2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
21 #include "transaction.h"
22 #include "print-tree.h"
24 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
25 *root, struct btrfs_path *path, int level);
26 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_key *ins_key,
28 struct btrfs_path *path, int data_size);
29 static int push_node_left(struct btrfs_trans_handle *trans,
30 struct btrfs_root *root, struct extent_buffer *dst,
31 struct extent_buffer *src);
32 static int balance_node_right(struct btrfs_trans_handle *trans,
33 struct btrfs_root *root,
34 struct extent_buffer *dst_buf,
35 struct extent_buffer *src_buf);
36 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
37 struct btrfs_path *path, int level, int slot);
39 inline void btrfs_init_path(struct btrfs_path *p)
41 memset(p, 0, sizeof(*p));
44 struct btrfs_path *btrfs_alloc_path(void)
46 struct btrfs_path *path;
47 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
49 btrfs_init_path(path);
55 void btrfs_free_path(struct btrfs_path *p)
57 btrfs_release_path(NULL, p);
58 kmem_cache_free(btrfs_path_cachep, p);
61 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
64 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
67 free_extent_buffer(p->nodes[i]);
69 memset(p, 0, sizeof(*p));
72 static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
73 struct btrfs_root *root,
74 struct extent_buffer *buf,
75 struct extent_buffer *parent, int parent_slot,
76 struct extent_buffer **cow_ret,
77 u64 search_start, u64 empty_size)
79 struct extent_buffer *cow;
81 int different_trans = 0;
83 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
85 cow = btrfs_alloc_free_block(trans, root, buf->len,
86 search_start, empty_size);
90 copy_extent_buffer(cow, buf, 0, 0, cow->len);
91 btrfs_set_header_bytenr(cow, cow->start);
92 btrfs_set_header_generation(cow, trans->transid);
93 btrfs_set_header_owner(cow, root->root_key.objectid);
95 WARN_ON(btrfs_header_generation(buf) > trans->transid);
96 if (btrfs_header_generation(buf) != trans->transid) {
98 ret = btrfs_inc_ref(trans, root, buf);
102 clean_tree_block(trans, root, buf);
105 if (buf == root->node) {
107 extent_buffer_get(cow);
108 if (buf != root->commit_root) {
109 btrfs_free_extent(trans, root, buf->start,
112 free_extent_buffer(buf);
114 btrfs_set_node_blockptr(parent, parent_slot,
116 btrfs_mark_buffer_dirty(parent);
117 WARN_ON(btrfs_header_generation(parent) != trans->transid);
118 btrfs_free_extent(trans, root, buf->start, buf->len, 1);
120 free_extent_buffer(buf);
121 btrfs_mark_buffer_dirty(cow);
126 int btrfs_cow_block(struct btrfs_trans_handle *trans,
127 struct btrfs_root *root, struct extent_buffer *buf,
128 struct extent_buffer *parent, int parent_slot,
129 struct extent_buffer **cow_ret)
133 if (trans->transaction != root->fs_info->running_transaction) {
134 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
135 root->fs_info->running_transaction->transid);
138 if (trans->transid != root->fs_info->generation) {
139 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
140 root->fs_info->generation);
143 if (btrfs_header_generation(buf) == trans->transid) {
148 search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
149 ret = __btrfs_cow_block(trans, root, buf, parent,
150 parent_slot, cow_ret, search_start, 0);
154 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
156 if (blocknr < other && other - (blocknr + blocksize) < 32768)
158 if (blocknr > other && blocknr - (other + blocksize) < 32768)
163 static int should_defrag_leaf(struct extent_buffer *leaf)
165 struct btrfs_key key;
168 if (btrfs_buffer_defrag(leaf))
171 nritems = btrfs_header_nritems(leaf);
175 btrfs_item_key_to_cpu(leaf, &key, 0);
176 if (key.type == BTRFS_DIR_ITEM_KEY)
180 btrfs_item_key_to_cpu(leaf, &key, nritems - 1);
181 if (key.type == BTRFS_DIR_ITEM_KEY)
184 btrfs_item_key_to_cpu(leaf, &key, nritems / 2);
185 if (key.type == BTRFS_DIR_ITEM_KEY)
191 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
192 struct btrfs_root *root, struct extent_buffer *parent,
193 int cache_only, u64 *last_ret)
195 struct extent_buffer *cur;
196 struct extent_buffer *tmp;
198 u64 search_start = *last_ret;
210 if (trans->transaction != root->fs_info->running_transaction) {
211 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
212 root->fs_info->running_transaction->transid);
215 if (trans->transid != root->fs_info->generation) {
216 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
217 root->fs_info->generation);
220 if (btrfs_buffer_defrag_done(parent))
223 parent_nritems = btrfs_header_nritems(parent);
224 parent_level = btrfs_header_level(parent);
225 blocksize = btrfs_level_size(root, parent_level - 1);
228 end_slot = parent_nritems;
230 if (parent_nritems == 1)
233 for (i = start_slot; i < end_slot; i++) {
235 blocknr = btrfs_node_blockptr(parent, i);
237 last_block = blocknr;
239 other = btrfs_node_blockptr(parent, i - 1);
240 close = close_blocks(blocknr, other, blocksize);
242 if (close && i < end_slot - 1) {
243 other = btrfs_node_blockptr(parent, i + 1);
244 close = close_blocks(blocknr, other, blocksize);
247 last_block = blocknr;
251 cur = btrfs_find_tree_block(root, blocknr, blocksize);
253 uptodate = btrfs_buffer_uptodate(cur);
256 if (!cur || !uptodate ||
257 (parent_level != 1 && !btrfs_buffer_defrag(cur)) ||
258 (parent_level == 1 && !should_defrag_leaf(cur))) {
260 free_extent_buffer(cur);
264 cur = read_tree_block(root, blocknr,
266 } else if (!uptodate) {
267 btrfs_read_buffer(cur);
270 if (search_start == 0)
271 search_start = last_block;
273 err = __btrfs_cow_block(trans, root, cur, parent, i,
276 (end_slot - i) * blocksize));
278 free_extent_buffer(cur);
281 search_start = tmp->start;
282 *last_ret = search_start;
283 if (parent_level == 1)
284 btrfs_clear_buffer_defrag(tmp);
285 btrfs_set_buffer_defrag_done(tmp);
286 free_extent_buffer(tmp);
292 * The leaf data grows from end-to-front in the node.
293 * this returns the address of the start of the last item,
294 * which is the stop of the leaf data stack
296 static inline unsigned int leaf_data_end(struct btrfs_root *root,
297 struct extent_buffer *leaf)
299 u32 nr = btrfs_header_nritems(leaf);
301 return BTRFS_LEAF_DATA_SIZE(root);
302 return btrfs_item_offset_nr(leaf, nr - 1);
306 * compare two keys in a memcmp fashion
308 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
312 btrfs_disk_key_to_cpu(&k1, disk);
314 if (k1.objectid > k2->objectid)
316 if (k1.objectid < k2->objectid)
318 if (k1.type > k2->type)
320 if (k1.type < k2->type)
322 if (k1.offset > k2->offset)
324 if (k1.offset < k2->offset)
329 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
332 struct extent_buffer *parent = NULL;
333 struct extent_buffer *node = path->nodes[level];
334 struct btrfs_disk_key parent_key;
335 struct btrfs_disk_key node_key;
338 struct btrfs_key cpukey;
339 u32 nritems = btrfs_header_nritems(node);
341 if (path->nodes[level + 1])
342 parent = path->nodes[level + 1];
344 slot = path->slots[level];
345 BUG_ON(nritems == 0);
347 parent_slot = path->slots[level + 1];
348 btrfs_node_key(parent, &parent_key, parent_slot);
349 btrfs_node_key(node, &node_key, 0);
350 BUG_ON(memcmp(&parent_key, &node_key,
351 sizeof(struct btrfs_disk_key)));
352 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
353 btrfs_header_bytenr(node));
355 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
357 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
358 btrfs_node_key(node, &node_key, slot);
359 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
361 if (slot < nritems - 1) {
362 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
363 btrfs_node_key(node, &node_key, slot);
364 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
369 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
372 struct extent_buffer *leaf = path->nodes[level];
373 struct extent_buffer *parent = NULL;
375 struct btrfs_key cpukey;
376 struct btrfs_disk_key parent_key;
377 struct btrfs_disk_key leaf_key;
378 int slot = path->slots[0];
380 u32 nritems = btrfs_header_nritems(leaf);
382 if (path->nodes[level + 1])
383 parent = path->nodes[level + 1];
389 parent_slot = path->slots[level + 1];
390 btrfs_node_key(parent, &parent_key, parent_slot);
391 btrfs_item_key(leaf, &leaf_key, 0);
393 BUG_ON(memcmp(&parent_key, &leaf_key,
394 sizeof(struct btrfs_disk_key)));
395 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
396 btrfs_header_bytenr(leaf));
399 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
400 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
401 btrfs_item_key(leaf, &leaf_key, i);
402 if (comp_keys(&leaf_key, &cpukey) >= 0) {
403 btrfs_print_leaf(root, leaf);
404 printk("slot %d offset bad key\n", i);
407 if (btrfs_item_offset_nr(leaf, i) !=
408 btrfs_item_end_nr(leaf, i + 1)) {
409 btrfs_print_leaf(root, leaf);
410 printk("slot %d offset bad\n", i);
414 if (btrfs_item_offset_nr(leaf, i) +
415 btrfs_item_size_nr(leaf, i) !=
416 BTRFS_LEAF_DATA_SIZE(root)) {
417 btrfs_print_leaf(root, leaf);
418 printk("slot %d first offset bad\n", i);
424 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
425 btrfs_print_leaf(root, leaf);
426 printk("slot %d bad size \n", nritems - 1);
431 if (slot != 0 && slot < nritems - 1) {
432 btrfs_item_key(leaf, &leaf_key, slot);
433 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
434 if (comp_keys(&leaf_key, &cpukey) <= 0) {
435 btrfs_print_leaf(root, leaf);
436 printk("slot %d offset bad key\n", slot);
439 if (btrfs_item_offset_nr(leaf, slot - 1) !=
440 btrfs_item_end_nr(leaf, slot)) {
441 btrfs_print_leaf(root, leaf);
442 printk("slot %d offset bad\n", slot);
446 if (slot < nritems - 1) {
447 btrfs_item_key(leaf, &leaf_key, slot);
448 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
449 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
450 if (btrfs_item_offset_nr(leaf, slot) !=
451 btrfs_item_end_nr(leaf, slot + 1)) {
452 btrfs_print_leaf(root, leaf);
453 printk("slot %d offset bad\n", slot);
457 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
458 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
462 static int check_block(struct btrfs_root *root, struct btrfs_path *path,
467 struct extent_buffer *buf = path->nodes[level];
469 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
470 (unsigned long)btrfs_header_fsid(buf),
472 printk("warning bad block %Lu\n", buf->start);
477 return check_leaf(root, path, level);
478 return check_node(root, path, level);
482 * search for key in the extent_buffer. The items start at offset p,
483 * and they are item_size apart. There are 'max' items in p.
485 * the slot in the array is returned via slot, and it points to
486 * the place where you would insert key if it is not found in
489 * slot may point to max if the key is bigger than all of the keys
491 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
492 int item_size, struct btrfs_key *key,
499 struct btrfs_disk_key *tmp = NULL;
500 struct btrfs_disk_key unaligned;
501 unsigned long offset;
502 char *map_token = NULL;
504 unsigned long map_start = 0;
505 unsigned long map_len = 0;
509 mid = (low + high) / 2;
510 offset = p + mid * item_size;
512 if (!map_token || offset < map_start ||
513 (offset + sizeof(struct btrfs_disk_key)) >
514 map_start + map_len) {
516 unmap_extent_buffer(eb, map_token, KM_USER0);
519 err = map_extent_buffer(eb, offset,
520 sizeof(struct btrfs_disk_key),
522 &map_start, &map_len, KM_USER0);
525 tmp = (struct btrfs_disk_key *)(kaddr + offset -
528 read_extent_buffer(eb, &unaligned,
529 offset, sizeof(unaligned));
534 tmp = (struct btrfs_disk_key *)(kaddr + offset -
537 ret = comp_keys(tmp, key);
546 unmap_extent_buffer(eb, map_token, KM_USER0);
552 unmap_extent_buffer(eb, map_token, KM_USER0);
557 * simple bin_search frontend that does the right thing for
560 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
561 int level, int *slot)
564 return generic_bin_search(eb,
565 offsetof(struct btrfs_leaf, items),
566 sizeof(struct btrfs_item),
567 key, btrfs_header_nritems(eb),
570 return generic_bin_search(eb,
571 offsetof(struct btrfs_node, ptrs),
572 sizeof(struct btrfs_key_ptr),
573 key, btrfs_header_nritems(eb),
579 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
580 struct extent_buffer *parent, int slot)
584 if (slot >= btrfs_header_nritems(parent))
586 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
587 btrfs_level_size(root, btrfs_header_level(parent) - 1));
590 static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
591 *root, struct btrfs_path *path, int level)
593 struct extent_buffer *right = NULL;
594 struct extent_buffer *mid;
595 struct extent_buffer *left = NULL;
596 struct extent_buffer *parent = NULL;
600 int orig_slot = path->slots[level];
601 int err_on_enospc = 0;
607 mid = path->nodes[level];
608 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
610 if (level < BTRFS_MAX_LEVEL - 1)
611 parent = path->nodes[level + 1];
612 pslot = path->slots[level + 1];
615 * deal with the case where there is only one pointer in the root
616 * by promoting the node below to a root
619 struct extent_buffer *child;
621 if (btrfs_header_nritems(mid) != 1)
624 /* promote the child to a root */
625 child = read_node_slot(root, mid, 0);
628 path->nodes[level] = NULL;
629 clean_tree_block(trans, root, mid);
630 wait_on_tree_block_writeback(root, mid);
631 /* once for the path */
632 free_extent_buffer(mid);
633 ret = btrfs_free_extent(trans, root, mid->start, mid->len, 1);
634 /* once for the root ptr */
635 free_extent_buffer(mid);
638 if (btrfs_header_nritems(mid) >
639 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
642 if (btrfs_header_nritems(mid) < 2)
645 left = read_node_slot(root, parent, pslot - 1);
647 wret = btrfs_cow_block(trans, root, left,
648 parent, pslot - 1, &left);
654 right = read_node_slot(root, parent, pslot + 1);
656 wret = btrfs_cow_block(trans, root, right,
657 parent, pslot + 1, &right);
664 /* first, try to make some room in the middle buffer */
666 orig_slot += btrfs_header_nritems(left);
667 wret = push_node_left(trans, root, left, mid);
670 if (btrfs_header_nritems(mid) < 2)
675 * then try to empty the right most buffer into the middle
678 wret = push_node_left(trans, root, mid, right);
679 if (wret < 0 && wret != -ENOSPC)
681 if (btrfs_header_nritems(right) == 0) {
682 u64 bytenr = right->start;
683 u32 blocksize = right->len;
685 clean_tree_block(trans, root, right);
686 wait_on_tree_block_writeback(root, right);
687 free_extent_buffer(right);
689 wret = del_ptr(trans, root, path, level + 1, pslot +
693 wret = btrfs_free_extent(trans, root, bytenr,
698 struct btrfs_disk_key right_key;
699 btrfs_node_key(right, &right_key, 0);
700 btrfs_set_node_key(parent, &right_key, pslot + 1);
701 btrfs_mark_buffer_dirty(parent);
704 if (btrfs_header_nritems(mid) == 1) {
706 * we're not allowed to leave a node with one item in the
707 * tree during a delete. A deletion from lower in the tree
708 * could try to delete the only pointer in this node.
709 * So, pull some keys from the left.
710 * There has to be a left pointer at this point because
711 * otherwise we would have pulled some pointers from the
715 wret = balance_node_right(trans, root, mid, left);
722 if (btrfs_header_nritems(mid) == 0) {
723 /* we've managed to empty the middle node, drop it */
724 u64 bytenr = mid->start;
725 u32 blocksize = mid->len;
726 clean_tree_block(trans, root, mid);
727 wait_on_tree_block_writeback(root, mid);
728 free_extent_buffer(mid);
730 wret = del_ptr(trans, root, path, level + 1, pslot);
733 wret = btrfs_free_extent(trans, root, bytenr, blocksize, 1);
737 /* update the parent key to reflect our changes */
738 struct btrfs_disk_key mid_key;
739 btrfs_node_key(mid, &mid_key, 0);
740 btrfs_set_node_key(parent, &mid_key, pslot);
741 btrfs_mark_buffer_dirty(parent);
744 /* update the path */
746 if (btrfs_header_nritems(left) > orig_slot) {
747 extent_buffer_get(left);
748 path->nodes[level] = left;
749 path->slots[level + 1] -= 1;
750 path->slots[level] = orig_slot;
752 free_extent_buffer(mid);
754 orig_slot -= btrfs_header_nritems(left);
755 path->slots[level] = orig_slot;
758 /* double check we haven't messed things up */
759 check_block(root, path, level);
761 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
765 free_extent_buffer(right);
767 free_extent_buffer(left);
771 /* returns zero if the push worked, non-zero otherwise */
772 static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
773 struct btrfs_root *root,
774 struct btrfs_path *path, int level)
776 struct extent_buffer *right = NULL;
777 struct extent_buffer *mid;
778 struct extent_buffer *left = NULL;
779 struct extent_buffer *parent = NULL;
783 int orig_slot = path->slots[level];
789 mid = path->nodes[level];
790 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
792 if (level < BTRFS_MAX_LEVEL - 1)
793 parent = path->nodes[level + 1];
794 pslot = path->slots[level + 1];
799 left = read_node_slot(root, parent, pslot - 1);
801 /* first, try to make some room in the middle buffer */
804 left_nr = btrfs_header_nritems(left);
805 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
808 ret = btrfs_cow_block(trans, root, left, parent,
813 wret = push_node_left(trans, root,
820 struct btrfs_disk_key disk_key;
821 orig_slot += left_nr;
822 btrfs_node_key(mid, &disk_key, 0);
823 btrfs_set_node_key(parent, &disk_key, pslot);
824 btrfs_mark_buffer_dirty(parent);
825 if (btrfs_header_nritems(left) > orig_slot) {
826 path->nodes[level] = left;
827 path->slots[level + 1] -= 1;
828 path->slots[level] = orig_slot;
829 free_extent_buffer(mid);
832 btrfs_header_nritems(left);
833 path->slots[level] = orig_slot;
834 free_extent_buffer(left);
838 free_extent_buffer(left);
840 right= read_node_slot(root, parent, pslot + 1);
843 * then try to empty the right most buffer into the middle
847 right_nr = btrfs_header_nritems(right);
848 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
851 ret = btrfs_cow_block(trans, root, right,
857 wret = balance_node_right(trans, root,
864 struct btrfs_disk_key disk_key;
866 btrfs_node_key(right, &disk_key, 0);
867 btrfs_set_node_key(parent, &disk_key, pslot + 1);
868 btrfs_mark_buffer_dirty(parent);
870 if (btrfs_header_nritems(mid) <= orig_slot) {
871 path->nodes[level] = right;
872 path->slots[level + 1] += 1;
873 path->slots[level] = orig_slot -
874 btrfs_header_nritems(mid);
875 free_extent_buffer(mid);
877 free_extent_buffer(right);
881 free_extent_buffer(right);
887 * readahead one full node of leaves
889 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
892 struct extent_buffer *node;
898 int direction = path->reada;
899 struct extent_buffer *eb;
907 if (!path->nodes[level])
910 node = path->nodes[level];
911 search = btrfs_node_blockptr(node, slot);
912 blocksize = btrfs_level_size(root, level - 1);
913 eb = btrfs_find_tree_block(root, search, blocksize);
915 free_extent_buffer(eb);
919 highest_read = search;
920 lowest_read = search;
922 nritems = btrfs_header_nritems(node);
929 } else if (direction > 0) {
934 search = btrfs_node_blockptr(node, nr);
935 if ((search >= lowest_read && search <= highest_read) ||
936 (search < lowest_read && lowest_read - search <= 32768) ||
937 (search > highest_read && search - highest_read <= 32768)) {
938 readahead_tree_block(root, search, blocksize);
942 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
944 if(nread > (1024 * 1024) || nscan > 128)
947 if (search < lowest_read)
948 lowest_read = search;
949 if (search > highest_read)
950 highest_read = search;
954 * look for key in the tree. path is filled in with nodes along the way
955 * if key is found, we return zero and you can find the item in the leaf
956 * level of the path (level 0)
958 * If the key isn't found, the path points to the slot where it should
959 * be inserted, and 1 is returned. If there are other errors during the
960 * search a negative error number is returned.
962 * if ins_len > 0, nodes and leaves will be split as we walk down the
963 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
966 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
967 *root, struct btrfs_key *key, struct btrfs_path *p, int
970 struct extent_buffer *b;
975 int should_reada = p->reada;
978 lowest_level = p->lowest_level;
979 WARN_ON(lowest_level && ins_len);
980 WARN_ON(p->nodes[0] != NULL);
981 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
984 extent_buffer_get(b);
986 level = btrfs_header_level(b);
989 wret = btrfs_cow_block(trans, root, b,
994 free_extent_buffer(b);
998 BUG_ON(!cow && ins_len);
999 if (level != btrfs_header_level(b))
1001 level = btrfs_header_level(b);
1002 p->nodes[level] = b;
1003 ret = check_block(root, p, level);
1006 ret = bin_search(b, key, level, &slot);
1008 if (ret && slot > 0)
1010 p->slots[level] = slot;
1011 if (ins_len > 0 && btrfs_header_nritems(b) >=
1012 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1013 int sret = split_node(trans, root, p, level);
1017 b = p->nodes[level];
1018 slot = p->slots[level];
1019 } else if (ins_len < 0) {
1020 int sret = balance_level(trans, root, p,
1024 b = p->nodes[level];
1026 btrfs_release_path(NULL, p);
1029 slot = p->slots[level];
1030 BUG_ON(btrfs_header_nritems(b) == 1);
1032 /* this is only true while dropping a snapshot */
1033 if (level == lowest_level)
1035 bytenr = btrfs_node_blockptr(b, slot);
1037 reada_for_search(root, p, level, slot);
1038 b = read_tree_block(root, bytenr,
1039 btrfs_level_size(root, level - 1));
1041 p->slots[level] = slot;
1042 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1043 sizeof(struct btrfs_item) + ins_len) {
1044 int sret = split_leaf(trans, root, key,
1057 * adjust the pointers going up the tree, starting at level
1058 * making sure the right key of each node is points to 'key'.
1059 * This is used after shifting pointers to the left, so it stops
1060 * fixing up pointers when a given leaf/node is not in slot 0 of the
1063 * If this fails to write a tree block, it returns -1, but continues
1064 * fixing up the blocks in ram so the tree is consistent.
1066 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1067 struct btrfs_root *root, struct btrfs_path *path,
1068 struct btrfs_disk_key *key, int level)
1072 struct extent_buffer *t;
1074 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1075 int tslot = path->slots[i];
1076 if (!path->nodes[i])
1079 btrfs_set_node_key(t, key, tslot);
1080 btrfs_mark_buffer_dirty(path->nodes[i]);
1088 * try to push data from one node into the next node left in the
1091 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1092 * error, and > 0 if there was no room in the left hand block.
1094 static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
1095 *root, struct extent_buffer *dst,
1096 struct extent_buffer *src)
1103 src_nritems = btrfs_header_nritems(src);
1104 dst_nritems = btrfs_header_nritems(dst);
1105 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1107 if (push_items <= 0) {
1111 if (src_nritems < push_items)
1112 push_items = src_nritems;
1114 copy_extent_buffer(dst, src,
1115 btrfs_node_key_ptr_offset(dst_nritems),
1116 btrfs_node_key_ptr_offset(0),
1117 push_items * sizeof(struct btrfs_key_ptr));
1119 if (push_items < src_nritems) {
1120 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1121 btrfs_node_key_ptr_offset(push_items),
1122 (src_nritems - push_items) *
1123 sizeof(struct btrfs_key_ptr));
1125 btrfs_set_header_nritems(src, src_nritems - push_items);
1126 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1127 btrfs_mark_buffer_dirty(src);
1128 btrfs_mark_buffer_dirty(dst);
1133 * try to push data from one node into the next node right in the
1136 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1137 * error, and > 0 if there was no room in the right hand block.
1139 * this will only push up to 1/2 the contents of the left node over
1141 static int balance_node_right(struct btrfs_trans_handle *trans,
1142 struct btrfs_root *root,
1143 struct extent_buffer *dst,
1144 struct extent_buffer *src)
1152 src_nritems = btrfs_header_nritems(src);
1153 dst_nritems = btrfs_header_nritems(dst);
1154 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1155 if (push_items <= 0)
1158 max_push = src_nritems / 2 + 1;
1159 /* don't try to empty the node */
1160 if (max_push >= src_nritems)
1163 if (max_push < push_items)
1164 push_items = max_push;
1166 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1167 btrfs_node_key_ptr_offset(0),
1169 sizeof(struct btrfs_key_ptr));
1171 copy_extent_buffer(dst, src,
1172 btrfs_node_key_ptr_offset(0),
1173 btrfs_node_key_ptr_offset(src_nritems - push_items),
1174 push_items * sizeof(struct btrfs_key_ptr));
1176 btrfs_set_header_nritems(src, src_nritems - push_items);
1177 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1179 btrfs_mark_buffer_dirty(src);
1180 btrfs_mark_buffer_dirty(dst);
1185 * helper function to insert a new root level in the tree.
1186 * A new node is allocated, and a single item is inserted to
1187 * point to the existing root
1189 * returns zero on success or < 0 on failure.
1191 static int insert_new_root(struct btrfs_trans_handle *trans,
1192 struct btrfs_root *root,
1193 struct btrfs_path *path, int level)
1195 struct extent_buffer *lower;
1196 struct extent_buffer *c;
1197 struct btrfs_disk_key lower_key;
1199 BUG_ON(path->nodes[level]);
1200 BUG_ON(path->nodes[level-1] != root->node);
1202 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1203 root->node->start, 0);
1206 memset_extent_buffer(c, 0, 0, root->nodesize);
1207 btrfs_set_header_nritems(c, 1);
1208 btrfs_set_header_level(c, level);
1209 btrfs_set_header_bytenr(c, c->start);
1210 btrfs_set_header_generation(c, trans->transid);
1211 btrfs_set_header_owner(c, root->root_key.objectid);
1212 lower = path->nodes[level-1];
1214 write_extent_buffer(c, root->fs_info->fsid,
1215 (unsigned long)btrfs_header_fsid(c),
1218 btrfs_item_key(lower, &lower_key, 0);
1220 btrfs_node_key(lower, &lower_key, 0);
1221 btrfs_set_node_key(c, &lower_key, 0);
1222 btrfs_set_node_blockptr(c, 0, lower->start);
1224 btrfs_mark_buffer_dirty(c);
1226 /* the super has an extra ref to root->node */
1227 free_extent_buffer(root->node);
1229 extent_buffer_get(c);
1230 path->nodes[level] = c;
1231 path->slots[level] = 0;
1236 * worker function to insert a single pointer in a node.
1237 * the node should have enough room for the pointer already
1239 * slot and level indicate where you want the key to go, and
1240 * blocknr is the block the key points to.
1242 * returns zero on success and < 0 on any error
1244 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1245 *root, struct btrfs_path *path, struct btrfs_disk_key
1246 *key, u64 bytenr, int slot, int level)
1248 struct extent_buffer *lower;
1251 BUG_ON(!path->nodes[level]);
1252 lower = path->nodes[level];
1253 nritems = btrfs_header_nritems(lower);
1256 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1258 if (slot != nritems) {
1259 memmove_extent_buffer(lower,
1260 btrfs_node_key_ptr_offset(slot + 1),
1261 btrfs_node_key_ptr_offset(slot),
1262 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1264 btrfs_set_node_key(lower, key, slot);
1265 btrfs_set_node_blockptr(lower, slot, bytenr);
1266 btrfs_set_header_nritems(lower, nritems + 1);
1267 btrfs_mark_buffer_dirty(lower);
1272 * split the node at the specified level in path in two.
1273 * The path is corrected to point to the appropriate node after the split
1275 * Before splitting this tries to make some room in the node by pushing
1276 * left and right, if either one works, it returns right away.
1278 * returns 0 on success and < 0 on failure
1280 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1281 *root, struct btrfs_path *path, int level)
1283 struct extent_buffer *c;
1284 struct extent_buffer *split;
1285 struct btrfs_disk_key disk_key;
1291 c = path->nodes[level];
1292 if (c == root->node) {
1293 /* trying to split the root, lets make a new one */
1294 ret = insert_new_root(trans, root, path, level + 1);
1298 ret = push_nodes_for_insert(trans, root, path, level);
1299 c = path->nodes[level];
1300 if (!ret && btrfs_header_nritems(c) <
1301 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1307 c_nritems = btrfs_header_nritems(c);
1308 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1311 return PTR_ERR(split);
1313 btrfs_set_header_flags(split, btrfs_header_flags(c));
1314 btrfs_set_header_level(split, btrfs_header_level(c));
1315 btrfs_set_header_bytenr(split, split->start);
1316 btrfs_set_header_generation(split, trans->transid);
1317 btrfs_set_header_owner(split, root->root_key.objectid);
1318 write_extent_buffer(split, root->fs_info->fsid,
1319 (unsigned long)btrfs_header_fsid(split),
1322 mid = (c_nritems + 1) / 2;
1324 copy_extent_buffer(split, c,
1325 btrfs_node_key_ptr_offset(0),
1326 btrfs_node_key_ptr_offset(mid),
1327 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1328 btrfs_set_header_nritems(split, c_nritems - mid);
1329 btrfs_set_header_nritems(c, mid);
1332 btrfs_mark_buffer_dirty(c);
1333 btrfs_mark_buffer_dirty(split);
1335 btrfs_node_key(split, &disk_key, 0);
1336 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1337 path->slots[level + 1] + 1,
1342 if (path->slots[level] >= mid) {
1343 path->slots[level] -= mid;
1344 free_extent_buffer(c);
1345 path->nodes[level] = split;
1346 path->slots[level + 1] += 1;
1348 free_extent_buffer(split);
1354 * how many bytes are required to store the items in a leaf. start
1355 * and nr indicate which items in the leaf to check. This totals up the
1356 * space used both by the item structs and the item data
1358 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1361 int nritems = btrfs_header_nritems(l);
1362 int end = min(nritems, start + nr) - 1;
1366 data_len = btrfs_item_end_nr(l, start);
1367 data_len = data_len - btrfs_item_offset_nr(l, end);
1368 data_len += sizeof(struct btrfs_item) * nr;
1369 WARN_ON(data_len < 0);
1374 * The space between the end of the leaf items and
1375 * the start of the leaf data. IOW, how much room
1376 * the leaf has left for both items and data
1378 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1380 int nritems = btrfs_header_nritems(leaf);
1382 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1384 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1385 ret, BTRFS_LEAF_DATA_SIZE(root),
1386 leaf_space_used(leaf, 0, nritems), nritems);
1392 * push some data in the path leaf to the right, trying to free up at
1393 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1395 * returns 1 if the push failed because the other node didn't have enough
1396 * room, 0 if everything worked out and < 0 if there were major errors.
1398 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1399 *root, struct btrfs_path *path, int data_size)
1401 struct extent_buffer *left = path->nodes[0];
1402 struct extent_buffer *right;
1403 struct extent_buffer *upper;
1404 struct btrfs_disk_key disk_key;
1410 struct btrfs_item *item;
1417 slot = path->slots[1];
1418 if (!path->nodes[1]) {
1421 upper = path->nodes[1];
1422 if (slot >= btrfs_header_nritems(upper) - 1)
1425 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1427 free_space = btrfs_leaf_free_space(root, right);
1428 if (free_space < data_size + sizeof(struct btrfs_item)) {
1429 free_extent_buffer(right);
1433 /* cow and double check */
1434 ret = btrfs_cow_block(trans, root, right, upper,
1437 free_extent_buffer(right);
1440 free_space = btrfs_leaf_free_space(root, right);
1441 if (free_space < data_size + sizeof(struct btrfs_item)) {
1442 free_extent_buffer(right);
1446 left_nritems = btrfs_header_nritems(left);
1447 if (left_nritems == 0) {
1448 free_extent_buffer(right);
1452 for (i = left_nritems - 1; i >= 1; i--) {
1453 item = btrfs_item_nr(left, i);
1455 if (path->slots[0] == i)
1456 push_space += data_size + sizeof(*item);
1458 if (!left->map_token) {
1459 map_extent_buffer(left, (unsigned long)item,
1460 sizeof(struct btrfs_item),
1461 &left->map_token, &left->kaddr,
1462 &left->map_start, &left->map_len,
1466 this_item_size = btrfs_item_size(left, item);
1467 if (this_item_size + sizeof(*item) + push_space > free_space)
1470 push_space += this_item_size + sizeof(*item);
1472 if (left->map_token) {
1473 unmap_extent_buffer(left, left->map_token, KM_USER1);
1474 left->map_token = NULL;
1477 if (push_items == 0) {
1478 free_extent_buffer(right);
1482 if (push_items == left_nritems)
1485 /* push left to right */
1486 right_nritems = btrfs_header_nritems(right);
1487 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1488 push_space -= leaf_data_end(root, left);
1490 /* make room in the right data area */
1491 data_end = leaf_data_end(root, right);
1492 memmove_extent_buffer(right,
1493 btrfs_leaf_data(right) + data_end - push_space,
1494 btrfs_leaf_data(right) + data_end,
1495 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1497 /* copy from the left data area */
1498 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1499 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1500 btrfs_leaf_data(left) + leaf_data_end(root, left),
1503 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1504 btrfs_item_nr_offset(0),
1505 right_nritems * sizeof(struct btrfs_item));
1507 /* copy the items from left to right */
1508 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1509 btrfs_item_nr_offset(left_nritems - push_items),
1510 push_items * sizeof(struct btrfs_item));
1512 /* update the item pointers */
1513 right_nritems += push_items;
1514 btrfs_set_header_nritems(right, right_nritems);
1515 push_space = BTRFS_LEAF_DATA_SIZE(root);
1517 for (i = 0; i < right_nritems; i++) {
1518 item = btrfs_item_nr(right, i);
1519 if (!right->map_token) {
1520 map_extent_buffer(right, (unsigned long)item,
1521 sizeof(struct btrfs_item),
1522 &right->map_token, &right->kaddr,
1523 &right->map_start, &right->map_len,
1526 push_space -= btrfs_item_size(right, item);
1527 btrfs_set_item_offset(right, item, push_space);
1530 if (right->map_token) {
1531 unmap_extent_buffer(right, right->map_token, KM_USER1);
1532 right->map_token = NULL;
1534 left_nritems -= push_items;
1535 btrfs_set_header_nritems(left, left_nritems);
1537 btrfs_mark_buffer_dirty(left);
1538 btrfs_mark_buffer_dirty(right);
1540 btrfs_item_key(right, &disk_key, 0);
1541 btrfs_set_node_key(upper, &disk_key, slot + 1);
1542 btrfs_mark_buffer_dirty(upper);
1544 /* then fixup the leaf pointer in the path */
1545 if (path->slots[0] >= left_nritems) {
1546 path->slots[0] -= left_nritems;
1547 free_extent_buffer(path->nodes[0]);
1548 path->nodes[0] = right;
1549 path->slots[1] += 1;
1551 free_extent_buffer(right);
1556 * push some data in the path leaf to the left, trying to free up at
1557 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1559 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1560 *root, struct btrfs_path *path, int data_size)
1562 struct btrfs_disk_key disk_key;
1563 struct extent_buffer *right = path->nodes[0];
1564 struct extent_buffer *left;
1570 struct btrfs_item *item;
1571 u32 old_left_nritems;
1576 u32 old_left_item_size;
1578 slot = path->slots[1];
1581 if (!path->nodes[1])
1584 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1585 slot - 1), root->leafsize);
1586 free_space = btrfs_leaf_free_space(root, left);
1587 if (free_space < data_size + sizeof(struct btrfs_item)) {
1588 free_extent_buffer(left);
1592 /* cow and double check */
1593 ret = btrfs_cow_block(trans, root, left,
1594 path->nodes[1], slot - 1, &left);
1596 /* we hit -ENOSPC, but it isn't fatal here */
1597 free_extent_buffer(left);
1600 free_space = btrfs_leaf_free_space(root, left);
1601 if (free_space < data_size + sizeof(struct btrfs_item)) {
1602 free_extent_buffer(left);
1606 right_nritems = btrfs_header_nritems(right);
1607 if (right_nritems == 0) {
1608 free_extent_buffer(left);
1612 for (i = 0; i < right_nritems - 1; i++) {
1613 item = btrfs_item_nr(right, i);
1614 if (!right->map_token) {
1615 map_extent_buffer(right, (unsigned long)item,
1616 sizeof(struct btrfs_item),
1617 &right->map_token, &right->kaddr,
1618 &right->map_start, &right->map_len,
1622 if (path->slots[0] == i)
1623 push_space += data_size + sizeof(*item);
1625 this_item_size = btrfs_item_size(right, item);
1626 if (this_item_size + sizeof(*item) + push_space > free_space)
1630 push_space += this_item_size + sizeof(*item);
1633 if (right->map_token) {
1634 unmap_extent_buffer(right, right->map_token, KM_USER1);
1635 right->map_token = NULL;
1638 if (push_items == 0) {
1639 free_extent_buffer(left);
1642 if (push_items == btrfs_header_nritems(right))
1645 /* push data from right to left */
1646 copy_extent_buffer(left, right,
1647 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1648 btrfs_item_nr_offset(0),
1649 push_items * sizeof(struct btrfs_item));
1651 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1652 btrfs_item_offset_nr(right, push_items -1);
1654 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1655 leaf_data_end(root, left) - push_space,
1656 btrfs_leaf_data(right) +
1657 btrfs_item_offset_nr(right, push_items - 1),
1659 old_left_nritems = btrfs_header_nritems(left);
1660 BUG_ON(old_left_nritems < 0);
1662 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1663 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1666 item = btrfs_item_nr(left, i);
1667 if (!left->map_token) {
1668 map_extent_buffer(left, (unsigned long)item,
1669 sizeof(struct btrfs_item),
1670 &left->map_token, &left->kaddr,
1671 &left->map_start, &left->map_len,
1675 ioff = btrfs_item_offset(left, item);
1676 btrfs_set_item_offset(left, item,
1677 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1679 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1680 if (left->map_token) {
1681 unmap_extent_buffer(left, left->map_token, KM_USER1);
1682 left->map_token = NULL;
1685 /* fixup right node */
1686 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1687 leaf_data_end(root, right);
1688 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1689 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1690 btrfs_leaf_data(right) +
1691 leaf_data_end(root, right), push_space);
1693 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1694 btrfs_item_nr_offset(push_items),
1695 (btrfs_header_nritems(right) - push_items) *
1696 sizeof(struct btrfs_item));
1698 right_nritems = btrfs_header_nritems(right) - push_items;
1699 btrfs_set_header_nritems(right, right_nritems);
1700 push_space = BTRFS_LEAF_DATA_SIZE(root);
1702 for (i = 0; i < right_nritems; i++) {
1703 item = btrfs_item_nr(right, i);
1705 if (!right->map_token) {
1706 map_extent_buffer(right, (unsigned long)item,
1707 sizeof(struct btrfs_item),
1708 &right->map_token, &right->kaddr,
1709 &right->map_start, &right->map_len,
1713 push_space = push_space - btrfs_item_size(right, item);
1714 btrfs_set_item_offset(right, item, push_space);
1716 if (right->map_token) {
1717 unmap_extent_buffer(right, right->map_token, KM_USER1);
1718 right->map_token = NULL;
1721 btrfs_mark_buffer_dirty(left);
1722 btrfs_mark_buffer_dirty(right);
1724 btrfs_item_key(right, &disk_key, 0);
1725 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1729 /* then fixup the leaf pointer in the path */
1730 if (path->slots[0] < push_items) {
1731 path->slots[0] += old_left_nritems;
1732 free_extent_buffer(path->nodes[0]);
1733 path->nodes[0] = left;
1734 path->slots[1] -= 1;
1736 free_extent_buffer(left);
1737 path->slots[0] -= push_items;
1739 BUG_ON(path->slots[0] < 0);
1744 * split the path's leaf in two, making sure there is at least data_size
1745 * available for the resulting leaf level of the path.
1747 * returns 0 if all went well and < 0 on failure.
1749 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1750 *root, struct btrfs_key *ins_key,
1751 struct btrfs_path *path, int data_size)
1753 struct extent_buffer *l;
1757 struct extent_buffer *right;
1758 int space_needed = data_size + sizeof(struct btrfs_item);
1764 int double_split = 0;
1765 struct btrfs_disk_key disk_key;
1767 /* first try to make some room by pushing left and right */
1768 wret = push_leaf_left(trans, root, path, data_size);
1773 wret = push_leaf_right(trans, root, path, data_size);
1779 /* did the pushes work? */
1780 if (btrfs_leaf_free_space(root, l) >=
1781 sizeof(struct btrfs_item) + data_size) {
1785 if (!path->nodes[1]) {
1786 ret = insert_new_root(trans, root, path, 1);
1790 slot = path->slots[0];
1791 nritems = btrfs_header_nritems(l);
1792 mid = (nritems + 1)/ 2;
1794 right = btrfs_alloc_free_block(trans, root, root->leafsize,
1797 return PTR_ERR(right);
1799 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1800 btrfs_set_header_bytenr(right, right->start);
1801 btrfs_set_header_generation(right, trans->transid);
1802 btrfs_set_header_owner(right, root->root_key.objectid);
1803 btrfs_set_header_level(right, 0);
1804 write_extent_buffer(right, root->fs_info->fsid,
1805 (unsigned long)btrfs_header_fsid(right),
1810 leaf_space_used(l, mid, nritems - mid) + space_needed >
1811 BTRFS_LEAF_DATA_SIZE(root)) {
1812 if (slot >= nritems) {
1813 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1814 btrfs_set_header_nritems(right, 0);
1815 wret = insert_ptr(trans, root, path,
1816 &disk_key, right->start,
1817 path->slots[1] + 1, 1);
1820 free_extent_buffer(path->nodes[0]);
1821 path->nodes[0] = right;
1823 path->slots[1] += 1;
1827 if (mid != nritems &&
1828 leaf_space_used(l, mid, nritems - mid) +
1829 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
1834 if (leaf_space_used(l, 0, mid + 1) + space_needed >
1835 BTRFS_LEAF_DATA_SIZE(root)) {
1837 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1838 btrfs_set_header_nritems(right, 0);
1839 wret = insert_ptr(trans, root, path,
1845 free_extent_buffer(path->nodes[0]);
1846 path->nodes[0] = right;
1848 if (path->slots[1] == 0) {
1849 wret = fixup_low_keys(trans, root,
1850 path, &disk_key, 1);
1860 nritems = nritems - mid;
1861 btrfs_set_header_nritems(right, nritems);
1862 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1864 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1865 btrfs_item_nr_offset(mid),
1866 nritems * sizeof(struct btrfs_item));
1868 copy_extent_buffer(right, l,
1869 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1870 data_copy_size, btrfs_leaf_data(l) +
1871 leaf_data_end(root, l), data_copy_size);
1873 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
1874 btrfs_item_end_nr(l, mid);
1876 for (i = 0; i < nritems; i++) {
1877 struct btrfs_item *item = btrfs_item_nr(right, i);
1880 if (!right->map_token) {
1881 map_extent_buffer(right, (unsigned long)item,
1882 sizeof(struct btrfs_item),
1883 &right->map_token, &right->kaddr,
1884 &right->map_start, &right->map_len,
1888 ioff = btrfs_item_offset(right, item);
1889 btrfs_set_item_offset(right, item, ioff + rt_data_off);
1892 if (right->map_token) {
1893 unmap_extent_buffer(right, right->map_token, KM_USER1);
1894 right->map_token = NULL;
1897 btrfs_set_header_nritems(l, mid);
1899 btrfs_item_key(right, &disk_key, 0);
1900 wret = insert_ptr(trans, root, path, &disk_key, right->start,
1901 path->slots[1] + 1, 1);
1905 btrfs_mark_buffer_dirty(right);
1906 btrfs_mark_buffer_dirty(l);
1907 BUG_ON(path->slots[0] != slot);
1910 free_extent_buffer(path->nodes[0]);
1911 path->nodes[0] = right;
1912 path->slots[0] -= mid;
1913 path->slots[1] += 1;
1915 free_extent_buffer(right);
1917 BUG_ON(path->slots[0] < 0);
1919 if (!double_split) {
1923 right = btrfs_alloc_free_block(trans, root, root->leafsize,
1926 return PTR_ERR(right);
1928 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1929 btrfs_set_header_bytenr(right, right->start);
1930 btrfs_set_header_generation(right, trans->transid);
1931 btrfs_set_header_owner(right, root->root_key.objectid);
1932 btrfs_set_header_level(right, 0);
1933 write_extent_buffer(right, root->fs_info->fsid,
1934 (unsigned long)btrfs_header_fsid(right),
1937 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1938 btrfs_set_header_nritems(right, 0);
1939 wret = insert_ptr(trans, root, path,
1940 &disk_key, right->start,
1944 if (path->slots[1] == 0) {
1945 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1949 free_extent_buffer(path->nodes[0]);
1950 path->nodes[0] = right;
1955 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
1956 struct btrfs_root *root,
1957 struct btrfs_path *path,
1963 struct extent_buffer *leaf;
1964 struct btrfs_item *item;
1966 unsigned int data_end;
1967 unsigned int old_data_start;
1968 unsigned int old_size;
1969 unsigned int size_diff;
1972 slot_orig = path->slots[0];
1973 leaf = path->nodes[0];
1975 nritems = btrfs_header_nritems(leaf);
1976 data_end = leaf_data_end(root, leaf);
1978 slot = path->slots[0];
1979 old_data_start = btrfs_item_offset_nr(leaf, slot);
1980 old_size = btrfs_item_size_nr(leaf, slot);
1981 BUG_ON(old_size <= new_size);
1982 size_diff = old_size - new_size;
1985 BUG_ON(slot >= nritems);
1988 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1990 /* first correct the data pointers */
1991 for (i = slot; i < nritems; i++) {
1993 item = btrfs_item_nr(leaf, i);
1995 if (!leaf->map_token) {
1996 map_extent_buffer(leaf, (unsigned long)item,
1997 sizeof(struct btrfs_item),
1998 &leaf->map_token, &leaf->kaddr,
1999 &leaf->map_start, &leaf->map_len,
2003 ioff = btrfs_item_offset(leaf, item);
2004 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2007 if (leaf->map_token) {
2008 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2009 leaf->map_token = NULL;
2012 /* shift the data */
2013 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2014 data_end + size_diff, btrfs_leaf_data(leaf) +
2015 data_end, old_data_start + new_size - data_end);
2017 item = btrfs_item_nr(leaf, slot);
2018 btrfs_set_item_size(leaf, item, new_size);
2019 btrfs_mark_buffer_dirty(leaf);
2022 if (btrfs_leaf_free_space(root, leaf) < 0) {
2023 btrfs_print_leaf(root, leaf);
2029 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2030 struct btrfs_root *root, struct btrfs_path *path,
2036 struct extent_buffer *leaf;
2037 struct btrfs_item *item;
2039 unsigned int data_end;
2040 unsigned int old_data;
2041 unsigned int old_size;
2044 slot_orig = path->slots[0];
2045 leaf = path->nodes[0];
2047 nritems = btrfs_header_nritems(leaf);
2048 data_end = leaf_data_end(root, leaf);
2050 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2051 btrfs_print_leaf(root, leaf);
2054 slot = path->slots[0];
2055 old_data = btrfs_item_end_nr(leaf, slot);
2058 if (slot >= nritems) {
2059 btrfs_print_leaf(root, leaf);
2060 printk("slot %d too large, nritems %d\n", slot, nritems);
2065 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2067 /* first correct the data pointers */
2068 for (i = slot; i < nritems; i++) {
2070 item = btrfs_item_nr(leaf, i);
2072 if (!leaf->map_token) {
2073 map_extent_buffer(leaf, (unsigned long)item,
2074 sizeof(struct btrfs_item),
2075 &leaf->map_token, &leaf->kaddr,
2076 &leaf->map_start, &leaf->map_len,
2079 ioff = btrfs_item_offset(leaf, item);
2080 btrfs_set_item_offset(leaf, item, ioff - data_size);
2083 if (leaf->map_token) {
2084 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2085 leaf->map_token = NULL;
2088 /* shift the data */
2089 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2090 data_end - data_size, btrfs_leaf_data(leaf) +
2091 data_end, old_data - data_end);
2093 data_end = old_data;
2094 old_size = btrfs_item_size_nr(leaf, slot);
2095 item = btrfs_item_nr(leaf, slot);
2096 btrfs_set_item_size(leaf, item, old_size + data_size);
2097 btrfs_mark_buffer_dirty(leaf);
2100 if (btrfs_leaf_free_space(root, leaf) < 0) {
2101 btrfs_print_leaf(root, leaf);
2108 * Given a key and some data, insert an item into the tree.
2109 * This does all the path init required, making room in the tree if needed.
2111 int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
2112 struct btrfs_root *root,
2113 struct btrfs_path *path,
2114 struct btrfs_key *cpu_key, u32 data_size)
2116 struct extent_buffer *leaf;
2117 struct btrfs_item *item;
2122 unsigned int data_end;
2123 struct btrfs_disk_key disk_key;
2125 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2127 /* create a root if there isn't one */
2131 ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
2138 slot_orig = path->slots[0];
2139 leaf = path->nodes[0];
2141 nritems = btrfs_header_nritems(leaf);
2142 data_end = leaf_data_end(root, leaf);
2144 if (btrfs_leaf_free_space(root, leaf) <
2145 sizeof(struct btrfs_item) + data_size) {
2146 btrfs_print_leaf(root, leaf);
2147 printk("not enough freespace need %u have %d\n",
2148 data_size, btrfs_leaf_free_space(root, leaf));
2152 slot = path->slots[0];
2155 if (slot != nritems) {
2157 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2159 if (old_data < data_end) {
2160 btrfs_print_leaf(root, leaf);
2161 printk("slot %d old_data %d data_end %d\n",
2162 slot, old_data, data_end);
2166 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2168 /* first correct the data pointers */
2169 WARN_ON(leaf->map_token);
2170 for (i = slot; i < nritems; i++) {
2173 item = btrfs_item_nr(leaf, i);
2174 if (!leaf->map_token) {
2175 map_extent_buffer(leaf, (unsigned long)item,
2176 sizeof(struct btrfs_item),
2177 &leaf->map_token, &leaf->kaddr,
2178 &leaf->map_start, &leaf->map_len,
2182 ioff = btrfs_item_offset(leaf, item);
2183 btrfs_set_item_offset(leaf, item, ioff - data_size);
2185 if (leaf->map_token) {
2186 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2187 leaf->map_token = NULL;
2190 /* shift the items */
2191 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2192 btrfs_item_nr_offset(slot),
2193 (nritems - slot) * sizeof(struct btrfs_item));
2195 /* shift the data */
2196 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2197 data_end - data_size, btrfs_leaf_data(leaf) +
2198 data_end, old_data - data_end);
2199 data_end = old_data;
2202 /* setup the item for the new data */
2203 btrfs_set_item_key(leaf, &disk_key, slot);
2204 item = btrfs_item_nr(leaf, slot);
2205 btrfs_set_item_offset(leaf, item, data_end - data_size);
2206 btrfs_set_item_size(leaf, item, data_size);
2207 btrfs_set_header_nritems(leaf, nritems + 1);
2208 btrfs_mark_buffer_dirty(leaf);
2212 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2214 if (btrfs_leaf_free_space(root, leaf) < 0) {
2215 btrfs_print_leaf(root, leaf);
2223 * Given a key and some data, insert an item into the tree.
2224 * This does all the path init required, making room in the tree if needed.
2226 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2227 *root, struct btrfs_key *cpu_key, void *data, u32
2231 struct btrfs_path *path;
2232 struct extent_buffer *leaf;
2235 path = btrfs_alloc_path();
2237 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2239 leaf = path->nodes[0];
2240 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2241 write_extent_buffer(leaf, data, ptr, data_size);
2242 btrfs_mark_buffer_dirty(leaf);
2244 btrfs_free_path(path);
2249 * delete the pointer from a given node.
2251 * If the delete empties a node, the node is removed from the tree,
2252 * continuing all the way the root if required. The root is converted into
2253 * a leaf if all the nodes are emptied.
2255 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2256 struct btrfs_path *path, int level, int slot)
2258 struct extent_buffer *parent = path->nodes[level];
2263 nritems = btrfs_header_nritems(parent);
2264 if (slot != nritems -1) {
2265 memmove_extent_buffer(parent,
2266 btrfs_node_key_ptr_offset(slot),
2267 btrfs_node_key_ptr_offset(slot + 1),
2268 sizeof(struct btrfs_key_ptr) *
2269 (nritems - slot - 1));
2272 btrfs_set_header_nritems(parent, nritems);
2273 if (nritems == 0 && parent == root->node) {
2274 BUG_ON(btrfs_header_level(root->node) != 1);
2275 /* just turn the root into a leaf and break */
2276 btrfs_set_header_level(root->node, 0);
2277 } else if (slot == 0) {
2278 struct btrfs_disk_key disk_key;
2280 btrfs_node_key(parent, &disk_key, 0);
2281 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2285 btrfs_mark_buffer_dirty(parent);
2290 * delete the item at the leaf level in path. If that empties
2291 * the leaf, remove it from the tree
2293 int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2294 struct btrfs_path *path)
2297 struct extent_buffer *leaf;
2298 struct btrfs_item *item;
2305 leaf = path->nodes[0];
2306 slot = path->slots[0];
2307 doff = btrfs_item_offset_nr(leaf, slot);
2308 dsize = btrfs_item_size_nr(leaf, slot);
2309 nritems = btrfs_header_nritems(leaf);
2311 if (slot != nritems - 1) {
2313 int data_end = leaf_data_end(root, leaf);
2315 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2317 btrfs_leaf_data(leaf) + data_end,
2320 for (i = slot + 1; i < nritems; i++) {
2323 item = btrfs_item_nr(leaf, i);
2324 if (!leaf->map_token) {
2325 map_extent_buffer(leaf, (unsigned long)item,
2326 sizeof(struct btrfs_item),
2327 &leaf->map_token, &leaf->kaddr,
2328 &leaf->map_start, &leaf->map_len,
2331 ioff = btrfs_item_offset(leaf, item);
2332 btrfs_set_item_offset(leaf, item, ioff + dsize);
2335 if (leaf->map_token) {
2336 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2337 leaf->map_token = NULL;
2340 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2341 btrfs_item_nr_offset(slot + 1),
2342 sizeof(struct btrfs_item) *
2343 (nritems - slot - 1));
2345 btrfs_set_header_nritems(leaf, nritems - 1);
2348 /* delete the leaf if we've emptied it */
2350 if (leaf == root->node) {
2351 btrfs_set_header_level(leaf, 0);
2353 clean_tree_block(trans, root, leaf);
2354 wait_on_tree_block_writeback(root, leaf);
2355 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2358 wret = btrfs_free_extent(trans, root,
2359 leaf->start, leaf->len, 1);
2364 int used = leaf_space_used(leaf, 0, nritems);
2366 struct btrfs_disk_key disk_key;
2368 btrfs_item_key(leaf, &disk_key, 0);
2369 wret = fixup_low_keys(trans, root, path,
2375 /* delete the leaf if it is mostly empty */
2376 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
2377 /* push_leaf_left fixes the path.
2378 * make sure the path still points to our leaf
2379 * for possible call to del_ptr below
2381 slot = path->slots[1];
2382 extent_buffer_get(leaf);
2384 wret = push_leaf_left(trans, root, path, 1);
2385 if (wret < 0 && wret != -ENOSPC)
2388 if (path->nodes[0] == leaf &&
2389 btrfs_header_nritems(leaf)) {
2390 wret = push_leaf_right(trans, root, path, 1);
2391 if (wret < 0 && wret != -ENOSPC)
2395 if (btrfs_header_nritems(leaf) == 0) {
2396 u64 bytenr = leaf->start;
2397 u32 blocksize = leaf->len;
2399 clean_tree_block(trans, root, leaf);
2400 wait_on_tree_block_writeback(root, leaf);
2402 wret = del_ptr(trans, root, path, 1, slot);
2406 free_extent_buffer(leaf);
2407 wret = btrfs_free_extent(trans, root, bytenr,
2412 btrfs_mark_buffer_dirty(leaf);
2413 free_extent_buffer(leaf);
2416 btrfs_mark_buffer_dirty(leaf);
2423 * walk up the tree as far as required to find the next leaf.
2424 * returns 0 if it found something or 1 if there are no greater leaves.
2425 * returns < 0 on io errors.
2427 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2432 struct extent_buffer *c;
2433 struct extent_buffer *next = NULL;
2435 while(level < BTRFS_MAX_LEVEL) {
2436 if (!path->nodes[level])
2439 slot = path->slots[level] + 1;
2440 c = path->nodes[level];
2441 if (slot >= btrfs_header_nritems(c)) {
2446 bytenr = btrfs_node_blockptr(c, slot);
2448 free_extent_buffer(next);
2451 reada_for_search(root, path, level, slot);
2453 next = read_tree_block(root, bytenr,
2454 btrfs_level_size(root, level -1));
2457 path->slots[level] = slot;
2460 c = path->nodes[level];
2461 free_extent_buffer(c);
2462 path->nodes[level] = next;
2463 path->slots[level] = 0;
2467 reada_for_search(root, path, level, 0);
2468 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2469 btrfs_level_size(root, level - 1));