AMD64 - Fix many compile-time warnings. int/ptr type mismatches, %llx, etc.
[dragonfly.git] / sys / vfs / hammer / hammer_cursor.c
CommitLineData
8cd0a023 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_cursor.c,v 1.42 2008/08/06 15:38:58 dillon Exp $
8cd0a023
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35 */
36
37/*
38 * HAMMER B-Tree index - cursor support routines
39 */
40#include "hammer.h"
41
f36a9737 42static int hammer_load_cursor_parent(hammer_cursor_t cursor, int try_exclusive);
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43
44/*
61aeeb33 45 * Initialize a fresh cursor using the B-Tree node cache. If the cache
47197d71 46 * is not available initialize a fresh cursor at the root of the filesystem.
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47 */
48int
36f82b23 49hammer_init_cursor(hammer_transaction_t trans, hammer_cursor_t cursor,
bcac4bbb 50 hammer_node_cache_t cache, hammer_inode_t ip)
8cd0a023 51{
47197d71 52 hammer_volume_t volume;
61aeeb33 53 hammer_node_t node;
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54 int error;
55
56 bzero(cursor, sizeof(*cursor));
61aeeb33 57
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58 cursor->trans = trans;
59
61aeeb33 60 /*
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61 * If the cursor operation is on behalf of an inode, lock
62 * the inode.
63 */
64 if ((cursor->ip = ip) != NULL) {
65 ++ip->cursor_ip_refs;
66 if (trans->type == HAMMER_TRANS_FLS)
67 hammer_lock_ex(&ip->lock);
68 else
69 hammer_lock_sh(&ip->lock);
70 }
71
72 /*
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73 * Step 1 - acquire a locked node from the cache if possible
74 */
bcac4bbb 75 if (cache && cache->node) {
4c286c36 76 node = hammer_ref_node_safe(trans, cache, &error);
61aeeb33 77 if (error == 0) {
98da6d8c 78 hammer_lock_sh(&node->lock);
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79 if (node->flags & HAMMER_NODE_DELETED) {
80 hammer_unlock(&node->lock);
81 hammer_rel_node(node);
82 node = NULL;
83 }
61aeeb33 84 }
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MD
85 if (node == NULL)
86 ++hammer_stats_btree_root_iterations;
61aeeb33
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87 } else {
88 node = NULL;
39d8fd63 89 ++hammer_stats_btree_root_iterations;
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90 }
91
92 /*
93 * Step 2 - If we couldn't get a node from the cache, get
47197d71 94 * the one from the root of the filesystem.
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95 */
96 while (node == NULL) {
36f82b23 97 volume = hammer_get_root_volume(trans->hmp, &error);
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98 if (error)
99 break;
82010f9f 100 node = hammer_get_node(trans, volume->ondisk->vol0_btree_root,
19619882 101 0, &error);
47197d71 102 hammer_rel_volume(volume, 0);
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103 if (error)
104 break;
98da6d8c 105 hammer_lock_sh(&node->lock);
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106
107 /*
108 * If someone got in before we could lock the node, retry.
109 */
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110 if (node->flags & HAMMER_NODE_DELETED) {
111 hammer_unlock(&node->lock);
112 hammer_rel_node(node);
113 node = NULL;
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114 continue;
115 }
116 if (volume->ondisk->vol0_btree_root != node->node_offset) {
117 hammer_unlock(&node->lock);
118 hammer_rel_node(node);
119 node = NULL;
120 continue;
61aeeb33 121 }
8cd0a023 122 }
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123
124 /*
125 * Step 3 - finish initializing the cursor by acquiring the parent
126 */
127 cursor->node = node;
8cd0a023 128 if (error == 0)
f36a9737 129 error = hammer_load_cursor_parent(cursor, 0);
0b075555 130 KKASSERT(error == 0);
a84a197d 131 /* if (error) hammer_done_cursor(cursor); */
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132 return(error);
133}
134
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135/*
136 * Normalize a cursor. Sometimes cursors can be left in a state
137 * where node is NULL. If the cursor is in this state, cursor up.
138 */
139void
140hammer_normalize_cursor(hammer_cursor_t cursor)
141{
142 if (cursor->node == NULL) {
143 KKASSERT(cursor->parent != NULL);
144 hammer_cursor_up(cursor);
145 }
146}
147
148
8cd0a023 149/*
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150 * We are finished with a cursor. We NULL out various fields as sanity
151 * check, in case the structure is inappropriately used afterwords.
152 */
153void
154hammer_done_cursor(hammer_cursor_t cursor)
155{
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156 hammer_inode_t ip;
157
adf01747 158 KKASSERT((cursor->flags & HAMMER_CURSOR_TRACKED) == 0);
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159 if (cursor->parent) {
160 hammer_unlock(&cursor->parent->lock);
161 hammer_rel_node(cursor->parent);
162 cursor->parent = NULL;
163 }
164 if (cursor->node) {
165 hammer_unlock(&cursor->node->lock);
166 hammer_rel_node(cursor->node);
167 cursor->node = NULL;
168 }
169 if (cursor->data_buffer) {
170 hammer_rel_buffer(cursor->data_buffer, 0);
171 cursor->data_buffer = NULL;
172 }
4e17f465 173 if ((ip = cursor->ip) != NULL) {
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174 KKASSERT(ip->cursor_ip_refs > 0);
175 --ip->cursor_ip_refs;
176 hammer_unlock(&ip->lock);
177 cursor->ip = NULL;
178 }
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179 if (cursor->iprec) {
180 hammer_rel_mem_record(cursor->iprec);
181 cursor->iprec = NULL;
182 }
4e17f465 183
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184 /*
185 * If we deadlocked this node will be referenced. Do a quick
186 * lock/unlock to wait for the deadlock condition to clear.
187 */
188 if (cursor->deadlk_node) {
af209b0f 189 hammer_lock_ex_ident(&cursor->deadlk_node->lock, "hmrdlk");
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190 hammer_unlock(&cursor->deadlk_node->lock);
191 hammer_rel_node(cursor->deadlk_node);
192 cursor->deadlk_node = NULL;
193 }
b84de5af 194 if (cursor->deadlk_rec) {
a99b9ea2 195 hammer_wait_mem_record_ident(cursor->deadlk_rec, "hmmdlr");
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196 hammer_rel_mem_record(cursor->deadlk_rec);
197 cursor->deadlk_rec = NULL;
198 }
6a37e7e4 199
40043e7f 200 cursor->data = NULL;
11ad5ade 201 cursor->leaf = NULL;
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202 cursor->left_bound = NULL;
203 cursor->right_bound = NULL;
36f82b23 204 cursor->trans = NULL;
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205}
206
207/*
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208 * Upgrade cursor->node and cursor->parent to exclusive locks. This
209 * function can return EDEADLK.
210 *
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211 * The lock must already be either held shared or already held exclusively
212 * by us.
213 *
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214 * If we fail to upgrade the lock and cursor->deadlk_node is NULL,
215 * we add another reference to the node that failed and set
216 * cursor->deadlk_node so hammer_done_cursor() can block on it.
217 */
218int
219hammer_cursor_upgrade(hammer_cursor_t cursor)
220{
221 int error;
222
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223 error = hammer_lock_upgrade(&cursor->node->lock);
224 if (error && cursor->deadlk_node == NULL) {
225 cursor->deadlk_node = cursor->node;
226 hammer_ref_node(cursor->deadlk_node);
227 } else if (error == 0 && cursor->parent) {
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228 error = hammer_lock_upgrade(&cursor->parent->lock);
229 if (error && cursor->deadlk_node == NULL) {
230 cursor->deadlk_node = cursor->parent;
231 hammer_ref_node(cursor->deadlk_node);
232 }
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233 }
234 return(error);
235}
236
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237int
238hammer_cursor_upgrade_node(hammer_cursor_t cursor)
239{
240 int error;
241
242 error = hammer_lock_upgrade(&cursor->node->lock);
243 if (error && cursor->deadlk_node == NULL) {
244 cursor->deadlk_node = cursor->node;
245 hammer_ref_node(cursor->deadlk_node);
246 }
247 return(error);
248}
249
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250/*
251 * Downgrade cursor->node and cursor->parent to shared locks. This
252 * function can return EDEADLK.
253 */
254void
255hammer_cursor_downgrade(hammer_cursor_t cursor)
256{
7aa3b8a6 257 if (hammer_lock_excl_owned(&cursor->node->lock, curthread))
6a37e7e4 258 hammer_lock_downgrade(&cursor->node->lock);
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259 if (cursor->parent &&
260 hammer_lock_excl_owned(&cursor->parent->lock, curthread)) {
6a37e7e4 261 hammer_lock_downgrade(&cursor->parent->lock);
7aa3b8a6 262 }
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263}
264
32c90105
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265/*
266 * Seek the cursor to the specified node and index.
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267 *
268 * The caller must ref the node prior to calling this routine and release
269 * it after it returns. If the seek succeeds the cursor will gain its own
270 * ref on the node.
32c90105
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271 */
272int
273hammer_cursor_seek(hammer_cursor_t cursor, hammer_node_t node, int index)
274{
275 int error;
276
277 hammer_cursor_downgrade(cursor);
278 error = 0;
279
280 if (cursor->node != node) {
281 hammer_unlock(&cursor->node->lock);
282 hammer_rel_node(cursor->node);
283 cursor->node = node;
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284 hammer_ref_node(node);
285 hammer_lock_sh(&node->lock);
f36a9737 286 KKASSERT ((node->flags & HAMMER_NODE_DELETED) == 0);
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287
288 if (cursor->parent) {
289 hammer_unlock(&cursor->parent->lock);
290 hammer_rel_node(cursor->parent);
291 cursor->parent = NULL;
292 cursor->parent_index = 0;
293 }
f36a9737 294 error = hammer_load_cursor_parent(cursor, 0);
32c90105 295 }
a84a197d 296 cursor->index = index;
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297 return (error);
298}
6a37e7e4 299
6a37e7e4 300/*
47197d71 301 * Load the parent of cursor->node into cursor->parent.
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302 */
303static
304int
f36a9737 305hammer_load_cursor_parent(hammer_cursor_t cursor, int try_exclusive)
8cd0a023 306{
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307 hammer_mount_t hmp;
308 hammer_node_t parent;
309 hammer_node_t node;
310 hammer_btree_elm_t elm;
8cd0a023 311 int error;
c82af904 312 int parent_index;
8cd0a023 313
36f82b23 314 hmp = cursor->trans->hmp;
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315
316 if (cursor->node->ondisk->parent) {
47197d71 317 node = cursor->node;
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318 parent = hammer_btree_get_parent(cursor->trans, node,
319 &parent_index,
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320 &error, try_exclusive);
321 if (error == 0) {
322 elm = &parent->ondisk->elms[parent_index];
323 cursor->parent = parent;
324 cursor->parent_index = parent_index;
325 cursor->left_bound = &elm[0].internal.base;
326 cursor->right_bound = &elm[1].internal.base;
a84a197d 327 }
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328 } else {
329 cursor->parent = NULL;
330 cursor->parent_index = 0;
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331 cursor->left_bound = &hmp->root_btree_beg;
332 cursor->right_bound = &hmp->root_btree_end;
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333 error = 0;
334 }
335 return(error);
336}
337
8cd0a023
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338/*
339 * Cursor up to our parent node. Return ENOENT if we are at the root of
47197d71 340 * the filesystem.
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341 */
342int
6a37e7e4 343hammer_cursor_up(hammer_cursor_t cursor)
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344{
345 int error;
346
6a37e7e4 347 hammer_cursor_downgrade(cursor);
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348
349 /*
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350 * If the parent is NULL we are at the root of the B-Tree and
351 * return ENOENT.
352 */
353 if (cursor->parent == NULL)
354 return (ENOENT);
355
356 /*
357 * Set the node to its parent.
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358 */
359 hammer_unlock(&cursor->node->lock);
360 hammer_rel_node(cursor->node);
361 cursor->node = cursor->parent;
362 cursor->index = cursor->parent_index;
363 cursor->parent = NULL;
364 cursor->parent_index = 0;
365
f36a9737 366 error = hammer_load_cursor_parent(cursor, 0);
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367 return(error);
368}
369
370/*
f36a9737 371 * Special cursor up given a locked cursor. The orignal node is not
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372 * unlocked or released and the cursor is not downgraded.
373 *
374 * This function will recover from deadlocks. EDEADLK cannot be returned.
f36a9737
MD
375 */
376int
377hammer_cursor_up_locked(hammer_cursor_t cursor)
378{
379 hammer_node_t save;
380 int error;
381
382 /*
383 * If the parent is NULL we are at the root of the B-Tree and
384 * return ENOENT.
385 */
386 if (cursor->parent == NULL)
387 return (ENOENT);
388
389 save = cursor->node;
390
391 /*
392 * Set the node to its parent.
393 */
394 cursor->node = cursor->parent;
395 cursor->index = cursor->parent_index;
396 cursor->parent = NULL;
397 cursor->parent_index = 0;
398
399 /*
400 * load the new parent, attempt to exclusively lock it. Note that
401 * we are still holding the old parent (now cursor->node) exclusively
402 * locked. This can return EDEADLK.
403 */
404 error = hammer_load_cursor_parent(cursor, 1);
405 if (error) {
406 cursor->parent = cursor->node;
407 cursor->parent_index = cursor->index;
408 cursor->node = save;
409 cursor->index = 0;
410 }
411 return(error);
412}
413
414
415/*
8cd0a023
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416 * Cursor down through the current node, which must be an internal node.
417 *
418 * This routine adjusts the cursor and sets index to 0.
419 */
420int
421hammer_cursor_down(hammer_cursor_t cursor)
422{
423 hammer_node_t node;
424 hammer_btree_elm_t elm;
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425 int error;
426
427 /*
428 * The current node becomes the current parent
429 */
6a37e7e4 430 hammer_cursor_downgrade(cursor);
8cd0a023 431 node = cursor->node;
8cd0a023
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432 KKASSERT(cursor->index >= 0 && cursor->index < node->ondisk->count);
433 if (cursor->parent) {
434 hammer_unlock(&cursor->parent->lock);
435 hammer_rel_node(cursor->parent);
436 }
437 cursor->parent = node;
438 cursor->parent_index = cursor->index;
439 cursor->node = NULL;
440 cursor->index = 0;
441
442 /*
76376933 443 * Extract element to push into at (node,index), set bounds.
8cd0a023
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444 */
445 elm = &node->ondisk->elms[cursor->parent_index];
446
447 /*
fe7678ee
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448 * Ok, push down into elm. If elm specifies an internal or leaf
449 * node the current node must be an internal node. If elm specifies
450 * a spike then the current node must be a leaf node.
8cd0a023 451 */
fe7678ee
MD
452 switch(elm->base.btype) {
453 case HAMMER_BTREE_TYPE_INTERNAL:
454 case HAMMER_BTREE_TYPE_LEAF:
455 KKASSERT(node->ondisk->type == HAMMER_BTREE_TYPE_INTERNAL);
456 KKASSERT(elm->internal.subtree_offset != 0);
457 cursor->left_bound = &elm[0].internal.base;
458 cursor->right_bound = &elm[1].internal.base;
82010f9f 459 node = hammer_get_node(cursor->trans,
19619882 460 elm->internal.subtree_offset, 0, &error);
fe7678ee 461 if (error == 0) {
40043e7f 462 KASSERT(elm->base.btype == node->ondisk->type, ("BTYPE MISMATCH %c %c NODE %p\n", elm->base.btype, node->ondisk->type, node));
b33e2cc0 463 if (node->ondisk->parent != cursor->parent->node_offset)
973c11b9 464 panic("node %p %016llx vs %016llx\n", node, (long long)node->ondisk->parent, (long long)cursor->parent->node_offset);
fe7678ee
MD
465 KKASSERT(node->ondisk->parent == cursor->parent->node_offset);
466 }
467 break;
fe7678ee
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468 default:
469 panic("hammer_cursor_down: illegal btype %02x (%c)\n",
470 elm->base.btype,
471 (elm->base.btype ? elm->base.btype : '?'));
472 break;
8cd0a023
MD
473 }
474 if (error == 0) {
6a37e7e4 475 hammer_lock_sh(&node->lock);
f36a9737 476 KKASSERT ((node->flags & HAMMER_NODE_DELETED) == 0);
8cd0a023
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477 cursor->node = node;
478 cursor->index = 0;
479 }
480 return(error);
481}
482
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483/************************************************************************
484 * DEADLOCK RECOVERY *
485 ************************************************************************
486 *
487 * These are the new deadlock recovery functions. Currently they are only
488 * used for the mirror propagation and physical node removal cases but
489 * ultimately the intention is to use them for all deadlock recovery
490 * operations.
491 */
adf01747 492void
982be4bf 493hammer_unlock_cursor(hammer_cursor_t cursor)
b3bad96f 494{
b3bad96f 495 hammer_node_t node;
b3bad96f 496
adf01747 497 KKASSERT((cursor->flags & HAMMER_CURSOR_TRACKED) == 0);
b3bad96f 498 KKASSERT(cursor->node);
19168d41
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499
500 /*
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501 * Release the cursor's locks and track B-Tree operations on node.
502 * While being tracked our cursor can be modified by other threads
5c8d05e2 503 * and the node may be replaced.
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504 */
505 if (cursor->parent) {
506 hammer_unlock(&cursor->parent->lock);
507 hammer_rel_node(cursor->parent);
508 cursor->parent = NULL;
509 }
510 node = cursor->node;
adf01747 511 cursor->flags |= HAMMER_CURSOR_TRACKED;
b3bad96f 512 TAILQ_INSERT_TAIL(&node->cursor_list, cursor, deadlk_entry);
b3bad96f 513 hammer_unlock(&node->lock);
adf01747
MD
514}
515
516/*
517 * Get the cursor heated up again. The cursor's node may have
518 * changed and we might have to locate the new parent.
519 *
520 * If the exact element we were on got deleted RIPOUT will be
521 * set and we must clear ATEDISK so an iteration does not skip
522 * the element after it.
523 */
524int
982be4bf 525hammer_lock_cursor(hammer_cursor_t cursor)
adf01747 526{
adf01747
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527 hammer_node_t node;
528 int error;
529
530 KKASSERT(cursor->flags & HAMMER_CURSOR_TRACKED);
531
532 /*
adf01747
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533 * Relock the node
534 */
535 for (;;) {
536 node = cursor->node;
537 hammer_ref_node(node);
538 hammer_lock_sh(&node->lock);
539 if (cursor->node == node) {
540 hammer_rel_node(node);
541 break;
542 }
543 hammer_unlock(&node->lock);
544 hammer_rel_node(node);
545 }
546
547 /*
548 * Untrack the cursor, clean up, and re-establish the parent node.
549 */
550 TAILQ_REMOVE(&node->cursor_list, cursor, deadlk_entry);
551 cursor->flags &= ~HAMMER_CURSOR_TRACKED;
552
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553 /*
554 * If a ripout has occured iterations must re-test the (new)
555 * current element. Clearing ATEDISK prevents the element from
556 * being skipped and RETEST causes it to be re-tested.
557 */
adf01747
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558 if (cursor->flags & HAMMER_CURSOR_TRACKED_RIPOUT) {
559 cursor->flags &= ~HAMMER_CURSOR_TRACKED_RIPOUT;
560 cursor->flags &= ~HAMMER_CURSOR_ATEDISK;
5c8d05e2 561 cursor->flags |= HAMMER_CURSOR_RETEST;
adf01747
MD
562 }
563 error = hammer_load_cursor_parent(cursor, 0);
564 return(error);
565}
566
567/*
568 * Recover from a deadlocked cursor, tracking any node removals or
569 * replacements. If the cursor's current node is removed by another
570 * thread (via btree_remove()) the cursor will be seeked upwards.
98da6d8c
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571 *
572 * The caller is working a modifying operation and must be holding the
573 * sync lock (shared). We do not release the sync lock because this
574 * would break atomicy.
adf01747
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575 */
576int
577hammer_recover_cursor(hammer_cursor_t cursor)
578{
579 int error;
580
982be4bf 581 hammer_unlock_cursor(cursor);
98da6d8c 582 KKASSERT(cursor->trans->sync_lock_refs > 0);
b3bad96f
MD
583
584 /*
585 * Wait for the deadlock to clear
586 */
587 if (cursor->deadlk_node) {
588 hammer_lock_ex_ident(&cursor->deadlk_node->lock, "hmrdlk");
589 hammer_unlock(&cursor->deadlk_node->lock);
590 hammer_rel_node(cursor->deadlk_node);
591 cursor->deadlk_node = NULL;
592 }
593 if (cursor->deadlk_rec) {
594 hammer_wait_mem_record_ident(cursor->deadlk_rec, "hmmdlr");
595 hammer_rel_mem_record(cursor->deadlk_rec);
596 cursor->deadlk_rec = NULL;
597 }
982be4bf 598 error = hammer_lock_cursor(cursor);
adf01747
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599 return(error);
600}
601
602/*
603 * Dup ocursor to ncursor. ncursor inherits ocursor's locks and ocursor
604 * is effectively unlocked and becomes tracked. If ocursor was not locked
605 * then ncursor also inherits the tracking.
606 *
607 * After the caller finishes working with ncursor it must be cleaned up
608 * with hammer_done_cursor(), and the caller must re-lock ocursor.
609 */
3f43fb33
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610hammer_cursor_t
611hammer_push_cursor(hammer_cursor_t ocursor)
adf01747 612{
3f43fb33 613 hammer_cursor_t ncursor;
adf01747
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614 hammer_inode_t ip;
615 hammer_node_t node;
bac808fe 616 hammer_mount_t hmp;
adf01747 617
bac808fe
MD
618 hmp = ocursor->trans->hmp;
619 ncursor = kmalloc(sizeof(*ncursor), hmp->m_misc, M_WAITOK | M_ZERO);
adf01747
MD
620 bcopy(ocursor, ncursor, sizeof(*ocursor));
621
622 node = ocursor->node;
623 hammer_ref_node(node);
624 if ((ocursor->flags & HAMMER_CURSOR_TRACKED) == 0) {
625 ocursor->flags |= HAMMER_CURSOR_TRACKED;
626 TAILQ_INSERT_TAIL(&node->cursor_list, ocursor, deadlk_entry);
b3bad96f 627 }
adf01747
MD
628 if (ncursor->parent)
629 ocursor->parent = NULL;
630 ocursor->data_buffer = NULL;
631 ocursor->leaf = NULL;
632 ocursor->data = NULL;
633 if (ncursor->flags & HAMMER_CURSOR_TRACKED)
634 TAILQ_INSERT_TAIL(&node->cursor_list, ncursor, deadlk_entry);
635 if ((ip = ncursor->ip) != NULL) {
636 ++ip->cursor_ip_refs;
b3bad96f 637 }
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MD
638 if (ncursor->iprec)
639 hammer_ref(&ncursor->iprec->lock);
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MD
640 return(ncursor);
641}
642
643/*
644 * Destroy ncursor and restore ocursor
645 *
646 * This is a temporary hack for the release. We can't afford to lose
647 * the IP lock until the IP object scan code is able to deal with it,
648 * so have ocursor inherit it back.
649 */
650void
651hammer_pop_cursor(hammer_cursor_t ocursor, hammer_cursor_t ncursor)
652{
bac808fe 653 hammer_mount_t hmp;
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MD
654 hammer_inode_t ip;
655
bac808fe 656 hmp = ncursor->trans->hmp;
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MD
657 ip = ncursor->ip;
658 ncursor->ip = NULL;
659 if (ip)
660 --ip->cursor_ip_refs;
661 hammer_done_cursor(ncursor);
bac808fe 662 kfree(ncursor, hmp->m_misc);
3f43fb33 663 KKASSERT(ocursor->ip == ip);
982be4bf 664 hammer_lock_cursor(ocursor);
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665}
666
667/*
668 * onode is being replaced by nnode by the reblocking code.
669 */
670void
671hammer_cursor_replaced_node(hammer_node_t onode, hammer_node_t nnode)
672{
673 hammer_cursor_t cursor;
674
675 while ((cursor = TAILQ_FIRST(&onode->cursor_list)) != NULL) {
676 TAILQ_REMOVE(&onode->cursor_list, cursor, deadlk_entry);
677 TAILQ_INSERT_TAIL(&nnode->cursor_list, cursor, deadlk_entry);
678 KKASSERT(cursor->node == onode);
679 cursor->node = nnode;
680 hammer_ref_node(nnode);
681 hammer_rel_node(onode);
682 }
683}
684
685/*
686 * node is being removed, cursors in deadlock recovery are seeked upward
687 * to the parent.
688 */
689void
690hammer_cursor_removed_node(hammer_node_t node, hammer_node_t parent, int index)
691{
692 hammer_cursor_t cursor;
693
694 KKASSERT(parent != NULL);
695 while ((cursor = TAILQ_FIRST(&node->cursor_list)) != NULL) {
696 KKASSERT(cursor->node == node);
697 KKASSERT(cursor->index == 0);
698 TAILQ_REMOVE(&node->cursor_list, cursor, deadlk_entry);
699 TAILQ_INSERT_TAIL(&parent->cursor_list, cursor, deadlk_entry);
adf01747 700 cursor->flags |= HAMMER_CURSOR_TRACKED_RIPOUT;
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701 cursor->node = parent;
702 cursor->index = index;
703 hammer_ref_node(parent);
704 hammer_rel_node(node);
705 }
706}
707
708/*
709 * node was split at (onode, index) with elements >= index moved to nnode.
710 */
711void
712hammer_cursor_split_node(hammer_node_t onode, hammer_node_t nnode, int index)
713{
714 hammer_cursor_t cursor;
715
716again:
717 TAILQ_FOREACH(cursor, &onode->cursor_list, deadlk_entry) {
718 KKASSERT(cursor->node == onode);
719 if (cursor->index < index)
720 continue;
721 TAILQ_REMOVE(&onode->cursor_list, cursor, deadlk_entry);
722 TAILQ_INSERT_TAIL(&nnode->cursor_list, cursor, deadlk_entry);
723 cursor->node = nnode;
724 cursor->index -= index;
725 hammer_ref_node(nnode);
726 hammer_rel_node(onode);
727 goto again;
728 }
729}
730
731/*
1775b6a0
MD
732 * An element was moved from one node to another or within a node. The
733 * index may also represent the end of the node (index == numelements).
734 *
735 * This is used by the rebalancing code. This is not an insertion or
736 * deletion and any additional elements, including the degenerate case at
737 * the end of the node, will be dealt with by additional distinct calls.
738 */
739void
740hammer_cursor_moved_element(hammer_node_t onode, hammer_node_t nnode,
741 int oindex, int nindex)
742{
743 hammer_cursor_t cursor;
744
745again:
746 TAILQ_FOREACH(cursor, &onode->cursor_list, deadlk_entry) {
747 KKASSERT(cursor->node == onode);
748 if (cursor->index != oindex)
749 continue;
750 TAILQ_REMOVE(&onode->cursor_list, cursor, deadlk_entry);
751 TAILQ_INSERT_TAIL(&nnode->cursor_list, cursor, deadlk_entry);
752 cursor->node = nnode;
753 cursor->index = nindex;
754 hammer_ref_node(nnode);
755 hammer_rel_node(onode);
756 goto again;
757 }
758}
759
760/*
761 * The B-Tree element pointing to the specified node was moved from (oparent)
762 * to (nparent, nindex). We must locate any tracked cursors pointing at
763 * node and adjust their parent accordingly.
764 *
765 * This is used by the rebalancing code when packing elements causes an
766 * element to shift from one node to another.
767 */
768void
769hammer_cursor_parent_changed(hammer_node_t node, hammer_node_t oparent,
770 hammer_node_t nparent, int nindex)
771{
772 hammer_cursor_t cursor;
773
774again:
775 TAILQ_FOREACH(cursor, &node->cursor_list, deadlk_entry) {
776 KKASSERT(cursor->node == node);
777 if (cursor->parent == oparent) {
778 cursor->parent = nparent;
779 cursor->parent_index = nindex;
780 hammer_ref_node(nparent);
781 hammer_rel_node(oparent);
782 goto again;
783 }
784 }
785}
786
787/*
e4a5ff06 788 * Deleted element at (node, index)
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MD
789 *
790 * Shift indexes >= index
791 */
792void
793hammer_cursor_deleted_element(hammer_node_t node, int index)
794{
795 hammer_cursor_t cursor;
796
797 TAILQ_FOREACH(cursor, &node->cursor_list, deadlk_entry) {
798 KKASSERT(cursor->node == node);
799 if (cursor->index == index) {
adf01747 800 cursor->flags |= HAMMER_CURSOR_TRACKED_RIPOUT;
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MD
801 } else if (cursor->index > index) {
802 --cursor->index;
803 }
804 }
805}
806
807/*
e4a5ff06 808 * Inserted element at (node, index)
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MD
809 *
810 * Shift indexes >= index
811 */
812void
813hammer_cursor_inserted_element(hammer_node_t node, int index)
814{
815 hammer_cursor_t cursor;
816
817 TAILQ_FOREACH(cursor, &node->cursor_list, deadlk_entry) {
818 KKASSERT(cursor->node == node);
819 if (cursor->index >= index)
820 ++cursor->index;
821 }
822}
823