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.
20 #include "transaction.h"
21 #include "print-tree.h"
23 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
24 *root, struct btrfs_path *path, int level);
25 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_key *ins_key,
27 struct btrfs_path *path, int data_size, int extend);
28 static int push_node_left(struct btrfs_trans_handle *trans,
29 struct btrfs_root *root, struct extent_buffer *dst,
30 struct extent_buffer *src);
31 static int balance_node_right(struct btrfs_trans_handle *trans,
32 struct btrfs_root *root,
33 struct extent_buffer *dst_buf,
34 struct extent_buffer *src_buf);
35 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
36 struct btrfs_path *path, int level, int slot);
38 inline void btrfs_init_path(struct btrfs_path *p)
40 memset(p, 0, sizeof(*p));
43 struct btrfs_path *btrfs_alloc_path(void)
45 struct btrfs_path *path;
46 path = kmalloc(sizeof(struct btrfs_path), GFP_NOFS);
48 btrfs_init_path(path);
54 void btrfs_free_path(struct btrfs_path *p)
56 btrfs_release_path(NULL, p);
60 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
63 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
66 free_extent_buffer(p->nodes[i]);
68 memset(p, 0, sizeof(*p));
71 static void add_root_to_dirty_list(struct btrfs_root *root)
73 if (root->track_dirty && list_empty(&root->dirty_list)) {
74 list_add(&root->dirty_list,
75 &root->fs_info->dirty_cowonly_roots);
79 int btrfs_copy_root(struct btrfs_trans_handle *trans,
80 struct btrfs_root *root,
81 struct extent_buffer *buf,
82 struct extent_buffer **cow_ret, u64 new_root_objectid)
84 struct extent_buffer *cow;
88 struct btrfs_key first_key;
89 struct btrfs_root *new_root;
91 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
95 memcpy(new_root, root, sizeof(*new_root));
96 new_root->root_key.objectid = new_root_objectid;
98 WARN_ON(root->ref_cows && trans->transid !=
99 root->fs_info->running_transaction->transid);
100 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
102 level = btrfs_header_level(buf);
103 nritems = btrfs_header_nritems(buf);
106 btrfs_item_key_to_cpu(buf, &first_key, 0);
108 btrfs_node_key_to_cpu(buf, &first_key, 0);
110 first_key.objectid = 0;
112 cow = __btrfs_alloc_free_block(trans, new_root, buf->len,
114 trans->transid, first_key.objectid,
115 level, buf->start, 0);
121 copy_extent_buffer(cow, buf, 0, 0, cow->len);
122 btrfs_set_header_bytenr(cow, cow->start);
123 btrfs_set_header_generation(cow, trans->transid);
124 btrfs_set_header_owner(cow, new_root_objectid);
125 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
127 WARN_ON(btrfs_header_generation(buf) > trans->transid);
128 ret = btrfs_inc_ref(trans, new_root, buf);
134 btrfs_mark_buffer_dirty(cow);
139 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
140 struct btrfs_root *root,
141 struct extent_buffer *buf,
142 struct extent_buffer *parent, int parent_slot,
143 struct extent_buffer **cow_ret,
144 u64 search_start, u64 empty_size)
147 struct extent_buffer *cow;
150 int different_trans = 0;
152 struct btrfs_key first_key;
154 if (root->ref_cows) {
155 root_gen = trans->transid;
160 WARN_ON(root->ref_cows && trans->transid !=
161 root->fs_info->running_transaction->transid);
162 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
164 level = btrfs_header_level(buf);
165 nritems = btrfs_header_nritems(buf);
168 btrfs_item_key_to_cpu(buf, &first_key, 0);
170 btrfs_node_key_to_cpu(buf, &first_key, 0);
172 first_key.objectid = 0;
174 cow = __btrfs_alloc_free_block(trans, root, buf->len,
175 root->root_key.objectid,
176 root_gen, first_key.objectid, level,
177 search_start, empty_size);
181 copy_extent_buffer(cow, buf, 0, 0, cow->len);
182 btrfs_set_header_bytenr(cow, cow->start);
183 btrfs_set_header_generation(cow, trans->transid);
184 btrfs_set_header_owner(cow, root->root_key.objectid);
185 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
187 WARN_ON(btrfs_header_generation(buf) > trans->transid);
188 if (btrfs_header_generation(buf) != trans->transid) {
190 ret = btrfs_inc_ref(trans, root, buf);
194 clean_tree_block(trans, root, buf);
197 if (buf == root->node) {
198 root_gen = btrfs_header_generation(buf);
200 extent_buffer_get(cow);
201 if (buf != root->commit_root) {
202 btrfs_free_extent(trans, root, buf->start,
203 buf->len, root->root_key.objectid,
206 free_extent_buffer(buf);
207 add_root_to_dirty_list(root);
209 root_gen = btrfs_header_generation(parent);
210 btrfs_set_node_blockptr(parent, parent_slot,
212 WARN_ON(trans->transid == 0);
213 btrfs_set_node_ptr_generation(parent, parent_slot,
215 btrfs_mark_buffer_dirty(parent);
216 WARN_ON(btrfs_header_generation(parent) != trans->transid);
217 btrfs_free_extent(trans, root, buf->start, buf->len,
218 btrfs_header_owner(parent), root_gen,
221 free_extent_buffer(buf);
222 btrfs_mark_buffer_dirty(cow);
227 int btrfs_cow_block(struct btrfs_trans_handle *trans,
228 struct btrfs_root *root, struct extent_buffer *buf,
229 struct extent_buffer *parent, int parent_slot,
230 struct extent_buffer **cow_ret)
235 if (trans->transaction != root->fs_info->running_transaction) {
236 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
237 root->fs_info->running_transaction->transid);
241 if (trans->transid != root->fs_info->generation) {
242 printk(KERN_CRIT "trans %llu running %llu\n",
243 (unsigned long long)trans->transid,
244 (unsigned long long)root->fs_info->generation);
247 if (btrfs_header_generation(buf) == trans->transid &&
248 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
253 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
254 ret = __btrfs_cow_block(trans, root, buf, parent,
255 parent_slot, cow_ret, search_start, 0);
260 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
262 if (blocknr < other && other - (blocknr + blocksize) < 32768)
264 if (blocknr > other && blocknr - (other + blocksize) < 32768)
271 * compare two keys in a memcmp fashion
273 int btrfs_comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
277 btrfs_disk_key_to_cpu(&k1, disk);
279 if (k1.objectid > k2->objectid)
281 if (k1.objectid < k2->objectid)
283 if (k1.type > k2->type)
285 if (k1.type < k2->type)
287 if (k1.offset > k2->offset)
289 if (k1.offset < k2->offset)
296 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
297 struct btrfs_root *root, struct extent_buffer *parent,
298 int start_slot, int cache_only, u64 *last_ret,
299 struct btrfs_key *progress)
301 struct extent_buffer *cur;
302 struct extent_buffer *tmp;
304 u64 search_start = *last_ret;
314 int progress_passed = 0;
315 struct btrfs_disk_key disk_key;
317 parent_level = btrfs_header_level(parent);
318 if (cache_only && parent_level != 1)
321 if (trans->transaction != root->fs_info->running_transaction) {
322 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
323 root->fs_info->running_transaction->transid);
326 if (trans->transid != root->fs_info->generation) {
327 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
328 root->fs_info->generation);
332 parent_nritems = btrfs_header_nritems(parent);
333 blocksize = btrfs_level_size(root, parent_level - 1);
334 end_slot = parent_nritems;
336 if (parent_nritems == 1)
339 for (i = start_slot; i < end_slot; i++) {
342 if (!parent->map_token) {
343 map_extent_buffer(parent,
344 btrfs_node_key_ptr_offset(i),
345 sizeof(struct btrfs_key_ptr),
346 &parent->map_token, &parent->kaddr,
347 &parent->map_start, &parent->map_len,
350 btrfs_node_key(parent, &disk_key, i);
351 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
355 blocknr = btrfs_node_blockptr(parent, i);
357 last_block = blocknr;
360 other = btrfs_node_blockptr(parent, i - 1);
361 close = close_blocks(blocknr, other, blocksize);
363 if (close && i < end_slot - 2) {
364 other = btrfs_node_blockptr(parent, i + 1);
365 close = close_blocks(blocknr, other, blocksize);
368 last_block = blocknr;
371 if (parent->map_token) {
372 unmap_extent_buffer(parent, parent->map_token,
374 parent->map_token = NULL;
377 cur = btrfs_find_tree_block(root, blocknr, blocksize);
379 uptodate = btrfs_buffer_uptodate(cur);
382 if (!cur || !uptodate) {
384 free_extent_buffer(cur);
388 cur = read_tree_block(root, blocknr,
390 } else if (!uptodate) {
391 btrfs_read_buffer(cur);
394 if (search_start == 0)
395 search_start = last_block;
397 err = __btrfs_cow_block(trans, root, cur, parent, i,
400 (end_slot - i) * blocksize));
402 free_extent_buffer(cur);
405 search_start = tmp->start;
406 last_block = tmp->start;
407 *last_ret = search_start;
408 if (parent_level == 1)
409 btrfs_clear_buffer_defrag(tmp);
410 free_extent_buffer(tmp);
412 if (parent->map_token) {
413 unmap_extent_buffer(parent, parent->map_token,
415 parent->map_token = NULL;
422 * The leaf data grows from end-to-front in the node.
423 * this returns the address of the start of the last item,
424 * which is the stop of the leaf data stack
426 static inline unsigned int leaf_data_end(struct btrfs_root *root,
427 struct extent_buffer *leaf)
429 u32 nr = btrfs_header_nritems(leaf);
431 return BTRFS_LEAF_DATA_SIZE(root);
432 return btrfs_item_offset_nr(leaf, nr - 1);
435 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
438 struct extent_buffer *parent = NULL;
439 struct extent_buffer *node = path->nodes[level];
440 struct btrfs_disk_key parent_key;
441 struct btrfs_disk_key node_key;
444 struct btrfs_key cpukey;
445 u32 nritems = btrfs_header_nritems(node);
447 if (path->nodes[level + 1])
448 parent = path->nodes[level + 1];
450 slot = path->slots[level];
451 BUG_ON(nritems == 0);
453 parent_slot = path->slots[level + 1];
454 btrfs_node_key(parent, &parent_key, parent_slot);
455 btrfs_node_key(node, &node_key, 0);
456 BUG_ON(memcmp(&parent_key, &node_key,
457 sizeof(struct btrfs_disk_key)));
458 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
459 btrfs_header_bytenr(node));
461 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
463 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
464 btrfs_node_key(node, &node_key, slot);
465 BUG_ON(btrfs_comp_keys(&node_key, &cpukey) <= 0);
467 if (slot < nritems - 1) {
468 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
469 btrfs_node_key(node, &node_key, slot);
470 BUG_ON(btrfs_comp_keys(&node_key, &cpukey) >= 0);
475 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
478 struct extent_buffer *leaf = path->nodes[level];
479 struct extent_buffer *parent = NULL;
481 struct btrfs_key cpukey;
482 struct btrfs_disk_key parent_key;
483 struct btrfs_disk_key leaf_key;
484 int slot = path->slots[0];
486 u32 nritems = btrfs_header_nritems(leaf);
488 if (path->nodes[level + 1])
489 parent = path->nodes[level + 1];
495 parent_slot = path->slots[level + 1];
496 btrfs_node_key(parent, &parent_key, parent_slot);
497 btrfs_item_key(leaf, &leaf_key, 0);
499 BUG_ON(memcmp(&parent_key, &leaf_key,
500 sizeof(struct btrfs_disk_key)));
501 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
502 btrfs_header_bytenr(leaf));
505 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
506 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
507 btrfs_item_key(leaf, &leaf_key, i);
508 if (comp_keys(&leaf_key, &cpukey) >= 0) {
509 btrfs_print_leaf(root, leaf);
510 printk("slot %d offset bad key\n", i);
513 if (btrfs_item_offset_nr(leaf, i) !=
514 btrfs_item_end_nr(leaf, i + 1)) {
515 btrfs_print_leaf(root, leaf);
516 printk("slot %d offset bad\n", i);
520 if (btrfs_item_offset_nr(leaf, i) +
521 btrfs_item_size_nr(leaf, i) !=
522 BTRFS_LEAF_DATA_SIZE(root)) {
523 btrfs_print_leaf(root, leaf);
524 printk("slot %d first offset bad\n", i);
530 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
531 btrfs_print_leaf(root, leaf);
532 printk("slot %d bad size \n", nritems - 1);
537 if (slot != 0 && slot < nritems - 1) {
538 btrfs_item_key(leaf, &leaf_key, slot);
539 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
540 if (btrfs_comp_keys(&leaf_key, &cpukey) <= 0) {
541 btrfs_print_leaf(root, leaf);
542 printk("slot %d offset bad key\n", slot);
545 if (btrfs_item_offset_nr(leaf, slot - 1) !=
546 btrfs_item_end_nr(leaf, slot)) {
547 btrfs_print_leaf(root, leaf);
548 printk("slot %d offset bad\n", slot);
552 if (slot < nritems - 1) {
553 btrfs_item_key(leaf, &leaf_key, slot);
554 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
555 BUG_ON(btrfs_comp_keys(&leaf_key, &cpukey) >= 0);
556 if (btrfs_item_offset_nr(leaf, slot) !=
557 btrfs_item_end_nr(leaf, slot + 1)) {
558 btrfs_print_leaf(root, leaf);
559 printk("slot %d offset bad\n", slot);
563 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
564 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
568 static int noinline check_block(struct btrfs_root *root,
569 struct btrfs_path *path, int level)
573 struct extent_buffer *buf = path->nodes[level];
575 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
576 (unsigned long)btrfs_header_fsid(buf),
578 printk("warning bad block %Lu\n", buf->start);
583 return check_leaf(root, path, level);
584 return check_node(root, path, level);
588 * search for key in the extent_buffer. The items start at offset p,
589 * and they are item_size apart. There are 'max' items in p.
591 * the slot in the array is returned via slot, and it points to
592 * the place where you would insert key if it is not found in
595 * slot may point to max if the key is bigger than all of the keys
597 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
598 int item_size, struct btrfs_key *key,
605 unsigned long offset;
606 struct btrfs_disk_key *tmp;
609 mid = (low + high) / 2;
610 offset = p + mid * item_size;
612 tmp = (struct btrfs_disk_key *)(eb->data + offset);
613 ret = btrfs_comp_keys(tmp, key);
629 * simple bin_search frontend that does the right thing for
632 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
633 int level, int *slot)
636 return generic_bin_search(eb,
637 offsetof(struct btrfs_leaf, items),
638 sizeof(struct btrfs_item),
639 key, btrfs_header_nritems(eb),
642 return generic_bin_search(eb,
643 offsetof(struct btrfs_node, ptrs),
644 sizeof(struct btrfs_key_ptr),
645 key, btrfs_header_nritems(eb),
651 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
652 struct extent_buffer *parent, int slot)
656 if (slot >= btrfs_header_nritems(parent))
658 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
659 btrfs_level_size(root, btrfs_header_level(parent) - 1));
662 static int balance_level(struct btrfs_trans_handle *trans,
663 struct btrfs_root *root,
664 struct btrfs_path *path, int level)
666 struct extent_buffer *right = NULL;
667 struct extent_buffer *mid;
668 struct extent_buffer *left = NULL;
669 struct extent_buffer *parent = NULL;
673 int orig_slot = path->slots[level];
674 int err_on_enospc = 0;
680 mid = path->nodes[level];
681 WARN_ON(btrfs_header_generation(mid) != trans->transid);
683 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
685 if (level < BTRFS_MAX_LEVEL - 1)
686 parent = path->nodes[level + 1];
687 pslot = path->slots[level + 1];
690 * deal with the case where there is only one pointer in the root
691 * by promoting the node below to a root
694 struct extent_buffer *child;
696 if (btrfs_header_nritems(mid) != 1)
699 /* promote the child to a root */
700 child = read_node_slot(root, mid, 0);
702 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
706 add_root_to_dirty_list(root);
707 path->nodes[level] = NULL;
708 clean_tree_block(trans, root, mid);
709 wait_on_tree_block_writeback(root, mid);
710 /* once for the path */
711 free_extent_buffer(mid);
712 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
713 root->root_key.objectid,
714 btrfs_header_generation(mid), 0, 0, 1);
715 /* once for the root ptr */
716 free_extent_buffer(mid);
719 if (btrfs_header_nritems(mid) >
720 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
723 if (btrfs_header_nritems(mid) < 2)
726 left = read_node_slot(root, parent, pslot - 1);
728 wret = btrfs_cow_block(trans, root, left,
729 parent, pslot - 1, &left);
735 right = read_node_slot(root, parent, pslot + 1);
737 wret = btrfs_cow_block(trans, root, right,
738 parent, pslot + 1, &right);
745 /* first, try to make some room in the middle buffer */
747 orig_slot += btrfs_header_nritems(left);
748 wret = push_node_left(trans, root, left, mid);
751 if (btrfs_header_nritems(mid) < 2)
756 * then try to empty the right most buffer into the middle
759 wret = push_node_left(trans, root, mid, right);
760 if (wret < 0 && wret != -ENOSPC)
762 if (btrfs_header_nritems(right) == 0) {
763 u64 bytenr = right->start;
764 u64 generation = btrfs_header_generation(parent);
765 u32 blocksize = right->len;
767 clean_tree_block(trans, root, right);
768 wait_on_tree_block_writeback(root, right);
769 free_extent_buffer(right);
771 wret = del_ptr(trans, root, path, level + 1, pslot +
775 wret = btrfs_free_extent(trans, root, bytenr,
777 btrfs_header_owner(parent),
778 generation, 0, 0, 1);
782 struct btrfs_disk_key right_key;
783 btrfs_node_key(right, &right_key, 0);
784 btrfs_set_node_key(parent, &right_key, pslot + 1);
785 btrfs_mark_buffer_dirty(parent);
788 if (btrfs_header_nritems(mid) == 1) {
790 * we're not allowed to leave a node with one item in the
791 * tree during a delete. A deletion from lower in the tree
792 * could try to delete the only pointer in this node.
793 * So, pull some keys from the left.
794 * There has to be a left pointer at this point because
795 * otherwise we would have pulled some pointers from the
799 wret = balance_node_right(trans, root, mid, left);
806 if (btrfs_header_nritems(mid) == 0) {
807 /* we've managed to empty the middle node, drop it */
808 u64 root_gen = btrfs_header_generation(parent);
809 u64 bytenr = mid->start;
810 u32 blocksize = mid->len;
811 clean_tree_block(trans, root, mid);
812 wait_on_tree_block_writeback(root, mid);
813 free_extent_buffer(mid);
815 wret = del_ptr(trans, root, path, level + 1, pslot);
818 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
819 btrfs_header_owner(parent),
824 /* update the parent key to reflect our changes */
825 struct btrfs_disk_key mid_key;
826 btrfs_node_key(mid, &mid_key, 0);
827 btrfs_set_node_key(parent, &mid_key, pslot);
828 btrfs_mark_buffer_dirty(parent);
831 /* update the path */
833 if (btrfs_header_nritems(left) > orig_slot) {
834 extent_buffer_get(left);
835 path->nodes[level] = left;
836 path->slots[level + 1] -= 1;
837 path->slots[level] = orig_slot;
839 free_extent_buffer(mid);
841 orig_slot -= btrfs_header_nritems(left);
842 path->slots[level] = orig_slot;
845 /* double check we haven't messed things up */
846 check_block(root, path, level);
848 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
852 free_extent_buffer(right);
854 free_extent_buffer(left);
858 /* returns zero if the push worked, non-zero otherwise */
859 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
860 struct btrfs_root *root,
861 struct btrfs_path *path, int level)
863 struct extent_buffer *right = NULL;
864 struct extent_buffer *mid;
865 struct extent_buffer *left = NULL;
866 struct extent_buffer *parent = NULL;
870 int orig_slot = path->slots[level];
876 mid = path->nodes[level];
877 WARN_ON(btrfs_header_generation(mid) != trans->transid);
878 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
880 if (level < BTRFS_MAX_LEVEL - 1)
881 parent = path->nodes[level + 1];
882 pslot = path->slots[level + 1];
887 left = read_node_slot(root, parent, pslot - 1);
889 /* first, try to make some room in the middle buffer */
892 left_nr = btrfs_header_nritems(left);
893 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
896 ret = btrfs_cow_block(trans, root, left, parent,
901 wret = push_node_left(trans, root,
908 struct btrfs_disk_key disk_key;
909 orig_slot += left_nr;
910 btrfs_node_key(mid, &disk_key, 0);
911 btrfs_set_node_key(parent, &disk_key, pslot);
912 btrfs_mark_buffer_dirty(parent);
913 if (btrfs_header_nritems(left) > orig_slot) {
914 path->nodes[level] = left;
915 path->slots[level + 1] -= 1;
916 path->slots[level] = orig_slot;
917 free_extent_buffer(mid);
920 btrfs_header_nritems(left);
921 path->slots[level] = orig_slot;
922 free_extent_buffer(left);
926 free_extent_buffer(left);
928 right= read_node_slot(root, parent, pslot + 1);
931 * then try to empty the right most buffer into the middle
935 right_nr = btrfs_header_nritems(right);
936 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
939 ret = btrfs_cow_block(trans, root, right,
945 wret = balance_node_right(trans, root,
952 struct btrfs_disk_key disk_key;
954 btrfs_node_key(right, &disk_key, 0);
955 btrfs_set_node_key(parent, &disk_key, pslot + 1);
956 btrfs_mark_buffer_dirty(parent);
958 if (btrfs_header_nritems(mid) <= orig_slot) {
959 path->nodes[level] = right;
960 path->slots[level + 1] += 1;
961 path->slots[level] = orig_slot -
962 btrfs_header_nritems(mid);
963 free_extent_buffer(mid);
965 free_extent_buffer(right);
969 free_extent_buffer(right);
975 * readahead one full node of leaves
977 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
978 int level, int slot, u64 objectid)
980 struct extent_buffer *node;
981 struct btrfs_disk_key disk_key;
987 int direction = path->reada;
988 struct extent_buffer *eb;
996 if (!path->nodes[level])
999 node = path->nodes[level];
1000 search = btrfs_node_blockptr(node, slot);
1001 blocksize = btrfs_level_size(root, level - 1);
1002 eb = btrfs_find_tree_block(root, search, blocksize);
1004 free_extent_buffer(eb);
1008 highest_read = search;
1009 lowest_read = search;
1011 nritems = btrfs_header_nritems(node);
1014 if (direction < 0) {
1018 } else if (direction > 0) {
1023 if (path->reada < 0 && objectid) {
1024 btrfs_node_key(node, &disk_key, nr);
1025 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1028 search = btrfs_node_blockptr(node, nr);
1029 if ((search >= lowest_read && search <= highest_read) ||
1030 (search < lowest_read && lowest_read - search <= 32768) ||
1031 (search > highest_read && search - highest_read <= 32768)) {
1032 readahead_tree_block(root, search, blocksize);
1036 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1038 if(nread > (1024 * 1024) || nscan > 128)
1041 if (search < lowest_read)
1042 lowest_read = search;
1043 if (search > highest_read)
1044 highest_read = search;
1049 * look for key in the tree. path is filled in with nodes along the way
1050 * if key is found, we return zero and you can find the item in the leaf
1051 * level of the path (level 0)
1053 * If the key isn't found, the path points to the slot where it should
1054 * be inserted, and 1 is returned. If there are other errors during the
1055 * search a negative error number is returned.
1057 * if ins_len > 0, nodes and leaves will be split as we walk down the
1058 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1061 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1062 *root, struct btrfs_key *key, struct btrfs_path *p, int
1065 struct extent_buffer *b;
1071 int should_reada = p->reada;
1072 u8 lowest_level = 0;
1074 lowest_level = p->lowest_level;
1075 WARN_ON(lowest_level && ins_len);
1076 WARN_ON(p->nodes[0] != NULL);
1078 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1082 extent_buffer_get(b);
1084 level = btrfs_header_level(b);
1087 wret = btrfs_cow_block(trans, root, b,
1088 p->nodes[level + 1],
1089 p->slots[level + 1],
1092 free_extent_buffer(b);
1096 BUG_ON(!cow && ins_len);
1097 if (level != btrfs_header_level(b))
1099 level = btrfs_header_level(b);
1100 p->nodes[level] = b;
1101 ret = check_block(root, p, level);
1104 ret = bin_search(b, key, level, &slot);
1106 if (ret && slot > 0)
1108 p->slots[level] = slot;
1109 if (ins_len > 0 && btrfs_header_nritems(b) >=
1110 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1111 int sret = split_node(trans, root, p, level);
1115 b = p->nodes[level];
1116 slot = p->slots[level];
1117 } else if (ins_len < 0) {
1118 int sret = balance_level(trans, root, p,
1122 b = p->nodes[level];
1124 btrfs_release_path(NULL, p);
1127 slot = p->slots[level];
1128 BUG_ON(btrfs_header_nritems(b) == 1);
1130 /* this is only true while dropping a snapshot */
1131 if (level == lowest_level)
1133 bytenr = btrfs_node_blockptr(b, slot);
1134 ptr_gen = btrfs_node_ptr_generation(b, slot);
1136 reada_for_search(root, p, level, slot,
1138 b = read_tree_block(root, bytenr,
1139 btrfs_level_size(root, level - 1));
1140 if (ptr_gen != btrfs_header_generation(b)) {
1141 printk("block %llu bad gen wanted %llu "
1143 (unsigned long long)b->start,
1144 (unsigned long long)ptr_gen,
1145 (unsigned long long)btrfs_header_generation(b));
1148 p->slots[level] = slot;
1149 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1150 sizeof(struct btrfs_item) + ins_len) {
1151 int sret = split_leaf(trans, root, key,
1152 p, ins_len, ret == 0);
1164 * adjust the pointers going up the tree, starting at level
1165 * making sure the right key of each node is points to 'key'.
1166 * This is used after shifting pointers to the left, so it stops
1167 * fixing up pointers when a given leaf/node is not in slot 0 of the
1170 * If this fails to write a tree block, it returns -1, but continues
1171 * fixing up the blocks in ram so the tree is consistent.
1173 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1174 struct btrfs_root *root, struct btrfs_path *path,
1175 struct btrfs_disk_key *key, int level)
1179 struct extent_buffer *t;
1181 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1182 int tslot = path->slots[i];
1183 if (!path->nodes[i])
1186 btrfs_set_node_key(t, key, tslot);
1187 btrfs_mark_buffer_dirty(path->nodes[i]);
1195 * try to push data from one node into the next node left in the
1198 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1199 * error, and > 0 if there was no room in the left hand block.
1201 static int push_node_left(struct btrfs_trans_handle *trans,
1202 struct btrfs_root *root, struct extent_buffer *dst,
1203 struct extent_buffer *src)
1210 src_nritems = btrfs_header_nritems(src);
1211 dst_nritems = btrfs_header_nritems(dst);
1212 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1213 WARN_ON(btrfs_header_generation(src) != trans->transid);
1214 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1216 if (push_items <= 0) {
1220 if (src_nritems < push_items)
1221 push_items = src_nritems;
1223 copy_extent_buffer(dst, src,
1224 btrfs_node_key_ptr_offset(dst_nritems),
1225 btrfs_node_key_ptr_offset(0),
1226 push_items * sizeof(struct btrfs_key_ptr));
1228 if (push_items < src_nritems) {
1229 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1230 btrfs_node_key_ptr_offset(push_items),
1231 (src_nritems - push_items) *
1232 sizeof(struct btrfs_key_ptr));
1234 btrfs_set_header_nritems(src, src_nritems - push_items);
1235 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1236 btrfs_mark_buffer_dirty(src);
1237 btrfs_mark_buffer_dirty(dst);
1242 * try to push data from one node into the next node right in the
1245 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1246 * error, and > 0 if there was no room in the right hand block.
1248 * this will only push up to 1/2 the contents of the left node over
1250 static int balance_node_right(struct btrfs_trans_handle *trans,
1251 struct btrfs_root *root,
1252 struct extent_buffer *dst,
1253 struct extent_buffer *src)
1261 WARN_ON(btrfs_header_generation(src) != trans->transid);
1262 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1264 src_nritems = btrfs_header_nritems(src);
1265 dst_nritems = btrfs_header_nritems(dst);
1266 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1267 if (push_items <= 0)
1270 max_push = src_nritems / 2 + 1;
1271 /* don't try to empty the node */
1272 if (max_push >= src_nritems)
1275 if (max_push < push_items)
1276 push_items = max_push;
1278 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1279 btrfs_node_key_ptr_offset(0),
1281 sizeof(struct btrfs_key_ptr));
1283 copy_extent_buffer(dst, src,
1284 btrfs_node_key_ptr_offset(0),
1285 btrfs_node_key_ptr_offset(src_nritems - push_items),
1286 push_items * sizeof(struct btrfs_key_ptr));
1288 btrfs_set_header_nritems(src, src_nritems - push_items);
1289 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1291 btrfs_mark_buffer_dirty(src);
1292 btrfs_mark_buffer_dirty(dst);
1297 * helper function to insert a new root level in the tree.
1298 * A new node is allocated, and a single item is inserted to
1299 * point to the existing root
1301 * returns zero on success or < 0 on failure.
1303 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1304 struct btrfs_root *root,
1305 struct btrfs_path *path, int level)
1309 struct extent_buffer *lower;
1310 struct extent_buffer *c;
1311 struct btrfs_disk_key lower_key;
1313 BUG_ON(path->nodes[level]);
1314 BUG_ON(path->nodes[level-1] != root->node);
1317 root_gen = trans->transid;
1321 lower = path->nodes[level-1];
1323 btrfs_item_key(lower, &lower_key, 0);
1325 btrfs_node_key(lower, &lower_key, 0);
1327 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1328 root->root_key.objectid,
1329 root_gen, lower_key.objectid, level,
1330 root->node->start, 0);
1333 memset_extent_buffer(c, 0, 0, root->nodesize);
1334 btrfs_set_header_nritems(c, 1);
1335 btrfs_set_header_level(c, level);
1336 btrfs_set_header_bytenr(c, c->start);
1337 btrfs_set_header_generation(c, trans->transid);
1338 btrfs_set_header_owner(c, root->root_key.objectid);
1340 write_extent_buffer(c, root->fs_info->fsid,
1341 (unsigned long)btrfs_header_fsid(c),
1344 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1345 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1348 btrfs_set_node_key(c, &lower_key, 0);
1349 btrfs_set_node_blockptr(c, 0, lower->start);
1350 lower_gen = btrfs_header_generation(lower);
1351 WARN_ON(lower_gen == 0);
1353 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1355 btrfs_mark_buffer_dirty(c);
1357 /* the super has an extra ref to root->node */
1358 free_extent_buffer(root->node);
1360 add_root_to_dirty_list(root);
1361 extent_buffer_get(c);
1362 path->nodes[level] = c;
1363 path->slots[level] = 0;
1365 if (root->ref_cows && lower_gen != trans->transid) {
1366 struct btrfs_path *back_path = btrfs_alloc_path();
1368 ret = btrfs_insert_extent_backref(trans,
1369 root->fs_info->extent_root,
1371 root->root_key.objectid,
1372 trans->transid, 0, 0);
1374 btrfs_free_path(back_path);
1380 * worker function to insert a single pointer in a node.
1381 * the node should have enough room for the pointer already
1383 * slot and level indicate where you want the key to go, and
1384 * blocknr is the block the key points to.
1386 * returns zero on success and < 0 on any error
1388 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1389 *root, struct btrfs_path *path, struct btrfs_disk_key
1390 *key, u64 bytenr, int slot, int level)
1392 struct extent_buffer *lower;
1395 BUG_ON(!path->nodes[level]);
1396 lower = path->nodes[level];
1397 nritems = btrfs_header_nritems(lower);
1400 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1402 if (slot != nritems) {
1403 memmove_extent_buffer(lower,
1404 btrfs_node_key_ptr_offset(slot + 1),
1405 btrfs_node_key_ptr_offset(slot),
1406 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1408 btrfs_set_node_key(lower, key, slot);
1409 btrfs_set_node_blockptr(lower, slot, bytenr);
1410 WARN_ON(trans->transid == 0);
1411 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1412 btrfs_set_header_nritems(lower, nritems + 1);
1413 btrfs_mark_buffer_dirty(lower);
1418 * split the node at the specified level in path in two.
1419 * The path is corrected to point to the appropriate node after the split
1421 * Before splitting this tries to make some room in the node by pushing
1422 * left and right, if either one works, it returns right away.
1424 * returns 0 on success and < 0 on failure
1426 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1427 *root, struct btrfs_path *path, int level)
1430 struct extent_buffer *c;
1431 struct extent_buffer *split;
1432 struct btrfs_disk_key disk_key;
1438 c = path->nodes[level];
1439 WARN_ON(btrfs_header_generation(c) != trans->transid);
1440 if (c == root->node) {
1441 /* trying to split the root, lets make a new one */
1442 ret = insert_new_root(trans, root, path, level + 1);
1446 ret = push_nodes_for_insert(trans, root, path, level);
1447 c = path->nodes[level];
1448 if (!ret && btrfs_header_nritems(c) <
1449 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1455 c_nritems = btrfs_header_nritems(c);
1457 root_gen = trans->transid;
1461 btrfs_node_key(c, &disk_key, 0);
1462 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1463 root->root_key.objectid,
1465 btrfs_disk_key_objectid(&disk_key),
1466 level, c->start, 0);
1468 return PTR_ERR(split);
1470 btrfs_set_header_flags(split, btrfs_header_flags(c));
1471 btrfs_set_header_level(split, btrfs_header_level(c));
1472 btrfs_set_header_bytenr(split, split->start);
1473 btrfs_set_header_generation(split, trans->transid);
1474 btrfs_set_header_owner(split, root->root_key.objectid);
1475 btrfs_set_header_flags(split, 0);
1476 write_extent_buffer(split, root->fs_info->fsid,
1477 (unsigned long)btrfs_header_fsid(split),
1479 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1480 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1483 mid = (c_nritems + 1) / 2;
1485 copy_extent_buffer(split, c,
1486 btrfs_node_key_ptr_offset(0),
1487 btrfs_node_key_ptr_offset(mid),
1488 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1489 btrfs_set_header_nritems(split, c_nritems - mid);
1490 btrfs_set_header_nritems(c, mid);
1493 btrfs_mark_buffer_dirty(c);
1494 btrfs_mark_buffer_dirty(split);
1496 btrfs_node_key(split, &disk_key, 0);
1497 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1498 path->slots[level + 1] + 1,
1503 if (path->slots[level] >= mid) {
1504 path->slots[level] -= mid;
1505 free_extent_buffer(c);
1506 path->nodes[level] = split;
1507 path->slots[level + 1] += 1;
1509 free_extent_buffer(split);
1515 * how many bytes are required to store the items in a leaf. start
1516 * and nr indicate which items in the leaf to check. This totals up the
1517 * space used both by the item structs and the item data
1519 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1522 int nritems = btrfs_header_nritems(l);
1523 int end = min(nritems, start + nr) - 1;
1527 data_len = btrfs_item_end_nr(l, start);
1528 data_len = data_len - btrfs_item_offset_nr(l, end);
1529 data_len += sizeof(struct btrfs_item) * nr;
1530 WARN_ON(data_len < 0);
1535 * The space between the end of the leaf items and
1536 * the start of the leaf data. IOW, how much room
1537 * the leaf has left for both items and data
1539 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1541 int nritems = btrfs_header_nritems(leaf);
1543 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1545 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1546 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1547 leaf_space_used(leaf, 0, nritems), nritems);
1553 * push some data in the path leaf to the right, trying to free up at
1554 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1556 * returns 1 if the push failed because the other node didn't have enough
1557 * room, 0 if everything worked out and < 0 if there were major errors.
1559 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1560 *root, struct btrfs_path *path, int data_size,
1563 struct extent_buffer *left = path->nodes[0];
1564 struct extent_buffer *right;
1565 struct extent_buffer *upper;
1566 struct btrfs_disk_key disk_key;
1572 struct btrfs_item *item;
1580 slot = path->slots[1];
1581 if (!path->nodes[1]) {
1584 upper = path->nodes[1];
1585 if (slot >= btrfs_header_nritems(upper) - 1)
1588 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1590 free_space = btrfs_leaf_free_space(root, right);
1591 if (free_space < data_size + sizeof(struct btrfs_item)) {
1592 free_extent_buffer(right);
1596 /* cow and double check */
1597 ret = btrfs_cow_block(trans, root, right, upper,
1600 free_extent_buffer(right);
1603 free_space = btrfs_leaf_free_space(root, right);
1604 if (free_space < data_size + sizeof(struct btrfs_item)) {
1605 free_extent_buffer(right);
1609 left_nritems = btrfs_header_nritems(left);
1610 if (left_nritems == 0) {
1611 free_extent_buffer(right);
1620 i = left_nritems - 1;
1622 item = btrfs_item_nr(left, i);
1624 if (path->slots[0] == i)
1625 push_space += data_size + sizeof(*item);
1627 this_item_size = btrfs_item_size(left, item);
1628 if (this_item_size + sizeof(*item) + push_space > free_space)
1631 push_space += this_item_size + sizeof(*item);
1637 if (push_items == 0) {
1638 free_extent_buffer(right);
1642 if (!empty && push_items == left_nritems)
1645 /* push left to right */
1646 right_nritems = btrfs_header_nritems(right);
1648 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1649 push_space -= leaf_data_end(root, left);
1651 /* make room in the right data area */
1652 data_end = leaf_data_end(root, right);
1653 memmove_extent_buffer(right,
1654 btrfs_leaf_data(right) + data_end - push_space,
1655 btrfs_leaf_data(right) + data_end,
1656 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1658 /* copy from the left data area */
1659 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1660 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1661 btrfs_leaf_data(left) + leaf_data_end(root, left),
1664 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1665 btrfs_item_nr_offset(0),
1666 right_nritems * sizeof(struct btrfs_item));
1668 /* copy the items from left to right */
1669 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1670 btrfs_item_nr_offset(left_nritems - push_items),
1671 push_items * sizeof(struct btrfs_item));
1673 /* update the item pointers */
1674 right_nritems += push_items;
1675 btrfs_set_header_nritems(right, right_nritems);
1676 push_space = BTRFS_LEAF_DATA_SIZE(root);
1677 for (i = 0; i < right_nritems; i++) {
1678 item = btrfs_item_nr(right, i);
1679 push_space -= btrfs_item_size(right, item);
1680 btrfs_set_item_offset(right, item, push_space);
1683 left_nritems -= push_items;
1684 btrfs_set_header_nritems(left, left_nritems);
1687 btrfs_mark_buffer_dirty(left);
1688 btrfs_mark_buffer_dirty(right);
1690 btrfs_item_key(right, &disk_key, 0);
1691 btrfs_set_node_key(upper, &disk_key, slot + 1);
1692 btrfs_mark_buffer_dirty(upper);
1694 /* then fixup the leaf pointer in the path */
1695 if (path->slots[0] >= left_nritems) {
1696 path->slots[0] -= left_nritems;
1697 free_extent_buffer(path->nodes[0]);
1698 path->nodes[0] = right;
1699 path->slots[1] += 1;
1701 free_extent_buffer(right);
1706 * push some data in the path leaf to the left, trying to free up at
1707 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1709 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1710 *root, struct btrfs_path *path, int data_size,
1713 struct btrfs_disk_key disk_key;
1714 struct extent_buffer *right = path->nodes[0];
1715 struct extent_buffer *left;
1721 struct btrfs_item *item;
1722 u32 old_left_nritems;
1728 u32 old_left_item_size;
1730 slot = path->slots[1];
1733 if (!path->nodes[1])
1736 right_nritems = btrfs_header_nritems(right);
1737 if (right_nritems == 0) {
1741 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1742 slot - 1), root->leafsize);
1743 free_space = btrfs_leaf_free_space(root, left);
1744 if (free_space < data_size + sizeof(struct btrfs_item)) {
1745 free_extent_buffer(left);
1749 /* cow and double check */
1750 ret = btrfs_cow_block(trans, root, left,
1751 path->nodes[1], slot - 1, &left);
1753 /* we hit -ENOSPC, but it isn't fatal here */
1754 free_extent_buffer(left);
1758 free_space = btrfs_leaf_free_space(root, left);
1759 if (free_space < data_size + sizeof(struct btrfs_item)) {
1760 free_extent_buffer(left);
1767 nr = right_nritems - 1;
1769 for (i = 0; i < nr; i++) {
1770 item = btrfs_item_nr(right, i);
1772 if (path->slots[0] == i)
1773 push_space += data_size + sizeof(*item);
1775 this_item_size = btrfs_item_size(right, item);
1776 if (this_item_size + sizeof(*item) + push_space > free_space)
1780 push_space += this_item_size + sizeof(*item);
1783 if (push_items == 0) {
1784 free_extent_buffer(left);
1787 if (!empty && push_items == btrfs_header_nritems(right))
1790 /* push data from right to left */
1791 copy_extent_buffer(left, right,
1792 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1793 btrfs_item_nr_offset(0),
1794 push_items * sizeof(struct btrfs_item));
1796 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1797 btrfs_item_offset_nr(right, push_items -1);
1799 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1800 leaf_data_end(root, left) - push_space,
1801 btrfs_leaf_data(right) +
1802 btrfs_item_offset_nr(right, push_items - 1),
1804 old_left_nritems = btrfs_header_nritems(left);
1805 BUG_ON(old_left_nritems < 0);
1807 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1808 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1811 item = btrfs_item_nr(left, i);
1812 ioff = btrfs_item_offset(left, item);
1813 btrfs_set_item_offset(left, item,
1814 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1816 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1818 /* fixup right node */
1819 if (push_items > right_nritems) {
1820 printk("push items %d nr %u\n", push_items, right_nritems);
1824 if (push_items < right_nritems) {
1825 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1826 leaf_data_end(root, right);
1827 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1828 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1829 btrfs_leaf_data(right) +
1830 leaf_data_end(root, right), push_space);
1832 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1833 btrfs_item_nr_offset(push_items),
1834 (btrfs_header_nritems(right) - push_items) *
1835 sizeof(struct btrfs_item));
1837 right_nritems -= push_items;
1838 btrfs_set_header_nritems(right, right_nritems);
1839 push_space = BTRFS_LEAF_DATA_SIZE(root);
1840 for (i = 0; i < right_nritems; i++) {
1841 item = btrfs_item_nr(right, i);
1842 push_space = push_space - btrfs_item_size(right, item);
1843 btrfs_set_item_offset(right, item, push_space);
1846 btrfs_mark_buffer_dirty(left);
1848 btrfs_mark_buffer_dirty(right);
1850 btrfs_item_key(right, &disk_key, 0);
1851 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1855 /* then fixup the leaf pointer in the path */
1856 if (path->slots[0] < push_items) {
1857 path->slots[0] += old_left_nritems;
1858 free_extent_buffer(path->nodes[0]);
1859 path->nodes[0] = left;
1860 path->slots[1] -= 1;
1862 free_extent_buffer(left);
1863 path->slots[0] -= push_items;
1865 BUG_ON(path->slots[0] < 0);
1870 * split the path's leaf in two, making sure there is at least data_size
1871 * available for the resulting leaf level of the path.
1873 * returns 0 if all went well and < 0 on failure.
1875 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1876 *root, struct btrfs_key *ins_key,
1877 struct btrfs_path *path, int data_size, int extend)
1880 struct extent_buffer *l;
1884 struct extent_buffer *right;
1885 int space_needed = data_size + sizeof(struct btrfs_item);
1892 int num_doubles = 0;
1893 struct btrfs_disk_key disk_key;
1896 space_needed = data_size;
1899 root_gen = trans->transid;
1903 /* first try to make some room by pushing left and right */
1904 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1905 wret = push_leaf_right(trans, root, path, data_size, 0);
1910 wret = push_leaf_left(trans, root, path, data_size, 0);
1916 /* did the pushes work? */
1917 if (btrfs_leaf_free_space(root, l) >= space_needed)
1921 if (!path->nodes[1]) {
1922 ret = insert_new_root(trans, root, path, 1);
1929 slot = path->slots[0];
1930 nritems = btrfs_header_nritems(l);
1931 mid = (nritems + 1)/ 2;
1933 btrfs_item_key(l, &disk_key, 0);
1935 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
1936 root->root_key.objectid,
1937 root_gen, disk_key.objectid, 0,
1939 if (IS_ERR(right)) {
1941 return PTR_ERR(right);
1944 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1945 btrfs_set_header_bytenr(right, right->start);
1946 btrfs_set_header_generation(right, trans->transid);
1947 btrfs_set_header_owner(right, root->root_key.objectid);
1948 btrfs_set_header_level(right, 0);
1949 write_extent_buffer(right, root->fs_info->fsid,
1950 (unsigned long)btrfs_header_fsid(right),
1953 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
1954 (unsigned long)btrfs_header_chunk_tree_uuid(right),
1958 leaf_space_used(l, mid, nritems - mid) + space_needed >
1959 BTRFS_LEAF_DATA_SIZE(root)) {
1960 if (slot >= nritems) {
1961 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1962 btrfs_set_header_nritems(right, 0);
1963 wret = insert_ptr(trans, root, path,
1964 &disk_key, right->start,
1965 path->slots[1] + 1, 1);
1968 free_extent_buffer(path->nodes[0]);
1969 path->nodes[0] = right;
1971 path->slots[1] += 1;
1975 if (mid != nritems &&
1976 leaf_space_used(l, mid, nritems - mid) +
1977 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
1982 if (leaf_space_used(l, 0, mid + 1) + space_needed >
1983 BTRFS_LEAF_DATA_SIZE(root)) {
1984 if (!extend && slot == 0) {
1985 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1986 btrfs_set_header_nritems(right, 0);
1987 wret = insert_ptr(trans, root, path,
1993 free_extent_buffer(path->nodes[0]);
1994 path->nodes[0] = right;
1996 if (path->slots[1] == 0) {
1997 wret = fixup_low_keys(trans, root,
1998 path, &disk_key, 1);
2003 } else if (extend && slot == 0) {
2007 if (mid != nritems &&
2008 leaf_space_used(l, mid, nritems - mid) +
2009 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2015 nritems = nritems - mid;
2016 btrfs_set_header_nritems(right, nritems);
2017 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2019 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2020 btrfs_item_nr_offset(mid),
2021 nritems * sizeof(struct btrfs_item));
2023 copy_extent_buffer(right, l,
2024 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2025 data_copy_size, btrfs_leaf_data(l) +
2026 leaf_data_end(root, l), data_copy_size);
2028 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2029 btrfs_item_end_nr(l, mid);
2031 for (i = 0; i < nritems; i++) {
2032 struct btrfs_item *item = btrfs_item_nr(right, i);
2033 u32 ioff = btrfs_item_offset(right, item);
2034 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2037 btrfs_set_header_nritems(l, mid);
2039 btrfs_item_key(right, &disk_key, 0);
2040 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2041 path->slots[1] + 1, 1);
2045 btrfs_mark_buffer_dirty(right);
2046 btrfs_mark_buffer_dirty(l);
2047 BUG_ON(path->slots[0] != slot);
2050 free_extent_buffer(path->nodes[0]);
2051 path->nodes[0] = right;
2052 path->slots[0] -= mid;
2053 path->slots[1] += 1;
2055 free_extent_buffer(right);
2057 BUG_ON(path->slots[0] < 0);
2060 BUG_ON(num_doubles != 0);
2067 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2068 struct btrfs_root *root,
2069 struct btrfs_path *path,
2070 u32 new_size, int from_end)
2075 struct extent_buffer *leaf;
2076 struct btrfs_item *item;
2078 unsigned int data_end;
2079 unsigned int old_data_start;
2080 unsigned int old_size;
2081 unsigned int size_diff;
2084 slot_orig = path->slots[0];
2085 leaf = path->nodes[0];
2086 slot = path->slots[0];
2088 old_size = btrfs_item_size_nr(leaf, slot);
2089 if (old_size == new_size)
2092 nritems = btrfs_header_nritems(leaf);
2093 data_end = leaf_data_end(root, leaf);
2095 old_data_start = btrfs_item_offset_nr(leaf, slot);
2097 size_diff = old_size - new_size;
2100 BUG_ON(slot >= nritems);
2103 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2105 /* first correct the data pointers */
2106 for (i = slot; i < nritems; i++) {
2108 item = btrfs_item_nr(leaf, i);
2109 ioff = btrfs_item_offset(leaf, item);
2110 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2113 /* shift the data */
2115 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2116 data_end + size_diff, btrfs_leaf_data(leaf) +
2117 data_end, old_data_start + new_size - data_end);
2119 struct btrfs_disk_key disk_key;
2122 btrfs_item_key(leaf, &disk_key, slot);
2124 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2126 struct btrfs_file_extent_item *fi;
2128 fi = btrfs_item_ptr(leaf, slot,
2129 struct btrfs_file_extent_item);
2130 fi = (struct btrfs_file_extent_item *)(
2131 (unsigned long)fi - size_diff);
2133 if (btrfs_file_extent_type(leaf, fi) ==
2134 BTRFS_FILE_EXTENT_INLINE) {
2135 ptr = btrfs_item_ptr_offset(leaf, slot);
2136 memmove_extent_buffer(leaf, ptr,
2138 offsetof(struct btrfs_file_extent_item,
2143 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2144 data_end + size_diff, btrfs_leaf_data(leaf) +
2145 data_end, old_data_start - data_end);
2147 offset = btrfs_disk_key_offset(&disk_key);
2148 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2149 btrfs_set_item_key(leaf, &disk_key, slot);
2151 fixup_low_keys(trans, root, path, &disk_key, 1);
2154 item = btrfs_item_nr(leaf, slot);
2155 btrfs_set_item_size(leaf, item, new_size);
2156 btrfs_mark_buffer_dirty(leaf);
2159 if (btrfs_leaf_free_space(root, leaf) < 0) {
2160 btrfs_print_leaf(root, leaf);
2166 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2167 struct btrfs_root *root, struct btrfs_path *path,
2173 struct extent_buffer *leaf;
2174 struct btrfs_item *item;
2176 unsigned int data_end;
2177 unsigned int old_data;
2178 unsigned int old_size;
2181 slot_orig = path->slots[0];
2182 leaf = path->nodes[0];
2184 nritems = btrfs_header_nritems(leaf);
2185 data_end = leaf_data_end(root, leaf);
2187 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2188 btrfs_print_leaf(root, leaf);
2191 slot = path->slots[0];
2192 old_data = btrfs_item_end_nr(leaf, slot);
2195 if (slot >= nritems) {
2196 btrfs_print_leaf(root, leaf);
2197 printk("slot %d too large, nritems %d\n", slot, nritems);
2202 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2204 /* first correct the data pointers */
2205 for (i = slot; i < nritems; i++) {
2207 item = btrfs_item_nr(leaf, i);
2208 ioff = btrfs_item_offset(leaf, item);
2209 btrfs_set_item_offset(leaf, item, ioff - data_size);
2212 /* shift the data */
2213 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2214 data_end - data_size, btrfs_leaf_data(leaf) +
2215 data_end, old_data - data_end);
2217 data_end = old_data;
2218 old_size = btrfs_item_size_nr(leaf, slot);
2219 item = btrfs_item_nr(leaf, slot);
2220 btrfs_set_item_size(leaf, item, old_size + data_size);
2221 btrfs_mark_buffer_dirty(leaf);
2224 if (btrfs_leaf_free_space(root, leaf) < 0) {
2225 btrfs_print_leaf(root, leaf);
2232 * Given a key and some data, insert an item into the tree.
2233 * This does all the path init required, making room in the tree if needed.
2235 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2236 struct btrfs_root *root,
2237 struct btrfs_path *path,
2238 struct btrfs_key *cpu_key, u32 *data_size,
2241 struct extent_buffer *leaf;
2242 struct btrfs_item *item;
2250 unsigned int data_end;
2251 struct btrfs_disk_key disk_key;
2253 for (i = 0; i < nr; i++) {
2254 total_data += data_size[i];
2257 /* create a root if there isn't one */
2261 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2262 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2269 slot_orig = path->slots[0];
2270 leaf = path->nodes[0];
2272 nritems = btrfs_header_nritems(leaf);
2273 data_end = leaf_data_end(root, leaf);
2275 if (btrfs_leaf_free_space(root, leaf) <
2276 sizeof(struct btrfs_item) + total_size) {
2277 btrfs_print_leaf(root, leaf);
2278 printk("not enough freespace need %u have %d\n",
2279 total_size, btrfs_leaf_free_space(root, leaf));
2283 slot = path->slots[0];
2286 if (slot != nritems) {
2288 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2290 if (old_data < data_end) {
2291 btrfs_print_leaf(root, leaf);
2292 printk("slot %d old_data %d data_end %d\n",
2293 slot, old_data, data_end);
2297 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2299 /* first correct the data pointers */
2300 for (i = slot; i < nritems; i++) {
2303 item = btrfs_item_nr(leaf, i);
2304 ioff = btrfs_item_offset(leaf, item);
2305 btrfs_set_item_offset(leaf, item, ioff - total_data);
2308 /* shift the items */
2309 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2310 btrfs_item_nr_offset(slot),
2311 (nritems - slot) * sizeof(struct btrfs_item));
2313 /* shift the data */
2314 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2315 data_end - total_data, btrfs_leaf_data(leaf) +
2316 data_end, old_data - data_end);
2317 data_end = old_data;
2320 /* setup the item for the new data */
2321 for (i = 0; i < nr; i++) {
2322 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2323 btrfs_set_item_key(leaf, &disk_key, slot + i);
2324 item = btrfs_item_nr(leaf, slot + i);
2325 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2326 data_end -= data_size[i];
2327 btrfs_set_item_size(leaf, item, data_size[i]);
2329 btrfs_set_header_nritems(leaf, nritems + nr);
2330 btrfs_mark_buffer_dirty(leaf);
2334 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2335 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2338 if (btrfs_leaf_free_space(root, leaf) < 0) {
2339 btrfs_print_leaf(root, leaf);
2348 * Given a key and some data, insert an item into the tree.
2349 * This does all the path init required, making room in the tree if needed.
2351 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2352 *root, struct btrfs_key *cpu_key, void *data, u32
2356 struct btrfs_path *path;
2357 struct extent_buffer *leaf;
2360 path = btrfs_alloc_path();
2362 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2364 leaf = path->nodes[0];
2365 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2366 write_extent_buffer(leaf, data, ptr, data_size);
2367 btrfs_mark_buffer_dirty(leaf);
2369 btrfs_free_path(path);
2374 * delete the pointer from a given node.
2376 * If the delete empties a node, the node is removed from the tree,
2377 * continuing all the way the root if required. The root is converted into
2378 * a leaf if all the nodes are emptied.
2380 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2381 struct btrfs_path *path, int level, int slot)
2383 struct extent_buffer *parent = path->nodes[level];
2388 nritems = btrfs_header_nritems(parent);
2389 if (slot != nritems -1) {
2390 memmove_extent_buffer(parent,
2391 btrfs_node_key_ptr_offset(slot),
2392 btrfs_node_key_ptr_offset(slot + 1),
2393 sizeof(struct btrfs_key_ptr) *
2394 (nritems - slot - 1));
2397 btrfs_set_header_nritems(parent, nritems);
2398 if (nritems == 0 && parent == root->node) {
2399 BUG_ON(btrfs_header_level(root->node) != 1);
2400 /* just turn the root into a leaf and break */
2401 btrfs_set_header_level(root->node, 0);
2402 } else if (slot == 0) {
2403 struct btrfs_disk_key disk_key;
2405 btrfs_node_key(parent, &disk_key, 0);
2406 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2410 btrfs_mark_buffer_dirty(parent);
2415 * delete the item at the leaf level in path. If that empties
2416 * the leaf, remove it from the tree
2418 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2419 struct btrfs_path *path, int slot, int nr)
2421 struct extent_buffer *leaf;
2422 struct btrfs_item *item;
2430 leaf = path->nodes[0];
2431 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2433 for (i = 0; i < nr; i++)
2434 dsize += btrfs_item_size_nr(leaf, slot + i);
2436 nritems = btrfs_header_nritems(leaf);
2438 if (slot + nr != nritems) {
2440 int data_end = leaf_data_end(root, leaf);
2442 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2444 btrfs_leaf_data(leaf) + data_end,
2445 last_off - data_end);
2447 for (i = slot + nr; i < nritems; i++) {
2450 item = btrfs_item_nr(leaf, i);
2451 ioff = btrfs_item_offset(leaf, item);
2452 btrfs_set_item_offset(leaf, item, ioff + dsize);
2455 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2456 btrfs_item_nr_offset(slot + nr),
2457 sizeof(struct btrfs_item) *
2458 (nritems - slot - nr));
2460 btrfs_set_header_nritems(leaf, nritems - nr);
2463 /* delete the leaf if we've emptied it */
2465 if (leaf == root->node) {
2466 btrfs_set_header_level(leaf, 0);
2468 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2469 clean_tree_block(trans, root, leaf);
2470 wait_on_tree_block_writeback(root, leaf);
2471 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2474 wret = btrfs_free_extent(trans, root,
2475 leaf->start, leaf->len,
2476 btrfs_header_owner(path->nodes[1]),
2482 int used = leaf_space_used(leaf, 0, nritems);
2484 struct btrfs_disk_key disk_key;
2486 btrfs_item_key(leaf, &disk_key, 0);
2487 wret = fixup_low_keys(trans, root, path,
2493 /* delete the leaf if it is mostly empty */
2494 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2495 /* push_leaf_left fixes the path.
2496 * make sure the path still points to our leaf
2497 * for possible call to del_ptr below
2499 slot = path->slots[1];
2500 extent_buffer_get(leaf);
2502 wret = push_leaf_left(trans, root, path, 1, 1);
2503 if (wret < 0 && wret != -ENOSPC)
2506 if (path->nodes[0] == leaf &&
2507 btrfs_header_nritems(leaf)) {
2508 wret = push_leaf_right(trans, root, path, 1, 1);
2509 if (wret < 0 && wret != -ENOSPC)
2513 if (btrfs_header_nritems(leaf) == 0) {
2515 u64 bytenr = leaf->start;
2516 u32 blocksize = leaf->len;
2518 root_gen = btrfs_header_generation(
2521 clean_tree_block(trans, root, leaf);
2522 wait_on_tree_block_writeback(root, leaf);
2524 wret = del_ptr(trans, root, path, 1, slot);
2528 free_extent_buffer(leaf);
2529 wret = btrfs_free_extent(trans, root, bytenr,
2531 btrfs_header_owner(path->nodes[1]),
2536 btrfs_mark_buffer_dirty(leaf);
2537 free_extent_buffer(leaf);
2540 btrfs_mark_buffer_dirty(leaf);
2547 * walk up the tree as far as required to find the previous leaf.
2548 * returns 0 if it found something or 1 if there are no lesser leaves.
2549 * returns < 0 on io errors.
2551 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2556 struct extent_buffer *c;
2557 struct extent_buffer *next = NULL;
2559 while(level < BTRFS_MAX_LEVEL) {
2560 if (!path->nodes[level])
2563 slot = path->slots[level];
2564 c = path->nodes[level];
2567 if (level == BTRFS_MAX_LEVEL)
2573 bytenr = btrfs_node_blockptr(c, slot);
2575 free_extent_buffer(next);
2577 next = read_tree_block(root, bytenr,
2578 btrfs_level_size(root, level - 1));
2581 path->slots[level] = slot;
2584 c = path->nodes[level];
2585 free_extent_buffer(c);
2586 slot = btrfs_header_nritems(next);
2589 path->nodes[level] = next;
2590 path->slots[level] = slot;
2593 next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2594 btrfs_level_size(root, level - 1));
2600 * walk up the tree as far as required to find the next leaf.
2601 * returns 0 if it found something or 1 if there are no greater leaves.
2602 * returns < 0 on io errors.
2604 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2609 struct extent_buffer *c;
2610 struct extent_buffer *next = NULL;
2612 while(level < BTRFS_MAX_LEVEL) {
2613 if (!path->nodes[level])
2616 slot = path->slots[level] + 1;
2617 c = path->nodes[level];
2618 if (slot >= btrfs_header_nritems(c)) {
2620 if (level == BTRFS_MAX_LEVEL)
2625 bytenr = btrfs_node_blockptr(c, slot);
2627 free_extent_buffer(next);
2630 reada_for_search(root, path, level, slot, 0);
2632 next = read_tree_block(root, bytenr,
2633 btrfs_level_size(root, level -1));
2636 path->slots[level] = slot;
2639 c = path->nodes[level];
2640 free_extent_buffer(c);
2641 path->nodes[level] = next;
2642 path->slots[level] = 0;
2646 reada_for_search(root, path, level, 0, 0);
2647 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2648 btrfs_level_size(root, level - 1));
2653 int btrfs_previous_item(struct btrfs_root *root,
2654 struct btrfs_path *path, u64 min_objectid,
2657 struct btrfs_key found_key;
2658 struct extent_buffer *leaf;
2662 if (path->slots[0] == 0) {
2663 ret = btrfs_prev_leaf(root, path);
2669 leaf = path->nodes[0];
2670 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2671 if (found_key.type == type)