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);
41 inline void btrfs_init_path(struct btrfs_path *p)
43 memset(p, 0, sizeof(*p));
46 struct btrfs_path *btrfs_alloc_path(void)
48 struct btrfs_path *path;
49 path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
51 btrfs_init_path(path);
57 /* this also releases the path */
58 void btrfs_free_path(struct btrfs_path *p)
60 btrfs_release_path(NULL, p);
61 kmem_cache_free(btrfs_path_cachep, p);
65 * path release drops references on the extent buffers in the path
66 * and it drops any locks held by this path
68 * It is safe to call this on paths that no locks or extent buffers held.
70 void noinline btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
74 for (i = 0; i < BTRFS_MAX_LEVEL; i++) {
79 btrfs_tree_unlock(p->nodes[i]);
82 free_extent_buffer(p->nodes[i]);
88 * safely gets a reference on the root node of a tree. A lock
89 * is not taken, so a concurrent writer may put a different node
90 * at the root of the tree. See btrfs_lock_root_node for the
93 * The extent buffer returned by this has a reference taken, so
94 * it won't disappear. It may stop being the root of the tree
95 * at any time because there are no locks held.
97 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
99 struct extent_buffer *eb;
100 spin_lock(&root->node_lock);
102 extent_buffer_get(eb);
103 spin_unlock(&root->node_lock);
107 /* loop around taking references on and locking the root node of the
108 * tree until you end up with a lock on the root. A locked buffer
109 * is returned, with a reference held.
111 struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
113 struct extent_buffer *eb;
116 eb = btrfs_root_node(root);
119 spin_lock(&root->node_lock);
120 if (eb == root->node) {
121 spin_unlock(&root->node_lock);
124 spin_unlock(&root->node_lock);
126 btrfs_tree_unlock(eb);
127 free_extent_buffer(eb);
132 /* cowonly root (everything not a reference counted cow subvolume), just get
133 * put onto a simple dirty list. transaction.c walks this to make sure they
134 * get properly updated on disk.
136 static void add_root_to_dirty_list(struct btrfs_root *root)
138 if (root->track_dirty && list_empty(&root->dirty_list)) {
139 list_add(&root->dirty_list,
140 &root->fs_info->dirty_cowonly_roots);
145 * used by snapshot creation to make a copy of a root for a tree with
146 * a given objectid. The buffer with the new root node is returned in
147 * cow_ret, and this func returns zero on success or a negative error code.
149 int btrfs_copy_root(struct btrfs_trans_handle *trans,
150 struct btrfs_root *root,
151 struct extent_buffer *buf,
152 struct extent_buffer **cow_ret, u64 new_root_objectid)
154 struct extent_buffer *cow;
158 struct btrfs_root *new_root;
160 new_root = kmalloc(sizeof(*new_root), GFP_NOFS);
164 memcpy(new_root, root, sizeof(*new_root));
165 new_root->root_key.objectid = new_root_objectid;
167 WARN_ON(root->ref_cows && trans->transid !=
168 root->fs_info->running_transaction->transid);
169 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
171 level = btrfs_header_level(buf);
172 nritems = btrfs_header_nritems(buf);
174 cow = btrfs_alloc_free_block(trans, new_root, buf->len, 0,
175 new_root_objectid, trans->transid,
176 level, buf->start, 0);
182 copy_extent_buffer(cow, buf, 0, 0, cow->len);
183 btrfs_set_header_bytenr(cow, cow->start);
184 btrfs_set_header_generation(cow, trans->transid);
185 btrfs_set_header_owner(cow, new_root_objectid);
186 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
188 write_extent_buffer(cow, root->fs_info->fsid,
189 (unsigned long)btrfs_header_fsid(cow),
192 WARN_ON(btrfs_header_generation(buf) > trans->transid);
193 ret = btrfs_inc_ref(trans, new_root, buf, cow, NULL);
199 btrfs_mark_buffer_dirty(cow);
205 * does the dirty work in cow of a single block. The parent block
206 * (if supplied) is updated to point to the new cow copy. The new
207 * buffer is marked dirty and returned locked. If you modify the block
208 * it needs to be marked dirty again.
210 * search_start -- an allocation hint for the new block
212 * empty_size -- a hint that you plan on doing more cow. This is the size in bytes
213 * the allocator should try to find free next to the block it returns. This is
214 * just a hint and may be ignored by the allocator.
216 * prealloc_dest -- if you have already reserved a destination for the cow,
217 * this uses that block instead of allocating a new one. btrfs_alloc_reserved_extent
218 * is used to finish the allocation.
220 static int noinline __btrfs_cow_block(struct btrfs_trans_handle *trans,
221 struct btrfs_root *root,
222 struct extent_buffer *buf,
223 struct extent_buffer *parent, int parent_slot,
224 struct extent_buffer **cow_ret,
225 u64 search_start, u64 empty_size,
229 struct extent_buffer *cow;
238 WARN_ON(!btrfs_tree_locked(buf));
241 parent_start = parent->start;
245 WARN_ON(root->ref_cows && trans->transid !=
246 root->fs_info->running_transaction->transid);
247 WARN_ON(root->ref_cows && trans->transid != root->last_trans);
249 level = btrfs_header_level(buf);
250 nritems = btrfs_header_nritems(buf);
253 struct btrfs_key ins;
255 ins.objectid = prealloc_dest;
256 ins.offset = buf->len;
257 ins.type = BTRFS_EXTENT_ITEM_KEY;
259 ret = btrfs_alloc_reserved_extent(trans, root, parent_start,
260 root->root_key.objectid,
261 trans->transid, level, &ins);
263 cow = btrfs_init_new_buffer(trans, root, prealloc_dest,
266 cow = btrfs_alloc_free_block(trans, root, buf->len,
268 root->root_key.objectid,
269 trans->transid, level,
270 search_start, empty_size);
275 copy_extent_buffer(cow, buf, 0, 0, cow->len);
276 btrfs_set_header_bytenr(cow, cow->start);
277 btrfs_set_header_generation(cow, trans->transid);
278 btrfs_set_header_owner(cow, root->root_key.objectid);
279 btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN);
281 write_extent_buffer(cow, root->fs_info->fsid,
282 (unsigned long)btrfs_header_fsid(cow),
285 WARN_ON(btrfs_header_generation(buf) > trans->transid);
286 if (btrfs_header_generation(buf) != trans->transid) {
288 ret = btrfs_inc_ref(trans, root, buf, cow, &nr_extents);
292 ret = btrfs_cache_ref(trans, root, buf, nr_extents);
294 } else if (btrfs_header_owner(buf) == BTRFS_TREE_RELOC_OBJECTID) {
296 * There are only two places that can drop reference to
297 * tree blocks owned by living reloc trees, one is here,
298 * the other place is btrfs_drop_subtree. In both places,
299 * we check reference count while tree block is locked.
300 * Furthermore, if reference count is one, it won't get
301 * increased by someone else.
304 ret = btrfs_lookup_extent_ref(trans, root, buf->start,
308 ret = btrfs_update_ref(trans, root, buf, cow,
310 clean_tree_block(trans, root, buf);
312 ret = btrfs_inc_ref(trans, root, buf, cow, NULL);
316 ret = btrfs_update_ref(trans, root, buf, cow, 0, nritems);
319 clean_tree_block(trans, root, buf);
322 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
323 ret = btrfs_reloc_tree_cache_ref(trans, root, cow, buf->start);
327 if (buf == root->node) {
328 WARN_ON(parent && parent != buf);
330 spin_lock(&root->node_lock);
332 extent_buffer_get(cow);
333 spin_unlock(&root->node_lock);
335 if (buf != root->commit_root) {
336 btrfs_free_extent(trans, root, buf->start,
337 buf->len, buf->start,
338 root->root_key.objectid,
339 btrfs_header_generation(buf),
342 free_extent_buffer(buf);
343 add_root_to_dirty_list(root);
345 btrfs_set_node_blockptr(parent, parent_slot,
347 WARN_ON(trans->transid == 0);
348 btrfs_set_node_ptr_generation(parent, parent_slot,
350 btrfs_mark_buffer_dirty(parent);
351 WARN_ON(btrfs_header_generation(parent) != trans->transid);
352 btrfs_free_extent(trans, root, buf->start, buf->len,
353 parent_start, btrfs_header_owner(parent),
354 btrfs_header_generation(parent), level, 1);
357 btrfs_tree_unlock(buf);
358 free_extent_buffer(buf);
359 btrfs_mark_buffer_dirty(cow);
365 * cows a single block, see __btrfs_cow_block for the real work.
366 * This version of it has extra checks so that a block isn't cow'd more than
367 * once per transaction, as long as it hasn't been written yet
369 int noinline btrfs_cow_block(struct btrfs_trans_handle *trans,
370 struct btrfs_root *root, struct extent_buffer *buf,
371 struct extent_buffer *parent, int parent_slot,
372 struct extent_buffer **cow_ret, u64 prealloc_dest)
377 if (trans->transaction != root->fs_info->running_transaction) {
378 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
379 root->fs_info->running_transaction->transid);
382 if (trans->transid != root->fs_info->generation) {
383 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
384 root->fs_info->generation);
388 spin_lock(&root->fs_info->hash_lock);
389 if (btrfs_header_generation(buf) == trans->transid &&
390 btrfs_header_owner(buf) == root->root_key.objectid &&
391 !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) {
393 spin_unlock(&root->fs_info->hash_lock);
394 WARN_ON(prealloc_dest);
397 spin_unlock(&root->fs_info->hash_lock);
398 search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1);
399 ret = __btrfs_cow_block(trans, root, buf, parent,
400 parent_slot, cow_ret, search_start, 0,
406 * helper function for defrag to decide if two blocks pointed to by a
407 * node are actually close by
409 static int close_blocks(u64 blocknr, u64 other, u32 blocksize)
411 if (blocknr < other && other - (blocknr + blocksize) < 32768)
413 if (blocknr > other && blocknr - (other + blocksize) < 32768)
419 * compare two keys in a memcmp fashion
421 static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2)
425 btrfs_disk_key_to_cpu(&k1, disk);
427 if (k1.objectid > k2->objectid)
429 if (k1.objectid < k2->objectid)
431 if (k1.type > k2->type)
433 if (k1.type < k2->type)
435 if (k1.offset > k2->offset)
437 if (k1.offset < k2->offset)
443 * same as comp_keys only with two btrfs_key's
445 static int comp_cpu_keys(struct btrfs_key *k1, struct btrfs_key *k2)
447 if (k1->objectid > k2->objectid)
449 if (k1->objectid < k2->objectid)
451 if (k1->type > k2->type)
453 if (k1->type < k2->type)
455 if (k1->offset > k2->offset)
457 if (k1->offset < k2->offset)
463 * this is used by the defrag code to go through all the
464 * leaves pointed to by a node and reallocate them so that
465 * disk order is close to key order
467 int btrfs_realloc_node(struct btrfs_trans_handle *trans,
468 struct btrfs_root *root, struct extent_buffer *parent,
469 int start_slot, int cache_only, u64 *last_ret,
470 struct btrfs_key *progress)
472 struct extent_buffer *cur;
475 u64 search_start = *last_ret;
485 int progress_passed = 0;
486 struct btrfs_disk_key disk_key;
488 parent_level = btrfs_header_level(parent);
489 if (cache_only && parent_level != 1)
492 if (trans->transaction != root->fs_info->running_transaction) {
493 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
494 root->fs_info->running_transaction->transid);
497 if (trans->transid != root->fs_info->generation) {
498 printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid,
499 root->fs_info->generation);
503 parent_nritems = btrfs_header_nritems(parent);
504 blocksize = btrfs_level_size(root, parent_level - 1);
505 end_slot = parent_nritems;
507 if (parent_nritems == 1)
510 for (i = start_slot; i < end_slot; i++) {
513 if (!parent->map_token) {
514 map_extent_buffer(parent,
515 btrfs_node_key_ptr_offset(i),
516 sizeof(struct btrfs_key_ptr),
517 &parent->map_token, &parent->kaddr,
518 &parent->map_start, &parent->map_len,
521 btrfs_node_key(parent, &disk_key, i);
522 if (!progress_passed && comp_keys(&disk_key, progress) < 0)
526 blocknr = btrfs_node_blockptr(parent, i);
527 gen = btrfs_node_ptr_generation(parent, i);
529 last_block = blocknr;
532 other = btrfs_node_blockptr(parent, i - 1);
533 close = close_blocks(blocknr, other, blocksize);
535 if (!close && i < end_slot - 2) {
536 other = btrfs_node_blockptr(parent, i + 1);
537 close = close_blocks(blocknr, other, blocksize);
540 last_block = blocknr;
543 if (parent->map_token) {
544 unmap_extent_buffer(parent, parent->map_token,
546 parent->map_token = NULL;
549 cur = btrfs_find_tree_block(root, blocknr, blocksize);
551 uptodate = btrfs_buffer_uptodate(cur, gen);
554 if (!cur || !uptodate) {
556 free_extent_buffer(cur);
560 cur = read_tree_block(root, blocknr,
562 } else if (!uptodate) {
563 btrfs_read_buffer(cur, gen);
566 if (search_start == 0)
567 search_start = last_block;
569 btrfs_tree_lock(cur);
570 err = __btrfs_cow_block(trans, root, cur, parent, i,
573 (end_slot - i) * blocksize), 0);
575 btrfs_tree_unlock(cur);
576 free_extent_buffer(cur);
579 search_start = cur->start;
580 last_block = cur->start;
581 *last_ret = search_start;
582 btrfs_tree_unlock(cur);
583 free_extent_buffer(cur);
585 if (parent->map_token) {
586 unmap_extent_buffer(parent, parent->map_token,
588 parent->map_token = NULL;
594 * The leaf data grows from end-to-front in the node.
595 * this returns the address of the start of the last item,
596 * which is the stop of the leaf data stack
598 static inline unsigned int leaf_data_end(struct btrfs_root *root,
599 struct extent_buffer *leaf)
601 u32 nr = btrfs_header_nritems(leaf);
603 return BTRFS_LEAF_DATA_SIZE(root);
604 return btrfs_item_offset_nr(leaf, nr - 1);
608 * extra debugging checks to make sure all the items in a key are
609 * well formed and in the proper order
611 static int check_node(struct btrfs_root *root, struct btrfs_path *path,
614 struct extent_buffer *parent = NULL;
615 struct extent_buffer *node = path->nodes[level];
616 struct btrfs_disk_key parent_key;
617 struct btrfs_disk_key node_key;
620 struct btrfs_key cpukey;
621 u32 nritems = btrfs_header_nritems(node);
623 if (path->nodes[level + 1])
624 parent = path->nodes[level + 1];
626 slot = path->slots[level];
627 BUG_ON(nritems == 0);
629 parent_slot = path->slots[level + 1];
630 btrfs_node_key(parent, &parent_key, parent_slot);
631 btrfs_node_key(node, &node_key, 0);
632 BUG_ON(memcmp(&parent_key, &node_key,
633 sizeof(struct btrfs_disk_key)));
634 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
635 btrfs_header_bytenr(node));
637 BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
639 btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
640 btrfs_node_key(node, &node_key, slot);
641 BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
643 if (slot < nritems - 1) {
644 btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
645 btrfs_node_key(node, &node_key, slot);
646 BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
652 * extra checking to make sure all the items in a leaf are
653 * well formed and in the proper order
655 static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
658 struct extent_buffer *leaf = path->nodes[level];
659 struct extent_buffer *parent = NULL;
661 struct btrfs_key cpukey;
662 struct btrfs_disk_key parent_key;
663 struct btrfs_disk_key leaf_key;
664 int slot = path->slots[0];
666 u32 nritems = btrfs_header_nritems(leaf);
668 if (path->nodes[level + 1])
669 parent = path->nodes[level + 1];
675 parent_slot = path->slots[level + 1];
676 btrfs_node_key(parent, &parent_key, parent_slot);
677 btrfs_item_key(leaf, &leaf_key, 0);
679 BUG_ON(memcmp(&parent_key, &leaf_key,
680 sizeof(struct btrfs_disk_key)));
681 BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
682 btrfs_header_bytenr(leaf));
685 for (i = 0; nritems > 1 && i < nritems - 2; i++) {
686 btrfs_item_key_to_cpu(leaf, &cpukey, i + 1);
687 btrfs_item_key(leaf, &leaf_key, i);
688 if (comp_keys(&leaf_key, &cpukey) >= 0) {
689 btrfs_print_leaf(root, leaf);
690 printk("slot %d offset bad key\n", i);
693 if (btrfs_item_offset_nr(leaf, i) !=
694 btrfs_item_end_nr(leaf, i + 1)) {
695 btrfs_print_leaf(root, leaf);
696 printk("slot %d offset bad\n", i);
700 if (btrfs_item_offset_nr(leaf, i) +
701 btrfs_item_size_nr(leaf, i) !=
702 BTRFS_LEAF_DATA_SIZE(root)) {
703 btrfs_print_leaf(root, leaf);
704 printk("slot %d first offset bad\n", i);
710 if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) {
711 btrfs_print_leaf(root, leaf);
712 printk("slot %d bad size \n", nritems - 1);
717 if (slot != 0 && slot < nritems - 1) {
718 btrfs_item_key(leaf, &leaf_key, slot);
719 btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
720 if (comp_keys(&leaf_key, &cpukey) <= 0) {
721 btrfs_print_leaf(root, leaf);
722 printk("slot %d offset bad key\n", slot);
725 if (btrfs_item_offset_nr(leaf, slot - 1) !=
726 btrfs_item_end_nr(leaf, slot)) {
727 btrfs_print_leaf(root, leaf);
728 printk("slot %d offset bad\n", slot);
732 if (slot < nritems - 1) {
733 btrfs_item_key(leaf, &leaf_key, slot);
734 btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
735 BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
736 if (btrfs_item_offset_nr(leaf, slot) !=
737 btrfs_item_end_nr(leaf, slot + 1)) {
738 btrfs_print_leaf(root, leaf);
739 printk("slot %d offset bad\n", slot);
743 BUG_ON(btrfs_item_offset_nr(leaf, 0) +
744 btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
748 static int noinline check_block(struct btrfs_root *root,
749 struct btrfs_path *path, int level)
753 if (btrfs_header_level(path->nodes[level]) != level)
754 printk("warning: bad level %Lu wanted %d found %d\n",
755 path->nodes[level]->start, level,
756 btrfs_header_level(path->nodes[level]));
757 found_start = btrfs_header_bytenr(path->nodes[level]);
758 if (found_start != path->nodes[level]->start) {
759 printk("warning: bad bytentr %Lu found %Lu\n",
760 path->nodes[level]->start, found_start);
763 struct extent_buffer *buf = path->nodes[level];
765 if (memcmp_extent_buffer(buf, root->fs_info->fsid,
766 (unsigned long)btrfs_header_fsid(buf),
768 printk("warning bad block %Lu\n", buf->start);
773 return check_leaf(root, path, level);
774 return check_node(root, path, level);
778 * search for key in the extent_buffer. The items start at offset p,
779 * and they are item_size apart. There are 'max' items in p.
781 * the slot in the array is returned via slot, and it points to
782 * the place where you would insert key if it is not found in
785 * slot may point to max if the key is bigger than all of the keys
787 static noinline int generic_bin_search(struct extent_buffer *eb,
789 int item_size, struct btrfs_key *key,
796 struct btrfs_disk_key *tmp = NULL;
797 struct btrfs_disk_key unaligned;
798 unsigned long offset;
799 char *map_token = NULL;
801 unsigned long map_start = 0;
802 unsigned long map_len = 0;
806 mid = (low + high) / 2;
807 offset = p + mid * item_size;
809 if (!map_token || offset < map_start ||
810 (offset + sizeof(struct btrfs_disk_key)) >
811 map_start + map_len) {
813 unmap_extent_buffer(eb, map_token, KM_USER0);
817 err = map_private_extent_buffer(eb, offset,
818 sizeof(struct btrfs_disk_key),
820 &map_start, &map_len, KM_USER0);
823 tmp = (struct btrfs_disk_key *)(kaddr + offset -
826 read_extent_buffer(eb, &unaligned,
827 offset, sizeof(unaligned));
832 tmp = (struct btrfs_disk_key *)(kaddr + offset -
835 ret = comp_keys(tmp, key);
844 unmap_extent_buffer(eb, map_token, KM_USER0);
850 unmap_extent_buffer(eb, map_token, KM_USER0);
855 * simple bin_search frontend that does the right thing for
858 static int bin_search(struct extent_buffer *eb, struct btrfs_key *key,
859 int level, int *slot)
862 return generic_bin_search(eb,
863 offsetof(struct btrfs_leaf, items),
864 sizeof(struct btrfs_item),
865 key, btrfs_header_nritems(eb),
868 return generic_bin_search(eb,
869 offsetof(struct btrfs_node, ptrs),
870 sizeof(struct btrfs_key_ptr),
871 key, btrfs_header_nritems(eb),
877 /* given a node and slot number, this reads the blocks it points to. The
878 * extent buffer is returned with a reference taken (but unlocked).
879 * NULL is returned on error.
881 static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root,
882 struct extent_buffer *parent, int slot)
884 int level = btrfs_header_level(parent);
887 if (slot >= btrfs_header_nritems(parent))
892 return read_tree_block(root, btrfs_node_blockptr(parent, slot),
893 btrfs_level_size(root, level - 1),
894 btrfs_node_ptr_generation(parent, slot));
898 * node level balancing, used to make sure nodes are in proper order for
899 * item deletion. We balance from the top down, so we have to make sure
900 * that a deletion won't leave an node completely empty later on.
902 static noinline int balance_level(struct btrfs_trans_handle *trans,
903 struct btrfs_root *root,
904 struct btrfs_path *path, int level)
906 struct extent_buffer *right = NULL;
907 struct extent_buffer *mid;
908 struct extent_buffer *left = NULL;
909 struct extent_buffer *parent = NULL;
913 int orig_slot = path->slots[level];
914 int err_on_enospc = 0;
920 mid = path->nodes[level];
921 WARN_ON(!path->locks[level]);
922 WARN_ON(btrfs_header_generation(mid) != trans->transid);
924 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
926 if (level < BTRFS_MAX_LEVEL - 1)
927 parent = path->nodes[level + 1];
928 pslot = path->slots[level + 1];
931 * deal with the case where there is only one pointer in the root
932 * by promoting the node below to a root
935 struct extent_buffer *child;
937 if (btrfs_header_nritems(mid) != 1)
940 /* promote the child to a root */
941 child = read_node_slot(root, mid, 0);
942 btrfs_tree_lock(child);
944 ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0);
947 spin_lock(&root->node_lock);
949 spin_unlock(&root->node_lock);
951 ret = btrfs_update_extent_ref(trans, root, child->start,
952 mid->start, child->start,
953 root->root_key.objectid,
954 trans->transid, level - 1);
957 add_root_to_dirty_list(root);
958 btrfs_tree_unlock(child);
959 path->locks[level] = 0;
960 path->nodes[level] = NULL;
961 clean_tree_block(trans, root, mid);
962 btrfs_tree_unlock(mid);
963 /* once for the path */
964 free_extent_buffer(mid);
965 ret = btrfs_free_extent(trans, root, mid->start, mid->len,
966 mid->start, root->root_key.objectid,
967 btrfs_header_generation(mid),
969 /* once for the root ptr */
970 free_extent_buffer(mid);
973 if (btrfs_header_nritems(mid) >
974 BTRFS_NODEPTRS_PER_BLOCK(root) / 4)
977 if (btrfs_header_nritems(mid) < 2)
980 left = read_node_slot(root, parent, pslot - 1);
982 btrfs_tree_lock(left);
983 wret = btrfs_cow_block(trans, root, left,
984 parent, pslot - 1, &left, 0);
990 right = read_node_slot(root, parent, pslot + 1);
992 btrfs_tree_lock(right);
993 wret = btrfs_cow_block(trans, root, right,
994 parent, pslot + 1, &right, 0);
1001 /* first, try to make some room in the middle buffer */
1003 orig_slot += btrfs_header_nritems(left);
1004 wret = push_node_left(trans, root, left, mid, 1);
1007 if (btrfs_header_nritems(mid) < 2)
1012 * then try to empty the right most buffer into the middle
1015 wret = push_node_left(trans, root, mid, right, 1);
1016 if (wret < 0 && wret != -ENOSPC)
1018 if (btrfs_header_nritems(right) == 0) {
1019 u64 bytenr = right->start;
1020 u64 generation = btrfs_header_generation(parent);
1021 u32 blocksize = right->len;
1023 clean_tree_block(trans, root, right);
1024 btrfs_tree_unlock(right);
1025 free_extent_buffer(right);
1027 wret = del_ptr(trans, root, path, level + 1, pslot +
1031 wret = btrfs_free_extent(trans, root, bytenr,
1032 blocksize, parent->start,
1033 btrfs_header_owner(parent),
1034 generation, level, 1);
1038 struct btrfs_disk_key right_key;
1039 btrfs_node_key(right, &right_key, 0);
1040 btrfs_set_node_key(parent, &right_key, pslot + 1);
1041 btrfs_mark_buffer_dirty(parent);
1044 if (btrfs_header_nritems(mid) == 1) {
1046 * we're not allowed to leave a node with one item in the
1047 * tree during a delete. A deletion from lower in the tree
1048 * could try to delete the only pointer in this node.
1049 * So, pull some keys from the left.
1050 * There has to be a left pointer at this point because
1051 * otherwise we would have pulled some pointers from the
1055 wret = balance_node_right(trans, root, mid, left);
1061 wret = push_node_left(trans, root, left, mid, 1);
1067 if (btrfs_header_nritems(mid) == 0) {
1068 /* we've managed to empty the middle node, drop it */
1069 u64 root_gen = btrfs_header_generation(parent);
1070 u64 bytenr = mid->start;
1071 u32 blocksize = mid->len;
1073 clean_tree_block(trans, root, mid);
1074 btrfs_tree_unlock(mid);
1075 free_extent_buffer(mid);
1077 wret = del_ptr(trans, root, path, level + 1, pslot);
1080 wret = btrfs_free_extent(trans, root, bytenr, blocksize,
1082 btrfs_header_owner(parent),
1083 root_gen, level, 1);
1087 /* update the parent key to reflect our changes */
1088 struct btrfs_disk_key mid_key;
1089 btrfs_node_key(mid, &mid_key, 0);
1090 btrfs_set_node_key(parent, &mid_key, pslot);
1091 btrfs_mark_buffer_dirty(parent);
1094 /* update the path */
1096 if (btrfs_header_nritems(left) > orig_slot) {
1097 extent_buffer_get(left);
1098 /* left was locked after cow */
1099 path->nodes[level] = left;
1100 path->slots[level + 1] -= 1;
1101 path->slots[level] = orig_slot;
1103 btrfs_tree_unlock(mid);
1104 free_extent_buffer(mid);
1107 orig_slot -= btrfs_header_nritems(left);
1108 path->slots[level] = orig_slot;
1111 /* double check we haven't messed things up */
1112 check_block(root, path, level);
1114 btrfs_node_blockptr(path->nodes[level], path->slots[level]))
1118 btrfs_tree_unlock(right);
1119 free_extent_buffer(right);
1122 if (path->nodes[level] != left)
1123 btrfs_tree_unlock(left);
1124 free_extent_buffer(left);
1129 /* Node balancing for insertion. Here we only split or push nodes around
1130 * when they are completely full. This is also done top down, so we
1131 * have to be pessimistic.
1133 static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans,
1134 struct btrfs_root *root,
1135 struct btrfs_path *path, int level)
1137 struct extent_buffer *right = NULL;
1138 struct extent_buffer *mid;
1139 struct extent_buffer *left = NULL;
1140 struct extent_buffer *parent = NULL;
1144 int orig_slot = path->slots[level];
1150 mid = path->nodes[level];
1151 WARN_ON(btrfs_header_generation(mid) != trans->transid);
1152 orig_ptr = btrfs_node_blockptr(mid, orig_slot);
1154 if (level < BTRFS_MAX_LEVEL - 1)
1155 parent = path->nodes[level + 1];
1156 pslot = path->slots[level + 1];
1161 left = read_node_slot(root, parent, pslot - 1);
1163 /* first, try to make some room in the middle buffer */
1167 btrfs_tree_lock(left);
1168 left_nr = btrfs_header_nritems(left);
1169 if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1172 ret = btrfs_cow_block(trans, root, left, parent,
1173 pslot - 1, &left, 0);
1177 wret = push_node_left(trans, root,
1184 struct btrfs_disk_key disk_key;
1185 orig_slot += left_nr;
1186 btrfs_node_key(mid, &disk_key, 0);
1187 btrfs_set_node_key(parent, &disk_key, pslot);
1188 btrfs_mark_buffer_dirty(parent);
1189 if (btrfs_header_nritems(left) > orig_slot) {
1190 path->nodes[level] = left;
1191 path->slots[level + 1] -= 1;
1192 path->slots[level] = orig_slot;
1193 btrfs_tree_unlock(mid);
1194 free_extent_buffer(mid);
1197 btrfs_header_nritems(left);
1198 path->slots[level] = orig_slot;
1199 btrfs_tree_unlock(left);
1200 free_extent_buffer(left);
1204 btrfs_tree_unlock(left);
1205 free_extent_buffer(left);
1207 right = read_node_slot(root, parent, pslot + 1);
1210 * then try to empty the right most buffer into the middle
1214 btrfs_tree_lock(right);
1215 right_nr = btrfs_header_nritems(right);
1216 if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) {
1219 ret = btrfs_cow_block(trans, root, right,
1225 wret = balance_node_right(trans, root,
1232 struct btrfs_disk_key disk_key;
1234 btrfs_node_key(right, &disk_key, 0);
1235 btrfs_set_node_key(parent, &disk_key, pslot + 1);
1236 btrfs_mark_buffer_dirty(parent);
1238 if (btrfs_header_nritems(mid) <= orig_slot) {
1239 path->nodes[level] = right;
1240 path->slots[level + 1] += 1;
1241 path->slots[level] = orig_slot -
1242 btrfs_header_nritems(mid);
1243 btrfs_tree_unlock(mid);
1244 free_extent_buffer(mid);
1246 btrfs_tree_unlock(right);
1247 free_extent_buffer(right);
1251 btrfs_tree_unlock(right);
1252 free_extent_buffer(right);
1258 * readahead one full node of leaves, finding things that are close
1259 * to the block in 'slot', and triggering ra on them.
1261 static noinline void reada_for_search(struct btrfs_root *root,
1262 struct btrfs_path *path,
1263 int level, int slot, u64 objectid)
1265 struct extent_buffer *node;
1266 struct btrfs_disk_key disk_key;
1272 int direction = path->reada;
1273 struct extent_buffer *eb;
1281 if (!path->nodes[level])
1284 node = path->nodes[level];
1286 search = btrfs_node_blockptr(node, slot);
1287 blocksize = btrfs_level_size(root, level - 1);
1288 eb = btrfs_find_tree_block(root, search, blocksize);
1290 free_extent_buffer(eb);
1294 highest_read = search;
1295 lowest_read = search;
1297 nritems = btrfs_header_nritems(node);
1300 if (direction < 0) {
1304 } else if (direction > 0) {
1309 if (path->reada < 0 && objectid) {
1310 btrfs_node_key(node, &disk_key, nr);
1311 if (btrfs_disk_key_objectid(&disk_key) != objectid)
1314 search = btrfs_node_blockptr(node, nr);
1315 if ((search >= lowest_read && search <= highest_read) ||
1316 (search < lowest_read && lowest_read - search <= 16384) ||
1317 (search > highest_read && search - highest_read <= 16384)) {
1318 readahead_tree_block(root, search, blocksize,
1319 btrfs_node_ptr_generation(node, nr));
1323 if (path->reada < 2 && (nread > (64 * 1024) || nscan > 32))
1325 if(nread > (256 * 1024) || nscan > 128)
1328 if (search < lowest_read)
1329 lowest_read = search;
1330 if (search > highest_read)
1331 highest_read = search;
1336 * when we walk down the tree, it is usually safe to unlock the higher layers in
1337 * the tree. The exceptions are when our path goes through slot 0, because operations
1338 * on the tree might require changing key pointers higher up in the tree.
1340 * callers might also have set path->keep_locks, which tells this code to
1341 * keep the lock if the path points to the last slot in the block. This is
1342 * part of walking through the tree, and selecting the next slot in the higher
1345 * lowest_unlock sets the lowest level in the tree we're allowed to unlock.
1346 * so if lowest_unlock is 1, level 0 won't be unlocked
1348 static noinline void unlock_up(struct btrfs_path *path, int level,
1352 int skip_level = level;
1354 struct extent_buffer *t;
1356 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1357 if (!path->nodes[i])
1359 if (!path->locks[i])
1361 if (!no_skips && path->slots[i] == 0) {
1365 if (!no_skips && path->keep_locks) {
1368 nritems = btrfs_header_nritems(t);
1369 if (nritems < 1 || path->slots[i] >= nritems - 1) {
1374 if (skip_level < i && i >= lowest_unlock)
1378 if (i >= lowest_unlock && i > skip_level && path->locks[i]) {
1379 btrfs_tree_unlock(t);
1386 * look for key in the tree. path is filled in with nodes along the way
1387 * if key is found, we return zero and you can find the item in the leaf
1388 * level of the path (level 0)
1390 * If the key isn't found, the path points to the slot where it should
1391 * be inserted, and 1 is returned. If there are other errors during the
1392 * search a negative error number is returned.
1394 * if ins_len > 0, nodes and leaves will be split as we walk down the
1395 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1398 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root
1399 *root, struct btrfs_key *key, struct btrfs_path *p, int
1402 struct extent_buffer *b;
1403 struct extent_buffer *tmp;
1407 int should_reada = p->reada;
1408 int lowest_unlock = 1;
1410 u8 lowest_level = 0;
1413 struct btrfs_key prealloc_block;
1415 lowest_level = p->lowest_level;
1416 WARN_ON(lowest_level && ins_len > 0);
1417 WARN_ON(p->nodes[0] != NULL);
1422 prealloc_block.objectid = 0;
1425 if (p->skip_locking)
1426 b = btrfs_root_node(root);
1428 b = btrfs_lock_root_node(root);
1431 level = btrfs_header_level(b);
1434 * setup the path here so we can release it under lock
1435 * contention with the cow code
1437 p->nodes[level] = b;
1438 if (!p->skip_locking)
1439 p->locks[level] = 1;
1444 /* is a cow on this block not required */
1445 spin_lock(&root->fs_info->hash_lock);
1446 if (btrfs_header_generation(b) == trans->transid &&
1447 btrfs_header_owner(b) == root->root_key.objectid &&
1448 !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) {
1449 spin_unlock(&root->fs_info->hash_lock);
1452 spin_unlock(&root->fs_info->hash_lock);
1454 /* ok, we have to cow, is our old prealloc the right
1457 if (prealloc_block.objectid &&
1458 prealloc_block.offset != b->len) {
1459 btrfs_free_reserved_extent(root,
1460 prealloc_block.objectid,
1461 prealloc_block.offset);
1462 prealloc_block.objectid = 0;
1466 * for higher level blocks, try not to allocate blocks
1467 * with the block and the parent locks held.
1469 if (level > 1 && !prealloc_block.objectid &&
1470 btrfs_path_lock_waiting(p, level)) {
1472 u64 hint = b->start;
1474 btrfs_release_path(root, p);
1475 ret = btrfs_reserve_extent(trans, root,
1478 &prealloc_block, 0);
1483 wret = btrfs_cow_block(trans, root, b,
1484 p->nodes[level + 1],
1485 p->slots[level + 1],
1486 &b, prealloc_block.objectid);
1487 prealloc_block.objectid = 0;
1489 free_extent_buffer(b);
1495 BUG_ON(!cow && ins_len);
1496 if (level != btrfs_header_level(b))
1498 level = btrfs_header_level(b);
1500 p->nodes[level] = b;
1501 if (!p->skip_locking)
1502 p->locks[level] = 1;
1504 ret = check_block(root, p, level);
1510 ret = bin_search(b, key, level, &slot);
1512 if (ret && slot > 0)
1514 p->slots[level] = slot;
1515 if ((p->search_for_split || ins_len > 0) &&
1516 btrfs_header_nritems(b) >=
1517 BTRFS_NODEPTRS_PER_BLOCK(root) - 3) {
1518 int sret = split_node(trans, root, p, level);
1524 b = p->nodes[level];
1525 slot = p->slots[level];
1526 } else if (ins_len < 0) {
1527 int sret = balance_level(trans, root, p,
1533 b = p->nodes[level];
1535 btrfs_release_path(NULL, p);
1538 slot = p->slots[level];
1539 BUG_ON(btrfs_header_nritems(b) == 1);
1541 unlock_up(p, level, lowest_unlock);
1543 /* this is only true while dropping a snapshot */
1544 if (level == lowest_level) {
1549 blocknr = btrfs_node_blockptr(b, slot);
1550 gen = btrfs_node_ptr_generation(b, slot);
1551 blocksize = btrfs_level_size(root, level - 1);
1553 tmp = btrfs_find_tree_block(root, blocknr, blocksize);
1554 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
1558 * reduce lock contention at high levels
1559 * of the btree by dropping locks before
1563 btrfs_release_path(NULL, p);
1565 free_extent_buffer(tmp);
1567 reada_for_search(root, p,
1571 tmp = read_tree_block(root, blocknr,
1574 free_extent_buffer(tmp);
1578 free_extent_buffer(tmp);
1580 reada_for_search(root, p,
1583 b = read_node_slot(root, b, slot);
1586 if (!p->skip_locking)
1589 p->slots[level] = slot;
1591 btrfs_leaf_free_space(root, b) < ins_len) {
1592 int sret = split_leaf(trans, root, key,
1593 p, ins_len, ret == 0);
1600 if (!p->search_for_split)
1601 unlock_up(p, level, lowest_unlock);
1607 if (prealloc_block.objectid) {
1608 btrfs_free_reserved_extent(root,
1609 prealloc_block.objectid,
1610 prealloc_block.offset);
1616 int btrfs_merge_path(struct btrfs_trans_handle *trans,
1617 struct btrfs_root *root,
1618 struct btrfs_key *node_keys,
1619 u64 *nodes, int lowest_level)
1621 struct extent_buffer *eb;
1622 struct extent_buffer *parent;
1623 struct btrfs_key key;
1632 eb = btrfs_lock_root_node(root);
1633 ret = btrfs_cow_block(trans, root, eb, NULL, 0, &eb, 0);
1638 level = btrfs_header_level(parent);
1639 if (level == 0 || level <= lowest_level)
1642 ret = bin_search(parent, &node_keys[lowest_level], level,
1644 if (ret && slot > 0)
1647 bytenr = btrfs_node_blockptr(parent, slot);
1648 if (nodes[level - 1] == bytenr)
1651 blocksize = btrfs_level_size(root, level - 1);
1652 generation = btrfs_node_ptr_generation(parent, slot);
1653 btrfs_node_key_to_cpu(eb, &key, slot);
1654 key_match = !memcmp(&key, &node_keys[level - 1], sizeof(key));
1656 if (generation == trans->transid) {
1657 eb = read_tree_block(root, bytenr, blocksize,
1659 btrfs_tree_lock(eb);
1663 * if node keys match and node pointer hasn't been modified
1664 * in the running transaction, we can merge the path. for
1665 * blocks owened by reloc trees, the node pointer check is
1666 * skipped, this is because these blocks are fully controlled
1667 * by the space balance code, no one else can modify them.
1669 if (!nodes[level - 1] || !key_match ||
1670 (generation == trans->transid &&
1671 btrfs_header_owner(eb) != BTRFS_TREE_RELOC_OBJECTID)) {
1672 if (level == 1 || level == lowest_level + 1) {
1673 if (generation == trans->transid) {
1674 btrfs_tree_unlock(eb);
1675 free_extent_buffer(eb);
1680 if (generation != trans->transid) {
1681 eb = read_tree_block(root, bytenr, blocksize,
1683 btrfs_tree_lock(eb);
1686 ret = btrfs_cow_block(trans, root, eb, parent, slot,
1690 if (root->root_key.objectid ==
1691 BTRFS_TREE_RELOC_OBJECTID) {
1692 if (!nodes[level - 1]) {
1693 nodes[level - 1] = eb->start;
1694 memcpy(&node_keys[level - 1], &key,
1695 sizeof(node_keys[0]));
1701 btrfs_tree_unlock(parent);
1702 free_extent_buffer(parent);
1707 btrfs_set_node_blockptr(parent, slot, nodes[level - 1]);
1708 btrfs_set_node_ptr_generation(parent, slot, trans->transid);
1709 btrfs_mark_buffer_dirty(parent);
1711 ret = btrfs_inc_extent_ref(trans, root,
1713 blocksize, parent->start,
1714 btrfs_header_owner(parent),
1715 btrfs_header_generation(parent),
1720 * If the block was created in the running transaction,
1721 * it's possible this is the last reference to it, so we
1722 * should drop the subtree.
1724 if (generation == trans->transid) {
1725 ret = btrfs_drop_subtree(trans, root, eb, parent);
1727 btrfs_tree_unlock(eb);
1728 free_extent_buffer(eb);
1730 ret = btrfs_free_extent(trans, root, bytenr,
1731 blocksize, parent->start,
1732 btrfs_header_owner(parent),
1733 btrfs_header_generation(parent),
1739 btrfs_tree_unlock(parent);
1740 free_extent_buffer(parent);
1745 * adjust the pointers going up the tree, starting at level
1746 * making sure the right key of each node is points to 'key'.
1747 * This is used after shifting pointers to the left, so it stops
1748 * fixing up pointers when a given leaf/node is not in slot 0 of the
1751 * If this fails to write a tree block, it returns -1, but continues
1752 * fixing up the blocks in ram so the tree is consistent.
1754 static int fixup_low_keys(struct btrfs_trans_handle *trans,
1755 struct btrfs_root *root, struct btrfs_path *path,
1756 struct btrfs_disk_key *key, int level)
1760 struct extent_buffer *t;
1762 for (i = level; i < BTRFS_MAX_LEVEL; i++) {
1763 int tslot = path->slots[i];
1764 if (!path->nodes[i])
1767 btrfs_set_node_key(t, key, tslot);
1768 btrfs_mark_buffer_dirty(path->nodes[i]);
1778 * This function isn't completely safe. It's the caller's responsibility
1779 * that the new key won't break the order
1781 int btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
1782 struct btrfs_root *root, struct btrfs_path *path,
1783 struct btrfs_key *new_key)
1785 struct btrfs_disk_key disk_key;
1786 struct extent_buffer *eb;
1789 eb = path->nodes[0];
1790 slot = path->slots[0];
1792 btrfs_item_key(eb, &disk_key, slot - 1);
1793 if (comp_keys(&disk_key, new_key) >= 0)
1796 if (slot < btrfs_header_nritems(eb) - 1) {
1797 btrfs_item_key(eb, &disk_key, slot + 1);
1798 if (comp_keys(&disk_key, new_key) <= 0)
1802 btrfs_cpu_key_to_disk(&disk_key, new_key);
1803 btrfs_set_item_key(eb, &disk_key, slot);
1804 btrfs_mark_buffer_dirty(eb);
1806 fixup_low_keys(trans, root, path, &disk_key, 1);
1811 * try to push data from one node into the next node left in the
1814 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1815 * error, and > 0 if there was no room in the left hand block.
1817 static int push_node_left(struct btrfs_trans_handle *trans,
1818 struct btrfs_root *root, struct extent_buffer *dst,
1819 struct extent_buffer *src, int empty)
1826 src_nritems = btrfs_header_nritems(src);
1827 dst_nritems = btrfs_header_nritems(dst);
1828 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1829 WARN_ON(btrfs_header_generation(src) != trans->transid);
1830 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1832 if (!empty && src_nritems <= 8)
1835 if (push_items <= 0) {
1840 push_items = min(src_nritems, push_items);
1841 if (push_items < src_nritems) {
1842 /* leave at least 8 pointers in the node if
1843 * we aren't going to empty it
1845 if (src_nritems - push_items < 8) {
1846 if (push_items <= 8)
1852 push_items = min(src_nritems - 8, push_items);
1854 copy_extent_buffer(dst, src,
1855 btrfs_node_key_ptr_offset(dst_nritems),
1856 btrfs_node_key_ptr_offset(0),
1857 push_items * sizeof(struct btrfs_key_ptr));
1859 if (push_items < src_nritems) {
1860 memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0),
1861 btrfs_node_key_ptr_offset(push_items),
1862 (src_nritems - push_items) *
1863 sizeof(struct btrfs_key_ptr));
1865 btrfs_set_header_nritems(src, src_nritems - push_items);
1866 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1867 btrfs_mark_buffer_dirty(src);
1868 btrfs_mark_buffer_dirty(dst);
1870 ret = btrfs_update_ref(trans, root, src, dst, dst_nritems, push_items);
1877 * try to push data from one node into the next node right in the
1880 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1881 * error, and > 0 if there was no room in the right hand block.
1883 * this will only push up to 1/2 the contents of the left node over
1885 static int balance_node_right(struct btrfs_trans_handle *trans,
1886 struct btrfs_root *root,
1887 struct extent_buffer *dst,
1888 struct extent_buffer *src)
1896 WARN_ON(btrfs_header_generation(src) != trans->transid);
1897 WARN_ON(btrfs_header_generation(dst) != trans->transid);
1899 src_nritems = btrfs_header_nritems(src);
1900 dst_nritems = btrfs_header_nritems(dst);
1901 push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems;
1902 if (push_items <= 0) {
1906 if (src_nritems < 4) {
1910 max_push = src_nritems / 2 + 1;
1911 /* don't try to empty the node */
1912 if (max_push >= src_nritems) {
1916 if (max_push < push_items)
1917 push_items = max_push;
1919 memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items),
1920 btrfs_node_key_ptr_offset(0),
1922 sizeof(struct btrfs_key_ptr));
1924 copy_extent_buffer(dst, src,
1925 btrfs_node_key_ptr_offset(0),
1926 btrfs_node_key_ptr_offset(src_nritems - push_items),
1927 push_items * sizeof(struct btrfs_key_ptr));
1929 btrfs_set_header_nritems(src, src_nritems - push_items);
1930 btrfs_set_header_nritems(dst, dst_nritems + push_items);
1932 btrfs_mark_buffer_dirty(src);
1933 btrfs_mark_buffer_dirty(dst);
1935 ret = btrfs_update_ref(trans, root, src, dst, 0, push_items);
1942 * helper function to insert a new root level in the tree.
1943 * A new node is allocated, and a single item is inserted to
1944 * point to the existing root
1946 * returns zero on success or < 0 on failure.
1948 static int noinline insert_new_root(struct btrfs_trans_handle *trans,
1949 struct btrfs_root *root,
1950 struct btrfs_path *path, int level)
1953 struct extent_buffer *lower;
1954 struct extent_buffer *c;
1955 struct extent_buffer *old;
1956 struct btrfs_disk_key lower_key;
1959 BUG_ON(path->nodes[level]);
1960 BUG_ON(path->nodes[level-1] != root->node);
1962 lower = path->nodes[level-1];
1964 btrfs_item_key(lower, &lower_key, 0);
1966 btrfs_node_key(lower, &lower_key, 0);
1968 c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
1969 root->root_key.objectid, trans->transid,
1970 level, root->node->start, 0);
1974 memset_extent_buffer(c, 0, 0, root->nodesize);
1975 btrfs_set_header_nritems(c, 1);
1976 btrfs_set_header_level(c, level);
1977 btrfs_set_header_bytenr(c, c->start);
1978 btrfs_set_header_generation(c, trans->transid);
1979 btrfs_set_header_owner(c, root->root_key.objectid);
1981 write_extent_buffer(c, root->fs_info->fsid,
1982 (unsigned long)btrfs_header_fsid(c),
1985 write_extent_buffer(c, root->fs_info->chunk_tree_uuid,
1986 (unsigned long)btrfs_header_chunk_tree_uuid(c),
1989 btrfs_set_node_key(c, &lower_key, 0);
1990 btrfs_set_node_blockptr(c, 0, lower->start);
1991 lower_gen = btrfs_header_generation(lower);
1992 WARN_ON(lower_gen != trans->transid);
1994 btrfs_set_node_ptr_generation(c, 0, lower_gen);
1996 btrfs_mark_buffer_dirty(c);
1998 spin_lock(&root->node_lock);
2001 spin_unlock(&root->node_lock);
2003 ret = btrfs_update_extent_ref(trans, root, lower->start,
2004 lower->start, c->start,
2005 root->root_key.objectid,
2006 trans->transid, level - 1);
2009 /* the super has an extra ref to root->node */
2010 free_extent_buffer(old);
2012 add_root_to_dirty_list(root);
2013 extent_buffer_get(c);
2014 path->nodes[level] = c;
2015 path->locks[level] = 1;
2016 path->slots[level] = 0;
2021 * worker function to insert a single pointer in a node.
2022 * the node should have enough room for the pointer already
2024 * slot and level indicate where you want the key to go, and
2025 * blocknr is the block the key points to.
2027 * returns zero on success and < 0 on any error
2029 static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root
2030 *root, struct btrfs_path *path, struct btrfs_disk_key
2031 *key, u64 bytenr, int slot, int level)
2033 struct extent_buffer *lower;
2036 BUG_ON(!path->nodes[level]);
2037 lower = path->nodes[level];
2038 nritems = btrfs_header_nritems(lower);
2041 if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root))
2043 if (slot != nritems) {
2044 memmove_extent_buffer(lower,
2045 btrfs_node_key_ptr_offset(slot + 1),
2046 btrfs_node_key_ptr_offset(slot),
2047 (nritems - slot) * sizeof(struct btrfs_key_ptr));
2049 btrfs_set_node_key(lower, key, slot);
2050 btrfs_set_node_blockptr(lower, slot, bytenr);
2051 WARN_ON(trans->transid == 0);
2052 btrfs_set_node_ptr_generation(lower, slot, trans->transid);
2053 btrfs_set_header_nritems(lower, nritems + 1);
2054 btrfs_mark_buffer_dirty(lower);
2059 * split the node at the specified level in path in two.
2060 * The path is corrected to point to the appropriate node after the split
2062 * Before splitting this tries to make some room in the node by pushing
2063 * left and right, if either one works, it returns right away.
2065 * returns 0 on success and < 0 on failure
2067 static noinline int split_node(struct btrfs_trans_handle *trans,
2068 struct btrfs_root *root,
2069 struct btrfs_path *path, int level)
2071 struct extent_buffer *c;
2072 struct extent_buffer *split;
2073 struct btrfs_disk_key disk_key;
2079 c = path->nodes[level];
2080 WARN_ON(btrfs_header_generation(c) != trans->transid);
2081 if (c == root->node) {
2082 /* trying to split the root, lets make a new one */
2083 ret = insert_new_root(trans, root, path, level + 1);
2087 ret = push_nodes_for_insert(trans, root, path, level);
2088 c = path->nodes[level];
2089 if (!ret && btrfs_header_nritems(c) <
2090 BTRFS_NODEPTRS_PER_BLOCK(root) - 3)
2096 c_nritems = btrfs_header_nritems(c);
2098 split = btrfs_alloc_free_block(trans, root, root->nodesize,
2099 path->nodes[level + 1]->start,
2100 root->root_key.objectid,
2101 trans->transid, level, c->start, 0);
2103 return PTR_ERR(split);
2105 btrfs_set_header_flags(split, btrfs_header_flags(c));
2106 btrfs_set_header_level(split, btrfs_header_level(c));
2107 btrfs_set_header_bytenr(split, split->start);
2108 btrfs_set_header_generation(split, trans->transid);
2109 btrfs_set_header_owner(split, root->root_key.objectid);
2110 btrfs_set_header_flags(split, 0);
2111 write_extent_buffer(split, root->fs_info->fsid,
2112 (unsigned long)btrfs_header_fsid(split),
2114 write_extent_buffer(split, root->fs_info->chunk_tree_uuid,
2115 (unsigned long)btrfs_header_chunk_tree_uuid(split),
2118 mid = (c_nritems + 1) / 2;
2120 copy_extent_buffer(split, c,
2121 btrfs_node_key_ptr_offset(0),
2122 btrfs_node_key_ptr_offset(mid),
2123 (c_nritems - mid) * sizeof(struct btrfs_key_ptr));
2124 btrfs_set_header_nritems(split, c_nritems - mid);
2125 btrfs_set_header_nritems(c, mid);
2128 btrfs_mark_buffer_dirty(c);
2129 btrfs_mark_buffer_dirty(split);
2131 btrfs_node_key(split, &disk_key, 0);
2132 wret = insert_ptr(trans, root, path, &disk_key, split->start,
2133 path->slots[level + 1] + 1,
2138 ret = btrfs_update_ref(trans, root, c, split, 0, c_nritems - mid);
2141 if (path->slots[level] >= mid) {
2142 path->slots[level] -= mid;
2143 btrfs_tree_unlock(c);
2144 free_extent_buffer(c);
2145 path->nodes[level] = split;
2146 path->slots[level + 1] += 1;
2148 btrfs_tree_unlock(split);
2149 free_extent_buffer(split);
2155 * how many bytes are required to store the items in a leaf. start
2156 * and nr indicate which items in the leaf to check. This totals up the
2157 * space used both by the item structs and the item data
2159 static int leaf_space_used(struct extent_buffer *l, int start, int nr)
2162 int nritems = btrfs_header_nritems(l);
2163 int end = min(nritems, start + nr) - 1;
2167 data_len = btrfs_item_end_nr(l, start);
2168 data_len = data_len - btrfs_item_offset_nr(l, end);
2169 data_len += sizeof(struct btrfs_item) * nr;
2170 WARN_ON(data_len < 0);
2175 * The space between the end of the leaf items and
2176 * the start of the leaf data. IOW, how much room
2177 * the leaf has left for both items and data
2179 int noinline btrfs_leaf_free_space(struct btrfs_root *root,
2180 struct extent_buffer *leaf)
2182 int nritems = btrfs_header_nritems(leaf);
2184 ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems);
2186 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
2187 ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root),
2188 leaf_space_used(leaf, 0, nritems), nritems);
2194 * push some data in the path leaf to the right, trying to free up at
2195 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2197 * returns 1 if the push failed because the other node didn't have enough
2198 * room, 0 if everything worked out and < 0 if there were major errors.
2200 static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
2201 *root, struct btrfs_path *path, int data_size,
2204 struct extent_buffer *left = path->nodes[0];
2205 struct extent_buffer *right;
2206 struct extent_buffer *upper;
2207 struct btrfs_disk_key disk_key;
2213 struct btrfs_item *item;
2221 slot = path->slots[1];
2222 if (!path->nodes[1]) {
2225 upper = path->nodes[1];
2226 if (slot >= btrfs_header_nritems(upper) - 1)
2229 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
2231 right = read_node_slot(root, upper, slot + 1);
2232 btrfs_tree_lock(right);
2233 free_space = btrfs_leaf_free_space(root, right);
2234 if (free_space < data_size)
2237 /* cow and double check */
2238 ret = btrfs_cow_block(trans, root, right, upper,
2239 slot + 1, &right, 0);
2243 free_space = btrfs_leaf_free_space(root, right);
2244 if (free_space < data_size)
2247 left_nritems = btrfs_header_nritems(left);
2248 if (left_nritems == 0)
2256 if (path->slots[0] >= left_nritems)
2257 push_space += data_size;
2259 i = left_nritems - 1;
2261 item = btrfs_item_nr(left, i);
2263 if (!empty && push_items > 0) {
2264 if (path->slots[0] > i)
2266 if (path->slots[0] == i) {
2267 int space = btrfs_leaf_free_space(root, left);
2268 if (space + push_space * 2 > free_space)
2273 if (path->slots[0] == i)
2274 push_space += data_size;
2276 if (!left->map_token) {
2277 map_extent_buffer(left, (unsigned long)item,
2278 sizeof(struct btrfs_item),
2279 &left->map_token, &left->kaddr,
2280 &left->map_start, &left->map_len,
2284 this_item_size = btrfs_item_size(left, item);
2285 if (this_item_size + sizeof(*item) + push_space > free_space)
2289 push_space += this_item_size + sizeof(*item);
2294 if (left->map_token) {
2295 unmap_extent_buffer(left, left->map_token, KM_USER1);
2296 left->map_token = NULL;
2299 if (push_items == 0)
2302 if (!empty && push_items == left_nritems)
2305 /* push left to right */
2306 right_nritems = btrfs_header_nritems(right);
2308 push_space = btrfs_item_end_nr(left, left_nritems - push_items);
2309 push_space -= leaf_data_end(root, left);
2311 /* make room in the right data area */
2312 data_end = leaf_data_end(root, right);
2313 memmove_extent_buffer(right,
2314 btrfs_leaf_data(right) + data_end - push_space,
2315 btrfs_leaf_data(right) + data_end,
2316 BTRFS_LEAF_DATA_SIZE(root) - data_end);
2318 /* copy from the left data area */
2319 copy_extent_buffer(right, left, btrfs_leaf_data(right) +
2320 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2321 btrfs_leaf_data(left) + leaf_data_end(root, left),
2324 memmove_extent_buffer(right, btrfs_item_nr_offset(push_items),
2325 btrfs_item_nr_offset(0),
2326 right_nritems * sizeof(struct btrfs_item));
2328 /* copy the items from left to right */
2329 copy_extent_buffer(right, left, btrfs_item_nr_offset(0),
2330 btrfs_item_nr_offset(left_nritems - push_items),
2331 push_items * sizeof(struct btrfs_item));
2333 /* update the item pointers */
2334 right_nritems += push_items;
2335 btrfs_set_header_nritems(right, right_nritems);
2336 push_space = BTRFS_LEAF_DATA_SIZE(root);
2337 for (i = 0; i < right_nritems; i++) {
2338 item = btrfs_item_nr(right, i);
2339 if (!right->map_token) {
2340 map_extent_buffer(right, (unsigned long)item,
2341 sizeof(struct btrfs_item),
2342 &right->map_token, &right->kaddr,
2343 &right->map_start, &right->map_len,
2346 push_space -= btrfs_item_size(right, item);
2347 btrfs_set_item_offset(right, item, push_space);
2350 if (right->map_token) {
2351 unmap_extent_buffer(right, right->map_token, KM_USER1);
2352 right->map_token = NULL;
2354 left_nritems -= push_items;
2355 btrfs_set_header_nritems(left, left_nritems);
2358 btrfs_mark_buffer_dirty(left);
2359 btrfs_mark_buffer_dirty(right);
2361 ret = btrfs_update_ref(trans, root, left, right, 0, push_items);
2364 btrfs_item_key(right, &disk_key, 0);
2365 btrfs_set_node_key(upper, &disk_key, slot + 1);
2366 btrfs_mark_buffer_dirty(upper);
2368 /* then fixup the leaf pointer in the path */
2369 if (path->slots[0] >= left_nritems) {
2370 path->slots[0] -= left_nritems;
2371 if (btrfs_header_nritems(path->nodes[0]) == 0)
2372 clean_tree_block(trans, root, path->nodes[0]);
2373 btrfs_tree_unlock(path->nodes[0]);
2374 free_extent_buffer(path->nodes[0]);
2375 path->nodes[0] = right;
2376 path->slots[1] += 1;
2378 btrfs_tree_unlock(right);
2379 free_extent_buffer(right);
2384 btrfs_tree_unlock(right);
2385 free_extent_buffer(right);
2390 * push some data in the path leaf to the left, trying to free up at
2391 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2393 static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
2394 *root, struct btrfs_path *path, int data_size,
2397 struct btrfs_disk_key disk_key;
2398 struct extent_buffer *right = path->nodes[0];
2399 struct extent_buffer *left;
2405 struct btrfs_item *item;
2406 u32 old_left_nritems;
2412 u32 old_left_item_size;
2414 slot = path->slots[1];
2417 if (!path->nodes[1])
2420 right_nritems = btrfs_header_nritems(right);
2421 if (right_nritems == 0) {
2425 WARN_ON(!btrfs_tree_locked(path->nodes[1]));
2427 left = read_node_slot(root, path->nodes[1], slot - 1);
2428 btrfs_tree_lock(left);
2429 free_space = btrfs_leaf_free_space(root, left);
2430 if (free_space < data_size) {
2435 /* cow and double check */
2436 ret = btrfs_cow_block(trans, root, left,
2437 path->nodes[1], slot - 1, &left, 0);
2439 /* we hit -ENOSPC, but it isn't fatal here */
2444 free_space = btrfs_leaf_free_space(root, left);
2445 if (free_space < data_size) {
2453 nr = right_nritems - 1;
2455 for (i = 0; i < nr; i++) {
2456 item = btrfs_item_nr(right, i);
2457 if (!right->map_token) {
2458 map_extent_buffer(right, (unsigned long)item,
2459 sizeof(struct btrfs_item),
2460 &right->map_token, &right->kaddr,
2461 &right->map_start, &right->map_len,
2465 if (!empty && push_items > 0) {
2466 if (path->slots[0] < i)
2468 if (path->slots[0] == i) {
2469 int space = btrfs_leaf_free_space(root, right);
2470 if (space + push_space * 2 > free_space)
2475 if (path->slots[0] == i)
2476 push_space += data_size;
2478 this_item_size = btrfs_item_size(right, item);
2479 if (this_item_size + sizeof(*item) + push_space > free_space)
2483 push_space += this_item_size + sizeof(*item);
2486 if (right->map_token) {
2487 unmap_extent_buffer(right, right->map_token, KM_USER1);
2488 right->map_token = NULL;
2491 if (push_items == 0) {
2495 if (!empty && push_items == btrfs_header_nritems(right))
2498 /* push data from right to left */
2499 copy_extent_buffer(left, right,
2500 btrfs_item_nr_offset(btrfs_header_nritems(left)),
2501 btrfs_item_nr_offset(0),
2502 push_items * sizeof(struct btrfs_item));
2504 push_space = BTRFS_LEAF_DATA_SIZE(root) -
2505 btrfs_item_offset_nr(right, push_items -1);
2507 copy_extent_buffer(left, right, btrfs_leaf_data(left) +
2508 leaf_data_end(root, left) - push_space,
2509 btrfs_leaf_data(right) +
2510 btrfs_item_offset_nr(right, push_items - 1),
2512 old_left_nritems = btrfs_header_nritems(left);
2513 BUG_ON(old_left_nritems <= 0);
2515 old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1);
2516 for (i = old_left_nritems; i < old_left_nritems + push_items; i++) {
2519 item = btrfs_item_nr(left, i);
2520 if (!left->map_token) {
2521 map_extent_buffer(left, (unsigned long)item,
2522 sizeof(struct btrfs_item),
2523 &left->map_token, &left->kaddr,
2524 &left->map_start, &left->map_len,
2528 ioff = btrfs_item_offset(left, item);
2529 btrfs_set_item_offset(left, item,
2530 ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size));
2532 btrfs_set_header_nritems(left, old_left_nritems + push_items);
2533 if (left->map_token) {
2534 unmap_extent_buffer(left, left->map_token, KM_USER1);
2535 left->map_token = NULL;
2538 /* fixup right node */
2539 if (push_items > right_nritems) {
2540 printk("push items %d nr %u\n", push_items, right_nritems);
2544 if (push_items < right_nritems) {
2545 push_space = btrfs_item_offset_nr(right, push_items - 1) -
2546 leaf_data_end(root, right);
2547 memmove_extent_buffer(right, btrfs_leaf_data(right) +
2548 BTRFS_LEAF_DATA_SIZE(root) - push_space,
2549 btrfs_leaf_data(right) +
2550 leaf_data_end(root, right), push_space);
2552 memmove_extent_buffer(right, btrfs_item_nr_offset(0),
2553 btrfs_item_nr_offset(push_items),
2554 (btrfs_header_nritems(right) - push_items) *
2555 sizeof(struct btrfs_item));
2557 right_nritems -= push_items;
2558 btrfs_set_header_nritems(right, right_nritems);
2559 push_space = BTRFS_LEAF_DATA_SIZE(root);
2560 for (i = 0; i < right_nritems; i++) {
2561 item = btrfs_item_nr(right, i);
2563 if (!right->map_token) {
2564 map_extent_buffer(right, (unsigned long)item,
2565 sizeof(struct btrfs_item),
2566 &right->map_token, &right->kaddr,
2567 &right->map_start, &right->map_len,
2571 push_space = push_space - btrfs_item_size(right, item);
2572 btrfs_set_item_offset(right, item, push_space);
2574 if (right->map_token) {
2575 unmap_extent_buffer(right, right->map_token, KM_USER1);
2576 right->map_token = NULL;
2579 btrfs_mark_buffer_dirty(left);
2581 btrfs_mark_buffer_dirty(right);
2583 ret = btrfs_update_ref(trans, root, right, left,
2584 old_left_nritems, push_items);
2587 btrfs_item_key(right, &disk_key, 0);
2588 wret = fixup_low_keys(trans, root, path, &disk_key, 1);
2592 /* then fixup the leaf pointer in the path */
2593 if (path->slots[0] < push_items) {
2594 path->slots[0] += old_left_nritems;
2595 if (btrfs_header_nritems(path->nodes[0]) == 0)
2596 clean_tree_block(trans, root, path->nodes[0]);
2597 btrfs_tree_unlock(path->nodes[0]);
2598 free_extent_buffer(path->nodes[0]);
2599 path->nodes[0] = left;
2600 path->slots[1] -= 1;
2602 btrfs_tree_unlock(left);
2603 free_extent_buffer(left);
2604 path->slots[0] -= push_items;
2606 BUG_ON(path->slots[0] < 0);
2609 btrfs_tree_unlock(left);
2610 free_extent_buffer(left);
2615 * split the path's leaf in two, making sure there is at least data_size
2616 * available for the resulting leaf level of the path.
2618 * returns 0 if all went well and < 0 on failure.
2620 static noinline int split_leaf(struct btrfs_trans_handle *trans,
2621 struct btrfs_root *root,
2622 struct btrfs_key *ins_key,
2623 struct btrfs_path *path, int data_size,
2626 struct extent_buffer *l;
2630 struct extent_buffer *right;
2637 int num_doubles = 0;
2638 struct btrfs_disk_key disk_key;
2640 /* first try to make some room by pushing left and right */
2641 if (data_size && ins_key->type != BTRFS_DIR_ITEM_KEY) {
2642 wret = push_leaf_right(trans, root, path, data_size, 0);
2647 wret = push_leaf_left(trans, root, path, data_size, 0);
2653 /* did the pushes work? */
2654 if (btrfs_leaf_free_space(root, l) >= data_size)
2658 if (!path->nodes[1]) {
2659 ret = insert_new_root(trans, root, path, 1);
2666 slot = path->slots[0];
2667 nritems = btrfs_header_nritems(l);
2668 mid = (nritems + 1)/ 2;
2670 right = btrfs_alloc_free_block(trans, root, root->leafsize,
2671 path->nodes[1]->start,
2672 root->root_key.objectid,
2673 trans->transid, 0, l->start, 0);
2674 if (IS_ERR(right)) {
2676 return PTR_ERR(right);
2679 memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header));
2680 btrfs_set_header_bytenr(right, right->start);
2681 btrfs_set_header_generation(right, trans->transid);
2682 btrfs_set_header_owner(right, root->root_key.objectid);
2683 btrfs_set_header_level(right, 0);
2684 write_extent_buffer(right, root->fs_info->fsid,
2685 (unsigned long)btrfs_header_fsid(right),
2688 write_extent_buffer(right, root->fs_info->chunk_tree_uuid,
2689 (unsigned long)btrfs_header_chunk_tree_uuid(right),
2693 leaf_space_used(l, mid, nritems - mid) + data_size >
2694 BTRFS_LEAF_DATA_SIZE(root)) {
2695 if (slot >= nritems) {
2696 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2697 btrfs_set_header_nritems(right, 0);
2698 wret = insert_ptr(trans, root, path,
2699 &disk_key, right->start,
2700 path->slots[1] + 1, 1);
2704 btrfs_tree_unlock(path->nodes[0]);
2705 free_extent_buffer(path->nodes[0]);
2706 path->nodes[0] = right;
2708 path->slots[1] += 1;
2709 btrfs_mark_buffer_dirty(right);
2713 if (mid != nritems &&
2714 leaf_space_used(l, mid, nritems - mid) +
2715 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2720 if (leaf_space_used(l, 0, mid) + data_size >
2721 BTRFS_LEAF_DATA_SIZE(root)) {
2722 if (!extend && data_size && slot == 0) {
2723 btrfs_cpu_key_to_disk(&disk_key, ins_key);
2724 btrfs_set_header_nritems(right, 0);
2725 wret = insert_ptr(trans, root, path,
2731 btrfs_tree_unlock(path->nodes[0]);
2732 free_extent_buffer(path->nodes[0]);
2733 path->nodes[0] = right;
2735 if (path->slots[1] == 0) {
2736 wret = fixup_low_keys(trans, root,
2737 path, &disk_key, 1);
2741 btrfs_mark_buffer_dirty(right);
2743 } else if ((extend || !data_size) && slot == 0) {
2747 if (mid != nritems &&
2748 leaf_space_used(l, mid, nritems - mid) +
2749 data_size > BTRFS_LEAF_DATA_SIZE(root)) {
2755 nritems = nritems - mid;
2756 btrfs_set_header_nritems(right, nritems);
2757 data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l);
2759 copy_extent_buffer(right, l, btrfs_item_nr_offset(0),
2760 btrfs_item_nr_offset(mid),
2761 nritems * sizeof(struct btrfs_item));
2763 copy_extent_buffer(right, l,
2764 btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) -
2765 data_copy_size, btrfs_leaf_data(l) +
2766 leaf_data_end(root, l), data_copy_size);
2768 rt_data_off = BTRFS_LEAF_DATA_SIZE(root) -
2769 btrfs_item_end_nr(l, mid);
2771 for (i = 0; i < nritems; i++) {
2772 struct btrfs_item *item = btrfs_item_nr(right, i);
2775 if (!right->map_token) {
2776 map_extent_buffer(right, (unsigned long)item,
2777 sizeof(struct btrfs_item),
2778 &right->map_token, &right->kaddr,
2779 &right->map_start, &right->map_len,
2783 ioff = btrfs_item_offset(right, item);
2784 btrfs_set_item_offset(right, item, ioff + rt_data_off);
2787 if (right->map_token) {
2788 unmap_extent_buffer(right, right->map_token, KM_USER1);
2789 right->map_token = NULL;
2792 btrfs_set_header_nritems(l, mid);
2794 btrfs_item_key(right, &disk_key, 0);
2795 wret = insert_ptr(trans, root, path, &disk_key, right->start,
2796 path->slots[1] + 1, 1);
2800 btrfs_mark_buffer_dirty(right);
2801 btrfs_mark_buffer_dirty(l);
2802 BUG_ON(path->slots[0] != slot);
2804 ret = btrfs_update_ref(trans, root, l, right, 0, nritems);
2808 btrfs_tree_unlock(path->nodes[0]);
2809 free_extent_buffer(path->nodes[0]);
2810 path->nodes[0] = right;
2811 path->slots[0] -= mid;
2812 path->slots[1] += 1;
2814 btrfs_tree_unlock(right);
2815 free_extent_buffer(right);
2818 BUG_ON(path->slots[0] < 0);
2821 BUG_ON(num_doubles != 0);
2829 * This function splits a single item into two items,
2830 * giving 'new_key' to the new item and splitting the
2831 * old one at split_offset (from the start of the item).
2833 * The path may be released by this operation. After
2834 * the split, the path is pointing to the old item. The
2835 * new item is going to be in the same node as the old one.
2837 * Note, the item being split must be smaller enough to live alone on
2838 * a tree block with room for one extra struct btrfs_item
2840 * This allows us to split the item in place, keeping a lock on the
2841 * leaf the entire time.
2843 int btrfs_split_item(struct btrfs_trans_handle *trans,
2844 struct btrfs_root *root,
2845 struct btrfs_path *path,
2846 struct btrfs_key *new_key,
2847 unsigned long split_offset)
2850 struct extent_buffer *leaf;
2851 struct btrfs_key orig_key;
2852 struct btrfs_item *item;
2853 struct btrfs_item *new_item;
2858 struct btrfs_disk_key disk_key;
2861 leaf = path->nodes[0];
2862 btrfs_item_key_to_cpu(leaf, &orig_key, path->slots[0]);
2863 if (btrfs_leaf_free_space(root, leaf) >= sizeof(struct btrfs_item))
2866 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
2867 btrfs_release_path(root, path);
2869 path->search_for_split = 1;
2870 path->keep_locks = 1;
2872 ret = btrfs_search_slot(trans, root, &orig_key, path, 0, 1);
2873 path->search_for_split = 0;
2875 /* if our item isn't there or got smaller, return now */
2876 if (ret != 0 || item_size != btrfs_item_size_nr(path->nodes[0],
2878 path->keep_locks = 0;
2882 ret = split_leaf(trans, root, &orig_key, path,
2883 sizeof(struct btrfs_item), 1);
2884 path->keep_locks = 0;
2887 leaf = path->nodes[0];
2888 BUG_ON(btrfs_leaf_free_space(root, leaf) < sizeof(struct btrfs_item));
2891 item = btrfs_item_nr(leaf, path->slots[0]);
2892 orig_offset = btrfs_item_offset(leaf, item);
2893 item_size = btrfs_item_size(leaf, item);
2896 buf = kmalloc(item_size, GFP_NOFS);
2897 read_extent_buffer(leaf, buf, btrfs_item_ptr_offset(leaf,
2898 path->slots[0]), item_size);
2899 slot = path->slots[0] + 1;
2900 leaf = path->nodes[0];
2902 nritems = btrfs_header_nritems(leaf);
2904 if (slot != nritems) {
2905 /* shift the items */
2906 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + 1),
2907 btrfs_item_nr_offset(slot),
2908 (nritems - slot) * sizeof(struct btrfs_item));
2912 btrfs_cpu_key_to_disk(&disk_key, new_key);
2913 btrfs_set_item_key(leaf, &disk_key, slot);
2915 new_item = btrfs_item_nr(leaf, slot);
2917 btrfs_set_item_offset(leaf, new_item, orig_offset);
2918 btrfs_set_item_size(leaf, new_item, item_size - split_offset);
2920 btrfs_set_item_offset(leaf, item,
2921 orig_offset + item_size - split_offset);
2922 btrfs_set_item_size(leaf, item, split_offset);
2924 btrfs_set_header_nritems(leaf, nritems + 1);
2926 /* write the data for the start of the original item */
2927 write_extent_buffer(leaf, buf,
2928 btrfs_item_ptr_offset(leaf, path->slots[0]),
2931 /* write the data for the new item */
2932 write_extent_buffer(leaf, buf + split_offset,
2933 btrfs_item_ptr_offset(leaf, slot),
2934 item_size - split_offset);
2935 btrfs_mark_buffer_dirty(leaf);
2938 if (btrfs_leaf_free_space(root, leaf) < 0) {
2939 btrfs_print_leaf(root, leaf);
2947 * make the item pointed to by the path smaller. new_size indicates
2948 * how small to make it, and from_end tells us if we just chop bytes
2949 * off the end of the item or if we shift the item to chop bytes off
2952 int btrfs_truncate_item(struct btrfs_trans_handle *trans,
2953 struct btrfs_root *root,
2954 struct btrfs_path *path,
2955 u32 new_size, int from_end)
2960 struct extent_buffer *leaf;
2961 struct btrfs_item *item;
2963 unsigned int data_end;
2964 unsigned int old_data_start;
2965 unsigned int old_size;
2966 unsigned int size_diff;
2969 slot_orig = path->slots[0];
2970 leaf = path->nodes[0];
2971 slot = path->slots[0];
2973 old_size = btrfs_item_size_nr(leaf, slot);
2974 if (old_size == new_size)
2977 nritems = btrfs_header_nritems(leaf);
2978 data_end = leaf_data_end(root, leaf);
2980 old_data_start = btrfs_item_offset_nr(leaf, slot);
2982 size_diff = old_size - new_size;
2985 BUG_ON(slot >= nritems);
2988 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2990 /* first correct the data pointers */
2991 for (i = slot; i < nritems; i++) {
2993 item = btrfs_item_nr(leaf, i);
2995 if (!leaf->map_token) {
2996 map_extent_buffer(leaf, (unsigned long)item,
2997 sizeof(struct btrfs_item),
2998 &leaf->map_token, &leaf->kaddr,
2999 &leaf->map_start, &leaf->map_len,
3003 ioff = btrfs_item_offset(leaf, item);
3004 btrfs_set_item_offset(leaf, item, ioff + size_diff);
3007 if (leaf->map_token) {
3008 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3009 leaf->map_token = NULL;
3012 /* shift the data */
3014 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3015 data_end + size_diff, btrfs_leaf_data(leaf) +
3016 data_end, old_data_start + new_size - data_end);
3018 struct btrfs_disk_key disk_key;
3021 btrfs_item_key(leaf, &disk_key, slot);
3023 if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) {
3025 struct btrfs_file_extent_item *fi;
3027 fi = btrfs_item_ptr(leaf, slot,
3028 struct btrfs_file_extent_item);
3029 fi = (struct btrfs_file_extent_item *)(
3030 (unsigned long)fi - size_diff);
3032 if (btrfs_file_extent_type(leaf, fi) ==
3033 BTRFS_FILE_EXTENT_INLINE) {
3034 ptr = btrfs_item_ptr_offset(leaf, slot);
3035 memmove_extent_buffer(leaf, ptr,
3037 offsetof(struct btrfs_file_extent_item,
3042 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3043 data_end + size_diff, btrfs_leaf_data(leaf) +
3044 data_end, old_data_start - data_end);
3046 offset = btrfs_disk_key_offset(&disk_key);
3047 btrfs_set_disk_key_offset(&disk_key, offset + size_diff);
3048 btrfs_set_item_key(leaf, &disk_key, slot);
3050 fixup_low_keys(trans, root, path, &disk_key, 1);
3053 item = btrfs_item_nr(leaf, slot);
3054 btrfs_set_item_size(leaf, item, new_size);
3055 btrfs_mark_buffer_dirty(leaf);
3058 if (btrfs_leaf_free_space(root, leaf) < 0) {
3059 btrfs_print_leaf(root, leaf);
3066 * make the item pointed to by the path bigger, data_size is the new size.
3068 int btrfs_extend_item(struct btrfs_trans_handle *trans,
3069 struct btrfs_root *root, struct btrfs_path *path,
3075 struct extent_buffer *leaf;
3076 struct btrfs_item *item;
3078 unsigned int data_end;
3079 unsigned int old_data;
3080 unsigned int old_size;
3083 slot_orig = path->slots[0];
3084 leaf = path->nodes[0];
3086 nritems = btrfs_header_nritems(leaf);
3087 data_end = leaf_data_end(root, leaf);
3089 if (btrfs_leaf_free_space(root, leaf) < data_size) {
3090 btrfs_print_leaf(root, leaf);
3093 slot = path->slots[0];
3094 old_data = btrfs_item_end_nr(leaf, slot);
3097 if (slot >= nritems) {
3098 btrfs_print_leaf(root, leaf);
3099 printk("slot %d too large, nritems %d\n", slot, nritems);
3104 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3106 /* first correct the data pointers */
3107 for (i = slot; i < nritems; i++) {
3109 item = btrfs_item_nr(leaf, i);
3111 if (!leaf->map_token) {
3112 map_extent_buffer(leaf, (unsigned long)item,
3113 sizeof(struct btrfs_item),
3114 &leaf->map_token, &leaf->kaddr,
3115 &leaf->map_start, &leaf->map_len,
3118 ioff = btrfs_item_offset(leaf, item);
3119 btrfs_set_item_offset(leaf, item, ioff - data_size);
3122 if (leaf->map_token) {
3123 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3124 leaf->map_token = NULL;
3127 /* shift the data */
3128 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3129 data_end - data_size, btrfs_leaf_data(leaf) +
3130 data_end, old_data - data_end);
3132 data_end = old_data;
3133 old_size = btrfs_item_size_nr(leaf, slot);
3134 item = btrfs_item_nr(leaf, slot);
3135 btrfs_set_item_size(leaf, item, old_size + data_size);
3136 btrfs_mark_buffer_dirty(leaf);
3139 if (btrfs_leaf_free_space(root, leaf) < 0) {
3140 btrfs_print_leaf(root, leaf);
3147 * Given a key and some data, insert items into the tree.
3148 * This does all the path init required, making room in the tree if needed.
3149 * Returns the number of keys that were inserted.
3151 int btrfs_insert_some_items(struct btrfs_trans_handle *trans,
3152 struct btrfs_root *root,
3153 struct btrfs_path *path,
3154 struct btrfs_key *cpu_key, u32 *data_size,
3157 struct extent_buffer *leaf;
3158 struct btrfs_item *item;
3165 unsigned int data_end;
3166 struct btrfs_disk_key disk_key;
3167 struct btrfs_key found_key;
3169 for (i = 0; i < nr; i++) {
3170 if (total_size + data_size[i] + sizeof(struct btrfs_item) >
3171 BTRFS_LEAF_DATA_SIZE(root)) {
3175 total_data += data_size[i];
3176 total_size += data_size[i] + sizeof(struct btrfs_item);
3180 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3186 leaf = path->nodes[0];
3188 nritems = btrfs_header_nritems(leaf);
3189 data_end = leaf_data_end(root, leaf);
3191 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3192 for (i = nr; i >= 0; i--) {
3193 total_data -= data_size[i];
3194 total_size -= data_size[i] + sizeof(struct btrfs_item);
3195 if (total_size < btrfs_leaf_free_space(root, leaf))
3201 slot = path->slots[0];
3204 if (slot != nritems) {
3205 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3207 item = btrfs_item_nr(leaf, slot);
3208 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3210 /* figure out how many keys we can insert in here */
3211 total_data = data_size[0];
3212 for (i = 1; i < nr; i++) {
3213 if (comp_cpu_keys(&found_key, cpu_key + i) <= 0)
3215 total_data += data_size[i];
3219 if (old_data < data_end) {
3220 btrfs_print_leaf(root, leaf);
3221 printk("slot %d old_data %d data_end %d\n",
3222 slot, old_data, data_end);
3226 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3228 /* first correct the data pointers */
3229 WARN_ON(leaf->map_token);
3230 for (i = slot; i < nritems; i++) {
3233 item = btrfs_item_nr(leaf, i);
3234 if (!leaf->map_token) {
3235 map_extent_buffer(leaf, (unsigned long)item,
3236 sizeof(struct btrfs_item),
3237 &leaf->map_token, &leaf->kaddr,
3238 &leaf->map_start, &leaf->map_len,
3242 ioff = btrfs_item_offset(leaf, item);
3243 btrfs_set_item_offset(leaf, item, ioff - total_data);
3245 if (leaf->map_token) {
3246 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3247 leaf->map_token = NULL;
3250 /* shift the items */
3251 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3252 btrfs_item_nr_offset(slot),
3253 (nritems - slot) * sizeof(struct btrfs_item));
3255 /* shift the data */
3256 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3257 data_end - total_data, btrfs_leaf_data(leaf) +
3258 data_end, old_data - data_end);
3259 data_end = old_data;
3262 * this sucks but it has to be done, if we are inserting at
3263 * the end of the leaf only insert 1 of the items, since we
3264 * have no way of knowing whats on the next leaf and we'd have
3265 * to drop our current locks to figure it out
3270 /* setup the item for the new data */
3271 for (i = 0; i < nr; i++) {
3272 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3273 btrfs_set_item_key(leaf, &disk_key, slot + i);
3274 item = btrfs_item_nr(leaf, slot + i);
3275 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3276 data_end -= data_size[i];
3277 btrfs_set_item_size(leaf, item, data_size[i]);
3279 btrfs_set_header_nritems(leaf, nritems + nr);
3280 btrfs_mark_buffer_dirty(leaf);
3284 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3285 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3288 if (btrfs_leaf_free_space(root, leaf) < 0) {
3289 btrfs_print_leaf(root, leaf);
3299 * Given a key and some data, insert items into the tree.
3300 * This does all the path init required, making room in the tree if needed.
3302 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
3303 struct btrfs_root *root,
3304 struct btrfs_path *path,
3305 struct btrfs_key *cpu_key, u32 *data_size,
3308 struct extent_buffer *leaf;
3309 struct btrfs_item *item;
3317 unsigned int data_end;
3318 struct btrfs_disk_key disk_key;
3320 for (i = 0; i < nr; i++) {
3321 total_data += data_size[i];
3324 total_size = total_data + (nr * sizeof(struct btrfs_item));
3325 ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1);
3331 slot_orig = path->slots[0];
3332 leaf = path->nodes[0];
3334 nritems = btrfs_header_nritems(leaf);
3335 data_end = leaf_data_end(root, leaf);
3337 if (btrfs_leaf_free_space(root, leaf) < total_size) {
3338 btrfs_print_leaf(root, leaf);
3339 printk("not enough freespace need %u have %d\n",
3340 total_size, btrfs_leaf_free_space(root, leaf));
3344 slot = path->slots[0];
3347 if (slot != nritems) {
3348 unsigned int old_data = btrfs_item_end_nr(leaf, slot);
3350 if (old_data < data_end) {
3351 btrfs_print_leaf(root, leaf);
3352 printk("slot %d old_data %d data_end %d\n",
3353 slot, old_data, data_end);
3357 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3359 /* first correct the data pointers */
3360 WARN_ON(leaf->map_token);
3361 for (i = slot; i < nritems; i++) {
3364 item = btrfs_item_nr(leaf, i);
3365 if (!leaf->map_token) {
3366 map_extent_buffer(leaf, (unsigned long)item,
3367 sizeof(struct btrfs_item),
3368 &leaf->map_token, &leaf->kaddr,
3369 &leaf->map_start, &leaf->map_len,
3373 ioff = btrfs_item_offset(leaf, item);
3374 btrfs_set_item_offset(leaf, item, ioff - total_data);
3376 if (leaf->map_token) {
3377 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3378 leaf->map_token = NULL;
3381 /* shift the items */
3382 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr),
3383 btrfs_item_nr_offset(slot),
3384 (nritems - slot) * sizeof(struct btrfs_item));
3386 /* shift the data */
3387 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3388 data_end - total_data, btrfs_leaf_data(leaf) +
3389 data_end, old_data - data_end);
3390 data_end = old_data;
3393 /* setup the item for the new data */
3394 for (i = 0; i < nr; i++) {
3395 btrfs_cpu_key_to_disk(&disk_key, cpu_key + i);
3396 btrfs_set_item_key(leaf, &disk_key, slot + i);
3397 item = btrfs_item_nr(leaf, slot + i);
3398 btrfs_set_item_offset(leaf, item, data_end - data_size[i]);
3399 data_end -= data_size[i];
3400 btrfs_set_item_size(leaf, item, data_size[i]);
3402 btrfs_set_header_nritems(leaf, nritems + nr);
3403 btrfs_mark_buffer_dirty(leaf);
3407 btrfs_cpu_key_to_disk(&disk_key, cpu_key);
3408 ret = fixup_low_keys(trans, root, path, &disk_key, 1);
3411 if (btrfs_leaf_free_space(root, leaf) < 0) {
3412 btrfs_print_leaf(root, leaf);
3420 * Given a key and some data, insert an item into the tree.
3421 * This does all the path init required, making room in the tree if needed.
3423 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
3424 *root, struct btrfs_key *cpu_key, void *data, u32
3428 struct btrfs_path *path;
3429 struct extent_buffer *leaf;
3432 path = btrfs_alloc_path();
3434 ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
3436 leaf = path->nodes[0];
3437 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3438 write_extent_buffer(leaf, data, ptr, data_size);
3439 btrfs_mark_buffer_dirty(leaf);
3441 btrfs_free_path(path);
3446 * delete the pointer from a given node.
3448 * the tree should have been previously balanced so the deletion does not
3451 static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3452 struct btrfs_path *path, int level, int slot)
3454 struct extent_buffer *parent = path->nodes[level];
3459 nritems = btrfs_header_nritems(parent);
3460 if (slot != nritems -1) {
3461 memmove_extent_buffer(parent,
3462 btrfs_node_key_ptr_offset(slot),
3463 btrfs_node_key_ptr_offset(slot + 1),
3464 sizeof(struct btrfs_key_ptr) *
3465 (nritems - slot - 1));
3468 btrfs_set_header_nritems(parent, nritems);
3469 if (nritems == 0 && parent == root->node) {
3470 BUG_ON(btrfs_header_level(root->node) != 1);
3471 /* just turn the root into a leaf and break */
3472 btrfs_set_header_level(root->node, 0);
3473 } else if (slot == 0) {
3474 struct btrfs_disk_key disk_key;
3476 btrfs_node_key(parent, &disk_key, 0);
3477 wret = fixup_low_keys(trans, root, path, &disk_key, level + 1);
3481 btrfs_mark_buffer_dirty(parent);
3486 * a helper function to delete the leaf pointed to by path->slots[1] and
3487 * path->nodes[1]. bytenr is the node block pointer, but since the callers
3488 * already know it, it is faster to have them pass it down than to
3489 * read it out of the node again.
3491 * This deletes the pointer in path->nodes[1] and frees the leaf
3492 * block extent. zero is returned if it all worked out, < 0 otherwise.
3494 * The path must have already been setup for deleting the leaf, including
3495 * all the proper balancing. path->nodes[1] must be locked.
3497 noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
3498 struct btrfs_root *root,
3499 struct btrfs_path *path, u64 bytenr)
3502 u64 root_gen = btrfs_header_generation(path->nodes[1]);
3504 ret = del_ptr(trans, root, path, 1, path->slots[1]);
3508 ret = btrfs_free_extent(trans, root, bytenr,
3509 btrfs_level_size(root, 0),
3510 path->nodes[1]->start,
3511 btrfs_header_owner(path->nodes[1]),
3516 * delete the item at the leaf level in path. If that empties
3517 * the leaf, remove it from the tree
3519 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
3520 struct btrfs_path *path, int slot, int nr)
3522 struct extent_buffer *leaf;
3523 struct btrfs_item *item;
3531 leaf = path->nodes[0];
3532 last_off = btrfs_item_offset_nr(leaf, slot + nr - 1);
3534 for (i = 0; i < nr; i++)
3535 dsize += btrfs_item_size_nr(leaf, slot + i);
3537 nritems = btrfs_header_nritems(leaf);
3539 if (slot + nr != nritems) {
3540 int data_end = leaf_data_end(root, leaf);
3542 memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) +
3544 btrfs_leaf_data(leaf) + data_end,
3545 last_off - data_end);
3547 for (i = slot + nr; i < nritems; i++) {
3550 item = btrfs_item_nr(leaf, i);
3551 if (!leaf->map_token) {
3552 map_extent_buffer(leaf, (unsigned long)item,
3553 sizeof(struct btrfs_item),
3554 &leaf->map_token, &leaf->kaddr,
3555 &leaf->map_start, &leaf->map_len,
3558 ioff = btrfs_item_offset(leaf, item);
3559 btrfs_set_item_offset(leaf, item, ioff + dsize);
3562 if (leaf->map_token) {
3563 unmap_extent_buffer(leaf, leaf->map_token, KM_USER1);
3564 leaf->map_token = NULL;
3567 memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot),
3568 btrfs_item_nr_offset(slot + nr),
3569 sizeof(struct btrfs_item) *
3570 (nritems - slot - nr));
3572 btrfs_set_header_nritems(leaf, nritems - nr);
3575 /* delete the leaf if we've emptied it */
3577 if (leaf == root->node) {
3578 btrfs_set_header_level(leaf, 0);
3580 ret = btrfs_del_leaf(trans, root, path, leaf->start);
3584 int used = leaf_space_used(leaf, 0, nritems);
3586 struct btrfs_disk_key disk_key;
3588 btrfs_item_key(leaf, &disk_key, 0);
3589 wret = fixup_low_keys(trans, root, path,
3595 /* delete the leaf if it is mostly empty */
3596 if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) {
3597 /* push_leaf_left fixes the path.
3598 * make sure the path still points to our leaf
3599 * for possible call to del_ptr below
3601 slot = path->slots[1];
3602 extent_buffer_get(leaf);
3604 wret = push_leaf_left(trans, root, path, 1, 1);
3605 if (wret < 0 && wret != -ENOSPC)
3608 if (path->nodes[0] == leaf &&
3609 btrfs_header_nritems(leaf)) {
3610 wret = push_leaf_right(trans, root, path, 1, 1);
3611 if (wret < 0 && wret != -ENOSPC)
3615 if (btrfs_header_nritems(leaf) == 0) {
3616 path->slots[1] = slot;
3617 ret = btrfs_del_leaf(trans, root, path, leaf->start);
3619 free_extent_buffer(leaf);
3621 /* if we're still in the path, make sure
3622 * we're dirty. Otherwise, one of the
3623 * push_leaf functions must have already
3624 * dirtied this buffer
3626 if (path->nodes[0] == leaf)
3627 btrfs_mark_buffer_dirty(leaf);
3628 free_extent_buffer(leaf);
3631 btrfs_mark_buffer_dirty(leaf);
3638 * search the tree again to find a leaf with lesser keys
3639 * returns 0 if it found something or 1 if there are no lesser leaves.
3640 * returns < 0 on io errors.
3642 * This may release the path, and so you may lose any locks held at the
3645 int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path)
3647 struct btrfs_key key;
3648 struct btrfs_disk_key found_key;
3651 btrfs_item_key_to_cpu(path->nodes[0], &key, 0);
3655 else if (key.type > 0)
3657 else if (key.objectid > 0)
3662 btrfs_release_path(root, path);
3663 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3666 btrfs_item_key(path->nodes[0], &found_key, 0);
3667 ret = comp_keys(&found_key, &key);
3674 * A helper function to walk down the tree starting at min_key, and looking
3675 * for nodes or leaves that are either in cache or have a minimum
3676 * transaction id. This is used by the btree defrag code, and tree logging
3678 * This does not cow, but it does stuff the starting key it finds back
3679 * into min_key, so you can call btrfs_search_slot with cow=1 on the
3680 * key and get a writable path.
3682 * This does lock as it descends, and path->keep_locks should be set
3683 * to 1 by the caller.
3685 * This honors path->lowest_level to prevent descent past a given level
3688 * min_trans indicates the oldest transaction that you are interested
3689 * in walking through. Any nodes or leaves older than min_trans are
3690 * skipped over (without reading them).
3692 * returns zero if something useful was found, < 0 on error and 1 if there
3693 * was nothing in the tree that matched the search criteria.
3695 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
3696 struct btrfs_key *max_key,
3697 struct btrfs_path *path, int cache_only,
3700 struct extent_buffer *cur;
3701 struct btrfs_key found_key;
3708 WARN_ON(!path->keep_locks);
3710 cur = btrfs_lock_root_node(root);
3711 level = btrfs_header_level(cur);
3712 WARN_ON(path->nodes[level]);
3713 path->nodes[level] = cur;
3714 path->locks[level] = 1;
3716 if (btrfs_header_generation(cur) < min_trans) {
3721 nritems = btrfs_header_nritems(cur);
3722 level = btrfs_header_level(cur);
3723 sret = bin_search(cur, min_key, level, &slot);
3725 /* at the lowest level, we're done, setup the path and exit */
3726 if (level == path->lowest_level) {
3727 if (slot >= nritems)
3730 path->slots[level] = slot;
3731 btrfs_item_key_to_cpu(cur, &found_key, slot);
3734 if (sret && slot > 0)
3737 * check this node pointer against the cache_only and
3738 * min_trans parameters. If it isn't in cache or is too
3739 * old, skip to the next one.
3741 while(slot < nritems) {
3744 struct extent_buffer *tmp;
3745 struct btrfs_disk_key disk_key;
3747 blockptr = btrfs_node_blockptr(cur, slot);
3748 gen = btrfs_node_ptr_generation(cur, slot);
3749 if (gen < min_trans) {
3757 btrfs_node_key(cur, &disk_key, slot);
3758 if (comp_keys(&disk_key, max_key) >= 0) {
3764 tmp = btrfs_find_tree_block(root, blockptr,
3765 btrfs_level_size(root, level - 1));
3767 if (tmp && btrfs_buffer_uptodate(tmp, gen)) {
3768 free_extent_buffer(tmp);
3772 free_extent_buffer(tmp);
3777 * we didn't find a candidate key in this node, walk forward
3778 * and find another one
3780 if (slot >= nritems) {
3781 path->slots[level] = slot;
3782 sret = btrfs_find_next_key(root, path, min_key, level,
3783 cache_only, min_trans);
3785 btrfs_release_path(root, path);
3791 /* save our key for returning back */
3792 btrfs_node_key_to_cpu(cur, &found_key, slot);
3793 path->slots[level] = slot;
3794 if (level == path->lowest_level) {
3796 unlock_up(path, level, 1);
3799 cur = read_node_slot(root, cur, slot);
3801 btrfs_tree_lock(cur);
3802 path->locks[level - 1] = 1;
3803 path->nodes[level - 1] = cur;
3804 unlock_up(path, level, 1);
3808 memcpy(min_key, &found_key, sizeof(found_key));
3813 * this is similar to btrfs_next_leaf, but does not try to preserve
3814 * and fixup the path. It looks for and returns the next key in the
3815 * tree based on the current path and the cache_only and min_trans
3818 * 0 is returned if another key is found, < 0 if there are any errors
3819 * and 1 is returned if there are no higher keys in the tree
3821 * path->keep_locks should be set to 1 on the search made before
3822 * calling this function.
3824 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
3825 struct btrfs_key *key, int lowest_level,
3826 int cache_only, u64 min_trans)
3828 int level = lowest_level;
3830 struct extent_buffer *c;
3832 WARN_ON(!path->keep_locks);
3833 while(level < BTRFS_MAX_LEVEL) {
3834 if (!path->nodes[level])
3837 slot = path->slots[level] + 1;
3838 c = path->nodes[level];
3840 if (slot >= btrfs_header_nritems(c)) {
3842 if (level == BTRFS_MAX_LEVEL) {
3848 btrfs_item_key_to_cpu(c, key, slot);
3850 u64 blockptr = btrfs_node_blockptr(c, slot);
3851 u64 gen = btrfs_node_ptr_generation(c, slot);
3854 struct extent_buffer *cur;
3855 cur = btrfs_find_tree_block(root, blockptr,
3856 btrfs_level_size(root, level - 1));
3857 if (!cur || !btrfs_buffer_uptodate(cur, gen)) {
3860 free_extent_buffer(cur);
3863 free_extent_buffer(cur);
3865 if (gen < min_trans) {
3869 btrfs_node_key_to_cpu(c, key, slot);
3877 * search the tree again to find a leaf with greater keys
3878 * returns 0 if it found something or 1 if there are no greater leaves.
3879 * returns < 0 on io errors.
3881 int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
3885 struct extent_buffer *c;
3886 struct extent_buffer *next = NULL;
3887 struct btrfs_key key;
3891 nritems = btrfs_header_nritems(path->nodes[0]);
3896 btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1);
3898 btrfs_release_path(root, path);
3899 path->keep_locks = 1;
3900 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3901 path->keep_locks = 0;
3906 nritems = btrfs_header_nritems(path->nodes[0]);
3908 * by releasing the path above we dropped all our locks. A balance
3909 * could have added more items next to the key that used to be
3910 * at the very end of the block. So, check again here and
3911 * advance the path if there are now more items available.
3913 if (nritems > 0 && path->slots[0] < nritems - 1) {
3918 while(level < BTRFS_MAX_LEVEL) {
3919 if (!path->nodes[level])
3922 slot = path->slots[level] + 1;
3923 c = path->nodes[level];
3924 if (slot >= btrfs_header_nritems(c)) {
3926 if (level == BTRFS_MAX_LEVEL) {
3933 btrfs_tree_unlock(next);
3934 free_extent_buffer(next);
3937 if (level == 1 && (path->locks[1] || path->skip_locking) &&
3939 reada_for_search(root, path, level, slot, 0);
3941 next = read_node_slot(root, c, slot);
3942 if (!path->skip_locking) {
3943 WARN_ON(!btrfs_tree_locked(c));
3944 btrfs_tree_lock(next);
3948 path->slots[level] = slot;
3951 c = path->nodes[level];
3952 if (path->locks[level])
3953 btrfs_tree_unlock(c);
3954 free_extent_buffer(c);
3955 path->nodes[level] = next;
3956 path->slots[level] = 0;
3957 if (!path->skip_locking)
3958 path->locks[level] = 1;
3961 if (level == 1 && path->locks[1] && path->reada)
3962 reada_for_search(root, path, level, slot, 0);
3963 next = read_node_slot(root, next, 0);
3964 if (!path->skip_locking) {
3965 WARN_ON(!btrfs_tree_locked(path->nodes[level]));
3966 btrfs_tree_lock(next);
3970 unlock_up(path, 0, 1);
3975 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
3976 * searching until it gets past min_objectid or finds an item of 'type'
3978 * returns 0 if something is found, 1 if nothing was found and < 0 on error
3980 int btrfs_previous_item(struct btrfs_root *root,
3981 struct btrfs_path *path, u64 min_objectid,
3984 struct btrfs_key found_key;
3985 struct extent_buffer *leaf;
3990 if (path->slots[0] == 0) {
3991 ret = btrfs_prev_leaf(root, path);
3997 leaf = path->nodes[0];
3998 nritems = btrfs_header_nritems(leaf);
4001 if (path->slots[0] == nritems)
4004 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4005 if (found_key.type == type)
4007 if (found_key.objectid < min_objectid)
4009 if (found_key.objectid == min_objectid &&
4010 found_key.type < type)