1 #include <linux/module.h>
4 #include "transaction.h"
6 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
7 *root
, struct btrfs_path
*path
, int level
);
8 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
9 *root
, struct btrfs_path
*path
, int data_size
);
10 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
11 *root
, struct buffer_head
*dst
, struct buffer_head
13 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
14 btrfs_root
*root
, struct buffer_head
*dst_buf
,
15 struct buffer_head
*src_buf
);
16 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
17 struct btrfs_path
*path
, int level
, int slot
);
19 struct btrfs_path
*btrfs_alloc_path(void)
21 return kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
24 void btrfs_free_path(struct btrfs_path
*p
)
26 kmem_cache_free(btrfs_path_cachep
, p
);
29 inline void btrfs_init_path(struct btrfs_path
*p
)
31 memset(p
, 0, sizeof(*p
));
34 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
37 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
40 btrfs_block_release(root
, p
->nodes
[i
]);
42 memset(p
, 0, sizeof(*p
));
45 static int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
46 *root
, struct buffer_head
*buf
, struct buffer_head
47 *parent
, int parent_slot
, struct buffer_head
50 struct buffer_head
*cow
;
51 struct btrfs_node
*cow_node
;
53 if (btrfs_header_generation(btrfs_buffer_header(buf
)) ==
58 cow
= btrfs_alloc_free_block(trans
, root
);
59 cow_node
= btrfs_buffer_node(cow
);
60 if (buf
->b_size
!= root
->blocksize
|| cow
->b_size
!= root
->blocksize
)
62 memcpy(cow_node
, btrfs_buffer_node(buf
), root
->blocksize
);
63 btrfs_set_header_blocknr(&cow_node
->header
, cow
->b_blocknr
);
64 btrfs_set_header_generation(&cow_node
->header
, trans
->transid
);
65 btrfs_inc_ref(trans
, root
, buf
);
66 if (buf
== root
->node
) {
69 if (buf
!= root
->commit_root
) {
70 btrfs_free_extent(trans
, root
, buf
->b_blocknr
, 1, 1);
72 btrfs_block_release(root
, buf
);
74 btrfs_set_node_blockptr(btrfs_buffer_node(parent
), parent_slot
,
76 btrfs_mark_buffer_dirty(parent
);
77 btrfs_free_extent(trans
, root
, buf
->b_blocknr
, 1, 1);
79 btrfs_block_release(root
, buf
);
85 * The leaf data grows from end-to-front in the node.
86 * this returns the address of the start of the last item,
87 * which is the stop of the leaf data stack
89 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
90 struct btrfs_leaf
*leaf
)
92 u32 nr
= btrfs_header_nritems(&leaf
->header
);
94 return BTRFS_LEAF_DATA_SIZE(root
);
95 return btrfs_item_offset(leaf
->items
+ nr
- 1);
99 * The space between the end of the leaf items and
100 * the start of the leaf data. IOW, how much room
101 * the leaf has left for both items and data
103 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
105 int data_end
= leaf_data_end(root
, leaf
);
106 int nritems
= btrfs_header_nritems(&leaf
->header
);
107 char *items_end
= (char *)(leaf
->items
+ nritems
+ 1);
108 return (char *)(btrfs_leaf_data(leaf
) + data_end
) - (char *)items_end
;
112 * compare two keys in a memcmp fashion
114 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
118 btrfs_disk_key_to_cpu(&k1
, disk
);
120 if (k1
.objectid
> k2
->objectid
)
122 if (k1
.objectid
< k2
->objectid
)
124 if (k1
.offset
> k2
->offset
)
126 if (k1
.offset
< k2
->offset
)
128 if (k1
.flags
> k2
->flags
)
130 if (k1
.flags
< k2
->flags
)
135 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
139 struct btrfs_node
*parent
= NULL
;
140 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
142 u32 nritems
= btrfs_header_nritems(&node
->header
);
144 if (path
->nodes
[level
+ 1])
145 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
146 parent_slot
= path
->slots
[level
+ 1];
147 BUG_ON(nritems
== 0);
149 struct btrfs_disk_key
*parent_key
;
150 parent_key
= &parent
->ptrs
[parent_slot
].key
;
151 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
152 sizeof(struct btrfs_disk_key
)));
153 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
154 btrfs_header_blocknr(&node
->header
));
156 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
157 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
158 struct btrfs_key cpukey
;
159 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[i
+ 1].key
);
160 BUG_ON(comp_keys(&node
->ptrs
[i
].key
, &cpukey
) >= 0);
165 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
169 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[level
]);
170 struct btrfs_node
*parent
= NULL
;
172 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
174 if (path
->nodes
[level
+ 1])
175 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
176 parent_slot
= path
->slots
[level
+ 1];
177 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
183 struct btrfs_disk_key
*parent_key
;
184 parent_key
= &parent
->ptrs
[parent_slot
].key
;
185 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
186 sizeof(struct btrfs_disk_key
)));
187 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
188 btrfs_header_blocknr(&leaf
->header
));
190 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
191 struct btrfs_key cpukey
;
192 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[i
+ 1].key
);
193 BUG_ON(comp_keys(&leaf
->items
[i
].key
,
195 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) !=
196 btrfs_item_end(leaf
->items
+ i
+ 1));
198 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) +
199 btrfs_item_size(leaf
->items
+ i
) !=
200 BTRFS_LEAF_DATA_SIZE(root
));
206 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
210 return check_leaf(root
, path
, level
);
211 return check_node(root
, path
, level
);
215 * search for key in the array p. items p are item_size apart
216 * and there are 'max' items in p
217 * the slot in the array is returned via slot, and it points to
218 * the place where you would insert key if it is not found in
221 * slot may point to max if the key is bigger than all of the keys
223 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
230 struct btrfs_disk_key
*tmp
;
233 mid
= (low
+ high
) / 2;
234 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
235 ret
= comp_keys(tmp
, key
);
251 * simple bin_search frontend that does the right thing for
254 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
256 if (btrfs_is_leaf(c
)) {
257 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
258 return generic_bin_search((void *)l
->items
,
259 sizeof(struct btrfs_item
),
260 key
, btrfs_header_nritems(&c
->header
),
263 return generic_bin_search((void *)c
->ptrs
,
264 sizeof(struct btrfs_key_ptr
),
265 key
, btrfs_header_nritems(&c
->header
),
271 static struct buffer_head
*read_node_slot(struct btrfs_root
*root
,
272 struct buffer_head
*parent_buf
,
275 struct btrfs_node
*node
= btrfs_buffer_node(parent_buf
);
278 if (slot
>= btrfs_header_nritems(&node
->header
))
280 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
283 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
284 *root
, struct btrfs_path
*path
, int level
)
286 struct buffer_head
*right_buf
;
287 struct buffer_head
*mid_buf
;
288 struct buffer_head
*left_buf
;
289 struct buffer_head
*parent_buf
= NULL
;
290 struct btrfs_node
*right
= NULL
;
291 struct btrfs_node
*mid
;
292 struct btrfs_node
*left
= NULL
;
293 struct btrfs_node
*parent
= NULL
;
297 int orig_slot
= path
->slots
[level
];
303 mid_buf
= path
->nodes
[level
];
304 mid
= btrfs_buffer_node(mid_buf
);
305 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
307 if (level
< BTRFS_MAX_LEVEL
- 1)
308 parent_buf
= path
->nodes
[level
+ 1];
309 pslot
= path
->slots
[level
+ 1];
312 * deal with the case where there is only one pointer in the root
313 * by promoting the node below to a root
316 struct buffer_head
*child
;
317 u64 blocknr
= mid_buf
->b_blocknr
;
319 if (btrfs_header_nritems(&mid
->header
) != 1)
322 /* promote the child to a root */
323 child
= read_node_slot(root
, mid_buf
, 0);
326 path
->nodes
[level
] = NULL
;
327 clean_tree_block(trans
, root
, mid_buf
);
328 wait_on_buffer(mid_buf
);
329 /* once for the path */
330 btrfs_block_release(root
, mid_buf
);
331 /* once for the root ptr */
332 btrfs_block_release(root
, mid_buf
);
333 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
335 parent
= btrfs_buffer_node(parent_buf
);
337 if (btrfs_header_nritems(&mid
->header
) >
338 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
341 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
342 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
344 /* first, try to make some room in the middle buffer */
346 btrfs_cow_block(trans
, root
, left_buf
, parent_buf
, pslot
- 1,
348 left
= btrfs_buffer_node(left_buf
);
349 orig_slot
+= btrfs_header_nritems(&left
->header
);
350 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
356 * then try to empty the right most buffer into the middle
359 btrfs_cow_block(trans
, root
, right_buf
, parent_buf
, pslot
+ 1,
361 right
= btrfs_buffer_node(right_buf
);
362 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
365 if (btrfs_header_nritems(&right
->header
) == 0) {
366 u64 blocknr
= right_buf
->b_blocknr
;
367 clean_tree_block(trans
, root
, right_buf
);
368 wait_on_buffer(right_buf
);
369 btrfs_block_release(root
, right_buf
);
372 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
376 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
380 btrfs_memcpy(root
, parent
,
381 &parent
->ptrs
[pslot
+ 1].key
,
383 sizeof(struct btrfs_disk_key
));
384 btrfs_mark_buffer_dirty(parent_buf
);
387 if (btrfs_header_nritems(&mid
->header
) == 1) {
389 * we're not allowed to leave a node with one item in the
390 * tree during a delete. A deletion from lower in the tree
391 * could try to delete the only pointer in this node.
392 * So, pull some keys from the left.
393 * There has to be a left pointer at this point because
394 * otherwise we would have pulled some pointers from the
398 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
403 if (btrfs_header_nritems(&mid
->header
) == 0) {
404 /* we've managed to empty the middle node, drop it */
405 u64 blocknr
= mid_buf
->b_blocknr
;
406 clean_tree_block(trans
, root
, mid_buf
);
407 wait_on_buffer(mid_buf
);
408 btrfs_block_release(root
, mid_buf
);
411 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
414 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
418 /* update the parent key to reflect our changes */
419 btrfs_memcpy(root
, parent
,
420 &parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
421 sizeof(struct btrfs_disk_key
));
422 btrfs_mark_buffer_dirty(parent_buf
);
425 /* update the path */
427 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
429 path
->nodes
[level
] = left_buf
;
430 path
->slots
[level
+ 1] -= 1;
431 path
->slots
[level
] = orig_slot
;
433 btrfs_block_release(root
, mid_buf
);
435 orig_slot
-= btrfs_header_nritems(&left
->header
);
436 path
->slots
[level
] = orig_slot
;
439 /* double check we haven't messed things up */
440 check_block(root
, path
, level
);
442 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[level
]),
447 btrfs_block_release(root
, right_buf
);
449 btrfs_block_release(root
, left_buf
);
454 * look for key in the tree. path is filled in with nodes along the way
455 * if key is found, we return zero and you can find the item in the leaf
456 * level of the path (level 0)
458 * If the key isn't found, the path points to the slot where it should
459 * be inserted, and 1 is returned. If there are other errors during the
460 * search a negative error number is returned.
462 * if ins_len > 0, nodes and leaves will be split as we walk down the
463 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
466 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
467 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
470 struct buffer_head
*b
;
471 struct buffer_head
*cow_buf
;
472 struct btrfs_node
*c
;
477 WARN_ON(p
->nodes
[0] != NULL
);
478 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
483 c
= btrfs_buffer_node(b
);
484 level
= btrfs_header_level(&c
->header
);
487 wret
= btrfs_cow_block(trans
, root
, b
,
492 c
= btrfs_buffer_node(b
);
494 BUG_ON(!cow
&& ins_len
);
495 if (level
!= btrfs_header_level(&c
->header
))
497 level
= btrfs_header_level(&c
->header
);
499 ret
= check_block(root
, p
, level
);
502 ret
= bin_search(c
, key
, &slot
);
503 if (!btrfs_is_leaf(c
)) {
506 p
->slots
[level
] = slot
;
507 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) ==
508 BTRFS_NODEPTRS_PER_BLOCK(root
)) {
509 int sret
= split_node(trans
, root
, p
, level
);
514 c
= btrfs_buffer_node(b
);
515 slot
= p
->slots
[level
];
516 } else if (ins_len
< 0) {
517 int sret
= balance_level(trans
, root
, p
,
524 c
= btrfs_buffer_node(b
);
525 slot
= p
->slots
[level
];
526 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
528 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
530 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
531 p
->slots
[level
] = slot
;
532 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
533 sizeof(struct btrfs_item
) + ins_len
) {
534 int sret
= split_leaf(trans
, root
, p
, ins_len
);
546 * adjust the pointers going up the tree, starting at level
547 * making sure the right key of each node is points to 'key'.
548 * This is used after shifting pointers to the left, so it stops
549 * fixing up pointers when a given leaf/node is not in slot 0 of the
552 * If this fails to write a tree block, it returns -1, but continues
553 * fixing up the blocks in ram so the tree is consistent.
555 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
556 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
561 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
562 struct btrfs_node
*t
;
563 int tslot
= path
->slots
[i
];
566 t
= btrfs_buffer_node(path
->nodes
[i
]);
567 btrfs_memcpy(root
, t
, &t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
568 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
576 * try to push data from one node into the next node left in the
579 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
580 * error, and > 0 if there was no room in the left hand block.
582 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
583 *root
, struct buffer_head
*dst_buf
, struct
584 buffer_head
*src_buf
)
586 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
587 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
593 src_nritems
= btrfs_header_nritems(&src
->header
);
594 dst_nritems
= btrfs_header_nritems(&dst
->header
);
595 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
596 if (push_items
<= 0) {
600 if (src_nritems
< push_items
)
601 push_items
= src_nritems
;
603 btrfs_memcpy(root
, dst
, dst
->ptrs
+ dst_nritems
, src
->ptrs
,
604 push_items
* sizeof(struct btrfs_key_ptr
));
605 if (push_items
< src_nritems
) {
606 btrfs_memmove(root
, src
, src
->ptrs
, src
->ptrs
+ push_items
,
607 (src_nritems
- push_items
) *
608 sizeof(struct btrfs_key_ptr
));
610 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
611 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
612 btrfs_mark_buffer_dirty(src_buf
);
613 btrfs_mark_buffer_dirty(dst_buf
);
618 * try to push data from one node into the next node right in the
621 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
622 * error, and > 0 if there was no room in the right hand block.
624 * this will only push up to 1/2 the contents of the left node over
626 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
627 btrfs_root
*root
, struct buffer_head
*dst_buf
,
628 struct buffer_head
*src_buf
)
630 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
631 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
638 src_nritems
= btrfs_header_nritems(&src
->header
);
639 dst_nritems
= btrfs_header_nritems(&dst
->header
);
640 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
641 if (push_items
<= 0) {
645 max_push
= src_nritems
/ 2 + 1;
646 /* don't try to empty the node */
647 if (max_push
> src_nritems
)
649 if (max_push
< push_items
)
650 push_items
= max_push
;
652 btrfs_memmove(root
, dst
, dst
->ptrs
+ push_items
, dst
->ptrs
,
653 dst_nritems
* sizeof(struct btrfs_key_ptr
));
655 btrfs_memcpy(root
, dst
, dst
->ptrs
,
656 src
->ptrs
+ src_nritems
- push_items
,
657 push_items
* sizeof(struct btrfs_key_ptr
));
659 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
660 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
662 btrfs_mark_buffer_dirty(src_buf
);
663 btrfs_mark_buffer_dirty(dst_buf
);
668 * helper function to insert a new root level in the tree.
669 * A new node is allocated, and a single item is inserted to
670 * point to the existing root
672 * returns zero on success or < 0 on failure.
674 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
675 *root
, struct btrfs_path
*path
, int level
)
677 struct buffer_head
*t
;
678 struct btrfs_node
*lower
;
679 struct btrfs_node
*c
;
680 struct btrfs_disk_key
*lower_key
;
682 BUG_ON(path
->nodes
[level
]);
683 BUG_ON(path
->nodes
[level
-1] != root
->node
);
685 t
= btrfs_alloc_free_block(trans
, root
);
686 c
= btrfs_buffer_node(t
);
687 memset(c
, 0, root
->blocksize
);
688 btrfs_set_header_nritems(&c
->header
, 1);
689 btrfs_set_header_level(&c
->header
, level
);
690 btrfs_set_header_blocknr(&c
->header
, t
->b_blocknr
);
691 btrfs_set_header_generation(&c
->header
, trans
->transid
);
692 btrfs_set_header_parentid(&c
->header
,
693 btrfs_header_parentid(btrfs_buffer_header(root
->node
)));
694 lower
= btrfs_buffer_node(path
->nodes
[level
-1]);
695 if (btrfs_is_leaf(lower
))
696 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
698 lower_key
= &lower
->ptrs
[0].key
;
699 btrfs_memcpy(root
, c
, &c
->ptrs
[0].key
, lower_key
,
700 sizeof(struct btrfs_disk_key
));
701 btrfs_set_node_blockptr(c
, 0, path
->nodes
[level
- 1]->b_blocknr
);
703 btrfs_mark_buffer_dirty(t
);
705 /* the super has an extra ref to root->node */
706 btrfs_block_release(root
, root
->node
);
709 path
->nodes
[level
] = t
;
710 path
->slots
[level
] = 0;
715 * worker function to insert a single pointer in a node.
716 * the node should have enough room for the pointer already
718 * slot and level indicate where you want the key to go, and
719 * blocknr is the block the key points to.
721 * returns zero on success and < 0 on any error
723 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
724 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
725 *key
, u64 blocknr
, int slot
, int level
)
727 struct btrfs_node
*lower
;
730 BUG_ON(!path
->nodes
[level
]);
731 lower
= btrfs_buffer_node(path
->nodes
[level
]);
732 nritems
= btrfs_header_nritems(&lower
->header
);
735 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
737 if (slot
!= nritems
) {
738 btrfs_memmove(root
, lower
, lower
->ptrs
+ slot
+ 1,
740 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
742 btrfs_memcpy(root
, lower
, &lower
->ptrs
[slot
].key
,
743 key
, sizeof(struct btrfs_disk_key
));
744 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
745 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
746 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
751 * split the node at the specified level in path in two.
752 * The path is corrected to point to the appropriate node after the split
754 * Before splitting this tries to make some room in the node by pushing
755 * left and right, if either one works, it returns right away.
757 * returns 0 on success and < 0 on failure
759 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
760 *root
, struct btrfs_path
*path
, int level
)
762 struct buffer_head
*t
;
763 struct btrfs_node
*c
;
764 struct buffer_head
*split_buffer
;
765 struct btrfs_node
*split
;
771 t
= path
->nodes
[level
];
772 c
= btrfs_buffer_node(t
);
773 if (t
== root
->node
) {
774 /* trying to split the root, lets make a new one */
775 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
779 c_nritems
= btrfs_header_nritems(&c
->header
);
780 split_buffer
= btrfs_alloc_free_block(trans
, root
);
781 split
= btrfs_buffer_node(split_buffer
);
782 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
783 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
784 btrfs_set_header_blocknr(&split
->header
, split_buffer
->b_blocknr
);
785 btrfs_set_header_generation(&split
->header
, trans
->transid
);
786 btrfs_set_header_parentid(&split
->header
,
787 btrfs_header_parentid(btrfs_buffer_header(root
->node
)));
788 mid
= (c_nritems
+ 1) / 2;
789 btrfs_memcpy(root
, split
, split
->ptrs
, c
->ptrs
+ mid
,
790 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
791 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
792 btrfs_set_header_nritems(&c
->header
, mid
);
795 btrfs_mark_buffer_dirty(t
);
796 btrfs_mark_buffer_dirty(split_buffer
);
797 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
798 split_buffer
->b_blocknr
, path
->slots
[level
+ 1] + 1,
803 if (path
->slots
[level
] >= mid
) {
804 path
->slots
[level
] -= mid
;
805 btrfs_block_release(root
, t
);
806 path
->nodes
[level
] = split_buffer
;
807 path
->slots
[level
+ 1] += 1;
809 btrfs_block_release(root
, split_buffer
);
815 * how many bytes are required to store the items in a leaf. start
816 * and nr indicate which items in the leaf to check. This totals up the
817 * space used both by the item structs and the item data
819 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
822 int end
= start
+ nr
- 1;
826 data_len
= btrfs_item_end(l
->items
+ start
);
827 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
828 data_len
+= sizeof(struct btrfs_item
) * nr
;
833 * push some data in the path leaf to the right, trying to free up at
834 * least data_size bytes. returns zero if the push worked, nonzero otherwise
836 * returns 1 if the push failed because the other node didn't have enough
837 * room, 0 if everything worked out and < 0 if there were major errors.
839 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
840 *root
, struct btrfs_path
*path
, int data_size
)
842 struct buffer_head
*left_buf
= path
->nodes
[0];
843 struct btrfs_leaf
*left
= btrfs_buffer_leaf(left_buf
);
844 struct btrfs_leaf
*right
;
845 struct buffer_head
*right_buf
;
846 struct buffer_head
*upper
;
847 struct btrfs_node
*upper_node
;
853 struct btrfs_item
*item
;
857 slot
= path
->slots
[1];
858 if (!path
->nodes
[1]) {
861 upper
= path
->nodes
[1];
862 upper_node
= btrfs_buffer_node(upper
);
863 if (slot
>= btrfs_header_nritems(&upper_node
->header
) - 1) {
866 right_buf
= read_tree_block(root
,
867 btrfs_node_blockptr(btrfs_buffer_node(upper
), slot
+ 1));
868 right
= btrfs_buffer_leaf(right_buf
);
869 free_space
= btrfs_leaf_free_space(root
, right
);
870 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
871 btrfs_block_release(root
, right_buf
);
874 /* cow and double check */
875 btrfs_cow_block(trans
, root
, right_buf
, upper
, slot
+ 1, &right_buf
);
876 right
= btrfs_buffer_leaf(right_buf
);
877 free_space
= btrfs_leaf_free_space(root
, right
);
878 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
879 btrfs_block_release(root
, right_buf
);
883 left_nritems
= btrfs_header_nritems(&left
->header
);
884 for (i
= left_nritems
- 1; i
>= 0; i
--) {
885 item
= left
->items
+ i
;
886 if (path
->slots
[0] == i
)
887 push_space
+= data_size
+ sizeof(*item
);
888 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
892 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
894 if (push_items
== 0) {
895 btrfs_block_release(root
, right_buf
);
898 right_nritems
= btrfs_header_nritems(&right
->header
);
899 /* push left to right */
900 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
901 push_space
-= leaf_data_end(root
, left
);
902 /* make room in the right data area */
903 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
904 leaf_data_end(root
, right
) - push_space
,
905 btrfs_leaf_data(right
) +
906 leaf_data_end(root
, right
), BTRFS_LEAF_DATA_SIZE(root
) -
907 leaf_data_end(root
, right
));
908 /* copy from the left data area */
909 btrfs_memcpy(root
, right
, btrfs_leaf_data(right
) +
910 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
911 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
913 btrfs_memmove(root
, right
, right
->items
+ push_items
, right
->items
,
914 right_nritems
* sizeof(struct btrfs_item
));
915 /* copy the items from left to right */
916 btrfs_memcpy(root
, right
, right
->items
, left
->items
+
917 left_nritems
- push_items
,
918 push_items
* sizeof(struct btrfs_item
));
920 /* update the item pointers */
921 right_nritems
+= push_items
;
922 btrfs_set_header_nritems(&right
->header
, right_nritems
);
923 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
924 for (i
= 0; i
< right_nritems
; i
++) {
925 btrfs_set_item_offset(right
->items
+ i
, push_space
-
926 btrfs_item_size(right
->items
+ i
));
927 push_space
= btrfs_item_offset(right
->items
+ i
);
929 left_nritems
-= push_items
;
930 btrfs_set_header_nritems(&left
->header
, left_nritems
);
932 btrfs_mark_buffer_dirty(left_buf
);
933 btrfs_mark_buffer_dirty(right_buf
);
934 btrfs_memcpy(root
, upper_node
, &upper_node
->ptrs
[slot
+ 1].key
,
935 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
936 btrfs_mark_buffer_dirty(upper
);
938 /* then fixup the leaf pointer in the path */
939 if (path
->slots
[0] >= left_nritems
) {
940 path
->slots
[0] -= left_nritems
;
941 btrfs_block_release(root
, path
->nodes
[0]);
942 path
->nodes
[0] = right_buf
;
945 btrfs_block_release(root
, right_buf
);
950 * push some data in the path leaf to the left, trying to free up at
951 * least data_size bytes. returns zero if the push worked, nonzero otherwise
953 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
954 *root
, struct btrfs_path
*path
, int data_size
)
956 struct buffer_head
*right_buf
= path
->nodes
[0];
957 struct btrfs_leaf
*right
= btrfs_buffer_leaf(right_buf
);
958 struct buffer_head
*t
;
959 struct btrfs_leaf
*left
;
965 struct btrfs_item
*item
;
966 u32 old_left_nritems
;
970 slot
= path
->slots
[1];
974 if (!path
->nodes
[1]) {
977 t
= read_tree_block(root
,
978 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[1]), slot
- 1));
979 left
= btrfs_buffer_leaf(t
);
980 free_space
= btrfs_leaf_free_space(root
, left
);
981 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
982 btrfs_block_release(root
, t
);
986 /* cow and double check */
987 btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
988 left
= btrfs_buffer_leaf(t
);
989 free_space
= btrfs_leaf_free_space(root
, left
);
990 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
991 btrfs_block_release(root
, t
);
995 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
996 item
= right
->items
+ i
;
997 if (path
->slots
[0] == i
)
998 push_space
+= data_size
+ sizeof(*item
);
999 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1003 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1005 if (push_items
== 0) {
1006 btrfs_block_release(root
, t
);
1009 /* push data from right to left */
1010 btrfs_memcpy(root
, left
, left
->items
+
1011 btrfs_header_nritems(&left
->header
),
1012 right
->items
, push_items
* sizeof(struct btrfs_item
));
1013 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1014 btrfs_item_offset(right
->items
+ push_items
-1);
1015 btrfs_memcpy(root
, left
, btrfs_leaf_data(left
) +
1016 leaf_data_end(root
, left
) - push_space
,
1017 btrfs_leaf_data(right
) +
1018 btrfs_item_offset(right
->items
+ push_items
- 1),
1020 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1021 BUG_ON(old_left_nritems
< 0);
1023 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1024 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1025 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1026 (BTRFS_LEAF_DATA_SIZE(root
) -
1027 btrfs_item_offset(left
->items
+
1028 old_left_nritems
- 1)));
1030 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1032 /* fixup right node */
1033 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1034 leaf_data_end(root
, right
);
1035 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1036 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1037 btrfs_leaf_data(right
) +
1038 leaf_data_end(root
, right
), push_space
);
1039 btrfs_memmove(root
, right
, right
->items
, right
->items
+ push_items
,
1040 (btrfs_header_nritems(&right
->header
) - push_items
) *
1041 sizeof(struct btrfs_item
));
1042 btrfs_set_header_nritems(&right
->header
,
1043 btrfs_header_nritems(&right
->header
) -
1045 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1047 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1048 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1049 btrfs_item_size(right
->items
+ i
));
1050 push_space
= btrfs_item_offset(right
->items
+ i
);
1053 btrfs_mark_buffer_dirty(t
);
1054 btrfs_mark_buffer_dirty(right_buf
);
1056 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1060 /* then fixup the leaf pointer in the path */
1061 if (path
->slots
[0] < push_items
) {
1062 path
->slots
[0] += old_left_nritems
;
1063 btrfs_block_release(root
, path
->nodes
[0]);
1065 path
->slots
[1] -= 1;
1067 btrfs_block_release(root
, t
);
1068 path
->slots
[0] -= push_items
;
1070 BUG_ON(path
->slots
[0] < 0);
1075 * split the path's leaf in two, making sure there is at least data_size
1076 * available for the resulting leaf level of the path.
1078 * returns 0 if all went well and < 0 on failure.
1080 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1081 *root
, struct btrfs_path
*path
, int data_size
)
1083 struct buffer_head
*l_buf
;
1084 struct btrfs_leaf
*l
;
1088 struct btrfs_leaf
*right
;
1089 struct buffer_head
*right_buffer
;
1090 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1097 /* first try to make some room by pushing left and right */
1098 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1102 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1106 l_buf
= path
->nodes
[0];
1107 l
= btrfs_buffer_leaf(l_buf
);
1109 /* did the pushes work? */
1110 if (btrfs_leaf_free_space(root
, l
) >=
1111 sizeof(struct btrfs_item
) + data_size
)
1114 if (!path
->nodes
[1]) {
1115 ret
= insert_new_root(trans
, root
, path
, 1);
1119 slot
= path
->slots
[0];
1120 nritems
= btrfs_header_nritems(&l
->header
);
1121 mid
= (nritems
+ 1)/ 2;
1122 right_buffer
= btrfs_alloc_free_block(trans
, root
);
1123 BUG_ON(!right_buffer
);
1124 BUG_ON(mid
== nritems
);
1125 right
= btrfs_buffer_leaf(right_buffer
);
1126 memset(&right
->header
, 0, sizeof(right
->header
));
1128 /* FIXME, just alloc a new leaf here */
1129 if (leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1130 BTRFS_LEAF_DATA_SIZE(root
))
1133 /* FIXME, just alloc a new leaf here */
1134 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1135 BTRFS_LEAF_DATA_SIZE(root
))
1138 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1139 btrfs_set_header_blocknr(&right
->header
, right_buffer
->b_blocknr
);
1140 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1141 btrfs_set_header_level(&right
->header
, 0);
1142 btrfs_set_header_parentid(&right
->header
,
1143 btrfs_header_parentid(btrfs_buffer_header(root
->node
)));
1144 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1145 leaf_data_end(root
, l
);
1146 btrfs_memcpy(root
, right
, right
->items
, l
->items
+ mid
,
1147 (nritems
- mid
) * sizeof(struct btrfs_item
));
1148 btrfs_memcpy(root
, right
,
1149 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1150 data_copy_size
, btrfs_leaf_data(l
) +
1151 leaf_data_end(root
, l
), data_copy_size
);
1152 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1153 btrfs_item_end(l
->items
+ mid
);
1155 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1156 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1157 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1160 btrfs_set_header_nritems(&l
->header
, mid
);
1162 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1163 right_buffer
->b_blocknr
, path
->slots
[1] + 1, 1);
1166 btrfs_mark_buffer_dirty(right_buffer
);
1167 btrfs_mark_buffer_dirty(l_buf
);
1168 BUG_ON(path
->slots
[0] != slot
);
1170 btrfs_block_release(root
, path
->nodes
[0]);
1171 path
->nodes
[0] = right_buffer
;
1172 path
->slots
[0] -= mid
;
1173 path
->slots
[1] += 1;
1175 btrfs_block_release(root
, right_buffer
);
1176 BUG_ON(path
->slots
[0] < 0);
1181 * Given a key and some data, insert an item into the tree.
1182 * This does all the path init required, making room in the tree if needed.
1184 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1185 *root
, struct btrfs_path
*path
, struct btrfs_key
1186 *cpu_key
, u32 data_size
)
1191 struct btrfs_leaf
*leaf
;
1192 struct buffer_head
*leaf_buf
;
1194 unsigned int data_end
;
1195 struct btrfs_disk_key disk_key
;
1197 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1199 /* create a root if there isn't one */
1202 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1209 slot_orig
= path
->slots
[0];
1210 leaf_buf
= path
->nodes
[0];
1211 leaf
= btrfs_buffer_leaf(leaf_buf
);
1213 nritems
= btrfs_header_nritems(&leaf
->header
);
1214 data_end
= leaf_data_end(root
, leaf
);
1216 if (btrfs_leaf_free_space(root
, leaf
) <
1217 sizeof(struct btrfs_item
) + data_size
)
1220 slot
= path
->slots
[0];
1222 if (slot
!= nritems
) {
1224 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1227 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1229 /* first correct the data pointers */
1230 for (i
= slot
; i
< nritems
; i
++) {
1231 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1232 btrfs_set_item_offset(leaf
->items
+ i
,
1236 /* shift the items */
1237 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
+ 1,
1239 (nritems
- slot
) * sizeof(struct btrfs_item
));
1241 /* shift the data */
1242 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1243 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1244 data_end
, old_data
- data_end
);
1245 data_end
= old_data
;
1247 /* setup the item for the new data */
1248 btrfs_memcpy(root
, leaf
, &leaf
->items
[slot
].key
, &disk_key
,
1249 sizeof(struct btrfs_disk_key
));
1250 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1251 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1252 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1253 btrfs_mark_buffer_dirty(leaf_buf
);
1257 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1259 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1261 check_leaf(root
, path
, 0);
1267 * Given a key and some data, insert an item into the tree.
1268 * This does all the path init required, making room in the tree if needed.
1270 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1271 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1275 struct btrfs_path
*path
;
1278 path
= btrfs_alloc_path();
1280 btrfs_init_path(path
);
1281 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
1283 ptr
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]),
1284 path
->slots
[0], u8
);
1285 btrfs_memcpy(root
, path
->nodes
[0]->b_data
,
1286 ptr
, data
, data_size
);
1287 btrfs_mark_buffer_dirty(path
->nodes
[0]);
1289 btrfs_release_path(root
, path
);
1290 btrfs_free_path(path
);
1295 * delete the pointer from a given node.
1297 * If the delete empties a node, the node is removed from the tree,
1298 * continuing all the way the root if required. The root is converted into
1299 * a leaf if all the nodes are emptied.
1301 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1302 struct btrfs_path
*path
, int level
, int slot
)
1304 struct btrfs_node
*node
;
1305 struct buffer_head
*parent
= path
->nodes
[level
];
1310 node
= btrfs_buffer_node(parent
);
1311 nritems
= btrfs_header_nritems(&node
->header
);
1312 if (slot
!= nritems
-1) {
1313 btrfs_memmove(root
, node
, node
->ptrs
+ slot
,
1314 node
->ptrs
+ slot
+ 1,
1315 sizeof(struct btrfs_key_ptr
) *
1316 (nritems
- slot
- 1));
1319 btrfs_set_header_nritems(&node
->header
, nritems
);
1320 if (nritems
== 0 && parent
== root
->node
) {
1321 struct btrfs_header
*header
= btrfs_buffer_header(root
->node
);
1322 BUG_ON(btrfs_header_level(header
) != 1);
1323 /* just turn the root into a leaf and break */
1324 btrfs_set_header_level(header
, 0);
1325 } else if (slot
== 0) {
1326 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1331 btrfs_mark_buffer_dirty(parent
);
1336 * delete the item at the leaf level in path. If that empties
1337 * the leaf, remove it from the tree
1339 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1340 struct btrfs_path
*path
)
1343 struct btrfs_leaf
*leaf
;
1344 struct buffer_head
*leaf_buf
;
1351 leaf_buf
= path
->nodes
[0];
1352 leaf
= btrfs_buffer_leaf(leaf_buf
);
1353 slot
= path
->slots
[0];
1354 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1355 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1356 nritems
= btrfs_header_nritems(&leaf
->header
);
1358 if (slot
!= nritems
- 1) {
1360 int data_end
= leaf_data_end(root
, leaf
);
1361 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1363 btrfs_leaf_data(leaf
) + data_end
,
1365 for (i
= slot
+ 1; i
< nritems
; i
++) {
1366 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1367 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1369 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
,
1370 leaf
->items
+ slot
+ 1,
1371 sizeof(struct btrfs_item
) *
1372 (nritems
- slot
- 1));
1374 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1376 /* delete the leaf if we've emptied it */
1378 if (leaf_buf
== root
->node
) {
1379 btrfs_set_header_level(&leaf
->header
, 0);
1381 clean_tree_block(trans
, root
, leaf_buf
);
1382 wait_on_buffer(leaf_buf
);
1383 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1386 wret
= btrfs_free_extent(trans
, root
,
1387 leaf_buf
->b_blocknr
, 1, 1);
1392 int used
= leaf_space_used(leaf
, 0, nritems
);
1394 wret
= fixup_low_keys(trans
, root
, path
,
1395 &leaf
->items
[0].key
, 1);
1400 /* delete the leaf if it is mostly empty */
1401 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1402 /* push_leaf_left fixes the path.
1403 * make sure the path still points to our leaf
1404 * for possible call to del_ptr below
1406 slot
= path
->slots
[1];
1408 wret
= push_leaf_left(trans
, root
, path
, 1);
1411 if (path
->nodes
[0] == leaf_buf
&&
1412 btrfs_header_nritems(&leaf
->header
)) {
1413 wret
= push_leaf_right(trans
, root
, path
, 1);
1417 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1418 u64 blocknr
= leaf_buf
->b_blocknr
;
1419 clean_tree_block(trans
, root
, leaf_buf
);
1420 wait_on_buffer(leaf_buf
);
1421 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1424 btrfs_block_release(root
, leaf_buf
);
1425 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1430 btrfs_mark_buffer_dirty(leaf_buf
);
1431 btrfs_block_release(root
, leaf_buf
);
1434 btrfs_mark_buffer_dirty(leaf_buf
);
1441 * walk up the tree as far as required to find the next leaf.
1442 * returns 0 if it found something or 1 if there are no greater leaves.
1443 * returns < 0 on io errors.
1445 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1450 struct buffer_head
*c
;
1451 struct btrfs_node
*c_node
;
1452 struct buffer_head
*next
= NULL
;
1454 while(level
< BTRFS_MAX_LEVEL
) {
1455 if (!path
->nodes
[level
])
1457 slot
= path
->slots
[level
] + 1;
1458 c
= path
->nodes
[level
];
1459 c_node
= btrfs_buffer_node(c
);
1460 if (slot
>= btrfs_header_nritems(&c_node
->header
)) {
1464 blocknr
= btrfs_node_blockptr(c_node
, slot
);
1466 btrfs_block_release(root
, next
);
1467 next
= read_tree_block(root
, blocknr
);
1470 path
->slots
[level
] = slot
;
1473 c
= path
->nodes
[level
];
1474 btrfs_block_release(root
, c
);
1475 path
->nodes
[level
] = next
;
1476 path
->slots
[level
] = 0;
1479 next
= read_tree_block(root
,
1480 btrfs_node_blockptr(btrfs_buffer_node(next
), 0));
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