2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/module.h>
22 #include "transaction.h"
24 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
25 *root
, struct btrfs_path
*path
, int level
);
26 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
27 *root
, struct btrfs_key
*ins_key
,
28 struct btrfs_path
*path
, int data_size
);
29 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
30 *root
, struct buffer_head
*dst
, struct buffer_head
32 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
33 btrfs_root
*root
, struct buffer_head
*dst_buf
,
34 struct buffer_head
*src_buf
);
35 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
36 struct btrfs_path
*path
, int level
, int slot
);
38 inline void btrfs_init_path(struct btrfs_path
*p
)
40 memset(p
, 0, sizeof(*p
));
43 struct btrfs_path
*btrfs_alloc_path(void)
45 struct btrfs_path
*path
;
46 path
= kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
48 btrfs_init_path(path
);
52 void btrfs_free_path(struct btrfs_path
*p
)
54 btrfs_release_path(NULL
, p
);
55 kmem_cache_free(btrfs_path_cachep
, p
);
58 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
61 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
64 btrfs_block_release(root
, p
->nodes
[i
]);
66 memset(p
, 0, sizeof(*p
));
69 static int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
70 *root
, struct buffer_head
*buf
, struct buffer_head
71 *parent
, int parent_slot
, struct buffer_head
74 struct buffer_head
*cow
;
75 struct btrfs_node
*cow_node
;
78 WARN_ON(!buffer_uptodate(buf
));
79 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
80 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
81 root
->fs_info
->running_transaction
->transid
);
84 if (trans
->transid
!= root
->fs_info
->generation
) {
85 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
86 root
->fs_info
->generation
);
89 if (btrfs_header_generation(btrfs_buffer_header(buf
)) ==
94 cow
= btrfs_alloc_free_block(trans
, root
, buf
->b_blocknr
);
97 cow_node
= btrfs_buffer_node(cow
);
98 if (buf
->b_size
!= root
->blocksize
|| cow
->b_size
!= root
->blocksize
)
100 memcpy(cow_node
, btrfs_buffer_node(buf
), root
->blocksize
);
101 btrfs_set_header_blocknr(&cow_node
->header
, bh_blocknr(cow
));
102 btrfs_set_header_generation(&cow_node
->header
, trans
->transid
);
103 btrfs_set_header_owner(&cow_node
->header
, root
->root_key
.objectid
);
104 ret
= btrfs_inc_ref(trans
, root
, buf
);
107 if (buf
== root
->node
) {
110 if (buf
!= root
->commit_root
) {
111 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
113 btrfs_block_release(root
, buf
);
115 btrfs_set_node_blockptr(btrfs_buffer_node(parent
), parent_slot
,
117 btrfs_mark_buffer_dirty(parent
);
118 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
120 btrfs_block_release(root
, buf
);
121 btrfs_mark_buffer_dirty(cow
);
127 * The leaf data grows from end-to-front in the node.
128 * this returns the address of the start of the last item,
129 * which is the stop of the leaf data stack
131 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
132 struct btrfs_leaf
*leaf
)
134 u32 nr
= btrfs_header_nritems(&leaf
->header
);
136 return BTRFS_LEAF_DATA_SIZE(root
);
137 return btrfs_item_offset(leaf
->items
+ nr
- 1);
141 * compare two keys in a memcmp fashion
143 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
147 btrfs_disk_key_to_cpu(&k1
, disk
);
149 if (k1
.objectid
> k2
->objectid
)
151 if (k1
.objectid
< k2
->objectid
)
153 if (k1
.flags
> k2
->flags
)
155 if (k1
.flags
< k2
->flags
)
157 if (k1
.offset
> k2
->offset
)
159 if (k1
.offset
< k2
->offset
)
164 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
167 struct btrfs_node
*parent
= NULL
;
168 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
171 struct btrfs_key cpukey
;
172 u32 nritems
= btrfs_header_nritems(&node
->header
);
174 if (path
->nodes
[level
+ 1])
175 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
176 parent_slot
= path
->slots
[level
+ 1];
177 slot
= path
->slots
[level
];
178 BUG_ON(nritems
== 0);
180 struct btrfs_disk_key
*parent_key
;
181 parent_key
= &parent
->ptrs
[parent_slot
].key
;
182 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
183 sizeof(struct btrfs_disk_key
)));
184 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
185 btrfs_header_blocknr(&node
->header
));
187 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
189 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
- 1].key
);
190 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) <= 0);
192 if (slot
< nritems
- 1) {
193 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
+ 1].key
);
194 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) >= 0);
199 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
202 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[level
]);
203 struct btrfs_node
*parent
= NULL
;
205 int slot
= path
->slots
[0];
206 struct btrfs_key cpukey
;
208 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
210 if (path
->nodes
[level
+ 1])
211 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
212 parent_slot
= path
->slots
[level
+ 1];
213 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
219 struct btrfs_disk_key
*parent_key
;
220 parent_key
= &parent
->ptrs
[parent_slot
].key
;
221 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
222 sizeof(struct btrfs_disk_key
)));
223 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
224 btrfs_header_blocknr(&leaf
->header
));
227 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
- 1].key
);
228 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) <= 0);
229 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
- 1) !=
230 btrfs_item_end(leaf
->items
+ slot
));
232 if (slot
< nritems
- 1) {
233 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
+ 1].key
);
234 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) >= 0);
235 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
) !=
236 btrfs_item_end(leaf
->items
+ slot
+ 1));
238 BUG_ON(btrfs_item_offset(leaf
->items
) +
239 btrfs_item_size(leaf
->items
) != BTRFS_LEAF_DATA_SIZE(root
));
243 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
246 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
247 if (memcmp(node
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
248 sizeof(node
->header
.fsid
)))
251 return check_leaf(root
, path
, level
);
252 return check_node(root
, path
, level
);
256 * search for key in the array p. items p are item_size apart
257 * and there are 'max' items in p
258 * the slot in the array is returned via slot, and it points to
259 * the place where you would insert key if it is not found in
262 * slot may point to max if the key is bigger than all of the keys
264 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
271 struct btrfs_disk_key
*tmp
;
274 mid
= (low
+ high
) / 2;
275 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
276 ret
= comp_keys(tmp
, key
);
292 * simple bin_search frontend that does the right thing for
295 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
297 if (btrfs_is_leaf(c
)) {
298 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
299 return generic_bin_search((void *)l
->items
,
300 sizeof(struct btrfs_item
),
301 key
, btrfs_header_nritems(&c
->header
),
304 return generic_bin_search((void *)c
->ptrs
,
305 sizeof(struct btrfs_key_ptr
),
306 key
, btrfs_header_nritems(&c
->header
),
312 static struct buffer_head
*read_node_slot(struct btrfs_root
*root
,
313 struct buffer_head
*parent_buf
,
316 struct btrfs_node
*node
= btrfs_buffer_node(parent_buf
);
319 if (slot
>= btrfs_header_nritems(&node
->header
))
321 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
324 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
325 *root
, struct btrfs_path
*path
, int level
)
327 struct buffer_head
*right_buf
;
328 struct buffer_head
*mid_buf
;
329 struct buffer_head
*left_buf
;
330 struct buffer_head
*parent_buf
= NULL
;
331 struct btrfs_node
*right
= NULL
;
332 struct btrfs_node
*mid
;
333 struct btrfs_node
*left
= NULL
;
334 struct btrfs_node
*parent
= NULL
;
338 int orig_slot
= path
->slots
[level
];
339 int err_on_enospc
= 0;
345 mid_buf
= path
->nodes
[level
];
346 mid
= btrfs_buffer_node(mid_buf
);
347 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
349 if (level
< BTRFS_MAX_LEVEL
- 1)
350 parent_buf
= path
->nodes
[level
+ 1];
351 pslot
= path
->slots
[level
+ 1];
354 * deal with the case where there is only one pointer in the root
355 * by promoting the node below to a root
358 struct buffer_head
*child
;
359 u64 blocknr
= bh_blocknr(mid_buf
);
361 if (btrfs_header_nritems(&mid
->header
) != 1)
364 /* promote the child to a root */
365 child
= read_node_slot(root
, mid_buf
, 0);
368 path
->nodes
[level
] = NULL
;
369 clean_tree_block(trans
, root
, mid_buf
);
370 wait_on_buffer(mid_buf
);
371 /* once for the path */
372 btrfs_block_release(root
, mid_buf
);
373 /* once for the root ptr */
374 btrfs_block_release(root
, mid_buf
);
375 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
377 parent
= btrfs_buffer_node(parent_buf
);
379 if (btrfs_header_nritems(&mid
->header
) >
380 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
383 if (btrfs_header_nritems(&mid
->header
) < 2)
386 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
387 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
389 /* first, try to make some room in the middle buffer */
391 wret
= btrfs_cow_block(trans
, root
, left_buf
,
392 parent_buf
, pslot
- 1, &left_buf
);
397 left
= btrfs_buffer_node(left_buf
);
398 orig_slot
+= btrfs_header_nritems(&left
->header
);
399 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
402 if (btrfs_header_nritems(&mid
->header
) < 2)
407 * then try to empty the right most buffer into the middle
410 wret
= btrfs_cow_block(trans
, root
, right_buf
,
411 parent_buf
, pslot
+ 1, &right_buf
);
417 right
= btrfs_buffer_node(right_buf
);
418 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
419 if (wret
< 0 && wret
!= -ENOSPC
)
421 if (btrfs_header_nritems(&right
->header
) == 0) {
422 u64 blocknr
= bh_blocknr(right_buf
);
423 clean_tree_block(trans
, root
, right_buf
);
424 wait_on_buffer(right_buf
);
425 btrfs_block_release(root
, right_buf
);
428 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
432 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
436 btrfs_memcpy(root
, parent
,
437 &parent
->ptrs
[pslot
+ 1].key
,
439 sizeof(struct btrfs_disk_key
));
440 btrfs_mark_buffer_dirty(parent_buf
);
443 if (btrfs_header_nritems(&mid
->header
) == 1) {
445 * we're not allowed to leave a node with one item in the
446 * tree during a delete. A deletion from lower in the tree
447 * could try to delete the only pointer in this node.
448 * So, pull some keys from the left.
449 * There has to be a left pointer at this point because
450 * otherwise we would have pulled some pointers from the
454 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
461 if (btrfs_header_nritems(&mid
->header
) == 0) {
462 /* we've managed to empty the middle node, drop it */
463 u64 blocknr
= bh_blocknr(mid_buf
);
464 clean_tree_block(trans
, root
, mid_buf
);
465 wait_on_buffer(mid_buf
);
466 btrfs_block_release(root
, mid_buf
);
469 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
472 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
476 /* update the parent key to reflect our changes */
477 btrfs_memcpy(root
, parent
,
478 &parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
479 sizeof(struct btrfs_disk_key
));
480 btrfs_mark_buffer_dirty(parent_buf
);
483 /* update the path */
485 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
487 path
->nodes
[level
] = left_buf
;
488 path
->slots
[level
+ 1] -= 1;
489 path
->slots
[level
] = orig_slot
;
491 btrfs_block_release(root
, mid_buf
);
493 orig_slot
-= btrfs_header_nritems(&left
->header
);
494 path
->slots
[level
] = orig_slot
;
497 /* double check we haven't messed things up */
498 check_block(root
, path
, level
);
500 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[level
]),
505 btrfs_block_release(root
, right_buf
);
507 btrfs_block_release(root
, left_buf
);
511 /* returns zero if the push worked, non-zero otherwise */
512 static int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
513 struct btrfs_root
*root
,
514 struct btrfs_path
*path
, int level
)
516 struct buffer_head
*right_buf
;
517 struct buffer_head
*mid_buf
;
518 struct buffer_head
*left_buf
;
519 struct buffer_head
*parent_buf
= NULL
;
520 struct btrfs_node
*right
= NULL
;
521 struct btrfs_node
*mid
;
522 struct btrfs_node
*left
= NULL
;
523 struct btrfs_node
*parent
= NULL
;
527 int orig_slot
= path
->slots
[level
];
533 mid_buf
= path
->nodes
[level
];
534 mid
= btrfs_buffer_node(mid_buf
);
535 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
537 if (level
< BTRFS_MAX_LEVEL
- 1)
538 parent_buf
= path
->nodes
[level
+ 1];
539 pslot
= path
->slots
[level
+ 1];
543 parent
= btrfs_buffer_node(parent_buf
);
545 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
547 /* first, try to make some room in the middle buffer */
550 left
= btrfs_buffer_node(left_buf
);
551 left_nr
= btrfs_header_nritems(&left
->header
);
552 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
555 ret
= btrfs_cow_block(trans
, root
, left_buf
, parent_buf
,
556 pslot
- 1, &left_buf
);
560 left
= btrfs_buffer_node(left_buf
);
561 wret
= push_node_left(trans
, root
,
568 orig_slot
+= left_nr
;
569 btrfs_memcpy(root
, parent
,
570 &parent
->ptrs
[pslot
].key
,
572 sizeof(struct btrfs_disk_key
));
573 btrfs_mark_buffer_dirty(parent_buf
);
574 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
575 path
->nodes
[level
] = left_buf
;
576 path
->slots
[level
+ 1] -= 1;
577 path
->slots
[level
] = orig_slot
;
578 btrfs_block_release(root
, mid_buf
);
581 btrfs_header_nritems(&left
->header
);
582 path
->slots
[level
] = orig_slot
;
583 btrfs_block_release(root
, left_buf
);
585 check_node(root
, path
, level
);
588 btrfs_block_release(root
, left_buf
);
590 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
593 * then try to empty the right most buffer into the middle
597 right
= btrfs_buffer_node(right_buf
);
598 right_nr
= btrfs_header_nritems(&right
->header
);
599 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
602 ret
= btrfs_cow_block(trans
, root
, right_buf
,
603 parent_buf
, pslot
+ 1,
608 right
= btrfs_buffer_node(right_buf
);
609 wret
= balance_node_right(trans
, root
,
616 btrfs_memcpy(root
, parent
,
617 &parent
->ptrs
[pslot
+ 1].key
,
619 sizeof(struct btrfs_disk_key
));
620 btrfs_mark_buffer_dirty(parent_buf
);
621 if (btrfs_header_nritems(&mid
->header
) <= orig_slot
) {
622 path
->nodes
[level
] = right_buf
;
623 path
->slots
[level
+ 1] += 1;
624 path
->slots
[level
] = orig_slot
-
625 btrfs_header_nritems(&mid
->header
);
626 btrfs_block_release(root
, mid_buf
);
628 btrfs_block_release(root
, right_buf
);
630 check_node(root
, path
, level
);
633 btrfs_block_release(root
, right_buf
);
635 check_node(root
, path
, level
);
640 * look for key in the tree. path is filled in with nodes along the way
641 * if key is found, we return zero and you can find the item in the leaf
642 * level of the path (level 0)
644 * If the key isn't found, the path points to the slot where it should
645 * be inserted, and 1 is returned. If there are other errors during the
646 * search a negative error number is returned.
648 * if ins_len > 0, nodes and leaves will be split as we walk down the
649 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
652 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
653 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
656 struct buffer_head
*b
;
657 struct buffer_head
*cow_buf
;
658 struct btrfs_node
*c
;
663 WARN_ON(p
->nodes
[0] != NULL
);
664 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
669 c
= btrfs_buffer_node(b
);
670 level
= btrfs_header_level(&c
->header
);
673 wret
= btrfs_cow_block(trans
, root
, b
,
678 btrfs_block_release(root
, cow_buf
);
682 c
= btrfs_buffer_node(b
);
684 BUG_ON(!cow
&& ins_len
);
685 if (level
!= btrfs_header_level(&c
->header
))
687 level
= btrfs_header_level(&c
->header
);
689 ret
= check_block(root
, p
, level
);
692 ret
= bin_search(c
, key
, &slot
);
693 if (!btrfs_is_leaf(c
)) {
696 p
->slots
[level
] = slot
;
697 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) >=
698 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
699 int sret
= split_node(trans
, root
, p
, level
);
704 c
= btrfs_buffer_node(b
);
705 slot
= p
->slots
[level
];
706 } else if (ins_len
< 0) {
707 int sret
= balance_level(trans
, root
, p
,
714 c
= btrfs_buffer_node(b
);
715 slot
= p
->slots
[level
];
716 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
718 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
720 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
721 p
->slots
[level
] = slot
;
722 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
723 sizeof(struct btrfs_item
) + ins_len
) {
724 int sret
= split_leaf(trans
, root
, key
,
737 * adjust the pointers going up the tree, starting at level
738 * making sure the right key of each node is points to 'key'.
739 * This is used after shifting pointers to the left, so it stops
740 * fixing up pointers when a given leaf/node is not in slot 0 of the
743 * If this fails to write a tree block, it returns -1, but continues
744 * fixing up the blocks in ram so the tree is consistent.
746 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
747 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
752 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
753 struct btrfs_node
*t
;
754 int tslot
= path
->slots
[i
];
757 t
= btrfs_buffer_node(path
->nodes
[i
]);
758 btrfs_memcpy(root
, t
, &t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
759 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
767 * try to push data from one node into the next node left in the
770 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
771 * error, and > 0 if there was no room in the left hand block.
773 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
774 *root
, struct buffer_head
*dst_buf
, struct
775 buffer_head
*src_buf
)
777 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
778 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
784 src_nritems
= btrfs_header_nritems(&src
->header
);
785 dst_nritems
= btrfs_header_nritems(&dst
->header
);
786 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
788 if (push_items
<= 0) {
792 if (src_nritems
< push_items
)
793 push_items
= src_nritems
;
795 btrfs_memcpy(root
, dst
, dst
->ptrs
+ dst_nritems
, src
->ptrs
,
796 push_items
* sizeof(struct btrfs_key_ptr
));
797 if (push_items
< src_nritems
) {
798 btrfs_memmove(root
, src
, src
->ptrs
, src
->ptrs
+ push_items
,
799 (src_nritems
- push_items
) *
800 sizeof(struct btrfs_key_ptr
));
802 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
803 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
804 btrfs_mark_buffer_dirty(src_buf
);
805 btrfs_mark_buffer_dirty(dst_buf
);
810 * try to push data from one node into the next node right in the
813 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
814 * error, and > 0 if there was no room in the right hand block.
816 * this will only push up to 1/2 the contents of the left node over
818 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
819 btrfs_root
*root
, struct buffer_head
*dst_buf
,
820 struct buffer_head
*src_buf
)
822 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
823 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
830 src_nritems
= btrfs_header_nritems(&src
->header
);
831 dst_nritems
= btrfs_header_nritems(&dst
->header
);
832 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
833 if (push_items
<= 0) {
837 max_push
= src_nritems
/ 2 + 1;
838 /* don't try to empty the node */
839 if (max_push
> src_nritems
)
841 if (max_push
< push_items
)
842 push_items
= max_push
;
844 btrfs_memmove(root
, dst
, dst
->ptrs
+ push_items
, dst
->ptrs
,
845 dst_nritems
* sizeof(struct btrfs_key_ptr
));
847 btrfs_memcpy(root
, dst
, dst
->ptrs
,
848 src
->ptrs
+ src_nritems
- push_items
,
849 push_items
* sizeof(struct btrfs_key_ptr
));
851 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
852 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
854 btrfs_mark_buffer_dirty(src_buf
);
855 btrfs_mark_buffer_dirty(dst_buf
);
860 * helper function to insert a new root level in the tree.
861 * A new node is allocated, and a single item is inserted to
862 * point to the existing root
864 * returns zero on success or < 0 on failure.
866 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
867 *root
, struct btrfs_path
*path
, int level
)
869 struct buffer_head
*t
;
870 struct btrfs_node
*lower
;
871 struct btrfs_node
*c
;
872 struct btrfs_disk_key
*lower_key
;
874 BUG_ON(path
->nodes
[level
]);
875 BUG_ON(path
->nodes
[level
-1] != root
->node
);
877 t
= btrfs_alloc_free_block(trans
, root
, root
->node
->b_blocknr
);
880 c
= btrfs_buffer_node(t
);
881 memset(c
, 0, root
->blocksize
);
882 btrfs_set_header_nritems(&c
->header
, 1);
883 btrfs_set_header_level(&c
->header
, level
);
884 btrfs_set_header_blocknr(&c
->header
, bh_blocknr(t
));
885 btrfs_set_header_generation(&c
->header
, trans
->transid
);
886 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
887 lower
= btrfs_buffer_node(path
->nodes
[level
-1]);
888 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
889 sizeof(c
->header
.fsid
));
890 if (btrfs_is_leaf(lower
))
891 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
893 lower_key
= &lower
->ptrs
[0].key
;
894 btrfs_memcpy(root
, c
, &c
->ptrs
[0].key
, lower_key
,
895 sizeof(struct btrfs_disk_key
));
896 btrfs_set_node_blockptr(c
, 0, bh_blocknr(path
->nodes
[level
- 1]));
898 btrfs_mark_buffer_dirty(t
);
900 /* the super has an extra ref to root->node */
901 btrfs_block_release(root
, root
->node
);
904 path
->nodes
[level
] = t
;
905 path
->slots
[level
] = 0;
910 * worker function to insert a single pointer in a node.
911 * the node should have enough room for the pointer already
913 * slot and level indicate where you want the key to go, and
914 * blocknr is the block the key points to.
916 * returns zero on success and < 0 on any error
918 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
919 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
920 *key
, u64 blocknr
, int slot
, int level
)
922 struct btrfs_node
*lower
;
925 BUG_ON(!path
->nodes
[level
]);
926 lower
= btrfs_buffer_node(path
->nodes
[level
]);
927 nritems
= btrfs_header_nritems(&lower
->header
);
930 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
932 if (slot
!= nritems
) {
933 btrfs_memmove(root
, lower
, lower
->ptrs
+ slot
+ 1,
935 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
937 btrfs_memcpy(root
, lower
, &lower
->ptrs
[slot
].key
,
938 key
, sizeof(struct btrfs_disk_key
));
939 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
940 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
941 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
942 check_node(root
, path
, level
);
947 * split the node at the specified level in path in two.
948 * The path is corrected to point to the appropriate node after the split
950 * Before splitting this tries to make some room in the node by pushing
951 * left and right, if either one works, it returns right away.
953 * returns 0 on success and < 0 on failure
955 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
956 *root
, struct btrfs_path
*path
, int level
)
958 struct buffer_head
*t
;
959 struct btrfs_node
*c
;
960 struct buffer_head
*split_buffer
;
961 struct btrfs_node
*split
;
967 t
= path
->nodes
[level
];
968 c
= btrfs_buffer_node(t
);
969 if (t
== root
->node
) {
970 /* trying to split the root, lets make a new one */
971 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
975 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
976 t
= path
->nodes
[level
];
977 c
= btrfs_buffer_node(t
);
979 btrfs_header_nritems(&c
->header
) <
980 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1)
986 c_nritems
= btrfs_header_nritems(&c
->header
);
987 split_buffer
= btrfs_alloc_free_block(trans
, root
, t
->b_blocknr
);
988 if (IS_ERR(split_buffer
))
989 return PTR_ERR(split_buffer
);
991 split
= btrfs_buffer_node(split_buffer
);
992 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
993 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
994 btrfs_set_header_blocknr(&split
->header
, bh_blocknr(split_buffer
));
995 btrfs_set_header_generation(&split
->header
, trans
->transid
);
996 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
997 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
998 sizeof(split
->header
.fsid
));
999 mid
= (c_nritems
+ 1) / 2;
1000 btrfs_memcpy(root
, split
, split
->ptrs
, c
->ptrs
+ mid
,
1001 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
1002 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
1003 btrfs_set_header_nritems(&c
->header
, mid
);
1006 btrfs_mark_buffer_dirty(t
);
1007 btrfs_mark_buffer_dirty(split_buffer
);
1008 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
1009 bh_blocknr(split_buffer
), path
->slots
[level
+ 1] + 1,
1014 if (path
->slots
[level
] >= mid
) {
1015 path
->slots
[level
] -= mid
;
1016 btrfs_block_release(root
, t
);
1017 path
->nodes
[level
] = split_buffer
;
1018 path
->slots
[level
+ 1] += 1;
1020 btrfs_block_release(root
, split_buffer
);
1026 * how many bytes are required to store the items in a leaf. start
1027 * and nr indicate which items in the leaf to check. This totals up the
1028 * space used both by the item structs and the item data
1030 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
1033 int nritems
= btrfs_header_nritems(&l
->header
);
1034 int end
= min(nritems
, start
+ nr
) - 1;
1038 data_len
= btrfs_item_end(l
->items
+ start
);
1039 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
1040 data_len
+= sizeof(struct btrfs_item
) * nr
;
1041 WARN_ON(data_len
< 0);
1046 * The space between the end of the leaf items and
1047 * the start of the leaf data. IOW, how much room
1048 * the leaf has left for both items and data
1050 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
1052 int nritems
= btrfs_header_nritems(&leaf
->header
);
1053 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
1057 * push some data in the path leaf to the right, trying to free up at
1058 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1060 * returns 1 if the push failed because the other node didn't have enough
1061 * room, 0 if everything worked out and < 0 if there were major errors.
1063 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
1064 *root
, struct btrfs_path
*path
, int data_size
)
1066 struct buffer_head
*left_buf
= path
->nodes
[0];
1067 struct btrfs_leaf
*left
= btrfs_buffer_leaf(left_buf
);
1068 struct btrfs_leaf
*right
;
1069 struct buffer_head
*right_buf
;
1070 struct buffer_head
*upper
;
1071 struct btrfs_node
*upper_node
;
1077 struct btrfs_item
*item
;
1082 slot
= path
->slots
[1];
1083 if (!path
->nodes
[1]) {
1086 upper
= path
->nodes
[1];
1087 upper_node
= btrfs_buffer_node(upper
);
1088 if (slot
>= btrfs_header_nritems(&upper_node
->header
) - 1) {
1091 right_buf
= read_tree_block(root
,
1092 btrfs_node_blockptr(btrfs_buffer_node(upper
), slot
+ 1));
1093 right
= btrfs_buffer_leaf(right_buf
);
1094 free_space
= btrfs_leaf_free_space(root
, right
);
1095 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1096 btrfs_block_release(root
, right_buf
);
1099 /* cow and double check */
1100 ret
= btrfs_cow_block(trans
, root
, right_buf
, upper
,
1101 slot
+ 1, &right_buf
);
1103 btrfs_block_release(root
, right_buf
);
1106 right
= btrfs_buffer_leaf(right_buf
);
1107 free_space
= btrfs_leaf_free_space(root
, right
);
1108 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1109 btrfs_block_release(root
, right_buf
);
1113 left_nritems
= btrfs_header_nritems(&left
->header
);
1114 if (left_nritems
== 0) {
1115 btrfs_block_release(root
, right_buf
);
1118 for (i
= left_nritems
- 1; i
>= 1; i
--) {
1119 item
= left
->items
+ i
;
1120 if (path
->slots
[0] == i
)
1121 push_space
+= data_size
+ sizeof(*item
);
1122 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1126 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1128 if (push_items
== 0) {
1129 btrfs_block_release(root
, right_buf
);
1132 if (push_items
== left_nritems
)
1134 right_nritems
= btrfs_header_nritems(&right
->header
);
1135 /* push left to right */
1136 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
1137 push_space
-= leaf_data_end(root
, left
);
1138 /* make room in the right data area */
1139 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1140 leaf_data_end(root
, right
) - push_space
,
1141 btrfs_leaf_data(right
) +
1142 leaf_data_end(root
, right
), BTRFS_LEAF_DATA_SIZE(root
) -
1143 leaf_data_end(root
, right
));
1144 /* copy from the left data area */
1145 btrfs_memcpy(root
, right
, btrfs_leaf_data(right
) +
1146 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1147 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1149 btrfs_memmove(root
, right
, right
->items
+ push_items
, right
->items
,
1150 right_nritems
* sizeof(struct btrfs_item
));
1151 /* copy the items from left to right */
1152 btrfs_memcpy(root
, right
, right
->items
, left
->items
+
1153 left_nritems
- push_items
,
1154 push_items
* sizeof(struct btrfs_item
));
1156 /* update the item pointers */
1157 right_nritems
+= push_items
;
1158 btrfs_set_header_nritems(&right
->header
, right_nritems
);
1159 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1160 for (i
= 0; i
< right_nritems
; i
++) {
1161 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1162 btrfs_item_size(right
->items
+ i
));
1163 push_space
= btrfs_item_offset(right
->items
+ i
);
1165 left_nritems
-= push_items
;
1166 btrfs_set_header_nritems(&left
->header
, left_nritems
);
1168 btrfs_mark_buffer_dirty(left_buf
);
1169 btrfs_mark_buffer_dirty(right_buf
);
1171 btrfs_memcpy(root
, upper_node
, &upper_node
->ptrs
[slot
+ 1].key
,
1172 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
1173 btrfs_mark_buffer_dirty(upper
);
1175 /* then fixup the leaf pointer in the path */
1176 if (path
->slots
[0] >= left_nritems
) {
1177 path
->slots
[0] -= left_nritems
;
1178 btrfs_block_release(root
, path
->nodes
[0]);
1179 path
->nodes
[0] = right_buf
;
1180 path
->slots
[1] += 1;
1182 btrfs_block_release(root
, right_buf
);
1185 check_node(root
, path
, 1);
1189 * push some data in the path leaf to the left, trying to free up at
1190 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1192 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1193 *root
, struct btrfs_path
*path
, int data_size
)
1195 struct buffer_head
*right_buf
= path
->nodes
[0];
1196 struct btrfs_leaf
*right
= btrfs_buffer_leaf(right_buf
);
1197 struct buffer_head
*t
;
1198 struct btrfs_leaf
*left
;
1204 struct btrfs_item
*item
;
1205 u32 old_left_nritems
;
1209 slot
= path
->slots
[1];
1213 if (!path
->nodes
[1]) {
1216 t
= read_tree_block(root
,
1217 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[1]), slot
- 1));
1218 left
= btrfs_buffer_leaf(t
);
1219 free_space
= btrfs_leaf_free_space(root
, left
);
1220 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1221 btrfs_block_release(root
, t
);
1225 /* cow and double check */
1226 ret
= btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
1228 /* we hit -ENOSPC, but it isn't fatal here */
1231 left
= btrfs_buffer_leaf(t
);
1232 free_space
= btrfs_leaf_free_space(root
, left
);
1233 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1234 btrfs_block_release(root
, t
);
1238 if (btrfs_header_nritems(&right
->header
) == 0) {
1239 btrfs_block_release(root
, t
);
1243 for (i
= 0; i
< btrfs_header_nritems(&right
->header
) - 1; i
++) {
1244 item
= right
->items
+ i
;
1245 if (path
->slots
[0] == i
)
1246 push_space
+= data_size
+ sizeof(*item
);
1247 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1251 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1253 if (push_items
== 0) {
1254 btrfs_block_release(root
, t
);
1257 if (push_items
== btrfs_header_nritems(&right
->header
))
1259 /* push data from right to left */
1260 btrfs_memcpy(root
, left
, left
->items
+
1261 btrfs_header_nritems(&left
->header
),
1262 right
->items
, push_items
* sizeof(struct btrfs_item
));
1263 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1264 btrfs_item_offset(right
->items
+ push_items
-1);
1265 btrfs_memcpy(root
, left
, btrfs_leaf_data(left
) +
1266 leaf_data_end(root
, left
) - push_space
,
1267 btrfs_leaf_data(right
) +
1268 btrfs_item_offset(right
->items
+ push_items
- 1),
1270 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1271 BUG_ON(old_left_nritems
< 0);
1273 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1274 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1275 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1276 (BTRFS_LEAF_DATA_SIZE(root
) -
1277 btrfs_item_offset(left
->items
+
1278 old_left_nritems
- 1)));
1280 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1282 /* fixup right node */
1283 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1284 leaf_data_end(root
, right
);
1285 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1286 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1287 btrfs_leaf_data(right
) +
1288 leaf_data_end(root
, right
), push_space
);
1289 btrfs_memmove(root
, right
, right
->items
, right
->items
+ push_items
,
1290 (btrfs_header_nritems(&right
->header
) - push_items
) *
1291 sizeof(struct btrfs_item
));
1292 btrfs_set_header_nritems(&right
->header
,
1293 btrfs_header_nritems(&right
->header
) -
1295 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1297 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1298 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1299 btrfs_item_size(right
->items
+ i
));
1300 push_space
= btrfs_item_offset(right
->items
+ i
);
1303 btrfs_mark_buffer_dirty(t
);
1304 btrfs_mark_buffer_dirty(right_buf
);
1306 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1310 /* then fixup the leaf pointer in the path */
1311 if (path
->slots
[0] < push_items
) {
1312 path
->slots
[0] += old_left_nritems
;
1313 btrfs_block_release(root
, path
->nodes
[0]);
1315 path
->slots
[1] -= 1;
1317 btrfs_block_release(root
, t
);
1318 path
->slots
[0] -= push_items
;
1320 BUG_ON(path
->slots
[0] < 0);
1322 check_node(root
, path
, 1);
1327 * split the path's leaf in two, making sure there is at least data_size
1328 * available for the resulting leaf level of the path.
1330 * returns 0 if all went well and < 0 on failure.
1332 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1333 *root
, struct btrfs_key
*ins_key
,
1334 struct btrfs_path
*path
, int data_size
)
1336 struct buffer_head
*l_buf
;
1337 struct btrfs_leaf
*l
;
1341 struct btrfs_leaf
*right
;
1342 struct buffer_head
*right_buffer
;
1343 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1349 int double_split
= 0;
1350 struct btrfs_disk_key disk_key
;
1352 /* first try to make some room by pushing left and right */
1353 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1357 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1361 l_buf
= path
->nodes
[0];
1362 l
= btrfs_buffer_leaf(l_buf
);
1364 /* did the pushes work? */
1365 if (btrfs_leaf_free_space(root
, l
) >=
1366 sizeof(struct btrfs_item
) + data_size
)
1369 if (!path
->nodes
[1]) {
1370 ret
= insert_new_root(trans
, root
, path
, 1);
1374 slot
= path
->slots
[0];
1375 nritems
= btrfs_header_nritems(&l
->header
);
1376 mid
= (nritems
+ 1)/ 2;
1378 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1379 if (IS_ERR(right_buffer
))
1380 return PTR_ERR(right_buffer
);
1382 right
= btrfs_buffer_leaf(right_buffer
);
1383 memset(&right
->header
, 0, sizeof(right
->header
));
1384 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1385 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1386 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1387 btrfs_set_header_level(&right
->header
, 0);
1388 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1389 sizeof(right
->header
.fsid
));
1392 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1393 BTRFS_LEAF_DATA_SIZE(root
)) {
1394 if (slot
>= nritems
) {
1395 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1396 btrfs_set_header_nritems(&right
->header
, 0);
1397 wret
= insert_ptr(trans
, root
, path
,
1399 bh_blocknr(right_buffer
),
1400 path
->slots
[1] + 1, 1);
1403 btrfs_block_release(root
, path
->nodes
[0]);
1404 path
->nodes
[0] = right_buffer
;
1406 path
->slots
[1] += 1;
1413 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1414 BTRFS_LEAF_DATA_SIZE(root
)) {
1416 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1417 btrfs_set_header_nritems(&right
->header
, 0);
1418 wret
= insert_ptr(trans
, root
, path
,
1420 bh_blocknr(right_buffer
),
1424 btrfs_block_release(root
, path
->nodes
[0]);
1425 path
->nodes
[0] = right_buffer
;
1427 if (path
->slots
[1] == 0) {
1428 wret
= fixup_low_keys(trans
, root
,
1429 path
, &disk_key
, 1);
1439 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1440 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1441 leaf_data_end(root
, l
);
1442 btrfs_memcpy(root
, right
, right
->items
, l
->items
+ mid
,
1443 (nritems
- mid
) * sizeof(struct btrfs_item
));
1444 btrfs_memcpy(root
, right
,
1445 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1446 data_copy_size
, btrfs_leaf_data(l
) +
1447 leaf_data_end(root
, l
), data_copy_size
);
1448 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1449 btrfs_item_end(l
->items
+ mid
);
1451 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1452 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1453 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1456 btrfs_set_header_nritems(&l
->header
, mid
);
1458 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1459 bh_blocknr(right_buffer
), path
->slots
[1] + 1, 1);
1462 btrfs_mark_buffer_dirty(right_buffer
);
1463 btrfs_mark_buffer_dirty(l_buf
);
1464 BUG_ON(path
->slots
[0] != slot
);
1466 btrfs_block_release(root
, path
->nodes
[0]);
1467 path
->nodes
[0] = right_buffer
;
1468 path
->slots
[0] -= mid
;
1469 path
->slots
[1] += 1;
1471 btrfs_block_release(root
, right_buffer
);
1472 BUG_ON(path
->slots
[0] < 0);
1473 check_node(root
, path
, 1);
1477 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1478 if (IS_ERR(right_buffer
))
1479 return PTR_ERR(right_buffer
);
1481 right
= btrfs_buffer_leaf(right_buffer
);
1482 memset(&right
->header
, 0, sizeof(right
->header
));
1483 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1484 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1485 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1486 btrfs_set_header_level(&right
->header
, 0);
1487 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1488 sizeof(right
->header
.fsid
));
1489 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1490 btrfs_set_header_nritems(&right
->header
, 0);
1491 wret
= insert_ptr(trans
, root
, path
,
1493 bh_blocknr(right_buffer
),
1497 if (path
->slots
[1] == 0) {
1498 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1502 btrfs_block_release(root
, path
->nodes
[0]);
1503 path
->nodes
[0] = right_buffer
;
1505 check_node(root
, path
, 1);
1506 check_leaf(root
, path
, 0);
1510 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
1511 struct btrfs_root
*root
,
1512 struct btrfs_path
*path
,
1518 struct btrfs_leaf
*leaf
;
1519 struct buffer_head
*leaf_buf
;
1521 unsigned int data_end
;
1522 unsigned int old_data_start
;
1523 unsigned int old_size
;
1524 unsigned int size_diff
;
1527 slot_orig
= path
->slots
[0];
1528 leaf_buf
= path
->nodes
[0];
1529 leaf
= btrfs_buffer_leaf(leaf_buf
);
1531 nritems
= btrfs_header_nritems(&leaf
->header
);
1532 data_end
= leaf_data_end(root
, leaf
);
1534 slot
= path
->slots
[0];
1535 old_data_start
= btrfs_item_offset(leaf
->items
+ slot
);
1536 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1537 BUG_ON(old_size
<= new_size
);
1538 size_diff
= old_size
- new_size
;
1541 BUG_ON(slot
>= nritems
);
1544 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1546 /* first correct the data pointers */
1547 for (i
= slot
; i
< nritems
; i
++) {
1548 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1549 btrfs_set_item_offset(leaf
->items
+ i
,
1552 /* shift the data */
1553 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1554 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
1555 data_end
, old_data_start
+ new_size
- data_end
);
1556 btrfs_set_item_size(leaf
->items
+ slot
, new_size
);
1557 btrfs_mark_buffer_dirty(leaf_buf
);
1560 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1562 check_leaf(root
, path
, 0);
1566 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1567 *root
, struct btrfs_path
*path
, u32 data_size
)
1572 struct btrfs_leaf
*leaf
;
1573 struct buffer_head
*leaf_buf
;
1575 unsigned int data_end
;
1576 unsigned int old_data
;
1577 unsigned int old_size
;
1580 slot_orig
= path
->slots
[0];
1581 leaf_buf
= path
->nodes
[0];
1582 leaf
= btrfs_buffer_leaf(leaf_buf
);
1584 nritems
= btrfs_header_nritems(&leaf
->header
);
1585 data_end
= leaf_data_end(root
, leaf
);
1587 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1589 slot
= path
->slots
[0];
1590 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1593 BUG_ON(slot
>= nritems
);
1596 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1598 /* first correct the data pointers */
1599 for (i
= slot
; i
< nritems
; i
++) {
1600 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1601 btrfs_set_item_offset(leaf
->items
+ i
,
1604 /* shift the data */
1605 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1606 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1607 data_end
, old_data
- data_end
);
1608 data_end
= old_data
;
1609 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1610 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1611 btrfs_mark_buffer_dirty(leaf_buf
);
1614 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1616 check_leaf(root
, path
, 0);
1621 * Given a key and some data, insert an item into the tree.
1622 * This does all the path init required, making room in the tree if needed.
1624 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1625 *root
, struct btrfs_path
*path
, struct btrfs_key
1626 *cpu_key
, u32 data_size
)
1631 struct btrfs_leaf
*leaf
;
1632 struct buffer_head
*leaf_buf
;
1634 unsigned int data_end
;
1635 struct btrfs_disk_key disk_key
;
1637 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1639 /* create a root if there isn't one */
1642 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1649 slot_orig
= path
->slots
[0];
1650 leaf_buf
= path
->nodes
[0];
1651 leaf
= btrfs_buffer_leaf(leaf_buf
);
1653 nritems
= btrfs_header_nritems(&leaf
->header
);
1654 data_end
= leaf_data_end(root
, leaf
);
1656 if (btrfs_leaf_free_space(root
, leaf
) <
1657 sizeof(struct btrfs_item
) + data_size
) {
1660 slot
= path
->slots
[0];
1662 if (slot
!= nritems
) {
1664 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1667 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1669 /* first correct the data pointers */
1670 for (i
= slot
; i
< nritems
; i
++) {
1671 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1672 btrfs_set_item_offset(leaf
->items
+ i
,
1676 /* shift the items */
1677 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
+ 1,
1679 (nritems
- slot
) * sizeof(struct btrfs_item
));
1681 /* shift the data */
1682 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1683 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1684 data_end
, old_data
- data_end
);
1685 data_end
= old_data
;
1687 /* setup the item for the new data */
1688 btrfs_memcpy(root
, leaf
, &leaf
->items
[slot
].key
, &disk_key
,
1689 sizeof(struct btrfs_disk_key
));
1690 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1691 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1692 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1693 btrfs_mark_buffer_dirty(leaf_buf
);
1697 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1699 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1701 check_leaf(root
, path
, 0);
1707 * Given a key and some data, insert an item into the tree.
1708 * This does all the path init required, making room in the tree if needed.
1710 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1711 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1715 struct btrfs_path
*path
;
1718 path
= btrfs_alloc_path();
1720 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
1722 ptr
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]),
1723 path
->slots
[0], u8
);
1724 btrfs_memcpy(root
, path
->nodes
[0]->b_data
,
1725 ptr
, data
, data_size
);
1726 btrfs_mark_buffer_dirty(path
->nodes
[0]);
1728 btrfs_free_path(path
);
1733 * delete the pointer from a given node.
1735 * If the delete empties a node, the node is removed from the tree,
1736 * continuing all the way the root if required. The root is converted into
1737 * a leaf if all the nodes are emptied.
1739 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1740 struct btrfs_path
*path
, int level
, int slot
)
1742 struct btrfs_node
*node
;
1743 struct buffer_head
*parent
= path
->nodes
[level
];
1748 node
= btrfs_buffer_node(parent
);
1749 nritems
= btrfs_header_nritems(&node
->header
);
1750 if (slot
!= nritems
-1) {
1751 btrfs_memmove(root
, node
, node
->ptrs
+ slot
,
1752 node
->ptrs
+ slot
+ 1,
1753 sizeof(struct btrfs_key_ptr
) *
1754 (nritems
- slot
- 1));
1757 btrfs_set_header_nritems(&node
->header
, nritems
);
1758 if (nritems
== 0 && parent
== root
->node
) {
1759 struct btrfs_header
*header
= btrfs_buffer_header(root
->node
);
1760 BUG_ON(btrfs_header_level(header
) != 1);
1761 /* just turn the root into a leaf and break */
1762 btrfs_set_header_level(header
, 0);
1763 } else if (slot
== 0) {
1764 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1769 btrfs_mark_buffer_dirty(parent
);
1774 * delete the item at the leaf level in path. If that empties
1775 * the leaf, remove it from the tree
1777 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1778 struct btrfs_path
*path
)
1781 struct btrfs_leaf
*leaf
;
1782 struct buffer_head
*leaf_buf
;
1789 leaf_buf
= path
->nodes
[0];
1790 leaf
= btrfs_buffer_leaf(leaf_buf
);
1791 slot
= path
->slots
[0];
1792 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1793 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1794 nritems
= btrfs_header_nritems(&leaf
->header
);
1796 if (slot
!= nritems
- 1) {
1798 int data_end
= leaf_data_end(root
, leaf
);
1799 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1801 btrfs_leaf_data(leaf
) + data_end
,
1803 for (i
= slot
+ 1; i
< nritems
; i
++) {
1804 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1805 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1807 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
,
1808 leaf
->items
+ slot
+ 1,
1809 sizeof(struct btrfs_item
) *
1810 (nritems
- slot
- 1));
1812 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1814 /* delete the leaf if we've emptied it */
1816 if (leaf_buf
== root
->node
) {
1817 btrfs_set_header_level(&leaf
->header
, 0);
1819 clean_tree_block(trans
, root
, leaf_buf
);
1820 wait_on_buffer(leaf_buf
);
1821 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1824 wret
= btrfs_free_extent(trans
, root
,
1825 bh_blocknr(leaf_buf
), 1, 1);
1830 int used
= leaf_space_used(leaf
, 0, nritems
);
1832 wret
= fixup_low_keys(trans
, root
, path
,
1833 &leaf
->items
[0].key
, 1);
1838 /* delete the leaf if it is mostly empty */
1839 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1840 /* push_leaf_left fixes the path.
1841 * make sure the path still points to our leaf
1842 * for possible call to del_ptr below
1844 slot
= path
->slots
[1];
1846 wret
= push_leaf_left(trans
, root
, path
, 1);
1847 if (wret
< 0 && wret
!= -ENOSPC
)
1849 if (path
->nodes
[0] == leaf_buf
&&
1850 btrfs_header_nritems(&leaf
->header
)) {
1851 wret
= push_leaf_right(trans
, root
, path
, 1);
1852 if (wret
< 0 && wret
!= -ENOSPC
)
1855 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1856 u64 blocknr
= bh_blocknr(leaf_buf
);
1857 clean_tree_block(trans
, root
, leaf_buf
);
1858 wait_on_buffer(leaf_buf
);
1859 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1862 btrfs_block_release(root
, leaf_buf
);
1863 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1868 btrfs_mark_buffer_dirty(leaf_buf
);
1869 btrfs_block_release(root
, leaf_buf
);
1872 btrfs_mark_buffer_dirty(leaf_buf
);
1879 * walk up the tree as far as required to find the next leaf.
1880 * returns 0 if it found something or 1 if there are no greater leaves.
1881 * returns < 0 on io errors.
1883 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1888 struct buffer_head
*c
;
1889 struct btrfs_node
*c_node
;
1890 struct buffer_head
*next
= NULL
;
1892 while(level
< BTRFS_MAX_LEVEL
) {
1893 if (!path
->nodes
[level
])
1895 slot
= path
->slots
[level
] + 1;
1896 c
= path
->nodes
[level
];
1897 c_node
= btrfs_buffer_node(c
);
1898 if (slot
>= btrfs_header_nritems(&c_node
->header
)) {
1902 blocknr
= btrfs_node_blockptr(c_node
, slot
);
1904 btrfs_block_release(root
, next
);
1905 next
= read_tree_block(root
, blocknr
);
1908 path
->slots
[level
] = slot
;
1911 c
= path
->nodes
[level
];
1912 btrfs_block_release(root
, c
);
1913 path
->nodes
[level
] = next
;
1914 path
->slots
[level
] = 0;
1917 next
= read_tree_block(root
,
1918 btrfs_node_blockptr(btrfs_buffer_node(next
), 0));
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