2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
21 #include "kerncompat.h"
22 #include "radix-tree.h"
25 #include "print-tree.h"
27 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
28 *root
, struct btrfs_path
*path
, int level
);
29 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
30 *root
, struct btrfs_path
*path
, int data_size
);
31 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
32 *root
, struct btrfs_buffer
*dst
, struct btrfs_buffer
34 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
35 btrfs_root
*root
, struct btrfs_buffer
*dst_buf
,
36 struct btrfs_buffer
*src_buf
);
37 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
38 struct btrfs_path
*path
, int level
, int slot
);
40 inline void btrfs_init_path(struct btrfs_path
*p
)
42 memset(p
, 0, sizeof(*p
));
45 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
48 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
51 btrfs_block_release(root
, p
->nodes
[i
]);
53 memset(p
, 0, sizeof(*p
));
56 static int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
57 *root
, struct btrfs_buffer
*buf
, struct btrfs_buffer
58 *parent
, int parent_slot
, struct btrfs_buffer
61 struct btrfs_buffer
*cow
;
63 if (!list_empty(&buf
->dirty
)) {
67 cow
= btrfs_alloc_free_block(trans
, root
);
68 memcpy(&cow
->node
, &buf
->node
, root
->blocksize
);
69 btrfs_set_header_blocknr(&cow
->node
.header
, cow
->blocknr
);
70 btrfs_set_header_owner(&cow
->node
.header
, root
->root_key
.objectid
);
72 btrfs_inc_ref(trans
, root
, buf
);
73 if (buf
== root
->node
) {
76 if (buf
!= root
->commit_root
)
77 btrfs_free_extent(trans
, root
, buf
->blocknr
, 1, 1);
78 btrfs_block_release(root
, buf
);
80 btrfs_set_node_blockptr(&parent
->node
, parent_slot
,
82 BUG_ON(list_empty(&parent
->dirty
));
83 btrfs_free_extent(trans
, root
, buf
->blocknr
, 1, 1);
85 btrfs_block_release(root
, buf
);
90 * The leaf data grows from end-to-front in the node.
91 * this returns the address of the start of the last item,
92 * which is the stop of the leaf data stack
94 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
95 struct btrfs_leaf
*leaf
)
97 u32 nr
= btrfs_header_nritems(&leaf
->header
);
99 return BTRFS_LEAF_DATA_SIZE(root
);
100 return btrfs_item_offset(leaf
->items
+ nr
- 1);
104 * how many bytes are required to store the items in a leaf. start
105 * and nr indicate which items in the leaf to check. This totals up the
106 * space used both by the item structs and the item data
108 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
111 int nritems
= btrfs_header_nritems(&l
->header
);
114 if (nritems
< start
+ nr
)
117 end
= start
+ nr
- 1;
121 data_len
= btrfs_item_end(l
->items
+ start
);
122 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
123 data_len
+= sizeof(struct btrfs_item
) * nr
;
128 * The space between the end of the leaf items and
129 * the start of the leaf data. IOW, how much room
130 * the leaf has left for both items and data
132 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
134 int nritems
= btrfs_header_nritems(&leaf
->header
);
135 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
139 * compare two keys in a memcmp fashion
141 int btrfs_comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
145 btrfs_disk_key_to_cpu(&k1
, disk
);
147 if (k1
.objectid
> k2
->objectid
)
149 if (k1
.objectid
< k2
->objectid
)
151 if (k1
.flags
> k2
->flags
)
153 if (k1
.flags
< k2
->flags
)
155 if (k1
.offset
> k2
->offset
)
157 if (k1
.offset
< k2
->offset
)
162 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
166 struct btrfs_node
*parent
= NULL
;
167 struct btrfs_node
*node
= &path
->nodes
[level
]->node
;
169 u32 nritems
= btrfs_header_nritems(&node
->header
);
171 if (path
->nodes
[level
+ 1])
172 parent
= &path
->nodes
[level
+ 1]->node
;
173 parent_slot
= path
->slots
[level
+ 1];
174 BUG_ON(nritems
== 0);
176 struct btrfs_disk_key
*parent_key
;
177 parent_key
= &parent
->ptrs
[parent_slot
].key
;
178 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
179 sizeof(struct btrfs_disk_key
)));
180 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
181 btrfs_header_blocknr(&node
->header
));
183 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
184 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
185 struct btrfs_key cpukey
;
186 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[i
+ 1].key
);
187 BUG_ON(btrfs_comp_keys(&node
->ptrs
[i
].key
, &cpukey
) >= 0);
192 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
196 struct btrfs_leaf
*leaf
= &path
->nodes
[level
]->leaf
;
197 struct btrfs_node
*parent
= NULL
;
199 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
201 if (path
->nodes
[level
+ 1])
202 parent
= &path
->nodes
[level
+ 1]->node
;
203 parent_slot
= path
->slots
[level
+ 1];
204 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
210 struct btrfs_disk_key
*parent_key
;
211 parent_key
= &parent
->ptrs
[parent_slot
].key
;
212 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
213 sizeof(struct btrfs_disk_key
)));
214 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
215 btrfs_header_blocknr(&leaf
->header
));
217 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
218 struct btrfs_key cpukey
;
219 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[i
+ 1].key
);
220 BUG_ON(btrfs_comp_keys(&leaf
->items
[i
].key
,
222 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) !=
223 btrfs_item_end(leaf
->items
+ i
+ 1));
225 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) +
226 btrfs_item_size(leaf
->items
+ i
) !=
227 BTRFS_LEAF_DATA_SIZE(root
));
233 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
237 return check_leaf(root
, path
, level
);
238 return check_node(root
, path
, level
);
242 * search for key in the array p. items p are item_size apart
243 * and there are 'max' items in p
244 * the slot in the array is returned via slot, and it points to
245 * the place where you would insert key if it is not found in
248 * slot may point to max if the key is bigger than all of the keys
250 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
257 struct btrfs_disk_key
*tmp
;
260 mid
= (low
+ high
) / 2;
261 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
262 ret
= btrfs_comp_keys(tmp
, key
);
278 * simple bin_search frontend that does the right thing for
281 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
283 if (btrfs_is_leaf(c
)) {
284 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
285 return generic_bin_search((void *)l
->items
,
286 sizeof(struct btrfs_item
),
287 key
, btrfs_header_nritems(&c
->header
),
290 return generic_bin_search((void *)c
->ptrs
,
291 sizeof(struct btrfs_key_ptr
),
292 key
, btrfs_header_nritems(&c
->header
),
298 static struct btrfs_buffer
*read_node_slot(struct btrfs_root
*root
,
299 struct btrfs_buffer
*parent_buf
,
302 struct btrfs_node
*node
= &parent_buf
->node
;
305 if (slot
>= btrfs_header_nritems(&node
->header
))
307 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
310 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
311 *root
, struct btrfs_path
*path
, int level
)
313 struct btrfs_buffer
*right_buf
;
314 struct btrfs_buffer
*mid_buf
;
315 struct btrfs_buffer
*left_buf
;
316 struct btrfs_buffer
*parent_buf
= NULL
;
317 struct btrfs_node
*right
= NULL
;
318 struct btrfs_node
*mid
;
319 struct btrfs_node
*left
= NULL
;
320 struct btrfs_node
*parent
= NULL
;
324 int orig_slot
= path
->slots
[level
];
330 mid_buf
= path
->nodes
[level
];
331 mid
= &mid_buf
->node
;
332 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
334 if (level
< BTRFS_MAX_LEVEL
- 1)
335 parent_buf
= path
->nodes
[level
+ 1];
336 pslot
= path
->slots
[level
+ 1];
339 * deal with the case where there is only one pointer in the root
340 * by promoting the node below to a root
343 struct btrfs_buffer
*child
;
344 u64 blocknr
= mid_buf
->blocknr
;
346 if (btrfs_header_nritems(&mid
->header
) != 1)
349 /* promote the child to a root */
350 child
= read_node_slot(root
, mid_buf
, 0);
353 path
->nodes
[level
] = NULL
;
354 /* once for the path */
355 btrfs_block_release(root
, mid_buf
);
356 /* once for the root ptr */
357 btrfs_block_release(root
, mid_buf
);
358 clean_tree_block(trans
, root
, mid_buf
);
359 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
361 parent
= &parent_buf
->node
;
363 if (btrfs_header_nritems(&mid
->header
) >
364 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
367 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
368 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
370 /* first, try to make some room in the middle buffer */
372 btrfs_cow_block(trans
, root
, left_buf
, parent_buf
, pslot
- 1,
374 left
= &left_buf
->node
;
375 orig_slot
+= btrfs_header_nritems(&left
->header
);
376 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
382 * then try to empty the right most buffer into the middle
385 btrfs_cow_block(trans
, root
, right_buf
, parent_buf
, pslot
+ 1,
387 right
= &right_buf
->node
;
388 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
391 if (btrfs_header_nritems(&right
->header
) == 0) {
392 u64 blocknr
= right_buf
->blocknr
;
393 btrfs_block_release(root
, right_buf
);
394 clean_tree_block(trans
, root
, right_buf
);
397 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
401 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
405 memcpy(&parent
->ptrs
[pslot
+ 1].key
,
407 sizeof(struct btrfs_disk_key
));
408 BUG_ON(list_empty(&parent_buf
->dirty
));
411 if (btrfs_header_nritems(&mid
->header
) == 1) {
413 * we're not allowed to leave a node with one item in the
414 * tree during a delete. A deletion from lower in the tree
415 * could try to delete the only pointer in this node.
416 * So, pull some keys from the left.
417 * There has to be a left pointer at this point because
418 * otherwise we would have pulled some pointers from the
422 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
427 if (btrfs_header_nritems(&mid
->header
) == 0) {
428 /* we've managed to empty the middle node, drop it */
429 u64 blocknr
= mid_buf
->blocknr
;
430 btrfs_block_release(root
, mid_buf
);
431 clean_tree_block(trans
, root
, mid_buf
);
434 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
437 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
441 /* update the parent key to reflect our changes */
442 memcpy(&parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
443 sizeof(struct btrfs_disk_key
));
444 BUG_ON(list_empty(&parent_buf
->dirty
));
447 /* update the path */
449 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
450 left_buf
->count
++; // released below
451 path
->nodes
[level
] = left_buf
;
452 path
->slots
[level
+ 1] -= 1;
453 path
->slots
[level
] = orig_slot
;
455 btrfs_block_release(root
, mid_buf
);
457 orig_slot
-= btrfs_header_nritems(&left
->header
);
458 path
->slots
[level
] = orig_slot
;
461 /* double check we haven't messed things up */
462 check_block(root
, path
, level
);
463 if (orig_ptr
!= btrfs_node_blockptr(&path
->nodes
[level
]->node
,
468 btrfs_block_release(root
, right_buf
);
470 btrfs_block_release(root
, left_buf
);
475 * look for key in the tree. path is filled in with nodes along the way
476 * if key is found, we return zero and you can find the item in the leaf
477 * level of the path (level 0)
479 * If the key isn't found, the path points to the slot where it should
480 * be inserted, and 1 is returned. If there are other errors during the
481 * search a negative error number is returned.
483 * if ins_len > 0, nodes and leaves will be split as we walk down the
484 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
487 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
488 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
491 struct btrfs_buffer
*b
;
492 struct btrfs_buffer
*cow_buf
;
493 struct btrfs_node
*c
;
502 level
= btrfs_header_level(&b
->node
.header
);
505 wret
= btrfs_cow_block(trans
, root
, b
, p
->nodes
[level
+
506 1], p
->slots
[level
+ 1],
510 BUG_ON(!cow
&& ins_len
);
513 ret
= check_block(root
, p
, level
);
516 ret
= bin_search(c
, key
, &slot
);
517 if (!btrfs_is_leaf(c
)) {
520 p
->slots
[level
] = slot
;
521 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) ==
522 BTRFS_NODEPTRS_PER_BLOCK(root
)) {
523 int sret
= split_node(trans
, root
, p
, level
);
529 slot
= p
->slots
[level
];
530 } else if (ins_len
< 0) {
531 int sret
= balance_level(trans
, root
, p
,
539 slot
= p
->slots
[level
];
540 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
542 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
544 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
545 p
->slots
[level
] = slot
;
546 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
547 sizeof(struct btrfs_item
) + ins_len
) {
548 int sret
= split_leaf(trans
, root
, p
, ins_len
);
553 BUG_ON(root
->node
->count
== 1);
557 BUG_ON(root
->node
->count
== 1);
562 * adjust the pointers going up the tree, starting at level
563 * making sure the right key of each node is points to 'key'.
564 * This is used after shifting pointers to the left, so it stops
565 * fixing up pointers when a given leaf/node is not in slot 0 of the
568 * If this fails to write a tree block, it returns -1, but continues
569 * fixing up the blocks in ram so the tree is consistent.
571 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
572 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
577 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
578 struct btrfs_node
*t
;
579 int tslot
= path
->slots
[i
];
582 t
= &path
->nodes
[i
]->node
;
583 memcpy(&t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
584 BUG_ON(list_empty(&path
->nodes
[i
]->dirty
));
592 * try to push data from one node into the next node left in the
595 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
596 * error, and > 0 if there was no room in the left hand block.
598 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
599 *root
, struct btrfs_buffer
*dst_buf
, struct
600 btrfs_buffer
*src_buf
)
602 struct btrfs_node
*src
= &src_buf
->node
;
603 struct btrfs_node
*dst
= &dst_buf
->node
;
609 src_nritems
= btrfs_header_nritems(&src
->header
);
610 dst_nritems
= btrfs_header_nritems(&dst
->header
);
611 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
612 if (push_items
<= 0) {
616 if (src_nritems
< push_items
)
617 push_items
= src_nritems
;
619 memcpy(dst
->ptrs
+ dst_nritems
, src
->ptrs
,
620 push_items
* sizeof(struct btrfs_key_ptr
));
621 if (push_items
< src_nritems
) {
622 memmove(src
->ptrs
, src
->ptrs
+ push_items
,
623 (src_nritems
- push_items
) *
624 sizeof(struct btrfs_key_ptr
));
626 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
627 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
628 BUG_ON(list_empty(&src_buf
->dirty
));
629 BUG_ON(list_empty(&dst_buf
->dirty
));
634 * try to push data from one node into the next node right in the
637 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
638 * error, and > 0 if there was no room in the right hand block.
640 * this will only push up to 1/2 the contents of the left node over
642 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
643 btrfs_root
*root
, struct btrfs_buffer
*dst_buf
,
644 struct btrfs_buffer
*src_buf
)
646 struct btrfs_node
*src
= &src_buf
->node
;
647 struct btrfs_node
*dst
= &dst_buf
->node
;
654 src_nritems
= btrfs_header_nritems(&src
->header
);
655 dst_nritems
= btrfs_header_nritems(&dst
->header
);
656 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
657 if (push_items
<= 0) {
661 max_push
= src_nritems
/ 2 + 1;
662 /* don't try to empty the node */
663 if (max_push
> src_nritems
)
665 if (max_push
< push_items
)
666 push_items
= max_push
;
668 memmove(dst
->ptrs
+ push_items
, dst
->ptrs
,
669 dst_nritems
* sizeof(struct btrfs_key_ptr
));
670 memcpy(dst
->ptrs
, src
->ptrs
+ src_nritems
- push_items
,
671 push_items
* sizeof(struct btrfs_key_ptr
));
673 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
674 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
676 BUG_ON(list_empty(&src_buf
->dirty
));
677 BUG_ON(list_empty(&dst_buf
->dirty
));
682 * helper function to insert a new root level in the tree.
683 * A new node is allocated, and a single item is inserted to
684 * point to the existing root
686 * returns zero on success or < 0 on failure.
688 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
689 *root
, struct btrfs_path
*path
, int level
)
691 struct btrfs_buffer
*t
;
692 struct btrfs_node
*lower
;
693 struct btrfs_node
*c
;
694 struct btrfs_disk_key
*lower_key
;
696 BUG_ON(path
->nodes
[level
]);
697 BUG_ON(path
->nodes
[level
-1] != root
->node
);
699 t
= btrfs_alloc_free_block(trans
, root
);
701 memset(c
, 0, root
->blocksize
);
702 btrfs_set_header_nritems(&c
->header
, 1);
703 btrfs_set_header_level(&c
->header
, level
);
704 btrfs_set_header_blocknr(&c
->header
, t
->blocknr
);
705 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
706 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
707 sizeof(c
->header
.fsid
));
708 lower
= &path
->nodes
[level
-1]->node
;
709 if (btrfs_is_leaf(lower
))
710 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
712 lower_key
= &lower
->ptrs
[0].key
;
713 memcpy(&c
->ptrs
[0].key
, lower_key
, sizeof(struct btrfs_disk_key
));
714 btrfs_set_node_blockptr(c
, 0, path
->nodes
[level
- 1]->blocknr
);
715 /* the super has an extra ref to root->node */
716 btrfs_block_release(root
, root
->node
);
719 path
->nodes
[level
] = t
;
720 path
->slots
[level
] = 0;
725 * worker function to insert a single pointer in a node.
726 * the node should have enough room for the pointer already
728 * slot and level indicate where you want the key to go, and
729 * blocknr is the block the key points to.
731 * returns zero on success and < 0 on any error
733 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
734 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
735 *key
, u64 blocknr
, int slot
, int level
)
737 struct btrfs_node
*lower
;
740 BUG_ON(!path
->nodes
[level
]);
741 lower
= &path
->nodes
[level
]->node
;
742 nritems
= btrfs_header_nritems(&lower
->header
);
745 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
747 if (slot
!= nritems
) {
748 memmove(lower
->ptrs
+ slot
+ 1, lower
->ptrs
+ slot
,
749 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
751 memcpy(&lower
->ptrs
[slot
].key
, key
, sizeof(struct btrfs_disk_key
));
752 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
753 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
754 BUG_ON(list_empty(&path
->nodes
[level
]->dirty
));
759 * split the node at the specified level in path in two.
760 * The path is corrected to point to the appropriate node after the split
762 * Before splitting this tries to make some room in the node by pushing
763 * left and right, if either one works, it returns right away.
765 * returns 0 on success and < 0 on failure
767 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
768 *root
, struct btrfs_path
*path
, int level
)
770 struct btrfs_buffer
*t
;
771 struct btrfs_node
*c
;
772 struct btrfs_buffer
*split_buffer
;
773 struct btrfs_node
*split
;
779 t
= path
->nodes
[level
];
781 if (t
== root
->node
) {
782 /* trying to split the root, lets make a new one */
783 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
787 c_nritems
= btrfs_header_nritems(&c
->header
);
788 split_buffer
= btrfs_alloc_free_block(trans
, root
);
789 split
= &split_buffer
->node
;
790 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
791 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
792 btrfs_set_header_blocknr(&split
->header
, split_buffer
->blocknr
);
793 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
794 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
795 sizeof(split
->header
.fsid
));
796 mid
= (c_nritems
+ 1) / 2;
797 memcpy(split
->ptrs
, c
->ptrs
+ mid
,
798 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
799 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
800 btrfs_set_header_nritems(&c
->header
, mid
);
803 BUG_ON(list_empty(&t
->dirty
));
804 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
805 split_buffer
->blocknr
, path
->slots
[level
+ 1] + 1,
810 if (path
->slots
[level
] >= mid
) {
811 path
->slots
[level
] -= mid
;
812 btrfs_block_release(root
, t
);
813 path
->nodes
[level
] = split_buffer
;
814 path
->slots
[level
+ 1] += 1;
816 btrfs_block_release(root
, split_buffer
);
822 * push some data in the path leaf to the right, trying to free up at
823 * least data_size bytes. returns zero if the push worked, nonzero otherwise
825 * returns 1 if the push failed because the other node didn't have enough
826 * room, 0 if everything worked out and < 0 if there were major errors.
828 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
829 *root
, struct btrfs_path
*path
, int data_size
)
831 struct btrfs_buffer
*left_buf
= path
->nodes
[0];
832 struct btrfs_leaf
*left
= &left_buf
->leaf
;
833 struct btrfs_leaf
*right
;
834 struct btrfs_buffer
*right_buf
;
835 struct btrfs_buffer
*upper
;
841 struct btrfs_item
*item
;
845 slot
= path
->slots
[1];
846 if (!path
->nodes
[1]) {
849 upper
= path
->nodes
[1];
850 if (slot
>= btrfs_header_nritems(&upper
->node
.header
) - 1) {
853 right_buf
= read_tree_block(root
, btrfs_node_blockptr(&upper
->node
,
855 right
= &right_buf
->leaf
;
856 free_space
= btrfs_leaf_free_space(root
, right
);
857 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
858 btrfs_block_release(root
, right_buf
);
861 /* cow and double check */
862 btrfs_cow_block(trans
, root
, right_buf
, upper
, slot
+ 1, &right_buf
);
863 right
= &right_buf
->leaf
;
864 free_space
= btrfs_leaf_free_space(root
, right
);
865 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
866 btrfs_block_release(root
, right_buf
);
870 left_nritems
= btrfs_header_nritems(&left
->header
);
871 for (i
= left_nritems
- 1; i
>= 0; i
--) {
872 item
= left
->items
+ i
;
873 if (path
->slots
[0] == i
)
874 push_space
+= data_size
+ sizeof(*item
);
875 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
879 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
881 if (push_items
== 0) {
882 btrfs_block_release(root
, right_buf
);
885 right_nritems
= btrfs_header_nritems(&right
->header
);
886 /* push left to right */
887 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
888 push_space
-= leaf_data_end(root
, left
);
889 /* make room in the right data area */
890 memmove(btrfs_leaf_data(right
) + leaf_data_end(root
, right
) -
891 push_space
, btrfs_leaf_data(right
) + leaf_data_end(root
, right
),
892 BTRFS_LEAF_DATA_SIZE(root
) - leaf_data_end(root
, right
));
893 /* copy from the left data area */
894 memcpy(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
895 btrfs_leaf_data(left
) + leaf_data_end(root
, left
), push_space
);
896 memmove(right
->items
+ push_items
, right
->items
,
897 right_nritems
* sizeof(struct btrfs_item
));
898 /* copy the items from left to right */
899 memcpy(right
->items
, left
->items
+ left_nritems
- push_items
,
900 push_items
* sizeof(struct btrfs_item
));
902 /* update the item pointers */
903 right_nritems
+= push_items
;
904 btrfs_set_header_nritems(&right
->header
, right_nritems
);
905 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
906 for (i
= 0; i
< right_nritems
; i
++) {
907 btrfs_set_item_offset(right
->items
+ i
, push_space
-
908 btrfs_item_size(right
->items
+ i
));
909 push_space
= btrfs_item_offset(right
->items
+ i
);
911 left_nritems
-= push_items
;
912 btrfs_set_header_nritems(&left
->header
, left_nritems
);
914 BUG_ON(list_empty(&left_buf
->dirty
));
915 BUG_ON(list_empty(&right_buf
->dirty
));
916 memcpy(&upper
->node
.ptrs
[slot
+ 1].key
,
917 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
918 BUG_ON(list_empty(&upper
->dirty
));
920 /* then fixup the leaf pointer in the path */
921 if (path
->slots
[0] >= left_nritems
) {
922 path
->slots
[0] -= left_nritems
;
923 btrfs_block_release(root
, path
->nodes
[0]);
924 path
->nodes
[0] = right_buf
;
927 btrfs_block_release(root
, right_buf
);
932 * push some data in the path leaf to the left, trying to free up at
933 * least data_size bytes. returns zero if the push worked, nonzero otherwise
935 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
936 *root
, struct btrfs_path
*path
, int data_size
)
938 struct btrfs_buffer
*right_buf
= path
->nodes
[0];
939 struct btrfs_leaf
*right
= &right_buf
->leaf
;
940 struct btrfs_buffer
*t
;
941 struct btrfs_leaf
*left
;
947 struct btrfs_item
*item
;
948 u32 old_left_nritems
;
952 slot
= path
->slots
[1];
956 if (!path
->nodes
[1]) {
959 t
= read_tree_block(root
, btrfs_node_blockptr(&path
->nodes
[1]->node
,
962 free_space
= btrfs_leaf_free_space(root
, left
);
963 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
964 btrfs_block_release(root
, t
);
968 /* cow and double check */
969 btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
971 free_space
= btrfs_leaf_free_space(root
, left
);
972 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
973 btrfs_block_release(root
, t
);
977 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
978 item
= right
->items
+ i
;
979 if (path
->slots
[0] == i
)
980 push_space
+= data_size
+ sizeof(*item
);
981 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
985 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
987 if (push_items
== 0) {
988 btrfs_block_release(root
, t
);
991 /* push data from right to left */
992 memcpy(left
->items
+ btrfs_header_nritems(&left
->header
),
993 right
->items
, push_items
* sizeof(struct btrfs_item
));
994 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
995 btrfs_item_offset(right
->items
+ push_items
-1);
996 memcpy(btrfs_leaf_data(left
) + leaf_data_end(root
, left
) - push_space
,
997 btrfs_leaf_data(right
) +
998 btrfs_item_offset(right
->items
+ push_items
- 1),
1000 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1001 BUG_ON(old_left_nritems
< 0);
1003 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1004 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1005 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1006 (BTRFS_LEAF_DATA_SIZE(root
) -
1007 btrfs_item_offset(left
->items
+
1008 old_left_nritems
- 1)));
1010 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1012 /* fixup right node */
1013 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1014 leaf_data_end(root
, right
);
1015 memmove(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1016 push_space
, btrfs_leaf_data(right
) +
1017 leaf_data_end(root
, right
), push_space
);
1018 memmove(right
->items
, right
->items
+ push_items
,
1019 (btrfs_header_nritems(&right
->header
) - push_items
) *
1020 sizeof(struct btrfs_item
));
1021 btrfs_set_header_nritems(&right
->header
,
1022 btrfs_header_nritems(&right
->header
) -
1024 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1026 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1027 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1028 btrfs_item_size(right
->items
+ i
));
1029 push_space
= btrfs_item_offset(right
->items
+ i
);
1032 BUG_ON(list_empty(&t
->dirty
));
1033 BUG_ON(list_empty(&right_buf
->dirty
));
1035 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1039 /* then fixup the leaf pointer in the path */
1040 if (path
->slots
[0] < push_items
) {
1041 path
->slots
[0] += old_left_nritems
;
1042 btrfs_block_release(root
, path
->nodes
[0]);
1044 path
->slots
[1] -= 1;
1046 btrfs_block_release(root
, t
);
1047 path
->slots
[0] -= push_items
;
1049 BUG_ON(path
->slots
[0] < 0);
1054 * split the path's leaf in two, making sure there is at least data_size
1055 * available for the resulting leaf level of the path.
1057 * returns 0 if all went well and < 0 on failure.
1059 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1060 *root
, struct btrfs_path
*path
, int data_size
)
1062 struct btrfs_buffer
*l_buf
;
1063 struct btrfs_leaf
*l
;
1067 struct btrfs_leaf
*right
;
1068 struct btrfs_buffer
*right_buffer
;
1069 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1076 /* first try to make some room by pushing left and right */
1077 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1081 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1085 l_buf
= path
->nodes
[0];
1088 /* did the pushes work? */
1089 if (btrfs_leaf_free_space(root
, l
) >=
1090 sizeof(struct btrfs_item
) + data_size
)
1093 if (!path
->nodes
[1]) {
1094 ret
= insert_new_root(trans
, root
, path
, 1);
1098 slot
= path
->slots
[0];
1099 nritems
= btrfs_header_nritems(&l
->header
);
1100 mid
= (nritems
+ 1)/ 2;
1101 right_buffer
= btrfs_alloc_free_block(trans
, root
);
1102 BUG_ON(!right_buffer
);
1103 BUG_ON(mid
== nritems
);
1104 right
= &right_buffer
->leaf
;
1105 memset(&right
->header
, 0, sizeof(right
->header
));
1107 /* FIXME, just alloc a new leaf here */
1108 if (leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1109 BTRFS_LEAF_DATA_SIZE(root
))
1112 /* FIXME, just alloc a new leaf here */
1113 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1114 BTRFS_LEAF_DATA_SIZE(root
))
1117 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1118 btrfs_set_header_blocknr(&right
->header
, right_buffer
->blocknr
);
1119 btrfs_set_header_level(&right
->header
, 0);
1120 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1121 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1122 sizeof(right
->header
.fsid
));
1123 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1124 leaf_data_end(root
, l
);
1125 memcpy(right
->items
, l
->items
+ mid
,
1126 (nritems
- mid
) * sizeof(struct btrfs_item
));
1127 memcpy(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1128 data_copy_size
, btrfs_leaf_data(l
) +
1129 leaf_data_end(root
, l
), data_copy_size
);
1130 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1131 btrfs_item_end(l
->items
+ mid
);
1133 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1134 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1135 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1138 btrfs_set_header_nritems(&l
->header
, mid
);
1140 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1141 right_buffer
->blocknr
, path
->slots
[1] + 1, 1);
1144 BUG_ON(list_empty(&right_buffer
->dirty
));
1145 BUG_ON(list_empty(&l_buf
->dirty
));
1146 BUG_ON(path
->slots
[0] != slot
);
1148 btrfs_block_release(root
, path
->nodes
[0]);
1149 path
->nodes
[0] = right_buffer
;
1150 path
->slots
[0] -= mid
;
1151 path
->slots
[1] += 1;
1153 btrfs_block_release(root
, right_buffer
);
1154 BUG_ON(path
->slots
[0] < 0);
1159 * Given a key and some data, insert an item into the tree.
1160 * This does all the path init required, making room in the tree if needed.
1162 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1163 *root
, struct btrfs_path
*path
, struct btrfs_key
1164 *cpu_key
, u32 data_size
)
1169 struct btrfs_leaf
*leaf
;
1170 struct btrfs_buffer
*leaf_buf
;
1172 unsigned int data_end
;
1173 struct btrfs_disk_key disk_key
;
1175 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1177 /* create a root if there isn't one */
1180 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1187 slot_orig
= path
->slots
[0];
1188 leaf_buf
= path
->nodes
[0];
1189 leaf
= &leaf_buf
->leaf
;
1191 nritems
= btrfs_header_nritems(&leaf
->header
);
1192 data_end
= leaf_data_end(root
, leaf
);
1194 if (btrfs_leaf_free_space(root
, leaf
) <
1195 sizeof(struct btrfs_item
) + data_size
)
1198 slot
= path
->slots
[0];
1200 if (slot
!= nritems
) {
1202 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1205 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1207 /* first correct the data pointers */
1208 for (i
= slot
; i
< nritems
; i
++) {
1209 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1210 btrfs_set_item_offset(leaf
->items
+ i
,
1214 /* shift the items */
1215 memmove(leaf
->items
+ slot
+ 1, leaf
->items
+ slot
,
1216 (nritems
- slot
) * sizeof(struct btrfs_item
));
1218 /* shift the data */
1219 memmove(btrfs_leaf_data(leaf
) + data_end
- data_size
,
1220 btrfs_leaf_data(leaf
) +
1221 data_end
, old_data
- data_end
);
1222 data_end
= old_data
;
1224 /* setup the item for the new data */
1225 memcpy(&leaf
->items
[slot
].key
, &disk_key
,
1226 sizeof(struct btrfs_disk_key
));
1227 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1228 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1229 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1233 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1235 BUG_ON(list_empty(&leaf_buf
->dirty
));
1236 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1238 check_leaf(root
, path
, 0);
1244 * Given a key and some data, insert an item into the tree.
1245 * This does all the path init required, making room in the tree if needed.
1247 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1248 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1252 struct btrfs_path path
;
1255 btrfs_init_path(&path
);
1256 ret
= btrfs_insert_empty_item(trans
, root
, &path
, cpu_key
, data_size
);
1258 ptr
= btrfs_item_ptr(&path
.nodes
[0]->leaf
, path
.slots
[0], u8
);
1259 memcpy(ptr
, data
, data_size
);
1261 btrfs_release_path(root
, &path
);
1266 * delete the pointer from a given node.
1268 * If the delete empties a node, the node is removed from the tree,
1269 * continuing all the way the root if required. The root is converted into
1270 * a leaf if all the nodes are emptied.
1272 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1273 struct btrfs_path
*path
, int level
, int slot
)
1275 struct btrfs_node
*node
;
1276 struct btrfs_buffer
*parent
= path
->nodes
[level
];
1281 node
= &parent
->node
;
1282 nritems
= btrfs_header_nritems(&node
->header
);
1283 if (slot
!= nritems
-1) {
1284 memmove(node
->ptrs
+ slot
, node
->ptrs
+ slot
+ 1,
1285 sizeof(struct btrfs_key_ptr
) * (nritems
- slot
- 1));
1288 btrfs_set_header_nritems(&node
->header
, nritems
);
1289 if (nritems
== 0 && parent
== root
->node
) {
1290 BUG_ON(btrfs_header_level(&root
->node
->node
.header
) != 1);
1291 /* just turn the root into a leaf and break */
1292 btrfs_set_header_level(&root
->node
->node
.header
, 0);
1293 } else if (slot
== 0) {
1294 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1299 BUG_ON(list_empty(&parent
->dirty
));
1304 * delete the item at the leaf level in path. If that empties
1305 * the leaf, remove it from the tree
1307 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1308 struct btrfs_path
*path
)
1311 struct btrfs_leaf
*leaf
;
1312 struct btrfs_buffer
*leaf_buf
;
1319 leaf_buf
= path
->nodes
[0];
1320 leaf
= &leaf_buf
->leaf
;
1321 slot
= path
->slots
[0];
1322 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1323 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1324 nritems
= btrfs_header_nritems(&leaf
->header
);
1326 if (slot
!= nritems
- 1) {
1328 int data_end
= leaf_data_end(root
, leaf
);
1329 memmove(btrfs_leaf_data(leaf
) + data_end
+ dsize
,
1330 btrfs_leaf_data(leaf
) + data_end
,
1332 for (i
= slot
+ 1; i
< nritems
; i
++) {
1333 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1334 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1336 memmove(leaf
->items
+ slot
, leaf
->items
+ slot
+ 1,
1337 sizeof(struct btrfs_item
) *
1338 (nritems
- slot
- 1));
1340 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1342 /* delete the leaf if we've emptied it */
1344 if (leaf_buf
== root
->node
) {
1345 btrfs_set_header_level(&leaf
->header
, 0);
1346 BUG_ON(list_empty(&leaf_buf
->dirty
));
1348 clean_tree_block(trans
, root
, leaf_buf
);
1349 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1352 wret
= btrfs_free_extent(trans
, root
,
1353 leaf_buf
->blocknr
, 1, 1);
1358 int used
= leaf_space_used(leaf
, 0, nritems
);
1360 wret
= fixup_low_keys(trans
, root
, path
,
1361 &leaf
->items
[0].key
, 1);
1365 BUG_ON(list_empty(&leaf_buf
->dirty
));
1367 /* delete the leaf if it is mostly empty */
1368 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1369 /* push_leaf_left fixes the path.
1370 * make sure the path still points to our leaf
1371 * for possible call to del_ptr below
1373 slot
= path
->slots
[1];
1375 wret
= push_leaf_left(trans
, root
, path
, 1);
1378 if (path
->nodes
[0] == leaf_buf
&&
1379 btrfs_header_nritems(&leaf
->header
)) {
1380 wret
= push_leaf_right(trans
, root
, path
, 1);
1384 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1385 u64 blocknr
= leaf_buf
->blocknr
;
1386 clean_tree_block(trans
, root
, leaf_buf
);
1387 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1390 btrfs_block_release(root
, leaf_buf
);
1391 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1396 btrfs_block_release(root
, leaf_buf
);
1403 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1404 *root
, struct btrfs_path
*path
, u32 data_size
)
1409 struct btrfs_leaf
*leaf
;
1410 struct btrfs_buffer
*leaf_buf
;
1412 unsigned int data_end
;
1413 unsigned int old_data
;
1414 unsigned int old_size
;
1417 slot_orig
= path
->slots
[0];
1418 leaf_buf
= path
->nodes
[0];
1419 leaf
= &leaf_buf
->leaf
;
1421 nritems
= btrfs_header_nritems(&leaf
->header
);
1422 data_end
= leaf_data_end(root
, leaf
);
1424 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1426 slot
= path
->slots
[0];
1427 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1430 BUG_ON(slot
>= nritems
);
1433 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1435 /* first correct the data pointers */
1436 for (i
= slot
; i
< nritems
; i
++) {
1437 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1438 btrfs_set_item_offset(leaf
->items
+ i
,
1441 /* shift the data */
1442 memmove(btrfs_leaf_data(leaf
) + data_end
- data_size
,
1443 btrfs_leaf_data(leaf
) + data_end
, old_data
- data_end
);
1444 data_end
= old_data
;
1445 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1446 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1449 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1451 check_leaf(root
, path
, 0);
1456 * walk up the tree as far as required to find the next leaf.
1457 * returns 0 if it found something or 1 if there are no greater leaves.
1458 * returns < 0 on io errors.
1460 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1465 struct btrfs_buffer
*c
;
1466 struct btrfs_buffer
*next
= NULL
;
1468 while(level
< BTRFS_MAX_LEVEL
) {
1469 if (!path
->nodes
[level
])
1471 slot
= path
->slots
[level
] + 1;
1472 c
= path
->nodes
[level
];
1473 if (slot
>= btrfs_header_nritems(&c
->node
.header
)) {
1477 blocknr
= btrfs_node_blockptr(&c
->node
, slot
);
1479 btrfs_block_release(root
, next
);
1480 next
= read_tree_block(root
, blocknr
);
1483 path
->slots
[level
] = slot
;
1486 c
= path
->nodes
[level
];
1487 btrfs_block_release(root
, c
);
1488 path
->nodes
[level
] = next
;
1489 path
->slots
[level
] = 0;
1492 next
= read_tree_block(root
,
1493 btrfs_node_blockptr(&next
->node
, 0));