2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size, int extend);
30 static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src, int empty);
33 static int balance_node_right(struct btrfs_trans_handle *trans,
34 struct btrfs_root *root,
35 struct extent_buffer *dst_buf,
36 struct extent_buffer *src_buf);
37 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
40 inline void btrfs_init_path(struct btrfs_path *p)
42 memset(p, 0, sizeof(*p));
45 struct btrfs_path *btrfs_alloc_path(void)
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
50 btrfs_init_path(path);
56 void btrfs_free_path(struct btrfs_path *p)
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
62 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
68 free_extent_buffer(p->nodes[i]);
70 memset(p, 0, sizeof(*p));
73 static void add_root_to_dirty_list(struct btrfs_root *root)
75 if (root->track_dirty && list_empty(&root->dirty_list)) {
76 list_add(&root->dirty_list,
77 &root->fs_info->dirty_cowonly_roots);
81 int btrfs_copy_root(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root,
83 struct extent_buffer *buf,
84 struct extent_buffer **cow_ret, u64 new_root_objectid)
86 struct extent_buffer *cow;
90 struct btrfs_key first_key;
91 struct btrfs_root *new_root;
93 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
97 memcpy(new_root, root, sizeof(*new_root));
98 new_root->root_key.objectid = new_root_objectid;
100 WARN_ON(root->ref_cows && trans->transid !=
101 root->fs_info->running_transaction->transid);
102 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
104 level = btrfs_header_level(buf);
105 nritems = btrfs_header_nritems(buf);
108 btrfs_item_key_to_cpu(buf, &first_key, 0);
110 btrfs_node_key_to_cpu(buf, &first_key, 0);
112 first_key.objectid = 0;
114 cow = __btrfs_alloc_free_block(trans, new_root, buf->len,
116 trans->transid, first_key.objectid,
117 level, buf->start, 0);
123 copy_extent_buffer(cow, buf, 0, 0, cow->len);
124 btrfs_set_header_bytenr(cow, cow->start);
125 btrfs_set_header_generation(cow, trans->transid);
126 btrfs_set_header_owner(cow, new_root_objectid);
127 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
129 WARN_ON(btrfs_header_generation(buf) > trans->transid);
130 ret = btrfs_inc_ref(trans, new_root, buf);
136 btrfs_mark_buffer_dirty(cow);
141 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
142 struct btrfs_root *root,
143 struct extent_buffer *buf,
144 struct extent_buffer *parent, int parent_slot,
145 struct extent_buffer **cow_ret,
146 u64 search_start, u64 empty_size)
149 struct extent_buffer *cow;
152 int different_trans = 0;
154 struct btrfs_key first_key;
156 if (root->ref_cows) {
157 root_gen = trans->transid;
161 WARN_ON(root->ref_cows && trans->transid !=
162 root->fs_info->running_transaction->transid);
163 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
165 level = btrfs_header_level(buf);
166 nritems = btrfs_header_nritems(buf);
169 btrfs_item_key_to_cpu(buf, &first_key, 0);
171 btrfs_node_key_to_cpu(buf, &first_key, 0);
173 first_key.objectid = 0;
175 cow = __btrfs_alloc_free_block(trans, root, buf->len,
176 root->root_key.objectid,
177 root_gen, first_key.objectid, level,
178 search_start, empty_size);
182 copy_extent_buffer(cow, buf, 0, 0, cow->len);
183 btrfs_set_header_bytenr(cow, cow->start);
184 btrfs_set_header_generation(cow, trans->transid);
185 btrfs_set_header_owner(cow, root->root_key.objectid);
186 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
188 WARN_ON(btrfs_header_generation(buf) > trans->transid);
189 if (btrfs_header_generation(buf) != trans->transid) {
191 ret = btrfs_inc_ref(trans, root, buf);
195 clean_tree_block(trans, root, buf);
198 if (buf == root->node) {
199 root_gen = btrfs_header_generation(buf);
201 extent_buffer_get(cow);
202 if (buf != root->commit_root) {
203 btrfs_free_extent(trans, root, buf->start,
204 buf->len, root->root_key.objectid,
207 free_extent_buffer(buf);
208 add_root_to_dirty_list(root);
210 root_gen = btrfs_header_generation(parent);
211 btrfs_set_node_blockptr(parent, parent_slot,
213 WARN_ON(trans->transid == 0);
214 btrfs_set_node_ptr_generation(parent, parent_slot,
216 btrfs_mark_buffer_dirty(parent);
217 WARN_ON(btrfs_header_generation(parent) != trans->transid);
218 btrfs_free_extent(trans, root, buf->start, buf->len,
219 btrfs_header_owner(parent), root_gen,
222 free_extent_buffer(buf);
223 btrfs_mark_buffer_dirty(cow);
228 int btrfs_cow_block(struct btrfs_trans_handle *trans,
229 struct btrfs_root *root, struct extent_buffer *buf,
230 struct extent_buffer *parent, int parent_slot,
231 struct extent_buffer **cow_ret)
237 if (trans->transaction != root->fs_info->running_transaction) {
238 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
239 root->fs_info->running_transaction->transid);
242 if (trans->transid != root->fs_info->generation) {
243 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
244 root->fs_info->generation);
248 header_trans = btrfs_header_generation(buf);
249 spin_lock(&root->fs_info->hash_lock);
250 if (header_trans == trans->transid &&
251 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
253 spin_unlock(&root->fs_info->hash_lock);
256 spin_unlock(&root->fs_info->hash_lock);
257 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
258 ret = __btrfs_cow_block(trans, root, buf, parent,
259 parent_slot, cow_ret, search_start, 0);
263 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
265 if (blocknr < other && other - (blocknr + blocksize) < 32768)
267 if (blocknr > other && blocknr - (other + blocksize) < 32768)
273 * compare two keys in a memcmp fashion
275 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
279 btrfs_disk_key_to_cpu(&k1, disk);
281 if (k1.objectid > k2->objectid)
283 if (k1.objectid < k2->objectid)
285 if (k1.type > k2->type)
287 if (k1.type < k2->type)
289 if (k1.offset > k2->offset)
291 if (k1.offset < k2->offset)
297 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
298 struct btrfs_root *root, struct extent_buffer *parent,
299 int start_slot, int cache_only, u64 *last_ret,
300 struct btrfs_key *progress)
302 struct extent_buffer *cur;
303 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);
358 last_block = blocknr;
361 other = btrfs_node_blockptr(parent, i - 1);
362 close = close_blocks(blocknr, other, blocksize);
364 if (close && i < end_slot - 2) {
365 other = btrfs_node_blockptr(parent, i + 1);
366 close = close_blocks(blocknr, other, blocksize);
369 last_block = blocknr;
372 if (parent->map_token) {
373 unmap_extent_buffer(parent, parent->map_token,
375 parent->map_token = NULL;
378 cur = btrfs_find_tree_block(root, blocknr, blocksize);
380 uptodate = btrfs_buffer_uptodate(cur);
383 if (!cur || !uptodate) {
385 free_extent_buffer(cur);
389 cur = read_tree_block(root, blocknr,
391 } else if (!uptodate) {
392 btrfs_read_buffer(cur);
395 if (search_start == 0)
396 search_start = last_block;
398 btrfs_verify_block_csum(root, cur);
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;
423 * The leaf data grows from end-to-front in the node.
424 * this returns the address of the start of the last item,
425 * which is the stop of the leaf data stack
427 static inline unsigned int leaf_data_end(struct btrfs_root *root,
428 struct extent_buffer *leaf)
430 u32 nr = btrfs_header_nritems(leaf);
432 return BTRFS_LEAF_DATA_SIZE(root);
433 return btrfs_item_offset_nr(leaf, nr - 1);
436 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
439 struct extent_buffer *parent = NULL;
440 struct extent_buffer *node = path->nodes[level];
441 struct btrfs_disk_key parent_key;
442 struct btrfs_disk_key node_key;
445 struct btrfs_key cpukey;
446 u32 nritems = btrfs_header_nritems(node);
448 if (path->nodes[level + 1])
449 parent = path->nodes[level + 1];
451 slot = path->slots[level];
452 BUG_ON(nritems == 0);
454 parent_slot = path->slots[level + 1];
455 btrfs_node_key(parent, &parent_key, parent_slot);
456 btrfs_node_key(node, &node_key, 0);
457 BUG_ON(memcmp(&parent_key, &node_key,
458 sizeof(struct btrfs_disk_key)));
459 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
460 btrfs_header_bytenr(node));
462 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
464 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
465 btrfs_node_key(node, &node_key, slot);
466 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
468 if (slot < nritems - 1) {
469 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
470 btrfs_node_key(node, &node_key, slot);
471 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
476 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
479 struct extent_buffer *leaf = path->nodes[level];
480 struct extent_buffer *parent = NULL;
482 struct btrfs_key cpukey;
483 struct btrfs_disk_key parent_key;
484 struct btrfs_disk_key leaf_key;
485 int slot = path->slots[0];
487 u32 nritems = btrfs_header_nritems(leaf);
489 if (path->nodes[level + 1])
490 parent = path->nodes[level + 1];
496 parent_slot = path->slots[level + 1];
497 btrfs_node_key(parent, &parent_key, parent_slot);
498 btrfs_item_key(leaf, &leaf_key, 0);
500 BUG_ON(memcmp(&parent_key, &leaf_key,
501 sizeof(struct btrfs_disk_key)));
502 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
503 btrfs_header_bytenr(leaf));
506 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
507 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
508 btrfs_item_key(leaf, &leaf_key, i);
509 if (comp_keys(&leaf_key, &cpukey) >= 0) {
510 btrfs_print_leaf(root, leaf);
511 printk("slot %d offset bad key\n", i);
514 if (btrfs_item_offset_nr(leaf, i) !=
515 btrfs_item_end_nr(leaf, i + 1)) {
516 btrfs_print_leaf(root, leaf);
517 printk("slot %d offset bad\n", i);
521 if (btrfs_item_offset_nr(leaf, i) +
522 btrfs_item_size_nr(leaf, i) !=
523 BTRFS_LEAF_DATA_SIZE(root)) {
524 btrfs_print_leaf(root, leaf);
525 printk("slot %d first offset bad\n", i);
531 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
532 btrfs_print_leaf(root, leaf);
533 printk("slot %d bad size \n", nritems - 1);
538 if (slot != 0 && slot < nritems - 1) {
539 btrfs_item_key(leaf, &leaf_key, slot);
540 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
541 if (comp_keys(&leaf_key, &cpukey) <= 0) {
542 btrfs_print_leaf(root, leaf);
543 printk("slot %d offset bad key\n", slot);
546 if (btrfs_item_offset_nr(leaf, slot - 1) !=
547 btrfs_item_end_nr(leaf, slot)) {
548 btrfs_print_leaf(root, leaf);
549 printk("slot %d offset bad\n", slot);
553 if (slot < nritems - 1) {
554 btrfs_item_key(leaf, &leaf_key, slot);
555 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
556 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
557 if (btrfs_item_offset_nr(leaf, slot) !=
558 btrfs_item_end_nr(leaf, slot + 1)) {
559 btrfs_print_leaf(root, leaf);
560 printk("slot %d offset bad\n", slot);
564 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
565 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
569 static int noinline check_block(struct btrfs_root *root,
570 struct btrfs_path *path, int level)
574 if (btrfs_header_level(path->nodes[level]) != level)
575 printk("warning: bad level %Lu wanted %d found %d\n",
576 path->nodes[level]->start, level,
577 btrfs_header_level(path->nodes[level]));
578 found_start = btrfs_header_bytenr(path->nodes[level]);
579 if (found_start != path->nodes[level]->start) {
580 printk("warning: bad bytentr %Lu found %Lu\n",
581 path->nodes[level]->start, found_start);
584 struct extent_buffer *buf = path->nodes[level];
586 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
587 (unsigned long)btrfs_header_fsid(buf),
589 printk("warning bad block %Lu\n", buf->start);
594 return check_leaf(root, path, level);
595 return check_node(root, path, level);
599 * search for key in the extent_buffer. The items start at offset p,
600 * and they are item_size apart. There are 'max' items in p.
602 * the slot in the array is returned via slot, and it points to
603 * the place where you would insert key if it is not found in
606 * slot may point to max if the key is bigger than all of the keys
608 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
609 int item_size, struct btrfs_key *key,
616 struct btrfs_disk_key *tmp = NULL;
617 struct btrfs_disk_key unaligned;
618 unsigned long offset;
619 char *map_token = NULL;
621 unsigned long map_start = 0;
622 unsigned long map_len = 0;
626 mid = (low + high) / 2;
627 offset = p + mid * item_size;
629 if (!map_token || offset < map_start ||
630 (offset + sizeof(struct btrfs_disk_key)) >
631 map_start + map_len) {
633 unmap_extent_buffer(eb, map_token, KM_USER0);
636 err = map_extent_buffer(eb, offset,
637 sizeof(struct btrfs_disk_key),
639 &map_start, &map_len, KM_USER0);
642 tmp = (struct btrfs_disk_key *)(kaddr + offset -
645 read_extent_buffer(eb, &unaligned,
646 offset, sizeof(unaligned));
651 tmp = (struct btrfs_disk_key *)(kaddr + offset -
654 ret = comp_keys(tmp, key);
663 unmap_extent_buffer(eb, map_token, KM_USER0);
669 unmap_extent_buffer(eb, map_token, KM_USER0);
674 * simple bin_search frontend that does the right thing for
677 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
678 int level, int *slot)
681 return generic_bin_search(eb,
682 offsetof(struct btrfs_leaf, items),
683 sizeof(struct btrfs_item),
684 key, btrfs_header_nritems(eb),
687 return generic_bin_search(eb,
688 offsetof(struct btrfs_node, ptrs),
689 sizeof(struct btrfs_key_ptr),
690 key, btrfs_header_nritems(eb),
696 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
697 struct extent_buffer *parent, int slot)
701 if (slot >= btrfs_header_nritems(parent))
703 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
704 btrfs_level_size(root, btrfs_header_level(parent) - 1));
707 static int balance_level(struct btrfs_trans_handle *trans,
708 struct btrfs_root *root,
709 struct btrfs_path *path, int level)
711 struct extent_buffer *right = NULL;
712 struct extent_buffer *mid;
713 struct extent_buffer *left = NULL;
714 struct extent_buffer *parent = NULL;
718 int orig_slot = path->slots[level];
719 int err_on_enospc = 0;
725 mid = path->nodes[level];
726 WARN_ON(btrfs_header_generation(mid) != trans->transid);
728 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
730 if (level < BTRFS_MAX_LEVEL - 1)
731 parent = path->nodes[level + 1];
732 pslot = path->slots[level + 1];
735 * deal with the case where there is only one pointer in the root
736 * by promoting the node below to a root
739 struct extent_buffer *child;
741 if (btrfs_header_nritems(mid) != 1)
744 /* promote the child to a root */
745 child = read_node_slot(root, mid, 0);
747 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
751 add_root_to_dirty_list(root);
752 path->nodes[level] = NULL;
753 clean_tree_block(trans, root, mid);
754 /* once for the path */
755 free_extent_buffer(mid);
756 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
757 root->root_key.objectid,
758 btrfs_header_generation(mid), 0, 0, 1);
759 /* once for the root ptr */
760 free_extent_buffer(mid);
763 if (btrfs_header_nritems(mid) >
764 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
767 if (btrfs_header_nritems(mid) < 2)
770 left = read_node_slot(root, parent, pslot - 1);
772 wret = btrfs_cow_block(trans, root, left,
773 parent, pslot - 1, &left);
779 right = read_node_slot(root, parent, pslot + 1);
781 wret = btrfs_cow_block(trans, root, right,
782 parent, pslot + 1, &right);
789 /* first, try to make some room in the middle buffer */
791 orig_slot += btrfs_header_nritems(left);
792 wret = push_node_left(trans, root, left, mid, 0);
795 if (btrfs_header_nritems(mid) < 2)
800 * then try to empty the right most buffer into the middle
803 wret = push_node_left(trans, root, mid, right, 1);
804 if (wret < 0 && wret != -ENOSPC)
806 if (btrfs_header_nritems(right) == 0) {
807 u64 bytenr = right->start;
808 u64 generation = btrfs_header_generation(parent);
809 u32 blocksize = right->len;
811 clean_tree_block(trans, root, right);
812 free_extent_buffer(right);
814 wret = del_ptr(trans, root, path, level + 1, pslot +
818 wret = btrfs_free_extent(trans, root, bytenr,
820 btrfs_header_owner(parent),
821 generation, 0, 0, 1);
825 struct btrfs_disk_key right_key;
826 btrfs_node_key(right, &right_key, 0);
827 btrfs_set_node_key(parent, &right_key, pslot + 1);
828 btrfs_mark_buffer_dirty(parent);
831 if (btrfs_header_nritems(mid) == 1) {
833 * we're not allowed to leave a node with one item in the
834 * tree during a delete. A deletion from lower in the tree
835 * could try to delete the only pointer in this node.
836 * So, pull some keys from the left.
837 * There has to be a left pointer at this point because
838 * otherwise we would have pulled some pointers from the
842 wret = balance_node_right(trans, root, mid, left);
849 if (btrfs_header_nritems(mid) == 0) {
850 /* we've managed to empty the middle node, drop it */
851 u64 root_gen = btrfs_header_generation(parent);
852 u64 bytenr = mid->start;
853 u32 blocksize = mid->len;
854 clean_tree_block(trans, root, mid);
855 free_extent_buffer(mid);
857 wret = del_ptr(trans, root, path, level + 1, pslot);
860 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
861 btrfs_header_owner(parent),
866 /* update the parent key to reflect our changes */
867 struct btrfs_disk_key mid_key;
868 btrfs_node_key(mid, &mid_key, 0);
869 btrfs_set_node_key(parent, &mid_key, pslot);
870 btrfs_mark_buffer_dirty(parent);
873 /* update the path */
875 if (btrfs_header_nritems(left) > orig_slot) {
876 extent_buffer_get(left);
877 path->nodes[level] = left;
878 path->slots[level + 1] -= 1;
879 path->slots[level] = orig_slot;
881 free_extent_buffer(mid);
883 orig_slot -= btrfs_header_nritems(left);
884 path->slots[level] = orig_slot;
887 /* double check we haven't messed things up */
888 check_block(root, path, level);
890 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
894 free_extent_buffer(right);
896 free_extent_buffer(left);
900 /* returns zero if the push worked, non-zero otherwise */
901 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
902 struct btrfs_root *root,
903 struct btrfs_path *path, int level)
905 struct extent_buffer *right = NULL;
906 struct extent_buffer *mid;
907 struct extent_buffer *left = NULL;
908 struct extent_buffer *parent = NULL;
912 int orig_slot = path->slots[level];
918 mid = path->nodes[level];
919 WARN_ON(btrfs_header_generation(mid) != trans->transid);
920 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
922 if (level < BTRFS_MAX_LEVEL - 1)
923 parent = path->nodes[level + 1];
924 pslot = path->slots[level + 1];
929 left = read_node_slot(root, parent, pslot - 1);
931 /* first, try to make some room in the middle buffer */
934 left_nr = btrfs_header_nritems(left);
935 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
938 ret = btrfs_cow_block(trans, root, left, parent,
943 wret = push_node_left(trans, root,
950 struct btrfs_disk_key disk_key;
951 orig_slot += left_nr;
952 btrfs_node_key(mid, &disk_key, 0);
953 btrfs_set_node_key(parent, &disk_key, pslot);
954 btrfs_mark_buffer_dirty(parent);
955 if (btrfs_header_nritems(left) > orig_slot) {
956 path->nodes[level] = left;
957 path->slots[level + 1] -= 1;
958 path->slots[level] = orig_slot;
959 free_extent_buffer(mid);
962 btrfs_header_nritems(left);
963 path->slots[level] = orig_slot;
964 free_extent_buffer(left);
968 free_extent_buffer(left);
970 right= read_node_slot(root, parent, pslot + 1);
973 * then try to empty the right most buffer into the middle
977 right_nr = btrfs_header_nritems(right);
978 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
981 ret = btrfs_cow_block(trans, root, right,
987 wret = balance_node_right(trans, root,
994 struct btrfs_disk_key disk_key;
996 btrfs_node_key(right, &disk_key, 0);
997 btrfs_set_node_key(parent, &disk_key, pslot + 1);
998 btrfs_mark_buffer_dirty(parent);
1000 if (btrfs_header_nritems(mid) <= orig_slot) {
1001 path->nodes[level] = right;
1002 path->slots[level + 1] += 1;
1003 path->slots[level] = orig_slot -
1004 btrfs_header_nritems(mid);
1005 free_extent_buffer(mid);
1007 free_extent_buffer(right);
1011 free_extent_buffer(right);
1017 * readahead one full node of leaves
1019 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1020 int level, int slot, u64 objectid)
1022 struct extent_buffer *node;
1023 struct btrfs_disk_key disk_key;
1029 int direction = path->reada;
1030 struct extent_buffer *eb;
1038 if (!path->nodes[level])
1041 node = path->nodes[level];
1042 search = btrfs_node_blockptr(node, slot);
1043 blocksize = btrfs_level_size(root, level - 1);
1044 eb = btrfs_find_tree_block(root, search, blocksize);
1046 free_extent_buffer(eb);
1050 highest_read = search;
1051 lowest_read = search;
1053 nritems = btrfs_header_nritems(node);
1056 if (direction < 0) {
1060 } else if (direction > 0) {
1065 if (path->reada < 0 && objectid) {
1066 btrfs_node_key(node, &disk_key, nr);
1067 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1070 search = btrfs_node_blockptr(node, nr);
1071 if ((search >= lowest_read && search <= highest_read) ||
1072 (search < lowest_read && lowest_read - search <= 32768) ||
1073 (search > highest_read && search - highest_read <= 32768)) {
1074 readahead_tree_block(root, search, blocksize);
1078 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1080 if(nread > (1024 * 1024) || nscan > 128)
1083 if (search < lowest_read)
1084 lowest_read = search;
1085 if (search > highest_read)
1086 highest_read = search;
1090 * look for key in the tree. path is filled in with nodes along the way
1091 * if key is found, we return zero and you can find the item in the leaf
1092 * level of the path (level 0)
1094 * If the key isn't found, the path points to the slot where it should
1095 * be inserted, and 1 is returned. If there are other errors during the
1096 * search a negative error number is returned.
1098 * if ins_len > 0, nodes and leaves will be split as we walk down the
1099 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1102 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1103 *root, struct btrfs_key *key, struct btrfs_path *p, int
1106 struct extent_buffer *b;
1112 int should_reada = p->reada;
1113 u8 lowest_level = 0;
1115 lowest_level = p->lowest_level;
1116 WARN_ON(lowest_level && ins_len);
1117 WARN_ON(p->nodes[0] != NULL);
1118 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1121 extent_buffer_get(b);
1123 level = btrfs_header_level(b);
1126 wret = btrfs_cow_block(trans, root, b,
1127 p->nodes[level + 1],
1128 p->slots[level + 1],
1131 free_extent_buffer(b);
1135 BUG_ON(!cow && ins_len);
1136 if (level != btrfs_header_level(b))
1138 level = btrfs_header_level(b);
1139 p->nodes[level] = b;
1140 ret = check_block(root, p, level);
1143 ret = bin_search(b, key, level, &slot);
1145 if (ret && slot > 0)
1147 p->slots[level] = slot;
1148 if (ins_len > 0 && btrfs_header_nritems(b) >=
1149 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1150 int sret = split_node(trans, root, p, level);
1154 b = p->nodes[level];
1155 slot = p->slots[level];
1156 } else if (ins_len < 0) {
1157 int sret = balance_level(trans, root, p,
1161 b = p->nodes[level];
1163 btrfs_release_path(NULL, p);
1166 slot = p->slots[level];
1167 BUG_ON(btrfs_header_nritems(b) == 1);
1169 /* this is only true while dropping a snapshot */
1170 if (level == lowest_level)
1172 bytenr = btrfs_node_blockptr(b, slot);
1173 ptr_gen = btrfs_node_ptr_generation(b, slot);
1175 reada_for_search(root, p, level, slot,
1177 b = read_tree_block(root, bytenr,
1178 btrfs_level_size(root, level - 1));
1179 if (ptr_gen != btrfs_header_generation(b)) {
1180 printk("block %llu bad gen wanted %llu "
1182 (unsigned long long)b->start,
1183 (unsigned long long)ptr_gen,
1184 (unsigned long long)btrfs_header_generation(b));
1187 p->slots[level] = slot;
1188 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1189 sizeof(struct btrfs_item) + ins_len) {
1190 int sret = split_leaf(trans, root, key,
1191 p, ins_len, ret == 0);
1203 * adjust the pointers going up the tree, starting at level
1204 * making sure the right key of each node is points to 'key'.
1205 * This is used after shifting pointers to the left, so it stops
1206 * fixing up pointers when a given leaf/node is not in slot 0 of the
1209 * If this fails to write a tree block, it returns -1, but continues
1210 * fixing up the blocks in ram so the tree is consistent.
1212 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1213 struct btrfs_root *root, struct btrfs_path *path,
1214 struct btrfs_disk_key *key, int level)
1218 struct extent_buffer *t;
1220 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1221 int tslot = path->slots[i];
1222 if (!path->nodes[i])
1225 btrfs_set_node_key(t, key, tslot);
1226 btrfs_mark_buffer_dirty(path->nodes[i]);
1234 * try to push data from one node into the next node left in the
1237 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1238 * error, and > 0 if there was no room in the left hand block.
1240 static int push_node_left(struct btrfs_trans_handle *trans,
1241 struct btrfs_root *root, struct extent_buffer *dst,
1242 struct extent_buffer *src, int empty)
1249 src_nritems = btrfs_header_nritems(src);
1250 dst_nritems = btrfs_header_nritems(dst);
1251 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1252 WARN_ON(btrfs_header_generation(src) != trans->transid);
1253 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1255 if (!empty && src_nritems <= 2)
1258 if (push_items <= 0) {
1263 push_items = min(src_nritems, push_items);
1265 push_items = min(src_nritems - 2, push_items);
1267 copy_extent_buffer(dst, src,
1268 btrfs_node_key_ptr_offset(dst_nritems),
1269 btrfs_node_key_ptr_offset(0),
1270 push_items * sizeof(struct btrfs_key_ptr));
1272 if (push_items < src_nritems) {
1273 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1274 btrfs_node_key_ptr_offset(push_items),
1275 (src_nritems - push_items) *
1276 sizeof(struct btrfs_key_ptr));
1278 btrfs_set_header_nritems(src, src_nritems - push_items);
1279 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1280 btrfs_mark_buffer_dirty(src);
1281 btrfs_mark_buffer_dirty(dst);
1286 * try to push data from one node into the next node right in the
1289 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1290 * error, and > 0 if there was no room in the right hand block.
1292 * this will only push up to 1/2 the contents of the left node over
1294 static int balance_node_right(struct btrfs_trans_handle *trans,
1295 struct btrfs_root *root,
1296 struct extent_buffer *dst,
1297 struct extent_buffer *src)
1305 WARN_ON(btrfs_header_generation(src) != trans->transid);
1306 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1308 src_nritems = btrfs_header_nritems(src);
1309 dst_nritems = btrfs_header_nritems(dst);
1310 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1311 if (push_items <= 0)
1314 max_push = src_nritems / 2 + 1;
1315 /* don't try to empty the node */
1316 if (max_push >= src_nritems)
1319 if (max_push < push_items)
1320 push_items = max_push;
1322 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1323 btrfs_node_key_ptr_offset(0),
1325 sizeof(struct btrfs_key_ptr));
1327 copy_extent_buffer(dst, src,
1328 btrfs_node_key_ptr_offset(0),
1329 btrfs_node_key_ptr_offset(src_nritems - push_items),
1330 push_items * sizeof(struct btrfs_key_ptr));
1332 btrfs_set_header_nritems(src, src_nritems - push_items);
1333 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1335 btrfs_mark_buffer_dirty(src);
1336 btrfs_mark_buffer_dirty(dst);
1341 * helper function to insert a new root level in the tree.
1342 * A new node is allocated, and a single item is inserted to
1343 * point to the existing root
1345 * returns zero on success or < 0 on failure.
1347 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1348 struct btrfs_root *root,
1349 struct btrfs_path *path, int level)
1353 struct extent_buffer *lower;
1354 struct extent_buffer *c;
1355 struct btrfs_disk_key lower_key;
1357 BUG_ON(path->nodes[level]);
1358 BUG_ON(path->nodes[level-1] != root->node);
1361 root_gen = trans->transid;
1365 lower = path->nodes[level-1];
1367 btrfs_item_key(lower, &lower_key, 0);
1369 btrfs_node_key(lower, &lower_key, 0);
1371 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1372 root->root_key.objectid,
1373 root_gen, lower_key.objectid, level,
1374 root->node->start, 0);
1377 memset_extent_buffer(c, 0, 0, root->nodesize);
1378 btrfs_set_header_nritems(c, 1);
1379 btrfs_set_header_level(c, level);
1380 btrfs_set_header_bytenr(c, c->start);
1381 btrfs_set_header_generation(c, trans->transid);
1382 btrfs_set_header_owner(c, root->root_key.objectid);
1384 write_extent_buffer(c, root->fs_info->fsid,
1385 (unsigned long)btrfs_header_fsid(c),
1388 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1389 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1392 btrfs_set_node_key(c, &lower_key, 0);
1393 btrfs_set_node_blockptr(c, 0, lower->start);
1394 lower_gen = btrfs_header_generation(lower);
1395 WARN_ON(lower_gen == 0);
1397 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1399 btrfs_mark_buffer_dirty(c);
1401 /* the super has an extra ref to root->node */
1402 free_extent_buffer(root->node);
1404 add_root_to_dirty_list(root);
1405 extent_buffer_get(c);
1406 path->nodes[level] = c;
1407 path->slots[level] = 0;
1409 if (root->ref_cows && lower_gen != trans->transid) {
1410 struct btrfs_path *back_path = btrfs_alloc_path();
1412 ret = btrfs_insert_extent_backref(trans,
1413 root->fs_info->extent_root,
1415 root->root_key.objectid,
1416 trans->transid, 0, 0);
1418 btrfs_free_path(back_path);
1424 * worker function to insert a single pointer in a node.
1425 * the node should have enough room for the pointer already
1427 * slot and level indicate where you want the key to go, and
1428 * blocknr is the block the key points to.
1430 * returns zero on success and < 0 on any error
1432 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1433 *root, struct btrfs_path *path, struct btrfs_disk_key
1434 *key, u64 bytenr, int slot, int level)
1436 struct extent_buffer *lower;
1439 BUG_ON(!path->nodes[level]);
1440 lower = path->nodes[level];
1441 nritems = btrfs_header_nritems(lower);
1444 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1446 if (slot != nritems) {
1447 memmove_extent_buffer(lower,
1448 btrfs_node_key_ptr_offset(slot + 1),
1449 btrfs_node_key_ptr_offset(slot),
1450 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1452 btrfs_set_node_key(lower, key, slot);
1453 btrfs_set_node_blockptr(lower, slot, bytenr);
1454 WARN_ON(trans->transid == 0);
1455 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1456 btrfs_set_header_nritems(lower, nritems + 1);
1457 btrfs_mark_buffer_dirty(lower);
1462 * split the node at the specified level in path in two.
1463 * The path is corrected to point to the appropriate node after the split
1465 * Before splitting this tries to make some room in the node by pushing
1466 * left and right, if either one works, it returns right away.
1468 * returns 0 on success and < 0 on failure
1470 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1471 *root, struct btrfs_path *path, int level)
1474 struct extent_buffer *c;
1475 struct extent_buffer *split;
1476 struct btrfs_disk_key disk_key;
1482 c = path->nodes[level];
1483 WARN_ON(btrfs_header_generation(c) != trans->transid);
1484 if (c == root->node) {
1485 /* trying to split the root, lets make a new one */
1486 ret = insert_new_root(trans, root, path, level + 1);
1490 ret = push_nodes_for_insert(trans, root, path, level);
1491 c = path->nodes[level];
1492 if (!ret && btrfs_header_nritems(c) <
1493 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1499 c_nritems = btrfs_header_nritems(c);
1501 root_gen = trans->transid;
1505 btrfs_node_key(c, &disk_key, 0);
1506 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1507 root->root_key.objectid,
1509 btrfs_disk_key_objectid(&disk_key),
1510 level, c->start, 0);
1512 return PTR_ERR(split);
1514 btrfs_set_header_flags(split, btrfs_header_flags(c));
1515 btrfs_set_header_level(split, btrfs_header_level(c));
1516 btrfs_set_header_bytenr(split, split->start);
1517 btrfs_set_header_generation(split, trans->transid);
1518 btrfs_set_header_owner(split, root->root_key.objectid);
1519 btrfs_set_header_flags(split, 0);
1520 write_extent_buffer(split, root->fs_info->fsid,
1521 (unsigned long)btrfs_header_fsid(split),
1523 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1524 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1527 mid = (c_nritems + 1) / 2;
1529 copy_extent_buffer(split, c,
1530 btrfs_node_key_ptr_offset(0),
1531 btrfs_node_key_ptr_offset(mid),
1532 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1533 btrfs_set_header_nritems(split, c_nritems - mid);
1534 btrfs_set_header_nritems(c, mid);
1537 btrfs_mark_buffer_dirty(c);
1538 btrfs_mark_buffer_dirty(split);
1540 btrfs_node_key(split, &disk_key, 0);
1541 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1542 path->slots[level + 1] + 1,
1547 if (path->slots[level] >= mid) {
1548 path->slots[level] -= mid;
1549 free_extent_buffer(c);
1550 path->nodes[level] = split;
1551 path->slots[level + 1] += 1;
1553 free_extent_buffer(split);
1559 * how many bytes are required to store the items in a leaf. start
1560 * and nr indicate which items in the leaf to check. This totals up the
1561 * space used both by the item structs and the item data
1563 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1566 int nritems = btrfs_header_nritems(l);
1567 int end = min(nritems, start + nr) - 1;
1571 data_len = btrfs_item_end_nr(l, start);
1572 data_len = data_len - btrfs_item_offset_nr(l, end);
1573 data_len += sizeof(struct btrfs_item) * nr;
1574 WARN_ON(data_len < 0);
1579 * The space between the end of the leaf items and
1580 * the start of the leaf data. IOW, how much room
1581 * the leaf has left for both items and data
1583 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1585 int nritems = btrfs_header_nritems(leaf);
1587 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1589 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1590 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1591 leaf_space_used(leaf, 0, nritems), nritems);
1597 * push some data in the path leaf to the right, trying to free up at
1598 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1600 * returns 1 if the push failed because the other node didn't have enough
1601 * room, 0 if everything worked out and < 0 if there were major errors.
1603 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1604 *root, struct btrfs_path *path, int data_size,
1607 struct extent_buffer *left = path->nodes[0];
1608 struct extent_buffer *right;
1609 struct extent_buffer *upper;
1610 struct btrfs_disk_key disk_key;
1616 struct btrfs_item *item;
1624 slot = path->slots[1];
1625 if (!path->nodes[1]) {
1628 upper = path->nodes[1];
1629 if (slot >= btrfs_header_nritems(upper) - 1)
1632 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1634 free_space = btrfs_leaf_free_space(root, right);
1635 if (free_space < data_size + sizeof(struct btrfs_item)) {
1636 free_extent_buffer(right);
1640 /* cow and double check */
1641 ret = btrfs_cow_block(trans, root, right, upper,
1644 free_extent_buffer(right);
1647 free_space = btrfs_leaf_free_space(root, right);
1648 if (free_space < data_size + sizeof(struct btrfs_item)) {
1649 free_extent_buffer(right);
1653 left_nritems = btrfs_header_nritems(left);
1654 if (left_nritems == 0) {
1655 free_extent_buffer(right);
1664 i = left_nritems - 1;
1666 item = btrfs_item_nr(left, i);
1668 if (path->slots[0] == i)
1669 push_space += data_size + sizeof(*item);
1671 if (!left->map_token) {
1672 map_extent_buffer(left, (unsigned long)item,
1673 sizeof(struct btrfs_item),
1674 &left->map_token, &left->kaddr,
1675 &left->map_start, &left->map_len,
1679 this_item_size = btrfs_item_size(left, item);
1680 if (this_item_size + sizeof(*item) + push_space > free_space)
1683 push_space += this_item_size + sizeof(*item);
1688 if (left->map_token) {
1689 unmap_extent_buffer(left, left->map_token, KM_USER1);
1690 left->map_token = NULL;
1693 if (push_items == 0) {
1694 free_extent_buffer(right);
1698 if (!empty && push_items == left_nritems)
1701 /* push left to right */
1702 right_nritems = btrfs_header_nritems(right);
1704 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1705 push_space -= leaf_data_end(root, left);
1707 /* make room in the right data area */
1708 data_end = leaf_data_end(root, right);
1709 memmove_extent_buffer(right,
1710 btrfs_leaf_data(right) + data_end - push_space,
1711 btrfs_leaf_data(right) + data_end,
1712 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1714 /* copy from the left data area */
1715 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1716 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1717 btrfs_leaf_data(left) + leaf_data_end(root, left),
1720 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1721 btrfs_item_nr_offset(0),
1722 right_nritems * sizeof(struct btrfs_item));
1724 /* copy the items from left to right */
1725 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1726 btrfs_item_nr_offset(left_nritems - push_items),
1727 push_items * sizeof(struct btrfs_item));
1729 /* update the item pointers */
1730 right_nritems += push_items;
1731 btrfs_set_header_nritems(right, right_nritems);
1732 push_space = BTRFS_LEAF_DATA_SIZE(root);
1733 for (i = 0; i < right_nritems; i++) {
1734 item = btrfs_item_nr(right, i);
1735 if (!right->map_token) {
1736 map_extent_buffer(right, (unsigned long)item,
1737 sizeof(struct btrfs_item),
1738 &right->map_token, &right->kaddr,
1739 &right->map_start, &right->map_len,
1742 push_space -= btrfs_item_size(right, item);
1743 btrfs_set_item_offset(right, item, push_space);
1746 if (right->map_token) {
1747 unmap_extent_buffer(right, right->map_token, KM_USER1);
1748 right->map_token = NULL;
1750 left_nritems -= push_items;
1751 btrfs_set_header_nritems(left, left_nritems);
1754 btrfs_mark_buffer_dirty(left);
1755 btrfs_mark_buffer_dirty(right);
1757 btrfs_item_key(right, &disk_key, 0);
1758 btrfs_set_node_key(upper, &disk_key, slot + 1);
1759 btrfs_mark_buffer_dirty(upper);
1761 /* then fixup the leaf pointer in the path */
1762 if (path->slots[0] >= left_nritems) {
1763 path->slots[0] -= left_nritems;
1764 free_extent_buffer(path->nodes[0]);
1765 path->nodes[0] = right;
1766 path->slots[1] += 1;
1768 free_extent_buffer(right);
1773 * push some data in the path leaf to the left, trying to free up at
1774 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1776 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1777 *root, struct btrfs_path *path, int data_size,
1780 struct btrfs_disk_key disk_key;
1781 struct extent_buffer *right = path->nodes[0];
1782 struct extent_buffer *left;
1788 struct btrfs_item *item;
1789 u32 old_left_nritems;
1795 u32 old_left_item_size;
1797 slot = path->slots[1];
1800 if (!path->nodes[1])
1803 right_nritems = btrfs_header_nritems(right);
1804 if (right_nritems == 0) {
1808 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1809 slot - 1), root->leafsize);
1810 free_space = btrfs_leaf_free_space(root, left);
1811 if (free_space < data_size + sizeof(struct btrfs_item)) {
1812 free_extent_buffer(left);
1816 /* cow and double check */
1817 ret = btrfs_cow_block(trans, root, left,
1818 path->nodes[1], slot - 1, &left);
1820 /* we hit -ENOSPC, but it isn't fatal here */
1821 free_extent_buffer(left);
1825 free_space = btrfs_leaf_free_space(root, left);
1826 if (free_space < data_size + sizeof(struct btrfs_item)) {
1827 free_extent_buffer(left);
1834 nr = right_nritems - 1;
1836 for (i = 0; i < nr; i++) {
1837 item = btrfs_item_nr(right, i);
1838 if (!right->map_token) {
1839 map_extent_buffer(right, (unsigned long)item,
1840 sizeof(struct btrfs_item),
1841 &right->map_token, &right->kaddr,
1842 &right->map_start, &right->map_len,
1846 if (path->slots[0] == i)
1847 push_space += data_size + sizeof(*item);
1849 this_item_size = btrfs_item_size(right, item);
1850 if (this_item_size + sizeof(*item) + push_space > free_space)
1854 push_space += this_item_size + sizeof(*item);
1857 if (right->map_token) {
1858 unmap_extent_buffer(right, right->map_token, KM_USER1);
1859 right->map_token = NULL;
1862 if (push_items == 0) {
1863 free_extent_buffer(left);
1866 if (!empty && push_items == btrfs_header_nritems(right))
1869 /* push data from right to left */
1870 copy_extent_buffer(left, right,
1871 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1872 btrfs_item_nr_offset(0),
1873 push_items * sizeof(struct btrfs_item));
1875 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1876 btrfs_item_offset_nr(right, push_items -1);
1878 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1879 leaf_data_end(root, left) - push_space,
1880 btrfs_leaf_data(right) +
1881 btrfs_item_offset_nr(right, push_items - 1),
1883 old_left_nritems = btrfs_header_nritems(left);
1884 BUG_ON(old_left_nritems < 0);
1886 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1887 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1890 item = btrfs_item_nr(left, i);
1891 if (!left->map_token) {
1892 map_extent_buffer(left, (unsigned long)item,
1893 sizeof(struct btrfs_item),
1894 &left->map_token, &left->kaddr,
1895 &left->map_start, &left->map_len,
1899 ioff = btrfs_item_offset(left, item);
1900 btrfs_set_item_offset(left, item,
1901 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1903 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1904 if (left->map_token) {
1905 unmap_extent_buffer(left, left->map_token, KM_USER1);
1906 left->map_token = NULL;
1909 /* fixup right node */
1910 if (push_items > right_nritems) {
1911 printk("push items %d nr %u\n", push_items, right_nritems);
1915 if (push_items < right_nritems) {
1916 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1917 leaf_data_end(root, right);
1918 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1919 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1920 btrfs_leaf_data(right) +
1921 leaf_data_end(root, right), push_space);
1923 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1924 btrfs_item_nr_offset(push_items),
1925 (btrfs_header_nritems(right) - push_items) *
1926 sizeof(struct btrfs_item));
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);
1934 if (!right->map_token) {
1935 map_extent_buffer(right, (unsigned long)item,
1936 sizeof(struct btrfs_item),
1937 &right->map_token, &right->kaddr,
1938 &right->map_start, &right->map_len,
1942 push_space = push_space - btrfs_item_size(right, item);
1943 btrfs_set_item_offset(right, item, push_space);
1945 if (right->map_token) {
1946 unmap_extent_buffer(right, right->map_token, KM_USER1);
1947 right->map_token = NULL;
1950 btrfs_mark_buffer_dirty(left);
1952 btrfs_mark_buffer_dirty(right);
1954 btrfs_item_key(right, &disk_key, 0);
1955 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1959 /* then fixup the leaf pointer in the path */
1960 if (path->slots[0] < push_items) {
1961 path->slots[0] += old_left_nritems;
1962 free_extent_buffer(path->nodes[0]);
1963 path->nodes[0] = left;
1964 path->slots[1] -= 1;
1966 free_extent_buffer(left);
1967 path->slots[0] -= push_items;
1969 BUG_ON(path->slots[0] < 0);
1974 * split the path's leaf in two, making sure there is at least data_size
1975 * available for the resulting leaf level of the path.
1977 * returns 0 if all went well and < 0 on failure.
1979 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1980 *root, struct btrfs_key *ins_key,
1981 struct btrfs_path *path, int data_size, int extend)
1984 struct extent_buffer *l;
1988 struct extent_buffer *right;
1989 int space_needed = data_size + sizeof(struct btrfs_item);
1996 int num_doubles = 0;
1997 struct btrfs_disk_key disk_key;
2000 space_needed = data_size;
2003 root_gen = trans->transid;
2007 /* first try to make some room by pushing left and right */
2008 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
2009 wret = push_leaf_right(trans, root, path, data_size, 0);
2014 wret = push_leaf_left(trans, root, path, data_size, 0);
2020 /* did the pushes work? */
2021 if (btrfs_leaf_free_space(root, l) >= space_needed)
2025 if (!path->nodes[1]) {
2026 ret = insert_new_root(trans, root, path, 1);
2033 slot = path->slots[0];
2034 nritems = btrfs_header_nritems(l);
2035 mid = (nritems + 1)/ 2;
2037 btrfs_item_key(l, &disk_key, 0);
2039 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
2040 root->root_key.objectid,
2041 root_gen, disk_key.objectid, 0,
2043 if (IS_ERR(right)) {
2045 return PTR_ERR(right);
2048 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2049 btrfs_set_header_bytenr(right, right->start);
2050 btrfs_set_header_generation(right, trans->transid);
2051 btrfs_set_header_owner(right, root->root_key.objectid);
2052 btrfs_set_header_level(right, 0);
2053 write_extent_buffer(right, root->fs_info->fsid,
2054 (unsigned long)btrfs_header_fsid(right),
2057 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2058 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2062 leaf_space_used(l, mid, nritems - mid) + space_needed >
2063 BTRFS_LEAF_DATA_SIZE(root)) {
2064 if (slot >= nritems) {
2065 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2066 btrfs_set_header_nritems(right, 0);
2067 wret = insert_ptr(trans, root, path,
2068 &disk_key, right->start,
2069 path->slots[1] + 1, 1);
2072 free_extent_buffer(path->nodes[0]);
2073 path->nodes[0] = right;
2075 path->slots[1] += 1;
2076 btrfs_mark_buffer_dirty(right);
2080 if (mid != nritems &&
2081 leaf_space_used(l, mid, nritems - mid) +
2082 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2087 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2088 BTRFS_LEAF_DATA_SIZE(root)) {
2089 if (!extend && slot == 0) {
2090 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2091 btrfs_set_header_nritems(right, 0);
2092 wret = insert_ptr(trans, root, path,
2098 free_extent_buffer(path->nodes[0]);
2099 path->nodes[0] = right;
2101 if (path->slots[1] == 0) {
2102 wret = fixup_low_keys(trans, root,
2103 path, &disk_key, 1);
2107 btrfs_mark_buffer_dirty(right);
2109 } else if (extend && slot == 0) {
2113 if (mid != nritems &&
2114 leaf_space_used(l, mid, nritems - mid) +
2115 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2121 nritems = nritems - mid;
2122 btrfs_set_header_nritems(right, nritems);
2123 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2125 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2126 btrfs_item_nr_offset(mid),
2127 nritems * sizeof(struct btrfs_item));
2129 copy_extent_buffer(right, l,
2130 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2131 data_copy_size, btrfs_leaf_data(l) +
2132 leaf_data_end(root, l), data_copy_size);
2134 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2135 btrfs_item_end_nr(l, mid);
2137 for (i = 0; i < nritems; i++) {
2138 struct btrfs_item *item = btrfs_item_nr(right, i);
2141 if (!right->map_token) {
2142 map_extent_buffer(right, (unsigned long)item,
2143 sizeof(struct btrfs_item),
2144 &right->map_token, &right->kaddr,
2145 &right->map_start, &right->map_len,
2149 ioff = btrfs_item_offset(right, item);
2150 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2153 if (right->map_token) {
2154 unmap_extent_buffer(right, right->map_token, KM_USER1);
2155 right->map_token = NULL;
2158 btrfs_set_header_nritems(l, mid);
2160 btrfs_item_key(right, &disk_key, 0);
2161 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2162 path->slots[1] + 1, 1);
2166 btrfs_mark_buffer_dirty(right);
2167 btrfs_mark_buffer_dirty(l);
2168 BUG_ON(path->slots[0] != slot);
2171 free_extent_buffer(path->nodes[0]);
2172 path->nodes[0] = right;
2173 path->slots[0] -= mid;
2174 path->slots[1] += 1;
2176 free_extent_buffer(right);
2178 BUG_ON(path->slots[0] < 0);
2181 BUG_ON(num_doubles != 0);
2188 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2189 struct btrfs_root *root,
2190 struct btrfs_path *path,
2191 u32 new_size, int from_end)
2196 struct extent_buffer *leaf;
2197 struct btrfs_item *item;
2199 unsigned int data_end;
2200 unsigned int old_data_start;
2201 unsigned int old_size;
2202 unsigned int size_diff;
2205 slot_orig = path->slots[0];
2206 leaf = path->nodes[0];
2207 slot = path->slots[0];
2209 old_size = btrfs_item_size_nr(leaf, slot);
2210 if (old_size == new_size)
2213 nritems = btrfs_header_nritems(leaf);
2214 data_end = leaf_data_end(root, leaf);
2216 old_data_start = btrfs_item_offset_nr(leaf, slot);
2218 size_diff = old_size - new_size;
2221 BUG_ON(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);
2231 if (!leaf->map_token) {
2232 map_extent_buffer(leaf, (unsigned long)item,
2233 sizeof(struct btrfs_item),
2234 &leaf->map_token, &leaf->kaddr,
2235 &leaf->map_start, &leaf->map_len,
2239 ioff = btrfs_item_offset(leaf, item);
2240 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2243 if (leaf->map_token) {
2244 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2245 leaf->map_token = NULL;
2248 /* shift the data */
2250 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2251 data_end + size_diff, btrfs_leaf_data(leaf) +
2252 data_end, old_data_start + new_size - data_end);
2254 struct btrfs_disk_key disk_key;
2257 btrfs_item_key(leaf, &disk_key, slot);
2259 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2261 struct btrfs_file_extent_item *fi;
2263 fi = btrfs_item_ptr(leaf, slot,
2264 struct btrfs_file_extent_item);
2265 fi = (struct btrfs_file_extent_item *)(
2266 (unsigned long)fi - size_diff);
2268 if (btrfs_file_extent_type(leaf, fi) ==
2269 BTRFS_FILE_EXTENT_INLINE) {
2270 ptr = btrfs_item_ptr_offset(leaf, slot);
2271 memmove_extent_buffer(leaf, ptr,
2273 offsetof(struct btrfs_file_extent_item,
2278 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2279 data_end + size_diff, btrfs_leaf_data(leaf) +
2280 data_end, old_data_start - data_end);
2282 offset = btrfs_disk_key_offset(&disk_key);
2283 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2284 btrfs_set_item_key(leaf, &disk_key, slot);
2286 fixup_low_keys(trans, root, path, &disk_key, 1);
2289 item = btrfs_item_nr(leaf, slot);
2290 btrfs_set_item_size(leaf, item, new_size);
2291 btrfs_mark_buffer_dirty(leaf);
2294 if (btrfs_leaf_free_space(root, leaf) < 0) {
2295 btrfs_print_leaf(root, leaf);
2301 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2302 struct btrfs_root *root, struct btrfs_path *path,
2308 struct extent_buffer *leaf;
2309 struct btrfs_item *item;
2311 unsigned int data_end;
2312 unsigned int old_data;
2313 unsigned int old_size;
2316 slot_orig = path->slots[0];
2317 leaf = path->nodes[0];
2319 nritems = btrfs_header_nritems(leaf);
2320 data_end = leaf_data_end(root, leaf);
2322 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2323 btrfs_print_leaf(root, leaf);
2326 slot = path->slots[0];
2327 old_data = btrfs_item_end_nr(leaf, slot);
2330 if (slot >= nritems) {
2331 btrfs_print_leaf(root, leaf);
2332 printk("slot %d too large, nritems %d\n", slot, nritems);
2337 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2339 /* first correct the data pointers */
2340 for (i = slot; i < nritems; i++) {
2342 item = btrfs_item_nr(leaf, i);
2344 if (!leaf->map_token) {
2345 map_extent_buffer(leaf, (unsigned long)item,
2346 sizeof(struct btrfs_item),
2347 &leaf->map_token, &leaf->kaddr,
2348 &leaf->map_start, &leaf->map_len,
2351 ioff = btrfs_item_offset(leaf, item);
2352 btrfs_set_item_offset(leaf, item, ioff - data_size);
2355 if (leaf->map_token) {
2356 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2357 leaf->map_token = NULL;
2360 /* shift the data */
2361 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2362 data_end - data_size, btrfs_leaf_data(leaf) +
2363 data_end, old_data - data_end);
2365 data_end = old_data;
2366 old_size = btrfs_item_size_nr(leaf, slot);
2367 item = btrfs_item_nr(leaf, slot);
2368 btrfs_set_item_size(leaf, item, old_size + data_size);
2369 btrfs_mark_buffer_dirty(leaf);
2372 if (btrfs_leaf_free_space(root, leaf) < 0) {
2373 btrfs_print_leaf(root, leaf);
2380 * Given a key and some data, insert an item into the tree.
2381 * This does all the path init required, making room in the tree if needed.
2383 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2384 struct btrfs_root *root,
2385 struct btrfs_path *path,
2386 struct btrfs_key *cpu_key, u32 *data_size,
2389 struct extent_buffer *leaf;
2390 struct btrfs_item *item;
2398 unsigned int data_end;
2399 struct btrfs_disk_key disk_key;
2401 for (i = 0; i < nr; i++) {
2402 total_data += data_size[i];
2405 /* create a root if there isn't one */
2409 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2410 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2417 slot_orig = path->slots[0];
2418 leaf = path->nodes[0];
2420 nritems = btrfs_header_nritems(leaf);
2421 data_end = leaf_data_end(root, leaf);
2423 if (btrfs_leaf_free_space(root, leaf) <
2424 sizeof(struct btrfs_item) + total_size) {
2425 btrfs_print_leaf(root, leaf);
2426 printk("not enough freespace need %u have %d\n",
2427 total_size, btrfs_leaf_free_space(root, leaf));
2431 slot = path->slots[0];
2434 if (slot != nritems) {
2436 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2438 if (old_data < data_end) {
2439 btrfs_print_leaf(root, leaf);
2440 printk("slot %d old_data %d data_end %d\n",
2441 slot, old_data, data_end);
2445 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2447 /* first correct the data pointers */
2448 WARN_ON(leaf->map_token);
2449 for (i = slot; i < nritems; i++) {
2452 item = btrfs_item_nr(leaf, i);
2453 if (!leaf->map_token) {
2454 map_extent_buffer(leaf, (unsigned long)item,
2455 sizeof(struct btrfs_item),
2456 &leaf->map_token, &leaf->kaddr,
2457 &leaf->map_start, &leaf->map_len,
2461 ioff = btrfs_item_offset(leaf, item);
2462 btrfs_set_item_offset(leaf, item, ioff - total_data);
2464 if (leaf->map_token) {
2465 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2466 leaf->map_token = NULL;
2469 /* shift the items */
2470 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2471 btrfs_item_nr_offset(slot),
2472 (nritems - slot) * sizeof(struct btrfs_item));
2474 /* shift the data */
2475 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2476 data_end - total_data, btrfs_leaf_data(leaf) +
2477 data_end, old_data - data_end);
2478 data_end = old_data;
2481 /* setup the item for the new data */
2482 for (i = 0; i < nr; i++) {
2483 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2484 btrfs_set_item_key(leaf, &disk_key, slot + i);
2485 item = btrfs_item_nr(leaf, slot + i);
2486 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2487 data_end -= data_size[i];
2488 btrfs_set_item_size(leaf, item, data_size[i]);
2490 btrfs_set_header_nritems(leaf, nritems + nr);
2491 btrfs_mark_buffer_dirty(leaf);
2495 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2496 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2499 if (btrfs_leaf_free_space(root, leaf) < 0) {
2500 btrfs_print_leaf(root, leaf);
2509 * Given a key and some data, insert an item into the tree.
2510 * This does all the path init required, making room in the tree if needed.
2512 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2513 *root, struct btrfs_key *cpu_key, void *data, u32
2517 struct btrfs_path *path;
2518 struct extent_buffer *leaf;
2521 path = btrfs_alloc_path();
2523 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2525 leaf = path->nodes[0];
2526 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2527 write_extent_buffer(leaf, data, ptr, data_size);
2528 btrfs_mark_buffer_dirty(leaf);
2530 btrfs_free_path(path);
2535 * delete the pointer from a given node.
2537 * If the delete empties a node, the node is removed from the tree,
2538 * continuing all the way the root if required. The root is converted into
2539 * a leaf if all the nodes are emptied.
2541 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2542 struct btrfs_path *path, int level, int slot)
2544 struct extent_buffer *parent = path->nodes[level];
2549 nritems = btrfs_header_nritems(parent);
2550 if (slot != nritems -1) {
2551 memmove_extent_buffer(parent,
2552 btrfs_node_key_ptr_offset(slot),
2553 btrfs_node_key_ptr_offset(slot + 1),
2554 sizeof(struct btrfs_key_ptr) *
2555 (nritems - slot - 1));
2558 btrfs_set_header_nritems(parent, nritems);
2559 if (nritems == 0 && parent == root->node) {
2560 BUG_ON(btrfs_header_level(root->node) != 1);
2561 /* just turn the root into a leaf and break */
2562 btrfs_set_header_level(root->node, 0);
2563 } else if (slot == 0) {
2564 struct btrfs_disk_key disk_key;
2566 btrfs_node_key(parent, &disk_key, 0);
2567 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2571 btrfs_mark_buffer_dirty(parent);
2576 * delete the item at the leaf level in path. If that empties
2577 * the leaf, remove it from the tree
2579 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2580 struct btrfs_path *path, int slot, int nr)
2582 struct extent_buffer *leaf;
2583 struct btrfs_item *item;
2591 leaf = path->nodes[0];
2592 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2594 for (i = 0; i < nr; i++)
2595 dsize += btrfs_item_size_nr(leaf, slot + i);
2597 nritems = btrfs_header_nritems(leaf);
2599 if (slot + nr != nritems) {
2601 int data_end = leaf_data_end(root, leaf);
2603 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2605 btrfs_leaf_data(leaf) + data_end,
2606 last_off - data_end);
2608 for (i = slot + nr; i < nritems; i++) {
2611 item = btrfs_item_nr(leaf, i);
2612 if (!leaf->map_token) {
2613 map_extent_buffer(leaf, (unsigned long)item,
2614 sizeof(struct btrfs_item),
2615 &leaf->map_token, &leaf->kaddr,
2616 &leaf->map_start, &leaf->map_len,
2619 ioff = btrfs_item_offset(leaf, item);
2620 btrfs_set_item_offset(leaf, item, ioff + dsize);
2623 if (leaf->map_token) {
2624 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2625 leaf->map_token = NULL;
2628 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2629 btrfs_item_nr_offset(slot + nr),
2630 sizeof(struct btrfs_item) *
2631 (nritems - slot - nr));
2633 btrfs_set_header_nritems(leaf, nritems - nr);
2636 /* delete the leaf if we've emptied it */
2638 if (leaf == root->node) {
2639 btrfs_set_header_level(leaf, 0);
2641 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2642 clean_tree_block(trans, root, leaf);
2643 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2646 wret = btrfs_free_extent(trans, root,
2647 leaf->start, leaf->len,
2648 btrfs_header_owner(path->nodes[1]),
2654 int used = leaf_space_used(leaf, 0, nritems);
2656 struct btrfs_disk_key disk_key;
2658 btrfs_item_key(leaf, &disk_key, 0);
2659 wret = fixup_low_keys(trans, root, path,
2665 /* delete the leaf if it is mostly empty */
2666 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2667 /* push_leaf_left fixes the path.
2668 * make sure the path still points to our leaf
2669 * for possible call to del_ptr below
2671 slot = path->slots[1];
2672 extent_buffer_get(leaf);
2674 wret = push_leaf_left(trans, root, path, 1, 1);
2675 if (wret < 0 && wret != -ENOSPC)
2678 if (path->nodes[0] == leaf &&
2679 btrfs_header_nritems(leaf)) {
2680 wret = push_leaf_right(trans, root, path, 1, 1);
2681 if (wret < 0 && wret != -ENOSPC)
2685 if (btrfs_header_nritems(leaf) == 0) {
2687 u64 bytenr = leaf->start;
2688 u32 blocksize = leaf->len;
2690 root_gen = btrfs_header_generation(
2693 clean_tree_block(trans, root, leaf);
2695 wret = del_ptr(trans, root, path, 1, slot);
2699 free_extent_buffer(leaf);
2700 wret = btrfs_free_extent(trans, root, bytenr,
2702 btrfs_header_owner(path->nodes[1]),
2707 btrfs_mark_buffer_dirty(leaf);
2708 free_extent_buffer(leaf);
2711 btrfs_mark_buffer_dirty(leaf);
2718 * walk up the tree as far as required to find the previous leaf.
2719 * returns 0 if it found something or 1 if there are no lesser leaves.
2720 * returns < 0 on io errors.
2722 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2727 struct extent_buffer *c;
2728 struct extent_buffer *next = NULL;
2730 while(level < BTRFS_MAX_LEVEL) {
2731 if (!path->nodes[level])
2734 slot = path->slots[level];
2735 c = path->nodes[level];
2738 if (level == BTRFS_MAX_LEVEL)
2744 bytenr = btrfs_node_blockptr(c, slot);
2746 free_extent_buffer(next);
2748 next = read_tree_block(root, bytenr,
2749 btrfs_level_size(root, level - 1));
2752 path->slots[level] = slot;
2755 c = path->nodes[level];
2756 free_extent_buffer(c);
2757 slot = btrfs_header_nritems(next);
2760 path->nodes[level] = next;
2761 path->slots[level] = slot;
2764 next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2765 btrfs_level_size(root, level - 1));
2771 * walk up the tree as far as required to find the next leaf.
2772 * returns 0 if it found something or 1 if there are no greater leaves.
2773 * returns < 0 on io errors.
2775 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2780 struct extent_buffer *c;
2781 struct extent_buffer *next = NULL;
2783 while(level < BTRFS_MAX_LEVEL) {
2784 if (!path->nodes[level])
2787 slot = path->slots[level] + 1;
2788 c = path->nodes[level];
2789 if (slot >= btrfs_header_nritems(c)) {
2791 if (level == BTRFS_MAX_LEVEL)
2796 bytenr = btrfs_node_blockptr(c, slot);
2798 free_extent_buffer(next);
2801 reada_for_search(root, path, level, slot, 0);
2803 next = read_tree_block(root, bytenr,
2804 btrfs_level_size(root, level -1));
2807 path->slots[level] = slot;
2810 c = path->nodes[level];
2811 free_extent_buffer(c);
2812 path->nodes[level] = next;
2813 path->slots[level] = 0;
2817 reada_for_search(root, path, level, 0, 0);
2818 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2819 btrfs_level_size(root, level - 1));
2824 int btrfs_previous_item(struct btrfs_root *root,
2825 struct btrfs_path *path, u64 min_objectid,
2828 struct btrfs_key found_key;
2829 struct extent_buffer *leaf;
2833 if (path->slots[0] == 0) {
2834 ret = btrfs_prev_leaf(root, path);
2840 leaf = path->nodes[0];
2841 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2842 if (found_key.type == type)