HAMMER 56C/Many: Performance tuning - MEDIA STRUCTURES CHANGED!
[dragonfly.git] / sys / vfs / hammer / hammer_btree.c
CommitLineData
427e5fc6 1/*
b84de5af 2 * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved.
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3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
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.
20 *
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.
33 *
4a2796f3 34 * $DragonFly: src/sys/vfs/hammer/hammer_btree.c,v 1.56 2008/06/20 05:38:26 dillon Exp $
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35 */
36
37/*
8cd0a023 38 * HAMMER B-Tree index
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39 *
40 * HAMMER implements a modified B+Tree. In documentation this will
9944ae54 41 * simply be refered to as the HAMMER B-Tree. Basically a HAMMER B-Tree
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42 * looks like a B+Tree (A B-Tree which stores its records only at the leafs
43 * of the tree), but adds two additional boundary elements which describe
44 * the left-most and right-most element a node is able to represent. In
8cd0a023 45 * otherwords, we have boundary elements at the two ends of a B-Tree node
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46 * instead of sub-tree pointers.
47 *
8cd0a023 48 * A B-Tree internal node looks like this:
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49 *
50 * B N N N N N N B <-- boundary and internal elements
51 * S S S S S S S <-- subtree pointers
52 *
8cd0a023 53 * A B-Tree leaf node basically looks like this:
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54 *
55 * L L L L L L L L <-- leaf elemenets
56 *
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57 * The radix for an internal node is 1 less then a leaf but we get a
58 * number of significant benefits for our troubles.
427e5fc6 59 *
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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 *
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68 * B-Trees also make the stacking of trees fairly straightforward.
69 *
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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
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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).
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80 */
81#include "hammer.h"
82#include <sys/buf.h>
83#include <sys/buf2.h>
66325755 84
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85static int btree_search(hammer_cursor_t cursor, int flags);
86static int btree_split_internal(hammer_cursor_t cursor);
87static int btree_split_leaf(hammer_cursor_t cursor);
46fe7ae1 88static int btree_remove(hammer_cursor_t cursor);
fe7678ee 89static int btree_node_is_full(hammer_node_ondisk_t node);
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90static void hammer_make_separator(hammer_base_elm_t key1,
91 hammer_base_elm_t key2, hammer_base_elm_t dest);
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92
93/*
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94 * Iterate records after a search. The cursor is iterated forwards past
95 * the current record until a record matching the key-range requirements
96 * is found. ENOENT is returned if the iteration goes past the ending
6a37e7e4 97 * key.
66325755 98 *
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99 * The iteration is inclusive of key_beg and can be inclusive or exclusive
100 * of key_end depending on whether HAMMER_CURSOR_END_INCLUSIVE is set.
66325755 101 *
eaeff70d 102 * When doing an as-of search (cursor->asof != 0), key_beg.create_tid
9582c7da 103 * may be modified by B-Tree functions.
d5530d22 104 *
8cd0a023 105 * cursor->key_beg may or may not be modified by this function during
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106 * the iteration. XXX future - in case of an inverted lock we may have
107 * to reinitiate the lookup and set key_beg to properly pick up where we
108 * left off.
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109 *
110 * NOTE! EDEADLK *CANNOT* be returned by this procedure.
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111 */
112int
8cd0a023 113hammer_btree_iterate(hammer_cursor_t cursor)
66325755 114{
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115 hammer_node_ondisk_t node;
116 hammer_btree_elm_t elm;
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117 int error;
118 int r;
119 int s;
120
121 /*
8cd0a023 122 * Skip past the current record
66325755 123 */
8cd0a023 124 node = cursor->node->ondisk;
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125 if (node == NULL)
126 return(ENOENT);
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127 if (cursor->index < node->count &&
128 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
66325755 129 ++cursor->index;
c0ade690 130 }
66325755 131
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132 /*
133 * Loop until an element is found or we are done.
134 */
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135 for (;;) {
136 /*
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137 * We iterate up the tree and then index over one element
138 * while we are at the last element in the current node.
139 *
47197d71 140 * If we are at the root of the filesystem, cursor_up
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141 * returns ENOENT.
142 *
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143 * XXX this could be optimized by storing the information in
144 * the parent reference.
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145 *
146 * XXX we can lose the node lock temporarily, this could mess
147 * up our scan.
66325755 148 */
47637bff 149 ++hammer_stats_btree_iterations;
8cd0a023 150 if (cursor->index == node->count) {
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151 if (hammer_debug_btree) {
152 kprintf("BRACKETU %016llx[%d] -> %016llx[%d] (td=%p)\n",
153 cursor->node->node_offset,
154 cursor->index,
155 (cursor->parent ? cursor->parent->node_offset : -1),
156 cursor->parent_index,
157 curthread);
158 }
159 KKASSERT(cursor->parent == NULL || cursor->parent->ondisk->elms[cursor->parent_index].internal.subtree_offset == cursor->node->node_offset);
6a37e7e4 160 error = hammer_cursor_up(cursor);
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161 if (error)
162 break;
46fe7ae1 163 /* reload stale pointer */
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164 node = cursor->node->ondisk;
165 KKASSERT(cursor->index != node->count);
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166
167 /*
168 * If we are reblocking we want to return internal
169 * nodes.
170 */
171 if (cursor->flags & HAMMER_CURSOR_REBLOCKING) {
172 cursor->flags |= HAMMER_CURSOR_ATEDISK;
173 return(0);
174 }
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175 ++cursor->index;
176 continue;
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177 }
178
179 /*
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180 * Check internal or leaf element. Determine if the record
181 * at the cursor has gone beyond the end of our range.
66325755 182 *
47197d71 183 * We recurse down through internal nodes.
66325755 184 */
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185 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
186 elm = &node->elms[cursor->index];
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187 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
188 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
b3deaf57 189 if (hammer_debug_btree) {
2f85fa4d 190 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d (td=%p)\n",
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191 cursor->node->node_offset,
192 cursor->index,
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193 elm[0].internal.base.obj_id,
194 elm[0].internal.base.rec_type,
195 elm[0].internal.base.key,
2f85fa4d 196 elm[0].internal.base.localization,
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197 r,
198 curthread
b3deaf57 199 );
2f85fa4d 200 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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201 cursor->node->node_offset,
202 cursor->index + 1,
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203 elm[1].internal.base.obj_id,
204 elm[1].internal.base.rec_type,
205 elm[1].internal.base.key,
2f85fa4d 206 elm[1].internal.base.localization,
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207 s
208 );
209 }
210
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211 if (r < 0) {
212 error = ENOENT;
213 break;
66325755 214 }
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215 if (r == 0 && (cursor->flags &
216 HAMMER_CURSOR_END_INCLUSIVE) == 0) {
d26d0ae9 217 error = ENOENT;
8cd0a023 218 break;
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219 }
220 KKASSERT(s <= 0);
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221
222 /*
f36a9737 223 * Better not be zero
6a37e7e4 224 */
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225 KKASSERT(elm->internal.subtree_offset != 0);
226
227 error = hammer_cursor_down(cursor);
228 if (error)
229 break;
230 KKASSERT(cursor->index == 0);
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231 /* reload stale pointer */
232 node = cursor->node->ondisk;
fe7678ee 233 continue;
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234 } else {
235 elm = &node->elms[cursor->index];
236 r = hammer_btree_cmp(&cursor->key_end, &elm->base);
b3deaf57 237 if (hammer_debug_btree) {
2f85fa4d 238 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
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239 cursor->node->node_offset,
240 cursor->index,
241 (elm[0].leaf.base.btype ?
242 elm[0].leaf.base.btype : '?'),
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243 elm[0].leaf.base.obj_id,
244 elm[0].leaf.base.rec_type,
245 elm[0].leaf.base.key,
2f85fa4d 246 elm[0].leaf.base.localization,
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247 r
248 );
249 }
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250 if (r < 0) {
251 error = ENOENT;
252 break;
253 }
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254
255 /*
256 * We support both end-inclusive and
257 * end-exclusive searches.
258 */
259 if (r == 0 &&
260 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
261 error = ENOENT;
262 break;
263 }
264
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265 switch(elm->leaf.base.btype) {
266 case HAMMER_BTREE_TYPE_RECORD:
267 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
268 hammer_btree_chkts(cursor->asof, &elm->base)) {
269 ++cursor->index;
270 continue;
271 }
272 break;
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273 default:
274 error = EINVAL;
275 break;
d26d0ae9 276 }
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277 if (error)
278 break;
66325755 279 }
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280 /*
281 * node pointer invalid after loop
282 */
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283
284 /*
d26d0ae9 285 * Return entry
66325755 286 */
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287 if (hammer_debug_btree) {
288 int i = cursor->index;
289 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 290 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
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291 cursor->node, i,
292 elm->internal.base.obj_id,
293 elm->internal.base.rec_type,
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294 elm->internal.base.key,
295 elm->internal.base.localization
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296 );
297 }
d26d0ae9 298 return(0);
427e5fc6 299 }
66325755 300 return(error);
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301}
302
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303/*
304 * Iterate in the reverse direction. This is used by the pruning code to
305 * avoid overlapping records.
306 */
307int
308hammer_btree_iterate_reverse(hammer_cursor_t cursor)
309{
310 hammer_node_ondisk_t node;
311 hammer_btree_elm_t elm;
312 int error;
313 int r;
314 int s;
315
316 /*
317 * Skip past the current record. For various reasons the cursor
318 * may end up set to -1 or set to point at the end of the current
319 * node. These cases must be addressed.
320 */
321 node = cursor->node->ondisk;
322 if (node == NULL)
323 return(ENOENT);
324 if (cursor->index != -1 &&
325 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
326 --cursor->index;
327 }
328 if (cursor->index == cursor->node->ondisk->count)
329 --cursor->index;
330
331 /*
332 * Loop until an element is found or we are done.
333 */
334 for (;;) {
335 /*
336 * We iterate up the tree and then index over one element
337 * while we are at the last element in the current node.
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338 */
339 if (cursor->index == -1) {
340 error = hammer_cursor_up(cursor);
341 if (error) {
342 cursor->index = 0; /* sanity */
343 break;
344 }
345 /* reload stale pointer */
346 node = cursor->node->ondisk;
347 KKASSERT(cursor->index != node->count);
348 --cursor->index;
349 continue;
350 }
351
352 /*
353 * Check internal or leaf element. Determine if the record
354 * at the cursor has gone beyond the end of our range.
355 *
47197d71 356 * We recurse down through internal nodes.
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357 */
358 KKASSERT(cursor->index != node->count);
359 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
360 elm = &node->elms[cursor->index];
361 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
362 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
363 if (hammer_debug_btree) {
2f85fa4d 364 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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365 cursor->node->node_offset,
366 cursor->index,
367 elm[0].internal.base.obj_id,
368 elm[0].internal.base.rec_type,
369 elm[0].internal.base.key,
2f85fa4d 370 elm[0].internal.base.localization,
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371 r
372 );
2f85fa4d 373 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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374 cursor->node->node_offset,
375 cursor->index + 1,
376 elm[1].internal.base.obj_id,
377 elm[1].internal.base.rec_type,
378 elm[1].internal.base.key,
2f85fa4d 379 elm[1].internal.base.localization,
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380 s
381 );
382 }
383
384 if (s >= 0) {
385 error = ENOENT;
386 break;
387 }
388 KKASSERT(r >= 0);
389
390 /*
f36a9737 391 * Better not be zero
32c90105 392 */
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393 KKASSERT(elm->internal.subtree_offset != 0);
394
395 error = hammer_cursor_down(cursor);
396 if (error)
397 break;
398 KKASSERT(cursor->index == 0);
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399 /* reload stale pointer */
400 node = cursor->node->ondisk;
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401
402 /* this can assign -1 if the leaf was empty */
403 cursor->index = node->count - 1;
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404 continue;
405 } else {
406 elm = &node->elms[cursor->index];
407 s = hammer_btree_cmp(&cursor->key_beg, &elm->base);
408 if (hammer_debug_btree) {
2f85fa4d 409 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
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410 cursor->node->node_offset,
411 cursor->index,
412 (elm[0].leaf.base.btype ?
413 elm[0].leaf.base.btype : '?'),
414 elm[0].leaf.base.obj_id,
415 elm[0].leaf.base.rec_type,
416 elm[0].leaf.base.key,
2f85fa4d 417 elm[0].leaf.base.localization,
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418 s
419 );
420 }
421 if (s > 0) {
422 error = ENOENT;
423 break;
424 }
425
426 switch(elm->leaf.base.btype) {
427 case HAMMER_BTREE_TYPE_RECORD:
428 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
429 hammer_btree_chkts(cursor->asof, &elm->base)) {
430 --cursor->index;
431 continue;
432 }
433 break;
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434 default:
435 error = EINVAL;
436 break;
437 }
438 if (error)
439 break;
440 }
441 /*
442 * node pointer invalid after loop
443 */
444
445 /*
446 * Return entry
447 */
448 if (hammer_debug_btree) {
449 int i = cursor->index;
450 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 451 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
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452 cursor->node, i,
453 elm->internal.base.obj_id,
454 elm->internal.base.rec_type,
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455 elm->internal.base.key,
456 elm->internal.base.localization
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457 );
458 }
459 return(0);
460 }
461 return(error);
462}
463
427e5fc6 464/*
8cd0a023 465 * Lookup cursor->key_beg. 0 is returned on success, ENOENT if the entry
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466 * could not be found, EDEADLK if inserting and a retry is needed, and a
467 * fatal error otherwise. When retrying, the caller must terminate the
eaeff70d 468 * cursor and reinitialize it. EDEADLK cannot be returned if not inserting.
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469 *
470 * The cursor is suitably positioned for a deletion on success, and suitably
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471 * positioned for an insertion on ENOENT if HAMMER_CURSOR_INSERT was
472 * specified.
427e5fc6 473 *
47197d71 474 * The cursor may begin anywhere, the search will traverse the tree in
8cd0a023 475 * either direction to locate the requested element.
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476 *
477 * Most of the logic implementing historical searches is handled here. We
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478 * do an initial lookup with create_tid set to the asof TID. Due to the
479 * way records are laid out, a backwards iteration may be required if
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480 * ENOENT is returned to locate the historical record. Here's the
481 * problem:
482 *
9582c7da 483 * create_tid: 10 15 20
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484 * LEAF1 LEAF2
485 * records: (11) (18)
486 *
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487 * Lets say we want to do a lookup AS-OF timestamp 17. We will traverse
488 * LEAF2 but the only record in LEAF2 has a create_tid of 18, which is
489 * not visible and thus causes ENOENT to be returned. We really need
490 * to check record 11 in LEAF1. If it also fails then the search fails
491 * (e.g. it might represent the range 11-16 and thus still not match our
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492 * AS-OF timestamp of 17). Note that LEAF1 could be empty, requiring
493 * further iterations.
b33e2cc0 494 *
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495 * If this case occurs btree_search() will set HAMMER_CURSOR_CREATE_CHECK
496 * and the cursor->create_check TID if an iteration might be needed.
497 * In the above example create_check would be set to 14.
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498 */
499int
8cd0a023 500hammer_btree_lookup(hammer_cursor_t cursor)
427e5fc6 501{
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502 int error;
503
cb51be26 504 ++hammer_stats_btree_lookups;
d5530d22 505 if (cursor->flags & HAMMER_CURSOR_ASOF) {
eaeff70d 506 KKASSERT((cursor->flags & HAMMER_CURSOR_INSERT) == 0);
9582c7da 507 cursor->key_beg.create_tid = cursor->asof;
eaeff70d 508 for (;;) {
9582c7da 509 cursor->flags &= ~HAMMER_CURSOR_CREATE_CHECK;
d5530d22 510 error = btree_search(cursor, 0);
b33e2cc0 511 if (error != ENOENT ||
9582c7da 512 (cursor->flags & HAMMER_CURSOR_CREATE_CHECK) == 0) {
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513 /*
514 * Stop if no error.
515 * Stop if error other then ENOENT.
516 * Stop if ENOENT and not special case.
517 */
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518 break;
519 }
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520 if (hammer_debug_btree) {
521 kprintf("CREATE_CHECK %016llx\n",
522 cursor->create_check);
523 }
9582c7da 524 cursor->key_beg.create_tid = cursor->create_check;
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525 /* loop */
526 }
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527 } else {
528 error = btree_search(cursor, 0);
529 }
bf3b416b 530 if (error == 0)
8cd0a023 531 error = hammer_btree_extract(cursor, cursor->flags);
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532 return(error);
533}
534
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535/*
536 * Execute the logic required to start an iteration. The first record
537 * located within the specified range is returned and iteration control
538 * flags are adjusted for successive hammer_btree_iterate() calls.
539 */
540int
541hammer_btree_first(hammer_cursor_t cursor)
542{
543 int error;
544
545 error = hammer_btree_lookup(cursor);
546 if (error == ENOENT) {
547 cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
548 error = hammer_btree_iterate(cursor);
549 }
550 cursor->flags |= HAMMER_CURSOR_ATEDISK;
551 return(error);
552}
553
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554/*
555 * Similarly but for an iteration in the reverse direction.
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556 *
557 * Set ATEDISK when iterating backwards to skip the current entry,
558 * which after an ENOENT lookup will be pointing beyond our end point.
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559 */
560int
561hammer_btree_last(hammer_cursor_t cursor)
562{
563 struct hammer_base_elm save;
564 int error;
565
566 save = cursor->key_beg;
567 cursor->key_beg = cursor->key_end;
568 error = hammer_btree_lookup(cursor);
569 cursor->key_beg = save;
570 if (error == ENOENT ||
571 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
814387f6 572 cursor->flags |= HAMMER_CURSOR_ATEDISK;
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573 error = hammer_btree_iterate_reverse(cursor);
574 }
575 cursor->flags |= HAMMER_CURSOR_ATEDISK;
576 return(error);
577}
578
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579/*
580 * Extract the record and/or data associated with the cursor's current
581 * position. Any prior record or data stored in the cursor is replaced.
582 * The cursor must be positioned at a leaf node.
583 *
47197d71 584 * NOTE: All extractions occur at the leaf of the B-Tree.
8cd0a023 585 */
66325755 586int
8cd0a023 587hammer_btree_extract(hammer_cursor_t cursor, int flags)
66325755 588{
47197d71 589 hammer_mount_t hmp;
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MD
590 hammer_node_ondisk_t node;
591 hammer_btree_elm_t elm;
47197d71 592 hammer_off_t data_off;
19619882 593 int32_t data_len;
427e5fc6 594 int error;
427e5fc6 595
8cd0a023 596 /*
427e5fc6
MD
597 * The case where the data reference resolves to the same buffer
598 * as the record reference must be handled.
599 */
8cd0a023 600 node = cursor->node->ondisk;
8cd0a023 601 elm = &node->elms[cursor->index];
40043e7f
MD
602 cursor->data = NULL;
603 hmp = cursor->node->hmp;
66325755 604
d26d0ae9 605 /*
fe7678ee 606 * There is nothing to extract for an internal element.
d26d0ae9 607 */
fe7678ee
MD
608 if (node->type == HAMMER_BTREE_TYPE_INTERNAL)
609 return(EINVAL);
610
47197d71
MD
611 /*
612 * Only record types have data.
613 */
fe7678ee 614 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
11ad5ade 615 cursor->leaf = &elm->leaf;
4a2796f3
MD
616
617 if ((flags & HAMMER_CURSOR_GET_DATA) == 0)
618 return(0);
47197d71 619 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
4a2796f3 620 return(0);
47197d71 621 data_off = elm->leaf.data_offset;
19619882 622 data_len = elm->leaf.data_len;
47197d71 623 if (data_off == 0)
4a2796f3 624 return(0);
d26d0ae9 625
4a2796f3
MD
626 /*
627 * Load the data
628 */
629 KKASSERT(data_len >= 0 && data_len <= HAMMER_XBUFSIZE);
630 cursor->data = hammer_bread_ext(hmp, data_off, data_len,
631 &error, &cursor->data_buffer);
632 if (data_len &&
633 crc32(cursor->data, data_len) != elm->leaf.data_crc) {
634 Debugger("CRC FAILED: DATA");
427e5fc6
MD
635 }
636 return(error);
637}
638
639
640/*
8cd0a023
MD
641 * Insert a leaf element into the B-Tree at the current cursor position.
642 * The cursor is positioned such that the element at and beyond the cursor
643 * are shifted to make room for the new record.
644 *
a89aec1b 645 * The caller must call hammer_btree_lookup() with the HAMMER_CURSOR_INSERT
8cd0a023
MD
646 * flag set and that call must return ENOENT before this function can be
647 * called.
648 *
d36ec43b 649 * The caller may depend on the cursor's exclusive lock after return to
1f07f686 650 * interlock frontend visibility (see HAMMER_RECF_CONVERT_DELETE).
d36ec43b 651 *
8cd0a023 652 * ENOSPC is returned if there is no room to insert a new record.
427e5fc6
MD
653 */
654int
11ad5ade 655hammer_btree_insert(hammer_cursor_t cursor, hammer_btree_leaf_elm_t elm)
427e5fc6 656{
8cd0a023 657 hammer_node_ondisk_t node;
427e5fc6 658 int i;
6a37e7e4
MD
659 int error;
660
7bc5b8c2 661 if ((error = hammer_cursor_upgrade_node(cursor)) != 0)
6a37e7e4 662 return(error);
cb51be26 663 ++hammer_stats_btree_inserts;
427e5fc6 664
427e5fc6
MD
665 /*
666 * Insert the element at the leaf node and update the count in the
667 * parent. It is possible for parent to be NULL, indicating that
47197d71
MD
668 * the filesystem's ROOT B-Tree node is a leaf itself, which is
669 * possible. The root inode can never be deleted so the leaf should
670 * never be empty.
427e5fc6
MD
671 *
672 * Remember that the right-hand boundary is not included in the
673 * count.
674 */
36f82b23 675 hammer_modify_node_all(cursor->trans, cursor->node);
8cd0a023 676 node = cursor->node->ondisk;
427e5fc6 677 i = cursor->index;
fe7678ee 678 KKASSERT(elm->base.btype != 0);
8cd0a023
MD
679 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
680 KKASSERT(node->count < HAMMER_BTREE_LEAF_ELMS);
681 if (i != node->count) {
682 bcopy(&node->elms[i], &node->elms[i+1],
683 (node->count - i) * sizeof(*elm));
684 }
11ad5ade 685 node->elms[i].leaf = *elm;
8cd0a023 686 ++node->count;
10a5d1ba 687 hammer_modify_node_done(cursor->node);
427e5fc6 688
eaeff70d 689 /*
47197d71 690 * Debugging sanity checks.
eaeff70d 691 */
11ad5ade
MD
692 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->base) <= 0);
693 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->base) > 0);
eaeff70d 694 if (i) {
11ad5ade 695 KKASSERT(hammer_btree_cmp(&node->elms[i-1].leaf.base, &elm->base) < 0);
eaeff70d 696 }
b3deaf57 697 if (i != node->count - 1)
11ad5ade 698 KKASSERT(hammer_btree_cmp(&node->elms[i+1].leaf.base, &elm->base) > 0);
b3deaf57 699
427e5fc6
MD
700 return(0);
701}
702
703/*
fe7678ee 704 * Delete a record from the B-Tree at the current cursor position.
8cd0a023
MD
705 * The cursor is positioned such that the current element is the one
706 * to be deleted.
707 *
195c19a1
MD
708 * On return the cursor will be positioned after the deleted element and
709 * MAY point to an internal node. It will be suitable for the continuation
710 * of an iteration but not for an insertion or deletion.
8cd0a023 711 *
195c19a1 712 * Deletions will attempt to partially rebalance the B-Tree in an upward
f36a9737
MD
713 * direction, but will terminate rather then deadlock. Empty internal nodes
714 * are never allowed by a deletion which deadlocks may end up giving us an
715 * empty leaf. The pruner will clean up and rebalance the tree.
46fe7ae1
MD
716 *
717 * This function can return EDEADLK, requiring the caller to retry the
718 * operation after clearing the deadlock.
427e5fc6
MD
719 */
720int
8cd0a023 721hammer_btree_delete(hammer_cursor_t cursor)
427e5fc6 722{
8cd0a023
MD
723 hammer_node_ondisk_t ondisk;
724 hammer_node_t node;
725 hammer_node_t parent;
8cd0a023 726 int error;
427e5fc6
MD
727 int i;
728
6a37e7e4
MD
729 if ((error = hammer_cursor_upgrade(cursor)) != 0)
730 return(error);
cb51be26 731 ++hammer_stats_btree_deletes;
6a37e7e4 732
427e5fc6 733 /*
8cd0a023 734 * Delete the element from the leaf node.
427e5fc6 735 *
8cd0a023 736 * Remember that leaf nodes do not have boundaries.
427e5fc6 737 */
8cd0a023
MD
738 node = cursor->node;
739 ondisk = node->ondisk;
427e5fc6
MD
740 i = cursor->index;
741
8cd0a023 742 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_LEAF);
fe7678ee 743 KKASSERT(i >= 0 && i < ondisk->count);
36f82b23 744 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
745 if (i + 1 != ondisk->count) {
746 bcopy(&ondisk->elms[i+1], &ondisk->elms[i],
747 (ondisk->count - i - 1) * sizeof(ondisk->elms[0]));
748 }
749 --ondisk->count;
10a5d1ba 750 hammer_modify_node_done(node);
fe7678ee
MD
751
752 /*
753 * Validate local parent
754 */
755 if (ondisk->parent) {
8cd0a023 756 parent = cursor->parent;
fe7678ee
MD
757
758 KKASSERT(parent != NULL);
759 KKASSERT(parent->node_offset == ondisk->parent);
427e5fc6 760 }
427e5fc6 761
8cd0a023 762 /*
fe7678ee 763 * If the leaf becomes empty it must be detached from the parent,
47197d71 764 * potentially recursing through to the filesystem root.
195c19a1
MD
765 *
766 * This may reposition the cursor at one of the parent's of the
767 * current node.
6a37e7e4
MD
768 *
769 * Ignore deadlock errors, that simply means that btree_remove
f36a9737 770 * was unable to recurse and had to leave us with an empty leaf.
8cd0a023 771 */
b3deaf57 772 KKASSERT(cursor->index <= ondisk->count);
8cd0a023 773 if (ondisk->count == 0) {
f36a9737 774 error = btree_remove(cursor);
6a37e7e4
MD
775 if (error == EDEADLK)
776 error = 0;
8cd0a023 777 } else {
8cd0a023
MD
778 error = 0;
779 }
eaeff70d
MD
780 KKASSERT(cursor->parent == NULL ||
781 cursor->parent_index < cursor->parent->ondisk->count);
8cd0a023
MD
782 return(error);
783}
427e5fc6
MD
784
785/*
8cd0a023
MD
786 * PRIMAY B-TREE SEARCH SUPPORT PROCEDURE
787 *
47197d71 788 * Search the filesystem B-Tree for cursor->key_beg, return the matching node.
8cd0a023 789 *
d26d0ae9
MD
790 * The search can begin ANYWHERE in the B-Tree. As a first step the search
791 * iterates up the tree as necessary to properly position itself prior to
792 * actually doing the sarch.
793 *
8cd0a023 794 * INSERTIONS: The search will split full nodes and leaves on its way down
d26d0ae9
MD
795 * and guarentee that the leaf it ends up on is not full. If we run out
796 * of space the search continues to the leaf (to position the cursor for
797 * the spike), but ENOSPC is returned.
427e5fc6 798 *
fbc6e32a
MD
799 * The search is only guarenteed to end up on a leaf if an error code of 0
800 * is returned, or if inserting and an error code of ENOENT is returned.
d26d0ae9 801 * Otherwise it can stop at an internal node. On success a search returns
47197d71 802 * a leaf node.
eaeff70d
MD
803 *
804 * COMPLEXITY WARNING! This is the core B-Tree search code for the entire
805 * filesystem, and it is not simple code. Please note the following facts:
806 *
807 * - Internal node recursions have a boundary on the left AND right. The
9582c7da 808 * right boundary is non-inclusive. The create_tid is a generic part
eaeff70d
MD
809 * of the key for internal nodes.
810 *
47197d71 811 * - Leaf nodes contain terminal elements only now.
eaeff70d
MD
812 *
813 * - Filesystem lookups typically set HAMMER_CURSOR_ASOF, indicating a
b33e2cc0
MD
814 * historical search. ASOF and INSERT are mutually exclusive. When
815 * doing an as-of lookup btree_search() checks for a right-edge boundary
9582c7da
MD
816 * case. If while recursing down the left-edge differs from the key
817 * by ONLY its create_tid, HAMMER_CURSOR_CREATE_CHECK is set along
818 * with cursor->create_check. This is used by btree_lookup() to iterate.
819 * The iteration backwards because as-of searches can wind up going
b33e2cc0 820 * down the wrong branch of the B-Tree.
427e5fc6 821 */
8cd0a023 822static
427e5fc6 823int
8cd0a023 824btree_search(hammer_cursor_t cursor, int flags)
427e5fc6 825{
8cd0a023 826 hammer_node_ondisk_t node;
61aeeb33 827 hammer_btree_elm_t elm;
8cd0a023 828 int error;
d26d0ae9 829 int enospc = 0;
8cd0a023
MD
830 int i;
831 int r;
b33e2cc0 832 int s;
8cd0a023
MD
833
834 flags |= cursor->flags;
cb51be26 835 ++hammer_stats_btree_searches;
8cd0a023 836
b3deaf57 837 if (hammer_debug_btree) {
2f85fa4d 838 kprintf("SEARCH %016llx[%d] %016llx %02x key=%016llx cre=%016llx lo=%02x (td = %p)\n",
eaeff70d
MD
839 cursor->node->node_offset,
840 cursor->index,
b3deaf57
MD
841 cursor->key_beg.obj_id,
842 cursor->key_beg.rec_type,
d113fda1 843 cursor->key_beg.key,
a84a197d 844 cursor->key_beg.create_tid,
2f85fa4d 845 cursor->key_beg.localization,
a84a197d 846 curthread
b3deaf57 847 );
a84a197d
MD
848 if (cursor->parent)
849 kprintf("SEARCHP %016llx[%d] (%016llx/%016llx %016llx/%016llx) (%p/%p %p/%p)\n",
850 cursor->parent->node_offset, cursor->parent_index,
851 cursor->left_bound->obj_id,
852 cursor->parent->ondisk->elms[cursor->parent_index].internal.base.obj_id,
853 cursor->right_bound->obj_id,
854 cursor->parent->ondisk->elms[cursor->parent_index+1].internal.base.obj_id,
855 cursor->left_bound,
856 &cursor->parent->ondisk->elms[cursor->parent_index],
857 cursor->right_bound,
858 &cursor->parent->ondisk->elms[cursor->parent_index+1]
859 );
b3deaf57
MD
860 }
861
8cd0a023
MD
862 /*
863 * Move our cursor up the tree until we find a node whos range covers
47197d71 864 * the key we are trying to locate.
8cd0a023
MD
865 *
866 * The left bound is inclusive, the right bound is non-inclusive.
47197d71 867 * It is ok to cursor up too far.
8cd0a023 868 */
b33e2cc0
MD
869 for (;;) {
870 r = hammer_btree_cmp(&cursor->key_beg, cursor->left_bound);
871 s = hammer_btree_cmp(&cursor->key_beg, cursor->right_bound);
872 if (r >= 0 && s < 0)
873 break;
9944ae54 874 KKASSERT(cursor->parent);
cb51be26 875 ++hammer_stats_btree_iterations;
6a37e7e4 876 error = hammer_cursor_up(cursor);
8cd0a023
MD
877 if (error)
878 goto done;
427e5fc6 879 }
427e5fc6 880
b33e2cc0
MD
881 /*
882 * The delete-checks below are based on node, not parent. Set the
883 * initial delete-check based on the parent.
884 */
9582c7da
MD
885 if (r == 1) {
886 KKASSERT(cursor->left_bound->create_tid != 1);
887 cursor->create_check = cursor->left_bound->create_tid - 1;
888 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0
MD
889 }
890
8cd0a023 891 /*
47197d71 892 * We better have ended up with a node somewhere.
8cd0a023 893 */
47197d71 894 KKASSERT(cursor->node != NULL);
8cd0a023
MD
895
896 /*
897 * If we are inserting we can't start at a full node if the parent
898 * is also full (because there is no way to split the node),
b33e2cc0 899 * continue running up the tree until the requirement is satisfied
47197d71 900 * or we hit the root of the filesystem.
9582c7da
MD
901 *
902 * (If inserting we aren't doing an as-of search so we don't have
903 * to worry about create_check).
8cd0a023 904 */
61aeeb33 905 while ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
eaeff70d
MD
906 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
907 if (btree_node_is_full(cursor->node->ondisk) == 0)
908 break;
909 } else {
47197d71 910 if (btree_node_is_full(cursor->node->ondisk) ==0)
eaeff70d
MD
911 break;
912 }
b33e2cc0
MD
913 if (cursor->node->ondisk->parent == 0 ||
914 cursor->parent->ondisk->count != HAMMER_BTREE_INT_ELMS) {
8cd0a023 915 break;
b33e2cc0 916 }
cb51be26 917 ++hammer_stats_btree_iterations;
6a37e7e4 918 error = hammer_cursor_up(cursor);
47197d71 919 /* node may have become stale */
8cd0a023
MD
920 if (error)
921 goto done;
427e5fc6 922 }
427e5fc6 923
8cd0a023
MD
924 /*
925 * Push down through internal nodes to locate the requested key.
926 */
8cd0a023
MD
927 node = cursor->node->ondisk;
928 while (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
8cd0a023
MD
929 /*
930 * Scan the node to find the subtree index to push down into.
fbc6e32a 931 * We go one-past, then back-up.
d113fda1 932 *
fe7678ee
MD
933 * We must proactively remove deleted elements which may
934 * have been left over from a deadlocked btree_remove().
935 *
eaeff70d 936 * The left and right boundaries are included in the loop
d5530d22 937 * in order to detect edge cases.
9944ae54 938 *
9582c7da 939 * If the separator only differs by create_tid (r == 1)
eaeff70d
MD
940 * and we are doing an as-of search, we may end up going
941 * down a branch to the left of the one containing the
942 * desired key. This requires numerous special cases.
8cd0a023 943 */
47637bff 944 ++hammer_stats_btree_iterations;
46fe7ae1 945 if (hammer_debug_btree) {
47197d71 946 kprintf("SEARCH-I %016llx count=%d\n",
46fe7ae1
MD
947 cursor->node->node_offset,
948 node->count);
949 }
af209b0f
MD
950
951 /*
952 * Try to shortcut the search before dropping into the
953 * linear loop. Locate the first node where r <= 1.
954 */
955 i = hammer_btree_search_node(&cursor->key_beg, node);
956 while (i <= node->count) {
cb51be26 957 ++hammer_stats_btree_elements;
61aeeb33
MD
958 elm = &node->elms[i];
959 r = hammer_btree_cmp(&cursor->key_beg, &elm->base);
b33e2cc0
MD
960 if (hammer_debug_btree > 2) {
961 kprintf(" IELM %p %d r=%d\n",
962 &node->elms[i], i, r);
963 }
9582c7da 964 if (r < 0)
8cd0a023 965 break;
9582c7da
MD
966 if (r == 1) {
967 KKASSERT(elm->base.create_tid != 1);
968 cursor->create_check = elm->base.create_tid - 1;
969 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0 970 }
af209b0f 971 ++i;
8cd0a023 972 }
eaeff70d 973 if (hammer_debug_btree) {
46fe7ae1
MD
974 kprintf("SEARCH-I preI=%d/%d r=%d\n",
975 i, node->count, r);
eaeff70d 976 }
8cd0a023
MD
977
978 /*
9944ae54
MD
979 * These cases occur when the parent's idea of the boundary
980 * is wider then the child's idea of the boundary, and
981 * require special handling. If not inserting we can
982 * terminate the search early for these cases but the
983 * child's boundaries cannot be unconditionally modified.
8cd0a023 984 */
fbc6e32a 985 if (i == 0) {
9944ae54
MD
986 /*
987 * If i == 0 the search terminated to the LEFT of the
988 * left_boundary but to the RIGHT of the parent's left
989 * boundary.
990 */
fbc6e32a 991 u_int8_t save;
d26d0ae9 992
eaeff70d
MD
993 elm = &node->elms[0];
994
995 /*
996 * If we aren't inserting we can stop here.
997 */
11ad5ade
MD
998 if ((flags & (HAMMER_CURSOR_INSERT |
999 HAMMER_CURSOR_PRUNING)) == 0) {
fbc6e32a
MD
1000 cursor->index = 0;
1001 return(ENOENT);
1002 }
9944ae54 1003
d5530d22
MD
1004 /*
1005 * Correct a left-hand boundary mismatch.
6a37e7e4 1006 *
f36a9737
MD
1007 * We can only do this if we can upgrade the lock,
1008 * and synchronized as a background cursor (i.e.
1009 * inserting or pruning).
10a5d1ba
MD
1010 *
1011 * WARNING: We can only do this if inserting, i.e.
1012 * we are running on the backend.
d5530d22 1013 */
eaeff70d
MD
1014 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1015 return(error);
10a5d1ba 1016 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
c9b9e29d
MD
1017 hammer_modify_node_field(cursor->trans, cursor->node,
1018 elms[0]);
fe7678ee 1019 save = node->elms[0].base.btype;
d5530d22 1020 node->elms[0].base = *cursor->left_bound;
fe7678ee 1021 node->elms[0].base.btype = save;
10a5d1ba 1022 hammer_modify_node_done(cursor->node);
9944ae54 1023 } else if (i == node->count + 1) {
d26d0ae9 1024 /*
9944ae54
MD
1025 * If i == node->count + 1 the search terminated to
1026 * the RIGHT of the right boundary but to the LEFT
eaeff70d
MD
1027 * of the parent's right boundary. If we aren't
1028 * inserting we can stop here.
d113fda1 1029 *
9944ae54
MD
1030 * Note that the last element in this case is
1031 * elms[i-2] prior to adjustments to 'i'.
d26d0ae9 1032 */
9944ae54 1033 --i;
11ad5ade
MD
1034 if ((flags & (HAMMER_CURSOR_INSERT |
1035 HAMMER_CURSOR_PRUNING)) == 0) {
9944ae54 1036 cursor->index = i;
eaeff70d 1037 return (ENOENT);
d26d0ae9
MD
1038 }
1039
d5530d22
MD
1040 /*
1041 * Correct a right-hand boundary mismatch.
1042 * (actual push-down record is i-2 prior to
1043 * adjustments to i).
6a37e7e4 1044 *
f36a9737
MD
1045 * We can only do this if we can upgrade the lock,
1046 * and synchronized as a background cursor (i.e.
1047 * inserting or pruning).
10a5d1ba
MD
1048 *
1049 * WARNING: We can only do this if inserting, i.e.
1050 * we are running on the backend.
d5530d22 1051 */
eaeff70d
MD
1052 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1053 return(error);
9944ae54 1054 elm = &node->elms[i];
10a5d1ba 1055 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
36f82b23
MD
1056 hammer_modify_node(cursor->trans, cursor->node,
1057 &elm->base, sizeof(elm->base));
d5530d22 1058 elm->base = *cursor->right_bound;
10a5d1ba 1059 hammer_modify_node_done(cursor->node);
d5530d22 1060 --i;
fbc6e32a
MD
1061 } else {
1062 /*
9944ae54
MD
1063 * The push-down index is now i - 1. If we had
1064 * terminated on the right boundary this will point
1065 * us at the last element.
fbc6e32a
MD
1066 */
1067 --i;
1068 }
8cd0a023 1069 cursor->index = i;
6a37e7e4 1070 elm = &node->elms[i];
8cd0a023 1071
b3deaf57 1072 if (hammer_debug_btree) {
47197d71 1073 kprintf("RESULT-I %016llx[%d] %016llx %02x "
2f85fa4d 1074 "key=%016llx cre=%016llx lo=%02x\n",
eaeff70d
MD
1075 cursor->node->node_offset,
1076 i,
b3deaf57
MD
1077 elm->internal.base.obj_id,
1078 elm->internal.base.rec_type,
d113fda1 1079 elm->internal.base.key,
2f85fa4d
MD
1080 elm->internal.base.create_tid,
1081 elm->internal.base.localization
b3deaf57
MD
1082 );
1083 }
1084
6a37e7e4 1085 /*
f36a9737 1086 * We better have a valid subtree offset.
6a37e7e4 1087 */
f36a9737 1088 KKASSERT(elm->internal.subtree_offset != 0);
6a37e7e4 1089
8cd0a023
MD
1090 /*
1091 * Handle insertion and deletion requirements.
1092 *
1093 * If inserting split full nodes. The split code will
1094 * adjust cursor->node and cursor->index if the current
1095 * index winds up in the new node.
61aeeb33 1096 *
9944ae54
MD
1097 * If inserting and a left or right edge case was detected,
1098 * we cannot correct the left or right boundary and must
1099 * prepend and append an empty leaf node in order to make
1100 * the boundary correction.
1101 *
61aeeb33
MD
1102 * If we run out of space we set enospc and continue on
1103 * to a leaf to provide the spike code with a good point
47197d71 1104 * of entry.
8cd0a023 1105 */
61aeeb33 1106 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
fe7678ee 1107 if (btree_node_is_full(node)) {
8cd0a023 1108 error = btree_split_internal(cursor);
d26d0ae9
MD
1109 if (error) {
1110 if (error != ENOSPC)
1111 goto done;
1112 enospc = 1;
d26d0ae9 1113 }
8cd0a023
MD
1114 /*
1115 * reload stale pointers
1116 */
1117 i = cursor->index;
1118 node = cursor->node->ondisk;
1119 }
d26d0ae9 1120 }
427e5fc6
MD
1121
1122 /*
8cd0a023 1123 * Push down (push into new node, existing node becomes
d26d0ae9 1124 * the parent) and continue the search.
427e5fc6 1125 */
8cd0a023 1126 error = hammer_cursor_down(cursor);
47197d71 1127 /* node may have become stale */
8cd0a023
MD
1128 if (error)
1129 goto done;
1130 node = cursor->node->ondisk;
427e5fc6 1131 }
427e5fc6 1132
8cd0a023
MD
1133 /*
1134 * We are at a leaf, do a linear search of the key array.
d26d0ae9
MD
1135 *
1136 * On success the index is set to the matching element and 0
1137 * is returned.
1138 *
1139 * On failure the index is set to the insertion point and ENOENT
1140 * is returned.
8cd0a023
MD
1141 *
1142 * Boundaries are not stored in leaf nodes, so the index can wind
1143 * up to the left of element 0 (index == 0) or past the end of
f36a9737
MD
1144 * the array (index == node->count). It is also possible that the
1145 * leaf might be empty.
8cd0a023 1146 */
47637bff 1147 ++hammer_stats_btree_iterations;
fe7678ee 1148 KKASSERT (node->type == HAMMER_BTREE_TYPE_LEAF);
8cd0a023 1149 KKASSERT(node->count <= HAMMER_BTREE_LEAF_ELMS);
46fe7ae1 1150 if (hammer_debug_btree) {
47197d71 1151 kprintf("SEARCH-L %016llx count=%d\n",
46fe7ae1
MD
1152 cursor->node->node_offset,
1153 node->count);
1154 }
8cd0a023 1155
af209b0f
MD
1156 /*
1157 * Try to shortcut the search before dropping into the
1158 * linear loop. Locate the first node where r <= 1.
1159 */
1160 i = hammer_btree_search_node(&cursor->key_beg, node);
1161 while (i < node->count) {
cb51be26 1162 ++hammer_stats_btree_elements;
fe7678ee
MD
1163 elm = &node->elms[i];
1164
1165 r = hammer_btree_cmp(&cursor->key_beg, &elm->leaf.base);
427e5fc6 1166
d5530d22
MD
1167 if (hammer_debug_btree > 1)
1168 kprintf(" ELM %p %d r=%d\n", &node->elms[i], i, r);
1169
427e5fc6 1170 /*
fe7678ee 1171 * We are at a record element. Stop if we've flipped past
9582c7da
MD
1172 * key_beg, not counting the create_tid test. Allow the
1173 * r == 1 case (key_beg > element but differs only by its
1174 * create_tid) to fall through to the AS-OF check.
427e5fc6 1175 */
fe7678ee
MD
1176 KKASSERT (elm->leaf.base.btype == HAMMER_BTREE_TYPE_RECORD);
1177
9582c7da 1178 if (r < 0)
d5530d22 1179 goto failed;
af209b0f
MD
1180 if (r > 1) {
1181 ++i;
d5530d22 1182 continue;
af209b0f 1183 }
427e5fc6 1184
66325755 1185 /*
9582c7da 1186 * Check our as-of timestamp against the element.
66325755 1187 */
eaeff70d 1188 if (flags & HAMMER_CURSOR_ASOF) {
fe7678ee 1189 if (hammer_btree_chkts(cursor->asof,
d113fda1 1190 &node->elms[i].base) != 0) {
af209b0f 1191 ++i;
d113fda1
MD
1192 continue;
1193 }
eaeff70d
MD
1194 /* success */
1195 } else {
af209b0f
MD
1196 if (r > 0) { /* can only be +1 */
1197 ++i;
9582c7da 1198 continue;
af209b0f 1199 }
eaeff70d 1200 /* success */
66325755 1201 }
d5530d22
MD
1202 cursor->index = i;
1203 error = 0;
eaeff70d 1204 if (hammer_debug_btree) {
47197d71
MD
1205 kprintf("RESULT-L %016llx[%d] (SUCCESS)\n",
1206 cursor->node->node_offset, i);
eaeff70d 1207 }
d5530d22
MD
1208 goto done;
1209 }
1210
1211 /*
eaeff70d 1212 * The search of the leaf node failed. i is the insertion point.
d5530d22 1213 */
d5530d22 1214failed:
b3deaf57 1215 if (hammer_debug_btree) {
47197d71
MD
1216 kprintf("RESULT-L %016llx[%d] (FAILED)\n",
1217 cursor->node->node_offset, i);
b3deaf57
MD
1218 }
1219
8cd0a023
MD
1220 /*
1221 * No exact match was found, i is now at the insertion point.
1222 *
1223 * If inserting split a full leaf before returning. This
1224 * may have the side effect of adjusting cursor->node and
1225 * cursor->index.
1226 */
1227 cursor->index = i;
eaeff70d 1228 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0 &&
47197d71 1229 btree_node_is_full(node)) {
8cd0a023 1230 error = btree_split_leaf(cursor);
d26d0ae9
MD
1231 if (error) {
1232 if (error != ENOSPC)
1233 goto done;
1234 enospc = 1;
d26d0ae9
MD
1235 }
1236 /*
1237 * reload stale pointers
1238 */
8cd0a023
MD
1239 /* NOT USED
1240 i = cursor->index;
1241 node = &cursor->node->internal;
1242 */
8cd0a023 1243 }
d26d0ae9
MD
1244
1245 /*
1246 * We reached a leaf but did not find the key we were looking for.
1247 * If this is an insert we will be properly positioned for an insert
1248 * (ENOENT) or spike (ENOSPC) operation.
1249 */
1250 error = enospc ? ENOSPC : ENOENT;
8cd0a023 1251done:
427e5fc6
MD
1252 return(error);
1253}
1254
af209b0f
MD
1255/*
1256 * Heuristical search for the first element whos comparison is <= 1. May
1257 * return an index whos compare result is > 1 but may only return an index
1258 * whos compare result is <= 1 if it is the first element with that result.
1259 */
bcac4bbb 1260int
af209b0f
MD
1261hammer_btree_search_node(hammer_base_elm_t elm, hammer_node_ondisk_t node)
1262{
1263 int b;
1264 int s;
1265 int i;
1266 int r;
1267
1268 /*
1269 * Don't bother if the node does not have very many elements
1270 */
1271 b = 0;
1272 s = node->count;
1273 while (s - b > 4) {
1274 i = b + (s - b) / 2;
cb51be26 1275 ++hammer_stats_btree_elements;
af209b0f
MD
1276 r = hammer_btree_cmp(elm, &node->elms[i].leaf.base);
1277 if (r <= 1) {
1278 s = i;
1279 } else {
1280 b = i;
1281 }
1282 }
1283 return(b);
1284}
1285
8cd0a023 1286
427e5fc6 1287/************************************************************************
8cd0a023 1288 * SPLITTING AND MERGING *
427e5fc6
MD
1289 ************************************************************************
1290 *
1291 * These routines do all the dirty work required to split and merge nodes.
1292 */
1293
1294/*
8cd0a023 1295 * Split an internal node into two nodes and move the separator at the split
fe7678ee 1296 * point to the parent.
427e5fc6 1297 *
8cd0a023
MD
1298 * (cursor->node, cursor->index) indicates the element the caller intends
1299 * to push into. We will adjust node and index if that element winds
427e5fc6 1300 * up in the split node.
8cd0a023 1301 *
47197d71
MD
1302 * If we are at the root of the filesystem a new root must be created with
1303 * two elements, one pointing to the original root and one pointing to the
8cd0a023 1304 * newly allocated split node.
427e5fc6
MD
1305 */
1306static
1307int
8cd0a023 1308btree_split_internal(hammer_cursor_t cursor)
427e5fc6 1309{
8cd0a023
MD
1310 hammer_node_ondisk_t ondisk;
1311 hammer_node_t node;
1312 hammer_node_t parent;
1313 hammer_node_t new_node;
1314 hammer_btree_elm_t elm;
1315 hammer_btree_elm_t parent_elm;
b33e2cc0 1316 hammer_node_locklist_t locklist = NULL;
36f82b23 1317 hammer_mount_t hmp = cursor->trans->hmp;
427e5fc6
MD
1318 int parent_index;
1319 int made_root;
1320 int split;
1321 int error;
7f7c1f84 1322 int i;
8cd0a023 1323 const int esize = sizeof(*elm);
427e5fc6 1324
47197d71
MD
1325 error = hammer_btree_lock_children(cursor, &locklist);
1326 if (error)
1327 goto done;
7bc5b8c2
MD
1328 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1329 goto done;
cb51be26 1330 ++hammer_stats_btree_splits;
6a37e7e4 1331
427e5fc6
MD
1332 /*
1333 * We are splitting but elms[split] will be promoted to the parent,
1334 * leaving the right hand node with one less element. If the
1335 * insertion point will be on the left-hand side adjust the split
1336 * point to give the right hand side one additional node.
1337 */
8cd0a023
MD
1338 node = cursor->node;
1339 ondisk = node->ondisk;
1340 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1341 if (cursor->index <= split)
1342 --split;
427e5fc6
MD
1343
1344 /*
47197d71
MD
1345 * If we are at the root of the filesystem, create a new root node
1346 * with 1 element and split normally. Avoid making major
1347 * modifications until we know the whole operation will work.
427e5fc6 1348 */
8cd0a023 1349 if (ondisk->parent == 0) {
36f82b23 1350 parent = hammer_alloc_btree(cursor->trans, &error);
427e5fc6 1351 if (parent == NULL)
6a37e7e4 1352 goto done;
8cd0a023 1353 hammer_lock_ex(&parent->lock);
36f82b23 1354 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1355 ondisk = parent->ondisk;
1356 ondisk->count = 1;
1357 ondisk->parent = 0;
1358 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1359 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1360 ondisk->elms[0].base.btype = node->ondisk->type;
8cd0a023 1361 ondisk->elms[0].internal.subtree_offset = node->node_offset;
47197d71 1362 ondisk->elms[1].base = hmp->root_btree_end;
10a5d1ba 1363 hammer_modify_node_done(parent);
fe7678ee 1364 /* ondisk->elms[1].base.btype - not used */
427e5fc6 1365 made_root = 1;
8cd0a023 1366 parent_index = 0; /* index of current node in parent */
427e5fc6
MD
1367 } else {
1368 made_root = 0;
8cd0a023
MD
1369 parent = cursor->parent;
1370 parent_index = cursor->parent_index;
427e5fc6 1371 }
427e5fc6
MD
1372
1373 /*
1374 * Split node into new_node at the split point.
1375 *
1376 * B O O O P N N B <-- P = node->elms[split]
1377 * 0 1 2 3 4 5 6 <-- subtree indices
1378 *
1379 * x x P x x
1380 * s S S s
1381 * / \
1382 * B O O O B B N N B <--- inner boundary points are 'P'
1383 * 0 1 2 3 4 5 6
1384 *
1385 */
36f82b23 1386 new_node = hammer_alloc_btree(cursor->trans, &error);
427e5fc6 1387 if (new_node == NULL) {
8cd0a023
MD
1388 if (made_root) {
1389 hammer_unlock(&parent->lock);
36f82b23 1390 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1391 hammer_rel_node(parent);
1392 }
6a37e7e4 1393 goto done;
427e5fc6 1394 }
8cd0a023 1395 hammer_lock_ex(&new_node->lock);
427e5fc6
MD
1396
1397 /*
8cd0a023 1398 * Create the new node. P becomes the left-hand boundary in the
427e5fc6
MD
1399 * new node. Copy the right-hand boundary as well.
1400 *
1401 * elm is the new separator.
1402 */
36f82b23
MD
1403 hammer_modify_node_noundo(cursor->trans, new_node);
1404 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
1405 ondisk = node->ondisk;
1406 elm = &ondisk->elms[split];
1407 bcopy(elm, &new_node->ondisk->elms[0],
1408 (ondisk->count - split + 1) * esize);
1409 new_node->ondisk->count = ondisk->count - split;
1410 new_node->ondisk->parent = parent->node_offset;
1411 new_node->ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
1412 KKASSERT(ondisk->type == new_node->ondisk->type);
427e5fc6
MD
1413
1414 /*
fe7678ee
MD
1415 * Cleanup the original node. Elm (P) becomes the new boundary,
1416 * its subtree_offset was moved to the new node. If we had created
427e5fc6
MD
1417 * a new root its parent pointer may have changed.
1418 */
8cd0a023 1419 elm->internal.subtree_offset = 0;
c0ade690 1420 ondisk->count = split;
427e5fc6
MD
1421
1422 /*
1423 * Insert the separator into the parent, fixup the parent's
1424 * reference to the original node, and reference the new node.
1425 * The separator is P.
1426 *
1427 * Remember that base.count does not include the right-hand boundary.
1428 */
36f82b23 1429 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1430 ondisk = parent->ondisk;
d26d0ae9 1431 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1432 parent_elm = &ondisk->elms[parent_index+1];
427e5fc6 1433 bcopy(parent_elm, parent_elm + 1,
8cd0a023
MD
1434 (ondisk->count - parent_index) * esize);
1435 parent_elm->internal.base = elm->base; /* separator P */
fe7678ee 1436 parent_elm->internal.base.btype = new_node->ondisk->type;
8cd0a023 1437 parent_elm->internal.subtree_offset = new_node->node_offset;
76376933 1438 ++ondisk->count;
10a5d1ba 1439 hammer_modify_node_done(parent);
427e5fc6 1440
7f7c1f84
MD
1441 /*
1442 * The children of new_node need their parent pointer set to new_node.
b33e2cc0
MD
1443 * The children have already been locked by
1444 * hammer_btree_lock_children().
7f7c1f84
MD
1445 */
1446 for (i = 0; i < new_node->ondisk->count; ++i) {
1447 elm = &new_node->ondisk->elms[i];
36f82b23 1448 error = btree_set_parent(cursor->trans, new_node, elm);
7f7c1f84
MD
1449 if (error) {
1450 panic("btree_split_internal: btree-fixup problem");
1451 }
1452 }
10a5d1ba 1453 hammer_modify_node_done(new_node);
7f7c1f84 1454
427e5fc6 1455 /*
47197d71 1456 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1457 */
1458 if (made_root) {
47197d71
MD
1459 hammer_volume_t volume;
1460
1461 volume = hammer_get_root_volume(hmp, &error);
1462 KKASSERT(error == 0);
1463
e8599db1
MD
1464 hammer_modify_volume_field(cursor->trans, volume,
1465 vol0_btree_root);
47197d71 1466 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1467 hammer_modify_volume_done(volume);
8cd0a023
MD
1468 node->ondisk->parent = parent->node_offset;
1469 if (cursor->parent) {
1470 hammer_unlock(&cursor->parent->lock);
1471 hammer_rel_node(cursor->parent);
1472 }
1473 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1474 hammer_rel_volume(volume, 0);
427e5fc6 1475 }
10a5d1ba 1476 hammer_modify_node_done(node);
427e5fc6 1477
8cd0a023 1478
427e5fc6
MD
1479 /*
1480 * Ok, now adjust the cursor depending on which element the original
1481 * index was pointing at. If we are >= the split point the push node
1482 * is now in the new node.
1483 *
1484 * NOTE: If we are at the split point itself we cannot stay with the
1485 * original node because the push index will point at the right-hand
1486 * boundary, which is illegal.
8cd0a023
MD
1487 *
1488 * NOTE: The cursor's parent or parent_index must be adjusted for
1489 * the case where a new parent (new root) was created, and the case
1490 * where the cursor is now pointing at the split node.
427e5fc6
MD
1491 */
1492 if (cursor->index >= split) {
8cd0a023 1493 cursor->parent_index = parent_index + 1;
427e5fc6 1494 cursor->index -= split;
8cd0a023
MD
1495 hammer_unlock(&cursor->node->lock);
1496 hammer_rel_node(cursor->node);
1497 cursor->node = new_node; /* locked and ref'd */
1498 } else {
1499 cursor->parent_index = parent_index;
1500 hammer_unlock(&new_node->lock);
1501 hammer_rel_node(new_node);
427e5fc6 1502 }
76376933
MD
1503
1504 /*
1505 * Fixup left and right bounds
1506 */
1507 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1508 cursor->left_bound = &parent_elm[0].internal.base;
1509 cursor->right_bound = &parent_elm[1].internal.base;
b3deaf57
MD
1510 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1511 &cursor->node->ondisk->elms[0].internal.base) <= 0);
1512 KKASSERT(hammer_btree_cmp(cursor->right_bound,
9944ae54 1513 &cursor->node->ondisk->elms[cursor->node->ondisk->count].internal.base) >= 0);
76376933 1514
6a37e7e4 1515done:
b33e2cc0 1516 hammer_btree_unlock_children(&locklist);
6a37e7e4
MD
1517 hammer_cursor_downgrade(cursor);
1518 return (error);
427e5fc6
MD
1519}
1520
1521/*
1522 * Same as the above, but splits a full leaf node.
6a37e7e4
MD
1523 *
1524 * This function
427e5fc6
MD
1525 */
1526static
1527int
8cd0a023 1528btree_split_leaf(hammer_cursor_t cursor)
427e5fc6 1529{
8cd0a023
MD
1530 hammer_node_ondisk_t ondisk;
1531 hammer_node_t parent;
1532 hammer_node_t leaf;
47197d71 1533 hammer_mount_t hmp;
8cd0a023
MD
1534 hammer_node_t new_leaf;
1535 hammer_btree_elm_t elm;
1536 hammer_btree_elm_t parent_elm;
b3deaf57 1537 hammer_base_elm_t mid_boundary;
427e5fc6
MD
1538 int parent_index;
1539 int made_root;
1540 int split;
1541 int error;
8cd0a023 1542 const size_t esize = sizeof(*elm);
427e5fc6 1543
6a37e7e4
MD
1544 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1545 return(error);
cb51be26 1546 ++hammer_stats_btree_splits;
6a37e7e4 1547
36f82b23
MD
1548 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1549 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1550 KKASSERT(hammer_btree_cmp(cursor->right_bound,
1551 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
1552
427e5fc6 1553 /*
8cd0a023
MD
1554 * Calculate the split point. If the insertion point will be on
1555 * the left-hand side adjust the split point to give the right
1556 * hand side one additional node.
fe7678ee
MD
1557 *
1558 * Spikes are made up of two leaf elements which cannot be
1559 * safely split.
427e5fc6 1560 */
8cd0a023
MD
1561 leaf = cursor->node;
1562 ondisk = leaf->ondisk;
1563 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1564 if (cursor->index <= split)
1565 --split;
1566 error = 0;
40043e7f 1567 hmp = leaf->hmp;
427e5fc6 1568
fe7678ee 1569 elm = &ondisk->elms[split];
fe7678ee 1570
36f82b23
MD
1571 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm[-1].leaf.base) <= 0);
1572 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->leaf.base) <= 0);
1573 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->leaf.base) > 0);
1574 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm[1].leaf.base) > 0);
1575
427e5fc6
MD
1576 /*
1577 * If we are at the root of the tree, create a new root node with
1578 * 1 element and split normally. Avoid making major modifications
1579 * until we know the whole operation will work.
1580 */
8cd0a023 1581 if (ondisk->parent == 0) {
36f82b23 1582 parent = hammer_alloc_btree(cursor->trans, &error);
427e5fc6 1583 if (parent == NULL)
6a37e7e4 1584 goto done;
8cd0a023 1585 hammer_lock_ex(&parent->lock);
36f82b23 1586 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1587 ondisk = parent->ondisk;
1588 ondisk->count = 1;
1589 ondisk->parent = 0;
1590 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1591 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1592 ondisk->elms[0].base.btype = leaf->ondisk->type;
8cd0a023 1593 ondisk->elms[0].internal.subtree_offset = leaf->node_offset;
47197d71 1594 ondisk->elms[1].base = hmp->root_btree_end;
fe7678ee 1595 /* ondisk->elms[1].base.btype = not used */
10a5d1ba 1596 hammer_modify_node_done(parent);
427e5fc6 1597 made_root = 1;
8cd0a023 1598 parent_index = 0; /* insertion point in parent */
427e5fc6
MD
1599 } else {
1600 made_root = 0;
8cd0a023
MD
1601 parent = cursor->parent;
1602 parent_index = cursor->parent_index;
427e5fc6 1603 }
427e5fc6
MD
1604
1605 /*
1606 * Split leaf into new_leaf at the split point. Select a separator
1607 * value in-between the two leafs but with a bent towards the right
1608 * leaf since comparisons use an 'elm >= separator' inequality.
1609 *
1610 * L L L L L L L L
1611 *
1612 * x x P x x
1613 * s S S s
1614 * / \
1615 * L L L L L L L L
1616 */
36f82b23 1617 new_leaf = hammer_alloc_btree(cursor->trans, &error);
427e5fc6 1618 if (new_leaf == NULL) {
8cd0a023
MD
1619 if (made_root) {
1620 hammer_unlock(&parent->lock);
36f82b23 1621 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1622 hammer_rel_node(parent);
1623 }
6a37e7e4 1624 goto done;
427e5fc6 1625 }
8cd0a023 1626 hammer_lock_ex(&new_leaf->lock);
427e5fc6
MD
1627
1628 /*
36f82b23
MD
1629 * Create the new node and copy the leaf elements from the split
1630 * point on to the new node.
427e5fc6 1631 */
36f82b23
MD
1632 hammer_modify_node_all(cursor->trans, leaf);
1633 hammer_modify_node_noundo(cursor->trans, new_leaf);
8cd0a023
MD
1634 ondisk = leaf->ondisk;
1635 elm = &ondisk->elms[split];
1636 bcopy(elm, &new_leaf->ondisk->elms[0], (ondisk->count - split) * esize);
1637 new_leaf->ondisk->count = ondisk->count - split;
1638 new_leaf->ondisk->parent = parent->node_offset;
1639 new_leaf->ondisk->type = HAMMER_BTREE_TYPE_LEAF;
1640 KKASSERT(ondisk->type == new_leaf->ondisk->type);
10a5d1ba 1641 hammer_modify_node_done(new_leaf);
427e5fc6
MD
1642
1643 /*
8cd0a023
MD
1644 * Cleanup the original node. Because this is a leaf node and
1645 * leaf nodes do not have a right-hand boundary, there
c0ade690
MD
1646 * aren't any special edge cases to clean up. We just fixup the
1647 * count.
427e5fc6 1648 */
c0ade690 1649 ondisk->count = split;
427e5fc6
MD
1650
1651 /*
1652 * Insert the separator into the parent, fixup the parent's
1653 * reference to the original node, and reference the new node.
1654 * The separator is P.
1655 *
1656 * Remember that base.count does not include the right-hand boundary.
1657 * We are copying parent_index+1 to parent_index+2, not +0 to +1.
1658 */
36f82b23 1659 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1660 ondisk = parent->ondisk;
36f82b23 1661 KKASSERT(split != 0);
d26d0ae9 1662 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1663 parent_elm = &ondisk->elms[parent_index+1];
d26d0ae9
MD
1664 bcopy(parent_elm, parent_elm + 1,
1665 (ondisk->count - parent_index) * esize);
eaeff70d 1666
47197d71 1667 hammer_make_separator(&elm[-1].base, &elm[0].base, &parent_elm->base);
fe7678ee 1668 parent_elm->internal.base.btype = new_leaf->ondisk->type;
8cd0a023 1669 parent_elm->internal.subtree_offset = new_leaf->node_offset;
b3deaf57 1670 mid_boundary = &parent_elm->base;
76376933 1671 ++ondisk->count;
10a5d1ba 1672 hammer_modify_node_done(parent);
427e5fc6 1673
fe7678ee 1674 /*
47197d71 1675 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1676 */
1677 if (made_root) {
47197d71
MD
1678 hammer_volume_t volume;
1679
1680 volume = hammer_get_root_volume(hmp, &error);
1681 KKASSERT(error == 0);
1682
e8599db1
MD
1683 hammer_modify_volume_field(cursor->trans, volume,
1684 vol0_btree_root);
47197d71 1685 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1686 hammer_modify_volume_done(volume);
8cd0a023
MD
1687 leaf->ondisk->parent = parent->node_offset;
1688 if (cursor->parent) {
1689 hammer_unlock(&cursor->parent->lock);
1690 hammer_rel_node(cursor->parent);
1691 }
1692 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1693 hammer_rel_volume(volume, 0);
427e5fc6 1694 }
10a5d1ba 1695 hammer_modify_node_done(leaf);
8cd0a023 1696
427e5fc6
MD
1697 /*
1698 * Ok, now adjust the cursor depending on which element the original
1699 * index was pointing at. If we are >= the split point the push node
1700 * is now in the new node.
1701 *
b3deaf57
MD
1702 * NOTE: If we are at the split point itself we need to select the
1703 * old or new node based on where key_beg's insertion point will be.
1704 * If we pick the wrong side the inserted element will wind up in
1705 * the wrong leaf node and outside that node's bounds.
427e5fc6 1706 */
b3deaf57
MD
1707 if (cursor->index > split ||
1708 (cursor->index == split &&
1709 hammer_btree_cmp(&cursor->key_beg, mid_boundary) >= 0)) {
8cd0a023 1710 cursor->parent_index = parent_index + 1;
427e5fc6 1711 cursor->index -= split;
8cd0a023
MD
1712 hammer_unlock(&cursor->node->lock);
1713 hammer_rel_node(cursor->node);
1714 cursor->node = new_leaf;
1715 } else {
1716 cursor->parent_index = parent_index;
1717 hammer_unlock(&new_leaf->lock);
1718 hammer_rel_node(new_leaf);
427e5fc6 1719 }
76376933
MD
1720
1721 /*
1722 * Fixup left and right bounds
1723 */
1724 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1725 cursor->left_bound = &parent_elm[0].internal.base;
1726 cursor->right_bound = &parent_elm[1].internal.base;
eaeff70d
MD
1727
1728 /*
47197d71 1729 * Assert that the bounds are correct.
eaeff70d 1730 */
b3deaf57
MD
1731 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1732 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1733 KKASSERT(hammer_btree_cmp(cursor->right_bound,
47197d71 1734 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
36f82b23
MD
1735 KKASSERT(hammer_btree_cmp(cursor->left_bound, &cursor->key_beg) <= 0);
1736 KKASSERT(hammer_btree_cmp(cursor->right_bound, &cursor->key_beg) > 0);
76376933 1737
6a37e7e4
MD
1738done:
1739 hammer_cursor_downgrade(cursor);
1740 return (error);
427e5fc6
MD
1741}
1742
32c90105
MD
1743/*
1744 * Recursively correct the right-hand boundary's create_tid to (tid) as
1745 * long as the rest of the key matches. We have to recurse upward in
1746 * the tree as well as down the left side of each parent's right node.
1747 *
1748 * Return EDEADLK if we were only partially successful, forcing the caller
1749 * to try again. The original cursor is not modified. This routine can
1750 * also fail with EDEADLK if it is forced to throw away a portion of its
1751 * record history.
1752 *
1753 * The caller must pass a downgraded cursor to us (otherwise we can't dup it).
1754 */
1755struct hammer_rhb {
1756 TAILQ_ENTRY(hammer_rhb) entry;
1757 hammer_node_t node;
1758 int index;
1759};
1760
1761TAILQ_HEAD(hammer_rhb_list, hammer_rhb);
1762
1763int
1764hammer_btree_correct_rhb(hammer_cursor_t cursor, hammer_tid_t tid)
1765{
1766 struct hammer_rhb_list rhb_list;
1767 hammer_base_elm_t elm;
1768 hammer_node_t orig_node;
1769 struct hammer_rhb *rhb;
1770 int orig_index;
1771 int error;
1772
1773 TAILQ_INIT(&rhb_list);
1774
1775 /*
1776 * Save our position so we can restore it on return. This also
1777 * gives us a stable 'elm'.
1778 */
1779 orig_node = cursor->node;
1780 hammer_ref_node(orig_node);
1781 hammer_lock_sh(&orig_node->lock);
1782 orig_index = cursor->index;
1783 elm = &orig_node->ondisk->elms[orig_index].base;
1784
1785 /*
1786 * Now build a list of parents going up, allocating a rhb
1787 * structure for each one.
1788 */
1789 while (cursor->parent) {
1790 /*
1791 * Stop if we no longer have any right-bounds to fix up
1792 */
1793 if (elm->obj_id != cursor->right_bound->obj_id ||
1794 elm->rec_type != cursor->right_bound->rec_type ||
1795 elm->key != cursor->right_bound->key) {
1796 break;
1797 }
1798
1799 /*
1800 * Stop if the right-hand bound's create_tid does not
47197d71 1801 * need to be corrected.
32c90105
MD
1802 */
1803 if (cursor->right_bound->create_tid >= tid)
1804 break;
1805
32c90105
MD
1806 rhb = kmalloc(sizeof(*rhb), M_HAMMER, M_WAITOK|M_ZERO);
1807 rhb->node = cursor->parent;
1808 rhb->index = cursor->parent_index;
1809 hammer_ref_node(rhb->node);
1810 hammer_lock_sh(&rhb->node->lock);
1811 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
1812
1813 hammer_cursor_up(cursor);
1814 }
1815
1816 /*
1817 * now safely adjust the right hand bound for each rhb. This may
1818 * also require taking the right side of the tree and iterating down
1819 * ITS left side.
1820 */
1821 error = 0;
1822 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1823 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
32c90105
MD
1824 if (error)
1825 break;
1826 TAILQ_REMOVE(&rhb_list, rhb, entry);
1827 hammer_unlock(&rhb->node->lock);
1828 hammer_rel_node(rhb->node);
1829 kfree(rhb, M_HAMMER);
1830
1831 switch (cursor->node->ondisk->type) {
1832 case HAMMER_BTREE_TYPE_INTERNAL:
1833 /*
1834 * Right-boundary for parent at internal node
1835 * is one element to the right of the element whos
1836 * right boundary needs adjusting. We must then
1837 * traverse down the left side correcting any left
1838 * bounds (which may now be too far to the left).
1839 */
1840 ++cursor->index;
1841 error = hammer_btree_correct_lhb(cursor, tid);
1842 break;
32c90105
MD
1843 default:
1844 panic("hammer_btree_correct_rhb(): Bad node type");
1845 error = EINVAL;
1846 break;
1847 }
1848 }
1849
1850 /*
1851 * Cleanup
1852 */
1853 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1854 TAILQ_REMOVE(&rhb_list, rhb, entry);
1855 hammer_unlock(&rhb->node->lock);
1856 hammer_rel_node(rhb->node);
1857 kfree(rhb, M_HAMMER);
1858 }
1859 error = hammer_cursor_seek(cursor, orig_node, orig_index);
1860 hammer_unlock(&orig_node->lock);
1861 hammer_rel_node(orig_node);
1862 return (error);
1863}
1864
1865/*
1866 * Similar to rhb (in fact, rhb calls lhb), but corrects the left hand
1867 * bound going downward starting at the current cursor position.
1868 *
1869 * This function does not restore the cursor after use.
1870 */
1871int
1872hammer_btree_correct_lhb(hammer_cursor_t cursor, hammer_tid_t tid)
1873{
1874 struct hammer_rhb_list rhb_list;
1875 hammer_base_elm_t elm;
1876 hammer_base_elm_t cmp;
1877 struct hammer_rhb *rhb;
1878 int error;
1879
1880 TAILQ_INIT(&rhb_list);
1881
1882 cmp = &cursor->node->ondisk->elms[cursor->index].base;
1883
1884 /*
1885 * Record the node and traverse down the left-hand side for all
1886 * matching records needing a boundary correction.
1887 */
1888 error = 0;
1889 for (;;) {
1890 rhb = kmalloc(sizeof(*rhb), M_HAMMER, M_WAITOK|M_ZERO);
1891 rhb->node = cursor->node;
1892 rhb->index = cursor->index;
1893 hammer_ref_node(rhb->node);
1894 hammer_lock_sh(&rhb->node->lock);
1895 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
1896
1897 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
1898 /*
1899 * Nothing to traverse down if we are at the right
1900 * boundary of an internal node.
1901 */
1902 if (cursor->index == cursor->node->ondisk->count)
1903 break;
1904 } else {
1905 elm = &cursor->node->ondisk->elms[cursor->index].base;
1906 if (elm->btype == HAMMER_BTREE_TYPE_RECORD)
1907 break;
47197d71 1908 panic("Illegal leaf record type %02x", elm->btype);
32c90105
MD
1909 }
1910 error = hammer_cursor_down(cursor);
1911 if (error)
1912 break;
1913
1914 elm = &cursor->node->ondisk->elms[cursor->index].base;
1915 if (elm->obj_id != cmp->obj_id ||
1916 elm->rec_type != cmp->rec_type ||
1917 elm->key != cmp->key) {
1918 break;
1919 }
1920 if (elm->create_tid >= tid)
1921 break;
1922
1923 }
1924
1925 /*
1926 * Now we can safely adjust the left-hand boundary from the bottom-up.
1927 * The last element we remove from the list is the caller's right hand
1928 * boundary, which must also be adjusted.
1929 */
1930 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1931 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
1932 if (error)
1933 break;
1934 TAILQ_REMOVE(&rhb_list, rhb, entry);
1935 hammer_unlock(&rhb->node->lock);
1936 hammer_rel_node(rhb->node);
1937 kfree(rhb, M_HAMMER);
1938
1939 elm = &cursor->node->ondisk->elms[cursor->index].base;
1940 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
36f82b23 1941 hammer_modify_node(cursor->trans, cursor->node,
19619882
MD
1942 &elm->create_tid,
1943 sizeof(elm->create_tid));
32c90105 1944 elm->create_tid = tid;
10a5d1ba 1945 hammer_modify_node_done(cursor->node);
32c90105
MD
1946 } else {
1947 panic("hammer_btree_correct_lhb(): Bad element type");
1948 }
1949 }
1950
1951 /*
1952 * Cleanup
1953 */
1954 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1955 TAILQ_REMOVE(&rhb_list, rhb, entry);
1956 hammer_unlock(&rhb->node->lock);
1957 hammer_rel_node(rhb->node);
1958 kfree(rhb, M_HAMMER);
1959 }
1960 return (error);
1961}
1962
427e5fc6 1963/*
f36a9737
MD
1964 * Attempt to remove the locked, empty or want-to-be-empty B-Tree node at
1965 * (cursor->node). Returns 0 on success, EDEADLK if we could not complete
1966 * the operation due to a deadlock, or some other error.
8cd0a023 1967 *
f36a9737
MD
1968 * This routine is always called with an empty, locked leaf but may recurse
1969 * into want-to-be-empty parents as part of its operation.
b3deaf57 1970 *
f36a9737
MD
1971 * On return the cursor may end up pointing to an internal node, suitable
1972 * for further iteration but not for an immediate insertion or deletion.
8cd0a023 1973 */
f36a9737 1974static int
46fe7ae1 1975btree_remove(hammer_cursor_t cursor)
8cd0a023
MD
1976{
1977 hammer_node_ondisk_t ondisk;
195c19a1 1978 hammer_btree_elm_t elm;
195c19a1 1979 hammer_node_t node;
8cd0a023 1980 hammer_node_t parent;
fe7678ee 1981 const int esize = sizeof(*elm);
8cd0a023 1982 int error;
8cd0a023 1983
fe7678ee
MD
1984 node = cursor->node;
1985
47197d71
MD
1986 /*
1987 * When deleting the root of the filesystem convert it to
1988 * an empty leaf node. Internal nodes cannot be empty.
1989 */
fe7678ee 1990 if (node->ondisk->parent == 0) {
f36a9737 1991 KKASSERT(cursor->parent == NULL);
36f82b23 1992 hammer_modify_node_all(cursor->trans, node);
fe7678ee 1993 ondisk = node->ondisk;
195c19a1
MD
1994 ondisk->type = HAMMER_BTREE_TYPE_LEAF;
1995 ondisk->count = 0;
10a5d1ba 1996 hammer_modify_node_done(node);
b3deaf57 1997 cursor->index = 0;
47197d71 1998 return(0);
8cd0a023
MD
1999 }
2000
2001 /*
f36a9737
MD
2002 * Attempt to remove the parent's reference to the child. If the
2003 * parent would become empty we have to recurse. If we fail we
2004 * leave the parent pointing to an empty leaf node.
8cd0a023 2005 */
fe7678ee 2006 parent = cursor->parent;
fe7678ee 2007
f36a9737
MD
2008 if (parent->ondisk->count == 1) {
2009 /*
2010 * This special cursor_up_locked() call leaves the original
2011 * node exclusively locked and referenced, leaves the
2012 * original parent locked (as the new node), and locks the
2013 * new parent. It can return EDEADLK.
2014 */
2015 error = hammer_cursor_up_locked(cursor);
2016 if (error == 0) {
2017 error = btree_remove(cursor);
2018 if (error == 0) {
2019 hammer_modify_node_all(cursor->trans, node);
2020 ondisk = node->ondisk;
2021 ondisk->type = HAMMER_BTREE_TYPE_DELETED;
2022 ondisk->count = 0;
2023 hammer_modify_node_done(node);
2024 hammer_flush_node(node);
2025 hammer_delete_node(cursor->trans, node);
2026 } else {
2027 kprintf("Warning: BTREE_REMOVE: Defering "
2028 "parent removal1 @ %016llx, skipping\n",
2029 node->node_offset);
2030 }
2031 hammer_unlock(&node->lock);
2032 hammer_rel_node(node);
2033 } else {
2034 kprintf("Warning: BTREE_REMOVE: Defering parent "
2035 "removal2 @ %016llx, skipping\n",
2036 node->node_offset);
2037 }
2038 } else {
2039 KKASSERT(parent->ondisk->count > 1);
6a37e7e4 2040
f36a9737
MD
2041 /*
2042 * Delete the subtree reference in the parent
2043 */
2044 hammer_modify_node_all(cursor->trans, parent);
2045 ondisk = parent->ondisk;
2046 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
2047 elm = &ondisk->elms[cursor->parent_index];
2048 KKASSERT(elm->internal.subtree_offset == node->node_offset);
2049 KKASSERT(ondisk->count > 0);
2050 bcopy(&elm[1], &elm[0],
2051 (ondisk->count - cursor->parent_index) * esize);
2052 --ondisk->count;
10a5d1ba 2053 hammer_modify_node_done(parent);
f36a9737
MD
2054 hammer_flush_node(node);
2055 hammer_delete_node(cursor->trans, node);
6a37e7e4 2056
f36a9737
MD
2057 /*
2058 * cursor->node is invalid, cursor up to make the cursor
2059 * valid again.
2060 */
2061 error = hammer_cursor_up(cursor);
6a37e7e4 2062 }
f36a9737 2063 return (error);
6a37e7e4
MD
2064}
2065
7f7c1f84 2066/*
fe7678ee
MD
2067 * The element (elm) has been moved to a new internal node (node).
2068 *
2069 * If the element represents a pointer to an internal node that node's
2070 * parent must be adjusted to the element's new location.
2071 *
6a37e7e4 2072 * XXX deadlock potential here with our exclusive locks
7f7c1f84 2073 */
7f7c1f84 2074int
36f82b23
MD
2075btree_set_parent(hammer_transaction_t trans, hammer_node_t node,
2076 hammer_btree_elm_t elm)
7f7c1f84 2077{
7f7c1f84
MD
2078 hammer_node_t child;
2079 int error;
2080
2081 error = 0;
2082
fe7678ee 2083 switch(elm->base.btype) {
7f7c1f84 2084 case HAMMER_BTREE_TYPE_INTERNAL:
fe7678ee 2085 case HAMMER_BTREE_TYPE_LEAF:
19619882
MD
2086 child = hammer_get_node(node->hmp, elm->internal.subtree_offset,
2087 0, &error);
7f7c1f84 2088 if (error == 0) {
c9b9e29d 2089 hammer_modify_node_field(trans, child, parent);
7f7c1f84 2090 child->ondisk->parent = node->node_offset;
10a5d1ba 2091 hammer_modify_node_done(child);
7f7c1f84
MD
2092 hammer_rel_node(child);
2093 }
2094 break;
7f7c1f84 2095 default:
fe7678ee 2096 break;
7f7c1f84
MD
2097 }
2098 return(error);
2099}
2100
b33e2cc0
MD
2101/*
2102 * Exclusively lock all the children of node. This is used by the split
2103 * code to prevent anyone from accessing the children of a cursor node
2104 * while we fix-up its parent offset.
2105 *
2106 * If we don't lock the children we can really mess up cursors which block
2107 * trying to cursor-up into our node.
2108 *
b33e2cc0
MD
2109 * On failure EDEADLK (or some other error) is returned. If a deadlock
2110 * error is returned the cursor is adjusted to block on termination.
2111 */
2112int
2113hammer_btree_lock_children(hammer_cursor_t cursor,
2114 struct hammer_node_locklist **locklistp)
2115{
2116 hammer_node_t node;
2117 hammer_node_locklist_t item;
2118 hammer_node_ondisk_t ondisk;
2119 hammer_btree_elm_t elm;
b33e2cc0
MD
2120 hammer_node_t child;
2121 int error;
2122 int i;
2123
2124 node = cursor->node;
2125 ondisk = node->ondisk;
2126 error = 0;
7bc5b8c2
MD
2127
2128 /*
2129 * We really do not want to block on I/O with exclusive locks held,
2130 * pre-get the children before trying to lock the mess.
2131 */
2132 for (i = 0; i < ondisk->count; ++i) {
cb51be26 2133 ++hammer_stats_btree_elements;
7bc5b8c2
MD
2134 elm = &ondisk->elms[i];
2135 if (elm->base.btype != HAMMER_BTREE_TYPE_LEAF &&
2136 elm->base.btype != HAMMER_BTREE_TYPE_INTERNAL) {
2137 continue;
2138 }
2139 child = hammer_get_node(node->hmp,
2140 elm->internal.subtree_offset,
2141 0, &error);
2142 if (child)
2143 hammer_rel_node(child);
2144 }
2145
2146 /*
2147 * Do it for real
2148 */
b33e2cc0 2149 for (i = 0; error == 0 && i < ondisk->count; ++i) {
cb51be26 2150 ++hammer_stats_btree_elements;
b33e2cc0
MD
2151 elm = &ondisk->elms[i];
2152
b33e2cc0
MD
2153 switch(elm->base.btype) {
2154 case HAMMER_BTREE_TYPE_INTERNAL:
2155 case HAMMER_BTREE_TYPE_LEAF:
f36a9737 2156 KKASSERT(elm->internal.subtree_offset != 0);
40043e7f 2157 child = hammer_get_node(node->hmp,
b33e2cc0 2158 elm->internal.subtree_offset,
19619882 2159 0, &error);
b33e2cc0 2160 break;
b33e2cc0 2161 default:
47197d71 2162 child = NULL;
b33e2cc0
MD
2163 break;
2164 }
2165 if (child) {
2166 if (hammer_lock_ex_try(&child->lock) != 0) {
2167 if (cursor->deadlk_node == NULL) {
1ff9f58e 2168 cursor->deadlk_node = child;
b33e2cc0
MD
2169 hammer_ref_node(cursor->deadlk_node);
2170 }
2171 error = EDEADLK;
a84a197d 2172 hammer_rel_node(child);
b33e2cc0
MD
2173 } else {
2174 item = kmalloc(sizeof(*item),
2175 M_HAMMER, M_WAITOK);
2176 item->next = *locklistp;
2177 item->node = child;
2178 *locklistp = item;
2179 }
2180 }
2181 }
2182 if (error)
2183 hammer_btree_unlock_children(locklistp);
2184 return(error);
2185}
2186
2187
2188/*
2189 * Release previously obtained node locks.
2190 */
2f85fa4d 2191void
b33e2cc0
MD
2192hammer_btree_unlock_children(struct hammer_node_locklist **locklistp)
2193{
2194 hammer_node_locklist_t item;
2195
2196 while ((item = *locklistp) != NULL) {
2197 *locklistp = item->next;
2198 hammer_unlock(&item->node->lock);
2199 hammer_rel_node(item->node);
2200 kfree(item, M_HAMMER);
2201 }
2202}
2203
8cd0a023
MD
2204/************************************************************************
2205 * MISCELLANIOUS SUPPORT *
2206 ************************************************************************/
2207
2208/*
d26d0ae9 2209 * Compare two B-Tree elements, return -N, 0, or +N (e.g. similar to strcmp).
8cd0a023 2210 *
d113fda1 2211 * Note that for this particular function a return value of -1, 0, or +1
9582c7da 2212 * can denote a match if create_tid is otherwise discounted. A create_tid
d5530d22 2213 * of zero is considered to be 'infinity' in comparisons.
d113fda1 2214 *
8cd0a023 2215 * See also hammer_rec_rb_compare() and hammer_rec_cmp() in hammer_object.c.
8cd0a023
MD
2216 */
2217int
2218hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2)
2219{
2f85fa4d
MD
2220 if (key1->localization < key2->localization)
2221 return(-5);
2222 if (key1->localization > key2->localization)
2223 return(5);
2224
d26d0ae9
MD
2225 if (key1->obj_id < key2->obj_id)
2226 return(-4);
2227 if (key1->obj_id > key2->obj_id)
2228 return(4);
8cd0a023 2229
d26d0ae9
MD
2230 if (key1->rec_type < key2->rec_type)
2231 return(-3);
2232 if (key1->rec_type > key2->rec_type)
2233 return(3);
8cd0a023 2234
8cd0a023
MD
2235 if (key1->key < key2->key)
2236 return(-2);
2237 if (key1->key > key2->key)
2238 return(2);
d113fda1 2239
d5530d22 2240 /*
9582c7da
MD
2241 * A create_tid of zero indicates a record which is undeletable
2242 * and must be considered to have a value of positive infinity.
d5530d22 2243 */
9582c7da
MD
2244 if (key1->create_tid == 0) {
2245 if (key2->create_tid == 0)
d5530d22
MD
2246 return(0);
2247 return(1);
2248 }
9582c7da 2249 if (key2->create_tid == 0)
d5530d22 2250 return(-1);
9582c7da 2251 if (key1->create_tid < key2->create_tid)
d113fda1 2252 return(-1);
9582c7da 2253 if (key1->create_tid > key2->create_tid)
d113fda1 2254 return(1);
8cd0a023
MD
2255 return(0);
2256}
2257
c0ade690 2258/*
d5530d22
MD
2259 * Test a timestamp against an element to determine whether the
2260 * element is visible. A timestamp of 0 means 'infinity'.
c0ade690
MD
2261 */
2262int
d5530d22 2263hammer_btree_chkts(hammer_tid_t asof, hammer_base_elm_t base)
c0ade690 2264{
d5530d22
MD
2265 if (asof == 0) {
2266 if (base->delete_tid)
2267 return(1);
2268 return(0);
2269 }
2270 if (asof < base->create_tid)
d26d0ae9 2271 return(-1);
d5530d22 2272 if (base->delete_tid && asof >= base->delete_tid)
d26d0ae9 2273 return(1);
c0ade690
MD
2274 return(0);
2275}
2276
8cd0a023
MD
2277/*
2278 * Create a separator half way inbetween key1 and key2. For fields just
d5530d22
MD
2279 * one unit apart, the separator will match key2. key1 is on the left-hand
2280 * side and key2 is on the right-hand side.
8cd0a023 2281 *
9391cded 2282 * key2 must be >= the separator. It is ok for the separator to match key2.
36f82b23 2283 *
9391cded
MD
2284 * NOTE: Even if key1 does not match key2, the separator may wind up matching
2285 * key2.
2286 *
2287 * NOTE: It might be beneficial to just scrap this whole mess and just
2288 * set the separator to key2.
8cd0a023
MD
2289 */
2290#define MAKE_SEPARATOR(key1, key2, dest, field) \
2291 dest->field = key1->field + ((key2->field - key1->field + 1) >> 1);
2292
2293static void
2294hammer_make_separator(hammer_base_elm_t key1, hammer_base_elm_t key2,
2295 hammer_base_elm_t dest)
2296{
2297 bzero(dest, sizeof(*dest));
d5530d22 2298
9391cded
MD
2299 dest->rec_type = key2->rec_type;
2300 dest->key = key2->key;
2f85fa4d 2301 dest->obj_id = key2->obj_id;
9391cded
MD
2302 dest->create_tid = key2->create_tid;
2303
2f85fa4d
MD
2304 MAKE_SEPARATOR(key1, key2, dest, localization);
2305 if (key1->localization == key2->localization) {
2306 MAKE_SEPARATOR(key1, key2, dest, obj_id);
2307 if (key1->obj_id == key2->obj_id) {
2308 MAKE_SEPARATOR(key1, key2, dest, rec_type);
2309 if (key1->rec_type == key2->rec_type) {
2310 MAKE_SEPARATOR(key1, key2, dest, key);
2311 /*
2312 * Don't bother creating a separator for
2313 * create_tid, which also conveniently avoids
2314 * having to handle the create_tid == 0
2315 * (infinity) case. Just leave create_tid
2316 * set to key2.
2317 *
2318 * Worst case, dest matches key2 exactly,
2319 * which is acceptable.
2320 */
2321 }
d5530d22 2322 }
d113fda1 2323 }
8cd0a023
MD
2324}
2325
2326#undef MAKE_SEPARATOR
2327
2328/*
2329 * Return whether a generic internal or leaf node is full
2330 */
2331static int
2332btree_node_is_full(hammer_node_ondisk_t node)
2333{
2334 switch(node->type) {
2335 case HAMMER_BTREE_TYPE_INTERNAL:
2336 if (node->count == HAMMER_BTREE_INT_ELMS)
2337 return(1);
2338 break;
2339 case HAMMER_BTREE_TYPE_LEAF:
2340 if (node->count == HAMMER_BTREE_LEAF_ELMS)
2341 return(1);
2342 break;
2343 default:
2344 panic("illegal btree subtype");
2345 }
2346 return(0);
2347}
9944ae54 2348
8cd0a023
MD
2349#if 0
2350static int
2351btree_max_elements(u_int8_t type)
2352{
2353 if (type == HAMMER_BTREE_TYPE_LEAF)
2354 return(HAMMER_BTREE_LEAF_ELMS);
2355 if (type == HAMMER_BTREE_TYPE_INTERNAL)
2356 return(HAMMER_BTREE_INT_ELMS);
2357 panic("btree_max_elements: bad type %d\n", type);
2358}
2359#endif
2360
c0ade690
MD
2361void
2362hammer_print_btree_node(hammer_node_ondisk_t ondisk)
2363{
2364 hammer_btree_elm_t elm;
2365 int i;
2366
47197d71 2367 kprintf("node %p count=%d parent=%016llx type=%c\n",
c0ade690
MD
2368 ondisk, ondisk->count, ondisk->parent, ondisk->type);
2369
2370 /*
2371 * Dump both boundary elements if an internal node
2372 */
2373 if (ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
2374 for (i = 0; i <= ondisk->count; ++i) {
2375 elm = &ondisk->elms[i];
2376 hammer_print_btree_elm(elm, ondisk->type, i);
2377 }
2378 } else {
2379 for (i = 0; i < ondisk->count; ++i) {
2380 elm = &ondisk->elms[i];
2381 hammer_print_btree_elm(elm, ondisk->type, i);
2382 }
2383 }
2384}
2385
2386void
2387hammer_print_btree_elm(hammer_btree_elm_t elm, u_int8_t type, int i)
2388{
2389 kprintf(" %2d", i);
7dc57964 2390 kprintf("\tobj_id = %016llx\n", elm->base.obj_id);
c0ade690
MD
2391 kprintf("\tkey = %016llx\n", elm->base.key);
2392 kprintf("\tcreate_tid = %016llx\n", elm->base.create_tid);
2393 kprintf("\tdelete_tid = %016llx\n", elm->base.delete_tid);
2394 kprintf("\trec_type = %04x\n", elm->base.rec_type);
2395 kprintf("\tobj_type = %02x\n", elm->base.obj_type);
fe7678ee
MD
2396 kprintf("\tbtype = %02x (%c)\n",
2397 elm->base.btype,
2398 (elm->base.btype ? elm->base.btype : '?'));
2f85fa4d 2399 kprintf("\tlocalization = %02x\n", elm->base.localization);
fe7678ee
MD
2400
2401 switch(type) {
2402 case HAMMER_BTREE_TYPE_INTERNAL:
47197d71 2403 kprintf("\tsubtree_off = %016llx\n",
fe7678ee
MD
2404 elm->internal.subtree_offset);
2405 break;
fe7678ee 2406 case HAMMER_BTREE_TYPE_RECORD:
47197d71 2407 kprintf("\tdata_offset = %016llx\n", elm->leaf.data_offset);
c0ade690
MD
2408 kprintf("\tdata_len = %08x\n", elm->leaf.data_len);
2409 kprintf("\tdata_crc = %08x\n", elm->leaf.data_crc);
fe7678ee 2410 break;
c0ade690
MD
2411 }
2412}