HAMMER VFS - Handle critical I/O errors without panicing
[dragonfly.git] / sys / vfs / hammer / hammer_btree.c
CommitLineData
427e5fc6 1/*
b84de5af 2 * Copyright (c) 2007-2008 The DragonFly Project. All rights reserved.
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3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
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
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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);
adf01747
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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;
3e583440 120 hammer_mount_t hmp;
1d4077f7 121 int error = 0;
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122 int r;
123 int s;
124
125 /*
8cd0a023 126 * Skip past the current record
66325755 127 */
3e583440 128 hmp = cursor->trans->hmp;
8cd0a023 129 node = cursor->node->ondisk;
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130 if (node == NULL)
131 return(ENOENT);
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132 if (cursor->index < node->count &&
133 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
66325755 134 ++cursor->index;
c0ade690 135 }
66325755 136
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137 /*
138 * HAMMER can wind up being cpu-bound.
139 */
140 if (++hmp->check_yield > hammer_yield_check) {
141 hmp->check_yield = 0;
142 lwkt_user_yield();
143 }
144
145
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146 /*
147 * Loop until an element is found or we are done.
148 */
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149 for (;;) {
150 /*
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151 * We iterate up the tree and then index over one element
152 * while we are at the last element in the current node.
153 *
47197d71 154 * If we are at the root of the filesystem, cursor_up
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155 * returns ENOENT.
156 *
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157 * XXX this could be optimized by storing the information in
158 * the parent reference.
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159 *
160 * XXX we can lose the node lock temporarily, this could mess
161 * up our scan.
66325755 162 */
47637bff 163 ++hammer_stats_btree_iterations;
3e583440 164 hammer_flusher_clean_loose_ios(hmp);
77fec802 165
8cd0a023 166 if (cursor->index == node->count) {
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167 if (hammer_debug_btree) {
168 kprintf("BRACKETU %016llx[%d] -> %016llx[%d] (td=%p)\n",
973c11b9 169 (long long)cursor->node->node_offset,
a84a197d 170 cursor->index,
973c11b9 171 (long long)(cursor->parent ? cursor->parent->node_offset : -1),
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172 cursor->parent_index,
173 curthread);
174 }
175 KKASSERT(cursor->parent == NULL || cursor->parent->ondisk->elms[cursor->parent_index].internal.subtree_offset == cursor->node->node_offset);
6a37e7e4 176 error = hammer_cursor_up(cursor);
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177 if (error)
178 break;
46fe7ae1 179 /* reload stale pointer */
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180 node = cursor->node->ondisk;
181 KKASSERT(cursor->index != node->count);
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182
183 /*
184 * If we are reblocking we want to return internal
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185 * nodes. Note that the internal node will be
186 * returned multiple times, on each upward recursion
187 * from its children. The caller selects which
188 * revisit it cares about (usually first or last only).
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189 */
190 if (cursor->flags & HAMMER_CURSOR_REBLOCKING) {
191 cursor->flags |= HAMMER_CURSOR_ATEDISK;
192 return(0);
193 }
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194 ++cursor->index;
195 continue;
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196 }
197
198 /*
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199 * Check internal or leaf element. Determine if the record
200 * at the cursor has gone beyond the end of our range.
66325755 201 *
47197d71 202 * We recurse down through internal nodes.
66325755 203 */
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204 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
205 elm = &node->elms[cursor->index];
c82af904 206
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207 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
208 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
b3deaf57 209 if (hammer_debug_btree) {
2f85fa4d 210 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d (td=%p)\n",
973c11b9 211 (long long)cursor->node->node_offset,
eaeff70d 212 cursor->index,
973c11b9 213 (long long)elm[0].internal.base.obj_id,
b3deaf57 214 elm[0].internal.base.rec_type,
973c11b9 215 (long long)elm[0].internal.base.key,
2f85fa4d 216 elm[0].internal.base.localization,
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217 r,
218 curthread
b3deaf57 219 );
2f85fa4d 220 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
973c11b9 221 (long long)cursor->node->node_offset,
eaeff70d 222 cursor->index + 1,
973c11b9 223 (long long)elm[1].internal.base.obj_id,
b3deaf57 224 elm[1].internal.base.rec_type,
973c11b9 225 (long long)elm[1].internal.base.key,
2f85fa4d 226 elm[1].internal.base.localization,
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227 s
228 );
229 }
230
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231 if (r < 0) {
232 error = ENOENT;
233 break;
66325755 234 }
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235 if (r == 0 && (cursor->flags &
236 HAMMER_CURSOR_END_INCLUSIVE) == 0) {
d26d0ae9 237 error = ENOENT;
8cd0a023 238 break;
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239 }
240 KKASSERT(s <= 0);
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241
242 /*
f36a9737 243 * Better not be zero
6a37e7e4 244 */
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245 KKASSERT(elm->internal.subtree_offset != 0);
246
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247 /*
248 * If running the mirror filter see if we can skip
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249 * one or more entire sub-trees. If we can we
250 * return the internal mode and the caller processes
251 * the skipped range (see mirror_read)
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252 */
253 if (cursor->flags & HAMMER_CURSOR_MIRROR_FILTERED) {
254 if (elm->internal.mirror_tid <
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255 cursor->cmirror->mirror_tid) {
256 hammer_cursor_mirror_filter(cursor);
257 return(0);
c82af904
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258 }
259 }
260
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261 error = hammer_cursor_down(cursor);
262 if (error)
263 break;
264 KKASSERT(cursor->index == 0);
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265 /* reload stale pointer */
266 node = cursor->node->ondisk;
fe7678ee 267 continue;
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268 } else {
269 elm = &node->elms[cursor->index];
270 r = hammer_btree_cmp(&cursor->key_end, &elm->base);
b3deaf57 271 if (hammer_debug_btree) {
2f85fa4d 272 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
973c11b9 273 (long long)cursor->node->node_offset,
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274 cursor->index,
275 (elm[0].leaf.base.btype ?
276 elm[0].leaf.base.btype : '?'),
973c11b9 277 (long long)elm[0].leaf.base.obj_id,
b3deaf57 278 elm[0].leaf.base.rec_type,
973c11b9 279 (long long)elm[0].leaf.base.key,
2f85fa4d 280 elm[0].leaf.base.localization,
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281 r
282 );
283 }
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284 if (r < 0) {
285 error = ENOENT;
286 break;
287 }
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288
289 /*
290 * We support both end-inclusive and
291 * end-exclusive searches.
292 */
293 if (r == 0 &&
294 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
295 error = ENOENT;
296 break;
297 }
298
fe7678ee
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299 switch(elm->leaf.base.btype) {
300 case HAMMER_BTREE_TYPE_RECORD:
301 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
302 hammer_btree_chkts(cursor->asof, &elm->base)) {
303 ++cursor->index;
304 continue;
305 }
1d4077f7 306 error = 0;
fe7678ee 307 break;
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308 default:
309 error = EINVAL;
310 break;
d26d0ae9 311 }
fe7678ee
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312 if (error)
313 break;
66325755 314 }
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315 /*
316 * node pointer invalid after loop
317 */
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318
319 /*
d26d0ae9 320 * Return entry
66325755 321 */
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322 if (hammer_debug_btree) {
323 int i = cursor->index;
324 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 325 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
b3deaf57 326 cursor->node, i,
973c11b9 327 (long long)elm->internal.base.obj_id,
b3deaf57 328 elm->internal.base.rec_type,
973c11b9 329 (long long)elm->internal.base.key,
2f85fa4d 330 elm->internal.base.localization
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331 );
332 }
d26d0ae9 333 return(0);
427e5fc6 334 }
66325755 335 return(error);
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336}
337
4c038e17
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338/*
339 * We hit an internal element that we could skip as part of a mirroring
340 * scan. Calculate the entire range being skipped.
341 *
342 * It is important to include any gaps between the parent's left_bound
343 * and the node's left_bound, and same goes for the right side.
344 */
345static void
346hammer_cursor_mirror_filter(hammer_cursor_t cursor)
347{
348 struct hammer_cmirror *cmirror;
349 hammer_node_ondisk_t ondisk;
350 hammer_btree_elm_t elm;
351
352 ondisk = cursor->node->ondisk;
353 cmirror = cursor->cmirror;
354
355 /*
356 * Calculate the skipped range
357 */
358 elm = &ondisk->elms[cursor->index];
359 if (cursor->index == 0)
360 cmirror->skip_beg = *cursor->left_bound;
361 else
362 cmirror->skip_beg = elm->internal.base;
363 while (cursor->index < ondisk->count) {
364 if (elm->internal.mirror_tid >= cmirror->mirror_tid)
365 break;
366 ++cursor->index;
367 ++elm;
368 }
369 if (cursor->index == ondisk->count)
370 cmirror->skip_end = *cursor->right_bound;
371 else
372 cmirror->skip_end = elm->internal.base;
373
374 /*
375 * clip the returned result.
376 */
377 if (hammer_btree_cmp(&cmirror->skip_beg, &cursor->key_beg) < 0)
378 cmirror->skip_beg = cursor->key_beg;
379 if (hammer_btree_cmp(&cmirror->skip_end, &cursor->key_end) > 0)
380 cmirror->skip_end = cursor->key_end;
381}
382
32c90105
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383/*
384 * Iterate in the reverse direction. This is used by the pruning code to
385 * avoid overlapping records.
386 */
387int
388hammer_btree_iterate_reverse(hammer_cursor_t cursor)
389{
390 hammer_node_ondisk_t node;
391 hammer_btree_elm_t elm;
f75df937 392 int error = 0;
32c90105
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393 int r;
394 int s;
395
4c038e17
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396 /* mirror filtering not supported for reverse iteration */
397 KKASSERT ((cursor->flags & HAMMER_CURSOR_MIRROR_FILTERED) == 0);
398
32c90105
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399 /*
400 * Skip past the current record. For various reasons the cursor
401 * may end up set to -1 or set to point at the end of the current
402 * node. These cases must be addressed.
403 */
404 node = cursor->node->ondisk;
405 if (node == NULL)
406 return(ENOENT);
407 if (cursor->index != -1 &&
408 (cursor->flags & HAMMER_CURSOR_ATEDISK)) {
409 --cursor->index;
410 }
411 if (cursor->index == cursor->node->ondisk->count)
412 --cursor->index;
413
414 /*
415 * Loop until an element is found or we are done.
416 */
417 for (;;) {
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418 ++hammer_stats_btree_iterations;
419 hammer_flusher_clean_loose_ios(cursor->trans->hmp);
420
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421 /*
422 * We iterate up the tree and then index over one element
423 * while we are at the last element in the current node.
32c90105
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424 */
425 if (cursor->index == -1) {
426 error = hammer_cursor_up(cursor);
427 if (error) {
428 cursor->index = 0; /* sanity */
429 break;
430 }
431 /* reload stale pointer */
432 node = cursor->node->ondisk;
433 KKASSERT(cursor->index != node->count);
434 --cursor->index;
435 continue;
436 }
437
438 /*
439 * Check internal or leaf element. Determine if the record
440 * at the cursor has gone beyond the end of our range.
441 *
47197d71 442 * We recurse down through internal nodes.
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443 */
444 KKASSERT(cursor->index != node->count);
445 if (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
446 elm = &node->elms[cursor->index];
447 r = hammer_btree_cmp(&cursor->key_end, &elm[0].base);
448 s = hammer_btree_cmp(&cursor->key_beg, &elm[1].base);
449 if (hammer_debug_btree) {
2f85fa4d 450 kprintf("BRACKETL %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
973c11b9 451 (long long)cursor->node->node_offset,
32c90105 452 cursor->index,
973c11b9 453 (long long)elm[0].internal.base.obj_id,
32c90105 454 elm[0].internal.base.rec_type,
973c11b9 455 (long long)elm[0].internal.base.key,
2f85fa4d 456 elm[0].internal.base.localization,
32c90105
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457 r
458 );
2f85fa4d 459 kprintf("BRACKETR %016llx[%d] %016llx %02x %016llx lo=%02x %d\n",
973c11b9 460 (long long)cursor->node->node_offset,
32c90105 461 cursor->index + 1,
973c11b9 462 (long long)elm[1].internal.base.obj_id,
32c90105 463 elm[1].internal.base.rec_type,
973c11b9 464 (long long)elm[1].internal.base.key,
2f85fa4d 465 elm[1].internal.base.localization,
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466 s
467 );
468 }
469
470 if (s >= 0) {
471 error = ENOENT;
472 break;
473 }
474 KKASSERT(r >= 0);
475
476 /*
f36a9737 477 * Better not be zero
32c90105 478 */
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479 KKASSERT(elm->internal.subtree_offset != 0);
480
481 error = hammer_cursor_down(cursor);
482 if (error)
483 break;
484 KKASSERT(cursor->index == 0);
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485 /* reload stale pointer */
486 node = cursor->node->ondisk;
f36a9737
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487
488 /* this can assign -1 if the leaf was empty */
489 cursor->index = node->count - 1;
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490 continue;
491 } else {
492 elm = &node->elms[cursor->index];
493 s = hammer_btree_cmp(&cursor->key_beg, &elm->base);
494 if (hammer_debug_btree) {
2f85fa4d 495 kprintf("ELEMENT %016llx:%d %c %016llx %02x %016llx lo=%02x %d\n",
973c11b9 496 (long long)cursor->node->node_offset,
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497 cursor->index,
498 (elm[0].leaf.base.btype ?
499 elm[0].leaf.base.btype : '?'),
973c11b9 500 (long long)elm[0].leaf.base.obj_id,
32c90105 501 elm[0].leaf.base.rec_type,
973c11b9 502 (long long)elm[0].leaf.base.key,
2f85fa4d 503 elm[0].leaf.base.localization,
32c90105
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504 s
505 );
506 }
507 if (s > 0) {
508 error = ENOENT;
509 break;
510 }
511
512 switch(elm->leaf.base.btype) {
513 case HAMMER_BTREE_TYPE_RECORD:
514 if ((cursor->flags & HAMMER_CURSOR_ASOF) &&
515 hammer_btree_chkts(cursor->asof, &elm->base)) {
516 --cursor->index;
517 continue;
518 }
f75df937 519 error = 0;
32c90105 520 break;
32c90105
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521 default:
522 error = EINVAL;
523 break;
524 }
525 if (error)
526 break;
527 }
528 /*
529 * node pointer invalid after loop
530 */
531
532 /*
533 * Return entry
534 */
535 if (hammer_debug_btree) {
536 int i = cursor->index;
537 hammer_btree_elm_t elm = &cursor->node->ondisk->elms[i];
2f85fa4d 538 kprintf("ITERATE %p:%d %016llx %02x %016llx lo=%02x\n",
32c90105 539 cursor->node, i,
973c11b9 540 (long long)elm->internal.base.obj_id,
32c90105 541 elm->internal.base.rec_type,
973c11b9 542 (long long)elm->internal.base.key,
2f85fa4d 543 elm->internal.base.localization
32c90105
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544 );
545 }
546 return(0);
547 }
548 return(error);
549}
550
427e5fc6 551/*
8cd0a023 552 * Lookup cursor->key_beg. 0 is returned on success, ENOENT if the entry
6a37e7e4
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553 * could not be found, EDEADLK if inserting and a retry is needed, and a
554 * fatal error otherwise. When retrying, the caller must terminate the
eaeff70d 555 * cursor and reinitialize it. EDEADLK cannot be returned if not inserting.
8cd0a023
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556 *
557 * The cursor is suitably positioned for a deletion on success, and suitably
eaeff70d
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558 * positioned for an insertion on ENOENT if HAMMER_CURSOR_INSERT was
559 * specified.
427e5fc6 560 *
47197d71 561 * The cursor may begin anywhere, the search will traverse the tree in
8cd0a023 562 * either direction to locate the requested element.
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563 *
564 * Most of the logic implementing historical searches is handled here. We
9582c7da
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565 * do an initial lookup with create_tid set to the asof TID. Due to the
566 * way records are laid out, a backwards iteration may be required if
eaeff70d
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567 * ENOENT is returned to locate the historical record. Here's the
568 * problem:
569 *
9582c7da 570 * create_tid: 10 15 20
eaeff70d
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571 * LEAF1 LEAF2
572 * records: (11) (18)
573 *
9582c7da
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574 * Lets say we want to do a lookup AS-OF timestamp 17. We will traverse
575 * LEAF2 but the only record in LEAF2 has a create_tid of 18, which is
576 * not visible and thus causes ENOENT to be returned. We really need
577 * to check record 11 in LEAF1. If it also fails then the search fails
578 * (e.g. it might represent the range 11-16 and thus still not match our
f36a9737
MD
579 * AS-OF timestamp of 17). Note that LEAF1 could be empty, requiring
580 * further iterations.
b33e2cc0 581 *
9582c7da
MD
582 * If this case occurs btree_search() will set HAMMER_CURSOR_CREATE_CHECK
583 * and the cursor->create_check TID if an iteration might be needed.
584 * In the above example create_check would be set to 14.
427e5fc6
MD
585 */
586int
8cd0a023 587hammer_btree_lookup(hammer_cursor_t cursor)
427e5fc6 588{
66325755
MD
589 int error;
590
98da6d8c
MD
591 KKASSERT ((cursor->flags & HAMMER_CURSOR_INSERT) == 0 ||
592 cursor->trans->sync_lock_refs > 0);
cb51be26 593 ++hammer_stats_btree_lookups;
d5530d22 594 if (cursor->flags & HAMMER_CURSOR_ASOF) {
eaeff70d 595 KKASSERT((cursor->flags & HAMMER_CURSOR_INSERT) == 0);
9582c7da 596 cursor->key_beg.create_tid = cursor->asof;
eaeff70d 597 for (;;) {
9582c7da 598 cursor->flags &= ~HAMMER_CURSOR_CREATE_CHECK;
d5530d22 599 error = btree_search(cursor, 0);
b33e2cc0 600 if (error != ENOENT ||
9582c7da 601 (cursor->flags & HAMMER_CURSOR_CREATE_CHECK) == 0) {
b33e2cc0
MD
602 /*
603 * Stop if no error.
604 * Stop if error other then ENOENT.
605 * Stop if ENOENT and not special case.
606 */
eaeff70d
MD
607 break;
608 }
32c90105
MD
609 if (hammer_debug_btree) {
610 kprintf("CREATE_CHECK %016llx\n",
973c11b9 611 (long long)cursor->create_check);
32c90105 612 }
9582c7da 613 cursor->key_beg.create_tid = cursor->create_check;
eaeff70d
MD
614 /* loop */
615 }
d5530d22
MD
616 } else {
617 error = btree_search(cursor, 0);
618 }
bf3b416b 619 if (error == 0)
8cd0a023 620 error = hammer_btree_extract(cursor, cursor->flags);
66325755
MD
621 return(error);
622}
623
d26d0ae9
MD
624/*
625 * Execute the logic required to start an iteration. The first record
626 * located within the specified range is returned and iteration control
627 * flags are adjusted for successive hammer_btree_iterate() calls.
3214ade6
MD
628 *
629 * Set ATEDISK so a low-level caller can call btree_first/btree_iterate
630 * in a loop without worrying about it. Higher-level merged searches will
631 * adjust the flag appropriately.
d26d0ae9
MD
632 */
633int
634hammer_btree_first(hammer_cursor_t cursor)
635{
636 int error;
637
638 error = hammer_btree_lookup(cursor);
639 if (error == ENOENT) {
640 cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
641 error = hammer_btree_iterate(cursor);
642 }
643 cursor->flags |= HAMMER_CURSOR_ATEDISK;
644 return(error);
645}
646
32c90105
MD
647/*
648 * Similarly but for an iteration in the reverse direction.
814387f6
MD
649 *
650 * Set ATEDISK when iterating backwards to skip the current entry,
651 * which after an ENOENT lookup will be pointing beyond our end point.
3214ade6
MD
652 *
653 * Set ATEDISK so a low-level caller can call btree_last/btree_iterate_reverse
654 * in a loop without worrying about it. Higher-level merged searches will
655 * adjust the flag appropriately.
32c90105
MD
656 */
657int
658hammer_btree_last(hammer_cursor_t cursor)
659{
660 struct hammer_base_elm save;
661 int error;
662
663 save = cursor->key_beg;
664 cursor->key_beg = cursor->key_end;
665 error = hammer_btree_lookup(cursor);
666 cursor->key_beg = save;
667 if (error == ENOENT ||
668 (cursor->flags & HAMMER_CURSOR_END_INCLUSIVE) == 0) {
814387f6 669 cursor->flags |= HAMMER_CURSOR_ATEDISK;
32c90105
MD
670 error = hammer_btree_iterate_reverse(cursor);
671 }
672 cursor->flags |= HAMMER_CURSOR_ATEDISK;
673 return(error);
674}
675
8cd0a023
MD
676/*
677 * Extract the record and/or data associated with the cursor's current
678 * position. Any prior record or data stored in the cursor is replaced.
679 * The cursor must be positioned at a leaf node.
680 *
47197d71 681 * NOTE: All extractions occur at the leaf of the B-Tree.
8cd0a023 682 */
66325755 683int
8cd0a023 684hammer_btree_extract(hammer_cursor_t cursor, int flags)
66325755 685{
8cd0a023
MD
686 hammer_node_ondisk_t node;
687 hammer_btree_elm_t elm;
47197d71 688 hammer_off_t data_off;
bac808fe 689 hammer_mount_t hmp;
19619882 690 int32_t data_len;
427e5fc6 691 int error;
427e5fc6 692
8cd0a023 693 /*
427e5fc6
MD
694 * The case where the data reference resolves to the same buffer
695 * as the record reference must be handled.
696 */
8cd0a023 697 node = cursor->node->ondisk;
8cd0a023 698 elm = &node->elms[cursor->index];
40043e7f
MD
699 cursor->data = NULL;
700 hmp = cursor->node->hmp;
66325755 701
d26d0ae9 702 /*
fe7678ee 703 * There is nothing to extract for an internal element.
d26d0ae9 704 */
fe7678ee
MD
705 if (node->type == HAMMER_BTREE_TYPE_INTERNAL)
706 return(EINVAL);
707
47197d71
MD
708 /*
709 * Only record types have data.
710 */
fe7678ee 711 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
11ad5ade 712 cursor->leaf = &elm->leaf;
4a2796f3
MD
713
714 if ((flags & HAMMER_CURSOR_GET_DATA) == 0)
715 return(0);
47197d71 716 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
4a2796f3 717 return(0);
47197d71 718 data_off = elm->leaf.data_offset;
19619882 719 data_len = elm->leaf.data_len;
47197d71 720 if (data_off == 0)
4a2796f3 721 return(0);
d26d0ae9 722
4a2796f3
MD
723 /*
724 * Load the data
725 */
726 KKASSERT(data_len >= 0 && data_len <= HAMMER_XBUFSIZE);
727 cursor->data = hammer_bread_ext(hmp, data_off, data_len,
728 &error, &cursor->data_buffer);
2faf0737
MD
729 if (error == 0 &&
730 hammer_crc_test_leaf(cursor->data, &elm->leaf) == 0) {
e469566b 731 kprintf("CRC DATA @ %016llx/%d FAILED\n",
973c11b9 732 (long long)elm->leaf.data_offset, elm->leaf.data_len);
fc73edd8 733 if (hammer_debug_critical)
4c286c36
MD
734 Debugger("CRC FAILED: DATA");
735 if (cursor->trans->flags & HAMMER_TRANSF_CRCDOM)
736 error = EDOM; /* less critical (mirroring) */
737 else
738 error = EIO; /* critical */
e469566b 739 }
427e5fc6
MD
740 return(error);
741}
742
743
744/*
8cd0a023
MD
745 * Insert a leaf element into the B-Tree at the current cursor position.
746 * The cursor is positioned such that the element at and beyond the cursor
747 * are shifted to make room for the new record.
748 *
a89aec1b 749 * The caller must call hammer_btree_lookup() with the HAMMER_CURSOR_INSERT
8cd0a023
MD
750 * flag set and that call must return ENOENT before this function can be
751 * called.
752 *
d36ec43b 753 * The caller may depend on the cursor's exclusive lock after return to
1f07f686 754 * interlock frontend visibility (see HAMMER_RECF_CONVERT_DELETE).
d36ec43b 755 *
8cd0a023 756 * ENOSPC is returned if there is no room to insert a new record.
427e5fc6
MD
757 */
758int
602c6cb8
MD
759hammer_btree_insert(hammer_cursor_t cursor, hammer_btree_leaf_elm_t elm,
760 int *doprop)
427e5fc6 761{
8cd0a023 762 hammer_node_ondisk_t node;
427e5fc6 763 int i;
6a37e7e4
MD
764 int error;
765
602c6cb8 766 *doprop = 0;
7bc5b8c2 767 if ((error = hammer_cursor_upgrade_node(cursor)) != 0)
6a37e7e4 768 return(error);
cb51be26 769 ++hammer_stats_btree_inserts;
427e5fc6 770
427e5fc6
MD
771 /*
772 * Insert the element at the leaf node and update the count in the
773 * parent. It is possible for parent to be NULL, indicating that
47197d71
MD
774 * the filesystem's ROOT B-Tree node is a leaf itself, which is
775 * possible. The root inode can never be deleted so the leaf should
776 * never be empty.
427e5fc6
MD
777 *
778 * Remember that the right-hand boundary is not included in the
779 * count.
780 */
36f82b23 781 hammer_modify_node_all(cursor->trans, cursor->node);
8cd0a023 782 node = cursor->node->ondisk;
427e5fc6 783 i = cursor->index;
fe7678ee 784 KKASSERT(elm->base.btype != 0);
8cd0a023
MD
785 KKASSERT(node->type == HAMMER_BTREE_TYPE_LEAF);
786 KKASSERT(node->count < HAMMER_BTREE_LEAF_ELMS);
787 if (i != node->count) {
788 bcopy(&node->elms[i], &node->elms[i+1],
789 (node->count - i) * sizeof(*elm));
790 }
11ad5ade 791 node->elms[i].leaf = *elm;
8cd0a023 792 ++node->count;
e4a5ff06 793 hammer_cursor_inserted_element(cursor->node, i);
c82af904
MD
794
795 /*
796 * Update the leaf node's aggregate mirror_tid for mirroring
797 * support.
798 */
602c6cb8 799 if (node->mirror_tid < elm->base.delete_tid) {
c82af904 800 node->mirror_tid = elm->base.delete_tid;
602c6cb8
MD
801 *doprop = 1;
802 }
803 if (node->mirror_tid < elm->base.create_tid) {
c82af904 804 node->mirror_tid = elm->base.create_tid;
602c6cb8 805 *doprop = 1;
c82af904 806 }
602c6cb8 807 hammer_modify_node_done(cursor->node);
c82af904 808
eaeff70d 809 /*
47197d71 810 * Debugging sanity checks.
eaeff70d 811 */
11ad5ade
MD
812 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->base) <= 0);
813 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->base) > 0);
eaeff70d 814 if (i) {
11ad5ade 815 KKASSERT(hammer_btree_cmp(&node->elms[i-1].leaf.base, &elm->base) < 0);
eaeff70d 816 }
b3deaf57 817 if (i != node->count - 1)
11ad5ade 818 KKASSERT(hammer_btree_cmp(&node->elms[i+1].leaf.base, &elm->base) > 0);
b3deaf57 819
427e5fc6
MD
820 return(0);
821}
822
823/*
fe7678ee 824 * Delete a record from the B-Tree at the current cursor position.
8cd0a023
MD
825 * The cursor is positioned such that the current element is the one
826 * to be deleted.
827 *
195c19a1
MD
828 * On return the cursor will be positioned after the deleted element and
829 * MAY point to an internal node. It will be suitable for the continuation
830 * of an iteration but not for an insertion or deletion.
8cd0a023 831 *
195c19a1 832 * Deletions will attempt to partially rebalance the B-Tree in an upward
f36a9737
MD
833 * direction, but will terminate rather then deadlock. Empty internal nodes
834 * are never allowed by a deletion which deadlocks may end up giving us an
835 * empty leaf. The pruner will clean up and rebalance the tree.
46fe7ae1
MD
836 *
837 * This function can return EDEADLK, requiring the caller to retry the
838 * operation after clearing the deadlock.
427e5fc6
MD
839 */
840int
8cd0a023 841hammer_btree_delete(hammer_cursor_t cursor)
427e5fc6 842{
8cd0a023
MD
843 hammer_node_ondisk_t ondisk;
844 hammer_node_t node;
845 hammer_node_t parent;
8cd0a023 846 int error;
427e5fc6
MD
847 int i;
848
98da6d8c 849 KKASSERT (cursor->trans->sync_lock_refs > 0);
6a37e7e4
MD
850 if ((error = hammer_cursor_upgrade(cursor)) != 0)
851 return(error);
cb51be26 852 ++hammer_stats_btree_deletes;
6a37e7e4 853
427e5fc6 854 /*
8cd0a023 855 * Delete the element from the leaf node.
427e5fc6 856 *
8cd0a023 857 * Remember that leaf nodes do not have boundaries.
427e5fc6 858 */
8cd0a023
MD
859 node = cursor->node;
860 ondisk = node->ondisk;
427e5fc6
MD
861 i = cursor->index;
862
8cd0a023 863 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_LEAF);
fe7678ee 864 KKASSERT(i >= 0 && i < ondisk->count);
36f82b23 865 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
866 if (i + 1 != ondisk->count) {
867 bcopy(&ondisk->elms[i+1], &ondisk->elms[i],
868 (ondisk->count - i - 1) * sizeof(ondisk->elms[0]));
869 }
870 --ondisk->count;
10a5d1ba 871 hammer_modify_node_done(node);
b3bad96f 872 hammer_cursor_deleted_element(node, i);
fe7678ee
MD
873
874 /*
875 * Validate local parent
876 */
877 if (ondisk->parent) {
8cd0a023 878 parent = cursor->parent;
fe7678ee
MD
879
880 KKASSERT(parent != NULL);
881 KKASSERT(parent->node_offset == ondisk->parent);
427e5fc6 882 }
427e5fc6 883
8cd0a023 884 /*
fe7678ee 885 * If the leaf becomes empty it must be detached from the parent,
47197d71 886 * potentially recursing through to the filesystem root.
195c19a1
MD
887 *
888 * This may reposition the cursor at one of the parent's of the
889 * current node.
6a37e7e4
MD
890 *
891 * Ignore deadlock errors, that simply means that btree_remove
f36a9737 892 * was unable to recurse and had to leave us with an empty leaf.
8cd0a023 893 */
b3deaf57 894 KKASSERT(cursor->index <= ondisk->count);
8cd0a023 895 if (ondisk->count == 0) {
f36a9737 896 error = btree_remove(cursor);
6a37e7e4
MD
897 if (error == EDEADLK)
898 error = 0;
8cd0a023 899 } else {
8cd0a023
MD
900 error = 0;
901 }
eaeff70d
MD
902 KKASSERT(cursor->parent == NULL ||
903 cursor->parent_index < cursor->parent->ondisk->count);
8cd0a023
MD
904 return(error);
905}
427e5fc6
MD
906
907/*
8cd0a023
MD
908 * PRIMAY B-TREE SEARCH SUPPORT PROCEDURE
909 *
47197d71 910 * Search the filesystem B-Tree for cursor->key_beg, return the matching node.
8cd0a023 911 *
d26d0ae9
MD
912 * The search can begin ANYWHERE in the B-Tree. As a first step the search
913 * iterates up the tree as necessary to properly position itself prior to
914 * actually doing the sarch.
915 *
8cd0a023 916 * INSERTIONS: The search will split full nodes and leaves on its way down
d26d0ae9
MD
917 * and guarentee that the leaf it ends up on is not full. If we run out
918 * of space the search continues to the leaf (to position the cursor for
919 * the spike), but ENOSPC is returned.
427e5fc6 920 *
fbc6e32a
MD
921 * The search is only guarenteed to end up on a leaf if an error code of 0
922 * is returned, or if inserting and an error code of ENOENT is returned.
d26d0ae9 923 * Otherwise it can stop at an internal node. On success a search returns
47197d71 924 * a leaf node.
eaeff70d
MD
925 *
926 * COMPLEXITY WARNING! This is the core B-Tree search code for the entire
927 * filesystem, and it is not simple code. Please note the following facts:
928 *
929 * - Internal node recursions have a boundary on the left AND right. The
9582c7da 930 * right boundary is non-inclusive. The create_tid is a generic part
eaeff70d
MD
931 * of the key for internal nodes.
932 *
47197d71 933 * - Leaf nodes contain terminal elements only now.
eaeff70d
MD
934 *
935 * - Filesystem lookups typically set HAMMER_CURSOR_ASOF, indicating a
b33e2cc0
MD
936 * historical search. ASOF and INSERT are mutually exclusive. When
937 * doing an as-of lookup btree_search() checks for a right-edge boundary
9582c7da
MD
938 * case. If while recursing down the left-edge differs from the key
939 * by ONLY its create_tid, HAMMER_CURSOR_CREATE_CHECK is set along
940 * with cursor->create_check. This is used by btree_lookup() to iterate.
941 * The iteration backwards because as-of searches can wind up going
b33e2cc0 942 * down the wrong branch of the B-Tree.
427e5fc6 943 */
8cd0a023 944static
427e5fc6 945int
8cd0a023 946btree_search(hammer_cursor_t cursor, int flags)
427e5fc6 947{
8cd0a023 948 hammer_node_ondisk_t node;
61aeeb33 949 hammer_btree_elm_t elm;
8cd0a023 950 int error;
d26d0ae9 951 int enospc = 0;
8cd0a023
MD
952 int i;
953 int r;
b33e2cc0 954 int s;
8cd0a023
MD
955
956 flags |= cursor->flags;
cb51be26 957 ++hammer_stats_btree_searches;
8cd0a023 958
b3deaf57 959 if (hammer_debug_btree) {
2f85fa4d 960 kprintf("SEARCH %016llx[%d] %016llx %02x key=%016llx cre=%016llx lo=%02x (td = %p)\n",
973c11b9 961 (long long)cursor->node->node_offset,
eaeff70d 962 cursor->index,
973c11b9 963 (long long)cursor->key_beg.obj_id,
b3deaf57 964 cursor->key_beg.rec_type,
973c11b9
MD
965 (long long)cursor->key_beg.key,
966 (long long)cursor->key_beg.create_tid,
2f85fa4d 967 cursor->key_beg.localization,
a84a197d 968 curthread
b3deaf57 969 );
a84a197d
MD
970 if (cursor->parent)
971 kprintf("SEARCHP %016llx[%d] (%016llx/%016llx %016llx/%016llx) (%p/%p %p/%p)\n",
973c11b9
MD
972 (long long)cursor->parent->node_offset,
973 cursor->parent_index,
974 (long long)cursor->left_bound->obj_id,
975 (long long)cursor->parent->ondisk->elms[cursor->parent_index].internal.base.obj_id,
976 (long long)cursor->right_bound->obj_id,
977 (long long)cursor->parent->ondisk->elms[cursor->parent_index+1].internal.base.obj_id,
a84a197d
MD
978 cursor->left_bound,
979 &cursor->parent->ondisk->elms[cursor->parent_index],
980 cursor->right_bound,
981 &cursor->parent->ondisk->elms[cursor->parent_index+1]
982 );
b3deaf57
MD
983 }
984
8cd0a023
MD
985 /*
986 * Move our cursor up the tree until we find a node whos range covers
47197d71 987 * the key we are trying to locate.
8cd0a023
MD
988 *
989 * The left bound is inclusive, the right bound is non-inclusive.
47197d71 990 * It is ok to cursor up too far.
8cd0a023 991 */
b33e2cc0
MD
992 for (;;) {
993 r = hammer_btree_cmp(&cursor->key_beg, cursor->left_bound);
994 s = hammer_btree_cmp(&cursor->key_beg, cursor->right_bound);
995 if (r >= 0 && s < 0)
996 break;
9944ae54 997 KKASSERT(cursor->parent);
cb51be26 998 ++hammer_stats_btree_iterations;
6a37e7e4 999 error = hammer_cursor_up(cursor);
8cd0a023
MD
1000 if (error)
1001 goto done;
427e5fc6 1002 }
427e5fc6 1003
b33e2cc0
MD
1004 /*
1005 * The delete-checks below are based on node, not parent. Set the
1006 * initial delete-check based on the parent.
1007 */
9582c7da
MD
1008 if (r == 1) {
1009 KKASSERT(cursor->left_bound->create_tid != 1);
1010 cursor->create_check = cursor->left_bound->create_tid - 1;
1011 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0
MD
1012 }
1013
8cd0a023 1014 /*
47197d71 1015 * We better have ended up with a node somewhere.
8cd0a023 1016 */
47197d71 1017 KKASSERT(cursor->node != NULL);
8cd0a023
MD
1018
1019 /*
1020 * If we are inserting we can't start at a full node if the parent
1021 * is also full (because there is no way to split the node),
b33e2cc0 1022 * continue running up the tree until the requirement is satisfied
47197d71 1023 * or we hit the root of the filesystem.
9582c7da
MD
1024 *
1025 * (If inserting we aren't doing an as-of search so we don't have
1026 * to worry about create_check).
8cd0a023 1027 */
61aeeb33 1028 while ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
eaeff70d
MD
1029 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
1030 if (btree_node_is_full(cursor->node->ondisk) == 0)
1031 break;
1032 } else {
47197d71 1033 if (btree_node_is_full(cursor->node->ondisk) ==0)
eaeff70d
MD
1034 break;
1035 }
b33e2cc0
MD
1036 if (cursor->node->ondisk->parent == 0 ||
1037 cursor->parent->ondisk->count != HAMMER_BTREE_INT_ELMS) {
8cd0a023 1038 break;
b33e2cc0 1039 }
cb51be26 1040 ++hammer_stats_btree_iterations;
6a37e7e4 1041 error = hammer_cursor_up(cursor);
47197d71 1042 /* node may have become stale */
8cd0a023
MD
1043 if (error)
1044 goto done;
427e5fc6 1045 }
427e5fc6 1046
8cd0a023
MD
1047 /*
1048 * Push down through internal nodes to locate the requested key.
1049 */
8cd0a023
MD
1050 node = cursor->node->ondisk;
1051 while (node->type == HAMMER_BTREE_TYPE_INTERNAL) {
8cd0a023
MD
1052 /*
1053 * Scan the node to find the subtree index to push down into.
fbc6e32a 1054 * We go one-past, then back-up.
d113fda1 1055 *
fe7678ee
MD
1056 * We must proactively remove deleted elements which may
1057 * have been left over from a deadlocked btree_remove().
1058 *
eaeff70d 1059 * The left and right boundaries are included in the loop
d5530d22 1060 * in order to detect edge cases.
9944ae54 1061 *
9582c7da 1062 * If the separator only differs by create_tid (r == 1)
eaeff70d
MD
1063 * and we are doing an as-of search, we may end up going
1064 * down a branch to the left of the one containing the
1065 * desired key. This requires numerous special cases.
8cd0a023 1066 */
47637bff 1067 ++hammer_stats_btree_iterations;
46fe7ae1 1068 if (hammer_debug_btree) {
47197d71 1069 kprintf("SEARCH-I %016llx count=%d\n",
973c11b9 1070 (long long)cursor->node->node_offset,
46fe7ae1
MD
1071 node->count);
1072 }
af209b0f
MD
1073
1074 /*
1075 * Try to shortcut the search before dropping into the
1076 * linear loop. Locate the first node where r <= 1.
1077 */
1078 i = hammer_btree_search_node(&cursor->key_beg, node);
1079 while (i <= node->count) {
cb51be26 1080 ++hammer_stats_btree_elements;
61aeeb33
MD
1081 elm = &node->elms[i];
1082 r = hammer_btree_cmp(&cursor->key_beg, &elm->base);
b33e2cc0
MD
1083 if (hammer_debug_btree > 2) {
1084 kprintf(" IELM %p %d r=%d\n",
1085 &node->elms[i], i, r);
1086 }
9582c7da 1087 if (r < 0)
8cd0a023 1088 break;
9582c7da
MD
1089 if (r == 1) {
1090 KKASSERT(elm->base.create_tid != 1);
1091 cursor->create_check = elm->base.create_tid - 1;
1092 cursor->flags |= HAMMER_CURSOR_CREATE_CHECK;
b33e2cc0 1093 }
af209b0f 1094 ++i;
8cd0a023 1095 }
eaeff70d 1096 if (hammer_debug_btree) {
46fe7ae1
MD
1097 kprintf("SEARCH-I preI=%d/%d r=%d\n",
1098 i, node->count, r);
eaeff70d 1099 }
8cd0a023
MD
1100
1101 /*
9944ae54
MD
1102 * These cases occur when the parent's idea of the boundary
1103 * is wider then the child's idea of the boundary, and
1104 * require special handling. If not inserting we can
1105 * terminate the search early for these cases but the
1106 * child's boundaries cannot be unconditionally modified.
8cd0a023 1107 */
fbc6e32a 1108 if (i == 0) {
9944ae54
MD
1109 /*
1110 * If i == 0 the search terminated to the LEFT of the
1111 * left_boundary but to the RIGHT of the parent's left
1112 * boundary.
1113 */
fbc6e32a 1114 u_int8_t save;
d26d0ae9 1115
eaeff70d
MD
1116 elm = &node->elms[0];
1117
1118 /*
1119 * If we aren't inserting we can stop here.
1120 */
11ad5ade
MD
1121 if ((flags & (HAMMER_CURSOR_INSERT |
1122 HAMMER_CURSOR_PRUNING)) == 0) {
fbc6e32a
MD
1123 cursor->index = 0;
1124 return(ENOENT);
1125 }
9944ae54 1126
d5530d22
MD
1127 /*
1128 * Correct a left-hand boundary mismatch.
6a37e7e4 1129 *
f36a9737
MD
1130 * We can only do this if we can upgrade the lock,
1131 * and synchronized as a background cursor (i.e.
1132 * inserting or pruning).
10a5d1ba
MD
1133 *
1134 * WARNING: We can only do this if inserting, i.e.
1135 * we are running on the backend.
d5530d22 1136 */
eaeff70d
MD
1137 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1138 return(error);
10a5d1ba 1139 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
c9b9e29d
MD
1140 hammer_modify_node_field(cursor->trans, cursor->node,
1141 elms[0]);
fe7678ee 1142 save = node->elms[0].base.btype;
d5530d22 1143 node->elms[0].base = *cursor->left_bound;
fe7678ee 1144 node->elms[0].base.btype = save;
10a5d1ba 1145 hammer_modify_node_done(cursor->node);
9944ae54 1146 } else if (i == node->count + 1) {
d26d0ae9 1147 /*
9944ae54
MD
1148 * If i == node->count + 1 the search terminated to
1149 * the RIGHT of the right boundary but to the LEFT
eaeff70d
MD
1150 * of the parent's right boundary. If we aren't
1151 * inserting we can stop here.
d113fda1 1152 *
9944ae54
MD
1153 * Note that the last element in this case is
1154 * elms[i-2] prior to adjustments to 'i'.
d26d0ae9 1155 */
9944ae54 1156 --i;
11ad5ade
MD
1157 if ((flags & (HAMMER_CURSOR_INSERT |
1158 HAMMER_CURSOR_PRUNING)) == 0) {
9944ae54 1159 cursor->index = i;
eaeff70d 1160 return (ENOENT);
d26d0ae9
MD
1161 }
1162
d5530d22
MD
1163 /*
1164 * Correct a right-hand boundary mismatch.
1165 * (actual push-down record is i-2 prior to
1166 * adjustments to i).
6a37e7e4 1167 *
f36a9737
MD
1168 * We can only do this if we can upgrade the lock,
1169 * and synchronized as a background cursor (i.e.
1170 * inserting or pruning).
10a5d1ba
MD
1171 *
1172 * WARNING: We can only do this if inserting, i.e.
1173 * we are running on the backend.
d5530d22 1174 */
eaeff70d
MD
1175 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1176 return(error);
9944ae54 1177 elm = &node->elms[i];
10a5d1ba 1178 KKASSERT(cursor->flags & HAMMER_CURSOR_BACKEND);
36f82b23
MD
1179 hammer_modify_node(cursor->trans, cursor->node,
1180 &elm->base, sizeof(elm->base));
d5530d22 1181 elm->base = *cursor->right_bound;
10a5d1ba 1182 hammer_modify_node_done(cursor->node);
d5530d22 1183 --i;
fbc6e32a
MD
1184 } else {
1185 /*
9944ae54
MD
1186 * The push-down index is now i - 1. If we had
1187 * terminated on the right boundary this will point
1188 * us at the last element.
fbc6e32a
MD
1189 */
1190 --i;
1191 }
8cd0a023 1192 cursor->index = i;
6a37e7e4 1193 elm = &node->elms[i];
8cd0a023 1194
b3deaf57 1195 if (hammer_debug_btree) {
47197d71 1196 kprintf("RESULT-I %016llx[%d] %016llx %02x "
2f85fa4d 1197 "key=%016llx cre=%016llx lo=%02x\n",
973c11b9 1198 (long long)cursor->node->node_offset,
eaeff70d 1199 i,
973c11b9 1200 (long long)elm->internal.base.obj_id,
b3deaf57 1201 elm->internal.base.rec_type,
973c11b9
MD
1202 (long long)elm->internal.base.key,
1203 (long long)elm->internal.base.create_tid,
2f85fa4d 1204 elm->internal.base.localization
b3deaf57
MD
1205 );
1206 }
1207
6a37e7e4 1208 /*
f36a9737 1209 * We better have a valid subtree offset.
6a37e7e4 1210 */
f36a9737 1211 KKASSERT(elm->internal.subtree_offset != 0);
6a37e7e4 1212
8cd0a023
MD
1213 /*
1214 * Handle insertion and deletion requirements.
1215 *
1216 * If inserting split full nodes. The split code will
1217 * adjust cursor->node and cursor->index if the current
1218 * index winds up in the new node.
61aeeb33 1219 *
9944ae54
MD
1220 * If inserting and a left or right edge case was detected,
1221 * we cannot correct the left or right boundary and must
1222 * prepend and append an empty leaf node in order to make
1223 * the boundary correction.
1224 *
61aeeb33
MD
1225 * If we run out of space we set enospc and continue on
1226 * to a leaf to provide the spike code with a good point
47197d71 1227 * of entry.
8cd0a023 1228 */
61aeeb33 1229 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0) {
fe7678ee 1230 if (btree_node_is_full(node)) {
8cd0a023 1231 error = btree_split_internal(cursor);
d26d0ae9
MD
1232 if (error) {
1233 if (error != ENOSPC)
1234 goto done;
1235 enospc = 1;
d26d0ae9 1236 }
8cd0a023
MD
1237 /*
1238 * reload stale pointers
1239 */
1240 i = cursor->index;
1241 node = cursor->node->ondisk;
1242 }
d26d0ae9 1243 }
427e5fc6
MD
1244
1245 /*
8cd0a023 1246 * Push down (push into new node, existing node becomes
d26d0ae9 1247 * the parent) and continue the search.
427e5fc6 1248 */
8cd0a023 1249 error = hammer_cursor_down(cursor);
47197d71 1250 /* node may have become stale */
8cd0a023
MD
1251 if (error)
1252 goto done;
1253 node = cursor->node->ondisk;
427e5fc6 1254 }
427e5fc6 1255
8cd0a023
MD
1256 /*
1257 * We are at a leaf, do a linear search of the key array.
d26d0ae9
MD
1258 *
1259 * On success the index is set to the matching element and 0
1260 * is returned.
1261 *
1262 * On failure the index is set to the insertion point and ENOENT
1263 * is returned.
8cd0a023
MD
1264 *
1265 * Boundaries are not stored in leaf nodes, so the index can wind
1266 * up to the left of element 0 (index == 0) or past the end of
f36a9737
MD
1267 * the array (index == node->count). It is also possible that the
1268 * leaf might be empty.
8cd0a023 1269 */
47637bff 1270 ++hammer_stats_btree_iterations;
fe7678ee 1271 KKASSERT (node->type == HAMMER_BTREE_TYPE_LEAF);
8cd0a023 1272 KKASSERT(node->count <= HAMMER_BTREE_LEAF_ELMS);
46fe7ae1 1273 if (hammer_debug_btree) {
47197d71 1274 kprintf("SEARCH-L %016llx count=%d\n",
973c11b9 1275 (long long)cursor->node->node_offset,
46fe7ae1
MD
1276 node->count);
1277 }
8cd0a023 1278
af209b0f
MD
1279 /*
1280 * Try to shortcut the search before dropping into the
1281 * linear loop. Locate the first node where r <= 1.
1282 */
1283 i = hammer_btree_search_node(&cursor->key_beg, node);
1284 while (i < node->count) {
cb51be26 1285 ++hammer_stats_btree_elements;
fe7678ee
MD
1286 elm = &node->elms[i];
1287
1288 r = hammer_btree_cmp(&cursor->key_beg, &elm->leaf.base);
427e5fc6 1289
d5530d22
MD
1290 if (hammer_debug_btree > 1)
1291 kprintf(" ELM %p %d r=%d\n", &node->elms[i], i, r);
1292
427e5fc6 1293 /*
fe7678ee 1294 * We are at a record element. Stop if we've flipped past
9582c7da
MD
1295 * key_beg, not counting the create_tid test. Allow the
1296 * r == 1 case (key_beg > element but differs only by its
1297 * create_tid) to fall through to the AS-OF check.
427e5fc6 1298 */
fe7678ee
MD
1299 KKASSERT (elm->leaf.base.btype == HAMMER_BTREE_TYPE_RECORD);
1300
9582c7da 1301 if (r < 0)
d5530d22 1302 goto failed;
af209b0f
MD
1303 if (r > 1) {
1304 ++i;
d5530d22 1305 continue;
af209b0f 1306 }
427e5fc6 1307
66325755 1308 /*
9582c7da 1309 * Check our as-of timestamp against the element.
66325755 1310 */
eaeff70d 1311 if (flags & HAMMER_CURSOR_ASOF) {
fe7678ee 1312 if (hammer_btree_chkts(cursor->asof,
d113fda1 1313 &node->elms[i].base) != 0) {
af209b0f 1314 ++i;
d113fda1
MD
1315 continue;
1316 }
eaeff70d
MD
1317 /* success */
1318 } else {
af209b0f
MD
1319 if (r > 0) { /* can only be +1 */
1320 ++i;
9582c7da 1321 continue;
af209b0f 1322 }
eaeff70d 1323 /* success */
66325755 1324 }
d5530d22
MD
1325 cursor->index = i;
1326 error = 0;
eaeff70d 1327 if (hammer_debug_btree) {
47197d71 1328 kprintf("RESULT-L %016llx[%d] (SUCCESS)\n",
973c11b9 1329 (long long)cursor->node->node_offset, i);
eaeff70d 1330 }
d5530d22
MD
1331 goto done;
1332 }
1333
1334 /*
eaeff70d 1335 * The search of the leaf node failed. i is the insertion point.
d5530d22 1336 */
d5530d22 1337failed:
b3deaf57 1338 if (hammer_debug_btree) {
47197d71 1339 kprintf("RESULT-L %016llx[%d] (FAILED)\n",
973c11b9 1340 (long long)cursor->node->node_offset, i);
b3deaf57
MD
1341 }
1342
8cd0a023
MD
1343 /*
1344 * No exact match was found, i is now at the insertion point.
1345 *
1346 * If inserting split a full leaf before returning. This
1347 * may have the side effect of adjusting cursor->node and
1348 * cursor->index.
1349 */
1350 cursor->index = i;
eaeff70d 1351 if ((flags & HAMMER_CURSOR_INSERT) && enospc == 0 &&
47197d71 1352 btree_node_is_full(node)) {
8cd0a023 1353 error = btree_split_leaf(cursor);
d26d0ae9
MD
1354 if (error) {
1355 if (error != ENOSPC)
1356 goto done;
1357 enospc = 1;
d26d0ae9
MD
1358 }
1359 /*
1360 * reload stale pointers
1361 */
8cd0a023
MD
1362 /* NOT USED
1363 i = cursor->index;
1364 node = &cursor->node->internal;
1365 */
8cd0a023 1366 }
d26d0ae9
MD
1367
1368 /*
1369 * We reached a leaf but did not find the key we were looking for.
1370 * If this is an insert we will be properly positioned for an insert
1371 * (ENOENT) or spike (ENOSPC) operation.
1372 */
1373 error = enospc ? ENOSPC : ENOENT;
8cd0a023 1374done:
427e5fc6
MD
1375 return(error);
1376}
1377
af209b0f
MD
1378/*
1379 * Heuristical search for the first element whos comparison is <= 1. May
1380 * return an index whos compare result is > 1 but may only return an index
1381 * whos compare result is <= 1 if it is the first element with that result.
1382 */
bcac4bbb 1383int
af209b0f
MD
1384hammer_btree_search_node(hammer_base_elm_t elm, hammer_node_ondisk_t node)
1385{
1386 int b;
1387 int s;
1388 int i;
1389 int r;
1390
1391 /*
1392 * Don't bother if the node does not have very many elements
1393 */
1394 b = 0;
1395 s = node->count;
1396 while (s - b > 4) {
1397 i = b + (s - b) / 2;
cb51be26 1398 ++hammer_stats_btree_elements;
af209b0f
MD
1399 r = hammer_btree_cmp(elm, &node->elms[i].leaf.base);
1400 if (r <= 1) {
1401 s = i;
1402 } else {
1403 b = i;
1404 }
1405 }
1406 return(b);
1407}
1408
8cd0a023 1409
427e5fc6 1410/************************************************************************
8cd0a023 1411 * SPLITTING AND MERGING *
427e5fc6
MD
1412 ************************************************************************
1413 *
1414 * These routines do all the dirty work required to split and merge nodes.
1415 */
1416
1417/*
8cd0a023 1418 * Split an internal node into two nodes and move the separator at the split
fe7678ee 1419 * point to the parent.
427e5fc6 1420 *
8cd0a023
MD
1421 * (cursor->node, cursor->index) indicates the element the caller intends
1422 * to push into. We will adjust node and index if that element winds
427e5fc6 1423 * up in the split node.
8cd0a023 1424 *
47197d71
MD
1425 * If we are at the root of the filesystem a new root must be created with
1426 * two elements, one pointing to the original root and one pointing to the
8cd0a023 1427 * newly allocated split node.
427e5fc6
MD
1428 */
1429static
1430int
8cd0a023 1431btree_split_internal(hammer_cursor_t cursor)
427e5fc6 1432{
8cd0a023
MD
1433 hammer_node_ondisk_t ondisk;
1434 hammer_node_t node;
1435 hammer_node_t parent;
1436 hammer_node_t new_node;
1437 hammer_btree_elm_t elm;
1438 hammer_btree_elm_t parent_elm;
1775b6a0 1439 struct hammer_node_lock lockroot;
36f82b23 1440 hammer_mount_t hmp = cursor->trans->hmp;
df2ccbac 1441 hammer_off_t hint;
427e5fc6
MD
1442 int parent_index;
1443 int made_root;
1444 int split;
1445 int error;
7f7c1f84 1446 int i;
8cd0a023 1447 const int esize = sizeof(*elm);
427e5fc6 1448
1775b6a0
MD
1449 hammer_node_lock_init(&lockroot, cursor->node);
1450 error = hammer_btree_lock_children(cursor, 1, &lockroot);
47197d71
MD
1451 if (error)
1452 goto done;
7bc5b8c2
MD
1453 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1454 goto done;
cb51be26 1455 ++hammer_stats_btree_splits;
6a37e7e4 1456
427e5fc6
MD
1457 /*
1458 * We are splitting but elms[split] will be promoted to the parent,
1459 * leaving the right hand node with one less element. If the
1460 * insertion point will be on the left-hand side adjust the split
1461 * point to give the right hand side one additional node.
1462 */
8cd0a023
MD
1463 node = cursor->node;
1464 ondisk = node->ondisk;
1465 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1466 if (cursor->index <= split)
1467 --split;
427e5fc6
MD
1468
1469 /*
47197d71
MD
1470 * If we are at the root of the filesystem, create a new root node
1471 * with 1 element and split normally. Avoid making major
1472 * modifications until we know the whole operation will work.
427e5fc6 1473 */
8cd0a023 1474 if (ondisk->parent == 0) {
df2ccbac
MD
1475 parent = hammer_alloc_btree(cursor->trans, node->node_offset,
1476 &error);
427e5fc6 1477 if (parent == NULL)
6a37e7e4 1478 goto done;
8cd0a023 1479 hammer_lock_ex(&parent->lock);
36f82b23 1480 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1481 ondisk = parent->ondisk;
1482 ondisk->count = 1;
1483 ondisk->parent = 0;
a56cb012 1484 ondisk->mirror_tid = node->ondisk->mirror_tid;
8cd0a023 1485 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1486 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1487 ondisk->elms[0].base.btype = node->ondisk->type;
8cd0a023 1488 ondisk->elms[0].internal.subtree_offset = node->node_offset;
47197d71 1489 ondisk->elms[1].base = hmp->root_btree_end;
10a5d1ba 1490 hammer_modify_node_done(parent);
fe7678ee 1491 /* ondisk->elms[1].base.btype - not used */
427e5fc6 1492 made_root = 1;
8cd0a023 1493 parent_index = 0; /* index of current node in parent */
427e5fc6
MD
1494 } else {
1495 made_root = 0;
8cd0a023
MD
1496 parent = cursor->parent;
1497 parent_index = cursor->parent_index;
427e5fc6 1498 }
427e5fc6 1499
df2ccbac
MD
1500 /*
1501 * Calculate a hint for the allocation of the new B-Tree node.
1502 * The most likely expansion is coming from the insertion point
1503 * at cursor->index, so try to localize the allocation of our
1504 * new node to accomodate that sub-tree.
1505 *
1506 * Use the right-most sub-tree when expandinging on the right edge.
1507 * This is a very common case when copying a directory tree.
1508 */
1509 if (cursor->index == ondisk->count)
1510 hint = ondisk->elms[cursor->index - 1].internal.subtree_offset;
1511 else
1512 hint = ondisk->elms[cursor->index].internal.subtree_offset;
1513
427e5fc6
MD
1514 /*
1515 * Split node into new_node at the split point.
1516 *
df2ccbac 1517 * B O O O P N N B <-- P = node->elms[split] (index 4)
427e5fc6
MD
1518 * 0 1 2 3 4 5 6 <-- subtree indices
1519 *
1520 * x x P x x
1521 * s S S s
1522 * / \
1523 * B O O O B B N N B <--- inner boundary points are 'P'
1524 * 0 1 2 3 4 5 6
427e5fc6 1525 */
df2ccbac 1526 new_node = hammer_alloc_btree(cursor->trans, hint, &error);
427e5fc6 1527 if (new_node == NULL) {
8cd0a023
MD
1528 if (made_root) {
1529 hammer_unlock(&parent->lock);
36f82b23 1530 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1531 hammer_rel_node(parent);
1532 }
6a37e7e4 1533 goto done;
427e5fc6 1534 }
8cd0a023 1535 hammer_lock_ex(&new_node->lock);
427e5fc6
MD
1536
1537 /*
8cd0a023 1538 * Create the new node. P becomes the left-hand boundary in the
427e5fc6
MD
1539 * new node. Copy the right-hand boundary as well.
1540 *
1541 * elm is the new separator.
1542 */
36f82b23
MD
1543 hammer_modify_node_noundo(cursor->trans, new_node);
1544 hammer_modify_node_all(cursor->trans, node);
8cd0a023
MD
1545 ondisk = node->ondisk;
1546 elm = &ondisk->elms[split];
1547 bcopy(elm, &new_node->ondisk->elms[0],
1548 (ondisk->count - split + 1) * esize);
1549 new_node->ondisk->count = ondisk->count - split;
1550 new_node->ondisk->parent = parent->node_offset;
1551 new_node->ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
a56cb012 1552 new_node->ondisk->mirror_tid = ondisk->mirror_tid;
8cd0a023 1553 KKASSERT(ondisk->type == new_node->ondisk->type);
b3bad96f 1554 hammer_cursor_split_node(node, new_node, split);
427e5fc6
MD
1555
1556 /*
fe7678ee
MD
1557 * Cleanup the original node. Elm (P) becomes the new boundary,
1558 * its subtree_offset was moved to the new node. If we had created
427e5fc6
MD
1559 * a new root its parent pointer may have changed.
1560 */
8cd0a023 1561 elm->internal.subtree_offset = 0;
c0ade690 1562 ondisk->count = split;
427e5fc6
MD
1563
1564 /*
1565 * Insert the separator into the parent, fixup the parent's
1566 * reference to the original node, and reference the new node.
1567 * The separator is P.
1568 *
1569 * Remember that base.count does not include the right-hand boundary.
1570 */
36f82b23 1571 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1572 ondisk = parent->ondisk;
d26d0ae9 1573 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1574 parent_elm = &ondisk->elms[parent_index+1];
427e5fc6 1575 bcopy(parent_elm, parent_elm + 1,
8cd0a023
MD
1576 (ondisk->count - parent_index) * esize);
1577 parent_elm->internal.base = elm->base; /* separator P */
fe7678ee 1578 parent_elm->internal.base.btype = new_node->ondisk->type;
8cd0a023 1579 parent_elm->internal.subtree_offset = new_node->node_offset;
a56cb012 1580 parent_elm->internal.mirror_tid = new_node->ondisk->mirror_tid;
76376933 1581 ++ondisk->count;
10a5d1ba 1582 hammer_modify_node_done(parent);
b3bad96f 1583 hammer_cursor_inserted_element(parent, parent_index + 1);
427e5fc6 1584
7f7c1f84
MD
1585 /*
1586 * The children of new_node need their parent pointer set to new_node.
b33e2cc0
MD
1587 * The children have already been locked by
1588 * hammer_btree_lock_children().
7f7c1f84
MD
1589 */
1590 for (i = 0; i < new_node->ondisk->count; ++i) {
1591 elm = &new_node->ondisk->elms[i];
36f82b23 1592 error = btree_set_parent(cursor->trans, new_node, elm);
7f7c1f84
MD
1593 if (error) {
1594 panic("btree_split_internal: btree-fixup problem");
1595 }
1596 }
10a5d1ba 1597 hammer_modify_node_done(new_node);
7f7c1f84 1598
427e5fc6 1599 /*
47197d71 1600 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1601 */
1602 if (made_root) {
47197d71
MD
1603 hammer_volume_t volume;
1604
1605 volume = hammer_get_root_volume(hmp, &error);
1606 KKASSERT(error == 0);
1607
e8599db1
MD
1608 hammer_modify_volume_field(cursor->trans, volume,
1609 vol0_btree_root);
47197d71 1610 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1611 hammer_modify_volume_done(volume);
8cd0a023
MD
1612 node->ondisk->parent = parent->node_offset;
1613 if (cursor->parent) {
1614 hammer_unlock(&cursor->parent->lock);
1615 hammer_rel_node(cursor->parent);
1616 }
1617 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1618 hammer_rel_volume(volume, 0);
427e5fc6 1619 }
10a5d1ba 1620 hammer_modify_node_done(node);
427e5fc6
MD
1621
1622 /*
1623 * Ok, now adjust the cursor depending on which element the original
1624 * index was pointing at. If we are >= the split point the push node
1625 * is now in the new node.
1626 *
1627 * NOTE: If we are at the split point itself we cannot stay with the
1628 * original node because the push index will point at the right-hand
1629 * boundary, which is illegal.
8cd0a023
MD
1630 *
1631 * NOTE: The cursor's parent or parent_index must be adjusted for
1632 * the case where a new parent (new root) was created, and the case
1633 * where the cursor is now pointing at the split node.
427e5fc6
MD
1634 */
1635 if (cursor->index >= split) {
8cd0a023 1636 cursor->parent_index = parent_index + 1;
427e5fc6 1637 cursor->index -= split;
8cd0a023
MD
1638 hammer_unlock(&cursor->node->lock);
1639 hammer_rel_node(cursor->node);
1640 cursor->node = new_node; /* locked and ref'd */
1641 } else {
1642 cursor->parent_index = parent_index;
1643 hammer_unlock(&new_node->lock);
1644 hammer_rel_node(new_node);
427e5fc6 1645 }
76376933
MD
1646
1647 /*
1648 * Fixup left and right bounds
1649 */
1650 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1651 cursor->left_bound = &parent_elm[0].internal.base;
1652 cursor->right_bound = &parent_elm[1].internal.base;
b3deaf57
MD
1653 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1654 &cursor->node->ondisk->elms[0].internal.base) <= 0);
1655 KKASSERT(hammer_btree_cmp(cursor->right_bound,
9944ae54 1656 &cursor->node->ondisk->elms[cursor->node->ondisk->count].internal.base) >= 0);
76376933 1657
6a37e7e4 1658done:
1775b6a0 1659 hammer_btree_unlock_children(cursor, &lockroot);
6a37e7e4
MD
1660 hammer_cursor_downgrade(cursor);
1661 return (error);
427e5fc6
MD
1662}
1663
1664/*
1665 * Same as the above, but splits a full leaf node.
6a37e7e4
MD
1666 *
1667 * This function
427e5fc6
MD
1668 */
1669static
1670int
8cd0a023 1671btree_split_leaf(hammer_cursor_t cursor)
427e5fc6 1672{
8cd0a023
MD
1673 hammer_node_ondisk_t ondisk;
1674 hammer_node_t parent;
1675 hammer_node_t leaf;
47197d71 1676 hammer_mount_t hmp;
8cd0a023
MD
1677 hammer_node_t new_leaf;
1678 hammer_btree_elm_t elm;
1679 hammer_btree_elm_t parent_elm;
b3deaf57 1680 hammer_base_elm_t mid_boundary;
df2ccbac 1681 hammer_off_t hint;
427e5fc6
MD
1682 int parent_index;
1683 int made_root;
1684 int split;
1685 int error;
8cd0a023 1686 const size_t esize = sizeof(*elm);
427e5fc6 1687
6a37e7e4
MD
1688 if ((error = hammer_cursor_upgrade(cursor)) != 0)
1689 return(error);
cb51be26 1690 ++hammer_stats_btree_splits;
6a37e7e4 1691
36f82b23
MD
1692 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1693 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1694 KKASSERT(hammer_btree_cmp(cursor->right_bound,
1695 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
1696
427e5fc6 1697 /*
8cd0a023
MD
1698 * Calculate the split point. If the insertion point will be on
1699 * the left-hand side adjust the split point to give the right
1700 * hand side one additional node.
fe7678ee
MD
1701 *
1702 * Spikes are made up of two leaf elements which cannot be
1703 * safely split.
427e5fc6 1704 */
8cd0a023
MD
1705 leaf = cursor->node;
1706 ondisk = leaf->ondisk;
c9ce54d6 1707 KKASSERT(ondisk->count > 2);
8cd0a023 1708 split = (ondisk->count + 1) / 2;
427e5fc6
MD
1709 if (cursor->index <= split)
1710 --split;
1711 error = 0;
40043e7f 1712 hmp = leaf->hmp;
427e5fc6 1713
fe7678ee 1714 elm = &ondisk->elms[split];
fe7678ee 1715
36f82b23
MD
1716 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm[-1].leaf.base) <= 0);
1717 KKASSERT(hammer_btree_cmp(cursor->left_bound, &elm->leaf.base) <= 0);
1718 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm->leaf.base) > 0);
1719 KKASSERT(hammer_btree_cmp(cursor->right_bound, &elm[1].leaf.base) > 0);
1720
427e5fc6
MD
1721 /*
1722 * If we are at the root of the tree, create a new root node with
1723 * 1 element and split normally. Avoid making major modifications
1724 * until we know the whole operation will work.
1725 */
8cd0a023 1726 if (ondisk->parent == 0) {
df2ccbac
MD
1727 parent = hammer_alloc_btree(cursor->trans, leaf->node_offset,
1728 &error);
427e5fc6 1729 if (parent == NULL)
6a37e7e4 1730 goto done;
8cd0a023 1731 hammer_lock_ex(&parent->lock);
36f82b23 1732 hammer_modify_node_noundo(cursor->trans, parent);
8cd0a023
MD
1733 ondisk = parent->ondisk;
1734 ondisk->count = 1;
1735 ondisk->parent = 0;
a56cb012 1736 ondisk->mirror_tid = leaf->ondisk->mirror_tid;
8cd0a023 1737 ondisk->type = HAMMER_BTREE_TYPE_INTERNAL;
47197d71 1738 ondisk->elms[0].base = hmp->root_btree_beg;
fe7678ee 1739 ondisk->elms[0].base.btype = leaf->ondisk->type;
8cd0a023 1740 ondisk->elms[0].internal.subtree_offset = leaf->node_offset;
47197d71 1741 ondisk->elms[1].base = hmp->root_btree_end;
fe7678ee 1742 /* ondisk->elms[1].base.btype = not used */
10a5d1ba 1743 hammer_modify_node_done(parent);
427e5fc6 1744 made_root = 1;
8cd0a023 1745 parent_index = 0; /* insertion point in parent */
427e5fc6
MD
1746 } else {
1747 made_root = 0;
8cd0a023
MD
1748 parent = cursor->parent;
1749 parent_index = cursor->parent_index;
427e5fc6 1750 }
427e5fc6 1751
df2ccbac
MD
1752 /*
1753 * Calculate a hint for the allocation of the new B-Tree leaf node.
1754 * For now just try to localize it within the same bigblock as
1755 * the current leaf.
1756 *
1757 * If the insertion point is at the end of the leaf we recognize a
1758 * likely append sequence of some sort (data, meta-data, inodes,
1759 * whatever). Set the hint to zero to allocate out of linear space
1760 * instead of trying to completely fill previously hinted space.
1761 *
1762 * This also sets the stage for recursive splits to localize using
1763 * the new space.
1764 */
1765 ondisk = leaf->ondisk;
1766 if (cursor->index == ondisk->count)
1767 hint = 0;
1768 else
1769 hint = leaf->node_offset;
1770
427e5fc6
MD
1771 /*
1772 * Split leaf into new_leaf at the split point. Select a separator
1773 * value in-between the two leafs but with a bent towards the right
1774 * leaf since comparisons use an 'elm >= separator' inequality.
1775 *
1776 * L L L L L L L L
1777 *
1778 * x x P x x
1779 * s S S s
1780 * / \
1781 * L L L L L L L L
1782 */
df2ccbac 1783 new_leaf = hammer_alloc_btree(cursor->trans, hint, &error);
427e5fc6 1784 if (new_leaf == NULL) {
8cd0a023
MD
1785 if (made_root) {
1786 hammer_unlock(&parent->lock);
36f82b23 1787 hammer_delete_node(cursor->trans, parent);
8cd0a023
MD
1788 hammer_rel_node(parent);
1789 }
6a37e7e4 1790 goto done;
427e5fc6 1791 }
8cd0a023 1792 hammer_lock_ex(&new_leaf->lock);
427e5fc6
MD
1793
1794 /*
36f82b23
MD
1795 * Create the new node and copy the leaf elements from the split
1796 * point on to the new node.
427e5fc6 1797 */
36f82b23
MD
1798 hammer_modify_node_all(cursor->trans, leaf);
1799 hammer_modify_node_noundo(cursor->trans, new_leaf);
8cd0a023
MD
1800 ondisk = leaf->ondisk;
1801 elm = &ondisk->elms[split];
1802 bcopy(elm, &new_leaf->ondisk->elms[0], (ondisk->count - split) * esize);
1803 new_leaf->ondisk->count = ondisk->count - split;
1804 new_leaf->ondisk->parent = parent->node_offset;
1805 new_leaf->ondisk->type = HAMMER_BTREE_TYPE_LEAF;
a56cb012 1806 new_leaf->ondisk->mirror_tid = ondisk->mirror_tid;
8cd0a023 1807 KKASSERT(ondisk->type == new_leaf->ondisk->type);
10a5d1ba 1808 hammer_modify_node_done(new_leaf);
b3bad96f 1809 hammer_cursor_split_node(leaf, new_leaf, split);
427e5fc6
MD
1810
1811 /*
8cd0a023
MD
1812 * Cleanup the original node. Because this is a leaf node and
1813 * leaf nodes do not have a right-hand boundary, there
c0ade690
MD
1814 * aren't any special edge cases to clean up. We just fixup the
1815 * count.
427e5fc6 1816 */
c0ade690 1817 ondisk->count = split;
427e5fc6
MD
1818
1819 /*
1820 * Insert the separator into the parent, fixup the parent's
1821 * reference to the original node, and reference the new node.
1822 * The separator is P.
1823 *
1824 * Remember that base.count does not include the right-hand boundary.
1825 * We are copying parent_index+1 to parent_index+2, not +0 to +1.
1826 */
36f82b23 1827 hammer_modify_node_all(cursor->trans, parent);
8cd0a023 1828 ondisk = parent->ondisk;
36f82b23 1829 KKASSERT(split != 0);
d26d0ae9 1830 KKASSERT(ondisk->count != HAMMER_BTREE_INT_ELMS);
8cd0a023 1831 parent_elm = &ondisk->elms[parent_index+1];
d26d0ae9
MD
1832 bcopy(parent_elm, parent_elm + 1,
1833 (ondisk->count - parent_index) * esize);
eaeff70d 1834
47197d71 1835 hammer_make_separator(&elm[-1].base, &elm[0].base, &parent_elm->base);
fe7678ee 1836 parent_elm->internal.base.btype = new_leaf->ondisk->type;
8cd0a023 1837 parent_elm->internal.subtree_offset = new_leaf->node_offset;
a56cb012 1838 parent_elm->internal.mirror_tid = new_leaf->ondisk->mirror_tid;
b3deaf57 1839 mid_boundary = &parent_elm->base;
76376933 1840 ++ondisk->count;
10a5d1ba 1841 hammer_modify_node_done(parent);
b3bad96f 1842 hammer_cursor_inserted_element(parent, parent_index + 1);
427e5fc6 1843
fe7678ee 1844 /*
47197d71 1845 * The filesystem's root B-Tree pointer may have to be updated.
427e5fc6
MD
1846 */
1847 if (made_root) {
47197d71
MD
1848 hammer_volume_t volume;
1849
1850 volume = hammer_get_root_volume(hmp, &error);
1851 KKASSERT(error == 0);
1852
e8599db1
MD
1853 hammer_modify_volume_field(cursor->trans, volume,
1854 vol0_btree_root);
47197d71 1855 volume->ondisk->vol0_btree_root = parent->node_offset;
10a5d1ba 1856 hammer_modify_volume_done(volume);
8cd0a023
MD
1857 leaf->ondisk->parent = parent->node_offset;
1858 if (cursor->parent) {
1859 hammer_unlock(&cursor->parent->lock);
1860 hammer_rel_node(cursor->parent);
1861 }
1862 cursor->parent = parent; /* lock'd and ref'd */
47197d71 1863 hammer_rel_volume(volume, 0);
427e5fc6 1864 }
10a5d1ba 1865 hammer_modify_node_done(leaf);
8cd0a023 1866
427e5fc6
MD
1867 /*
1868 * Ok, now adjust the cursor depending on which element the original
1869 * index was pointing at. If we are >= the split point the push node
1870 * is now in the new node.
1871 *
b3deaf57
MD
1872 * NOTE: If we are at the split point itself we need to select the
1873 * old or new node based on where key_beg's insertion point will be.
1874 * If we pick the wrong side the inserted element will wind up in
1875 * the wrong leaf node and outside that node's bounds.
427e5fc6 1876 */
b3deaf57
MD
1877 if (cursor->index > split ||
1878 (cursor->index == split &&
1879 hammer_btree_cmp(&cursor->key_beg, mid_boundary) >= 0)) {
8cd0a023 1880 cursor->parent_index = parent_index + 1;
427e5fc6 1881 cursor->index -= split;
8cd0a023
MD
1882 hammer_unlock(&cursor->node->lock);
1883 hammer_rel_node(cursor->node);
1884 cursor->node = new_leaf;
1885 } else {
1886 cursor->parent_index = parent_index;
1887 hammer_unlock(&new_leaf->lock);
1888 hammer_rel_node(new_leaf);
427e5fc6 1889 }
76376933
MD
1890
1891 /*
1892 * Fixup left and right bounds
1893 */
1894 parent_elm = &parent->ondisk->elms[cursor->parent_index];
fbc6e32a
MD
1895 cursor->left_bound = &parent_elm[0].internal.base;
1896 cursor->right_bound = &parent_elm[1].internal.base;
eaeff70d
MD
1897
1898 /*
47197d71 1899 * Assert that the bounds are correct.
eaeff70d 1900 */
b3deaf57
MD
1901 KKASSERT(hammer_btree_cmp(cursor->left_bound,
1902 &cursor->node->ondisk->elms[0].leaf.base) <= 0);
1903 KKASSERT(hammer_btree_cmp(cursor->right_bound,
47197d71 1904 &cursor->node->ondisk->elms[cursor->node->ondisk->count-1].leaf.base) > 0);
36f82b23
MD
1905 KKASSERT(hammer_btree_cmp(cursor->left_bound, &cursor->key_beg) <= 0);
1906 KKASSERT(hammer_btree_cmp(cursor->right_bound, &cursor->key_beg) > 0);
76376933 1907
6a37e7e4
MD
1908done:
1909 hammer_cursor_downgrade(cursor);
1910 return (error);
427e5fc6
MD
1911}
1912
adf01747
MD
1913#if 0
1914
32c90105
MD
1915/*
1916 * Recursively correct the right-hand boundary's create_tid to (tid) as
1917 * long as the rest of the key matches. We have to recurse upward in
1918 * the tree as well as down the left side of each parent's right node.
1919 *
1920 * Return EDEADLK if we were only partially successful, forcing the caller
1921 * to try again. The original cursor is not modified. This routine can
1922 * also fail with EDEADLK if it is forced to throw away a portion of its
1923 * record history.
1924 *
1925 * The caller must pass a downgraded cursor to us (otherwise we can't dup it).
1926 */
1927struct hammer_rhb {
1928 TAILQ_ENTRY(hammer_rhb) entry;
1929 hammer_node_t node;
1930 int index;
1931};
1932
1933TAILQ_HEAD(hammer_rhb_list, hammer_rhb);
1934
1935int
1936hammer_btree_correct_rhb(hammer_cursor_t cursor, hammer_tid_t tid)
1937{
bac808fe 1938 struct hammer_mount *hmp;
32c90105
MD
1939 struct hammer_rhb_list rhb_list;
1940 hammer_base_elm_t elm;
1941 hammer_node_t orig_node;
1942 struct hammer_rhb *rhb;
1943 int orig_index;
1944 int error;
1945
1946 TAILQ_INIT(&rhb_list);
bac808fe 1947 hmp = cursor->trans->hmp;
32c90105
MD
1948
1949 /*
1950 * Save our position so we can restore it on return. This also
1951 * gives us a stable 'elm'.
1952 */
1953 orig_node = cursor->node;
1954 hammer_ref_node(orig_node);
1955 hammer_lock_sh(&orig_node->lock);
1956 orig_index = cursor->index;
1957 elm = &orig_node->ondisk->elms[orig_index].base;
1958
1959 /*
1960 * Now build a list of parents going up, allocating a rhb
1961 * structure for each one.
1962 */
1963 while (cursor->parent) {
1964 /*
1965 * Stop if we no longer have any right-bounds to fix up
1966 */
1967 if (elm->obj_id != cursor->right_bound->obj_id ||
1968 elm->rec_type != cursor->right_bound->rec_type ||
1969 elm->key != cursor->right_bound->key) {
1970 break;
1971 }
1972
1973 /*
1974 * Stop if the right-hand bound's create_tid does not
47197d71 1975 * need to be corrected.
32c90105
MD
1976 */
1977 if (cursor->right_bound->create_tid >= tid)
1978 break;
1979
bac808fe 1980 rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO);
32c90105
MD
1981 rhb->node = cursor->parent;
1982 rhb->index = cursor->parent_index;
1983 hammer_ref_node(rhb->node);
1984 hammer_lock_sh(&rhb->node->lock);
1985 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
1986
1987 hammer_cursor_up(cursor);
1988 }
1989
1990 /*
1991 * now safely adjust the right hand bound for each rhb. This may
1992 * also require taking the right side of the tree and iterating down
1993 * ITS left side.
1994 */
1995 error = 0;
1996 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
1997 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
32c90105
MD
1998 if (error)
1999 break;
2000 TAILQ_REMOVE(&rhb_list, rhb, entry);
2001 hammer_unlock(&rhb->node->lock);
2002 hammer_rel_node(rhb->node);
bac808fe 2003 kfree(rhb, hmp->m_misc);
32c90105
MD
2004
2005 switch (cursor->node->ondisk->type) {
2006 case HAMMER_BTREE_TYPE_INTERNAL:
2007 /*
2008 * Right-boundary for parent at internal node
2009 * is one element to the right of the element whos
2010 * right boundary needs adjusting. We must then
2011 * traverse down the left side correcting any left
2012 * bounds (which may now be too far to the left).
2013 */
2014 ++cursor->index;
2015 error = hammer_btree_correct_lhb(cursor, tid);
2016 break;
32c90105
MD
2017 default:
2018 panic("hammer_btree_correct_rhb(): Bad node type");
2019 error = EINVAL;
2020 break;
2021 }
2022 }
2023
2024 /*
2025 * Cleanup
2026 */
2027 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
2028 TAILQ_REMOVE(&rhb_list, rhb, entry);
2029 hammer_unlock(&rhb->node->lock);
2030 hammer_rel_node(rhb->node);
bac808fe 2031 kfree(rhb, hmp->m_misc);
32c90105
MD
2032 }
2033 error = hammer_cursor_seek(cursor, orig_node, orig_index);
2034 hammer_unlock(&orig_node->lock);
2035 hammer_rel_node(orig_node);
2036 return (error);
2037}
2038
2039/*
2040 * Similar to rhb (in fact, rhb calls lhb), but corrects the left hand
2041 * bound going downward starting at the current cursor position.
2042 *
2043 * This function does not restore the cursor after use.
2044 */
2045int
2046hammer_btree_correct_lhb(hammer_cursor_t cursor, hammer_tid_t tid)
2047{
2048 struct hammer_rhb_list rhb_list;
2049 hammer_base_elm_t elm;
2050 hammer_base_elm_t cmp;
2051 struct hammer_rhb *rhb;
bac808fe 2052 struct hammer_mount *hmp;
32c90105
MD
2053 int error;
2054
2055 TAILQ_INIT(&rhb_list);
bac808fe 2056 hmp = cursor->trans->hmp;
32c90105
MD
2057
2058 cmp = &cursor->node->ondisk->elms[cursor->index].base;
2059
2060 /*
2061 * Record the node and traverse down the left-hand side for all
2062 * matching records needing a boundary correction.
2063 */
2064 error = 0;
2065 for (;;) {
bac808fe 2066 rhb = kmalloc(sizeof(*rhb), hmp->m_misc, M_WAITOK|M_ZERO);
32c90105
MD
2067 rhb->node = cursor->node;
2068 rhb->index = cursor->index;
2069 hammer_ref_node(rhb->node);
2070 hammer_lock_sh(&rhb->node->lock);
2071 TAILQ_INSERT_HEAD(&rhb_list, rhb, entry);
2072
2073 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
2074 /*
2075 * Nothing to traverse down if we are at the right
2076 * boundary of an internal node.
2077 */
2078 if (cursor->index == cursor->node->ondisk->count)
2079 break;
2080 } else {
2081 elm = &cursor->node->ondisk->elms[cursor->index].base;
2082 if (elm->btype == HAMMER_BTREE_TYPE_RECORD)
2083 break;
47197d71 2084 panic("Illegal leaf record type %02x", elm->btype);
32c90105
MD
2085 }
2086 error = hammer_cursor_down(cursor);
2087 if (error)
2088 break;
2089
2090 elm = &cursor->node->ondisk->elms[cursor->index].base;
2091 if (elm->obj_id != cmp->obj_id ||
2092 elm->rec_type != cmp->rec_type ||
2093 elm->key != cmp->key) {
2094 break;
2095 }
2096 if (elm->create_tid >= tid)
2097 break;
2098
2099 }
2100
2101 /*
2102 * Now we can safely adjust the left-hand boundary from the bottom-up.
2103 * The last element we remove from the list is the caller's right hand
2104 * boundary, which must also be adjusted.
2105 */
2106 while (error == 0 && (rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
2107 error = hammer_cursor_seek(cursor, rhb->node, rhb->index);
2108 if (error)
2109 break;
2110 TAILQ_REMOVE(&rhb_list, rhb, entry);
2111 hammer_unlock(&rhb->node->lock);
2112 hammer_rel_node(rhb->node);
bac808fe 2113 kfree(rhb, hmp->m_misc);
32c90105
MD
2114
2115 elm = &cursor->node->ondisk->elms[cursor->index].base;
2116 if (cursor->node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
36f82b23 2117 hammer_modify_node(cursor->trans, cursor->node,
19619882
MD
2118 &elm->create_tid,
2119 sizeof(elm->create_tid));
32c90105 2120 elm->create_tid = tid;
10a5d1ba 2121 hammer_modify_node_done(cursor->node);
32c90105
MD
2122 } else {
2123 panic("hammer_btree_correct_lhb(): Bad element type");
2124 }
2125 }
2126
2127 /*
2128 * Cleanup
2129 */
2130 while ((rhb = TAILQ_FIRST(&rhb_list)) != NULL) {
2131 TAILQ_REMOVE(&rhb_list, rhb, entry);
2132 hammer_unlock(&rhb->node->lock);
2133 hammer_rel_node(rhb->node);
bac808fe 2134 kfree(rhb, hmp->m_misc);
32c90105
MD
2135 }
2136 return (error);
2137}
2138
adf01747
MD
2139#endif
2140
427e5fc6 2141/*
f36a9737
MD
2142 * Attempt to remove the locked, empty or want-to-be-empty B-Tree node at
2143 * (cursor->node). Returns 0 on success, EDEADLK if we could not complete
2144 * the operation due to a deadlock, or some other error.
8cd0a023 2145 *
5c8d05e2
MD
2146 * This routine is initially called with an empty leaf and may be
2147 * recursively called with single-element internal nodes.
b3deaf57 2148 *
c82af904
MD
2149 * It should also be noted that when removing empty leaves we must be sure
2150 * to test and update mirror_tid because another thread may have deadlocked
5fa5c92f 2151 * against us (or someone) trying to propagate it up and cannot retry once
c82af904
MD
2152 * the node has been deleted.
2153 *
f36a9737
MD
2154 * On return the cursor may end up pointing to an internal node, suitable
2155 * for further iteration but not for an immediate insertion or deletion.
8cd0a023 2156 */
f36a9737 2157static int
46fe7ae1 2158btree_remove(hammer_cursor_t cursor)
8cd0a023
MD
2159{
2160 hammer_node_ondisk_t ondisk;
195c19a1 2161 hammer_btree_elm_t elm;
195c19a1 2162 hammer_node_t node;
8cd0a023 2163 hammer_node_t parent;
fe7678ee 2164 const int esize = sizeof(*elm);
8cd0a023 2165 int error;
8cd0a023 2166
fe7678ee
MD
2167 node = cursor->node;
2168
47197d71
MD
2169 /*
2170 * When deleting the root of the filesystem convert it to
2171 * an empty leaf node. Internal nodes cannot be empty.
2172 */
c82af904
MD
2173 ondisk = node->ondisk;
2174 if (ondisk->parent == 0) {
f36a9737 2175 KKASSERT(cursor->parent == NULL);
36f82b23 2176 hammer_modify_node_all(cursor->trans, node);
c82af904 2177 KKASSERT(ondisk == node->ondisk);
195c19a1
MD
2178 ondisk->type = HAMMER_BTREE_TYPE_LEAF;
2179 ondisk->count = 0;
10a5d1ba 2180 hammer_modify_node_done(node);
b3deaf57 2181 cursor->index = 0;
47197d71 2182 return(0);
8cd0a023
MD
2183 }
2184
c82af904
MD
2185 parent = cursor->parent;
2186
8cd0a023 2187 /*
f36a9737
MD
2188 * Attempt to remove the parent's reference to the child. If the
2189 * parent would become empty we have to recurse. If we fail we
2190 * leave the parent pointing to an empty leaf node.
5c8d05e2
MD
2191 *
2192 * We have to recurse successfully before we can delete the internal
2193 * node as it is illegal to have empty internal nodes. Even though
2194 * the operation may be aborted we must still fixup any unlocked
2195 * cursors as if we had deleted the element prior to recursing
2196 * (by calling hammer_cursor_deleted_element()) so those cursors
2197 * are properly forced up the chain by the recursion.
8cd0a023 2198 */
f36a9737
MD
2199 if (parent->ondisk->count == 1) {
2200 /*
2201 * This special cursor_up_locked() call leaves the original
2202 * node exclusively locked and referenced, leaves the
2203 * original parent locked (as the new node), and locks the
2204 * new parent. It can return EDEADLK.
f3a4893b
MD
2205 *
2206 * We cannot call hammer_cursor_removed_node() until we are
2207 * actually able to remove the node. If we did then tracked
2208 * cursors in the middle of iterations could be repointed
2209 * to a parent node. If this occurs they could end up
2210 * scanning newly inserted records into the node (that could
2211 * not be deleted) when they push down again.
2212 *
2213 * Due to the way the recursion works the final parent is left
2214 * in cursor->parent after the recursion returns. Each
2215 * layer on the way back up is thus able to call
2216 * hammer_cursor_removed_node() and 'jump' the node up to
2217 * the (same) final parent.
2218 *
2219 * NOTE! The local variable 'parent' is invalid after we
2220 * call hammer_cursor_up_locked().
f36a9737
MD
2221 */
2222 error = hammer_cursor_up_locked(cursor);
f3a4893b
MD
2223 parent = NULL;
2224
f36a9737 2225 if (error == 0) {
5c8d05e2 2226 hammer_cursor_deleted_element(cursor->node, 0);
f36a9737
MD
2227 error = btree_remove(cursor);
2228 if (error == 0) {
f3a4893b
MD
2229 hammer_cursor_removed_node(
2230 node, cursor->parent,
2231 cursor->parent_index);
f36a9737
MD
2232 hammer_modify_node_all(cursor->trans, node);
2233 ondisk = node->ondisk;
2234 ondisk->type = HAMMER_BTREE_TYPE_DELETED;
2235 ondisk->count = 0;
2236 hammer_modify_node_done(node);
2237 hammer_flush_node(node);
2238 hammer_delete_node(cursor->trans, node);
2239 } else {
3214ade6
MD
2240 /*
2241 * Defer parent removal because we could not
2242 * get the lock, just let the leaf remain
2243 * empty.
2244 */
2245 /**/
f36a9737
MD
2246 }
2247 hammer_unlock(&node->lock);
2248 hammer_rel_node(node);
2249 } else {
3214ade6
MD
2250 /*
2251 * Defer parent removal because we could not
2252 * get the lock, just let the leaf remain
2253 * empty.
2254 */
2255 /**/
f36a9737
MD
2256 }
2257 } else {
2258 KKASSERT(parent->ondisk->count > 1);
6a37e7e4 2259
f36a9737
MD
2260 hammer_modify_node_all(cursor->trans, parent);
2261 ondisk = parent->ondisk;
2262 KKASSERT(ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
c82af904 2263
f36a9737
MD
2264 elm = &ondisk->elms[cursor->parent_index];
2265 KKASSERT(elm->internal.subtree_offset == node->node_offset);
2266 KKASSERT(ondisk->count > 0);
4c038e17
MD
2267
2268 /*
2269 * We must retain the highest mirror_tid. The deleted
2270 * range is now encompassed by the element to the left.
2271 * If we are already at the left edge the new left edge
2272 * inherits mirror_tid.
2273 *
2274 * Note that bounds of the parent to our parent may create
2275 * a gap to the left of our left-most node or to the right
2276 * of our right-most node. The gap is silently included
2277 * in the mirror_tid's area of effect from the point of view
2278 * of the scan.
2279 */
2280 if (cursor->parent_index) {
2281 if (elm[-1].internal.mirror_tid <
2282 elm[0].internal.mirror_tid) {
2283 elm[-1].internal.mirror_tid =
2284 elm[0].internal.mirror_tid;
2285 }
2286 } else {
2287 if (elm[1].internal.mirror_tid <
2288 elm[0].internal.mirror_tid) {
2289 elm[1].internal.mirror_tid =
2290 elm[0].internal.mirror_tid;
2291 }
2292 }
2293
2294 /*
f3a4893b
MD
2295 * Delete the subtree reference in the parent. Include
2296 * boundary element at end.
4c038e17 2297 */
f36a9737
MD
2298 bcopy(&elm[1], &elm[0],
2299 (ondisk->count - cursor->parent_index) * esize);
2300 --ondisk->count;
10a5d1ba 2301 hammer_modify_node_done(parent);
f3a4893b 2302 hammer_cursor_removed_node(node, parent, cursor->parent_index);
6c1f89f4 2303 hammer_cursor_deleted_element(parent, cursor->parent_index);
f36a9737
MD
2304 hammer_flush_node(node);
2305 hammer_delete_node(cursor->trans, node);
6a37e7e4 2306
f36a9737
MD
2307 /*
2308 * cursor->node is invalid, cursor up to make the cursor
2309 * valid again.
2310 */
2311 error = hammer_cursor_up(cursor);
6a37e7e4 2312 }
f36a9737 2313 return (error);
6a37e7e4
MD
2314}
2315
602c6cb8
MD
2316/*
2317 * Propagate cursor->trans->tid up the B-Tree starting at the current
2318 * cursor position using pseudofs info gleaned from the passed inode.
2319 *
2320 * The passed inode has no relationship to the cursor position other
2321 * then being in the same pseudofs as the insertion or deletion we
2322 * are propagating the mirror_tid for.
c9ce54d6
MD
2323 *
2324 * WARNING! Because we push and pop the passed cursor, it may be
2325 * modified by other B-Tree operations while it is unlocked
2326 * and things like the node & leaf pointers, and indexes might
2327 * change.
602c6cb8
MD
2328 */
2329void
4c038e17
MD
2330hammer_btree_do_propagation(hammer_cursor_t cursor,
2331 hammer_pseudofs_inmem_t pfsm,
602c6cb8
MD
2332 hammer_btree_leaf_elm_t leaf)
2333{
adf01747
MD
2334 hammer_cursor_t ncursor;
2335 hammer_tid_t mirror_tid;
602c6cb8
MD
2336 int error;
2337
2338 /*
732a1697
MD
2339 * We do not propagate a mirror_tid if the filesystem was mounted
2340 * in no-mirror mode.
602c6cb8 2341 */
732a1697 2342 if (cursor->trans->hmp->master_id < 0)
602c6cb8 2343 return;
602c6cb8 2344
adf01747
MD
2345 /*
2346 * This is a bit of a hack because we cannot deadlock or return
2347 * EDEADLK here. The related operation has already completed and
2348 * we must propagate the mirror_tid now regardless.
2349 *
2350 * Generate a new cursor which inherits the original's locks and
2351 * unlock the original. Use the new cursor to propagate the
2352 * mirror_tid. Then clean up the new cursor and reacquire locks
2353 * on the original.
2354 *
2355 * hammer_dup_cursor() cannot dup locks. The dup inherits the
2356 * original's locks and the original is tracked and must be
2357 * re-locked.
2358 */
2359 mirror_tid = cursor->node->ondisk->mirror_tid;
a56cb012 2360 KKASSERT(mirror_tid != 0);
3f43fb33 2361 ncursor = hammer_push_cursor(cursor);
adf01747
MD
2362 error = hammer_btree_mirror_propagate(ncursor, mirror_tid);
2363 KKASSERT(error == 0);
3f43fb33 2364 hammer_pop_cursor(cursor, ncursor);
c9ce54d6 2365 /* WARNING: cursor's leaf pointer may change after pop */
602c6cb8
MD
2366}
2367
2368
c82af904
MD
2369/*
2370 * Propagate a mirror TID update upwards through the B-Tree to the root.
2371 *
2372 * A locked internal node must be passed in. The node will remain locked
2373 * on return.
2374 *
2375 * This function syncs mirror_tid at the specified internal node's element,
2376 * adjusts the node's aggregation mirror_tid, and then recurses upwards.
2377 */
602c6cb8 2378static int
adf01747 2379hammer_btree_mirror_propagate(hammer_cursor_t cursor, hammer_tid_t mirror_tid)
c82af904
MD
2380{
2381 hammer_btree_internal_elm_t elm;
adf01747 2382 hammer_node_t node;
c82af904
MD
2383 int error;
2384
adf01747
MD
2385 for (;;) {
2386 error = hammer_cursor_up(cursor);
2387 if (error == 0)
2388 error = hammer_cursor_upgrade(cursor);
2389 while (error == EDEADLK) {
2390 hammer_recover_cursor(cursor);
2391 error = hammer_cursor_upgrade(cursor);
2392 }
2393 if (error)
2394 break;
2395 node = cursor->node;
2396 KKASSERT (node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
c82af904 2397
adf01747
MD
2398 /*
2399 * Adjust the node's element
2400 */
2401 elm = &node->ondisk->elms[cursor->index].internal;
2402 if (elm->mirror_tid >= mirror_tid)
2403 break;
2404 hammer_modify_node(cursor->trans, node, &elm->mirror_tid,
2405 sizeof(elm->mirror_tid));
2406 elm->mirror_tid = mirror_tid;
2407 hammer_modify_node_done(node);
02325004
MD
2408 if (hammer_debug_general & 0x0002) {
2409 kprintf("mirror_propagate: propagate "
2410 "%016llx @%016llx:%d\n",
973c11b9
MD
2411 (long long)mirror_tid,
2412 (long long)node->node_offset,
2413 cursor->index);
02325004
MD
2414 }
2415
c82af904 2416
adf01747
MD
2417 /*
2418 * Adjust the node's mirror_tid aggregator
2419 */
2420 if (node->ondisk->mirror_tid >= mirror_tid)
2421 return(0);
2422 hammer_modify_node_field(cursor->trans, node, mirror_tid);
2423 node->ondisk->mirror_tid = mirror_tid;
2424 hammer_modify_node_done(node);
02325004
MD
2425 if (hammer_debug_general & 0x0002) {
2426 kprintf("mirror_propagate: propagate "
2427 "%016llx @%016llx\n",
973c11b9
MD
2428 (long long)mirror_tid,
2429 (long long)node->node_offset);
02325004 2430 }
c82af904 2431 }
adf01747
MD
2432 if (error == ENOENT)
2433 error = 0;
c82af904
MD
2434 return(error);
2435}
2436
2437hammer_node_t
82010f9f
MD
2438hammer_btree_get_parent(hammer_transaction_t trans, hammer_node_t node,
2439 int *parent_indexp, int *errorp, int try_exclusive)
c82af904
MD
2440{
2441 hammer_node_t parent;
2442 hammer_btree_elm_t elm;
2443 int i;
2444
2445 /*
2446 * Get the node
2447 */
82010f9f 2448 parent = hammer_get_node(trans, node->ondisk->parent, 0, errorp);
c82af904
MD
2449 if (*errorp) {
2450 KKASSERT(parent == NULL);
2451 return(NULL);
2452 }
2453 KKASSERT ((parent->flags & HAMMER_NODE_DELETED) == 0);
2454
2455 /*
2456 * Lock the node
2457 */
2458 if (try_exclusive) {
2459 if (hammer_lock_ex_try(&parent->lock)) {
2460 hammer_rel_node(parent);
2461 *errorp = EDEADLK;
2462 return(NULL);
2463 }
2464 } else {
2465 hammer_lock_sh(&parent->lock);
2466 }
2467
2468 /*
2469 * Figure out which element in the parent is pointing to the
2470 * child.
2471 */
2472 if (node->ondisk->count) {
2473 i = hammer_btree_search_node(&node->ondisk->elms[0].base,
2474 parent->ondisk);
2475 } else {
2476 i = 0;
2477 }
2478 while (i < parent->ondisk->count) {
2479 elm = &parent->ondisk->elms[i];
2480 if (elm->internal.subtree_offset == node->node_offset)
2481 break;
2482 ++i;
2483 }
2484 if (i == parent->ondisk->count) {
2485 hammer_unlock(&parent->lock);
2486 panic("Bad B-Tree link: parent %p node %p\n", parent, node);
2487 }
2488 *parent_indexp = i;
2489 KKASSERT(*errorp == 0);
2490 return(parent);
2491}
2492
7f7c1f84 2493/*
fe7678ee
MD
2494 * The element (elm) has been moved to a new internal node (node).
2495 *
2496 * If the element represents a pointer to an internal node that node's
2497 * parent must be adjusted to the element's new location.
2498 *
6a37e7e4 2499 * XXX deadlock potential here with our exclusive locks
7f7c1f84 2500 */
7f7c1f84 2501int
36f82b23
MD
2502btree_set_parent(hammer_transaction_t trans, hammer_node_t node,
2503 hammer_btree_elm_t elm)
7f7c1f84 2504{
7f7c1f84
MD
2505 hammer_node_t child;
2506 int error;
2507
2508 error = 0;
2509
fe7678ee 2510 switch(elm->base.btype) {
7f7c1f84 2511 case HAMMER_BTREE_TYPE_INTERNAL:
fe7678ee 2512 case HAMMER_BTREE_TYPE_LEAF:
82010f9f 2513 child = hammer_get_node(trans, elm->internal.subtree_offset,
19619882 2514 0, &error);
7f7c1f84 2515 if (error == 0) {
c9b9e29d 2516 hammer_modify_node_field(trans, child, parent);
7f7c1f84 2517 child->ondisk->parent = node->node_offset;
10a5d1ba 2518 hammer_modify_node_done(child);
7f7c1f84
MD
2519 hammer_rel_node(child);
2520 }
2521 break;
7f7c1f84 2522 default:
fe7678ee 2523 break;
7f7c1f84
MD
2524 }
2525 return(error);
2526}
2527
1775b6a0
MD
2528/*
2529 * Initialize the root of a recursive B-Tree node lock list structure.
2530 */
2531void
2532hammer_node_lock_init(hammer_node_lock_t parent, hammer_node_t node)
2533{
2534 TAILQ_INIT(&parent->list);
2535 parent->parent = NULL;
2536 parent->node = node;
2537 parent->index = -1;
2538 parent->count = node->ondisk->count;
2539 parent->copy = NULL;
2540 parent->flags = 0;
2541}
2542
b33e2cc0
MD
2543/*
2544 * Exclusively lock all the children of node. This is used by the split
2545 * code to prevent anyone from accessing the children of a cursor node
2546 * while we fix-up its parent offset.
2547 *
2548 * If we don't lock the children we can really mess up cursors which block
2549 * trying to cursor-up into our node.
2550 *
b33e2cc0
MD
2551 * On failure EDEADLK (or some other error) is returned. If a deadlock
2552 * error is returned the cursor is adjusted to block on termination.
1775b6a0
MD
2553 *
2554 * The caller is responsible for managing parent->node, the root's node
2555 * is usually aliased from a cursor.
b33e2cc0
MD
2556 */
2557int
1775b6a0
MD
2558hammer_btree_lock_children(hammer_cursor_t cursor, int depth,
2559 hammer_node_lock_t parent)
b33e2cc0
MD
2560{
2561 hammer_node_t node;
1775b6a0 2562 hammer_node_lock_t item;
b33e2cc0
MD
2563 hammer_node_ondisk_t ondisk;
2564 hammer_btree_elm_t elm;
b33e2cc0 2565 hammer_node_t child;
bac808fe 2566 struct hammer_mount *hmp;
b33e2cc0
MD
2567 int error;
2568 int i;
2569
1775b6a0 2570 node = parent->node;
b33e2cc0
MD
2571 ondisk = node->ondisk;
2572 error = 0;
bac808fe 2573 hmp = cursor->trans->hmp;
7bc5b8c2
MD
2574
2575 /*
2576 * We really do not want to block on I/O with exclusive locks held,
1775b6a0
MD
2577 * pre-get the children before trying to lock the mess. This is
2578 * only done one-level deep for now.
7bc5b8c2
MD
2579 */
2580 for (i = 0; i < ondisk->count; ++i) {
cb51be26 2581 ++hammer_stats_btree_elements;
7bc5b8c2
MD
2582 elm = &ondisk->elms[i];
2583 if (elm->base.btype != HAMMER_BTREE_TYPE_LEAF &&
2584 elm->base.btype != HAMMER_BTREE_TYPE_INTERNAL) {
2585 continue;
2586 }
82010f9f 2587 child = hammer_get_node(cursor->trans,
7bc5b8c2
MD
2588 elm->internal.subtree_offset,
2589 0, &error);
2590 if (child)
2591 hammer_rel_node(child);
2592 }
2593
2594 /*
2595 * Do it for real
2596 */
b33e2cc0 2597 for (i = 0; error == 0 && i < ondisk->count; ++i) {
cb51be26 2598 ++hammer_stats_btree_elements;
b33e2cc0
MD
2599 elm = &ondisk->elms[i];
2600
b33e2cc0
MD
2601 switch(elm->base.btype) {
2602 case HAMMER_BTREE_TYPE_INTERNAL:
2603 case HAMMER_BTREE_TYPE_LEAF:
f36a9737 2604 KKASSERT(elm->internal.subtree_offset != 0);
82010f9f 2605 child = hammer_get_node(cursor->trans,
b33e2cc0 2606 elm->internal.subtree_offset,
19619882 2607 0, &error);
b33e2cc0 2608 break;
b33e2cc0 2609 default:
47197d71 2610 child = NULL;
b33e2cc0
MD
2611 break;
2612 }
2613 if (child) {
2614 if (hammer_lock_ex_try(&child->lock) != 0) {
2615 if (cursor->deadlk_node == NULL) {
1ff9f58e 2616 cursor->deadlk_node = child;
b33e2cc0
MD
2617 hammer_ref_node(cursor->deadlk_node);
2618 }
2619 error = EDEADLK;
a84a197d 2620 hammer_rel_node(child);
b33e2cc0 2621 } else {
1775b6a0
MD
2622 item = kmalloc(sizeof(*item), hmp->m_misc,
2623 M_WAITOK|M_ZERO);
2624 TAILQ_INSERT_TAIL(&parent->list, item, entry);
2625 TAILQ_INIT(&item->list);
2626 item->parent = parent;
b33e2cc0 2627 item->node = child;
1775b6a0
MD
2628 item->index = i;
2629 item->count = child->ondisk->count;
2630
2631 /*
2632 * Recurse (used by the rebalancing code)
2633 */
2634 if (depth > 1 && elm->base.btype == HAMMER_BTREE_TYPE_INTERNAL) {
2635 error = hammer_btree_lock_children(
2636 cursor,
2637 depth - 1,
2638 item);
2639 }
b33e2cc0
MD
2640 }
2641 }
2642 }
2643 if (error)
1775b6a0 2644 hammer_btree_unlock_children(cursor, parent);
b33e2cc0
MD
2645 return(error);
2646}
2647
1775b6a0
MD
2648/*
2649 * Create an in-memory copy of all B-Tree nodes listed, recursively,
2650 * including the parent.
2651 */
2652void
2653hammer_btree_lock_copy(hammer_cursor_t cursor, hammer_node_lock_t parent)
2654{
2655 hammer_mount_t hmp = cursor->trans->hmp;
2656 hammer_node_lock_t item;
2657
2658 if (parent->copy == NULL) {
2659 parent->copy = kmalloc(sizeof(*parent->copy), hmp->m_misc,
2660 M_WAITOK);
2661 *parent->copy = *parent->node->ondisk;
2662 }
2663 TAILQ_FOREACH(item, &parent->list, entry) {
2664 hammer_btree_lock_copy(cursor, item);
2665 }
2666}
b33e2cc0
MD
2667
2668/*
1775b6a0 2669 * Recursively sync modified copies to the media.
b33e2cc0 2670 */
7ddc70d1 2671int
1775b6a0 2672hammer_btree_sync_copy(hammer_cursor_t cursor, hammer_node_lock_t parent)
b33e2cc0 2673{
1775b6a0 2674 hammer_node_lock_t item;
7ddc70d1 2675 int count = 0;
1775b6a0
MD
2676
2677 if (parent->flags & HAMMER_NODE_LOCK_UPDATED) {
7ddc70d1 2678 ++count;
1775b6a0
MD
2679 hammer_modify_node_all(cursor->trans, parent->node);
2680 *parent->node->ondisk = *parent->copy;
2681 hammer_modify_node_done(parent->node);
2682 if (parent->copy->type == HAMMER_BTREE_TYPE_DELETED) {
2683 hammer_flush_node(parent->node);
2684 hammer_delete_node(cursor->trans, parent->node);
2685 }
2686 }
2687 TAILQ_FOREACH(item, &parent->list, entry) {
7ddc70d1 2688 count += hammer_btree_sync_copy(cursor, item);
1775b6a0 2689 }
7ddc70d1 2690 return(count);
1775b6a0 2691}
b33e2cc0 2692
1775b6a0
MD
2693/*
2694 * Release previously obtained node locks. The caller is responsible for
2695 * cleaning up parent->node itself (its usually just aliased from a cursor),
2696 * but this function will take care of the copies.
2697 */
2698void
2699hammer_btree_unlock_children(hammer_cursor_t cursor, hammer_node_lock_t parent)
2700{
2701 hammer_node_lock_t item;
2702
2703 if (parent->copy) {
2704 kfree(parent->copy, cursor->trans->hmp->m_misc);
2705 parent->copy = NULL; /* safety */
2706 }
2707 while ((item = TAILQ_FIRST(&parent->list)) != NULL) {
2708 TAILQ_REMOVE(&parent->list, item, entry);
2709 hammer_btree_unlock_children(cursor, item);
b33e2cc0
MD
2710 hammer_unlock(&item->node->lock);
2711 hammer_rel_node(item->node);
bac808fe 2712 kfree(item, cursor->trans->hmp->m_misc);
b33e2cc0
MD
2713 }
2714}
2715
8cd0a023
MD
2716/************************************************************************
2717 * MISCELLANIOUS SUPPORT *
2718 ************************************************************************/
2719
2720/*
d26d0ae9 2721 * Compare two B-Tree elements, return -N, 0, or +N (e.g. similar to strcmp).
8cd0a023 2722 *
d113fda1 2723 * Note that for this particular function a return value of -1, 0, or +1
9582c7da 2724 * can denote a match if create_tid is otherwise discounted. A create_tid
d5530d22 2725 * of zero is considered to be 'infinity' in comparisons.
d113fda1 2726 *
8cd0a023 2727 * See also hammer_rec_rb_compare() and hammer_rec_cmp() in hammer_object.c.
8cd0a023
MD
2728 */
2729int
2730hammer_btree_cmp(hammer_base_elm_t key1, hammer_base_elm_t key2)
2731{
2f85fa4d
MD
2732 if (key1->localization < key2->localization)
2733 return(-5);
2734 if (key1->localization > key2->localization)
2735 return(5);
2736
d26d0ae9
MD
2737 if (key1->obj_id < key2->obj_id)
2738 return(-4);
2739 if (key1->obj_id > key2->obj_id)
2740 return(4);
8cd0a023 2741
d26d0ae9
MD
2742 if (key1->rec_type < key2->rec_type)
2743 return(-3);
2744 if (key1->rec_type > key2->rec_type)
2745 return(3);
8cd0a023 2746
8cd0a023
MD
2747 if (key1->key < key2->key)
2748 return(-2);
2749 if (key1->key > key2->key)
2750 return(2);
d113fda1 2751
d5530d22 2752 /*
9582c7da
MD
2753 * A create_tid of zero indicates a record which is undeletable
2754 * and must be considered to have a value of positive infinity.
d5530d22 2755 */
9582c7da
MD
2756 if (key1->create_tid == 0) {
2757 if (key2->create_tid == 0)
d5530d22
MD
2758 return(0);
2759 return(1);
2760 }
9582c7da 2761 if (key2->create_tid == 0)
d5530d22 2762 return(-1);
9582c7da 2763 if (key1->create_tid < key2->create_tid)
d113fda1 2764 return(-1);
9582c7da 2765 if (key1->create_tid > key2->create_tid)
d113fda1 2766 return(1);
8cd0a023
MD
2767 return(0);
2768}
2769
c0ade690 2770/*
d5530d22
MD
2771 * Test a timestamp against an element to determine whether the
2772 * element is visible. A timestamp of 0 means 'infinity'.
c0ade690
MD
2773 */
2774int
d5530d22 2775hammer_btree_chkts(hammer_tid_t asof, hammer_base_elm_t base)
c0ade690 2776{
d5530d22
MD
2777 if (asof == 0) {
2778 if (base->delete_tid)
2779 return(1);
2780 return(0);
2781 }
2782 if (asof < base->create_tid)
d26d0ae9 2783 return(-1);
d5530d22 2784 if (base->delete_tid && asof >= base->delete_tid)
d26d0ae9 2785 return(1);
c0ade690
MD
2786 return(0);
2787}
2788
8cd0a023
MD
2789/*
2790 * Create a separator half way inbetween key1 and key2. For fields just
d5530d22
MD
2791 * one unit apart, the separator will match key2. key1 is on the left-hand
2792 * side and key2 is on the right-hand side.
8cd0a023 2793 *
9391cded 2794 * key2 must be >= the separator. It is ok for the separator to match key2.
36f82b23 2795 *
9391cded
MD
2796 * NOTE: Even if key1 does not match key2, the separator may wind up matching
2797 * key2.
2798 *
2799 * NOTE: It might be beneficial to just scrap this whole mess and just
2800 * set the separator to key2.
8cd0a023
MD
2801 */
2802#define MAKE_SEPARATOR(key1, key2, dest, field) \
2803 dest->field = key1->field + ((key2->field - key1->field + 1) >> 1);
2804
2805static void
2806hammer_make_separator(hammer_base_elm_t key1, hammer_base_elm_t key2,
2807 hammer_base_elm_t dest)
2808{
2809 bzero(dest, sizeof(*dest));
d5530d22 2810
9391cded
MD
2811 dest->rec_type = key2->rec_type;
2812 dest->key = key2->key;
2f85fa4d 2813 dest->obj_id = key2->obj_id;
9391cded
MD
2814 dest->create_tid = key2->create_tid;
2815
2f85fa4d
MD
2816 MAKE_SEPARATOR(key1, key2, dest, localization);
2817 if (key1->localization == key2->localization) {
2818 MAKE_SEPARATOR(key1, key2, dest, obj_id);
2819 if (key1->obj_id == key2->obj_id) {
2820 MAKE_SEPARATOR(key1, key2, dest, rec_type);
2821 if (key1->rec_type == key2->rec_type) {
2822 MAKE_SEPARATOR(key1, key2, dest, key);
2823 /*
2824 * Don't bother creating a separator for
2825 * create_tid, which also conveniently avoids
2826 * having to handle the create_tid == 0
2827 * (infinity) case. Just leave create_tid
2828 * set to key2.
2829 *
2830 * Worst case, dest matches key2 exactly,
2831 * which is acceptable.
2832 */
2833 }
d5530d22 2834 }
d113fda1 2835 }
8cd0a023
MD
2836}
2837
2838#undef MAKE_SEPARATOR
2839
2840/*
2841 * Return whether a generic internal or leaf node is full
2842 */
2843static int
2844btree_node_is_full(hammer_node_ondisk_t node)
2845{
2846 switch(node->type) {
2847 case HAMMER_BTREE_TYPE_INTERNAL:
2848 if (node->count == HAMMER_BTREE_INT_ELMS)
2849 return(1);
2850 break;
2851 case HAMMER_BTREE_TYPE_LEAF:
2852 if (node->count == HAMMER_BTREE_LEAF_ELMS)
2853 return(1);
2854 break;
2855 default:
2856 panic("illegal btree subtype");
2857 }
2858 return(0);
2859}
9944ae54 2860
8cd0a023
MD
2861#if 0
2862static int
2863btree_max_elements(u_int8_t type)
2864{
2865 if (type == HAMMER_BTREE_TYPE_LEAF)
2866 return(HAMMER_BTREE_LEAF_ELMS);
2867 if (type == HAMMER_BTREE_TYPE_INTERNAL)
2868 return(HAMMER_BTREE_INT_ELMS);
2869 panic("btree_max_elements: bad type %d\n", type);
2870}
2871#endif
2872
c0ade690
MD
2873void
2874hammer_print_btree_node(hammer_node_ondisk_t ondisk)
2875{
2876 hammer_btree_elm_t elm;
2877 int i;
2878
47197d71 2879 kprintf("node %p count=%d parent=%016llx type=%c\n",
973c11b9
MD
2880 ondisk, ondisk->count,
2881 (long long)ondisk->parent, ondisk->type);
c0ade690
MD
2882
2883 /*
2884 * Dump both boundary elements if an internal node
2885 */
2886 if (ondisk->type == HAMMER_BTREE_TYPE_INTERNAL) {
2887 for (i = 0; i <= ondisk->count; ++i) {
2888 elm = &ondisk->elms[i];
2889 hammer_print_btree_elm(elm, ondisk->type, i);
2890 }
2891 } else {
2892 for (i = 0; i < ondisk->count; ++i) {
2893 elm = &ondisk->elms[i];
2894 hammer_print_btree_elm(elm, ondisk->type, i);
2895 }
2896 }
2897}
2898
2899void
2900hammer_print_btree_elm(hammer_btree_elm_t elm, u_int8_t type, int i)
2901{
2902 kprintf(" %2d", i);
973c11b9
MD
2903 kprintf("\tobj_id = %016llx\n", (long long)elm->base.obj_id);
2904 kprintf("\tkey = %016llx\n", (long long)elm->base.key);
2905 kprintf("\tcreate_tid = %016llx\n", (long long)elm->base.create_tid);
2906 kprintf("\tdelete_tid = %016llx\n", (long long)elm->base.delete_tid);
c0ade690
MD
2907 kprintf("\trec_type = %04x\n", elm->base.rec_type);
2908 kprintf("\tobj_type = %02x\n", elm->base.obj_type);
fe7678ee
MD
2909 kprintf("\tbtype = %02x (%c)\n",
2910 elm->base.btype,
2911 (elm->base.btype ? elm->base.btype : '?'));
2f85fa4d 2912 kprintf("\tlocalization = %02x\n", elm->base.localization);
fe7678ee
MD
2913
2914 switch(type) {
2915 case HAMMER_BTREE_TYPE_INTERNAL:
47197d71 2916 kprintf("\tsubtree_off = %016llx\n",
973c11b9 2917 (long long)elm->internal.subtree_offset);
fe7678ee 2918 break;
fe7678ee 2919 case HAMMER_BTREE_TYPE_RECORD:
973c11b9
MD
2920 kprintf("\tdata_offset = %016llx\n",
2921 (long long)elm->leaf.data_offset);
c0ade690
MD
2922 kprintf("\tdata_len = %08x\n", elm->leaf.data_len);
2923 kprintf("\tdata_crc = %08x\n", elm->leaf.data_crc);
fe7678ee 2924 break;
c0ade690
MD
2925 }
2926}