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.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size, int extend);
30 static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src);
33 static int balance_node_right(struct btrfs_trans_handle *trans,
34 struct btrfs_root *root,
35 struct extent_buffer *dst_buf,
36 struct extent_buffer *src_buf);
37 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
40 inline void btrfs_init_path(struct btrfs_path *p)
42 memset(p, 0, sizeof(*p));
45 struct btrfs_path *btrfs_alloc_path(void)
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
50 btrfs_init_path(path);
56 void btrfs_free_path(struct btrfs_path *p)
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
62 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
68 free_extent_buffer(p->nodes[i]);
70 memset(p, 0, sizeof(*p));
73 static int __btrfs_cow_block(struct btrfs_trans_handle *trans,
74 struct btrfs_root *root,
75 struct extent_buffer *buf,
76 struct extent_buffer *parent, int parent_slot,
77 struct extent_buffer **cow_ret,
78 u64 search_start, u64 empty_size)
80 struct extent_buffer *cow;
82 int different_trans = 0;
84 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
86 cow = btrfs_alloc_free_block(trans, root, buf->len,
87 search_start, empty_size);
91 copy_extent_buffer(cow, buf, 0, 0, cow->len);
92 btrfs_set_header_bytenr(cow, cow->start);
93 btrfs_set_header_generation(cow, trans->transid);
94 btrfs_set_header_owner(cow, root->root_key.objectid);
96 WARN_ON(btrfs_header_generation(buf) > trans->transid);
97 if (btrfs_header_generation(buf) != trans->transid) {
99 ret = btrfs_inc_ref(trans, root, buf);
103 clean_tree_block(trans, root, buf);
106 if (buf == root->node) {
108 extent_buffer_get(cow);
109 if (buf != root->commit_root) {
110 btrfs_free_extent(trans, root, buf->start,
113 free_extent_buffer(buf);
115 btrfs_set_node_blockptr(parent, parent_slot,
117 btrfs_mark_buffer_dirty(parent);
118 WARN_ON(btrfs_header_generation(parent) != trans->transid);
119 btrfs_free_extent(trans, root, buf->start, buf->len, 1);
121 free_extent_buffer(buf);
122 btrfs_mark_buffer_dirty(cow);
127 int btrfs_cow_block(struct btrfs_trans_handle *trans,
128 struct btrfs_root *root, struct extent_buffer *buf,
129 struct extent_buffer *parent, int parent_slot,
130 struct extent_buffer **cow_ret)
134 if (trans->transaction != root->fs_info->running_transaction) {
135 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
136 root->fs_info->running_transaction->transid);
139 if (trans->transid != root->fs_info->generation) {
140 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
141 root->fs_info->generation);
144 if (btrfs_header_generation(buf) == trans->transid) {
149 search_start = buf->start & ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
150 ret = __btrfs_cow_block(trans, root, buf, parent,
151 parent_slot, cow_ret, search_start, 0);
155 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
157 if (blocknr < other && other - (blocknr + blocksize) < 32768)
159 if (blocknr > other && blocknr - (other + blocksize) < 32768)
164 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
165 struct btrfs_root *root, struct extent_buffer *parent,
166 int start_slot, int cache_only, u64 *last_ret,
167 struct btrfs_key *progress)
169 struct extent_buffer *cur;
170 struct extent_buffer *tmp;
172 u64 search_start = *last_ret;
183 parent_level = btrfs_header_level(parent);
184 if (cache_only && parent_level != 1)
187 if (trans->transaction != root->fs_info->running_transaction) {
188 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
189 root->fs_info->running_transaction->transid);
192 if (trans->transid != root->fs_info->generation) {
193 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
194 root->fs_info->generation);
198 parent_nritems = btrfs_header_nritems(parent);
199 blocksize = btrfs_level_size(root, parent_level - 1);
200 end_slot = parent_nritems;
202 if (parent_nritems == 1)
205 for (i = start_slot; i < end_slot; i++) {
208 if (!parent->map_token) {
209 map_extent_buffer(parent,
210 btrfs_node_key_ptr_offset(i),
211 sizeof(struct btrfs_key_ptr),
212 &parent->map_token, &parent->kaddr,
213 &parent->map_start, &parent->map_len,
216 blocknr = btrfs_node_blockptr(parent, i);
218 last_block = blocknr;
221 other = btrfs_node_blockptr(parent, i - 1);
222 close = close_blocks(blocknr, other, blocksize);
224 if (close && i < end_slot - 2) {
225 other = btrfs_node_blockptr(parent, i + 1);
226 close = close_blocks(blocknr, other, blocksize);
229 last_block = blocknr;
232 if (parent->map_token) {
233 unmap_extent_buffer(parent, parent->map_token,
235 parent->map_token = NULL;
238 cur = btrfs_find_tree_block(root, blocknr, blocksize);
240 uptodate = btrfs_buffer_uptodate(cur);
243 if (!cur || !uptodate) {
245 free_extent_buffer(cur);
249 cur = read_tree_block(root, blocknr,
251 } else if (!uptodate) {
252 btrfs_read_buffer(cur);
255 if (search_start == 0)
256 search_start = last_block;
258 err = __btrfs_cow_block(trans, root, cur, parent, i,
261 (end_slot - i) * blocksize));
263 free_extent_buffer(cur);
266 search_start = tmp->start;
267 last_block = tmp->start;
268 *last_ret = search_start;
269 if (parent_level == 1)
270 btrfs_clear_buffer_defrag(tmp);
271 free_extent_buffer(tmp);
273 if (parent->map_token) {
274 unmap_extent_buffer(parent, parent->map_token,
276 parent->map_token = NULL;
282 * The leaf data grows from end-to-front in the node.
283 * this returns the address of the start of the last item,
284 * which is the stop of the leaf data stack
286 static inline unsigned int leaf_data_end(struct btrfs_root *root,
287 struct extent_buffer *leaf)
289 u32 nr = btrfs_header_nritems(leaf);
291 return BTRFS_LEAF_DATA_SIZE(root);
292 return btrfs_item_offset_nr(leaf, nr - 1);
296 * compare two keys in a memcmp fashion
298 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
302 btrfs_disk_key_to_cpu(&k1, disk);
304 if (k1.objectid > k2->objectid)
306 if (k1.objectid < k2->objectid)
308 if (k1.type > k2->type)
310 if (k1.type < k2->type)
312 if (k1.offset > k2->offset)
314 if (k1.offset < k2->offset)
319 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
322 struct extent_buffer *parent = NULL;
323 struct extent_buffer *node = path->nodes[level];
324 struct btrfs_disk_key parent_key;
325 struct btrfs_disk_key node_key;
328 struct btrfs_key cpukey;
329 u32 nritems = btrfs_header_nritems(node);
331 if (path->nodes[level + 1])
332 parent = path->nodes[level + 1];
334 slot = path->slots[level];
335 BUG_ON(nritems == 0);
337 parent_slot = path->slots[level + 1];
338 btrfs_node_key(parent, &parent_key, parent_slot);
339 btrfs_node_key(node, &node_key, 0);
340 BUG_ON(memcmp(&parent_key, &node_key,
341 sizeof(struct btrfs_disk_key)));
342 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
343 btrfs_header_bytenr(node));
345 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
347 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
348 btrfs_node_key(node, &node_key, slot);
349 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
351 if (slot < nritems - 1) {
352 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
353 btrfs_node_key(node, &node_key, slot);
354 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
359 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
362 struct extent_buffer *leaf = path->nodes[level];
363 struct extent_buffer *parent = NULL;
365 struct btrfs_key cpukey;
366 struct btrfs_disk_key parent_key;
367 struct btrfs_disk_key leaf_key;
368 int slot = path->slots[0];
370 u32 nritems = btrfs_header_nritems(leaf);
372 if (path->nodes[level + 1])
373 parent = path->nodes[level + 1];
379 parent_slot = path->slots[level + 1];
380 btrfs_node_key(parent, &parent_key, parent_slot);
381 btrfs_item_key(leaf, &leaf_key, 0);
383 BUG_ON(memcmp(&parent_key, &leaf_key,
384 sizeof(struct btrfs_disk_key)));
385 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
386 btrfs_header_bytenr(leaf));
389 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
390 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
391 btrfs_item_key(leaf, &leaf_key, i);
392 if (comp_keys(&leaf_key, &cpukey) >= 0) {
393 btrfs_print_leaf(root, leaf);
394 printk("slot %d offset bad key\n", i);
397 if (btrfs_item_offset_nr(leaf, i) !=
398 btrfs_item_end_nr(leaf, i + 1)) {
399 btrfs_print_leaf(root, leaf);
400 printk("slot %d offset bad\n", i);
404 if (btrfs_item_offset_nr(leaf, i) +
405 btrfs_item_size_nr(leaf, i) !=
406 BTRFS_LEAF_DATA_SIZE(root)) {
407 btrfs_print_leaf(root, leaf);
408 printk("slot %d first offset bad\n", i);
414 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
415 btrfs_print_leaf(root, leaf);
416 printk("slot %d bad size \n", nritems - 1);
421 if (slot != 0 && slot < nritems - 1) {
422 btrfs_item_key(leaf, &leaf_key, slot);
423 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
424 if (comp_keys(&leaf_key, &cpukey) <= 0) {
425 btrfs_print_leaf(root, leaf);
426 printk("slot %d offset bad key\n", slot);
429 if (btrfs_item_offset_nr(leaf, slot - 1) !=
430 btrfs_item_end_nr(leaf, slot)) {
431 btrfs_print_leaf(root, leaf);
432 printk("slot %d offset bad\n", slot);
436 if (slot < nritems - 1) {
437 btrfs_item_key(leaf, &leaf_key, slot);
438 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
439 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
440 if (btrfs_item_offset_nr(leaf, slot) !=
441 btrfs_item_end_nr(leaf, slot + 1)) {
442 btrfs_print_leaf(root, leaf);
443 printk("slot %d offset bad\n", slot);
447 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
448 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
452 static int check_block(struct btrfs_root *root, struct btrfs_path *path,
457 struct extent_buffer *buf = path->nodes[level];
459 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
460 (unsigned long)btrfs_header_fsid(buf),
462 printk("warning bad block %Lu\n", buf->start);
467 return check_leaf(root, path, level);
468 return check_node(root, path, level);
472 * search for key in the extent_buffer. The items start at offset p,
473 * and they are item_size apart. There are 'max' items in p.
475 * the slot in the array is returned via slot, and it points to
476 * the place where you would insert key if it is not found in
479 * slot may point to max if the key is bigger than all of the keys
481 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
482 int item_size, struct btrfs_key *key,
489 struct btrfs_disk_key *tmp = NULL;
490 struct btrfs_disk_key unaligned;
491 unsigned long offset;
492 char *map_token = NULL;
494 unsigned long map_start = 0;
495 unsigned long map_len = 0;
499 mid = (low + high) / 2;
500 offset = p + mid * item_size;
502 if (!map_token || offset < map_start ||
503 (offset + sizeof(struct btrfs_disk_key)) >
504 map_start + map_len) {
506 unmap_extent_buffer(eb, map_token, KM_USER0);
509 err = map_extent_buffer(eb, offset,
510 sizeof(struct btrfs_disk_key),
512 &map_start, &map_len, KM_USER0);
515 tmp = (struct btrfs_disk_key *)(kaddr + offset -
518 read_extent_buffer(eb, &unaligned,
519 offset, sizeof(unaligned));
524 tmp = (struct btrfs_disk_key *)(kaddr + offset -
527 ret = comp_keys(tmp, key);
536 unmap_extent_buffer(eb, map_token, KM_USER0);
542 unmap_extent_buffer(eb, map_token, KM_USER0);
547 * simple bin_search frontend that does the right thing for
550 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
551 int level, int *slot)
554 return generic_bin_search(eb,
555 offsetof(struct btrfs_leaf, items),
556 sizeof(struct btrfs_item),
557 key, btrfs_header_nritems(eb),
560 return generic_bin_search(eb,
561 offsetof(struct btrfs_node, ptrs),
562 sizeof(struct btrfs_key_ptr),
563 key, btrfs_header_nritems(eb),
569 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
570 struct extent_buffer *parent, int slot)
574 if (slot >= btrfs_header_nritems(parent))
576 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
577 btrfs_level_size(root, btrfs_header_level(parent) - 1));
580 static int balance_level(struct btrfs_trans_handle *trans, struct btrfs_root
581 *root, struct btrfs_path *path, int level)
583 struct extent_buffer *right = NULL;
584 struct extent_buffer *mid;
585 struct extent_buffer *left = NULL;
586 struct extent_buffer *parent = NULL;
590 int orig_slot = path->slots[level];
591 int err_on_enospc = 0;
597 mid = path->nodes[level];
598 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
600 if (level < BTRFS_MAX_LEVEL - 1)
601 parent = path->nodes[level + 1];
602 pslot = path->slots[level + 1];
605 * deal with the case where there is only one pointer in the root
606 * by promoting the node below to a root
609 struct extent_buffer *child;
611 if (btrfs_header_nritems(mid) != 1)
614 /* promote the child to a root */
615 child = read_node_slot(root, mid, 0);
618 path->nodes[level] = NULL;
619 clean_tree_block(trans, root, mid);
620 wait_on_tree_block_writeback(root, mid);
621 /* once for the path */
622 free_extent_buffer(mid);
623 ret = btrfs_free_extent(trans, root, mid->start, mid->len, 1);
624 /* once for the root ptr */
625 free_extent_buffer(mid);
628 if (btrfs_header_nritems(mid) >
629 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
632 if (btrfs_header_nritems(mid) < 2)
635 left = read_node_slot(root, parent, pslot - 1);
637 wret = btrfs_cow_block(trans, root, left,
638 parent, pslot - 1, &left);
644 right = read_node_slot(root, parent, pslot + 1);
646 wret = btrfs_cow_block(trans, root, right,
647 parent, pslot + 1, &right);
654 /* first, try to make some room in the middle buffer */
656 orig_slot += btrfs_header_nritems(left);
657 wret = push_node_left(trans, root, left, mid);
660 if (btrfs_header_nritems(mid) < 2)
665 * then try to empty the right most buffer into the middle
668 wret = push_node_left(trans, root, mid, right);
669 if (wret < 0 && wret != -ENOSPC)
671 if (btrfs_header_nritems(right) == 0) {
672 u64 bytenr = right->start;
673 u32 blocksize = right->len;
675 clean_tree_block(trans, root, right);
676 wait_on_tree_block_writeback(root, right);
677 free_extent_buffer(right);
679 wret = del_ptr(trans, root, path, level + 1, pslot +
683 wret = btrfs_free_extent(trans, root, bytenr,
688 struct btrfs_disk_key right_key;
689 btrfs_node_key(right, &right_key, 0);
690 btrfs_set_node_key(parent, &right_key, pslot + 1);
691 btrfs_mark_buffer_dirty(parent);
694 if (btrfs_header_nritems(mid) == 1) {
696 * we're not allowed to leave a node with one item in the
697 * tree during a delete. A deletion from lower in the tree
698 * could try to delete the only pointer in this node.
699 * So, pull some keys from the left.
700 * There has to be a left pointer at this point because
701 * otherwise we would have pulled some pointers from the
705 wret = balance_node_right(trans, root, mid, left);
712 if (btrfs_header_nritems(mid) == 0) {
713 /* we've managed to empty the middle node, drop it */
714 u64 bytenr = mid->start;
715 u32 blocksize = mid->len;
716 clean_tree_block(trans, root, mid);
717 wait_on_tree_block_writeback(root, mid);
718 free_extent_buffer(mid);
720 wret = del_ptr(trans, root, path, level + 1, pslot);
723 wret = btrfs_free_extent(trans, root, bytenr, blocksize, 1);
727 /* update the parent key to reflect our changes */
728 struct btrfs_disk_key mid_key;
729 btrfs_node_key(mid, &mid_key, 0);
730 btrfs_set_node_key(parent, &mid_key, pslot);
731 btrfs_mark_buffer_dirty(parent);
734 /* update the path */
736 if (btrfs_header_nritems(left) > orig_slot) {
737 extent_buffer_get(left);
738 path->nodes[level] = left;
739 path->slots[level + 1] -= 1;
740 path->slots[level] = orig_slot;
742 free_extent_buffer(mid);
744 orig_slot -= btrfs_header_nritems(left);
745 path->slots[level] = orig_slot;
748 /* double check we haven't messed things up */
749 check_block(root, path, level);
751 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
755 free_extent_buffer(right);
757 free_extent_buffer(left);
761 /* returns zero if the push worked, non-zero otherwise */
762 static int push_nodes_for_insert(struct btrfs_trans_handle *trans,
763 struct btrfs_root *root,
764 struct btrfs_path *path, int level)
766 struct extent_buffer *right = NULL;
767 struct extent_buffer *mid;
768 struct extent_buffer *left = NULL;
769 struct extent_buffer *parent = NULL;
773 int orig_slot = path->slots[level];
779 mid = path->nodes[level];
780 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
782 if (level < BTRFS_MAX_LEVEL - 1)
783 parent = path->nodes[level + 1];
784 pslot = path->slots[level + 1];
789 left = read_node_slot(root, parent, pslot - 1);
791 /* first, try to make some room in the middle buffer */
794 left_nr = btrfs_header_nritems(left);
795 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
798 ret = btrfs_cow_block(trans, root, left, parent,
803 wret = push_node_left(trans, root,
810 struct btrfs_disk_key disk_key;
811 orig_slot += left_nr;
812 btrfs_node_key(mid, &disk_key, 0);
813 btrfs_set_node_key(parent, &disk_key, pslot);
814 btrfs_mark_buffer_dirty(parent);
815 if (btrfs_header_nritems(left) > orig_slot) {
816 path->nodes[level] = left;
817 path->slots[level + 1] -= 1;
818 path->slots[level] = orig_slot;
819 free_extent_buffer(mid);
822 btrfs_header_nritems(left);
823 path->slots[level] = orig_slot;
824 free_extent_buffer(left);
828 free_extent_buffer(left);
830 right= read_node_slot(root, parent, pslot + 1);
833 * then try to empty the right most buffer into the middle
837 right_nr = btrfs_header_nritems(right);
838 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
841 ret = btrfs_cow_block(trans, root, right,
847 wret = balance_node_right(trans, root,
854 struct btrfs_disk_key disk_key;
856 btrfs_node_key(right, &disk_key, 0);
857 btrfs_set_node_key(parent, &disk_key, pslot + 1);
858 btrfs_mark_buffer_dirty(parent);
860 if (btrfs_header_nritems(mid) <= orig_slot) {
861 path->nodes[level] = right;
862 path->slots[level + 1] += 1;
863 path->slots[level] = orig_slot -
864 btrfs_header_nritems(mid);
865 free_extent_buffer(mid);
867 free_extent_buffer(right);
871 free_extent_buffer(right);
877 * readahead one full node of leaves
879 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
882 struct extent_buffer *node;
888 int direction = path->reada;
889 struct extent_buffer *eb;
897 if (!path->nodes[level])
900 node = path->nodes[level];
901 search = btrfs_node_blockptr(node, slot);
902 blocksize = btrfs_level_size(root, level - 1);
903 eb = btrfs_find_tree_block(root, search, blocksize);
905 free_extent_buffer(eb);
909 highest_read = search;
910 lowest_read = search;
912 nritems = btrfs_header_nritems(node);
919 } else if (direction > 0) {
924 search = btrfs_node_blockptr(node, nr);
925 if ((search >= lowest_read && search <= highest_read) ||
926 (search < lowest_read && lowest_read - search <= 32768) ||
927 (search > highest_read && search - highest_read <= 32768)) {
928 readahead_tree_block(root, search, blocksize);
932 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
934 if(nread > (1024 * 1024) || nscan > 128)
937 if (search < lowest_read)
938 lowest_read = search;
939 if (search > highest_read)
940 highest_read = search;
944 * look for key in the tree. path is filled in with nodes along the way
945 * if key is found, we return zero and you can find the item in the leaf
946 * level of the path (level 0)
948 * If the key isn't found, the path points to the slot where it should
949 * be inserted, and 1 is returned. If there are other errors during the
950 * search a negative error number is returned.
952 * if ins_len > 0, nodes and leaves will be split as we walk down the
953 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
956 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
957 *root, struct btrfs_key *key, struct btrfs_path *p, int
960 struct extent_buffer *b;
965 int should_reada = p->reada;
968 lowest_level = p->lowest_level;
969 WARN_ON(lowest_level && ins_len);
970 WARN_ON(p->nodes[0] != NULL);
971 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
974 extent_buffer_get(b);
976 level = btrfs_header_level(b);
979 wret = btrfs_cow_block(trans, root, b,
984 free_extent_buffer(b);
988 BUG_ON(!cow && ins_len);
989 if (level != btrfs_header_level(b))
991 level = btrfs_header_level(b);
993 ret = check_block(root, p, level);
996 ret = bin_search(b, key, level, &slot);
1000 p->slots[level] = slot;
1001 if (ins_len > 0 && btrfs_header_nritems(b) >=
1002 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1003 int sret = split_node(trans, root, p, level);
1007 b = p->nodes[level];
1008 slot = p->slots[level];
1009 } else if (ins_len < 0) {
1010 int sret = balance_level(trans, root, p,
1014 b = p->nodes[level];
1016 btrfs_release_path(NULL, p);
1019 slot = p->slots[level];
1020 BUG_ON(btrfs_header_nritems(b) == 1);
1022 /* this is only true while dropping a snapshot */
1023 if (level == lowest_level)
1025 bytenr = btrfs_node_blockptr(b, slot);
1027 reada_for_search(root, p, level, slot);
1028 b = read_tree_block(root, bytenr,
1029 btrfs_level_size(root, level - 1));
1031 p->slots[level] = slot;
1032 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1033 sizeof(struct btrfs_item) + ins_len) {
1034 int sret = split_leaf(trans, root, key,
1035 p, ins_len, ret == 0);
1047 * adjust the pointers going up the tree, starting at level
1048 * making sure the right key of each node is points to 'key'.
1049 * This is used after shifting pointers to the left, so it stops
1050 * fixing up pointers when a given leaf/node is not in slot 0 of the
1053 * If this fails to write a tree block, it returns -1, but continues
1054 * fixing up the blocks in ram so the tree is consistent.
1056 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1057 struct btrfs_root *root, struct btrfs_path *path,
1058 struct btrfs_disk_key *key, int level)
1062 struct extent_buffer *t;
1064 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1065 int tslot = path->slots[i];
1066 if (!path->nodes[i])
1069 btrfs_set_node_key(t, key, tslot);
1070 btrfs_mark_buffer_dirty(path->nodes[i]);
1078 * try to push data from one node into the next node left in the
1081 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1082 * error, and > 0 if there was no room in the left hand block.
1084 static int push_node_left(struct btrfs_trans_handle *trans, struct btrfs_root
1085 *root, struct extent_buffer *dst,
1086 struct extent_buffer *src)
1093 src_nritems = btrfs_header_nritems(src);
1094 dst_nritems = btrfs_header_nritems(dst);
1095 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1097 if (push_items <= 0) {
1101 if (src_nritems < push_items)
1102 push_items = src_nritems;
1104 copy_extent_buffer(dst, src,
1105 btrfs_node_key_ptr_offset(dst_nritems),
1106 btrfs_node_key_ptr_offset(0),
1107 push_items * sizeof(struct btrfs_key_ptr));
1109 if (push_items < src_nritems) {
1110 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1111 btrfs_node_key_ptr_offset(push_items),
1112 (src_nritems - push_items) *
1113 sizeof(struct btrfs_key_ptr));
1115 btrfs_set_header_nritems(src, src_nritems - push_items);
1116 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1117 btrfs_mark_buffer_dirty(src);
1118 btrfs_mark_buffer_dirty(dst);
1123 * try to push data from one node into the next node right in the
1126 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1127 * error, and > 0 if there was no room in the right hand block.
1129 * this will only push up to 1/2 the contents of the left node over
1131 static int balance_node_right(struct btrfs_trans_handle *trans,
1132 struct btrfs_root *root,
1133 struct extent_buffer *dst,
1134 struct extent_buffer *src)
1142 src_nritems = btrfs_header_nritems(src);
1143 dst_nritems = btrfs_header_nritems(dst);
1144 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1145 if (push_items <= 0)
1148 max_push = src_nritems / 2 + 1;
1149 /* don't try to empty the node */
1150 if (max_push >= src_nritems)
1153 if (max_push < push_items)
1154 push_items = max_push;
1156 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1157 btrfs_node_key_ptr_offset(0),
1159 sizeof(struct btrfs_key_ptr));
1161 copy_extent_buffer(dst, src,
1162 btrfs_node_key_ptr_offset(0),
1163 btrfs_node_key_ptr_offset(src_nritems - push_items),
1164 push_items * sizeof(struct btrfs_key_ptr));
1166 btrfs_set_header_nritems(src, src_nritems - push_items);
1167 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1169 btrfs_mark_buffer_dirty(src);
1170 btrfs_mark_buffer_dirty(dst);
1175 * helper function to insert a new root level in the tree.
1176 * A new node is allocated, and a single item is inserted to
1177 * point to the existing root
1179 * returns zero on success or < 0 on failure.
1181 static int insert_new_root(struct btrfs_trans_handle *trans,
1182 struct btrfs_root *root,
1183 struct btrfs_path *path, int level)
1185 struct extent_buffer *lower;
1186 struct extent_buffer *c;
1187 struct btrfs_disk_key lower_key;
1189 BUG_ON(path->nodes[level]);
1190 BUG_ON(path->nodes[level-1] != root->node);
1192 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1193 root->node->start, 0);
1196 memset_extent_buffer(c, 0, 0, root->nodesize);
1197 btrfs_set_header_nritems(c, 1);
1198 btrfs_set_header_level(c, level);
1199 btrfs_set_header_bytenr(c, c->start);
1200 btrfs_set_header_generation(c, trans->transid);
1201 btrfs_set_header_owner(c, root->root_key.objectid);
1202 lower = path->nodes[level-1];
1204 write_extent_buffer(c, root->fs_info->fsid,
1205 (unsigned long)btrfs_header_fsid(c),
1208 btrfs_item_key(lower, &lower_key, 0);
1210 btrfs_node_key(lower, &lower_key, 0);
1211 btrfs_set_node_key(c, &lower_key, 0);
1212 btrfs_set_node_blockptr(c, 0, lower->start);
1214 btrfs_mark_buffer_dirty(c);
1216 /* the super has an extra ref to root->node */
1217 free_extent_buffer(root->node);
1219 extent_buffer_get(c);
1220 path->nodes[level] = c;
1221 path->slots[level] = 0;
1226 * worker function to insert a single pointer in a node.
1227 * the node should have enough room for the pointer already
1229 * slot and level indicate where you want the key to go, and
1230 * blocknr is the block the key points to.
1232 * returns zero on success and < 0 on any error
1234 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1235 *root, struct btrfs_path *path, struct btrfs_disk_key
1236 *key, u64 bytenr, int slot, int level)
1238 struct extent_buffer *lower;
1241 BUG_ON(!path->nodes[level]);
1242 lower = path->nodes[level];
1243 nritems = btrfs_header_nritems(lower);
1246 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1248 if (slot != nritems) {
1249 memmove_extent_buffer(lower,
1250 btrfs_node_key_ptr_offset(slot + 1),
1251 btrfs_node_key_ptr_offset(slot),
1252 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1254 btrfs_set_node_key(lower, key, slot);
1255 btrfs_set_node_blockptr(lower, slot, bytenr);
1256 btrfs_set_header_nritems(lower, nritems + 1);
1257 btrfs_mark_buffer_dirty(lower);
1262 * split the node at the specified level in path in two.
1263 * The path is corrected to point to the appropriate node after the split
1265 * Before splitting this tries to make some room in the node by pushing
1266 * left and right, if either one works, it returns right away.
1268 * returns 0 on success and < 0 on failure
1270 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1271 *root, struct btrfs_path *path, int level)
1273 struct extent_buffer *c;
1274 struct extent_buffer *split;
1275 struct btrfs_disk_key disk_key;
1281 c = path->nodes[level];
1282 if (c == root->node) {
1283 /* trying to split the root, lets make a new one */
1284 ret = insert_new_root(trans, root, path, level + 1);
1288 ret = push_nodes_for_insert(trans, root, path, level);
1289 c = path->nodes[level];
1290 if (!ret && btrfs_header_nritems(c) <
1291 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1297 c_nritems = btrfs_header_nritems(c);
1298 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1301 return PTR_ERR(split);
1303 btrfs_set_header_flags(split, btrfs_header_flags(c));
1304 btrfs_set_header_level(split, btrfs_header_level(c));
1305 btrfs_set_header_bytenr(split, split->start);
1306 btrfs_set_header_generation(split, trans->transid);
1307 btrfs_set_header_owner(split, root->root_key.objectid);
1308 write_extent_buffer(split, root->fs_info->fsid,
1309 (unsigned long)btrfs_header_fsid(split),
1312 mid = (c_nritems + 1) / 2;
1314 copy_extent_buffer(split, c,
1315 btrfs_node_key_ptr_offset(0),
1316 btrfs_node_key_ptr_offset(mid),
1317 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1318 btrfs_set_header_nritems(split, c_nritems - mid);
1319 btrfs_set_header_nritems(c, mid);
1322 btrfs_mark_buffer_dirty(c);
1323 btrfs_mark_buffer_dirty(split);
1325 btrfs_node_key(split, &disk_key, 0);
1326 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1327 path->slots[level + 1] + 1,
1332 if (path->slots[level] >= mid) {
1333 path->slots[level] -= mid;
1334 free_extent_buffer(c);
1335 path->nodes[level] = split;
1336 path->slots[level + 1] += 1;
1338 free_extent_buffer(split);
1344 * how many bytes are required to store the items in a leaf. start
1345 * and nr indicate which items in the leaf to check. This totals up the
1346 * space used both by the item structs and the item data
1348 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1351 int nritems = btrfs_header_nritems(l);
1352 int end = min(nritems, start + nr) - 1;
1356 data_len = btrfs_item_end_nr(l, start);
1357 data_len = data_len - btrfs_item_offset_nr(l, end);
1358 data_len += sizeof(struct btrfs_item) * nr;
1359 WARN_ON(data_len < 0);
1364 * The space between the end of the leaf items and
1365 * the start of the leaf data. IOW, how much room
1366 * the leaf has left for both items and data
1368 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1370 int nritems = btrfs_header_nritems(leaf);
1372 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1374 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1375 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1376 leaf_space_used(leaf, 0, nritems), nritems);
1382 * push some data in the path leaf to the right, trying to free up at
1383 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1385 * returns 1 if the push failed because the other node didn't have enough
1386 * room, 0 if everything worked out and < 0 if there were major errors.
1388 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1389 *root, struct btrfs_path *path, int data_size)
1391 struct extent_buffer *left = path->nodes[0];
1392 struct extent_buffer *right;
1393 struct extent_buffer *upper;
1394 struct btrfs_disk_key disk_key;
1400 struct btrfs_item *item;
1407 slot = path->slots[1];
1408 if (!path->nodes[1]) {
1411 upper = path->nodes[1];
1412 if (slot >= btrfs_header_nritems(upper) - 1)
1415 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1417 free_space = btrfs_leaf_free_space(root, right);
1418 if (free_space < data_size + sizeof(struct btrfs_item)) {
1419 free_extent_buffer(right);
1423 /* cow and double check */
1424 ret = btrfs_cow_block(trans, root, right, upper,
1427 free_extent_buffer(right);
1430 free_space = btrfs_leaf_free_space(root, right);
1431 if (free_space < data_size + sizeof(struct btrfs_item)) {
1432 free_extent_buffer(right);
1436 left_nritems = btrfs_header_nritems(left);
1437 if (left_nritems == 0) {
1438 free_extent_buffer(right);
1442 for (i = left_nritems - 1; i >= 1; i--) {
1443 item = btrfs_item_nr(left, i);
1445 if (path->slots[0] == i)
1446 push_space += data_size + sizeof(*item);
1448 if (!left->map_token) {
1449 map_extent_buffer(left, (unsigned long)item,
1450 sizeof(struct btrfs_item),
1451 &left->map_token, &left->kaddr,
1452 &left->map_start, &left->map_len,
1456 this_item_size = btrfs_item_size(left, item);
1457 if (this_item_size + sizeof(*item) + push_space > free_space)
1460 push_space += this_item_size + sizeof(*item);
1462 if (left->map_token) {
1463 unmap_extent_buffer(left, left->map_token, KM_USER1);
1464 left->map_token = NULL;
1467 if (push_items == 0) {
1468 free_extent_buffer(right);
1472 if (push_items == left_nritems)
1475 /* push left to right */
1476 right_nritems = btrfs_header_nritems(right);
1477 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1478 push_space -= leaf_data_end(root, left);
1480 /* make room in the right data area */
1481 data_end = leaf_data_end(root, right);
1482 memmove_extent_buffer(right,
1483 btrfs_leaf_data(right) + data_end - push_space,
1484 btrfs_leaf_data(right) + data_end,
1485 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1487 /* copy from the left data area */
1488 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1489 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1490 btrfs_leaf_data(left) + leaf_data_end(root, left),
1493 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1494 btrfs_item_nr_offset(0),
1495 right_nritems * sizeof(struct btrfs_item));
1497 /* copy the items from left to right */
1498 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1499 btrfs_item_nr_offset(left_nritems - push_items),
1500 push_items * sizeof(struct btrfs_item));
1502 /* update the item pointers */
1503 right_nritems += push_items;
1504 btrfs_set_header_nritems(right, right_nritems);
1505 push_space = BTRFS_LEAF_DATA_SIZE(root);
1507 for (i = 0; i < right_nritems; i++) {
1508 item = btrfs_item_nr(right, i);
1509 if (!right->map_token) {
1510 map_extent_buffer(right, (unsigned long)item,
1511 sizeof(struct btrfs_item),
1512 &right->map_token, &right->kaddr,
1513 &right->map_start, &right->map_len,
1516 push_space -= btrfs_item_size(right, item);
1517 btrfs_set_item_offset(right, item, push_space);
1520 if (right->map_token) {
1521 unmap_extent_buffer(right, right->map_token, KM_USER1);
1522 right->map_token = NULL;
1524 left_nritems -= push_items;
1525 btrfs_set_header_nritems(left, left_nritems);
1527 btrfs_mark_buffer_dirty(left);
1528 btrfs_mark_buffer_dirty(right);
1530 btrfs_item_key(right, &disk_key, 0);
1531 btrfs_set_node_key(upper, &disk_key, slot + 1);
1532 btrfs_mark_buffer_dirty(upper);
1534 /* then fixup the leaf pointer in the path */
1535 if (path->slots[0] >= left_nritems) {
1536 path->slots[0] -= left_nritems;
1537 free_extent_buffer(path->nodes[0]);
1538 path->nodes[0] = right;
1539 path->slots[1] += 1;
1541 free_extent_buffer(right);
1546 * push some data in the path leaf to the left, trying to free up at
1547 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1549 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1550 *root, struct btrfs_path *path, int data_size)
1552 struct btrfs_disk_key disk_key;
1553 struct extent_buffer *right = path->nodes[0];
1554 struct extent_buffer *left;
1560 struct btrfs_item *item;
1561 u32 old_left_nritems;
1566 u32 old_left_item_size;
1568 slot = path->slots[1];
1571 if (!path->nodes[1])
1574 right_nritems = btrfs_header_nritems(right);
1575 if (right_nritems == 0) {
1579 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1580 slot - 1), root->leafsize);
1581 free_space = btrfs_leaf_free_space(root, left);
1582 if (free_space < data_size + sizeof(struct btrfs_item)) {
1583 free_extent_buffer(left);
1587 /* cow and double check */
1588 ret = btrfs_cow_block(trans, root, left,
1589 path->nodes[1], slot - 1, &left);
1591 /* we hit -ENOSPC, but it isn't fatal here */
1592 free_extent_buffer(left);
1596 free_space = btrfs_leaf_free_space(root, left);
1597 if (free_space < data_size + sizeof(struct btrfs_item)) {
1598 free_extent_buffer(left);
1602 for (i = 0; i < right_nritems - 1; i++) {
1603 item = btrfs_item_nr(right, i);
1604 if (!right->map_token) {
1605 map_extent_buffer(right, (unsigned long)item,
1606 sizeof(struct btrfs_item),
1607 &right->map_token, &right->kaddr,
1608 &right->map_start, &right->map_len,
1612 if (path->slots[0] == i)
1613 push_space += data_size + sizeof(*item);
1615 this_item_size = btrfs_item_size(right, item);
1616 if (this_item_size + sizeof(*item) + push_space > free_space)
1620 push_space += this_item_size + sizeof(*item);
1623 if (right->map_token) {
1624 unmap_extent_buffer(right, right->map_token, KM_USER1);
1625 right->map_token = NULL;
1628 if (push_items == 0) {
1629 free_extent_buffer(left);
1632 if (push_items == btrfs_header_nritems(right))
1635 /* push data from right to left */
1636 copy_extent_buffer(left, right,
1637 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1638 btrfs_item_nr_offset(0),
1639 push_items * sizeof(struct btrfs_item));
1641 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1642 btrfs_item_offset_nr(right, push_items -1);
1644 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1645 leaf_data_end(root, left) - push_space,
1646 btrfs_leaf_data(right) +
1647 btrfs_item_offset_nr(right, push_items - 1),
1649 old_left_nritems = btrfs_header_nritems(left);
1650 BUG_ON(old_left_nritems < 0);
1652 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1653 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1656 item = btrfs_item_nr(left, i);
1657 if (!left->map_token) {
1658 map_extent_buffer(left, (unsigned long)item,
1659 sizeof(struct btrfs_item),
1660 &left->map_token, &left->kaddr,
1661 &left->map_start, &left->map_len,
1665 ioff = btrfs_item_offset(left, item);
1666 btrfs_set_item_offset(left, item,
1667 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1669 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1670 if (left->map_token) {
1671 unmap_extent_buffer(left, left->map_token, KM_USER1);
1672 left->map_token = NULL;
1675 /* fixup right node */
1676 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1677 leaf_data_end(root, right);
1678 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1679 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1680 btrfs_leaf_data(right) +
1681 leaf_data_end(root, right), push_space);
1683 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1684 btrfs_item_nr_offset(push_items),
1685 (btrfs_header_nritems(right) - push_items) *
1686 sizeof(struct btrfs_item));
1688 right_nritems = btrfs_header_nritems(right) - push_items;
1689 btrfs_set_header_nritems(right, right_nritems);
1690 push_space = BTRFS_LEAF_DATA_SIZE(root);
1692 for (i = 0; i < right_nritems; i++) {
1693 item = btrfs_item_nr(right, i);
1695 if (!right->map_token) {
1696 map_extent_buffer(right, (unsigned long)item,
1697 sizeof(struct btrfs_item),
1698 &right->map_token, &right->kaddr,
1699 &right->map_start, &right->map_len,
1703 push_space = push_space - btrfs_item_size(right, item);
1704 btrfs_set_item_offset(right, item, push_space);
1706 if (right->map_token) {
1707 unmap_extent_buffer(right, right->map_token, KM_USER1);
1708 right->map_token = NULL;
1711 btrfs_mark_buffer_dirty(left);
1712 btrfs_mark_buffer_dirty(right);
1714 btrfs_item_key(right, &disk_key, 0);
1715 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1719 /* then fixup the leaf pointer in the path */
1720 if (path->slots[0] < push_items) {
1721 path->slots[0] += old_left_nritems;
1722 free_extent_buffer(path->nodes[0]);
1723 path->nodes[0] = left;
1724 path->slots[1] -= 1;
1726 free_extent_buffer(left);
1727 path->slots[0] -= push_items;
1729 BUG_ON(path->slots[0] < 0);
1734 * split the path's leaf in two, making sure there is at least data_size
1735 * available for the resulting leaf level of the path.
1737 * returns 0 if all went well and < 0 on failure.
1739 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1740 *root, struct btrfs_key *ins_key,
1741 struct btrfs_path *path, int data_size, int extend)
1743 struct extent_buffer *l;
1747 struct extent_buffer *right;
1748 int space_needed = data_size + sizeof(struct btrfs_item);
1755 int num_doubles = 0;
1756 struct btrfs_disk_key disk_key;
1759 space_needed = data_size;
1761 /* first try to make some room by pushing left and right */
1762 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1763 wret = push_leaf_right(trans, root, path, data_size);
1768 wret = push_leaf_left(trans, root, path, data_size);
1774 /* did the pushes work? */
1775 if (btrfs_leaf_free_space(root, l) >= space_needed)
1779 if (!path->nodes[1]) {
1780 ret = insert_new_root(trans, root, path, 1);
1787 slot = path->slots[0];
1788 nritems = btrfs_header_nritems(l);
1789 mid = (nritems + 1)/ 2;
1791 right = btrfs_alloc_free_block(trans, root, root->leafsize,
1794 return PTR_ERR(right);
1796 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1797 btrfs_set_header_bytenr(right, right->start);
1798 btrfs_set_header_generation(right, trans->transid);
1799 btrfs_set_header_owner(right, root->root_key.objectid);
1800 btrfs_set_header_level(right, 0);
1801 write_extent_buffer(right, root->fs_info->fsid,
1802 (unsigned long)btrfs_header_fsid(right),
1806 leaf_space_used(l, mid, nritems - mid) + space_needed >
1807 BTRFS_LEAF_DATA_SIZE(root)) {
1808 if (slot >= nritems) {
1809 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1810 btrfs_set_header_nritems(right, 0);
1811 wret = insert_ptr(trans, root, path,
1812 &disk_key, right->start,
1813 path->slots[1] + 1, 1);
1816 free_extent_buffer(path->nodes[0]);
1817 path->nodes[0] = right;
1819 path->slots[1] += 1;
1823 if (mid != nritems &&
1824 leaf_space_used(l, mid, nritems - mid) +
1825 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
1830 if (leaf_space_used(l, 0, mid + 1) + space_needed >
1831 BTRFS_LEAF_DATA_SIZE(root)) {
1832 if (!extend && slot == 0) {
1833 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1834 btrfs_set_header_nritems(right, 0);
1835 wret = insert_ptr(trans, root, path,
1841 free_extent_buffer(path->nodes[0]);
1842 path->nodes[0] = right;
1844 if (path->slots[1] == 0) {
1845 wret = fixup_low_keys(trans, root,
1846 path, &disk_key, 1);
1851 } else if (extend && slot == 0) {
1855 if (mid != nritems &&
1856 leaf_space_used(l, mid, nritems - mid) +
1857 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
1863 nritems = nritems - mid;
1864 btrfs_set_header_nritems(right, nritems);
1865 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
1867 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
1868 btrfs_item_nr_offset(mid),
1869 nritems * sizeof(struct btrfs_item));
1871 copy_extent_buffer(right, l,
1872 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
1873 data_copy_size, btrfs_leaf_data(l) +
1874 leaf_data_end(root, l), data_copy_size);
1876 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
1877 btrfs_item_end_nr(l, mid);
1879 for (i = 0; i < nritems; i++) {
1880 struct btrfs_item *item = btrfs_item_nr(right, i);
1883 if (!right->map_token) {
1884 map_extent_buffer(right, (unsigned long)item,
1885 sizeof(struct btrfs_item),
1886 &right->map_token, &right->kaddr,
1887 &right->map_start, &right->map_len,
1891 ioff = btrfs_item_offset(right, item);
1892 btrfs_set_item_offset(right, item, ioff + rt_data_off);
1895 if (right->map_token) {
1896 unmap_extent_buffer(right, right->map_token, KM_USER1);
1897 right->map_token = NULL;
1900 btrfs_set_header_nritems(l, mid);
1902 btrfs_item_key(right, &disk_key, 0);
1903 wret = insert_ptr(trans, root, path, &disk_key, right->start,
1904 path->slots[1] + 1, 1);
1908 btrfs_mark_buffer_dirty(right);
1909 btrfs_mark_buffer_dirty(l);
1910 BUG_ON(path->slots[0] != slot);
1913 free_extent_buffer(path->nodes[0]);
1914 path->nodes[0] = right;
1915 path->slots[0] -= mid;
1916 path->slots[1] += 1;
1918 free_extent_buffer(right);
1920 BUG_ON(path->slots[0] < 0);
1923 BUG_ON(num_doubles != 0);
1930 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
1931 struct btrfs_root *root,
1932 struct btrfs_path *path,
1933 u32 new_size, int from_end)
1938 struct extent_buffer *leaf;
1939 struct btrfs_item *item;
1941 unsigned int data_end;
1942 unsigned int old_data_start;
1943 unsigned int old_size;
1944 unsigned int size_diff;
1947 slot_orig = path->slots[0];
1948 leaf = path->nodes[0];
1949 slot = path->slots[0];
1951 old_size = btrfs_item_size_nr(leaf, slot);
1952 if (old_size == new_size)
1955 nritems = btrfs_header_nritems(leaf);
1956 data_end = leaf_data_end(root, leaf);
1958 old_data_start = btrfs_item_offset_nr(leaf, slot);
1960 size_diff = old_size - new_size;
1963 BUG_ON(slot >= nritems);
1966 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1968 /* first correct the data pointers */
1969 for (i = slot; i < nritems; i++) {
1971 item = btrfs_item_nr(leaf, i);
1973 if (!leaf->map_token) {
1974 map_extent_buffer(leaf, (unsigned long)item,
1975 sizeof(struct btrfs_item),
1976 &leaf->map_token, &leaf->kaddr,
1977 &leaf->map_start, &leaf->map_len,
1981 ioff = btrfs_item_offset(leaf, item);
1982 btrfs_set_item_offset(leaf, item, ioff + size_diff);
1985 if (leaf->map_token) {
1986 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
1987 leaf->map_token = NULL;
1990 /* shift the data */
1992 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
1993 data_end + size_diff, btrfs_leaf_data(leaf) +
1994 data_end, old_data_start + new_size - data_end);
1996 struct btrfs_disk_key disk_key;
1999 btrfs_item_key(leaf, &disk_key, slot);
2001 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2003 struct btrfs_file_extent_item *fi;
2005 fi = btrfs_item_ptr(leaf, slot,
2006 struct btrfs_file_extent_item);
2007 fi = (struct btrfs_file_extent_item *)(
2008 (unsigned long)fi - size_diff);
2010 if (btrfs_file_extent_type(leaf, fi) ==
2011 BTRFS_FILE_EXTENT_INLINE) {
2012 ptr = btrfs_item_ptr_offset(leaf, slot);
2013 memmove_extent_buffer(leaf, ptr,
2015 offsetof(struct btrfs_file_extent_item,
2020 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2021 data_end + size_diff, btrfs_leaf_data(leaf) +
2022 data_end, old_data_start - data_end);
2024 offset = btrfs_disk_key_offset(&disk_key);
2025 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2026 btrfs_set_item_key(leaf, &disk_key, slot);
2028 fixup_low_keys(trans, root, path, &disk_key, 1);
2031 item = btrfs_item_nr(leaf, slot);
2032 btrfs_set_item_size(leaf, item, new_size);
2033 btrfs_mark_buffer_dirty(leaf);
2036 if (btrfs_leaf_free_space(root, leaf) < 0) {
2037 btrfs_print_leaf(root, leaf);
2043 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2044 struct btrfs_root *root, struct btrfs_path *path,
2050 struct extent_buffer *leaf;
2051 struct btrfs_item *item;
2053 unsigned int data_end;
2054 unsigned int old_data;
2055 unsigned int old_size;
2058 slot_orig = path->slots[0];
2059 leaf = path->nodes[0];
2061 nritems = btrfs_header_nritems(leaf);
2062 data_end = leaf_data_end(root, leaf);
2064 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2065 btrfs_print_leaf(root, leaf);
2068 slot = path->slots[0];
2069 old_data = btrfs_item_end_nr(leaf, slot);
2072 if (slot >= nritems) {
2073 btrfs_print_leaf(root, leaf);
2074 printk("slot %d too large, nritems %d\n", slot, nritems);
2079 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2081 /* first correct the data pointers */
2082 for (i = slot; i < nritems; i++) {
2084 item = btrfs_item_nr(leaf, i);
2086 if (!leaf->map_token) {
2087 map_extent_buffer(leaf, (unsigned long)item,
2088 sizeof(struct btrfs_item),
2089 &leaf->map_token, &leaf->kaddr,
2090 &leaf->map_start, &leaf->map_len,
2093 ioff = btrfs_item_offset(leaf, item);
2094 btrfs_set_item_offset(leaf, item, ioff - data_size);
2097 if (leaf->map_token) {
2098 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2099 leaf->map_token = NULL;
2102 /* shift the data */
2103 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2104 data_end - data_size, btrfs_leaf_data(leaf) +
2105 data_end, old_data - data_end);
2107 data_end = old_data;
2108 old_size = btrfs_item_size_nr(leaf, slot);
2109 item = btrfs_item_nr(leaf, slot);
2110 btrfs_set_item_size(leaf, item, old_size + data_size);
2111 btrfs_mark_buffer_dirty(leaf);
2114 if (btrfs_leaf_free_space(root, leaf) < 0) {
2115 btrfs_print_leaf(root, leaf);
2122 * Given a key and some data, insert an item into the tree.
2123 * This does all the path init required, making room in the tree if needed.
2125 int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
2126 struct btrfs_root *root,
2127 struct btrfs_path *path,
2128 struct btrfs_key *cpu_key, u32 data_size)
2130 struct extent_buffer *leaf;
2131 struct btrfs_item *item;
2136 unsigned int data_end;
2137 struct btrfs_disk_key disk_key;
2139 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2141 /* create a root if there isn't one */
2145 ret = btrfs_search_slot(trans, root, cpu_key, path, data_size, 1);
2152 slot_orig = path->slots[0];
2153 leaf = path->nodes[0];
2155 nritems = btrfs_header_nritems(leaf);
2156 data_end = leaf_data_end(root, leaf);
2158 if (btrfs_leaf_free_space(root, leaf) <
2159 sizeof(struct btrfs_item) + data_size) {
2160 btrfs_print_leaf(root, leaf);
2161 printk("not enough freespace need %u have %d\n",
2162 data_size, btrfs_leaf_free_space(root, leaf));
2166 slot = path->slots[0];
2169 if (slot != nritems) {
2171 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2173 if (old_data < data_end) {
2174 btrfs_print_leaf(root, leaf);
2175 printk("slot %d old_data %d data_end %d\n",
2176 slot, old_data, data_end);
2180 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2182 /* first correct the data pointers */
2183 WARN_ON(leaf->map_token);
2184 for (i = slot; i < nritems; i++) {
2187 item = btrfs_item_nr(leaf, i);
2188 if (!leaf->map_token) {
2189 map_extent_buffer(leaf, (unsigned long)item,
2190 sizeof(struct btrfs_item),
2191 &leaf->map_token, &leaf->kaddr,
2192 &leaf->map_start, &leaf->map_len,
2196 ioff = btrfs_item_offset(leaf, item);
2197 btrfs_set_item_offset(leaf, item, ioff - data_size);
2199 if (leaf->map_token) {
2200 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2201 leaf->map_token = NULL;
2204 /* shift the items */
2205 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2206 btrfs_item_nr_offset(slot),
2207 (nritems - slot) * sizeof(struct btrfs_item));
2209 /* shift the data */
2210 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2211 data_end - data_size, btrfs_leaf_data(leaf) +
2212 data_end, old_data - data_end);
2213 data_end = old_data;
2216 /* setup the item for the new data */
2217 btrfs_set_item_key(leaf, &disk_key, slot);
2218 item = btrfs_item_nr(leaf, slot);
2219 btrfs_set_item_offset(leaf, item, data_end - data_size);
2220 btrfs_set_item_size(leaf, item, data_size);
2221 btrfs_set_header_nritems(leaf, nritems + 1);
2222 btrfs_mark_buffer_dirty(leaf);
2226 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2228 if (btrfs_leaf_free_space(root, leaf) < 0) {
2229 btrfs_print_leaf(root, leaf);
2237 * Given a key and some data, insert an item into the tree.
2238 * This does all the path init required, making room in the tree if needed.
2240 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2241 *root, struct btrfs_key *cpu_key, void *data, u32
2245 struct btrfs_path *path;
2246 struct extent_buffer *leaf;
2249 path = btrfs_alloc_path();
2251 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2253 leaf = path->nodes[0];
2254 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2255 write_extent_buffer(leaf, data, ptr, data_size);
2256 btrfs_mark_buffer_dirty(leaf);
2258 btrfs_free_path(path);
2263 * delete the pointer from a given node.
2265 * If the delete empties a node, the node is removed from the tree,
2266 * continuing all the way the root if required. The root is converted into
2267 * a leaf if all the nodes are emptied.
2269 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2270 struct btrfs_path *path, int level, int slot)
2272 struct extent_buffer *parent = path->nodes[level];
2277 nritems = btrfs_header_nritems(parent);
2278 if (slot != nritems -1) {
2279 memmove_extent_buffer(parent,
2280 btrfs_node_key_ptr_offset(slot),
2281 btrfs_node_key_ptr_offset(slot + 1),
2282 sizeof(struct btrfs_key_ptr) *
2283 (nritems - slot - 1));
2286 btrfs_set_header_nritems(parent, nritems);
2287 if (nritems == 0 && parent == root->node) {
2288 BUG_ON(btrfs_header_level(root->node) != 1);
2289 /* just turn the root into a leaf and break */
2290 btrfs_set_header_level(root->node, 0);
2291 } else if (slot == 0) {
2292 struct btrfs_disk_key disk_key;
2294 btrfs_node_key(parent, &disk_key, 0);
2295 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2299 btrfs_mark_buffer_dirty(parent);
2304 * delete the item at the leaf level in path. If that empties
2305 * the leaf, remove it from the tree
2307 int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2308 struct btrfs_path *path)
2311 struct extent_buffer *leaf;
2312 struct btrfs_item *item;
2319 leaf = path->nodes[0];
2320 slot = path->slots[0];
2321 doff = btrfs_item_offset_nr(leaf, slot);
2322 dsize = btrfs_item_size_nr(leaf, slot);
2323 nritems = btrfs_header_nritems(leaf);
2325 if (slot != nritems - 1) {
2327 int data_end = leaf_data_end(root, leaf);
2329 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2331 btrfs_leaf_data(leaf) + data_end,
2334 for (i = slot + 1; i < nritems; i++) {
2337 item = btrfs_item_nr(leaf, i);
2338 if (!leaf->map_token) {
2339 map_extent_buffer(leaf, (unsigned long)item,
2340 sizeof(struct btrfs_item),
2341 &leaf->map_token, &leaf->kaddr,
2342 &leaf->map_start, &leaf->map_len,
2345 ioff = btrfs_item_offset(leaf, item);
2346 btrfs_set_item_offset(leaf, item, ioff + dsize);
2349 if (leaf->map_token) {
2350 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2351 leaf->map_token = NULL;
2354 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2355 btrfs_item_nr_offset(slot + 1),
2356 sizeof(struct btrfs_item) *
2357 (nritems - slot - 1));
2359 btrfs_set_header_nritems(leaf, nritems - 1);
2362 /* delete the leaf if we've emptied it */
2364 if (leaf == root->node) {
2365 btrfs_set_header_level(leaf, 0);
2367 clean_tree_block(trans, root, leaf);
2368 wait_on_tree_block_writeback(root, leaf);
2369 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2372 wret = btrfs_free_extent(trans, root,
2373 leaf->start, leaf->len, 1);
2378 int used = leaf_space_used(leaf, 0, nritems);
2380 struct btrfs_disk_key disk_key;
2382 btrfs_item_key(leaf, &disk_key, 0);
2383 wret = fixup_low_keys(trans, root, path,
2389 /* delete the leaf if it is mostly empty */
2390 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
2391 /* push_leaf_left fixes the path.
2392 * make sure the path still points to our leaf
2393 * for possible call to del_ptr below
2395 slot = path->slots[1];
2396 extent_buffer_get(leaf);
2398 wret = push_leaf_right(trans, root, path, 1);
2399 if (wret < 0 && wret != -ENOSPC)
2402 if (path->nodes[0] == leaf &&
2403 btrfs_header_nritems(leaf)) {
2404 wret = push_leaf_left(trans, root, path, 1);
2405 if (wret < 0 && wret != -ENOSPC)
2409 if (btrfs_header_nritems(leaf) == 0) {
2410 u64 bytenr = leaf->start;
2411 u32 blocksize = leaf->len;
2413 clean_tree_block(trans, root, leaf);
2414 wait_on_tree_block_writeback(root, leaf);
2416 wret = del_ptr(trans, root, path, 1, slot);
2420 free_extent_buffer(leaf);
2421 wret = btrfs_free_extent(trans, root, bytenr,
2426 btrfs_mark_buffer_dirty(leaf);
2427 free_extent_buffer(leaf);
2430 btrfs_mark_buffer_dirty(leaf);
2437 * walk up the tree as far as required to find the next leaf.
2438 * returns 0 if it found something or 1 if there are no greater leaves.
2439 * returns < 0 on io errors.
2441 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2446 struct extent_buffer *c;
2447 struct extent_buffer *next = NULL;
2449 while(level < BTRFS_MAX_LEVEL) {
2450 if (!path->nodes[level])
2453 slot = path->slots[level] + 1;
2454 c = path->nodes[level];
2455 if (slot >= btrfs_header_nritems(c)) {
2460 bytenr = btrfs_node_blockptr(c, slot);
2462 free_extent_buffer(next);
2465 reada_for_search(root, path, level, slot);
2467 next = read_tree_block(root, bytenr,
2468 btrfs_level_size(root, level -1));
2471 path->slots[level] = slot;
2474 c = path->nodes[level];
2475 free_extent_buffer(c);
2476 path->nodes[level] = next;
2477 path->slots[level] = 0;
2481 reada_for_search(root, path, level, 0);
2482 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2483 btrfs_level_size(root, level - 1));