| 3920 | unsigned char offset; |
| 3921 | struct maple_node *node; |
| 3922 | struct maple_enode *next; |
| 3923 | enum maple_type type; |
| 3924 | void __rcu **slots; |
| 3925 | unsigned char end; |
| 3926 | unsigned long max; |
| 3927 | |
| 3928 | next = mas->node; |
| 3929 | max = ULONG_MAX; |
| 3930 | do { |
| 3931 | offset = 0; |
| 3932 | node = mte_to_node(next); |
| 3933 | type = mte_node_type(next); |
| 3934 | pivots = ma_pivots(node, type); |
| 3935 | end = ma_data_end(node, type, pivots, max); |
| 3936 | if (unlikely(ma_dead_node(node))) |
| 3937 | goto dead_node; |
| 3938 | do { |
| 3939 | if (pivots[offset] >= mas->index) { |
| 3940 | max = pivots[offset]; |
| 3941 | break; |
| 3942 | } |
| 3943 | } while (++offset < end); |
| 3944 | |
| 3945 | slots = ma_slots(node, type); |
| 3946 | next = mt_slot(mas->tree, slots, offset); |
| 3947 | if (unlikely(ma_dead_node(node))) |
| 3948 | goto dead_node; |
| 3949 | } while (!ma_is_leaf(type)); |
| 3950 | |
| 3951 | return (void *)next; |
| 3952 | |
| 3953 | dead_node: |
| 3954 | mas_reset(mas); |
| 3955 | return NULL; |
| 3956 | } |
| 3957 | |
| 3958 | /* |
| 3959 | * mas_new_root() - Create a new root node that only contains the entry passed |
| 3960 | * in. |
| 3961 | * @mas: The maple state |
| 3962 | * @entry: The entry to store. |
| 3963 | * |
| 3964 | * Only valid when the index == 0 and the last == ULONG_MAX |
| 3965 | * |
| 3966 | * Return 0 on error, 1 on success. |
| 3967 | */ |
| 3968 | static inline int mas_new_root(struct ma_state *mas, void *entry) |
| 3969 | { |
| 3970 | struct maple_enode *root = mas_root_locked(mas); |
| 3971 | enum maple_type type = maple_leaf_64; |
| 3972 | struct maple_node *node; |
| 3973 | void __rcu **slots; |
| 3974 | unsigned long *pivots; |
| 3975 | |
| 3976 | if (!entry && !mas->index && mas->last == ULONG_MAX) { |
| 3977 | mas->depth = 0; |
| 3978 | mas_set_height(mas); |
| 3979 | rcu_assign_pointer(mas->tree->ma_root, entry); |
| 3980 | mas->node = MAS_START; |
| 3981 | goto done; |
| 3982 | } |
| 3983 | |
| 3984 | mas_node_count(mas, 1); |
| 3985 | if (mas_is_err(mas)) |
| 3986 | return 0; |
| 3987 | |
| 3988 | node = mas_pop_node(mas); |
| 3989 | pivots = ma_pivots(node, type); |
| 3990 | slots = ma_slots(node, type); |
| 3991 | node->parent = ma_parent_ptr( |
| 3992 | ((unsigned long)mas->tree | MA_ROOT_PARENT)); |
| 3993 | mas->node = mt_mk_node(node, type); |
| 3994 | rcu_assign_pointer(slots[0], entry); |
| 3995 | pivots[0] = mas->last; |
| 3996 | mas->depth = 1; |
| 3997 | mas_set_height(mas); |
| 3998 | rcu_assign_pointer(mas->tree->ma_root, mte_mk_root(mas->node)); |
| 3999 | |
| 4000 | done: |
| 4001 | if (xa_is_node(root)) |
| 4002 | mte_destroy_walk(root, mas->tree); |
| 4003 | |
| 4004 | return 1; |
| 4005 | } |
| 4006 | /* |
| 4007 | * mas_wr_spanning_store() - Create a subtree with the store operation completed |
| 4008 | * and new nodes where necessary, then place the sub-tree in the actual tree. |
| 4009 | * Note that mas is expected to point to the node which caused the store to |
| 4010 | * span. |
| 4011 | * @wr_mas: The maple write state |
| 4012 | * |
| 4013 | * Return: 0 on error, positive on success. |
| 4014 | */ |
| 4015 | static inline int mas_wr_spanning_store(struct ma_wr_state *wr_mas) |
| 4016 | { |
| 4017 | struct maple_subtree_state mast; |
| 4018 | struct maple_big_node b_node; |
| 4019 | struct ma_state *mas; |
| 4020 | unsigned char height; |
| 4021 | |
| 4022 | /* Left and Right side of spanning store */ |
| 4023 | MA_STATE(l_mas, NULL, 0, 0); |
| 4024 | MA_STATE(r_mas, NULL, 0, 0); |
| 4025 | |
| 4026 | MA_WR_STATE(r_wr_mas, &r_mas, wr_mas->entry); |
| 4027 | MA_WR_STATE(l_wr_mas, &l_mas, wr_mas->entry); |
| 4028 | |
| 4029 | /* |
| 4030 | * A store operation that spans multiple nodes is called a spanning |
| 4031 | * store and is handled early in the store call stack by the function |
| 4032 | * mas_is_span_wr(). When a spanning store is identified, the maple |
| 4033 | * state is duplicated. The first maple state walks the left tree path |
| 4034 | * to ``index``, the duplicate walks the right tree path to ``last``. |
| 4035 | * The data in the two nodes are combined into a single node, two nodes, |
| 4036 | * or possibly three nodes (see the 3-way split above). A ``NULL`` |
| 4037 | * written to the last entry of a node is considered a spanning store as |
| 4038 | * a rebalance is required for the operation to complete and an overflow |
| 4039 | * of data may happen. |
| 4040 | */ |
| 4041 | mas = wr_mas->mas; |
| 4042 | trace_ma_op(__func__, mas); |
| 4043 | |
| 4044 | if (unlikely(!mas->index && mas->last == ULONG_MAX)) |
| 4045 | return mas_new_root(mas, wr_mas->entry); |
| 4046 | /* |
| 4047 | * Node rebalancing may occur due to this store, so there may be three new |
| 4048 | * entries per level plus a new root. |
| 4049 | */ |
| 4050 | height = mas_mt_height(mas); |
| 4051 | mas_node_count(mas, 1 + height * 3); |
| 4052 | if (mas_is_err(mas)) |
| 4053 | return 0; |
| 4054 | |
| 4055 | /* |
| 4056 | * Set up right side. Need to get to the next offset after the spanning |
| 4057 | * store to ensure it's not NULL and to combine both the next node and |
| 4058 | * the node with the start together. |
| 4059 | */ |
| 4060 | r_mas = *mas; |
| 4061 | /* Avoid overflow, walk to next slot in the tree. */ |
| 4062 | if (r_mas.last + 1) |
| 4063 | r_mas.last++; |
| 4064 | |
| 4065 | r_mas.index = r_mas.last; |
| 4066 | mas_wr_walk_index(&r_wr_mas); |
| 4067 | r_mas.last = r_mas.index = mas->last; |
| 4068 | |
| 4069 | /* Set up left side. */ |
| 4070 | l_mas = *mas; |
| 4071 | mas_wr_walk_index(&l_wr_mas); |
| 4072 | |
| 4073 | if (!wr_mas->entry) { |
| 4074 | mas_extend_spanning_null(&l_wr_mas, &r_wr_mas); |
| 4075 | mas->offset = l_mas.offset; |
| 4076 | mas->index = l_mas.index; |
| 4077 | mas->last = l_mas.last = r_mas.last; |
| 4078 | } |
| 4079 | |
| 4080 | /* expanding NULLs may make this cover the entire range */ |
| 4081 | if (!l_mas.index && r_mas.last == ULONG_MAX) { |
| 4082 | mas_set_range(mas, 0, ULONG_MAX); |
| 4083 | return mas_new_root(mas, wr_mas->entry); |
| 4084 | } |
| 4085 | |
| 4086 | memset(&b_node, 0, sizeof(struct maple_big_node)); |
| 4087 | /* Copy l_mas and store the value in b_node. */ |
| 4088 | mas_store_b_node(&l_wr_mas, &b_node, l_wr_mas.node_end); |
| 4089 | /* Copy r_mas into b_node. */ |
| 4090 | if (r_mas.offset <= r_wr_mas.node_end) |
| 4091 | mas_mab_cp(&r_mas, r_mas.offset, r_wr_mas.node_end, |
| 4092 | &b_node, b_node.b_end + 1); |
| 4093 | else |
| 4094 | b_node.b_end++; |
| 4095 | |
| 4096 | /* Stop spanning searches by searching for just index. */ |
| 4097 | l_mas.index = l_mas.last = mas->index; |
| 4098 | |
| 4099 | mast.bn = &b_node; |
| 4100 | mast.orig_l = &l_mas; |
| 4101 | mast.orig_r = &r_mas; |
| 4102 | /* Combine l_mas and r_mas and split them up evenly again. */ |
| 4103 | return mas_spanning_rebalance(mas, &mast, height + 1); |
| 4104 | } |
| 4105 | |
| 4106 | /* |
| 4107 | * mas_wr_node_store() - Attempt to store the value in a node |
| 4108 | * @wr_mas: The maple write state |
| 4109 | * |
| 4110 | * Attempts to reuse the node, but may allocate. |
| 4111 | * |
| 4112 | * Return: True if stored, false otherwise |
| 4113 | */ |
| 4114 | static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas) |
| 4115 | { |
| 4116 | struct ma_state *mas = wr_mas->mas; |
| 4117 | void __rcu **dst_slots; |
| 4118 | unsigned long *dst_pivots; |
| 4119 | unsigned char dst_offset; |
| 4120 | unsigned char new_end = wr_mas->node_end; |
| 4121 | unsigned char offset; |
| 4122 | unsigned char node_slots = mt_slots[wr_mas->type]; |
| 4123 | struct maple_node reuse, *newnode; |
| 4124 | unsigned char copy_size, max_piv = mt_pivots[wr_mas->type]; |
| 4125 | bool in_rcu = mt_in_rcu(mas->tree); |
| 4126 | |
| 4127 | offset = mas->offset; |
| 4128 | if (mas->last == wr_mas->r_max) { |
| 4129 | /* runs right to the end of the node */ |
| 4130 | if (mas->last == mas->max) |
| 4131 | new_end = offset; |
| 4132 | /* don't copy this offset */ |
| 4133 | wr_mas->offset_end++; |
| 4134 | } else if (mas->last < wr_mas->r_max) { |
| 4135 | /* new range ends in this range */ |
| 4136 | if (unlikely(wr_mas->r_max == ULONG_MAX)) |
| 4137 | mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type); |
| 4138 | |
| 4139 | new_end++; |
| 4140 | } else { |
| 4141 | if (wr_mas->end_piv == mas->last) |
| 4142 | wr_mas->offset_end++; |
| 4143 | |
| 4144 | new_end -= wr_mas->offset_end - offset - 1; |
| 4145 | } |
| 4146 | |
| 4147 | /* new range starts within a range */ |
| 4148 | if (wr_mas->r_min < mas->index) |
| 4149 | new_end++; |
| 4150 | |
| 4151 | /* Not enough room */ |
| 4152 | if (new_end >= node_slots) |
| 4153 | return false; |
| 4154 | |
| 4155 | /* Not enough data. */ |
| 4156 | if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) && |
| 4157 | !(mas->mas_flags & MA_STATE_BULK)) |
| 4158 | return false; |
| 4159 | |
| 4160 | /* set up node. */ |
| 4161 | if (in_rcu) { |
| 4162 | mas_node_count(mas, 1); |
| 4163 | if (mas_is_err(mas)) |
| 4164 | return false; |
| 4165 | |
| 4166 | newnode = mas_pop_node(mas); |
| 4167 | } else { |
| 4168 | memset(&reuse, 0, sizeof(struct maple_node)); |
| 4169 | newnode = &reuse; |
| 4170 | } |
| 4171 | |
| 4172 | newnode->parent = mas_mn(mas)->parent; |
| 4173 | dst_pivots = ma_pivots(newnode, wr_mas->type); |
| 4174 | dst_slots = ma_slots(newnode, wr_mas->type); |
| 4175 | /* Copy from start to insert point */ |
| 4176 | memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * (offset + 1)); |
| 4177 | memcpy(dst_slots, wr_mas->slots, sizeof(void *) * (offset + 1)); |
| 4178 | dst_offset = offset; |
| 4179 | |
| 4180 | /* Handle insert of new range starting after old range */ |
| 4181 | if (wr_mas->r_min < mas->index) { |
| 4182 | mas->offset++; |
| 4183 | rcu_assign_pointer(dst_slots[dst_offset], wr_mas->content); |
| 4184 | dst_pivots[dst_offset++] = mas->index - 1; |
| 4185 | } |
| 4186 | |
| 4187 | /* Store the new entry and range end. */ |
| 4188 | if (dst_offset < max_piv) |
| 4189 | dst_pivots[dst_offset] = mas->last; |
| 4190 | mas->offset = dst_offset; |
| 4191 | rcu_assign_pointer(dst_slots[dst_offset], wr_mas->entry); |
| 4192 | |
| 4193 | /* |
| 4194 | * this range wrote to the end of the node or it overwrote the rest of |
| 4195 | * the data |
| 4196 | */ |
| 4197 | if (wr_mas->offset_end > wr_mas->node_end || mas->last >= mas->max) { |
| 4198 | new_end = dst_offset; |
| 4199 | goto done; |
| 4200 | } |
| 4201 | |
| 4202 | dst_offset++; |
| 4203 | /* Copy to the end of node if necessary. */ |
| 4204 | copy_size = wr_mas->node_end - wr_mas->offset_end + 1; |
| 4205 | memcpy(dst_slots + dst_offset, wr_mas->slots + wr_mas->offset_end, |
| 4206 | sizeof(void *) * copy_size); |
| 4207 | if (dst_offset < max_piv) { |
| 4208 | if (copy_size > max_piv - dst_offset) |
| 4209 | copy_size = max_piv - dst_offset; |
| 4210 | |
| 4211 | memcpy(dst_pivots + dst_offset, |
| 4212 | wr_mas->pivots + wr_mas->offset_end, |
| 4213 | sizeof(unsigned long) * copy_size); |
| 4214 | } |
| 4215 | |
| 4216 | if ((wr_mas->node_end == node_slots - 1) && (new_end < node_slots - 1)) |
| 4217 | dst_pivots[new_end] = mas->max; |
| 4218 | |
| 4219 | done: |
| 4220 | mas_leaf_set_meta(mas, newnode, dst_pivots, maple_leaf_64, new_end); |
| 4221 | if (in_rcu) { |
| 4222 | mte_set_node_dead(mas->node); |
| 4223 | mas->node = mt_mk_node(newnode, wr_mas->type); |
| 4224 | mas_replace(mas, false); |
| 4225 | } else { |
| 4226 | memcpy(wr_mas->node, newnode, sizeof(struct maple_node)); |
| 4227 | } |
| 4228 | trace_ma_write(__func__, mas, 0, wr_mas->entry); |
| 4229 | mas_update_gap(mas); |
| 4230 | return true; |
| 4231 | } |
| 4232 | |
| 4233 | /* |
| 4234 | * mas_wr_slot_store: Attempt to store a value in a slot. |
| 4235 | * @wr_mas: the maple write state |
| 4236 | * |
| 4237 | * Return: True if stored, false otherwise |
| 4238 | */ |
| 4239 | static inline bool mas_wr_slot_store(struct ma_wr_state *wr_mas) |
| 4240 | { |
| 4241 | struct ma_state *mas = wr_mas->mas; |
| 4242 | unsigned long lmax; /* Logical max. */ |
| 4243 | unsigned char offset = mas->offset; |
| 4244 | |
| 4245 | if ((wr_mas->r_max > mas->last) && ((wr_mas->r_min != mas->index) || |
| 4246 | (offset != wr_mas->node_end))) |
| 4247 | return false; |
| 4248 | |
| 4249 | if (offset == wr_mas->node_end - 1) |
| 4250 | lmax = mas->max; |
| 4251 | else |
| 4252 | lmax = wr_mas->pivots[offset + 1]; |
| 4253 | |
| 4254 | /* going to overwrite too many slots. */ |
| 4255 | if (lmax < mas->last) |
| 4256 | return false; |
| 4257 | |
| 4258 | if (wr_mas->r_min == mas->index) { |
| 4259 | /* overwriting two or more ranges with one. */ |
| 4260 | if (lmax == mas->last) |
| 4261 | return false; |
| 4262 | |
| 4263 | /* Overwriting all of offset and a portion of offset + 1. */ |
| 4264 | rcu_assign_pointer(wr_mas->slots[offset], wr_mas->entry); |
| 4265 | wr_mas->pivots[offset] = mas->last; |
| 4266 | goto done; |
| 4267 | } |
| 4268 | |
| 4269 | /* Doesn't end on the next range end. */ |
| 4270 | if (lmax != mas->last) |
| 4271 | return false; |
| 4272 | |
| 4273 | /* Overwriting a portion of offset and all of offset + 1 */ |
| 4274 | if ((offset + 1 < mt_pivots[wr_mas->type]) && |
| 4275 | (wr_mas->entry || wr_mas->pivots[offset + 1])) |
| 4276 | wr_mas->pivots[offset + 1] = mas->last; |
| 4277 | |
| 4278 | rcu_assign_pointer(wr_mas->slots[offset + 1], wr_mas->entry); |
| 4279 | wr_mas->pivots[offset] = mas->index - 1; |
| 4280 | mas->offset++; /* Keep mas accurate. */ |
| 4281 | |
| 4282 | done: |
| 4283 | trace_ma_write(__func__, mas, 0, wr_mas->entry); |
| 4284 | mas_update_gap(mas); |
| 4285 | return true; |
| 4286 | } |
| 4287 | |
| 4288 | static inline void mas_wr_end_piv(struct ma_wr_state *wr_mas) |
| 4289 | { |
| 4290 | while ((wr_mas->mas->last > wr_mas->end_piv) && |
| 4291 | (wr_mas->offset_end < wr_mas->node_end)) |
| 4292 | wr_mas->end_piv = wr_mas->pivots[++wr_mas->offset_end]; |
| 4293 | |
| 4294 | if (wr_mas->mas->last > wr_mas->end_piv) |
| 4295 | wr_mas->end_piv = wr_mas->mas->max; |
| 4296 | } |
| 4297 | |
| 4298 | static inline void mas_wr_extend_null(struct ma_wr_state *wr_mas) |
| 4299 | { |
| 4300 | struct ma_state *mas = wr_mas->mas; |
| 4301 | |
| 4302 | if (mas->last < wr_mas->end_piv && !wr_mas->slots[wr_mas->offset_end]) |
| 4303 | mas->last = wr_mas->end_piv; |
| 4304 | |
| 4305 | /* Check next slot(s) if we are overwriting the end */ |
| 4306 | if ((mas->last == wr_mas->end_piv) && |
| 4307 | (wr_mas->node_end != wr_mas->offset_end) && |
| 4308 | !wr_mas->slots[wr_mas->offset_end + 1]) { |
| 4309 | wr_mas->offset_end++; |
| 4310 | if (wr_mas->offset_end == wr_mas->node_end) |
| 4311 | mas->last = mas->max; |
| 4312 | else |
| 4313 | mas->last = wr_mas->pivots[wr_mas->offset_end]; |
| 4314 | wr_mas->end_piv = mas->last; |
| 4315 | } |
| 4316 | |
| 4317 | if (!wr_mas->content) { |
| 4318 | /* If this one is null, the next and prev are not */ |
| 4319 | mas->index = wr_mas->r_min; |
| 4320 | } else { |
| 4321 | /* Check prev slot if we are overwriting the start */ |
| 4322 | if (mas->index == wr_mas->r_min && mas->offset && |
| 4323 | !wr_mas->slots[mas->offset - 1]) { |
| 4324 | mas->offset--; |
| 4325 | wr_mas->r_min = mas->index = |
| 4326 | mas_safe_min(mas, wr_mas->pivots, mas->offset); |
| 4327 | wr_mas->r_max = wr_mas->pivots[mas->offset]; |
| 4328 | } |
| 4329 | } |
| 4330 | } |
| 4331 | |
| 4332 | static inline bool mas_wr_append(struct ma_wr_state *wr_mas) |
| 4333 | { |
| 4334 | unsigned char end = wr_mas->node_end; |
| 4335 | unsigned char new_end = end + 1; |
| 4336 | struct ma_state *mas = wr_mas->mas; |
| 4337 | unsigned char node_pivots = mt_pivots[wr_mas->type]; |
| 4338 | |
| 4339 | if ((mas->index != wr_mas->r_min) && (mas->last == wr_mas->r_max)) { |
| 4340 | if (new_end < node_pivots) |
| 4341 | wr_mas->pivots[new_end] = wr_mas->pivots[end]; |
| 4342 | |
| 4343 | if (new_end < node_pivots) |
| 4344 | ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end); |
| 4345 | |
| 4346 | rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry); |
| 4347 | mas->offset = new_end; |
| 4348 | wr_mas->pivots[end] = mas->index - 1; |
| 4349 | |
| 4350 | return true; |
| 4351 | } |
| 4352 | |
| 4353 | if ((mas->index == wr_mas->r_min) && (mas->last < wr_mas->r_max)) { |
| 4354 | if (new_end < node_pivots) |
| 4355 | wr_mas->pivots[new_end] = wr_mas->pivots[end]; |
| 4356 | |
| 4357 | rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content); |
| 4358 | if (new_end < node_pivots) |
| 4359 | ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end); |
| 4360 | |
| 4361 | wr_mas->pivots[end] = mas->last; |
| 4362 | rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry); |
| 4363 | return true; |
| 4364 | } |
| 4365 | |
| 4366 | return false; |
| 4367 | } |
| 4368 | |
| 4369 | /* |
| 4370 | * mas_wr_bnode() - Slow path for a modification. |
| 4371 | * @wr_mas: The write maple state |
| 4372 | * |
| 4373 | * This is where split, rebalance end up. |
| 4374 | */ |
| 4375 | static void mas_wr_bnode(struct ma_wr_state *wr_mas) |
| 4376 | { |
| 4377 | struct maple_big_node b_node; |
| 4378 | |
| 4379 | trace_ma_write(__func__, wr_mas->mas, 0, wr_mas->entry); |
| 4380 | memset(&b_node, 0, sizeof(struct maple_big_node)); |
| 4381 | mas_store_b_node(wr_mas, &b_node, wr_mas->offset_end); |
| 4382 | mas_commit_b_node(wr_mas, &b_node, wr_mas->node_end); |
| 4383 | } |
| 4384 | |
| 4385 | static inline void mas_wr_modify(struct ma_wr_state *wr_mas) |
| 4386 | { |
| 4387 | unsigned char node_slots; |
| 4388 | unsigned char node_size; |
| 4389 | struct ma_state *mas = wr_mas->mas; |
| 4390 | |
| 4391 | /* Direct replacement */ |
| 4392 | if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last) { |
| 4393 | rcu_assign_pointer(wr_mas->slots[mas->offset], wr_mas->entry); |
| 4394 | if (!!wr_mas->entry ^ !!wr_mas->content) |
| 4395 | mas_update_gap(mas); |
| 4396 | return; |
| 4397 | } |
| 4398 | |
| 4399 | /* Attempt to append */ |
| 4400 | node_slots = mt_slots[wr_mas->type]; |
| 4401 | node_size = wr_mas->node_end - wr_mas->offset_end + mas->offset + 2; |
| 4402 | if (mas->max == ULONG_MAX) |
| 4403 | node_size++; |
| 4404 | |
| 4405 | /* slot and node store will not fit, go to the slow path */ |
| 4406 | if (unlikely(node_size >= node_slots)) |
| 4407 | goto slow_path; |
| 4408 | |
| 4409 | if (wr_mas->entry && (wr_mas->node_end < node_slots - 1) && |
| 4410 | (mas->offset == wr_mas->node_end) && mas_wr_append(wr_mas)) { |
| 4411 | if (!wr_mas->content || !wr_mas->entry) |
| 4412 | mas_update_gap(mas); |
| 4413 | return; |
| 4414 | } |
| 4415 | |
| 4416 | if ((wr_mas->offset_end - mas->offset <= 1) && mas_wr_slot_store(wr_mas)) |
| 4417 | return; |
| 4418 | else if (mas_wr_node_store(wr_mas)) |
| 4419 | return; |
| 4420 | |
| 4421 | if (mas_is_err(mas)) |
| 4422 | return; |
| 4423 | |
| 4424 | slow_path: |
| 4425 | mas_wr_bnode(wr_mas); |
| 4426 | } |
| 4427 | |
| 4428 | /* |
| 4429 | * mas_wr_store_entry() - Internal call to store a value |
| 4430 | * @mas: The maple state |
| 4431 | * @entry: The entry to store. |
| 4432 | * |
| 4433 | * Return: The contents that was stored at the index. |
| 4434 | */ |
| 4435 | static inline void *mas_wr_store_entry(struct ma_wr_state *wr_mas) |
| 4436 | { |
| 4437 | struct ma_state *mas = wr_mas->mas; |
| 4438 | |
| 4439 | wr_mas->content = mas_start(mas); |
| 4440 | if (mas_is_none(mas) || mas_is_ptr(mas)) { |
| 4441 | mas_store_root(mas, wr_mas->entry); |
| 4442 | return wr_mas->content; |
| 4443 | } |
| 4444 | |
| 4445 | if (unlikely(!mas_wr_walk(wr_mas))) { |
| 4446 | mas_wr_spanning_store(wr_mas); |
| 4447 | return wr_mas->content; |
| 4448 | } |
| 4449 | |
| 4450 | /* At this point, we are at the leaf node that needs to be altered. */ |
| 4451 | wr_mas->end_piv = wr_mas->r_max; |
| 4452 | mas_wr_end_piv(wr_mas); |
| 4453 | |
| 4454 | if (!wr_mas->entry) |
| 4455 | mas_wr_extend_null(wr_mas); |
| 4456 | |
| 4457 | /* New root for a single pointer */ |
| 4458 | if (unlikely(!mas->index && mas->last == ULONG_MAX)) { |
| 4459 | mas_new_root(mas, wr_mas->entry); |
| 4460 | return wr_mas->content; |
| 4461 | } |
| 4462 | |
| 4463 | mas_wr_modify(wr_mas); |
| 4464 | return wr_mas->content; |
| 4465 | } |
| 4466 | |
| 4467 | /** |
| 4468 | * mas_insert() - Internal call to insert a value |
| 4469 | * @mas: The maple state |
| 4470 | * @entry: The entry to store |
| 4471 | * |
| 4472 | * Return: %NULL or the contents that already exists at the requested index |
| 4473 | * otherwise. The maple state needs to be checked for error conditions. |
| 4474 | */ |
| 4475 | static inline void *mas_insert(struct ma_state *mas, void *entry) |
| 4476 | { |
| 4477 | MA_WR_STATE(wr_mas, mas, entry); |
| 4478 | |
| 4479 | /* |
| 4480 | * Inserting a new range inserts either 0, 1, or 2 pivots within the |
| 4481 | * tree. If the insert fits exactly into an existing gap with a value |
| 4482 | * of NULL, then the slot only needs to be written with the new value. |
| 4483 | * If the range being inserted is adjacent to another range, then only a |
| 4484 | * single pivot needs to be inserted (as well as writing the entry). If |
| 4485 | * the new range is within a gap but does not touch any other ranges, |
| 4486 | * then two pivots need to be inserted: the start - 1, and the end. As |
| 4487 | * usual, the entry must be written. Most operations require a new node |
| 4488 | * to be allocated and replace an existing node to ensure RCU safety, |
| 4489 | * when in RCU mode. The exception to requiring a newly allocated node |
| 4490 | * is when inserting at the end of a node (appending). When done |
| 4491 | * carefully, appending can reuse the node in place. |
| 4492 | */ |
| 4493 | wr_mas.content = mas_start(mas); |
| 4494 | if (wr_mas.content) |
| 4495 | goto exists; |
| 4496 | |
| 4497 | if (mas_is_none(mas) || mas_is_ptr(mas)) { |
| 4498 | mas_store_root(mas, entry); |
| 4499 | return NULL; |
| 4500 | } |
| 4501 | |
| 4502 | /* spanning writes always overwrite something */ |
| 4503 | if (!mas_wr_walk(&wr_mas)) |
| 4504 | goto exists; |
| 4505 | |
| 4506 | /* At this point, we are at the leaf node that needs to be altered. */ |
| 4507 | wr_mas.offset_end = mas->offset; |
| 4508 | wr_mas.end_piv = wr_mas.r_max; |
| 4509 | |
| 4510 | if (wr_mas.content || (mas->last > wr_mas.r_max)) |
| 4511 | goto exists; |
| 4512 | |
| 4513 | if (!entry) |
| 4514 | return NULL; |
| 4515 | |
| 4516 | mas_wr_modify(&wr_mas); |
| 4517 | return wr_mas.content; |
| 4518 | |
| 4519 | exists: |
| 4520 | mas_set_err(mas, -EEXIST); |
| 4521 | return wr_mas.content; |
| 4522 | |
| 4523 | } |
| 4524 | |
| 4525 | /* |
| 4526 | * mas_prev_node() - Find the prev non-null entry at the same level in the |
| 4527 | * tree. The prev value will be mas->node[mas->offset] or MAS_NONE. |
| 4528 | * @mas: The maple state |
| 4529 | * @min: The lower limit to search |
| 4530 | * |
| 4531 | * The prev node value will be mas->node[mas->offset] or MAS_NONE. |
| 4532 | * Return: 1 if the node is dead, 0 otherwise. |
| 4533 | */ |
| 4534 | static inline int mas_prev_node(struct ma_state *mas, unsigned long min) |
| 4535 | { |
| 4536 | enum maple_type mt; |
| 4537 | int offset, level; |
| 4538 | void __rcu **slots; |
| 4539 | struct maple_node *node; |
| 4540 | struct maple_enode *enode; |
| 4541 | unsigned long *pivots; |
| 4542 | |
| 4543 | if (mas_is_none(mas)) |
| 4544 | return 0; |
| 4545 | |
| 4546 | level = 0; |
| 4547 | do { |
| 4548 | node = mas_mn(mas); |
| 4549 | if (ma_is_root(node)) |
| 4550 | goto no_entry; |
| 4551 | |
| 4552 | /* Walk up. */ |
| 4553 | if (unlikely(mas_ascend(mas))) |
| 4554 | return 1; |
| 4555 | offset = mas->offset; |
| 4556 | level++; |
| 4557 | } while (!offset); |
| 4558 | |
| 4559 | offset--; |
| 4560 | mt = mte_node_type(mas->node); |
| 4561 | node = mas_mn(mas); |
| 4562 | slots = ma_slots(node, mt); |
| 4563 | pivots = ma_pivots(node, mt); |
| 4564 | if (unlikely(ma_dead_node(node))) |
| 4565 | return 1; |
| 4566 | |
| 4567 | mas->max = pivots[offset]; |
| 4568 | if (offset) |
| 4569 | mas->min = pivots[offset - 1] + 1; |
| 4570 | if (unlikely(ma_dead_node(node))) |
| 4571 | return 1; |
| 4572 | |
| 4573 | if (mas->max < min) |
| 4574 | goto no_entry_min; |
| 4575 | |
| 4576 | while (level > 1) { |
| 4577 | level--; |
| 4578 | enode = mas_slot(mas, slots, offset); |
| 4579 | if (unlikely(ma_dead_node(node))) |
| 4580 | return 1; |
| 4581 | |
| 4582 | mas->node = enode; |
| 4583 | mt = mte_node_type(mas->node); |
| 4584 | node = mas_mn(mas); |
| 4585 | slots = ma_slots(node, mt); |
| 4586 | pivots = ma_pivots(node, mt); |
| 4587 | offset = ma_data_end(node, mt, pivots, mas->max); |
| 4588 | if (unlikely(ma_dead_node(node))) |
| 4589 | return 1; |
| 4590 | |
| 4591 | if (offset) |
| 4592 | mas->min = pivots[offset - 1] + 1; |
| 4593 | |
| 4594 | if (offset < mt_pivots[mt]) |
| 4595 | mas->max = pivots[offset]; |
| 4596 | |
| 4597 | if (mas->max < min) |
| 4598 | goto no_entry; |
| 4599 | } |
| 4600 | |
| 4601 | mas->node = mas_slot(mas, slots, offset); |
| 4602 | if (unlikely(ma_dead_node(node))) |
| 4603 | return 1; |
| 4604 | |
| 4605 | mas->offset = mas_data_end(mas); |
| 4606 | if (unlikely(mte_dead_node(mas->node))) |
| 4607 | return 1; |
| 4608 | |
| 4609 | return 0; |
| 4610 | |
| 4611 | no_entry_min: |
| 4612 | mas->offset = offset; |
| 4613 | if (offset) |
| 4614 | mas->min = pivots[offset - 1] + 1; |
| 4615 | no_entry: |
| 4616 | if (unlikely(ma_dead_node(node))) |
| 4617 | return 1; |
| 4618 | |
| 4619 | mas->node = MAS_NONE; |
| 4620 | return 0; |
| 4621 | } |
| 4622 | |
| 4623 | /* |
| 4624 | * mas_next_node() - Get the next node at the same level in the tree. |
| 4625 | * @mas: The maple state |
| 4626 | * @max: The maximum pivot value to check. |
| 4627 | * |
| 4628 | * The next value will be mas->node[mas->offset] or MAS_NONE. |
| 4629 | * Return: 1 on dead node, 0 otherwise. |
| 4630 | */ |
| 4631 | static inline int mas_next_node(struct ma_state *mas, struct maple_node *node, |
| 4632 | unsigned long max) |
| 4633 | { |
| 4634 | unsigned long min, pivot; |
| 4635 | unsigned long *pivots; |
| 4636 | struct maple_enode *enode; |
| 4637 | int level = 0; |
| 4638 | unsigned char offset; |
| 4639 | unsigned char node_end; |
| 4640 | enum maple_type mt; |
| 4641 | void __rcu **slots; |
| 4642 | |
| 4643 | if (mas->max >= max) |
| 4644 | goto no_entry; |
| 4645 | |
| 4646 | level = 0; |
| 4647 | do { |
| 4648 | if (ma_is_root(node)) |
| 4649 | goto no_entry; |
| 4650 | |
| 4651 | min = mas->max + 1; |
| 4652 | if (min > max) |
| 4653 | goto no_entry; |
| 4654 | |
| 4655 | if (unlikely(mas_ascend(mas))) |
| 4656 | return 1; |
| 4657 | |
| 4658 | offset = mas->offset; |
| 4659 | level++; |
| 4660 | node = mas_mn(mas); |
| 4661 | mt = mte_node_type(mas->node); |
| 4662 | pivots = ma_pivots(node, mt); |
| 4663 | node_end = ma_data_end(node, mt, pivots, mas->max); |
| 4664 | if (unlikely(ma_dead_node(node))) |
| 4665 | return 1; |
| 4666 | |
| 4667 | } while (unlikely(offset == node_end)); |
| 4668 | |
| 4669 | slots = ma_slots(node, mt); |
| 4670 | pivot = mas_safe_pivot(mas, pivots, ++offset, mt); |
| 4671 | while (unlikely(level > 1)) { |
| 4672 | /* Descend, if necessary */ |
| 4673 | enode = mas_slot(mas, slots, offset); |
| 4674 | if (unlikely(ma_dead_node(node))) |
| 4675 | return 1; |
| 4676 | |
| 4677 | mas->node = enode; |
| 4678 | level--; |
| 4679 | node = mas_mn(mas); |
| 4680 | mt = mte_node_type(mas->node); |
| 4681 | slots = ma_slots(node, mt); |
| 4682 | pivots = ma_pivots(node, mt); |
| 4683 | if (unlikely(ma_dead_node(node))) |
| 4684 | return 1; |
| 4685 | |
| 4686 | offset = 0; |
| 4687 | pivot = pivots[0]; |
| 4688 | } |
| 4689 | |
| 4690 | enode = mas_slot(mas, slots, offset); |
| 4691 | if (unlikely(ma_dead_node(node))) |
| 4692 | return 1; |
| 4693 | |
| 4694 | mas->node = enode; |
| 4695 | mas->min = min; |
| 4696 | mas->max = pivot; |
| 4697 | return 0; |
| 4698 | |
| 4699 | no_entry: |
| 4700 | if (unlikely(ma_dead_node(node))) |
| 4701 | return 1; |
| 4702 | |
| 4703 | mas->node = MAS_NONE; |
| 4704 | return 0; |
| 4705 | } |
| 4706 | |
| 4707 | /* |
| 4708 | * mas_next_nentry() - Get the next node entry |
| 4709 | * @mas: The maple state |
| 4710 | * @max: The maximum value to check |
| 4711 | * @*range_start: Pointer to store the start of the range. |
| 4712 | * |
| 4713 | * Sets @mas->offset to the offset of the next node entry, @mas->last to the |
| 4714 | * pivot of the entry. |
| 4715 | * |
| 4716 | * Return: The next entry, %NULL otherwise |
| 4717 | */ |
| 4718 | static inline void *mas_next_nentry(struct ma_state *mas, |
| 4719 | struct maple_node *node, unsigned long max, enum maple_type type) |
| 4720 | { |
| 4721 | unsigned char count; |
| 4722 | unsigned long pivot; |
| 4723 | unsigned long *pivots; |
| 4724 | void __rcu **slots; |
| 4725 | void *entry; |
| 4726 | |
| 4727 | if (mas->last == mas->max) { |
| 4728 | mas->index = mas->max; |
| 4729 | return NULL; |
| 4730 | } |
| 4731 | |
| 4732 | slots = ma_slots(node, type); |
| 4733 | pivots = ma_pivots(node, type); |
| 4734 | count = ma_data_end(node, type, pivots, mas->max); |
| 4735 | if (unlikely(ma_dead_node(node))) |
| 4736 | return NULL; |
| 4737 | |
| 4738 | mas->index = mas_safe_min(mas, pivots, mas->offset); |
| 4739 | if (unlikely(ma_dead_node(node))) |
| 4740 | return NULL; |
| 4741 | |
| 4742 | if (mas->index > max) |
| 4743 | return NULL; |
| 4744 | |
| 4745 | if (mas->offset > count) |
| 4746 | return NULL; |
| 4747 | |
| 4748 | while (mas->offset < count) { |
| 4749 | pivot = pivots[mas->offset]; |
| 4750 | entry = mas_slot(mas, slots, mas->offset); |
| 4751 | if (ma_dead_node(node)) |
| 4752 | return NULL; |
| 4753 | |
| 4754 | if (entry) |
| 4755 | goto found; |
| 4756 | |
| 4757 | if (pivot >= max) |
| 4758 | return NULL; |
| 4759 | |
| 4760 | mas->index = pivot + 1; |
| 4761 | mas->offset++; |
| 4762 | } |
| 4763 | |
| 4764 | if (mas->index > mas->max) { |
| 4765 | mas->index = mas->last; |
| 4766 | return NULL; |
| 4767 | } |
| 4768 | |
| 4769 | pivot = mas_safe_pivot(mas, pivots, mas->offset, type); |
| 4770 | entry = mas_slot(mas, slots, mas->offset); |
| 4771 | if (ma_dead_node(node)) |
| 4772 | return NULL; |
| 4773 | |
| 4774 | if (!pivot) |
| 4775 | return NULL; |
| 4776 | |
| 4777 | if (!entry) |
| 4778 | return NULL; |
| 4779 | |
| 4780 | found: |
| 4781 | mas->last = pivot; |
| 4782 | return entry; |
| 4783 | } |
| 4784 | |
| 4785 | static inline void mas_rewalk(struct ma_state *mas, unsigned long index) |
| 4786 | { |
| 4787 | retry: |
| 4788 | mas_set(mas, index); |
| 4789 | mas_state_walk(mas); |
| 4790 | if (mas_is_start(mas)) |
| 4791 | goto retry; |
| 4792 | } |
| 4793 | |
| 4794 | /* |
| 4795 | * mas_next_entry() - Internal function to get the next entry. |
| 4796 | * @mas: The maple state |
| 4797 | * @limit: The maximum range start. |
| 4798 | * |
| 4799 | * Set the @mas->node to the next entry and the range_start to |
| 4800 | * the beginning value for the entry. Does not check beyond @limit. |
| 4801 | * Sets @mas->index and @mas->last to the limit if it is hit. |
| 4802 | * Restarts on dead nodes. |
| 4803 | * |
| 4804 | * Return: the next entry or %NULL. |
| 4805 | */ |
| 4806 | static inline void *mas_next_entry(struct ma_state *mas, unsigned long limit) |
| 4807 | { |
| 4808 | void *entry = NULL; |
| 4809 | struct maple_enode *prev_node; |
| 4810 | struct maple_node *node; |
| 4811 | unsigned char offset; |
| 4812 | unsigned long last; |
| 4813 | enum maple_type mt; |
| 4814 | |
| 4815 | if (mas->index > limit) { |
| 4816 | mas->index = mas->last = limit; |
| 4817 | mas_pause(mas); |
| 4818 | return NULL; |
| 4819 | } |
| 4820 | last = mas->last; |
| 4821 | retry: |
| 4822 | offset = mas->offset; |
| 4823 | prev_node = mas->node; |
| 4824 | node = mas_mn(mas); |
| 4825 | mt = mte_node_type(mas->node); |
| 4826 | mas->offset++; |
| 4827 | if (unlikely(mas->offset >= mt_slots[mt])) { |
| 4828 | mas->offset = mt_slots[mt] - 1; |
| 4829 | goto next_node; |
| 4830 | } |
| 4831 | |
| 4832 | while (!mas_is_none(mas)) { |
| 4833 | entry = mas_next_nentry(mas, node, limit, mt); |
| 4834 | if (unlikely(ma_dead_node(node))) { |
| 4835 | mas_rewalk(mas, last); |
| 4836 | goto retry; |
| 4837 | } |
| 4838 | |
| 4839 | if (likely(entry)) |
| 4840 | return entry; |
| 4841 | |
| 4842 | if (unlikely((mas->index > limit))) |
| 4843 | break; |
| 4844 | |
| 4845 | next_node: |
| 4846 | prev_node = mas->node; |
| 4847 | offset = mas->offset; |
| 4848 | if (unlikely(mas_next_node(mas, node, limit))) { |
| 4849 | mas_rewalk(mas, last); |
| 4850 | goto retry; |
| 4851 | } |
| 4852 | mas->offset = 0; |
| 4853 | node = mas_mn(mas); |
| 4854 | mt = mte_node_type(mas->node); |
| 4855 | } |
| 4856 | |
| 4857 | mas->index = mas->last = limit; |
| 4858 | mas->offset = offset; |
| 4859 | mas->node = prev_node; |
| 4860 | return NULL; |
| 4861 | } |
| 4862 | |
| 4863 | /* |
| 4864 | * mas_prev_nentry() - Get the previous node entry. |
| 4865 | * @mas: The maple state. |
| 4866 | * @limit: The lower limit to check for a value. |
| 4867 | * |
| 4868 | * Return: the entry, %NULL otherwise. |
| 4869 | */ |
| 4870 | static inline void *mas_prev_nentry(struct ma_state *mas, unsigned long limit, |
| 4871 | unsigned long index) |
| 4872 | { |
| 4873 | unsigned long pivot, min; |
| 4874 | unsigned char offset; |
| 4875 | struct maple_node *mn; |
| 4876 | enum maple_type mt; |
| 4877 | unsigned long *pivots; |
| 4878 | void __rcu **slots; |
| 4879 | void *entry; |
| 4880 | |
| 4881 | retry: |
| 4882 | if (!mas->offset) |
| 4883 | return NULL; |
| 4884 | |
| 4885 | mn = mas_mn(mas); |
| 4886 | mt = mte_node_type(mas->node); |
| 4887 | offset = mas->offset - 1; |
| 4888 | if (offset >= mt_slots[mt]) |
| 4889 | offset = mt_slots[mt] - 1; |
| 4890 | |
| 4891 | slots = ma_slots(mn, mt); |
| 4892 | pivots = ma_pivots(mn, mt); |
| 4893 | if (unlikely(ma_dead_node(mn))) { |
| 4894 | mas_rewalk(mas, index); |
| 4895 | goto retry; |
| 4896 | } |
| 4897 | |
| 4898 | if (offset == mt_pivots[mt]) |
| 4899 | pivot = mas->max; |
| 4900 | else |
| 4901 | pivot = pivots[offset]; |
| 4902 | |
| 4903 | if (unlikely(ma_dead_node(mn))) { |
| 4904 | mas_rewalk(mas, index); |
| 4905 | goto retry; |
| 4906 | } |
| 4907 | |
| 4908 | while (offset && ((!mas_slot(mas, slots, offset) && pivot >= limit) || |
| 4909 | !pivot)) |
| 4910 | pivot = pivots[--offset]; |
| 4911 | |
| 4912 | min = mas_safe_min(mas, pivots, offset); |
| 4913 | entry = mas_slot(mas, slots, offset); |
| 4914 | if (unlikely(ma_dead_node(mn))) { |
| 4915 | mas_rewalk(mas, index); |
| 4916 | goto retry; |
| 4917 | } |
| 4918 | |
| 4919 | if (likely(entry)) { |
| 4920 | mas->offset = offset; |
| 4921 | mas->last = pivot; |
| 4922 | mas->index = min; |
| 4923 | } |
| 4924 | return entry; |
| 4925 | } |
| 4926 | |
| 4927 | static inline void *mas_prev_entry(struct ma_state *mas, unsigned long min) |
| 4928 | { |
| 4929 | void *entry; |
| 4930 | |
| 4931 | if (mas->index < min) { |
| 4932 | mas->index = mas->last = min; |
| 4933 | mas->node = MAS_NONE; |
| 4934 | return NULL; |
| 4935 | } |
| 4936 | retry: |
| 4937 | while (likely(!mas_is_none(mas))) { |
| 4938 | entry = mas_prev_nentry(mas, min, mas->index); |
| 4939 | if (unlikely(mas->last < min)) |
| 4940 | goto not_found; |
| 4941 | |
| 4942 | if (likely(entry)) |
| 4943 | return entry; |
| 4944 | |
| 4945 | if (unlikely(mas_prev_node(mas, min))) { |
| 4946 | mas_rewalk(mas, mas->index); |
| 4947 | goto retry; |
| 4948 | } |
| 4949 | |
| 4950 | mas->offset++; |
| 4951 | } |
| 4952 | |
| 4953 | mas->offset--; |
| 4954 | not_found: |
| 4955 | mas->index = mas->last = min; |
| 4956 | return NULL; |
| 4957 | } |
| 4958 | |
| 4959 | /* |
| 4960 | * mas_rev_awalk() - Internal function. Reverse allocation walk. Find the |
| 4961 | * highest gap address of a given size in a given node and descend. |
| 4962 | * @mas: The maple state |
| 4963 | * @size: The needed size. |
| 4964 | * |
| 4965 | * Return: True if found in a leaf, false otherwise. |
| 4966 | * |
| 4967 | */ |
| 4968 | static bool mas_rev_awalk(struct ma_state *mas, unsigned long size, |
| 4969 | unsigned long *gap_min, unsigned long *gap_max) |
| 4970 | { |
| 4971 | enum maple_type type = mte_node_type(mas->node); |
| 4972 | struct maple_node *node = mas_mn(mas); |
| 4973 | unsigned long *pivots, *gaps; |
| 4974 | void __rcu **slots; |
| 4975 | unsigned long gap = 0; |
| 4976 | unsigned long max, min; |
| 4977 | unsigned char offset; |
| 4978 | |
| 4979 | if (unlikely(mas_is_err(mas))) |
| 4980 | return true; |
| 4981 | |
| 4982 | if (ma_is_dense(type)) { |
| 4983 | /* dense nodes. */ |
| 4984 | mas->offset = (unsigned char)(mas->index - mas->min); |
| 4985 | return true; |
| 4986 | } |
| 4987 | |
| 4988 | pivots = ma_pivots(node, type); |
| 4989 | slots = ma_slots(node, type); |
| 4990 | gaps = ma_gaps(node, type); |
| 4991 | offset = mas->offset; |
| 4992 | min = mas_safe_min(mas, pivots, offset); |
| 4993 | /* Skip out of bounds. */ |
| 4994 | while (mas->last < min) |
| 4995 | min = mas_safe_min(mas, pivots, --offset); |
| 4996 | |
| 4997 | max = mas_safe_pivot(mas, pivots, offset, type); |
| 4998 | while (mas->index <= max) { |
| 4999 | gap = 0; |
| 5000 | if (gaps) |
| 5001 | gap = gaps[offset]; |
| 5002 | else if (!mas_slot(mas, slots, offset)) |
| 5003 | gap = max - min + 1; |
| 5004 | |
| 5005 | if (gap) { |
| 5006 | if ((size <= gap) && (size <= mas->last - min + 1)) |
| 5007 | break; |
| 5008 | |
| 5009 | if (!gaps) { |
| 5010 | /* Skip the next slot, it cannot be a gap. */ |
| 5011 | if (offset < 2) |
| 5012 | goto ascend; |
| 5013 | |
| 5014 | offset -= 2; |
| 5015 | max = pivots[offset]; |
| 5016 | min = mas_safe_min(mas, pivots, offset); |
| 5017 | continue; |
| 5018 | } |
| 5019 | } |
| 5020 | |
| 5021 | if (!offset) |
| 5022 | goto ascend; |
| 5023 | |
| 5024 | offset--; |
| 5025 | max = min - 1; |
| 5026 | min = mas_safe_min(mas, pivots, offset); |
| 5027 | } |
| 5028 | |
| 5029 | if (unlikely((mas->index > max) || (size - 1 > max - mas->index))) |
| 5030 | goto no_space; |
| 5031 | |
| 5032 | if (unlikely(ma_is_leaf(type))) { |
| 5033 | mas->offset = offset; |
| 5034 | *gap_min = min; |
| 5035 | *gap_max = min + gap - 1; |
| 5036 | return true; |
| 5037 | } |
| 5038 | |
| 5039 | /* descend, only happens under lock. */ |
| 5040 | mas->node = mas_slot(mas, slots, offset); |
| 5041 | mas->min = min; |
| 5042 | mas->max = max; |
| 5043 | mas->offset = mas_data_end(mas); |
| 5044 | return false; |
| 5045 | |
| 5046 | ascend: |
| 5047 | if (!mte_is_root(mas->node)) |
| 5048 | return false; |
| 5049 | |
| 5050 | no_space: |
| 5051 | mas_set_err(mas, -EBUSY); |
| 5052 | return false; |
| 5053 | } |
| 5054 | |
| 5055 | static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size) |
| 5056 | { |
| 5057 | enum maple_type type = mte_node_type(mas->node); |
| 5058 | unsigned long pivot, min, gap = 0; |
| 5059 | unsigned char offset, data_end; |
| 5060 | unsigned long *gaps, *pivots; |
| 5061 | void __rcu **slots; |
| 5062 | struct maple_node *node; |
| 5063 | bool found = false; |
| 5064 | |
| 5065 | if (ma_is_dense(type)) { |
| 5066 | mas->offset = (unsigned char)(mas->index - mas->min); |
| 5067 | return true; |
| 5068 | } |
| 5069 | |
| 5070 | node = mas_mn(mas); |
| 5071 | pivots = ma_pivots(node, type); |
| 5072 | slots = ma_slots(node, type); |
| 5073 | gaps = ma_gaps(node, type); |
| 5074 | offset = mas->offset; |
| 5075 | min = mas_safe_min(mas, pivots, offset); |
| 5076 | data_end = ma_data_end(node, type, pivots, mas->max); |
| 5077 | for (; offset <= data_end; offset++) { |
| 5078 | pivot = mas_logical_pivot(mas, pivots, offset, type); |
| 5079 | |
| 5080 | /* Not within lower bounds */ |
| 5081 | if (mas->index > pivot) |
| 5082 | goto next_slot; |
| 5083 | |
| 5084 | if (gaps) |
| 5085 | gap = gaps[offset]; |
| 5086 | else if (!mas_slot(mas, slots, offset)) |
| 5087 | gap = min(pivot, mas->last) - max(mas->index, min) + 1; |
| 5088 | else |
| 5089 | goto next_slot; |
| 5090 | |
| 5091 | if (gap >= size) { |
| 5092 | if (ma_is_leaf(type)) { |
| 5093 | found = true; |
| 5094 | goto done; |
| 5095 | } |
| 5096 | if (mas->index <= pivot) { |
| 5097 | mas->node = mas_slot(mas, slots, offset); |
| 5098 | mas->min = min; |
| 5099 | mas->max = pivot; |
| 5100 | offset = 0; |
| 5101 | break; |
| 5102 | } |
| 5103 | } |
| 5104 | next_slot: |
| 5105 | min = pivot + 1; |
| 5106 | if (mas->last <= pivot) { |
| 5107 | mas_set_err(mas, -EBUSY); |
| 5108 | return true; |
| 5109 | } |
| 5110 | } |
| 5111 | |
| 5112 | if (mte_is_root(mas->node)) |
| 5113 | found = true; |
| 5114 | done: |
| 5115 | mas->offset = offset; |
| 5116 | return found; |
| 5117 | } |
| 5118 | |
| 5119 | /** |
| 5120 | * mas_walk() - Search for @mas->index in the tree. |
| 5121 | * @mas: The maple state. |
| 5122 | * |
| 5123 | * mas->index and mas->last will be set to the range if there is a value. If |
| 5124 | * mas->node is MAS_NONE, reset to MAS_START. |
| 5125 | * |
| 5126 | * Return: the entry at the location or %NULL. |
| 5127 | */ |
| 5128 | void *mas_walk(struct ma_state *mas) |
| 5129 | { |
| 5130 | void *entry; |
| 5131 | |
| 5132 | retry: |
| 5133 | entry = mas_state_walk(mas); |
| 5134 | if (mas_is_start(mas)) |
| 5135 | goto retry; |
| 5136 | |
| 5137 | if (mas_is_ptr(mas)) { |
| 5138 | if (!mas->index) { |
| 5139 | mas->last = 0; |
| 5140 | } else { |
| 5141 | mas->index = 1; |
| 5142 | mas->last = ULONG_MAX; |
| 5143 | } |
| 5144 | return entry; |
| 5145 | } |
| 5146 | |
| 5147 | if (mas_is_none(mas)) { |
| 5148 | mas->index = 0; |
| 5149 | mas->last = ULONG_MAX; |
| 5150 | } |
| 5151 | |
| 5152 | return entry; |
| 5153 | } |
| 5154 | EXPORT_SYMBOL_GPL(mas_walk); |
| 5155 | |
| 5156 | static inline bool mas_rewind_node(struct ma_state *mas) |
| 5157 | { |
| 5158 | unsigned char slot; |
| 5159 | |
| 5160 | do { |
| 5161 | if (mte_is_root(mas->node)) { |
| 5162 | slot = mas->offset; |
| 5163 | if (!slot) |
| 5164 | return false; |
| 5165 | } else { |
| 5166 | mas_ascend(mas); |
| 5167 | slot = mas->offset; |
| 5168 | } |
| 5169 | } while (!slot); |
| 5170 | |
| 5171 | mas->offset = --slot; |
| 5172 | return true; |
| 5173 | } |
| 5174 | |
| 5175 | /* |
| 5176 | * mas_skip_node() - Internal function. Skip over a node. |
| 5177 | * @mas: The maple state. |
| 5178 | * |
| 5179 | * Return: true if there is another node, false otherwise. |
| 5180 | */ |
| 5181 | static inline bool mas_skip_node(struct ma_state *mas) |
| 5182 | { |
| 5183 | if (mas_is_err(mas)) |
| 5184 | return false; |
| 5185 | |
| 5186 | do { |
| 5187 | if (mte_is_root(mas->node)) { |
| 5188 | if (mas->offset >= mas_data_end(mas)) { |
| 5189 | mas_set_err(mas, -EBUSY); |
| 5190 | return false; |
| 5191 | } |
| 5192 | } else { |
| 5193 | mas_ascend(mas); |
| 5194 | } |
| 5195 | } while (mas->offset >= mas_data_end(mas)); |
| 5196 | |
| 5197 | mas->offset++; |
| 5198 | return true; |
| 5199 | } |
| 5200 | |
| 5201 | /* |
| 5202 | * mas_awalk() - Allocation walk. Search from low address to high, for a gap of |
| 5203 | * @size |
| 5204 | * @mas: The maple state |
| 5205 | * @size: The size of the gap required |
| 5206 | * |
| 5207 | * Search between @mas->index and @mas->last for a gap of @size. |
| 5208 | */ |
| 5209 | static inline void mas_awalk(struct ma_state *mas, unsigned long size) |
| 5210 | { |
| 5211 | struct maple_enode *last = NULL; |
| 5212 | |
| 5213 | /* |
| 5214 | * There are 4 options: |
| 5215 | * go to child (descend) |
| 5216 | * go back to parent (ascend) |
| 5217 | * no gap found. (return, slot == MAPLE_NODE_SLOTS) |
| 5218 | * found the gap. (return, slot != MAPLE_NODE_SLOTS) |
| 5219 | */ |
| 5220 | while (!mas_is_err(mas) && !mas_anode_descend(mas, size)) { |
| 5221 | if (last == mas->node) |
| 5222 | mas_skip_node(mas); |
| 5223 | else |
| 5224 | last = mas->node; |
| 5225 | } |
| 5226 | } |
| 5227 | |
| 5228 | /* |
| 5229 | * mas_fill_gap() - Fill a located gap with @entry. |
| 5230 | * @mas: The maple state |
| 5231 | * @entry: The value to store |
| 5232 | * @slot: The offset into the node to store the @entry |
| 5233 | * @size: The size of the entry |
| 5234 | * @index: The start location |
| 5235 | */ |
| 5236 | static inline void mas_fill_gap(struct ma_state *mas, void *entry, |
| 5237 | unsigned char slot, unsigned long size, unsigned long *index) |
| 5238 | { |
| 5239 | MA_WR_STATE(wr_mas, mas, entry); |
| 5240 | unsigned char pslot = mte_parent_slot(mas->node); |
| 5241 | struct maple_enode *mn = mas->node; |
| 5242 | unsigned long *pivots; |
| 5243 | enum maple_type ptype; |
| 5244 | /* |
| 5245 | * mas->index is the start address for the search |
| 5246 | * which may no longer be needed. |
| 5247 | * mas->last is the end address for the search |
| 5248 | */ |
| 5249 | |
| 5250 | *index = mas->index; |
| 5251 | mas->last = mas->index + size - 1; |
| 5252 | |
| 5253 | /* |
| 5254 | * It is possible that using mas->max and mas->min to correctly |
| 5255 | * calculate the index and last will cause an issue in the gap |
| 5256 | * calculation, so fix the ma_state here |
| 5257 | */ |
| 5258 | mas_ascend(mas); |
| 5259 | ptype = mte_node_type(mas->node); |
| 5260 | pivots = ma_pivots(mas_mn(mas), ptype); |
| 5261 | mas->max = mas_safe_pivot(mas, pivots, pslot, ptype); |
| 5262 | mas->min = mas_safe_min(mas, pivots, pslot); |
| 5263 | mas->node = mn; |
| 5264 | mas->offset = slot; |
| 5265 | mas_wr_store_entry(&wr_mas); |
| 5266 | } |
| 5267 | |
| 5268 | /* |
| 5269 | * mas_sparse_area() - Internal function. Return upper or lower limit when |
| 5270 | * searching for a gap in an empty tree. |
| 5271 | * @mas: The maple state |
| 5272 | * @min: the minimum range |
| 5273 | * @max: The maximum range |
| 5274 | * @size: The size of the gap |
| 5275 | * @fwd: Searching forward or back |
| 5276 | */ |
| 5277 | static inline void mas_sparse_area(struct ma_state *mas, unsigned long min, |
| 5278 | unsigned long max, unsigned long size, bool fwd) |
| 5279 | { |
| 5280 | unsigned long start = 0; |
| 5281 | |
| 5282 | if (!unlikely(mas_is_none(mas))) |
| 5283 | start++; |
| 5284 | /* mas_is_ptr */ |
| 5285 | |
| 5286 | if (start < min) |
| 5287 | start = min; |
| 5288 | |
| 5289 | if (fwd) { |
| 5290 | mas->index = start; |
| 5291 | mas->last = start + size - 1; |
| 5292 | return; |
| 5293 | } |
| 5294 | |
| 5295 | mas->index = max; |
| 5296 | } |
| 5297 | |
| 5298 | /* |
| 5299 | * mas_empty_area() - Get the lowest address within the range that is |
| 5300 | * sufficient for the size requested. |
| 5301 | * @mas: The maple state |
| 5302 | * @min: The lowest value of the range |
| 5303 | * @max: The highest value of the range |
| 5304 | * @size: The size needed |
| 5305 | */ |
| 5306 | int mas_empty_area(struct ma_state *mas, unsigned long min, |
| 5307 | unsigned long max, unsigned long size) |
| 5308 | { |
| 5309 | unsigned char offset; |
| 5310 | unsigned long *pivots; |
| 5311 | enum maple_type mt; |
| 5312 | |
| 5313 | if (min >= max) |
| 5314 | return -EINVAL; |
| 5315 | |
| 5316 | if (mas_is_start(mas)) |
| 5317 | mas_start(mas); |
| 5318 | else if (mas->offset >= 2) |
| 5319 | mas->offset -= 2; |
| 5320 | else if (!mas_skip_node(mas)) |
| 5321 | return -EBUSY; |
| 5322 | |
| 5323 | /* Empty set */ |
| 5324 | if (mas_is_none(mas) || mas_is_ptr(mas)) { |
| 5325 | mas_sparse_area(mas, min, max, size, true); |
| 5326 | return 0; |
| 5327 | } |
| 5328 | |
| 5329 | /* The start of the window can only be within these values */ |
| 5330 | mas->index = min; |
| 5331 | mas->last = max; |
| 5332 | mas_awalk(mas, size); |
| 5333 | |
| 5334 | if (unlikely(mas_is_err(mas))) |
| 5335 | return xa_err(mas->node); |
| 5336 | |
| 5337 | offset = mas->offset; |
| 5338 | if (unlikely(offset == MAPLE_NODE_SLOTS)) |
| 5339 | return -EBUSY; |
| 5340 | |
| 5341 | mt = mte_node_type(mas->node); |
| 5342 | pivots = ma_pivots(mas_mn(mas), mt); |
| 5343 | if (offset) |
| 5344 | mas->min = pivots[offset - 1] + 1; |
| 5345 | |
| 5346 | if (offset < mt_pivots[mt]) |
| 5347 | mas->max = pivots[offset]; |
| 5348 | |
| 5349 | if (mas->index < mas->min) |
| 5350 | mas->index = mas->min; |
| 5351 | |
| 5352 | mas->last = mas->index + size - 1; |
| 5353 | return 0; |
| 5354 | } |
| 5355 | EXPORT_SYMBOL_GPL(mas_empty_area); |
| 5356 | |
| 5357 | /* |
| 5358 | * mas_empty_area_rev() - Get the highest address within the range that is |
| 5359 | * sufficient for the size requested. |
| 5360 | * @mas: The maple state |
| 5361 | * @min: The lowest value of the range |
| 5362 | * @max: The highest value of the range |
| 5363 | * @size: The size needed |
| 5364 | */ |
| 5365 | int mas_empty_area_rev(struct ma_state *mas, unsigned long min, |
| 5366 | unsigned long max, unsigned long size) |
| 5367 | { |
| 5368 | struct maple_enode *last = mas->node; |
| 5369 | |
| 5370 | if (min >= max) |
| 5371 | return -EINVAL; |
| 5372 | |
| 5373 | if (mas_is_start(mas)) { |
| 5374 | mas_start(mas); |
| 5375 | mas->offset = mas_data_end(mas); |
| 5376 | } else if (mas->offset >= 2) { |
| 5377 | mas->offset -= 2; |
| 5378 | } else if (!mas_rewind_node(mas)) { |
| 5379 | return -EBUSY; |
| 5380 | } |
| 5381 | |
| 5382 | /* Empty set. */ |
| 5383 | if (mas_is_none(mas) || mas_is_ptr(mas)) { |
| 5384 | mas_sparse_area(mas, min, max, size, false); |
| 5385 | return 0; |
| 5386 | } |
| 5387 | |
| 5388 | /* The start of the window can only be within these values. */ |
| 5389 | mas->index = min; |
| 5390 | mas->last = max; |
| 5391 | |
| 5392 | while (!mas_rev_awalk(mas, size, &min, &max)) { |
| 5393 | if (last == mas->node) { |
| 5394 | if (!mas_rewind_node(mas)) |
| 5395 | return -EBUSY; |
| 5396 | } else { |
| 5397 | last = mas->node; |
| 5398 | } |
| 5399 | } |
| 5400 | |
| 5401 | if (mas_is_err(mas)) |
| 5402 | return xa_err(mas->node); |
| 5403 | |
| 5404 | if (unlikely(mas->offset == MAPLE_NODE_SLOTS)) |
| 5405 | return -EBUSY; |
| 5406 | |
| 5407 | /* Trim the upper limit to the max. */ |
| 5408 | if (max <= mas->last) |
| 5409 | mas->last = max; |
| 5410 | |
| 5411 | mas->index = mas->last - size + 1; |
| 5412 | return 0; |
| 5413 | } |
| 5414 | EXPORT_SYMBOL_GPL(mas_empty_area_rev); |
| 5415 | |
| 5416 | static inline int mas_alloc(struct ma_state *mas, void *entry, |
| 5417 | unsigned long size, unsigned long *index) |
| 5418 | { |
| 5419 | unsigned long min; |
| 5420 | |
| 5421 | mas_start(mas); |
| 5422 | if (mas_is_none(mas) || mas_is_ptr(mas)) { |
| 5423 | mas_root_expand(mas, entry); |
| 5424 | if (mas_is_err(mas)) |
| 5425 | return xa_err(mas->node); |
| 5426 | |
| 5427 | if (!mas->index) |
| 5428 | return mte_pivot(mas->node, 0); |
| 5429 | return mte_pivot(mas->node, 1); |
| 5430 | } |
| 5431 | |
| 5432 | /* Must be walking a tree. */ |
| 5433 | mas_awalk(mas, size); |
| 5434 | if (mas_is_err(mas)) |
| 5435 | return xa_err(mas->node); |
| 5436 | |
| 5437 | if (mas->offset == MAPLE_NODE_SLOTS) |
| 5438 | goto no_gap; |
| 5439 | |
| 5440 | /* |
| 5441 | * At this point, mas->node points to the right node and we have an |
| 5442 | * offset that has a sufficient gap. |
| 5443 | */ |
| 5444 | min = mas->min; |
| 5445 | if (mas->offset) |
| 5446 | min = mte_pivot(mas->node, mas->offset - 1) + 1; |
| 5447 | |
| 5448 | if (mas->index < min) |
| 5449 | mas->index = min; |
| 5450 | |
| 5451 | mas_fill_gap(mas, entry, mas->offset, size, index); |
| 5452 | return 0; |
| 5453 | |
| 5454 | no_gap: |
| 5455 | return -EBUSY; |
| 5456 | } |
| 5457 | |
| 5458 | static inline int mas_rev_alloc(struct ma_state *mas, unsigned long min, |
| 5459 | unsigned long max, void *entry, |
| 5460 | unsigned long size, unsigned long *index) |
| 5461 | { |
| 5462 | int ret = 0; |
| 5463 | |
| 5464 | ret = mas_empty_area_rev(mas, min, max, size); |
| 5465 | if (ret) |
| 5466 | return ret; |
| 5467 | |
| 5468 | if (mas_is_err(mas)) |
| 5469 | return xa_err(mas->node); |
| 5470 | |
| 5471 | if (mas->offset == MAPLE_NODE_SLOTS) |
| 5472 | goto no_gap; |
| 5473 | |
| 5474 | mas_fill_gap(mas, entry, mas->offset, size, index); |
| 5475 | return 0; |
| 5476 | |
| 5477 | no_gap: |
| 5478 | return -EBUSY; |
| 5479 | } |
| 5480 | |
| 5481 | /* |
| 5482 | * mte_dead_leaves() - Mark all leaves of a node as dead. |
| 5483 | * @mas: The maple state |
| 5484 | * @slots: Pointer to the slot array |
| 5485 | * @type: The maple node type |
| 5486 | * |
| 5487 | * Must hold the write lock. |
| 5488 | * |
| 5489 | * Return: The number of leaves marked as dead. |
| 5490 | */ |
| 5491 | static inline |
| 5492 | unsigned char mte_dead_leaves(struct maple_enode *enode, struct maple_tree *mt, |
| 5493 | void __rcu **slots) |
| 5494 | { |
| 5495 | struct maple_node *node; |
| 5496 | enum maple_type type; |
| 5497 | void *entry; |
| 5498 | int offset; |
| 5499 | |
| 5500 | for (offset = 0; offset < mt_slot_count(enode); offset++) { |
| 5501 | entry = mt_slot(mt, slots, offset); |
| 5502 | type = mte_node_type(entry); |
| 5503 | node = mte_to_node(entry); |
| 5504 | /* Use both node and type to catch LE & BE metadata */ |
| 5505 | if (!node || !type) |
| 5506 | break; |
| 5507 | |
| 5508 | mte_set_node_dead(entry); |
| 5509 | node->type = type; |
| 5510 | rcu_assign_pointer(slots[offset], node); |
| 5511 | } |
| 5512 | |
| 5513 | return offset; |
| 5514 | } |
| 5515 | |
| 5516 | /** |
| 5517 | * mte_dead_walk() - Walk down a dead tree to just before the leaves |
| 5518 | * @enode: The maple encoded node |
| 5519 | * @offset: The starting offset |
| 5520 | * |
| 5521 | * Note: This can only be used from the RCU callback context. |
| 5522 | */ |
| 5523 | static void __rcu **mte_dead_walk(struct maple_enode **enode, unsigned char offset) |
| 5524 | { |
| 5525 | struct maple_node *node, *next; |
| 5526 | void __rcu **slots = NULL; |
| 5527 | |
| 5528 | next = mte_to_node(*enode); |
| 5529 | do { |
| 5530 | *enode = ma_enode_ptr(next); |
| 5531 | node = mte_to_node(*enode); |
| 5532 | slots = ma_slots(node, node->type); |
| 5533 | next = rcu_dereference_protected(slots[offset], |
| 5534 | lock_is_held(&rcu_callback_map)); |
| 5535 | offset = 0; |
| 5536 | } while (!ma_is_leaf(next->type)); |
| 5537 | |
| 5538 | return slots; |
| 5539 | } |
| 5540 | |
| 5541 | /** |
| 5542 | * mt_free_walk() - Walk & free a tree in the RCU callback context |
| 5543 | * @head: The RCU head that's within the node. |
| 5544 | * |
| 5545 | * Note: This can only be used from the RCU callback context. |
| 5546 | */ |
| 5547 | static void mt_free_walk(struct rcu_head *head) |
| 5548 | { |
| 5549 | void __rcu **slots; |
| 5550 | struct maple_node *node, *start; |
| 5551 | struct maple_enode *enode; |
| 5552 | unsigned char offset; |
| 5553 | enum maple_type type; |
| 5554 | |
| 5555 | node = container_of(head, struct maple_node, rcu); |
| 5556 | |
| 5557 | if (ma_is_leaf(node->type)) |
| 5558 | goto free_leaf; |
| 5559 | |
| 5560 | start = node; |
| 5561 | enode = mt_mk_node(node, node->type); |
| 5562 | slots = mte_dead_walk(&enode, 0); |
| 5563 | node = mte_to_node(enode); |
| 5564 | do { |
| 5565 | mt_free_bulk(node->slot_len, slots); |
| 5566 | offset = node->parent_slot + 1; |
| 5567 | enode = node->piv_parent; |
| 5568 | if (mte_to_node(enode) == node) |
| 5569 | goto free_leaf; |
| 5570 | |
| 5571 | type = mte_node_type(enode); |
| 5572 | slots = ma_slots(mte_to_node(enode), type); |
| 5573 | if ((offset < mt_slots[type]) && |
| 5574 | rcu_dereference_protected(slots[offset], |
| 5575 | lock_is_held(&rcu_callback_map))) |
| 5576 | slots = mte_dead_walk(&enode, offset); |
| 5577 | node = mte_to_node(enode); |
| 5578 | } while ((node != start) || (node->slot_len < offset)); |
| 5579 | |
| 5580 | slots = ma_slots(node, node->type); |
| 5581 | mt_free_bulk(node->slot_len, slots); |
| 5582 | |
| 5583 | free_leaf: |
| 5584 | mt_free_rcu(&node->rcu); |
| 5585 | } |
| 5586 | |
| 5587 | static inline void __rcu **mte_destroy_descend(struct maple_enode **enode, |
| 5588 | struct maple_tree *mt, struct maple_enode *prev, unsigned char offset) |
| 5589 | { |
| 5590 | struct maple_node *node; |
| 5591 | struct maple_enode *next = *enode; |
| 5592 | void __rcu **slots = NULL; |
| 5593 | enum maple_type type; |
| 5594 | unsigned char next_offset = 0; |
| 5595 | |
| 5596 | do { |
| 5597 | *enode = next; |
| 5598 | node = mte_to_node(*enode); |
| 5599 | type = mte_node_type(*enode); |
| 5600 | slots = ma_slots(node, type); |
| 5601 | next = mt_slot_locked(mt, slots, next_offset); |
| 5602 | if ((mte_dead_node(next))) |
| 5603 | next = mt_slot_locked(mt, slots, ++next_offset); |
| 5604 | |
| 5605 | mte_set_node_dead(*enode); |
| 5606 | node->type = type; |
| 5607 | node->piv_parent = prev; |
| 5608 | node->parent_slot = offset; |
| 5609 | offset = next_offset; |
| 5610 | next_offset = 0; |
| 5611 | prev = *enode; |
| 5612 | } while (!mte_is_leaf(next)); |
| 5613 | |
| 5614 | return slots; |
| 5615 | } |
| 5616 | |
| 5617 | static void mt_destroy_walk(struct maple_enode *enode, struct maple_tree *mt, |
| 5618 | bool free) |
| 5619 | { |
| 5620 | void __rcu **slots; |
| 5621 | struct maple_node *node = mte_to_node(enode); |
| 5622 | struct maple_enode *start; |
| 5623 | |
| 5624 | if (mte_is_leaf(enode)) { |
| 5625 | node->type = mte_node_type(enode); |
| 5626 | goto free_leaf; |
| 5627 | } |
| 5628 | |
| 5629 | start = enode; |
| 5630 | slots = mte_destroy_descend(&enode, mt, start, 0); |
| 5631 | node = mte_to_node(enode); // Updated in the above call. |
| 5632 | do { |
| 5633 | enum maple_type type; |
| 5634 | unsigned char offset; |
| 5635 | struct maple_enode *parent, *tmp; |
| 5636 | |
| 5637 | node->slot_len = mte_dead_leaves(enode, mt, slots); |
| 5638 | if (free) |
| 5639 | mt_free_bulk(node->slot_len, slots); |
| 5640 | offset = node->parent_slot + 1; |
| 5641 | enode = node->piv_parent; |
| 5642 | if (mte_to_node(enode) == node) |
| 5643 | goto free_leaf; |
| 5644 | |
| 5645 | type = mte_node_type(enode); |
| 5646 | slots = ma_slots(mte_to_node(enode), type); |
| 5647 | if (offset >= mt_slots[type]) |
| 5648 | goto next; |
| 5649 | |
| 5650 | tmp = mt_slot_locked(mt, slots, offset); |
| 5651 | if (mte_node_type(tmp) && mte_to_node(tmp)) { |
| 5652 | parent = enode; |
| 5653 | enode = tmp; |
| 5654 | slots = mte_destroy_descend(&enode, mt, parent, offset); |
| 5655 | } |
| 5656 | next: |
| 5657 | node = mte_to_node(enode); |
| 5658 | } while (start != enode); |
| 5659 | |
| 5660 | node = mte_to_node(enode); |
| 5661 | node->slot_len = mte_dead_leaves(enode, mt, slots); |
| 5662 | if (free) |
| 5663 | mt_free_bulk(node->slot_len, slots); |
| 5664 | |
| 5665 | free_leaf: |
| 5666 | if (free) |
| 5667 | mt_free_rcu(&node->rcu); |
| 5668 | else |
| 5669 | mt_clear_meta(mt, node, node->type); |
| 5670 | } |
| 5671 | |
| 5672 | /* |
| 5673 | * mte_destroy_walk() - Free a tree or sub-tree. |
| 5674 | * @enode: the encoded maple node (maple_enode) to start |
| 5675 | * @mt: the tree to free - needed for node types. |
| 5676 | * |
| 5677 | * Must hold the write lock. |
| 5678 | */ |
| 5679 | static inline void mte_destroy_walk(struct maple_enode *enode, |
| 5680 | struct maple_tree *mt) |
| 5681 | { |
| 5682 | struct maple_node *node = mte_to_node(enode); |
| 5683 | |
| 5684 | if (mt_in_rcu(mt)) { |
| 5685 | mt_destroy_walk(enode, mt, false); |
| 5686 | call_rcu(&node->rcu, mt_free_walk); |
| 5687 | } else { |
| 5688 | mt_destroy_walk(enode, mt, true); |
| 5689 | } |
| 5690 | } |
| 5691 | |
| 5692 | static void mas_wr_store_setup(struct ma_wr_state *wr_mas) |
| 5693 | { |
| 5694 | if (unlikely(mas_is_paused(wr_mas->mas))) |
| 5695 | mas_reset(wr_mas->mas); |
| 5696 | |
| 5697 | if (!mas_is_start(wr_mas->mas)) { |
| 5698 | if (mas_is_none(wr_mas->mas)) { |
| 5699 | mas_reset(wr_mas->mas); |
| 5700 | } else { |
| 5701 | wr_mas->r_max = wr_mas->mas->max; |
| 5702 | wr_mas->type = mte_node_type(wr_mas->mas->node); |
| 5703 | if (mas_is_span_wr(wr_mas)) |
| 5704 | mas_reset(wr_mas->mas); |
| 5705 | } |
| 5706 | } |
| 5707 | } |
| 5708 | |
| 5709 | /* Interface */ |
| 5710 | |
| 5711 | /** |
| 5712 | * mas_store() - Store an @entry. |
| 5713 | * @mas: The maple state. |
| 5714 | * @entry: The entry to store. |
| 5715 | * |
| 5716 | * The @mas->index and @mas->last is used to set the range for the @entry. |
| 5717 | * Note: The @mas should have pre-allocated entries to ensure there is memory to |
| 5718 | * store the entry. Please see mas_expected_entries()/mas_destroy() for more details. |
| 5719 | * |
| 5720 | * Return: the first entry between mas->index and mas->last or %NULL. |
| 5721 | */ |
| 5722 | void *mas_store(struct ma_state *mas, void *entry) |
| 5723 | { |
| 5724 | MA_WR_STATE(wr_mas, mas, entry); |
| 5725 | |
| 5726 | trace_ma_write(__func__, mas, 0, entry); |
| 5727 | #ifdef CONFIG_DEBUG_MAPLE_TREE |
| 5728 | if (mas->index > mas->last) |
| 5729 | pr_err("Error %lu > %lu %p\n", mas->index, mas->last, entry); |
| 5730 | MT_BUG_ON(mas->tree, mas->index > mas->last); |
| 5731 | if (mas->index > mas->last) { |
| 5732 | mas_set_err(mas, -EINVAL); |
| 5733 | return NULL; |
| 5734 | } |
| 5735 | |
| 5736 | #endif |
| 5737 | |
| 5738 | /* |
| 5739 | * Storing is the same operation as insert with the added caveat that it |
| 5740 | * can overwrite entries. Although this seems simple enough, one may |
| 5741 | * want to examine what happens if a single store operation was to |
| 5742 | * overwrite multiple entries within a self-balancing B-Tree. |
| 5743 | */ |
| 5744 | mas_wr_store_setup(&wr_mas); |
| 5745 | mas_wr_store_entry(&wr_mas); |
| 5746 | return wr_mas.content; |
| 5747 | } |
| 5748 | EXPORT_SYMBOL_GPL(mas_store); |
| 5749 | |
| 5750 | /** |
| 5751 | * mas_store_gfp() - Store a value into the tree. |
| 5752 | * @mas: The maple state |
| 5753 | * @entry: The entry to store |
| 5754 | * @gfp: The GFP_FLAGS to use for allocations if necessary. |
| 5755 | * |
| 5756 | * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not |
| 5757 | * be allocated. |
| 5758 | */ |
| 5759 | int mas_store_gfp(struct ma_state *mas, void *entry, gfp_t gfp) |
| 5760 | { |
| 5761 | MA_WR_STATE(wr_mas, mas, entry); |
| 5762 | |
| 5763 | mas_wr_store_setup(&wr_mas); |
| 5764 | trace_ma_write(__func__, mas, 0, entry); |
| 5765 | retry: |
| 5766 | mas_wr_store_entry(&wr_mas); |
| 5767 | if (unlikely(mas_nomem(mas, gfp))) |
| 5768 | goto retry; |
| 5769 | |
| 5770 | if (unlikely(mas_is_err(mas))) |
| 5771 | return xa_err(mas->node); |
| 5772 | |
| 5773 | return 0; |
| 5774 | } |
| 5775 | EXPORT_SYMBOL_GPL(mas_store_gfp); |
| 5776 | |
| 5777 | /** |
| 5778 | * mas_store_prealloc() - Store a value into the tree using memory |
| 5779 | * preallocated in the maple state. |
| 5780 | * @mas: The maple state |
| 5781 | * @entry: The entry to store. |
| 5782 | */ |
| 5783 | void mas_store_prealloc(struct ma_state *mas, void *entry) |
| 5784 | { |
| 5785 | MA_WR_STATE(wr_mas, mas, entry); |
| 5786 | |
| 5787 | mas_wr_store_setup(&wr_mas); |
| 5788 | trace_ma_write(__func__, mas, 0, entry); |
| 5789 | mas_wr_store_entry(&wr_mas); |
| 5790 | BUG_ON(mas_is_err(mas)); |
| 5791 | mas_destroy(mas); |
| 5792 | } |
| 5793 | EXPORT_SYMBOL_GPL(mas_store_prealloc); |
| 5794 | |
| 5795 | /** |
| 5796 | * mas_preallocate() - Preallocate enough nodes for a store operation |
| 5797 | * @mas: The maple state |
| 5798 | * @gfp: The GFP_FLAGS to use for allocations. |
| 5799 | * |
| 5800 | * Return: 0 on success, -ENOMEM if memory could not be allocated. |
| 5801 | */ |
| 5802 | int mas_preallocate(struct ma_state *mas, gfp_t gfp) |
| 5803 | { |
| 5804 | int ret; |
| 5805 | |
| 5806 | mas_node_count_gfp(mas, 1 + mas_mt_height(mas) * 3, gfp); |
| 5807 | mas->mas_flags |= MA_STATE_PREALLOC; |
| 5808 | if (likely(!mas_is_err(mas))) |
| 5809 | return 0; |
| 5810 | |
| 5811 | mas_set_alloc_req(mas, 0); |
| 5812 | ret = xa_err(mas->node); |
| 5813 | mas_reset(mas); |
| 5814 | mas_destroy(mas); |
| 5815 | mas_reset(mas); |
| 5816 | return ret; |
| 5817 | } |
| 5818 | |
| 5819 | /* |
| 5820 | * mas_destroy() - destroy a maple state. |
| 5821 | * @mas: The maple state |
| 5822 | * |
| 5823 | * Upon completion, check the left-most node and rebalance against the node to |
| 5824 | * the right if necessary. Frees any allocated nodes associated with this maple |
| 5825 | * state. |
| 5826 | */ |
| 5827 | void mas_destroy(struct ma_state *mas) |
| 5828 | { |
| 5829 | struct maple_alloc *node; |
| 5830 | unsigned long total; |
| 5831 | |
| 5832 | /* |
| 5833 | * When using mas_for_each() to insert an expected number of elements, |
| 5834 | * it is possible that the number inserted is less than the expected |
| 5835 | * number. To fix an invalid final node, a check is performed here to |
| 5836 | * rebalance the previous node with the final node. |
| 5837 | */ |
| 5838 | if (mas->mas_flags & MA_STATE_REBALANCE) { |
| 5839 | unsigned char end; |
| 5840 | |
| 5841 | if (mas_is_start(mas)) |
| 5842 | mas_start(mas); |
| 5843 | |
| 5844 | mtree_range_walk(mas); |
| 5845 | end = mas_data_end(mas) + 1; |
| 5846 | if (end < mt_min_slot_count(mas->node) - 1) |
| 5847 | mas_destroy_rebalance(mas, end); |
| 5848 | |
| 5849 | mas->mas_flags &= ~MA_STATE_REBALANCE; |
| 5850 | } |
| 5851 | mas->mas_flags &= ~(MA_STATE_BULK|MA_STATE_PREALLOC); |
| 5852 | |
| 5853 | total = mas_allocated(mas); |
| 5854 | while (total) { |
| 5855 | node = mas->alloc; |
| 5856 | mas->alloc = node->slot[0]; |
| 5857 | if (node->node_count > 1) { |
| 5858 | size_t count = node->node_count - 1; |
| 5859 | |
| 5860 | mt_free_bulk(count, (void __rcu **)&node->slot[1]); |
| 5861 | total -= count; |
| 5862 | } |
| 5863 | kmem_cache_free(maple_node_cache, node); |
| 5864 | total--; |
| 5865 | } |
| 5866 | |
| 5867 | mas->alloc = NULL; |
| 5868 | } |
| 5869 | EXPORT_SYMBOL_GPL(mas_destroy); |
| 5870 | |
| 5871 | /* |
| 5872 | * mas_expected_entries() - Set the expected number of entries that will be inserted. |
| 5873 | * @mas: The maple state |
| 5874 | * @nr_entries: The number of expected entries. |
| 5875 | * |
| 5876 | * This will attempt to pre-allocate enough nodes to store the expected number |
| 5877 | * of entries. The allocations will occur using the bulk allocator interface |
| 5878 | * for speed. Please call mas_destroy() on the @mas after inserting the entries |
| 5879 | * to ensure any unused nodes are freed. |
| 5880 | * |
| 5881 | * Return: 0 on success, -ENOMEM if memory could not be allocated. |
| 5882 | */ |
| 5883 | int mas_expected_entries(struct ma_state *mas, unsigned long nr_entries) |
| 5884 | { |
| 5885 | int nonleaf_cap = MAPLE_ARANGE64_SLOTS - 2; |
| 5886 | struct maple_enode *enode = mas->node; |
| 5887 | int nr_nodes; |
| 5888 | int ret; |
| 5889 | |
| 5890 | /* |
| 5891 | * Sometimes it is necessary to duplicate a tree to a new tree, such as |
| 5892 | * forking a process and duplicating the VMAs from one tree to a new |
| 5893 | * tree. When such a situation arises, it is known that the new tree is |
| 5894 | * not going to be used until the entire tree is populated. For |
| 5895 | * performance reasons, it is best to use a bulk load with RCU disabled. |
| 5896 | * This allows for optimistic splitting that favours the left and reuse |
| 5897 | * of nodes during the operation. |
| 5898 | */ |
| 5899 | |
| 5900 | /* Optimize splitting for bulk insert in-order */ |
| 5901 | mas->mas_flags |= MA_STATE_BULK; |
| 5902 | |
| 5903 | /* |
| 5904 | * Avoid overflow, assume a gap between each entry and a trailing null. |
| 5905 | * If this is wrong, it just means allocation can happen during |
| 5906 | * insertion of entries. |
| 5907 | */ |
| 5908 | nr_nodes = max(nr_entries, nr_entries * 2 + 1); |
| 5909 | if (!mt_is_alloc(mas->tree)) |
| 5910 | nonleaf_cap = MAPLE_RANGE64_SLOTS - 2; |
| 5911 | |
| 5912 | /* Leaves; reduce slots to keep space for expansion */ |
| 5913 | nr_nodes = DIV_ROUND_UP(nr_nodes, MAPLE_RANGE64_SLOTS - 2); |
| 5914 | /* Internal nodes */ |
| 5915 | nr_nodes += DIV_ROUND_UP(nr_nodes, nonleaf_cap); |
| 5916 | /* Add working room for split (2 nodes) + new parents */ |
| 5917 | mas_node_count(mas, nr_nodes + 3); |
| 5918 | |
| 5919 | /* Detect if allocations run out */ |
| 5920 | mas->mas_flags |= MA_STATE_PREALLOC; |
| 5921 | |
| 5922 | if (!mas_is_err(mas)) |
| 5923 | return 0; |
| 5924 | |
| 5925 | ret = xa_err(mas->node); |
| 5926 | mas->node = enode; |
| 5927 | mas_destroy(mas); |
| 5928 | return ret; |
| 5929 | |
| 5930 | } |
| 5931 | EXPORT_SYMBOL_GPL(mas_expected_entries); |
| 5932 | |
| 5933 | /** |
| 5934 | * mas_next() - Get the next entry. |
| 5935 | * @mas: The maple state |
| 5936 | * @max: The maximum index to check. |
| 5937 | * |
| 5938 | * Returns the next entry after @mas->index. |
| 5939 | * Must hold rcu_read_lock or the write lock. |
| 5940 | * Can return the zero entry. |
| 5941 | * |
| 5942 | * Return: The next entry or %NULL |
| 5943 | */ |
| 5944 | void *mas_next(struct ma_state *mas, unsigned long max) |
| 5945 | { |
| 5946 | if (mas_is_none(mas) || mas_is_paused(mas)) |
| 5947 | mas->node = MAS_START; |
| 5948 | |
| 5949 | if (mas_is_start(mas)) |
| 5950 | mas_walk(mas); /* Retries on dead nodes handled by mas_walk */ |
| 5951 | |
| 5952 | if (mas_is_ptr(mas)) { |
| 5953 | if (!mas->index) { |
| 5954 | mas->index = 1; |
| 5955 | mas->last = ULONG_MAX; |
| 5956 | } |
| 5957 | return NULL; |
| 5958 | } |
| 5959 | |
| 5960 | if (mas->last == ULONG_MAX) |
| 5961 | return NULL; |
| 5962 | |
| 5963 | /* Retries on dead nodes handled by mas_next_entry */ |
| 5964 | return mas_next_entry(mas, max); |
| 5965 | } |
| 5966 | EXPORT_SYMBOL_GPL(mas_next); |
| 5967 | |
| 5968 | /** |
| 5969 | * mt_next() - get the next value in the maple tree |
| 5970 | * @mt: The maple tree |
| 5971 | * @index: The start index |
| 5972 | * @max: The maximum index to check |
| 5973 | * |
| 5974 | * Return: The entry at @index or higher, or %NULL if nothing is found. |
| 5975 | */ |
| 5976 | void *mt_next(struct maple_tree *mt, unsigned long index, unsigned long max) |
| 5977 | { |
| 5978 | void *entry = NULL; |
| 5979 | MA_STATE(mas, mt, index, index); |
| 5980 | |
| 5981 | rcu_read_lock(); |
| 5982 | entry = mas_next(&mas, max); |
| 5983 | rcu_read_unlock(); |
| 5984 | return entry; |
| 5985 | } |
| 5986 | EXPORT_SYMBOL_GPL(mt_next); |
| 5987 | |
| 5988 | /** |
| 5989 | * mas_prev() - Get the previous entry |
| 5990 | * @mas: The maple state |
| 5991 | * @min: The minimum value to check. |
| 5992 | * |
| 5993 | * Must hold rcu_read_lock or the write lock. |
| 5994 | * Will reset mas to MAS_START if the node is MAS_NONE. Will stop on not |
| 5995 | * searchable nodes. |
| 5996 | * |
| 5997 | * Return: the previous value or %NULL. |
| 5998 | */ |
| 5999 | void *mas_prev(struct ma_state *mas, unsigned long min) |
| 6000 | { |
| 6001 | if (!mas->index) { |
| 6002 | /* Nothing comes before 0 */ |
| 6003 | mas->last = 0; |
| 6004 | mas->node = MAS_NONE; |
| 6005 | return NULL; |
| 6006 | } |
| 6007 | |
| 6008 | if (unlikely(mas_is_ptr(mas))) |
| 6009 | return NULL; |
| 6010 | |
| 6011 | if (mas_is_none(mas) || mas_is_paused(mas)) |
| 6012 | mas->node = MAS_START; |
| 6013 | |
| 6014 | if (mas_is_start(mas)) { |
| 6015 | mas_walk(mas); |
| 6016 | if (!mas->index) |
| 6017 | return NULL; |
| 6018 | } |
| 6019 | |
| 6020 | if (mas_is_ptr(mas)) { |
| 6021 | if (!mas->index) { |
| 6022 | mas->last = 0; |
| 6023 | return NULL; |
| 6024 | } |
| 6025 | |
| 6026 | mas->index = mas->last = 0; |
| 6027 | return mas_root_locked(mas); |
| 6028 | } |
| 6029 | return mas_prev_entry(mas, min); |
| 6030 | } |
| 6031 | EXPORT_SYMBOL_GPL(mas_prev); |
| 6032 | |
| 6033 | /** |
| 6034 | * mt_prev() - get the previous value in the maple tree |
| 6035 | * @mt: The maple tree |
| 6036 | * @index: The start index |
| 6037 | * @min: The minimum index to check |
| 6038 | * |
| 6039 | * Return: The entry at @index or lower, or %NULL if nothing is found. |
| 6040 | */ |
| 6041 | void *mt_prev(struct maple_tree *mt, unsigned long index, unsigned long min) |
| 6042 | { |
| 6043 | void *entry = NULL; |
| 6044 | MA_STATE(mas, mt, index, index); |
| 6045 | |
| 6046 | rcu_read_lock(); |
| 6047 | entry = mas_prev(&mas, min); |
| 6048 | rcu_read_unlock(); |
| 6049 | return entry; |
| 6050 | } |
| 6051 | EXPORT_SYMBOL_GPL(mt_prev); |
| 6052 | |
| 6053 | /** |
| 6054 | * mas_pause() - Pause a mas_find/mas_for_each to drop the lock. |
| 6055 | * @mas: The maple state to pause |
| 6056 | * |
| 6057 | * Some users need to pause a walk and drop the lock they're holding in |
| 6058 | * order to yield to a higher priority thread or carry out an operation |
| 6059 | * on an entry. Those users should call this function before they drop |
| 6060 | * the lock. It resets the @mas to be suitable for the next iteration |
| 6061 | * of the loop after the user has reacquired the lock. If most entries |
| 6062 | * found during a walk require you to call mas_pause(), the mt_for_each() |
| 6063 | * iterator may be more appropriate. |
| 6064 | * |
| 6065 | */ |
| 6066 | void mas_pause(struct ma_state *mas) |
| 6067 | { |
| 6068 | mas->node = MAS_PAUSE; |
| 6069 | } |
| 6070 | EXPORT_SYMBOL_GPL(mas_pause); |
| 6071 | |
| 6072 | /** |
| 6073 | * mas_find() - On the first call, find the entry at or after mas->index up to |
| 6074 | * %max. Otherwise, find the entry after mas->index. |
| 6075 | * @mas: The maple state |
| 6076 | * @max: The maximum value to check. |
| 6077 | * |
| 6078 | * Must hold rcu_read_lock or the write lock. |
| 6079 | * If an entry exists, last and index are updated accordingly. |
| 6080 | * May set @mas->node to MAS_NONE. |
| 6081 | * |
| 6082 | * Return: The entry or %NULL. |
| 6083 | */ |
| 6084 | void *mas_find(struct ma_state *mas, unsigned long max) |
| 6085 | { |
| 6086 | if (unlikely(mas_is_paused(mas))) { |
| 6087 | if (unlikely(mas->last == ULONG_MAX)) { |
| 6088 | mas->node = MAS_NONE; |
| 6089 | return NULL; |
| 6090 | } |
| 6091 | mas->node = MAS_START; |
| 6092 | mas->index = ++mas->last; |
| 6093 | } |
| 6094 | |
| 6095 | if (unlikely(mas_is_none(mas))) |
| 6096 | mas->node = MAS_START; |
| 6097 | |
| 6098 | if (unlikely(mas_is_start(mas))) { |
| 6099 | /* First run or continue */ |
| 6100 | void *entry; |
| 6101 | |
| 6102 | if (mas->index > max) |
| 6103 | return NULL; |
| 6104 | |
| 6105 | entry = mas_walk(mas); |
| 6106 | if (entry) |
| 6107 | return entry; |
| 6108 | } |
| 6109 | |
| 6110 | if (unlikely(!mas_searchable(mas))) |
| 6111 | return NULL; |
| 6112 | |
| 6113 | /* Retries on dead nodes handled by mas_next_entry */ |
| 6114 | return mas_next_entry(mas, max); |
| 6115 | } |
| 6116 | EXPORT_SYMBOL_GPL(mas_find); |
| 6117 | |
| 6118 | /** |
| 6119 | * mas_find_rev: On the first call, find the first non-null entry at or below |
| 6120 | * mas->index down to %min. Otherwise find the first non-null entry below |
| 6121 | * mas->index down to %min. |
| 6122 | * @mas: The maple state |
| 6123 | * @min: The minimum value to check. |
| 6124 | * |
| 6125 | * Must hold rcu_read_lock or the write lock. |
| 6126 | * If an entry exists, last and index are updated accordingly. |
| 6127 | * May set @mas->node to MAS_NONE. |
| 6128 | * |
| 6129 | * Return: The entry or %NULL. |
| 6130 | */ |
| 6131 | void *mas_find_rev(struct ma_state *mas, unsigned long min) |
| 6132 | { |
| 6133 | if (unlikely(mas_is_paused(mas))) { |
| 6134 | if (unlikely(mas->last == ULONG_MAX)) { |
| 6135 | mas->node = MAS_NONE; |
| 6136 | return NULL; |
| 6137 | } |
| 6138 | mas->node = MAS_START; |
| 6139 | mas->last = --mas->index; |
| 6140 | } |
| 6141 | |
| 6142 | if (unlikely(mas_is_start(mas))) { |
| 6143 | /* First run or continue */ |
| 6144 | void *entry; |
| 6145 | |
| 6146 | if (mas->index < min) |
| 6147 | return NULL; |
| 6148 | |
| 6149 | entry = mas_walk(mas); |
| 6150 | if (entry) |
| 6151 | return entry; |
| 6152 | } |
| 6153 | |
| 6154 | if (unlikely(!mas_searchable(mas))) |
| 6155 | return NULL; |
| 6156 | |
| 6157 | if (mas->index < min) |
| 6158 | return NULL; |
| 6159 | |
| 6160 | /* Retries on dead nodes handled by mas_prev_entry */ |
| 6161 | return mas_prev_entry(mas, min); |
| 6162 | } |
| 6163 | EXPORT_SYMBOL_GPL(mas_find_rev); |
| 6164 | |
| 6165 | /** |
| 6166 | * mas_erase() - Find the range in which index resides and erase the entire |
| 6167 | * range. |
| 6168 | * @mas: The maple state |
| 6169 | * |
| 6170 | * Must hold the write lock. |
| 6171 | * Searches for @mas->index, sets @mas->index and @mas->last to the range and |
| 6172 | * erases that range. |
| 6173 | * |
| 6174 | * Return: the entry that was erased or %NULL, @mas->index and @mas->last are updated. |
| 6175 | */ |
| 6176 | void *mas_erase(struct ma_state *mas) |
| 6177 | { |
| 6178 | void *entry; |
| 6179 | MA_WR_STATE(wr_mas, mas, NULL); |
| 6180 | |
| 6181 | if (mas_is_none(mas) || mas_is_paused(mas)) |
| 6182 | mas->node = MAS_START; |
| 6183 | |
| 6184 | /* Retry unnecessary when holding the write lock. */ |
| 6185 | entry = mas_state_walk(mas); |
| 6186 | if (!entry) |
| 6187 | return NULL; |
| 6188 | |
| 6189 | write_retry: |
| 6190 | /* Must reset to ensure spanning writes of last slot are detected */ |
| 6191 | mas_reset(mas); |
| 6192 | mas_wr_store_setup(&wr_mas); |
| 6193 | mas_wr_store_entry(&wr_mas); |
| 6194 | if (mas_nomem(mas, GFP_KERNEL)) |
| 6195 | goto write_retry; |
| 6196 | |
| 6197 | return entry; |
| 6198 | } |
| 6199 | EXPORT_SYMBOL_GPL(mas_erase); |
| 6200 | |
| 6201 | /** |
| 6202 | * mas_nomem() - Check if there was an error allocating and do the allocation |
| 6203 | * if necessary If there are allocations, then free them. |
| 6204 | * @mas: The maple state |
| 6205 | * @gfp: The GFP_FLAGS to use for allocations |
| 6206 | * Return: true on allocation, false otherwise. |
| 6207 | */ |
| 6208 | bool mas_nomem(struct ma_state *mas, gfp_t gfp) |
| 6209 | __must_hold(mas->tree->lock) |
| 6210 | { |
| 6211 | if (likely(mas->node != MA_ERROR(-ENOMEM))) { |
| 6212 | mas_destroy(mas); |
| 6213 | return false; |
| 6214 | } |
| 6215 | |
| 6216 | if (gfpflags_allow_blocking(gfp) && !mt_external_lock(mas->tree)) { |
| 6217 | mtree_unlock(mas->tree); |
| 6218 | mas_alloc_nodes(mas, gfp); |
| 6219 | mtree_lock(mas->tree); |
| 6220 | } else { |
| 6221 | mas_alloc_nodes(mas, gfp); |
| 6222 | } |
| 6223 | |
| 6224 | if (!mas_allocated(mas)) |
| 6225 | return false; |
| 6226 | |
| 6227 | mas->node = MAS_START; |
| 6228 | return true; |
| 6229 | } |
| 6230 | |
| 6231 | void __init maple_tree_init(void) |
| 6232 | { |
| 6233 | maple_node_cache = kmem_cache_create("maple_node", |
| 6234 | sizeof(struct maple_node), sizeof(struct maple_node), |
| 6235 | SLAB_PANIC, NULL); |
| 6236 | } |
| 6237 | |
| 6238 | /** |
| 6239 | * mtree_load() - Load a value stored in a maple tree |
| 6240 | * @mt: The maple tree |
| 6241 | * @index: The index to load |
| 6242 | * |
| 6243 | * Return: the entry or %NULL |
| 6244 | */ |
| 6245 | void *mtree_load(struct maple_tree *mt, unsigned long index) |
| 6246 | { |
| 6247 | MA_STATE(mas, mt, index, index); |
| 6248 | void *entry; |
| 6249 | |
| 6250 | trace_ma_read(__func__, &mas); |
| 6251 | rcu_read_lock(); |
| 6252 | retry: |
| 6253 | entry = mas_start(&mas); |
| 6254 | if (unlikely(mas_is_none(&mas))) |
| 6255 | goto unlock; |
| 6256 | |
| 6257 | if (unlikely(mas_is_ptr(&mas))) { |
| 6258 | if (index) |
| 6259 | entry = NULL; |
| 6260 | |
| 6261 | goto unlock; |
| 6262 | } |
| 6263 | |
| 6264 | entry = mtree_lookup_walk(&mas); |
| 6265 | if (!entry && unlikely(mas_is_start(&mas))) |
| 6266 | goto retry; |
| 6267 | unlock: |
| 6268 | rcu_read_unlock(); |
| 6269 | if (xa_is_zero(entry)) |
| 6270 | return NULL; |
| 6271 | |
| 6272 | return entry; |
| 6273 | } |
| 6274 | EXPORT_SYMBOL(mtree_load); |
| 6275 | |
| 6276 | /** |
| 6277 | * mtree_store_range() - Store an entry at a given range. |
| 6278 | * @mt: The maple tree |
| 6279 | * @index: The start of the range |
| 6280 | * @last: The end of the range |
| 6281 | * @entry: The entry to store |
| 6282 | * @gfp: The GFP_FLAGS to use for allocations |
| 6283 | * |
| 6284 | * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not |
| 6285 | * be allocated. |
| 6286 | */ |
| 6287 | int mtree_store_range(struct maple_tree *mt, unsigned long index, |
| 6288 | unsigned long last, void *entry, gfp_t gfp) |
| 6289 | { |
| 6290 | MA_STATE(mas, mt, index, last); |
| 6291 | MA_WR_STATE(wr_mas, &mas, entry); |
| 6292 | |
| 6293 | trace_ma_write(__func__, &mas, 0, entry); |
| 6294 | if (WARN_ON_ONCE(xa_is_advanced(entry))) |
| 6295 | return -EINVAL; |
| 6296 | |
| 6297 | if (index > last) |
| 6298 | return -EINVAL; |
| 6299 | |
| 6300 | mtree_lock(mt); |
| 6301 | retry: |
| 6302 | mas_wr_store_entry(&wr_mas); |
| 6303 | if (mas_nomem(&mas, gfp)) |
| 6304 | goto retry; |
| 6305 | |
| 6306 | mtree_unlock(mt); |
| 6307 | if (mas_is_err(&mas)) |
| 6308 | return xa_err(mas.node); |
| 6309 | |
| 6310 | return 0; |
| 6311 | } |
| 6312 | EXPORT_SYMBOL(mtree_store_range); |
| 6313 | |
| 6314 | /** |
| 6315 | * mtree_store() - Store an entry at a given index. |
| 6316 | * @mt: The maple tree |
| 6317 | * @index: The index to store the value |
| 6318 | * @entry: The entry to store |
| 6319 | * @gfp: The GFP_FLAGS to use for allocations |
| 6320 | * |
| 6321 | * Return: 0 on success, -EINVAL on invalid request, -ENOMEM if memory could not |
| 6322 | * be allocated. |
| 6323 | */ |
| 6324 | int mtree_store(struct maple_tree *mt, unsigned long index, void *entry, |
| 6325 | gfp_t gfp) |
| 6326 | { |
| 6327 | return mtree_store_range(mt, index, index, entry, gfp); |
| 6328 | } |
| 6329 | EXPORT_SYMBOL(mtree_store); |
| 6330 | |
| 6331 | /** |
| 6332 | * mtree_insert_range() - Insert an entry at a give range if there is no value. |
| 6333 | * @mt: The maple tree |
| 6334 | * @first: The start of the range |
| 6335 | * @last: The end of the range |
| 6336 | * @entry: The entry to store |
| 6337 | * @gfp: The GFP_FLAGS to use for allocations. |
| 6338 | * |
| 6339 | * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid |
| 6340 | * request, -ENOMEM if memory could not be allocated. |
| 6341 | */ |
| 6342 | int mtree_insert_range(struct maple_tree *mt, unsigned long first, |
| 6343 | unsigned long last, void *entry, gfp_t gfp) |
| 6344 | { |
| 6345 | MA_STATE(ms, mt, first, last); |
| 6346 | |
| 6347 | if (WARN_ON_ONCE(xa_is_advanced(entry))) |
| 6348 | return -EINVAL; |
| 6349 | |
| 6350 | if (first > last) |
| 6351 | return -EINVAL; |
| 6352 | |
| 6353 | mtree_lock(mt); |
| 6354 | retry: |
| 6355 | mas_insert(&ms, entry); |
| 6356 | if (mas_nomem(&ms, gfp)) |
| 6357 | goto retry; |
| 6358 | |
| 6359 | mtree_unlock(mt); |
| 6360 | if (mas_is_err(&ms)) |
| 6361 | return xa_err(ms.node); |
| 6362 | |
| 6363 | return 0; |
| 6364 | } |
| 6365 | EXPORT_SYMBOL(mtree_insert_range); |
| 6366 | |
| 6367 | /** |
| 6368 | * mtree_insert() - Insert an entry at a give index if there is no value. |
| 6369 | * @mt: The maple tree |
| 6370 | * @index : The index to store the value |
| 6371 | * @entry: The entry to store |
| 6372 | * @gfp: The FGP_FLAGS to use for allocations. |
| 6373 | * |
| 6374 | * Return: 0 on success, -EEXISTS if the range is occupied, -EINVAL on invalid |
| 6375 | * request, -ENOMEM if memory could not be allocated. |
| 6376 | */ |
| 6377 | int mtree_insert(struct maple_tree *mt, unsigned long index, void *entry, |
| 6378 | gfp_t gfp) |
| 6379 | { |
| 6380 | return mtree_insert_range(mt, index, index, entry, gfp); |
| 6381 | } |
| 6382 | EXPORT_SYMBOL(mtree_insert); |
| 6383 | |
| 6384 | int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp, |
| 6385 | void *entry, unsigned long size, unsigned long min, |
| 6386 | unsigned long max, gfp_t gfp) |
| 6387 | { |
| 6388 | int ret = 0; |
| 6389 | |
| 6390 | MA_STATE(mas, mt, min, max - size); |
| 6391 | if (!mt_is_alloc(mt)) |
| 6392 | return -EINVAL; |
| 6393 | |
| 6394 | if (WARN_ON_ONCE(mt_is_reserved(entry))) |
| 6395 | return -EINVAL; |
| 6396 | |
| 6397 | if (min > max) |
| 6398 | return -EINVAL; |
| 6399 | |
| 6400 | if (max < size) |
| 6401 | return -EINVAL; |
| 6402 | |
| 6403 | if (!size) |
| 6404 | return -EINVAL; |
| 6405 | |
| 6406 | mtree_lock(mt); |
| 6407 | retry: |
| 6408 | mas.offset = 0; |
| 6409 | mas.index = min; |
| 6410 | mas.last = max - size; |
| 6411 | ret = mas_alloc(&mas, entry, size, startp); |
| 6412 | if (mas_nomem(&mas, gfp)) |
| 6413 | goto retry; |
| 6414 | |
| 6415 | mtree_unlock(mt); |
| 6416 | return ret; |
| 6417 | } |
| 6418 | EXPORT_SYMBOL(mtree_alloc_range); |
| 6419 | |
| 6420 | int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp, |
| 6421 | void *entry, unsigned long size, unsigned long min, |
| 6422 | unsigned long max, gfp_t gfp) |
| 6423 | { |
| 6424 | int ret = 0; |
| 6425 | |
| 6426 | MA_STATE(mas, mt, min, max - size); |
| 6427 | if (!mt_is_alloc(mt)) |
| 6428 | return -EINVAL; |
| 6429 | |
| 6430 | if (WARN_ON_ONCE(mt_is_reserved(entry))) |
| 6431 | return -EINVAL; |
| 6432 | |
| 6433 | if (min >= max) |
| 6434 | return -EINVAL; |
| 6435 | |
| 6436 | if (max < size - 1) |
| 6437 | return -EINVAL; |
| 6438 | |
| 6439 | if (!size) |
| 6440 | return -EINVAL; |
| 6441 | |
| 6442 | mtree_lock(mt); |
| 6443 | retry: |
| 6444 | ret = mas_rev_alloc(&mas, min, max, entry, size, startp); |
| 6445 | if (mas_nomem(&mas, gfp)) |
| 6446 | goto retry; |
| 6447 | |
| 6448 | mtree_unlock(mt); |
| 6449 | return ret; |
| 6450 | } |
| 6451 | EXPORT_SYMBOL(mtree_alloc_rrange); |
| 6452 | |
| 6453 | /** |
| 6454 | * mtree_erase() - Find an index and erase the entire range. |
| 6455 | * @mt: The maple tree |
| 6456 | * @index: The index to erase |
| 6457 | * |
| 6458 | * Erasing is the same as a walk to an entry then a store of a NULL to that |
| 6459 | * ENTIRE range. In fact, it is implemented as such using the advanced API. |
| 6460 | * |
| 6461 | * Return: The entry stored at the @index or %NULL |
| 6462 | */ |
| 6463 | void *mtree_erase(struct maple_tree *mt, unsigned long index) |
| 6464 | { |
| 6465 | void *entry = NULL; |
| 6466 | |
| 6467 | MA_STATE(mas, mt, index, index); |
| 6468 | trace_ma_op(__func__, &mas); |
| 6469 | |
| 6470 | mtree_lock(mt); |
| 6471 | entry = mas_erase(&mas); |
| 6472 | mtree_unlock(mt); |
| 6473 | |
| 6474 | return entry; |
| 6475 | } |
| 6476 | EXPORT_SYMBOL(mtree_erase); |
| 6477 | |
| 6478 | /** |
| 6479 | * __mt_destroy() - Walk and free all nodes of a locked maple tree. |
| 6480 | * @mt: The maple tree |
| 6481 | * |
| 6482 | * Note: Does not handle locking. |
| 6483 | */ |
| 6484 | void __mt_destroy(struct maple_tree *mt) |
| 6485 | { |
| 6486 | void *root = mt_root_locked(mt); |
| 6487 | |
| 6488 | rcu_assign_pointer(mt->ma_root, NULL); |
| 6489 | if (xa_is_node(root)) |
| 6490 | mte_destroy_walk(root, mt); |
| 6491 | |
| 6492 | mt->ma_flags = 0; |
| 6493 | } |
| 6494 | EXPORT_SYMBOL_GPL(__mt_destroy); |
| 6495 | |
| 6496 | /** |
| 6497 | * mtree_destroy() - Destroy a maple tree |
| 6498 | * @mt: The maple tree |
| 6499 | * |
| 6500 | * Frees all resources used by the tree. Handles locking. |
| 6501 | */ |
| 6502 | void mtree_destroy(struct maple_tree *mt) |
| 6503 | { |
| 6504 | mtree_lock(mt); |
| 6505 | __mt_destroy(mt); |
| 6506 | mtree_unlock(mt); |
| 6507 | } |
| 6508 | EXPORT_SYMBOL(mtree_destroy); |
| 6509 | |
| 6510 | /** |
| 6511 | * mt_find() - Search from the start up until an entry is found. |
| 6512 | * @mt: The maple tree |
| 6513 | * @index: Pointer which contains the start location of the search |
| 6514 | * @max: The maximum value to check |
| 6515 | * |
| 6516 | * Handles locking. @index will be incremented to one beyond the range. |
| 6517 | * |
| 6518 | * Return: The entry at or after the @index or %NULL |
| 6519 | */ |
| 6520 | void *mt_find(struct maple_tree *mt, unsigned long *index, unsigned long max) |
| 6521 | { |
| 6522 | MA_STATE(mas, mt, *index, *index); |
| 6523 | void *entry; |
| 6524 | #ifdef CONFIG_DEBUG_MAPLE_TREE |
| 6525 | unsigned long copy = *index; |
| 6526 | #endif |
| 6527 | |
| 6528 | trace_ma_read(__func__, &mas); |
| 6529 | |
| 6530 | if ((*index) > max) |
| 6531 | return NULL; |
| 6532 | |
| 6533 | rcu_read_lock(); |
| 6534 | retry: |
| 6535 | entry = mas_state_walk(&mas); |
| 6536 | if (mas_is_start(&mas)) |
| 6537 | goto retry; |
| 6538 | |
| 6539 | if (unlikely(xa_is_zero(entry))) |
| 6540 | entry = NULL; |
| 6541 | |
| 6542 | if (entry) |
| 6543 | goto unlock; |
| 6544 | |
| 6545 | while (mas_searchable(&mas) && (mas.index < max)) { |
| 6546 | entry = mas_next_entry(&mas, max); |
| 6547 | if (likely(entry && !xa_is_zero(entry))) |
| 6548 | break; |
| 6549 | } |
| 6550 | |
| 6551 | if (unlikely(xa_is_zero(entry))) |
| 6552 | entry = NULL; |
| 6553 | unlock: |
| 6554 | rcu_read_unlock(); |
| 6555 | if (likely(entry)) { |
| 6556 | *index = mas.last + 1; |
| 6557 | #ifdef CONFIG_DEBUG_MAPLE_TREE |
| 6558 | if ((*index) && (*index) <= copy) |
| 6559 | pr_err("index not increased! %lx <= %lx\n", |
| 6560 | *index, copy); |
| 6561 | MT_BUG_ON(mt, (*index) && ((*index) <= copy)); |
| 6562 | #endif |
| 6563 | } |
| 6564 | |
| 6565 | return entry; |
| 6566 | } |
| 6567 | EXPORT_SYMBOL(mt_find); |
| 6568 | |
| 6569 | /** |
| 6570 | * mt_find_after() - Search from the start up until an entry is found. |
| 6571 | * @mt: The maple tree |
| 6572 | * @index: Pointer which contains the start location of the search |
| 6573 | * @max: The maximum value to check |
| 6574 | * |
| 6575 | * Handles locking, detects wrapping on index == 0 |
| 6576 | * |
| 6577 | * Return: The entry at or after the @index or %NULL |
| 6578 | */ |
| 6579 | void *mt_find_after(struct maple_tree *mt, unsigned long *index, |
| 6580 | unsigned long max) |
| 6581 | { |
| 6582 | if (!(*index)) |
| 6583 | return NULL; |
| 6584 | |
| 6585 | return mt_find(mt, index, max); |
| 6586 | } |
| 6587 | EXPORT_SYMBOL(mt_find_after); |
| 6588 | |
| 6589 | #ifdef CONFIG_DEBUG_MAPLE_TREE |
| 6590 | atomic_t maple_tree_tests_run; |
| 6591 | EXPORT_SYMBOL_GPL(maple_tree_tests_run); |
| 6592 | atomic_t maple_tree_tests_passed; |
| 6593 | EXPORT_SYMBOL_GPL(maple_tree_tests_passed); |
| 6594 | |
| 6595 | #ifndef __KERNEL__ |
| 6596 | extern void kmem_cache_set_non_kernel(struct kmem_cache *, unsigned int); |
| 6597 | void mt_set_non_kernel(unsigned int val) |
| 6598 | { |
| 6599 | kmem_cache_set_non_kernel(maple_node_cache, val); |
| 6600 | } |
| 6601 | |
| 6602 | extern unsigned long kmem_cache_get_alloc(struct kmem_cache *); |
| 6603 | unsigned long mt_get_alloc_size(void) |
| 6604 | { |
| 6605 | return kmem_cache_get_alloc(maple_node_cache); |
| 6606 | } |
| 6607 | |
| 6608 | extern void kmem_cache_zero_nr_tallocated(struct kmem_cache *); |
| 6609 | void mt_zero_nr_tallocated(void) |
| 6610 | { |
| 6611 | kmem_cache_zero_nr_tallocated(maple_node_cache); |
| 6612 | } |
| 6613 | |
| 6614 | extern unsigned int kmem_cache_nr_tallocated(struct kmem_cache *); |
| 6615 | unsigned int mt_nr_tallocated(void) |
| 6616 | { |
| 6617 | return kmem_cache_nr_tallocated(maple_node_cache); |
| 6618 | } |
| 6619 | |
| 6620 | extern unsigned int kmem_cache_nr_allocated(struct kmem_cache *); |
| 6621 | unsigned int mt_nr_allocated(void) |
| 6622 | { |
| 6623 | return kmem_cache_nr_allocated(maple_node_cache); |
| 6624 | } |
| 6625 | |
| 6626 | /* |
| 6627 | * mas_dead_node() - Check if the maple state is pointing to a dead node. |
| 6628 | * @mas: The maple state |
| 6629 | * @index: The index to restore in @mas. |
| 6630 | * |
| 6631 | * Used in test code. |
| 6632 | * Return: 1 if @mas has been reset to MAS_START, 0 otherwise. |
| 6633 | */ |
| 6634 | static inline int mas_dead_node(struct ma_state *mas, unsigned long index) |
| 6635 | { |
| 6636 | if (unlikely(!mas_searchable(mas) || mas_is_start(mas))) |
| 6637 | return 0; |
| 6638 | |
| 6639 | if (likely(!mte_dead_node(mas->node))) |
| 6640 | return 0; |
| 6641 | |
| 6642 | mas_rewalk(mas, index); |
| 6643 | return 1; |
| 6644 | } |
| 6645 | |
| 6646 | void mt_cache_shrink(void) |
| 6647 | { |
| 6648 | } |
| 6649 | #else |
| 6650 | /* |
| 6651 | * mt_cache_shrink() - For testing, don't use this. |
| 6652 | * |
| 6653 | * Certain testcases can trigger an OOM when combined with other memory |
| 6654 | * debugging configuration options. This function is used to reduce the |
| 6655 | * possibility of an out of memory even due to kmem_cache objects remaining |
| 6656 | * around for longer than usual. |
| 6657 | */ |
| 6658 | void mt_cache_shrink(void) |
| 6659 | { |
| 6660 | kmem_cache_shrink(maple_node_cache); |
| 6661 | |
| 6662 | } |
| 6663 | EXPORT_SYMBOL_GPL(mt_cache_shrink); |
| 6664 | |
| 6665 | #endif /* not defined __KERNEL__ */ |
| 6666 | /* |
| 6667 | * mas_get_slot() - Get the entry in the maple state node stored at @offset. |
| 6668 | * @mas: The maple state |
| 6669 | * @offset: The offset into the slot array to fetch. |
| 6670 | * |
| 6671 | * Return: The entry stored at @offset. |
| 6672 | */ |
| 6673 | static inline struct maple_enode *mas_get_slot(struct ma_state *mas, |
| 6674 | unsigned char offset) |
| 6675 | { |
| 6676 | return mas_slot(mas, ma_slots(mas_mn(mas), mte_node_type(mas->node)), |
| 6677 | offset); |
| 6678 | } |
| 6679 | |
| 6680 | |
| 6681 | /* |
| 6682 | * mas_first_entry() - Go the first leaf and find the first entry. |
| 6683 | * @mas: the maple state. |
| 6684 | * @limit: the maximum index to check. |
| 6685 | * @*r_start: Pointer to set to the range start. |
| 6686 | * |
| 6687 | * Sets mas->offset to the offset of the entry, r_start to the range minimum. |
| 6688 | * |
| 6689 | * Return: The first entry or MAS_NONE. |
| 6690 | */ |
| 6691 | static inline void *mas_first_entry(struct ma_state *mas, struct maple_node *mn, |
| 6692 | unsigned long limit, enum maple_type mt) |
| 6693 | |
| 6694 | { |
| 6695 | unsigned long max; |
| 6696 | unsigned long *pivots; |
| 6697 | void __rcu **slots; |
| 6698 | void *entry = NULL; |
| 6699 | |
| 6700 | mas->index = mas->min; |
| 6701 | if (mas->index > limit) |
| 6702 | goto none; |
| 6703 | |
| 6704 | max = mas->max; |
| 6705 | mas->offset = 0; |
| 6706 | while (likely(!ma_is_leaf(mt))) { |
| 6707 | MT_BUG_ON(mas->tree, mte_dead_node(mas->node)); |
| 6708 | slots = ma_slots(mn, mt); |
| 6709 | entry = mas_slot(mas, slots, 0); |
| 6710 | pivots = ma_pivots(mn, mt); |
| 6711 | if (unlikely(ma_dead_node(mn))) |
| 6712 | return NULL; |
| 6713 | max = pivots[0]; |
| 6714 | mas->node = entry; |
| 6715 | mn = mas_mn(mas); |
| 6716 | mt = mte_node_type(mas->node); |
| 6717 | } |
| 6718 | MT_BUG_ON(mas->tree, mte_dead_node(mas->node)); |
| 6719 | |
| 6720 | mas->max = max; |
| 6721 | slots = ma_slots(mn, mt); |
| 6722 | entry = mas_slot(mas, slots, 0); |
| 6723 | if (unlikely(ma_dead_node(mn))) |
| 6724 | return NULL; |
| 6725 | |
| 6726 | /* Slot 0 or 1 must be set */ |
| 6727 | if (mas->index > limit) |
| 6728 | goto none; |
| 6729 | |
| 6730 | if (likely(entry)) |
| 6731 | return entry; |
| 6732 | |
| 6733 | mas->offset = 1; |
| 6734 | entry = mas_slot(mas, slots, 1); |
| 6735 | pivots = ma_pivots(mn, mt); |
| 6736 | if (unlikely(ma_dead_node(mn))) |
| 6737 | return NULL; |
| 6738 | |
| 6739 | mas->index = pivots[0] + 1; |
| 6740 | if (mas->index > limit) |
| 6741 | goto none; |
| 6742 | |
| 6743 | if (likely(entry)) |
| 6744 | return entry; |
| 6745 | |
| 6746 | none: |
| 6747 | if (likely(!ma_dead_node(mn))) |
| 6748 | mas->node = MAS_NONE; |
| 6749 | return NULL; |
| 6750 | } |
| 6751 | |
| 6752 | /* Depth first search, post-order */ |
| 6753 | static void mas_dfs_postorder(struct ma_state *mas, unsigned long max) |
| 6754 | { |
| 6755 | |
| 6756 | struct maple_enode *p = MAS_NONE, *mn = mas->node; |
| 6757 | unsigned long p_min, p_max; |
| 6758 | |
| 6759 | mas_next_node(mas, mas_mn(mas), max); |
| 6760 | if (!mas_is_none(mas)) |
| 6761 | return; |
| 6762 | |
| 6763 | if (mte_is_root(mn)) |
| 6764 | return; |
| 6765 | |
| 6766 | mas->node = mn; |
| 6767 | mas_ascend(mas); |
| 6768 | while (mas->node != MAS_NONE) { |
| 6769 | p = mas->node; |
| 6770 | p_min = mas->min; |
| 6771 | p_max = mas->max; |
| 6772 | mas_prev_node(mas, 0); |
| 6773 | } |
| 6774 | |
| 6775 | if (p == MAS_NONE) |
| 6776 | return; |
| 6777 | |
| 6778 | mas->node = p; |
| 6779 | mas->max = p_max; |
| 6780 | mas->min = p_min; |
| 6781 | } |
| 6782 | |
| 6783 | /* Tree validations */ |
| 6784 | static void mt_dump_node(const struct maple_tree *mt, void *entry, |
| 6785 | unsigned long min, unsigned long max, unsigned int depth); |
| 6786 | static void mt_dump_range(unsigned long min, unsigned long max, |
| 6787 | unsigned int depth) |
| 6788 | { |
| 6789 | static const char spaces[] = " "; |
| 6790 | |
| 6791 | if (min == max) |
| 6792 | pr_info("%.*s%lu: ", depth * 2, spaces, min); |
| 6793 | else |
| 6794 | pr_info("%.*s%lu-%lu: ", depth * 2, spaces, min, max); |
| 6795 | } |
| 6796 | |
| 6797 | static void mt_dump_entry(void *entry, unsigned long min, unsigned long max, |
| 6798 | unsigned int depth) |
| 6799 | { |
| 6800 | mt_dump_range(min, max, depth); |
| 6801 | |
| 6802 | if (xa_is_value(entry)) |
| 6803 | pr_cont("value %ld (0x%lx) [%p]\n", xa_to_value(entry), |
| 6804 | xa_to_value(entry), entry); |
| 6805 | else if (xa_is_zero(entry)) |
| 6806 | pr_cont("zero (%ld)\n", xa_to_internal(entry)); |
| 6807 | else if (mt_is_reserved(entry)) |
| 6808 | pr_cont("UNKNOWN ENTRY (%p)\n", entry); |
| 6809 | else |
| 6810 | pr_cont("%p\n", entry); |
| 6811 | } |
| 6812 | |
| 6813 | static void mt_dump_range64(const struct maple_tree *mt, void *entry, |
| 6814 | unsigned long min, unsigned long max, unsigned int depth) |
| 6815 | { |
| 6816 | struct maple_range_64 *node = &mte_to_node(entry)->mr64; |
| 6817 | bool leaf = mte_is_leaf(entry); |
| 6818 | unsigned long first = min; |
| 6819 | int i; |
| 6820 | |
| 6821 | pr_cont(" contents: "); |
| 6822 | for (i = 0; i < MAPLE_RANGE64_SLOTS - 1; i++) |
| 6823 | pr_cont("%p %lu ", node->slot[i], node->pivot[i]); |
| 6824 | pr_cont("%p\n", node->slot[i]); |
| 6825 | for (i = 0; i < MAPLE_RANGE64_SLOTS; i++) { |
| 6826 | unsigned long last = max; |
| 6827 | |
| 6828 | if (i < (MAPLE_RANGE64_SLOTS - 1)) |
| 6829 | last = node->pivot[i]; |
| 6830 | else if (!node->slot[i] && max != mt_node_max(entry)) |
| 6831 | break; |
| 6832 | if (last == 0 && i > 0) |
| 6833 | break; |
| 6834 | if (leaf) |
| 6835 | mt_dump_entry(mt_slot(mt, node->slot, i), |
| 6836 | first, last, depth + 1); |
| 6837 | else if (node->slot[i]) |
| 6838 | mt_dump_node(mt, mt_slot(mt, node->slot, i), |
| 6839 | first, last, depth + 1); |
| 6840 | |
| 6841 | if (last == max) |
| 6842 | break; |
| 6843 | if (last > max) { |
| 6844 | pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n", |
| 6845 | node, last, max, i); |
| 6846 | break; |
| 6847 | } |
| 6848 | first = last + 1; |
| 6849 | } |
| 6850 | } |
| 6851 | |
| 6852 | static void mt_dump_arange64(const struct maple_tree *mt, void *entry, |
| 6853 | unsigned long min, unsigned long max, unsigned int depth) |
| 6854 | { |
| 6855 | struct maple_arange_64 *node = &mte_to_node(entry)->ma64; |
| 6856 | bool leaf = mte_is_leaf(entry); |
| 6857 | unsigned long first = min; |
| 6858 | int i; |
| 6859 | |
| 6860 | pr_cont(" contents: "); |
| 6861 | for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) |
| 6862 | pr_cont("%lu ", node->gap[i]); |
| 6863 | pr_cont("| %02X %02X| ", node->meta.end, node->meta.gap); |
| 6864 | for (i = 0; i < MAPLE_ARANGE64_SLOTS - 1; i++) |
| 6865 | pr_cont("%p %lu ", node->slot[i], node->pivot[i]); |
| 6866 | pr_cont("%p\n", node->slot[i]); |
| 6867 | for (i = 0; i < MAPLE_ARANGE64_SLOTS; i++) { |
| 6868 | unsigned long last = max; |
| 6869 | |
| 6870 | if (i < (MAPLE_ARANGE64_SLOTS - 1)) |
| 6871 | last = node->pivot[i]; |
| 6872 | else if (!node->slot[i]) |
| 6873 | break; |
| 6874 | if (last == 0 && i > 0) |
| 6875 | break; |
| 6876 | if (leaf) |
| 6877 | mt_dump_entry(mt_slot(mt, node->slot, i), |
| 6878 | first, last, depth + 1); |
| 6879 | else if (node->slot[i]) |
| 6880 | mt_dump_node(mt, mt_slot(mt, node->slot, i), |
| 6881 | first, last, depth + 1); |
| 6882 | |
| 6883 | if (last == max) |
| 6884 | break; |
| 6885 | if (last > max) { |
| 6886 | pr_err("node %p last (%lu) > max (%lu) at pivot %d!\n", |
| 6887 | node, last, max, i); |
| 6888 | break; |
| 6889 | } |
| 6890 | first = last + 1; |
| 6891 | } |
| 6892 | } |
| 6893 | |
| 6894 | static void mt_dump_node(const struct maple_tree *mt, void *entry, |
| 6895 | unsigned long min, unsigned long max, unsigned int depth) |
| 6896 | { |
| 6897 | struct maple_node *node = mte_to_node(entry); |
| 6898 | unsigned int type = mte_node_type(entry); |
| 6899 | unsigned int i; |
| 6900 | |
| 6901 | mt_dump_range(min, max, depth); |
| 6902 | |
| 6903 | pr_cont("node %p depth %d type %d parent %p", node, depth, type, |
| 6904 | node ? node->parent : NULL); |
| 6905 | switch (type) { |
| 6906 | case maple_dense: |
| 6907 | pr_cont("\n"); |
| 6908 | for (i = 0; i < MAPLE_NODE_SLOTS; i++) { |
| 6909 | if (min + i > max) |
| 6910 | pr_cont("OUT OF RANGE: "); |
| 6911 | mt_dump_entry(mt_slot(mt, node->slot, i), |
| 6912 | min + i, min + i, depth); |
| 6913 | } |
| 6914 | break; |
| 6915 | case maple_leaf_64: |
| 6916 | case maple_range_64: |
| 6917 | mt_dump_range64(mt, entry, min, max, depth); |
| 6918 | break; |
| 6919 | case maple_arange_64: |
| 6920 | mt_dump_arange64(mt, entry, min, max, depth); |
| 6921 | break; |
| 6922 | |
| 6923 | default: |
| 6924 | pr_cont(" UNKNOWN TYPE\n"); |
| 6925 | } |
| 6926 | } |
| 6927 | |
| 6928 | void mt_dump(const struct maple_tree *mt) |
| 6929 | { |
| 6930 | void *entry = rcu_dereference_check(mt->ma_root, mt_locked(mt)); |
| 6931 | |
| 6932 | pr_info("maple_tree(%p) flags %X, height %u root %p\n", |
| 6933 | mt, mt->ma_flags, mt_height(mt), entry); |
| 6934 | if (!xa_is_node(entry)) |
| 6935 | mt_dump_entry(entry, 0, 0, 0); |
| 6936 | else if (entry) |
| 6937 | mt_dump_node(mt, entry, 0, mt_node_max(entry), 0); |
| 6938 | } |
| 6939 | EXPORT_SYMBOL_GPL(mt_dump); |
| 6940 | |
| 6941 | /* |
| 6942 | * Calculate the maximum gap in a node and check if that's what is reported in |
| 6943 | * the parent (unless root). |
| 6944 | */ |
| 6945 | static void mas_validate_gaps(struct ma_state *mas) |
| 6946 | { |
| 6947 | struct maple_enode *mte = mas->node; |
| 6948 | struct maple_node *p_mn; |
| 6949 | unsigned long gap = 0, max_gap = 0; |
| 6950 | unsigned long p_end, p_start = mas->min; |
| 6951 | unsigned char p_slot; |
| 6952 | unsigned long *gaps = NULL; |
| 6953 | unsigned long *pivots = ma_pivots(mte_to_node(mte), mte_node_type(mte)); |
| 6954 | int i; |
| 6955 | |
| 6956 | if (ma_is_dense(mte_node_type(mte))) { |
| 6957 | for (i = 0; i < mt_slot_count(mte); i++) { |
| 6958 | if (mas_get_slot(mas, i)) { |
| 6959 | if (gap > max_gap) |
| 6960 | max_gap = gap; |
| 6961 | gap = 0; |
| 6962 | continue; |
| 6963 | } |
| 6964 | gap++; |
| 6965 | } |
| 6966 | goto counted; |
| 6967 | } |
| 6968 | |
| 6969 | gaps = ma_gaps(mte_to_node(mte), mte_node_type(mte)); |
| 6970 | for (i = 0; i < mt_slot_count(mte); i++) { |
| 6971 | p_end = mas_logical_pivot(mas, pivots, i, mte_node_type(mte)); |
| 6972 | |
| 6973 | if (!gaps) { |
| 6974 | if (mas_get_slot(mas, i)) { |
| 6975 | gap = 0; |
| 6976 | goto not_empty; |
| 6977 | } |
| 6978 | |
| 6979 | gap += p_end - p_start + 1; |
| 6980 | } else { |
| 6981 | void *entry = mas_get_slot(mas, i); |
| 6982 | |
| 6983 | gap = gaps[i]; |
| 6984 | if (!entry) { |
| 6985 | if (gap != p_end - p_start + 1) { |
| 6986 | pr_err("%p[%u] -> %p %lu != %lu - %lu + 1\n", |
| 6987 | mas_mn(mas), i, |
| 6988 | mas_get_slot(mas, i), gap, |
| 6989 | p_end, p_start); |
| 6990 | mt_dump(mas->tree); |
| 6991 | |
| 6992 | MT_BUG_ON(mas->tree, |
| 6993 | gap != p_end - p_start + 1); |
| 6994 | } |
| 6995 | } else { |
| 6996 | if (gap > p_end - p_start + 1) { |
| 6997 | pr_err("%p[%u] %lu >= %lu - %lu + 1 (%lu)\n", |
| 6998 | mas_mn(mas), i, gap, p_end, p_start, |
| 6999 | p_end - p_start + 1); |
| 7000 | MT_BUG_ON(mas->tree, |
| 7001 | gap > p_end - p_start + 1); |
| 7002 | } |
| 7003 | } |
| 7004 | } |
| 7005 | |
| 7006 | if (gap > max_gap) |
| 7007 | max_gap = gap; |
| 7008 | not_empty: |
| 7009 | p_start = p_end + 1; |
| 7010 | if (p_end >= mas->max) |
| 7011 | break; |
| 7012 | } |
| 7013 | |
| 7014 | counted: |
| 7015 | if (mte_is_root(mte)) |
| 7016 | return; |
| 7017 | |
| 7018 | p_slot = mte_parent_slot(mas->node); |
| 7019 | p_mn = mte_parent(mte); |
| 7020 | MT_BUG_ON(mas->tree, max_gap > mas->max); |
| 7021 | if (ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap) { |
| 7022 | pr_err("gap %p[%u] != %lu\n", p_mn, p_slot, max_gap); |
| 7023 | mt_dump(mas->tree); |
| 7024 | } |
| 7025 | |
| 7026 | MT_BUG_ON(mas->tree, |
| 7027 | ma_gaps(p_mn, mas_parent_enum(mas, mte))[p_slot] != max_gap); |
| 7028 | } |
| 7029 | |
| 7030 | static void mas_validate_parent_slot(struct ma_state *mas) |
| 7031 | { |
| 7032 | struct maple_node *parent; |
| 7033 | struct maple_enode *node; |
| 7034 | enum maple_type p_type = mas_parent_enum(mas, mas->node); |
| 7035 | unsigned char p_slot = mte_parent_slot(mas->node); |
| 7036 | void __rcu **slots; |
| 7037 | int i; |
| 7038 | |
| 7039 | if (mte_is_root(mas->node)) |
| 7040 | return; |
| 7041 | |
| 7042 | parent = mte_parent(mas->node); |
| 7043 | slots = ma_slots(parent, p_type); |
| 7044 | MT_BUG_ON(mas->tree, mas_mn(mas) == parent); |
| 7045 | |
| 7046 | /* Check prev/next parent slot for duplicate node entry */ |
| 7047 | |
| 7048 | for (i = 0; i < mt_slots[p_type]; i++) { |
| 7049 | node = mas_slot(mas, slots, i); |
| 7050 | if (i == p_slot) { |
| 7051 | if (node != mas->node) |
| 7052 | pr_err("parent %p[%u] does not have %p\n", |
| 7053 | parent, i, mas_mn(mas)); |
| 7054 | MT_BUG_ON(mas->tree, node != mas->node); |
| 7055 | } else if (node == mas->node) { |
| 7056 | pr_err("Invalid child %p at parent %p[%u] p_slot %u\n", |
| 7057 | mas_mn(mas), parent, i, p_slot); |
| 7058 | MT_BUG_ON(mas->tree, node == mas->node); |
| 7059 | } |
| 7060 | } |
| 7061 | } |
| 7062 | |
| 7063 | static void mas_validate_child_slot(struct ma_state *mas) |
| 7064 | { |
| 7065 | enum maple_type type = mte_node_type(mas->node); |
| 7066 | void __rcu **slots = ma_slots(mte_to_node(mas->node), type); |
| 7067 | unsigned long *pivots = ma_pivots(mte_to_node(mas->node), type); |
| 7068 | struct maple_enode *child; |
| 7069 | unsigned char i; |
| 7070 | |
| 7071 | if (mte_is_leaf(mas->node)) |
| 7072 | return; |
| 7073 | |
| 7074 | for (i = 0; i < mt_slots[type]; i++) { |
| 7075 | child = mas_slot(mas, slots, i); |
| 7076 | if (!pivots[i] || pivots[i] == mas->max) |
| 7077 | break; |
| 7078 | |
| 7079 | if (!child) |
| 7080 | break; |
| 7081 | |
| 7082 | if (mte_parent_slot(child) != i) { |
| 7083 | pr_err("Slot error at %p[%u]: child %p has pslot %u\n", |
| 7084 | mas_mn(mas), i, mte_to_node(child), |
| 7085 | mte_parent_slot(child)); |
| 7086 | MT_BUG_ON(mas->tree, 1); |
| 7087 | } |
| 7088 | |
| 7089 | if (mte_parent(child) != mte_to_node(mas->node)) { |
| 7090 | pr_err("child %p has parent %p not %p\n", |
| 7091 | mte_to_node(child), mte_parent(child), |
| 7092 | mte_to_node(mas->node)); |
| 7093 | MT_BUG_ON(mas->tree, 1); |
| 7094 | } |
| 7095 | } |
| 7096 | } |
| 7097 | |
| 7098 | /* |
| 7099 | * Validate all pivots are within mas->min and mas->max. |
| 7100 | */ |
| 7101 | static void mas_validate_limits(struct ma_state *mas) |
| 7102 | { |
| 7103 | int i; |
| 7104 | unsigned long prev_piv = 0; |
| 7105 | enum maple_type type = mte_node_type(mas->node); |
| 7106 | void __rcu **slots = ma_slots(mte_to_node(mas->node), type); |
| 7107 | unsigned long *pivots = ma_pivots(mas_mn(mas), type); |
| 7108 | |
| 7109 | /* all limits are fine here. */ |
| 7110 | if (mte_is_root(mas->node)) |
| 7111 | return; |
| 7112 | |
| 7113 | for (i = 0; i < mt_slots[type]; i++) { |
| 7114 | unsigned long piv; |
| 7115 | |
| 7116 | piv = mas_safe_pivot(mas, pivots, i, type); |
| 7117 | |
| 7118 | if (!piv && (i != 0)) |
| 7119 | break; |
| 7120 | |
| 7121 | if (!mte_is_leaf(mas->node)) { |
| 7122 | void *entry = mas_slot(mas, slots, i); |
| 7123 | |
| 7124 | if (!entry) |
| 7125 | pr_err("%p[%u] cannot be null\n", |
| 7126 | mas_mn(mas), i); |
| 7127 | |
| 7128 | MT_BUG_ON(mas->tree, !entry); |
| 7129 | } |
| 7130 | |
| 7131 | if (prev_piv > piv) { |
| 7132 | pr_err("%p[%u] piv %lu < prev_piv %lu\n", |
| 7133 | mas_mn(mas), i, piv, prev_piv); |
| 7134 | MT_BUG_ON(mas->tree, piv < prev_piv); |
| 7135 | } |
| 7136 | |
| 7137 | if (piv < mas->min) { |
| 7138 | pr_err("%p[%u] %lu < %lu\n", mas_mn(mas), i, |
| 7139 | piv, mas->min); |
| 7140 | MT_BUG_ON(mas->tree, piv < mas->min); |
| 7141 | } |
| 7142 | if (piv > mas->max) { |
| 7143 | pr_err("%p[%u] %lu > %lu\n", mas_mn(mas), i, |
| 7144 | piv, mas->max); |
| 7145 | MT_BUG_ON(mas->tree, piv > mas->max); |
| 7146 | } |
| 7147 | prev_piv = piv; |
| 7148 | if (piv == mas->max) |
| 7149 | break; |
| 7150 | } |
| 7151 | for (i += 1; i < mt_slots[type]; i++) { |
| 7152 | void *entry = mas_slot(mas, slots, i); |
| 7153 | |
| 7154 | if (entry && (i != mt_slots[type] - 1)) { |
| 7155 | pr_err("%p[%u] should not have entry %p\n", mas_mn(mas), |
| 7156 | i, entry); |
| 7157 | MT_BUG_ON(mas->tree, entry != NULL); |
| 7158 | } |
| 7159 | |
| 7160 | if (i < mt_pivots[type]) { |
| 7161 | unsigned long piv = pivots[i]; |
| 7162 | |
| 7163 | if (!piv) |
| 7164 | continue; |
| 7165 | |
| 7166 | pr_err("%p[%u] should not have piv %lu\n", |
| 7167 | mas_mn(mas), i, piv); |
| 7168 | MT_BUG_ON(mas->tree, i < mt_pivots[type] - 1); |
| 7169 | } |
| 7170 | } |
| 7171 | } |
| 7172 | |
| 7173 | static void mt_validate_nulls(struct maple_tree *mt) |
| 7174 | { |
| 7175 | void *entry, *last = (void *)1; |
| 7176 | unsigned char offset = 0; |
| 7177 | void __rcu **slots; |
| 7178 | MA_STATE(mas, mt, 0, 0); |
| 7179 | |
| 7180 | mas_start(&mas); |
| 7181 | if (mas_is_none(&mas) || (mas.node == MAS_ROOT)) |
| 7182 | return; |
| 7183 | |
| 7184 | while (!mte_is_leaf(mas.node)) |
| 7185 | mas_descend(&mas); |
| 7186 | |
| 7187 | slots = ma_slots(mte_to_node(mas.node), mte_node_type(mas.node)); |
| 7188 | do { |
| 7189 | entry = mas_slot(&mas, slots, offset); |
| 7190 | if (!last && !entry) { |
| 7191 | pr_err("Sequential nulls end at %p[%u]\n", |
| 7192 | mas_mn(&mas), offset); |
| 7193 | } |
| 7194 | MT_BUG_ON(mt, !last && !entry); |
| 7195 | last = entry; |
| 7196 | if (offset == mas_data_end(&mas)) { |
| 7197 | mas_next_node(&mas, mas_mn(&mas), ULONG_MAX); |
| 7198 | if (mas_is_none(&mas)) |
| 7199 | return; |
| 7200 | offset = 0; |
| 7201 | slots = ma_slots(mte_to_node(mas.node), |
| 7202 | mte_node_type(mas.node)); |
| 7203 | } else { |
| 7204 | offset++; |
| 7205 | } |
| 7206 | |
| 7207 | } while (!mas_is_none(&mas)); |
| 7208 | } |
| 7209 | |
| 7210 | /* |
| 7211 | * validate a maple tree by checking: |
| 7212 | * 1. The limits (pivots are within mas->min to mas->max) |
| 7213 | * 2. The gap is correctly set in the parents |
| 7214 | */ |
| 7215 | void mt_validate(struct maple_tree *mt) |
| 7216 | { |
| 7217 | unsigned char end; |
| 7218 | |
| 7219 | MA_STATE(mas, mt, 0, 0); |
| 7220 | rcu_read_lock(); |
| 7221 | mas_start(&mas); |
| 7222 | if (!mas_searchable(&mas)) |
| 7223 | goto done; |
| 7224 | |
| 7225 | mas_first_entry(&mas, mas_mn(&mas), ULONG_MAX, mte_node_type(mas.node)); |
| 7226 | while (!mas_is_none(&mas)) { |
| 7227 | MT_BUG_ON(mas.tree, mte_dead_node(mas.node)); |
| 7228 | if (!mte_is_root(mas.node)) { |
| 7229 | end = mas_data_end(&mas); |
| 7230 | if ((end < mt_min_slot_count(mas.node)) && |
| 7231 | (mas.max != ULONG_MAX)) { |
| 7232 | pr_err("Invalid size %u of %p\n", end, |
| 7233 | mas_mn(&mas)); |
| 7234 | MT_BUG_ON(mas.tree, 1); |
| 7235 | } |
| 7236 | |
| 7237 | } |
| 7238 | mas_validate_parent_slot(&mas); |
| 7239 | mas_validate_child_slot(&mas); |
| 7240 | mas_validate_limits(&mas); |
| 7241 | if (mt_is_alloc(mt)) |
| 7242 | mas_validate_gaps(&mas); |
| 7243 | mas_dfs_postorder(&mas, ULONG_MAX); |
| 7244 | } |
| 7245 | mt_validate_nulls(mt); |
| 7246 | done: |
| 7247 | rcu_read_unlock(); |
| 7248 | |
| 7249 | } |
| 7250 | EXPORT_SYMBOL_GPL(mt_validate); |
| 7251 | |
| 7252 | #endif /* CONFIG_DEBUG_MAPLE_TREE */ |