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);
1356 free_extent_buffer(tmp);
1357 b = read_node_slot(root, b, slot);
1360 if (!p->skip_locking)
1362 unlock_up(p, level, lowest_unlock);
1364 p->slots[level] = slot;
1365 if (ins_len > 0 && btrfs_leaf_free_space(root, b) <
1366 sizeof(struct btrfs_item) + ins_len) {
1367 int sret = split_leaf(trans, root, key,
1368 p, ins_len, ret == 0);
1373 unlock_up(p, level, lowest_unlock);
1381 * adjust the pointers going up the tree, starting at level
1382 * making sure the right key of each node is points to 'key'.
1383 * This is used after shifting pointers to the left, so it stops
1384 * fixing up pointers when a given leaf/node is not in slot 0 of the
1387 * If this fails to write a tree block, it returns -1, but continues
1388 * fixing up the blocks in ram so the tree is consistent.
1390 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1391 struct btrfs_root *root, struct btrfs_path *path,
1392 struct btrfs_disk_key *key, int level)
1396 struct extent_buffer *t;
1398 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1399 int tslot = path->slots[i];
1400 if (!path->nodes[i])
1403 btrfs_set_node_key(t, key, tslot);
1404 btrfs_mark_buffer_dirty(path->nodes[i]);
1412 * try to push data from one node into the next node left in the
1415 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1416 * error, and > 0 if there was no room in the left hand block.
1418 static int push_node_left(struct btrfs_trans_handle *trans,
1419 struct btrfs_root *root, struct extent_buffer *dst,
1420 struct extent_buffer *src, int empty)
1427 src_nritems = btrfs_header_nritems(src);
1428 dst_nritems = btrfs_header_nritems(dst);
1429 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1430 WARN_ON(btrfs_header_generation(src) != trans->transid);
1431 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1433 if (!empty && src_nritems <= 8)
1436 if (push_items <= 0) {
1441 push_items = min(src_nritems, push_items);
1442 if (push_items < src_nritems) {
1443 /* leave at least 8 pointers in the node if
1444 * we aren't going to empty it
1446 if (src_nritems - push_items < 8) {
1447 if (push_items <= 8)
1453 push_items = min(src_nritems - 8, push_items);
1455 copy_extent_buffer(dst, src,
1456 btrfs_node_key_ptr_offset(dst_nritems),
1457 btrfs_node_key_ptr_offset(0),
1458 push_items * sizeof(struct btrfs_key_ptr));
1460 if (push_items < src_nritems) {
1461 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1462 btrfs_node_key_ptr_offset(push_items),
1463 (src_nritems - push_items) *
1464 sizeof(struct btrfs_key_ptr));
1466 btrfs_set_header_nritems(src, src_nritems - push_items);
1467 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1468 btrfs_mark_buffer_dirty(src);
1469 btrfs_mark_buffer_dirty(dst);
1474 * try to push data from one node into the next node right in the
1477 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1478 * error, and > 0 if there was no room in the right hand block.
1480 * this will only push up to 1/2 the contents of the left node over
1482 static int balance_node_right(struct btrfs_trans_handle *trans,
1483 struct btrfs_root *root,
1484 struct extent_buffer *dst,
1485 struct extent_buffer *src)
1493 WARN_ON(btrfs_header_generation(src) != trans->transid);
1494 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1496 src_nritems = btrfs_header_nritems(src);
1497 dst_nritems = btrfs_header_nritems(dst);
1498 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1499 if (push_items <= 0) {
1503 if (src_nritems < 4) {
1507 max_push = src_nritems / 2 + 1;
1508 /* don't try to empty the node */
1509 if (max_push >= src_nritems) {
1513 if (max_push < push_items)
1514 push_items = max_push;
1516 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1517 btrfs_node_key_ptr_offset(0),
1519 sizeof(struct btrfs_key_ptr));
1521 copy_extent_buffer(dst, src,
1522 btrfs_node_key_ptr_offset(0),
1523 btrfs_node_key_ptr_offset(src_nritems - push_items),
1524 push_items * sizeof(struct btrfs_key_ptr));
1526 btrfs_set_header_nritems(src, src_nritems - push_items);
1527 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1529 btrfs_mark_buffer_dirty(src);
1530 btrfs_mark_buffer_dirty(dst);
1535 * helper function to insert a new root level in the tree.
1536 * A new node is allocated, and a single item is inserted to
1537 * point to the existing root
1539 * returns zero on success or < 0 on failure.
1541 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1542 struct btrfs_root *root,
1543 struct btrfs_path *path, int level)
1547 struct extent_buffer *lower;
1548 struct extent_buffer *c;
1549 struct extent_buffer *old;
1550 struct btrfs_disk_key lower_key;
1552 BUG_ON(path->nodes[level]);
1553 BUG_ON(path->nodes[level-1] != root->node);
1556 root_gen = trans->transid;
1560 lower = path->nodes[level-1];
1562 btrfs_item_key(lower, &lower_key, 0);
1564 btrfs_node_key(lower, &lower_key, 0);
1566 c = btrfs_alloc_free_block(trans, root, root->nodesize,
1567 root->root_key.objectid,
1568 root_gen, lower_key.objectid, level,
1569 root->node->start, 0);
1573 memset_extent_buffer(c, 0, 0, root->nodesize);
1574 btrfs_set_header_nritems(c, 1);
1575 btrfs_set_header_level(c, level);
1576 btrfs_set_header_bytenr(c, c->start);
1577 btrfs_set_header_generation(c, trans->transid);
1578 btrfs_set_header_owner(c, root->root_key.objectid);
1580 write_extent_buffer(c, root->fs_info->fsid,
1581 (unsigned long)btrfs_header_fsid(c),
1584 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1585 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1588 btrfs_set_node_key(c, &lower_key, 0);
1589 btrfs_set_node_blockptr(c, 0, lower->start);
1590 lower_gen = btrfs_header_generation(lower);
1591 WARN_ON(lower_gen == 0);
1593 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1595 btrfs_mark_buffer_dirty(c);
1597 spin_lock(&root->node_lock);
1600 spin_unlock(&root->node_lock);
1602 /* the super has an extra ref to root->node */
1603 free_extent_buffer(old);
1605 add_root_to_dirty_list(root);
1606 extent_buffer_get(c);
1607 path->nodes[level] = c;
1608 path->locks[level] = 1;
1609 path->slots[level] = 0;
1611 if (root->ref_cows && lower_gen != trans->transid) {
1612 struct btrfs_path *back_path = btrfs_alloc_path();
1614 mutex_lock(&root->fs_info->alloc_mutex);
1615 ret = btrfs_insert_extent_backref(trans,
1616 root->fs_info->extent_root,
1618 root->root_key.objectid,
1619 trans->transid, 0, 0);
1621 mutex_unlock(&root->fs_info->alloc_mutex);
1622 btrfs_free_path(back_path);
1628 * worker function to insert a single pointer in a node.
1629 * the node should have enough room for the pointer already
1631 * slot and level indicate where you want the key to go, and
1632 * blocknr is the block the key points to.
1634 * returns zero on success and < 0 on any error
1636 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
1637 *root, struct btrfs_path *path, struct btrfs_disk_key
1638 *key, u64 bytenr, int slot, int level)
1640 struct extent_buffer *lower;
1643 BUG_ON(!path->nodes[level]);
1644 lower = path->nodes[level];
1645 nritems = btrfs_header_nritems(lower);
1648 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
1650 if (slot != nritems) {
1651 memmove_extent_buffer(lower,
1652 btrfs_node_key_ptr_offset(slot + 1),
1653 btrfs_node_key_ptr_offset(slot),
1654 (nritems - slot) * sizeof(struct btrfs_key_ptr));
1656 btrfs_set_node_key(lower, key, slot);
1657 btrfs_set_node_blockptr(lower, slot, bytenr);
1658 WARN_ON(trans->transid == 0);
1659 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
1660 btrfs_set_header_nritems(lower, nritems + 1);
1661 btrfs_mark_buffer_dirty(lower);
1666 * split the node at the specified level in path in two.
1667 * The path is corrected to point to the appropriate node after the split
1669 * Before splitting this tries to make some room in the node by pushing
1670 * left and right, if either one works, it returns right away.
1672 * returns 0 on success and < 0 on failure
1674 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
1675 *root, struct btrfs_path *path, int level)
1678 struct extent_buffer *c;
1679 struct extent_buffer *split;
1680 struct btrfs_disk_key disk_key;
1686 c = path->nodes[level];
1687 WARN_ON(btrfs_header_generation(c) != trans->transid);
1688 if (c == root->node) {
1689 /* trying to split the root, lets make a new one */
1690 ret = insert_new_root(trans, root, path, level + 1);
1694 ret = push_nodes_for_insert(trans, root, path, level);
1695 c = path->nodes[level];
1696 if (!ret && btrfs_header_nritems(c) <
1697 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
1703 c_nritems = btrfs_header_nritems(c);
1705 root_gen = trans->transid;
1709 btrfs_node_key(c, &disk_key, 0);
1710 split = btrfs_alloc_free_block(trans, root, root->nodesize,
1711 root->root_key.objectid,
1713 btrfs_disk_key_objectid(&disk_key),
1714 level, c->start, 0);
1716 return PTR_ERR(split);
1718 btrfs_set_header_flags(split, btrfs_header_flags(c));
1719 btrfs_set_header_level(split, btrfs_header_level(c));
1720 btrfs_set_header_bytenr(split, split->start);
1721 btrfs_set_header_generation(split, trans->transid);
1722 btrfs_set_header_owner(split, root->root_key.objectid);
1723 btrfs_set_header_flags(split, 0);
1724 write_extent_buffer(split, root->fs_info->fsid,
1725 (unsigned long)btrfs_header_fsid(split),
1727 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
1728 (unsigned long)btrfs_header_chunk_tree_uuid(split),
1731 mid = (c_nritems + 1) / 2;
1733 copy_extent_buffer(split, c,
1734 btrfs_node_key_ptr_offset(0),
1735 btrfs_node_key_ptr_offset(mid),
1736 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
1737 btrfs_set_header_nritems(split, c_nritems - mid);
1738 btrfs_set_header_nritems(c, mid);
1741 btrfs_mark_buffer_dirty(c);
1742 btrfs_mark_buffer_dirty(split);
1744 btrfs_node_key(split, &disk_key, 0);
1745 wret = insert_ptr(trans, root, path, &disk_key, split->start,
1746 path->slots[level + 1] + 1,
1751 if (path->slots[level] >= mid) {
1752 path->slots[level] -= mid;
1753 btrfs_tree_unlock(c);
1754 free_extent_buffer(c);
1755 path->nodes[level] = split;
1756 path->slots[level + 1] += 1;
1758 btrfs_tree_unlock(split);
1759 free_extent_buffer(split);
1765 * how many bytes are required to store the items in a leaf. start
1766 * and nr indicate which items in the leaf to check. This totals up the
1767 * space used both by the item structs and the item data
1769 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
1772 int nritems = btrfs_header_nritems(l);
1773 int end = min(nritems, start + nr) - 1;
1777 data_len = btrfs_item_end_nr(l, start);
1778 data_len = data_len - btrfs_item_offset_nr(l, end);
1779 data_len += sizeof(struct btrfs_item) * nr;
1780 WARN_ON(data_len < 0);
1785 * The space between the end of the leaf items and
1786 * the start of the leaf data. IOW, how much room
1787 * the leaf has left for both items and data
1789 int btrfs_leaf_free_space(struct btrfs_root *root, struct extent_buffer *leaf)
1791 int nritems = btrfs_header_nritems(leaf);
1793 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
1795 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1796 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
1797 leaf_space_used(leaf, 0, nritems), nritems);
1803 * push some data in the path leaf to the right, trying to free up at
1804 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1806 * returns 1 if the push failed because the other node didn't have enough
1807 * room, 0 if everything worked out and < 0 if there were major errors.
1809 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
1810 *root, struct btrfs_path *path, int data_size,
1813 struct extent_buffer *left = path->nodes[0];
1814 struct extent_buffer *right;
1815 struct extent_buffer *upper;
1816 struct btrfs_disk_key disk_key;
1822 struct btrfs_item *item;
1830 slot = path->slots[1];
1831 if (!path->nodes[1]) {
1834 upper = path->nodes[1];
1835 if (slot >= btrfs_header_nritems(upper) - 1)
1838 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
1840 right = read_node_slot(root, upper, slot + 1);
1841 btrfs_tree_lock(right);
1842 free_space = btrfs_leaf_free_space(root, right);
1843 if (free_space < data_size + sizeof(struct btrfs_item))
1846 /* cow and double check */
1847 ret = btrfs_cow_block(trans, root, right, upper,
1852 free_space = btrfs_leaf_free_space(root, right);
1853 if (free_space < data_size + sizeof(struct btrfs_item))
1856 left_nritems = btrfs_header_nritems(left);
1857 if (left_nritems == 0)
1865 i = left_nritems - 1;
1867 item = btrfs_item_nr(left, i);
1869 if (path->slots[0] == i)
1870 push_space += data_size + sizeof(*item);
1872 if (!left->map_token) {
1873 map_extent_buffer(left, (unsigned long)item,
1874 sizeof(struct btrfs_item),
1875 &left->map_token, &left->kaddr,
1876 &left->map_start, &left->map_len,
1880 this_item_size = btrfs_item_size(left, item);
1881 if (this_item_size + sizeof(*item) + push_space > free_space)
1884 push_space += this_item_size + sizeof(*item);
1889 if (left->map_token) {
1890 unmap_extent_buffer(left, left->map_token, KM_USER1);
1891 left->map_token = NULL;
1894 if (push_items == 0)
1897 if (!empty && push_items == left_nritems)
1900 /* push left to right */
1901 right_nritems = btrfs_header_nritems(right);
1903 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
1904 push_space -= leaf_data_end(root, left);
1906 /* make room in the right data area */
1907 data_end = leaf_data_end(root, right);
1908 memmove_extent_buffer(right,
1909 btrfs_leaf_data(right) + data_end - push_space,
1910 btrfs_leaf_data(right) + data_end,
1911 BTRFS_LEAF_DATA_SIZE(root) - data_end);
1913 /* copy from the left data area */
1914 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
1915 BTRFS_LEAF_DATA_SIZE(root) - push_space,
1916 btrfs_leaf_data(left) + leaf_data_end(root, left),
1919 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
1920 btrfs_item_nr_offset(0),
1921 right_nritems * sizeof(struct btrfs_item));
1923 /* copy the items from left to right */
1924 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
1925 btrfs_item_nr_offset(left_nritems - push_items),
1926 push_items * sizeof(struct btrfs_item));
1928 /* update the item pointers */
1929 right_nritems += push_items;
1930 btrfs_set_header_nritems(right, right_nritems);
1931 push_space = BTRFS_LEAF_DATA_SIZE(root);
1932 for (i = 0; i < right_nritems; i++) {
1933 item = btrfs_item_nr(right, i);
1934 if (!right->map_token) {
1935 map_extent_buffer(right, (unsigned long)item,
1936 sizeof(struct btrfs_item),
1937 &right->map_token, &right->kaddr,
1938 &right->map_start, &right->map_len,
1941 push_space -= btrfs_item_size(right, item);
1942 btrfs_set_item_offset(right, item, push_space);
1945 if (right->map_token) {
1946 unmap_extent_buffer(right, right->map_token, KM_USER1);
1947 right->map_token = NULL;
1949 left_nritems -= push_items;
1950 btrfs_set_header_nritems(left, left_nritems);
1953 btrfs_mark_buffer_dirty(left);
1954 btrfs_mark_buffer_dirty(right);
1956 btrfs_item_key(right, &disk_key, 0);
1957 btrfs_set_node_key(upper, &disk_key, slot + 1);
1958 btrfs_mark_buffer_dirty(upper);
1960 /* then fixup the leaf pointer in the path */
1961 if (path->slots[0] >= left_nritems) {
1962 path->slots[0] -= left_nritems;
1963 if (btrfs_header_nritems(path->nodes[0]) == 0)
1964 clean_tree_block(trans, root, path->nodes[0]);
1965 btrfs_tree_unlock(path->nodes[0]);
1966 free_extent_buffer(path->nodes[0]);
1967 path->nodes[0] = right;
1968 path->slots[1] += 1;
1970 btrfs_tree_unlock(right);
1971 free_extent_buffer(right);
1976 btrfs_tree_unlock(right);
1977 free_extent_buffer(right);
1982 * push some data in the path leaf to the left, trying to free up at
1983 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1985 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
1986 *root, struct btrfs_path *path, int data_size,
1989 struct btrfs_disk_key disk_key;
1990 struct extent_buffer *right = path->nodes[0];
1991 struct extent_buffer *left;
1997 struct btrfs_item *item;
1998 u32 old_left_nritems;
2004 u32 old_left_item_size;
2006 slot = path->slots[1];
2009 if (!path->nodes[1])
2012 right_nritems = btrfs_header_nritems(right);
2013 if (right_nritems == 0) {
2017 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
2019 left = read_node_slot(root, path->nodes[1], slot - 1);
2020 btrfs_tree_lock(left);
2021 free_space = btrfs_leaf_free_space(root, left);
2022 if (free_space < data_size + sizeof(struct btrfs_item)) {
2027 /* cow and double check */
2028 ret = btrfs_cow_block(trans, root, left,
2029 path->nodes[1], slot - 1, &left);
2031 /* we hit -ENOSPC, but it isn't fatal here */
2036 free_space = btrfs_leaf_free_space(root, left);
2037 if (free_space < data_size + sizeof(struct btrfs_item)) {
2045 nr = right_nritems - 1;
2047 for (i = 0; i < nr; i++) {
2048 item = btrfs_item_nr(right, i);
2049 if (!right->map_token) {
2050 map_extent_buffer(right, (unsigned long)item,
2051 sizeof(struct btrfs_item),
2052 &right->map_token, &right->kaddr,
2053 &right->map_start, &right->map_len,
2057 if (path->slots[0] == i)
2058 push_space += data_size + sizeof(*item);
2060 this_item_size = btrfs_item_size(right, item);
2061 if (this_item_size + sizeof(*item) + push_space > free_space)
2065 push_space += this_item_size + sizeof(*item);
2068 if (right->map_token) {
2069 unmap_extent_buffer(right, right->map_token, KM_USER1);
2070 right->map_token = NULL;
2073 if (push_items == 0) {
2077 if (!empty && push_items == btrfs_header_nritems(right))
2080 /* push data from right to left */
2081 copy_extent_buffer(left, right,
2082 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2083 btrfs_item_nr_offset(0),
2084 push_items * sizeof(struct btrfs_item));
2086 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2087 btrfs_item_offset_nr(right, push_items -1);
2089 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2090 leaf_data_end(root, left) - push_space,
2091 btrfs_leaf_data(right) +
2092 btrfs_item_offset_nr(right, push_items - 1),
2094 old_left_nritems = btrfs_header_nritems(left);
2095 BUG_ON(old_left_nritems < 0);
2097 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2098 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2101 item = btrfs_item_nr(left, i);
2102 if (!left->map_token) {
2103 map_extent_buffer(left, (unsigned long)item,
2104 sizeof(struct btrfs_item),
2105 &left->map_token, &left->kaddr,
2106 &left->map_start, &left->map_len,
2110 ioff = btrfs_item_offset(left, item);
2111 btrfs_set_item_offset(left, item,
2112 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2114 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2115 if (left->map_token) {
2116 unmap_extent_buffer(left, left->map_token, KM_USER1);
2117 left->map_token = NULL;
2120 /* fixup right node */
2121 if (push_items > right_nritems) {
2122 printk("push items %d nr %u\n", push_items, right_nritems);
2126 if (push_items < right_nritems) {
2127 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2128 leaf_data_end(root, right);
2129 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2130 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2131 btrfs_leaf_data(right) +
2132 leaf_data_end(root, right), push_space);
2134 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2135 btrfs_item_nr_offset(push_items),
2136 (btrfs_header_nritems(right) - push_items) *
2137 sizeof(struct btrfs_item));
2139 right_nritems -= push_items;
2140 btrfs_set_header_nritems(right, right_nritems);
2141 push_space = BTRFS_LEAF_DATA_SIZE(root);
2142 for (i = 0; i < right_nritems; i++) {
2143 item = btrfs_item_nr(right, i);
2145 if (!right->map_token) {
2146 map_extent_buffer(right, (unsigned long)item,
2147 sizeof(struct btrfs_item),
2148 &right->map_token, &right->kaddr,
2149 &right->map_start, &right->map_len,
2153 push_space = push_space - btrfs_item_size(right, item);
2154 btrfs_set_item_offset(right, item, push_space);
2156 if (right->map_token) {
2157 unmap_extent_buffer(right, right->map_token, KM_USER1);
2158 right->map_token = NULL;
2161 btrfs_mark_buffer_dirty(left);
2163 btrfs_mark_buffer_dirty(right);
2165 btrfs_item_key(right, &disk_key, 0);
2166 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2170 /* then fixup the leaf pointer in the path */
2171 if (path->slots[0] < push_items) {
2172 path->slots[0] += old_left_nritems;
2173 if (btrfs_header_nritems(path->nodes[0]) == 0)
2174 clean_tree_block(trans, root, path->nodes[0]);
2175 btrfs_tree_unlock(path->nodes[0]);
2176 free_extent_buffer(path->nodes[0]);
2177 path->nodes[0] = left;
2178 path->slots[1] -= 1;
2180 btrfs_tree_unlock(left);
2181 free_extent_buffer(left);
2182 path->slots[0] -= push_items;
2184 BUG_ON(path->slots[0] < 0);
2187 btrfs_tree_unlock(left);
2188 free_extent_buffer(left);
2193 * split the path's leaf in two, making sure there is at least data_size
2194 * available for the resulting leaf level of the path.
2196 * returns 0 if all went well and < 0 on failure.
2198 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root
2199 *root, struct btrfs_key *ins_key,
2200 struct btrfs_path *path, int data_size, int extend)
2203 struct extent_buffer *l;
2207 struct extent_buffer *right;
2208 int space_needed = data_size + sizeof(struct btrfs_item);
2215 int num_doubles = 0;
2216 struct btrfs_disk_key disk_key;
2219 space_needed = data_size;
2222 root_gen = trans->transid;
2226 /* first try to make some room by pushing left and right */
2227 if (ins_key->type != BTRFS_DIR_ITEM_KEY) {
2228 wret = push_leaf_right(trans, root, path, data_size, 0);
2233 wret = push_leaf_left(trans, root, path, data_size, 0);
2239 /* did the pushes work? */
2240 if (btrfs_leaf_free_space(root, l) >= space_needed)
2244 if (!path->nodes[1]) {
2245 ret = insert_new_root(trans, root, path, 1);
2252 slot = path->slots[0];
2253 nritems = btrfs_header_nritems(l);
2254 mid = (nritems + 1)/ 2;
2256 btrfs_item_key(l, &disk_key, 0);
2258 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2259 root->root_key.objectid,
2260 root_gen, disk_key.objectid, 0,
2262 if (IS_ERR(right)) {
2264 return PTR_ERR(right);
2267 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2268 btrfs_set_header_bytenr(right, right->start);
2269 btrfs_set_header_generation(right, trans->transid);
2270 btrfs_set_header_owner(right, root->root_key.objectid);
2271 btrfs_set_header_level(right, 0);
2272 write_extent_buffer(right, root->fs_info->fsid,
2273 (unsigned long)btrfs_header_fsid(right),
2276 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2277 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2281 leaf_space_used(l, mid, nritems - mid) + space_needed >
2282 BTRFS_LEAF_DATA_SIZE(root)) {
2283 if (slot >= nritems) {
2284 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2285 btrfs_set_header_nritems(right, 0);
2286 wret = insert_ptr(trans, root, path,
2287 &disk_key, right->start,
2288 path->slots[1] + 1, 1);
2292 btrfs_tree_unlock(path->nodes[0]);
2293 free_extent_buffer(path->nodes[0]);
2294 path->nodes[0] = right;
2296 path->slots[1] += 1;
2297 btrfs_mark_buffer_dirty(right);
2301 if (mid != nritems &&
2302 leaf_space_used(l, mid, nritems - mid) +
2303 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2308 if (leaf_space_used(l, 0, mid + 1) + space_needed >
2309 BTRFS_LEAF_DATA_SIZE(root)) {
2310 if (!extend && slot == 0) {
2311 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2312 btrfs_set_header_nritems(right, 0);
2313 wret = insert_ptr(trans, root, path,
2319 btrfs_tree_unlock(path->nodes[0]);
2320 free_extent_buffer(path->nodes[0]);
2321 path->nodes[0] = right;
2323 if (path->slots[1] == 0) {
2324 wret = fixup_low_keys(trans, root,
2325 path, &disk_key, 1);
2329 btrfs_mark_buffer_dirty(right);
2331 } else if (extend && slot == 0) {
2335 if (mid != nritems &&
2336 leaf_space_used(l, mid, nritems - mid) +
2337 space_needed > BTRFS_LEAF_DATA_SIZE(root)) {
2343 nritems = nritems - mid;
2344 btrfs_set_header_nritems(right, nritems);
2345 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2347 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2348 btrfs_item_nr_offset(mid),
2349 nritems * sizeof(struct btrfs_item));
2351 copy_extent_buffer(right, l,
2352 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2353 data_copy_size, btrfs_leaf_data(l) +
2354 leaf_data_end(root, l), data_copy_size);
2356 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2357 btrfs_item_end_nr(l, mid);
2359 for (i = 0; i < nritems; i++) {
2360 struct btrfs_item *item = btrfs_item_nr(right, i);
2363 if (!right->map_token) {
2364 map_extent_buffer(right, (unsigned long)item,
2365 sizeof(struct btrfs_item),
2366 &right->map_token, &right->kaddr,
2367 &right->map_start, &right->map_len,
2371 ioff = btrfs_item_offset(right, item);
2372 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2375 if (right->map_token) {
2376 unmap_extent_buffer(right, right->map_token, KM_USER1);
2377 right->map_token = NULL;
2380 btrfs_set_header_nritems(l, mid);
2382 btrfs_item_key(right, &disk_key, 0);
2383 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2384 path->slots[1] + 1, 1);
2388 btrfs_mark_buffer_dirty(right);
2389 btrfs_mark_buffer_dirty(l);
2390 BUG_ON(path->slots[0] != slot);
2393 btrfs_tree_unlock(path->nodes[0]);
2394 free_extent_buffer(path->nodes[0]);
2395 path->nodes[0] = right;
2396 path->slots[0] -= mid;
2397 path->slots[1] += 1;
2399 btrfs_tree_unlock(right);
2400 free_extent_buffer(right);
2403 BUG_ON(path->slots[0] < 0);
2406 BUG_ON(num_doubles != 0);
2413 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2414 struct btrfs_root *root,
2415 struct btrfs_path *path,
2416 u32 new_size, int from_end)
2421 struct extent_buffer *leaf;
2422 struct btrfs_item *item;
2424 unsigned int data_end;
2425 unsigned int old_data_start;
2426 unsigned int old_size;
2427 unsigned int size_diff;
2430 slot_orig = path->slots[0];
2431 leaf = path->nodes[0];
2432 slot = path->slots[0];
2434 old_size = btrfs_item_size_nr(leaf, slot);
2435 if (old_size == new_size)
2438 nritems = btrfs_header_nritems(leaf);
2439 data_end = leaf_data_end(root, leaf);
2441 old_data_start = btrfs_item_offset_nr(leaf, slot);
2443 size_diff = old_size - new_size;
2446 BUG_ON(slot >= nritems);
2449 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2451 /* first correct the data pointers */
2452 for (i = slot; i < nritems; i++) {
2454 item = btrfs_item_nr(leaf, i);
2456 if (!leaf->map_token) {
2457 map_extent_buffer(leaf, (unsigned long)item,
2458 sizeof(struct btrfs_item),
2459 &leaf->map_token, &leaf->kaddr,
2460 &leaf->map_start, &leaf->map_len,
2464 ioff = btrfs_item_offset(leaf, item);
2465 btrfs_set_item_offset(leaf, item, ioff + size_diff);
2468 if (leaf->map_token) {
2469 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2470 leaf->map_token = NULL;
2473 /* shift the data */
2475 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2476 data_end + size_diff, btrfs_leaf_data(leaf) +
2477 data_end, old_data_start + new_size - data_end);
2479 struct btrfs_disk_key disk_key;
2482 btrfs_item_key(leaf, &disk_key, slot);
2484 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
2486 struct btrfs_file_extent_item *fi;
2488 fi = btrfs_item_ptr(leaf, slot,
2489 struct btrfs_file_extent_item);
2490 fi = (struct btrfs_file_extent_item *)(
2491 (unsigned long)fi - size_diff);
2493 if (btrfs_file_extent_type(leaf, fi) ==
2494 BTRFS_FILE_EXTENT_INLINE) {
2495 ptr = btrfs_item_ptr_offset(leaf, slot);
2496 memmove_extent_buffer(leaf, ptr,
2498 offsetof(struct btrfs_file_extent_item,
2503 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2504 data_end + size_diff, btrfs_leaf_data(leaf) +
2505 data_end, old_data_start - data_end);
2507 offset = btrfs_disk_key_offset(&disk_key);
2508 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
2509 btrfs_set_item_key(leaf, &disk_key, slot);
2511 fixup_low_keys(trans, root, path, &disk_key, 1);
2514 item = btrfs_item_nr(leaf, slot);
2515 btrfs_set_item_size(leaf, item, new_size);
2516 btrfs_mark_buffer_dirty(leaf);
2519 if (btrfs_leaf_free_space(root, leaf) < 0) {
2520 btrfs_print_leaf(root, leaf);
2526 int btrfs_extend_item(struct btrfs_trans_handle *trans,
2527 struct btrfs_root *root, struct btrfs_path *path,
2533 struct extent_buffer *leaf;
2534 struct btrfs_item *item;
2536 unsigned int data_end;
2537 unsigned int old_data;
2538 unsigned int old_size;
2541 slot_orig = path->slots[0];
2542 leaf = path->nodes[0];
2544 nritems = btrfs_header_nritems(leaf);
2545 data_end = leaf_data_end(root, leaf);
2547 if (btrfs_leaf_free_space(root, leaf) < data_size) {
2548 btrfs_print_leaf(root, leaf);
2551 slot = path->slots[0];
2552 old_data = btrfs_item_end_nr(leaf, slot);
2555 if (slot >= nritems) {
2556 btrfs_print_leaf(root, leaf);
2557 printk("slot %d too large, nritems %d\n", slot, nritems);
2562 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2564 /* first correct the data pointers */
2565 for (i = slot; i < nritems; i++) {
2567 item = btrfs_item_nr(leaf, i);
2569 if (!leaf->map_token) {
2570 map_extent_buffer(leaf, (unsigned long)item,
2571 sizeof(struct btrfs_item),
2572 &leaf->map_token, &leaf->kaddr,
2573 &leaf->map_start, &leaf->map_len,
2576 ioff = btrfs_item_offset(leaf, item);
2577 btrfs_set_item_offset(leaf, item, ioff - data_size);
2580 if (leaf->map_token) {
2581 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2582 leaf->map_token = NULL;
2585 /* shift the data */
2586 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2587 data_end - data_size, btrfs_leaf_data(leaf) +
2588 data_end, old_data - data_end);
2590 data_end = old_data;
2591 old_size = btrfs_item_size_nr(leaf, slot);
2592 item = btrfs_item_nr(leaf, slot);
2593 btrfs_set_item_size(leaf, item, old_size + data_size);
2594 btrfs_mark_buffer_dirty(leaf);
2597 if (btrfs_leaf_free_space(root, leaf) < 0) {
2598 btrfs_print_leaf(root, leaf);
2605 * Given a key and some data, insert an item into the tree.
2606 * This does all the path init required, making room in the tree if needed.
2608 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
2609 struct btrfs_root *root,
2610 struct btrfs_path *path,
2611 struct btrfs_key *cpu_key, u32 *data_size,
2614 struct extent_buffer *leaf;
2615 struct btrfs_item *item;
2623 unsigned int data_end;
2624 struct btrfs_disk_key disk_key;
2626 for (i = 0; i < nr; i++) {
2627 total_data += data_size[i];
2630 total_size = total_data + (nr - 1) * sizeof(struct btrfs_item);
2631 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
2638 slot_orig = path->slots[0];
2639 leaf = path->nodes[0];
2641 nritems = btrfs_header_nritems(leaf);
2642 data_end = leaf_data_end(root, leaf);
2644 if (btrfs_leaf_free_space(root, leaf) <
2645 sizeof(struct btrfs_item) + total_size) {
2646 btrfs_print_leaf(root, leaf);
2647 printk("not enough freespace need %u have %d\n",
2648 total_size, btrfs_leaf_free_space(root, leaf));
2652 slot = path->slots[0];
2655 if (slot != nritems) {
2657 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
2659 if (old_data < data_end) {
2660 btrfs_print_leaf(root, leaf);
2661 printk("slot %d old_data %d data_end %d\n",
2662 slot, old_data, data_end);
2666 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2668 /* first correct the data pointers */
2669 WARN_ON(leaf->map_token);
2670 for (i = slot; i < nritems; i++) {
2673 item = btrfs_item_nr(leaf, i);
2674 if (!leaf->map_token) {
2675 map_extent_buffer(leaf, (unsigned long)item,
2676 sizeof(struct btrfs_item),
2677 &leaf->map_token, &leaf->kaddr,
2678 &leaf->map_start, &leaf->map_len,
2682 ioff = btrfs_item_offset(leaf, item);
2683 btrfs_set_item_offset(leaf, item, ioff - total_data);
2685 if (leaf->map_token) {
2686 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2687 leaf->map_token = NULL;
2690 /* shift the items */
2691 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
2692 btrfs_item_nr_offset(slot),
2693 (nritems - slot) * sizeof(struct btrfs_item));
2695 /* shift the data */
2696 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2697 data_end - total_data, btrfs_leaf_data(leaf) +
2698 data_end, old_data - data_end);
2699 data_end = old_data;
2702 /* setup the item for the new data */
2703 for (i = 0; i < nr; i++) {
2704 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
2705 btrfs_set_item_key(leaf, &disk_key, slot + i);
2706 item = btrfs_item_nr(leaf, slot + i);
2707 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
2708 data_end -= data_size[i];
2709 btrfs_set_item_size(leaf, item, data_size[i]);
2711 btrfs_set_header_nritems(leaf, nritems + nr);
2712 btrfs_mark_buffer_dirty(leaf);
2716 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
2717 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
2720 if (btrfs_leaf_free_space(root, leaf) < 0) {
2721 btrfs_print_leaf(root, leaf);
2729 * Given a key and some data, insert an item into the tree.
2730 * This does all the path init required, making room in the tree if needed.
2732 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
2733 *root, struct btrfs_key *cpu_key, void *data, u32
2737 struct btrfs_path *path;
2738 struct extent_buffer *leaf;
2741 path = btrfs_alloc_path();
2743 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
2745 leaf = path->nodes[0];
2746 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
2747 write_extent_buffer(leaf, data, ptr, data_size);
2748 btrfs_mark_buffer_dirty(leaf);
2750 btrfs_free_path(path);
2755 * delete the pointer from a given node.
2757 * If the delete empties a node, the node is removed from the tree,
2758 * continuing all the way the root if required. The root is converted into
2759 * a leaf if all the nodes are emptied.
2761 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2762 struct btrfs_path *path, int level, int slot)
2764 struct extent_buffer *parent = path->nodes[level];
2769 nritems = btrfs_header_nritems(parent);
2770 if (slot != nritems -1) {
2771 memmove_extent_buffer(parent,
2772 btrfs_node_key_ptr_offset(slot),
2773 btrfs_node_key_ptr_offset(slot + 1),
2774 sizeof(struct btrfs_key_ptr) *
2775 (nritems - slot - 1));
2778 btrfs_set_header_nritems(parent, nritems);
2779 if (nritems == 0 && parent == root->node) {
2780 BUG_ON(btrfs_header_level(root->node) != 1);
2781 /* just turn the root into a leaf and break */
2782 btrfs_set_header_level(root->node, 0);
2783 } else if (slot == 0) {
2784 struct btrfs_disk_key disk_key;
2786 btrfs_node_key(parent, &disk_key, 0);
2787 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
2791 btrfs_mark_buffer_dirty(parent);
2796 * delete the item at the leaf level in path. If that empties
2797 * the leaf, remove it from the tree
2799 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
2800 struct btrfs_path *path, int slot, int nr)
2802 struct extent_buffer *leaf;
2803 struct btrfs_item *item;
2811 leaf = path->nodes[0];
2812 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
2814 for (i = 0; i < nr; i++)
2815 dsize += btrfs_item_size_nr(leaf, slot + i);
2817 nritems = btrfs_header_nritems(leaf);
2819 if (slot + nr != nritems) {
2821 int data_end = leaf_data_end(root, leaf);
2823 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
2825 btrfs_leaf_data(leaf) + data_end,
2826 last_off - data_end);
2828 for (i = slot + nr; i < nritems; i++) {
2831 item = btrfs_item_nr(leaf, i);
2832 if (!leaf->map_token) {
2833 map_extent_buffer(leaf, (unsigned long)item,
2834 sizeof(struct btrfs_item),
2835 &leaf->map_token, &leaf->kaddr,
2836 &leaf->map_start, &leaf->map_len,
2839 ioff = btrfs_item_offset(leaf, item);
2840 btrfs_set_item_offset(leaf, item, ioff + dsize);
2843 if (leaf->map_token) {
2844 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
2845 leaf->map_token = NULL;
2848 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
2849 btrfs_item_nr_offset(slot + nr),
2850 sizeof(struct btrfs_item) *
2851 (nritems - slot - nr));
2853 btrfs_set_header_nritems(leaf, nritems - nr);
2856 /* delete the leaf if we've emptied it */
2858 if (leaf == root->node) {
2859 btrfs_set_header_level(leaf, 0);
2861 u64 root_gen = btrfs_header_generation(path->nodes[1]);
2862 wret = del_ptr(trans, root, path, 1, path->slots[1]);
2865 wret = btrfs_free_extent(trans, root,
2866 leaf->start, leaf->len,
2867 btrfs_header_owner(path->nodes[1]),
2873 int used = leaf_space_used(leaf, 0, nritems);
2875 struct btrfs_disk_key disk_key;
2877 btrfs_item_key(leaf, &disk_key, 0);
2878 wret = fixup_low_keys(trans, root, path,
2884 /* delete the leaf if it is mostly empty */
2885 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
2886 /* push_leaf_left fixes the path.
2887 * make sure the path still points to our leaf
2888 * for possible call to del_ptr below
2890 slot = path->slots[1];
2891 extent_buffer_get(leaf);
2893 wret = push_leaf_left(trans, root, path, 1, 1);
2894 if (wret < 0 && wret != -ENOSPC)
2897 if (path->nodes[0] == leaf &&
2898 btrfs_header_nritems(leaf)) {
2899 wret = push_leaf_right(trans, root, path, 1, 1);
2900 if (wret < 0 && wret != -ENOSPC)
2904 if (btrfs_header_nritems(leaf) == 0) {
2906 u64 bytenr = leaf->start;
2907 u32 blocksize = leaf->len;
2909 root_gen = btrfs_header_generation(
2912 wret = del_ptr(trans, root, path, 1, slot);
2916 free_extent_buffer(leaf);
2917 wret = btrfs_free_extent(trans, root, bytenr,
2919 btrfs_header_owner(path->nodes[1]),
2924 /* if we're still in the path, make sure
2925 * we're dirty. Otherwise, one of the
2926 * push_leaf functions must have already
2927 * dirtied this buffer
2929 if (path->nodes[0] == leaf)
2930 btrfs_mark_buffer_dirty(leaf);
2931 free_extent_buffer(leaf);
2934 btrfs_mark_buffer_dirty(leaf);
2941 * search the tree again to find a leaf with lesser keys
2942 * returns 0 if it found something or 1 if there are no lesser leaves.
2943 * returns < 0 on io errors.
2945 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
2947 struct btrfs_key key;
2948 struct btrfs_disk_key found_key;
2951 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
2955 else if (key.type > 0)
2957 else if (key.objectid > 0)
2962 btrfs_release_path(root, path);
2963 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2966 btrfs_item_key(path->nodes[0], &found_key, 0);
2967 ret = comp_keys(&found_key, &key);
2974 * search the tree again to find a leaf with greater keys
2975 * returns 0 if it found something or 1 if there are no greater leaves.
2976 * returns < 0 on io errors.
2978 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
2982 struct extent_buffer *c;
2983 struct extent_buffer *next = NULL;
2984 struct btrfs_key key;
2988 nritems = btrfs_header_nritems(path->nodes[0]);
2993 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
2995 btrfs_release_path(root, path);
2996 path->keep_locks = 1;
2997 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2998 path->keep_locks = 0;
3003 nritems = btrfs_header_nritems(path->nodes[0]);
3005 * by releasing the path above we dropped all our locks. A balance
3006 * could have added more items next to the key that used to be
3007 * at the very end of the block. So, check again here and
3008 * advance the path if there are now more items available.
3010 if (nritems > 0 && path->slots[0] < nritems - 1) {
3015 while(level < BTRFS_MAX_LEVEL) {
3016 if (!path->nodes[level])
3019 slot = path->slots[level] + 1;
3020 c = path->nodes[level];
3021 if (slot >= btrfs_header_nritems(c)) {
3023 if (level == BTRFS_MAX_LEVEL) {
3030 btrfs_tree_unlock(next);
3031 free_extent_buffer(next);
3034 if (level == 1 && path->locks[1] && path->reada)
3035 reada_for_search(root, path, level, slot, 0);
3037 next = read_node_slot(root, c, slot);
3038 if (!path->skip_locking) {
3039 WARN_ON(!btrfs_tree_locked(c));
3040 btrfs_tree_lock(next);
3044 path->slots[level] = slot;
3047 c = path->nodes[level];
3048 if (path->locks[level])
3049 btrfs_tree_unlock(c);
3050 free_extent_buffer(c);
3051 path->nodes[level] = next;
3052 path->slots[level] = 0;
3053 if (!path->skip_locking)
3054 path->locks[level] = 1;
3057 if (level == 1 && path->locks[1] && path->reada)
3058 reada_for_search(root, path, level, slot, 0);
3059 next = read_node_slot(root, next, 0);
3060 if (!path->skip_locking) {
3061 WARN_ON(!btrfs_tree_locked(path->nodes[level]));
3062 btrfs_tree_lock(next);
3066 unlock_up(path, 0, 1);
3070 int btrfs_previous_item(struct btrfs_root *root,
3071 struct btrfs_path *path, u64 min_objectid,
3074 struct btrfs_key found_key;
3075 struct extent_buffer *leaf;
3079 if (path->slots[0] == 0) {
3080 ret = btrfs_prev_leaf(root, path);
3086 leaf = path->nodes[0];
3087 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3088 if (found_key.type == type)