Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2011 Red Hat, Inc. |
| 3 | * |
| 4 | * This file is released under the GPL. |
| 5 | */ |
| 6 | |
| 7 | #include "dm-btree-internal.h" |
| 8 | #include "dm-space-map.h" |
| 9 | #include "dm-transaction-manager.h" |
| 10 | |
Paul Gortmaker | 1944ce6 | 2011-09-28 18:29:32 -0400 | [diff] [blame] | 11 | #include <linux/export.h> |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 12 | #include <linux/device-mapper.h> |
| 13 | |
| 14 | #define DM_MSG_PREFIX "btree" |
| 15 | |
| 16 | /*---------------------------------------------------------------- |
| 17 | * Array manipulation |
| 18 | *--------------------------------------------------------------*/ |
| 19 | static void memcpy_disk(void *dest, const void *src, size_t len) |
| 20 | __dm_written_to_disk(src) |
| 21 | { |
| 22 | memcpy(dest, src, len); |
| 23 | __dm_unbless_for_disk(src); |
| 24 | } |
| 25 | |
| 26 | static void array_insert(void *base, size_t elt_size, unsigned nr_elts, |
| 27 | unsigned index, void *elt) |
| 28 | __dm_written_to_disk(elt) |
| 29 | { |
| 30 | if (index < nr_elts) |
| 31 | memmove(base + (elt_size * (index + 1)), |
| 32 | base + (elt_size * index), |
| 33 | (nr_elts - index) * elt_size); |
| 34 | |
| 35 | memcpy_disk(base + (elt_size * index), elt, elt_size); |
| 36 | } |
| 37 | |
| 38 | /*----------------------------------------------------------------*/ |
| 39 | |
| 40 | /* makes the assumption that no two keys are the same. */ |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 41 | static int bsearch(struct btree_node *n, uint64_t key, int want_hi) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 42 | { |
| 43 | int lo = -1, hi = le32_to_cpu(n->header.nr_entries); |
| 44 | |
| 45 | while (hi - lo > 1) { |
| 46 | int mid = lo + ((hi - lo) / 2); |
| 47 | uint64_t mid_key = le64_to_cpu(n->keys[mid]); |
| 48 | |
| 49 | if (mid_key == key) |
| 50 | return mid; |
| 51 | |
| 52 | if (mid_key < key) |
| 53 | lo = mid; |
| 54 | else |
| 55 | hi = mid; |
| 56 | } |
| 57 | |
| 58 | return want_hi ? hi : lo; |
| 59 | } |
| 60 | |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 61 | int lower_bound(struct btree_node *n, uint64_t key) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 62 | { |
| 63 | return bsearch(n, key, 0); |
| 64 | } |
| 65 | |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 66 | void inc_children(struct dm_transaction_manager *tm, struct btree_node *n, |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 67 | struct dm_btree_value_type *vt) |
| 68 | { |
| 69 | unsigned i; |
| 70 | uint32_t nr_entries = le32_to_cpu(n->header.nr_entries); |
| 71 | |
| 72 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) |
| 73 | for (i = 0; i < nr_entries; i++) |
| 74 | dm_tm_inc(tm, value64(n, i)); |
| 75 | else if (vt->inc) |
| 76 | for (i = 0; i < nr_entries; i++) |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 77 | vt->inc(vt->context, value_ptr(n, i)); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 78 | } |
| 79 | |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 80 | static int insert_at(size_t value_size, struct btree_node *node, unsigned index, |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 81 | uint64_t key, void *value) |
| 82 | __dm_written_to_disk(value) |
| 83 | { |
| 84 | uint32_t nr_entries = le32_to_cpu(node->header.nr_entries); |
| 85 | __le64 key_le = cpu_to_le64(key); |
| 86 | |
| 87 | if (index > nr_entries || |
| 88 | index >= le32_to_cpu(node->header.max_entries)) { |
| 89 | DMERR("too many entries in btree node for insert"); |
| 90 | __dm_unbless_for_disk(value); |
| 91 | return -ENOMEM; |
| 92 | } |
| 93 | |
| 94 | __dm_bless_for_disk(&key_le); |
| 95 | |
| 96 | array_insert(node->keys, sizeof(*node->keys), nr_entries, index, &key_le); |
| 97 | array_insert(value_base(node), value_size, nr_entries, index, value); |
| 98 | node->header.nr_entries = cpu_to_le32(nr_entries + 1); |
| 99 | |
| 100 | return 0; |
| 101 | } |
| 102 | |
| 103 | /*----------------------------------------------------------------*/ |
| 104 | |
| 105 | /* |
| 106 | * We want 3n entries (for some n). This works more nicely for repeated |
| 107 | * insert remove loops than (2n + 1). |
| 108 | */ |
| 109 | static uint32_t calc_max_entries(size_t value_size, size_t block_size) |
| 110 | { |
| 111 | uint32_t total, n; |
| 112 | size_t elt_size = sizeof(uint64_t) + value_size; /* key + value */ |
| 113 | |
| 114 | block_size -= sizeof(struct node_header); |
| 115 | total = block_size / elt_size; |
| 116 | n = total / 3; /* rounds down */ |
| 117 | |
| 118 | return 3 * n; |
| 119 | } |
| 120 | |
| 121 | int dm_btree_empty(struct dm_btree_info *info, dm_block_t *root) |
| 122 | { |
| 123 | int r; |
| 124 | struct dm_block *b; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 125 | struct btree_node *n; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 126 | size_t block_size; |
| 127 | uint32_t max_entries; |
| 128 | |
| 129 | r = new_block(info, &b); |
| 130 | if (r < 0) |
| 131 | return r; |
| 132 | |
| 133 | block_size = dm_bm_block_size(dm_tm_get_bm(info->tm)); |
| 134 | max_entries = calc_max_entries(info->value_type.size, block_size); |
| 135 | |
| 136 | n = dm_block_data(b); |
| 137 | memset(n, 0, block_size); |
| 138 | n->header.flags = cpu_to_le32(LEAF_NODE); |
| 139 | n->header.nr_entries = cpu_to_le32(0); |
| 140 | n->header.max_entries = cpu_to_le32(max_entries); |
| 141 | n->header.value_size = cpu_to_le32(info->value_type.size); |
| 142 | |
| 143 | *root = dm_block_location(b); |
Mikulas Patocka | 4c7da06 | 2015-10-22 16:46:59 -0400 | [diff] [blame] | 144 | unlock_block(info, b); |
| 145 | |
| 146 | return 0; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 147 | } |
| 148 | EXPORT_SYMBOL_GPL(dm_btree_empty); |
| 149 | |
| 150 | /*----------------------------------------------------------------*/ |
| 151 | |
| 152 | /* |
| 153 | * Deletion uses a recursive algorithm, since we have limited stack space |
| 154 | * we explicitly manage our own stack on the heap. |
| 155 | */ |
| 156 | #define MAX_SPINE_DEPTH 64 |
| 157 | struct frame { |
| 158 | struct dm_block *b; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 159 | struct btree_node *n; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 160 | unsigned level; |
| 161 | unsigned nr_children; |
| 162 | unsigned current_child; |
| 163 | }; |
| 164 | |
| 165 | struct del_stack { |
Joe Thornber | 04f17c8 | 2013-08-09 12:59:30 +0100 | [diff] [blame] | 166 | struct dm_btree_info *info; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 167 | struct dm_transaction_manager *tm; |
| 168 | int top; |
| 169 | struct frame spine[MAX_SPINE_DEPTH]; |
| 170 | }; |
| 171 | |
| 172 | static int top_frame(struct del_stack *s, struct frame **f) |
| 173 | { |
| 174 | if (s->top < 0) { |
| 175 | DMERR("btree deletion stack empty"); |
| 176 | return -EINVAL; |
| 177 | } |
| 178 | |
| 179 | *f = s->spine + s->top; |
| 180 | |
| 181 | return 0; |
| 182 | } |
| 183 | |
| 184 | static int unprocessed_frames(struct del_stack *s) |
| 185 | { |
| 186 | return s->top >= 0; |
| 187 | } |
| 188 | |
Joe Thornber | 04f17c8 | 2013-08-09 12:59:30 +0100 | [diff] [blame] | 189 | static void prefetch_children(struct del_stack *s, struct frame *f) |
| 190 | { |
| 191 | unsigned i; |
| 192 | struct dm_block_manager *bm = dm_tm_get_bm(s->tm); |
| 193 | |
| 194 | for (i = 0; i < f->nr_children; i++) |
| 195 | dm_bm_prefetch(bm, value64(f->n, i)); |
| 196 | } |
| 197 | |
| 198 | static bool is_internal_level(struct dm_btree_info *info, struct frame *f) |
| 199 | { |
| 200 | return f->level < (info->levels - 1); |
| 201 | } |
| 202 | |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 203 | static int push_frame(struct del_stack *s, dm_block_t b, unsigned level) |
| 204 | { |
| 205 | int r; |
| 206 | uint32_t ref_count; |
| 207 | |
| 208 | if (s->top >= MAX_SPINE_DEPTH - 1) { |
| 209 | DMERR("btree deletion stack out of memory"); |
| 210 | return -ENOMEM; |
| 211 | } |
| 212 | |
| 213 | r = dm_tm_ref(s->tm, b, &ref_count); |
| 214 | if (r) |
| 215 | return r; |
| 216 | |
| 217 | if (ref_count > 1) |
| 218 | /* |
| 219 | * This is a shared node, so we can just decrement it's |
| 220 | * reference counter and leave the children. |
| 221 | */ |
| 222 | dm_tm_dec(s->tm, b); |
| 223 | |
| 224 | else { |
Joe Thornber | 04f17c8 | 2013-08-09 12:59:30 +0100 | [diff] [blame] | 225 | uint32_t flags; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 226 | struct frame *f = s->spine + ++s->top; |
| 227 | |
| 228 | r = dm_tm_read_lock(s->tm, b, &btree_node_validator, &f->b); |
| 229 | if (r) { |
| 230 | s->top--; |
| 231 | return r; |
| 232 | } |
| 233 | |
| 234 | f->n = dm_block_data(f->b); |
| 235 | f->level = level; |
| 236 | f->nr_children = le32_to_cpu(f->n->header.nr_entries); |
| 237 | f->current_child = 0; |
Joe Thornber | 04f17c8 | 2013-08-09 12:59:30 +0100 | [diff] [blame] | 238 | |
| 239 | flags = le32_to_cpu(f->n->header.flags); |
| 240 | if (flags & INTERNAL_NODE || is_internal_level(s->info, f)) |
| 241 | prefetch_children(s, f); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 242 | } |
| 243 | |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | static void pop_frame(struct del_stack *s) |
| 248 | { |
| 249 | struct frame *f = s->spine + s->top--; |
| 250 | |
| 251 | dm_tm_dec(s->tm, dm_block_location(f->b)); |
| 252 | dm_tm_unlock(s->tm, f->b); |
| 253 | } |
| 254 | |
| 255 | int dm_btree_del(struct dm_btree_info *info, dm_block_t root) |
| 256 | { |
| 257 | int r; |
| 258 | struct del_stack *s; |
| 259 | |
Joe Thornber | 1c75187 | 2015-07-03 14:51:32 +0100 | [diff] [blame] | 260 | s = kmalloc(sizeof(*s), GFP_NOIO); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 261 | if (!s) |
| 262 | return -ENOMEM; |
Joe Thornber | 04f17c8 | 2013-08-09 12:59:30 +0100 | [diff] [blame] | 263 | s->info = info; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 264 | s->tm = info->tm; |
| 265 | s->top = -1; |
| 266 | |
Joe Thornber | e3cbf94 | 2012-12-21 20:23:32 +0000 | [diff] [blame] | 267 | r = push_frame(s, root, 0); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 268 | if (r) |
| 269 | goto out; |
| 270 | |
| 271 | while (unprocessed_frames(s)) { |
| 272 | uint32_t flags; |
| 273 | struct frame *f; |
| 274 | dm_block_t b; |
| 275 | |
| 276 | r = top_frame(s, &f); |
| 277 | if (r) |
| 278 | goto out; |
| 279 | |
| 280 | if (f->current_child >= f->nr_children) { |
| 281 | pop_frame(s); |
| 282 | continue; |
| 283 | } |
| 284 | |
| 285 | flags = le32_to_cpu(f->n->header.flags); |
| 286 | if (flags & INTERNAL_NODE) { |
| 287 | b = value64(f->n, f->current_child); |
| 288 | f->current_child++; |
| 289 | r = push_frame(s, b, f->level); |
| 290 | if (r) |
| 291 | goto out; |
| 292 | |
Joe Thornber | e3cbf94 | 2012-12-21 20:23:32 +0000 | [diff] [blame] | 293 | } else if (is_internal_level(info, f)) { |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 294 | b = value64(f->n, f->current_child); |
| 295 | f->current_child++; |
| 296 | r = push_frame(s, b, f->level + 1); |
| 297 | if (r) |
| 298 | goto out; |
| 299 | |
| 300 | } else { |
| 301 | if (info->value_type.dec) { |
| 302 | unsigned i; |
| 303 | |
| 304 | for (i = 0; i < f->nr_children; i++) |
| 305 | info->value_type.dec(info->value_type.context, |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 306 | value_ptr(f->n, i)); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 307 | } |
Joe Thornber | cd5acf0 | 2013-08-09 12:48:42 +0100 | [diff] [blame] | 308 | pop_frame(s); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 309 | } |
| 310 | } |
| 311 | |
| 312 | out: |
| 313 | kfree(s); |
| 314 | return r; |
| 315 | } |
| 316 | EXPORT_SYMBOL_GPL(dm_btree_del); |
| 317 | |
| 318 | /*----------------------------------------------------------------*/ |
| 319 | |
| 320 | static int btree_lookup_raw(struct ro_spine *s, dm_block_t block, uint64_t key, |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 321 | int (*search_fn)(struct btree_node *, uint64_t), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 322 | uint64_t *result_key, void *v, size_t value_size) |
| 323 | { |
| 324 | int i, r; |
| 325 | uint32_t flags, nr_entries; |
| 326 | |
| 327 | do { |
| 328 | r = ro_step(s, block); |
| 329 | if (r < 0) |
| 330 | return r; |
| 331 | |
| 332 | i = search_fn(ro_node(s), key); |
| 333 | |
| 334 | flags = le32_to_cpu(ro_node(s)->header.flags); |
| 335 | nr_entries = le32_to_cpu(ro_node(s)->header.nr_entries); |
| 336 | if (i < 0 || i >= nr_entries) |
| 337 | return -ENODATA; |
| 338 | |
| 339 | if (flags & INTERNAL_NODE) |
| 340 | block = value64(ro_node(s), i); |
| 341 | |
| 342 | } while (!(flags & LEAF_NODE)); |
| 343 | |
| 344 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 345 | memcpy(v, value_ptr(ro_node(s), i), value_size); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 346 | |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | int dm_btree_lookup(struct dm_btree_info *info, dm_block_t root, |
| 351 | uint64_t *keys, void *value_le) |
| 352 | { |
| 353 | unsigned level, last_level = info->levels - 1; |
| 354 | int r = -ENODATA; |
| 355 | uint64_t rkey; |
| 356 | __le64 internal_value_le; |
| 357 | struct ro_spine spine; |
| 358 | |
| 359 | init_ro_spine(&spine, info); |
| 360 | for (level = 0; level < info->levels; level++) { |
| 361 | size_t size; |
| 362 | void *value_p; |
| 363 | |
| 364 | if (level == last_level) { |
| 365 | value_p = value_le; |
| 366 | size = info->value_type.size; |
| 367 | |
| 368 | } else { |
| 369 | value_p = &internal_value_le; |
| 370 | size = sizeof(uint64_t); |
| 371 | } |
| 372 | |
| 373 | r = btree_lookup_raw(&spine, root, keys[level], |
| 374 | lower_bound, &rkey, |
| 375 | value_p, size); |
| 376 | |
| 377 | if (!r) { |
| 378 | if (rkey != keys[level]) { |
| 379 | exit_ro_spine(&spine); |
| 380 | return -ENODATA; |
| 381 | } |
| 382 | } else { |
| 383 | exit_ro_spine(&spine); |
| 384 | return r; |
| 385 | } |
| 386 | |
| 387 | root = le64_to_cpu(internal_value_le); |
| 388 | } |
| 389 | exit_ro_spine(&spine); |
| 390 | |
| 391 | return r; |
| 392 | } |
| 393 | EXPORT_SYMBOL_GPL(dm_btree_lookup); |
| 394 | |
| 395 | /* |
| 396 | * Splits a node by creating a sibling node and shifting half the nodes |
| 397 | * contents across. Assumes there is a parent node, and it has room for |
| 398 | * another child. |
| 399 | * |
| 400 | * Before: |
| 401 | * +--------+ |
| 402 | * | Parent | |
| 403 | * +--------+ |
| 404 | * | |
| 405 | * v |
| 406 | * +----------+ |
| 407 | * | A ++++++ | |
| 408 | * +----------+ |
| 409 | * |
| 410 | * |
| 411 | * After: |
| 412 | * +--------+ |
| 413 | * | Parent | |
| 414 | * +--------+ |
| 415 | * | | |
| 416 | * v +------+ |
| 417 | * +---------+ | |
| 418 | * | A* +++ | v |
| 419 | * +---------+ +-------+ |
| 420 | * | B +++ | |
| 421 | * +-------+ |
| 422 | * |
| 423 | * Where A* is a shadow of A. |
| 424 | */ |
Vivek Goyal | 0a8d4c3 | 2015-07-06 11:55:40 -0400 | [diff] [blame] | 425 | static int btree_split_sibling(struct shadow_spine *s, unsigned parent_index, |
| 426 | uint64_t key) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 427 | { |
| 428 | int r; |
| 429 | size_t size; |
| 430 | unsigned nr_left, nr_right; |
| 431 | struct dm_block *left, *right, *parent; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 432 | struct btree_node *ln, *rn, *pn; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 433 | __le64 location; |
| 434 | |
| 435 | left = shadow_current(s); |
| 436 | |
| 437 | r = new_block(s->info, &right); |
| 438 | if (r < 0) |
| 439 | return r; |
| 440 | |
| 441 | ln = dm_block_data(left); |
| 442 | rn = dm_block_data(right); |
| 443 | |
| 444 | nr_left = le32_to_cpu(ln->header.nr_entries) / 2; |
| 445 | nr_right = le32_to_cpu(ln->header.nr_entries) - nr_left; |
| 446 | |
| 447 | ln->header.nr_entries = cpu_to_le32(nr_left); |
| 448 | |
| 449 | rn->header.flags = ln->header.flags; |
| 450 | rn->header.nr_entries = cpu_to_le32(nr_right); |
| 451 | rn->header.max_entries = ln->header.max_entries; |
| 452 | rn->header.value_size = ln->header.value_size; |
| 453 | memcpy(rn->keys, ln->keys + nr_left, nr_right * sizeof(rn->keys[0])); |
| 454 | |
| 455 | size = le32_to_cpu(ln->header.flags) & INTERNAL_NODE ? |
| 456 | sizeof(uint64_t) : s->info->value_type.size; |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 457 | memcpy(value_ptr(rn, 0), value_ptr(ln, nr_left), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 458 | size * nr_right); |
| 459 | |
| 460 | /* |
| 461 | * Patch up the parent |
| 462 | */ |
| 463 | parent = shadow_parent(s); |
| 464 | |
| 465 | pn = dm_block_data(parent); |
| 466 | location = cpu_to_le64(dm_block_location(left)); |
| 467 | __dm_bless_for_disk(&location); |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 468 | memcpy_disk(value_ptr(pn, parent_index), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 469 | &location, sizeof(__le64)); |
| 470 | |
| 471 | location = cpu_to_le64(dm_block_location(right)); |
| 472 | __dm_bless_for_disk(&location); |
| 473 | |
| 474 | r = insert_at(sizeof(__le64), pn, parent_index + 1, |
| 475 | le64_to_cpu(rn->keys[0]), &location); |
| 476 | if (r) |
| 477 | return r; |
| 478 | |
| 479 | if (key < le64_to_cpu(rn->keys[0])) { |
| 480 | unlock_block(s->info, right); |
| 481 | s->nodes[1] = left; |
| 482 | } else { |
| 483 | unlock_block(s->info, left); |
| 484 | s->nodes[1] = right; |
| 485 | } |
| 486 | |
| 487 | return 0; |
| 488 | } |
| 489 | |
| 490 | /* |
| 491 | * Splits a node by creating two new children beneath the given node. |
| 492 | * |
| 493 | * Before: |
| 494 | * +----------+ |
| 495 | * | A ++++++ | |
| 496 | * +----------+ |
| 497 | * |
| 498 | * |
| 499 | * After: |
| 500 | * +------------+ |
| 501 | * | A (shadow) | |
| 502 | * +------------+ |
| 503 | * | | |
| 504 | * +------+ +----+ |
| 505 | * | | |
| 506 | * v v |
| 507 | * +-------+ +-------+ |
| 508 | * | B +++ | | C +++ | |
| 509 | * +-------+ +-------+ |
| 510 | */ |
| 511 | static int btree_split_beneath(struct shadow_spine *s, uint64_t key) |
| 512 | { |
| 513 | int r; |
| 514 | size_t size; |
| 515 | unsigned nr_left, nr_right; |
| 516 | struct dm_block *left, *right, *new_parent; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 517 | struct btree_node *pn, *ln, *rn; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 518 | __le64 val; |
| 519 | |
| 520 | new_parent = shadow_current(s); |
| 521 | |
| 522 | r = new_block(s->info, &left); |
| 523 | if (r < 0) |
| 524 | return r; |
| 525 | |
| 526 | r = new_block(s->info, &right); |
| 527 | if (r < 0) { |
Mike Snitzer | 4dcb8b5 | 2015-10-22 10:56:40 -0400 | [diff] [blame] | 528 | unlock_block(s->info, left); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 529 | return r; |
| 530 | } |
| 531 | |
| 532 | pn = dm_block_data(new_parent); |
| 533 | ln = dm_block_data(left); |
| 534 | rn = dm_block_data(right); |
| 535 | |
| 536 | nr_left = le32_to_cpu(pn->header.nr_entries) / 2; |
| 537 | nr_right = le32_to_cpu(pn->header.nr_entries) - nr_left; |
| 538 | |
| 539 | ln->header.flags = pn->header.flags; |
| 540 | ln->header.nr_entries = cpu_to_le32(nr_left); |
| 541 | ln->header.max_entries = pn->header.max_entries; |
| 542 | ln->header.value_size = pn->header.value_size; |
| 543 | |
| 544 | rn->header.flags = pn->header.flags; |
| 545 | rn->header.nr_entries = cpu_to_le32(nr_right); |
| 546 | rn->header.max_entries = pn->header.max_entries; |
| 547 | rn->header.value_size = pn->header.value_size; |
| 548 | |
| 549 | memcpy(ln->keys, pn->keys, nr_left * sizeof(pn->keys[0])); |
| 550 | memcpy(rn->keys, pn->keys + nr_left, nr_right * sizeof(pn->keys[0])); |
| 551 | |
| 552 | size = le32_to_cpu(pn->header.flags) & INTERNAL_NODE ? |
| 553 | sizeof(__le64) : s->info->value_type.size; |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 554 | memcpy(value_ptr(ln, 0), value_ptr(pn, 0), nr_left * size); |
| 555 | memcpy(value_ptr(rn, 0), value_ptr(pn, nr_left), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 556 | nr_right * size); |
| 557 | |
| 558 | /* new_parent should just point to l and r now */ |
| 559 | pn->header.flags = cpu_to_le32(INTERNAL_NODE); |
| 560 | pn->header.nr_entries = cpu_to_le32(2); |
| 561 | pn->header.max_entries = cpu_to_le32( |
| 562 | calc_max_entries(sizeof(__le64), |
| 563 | dm_bm_block_size( |
| 564 | dm_tm_get_bm(s->info->tm)))); |
| 565 | pn->header.value_size = cpu_to_le32(sizeof(__le64)); |
| 566 | |
| 567 | val = cpu_to_le64(dm_block_location(left)); |
| 568 | __dm_bless_for_disk(&val); |
| 569 | pn->keys[0] = ln->keys[0]; |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 570 | memcpy_disk(value_ptr(pn, 0), &val, sizeof(__le64)); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 571 | |
| 572 | val = cpu_to_le64(dm_block_location(right)); |
| 573 | __dm_bless_for_disk(&val); |
| 574 | pn->keys[1] = rn->keys[0]; |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 575 | memcpy_disk(value_ptr(pn, 1), &val, sizeof(__le64)); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 576 | |
| 577 | /* |
| 578 | * rejig the spine. This is ugly, since it knows too |
| 579 | * much about the spine |
| 580 | */ |
| 581 | if (s->nodes[0] != new_parent) { |
| 582 | unlock_block(s->info, s->nodes[0]); |
| 583 | s->nodes[0] = new_parent; |
| 584 | } |
| 585 | if (key < le64_to_cpu(rn->keys[0])) { |
| 586 | unlock_block(s->info, right); |
| 587 | s->nodes[1] = left; |
| 588 | } else { |
| 589 | unlock_block(s->info, left); |
| 590 | s->nodes[1] = right; |
| 591 | } |
| 592 | s->count = 2; |
| 593 | |
| 594 | return 0; |
| 595 | } |
| 596 | |
| 597 | static int btree_insert_raw(struct shadow_spine *s, dm_block_t root, |
| 598 | struct dm_btree_value_type *vt, |
| 599 | uint64_t key, unsigned *index) |
| 600 | { |
| 601 | int r, i = *index, top = 1; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 602 | struct btree_node *node; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 603 | |
| 604 | for (;;) { |
| 605 | r = shadow_step(s, root, vt); |
| 606 | if (r < 0) |
| 607 | return r; |
| 608 | |
| 609 | node = dm_block_data(shadow_current(s)); |
| 610 | |
| 611 | /* |
| 612 | * We have to patch up the parent node, ugly, but I don't |
| 613 | * see a way to do this automatically as part of the spine |
| 614 | * op. |
| 615 | */ |
| 616 | if (shadow_has_parent(s) && i >= 0) { /* FIXME: second clause unness. */ |
| 617 | __le64 location = cpu_to_le64(dm_block_location(shadow_current(s))); |
| 618 | |
| 619 | __dm_bless_for_disk(&location); |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 620 | memcpy_disk(value_ptr(dm_block_data(shadow_parent(s)), i), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 621 | &location, sizeof(__le64)); |
| 622 | } |
| 623 | |
| 624 | node = dm_block_data(shadow_current(s)); |
| 625 | |
| 626 | if (node->header.nr_entries == node->header.max_entries) { |
| 627 | if (top) |
| 628 | r = btree_split_beneath(s, key); |
| 629 | else |
Vivek Goyal | 0a8d4c3 | 2015-07-06 11:55:40 -0400 | [diff] [blame] | 630 | r = btree_split_sibling(s, i, key); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 631 | |
| 632 | if (r < 0) |
| 633 | return r; |
| 634 | } |
| 635 | |
| 636 | node = dm_block_data(shadow_current(s)); |
| 637 | |
| 638 | i = lower_bound(node, key); |
| 639 | |
| 640 | if (le32_to_cpu(node->header.flags) & LEAF_NODE) |
| 641 | break; |
| 642 | |
| 643 | if (i < 0) { |
| 644 | /* change the bounds on the lowest key */ |
| 645 | node->keys[0] = cpu_to_le64(key); |
| 646 | i = 0; |
| 647 | } |
| 648 | |
| 649 | root = value64(node, i); |
| 650 | top = 0; |
| 651 | } |
| 652 | |
| 653 | if (i < 0 || le64_to_cpu(node->keys[i]) != key) |
| 654 | i++; |
| 655 | |
| 656 | *index = i; |
| 657 | return 0; |
| 658 | } |
| 659 | |
| 660 | static int insert(struct dm_btree_info *info, dm_block_t root, |
| 661 | uint64_t *keys, void *value, dm_block_t *new_root, |
| 662 | int *inserted) |
| 663 | __dm_written_to_disk(value) |
| 664 | { |
| 665 | int r, need_insert; |
| 666 | unsigned level, index = -1, last_level = info->levels - 1; |
| 667 | dm_block_t block = root; |
| 668 | struct shadow_spine spine; |
Mikulas Patocka | 550929f | 2012-12-21 20:23:30 +0000 | [diff] [blame] | 669 | struct btree_node *n; |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 670 | struct dm_btree_value_type le64_type; |
| 671 | |
Joe Thornber | b0dc3c8 | 2015-08-12 15:12:09 +0100 | [diff] [blame] | 672 | init_le64_type(info->tm, &le64_type); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 673 | init_shadow_spine(&spine, info); |
| 674 | |
| 675 | for (level = 0; level < (info->levels - 1); level++) { |
| 676 | r = btree_insert_raw(&spine, block, &le64_type, keys[level], &index); |
| 677 | if (r < 0) |
| 678 | goto bad; |
| 679 | |
| 680 | n = dm_block_data(shadow_current(&spine)); |
| 681 | need_insert = ((index >= le32_to_cpu(n->header.nr_entries)) || |
| 682 | (le64_to_cpu(n->keys[index]) != keys[level])); |
| 683 | |
| 684 | if (need_insert) { |
| 685 | dm_block_t new_tree; |
| 686 | __le64 new_le; |
| 687 | |
| 688 | r = dm_btree_empty(info, &new_tree); |
| 689 | if (r < 0) |
| 690 | goto bad; |
| 691 | |
| 692 | new_le = cpu_to_le64(new_tree); |
| 693 | __dm_bless_for_disk(&new_le); |
| 694 | |
| 695 | r = insert_at(sizeof(uint64_t), n, index, |
| 696 | keys[level], &new_le); |
| 697 | if (r) |
| 698 | goto bad; |
| 699 | } |
| 700 | |
| 701 | if (level < last_level) |
| 702 | block = value64(n, index); |
| 703 | } |
| 704 | |
| 705 | r = btree_insert_raw(&spine, block, &info->value_type, |
| 706 | keys[level], &index); |
| 707 | if (r < 0) |
| 708 | goto bad; |
| 709 | |
| 710 | n = dm_block_data(shadow_current(&spine)); |
| 711 | need_insert = ((index >= le32_to_cpu(n->header.nr_entries)) || |
| 712 | (le64_to_cpu(n->keys[index]) != keys[level])); |
| 713 | |
| 714 | if (need_insert) { |
| 715 | if (inserted) |
| 716 | *inserted = 1; |
| 717 | |
| 718 | r = insert_at(info->value_type.size, n, index, |
| 719 | keys[level], value); |
| 720 | if (r) |
| 721 | goto bad_unblessed; |
| 722 | } else { |
| 723 | if (inserted) |
| 724 | *inserted = 0; |
| 725 | |
| 726 | if (info->value_type.dec && |
| 727 | (!info->value_type.equal || |
| 728 | !info->value_type.equal( |
| 729 | info->value_type.context, |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 730 | value_ptr(n, index), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 731 | value))) { |
| 732 | info->value_type.dec(info->value_type.context, |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 733 | value_ptr(n, index)); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 734 | } |
Joe Thornber | a3aefb3 | 2012-03-28 18:41:25 +0100 | [diff] [blame] | 735 | memcpy_disk(value_ptr(n, index), |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 736 | value, info->value_type.size); |
| 737 | } |
| 738 | |
| 739 | *new_root = shadow_root(&spine); |
| 740 | exit_shadow_spine(&spine); |
| 741 | |
| 742 | return 0; |
| 743 | |
| 744 | bad: |
| 745 | __dm_unbless_for_disk(value); |
| 746 | bad_unblessed: |
| 747 | exit_shadow_spine(&spine); |
| 748 | return r; |
| 749 | } |
| 750 | |
| 751 | int dm_btree_insert(struct dm_btree_info *info, dm_block_t root, |
| 752 | uint64_t *keys, void *value, dm_block_t *new_root) |
| 753 | __dm_written_to_disk(value) |
| 754 | { |
| 755 | return insert(info, root, keys, value, new_root, NULL); |
| 756 | } |
| 757 | EXPORT_SYMBOL_GPL(dm_btree_insert); |
| 758 | |
| 759 | int dm_btree_insert_notify(struct dm_btree_info *info, dm_block_t root, |
| 760 | uint64_t *keys, void *value, dm_block_t *new_root, |
| 761 | int *inserted) |
| 762 | __dm_written_to_disk(value) |
| 763 | { |
| 764 | return insert(info, root, keys, value, new_root, inserted); |
| 765 | } |
| 766 | EXPORT_SYMBOL_GPL(dm_btree_insert_notify); |
| 767 | |
| 768 | /*----------------------------------------------------------------*/ |
| 769 | |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 770 | static int find_key(struct ro_spine *s, dm_block_t block, bool find_highest, |
| 771 | uint64_t *result_key, dm_block_t *next_block) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 772 | { |
| 773 | int i, r; |
| 774 | uint32_t flags; |
| 775 | |
| 776 | do { |
| 777 | r = ro_step(s, block); |
| 778 | if (r < 0) |
| 779 | return r; |
| 780 | |
| 781 | flags = le32_to_cpu(ro_node(s)->header.flags); |
| 782 | i = le32_to_cpu(ro_node(s)->header.nr_entries); |
| 783 | if (!i) |
| 784 | return -ENODATA; |
| 785 | else |
| 786 | i--; |
| 787 | |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 788 | if (find_highest) |
| 789 | *result_key = le64_to_cpu(ro_node(s)->keys[i]); |
| 790 | else |
| 791 | *result_key = le64_to_cpu(ro_node(s)->keys[0]); |
| 792 | |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 793 | if (next_block || flags & INTERNAL_NODE) |
| 794 | block = value64(ro_node(s), i); |
| 795 | |
| 796 | } while (flags & INTERNAL_NODE); |
| 797 | |
| 798 | if (next_block) |
| 799 | *next_block = block; |
| 800 | return 0; |
| 801 | } |
| 802 | |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 803 | static int dm_btree_find_key(struct dm_btree_info *info, dm_block_t root, |
| 804 | bool find_highest, uint64_t *result_keys) |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 805 | { |
| 806 | int r = 0, count = 0, level; |
| 807 | struct ro_spine spine; |
| 808 | |
| 809 | init_ro_spine(&spine, info); |
| 810 | for (level = 0; level < info->levels; level++) { |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 811 | r = find_key(&spine, root, find_highest, result_keys + level, |
| 812 | level == info->levels - 1 ? NULL : &root); |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 813 | if (r == -ENODATA) { |
| 814 | r = 0; |
| 815 | break; |
| 816 | |
| 817 | } else if (r) |
| 818 | break; |
| 819 | |
| 820 | count++; |
| 821 | } |
| 822 | exit_ro_spine(&spine); |
| 823 | |
| 824 | return r ? r : count; |
| 825 | } |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 826 | |
| 827 | int dm_btree_find_highest_key(struct dm_btree_info *info, dm_block_t root, |
| 828 | uint64_t *result_keys) |
| 829 | { |
| 830 | return dm_btree_find_key(info, root, true, result_keys); |
| 831 | } |
Joe Thornber | 3241b1d | 2011-10-31 20:19:11 +0000 | [diff] [blame] | 832 | EXPORT_SYMBOL_GPL(dm_btree_find_highest_key); |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 833 | |
Joe Thornber | f164e69 | 2013-12-20 15:41:11 +0000 | [diff] [blame] | 834 | int dm_btree_find_lowest_key(struct dm_btree_info *info, dm_block_t root, |
| 835 | uint64_t *result_keys) |
| 836 | { |
| 837 | return dm_btree_find_key(info, root, false, result_keys); |
| 838 | } |
| 839 | EXPORT_SYMBOL_GPL(dm_btree_find_lowest_key); |
| 840 | |
| 841 | /*----------------------------------------------------------------*/ |
| 842 | |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 843 | /* |
| 844 | * FIXME: We shouldn't use a recursive algorithm when we have limited stack |
| 845 | * space. Also this only works for single level trees. |
| 846 | */ |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 847 | static int walk_node(struct dm_btree_info *info, dm_block_t block, |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 848 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
| 849 | void *context) |
| 850 | { |
| 851 | int r; |
| 852 | unsigned i, nr; |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 853 | struct dm_block *node; |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 854 | struct btree_node *n; |
| 855 | uint64_t keys; |
| 856 | |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 857 | r = bn_read_lock(info, block, &node); |
| 858 | if (r) |
| 859 | return r; |
| 860 | |
| 861 | n = dm_block_data(node); |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 862 | |
| 863 | nr = le32_to_cpu(n->header.nr_entries); |
| 864 | for (i = 0; i < nr; i++) { |
| 865 | if (le32_to_cpu(n->header.flags) & INTERNAL_NODE) { |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 866 | r = walk_node(info, value64(n, i), fn, context); |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 867 | if (r) |
| 868 | goto out; |
| 869 | } else { |
| 870 | keys = le64_to_cpu(*key_ptr(n, i)); |
| 871 | r = fn(context, &keys, value_ptr(n, i)); |
| 872 | if (r) |
| 873 | goto out; |
| 874 | } |
| 875 | } |
| 876 | |
| 877 | out: |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 878 | dm_tm_unlock(info->tm, node); |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 879 | return r; |
| 880 | } |
| 881 | |
| 882 | int dm_btree_walk(struct dm_btree_info *info, dm_block_t root, |
| 883 | int (*fn)(void *context, uint64_t *keys, void *leaf), |
| 884 | void *context) |
| 885 | { |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 886 | BUG_ON(info->levels > 1); |
Joe Thornber | 9b460d3 | 2014-11-10 15:03:24 +0000 | [diff] [blame] | 887 | return walk_node(info, root, fn, context); |
Joe Thornber | 4e7f1f9 | 2013-03-01 22:45:50 +0000 | [diff] [blame] | 888 | } |
| 889 | EXPORT_SYMBOL_GPL(dm_btree_walk); |