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, int empty);
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;
305 u64 search_start = *last_ret;
315 int progress_passed = 0;
316 struct btrfs_disk_key disk_key;
318 parent_level = btrfs_header_level(parent);
319 if (cache_only && parent_level != 1)
322 if (trans->transaction != root->fs_info->running_transaction) {
323 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
324 root->fs_info->running_transaction->transid);
327 if (trans->transid != root->fs_info->generation) {
328 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
329 root->fs_info->generation);
333 parent_nritems = btrfs_header_nritems(parent);
334 blocksize = btrfs_level_size(root, parent_level - 1);
335 end_slot = parent_nritems;
337 if (parent_nritems == 1)
340 for (i = start_slot; i < end_slot; i++) {
343 if (!parent->map_token) {
344 map_extent_buffer(parent,
345 btrfs_node_key_ptr_offset(i),
346 sizeof(struct btrfs_key_ptr),
347 &parent->map_token, &parent->kaddr,
348 &parent->map_start, &parent->map_len,
351 btrfs_node_key(parent, &disk_key, i);
352 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
356 blocknr = btrfs_node_blockptr(parent, i);
357 gen = btrfs_node_ptr_generation(parent, i);
359 last_block = blocknr;
362 other = btrfs_node_blockptr(parent, i - 1);
363 close = close_blocks(blocknr, other, blocksize);
365 if (close && i < end_slot - 2) {
366 other = btrfs_node_blockptr(parent, i + 1);
367 close = close_blocks(blocknr, other, blocksize);
370 last_block = blocknr;
373 if (parent->map_token) {
374 unmap_extent_buffer(parent, parent->map_token,
376 parent->map_token = NULL;
379 cur = btrfs_find_tree_block(root, blocknr, blocksize);
381 uptodate = btrfs_buffer_uptodate(cur, gen);
384 if (!cur || !uptodate) {
386 free_extent_buffer(cur);
390 cur = read_tree_block(root, blocknr,
392 } else if (!uptodate) {
393 btrfs_read_buffer(cur, gen);
396 if (search_start == 0)
397 search_start = last_block;
399 err = __btrfs_cow_block(trans, root, cur, parent, i,
402 (end_slot - i) * blocksize));
404 free_extent_buffer(cur);
407 search_start = tmp->start;
408 last_block = tmp->start;
409 *last_ret = search_start;
410 if (parent_level == 1)
411 btrfs_clear_buffer_defrag(tmp);
412 free_extent_buffer(tmp);
414 if (parent->map_token) {
415 unmap_extent_buffer(parent, parent->map_token,
417 parent->map_token = NULL;
424 * The leaf data grows from end-to-front in the node.
425 * this returns the address of the start of the last item,
426 * which is the stop of the leaf data stack
428 static inline unsigned int leaf_data_end(struct btrfs_root *root,
429 struct extent_buffer *leaf)
431 u32 nr = btrfs_header_nritems(leaf);
433 return BTRFS_LEAF_DATA_SIZE(root);
434 return btrfs_item_offset_nr(leaf, nr - 1);
437 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
440 struct extent_buffer *parent = NULL;
441 struct extent_buffer *node = path->nodes[level];
442 struct btrfs_disk_key parent_key;
443 struct btrfs_disk_key node_key;
446 struct btrfs_key cpukey;
447 u32 nritems = btrfs_header_nritems(node);
449 if (path->nodes[level + 1])
450 parent = path->nodes[level + 1];
452 slot = path->slots[level];
453 BUG_ON(nritems == 0);
455 parent_slot = path->slots[level + 1];
456 btrfs_node_key(parent, &parent_key, parent_slot);
457 btrfs_node_key(node, &node_key, 0);
458 BUG_ON(memcmp(&parent_key, &node_key,
459 sizeof(struct btrfs_disk_key)));
460 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
461 btrfs_header_bytenr(node));
463 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
465 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
466 btrfs_node_key(node, &node_key, slot);
467 BUG_ON(btrfs_comp_keys(&node_key, &cpukey) <= 0);
469 if (slot < nritems - 1) {
470 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
471 btrfs_node_key(node, &node_key, slot);
472 BUG_ON(btrfs_comp_keys(&node_key, &cpukey) >= 0);
477 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
480 struct extent_buffer *leaf = path->nodes[level];
481 struct extent_buffer *parent = NULL;
483 struct btrfs_key cpukey;
484 struct btrfs_disk_key parent_key;
485 struct btrfs_disk_key leaf_key;
486 int slot = path->slots[0];
488 u32 nritems = btrfs_header_nritems(leaf);
490 if (path->nodes[level + 1])
491 parent = path->nodes[level + 1];
497 parent_slot = path->slots[level + 1];
498 btrfs_node_key(parent, &parent_key, parent_slot);
499 btrfs_item_key(leaf, &leaf_key, 0);
501 BUG_ON(memcmp(&parent_key, &leaf_key,
502 sizeof(struct btrfs_disk_key)));
503 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
504 btrfs_header_bytenr(leaf));
507 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
508 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
509 btrfs_item_key(leaf, &leaf_key, i);
510 if (comp_keys(&leaf_key, &cpukey) >= 0) {
511 btrfs_print_leaf(root, leaf);
512 printk("slot %d offset bad key\n", i);
515 if (btrfs_item_offset_nr(leaf, i) !=
516 btrfs_item_end_nr(leaf, i + 1)) {
517 btrfs_print_leaf(root, leaf);
518 printk("slot %d offset bad\n", i);
522 if (btrfs_item_offset_nr(leaf, i) +
523 btrfs_item_size_nr(leaf, i) !=
524 BTRFS_LEAF_DATA_SIZE(root)) {
525 btrfs_print_leaf(root, leaf);
526 printk("slot %d first offset bad\n", i);
532 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
533 btrfs_print_leaf(root, leaf);
534 printk("slot %d bad size \n", nritems - 1);
539 if (slot != 0 && slot < nritems - 1) {
540 btrfs_item_key(leaf, &leaf_key, slot);
541 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
542 if (btrfs_comp_keys(&leaf_key, &cpukey) <= 0) {
543 btrfs_print_leaf(root, leaf);
544 printk("slot %d offset bad key\n", slot);
547 if (btrfs_item_offset_nr(leaf, slot - 1) !=
548 btrfs_item_end_nr(leaf, slot)) {
549 btrfs_print_leaf(root, leaf);
550 printk("slot %d offset bad\n", slot);
554 if (slot < nritems - 1) {
555 btrfs_item_key(leaf, &leaf_key, slot);
556 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
557 BUG_ON(btrfs_comp_keys(&leaf_key, &cpukey) >= 0);
558 if (btrfs_item_offset_nr(leaf, slot) !=
559 btrfs_item_end_nr(leaf, slot + 1)) {
560 btrfs_print_leaf(root, leaf);
561 printk("slot %d offset bad\n", slot);
565 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
566 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
570 static int noinline check_block(struct btrfs_root *root,
571 struct btrfs_path *path, int level)
575 struct extent_buffer *buf = path->nodes[level];
577 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
578 (unsigned long)btrfs_header_fsid(buf),
580 printk("warning bad block %Lu\n", buf->start);
585 return check_leaf(root, path, level);
586 return check_node(root, path, level);
590 * search for key in the extent_buffer. The items start at offset p,
591 * and they are item_size apart. There are 'max' items in p.
593 * the slot in the array is returned via slot, and it points to
594 * the place where you would insert key if it is not found in
597 * slot may point to max if the key is bigger than all of the keys
599 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
600 int item_size, struct btrfs_key *key,
607 unsigned long offset;
608 struct btrfs_disk_key *tmp;
611 mid = (low + high) / 2;
612 offset = p + mid * item_size;
614 tmp = (struct btrfs_disk_key *)(eb->data + offset);
615 ret = btrfs_comp_keys(tmp, key);
631 * simple bin_search frontend that does the right thing for
634 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
635 int level, int *slot)
638 return generic_bin_search(eb,
639 offsetof(struct btrfs_leaf, items),
640 sizeof(struct btrfs_item),
641 key, btrfs_header_nritems(eb),
644 return generic_bin_search(eb,
645 offsetof(struct btrfs_node, ptrs),
646 sizeof(struct btrfs_key_ptr),
647 key, btrfs_header_nritems(eb),
653 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
654 struct extent_buffer *parent, int slot)
656 int level = btrfs_header_level(parent);
659 if (slot >= btrfs_header_nritems(parent))
664 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
665 btrfs_level_size(root, level - 1),
666 btrfs_node_ptr_generation(parent, slot));
669 static int balance_level(struct btrfs_trans_handle *trans,
670 struct btrfs_root *root,
671 struct btrfs_path *path, int level)
673 struct extent_buffer *right = NULL;
674 struct extent_buffer *mid;
675 struct extent_buffer *left = NULL;
676 struct extent_buffer *parent = NULL;
680 int orig_slot = path->slots[level];
681 int err_on_enospc = 0;
687 mid = path->nodes[level];
688 WARN_ON(btrfs_header_generation(mid) != trans->transid);
690 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
692 if (level < BTRFS_MAX_LEVEL - 1)
693 parent = path->nodes[level + 1];
694 pslot = path->slots[level + 1];
697 * deal with the case where there is only one pointer in the root
698 * by promoting the node below to a root
701 struct extent_buffer *child;
703 if (btrfs_header_nritems(mid) != 1)
706 /* promote the child to a root */
707 child = read_node_slot(root, mid, 0);
709 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
713 add_root_to_dirty_list(root);
714 path->nodes[level] = NULL;
715 clean_tree_block(trans, root, mid);
716 wait_on_tree_block_writeback(root, mid);
717 /* once for the path */
718 free_extent_buffer(mid);
719 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
720 root->root_key.objectid,
721 btrfs_header_generation(mid), 0, 0, 1);
722 /* once for the root ptr */
723 free_extent_buffer(mid);
726 if (btrfs_header_nritems(mid) >
727 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
730 if (btrfs_header_nritems(mid) < 2)
733 left = read_node_slot(root, parent, pslot - 1);
735 wret = btrfs_cow_block(trans, root, left,
736 parent, pslot - 1, &left);
742 right = read_node_slot(root, parent, pslot + 1);
744 wret = btrfs_cow_block(trans, root, right,
745 parent, pslot + 1, &right);
752 /* first, try to make some room in the middle buffer */
754 orig_slot += btrfs_header_nritems(left);
755 wret = push_node_left(trans, root, left, mid, 1);
758 if (btrfs_header_nritems(mid) < 2)
763 * then try to empty the right most buffer into the middle
766 wret = push_node_left(trans, root, mid, right, 1);
767 if (wret < 0 && wret != -ENOSPC)
769 if (btrfs_header_nritems(right) == 0) {
770 u64 bytenr = right->start;
771 u64 generation = btrfs_header_generation(parent);
772 u32 blocksize = right->len;
774 clean_tree_block(trans, root, right);
775 wait_on_tree_block_writeback(root, right);
776 free_extent_buffer(right);
778 wret = del_ptr(trans, root, path, level + 1, pslot +
782 wret = btrfs_free_extent(trans, root, bytenr,
784 btrfs_header_owner(parent),
785 generation, 0, 0, 1);
789 struct btrfs_disk_key right_key;
790 btrfs_node_key(right, &right_key, 0);
791 btrfs_set_node_key(parent, &right_key, pslot + 1);
792 btrfs_mark_buffer_dirty(parent);
795 if (btrfs_header_nritems(mid) == 1) {
797 * we're not allowed to leave a node with one item in the
798 * tree during a delete. A deletion from lower in the tree
799 * could try to delete the only pointer in this node.
800 * So, pull some keys from the left.
801 * There has to be a left pointer at this point because
802 * otherwise we would have pulled some pointers from the
806 wret = balance_node_right(trans, root, mid, left);
812 wret = push_node_left(trans, root, left, mid, 1);
818 if (btrfs_header_nritems(mid) == 0) {
819 /* we've managed to empty the middle node, drop it */
820 u64 root_gen = btrfs_header_generation(parent);
821 u64 bytenr = mid->start;
822 u32 blocksize = mid->len;
823 clean_tree_block(trans, root, mid);
824 wait_on_tree_block_writeback(root, mid);
825 free_extent_buffer(mid);
827 wret = del_ptr(trans, root, path, level + 1, pslot);
830 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
831 btrfs_header_owner(parent),
836 /* update the parent key to reflect our changes */
837 struct btrfs_disk_key mid_key;
838 btrfs_node_key(mid, &mid_key, 0);
839 btrfs_set_node_key(parent, &mid_key, pslot);
840 btrfs_mark_buffer_dirty(parent);
843 /* update the path */
845 if (btrfs_header_nritems(left) > orig_slot) {
846 extent_buffer_get(left);
847 path->nodes[level] = left;
848 path->slots[level + 1] -= 1;
849 path->slots[level] = orig_slot;
851 free_extent_buffer(mid);
853 orig_slot -= btrfs_header_nritems(left);
854 path->slots[level] = orig_slot;
857 /* double check we haven't messed things up */
858 check_block(root, path, level);
860 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
864 free_extent_buffer(right);
866 free_extent_buffer(left);
870 /* returns zero if the push worked, non-zero otherwise */
871 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
872 struct btrfs_root *root,
873 struct btrfs_path *path, int level)
875 struct extent_buffer *right = NULL;
876 struct extent_buffer *mid;
877 struct extent_buffer *left = NULL;
878 struct extent_buffer *parent = NULL;
882 int orig_slot = path->slots[level];
888 mid = path->nodes[level];
889 WARN_ON(btrfs_header_generation(mid) != trans->transid);
890 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
892 if (level < BTRFS_MAX_LEVEL - 1)
893 parent = path->nodes[level + 1];
894 pslot = path->slots[level + 1];
899 left = read_node_slot(root, parent, pslot - 1);
901 /* first, try to make some room in the middle buffer */
904 left_nr = btrfs_header_nritems(left);
905 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
908 ret = btrfs_cow_block(trans, root, left, parent,
913 wret = push_node_left(trans, root,
920 struct btrfs_disk_key disk_key;
921 orig_slot += left_nr;
922 btrfs_node_key(mid, &disk_key, 0);
923 btrfs_set_node_key(parent, &disk_key, pslot);
924 btrfs_mark_buffer_dirty(parent);
925 if (btrfs_header_nritems(left) > orig_slot) {
926 path->nodes[level] = left;
927 path->slots[level + 1] -= 1;
928 path->slots[level] = orig_slot;
929 free_extent_buffer(mid);
932 btrfs_header_nritems(left);
933 path->slots[level] = orig_slot;
934 free_extent_buffer(left);
938 free_extent_buffer(left);
940 right= read_node_slot(root, parent, pslot + 1);
943 * then try to empty the right most buffer into the middle
947 right_nr = btrfs_header_nritems(right);
948 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
951 ret = btrfs_cow_block(trans, root, right,
957 wret = balance_node_right(trans, root,
964 struct btrfs_disk_key disk_key;
966 btrfs_node_key(right, &disk_key, 0);
967 btrfs_set_node_key(parent, &disk_key, pslot + 1);
968 btrfs_mark_buffer_dirty(parent);
970 if (btrfs_header_nritems(mid) <= orig_slot) {
971 path->nodes[level] = right;
972 path->slots[level + 1] += 1;
973 path->slots[level] = orig_slot -
974 btrfs_header_nritems(mid);
975 free_extent_buffer(mid);
977 free_extent_buffer(right);
981 free_extent_buffer(right);
987 * readahead one full node of leaves
989 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
990 int level, int slot, u64 objectid)
992 struct extent_buffer *node;
993 struct btrfs_disk_key disk_key;
999 int direction = path->reada;
1000 struct extent_buffer *eb;
1008 if (!path->nodes[level])
1011 node = path->nodes[level];
1012 search = btrfs_node_blockptr(node, slot);
1013 blocksize = btrfs_level_size(root, level - 1);
1014 eb = btrfs_find_tree_block(root, search, blocksize);
1016 free_extent_buffer(eb);
1020 highest_read = search;
1021 lowest_read = search;
1023 nritems = btrfs_header_nritems(node);
1026 if (direction < 0) {
1030 } else if (direction > 0) {
1035 if (path->reada < 0 && objectid) {
1036 btrfs_node_key(node, &disk_key, nr);
1037 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1040 search = btrfs_node_blockptr(node, nr);
1041 if ((search >= lowest_read && search <= highest_read) ||
1042 (search < lowest_read && lowest_read - search <= 32768) ||
1043 (search > highest_read && search - highest_read <= 32768)) {
1044 readahead_tree_block(root, search, blocksize,
1045 btrfs_node_ptr_generation(node, nr));
1049 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1051 if(nread > (1024 * 1024) || nscan > 128)
1054 if (search < lowest_read)
1055 lowest_read = search;
1056 if (search > highest_read)
1057 highest_read = search;
1062 * look for key in the tree. path is filled in with nodes along the way
1063 * if key is found, we return zero and you can find the item in the leaf
1064 * level of the path (level 0)
1066 * If the key isn't found, the path points to the slot where it should
1067 * be inserted, and 1 is returned. If there are other errors during the
1068 * search a negative error number is returned.
1070 * if ins_len > 0, nodes and leaves will be split as we walk down the
1071 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1074 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1075 *root, struct btrfs_key *key, struct btrfs_path *p, int
1078 struct extent_buffer *b;
1082 int should_reada = p->reada;
1083 u8 lowest_level = 0;
1085 lowest_level = p->lowest_level;
1086 WARN_ON(lowest_level && ins_len);
1087 WARN_ON(p->nodes[0] != NULL);
1089 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1093 extent_buffer_get(b);
1095 level = btrfs_header_level(b);
1098 wret = btrfs_cow_block(trans, root, b,
1099 p->nodes[level + 1],
1100 p->slots[level + 1],
1103 free_extent_buffer(b);
1107 BUG_ON(!cow && ins_len);
1108 if (level != btrfs_header_level(b))
1110 level = btrfs_header_level(b);
1111 p->nodes[level] = b;
1112 ret = check_block(root, p, level);
1115 ret = bin_search(b, key, level, &slot);
1117 if (ret && slot > 0)
1119 p->slots[level] = slot;
1120 if (ins_len > 0 && btrfs_header_nritems(b) >=
1121 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1122 int sret = split_node(trans, root, p, level);
1126 b = p->nodes[level];
1127 slot = p->slots[level];
1128 } else if (ins_len < 0) {
1129 int sret = balance_level(trans, root, p,
1133 b = p->nodes[level];
1135 btrfs_release_path(NULL, p);
1138 slot = p->slots[level];
1139 BUG_ON(btrfs_header_nritems(b) == 1);
1141 /* this is only true while dropping a snapshot */
1142 if (level == lowest_level)
1146 reada_for_search(root, p, level, slot,
1149 b = read_node_slot(root, b, slot);
1151 p->slots[level] = slot;
1152 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1153 sizeof(struct btrfs_item) + ins_len) {
1154 int sret = split_leaf(trans, root, key,
1155 p, ins_len, ret == 0);
1167 * adjust the pointers going up the tree, starting at level
1168 * making sure the right key of each node is points to 'key'.
1169 * This is used after shifting pointers to the left, so it stops
1170 * fixing up pointers when a given leaf/node is not in slot 0 of the
1173 * If this fails to write a tree block, it returns -1, but continues
1174 * fixing up the blocks in ram so the tree is consistent.
1176 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1177 struct btrfs_root *root, struct btrfs_path *path,
1178 struct btrfs_disk_key *key, int level)
1182 struct extent_buffer *t;
1184 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1185 int tslot = path->slots[i];
1186 if (!path->nodes[i])
1189 btrfs_set_node_key(t, key, tslot);
1190 btrfs_mark_buffer_dirty(path->nodes[i]);
1198 * try to push data from one node into the next node left in the
1201 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1202 * error, and > 0 if there was no room in the left hand block.
1204 static int push_node_left(struct btrfs_trans_handle *trans,
1205 struct btrfs_root *root, struct extent_buffer *dst,
1206 struct extent_buffer *src, int empty)
1213 src_nritems = btrfs_header_nritems(src);
1214 dst_nritems = btrfs_header_nritems(dst);
1215 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1216 WARN_ON(btrfs_header_generation(src) != trans->transid);
1217 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1219 if (!empty && src_nritems <= 8)
1222 if (push_items <= 0) {
1227 push_items = min(src_nritems, push_items);
1228 if (push_items < src_nritems) {
1229 /* leave at least 8 pointers in the node if
1230 * we aren't going to empty it
1232 if (src_nritems - push_items < 8) {
1233 if (push_items <= 8)
1239 push_items = min(src_nritems - 8, push_items);
1241 copy_extent_buffer(dst, src,
1242 btrfs_node_key_ptr_offset(dst_nritems),
1243 btrfs_node_key_ptr_offset(0),
1244 push_items * sizeof(struct btrfs_key_ptr));
1246 if (push_items < src_nritems) {
1247 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1248 btrfs_node_key_ptr_offset(push_items),
1249 (src_nritems - push_items) *
1250 sizeof(struct btrfs_key_ptr));
1252 btrfs_set_header_nritems(src, src_nritems - push_items);
1253 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1254 btrfs_mark_buffer_dirty(src);
1255 btrfs_mark_buffer_dirty(dst);
1260 * try to push data from one node into the next node right in the
1263 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1264 * error, and > 0 if there was no room in the right hand block.
1266 * this will only push up to 1/2 the contents of the left node over
1268 static int balance_node_right(struct btrfs_trans_handle *trans,
1269 struct btrfs_root *root,
1270 struct extent_buffer *dst,
1271 struct extent_buffer *src)
1279 WARN_ON(btrfs_header_generation(src) != trans->transid);
1280 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1282 src_nritems = btrfs_header_nritems(src);
1283 dst_nritems = btrfs_header_nritems(dst);
1284 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1285 if (push_items <= 0) {
1289 if (src_nritems < 4) {
1293 max_push = src_nritems / 2 + 1;
1294 /* don't try to empty the node */
1295 if (max_push >= src_nritems) {
1299 if (max_push < push_items)
1300 push_items = max_push;
1302 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1303 btrfs_node_key_ptr_offset(0),
1305 sizeof(struct btrfs_key_ptr));
1307 copy_extent_buffer(dst, src,
1308 btrfs_node_key_ptr_offset(0),
1309 btrfs_node_key_ptr_offset(src_nritems - push_items),
1310 push_items * sizeof(struct btrfs_key_ptr));
1312 btrfs_set_header_nritems(src, src_nritems - push_items);
1313 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1315 btrfs_mark_buffer_dirty(src);
1316 btrfs_mark_buffer_dirty(dst);
1321 * helper function to insert a new root level in the tree.
1322 * A new node is allocated, and a single item is inserted to
1323 * point to the existing root
1325 * returns zero on success or < 0 on failure.
1327 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1328 struct btrfs_root *root,
1329 struct btrfs_path *path, int level)
1333 struct extent_buffer *lower;
1334 struct extent_buffer *c;
1335 struct btrfs_disk_key lower_key;
1337 BUG_ON(path->nodes[level]);
1338 BUG_ON(path->nodes[level-1] != root->node);
1341 root_gen = trans->transid;
1345 lower = path->nodes[level-1];
1347 btrfs_item_key(lower, &lower_key, 0);
1349 btrfs_node_key(lower, &lower_key, 0);
1351 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1352 root->root_key.objectid,
1353 root_gen, lower_key.objectid, level,
1354 root->node->start, 0);
1357 memset_extent_buffer(c, 0, 0, root->nodesize);
1358 btrfs_set_header_nritems(c, 1);
1359 btrfs_set_header_level(c, level);
1360 btrfs_set_header_bytenr(c, c->start);
1361 btrfs_set_header_generation(c, trans->transid);
1362 btrfs_set_header_owner(c, root->root_key.objectid);
1364 write_extent_buffer(c, root->fs_info->fsid,
1365 (unsigned long)btrfs_header_fsid(c),
1368 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1369 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1372 btrfs_set_node_key(c, &lower_key, 0);
1373 btrfs_set_node_blockptr(c, 0, lower->start);
1374 lower_gen = btrfs_header_generation(lower);
1375 WARN_ON(lower_gen == 0);
1377 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1379 btrfs_mark_buffer_dirty(c);
1381 /* the super has an extra ref to root->node */
1382 free_extent_buffer(root->node);
1384 add_root_to_dirty_list(root);
1385 extent_buffer_get(c);
1386 path->nodes[level] = c;
1387 path->slots[level] = 0;
1389 if (root->ref_cows && lower_gen != trans->transid) {
1390 struct btrfs_path *back_path = btrfs_alloc_path();
1392 ret = btrfs_insert_extent_backref(trans,
1393 root->fs_info->extent_root,
1395 root->root_key.objectid,
1396 trans->transid, 0, 0);
1398 btrfs_free_path(back_path);
1404 * worker function to insert a single pointer in a node.
1405 * the node should have enough room for the pointer already
1407 * slot and level indicate where you want the key to go, and
1408 * blocknr is the block the key points to.
1410 * returns zero on success and < 0 on any error
1412 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1413 *root, struct btrfs_path *path, struct btrfs_disk_key
1414 *key, u64 bytenr, int slot, int level)
1416 struct extent_buffer *lower;
1419 BUG_ON(!path->nodes[level]);
1420 lower = path->nodes[level];
1421 nritems = btrfs_header_nritems(lower);
1424 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1426 if (slot != nritems) {
1427 memmove_extent_buffer(lower,
1428 btrfs_node_key_ptr_offset(slot + 1),
1429 btrfs_node_key_ptr_offset(slot),
1430 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1432 btrfs_set_node_key(lower, key, slot);
1433 btrfs_set_node_blockptr(lower, slot, bytenr);
1434 WARN_ON(trans->transid == 0);
1435 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1436 btrfs_set_header_nritems(lower, nritems + 1);
1437 btrfs_mark_buffer_dirty(lower);
1442 * split the node at the specified level in path in two.
1443 * The path is corrected to point to the appropriate node after the split
1445 * Before splitting this tries to make some room in the node by pushing
1446 * left and right, if either one works, it returns right away.
1448 * returns 0 on success and < 0 on failure
1450 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1451 *root, struct btrfs_path *path, int level)
1454 struct extent_buffer *c;
1455 struct extent_buffer *split;
1456 struct btrfs_disk_key disk_key;
1462 c = path->nodes[level];
1463 WARN_ON(btrfs_header_generation(c) != trans->transid);
1464 if (c == root->node) {
1465 /* trying to split the root, lets make a new one */
1466 ret = insert_new_root(trans, root, path, level + 1);
1470 ret = push_nodes_for_insert(trans, root, path, level);
1471 c = path->nodes[level];
1472 if (!ret && btrfs_header_nritems(c) <
1473 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1479 c_nritems = btrfs_header_nritems(c);
1481 root_gen = trans->transid;
1485 btrfs_node_key(c, &disk_key, 0);
1486 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1487 root->root_key.objectid,
1489 btrfs_disk_key_objectid(&disk_key),
1490 level, c->start, 0);
1492 return PTR_ERR(split);
1494 btrfs_set_header_flags(split, btrfs_header_flags(c));
1495 btrfs_set_header_level(split, btrfs_header_level(c));
1496 btrfs_set_header_bytenr(split, split->start);
1497 btrfs_set_header_generation(split, trans->transid);
1498 btrfs_set_header_owner(split, root->root_key.objectid);
1499 btrfs_set_header_flags(split, 0);
1500 write_extent_buffer(split, root->fs_info->fsid,
1501 (unsigned long)btrfs_header_fsid(split),
1503 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1504 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1507 mid = (c_nritems + 1) / 2;
1509 copy_extent_buffer(split, c,
1510 btrfs_node_key_ptr_offset(0),
1511 btrfs_node_key_ptr_offset(mid),
1512 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1513 btrfs_set_header_nritems(split, c_nritems - mid);
1514 btrfs_set_header_nritems(c, mid);
1517 btrfs_mark_buffer_dirty(c);
1518 btrfs_mark_buffer_dirty(split);
1520 btrfs_node_key(split, &disk_key, 0);
1521 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1522 path->slots[level + 1] + 1,
1527 if (path->slots[level] >= mid) {
1528 path->slots[level] -= mid;
1529 free_extent_buffer(c);
1530 path->nodes[level] = split;
1531 path->slots[level + 1] += 1;
1533 free_extent_buffer(split);
1539 * how many bytes are required to store the items in a leaf. start
1540 * and nr indicate which items in the leaf to check. This totals up the
1541 * space used both by the item structs and the item data
1543 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1546 int nritems = btrfs_header_nritems(l);
1547 int end = min(nritems, start + nr) - 1;
1551 data_len = btrfs_item_end_nr(l, start);
1552 data_len = data_len - btrfs_item_offset_nr(l, end);
1553 data_len += sizeof(struct btrfs_item) * nr;
1554 WARN_ON(data_len < 0);
1559 * The space between the end of the leaf items and
1560 * the start of the leaf data. IOW, how much room
1561 * the leaf has left for both items and data
1563 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1565 int nritems = btrfs_header_nritems(leaf);
1567 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1569 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1570 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1571 leaf_space_used(leaf, 0, nritems), nritems);
1577 * push some data in the path leaf to the right, trying to free up at
1578 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1580 * returns 1 if the push failed because the other node didn't have enough
1581 * room, 0 if everything worked out and < 0 if there were major errors.
1583 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1584 *root, struct btrfs_path *path, int data_size,
1587 struct extent_buffer *left = path->nodes[0];
1588 struct extent_buffer *right;
1589 struct extent_buffer *upper;
1590 struct btrfs_disk_key disk_key;
1596 struct btrfs_item *item;
1604 slot = path->slots[1];
1605 if (!path->nodes[1]) {
1608 upper = path->nodes[1];
1609 if (slot >= btrfs_header_nritems(upper) - 1)
1612 right = read_node_slot(root, upper, slot + 1);
1613 free_space = btrfs_leaf_free_space(root, right);
1614 if (free_space < data_size + sizeof(struct btrfs_item)) {
1615 free_extent_buffer(right);
1619 /* cow and double check */
1620 ret = btrfs_cow_block(trans, root, right, upper,
1623 free_extent_buffer(right);
1626 free_space = btrfs_leaf_free_space(root, right);
1627 if (free_space < data_size + sizeof(struct btrfs_item)) {
1628 free_extent_buffer(right);
1632 left_nritems = btrfs_header_nritems(left);
1633 if (left_nritems == 0) {
1634 free_extent_buffer(right);
1643 i = left_nritems - 1;
1645 item = btrfs_item_nr(left, i);
1647 if (path->slots[0] == i)
1648 push_space += data_size + sizeof(*item);
1650 this_item_size = btrfs_item_size(left, item);
1651 if (this_item_size + sizeof(*item) + push_space > free_space)
1654 push_space += this_item_size + sizeof(*item);
1660 if (push_items == 0) {
1661 free_extent_buffer(right);
1665 if (!empty && push_items == left_nritems)
1668 /* push left to right */
1669 right_nritems = btrfs_header_nritems(right);
1671 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1672 push_space -= leaf_data_end(root, left);
1674 /* make room in the right data area */
1675 data_end = leaf_data_end(root, right);
1676 memmove_extent_buffer(right,
1677 btrfs_leaf_data(right) + data_end - push_space,
1678 btrfs_leaf_data(right) + data_end,
1679 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1681 /* copy from the left data area */
1682 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1683 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1684 btrfs_leaf_data(left) + leaf_data_end(root, left),
1687 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1688 btrfs_item_nr_offset(0),
1689 right_nritems * sizeof(struct btrfs_item));
1691 /* copy the items from left to right */
1692 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1693 btrfs_item_nr_offset(left_nritems - push_items),
1694 push_items * sizeof(struct btrfs_item));
1696 /* update the item pointers */
1697 right_nritems += push_items;
1698 btrfs_set_header_nritems(right, right_nritems);
1699 push_space = BTRFS_LEAF_DATA_SIZE(root);
1700 for (i = 0; i < right_nritems; i++) {
1701 item = btrfs_item_nr(right, i);
1702 push_space -= btrfs_item_size(right, item);
1703 btrfs_set_item_offset(right, item, push_space);
1706 left_nritems -= push_items;
1707 btrfs_set_header_nritems(left, left_nritems);
1710 btrfs_mark_buffer_dirty(left);
1711 btrfs_mark_buffer_dirty(right);
1713 btrfs_item_key(right, &disk_key, 0);
1714 btrfs_set_node_key(upper, &disk_key, slot + 1);
1715 btrfs_mark_buffer_dirty(upper);
1717 /* then fixup the leaf pointer in the path */
1718 if (path->slots[0] >= left_nritems) {
1719 path->slots[0] -= left_nritems;
1720 free_extent_buffer(path->nodes[0]);
1721 path->nodes[0] = right;
1722 path->slots[1] += 1;
1724 free_extent_buffer(right);
1729 * push some data in the path leaf to the left, trying to free up at
1730 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1732 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1733 *root, struct btrfs_path *path, int data_size,
1736 struct btrfs_disk_key disk_key;
1737 struct extent_buffer *right = path->nodes[0];
1738 struct extent_buffer *left;
1744 struct btrfs_item *item;
1745 u32 old_left_nritems;
1751 u32 old_left_item_size;
1753 slot = path->slots[1];
1756 if (!path->nodes[1])
1759 right_nritems = btrfs_header_nritems(right);
1760 if (right_nritems == 0) {
1764 left = read_node_slot(root, path->nodes[1], slot - 1);
1765 free_space = btrfs_leaf_free_space(root, left);
1766 if (free_space < data_size + sizeof(struct btrfs_item)) {
1767 free_extent_buffer(left);
1771 /* cow and double check */
1772 ret = btrfs_cow_block(trans, root, left,
1773 path->nodes[1], slot - 1, &left);
1775 /* we hit -ENOSPC, but it isn't fatal here */
1776 free_extent_buffer(left);
1780 free_space = btrfs_leaf_free_space(root, left);
1781 if (free_space < data_size + sizeof(struct btrfs_item)) {
1782 free_extent_buffer(left);
1789 nr = right_nritems - 1;
1791 for (i = 0; i < nr; i++) {
1792 item = btrfs_item_nr(right, i);
1794 if (path->slots[0] == i)
1795 push_space += data_size + sizeof(*item);
1797 this_item_size = btrfs_item_size(right, item);
1798 if (this_item_size + sizeof(*item) + push_space > free_space)
1802 push_space += this_item_size + sizeof(*item);
1805 if (push_items == 0) {
1806 free_extent_buffer(left);
1809 if (!empty && push_items == btrfs_header_nritems(right))
1812 /* push data from right to left */
1813 copy_extent_buffer(left, right,
1814 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1815 btrfs_item_nr_offset(0),
1816 push_items * sizeof(struct btrfs_item));
1818 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1819 btrfs_item_offset_nr(right, push_items -1);
1821 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1822 leaf_data_end(root, left) - push_space,
1823 btrfs_leaf_data(right) +
1824 btrfs_item_offset_nr(right, push_items - 1),
1826 old_left_nritems = btrfs_header_nritems(left);
1827 BUG_ON(old_left_nritems < 0);
1829 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1830 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1833 item = btrfs_item_nr(left, i);
1834 ioff = btrfs_item_offset(left, item);
1835 btrfs_set_item_offset(left, item,
1836 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1838 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1840 /* fixup right node */
1841 if (push_items > right_nritems) {
1842 printk("push items %d nr %u\n", push_items, right_nritems);
1846 if (push_items < right_nritems) {
1847 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1848 leaf_data_end(root, right);
1849 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1850 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1851 btrfs_leaf_data(right) +
1852 leaf_data_end(root, right), push_space);
1854 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1855 btrfs_item_nr_offset(push_items),
1856 (btrfs_header_nritems(right) - push_items) *
1857 sizeof(struct btrfs_item));
1859 right_nritems -= push_items;
1860 btrfs_set_header_nritems(right, right_nritems);
1861 push_space = BTRFS_LEAF_DATA_SIZE(root);
1862 for (i = 0; i < right_nritems; i++) {
1863 item = btrfs_item_nr(right, i);
1864 push_space = push_space - btrfs_item_size(right, item);
1865 btrfs_set_item_offset(right, item, push_space);
1868 btrfs_mark_buffer_dirty(left);
1870 btrfs_mark_buffer_dirty(right);
1872 btrfs_item_key(right, &disk_key, 0);
1873 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1877 /* then fixup the leaf pointer in the path */
1878 if (path->slots[0] < push_items) {
1879 path->slots[0] += old_left_nritems;
1880 free_extent_buffer(path->nodes[0]);
1881 path->nodes[0] = left;
1882 path->slots[1] -= 1;
1884 free_extent_buffer(left);
1885 path->slots[0] -= push_items;
1887 BUG_ON(path->slots[0] < 0);
1892 * split the path's leaf in two, making sure there is at least data_size
1893 * available for the resulting leaf level of the path.
1895 * returns 0 if all went well and < 0 on failure.
1897 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1898 *root, struct btrfs_key *ins_key,
1899 struct btrfs_path *path, int data_size, int extend)
1902 struct extent_buffer *l;
1906 struct extent_buffer *right;
1907 int space_needed = data_size + sizeof(struct btrfs_item);
1914 int num_doubles = 0;
1915 struct btrfs_disk_key disk_key;
1918 space_needed = data_size;
1921 root_gen = trans->transid;
1925 /* first try to make some room by pushing left and right */
1926 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1927 wret = push_leaf_right(trans, root, path, data_size, 0);
1932 wret = push_leaf_left(trans, root, path, data_size, 0);
1938 /* did the pushes work? */
1939 if (btrfs_leaf_free_space(root, l) >= space_needed)
1943 if (!path->nodes[1]) {
1944 ret = insert_new_root(trans, root, path, 1);
1951 slot = path->slots[0];
1952 nritems = btrfs_header_nritems(l);
1953 mid = (nritems + 1)/ 2;
1955 btrfs_item_key(l, &disk_key, 0);
1957 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
1958 root->root_key.objectid,
1959 root_gen, disk_key.objectid, 0,
1961 if (IS_ERR(right)) {
1963 return PTR_ERR(right);
1966 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
1967 btrfs_set_header_bytenr(right, right->start);
1968 btrfs_set_header_generation(right, trans->transid);
1969 btrfs_set_header_owner(right, root->root_key.objectid);
1970 btrfs_set_header_level(right, 0);
1971 write_extent_buffer(right, root->fs_info->fsid,
1972 (unsigned long)btrfs_header_fsid(right),
1975 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
1976 (unsigned long)btrfs_header_chunk_tree_uuid(right),
1980 leaf_space_used(l, mid, nritems - mid) + space_needed >
1981 BTRFS_LEAF_DATA_SIZE(root)) {
1982 if (slot >= nritems) {
1983 btrfs_cpu_key_to_disk(&disk_key, ins_key);
1984 btrfs_set_header_nritems(right, 0);
1985 wret = insert_ptr(trans, root, path,
1986 &disk_key, right->start,
1987 path->slots[1] + 1, 1);
1990 free_extent_buffer(path->nodes[0]);
1991 path->nodes[0] = right;
1993 path->slots[1] += 1;
1997 if (mid != nritems &&
1998 leaf_space_used(l, mid, nritems - mid) +
1999 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2004 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2005 BTRFS_LEAF_DATA_SIZE(root)) {
2006 if (!extend && slot == 0) {
2007 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2008 btrfs_set_header_nritems(right, 0);
2009 wret = insert_ptr(trans, root, path,
2015 free_extent_buffer(path->nodes[0]);
2016 path->nodes[0] = right;
2018 if (path->slots[1] == 0) {
2019 wret = fixup_low_keys(trans, root,
2020 path, &disk_key, 1);
2025 } else if (extend && slot == 0) {
2029 if (mid != nritems &&
2030 leaf_space_used(l, mid, nritems - mid) +
2031 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2037 nritems = nritems - mid;
2038 btrfs_set_header_nritems(right, nritems);
2039 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2041 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2042 btrfs_item_nr_offset(mid),
2043 nritems * sizeof(struct btrfs_item));
2045 copy_extent_buffer(right, l,
2046 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2047 data_copy_size, btrfs_leaf_data(l) +
2048 leaf_data_end(root, l), data_copy_size);
2050 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2051 btrfs_item_end_nr(l, mid);
2053 for (i = 0; i < nritems; i++) {
2054 struct btrfs_item *item = btrfs_item_nr(right, i);
2055 u32 ioff = btrfs_item_offset(right, item);
2056 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2059 btrfs_set_header_nritems(l, mid);
2061 btrfs_item_key(right, &disk_key, 0);
2062 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2063 path->slots[1] + 1, 1);
2067 btrfs_mark_buffer_dirty(right);
2068 btrfs_mark_buffer_dirty(l);
2069 BUG_ON(path->slots[0] != slot);
2072 free_extent_buffer(path->nodes[0]);
2073 path->nodes[0] = right;
2074 path->slots[0] -= mid;
2075 path->slots[1] += 1;
2077 free_extent_buffer(right);
2079 BUG_ON(path->slots[0] < 0);
2082 BUG_ON(num_doubles != 0);
2089 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2090 struct btrfs_root *root,
2091 struct btrfs_path *path,
2092 u32 new_size, int from_end)
2097 struct extent_buffer *leaf;
2098 struct btrfs_item *item;
2100 unsigned int data_end;
2101 unsigned int old_data_start;
2102 unsigned int old_size;
2103 unsigned int size_diff;
2106 slot_orig = path->slots[0];
2107 leaf = path->nodes[0];
2108 slot = path->slots[0];
2110 old_size = btrfs_item_size_nr(leaf, slot);
2111 if (old_size == new_size)
2114 nritems = btrfs_header_nritems(leaf);
2115 data_end = leaf_data_end(root, leaf);
2117 old_data_start = btrfs_item_offset_nr(leaf, slot);
2119 size_diff = old_size - new_size;
2122 BUG_ON(slot >= nritems);
2125 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2127 /* first correct the data pointers */
2128 for (i = slot; i < nritems; i++) {
2130 item = btrfs_item_nr(leaf, i);
2131 ioff = btrfs_item_offset(leaf, item);
2132 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2135 /* shift the data */
2137 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2138 data_end + size_diff, btrfs_leaf_data(leaf) +
2139 data_end, old_data_start + new_size - data_end);
2141 struct btrfs_disk_key disk_key;
2144 btrfs_item_key(leaf, &disk_key, slot);
2146 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2148 struct btrfs_file_extent_item *fi;
2150 fi = btrfs_item_ptr(leaf, slot,
2151 struct btrfs_file_extent_item);
2152 fi = (struct btrfs_file_extent_item *)(
2153 (unsigned long)fi - size_diff);
2155 if (btrfs_file_extent_type(leaf, fi) ==
2156 BTRFS_FILE_EXTENT_INLINE) {
2157 ptr = btrfs_item_ptr_offset(leaf, slot);
2158 memmove_extent_buffer(leaf, ptr,
2160 offsetof(struct btrfs_file_extent_item,
2165 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2166 data_end + size_diff, btrfs_leaf_data(leaf) +
2167 data_end, old_data_start - data_end);
2169 offset = btrfs_disk_key_offset(&disk_key);
2170 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2171 btrfs_set_item_key(leaf, &disk_key, slot);
2173 fixup_low_keys(trans, root, path, &disk_key, 1);
2176 item = btrfs_item_nr(leaf, slot);
2177 btrfs_set_item_size(leaf, item, new_size);
2178 btrfs_mark_buffer_dirty(leaf);
2181 if (btrfs_leaf_free_space(root, leaf) < 0) {
2182 btrfs_print_leaf(root, leaf);
2188 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2189 struct btrfs_root *root, struct btrfs_path *path,
2195 struct extent_buffer *leaf;
2196 struct btrfs_item *item;
2198 unsigned int data_end;
2199 unsigned int old_data;
2200 unsigned int old_size;
2203 slot_orig = path->slots[0];
2204 leaf = path->nodes[0];
2206 nritems = btrfs_header_nritems(leaf);
2207 data_end = leaf_data_end(root, leaf);
2209 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2210 btrfs_print_leaf(root, leaf);
2213 slot = path->slots[0];
2214 old_data = btrfs_item_end_nr(leaf, slot);
2217 if (slot >= nritems) {
2218 btrfs_print_leaf(root, leaf);
2219 printk("slot %d too large, nritems %d\n", slot, nritems);
2224 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2226 /* first correct the data pointers */
2227 for (i = slot; i < nritems; i++) {
2229 item = btrfs_item_nr(leaf, i);
2230 ioff = btrfs_item_offset(leaf, item);
2231 btrfs_set_item_offset(leaf, item, ioff - data_size);
2234 /* shift the data */
2235 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2236 data_end - data_size, btrfs_leaf_data(leaf) +
2237 data_end, old_data - data_end);
2239 data_end = old_data;
2240 old_size = btrfs_item_size_nr(leaf, slot);
2241 item = btrfs_item_nr(leaf, slot);
2242 btrfs_set_item_size(leaf, item, old_size + data_size);
2243 btrfs_mark_buffer_dirty(leaf);
2246 if (btrfs_leaf_free_space(root, leaf) < 0) {
2247 btrfs_print_leaf(root, leaf);
2254 * Given a key and some data, insert an item into the tree.
2255 * This does all the path init required, making room in the tree if needed.
2257 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2258 struct btrfs_root *root,
2259 struct btrfs_path *path,
2260 struct btrfs_key *cpu_key, u32 *data_size,
2263 struct extent_buffer *leaf;
2264 struct btrfs_item *item;
2272 unsigned int data_end;
2273 struct btrfs_disk_key disk_key;
2275 for (i = 0; i < nr; i++) {
2276 total_data += data_size[i];
2279 /* create a root if there isn't one */
2283 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2284 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2291 slot_orig = path->slots[0];
2292 leaf = path->nodes[0];
2294 nritems = btrfs_header_nritems(leaf);
2295 data_end = leaf_data_end(root, leaf);
2297 if (btrfs_leaf_free_space(root, leaf) <
2298 sizeof(struct btrfs_item) + total_size) {
2299 btrfs_print_leaf(root, leaf);
2300 printk("not enough freespace need %u have %d\n",
2301 total_size, btrfs_leaf_free_space(root, leaf));
2305 slot = path->slots[0];
2308 if (slot != nritems) {
2310 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2312 if (old_data < data_end) {
2313 btrfs_print_leaf(root, leaf);
2314 printk("slot %d old_data %d data_end %d\n",
2315 slot, old_data, data_end);
2319 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2321 /* first correct the data pointers */
2322 for (i = slot; i < nritems; i++) {
2325 item = btrfs_item_nr(leaf, i);
2326 ioff = btrfs_item_offset(leaf, item);
2327 btrfs_set_item_offset(leaf, item, ioff - total_data);
2330 /* shift the items */
2331 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2332 btrfs_item_nr_offset(slot),
2333 (nritems - slot) * sizeof(struct btrfs_item));
2335 /* shift the data */
2336 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2337 data_end - total_data, btrfs_leaf_data(leaf) +
2338 data_end, old_data - data_end);
2339 data_end = old_data;
2342 /* setup the item for the new data */
2343 for (i = 0; i < nr; i++) {
2344 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2345 btrfs_set_item_key(leaf, &disk_key, slot + i);
2346 item = btrfs_item_nr(leaf, slot + i);
2347 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2348 data_end -= data_size[i];
2349 btrfs_set_item_size(leaf, item, data_size[i]);
2351 btrfs_set_header_nritems(leaf, nritems + nr);
2352 btrfs_mark_buffer_dirty(leaf);
2356 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2357 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2360 if (btrfs_leaf_free_space(root, leaf) < 0) {
2361 btrfs_print_leaf(root, leaf);
2370 * Given a key and some data, insert an item into the tree.
2371 * This does all the path init required, making room in the tree if needed.
2373 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2374 *root, struct btrfs_key *cpu_key, void *data, u32
2378 struct btrfs_path *path;
2379 struct extent_buffer *leaf;
2382 path = btrfs_alloc_path();
2384 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2386 leaf = path->nodes[0];
2387 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2388 write_extent_buffer(leaf, data, ptr, data_size);
2389 btrfs_mark_buffer_dirty(leaf);
2391 btrfs_free_path(path);
2396 * delete the pointer from a given node.
2398 * If the delete empties a node, the node is removed from the tree,
2399 * continuing all the way the root if required. The root is converted into
2400 * a leaf if all the nodes are emptied.
2402 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2403 struct btrfs_path *path, int level, int slot)
2405 struct extent_buffer *parent = path->nodes[level];
2410 nritems = btrfs_header_nritems(parent);
2411 if (slot != nritems -1) {
2412 memmove_extent_buffer(parent,
2413 btrfs_node_key_ptr_offset(slot),
2414 btrfs_node_key_ptr_offset(slot + 1),
2415 sizeof(struct btrfs_key_ptr) *
2416 (nritems - slot - 1));
2419 btrfs_set_header_nritems(parent, nritems);
2420 if (nritems == 0 && parent == root->node) {
2421 BUG_ON(btrfs_header_level(root->node) != 1);
2422 /* just turn the root into a leaf and break */
2423 btrfs_set_header_level(root->node, 0);
2424 } else if (slot == 0) {
2425 struct btrfs_disk_key disk_key;
2427 btrfs_node_key(parent, &disk_key, 0);
2428 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2432 btrfs_mark_buffer_dirty(parent);
2437 * delete the item at the leaf level in path. If that empties
2438 * the leaf, remove it from the tree
2440 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2441 struct btrfs_path *path, int slot, int nr)
2443 struct extent_buffer *leaf;
2444 struct btrfs_item *item;
2452 leaf = path->nodes[0];
2453 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2455 for (i = 0; i < nr; i++)
2456 dsize += btrfs_item_size_nr(leaf, slot + i);
2458 nritems = btrfs_header_nritems(leaf);
2460 if (slot + nr != nritems) {
2462 int data_end = leaf_data_end(root, leaf);
2464 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2466 btrfs_leaf_data(leaf) + data_end,
2467 last_off - data_end);
2469 for (i = slot + nr; i < nritems; i++) {
2472 item = btrfs_item_nr(leaf, i);
2473 ioff = btrfs_item_offset(leaf, item);
2474 btrfs_set_item_offset(leaf, item, ioff + dsize);
2477 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2478 btrfs_item_nr_offset(slot + nr),
2479 sizeof(struct btrfs_item) *
2480 (nritems - slot - nr));
2482 btrfs_set_header_nritems(leaf, nritems - nr);
2485 /* delete the leaf if we've emptied it */
2487 if (leaf == root->node) {
2488 btrfs_set_header_level(leaf, 0);
2490 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2491 clean_tree_block(trans, root, leaf);
2492 wait_on_tree_block_writeback(root, leaf);
2493 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2496 wret = btrfs_free_extent(trans, root,
2497 leaf->start, leaf->len,
2498 btrfs_header_owner(path->nodes[1]),
2504 int used = leaf_space_used(leaf, 0, nritems);
2506 struct btrfs_disk_key disk_key;
2508 btrfs_item_key(leaf, &disk_key, 0);
2509 wret = fixup_low_keys(trans, root, path,
2515 /* delete the leaf if it is mostly empty */
2516 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2517 /* push_leaf_left fixes the path.
2518 * make sure the path still points to our leaf
2519 * for possible call to del_ptr below
2521 slot = path->slots[1];
2522 extent_buffer_get(leaf);
2524 wret = push_leaf_left(trans, root, path, 1, 1);
2525 if (wret < 0 && wret != -ENOSPC)
2528 if (path->nodes[0] == leaf &&
2529 btrfs_header_nritems(leaf)) {
2530 wret = push_leaf_right(trans, root, path, 1, 1);
2531 if (wret < 0 && wret != -ENOSPC)
2535 if (btrfs_header_nritems(leaf) == 0) {
2537 u64 bytenr = leaf->start;
2538 u32 blocksize = leaf->len;
2540 root_gen = btrfs_header_generation(
2543 clean_tree_block(trans, root, leaf);
2544 wait_on_tree_block_writeback(root, leaf);
2546 wret = del_ptr(trans, root, path, 1, slot);
2550 free_extent_buffer(leaf);
2551 wret = btrfs_free_extent(trans, root, bytenr,
2553 btrfs_header_owner(path->nodes[1]),
2558 btrfs_mark_buffer_dirty(leaf);
2559 free_extent_buffer(leaf);
2562 btrfs_mark_buffer_dirty(leaf);
2569 * walk up the tree as far as required to find the previous leaf.
2570 * returns 0 if it found something or 1 if there are no lesser leaves.
2571 * returns < 0 on io errors.
2573 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2577 struct extent_buffer *c;
2578 struct extent_buffer *next = NULL;
2580 while(level < BTRFS_MAX_LEVEL) {
2581 if (!path->nodes[level])
2584 slot = path->slots[level];
2585 c = path->nodes[level];
2588 if (level == BTRFS_MAX_LEVEL)
2595 free_extent_buffer(next);
2597 next = read_node_slot(root, c, slot);
2600 path->slots[level] = slot;
2603 c = path->nodes[level];
2604 free_extent_buffer(c);
2605 slot = btrfs_header_nritems(next);
2608 path->nodes[level] = next;
2609 path->slots[level] = slot;
2612 next = read_node_slot(root, next, slot);
2618 * walk up the tree as far as required to find the next leaf.
2619 * returns 0 if it found something or 1 if there are no greater leaves.
2620 * returns < 0 on io errors.
2622 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2626 struct extent_buffer *c;
2627 struct extent_buffer *next = NULL;
2629 while(level < BTRFS_MAX_LEVEL) {
2630 if (!path->nodes[level])
2633 slot = path->slots[level] + 1;
2634 c = path->nodes[level];
2635 if (slot >= btrfs_header_nritems(c)) {
2637 if (level == BTRFS_MAX_LEVEL)
2643 free_extent_buffer(next);
2646 reada_for_search(root, path, level, slot, 0);
2648 next = read_node_slot(root, c, slot);
2651 path->slots[level] = slot;
2654 c = path->nodes[level];
2655 free_extent_buffer(c);
2656 path->nodes[level] = next;
2657 path->slots[level] = 0;
2661 reada_for_search(root, path, level, 0, 0);
2662 next = read_node_slot(root, next, 0);
2667 int btrfs_previous_item(struct btrfs_root *root,
2668 struct btrfs_path *path, u64 min_objectid,
2671 struct btrfs_key found_key;
2672 struct extent_buffer *leaf;
2676 if (path->slots[0] == 0) {
2677 ret = btrfs_prev_leaf(root, path);
2683 leaf = path->nodes[0];
2684 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2685 if (found_key.type == type)