2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
26 *root, struct btrfs_path *path, int level);
27 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
28 *root, struct btrfs_key *ins_key,
29 struct btrfs_path *path, int data_size, int extend);
30 static int push_node_left(struct btrfs_trans_handle *trans,
31 struct btrfs_root *root, struct extent_buffer *dst,
32 struct extent_buffer *src);
33 static int balance_node_right(struct btrfs_trans_handle *trans,
34 struct btrfs_root *root,
35 struct extent_buffer *dst_buf,
36 struct extent_buffer *src_buf);
37 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
38 struct btrfs_path *path, int level, int slot);
40 inline void btrfs_init_path(struct btrfs_path *p)
42 memset(p, 0, sizeof(*p));
45 struct btrfs_path *btrfs_alloc_path(void)
47 struct btrfs_path *path;
48 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
50 btrfs_init_path(path);
56 void btrfs_free_path(struct btrfs_path *p)
58 btrfs_release_path(NULL, p);
59 kmem_cache_free(btrfs_path_cachep, p);
62 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
65 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
68 free_extent_buffer(p->nodes[i]);
70 memset(p, 0, sizeof(*p));
73 static 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 wait_on_tree_block_writeback(root, mid);
755 /* once for the path */
756 free_extent_buffer(mid);
757 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
758 root->root_key.objectid,
759 btrfs_header_generation(mid), 0, 0, 1);
760 /* once for the root ptr */
761 free_extent_buffer(mid);
764 if (btrfs_header_nritems(mid) >
765 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
768 if (btrfs_header_nritems(mid) < 2)
771 left = read_node_slot(root, parent, pslot - 1);
773 wret = btrfs_cow_block(trans, root, left,
774 parent, pslot - 1, &left);
780 right = read_node_slot(root, parent, pslot + 1);
782 wret = btrfs_cow_block(trans, root, right,
783 parent, pslot + 1, &right);
790 /* first, try to make some room in the middle buffer */
792 orig_slot += btrfs_header_nritems(left);
793 wret = push_node_left(trans, root, left, mid);
796 if (btrfs_header_nritems(mid) < 2)
801 * then try to empty the right most buffer into the middle
804 wret = push_node_left(trans, root, mid, right);
805 if (wret < 0 && wret != -ENOSPC)
807 if (btrfs_header_nritems(right) == 0) {
808 u64 bytenr = right->start;
809 u64 generation = btrfs_header_generation(parent);
810 u32 blocksize = right->len;
812 clean_tree_block(trans, root, right);
813 wait_on_tree_block_writeback(root, right);
814 free_extent_buffer(right);
816 wret = del_ptr(trans, root, path, level + 1, pslot +
820 wret = btrfs_free_extent(trans, root, bytenr,
822 btrfs_header_owner(parent),
823 generation, 0, 0, 1);
827 struct btrfs_disk_key right_key;
828 btrfs_node_key(right, &right_key, 0);
829 btrfs_set_node_key(parent, &right_key, pslot + 1);
830 btrfs_mark_buffer_dirty(parent);
833 if (btrfs_header_nritems(mid) == 1) {
835 * we're not allowed to leave a node with one item in the
836 * tree during a delete. A deletion from lower in the tree
837 * could try to delete the only pointer in this node.
838 * So, pull some keys from the left.
839 * There has to be a left pointer at this point because
840 * otherwise we would have pulled some pointers from the
844 wret = balance_node_right(trans, root, mid, left);
851 if (btrfs_header_nritems(mid) == 0) {
852 /* we've managed to empty the middle node, drop it */
853 u64 root_gen = btrfs_header_generation(parent);
854 u64 bytenr = mid->start;
855 u32 blocksize = mid->len;
856 clean_tree_block(trans, root, mid);
857 wait_on_tree_block_writeback(root, mid);
858 free_extent_buffer(mid);
860 wret = del_ptr(trans, root, path, level + 1, pslot);
863 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
864 btrfs_header_owner(parent),
869 /* update the parent key to reflect our changes */
870 struct btrfs_disk_key mid_key;
871 btrfs_node_key(mid, &mid_key, 0);
872 btrfs_set_node_key(parent, &mid_key, pslot);
873 btrfs_mark_buffer_dirty(parent);
876 /* update the path */
878 if (btrfs_header_nritems(left) > orig_slot) {
879 extent_buffer_get(left);
880 path->nodes[level] = left;
881 path->slots[level + 1] -= 1;
882 path->slots[level] = orig_slot;
884 free_extent_buffer(mid);
886 orig_slot -= btrfs_header_nritems(left);
887 path->slots[level] = orig_slot;
890 /* double check we haven't messed things up */
891 check_block(root, path, level);
893 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
897 free_extent_buffer(right);
899 free_extent_buffer(left);
903 /* returns zero if the push worked, non-zero otherwise */
904 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
905 struct btrfs_root *root,
906 struct btrfs_path *path, int level)
908 struct extent_buffer *right = NULL;
909 struct extent_buffer *mid;
910 struct extent_buffer *left = NULL;
911 struct extent_buffer *parent = NULL;
915 int orig_slot = path->slots[level];
921 mid = path->nodes[level];
922 WARN_ON(btrfs_header_generation(mid) != trans->transid);
923 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
925 if (level < BTRFS_MAX_LEVEL - 1)
926 parent = path->nodes[level + 1];
927 pslot = path->slots[level + 1];
932 left = read_node_slot(root, parent, pslot - 1);
934 /* first, try to make some room in the middle buffer */
937 left_nr = btrfs_header_nritems(left);
938 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
941 ret = btrfs_cow_block(trans, root, left, parent,
946 wret = push_node_left(trans, root,
953 struct btrfs_disk_key disk_key;
954 orig_slot += left_nr;
955 btrfs_node_key(mid, &disk_key, 0);
956 btrfs_set_node_key(parent, &disk_key, pslot);
957 btrfs_mark_buffer_dirty(parent);
958 if (btrfs_header_nritems(left) > orig_slot) {
959 path->nodes[level] = left;
960 path->slots[level + 1] -= 1;
961 path->slots[level] = orig_slot;
962 free_extent_buffer(mid);
965 btrfs_header_nritems(left);
966 path->slots[level] = orig_slot;
967 free_extent_buffer(left);
971 free_extent_buffer(left);
973 right= read_node_slot(root, parent, pslot + 1);
976 * then try to empty the right most buffer into the middle
980 right_nr = btrfs_header_nritems(right);
981 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
984 ret = btrfs_cow_block(trans, root, right,
990 wret = balance_node_right(trans, root,
997 struct btrfs_disk_key disk_key;
999 btrfs_node_key(right, &disk_key, 0);
1000 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1001 btrfs_mark_buffer_dirty(parent);
1003 if (btrfs_header_nritems(mid) <= orig_slot) {
1004 path->nodes[level] = right;
1005 path->slots[level + 1] += 1;
1006 path->slots[level] = orig_slot -
1007 btrfs_header_nritems(mid);
1008 free_extent_buffer(mid);
1010 free_extent_buffer(right);
1014 free_extent_buffer(right);
1020 * readahead one full node of leaves
1022 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1023 int level, int slot, u64 objectid)
1025 struct extent_buffer *node;
1026 struct btrfs_disk_key disk_key;
1032 int direction = path->reada;
1033 struct extent_buffer *eb;
1041 if (!path->nodes[level])
1044 node = path->nodes[level];
1045 search = btrfs_node_blockptr(node, slot);
1046 blocksize = btrfs_level_size(root, level - 1);
1047 eb = btrfs_find_tree_block(root, search, blocksize);
1049 free_extent_buffer(eb);
1053 highest_read = search;
1054 lowest_read = search;
1056 nritems = btrfs_header_nritems(node);
1059 if (direction < 0) {
1063 } else if (direction > 0) {
1068 if (path->reada < 0 && objectid) {
1069 btrfs_node_key(node, &disk_key, nr);
1070 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1073 search = btrfs_node_blockptr(node, nr);
1074 if ((search >= lowest_read && search <= highest_read) ||
1075 (search < lowest_read && lowest_read - search <= 32768) ||
1076 (search > highest_read && search - highest_read <= 32768)) {
1077 readahead_tree_block(root, search, blocksize);
1081 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1083 if(nread > (1024 * 1024) || nscan > 128)
1086 if (search < lowest_read)
1087 lowest_read = search;
1088 if (search > highest_read)
1089 highest_read = search;
1093 * look for key in the tree. path is filled in with nodes along the way
1094 * if key is found, we return zero and you can find the item in the leaf
1095 * level of the path (level 0)
1097 * If the key isn't found, the path points to the slot where it should
1098 * be inserted, and 1 is returned. If there are other errors during the
1099 * search a negative error number is returned.
1101 * if ins_len > 0, nodes and leaves will be split as we walk down the
1102 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1105 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1106 *root, struct btrfs_key *key, struct btrfs_path *p, int
1109 struct extent_buffer *b;
1115 int should_reada = p->reada;
1116 u8 lowest_level = 0;
1118 lowest_level = p->lowest_level;
1119 WARN_ON(lowest_level && ins_len);
1120 WARN_ON(p->nodes[0] != NULL);
1121 WARN_ON(!mutex_is_locked(&root->fs_info->fs_mutex));
1124 extent_buffer_get(b);
1126 level = btrfs_header_level(b);
1129 wret = btrfs_cow_block(trans, root, b,
1130 p->nodes[level + 1],
1131 p->slots[level + 1],
1134 free_extent_buffer(b);
1138 BUG_ON(!cow && ins_len);
1139 if (level != btrfs_header_level(b))
1141 level = btrfs_header_level(b);
1142 p->nodes[level] = b;
1143 ret = check_block(root, p, level);
1146 ret = bin_search(b, key, level, &slot);
1148 if (ret && slot > 0)
1150 p->slots[level] = slot;
1151 if (ins_len > 0 && btrfs_header_nritems(b) >=
1152 BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1153 int sret = split_node(trans, root, p, level);
1157 b = p->nodes[level];
1158 slot = p->slots[level];
1159 } else if (ins_len < 0) {
1160 int sret = balance_level(trans, root, p,
1164 b = p->nodes[level];
1166 btrfs_release_path(NULL, p);
1169 slot = p->slots[level];
1170 BUG_ON(btrfs_header_nritems(b) == 1);
1172 /* this is only true while dropping a snapshot */
1173 if (level == lowest_level)
1175 bytenr = btrfs_node_blockptr(b, slot);
1176 ptr_gen = btrfs_node_ptr_generation(b, slot);
1178 reada_for_search(root, p, level, slot,
1180 b = read_tree_block(root, bytenr,
1181 btrfs_level_size(root, level - 1));
1182 if (ptr_gen != btrfs_header_generation(b)) {
1183 printk("block %llu bad gen wanted %llu "
1185 (unsigned long long)b->start,
1186 (unsigned long long)ptr_gen,
1187 (unsigned long long)btrfs_header_generation(b));
1190 p->slots[level] = slot;
1191 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1192 sizeof(struct btrfs_item) + ins_len) {
1193 int sret = split_leaf(trans, root, key,
1194 p, ins_len, ret == 0);
1206 * adjust the pointers going up the tree, starting at level
1207 * making sure the right key of each node is points to 'key'.
1208 * This is used after shifting pointers to the left, so it stops
1209 * fixing up pointers when a given leaf/node is not in slot 0 of the
1212 * If this fails to write a tree block, it returns -1, but continues
1213 * fixing up the blocks in ram so the tree is consistent.
1215 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1216 struct btrfs_root *root, struct btrfs_path *path,
1217 struct btrfs_disk_key *key, int level)
1221 struct extent_buffer *t;
1223 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1224 int tslot = path->slots[i];
1225 if (!path->nodes[i])
1228 btrfs_set_node_key(t, key, tslot);
1229 btrfs_mark_buffer_dirty(path->nodes[i]);
1237 * try to push data from one node into the next node left in the
1240 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1241 * error, and > 0 if there was no room in the left hand block.
1243 static int push_node_left(struct btrfs_trans_handle *trans,
1244 struct btrfs_root *root, struct extent_buffer *dst,
1245 struct extent_buffer *src)
1252 src_nritems = btrfs_header_nritems(src);
1253 dst_nritems = btrfs_header_nritems(dst);
1254 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1255 WARN_ON(btrfs_header_generation(src) != trans->transid);
1256 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1258 if (push_items <= 0) {
1262 if (src_nritems < push_items)
1263 push_items = src_nritems;
1265 copy_extent_buffer(dst, src,
1266 btrfs_node_key_ptr_offset(dst_nritems),
1267 btrfs_node_key_ptr_offset(0),
1268 push_items * sizeof(struct btrfs_key_ptr));
1270 if (push_items < src_nritems) {
1271 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1272 btrfs_node_key_ptr_offset(push_items),
1273 (src_nritems - push_items) *
1274 sizeof(struct btrfs_key_ptr));
1276 btrfs_set_header_nritems(src, src_nritems - push_items);
1277 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1278 btrfs_mark_buffer_dirty(src);
1279 btrfs_mark_buffer_dirty(dst);
1284 * try to push data from one node into the next node right in the
1287 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1288 * error, and > 0 if there was no room in the right hand block.
1290 * this will only push up to 1/2 the contents of the left node over
1292 static int balance_node_right(struct btrfs_trans_handle *trans,
1293 struct btrfs_root *root,
1294 struct extent_buffer *dst,
1295 struct extent_buffer *src)
1303 WARN_ON(btrfs_header_generation(src) != trans->transid);
1304 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1306 src_nritems = btrfs_header_nritems(src);
1307 dst_nritems = btrfs_header_nritems(dst);
1308 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1309 if (push_items <= 0)
1312 max_push = src_nritems / 2 + 1;
1313 /* don't try to empty the node */
1314 if (max_push >= src_nritems)
1317 if (max_push < push_items)
1318 push_items = max_push;
1320 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1321 btrfs_node_key_ptr_offset(0),
1323 sizeof(struct btrfs_key_ptr));
1325 copy_extent_buffer(dst, src,
1326 btrfs_node_key_ptr_offset(0),
1327 btrfs_node_key_ptr_offset(src_nritems - push_items),
1328 push_items * sizeof(struct btrfs_key_ptr));
1330 btrfs_set_header_nritems(src, src_nritems - push_items);
1331 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1333 btrfs_mark_buffer_dirty(src);
1334 btrfs_mark_buffer_dirty(dst);
1339 * helper function to insert a new root level in the tree.
1340 * A new node is allocated, and a single item is inserted to
1341 * point to the existing root
1343 * returns zero on success or < 0 on failure.
1345 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1346 struct btrfs_root *root,
1347 struct btrfs_path *path, int level)
1351 struct extent_buffer *lower;
1352 struct extent_buffer *c;
1353 struct btrfs_disk_key lower_key;
1355 BUG_ON(path->nodes[level]);
1356 BUG_ON(path->nodes[level-1] != root->node);
1359 root_gen = trans->transid;
1363 lower = path->nodes[level-1];
1365 btrfs_item_key(lower, &lower_key, 0);
1367 btrfs_node_key(lower, &lower_key, 0);
1369 c = __btrfs_alloc_free_block(trans, root, root->nodesize,
1370 root->root_key.objectid,
1371 root_gen, lower_key.objectid, level,
1372 root->node->start, 0);
1375 memset_extent_buffer(c, 0, 0, root->nodesize);
1376 btrfs_set_header_nritems(c, 1);
1377 btrfs_set_header_level(c, level);
1378 btrfs_set_header_bytenr(c, c->start);
1379 btrfs_set_header_generation(c, trans->transid);
1380 btrfs_set_header_owner(c, root->root_key.objectid);
1382 write_extent_buffer(c, root->fs_info->fsid,
1383 (unsigned long)btrfs_header_fsid(c),
1385 btrfs_set_node_key(c, &lower_key, 0);
1386 btrfs_set_node_blockptr(c, 0, lower->start);
1387 lower_gen = btrfs_header_generation(lower);
1388 WARN_ON(lower_gen == 0);
1390 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1392 btrfs_mark_buffer_dirty(c);
1394 /* the super has an extra ref to root->node */
1395 free_extent_buffer(root->node);
1397 add_root_to_dirty_list(root);
1398 extent_buffer_get(c);
1399 path->nodes[level] = c;
1400 path->slots[level] = 0;
1402 if (root->ref_cows && lower_gen != trans->transid) {
1403 struct btrfs_path *back_path = btrfs_alloc_path();
1405 ret = btrfs_insert_extent_backref(trans,
1406 root->fs_info->extent_root,
1408 root->root_key.objectid,
1409 trans->transid, 0, 0);
1411 btrfs_free_path(back_path);
1417 * worker function to insert a single pointer in a node.
1418 * the node should have enough room for the pointer already
1420 * slot and level indicate where you want the key to go, and
1421 * blocknr is the block the key points to.
1423 * returns zero on success and < 0 on any error
1425 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1426 *root, struct btrfs_path *path, struct btrfs_disk_key
1427 *key, u64 bytenr, int slot, int level)
1429 struct extent_buffer *lower;
1432 BUG_ON(!path->nodes[level]);
1433 lower = path->nodes[level];
1434 nritems = btrfs_header_nritems(lower);
1437 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1439 if (slot != nritems) {
1440 memmove_extent_buffer(lower,
1441 btrfs_node_key_ptr_offset(slot + 1),
1442 btrfs_node_key_ptr_offset(slot),
1443 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1445 btrfs_set_node_key(lower, key, slot);
1446 btrfs_set_node_blockptr(lower, slot, bytenr);
1447 WARN_ON(trans->transid == 0);
1448 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1449 btrfs_set_header_nritems(lower, nritems + 1);
1450 btrfs_mark_buffer_dirty(lower);
1455 * split the node at the specified level in path in two.
1456 * The path is corrected to point to the appropriate node after the split
1458 * Before splitting this tries to make some room in the node by pushing
1459 * left and right, if either one works, it returns right away.
1461 * returns 0 on success and < 0 on failure
1463 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1464 *root, struct btrfs_path *path, int level)
1467 struct extent_buffer *c;
1468 struct extent_buffer *split;
1469 struct btrfs_disk_key disk_key;
1475 c = path->nodes[level];
1476 WARN_ON(btrfs_header_generation(c) != trans->transid);
1477 if (c == root->node) {
1478 /* trying to split the root, lets make a new one */
1479 ret = insert_new_root(trans, root, path, level + 1);
1483 ret = push_nodes_for_insert(trans, root, path, level);
1484 c = path->nodes[level];
1485 if (!ret && btrfs_header_nritems(c) <
1486 BTRFS_NODEPTRS_PER_BLOCK(root) - 1)
1492 c_nritems = btrfs_header_nritems(c);
1494 root_gen = trans->transid;
1498 btrfs_node_key(c, &disk_key, 0);
1499 split = __btrfs_alloc_free_block(trans, root, root->nodesize,
1500 root->root_key.objectid,
1502 btrfs_disk_key_objectid(&disk_key),
1503 level, c->start, 0);
1505 return PTR_ERR(split);
1507 btrfs_set_header_flags(split, btrfs_header_flags(c));
1508 btrfs_set_header_level(split, btrfs_header_level(c));
1509 btrfs_set_header_bytenr(split, split->start);
1510 btrfs_set_header_generation(split, trans->transid);
1511 btrfs_set_header_owner(split, root->root_key.objectid);
1512 btrfs_set_header_flags(split, 0);
1513 write_extent_buffer(split, root->fs_info->fsid,
1514 (unsigned long)btrfs_header_fsid(split),
1517 mid = (c_nritems + 1) / 2;
1519 copy_extent_buffer(split, c,
1520 btrfs_node_key_ptr_offset(0),
1521 btrfs_node_key_ptr_offset(mid),
1522 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1523 btrfs_set_header_nritems(split, c_nritems - mid);
1524 btrfs_set_header_nritems(c, mid);
1527 btrfs_mark_buffer_dirty(c);
1528 btrfs_mark_buffer_dirty(split);
1530 btrfs_node_key(split, &disk_key, 0);
1531 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1532 path->slots[level + 1] + 1,
1537 if (path->slots[level] >= mid) {
1538 path->slots[level] -= mid;
1539 free_extent_buffer(c);
1540 path->nodes[level] = split;
1541 path->slots[level + 1] += 1;
1543 free_extent_buffer(split);
1549 * how many bytes are required to store the items in a leaf. start
1550 * and nr indicate which items in the leaf to check. This totals up the
1551 * space used both by the item structs and the item data
1553 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1556 int nritems = btrfs_header_nritems(l);
1557 int end = min(nritems, start + nr) - 1;
1561 data_len = btrfs_item_end_nr(l, start);
1562 data_len = data_len - btrfs_item_offset_nr(l, end);
1563 data_len += sizeof(struct btrfs_item) * nr;
1564 WARN_ON(data_len < 0);
1569 * The space between the end of the leaf items and
1570 * the start of the leaf data. IOW, how much room
1571 * the leaf has left for both items and data
1573 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1575 int nritems = btrfs_header_nritems(leaf);
1577 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1579 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1580 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1581 leaf_space_used(leaf, 0, nritems), nritems);
1587 * push some data in the path leaf to the right, trying to free up at
1588 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1590 * returns 1 if the push failed because the other node didn't have enough
1591 * room, 0 if everything worked out and < 0 if there were major errors.
1593 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1594 *root, struct btrfs_path *path, int data_size,
1597 struct extent_buffer *left = path->nodes[0];
1598 struct extent_buffer *right;
1599 struct extent_buffer *upper;
1600 struct btrfs_disk_key disk_key;
1606 struct btrfs_item *item;
1614 slot = path->slots[1];
1615 if (!path->nodes[1]) {
1618 upper = path->nodes[1];
1619 if (slot >= btrfs_header_nritems(upper) - 1)
1622 right = read_tree_block(root, btrfs_node_blockptr(upper, slot + 1),
1624 free_space = btrfs_leaf_free_space(root, right);
1625 if (free_space < data_size + sizeof(struct btrfs_item)) {
1626 free_extent_buffer(right);
1630 /* cow and double check */
1631 ret = btrfs_cow_block(trans, root, right, upper,
1634 free_extent_buffer(right);
1637 free_space = btrfs_leaf_free_space(root, right);
1638 if (free_space < data_size + sizeof(struct btrfs_item)) {
1639 free_extent_buffer(right);
1643 left_nritems = btrfs_header_nritems(left);
1644 if (left_nritems == 0) {
1645 free_extent_buffer(right);
1654 i = left_nritems - 1;
1656 item = btrfs_item_nr(left, i);
1658 if (path->slots[0] == i)
1659 push_space += data_size + sizeof(*item);
1661 if (!left->map_token) {
1662 map_extent_buffer(left, (unsigned long)item,
1663 sizeof(struct btrfs_item),
1664 &left->map_token, &left->kaddr,
1665 &left->map_start, &left->map_len,
1669 this_item_size = btrfs_item_size(left, item);
1670 if (this_item_size + sizeof(*item) + push_space > free_space)
1673 push_space += this_item_size + sizeof(*item);
1678 if (left->map_token) {
1679 unmap_extent_buffer(left, left->map_token, KM_USER1);
1680 left->map_token = NULL;
1683 if (push_items == 0) {
1684 free_extent_buffer(right);
1688 if (!empty && push_items == left_nritems)
1691 /* push left to right */
1692 right_nritems = btrfs_header_nritems(right);
1694 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1695 push_space -= leaf_data_end(root, left);
1697 /* make room in the right data area */
1698 data_end = leaf_data_end(root, right);
1699 memmove_extent_buffer(right,
1700 btrfs_leaf_data(right) + data_end - push_space,
1701 btrfs_leaf_data(right) + data_end,
1702 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1704 /* copy from the left data area */
1705 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1706 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1707 btrfs_leaf_data(left) + leaf_data_end(root, left),
1710 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1711 btrfs_item_nr_offset(0),
1712 right_nritems * sizeof(struct btrfs_item));
1714 /* copy the items from left to right */
1715 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1716 btrfs_item_nr_offset(left_nritems - push_items),
1717 push_items * sizeof(struct btrfs_item));
1719 /* update the item pointers */
1720 right_nritems += push_items;
1721 btrfs_set_header_nritems(right, right_nritems);
1722 push_space = BTRFS_LEAF_DATA_SIZE(root);
1723 for (i = 0; i < right_nritems; i++) {
1724 item = btrfs_item_nr(right, i);
1725 if (!right->map_token) {
1726 map_extent_buffer(right, (unsigned long)item,
1727 sizeof(struct btrfs_item),
1728 &right->map_token, &right->kaddr,
1729 &right->map_start, &right->map_len,
1732 push_space -= btrfs_item_size(right, item);
1733 btrfs_set_item_offset(right, item, push_space);
1736 if (right->map_token) {
1737 unmap_extent_buffer(right, right->map_token, KM_USER1);
1738 right->map_token = NULL;
1740 left_nritems -= push_items;
1741 btrfs_set_header_nritems(left, left_nritems);
1744 btrfs_mark_buffer_dirty(left);
1745 btrfs_mark_buffer_dirty(right);
1747 btrfs_item_key(right, &disk_key, 0);
1748 btrfs_set_node_key(upper, &disk_key, slot + 1);
1749 btrfs_mark_buffer_dirty(upper);
1751 /* then fixup the leaf pointer in the path */
1752 if (path->slots[0] >= left_nritems) {
1753 path->slots[0] -= left_nritems;
1754 free_extent_buffer(path->nodes[0]);
1755 path->nodes[0] = right;
1756 path->slots[1] += 1;
1758 free_extent_buffer(right);
1763 * push some data in the path leaf to the left, trying to free up at
1764 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1766 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1767 *root, struct btrfs_path *path, int data_size,
1770 struct btrfs_disk_key disk_key;
1771 struct extent_buffer *right = path->nodes[0];
1772 struct extent_buffer *left;
1778 struct btrfs_item *item;
1779 u32 old_left_nritems;
1785 u32 old_left_item_size;
1787 slot = path->slots[1];
1790 if (!path->nodes[1])
1793 right_nritems = btrfs_header_nritems(right);
1794 if (right_nritems == 0) {
1798 left = read_tree_block(root, btrfs_node_blockptr(path->nodes[1],
1799 slot - 1), root->leafsize);
1800 free_space = btrfs_leaf_free_space(root, left);
1801 if (free_space < data_size + sizeof(struct btrfs_item)) {
1802 free_extent_buffer(left);
1806 /* cow and double check */
1807 ret = btrfs_cow_block(trans, root, left,
1808 path->nodes[1], slot - 1, &left);
1810 /* we hit -ENOSPC, but it isn't fatal here */
1811 free_extent_buffer(left);
1815 free_space = btrfs_leaf_free_space(root, left);
1816 if (free_space < data_size + sizeof(struct btrfs_item)) {
1817 free_extent_buffer(left);
1824 nr = right_nritems - 1;
1826 for (i = 0; i < nr; i++) {
1827 item = btrfs_item_nr(right, i);
1828 if (!right->map_token) {
1829 map_extent_buffer(right, (unsigned long)item,
1830 sizeof(struct btrfs_item),
1831 &right->map_token, &right->kaddr,
1832 &right->map_start, &right->map_len,
1836 if (path->slots[0] == i)
1837 push_space += data_size + sizeof(*item);
1839 this_item_size = btrfs_item_size(right, item);
1840 if (this_item_size + sizeof(*item) + push_space > free_space)
1844 push_space += this_item_size + sizeof(*item);
1847 if (right->map_token) {
1848 unmap_extent_buffer(right, right->map_token, KM_USER1);
1849 right->map_token = NULL;
1852 if (push_items == 0) {
1853 free_extent_buffer(left);
1856 if (!empty && push_items == btrfs_header_nritems(right))
1859 /* push data from right to left */
1860 copy_extent_buffer(left, right,
1861 btrfs_item_nr_offset(btrfs_header_nritems(left)),
1862 btrfs_item_nr_offset(0),
1863 push_items * sizeof(struct btrfs_item));
1865 push_space = BTRFS_LEAF_DATA_SIZE(root) -
1866 btrfs_item_offset_nr(right, push_items -1);
1868 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
1869 leaf_data_end(root, left) - push_space,
1870 btrfs_leaf_data(right) +
1871 btrfs_item_offset_nr(right, push_items - 1),
1873 old_left_nritems = btrfs_header_nritems(left);
1874 BUG_ON(old_left_nritems < 0);
1876 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
1877 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
1880 item = btrfs_item_nr(left, i);
1881 if (!left->map_token) {
1882 map_extent_buffer(left, (unsigned long)item,
1883 sizeof(struct btrfs_item),
1884 &left->map_token, &left->kaddr,
1885 &left->map_start, &left->map_len,
1889 ioff = btrfs_item_offset(left, item);
1890 btrfs_set_item_offset(left, item,
1891 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
1893 btrfs_set_header_nritems(left, old_left_nritems + push_items);
1894 if (left->map_token) {
1895 unmap_extent_buffer(left, left->map_token, KM_USER1);
1896 left->map_token = NULL;
1899 /* fixup right node */
1900 if (push_items > right_nritems) {
1901 printk("push items %d nr %u\n", push_items, right_nritems);
1905 if (push_items < right_nritems) {
1906 push_space = btrfs_item_offset_nr(right, push_items - 1) -
1907 leaf_data_end(root, right);
1908 memmove_extent_buffer(right, btrfs_leaf_data(right) +
1909 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1910 btrfs_leaf_data(right) +
1911 leaf_data_end(root, right), push_space);
1913 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
1914 btrfs_item_nr_offset(push_items),
1915 (btrfs_header_nritems(right) - push_items) *
1916 sizeof(struct btrfs_item));
1918 right_nritems -= push_items;
1919 btrfs_set_header_nritems(right, right_nritems);
1920 push_space = BTRFS_LEAF_DATA_SIZE(root);
1921 for (i = 0; i < right_nritems; i++) {
1922 item = btrfs_item_nr(right, i);
1924 if (!right->map_token) {
1925 map_extent_buffer(right, (unsigned long)item,
1926 sizeof(struct btrfs_item),
1927 &right->map_token, &right->kaddr,
1928 &right->map_start, &right->map_len,
1932 push_space = push_space - btrfs_item_size(right, item);
1933 btrfs_set_item_offset(right, item, push_space);
1935 if (right->map_token) {
1936 unmap_extent_buffer(right, right->map_token, KM_USER1);
1937 right->map_token = NULL;
1940 btrfs_mark_buffer_dirty(left);
1942 btrfs_mark_buffer_dirty(right);
1944 btrfs_item_key(right, &disk_key, 0);
1945 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
1949 /* then fixup the leaf pointer in the path */
1950 if (path->slots[0] < push_items) {
1951 path->slots[0] += old_left_nritems;
1952 free_extent_buffer(path->nodes[0]);
1953 path->nodes[0] = left;
1954 path->slots[1] -= 1;
1956 free_extent_buffer(left);
1957 path->slots[0] -= push_items;
1959 BUG_ON(path->slots[0] < 0);
1964 * split the path's leaf in two, making sure there is at least data_size
1965 * available for the resulting leaf level of the path.
1967 * returns 0 if all went well and < 0 on failure.
1969 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
1970 *root, struct btrfs_key *ins_key,
1971 struct btrfs_path *path, int data_size, int extend)
1974 struct extent_buffer *l;
1978 struct extent_buffer *right;
1979 int space_needed = data_size + sizeof(struct btrfs_item);
1986 int num_doubles = 0;
1987 struct btrfs_disk_key disk_key;
1990 space_needed = data_size;
1993 root_gen = trans->transid;
1997 /* first try to make some room by pushing left and right */
1998 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
1999 wret = push_leaf_right(trans, root, path, data_size, 0);
2004 wret = push_leaf_left(trans, root, path, data_size, 0);
2010 /* did the pushes work? */
2011 if (btrfs_leaf_free_space(root, l) >= space_needed)
2015 if (!path->nodes[1]) {
2016 ret = insert_new_root(trans, root, path, 1);
2023 slot = path->slots[0];
2024 nritems = btrfs_header_nritems(l);
2025 mid = (nritems + 1)/ 2;
2027 btrfs_item_key(l, &disk_key, 0);
2029 right = __btrfs_alloc_free_block(trans, root, root->leafsize,
2030 root->root_key.objectid,
2031 root_gen, disk_key.objectid, 0,
2033 if (IS_ERR(right)) {
2035 return PTR_ERR(right);
2038 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2039 btrfs_set_header_bytenr(right, right->start);
2040 btrfs_set_header_generation(right, trans->transid);
2041 btrfs_set_header_owner(right, root->root_key.objectid);
2042 btrfs_set_header_level(right, 0);
2043 write_extent_buffer(right, root->fs_info->fsid,
2044 (unsigned long)btrfs_header_fsid(right),
2048 leaf_space_used(l, mid, nritems - mid) + space_needed >
2049 BTRFS_LEAF_DATA_SIZE(root)) {
2050 if (slot >= nritems) {
2051 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2052 btrfs_set_header_nritems(right, 0);
2053 wret = insert_ptr(trans, root, path,
2054 &disk_key, right->start,
2055 path->slots[1] + 1, 1);
2058 free_extent_buffer(path->nodes[0]);
2059 path->nodes[0] = right;
2061 path->slots[1] += 1;
2062 btrfs_mark_buffer_dirty(right);
2066 if (mid != nritems &&
2067 leaf_space_used(l, mid, nritems - mid) +
2068 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2073 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2074 BTRFS_LEAF_DATA_SIZE(root)) {
2075 if (!extend && slot == 0) {
2076 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2077 btrfs_set_header_nritems(right, 0);
2078 wret = insert_ptr(trans, root, path,
2084 free_extent_buffer(path->nodes[0]);
2085 path->nodes[0] = right;
2087 if (path->slots[1] == 0) {
2088 wret = fixup_low_keys(trans, root,
2089 path, &disk_key, 1);
2093 btrfs_mark_buffer_dirty(right);
2095 } else if (extend && slot == 0) {
2099 if (mid != nritems &&
2100 leaf_space_used(l, mid, nritems - mid) +
2101 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2107 nritems = nritems - mid;
2108 btrfs_set_header_nritems(right, nritems);
2109 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2111 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2112 btrfs_item_nr_offset(mid),
2113 nritems * sizeof(struct btrfs_item));
2115 copy_extent_buffer(right, l,
2116 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2117 data_copy_size, btrfs_leaf_data(l) +
2118 leaf_data_end(root, l), data_copy_size);
2120 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2121 btrfs_item_end_nr(l, mid);
2123 for (i = 0; i < nritems; i++) {
2124 struct btrfs_item *item = btrfs_item_nr(right, i);
2127 if (!right->map_token) {
2128 map_extent_buffer(right, (unsigned long)item,
2129 sizeof(struct btrfs_item),
2130 &right->map_token, &right->kaddr,
2131 &right->map_start, &right->map_len,
2135 ioff = btrfs_item_offset(right, item);
2136 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2139 if (right->map_token) {
2140 unmap_extent_buffer(right, right->map_token, KM_USER1);
2141 right->map_token = NULL;
2144 btrfs_set_header_nritems(l, mid);
2146 btrfs_item_key(right, &disk_key, 0);
2147 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2148 path->slots[1] + 1, 1);
2152 btrfs_mark_buffer_dirty(right);
2153 btrfs_mark_buffer_dirty(l);
2154 BUG_ON(path->slots[0] != slot);
2157 free_extent_buffer(path->nodes[0]);
2158 path->nodes[0] = right;
2159 path->slots[0] -= mid;
2160 path->slots[1] += 1;
2162 free_extent_buffer(right);
2164 BUG_ON(path->slots[0] < 0);
2167 BUG_ON(num_doubles != 0);
2174 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2175 struct btrfs_root *root,
2176 struct btrfs_path *path,
2177 u32 new_size, int from_end)
2182 struct extent_buffer *leaf;
2183 struct btrfs_item *item;
2185 unsigned int data_end;
2186 unsigned int old_data_start;
2187 unsigned int old_size;
2188 unsigned int size_diff;
2191 slot_orig = path->slots[0];
2192 leaf = path->nodes[0];
2193 slot = path->slots[0];
2195 old_size = btrfs_item_size_nr(leaf, slot);
2196 if (old_size == new_size)
2199 nritems = btrfs_header_nritems(leaf);
2200 data_end = leaf_data_end(root, leaf);
2202 old_data_start = btrfs_item_offset_nr(leaf, slot);
2204 size_diff = old_size - new_size;
2207 BUG_ON(slot >= nritems);
2210 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2212 /* first correct the data pointers */
2213 for (i = slot; i < nritems; i++) {
2215 item = btrfs_item_nr(leaf, i);
2217 if (!leaf->map_token) {
2218 map_extent_buffer(leaf, (unsigned long)item,
2219 sizeof(struct btrfs_item),
2220 &leaf->map_token, &leaf->kaddr,
2221 &leaf->map_start, &leaf->map_len,
2225 ioff = btrfs_item_offset(leaf, item);
2226 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2229 if (leaf->map_token) {
2230 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2231 leaf->map_token = NULL;
2234 /* shift the data */
2236 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2237 data_end + size_diff, btrfs_leaf_data(leaf) +
2238 data_end, old_data_start + new_size - data_end);
2240 struct btrfs_disk_key disk_key;
2243 btrfs_item_key(leaf, &disk_key, slot);
2245 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2247 struct btrfs_file_extent_item *fi;
2249 fi = btrfs_item_ptr(leaf, slot,
2250 struct btrfs_file_extent_item);
2251 fi = (struct btrfs_file_extent_item *)(
2252 (unsigned long)fi - size_diff);
2254 if (btrfs_file_extent_type(leaf, fi) ==
2255 BTRFS_FILE_EXTENT_INLINE) {
2256 ptr = btrfs_item_ptr_offset(leaf, slot);
2257 memmove_extent_buffer(leaf, ptr,
2259 offsetof(struct btrfs_file_extent_item,
2264 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2265 data_end + size_diff, btrfs_leaf_data(leaf) +
2266 data_end, old_data_start - data_end);
2268 offset = btrfs_disk_key_offset(&disk_key);
2269 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2270 btrfs_set_item_key(leaf, &disk_key, slot);
2272 fixup_low_keys(trans, root, path, &disk_key, 1);
2275 item = btrfs_item_nr(leaf, slot);
2276 btrfs_set_item_size(leaf, item, new_size);
2277 btrfs_mark_buffer_dirty(leaf);
2280 if (btrfs_leaf_free_space(root, leaf) < 0) {
2281 btrfs_print_leaf(root, leaf);
2287 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2288 struct btrfs_root *root, struct btrfs_path *path,
2294 struct extent_buffer *leaf;
2295 struct btrfs_item *item;
2297 unsigned int data_end;
2298 unsigned int old_data;
2299 unsigned int old_size;
2302 slot_orig = path->slots[0];
2303 leaf = path->nodes[0];
2305 nritems = btrfs_header_nritems(leaf);
2306 data_end = leaf_data_end(root, leaf);
2308 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2309 btrfs_print_leaf(root, leaf);
2312 slot = path->slots[0];
2313 old_data = btrfs_item_end_nr(leaf, slot);
2316 if (slot >= nritems) {
2317 btrfs_print_leaf(root, leaf);
2318 printk("slot %d too large, nritems %d\n", slot, nritems);
2323 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2325 /* first correct the data pointers */
2326 for (i = slot; i < nritems; i++) {
2328 item = btrfs_item_nr(leaf, i);
2330 if (!leaf->map_token) {
2331 map_extent_buffer(leaf, (unsigned long)item,
2332 sizeof(struct btrfs_item),
2333 &leaf->map_token, &leaf->kaddr,
2334 &leaf->map_start, &leaf->map_len,
2337 ioff = btrfs_item_offset(leaf, item);
2338 btrfs_set_item_offset(leaf, item, ioff - data_size);
2341 if (leaf->map_token) {
2342 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2343 leaf->map_token = NULL;
2346 /* shift the data */
2347 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2348 data_end - data_size, btrfs_leaf_data(leaf) +
2349 data_end, old_data - data_end);
2351 data_end = old_data;
2352 old_size = btrfs_item_size_nr(leaf, slot);
2353 item = btrfs_item_nr(leaf, slot);
2354 btrfs_set_item_size(leaf, item, old_size + data_size);
2355 btrfs_mark_buffer_dirty(leaf);
2358 if (btrfs_leaf_free_space(root, leaf) < 0) {
2359 btrfs_print_leaf(root, leaf);
2366 * Given a key and some data, insert an item into the tree.
2367 * This does all the path init required, making room in the tree if needed.
2369 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2370 struct btrfs_root *root,
2371 struct btrfs_path *path,
2372 struct btrfs_key *cpu_key, u32 *data_size,
2375 struct extent_buffer *leaf;
2376 struct btrfs_item *item;
2384 unsigned int data_end;
2385 struct btrfs_disk_key disk_key;
2387 for (i = 0; i < nr; i++) {
2388 total_data += data_size[i];
2391 /* create a root if there isn't one */
2395 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2396 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2403 slot_orig = path->slots[0];
2404 leaf = path->nodes[0];
2406 nritems = btrfs_header_nritems(leaf);
2407 data_end = leaf_data_end(root, leaf);
2409 if (btrfs_leaf_free_space(root, leaf) <
2410 sizeof(struct btrfs_item) + total_size) {
2411 btrfs_print_leaf(root, leaf);
2412 printk("not enough freespace need %u have %d\n",
2413 total_size, btrfs_leaf_free_space(root, leaf));
2417 slot = path->slots[0];
2420 if (slot != nritems) {
2422 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2424 if (old_data < data_end) {
2425 btrfs_print_leaf(root, leaf);
2426 printk("slot %d old_data %d data_end %d\n",
2427 slot, old_data, data_end);
2431 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2433 /* first correct the data pointers */
2434 WARN_ON(leaf->map_token);
2435 for (i = slot; i < nritems; i++) {
2438 item = btrfs_item_nr(leaf, i);
2439 if (!leaf->map_token) {
2440 map_extent_buffer(leaf, (unsigned long)item,
2441 sizeof(struct btrfs_item),
2442 &leaf->map_token, &leaf->kaddr,
2443 &leaf->map_start, &leaf->map_len,
2447 ioff = btrfs_item_offset(leaf, item);
2448 btrfs_set_item_offset(leaf, item, ioff - total_data);
2450 if (leaf->map_token) {
2451 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2452 leaf->map_token = NULL;
2455 /* shift the items */
2456 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2457 btrfs_item_nr_offset(slot),
2458 (nritems - slot) * sizeof(struct btrfs_item));
2460 /* shift the data */
2461 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2462 data_end - total_data, btrfs_leaf_data(leaf) +
2463 data_end, old_data - data_end);
2464 data_end = old_data;
2467 /* setup the item for the new data */
2468 for (i = 0; i < nr; i++) {
2469 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2470 btrfs_set_item_key(leaf, &disk_key, slot + i);
2471 item = btrfs_item_nr(leaf, slot + i);
2472 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2473 data_end -= data_size[i];
2474 btrfs_set_item_size(leaf, item, data_size[i]);
2476 btrfs_set_header_nritems(leaf, nritems + nr);
2477 btrfs_mark_buffer_dirty(leaf);
2481 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2482 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2485 if (btrfs_leaf_free_space(root, leaf) < 0) {
2486 btrfs_print_leaf(root, leaf);
2495 * Given a key and some data, insert an item into the tree.
2496 * This does all the path init required, making room in the tree if needed.
2498 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2499 *root, struct btrfs_key *cpu_key, void *data, u32
2503 struct btrfs_path *path;
2504 struct extent_buffer *leaf;
2507 path = btrfs_alloc_path();
2509 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2511 leaf = path->nodes[0];
2512 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2513 write_extent_buffer(leaf, data, ptr, data_size);
2514 btrfs_mark_buffer_dirty(leaf);
2516 btrfs_free_path(path);
2521 * delete the pointer from a given node.
2523 * If the delete empties a node, the node is removed from the tree,
2524 * continuing all the way the root if required. The root is converted into
2525 * a leaf if all the nodes are emptied.
2527 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2528 struct btrfs_path *path, int level, int slot)
2530 struct extent_buffer *parent = path->nodes[level];
2535 nritems = btrfs_header_nritems(parent);
2536 if (slot != nritems -1) {
2537 memmove_extent_buffer(parent,
2538 btrfs_node_key_ptr_offset(slot),
2539 btrfs_node_key_ptr_offset(slot + 1),
2540 sizeof(struct btrfs_key_ptr) *
2541 (nritems - slot - 1));
2544 btrfs_set_header_nritems(parent, nritems);
2545 if (nritems == 0 && parent == root->node) {
2546 BUG_ON(btrfs_header_level(root->node) != 1);
2547 /* just turn the root into a leaf and break */
2548 btrfs_set_header_level(root->node, 0);
2549 } else if (slot == 0) {
2550 struct btrfs_disk_key disk_key;
2552 btrfs_node_key(parent, &disk_key, 0);
2553 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2557 btrfs_mark_buffer_dirty(parent);
2562 * delete the item at the leaf level in path. If that empties
2563 * the leaf, remove it from the tree
2565 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2566 struct btrfs_path *path, int slot, int nr)
2568 struct extent_buffer *leaf;
2569 struct btrfs_item *item;
2577 leaf = path->nodes[0];
2578 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2580 for (i = 0; i < nr; i++)
2581 dsize += btrfs_item_size_nr(leaf, slot + i);
2583 nritems = btrfs_header_nritems(leaf);
2585 if (slot + nr != nritems) {
2587 int data_end = leaf_data_end(root, leaf);
2589 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2591 btrfs_leaf_data(leaf) + data_end,
2592 last_off - data_end);
2594 for (i = slot + nr; i < nritems; i++) {
2597 item = btrfs_item_nr(leaf, i);
2598 if (!leaf->map_token) {
2599 map_extent_buffer(leaf, (unsigned long)item,
2600 sizeof(struct btrfs_item),
2601 &leaf->map_token, &leaf->kaddr,
2602 &leaf->map_start, &leaf->map_len,
2605 ioff = btrfs_item_offset(leaf, item);
2606 btrfs_set_item_offset(leaf, item, ioff + dsize);
2609 if (leaf->map_token) {
2610 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2611 leaf->map_token = NULL;
2614 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2615 btrfs_item_nr_offset(slot + nr),
2616 sizeof(struct btrfs_item) *
2617 (nritems - slot - nr));
2619 btrfs_set_header_nritems(leaf, nritems - nr);
2622 /* delete the leaf if we've emptied it */
2624 if (leaf == root->node) {
2625 btrfs_set_header_level(leaf, 0);
2627 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2628 clean_tree_block(trans, root, leaf);
2629 wait_on_tree_block_writeback(root, leaf);
2630 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2633 wret = btrfs_free_extent(trans, root,
2634 leaf->start, leaf->len,
2635 btrfs_header_owner(path->nodes[1]),
2641 int used = leaf_space_used(leaf, 0, nritems);
2643 struct btrfs_disk_key disk_key;
2645 btrfs_item_key(leaf, &disk_key, 0);
2646 wret = fixup_low_keys(trans, root, path,
2652 /* delete the leaf if it is mostly empty */
2653 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2654 /* push_leaf_left fixes the path.
2655 * make sure the path still points to our leaf
2656 * for possible call to del_ptr below
2658 slot = path->slots[1];
2659 extent_buffer_get(leaf);
2661 wret = push_leaf_left(trans, root, path, 1, 1);
2662 if (wret < 0 && wret != -ENOSPC)
2665 if (path->nodes[0] == leaf &&
2666 btrfs_header_nritems(leaf)) {
2667 wret = push_leaf_right(trans, root, path, 1, 1);
2668 if (wret < 0 && wret != -ENOSPC)
2672 if (btrfs_header_nritems(leaf) == 0) {
2674 u64 bytenr = leaf->start;
2675 u32 blocksize = leaf->len;
2677 root_gen = btrfs_header_generation(
2680 clean_tree_block(trans, root, leaf);
2681 wait_on_tree_block_writeback(root, leaf);
2683 wret = del_ptr(trans, root, path, 1, slot);
2687 free_extent_buffer(leaf);
2688 wret = btrfs_free_extent(trans, root, bytenr,
2690 btrfs_header_owner(path->nodes[1]),
2695 btrfs_mark_buffer_dirty(leaf);
2696 free_extent_buffer(leaf);
2699 btrfs_mark_buffer_dirty(leaf);
2706 * walk up the tree as far as required to find the previous leaf.
2707 * returns 0 if it found something or 1 if there are no lesser leaves.
2708 * returns < 0 on io errors.
2710 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2715 struct extent_buffer *c;
2716 struct extent_buffer *next = NULL;
2718 while(level < BTRFS_MAX_LEVEL) {
2719 if (!path->nodes[level])
2722 slot = path->slots[level];
2723 c = path->nodes[level];
2726 if (level == BTRFS_MAX_LEVEL)
2732 bytenr = btrfs_node_blockptr(c, slot);
2734 free_extent_buffer(next);
2736 next = read_tree_block(root, bytenr,
2737 btrfs_level_size(root, level - 1));
2740 path->slots[level] = slot;
2743 c = path->nodes[level];
2744 free_extent_buffer(c);
2745 slot = btrfs_header_nritems(next);
2748 path->nodes[level] = next;
2749 path->slots[level] = slot;
2752 next = read_tree_block(root, btrfs_node_blockptr(next, slot),
2753 btrfs_level_size(root, level - 1));
2759 * walk up the tree as far as required to find the next leaf.
2760 * returns 0 if it found something or 1 if there are no greater leaves.
2761 * returns < 0 on io errors.
2763 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2768 struct extent_buffer *c;
2769 struct extent_buffer *next = NULL;
2771 while(level < BTRFS_MAX_LEVEL) {
2772 if (!path->nodes[level])
2775 slot = path->slots[level] + 1;
2776 c = path->nodes[level];
2777 if (slot >= btrfs_header_nritems(c)) {
2779 if (level == BTRFS_MAX_LEVEL)
2784 bytenr = btrfs_node_blockptr(c, slot);
2786 free_extent_buffer(next);
2789 reada_for_search(root, path, level, slot, 0);
2791 next = read_tree_block(root, bytenr,
2792 btrfs_level_size(root, level -1));
2795 path->slots[level] = slot;
2798 c = path->nodes[level];
2799 free_extent_buffer(c);
2800 path->nodes[level] = next;
2801 path->slots[level] = 0;
2805 reada_for_search(root, path, level, 0, 0);
2806 next = read_tree_block(root, btrfs_node_blockptr(next, 0),
2807 btrfs_level_size(root, level - 1));
2812 int btrfs_previous_item(struct btrfs_root *root,
2813 struct btrfs_path *path, u64 min_objectid,
2816 struct btrfs_key found_key;
2817 struct extent_buffer *leaf;
2821 if (path->slots[0] == 0) {
2822 ret = btrfs_prev_leaf(root, path);
2828 leaf = path->nodes[0];
2829 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2830 if (found_key.type == type)