3 #include "kerncompat.h"
4 #include "radix-tree.h"
7 #include "print-tree.h"
9 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
10 *root
, struct btrfs_path
*path
, int level
);
11 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
12 *root
, struct btrfs_path
*path
, int data_size
);
13 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
14 *root
, struct btrfs_buffer
*dst
, struct btrfs_buffer
16 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
17 btrfs_root
*root
, struct btrfs_buffer
*dst_buf
,
18 struct btrfs_buffer
*src_buf
);
19 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
20 struct btrfs_path
*path
, int level
, int slot
);
22 inline void btrfs_init_path(struct btrfs_path
*p
)
24 memset(p
, 0, sizeof(*p
));
27 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
30 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
33 btrfs_block_release(root
, p
->nodes
[i
]);
35 memset(p
, 0, sizeof(*p
));
38 static int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
39 *root
, struct btrfs_buffer
*buf
, struct btrfs_buffer
40 *parent
, int parent_slot
, struct btrfs_buffer
43 struct btrfs_buffer
*cow
;
45 if (!list_empty(&buf
->dirty
)) {
49 cow
= btrfs_alloc_free_block(trans
, root
);
50 memcpy(&cow
->node
, &buf
->node
, root
->blocksize
);
51 btrfs_set_header_blocknr(&cow
->node
.header
, cow
->blocknr
);
52 btrfs_set_header_owner(&cow
->node
.header
, root
->root_key
.objectid
);
54 btrfs_inc_ref(trans
, root
, buf
);
55 if (buf
== root
->node
) {
58 if (buf
!= root
->commit_root
)
59 btrfs_free_extent(trans
, root
, buf
->blocknr
, 1, 1);
60 btrfs_block_release(root
, buf
);
62 btrfs_set_node_blockptr(&parent
->node
, parent_slot
,
64 BUG_ON(list_empty(&parent
->dirty
));
65 btrfs_free_extent(trans
, root
, buf
->blocknr
, 1, 1);
67 btrfs_block_release(root
, buf
);
72 * The leaf data grows from end-to-front in the node.
73 * this returns the address of the start of the last item,
74 * which is the stop of the leaf data stack
76 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
77 struct btrfs_leaf
*leaf
)
79 u32 nr
= btrfs_header_nritems(&leaf
->header
);
81 return BTRFS_LEAF_DATA_SIZE(root
);
82 return btrfs_item_offset(leaf
->items
+ nr
- 1);
86 * how many bytes are required to store the items in a leaf. start
87 * and nr indicate which items in the leaf to check. This totals up the
88 * space used both by the item structs and the item data
90 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
93 int nritems
= btrfs_header_nritems(&l
->header
);
96 if (nritems
< start
+ nr
)
103 data_len
= btrfs_item_end(l
->items
+ start
);
104 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
105 data_len
+= sizeof(struct btrfs_item
) * nr
;
110 * The space between the end of the leaf items and
111 * the start of the leaf data. IOW, how much room
112 * the leaf has left for both items and data
114 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
116 int nritems
= btrfs_header_nritems(&leaf
->header
);
117 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
121 * compare two keys in a memcmp fashion
123 int btrfs_comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
127 btrfs_disk_key_to_cpu(&k1
, disk
);
129 if (k1
.objectid
> k2
->objectid
)
131 if (k1
.objectid
< k2
->objectid
)
133 if (k1
.flags
> k2
->flags
)
135 if (k1
.flags
< k2
->flags
)
137 if (k1
.offset
> k2
->offset
)
139 if (k1
.offset
< k2
->offset
)
144 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
148 struct btrfs_node
*parent
= NULL
;
149 struct btrfs_node
*node
= &path
->nodes
[level
]->node
;
151 u32 nritems
= btrfs_header_nritems(&node
->header
);
153 if (path
->nodes
[level
+ 1])
154 parent
= &path
->nodes
[level
+ 1]->node
;
155 parent_slot
= path
->slots
[level
+ 1];
156 BUG_ON(nritems
== 0);
158 struct btrfs_disk_key
*parent_key
;
159 parent_key
= &parent
->ptrs
[parent_slot
].key
;
160 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
161 sizeof(struct btrfs_disk_key
)));
162 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
163 btrfs_header_blocknr(&node
->header
));
165 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
166 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
167 struct btrfs_key cpukey
;
168 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[i
+ 1].key
);
169 BUG_ON(btrfs_comp_keys(&node
->ptrs
[i
].key
, &cpukey
) >= 0);
174 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
178 struct btrfs_leaf
*leaf
= &path
->nodes
[level
]->leaf
;
179 struct btrfs_node
*parent
= NULL
;
181 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
183 if (path
->nodes
[level
+ 1])
184 parent
= &path
->nodes
[level
+ 1]->node
;
185 parent_slot
= path
->slots
[level
+ 1];
186 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
192 struct btrfs_disk_key
*parent_key
;
193 parent_key
= &parent
->ptrs
[parent_slot
].key
;
194 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
195 sizeof(struct btrfs_disk_key
)));
196 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
197 btrfs_header_blocknr(&leaf
->header
));
199 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
200 struct btrfs_key cpukey
;
201 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[i
+ 1].key
);
202 BUG_ON(btrfs_comp_keys(&leaf
->items
[i
].key
,
204 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) !=
205 btrfs_item_end(leaf
->items
+ i
+ 1));
207 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) +
208 btrfs_item_size(leaf
->items
+ i
) !=
209 BTRFS_LEAF_DATA_SIZE(root
));
215 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
219 return check_leaf(root
, path
, level
);
220 return check_node(root
, path
, level
);
224 * search for key in the array p. items p are item_size apart
225 * and there are 'max' items in p
226 * the slot in the array is returned via slot, and it points to
227 * the place where you would insert key if it is not found in
230 * slot may point to max if the key is bigger than all of the keys
232 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
239 struct btrfs_disk_key
*tmp
;
242 mid
= (low
+ high
) / 2;
243 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
244 ret
= btrfs_comp_keys(tmp
, key
);
260 * simple bin_search frontend that does the right thing for
263 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
265 if (btrfs_is_leaf(c
)) {
266 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
267 return generic_bin_search((void *)l
->items
,
268 sizeof(struct btrfs_item
),
269 key
, btrfs_header_nritems(&c
->header
),
272 return generic_bin_search((void *)c
->ptrs
,
273 sizeof(struct btrfs_key_ptr
),
274 key
, btrfs_header_nritems(&c
->header
),
280 static struct btrfs_buffer
*read_node_slot(struct btrfs_root
*root
,
281 struct btrfs_buffer
*parent_buf
,
284 struct btrfs_node
*node
= &parent_buf
->node
;
287 if (slot
>= btrfs_header_nritems(&node
->header
))
289 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
292 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
293 *root
, struct btrfs_path
*path
, int level
)
295 struct btrfs_buffer
*right_buf
;
296 struct btrfs_buffer
*mid_buf
;
297 struct btrfs_buffer
*left_buf
;
298 struct btrfs_buffer
*parent_buf
= NULL
;
299 struct btrfs_node
*right
= NULL
;
300 struct btrfs_node
*mid
;
301 struct btrfs_node
*left
= NULL
;
302 struct btrfs_node
*parent
= NULL
;
306 int orig_slot
= path
->slots
[level
];
312 mid_buf
= path
->nodes
[level
];
313 mid
= &mid_buf
->node
;
314 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
316 if (level
< BTRFS_MAX_LEVEL
- 1)
317 parent_buf
= path
->nodes
[level
+ 1];
318 pslot
= path
->slots
[level
+ 1];
321 * deal with the case where there is only one pointer in the root
322 * by promoting the node below to a root
325 struct btrfs_buffer
*child
;
326 u64 blocknr
= mid_buf
->blocknr
;
328 if (btrfs_header_nritems(&mid
->header
) != 1)
331 /* promote the child to a root */
332 child
= read_node_slot(root
, mid_buf
, 0);
335 path
->nodes
[level
] = NULL
;
336 /* once for the path */
337 btrfs_block_release(root
, mid_buf
);
338 /* once for the root ptr */
339 btrfs_block_release(root
, mid_buf
);
340 clean_tree_block(trans
, root
, mid_buf
);
341 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
343 parent
= &parent_buf
->node
;
345 if (btrfs_header_nritems(&mid
->header
) >
346 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
349 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
350 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
352 /* first, try to make some room in the middle buffer */
354 btrfs_cow_block(trans
, root
, left_buf
, parent_buf
, pslot
- 1,
356 left
= &left_buf
->node
;
357 orig_slot
+= btrfs_header_nritems(&left
->header
);
358 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
364 * then try to empty the right most buffer into the middle
367 btrfs_cow_block(trans
, root
, right_buf
, parent_buf
, pslot
+ 1,
369 right
= &right_buf
->node
;
370 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
373 if (btrfs_header_nritems(&right
->header
) == 0) {
374 u64 blocknr
= right_buf
->blocknr
;
375 btrfs_block_release(root
, right_buf
);
376 clean_tree_block(trans
, root
, right_buf
);
379 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
383 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
387 memcpy(&parent
->ptrs
[pslot
+ 1].key
,
389 sizeof(struct btrfs_disk_key
));
390 BUG_ON(list_empty(&parent_buf
->dirty
));
393 if (btrfs_header_nritems(&mid
->header
) == 1) {
395 * we're not allowed to leave a node with one item in the
396 * tree during a delete. A deletion from lower in the tree
397 * could try to delete the only pointer in this node.
398 * So, pull some keys from the left.
399 * There has to be a left pointer at this point because
400 * otherwise we would have pulled some pointers from the
404 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
409 if (btrfs_header_nritems(&mid
->header
) == 0) {
410 /* we've managed to empty the middle node, drop it */
411 u64 blocknr
= mid_buf
->blocknr
;
412 btrfs_block_release(root
, mid_buf
);
413 clean_tree_block(trans
, root
, mid_buf
);
416 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
419 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
423 /* update the parent key to reflect our changes */
424 memcpy(&parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
425 sizeof(struct btrfs_disk_key
));
426 BUG_ON(list_empty(&parent_buf
->dirty
));
429 /* update the path */
431 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
432 left_buf
->count
++; // released below
433 path
->nodes
[level
] = left_buf
;
434 path
->slots
[level
+ 1] -= 1;
435 path
->slots
[level
] = orig_slot
;
437 btrfs_block_release(root
, mid_buf
);
439 orig_slot
-= btrfs_header_nritems(&left
->header
);
440 path
->slots
[level
] = orig_slot
;
443 /* double check we haven't messed things up */
444 check_block(root
, path
, level
);
445 if (orig_ptr
!= btrfs_node_blockptr(&path
->nodes
[level
]->node
,
450 btrfs_block_release(root
, right_buf
);
452 btrfs_block_release(root
, left_buf
);
457 * look for key in the tree. path is filled in with nodes along the way
458 * if key is found, we return zero and you can find the item in the leaf
459 * level of the path (level 0)
461 * If the key isn't found, the path points to the slot where it should
462 * be inserted, and 1 is returned. If there are other errors during the
463 * search a negative error number is returned.
465 * if ins_len > 0, nodes and leaves will be split as we walk down the
466 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
469 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
470 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
473 struct btrfs_buffer
*b
;
474 struct btrfs_buffer
*cow_buf
;
475 struct btrfs_node
*c
;
484 level
= btrfs_header_level(&b
->node
.header
);
487 wret
= btrfs_cow_block(trans
, root
, b
, p
->nodes
[level
+
488 1], p
->slots
[level
+ 1],
492 BUG_ON(!cow
&& ins_len
);
495 ret
= check_block(root
, p
, level
);
498 ret
= bin_search(c
, key
, &slot
);
499 if (!btrfs_is_leaf(c
)) {
502 p
->slots
[level
] = slot
;
503 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) ==
504 BTRFS_NODEPTRS_PER_BLOCK(root
)) {
505 int sret
= split_node(trans
, root
, p
, level
);
511 slot
= p
->slots
[level
];
512 } else if (ins_len
< 0) {
513 int sret
= balance_level(trans
, root
, p
,
521 slot
= p
->slots
[level
];
522 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
524 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
526 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
527 p
->slots
[level
] = slot
;
528 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
529 sizeof(struct btrfs_item
) + ins_len
) {
530 int sret
= split_leaf(trans
, root
, p
, ins_len
);
535 BUG_ON(root
->node
->count
== 1);
539 BUG_ON(root
->node
->count
== 1);
544 * adjust the pointers going up the tree, starting at level
545 * making sure the right key of each node is points to 'key'.
546 * This is used after shifting pointers to the left, so it stops
547 * fixing up pointers when a given leaf/node is not in slot 0 of the
550 * If this fails to write a tree block, it returns -1, but continues
551 * fixing up the blocks in ram so the tree is consistent.
553 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
554 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
559 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
560 struct btrfs_node
*t
;
561 int tslot
= path
->slots
[i
];
564 t
= &path
->nodes
[i
]->node
;
565 memcpy(&t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
566 BUG_ON(list_empty(&path
->nodes
[i
]->dirty
));
574 * try to push data from one node into the next node left in the
577 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
578 * error, and > 0 if there was no room in the left hand block.
580 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
581 *root
, struct btrfs_buffer
*dst_buf
, struct
582 btrfs_buffer
*src_buf
)
584 struct btrfs_node
*src
= &src_buf
->node
;
585 struct btrfs_node
*dst
= &dst_buf
->node
;
591 src_nritems
= btrfs_header_nritems(&src
->header
);
592 dst_nritems
= btrfs_header_nritems(&dst
->header
);
593 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
594 if (push_items
<= 0) {
598 if (src_nritems
< push_items
)
599 push_items
= src_nritems
;
601 memcpy(dst
->ptrs
+ dst_nritems
, src
->ptrs
,
602 push_items
* sizeof(struct btrfs_key_ptr
));
603 if (push_items
< src_nritems
) {
604 memmove(src
->ptrs
, src
->ptrs
+ push_items
,
605 (src_nritems
- push_items
) *
606 sizeof(struct btrfs_key_ptr
));
608 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
609 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
610 BUG_ON(list_empty(&src_buf
->dirty
));
611 BUG_ON(list_empty(&dst_buf
->dirty
));
616 * try to push data from one node into the next node right in the
619 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
620 * error, and > 0 if there was no room in the right hand block.
622 * this will only push up to 1/2 the contents of the left node over
624 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
625 btrfs_root
*root
, struct btrfs_buffer
*dst_buf
,
626 struct btrfs_buffer
*src_buf
)
628 struct btrfs_node
*src
= &src_buf
->node
;
629 struct btrfs_node
*dst
= &dst_buf
->node
;
636 src_nritems
= btrfs_header_nritems(&src
->header
);
637 dst_nritems
= btrfs_header_nritems(&dst
->header
);
638 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
639 if (push_items
<= 0) {
643 max_push
= src_nritems
/ 2 + 1;
644 /* don't try to empty the node */
645 if (max_push
> src_nritems
)
647 if (max_push
< push_items
)
648 push_items
= max_push
;
650 memmove(dst
->ptrs
+ push_items
, dst
->ptrs
,
651 dst_nritems
* sizeof(struct btrfs_key_ptr
));
652 memcpy(dst
->ptrs
, src
->ptrs
+ src_nritems
- push_items
,
653 push_items
* sizeof(struct btrfs_key_ptr
));
655 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
656 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
658 BUG_ON(list_empty(&src_buf
->dirty
));
659 BUG_ON(list_empty(&dst_buf
->dirty
));
664 * helper function to insert a new root level in the tree.
665 * A new node is allocated, and a single item is inserted to
666 * point to the existing root
668 * returns zero on success or < 0 on failure.
670 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
671 *root
, struct btrfs_path
*path
, int level
)
673 struct btrfs_buffer
*t
;
674 struct btrfs_node
*lower
;
675 struct btrfs_node
*c
;
676 struct btrfs_disk_key
*lower_key
;
678 BUG_ON(path
->nodes
[level
]);
679 BUG_ON(path
->nodes
[level
-1] != root
->node
);
681 t
= btrfs_alloc_free_block(trans
, root
);
683 memset(c
, 0, root
->blocksize
);
684 btrfs_set_header_nritems(&c
->header
, 1);
685 btrfs_set_header_level(&c
->header
, level
);
686 btrfs_set_header_blocknr(&c
->header
, t
->blocknr
);
687 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
688 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
689 sizeof(c
->header
.fsid
));
690 lower
= &path
->nodes
[level
-1]->node
;
691 if (btrfs_is_leaf(lower
))
692 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
694 lower_key
= &lower
->ptrs
[0].key
;
695 memcpy(&c
->ptrs
[0].key
, lower_key
, sizeof(struct btrfs_disk_key
));
696 btrfs_set_node_blockptr(c
, 0, path
->nodes
[level
- 1]->blocknr
);
697 /* the super has an extra ref to root->node */
698 btrfs_block_release(root
, root
->node
);
701 path
->nodes
[level
] = t
;
702 path
->slots
[level
] = 0;
707 * worker function to insert a single pointer in a node.
708 * the node should have enough room for the pointer already
710 * slot and level indicate where you want the key to go, and
711 * blocknr is the block the key points to.
713 * returns zero on success and < 0 on any error
715 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
716 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
717 *key
, u64 blocknr
, int slot
, int level
)
719 struct btrfs_node
*lower
;
722 BUG_ON(!path
->nodes
[level
]);
723 lower
= &path
->nodes
[level
]->node
;
724 nritems
= btrfs_header_nritems(&lower
->header
);
727 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
729 if (slot
!= nritems
) {
730 memmove(lower
->ptrs
+ slot
+ 1, lower
->ptrs
+ slot
,
731 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
733 memcpy(&lower
->ptrs
[slot
].key
, key
, sizeof(struct btrfs_disk_key
));
734 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
735 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
736 BUG_ON(list_empty(&path
->nodes
[level
]->dirty
));
741 * split the node at the specified level in path in two.
742 * The path is corrected to point to the appropriate node after the split
744 * Before splitting this tries to make some room in the node by pushing
745 * left and right, if either one works, it returns right away.
747 * returns 0 on success and < 0 on failure
749 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
750 *root
, struct btrfs_path
*path
, int level
)
752 struct btrfs_buffer
*t
;
753 struct btrfs_node
*c
;
754 struct btrfs_buffer
*split_buffer
;
755 struct btrfs_node
*split
;
761 t
= path
->nodes
[level
];
763 if (t
== root
->node
) {
764 /* trying to split the root, lets make a new one */
765 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
769 c_nritems
= btrfs_header_nritems(&c
->header
);
770 split_buffer
= btrfs_alloc_free_block(trans
, root
);
771 split
= &split_buffer
->node
;
772 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
773 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
774 btrfs_set_header_blocknr(&split
->header
, split_buffer
->blocknr
);
775 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
776 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
777 sizeof(split
->header
.fsid
));
778 mid
= (c_nritems
+ 1) / 2;
779 memcpy(split
->ptrs
, c
->ptrs
+ mid
,
780 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
781 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
782 btrfs_set_header_nritems(&c
->header
, mid
);
785 BUG_ON(list_empty(&t
->dirty
));
786 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
787 split_buffer
->blocknr
, path
->slots
[level
+ 1] + 1,
792 if (path
->slots
[level
] >= mid
) {
793 path
->slots
[level
] -= mid
;
794 btrfs_block_release(root
, t
);
795 path
->nodes
[level
] = split_buffer
;
796 path
->slots
[level
+ 1] += 1;
798 btrfs_block_release(root
, split_buffer
);
804 * push some data in the path leaf to the right, trying to free up at
805 * least data_size bytes. returns zero if the push worked, nonzero otherwise
807 * returns 1 if the push failed because the other node didn't have enough
808 * room, 0 if everything worked out and < 0 if there were major errors.
810 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
811 *root
, struct btrfs_path
*path
, int data_size
)
813 struct btrfs_buffer
*left_buf
= path
->nodes
[0];
814 struct btrfs_leaf
*left
= &left_buf
->leaf
;
815 struct btrfs_leaf
*right
;
816 struct btrfs_buffer
*right_buf
;
817 struct btrfs_buffer
*upper
;
823 struct btrfs_item
*item
;
827 slot
= path
->slots
[1];
828 if (!path
->nodes
[1]) {
831 upper
= path
->nodes
[1];
832 if (slot
>= btrfs_header_nritems(&upper
->node
.header
) - 1) {
835 right_buf
= read_tree_block(root
, btrfs_node_blockptr(&upper
->node
,
837 right
= &right_buf
->leaf
;
838 free_space
= btrfs_leaf_free_space(root
, right
);
839 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
840 btrfs_block_release(root
, right_buf
);
843 /* cow and double check */
844 btrfs_cow_block(trans
, root
, right_buf
, upper
, slot
+ 1, &right_buf
);
845 right
= &right_buf
->leaf
;
846 free_space
= btrfs_leaf_free_space(root
, right
);
847 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
848 btrfs_block_release(root
, right_buf
);
852 left_nritems
= btrfs_header_nritems(&left
->header
);
853 for (i
= left_nritems
- 1; i
>= 0; i
--) {
854 item
= left
->items
+ i
;
855 if (path
->slots
[0] == i
)
856 push_space
+= data_size
+ sizeof(*item
);
857 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
861 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
863 if (push_items
== 0) {
864 btrfs_block_release(root
, right_buf
);
867 right_nritems
= btrfs_header_nritems(&right
->header
);
868 /* push left to right */
869 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
870 push_space
-= leaf_data_end(root
, left
);
871 /* make room in the right data area */
872 memmove(btrfs_leaf_data(right
) + leaf_data_end(root
, right
) -
873 push_space
, btrfs_leaf_data(right
) + leaf_data_end(root
, right
),
874 BTRFS_LEAF_DATA_SIZE(root
) - leaf_data_end(root
, right
));
875 /* copy from the left data area */
876 memcpy(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
877 btrfs_leaf_data(left
) + leaf_data_end(root
, left
), push_space
);
878 memmove(right
->items
+ push_items
, right
->items
,
879 right_nritems
* sizeof(struct btrfs_item
));
880 /* copy the items from left to right */
881 memcpy(right
->items
, left
->items
+ left_nritems
- push_items
,
882 push_items
* sizeof(struct btrfs_item
));
884 /* update the item pointers */
885 right_nritems
+= push_items
;
886 btrfs_set_header_nritems(&right
->header
, right_nritems
);
887 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
888 for (i
= 0; i
< right_nritems
; i
++) {
889 btrfs_set_item_offset(right
->items
+ i
, push_space
-
890 btrfs_item_size(right
->items
+ i
));
891 push_space
= btrfs_item_offset(right
->items
+ i
);
893 left_nritems
-= push_items
;
894 btrfs_set_header_nritems(&left
->header
, left_nritems
);
896 BUG_ON(list_empty(&left_buf
->dirty
));
897 BUG_ON(list_empty(&right_buf
->dirty
));
898 memcpy(&upper
->node
.ptrs
[slot
+ 1].key
,
899 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
900 BUG_ON(list_empty(&upper
->dirty
));
902 /* then fixup the leaf pointer in the path */
903 if (path
->slots
[0] >= left_nritems
) {
904 path
->slots
[0] -= left_nritems
;
905 btrfs_block_release(root
, path
->nodes
[0]);
906 path
->nodes
[0] = right_buf
;
909 btrfs_block_release(root
, right_buf
);
914 * push some data in the path leaf to the left, trying to free up at
915 * least data_size bytes. returns zero if the push worked, nonzero otherwise
917 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
918 *root
, struct btrfs_path
*path
, int data_size
)
920 struct btrfs_buffer
*right_buf
= path
->nodes
[0];
921 struct btrfs_leaf
*right
= &right_buf
->leaf
;
922 struct btrfs_buffer
*t
;
923 struct btrfs_leaf
*left
;
929 struct btrfs_item
*item
;
930 u32 old_left_nritems
;
934 slot
= path
->slots
[1];
938 if (!path
->nodes
[1]) {
941 t
= read_tree_block(root
, btrfs_node_blockptr(&path
->nodes
[1]->node
,
944 free_space
= btrfs_leaf_free_space(root
, left
);
945 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
946 btrfs_block_release(root
, t
);
950 /* cow and double check */
951 btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
953 free_space
= btrfs_leaf_free_space(root
, left
);
954 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
955 btrfs_block_release(root
, t
);
959 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
960 item
= right
->items
+ i
;
961 if (path
->slots
[0] == i
)
962 push_space
+= data_size
+ sizeof(*item
);
963 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
967 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
969 if (push_items
== 0) {
970 btrfs_block_release(root
, t
);
973 /* push data from right to left */
974 memcpy(left
->items
+ btrfs_header_nritems(&left
->header
),
975 right
->items
, push_items
* sizeof(struct btrfs_item
));
976 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
977 btrfs_item_offset(right
->items
+ push_items
-1);
978 memcpy(btrfs_leaf_data(left
) + leaf_data_end(root
, left
) - push_space
,
979 btrfs_leaf_data(right
) +
980 btrfs_item_offset(right
->items
+ push_items
- 1),
982 old_left_nritems
= btrfs_header_nritems(&left
->header
);
983 BUG_ON(old_left_nritems
< 0);
985 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
986 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
987 btrfs_set_item_offset(left
->items
+ i
, ioff
-
988 (BTRFS_LEAF_DATA_SIZE(root
) -
989 btrfs_item_offset(left
->items
+
990 old_left_nritems
- 1)));
992 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
994 /* fixup right node */
995 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
996 leaf_data_end(root
, right
);
997 memmove(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
998 push_space
, btrfs_leaf_data(right
) +
999 leaf_data_end(root
, right
), push_space
);
1000 memmove(right
->items
, right
->items
+ push_items
,
1001 (btrfs_header_nritems(&right
->header
) - push_items
) *
1002 sizeof(struct btrfs_item
));
1003 btrfs_set_header_nritems(&right
->header
,
1004 btrfs_header_nritems(&right
->header
) -
1006 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1008 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1009 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1010 btrfs_item_size(right
->items
+ i
));
1011 push_space
= btrfs_item_offset(right
->items
+ i
);
1014 BUG_ON(list_empty(&t
->dirty
));
1015 BUG_ON(list_empty(&right_buf
->dirty
));
1017 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1021 /* then fixup the leaf pointer in the path */
1022 if (path
->slots
[0] < push_items
) {
1023 path
->slots
[0] += old_left_nritems
;
1024 btrfs_block_release(root
, path
->nodes
[0]);
1026 path
->slots
[1] -= 1;
1028 btrfs_block_release(root
, t
);
1029 path
->slots
[0] -= push_items
;
1031 BUG_ON(path
->slots
[0] < 0);
1036 * split the path's leaf in two, making sure there is at least data_size
1037 * available for the resulting leaf level of the path.
1039 * returns 0 if all went well and < 0 on failure.
1041 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1042 *root
, struct btrfs_path
*path
, int data_size
)
1044 struct btrfs_buffer
*l_buf
;
1045 struct btrfs_leaf
*l
;
1049 struct btrfs_leaf
*right
;
1050 struct btrfs_buffer
*right_buffer
;
1051 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1058 /* first try to make some room by pushing left and right */
1059 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1063 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1067 l_buf
= path
->nodes
[0];
1070 /* did the pushes work? */
1071 if (btrfs_leaf_free_space(root
, l
) >=
1072 sizeof(struct btrfs_item
) + data_size
)
1075 if (!path
->nodes
[1]) {
1076 ret
= insert_new_root(trans
, root
, path
, 1);
1080 slot
= path
->slots
[0];
1081 nritems
= btrfs_header_nritems(&l
->header
);
1082 mid
= (nritems
+ 1)/ 2;
1083 right_buffer
= btrfs_alloc_free_block(trans
, root
);
1084 BUG_ON(!right_buffer
);
1085 BUG_ON(mid
== nritems
);
1086 right
= &right_buffer
->leaf
;
1087 memset(&right
->header
, 0, sizeof(right
->header
));
1089 /* FIXME, just alloc a new leaf here */
1090 if (leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1091 BTRFS_LEAF_DATA_SIZE(root
))
1094 /* FIXME, just alloc a new leaf here */
1095 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1096 BTRFS_LEAF_DATA_SIZE(root
))
1099 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1100 btrfs_set_header_blocknr(&right
->header
, right_buffer
->blocknr
);
1101 btrfs_set_header_level(&right
->header
, 0);
1102 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1103 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1104 sizeof(right
->header
.fsid
));
1105 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1106 leaf_data_end(root
, l
);
1107 memcpy(right
->items
, l
->items
+ mid
,
1108 (nritems
- mid
) * sizeof(struct btrfs_item
));
1109 memcpy(btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1110 data_copy_size
, btrfs_leaf_data(l
) +
1111 leaf_data_end(root
, l
), data_copy_size
);
1112 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1113 btrfs_item_end(l
->items
+ mid
);
1115 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1116 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1117 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1120 btrfs_set_header_nritems(&l
->header
, mid
);
1122 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1123 right_buffer
->blocknr
, path
->slots
[1] + 1, 1);
1126 BUG_ON(list_empty(&right_buffer
->dirty
));
1127 BUG_ON(list_empty(&l_buf
->dirty
));
1128 BUG_ON(path
->slots
[0] != slot
);
1130 btrfs_block_release(root
, path
->nodes
[0]);
1131 path
->nodes
[0] = right_buffer
;
1132 path
->slots
[0] -= mid
;
1133 path
->slots
[1] += 1;
1135 btrfs_block_release(root
, right_buffer
);
1136 BUG_ON(path
->slots
[0] < 0);
1141 * Given a key and some data, insert an item into the tree.
1142 * This does all the path init required, making room in the tree if needed.
1144 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1145 *root
, struct btrfs_path
*path
, struct btrfs_key
1146 *cpu_key
, u32 data_size
)
1151 struct btrfs_leaf
*leaf
;
1152 struct btrfs_buffer
*leaf_buf
;
1154 unsigned int data_end
;
1155 struct btrfs_disk_key disk_key
;
1157 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1159 /* create a root if there isn't one */
1162 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1169 slot_orig
= path
->slots
[0];
1170 leaf_buf
= path
->nodes
[0];
1171 leaf
= &leaf_buf
->leaf
;
1173 nritems
= btrfs_header_nritems(&leaf
->header
);
1174 data_end
= leaf_data_end(root
, leaf
);
1176 if (btrfs_leaf_free_space(root
, leaf
) <
1177 sizeof(struct btrfs_item
) + data_size
)
1180 slot
= path
->slots
[0];
1182 if (slot
!= nritems
) {
1184 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1187 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1189 /* first correct the data pointers */
1190 for (i
= slot
; i
< nritems
; i
++) {
1191 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1192 btrfs_set_item_offset(leaf
->items
+ i
,
1196 /* shift the items */
1197 memmove(leaf
->items
+ slot
+ 1, leaf
->items
+ slot
,
1198 (nritems
- slot
) * sizeof(struct btrfs_item
));
1200 /* shift the data */
1201 memmove(btrfs_leaf_data(leaf
) + data_end
- data_size
,
1202 btrfs_leaf_data(leaf
) +
1203 data_end
, old_data
- data_end
);
1204 data_end
= old_data
;
1206 /* setup the item for the new data */
1207 memcpy(&leaf
->items
[slot
].key
, &disk_key
,
1208 sizeof(struct btrfs_disk_key
));
1209 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1210 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1211 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1215 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1217 BUG_ON(list_empty(&leaf_buf
->dirty
));
1218 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1220 check_leaf(root
, path
, 0);
1226 * Given a key and some data, insert an item into the tree.
1227 * This does all the path init required, making room in the tree if needed.
1229 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1230 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1234 struct btrfs_path path
;
1237 btrfs_init_path(&path
);
1238 ret
= btrfs_insert_empty_item(trans
, root
, &path
, cpu_key
, data_size
);
1240 ptr
= btrfs_item_ptr(&path
.nodes
[0]->leaf
, path
.slots
[0], u8
);
1241 memcpy(ptr
, data
, data_size
);
1243 btrfs_release_path(root
, &path
);
1248 * delete the pointer from a given node.
1250 * If the delete empties a node, the node is removed from the tree,
1251 * continuing all the way the root if required. The root is converted into
1252 * a leaf if all the nodes are emptied.
1254 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1255 struct btrfs_path
*path
, int level
, int slot
)
1257 struct btrfs_node
*node
;
1258 struct btrfs_buffer
*parent
= path
->nodes
[level
];
1263 node
= &parent
->node
;
1264 nritems
= btrfs_header_nritems(&node
->header
);
1265 if (slot
!= nritems
-1) {
1266 memmove(node
->ptrs
+ slot
, node
->ptrs
+ slot
+ 1,
1267 sizeof(struct btrfs_key_ptr
) * (nritems
- slot
- 1));
1270 btrfs_set_header_nritems(&node
->header
, nritems
);
1271 if (nritems
== 0 && parent
== root
->node
) {
1272 BUG_ON(btrfs_header_level(&root
->node
->node
.header
) != 1);
1273 /* just turn the root into a leaf and break */
1274 btrfs_set_header_level(&root
->node
->node
.header
, 0);
1275 } else if (slot
== 0) {
1276 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1281 BUG_ON(list_empty(&parent
->dirty
));
1286 * delete the item at the leaf level in path. If that empties
1287 * the leaf, remove it from the tree
1289 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1290 struct btrfs_path
*path
)
1293 struct btrfs_leaf
*leaf
;
1294 struct btrfs_buffer
*leaf_buf
;
1301 leaf_buf
= path
->nodes
[0];
1302 leaf
= &leaf_buf
->leaf
;
1303 slot
= path
->slots
[0];
1304 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1305 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1306 nritems
= btrfs_header_nritems(&leaf
->header
);
1308 if (slot
!= nritems
- 1) {
1310 int data_end
= leaf_data_end(root
, leaf
);
1311 memmove(btrfs_leaf_data(leaf
) + data_end
+ dsize
,
1312 btrfs_leaf_data(leaf
) + data_end
,
1314 for (i
= slot
+ 1; i
< nritems
; i
++) {
1315 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1316 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1318 memmove(leaf
->items
+ slot
, leaf
->items
+ slot
+ 1,
1319 sizeof(struct btrfs_item
) *
1320 (nritems
- slot
- 1));
1322 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1324 /* delete the leaf if we've emptied it */
1326 if (leaf_buf
== root
->node
) {
1327 btrfs_set_header_level(&leaf
->header
, 0);
1328 BUG_ON(list_empty(&leaf_buf
->dirty
));
1330 clean_tree_block(trans
, root
, leaf_buf
);
1331 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1334 wret
= btrfs_free_extent(trans
, root
,
1335 leaf_buf
->blocknr
, 1, 1);
1340 int used
= leaf_space_used(leaf
, 0, nritems
);
1342 wret
= fixup_low_keys(trans
, root
, path
,
1343 &leaf
->items
[0].key
, 1);
1347 BUG_ON(list_empty(&leaf_buf
->dirty
));
1349 /* delete the leaf if it is mostly empty */
1350 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1351 /* push_leaf_left fixes the path.
1352 * make sure the path still points to our leaf
1353 * for possible call to del_ptr below
1355 slot
= path
->slots
[1];
1357 wret
= push_leaf_left(trans
, root
, path
, 1);
1360 if (path
->nodes
[0] == leaf_buf
&&
1361 btrfs_header_nritems(&leaf
->header
)) {
1362 wret
= push_leaf_right(trans
, root
, path
, 1);
1366 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1367 u64 blocknr
= leaf_buf
->blocknr
;
1368 clean_tree_block(trans
, root
, leaf_buf
);
1369 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1372 btrfs_block_release(root
, leaf_buf
);
1373 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1378 btrfs_block_release(root
, leaf_buf
);
1385 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1386 *root
, struct btrfs_path
*path
, u32 data_size
)
1391 struct btrfs_leaf
*leaf
;
1392 struct btrfs_buffer
*leaf_buf
;
1394 unsigned int data_end
;
1395 unsigned int old_data
;
1396 unsigned int old_size
;
1399 slot_orig
= path
->slots
[0];
1400 leaf_buf
= path
->nodes
[0];
1401 leaf
= &leaf_buf
->leaf
;
1403 nritems
= btrfs_header_nritems(&leaf
->header
);
1404 data_end
= leaf_data_end(root
, leaf
);
1406 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1408 slot
= path
->slots
[0];
1409 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1412 BUG_ON(slot
>= nritems
);
1415 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1417 /* first correct the data pointers */
1418 for (i
= slot
; i
< nritems
; i
++) {
1419 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1420 btrfs_set_item_offset(leaf
->items
+ i
,
1423 /* shift the data */
1424 memmove(btrfs_leaf_data(leaf
) + data_end
- data_size
,
1425 btrfs_leaf_data(leaf
) + data_end
, old_data
- data_end
);
1426 data_end
= old_data
;
1427 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1428 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1431 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1433 check_leaf(root
, path
, 0);
1438 * walk up the tree as far as required to find the next leaf.
1439 * returns 0 if it found something or 1 if there are no greater leaves.
1440 * returns < 0 on io errors.
1442 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1447 struct btrfs_buffer
*c
;
1448 struct btrfs_buffer
*next
= NULL
;
1450 while(level
< BTRFS_MAX_LEVEL
) {
1451 if (!path
->nodes
[level
])
1453 slot
= path
->slots
[level
] + 1;
1454 c
= path
->nodes
[level
];
1455 if (slot
>= btrfs_header_nritems(&c
->node
.header
)) {
1459 blocknr
= btrfs_node_blockptr(&c
->node
, slot
);
1461 btrfs_block_release(root
, next
);
1462 next
= read_tree_block(root
, blocknr
);
1465 path
->slots
[level
] = slot
;
1468 c
= path
->nodes
[level
];
1469 btrfs_block_release(root
, c
);
1470 path
->nodes
[level
] = next
;
1471 path
->slots
[level
] = 0;
1474 next
= read_tree_block(root
,
1475 btrfs_node_blockptr(&next
->node
, 0));