2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
26 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
27 *root, struct btrfs_path *path, int level);
28 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
29 *root, struct btrfs_key *ins_key,
30 struct btrfs_path *path, int data_size, int extend);
31 static int push_node_left(struct btrfs_trans_handle *trans,
32 struct btrfs_root *root, struct extent_buffer *dst,
33 struct extent_buffer *src, int empty);
34 static int balance_node_right(struct btrfs_trans_handle *trans,
35 struct btrfs_root *root,
36 struct extent_buffer *dst_buf,
37 struct extent_buffer *src_buf);
38 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
39 struct btrfs_path *path, int level, int slot);
41 inline void btrfs_init_path(struct btrfs_path *p)
43 memset(p, 0, sizeof(*p));
46 struct btrfs_path *btrfs_alloc_path(void)
48 struct btrfs_path *path;
49 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
51 btrfs_init_path(path);
57 void btrfs_free_path(struct btrfs_path *p)
59 btrfs_release_path(NULL, p);
60 kmem_cache_free(btrfs_path_cachep, p);
63 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
66 int keep = p->keep_locks;
67 int skip = p->skip_locking;
69 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
73 btrfs_tree_unlock(p->nodes[i]);
76 free_extent_buffer(p->nodes[i]);
78 memset(p, 0, sizeof(*p));
80 p->skip_locking = skip;
83 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
85 struct extent_buffer *eb;
86 spin_lock(&root->node_lock);
88 extent_buffer_get(eb);
89 spin_unlock(&root->node_lock);
93 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
95 struct extent_buffer *eb;
98 eb = btrfs_root_node(root);
101 spin_lock(&root->node_lock);
102 if (eb == root->node) {
103 spin_unlock(&root->node_lock);
106 spin_unlock(&root->node_lock);
108 btrfs_tree_unlock(eb);
109 free_extent_buffer(eb);
114 static void add_root_to_dirty_list(struct btrfs_root *root)
116 if (root->track_dirty && list_empty(&root->dirty_list)) {
117 list_add(&root->dirty_list,
118 &root->fs_info->dirty_cowonly_roots);
122 int btrfs_copy_root(struct btrfs_trans_handle *trans,
123 struct btrfs_root *root,
124 struct extent_buffer *buf,
125 struct extent_buffer **cow_ret, u64 new_root_objectid)
127 struct extent_buffer *cow;
131 struct btrfs_key first_key;
132 struct btrfs_root *new_root;
134 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
138 memcpy(new_root, root, sizeof(*new_root));
139 new_root->root_key.objectid = new_root_objectid;
141 WARN_ON(root->ref_cows && trans->transid !=
142 root->fs_info->running_transaction->transid);
143 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
145 level = btrfs_header_level(buf);
146 nritems = btrfs_header_nritems(buf);
149 btrfs_item_key_to_cpu(buf, &first_key, 0);
151 btrfs_node_key_to_cpu(buf, &first_key, 0);
153 first_key.objectid = 0;
155 cow = btrfs_alloc_free_block(trans, new_root, buf->len,
157 trans->transid, first_key.objectid,
158 level, buf->start, 0);
164 copy_extent_buffer(cow, buf, 0, 0, cow->len);
165 btrfs_set_header_bytenr(cow, cow->start);
166 btrfs_set_header_generation(cow, trans->transid);
167 btrfs_set_header_owner(cow, new_root_objectid);
168 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
170 WARN_ON(btrfs_header_generation(buf) > trans->transid);
171 ret = btrfs_inc_ref(trans, new_root, buf);
177 btrfs_mark_buffer_dirty(cow);
182 int __btrfs_cow_block(struct btrfs_trans_handle *trans,
183 struct btrfs_root *root,
184 struct extent_buffer *buf,
185 struct extent_buffer *parent, int parent_slot,
186 struct extent_buffer **cow_ret,
187 u64 search_start, u64 empty_size)
190 struct extent_buffer *cow;
193 int different_trans = 0;
196 struct btrfs_key first_key;
201 WARN_ON(!btrfs_tree_locked(buf));
203 if (root->ref_cows) {
204 root_gen = trans->transid;
208 WARN_ON(root->ref_cows && trans->transid !=
209 root->fs_info->running_transaction->transid);
210 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
212 level = btrfs_header_level(buf);
213 nritems = btrfs_header_nritems(buf);
216 btrfs_item_key_to_cpu(buf, &first_key, 0);
218 btrfs_node_key_to_cpu(buf, &first_key, 0);
220 first_key.objectid = 0;
222 cow = btrfs_alloc_free_block(trans, root, buf->len,
223 root->root_key.objectid,
224 root_gen, first_key.objectid, level,
225 search_start, empty_size);
229 copy_extent_buffer(cow, buf, 0, 0, cow->len);
230 btrfs_set_header_bytenr(cow, cow->start);
231 btrfs_set_header_generation(cow, trans->transid);
232 btrfs_set_header_owner(cow, root->root_key.objectid);
233 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
235 WARN_ON(btrfs_header_generation(buf) > trans->transid);
236 if (btrfs_header_generation(buf) != trans->transid) {
238 ret = btrfs_inc_ref(trans, root, buf);
242 clean_tree_block(trans, root, buf);
245 if (buf == root->node) {
246 WARN_ON(parent && parent != buf);
247 root_gen = btrfs_header_generation(buf);
249 spin_lock(&root->node_lock);
251 extent_buffer_get(cow);
252 spin_unlock(&root->node_lock);
254 if (buf != root->commit_root) {
255 btrfs_free_extent(trans, root, buf->start,
256 buf->len, root->root_key.objectid,
259 free_extent_buffer(buf);
260 add_root_to_dirty_list(root);
262 root_gen = btrfs_header_generation(parent);
263 btrfs_set_node_blockptr(parent, parent_slot,
265 WARN_ON(trans->transid == 0);
266 btrfs_set_node_ptr_generation(parent, parent_slot,
268 btrfs_mark_buffer_dirty(parent);
269 WARN_ON(btrfs_header_generation(parent) != trans->transid);
270 btrfs_free_extent(trans, root, buf->start, buf->len,
271 btrfs_header_owner(parent), root_gen,
275 btrfs_tree_unlock(buf);
276 free_extent_buffer(buf);
277 btrfs_mark_buffer_dirty(cow);
282 int btrfs_cow_block(struct btrfs_trans_handle *trans,
283 struct btrfs_root *root, struct extent_buffer *buf,
284 struct extent_buffer *parent, int parent_slot,
285 struct extent_buffer **cow_ret)
291 if (trans->transaction != root->fs_info->running_transaction) {
292 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
293 root->fs_info->running_transaction->transid);
296 if (trans->transid != root->fs_info->generation) {
297 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
298 root->fs_info->generation);
302 header_trans = btrfs_header_generation(buf);
303 spin_lock(&root->fs_info->hash_lock);
304 if (header_trans == trans->transid &&
305 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
307 spin_unlock(&root->fs_info->hash_lock);
310 spin_unlock(&root->fs_info->hash_lock);
311 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
312 ret = __btrfs_cow_block(trans, root, buf, parent,
313 parent_slot, cow_ret, search_start, 0);
317 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
319 if (blocknr < other && other - (blocknr + blocksize) < 32768)
321 if (blocknr > other && blocknr - (other + blocksize) < 32768)
327 * compare two keys in a memcmp fashion
329 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
333 btrfs_disk_key_to_cpu(&k1, disk);
335 if (k1.objectid > k2->objectid)
337 if (k1.objectid < k2->objectid)
339 if (k1.type > k2->type)
341 if (k1.type < k2->type)
343 if (k1.offset > k2->offset)
345 if (k1.offset < k2->offset)
351 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
352 struct btrfs_root *root, struct extent_buffer *parent,
353 int start_slot, int cache_only, u64 *last_ret,
354 struct btrfs_key *progress)
356 struct extent_buffer *cur;
357 struct extent_buffer *tmp;
360 u64 search_start = *last_ret;
370 int progress_passed = 0;
371 struct btrfs_disk_key disk_key;
373 /* FIXME this code needs locking */
376 parent_level = btrfs_header_level(parent);
377 if (cache_only && parent_level != 1)
380 if (trans->transaction != root->fs_info->running_transaction) {
381 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
382 root->fs_info->running_transaction->transid);
385 if (trans->transid != root->fs_info->generation) {
386 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
387 root->fs_info->generation);
391 parent_nritems = btrfs_header_nritems(parent);
392 blocksize = btrfs_level_size(root, parent_level - 1);
393 end_slot = parent_nritems;
395 if (parent_nritems == 1)
398 for (i = start_slot; i < end_slot; i++) {
401 if (!parent->map_token) {
402 map_extent_buffer(parent,
403 btrfs_node_key_ptr_offset(i),
404 sizeof(struct btrfs_key_ptr),
405 &parent->map_token, &parent->kaddr,
406 &parent->map_start, &parent->map_len,
409 btrfs_node_key(parent, &disk_key, i);
410 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
414 blocknr = btrfs_node_blockptr(parent, i);
415 gen = btrfs_node_ptr_generation(parent, i);
417 last_block = blocknr;
420 other = btrfs_node_blockptr(parent, i - 1);
421 close = close_blocks(blocknr, other, blocksize);
423 if (!close && i < end_slot - 2) {
424 other = btrfs_node_blockptr(parent, i + 1);
425 close = close_blocks(blocknr, other, blocksize);
428 last_block = blocknr;
431 if (parent->map_token) {
432 unmap_extent_buffer(parent, parent->map_token,
434 parent->map_token = NULL;
437 cur = btrfs_find_tree_block(root, blocknr, blocksize);
439 uptodate = btrfs_buffer_uptodate(cur, gen);
442 if (!cur || !uptodate) {
444 free_extent_buffer(cur);
448 cur = read_tree_block(root, blocknr,
450 } else if (!uptodate) {
451 btrfs_read_buffer(cur, gen);
454 if (search_start == 0)
455 search_start = last_block;
457 err = __btrfs_cow_block(trans, root, cur, parent, i,
460 (end_slot - i) * blocksize));
462 free_extent_buffer(cur);
465 search_start = tmp->start;
466 last_block = tmp->start;
467 *last_ret = search_start;
468 if (parent_level == 1)
469 btrfs_clear_buffer_defrag(tmp);
470 free_extent_buffer(tmp);
472 if (parent->map_token) {
473 unmap_extent_buffer(parent, parent->map_token,
475 parent->map_token = NULL;
481 * The leaf data grows from end-to-front in the node.
482 * this returns the address of the start of the last item,
483 * which is the stop of the leaf data stack
485 static inline unsigned int leaf_data_end(struct btrfs_root *root,
486 struct extent_buffer *leaf)
488 u32 nr = btrfs_header_nritems(leaf);
490 return BTRFS_LEAF_DATA_SIZE(root);
491 return btrfs_item_offset_nr(leaf, nr - 1);
494 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
497 struct extent_buffer *parent = NULL;
498 struct extent_buffer *node = path->nodes[level];
499 struct btrfs_disk_key parent_key;
500 struct btrfs_disk_key node_key;
503 struct btrfs_key cpukey;
504 u32 nritems = btrfs_header_nritems(node);
506 if (path->nodes[level + 1])
507 parent = path->nodes[level + 1];
509 slot = path->slots[level];
510 BUG_ON(nritems == 0);
512 parent_slot = path->slots[level + 1];
513 btrfs_node_key(parent, &parent_key, parent_slot);
514 btrfs_node_key(node, &node_key, 0);
515 BUG_ON(memcmp(&parent_key, &node_key,
516 sizeof(struct btrfs_disk_key)));
517 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
518 btrfs_header_bytenr(node));
520 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
522 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
523 btrfs_node_key(node, &node_key, slot);
524 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
526 if (slot < nritems - 1) {
527 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
528 btrfs_node_key(node, &node_key, slot);
529 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
534 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
537 struct extent_buffer *leaf = path->nodes[level];
538 struct extent_buffer *parent = NULL;
540 struct btrfs_key cpukey;
541 struct btrfs_disk_key parent_key;
542 struct btrfs_disk_key leaf_key;
543 int slot = path->slots[0];
545 u32 nritems = btrfs_header_nritems(leaf);
547 if (path->nodes[level + 1])
548 parent = path->nodes[level + 1];
554 parent_slot = path->slots[level + 1];
555 btrfs_node_key(parent, &parent_key, parent_slot);
556 btrfs_item_key(leaf, &leaf_key, 0);
558 BUG_ON(memcmp(&parent_key, &leaf_key,
559 sizeof(struct btrfs_disk_key)));
560 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
561 btrfs_header_bytenr(leaf));
564 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
565 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
566 btrfs_item_key(leaf, &leaf_key, i);
567 if (comp_keys(&leaf_key, &cpukey) >= 0) {
568 btrfs_print_leaf(root, leaf);
569 printk("slot %d offset bad key\n", i);
572 if (btrfs_item_offset_nr(leaf, i) !=
573 btrfs_item_end_nr(leaf, i + 1)) {
574 btrfs_print_leaf(root, leaf);
575 printk("slot %d offset bad\n", i);
579 if (btrfs_item_offset_nr(leaf, i) +
580 btrfs_item_size_nr(leaf, i) !=
581 BTRFS_LEAF_DATA_SIZE(root)) {
582 btrfs_print_leaf(root, leaf);
583 printk("slot %d first offset bad\n", i);
589 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
590 btrfs_print_leaf(root, leaf);
591 printk("slot %d bad size \n", nritems - 1);
596 if (slot != 0 && slot < nritems - 1) {
597 btrfs_item_key(leaf, &leaf_key, slot);
598 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
599 if (comp_keys(&leaf_key, &cpukey) <= 0) {
600 btrfs_print_leaf(root, leaf);
601 printk("slot %d offset bad key\n", slot);
604 if (btrfs_item_offset_nr(leaf, slot - 1) !=
605 btrfs_item_end_nr(leaf, slot)) {
606 btrfs_print_leaf(root, leaf);
607 printk("slot %d offset bad\n", slot);
611 if (slot < nritems - 1) {
612 btrfs_item_key(leaf, &leaf_key, slot);
613 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
614 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
615 if (btrfs_item_offset_nr(leaf, slot) !=
616 btrfs_item_end_nr(leaf, slot + 1)) {
617 btrfs_print_leaf(root, leaf);
618 printk("slot %d offset bad\n", slot);
622 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
623 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
627 static int noinline check_block(struct btrfs_root *root,
628 struct btrfs_path *path, int level)
632 if (btrfs_header_level(path->nodes[level]) != level)
633 printk("warning: bad level %Lu wanted %d found %d\n",
634 path->nodes[level]->start, level,
635 btrfs_header_level(path->nodes[level]));
636 found_start = btrfs_header_bytenr(path->nodes[level]);
637 if (found_start != path->nodes[level]->start) {
638 printk("warning: bad bytentr %Lu found %Lu\n",
639 path->nodes[level]->start, found_start);
642 struct extent_buffer *buf = path->nodes[level];
644 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
645 (unsigned long)btrfs_header_fsid(buf),
647 printk("warning bad block %Lu\n", buf->start);
652 return check_leaf(root, path, level);
653 return check_node(root, path, level);
657 * search for key in the extent_buffer. The items start at offset p,
658 * and they are item_size apart. There are 'max' items in p.
660 * the slot in the array is returned via slot, and it points to
661 * the place where you would insert key if it is not found in
664 * slot may point to max if the key is bigger than all of the keys
666 static int generic_bin_search(struct extent_buffer *eb, unsigned long p,
667 int item_size, struct btrfs_key *key,
674 struct btrfs_disk_key *tmp = NULL;
675 struct btrfs_disk_key unaligned;
676 unsigned long offset;
677 char *map_token = NULL;
679 unsigned long map_start = 0;
680 unsigned long map_len = 0;
684 mid = (low + high) / 2;
685 offset = p + mid * item_size;
687 if (!map_token || offset < map_start ||
688 (offset + sizeof(struct btrfs_disk_key)) >
689 map_start + map_len) {
691 unmap_extent_buffer(eb, map_token, KM_USER0);
694 err = map_extent_buffer(eb, offset,
695 sizeof(struct btrfs_disk_key),
697 &map_start, &map_len, KM_USER0);
700 tmp = (struct btrfs_disk_key *)(kaddr + offset -
703 read_extent_buffer(eb, &unaligned,
704 offset, sizeof(unaligned));
709 tmp = (struct btrfs_disk_key *)(kaddr + offset -
712 ret = comp_keys(tmp, key);
721 unmap_extent_buffer(eb, map_token, KM_USER0);
727 unmap_extent_buffer(eb, map_token, KM_USER0);
732 * simple bin_search frontend that does the right thing for
735 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
736 int level, int *slot)
739 return generic_bin_search(eb,
740 offsetof(struct btrfs_leaf, items),
741 sizeof(struct btrfs_item),
742 key, btrfs_header_nritems(eb),
745 return generic_bin_search(eb,
746 offsetof(struct btrfs_node, ptrs),
747 sizeof(struct btrfs_key_ptr),
748 key, btrfs_header_nritems(eb),
754 static struct extent_buffer *read_node_slot(struct btrfs_root *root,
755 struct extent_buffer *parent, int slot)
757 int level = btrfs_header_level(parent);
760 if (slot >= btrfs_header_nritems(parent))
765 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
766 btrfs_level_size(root, level - 1),
767 btrfs_node_ptr_generation(parent, slot));
770 static int balance_level(struct btrfs_trans_handle *trans,
771 struct btrfs_root *root,
772 struct btrfs_path *path, int level)
774 struct extent_buffer *right = NULL;
775 struct extent_buffer *mid;
776 struct extent_buffer *left = NULL;
777 struct extent_buffer *parent = NULL;
781 int orig_slot = path->slots[level];
782 int err_on_enospc = 0;
788 mid = path->nodes[level];
789 WARN_ON(!path->locks[level]);
790 WARN_ON(btrfs_header_generation(mid) != trans->transid);
792 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
794 if (level < BTRFS_MAX_LEVEL - 1)
795 parent = path->nodes[level + 1];
796 pslot = path->slots[level + 1];
799 * deal with the case where there is only one pointer in the root
800 * by promoting the node below to a root
803 struct extent_buffer *child;
805 if (btrfs_header_nritems(mid) != 1)
808 /* promote the child to a root */
809 child = read_node_slot(root, mid, 0);
810 btrfs_tree_lock(child);
812 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
815 spin_lock(&root->node_lock);
817 spin_unlock(&root->node_lock);
819 add_root_to_dirty_list(root);
820 btrfs_tree_unlock(child);
821 path->locks[level] = 0;
822 path->nodes[level] = NULL;
823 clean_tree_block(trans, root, mid);
824 btrfs_tree_unlock(mid);
825 /* once for the path */
826 free_extent_buffer(mid);
827 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
828 root->root_key.objectid,
829 btrfs_header_generation(mid), 0, 0, 1);
830 /* once for the root ptr */
831 free_extent_buffer(mid);
834 if (btrfs_header_nritems(mid) >
835 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
838 if (btrfs_header_nritems(mid) < 2)
841 left = read_node_slot(root, parent, pslot - 1);
843 btrfs_tree_lock(left);
844 wret = btrfs_cow_block(trans, root, left,
845 parent, pslot - 1, &left);
851 right = read_node_slot(root, parent, pslot + 1);
853 btrfs_tree_lock(right);
854 wret = btrfs_cow_block(trans, root, right,
855 parent, pslot + 1, &right);
862 /* first, try to make some room in the middle buffer */
864 orig_slot += btrfs_header_nritems(left);
865 wret = push_node_left(trans, root, left, mid, 1);
868 if (btrfs_header_nritems(mid) < 2)
873 * then try to empty the right most buffer into the middle
876 wret = push_node_left(trans, root, mid, right, 1);
877 if (wret < 0 && wret != -ENOSPC)
879 if (btrfs_header_nritems(right) == 0) {
880 u64 bytenr = right->start;
881 u64 generation = btrfs_header_generation(parent);
882 u32 blocksize = right->len;
884 clean_tree_block(trans, root, right);
885 btrfs_tree_unlock(right);
886 free_extent_buffer(right);
888 wret = del_ptr(trans, root, path, level + 1, pslot +
892 wret = btrfs_free_extent(trans, root, bytenr,
894 btrfs_header_owner(parent),
895 generation, 0, 0, 1);
899 struct btrfs_disk_key right_key;
900 btrfs_node_key(right, &right_key, 0);
901 btrfs_set_node_key(parent, &right_key, pslot + 1);
902 btrfs_mark_buffer_dirty(parent);
905 if (btrfs_header_nritems(mid) == 1) {
907 * we're not allowed to leave a node with one item in the
908 * tree during a delete. A deletion from lower in the tree
909 * could try to delete the only pointer in this node.
910 * So, pull some keys from the left.
911 * There has to be a left pointer at this point because
912 * otherwise we would have pulled some pointers from the
916 wret = balance_node_right(trans, root, mid, left);
922 wret = push_node_left(trans, root, left, mid, 1);
928 if (btrfs_header_nritems(mid) == 0) {
929 /* we've managed to empty the middle node, drop it */
930 u64 root_gen = btrfs_header_generation(parent);
931 u64 bytenr = mid->start;
932 u32 blocksize = mid->len;
934 clean_tree_block(trans, root, mid);
935 btrfs_tree_unlock(mid);
936 free_extent_buffer(mid);
938 wret = del_ptr(trans, root, path, level + 1, pslot);
941 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
942 btrfs_header_owner(parent),
947 /* update the parent key to reflect our changes */
948 struct btrfs_disk_key mid_key;
949 btrfs_node_key(mid, &mid_key, 0);
950 btrfs_set_node_key(parent, &mid_key, pslot);
951 btrfs_mark_buffer_dirty(parent);
954 /* update the path */
956 if (btrfs_header_nritems(left) > orig_slot) {
957 extent_buffer_get(left);
958 /* left was locked after cow */
959 path->nodes[level] = left;
960 path->slots[level + 1] -= 1;
961 path->slots[level] = orig_slot;
963 btrfs_tree_unlock(mid);
964 free_extent_buffer(mid);
967 orig_slot -= btrfs_header_nritems(left);
968 path->slots[level] = orig_slot;
971 /* double check we haven't messed things up */
972 check_block(root, path, level);
974 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
978 btrfs_tree_unlock(right);
979 free_extent_buffer(right);
982 if (path->nodes[level] != left)
983 btrfs_tree_unlock(left);
984 free_extent_buffer(left);
989 /* returns zero if the push worked, non-zero otherwise */
990 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
991 struct btrfs_root *root,
992 struct btrfs_path *path, int level)
994 struct extent_buffer *right = NULL;
995 struct extent_buffer *mid;
996 struct extent_buffer *left = NULL;
997 struct extent_buffer *parent = NULL;
1001 int orig_slot = path->slots[level];
1007 mid = path->nodes[level];
1008 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1009 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1011 if (level < BTRFS_MAX_LEVEL - 1)
1012 parent = path->nodes[level + 1];
1013 pslot = path->slots[level + 1];
1018 left = read_node_slot(root, parent, pslot - 1);
1020 /* first, try to make some room in the middle buffer */
1024 btrfs_tree_lock(left);
1025 left_nr = btrfs_header_nritems(left);
1026 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1029 ret = btrfs_cow_block(trans, root, left, parent,
1034 wret = push_node_left(trans, root,
1041 struct btrfs_disk_key disk_key;
1042 orig_slot += left_nr;
1043 btrfs_node_key(mid, &disk_key, 0);
1044 btrfs_set_node_key(parent, &disk_key, pslot);
1045 btrfs_mark_buffer_dirty(parent);
1046 if (btrfs_header_nritems(left) > orig_slot) {
1047 path->nodes[level] = left;
1048 path->slots[level + 1] -= 1;
1049 path->slots[level] = orig_slot;
1050 btrfs_tree_unlock(mid);
1051 free_extent_buffer(mid);
1054 btrfs_header_nritems(left);
1055 path->slots[level] = orig_slot;
1056 btrfs_tree_unlock(left);
1057 free_extent_buffer(left);
1061 btrfs_tree_unlock(left);
1062 free_extent_buffer(left);
1064 right = read_node_slot(root, parent, pslot + 1);
1067 * then try to empty the right most buffer into the middle
1071 btrfs_tree_lock(right);
1072 right_nr = btrfs_header_nritems(right);
1073 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1076 ret = btrfs_cow_block(trans, root, right,
1082 wret = balance_node_right(trans, root,
1089 struct btrfs_disk_key disk_key;
1091 btrfs_node_key(right, &disk_key, 0);
1092 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1093 btrfs_mark_buffer_dirty(parent);
1095 if (btrfs_header_nritems(mid) <= orig_slot) {
1096 path->nodes[level] = right;
1097 path->slots[level + 1] += 1;
1098 path->slots[level] = orig_slot -
1099 btrfs_header_nritems(mid);
1100 btrfs_tree_unlock(mid);
1101 free_extent_buffer(mid);
1103 btrfs_tree_unlock(right);
1104 free_extent_buffer(right);
1108 btrfs_tree_unlock(right);
1109 free_extent_buffer(right);
1115 * readahead one full node of leaves
1117 static void reada_for_search(struct btrfs_root *root, struct btrfs_path *path,
1118 int level, int slot, u64 objectid)
1120 struct extent_buffer *node;
1121 struct btrfs_disk_key disk_key;
1127 int direction = path->reada;
1128 struct extent_buffer *eb;
1136 if (!path->nodes[level])
1139 node = path->nodes[level];
1141 search = btrfs_node_blockptr(node, slot);
1142 blocksize = btrfs_level_size(root, level - 1);
1143 eb = btrfs_find_tree_block(root, search, blocksize);
1145 free_extent_buffer(eb);
1149 highest_read = search;
1150 lowest_read = search;
1152 nritems = btrfs_header_nritems(node);
1155 if (direction < 0) {
1159 } else if (direction > 0) {
1164 if (path->reada < 0 && objectid) {
1165 btrfs_node_key(node, &disk_key, nr);
1166 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1169 search = btrfs_node_blockptr(node, nr);
1170 if ((search >= lowest_read && search <= highest_read) ||
1171 (search < lowest_read && lowest_read - search <= 32768) ||
1172 (search > highest_read && search - highest_read <= 32768)) {
1173 readahead_tree_block(root, search, blocksize,
1174 btrfs_node_ptr_generation(node, nr));
1178 if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32))
1180 if(nread > (1024 * 1024) || nscan > 128)
1183 if (search < lowest_read)
1184 lowest_read = search;
1185 if (search > highest_read)
1186 highest_read = search;
1190 static void unlock_up(struct btrfs_path *path, int level, int lowest_unlock)
1193 int skip_level = level;
1195 struct extent_buffer *t;
1197 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1198 if (!path->nodes[i])
1200 if (!path->locks[i])
1202 if (!no_skips && path->slots[i] == 0) {
1206 if (!no_skips && path->keep_locks) {
1209 nritems = btrfs_header_nritems(t);
1210 if (nritems < 1 || path->slots[i] >= nritems - 1) {
1215 if (skip_level < i && i >= lowest_unlock)
1219 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1220 btrfs_tree_unlock(t);
1227 * look for key in the tree. path is filled in with nodes along the way
1228 * if key is found, we return zero and you can find the item in the leaf
1229 * level of the path (level 0)
1231 * If the key isn't found, the path points to the slot where it should
1232 * be inserted, and 1 is returned. If there are other errors during the
1233 * search a negative error number is returned.
1235 * if ins_len > 0, nodes and leaves will be split as we walk down the
1236 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1239 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1240 *root, struct btrfs_key *key, struct btrfs_path *p, int
1243 struct extent_buffer *b;
1244 struct extent_buffer *tmp;
1248 int should_reada = p->reada;
1249 int lowest_unlock = 1;
1251 u8 lowest_level = 0;
1255 lowest_level = p->lowest_level;
1256 WARN_ON(lowest_level && ins_len);
1257 WARN_ON(p->nodes[0] != NULL);
1258 WARN_ON(cow && root == root->fs_info->extent_root &&
1259 !mutex_is_locked(&root->fs_info->alloc_mutex));
1260 WARN_ON(root == root->fs_info->chunk_root &&
1261 !mutex_is_locked(&root->fs_info->chunk_mutex));
1262 WARN_ON(root == root->fs_info->dev_root &&
1263 !mutex_is_locked(&root->fs_info->chunk_mutex));
1267 if (p->skip_locking)
1268 b = btrfs_root_node(root);
1270 b = btrfs_lock_root_node(root);
1273 level = btrfs_header_level(b);
1276 wret = btrfs_cow_block(trans, root, b,
1277 p->nodes[level + 1],
1278 p->slots[level + 1],
1281 free_extent_buffer(b);
1285 BUG_ON(!cow && ins_len);
1286 if (level != btrfs_header_level(b))
1288 level = btrfs_header_level(b);
1289 p->nodes[level] = b;
1290 if (!p->skip_locking)
1291 p->locks[level] = 1;
1292 ret = check_block(root, p, level);
1296 ret = bin_search(b, key, level, &slot);
1298 if (ret && slot > 0)
1300 p->slots[level] = slot;
1301 if (ins_len > 0 && btrfs_header_nritems(b) >=
1302 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1303 int sret = split_node(trans, root, p, level);
1307 b = p->nodes[level];
1308 slot = p->slots[level];
1309 } else if (ins_len < 0) {
1310 int sret = balance_level(trans, root, p,
1314 b = p->nodes[level];
1316 btrfs_release_path(NULL, p);
1319 slot = p->slots[level];
1320 BUG_ON(btrfs_header_nritems(b) == 1);
1322 /* this is only true while dropping a snapshot */
1323 if (level == lowest_level) {
1324 unlock_up(p, level, lowest_unlock);
1329 reada_for_search(root, p, level, slot,
1332 blocknr = btrfs_node_blockptr(b, slot);
1333 gen = btrfs_node_ptr_generation(b, slot);
1334 blocksize = btrfs_level_size(root, level - 1);
1336 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1337 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
1341 * reduce lock contention at high levels
1342 * of the btree by dropping locks before
1346 btrfs_release_path(NULL, p);
1348 free_extent_buffer(tmp);
1349 tmp = read_tree_block(root, blocknr,
1352 free_extent_buffer(tmp);
1355 b = read_node_slot(root, b, slot);
1358 if (!p->skip_locking)
1360 unlock_up(p, level, lowest_unlock);
1362 p->slots[level] = slot;
1363 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1364 sizeof(struct btrfs_item) + ins_len) {
1365 int sret = split_leaf(trans, root, key,
1366 p, ins_len, ret == 0);
1371 unlock_up(p, level, lowest_unlock);
1379 * adjust the pointers going up the tree, starting at level
1380 * making sure the right key of each node is points to 'key'.
1381 * This is used after shifting pointers to the left, so it stops
1382 * fixing up pointers when a given leaf/node is not in slot 0 of the
1385 * If this fails to write a tree block, it returns -1, but continues
1386 * fixing up the blocks in ram so the tree is consistent.
1388 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1389 struct btrfs_root *root, struct btrfs_path *path,
1390 struct btrfs_disk_key *key, int level)
1394 struct extent_buffer *t;
1396 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1397 int tslot = path->slots[i];
1398 if (!path->nodes[i])
1401 btrfs_set_node_key(t, key, tslot);
1402 btrfs_mark_buffer_dirty(path->nodes[i]);
1410 * try to push data from one node into the next node left in the
1413 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1414 * error, and > 0 if there was no room in the left hand block.
1416 static int push_node_left(struct btrfs_trans_handle *trans,
1417 struct btrfs_root *root, struct extent_buffer *dst,
1418 struct extent_buffer *src, int empty)
1425 src_nritems = btrfs_header_nritems(src);
1426 dst_nritems = btrfs_header_nritems(dst);
1427 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1428 WARN_ON(btrfs_header_generation(src) != trans->transid);
1429 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1431 if (!empty && src_nritems <= 8)
1434 if (push_items <= 0) {
1439 push_items = min(src_nritems, push_items);
1440 if (push_items < src_nritems) {
1441 /* leave at least 8 pointers in the node if
1442 * we aren't going to empty it
1444 if (src_nritems - push_items < 8) {
1445 if (push_items <= 8)
1451 push_items = min(src_nritems - 8, push_items);
1453 copy_extent_buffer(dst, src,
1454 btrfs_node_key_ptr_offset(dst_nritems),
1455 btrfs_node_key_ptr_offset(0),
1456 push_items * sizeof(struct btrfs_key_ptr));
1458 if (push_items < src_nritems) {
1459 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1460 btrfs_node_key_ptr_offset(push_items),
1461 (src_nritems - push_items) *
1462 sizeof(struct btrfs_key_ptr));
1464 btrfs_set_header_nritems(src, src_nritems - push_items);
1465 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1466 btrfs_mark_buffer_dirty(src);
1467 btrfs_mark_buffer_dirty(dst);
1472 * try to push data from one node into the next node right in the
1475 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1476 * error, and > 0 if there was no room in the right hand block.
1478 * this will only push up to 1/2 the contents of the left node over
1480 static int balance_node_right(struct btrfs_trans_handle *trans,
1481 struct btrfs_root *root,
1482 struct extent_buffer *dst,
1483 struct extent_buffer *src)
1491 WARN_ON(btrfs_header_generation(src) != trans->transid);
1492 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1494 src_nritems = btrfs_header_nritems(src);
1495 dst_nritems = btrfs_header_nritems(dst);
1496 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1497 if (push_items <= 0) {
1501 if (src_nritems < 4) {
1505 max_push = src_nritems / 2 + 1;
1506 /* don't try to empty the node */
1507 if (max_push >= src_nritems) {
1511 if (max_push < push_items)
1512 push_items = max_push;
1514 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1515 btrfs_node_key_ptr_offset(0),
1517 sizeof(struct btrfs_key_ptr));
1519 copy_extent_buffer(dst, src,
1520 btrfs_node_key_ptr_offset(0),
1521 btrfs_node_key_ptr_offset(src_nritems - push_items),
1522 push_items * sizeof(struct btrfs_key_ptr));
1524 btrfs_set_header_nritems(src, src_nritems - push_items);
1525 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1527 btrfs_mark_buffer_dirty(src);
1528 btrfs_mark_buffer_dirty(dst);
1533 * helper function to insert a new root level in the tree.
1534 * A new node is allocated, and a single item is inserted to
1535 * point to the existing root
1537 * returns zero on success or < 0 on failure.
1539 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1540 struct btrfs_root *root,
1541 struct btrfs_path *path, int level)
1545 struct extent_buffer *lower;
1546 struct extent_buffer *c;
1547 struct extent_buffer *old;
1548 struct btrfs_disk_key lower_key;
1550 BUG_ON(path->nodes[level]);
1551 BUG_ON(path->nodes[level-1] != root->node);
1554 root_gen = trans->transid;
1558 lower = path->nodes[level-1];
1560 btrfs_item_key(lower, &lower_key, 0);
1562 btrfs_node_key(lower, &lower_key, 0);
1564 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1565 root->root_key.objectid,
1566 root_gen, lower_key.objectid, level,
1567 root->node->start, 0);
1571 memset_extent_buffer(c, 0, 0, root->nodesize);
1572 btrfs_set_header_nritems(c, 1);
1573 btrfs_set_header_level(c, level);
1574 btrfs_set_header_bytenr(c, c->start);
1575 btrfs_set_header_generation(c, trans->transid);
1576 btrfs_set_header_owner(c, root->root_key.objectid);
1578 write_extent_buffer(c, root->fs_info->fsid,
1579 (unsigned long)btrfs_header_fsid(c),
1582 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1583 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1586 btrfs_set_node_key(c, &lower_key, 0);
1587 btrfs_set_node_blockptr(c, 0, lower->start);
1588 lower_gen = btrfs_header_generation(lower);
1589 WARN_ON(lower_gen == 0);
1591 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1593 btrfs_mark_buffer_dirty(c);
1595 spin_lock(&root->node_lock);
1598 spin_unlock(&root->node_lock);
1600 /* the super has an extra ref to root->node */
1601 free_extent_buffer(old);
1603 add_root_to_dirty_list(root);
1604 extent_buffer_get(c);
1605 path->nodes[level] = c;
1606 path->locks[level] = 1;
1607 path->slots[level] = 0;
1609 if (root->ref_cows && lower_gen != trans->transid) {
1610 struct btrfs_path *back_path = btrfs_alloc_path();
1612 mutex_lock(&root->fs_info->alloc_mutex);
1613 ret = btrfs_insert_extent_backref(trans,
1614 root->fs_info->extent_root,
1616 root->root_key.objectid,
1617 trans->transid, 0, 0);
1619 mutex_unlock(&root->fs_info->alloc_mutex);
1620 btrfs_free_path(back_path);
1626 * worker function to insert a single pointer in a node.
1627 * the node should have enough room for the pointer already
1629 * slot and level indicate where you want the key to go, and
1630 * blocknr is the block the key points to.
1632 * returns zero on success and < 0 on any error
1634 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1635 *root, struct btrfs_path *path, struct btrfs_disk_key
1636 *key, u64 bytenr, int slot, int level)
1638 struct extent_buffer *lower;
1641 BUG_ON(!path->nodes[level]);
1642 lower = path->nodes[level];
1643 nritems = btrfs_header_nritems(lower);
1646 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1648 if (slot != nritems) {
1649 memmove_extent_buffer(lower,
1650 btrfs_node_key_ptr_offset(slot + 1),
1651 btrfs_node_key_ptr_offset(slot),
1652 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1654 btrfs_set_node_key(lower, key, slot);
1655 btrfs_set_node_blockptr(lower, slot, bytenr);
1656 WARN_ON(trans->transid == 0);
1657 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1658 btrfs_set_header_nritems(lower, nritems + 1);
1659 btrfs_mark_buffer_dirty(lower);
1664 * split the node at the specified level in path in two.
1665 * The path is corrected to point to the appropriate node after the split
1667 * Before splitting this tries to make some room in the node by pushing
1668 * left and right, if either one works, it returns right away.
1670 * returns 0 on success and < 0 on failure
1672 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1673 *root, struct btrfs_path *path, int level)
1676 struct extent_buffer *c;
1677 struct extent_buffer *split;
1678 struct btrfs_disk_key disk_key;
1684 c = path->nodes[level];
1685 WARN_ON(btrfs_header_generation(c) != trans->transid);
1686 if (c == root->node) {
1687 /* trying to split the root, lets make a new one */
1688 ret = insert_new_root(trans, root, path, level + 1);
1692 ret = push_nodes_for_insert(trans, root, path, level);
1693 c = path->nodes[level];
1694 if (!ret && btrfs_header_nritems(c) <
1695 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1701 c_nritems = btrfs_header_nritems(c);
1703 root_gen = trans->transid;
1707 btrfs_node_key(c, &disk_key, 0);
1708 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1709 root->root_key.objectid,
1711 btrfs_disk_key_objectid(&disk_key),
1712 level, c->start, 0);
1714 return PTR_ERR(split);
1716 btrfs_set_header_flags(split, btrfs_header_flags(c));
1717 btrfs_set_header_level(split, btrfs_header_level(c));
1718 btrfs_set_header_bytenr(split, split->start);
1719 btrfs_set_header_generation(split, trans->transid);
1720 btrfs_set_header_owner(split, root->root_key.objectid);
1721 btrfs_set_header_flags(split, 0);
1722 write_extent_buffer(split, root->fs_info->fsid,
1723 (unsigned long)btrfs_header_fsid(split),
1725 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1726 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1729 mid = (c_nritems + 1) / 2;
1731 copy_extent_buffer(split, c,
1732 btrfs_node_key_ptr_offset(0),
1733 btrfs_node_key_ptr_offset(mid),
1734 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1735 btrfs_set_header_nritems(split, c_nritems - mid);
1736 btrfs_set_header_nritems(c, mid);
1739 btrfs_mark_buffer_dirty(c);
1740 btrfs_mark_buffer_dirty(split);
1742 btrfs_node_key(split, &disk_key, 0);
1743 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1744 path->slots[level + 1] + 1,
1749 if (path->slots[level] >= mid) {
1750 path->slots[level] -= mid;
1751 btrfs_tree_unlock(c);
1752 free_extent_buffer(c);
1753 path->nodes[level] = split;
1754 path->slots[level + 1] += 1;
1756 btrfs_tree_unlock(split);
1757 free_extent_buffer(split);
1763 * how many bytes are required to store the items in a leaf. start
1764 * and nr indicate which items in the leaf to check. This totals up the
1765 * space used both by the item structs and the item data
1767 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1770 int nritems = btrfs_header_nritems(l);
1771 int end = min(nritems, start + nr) - 1;
1775 data_len = btrfs_item_end_nr(l, start);
1776 data_len = data_len - btrfs_item_offset_nr(l, end);
1777 data_len += sizeof(struct btrfs_item) * nr;
1778 WARN_ON(data_len < 0);
1783 * The space between the end of the leaf items and
1784 * the start of the leaf data. IOW, how much room
1785 * the leaf has left for both items and data
1787 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1789 int nritems = btrfs_header_nritems(leaf);
1791 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1793 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1794 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1795 leaf_space_used(leaf, 0, nritems), nritems);
1801 * push some data in the path leaf to the right, trying to free up at
1802 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1804 * returns 1 if the push failed because the other node didn't have enough
1805 * room, 0 if everything worked out and < 0 if there were major errors.
1807 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1808 *root, struct btrfs_path *path, int data_size,
1811 struct extent_buffer *left = path->nodes[0];
1812 struct extent_buffer *right;
1813 struct extent_buffer *upper;
1814 struct btrfs_disk_key disk_key;
1820 struct btrfs_item *item;
1828 slot = path->slots[1];
1829 if (!path->nodes[1]) {
1832 upper = path->nodes[1];
1833 if (slot >= btrfs_header_nritems(upper) - 1)
1836 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
1838 right = read_node_slot(root, upper, slot + 1);
1839 btrfs_tree_lock(right);
1840 free_space = btrfs_leaf_free_space(root, right);
1841 if (free_space < data_size + sizeof(struct btrfs_item))
1844 /* cow and double check */
1845 ret = btrfs_cow_block(trans, root, right, upper,
1850 free_space = btrfs_leaf_free_space(root, right);
1851 if (free_space < data_size + sizeof(struct btrfs_item))
1854 left_nritems = btrfs_header_nritems(left);
1855 if (left_nritems == 0)
1863 i = left_nritems - 1;
1865 item = btrfs_item_nr(left, i);
1867 if (path->slots[0] == i)
1868 push_space += data_size + sizeof(*item);
1870 if (!left->map_token) {
1871 map_extent_buffer(left, (unsigned long)item,
1872 sizeof(struct btrfs_item),
1873 &left->map_token, &left->kaddr,
1874 &left->map_start, &left->map_len,
1878 this_item_size = btrfs_item_size(left, item);
1879 if (this_item_size + sizeof(*item) + push_space > free_space)
1882 push_space += this_item_size + sizeof(*item);
1887 if (left->map_token) {
1888 unmap_extent_buffer(left, left->map_token, KM_USER1);
1889 left->map_token = NULL;
1892 if (push_items == 0)
1895 if (!empty && push_items == left_nritems)
1898 /* push left to right */
1899 right_nritems = btrfs_header_nritems(right);
1901 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1902 push_space -= leaf_data_end(root, left);
1904 /* make room in the right data area */
1905 data_end = leaf_data_end(root, right);
1906 memmove_extent_buffer(right,
1907 btrfs_leaf_data(right) + data_end - push_space,
1908 btrfs_leaf_data(right) + data_end,
1909 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1911 /* copy from the left data area */
1912 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1913 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1914 btrfs_leaf_data(left) + leaf_data_end(root, left),
1917 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1918 btrfs_item_nr_offset(0),
1919 right_nritems * sizeof(struct btrfs_item));
1921 /* copy the items from left to right */
1922 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1923 btrfs_item_nr_offset(left_nritems - push_items),
1924 push_items * sizeof(struct btrfs_item));
1926 /* update the item pointers */
1927 right_nritems += push_items;
1928 btrfs_set_header_nritems(right, right_nritems);
1929 push_space = BTRFS_LEAF_DATA_SIZE(root);
1930 for (i = 0; i < right_nritems; i++) {
1931 item = btrfs_item_nr(right, i);
1932 if (!right->map_token) {
1933 map_extent_buffer(right, (unsigned long)item,
1934 sizeof(struct btrfs_item),
1935 &right->map_token, &right->kaddr,
1936 &right->map_start, &right->map_len,
1939 push_space -= btrfs_item_size(right, item);
1940 btrfs_set_item_offset(right, item, push_space);
1943 if (right->map_token) {
1944 unmap_extent_buffer(right, right->map_token, KM_USER1);
1945 right->map_token = NULL;
1947 left_nritems -= push_items;
1948 btrfs_set_header_nritems(left, left_nritems);
1951 btrfs_mark_buffer_dirty(left);
1952 btrfs_mark_buffer_dirty(right);
1954 btrfs_item_key(right, &disk_key, 0);
1955 btrfs_set_node_key(upper, &disk_key, slot + 1);
1956 btrfs_mark_buffer_dirty(upper);
1958 /* then fixup the leaf pointer in the path */
1959 if (path->slots[0] >= left_nritems) {
1960 path->slots[0] -= left_nritems;
1961 if (btrfs_header_nritems(path->nodes[0]) == 0)
1962 clean_tree_block(trans, root, path->nodes[0]);
1963 btrfs_tree_unlock(path->nodes[0]);
1964 free_extent_buffer(path->nodes[0]);
1965 path->nodes[0] = right;
1966 path->slots[1] += 1;
1968 btrfs_tree_unlock(right);
1969 free_extent_buffer(right);
1974 btrfs_tree_unlock(right);
1975 free_extent_buffer(right);
1980 * push some data in the path leaf to the left, trying to free up at
1981 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1983 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1984 *root, struct btrfs_path *path, int data_size,
1987 struct btrfs_disk_key disk_key;
1988 struct extent_buffer *right = path->nodes[0];
1989 struct extent_buffer *left;
1995 struct btrfs_item *item;
1996 u32 old_left_nritems;
2002 u32 old_left_item_size;
2004 slot = path->slots[1];
2007 if (!path->nodes[1])
2010 right_nritems = btrfs_header_nritems(right);
2011 if (right_nritems == 0) {
2015 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
2017 left = read_node_slot(root, path->nodes[1], slot - 1);
2018 btrfs_tree_lock(left);
2019 free_space = btrfs_leaf_free_space(root, left);
2020 if (free_space < data_size + sizeof(struct btrfs_item)) {
2025 /* cow and double check */
2026 ret = btrfs_cow_block(trans, root, left,
2027 path->nodes[1], slot - 1, &left);
2029 /* we hit -ENOSPC, but it isn't fatal here */
2034 free_space = btrfs_leaf_free_space(root, left);
2035 if (free_space < data_size + sizeof(struct btrfs_item)) {
2043 nr = right_nritems - 1;
2045 for (i = 0; i < nr; i++) {
2046 item = btrfs_item_nr(right, i);
2047 if (!right->map_token) {
2048 map_extent_buffer(right, (unsigned long)item,
2049 sizeof(struct btrfs_item),
2050 &right->map_token, &right->kaddr,
2051 &right->map_start, &right->map_len,
2055 if (path->slots[0] == i)
2056 push_space += data_size + sizeof(*item);
2058 this_item_size = btrfs_item_size(right, item);
2059 if (this_item_size + sizeof(*item) + push_space > free_space)
2063 push_space += this_item_size + sizeof(*item);
2066 if (right->map_token) {
2067 unmap_extent_buffer(right, right->map_token, KM_USER1);
2068 right->map_token = NULL;
2071 if (push_items == 0) {
2075 if (!empty && push_items == btrfs_header_nritems(right))
2078 /* push data from right to left */
2079 copy_extent_buffer(left, right,
2080 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2081 btrfs_item_nr_offset(0),
2082 push_items * sizeof(struct btrfs_item));
2084 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2085 btrfs_item_offset_nr(right, push_items -1);
2087 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2088 leaf_data_end(root, left) - push_space,
2089 btrfs_leaf_data(right) +
2090 btrfs_item_offset_nr(right, push_items - 1),
2092 old_left_nritems = btrfs_header_nritems(left);
2093 BUG_ON(old_left_nritems < 0);
2095 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2096 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2099 item = btrfs_item_nr(left, i);
2100 if (!left->map_token) {
2101 map_extent_buffer(left, (unsigned long)item,
2102 sizeof(struct btrfs_item),
2103 &left->map_token, &left->kaddr,
2104 &left->map_start, &left->map_len,
2108 ioff = btrfs_item_offset(left, item);
2109 btrfs_set_item_offset(left, item,
2110 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2112 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2113 if (left->map_token) {
2114 unmap_extent_buffer(left, left->map_token, KM_USER1);
2115 left->map_token = NULL;
2118 /* fixup right node */
2119 if (push_items > right_nritems) {
2120 printk("push items %d nr %u\n", push_items, right_nritems);
2124 if (push_items < right_nritems) {
2125 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2126 leaf_data_end(root, right);
2127 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2128 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2129 btrfs_leaf_data(right) +
2130 leaf_data_end(root, right), push_space);
2132 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2133 btrfs_item_nr_offset(push_items),
2134 (btrfs_header_nritems(right) - push_items) *
2135 sizeof(struct btrfs_item));
2137 right_nritems -= push_items;
2138 btrfs_set_header_nritems(right, right_nritems);
2139 push_space = BTRFS_LEAF_DATA_SIZE(root);
2140 for (i = 0; i < right_nritems; i++) {
2141 item = btrfs_item_nr(right, i);
2143 if (!right->map_token) {
2144 map_extent_buffer(right, (unsigned long)item,
2145 sizeof(struct btrfs_item),
2146 &right->map_token, &right->kaddr,
2147 &right->map_start, &right->map_len,
2151 push_space = push_space - btrfs_item_size(right, item);
2152 btrfs_set_item_offset(right, item, push_space);
2154 if (right->map_token) {
2155 unmap_extent_buffer(right, right->map_token, KM_USER1);
2156 right->map_token = NULL;
2159 btrfs_mark_buffer_dirty(left);
2161 btrfs_mark_buffer_dirty(right);
2163 btrfs_item_key(right, &disk_key, 0);
2164 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2168 /* then fixup the leaf pointer in the path */
2169 if (path->slots[0] < push_items) {
2170 path->slots[0] += old_left_nritems;
2171 if (btrfs_header_nritems(path->nodes[0]) == 0)
2172 clean_tree_block(trans, root, path->nodes[0]);
2173 btrfs_tree_unlock(path->nodes[0]);
2174 free_extent_buffer(path->nodes[0]);
2175 path->nodes[0] = left;
2176 path->slots[1] -= 1;
2178 btrfs_tree_unlock(left);
2179 free_extent_buffer(left);
2180 path->slots[0] -= push_items;
2182 BUG_ON(path->slots[0] < 0);
2185 btrfs_tree_unlock(left);
2186 free_extent_buffer(left);
2191 * split the path's leaf in two, making sure there is at least data_size
2192 * available for the resulting leaf level of the path.
2194 * returns 0 if all went well and < 0 on failure.
2196 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
2197 *root, struct btrfs_key *ins_key,
2198 struct btrfs_path *path, int data_size, int extend)
2201 struct extent_buffer *l;
2205 struct extent_buffer *right;
2206 int space_needed = data_size + sizeof(struct btrfs_item);
2213 int num_doubles = 0;
2214 struct btrfs_disk_key disk_key;
2217 space_needed = data_size;
2220 root_gen = trans->transid;
2224 /* first try to make some room by pushing left and right */
2225 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
2226 wret = push_leaf_right(trans, root, path, data_size, 0);
2231 wret = push_leaf_left(trans, root, path, data_size, 0);
2237 /* did the pushes work? */
2238 if (btrfs_leaf_free_space(root, l) >= space_needed)
2242 if (!path->nodes[1]) {
2243 ret = insert_new_root(trans, root, path, 1);
2250 slot = path->slots[0];
2251 nritems = btrfs_header_nritems(l);
2252 mid = (nritems + 1)/ 2;
2254 btrfs_item_key(l, &disk_key, 0);
2256 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2257 root->root_key.objectid,
2258 root_gen, disk_key.objectid, 0,
2260 if (IS_ERR(right)) {
2262 return PTR_ERR(right);
2265 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2266 btrfs_set_header_bytenr(right, right->start);
2267 btrfs_set_header_generation(right, trans->transid);
2268 btrfs_set_header_owner(right, root->root_key.objectid);
2269 btrfs_set_header_level(right, 0);
2270 write_extent_buffer(right, root->fs_info->fsid,
2271 (unsigned long)btrfs_header_fsid(right),
2274 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2275 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2279 leaf_space_used(l, mid, nritems - mid) + space_needed >
2280 BTRFS_LEAF_DATA_SIZE(root)) {
2281 if (slot >= nritems) {
2282 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2283 btrfs_set_header_nritems(right, 0);
2284 wret = insert_ptr(trans, root, path,
2285 &disk_key, right->start,
2286 path->slots[1] + 1, 1);
2290 btrfs_tree_unlock(path->nodes[0]);
2291 free_extent_buffer(path->nodes[0]);
2292 path->nodes[0] = right;
2294 path->slots[1] += 1;
2295 btrfs_mark_buffer_dirty(right);
2299 if (mid != nritems &&
2300 leaf_space_used(l, mid, nritems - mid) +
2301 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2306 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2307 BTRFS_LEAF_DATA_SIZE(root)) {
2308 if (!extend && slot == 0) {
2309 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2310 btrfs_set_header_nritems(right, 0);
2311 wret = insert_ptr(trans, root, path,
2317 btrfs_tree_unlock(path->nodes[0]);
2318 free_extent_buffer(path->nodes[0]);
2319 path->nodes[0] = right;
2321 if (path->slots[1] == 0) {
2322 wret = fixup_low_keys(trans, root,
2323 path, &disk_key, 1);
2327 btrfs_mark_buffer_dirty(right);
2329 } else if (extend && slot == 0) {
2333 if (mid != nritems &&
2334 leaf_space_used(l, mid, nritems - mid) +
2335 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2341 nritems = nritems - mid;
2342 btrfs_set_header_nritems(right, nritems);
2343 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2345 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2346 btrfs_item_nr_offset(mid),
2347 nritems * sizeof(struct btrfs_item));
2349 copy_extent_buffer(right, l,
2350 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2351 data_copy_size, btrfs_leaf_data(l) +
2352 leaf_data_end(root, l), data_copy_size);
2354 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2355 btrfs_item_end_nr(l, mid);
2357 for (i = 0; i < nritems; i++) {
2358 struct btrfs_item *item = btrfs_item_nr(right, i);
2361 if (!right->map_token) {
2362 map_extent_buffer(right, (unsigned long)item,
2363 sizeof(struct btrfs_item),
2364 &right->map_token, &right->kaddr,
2365 &right->map_start, &right->map_len,
2369 ioff = btrfs_item_offset(right, item);
2370 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2373 if (right->map_token) {
2374 unmap_extent_buffer(right, right->map_token, KM_USER1);
2375 right->map_token = NULL;
2378 btrfs_set_header_nritems(l, mid);
2380 btrfs_item_key(right, &disk_key, 0);
2381 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2382 path->slots[1] + 1, 1);
2386 btrfs_mark_buffer_dirty(right);
2387 btrfs_mark_buffer_dirty(l);
2388 BUG_ON(path->slots[0] != slot);
2391 btrfs_tree_unlock(path->nodes[0]);
2392 free_extent_buffer(path->nodes[0]);
2393 path->nodes[0] = right;
2394 path->slots[0] -= mid;
2395 path->slots[1] += 1;
2397 btrfs_tree_unlock(right);
2398 free_extent_buffer(right);
2401 BUG_ON(path->slots[0] < 0);
2404 BUG_ON(num_doubles != 0);
2411 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2412 struct btrfs_root *root,
2413 struct btrfs_path *path,
2414 u32 new_size, int from_end)
2419 struct extent_buffer *leaf;
2420 struct btrfs_item *item;
2422 unsigned int data_end;
2423 unsigned int old_data_start;
2424 unsigned int old_size;
2425 unsigned int size_diff;
2428 slot_orig = path->slots[0];
2429 leaf = path->nodes[0];
2430 slot = path->slots[0];
2432 old_size = btrfs_item_size_nr(leaf, slot);
2433 if (old_size == new_size)
2436 nritems = btrfs_header_nritems(leaf);
2437 data_end = leaf_data_end(root, leaf);
2439 old_data_start = btrfs_item_offset_nr(leaf, slot);
2441 size_diff = old_size - new_size;
2444 BUG_ON(slot >= nritems);
2447 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2449 /* first correct the data pointers */
2450 for (i = slot; i < nritems; i++) {
2452 item = btrfs_item_nr(leaf, i);
2454 if (!leaf->map_token) {
2455 map_extent_buffer(leaf, (unsigned long)item,
2456 sizeof(struct btrfs_item),
2457 &leaf->map_token, &leaf->kaddr,
2458 &leaf->map_start, &leaf->map_len,
2462 ioff = btrfs_item_offset(leaf, item);
2463 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2466 if (leaf->map_token) {
2467 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2468 leaf->map_token = NULL;
2471 /* shift the data */
2473 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2474 data_end + size_diff, btrfs_leaf_data(leaf) +
2475 data_end, old_data_start + new_size - data_end);
2477 struct btrfs_disk_key disk_key;
2480 btrfs_item_key(leaf, &disk_key, slot);
2482 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2484 struct btrfs_file_extent_item *fi;
2486 fi = btrfs_item_ptr(leaf, slot,
2487 struct btrfs_file_extent_item);
2488 fi = (struct btrfs_file_extent_item *)(
2489 (unsigned long)fi - size_diff);
2491 if (btrfs_file_extent_type(leaf, fi) ==
2492 BTRFS_FILE_EXTENT_INLINE) {
2493 ptr = btrfs_item_ptr_offset(leaf, slot);
2494 memmove_extent_buffer(leaf, ptr,
2496 offsetof(struct btrfs_file_extent_item,
2501 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2502 data_end + size_diff, btrfs_leaf_data(leaf) +
2503 data_end, old_data_start - data_end);
2505 offset = btrfs_disk_key_offset(&disk_key);
2506 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2507 btrfs_set_item_key(leaf, &disk_key, slot);
2509 fixup_low_keys(trans, root, path, &disk_key, 1);
2512 item = btrfs_item_nr(leaf, slot);
2513 btrfs_set_item_size(leaf, item, new_size);
2514 btrfs_mark_buffer_dirty(leaf);
2517 if (btrfs_leaf_free_space(root, leaf) < 0) {
2518 btrfs_print_leaf(root, leaf);
2524 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2525 struct btrfs_root *root, struct btrfs_path *path,
2531 struct extent_buffer *leaf;
2532 struct btrfs_item *item;
2534 unsigned int data_end;
2535 unsigned int old_data;
2536 unsigned int old_size;
2539 slot_orig = path->slots[0];
2540 leaf = path->nodes[0];
2542 nritems = btrfs_header_nritems(leaf);
2543 data_end = leaf_data_end(root, leaf);
2545 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2546 btrfs_print_leaf(root, leaf);
2549 slot = path->slots[0];
2550 old_data = btrfs_item_end_nr(leaf, slot);
2553 if (slot >= nritems) {
2554 btrfs_print_leaf(root, leaf);
2555 printk("slot %d too large, nritems %d\n", slot, nritems);
2560 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2562 /* first correct the data pointers */
2563 for (i = slot; i < nritems; i++) {
2565 item = btrfs_item_nr(leaf, i);
2567 if (!leaf->map_token) {
2568 map_extent_buffer(leaf, (unsigned long)item,
2569 sizeof(struct btrfs_item),
2570 &leaf->map_token, &leaf->kaddr,
2571 &leaf->map_start, &leaf->map_len,
2574 ioff = btrfs_item_offset(leaf, item);
2575 btrfs_set_item_offset(leaf, item, ioff - data_size);
2578 if (leaf->map_token) {
2579 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2580 leaf->map_token = NULL;
2583 /* shift the data */
2584 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2585 data_end - data_size, btrfs_leaf_data(leaf) +
2586 data_end, old_data - data_end);
2588 data_end = old_data;
2589 old_size = btrfs_item_size_nr(leaf, slot);
2590 item = btrfs_item_nr(leaf, slot);
2591 btrfs_set_item_size(leaf, item, old_size + data_size);
2592 btrfs_mark_buffer_dirty(leaf);
2595 if (btrfs_leaf_free_space(root, leaf) < 0) {
2596 btrfs_print_leaf(root, leaf);
2603 * Given a key and some data, insert an item into the tree.
2604 * This does all the path init required, making room in the tree if needed.
2606 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2607 struct btrfs_root *root,
2608 struct btrfs_path *path,
2609 struct btrfs_key *cpu_key, u32 *data_size,
2612 struct extent_buffer *leaf;
2613 struct btrfs_item *item;
2621 unsigned int data_end;
2622 struct btrfs_disk_key disk_key;
2624 for (i = 0; i < nr; i++) {
2625 total_data += data_size[i];
2628 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2629 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2636 slot_orig = path->slots[0];
2637 leaf = path->nodes[0];
2639 nritems = btrfs_header_nritems(leaf);
2640 data_end = leaf_data_end(root, leaf);
2642 if (btrfs_leaf_free_space(root, leaf) <
2643 sizeof(struct btrfs_item) + total_size) {
2644 btrfs_print_leaf(root, leaf);
2645 printk("not enough freespace need %u have %d\n",
2646 total_size, btrfs_leaf_free_space(root, leaf));
2650 slot = path->slots[0];
2653 if (slot != nritems) {
2655 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2657 if (old_data < data_end) {
2658 btrfs_print_leaf(root, leaf);
2659 printk("slot %d old_data %d data_end %d\n",
2660 slot, old_data, data_end);
2664 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2666 /* first correct the data pointers */
2667 WARN_ON(leaf->map_token);
2668 for (i = slot; i < nritems; i++) {
2671 item = btrfs_item_nr(leaf, i);
2672 if (!leaf->map_token) {
2673 map_extent_buffer(leaf, (unsigned long)item,
2674 sizeof(struct btrfs_item),
2675 &leaf->map_token, &leaf->kaddr,
2676 &leaf->map_start, &leaf->map_len,
2680 ioff = btrfs_item_offset(leaf, item);
2681 btrfs_set_item_offset(leaf, item, ioff - total_data);
2683 if (leaf->map_token) {
2684 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2685 leaf->map_token = NULL;
2688 /* shift the items */
2689 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2690 btrfs_item_nr_offset(slot),
2691 (nritems - slot) * sizeof(struct btrfs_item));
2693 /* shift the data */
2694 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2695 data_end - total_data, btrfs_leaf_data(leaf) +
2696 data_end, old_data - data_end);
2697 data_end = old_data;
2700 /* setup the item for the new data */
2701 for (i = 0; i < nr; i++) {
2702 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2703 btrfs_set_item_key(leaf, &disk_key, slot + i);
2704 item = btrfs_item_nr(leaf, slot + i);
2705 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2706 data_end -= data_size[i];
2707 btrfs_set_item_size(leaf, item, data_size[i]);
2709 btrfs_set_header_nritems(leaf, nritems + nr);
2710 btrfs_mark_buffer_dirty(leaf);
2714 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2715 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2718 if (btrfs_leaf_free_space(root, leaf) < 0) {
2719 btrfs_print_leaf(root, leaf);
2727 * Given a key and some data, insert an item into the tree.
2728 * This does all the path init required, making room in the tree if needed.
2730 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2731 *root, struct btrfs_key *cpu_key, void *data, u32
2735 struct btrfs_path *path;
2736 struct extent_buffer *leaf;
2739 path = btrfs_alloc_path();
2741 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2743 leaf = path->nodes[0];
2744 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2745 write_extent_buffer(leaf, data, ptr, data_size);
2746 btrfs_mark_buffer_dirty(leaf);
2748 btrfs_free_path(path);
2753 * delete the pointer from a given node.
2755 * If the delete empties a node, the node is removed from the tree,
2756 * continuing all the way the root if required. The root is converted into
2757 * a leaf if all the nodes are emptied.
2759 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2760 struct btrfs_path *path, int level, int slot)
2762 struct extent_buffer *parent = path->nodes[level];
2767 nritems = btrfs_header_nritems(parent);
2768 if (slot != nritems -1) {
2769 memmove_extent_buffer(parent,
2770 btrfs_node_key_ptr_offset(slot),
2771 btrfs_node_key_ptr_offset(slot + 1),
2772 sizeof(struct btrfs_key_ptr) *
2773 (nritems - slot - 1));
2776 btrfs_set_header_nritems(parent, nritems);
2777 if (nritems == 0 && parent == root->node) {
2778 BUG_ON(btrfs_header_level(root->node) != 1);
2779 /* just turn the root into a leaf and break */
2780 btrfs_set_header_level(root->node, 0);
2781 } else if (slot == 0) {
2782 struct btrfs_disk_key disk_key;
2784 btrfs_node_key(parent, &disk_key, 0);
2785 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2789 btrfs_mark_buffer_dirty(parent);
2794 * delete the item at the leaf level in path. If that empties
2795 * the leaf, remove it from the tree
2797 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2798 struct btrfs_path *path, int slot, int nr)
2800 struct extent_buffer *leaf;
2801 struct btrfs_item *item;
2809 leaf = path->nodes[0];
2810 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2812 for (i = 0; i < nr; i++)
2813 dsize += btrfs_item_size_nr(leaf, slot + i);
2815 nritems = btrfs_header_nritems(leaf);
2817 if (slot + nr != nritems) {
2819 int data_end = leaf_data_end(root, leaf);
2821 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2823 btrfs_leaf_data(leaf) + data_end,
2824 last_off - data_end);
2826 for (i = slot + nr; i < nritems; i++) {
2829 item = btrfs_item_nr(leaf, i);
2830 if (!leaf->map_token) {
2831 map_extent_buffer(leaf, (unsigned long)item,
2832 sizeof(struct btrfs_item),
2833 &leaf->map_token, &leaf->kaddr,
2834 &leaf->map_start, &leaf->map_len,
2837 ioff = btrfs_item_offset(leaf, item);
2838 btrfs_set_item_offset(leaf, item, ioff + dsize);
2841 if (leaf->map_token) {
2842 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2843 leaf->map_token = NULL;
2846 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2847 btrfs_item_nr_offset(slot + nr),
2848 sizeof(struct btrfs_item) *
2849 (nritems - slot - nr));
2851 btrfs_set_header_nritems(leaf, nritems - nr);
2854 /* delete the leaf if we've emptied it */
2856 if (leaf == root->node) {
2857 btrfs_set_header_level(leaf, 0);
2859 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2860 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2863 wret = btrfs_free_extent(trans, root,
2864 leaf->start, leaf->len,
2865 btrfs_header_owner(path->nodes[1]),
2871 int used = leaf_space_used(leaf, 0, nritems);
2873 struct btrfs_disk_key disk_key;
2875 btrfs_item_key(leaf, &disk_key, 0);
2876 wret = fixup_low_keys(trans, root, path,
2882 /* delete the leaf if it is mostly empty */
2883 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2884 /* push_leaf_left fixes the path.
2885 * make sure the path still points to our leaf
2886 * for possible call to del_ptr below
2888 slot = path->slots[1];
2889 extent_buffer_get(leaf);
2891 wret = push_leaf_left(trans, root, path, 1, 1);
2892 if (wret < 0 && wret != -ENOSPC)
2895 if (path->nodes[0] == leaf &&
2896 btrfs_header_nritems(leaf)) {
2897 wret = push_leaf_right(trans, root, path, 1, 1);
2898 if (wret < 0 && wret != -ENOSPC)
2902 if (btrfs_header_nritems(leaf) == 0) {
2904 u64 bytenr = leaf->start;
2905 u32 blocksize = leaf->len;
2907 root_gen = btrfs_header_generation(
2910 wret = del_ptr(trans, root, path, 1, slot);
2914 free_extent_buffer(leaf);
2915 wret = btrfs_free_extent(trans, root, bytenr,
2917 btrfs_header_owner(path->nodes[1]),
2922 /* if we're still in the path, make sure
2923 * we're dirty. Otherwise, one of the
2924 * push_leaf functions must have already
2925 * dirtied this buffer
2927 if (path->nodes[0] == leaf)
2928 btrfs_mark_buffer_dirty(leaf);
2929 free_extent_buffer(leaf);
2932 btrfs_mark_buffer_dirty(leaf);
2939 * search the tree again to find a leaf with lesser keys
2940 * returns 0 if it found something or 1 if there are no lesser leaves.
2941 * returns < 0 on io errors.
2943 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2945 struct btrfs_key key;
2946 struct btrfs_disk_key found_key;
2949 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
2953 else if (key.type > 0)
2955 else if (key.objectid > 0)
2960 btrfs_release_path(root, path);
2961 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2964 btrfs_item_key(path->nodes[0], &found_key, 0);
2965 ret = comp_keys(&found_key, &key);
2972 * search the tree again to find a leaf with greater keys
2973 * returns 0 if it found something or 1 if there are no greater leaves.
2974 * returns < 0 on io errors.
2976 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2980 struct extent_buffer *c;
2981 struct extent_buffer *next = NULL;
2982 struct btrfs_key key;
2986 nritems = btrfs_header_nritems(path->nodes[0]);
2991 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
2993 btrfs_release_path(root, path);
2994 path->keep_locks = 1;
2995 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2996 path->keep_locks = 0;
3001 nritems = btrfs_header_nritems(path->nodes[0]);
3003 * by releasing the path above we dropped all our locks. A balance
3004 * could have added more items next to the key that used to be
3005 * at the very end of the block. So, check again here and
3006 * advance the path if there are now more items available.
3008 if (nritems > 0 && path->slots[0] < nritems - 1) {
3013 while(level < BTRFS_MAX_LEVEL) {
3014 if (!path->nodes[level])
3017 slot = path->slots[level] + 1;
3018 c = path->nodes[level];
3019 if (slot >= btrfs_header_nritems(c)) {
3021 if (level == BTRFS_MAX_LEVEL) {
3028 btrfs_tree_unlock(next);
3029 free_extent_buffer(next);
3032 if (level == 1 && path->locks[1] && path->reada)
3033 reada_for_search(root, path, level, slot, 0);
3035 next = read_node_slot(root, c, slot);
3036 if (!path->skip_locking) {
3037 WARN_ON(!btrfs_tree_locked(c));
3038 btrfs_tree_lock(next);
3042 path->slots[level] = slot;
3045 c = path->nodes[level];
3046 if (path->locks[level])
3047 btrfs_tree_unlock(c);
3048 free_extent_buffer(c);
3049 path->nodes[level] = next;
3050 path->slots[level] = 0;
3051 path->locks[level] = 1;
3054 if (level == 1 && path->locks[1] && path->reada)
3055 reada_for_search(root, path, level, slot, 0);
3056 next = read_node_slot(root, next, 0);
3057 if (!path->skip_locking) {
3058 WARN_ON(!btrfs_tree_locked(path->nodes[level]));
3059 btrfs_tree_lock(next);
3063 unlock_up(path, 0, 1);
3067 int btrfs_previous_item(struct btrfs_root *root,
3068 struct btrfs_path *path, u64 min_objectid,
3071 struct btrfs_key found_key;
3072 struct extent_buffer *leaf;
3076 if (path->slots[0] == 0) {
3077 ret = btrfs_prev_leaf(root, path);
3083 leaf = path->nodes[0];
3084 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3085 if (found_key.type == type)