2 * Copyright (C) 2007,2008 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);
40 static int setup_items_for_insert(struct btrfs_trans_handle *trans,
41 struct btrfs_root *root, struct btrfs_path *path,
42 struct btrfs_key *cpu_key, u32 *data_size,
43 u32 total_data, u32 total_size, int nr);
46 struct btrfs_path *btrfs_alloc_path(void)
48 struct btrfs_path *path;
49 path = kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS);
56 * set all locked nodes in the path to blocking locks. This should
57 * be done before scheduling
59 noinline void btrfs_set_path_blocking(struct btrfs_path *p)
62 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
63 if (p->nodes[i] && p->locks[i])
64 btrfs_set_lock_blocking(p->nodes[i]);
69 * reset all the locked nodes in the patch to spinning locks.
71 * held is used to keep lockdep happy, when lockdep is enabled
72 * we set held to a blocking lock before we go around and
73 * retake all the spinlocks in the path. You can safely use NULL
76 noinline void btrfs_clear_path_blocking(struct btrfs_path *p,
77 struct extent_buffer *held)
81 #ifdef CONFIG_DEBUG_LOCK_ALLOC
82 /* lockdep really cares that we take all of these spinlocks
83 * in the right order. If any of the locks in the path are not
84 * currently blocking, it is going to complain. So, make really
85 * really sure by forcing the path to blocking before we clear
89 btrfs_set_lock_blocking(held);
90 btrfs_set_path_blocking(p);
93 for (i = BTRFS_MAX_LEVEL - 1; i >= 0; i--) {
94 if (p->nodes[i] && p->locks[i])
95 btrfs_clear_lock_blocking(p->nodes[i]);
98 #ifdef CONFIG_DEBUG_LOCK_ALLOC
100 btrfs_clear_lock_blocking(held);
104 /* this also releases the path */
105 void btrfs_free_path(struct btrfs_path *p)
107 btrfs_release_path(NULL, p);
108 kmem_cache_free(btrfs_path_cachep, p);
112 * path release drops references on the extent buffers in the path
113 * and it drops any locks held by this path
115 * It is safe to call this on paths that no locks or extent buffers held.
117 noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
121 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
126 btrfs_tree_unlock(p->nodes[i]);
129 free_extent_buffer(p->nodes[i]);
135 * safely gets a reference on the root node of a tree. A lock
136 * is not taken, so a concurrent writer may put a different node
137 * at the root of the tree. See btrfs_lock_root_node for the
140 * The extent buffer returned by this has a reference taken, so
141 * it won't disappear. It may stop being the root of the tree
142 * at any time because there are no locks held.
144 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
146 struct extent_buffer *eb;
147 spin_lock(&root->node_lock);
149 extent_buffer_get(eb);
150 spin_unlock(&root->node_lock);
154 /* loop around taking references on and locking the root node of the
155 * tree until you end up with a lock on the root. A locked buffer
156 * is returned, with a reference held.
158 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
160 struct extent_buffer *eb;
163 eb = btrfs_root_node(root);
166 spin_lock(&root->node_lock);
167 if (eb == root->node) {
168 spin_unlock(&root->node_lock);
171 spin_unlock(&root->node_lock);
173 btrfs_tree_unlock(eb);
174 free_extent_buffer(eb);
179 /* cowonly root (everything not a reference counted cow subvolume), just get
180 * put onto a simple dirty list. transaction.c walks this to make sure they
181 * get properly updated on disk.
183 static void add_root_to_dirty_list(struct btrfs_root *root)
185 if (root->track_dirty && list_empty(&root->dirty_list)) {
186 list_add(&root->dirty_list,
187 &root->fs_info->dirty_cowonly_roots);
192 * used by snapshot creation to make a copy of a root for a tree with
193 * a given objectid. The buffer with the new root node is returned in
194 * cow_ret, and this func returns zero on success or a negative error code.
196 int btrfs_copy_root(struct btrfs_trans_handle *trans,
197 struct btrfs_root *root,
198 struct extent_buffer *buf,
199 struct extent_buffer **cow_ret, u64 new_root_objectid)
201 struct extent_buffer *cow;
205 struct btrfs_disk_key disk_key;
207 WARN_ON(root->ref_cows && trans->transid !=
208 root->fs_info->running_transaction->transid);
209 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
211 level = btrfs_header_level(buf);
212 nritems = btrfs_header_nritems(buf);
214 btrfs_item_key(buf, &disk_key, 0);
216 btrfs_node_key(buf, &disk_key, 0);
218 cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
219 new_root_objectid, &disk_key, level,
224 copy_extent_buffer(cow, buf, 0, 0, cow->len);
225 btrfs_set_header_bytenr(cow, cow->start);
226 btrfs_set_header_generation(cow, trans->transid);
227 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
228 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
229 BTRFS_HEADER_FLAG_RELOC);
230 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
231 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
233 btrfs_set_header_owner(cow, new_root_objectid);
235 write_extent_buffer(cow, root->fs_info->fsid,
236 (unsigned long)btrfs_header_fsid(cow),
239 WARN_ON(btrfs_header_generation(buf) > trans->transid);
240 if (new_root_objectid == BTRFS_TREE_RELOC_OBJECTID)
241 ret = btrfs_inc_ref(trans, root, cow, 1);
243 ret = btrfs_inc_ref(trans, root, cow, 0);
248 btrfs_mark_buffer_dirty(cow);
254 * check if the tree block can be shared by multiple trees
256 int btrfs_block_can_be_shared(struct btrfs_root *root,
257 struct extent_buffer *buf)
260 * Tree blocks not in refernece counted trees and tree roots
261 * are never shared. If a block was allocated after the last
262 * snapshot and the block was not allocated by tree relocation,
263 * we know the block is not shared.
265 if (root->ref_cows &&
266 buf != root->node && buf != root->commit_root &&
267 (btrfs_header_generation(buf) <=
268 btrfs_root_last_snapshot(&root->root_item) ||
269 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
271 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
272 if (root->ref_cows &&
273 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
279 static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans,
280 struct btrfs_root *root,
281 struct extent_buffer *buf,
282 struct extent_buffer *cow)
291 * Backrefs update rules:
293 * Always use full backrefs for extent pointers in tree block
294 * allocated by tree relocation.
296 * If a shared tree block is no longer referenced by its owner
297 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
298 * use full backrefs for extent pointers in tree block.
300 * If a tree block is been relocating
301 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
302 * use full backrefs for extent pointers in tree block.
303 * The reason for this is some operations (such as drop tree)
304 * are only allowed for blocks use full backrefs.
307 if (btrfs_block_can_be_shared(root, buf)) {
308 ret = btrfs_lookup_extent_info(trans, root, buf->start,
309 buf->len, &refs, &flags);
314 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
315 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
316 flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
321 owner = btrfs_header_owner(buf);
322 BUG_ON(owner == BTRFS_TREE_RELOC_OBJECTID &&
323 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF));
326 if ((owner == root->root_key.objectid ||
327 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) &&
328 !(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) {
329 ret = btrfs_inc_ref(trans, root, buf, 1);
332 if (root->root_key.objectid ==
333 BTRFS_TREE_RELOC_OBJECTID) {
334 ret = btrfs_dec_ref(trans, root, buf, 0);
336 ret = btrfs_inc_ref(trans, root, cow, 1);
339 new_flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF;
342 if (root->root_key.objectid ==
343 BTRFS_TREE_RELOC_OBJECTID)
344 ret = btrfs_inc_ref(trans, root, cow, 1);
346 ret = btrfs_inc_ref(trans, root, cow, 0);
349 if (new_flags != 0) {
350 ret = btrfs_set_disk_extent_flags(trans, root,
357 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) {
358 if (root->root_key.objectid ==
359 BTRFS_TREE_RELOC_OBJECTID)
360 ret = btrfs_inc_ref(trans, root, cow, 1);
362 ret = btrfs_inc_ref(trans, root, cow, 0);
364 ret = btrfs_dec_ref(trans, root, buf, 1);
367 clean_tree_block(trans, root, buf);
373 * does the dirty work in cow of a single block. The parent block (if
374 * supplied) is updated to point to the new cow copy. The new buffer is marked
375 * dirty and returned locked. If you modify the block it needs to be marked
378 * search_start -- an allocation hint for the new block
380 * empty_size -- a hint that you plan on doing more cow. This is the size in
381 * bytes the allocator should try to find free next to the block it returns.
382 * This is just a hint and may be ignored by the allocator.
384 static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
385 struct btrfs_root *root,
386 struct extent_buffer *buf,
387 struct extent_buffer *parent, int parent_slot,
388 struct extent_buffer **cow_ret,
389 u64 search_start, u64 empty_size)
391 struct btrfs_disk_key disk_key;
392 struct extent_buffer *cow;
400 btrfs_assert_tree_locked(buf);
402 WARN_ON(root->ref_cows && trans->transid !=
403 root->fs_info->running_transaction->transid);
404 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
406 level = btrfs_header_level(buf);
409 btrfs_item_key(buf, &disk_key, 0);
411 btrfs_node_key(buf, &disk_key, 0);
413 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
415 parent_start = parent->start;
421 cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
422 root->root_key.objectid, &disk_key,
423 level, search_start, empty_size);
427 /* cow is set to blocking by btrfs_init_new_buffer */
429 copy_extent_buffer(cow, buf, 0, 0, cow->len);
430 btrfs_set_header_bytenr(cow, cow->start);
431 btrfs_set_header_generation(cow, trans->transid);
432 btrfs_set_header_backref_rev(cow, BTRFS_MIXED_BACKREF_REV);
433 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN |
434 BTRFS_HEADER_FLAG_RELOC);
435 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
436 btrfs_set_header_flag(cow, BTRFS_HEADER_FLAG_RELOC);
438 btrfs_set_header_owner(cow, root->root_key.objectid);
440 write_extent_buffer(cow, root->fs_info->fsid,
441 (unsigned long)btrfs_header_fsid(cow),
444 update_ref_for_cow(trans, root, buf, cow);
446 if (buf == root->node) {
447 WARN_ON(parent && parent != buf);
448 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID ||
449 btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)
450 parent_start = buf->start;
454 spin_lock(&root->node_lock);
456 extent_buffer_get(cow);
457 spin_unlock(&root->node_lock);
459 btrfs_free_tree_block(trans, root, buf->start, buf->len,
460 parent_start, root->root_key.objectid, level);
461 free_extent_buffer(buf);
462 add_root_to_dirty_list(root);
464 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
465 parent_start = parent->start;
469 WARN_ON(trans->transid != btrfs_header_generation(parent));
470 btrfs_set_node_blockptr(parent, parent_slot,
472 btrfs_set_node_ptr_generation(parent, parent_slot,
474 btrfs_mark_buffer_dirty(parent);
475 btrfs_free_tree_block(trans, root, buf->start, buf->len,
476 parent_start, root->root_key.objectid, level);
479 btrfs_tree_unlock(buf);
480 free_extent_buffer(buf);
481 btrfs_mark_buffer_dirty(cow);
486 static inline int should_cow_block(struct btrfs_trans_handle *trans,
487 struct btrfs_root *root,
488 struct extent_buffer *buf)
490 if (btrfs_header_generation(buf) == trans->transid &&
491 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN) &&
492 !(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID &&
493 btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))
499 * cows a single block, see __btrfs_cow_block for the real work.
500 * This version of it has extra checks so that a block isn't cow'd more than
501 * once per transaction, as long as it hasn't been written yet
503 noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
504 struct btrfs_root *root, struct extent_buffer *buf,
505 struct extent_buffer *parent, int parent_slot,
506 struct extent_buffer **cow_ret)
511 if (trans->transaction != root->fs_info->running_transaction) {
512 printk(KERN_CRIT "trans %llu running %llu\n",
513 (unsigned long long)trans->transid,
515 root->fs_info->running_transaction->transid);
518 if (trans->transid != root->fs_info->generation) {
519 printk(KERN_CRIT "trans %llu running %llu\n",
520 (unsigned long long)trans->transid,
521 (unsigned long long)root->fs_info->generation);
525 if (!should_cow_block(trans, root, buf)) {
530 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
533 btrfs_set_lock_blocking(parent);
534 btrfs_set_lock_blocking(buf);
536 ret = __btrfs_cow_block(trans, root, buf, parent,
537 parent_slot, cow_ret, search_start, 0);
542 * helper function for defrag to decide if two blocks pointed to by a
543 * node are actually close by
545 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
547 if (blocknr < other && other - (blocknr + blocksize) < 32768)
549 if (blocknr > other && blocknr - (other + blocksize) < 32768)
555 * compare two keys in a memcmp fashion
557 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
561 btrfs_disk_key_to_cpu(&k1, disk);
563 return btrfs_comp_cpu_keys(&k1, k2);
567 * same as comp_keys only with two btrfs_key's
569 int btrfs_comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
571 if (k1->objectid > k2->objectid)
573 if (k1->objectid < k2->objectid)
575 if (k1->type > k2->type)
577 if (k1->type < k2->type)
579 if (k1->offset > k2->offset)
581 if (k1->offset < k2->offset)
587 * this is used by the defrag code to go through all the
588 * leaves pointed to by a node and reallocate them so that
589 * disk order is close to key order
591 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
592 struct btrfs_root *root, struct extent_buffer *parent,
593 int start_slot, int cache_only, u64 *last_ret,
594 struct btrfs_key *progress)
596 struct extent_buffer *cur;
599 u64 search_start = *last_ret;
609 int progress_passed = 0;
610 struct btrfs_disk_key disk_key;
612 parent_level = btrfs_header_level(parent);
613 if (cache_only && parent_level != 1)
616 if (trans->transaction != root->fs_info->running_transaction)
618 if (trans->transid != root->fs_info->generation)
621 parent_nritems = btrfs_header_nritems(parent);
622 blocksize = btrfs_level_size(root, parent_level - 1);
623 end_slot = parent_nritems;
625 if (parent_nritems == 1)
628 btrfs_set_lock_blocking(parent);
630 for (i = start_slot; i < end_slot; i++) {
633 if (!parent->map_token) {
634 map_extent_buffer(parent,
635 btrfs_node_key_ptr_offset(i),
636 sizeof(struct btrfs_key_ptr),
637 &parent->map_token, &parent->kaddr,
638 &parent->map_start, &parent->map_len,
641 btrfs_node_key(parent, &disk_key, i);
642 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
646 blocknr = btrfs_node_blockptr(parent, i);
647 gen = btrfs_node_ptr_generation(parent, i);
649 last_block = blocknr;
652 other = btrfs_node_blockptr(parent, i - 1);
653 close = close_blocks(blocknr, other, blocksize);
655 if (!close && i < end_slot - 2) {
656 other = btrfs_node_blockptr(parent, i + 1);
657 close = close_blocks(blocknr, other, blocksize);
660 last_block = blocknr;
663 if (parent->map_token) {
664 unmap_extent_buffer(parent, parent->map_token,
666 parent->map_token = NULL;
669 cur = btrfs_find_tree_block(root, blocknr, blocksize);
671 uptodate = btrfs_buffer_uptodate(cur, gen);
674 if (!cur || !uptodate) {
676 free_extent_buffer(cur);
680 cur = read_tree_block(root, blocknr,
682 } else if (!uptodate) {
683 btrfs_read_buffer(cur, gen);
686 if (search_start == 0)
687 search_start = last_block;
689 btrfs_tree_lock(cur);
690 btrfs_set_lock_blocking(cur);
691 err = __btrfs_cow_block(trans, root, cur, parent, i,
694 (end_slot - i) * blocksize));
696 btrfs_tree_unlock(cur);
697 free_extent_buffer(cur);
700 search_start = cur->start;
701 last_block = cur->start;
702 *last_ret = search_start;
703 btrfs_tree_unlock(cur);
704 free_extent_buffer(cur);
706 if (parent->map_token) {
707 unmap_extent_buffer(parent, parent->map_token,
709 parent->map_token = NULL;
715 * The leaf data grows from end-to-front in the node.
716 * this returns the address of the start of the last item,
717 * which is the stop of the leaf data stack
719 static inline unsigned int leaf_data_end(struct btrfs_root *root,
720 struct extent_buffer *leaf)
722 u32 nr = btrfs_header_nritems(leaf);
724 return BTRFS_LEAF_DATA_SIZE(root);
725 return btrfs_item_offset_nr(leaf, nr - 1);
729 * extra debugging checks to make sure all the items in a key are
730 * well formed and in the proper order
732 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
735 struct extent_buffer *parent = NULL;
736 struct extent_buffer *node = path->nodes[level];
737 struct btrfs_disk_key parent_key;
738 struct btrfs_disk_key node_key;
741 struct btrfs_key cpukey;
742 u32 nritems = btrfs_header_nritems(node);
744 if (path->nodes[level + 1])
745 parent = path->nodes[level + 1];
747 slot = path->slots[level];
748 BUG_ON(nritems == 0);
750 parent_slot = path->slots[level + 1];
751 btrfs_node_key(parent, &parent_key, parent_slot);
752 btrfs_node_key(node, &node_key, 0);
753 BUG_ON(memcmp(&parent_key, &node_key,
754 sizeof(struct btrfs_disk_key)));
755 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
756 btrfs_header_bytenr(node));
758 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
760 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
761 btrfs_node_key(node, &node_key, slot);
762 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
764 if (slot < nritems - 1) {
765 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
766 btrfs_node_key(node, &node_key, slot);
767 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
773 * extra checking to make sure all the items in a leaf are
774 * well formed and in the proper order
776 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
779 struct extent_buffer *leaf = path->nodes[level];
780 struct extent_buffer *parent = NULL;
782 struct btrfs_key cpukey;
783 struct btrfs_disk_key parent_key;
784 struct btrfs_disk_key leaf_key;
785 int slot = path->slots[0];
787 u32 nritems = btrfs_header_nritems(leaf);
789 if (path->nodes[level + 1])
790 parent = path->nodes[level + 1];
796 parent_slot = path->slots[level + 1];
797 btrfs_node_key(parent, &parent_key, parent_slot);
798 btrfs_item_key(leaf, &leaf_key, 0);
800 BUG_ON(memcmp(&parent_key, &leaf_key,
801 sizeof(struct btrfs_disk_key)));
802 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
803 btrfs_header_bytenr(leaf));
805 if (slot != 0 && slot < nritems - 1) {
806 btrfs_item_key(leaf, &leaf_key, slot);
807 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
808 if (comp_keys(&leaf_key, &cpukey) <= 0) {
809 btrfs_print_leaf(root, leaf);
810 printk(KERN_CRIT "slot %d offset bad key\n", slot);
813 if (btrfs_item_offset_nr(leaf, slot - 1) !=
814 btrfs_item_end_nr(leaf, slot)) {
815 btrfs_print_leaf(root, leaf);
816 printk(KERN_CRIT "slot %d offset bad\n", slot);
820 if (slot < nritems - 1) {
821 btrfs_item_key(leaf, &leaf_key, slot);
822 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
823 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
824 if (btrfs_item_offset_nr(leaf, slot) !=
825 btrfs_item_end_nr(leaf, slot + 1)) {
826 btrfs_print_leaf(root, leaf);
827 printk(KERN_CRIT "slot %d offset bad\n", slot);
831 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
832 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
836 static noinline int check_block(struct btrfs_root *root,
837 struct btrfs_path *path, int level)
841 return check_leaf(root, path, level);
842 return check_node(root, path, level);
846 * search for key in the extent_buffer. The items start at offset p,
847 * and they are item_size apart. There are 'max' items in p.
849 * the slot in the array is returned via slot, and it points to
850 * the place where you would insert key if it is not found in
853 * slot may point to max if the key is bigger than all of the keys
855 static noinline int generic_bin_search(struct extent_buffer *eb,
857 int item_size, struct btrfs_key *key,
864 struct btrfs_disk_key *tmp = NULL;
865 struct btrfs_disk_key unaligned;
866 unsigned long offset;
867 char *map_token = NULL;
869 unsigned long map_start = 0;
870 unsigned long map_len = 0;
874 mid = (low + high) / 2;
875 offset = p + mid * item_size;
877 if (!map_token || offset < map_start ||
878 (offset + sizeof(struct btrfs_disk_key)) >
879 map_start + map_len) {
881 unmap_extent_buffer(eb, map_token, KM_USER0);
885 err = map_private_extent_buffer(eb, offset,
886 sizeof(struct btrfs_disk_key),
888 &map_start, &map_len, KM_USER0);
891 tmp = (struct btrfs_disk_key *)(kaddr + offset -
894 read_extent_buffer(eb, &unaligned,
895 offset, sizeof(unaligned));
900 tmp = (struct btrfs_disk_key *)(kaddr + offset -
903 ret = comp_keys(tmp, key);
912 unmap_extent_buffer(eb, map_token, KM_USER0);
918 unmap_extent_buffer(eb, map_token, KM_USER0);
923 * simple bin_search frontend that does the right thing for
926 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
927 int level, int *slot)
930 return generic_bin_search(eb,
931 offsetof(struct btrfs_leaf, items),
932 sizeof(struct btrfs_item),
933 key, btrfs_header_nritems(eb),
936 return generic_bin_search(eb,
937 offsetof(struct btrfs_node, ptrs),
938 sizeof(struct btrfs_key_ptr),
939 key, btrfs_header_nritems(eb),
945 int btrfs_bin_search(struct extent_buffer *eb, struct btrfs_key *key,
946 int level, int *slot)
948 return bin_search(eb, key, level, slot);
951 /* given a node and slot number, this reads the blocks it points to. The
952 * extent buffer is returned with a reference taken (but unlocked).
953 * NULL is returned on error.
955 static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
956 struct extent_buffer *parent, int slot)
958 int level = btrfs_header_level(parent);
961 if (slot >= btrfs_header_nritems(parent))
966 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
967 btrfs_level_size(root, level - 1),
968 btrfs_node_ptr_generation(parent, slot));
972 * node level balancing, used to make sure nodes are in proper order for
973 * item deletion. We balance from the top down, so we have to make sure
974 * that a deletion won't leave an node completely empty later on.
976 static noinline int balance_level(struct btrfs_trans_handle *trans,
977 struct btrfs_root *root,
978 struct btrfs_path *path, int level)
980 struct extent_buffer *right = NULL;
981 struct extent_buffer *mid;
982 struct extent_buffer *left = NULL;
983 struct extent_buffer *parent = NULL;
987 int orig_slot = path->slots[level];
988 int err_on_enospc = 0;
994 mid = path->nodes[level];
996 WARN_ON(!path->locks[level]);
997 WARN_ON(btrfs_header_generation(mid) != trans->transid);
999 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1001 if (level < BTRFS_MAX_LEVEL - 1)
1002 parent = path->nodes[level + 1];
1003 pslot = path->slots[level + 1];
1006 * deal with the case where there is only one pointer in the root
1007 * by promoting the node below to a root
1010 struct extent_buffer *child;
1012 if (btrfs_header_nritems(mid) != 1)
1015 /* promote the child to a root */
1016 child = read_node_slot(root, mid, 0);
1018 btrfs_tree_lock(child);
1019 btrfs_set_lock_blocking(child);
1020 ret = btrfs_cow_block(trans, root, child, mid, 0, &child);
1023 spin_lock(&root->node_lock);
1025 spin_unlock(&root->node_lock);
1027 add_root_to_dirty_list(root);
1028 btrfs_tree_unlock(child);
1030 path->locks[level] = 0;
1031 path->nodes[level] = NULL;
1032 clean_tree_block(trans, root, mid);
1033 btrfs_tree_unlock(mid);
1034 /* once for the path */
1035 free_extent_buffer(mid);
1036 ret = btrfs_free_tree_block(trans, root, mid->start, mid->len,
1037 0, root->root_key.objectid, level);
1038 /* once for the root ptr */
1039 free_extent_buffer(mid);
1042 if (btrfs_header_nritems(mid) >
1043 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
1046 if (btrfs_header_nritems(mid) < 2)
1049 left = read_node_slot(root, parent, pslot - 1);
1051 btrfs_tree_lock(left);
1052 btrfs_set_lock_blocking(left);
1053 wret = btrfs_cow_block(trans, root, left,
1054 parent, pslot - 1, &left);
1060 right = read_node_slot(root, parent, pslot + 1);
1062 btrfs_tree_lock(right);
1063 btrfs_set_lock_blocking(right);
1064 wret = btrfs_cow_block(trans, root, right,
1065 parent, pslot + 1, &right);
1072 /* first, try to make some room in the middle buffer */
1074 orig_slot += btrfs_header_nritems(left);
1075 wret = push_node_left(trans, root, left, mid, 1);
1078 if (btrfs_header_nritems(mid) < 2)
1083 * then try to empty the right most buffer into the middle
1086 wret = push_node_left(trans, root, mid, right, 1);
1087 if (wret < 0 && wret != -ENOSPC)
1089 if (btrfs_header_nritems(right) == 0) {
1090 u64 bytenr = right->start;
1091 u32 blocksize = right->len;
1093 clean_tree_block(trans, root, right);
1094 btrfs_tree_unlock(right);
1095 free_extent_buffer(right);
1097 wret = del_ptr(trans, root, path, level + 1, pslot +
1101 wret = btrfs_free_tree_block(trans, root,
1102 bytenr, blocksize, 0,
1103 root->root_key.objectid,
1108 struct btrfs_disk_key right_key;
1109 btrfs_node_key(right, &right_key, 0);
1110 btrfs_set_node_key(parent, &right_key, pslot + 1);
1111 btrfs_mark_buffer_dirty(parent);
1114 if (btrfs_header_nritems(mid) == 1) {
1116 * we're not allowed to leave a node with one item in the
1117 * tree during a delete. A deletion from lower in the tree
1118 * could try to delete the only pointer in this node.
1119 * So, pull some keys from the left.
1120 * There has to be a left pointer at this point because
1121 * otherwise we would have pulled some pointers from the
1125 wret = balance_node_right(trans, root, mid, left);
1131 wret = push_node_left(trans, root, left, mid, 1);
1137 if (btrfs_header_nritems(mid) == 0) {
1138 /* we've managed to empty the middle node, drop it */
1139 u64 bytenr = mid->start;
1140 u32 blocksize = mid->len;
1142 clean_tree_block(trans, root, mid);
1143 btrfs_tree_unlock(mid);
1144 free_extent_buffer(mid);
1146 wret = del_ptr(trans, root, path, level + 1, pslot);
1149 wret = btrfs_free_tree_block(trans, root, bytenr, blocksize,
1150 0, root->root_key.objectid, level);
1154 /* update the parent key to reflect our changes */
1155 struct btrfs_disk_key mid_key;
1156 btrfs_node_key(mid, &mid_key, 0);
1157 btrfs_set_node_key(parent, &mid_key, pslot);
1158 btrfs_mark_buffer_dirty(parent);
1161 /* update the path */
1163 if (btrfs_header_nritems(left) > orig_slot) {
1164 extent_buffer_get(left);
1165 /* left was locked after cow */
1166 path->nodes[level] = left;
1167 path->slots[level + 1] -= 1;
1168 path->slots[level] = orig_slot;
1170 btrfs_tree_unlock(mid);
1171 free_extent_buffer(mid);
1174 orig_slot -= btrfs_header_nritems(left);
1175 path->slots[level] = orig_slot;
1178 /* double check we haven't messed things up */
1179 check_block(root, path, level);
1181 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
1185 btrfs_tree_unlock(right);
1186 free_extent_buffer(right);
1189 if (path->nodes[level] != left)
1190 btrfs_tree_unlock(left);
1191 free_extent_buffer(left);
1196 /* Node balancing for insertion. Here we only split or push nodes around
1197 * when they are completely full. This is also done top down, so we
1198 * have to be pessimistic.
1200 static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
1201 struct btrfs_root *root,
1202 struct btrfs_path *path, int level)
1204 struct extent_buffer *right = NULL;
1205 struct extent_buffer *mid;
1206 struct extent_buffer *left = NULL;
1207 struct extent_buffer *parent = NULL;
1211 int orig_slot = path->slots[level];
1217 mid = path->nodes[level];
1218 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1219 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1221 if (level < BTRFS_MAX_LEVEL - 1)
1222 parent = path->nodes[level + 1];
1223 pslot = path->slots[level + 1];
1228 left = read_node_slot(root, parent, pslot - 1);
1230 /* first, try to make some room in the middle buffer */
1234 btrfs_tree_lock(left);
1235 btrfs_set_lock_blocking(left);
1237 left_nr = btrfs_header_nritems(left);
1238 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1241 ret = btrfs_cow_block(trans, root, left, parent,
1246 wret = push_node_left(trans, root,
1253 struct btrfs_disk_key disk_key;
1254 orig_slot += left_nr;
1255 btrfs_node_key(mid, &disk_key, 0);
1256 btrfs_set_node_key(parent, &disk_key, pslot);
1257 btrfs_mark_buffer_dirty(parent);
1258 if (btrfs_header_nritems(left) > orig_slot) {
1259 path->nodes[level] = left;
1260 path->slots[level + 1] -= 1;
1261 path->slots[level] = orig_slot;
1262 btrfs_tree_unlock(mid);
1263 free_extent_buffer(mid);
1266 btrfs_header_nritems(left);
1267 path->slots[level] = orig_slot;
1268 btrfs_tree_unlock(left);
1269 free_extent_buffer(left);
1273 btrfs_tree_unlock(left);
1274 free_extent_buffer(left);
1276 right = read_node_slot(root, parent, pslot + 1);
1279 * then try to empty the right most buffer into the middle
1284 btrfs_tree_lock(right);
1285 btrfs_set_lock_blocking(right);
1287 right_nr = btrfs_header_nritems(right);
1288 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1291 ret = btrfs_cow_block(trans, root, right,
1297 wret = balance_node_right(trans, root,
1304 struct btrfs_disk_key disk_key;
1306 btrfs_node_key(right, &disk_key, 0);
1307 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1308 btrfs_mark_buffer_dirty(parent);
1310 if (btrfs_header_nritems(mid) <= orig_slot) {
1311 path->nodes[level] = right;
1312 path->slots[level + 1] += 1;
1313 path->slots[level] = orig_slot -
1314 btrfs_header_nritems(mid);
1315 btrfs_tree_unlock(mid);
1316 free_extent_buffer(mid);
1318 btrfs_tree_unlock(right);
1319 free_extent_buffer(right);
1323 btrfs_tree_unlock(right);
1324 free_extent_buffer(right);
1330 * readahead one full node of leaves, finding things that are close
1331 * to the block in 'slot', and triggering ra on them.
1333 static void reada_for_search(struct btrfs_root *root,
1334 struct btrfs_path *path,
1335 int level, int slot, u64 objectid)
1337 struct extent_buffer *node;
1338 struct btrfs_disk_key disk_key;
1343 int direction = path->reada;
1344 struct extent_buffer *eb;
1352 if (!path->nodes[level])
1355 node = path->nodes[level];
1357 search = btrfs_node_blockptr(node, slot);
1358 blocksize = btrfs_level_size(root, level - 1);
1359 eb = btrfs_find_tree_block(root, search, blocksize);
1361 free_extent_buffer(eb);
1367 nritems = btrfs_header_nritems(node);
1370 if (direction < 0) {
1374 } else if (direction > 0) {
1379 if (path->reada < 0 && objectid) {
1380 btrfs_node_key(node, &disk_key, nr);
1381 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1384 search = btrfs_node_blockptr(node, nr);
1385 if ((search <= target && target - search <= 65536) ||
1386 (search > target && search - target <= 65536)) {
1387 readahead_tree_block(root, search, blocksize,
1388 btrfs_node_ptr_generation(node, nr));
1392 if ((nread > 65536 || nscan > 32))
1398 * returns -EAGAIN if it had to drop the path, or zero if everything was in
1401 static noinline int reada_for_balance(struct btrfs_root *root,
1402 struct btrfs_path *path, int level)
1406 struct extent_buffer *parent;
1407 struct extent_buffer *eb;
1414 parent = path->nodes[level + 1];
1418 nritems = btrfs_header_nritems(parent);
1419 slot = path->slots[level + 1];
1420 blocksize = btrfs_level_size(root, level);
1423 block1 = btrfs_node_blockptr(parent, slot - 1);
1424 gen = btrfs_node_ptr_generation(parent, slot - 1);
1425 eb = btrfs_find_tree_block(root, block1, blocksize);
1426 if (eb && btrfs_buffer_uptodate(eb, gen))
1428 free_extent_buffer(eb);
1430 if (slot + 1 < nritems) {
1431 block2 = btrfs_node_blockptr(parent, slot + 1);
1432 gen = btrfs_node_ptr_generation(parent, slot + 1);
1433 eb = btrfs_find_tree_block(root, block2, blocksize);
1434 if (eb && btrfs_buffer_uptodate(eb, gen))
1436 free_extent_buffer(eb);
1438 if (block1 || block2) {
1441 /* release the whole path */
1442 btrfs_release_path(root, path);
1444 /* read the blocks */
1446 readahead_tree_block(root, block1, blocksize, 0);
1448 readahead_tree_block(root, block2, blocksize, 0);
1451 eb = read_tree_block(root, block1, blocksize, 0);
1452 free_extent_buffer(eb);
1455 eb = read_tree_block(root, block2, blocksize, 0);
1456 free_extent_buffer(eb);
1464 * when we walk down the tree, it is usually safe to unlock the higher layers
1465 * in the tree. The exceptions are when our path goes through slot 0, because
1466 * operations on the tree might require changing key pointers higher up in the
1469 * callers might also have set path->keep_locks, which tells this code to keep
1470 * the lock if the path points to the last slot in the block. This is part of
1471 * walking through the tree, and selecting the next slot in the higher block.
1473 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
1474 * if lowest_unlock is 1, level 0 won't be unlocked
1476 static noinline void unlock_up(struct btrfs_path *path, int level,
1480 int skip_level = level;
1482 struct extent_buffer *t;
1484 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1485 if (!path->nodes[i])
1487 if (!path->locks[i])
1489 if (!no_skips && path->slots[i] == 0) {
1493 if (!no_skips && path->keep_locks) {
1496 nritems = btrfs_header_nritems(t);
1497 if (nritems < 1 || path->slots[i] >= nritems - 1) {
1502 if (skip_level < i && i >= lowest_unlock)
1506 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1507 btrfs_tree_unlock(t);
1514 * This releases any locks held in the path starting at level and
1515 * going all the way up to the root.
1517 * btrfs_search_slot will keep the lock held on higher nodes in a few
1518 * corner cases, such as COW of the block at slot zero in the node. This
1519 * ignores those rules, and it should only be called when there are no
1520 * more updates to be done higher up in the tree.
1522 noinline void btrfs_unlock_up_safe(struct btrfs_path *path, int level)
1526 if (path->keep_locks)
1529 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1530 if (!path->nodes[i])
1532 if (!path->locks[i])
1534 btrfs_tree_unlock(path->nodes[i]);
1540 * helper function for btrfs_search_slot. The goal is to find a block
1541 * in cache without setting the path to blocking. If we find the block
1542 * we return zero and the path is unchanged.
1544 * If we can't find the block, we set the path blocking and do some
1545 * reada. -EAGAIN is returned and the search must be repeated.
1548 read_block_for_search(struct btrfs_trans_handle *trans,
1549 struct btrfs_root *root, struct btrfs_path *p,
1550 struct extent_buffer **eb_ret, int level, int slot,
1551 struct btrfs_key *key)
1556 struct extent_buffer *b = *eb_ret;
1557 struct extent_buffer *tmp;
1560 blocknr = btrfs_node_blockptr(b, slot);
1561 gen = btrfs_node_ptr_generation(b, slot);
1562 blocksize = btrfs_level_size(root, level - 1);
1564 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1565 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
1567 * we found an up to date block without sleeping, return
1575 * reduce lock contention at high levels
1576 * of the btree by dropping locks before
1577 * we read. Don't release the lock on the current
1578 * level because we need to walk this node to figure
1579 * out which blocks to read.
1581 btrfs_unlock_up_safe(p, level + 1);
1582 btrfs_set_path_blocking(p);
1585 free_extent_buffer(tmp);
1587 reada_for_search(root, p, level, slot, key->objectid);
1589 btrfs_release_path(NULL, p);
1592 tmp = read_tree_block(root, blocknr, blocksize, gen);
1595 * If the read above didn't mark this buffer up to date,
1596 * it will never end up being up to date. Set ret to EIO now
1597 * and give up so that our caller doesn't loop forever
1600 if (!btrfs_buffer_uptodate(tmp, 0))
1602 free_extent_buffer(tmp);
1608 * helper function for btrfs_search_slot. This does all of the checks
1609 * for node-level blocks and does any balancing required based on
1612 * If no extra work was required, zero is returned. If we had to
1613 * drop the path, -EAGAIN is returned and btrfs_search_slot must
1617 setup_nodes_for_search(struct btrfs_trans_handle *trans,
1618 struct btrfs_root *root, struct btrfs_path *p,
1619 struct extent_buffer *b, int level, int ins_len)
1622 if ((p->search_for_split || ins_len > 0) && btrfs_header_nritems(b) >=
1623 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1626 sret = reada_for_balance(root, p, level);
1630 btrfs_set_path_blocking(p);
1631 sret = split_node(trans, root, p, level);
1632 btrfs_clear_path_blocking(p, NULL);
1639 b = p->nodes[level];
1640 } else if (ins_len < 0 && btrfs_header_nritems(b) <
1641 BTRFS_NODEPTRS_PER_BLOCK(root) / 2) {
1644 sret = reada_for_balance(root, p, level);
1648 btrfs_set_path_blocking(p);
1649 sret = balance_level(trans, root, p, level);
1650 btrfs_clear_path_blocking(p, NULL);
1656 b = p->nodes[level];
1658 btrfs_release_path(NULL, p);
1661 BUG_ON(btrfs_header_nritems(b) == 1);
1672 * look for key in the tree. path is filled in with nodes along the way
1673 * if key is found, we return zero and you can find the item in the leaf
1674 * level of the path (level 0)
1676 * If the key isn't found, the path points to the slot where it should
1677 * be inserted, and 1 is returned. If there are other errors during the
1678 * search a negative error number is returned.
1680 * if ins_len > 0, nodes and leaves will be split as we walk down the
1681 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1684 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1685 *root, struct btrfs_key *key, struct btrfs_path *p, int
1688 struct extent_buffer *b;
1693 int lowest_unlock = 1;
1694 u8 lowest_level = 0;
1696 lowest_level = p->lowest_level;
1697 WARN_ON(lowest_level && ins_len > 0);
1698 WARN_ON(p->nodes[0] != NULL);
1704 if (p->search_commit_root) {
1705 b = root->commit_root;
1706 extent_buffer_get(b);
1707 if (!p->skip_locking)
1710 if (p->skip_locking)
1711 b = btrfs_root_node(root);
1713 b = btrfs_lock_root_node(root);
1717 level = btrfs_header_level(b);
1720 * setup the path here so we can release it under lock
1721 * contention with the cow code
1723 p->nodes[level] = b;
1724 if (!p->skip_locking)
1725 p->locks[level] = 1;
1729 * if we don't really need to cow this block
1730 * then we don't want to set the path blocking,
1731 * so we test it here
1733 if (!should_cow_block(trans, root, b))
1736 btrfs_set_path_blocking(p);
1738 err = btrfs_cow_block(trans, root, b,
1739 p->nodes[level + 1],
1740 p->slots[level + 1], &b);
1742 free_extent_buffer(b);
1748 BUG_ON(!cow && ins_len);
1749 if (level != btrfs_header_level(b))
1751 level = btrfs_header_level(b);
1753 p->nodes[level] = b;
1754 if (!p->skip_locking)
1755 p->locks[level] = 1;
1757 btrfs_clear_path_blocking(p, NULL);
1760 * we have a lock on b and as long as we aren't changing
1761 * the tree, there is no way to for the items in b to change.
1762 * It is safe to drop the lock on our parent before we
1763 * go through the expensive btree search on b.
1765 * If cow is true, then we might be changing slot zero,
1766 * which may require changing the parent. So, we can't
1767 * drop the lock until after we know which slot we're
1771 btrfs_unlock_up_safe(p, level + 1);
1773 ret = check_block(root, p, level);
1779 ret = bin_search(b, key, level, &slot);
1783 if (ret && slot > 0) {
1787 p->slots[level] = slot;
1788 err = setup_nodes_for_search(trans, root, p, b, level,
1796 b = p->nodes[level];
1797 slot = p->slots[level];
1799 unlock_up(p, level, lowest_unlock);
1801 if (level == lowest_level) {
1807 err = read_block_for_search(trans, root, p,
1808 &b, level, slot, key);
1816 if (!p->skip_locking) {
1817 btrfs_clear_path_blocking(p, NULL);
1818 err = btrfs_try_spin_lock(b);
1821 btrfs_set_path_blocking(p);
1823 btrfs_clear_path_blocking(p, b);
1827 p->slots[level] = slot;
1829 btrfs_leaf_free_space(root, b) < ins_len) {
1830 btrfs_set_path_blocking(p);
1831 err = split_leaf(trans, root, key,
1832 p, ins_len, ret == 0);
1833 btrfs_clear_path_blocking(p, NULL);
1841 if (!p->search_for_split)
1842 unlock_up(p, level, lowest_unlock);
1849 * we don't really know what they plan on doing with the path
1850 * from here on, so for now just mark it as blocking
1852 if (!p->leave_spinning)
1853 btrfs_set_path_blocking(p);
1855 btrfs_release_path(root, p);
1860 * adjust the pointers going up the tree, starting at level
1861 * making sure the right key of each node is points to 'key'.
1862 * This is used after shifting pointers to the left, so it stops
1863 * fixing up pointers when a given leaf/node is not in slot 0 of the
1866 * If this fails to write a tree block, it returns -1, but continues
1867 * fixing up the blocks in ram so the tree is consistent.
1869 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1870 struct btrfs_root *root, struct btrfs_path *path,
1871 struct btrfs_disk_key *key, int level)
1875 struct extent_buffer *t;
1877 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1878 int tslot = path->slots[i];
1879 if (!path->nodes[i])
1882 btrfs_set_node_key(t, key, tslot);
1883 btrfs_mark_buffer_dirty(path->nodes[i]);
1893 * This function isn't completely safe. It's the caller's responsibility
1894 * that the new key won't break the order
1896 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1897 struct btrfs_root *root, struct btrfs_path *path,
1898 struct btrfs_key *new_key)
1900 struct btrfs_disk_key disk_key;
1901 struct extent_buffer *eb;
1904 eb = path->nodes[0];
1905 slot = path->slots[0];
1907 btrfs_item_key(eb, &disk_key, slot - 1);
1908 if (comp_keys(&disk_key, new_key) >= 0)
1911 if (slot < btrfs_header_nritems(eb) - 1) {
1912 btrfs_item_key(eb, &disk_key, slot + 1);
1913 if (comp_keys(&disk_key, new_key) <= 0)
1917 btrfs_cpu_key_to_disk(&disk_key, new_key);
1918 btrfs_set_item_key(eb, &disk_key, slot);
1919 btrfs_mark_buffer_dirty(eb);
1921 fixup_low_keys(trans, root, path, &disk_key, 1);
1926 * try to push data from one node into the next node left in the
1929 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1930 * error, and > 0 if there was no room in the left hand block.
1932 static int push_node_left(struct btrfs_trans_handle *trans,
1933 struct btrfs_root *root, struct extent_buffer *dst,
1934 struct extent_buffer *src, int empty)
1941 src_nritems = btrfs_header_nritems(src);
1942 dst_nritems = btrfs_header_nritems(dst);
1943 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1944 WARN_ON(btrfs_header_generation(src) != trans->transid);
1945 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1947 if (!empty && src_nritems <= 8)
1950 if (push_items <= 0)
1954 push_items = min(src_nritems, push_items);
1955 if (push_items < src_nritems) {
1956 /* leave at least 8 pointers in the node if
1957 * we aren't going to empty it
1959 if (src_nritems - push_items < 8) {
1960 if (push_items <= 8)
1966 push_items = min(src_nritems - 8, push_items);
1968 copy_extent_buffer(dst, src,
1969 btrfs_node_key_ptr_offset(dst_nritems),
1970 btrfs_node_key_ptr_offset(0),
1971 push_items * sizeof(struct btrfs_key_ptr));
1973 if (push_items < src_nritems) {
1974 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1975 btrfs_node_key_ptr_offset(push_items),
1976 (src_nritems - push_items) *
1977 sizeof(struct btrfs_key_ptr));
1979 btrfs_set_header_nritems(src, src_nritems - push_items);
1980 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1981 btrfs_mark_buffer_dirty(src);
1982 btrfs_mark_buffer_dirty(dst);
1988 * try to push data from one node into the next node right in the
1991 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1992 * error, and > 0 if there was no room in the right hand block.
1994 * this will only push up to 1/2 the contents of the left node over
1996 static int balance_node_right(struct btrfs_trans_handle *trans,
1997 struct btrfs_root *root,
1998 struct extent_buffer *dst,
1999 struct extent_buffer *src)
2007 WARN_ON(btrfs_header_generation(src) != trans->transid);
2008 WARN_ON(btrfs_header_generation(dst) != trans->transid);
2010 src_nritems = btrfs_header_nritems(src);
2011 dst_nritems = btrfs_header_nritems(dst);
2012 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
2013 if (push_items <= 0)
2016 if (src_nritems < 4)
2019 max_push = src_nritems / 2 + 1;
2020 /* don't try to empty the node */
2021 if (max_push >= src_nritems)
2024 if (max_push < push_items)
2025 push_items = max_push;
2027 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
2028 btrfs_node_key_ptr_offset(0),
2030 sizeof(struct btrfs_key_ptr));
2032 copy_extent_buffer(dst, src,
2033 btrfs_node_key_ptr_offset(0),
2034 btrfs_node_key_ptr_offset(src_nritems - push_items),
2035 push_items * sizeof(struct btrfs_key_ptr));
2037 btrfs_set_header_nritems(src, src_nritems - push_items);
2038 btrfs_set_header_nritems(dst, dst_nritems + push_items);
2040 btrfs_mark_buffer_dirty(src);
2041 btrfs_mark_buffer_dirty(dst);
2047 * helper function to insert a new root level in the tree.
2048 * A new node is allocated, and a single item is inserted to
2049 * point to the existing root
2051 * returns zero on success or < 0 on failure.
2053 static noinline int insert_new_root(struct btrfs_trans_handle *trans,
2054 struct btrfs_root *root,
2055 struct btrfs_path *path, int level)
2058 struct extent_buffer *lower;
2059 struct extent_buffer *c;
2060 struct extent_buffer *old;
2061 struct btrfs_disk_key lower_key;
2063 BUG_ON(path->nodes[level]);
2064 BUG_ON(path->nodes[level-1] != root->node);
2066 lower = path->nodes[level-1];
2068 btrfs_item_key(lower, &lower_key, 0);
2070 btrfs_node_key(lower, &lower_key, 0);
2072 c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
2073 root->root_key.objectid, &lower_key,
2074 level, root->node->start, 0);
2078 memset_extent_buffer(c, 0, 0, sizeof(struct btrfs_header));
2079 btrfs_set_header_nritems(c, 1);
2080 btrfs_set_header_level(c, level);
2081 btrfs_set_header_bytenr(c, c->start);
2082 btrfs_set_header_generation(c, trans->transid);
2083 btrfs_set_header_backref_rev(c, BTRFS_MIXED_BACKREF_REV);
2084 btrfs_set_header_owner(c, root->root_key.objectid);
2086 write_extent_buffer(c, root->fs_info->fsid,
2087 (unsigned long)btrfs_header_fsid(c),
2090 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
2091 (unsigned long)btrfs_header_chunk_tree_uuid(c),
2094 btrfs_set_node_key(c, &lower_key, 0);
2095 btrfs_set_node_blockptr(c, 0, lower->start);
2096 lower_gen = btrfs_header_generation(lower);
2097 WARN_ON(lower_gen != trans->transid);
2099 btrfs_set_node_ptr_generation(c, 0, lower_gen);
2101 btrfs_mark_buffer_dirty(c);
2103 spin_lock(&root->node_lock);
2106 spin_unlock(&root->node_lock);
2108 /* the super has an extra ref to root->node */
2109 free_extent_buffer(old);
2111 add_root_to_dirty_list(root);
2112 extent_buffer_get(c);
2113 path->nodes[level] = c;
2114 path->locks[level] = 1;
2115 path->slots[level] = 0;
2120 * worker function to insert a single pointer in a node.
2121 * the node should have enough room for the pointer already
2123 * slot and level indicate where you want the key to go, and
2124 * blocknr is the block the key points to.
2126 * returns zero on success and < 0 on any error
2128 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
2129 *root, struct btrfs_path *path, struct btrfs_disk_key
2130 *key, u64 bytenr, int slot, int level)
2132 struct extent_buffer *lower;
2135 BUG_ON(!path->nodes[level]);
2136 lower = path->nodes[level];
2137 nritems = btrfs_header_nritems(lower);
2138 BUG_ON(slot > nritems);
2139 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
2141 if (slot != nritems) {
2142 memmove_extent_buffer(lower,
2143 btrfs_node_key_ptr_offset(slot + 1),
2144 btrfs_node_key_ptr_offset(slot),
2145 (nritems - slot) * sizeof(struct btrfs_key_ptr));
2147 btrfs_set_node_key(lower, key, slot);
2148 btrfs_set_node_blockptr(lower, slot, bytenr);
2149 WARN_ON(trans->transid == 0);
2150 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
2151 btrfs_set_header_nritems(lower, nritems + 1);
2152 btrfs_mark_buffer_dirty(lower);
2157 * split the node at the specified level in path in two.
2158 * The path is corrected to point to the appropriate node after the split
2160 * Before splitting this tries to make some room in the node by pushing
2161 * left and right, if either one works, it returns right away.
2163 * returns 0 on success and < 0 on failure
2165 static noinline int split_node(struct btrfs_trans_handle *trans,
2166 struct btrfs_root *root,
2167 struct btrfs_path *path, int level)
2169 struct extent_buffer *c;
2170 struct extent_buffer *split;
2171 struct btrfs_disk_key disk_key;
2177 c = path->nodes[level];
2178 WARN_ON(btrfs_header_generation(c) != trans->transid);
2179 if (c == root->node) {
2180 /* trying to split the root, lets make a new one */
2181 ret = insert_new_root(trans, root, path, level + 1);
2185 ret = push_nodes_for_insert(trans, root, path, level);
2186 c = path->nodes[level];
2187 if (!ret && btrfs_header_nritems(c) <
2188 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
2194 c_nritems = btrfs_header_nritems(c);
2195 mid = (c_nritems + 1) / 2;
2196 btrfs_node_key(c, &disk_key, mid);
2198 split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
2199 root->root_key.objectid,
2200 &disk_key, level, c->start, 0);
2202 return PTR_ERR(split);
2204 memset_extent_buffer(split, 0, 0, sizeof(struct btrfs_header));
2205 btrfs_set_header_level(split, btrfs_header_level(c));
2206 btrfs_set_header_bytenr(split, split->start);
2207 btrfs_set_header_generation(split, trans->transid);
2208 btrfs_set_header_backref_rev(split, BTRFS_MIXED_BACKREF_REV);
2209 btrfs_set_header_owner(split, root->root_key.objectid);
2210 write_extent_buffer(split, root->fs_info->fsid,
2211 (unsigned long)btrfs_header_fsid(split),
2213 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
2214 (unsigned long)btrfs_header_chunk_tree_uuid(split),
2218 copy_extent_buffer(split, c,
2219 btrfs_node_key_ptr_offset(0),
2220 btrfs_node_key_ptr_offset(mid),
2221 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
2222 btrfs_set_header_nritems(split, c_nritems - mid);
2223 btrfs_set_header_nritems(c, mid);
2226 btrfs_mark_buffer_dirty(c);
2227 btrfs_mark_buffer_dirty(split);
2229 wret = insert_ptr(trans, root, path, &disk_key, split->start,
2230 path->slots[level + 1] + 1,
2235 if (path->slots[level] >= mid) {
2236 path->slots[level] -= mid;
2237 btrfs_tree_unlock(c);
2238 free_extent_buffer(c);
2239 path->nodes[level] = split;
2240 path->slots[level + 1] += 1;
2242 btrfs_tree_unlock(split);
2243 free_extent_buffer(split);
2249 * how many bytes are required to store the items in a leaf. start
2250 * and nr indicate which items in the leaf to check. This totals up the
2251 * space used both by the item structs and the item data
2253 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
2256 int nritems = btrfs_header_nritems(l);
2257 int end = min(nritems, start + nr) - 1;
2261 data_len = btrfs_item_end_nr(l, start);
2262 data_len = data_len - btrfs_item_offset_nr(l, end);
2263 data_len += sizeof(struct btrfs_item) * nr;
2264 WARN_ON(data_len < 0);
2269 * The space between the end of the leaf items and
2270 * the start of the leaf data. IOW, how much room
2271 * the leaf has left for both items and data
2273 noinline int btrfs_leaf_free_space(struct btrfs_root *root,
2274 struct extent_buffer *leaf)
2276 int nritems = btrfs_header_nritems(leaf);
2278 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
2280 printk(KERN_CRIT "leaf free space ret %d, leaf data size %lu, "
2281 "used %d nritems %d\n",
2282 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
2283 leaf_space_used(leaf, 0, nritems), nritems);
2288 static noinline int __push_leaf_right(struct btrfs_trans_handle *trans,
2289 struct btrfs_root *root,
2290 struct btrfs_path *path,
2291 int data_size, int empty,
2292 struct extent_buffer *right,
2293 int free_space, u32 left_nritems)
2295 struct extent_buffer *left = path->nodes[0];
2296 struct extent_buffer *upper = path->nodes[1];
2297 struct btrfs_disk_key disk_key;
2302 struct btrfs_item *item;
2313 if (path->slots[0] >= left_nritems)
2314 push_space += data_size;
2316 slot = path->slots[1];
2317 i = left_nritems - 1;
2319 item = btrfs_item_nr(left, i);
2321 if (!empty && push_items > 0) {
2322 if (path->slots[0] > i)
2324 if (path->slots[0] == i) {
2325 int space = btrfs_leaf_free_space(root, left);
2326 if (space + push_space * 2 > free_space)
2331 if (path->slots[0] == i)
2332 push_space += data_size;
2334 if (!left->map_token) {
2335 map_extent_buffer(left, (unsigned long)item,
2336 sizeof(struct btrfs_item),
2337 &left->map_token, &left->kaddr,
2338 &left->map_start, &left->map_len,
2342 this_item_size = btrfs_item_size(left, item);
2343 if (this_item_size + sizeof(*item) + push_space > free_space)
2347 push_space += this_item_size + sizeof(*item);
2352 if (left->map_token) {
2353 unmap_extent_buffer(left, left->map_token, KM_USER1);
2354 left->map_token = NULL;
2357 if (push_items == 0)
2360 if (!empty && push_items == left_nritems)
2363 /* push left to right */
2364 right_nritems = btrfs_header_nritems(right);
2366 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
2367 push_space -= leaf_data_end(root, left);
2369 /* make room in the right data area */
2370 data_end = leaf_data_end(root, right);
2371 memmove_extent_buffer(right,
2372 btrfs_leaf_data(right) + data_end - push_space,
2373 btrfs_leaf_data(right) + data_end,
2374 BTRFS_LEAF_DATA_SIZE(root) - data_end);
2376 /* copy from the left data area */
2377 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
2378 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2379 btrfs_leaf_data(left) + leaf_data_end(root, left),
2382 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
2383 btrfs_item_nr_offset(0),
2384 right_nritems * sizeof(struct btrfs_item));
2386 /* copy the items from left to right */
2387 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
2388 btrfs_item_nr_offset(left_nritems - push_items),
2389 push_items * sizeof(struct btrfs_item));
2391 /* update the item pointers */
2392 right_nritems += push_items;
2393 btrfs_set_header_nritems(right, right_nritems);
2394 push_space = BTRFS_LEAF_DATA_SIZE(root);
2395 for (i = 0; i < right_nritems; i++) {
2396 item = btrfs_item_nr(right, i);
2397 if (!right->map_token) {
2398 map_extent_buffer(right, (unsigned long)item,
2399 sizeof(struct btrfs_item),
2400 &right->map_token, &right->kaddr,
2401 &right->map_start, &right->map_len,
2404 push_space -= btrfs_item_size(right, item);
2405 btrfs_set_item_offset(right, item, push_space);
2408 if (right->map_token) {
2409 unmap_extent_buffer(right, right->map_token, KM_USER1);
2410 right->map_token = NULL;
2412 left_nritems -= push_items;
2413 btrfs_set_header_nritems(left, left_nritems);
2416 btrfs_mark_buffer_dirty(left);
2417 btrfs_mark_buffer_dirty(right);
2419 btrfs_item_key(right, &disk_key, 0);
2420 btrfs_set_node_key(upper, &disk_key, slot + 1);
2421 btrfs_mark_buffer_dirty(upper);
2423 /* then fixup the leaf pointer in the path */
2424 if (path->slots[0] >= left_nritems) {
2425 path->slots[0] -= left_nritems;
2426 if (btrfs_header_nritems(path->nodes[0]) == 0)
2427 clean_tree_block(trans, root, path->nodes[0]);
2428 btrfs_tree_unlock(path->nodes[0]);
2429 free_extent_buffer(path->nodes[0]);
2430 path->nodes[0] = right;
2431 path->slots[1] += 1;
2433 btrfs_tree_unlock(right);
2434 free_extent_buffer(right);
2439 btrfs_tree_unlock(right);
2440 free_extent_buffer(right);
2445 * push some data in the path leaf to the right, trying to free up at
2446 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2448 * returns 1 if the push failed because the other node didn't have enough
2449 * room, 0 if everything worked out and < 0 if there were major errors.
2451 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
2452 *root, struct btrfs_path *path, int data_size,
2455 struct extent_buffer *left = path->nodes[0];
2456 struct extent_buffer *right;
2457 struct extent_buffer *upper;
2463 if (!path->nodes[1])
2466 slot = path->slots[1];
2467 upper = path->nodes[1];
2468 if (slot >= btrfs_header_nritems(upper) - 1)
2471 btrfs_assert_tree_locked(path->nodes[1]);
2473 right = read_node_slot(root, upper, slot + 1);
2474 btrfs_tree_lock(right);
2475 btrfs_set_lock_blocking(right);
2477 free_space = btrfs_leaf_free_space(root, right);
2478 if (free_space < data_size)
2481 /* cow and double check */
2482 ret = btrfs_cow_block(trans, root, right, upper,
2487 free_space = btrfs_leaf_free_space(root, right);
2488 if (free_space < data_size)
2491 left_nritems = btrfs_header_nritems(left);
2492 if (left_nritems == 0)
2495 return __push_leaf_right(trans, root, path, data_size, empty,
2496 right, free_space, left_nritems);
2498 btrfs_tree_unlock(right);
2499 free_extent_buffer(right);
2504 * push some data in the path leaf to the left, trying to free up at
2505 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2507 static noinline int __push_leaf_left(struct btrfs_trans_handle *trans,
2508 struct btrfs_root *root,
2509 struct btrfs_path *path, int data_size,
2510 int empty, struct extent_buffer *left,
2511 int free_space, int right_nritems)
2513 struct btrfs_disk_key disk_key;
2514 struct extent_buffer *right = path->nodes[0];
2519 struct btrfs_item *item;
2520 u32 old_left_nritems;
2525 u32 old_left_item_size;
2527 slot = path->slots[1];
2532 nr = right_nritems - 1;
2534 for (i = 0; i < nr; i++) {
2535 item = btrfs_item_nr(right, i);
2536 if (!right->map_token) {
2537 map_extent_buffer(right, (unsigned long)item,
2538 sizeof(struct btrfs_item),
2539 &right->map_token, &right->kaddr,
2540 &right->map_start, &right->map_len,
2544 if (!empty && push_items > 0) {
2545 if (path->slots[0] < i)
2547 if (path->slots[0] == i) {
2548 int space = btrfs_leaf_free_space(root, right);
2549 if (space + push_space * 2 > free_space)
2554 if (path->slots[0] == i)
2555 push_space += data_size;
2557 this_item_size = btrfs_item_size(right, item);
2558 if (this_item_size + sizeof(*item) + push_space > free_space)
2562 push_space += this_item_size + sizeof(*item);
2565 if (right->map_token) {
2566 unmap_extent_buffer(right, right->map_token, KM_USER1);
2567 right->map_token = NULL;
2570 if (push_items == 0) {
2574 if (!empty && push_items == btrfs_header_nritems(right))
2577 /* push data from right to left */
2578 copy_extent_buffer(left, right,
2579 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2580 btrfs_item_nr_offset(0),
2581 push_items * sizeof(struct btrfs_item));
2583 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2584 btrfs_item_offset_nr(right, push_items - 1);
2586 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2587 leaf_data_end(root, left) - push_space,
2588 btrfs_leaf_data(right) +
2589 btrfs_item_offset_nr(right, push_items - 1),
2591 old_left_nritems = btrfs_header_nritems(left);
2592 BUG_ON(old_left_nritems <= 0);
2594 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2595 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2598 item = btrfs_item_nr(left, i);
2599 if (!left->map_token) {
2600 map_extent_buffer(left, (unsigned long)item,
2601 sizeof(struct btrfs_item),
2602 &left->map_token, &left->kaddr,
2603 &left->map_start, &left->map_len,
2607 ioff = btrfs_item_offset(left, item);
2608 btrfs_set_item_offset(left, item,
2609 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2611 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2612 if (left->map_token) {
2613 unmap_extent_buffer(left, left->map_token, KM_USER1);
2614 left->map_token = NULL;
2617 /* fixup right node */
2618 if (push_items > right_nritems) {
2619 printk(KERN_CRIT "push items %d nr %u\n", push_items,
2624 if (push_items < right_nritems) {
2625 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2626 leaf_data_end(root, right);
2627 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2628 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2629 btrfs_leaf_data(right) +
2630 leaf_data_end(root, right), push_space);
2632 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2633 btrfs_item_nr_offset(push_items),
2634 (btrfs_header_nritems(right) - push_items) *
2635 sizeof(struct btrfs_item));
2637 right_nritems -= push_items;
2638 btrfs_set_header_nritems(right, right_nritems);
2639 push_space = BTRFS_LEAF_DATA_SIZE(root);
2640 for (i = 0; i < right_nritems; i++) {
2641 item = btrfs_item_nr(right, i);
2643 if (!right->map_token) {
2644 map_extent_buffer(right, (unsigned long)item,
2645 sizeof(struct btrfs_item),
2646 &right->map_token, &right->kaddr,
2647 &right->map_start, &right->map_len,
2651 push_space = push_space - btrfs_item_size(right, item);
2652 btrfs_set_item_offset(right, item, push_space);
2654 if (right->map_token) {
2655 unmap_extent_buffer(right, right->map_token, KM_USER1);
2656 right->map_token = NULL;
2659 btrfs_mark_buffer_dirty(left);
2661 btrfs_mark_buffer_dirty(right);
2663 btrfs_item_key(right, &disk_key, 0);
2664 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2668 /* then fixup the leaf pointer in the path */
2669 if (path->slots[0] < push_items) {
2670 path->slots[0] += old_left_nritems;
2671 if (btrfs_header_nritems(path->nodes[0]) == 0)
2672 clean_tree_block(trans, root, path->nodes[0]);
2673 btrfs_tree_unlock(path->nodes[0]);
2674 free_extent_buffer(path->nodes[0]);
2675 path->nodes[0] = left;
2676 path->slots[1] -= 1;
2678 btrfs_tree_unlock(left);
2679 free_extent_buffer(left);
2680 path->slots[0] -= push_items;
2682 BUG_ON(path->slots[0] < 0);
2685 btrfs_tree_unlock(left);
2686 free_extent_buffer(left);
2691 * push some data in the path leaf to the left, trying to free up at
2692 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2694 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
2695 *root, struct btrfs_path *path, int data_size,
2698 struct extent_buffer *right = path->nodes[0];
2699 struct extent_buffer *left;
2705 slot = path->slots[1];
2708 if (!path->nodes[1])
2711 right_nritems = btrfs_header_nritems(right);
2712 if (right_nritems == 0)
2715 btrfs_assert_tree_locked(path->nodes[1]);
2717 left = read_node_slot(root, path->nodes[1], slot - 1);
2718 btrfs_tree_lock(left);
2719 btrfs_set_lock_blocking(left);
2721 free_space = btrfs_leaf_free_space(root, left);
2722 if (free_space < data_size) {
2727 /* cow and double check */
2728 ret = btrfs_cow_block(trans, root, left,
2729 path->nodes[1], slot - 1, &left);
2731 /* we hit -ENOSPC, but it isn't fatal here */
2736 free_space = btrfs_leaf_free_space(root, left);
2737 if (free_space < data_size) {
2742 return __push_leaf_left(trans, root, path, data_size,
2743 empty, left, free_space, right_nritems);
2745 btrfs_tree_unlock(left);
2746 free_extent_buffer(left);
2751 * split the path's leaf in two, making sure there is at least data_size
2752 * available for the resulting leaf level of the path.
2754 * returns 0 if all went well and < 0 on failure.
2756 static noinline int copy_for_split(struct btrfs_trans_handle *trans,
2757 struct btrfs_root *root,
2758 struct btrfs_path *path,
2759 struct extent_buffer *l,
2760 struct extent_buffer *right,
2761 int slot, int mid, int nritems)
2768 struct btrfs_disk_key disk_key;
2770 nritems = nritems - mid;
2771 btrfs_set_header_nritems(right, nritems);
2772 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2774 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2775 btrfs_item_nr_offset(mid),
2776 nritems * sizeof(struct btrfs_item));
2778 copy_extent_buffer(right, l,
2779 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2780 data_copy_size, btrfs_leaf_data(l) +
2781 leaf_data_end(root, l), data_copy_size);
2783 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2784 btrfs_item_end_nr(l, mid);
2786 for (i = 0; i < nritems; i++) {
2787 struct btrfs_item *item = btrfs_item_nr(right, i);
2790 if (!right->map_token) {
2791 map_extent_buffer(right, (unsigned long)item,
2792 sizeof(struct btrfs_item),
2793 &right->map_token, &right->kaddr,
2794 &right->map_start, &right->map_len,
2798 ioff = btrfs_item_offset(right, item);
2799 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2802 if (right->map_token) {
2803 unmap_extent_buffer(right, right->map_token, KM_USER1);
2804 right->map_token = NULL;
2807 btrfs_set_header_nritems(l, mid);
2809 btrfs_item_key(right, &disk_key, 0);
2810 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2811 path->slots[1] + 1, 1);
2815 btrfs_mark_buffer_dirty(right);
2816 btrfs_mark_buffer_dirty(l);
2817 BUG_ON(path->slots[0] != slot);
2820 btrfs_tree_unlock(path->nodes[0]);
2821 free_extent_buffer(path->nodes[0]);
2822 path->nodes[0] = right;
2823 path->slots[0] -= mid;
2824 path->slots[1] += 1;
2826 btrfs_tree_unlock(right);
2827 free_extent_buffer(right);
2830 BUG_ON(path->slots[0] < 0);
2836 * split the path's leaf in two, making sure there is at least data_size
2837 * available for the resulting leaf level of the path.
2839 * returns 0 if all went well and < 0 on failure.
2841 static noinline int split_leaf(struct btrfs_trans_handle *trans,
2842 struct btrfs_root *root,
2843 struct btrfs_key *ins_key,
2844 struct btrfs_path *path, int data_size,
2847 struct btrfs_disk_key disk_key;
2848 struct extent_buffer *l;
2852 struct extent_buffer *right;
2856 int num_doubles = 0;
2859 slot = path->slots[0];
2860 if (extend && data_size + btrfs_item_size_nr(l, slot) +
2861 sizeof(struct btrfs_item) > BTRFS_LEAF_DATA_SIZE(root))
2864 /* first try to make some room by pushing left and right */
2865 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
2866 wret = push_leaf_right(trans, root, path, data_size, 0);
2870 wret = push_leaf_left(trans, root, path, data_size, 0);
2876 /* did the pushes work? */
2877 if (btrfs_leaf_free_space(root, l) >= data_size)
2881 if (!path->nodes[1]) {
2882 ret = insert_new_root(trans, root, path, 1);
2889 slot = path->slots[0];
2890 nritems = btrfs_header_nritems(l);
2891 mid = (nritems + 1) / 2;
2895 leaf_space_used(l, mid, nritems - mid) + data_size >
2896 BTRFS_LEAF_DATA_SIZE(root)) {
2897 if (slot >= nritems) {
2901 if (mid != nritems &&
2902 leaf_space_used(l, mid, nritems - mid) +
2903 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2909 if (leaf_space_used(l, 0, mid) + data_size >
2910 BTRFS_LEAF_DATA_SIZE(root)) {
2911 if (!extend && data_size && slot == 0) {
2913 } else if ((extend || !data_size) && slot == 0) {
2917 if (mid != nritems &&
2918 leaf_space_used(l, mid, nritems - mid) +
2919 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2927 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2929 btrfs_item_key(l, &disk_key, mid);
2931 right = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
2932 root->root_key.objectid,
2933 &disk_key, 0, l->start, 0);
2934 if (IS_ERR(right)) {
2936 return PTR_ERR(right);
2939 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2940 btrfs_set_header_bytenr(right, right->start);
2941 btrfs_set_header_generation(right, trans->transid);
2942 btrfs_set_header_backref_rev(right, BTRFS_MIXED_BACKREF_REV);
2943 btrfs_set_header_owner(right, root->root_key.objectid);
2944 btrfs_set_header_level(right, 0);
2945 write_extent_buffer(right, root->fs_info->fsid,
2946 (unsigned long)btrfs_header_fsid(right),
2949 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2950 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2955 btrfs_set_header_nritems(right, 0);
2956 wret = insert_ptr(trans, root, path,
2957 &disk_key, right->start,
2958 path->slots[1] + 1, 1);
2962 btrfs_tree_unlock(path->nodes[0]);
2963 free_extent_buffer(path->nodes[0]);
2964 path->nodes[0] = right;
2966 path->slots[1] += 1;
2968 btrfs_set_header_nritems(right, 0);
2969 wret = insert_ptr(trans, root, path,
2975 btrfs_tree_unlock(path->nodes[0]);
2976 free_extent_buffer(path->nodes[0]);
2977 path->nodes[0] = right;
2979 if (path->slots[1] == 0) {
2980 wret = fixup_low_keys(trans, root,
2981 path, &disk_key, 1);
2986 btrfs_mark_buffer_dirty(right);
2990 ret = copy_for_split(trans, root, path, l, right, slot, mid, nritems);
2994 BUG_ON(num_doubles != 0);
3002 static noinline int setup_leaf_for_split(struct btrfs_trans_handle *trans,
3003 struct btrfs_root *root,
3004 struct btrfs_path *path, int ins_len)
3006 struct btrfs_key key;
3007 struct extent_buffer *leaf;
3008 struct btrfs_file_extent_item *fi;
3013 leaf = path->nodes[0];
3014 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3016 BUG_ON(key.type != BTRFS_EXTENT_DATA_KEY &&
3017 key.type != BTRFS_EXTENT_CSUM_KEY);
3019 if (btrfs_leaf_free_space(root, leaf) >= ins_len)
3022 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3023 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3024 fi = btrfs_item_ptr(leaf, path->slots[0],
3025 struct btrfs_file_extent_item);
3026 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
3028 btrfs_release_path(root, path);
3030 path->keep_locks = 1;
3031 path->search_for_split = 1;
3032 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
3033 path->search_for_split = 0;
3038 leaf = path->nodes[0];
3039 /* if our item isn't there or got smaller, return now */
3040 if (ret > 0 || item_size != btrfs_item_size_nr(leaf, path->slots[0]))
3043 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3044 fi = btrfs_item_ptr(leaf, path->slots[0],
3045 struct btrfs_file_extent_item);
3046 if (extent_len != btrfs_file_extent_num_bytes(leaf, fi))
3050 btrfs_set_path_blocking(path);
3051 ret = split_leaf(trans, root, &key, path, ins_len, 1);
3054 path->keep_locks = 0;
3055 btrfs_unlock_up_safe(path, 1);
3058 path->keep_locks = 0;
3062 static noinline int split_item(struct btrfs_trans_handle *trans,
3063 struct btrfs_root *root,
3064 struct btrfs_path *path,
3065 struct btrfs_key *new_key,
3066 unsigned long split_offset)
3068 struct extent_buffer *leaf;
3069 struct btrfs_item *item;
3070 struct btrfs_item *new_item;
3076 struct btrfs_disk_key disk_key;
3078 leaf = path->nodes[0];
3079 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
3081 btrfs_set_path_blocking(path);
3083 item = btrfs_item_nr(leaf, path->slots[0]);
3084 orig_offset = btrfs_item_offset(leaf, item);
3085 item_size = btrfs_item_size(leaf, item);
3087 buf = kmalloc(item_size, GFP_NOFS);
3091 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
3092 path->slots[0]), item_size);
3094 slot = path->slots[0] + 1;
3095 nritems = btrfs_header_nritems(leaf);
3096 if (slot != nritems) {
3097 /* shift the items */
3098 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
3099 btrfs_item_nr_offset(slot),
3100 (nritems - slot) * sizeof(struct btrfs_item));
3103 btrfs_cpu_key_to_disk(&disk_key, new_key);
3104 btrfs_set_item_key(leaf, &disk_key, slot);
3106 new_item = btrfs_item_nr(leaf, slot);
3108 btrfs_set_item_offset(leaf, new_item, orig_offset);
3109 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
3111 btrfs_set_item_offset(leaf, item,
3112 orig_offset + item_size - split_offset);
3113 btrfs_set_item_size(leaf, item, split_offset);
3115 btrfs_set_header_nritems(leaf, nritems + 1);
3117 /* write the data for the start of the original item */
3118 write_extent_buffer(leaf, buf,
3119 btrfs_item_ptr_offset(leaf, path->slots[0]),
3122 /* write the data for the new item */
3123 write_extent_buffer(leaf, buf + split_offset,
3124 btrfs_item_ptr_offset(leaf, slot),
3125 item_size - split_offset);
3126 btrfs_mark_buffer_dirty(leaf);
3128 BUG_ON(btrfs_leaf_free_space(root, leaf) < 0);
3134 * This function splits a single item into two items,
3135 * giving 'new_key' to the new item and splitting the
3136 * old one at split_offset (from the start of the item).
3138 * The path may be released by this operation. After
3139 * the split, the path is pointing to the old item. The
3140 * new item is going to be in the same node as the old one.
3142 * Note, the item being split must be smaller enough to live alone on
3143 * a tree block with room for one extra struct btrfs_item
3145 * This allows us to split the item in place, keeping a lock on the
3146 * leaf the entire time.
3148 int btrfs_split_item(struct btrfs_trans_handle *trans,
3149 struct btrfs_root *root,
3150 struct btrfs_path *path,
3151 struct btrfs_key *new_key,
3152 unsigned long split_offset)
3155 ret = setup_leaf_for_split(trans, root, path,
3156 sizeof(struct btrfs_item));
3160 ret = split_item(trans, root, path, new_key, split_offset);
3165 * This function duplicate a item, giving 'new_key' to the new item.
3166 * It guarantees both items live in the same tree leaf and the new item
3167 * is contiguous with the original item.
3169 * This allows us to split file extent in place, keeping a lock on the
3170 * leaf the entire time.
3172 int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
3173 struct btrfs_root *root,
3174 struct btrfs_path *path,
3175 struct btrfs_key *new_key)
3177 struct extent_buffer *leaf;
3181 leaf = path->nodes[0];
3182 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
3183 ret = setup_leaf_for_split(trans, root, path,
3184 item_size + sizeof(struct btrfs_item));
3189 ret = setup_items_for_insert(trans, root, path, new_key, &item_size,
3190 item_size, item_size +
3191 sizeof(struct btrfs_item), 1);
3194 leaf = path->nodes[0];
3195 memcpy_extent_buffer(leaf,
3196 btrfs_item_ptr_offset(leaf, path->slots[0]),
3197 btrfs_item_ptr_offset(leaf, path->slots[0] - 1),
3203 * make the item pointed to by the path smaller. new_size indicates
3204 * how small to make it, and from_end tells us if we just chop bytes
3205 * off the end of the item or if we shift the item to chop bytes off
3208 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
3209 struct btrfs_root *root,
3210 struct btrfs_path *path,
3211 u32 new_size, int from_end)
3216 struct extent_buffer *leaf;
3217 struct btrfs_item *item;
3219 unsigned int data_end;
3220 unsigned int old_data_start;
3221 unsigned int old_size;
3222 unsigned int size_diff;
3225 slot_orig = path->slots[0];
3226 leaf = path->nodes[0];
3227 slot = path->slots[0];
3229 old_size = btrfs_item_size_nr(leaf, slot);
3230 if (old_size == new_size)
3233 nritems = btrfs_header_nritems(leaf);
3234 data_end = leaf_data_end(root, leaf);
3236 old_data_start = btrfs_item_offset_nr(leaf, slot);
3238 size_diff = old_size - new_size;
3241 BUG_ON(slot >= nritems);
3244 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3246 /* first correct the data pointers */
3247 for (i = slot; i < nritems; i++) {
3249 item = btrfs_item_nr(leaf, i);
3251 if (!leaf->map_token) {
3252 map_extent_buffer(leaf, (unsigned long)item,
3253 sizeof(struct btrfs_item),
3254 &leaf->map_token, &leaf->kaddr,
3255 &leaf->map_start, &leaf->map_len,
3259 ioff = btrfs_item_offset(leaf, item);
3260 btrfs_set_item_offset(leaf, item, ioff + size_diff);
3263 if (leaf->map_token) {
3264 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3265 leaf->map_token = NULL;
3268 /* shift the data */
3270 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3271 data_end + size_diff, btrfs_leaf_data(leaf) +
3272 data_end, old_data_start + new_size - data_end);
3274 struct btrfs_disk_key disk_key;
3277 btrfs_item_key(leaf, &disk_key, slot);
3279 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
3281 struct btrfs_file_extent_item *fi;
3283 fi = btrfs_item_ptr(leaf, slot,
3284 struct btrfs_file_extent_item);
3285 fi = (struct btrfs_file_extent_item *)(
3286 (unsigned long)fi - size_diff);
3288 if (btrfs_file_extent_type(leaf, fi) ==
3289 BTRFS_FILE_EXTENT_INLINE) {
3290 ptr = btrfs_item_ptr_offset(leaf, slot);
3291 memmove_extent_buffer(leaf, ptr,
3293 offsetof(struct btrfs_file_extent_item,
3298 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3299 data_end + size_diff, btrfs_leaf_data(leaf) +
3300 data_end, old_data_start - data_end);
3302 offset = btrfs_disk_key_offset(&disk_key);
3303 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
3304 btrfs_set_item_key(leaf, &disk_key, slot);
3306 fixup_low_keys(trans, root, path, &disk_key, 1);
3309 item = btrfs_item_nr(leaf, slot);
3310 btrfs_set_item_size(leaf, item, new_size);
3311 btrfs_mark_buffer_dirty(leaf);
3314 if (btrfs_leaf_free_space(root, leaf) < 0) {
3315 btrfs_print_leaf(root, leaf);
3322 * make the item pointed to by the path bigger, data_size is the new size.
3324 int btrfs_extend_item(struct btrfs_trans_handle *trans,
3325 struct btrfs_root *root, struct btrfs_path *path,
3331 struct extent_buffer *leaf;
3332 struct btrfs_item *item;
3334 unsigned int data_end;
3335 unsigned int old_data;
3336 unsigned int old_size;
3339 slot_orig = path->slots[0];
3340 leaf = path->nodes[0];
3342 nritems = btrfs_header_nritems(leaf);
3343 data_end = leaf_data_end(root, leaf);
3345 if (btrfs_leaf_free_space(root, leaf) < data_size) {
3346 btrfs_print_leaf(root, leaf);
3349 slot = path->slots[0];
3350 old_data = btrfs_item_end_nr(leaf, slot);
3353 if (slot >= nritems) {
3354 btrfs_print_leaf(root, leaf);
3355 printk(KERN_CRIT "slot %d too large, nritems %d\n",
3361 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3363 /* first correct the data pointers */
3364 for (i = slot; i < nritems; i++) {
3366 item = btrfs_item_nr(leaf, i);
3368 if (!leaf->map_token) {
3369 map_extent_buffer(leaf, (unsigned long)item,
3370 sizeof(struct btrfs_item),
3371 &leaf->map_token, &leaf->kaddr,
3372 &leaf->map_start, &leaf->map_len,
3375 ioff = btrfs_item_offset(leaf, item);
3376 btrfs_set_item_offset(leaf, item, ioff - data_size);
3379 if (leaf->map_token) {
3380 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3381 leaf->map_token = NULL;
3384 /* shift the data */
3385 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3386 data_end - data_size, btrfs_leaf_data(leaf) +
3387 data_end, old_data - data_end);
3389 data_end = old_data;
3390 old_size = btrfs_item_size_nr(leaf, slot);
3391 item = btrfs_item_nr(leaf, slot);
3392 btrfs_set_item_size(leaf, item, old_size + data_size);
3393 btrfs_mark_buffer_dirty(leaf);
3396 if (btrfs_leaf_free_space(root, leaf) < 0) {
3397 btrfs_print_leaf(root, leaf);
3404 * Given a key and some data, insert items into the tree.
3405 * This does all the path init required, making room in the tree if needed.
3406 * Returns the number of keys that were inserted.
3408 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
3409 struct btrfs_root *root,
3410 struct btrfs_path *path,
3411 struct btrfs_key *cpu_key, u32 *data_size,
3414 struct extent_buffer *leaf;
3415 struct btrfs_item *item;
3422 unsigned int data_end;
3423 struct btrfs_disk_key disk_key;
3424 struct btrfs_key found_key;
3426 for (i = 0; i < nr; i++) {
3427 if (total_size + data_size[i] + sizeof(struct btrfs_item) >
3428 BTRFS_LEAF_DATA_SIZE(root)) {
3432 total_data += data_size[i];
3433 total_size += data_size[i] + sizeof(struct btrfs_item);
3437 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3443 leaf = path->nodes[0];
3445 nritems = btrfs_header_nritems(leaf);
3446 data_end = leaf_data_end(root, leaf);
3448 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3449 for (i = nr; i >= 0; i--) {
3450 total_data -= data_size[i];
3451 total_size -= data_size[i] + sizeof(struct btrfs_item);
3452 if (total_size < btrfs_leaf_free_space(root, leaf))
3458 slot = path->slots[0];
3461 if (slot != nritems) {
3462 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3464 item = btrfs_item_nr(leaf, slot);
3465 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3467 /* figure out how many keys we can insert in here */
3468 total_data = data_size[0];
3469 for (i = 1; i < nr; i++) {
3470 if (btrfs_comp_cpu_keys(&found_key, cpu_key + i) <= 0)
3472 total_data += data_size[i];
3476 if (old_data < data_end) {
3477 btrfs_print_leaf(root, leaf);
3478 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
3479 slot, old_data, data_end);
3483 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3485 /* first correct the data pointers */
3486 WARN_ON(leaf->map_token);
3487 for (i = slot; i < nritems; i++) {
3490 item = btrfs_item_nr(leaf, i);
3491 if (!leaf->map_token) {
3492 map_extent_buffer(leaf, (unsigned long)item,
3493 sizeof(struct btrfs_item),
3494 &leaf->map_token, &leaf->kaddr,
3495 &leaf->map_start, &leaf->map_len,
3499 ioff = btrfs_item_offset(leaf, item);
3500 btrfs_set_item_offset(leaf, item, ioff - total_data);
3502 if (leaf->map_token) {
3503 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3504 leaf->map_token = NULL;
3507 /* shift the items */
3508 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3509 btrfs_item_nr_offset(slot),
3510 (nritems - slot) * sizeof(struct btrfs_item));
3512 /* shift the data */
3513 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3514 data_end - total_data, btrfs_leaf_data(leaf) +
3515 data_end, old_data - data_end);
3516 data_end = old_data;
3519 * this sucks but it has to be done, if we are inserting at
3520 * the end of the leaf only insert 1 of the items, since we
3521 * have no way of knowing whats on the next leaf and we'd have
3522 * to drop our current locks to figure it out
3527 /* setup the item for the new data */
3528 for (i = 0; i < nr; i++) {
3529 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3530 btrfs_set_item_key(leaf, &disk_key, slot + i);
3531 item = btrfs_item_nr(leaf, slot + i);
3532 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3533 data_end -= data_size[i];
3534 btrfs_set_item_size(leaf, item, data_size[i]);
3536 btrfs_set_header_nritems(leaf, nritems + nr);
3537 btrfs_mark_buffer_dirty(leaf);
3541 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3542 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3545 if (btrfs_leaf_free_space(root, leaf) < 0) {
3546 btrfs_print_leaf(root, leaf);
3556 * this is a helper for btrfs_insert_empty_items, the main goal here is
3557 * to save stack depth by doing the bulk of the work in a function
3558 * that doesn't call btrfs_search_slot
3560 static noinline_for_stack int
3561 setup_items_for_insert(struct btrfs_trans_handle *trans,
3562 struct btrfs_root *root, struct btrfs_path *path,
3563 struct btrfs_key *cpu_key, u32 *data_size,
3564 u32 total_data, u32 total_size, int nr)
3566 struct btrfs_item *item;
3569 unsigned int data_end;
3570 struct btrfs_disk_key disk_key;
3572 struct extent_buffer *leaf;
3575 leaf = path->nodes[0];
3576 slot = path->slots[0];
3578 nritems = btrfs_header_nritems(leaf);
3579 data_end = leaf_data_end(root, leaf);
3581 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3582 btrfs_print_leaf(root, leaf);
3583 printk(KERN_CRIT "not enough freespace need %u have %d\n",
3584 total_size, btrfs_leaf_free_space(root, leaf));
3588 if (slot != nritems) {
3589 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3591 if (old_data < data_end) {
3592 btrfs_print_leaf(root, leaf);
3593 printk(KERN_CRIT "slot %d old_data %d data_end %d\n",
3594 slot, old_data, data_end);
3598 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3600 /* first correct the data pointers */
3601 WARN_ON(leaf->map_token);
3602 for (i = slot; i < nritems; i++) {
3605 item = btrfs_item_nr(leaf, i);
3606 if (!leaf->map_token) {
3607 map_extent_buffer(leaf, (unsigned long)item,
3608 sizeof(struct btrfs_item),
3609 &leaf->map_token, &leaf->kaddr,
3610 &leaf->map_start, &leaf->map_len,
3614 ioff = btrfs_item_offset(leaf, item);
3615 btrfs_set_item_offset(leaf, item, ioff - total_data);
3617 if (leaf->map_token) {
3618 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3619 leaf->map_token = NULL;
3622 /* shift the items */
3623 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3624 btrfs_item_nr_offset(slot),
3625 (nritems - slot) * sizeof(struct btrfs_item));
3627 /* shift the data */
3628 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3629 data_end - total_data, btrfs_leaf_data(leaf) +
3630 data_end, old_data - data_end);
3631 data_end = old_data;
3634 /* setup the item for the new data */
3635 for (i = 0; i < nr; i++) {
3636 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3637 btrfs_set_item_key(leaf, &disk_key, slot + i);
3638 item = btrfs_item_nr(leaf, slot + i);
3639 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3640 data_end -= data_size[i];
3641 btrfs_set_item_size(leaf, item, data_size[i]);
3644 btrfs_set_header_nritems(leaf, nritems + nr);
3648 struct btrfs_disk_key disk_key;
3649 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3650 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3652 btrfs_unlock_up_safe(path, 1);
3653 btrfs_mark_buffer_dirty(leaf);
3655 if (btrfs_leaf_free_space(root, leaf) < 0) {
3656 btrfs_print_leaf(root, leaf);
3663 * Given a key and some data, insert items into the tree.
3664 * This does all the path init required, making room in the tree if needed.
3666 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
3667 struct btrfs_root *root,
3668 struct btrfs_path *path,
3669 struct btrfs_key *cpu_key, u32 *data_size,
3672 struct extent_buffer *leaf;
3679 for (i = 0; i < nr; i++)
3680 total_data += data_size[i];
3682 total_size = total_data + (nr * sizeof(struct btrfs_item));
3683 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3689 leaf = path->nodes[0];
3690 slot = path->slots[0];
3693 ret = setup_items_for_insert(trans, root, path, cpu_key, data_size,
3694 total_data, total_size, nr);
3701 * Given a key and some data, insert an item into the tree.
3702 * This does all the path init required, making room in the tree if needed.
3704 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
3705 *root, struct btrfs_key *cpu_key, void *data, u32
3709 struct btrfs_path *path;
3710 struct extent_buffer *leaf;
3713 path = btrfs_alloc_path();
3715 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
3717 leaf = path->nodes[0];
3718 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3719 write_extent_buffer(leaf, data, ptr, data_size);
3720 btrfs_mark_buffer_dirty(leaf);
3722 btrfs_free_path(path);
3727 * delete the pointer from a given node.
3729 * the tree should have been previously balanced so the deletion does not
3732 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3733 struct btrfs_path *path, int level, int slot)
3735 struct extent_buffer *parent = path->nodes[level];
3740 nritems = btrfs_header_nritems(parent);
3741 if (slot != nritems - 1) {
3742 memmove_extent_buffer(parent,
3743 btrfs_node_key_ptr_offset(slot),
3744 btrfs_node_key_ptr_offset(slot + 1),
3745 sizeof(struct btrfs_key_ptr) *
3746 (nritems - slot - 1));
3749 btrfs_set_header_nritems(parent, nritems);
3750 if (nritems == 0 && parent == root->node) {
3751 BUG_ON(btrfs_header_level(root->node) != 1);
3752 /* just turn the root into a leaf and break */
3753 btrfs_set_header_level(root->node, 0);
3754 } else if (slot == 0) {
3755 struct btrfs_disk_key disk_key;
3757 btrfs_node_key(parent, &disk_key, 0);
3758 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
3762 btrfs_mark_buffer_dirty(parent);
3767 * a helper function to delete the leaf pointed to by path->slots[1] and
3770 * This deletes the pointer in path->nodes[1] and frees the leaf
3771 * block extent. zero is returned if it all worked out, < 0 otherwise.
3773 * The path must have already been setup for deleting the leaf, including
3774 * all the proper balancing. path->nodes[1] must be locked.
3776 static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
3777 struct btrfs_root *root,
3778 struct btrfs_path *path,
3779 struct extent_buffer *leaf)
3783 WARN_ON(btrfs_header_generation(leaf) != trans->transid);
3784 ret = del_ptr(trans, root, path, 1, path->slots[1]);
3789 * btrfs_free_extent is expensive, we want to make sure we
3790 * aren't holding any locks when we call it
3792 btrfs_unlock_up_safe(path, 0);
3794 ret = btrfs_free_tree_block(trans, root, leaf->start, leaf->len,
3795 0, root->root_key.objectid, 0);
3799 * delete the item at the leaf level in path. If that empties
3800 * the leaf, remove it from the tree
3802 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3803 struct btrfs_path *path, int slot, int nr)
3805 struct extent_buffer *leaf;
3806 struct btrfs_item *item;
3814 leaf = path->nodes[0];
3815 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
3817 for (i = 0; i < nr; i++)
3818 dsize += btrfs_item_size_nr(leaf, slot + i);
3820 nritems = btrfs_header_nritems(leaf);
3822 if (slot + nr != nritems) {
3823 int data_end = leaf_data_end(root, leaf);
3825 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3827 btrfs_leaf_data(leaf) + data_end,
3828 last_off - data_end);
3830 for (i = slot + nr; i < nritems; i++) {
3833 item = btrfs_item_nr(leaf, i);
3834 if (!leaf->map_token) {
3835 map_extent_buffer(leaf, (unsigned long)item,
3836 sizeof(struct btrfs_item),
3837 &leaf->map_token, &leaf->kaddr,
3838 &leaf->map_start, &leaf->map_len,
3841 ioff = btrfs_item_offset(leaf, item);
3842 btrfs_set_item_offset(leaf, item, ioff + dsize);
3845 if (leaf->map_token) {
3846 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3847 leaf->map_token = NULL;
3850 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
3851 btrfs_item_nr_offset(slot + nr),
3852 sizeof(struct btrfs_item) *
3853 (nritems - slot - nr));
3855 btrfs_set_header_nritems(leaf, nritems - nr);
3858 /* delete the leaf if we've emptied it */
3860 if (leaf == root->node) {
3861 btrfs_set_header_level(leaf, 0);
3863 ret = btrfs_del_leaf(trans, root, path, leaf);
3867 int used = leaf_space_used(leaf, 0, nritems);
3869 struct btrfs_disk_key disk_key;
3871 btrfs_item_key(leaf, &disk_key, 0);
3872 wret = fixup_low_keys(trans, root, path,
3878 /* delete the leaf if it is mostly empty */
3879 if (used < BTRFS_LEAF_DATA_SIZE(root) / 3) {
3880 /* push_leaf_left fixes the path.
3881 * make sure the path still points to our leaf
3882 * for possible call to del_ptr below
3884 slot = path->slots[1];
3885 extent_buffer_get(leaf);
3887 btrfs_set_path_blocking(path);
3888 wret = push_leaf_left(trans, root, path, 1, 1);
3889 if (wret < 0 && wret != -ENOSPC)
3892 if (path->nodes[0] == leaf &&
3893 btrfs_header_nritems(leaf)) {
3894 wret = push_leaf_right(trans, root, path, 1, 1);
3895 if (wret < 0 && wret != -ENOSPC)
3899 if (btrfs_header_nritems(leaf) == 0) {
3900 path->slots[1] = slot;
3901 ret = btrfs_del_leaf(trans, root, path, leaf);
3903 free_extent_buffer(leaf);
3905 /* if we're still in the path, make sure
3906 * we're dirty. Otherwise, one of the
3907 * push_leaf functions must have already
3908 * dirtied this buffer
3910 if (path->nodes[0] == leaf)
3911 btrfs_mark_buffer_dirty(leaf);
3912 free_extent_buffer(leaf);
3915 btrfs_mark_buffer_dirty(leaf);
3922 * search the tree again to find a leaf with lesser keys
3923 * returns 0 if it found something or 1 if there are no lesser leaves.
3924 * returns < 0 on io errors.
3926 * This may release the path, and so you may lose any locks held at the
3929 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
3931 struct btrfs_key key;
3932 struct btrfs_disk_key found_key;
3935 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
3939 else if (key.type > 0)
3941 else if (key.objectid > 0)
3946 btrfs_release_path(root, path);
3947 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3950 btrfs_item_key(path->nodes[0], &found_key, 0);
3951 ret = comp_keys(&found_key, &key);
3958 * A helper function to walk down the tree starting at min_key, and looking
3959 * for nodes or leaves that are either in cache or have a minimum
3960 * transaction id. This is used by the btree defrag code, and tree logging
3962 * This does not cow, but it does stuff the starting key it finds back
3963 * into min_key, so you can call btrfs_search_slot with cow=1 on the
3964 * key and get a writable path.
3966 * This does lock as it descends, and path->keep_locks should be set
3967 * to 1 by the caller.
3969 * This honors path->lowest_level to prevent descent past a given level
3972 * min_trans indicates the oldest transaction that you are interested
3973 * in walking through. Any nodes or leaves older than min_trans are
3974 * skipped over (without reading them).
3976 * returns zero if something useful was found, < 0 on error and 1 if there
3977 * was nothing in the tree that matched the search criteria.
3979 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
3980 struct btrfs_key *max_key,
3981 struct btrfs_path *path, int cache_only,
3984 struct extent_buffer *cur;
3985 struct btrfs_key found_key;
3992 WARN_ON(!path->keep_locks);
3994 cur = btrfs_lock_root_node(root);
3995 level = btrfs_header_level(cur);
3996 WARN_ON(path->nodes[level]);
3997 path->nodes[level] = cur;
3998 path->locks[level] = 1;
4000 if (btrfs_header_generation(cur) < min_trans) {
4005 nritems = btrfs_header_nritems(cur);
4006 level = btrfs_header_level(cur);
4007 sret = bin_search(cur, min_key, level, &slot);
4009 /* at the lowest level, we're done, setup the path and exit */
4010 if (level == path->lowest_level) {
4011 if (slot >= nritems)
4014 path->slots[level] = slot;
4015 btrfs_item_key_to_cpu(cur, &found_key, slot);
4018 if (sret && slot > 0)
4021 * check this node pointer against the cache_only and
4022 * min_trans parameters. If it isn't in cache or is too
4023 * old, skip to the next one.
4025 while (slot < nritems) {
4028 struct extent_buffer *tmp;
4029 struct btrfs_disk_key disk_key;
4031 blockptr = btrfs_node_blockptr(cur, slot);
4032 gen = btrfs_node_ptr_generation(cur, slot);
4033 if (gen < min_trans) {
4041 btrfs_node_key(cur, &disk_key, slot);
4042 if (comp_keys(&disk_key, max_key) >= 0) {
4048 tmp = btrfs_find_tree_block(root, blockptr,
4049 btrfs_level_size(root, level - 1));
4051 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
4052 free_extent_buffer(tmp);
4056 free_extent_buffer(tmp);
4061 * we didn't find a candidate key in this node, walk forward
4062 * and find another one
4064 if (slot >= nritems) {
4065 path->slots[level] = slot;
4066 btrfs_set_path_blocking(path);
4067 sret = btrfs_find_next_key(root, path, min_key, level,
4068 cache_only, min_trans);
4070 btrfs_release_path(root, path);
4076 /* save our key for returning back */
4077 btrfs_node_key_to_cpu(cur, &found_key, slot);
4078 path->slots[level] = slot;
4079 if (level == path->lowest_level) {
4081 unlock_up(path, level, 1);
4084 btrfs_set_path_blocking(path);
4085 cur = read_node_slot(root, cur, slot);
4087 btrfs_tree_lock(cur);
4089 path->locks[level - 1] = 1;
4090 path->nodes[level - 1] = cur;
4091 unlock_up(path, level, 1);
4092 btrfs_clear_path_blocking(path, NULL);
4096 memcpy(min_key, &found_key, sizeof(found_key));
4097 btrfs_set_path_blocking(path);
4102 * this is similar to btrfs_next_leaf, but does not try to preserve
4103 * and fixup the path. It looks for and returns the next key in the
4104 * tree based on the current path and the cache_only and min_trans
4107 * 0 is returned if another key is found, < 0 if there are any errors
4108 * and 1 is returned if there are no higher keys in the tree
4110 * path->keep_locks should be set to 1 on the search made before
4111 * calling this function.
4113 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
4114 struct btrfs_key *key, int level,
4115 int cache_only, u64 min_trans)
4118 struct extent_buffer *c;
4120 WARN_ON(!path->keep_locks);
4121 while (level < BTRFS_MAX_LEVEL) {
4122 if (!path->nodes[level])
4125 slot = path->slots[level] + 1;
4126 c = path->nodes[level];
4128 if (slot >= btrfs_header_nritems(c)) {
4131 struct btrfs_key cur_key;
4132 if (level + 1 >= BTRFS_MAX_LEVEL ||
4133 !path->nodes[level + 1])
4136 if (path->locks[level + 1]) {
4141 slot = btrfs_header_nritems(c) - 1;
4143 btrfs_item_key_to_cpu(c, &cur_key, slot);
4145 btrfs_node_key_to_cpu(c, &cur_key, slot);
4147 orig_lowest = path->lowest_level;
4148 btrfs_release_path(root, path);
4149 path->lowest_level = level;
4150 ret = btrfs_search_slot(NULL, root, &cur_key, path,
4152 path->lowest_level = orig_lowest;
4156 c = path->nodes[level];
4157 slot = path->slots[level];
4164 btrfs_item_key_to_cpu(c, key, slot);
4166 u64 blockptr = btrfs_node_blockptr(c, slot);
4167 u64 gen = btrfs_node_ptr_generation(c, slot);
4170 struct extent_buffer *cur;
4171 cur = btrfs_find_tree_block(root, blockptr,
4172 btrfs_level_size(root, level - 1));
4173 if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
4176 free_extent_buffer(cur);
4179 free_extent_buffer(cur);
4181 if (gen < min_trans) {
4185 btrfs_node_key_to_cpu(c, key, slot);
4193 * search the tree again to find a leaf with greater keys
4194 * returns 0 if it found something or 1 if there are no greater leaves.
4195 * returns < 0 on io errors.
4197 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
4201 struct extent_buffer *c;
4202 struct extent_buffer *next;
4203 struct btrfs_key key;
4206 int old_spinning = path->leave_spinning;
4207 int force_blocking = 0;
4209 nritems = btrfs_header_nritems(path->nodes[0]);
4214 * we take the blocks in an order that upsets lockdep. Using
4215 * blocking mode is the only way around it.
4217 #ifdef CONFIG_DEBUG_LOCK_ALLOC
4221 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
4225 btrfs_release_path(root, path);
4227 path->keep_locks = 1;
4229 if (!force_blocking)
4230 path->leave_spinning = 1;
4232 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4233 path->keep_locks = 0;
4238 nritems = btrfs_header_nritems(path->nodes[0]);
4240 * by releasing the path above we dropped all our locks. A balance
4241 * could have added more items next to the key that used to be
4242 * at the very end of the block. So, check again here and
4243 * advance the path if there are now more items available.
4245 if (nritems > 0 && path->slots[0] < nritems - 1) {
4252 while (level < BTRFS_MAX_LEVEL) {
4253 if (!path->nodes[level]) {
4258 slot = path->slots[level] + 1;
4259 c = path->nodes[level];
4260 if (slot >= btrfs_header_nritems(c)) {
4262 if (level == BTRFS_MAX_LEVEL) {
4270 btrfs_tree_unlock(next);
4271 free_extent_buffer(next);
4275 ret = read_block_for_search(NULL, root, path, &next, level,
4281 btrfs_release_path(root, path);
4285 if (!path->skip_locking) {
4286 ret = btrfs_try_spin_lock(next);
4288 btrfs_set_path_blocking(path);
4289 btrfs_tree_lock(next);
4290 if (!force_blocking)
4291 btrfs_clear_path_blocking(path, next);
4294 btrfs_set_lock_blocking(next);
4298 path->slots[level] = slot;
4301 c = path->nodes[level];
4302 if (path->locks[level])
4303 btrfs_tree_unlock(c);
4305 free_extent_buffer(c);
4306 path->nodes[level] = next;
4307 path->slots[level] = 0;
4308 if (!path->skip_locking)
4309 path->locks[level] = 1;
4314 ret = read_block_for_search(NULL, root, path, &next, level,
4320 btrfs_release_path(root, path);
4324 if (!path->skip_locking) {
4325 btrfs_assert_tree_locked(path->nodes[level]);
4326 ret = btrfs_try_spin_lock(next);
4328 btrfs_set_path_blocking(path);
4329 btrfs_tree_lock(next);
4330 if (!force_blocking)
4331 btrfs_clear_path_blocking(path, next);
4334 btrfs_set_lock_blocking(next);
4339 unlock_up(path, 0, 1);
4340 path->leave_spinning = old_spinning;
4342 btrfs_set_path_blocking(path);
4348 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
4349 * searching until it gets past min_objectid or finds an item of 'type'
4351 * returns 0 if something is found, 1 if nothing was found and < 0 on error
4353 int btrfs_previous_item(struct btrfs_root *root,
4354 struct btrfs_path *path, u64 min_objectid,
4357 struct btrfs_key found_key;
4358 struct extent_buffer *leaf;
4363 if (path->slots[0] == 0) {
4364 btrfs_set_path_blocking(path);
4365 ret = btrfs_prev_leaf(root, path);
4371 leaf = path->nodes[0];
4372 nritems = btrfs_header_nritems(leaf);
4375 if (path->slots[0] == nritems)
4378 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4379 if (found_key.objectid < min_objectid)
4381 if (found_key.type == type)
4383 if (found_key.objectid == min_objectid &&
4384 found_key.type < type)