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 if (reblock->allpfs == 0)
94 reblock->key_cur.localization += ip->obj_localization;
96 key_end_localization = reblock->key_end.localization;
97 key_end_localization &= HAMMER_LOCALIZE_MASK;
98 if (reblock->allpfs == 0)
99 key_end_localization += ip->obj_localization;
101 key_end_localization += ((HAMMER_MAX_PFS - 1) << 16);
103 checkspace_count = 0;
104 seq = trans->hmp->flusher.done;
106 error = hammer_init_cursor(trans, &cursor, NULL, NULL);
108 hammer_done_cursor(&cursor);
111 cursor.key_beg.localization = reblock->key_cur.localization;
112 cursor.key_beg.obj_id = reblock->key_cur.obj_id;
113 cursor.key_beg.key = HAMMER_MIN_KEY;
114 cursor.key_beg.create_tid = 1;
115 cursor.key_beg.delete_tid = 0;
116 cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
117 cursor.key_beg.obj_type = 0;
119 cursor.key_end.localization = key_end_localization;
120 cursor.key_end.obj_id = reblock->key_end.obj_id;
121 cursor.key_end.key = HAMMER_MAX_KEY;
122 cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
123 cursor.key_end.delete_tid = 0;
124 cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
125 cursor.key_end.obj_type = 0;
127 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
128 cursor.flags |= HAMMER_CURSOR_BACKEND;
129 cursor.flags |= HAMMER_CURSOR_NOSWAPCACHE;
132 * This flag allows the btree scan code to return internal nodes,
133 * so we can reblock them in addition to the leafs. Only specify it
134 * if we intend to reblock B-Tree nodes.
136 if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
137 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
139 error = hammer_btree_first(&cursor);
142 * Internal or Leaf node
144 KKASSERT(cursor.index < cursor.node->ondisk->count);
145 elm = &cursor.node->ondisk->elms[cursor.index];
146 reblock->key_cur.obj_id = elm->base.obj_id;
147 reblock->key_cur.localization = elm->base.localization;
150 * Yield to more important tasks
152 if ((error = hammer_signal_check(trans->hmp)) != 0)
156 * If there is insufficient free space it may be due to
157 * reserved big-blocks, which flushing might fix.
159 * We must force a retest in case the unlocked cursor is
160 * moved to the end of the leaf, or moved to an internal
163 * WARNING: See warnings in hammer_unlock_cursor() function.
165 if (hammer_checkspace(trans->hmp, slop)) {
166 if (++checkspace_count == 10) {
170 hammer_unlock_cursor(&cursor);
171 cursor.flags |= HAMMER_CURSOR_RETEST;
172 hammer_flusher_wait(trans->hmp, seq);
173 hammer_lock_cursor(&cursor);
174 seq = hammer_flusher_async(trans->hmp, NULL);
179 * Acquiring the sync_lock prevents the operation from
180 * crossing a synchronization boundary.
182 * NOTE: cursor.node may have changed on return.
184 * WARNING: See warnings in hammer_unlock_cursor() function.
186 hammer_sync_lock_sh(trans);
187 error = hammer_reblock_helper(reblock, &cursor, elm);
188 hammer_sync_unlock(trans);
190 while (hammer_flusher_meta_halflimit(trans->hmp) ||
191 hammer_flusher_undo_exhausted(trans, 2)) {
192 hammer_unlock_cursor(&cursor);
193 hammer_flusher_wait(trans->hmp, seq);
194 hammer_lock_cursor(&cursor);
195 seq = hammer_flusher_async_one(trans->hmp);
199 * Setup for iteration, our cursor flags may be modified by
200 * other threads while we are unlocked.
202 cursor.flags |= HAMMER_CURSOR_ATEDISK;
205 * We allocate data buffers, which atm we don't track
206 * dirty levels for because we allow the kernel to write
207 * them. But if we allocate too many we can still deadlock
210 * WARNING: See warnings in hammer_unlock_cursor() function.
211 * (The cursor's node and element may change!)
214 hammer_unlock_cursor(&cursor);
215 bwillwrite(HAMMER_XBUFSIZE);
216 hammer_lock_cursor(&cursor);
221 error = hammer_btree_iterate(&cursor);
226 hammer_done_cursor(&cursor);
227 if (error == EWOULDBLOCK) {
228 hammer_flusher_sync(trans->hmp);
231 if (error == EDEADLK)
233 if (error == EINTR) {
234 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
238 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
243 * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
245 * XXX We have no visibility into internal B-Tree nodes at the moment,
249 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
250 hammer_cursor_t cursor, hammer_btree_elm_t elm)
253 hammer_off_t tmp_offset;
254 hammer_node_ondisk_t ondisk;
255 struct hammer_btree_leaf_elm leaf;
262 hmp = cursor->trans->hmp;
265 * Reblock data. Note that data embedded in a record is reblocked
266 * by the record reblock code. Data processing only occurs at leaf
267 * nodes and for RECORD element types.
269 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
271 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
273 tmp_offset = elm->leaf.data_offset;
280 * NOTE: Localization restrictions may also have been set-up, we can't
281 * just set the match flags willy-nilly here.
283 switch(elm->leaf.base.rec_type) {
284 case HAMMER_RECTYPE_INODE:
285 case HAMMER_RECTYPE_SNAPSHOT:
286 case HAMMER_RECTYPE_CONFIG:
287 iocflags = HAMMER_IOC_DO_INODES;
289 case HAMMER_RECTYPE_EXT:
290 case HAMMER_RECTYPE_FIX:
291 case HAMMER_RECTYPE_PFS:
292 case HAMMER_RECTYPE_DIRENTRY:
293 iocflags = HAMMER_IOC_DO_DIRS;
295 case HAMMER_RECTYPE_DATA:
296 case HAMMER_RECTYPE_DB:
297 iocflags = HAMMER_IOC_DO_DATA;
303 if (reblock->head.flags & iocflags) {
304 ++reblock->data_count;
305 reblock->data_byte_count += elm->leaf.data_len;
306 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
307 if (hammer_debug_general & 0x4000)
308 kprintf("D %6d/%d\n", bytes, reblock->free_level);
309 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
310 bytes >= reblock->free_level) {
312 * This is nasty, the uncache code may have to get
313 * vnode locks and because of that we can't hold
316 * WARNING: See warnings in hammer_unlock_cursor()
320 hammer_unlock_cursor(cursor);
321 hammer_io_direct_uncache(hmp, &leaf);
322 hammer_lock_cursor(cursor);
325 * elm may have become stale or invalid, reload it.
326 * ondisk variable is temporary only. Note that
327 * cursor->node and thus cursor->node->ondisk may
330 ondisk = cursor->node->ondisk;
331 elm = &ondisk->elms[cursor->index];
332 if (cursor->flags & HAMMER_CURSOR_RETEST) {
333 kprintf("hammer: debug: retest on "
334 "reblocker uncache\n");
336 } else if (ondisk->type != HAMMER_BTREE_TYPE_LEAF ||
337 cursor->index >= ondisk->count) {
338 kprintf("hammer: debug: shifted on "
339 "reblocker uncache\n");
341 } else if (bcmp(&elm->leaf, &leaf, sizeof(leaf))) {
342 kprintf("hammer: debug: changed on "
343 "reblocker uncache\n");
347 error = hammer_cursor_upgrade(cursor);
349 KKASSERT(cursor->index < ondisk->count);
350 error = hammer_reblock_data(reblock,
354 ++reblock->data_moves;
355 reblock->data_byte_moves += elm->leaf.data_len;
362 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked
363 * on initial entry only (element 0). An internal node is reblocked
364 * when entered upward from its first leaf node only (also element 0).
365 * Further revisits of the internal node (index > 0) are ignored.
367 tmp_offset = cursor->node->node_offset;
368 if (cursor->index == 0 &&
369 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
370 ++reblock->btree_count;
371 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
372 if (hammer_debug_general & 0x4000)
373 kprintf("B %6d/%d\n", bytes, reblock->free_level);
374 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
375 bytes >= reblock->free_level) {
376 error = hammer_cursor_upgrade(cursor);
378 if (cursor->parent) {
379 KKASSERT(cursor->parent_index <
380 cursor->parent->ondisk->count);
381 elm = &cursor->parent->ondisk->elms[cursor->parent_index];
385 switch(cursor->node->ondisk->type) {
386 case HAMMER_BTREE_TYPE_LEAF:
387 error = hammer_reblock_leaf_node(
388 reblock, cursor, elm);
390 case HAMMER_BTREE_TYPE_INTERNAL:
391 error = hammer_reblock_int_node(
392 reblock, cursor, elm);
395 panic("Illegal B-Tree node type");
399 ++reblock->btree_moves;
404 hammer_cursor_downgrade(cursor);
409 * Reblock a record's data. Both the B-Tree element and record pointers
410 * to the data must be adjusted.
413 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
414 hammer_cursor_t cursor, hammer_btree_elm_t elm)
416 struct hammer_buffer *data_buffer = NULL;
417 hammer_off_t ndata_offset;
421 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
422 HAMMER_CURSOR_GET_LEAF);
425 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
426 elm->leaf.base.rec_type,
427 &ndata_offset, &data_buffer,
431 hammer_io_notmeta(data_buffer);
434 * Move the data. Note that we must invalidate any cached
435 * data buffer in the cursor before calling blockmap_free.
436 * The blockmap_free may free up the entire big-block and
437 * will not be able to invalidate it if the cursor is holding
438 * a data buffer cached in that big-block.
440 hammer_modify_buffer_noundo(cursor->trans, data_buffer);
441 bcopy(cursor->data, ndata, elm->leaf.data_len);
442 hammer_modify_buffer_done(data_buffer);
443 hammer_cursor_invalidate_cache(cursor);
445 hammer_blockmap_free(cursor->trans,
446 elm->leaf.data_offset, elm->leaf.data_len);
448 hammer_modify_node(cursor->trans, cursor->node,
449 &elm->leaf.data_offset, sizeof(hammer_off_t));
450 elm->leaf.data_offset = ndata_offset;
451 hammer_modify_node_done(cursor->node);
455 hammer_rel_buffer(data_buffer, 0);
460 * Reblock a B-Tree leaf node. The parent must be adjusted to point to
461 * the new copy of the leaf node.
463 * elm is a pointer to the parent element pointing at cursor.node.
466 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
467 hammer_cursor_t cursor, hammer_btree_elm_t elm)
474 * Don't supply a hint when allocating the leaf. Fills are done
475 * from the leaf upwards.
477 onode = cursor->node;
478 nnode = hammer_alloc_btree(cursor->trans, 0, &error);
486 hammer_lock_ex(&nnode->lock);
487 hammer_modify_node_noundo(cursor->trans, nnode);
488 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
492 * We are not the root of the B-Tree
494 hammer_modify_node(cursor->trans, cursor->parent,
495 &elm->internal.subtree_offset,
496 sizeof(elm->internal.subtree_offset));
497 elm->internal.subtree_offset = nnode->node_offset;
498 hammer_modify_node_done(cursor->parent);
501 * We are the root of the B-Tree
503 hammer_volume_t volume;
505 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
506 KKASSERT(error == 0);
508 hammer_modify_volume_field(cursor->trans, volume,
510 volume->ondisk->vol0_btree_root = nnode->node_offset;
511 hammer_modify_volume_done(volume);
512 hammer_rel_volume(volume, 0);
515 hammer_cursor_replaced_node(onode, nnode);
516 hammer_delete_node(cursor->trans, onode);
518 if (hammer_debug_general & 0x4000) {
519 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
520 (long long)onode->node_offset,
521 (long long)nnode->node_offset);
523 hammer_modify_node_done(nnode);
524 cursor->node = nnode;
526 hammer_unlock(&onode->lock);
527 hammer_rel_node(onode);
533 * Reblock a B-Tree internal node. The parent must be adjusted to point to
534 * the new copy of the internal node, and the node's children's parent
535 * pointers must also be adjusted to point to the new copy.
537 * elm is a pointer to the parent element pointing at cursor.node.
540 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
541 hammer_cursor_t cursor, hammer_btree_elm_t elm)
543 struct hammer_node_lock lockroot;
549 hammer_node_lock_init(&lockroot, cursor->node);
550 error = hammer_btree_lock_children(cursor, 1, &lockroot, NULL);
554 onode = cursor->node;
555 nnode = hammer_alloc_btree(cursor->trans, 0, &error);
561 * Move the node. Adjust the parent's pointer to us first.
563 hammer_lock_ex(&nnode->lock);
564 hammer_modify_node_noundo(cursor->trans, nnode);
565 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
569 * We are not the root of the B-Tree
571 hammer_modify_node(cursor->trans, cursor->parent,
572 &elm->internal.subtree_offset,
573 sizeof(elm->internal.subtree_offset));
574 elm->internal.subtree_offset = nnode->node_offset;
575 hammer_modify_node_done(cursor->parent);
578 * We are the root of the B-Tree
580 hammer_volume_t volume;
582 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
583 KKASSERT(error == 0);
585 hammer_modify_volume_field(cursor->trans, volume,
587 volume->ondisk->vol0_btree_root = nnode->node_offset;
588 hammer_modify_volume_done(volume);
589 hammer_rel_volume(volume, 0);
593 * Now adjust our children's pointers to us.
595 for (i = 0; i < nnode->ondisk->count; ++i) {
596 elm = &nnode->ondisk->elms[i];
597 error = btree_set_parent(cursor->trans, nnode, elm);
599 panic("reblock internal node: fixup problem");
605 * The new node replaces the current node in the cursor. The cursor
606 * expects it to be locked so leave it locked. Discard onode.
608 hammer_cursor_replaced_node(onode, nnode);
609 hammer_delete_node(cursor->trans, onode);
611 if (hammer_debug_general & 0x4000) {
612 kprintf("REBLOCK INODE %016llx -> %016llx\n",
613 (long long)onode->node_offset,
614 (long long)nnode->node_offset);
616 hammer_modify_node_done(nnode);
617 cursor->node = nnode;
619 hammer_unlock(&onode->lock);
620 hammer_rel_node(onode);
623 hammer_btree_unlock_children(cursor->trans->hmp, &lockroot, NULL);