Commit | Line | Data |
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427e5fc6 | 1 | /* |
b84de5af | 2 | * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved. |
745703c7 | 3 | * |
427e5fc6 MD |
4 | * This code is derived from software contributed to The DragonFly Project |
5 | * by Matthew Dillon <dillon@backplane.com> | |
745703c7 | 6 | * |
427e5fc6 MD |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions | |
9 | * are met: | |
745703c7 | 10 | * |
427e5fc6 MD |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. | |
13 | * 2. Redistributions in binary form must reproduce the above copyright | |
14 | * notice, this list of conditions and the following disclaimer in | |
15 | * the documentation and/or other materials provided with the | |
16 | * distribution. | |
17 | * 3. Neither the name of The DragonFly Project nor the names of its | |
18 | * contributors may be used to endorse or promote products derived | |
19 | * from this software without specific, prior written permission. | |
745703c7 | 20 | * |
427e5fc6 MD |
21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
22 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |
24 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |
25 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | |
26 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, | |
27 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
28 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED | |
29 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
30 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |
31 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
32 | * SUCH DAMAGE. | |
427e5fc6 MD |
33 | */ |
34 | ||
35 | /* | |
8cd0a023 | 36 | * HAMMER B-Tree index |
427e5fc6 MD |
37 | * |
38 | * HAMMER implements a modified B+Tree. In documentation this will | |
9944ae54 | 39 | * simply be refered to as the HAMMER B-Tree. Basically a HAMMER B-Tree |
427e5fc6 MD |
40 | * looks like a B+Tree (A B-Tree which stores its records only at the leafs |
41 | * of the tree), but adds two additional boundary elements which describe | |
42 | * the left-most and right-most element a node is able to represent. In | |
8cd0a023 | 43 | * otherwords, we have boundary elements at the two ends of a B-Tree node |
106ccd08 | 44 | * with no valid sub-tree pointer for the right-most element. |
427e5fc6 | 45 | * |
8cd0a023 | 46 | * A B-Tree internal node looks like this: |
427e5fc6 MD |
47 | * |
48 | * B N N N N N N B <-- boundary and internal elements | |
49 | * S S S S S S S <-- subtree pointers | |
50 | * | |
8cd0a023 | 51 | * A B-Tree leaf node basically looks like this: |
427e5fc6 MD |
52 | * |
53 | * L L L L L L L L <-- leaf elemenets | |
54 | * | |
8cd0a023 MD |
55 | * The radix for an internal node is 1 less then a leaf but we get a |
56 | * number of significant benefits for our troubles. | |
106ccd08 TK |
57 | * The left-hand boundary (B in the left) is integrated into the first |
58 | * element so it doesn't require 2 elements to accomodate boundaries. | |
427e5fc6 | 59 | * |
8cd0a023 MD |
60 | * The big benefit to using a B-Tree containing boundary information |
61 | * is that it is possible to cache pointers into the middle of the tree | |
62 | * and not have to start searches, insertions, OR deletions at the root | |
63 | * node. In particular, searches are able to progress in a definitive | |
64 | * direction from any point in the tree without revisting nodes. This | |
65 | * greatly improves the efficiency of many operations, most especially | |
66 | * record appends. | |
427e5fc6 | 67 | * |
8cd0a023 MD |
68 | * B-Trees also make the stacking of trees fairly straightforward. |
69 | * | |
fe7678ee MD |
70 | * INSERTIONS: A search performed with the intention of doing |
71 | * an insert will guarantee that the terminal leaf node is not full by | |
72 | * splitting full nodes. Splits occur top-down during the dive down the | |
73 | * B-Tree. | |
74 | * | |
75 | * DELETIONS: A deletion makes no attempt to proactively balance the | |
f36a9737 MD |
76 | * tree and will recursively remove nodes that become empty. If a |
77 | * deadlock occurs a deletion may not be able to remove an empty leaf. | |
78 | * Deletions never allow internal nodes to become empty (that would blow | |
79 | * up the boundaries). | |
8cd0a023 MD |
80 | */ |
81 | #include "hammer.h" | |
66325755 | 82 | |
8cd0a023 MD |
83 | static int btree_search(hammer_cursor_t cursor, int flags); |
84 | static int btree_split_internal(hammer_cursor_t cursor); | |
85 | static int btree_split_leaf(hammer_cursor_t cursor); | |
03b6feea | 86 | static int btree_remove(hammer_cursor_t cursor, int *ndelete); |
b70819e9 | 87 | static __inline int btree_node_is_full(hammer_node_ondisk_t node); |
66611793 | 88 | static int hammer_btree_mirror_propagate(hammer_cursor_t cursor, |
adf01747 | 89 | hammer_tid_t mirror_tid); |
8cd0a023 MD |
90 | static void hammer_make_separator(hammer_base_elm_t key1, |
91 | hammer_base_elm_t key2, hammer_base_elm_t dest); | |
4c038e17 | 92 | static void hammer_cursor_mirror_filter(hammer_cursor_t cursor); |
fe4fc0c0 TK |
93 | static __inline void hammer_debug_btree_elm(hammer_cursor_t cursor, |
94 | hammer_btree_elm_t elm, const char *s, int res); | |
95 | static __inline void hammer_debug_btree_parent(hammer_cursor_t cursor, | |
96 | const char *s); | |
66325755 MD |
97 | |
98 | /* | |
8cd0a023 MD |
99 | * Iterate records after a search. The cursor is iterated forwards past |
100 | * the current record until a record matching the key-range requirements | |
101 | * is found. ENOENT is returned if the iteration goes past the ending | |
745703c7 | 102 | * key. |
66325755 | 103 | * |
d26d0ae9 MD |
104 | * The iteration is inclusive of key_beg and can be inclusive or exclusive |
105 | * of key_end depending on whether HAMMER_CURSOR_END_INCLUSIVE is set. | |
66325755 | 106 | * |
eaeff70d | 107 | * When doing an as-of search (cursor->asof != 0), key_beg.create_tid |
9582c7da | 108 | * may be modified by B-Tree functions. |
d5530d22 | 109 | * |
8cd0a023 | 110 | * cursor->key_beg may or may not be modified by this function during |
d26d0ae9 MD |
111 | * the iteration. XXX future - in case of an inverted lock we may have |
112 | * to reinitiate the lookup and set key_beg to properly pick up where we | |
113 | * left off. | |
6a37e7e4 | 114 | * |
6dc17446 MD |
115 | * If HAMMER_CURSOR_ITERATE_CHECK is set it is possible that the cursor |
116 | * was reverse indexed due to being moved to a parent while unlocked, | |
117 | * and something else might have inserted an element outside the iteration | |
118 | * range. When this case occurs the iterator just keeps iterating until | |
119 | * it gets back into the iteration range (instead of asserting). | |
120 | * | |
6a37e7e4 | 121 | * NOTE! EDEADLK *CANNOT* be returned by this procedure. |
66325755 MD |
122 | */ |
123 | int | |
8cd0a023 | 124 | hammer_btree_iterate(hammer_cursor_t cursor) |
66325755 | 125 | { |
8cd0a023 MD |
126 | hammer_node_ondisk_t node; |
127 | hammer_btree_elm_t elm; | |
3e583440 | 128 | hammer_mount_t hmp; |
1d4077f7 | 129 | int error = 0; |
66325755 MD |
130 | int r; |
131 | int s; | |
132 | ||
133 | /* | |
8cd0a023 | 134 | * Skip past the current record |
66325755 | 135 | */ |
3e583440 | 136 | hmp = cursor->trans->hmp; |
8cd0a023 | 137 | node = cursor->node->ondisk; |
a89aec1b MD |
138 | if (node == NULL) |
139 | return(ENOENT); | |
745703c7 | 140 | if (cursor->index < node->count && |
c0ade690 | 141 | (cursor->flags & HAMMER_CURSOR_ATEDISK)) { |
66325755 | 142 | ++cursor->index; |
c0ade690 | 143 | } |
66325755 | 144 | |
3e583440 MD |
145 | /* |
146 | * HAMMER can wind up being cpu-bound. | |
147 | */ | |
148 | if (++hmp->check_yield > hammer_yield_check) { | |
149 | hmp->check_yield = 0; | |
150 | lwkt_user_yield(); | |
151 | } | |
152 | ||
153 | ||
8cd0a023 MD |
154 | /* |
155 | * Loop until an element is found or we are done. | |
156 | */ | |
66325755 MD |
157 | for (;;) { |
158 | /* | |
8cd0a023 MD |
159 | * We iterate up the tree and then index over one element |
160 | * while we are at the last element in the current node. | |
161 | * | |
47197d71 | 162 | * If we are at the root of the filesystem, cursor_up |
8cd0a023 MD |
163 | * returns ENOENT. |
164 | * | |
66325755 MD |
165 | * XXX this could be optimized by storing the information in |
166 | * the parent reference. | |
195c19a1 MD |
167 | * |
168 | * XXX we can lose the node lock temporarily, this could mess | |
169 | * up our scan. | |
66325755 | 170 | */ |
47637bff | 171 | ++hammer_stats_btree_iterations; |
3e583440 | 172 | hammer_flusher_clean_loose_ios(hmp); |
77fec802 | 173 | |
8cd0a023 | 174 | if (cursor->index == node->count) { |
a84a197d | 175 | if (hammer_debug_btree) { |
35a5249b TK |
176 | hkprintf("BRACKETU %016jx[%d] -> %016jx[%d] td=%p\n", |
177 | (intmax_t)cursor->node->node_offset, | |
a84a197d | 178 | cursor->index, |
35a5249b | 179 | (intmax_t)(cursor->parent ? cursor->parent->node_offset : -1), |
a84a197d MD |
180 | cursor->parent_index, |
181 | curthread); | |
182 | } | |
653fa4cd TK |
183 | KKASSERT(cursor->parent == NULL || |
184 | cursor->parent->ondisk->elms[cursor->parent_index].internal.subtree_offset == cursor->node->node_offset); | |
6a37e7e4 | 185 | error = hammer_cursor_up(cursor); |
8cd0a023 MD |
186 | if (error) |
187 | break; | |
46fe7ae1 | 188 | /* reload stale pointer */ |
8cd0a023 MD |
189 | node = cursor->node->ondisk; |
190 | KKASSERT(cursor->index != node->count); | |
2f85fa4d MD |
191 | |
192 | /* | |
193 | * If we are reblocking we want to return internal | |
1775b6a0 MD |
194 | * nodes. Note that the internal node will be |
195 | * returned multiple times, on each upward recursion | |
196 | * from its children. The caller selects which | |
197 | * revisit it cares about (usually first or last only). | |
2f85fa4d MD |
198 | */ |
199 | if (cursor->flags & HAMMER_CURSOR_REBLOCKING) { | |
200 | cursor->flags |= HAMMER_CURSOR_ATEDISK; | |
201 | return(0); | |
202 | } | |
8cd0a023 MD |
203 | ++cursor->index; |
204 | continue; | |
66325755 MD |
205 | } |
206 | ||
207 | /* | |
d26d0ae9 MD |
208 | * Check internal or leaf element. Determine if the record |
209 | * at the cursor has gone beyond the end of our range. | |
66325755 | 210 | * |
47197d71 | 211 | * We recurse down through internal nodes. |
66325755 | 212 | */ |
8cd0a023 MD |
213 | if (node->type == HAMMER_BTREE_TYPE_INTERNAL) { |
214 | elm = &node->elms[cursor->index]; | |
c82af904 | 215 | |
d26d0ae9 MD |
216 | r = hammer_btree_cmp(&cursor->key_end, &elm[0].base); |
217 | s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base); | |
b3deaf57 | 218 | if (hammer_debug_btree) { |
fe4fc0c0 TK |
219 | hammer_debug_btree_elm(cursor, elm, "BRACKETL", r); |
220 | hammer_debug_btree_elm(cursor, elm + 1, "BRACKETR", s); | |
b3deaf57 MD |
221 | } |
222 | ||
d26d0ae9 MD |
223 | if (r < 0) { |
224 | error = ENOENT; | |
225 | break; | |
66325755 | 226 | } |
fe7678ee MD |
227 | if (r == 0 && (cursor->flags & |
228 | HAMMER_CURSOR_END_INCLUSIVE) == 0) { | |
d26d0ae9 | 229 | error = ENOENT; |
8cd0a023 | 230 | break; |
d26d0ae9 | 231 | } |
6a37e7e4 MD |
232 | |
233 | /* | |
f36a9737 | 234 | * Better not be zero |
6a37e7e4 | 235 | */ |
f36a9737 MD |
236 | KKASSERT(elm->internal.subtree_offset != 0); |
237 | ||
6dc17446 MD |
238 | if (s <= 0) { |
239 | /* | |
240 | * If running the mirror filter see if we | |
241 | * can skip one or more entire sub-trees. | |
242 | * If we can we return the internal node | |
243 | * and the caller processes the skipped | |
244 | * range (see mirror_read). | |
245 | */ | |
246 | if (cursor->flags & | |
247 | HAMMER_CURSOR_MIRROR_FILTERED) { | |
248 | if (elm->internal.mirror_tid < | |
249 | cursor->cmirror->mirror_tid) { | |
250 | hammer_cursor_mirror_filter(cursor); | |
251 | return(0); | |
252 | } | |
c82af904 | 253 | } |
6dc17446 MD |
254 | } else { |
255 | /* | |
256 | * Normally it would be impossible for the | |
257 | * cursor to have gotten back-indexed, | |
258 | * but it can happen if a node is deleted | |
259 | * and the cursor is moved to its parent | |
260 | * internal node. ITERATE_CHECK will be set. | |
261 | */ | |
262 | KKASSERT(cursor->flags & | |
263 | HAMMER_CURSOR_ITERATE_CHECK); | |
11605a5c | 264 | hdkprintf("DEBUG: Caught parent seek " |
6dc17446 | 265 | "in internal iteration\n"); |
c82af904 MD |
266 | } |
267 | ||
f36a9737 MD |
268 | error = hammer_cursor_down(cursor); |
269 | if (error) | |
270 | break; | |
271 | KKASSERT(cursor->index == 0); | |
46fe7ae1 MD |
272 | /* reload stale pointer */ |
273 | node = cursor->node->ondisk; | |
fe7678ee | 274 | continue; |
d26d0ae9 MD |
275 | } else { |
276 | elm = &node->elms[cursor->index]; | |
277 | r = hammer_btree_cmp(&cursor->key_end, &elm->base); | |
b3deaf57 | 278 | if (hammer_debug_btree) { |
fe4fc0c0 | 279 | hammer_debug_btree_elm(cursor, elm, "ELEMENT", r); |
b3deaf57 | 280 | } |
d26d0ae9 MD |
281 | if (r < 0) { |
282 | error = ENOENT; | |
283 | break; | |
284 | } | |
b33e2cc0 MD |
285 | |
286 | /* | |
287 | * We support both end-inclusive and | |
288 | * end-exclusive searches. | |
289 | */ | |
290 | if (r == 0 && | |
291 | (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) { | |
292 | error = ENOENT; | |
293 | break; | |
294 | } | |
295 | ||
6dc17446 MD |
296 | /* |
297 | * If ITERATE_CHECK is set an unlocked cursor may | |
298 | * have been moved to a parent and the iterate can | |
299 | * happen upon elements that are not in the requested | |
300 | * range. | |
301 | */ | |
302 | if (cursor->flags & HAMMER_CURSOR_ITERATE_CHECK) { | |
303 | s = hammer_btree_cmp(&cursor->key_beg, | |
304 | &elm->base); | |
305 | if (s > 0) { | |
11605a5c | 306 | hdkprintf("DEBUG: Caught parent seek " |
6dc17446 MD |
307 | "in leaf iteration\n"); |
308 | ++cursor->index; | |
309 | continue; | |
310 | } | |
311 | } | |
312 | cursor->flags &= ~HAMMER_CURSOR_ITERATE_CHECK; | |
313 | ||
314 | /* | |
315 | * Return the element | |
316 | */ | |
fe7678ee MD |
317 | switch(elm->leaf.base.btype) { |
318 | case HAMMER_BTREE_TYPE_RECORD: | |
319 | if ((cursor->flags & HAMMER_CURSOR_ASOF) && | |
320 | hammer_btree_chkts(cursor->asof, &elm->base)) { | |
321 | ++cursor->index; | |
322 | continue; | |
323 | } | |
1d4077f7 | 324 | error = 0; |
fe7678ee | 325 | break; |
fe7678ee MD |
326 | default: |
327 | error = EINVAL; | |
328 | break; | |
d26d0ae9 | 329 | } |
fe7678ee MD |
330 | if (error) |
331 | break; | |
66325755 MD |
332 | } |
333 | ||
334 | /* | |
d26d0ae9 | 335 | * Return entry |
66325755 | 336 | */ |
b3deaf57 | 337 | if (hammer_debug_btree) { |
fe4fc0c0 TK |
338 | elm = &cursor->node->ondisk->elms[cursor->index]; |
339 | hammer_debug_btree_elm(cursor, elm, "ITERATE", 0xffff); | |
b3deaf57 | 340 | } |
d26d0ae9 | 341 | return(0); |
427e5fc6 | 342 | } |
66325755 | 343 | return(error); |
427e5fc6 MD |
344 | } |
345 | ||
4c038e17 MD |
346 | /* |
347 | * We hit an internal element that we could skip as part of a mirroring | |
348 | * scan. Calculate the entire range being skipped. | |
349 | * | |
350 | * It is important to include any gaps between the parent's left_bound | |
351 | * and the node's left_bound, and same goes for the right side. | |
352 | */ | |
353 | static void | |
354 | hammer_cursor_mirror_filter(hammer_cursor_t cursor) | |
355 | { | |
356 | struct hammer_cmirror *cmirror; | |
357 | hammer_node_ondisk_t ondisk; | |
358 | hammer_btree_elm_t elm; | |
359 | ||
360 | ondisk = cursor->node->ondisk; | |
361 | cmirror = cursor->cmirror; | |
362 | ||
363 | /* | |
364 | * Calculate the skipped range | |
365 | */ | |
366 | elm = &ondisk->elms[cursor->index]; | |
367 | if (cursor->index == 0) | |
368 | cmirror->skip_beg = *cursor->left_bound; | |
369 | else | |
370 | cmirror->skip_beg = elm->internal.base; | |
371 | while (cursor->index < ondisk->count) { | |
372 | if (elm->internal.mirror_tid >= cmirror->mirror_tid) | |
373 | break; | |
374 | ++cursor->index; | |
375 | ++elm; | |
376 | } | |
377 | if (cursor->index == ondisk->count) | |
378 | cmirror->skip_end = *cursor->right_bound; | |
379 | else | |
380 | cmirror->skip_end = elm->internal.base; | |
381 | ||
382 | /* | |
383 | * clip the returned result. | |
384 | */ | |
385 | if (hammer_btree_cmp(&cmirror->skip_beg, &cursor->key_beg) < 0) | |
386 | cmirror->skip_beg = cursor->key_beg; | |
387 | if (hammer_btree_cmp(&cmirror->skip_end, &cursor->key_end) > 0) | |
388 | cmirror->skip_end = cursor->key_end; | |
389 | } | |
390 | ||
32c90105 MD |
391 | /* |
392 | * Iterate in the reverse direction. This is used by the pruning code to | |
393 | * avoid overlapping records. | |
394 | */ | |
395 | int | |
396 | hammer_btree_iterate_reverse(hammer_cursor_t cursor) | |
397 | { | |
398 | hammer_node_ondisk_t node; | |
399 | hammer_btree_elm_t elm; | |
bb5add8c | 400 | hammer_mount_t hmp; |
f75df937 | 401 | int error = 0; |
32c90105 MD |
402 | int r; |
403 | int s; | |
404 | ||
4c038e17 MD |
405 | /* mirror filtering not supported for reverse iteration */ |
406 | KKASSERT ((cursor->flags & HAMMER_CURSOR_MIRROR_FILTERED) == 0); | |
407 | ||
32c90105 MD |
408 | /* |
409 | * Skip past the current record. For various reasons the cursor | |
410 | * may end up set to -1 or set to point at the end of the current | |
411 | * node. These cases must be addressed. | |
412 | */ | |
413 | node = cursor->node->ondisk; | |
414 | if (node == NULL) | |
415 | return(ENOENT); | |
745703c7 | 416 | if (cursor->index != -1 && |
32c90105 MD |
417 | (cursor->flags & HAMMER_CURSOR_ATEDISK)) { |
418 | --cursor->index; | |
419 | } | |
420 | if (cursor->index == cursor->node->ondisk->count) | |
421 | --cursor->index; | |
422 | ||
bb5add8c MD |
423 | /* |
424 | * HAMMER can wind up being cpu-bound. | |
425 | */ | |
426 | hmp = cursor->trans->hmp; | |
427 | if (++hmp->check_yield > hammer_yield_check) { | |
428 | hmp->check_yield = 0; | |
429 | lwkt_user_yield(); | |
430 | } | |
431 | ||
32c90105 MD |
432 | /* |
433 | * Loop until an element is found or we are done. | |
434 | */ | |
435 | for (;;) { | |
77fec802 | 436 | ++hammer_stats_btree_iterations; |
bb5add8c | 437 | hammer_flusher_clean_loose_ios(hmp); |
77fec802 | 438 | |
32c90105 MD |
439 | /* |
440 | * We iterate up the tree and then index over one element | |
441 | * while we are at the last element in the current node. | |
32c90105 MD |
442 | */ |
443 | if (cursor->index == -1) { | |
444 | error = hammer_cursor_up(cursor); | |
445 | if (error) { | |
446 | cursor->index = 0; /* sanity */ | |
447 | break; | |
448 | } | |
449 | /* reload stale pointer */ | |
450 | node = cursor->node->ondisk; | |
451 | KKASSERT(cursor->index != node->count); | |
452 | --cursor->index; | |
453 | continue; | |
454 | } | |
455 | ||
456 | /* | |
457 | * Check internal or leaf element. Determine if the record | |
458 | * at the cursor has gone beyond the end of our range. | |
459 | * | |
745703c7 | 460 | * We recurse down through internal nodes. |
32c90105 MD |
461 | */ |
462 | KKASSERT(cursor->index != node->count); | |
463 | if (node->type == HAMMER_BTREE_TYPE_INTERNAL) { | |
464 | elm = &node->elms[cursor->index]; | |
7c682412 | 465 | |
32c90105 MD |
466 | r = hammer_btree_cmp(&cursor->key_end, &elm[0].base); |
467 | s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base); | |
468 | if (hammer_debug_btree) { | |
fe4fc0c0 TK |
469 | hammer_debug_btree_elm(cursor, elm, "BRACKETL", r); |
470 | hammer_debug_btree_elm(cursor, elm + 1, "BRACKETR", s); | |
32c90105 MD |
471 | } |
472 | ||
473 | if (s >= 0) { | |
474 | error = ENOENT; | |
475 | break; | |
476 | } | |
6dc17446 MD |
477 | |
478 | /* | |
479 | * It shouldn't be possible to be seeked past key_end, | |
480 | * even if the cursor got moved to a parent. | |
481 | */ | |
32c90105 MD |
482 | KKASSERT(r >= 0); |
483 | ||
484 | /* | |
f36a9737 | 485 | * Better not be zero |
32c90105 | 486 | */ |
f36a9737 MD |
487 | KKASSERT(elm->internal.subtree_offset != 0); |
488 | ||
489 | error = hammer_cursor_down(cursor); | |
490 | if (error) | |
491 | break; | |
492 | KKASSERT(cursor->index == 0); | |
32c90105 MD |
493 | /* reload stale pointer */ |
494 | node = cursor->node->ondisk; | |
f36a9737 MD |
495 | |
496 | /* this can assign -1 if the leaf was empty */ | |
497 | cursor->index = node->count - 1; | |
32c90105 MD |
498 | continue; |
499 | } else { | |
500 | elm = &node->elms[cursor->index]; | |
501 | s = hammer_btree_cmp(&cursor->key_beg, &elm->base); | |
502 | if (hammer_debug_btree) { | |
fe4fc0c0 | 503 | hammer_debug_btree_elm(cursor, elm, "ELEMENTR", s); |
32c90105 MD |
504 | } |
505 | if (s > 0) { | |
506 | error = ENOENT; | |
507 | break; | |
508 | } | |
509 | ||
6dc17446 MD |
510 | /* |
511 | * It shouldn't be possible to be seeked past key_end, | |
512 | * even if the cursor got moved to a parent. | |
513 | */ | |
514 | cursor->flags &= ~HAMMER_CURSOR_ITERATE_CHECK; | |
515 | ||
516 | /* | |
517 | * Return the element | |
518 | */ | |
32c90105 MD |
519 | switch(elm->leaf.base.btype) { |
520 | case HAMMER_BTREE_TYPE_RECORD: | |
521 | if ((cursor->flags & HAMMER_CURSOR_ASOF) && | |
522 | hammer_btree_chkts(cursor->asof, &elm->base)) { | |
523 | --cursor->index; | |
524 | continue; | |
525 | } | |
f75df937 | 526 | error = 0; |
32c90105 | 527 | break; |
32c90105 MD |
528 | default: |
529 | error = EINVAL; | |
530 | break; | |
531 | } | |
532 | if (error) | |
533 | break; | |
534 | } | |
32c90105 MD |
535 | |
536 | /* | |
537 | * Return entry | |
538 | */ | |
539 | if (hammer_debug_btree) { | |
fe4fc0c0 TK |
540 | elm = &cursor->node->ondisk->elms[cursor->index]; |
541 | hammer_debug_btree_elm(cursor, elm, "ITERATER", 0xffff); | |
32c90105 MD |
542 | } |
543 | return(0); | |
544 | } | |
545 | return(error); | |
546 | } | |
547 | ||
427e5fc6 | 548 | /* |
8cd0a023 | 549 | * Lookup cursor->key_beg. 0 is returned on success, ENOENT if the entry |
6a37e7e4 MD |
550 | * could not be found, EDEADLK if inserting and a retry is needed, and a |
551 | * fatal error otherwise. When retrying, the caller must terminate the | |
eaeff70d | 552 | * cursor and reinitialize it. EDEADLK cannot be returned if not inserting. |
745703c7 | 553 | * |
8cd0a023 | 554 | * The cursor is suitably positioned for a deletion on success, and suitably |
eaeff70d MD |
555 | * positioned for an insertion on ENOENT if HAMMER_CURSOR_INSERT was |
556 | * specified. | |
427e5fc6 | 557 | * |
47197d71 | 558 | * The cursor may begin anywhere, the search will traverse the tree in |
8cd0a023 | 559 | * either direction to locate the requested element. |
eaeff70d MD |
560 | * |
561 | * Most of the logic implementing historical searches is handled here. We | |
9582c7da MD |
562 | * do an initial lookup with create_tid set to the asof TID. Due to the |
563 | * way records are laid out, a backwards iteration may be required if | |
eaeff70d MD |
564 | * ENOENT is returned to locate the historical record. Here's the |
565 | * problem: | |
566 | * | |
9582c7da | 567 | * create_tid: 10 15 20 |
eaeff70d MD |
568 | * LEAF1 LEAF2 |
569 | * records: (11) (18) | |
570 | * | |
9582c7da MD |
571 | * Lets say we want to do a lookup AS-OF timestamp 17. We will traverse |
572 | * LEAF2 but the only record in LEAF2 has a create_tid of 18, which is | |
573 | * not visible and thus causes ENOENT to be returned. We really need | |
574 | * to check record 11 in LEAF1. If it also fails then the search fails | |
575 | * (e.g. it might represent the range 11-16 and thus still not match our | |
f36a9737 MD |
576 | * AS-OF timestamp of 17). Note that LEAF1 could be empty, requiring |
577 | * further iterations. | |
b33e2cc0 | 578 | * |
9582c7da MD |
579 | * If this case occurs btree_search() will set HAMMER_CURSOR_CREATE_CHECK |
580 | * and the cursor->create_check TID if an iteration might be needed. | |
581 | * In the above example create_check would be set to 14. | |
427e5fc6 MD |
582 | */ |
583 | int | |
8cd0a023 | 584 | hammer_btree_lookup(hammer_cursor_t cursor) |
427e5fc6 | 585 | { |
66325755 MD |
586 | int error; |
587 | ||
6dc17446 | 588 | cursor->flags &= ~HAMMER_CURSOR_ITERATE_CHECK; |
98da6d8c MD |
589 | KKASSERT ((cursor->flags & HAMMER_CURSOR_INSERT) == 0 || |
590 | cursor->trans->sync_lock_refs > 0); | |
cb51be26 | 591 | ++hammer_stats_btree_lookups; |
d5530d22 | 592 | if (cursor->flags & HAMMER_CURSOR_ASOF) { |
eaeff70d | 593 | KKASSERT((cursor->flags & HAMMER_CURSOR_INSERT) == 0); |
9582c7da | 594 | cursor->key_beg.create_tid = cursor->asof; |
eaeff70d | 595 | for (;;) { |
9582c7da | 596 | cursor->flags &= ~HAMMER_CURSOR_CREATE_CHECK; |
d5530d22 | 597 | error = btree_search(cursor, 0); |
b33e2cc0 | 598 | if (error != ENOENT || |
9582c7da | 599 | (cursor->flags & HAMMER_CURSOR_CREATE_CHECK) == 0) { |
b33e2cc0 MD |
600 | /* |
601 | * Stop if no error. | |
602 | * Stop if error other then ENOENT. | |
603 | * Stop if ENOENT and not special case. | |
604 | */ | |
eaeff70d MD |
605 | break; |
606 | } | |
32c90105 | 607 | if (hammer_debug_btree) { |
35a5249b TK |
608 | hkprintf("CREATE_CHECK %016jx\n", |
609 | (intmax_t)cursor->create_check); | |
32c90105 | 610 | } |
9582c7da | 611 | cursor->key_beg.create_tid = cursor->create_check; |
eaeff70d MD |
612 | /* loop */ |
613 | } | |
d5530d22 MD |
614 | } else { |
615 | error = btree_search(cursor, 0); | |
616 | } | |
bf3b416b | 617 | if (error == 0) |
8cd0a023 | 618 | error = hammer_btree_extract(cursor, cursor->flags); |
66325755 MD |
619 | return(error); |
620 | } | |
621 | ||
d26d0ae9 MD |
622 | /* |
623 | * Execute the logic required to start an iteration. The first record | |
624 | * located within the specified range is returned and iteration control | |
625 | * flags are adjusted for successive hammer_btree_iterate() calls. | |
3214ade6 MD |
626 | * |
627 | * Set ATEDISK so a low-level caller can call btree_first/btree_iterate | |
628 | * in a loop without worrying about it. Higher-level merged searches will | |
629 | * adjust the flag appropriately. | |
d26d0ae9 MD |
630 | */ |
631 | int | |
632 | hammer_btree_first(hammer_cursor_t cursor) | |
633 | { | |
634 | int error; | |
635 | ||
636 | error = hammer_btree_lookup(cursor); | |
637 | if (error == ENOENT) { | |
638 | cursor->flags &= ~HAMMER_CURSOR_ATEDISK; | |
639 | error = hammer_btree_iterate(cursor); | |
640 | } | |
641 | cursor->flags |= HAMMER_CURSOR_ATEDISK; | |
642 | return(error); | |
643 | } | |
644 | ||
32c90105 MD |
645 | /* |
646 | * Similarly but for an iteration in the reverse direction. | |
814387f6 MD |
647 | * |
648 | * Set ATEDISK when iterating backwards to skip the current entry, | |
649 | * which after an ENOENT lookup will be pointing beyond our end point. | |
3214ade6 MD |
650 | * |
651 | * Set ATEDISK so a low-level caller can call btree_last/btree_iterate_reverse | |
652 | * in a loop without worrying about it. Higher-level merged searches will | |
653 | * adjust the flag appropriately. | |
32c90105 MD |
654 | */ |
655 | int | |
656 | hammer_btree_last(hammer_cursor_t cursor) | |
657 | { | |
658 | struct hammer_base_elm save; | |
659 | int error; | |
660 | ||
661 | save = cursor->key_beg; | |
662 | cursor->key_beg = cursor->key_end; | |
663 | error = hammer_btree_lookup(cursor); | |
664 | cursor->key_beg = save; | |
665 | if (error == ENOENT || | |
666 | (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) { | |
814387f6 | 667 | cursor->flags |= HAMMER_CURSOR_ATEDISK; |
32c90105 MD |
668 | error = hammer_btree_iterate_reverse(cursor); |
669 | } | |
670 | cursor->flags |= HAMMER_CURSOR_ATEDISK; | |
671 | return(error); | |
672 | } | |
673 | ||
8cd0a023 MD |
674 | /* |
675 | * Extract the record and/or data associated with the cursor's current | |
676 | * position. Any prior record or data stored in the cursor is replaced. | |
8cd0a023 | 677 | * |
47197d71 | 678 | * NOTE: All extractions occur at the leaf of the B-Tree. |
8cd0a023 | 679 | */ |
66325755 | 680 | int |
8cd0a023 | 681 | hammer_btree_extract(hammer_cursor_t cursor, int flags) |
66325755 | 682 | { |
8cd0a023 MD |
683 | hammer_node_ondisk_t node; |
684 | hammer_btree_elm_t elm; | |
47197d71 | 685 | hammer_off_t data_off; |
bac808fe | 686 | hammer_mount_t hmp; |
19619882 | 687 | int32_t data_len; |
427e5fc6 | 688 | int error; |
427e5fc6 | 689 | |
b961cdbb MD |
690 | /* |
691 | * Certain types of corruption can result in a NULL node pointer. | |
692 | */ | |
693 | if (cursor->node == NULL) { | |
d053aa8a | 694 | hkprintf("NULL cursor->node, filesystem might " |
b961cdbb MD |
695 | "have gotten corrupted\n"); |
696 | return (EINVAL); | |
697 | } | |
698 | ||
8cd0a023 | 699 | /* |
427e5fc6 MD |
700 | * The case where the data reference resolves to the same buffer |
701 | * as the record reference must be handled. | |
702 | */ | |
8cd0a023 | 703 | node = cursor->node->ondisk; |
8cd0a023 | 704 | elm = &node->elms[cursor->index]; |
40043e7f MD |
705 | cursor->data = NULL; |
706 | hmp = cursor->node->hmp; | |
66325755 | 707 | |
d26d0ae9 | 708 | /* |
fe7678ee | 709 | * There is nothing to extract for an internal element. |
d26d0ae9 | 710 | */ |
fe7678ee MD |
711 | if (node->type == HAMMER_BTREE_TYPE_INTERNAL) |
712 | return(EINVAL); | |
713 | ||
47197d71 MD |
714 | /* |
715 | * Only record types have data. | |
716 | */ | |
fe7678ee | 717 | KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF); |
11ad5ade | 718 | cursor->leaf = &elm->leaf; |
4a2796f3 | 719 | |
c11c5877 TK |
720 | /* |
721 | * Returns here unless HAMMER_CURSOR_GET_DATA is set. | |
722 | */ | |
4a2796f3 MD |
723 | if ((flags & HAMMER_CURSOR_GET_DATA) == 0) |
724 | return(0); | |
c11c5877 | 725 | |
47197d71 | 726 | if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD) |
c9d1310c | 727 | return(EINVAL); |
47197d71 | 728 | data_off = elm->leaf.data_offset; |
19619882 | 729 | data_len = elm->leaf.data_len; |
47197d71 | 730 | if (data_off == 0) |
4a2796f3 | 731 | return(0); |
d26d0ae9 | 732 | |
4a2796f3 MD |
733 | /* |
734 | * Load the data | |
735 | */ | |
736 | KKASSERT(data_len >= 0 && data_len <= HAMMER_XBUFSIZE); | |
737 | cursor->data = hammer_bread_ext(hmp, data_off, data_len, | |
738 | &error, &cursor->data_buffer); | |
b8a41159 MD |
739 | |
740 | /* | |
741 | * Mark the data buffer as not being meta-data if it isn't | |
742 | * meta-data (sometimes bulk data is accessed via a volume | |
743 | * block device). | |
744 | */ | |
745 | if (error == 0) { | |
746 | switch(elm->leaf.base.rec_type) { | |
747 | case HAMMER_RECTYPE_DATA: | |
748 | case HAMMER_RECTYPE_DB: | |
18bee4a2 MD |
749 | if ((data_off & HAMMER_ZONE_LARGE_DATA) == 0) |
750 | break; | |
751 | if (hammer_double_buffer == 0 || | |
752 | (cursor->flags & HAMMER_CURSOR_NOSWAPCACHE)) { | |
753 | hammer_io_notmeta(cursor->data_buffer); | |
754 | } | |
b8a41159 MD |
755 | break; |
756 | default: | |
757 | break; | |
758 | } | |
759 | } | |
760 | ||
761 | /* | |
762 | * Deal with CRC errors on the extracted data. | |
763 | */ | |
2faf0737 | 764 | if (error == 0 && |
4c09d9c4 | 765 | hammer_crc_test_leaf(hmp->version, cursor->data, &elm->leaf) == 0) { |
35a5249b TK |
766 | hdkprintf("CRC DATA @ %016jx/%d FAILED\n", |
767 | (intmax_t)elm->leaf.data_offset, elm->leaf.data_len); | |
fc73edd8 | 768 | if (hammer_debug_critical) |
4c286c36 MD |
769 | Debugger("CRC FAILED: DATA"); |
770 | if (cursor->trans->flags & HAMMER_TRANSF_CRCDOM) | |
771 | error = EDOM; /* less critical (mirroring) */ | |
772 | else | |
773 | error = EIO; /* critical */ | |
e469566b | 774 | } |
427e5fc6 MD |
775 | return(error); |
776 | } | |
777 | ||
778 | ||
779 | /* | |
8cd0a023 MD |
780 | * Insert a leaf element into the B-Tree at the current cursor position. |
781 | * The cursor is positioned such that the element at and beyond the cursor | |
782 | * are shifted to make room for the new record. | |
783 | * | |
a89aec1b | 784 | * The caller must call hammer_btree_lookup() with the HAMMER_CURSOR_INSERT |
8cd0a023 | 785 | * flag set and that call must return ENOENT before this function can be |
2f49d4c5 | 786 | * called. ENOSPC is returned if there is no room to insert a new record. |
8cd0a023 | 787 | * |
d36ec43b | 788 | * The caller may depend on the cursor's exclusive lock after return to |
1f07f686 | 789 | * interlock frontend visibility (see HAMMER_RECF_CONVERT_DELETE). |
427e5fc6 MD |
790 | */ |
791 | int | |
602c6cb8 MD |
792 | hammer_btree_insert(hammer_cursor_t cursor, hammer_btree_leaf_elm_t elm, |
793 | int *doprop) | |
427e5fc6 | 794 | { |
8cd0a023 | 795 | hammer_node_ondisk_t node; |
427e5fc6 | 796 | int i; |
6a37e7e4 MD |
797 | int error; |
798 | ||
602c6cb8 | 799 | *doprop = 0; |
7bc5b8c2 | 800 | if ((error = hammer_cursor_upgrade_node(cursor)) != 0) |
6a37e7e4 | 801 | return(error); |
cb51be26 | 802 | ++hammer_stats_btree_inserts; |
427e5fc6 | 803 | |
427e5fc6 MD |
804 | /* |
805 | * Insert the element at the leaf node and update the count in the | |
806 | * parent. It is possible for parent to be NULL, indicating that | |
47197d71 MD |
807 | * the filesystem's ROOT B-Tree node is a leaf itself, which is |
808 | * possible. The root inode can never be deleted so the leaf should | |
809 | * never be empty. | |
427e5fc6 | 810 | * |
2f49d4c5 | 811 | * Remember that leaf nodes do not have boundaries. |
427e5fc6 | 812 | */ |
36f82b23 | 813 | hammer_modify_node_all(cursor->trans, cursor->node); |
8cd0a023 | 814 | node = cursor->node->ondisk; |
427e5fc6 | 815 | i = cursor->index; |
fe7678ee | 816 | KKASSERT(elm->base.btype != 0); |
8cd0a023 MD |
817 | KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF); |
818 | KKASSERT(node->count < HAMMER_BTREE_LEAF_ELMS); | |
819 | if (i != node->count) { | |
820 | bcopy(&node->elms[i], &node->elms[i+1], | |
821 | (node->count - i) * sizeof(*elm)); | |
822 | } | |
11ad5ade | 823 | node->elms[i].leaf = *elm; |
8cd0a023 | 824 | ++node->count; |
e4a5ff06 | 825 | hammer_cursor_inserted_element(cursor->node, i); |
c82af904 MD |
826 | |
827 | /* | |
828 | * Update the leaf node's aggregate mirror_tid for mirroring | |
829 | * support. | |
830 | */ | |
602c6cb8 | 831 | if (node->mirror_tid < elm->base.delete_tid) { |
c82af904 | 832 | node->mirror_tid = elm->base.delete_tid; |
602c6cb8 MD |
833 | *doprop = 1; |
834 | } | |
835 | if (node->mirror_tid < elm->base.create_tid) { | |
c82af904 | 836 | node->mirror_tid = elm->base.create_tid; |
602c6cb8 | 837 | *doprop = 1; |
c82af904 | 838 | } |
602c6cb8 | 839 | hammer_modify_node_done(cursor->node); |
c82af904 | 840 | |
eaeff70d | 841 | /* |
47197d71 | 842 | * Debugging sanity checks. |
eaeff70d | 843 | */ |
11ad5ade MD |
844 | KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->base) <= 0); |
845 | KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->base) > 0); | |
eaeff70d | 846 | if (i) { |
11ad5ade | 847 | KKASSERT(hammer_btree_cmp(&node->elms[i-1].leaf.base, &elm->base) < 0); |
eaeff70d | 848 | } |
b3deaf57 | 849 | if (i != node->count - 1) |
11ad5ade | 850 | KKASSERT(hammer_btree_cmp(&node->elms[i+1].leaf.base, &elm->base) > 0); |
b3deaf57 | 851 | |
427e5fc6 MD |
852 | return(0); |
853 | } | |
854 | ||
855 | /* | |
fe7678ee | 856 | * Delete a record from the B-Tree at the current cursor position. |
8cd0a023 MD |
857 | * The cursor is positioned such that the current element is the one |
858 | * to be deleted. | |
859 | * | |
195c19a1 MD |
860 | * On return the cursor will be positioned after the deleted element and |
861 | * MAY point to an internal node. It will be suitable for the continuation | |
862 | * of an iteration but not for an insertion or deletion. | |
8cd0a023 | 863 | * |
195c19a1 | 864 | * Deletions will attempt to partially rebalance the B-Tree in an upward |
f36a9737 MD |
865 | * direction, but will terminate rather then deadlock. Empty internal nodes |
866 | * are never allowed by a deletion which deadlocks may end up giving us an | |
867 | * empty leaf. The pruner will clean up and rebalance the tree. | |
46fe7ae1 MD |
868 | * |
869 | * This function can return EDEADLK, requiring the caller to retry the | |
870 | * operation after clearing the deadlock. | |
03b6feea TK |
871 | * |
872 | * This function will store the number of deleted btree nodes in *ndelete | |
873 | * if ndelete is not NULL. | |
427e5fc6 MD |
874 | */ |
875 | int | |
03b6feea | 876 | hammer_btree_delete(hammer_cursor_t cursor, int *ndelete) |
427e5fc6 | 877 | { |
8cd0a023 MD |
878 | hammer_node_ondisk_t ondisk; |
879 | hammer_node_t node; | |
f31f6d84 | 880 | hammer_node_t parent __debugvar; |
8cd0a023 | 881 | int error; |
427e5fc6 MD |
882 | int i; |
883 | ||
98da6d8c | 884 | KKASSERT (cursor->trans->sync_lock_refs > 0); |
03b6feea TK |
885 | if (ndelete) |
886 | *ndelete = 0; | |
6a37e7e4 MD |
887 | if ((error = hammer_cursor_upgrade(cursor)) != 0) |
888 | return(error); | |
cb51be26 | 889 | ++hammer_stats_btree_deletes; |
6a37e7e4 | 890 | |
427e5fc6 | 891 | /* |
745703c7 | 892 | * Delete the element from the leaf node. |
427e5fc6 | 893 | * |
8cd0a023 | 894 | * Remember that leaf nodes do not have boundaries. |
427e5fc6 | 895 | */ |
8cd0a023 MD |
896 | node = cursor->node; |
897 | ondisk = node->ondisk; | |
427e5fc6 MD |
898 | i = cursor->index; |
899 | ||
8cd0a023 | 900 | KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_LEAF); |
fe7678ee | 901 | KKASSERT(i >= 0 && i < ondisk->count); |
36f82b23 | 902 | hammer_modify_node_all(cursor->trans, node); |
8cd0a023 MD |
903 | if (i + 1 != ondisk->count) { |
904 | bcopy(&ondisk->elms[i+1], &ondisk->elms[i], | |
905 | (ondisk->count - i - 1) * sizeof(ondisk->elms[0])); | |
906 | } | |
907 | --ondisk->count; | |
10a5d1ba | 908 | hammer_modify_node_done(node); |
b3bad96f | 909 | hammer_cursor_deleted_element(node, i); |
fe7678ee MD |
910 | |
911 | /* | |
912 | * Validate local parent | |
913 | */ | |
914 | if (ondisk->parent) { | |
8cd0a023 | 915 | parent = cursor->parent; |
fe7678ee MD |
916 | |
917 | KKASSERT(parent != NULL); | |
918 | KKASSERT(parent->node_offset == ondisk->parent); | |
427e5fc6 | 919 | } |
427e5fc6 | 920 | |
8cd0a023 | 921 | /* |
fe7678ee | 922 | * If the leaf becomes empty it must be detached from the parent, |
47197d71 | 923 | * potentially recursing through to the filesystem root. |
195c19a1 MD |
924 | * |
925 | * This may reposition the cursor at one of the parent's of the | |
926 | * current node. | |
6a37e7e4 MD |
927 | * |
928 | * Ignore deadlock errors, that simply means that btree_remove | |
745703c7 | 929 | * was unable to recurse and had to leave us with an empty leaf. |
8cd0a023 | 930 | */ |
b3deaf57 | 931 | KKASSERT(cursor->index <= ondisk->count); |
8cd0a023 | 932 | if (ondisk->count == 0) { |
03b6feea | 933 | error = btree_remove(cursor, ndelete); |
6a37e7e4 MD |
934 | if (error == EDEADLK) |
935 | error = 0; | |
8cd0a023 | 936 | } else { |
8cd0a023 MD |
937 | error = 0; |
938 | } | |
eaeff70d MD |
939 | KKASSERT(cursor->parent == NULL || |
940 | cursor->parent_index < cursor->parent->ondisk->count); | |
8cd0a023 MD |
941 | return(error); |
942 | } | |
427e5fc6 MD |
943 | |
944 | /* | |
2f49d4c5 | 945 | * PRIMARY B-TREE SEARCH SUPPORT PROCEDURE |
8cd0a023 | 946 | * |
47197d71 | 947 | * Search the filesystem B-Tree for cursor->key_beg, return the matching node. |
8cd0a023 | 948 | * |
d26d0ae9 MD |
949 | * The search can begin ANYWHERE in the B-Tree. As a first step the search |
950 | * iterates up the tree as necessary to properly position itself prior to | |
951 | * actually doing the sarch. | |
745703c7 | 952 | * |
8cd0a023 | 953 | * INSERTIONS: The search will split full nodes and leaves on its way down |
d26d0ae9 | 954 | * and guarentee that the leaf it ends up on is not full. If we run out |
fd1fcc1a | 955 | * of space the search continues to the leaf, but ENOSPC is returned. |
427e5fc6 | 956 | * |
fbc6e32a MD |
957 | * The search is only guarenteed to end up on a leaf if an error code of 0 |
958 | * is returned, or if inserting and an error code of ENOENT is returned. | |
d26d0ae9 | 959 | * Otherwise it can stop at an internal node. On success a search returns |
47197d71 | 960 | * a leaf node. |
eaeff70d MD |
961 | * |
962 | * COMPLEXITY WARNING! This is the core B-Tree search code for the entire | |
963 | * filesystem, and it is not simple code. Please note the following facts: | |
964 | * | |
965 | * - Internal node recursions have a boundary on the left AND right. The | |
9582c7da | 966 | * right boundary is non-inclusive. The create_tid is a generic part |
eaeff70d MD |
967 | * of the key for internal nodes. |
968 | * | |
eaeff70d | 969 | * - Filesystem lookups typically set HAMMER_CURSOR_ASOF, indicating a |
b33e2cc0 MD |
970 | * historical search. ASOF and INSERT are mutually exclusive. When |
971 | * doing an as-of lookup btree_search() checks for a right-edge boundary | |
9582c7da MD |
972 | * case. If while recursing down the left-edge differs from the key |
973 | * by ONLY its create_tid, HAMMER_CURSOR_CREATE_CHECK is set along | |
974 | * with cursor->create_check. This is used by btree_lookup() to iterate. | |
975 | * The iteration backwards because as-of searches can wind up going | |
b33e2cc0 | 976 | * down the wrong branch of the B-Tree. |
427e5fc6 | 977 | */ |
745703c7 | 978 | static |
427e5fc6 | 979 | int |
8cd0a023 | 980 | btree_search(hammer_cursor_t cursor, int flags) |
427e5fc6 | 981 | { |
8cd0a023 | 982 | hammer_node_ondisk_t node; |
61aeeb33 | 983 | hammer_btree_elm_t elm; |
8cd0a023 | 984 | int error; |
d26d0ae9 | 985 | int enospc = 0; |
8cd0a023 MD |
986 | int i; |
987 | int r; | |
b33e2cc0 | 988 | int s; |
8cd0a023 MD |
989 | |
990 | flags |= cursor->flags; | |
cb51be26 | 991 | ++hammer_stats_btree_searches; |
8cd0a023 | 992 | |
b3deaf57 | 993 | if (hammer_debug_btree) { |
fe4fc0c0 TK |
994 | hammer_debug_btree_elm(cursor, |
995 | (hammer_btree_elm_t)&cursor->key_beg, | |
996 | "SEARCH", 0xffff); | |
a84a197d | 997 | if (cursor->parent) |
fe4fc0c0 | 998 | hammer_debug_btree_parent(cursor, "SEARCHP"); |
b3deaf57 MD |
999 | } |
1000 | ||
8cd0a023 MD |
1001 | /* |
1002 | * Move our cursor up the tree until we find a node whos range covers | |
47197d71 | 1003 | * the key we are trying to locate. |
8cd0a023 MD |
1004 | * |
1005 | * The left bound is inclusive, the right bound is non-inclusive. | |
47197d71 | 1006 | * It is ok to cursor up too far. |
8cd0a023 | 1007 | */ |
b33e2cc0 MD |
1008 | for (;;) { |
1009 | r = hammer_btree_cmp(&cursor->key_beg, cursor->left_bound); | |
1010 | s = hammer_btree_cmp(&cursor->key_beg, cursor->right_bound); | |
1011 | if (r >= 0 && s < 0) | |
1012 | break; | |
9944ae54 | 1013 | KKASSERT(cursor->parent); |
cb51be26 | 1014 | ++hammer_stats_btree_iterations; |
6a37e7e4 | 1015 | error = hammer_cursor_up(cursor); |
8cd0a023 MD |
1016 | if (error) |
1017 | goto done; | |
427e5fc6 | 1018 | } |
427e5fc6 | 1019 | |
b33e2cc0 MD |
1020 | /* |
1021 | * The delete-checks below are based on node, not parent. Set the | |
1022 | * initial delete-check based on the parent. | |
1023 | */ | |
9582c7da MD |
1024 | if (r == 1) { |
1025 | KKASSERT(cursor->left_bound->create_tid != 1); | |
1026 | cursor->create_check = cursor->left_bound->create_tid - 1; | |
1027 | cursor->flags |= HAMMER_CURSOR_CREATE_CHECK; | |
b33e2cc0 MD |
1028 | } |
1029 | ||
8cd0a023 | 1030 | /* |
47197d71 | 1031 | * We better have ended up with a node somewhere. |
8cd0a023 | 1032 | */ |
47197d71 | 1033 | KKASSERT(cursor->node != NULL); |
8cd0a023 MD |
1034 | |
1035 | /* | |
1036 | * If we are inserting we can't start at a full node if the parent | |
1037 | * is also full (because there is no way to split the node), | |
b33e2cc0 | 1038 | * continue running up the tree until the requirement is satisfied |
47197d71 | 1039 | * or we hit the root of the filesystem. |
9582c7da MD |
1040 | * |
1041 | * (If inserting we aren't doing an as-of search so we don't have | |
1042 | * to worry about create_check). | |
8cd0a023 | 1043 | */ |
a9fd59b8 TK |
1044 | while (flags & HAMMER_CURSOR_INSERT) { |
1045 | if (btree_node_is_full(cursor->node->ondisk) == 0) | |
1046 | break; | |
b33e2cc0 MD |
1047 | if (cursor->node->ondisk->parent == 0 || |
1048 | cursor->parent->ondisk->count != HAMMER_BTREE_INT_ELMS) { | |
8cd0a023 | 1049 | break; |
b33e2cc0 | 1050 | } |
cb51be26 | 1051 | ++hammer_stats_btree_iterations; |
6a37e7e4 | 1052 | error = hammer_cursor_up(cursor); |
47197d71 | 1053 | /* node may have become stale */ |
8cd0a023 MD |
1054 | if (error) |
1055 | goto done; | |
427e5fc6 | 1056 | } |
427e5fc6 | 1057 | |
8cd0a023 MD |
1058 | /* |
1059 | * Push down through internal nodes to locate the requested key. | |
1060 | */ | |
8cd0a023 MD |
1061 | node = cursor->node->ondisk; |
1062 | while (node->type == HAMMER_BTREE_TYPE_INTERNAL) { | |
8cd0a023 MD |
1063 | /* |
1064 | * Scan the node to find the subtree index to push down into. | |
fbc6e32a | 1065 | * We go one-past, then back-up. |
d113fda1 | 1066 | * |
fe7678ee MD |
1067 | * We must proactively remove deleted elements which may |
1068 | * have been left over from a deadlocked btree_remove(). | |
1069 | * | |
eaeff70d | 1070 | * The left and right boundaries are included in the loop |
d5530d22 | 1071 | * in order to detect edge cases. |
9944ae54 | 1072 | * |
9582c7da | 1073 | * If the separator only differs by create_tid (r == 1) |
eaeff70d MD |
1074 | * and we are doing an as-of search, we may end up going |
1075 | * down a branch to the left of the one containing the | |
1076 | * desired key. This requires numerous special cases. | |
8cd0a023 | 1077 | */ |
47637bff | 1078 | ++hammer_stats_btree_iterations; |
46fe7ae1 | 1079 | if (hammer_debug_btree) { |
35a5249b TK |
1080 | hkprintf("SEARCH-I %016jx count=%d\n", |
1081 | (intmax_t)cursor->node->node_offset, | |
46fe7ae1 MD |
1082 | node->count); |
1083 | } | |
af209b0f MD |
1084 | |
1085 | /* | |
1086 | * Try to shortcut the search before dropping into the | |
1087 | * linear loop. Locate the first node where r <= 1. | |
1088 | */ | |
1089 | i = hammer_btree_search_node(&cursor->key_beg, node); | |
1090 | while (i <= node->count) { | |
cb51be26 | 1091 | ++hammer_stats_btree_elements; |
61aeeb33 MD |
1092 | elm = &node->elms[i]; |
1093 | r = hammer_btree_cmp(&cursor->key_beg, &elm->base); | |
b33e2cc0 | 1094 | if (hammer_debug_btree > 2) { |
33234d14 | 1095 | hkprintf(" IELM %p [%d] r=%d\n", |
b33e2cc0 MD |
1096 | &node->elms[i], i, r); |
1097 | } | |
9582c7da | 1098 | if (r < 0) |
8cd0a023 | 1099 | break; |
9582c7da MD |
1100 | if (r == 1) { |
1101 | KKASSERT(elm->base.create_tid != 1); | |
1102 | cursor->create_check = elm->base.create_tid - 1; | |
1103 | cursor->flags |= HAMMER_CURSOR_CREATE_CHECK; | |
b33e2cc0 | 1104 | } |
af209b0f | 1105 | ++i; |
8cd0a023 | 1106 | } |
eaeff70d | 1107 | if (hammer_debug_btree) { |
33234d14 | 1108 | hkprintf("SEARCH-I preI=%d/%d r=%d\n", |
46fe7ae1 | 1109 | i, node->count, r); |
eaeff70d | 1110 | } |
8cd0a023 MD |
1111 | |
1112 | /* | |
ae744f81 TK |
1113 | * The first two cases (i == 0 or i == node->count + 1) |
1114 | * occur when the parent's idea of the boundary | |
9944ae54 MD |
1115 | * is wider then the child's idea of the boundary, and |
1116 | * require special handling. If not inserting we can | |
1117 | * terminate the search early for these cases but the | |
1118 | * child's boundaries cannot be unconditionally modified. | |
ae744f81 TK |
1119 | * |
1120 | * The last case (neither of the above) fits in child's | |
1121 | * idea of the boundary, so we can simply push down the | |
1122 | * cursor. | |
8cd0a023 | 1123 | */ |
fbc6e32a | 1124 | if (i == 0) { |
9944ae54 MD |
1125 | /* |
1126 | * If i == 0 the search terminated to the LEFT of the | |
1127 | * left_boundary but to the RIGHT of the parent's left | |
1128 | * boundary. | |
1129 | */ | |
46137e17 | 1130 | uint8_t save; |
d26d0ae9 | 1131 | |
eaeff70d MD |
1132 | elm = &node->elms[0]; |
1133 | ||
1134 | /* | |
1135 | * If we aren't inserting we can stop here. | |
1136 | */ | |
11ad5ade MD |
1137 | if ((flags & (HAMMER_CURSOR_INSERT | |
1138 | HAMMER_CURSOR_PRUNING)) == 0) { | |
fbc6e32a MD |
1139 | cursor->index = 0; |
1140 | return(ENOENT); | |
1141 | } | |
9944ae54 | 1142 | |
d5530d22 MD |
1143 | /* |
1144 | * Correct a left-hand boundary mismatch. | |
6a37e7e4 | 1145 | * |
f36a9737 MD |
1146 | * We can only do this if we can upgrade the lock, |
1147 | * and synchronized as a background cursor (i.e. | |
1148 | * inserting or pruning). | |
10a5d1ba MD |
1149 | * |
1150 | * WARNING: We can only do this if inserting, i.e. | |
1151 | * we are running on the backend. | |
d5530d22 | 1152 | */ |
eaeff70d MD |
1153 | if ((error = hammer_cursor_upgrade(cursor)) != 0) |
1154 | return(error); | |
10a5d1ba | 1155 | KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND); |
c9b9e29d MD |
1156 | hammer_modify_node_field(cursor->trans, cursor->node, |
1157 | elms[0]); | |
fe7678ee | 1158 | save = node->elms[0].base.btype; |
d5530d22 | 1159 | node->elms[0].base = *cursor->left_bound; |
fe7678ee | 1160 | node->elms[0].base.btype = save; |
10a5d1ba | 1161 | hammer_modify_node_done(cursor->node); |
9944ae54 | 1162 | } else if (i == node->count + 1) { |
d26d0ae9 | 1163 | /* |
9944ae54 MD |
1164 | * If i == node->count + 1 the search terminated to |
1165 | * the RIGHT of the right boundary but to the LEFT | |
eaeff70d MD |
1166 | * of the parent's right boundary. If we aren't |
1167 | * inserting we can stop here. | |
d113fda1 | 1168 | * |
9944ae54 MD |
1169 | * Note that the last element in this case is |
1170 | * elms[i-2] prior to adjustments to 'i'. | |
d26d0ae9 | 1171 | */ |
9944ae54 | 1172 | --i; |
11ad5ade MD |
1173 | if ((flags & (HAMMER_CURSOR_INSERT | |
1174 | HAMMER_CURSOR_PRUNING)) == 0) { | |
9944ae54 | 1175 | cursor->index = i; |
eaeff70d | 1176 | return (ENOENT); |
d26d0ae9 MD |
1177 | } |
1178 | ||
d5530d22 MD |
1179 | /* |
1180 | * Correct a right-hand boundary mismatch. | |
1181 | * (actual push-down record is i-2 prior to | |
1182 | * adjustments to i). | |
6a37e7e4 | 1183 | * |
f36a9737 MD |
1184 | * We can only do this if we can upgrade the lock, |
1185 | * and synchronized as a background cursor (i.e. | |
1186 | * inserting or pruning). | |
10a5d1ba MD |
1187 | * |
1188 | * WARNING: We can only do this if inserting, i.e. | |
1189 | * we are running on the backend. | |
d5530d22 | 1190 | */ |
eaeff70d MD |
1191 | if ((error = hammer_cursor_upgrade(cursor)) != 0) |
1192 | return(error); | |
9944ae54 | 1193 | elm = &node->elms[i]; |
10a5d1ba | 1194 | KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND); |
36f82b23 MD |
1195 | hammer_modify_node(cursor->trans, cursor->node, |
1196 | &elm->base, sizeof(elm->base)); | |
d5530d22 | 1197 | elm->base = *cursor->right_bound; |
10a5d1ba | 1198 | hammer_modify_node_done(cursor->node); |
d5530d22 | 1199 | --i; |
fbc6e32a MD |
1200 | } else { |
1201 | /* | |
9944ae54 MD |
1202 | * The push-down index is now i - 1. If we had |
1203 | * terminated on the right boundary this will point | |
1204 | * us at the last element. | |
fbc6e32a MD |
1205 | */ |
1206 | --i; | |
1207 | } | |
8cd0a023 | 1208 | cursor->index = i; |
6a37e7e4 | 1209 | elm = &node->elms[i]; |
8cd0a023 | 1210 | |
b3deaf57 | 1211 | if (hammer_debug_btree) { |
fe4fc0c0 | 1212 | hammer_debug_btree_elm(cursor, elm, "RESULT-I", 0xffff); |
b3deaf57 MD |
1213 | } |
1214 | ||
6a37e7e4 | 1215 | /* |
f36a9737 | 1216 | * We better have a valid subtree offset. |
6a37e7e4 | 1217 | */ |
f36a9737 | 1218 | KKASSERT(elm->internal.subtree_offset != 0); |
6a37e7e4 | 1219 | |
8cd0a023 MD |
1220 | /* |
1221 | * Handle insertion and deletion requirements. | |
1222 | * | |
1223 | * If inserting split full nodes. The split code will | |
1224 | * adjust cursor->node and cursor->index if the current | |
1225 | * index winds up in the new node. | |
61aeeb33 | 1226 | * |
9944ae54 MD |
1227 | * If inserting and a left or right edge case was detected, |
1228 | * we cannot correct the left or right boundary and must | |
1229 | * prepend and append an empty leaf node in order to make | |
1230 | * the boundary correction. | |
1231 | * | |
fd1fcc1a TK |
1232 | * If we run out of space we set enospc but continue on |
1233 | * to a leaf. | |
8cd0a023 | 1234 | */ |
61aeeb33 | 1235 | if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) { |
fe7678ee | 1236 | if (btree_node_is_full(node)) { |
8cd0a023 | 1237 | error = btree_split_internal(cursor); |
d26d0ae9 MD |
1238 | if (error) { |
1239 | if (error != ENOSPC) | |
1240 | goto done; | |
1241 | enospc = 1; | |
d26d0ae9 | 1242 | } |
8cd0a023 MD |
1243 | /* |
1244 | * reload stale pointers | |
1245 | */ | |
1246 | i = cursor->index; | |
1247 | node = cursor->node->ondisk; | |
1248 | } | |
d26d0ae9 | 1249 | } |
427e5fc6 MD |
1250 | |
1251 | /* | |
8cd0a023 | 1252 | * Push down (push into new node, existing node becomes |
d26d0ae9 | 1253 | * the parent) and continue the search. |
427e5fc6 | 1254 | */ |
8cd0a023 | 1255 | error = hammer_cursor_down(cursor); |
47197d71 | 1256 | /* node may have become stale */ |
8cd0a023 MD |
1257 | if (error) |
1258 | goto done; | |
1259 | node = cursor->node->ondisk; | |
427e5fc6 | 1260 | } |
427e5fc6 | 1261 | |
8cd0a023 MD |
1262 | /* |
1263 | * We are at a leaf, do a linear search of the key array. | |
d26d0ae9 MD |
1264 | * |
1265 | * On success the index is set to the matching element and 0 | |
1266 | * is returned. | |
1267 | * | |
1268 | * On failure the index is set to the insertion point and ENOENT | |
1269 | * is returned. | |
8cd0a023 MD |
1270 | * |
1271 | * Boundaries are not stored in leaf nodes, so the index can wind | |
1272 | * up to the left of element 0 (index == 0) or past the end of | |
f36a9737 MD |
1273 | * the array (index == node->count). It is also possible that the |
1274 | * leaf might be empty. | |
8cd0a023 | 1275 | */ |
47637bff | 1276 | ++hammer_stats_btree_iterations; |
fe7678ee | 1277 | KKASSERT (node->type == HAMMER_BTREE_TYPE_LEAF); |
8cd0a023 | 1278 | KKASSERT(node->count <= HAMMER_BTREE_LEAF_ELMS); |
46fe7ae1 | 1279 | if (hammer_debug_btree) { |
35a5249b TK |
1280 | hkprintf("SEARCH-L %016jx count=%d\n", |
1281 | (intmax_t)cursor->node->node_offset, | |
46fe7ae1 MD |
1282 | node->count); |
1283 | } | |
8cd0a023 | 1284 | |
af209b0f MD |
1285 | /* |
1286 | * Try to shortcut the search before dropping into the | |
1287 | * linear loop. Locate the first node where r <= 1. | |
1288 | */ | |
1289 | i = hammer_btree_search_node(&cursor->key_beg, node); | |
1290 | while (i < node->count) { | |
cb51be26 | 1291 | ++hammer_stats_btree_elements; |
fe7678ee MD |
1292 | elm = &node->elms[i]; |
1293 | ||
1294 | r = hammer_btree_cmp(&cursor->key_beg, &elm->leaf.base); | |
427e5fc6 | 1295 | |
d5530d22 | 1296 | if (hammer_debug_btree > 1) |
33234d14 | 1297 | hkprintf(" LELM %p [%d] r=%d\n", &node->elms[i], i, r); |
d5530d22 | 1298 | |
427e5fc6 | 1299 | /* |
fe7678ee | 1300 | * We are at a record element. Stop if we've flipped past |
9582c7da MD |
1301 | * key_beg, not counting the create_tid test. Allow the |
1302 | * r == 1 case (key_beg > element but differs only by its | |
1303 | * create_tid) to fall through to the AS-OF check. | |
427e5fc6 | 1304 | */ |
fe7678ee MD |
1305 | KKASSERT (elm->leaf.base.btype == HAMMER_BTREE_TYPE_RECORD); |
1306 | ||
9582c7da | 1307 | if (r < 0) |
d5530d22 | 1308 | goto failed; |
af209b0f MD |
1309 | if (r > 1) { |
1310 | ++i; | |
d5530d22 | 1311 | continue; |
af209b0f | 1312 | } |
427e5fc6 | 1313 | |
66325755 | 1314 | /* |
9582c7da | 1315 | * Check our as-of timestamp against the element. |
66325755 | 1316 | */ |
eaeff70d | 1317 | if (flags & HAMMER_CURSOR_ASOF) { |
fe7678ee | 1318 | if (hammer_btree_chkts(cursor->asof, |
d113fda1 | 1319 | &node->elms[i].base) != 0) { |
af209b0f | 1320 | ++i; |
d113fda1 MD |
1321 | continue; |
1322 | } | |
eaeff70d MD |
1323 | /* success */ |
1324 | } else { | |
af209b0f MD |
1325 | if (r > 0) { /* can only be +1 */ |
1326 | ++i; | |
9582c7da | 1327 | continue; |
af209b0f | 1328 | } |
eaeff70d | 1329 | /* success */ |
66325755 | 1330 | } |
d5530d22 MD |
1331 | cursor->index = i; |
1332 | error = 0; | |
eaeff70d | 1333 | if (hammer_debug_btree) { |
35a5249b TK |
1334 | hkprintf("RESULT-L %016jx[%d] (SUCCESS)\n", |
1335 | (intmax_t)cursor->node->node_offset, i); | |
eaeff70d | 1336 | } |
d5530d22 MD |
1337 | goto done; |
1338 | } | |
1339 | ||
1340 | /* | |
eaeff70d | 1341 | * The search of the leaf node failed. i is the insertion point. |
d5530d22 | 1342 | */ |
d5530d22 | 1343 | failed: |
b3deaf57 | 1344 | if (hammer_debug_btree) { |
35a5249b TK |
1345 | hkprintf("RESULT-L %016jx[%d] (FAILED)\n", |
1346 | (intmax_t)cursor->node->node_offset, i); | |
b3deaf57 MD |
1347 | } |
1348 | ||
8cd0a023 MD |
1349 | /* |
1350 | * No exact match was found, i is now at the insertion point. | |
1351 | * | |
1352 | * If inserting split a full leaf before returning. This | |
1353 | * may have the side effect of adjusting cursor->node and | |
1354 | * cursor->index. | |
1355 | */ | |
1356 | cursor->index = i; | |
eaeff70d | 1357 | if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0 && |
47197d71 | 1358 | btree_node_is_full(node)) { |
8cd0a023 | 1359 | error = btree_split_leaf(cursor); |
d26d0ae9 MD |
1360 | if (error) { |
1361 | if (error != ENOSPC) | |
1362 | goto done; | |
1363 | enospc = 1; | |
d26d0ae9 MD |
1364 | } |
1365 | /* | |
1366 | * reload stale pointers | |
1367 | */ | |
8cd0a023 MD |
1368 | /* NOT USED |
1369 | i = cursor->index; | |
1370 | node = &cursor->node->internal; | |
1371 | */ | |
8cd0a023 | 1372 | } |
d26d0ae9 MD |
1373 | |
1374 | /* | |
1375 | * We reached a leaf but did not find the key we were looking for. | |
1376 | * If this is an insert we will be properly positioned for an insert | |
fd1fcc1a | 1377 | * (ENOENT) or unable to insert (ENOSPC). |
d26d0ae9 MD |
1378 | */ |
1379 | error = enospc ? ENOSPC : ENOENT; | |
8cd0a023 | 1380 | done: |
427e5fc6 MD |
1381 | return(error); |
1382 | } | |
1383 | ||
af209b0f MD |
1384 | /* |
1385 | * Heuristical search for the first element whos comparison is <= 1. May | |
1386 | * return an index whos compare result is > 1 but may only return an index | |
1387 | * whos compare result is <= 1 if it is the first element with that result. | |
1388 | */ | |
bcac4bbb | 1389 | int |
af209b0f MD |
1390 | hammer_btree_search_node(hammer_base_elm_t elm, hammer_node_ondisk_t node) |
1391 | { | |
1392 | int b; | |
1393 | int s; | |
1394 | int i; | |
1395 | int r; | |
1396 | ||
1397 | /* | |
1398 | * Don't bother if the node does not have very many elements | |
1399 | */ | |
1400 | b = 0; | |
1401 | s = node->count; | |
1402 | while (s - b > 4) { | |
1403 | i = b + (s - b) / 2; | |
cb51be26 | 1404 | ++hammer_stats_btree_elements; |
af209b0f MD |
1405 | r = hammer_btree_cmp(elm, &node->elms[i].leaf.base); |
1406 | if (r <= 1) { | |
1407 | s = i; | |
1408 | } else { | |
1409 | b = i; | |
1410 | } | |
1411 | } | |
1412 | return(b); | |
1413 | } | |
1414 | ||
8cd0a023 | 1415 | |
427e5fc6 | 1416 | /************************************************************************ |
8cd0a023 | 1417 | * SPLITTING AND MERGING * |
427e5fc6 MD |
1418 | ************************************************************************ |
1419 | * | |
1420 | * These routines do all the dirty work required to split and merge nodes. | |
1421 | */ | |
1422 | ||
1423 | /* | |
8cd0a023 | 1424 | * Split an internal node into two nodes and move the separator at the split |
fe7678ee | 1425 | * point to the parent. |
427e5fc6 | 1426 | * |
8cd0a023 MD |
1427 | * (cursor->node, cursor->index) indicates the element the caller intends |
1428 | * to push into. We will adjust node and index if that element winds | |
427e5fc6 | 1429 | * up in the split node. |
8cd0a023 | 1430 | * |
47197d71 MD |
1431 | * If we are at the root of the filesystem a new root must be created with |
1432 | * two elements, one pointing to the original root and one pointing to the | |
8cd0a023 | 1433 | * newly allocated split node. |
427e5fc6 MD |
1434 | */ |
1435 | static | |
1436 | int | |
8cd0a023 | 1437 | btree_split_internal(hammer_cursor_t cursor) |
427e5fc6 | 1438 | { |
8cd0a023 MD |
1439 | hammer_node_ondisk_t ondisk; |
1440 | hammer_node_t node; | |
1441 | hammer_node_t parent; | |
1442 | hammer_node_t new_node; | |
1443 | hammer_btree_elm_t elm; | |
1444 | hammer_btree_elm_t parent_elm; | |
1775b6a0 | 1445 | struct hammer_node_lock lockroot; |
36f82b23 | 1446 | hammer_mount_t hmp = cursor->trans->hmp; |
427e5fc6 MD |
1447 | int parent_index; |
1448 | int made_root; | |
1449 | int split; | |
1450 | int error; | |
7f7c1f84 | 1451 | int i; |
8cd0a023 | 1452 | const int esize = sizeof(*elm); |
427e5fc6 | 1453 | |
1775b6a0 | 1454 | hammer_node_lock_init(&lockroot, cursor->node); |
24cf83d2 | 1455 | error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL); |
47197d71 MD |
1456 | if (error) |
1457 | goto done; | |
7bc5b8c2 MD |
1458 | if ((error = hammer_cursor_upgrade(cursor)) != 0) |
1459 | goto done; | |
cb51be26 | 1460 | ++hammer_stats_btree_splits; |
6a37e7e4 | 1461 | |
745703c7 | 1462 | /* |
fa2b9a03 MD |
1463 | * Calculate the split point. If the insertion point is at the |
1464 | * end of the leaf we adjust the split point significantly to the | |
1465 | * right to try to optimize node fill and flag it. If we hit | |
1466 | * that same leaf again our heuristic failed and we don't try | |
1467 | * to optimize node fill (it could lead to a degenerate case). | |
427e5fc6 | 1468 | */ |
8cd0a023 MD |
1469 | node = cursor->node; |
1470 | ondisk = node->ondisk; | |
fa2b9a03 MD |
1471 | KKASSERT(ondisk->count > 4); |
1472 | if (cursor->index == ondisk->count && | |
1473 | (node->flags & HAMMER_NODE_NONLINEAR) == 0) { | |
1474 | split = (ondisk->count + 1) * 3 / 4; | |
1475 | node->flags |= HAMMER_NODE_NONLINEAR; | |
1476 | } else { | |
1477 | /* | |
1478 | * We are splitting but elms[split] will be promoted to | |
1479 | * the parent, leaving the right hand node with one less | |
1480 | * element. If the insertion point will be on the | |
1481 | * left-hand side adjust the split point to give the | |
1482 | * right hand side one additional node. | |
1483 | */ | |
1484 | split = (ondisk->count + 1) / 2; | |
1485 | if (cursor->index <= split) | |
1486 | --split; | |
1487 | } | |
427e5fc6 MD |
1488 | |
1489 | /* | |
47197d71 MD |
1490 | * If we are at the root of the filesystem, create a new root node |
1491 | * with 1 element and split normally. Avoid making major | |
1492 | * modifications until we know the whole operation will work. | |
427e5fc6 | 1493 | */ |
8cd0a023 | 1494 | if (ondisk->parent == 0) { |
b4f86ea3 | 1495 | parent = hammer_alloc_btree(cursor->trans, 0, &error); |
427e5fc6 | 1496 | if (parent == NULL) |
6a37e7e4 | 1497 | goto done; |
8cd0a023 | 1498 | hammer_lock_ex(&parent->lock); |
36f82b23 | 1499 | hammer_modify_node_noundo(cursor->trans, parent); |
8cd0a023 MD |
1500 | ondisk = parent->ondisk; |
1501 | ondisk->count = 1; | |
1502 | ondisk->parent = 0; | |
a56cb012 | 1503 | ondisk->mirror_tid = node->ondisk->mirror_tid; |
8cd0a023 | 1504 | ondisk->type = HAMMER_BTREE_TYPE_INTERNAL; |
47197d71 | 1505 | ondisk->elms[0].base = hmp->root_btree_beg; |
fe7678ee | 1506 | ondisk->elms[0].base.btype = node->ondisk->type; |
8cd0a023 | 1507 | ondisk->elms[0].internal.subtree_offset = node->node_offset; |
f0b930f3 | 1508 | ondisk->elms[0].internal.mirror_tid = ondisk->mirror_tid; |
47197d71 | 1509 | ondisk->elms[1].base = hmp->root_btree_end; |
10a5d1ba | 1510 | hammer_modify_node_done(parent); |
427e5fc6 | 1511 | made_root = 1; |
8cd0a023 | 1512 | parent_index = 0; /* index of current node in parent */ |
427e5fc6 MD |
1513 | } else { |
1514 | made_root = 0; | |
8cd0a023 MD |
1515 | parent = cursor->parent; |
1516 | parent_index = cursor->parent_index; | |
427e5fc6 | 1517 | } |
427e5fc6 MD |
1518 | |
1519 | /* | |
1520 | * Split node into new_node at the split point. | |
1521 | * | |
df2ccbac | 1522 | * B O O O P N N B <-- P = node->elms[split] (index 4) |
427e5fc6 MD |
1523 | * 0 1 2 3 4 5 6 <-- subtree indices |
1524 | * | |
1525 | * x x P x x | |
745703c7 | 1526 | * s S S s |
427e5fc6 MD |
1527 | * / \ |
1528 | * B O O O B B N N B <--- inner boundary points are 'P' | |
745703c7 | 1529 | * 0 1 2 3 4 5 6 |
427e5fc6 | 1530 | */ |
b4f86ea3 | 1531 | new_node = hammer_alloc_btree(cursor->trans, 0, &error); |
427e5fc6 | 1532 | if (new_node == NULL) { |
8cd0a023 MD |
1533 | if (made_root) { |
1534 | hammer_unlock(&parent->lock); | |
36f82b23 | 1535 | hammer_delete_node(cursor->trans, parent); |
8cd0a023 MD |
1536 | hammer_rel_node(parent); |
1537 | } | |
6a37e7e4 | 1538 | goto done; |
427e5fc6 | 1539 | } |
8cd0a023 | 1540 | hammer_lock_ex(&new_node->lock); |
427e5fc6 MD |
1541 | |
1542 | /* | |
8cd0a023 | 1543 | * Create the new node. P becomes the left-hand boundary in the |
427e5fc6 MD |
1544 | * new node. Copy the right-hand boundary as well. |
1545 | * | |
1546 | * elm is the new separator. | |
1547 | */ | |
36f82b23 MD |
1548 | hammer_modify_node_noundo(cursor->trans, new_node); |
1549 | hammer_modify_node_all(cursor->trans, node); | |
8cd0a023 MD |
1550 | ondisk = node->ondisk; |
1551 | elm = &ondisk->elms[split]; | |
1552 | bcopy(elm, &new_node->ondisk->elms[0], | |
ae744f81 | 1553 | (ondisk->count - split + 1) * esize); /* +1 for boundary */ |
8cd0a023 MD |
1554 | new_node->ondisk->count = ondisk->count - split; |
1555 | new_node->ondisk->parent = parent->node_offset; | |
1556 | new_node->ondisk->type = HAMMER_BTREE_TYPE_INTERNAL; | |
a56cb012 | 1557 | new_node->ondisk->mirror_tid = ondisk->mirror_tid; |
8cd0a023 | 1558 | KKASSERT(ondisk->type == new_node->ondisk->type); |
b3bad96f | 1559 | hammer_cursor_split_node(node, new_node, split); |
427e5fc6 MD |
1560 | |
1561 | /* | |
fe7678ee MD |
1562 | * Cleanup the original node. Elm (P) becomes the new boundary, |
1563 | * its subtree_offset was moved to the new node. If we had created | |
427e5fc6 MD |
1564 | * a new root its parent pointer may have changed. |
1565 | */ | |
b6361ed8 | 1566 | elm->base.btype = HAMMER_BTREE_TYPE_NONE; |
8cd0a023 | 1567 | elm->internal.subtree_offset = 0; |
c0ade690 | 1568 | ondisk->count = split; |
427e5fc6 MD |
1569 | |
1570 | /* | |
1571 | * Insert the separator into the parent, fixup the parent's | |
1572 | * reference to the original node, and reference the new node. | |
1573 | * The separator is P. | |
1574 | * | |
3b7d788e | 1575 | * Remember that ondisk->count does not include the right-hand boundary. |
427e5fc6 | 1576 | */ |
36f82b23 | 1577 | hammer_modify_node_all(cursor->trans, parent); |
8cd0a023 | 1578 | ondisk = parent->ondisk; |
d26d0ae9 | 1579 | KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS); |
8cd0a023 | 1580 | parent_elm = &ondisk->elms[parent_index+1]; |
427e5fc6 | 1581 | bcopy(parent_elm, parent_elm + 1, |
8cd0a023 | 1582 | (ondisk->count - parent_index) * esize); |
ae744f81 TK |
1583 | |
1584 | /* | |
1585 | * Why not use hammer_make_separator() here ? | |
1586 | */ | |
8cd0a023 | 1587 | parent_elm->internal.base = elm->base; /* separator P */ |
fe7678ee | 1588 | parent_elm->internal.base.btype = new_node->ondisk->type; |
8cd0a023 | 1589 | parent_elm->internal.subtree_offset = new_node->node_offset; |
a56cb012 | 1590 | parent_elm->internal.mirror_tid = new_node->ondisk->mirror_tid; |
76376933 | 1591 | ++ondisk->count; |
10a5d1ba | 1592 | hammer_modify_node_done(parent); |
b3bad96f | 1593 | hammer_cursor_inserted_element(parent, parent_index + 1); |
427e5fc6 | 1594 | |
7f7c1f84 MD |
1595 | /* |
1596 | * The children of new_node need their parent pointer set to new_node. | |
b33e2cc0 MD |
1597 | * The children have already been locked by |
1598 | * hammer_btree_lock_children(). | |
7f7c1f84 MD |
1599 | */ |
1600 | for (i = 0; i < new_node->ondisk->count; ++i) { | |
1601 | elm = &new_node->ondisk->elms[i]; | |
90f96c37 | 1602 | error = btree_set_parent_of_child(cursor->trans, new_node, elm); |
7f7c1f84 | 1603 | if (error) { |
903fdd05 | 1604 | hpanic("btree-fixup problem"); |
7f7c1f84 MD |
1605 | } |
1606 | } | |
10a5d1ba | 1607 | hammer_modify_node_done(new_node); |
7f7c1f84 | 1608 | |
427e5fc6 | 1609 | /* |
47197d71 | 1610 | * The filesystem's root B-Tree pointer may have to be updated. |
427e5fc6 MD |
1611 | */ |
1612 | if (made_root) { | |
47197d71 MD |
1613 | hammer_volume_t volume; |
1614 | ||
1615 | volume = hammer_get_root_volume(hmp, &error); | |
1616 | KKASSERT(error == 0); | |
1617 | ||
e8599db1 MD |
1618 | hammer_modify_volume_field(cursor->trans, volume, |
1619 | vol0_btree_root); | |
47197d71 | 1620 | volume->ondisk->vol0_btree_root = parent->node_offset; |
10a5d1ba | 1621 | hammer_modify_volume_done(volume); |
8cd0a023 MD |
1622 | node->ondisk->parent = parent->node_offset; |
1623 | if (cursor->parent) { | |
1624 | hammer_unlock(&cursor->parent->lock); | |
1625 | hammer_rel_node(cursor->parent); | |
1626 | } | |
1627 | cursor->parent = parent; /* lock'd and ref'd */ | |
47197d71 | 1628 | hammer_rel_volume(volume, 0); |
427e5fc6 | 1629 | } |
10a5d1ba | 1630 | hammer_modify_node_done(node); |
427e5fc6 MD |
1631 | |
1632 | /* | |
1633 | * Ok, now adjust the cursor depending on which element the original | |
1634 | * index was pointing at. If we are >= the split point the push node | |
1635 | * is now in the new node. | |
1636 | * | |
1637 | * NOTE: If we are at the split point itself we cannot stay with the | |
1638 | * original node because the push index will point at the right-hand | |
1639 | * boundary, which is illegal. | |
8cd0a023 MD |
1640 | * |
1641 | * NOTE: The cursor's parent or parent_index must be adjusted for | |
1642 | * the case where a new parent (new root) was created, and the case | |
1643 | * where the cursor is now pointing at the split node. | |
427e5fc6 MD |
1644 | */ |
1645 | if (cursor->index >= split) { | |
8cd0a023 | 1646 | cursor->parent_index = parent_index + 1; |
427e5fc6 | 1647 | cursor->index -= split; |
8cd0a023 MD |
1648 | hammer_unlock(&cursor->node->lock); |
1649 | hammer_rel_node(cursor->node); | |
1650 | cursor->node = new_node; /* locked and ref'd */ | |
1651 | } else { | |
1652 | cursor->parent_index = parent_index; | |
1653 | hammer_unlock(&new_node->lock); | |
1654 | hammer_rel_node(new_node); | |
427e5fc6 | 1655 | } |
76376933 MD |
1656 | |
1657 | /* | |
1658 | * Fixup left and right bounds | |
1659 | */ | |
1660 | parent_elm = &parent->ondisk->elms[cursor->parent_index]; | |
fbc6e32a MD |
1661 | cursor->left_bound = &parent_elm[0].internal.base; |
1662 | cursor->right_bound = &parent_elm[1].internal.base; | |
b3deaf57 MD |
1663 | KKASSERT(hammer_btree_cmp(cursor->left_bound, |
1664 | &cursor->node->ondisk->elms[0].internal.base) <= 0); | |
1665 | KKASSERT(hammer_btree_cmp(cursor->right_bound, | |
9944ae54 | 1666 | &cursor->node->ondisk->elms[cursor->node->ondisk->count].internal.base) >= 0); |
76376933 | 1667 | |
6a37e7e4 | 1668 | done: |
24cf83d2 | 1669 | hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL); |
6a37e7e4 MD |
1670 | hammer_cursor_downgrade(cursor); |
1671 | return (error); | |
427e5fc6 MD |
1672 | } |
1673 | ||
1674 | /* | |
1675 | * Same as the above, but splits a full leaf node. | |
1676 | */ | |
1677 | static | |
1678 | int | |
8cd0a023 | 1679 | btree_split_leaf(hammer_cursor_t cursor) |
427e5fc6 | 1680 | { |
8cd0a023 MD |
1681 | hammer_node_ondisk_t ondisk; |
1682 | hammer_node_t parent; | |
1683 | hammer_node_t leaf; | |
47197d71 | 1684 | hammer_mount_t hmp; |
8cd0a023 MD |
1685 | hammer_node_t new_leaf; |
1686 | hammer_btree_elm_t elm; | |
1687 | hammer_btree_elm_t parent_elm; | |
b3deaf57 | 1688 | hammer_base_elm_t mid_boundary; |
427e5fc6 MD |
1689 | int parent_index; |
1690 | int made_root; | |
1691 | int split; | |
1692 | int error; | |
8cd0a023 | 1693 | const size_t esize = sizeof(*elm); |
427e5fc6 | 1694 | |
6a37e7e4 MD |
1695 | if ((error = hammer_cursor_upgrade(cursor)) != 0) |
1696 | return(error); | |
cb51be26 | 1697 | ++hammer_stats_btree_splits; |
6a37e7e4 | 1698 | |
36f82b23 MD |
1699 | KKASSERT(hammer_btree_cmp(cursor->left_bound, |
1700 | &cursor->node->ondisk->elms[0].leaf.base) <= 0); | |
1701 | KKASSERT(hammer_btree_cmp(cursor->right_bound, | |
1702 | &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0); | |
1703 | ||
745703c7 | 1704 | /* |
fa2b9a03 MD |
1705 | * Calculate the split point. If the insertion point is at the |
1706 | * end of the leaf we adjust the split point significantly to the | |
1707 | * right to try to optimize node fill and flag it. If we hit | |
1708 | * that same leaf again our heuristic failed and we don't try | |
1709 | * to optimize node fill (it could lead to a degenerate case). | |
427e5fc6 | 1710 | */ |
8cd0a023 MD |
1711 | leaf = cursor->node; |
1712 | ondisk = leaf->ondisk; | |
fa2b9a03 MD |
1713 | KKASSERT(ondisk->count > 4); |
1714 | if (cursor->index == ondisk->count && | |
1715 | (leaf->flags & HAMMER_NODE_NONLINEAR) == 0) { | |
1716 | split = (ondisk->count + 1) * 3 / 4; | |
1717 | leaf->flags |= HAMMER_NODE_NONLINEAR; | |
1718 | } else { | |
1719 | split = (ondisk->count + 1) / 2; | |
1720 | } | |
1721 | ||
1722 | #if 0 | |
1723 | /* | |
1724 | * If the insertion point is at the split point shift the | |
1725 | * split point left so we don't have to worry about | |
1726 | */ | |
1727 | if (cursor->index == split) | |
427e5fc6 | 1728 | --split; |
fa2b9a03 MD |
1729 | #endif |
1730 | KKASSERT(split > 0 && split < ondisk->count); | |
1731 | ||
427e5fc6 | 1732 | error = 0; |
40043e7f | 1733 | hmp = leaf->hmp; |
427e5fc6 | 1734 | |
fe7678ee | 1735 | elm = &ondisk->elms[split]; |
fe7678ee | 1736 | |
36f82b23 MD |
1737 | KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm[-1].leaf.base) <= 0); |
1738 | KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->leaf.base) <= 0); | |
1739 | KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->leaf.base) > 0); | |
1740 | KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm[1].leaf.base) > 0); | |
1741 | ||
427e5fc6 MD |
1742 | /* |
1743 | * If we are at the root of the tree, create a new root node with | |
1744 | * 1 element and split normally. Avoid making major modifications | |
1745 | * until we know the whole operation will work. | |
1746 | */ | |
8cd0a023 | 1747 | if (ondisk->parent == 0) { |
b4f86ea3 | 1748 | parent = hammer_alloc_btree(cursor->trans, 0, &error); |
427e5fc6 | 1749 | if (parent == NULL) |
6a37e7e4 | 1750 | goto done; |
8cd0a023 | 1751 | hammer_lock_ex(&parent->lock); |
36f82b23 | 1752 | hammer_modify_node_noundo(cursor->trans, parent); |
8cd0a023 MD |
1753 | ondisk = parent->ondisk; |
1754 | ondisk->count = 1; | |
1755 | ondisk->parent = 0; | |
a56cb012 | 1756 | ondisk->mirror_tid = leaf->ondisk->mirror_tid; |
8cd0a023 | 1757 | ondisk->type = HAMMER_BTREE_TYPE_INTERNAL; |
47197d71 | 1758 | ondisk->elms[0].base = hmp->root_btree_beg; |
fe7678ee | 1759 | ondisk->elms[0].base.btype = leaf->ondisk->type; |
8cd0a023 | 1760 | ondisk->elms[0].internal.subtree_offset = leaf->node_offset; |
f0b930f3 | 1761 | ondisk->elms[0].internal.mirror_tid = ondisk->mirror_tid; |
47197d71 | 1762 | ondisk->elms[1].base = hmp->root_btree_end; |
10a5d1ba | 1763 | hammer_modify_node_done(parent); |
427e5fc6 | 1764 | made_root = 1; |
8cd0a023 | 1765 | parent_index = 0; /* insertion point in parent */ |
427e5fc6 MD |
1766 | } else { |
1767 | made_root = 0; | |
8cd0a023 MD |
1768 | parent = cursor->parent; |
1769 | parent_index = cursor->parent_index; | |
427e5fc6 | 1770 | } |
427e5fc6 MD |
1771 | |
1772 | /* | |
1773 | * Split leaf into new_leaf at the split point. Select a separator | |
1774 | * value in-between the two leafs but with a bent towards the right | |
1775 | * leaf since comparisons use an 'elm >= separator' inequality. | |
1776 | * | |
1777 | * L L L L L L L L | |
1778 | * | |
1779 | * x x P x x | |
745703c7 | 1780 | * s S S s |
427e5fc6 MD |
1781 | * / \ |
1782 | * L L L L L L L L | |
1783 | */ | |
b4f86ea3 | 1784 | new_leaf = hammer_alloc_btree(cursor->trans, 0, &error); |
427e5fc6 | 1785 | if (new_leaf == NULL) { |
8cd0a023 MD |
1786 | if (made_root) { |
1787 | hammer_unlock(&parent->lock); | |
36f82b23 | 1788 | hammer_delete_node(cursor->trans, parent); |
8cd0a023 MD |
1789 | hammer_rel_node(parent); |
1790 | } | |
6a37e7e4 | 1791 | goto done; |
427e5fc6 | 1792 | } |
8cd0a023 | 1793 | hammer_lock_ex(&new_leaf->lock); |
427e5fc6 MD |
1794 | |
1795 | /* | |
745703c7 | 1796 | * Create the new node and copy the leaf elements from the split |
36f82b23 | 1797 | * point on to the new node. |
427e5fc6 | 1798 | */ |
36f82b23 MD |
1799 | hammer_modify_node_all(cursor->trans, leaf); |
1800 | hammer_modify_node_noundo(cursor->trans, new_leaf); | |
8cd0a023 MD |
1801 | ondisk = leaf->ondisk; |
1802 | elm = &ondisk->elms[split]; | |
1803 | bcopy(elm, &new_leaf->ondisk->elms[0], (ondisk->count - split) * esize); | |
1804 | new_leaf->ondisk->count = ondisk->count - split; | |
1805 | new_leaf->ondisk->parent = parent->node_offset; | |
1806 | new_leaf->ondisk->type = HAMMER_BTREE_TYPE_LEAF; | |
a56cb012 | 1807 | new_leaf->ondisk->mirror_tid = ondisk->mirror_tid; |
8cd0a023 | 1808 | KKASSERT(ondisk->type == new_leaf->ondisk->type); |
10a5d1ba | 1809 | hammer_modify_node_done(new_leaf); |
b3bad96f | 1810 | hammer_cursor_split_node(leaf, new_leaf, split); |
427e5fc6 MD |
1811 | |
1812 | /* | |
8cd0a023 MD |
1813 | * Cleanup the original node. Because this is a leaf node and |
1814 | * leaf nodes do not have a right-hand boundary, there | |
c0ade690 MD |
1815 | * aren't any special edge cases to clean up. We just fixup the |
1816 | * count. | |
427e5fc6 | 1817 | */ |
c0ade690 | 1818 | ondisk->count = split; |
427e5fc6 MD |
1819 | |
1820 | /* | |
1821 | * Insert the separator into the parent, fixup the parent's | |
1822 | * reference to the original node, and reference the new node. | |
1823 | * The separator is P. | |
1824 | * | |
3b7d788e | 1825 | * Remember that ondisk->count does not include the right-hand boundary. |
427e5fc6 MD |
1826 | * We are copying parent_index+1 to parent_index+2, not +0 to +1. |
1827 | */ | |
36f82b23 | 1828 | hammer_modify_node_all(cursor->trans, parent); |
8cd0a023 | 1829 | ondisk = parent->ondisk; |
36f82b23 | 1830 | KKASSERT(split != 0); |
d26d0ae9 | 1831 | KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS); |
8cd0a023 | 1832 | parent_elm = &ondisk->elms[parent_index+1]; |
d26d0ae9 MD |
1833 | bcopy(parent_elm, parent_elm + 1, |
1834 | (ondisk->count - parent_index) * esize); | |
eaeff70d | 1835 | |
ae744f81 TK |
1836 | /* |
1837 | * elm[-1] is the right-most elm in the original node. | |
1838 | * elm[0] equals the left-most elm at index=0 in the new node. | |
1839 | * parent_elm[-1] and parent_elm point to original and new node. | |
1840 | * Update the parent_elm base to meet >elm[-1] and <=elm[0]. | |
1841 | */ | |
47197d71 | 1842 | hammer_make_separator(&elm[-1].base, &elm[0].base, &parent_elm->base); |
fe7678ee | 1843 | parent_elm->internal.base.btype = new_leaf->ondisk->type; |
8cd0a023 | 1844 | parent_elm->internal.subtree_offset = new_leaf->node_offset; |
a56cb012 | 1845 | parent_elm->internal.mirror_tid = new_leaf->ondisk->mirror_tid; |
b3deaf57 | 1846 | mid_boundary = &parent_elm->base; |
76376933 | 1847 | ++ondisk->count; |
10a5d1ba | 1848 | hammer_modify_node_done(parent); |
b3bad96f | 1849 | hammer_cursor_inserted_element(parent, parent_index + 1); |
427e5fc6 | 1850 | |
fe7678ee | 1851 | /* |
47197d71 | 1852 | * The filesystem's root B-Tree pointer may have to be updated. |
427e5fc6 MD |
1853 | */ |
1854 | if (made_root) { | |
47197d71 MD |
1855 | hammer_volume_t volume; |
1856 | ||
1857 | volume = hammer_get_root_volume(hmp, &error); | |
1858 | KKASSERT(error == 0); | |
1859 | ||
e8599db1 MD |
1860 | hammer_modify_volume_field(cursor->trans, volume, |
1861 | vol0_btree_root); | |
47197d71 | 1862 | volume->ondisk->vol0_btree_root = parent->node_offset; |
10a5d1ba | 1863 | hammer_modify_volume_done(volume); |
8cd0a023 MD |
1864 | leaf->ondisk->parent = parent->node_offset; |
1865 | if (cursor->parent) { | |
1866 | hammer_unlock(&cursor->parent->lock); | |
1867 | hammer_rel_node(cursor->parent); | |
1868 | } | |
1869 | cursor->parent = parent; /* lock'd and ref'd */ | |
47197d71 | 1870 | hammer_rel_volume(volume, 0); |
427e5fc6 | 1871 | } |
10a5d1ba | 1872 | hammer_modify_node_done(leaf); |
8cd0a023 | 1873 | |
427e5fc6 MD |
1874 | /* |
1875 | * Ok, now adjust the cursor depending on which element the original | |
1876 | * index was pointing at. If we are >= the split point the push node | |
1877 | * is now in the new node. | |
1878 | * | |
b3deaf57 MD |
1879 | * NOTE: If we are at the split point itself we need to select the |
1880 | * old or new node based on where key_beg's insertion point will be. | |
1881 | * If we pick the wrong side the inserted element will wind up in | |
1882 | * the wrong leaf node and outside that node's bounds. | |
427e5fc6 | 1883 | */ |
b3deaf57 MD |
1884 | if (cursor->index > split || |
1885 | (cursor->index == split && | |
1886 | hammer_btree_cmp(&cursor->key_beg, mid_boundary) >= 0)) { | |
8cd0a023 | 1887 | cursor->parent_index = parent_index + 1; |
427e5fc6 | 1888 | cursor->index -= split; |
8cd0a023 MD |
1889 | hammer_unlock(&cursor->node->lock); |
1890 | hammer_rel_node(cursor->node); | |
1891 | cursor->node = new_leaf; | |
1892 | } else { | |
1893 | cursor->parent_index = parent_index; | |
1894 | hammer_unlock(&new_leaf->lock); | |
1895 | hammer_rel_node(new_leaf); | |
427e5fc6 | 1896 | } |
76376933 MD |
1897 | |
1898 | /* | |
1899 | * Fixup left and right bounds | |
1900 | */ | |
1901 | parent_elm = &parent->ondisk->elms[cursor->parent_index]; | |
fbc6e32a MD |
1902 | cursor->left_bound = &parent_elm[0].internal.base; |
1903 | cursor->right_bound = &parent_elm[1].internal.base; | |
eaeff70d MD |
1904 | |
1905 | /* | |
47197d71 | 1906 | * Assert that the bounds are correct. |
eaeff70d | 1907 | */ |
b3deaf57 MD |
1908 | KKASSERT(hammer_btree_cmp(cursor->left_bound, |
1909 | &cursor->node->ondisk->elms[0].leaf.base) <= 0); | |
1910 | KKASSERT(hammer_btree_cmp(cursor->right_bound, | |
47197d71 | 1911 | &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0); |
36f82b23 MD |
1912 | KKASSERT(hammer_btree_cmp(cursor->left_bound, &cursor->key_beg) <= 0); |
1913 | KKASSERT(hammer_btree_cmp(cursor->right_bound, &cursor->key_beg) > 0); | |
76376933 | 1914 | |
6a37e7e4 MD |
1915 | done: |
1916 | hammer_cursor_downgrade(cursor); | |
1917 | return (error); | |
427e5fc6 MD |
1918 | } |
1919 | ||
adf01747 MD |
1920 | #if 0 |
1921 | ||
32c90105 MD |
1922 | /* |
1923 | * Recursively correct the right-hand boundary's create_tid to (tid) as | |
1924 | * long as the rest of the key matches. We have to recurse upward in | |
1925 | * the tree as well as down the left side of each parent's right node. | |
1926 | * | |
1927 | * Return EDEADLK if we were only partially successful, forcing the caller | |
1928 | * to try again. The original cursor is not modified. This routine can | |
1929 | * also fail with EDEADLK if it is forced to throw away a portion of its | |
1930 | * record history. | |
1931 | * | |
1932 | * The caller must pass a downgraded cursor to us (otherwise we can't dup it). | |
1933 | */ | |
1934 | struct hammer_rhb { | |
1935 | TAILQ_ENTRY(hammer_rhb) entry; | |
1936 | hammer_node_t node; | |
1937 | int index; | |
1938 | }; | |
1939 | ||
1940 | TAILQ_HEAD(hammer_rhb_list, hammer_rhb); | |
1941 | ||
1942 | int | |
1943 | hammer_btree_correct_rhb(hammer_cursor_t cursor, hammer_tid_t tid) | |
1944 | { | |
ba2be8e9 | 1945 | hammer_mount_t hmp; |
32c90105 MD |
1946 | struct hammer_rhb_list rhb_list; |
1947 | hammer_base_elm_t elm; | |
1948 | hammer_node_t orig_node; | |
1949 | struct hammer_rhb *rhb; | |
1950 | int orig_index; | |
1951 | int error; | |
1952 | ||
1953 | TAILQ_INIT(&rhb_list); | |
bac808fe | 1954 | hmp = cursor->trans->hmp; |
32c90105 MD |
1955 | |
1956 | /* | |
1957 | * Save our position so we can restore it on return. This also | |
1958 | * gives us a stable 'elm'. | |
1959 | */ | |
1960 | orig_node = cursor->node; | |
1961 | hammer_ref_node(orig_node); | |
1962 | hammer_lock_sh(&orig_node->lock); | |
1963 | orig_index = cursor->index; | |
1964 | elm = &orig_node->ondisk->elms[orig_index].base; | |
1965 | ||
1966 | /* | |
1967 | * Now build a list of parents going up, allocating a rhb | |
1968 | * structure for each one. | |
1969 | */ | |
1970 | while (cursor->parent) { | |
1971 | /* | |
1972 | * Stop if we no longer have any right-bounds to fix up | |
1973 | */ | |
1974 | if (elm->obj_id != cursor->right_bound->obj_id || | |
1975 | elm->rec_type != cursor->right_bound->rec_type || | |
1976 | elm->key != cursor->right_bound->key) { | |
1977 | break; | |
1978 | } | |
1979 | ||
1980 | /* | |
1981 | * Stop if the right-hand bound's create_tid does not | |
47197d71 | 1982 | * need to be corrected. |
32c90105 MD |
1983 | */ |
1984 | if (cursor->right_bound->create_tid >= tid) | |
1985 | break; | |
1986 | ||
bac808fe | 1987 | rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO); |
32c90105 MD |
1988 | rhb->node = cursor->parent; |
1989 | rhb->index = cursor->parent_index; | |
1990 | hammer_ref_node(rhb->node); | |
1991 | hammer_lock_sh(&rhb->node->lock); | |
1992 | TAILQ_INSERT_HEAD(&rhb_list, rhb, entry); | |
1993 | ||
1994 | hammer_cursor_up(cursor); | |
1995 | } | |
1996 | ||
1997 | /* | |
1998 | * now safely adjust the right hand bound for each rhb. This may | |
1999 | * also require taking the right side of the tree and iterating down | |
2000 | * ITS left side. | |
2001 | */ | |
2002 | error = 0; | |
2003 | while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) { | |
2004 | error = hammer_cursor_seek(cursor, rhb->node, rhb->index); | |
32c90105 MD |
2005 | if (error) |
2006 | break; | |
2007 | TAILQ_REMOVE(&rhb_list, rhb, entry); | |
2008 | hammer_unlock(&rhb->node->lock); | |
2009 | hammer_rel_node(rhb->node); | |
bac808fe | 2010 | kfree(rhb, hmp->m_misc); |
32c90105 MD |
2011 | |
2012 | switch (cursor->node->ondisk->type) { | |
2013 | case HAMMER_BTREE_TYPE_INTERNAL: | |
2014 | /* | |
2015 | * Right-boundary for parent at internal node | |
2016 | * is one element to the right of the element whos | |
2017 | * right boundary needs adjusting. We must then | |
2018 | * traverse down the left side correcting any left | |
2019 | * bounds (which may now be too far to the left). | |
2020 | */ | |
2021 | ++cursor->index; | |
2022 | error = hammer_btree_correct_lhb(cursor, tid); | |
2023 | break; | |
32c90105 | 2024 | default: |
903fdd05 | 2025 | hpanic("Bad node type"); |
32c90105 MD |
2026 | error = EINVAL; |
2027 | break; | |
2028 | } | |
2029 | } | |
2030 | ||
2031 | /* | |
2032 | * Cleanup | |
2033 | */ | |
2034 | while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) { | |
2035 | TAILQ_REMOVE(&rhb_list, rhb, entry); | |
2036 | hammer_unlock(&rhb->node->lock); | |
2037 | hammer_rel_node(rhb->node); | |
bac808fe | 2038 | kfree(rhb, hmp->m_misc); |
32c90105 MD |
2039 | } |
2040 | error = hammer_cursor_seek(cursor, orig_node, orig_index); | |
2041 | hammer_unlock(&orig_node->lock); | |
2042 | hammer_rel_node(orig_node); | |
2043 | return (error); | |
2044 | } | |
2045 | ||
2046 | /* | |
2047 | * Similar to rhb (in fact, rhb calls lhb), but corrects the left hand | |
2048 | * bound going downward starting at the current cursor position. | |
2049 | * | |
2050 | * This function does not restore the cursor after use. | |
2051 | */ | |
2052 | int | |
2053 | hammer_btree_correct_lhb(hammer_cursor_t cursor, hammer_tid_t tid) | |
2054 | { | |
2055 | struct hammer_rhb_list rhb_list; | |
2056 | hammer_base_elm_t elm; | |
2057 | hammer_base_elm_t cmp; | |
2058 | struct hammer_rhb *rhb; | |
ba2be8e9 | 2059 | hammer_mount_t hmp; |
32c90105 MD |
2060 | int error; |
2061 | ||
2062 | TAILQ_INIT(&rhb_list); | |
bac808fe | 2063 | hmp = cursor->trans->hmp; |
32c90105 MD |
2064 | |
2065 | cmp = &cursor->node->ondisk->elms[cursor->index].base; | |
2066 | ||
2067 | /* | |
2068 | * Record the node and traverse down the left-hand side for all | |
2069 | * matching records needing a boundary correction. | |
2070 | */ | |
2071 | error = 0; | |
2072 | for (;;) { | |
bac808fe | 2073 | rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO); |
32c90105 MD |
2074 | rhb->node = cursor->node; |
2075 | rhb->index = cursor->index; | |
2076 | hammer_ref_node(rhb->node); | |
2077 | hammer_lock_sh(&rhb->node->lock); | |
2078 | TAILQ_INSERT_HEAD(&rhb_list, rhb, entry); | |
2079 | ||
2080 | if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) { | |
2081 | /* | |
2082 | * Nothing to traverse down if we are at the right | |
2083 | * boundary of an internal node. | |
2084 | */ | |
2085 | if (cursor->index == cursor->node->ondisk->count) | |
2086 | break; | |
2087 | } else { | |
2088 | elm = &cursor->node->ondisk->elms[cursor->index].base; | |
2089 | if (elm->btype == HAMMER_BTREE_TYPE_RECORD) | |
2090 | break; | |
5134aacd | 2091 | hpanic("Illegal leaf record type %02x", elm->btype); |
32c90105 MD |
2092 | } |
2093 | error = hammer_cursor_down(cursor); | |
2094 | if (error) | |
2095 | break; | |
2096 | ||
2097 | elm = &cursor->node->ondisk->elms[cursor->index].base; | |
2098 | if (elm->obj_id != cmp->obj_id || | |
2099 | elm->rec_type != cmp->rec_type || | |
2100 | elm->key != cmp->key) { | |
2101 | break; | |
2102 | } | |
2103 | if (elm->create_tid >= tid) | |
2104 | break; | |
2105 | ||
2106 | } | |
2107 | ||
2108 | /* | |
2109 | * Now we can safely adjust the left-hand boundary from the bottom-up. | |
2110 | * The last element we remove from the list is the caller's right hand | |
2111 | * boundary, which must also be adjusted. | |
2112 | */ | |
2113 | while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) { | |
2114 | error = hammer_cursor_seek(cursor, rhb->node, rhb->index); | |
2115 | if (error) | |
2116 | break; | |
2117 | TAILQ_REMOVE(&rhb_list, rhb, entry); | |
2118 | hammer_unlock(&rhb->node->lock); | |
2119 | hammer_rel_node(rhb->node); | |
bac808fe | 2120 | kfree(rhb, hmp->m_misc); |
32c90105 MD |
2121 | |
2122 | elm = &cursor->node->ondisk->elms[cursor->index].base; | |
2123 | if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) { | |
36f82b23 | 2124 | hammer_modify_node(cursor->trans, cursor->node, |
19619882 MD |
2125 | &elm->create_tid, |
2126 | sizeof(elm->create_tid)); | |
32c90105 | 2127 | elm->create_tid = tid; |
10a5d1ba | 2128 | hammer_modify_node_done(cursor->node); |
32c90105 | 2129 | } else { |
903fdd05 | 2130 | hpanic("Bad element type"); |
32c90105 MD |
2131 | } |
2132 | } | |
2133 | ||
2134 | /* | |
2135 | * Cleanup | |
2136 | */ | |
2137 | while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) { | |
2138 | TAILQ_REMOVE(&rhb_list, rhb, entry); | |
2139 | hammer_unlock(&rhb->node->lock); | |
2140 | hammer_rel_node(rhb->node); | |
bac808fe | 2141 | kfree(rhb, hmp->m_misc); |
32c90105 MD |
2142 | } |
2143 | return (error); | |
2144 | } | |
2145 | ||
adf01747 MD |
2146 | #endif |
2147 | ||
427e5fc6 | 2148 | /* |
f36a9737 MD |
2149 | * Attempt to remove the locked, empty or want-to-be-empty B-Tree node at |
2150 | * (cursor->node). Returns 0 on success, EDEADLK if we could not complete | |
2151 | * the operation due to a deadlock, or some other error. | |
8cd0a023 | 2152 | * |
5c8d05e2 MD |
2153 | * This routine is initially called with an empty leaf and may be |
2154 | * recursively called with single-element internal nodes. | |
b3deaf57 | 2155 | * |
c82af904 MD |
2156 | * It should also be noted that when removing empty leaves we must be sure |
2157 | * to test and update mirror_tid because another thread may have deadlocked | |
5fa5c92f | 2158 | * against us (or someone) trying to propagate it up and cannot retry once |
c82af904 MD |
2159 | * the node has been deleted. |
2160 | * | |
f36a9737 MD |
2161 | * On return the cursor may end up pointing to an internal node, suitable |
2162 | * for further iteration but not for an immediate insertion or deletion. | |
8cd0a023 | 2163 | */ |
f36a9737 | 2164 | static int |
03b6feea | 2165 | btree_remove(hammer_cursor_t cursor, int *ndelete) |
8cd0a023 MD |
2166 | { |
2167 | hammer_node_ondisk_t ondisk; | |
195c19a1 | 2168 | hammer_btree_elm_t elm; |
195c19a1 | 2169 | hammer_node_t node; |
8cd0a023 | 2170 | hammer_node_t parent; |
fe7678ee | 2171 | const int esize = sizeof(*elm); |
8cd0a023 | 2172 | int error; |
8cd0a023 | 2173 | |
fe7678ee MD |
2174 | node = cursor->node; |
2175 | ||
47197d71 MD |
2176 | /* |
2177 | * When deleting the root of the filesystem convert it to | |
2178 | * an empty leaf node. Internal nodes cannot be empty. | |
2179 | */ | |
c82af904 MD |
2180 | ondisk = node->ondisk; |
2181 | if (ondisk->parent == 0) { | |
f36a9737 | 2182 | KKASSERT(cursor->parent == NULL); |
36f82b23 | 2183 | hammer_modify_node_all(cursor->trans, node); |
c82af904 | 2184 | KKASSERT(ondisk == node->ondisk); |
195c19a1 MD |
2185 | ondisk->type = HAMMER_BTREE_TYPE_LEAF; |
2186 | ondisk->count = 0; | |
10a5d1ba | 2187 | hammer_modify_node_done(node); |
b3deaf57 | 2188 | cursor->index = 0; |
47197d71 | 2189 | return(0); |
8cd0a023 MD |
2190 | } |
2191 | ||
c82af904 MD |
2192 | parent = cursor->parent; |
2193 | ||
8cd0a023 | 2194 | /* |
f36a9737 | 2195 | * Attempt to remove the parent's reference to the child. If the |
745703c7 | 2196 | * parent would become empty we have to recurse. If we fail we |
f36a9737 | 2197 | * leave the parent pointing to an empty leaf node. |
5c8d05e2 MD |
2198 | * |
2199 | * We have to recurse successfully before we can delete the internal | |
2200 | * node as it is illegal to have empty internal nodes. Even though | |
2201 | * the operation may be aborted we must still fixup any unlocked | |
2202 | * cursors as if we had deleted the element prior to recursing | |
2203 | * (by calling hammer_cursor_deleted_element()) so those cursors | |
2204 | * are properly forced up the chain by the recursion. | |
8cd0a023 | 2205 | */ |
f36a9737 MD |
2206 | if (parent->ondisk->count == 1) { |
2207 | /* | |
2208 | * This special cursor_up_locked() call leaves the original | |
2209 | * node exclusively locked and referenced, leaves the | |
2210 | * original parent locked (as the new node), and locks the | |
2211 | * new parent. It can return EDEADLK. | |
f3a4893b MD |
2212 | * |
2213 | * We cannot call hammer_cursor_removed_node() until we are | |
2214 | * actually able to remove the node. If we did then tracked | |
2215 | * cursors in the middle of iterations could be repointed | |
2216 | * to a parent node. If this occurs they could end up | |
2217 | * scanning newly inserted records into the node (that could | |
2218 | * not be deleted) when they push down again. | |
2219 | * | |
2220 | * Due to the way the recursion works the final parent is left | |
2221 | * in cursor->parent after the recursion returns. Each | |
2222 | * layer on the way back up is thus able to call | |
2223 | * hammer_cursor_removed_node() and 'jump' the node up to | |
2224 | * the (same) final parent. | |
2225 | * | |
2226 | * NOTE! The local variable 'parent' is invalid after we | |
2227 | * call hammer_cursor_up_locked(). | |
f36a9737 MD |
2228 | */ |
2229 | error = hammer_cursor_up_locked(cursor); | |
f3a4893b MD |
2230 | parent = NULL; |
2231 | ||
f36a9737 | 2232 | if (error == 0) { |
5c8d05e2 | 2233 | hammer_cursor_deleted_element(cursor->node, 0); |
03b6feea | 2234 | error = btree_remove(cursor, ndelete); |
f36a9737 | 2235 | if (error == 0) { |
901ba05c | 2236 | KKASSERT(node != cursor->node); |
f3a4893b | 2237 | hammer_cursor_removed_node( |
653fa4cd | 2238 | node, cursor->node, cursor->index); |
f36a9737 MD |
2239 | hammer_modify_node_all(cursor->trans, node); |
2240 | ondisk = node->ondisk; | |
2241 | ondisk->type = HAMMER_BTREE_TYPE_DELETED; | |
2242 | ondisk->count = 0; | |
2243 | hammer_modify_node_done(node); | |
250aec18 | 2244 | hammer_flush_node(node, 0); |
f36a9737 | 2245 | hammer_delete_node(cursor->trans, node); |
03b6feea TK |
2246 | if (ndelete) |
2247 | (*ndelete)++; | |
f36a9737 | 2248 | } else { |
3214ade6 MD |
2249 | /* |
2250 | * Defer parent removal because we could not | |
2251 | * get the lock, just let the leaf remain | |
2252 | * empty. | |
2253 | */ | |
8260ce22 TK |
2254 | /* |
2255 | * hammer show doesn't consider this as an error. | |
2256 | */ | |
f36a9737 MD |
2257 | } |
2258 | hammer_unlock(&node->lock); | |
2259 | hammer_rel_node(node); | |
2260 | } else { | |
3214ade6 MD |
2261 | /* |
2262 | * Defer parent removal because we could not | |
2263 | * get the lock, just let the leaf remain | |
2264 | * empty. | |
2265 | */ | |
8260ce22 TK |
2266 | /* |
2267 | * hammer show doesn't consider this as an error. | |
2268 | */ | |
f36a9737 MD |
2269 | } |
2270 | } else { | |
2271 | KKASSERT(parent->ondisk->count > 1); | |
6a37e7e4 | 2272 | |
f36a9737 MD |
2273 | hammer_modify_node_all(cursor->trans, parent); |
2274 | ondisk = parent->ondisk; | |
2275 | KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_INTERNAL); | |
c82af904 | 2276 | |
f36a9737 MD |
2277 | elm = &ondisk->elms[cursor->parent_index]; |
2278 | KKASSERT(elm->internal.subtree_offset == node->node_offset); | |
2279 | KKASSERT(ondisk->count > 0); | |
4c038e17 MD |
2280 | |
2281 | /* | |
2282 | * We must retain the highest mirror_tid. The deleted | |
2283 | * range is now encompassed by the element to the left. | |
2284 | * If we are already at the left edge the new left edge | |
2285 | * inherits mirror_tid. | |
2286 | * | |
2287 | * Note that bounds of the parent to our parent may create | |
2288 | * a gap to the left of our left-most node or to the right | |
2289 | * of our right-most node. The gap is silently included | |
2290 | * in the mirror_tid's area of effect from the point of view | |
2291 | * of the scan. | |
2292 | */ | |
2293 | if (cursor->parent_index) { | |
2294 | if (elm[-1].internal.mirror_tid < | |
2295 | elm[0].internal.mirror_tid) { | |
2296 | elm[-1].internal.mirror_tid = | |
2297 | elm[0].internal.mirror_tid; | |
2298 | } | |
2299 | } else { | |
2300 | if (elm[1].internal.mirror_tid < | |
2301 | elm[0].internal.mirror_tid) { | |
2302 | elm[1].internal.mirror_tid = | |
2303 | elm[0].internal.mirror_tid; | |
2304 | } | |
2305 | } | |
2306 | ||
2307 | /* | |
f3a4893b MD |
2308 | * Delete the subtree reference in the parent. Include |
2309 | * boundary element at end. | |
4c038e17 | 2310 | */ |
f36a9737 MD |
2311 | bcopy(&elm[1], &elm[0], |
2312 | (ondisk->count - cursor->parent_index) * esize); | |
2313 | --ondisk->count; | |
10a5d1ba | 2314 | hammer_modify_node_done(parent); |
f3a4893b | 2315 | hammer_cursor_removed_node(node, parent, cursor->parent_index); |
6c1f89f4 | 2316 | hammer_cursor_deleted_element(parent, cursor->parent_index); |
250aec18 | 2317 | hammer_flush_node(node, 0); |
f36a9737 | 2318 | hammer_delete_node(cursor->trans, node); |
6a37e7e4 | 2319 | |
f36a9737 MD |
2320 | /* |
2321 | * cursor->node is invalid, cursor up to make the cursor | |
ec9b6294 MD |
2322 | * valid again. We have to flag the condition in case |
2323 | * another thread wiggles an insertion in during an | |
2324 | * iteration. | |
f36a9737 | 2325 | */ |
ec9b6294 | 2326 | cursor->flags |= HAMMER_CURSOR_ITERATE_CHECK; |
f36a9737 | 2327 | error = hammer_cursor_up(cursor); |
03b6feea TK |
2328 | if (ndelete) |
2329 | (*ndelete)++; | |
6a37e7e4 | 2330 | } |
f36a9737 | 2331 | return (error); |
6a37e7e4 MD |
2332 | } |
2333 | ||
602c6cb8 | 2334 | /* |
b077a45c | 2335 | * Propagate mirror_tid up the B-Tree starting at the current cursor. |
c9ce54d6 MD |
2336 | * |
2337 | * WARNING! Because we push and pop the passed cursor, it may be | |
2338 | * modified by other B-Tree operations while it is unlocked | |
2339 | * and things like the node & leaf pointers, and indexes might | |
2340 | * change. | |
602c6cb8 MD |
2341 | */ |
2342 | void | |
4c038e17 | 2343 | hammer_btree_do_propagation(hammer_cursor_t cursor, |
602c6cb8 MD |
2344 | hammer_btree_leaf_elm_t leaf) |
2345 | { | |
adf01747 MD |
2346 | hammer_cursor_t ncursor; |
2347 | hammer_tid_t mirror_tid; | |
f31f6d84 | 2348 | int error __debugvar; |
602c6cb8 MD |
2349 | |
2350 | /* | |
732a1697 MD |
2351 | * We do not propagate a mirror_tid if the filesystem was mounted |
2352 | * in no-mirror mode. | |
602c6cb8 | 2353 | */ |
732a1697 | 2354 | if (cursor->trans->hmp->master_id < 0) |
602c6cb8 | 2355 | return; |
602c6cb8 | 2356 | |
adf01747 MD |
2357 | /* |
2358 | * This is a bit of a hack because we cannot deadlock or return | |
2359 | * EDEADLK here. The related operation has already completed and | |
2360 | * we must propagate the mirror_tid now regardless. | |
2361 | * | |
2362 | * Generate a new cursor which inherits the original's locks and | |
2363 | * unlock the original. Use the new cursor to propagate the | |
2364 | * mirror_tid. Then clean up the new cursor and reacquire locks | |
2365 | * on the original. | |
2366 | * | |
2367 | * hammer_dup_cursor() cannot dup locks. The dup inherits the | |
2368 | * original's locks and the original is tracked and must be | |
2369 | * re-locked. | |
2370 | */ | |
2371 | mirror_tid = cursor->node->ondisk->mirror_tid; | |
a56cb012 | 2372 | KKASSERT(mirror_tid != 0); |
3f43fb33 | 2373 | ncursor = hammer_push_cursor(cursor); |
adf01747 MD |
2374 | error = hammer_btree_mirror_propagate(ncursor, mirror_tid); |
2375 | KKASSERT(error == 0); | |
3f43fb33 | 2376 | hammer_pop_cursor(cursor, ncursor); |
c9ce54d6 | 2377 | /* WARNING: cursor's leaf pointer may change after pop */ |
602c6cb8 MD |
2378 | } |
2379 | ||
2380 | ||
c82af904 MD |
2381 | /* |
2382 | * Propagate a mirror TID update upwards through the B-Tree to the root. | |
2383 | * | |
2384 | * A locked internal node must be passed in. The node will remain locked | |
2385 | * on return. | |
2386 | * | |
2387 | * This function syncs mirror_tid at the specified internal node's element, | |
2388 | * adjusts the node's aggregation mirror_tid, and then recurses upwards. | |
2389 | */ | |
602c6cb8 | 2390 | static int |
adf01747 | 2391 | hammer_btree_mirror_propagate(hammer_cursor_t cursor, hammer_tid_t mirror_tid) |
c82af904 MD |
2392 | { |
2393 | hammer_btree_internal_elm_t elm; | |
adf01747 | 2394 | hammer_node_t node; |
c82af904 MD |
2395 | int error; |
2396 | ||
adf01747 MD |
2397 | for (;;) { |
2398 | error = hammer_cursor_up(cursor); | |
2399 | if (error == 0) | |
2400 | error = hammer_cursor_upgrade(cursor); | |
6dc17446 MD |
2401 | |
2402 | /* | |
2403 | * We can ignore HAMMER_CURSOR_ITERATE_CHECK, the | |
2404 | * cursor will still be properly positioned for | |
2405 | * mirror propagation, just not for iterations. | |
2406 | */ | |
adf01747 MD |
2407 | while (error == EDEADLK) { |
2408 | hammer_recover_cursor(cursor); | |
2409 | error = hammer_cursor_upgrade(cursor); | |
2410 | } | |
2411 | if (error) | |
2412 | break; | |
95885f20 MD |
2413 | |
2414 | /* | |
2415 | * If the cursor deadlocked it could end up at a leaf | |
2416 | * after we lost the lock. | |
2417 | */ | |
adf01747 | 2418 | node = cursor->node; |
95885f20 MD |
2419 | if (node->ondisk->type != HAMMER_BTREE_TYPE_INTERNAL) |
2420 | continue; | |
c82af904 | 2421 | |
adf01747 MD |
2422 | /* |
2423 | * Adjust the node's element | |
2424 | */ | |
2425 | elm = &node->ondisk->elms[cursor->index].internal; | |
2426 | if (elm->mirror_tid >= mirror_tid) | |
2427 | break; | |
2428 | hammer_modify_node(cursor->trans, node, &elm->mirror_tid, | |
2429 | sizeof(elm->mirror_tid)); | |
2430 | elm->mirror_tid = mirror_tid; | |
2431 | hammer_modify_node_done(node); | |
02325004 | 2432 | if (hammer_debug_general & 0x0002) { |
35a5249b TK |
2433 | hdkprintf("propagate %016jx @%016jx:%d\n", |
2434 | (intmax_t)mirror_tid, | |
2435 | (intmax_t)node->node_offset, | |
973c11b9 | 2436 | cursor->index); |
02325004 MD |
2437 | } |
2438 | ||
c82af904 | 2439 | |
adf01747 MD |
2440 | /* |
2441 | * Adjust the node's mirror_tid aggregator | |
2442 | */ | |
2443 | if (node->ondisk->mirror_tid >= mirror_tid) | |
2444 | return(0); | |
2445 | hammer_modify_node_field(cursor->trans, node, mirror_tid); | |
2446 | node->ondisk->mirror_tid = mirror_tid; | |
2447 | hammer_modify_node_done(node); | |
02325004 | 2448 | if (hammer_debug_general & 0x0002) { |
35a5249b TK |
2449 | hdkprintf("propagate %016jx @%016jx\n", |
2450 | (intmax_t)mirror_tid, | |
2451 | (intmax_t)node->node_offset); | |
02325004 | 2452 | } |
c82af904 | 2453 | } |
adf01747 MD |
2454 | if (error == ENOENT) |
2455 | error = 0; | |
c82af904 MD |
2456 | return(error); |
2457 | } | |
2458 | ||
ae744f81 TK |
2459 | /* |
2460 | * Return a pointer to node's parent. If there is no error, | |
2461 | * *parent_index is set to an index of parent's elm that points | |
2462 | * to this node. | |
2463 | */ | |
c82af904 | 2464 | hammer_node_t |
82010f9f MD |
2465 | hammer_btree_get_parent(hammer_transaction_t trans, hammer_node_t node, |
2466 | int *parent_indexp, int *errorp, int try_exclusive) | |
c82af904 MD |
2467 | { |
2468 | hammer_node_t parent; | |
2469 | hammer_btree_elm_t elm; | |
2470 | int i; | |
2471 | ||
2472 | /* | |
2473 | * Get the node | |
2474 | */ | |
82010f9f | 2475 | parent = hammer_get_node(trans, node->ondisk->parent, 0, errorp); |
c82af904 MD |
2476 | if (*errorp) { |
2477 | KKASSERT(parent == NULL); | |
2478 | return(NULL); | |
2479 | } | |
2480 | KKASSERT ((parent->flags & HAMMER_NODE_DELETED) == 0); | |
2481 | ||
2482 | /* | |
2483 | * Lock the node | |
2484 | */ | |
2485 | if (try_exclusive) { | |
2486 | if (hammer_lock_ex_try(&parent->lock)) { | |
2487 | hammer_rel_node(parent); | |
2488 | *errorp = EDEADLK; | |
2489 | return(NULL); | |
2490 | } | |
2491 | } else { | |
2492 | hammer_lock_sh(&parent->lock); | |
2493 | } | |
2494 | ||
2495 | /* | |
2496 | * Figure out which element in the parent is pointing to the | |
2497 | * child. | |
2498 | */ | |
2499 | if (node->ondisk->count) { | |
2500 | i = hammer_btree_search_node(&node->ondisk->elms[0].base, | |
2501 | parent->ondisk); | |
2502 | } else { | |
2503 | i = 0; | |
2504 | } | |
2505 | while (i < parent->ondisk->count) { | |
2506 | elm = &parent->ondisk->elms[i]; | |
2507 | if (elm->internal.subtree_offset == node->node_offset) | |
2508 | break; | |
2509 | ++i; | |
2510 | } | |
2511 | if (i == parent->ondisk->count) { | |
2512 | hammer_unlock(&parent->lock); | |
5134aacd | 2513 | hpanic("Bad B-Tree link: parent %p node %p", parent, node); |
c82af904 MD |
2514 | } |
2515 | *parent_indexp = i; | |
2516 | KKASSERT(*errorp == 0); | |
2517 | return(parent); | |
2518 | } | |
2519 | ||
7f7c1f84 | 2520 | /* |
fe7678ee MD |
2521 | * The element (elm) has been moved to a new internal node (node). |
2522 | * | |
2523 | * If the element represents a pointer to an internal node that node's | |
2524 | * parent must be adjusted to the element's new location. | |
2525 | * | |
6a37e7e4 | 2526 | * XXX deadlock potential here with our exclusive locks |
7f7c1f84 | 2527 | */ |
7f7c1f84 | 2528 | int |
90f96c37 | 2529 | btree_set_parent_of_child(hammer_transaction_t trans, hammer_node_t node, |
36f82b23 | 2530 | hammer_btree_elm_t elm) |
7f7c1f84 | 2531 | { |
7f7c1f84 MD |
2532 | hammer_node_t child; |
2533 | int error; | |
2534 | ||
2535 | error = 0; | |
2536 | ||
1424c922 | 2537 | if (hammer_is_internal_node_elm(elm)) { |
82010f9f | 2538 | child = hammer_get_node(trans, elm->internal.subtree_offset, |
19619882 | 2539 | 0, &error); |
7f7c1f84 | 2540 | if (error == 0) { |
c9b9e29d | 2541 | hammer_modify_node_field(trans, child, parent); |
7f7c1f84 | 2542 | child->ondisk->parent = node->node_offset; |
10a5d1ba | 2543 | hammer_modify_node_done(child); |
7f7c1f84 MD |
2544 | hammer_rel_node(child); |
2545 | } | |
7f7c1f84 MD |
2546 | } |
2547 | return(error); | |
2548 | } | |
2549 | ||
1775b6a0 MD |
2550 | /* |
2551 | * Initialize the root of a recursive B-Tree node lock list structure. | |
2552 | */ | |
2553 | void | |
2554 | hammer_node_lock_init(hammer_node_lock_t parent, hammer_node_t node) | |
2555 | { | |
2556 | TAILQ_INIT(&parent->list); | |
2557 | parent->parent = NULL; | |
2558 | parent->node = node; | |
2559 | parent->index = -1; | |
2560 | parent->count = node->ondisk->count; | |
2561 | parent->copy = NULL; | |
2562 | parent->flags = 0; | |
2563 | } | |
2564 | ||
24cf83d2 MD |
2565 | /* |
2566 | * Initialize a cache of hammer_node_lock's including space allocated | |
2567 | * for node copies. | |
2568 | * | |
2569 | * This is used by the rebalancing code to preallocate the copy space | |
2570 | * for ~4096 B-Tree nodes (16MB of data) prior to acquiring any HAMMER | |
2571 | * locks, otherwise we can blow out the pageout daemon's emergency | |
2572 | * reserve and deadlock it. | |
2573 | * | |
2574 | * NOTE: HAMMER_NODE_LOCK_LCACHE is not set on items cached in the lcache. | |
2575 | * The flag is set when the item is pulled off the cache for use. | |
2576 | */ | |
2577 | void | |
2578 | hammer_btree_lcache_init(hammer_mount_t hmp, hammer_node_lock_t lcache, | |
2579 | int depth) | |
2580 | { | |
2581 | hammer_node_lock_t item; | |
2582 | int count; | |
2583 | ||
2584 | for (count = 1; depth; --depth) | |
2585 | count *= HAMMER_BTREE_LEAF_ELMS; | |
2586 | bzero(lcache, sizeof(*lcache)); | |
2587 | TAILQ_INIT(&lcache->list); | |
2588 | while (count) { | |
2589 | item = kmalloc(sizeof(*item), hmp->m_misc, M_WAITOK|M_ZERO); | |
2590 | item->copy = kmalloc(sizeof(*item->copy), | |
2591 | hmp->m_misc, M_WAITOK); | |
2592 | TAILQ_INIT(&item->list); | |
2593 | TAILQ_INSERT_TAIL(&lcache->list, item, entry); | |
2594 | --count; | |
2595 | } | |
2596 | } | |
2597 | ||
2598 | void | |
2599 | hammer_btree_lcache_free(hammer_mount_t hmp, hammer_node_lock_t lcache) | |
2600 | { | |
2601 | hammer_node_lock_t item; | |
2602 | ||
2603 | while ((item = TAILQ_FIRST(&lcache->list)) != NULL) { | |
2604 | TAILQ_REMOVE(&lcache->list, item, entry); | |
2605 | KKASSERT(item->copy); | |
2606 | KKASSERT(TAILQ_EMPTY(&item->list)); | |
2607 | kfree(item->copy, hmp->m_misc); | |
2608 | kfree(item, hmp->m_misc); | |
2609 | } | |
2610 | KKASSERT(lcache->copy == NULL); | |
2611 | } | |
2612 | ||
b33e2cc0 MD |
2613 | /* |
2614 | * Exclusively lock all the children of node. This is used by the split | |
2615 | * code to prevent anyone from accessing the children of a cursor node | |
2616 | * while we fix-up its parent offset. | |
2617 | * | |
2618 | * If we don't lock the children we can really mess up cursors which block | |
2619 | * trying to cursor-up into our node. | |
2620 | * | |
b33e2cc0 MD |
2621 | * On failure EDEADLK (or some other error) is returned. If a deadlock |
2622 | * error is returned the cursor is adjusted to block on termination. | |
1775b6a0 MD |
2623 | * |
2624 | * The caller is responsible for managing parent->node, the root's node | |
2625 | * is usually aliased from a cursor. | |
b33e2cc0 MD |
2626 | */ |
2627 | int | |
1775b6a0 | 2628 | hammer_btree_lock_children(hammer_cursor_t cursor, int depth, |
24cf83d2 MD |
2629 | hammer_node_lock_t parent, |
2630 | hammer_node_lock_t lcache) | |
b33e2cc0 MD |
2631 | { |
2632 | hammer_node_t node; | |
1775b6a0 | 2633 | hammer_node_lock_t item; |
b33e2cc0 MD |
2634 | hammer_node_ondisk_t ondisk; |
2635 | hammer_btree_elm_t elm; | |
b33e2cc0 | 2636 | hammer_node_t child; |
ba2be8e9 | 2637 | hammer_mount_t hmp; |
b33e2cc0 MD |
2638 | int error; |
2639 | int i; | |
2640 | ||
1775b6a0 | 2641 | node = parent->node; |
b33e2cc0 MD |
2642 | ondisk = node->ondisk; |
2643 | error = 0; | |
bac808fe | 2644 | hmp = cursor->trans->hmp; |
7bc5b8c2 | 2645 | |
5cbc7d52 TK |
2646 | if (ondisk->type != HAMMER_BTREE_TYPE_INTERNAL) |
2647 | return(0); /* This could return non-zero */ | |
2648 | ||
7bc5b8c2 MD |
2649 | /* |
2650 | * We really do not want to block on I/O with exclusive locks held, | |
1775b6a0 MD |
2651 | * pre-get the children before trying to lock the mess. This is |
2652 | * only done one-level deep for now. | |
7bc5b8c2 MD |
2653 | */ |
2654 | for (i = 0; i < ondisk->count; ++i) { | |
cb51be26 | 2655 | ++hammer_stats_btree_elements; |
7bc5b8c2 | 2656 | elm = &ondisk->elms[i]; |
5cbc7d52 TK |
2657 | child = hammer_get_node(cursor->trans, |
2658 | elm->internal.subtree_offset, | |
2659 | 0, &error); | |
2660 | if (child) | |
2661 | hammer_rel_node(child); | |
7bc5b8c2 MD |
2662 | } |
2663 | ||
2664 | /* | |
2665 | * Do it for real | |
2666 | */ | |
b33e2cc0 | 2667 | for (i = 0; error == 0 && i < ondisk->count; ++i) { |
cb51be26 | 2668 | ++hammer_stats_btree_elements; |
b33e2cc0 MD |
2669 | elm = &ondisk->elms[i]; |
2670 | ||
5cbc7d52 TK |
2671 | KKASSERT(elm->internal.subtree_offset != 0); |
2672 | child = hammer_get_node(cursor->trans, | |
2673 | elm->internal.subtree_offset, | |
2674 | 0, &error); | |
b33e2cc0 MD |
2675 | if (child) { |
2676 | if (hammer_lock_ex_try(&child->lock) != 0) { | |
2677 | if (cursor->deadlk_node == NULL) { | |
1ff9f58e | 2678 | cursor->deadlk_node = child; |
b33e2cc0 MD |
2679 | hammer_ref_node(cursor->deadlk_node); |
2680 | } | |
2681 | error = EDEADLK; | |
a84a197d | 2682 | hammer_rel_node(child); |
b33e2cc0 | 2683 | } else { |
24cf83d2 MD |
2684 | if (lcache) { |
2685 | item = TAILQ_FIRST(&lcache->list); | |
2686 | KKASSERT(item != NULL); | |
2687 | item->flags |= HAMMER_NODE_LOCK_LCACHE; | |
653fa4cd | 2688 | TAILQ_REMOVE(&lcache->list, item, entry); |
24cf83d2 MD |
2689 | } else { |
2690 | item = kmalloc(sizeof(*item), | |
2691 | hmp->m_misc, | |
2692 | M_WAITOK|M_ZERO); | |
2693 | TAILQ_INIT(&item->list); | |
2694 | } | |
2695 | ||
1775b6a0 | 2696 | TAILQ_INSERT_TAIL(&parent->list, item, entry); |
1775b6a0 | 2697 | item->parent = parent; |
b33e2cc0 | 2698 | item->node = child; |
1775b6a0 MD |
2699 | item->index = i; |
2700 | item->count = child->ondisk->count; | |
2701 | ||
2702 | /* | |
2703 | * Recurse (used by the rebalancing code) | |
2704 | */ | |
2705 | if (depth > 1 && elm->base.btype == HAMMER_BTREE_TYPE_INTERNAL) { | |
2706 | error = hammer_btree_lock_children( | |
2707 | cursor, | |
2708 | depth - 1, | |
24cf83d2 MD |
2709 | item, |
2710 | lcache); | |
1775b6a0 | 2711 | } |
b33e2cc0 MD |
2712 | } |
2713 | } | |
2714 | } | |
2715 | if (error) | |
24cf83d2 | 2716 | hammer_btree_unlock_children(hmp, parent, lcache); |
b33e2cc0 MD |
2717 | return(error); |
2718 | } | |
2719 | ||
1775b6a0 MD |
2720 | /* |
2721 | * Create an in-memory copy of all B-Tree nodes listed, recursively, | |
2722 | * including the parent. | |
2723 | */ | |
2724 | void | |
2725 | hammer_btree_lock_copy(hammer_cursor_t cursor, hammer_node_lock_t parent) | |
2726 | { | |
2727 | hammer_mount_t hmp = cursor->trans->hmp; | |
2728 | hammer_node_lock_t item; | |
2729 | ||
2730 | if (parent->copy == NULL) { | |
24cf83d2 MD |
2731 | KKASSERT((parent->flags & HAMMER_NODE_LOCK_LCACHE) == 0); |
2732 | parent->copy = kmalloc(sizeof(*parent->copy), | |
2733 | hmp->m_misc, M_WAITOK); | |
1775b6a0 | 2734 | } |
24cf83d2 MD |
2735 | KKASSERT((parent->flags & HAMMER_NODE_LOCK_UPDATED) == 0); |
2736 | *parent->copy = *parent->node->ondisk; | |
1775b6a0 MD |
2737 | TAILQ_FOREACH(item, &parent->list, entry) { |
2738 | hammer_btree_lock_copy(cursor, item); | |
2739 | } | |
2740 | } | |
b33e2cc0 MD |
2741 | |
2742 | /* | |
1775b6a0 | 2743 | * Recursively sync modified copies to the media. |
b33e2cc0 | 2744 | */ |
7ddc70d1 | 2745 | int |
1775b6a0 | 2746 | hammer_btree_sync_copy(hammer_cursor_t cursor, hammer_node_lock_t parent) |
b33e2cc0 | 2747 | { |
1775b6a0 | 2748 | hammer_node_lock_t item; |
7ddc70d1 | 2749 | int count = 0; |
1775b6a0 MD |
2750 | |
2751 | if (parent->flags & HAMMER_NODE_LOCK_UPDATED) { | |
7ddc70d1 | 2752 | ++count; |
1775b6a0 MD |
2753 | hammer_modify_node_all(cursor->trans, parent->node); |
2754 | *parent->node->ondisk = *parent->copy; | |
2755 | hammer_modify_node_done(parent->node); | |
2756 | if (parent->copy->type == HAMMER_BTREE_TYPE_DELETED) { | |
250aec18 | 2757 | hammer_flush_node(parent->node, 0); |
1775b6a0 MD |
2758 | hammer_delete_node(cursor->trans, parent->node); |
2759 | } | |
2760 | } | |
2761 | TAILQ_FOREACH(item, &parent->list, entry) { | |
7ddc70d1 | 2762 | count += hammer_btree_sync_copy(cursor, item); |
1775b6a0 | 2763 | } |
7ddc70d1 | 2764 | return(count); |
1775b6a0 | 2765 | } |
b33e2cc0 | 2766 | |
1775b6a0 MD |
2767 | /* |
2768 | * Release previously obtained node locks. The caller is responsible for | |
2769 | * cleaning up parent->node itself (its usually just aliased from a cursor), | |
2770 | * but this function will take care of the copies. | |
24cf83d2 MD |
2771 | * |
2772 | * NOTE: The root node is not placed in the lcache and node->copy is not | |
2773 | * deallocated when lcache != NULL. | |
1775b6a0 MD |
2774 | */ |
2775 | void | |
24cf83d2 MD |
2776 | hammer_btree_unlock_children(hammer_mount_t hmp, hammer_node_lock_t parent, |
2777 | hammer_node_lock_t lcache) | |
1775b6a0 MD |
2778 | { |
2779 | hammer_node_lock_t item; | |
24cf83d2 | 2780 | hammer_node_ondisk_t copy; |
1775b6a0 | 2781 | |
1775b6a0 MD |
2782 | while ((item = TAILQ_FIRST(&parent->list)) != NULL) { |
2783 | TAILQ_REMOVE(&parent->list, item, entry); | |
24cf83d2 | 2784 | hammer_btree_unlock_children(hmp, item, lcache); |
b33e2cc0 MD |
2785 | hammer_unlock(&item->node->lock); |
2786 | hammer_rel_node(item->node); | |
24cf83d2 MD |
2787 | if (lcache) { |
2788 | /* | |
2789 | * NOTE: When placing the item back in the lcache | |
2790 | * the flag is cleared by the bzero(). | |
2791 | * Remaining fields are cleared as a safety | |
2792 | * measure. | |
2793 | */ | |
2794 | KKASSERT(item->flags & HAMMER_NODE_LOCK_LCACHE); | |
2795 | KKASSERT(TAILQ_EMPTY(&item->list)); | |
2796 | copy = item->copy; | |
2797 | bzero(item, sizeof(*item)); | |
2798 | TAILQ_INIT(&item->list); | |
2799 | item->copy = copy; | |
2800 | if (copy) | |
2801 | bzero(copy, sizeof(*copy)); | |
2802 | TAILQ_INSERT_TAIL(&lcache->list, item, entry); | |
2803 | } else { | |
2804 | kfree(item, hmp->m_misc); | |
2805 | } | |
2806 | } | |
2807 | if (parent->copy && (parent->flags & HAMMER_NODE_LOCK_LCACHE) == 0) { | |
2808 | kfree(parent->copy, hmp->m_misc); | |
2809 | parent->copy = NULL; /* safety */ | |
b33e2cc0 MD |
2810 | } |
2811 | } | |
2812 | ||
8cd0a023 MD |
2813 | /************************************************************************ |
2814 | * MISCELLANIOUS SUPPORT * | |
2815 | ************************************************************************/ | |
2816 | ||
2817 | /* | |
d26d0ae9 | 2818 | * Compare two B-Tree elements, return -N, 0, or +N (e.g. similar to strcmp). |
8cd0a023 | 2819 | * |
d113fda1 | 2820 | * Note that for this particular function a return value of -1, 0, or +1 |
9582c7da | 2821 | * can denote a match if create_tid is otherwise discounted. A create_tid |
d5530d22 | 2822 | * of zero is considered to be 'infinity' in comparisons. |
d113fda1 | 2823 | * |
8cd0a023 | 2824 | * See also hammer_rec_rb_compare() and hammer_rec_cmp() in hammer_object.c. |
8cd0a023 MD |
2825 | */ |
2826 | int | |
2827 | hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2) | |
2828 | { | |
2f85fa4d MD |
2829 | if (key1->localization < key2->localization) |
2830 | return(-5); | |
2831 | if (key1->localization > key2->localization) | |
2832 | return(5); | |
2833 | ||
d26d0ae9 MD |
2834 | if (key1->obj_id < key2->obj_id) |
2835 | return(-4); | |
2836 | if (key1->obj_id > key2->obj_id) | |
2837 | return(4); | |
8cd0a023 | 2838 | |
d26d0ae9 MD |
2839 | if (key1->rec_type < key2->rec_type) |
2840 | return(-3); | |
2841 | if (key1->rec_type > key2->rec_type) | |
2842 | return(3); | |
8cd0a023 | 2843 | |
8cd0a023 MD |
2844 | if (key1->key < key2->key) |
2845 | return(-2); | |
2846 | if (key1->key > key2->key) | |
2847 | return(2); | |
d113fda1 | 2848 | |
d5530d22 | 2849 | /* |
9582c7da MD |
2850 | * A create_tid of zero indicates a record which is undeletable |
2851 | * and must be considered to have a value of positive infinity. | |
d5530d22 | 2852 | */ |
9582c7da MD |
2853 | if (key1->create_tid == 0) { |
2854 | if (key2->create_tid == 0) | |
d5530d22 MD |
2855 | return(0); |
2856 | return(1); | |
2857 | } | |
9582c7da | 2858 | if (key2->create_tid == 0) |
d5530d22 | 2859 | return(-1); |
9582c7da | 2860 | if (key1->create_tid < key2->create_tid) |
d113fda1 | 2861 | return(-1); |
9582c7da | 2862 | if (key1->create_tid > key2->create_tid) |
d113fda1 | 2863 | return(1); |
8cd0a023 MD |
2864 | return(0); |
2865 | } | |
2866 | ||
c0ade690 | 2867 | /* |
d5530d22 MD |
2868 | * Test a timestamp against an element to determine whether the |
2869 | * element is visible. A timestamp of 0 means 'infinity'. | |
c0ade690 MD |
2870 | */ |
2871 | int | |
d5530d22 | 2872 | hammer_btree_chkts(hammer_tid_t asof, hammer_base_elm_t base) |
c0ade690 | 2873 | { |
d5530d22 MD |
2874 | if (asof == 0) { |
2875 | if (base->delete_tid) | |
2876 | return(1); | |
2877 | return(0); | |
2878 | } | |
2879 | if (asof < base->create_tid) | |
d26d0ae9 | 2880 | return(-1); |
d5530d22 | 2881 | if (base->delete_tid && asof >= base->delete_tid) |
d26d0ae9 | 2882 | return(1); |
c0ade690 MD |
2883 | return(0); |
2884 | } | |
2885 | ||
8cd0a023 MD |
2886 | /* |
2887 | * Create a separator half way inbetween key1 and key2. For fields just | |
d5530d22 MD |
2888 | * one unit apart, the separator will match key2. key1 is on the left-hand |
2889 | * side and key2 is on the right-hand side. | |
8cd0a023 | 2890 | * |
9391cded | 2891 | * key2 must be >= the separator. It is ok for the separator to match key2. |
36f82b23 | 2892 | * |
9391cded MD |
2893 | * NOTE: Even if key1 does not match key2, the separator may wind up matching |
2894 | * key2. | |
2895 | * | |
2896 | * NOTE: It might be beneficial to just scrap this whole mess and just | |
2897 | * set the separator to key2. | |
8cd0a023 MD |
2898 | */ |
2899 | #define MAKE_SEPARATOR(key1, key2, dest, field) \ | |
2900 | dest->field = key1->field + ((key2->field - key1->field + 1) >> 1); | |
2901 | ||
2902 | static void | |
2903 | hammer_make_separator(hammer_base_elm_t key1, hammer_base_elm_t key2, | |
2904 | hammer_base_elm_t dest) | |
2905 | { | |
2906 | bzero(dest, sizeof(*dest)); | |
d5530d22 | 2907 | |
9391cded MD |
2908 | dest->rec_type = key2->rec_type; |
2909 | dest->key = key2->key; | |
2f85fa4d | 2910 | dest->obj_id = key2->obj_id; |
9391cded MD |
2911 | dest->create_tid = key2->create_tid; |
2912 | ||
2f85fa4d MD |
2913 | MAKE_SEPARATOR(key1, key2, dest, localization); |
2914 | if (key1->localization == key2->localization) { | |
2915 | MAKE_SEPARATOR(key1, key2, dest, obj_id); | |
2916 | if (key1->obj_id == key2->obj_id) { | |
2917 | MAKE_SEPARATOR(key1, key2, dest, rec_type); | |
2918 | if (key1->rec_type == key2->rec_type) { | |
2919 | MAKE_SEPARATOR(key1, key2, dest, key); | |
2920 | /* | |
2921 | * Don't bother creating a separator for | |
2922 | * create_tid, which also conveniently avoids | |
2923 | * having to handle the create_tid == 0 | |
2924 | * (infinity) case. Just leave create_tid | |
2925 | * set to key2. | |
2926 | * | |
2927 | * Worst case, dest matches key2 exactly, | |
2928 | * which is acceptable. | |
2929 | */ | |
2930 | } | |
d5530d22 | 2931 | } |
d113fda1 | 2932 | } |
8cd0a023 MD |
2933 | } |
2934 | ||
2935 | #undef MAKE_SEPARATOR | |
2936 | ||
2937 | /* | |
2938 | * Return whether a generic internal or leaf node is full | |
2939 | */ | |
b70819e9 TK |
2940 | static __inline |
2941 | int | |
8cd0a023 | 2942 | btree_node_is_full(hammer_node_ondisk_t node) |
8cd0a023 | 2943 | { |
36211fc6 TK |
2944 | int n; |
2945 | ||
23b37863 | 2946 | n = hammer_node_max_elements(node->type); |
36211fc6 | 2947 | if (n == -1) |
23b37863 TK |
2948 | hpanic("bad type %d", node->type); |
2949 | ||
2950 | return(n == node->count); | |
8cd0a023 | 2951 | } |
8cd0a023 | 2952 | |
c0ade690 MD |
2953 | void |
2954 | hammer_print_btree_node(hammer_node_ondisk_t ondisk) | |
2955 | { | |
a17eeab0 | 2956 | int i, n; |
c0ade690 | 2957 | |
35a5249b | 2958 | kprintf("node %p count=%d parent=%016jx type=%c\n", |
973c11b9 | 2959 | ondisk, ondisk->count, |
35a5249b | 2960 | (intmax_t)ondisk->parent, ondisk->type); |
c0ade690 | 2961 | |
a17eeab0 TK |
2962 | switch (ondisk->type) { |
2963 | case HAMMER_BTREE_TYPE_INTERNAL: | |
2964 | n = ondisk->count + 1; /* count is NOT boundary inclusive */ | |
2965 | break; | |
2966 | case HAMMER_BTREE_TYPE_LEAF: | |
2967 | n = ondisk->count; /* there is no boundary */ | |
2968 | break; | |
2969 | default: | |
2970 | return; /* nothing to do */ | |
2971 | } | |
2972 | ||
c0ade690 | 2973 | /* |
a17eeab0 | 2974 | * Dump elements including boundary. |
c0ade690 | 2975 | */ |
a17eeab0 TK |
2976 | for (i = 0; i < n; ++i) { |
2977 | kprintf(" %2d", i); | |
2978 | hammer_print_btree_elm(&ondisk->elms[i]); | |
c0ade690 MD |
2979 | } |
2980 | } | |
2981 | ||
2982 | void | |
a17eeab0 | 2983 | hammer_print_btree_elm(hammer_btree_elm_t elm) |
c0ade690 | 2984 | { |
35a5249b TK |
2985 | kprintf("\tobj_id = %016jx\n", (intmax_t)elm->base.obj_id); |
2986 | kprintf("\tkey = %016jx\n", (intmax_t)elm->base.key); | |
2987 | kprintf("\tcreate_tid = %016jx\n", (intmax_t)elm->base.create_tid); | |
2988 | kprintf("\tdelete_tid = %016jx\n", (intmax_t)elm->base.delete_tid); | |
c0ade690 MD |
2989 | kprintf("\trec_type = %04x\n", elm->base.rec_type); |
2990 | kprintf("\tobj_type = %02x\n", elm->base.obj_type); | |
c3378ec7 TK |
2991 | kprintf("\tbtype = %02x (%c)\n", elm->base.btype, |
2992 | hammer_elm_btype(elm)); | |
c1789a39 | 2993 | kprintf("\tlocalization = %08x\n", elm->base.localization); |
fe7678ee | 2994 | |
a17eeab0 | 2995 | if (hammer_is_internal_node_elm(elm)) { |
35a5249b TK |
2996 | kprintf("\tsubtree_off = %016jx\n", |
2997 | (intmax_t)elm->internal.subtree_offset); | |
a17eeab0 | 2998 | } else if (hammer_is_leaf_node_elm(elm)) { |
35a5249b TK |
2999 | kprintf("\tdata_offset = %016jx\n", |
3000 | (intmax_t)elm->leaf.data_offset); | |
c0ade690 MD |
3001 | kprintf("\tdata_len = %08x\n", elm->leaf.data_len); |
3002 | kprintf("\tdata_crc = %08x\n", elm->leaf.data_crc); | |
3003 | } | |
3004 | } | |
fe4fc0c0 TK |
3005 | |
3006 | static __inline | |
3007 | void | |
3008 | hammer_debug_btree_elm(hammer_cursor_t cursor, hammer_btree_elm_t elm, | |
3009 | const char *s, int res) | |
3010 | { | |
35a5249b TK |
3011 | hkprintf("%-8s %016jx[%02d] %c " |
3012 | "lo=%08x obj=%016jx rec=%02x key=%016jx tid=%016jx td=%p " | |
fe4fc0c0 TK |
3013 | "r=%d\n", |
3014 | s, | |
35a5249b | 3015 | (intmax_t)cursor->node->node_offset, |
fe4fc0c0 TK |
3016 | cursor->index, |
3017 | hammer_elm_btype(elm), | |
3018 | elm->base.localization, | |
35a5249b | 3019 | (intmax_t)elm->base.obj_id, |
fe4fc0c0 | 3020 | elm->base.rec_type, |
35a5249b TK |
3021 | (intmax_t)elm->base.key, |
3022 | (intmax_t)elm->base.create_tid, | |
fe4fc0c0 TK |
3023 | curthread, |
3024 | res); | |
3025 | } | |
3026 | ||
3027 | static __inline | |
3028 | void | |
3029 | hammer_debug_btree_parent(hammer_cursor_t cursor, const char *s) | |
3030 | { | |
3031 | hammer_btree_elm_t elm = | |
3032 | &cursor->parent->ondisk->elms[cursor->parent_index]; | |
3033 | ||
35a5249b TK |
3034 | hkprintf("%-8s %016jx[%d] %c " |
3035 | "(%016jx/%016jx %016jx/%016jx) (%p/%p %p/%p)\n", | |
fe4fc0c0 | 3036 | s, |
35a5249b | 3037 | (intmax_t)cursor->parent->node_offset, |
fe4fc0c0 TK |
3038 | cursor->parent_index, |
3039 | hammer_elm_btype(elm), | |
35a5249b TK |
3040 | (intmax_t)cursor->left_bound->obj_id, |
3041 | (intmax_t)elm->internal.base.obj_id, | |
3042 | (intmax_t)cursor->right_bound->obj_id, | |
3043 | (intmax_t)(elm + 1)->internal.base.obj_id, | |
fe4fc0c0 TK |
3044 | cursor->left_bound, |
3045 | elm, | |
3046 | cursor->right_bound, | |
3047 | elm + 1); | |
3048 | } |