2 * Copyright (c) 2008-2012 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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.
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
35 * HAMMER reblocker - This code frees up fragmented physical space
37 * HAMMER only keeps track of free space on a big-block basis. A big-block
38 * containing holes can only be freed by migrating the remaining data in
39 * that big-block into a new big-block, then freeing the big-block.
41 * This function is called from an ioctl or via the hammer support thread.
46 static int hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
47 hammer_cursor_t cursor,
48 hammer_btree_elm_t elm);
49 static int hammer_reblock_data(struct hammer_ioc_reblock *reblock,
50 hammer_cursor_t cursor, hammer_btree_elm_t elm);
51 static int hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
52 hammer_cursor_t cursor, hammer_btree_elm_t elm);
53 static int hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
54 hammer_cursor_t cursor, hammer_btree_elm_t elm);
57 hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip,
58 struct hammer_ioc_reblock *reblock)
60 struct hammer_cursor cursor;
61 hammer_btree_elm_t elm;
66 u_int32_t key_end_localization;
68 if ((reblock->key_beg.localization | reblock->key_end.localization) &
69 HAMMER_LOCALIZE_PSEUDOFS_MASK) {
72 if (reblock->key_beg.obj_id >= reblock->key_end.obj_id)
74 if (reblock->free_level < 0 ||
75 reblock->free_level > HAMMER_BIGBLOCK_SIZE)
79 * A fill_percentage <= 20% is considered an emergency. free_level is
80 * inverted from fill_percentage.
82 if (reblock->free_level >= HAMMER_BIGBLOCK_SIZE * 8 / 10)
83 slop = HAMMER_CHKSPC_EMERGENCY;
85 slop = HAMMER_CHKSPC_REBLOCK;
88 * Ioctl caller has only set localization type to reblock.
89 * Initialize cursor key localization with ip localization.
91 reblock->key_cur = reblock->key_beg;
92 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
93 reblock->key_cur.localization += ip->obj_localization;
95 key_end_localization = reblock->key_end.localization;
96 key_end_localization &= HAMMER_LOCALIZE_MASK;
97 key_end_localization += ip->obj_localization;
100 seq = trans->hmp->flusher.done;
102 error = hammer_init_cursor(trans, &cursor, NULL, NULL);
104 hammer_done_cursor(&cursor);
107 cursor.key_beg.localization = reblock->key_cur.localization;
108 cursor.key_beg.obj_id = reblock->key_cur.obj_id;
109 cursor.key_beg.key = HAMMER_MIN_KEY;
110 cursor.key_beg.create_tid = 1;
111 cursor.key_beg.delete_tid = 0;
112 cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
113 cursor.key_beg.obj_type = 0;
115 cursor.key_end.localization = key_end_localization;
116 cursor.key_end.obj_id = reblock->key_end.obj_id;
117 cursor.key_end.key = HAMMER_MAX_KEY;
118 cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
119 cursor.key_end.delete_tid = 0;
120 cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
121 cursor.key_end.obj_type = 0;
123 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
124 cursor.flags |= HAMMER_CURSOR_BACKEND;
125 cursor.flags |= HAMMER_CURSOR_NOSWAPCACHE;
128 * This flag allows the btree scan code to return internal nodes,
129 * so we can reblock them in addition to the leafs. Only specify it
130 * if we intend to reblock B-Tree nodes.
132 if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
133 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
135 error = hammer_btree_first(&cursor);
138 * Internal or Leaf node
140 KKASSERT(cursor.index < cursor.node->ondisk->count);
141 elm = &cursor.node->ondisk->elms[cursor.index];
142 reblock->key_cur.obj_id = elm->base.obj_id;
143 reblock->key_cur.localization = elm->base.localization;
146 * Yield to more important tasks
148 if ((error = hammer_signal_check(trans->hmp)) != 0)
152 * If there is insufficient free space it may be due to
153 * reserved bigblocks, which flushing might fix.
155 * We must force a retest in case the unlocked cursor is
156 * moved to the end of the leaf, or moved to an internal
159 * WARNING: See warnings in hammer_unlock_cursor() function.
161 if (hammer_checkspace(trans->hmp, slop)) {
162 if (++checkspace_count == 10) {
166 hammer_unlock_cursor(&cursor);
167 cursor.flags |= HAMMER_CURSOR_RETEST;
168 hammer_flusher_wait(trans->hmp, seq);
169 hammer_lock_cursor(&cursor);
170 seq = hammer_flusher_async(trans->hmp, NULL);
175 * Acquiring the sync_lock prevents the operation from
176 * crossing a synchronization boundary.
178 * NOTE: cursor.node may have changed on return.
180 * WARNING: See warnings in hammer_unlock_cursor() function.
182 hammer_sync_lock_sh(trans);
183 error = hammer_reblock_helper(reblock, &cursor, elm);
184 hammer_sync_unlock(trans);
186 while (hammer_flusher_meta_halflimit(trans->hmp) ||
187 hammer_flusher_undo_exhausted(trans, 2)) {
188 hammer_unlock_cursor(&cursor);
189 hammer_flusher_wait(trans->hmp, seq);
190 hammer_lock_cursor(&cursor);
191 seq = hammer_flusher_async_one(trans->hmp);
195 * Setup for iteration, our cursor flags may be modified by
196 * other threads while we are unlocked.
198 cursor.flags |= HAMMER_CURSOR_ATEDISK;
201 * We allocate data buffers, which atm we don't track
202 * dirty levels for because we allow the kernel to write
203 * them. But if we allocate too many we can still deadlock
206 * WARNING: See warnings in hammer_unlock_cursor() function.
207 * (The cursor's node and element may change!)
210 hammer_unlock_cursor(&cursor);
211 bwillwrite(HAMMER_XBUFSIZE);
212 hammer_lock_cursor(&cursor);
217 error = hammer_btree_iterate(&cursor);
222 hammer_done_cursor(&cursor);
223 if (error == EWOULDBLOCK) {
224 hammer_flusher_sync(trans->hmp);
227 if (error == EDEADLK)
229 if (error == EINTR) {
230 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
234 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
239 * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
241 * XXX We have no visibility into internal B-Tree nodes at the moment,
245 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
246 hammer_cursor_t cursor, hammer_btree_elm_t elm)
249 hammer_off_t tmp_offset;
250 hammer_node_ondisk_t ondisk;
251 struct hammer_btree_leaf_elm leaf;
258 hmp = cursor->trans->hmp;
261 * Reblock data. Note that data embedded in a record is reblocked
262 * by the record reblock code. Data processing only occurs at leaf
263 * nodes and for RECORD element types.
265 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
267 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
269 tmp_offset = elm->leaf.data_offset;
276 * NOTE: Localization restrictions may also have been set-up, we can't
277 * just set the match flags willy-nilly here.
279 switch(elm->leaf.base.rec_type) {
280 case HAMMER_RECTYPE_INODE:
281 case HAMMER_RECTYPE_SNAPSHOT:
282 case HAMMER_RECTYPE_CONFIG:
283 iocflags = HAMMER_IOC_DO_INODES;
285 case HAMMER_RECTYPE_EXT:
286 case HAMMER_RECTYPE_FIX:
287 case HAMMER_RECTYPE_PFS:
288 case HAMMER_RECTYPE_DIRENTRY:
289 iocflags = HAMMER_IOC_DO_DIRS;
291 case HAMMER_RECTYPE_DATA:
292 case HAMMER_RECTYPE_DB:
293 iocflags = HAMMER_IOC_DO_DATA;
299 if (reblock->head.flags & iocflags) {
300 ++reblock->data_count;
301 reblock->data_byte_count += elm->leaf.data_len;
302 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
303 if (hammer_debug_general & 0x4000)
304 kprintf("D %6d/%d\n", bytes, reblock->free_level);
305 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
306 bytes >= reblock->free_level) {
308 * This is nasty, the uncache code may have to get
309 * vnode locks and because of that we can't hold
312 * WARNING: See warnings in hammer_unlock_cursor()
316 hammer_unlock_cursor(cursor);
317 hammer_io_direct_uncache(hmp, &leaf);
318 hammer_lock_cursor(cursor);
321 * elm may have become stale or invalid, reload it.
322 * ondisk variable is temporary only. Note that
323 * cursor->node and thus cursor->node->ondisk may
326 ondisk = cursor->node->ondisk;
327 elm = &ondisk->elms[cursor->index];
328 if (cursor->flags & HAMMER_CURSOR_RETEST) {
329 kprintf("hammer: debug: retest on "
330 "reblocker uncache\n");
332 } else if (ondisk->type != HAMMER_BTREE_TYPE_LEAF ||
333 cursor->index >= ondisk->count) {
334 kprintf("hammer: debug: shifted on "
335 "reblocker uncache\n");
337 } else if (bcmp(&elm->leaf, &leaf, sizeof(leaf))) {
338 kprintf("hammer: debug: changed on "
339 "reblocker uncache\n");
343 error = hammer_cursor_upgrade(cursor);
345 KKASSERT(cursor->index < ondisk->count);
346 error = hammer_reblock_data(reblock,
350 ++reblock->data_moves;
351 reblock->data_byte_moves += elm->leaf.data_len;
358 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked
359 * on initial entry only (element 0). An internal node is reblocked
360 * when entered upward from its first leaf node only (also element 0).
361 * Further revisits of the internal node (index > 0) are ignored.
363 tmp_offset = cursor->node->node_offset;
364 if (cursor->index == 0 &&
365 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
366 ++reblock->btree_count;
367 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
368 if (hammer_debug_general & 0x4000)
369 kprintf("B %6d/%d\n", bytes, reblock->free_level);
370 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
371 bytes >= reblock->free_level) {
372 error = hammer_cursor_upgrade(cursor);
374 if (cursor->parent) {
375 KKASSERT(cursor->parent_index <
376 cursor->parent->ondisk->count);
377 elm = &cursor->parent->ondisk->elms[cursor->parent_index];
381 switch(cursor->node->ondisk->type) {
382 case HAMMER_BTREE_TYPE_LEAF:
383 error = hammer_reblock_leaf_node(
384 reblock, cursor, elm);
386 case HAMMER_BTREE_TYPE_INTERNAL:
387 error = hammer_reblock_int_node(
388 reblock, cursor, elm);
391 panic("Illegal B-Tree node type");
395 ++reblock->btree_moves;
400 hammer_cursor_downgrade(cursor);
405 * Reblock a record's data. Both the B-Tree element and record pointers
406 * to the data must be adjusted.
409 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
410 hammer_cursor_t cursor, hammer_btree_elm_t elm)
412 struct hammer_buffer *data_buffer = NULL;
413 hammer_off_t ndata_offset;
417 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
418 HAMMER_CURSOR_GET_LEAF);
421 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
422 elm->leaf.base.rec_type,
423 &ndata_offset, &data_buffer,
427 hammer_io_notmeta(data_buffer);
430 * Move the data. Note that we must invalidate any cached
431 * data buffer in the cursor before calling blockmap_free.
432 * The blockmap_free may free up the entire big-block and
433 * will not be able to invalidate it if the cursor is holding
434 * a data buffer cached in that big block.
436 hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
437 bcopy(cursor->data, ndata, elm->leaf.data_len);
438 hammer_modify_buffer_done(data_buffer);
439 hammer_cursor_invalidate_cache(cursor);
441 hammer_blockmap_free(cursor->trans,
442 elm->leaf.data_offset, elm->leaf.data_len);
444 hammer_modify_node(cursor->trans, cursor->node,
445 &elm->leaf.data_offset, sizeof(hammer_off_t));
446 elm->leaf.data_offset = ndata_offset;
447 hammer_modify_node_done(cursor->node);
451 hammer_rel_buffer(data_buffer, 0);
456 * Reblock a B-Tree leaf node. The parent must be adjusted to point to
457 * the new copy of the leaf node.
459 * elm is a pointer to the parent element pointing at cursor.node.
462 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
463 hammer_cursor_t cursor, hammer_btree_elm_t elm)
470 * Don't supply a hint when allocating the leaf. Fills are done
471 * from the leaf upwards.
473 onode = cursor->node;
474 nnode = hammer_alloc_btree(cursor->trans, 0, &error);
482 hammer_lock_ex(&nnode->lock);
483 hammer_modify_node_noundo(cursor->trans, nnode);
484 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
488 * We are not the root of the B-Tree
490 hammer_modify_node(cursor->trans, cursor->parent,
491 &elm->internal.subtree_offset,
492 sizeof(elm->internal.subtree_offset));
493 elm->internal.subtree_offset = nnode->node_offset;
494 hammer_modify_node_done(cursor->parent);
497 * We are the root of the B-Tree
499 hammer_volume_t volume;
501 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
502 KKASSERT(error == 0);
504 hammer_modify_volume_field(cursor->trans, volume,
506 volume->ondisk->vol0_btree_root = nnode->node_offset;
507 hammer_modify_volume_done(volume);
508 hammer_rel_volume(volume, 0);
511 hammer_cursor_replaced_node(onode, nnode);
512 hammer_delete_node(cursor->trans, onode);
514 if (hammer_debug_general & 0x4000) {
515 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
516 (long long)onode->node_offset,
517 (long long)nnode->node_offset);
519 hammer_modify_node_done(nnode);
520 cursor->node = nnode;
522 hammer_unlock(&onode->lock);
523 hammer_rel_node(onode);
529 * Reblock a B-Tree internal node. The parent must be adjusted to point to
530 * the new copy of the internal node, and the node's children's parent
531 * pointers must also be adjusted to point to the new copy.
533 * elm is a pointer to the parent element pointing at cursor.node.
536 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
537 hammer_cursor_t cursor, hammer_btree_elm_t elm)
539 struct hammer_node_lock lockroot;
545 hammer_node_lock_init(&lockroot, cursor->node);
546 error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL);
550 onode = cursor->node;
551 nnode = hammer_alloc_btree(cursor->trans, 0, &error);
557 * Move the node. Adjust the parent's pointer to us first.
559 hammer_lock_ex(&nnode->lock);
560 hammer_modify_node_noundo(cursor->trans, nnode);
561 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
565 * We are not the root of the B-Tree
567 hammer_modify_node(cursor->trans, cursor->parent,
568 &elm->internal.subtree_offset,
569 sizeof(elm->internal.subtree_offset));
570 elm->internal.subtree_offset = nnode->node_offset;
571 hammer_modify_node_done(cursor->parent);
574 * We are the root of the B-Tree
576 hammer_volume_t volume;
578 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
579 KKASSERT(error == 0);
581 hammer_modify_volume_field(cursor->trans, volume,
583 volume->ondisk->vol0_btree_root = nnode->node_offset;
584 hammer_modify_volume_done(volume);
585 hammer_rel_volume(volume, 0);
589 * Now adjust our children's pointers to us.
591 for (i = 0; i < nnode->ondisk->count; ++i) {
592 elm = &nnode->ondisk->elms[i];
593 error = btree_set_parent(cursor->trans, nnode, elm);
595 panic("reblock internal node: fixup problem");
601 * The new node replaces the current node in the cursor. The cursor
602 * expects it to be locked so leave it locked. Discard onode.
604 hammer_cursor_replaced_node(onode, nnode);
605 hammer_delete_node(cursor->trans, onode);
607 if (hammer_debug_general & 0x4000) {
608 kprintf("REBLOCK INODE %016llx -> %016llx\n",
609 (long long)onode->node_offset,
610 (long long)nnode->node_offset);
612 hammer_modify_node_done(nnode);
613 cursor->node = nnode;
615 hammer_unlock(&onode->lock);
616 hammer_rel_node(onode);
619 hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL);