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>
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8 * modification, are permitted provided that the following conditions
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12 * notice, this list of conditions and the following disclaimer.
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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 if (hammer_checkspace(trans->hmp, slop)) {
148 if (++checkspace_count == 10) {
152 hammer_unlock_cursor(&cursor);
153 hammer_flusher_wait(trans->hmp, seq);
154 hammer_lock_cursor(&cursor);
155 seq = hammer_flusher_async(trans->hmp, NULL);
160 * Acquiring the sync_lock prevents the operation from
161 * crossing a synchronization boundary.
163 * NOTE: cursor.node may have changed on return.
165 hammer_sync_lock_sh(trans);
166 error = hammer_reblock_helper(reblock, &cursor, elm);
167 hammer_sync_unlock(trans);
169 while (hammer_flusher_meta_halflimit(trans->hmp) ||
170 hammer_flusher_undo_exhausted(trans, 2)) {
171 hammer_unlock_cursor(&cursor);
172 hammer_flusher_wait(trans->hmp, seq);
173 hammer_lock_cursor(&cursor);
174 seq = hammer_flusher_async_one(trans->hmp);
178 * Setup for iteration, our cursor flags may be modified by
179 * other threads while we are unlocked.
181 cursor.flags |= HAMMER_CURSOR_ATEDISK;
184 * We allocate data buffers, which atm we don't track
185 * dirty levels for because we allow the kernel to write
186 * them. But if we allocate too many we can still deadlock
189 * (The cursor's node and element may change!)
192 hammer_unlock_cursor(&cursor);
193 bwillwrite(HAMMER_XBUFSIZE);
194 hammer_lock_cursor(&cursor);
198 error = hammer_btree_iterate(&cursor);
204 hammer_done_cursor(&cursor);
205 if (error == EWOULDBLOCK) {
206 hammer_flusher_sync(trans->hmp);
209 if (error == EDEADLK)
211 if (error == EINTR) {
212 reblock->head.flags |= HAMMER_IOC_HEAD_INTR;
216 reblock->key_cur.localization &= HAMMER_LOCALIZE_MASK;
221 * Reblock the B-Tree (leaf) node, record, and/or data if necessary.
223 * XXX We have no visibility into internal B-Tree nodes at the moment,
227 hammer_reblock_helper(struct hammer_ioc_reblock *reblock,
228 hammer_cursor_t cursor, hammer_btree_elm_t elm)
231 hammer_off_t tmp_offset;
232 struct hammer_btree_leaf_elm leaf;
239 hmp = cursor->trans->hmp;
242 * Reblock data. Note that data embedded in a record is reblocked
243 * by the record reblock code. Data processing only occurs at leaf
244 * nodes and for RECORD element types.
246 if (cursor->node->ondisk->type != HAMMER_BTREE_TYPE_LEAF)
248 if (elm->leaf.base.btype != HAMMER_BTREE_TYPE_RECORD)
250 tmp_offset = elm->leaf.data_offset;
257 * NOTE: Localization restrictions may also have been set-up, we can't
258 * just set the match flags willy-nilly here.
260 switch(elm->leaf.base.rec_type) {
261 case HAMMER_RECTYPE_INODE:
262 iocflags = HAMMER_IOC_DO_INODES;
264 case HAMMER_RECTYPE_EXT:
265 case HAMMER_RECTYPE_FIX:
266 case HAMMER_RECTYPE_PFS:
267 case HAMMER_RECTYPE_DIRENTRY:
268 iocflags = HAMMER_IOC_DO_DIRS;
270 case HAMMER_RECTYPE_DATA:
271 case HAMMER_RECTYPE_DB:
272 iocflags = HAMMER_IOC_DO_DATA;
278 if (reblock->head.flags & iocflags) {
279 ++reblock->data_count;
280 reblock->data_byte_count += elm->leaf.data_len;
281 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
282 if (hammer_debug_general & 0x4000)
283 kprintf("D %6d/%d\n", bytes, reblock->free_level);
284 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
285 bytes >= reblock->free_level) {
287 * This is nasty, the uncache code may have to get
288 * vnode locks and because of that we can't hold
292 hammer_unlock_cursor(cursor);
293 hammer_io_direct_uncache(hmp, &leaf);
294 hammer_lock_cursor(cursor);
295 if (cursor->flags & HAMMER_CURSOR_RETEST) {
296 kprintf("hammer: retest after uncache\n");
299 KKASSERT(bcmp(&elm->leaf, &leaf, sizeof(leaf)) == 0);
302 error = hammer_cursor_upgrade(cursor);
304 error = hammer_reblock_data(reblock,
308 ++reblock->data_moves;
309 reblock->data_byte_moves += elm->leaf.data_len;
316 * Reblock a B-Tree internal or leaf node. A leaf node is reblocked
317 * on initial entry only (element 0). An internal node is reblocked
318 * when entered upward from its first leaf node only (also element 0).
319 * Further revisits of the internal node (index > 0) are ignored.
321 tmp_offset = cursor->node->node_offset;
322 if (cursor->index == 0 &&
323 error == 0 && (reblock->head.flags & HAMMER_IOC_DO_BTREE)) {
324 ++reblock->btree_count;
325 bytes = hammer_blockmap_getfree(hmp, tmp_offset, &cur, &error);
326 if (hammer_debug_general & 0x4000)
327 kprintf("B %6d/%d\n", bytes, reblock->free_level);
328 if (error == 0 && (cur == 0 || reblock->free_level == 0) &&
329 bytes >= reblock->free_level) {
330 error = hammer_cursor_upgrade(cursor);
333 elm = &cursor->parent->ondisk->elms[cursor->parent_index];
336 switch(cursor->node->ondisk->type) {
337 case HAMMER_BTREE_TYPE_LEAF:
338 error = hammer_reblock_leaf_node(
339 reblock, cursor, elm);
341 case HAMMER_BTREE_TYPE_INTERNAL:
342 error = hammer_reblock_int_node(
343 reblock, cursor, elm);
346 panic("Illegal B-Tree node type");
350 ++reblock->btree_moves;
355 hammer_cursor_downgrade(cursor);
360 * Reblock a record's data. Both the B-Tree element and record pointers
361 * to the data must be adjusted.
364 hammer_reblock_data(struct hammer_ioc_reblock *reblock,
365 hammer_cursor_t cursor, hammer_btree_elm_t elm)
367 struct hammer_buffer *data_buffer = NULL;
368 hammer_off_t ndata_offset;
372 error = hammer_btree_extract(cursor, HAMMER_CURSOR_GET_DATA |
373 HAMMER_CURSOR_GET_LEAF);
376 ndata = hammer_alloc_data(cursor->trans, elm->leaf.data_len,
377 elm->leaf.base.rec_type,
378 &ndata_offset, &data_buffer, &error);
385 hammer_modify_buffer(cursor->trans, data_buffer, NULL, 0);
386 bcopy(cursor->data, ndata, elm->leaf.data_len);
387 hammer_modify_buffer_done(data_buffer);
389 hammer_blockmap_free(cursor->trans,
390 elm->leaf.data_offset, elm->leaf.data_len);
392 hammer_modify_node(cursor->trans, cursor->node,
393 &elm->leaf.data_offset, sizeof(hammer_off_t));
394 elm->leaf.data_offset = ndata_offset;
395 hammer_modify_node_done(cursor->node);
399 hammer_rel_buffer(data_buffer, 0);
404 * Reblock a B-Tree leaf node. The parent must be adjusted to point to
405 * the new copy of the leaf node.
407 * elm is a pointer to the parent element pointing at cursor.node.
410 hammer_reblock_leaf_node(struct hammer_ioc_reblock *reblock,
411 hammer_cursor_t cursor, hammer_btree_elm_t elm)
417 onode = cursor->node;
418 nnode = hammer_alloc_btree(cursor->trans, &error);
426 hammer_lock_ex(&nnode->lock);
427 hammer_modify_node_noundo(cursor->trans, nnode);
428 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
432 * We are not the root of the B-Tree
434 hammer_modify_node(cursor->trans, cursor->parent,
435 &elm->internal.subtree_offset,
436 sizeof(elm->internal.subtree_offset));
437 elm->internal.subtree_offset = nnode->node_offset;
438 hammer_modify_node_done(cursor->parent);
441 * We are the root of the B-Tree
443 hammer_volume_t volume;
445 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
446 KKASSERT(error == 0);
448 hammer_modify_volume_field(cursor->trans, volume,
450 volume->ondisk->vol0_btree_root = nnode->node_offset;
451 hammer_modify_volume_done(volume);
452 hammer_rel_volume(volume, 0);
455 hammer_cursor_replaced_node(onode, nnode);
456 hammer_delete_node(cursor->trans, onode);
458 if (hammer_debug_general & 0x4000) {
459 kprintf("REBLOCK LNODE %016llx -> %016llx\n",
460 onode->node_offset, nnode->node_offset);
462 hammer_modify_node_done(nnode);
463 cursor->node = nnode;
465 hammer_unlock(&onode->lock);
466 hammer_rel_node(onode);
472 * Reblock a B-Tree internal node. The parent must be adjusted to point to
473 * the new copy of the internal node, and the node's children's parent
474 * pointers must also be adjusted to point to the new copy.
476 * elm is a pointer to the parent element pointing at cursor.node.
479 hammer_reblock_int_node(struct hammer_ioc_reblock *reblock,
480 hammer_cursor_t cursor, hammer_btree_elm_t elm)
482 struct hammer_node_lock lockroot;
488 hammer_node_lock_init(&lockroot, cursor->node);
489 error = hammer_btree_lock_children(cursor, 1, &lockroot);
493 onode = cursor->node;
494 nnode = hammer_alloc_btree(cursor->trans, &error);
500 * Move the node. Adjust the parent's pointer to us first.
502 hammer_lock_ex(&nnode->lock);
503 hammer_modify_node_noundo(cursor->trans, nnode);
504 bcopy(onode->ondisk, nnode->ondisk, sizeof(*nnode->ondisk));
508 * We are not the root of the B-Tree
510 hammer_modify_node(cursor->trans, cursor->parent,
511 &elm->internal.subtree_offset,
512 sizeof(elm->internal.subtree_offset));
513 elm->internal.subtree_offset = nnode->node_offset;
514 hammer_modify_node_done(cursor->parent);
517 * We are the root of the B-Tree
519 hammer_volume_t volume;
521 volume = hammer_get_root_volume(cursor->trans->hmp, &error);
522 KKASSERT(error == 0);
524 hammer_modify_volume_field(cursor->trans, volume,
526 volume->ondisk->vol0_btree_root = nnode->node_offset;
527 hammer_modify_volume_done(volume);
528 hammer_rel_volume(volume, 0);
532 * Now adjust our children's pointers to us.
534 for (i = 0; i < nnode->ondisk->count; ++i) {
535 elm = &nnode->ondisk->elms[i];
536 error = btree_set_parent(cursor->trans, nnode, elm);
538 panic("reblock internal node: fixup problem");
544 * The new node replaces the current node in the cursor. The cursor
545 * expects it to be locked so leave it locked. Discard onode.
547 hammer_cursor_replaced_node(onode, nnode);
548 hammer_delete_node(cursor->trans, onode);
550 if (hammer_debug_general & 0x4000) {
551 kprintf("REBLOCK INODE %016llx -> %016llx\n",
552 onode->node_offset, nnode->node_offset);
554 hammer_modify_node_done(nnode);
555 cursor->node = nnode;
557 hammer_unlock(&onode->lock);
558 hammer_rel_node(onode);
561 hammer_btree_unlock_children(cursor, &lockroot);