usb ehci - Fix machine freezes from shutdown race (missing commit)
[dragonfly.git] / sys / vfs / hammer / hammer_btree.c
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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 *
5c8d05e2 34 * $DragonFly: src/sys/vfs/hammer/hammer_btree.c,v 1.76 2008/08/06 15:38:58 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
f36a9737
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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 int hammer_btree_mirror_propagate(hammer_cursor_t cursor,
91 hammer_tid_t mirror_tid);
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92static void hammer_make_separator(hammer_base_elm_t key1,
93 hammer_base_elm_t key2, hammer_base_elm_t dest);
4c038e17 94static void hammer_cursor_mirror_filter(hammer_cursor_t cursor);
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95
96/*
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97 * Iterate records after a search. The cursor is iterated forwards past
98 * the current record until a record matching the key-range requirements
99 * is found. ENOENT is returned if the iteration goes past the ending
6a37e7e4 100 * key.
66325755 101 *
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102 * The iteration is inclusive of key_beg and can be inclusive or exclusive
103 * of key_end depending on whether HAMMER_CURSOR_END_INCLUSIVE is set.
66325755 104 *
eaeff70d 105 * When doing an as-of search (cursor->asof != 0), key_beg.create_tid
9582c7da 106 * may be modified by B-Tree functions.
d5530d22 107 *
8cd0a023 108 * cursor->key_beg may or may not be modified by this function during
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109 * the iteration. XXX future - in case of an inverted lock we may have
110 * to reinitiate the lookup and set key_beg to properly pick up where we
111 * left off.
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112 *
113 * NOTE! EDEADLK *CANNOT* be returned by this procedure.
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114 */
115int
8cd0a023 116hammer_btree_iterate(hammer_cursor_t cursor)
66325755 117{
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118 hammer_node_ondisk_t node;
119 hammer_btree_elm_t elm;
1d4077f7 120 int error = 0;
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121 int r;
122 int s;
123
124 /*
8cd0a023 125 * Skip past the current record
66325755 126 */
8cd0a023 127 node = cursor->node->ondisk;
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128 if (node == NULL)
129 return(ENOENT);
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130 if (cursor->index < node->count &&
131 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
66325755 132 ++cursor->index;
c0ade690 133 }
66325755 134
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135 /*
136 * Loop until an element is found or we are done.
137 */
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138 for (;;) {
139 /*
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140 * We iterate up the tree and then index over one element
141 * while we are at the last element in the current node.
142 *
47197d71 143 * If we are at the root of the filesystem, cursor_up
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144 * returns ENOENT.
145 *
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146 * XXX this could be optimized by storing the information in
147 * the parent reference.
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148 *
149 * XXX we can lose the node lock temporarily, this could mess
150 * up our scan.
66325755 151 */
47637bff 152 ++hammer_stats_btree_iterations;
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153 hammer_flusher_clean_loose_ios(cursor->trans->hmp);
154
8cd0a023 155 if (cursor->index == node->count) {
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156 if (hammer_debug_btree) {
157 kprintf("BRACKETU %016llx[%d] -> %016llx[%d] (td=%p)\n",
158 cursor->node->node_offset,
159 cursor->index,
160 (cursor->parent ? cursor->parent->node_offset : -1),
161 cursor->parent_index,
162 curthread);
163 }
164 KKASSERT(cursor->parent == NULL || cursor->parent->ondisk->elms[cursor->parent_index].internal.subtree_offset == cursor->node->node_offset);
6a37e7e4 165 error = hammer_cursor_up(cursor);
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166 if (error)
167 break;
46fe7ae1 168 /* reload stale pointer */
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169 node = cursor->node->ondisk;
170 KKASSERT(cursor->index != node->count);
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171
172 /*
173 * If we are reblocking we want to return internal
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174 * nodes. Note that the internal node will be
175 * returned multiple times, on each upward recursion
176 * from its children. The caller selects which
177 * revisit it cares about (usually first or last only).
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178 */
179 if (cursor->flags & HAMMER_CURSOR_REBLOCKING) {
180 cursor->flags |= HAMMER_CURSOR_ATEDISK;
181 return(0);
182 }
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183 ++cursor->index;
184 continue;
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185 }
186
187 /*
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188 * Check internal or leaf element. Determine if the record
189 * at the cursor has gone beyond the end of our range.
66325755 190 *
47197d71 191 * We recurse down through internal nodes.
66325755 192 */
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193 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
194 elm = &node->elms[cursor->index];
c82af904 195
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196 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
197 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
b3deaf57 198 if (hammer_debug_btree) {
2f85fa4d 199 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d (td=%p)\n",
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200 cursor->node->node_offset,
201 cursor->index,
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202 elm[0].internal.base.obj_id,
203 elm[0].internal.base.rec_type,
204 elm[0].internal.base.key,
2f85fa4d 205 elm[0].internal.base.localization,
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206 r,
207 curthread
b3deaf57 208 );
2f85fa4d 209 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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210 cursor->node->node_offset,
211 cursor->index + 1,
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212 elm[1].internal.base.obj_id,
213 elm[1].internal.base.rec_type,
214 elm[1].internal.base.key,
2f85fa4d 215 elm[1].internal.base.localization,
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216 s
217 );
218 }
219
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220 if (r < 0) {
221 error = ENOENT;
222 break;
66325755 223 }
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224 if (r == 0 && (cursor->flags &
225 HAMMER_CURSOR_END_INCLUSIVE) == 0) {
d26d0ae9 226 error = ENOENT;
8cd0a023 227 break;
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228 }
229 KKASSERT(s <= 0);
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230
231 /*
f36a9737 232 * Better not be zero
6a37e7e4 233 */
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234 KKASSERT(elm->internal.subtree_offset != 0);
235
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236 /*
237 * If running the mirror filter see if we can skip
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238 * one or more entire sub-trees. If we can we
239 * return the internal mode and the caller processes
240 * the skipped range (see mirror_read)
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241 */
242 if (cursor->flags & HAMMER_CURSOR_MIRROR_FILTERED) {
243 if (elm->internal.mirror_tid <
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244 cursor->cmirror->mirror_tid) {
245 hammer_cursor_mirror_filter(cursor);
246 return(0);
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247 }
248 }
249
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250 error = hammer_cursor_down(cursor);
251 if (error)
252 break;
253 KKASSERT(cursor->index == 0);
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254 /* reload stale pointer */
255 node = cursor->node->ondisk;
fe7678ee 256 continue;
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257 } else {
258 elm = &node->elms[cursor->index];
259 r = hammer_btree_cmp(&cursor->key_end, &elm->base);
b3deaf57 260 if (hammer_debug_btree) {
2f85fa4d 261 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
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262 cursor->node->node_offset,
263 cursor->index,
264 (elm[0].leaf.base.btype ?
265 elm[0].leaf.base.btype : '?'),
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266 elm[0].leaf.base.obj_id,
267 elm[0].leaf.base.rec_type,
268 elm[0].leaf.base.key,
2f85fa4d 269 elm[0].leaf.base.localization,
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270 r
271 );
272 }
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273 if (r < 0) {
274 error = ENOENT;
275 break;
276 }
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277
278 /*
279 * We support both end-inclusive and
280 * end-exclusive searches.
281 */
282 if (r == 0 &&
283 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
284 error = ENOENT;
285 break;
286 }
287
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288 switch(elm->leaf.base.btype) {
289 case HAMMER_BTREE_TYPE_RECORD:
290 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
291 hammer_btree_chkts(cursor->asof, &elm->base)) {
292 ++cursor->index;
293 continue;
294 }
1d4077f7 295 error = 0;
fe7678ee 296 break;
fe7678ee
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297 default:
298 error = EINVAL;
299 break;
d26d0ae9 300 }
fe7678ee
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301 if (error)
302 break;
66325755 303 }
46fe7ae1
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304 /*
305 * node pointer invalid after loop
306 */
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307
308 /*
d26d0ae9 309 * Return entry
66325755 310 */
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311 if (hammer_debug_btree) {
312 int i = cursor->index;
313 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 314 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
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315 cursor->node, i,
316 elm->internal.base.obj_id,
317 elm->internal.base.rec_type,
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318 elm->internal.base.key,
319 elm->internal.base.localization
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320 );
321 }
d26d0ae9 322 return(0);
427e5fc6 323 }
66325755 324 return(error);
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325}
326
4c038e17
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327/*
328 * We hit an internal element that we could skip as part of a mirroring
329 * scan. Calculate the entire range being skipped.
330 *
331 * It is important to include any gaps between the parent's left_bound
332 * and the node's left_bound, and same goes for the right side.
333 */
334static void
335hammer_cursor_mirror_filter(hammer_cursor_t cursor)
336{
337 struct hammer_cmirror *cmirror;
338 hammer_node_ondisk_t ondisk;
339 hammer_btree_elm_t elm;
340
341 ondisk = cursor->node->ondisk;
342 cmirror = cursor->cmirror;
343
344 /*
345 * Calculate the skipped range
346 */
347 elm = &ondisk->elms[cursor->index];
348 if (cursor->index == 0)
349 cmirror->skip_beg = *cursor->left_bound;
350 else
351 cmirror->skip_beg = elm->internal.base;
352 while (cursor->index < ondisk->count) {
353 if (elm->internal.mirror_tid >= cmirror->mirror_tid)
354 break;
355 ++cursor->index;
356 ++elm;
357 }
358 if (cursor->index == ondisk->count)
359 cmirror->skip_end = *cursor->right_bound;
360 else
361 cmirror->skip_end = elm->internal.base;
362
363 /*
364 * clip the returned result.
365 */
366 if (hammer_btree_cmp(&cmirror->skip_beg, &cursor->key_beg) < 0)
367 cmirror->skip_beg = cursor->key_beg;
368 if (hammer_btree_cmp(&cmirror->skip_end, &cursor->key_end) > 0)
369 cmirror->skip_end = cursor->key_end;
370}
371
32c90105
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372/*
373 * Iterate in the reverse direction. This is used by the pruning code to
374 * avoid overlapping records.
375 */
376int
377hammer_btree_iterate_reverse(hammer_cursor_t cursor)
378{
379 hammer_node_ondisk_t node;
380 hammer_btree_elm_t elm;
f75df937 381 int error = 0;
32c90105
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382 int r;
383 int s;
384
4c038e17
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385 /* mirror filtering not supported for reverse iteration */
386 KKASSERT ((cursor->flags & HAMMER_CURSOR_MIRROR_FILTERED) == 0);
387
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388 /*
389 * Skip past the current record. For various reasons the cursor
390 * may end up set to -1 or set to point at the end of the current
391 * node. These cases must be addressed.
392 */
393 node = cursor->node->ondisk;
394 if (node == NULL)
395 return(ENOENT);
396 if (cursor->index != -1 &&
397 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
398 --cursor->index;
399 }
400 if (cursor->index == cursor->node->ondisk->count)
401 --cursor->index;
402
403 /*
404 * Loop until an element is found or we are done.
405 */
406 for (;;) {
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407 ++hammer_stats_btree_iterations;
408 hammer_flusher_clean_loose_ios(cursor->trans->hmp);
409
32c90105
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410 /*
411 * We iterate up the tree and then index over one element
412 * while we are at the last element in the current node.
32c90105
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413 */
414 if (cursor->index == -1) {
415 error = hammer_cursor_up(cursor);
416 if (error) {
417 cursor->index = 0; /* sanity */
418 break;
419 }
420 /* reload stale pointer */
421 node = cursor->node->ondisk;
422 KKASSERT(cursor->index != node->count);
423 --cursor->index;
424 continue;
425 }
426
427 /*
428 * Check internal or leaf element. Determine if the record
429 * at the cursor has gone beyond the end of our range.
430 *
47197d71 431 * We recurse down through internal nodes.
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432 */
433 KKASSERT(cursor->index != node->count);
434 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
435 elm = &node->elms[cursor->index];
436 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
437 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
438 if (hammer_debug_btree) {
2f85fa4d 439 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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440 cursor->node->node_offset,
441 cursor->index,
442 elm[0].internal.base.obj_id,
443 elm[0].internal.base.rec_type,
444 elm[0].internal.base.key,
2f85fa4d 445 elm[0].internal.base.localization,
32c90105
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446 r
447 );
2f85fa4d 448 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
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449 cursor->node->node_offset,
450 cursor->index + 1,
451 elm[1].internal.base.obj_id,
452 elm[1].internal.base.rec_type,
453 elm[1].internal.base.key,
2f85fa4d 454 elm[1].internal.base.localization,
32c90105
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455 s
456 );
457 }
458
459 if (s >= 0) {
460 error = ENOENT;
461 break;
462 }
463 KKASSERT(r >= 0);
464
465 /*
f36a9737 466 * Better not be zero
32c90105 467 */
f36a9737
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468 KKASSERT(elm->internal.subtree_offset != 0);
469
470 error = hammer_cursor_down(cursor);
471 if (error)
472 break;
473 KKASSERT(cursor->index == 0);
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474 /* reload stale pointer */
475 node = cursor->node->ondisk;
f36a9737
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476
477 /* this can assign -1 if the leaf was empty */
478 cursor->index = node->count - 1;
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479 continue;
480 } else {
481 elm = &node->elms[cursor->index];
482 s = hammer_btree_cmp(&cursor->key_beg, &elm->base);
483 if (hammer_debug_btree) {
2f85fa4d 484 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
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485 cursor->node->node_offset,
486 cursor->index,
487 (elm[0].leaf.base.btype ?
488 elm[0].leaf.base.btype : '?'),
489 elm[0].leaf.base.obj_id,
490 elm[0].leaf.base.rec_type,
491 elm[0].leaf.base.key,
2f85fa4d 492 elm[0].leaf.base.localization,
32c90105
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493 s
494 );
495 }
496 if (s > 0) {
497 error = ENOENT;
498 break;
499 }
500
501 switch(elm->leaf.base.btype) {
502 case HAMMER_BTREE_TYPE_RECORD:
503 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
504 hammer_btree_chkts(cursor->asof, &elm->base)) {
505 --cursor->index;
506 continue;
507 }
f75df937 508 error = 0;
32c90105 509 break;
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510 default:
511 error = EINVAL;
512 break;
513 }
514 if (error)
515 break;
516 }
517 /*
518 * node pointer invalid after loop
519 */
520
521 /*
522 * Return entry
523 */
524 if (hammer_debug_btree) {
525 int i = cursor->index;
526 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 527 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
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528 cursor->node, i,
529 elm->internal.base.obj_id,
530 elm->internal.base.rec_type,
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531 elm->internal.base.key,
532 elm->internal.base.localization
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533 );
534 }
535 return(0);
536 }
537 return(error);
538}
539
427e5fc6 540/*
8cd0a023 541 * Lookup cursor->key_beg. 0 is returned on success, ENOENT if the entry
6a37e7e4
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542 * could not be found, EDEADLK if inserting and a retry is needed, and a
543 * fatal error otherwise. When retrying, the caller must terminate the
eaeff70d 544 * cursor and reinitialize it. EDEADLK cannot be returned if not inserting.
8cd0a023
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545 *
546 * The cursor is suitably positioned for a deletion on success, and suitably
eaeff70d
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547 * positioned for an insertion on ENOENT if HAMMER_CURSOR_INSERT was
548 * specified.
427e5fc6 549 *
47197d71 550 * The cursor may begin anywhere, the search will traverse the tree in
8cd0a023 551 * either direction to locate the requested element.
eaeff70d
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552 *
553 * Most of the logic implementing historical searches is handled here. We
9582c7da
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554 * do an initial lookup with create_tid set to the asof TID. Due to the
555 * way records are laid out, a backwards iteration may be required if
eaeff70d
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556 * ENOENT is returned to locate the historical record. Here's the
557 * problem:
558 *
9582c7da 559 * create_tid: 10 15 20
eaeff70d
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560 * LEAF1 LEAF2
561 * records: (11) (18)
562 *
9582c7da
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563 * Lets say we want to do a lookup AS-OF timestamp 17. We will traverse
564 * LEAF2 but the only record in LEAF2 has a create_tid of 18, which is
565 * not visible and thus causes ENOENT to be returned. We really need
566 * to check record 11 in LEAF1. If it also fails then the search fails
567 * (e.g. it might represent the range 11-16 and thus still not match our
f36a9737
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568 * AS-OF timestamp of 17). Note that LEAF1 could be empty, requiring
569 * further iterations.
b33e2cc0 570 *
9582c7da
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571 * If this case occurs btree_search() will set HAMMER_CURSOR_CREATE_CHECK
572 * and the cursor->create_check TID if an iteration might be needed.
573 * In the above example create_check would be set to 14.
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574 */
575int
8cd0a023 576hammer_btree_lookup(hammer_cursor_t cursor)
427e5fc6 577{
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578 int error;
579
98da6d8c
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580 KKASSERT ((cursor->flags & HAMMER_CURSOR_INSERT) == 0 ||
581 cursor->trans->sync_lock_refs > 0);
cb51be26 582 ++hammer_stats_btree_lookups;
d5530d22 583 if (cursor->flags & HAMMER_CURSOR_ASOF) {
eaeff70d 584 KKASSERT((cursor->flags & HAMMER_CURSOR_INSERT) == 0);
9582c7da 585 cursor->key_beg.create_tid = cursor->asof;
eaeff70d 586 for (;;) {
9582c7da 587 cursor->flags &= ~HAMMER_CURSOR_CREATE_CHECK;
d5530d22 588 error = btree_search(cursor, 0);
b33e2cc0 589 if (error != ENOENT ||
9582c7da 590 (cursor->flags & HAMMER_CURSOR_CREATE_CHECK) == 0) {
b33e2cc0
MD
591 /*
592 * Stop if no error.
593 * Stop if error other then ENOENT.
594 * Stop if ENOENT and not special case.
595 */
eaeff70d
MD
596 break;
597 }
32c90105
MD
598 if (hammer_debug_btree) {
599 kprintf("CREATE_CHECK %016llx\n",
600 cursor->create_check);
601 }
9582c7da 602 cursor->key_beg.create_tid = cursor->create_check;
eaeff70d
MD
603 /* loop */
604 }
d5530d22
MD
605 } else {
606 error = btree_search(cursor, 0);
607 }
bf3b416b 608 if (error == 0)
8cd0a023 609 error = hammer_btree_extract(cursor, cursor->flags);
66325755
MD
610 return(error);
611}
612
d26d0ae9
MD
613/*
614 * Execute the logic required to start an iteration. The first record
615 * located within the specified range is returned and iteration control
616 * flags are adjusted for successive hammer_btree_iterate() calls.
3214ade6
MD
617 *
618 * Set ATEDISK so a low-level caller can call btree_first/btree_iterate
619 * in a loop without worrying about it. Higher-level merged searches will
620 * adjust the flag appropriately.
d26d0ae9
MD
621 */
622int
623hammer_btree_first(hammer_cursor_t cursor)
624{
625 int error;
626
627 error = hammer_btree_lookup(cursor);
628 if (error == ENOENT) {
629 cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
630 error = hammer_btree_iterate(cursor);
631 }
632 cursor->flags |= HAMMER_CURSOR_ATEDISK;
633 return(error);
634}
635
32c90105
MD
636/*
637 * Similarly but for an iteration in the reverse direction.
814387f6
MD
638 *
639 * Set ATEDISK when iterating backwards to skip the current entry,
640 * which after an ENOENT lookup will be pointing beyond our end point.
3214ade6
MD
641 *
642 * Set ATEDISK so a low-level caller can call btree_last/btree_iterate_reverse
643 * in a loop without worrying about it. Higher-level merged searches will
644 * adjust the flag appropriately.
32c90105
MD
645 */
646int
647hammer_btree_last(hammer_cursor_t cursor)
648{
649 struct hammer_base_elm save;
650 int error;
651
652 save = cursor->key_beg;
653 cursor->key_beg = cursor->key_end;
654 error = hammer_btree_lookup(cursor);
655 cursor->key_beg = save;
656 if (error == ENOENT ||
657 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
814387f6 658 cursor->flags |= HAMMER_CURSOR_ATEDISK;
32c90105
MD
659 error = hammer_btree_iterate_reverse(cursor);
660 }
661 cursor->flags |= HAMMER_CURSOR_ATEDISK;
662 return(error);
663}
664
8cd0a023
MD
665/*
666 * Extract the record and/or data associated with the cursor's current
667 * position. Any prior record or data stored in the cursor is replaced.
668 * The cursor must be positioned at a leaf node.
669 *
47197d71 670 * NOTE: All extractions occur at the leaf of the B-Tree.
8cd0a023 671 */
66325755 672int
8cd0a023 673hammer_btree_extract(hammer_cursor_t cursor, int flags)
66325755 674{
8cd0a023
MD
675 hammer_node_ondisk_t node;
676 hammer_btree_elm_t elm;
47197d71 677 hammer_off_t data_off;
bac808fe 678 hammer_mount_t hmp;
19619882 679 int32_t data_len;
427e5fc6 680 int error;
427e5fc6 681
8cd0a023 682 /*
427e5fc6
MD
683 * The case where the data reference resolves to the same buffer
684 * as the record reference must be handled.
685 */
8cd0a023 686 node = cursor->node->ondisk;
8cd0a023 687 elm = &node->elms[cursor->index];
40043e7f
MD
688 cursor->data = NULL;
689 hmp = cursor->node->hmp;
66325755 690
d26d0ae9 691 /*
fe7678ee 692 * There is nothing to extract for an internal element.
d26d0ae9 693 */
fe7678ee
MD
694 if (node->type == HAMMER_BTREE_TYPE_INTERNAL)
695 return(EINVAL);
696
47197d71
MD
697 /*
698 * Only record types have data.
699 */
fe7678ee 700 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
11ad5ade 701 cursor->leaf = &elm->leaf;
4a2796f3
MD
702
703 if ((flags & HAMMER_CURSOR_GET_DATA) == 0)
704 return(0);
47197d71 705 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
4a2796f3 706 return(0);
47197d71 707 data_off = elm->leaf.data_offset;
19619882 708 data_len = elm->leaf.data_len;
47197d71 709 if (data_off == 0)
4a2796f3 710 return(0);
d26d0ae9 711
4a2796f3
MD
712 /*
713 * Load the data
714 */
715 KKASSERT(data_len >= 0 && data_len <= HAMMER_XBUFSIZE);
716 cursor->data = hammer_bread_ext(hmp, data_off, data_len,
717 &error, &cursor->data_buffer);
e469566b
MD
718 if (hammer_crc_test_leaf(cursor->data, &elm->leaf) == 0) {
719 kprintf("CRC DATA @ %016llx/%d FAILED\n",
720 elm->leaf.data_offset, elm->leaf.data_len);
4c286c36
MD
721 if (hammer_debug_debug & 0x0001)
722 Debugger("CRC FAILED: DATA");
723 if (cursor->trans->flags & HAMMER_TRANSF_CRCDOM)
724 error = EDOM; /* less critical (mirroring) */
725 else
726 error = EIO; /* critical */
e469566b 727 }
427e5fc6
MD
728 return(error);
729}
730
731
732/*
8cd0a023
MD
733 * Insert a leaf element into the B-Tree at the current cursor position.
734 * The cursor is positioned such that the element at and beyond the cursor
735 * are shifted to make room for the new record.
736 *
a89aec1b 737 * The caller must call hammer_btree_lookup() with the HAMMER_CURSOR_INSERT
8cd0a023
MD
738 * flag set and that call must return ENOENT before this function can be
739 * called.
740 *
d36ec43b 741 * The caller may depend on the cursor's exclusive lock after return to
1f07f686 742 * interlock frontend visibility (see HAMMER_RECF_CONVERT_DELETE).
d36ec43b 743 *
8cd0a023 744 * ENOSPC is returned if there is no room to insert a new record.
427e5fc6
MD
745 */
746int
602c6cb8
MD
747hammer_btree_insert(hammer_cursor_t cursor, hammer_btree_leaf_elm_t elm,
748 int *doprop)
427e5fc6 749{
8cd0a023 750 hammer_node_ondisk_t node;
427e5fc6 751 int i;
6a37e7e4
MD
752 int error;
753
602c6cb8 754 *doprop = 0;
7bc5b8c2 755 if ((error = hammer_cursor_upgrade_node(cursor)) != 0)
6a37e7e4 756 return(error);
cb51be26 757 ++hammer_stats_btree_inserts;
427e5fc6 758
427e5fc6
MD
759 /*
760 * Insert the element at the leaf node and update the count in the
761 * parent. It is possible for parent to be NULL, indicating that
47197d71
MD
762 * the filesystem's ROOT B-Tree node is a leaf itself, which is
763 * possible. The root inode can never be deleted so the leaf should
764 * never be empty.
427e5fc6
MD
765 *
766 * Remember that the right-hand boundary is not included in the
767 * count.
768 */
36f82b23 769 hammer_modify_node_all(cursor->trans, cursor->node);
8cd0a023 770 node = cursor->node->ondisk;
427e5fc6 771 i = cursor->index;
fe7678ee 772 KKASSERT(elm->base.btype != 0);
8cd0a023
MD
773 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
774 KKASSERT(node->count < HAMMER_BTREE_LEAF_ELMS);
775 if (i != node->count) {
776 bcopy(&node->elms[i], &node->elms[i+1],
777 (node->count - i) * sizeof(*elm));
778 }
11ad5ade 779 node->elms[i].leaf = *elm;
8cd0a023 780 ++node->count;
e4a5ff06 781 hammer_cursor_inserted_element(cursor->node, i);
c82af904
MD
782
783 /*
784 * Update the leaf node's aggregate mirror_tid for mirroring
785 * support.
786 */
602c6cb8 787 if (node->mirror_tid < elm->base.delete_tid) {
c82af904 788 node->mirror_tid = elm->base.delete_tid;
602c6cb8
MD
789 *doprop = 1;
790 }
791 if (node->mirror_tid < elm->base.create_tid) {
c82af904 792 node->mirror_tid = elm->base.create_tid;
602c6cb8 793 *doprop = 1;
c82af904 794 }
602c6cb8 795 hammer_modify_node_done(cursor->node);
c82af904 796
eaeff70d 797 /*
47197d71 798 * Debugging sanity checks.
eaeff70d 799 */
11ad5ade
MD
800 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->base) <= 0);
801 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->base) > 0);
eaeff70d 802 if (i) {
11ad5ade 803 KKASSERT(hammer_btree_cmp(&node->elms[i-1].leaf.base, &elm->base) < 0);
eaeff70d 804 }
b3deaf57 805 if (i != node->count - 1)
11ad5ade 806 KKASSERT(hammer_btree_cmp(&node->elms[i+1].leaf.base, &elm->base) > 0);
b3deaf57 807
427e5fc6
MD
808 return(0);
809}
810
811/*
fe7678ee 812 * Delete a record from the B-Tree at the current cursor position.
8cd0a023
MD
813 * The cursor is positioned such that the current element is the one
814 * to be deleted.
815 *
195c19a1
MD
816 * On return the cursor will be positioned after the deleted element and
817 * MAY point to an internal node. It will be suitable for the continuation
818 * of an iteration but not for an insertion or deletion.
8cd0a023 819 *
195c19a1 820 * Deletions will attempt to partially rebalance the B-Tree in an upward
f36a9737
MD
821 * direction, but will terminate rather then deadlock. Empty internal nodes
822 * are never allowed by a deletion which deadlocks may end up giving us an
823 * empty leaf. The pruner will clean up and rebalance the tree.
46fe7ae1
MD
824 *
825 * This function can return EDEADLK, requiring the caller to retry the
826 * operation after clearing the deadlock.
427e5fc6
MD
827 */
828int
8cd0a023 829hammer_btree_delete(hammer_cursor_t cursor)
427e5fc6 830{
8cd0a023
MD
831 hammer_node_ondisk_t ondisk;
832 hammer_node_t node;
833 hammer_node_t parent;
8cd0a023 834 int error;
427e5fc6
MD
835 int i;
836
98da6d8c 837 KKASSERT (cursor->trans->sync_lock_refs > 0);
6a37e7e4
MD
838 if ((error = hammer_cursor_upgrade(cursor)) != 0)
839 return(error);
cb51be26 840 ++hammer_stats_btree_deletes;
6a37e7e4 841
427e5fc6 842 /*
8cd0a023 843 * Delete the element from the leaf node.
427e5fc6 844 *
8cd0a023 845 * Remember that leaf nodes do not have boundaries.
427e5fc6 846 */
8cd0a023
MD
847 node = cursor->node;
848 ondisk = node->ondisk;
427e5fc6
MD
849 i = cursor->index;
850
8cd0a023 851 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_LEAF);
fe7678ee 852 KKASSERT(i >= 0 && i < ondisk->count);
36f82b23 853 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
854 if (i + 1 != ondisk->count) {
855 bcopy(&ondisk->elms[i+1], &ondisk->elms[i],
856 (ondisk->count - i - 1) * sizeof(ondisk->elms[0]));
857 }
858 --ondisk->count;
10a5d1ba 859 hammer_modify_node_done(node);
b3bad96f 860 hammer_cursor_deleted_element(node, i);
fe7678ee
MD
861
862 /*
863 * Validate local parent
864 */
865 if (ondisk->parent) {
8cd0a023 866 parent = cursor->parent;
fe7678ee
MD
867
868 KKASSERT(parent != NULL);
869 KKASSERT(parent->node_offset == ondisk->parent);
427e5fc6 870 }
427e5fc6 871
8cd0a023 872 /*
fe7678ee 873 * If the leaf becomes empty it must be detached from the parent,
47197d71 874 * potentially recursing through to the filesystem root.
195c19a1
MD
875 *
876 * This may reposition the cursor at one of the parent's of the
877 * current node.
6a37e7e4
MD
878 *
879 * Ignore deadlock errors, that simply means that btree_remove
f36a9737 880 * was unable to recurse and had to leave us with an empty leaf.
8cd0a023 881 */
b3deaf57 882 KKASSERT(cursor->index <= ondisk->count);
8cd0a023 883 if (ondisk->count == 0) {
f36a9737 884 error = btree_remove(cursor);
6a37e7e4
MD
885 if (error == EDEADLK)
886 error = 0;
8cd0a023 887 } else {
8cd0a023
MD
888 error = 0;
889 }
eaeff70d
MD
890 KKASSERT(cursor->parent == NULL ||
891 cursor->parent_index < cursor->parent->ondisk->count);
8cd0a023
MD
892 return(error);
893}
427e5fc6
MD
894
895/*
8cd0a023
MD
896 * PRIMAY B-TREE SEARCH SUPPORT PROCEDURE
897 *
47197d71 898 * Search the filesystem B-Tree for cursor->key_beg, return the matching node.
8cd0a023 899 *
d26d0ae9
MD
900 * The search can begin ANYWHERE in the B-Tree. As a first step the search
901 * iterates up the tree as necessary to properly position itself prior to
902 * actually doing the sarch.
903 *
8cd0a023 904 * INSERTIONS: The search will split full nodes and leaves on its way down
d26d0ae9
MD
905 * and guarentee that the leaf it ends up on is not full. If we run out
906 * of space the search continues to the leaf (to position the cursor for
907 * the spike), but ENOSPC is returned.
427e5fc6 908 *
fbc6e32a
MD
909 * The search is only guarenteed to end up on a leaf if an error code of 0
910 * is returned, or if inserting and an error code of ENOENT is returned.
d26d0ae9 911 * Otherwise it can stop at an internal node. On success a search returns
47197d71 912 * a leaf node.
eaeff70d
MD
913 *
914 * COMPLEXITY WARNING! This is the core B-Tree search code for the entire
915 * filesystem, and it is not simple code. Please note the following facts:
916 *
917 * - Internal node recursions have a boundary on the left AND right. The
9582c7da 918 * right boundary is non-inclusive. The create_tid is a generic part
eaeff70d
MD
919 * of the key for internal nodes.
920 *
47197d71 921 * - Leaf nodes contain terminal elements only now.
eaeff70d
MD
922 *
923 * - Filesystem lookups typically set HAMMER_CURSOR_ASOF, indicating a
b33e2cc0
MD
924 * historical search. ASOF and INSERT are mutually exclusive. When
925 * doing an as-of lookup btree_search() checks for a right-edge boundary
9582c7da
MD
926 * case. If while recursing down the left-edge differs from the key
927 * by ONLY its create_tid, HAMMER_CURSOR_CREATE_CHECK is set along
928 * with cursor->create_check. This is used by btree_lookup() to iterate.
929 * The iteration backwards because as-of searches can wind up going
b33e2cc0 930 * down the wrong branch of the B-Tree.
427e5fc6 931 */
8cd0a023 932static
427e5fc6 933int
8cd0a023 934btree_search(hammer_cursor_t cursor, int flags)
427e5fc6 935{
8cd0a023 936 hammer_node_ondisk_t node;
61aeeb33 937 hammer_btree_elm_t elm;
8cd0a023 938 int error;
d26d0ae9 939 int enospc = 0;
8cd0a023
MD
940 int i;
941 int r;
b33e2cc0 942 int s;
8cd0a023
MD
943
944 flags |= cursor->flags;
cb51be26 945 ++hammer_stats_btree_searches;
8cd0a023 946
b3deaf57 947 if (hammer_debug_btree) {
2f85fa4d 948 kprintf("SEARCH %016llx[%d] %016llx %02x key=%016llx cre=%016llx lo=%02x (td = %p)\n",
eaeff70d
MD
949 cursor->node->node_offset,
950 cursor->index,
b3deaf57
MD
951 cursor->key_beg.obj_id,
952 cursor->key_beg.rec_type,
d113fda1 953 cursor->key_beg.key,
a84a197d 954 cursor->key_beg.create_tid,
2f85fa4d 955 cursor->key_beg.localization,
a84a197d 956 curthread
b3deaf57 957 );
a84a197d
MD
958 if (cursor->parent)
959 kprintf("SEARCHP %016llx[%d] (%016llx/%016llx %016llx/%016llx) (%p/%p %p/%p)\n",
960 cursor->parent->node_offset, cursor->parent_index,
961 cursor->left_bound->obj_id,
962 cursor->parent->ondisk->elms[cursor->parent_index].internal.base.obj_id,
963 cursor->right_bound->obj_id,
964 cursor->parent->ondisk->elms[cursor->parent_index+1].internal.base.obj_id,
965 cursor->left_bound,
966 &cursor->parent->ondisk->elms[cursor->parent_index],
967 cursor->right_bound,
968 &cursor->parent->ondisk->elms[cursor->parent_index+1]
969 );
b3deaf57
MD
970 }
971
8cd0a023
MD
972 /*
973 * Move our cursor up the tree until we find a node whos range covers
47197d71 974 * the key we are trying to locate.
8cd0a023
MD
975 *
976 * The left bound is inclusive, the right bound is non-inclusive.
47197d71 977 * It is ok to cursor up too far.
8cd0a023 978 */
b33e2cc0
MD
979 for (;;) {
980 r = hammer_btree_cmp(&cursor->key_beg, cursor->left_bound);
981 s = hammer_btree_cmp(&cursor->key_beg, cursor->right_bound);
982 if (r >= 0 && s < 0)
983 break;
9944ae54 984 KKASSERT(cursor->parent);
cb51be26 985 ++hammer_stats_btree_iterations;
6a37e7e4 986 error = hammer_cursor_up(cursor);
8cd0a023
MD
987 if (error)
988 goto done;
427e5fc6 989 }
427e5fc6 990
b33e2cc0
MD
991 /*
992 * The delete-checks below are based on node, not parent. Set the
993 * initial delete-check based on the parent.
994 */
9582c7da
MD
995 if (r == 1) {
996 KKASSERT(cursor->left_bound->create_tid != 1);
997 cursor->create_check = cursor->left_bound->create_tid - 1;
998 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0
MD
999 }
1000
8cd0a023 1001 /*
47197d71 1002 * We better have ended up with a node somewhere.
8cd0a023 1003 */
47197d71 1004 KKASSERT(cursor->node != NULL);
8cd0a023
MD
1005
1006 /*
1007 * If we are inserting we can't start at a full node if the parent
1008 * is also full (because there is no way to split the node),
b33e2cc0 1009 * continue running up the tree until the requirement is satisfied
47197d71 1010 * or we hit the root of the filesystem.
9582c7da
MD
1011 *
1012 * (If inserting we aren't doing an as-of search so we don't have
1013 * to worry about create_check).
8cd0a023 1014 */
61aeeb33 1015 while ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
eaeff70d
MD
1016 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
1017 if (btree_node_is_full(cursor->node->ondisk) == 0)
1018 break;
1019 } else {
47197d71 1020 if (btree_node_is_full(cursor->node->ondisk) ==0)
eaeff70d
MD
1021 break;
1022 }
b33e2cc0
MD
1023 if (cursor->node->ondisk->parent == 0 ||
1024 cursor->parent->ondisk->count != HAMMER_BTREE_INT_ELMS) {
8cd0a023 1025 break;
b33e2cc0 1026 }
cb51be26 1027 ++hammer_stats_btree_iterations;
6a37e7e4 1028 error = hammer_cursor_up(cursor);
47197d71 1029 /* node may have become stale */
8cd0a023
MD
1030 if (error)
1031 goto done;
427e5fc6 1032 }
427e5fc6 1033
8cd0a023
MD
1034 /*
1035 * Push down through internal nodes to locate the requested key.
1036 */
8cd0a023
MD
1037 node = cursor->node->ondisk;
1038 while (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
8cd0a023
MD
1039 /*
1040 * Scan the node to find the subtree index to push down into.
fbc6e32a 1041 * We go one-past, then back-up.
d113fda1 1042 *
fe7678ee
MD
1043 * We must proactively remove deleted elements which may
1044 * have been left over from a deadlocked btree_remove().
1045 *
eaeff70d 1046 * The left and right boundaries are included in the loop
d5530d22 1047 * in order to detect edge cases.
9944ae54 1048 *
9582c7da 1049 * If the separator only differs by create_tid (r == 1)
eaeff70d
MD
1050 * and we are doing an as-of search, we may end up going
1051 * down a branch to the left of the one containing the
1052 * desired key. This requires numerous special cases.
8cd0a023 1053 */
47637bff 1054 ++hammer_stats_btree_iterations;
46fe7ae1 1055 if (hammer_debug_btree) {
47197d71 1056 kprintf("SEARCH-I %016llx count=%d\n",
46fe7ae1
MD
1057 cursor->node->node_offset,
1058 node->count);
1059 }
af209b0f
MD
1060
1061 /*
1062 * Try to shortcut the search before dropping into the
1063 * linear loop. Locate the first node where r <= 1.
1064 */
1065 i = hammer_btree_search_node(&cursor->key_beg, node);
1066 while (i <= node->count) {
cb51be26 1067 ++hammer_stats_btree_elements;
61aeeb33
MD
1068 elm = &node->elms[i];
1069 r = hammer_btree_cmp(&cursor->key_beg, &elm->base);
b33e2cc0
MD
1070 if (hammer_debug_btree > 2) {
1071 kprintf(" IELM %p %d r=%d\n",
1072 &node->elms[i], i, r);
1073 }
9582c7da 1074 if (r < 0)
8cd0a023 1075 break;
9582c7da
MD
1076 if (r == 1) {
1077 KKASSERT(elm->base.create_tid != 1);
1078 cursor->create_check = elm->base.create_tid - 1;
1079 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0 1080 }
af209b0f 1081 ++i;
8cd0a023 1082 }
eaeff70d 1083 if (hammer_debug_btree) {
46fe7ae1
MD
1084 kprintf("SEARCH-I preI=%d/%d r=%d\n",
1085 i, node->count, r);
eaeff70d 1086 }
8cd0a023
MD
1087
1088 /*
9944ae54
MD
1089 * These cases occur when the parent's idea of the boundary
1090 * is wider then the child's idea of the boundary, and
1091 * require special handling. If not inserting we can
1092 * terminate the search early for these cases but the
1093 * child's boundaries cannot be unconditionally modified.
8cd0a023 1094 */
fbc6e32a 1095 if (i == 0) {
9944ae54
MD
1096 /*
1097 * If i == 0 the search terminated to the LEFT of the
1098 * left_boundary but to the RIGHT of the parent's left
1099 * boundary.
1100 */
fbc6e32a 1101 u_int8_t save;
d26d0ae9 1102
eaeff70d
MD
1103 elm = &node->elms[0];
1104
1105 /*
1106 * If we aren't inserting we can stop here.
1107 */
11ad5ade
MD
1108 if ((flags & (HAMMER_CURSOR_INSERT |
1109 HAMMER_CURSOR_PRUNING)) == 0) {
fbc6e32a
MD
1110 cursor->index = 0;
1111 return(ENOENT);
1112 }
9944ae54 1113
d5530d22
MD
1114 /*
1115 * Correct a left-hand boundary mismatch.
6a37e7e4 1116 *
f36a9737
MD
1117 * We can only do this if we can upgrade the lock,
1118 * and synchronized as a background cursor (i.e.
1119 * inserting or pruning).
10a5d1ba
MD
1120 *
1121 * WARNING: We can only do this if inserting, i.e.
1122 * we are running on the backend.
d5530d22 1123 */
eaeff70d
MD
1124 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1125 return(error);
10a5d1ba 1126 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
c9b9e29d
MD
1127 hammer_modify_node_field(cursor->trans, cursor->node,
1128 elms[0]);
fe7678ee 1129 save = node->elms[0].base.btype;
d5530d22 1130 node->elms[0].base = *cursor->left_bound;
fe7678ee 1131 node->elms[0].base.btype = save;
10a5d1ba 1132 hammer_modify_node_done(cursor->node);
9944ae54 1133 } else if (i == node->count + 1) {
d26d0ae9 1134 /*
9944ae54
MD
1135 * If i == node->count + 1 the search terminated to
1136 * the RIGHT of the right boundary but to the LEFT
eaeff70d
MD
1137 * of the parent's right boundary. If we aren't
1138 * inserting we can stop here.
d113fda1 1139 *
9944ae54
MD
1140 * Note that the last element in this case is
1141 * elms[i-2] prior to adjustments to 'i'.
d26d0ae9 1142 */
9944ae54 1143 --i;
11ad5ade
MD
1144 if ((flags & (HAMMER_CURSOR_INSERT |
1145 HAMMER_CURSOR_PRUNING)) == 0) {
9944ae54 1146 cursor->index = i;
eaeff70d 1147 return (ENOENT);
d26d0ae9
MD
1148 }
1149
d5530d22
MD
1150 /*
1151 * Correct a right-hand boundary mismatch.
1152 * (actual push-down record is i-2 prior to
1153 * adjustments to i).
6a37e7e4 1154 *
f36a9737
MD
1155 * We can only do this if we can upgrade the lock,
1156 * and synchronized as a background cursor (i.e.
1157 * inserting or pruning).
10a5d1ba
MD
1158 *
1159 * WARNING: We can only do this if inserting, i.e.
1160 * we are running on the backend.
d5530d22 1161 */
eaeff70d
MD
1162 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1163 return(error);
9944ae54 1164 elm = &node->elms[i];
10a5d1ba 1165 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
36f82b23
MD
1166 hammer_modify_node(cursor->trans, cursor->node,
1167 &elm->base, sizeof(elm->base));
d5530d22 1168 elm->base = *cursor->right_bound;
10a5d1ba 1169 hammer_modify_node_done(cursor->node);
d5530d22 1170 --i;
fbc6e32a
MD
1171 } else {
1172 /*
9944ae54
MD
1173 * The push-down index is now i - 1. If we had
1174 * terminated on the right boundary this will point
1175 * us at the last element.
fbc6e32a
MD
1176 */
1177 --i;
1178 }
8cd0a023 1179 cursor->index = i;
6a37e7e4 1180 elm = &node->elms[i];
8cd0a023 1181
b3deaf57 1182 if (hammer_debug_btree) {
47197d71 1183 kprintf("RESULT-I %016llx[%d] %016llx %02x "
2f85fa4d 1184 "key=%016llx cre=%016llx lo=%02x\n",
eaeff70d
MD
1185 cursor->node->node_offset,
1186 i,
b3deaf57
MD
1187 elm->internal.base.obj_id,
1188 elm->internal.base.rec_type,
d113fda1 1189 elm->internal.base.key,
2f85fa4d
MD
1190 elm->internal.base.create_tid,
1191 elm->internal.base.localization
b3deaf57
MD
1192 );
1193 }
1194
6a37e7e4 1195 /*
f36a9737 1196 * We better have a valid subtree offset.
6a37e7e4 1197 */
f36a9737 1198 KKASSERT(elm->internal.subtree_offset != 0);
6a37e7e4 1199
8cd0a023
MD
1200 /*
1201 * Handle insertion and deletion requirements.
1202 *
1203 * If inserting split full nodes. The split code will
1204 * adjust cursor->node and cursor->index if the current
1205 * index winds up in the new node.
61aeeb33 1206 *
9944ae54
MD
1207 * If inserting and a left or right edge case was detected,
1208 * we cannot correct the left or right boundary and must
1209 * prepend and append an empty leaf node in order to make
1210 * the boundary correction.
1211 *
61aeeb33
MD
1212 * If we run out of space we set enospc and continue on
1213 * to a leaf to provide the spike code with a good point
47197d71 1214 * of entry.
8cd0a023 1215 */
61aeeb33 1216 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
fe7678ee 1217 if (btree_node_is_full(node)) {
8cd0a023 1218 error = btree_split_internal(cursor);
d26d0ae9
MD
1219 if (error) {
1220 if (error != ENOSPC)
1221 goto done;
1222 enospc = 1;
d26d0ae9 1223 }
8cd0a023
MD
1224 /*
1225 * reload stale pointers
1226 */
1227 i = cursor->index;
1228 node = cursor->node->ondisk;
1229 }
d26d0ae9 1230 }
427e5fc6
MD
1231
1232 /*
8cd0a023 1233 * Push down (push into new node, existing node becomes
d26d0ae9 1234 * the parent) and continue the search.
427e5fc6 1235 */
8cd0a023 1236 error = hammer_cursor_down(cursor);
47197d71 1237 /* node may have become stale */
8cd0a023
MD
1238 if (error)
1239 goto done;
1240 node = cursor->node->ondisk;
427e5fc6 1241 }
427e5fc6 1242
8cd0a023
MD
1243 /*
1244 * We are at a leaf, do a linear search of the key array.
d26d0ae9
MD
1245 *
1246 * On success the index is set to the matching element and 0
1247 * is returned.
1248 *
1249 * On failure the index is set to the insertion point and ENOENT
1250 * is returned.
8cd0a023
MD
1251 *
1252 * Boundaries are not stored in leaf nodes, so the index can wind
1253 * up to the left of element 0 (index == 0) or past the end of
f36a9737
MD
1254 * the array (index == node->count). It is also possible that the
1255 * leaf might be empty.
8cd0a023 1256 */
47637bff 1257 ++hammer_stats_btree_iterations;
fe7678ee 1258 KKASSERT (node->type == HAMMER_BTREE_TYPE_LEAF);
8cd0a023 1259 KKASSERT(node->count <= HAMMER_BTREE_LEAF_ELMS);
46fe7ae1 1260 if (hammer_debug_btree) {
47197d71 1261 kprintf("SEARCH-L %016llx count=%d\n",
46fe7ae1
MD
1262 cursor->node->node_offset,
1263 node->count);
1264 }
8cd0a023 1265
af209b0f
MD
1266 /*
1267 * Try to shortcut the search before dropping into the
1268 * linear loop. Locate the first node where r <= 1.
1269 */
1270 i = hammer_btree_search_node(&cursor->key_beg, node);
1271 while (i < node->count) {
cb51be26 1272 ++hammer_stats_btree_elements;
fe7678ee
MD
1273 elm = &node->elms[i];
1274
1275 r = hammer_btree_cmp(&cursor->key_beg, &elm->leaf.base);
427e5fc6 1276
d5530d22
MD
1277 if (hammer_debug_btree > 1)
1278 kprintf(" ELM %p %d r=%d\n", &node->elms[i], i, r);
1279
427e5fc6 1280 /*
fe7678ee 1281 * We are at a record element. Stop if we've flipped past
9582c7da
MD
1282 * key_beg, not counting the create_tid test. Allow the
1283 * r == 1 case (key_beg > element but differs only by its
1284 * create_tid) to fall through to the AS-OF check.
427e5fc6 1285 */
fe7678ee
MD
1286 KKASSERT (elm->leaf.base.btype == HAMMER_BTREE_TYPE_RECORD);
1287
9582c7da 1288 if (r < 0)
d5530d22 1289 goto failed;
af209b0f
MD
1290 if (r > 1) {
1291 ++i;
d5530d22 1292 continue;
af209b0f 1293 }
427e5fc6 1294
66325755 1295 /*
9582c7da 1296 * Check our as-of timestamp against the element.
66325755 1297 */
eaeff70d 1298 if (flags & HAMMER_CURSOR_ASOF) {
fe7678ee 1299 if (hammer_btree_chkts(cursor->asof,
d113fda1 1300 &node->elms[i].base) != 0) {
af209b0f 1301 ++i;
d113fda1
MD
1302 continue;
1303 }
eaeff70d
MD
1304 /* success */
1305 } else {
af209b0f
MD
1306 if (r > 0) { /* can only be +1 */
1307 ++i;
9582c7da 1308 continue;
af209b0f 1309 }
eaeff70d 1310 /* success */
66325755 1311 }
d5530d22
MD
1312 cursor->index = i;
1313 error = 0;
eaeff70d 1314 if (hammer_debug_btree) {
47197d71
MD
1315 kprintf("RESULT-L %016llx[%d] (SUCCESS)\n",
1316 cursor->node->node_offset, i);
eaeff70d 1317 }
d5530d22
MD
1318 goto done;
1319 }
1320
1321 /*
eaeff70d 1322 * The search of the leaf node failed. i is the insertion point.
d5530d22 1323 */
d5530d22 1324failed:
b3deaf57 1325 if (hammer_debug_btree) {
47197d71
MD
1326 kprintf("RESULT-L %016llx[%d] (FAILED)\n",
1327 cursor->node->node_offset, i);
b3deaf57
MD
1328 }
1329
8cd0a023
MD
1330 /*
1331 * No exact match was found, i is now at the insertion point.
1332 *
1333 * If inserting split a full leaf before returning. This
1334 * may have the side effect of adjusting cursor->node and
1335 * cursor->index.
1336 */
1337 cursor->index = i;
eaeff70d 1338 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0 &&
47197d71 1339 btree_node_is_full(node)) {
8cd0a023 1340 error = btree_split_leaf(cursor);
d26d0ae9
MD
1341 if (error) {
1342 if (error != ENOSPC)
1343 goto done;
1344 enospc = 1;
d26d0ae9
MD
1345 }
1346 /*
1347 * reload stale pointers
1348 */
8cd0a023
MD
1349 /* NOT USED
1350 i = cursor->index;
1351 node = &cursor->node->internal;
1352 */
8cd0a023 1353 }
d26d0ae9
MD
1354
1355 /*
1356 * We reached a leaf but did not find the key we were looking for.
1357 * If this is an insert we will be properly positioned for an insert
1358 * (ENOENT) or spike (ENOSPC) operation.
1359 */
1360 error = enospc ? ENOSPC : ENOENT;
8cd0a023 1361done:
427e5fc6
MD
1362 return(error);
1363}
1364
af209b0f
MD
1365/*
1366 * Heuristical search for the first element whos comparison is <= 1. May
1367 * return an index whos compare result is > 1 but may only return an index
1368 * whos compare result is <= 1 if it is the first element with that result.
1369 */
bcac4bbb 1370int
af209b0f
MD
1371hammer_btree_search_node(hammer_base_elm_t elm, hammer_node_ondisk_t node)
1372{
1373 int b;
1374 int s;
1375 int i;
1376 int r;
1377
1378 /*
1379 * Don't bother if the node does not have very many elements
1380 */
1381 b = 0;
1382 s = node->count;
1383 while (s - b > 4) {
1384 i = b + (s - b) / 2;
cb51be26 1385 ++hammer_stats_btree_elements;
af209b0f
MD
1386 r = hammer_btree_cmp(elm, &node->elms[i].leaf.base);
1387 if (r <= 1) {
1388 s = i;
1389 } else {
1390 b = i;
1391 }
1392 }
1393 return(b);
1394}
1395
8cd0a023 1396
427e5fc6 1397/************************************************************************
8cd0a023 1398 * SPLITTING AND MERGING *
427e5fc6
MD
1399 ************************************************************************
1400 *
1401 * These routines do all the dirty work required to split and merge nodes.
1402 */
1403
1404/*
8cd0a023 1405 * Split an internal node into two nodes and move the separator at the split
fe7678ee 1406 * point to the parent.
427e5fc6 1407 *
8cd0a023
MD
1408 * (cursor->node, cursor->index) indicates the element the caller intends
1409 * to push into. We will adjust node and index if that element winds
427e5fc6 1410 * up in the split node.
8cd0a023 1411 *
47197d71
MD
1412 * If we are at the root of the filesystem a new root must be created with
1413 * two elements, one pointing to the original root and one pointing to the
8cd0a023 1414 * newly allocated split node.
427e5fc6
MD
1415 */
1416static
1417int
8cd0a023 1418btree_split_internal(hammer_cursor_t cursor)
427e5fc6 1419{
8cd0a023
MD
1420 hammer_node_ondisk_t ondisk;
1421 hammer_node_t node;
1422 hammer_node_t parent;
1423 hammer_node_t new_node;
1424 hammer_btree_elm_t elm;
1425 hammer_btree_elm_t parent_elm;
1775b6a0 1426 struct hammer_node_lock lockroot;
36f82b23 1427 hammer_mount_t hmp = cursor->trans->hmp;
df2ccbac 1428 hammer_off_t hint;
427e5fc6
MD
1429 int parent_index;
1430 int made_root;
1431 int split;
1432 int error;
7f7c1f84 1433 int i;
8cd0a023 1434 const int esize = sizeof(*elm);
427e5fc6 1435
1775b6a0
MD
1436 hammer_node_lock_init(&lockroot, cursor->node);
1437 error = hammer_btree_lock_children(cursor, 1, &lockroot);
47197d71
MD
1438 if (error)
1439 goto done;
7bc5b8c2
MD
1440 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1441 goto done;
cb51be26 1442 ++hammer_stats_btree_splits;
6a37e7e4 1443
427e5fc6
MD
1444 /*
1445 * We are splitting but elms[split] will be promoted to the parent,
1446 * leaving the right hand node with one less element. If the
1447 * insertion point will be on the left-hand side adjust the split
1448 * point to give the right hand side one additional node.
1449 */
8cd0a023
MD
1450 node = cursor->node;
1451 ondisk = node->ondisk;
1452 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1453 if (cursor->index <= split)
1454 --split;
427e5fc6
MD
1455
1456 /*
47197d71
MD
1457 * If we are at the root of the filesystem, create a new root node
1458 * with 1 element and split normally. Avoid making major
1459 * modifications until we know the whole operation will work.
427e5fc6 1460 */
8cd0a023 1461 if (ondisk->parent == 0) {
df2ccbac
MD
1462 parent = hammer_alloc_btree(cursor->trans, node->node_offset,
1463 &error);
427e5fc6 1464 if (parent == NULL)
6a37e7e4 1465 goto done;
8cd0a023 1466 hammer_lock_ex(&parent->lock);
36f82b23 1467 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1468 ondisk = parent->ondisk;
1469 ondisk->count = 1;
1470 ondisk->parent = 0;
a56cb012 1471 ondisk->mirror_tid = node->ondisk->mirror_tid;
8cd0a023 1472 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1473 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1474 ondisk->elms[0].base.btype = node->ondisk->type;
8cd0a023 1475 ondisk->elms[0].internal.subtree_offset = node->node_offset;
47197d71 1476 ondisk->elms[1].base = hmp->root_btree_end;
10a5d1ba 1477 hammer_modify_node_done(parent);
fe7678ee 1478 /* ondisk->elms[1].base.btype - not used */
427e5fc6 1479 made_root = 1;
8cd0a023 1480 parent_index = 0; /* index of current node in parent */
427e5fc6
MD
1481 } else {
1482 made_root = 0;
8cd0a023
MD
1483 parent = cursor->parent;
1484 parent_index = cursor->parent_index;
427e5fc6 1485 }
427e5fc6 1486
df2ccbac
MD
1487 /*
1488 * Calculate a hint for the allocation of the new B-Tree node.
1489 * The most likely expansion is coming from the insertion point
1490 * at cursor->index, so try to localize the allocation of our
1491 * new node to accomodate that sub-tree.
1492 *
1493 * Use the right-most sub-tree when expandinging on the right edge.
1494 * This is a very common case when copying a directory tree.
1495 */
1496 if (cursor->index == ondisk->count)
1497 hint = ondisk->elms[cursor->index - 1].internal.subtree_offset;
1498 else
1499 hint = ondisk->elms[cursor->index].internal.subtree_offset;
1500
427e5fc6
MD
1501 /*
1502 * Split node into new_node at the split point.
1503 *
df2ccbac 1504 * B O O O P N N B <-- P = node->elms[split] (index 4)
427e5fc6
MD
1505 * 0 1 2 3 4 5 6 <-- subtree indices
1506 *
1507 * x x P x x
1508 * s S S s
1509 * / \
1510 * B O O O B B N N B <--- inner boundary points are 'P'
1511 * 0 1 2 3 4 5 6
427e5fc6 1512 */
df2ccbac 1513 new_node = hammer_alloc_btree(cursor->trans, hint, &error);
427e5fc6 1514 if (new_node == NULL) {
8cd0a023
MD
1515 if (made_root) {
1516 hammer_unlock(&parent->lock);
36f82b23 1517 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1518 hammer_rel_node(parent);
1519 }
6a37e7e4 1520 goto done;
427e5fc6 1521 }
8cd0a023 1522 hammer_lock_ex(&new_node->lock);
427e5fc6
MD
1523
1524 /*
8cd0a023 1525 * Create the new node. P becomes the left-hand boundary in the
427e5fc6
MD
1526 * new node. Copy the right-hand boundary as well.
1527 *
1528 * elm is the new separator.
1529 */
36f82b23
MD
1530 hammer_modify_node_noundo(cursor->trans, new_node);
1531 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
1532 ondisk = node->ondisk;
1533 elm = &ondisk->elms[split];
1534 bcopy(elm, &new_node->ondisk->elms[0],
1535 (ondisk->count - split + 1) * esize);
1536 new_node->ondisk->count = ondisk->count - split;
1537 new_node->ondisk->parent = parent->node_offset;
1538 new_node->ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
a56cb012 1539 new_node->ondisk->mirror_tid = ondisk->mirror_tid;
8cd0a023 1540 KKASSERT(ondisk->type == new_node->ondisk->type);
b3bad96f 1541 hammer_cursor_split_node(node, new_node, split);
427e5fc6
MD
1542
1543 /*
fe7678ee
MD
1544 * Cleanup the original node. Elm (P) becomes the new boundary,
1545 * its subtree_offset was moved to the new node. If we had created
427e5fc6
MD
1546 * a new root its parent pointer may have changed.
1547 */
8cd0a023 1548 elm->internal.subtree_offset = 0;
c0ade690 1549 ondisk->count = split;
427e5fc6
MD
1550
1551 /*
1552 * Insert the separator into the parent, fixup the parent's
1553 * reference to the original node, and reference the new node.
1554 * The separator is P.
1555 *
1556 * Remember that base.count does not include the right-hand boundary.
1557 */
36f82b23 1558 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1559 ondisk = parent->ondisk;
d26d0ae9 1560 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1561 parent_elm = &ondisk->elms[parent_index+1];
427e5fc6 1562 bcopy(parent_elm, parent_elm + 1,
8cd0a023
MD
1563 (ondisk->count - parent_index) * esize);
1564 parent_elm->internal.base = elm->base; /* separator P */
fe7678ee 1565 parent_elm->internal.base.btype = new_node->ondisk->type;
8cd0a023 1566 parent_elm->internal.subtree_offset = new_node->node_offset;
a56cb012 1567 parent_elm->internal.mirror_tid = new_node->ondisk->mirror_tid;
76376933 1568 ++ondisk->count;
10a5d1ba 1569 hammer_modify_node_done(parent);
b3bad96f 1570 hammer_cursor_inserted_element(parent, parent_index + 1);
427e5fc6 1571
7f7c1f84
MD
1572 /*
1573 * The children of new_node need their parent pointer set to new_node.
b33e2cc0
MD
1574 * The children have already been locked by
1575 * hammer_btree_lock_children().
7f7c1f84
MD
1576 */
1577 for (i = 0; i < new_node->ondisk->count; ++i) {
1578 elm = &new_node->ondisk->elms[i];
36f82b23 1579 error = btree_set_parent(cursor->trans, new_node, elm);
7f7c1f84
MD
1580 if (error) {
1581 panic("btree_split_internal: btree-fixup problem");
1582 }
1583 }
10a5d1ba 1584 hammer_modify_node_done(new_node);
7f7c1f84 1585
427e5fc6 1586 /*
47197d71 1587 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1588 */
1589 if (made_root) {
47197d71
MD
1590 hammer_volume_t volume;
1591
1592 volume = hammer_get_root_volume(hmp, &error);
1593 KKASSERT(error == 0);
1594
e8599db1
MD
1595 hammer_modify_volume_field(cursor->trans, volume,
1596 vol0_btree_root);
47197d71 1597 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1598 hammer_modify_volume_done(volume);
8cd0a023
MD
1599 node->ondisk->parent = parent->node_offset;
1600 if (cursor->parent) {
1601 hammer_unlock(&cursor->parent->lock);
1602 hammer_rel_node(cursor->parent);
1603 }
1604 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1605 hammer_rel_volume(volume, 0);
427e5fc6 1606 }
10a5d1ba 1607 hammer_modify_node_done(node);
427e5fc6
MD
1608
1609 /*
1610 * Ok, now adjust the cursor depending on which element the original
1611 * index was pointing at. If we are >= the split point the push node
1612 * is now in the new node.
1613 *
1614 * NOTE: If we are at the split point itself we cannot stay with the
1615 * original node because the push index will point at the right-hand
1616 * boundary, which is illegal.
8cd0a023
MD
1617 *
1618 * NOTE: The cursor's parent or parent_index must be adjusted for
1619 * the case where a new parent (new root) was created, and the case
1620 * where the cursor is now pointing at the split node.
427e5fc6
MD
1621 */
1622 if (cursor->index >= split) {
8cd0a023 1623 cursor->parent_index = parent_index + 1;
427e5fc6 1624 cursor->index -= split;
8cd0a023
MD
1625 hammer_unlock(&cursor->node->lock);
1626 hammer_rel_node(cursor->node);
1627 cursor->node = new_node; /* locked and ref'd */
1628 } else {
1629 cursor->parent_index = parent_index;
1630 hammer_unlock(&new_node->lock);
1631 hammer_rel_node(new_node);
427e5fc6 1632 }
76376933
MD
1633
1634 /*
1635 * Fixup left and right bounds
1636 */
1637 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1638 cursor->left_bound = &parent_elm[0].internal.base;
1639 cursor->right_bound = &parent_elm[1].internal.base;
b3deaf57
MD
1640 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1641 &cursor->node->ondisk->elms[0].internal.base) <= 0);
1642 KKASSERT(hammer_btree_cmp(cursor->right_bound,
9944ae54 1643 &cursor->node->ondisk->elms[cursor->node->ondisk->count].internal.base) >= 0);
76376933 1644
6a37e7e4 1645done:
1775b6a0 1646 hammer_btree_unlock_children(cursor, &lockroot);
6a37e7e4
MD
1647 hammer_cursor_downgrade(cursor);
1648 return (error);
427e5fc6
MD
1649}
1650
1651/*
1652 * Same as the above, but splits a full leaf node.
6a37e7e4
MD
1653 *
1654 * This function
427e5fc6
MD
1655 */
1656static
1657int
8cd0a023 1658btree_split_leaf(hammer_cursor_t cursor)
427e5fc6 1659{
8cd0a023
MD
1660 hammer_node_ondisk_t ondisk;
1661 hammer_node_t parent;
1662 hammer_node_t leaf;
47197d71 1663 hammer_mount_t hmp;
8cd0a023
MD
1664 hammer_node_t new_leaf;
1665 hammer_btree_elm_t elm;
1666 hammer_btree_elm_t parent_elm;
b3deaf57 1667 hammer_base_elm_t mid_boundary;
df2ccbac 1668 hammer_off_t hint;
427e5fc6
MD
1669 int parent_index;
1670 int made_root;
1671 int split;
1672 int error;
8cd0a023 1673 const size_t esize = sizeof(*elm);
427e5fc6 1674
6a37e7e4
MD
1675 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1676 return(error);
cb51be26 1677 ++hammer_stats_btree_splits;
6a37e7e4 1678
36f82b23
MD
1679 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1680 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1681 KKASSERT(hammer_btree_cmp(cursor->right_bound,
1682 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
1683
427e5fc6 1684 /*
8cd0a023
MD
1685 * Calculate the split point. If the insertion point will be on
1686 * the left-hand side adjust the split point to give the right
1687 * hand side one additional node.
fe7678ee
MD
1688 *
1689 * Spikes are made up of two leaf elements which cannot be
1690 * safely split.
427e5fc6 1691 */
8cd0a023
MD
1692 leaf = cursor->node;
1693 ondisk = leaf->ondisk;
1694 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1695 if (cursor->index <= split)
1696 --split;
1697 error = 0;
40043e7f 1698 hmp = leaf->hmp;
427e5fc6 1699
fe7678ee 1700 elm = &ondisk->elms[split];
fe7678ee 1701
36f82b23
MD
1702 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm[-1].leaf.base) <= 0);
1703 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->leaf.base) <= 0);
1704 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->leaf.base) > 0);
1705 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm[1].leaf.base) > 0);
1706
427e5fc6
MD
1707 /*
1708 * If we are at the root of the tree, create a new root node with
1709 * 1 element and split normally. Avoid making major modifications
1710 * until we know the whole operation will work.
1711 */
8cd0a023 1712 if (ondisk->parent == 0) {
df2ccbac
MD
1713 parent = hammer_alloc_btree(cursor->trans, leaf->node_offset,
1714 &error);
427e5fc6 1715 if (parent == NULL)
6a37e7e4 1716 goto done;
8cd0a023 1717 hammer_lock_ex(&parent->lock);
36f82b23 1718 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1719 ondisk = parent->ondisk;
1720 ondisk->count = 1;
1721 ondisk->parent = 0;
a56cb012 1722 ondisk->mirror_tid = leaf->ondisk->mirror_tid;
8cd0a023 1723 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1724 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1725 ondisk->elms[0].base.btype = leaf->ondisk->type;
8cd0a023 1726 ondisk->elms[0].internal.subtree_offset = leaf->node_offset;
47197d71 1727 ondisk->elms[1].base = hmp->root_btree_end;
fe7678ee 1728 /* ondisk->elms[1].base.btype = not used */
10a5d1ba 1729 hammer_modify_node_done(parent);
427e5fc6 1730 made_root = 1;
8cd0a023 1731 parent_index = 0; /* insertion point in parent */
427e5fc6
MD
1732 } else {
1733 made_root = 0;
8cd0a023
MD
1734 parent = cursor->parent;
1735 parent_index = cursor->parent_index;
427e5fc6 1736 }
427e5fc6 1737
df2ccbac
MD
1738 /*
1739 * Calculate a hint for the allocation of the new B-Tree leaf node.
1740 * For now just try to localize it within the same bigblock as
1741 * the current leaf.
1742 *
1743 * If the insertion point is at the end of the leaf we recognize a
1744 * likely append sequence of some sort (data, meta-data, inodes,
1745 * whatever). Set the hint to zero to allocate out of linear space
1746 * instead of trying to completely fill previously hinted space.
1747 *
1748 * This also sets the stage for recursive splits to localize using
1749 * the new space.
1750 */
1751 ondisk = leaf->ondisk;
1752 if (cursor->index == ondisk->count)
1753 hint = 0;
1754 else
1755 hint = leaf->node_offset;
1756
427e5fc6
MD
1757 /*
1758 * Split leaf into new_leaf at the split point. Select a separator
1759 * value in-between the two leafs but with a bent towards the right
1760 * leaf since comparisons use an 'elm >= separator' inequality.
1761 *
1762 * L L L L L L L L
1763 *
1764 * x x P x x
1765 * s S S s
1766 * / \
1767 * L L L L L L L L
1768 */
df2ccbac 1769 new_leaf = hammer_alloc_btree(cursor->trans, hint, &error);
427e5fc6 1770 if (new_leaf == NULL) {
8cd0a023
MD
1771 if (made_root) {
1772 hammer_unlock(&parent->lock);
36f82b23 1773 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1774 hammer_rel_node(parent);
1775 }
6a37e7e4 1776 goto done;
427e5fc6 1777 }
8cd0a023 1778 hammer_lock_ex(&new_leaf->lock);
427e5fc6
MD
1779
1780 /*
36f82b23
MD
1781 * Create the new node and copy the leaf elements from the split
1782 * point on to the new node.
427e5fc6 1783 */
36f82b23
MD
1784 hammer_modify_node_all(cursor->trans, leaf);
1785 hammer_modify_node_noundo(cursor->trans, new_leaf);
8cd0a023
MD
1786 ondisk = leaf->ondisk;
1787 elm = &ondisk->elms[split];
1788 bcopy(elm, &new_leaf->ondisk->elms[0], (ondisk->count - split) * esize);
1789 new_leaf->ondisk->count = ondisk->count - split;
1790 new_leaf->ondisk->parent = parent->node_offset;
1791 new_leaf->ondisk->type = HAMMER_BTREE_TYPE_LEAF;
a56cb012 1792 new_leaf->ondisk->mirror_tid = ondisk->mirror_tid;
8cd0a023 1793 KKASSERT(ondisk->type == new_leaf->ondisk->type);
10a5d1ba 1794 hammer_modify_node_done(new_leaf);
b3bad96f 1795 hammer_cursor_split_node(leaf, new_leaf, split);
427e5fc6
MD
1796
1797 /*
8cd0a023
MD
1798 * Cleanup the original node. Because this is a leaf node and
1799 * leaf nodes do not have a right-hand boundary, there
c0ade690
MD
1800 * aren't any special edge cases to clean up. We just fixup the
1801 * count.
427e5fc6 1802 */
c0ade690 1803 ondisk->count = split;
427e5fc6
MD
1804
1805 /*
1806 * Insert the separator into the parent, fixup the parent's
1807 * reference to the original node, and reference the new node.
1808 * The separator is P.
1809 *
1810 * Remember that base.count does not include the right-hand boundary.
1811 * We are copying parent_index+1 to parent_index+2, not +0 to +1.
1812 */
36f82b23 1813 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1814 ondisk = parent->ondisk;
36f82b23 1815 KKASSERT(split != 0);
d26d0ae9 1816 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1817 parent_elm = &ondisk->elms[parent_index+1];
d26d0ae9
MD
1818 bcopy(parent_elm, parent_elm + 1,
1819 (ondisk->count - parent_index) * esize);
eaeff70d 1820
47197d71 1821 hammer_make_separator(&elm[-1].base, &elm[0].base, &parent_elm->base);
fe7678ee 1822 parent_elm->internal.base.btype = new_leaf->ondisk->type;
8cd0a023 1823 parent_elm->internal.subtree_offset = new_leaf->node_offset;
a56cb012 1824 parent_elm->internal.mirror_tid = new_leaf->ondisk->mirror_tid;
b3deaf57 1825 mid_boundary = &parent_elm->base;
76376933 1826 ++ondisk->count;
10a5d1ba 1827 hammer_modify_node_done(parent);
b3bad96f 1828 hammer_cursor_inserted_element(parent, parent_index + 1);
427e5fc6 1829
fe7678ee 1830 /*
47197d71 1831 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1832 */
1833 if (made_root) {
47197d71
MD
1834 hammer_volume_t volume;
1835
1836 volume = hammer_get_root_volume(hmp, &error);
1837 KKASSERT(error == 0);
1838
e8599db1
MD
1839 hammer_modify_volume_field(cursor->trans, volume,
1840 vol0_btree_root);
47197d71 1841 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1842 hammer_modify_volume_done(volume);
8cd0a023
MD
1843 leaf->ondisk->parent = parent->node_offset;
1844 if (cursor->parent) {
1845 hammer_unlock(&cursor->parent->lock);
1846 hammer_rel_node(cursor->parent);
1847 }
1848 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1849 hammer_rel_volume(volume, 0);
427e5fc6 1850 }
10a5d1ba 1851 hammer_modify_node_done(leaf);
8cd0a023 1852
427e5fc6
MD
1853 /*
1854 * Ok, now adjust the cursor depending on which element the original
1855 * index was pointing at. If we are >= the split point the push node
1856 * is now in the new node.
1857 *
b3deaf57
MD
1858 * NOTE: If we are at the split point itself we need to select the
1859 * old or new node based on where key_beg's insertion point will be.
1860 * If we pick the wrong side the inserted element will wind up in
1861 * the wrong leaf node and outside that node's bounds.
427e5fc6 1862 */
b3deaf57
MD
1863 if (cursor->index > split ||
1864 (cursor->index == split &&
1865 hammer_btree_cmp(&cursor->key_beg, mid_boundary) >= 0)) {
8cd0a023 1866 cursor->parent_index = parent_index + 1;
427e5fc6 1867 cursor->index -= split;
8cd0a023
MD
1868 hammer_unlock(&cursor->node->lock);
1869 hammer_rel_node(cursor->node);
1870 cursor->node = new_leaf;
1871 } else {
1872 cursor->parent_index = parent_index;
1873 hammer_unlock(&new_leaf->lock);
1874 hammer_rel_node(new_leaf);
427e5fc6 1875 }
76376933
MD
1876
1877 /*
1878 * Fixup left and right bounds
1879 */
1880 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1881 cursor->left_bound = &parent_elm[0].internal.base;
1882 cursor->right_bound = &parent_elm[1].internal.base;
eaeff70d
MD
1883
1884 /*
47197d71 1885 * Assert that the bounds are correct.
eaeff70d 1886 */
b3deaf57
MD
1887 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1888 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1889 KKASSERT(hammer_btree_cmp(cursor->right_bound,
47197d71 1890 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
36f82b23
MD
1891 KKASSERT(hammer_btree_cmp(cursor->left_bound, &cursor->key_beg) <= 0);
1892 KKASSERT(hammer_btree_cmp(cursor->right_bound, &cursor->key_beg) > 0);
76376933 1893
6a37e7e4
MD
1894done:
1895 hammer_cursor_downgrade(cursor);
1896 return (error);
427e5fc6
MD
1897}
1898
adf01747
MD
1899#if 0
1900
32c90105
MD
1901/*
1902 * Recursively correct the right-hand boundary's create_tid to (tid) as
1903 * long as the rest of the key matches. We have to recurse upward in
1904 * the tree as well as down the left side of each parent's right node.
1905 *
1906 * Return EDEADLK if we were only partially successful, forcing the caller
1907 * to try again. The original cursor is not modified. This routine can
1908 * also fail with EDEADLK if it is forced to throw away a portion of its
1909 * record history.
1910 *
1911 * The caller must pass a downgraded cursor to us (otherwise we can't dup it).
1912 */
1913struct hammer_rhb {
1914 TAILQ_ENTRY(hammer_rhb) entry;
1915 hammer_node_t node;
1916 int index;
1917};
1918
1919TAILQ_HEAD(hammer_rhb_list, hammer_rhb);
1920
1921int
1922hammer_btree_correct_rhb(hammer_cursor_t cursor, hammer_tid_t tid)
1923{
bac808fe 1924 struct hammer_mount *hmp;
32c90105
MD
1925 struct hammer_rhb_list rhb_list;
1926 hammer_base_elm_t elm;
1927 hammer_node_t orig_node;
1928 struct hammer_rhb *rhb;
1929 int orig_index;
1930 int error;
1931
1932 TAILQ_INIT(&rhb_list);
bac808fe 1933 hmp = cursor->trans->hmp;
32c90105
MD
1934
1935 /*
1936 * Save our position so we can restore it on return. This also
1937 * gives us a stable 'elm'.
1938 */
1939 orig_node = cursor->node;
1940 hammer_ref_node(orig_node);
1941 hammer_lock_sh(&orig_node->lock);
1942 orig_index = cursor->index;
1943 elm = &orig_node->ondisk->elms[orig_index].base;
1944
1945 /*
1946 * Now build a list of parents going up, allocating a rhb
1947 * structure for each one.
1948 */
1949 while (cursor->parent) {
1950 /*
1951 * Stop if we no longer have any right-bounds to fix up
1952 */
1953 if (elm->obj_id != cursor->right_bound->obj_id ||
1954 elm->rec_type != cursor->right_bound->rec_type ||
1955 elm->key != cursor->right_bound->key) {
1956 break;
1957 }
1958
1959 /*
1960 * Stop if the right-hand bound's create_tid does not
47197d71 1961 * need to be corrected.
32c90105
MD
1962 */
1963 if (cursor->right_bound->create_tid >= tid)
1964 break;
1965
bac808fe 1966 rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO);
32c90105
MD
1967 rhb->node = cursor->parent;
1968 rhb->index = cursor->parent_index;
1969 hammer_ref_node(rhb->node);
1970 hammer_lock_sh(&rhb->node->lock);
1971 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
1972
1973 hammer_cursor_up(cursor);
1974 }
1975
1976 /*
1977 * now safely adjust the right hand bound for each rhb. This may
1978 * also require taking the right side of the tree and iterating down
1979 * ITS left side.
1980 */
1981 error = 0;
1982 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1983 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
32c90105
MD
1984 if (error)
1985 break;
1986 TAILQ_REMOVE(&rhb_list, rhb, entry);
1987 hammer_unlock(&rhb->node->lock);
1988 hammer_rel_node(rhb->node);
bac808fe 1989 kfree(rhb, hmp->m_misc);
32c90105
MD
1990
1991 switch (cursor->node->ondisk->type) {
1992 case HAMMER_BTREE_TYPE_INTERNAL:
1993 /*
1994 * Right-boundary for parent at internal node
1995 * is one element to the right of the element whos
1996 * right boundary needs adjusting. We must then
1997 * traverse down the left side correcting any left
1998 * bounds (which may now be too far to the left).
1999 */
2000 ++cursor->index;
2001 error = hammer_btree_correct_lhb(cursor, tid);
2002 break;
32c90105
MD
2003 default:
2004 panic("hammer_btree_correct_rhb(): Bad node type");
2005 error = EINVAL;
2006 break;
2007 }
2008 }
2009
2010 /*
2011 * Cleanup
2012 */
2013 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
2014 TAILQ_REMOVE(&rhb_list, rhb, entry);
2015 hammer_unlock(&rhb->node->lock);
2016 hammer_rel_node(rhb->node);
bac808fe 2017 kfree(rhb, hmp->m_misc);
32c90105
MD
2018 }
2019 error = hammer_cursor_seek(cursor, orig_node, orig_index);
2020 hammer_unlock(&orig_node->lock);
2021 hammer_rel_node(orig_node);
2022 return (error);
2023}
2024
2025/*
2026 * Similar to rhb (in fact, rhb calls lhb), but corrects the left hand
2027 * bound going downward starting at the current cursor position.
2028 *
2029 * This function does not restore the cursor after use.
2030 */
2031int
2032hammer_btree_correct_lhb(hammer_cursor_t cursor, hammer_tid_t tid)
2033{
2034 struct hammer_rhb_list rhb_list;
2035 hammer_base_elm_t elm;
2036 hammer_base_elm_t cmp;
2037 struct hammer_rhb *rhb;
bac808fe 2038 struct hammer_mount *hmp;
32c90105
MD
2039 int error;
2040
2041 TAILQ_INIT(&rhb_list);
bac808fe 2042 hmp = cursor->trans->hmp;
32c90105
MD
2043
2044 cmp = &cursor->node->ondisk->elms[cursor->index].base;
2045
2046 /*
2047 * Record the node and traverse down the left-hand side for all
2048 * matching records needing a boundary correction.
2049 */
2050 error = 0;
2051 for (;;) {
bac808fe 2052 rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO);
32c90105
MD
2053 rhb->node = cursor->node;
2054 rhb->index = cursor->index;
2055 hammer_ref_node(rhb->node);
2056 hammer_lock_sh(&rhb->node->lock);
2057 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
2058
2059 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
2060 /*
2061 * Nothing to traverse down if we are at the right
2062 * boundary of an internal node.
2063 */
2064 if (cursor->index == cursor->node->ondisk->count)
2065 break;
2066 } else {
2067 elm = &cursor->node->ondisk->elms[cursor->index].base;
2068 if (elm->btype == HAMMER_BTREE_TYPE_RECORD)
2069 break;
47197d71 2070 panic("Illegal leaf record type %02x", elm->btype);
32c90105
MD
2071 }
2072 error = hammer_cursor_down(cursor);
2073 if (error)
2074 break;
2075
2076 elm = &cursor->node->ondisk->elms[cursor->index].base;
2077 if (elm->obj_id != cmp->obj_id ||
2078 elm->rec_type != cmp->rec_type ||
2079 elm->key != cmp->key) {
2080 break;
2081 }
2082 if (elm->create_tid >= tid)
2083 break;
2084
2085 }
2086
2087 /*
2088 * Now we can safely adjust the left-hand boundary from the bottom-up.
2089 * The last element we remove from the list is the caller's right hand
2090 * boundary, which must also be adjusted.
2091 */
2092 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
2093 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
2094 if (error)
2095 break;
2096 TAILQ_REMOVE(&rhb_list, rhb, entry);
2097 hammer_unlock(&rhb->node->lock);
2098 hammer_rel_node(rhb->node);
bac808fe 2099 kfree(rhb, hmp->m_misc);
32c90105
MD
2100
2101 elm = &cursor->node->ondisk->elms[cursor->index].base;
2102 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
36f82b23 2103 hammer_modify_node(cursor->trans, cursor->node,
19619882
MD
2104 &elm->create_tid,
2105 sizeof(elm->create_tid));
32c90105 2106 elm->create_tid = tid;
10a5d1ba 2107 hammer_modify_node_done(cursor->node);
32c90105
MD
2108 } else {
2109 panic("hammer_btree_correct_lhb(): Bad element type");
2110 }
2111 }
2112
2113 /*
2114 * Cleanup
2115 */
2116 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
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 return (error);
2123}
2124
adf01747
MD
2125#endif
2126
427e5fc6 2127/*
f36a9737
MD
2128 * Attempt to remove the locked, empty or want-to-be-empty B-Tree node at
2129 * (cursor->node). Returns 0 on success, EDEADLK if we could not complete
2130 * the operation due to a deadlock, or some other error.
8cd0a023 2131 *
5c8d05e2
MD
2132 * This routine is initially called with an empty leaf and may be
2133 * recursively called with single-element internal nodes.
b3deaf57 2134 *
c82af904
MD
2135 * It should also be noted that when removing empty leaves we must be sure
2136 * to test and update mirror_tid because another thread may have deadlocked
5fa5c92f 2137 * against us (or someone) trying to propagate it up and cannot retry once
c82af904
MD
2138 * the node has been deleted.
2139 *
f36a9737
MD
2140 * On return the cursor may end up pointing to an internal node, suitable
2141 * for further iteration but not for an immediate insertion or deletion.
8cd0a023 2142 */
f36a9737 2143static int
46fe7ae1 2144btree_remove(hammer_cursor_t cursor)
8cd0a023
MD
2145{
2146 hammer_node_ondisk_t ondisk;
195c19a1 2147 hammer_btree_elm_t elm;
195c19a1 2148 hammer_node_t node;
8cd0a023 2149 hammer_node_t parent;
fe7678ee 2150 const int esize = sizeof(*elm);
8cd0a023 2151 int error;
8cd0a023 2152
fe7678ee
MD
2153 node = cursor->node;
2154
47197d71
MD
2155 /*
2156 * When deleting the root of the filesystem convert it to
2157 * an empty leaf node. Internal nodes cannot be empty.
2158 */
c82af904
MD
2159 ondisk = node->ondisk;
2160 if (ondisk->parent == 0) {
f36a9737 2161 KKASSERT(cursor->parent == NULL);
36f82b23 2162 hammer_modify_node_all(cursor->trans, node);
c82af904 2163 KKASSERT(ondisk == node->ondisk);
195c19a1
MD
2164 ondisk->type = HAMMER_BTREE_TYPE_LEAF;
2165 ondisk->count = 0;
10a5d1ba 2166 hammer_modify_node_done(node);
b3deaf57 2167 cursor->index = 0;
47197d71 2168 return(0);
8cd0a023
MD
2169 }
2170
c82af904 2171 parent = cursor->parent;
b3bad96f 2172 hammer_cursor_removed_node(node, parent, cursor->parent_index);
c82af904 2173
8cd0a023 2174 /*
f36a9737
MD
2175 * Attempt to remove the parent's reference to the child. If the
2176 * parent would become empty we have to recurse. If we fail we
2177 * leave the parent pointing to an empty leaf node.
5c8d05e2
MD
2178 *
2179 * We have to recurse successfully before we can delete the internal
2180 * node as it is illegal to have empty internal nodes. Even though
2181 * the operation may be aborted we must still fixup any unlocked
2182 * cursors as if we had deleted the element prior to recursing
2183 * (by calling hammer_cursor_deleted_element()) so those cursors
2184 * are properly forced up the chain by the recursion.
8cd0a023 2185 */
f36a9737
MD
2186 if (parent->ondisk->count == 1) {
2187 /*
2188 * This special cursor_up_locked() call leaves the original
2189 * node exclusively locked and referenced, leaves the
2190 * original parent locked (as the new node), and locks the
2191 * new parent. It can return EDEADLK.
2192 */
2193 error = hammer_cursor_up_locked(cursor);
2194 if (error == 0) {
5c8d05e2 2195 hammer_cursor_deleted_element(cursor->node, 0);
f36a9737
MD
2196 error = btree_remove(cursor);
2197 if (error == 0) {
2198 hammer_modify_node_all(cursor->trans, node);
2199 ondisk = node->ondisk;
2200 ondisk->type = HAMMER_BTREE_TYPE_DELETED;
2201 ondisk->count = 0;
2202 hammer_modify_node_done(node);
2203 hammer_flush_node(node);
2204 hammer_delete_node(cursor->trans, node);
2205 } else {
3214ade6
MD
2206 /*
2207 * Defer parent removal because we could not
2208 * get the lock, just let the leaf remain
2209 * empty.
2210 */
2211 /**/
f36a9737
MD
2212 }
2213 hammer_unlock(&node->lock);
2214 hammer_rel_node(node);
2215 } else {
3214ade6
MD
2216 /*
2217 * Defer parent removal because we could not
2218 * get the lock, just let the leaf remain
2219 * empty.
2220 */
2221 /**/
f36a9737
MD
2222 }
2223 } else {
2224 KKASSERT(parent->ondisk->count > 1);
6a37e7e4 2225
f36a9737
MD
2226 hammer_modify_node_all(cursor->trans, parent);
2227 ondisk = parent->ondisk;
2228 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
c82af904 2229
f36a9737
MD
2230 elm = &ondisk->elms[cursor->parent_index];
2231 KKASSERT(elm->internal.subtree_offset == node->node_offset);
2232 KKASSERT(ondisk->count > 0);
4c038e17
MD
2233
2234 /*
2235 * We must retain the highest mirror_tid. The deleted
2236 * range is now encompassed by the element to the left.
2237 * If we are already at the left edge the new left edge
2238 * inherits mirror_tid.
2239 *
2240 * Note that bounds of the parent to our parent may create
2241 * a gap to the left of our left-most node or to the right
2242 * of our right-most node. The gap is silently included
2243 * in the mirror_tid's area of effect from the point of view
2244 * of the scan.
2245 */
2246 if (cursor->parent_index) {
2247 if (elm[-1].internal.mirror_tid <
2248 elm[0].internal.mirror_tid) {
2249 elm[-1].internal.mirror_tid =
2250 elm[0].internal.mirror_tid;
2251 }
2252 } else {
2253 if (elm[1].internal.mirror_tid <
2254 elm[0].internal.mirror_tid) {
2255 elm[1].internal.mirror_tid =
2256 elm[0].internal.mirror_tid;
2257 }
2258 }
2259
2260 /*
2261 * Delete the subtree reference in the parent
2262 */
f36a9737
MD
2263 bcopy(&elm[1], &elm[0],
2264 (ondisk->count - cursor->parent_index) * esize);
2265 --ondisk->count;
10a5d1ba 2266 hammer_modify_node_done(parent);
6c1f89f4 2267 hammer_cursor_deleted_element(parent, cursor->parent_index);
f36a9737
MD
2268 hammer_flush_node(node);
2269 hammer_delete_node(cursor->trans, node);
6a37e7e4 2270
f36a9737
MD
2271 /*
2272 * cursor->node is invalid, cursor up to make the cursor
2273 * valid again.
2274 */
2275 error = hammer_cursor_up(cursor);
6a37e7e4 2276 }
f36a9737 2277 return (error);
6a37e7e4
MD
2278}
2279
602c6cb8
MD
2280/*
2281 * Propagate cursor->trans->tid up the B-Tree starting at the current
2282 * cursor position using pseudofs info gleaned from the passed inode.
2283 *
2284 * The passed inode has no relationship to the cursor position other
2285 * then being in the same pseudofs as the insertion or deletion we
2286 * are propagating the mirror_tid for.
2287 */
2288void
4c038e17
MD
2289hammer_btree_do_propagation(hammer_cursor_t cursor,
2290 hammer_pseudofs_inmem_t pfsm,
602c6cb8
MD
2291 hammer_btree_leaf_elm_t leaf)
2292{
adf01747
MD
2293 hammer_cursor_t ncursor;
2294 hammer_tid_t mirror_tid;
602c6cb8
MD
2295 int error;
2296
2297 /*
732a1697
MD
2298 * We do not propagate a mirror_tid if the filesystem was mounted
2299 * in no-mirror mode.
602c6cb8 2300 */
732a1697 2301 if (cursor->trans->hmp->master_id < 0)
602c6cb8 2302 return;
602c6cb8 2303
adf01747
MD
2304 /*
2305 * This is a bit of a hack because we cannot deadlock or return
2306 * EDEADLK here. The related operation has already completed and
2307 * we must propagate the mirror_tid now regardless.
2308 *
2309 * Generate a new cursor which inherits the original's locks and
2310 * unlock the original. Use the new cursor to propagate the
2311 * mirror_tid. Then clean up the new cursor and reacquire locks
2312 * on the original.
2313 *
2314 * hammer_dup_cursor() cannot dup locks. The dup inherits the
2315 * original's locks and the original is tracked and must be
2316 * re-locked.
2317 */
2318 mirror_tid = cursor->node->ondisk->mirror_tid;
a56cb012 2319 KKASSERT(mirror_tid != 0);
3f43fb33 2320 ncursor = hammer_push_cursor(cursor);
adf01747
MD
2321 error = hammer_btree_mirror_propagate(ncursor, mirror_tid);
2322 KKASSERT(error == 0);
3f43fb33 2323 hammer_pop_cursor(cursor, ncursor);
602c6cb8
MD
2324}
2325
2326
c82af904
MD
2327/*
2328 * Propagate a mirror TID update upwards through the B-Tree to the root.
2329 *
2330 * A locked internal node must be passed in. The node will remain locked
2331 * on return.
2332 *
2333 * This function syncs mirror_tid at the specified internal node's element,
2334 * adjusts the node's aggregation mirror_tid, and then recurses upwards.
2335 */
602c6cb8 2336static int
adf01747 2337hammer_btree_mirror_propagate(hammer_cursor_t cursor, hammer_tid_t mirror_tid)
c82af904
MD
2338{
2339 hammer_btree_internal_elm_t elm;
adf01747 2340 hammer_node_t node;
c82af904
MD
2341 int error;
2342
adf01747
MD
2343 for (;;) {
2344 error = hammer_cursor_up(cursor);
2345 if (error == 0)
2346 error = hammer_cursor_upgrade(cursor);
2347 while (error == EDEADLK) {
2348 hammer_recover_cursor(cursor);
2349 error = hammer_cursor_upgrade(cursor);
2350 }
2351 if (error)
2352 break;
2353 node = cursor->node;
2354 KKASSERT (node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
c82af904 2355
adf01747
MD
2356 /*
2357 * Adjust the node's element
2358 */
2359 elm = &node->ondisk->elms[cursor->index].internal;
2360 if (elm->mirror_tid >= mirror_tid)
2361 break;
2362 hammer_modify_node(cursor->trans, node, &elm->mirror_tid,
2363 sizeof(elm->mirror_tid));
2364 elm->mirror_tid = mirror_tid;
2365 hammer_modify_node_done(node);
02325004
MD
2366 if (hammer_debug_general & 0x0002) {
2367 kprintf("mirror_propagate: propagate "
2368 "%016llx @%016llx:%d\n",
2369 mirror_tid, node->node_offset, cursor->index);
2370 }
2371
c82af904 2372
adf01747
MD
2373 /*
2374 * Adjust the node's mirror_tid aggregator
2375 */
2376 if (node->ondisk->mirror_tid >= mirror_tid)
2377 return(0);
2378 hammer_modify_node_field(cursor->trans, node, mirror_tid);
2379 node->ondisk->mirror_tid = mirror_tid;
2380 hammer_modify_node_done(node);
02325004
MD
2381 if (hammer_debug_general & 0x0002) {
2382 kprintf("mirror_propagate: propagate "
2383 "%016llx @%016llx\n",
2384 mirror_tid, node->node_offset);
2385 }
c82af904 2386 }
adf01747
MD
2387 if (error == ENOENT)
2388 error = 0;
c82af904
MD
2389 return(error);
2390}
2391
2392hammer_node_t
82010f9f
MD
2393hammer_btree_get_parent(hammer_transaction_t trans, hammer_node_t node,
2394 int *parent_indexp, int *errorp, int try_exclusive)
c82af904
MD
2395{
2396 hammer_node_t parent;
2397 hammer_btree_elm_t elm;
2398 int i;
2399
2400 /*
2401 * Get the node
2402 */
82010f9f 2403 parent = hammer_get_node(trans, node->ondisk->parent, 0, errorp);
c82af904
MD
2404 if (*errorp) {
2405 KKASSERT(parent == NULL);
2406 return(NULL);
2407 }
2408 KKASSERT ((parent->flags & HAMMER_NODE_DELETED) == 0);
2409
2410 /*
2411 * Lock the node
2412 */
2413 if (try_exclusive) {
2414 if (hammer_lock_ex_try(&parent->lock)) {
2415 hammer_rel_node(parent);
2416 *errorp = EDEADLK;
2417 return(NULL);
2418 }
2419 } else {
2420 hammer_lock_sh(&parent->lock);
2421 }
2422
2423 /*
2424 * Figure out which element in the parent is pointing to the
2425 * child.
2426 */
2427 if (node->ondisk->count) {
2428 i = hammer_btree_search_node(&node->ondisk->elms[0].base,
2429 parent->ondisk);
2430 } else {
2431 i = 0;
2432 }
2433 while (i < parent->ondisk->count) {
2434 elm = &parent->ondisk->elms[i];
2435 if (elm->internal.subtree_offset == node->node_offset)
2436 break;
2437 ++i;
2438 }
2439 if (i == parent->ondisk->count) {
2440 hammer_unlock(&parent->lock);
2441 panic("Bad B-Tree link: parent %p node %p\n", parent, node);
2442 }
2443 *parent_indexp = i;
2444 KKASSERT(*errorp == 0);
2445 return(parent);
2446}
2447
7f7c1f84 2448/*
fe7678ee
MD
2449 * The element (elm) has been moved to a new internal node (node).
2450 *
2451 * If the element represents a pointer to an internal node that node's
2452 * parent must be adjusted to the element's new location.
2453 *
6a37e7e4 2454 * XXX deadlock potential here with our exclusive locks
7f7c1f84 2455 */
7f7c1f84 2456int
36f82b23
MD
2457btree_set_parent(hammer_transaction_t trans, hammer_node_t node,
2458 hammer_btree_elm_t elm)
7f7c1f84 2459{
7f7c1f84
MD
2460 hammer_node_t child;
2461 int error;
2462
2463 error = 0;
2464
fe7678ee 2465 switch(elm->base.btype) {
7f7c1f84 2466 case HAMMER_BTREE_TYPE_INTERNAL:
fe7678ee 2467 case HAMMER_BTREE_TYPE_LEAF:
82010f9f 2468 child = hammer_get_node(trans, elm->internal.subtree_offset,
19619882 2469 0, &error);
7f7c1f84 2470 if (error == 0) {
c9b9e29d 2471 hammer_modify_node_field(trans, child, parent);
7f7c1f84 2472 child->ondisk->parent = node->node_offset;
10a5d1ba 2473 hammer_modify_node_done(child);
7f7c1f84
MD
2474 hammer_rel_node(child);
2475 }
2476 break;
7f7c1f84 2477 default:
fe7678ee 2478 break;
7f7c1f84
MD
2479 }
2480 return(error);
2481}
2482
1775b6a0
MD
2483/*
2484 * Initialize the root of a recursive B-Tree node lock list structure.
2485 */
2486void
2487hammer_node_lock_init(hammer_node_lock_t parent, hammer_node_t node)
2488{
2489 TAILQ_INIT(&parent->list);
2490 parent->parent = NULL;
2491 parent->node = node;
2492 parent->index = -1;
2493 parent->count = node->ondisk->count;
2494 parent->copy = NULL;
2495 parent->flags = 0;
2496}
2497
b33e2cc0
MD
2498/*
2499 * Exclusively lock all the children of node. This is used by the split
2500 * code to prevent anyone from accessing the children of a cursor node
2501 * while we fix-up its parent offset.
2502 *
2503 * If we don't lock the children we can really mess up cursors which block
2504 * trying to cursor-up into our node.
2505 *
b33e2cc0
MD
2506 * On failure EDEADLK (or some other error) is returned. If a deadlock
2507 * error is returned the cursor is adjusted to block on termination.
1775b6a0
MD
2508 *
2509 * The caller is responsible for managing parent->node, the root's node
2510 * is usually aliased from a cursor.
b33e2cc0
MD
2511 */
2512int
1775b6a0
MD
2513hammer_btree_lock_children(hammer_cursor_t cursor, int depth,
2514 hammer_node_lock_t parent)
b33e2cc0
MD
2515{
2516 hammer_node_t node;
1775b6a0 2517 hammer_node_lock_t item;
b33e2cc0
MD
2518 hammer_node_ondisk_t ondisk;
2519 hammer_btree_elm_t elm;
b33e2cc0 2520 hammer_node_t child;
bac808fe 2521 struct hammer_mount *hmp;
b33e2cc0
MD
2522 int error;
2523 int i;
2524
1775b6a0 2525 node = parent->node;
b33e2cc0
MD
2526 ondisk = node->ondisk;
2527 error = 0;
bac808fe 2528 hmp = cursor->trans->hmp;
7bc5b8c2
MD
2529
2530 /*
2531 * We really do not want to block on I/O with exclusive locks held,
1775b6a0
MD
2532 * pre-get the children before trying to lock the mess. This is
2533 * only done one-level deep for now.
7bc5b8c2
MD
2534 */
2535 for (i = 0; i < ondisk->count; ++i) {
cb51be26 2536 ++hammer_stats_btree_elements;
7bc5b8c2
MD
2537 elm = &ondisk->elms[i];
2538 if (elm->base.btype != HAMMER_BTREE_TYPE_LEAF &&
2539 elm->base.btype != HAMMER_BTREE_TYPE_INTERNAL) {
2540 continue;
2541 }
82010f9f 2542 child = hammer_get_node(cursor->trans,
7bc5b8c2
MD
2543 elm->internal.subtree_offset,
2544 0, &error);
2545 if (child)
2546 hammer_rel_node(child);
2547 }
2548
2549 /*
2550 * Do it for real
2551 */
b33e2cc0 2552 for (i = 0; error == 0 && i < ondisk->count; ++i) {
cb51be26 2553 ++hammer_stats_btree_elements;
b33e2cc0
MD
2554 elm = &ondisk->elms[i];
2555
b33e2cc0
MD
2556 switch(elm->base.btype) {
2557 case HAMMER_BTREE_TYPE_INTERNAL:
2558 case HAMMER_BTREE_TYPE_LEAF:
f36a9737 2559 KKASSERT(elm->internal.subtree_offset != 0);
82010f9f 2560 child = hammer_get_node(cursor->trans,
b33e2cc0 2561 elm->internal.subtree_offset,
19619882 2562 0, &error);
b33e2cc0 2563 break;
b33e2cc0 2564 default:
47197d71 2565 child = NULL;
b33e2cc0
MD
2566 break;
2567 }
2568 if (child) {
2569 if (hammer_lock_ex_try(&child->lock) != 0) {
2570 if (cursor->deadlk_node == NULL) {
1ff9f58e 2571 cursor->deadlk_node = child;
b33e2cc0
MD
2572 hammer_ref_node(cursor->deadlk_node);
2573 }
2574 error = EDEADLK;
a84a197d 2575 hammer_rel_node(child);
b33e2cc0 2576 } else {
1775b6a0
MD
2577 item = kmalloc(sizeof(*item), hmp->m_misc,
2578 M_WAITOK|M_ZERO);
2579 TAILQ_INSERT_TAIL(&parent->list, item, entry);
2580 TAILQ_INIT(&item->list);
2581 item->parent = parent;
b33e2cc0 2582 item->node = child;
1775b6a0
MD
2583 item->index = i;
2584 item->count = child->ondisk->count;
2585
2586 /*
2587 * Recurse (used by the rebalancing code)
2588 */
2589 if (depth > 1 && elm->base.btype == HAMMER_BTREE_TYPE_INTERNAL) {
2590 error = hammer_btree_lock_children(
2591 cursor,
2592 depth - 1,
2593 item);
2594 }
b33e2cc0
MD
2595 }
2596 }
2597 }
2598 if (error)
1775b6a0 2599 hammer_btree_unlock_children(cursor, parent);
b33e2cc0
MD
2600 return(error);
2601}
2602
1775b6a0
MD
2603/*
2604 * Create an in-memory copy of all B-Tree nodes listed, recursively,
2605 * including the parent.
2606 */
2607void
2608hammer_btree_lock_copy(hammer_cursor_t cursor, hammer_node_lock_t parent)
2609{
2610 hammer_mount_t hmp = cursor->trans->hmp;
2611 hammer_node_lock_t item;
2612
2613 if (parent->copy == NULL) {
2614 parent->copy = kmalloc(sizeof(*parent->copy), hmp->m_misc,
2615 M_WAITOK);
2616 *parent->copy = *parent->node->ondisk;
2617 }
2618 TAILQ_FOREACH(item, &parent->list, entry) {
2619 hammer_btree_lock_copy(cursor, item);
2620 }
2621}
b33e2cc0
MD
2622
2623/*
1775b6a0 2624 * Recursively sync modified copies to the media.
b33e2cc0 2625 */
7ddc70d1 2626int
1775b6a0 2627hammer_btree_sync_copy(hammer_cursor_t cursor, hammer_node_lock_t parent)
b33e2cc0 2628{
1775b6a0 2629 hammer_node_lock_t item;
7ddc70d1 2630 int count = 0;
1775b6a0
MD
2631
2632 if (parent->flags & HAMMER_NODE_LOCK_UPDATED) {
7ddc70d1 2633 ++count;
1775b6a0
MD
2634 hammer_modify_node_all(cursor->trans, parent->node);
2635 *parent->node->ondisk = *parent->copy;
2636 hammer_modify_node_done(parent->node);
2637 if (parent->copy->type == HAMMER_BTREE_TYPE_DELETED) {
2638 hammer_flush_node(parent->node);
2639 hammer_delete_node(cursor->trans, parent->node);
2640 }
2641 }
2642 TAILQ_FOREACH(item, &parent->list, entry) {
7ddc70d1 2643 count += hammer_btree_sync_copy(cursor, item);
1775b6a0 2644 }
7ddc70d1 2645 return(count);
1775b6a0 2646}
b33e2cc0 2647
1775b6a0
MD
2648/*
2649 * Release previously obtained node locks. The caller is responsible for
2650 * cleaning up parent->node itself (its usually just aliased from a cursor),
2651 * but this function will take care of the copies.
2652 */
2653void
2654hammer_btree_unlock_children(hammer_cursor_t cursor, hammer_node_lock_t parent)
2655{
2656 hammer_node_lock_t item;
2657
2658 if (parent->copy) {
2659 kfree(parent->copy, cursor->trans->hmp->m_misc);
2660 parent->copy = NULL; /* safety */
2661 }
2662 while ((item = TAILQ_FIRST(&parent->list)) != NULL) {
2663 TAILQ_REMOVE(&parent->list, item, entry);
2664 hammer_btree_unlock_children(cursor, item);
b33e2cc0
MD
2665 hammer_unlock(&item->node->lock);
2666 hammer_rel_node(item->node);
bac808fe 2667 kfree(item, cursor->trans->hmp->m_misc);
b33e2cc0
MD
2668 }
2669}
2670
8cd0a023
MD
2671/************************************************************************
2672 * MISCELLANIOUS SUPPORT *
2673 ************************************************************************/
2674
2675/*
d26d0ae9 2676 * Compare two B-Tree elements, return -N, 0, or +N (e.g. similar to strcmp).
8cd0a023 2677 *
d113fda1 2678 * Note that for this particular function a return value of -1, 0, or +1
9582c7da 2679 * can denote a match if create_tid is otherwise discounted. A create_tid
d5530d22 2680 * of zero is considered to be 'infinity' in comparisons.
d113fda1 2681 *
8cd0a023 2682 * See also hammer_rec_rb_compare() and hammer_rec_cmp() in hammer_object.c.
8cd0a023
MD
2683 */
2684int
2685hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2)
2686{
2f85fa4d
MD
2687 if (key1->localization < key2->localization)
2688 return(-5);
2689 if (key1->localization > key2->localization)
2690 return(5);
2691
d26d0ae9
MD
2692 if (key1->obj_id < key2->obj_id)
2693 return(-4);
2694 if (key1->obj_id > key2->obj_id)
2695 return(4);
8cd0a023 2696
d26d0ae9
MD
2697 if (key1->rec_type < key2->rec_type)
2698 return(-3);
2699 if (key1->rec_type > key2->rec_type)
2700 return(3);
8cd0a023 2701
8cd0a023
MD
2702 if (key1->key < key2->key)
2703 return(-2);
2704 if (key1->key > key2->key)
2705 return(2);
d113fda1 2706
d5530d22 2707 /*
9582c7da
MD
2708 * A create_tid of zero indicates a record which is undeletable
2709 * and must be considered to have a value of positive infinity.
d5530d22 2710 */
9582c7da
MD
2711 if (key1->create_tid == 0) {
2712 if (key2->create_tid == 0)
d5530d22
MD
2713 return(0);
2714 return(1);
2715 }
9582c7da 2716 if (key2->create_tid == 0)
d5530d22 2717 return(-1);
9582c7da 2718 if (key1->create_tid < key2->create_tid)
d113fda1 2719 return(-1);
9582c7da 2720 if (key1->create_tid > key2->create_tid)
d113fda1 2721 return(1);
8cd0a023
MD
2722 return(0);
2723}
2724
c0ade690 2725/*
d5530d22
MD
2726 * Test a timestamp against an element to determine whether the
2727 * element is visible. A timestamp of 0 means 'infinity'.
c0ade690
MD
2728 */
2729int
d5530d22 2730hammer_btree_chkts(hammer_tid_t asof, hammer_base_elm_t base)
c0ade690 2731{
d5530d22
MD
2732 if (asof == 0) {
2733 if (base->delete_tid)
2734 return(1);
2735 return(0);
2736 }
2737 if (asof < base->create_tid)
d26d0ae9 2738 return(-1);
d5530d22 2739 if (base->delete_tid && asof >= base->delete_tid)
d26d0ae9 2740 return(1);
c0ade690
MD
2741 return(0);
2742}
2743
8cd0a023
MD
2744/*
2745 * Create a separator half way inbetween key1 and key2. For fields just
d5530d22
MD
2746 * one unit apart, the separator will match key2. key1 is on the left-hand
2747 * side and key2 is on the right-hand side.
8cd0a023 2748 *
9391cded 2749 * key2 must be >= the separator. It is ok for the separator to match key2.
36f82b23 2750 *
9391cded
MD
2751 * NOTE: Even if key1 does not match key2, the separator may wind up matching
2752 * key2.
2753 *
2754 * NOTE: It might be beneficial to just scrap this whole mess and just
2755 * set the separator to key2.
8cd0a023
MD
2756 */
2757#define MAKE_SEPARATOR(key1, key2, dest, field) \
2758 dest->field = key1->field + ((key2->field - key1->field + 1) >> 1);
2759
2760static void
2761hammer_make_separator(hammer_base_elm_t key1, hammer_base_elm_t key2,
2762 hammer_base_elm_t dest)
2763{
2764 bzero(dest, sizeof(*dest));
d5530d22 2765
9391cded
MD
2766 dest->rec_type = key2->rec_type;
2767 dest->key = key2->key;
2f85fa4d 2768 dest->obj_id = key2->obj_id;
9391cded
MD
2769 dest->create_tid = key2->create_tid;
2770
2f85fa4d
MD
2771 MAKE_SEPARATOR(key1, key2, dest, localization);
2772 if (key1->localization == key2->localization) {
2773 MAKE_SEPARATOR(key1, key2, dest, obj_id);
2774 if (key1->obj_id == key2->obj_id) {
2775 MAKE_SEPARATOR(key1, key2, dest, rec_type);
2776 if (key1->rec_type == key2->rec_type) {
2777 MAKE_SEPARATOR(key1, key2, dest, key);
2778 /*
2779 * Don't bother creating a separator for
2780 * create_tid, which also conveniently avoids
2781 * having to handle the create_tid == 0
2782 * (infinity) case. Just leave create_tid
2783 * set to key2.
2784 *
2785 * Worst case, dest matches key2 exactly,
2786 * which is acceptable.
2787 */
2788 }
d5530d22 2789 }
d113fda1 2790 }
8cd0a023
MD
2791}
2792
2793#undef MAKE_SEPARATOR
2794
2795/*
2796 * Return whether a generic internal or leaf node is full
2797 */
2798static int
2799btree_node_is_full(hammer_node_ondisk_t node)
2800{
2801 switch(node->type) {
2802 case HAMMER_BTREE_TYPE_INTERNAL:
2803 if (node->count == HAMMER_BTREE_INT_ELMS)
2804 return(1);
2805 break;
2806 case HAMMER_BTREE_TYPE_LEAF:
2807 if (node->count == HAMMER_BTREE_LEAF_ELMS)
2808 return(1);
2809 break;
2810 default:
2811 panic("illegal btree subtype");
2812 }
2813 return(0);
2814}
9944ae54 2815
8cd0a023
MD
2816#if 0
2817static int
2818btree_max_elements(u_int8_t type)
2819{
2820 if (type == HAMMER_BTREE_TYPE_LEAF)
2821 return(HAMMER_BTREE_LEAF_ELMS);
2822 if (type == HAMMER_BTREE_TYPE_INTERNAL)
2823 return(HAMMER_BTREE_INT_ELMS);
2824 panic("btree_max_elements: bad type %d\n", type);
2825}
2826#endif
2827
c0ade690
MD
2828void
2829hammer_print_btree_node(hammer_node_ondisk_t ondisk)
2830{
2831 hammer_btree_elm_t elm;
2832 int i;
2833
47197d71 2834 kprintf("node %p count=%d parent=%016llx type=%c\n",
c0ade690
MD
2835 ondisk, ondisk->count, ondisk->parent, ondisk->type);
2836
2837 /*
2838 * Dump both boundary elements if an internal node
2839 */
2840 if (ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
2841 for (i = 0; i <= ondisk->count; ++i) {
2842 elm = &ondisk->elms[i];
2843 hammer_print_btree_elm(elm, ondisk->type, i);
2844 }
2845 } else {
2846 for (i = 0; i < ondisk->count; ++i) {
2847 elm = &ondisk->elms[i];
2848 hammer_print_btree_elm(elm, ondisk->type, i);
2849 }
2850 }
2851}
2852
2853void
2854hammer_print_btree_elm(hammer_btree_elm_t elm, u_int8_t type, int i)
2855{
2856 kprintf(" %2d", i);
7dc57964 2857 kprintf("\tobj_id = %016llx\n", elm->base.obj_id);
c0ade690
MD
2858 kprintf("\tkey = %016llx\n", elm->base.key);
2859 kprintf("\tcreate_tid = %016llx\n", elm->base.create_tid);
2860 kprintf("\tdelete_tid = %016llx\n", elm->base.delete_tid);
2861 kprintf("\trec_type = %04x\n", elm->base.rec_type);
2862 kprintf("\tobj_type = %02x\n", elm->base.obj_type);
fe7678ee
MD
2863 kprintf("\tbtype = %02x (%c)\n",
2864 elm->base.btype,
2865 (elm->base.btype ? elm->base.btype : '?'));
2f85fa4d 2866 kprintf("\tlocalization = %02x\n", elm->base.localization);
fe7678ee
MD
2867
2868 switch(type) {
2869 case HAMMER_BTREE_TYPE_INTERNAL:
47197d71 2870 kprintf("\tsubtree_off = %016llx\n",
fe7678ee
MD
2871 elm->internal.subtree_offset);
2872 break;
fe7678ee 2873 case HAMMER_BTREE_TYPE_RECORD:
47197d71 2874 kprintf("\tdata_offset = %016llx\n", elm->leaf.data_offset);
c0ade690
MD
2875 kprintf("\tdata_len = %08x\n", elm->leaf.data_len);
2876 kprintf("\tdata_crc = %08x\n", elm->leaf.data_crc);
fe7678ee 2877 break;
c0ade690
MD
2878 }
2879}