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_key
*ins_key
,
10 struct btrfs_path
*path
, int data_size
);
11 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
12 *root
, struct buffer_head
*dst
, struct buffer_head
14 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
15 btrfs_root
*root
, struct buffer_head
*dst_buf
,
16 struct buffer_head
*src_buf
);
17 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
18 struct btrfs_path
*path
, int level
, int slot
);
20 inline void btrfs_init_path(struct btrfs_path
*p
)
22 memset(p
, 0, sizeof(*p
));
25 struct btrfs_path
*btrfs_alloc_path(void)
27 struct btrfs_path
*path
;
28 path
= kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
30 btrfs_init_path(path
);
34 void btrfs_free_path(struct btrfs_path
*p
)
36 btrfs_release_path(NULL
, p
);
37 kmem_cache_free(btrfs_path_cachep
, p
);
40 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
43 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
46 btrfs_block_release(root
, p
->nodes
[i
]);
48 memset(p
, 0, sizeof(*p
));
51 static int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
52 *root
, struct buffer_head
*buf
, struct buffer_head
53 *parent
, int parent_slot
, struct buffer_head
56 struct buffer_head
*cow
;
57 struct btrfs_node
*cow_node
;
59 if (btrfs_header_generation(btrfs_buffer_header(buf
)) ==
64 cow
= btrfs_alloc_free_block(trans
, root
, buf
->b_blocknr
);
65 cow_node
= btrfs_buffer_node(cow
);
66 if (buf
->b_size
!= root
->blocksize
|| cow
->b_size
!= root
->blocksize
)
68 memcpy(cow_node
, btrfs_buffer_node(buf
), root
->blocksize
);
69 btrfs_set_header_blocknr(&cow_node
->header
, bh_blocknr(cow
));
70 btrfs_set_header_generation(&cow_node
->header
, trans
->transid
);
71 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
, bh_blocknr(buf
), 1, 1);
79 btrfs_block_release(root
, buf
);
81 btrfs_set_node_blockptr(btrfs_buffer_node(parent
), parent_slot
,
83 btrfs_mark_buffer_dirty(parent
);
84 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
86 btrfs_block_release(root
, buf
);
87 mark_buffer_dirty(cow
);
93 * The leaf data grows from end-to-front in the node.
94 * this returns the address of the start of the last item,
95 * which is the stop of the leaf data stack
97 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
98 struct btrfs_leaf
*leaf
)
100 u32 nr
= btrfs_header_nritems(&leaf
->header
);
102 return BTRFS_LEAF_DATA_SIZE(root
);
103 return btrfs_item_offset(leaf
->items
+ nr
- 1);
107 * compare two keys in a memcmp fashion
109 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
113 btrfs_disk_key_to_cpu(&k1
, disk
);
115 if (k1
.objectid
> k2
->objectid
)
117 if (k1
.objectid
< k2
->objectid
)
119 if (k1
.flags
> k2
->flags
)
121 if (k1
.flags
< k2
->flags
)
123 if (k1
.offset
> k2
->offset
)
125 if (k1
.offset
< k2
->offset
)
130 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
134 struct btrfs_node
*parent
= NULL
;
135 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
137 u32 nritems
= btrfs_header_nritems(&node
->header
);
139 if (path
->nodes
[level
+ 1])
140 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
141 parent_slot
= path
->slots
[level
+ 1];
142 BUG_ON(nritems
== 0);
144 struct btrfs_disk_key
*parent_key
;
145 parent_key
= &parent
->ptrs
[parent_slot
].key
;
146 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
147 sizeof(struct btrfs_disk_key
)));
148 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
149 btrfs_header_blocknr(&node
->header
));
151 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
152 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
153 struct btrfs_key cpukey
;
154 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[i
+ 1].key
);
155 BUG_ON(comp_keys(&node
->ptrs
[i
].key
, &cpukey
) >= 0);
160 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
164 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[level
]);
165 struct btrfs_node
*parent
= NULL
;
167 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
169 if (path
->nodes
[level
+ 1])
170 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
171 parent_slot
= path
->slots
[level
+ 1];
172 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
178 struct btrfs_disk_key
*parent_key
;
179 parent_key
= &parent
->ptrs
[parent_slot
].key
;
180 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
181 sizeof(struct btrfs_disk_key
)));
182 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
183 btrfs_header_blocknr(&leaf
->header
));
185 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
186 struct btrfs_key cpukey
;
187 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[i
+ 1].key
);
188 BUG_ON(comp_keys(&leaf
->items
[i
].key
,
190 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) !=
191 btrfs_item_end(leaf
->items
+ i
+ 1));
193 BUG_ON(btrfs_item_offset(leaf
->items
+ i
) +
194 btrfs_item_size(leaf
->items
+ i
) !=
195 BTRFS_LEAF_DATA_SIZE(root
));
201 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
204 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
205 if (memcmp(node
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
206 sizeof(node
->header
.fsid
)))
209 return check_leaf(root
, path
, level
);
210 return check_node(root
, path
, level
);
214 * search for key in the array p. items p are item_size apart
215 * and there are 'max' items in p
216 * the slot in the array is returned via slot, and it points to
217 * the place where you would insert key if it is not found in
220 * slot may point to max if the key is bigger than all of the keys
222 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
229 struct btrfs_disk_key
*tmp
;
232 mid
= (low
+ high
) / 2;
233 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
234 ret
= comp_keys(tmp
, key
);
250 * simple bin_search frontend that does the right thing for
253 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
255 if (btrfs_is_leaf(c
)) {
256 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
257 return generic_bin_search((void *)l
->items
,
258 sizeof(struct btrfs_item
),
259 key
, btrfs_header_nritems(&c
->header
),
262 return generic_bin_search((void *)c
->ptrs
,
263 sizeof(struct btrfs_key_ptr
),
264 key
, btrfs_header_nritems(&c
->header
),
270 static struct buffer_head
*read_node_slot(struct btrfs_root
*root
,
271 struct buffer_head
*parent_buf
,
274 struct btrfs_node
*node
= btrfs_buffer_node(parent_buf
);
277 if (slot
>= btrfs_header_nritems(&node
->header
))
279 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
282 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
283 *root
, struct btrfs_path
*path
, int level
)
285 struct buffer_head
*right_buf
;
286 struct buffer_head
*mid_buf
;
287 struct buffer_head
*left_buf
;
288 struct buffer_head
*parent_buf
= NULL
;
289 struct btrfs_node
*right
= NULL
;
290 struct btrfs_node
*mid
;
291 struct btrfs_node
*left
= NULL
;
292 struct btrfs_node
*parent
= NULL
;
296 int orig_slot
= path
->slots
[level
];
302 mid_buf
= path
->nodes
[level
];
303 mid
= btrfs_buffer_node(mid_buf
);
304 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
306 if (level
< BTRFS_MAX_LEVEL
- 1)
307 parent_buf
= path
->nodes
[level
+ 1];
308 pslot
= path
->slots
[level
+ 1];
311 * deal with the case where there is only one pointer in the root
312 * by promoting the node below to a root
315 struct buffer_head
*child
;
316 u64 blocknr
= bh_blocknr(mid_buf
);
318 if (btrfs_header_nritems(&mid
->header
) != 1)
321 /* promote the child to a root */
322 child
= read_node_slot(root
, mid_buf
, 0);
325 path
->nodes
[level
] = NULL
;
326 clean_tree_block(trans
, root
, mid_buf
);
327 wait_on_buffer(mid_buf
);
328 /* once for the path */
329 btrfs_block_release(root
, mid_buf
);
330 /* once for the root ptr */
331 btrfs_block_release(root
, mid_buf
);
332 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
334 parent
= btrfs_buffer_node(parent_buf
);
336 if (btrfs_header_nritems(&mid
->header
) >
337 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
340 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
341 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
343 /* first, try to make some room in the middle buffer */
345 btrfs_cow_block(trans
, root
, left_buf
, parent_buf
, pslot
- 1,
347 left
= btrfs_buffer_node(left_buf
);
348 orig_slot
+= btrfs_header_nritems(&left
->header
);
349 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
355 * then try to empty the right most buffer into the middle
358 btrfs_cow_block(trans
, root
, right_buf
, parent_buf
, pslot
+ 1,
360 right
= btrfs_buffer_node(right_buf
);
361 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
364 if (btrfs_header_nritems(&right
->header
) == 0) {
365 u64 blocknr
= bh_blocknr(right_buf
);
366 clean_tree_block(trans
, root
, right_buf
);
367 wait_on_buffer(right_buf
);
368 btrfs_block_release(root
, right_buf
);
371 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
375 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
379 btrfs_memcpy(root
, parent
,
380 &parent
->ptrs
[pslot
+ 1].key
,
382 sizeof(struct btrfs_disk_key
));
383 btrfs_mark_buffer_dirty(parent_buf
);
386 if (btrfs_header_nritems(&mid
->header
) == 1) {
388 * we're not allowed to leave a node with one item in the
389 * tree during a delete. A deletion from lower in the tree
390 * could try to delete the only pointer in this node.
391 * So, pull some keys from the left.
392 * There has to be a left pointer at this point because
393 * otherwise we would have pulled some pointers from the
397 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
402 if (btrfs_header_nritems(&mid
->header
) == 0) {
403 /* we've managed to empty the middle node, drop it */
404 u64 blocknr
= bh_blocknr(mid_buf
);
405 clean_tree_block(trans
, root
, mid_buf
);
406 wait_on_buffer(mid_buf
);
407 btrfs_block_release(root
, mid_buf
);
410 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
413 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
417 /* update the parent key to reflect our changes */
418 btrfs_memcpy(root
, parent
,
419 &parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
420 sizeof(struct btrfs_disk_key
));
421 btrfs_mark_buffer_dirty(parent_buf
);
424 /* update the path */
426 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
428 path
->nodes
[level
] = left_buf
;
429 path
->slots
[level
+ 1] -= 1;
430 path
->slots
[level
] = orig_slot
;
432 btrfs_block_release(root
, mid_buf
);
434 orig_slot
-= btrfs_header_nritems(&left
->header
);
435 path
->slots
[level
] = orig_slot
;
438 /* double check we haven't messed things up */
439 check_block(root
, path
, level
);
441 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[level
]),
446 btrfs_block_release(root
, right_buf
);
448 btrfs_block_release(root
, left_buf
);
452 /* returns zero if the push worked, non-zero otherwise */
453 static int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
454 struct btrfs_root
*root
,
455 struct btrfs_path
*path
, int level
)
457 struct buffer_head
*right_buf
;
458 struct buffer_head
*mid_buf
;
459 struct buffer_head
*left_buf
;
460 struct buffer_head
*parent_buf
= NULL
;
461 struct btrfs_node
*right
= NULL
;
462 struct btrfs_node
*mid
;
463 struct btrfs_node
*left
= NULL
;
464 struct btrfs_node
*parent
= NULL
;
468 int orig_slot
= path
->slots
[level
];
474 mid_buf
= path
->nodes
[level
];
475 mid
= btrfs_buffer_node(mid_buf
);
476 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
478 if (level
< BTRFS_MAX_LEVEL
- 1)
479 parent_buf
= path
->nodes
[level
+ 1];
480 pslot
= path
->slots
[level
+ 1];
484 parent
= btrfs_buffer_node(parent_buf
);
486 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
488 /* first, try to make some room in the middle buffer */
491 left
= btrfs_buffer_node(left_buf
);
492 left_nr
= btrfs_header_nritems(&left
->header
);
493 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
496 btrfs_cow_block(trans
, root
, left_buf
, parent_buf
,
497 pslot
- 1, &left_buf
);
498 left
= btrfs_buffer_node(left_buf
);
499 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
504 orig_slot
+= left_nr
;
505 btrfs_memcpy(root
, parent
,
506 &parent
->ptrs
[pslot
].key
,
508 sizeof(struct btrfs_disk_key
));
509 btrfs_mark_buffer_dirty(parent_buf
);
510 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
511 path
->nodes
[level
] = left_buf
;
512 path
->slots
[level
+ 1] -= 1;
513 path
->slots
[level
] = orig_slot
;
514 btrfs_block_release(root
, mid_buf
);
517 btrfs_header_nritems(&left
->header
);
518 path
->slots
[level
] = orig_slot
;
519 btrfs_block_release(root
, left_buf
);
521 check_node(root
, path
, level
);
524 btrfs_block_release(root
, left_buf
);
526 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
529 * then try to empty the right most buffer into the middle
533 right
= btrfs_buffer_node(right_buf
);
534 right_nr
= btrfs_header_nritems(&right
->header
);
535 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
538 btrfs_cow_block(trans
, root
, right_buf
,
539 parent_buf
, pslot
+ 1, &right_buf
);
540 right
= btrfs_buffer_node(right_buf
);
541 wret
= balance_node_right(trans
, root
,
547 btrfs_memcpy(root
, parent
,
548 &parent
->ptrs
[pslot
+ 1].key
,
550 sizeof(struct btrfs_disk_key
));
551 btrfs_mark_buffer_dirty(parent_buf
);
552 if (btrfs_header_nritems(&mid
->header
) <= orig_slot
) {
553 path
->nodes
[level
] = right_buf
;
554 path
->slots
[level
+ 1] += 1;
555 path
->slots
[level
] = orig_slot
-
556 btrfs_header_nritems(&mid
->header
);
557 btrfs_block_release(root
, mid_buf
);
559 btrfs_block_release(root
, right_buf
);
561 check_node(root
, path
, level
);
564 btrfs_block_release(root
, right_buf
);
566 check_node(root
, path
, level
);
571 * look for key in the tree. path is filled in with nodes along the way
572 * if key is found, we return zero and you can find the item in the leaf
573 * level of the path (level 0)
575 * If the key isn't found, the path points to the slot where it should
576 * be inserted, and 1 is returned. If there are other errors during the
577 * search a negative error number is returned.
579 * if ins_len > 0, nodes and leaves will be split as we walk down the
580 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
583 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
584 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
587 struct buffer_head
*b
;
588 struct buffer_head
*cow_buf
;
589 struct btrfs_node
*c
;
594 WARN_ON(p
->nodes
[0] != NULL
);
595 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
600 c
= btrfs_buffer_node(b
);
601 level
= btrfs_header_level(&c
->header
);
604 wret
= btrfs_cow_block(trans
, root
, b
,
609 c
= btrfs_buffer_node(b
);
611 BUG_ON(!cow
&& ins_len
);
612 if (level
!= btrfs_header_level(&c
->header
))
614 level
= btrfs_header_level(&c
->header
);
616 ret
= check_block(root
, p
, level
);
619 ret
= bin_search(c
, key
, &slot
);
620 if (!btrfs_is_leaf(c
)) {
623 p
->slots
[level
] = slot
;
624 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) >=
625 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
626 int sret
= split_node(trans
, root
, p
, level
);
631 c
= btrfs_buffer_node(b
);
632 slot
= p
->slots
[level
];
633 } else if (ins_len
< 0) {
634 int sret
= balance_level(trans
, root
, p
,
641 c
= btrfs_buffer_node(b
);
642 slot
= p
->slots
[level
];
643 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
645 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
647 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
648 p
->slots
[level
] = slot
;
649 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
650 sizeof(struct btrfs_item
) + ins_len
) {
651 int sret
= split_leaf(trans
, root
, key
,
664 * adjust the pointers going up the tree, starting at level
665 * making sure the right key of each node is points to 'key'.
666 * This is used after shifting pointers to the left, so it stops
667 * fixing up pointers when a given leaf/node is not in slot 0 of the
670 * If this fails to write a tree block, it returns -1, but continues
671 * fixing up the blocks in ram so the tree is consistent.
673 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
674 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
679 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
680 struct btrfs_node
*t
;
681 int tslot
= path
->slots
[i
];
684 t
= btrfs_buffer_node(path
->nodes
[i
]);
685 btrfs_memcpy(root
, t
, &t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
686 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
694 * try to push data from one node into the next node left in the
697 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
698 * error, and > 0 if there was no room in the left hand block.
700 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
701 *root
, struct buffer_head
*dst_buf
, struct
702 buffer_head
*src_buf
)
704 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
705 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
711 src_nritems
= btrfs_header_nritems(&src
->header
);
712 dst_nritems
= btrfs_header_nritems(&dst
->header
);
713 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
714 if (push_items
<= 0) {
718 if (src_nritems
< push_items
)
719 push_items
= src_nritems
;
721 btrfs_memcpy(root
, dst
, dst
->ptrs
+ dst_nritems
, src
->ptrs
,
722 push_items
* sizeof(struct btrfs_key_ptr
));
723 if (push_items
< src_nritems
) {
724 btrfs_memmove(root
, src
, src
->ptrs
, src
->ptrs
+ push_items
,
725 (src_nritems
- push_items
) *
726 sizeof(struct btrfs_key_ptr
));
728 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
729 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
730 btrfs_mark_buffer_dirty(src_buf
);
731 btrfs_mark_buffer_dirty(dst_buf
);
736 * try to push data from one node into the next node right in the
739 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
740 * error, and > 0 if there was no room in the right hand block.
742 * this will only push up to 1/2 the contents of the left node over
744 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
745 btrfs_root
*root
, struct buffer_head
*dst_buf
,
746 struct buffer_head
*src_buf
)
748 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
749 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
756 src_nritems
= btrfs_header_nritems(&src
->header
);
757 dst_nritems
= btrfs_header_nritems(&dst
->header
);
758 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
759 if (push_items
<= 0) {
763 max_push
= src_nritems
/ 2 + 1;
764 /* don't try to empty the node */
765 if (max_push
> src_nritems
)
767 if (max_push
< push_items
)
768 push_items
= max_push
;
770 btrfs_memmove(root
, dst
, dst
->ptrs
+ push_items
, dst
->ptrs
,
771 dst_nritems
* sizeof(struct btrfs_key_ptr
));
773 btrfs_memcpy(root
, dst
, dst
->ptrs
,
774 src
->ptrs
+ src_nritems
- push_items
,
775 push_items
* sizeof(struct btrfs_key_ptr
));
777 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
778 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
780 btrfs_mark_buffer_dirty(src_buf
);
781 btrfs_mark_buffer_dirty(dst_buf
);
786 * helper function to insert a new root level in the tree.
787 * A new node is allocated, and a single item is inserted to
788 * point to the existing root
790 * returns zero on success or < 0 on failure.
792 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
793 *root
, struct btrfs_path
*path
, int level
)
795 struct buffer_head
*t
;
796 struct btrfs_node
*lower
;
797 struct btrfs_node
*c
;
798 struct btrfs_disk_key
*lower_key
;
800 BUG_ON(path
->nodes
[level
]);
801 BUG_ON(path
->nodes
[level
-1] != root
->node
);
803 t
= btrfs_alloc_free_block(trans
, root
, root
->node
->b_blocknr
);
804 c
= btrfs_buffer_node(t
);
805 memset(c
, 0, root
->blocksize
);
806 btrfs_set_header_nritems(&c
->header
, 1);
807 btrfs_set_header_level(&c
->header
, level
);
808 btrfs_set_header_blocknr(&c
->header
, bh_blocknr(t
));
809 btrfs_set_header_generation(&c
->header
, trans
->transid
);
810 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
811 lower
= btrfs_buffer_node(path
->nodes
[level
-1]);
812 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
813 sizeof(c
->header
.fsid
));
814 if (btrfs_is_leaf(lower
))
815 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
817 lower_key
= &lower
->ptrs
[0].key
;
818 btrfs_memcpy(root
, c
, &c
->ptrs
[0].key
, lower_key
,
819 sizeof(struct btrfs_disk_key
));
820 btrfs_set_node_blockptr(c
, 0, bh_blocknr(path
->nodes
[level
- 1]));
822 btrfs_mark_buffer_dirty(t
);
824 /* the super has an extra ref to root->node */
825 btrfs_block_release(root
, root
->node
);
828 path
->nodes
[level
] = t
;
829 path
->slots
[level
] = 0;
834 * worker function to insert a single pointer in a node.
835 * the node should have enough room for the pointer already
837 * slot and level indicate where you want the key to go, and
838 * blocknr is the block the key points to.
840 * returns zero on success and < 0 on any error
842 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
843 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
844 *key
, u64 blocknr
, int slot
, int level
)
846 struct btrfs_node
*lower
;
849 BUG_ON(!path
->nodes
[level
]);
850 lower
= btrfs_buffer_node(path
->nodes
[level
]);
851 nritems
= btrfs_header_nritems(&lower
->header
);
854 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
856 if (slot
!= nritems
) {
857 btrfs_memmove(root
, lower
, lower
->ptrs
+ slot
+ 1,
859 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
861 btrfs_memcpy(root
, lower
, &lower
->ptrs
[slot
].key
,
862 key
, sizeof(struct btrfs_disk_key
));
863 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
864 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
865 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
870 * split the node at the specified level in path in two.
871 * The path is corrected to point to the appropriate node after the split
873 * Before splitting this tries to make some room in the node by pushing
874 * left and right, if either one works, it returns right away.
876 * returns 0 on success and < 0 on failure
878 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
879 *root
, struct btrfs_path
*path
, int level
)
881 struct buffer_head
*t
;
882 struct btrfs_node
*c
;
883 struct buffer_head
*split_buffer
;
884 struct btrfs_node
*split
;
890 t
= path
->nodes
[level
];
891 c
= btrfs_buffer_node(t
);
892 if (t
== root
->node
) {
893 /* trying to split the root, lets make a new one */
894 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
898 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
899 t
= path
->nodes
[level
];
900 c
= btrfs_buffer_node(t
);
902 btrfs_header_nritems(&c
->header
) <
903 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1)
907 c_nritems
= btrfs_header_nritems(&c
->header
);
908 split_buffer
= btrfs_alloc_free_block(trans
, root
, t
->b_blocknr
);
909 split
= btrfs_buffer_node(split_buffer
);
910 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
911 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
912 btrfs_set_header_blocknr(&split
->header
, bh_blocknr(split_buffer
));
913 btrfs_set_header_generation(&split
->header
, trans
->transid
);
914 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
915 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
916 sizeof(split
->header
.fsid
));
917 mid
= (c_nritems
+ 1) / 2;
918 btrfs_memcpy(root
, split
, split
->ptrs
, c
->ptrs
+ mid
,
919 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
920 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
921 btrfs_set_header_nritems(&c
->header
, mid
);
924 btrfs_mark_buffer_dirty(t
);
925 btrfs_mark_buffer_dirty(split_buffer
);
926 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
927 bh_blocknr(split_buffer
), path
->slots
[level
+ 1] + 1,
932 if (path
->slots
[level
] >= mid
) {
933 path
->slots
[level
] -= mid
;
934 btrfs_block_release(root
, t
);
935 path
->nodes
[level
] = split_buffer
;
936 path
->slots
[level
+ 1] += 1;
938 btrfs_block_release(root
, split_buffer
);
944 * how many bytes are required to store the items in a leaf. start
945 * and nr indicate which items in the leaf to check. This totals up the
946 * space used both by the item structs and the item data
948 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
951 int nritems
= btrfs_header_nritems(&l
->header
);
952 int end
= min(nritems
, start
+ nr
) - 1;
956 data_len
= btrfs_item_end(l
->items
+ start
);
957 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
958 data_len
+= sizeof(struct btrfs_item
) * nr
;
959 WARN_ON(data_len
< 0);
964 * The space between the end of the leaf items and
965 * the start of the leaf data. IOW, how much room
966 * the leaf has left for both items and data
968 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
970 int nritems
= btrfs_header_nritems(&leaf
->header
);
971 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
975 * push some data in the path leaf to the right, trying to free up at
976 * least data_size bytes. returns zero if the push worked, nonzero otherwise
978 * returns 1 if the push failed because the other node didn't have enough
979 * room, 0 if everything worked out and < 0 if there were major errors.
981 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
982 *root
, struct btrfs_path
*path
, int data_size
)
984 struct buffer_head
*left_buf
= path
->nodes
[0];
985 struct btrfs_leaf
*left
= btrfs_buffer_leaf(left_buf
);
986 struct btrfs_leaf
*right
;
987 struct buffer_head
*right_buf
;
988 struct buffer_head
*upper
;
989 struct btrfs_node
*upper_node
;
995 struct btrfs_item
*item
;
999 slot
= path
->slots
[1];
1000 if (!path
->nodes
[1]) {
1003 upper
= path
->nodes
[1];
1004 upper_node
= btrfs_buffer_node(upper
);
1005 if (slot
>= btrfs_header_nritems(&upper_node
->header
) - 1) {
1008 right_buf
= read_tree_block(root
,
1009 btrfs_node_blockptr(btrfs_buffer_node(upper
), slot
+ 1));
1010 right
= btrfs_buffer_leaf(right_buf
);
1011 free_space
= btrfs_leaf_free_space(root
, right
);
1012 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1013 btrfs_block_release(root
, right_buf
);
1016 /* cow and double check */
1017 btrfs_cow_block(trans
, root
, right_buf
, upper
, slot
+ 1, &right_buf
);
1018 right
= btrfs_buffer_leaf(right_buf
);
1019 free_space
= btrfs_leaf_free_space(root
, right
);
1020 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1021 btrfs_block_release(root
, right_buf
);
1025 left_nritems
= btrfs_header_nritems(&left
->header
);
1026 if (left_nritems
== 0) {
1027 btrfs_block_release(root
, right_buf
);
1030 for (i
= left_nritems
- 1; i
>= 1; i
--) {
1031 item
= left
->items
+ i
;
1032 if (path
->slots
[0] == i
)
1033 push_space
+= data_size
+ sizeof(*item
);
1034 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1038 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1040 if (push_items
== 0) {
1041 btrfs_block_release(root
, right_buf
);
1044 if (push_items
== left_nritems
)
1046 right_nritems
= btrfs_header_nritems(&right
->header
);
1047 /* push left to right */
1048 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
1049 push_space
-= leaf_data_end(root
, left
);
1050 /* make room in the right data area */
1051 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1052 leaf_data_end(root
, right
) - push_space
,
1053 btrfs_leaf_data(right
) +
1054 leaf_data_end(root
, right
), BTRFS_LEAF_DATA_SIZE(root
) -
1055 leaf_data_end(root
, right
));
1056 /* copy from the left data area */
1057 btrfs_memcpy(root
, right
, btrfs_leaf_data(right
) +
1058 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1059 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1061 btrfs_memmove(root
, right
, right
->items
+ push_items
, right
->items
,
1062 right_nritems
* sizeof(struct btrfs_item
));
1063 /* copy the items from left to right */
1064 btrfs_memcpy(root
, right
, right
->items
, left
->items
+
1065 left_nritems
- push_items
,
1066 push_items
* sizeof(struct btrfs_item
));
1068 /* update the item pointers */
1069 right_nritems
+= push_items
;
1070 btrfs_set_header_nritems(&right
->header
, right_nritems
);
1071 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1072 for (i
= 0; i
< right_nritems
; i
++) {
1073 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1074 btrfs_item_size(right
->items
+ i
));
1075 push_space
= btrfs_item_offset(right
->items
+ i
);
1077 left_nritems
-= push_items
;
1078 btrfs_set_header_nritems(&left
->header
, left_nritems
);
1080 btrfs_mark_buffer_dirty(left_buf
);
1081 btrfs_mark_buffer_dirty(right_buf
);
1083 btrfs_memcpy(root
, upper_node
, &upper_node
->ptrs
[slot
+ 1].key
,
1084 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
1085 btrfs_mark_buffer_dirty(upper
);
1087 /* then fixup the leaf pointer in the path */
1088 if (path
->slots
[0] >= left_nritems
) {
1089 path
->slots
[0] -= left_nritems
;
1090 btrfs_block_release(root
, path
->nodes
[0]);
1091 path
->nodes
[0] = right_buf
;
1092 path
->slots
[1] += 1;
1094 btrfs_block_release(root
, right_buf
);
1099 * push some data in the path leaf to the left, trying to free up at
1100 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1102 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1103 *root
, struct btrfs_path
*path
, int data_size
)
1105 struct buffer_head
*right_buf
= path
->nodes
[0];
1106 struct btrfs_leaf
*right
= btrfs_buffer_leaf(right_buf
);
1107 struct buffer_head
*t
;
1108 struct btrfs_leaf
*left
;
1114 struct btrfs_item
*item
;
1115 u32 old_left_nritems
;
1119 slot
= path
->slots
[1];
1123 if (!path
->nodes
[1]) {
1126 t
= read_tree_block(root
,
1127 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[1]), slot
- 1));
1128 left
= btrfs_buffer_leaf(t
);
1129 free_space
= btrfs_leaf_free_space(root
, left
);
1130 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1131 btrfs_block_release(root
, t
);
1135 /* cow and double check */
1136 btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
1137 left
= btrfs_buffer_leaf(t
);
1138 free_space
= btrfs_leaf_free_space(root
, left
);
1139 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1140 btrfs_block_release(root
, t
);
1144 if (btrfs_header_nritems(&right
->header
) == 0) {
1145 btrfs_block_release(root
, t
);
1149 for (i
= 0; i
< btrfs_header_nritems(&right
->header
) - 1; i
++) {
1150 item
= right
->items
+ i
;
1151 if (path
->slots
[0] == i
)
1152 push_space
+= data_size
+ sizeof(*item
);
1153 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1157 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1159 if (push_items
== 0) {
1160 btrfs_block_release(root
, t
);
1163 if (push_items
== btrfs_header_nritems(&right
->header
))
1165 /* push data from right to left */
1166 btrfs_memcpy(root
, left
, left
->items
+
1167 btrfs_header_nritems(&left
->header
),
1168 right
->items
, push_items
* sizeof(struct btrfs_item
));
1169 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1170 btrfs_item_offset(right
->items
+ push_items
-1);
1171 btrfs_memcpy(root
, left
, btrfs_leaf_data(left
) +
1172 leaf_data_end(root
, left
) - push_space
,
1173 btrfs_leaf_data(right
) +
1174 btrfs_item_offset(right
->items
+ push_items
- 1),
1176 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1177 BUG_ON(old_left_nritems
< 0);
1179 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1180 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1181 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1182 (BTRFS_LEAF_DATA_SIZE(root
) -
1183 btrfs_item_offset(left
->items
+
1184 old_left_nritems
- 1)));
1186 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1188 /* fixup right node */
1189 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1190 leaf_data_end(root
, right
);
1191 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1192 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1193 btrfs_leaf_data(right
) +
1194 leaf_data_end(root
, right
), push_space
);
1195 btrfs_memmove(root
, right
, right
->items
, right
->items
+ push_items
,
1196 (btrfs_header_nritems(&right
->header
) - push_items
) *
1197 sizeof(struct btrfs_item
));
1198 btrfs_set_header_nritems(&right
->header
,
1199 btrfs_header_nritems(&right
->header
) -
1201 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1203 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1204 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1205 btrfs_item_size(right
->items
+ i
));
1206 push_space
= btrfs_item_offset(right
->items
+ i
);
1209 btrfs_mark_buffer_dirty(t
);
1210 btrfs_mark_buffer_dirty(right_buf
);
1211 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1215 /* then fixup the leaf pointer in the path */
1216 if (path
->slots
[0] < push_items
) {
1217 path
->slots
[0] += old_left_nritems
;
1218 btrfs_block_release(root
, path
->nodes
[0]);
1220 path
->slots
[1] -= 1;
1222 btrfs_block_release(root
, t
);
1223 path
->slots
[0] -= push_items
;
1225 BUG_ON(path
->slots
[0] < 0);
1230 * split the path's leaf in two, making sure there is at least data_size
1231 * available for the resulting leaf level of the path.
1233 * returns 0 if all went well and < 0 on failure.
1235 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1236 *root
, struct btrfs_key
*ins_key
,
1237 struct btrfs_path
*path
, int data_size
)
1239 struct buffer_head
*l_buf
;
1240 struct btrfs_leaf
*l
;
1244 struct btrfs_leaf
*right
;
1245 struct buffer_head
*right_buffer
;
1246 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1252 int double_split
= 0;
1253 struct btrfs_disk_key disk_key
;
1255 /* first try to make some room by pushing left and right */
1256 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1260 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1264 l_buf
= path
->nodes
[0];
1265 l
= btrfs_buffer_leaf(l_buf
);
1267 /* did the pushes work? */
1268 if (btrfs_leaf_free_space(root
, l
) >=
1269 sizeof(struct btrfs_item
) + data_size
)
1272 if (!path
->nodes
[1]) {
1273 ret
= insert_new_root(trans
, root
, path
, 1);
1277 slot
= path
->slots
[0];
1278 nritems
= btrfs_header_nritems(&l
->header
);
1279 mid
= (nritems
+ 1)/ 2;
1280 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1281 BUG_ON(!right_buffer
);
1282 right
= btrfs_buffer_leaf(right_buffer
);
1283 memset(&right
->header
, 0, sizeof(right
->header
));
1284 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1285 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1286 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1287 btrfs_set_header_level(&right
->header
, 0);
1288 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1289 sizeof(right
->header
.fsid
));
1292 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1293 BTRFS_LEAF_DATA_SIZE(root
)) {
1294 if (slot
>= nritems
) {
1295 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1296 btrfs_set_header_nritems(&right
->header
, 0);
1297 wret
= insert_ptr(trans
, root
, path
,
1299 bh_blocknr(right_buffer
),
1300 path
->slots
[1] + 1, 1);
1303 btrfs_block_release(root
, path
->nodes
[0]);
1304 path
->nodes
[0] = right_buffer
;
1306 path
->slots
[1] += 1;
1313 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1314 BTRFS_LEAF_DATA_SIZE(root
)) {
1316 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1317 btrfs_set_header_nritems(&right
->header
, 0);
1318 wret
= insert_ptr(trans
, root
, path
,
1320 bh_blocknr(right_buffer
),
1321 path
->slots
[1] - 1, 1);
1324 btrfs_block_release(root
, path
->nodes
[0]);
1325 path
->nodes
[0] = right_buffer
;
1327 path
->slots
[1] -= 1;
1328 if (path
->slots
[1] == 0) {
1329 wret
= fixup_low_keys(trans
, root
,
1330 path
, &disk_key
, 1);
1340 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1341 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1342 leaf_data_end(root
, l
);
1343 btrfs_memcpy(root
, right
, right
->items
, l
->items
+ mid
,
1344 (nritems
- mid
) * sizeof(struct btrfs_item
));
1345 btrfs_memcpy(root
, right
,
1346 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1347 data_copy_size
, btrfs_leaf_data(l
) +
1348 leaf_data_end(root
, l
), data_copy_size
);
1349 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1350 btrfs_item_end(l
->items
+ mid
);
1352 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1353 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1354 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1357 btrfs_set_header_nritems(&l
->header
, mid
);
1359 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1360 bh_blocknr(right_buffer
), path
->slots
[1] + 1, 1);
1363 btrfs_mark_buffer_dirty(right_buffer
);
1364 btrfs_mark_buffer_dirty(l_buf
);
1365 BUG_ON(path
->slots
[0] != slot
);
1367 btrfs_block_release(root
, path
->nodes
[0]);
1368 path
->nodes
[0] = right_buffer
;
1369 path
->slots
[0] -= mid
;
1370 path
->slots
[1] += 1;
1372 btrfs_block_release(root
, right_buffer
);
1373 BUG_ON(path
->slots
[0] < 0);
1377 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1378 BUG_ON(!right_buffer
);
1379 right
= btrfs_buffer_leaf(right_buffer
);
1380 memset(&right
->header
, 0, sizeof(right
->header
));
1381 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1382 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1383 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1384 btrfs_set_header_level(&right
->header
, 0);
1385 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1386 sizeof(right
->header
.fsid
));
1387 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1388 btrfs_set_header_nritems(&right
->header
, 0);
1389 wret
= insert_ptr(trans
, root
, path
,
1391 bh_blocknr(right_buffer
),
1395 if (path
->slots
[1] == 0) {
1396 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1400 btrfs_block_release(root
, path
->nodes
[0]);
1401 path
->nodes
[0] = right_buffer
;
1403 check_node(root
, path
, 1);
1404 check_leaf(root
, path
, 0);
1408 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
1409 struct btrfs_root
*root
,
1410 struct btrfs_path
*path
,
1416 struct btrfs_leaf
*leaf
;
1417 struct buffer_head
*leaf_buf
;
1419 unsigned int data_end
;
1420 unsigned int old_data_start
;
1421 unsigned int old_size
;
1422 unsigned int size_diff
;
1425 slot_orig
= path
->slots
[0];
1426 leaf_buf
= path
->nodes
[0];
1427 leaf
= btrfs_buffer_leaf(leaf_buf
);
1429 nritems
= btrfs_header_nritems(&leaf
->header
);
1430 data_end
= leaf_data_end(root
, leaf
);
1432 slot
= path
->slots
[0];
1433 old_data_start
= btrfs_item_offset(leaf
->items
+ slot
);
1434 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1435 BUG_ON(old_size
<= new_size
);
1436 size_diff
= old_size
- new_size
;
1439 BUG_ON(slot
>= nritems
);
1442 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1444 /* first correct the data pointers */
1445 for (i
= slot
; i
< nritems
; i
++) {
1446 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1447 btrfs_set_item_offset(leaf
->items
+ i
,
1450 /* shift the data */
1451 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1452 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
1453 data_end
, old_data_start
+ new_size
- data_end
);
1454 btrfs_set_item_size(leaf
->items
+ slot
, new_size
);
1455 btrfs_mark_buffer_dirty(leaf_buf
);
1458 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1460 check_leaf(root
, path
, 0);
1464 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1465 *root
, struct btrfs_path
*path
, u32 data_size
)
1470 struct btrfs_leaf
*leaf
;
1471 struct buffer_head
*leaf_buf
;
1473 unsigned int data_end
;
1474 unsigned int old_data
;
1475 unsigned int old_size
;
1478 slot_orig
= path
->slots
[0];
1479 leaf_buf
= path
->nodes
[0];
1480 leaf
= btrfs_buffer_leaf(leaf_buf
);
1482 nritems
= btrfs_header_nritems(&leaf
->header
);
1483 data_end
= leaf_data_end(root
, leaf
);
1485 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1487 slot
= path
->slots
[0];
1488 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1491 BUG_ON(slot
>= nritems
);
1494 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1496 /* first correct the data pointers */
1497 for (i
= slot
; i
< nritems
; i
++) {
1498 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1499 btrfs_set_item_offset(leaf
->items
+ i
,
1502 /* shift the data */
1503 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1504 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1505 data_end
, old_data
- data_end
);
1506 data_end
= old_data
;
1507 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1508 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1509 btrfs_mark_buffer_dirty(leaf_buf
);
1512 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1514 check_leaf(root
, path
, 0);
1519 * Given a key and some data, insert an item into the tree.
1520 * This does all the path init required, making room in the tree if needed.
1522 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1523 *root
, struct btrfs_path
*path
, struct btrfs_key
1524 *cpu_key
, u32 data_size
)
1529 struct btrfs_leaf
*leaf
;
1530 struct buffer_head
*leaf_buf
;
1532 unsigned int data_end
;
1533 struct btrfs_disk_key disk_key
;
1535 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1537 /* create a root if there isn't one */
1540 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1547 slot_orig
= path
->slots
[0];
1548 leaf_buf
= path
->nodes
[0];
1549 leaf
= btrfs_buffer_leaf(leaf_buf
);
1551 nritems
= btrfs_header_nritems(&leaf
->header
);
1552 data_end
= leaf_data_end(root
, leaf
);
1554 if (btrfs_leaf_free_space(root
, leaf
) <
1555 sizeof(struct btrfs_item
) + data_size
) {
1558 slot
= path
->slots
[0];
1560 if (slot
!= nritems
) {
1562 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1565 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1567 /* first correct the data pointers */
1568 for (i
= slot
; i
< nritems
; i
++) {
1569 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1570 btrfs_set_item_offset(leaf
->items
+ i
,
1574 /* shift the items */
1575 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
+ 1,
1577 (nritems
- slot
) * sizeof(struct btrfs_item
));
1579 /* shift the data */
1580 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1581 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1582 data_end
, old_data
- data_end
);
1583 data_end
= old_data
;
1585 /* setup the item for the new data */
1586 btrfs_memcpy(root
, leaf
, &leaf
->items
[slot
].key
, &disk_key
,
1587 sizeof(struct btrfs_disk_key
));
1588 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1589 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1590 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1591 btrfs_mark_buffer_dirty(leaf_buf
);
1595 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1597 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1599 check_leaf(root
, path
, 0);
1605 * Given a key and some data, insert an item into the tree.
1606 * This does all the path init required, making room in the tree if needed.
1608 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1609 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1613 struct btrfs_path
*path
;
1616 path
= btrfs_alloc_path();
1618 btrfs_init_path(path
);
1619 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
1621 ptr
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]),
1622 path
->slots
[0], u8
);
1623 btrfs_memcpy(root
, path
->nodes
[0]->b_data
,
1624 ptr
, data
, data_size
);
1625 btrfs_mark_buffer_dirty(path
->nodes
[0]);
1627 btrfs_release_path(root
, path
);
1628 btrfs_free_path(path
);
1633 * delete the pointer from a given node.
1635 * If the delete empties a node, the node is removed from the tree,
1636 * continuing all the way the root if required. The root is converted into
1637 * a leaf if all the nodes are emptied.
1639 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1640 struct btrfs_path
*path
, int level
, int slot
)
1642 struct btrfs_node
*node
;
1643 struct buffer_head
*parent
= path
->nodes
[level
];
1648 node
= btrfs_buffer_node(parent
);
1649 nritems
= btrfs_header_nritems(&node
->header
);
1650 if (slot
!= nritems
-1) {
1651 btrfs_memmove(root
, node
, node
->ptrs
+ slot
,
1652 node
->ptrs
+ slot
+ 1,
1653 sizeof(struct btrfs_key_ptr
) *
1654 (nritems
- slot
- 1));
1657 btrfs_set_header_nritems(&node
->header
, nritems
);
1658 if (nritems
== 0 && parent
== root
->node
) {
1659 struct btrfs_header
*header
= btrfs_buffer_header(root
->node
);
1660 BUG_ON(btrfs_header_level(header
) != 1);
1661 /* just turn the root into a leaf and break */
1662 btrfs_set_header_level(header
, 0);
1663 } else if (slot
== 0) {
1664 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1669 btrfs_mark_buffer_dirty(parent
);
1674 * delete the item at the leaf level in path. If that empties
1675 * the leaf, remove it from the tree
1677 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1678 struct btrfs_path
*path
)
1681 struct btrfs_leaf
*leaf
;
1682 struct buffer_head
*leaf_buf
;
1689 leaf_buf
= path
->nodes
[0];
1690 leaf
= btrfs_buffer_leaf(leaf_buf
);
1691 slot
= path
->slots
[0];
1692 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1693 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1694 nritems
= btrfs_header_nritems(&leaf
->header
);
1696 if (slot
!= nritems
- 1) {
1698 int data_end
= leaf_data_end(root
, leaf
);
1699 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1701 btrfs_leaf_data(leaf
) + data_end
,
1703 for (i
= slot
+ 1; i
< nritems
; i
++) {
1704 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1705 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1707 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
,
1708 leaf
->items
+ slot
+ 1,
1709 sizeof(struct btrfs_item
) *
1710 (nritems
- slot
- 1));
1712 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1714 /* delete the leaf if we've emptied it */
1716 if (leaf_buf
== root
->node
) {
1717 btrfs_set_header_level(&leaf
->header
, 0);
1719 clean_tree_block(trans
, root
, leaf_buf
);
1720 wait_on_buffer(leaf_buf
);
1721 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1724 wret
= btrfs_free_extent(trans
, root
,
1725 bh_blocknr(leaf_buf
), 1, 1);
1730 int used
= leaf_space_used(leaf
, 0, nritems
);
1732 wret
= fixup_low_keys(trans
, root
, path
,
1733 &leaf
->items
[0].key
, 1);
1738 /* delete the leaf if it is mostly empty */
1739 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1740 /* push_leaf_left fixes the path.
1741 * make sure the path still points to our leaf
1742 * for possible call to del_ptr below
1744 slot
= path
->slots
[1];
1746 wret
= push_leaf_left(trans
, root
, path
, 1);
1749 if (path
->nodes
[0] == leaf_buf
&&
1750 btrfs_header_nritems(&leaf
->header
)) {
1751 wret
= push_leaf_right(trans
, root
, path
, 1);
1755 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1756 u64 blocknr
= bh_blocknr(leaf_buf
);
1757 clean_tree_block(trans
, root
, leaf_buf
);
1758 wait_on_buffer(leaf_buf
);
1759 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1762 btrfs_block_release(root
, leaf_buf
);
1763 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1768 btrfs_mark_buffer_dirty(leaf_buf
);
1769 btrfs_block_release(root
, leaf_buf
);
1772 btrfs_mark_buffer_dirty(leaf_buf
);
1779 * walk up the tree as far as required to find the next leaf.
1780 * returns 0 if it found something or 1 if there are no greater leaves.
1781 * returns < 0 on io errors.
1783 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1788 struct buffer_head
*c
;
1789 struct btrfs_node
*c_node
;
1790 struct buffer_head
*next
= NULL
;
1792 while(level
< BTRFS_MAX_LEVEL
) {
1793 if (!path
->nodes
[level
])
1795 slot
= path
->slots
[level
] + 1;
1796 c
= path
->nodes
[level
];
1797 c_node
= btrfs_buffer_node(c
);
1798 if (slot
>= btrfs_header_nritems(&c_node
->header
)) {
1802 blocknr
= btrfs_node_blockptr(c_node
, slot
);
1804 btrfs_block_release(root
, next
);
1805 next
= read_tree_block(root
, blocknr
);
1808 path
->slots
[level
] = slot
;
1811 c
= path
->nodes
[level
];
1812 btrfs_block_release(root
, c
);
1813 path
->nodes
[level
] = next
;
1814 path
->slots
[level
] = 0;
1817 next
= read_tree_block(root
,
1818 btrfs_node_blockptr(btrfs_buffer_node(next
), 0));
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