2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
26 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_path *path, int level);
28 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
29 *root, struct btrfs_key *ins_key,
30 struct btrfs_path *path, int data_size, int extend);
31 static int push_node_left(struct btrfs_trans_handle *trans,
32 struct btrfs_root *root, struct extent_buffer *dst,
33 struct extent_buffer *src, int empty);
34 static int balance_node_right(struct btrfs_trans_handle *trans,
35 struct btrfs_root *root,
36 struct extent_buffer *dst_buf,
37 struct extent_buffer *src_buf);
38 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
39 struct btrfs_path *path, int level, int slot);
41 inline void btrfs_init_path(struct btrfs_path *p)
43 memset(p, 0, sizeof(*p));
46 struct btrfs_path *btrfs_alloc_path(void)
48 struct btrfs_path *path;
49 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
51 btrfs_init_path(path);
57 void btrfs_free_path(struct btrfs_path *p)
59 btrfs_release_path(NULL, p);
60 kmem_cache_free(btrfs_path_cachep, p);
63 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
67 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
72 btrfs_tree_unlock(p->nodes[i]);
75 free_extent_buffer(p->nodes[i]);
80 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
82 struct extent_buffer *eb;
83 spin_lock(&root->node_lock);
85 extent_buffer_get(eb);
86 spin_unlock(&root->node_lock);
90 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
92 struct extent_buffer *eb;
95 eb = btrfs_root_node(root);
98 spin_lock(&root->node_lock);
99 if (eb == root->node) {
100 spin_unlock(&root->node_lock);
103 spin_unlock(&root->node_lock);
105 btrfs_tree_unlock(eb);
106 free_extent_buffer(eb);
111 static void add_root_to_dirty_list(struct btrfs_root *root)
113 if (root->track_dirty && list_empty(&root->dirty_list)) {
114 list_add(&root->dirty_list,
115 &root->fs_info->dirty_cowonly_roots);
119 int btrfs_copy_root(struct btrfs_trans_handle *trans,
120 struct btrfs_root *root,
121 struct extent_buffer *buf,
122 struct extent_buffer **cow_ret, u64 new_root_objectid)
124 struct extent_buffer *cow;
128 struct btrfs_key first_key;
129 struct btrfs_root *new_root;
131 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
135 memcpy(new_root, root, sizeof(*new_root));
136 new_root->root_key.objectid = new_root_objectid;
138 WARN_ON(root->ref_cows && trans->transid !=
139 root->fs_info->running_transaction->transid);
140 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
142 level = btrfs_header_level(buf);
143 nritems = btrfs_header_nritems(buf);
146 btrfs_item_key_to_cpu(buf, &first_key, 0);
148 btrfs_node_key_to_cpu(buf, &first_key, 0);
150 first_key.objectid = 0;
152 cow = btrfs_alloc_free_block(trans, new_root, buf->len,
154 trans->transid, first_key.objectid,
155 level, buf->start, 0);
161 copy_extent_buffer(cow, buf, 0, 0, cow->len);
162 btrfs_set_header_bytenr(cow, cow->start);
163 btrfs_set_header_generation(cow, trans->transid);
164 btrfs_set_header_owner(cow, new_root_objectid);
165 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
167 WARN_ON(btrfs_header_generation(buf) > trans->transid);
168 ret = btrfs_inc_ref(trans, new_root, buf);
174 btrfs_mark_buffer_dirty(cow);
179 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
180 struct btrfs_root *root,
181 struct extent_buffer *buf,
182 struct extent_buffer *parent, int parent_slot,
183 struct extent_buffer **cow_ret,
184 u64 search_start, u64 empty_size)
187 struct extent_buffer *cow;
190 int different_trans = 0;
193 struct btrfs_key first_key;
198 WARN_ON(!btrfs_tree_locked(buf));
200 if (root->ref_cows) {
201 root_gen = trans->transid;
205 WARN_ON(root->ref_cows && trans->transid !=
206 root->fs_info->running_transaction->transid);
207 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
209 level = btrfs_header_level(buf);
210 nritems = btrfs_header_nritems(buf);
213 btrfs_item_key_to_cpu(buf, &first_key, 0);
215 btrfs_node_key_to_cpu(buf, &first_key, 0);
217 first_key.objectid = 0;
219 cow = btrfs_alloc_free_block(trans, root, buf->len,
220 root->root_key.objectid,
221 root_gen, first_key.objectid, level,
222 search_start, empty_size);
226 copy_extent_buffer(cow, buf, 0, 0, cow->len);
227 btrfs_set_header_bytenr(cow, cow->start);
228 btrfs_set_header_generation(cow, trans->transid);
229 btrfs_set_header_owner(cow, root->root_key.objectid);
230 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
232 WARN_ON(btrfs_header_generation(buf) > trans->transid);
233 if (btrfs_header_generation(buf) != trans->transid) {
235 ret = btrfs_inc_ref(trans, root, buf);
239 clean_tree_block(trans, root, buf);
242 if (buf == root->node) {
243 WARN_ON(parent && parent != buf);
244 root_gen = btrfs_header_generation(buf);
246 spin_lock(&root->node_lock);
248 extent_buffer_get(cow);
249 spin_unlock(&root->node_lock);
251 if (buf != root->commit_root) {
252 btrfs_free_extent(trans, root, buf->start,
253 buf->len, root->root_key.objectid,
256 free_extent_buffer(buf);
257 add_root_to_dirty_list(root);
259 root_gen = btrfs_header_generation(parent);
260 btrfs_set_node_blockptr(parent, parent_slot,
262 WARN_ON(trans->transid == 0);
263 btrfs_set_node_ptr_generation(parent, parent_slot,
265 btrfs_mark_buffer_dirty(parent);
266 WARN_ON(btrfs_header_generation(parent) != trans->transid);
267 btrfs_free_extent(trans, root, buf->start, buf->len,
268 btrfs_header_owner(parent), root_gen,
272 btrfs_tree_unlock(buf);
273 free_extent_buffer(buf);
274 btrfs_mark_buffer_dirty(cow);
279 int btrfs_cow_block(struct btrfs_trans_handle *trans,
280 struct btrfs_root *root, struct extent_buffer *buf,
281 struct extent_buffer *parent, int parent_slot,
282 struct extent_buffer **cow_ret)
288 if (trans->transaction != root->fs_info->running_transaction) {
289 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
290 root->fs_info->running_transaction->transid);
293 if (trans->transid != root->fs_info->generation) {
294 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
295 root->fs_info->generation);
299 header_trans = btrfs_header_generation(buf);
300 spin_lock(&root->fs_info->hash_lock);
301 if (header_trans == trans->transid &&
302 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
304 spin_unlock(&root->fs_info->hash_lock);
307 spin_unlock(&root->fs_info->hash_lock);
308 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
309 ret = __btrfs_cow_block(trans, root, buf, parent,
310 parent_slot, cow_ret, search_start, 0);
314 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
316 if (blocknr < other && other - (blocknr + blocksize) < 32768)
318 if (blocknr > other && blocknr - (other + blocksize) < 32768)
324 * compare two keys in a memcmp fashion
326 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
330 btrfs_disk_key_to_cpu(&k1, disk);
332 if (k1.objectid > k2->objectid)
334 if (k1.objectid < k2->objectid)
336 if (k1.type > k2->type)
338 if (k1.type < k2->type)
340 if (k1.offset > k2->offset)
342 if (k1.offset < k2->offset)
348 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
349 struct btrfs_root *root, struct extent_buffer *parent,
350 int start_slot, int cache_only, u64 *last_ret,
351 struct btrfs_key *progress)
353 struct extent_buffer *cur;
356 u64 search_start = *last_ret;
366 int progress_passed = 0;
367 struct btrfs_disk_key disk_key;
369 parent_level = btrfs_header_level(parent);
370 if (cache_only && parent_level != 1)
373 if (trans->transaction != root->fs_info->running_transaction) {
374 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
375 root->fs_info->running_transaction->transid);
378 if (trans->transid != root->fs_info->generation) {
379 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
380 root->fs_info->generation);
384 parent_nritems = btrfs_header_nritems(parent);
385 blocksize = btrfs_level_size(root, parent_level - 1);
386 end_slot = parent_nritems;
388 if (parent_nritems == 1)
391 for (i = start_slot; i < end_slot; i++) {
394 if (!parent->map_token) {
395 map_extent_buffer(parent,
396 btrfs_node_key_ptr_offset(i),
397 sizeof(struct btrfs_key_ptr),
398 &parent->map_token, &parent->kaddr,
399 &parent->map_start, &parent->map_len,
402 btrfs_node_key(parent, &disk_key, i);
403 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
407 blocknr = btrfs_node_blockptr(parent, i);
408 gen = btrfs_node_ptr_generation(parent, i);
410 last_block = blocknr;
413 other = btrfs_node_blockptr(parent, i - 1);
414 close = close_blocks(blocknr, other, blocksize);
416 if (!close && i < end_slot - 2) {
417 other = btrfs_node_blockptr(parent, i + 1);
418 close = close_blocks(blocknr, other, blocksize);
421 last_block = blocknr;
424 if (parent->map_token) {
425 unmap_extent_buffer(parent, parent->map_token,
427 parent->map_token = NULL;
430 cur = btrfs_find_tree_block(root, blocknr, blocksize);
432 uptodate = btrfs_buffer_uptodate(cur, gen);
435 if (!cur || !uptodate) {
437 free_extent_buffer(cur);
441 cur = read_tree_block(root, blocknr,
443 } else if (!uptodate) {
444 btrfs_read_buffer(cur, gen);
447 if (search_start == 0)
448 search_start = last_block;
450 btrfs_tree_lock(cur);
451 err = __btrfs_cow_block(trans, root, cur, parent, i,
454 (end_slot - i) * blocksize));
456 btrfs_tree_unlock(cur);
457 free_extent_buffer(cur);
460 search_start = cur->start;
461 last_block = cur->start;
462 *last_ret = search_start;
463 btrfs_tree_unlock(cur);
464 free_extent_buffer(cur);
466 if (parent->map_token) {
467 unmap_extent_buffer(parent, parent->map_token,
469 parent->map_token = NULL;
475 * The leaf data grows from end-to-front in the node.
476 * this returns the address of the start of the last item,
477 * which is the stop of the leaf data stack
479 static inline unsigned int leaf_data_end(struct btrfs_root *root,
480 struct extent_buffer *leaf)
482 u32 nr = btrfs_header_nritems(leaf);
484 return BTRFS_LEAF_DATA_SIZE(root);
485 return btrfs_item_offset_nr(leaf, nr - 1);
488 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
491 struct extent_buffer *parent = NULL;
492 struct extent_buffer *node = path->nodes[level];
493 struct btrfs_disk_key parent_key;
494 struct btrfs_disk_key node_key;
497 struct btrfs_key cpukey;
498 u32 nritems = btrfs_header_nritems(node);
500 if (path->nodes[level + 1])
501 parent = path->nodes[level + 1];
503 slot = path->slots[level];
504 BUG_ON(nritems == 0);
506 parent_slot = path->slots[level + 1];
507 btrfs_node_key(parent, &parent_key, parent_slot);
508 btrfs_node_key(node, &node_key, 0);
509 BUG_ON(memcmp(&parent_key, &node_key,
510 sizeof(struct btrfs_disk_key)));
511 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
512 btrfs_header_bytenr(node));
514 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
516 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
517 btrfs_node_key(node, &node_key, slot);
518 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
520 if (slot < nritems - 1) {
521 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
522 btrfs_node_key(node, &node_key, slot);
523 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
528 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
531 struct extent_buffer *leaf = path->nodes[level];
532 struct extent_buffer *parent = NULL;
534 struct btrfs_key cpukey;
535 struct btrfs_disk_key parent_key;
536 struct btrfs_disk_key leaf_key;
537 int slot = path->slots[0];
539 u32 nritems = btrfs_header_nritems(leaf);
541 if (path->nodes[level + 1])
542 parent = path->nodes[level + 1];
548 parent_slot = path->slots[level + 1];
549 btrfs_node_key(parent, &parent_key, parent_slot);
550 btrfs_item_key(leaf, &leaf_key, 0);
552 BUG_ON(memcmp(&parent_key, &leaf_key,
553 sizeof(struct btrfs_disk_key)));
554 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
555 btrfs_header_bytenr(leaf));
558 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
559 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
560 btrfs_item_key(leaf, &leaf_key, i);
561 if (comp_keys(&leaf_key, &cpukey) >= 0) {
562 btrfs_print_leaf(root, leaf);
563 printk("slot %d offset bad key\n", i);
566 if (btrfs_item_offset_nr(leaf, i) !=
567 btrfs_item_end_nr(leaf, i + 1)) {
568 btrfs_print_leaf(root, leaf);
569 printk("slot %d offset bad\n", i);
573 if (btrfs_item_offset_nr(leaf, i) +
574 btrfs_item_size_nr(leaf, i) !=
575 BTRFS_LEAF_DATA_SIZE(root)) {
576 btrfs_print_leaf(root, leaf);
577 printk("slot %d first offset bad\n", i);
583 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
584 btrfs_print_leaf(root, leaf);
585 printk("slot %d bad size \n", nritems - 1);
590 if (slot != 0 && slot < nritems - 1) {
591 btrfs_item_key(leaf, &leaf_key, slot);
592 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
593 if (comp_keys(&leaf_key, &cpukey) <= 0) {
594 btrfs_print_leaf(root, leaf);
595 printk("slot %d offset bad key\n", slot);
598 if (btrfs_item_offset_nr(leaf, slot - 1) !=
599 btrfs_item_end_nr(leaf, slot)) {
600 btrfs_print_leaf(root, leaf);
601 printk("slot %d offset bad\n", slot);
605 if (slot < nritems - 1) {
606 btrfs_item_key(leaf, &leaf_key, slot);
607 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
608 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
609 if (btrfs_item_offset_nr(leaf, slot) !=
610 btrfs_item_end_nr(leaf, slot + 1)) {
611 btrfs_print_leaf(root, leaf);
612 printk("slot %d offset bad\n", slot);
616 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
617 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
621 static int noinline check_block(struct btrfs_root *root,
622 struct btrfs_path *path, int level)
626 if (btrfs_header_level(path->nodes[level]) != level)
627 printk("warning: bad level %Lu wanted %d found %d\n",
628 path->nodes[level]->start, level,
629 btrfs_header_level(path->nodes[level]));
630 found_start = btrfs_header_bytenr(path->nodes[level]);
631 if (found_start != path->nodes[level]->start) {
632 printk("warning: bad bytentr %Lu found %Lu\n",
633 path->nodes[level]->start, found_start);
636 struct extent_buffer *buf = path->nodes[level];
638 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
639 (unsigned long)btrfs_header_fsid(buf),
641 printk("warning bad block %Lu\n", buf->start);
646 return check_leaf(root, path, level);
647 return check_node(root, path, level);
651 * search for key in the extent_buffer. The items start at offset p,
652 * and they are item_size apart. There are 'max' items in p.
654 * the slot in the array is returned via slot, and it points to
655 * the place where you would insert key if it is not found in
658 * slot may point to max if the key is bigger than all of the keys
660 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
661 int item_size, struct btrfs_key *key,
668 struct btrfs_disk_key *tmp = NULL;
669 struct btrfs_disk_key unaligned;
670 unsigned long offset;
671 char *map_token = NULL;
673 unsigned long map_start = 0;
674 unsigned long map_len = 0;
678 mid = (low + high) / 2;
679 offset = p + mid * item_size;
681 if (!map_token || offset < map_start ||
682 (offset + sizeof(struct btrfs_disk_key)) >
683 map_start + map_len) {
685 unmap_extent_buffer(eb, map_token, KM_USER0);
688 err = map_extent_buffer(eb, offset,
689 sizeof(struct btrfs_disk_key),
691 &map_start, &map_len, KM_USER0);
694 tmp = (struct btrfs_disk_key *)(kaddr + offset -
697 read_extent_buffer(eb, &unaligned,
698 offset, sizeof(unaligned));
703 tmp = (struct btrfs_disk_key *)(kaddr + offset -
706 ret = comp_keys(tmp, key);
715 unmap_extent_buffer(eb, map_token, KM_USER0);
721 unmap_extent_buffer(eb, map_token, KM_USER0);
726 * simple bin_search frontend that does the right thing for
729 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
730 int level, int *slot)
733 return generic_bin_search(eb,
734 offsetof(struct btrfs_leaf, items),
735 sizeof(struct btrfs_item),
736 key, btrfs_header_nritems(eb),
739 return generic_bin_search(eb,
740 offsetof(struct btrfs_node, ptrs),
741 sizeof(struct btrfs_key_ptr),
742 key, btrfs_header_nritems(eb),
748 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
749 struct extent_buffer *parent, int slot)
751 int level = btrfs_header_level(parent);
754 if (slot >= btrfs_header_nritems(parent))
759 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
760 btrfs_level_size(root, level - 1),
761 btrfs_node_ptr_generation(parent, slot));
764 static int balance_level(struct btrfs_trans_handle *trans,
765 struct btrfs_root *root,
766 struct btrfs_path *path, int level)
768 struct extent_buffer *right = NULL;
769 struct extent_buffer *mid;
770 struct extent_buffer *left = NULL;
771 struct extent_buffer *parent = NULL;
775 int orig_slot = path->slots[level];
776 int err_on_enospc = 0;
782 mid = path->nodes[level];
783 WARN_ON(!path->locks[level]);
784 WARN_ON(btrfs_header_generation(mid) != trans->transid);
786 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
788 if (level < BTRFS_MAX_LEVEL - 1)
789 parent = path->nodes[level + 1];
790 pslot = path->slots[level + 1];
793 * deal with the case where there is only one pointer in the root
794 * by promoting the node below to a root
797 struct extent_buffer *child;
799 if (btrfs_header_nritems(mid) != 1)
802 /* promote the child to a root */
803 child = read_node_slot(root, mid, 0);
804 btrfs_tree_lock(child);
806 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
809 spin_lock(&root->node_lock);
811 spin_unlock(&root->node_lock);
813 add_root_to_dirty_list(root);
814 btrfs_tree_unlock(child);
815 path->locks[level] = 0;
816 path->nodes[level] = NULL;
817 clean_tree_block(trans, root, mid);
818 btrfs_tree_unlock(mid);
819 /* once for the path */
820 free_extent_buffer(mid);
821 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
822 root->root_key.objectid,
823 btrfs_header_generation(mid), 0, 0, 1);
824 /* once for the root ptr */
825 free_extent_buffer(mid);
828 if (btrfs_header_nritems(mid) >
829 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
832 if (btrfs_header_nritems(mid) < 2)
835 left = read_node_slot(root, parent, pslot - 1);
837 btrfs_tree_lock(left);
838 wret = btrfs_cow_block(trans, root, left,
839 parent, pslot - 1, &left);
845 right = read_node_slot(root, parent, pslot + 1);
847 btrfs_tree_lock(right);
848 wret = btrfs_cow_block(trans, root, right,
849 parent, pslot + 1, &right);
856 /* first, try to make some room in the middle buffer */
858 orig_slot += btrfs_header_nritems(left);
859 wret = push_node_left(trans, root, left, mid, 1);
862 if (btrfs_header_nritems(mid) < 2)
867 * then try to empty the right most buffer into the middle
870 wret = push_node_left(trans, root, mid, right, 1);
871 if (wret < 0 && wret != -ENOSPC)
873 if (btrfs_header_nritems(right) == 0) {
874 u64 bytenr = right->start;
875 u64 generation = btrfs_header_generation(parent);
876 u32 blocksize = right->len;
878 clean_tree_block(trans, root, right);
879 btrfs_tree_unlock(right);
880 free_extent_buffer(right);
882 wret = del_ptr(trans, root, path, level + 1, pslot +
886 wret = btrfs_free_extent(trans, root, bytenr,
888 btrfs_header_owner(parent),
889 generation, 0, 0, 1);
893 struct btrfs_disk_key right_key;
894 btrfs_node_key(right, &right_key, 0);
895 btrfs_set_node_key(parent, &right_key, pslot + 1);
896 btrfs_mark_buffer_dirty(parent);
899 if (btrfs_header_nritems(mid) == 1) {
901 * we're not allowed to leave a node with one item in the
902 * tree during a delete. A deletion from lower in the tree
903 * could try to delete the only pointer in this node.
904 * So, pull some keys from the left.
905 * There has to be a left pointer at this point because
906 * otherwise we would have pulled some pointers from the
910 wret = balance_node_right(trans, root, mid, left);
916 wret = push_node_left(trans, root, left, mid, 1);
922 if (btrfs_header_nritems(mid) == 0) {
923 /* we've managed to empty the middle node, drop it */
924 u64 root_gen = btrfs_header_generation(parent);
925 u64 bytenr = mid->start;
926 u32 blocksize = mid->len;
928 clean_tree_block(trans, root, mid);
929 btrfs_tree_unlock(mid);
930 free_extent_buffer(mid);
932 wret = del_ptr(trans, root, path, level + 1, pslot);
935 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
936 btrfs_header_owner(parent),
941 /* update the parent key to reflect our changes */
942 struct btrfs_disk_key mid_key;
943 btrfs_node_key(mid, &mid_key, 0);
944 btrfs_set_node_key(parent, &mid_key, pslot);
945 btrfs_mark_buffer_dirty(parent);
948 /* update the path */
950 if (btrfs_header_nritems(left) > orig_slot) {
951 extent_buffer_get(left);
952 /* left was locked after cow */
953 path->nodes[level] = left;
954 path->slots[level + 1] -= 1;
955 path->slots[level] = orig_slot;
957 btrfs_tree_unlock(mid);
958 free_extent_buffer(mid);
961 orig_slot -= btrfs_header_nritems(left);
962 path->slots[level] = orig_slot;
965 /* double check we haven't messed things up */
966 check_block(root, path, level);
968 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
972 btrfs_tree_unlock(right);
973 free_extent_buffer(right);
976 if (path->nodes[level] != left)
977 btrfs_tree_unlock(left);
978 free_extent_buffer(left);
983 /* returns zero if the push worked, non-zero otherwise */
984 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
985 struct btrfs_root *root,
986 struct btrfs_path *path, int level)
988 struct extent_buffer *right = NULL;
989 struct extent_buffer *mid;
990 struct extent_buffer *left = NULL;
991 struct extent_buffer *parent = NULL;
995 int orig_slot = path->slots[level];
1001 mid = path->nodes[level];
1002 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1003 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1005 if (level < BTRFS_MAX_LEVEL - 1)
1006 parent = path->nodes[level + 1];
1007 pslot = path->slots[level + 1];
1012 left = read_node_slot(root, parent, pslot - 1);
1014 /* first, try to make some room in the middle buffer */
1018 btrfs_tree_lock(left);
1019 left_nr = btrfs_header_nritems(left);
1020 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1023 ret = btrfs_cow_block(trans, root, left, parent,
1028 wret = push_node_left(trans, root,
1035 struct btrfs_disk_key disk_key;
1036 orig_slot += left_nr;
1037 btrfs_node_key(mid, &disk_key, 0);
1038 btrfs_set_node_key(parent, &disk_key, pslot);
1039 btrfs_mark_buffer_dirty(parent);
1040 if (btrfs_header_nritems(left) > orig_slot) {
1041 path->nodes[level] = left;
1042 path->slots[level + 1] -= 1;
1043 path->slots[level] = orig_slot;
1044 btrfs_tree_unlock(mid);
1045 free_extent_buffer(mid);
1048 btrfs_header_nritems(left);
1049 path->slots[level] = orig_slot;
1050 btrfs_tree_unlock(left);
1051 free_extent_buffer(left);
1055 btrfs_tree_unlock(left);
1056 free_extent_buffer(left);
1058 right = read_node_slot(root, parent, pslot + 1);
1061 * then try to empty the right most buffer into the middle
1065 btrfs_tree_lock(right);
1066 right_nr = btrfs_header_nritems(right);
1067 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1070 ret = btrfs_cow_block(trans, root, right,
1076 wret = balance_node_right(trans, root,
1083 struct btrfs_disk_key disk_key;
1085 btrfs_node_key(right, &disk_key, 0);
1086 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1087 btrfs_mark_buffer_dirty(parent);
1089 if (btrfs_header_nritems(mid) <= orig_slot) {
1090 path->nodes[level] = right;
1091 path->slots[level + 1] += 1;
1092 path->slots[level] = orig_slot -
1093 btrfs_header_nritems(mid);
1094 btrfs_tree_unlock(mid);
1095 free_extent_buffer(mid);
1097 btrfs_tree_unlock(right);
1098 free_extent_buffer(right);
1102 btrfs_tree_unlock(right);
1103 free_extent_buffer(right);
1109 * readahead one full node of leaves
1111 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1112 int level, int slot, u64 objectid)
1114 struct extent_buffer *node;
1115 struct btrfs_disk_key disk_key;
1121 int direction = path->reada;
1122 struct extent_buffer *eb;
1130 if (!path->nodes[level])
1133 node = path->nodes[level];
1135 search = btrfs_node_blockptr(node, slot);
1136 blocksize = btrfs_level_size(root, level - 1);
1137 eb = btrfs_find_tree_block(root, search, blocksize);
1139 free_extent_buffer(eb);
1143 highest_read = search;
1144 lowest_read = search;
1146 nritems = btrfs_header_nritems(node);
1149 if (direction < 0) {
1153 } else if (direction > 0) {
1158 if (path->reada < 0 && objectid) {
1159 btrfs_node_key(node, &disk_key, nr);
1160 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1163 search = btrfs_node_blockptr(node, nr);
1164 if ((search >= lowest_read && search <= highest_read) ||
1165 (search < lowest_read && lowest_read - search <= 32768) ||
1166 (search > highest_read && search - highest_read <= 32768)) {
1167 readahead_tree_block(root, search, blocksize,
1168 btrfs_node_ptr_generation(node, nr));
1172 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1174 if(nread > (1024 * 1024) || nscan > 128)
1177 if (search < lowest_read)
1178 lowest_read = search;
1179 if (search > highest_read)
1180 highest_read = search;
1184 static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock)
1187 int skip_level = level;
1189 struct extent_buffer *t;
1191 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1192 if (!path->nodes[i])
1194 if (!path->locks[i])
1196 if (!no_skips && path->slots[i] == 0) {
1200 if (!no_skips && path->keep_locks) {
1203 nritems = btrfs_header_nritems(t);
1204 if (nritems < 1 || path->slots[i] >= nritems - 1) {
1209 if (skip_level < i && i >= lowest_unlock)
1213 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1214 btrfs_tree_unlock(t);
1221 * look for key in the tree. path is filled in with nodes along the way
1222 * if key is found, we return zero and you can find the item in the leaf
1223 * level of the path (level 0)
1225 * If the key isn't found, the path points to the slot where it should
1226 * be inserted, and 1 is returned. If there are other errors during the
1227 * search a negative error number is returned.
1229 * if ins_len > 0, nodes and leaves will be split as we walk down the
1230 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1233 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1234 *root, struct btrfs_key *key, struct btrfs_path *p, int
1237 struct extent_buffer *b;
1238 struct extent_buffer *tmp;
1242 int should_reada = p->reada;
1243 int lowest_unlock = 1;
1245 u8 lowest_level = 0;
1249 lowest_level = p->lowest_level;
1250 WARN_ON(lowest_level && ins_len);
1251 WARN_ON(p->nodes[0] != NULL);
1252 WARN_ON(cow && root == root->fs_info->extent_root &&
1253 !mutex_is_locked(&root->fs_info->alloc_mutex));
1254 WARN_ON(root == root->fs_info->chunk_root &&
1255 !mutex_is_locked(&root->fs_info->chunk_mutex));
1256 WARN_ON(root == root->fs_info->dev_root &&
1257 !mutex_is_locked(&root->fs_info->chunk_mutex));
1261 if (p->skip_locking)
1262 b = btrfs_root_node(root);
1264 b = btrfs_lock_root_node(root);
1267 level = btrfs_header_level(b);
1270 wret = btrfs_cow_block(trans, root, b,
1271 p->nodes[level + 1],
1272 p->slots[level + 1],
1275 free_extent_buffer(b);
1279 BUG_ON(!cow && ins_len);
1280 if (level != btrfs_header_level(b))
1282 level = btrfs_header_level(b);
1283 p->nodes[level] = b;
1284 if (!p->skip_locking)
1285 p->locks[level] = 1;
1286 ret = check_block(root, p, level);
1290 ret = bin_search(b, key, level, &slot);
1292 if (ret && slot > 0)
1294 p->slots[level] = slot;
1295 if (ins_len > 0 && btrfs_header_nritems(b) >=
1296 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1297 int sret = split_node(trans, root, p, level);
1301 b = p->nodes[level];
1302 slot = p->slots[level];
1303 } else if (ins_len < 0) {
1304 int sret = balance_level(trans, root, p,
1308 b = p->nodes[level];
1310 btrfs_release_path(NULL, p);
1313 slot = p->slots[level];
1314 BUG_ON(btrfs_header_nritems(b) == 1);
1316 unlock_up(p, level, lowest_unlock);
1318 /* this is only true while dropping a snapshot */
1319 if (level == lowest_level) {
1323 blocknr = btrfs_node_blockptr(b, slot);
1324 gen = btrfs_node_ptr_generation(b, slot);
1325 blocksize = btrfs_level_size(root, level - 1);
1327 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1328 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
1332 * reduce lock contention at high levels
1333 * of the btree by dropping locks before
1337 btrfs_release_path(NULL, p);
1339 free_extent_buffer(tmp);
1341 reada_for_search(root, p,
1345 tmp = read_tree_block(root, blocknr,
1348 free_extent_buffer(tmp);
1352 free_extent_buffer(tmp);
1354 reada_for_search(root, p,
1357 b = read_node_slot(root, b, slot);
1360 if (!p->skip_locking)
1363 p->slots[level] = slot;
1364 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1365 sizeof(struct btrfs_item) + ins_len) {
1366 int sret = split_leaf(trans, root, key,
1367 p, ins_len, ret == 0);
1372 unlock_up(p, level, lowest_unlock);
1380 * adjust the pointers going up the tree, starting at level
1381 * making sure the right key of each node is points to 'key'.
1382 * This is used after shifting pointers to the left, so it stops
1383 * fixing up pointers when a given leaf/node is not in slot 0 of the
1386 * If this fails to write a tree block, it returns -1, but continues
1387 * fixing up the blocks in ram so the tree is consistent.
1389 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1390 struct btrfs_root *root, struct btrfs_path *path,
1391 struct btrfs_disk_key *key, int level)
1395 struct extent_buffer *t;
1397 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1398 int tslot = path->slots[i];
1399 if (!path->nodes[i])
1402 btrfs_set_node_key(t, key, tslot);
1403 btrfs_mark_buffer_dirty(path->nodes[i]);
1411 * try to push data from one node into the next node left in the
1414 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1415 * error, and > 0 if there was no room in the left hand block.
1417 static int push_node_left(struct btrfs_trans_handle *trans,
1418 struct btrfs_root *root, struct extent_buffer *dst,
1419 struct extent_buffer *src, int empty)
1426 src_nritems = btrfs_header_nritems(src);
1427 dst_nritems = btrfs_header_nritems(dst);
1428 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1429 WARN_ON(btrfs_header_generation(src) != trans->transid);
1430 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1432 if (!empty && src_nritems <= 8)
1435 if (push_items <= 0) {
1440 push_items = min(src_nritems, push_items);
1441 if (push_items < src_nritems) {
1442 /* leave at least 8 pointers in the node if
1443 * we aren't going to empty it
1445 if (src_nritems - push_items < 8) {
1446 if (push_items <= 8)
1452 push_items = min(src_nritems - 8, push_items);
1454 copy_extent_buffer(dst, src,
1455 btrfs_node_key_ptr_offset(dst_nritems),
1456 btrfs_node_key_ptr_offset(0),
1457 push_items * sizeof(struct btrfs_key_ptr));
1459 if (push_items < src_nritems) {
1460 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1461 btrfs_node_key_ptr_offset(push_items),
1462 (src_nritems - push_items) *
1463 sizeof(struct btrfs_key_ptr));
1465 btrfs_set_header_nritems(src, src_nritems - push_items);
1466 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1467 btrfs_mark_buffer_dirty(src);
1468 btrfs_mark_buffer_dirty(dst);
1473 * try to push data from one node into the next node right in the
1476 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1477 * error, and > 0 if there was no room in the right hand block.
1479 * this will only push up to 1/2 the contents of the left node over
1481 static int balance_node_right(struct btrfs_trans_handle *trans,
1482 struct btrfs_root *root,
1483 struct extent_buffer *dst,
1484 struct extent_buffer *src)
1492 WARN_ON(btrfs_header_generation(src) != trans->transid);
1493 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1495 src_nritems = btrfs_header_nritems(src);
1496 dst_nritems = btrfs_header_nritems(dst);
1497 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1498 if (push_items <= 0) {
1502 if (src_nritems < 4) {
1506 max_push = src_nritems / 2 + 1;
1507 /* don't try to empty the node */
1508 if (max_push >= src_nritems) {
1512 if (max_push < push_items)
1513 push_items = max_push;
1515 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1516 btrfs_node_key_ptr_offset(0),
1518 sizeof(struct btrfs_key_ptr));
1520 copy_extent_buffer(dst, src,
1521 btrfs_node_key_ptr_offset(0),
1522 btrfs_node_key_ptr_offset(src_nritems - push_items),
1523 push_items * sizeof(struct btrfs_key_ptr));
1525 btrfs_set_header_nritems(src, src_nritems - push_items);
1526 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1528 btrfs_mark_buffer_dirty(src);
1529 btrfs_mark_buffer_dirty(dst);
1534 * helper function to insert a new root level in the tree.
1535 * A new node is allocated, and a single item is inserted to
1536 * point to the existing root
1538 * returns zero on success or < 0 on failure.
1540 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1541 struct btrfs_root *root,
1542 struct btrfs_path *path, int level)
1546 struct extent_buffer *lower;
1547 struct extent_buffer *c;
1548 struct extent_buffer *old;
1549 struct btrfs_disk_key lower_key;
1551 BUG_ON(path->nodes[level]);
1552 BUG_ON(path->nodes[level-1] != root->node);
1555 root_gen = trans->transid;
1559 lower = path->nodes[level-1];
1561 btrfs_item_key(lower, &lower_key, 0);
1563 btrfs_node_key(lower, &lower_key, 0);
1565 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1566 root->root_key.objectid,
1567 root_gen, lower_key.objectid, level,
1568 root->node->start, 0);
1572 memset_extent_buffer(c, 0, 0, root->nodesize);
1573 btrfs_set_header_nritems(c, 1);
1574 btrfs_set_header_level(c, level);
1575 btrfs_set_header_bytenr(c, c->start);
1576 btrfs_set_header_generation(c, trans->transid);
1577 btrfs_set_header_owner(c, root->root_key.objectid);
1579 write_extent_buffer(c, root->fs_info->fsid,
1580 (unsigned long)btrfs_header_fsid(c),
1583 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1584 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1587 btrfs_set_node_key(c, &lower_key, 0);
1588 btrfs_set_node_blockptr(c, 0, lower->start);
1589 lower_gen = btrfs_header_generation(lower);
1590 WARN_ON(lower_gen == 0);
1592 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1594 btrfs_mark_buffer_dirty(c);
1596 spin_lock(&root->node_lock);
1599 spin_unlock(&root->node_lock);
1601 /* the super has an extra ref to root->node */
1602 free_extent_buffer(old);
1604 add_root_to_dirty_list(root);
1605 extent_buffer_get(c);
1606 path->nodes[level] = c;
1607 path->locks[level] = 1;
1608 path->slots[level] = 0;
1610 if (root->ref_cows && lower_gen != trans->transid) {
1611 struct btrfs_path *back_path = btrfs_alloc_path();
1613 mutex_lock(&root->fs_info->alloc_mutex);
1614 ret = btrfs_insert_extent_backref(trans,
1615 root->fs_info->extent_root,
1617 root->root_key.objectid,
1618 trans->transid, 0, 0);
1620 mutex_unlock(&root->fs_info->alloc_mutex);
1621 btrfs_free_path(back_path);
1627 * worker function to insert a single pointer in a node.
1628 * the node should have enough room for the pointer already
1630 * slot and level indicate where you want the key to go, and
1631 * blocknr is the block the key points to.
1633 * returns zero on success and < 0 on any error
1635 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1636 *root, struct btrfs_path *path, struct btrfs_disk_key
1637 *key, u64 bytenr, int slot, int level)
1639 struct extent_buffer *lower;
1642 BUG_ON(!path->nodes[level]);
1643 lower = path->nodes[level];
1644 nritems = btrfs_header_nritems(lower);
1647 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1649 if (slot != nritems) {
1650 memmove_extent_buffer(lower,
1651 btrfs_node_key_ptr_offset(slot + 1),
1652 btrfs_node_key_ptr_offset(slot),
1653 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1655 btrfs_set_node_key(lower, key, slot);
1656 btrfs_set_node_blockptr(lower, slot, bytenr);
1657 WARN_ON(trans->transid == 0);
1658 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1659 btrfs_set_header_nritems(lower, nritems + 1);
1660 btrfs_mark_buffer_dirty(lower);
1665 * split the node at the specified level in path in two.
1666 * The path is corrected to point to the appropriate node after the split
1668 * Before splitting this tries to make some room in the node by pushing
1669 * left and right, if either one works, it returns right away.
1671 * returns 0 on success and < 0 on failure
1673 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1674 *root, struct btrfs_path *path, int level)
1677 struct extent_buffer *c;
1678 struct extent_buffer *split;
1679 struct btrfs_disk_key disk_key;
1685 c = path->nodes[level];
1686 WARN_ON(btrfs_header_generation(c) != trans->transid);
1687 if (c == root->node) {
1688 /* trying to split the root, lets make a new one */
1689 ret = insert_new_root(trans, root, path, level + 1);
1693 ret = push_nodes_for_insert(trans, root, path, level);
1694 c = path->nodes[level];
1695 if (!ret && btrfs_header_nritems(c) <
1696 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1702 c_nritems = btrfs_header_nritems(c);
1704 root_gen = trans->transid;
1708 btrfs_node_key(c, &disk_key, 0);
1709 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1710 root->root_key.objectid,
1712 btrfs_disk_key_objectid(&disk_key),
1713 level, c->start, 0);
1715 return PTR_ERR(split);
1717 btrfs_set_header_flags(split, btrfs_header_flags(c));
1718 btrfs_set_header_level(split, btrfs_header_level(c));
1719 btrfs_set_header_bytenr(split, split->start);
1720 btrfs_set_header_generation(split, trans->transid);
1721 btrfs_set_header_owner(split, root->root_key.objectid);
1722 btrfs_set_header_flags(split, 0);
1723 write_extent_buffer(split, root->fs_info->fsid,
1724 (unsigned long)btrfs_header_fsid(split),
1726 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1727 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1730 mid = (c_nritems + 1) / 2;
1732 copy_extent_buffer(split, c,
1733 btrfs_node_key_ptr_offset(0),
1734 btrfs_node_key_ptr_offset(mid),
1735 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1736 btrfs_set_header_nritems(split, c_nritems - mid);
1737 btrfs_set_header_nritems(c, mid);
1740 btrfs_mark_buffer_dirty(c);
1741 btrfs_mark_buffer_dirty(split);
1743 btrfs_node_key(split, &disk_key, 0);
1744 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1745 path->slots[level + 1] + 1,
1750 if (path->slots[level] >= mid) {
1751 path->slots[level] -= mid;
1752 btrfs_tree_unlock(c);
1753 free_extent_buffer(c);
1754 path->nodes[level] = split;
1755 path->slots[level + 1] += 1;
1757 btrfs_tree_unlock(split);
1758 free_extent_buffer(split);
1764 * how many bytes are required to store the items in a leaf. start
1765 * and nr indicate which items in the leaf to check. This totals up the
1766 * space used both by the item structs and the item data
1768 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1771 int nritems = btrfs_header_nritems(l);
1772 int end = min(nritems, start + nr) - 1;
1776 data_len = btrfs_item_end_nr(l, start);
1777 data_len = data_len - btrfs_item_offset_nr(l, end);
1778 data_len += sizeof(struct btrfs_item) * nr;
1779 WARN_ON(data_len < 0);
1784 * The space between the end of the leaf items and
1785 * the start of the leaf data. IOW, how much room
1786 * the leaf has left for both items and data
1788 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1790 int nritems = btrfs_header_nritems(leaf);
1792 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1794 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1795 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1796 leaf_space_used(leaf, 0, nritems), nritems);
1802 * push some data in the path leaf to the right, trying to free up at
1803 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1805 * returns 1 if the push failed because the other node didn't have enough
1806 * room, 0 if everything worked out and < 0 if there were major errors.
1808 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1809 *root, struct btrfs_path *path, int data_size,
1812 struct extent_buffer *left = path->nodes[0];
1813 struct extent_buffer *right;
1814 struct extent_buffer *upper;
1815 struct btrfs_disk_key disk_key;
1821 struct btrfs_item *item;
1829 slot = path->slots[1];
1830 if (!path->nodes[1]) {
1833 upper = path->nodes[1];
1834 if (slot >= btrfs_header_nritems(upper) - 1)
1837 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
1839 right = read_node_slot(root, upper, slot + 1);
1840 btrfs_tree_lock(right);
1841 free_space = btrfs_leaf_free_space(root, right);
1842 if (free_space < data_size + sizeof(struct btrfs_item))
1845 /* cow and double check */
1846 ret = btrfs_cow_block(trans, root, right, upper,
1851 free_space = btrfs_leaf_free_space(root, right);
1852 if (free_space < data_size + sizeof(struct btrfs_item))
1855 left_nritems = btrfs_header_nritems(left);
1856 if (left_nritems == 0)
1864 i = left_nritems - 1;
1866 item = btrfs_item_nr(left, i);
1868 if (path->slots[0] == i)
1869 push_space += data_size + sizeof(*item);
1871 if (!left->map_token) {
1872 map_extent_buffer(left, (unsigned long)item,
1873 sizeof(struct btrfs_item),
1874 &left->map_token, &left->kaddr,
1875 &left->map_start, &left->map_len,
1879 this_item_size = btrfs_item_size(left, item);
1880 if (this_item_size + sizeof(*item) + push_space > free_space)
1883 push_space += this_item_size + sizeof(*item);
1888 if (left->map_token) {
1889 unmap_extent_buffer(left, left->map_token, KM_USER1);
1890 left->map_token = NULL;
1893 if (push_items == 0)
1896 if (!empty && push_items == left_nritems)
1899 /* push left to right */
1900 right_nritems = btrfs_header_nritems(right);
1902 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1903 push_space -= leaf_data_end(root, left);
1905 /* make room in the right data area */
1906 data_end = leaf_data_end(root, right);
1907 memmove_extent_buffer(right,
1908 btrfs_leaf_data(right) + data_end - push_space,
1909 btrfs_leaf_data(right) + data_end,
1910 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1912 /* copy from the left data area */
1913 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1914 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1915 btrfs_leaf_data(left) + leaf_data_end(root, left),
1918 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1919 btrfs_item_nr_offset(0),
1920 right_nritems * sizeof(struct btrfs_item));
1922 /* copy the items from left to right */
1923 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1924 btrfs_item_nr_offset(left_nritems - push_items),
1925 push_items * sizeof(struct btrfs_item));
1927 /* update the item pointers */
1928 right_nritems += push_items;
1929 btrfs_set_header_nritems(right, right_nritems);
1930 push_space = BTRFS_LEAF_DATA_SIZE(root);
1931 for (i = 0; i < right_nritems; i++) {
1932 item = btrfs_item_nr(right, i);
1933 if (!right->map_token) {
1934 map_extent_buffer(right, (unsigned long)item,
1935 sizeof(struct btrfs_item),
1936 &right->map_token, &right->kaddr,
1937 &right->map_start, &right->map_len,
1940 push_space -= btrfs_item_size(right, item);
1941 btrfs_set_item_offset(right, item, push_space);
1944 if (right->map_token) {
1945 unmap_extent_buffer(right, right->map_token, KM_USER1);
1946 right->map_token = NULL;
1948 left_nritems -= push_items;
1949 btrfs_set_header_nritems(left, left_nritems);
1952 btrfs_mark_buffer_dirty(left);
1953 btrfs_mark_buffer_dirty(right);
1955 btrfs_item_key(right, &disk_key, 0);
1956 btrfs_set_node_key(upper, &disk_key, slot + 1);
1957 btrfs_mark_buffer_dirty(upper);
1959 /* then fixup the leaf pointer in the path */
1960 if (path->slots[0] >= left_nritems) {
1961 path->slots[0] -= left_nritems;
1962 if (btrfs_header_nritems(path->nodes[0]) == 0)
1963 clean_tree_block(trans, root, path->nodes[0]);
1964 btrfs_tree_unlock(path->nodes[0]);
1965 free_extent_buffer(path->nodes[0]);
1966 path->nodes[0] = right;
1967 path->slots[1] += 1;
1969 btrfs_tree_unlock(right);
1970 free_extent_buffer(right);
1975 btrfs_tree_unlock(right);
1976 free_extent_buffer(right);
1981 * push some data in the path leaf to the left, trying to free up at
1982 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1984 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1985 *root, struct btrfs_path *path, int data_size,
1988 struct btrfs_disk_key disk_key;
1989 struct extent_buffer *right = path->nodes[0];
1990 struct extent_buffer *left;
1996 struct btrfs_item *item;
1997 u32 old_left_nritems;
2003 u32 old_left_item_size;
2005 slot = path->slots[1];
2008 if (!path->nodes[1])
2011 right_nritems = btrfs_header_nritems(right);
2012 if (right_nritems == 0) {
2016 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
2018 left = read_node_slot(root, path->nodes[1], slot - 1);
2019 btrfs_tree_lock(left);
2020 free_space = btrfs_leaf_free_space(root, left);
2021 if (free_space < data_size + sizeof(struct btrfs_item)) {
2026 /* cow and double check */
2027 ret = btrfs_cow_block(trans, root, left,
2028 path->nodes[1], slot - 1, &left);
2030 /* we hit -ENOSPC, but it isn't fatal here */
2035 free_space = btrfs_leaf_free_space(root, left);
2036 if (free_space < data_size + sizeof(struct btrfs_item)) {
2044 nr = right_nritems - 1;
2046 for (i = 0; i < nr; i++) {
2047 item = btrfs_item_nr(right, i);
2048 if (!right->map_token) {
2049 map_extent_buffer(right, (unsigned long)item,
2050 sizeof(struct btrfs_item),
2051 &right->map_token, &right->kaddr,
2052 &right->map_start, &right->map_len,
2056 if (path->slots[0] == i)
2057 push_space += data_size + sizeof(*item);
2059 this_item_size = btrfs_item_size(right, item);
2060 if (this_item_size + sizeof(*item) + push_space > free_space)
2064 push_space += this_item_size + sizeof(*item);
2067 if (right->map_token) {
2068 unmap_extent_buffer(right, right->map_token, KM_USER1);
2069 right->map_token = NULL;
2072 if (push_items == 0) {
2076 if (!empty && push_items == btrfs_header_nritems(right))
2079 /* push data from right to left */
2080 copy_extent_buffer(left, right,
2081 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2082 btrfs_item_nr_offset(0),
2083 push_items * sizeof(struct btrfs_item));
2085 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2086 btrfs_item_offset_nr(right, push_items -1);
2088 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2089 leaf_data_end(root, left) - push_space,
2090 btrfs_leaf_data(right) +
2091 btrfs_item_offset_nr(right, push_items - 1),
2093 old_left_nritems = btrfs_header_nritems(left);
2094 BUG_ON(old_left_nritems < 0);
2096 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2097 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2100 item = btrfs_item_nr(left, i);
2101 if (!left->map_token) {
2102 map_extent_buffer(left, (unsigned long)item,
2103 sizeof(struct btrfs_item),
2104 &left->map_token, &left->kaddr,
2105 &left->map_start, &left->map_len,
2109 ioff = btrfs_item_offset(left, item);
2110 btrfs_set_item_offset(left, item,
2111 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2113 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2114 if (left->map_token) {
2115 unmap_extent_buffer(left, left->map_token, KM_USER1);
2116 left->map_token = NULL;
2119 /* fixup right node */
2120 if (push_items > right_nritems) {
2121 printk("push items %d nr %u\n", push_items, right_nritems);
2125 if (push_items < right_nritems) {
2126 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2127 leaf_data_end(root, right);
2128 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2129 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2130 btrfs_leaf_data(right) +
2131 leaf_data_end(root, right), push_space);
2133 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2134 btrfs_item_nr_offset(push_items),
2135 (btrfs_header_nritems(right) - push_items) *
2136 sizeof(struct btrfs_item));
2138 right_nritems -= push_items;
2139 btrfs_set_header_nritems(right, right_nritems);
2140 push_space = BTRFS_LEAF_DATA_SIZE(root);
2141 for (i = 0; i < right_nritems; i++) {
2142 item = btrfs_item_nr(right, i);
2144 if (!right->map_token) {
2145 map_extent_buffer(right, (unsigned long)item,
2146 sizeof(struct btrfs_item),
2147 &right->map_token, &right->kaddr,
2148 &right->map_start, &right->map_len,
2152 push_space = push_space - btrfs_item_size(right, item);
2153 btrfs_set_item_offset(right, item, push_space);
2155 if (right->map_token) {
2156 unmap_extent_buffer(right, right->map_token, KM_USER1);
2157 right->map_token = NULL;
2160 btrfs_mark_buffer_dirty(left);
2162 btrfs_mark_buffer_dirty(right);
2164 btrfs_item_key(right, &disk_key, 0);
2165 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2169 /* then fixup the leaf pointer in the path */
2170 if (path->slots[0] < push_items) {
2171 path->slots[0] += old_left_nritems;
2172 if (btrfs_header_nritems(path->nodes[0]) == 0)
2173 clean_tree_block(trans, root, path->nodes[0]);
2174 btrfs_tree_unlock(path->nodes[0]);
2175 free_extent_buffer(path->nodes[0]);
2176 path->nodes[0] = left;
2177 path->slots[1] -= 1;
2179 btrfs_tree_unlock(left);
2180 free_extent_buffer(left);
2181 path->slots[0] -= push_items;
2183 BUG_ON(path->slots[0] < 0);
2186 btrfs_tree_unlock(left);
2187 free_extent_buffer(left);
2192 * split the path's leaf in two, making sure there is at least data_size
2193 * available for the resulting leaf level of the path.
2195 * returns 0 if all went well and < 0 on failure.
2197 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
2198 *root, struct btrfs_key *ins_key,
2199 struct btrfs_path *path, int data_size, int extend)
2202 struct extent_buffer *l;
2206 struct extent_buffer *right;
2207 int space_needed = data_size + sizeof(struct btrfs_item);
2214 int num_doubles = 0;
2215 struct btrfs_disk_key disk_key;
2218 space_needed = data_size;
2221 root_gen = trans->transid;
2225 /* first try to make some room by pushing left and right */
2226 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
2227 wret = push_leaf_right(trans, root, path, data_size, 0);
2232 wret = push_leaf_left(trans, root, path, data_size, 0);
2238 /* did the pushes work? */
2239 if (btrfs_leaf_free_space(root, l) >= space_needed)
2243 if (!path->nodes[1]) {
2244 ret = insert_new_root(trans, root, path, 1);
2251 slot = path->slots[0];
2252 nritems = btrfs_header_nritems(l);
2253 mid = (nritems + 1)/ 2;
2255 btrfs_item_key(l, &disk_key, 0);
2257 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2258 root->root_key.objectid,
2259 root_gen, disk_key.objectid, 0,
2261 if (IS_ERR(right)) {
2263 return PTR_ERR(right);
2266 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2267 btrfs_set_header_bytenr(right, right->start);
2268 btrfs_set_header_generation(right, trans->transid);
2269 btrfs_set_header_owner(right, root->root_key.objectid);
2270 btrfs_set_header_level(right, 0);
2271 write_extent_buffer(right, root->fs_info->fsid,
2272 (unsigned long)btrfs_header_fsid(right),
2275 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2276 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2280 leaf_space_used(l, mid, nritems - mid) + space_needed >
2281 BTRFS_LEAF_DATA_SIZE(root)) {
2282 if (slot >= nritems) {
2283 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2284 btrfs_set_header_nritems(right, 0);
2285 wret = insert_ptr(trans, root, path,
2286 &disk_key, right->start,
2287 path->slots[1] + 1, 1);
2291 btrfs_tree_unlock(path->nodes[0]);
2292 free_extent_buffer(path->nodes[0]);
2293 path->nodes[0] = right;
2295 path->slots[1] += 1;
2296 btrfs_mark_buffer_dirty(right);
2300 if (mid != nritems &&
2301 leaf_space_used(l, mid, nritems - mid) +
2302 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2307 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2308 BTRFS_LEAF_DATA_SIZE(root)) {
2309 if (!extend && slot == 0) {
2310 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2311 btrfs_set_header_nritems(right, 0);
2312 wret = insert_ptr(trans, root, path,
2318 btrfs_tree_unlock(path->nodes[0]);
2319 free_extent_buffer(path->nodes[0]);
2320 path->nodes[0] = right;
2322 if (path->slots[1] == 0) {
2323 wret = fixup_low_keys(trans, root,
2324 path, &disk_key, 1);
2328 btrfs_mark_buffer_dirty(right);
2330 } else if (extend && slot == 0) {
2334 if (mid != nritems &&
2335 leaf_space_used(l, mid, nritems - mid) +
2336 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2342 nritems = nritems - mid;
2343 btrfs_set_header_nritems(right, nritems);
2344 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2346 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2347 btrfs_item_nr_offset(mid),
2348 nritems * sizeof(struct btrfs_item));
2350 copy_extent_buffer(right, l,
2351 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2352 data_copy_size, btrfs_leaf_data(l) +
2353 leaf_data_end(root, l), data_copy_size);
2355 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2356 btrfs_item_end_nr(l, mid);
2358 for (i = 0; i < nritems; i++) {
2359 struct btrfs_item *item = btrfs_item_nr(right, i);
2362 if (!right->map_token) {
2363 map_extent_buffer(right, (unsigned long)item,
2364 sizeof(struct btrfs_item),
2365 &right->map_token, &right->kaddr,
2366 &right->map_start, &right->map_len,
2370 ioff = btrfs_item_offset(right, item);
2371 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2374 if (right->map_token) {
2375 unmap_extent_buffer(right, right->map_token, KM_USER1);
2376 right->map_token = NULL;
2379 btrfs_set_header_nritems(l, mid);
2381 btrfs_item_key(right, &disk_key, 0);
2382 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2383 path->slots[1] + 1, 1);
2387 btrfs_mark_buffer_dirty(right);
2388 btrfs_mark_buffer_dirty(l);
2389 BUG_ON(path->slots[0] != slot);
2392 btrfs_tree_unlock(path->nodes[0]);
2393 free_extent_buffer(path->nodes[0]);
2394 path->nodes[0] = right;
2395 path->slots[0] -= mid;
2396 path->slots[1] += 1;
2398 btrfs_tree_unlock(right);
2399 free_extent_buffer(right);
2402 BUG_ON(path->slots[0] < 0);
2405 BUG_ON(num_doubles != 0);
2412 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2413 struct btrfs_root *root,
2414 struct btrfs_path *path,
2415 u32 new_size, int from_end)
2420 struct extent_buffer *leaf;
2421 struct btrfs_item *item;
2423 unsigned int data_end;
2424 unsigned int old_data_start;
2425 unsigned int old_size;
2426 unsigned int size_diff;
2429 slot_orig = path->slots[0];
2430 leaf = path->nodes[0];
2431 slot = path->slots[0];
2433 old_size = btrfs_item_size_nr(leaf, slot);
2434 if (old_size == new_size)
2437 nritems = btrfs_header_nritems(leaf);
2438 data_end = leaf_data_end(root, leaf);
2440 old_data_start = btrfs_item_offset_nr(leaf, slot);
2442 size_diff = old_size - new_size;
2445 BUG_ON(slot >= nritems);
2448 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2450 /* first correct the data pointers */
2451 for (i = slot; i < nritems; i++) {
2453 item = btrfs_item_nr(leaf, i);
2455 if (!leaf->map_token) {
2456 map_extent_buffer(leaf, (unsigned long)item,
2457 sizeof(struct btrfs_item),
2458 &leaf->map_token, &leaf->kaddr,
2459 &leaf->map_start, &leaf->map_len,
2463 ioff = btrfs_item_offset(leaf, item);
2464 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2467 if (leaf->map_token) {
2468 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2469 leaf->map_token = NULL;
2472 /* shift the data */
2474 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2475 data_end + size_diff, btrfs_leaf_data(leaf) +
2476 data_end, old_data_start + new_size - data_end);
2478 struct btrfs_disk_key disk_key;
2481 btrfs_item_key(leaf, &disk_key, slot);
2483 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2485 struct btrfs_file_extent_item *fi;
2487 fi = btrfs_item_ptr(leaf, slot,
2488 struct btrfs_file_extent_item);
2489 fi = (struct btrfs_file_extent_item *)(
2490 (unsigned long)fi - size_diff);
2492 if (btrfs_file_extent_type(leaf, fi) ==
2493 BTRFS_FILE_EXTENT_INLINE) {
2494 ptr = btrfs_item_ptr_offset(leaf, slot);
2495 memmove_extent_buffer(leaf, ptr,
2497 offsetof(struct btrfs_file_extent_item,
2502 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2503 data_end + size_diff, btrfs_leaf_data(leaf) +
2504 data_end, old_data_start - data_end);
2506 offset = btrfs_disk_key_offset(&disk_key);
2507 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2508 btrfs_set_item_key(leaf, &disk_key, slot);
2510 fixup_low_keys(trans, root, path, &disk_key, 1);
2513 item = btrfs_item_nr(leaf, slot);
2514 btrfs_set_item_size(leaf, item, new_size);
2515 btrfs_mark_buffer_dirty(leaf);
2518 if (btrfs_leaf_free_space(root, leaf) < 0) {
2519 btrfs_print_leaf(root, leaf);
2525 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2526 struct btrfs_root *root, struct btrfs_path *path,
2532 struct extent_buffer *leaf;
2533 struct btrfs_item *item;
2535 unsigned int data_end;
2536 unsigned int old_data;
2537 unsigned int old_size;
2540 slot_orig = path->slots[0];
2541 leaf = path->nodes[0];
2543 nritems = btrfs_header_nritems(leaf);
2544 data_end = leaf_data_end(root, leaf);
2546 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2547 btrfs_print_leaf(root, leaf);
2550 slot = path->slots[0];
2551 old_data = btrfs_item_end_nr(leaf, slot);
2554 if (slot >= nritems) {
2555 btrfs_print_leaf(root, leaf);
2556 printk("slot %d too large, nritems %d\n", slot, nritems);
2561 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2563 /* first correct the data pointers */
2564 for (i = slot; i < nritems; i++) {
2566 item = btrfs_item_nr(leaf, i);
2568 if (!leaf->map_token) {
2569 map_extent_buffer(leaf, (unsigned long)item,
2570 sizeof(struct btrfs_item),
2571 &leaf->map_token, &leaf->kaddr,
2572 &leaf->map_start, &leaf->map_len,
2575 ioff = btrfs_item_offset(leaf, item);
2576 btrfs_set_item_offset(leaf, item, ioff - data_size);
2579 if (leaf->map_token) {
2580 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2581 leaf->map_token = NULL;
2584 /* shift the data */
2585 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2586 data_end - data_size, btrfs_leaf_data(leaf) +
2587 data_end, old_data - data_end);
2589 data_end = old_data;
2590 old_size = btrfs_item_size_nr(leaf, slot);
2591 item = btrfs_item_nr(leaf, slot);
2592 btrfs_set_item_size(leaf, item, old_size + data_size);
2593 btrfs_mark_buffer_dirty(leaf);
2596 if (btrfs_leaf_free_space(root, leaf) < 0) {
2597 btrfs_print_leaf(root, leaf);
2604 * Given a key and some data, insert an item into the tree.
2605 * This does all the path init required, making room in the tree if needed.
2607 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2608 struct btrfs_root *root,
2609 struct btrfs_path *path,
2610 struct btrfs_key *cpu_key, u32 *data_size,
2613 struct extent_buffer *leaf;
2614 struct btrfs_item *item;
2622 unsigned int data_end;
2623 struct btrfs_disk_key disk_key;
2625 for (i = 0; i < nr; i++) {
2626 total_data += data_size[i];
2629 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2630 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2637 slot_orig = path->slots[0];
2638 leaf = path->nodes[0];
2640 nritems = btrfs_header_nritems(leaf);
2641 data_end = leaf_data_end(root, leaf);
2643 if (btrfs_leaf_free_space(root, leaf) <
2644 sizeof(struct btrfs_item) + total_size) {
2645 btrfs_print_leaf(root, leaf);
2646 printk("not enough freespace need %u have %d\n",
2647 total_size, btrfs_leaf_free_space(root, leaf));
2651 slot = path->slots[0];
2654 if (slot != nritems) {
2656 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2658 if (old_data < data_end) {
2659 btrfs_print_leaf(root, leaf);
2660 printk("slot %d old_data %d data_end %d\n",
2661 slot, old_data, data_end);
2665 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2667 /* first correct the data pointers */
2668 WARN_ON(leaf->map_token);
2669 for (i = slot; i < nritems; i++) {
2672 item = btrfs_item_nr(leaf, i);
2673 if (!leaf->map_token) {
2674 map_extent_buffer(leaf, (unsigned long)item,
2675 sizeof(struct btrfs_item),
2676 &leaf->map_token, &leaf->kaddr,
2677 &leaf->map_start, &leaf->map_len,
2681 ioff = btrfs_item_offset(leaf, item);
2682 btrfs_set_item_offset(leaf, item, ioff - total_data);
2684 if (leaf->map_token) {
2685 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2686 leaf->map_token = NULL;
2689 /* shift the items */
2690 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2691 btrfs_item_nr_offset(slot),
2692 (nritems - slot) * sizeof(struct btrfs_item));
2694 /* shift the data */
2695 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2696 data_end - total_data, btrfs_leaf_data(leaf) +
2697 data_end, old_data - data_end);
2698 data_end = old_data;
2701 /* setup the item for the new data */
2702 for (i = 0; i < nr; i++) {
2703 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2704 btrfs_set_item_key(leaf, &disk_key, slot + i);
2705 item = btrfs_item_nr(leaf, slot + i);
2706 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2707 data_end -= data_size[i];
2708 btrfs_set_item_size(leaf, item, data_size[i]);
2710 btrfs_set_header_nritems(leaf, nritems + nr);
2711 btrfs_mark_buffer_dirty(leaf);
2715 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2716 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2719 if (btrfs_leaf_free_space(root, leaf) < 0) {
2720 btrfs_print_leaf(root, leaf);
2728 * Given a key and some data, insert an item into the tree.
2729 * This does all the path init required, making room in the tree if needed.
2731 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2732 *root, struct btrfs_key *cpu_key, void *data, u32
2736 struct btrfs_path *path;
2737 struct extent_buffer *leaf;
2740 path = btrfs_alloc_path();
2742 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2744 leaf = path->nodes[0];
2745 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2746 write_extent_buffer(leaf, data, ptr, data_size);
2747 btrfs_mark_buffer_dirty(leaf);
2749 btrfs_free_path(path);
2754 * delete the pointer from a given node.
2756 * If the delete empties a node, the node is removed from the tree,
2757 * continuing all the way the root if required. The root is converted into
2758 * a leaf if all the nodes are emptied.
2760 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2761 struct btrfs_path *path, int level, int slot)
2763 struct extent_buffer *parent = path->nodes[level];
2768 nritems = btrfs_header_nritems(parent);
2769 if (slot != nritems -1) {
2770 memmove_extent_buffer(parent,
2771 btrfs_node_key_ptr_offset(slot),
2772 btrfs_node_key_ptr_offset(slot + 1),
2773 sizeof(struct btrfs_key_ptr) *
2774 (nritems - slot - 1));
2777 btrfs_set_header_nritems(parent, nritems);
2778 if (nritems == 0 && parent == root->node) {
2779 BUG_ON(btrfs_header_level(root->node) != 1);
2780 /* just turn the root into a leaf and break */
2781 btrfs_set_header_level(root->node, 0);
2782 } else if (slot == 0) {
2783 struct btrfs_disk_key disk_key;
2785 btrfs_node_key(parent, &disk_key, 0);
2786 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2790 btrfs_mark_buffer_dirty(parent);
2795 * delete the item at the leaf level in path. If that empties
2796 * the leaf, remove it from the tree
2798 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2799 struct btrfs_path *path, int slot, int nr)
2801 struct extent_buffer *leaf;
2802 struct btrfs_item *item;
2810 leaf = path->nodes[0];
2811 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2813 for (i = 0; i < nr; i++)
2814 dsize += btrfs_item_size_nr(leaf, slot + i);
2816 nritems = btrfs_header_nritems(leaf);
2818 if (slot + nr != nritems) {
2820 int data_end = leaf_data_end(root, leaf);
2822 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2824 btrfs_leaf_data(leaf) + data_end,
2825 last_off - data_end);
2827 for (i = slot + nr; i < nritems; i++) {
2830 item = btrfs_item_nr(leaf, i);
2831 if (!leaf->map_token) {
2832 map_extent_buffer(leaf, (unsigned long)item,
2833 sizeof(struct btrfs_item),
2834 &leaf->map_token, &leaf->kaddr,
2835 &leaf->map_start, &leaf->map_len,
2838 ioff = btrfs_item_offset(leaf, item);
2839 btrfs_set_item_offset(leaf, item, ioff + dsize);
2842 if (leaf->map_token) {
2843 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2844 leaf->map_token = NULL;
2847 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2848 btrfs_item_nr_offset(slot + nr),
2849 sizeof(struct btrfs_item) *
2850 (nritems - slot - nr));
2852 btrfs_set_header_nritems(leaf, nritems - nr);
2855 /* delete the leaf if we've emptied it */
2857 if (leaf == root->node) {
2858 btrfs_set_header_level(leaf, 0);
2860 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2861 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2864 wret = btrfs_free_extent(trans, root,
2865 leaf->start, leaf->len,
2866 btrfs_header_owner(path->nodes[1]),
2872 int used = leaf_space_used(leaf, 0, nritems);
2874 struct btrfs_disk_key disk_key;
2876 btrfs_item_key(leaf, &disk_key, 0);
2877 wret = fixup_low_keys(trans, root, path,
2883 /* delete the leaf if it is mostly empty */
2884 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2885 /* push_leaf_left fixes the path.
2886 * make sure the path still points to our leaf
2887 * for possible call to del_ptr below
2889 slot = path->slots[1];
2890 extent_buffer_get(leaf);
2892 wret = push_leaf_left(trans, root, path, 1, 1);
2893 if (wret < 0 && wret != -ENOSPC)
2896 if (path->nodes[0] == leaf &&
2897 btrfs_header_nritems(leaf)) {
2898 wret = push_leaf_right(trans, root, path, 1, 1);
2899 if (wret < 0 && wret != -ENOSPC)
2903 if (btrfs_header_nritems(leaf) == 0) {
2905 u64 bytenr = leaf->start;
2906 u32 blocksize = leaf->len;
2908 root_gen = btrfs_header_generation(
2911 wret = del_ptr(trans, root, path, 1, slot);
2915 free_extent_buffer(leaf);
2916 wret = btrfs_free_extent(trans, root, bytenr,
2918 btrfs_header_owner(path->nodes[1]),
2923 /* if we're still in the path, make sure
2924 * we're dirty. Otherwise, one of the
2925 * push_leaf functions must have already
2926 * dirtied this buffer
2928 if (path->nodes[0] == leaf)
2929 btrfs_mark_buffer_dirty(leaf);
2930 free_extent_buffer(leaf);
2933 btrfs_mark_buffer_dirty(leaf);
2940 * search the tree again to find a leaf with lesser keys
2941 * returns 0 if it found something or 1 if there are no lesser leaves.
2942 * returns < 0 on io errors.
2944 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2946 struct btrfs_key key;
2947 struct btrfs_disk_key found_key;
2950 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
2954 else if (key.type > 0)
2956 else if (key.objectid > 0)
2961 btrfs_release_path(root, path);
2962 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2965 btrfs_item_key(path->nodes[0], &found_key, 0);
2966 ret = comp_keys(&found_key, &key);
2973 * A helper function to walk down the tree starting at min_key, and looking
2974 * for nodes or leaves that are either in cache or have a minimum
2975 * transaction id. This is used by the btree defrag code, but could
2976 * also be used to search for blocks that have changed since a given
2979 * This does not cow, but it does stuff the starting key it finds back
2980 * into min_key, so you can call btrfs_search_slot with cow=1 on the
2981 * key and get a writable path.
2983 * This does lock as it descends, and path->keep_locks should be set
2984 * to 1 by the caller.
2986 * This honors path->lowest_level to prevent descent past a given level
2989 * returns zero if something useful was found, < 0 on error and 1 if there
2990 * was nothing in the tree that matched the search criteria.
2992 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
2993 struct btrfs_path *path, int cache_only,
2996 struct extent_buffer *cur;
2997 struct btrfs_key found_key;
3004 cur = btrfs_lock_root_node(root);
3005 level = btrfs_header_level(cur);
3006 path->nodes[level] = cur;
3007 path->locks[level] = 1;
3009 if (btrfs_header_generation(cur) < min_trans) {
3014 nritems = btrfs_header_nritems(cur);
3015 level = btrfs_header_level(cur);
3016 bin_search(cur, min_key, level, &slot);
3018 /* at level = 0, we're done, setup the path and exit */
3021 path->slots[level] = slot;
3022 btrfs_item_key_to_cpu(cur, &found_key, slot);
3026 * check this node pointer against the cache_only and
3027 * min_trans parameters. If it isn't in cache or is too
3028 * old, skip to the next one.
3030 while(slot < nritems) {
3033 struct extent_buffer *tmp;
3034 blockptr = btrfs_node_blockptr(cur, slot);
3035 gen = btrfs_node_ptr_generation(cur, slot);
3036 if (gen < min_trans) {
3043 tmp = btrfs_find_tree_block(root, blockptr,
3044 btrfs_level_size(root, level - 1));
3046 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
3047 free_extent_buffer(tmp);
3051 free_extent_buffer(tmp);
3055 * we didn't find a candidate key in this node, walk forward
3056 * and find another one
3058 if (slot >= nritems) {
3059 ret = btrfs_find_next_key(root, path, min_key, level,
3060 cache_only, min_trans);
3062 btrfs_release_path(root, path);
3068 /* save our key for returning back */
3069 btrfs_node_key_to_cpu(cur, &found_key, slot);
3070 path->slots[level] = slot;
3071 if (level == path->lowest_level) {
3073 unlock_up(path, level, 1);
3076 cur = read_node_slot(root, cur, slot);
3078 btrfs_tree_lock(cur);
3079 path->locks[level - 1] = 1;
3080 path->nodes[level - 1] = cur;
3081 unlock_up(path, level, 1);
3085 memcpy(min_key, &found_key, sizeof(found_key));
3090 * this is similar to btrfs_next_leaf, but does not try to preserve
3091 * and fixup the path. It looks for and returns the next key in the
3092 * tree based on the current path and the cache_only and min_trans
3095 * 0 is returned if another key is found, < 0 if there are any errors
3096 * and 1 is returned if there are no higher keys in the tree
3098 * path->keep_locks should be set to 1 on the search made before
3099 * calling this function.
3101 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
3102 struct btrfs_key *key, int lowest_level,
3103 int cache_only, u64 min_trans)
3105 int level = lowest_level;
3107 struct extent_buffer *c;
3109 while(level < BTRFS_MAX_LEVEL) {
3110 if (!path->nodes[level])
3113 slot = path->slots[level] + 1;
3114 c = path->nodes[level];
3116 if (slot >= btrfs_header_nritems(c)) {
3118 if (level == BTRFS_MAX_LEVEL) {
3124 btrfs_item_key_to_cpu(c, key, slot);
3126 u64 blockptr = btrfs_node_blockptr(c, slot);
3127 u64 gen = btrfs_node_ptr_generation(c, slot);
3130 struct extent_buffer *cur;
3131 cur = btrfs_find_tree_block(root, blockptr,
3132 btrfs_level_size(root, level - 1));
3133 if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
3136 free_extent_buffer(cur);
3139 free_extent_buffer(cur);
3141 if (gen < min_trans) {
3145 btrfs_node_key_to_cpu(c, key, slot);
3153 * search the tree again to find a leaf with greater keys
3154 * returns 0 if it found something or 1 if there are no greater leaves.
3155 * returns < 0 on io errors.
3157 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
3161 struct extent_buffer *c;
3162 struct extent_buffer *next = NULL;
3163 struct btrfs_key key;
3167 nritems = btrfs_header_nritems(path->nodes[0]);
3172 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
3174 btrfs_release_path(root, path);
3175 path->keep_locks = 1;
3176 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3177 path->keep_locks = 0;
3182 nritems = btrfs_header_nritems(path->nodes[0]);
3184 * by releasing the path above we dropped all our locks. A balance
3185 * could have added more items next to the key that used to be
3186 * at the very end of the block. So, check again here and
3187 * advance the path if there are now more items available.
3189 if (nritems > 0 && path->slots[0] < nritems - 1) {
3194 while(level < BTRFS_MAX_LEVEL) {
3195 if (!path->nodes[level])
3198 slot = path->slots[level] + 1;
3199 c = path->nodes[level];
3200 if (slot >= btrfs_header_nritems(c)) {
3202 if (level == BTRFS_MAX_LEVEL) {
3209 btrfs_tree_unlock(next);
3210 free_extent_buffer(next);
3213 if (level == 1 && path->locks[1] && path->reada)
3214 reada_for_search(root, path, level, slot, 0);
3216 next = read_node_slot(root, c, slot);
3217 if (!path->skip_locking) {
3218 WARN_ON(!btrfs_tree_locked(c));
3219 btrfs_tree_lock(next);
3223 path->slots[level] = slot;
3226 c = path->nodes[level];
3227 if (path->locks[level])
3228 btrfs_tree_unlock(c);
3229 free_extent_buffer(c);
3230 path->nodes[level] = next;
3231 path->slots[level] = 0;
3232 if (!path->skip_locking)
3233 path->locks[level] = 1;
3236 if (level == 1 && path->locks[1] && path->reada)
3237 reada_for_search(root, path, level, slot, 0);
3238 next = read_node_slot(root, next, 0);
3239 if (!path->skip_locking) {
3240 WARN_ON(!btrfs_tree_locked(path->nodes[level]));
3241 btrfs_tree_lock(next);
3245 unlock_up(path, 0, 1);
3250 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
3251 * searching until it gets past min_objectid or finds an item of 'type'
3253 * returns 0 if something is found, 1 if nothing was found and < 0 on error
3255 int btrfs_previous_item(struct btrfs_root *root,
3256 struct btrfs_path *path, u64 min_objectid,
3259 struct btrfs_key found_key;
3260 struct extent_buffer *leaf;
3264 if (path->slots[0] == 0) {
3265 ret = btrfs_prev_leaf(root, path);
3271 leaf = path->nodes[0];
3272 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3273 if (found_key.type == type)