2 * Copyright (c) 2008 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
34 * $DragonFly: src/sys/vfs/hammer/hammer_reblock.c,v 1.34 2008/11/13 02:18:43 dillon Exp $
37 * HAMMER reblocker - This code frees up fragmented physical space
39 * HAMMER only keeps track of free space on a big-block basis. A big-block
40 * containing holes can only be freed by migrating the remaining data in
41 * that big-block into a new big-block, then freeing the big-block.
43 * This function is called from an ioctl or via the hammer support thread.
48 static int hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
49 hammer_cursor_t cursor,
50 hammer_btree_elm_t elm);
51 static int hammer_reblock_data(struct hammer_ioc_reblock *reblock,
52 hammer_cursor_t cursor, hammer_btree_elm_t elm);
53 static int hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
54 hammer_cursor_t cursor, hammer_btree_elm_t elm);
55 static int hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
56 hammer_cursor_t cursor, hammer_btree_elm_t elm);
59 hammer_ioc_reblock(hammer_transaction_t trans, hammer_inode_t ip,
60 struct hammer_ioc_reblock *reblock)
62 struct hammer_cursor cursor;
63 hammer_btree_elm_t elm;
70 * A fill level <= 20% is considered an emergency. free_level is
71 * inverted from fill_level.
73 if (reblock->free_level >= HAMMER_LARGEBLOCK_SIZE * 8 / 10)
74 slop = HAMMER_CHKSPC_EMERGENCY;
76 slop = HAMMER_CHKSPC_REBLOCK;
78 if ((reblock->key_beg.localization | reblock->key_end.localization) &
79 HAMMER_LOCALIZE_PSEUDOFS_MASK) {
82 if (reblock->key_beg.obj_id >= reblock->key_end.obj_id)
84 if (reblock->free_level < 0)
87 reblock->key_cur = reblock->key_beg;
88 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
89 reblock->key_cur.localization += ip->obj_localization;
92 seq = trans->hmp->flusher.act;
94 error = hammer_init_cursor(trans, &cursor, NULL, NULL);
96 hammer_done_cursor(&cursor);
99 cursor.key_beg.localization = reblock->key_cur.localization;
100 cursor.key_beg.obj_id = reblock->key_cur.obj_id;
101 cursor.key_beg.key = HAMMER_MIN_KEY;
102 cursor.key_beg.create_tid = 1;
103 cursor.key_beg.delete_tid = 0;
104 cursor.key_beg.rec_type = HAMMER_MIN_RECTYPE;
105 cursor.key_beg.obj_type = 0;
107 cursor.key_end.localization = (reblock->key_end.localization &
108 HAMMER_LOCALIZE_MASK) +
109 ip->obj_localization;
110 cursor.key_end.obj_id = reblock->key_end.obj_id;
111 cursor.key_end.key = HAMMER_MAX_KEY;
112 cursor.key_end.create_tid = HAMMER_MAX_TID - 1;
113 cursor.key_end.delete_tid = 0;
114 cursor.key_end.rec_type = HAMMER_MAX_RECTYPE;
115 cursor.key_end.obj_type = 0;
117 cursor.flags |= HAMMER_CURSOR_END_INCLUSIVE;
118 cursor.flags |= HAMMER_CURSOR_BACKEND;
121 * This flag allows the btree scan code to return internal nodes,
122 * so we can reblock them in addition to the leafs. Only specify it
123 * if we intend to reblock B-Tree nodes.
125 if (reblock->head.flags & HAMMER_IOC_DO_BTREE)
126 cursor.flags |= HAMMER_CURSOR_REBLOCKING;
128 error = hammer_btree_first(&cursor);
131 * Internal or Leaf node
133 elm = &cursor.node->ondisk->elms[cursor.index];
134 reblock->key_cur.obj_id = elm->base.obj_id;
135 reblock->key_cur.localization = elm->base.localization;
138 * Yield to more important tasks
140 if ((error = hammer_signal_check(trans->hmp)) != 0)
144 * If there is insufficient free space it may be due to
145 * reserved bigblocks, which flushing might fix.
147 * WARNING: See warnings in hammer_unlock_cursor() function.
149 if (hammer_checkspace(trans->hmp, slop)) {
150 if (++checkspace_count == 10) {
154 hammer_unlock_cursor(&cursor);
155 hammer_flusher_wait(trans->hmp, seq);
156 hammer_lock_cursor(&cursor);
157 seq = hammer_flusher_async(trans->hmp, NULL);
162 * Acquiring the sync_lock prevents the operation from
163 * crossing a synchronization boundary.
165 * NOTE: cursor.node may have changed on return.
167 * WARNING: See warnings in hammer_unlock_cursor() function.
169 hammer_sync_lock_sh(trans);
170 error = hammer_reblock_helper(reblock, &cursor, elm);
171 hammer_sync_unlock(trans);
173 while (hammer_flusher_meta_halflimit(trans->hmp) ||
174 hammer_flusher_undo_exhausted(trans, 2)) {
175 hammer_unlock_cursor(&cursor);
176 hammer_flusher_wait(trans->hmp, seq);
177 hammer_lock_cursor(&cursor);
178 seq = hammer_flusher_async_one(trans->hmp);
182 * Setup for iteration, our cursor flags may be modified by
183 * other threads while we are unlocked.
185 cursor.flags |= HAMMER_CURSOR_ATEDISK;
188 * We allocate data buffers, which atm we don't track
189 * dirty levels for because we allow the kernel to write
190 * them. But if we allocate too many we can still deadlock
193 * WARNING: See warnings in hammer_unlock_cursor() function.
194 * (The cursor's node and element may change!)
197 hammer_unlock_cursor(&cursor);
198 bwillwrite(HAMMER_XBUFSIZE);
199 hammer_lock_cursor(&cursor);
203 error = hammer_btree_iterate(&cursor);
209 hammer_done_cursor(&cursor);
210 if (error == EWOULDBLOCK) {
211 hammer_flusher_sync(trans->hmp);
214 if (error == EDEADLK)
216 if (error == EINTR) {
217 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
221 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
226 * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
228 * XXX We have no visibility into internal B-Tree nodes at the moment,
232 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
233 hammer_cursor_t cursor, hammer_btree_elm_t elm)
236 hammer_off_t tmp_offset;
237 struct hammer_btree_leaf_elm leaf;
244 hmp = cursor->trans->hmp;
247 * Reblock data. Note that data embedded in a record is reblocked
248 * by the record reblock code. Data processing only occurs at leaf
249 * nodes and for RECORD element types.
251 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
253 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
255 tmp_offset = elm->leaf.data_offset;
262 * NOTE: Localization restrictions may also have been set-up, we can't
263 * just set the match flags willy-nilly here.
265 switch(elm->leaf.base.rec_type) {
266 case HAMMER_RECTYPE_INODE:
267 iocflags = HAMMER_IOC_DO_INODES;
269 case HAMMER_RECTYPE_EXT:
270 case HAMMER_RECTYPE_FIX:
271 case HAMMER_RECTYPE_PFS:
272 case HAMMER_RECTYPE_DIRENTRY:
273 iocflags = HAMMER_IOC_DO_DIRS;
275 case HAMMER_RECTYPE_DATA:
276 case HAMMER_RECTYPE_DB:
277 iocflags = HAMMER_IOC_DO_DATA;
283 if (reblock->head.flags & iocflags) {
284 ++reblock->data_count;
285 reblock->data_byte_count += elm->leaf.data_len;
286 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
287 if (hammer_debug_general & 0x4000)
288 kprintf("D %6d/%d\n", bytes, reblock->free_level);
289 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
290 bytes >= reblock->free_level) {
292 * This is nasty, the uncache code may have to get
293 * vnode locks and because of that we can't hold
296 * WARNING: See warnings in hammer_unlock_cursor()
300 hammer_unlock_cursor(cursor);
301 hammer_io_direct_uncache(hmp, &leaf);
302 hammer_lock_cursor(cursor);
303 if (cursor->flags & HAMMER_CURSOR_RETEST) {
304 kprintf("hammer: retest after uncache\n");
307 KKASSERT(bcmp(&elm->leaf, &leaf, sizeof(leaf)) == 0);
310 error = hammer_cursor_upgrade(cursor);
312 error = hammer_reblock_data(reblock,
316 ++reblock->data_moves;
317 reblock->data_byte_moves += elm->leaf.data_len;
324 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked
325 * on initial entry only (element 0). An internal node is reblocked
326 * when entered upward from its first leaf node only (also element 0).
327 * Further revisits of the internal node (index > 0) are ignored.
329 tmp_offset = cursor->node->node_offset;
330 if (cursor->index == 0 &&
331 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
332 ++reblock->btree_count;
333 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
334 if (hammer_debug_general & 0x4000)
335 kprintf("B %6d/%d\n", bytes, reblock->free_level);
336 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
337 bytes >= reblock->free_level) {
338 error = hammer_cursor_upgrade(cursor);
341 elm = &cursor->parent->ondisk->elms[cursor->parent_index];
344 switch(cursor->node->ondisk->type) {
345 case HAMMER_BTREE_TYPE_LEAF:
346 error = hammer_reblock_leaf_node(
347 reblock, cursor, elm);
349 case HAMMER_BTREE_TYPE_INTERNAL:
350 error = hammer_reblock_int_node(
351 reblock, cursor, elm);
354 panic("Illegal B-Tree node type");
358 ++reblock->btree_moves;
363 hammer_cursor_downgrade(cursor);
368 * Reblock a record's data. Both the B-Tree element and record pointers
369 * to the data must be adjusted.
372 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
373 hammer_cursor_t cursor, hammer_btree_elm_t elm)
375 struct hammer_buffer *data_buffer = NULL;
376 hammer_off_t ndata_offset;
380 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
381 HAMMER_CURSOR_GET_LEAF);
384 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
385 elm->leaf.base.rec_type,
386 &ndata_offset, &data_buffer,
394 hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
395 bcopy(cursor->data, ndata, elm->leaf.data_len);
396 hammer_modify_buffer_done(data_buffer);
398 hammer_blockmap_free(cursor->trans,
399 elm->leaf.data_offset, elm->leaf.data_len);
401 hammer_modify_node(cursor->trans, cursor->node,
402 &elm->leaf.data_offset, sizeof(hammer_off_t));
403 elm->leaf.data_offset = ndata_offset;
404 hammer_modify_node_done(cursor->node);
408 hammer_rel_buffer(data_buffer, 0);
413 * Reblock a B-Tree leaf node. The parent must be adjusted to point to
414 * the new copy of the leaf node.
416 * elm is a pointer to the parent element pointing at cursor.node.
419 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
420 hammer_cursor_t cursor, hammer_btree_elm_t elm)
427 * Don't supply a hint when allocating the leaf. Fills are done
428 * from the leaf upwards.
430 onode = cursor->node;
431 nnode = hammer_alloc_btree(cursor->trans, 0, &error);
439 hammer_lock_ex(&nnode->lock);
440 hammer_modify_node_noundo(cursor->trans, nnode);
441 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
445 * We are not the root of the B-Tree
447 hammer_modify_node(cursor->trans, cursor->parent,
448 &elm->internal.subtree_offset,
449 sizeof(elm->internal.subtree_offset));
450 elm->internal.subtree_offset = nnode->node_offset;
451 hammer_modify_node_done(cursor->parent);
454 * We are the root of the B-Tree
456 hammer_volume_t volume;
458 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
459 KKASSERT(error == 0);
461 hammer_modify_volume_field(cursor->trans, volume,
463 volume->ondisk->vol0_btree_root = nnode->node_offset;
464 hammer_modify_volume_done(volume);
465 hammer_rel_volume(volume, 0);
468 hammer_cursor_replaced_node(onode, nnode);
469 hammer_delete_node(cursor->trans, onode);
471 if (hammer_debug_general & 0x4000) {
472 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
473 (long long)onode->node_offset,
474 (long long)nnode->node_offset);
476 hammer_modify_node_done(nnode);
477 cursor->node = nnode;
479 hammer_unlock(&onode->lock);
480 hammer_rel_node(onode);
486 * Reblock a B-Tree internal node. The parent must be adjusted to point to
487 * the new copy of the internal node, and the node's children's parent
488 * pointers must also be adjusted to point to the new copy.
490 * elm is a pointer to the parent element pointing at cursor.node.
493 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
494 hammer_cursor_t cursor, hammer_btree_elm_t elm)
496 struct hammer_node_lock lockroot;
503 hammer_node_lock_init(&lockroot, cursor->node);
504 error = hammer_btree_lock_children(cursor, 1, &lockroot);
509 * The internal node is visited after recursing through its
510 * first element. Use the subtree offset allocated for that
511 * element as a hint for allocating the internal node.
513 onode = cursor->node;
514 if (onode->ondisk->count)
515 hint = onode->ondisk->elms[0].internal.subtree_offset;
518 nnode = hammer_alloc_btree(cursor->trans, hint, &error);
524 * Move the node. Adjust the parent's pointer to us first.
526 hammer_lock_ex(&nnode->lock);
527 hammer_modify_node_noundo(cursor->trans, nnode);
528 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
532 * We are not the root of the B-Tree
534 hammer_modify_node(cursor->trans, cursor->parent,
535 &elm->internal.subtree_offset,
536 sizeof(elm->internal.subtree_offset));
537 elm->internal.subtree_offset = nnode->node_offset;
538 hammer_modify_node_done(cursor->parent);
541 * We are the root of the B-Tree
543 hammer_volume_t volume;
545 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
546 KKASSERT(error == 0);
548 hammer_modify_volume_field(cursor->trans, volume,
550 volume->ondisk->vol0_btree_root = nnode->node_offset;
551 hammer_modify_volume_done(volume);
552 hammer_rel_volume(volume, 0);
556 * Now adjust our children's pointers to us.
558 for (i = 0; i < nnode->ondisk->count; ++i) {
559 elm = &nnode->ondisk->elms[i];
560 error = btree_set_parent(cursor->trans, nnode, elm);
562 panic("reblock internal node: fixup problem");
568 * The new node replaces the current node in the cursor. The cursor
569 * expects it to be locked so leave it locked. Discard onode.
571 hammer_cursor_replaced_node(onode, nnode);
572 hammer_delete_node(cursor->trans, onode);
574 if (hammer_debug_general & 0x4000) {
575 kprintf("REBLOCK INODE %016llx -> %016llx\n",
576 (long long)onode->node_offset,
577 (long long)nnode->node_offset);
579 hammer_modify_node_done(nnode);
580 cursor->node = nnode;
582 hammer_unlock(&onode->lock);
583 hammer_rel_node(onode);
586 hammer_btree_unlock_children(cursor, &lockroot);