2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
21 #include "transaction.h"
23 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
24 *root
, struct btrfs_path
*path
, int level
);
25 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
26 *root
, struct btrfs_key
*ins_key
,
27 struct btrfs_path
*path
, int data_size
);
28 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
29 *root
, struct buffer_head
*dst
, struct buffer_head
31 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
32 btrfs_root
*root
, struct buffer_head
*dst_buf
,
33 struct buffer_head
*src_buf
);
34 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
35 struct btrfs_path
*path
, int level
, int slot
);
37 inline void btrfs_init_path(struct btrfs_path
*p
)
39 memset(p
, 0, sizeof(*p
));
42 struct btrfs_path
*btrfs_alloc_path(void)
44 struct btrfs_path
*path
;
45 path
= kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
47 btrfs_init_path(path
);
51 void btrfs_free_path(struct btrfs_path
*p
)
53 btrfs_release_path(NULL
, p
);
54 kmem_cache_free(btrfs_path_cachep
, p
);
57 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
60 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
63 btrfs_block_release(root
, p
->nodes
[i
]);
65 memset(p
, 0, sizeof(*p
));
68 static int __btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
69 *root
, struct buffer_head
*buf
, struct buffer_head
70 *parent
, int parent_slot
, struct buffer_head
71 **cow_ret
, u64 search_start
, u64 empty_size
)
73 struct buffer_head
*cow
;
74 struct btrfs_node
*cow_node
;
76 int different_trans
= 0;
78 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
79 WARN_ON(!buffer_uptodate(buf
));
80 cow
= btrfs_alloc_free_block(trans
, root
, search_start
, empty_size
);
84 cow_node
= btrfs_buffer_node(cow
);
85 if (buf
->b_size
!= root
->blocksize
|| cow
->b_size
!= root
->blocksize
)
88 memcpy(cow_node
, btrfs_buffer_node(buf
), root
->blocksize
);
89 btrfs_set_header_blocknr(&cow_node
->header
, bh_blocknr(cow
));
90 btrfs_set_header_generation(&cow_node
->header
, trans
->transid
);
91 btrfs_set_header_owner(&cow_node
->header
, root
->root_key
.objectid
);
93 WARN_ON(btrfs_header_generation(btrfs_buffer_header(buf
)) >
95 if (btrfs_header_generation(btrfs_buffer_header(buf
)) !=
98 ret
= btrfs_inc_ref(trans
, root
, buf
);
102 WARN_ON(!root
->ref_cows
);
103 clean_tree_block(trans
, root
, buf
);
106 if (buf
== root
->node
) {
109 if (buf
!= root
->commit_root
) {
110 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
112 btrfs_block_release(root
, buf
);
114 btrfs_set_node_blockptr(btrfs_buffer_node(parent
), parent_slot
,
116 btrfs_mark_buffer_dirty(parent
);
117 WARN_ON(btrfs_header_generation(btrfs_buffer_header(parent
)) !=
119 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
121 btrfs_block_release(root
, buf
);
122 btrfs_mark_buffer_dirty(cow
);
127 int btrfs_cow_block(struct btrfs_trans_handle
*trans
, struct btrfs_root
128 *root
, struct buffer_head
*buf
, struct buffer_head
129 *parent
, int parent_slot
, struct buffer_head
133 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
134 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
135 root
->fs_info
->running_transaction
->transid
);
138 if (trans
->transid
!= root
->fs_info
->generation
) {
139 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
140 root
->fs_info
->generation
);
143 if (btrfs_header_generation(btrfs_buffer_header(buf
)) ==
149 search_start
= bh_blocknr(buf
) & ~((u64
)65535);
150 return __btrfs_cow_block(trans
, root
, buf
, parent
,
151 parent_slot
, cow_ret
, search_start
, 0);
154 static int close_blocks(u64 blocknr
, u64 other
)
156 if (blocknr
< other
&& other
- blocknr
< 8)
158 if (blocknr
> other
&& blocknr
- other
< 8)
163 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
164 struct btrfs_root
*root
, struct buffer_head
*parent
,
167 struct btrfs_node
*parent_node
;
168 struct buffer_head
*cur_bh
;
169 struct buffer_head
*tmp_bh
;
171 u64 search_start
= 0;
179 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
180 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
181 root
->fs_info
->running_transaction
->transid
);
184 if (trans
->transid
!= root
->fs_info
->generation
) {
185 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
186 root
->fs_info
->generation
);
189 parent_node
= btrfs_buffer_node(parent
);
190 parent_nritems
= btrfs_header_nritems(&parent_node
->header
);
193 end_slot
= parent_nritems
;
195 if (parent_nritems
== 1)
198 for (i
= start_slot
; i
< end_slot
; i
++) {
200 blocknr
= btrfs_node_blockptr(parent_node
, i
);
202 other
= btrfs_node_blockptr(parent_node
, i
- 1);
203 close
= close_blocks(blocknr
, other
);
205 if (close
&& i
< end_slot
- 1) {
206 other
= btrfs_node_blockptr(parent_node
, i
+ 1);
207 close
= close_blocks(blocknr
, other
);
212 cur_bh
= btrfs_find_tree_block(root
, blocknr
);
213 if (!cur_bh
|| !buffer_uptodate(cur_bh
) ||
214 buffer_locked(cur_bh
)) {
220 cur_bh
= read_tree_block(root
, blocknr
);
222 if (search_start
== 0) {
223 search_start
= bh_blocknr(cur_bh
) & ~((u64
)65535);
225 err
= __btrfs_cow_block(trans
, root
, cur_bh
, parent
, i
,
226 &tmp_bh
, search_start
,
227 min(8, end_slot
- i
));
230 search_start
= bh_blocknr(tmp_bh
);
237 * The leaf data grows from end-to-front in the node.
238 * this returns the address of the start of the last item,
239 * which is the stop of the leaf data stack
241 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
242 struct btrfs_leaf
*leaf
)
244 u32 nr
= btrfs_header_nritems(&leaf
->header
);
246 return BTRFS_LEAF_DATA_SIZE(root
);
247 return btrfs_item_offset(leaf
->items
+ nr
- 1);
251 * compare two keys in a memcmp fashion
253 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
257 btrfs_disk_key_to_cpu(&k1
, disk
);
259 if (k1
.objectid
> k2
->objectid
)
261 if (k1
.objectid
< k2
->objectid
)
263 if (k1
.flags
> k2
->flags
)
265 if (k1
.flags
< k2
->flags
)
267 if (k1
.offset
> k2
->offset
)
269 if (k1
.offset
< k2
->offset
)
274 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
277 struct btrfs_node
*parent
= NULL
;
278 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
281 struct btrfs_key cpukey
;
282 u32 nritems
= btrfs_header_nritems(&node
->header
);
284 if (path
->nodes
[level
+ 1])
285 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
287 slot
= path
->slots
[level
];
288 BUG_ON(nritems
== 0);
290 struct btrfs_disk_key
*parent_key
;
292 parent_slot
= path
->slots
[level
+ 1];
293 parent_key
= &parent
->ptrs
[parent_slot
].key
;
294 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
295 sizeof(struct btrfs_disk_key
)));
296 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
297 btrfs_header_blocknr(&node
->header
));
299 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
301 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
- 1].key
);
302 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) <= 0);
304 if (slot
< nritems
- 1) {
305 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
+ 1].key
);
306 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) >= 0);
311 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
314 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[level
]);
315 struct btrfs_node
*parent
= NULL
;
317 int slot
= path
->slots
[0];
318 struct btrfs_key cpukey
;
320 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
322 if (path
->nodes
[level
+ 1])
323 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
325 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
331 struct btrfs_disk_key
*parent_key
;
333 parent_slot
= path
->slots
[level
+ 1];
334 parent_key
= &parent
->ptrs
[parent_slot
].key
;
336 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
337 sizeof(struct btrfs_disk_key
)));
338 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
339 btrfs_header_blocknr(&leaf
->header
));
342 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
- 1].key
);
343 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) <= 0);
344 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
- 1) !=
345 btrfs_item_end(leaf
->items
+ slot
));
347 if (slot
< nritems
- 1) {
348 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
+ 1].key
);
349 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) >= 0);
350 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
) !=
351 btrfs_item_end(leaf
->items
+ slot
+ 1));
353 BUG_ON(btrfs_item_offset(leaf
->items
) +
354 btrfs_item_size(leaf
->items
) != BTRFS_LEAF_DATA_SIZE(root
));
358 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
361 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
362 if (memcmp(node
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
363 sizeof(node
->header
.fsid
)))
366 return check_leaf(root
, path
, level
);
367 return check_node(root
, path
, level
);
371 * search for key in the array p. items p are item_size apart
372 * and there are 'max' items in p
373 * the slot in the array is returned via slot, and it points to
374 * the place where you would insert key if it is not found in
377 * slot may point to max if the key is bigger than all of the keys
379 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
386 struct btrfs_disk_key
*tmp
;
389 mid
= (low
+ high
) / 2;
390 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
391 ret
= comp_keys(tmp
, key
);
407 * simple bin_search frontend that does the right thing for
410 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
412 if (btrfs_is_leaf(c
)) {
413 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
414 return generic_bin_search((void *)l
->items
,
415 sizeof(struct btrfs_item
),
416 key
, btrfs_header_nritems(&c
->header
),
419 return generic_bin_search((void *)c
->ptrs
,
420 sizeof(struct btrfs_key_ptr
),
421 key
, btrfs_header_nritems(&c
->header
),
427 static struct buffer_head
*read_node_slot(struct btrfs_root
*root
,
428 struct buffer_head
*parent_buf
,
431 struct btrfs_node
*node
= btrfs_buffer_node(parent_buf
);
434 if (slot
>= btrfs_header_nritems(&node
->header
))
436 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
439 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
440 *root
, struct btrfs_path
*path
, int level
)
442 struct buffer_head
*right_buf
;
443 struct buffer_head
*mid_buf
;
444 struct buffer_head
*left_buf
;
445 struct buffer_head
*parent_buf
= NULL
;
446 struct btrfs_node
*right
= NULL
;
447 struct btrfs_node
*mid
;
448 struct btrfs_node
*left
= NULL
;
449 struct btrfs_node
*parent
= NULL
;
453 int orig_slot
= path
->slots
[level
];
454 int err_on_enospc
= 0;
460 mid_buf
= path
->nodes
[level
];
461 mid
= btrfs_buffer_node(mid_buf
);
462 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
464 if (level
< BTRFS_MAX_LEVEL
- 1)
465 parent_buf
= path
->nodes
[level
+ 1];
466 pslot
= path
->slots
[level
+ 1];
469 * deal with the case where there is only one pointer in the root
470 * by promoting the node below to a root
473 struct buffer_head
*child
;
474 u64 blocknr
= bh_blocknr(mid_buf
);
476 if (btrfs_header_nritems(&mid
->header
) != 1)
479 /* promote the child to a root */
480 child
= read_node_slot(root
, mid_buf
, 0);
483 path
->nodes
[level
] = NULL
;
484 clean_tree_block(trans
, root
, mid_buf
);
485 wait_on_buffer(mid_buf
);
486 /* once for the path */
487 btrfs_block_release(root
, mid_buf
);
488 /* once for the root ptr */
489 btrfs_block_release(root
, mid_buf
);
490 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
492 parent
= btrfs_buffer_node(parent_buf
);
494 if (btrfs_header_nritems(&mid
->header
) >
495 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
498 if (btrfs_header_nritems(&mid
->header
) < 2)
501 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
502 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
504 /* first, try to make some room in the middle buffer */
506 wret
= btrfs_cow_block(trans
, root
, left_buf
,
507 parent_buf
, pslot
- 1, &left_buf
);
512 left
= btrfs_buffer_node(left_buf
);
513 orig_slot
+= btrfs_header_nritems(&left
->header
);
514 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
517 if (btrfs_header_nritems(&mid
->header
) < 2)
522 * then try to empty the right most buffer into the middle
525 wret
= btrfs_cow_block(trans
, root
, right_buf
,
526 parent_buf
, pslot
+ 1, &right_buf
);
532 right
= btrfs_buffer_node(right_buf
);
533 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
534 if (wret
< 0 && wret
!= -ENOSPC
)
536 if (btrfs_header_nritems(&right
->header
) == 0) {
537 u64 blocknr
= bh_blocknr(right_buf
);
538 clean_tree_block(trans
, root
, right_buf
);
539 wait_on_buffer(right_buf
);
540 btrfs_block_release(root
, right_buf
);
543 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
547 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
551 btrfs_memcpy(root
, parent
,
552 &parent
->ptrs
[pslot
+ 1].key
,
554 sizeof(struct btrfs_disk_key
));
555 btrfs_mark_buffer_dirty(parent_buf
);
558 if (btrfs_header_nritems(&mid
->header
) == 1) {
560 * we're not allowed to leave a node with one item in the
561 * tree during a delete. A deletion from lower in the tree
562 * could try to delete the only pointer in this node.
563 * So, pull some keys from the left.
564 * There has to be a left pointer at this point because
565 * otherwise we would have pulled some pointers from the
569 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
576 if (btrfs_header_nritems(&mid
->header
) == 0) {
577 /* we've managed to empty the middle node, drop it */
578 u64 blocknr
= bh_blocknr(mid_buf
);
579 clean_tree_block(trans
, root
, mid_buf
);
580 wait_on_buffer(mid_buf
);
581 btrfs_block_release(root
, mid_buf
);
584 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
587 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
591 /* update the parent key to reflect our changes */
592 btrfs_memcpy(root
, parent
,
593 &parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
594 sizeof(struct btrfs_disk_key
));
595 btrfs_mark_buffer_dirty(parent_buf
);
598 /* update the path */
600 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
602 path
->nodes
[level
] = left_buf
;
603 path
->slots
[level
+ 1] -= 1;
604 path
->slots
[level
] = orig_slot
;
606 btrfs_block_release(root
, mid_buf
);
608 orig_slot
-= btrfs_header_nritems(&left
->header
);
609 path
->slots
[level
] = orig_slot
;
612 /* double check we haven't messed things up */
613 check_block(root
, path
, level
);
615 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[level
]),
620 btrfs_block_release(root
, right_buf
);
622 btrfs_block_release(root
, left_buf
);
626 /* returns zero if the push worked, non-zero otherwise */
627 static int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
628 struct btrfs_root
*root
,
629 struct btrfs_path
*path
, int level
)
631 struct buffer_head
*right_buf
;
632 struct buffer_head
*mid_buf
;
633 struct buffer_head
*left_buf
;
634 struct buffer_head
*parent_buf
= NULL
;
635 struct btrfs_node
*right
= NULL
;
636 struct btrfs_node
*mid
;
637 struct btrfs_node
*left
= NULL
;
638 struct btrfs_node
*parent
= NULL
;
642 int orig_slot
= path
->slots
[level
];
648 mid_buf
= path
->nodes
[level
];
649 mid
= btrfs_buffer_node(mid_buf
);
650 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
652 if (level
< BTRFS_MAX_LEVEL
- 1)
653 parent_buf
= path
->nodes
[level
+ 1];
654 pslot
= path
->slots
[level
+ 1];
658 parent
= btrfs_buffer_node(parent_buf
);
660 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
662 /* first, try to make some room in the middle buffer */
665 left
= btrfs_buffer_node(left_buf
);
666 left_nr
= btrfs_header_nritems(&left
->header
);
667 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
670 ret
= btrfs_cow_block(trans
, root
, left_buf
, parent_buf
,
671 pslot
- 1, &left_buf
);
675 left
= btrfs_buffer_node(left_buf
);
676 wret
= push_node_left(trans
, root
,
683 orig_slot
+= left_nr
;
684 btrfs_memcpy(root
, parent
,
685 &parent
->ptrs
[pslot
].key
,
687 sizeof(struct btrfs_disk_key
));
688 btrfs_mark_buffer_dirty(parent_buf
);
689 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
690 path
->nodes
[level
] = left_buf
;
691 path
->slots
[level
+ 1] -= 1;
692 path
->slots
[level
] = orig_slot
;
693 btrfs_block_release(root
, mid_buf
);
696 btrfs_header_nritems(&left
->header
);
697 path
->slots
[level
] = orig_slot
;
698 btrfs_block_release(root
, left_buf
);
700 check_node(root
, path
, level
);
703 btrfs_block_release(root
, left_buf
);
705 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
708 * then try to empty the right most buffer into the middle
712 right
= btrfs_buffer_node(right_buf
);
713 right_nr
= btrfs_header_nritems(&right
->header
);
714 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
717 ret
= btrfs_cow_block(trans
, root
, right_buf
,
718 parent_buf
, pslot
+ 1,
723 right
= btrfs_buffer_node(right_buf
);
724 wret
= balance_node_right(trans
, root
,
731 btrfs_memcpy(root
, parent
,
732 &parent
->ptrs
[pslot
+ 1].key
,
734 sizeof(struct btrfs_disk_key
));
735 btrfs_mark_buffer_dirty(parent_buf
);
736 if (btrfs_header_nritems(&mid
->header
) <= orig_slot
) {
737 path
->nodes
[level
] = right_buf
;
738 path
->slots
[level
+ 1] += 1;
739 path
->slots
[level
] = orig_slot
-
740 btrfs_header_nritems(&mid
->header
);
741 btrfs_block_release(root
, mid_buf
);
743 btrfs_block_release(root
, right_buf
);
745 check_node(root
, path
, level
);
748 btrfs_block_release(root
, right_buf
);
750 check_node(root
, path
, level
);
755 * readahead one full node of leaves
757 static void reada_for_search(struct btrfs_root
*root
, struct btrfs_path
*path
,
760 struct btrfs_node
*node
;
769 int direction
= path
->reada
;
770 struct radix_tree_root found
;
771 unsigned long gang
[8];
772 struct buffer_head
*bh
;
777 if (!path
->nodes
[level
])
780 node
= btrfs_buffer_node(path
->nodes
[level
]);
781 search
= btrfs_node_blockptr(node
, slot
);
782 bh
= btrfs_find_tree_block(root
, search
);
788 init_bit_radix(&found
);
789 nritems
= btrfs_header_nritems(&node
->header
);
790 for (i
= slot
; i
< nritems
; i
++) {
791 item_objectid
= btrfs_disk_key_objectid(&node
->ptrs
[i
].key
);
792 blocknr
= btrfs_node_blockptr(node
, i
);
793 set_radix_bit(&found
, blocknr
);
796 cluster_start
= search
- 4;
797 if (cluster_start
> search
)
800 cluster_start
= search
+ 4;
802 ret
= find_first_radix_bit(&found
, gang
, 0, ARRAY_SIZE(gang
));
805 for (i
= 0; i
< ret
; i
++) {
807 clear_radix_bit(&found
, blocknr
);
810 if (direction
> 0 && cluster_start
<= blocknr
&&
811 cluster_start
+ 8 > blocknr
) {
812 cluster_start
= blocknr
;
813 readahead_tree_block(root
, blocknr
);
815 } else if (direction
< 0 && cluster_start
>= blocknr
&&
816 blocknr
+ 8 > cluster_start
) {
817 cluster_start
= blocknr
;
818 readahead_tree_block(root
, blocknr
);
825 * look for key in the tree. path is filled in with nodes along the way
826 * if key is found, we return zero and you can find the item in the leaf
827 * level of the path (level 0)
829 * If the key isn't found, the path points to the slot where it should
830 * be inserted, and 1 is returned. If there are other errors during the
831 * search a negative error number is returned.
833 * if ins_len > 0, nodes and leaves will be split as we walk down the
834 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
837 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
838 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
841 struct buffer_head
*b
;
842 struct buffer_head
*cow_buf
;
843 struct btrfs_node
*c
;
848 int should_reada
= p
->reada
;
851 lowest_level
= p
->lowest_level
;
852 WARN_ON(lowest_level
&& ins_len
);
853 WARN_ON(p
->nodes
[0] != NULL
);
854 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
859 c
= btrfs_buffer_node(b
);
860 level
= btrfs_header_level(&c
->header
);
863 wret
= btrfs_cow_block(trans
, root
, b
,
868 btrfs_block_release(root
, cow_buf
);
872 c
= btrfs_buffer_node(b
);
874 BUG_ON(!cow
&& ins_len
);
875 if (level
!= btrfs_header_level(&c
->header
))
877 level
= btrfs_header_level(&c
->header
);
879 ret
= check_block(root
, p
, level
);
882 ret
= bin_search(c
, key
, &slot
);
883 if (!btrfs_is_leaf(c
)) {
886 p
->slots
[level
] = slot
;
887 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) >=
888 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
889 int sret
= split_node(trans
, root
, p
, level
);
894 c
= btrfs_buffer_node(b
);
895 slot
= p
->slots
[level
];
896 } else if (ins_len
< 0) {
897 int sret
= balance_level(trans
, root
, p
,
904 c
= btrfs_buffer_node(b
);
905 slot
= p
->slots
[level
];
906 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
908 /* this is only true while dropping a snapshot */
909 if (level
== lowest_level
)
911 blocknr
= btrfs_node_blockptr(c
, slot
);
913 reada_for_search(root
, p
, level
, slot
);
914 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
917 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
918 p
->slots
[level
] = slot
;
919 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
920 sizeof(struct btrfs_item
) + ins_len
) {
921 int sret
= split_leaf(trans
, root
, key
,
934 * adjust the pointers going up the tree, starting at level
935 * making sure the right key of each node is points to 'key'.
936 * This is used after shifting pointers to the left, so it stops
937 * fixing up pointers when a given leaf/node is not in slot 0 of the
940 * If this fails to write a tree block, it returns -1, but continues
941 * fixing up the blocks in ram so the tree is consistent.
943 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
944 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
949 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
950 struct btrfs_node
*t
;
951 int tslot
= path
->slots
[i
];
954 t
= btrfs_buffer_node(path
->nodes
[i
]);
955 btrfs_memcpy(root
, t
, &t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
956 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
964 * try to push data from one node into the next node left in the
967 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
968 * error, and > 0 if there was no room in the left hand block.
970 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
971 *root
, struct buffer_head
*dst_buf
, struct
972 buffer_head
*src_buf
)
974 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
975 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
981 src_nritems
= btrfs_header_nritems(&src
->header
);
982 dst_nritems
= btrfs_header_nritems(&dst
->header
);
983 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
985 if (push_items
<= 0) {
989 if (src_nritems
< push_items
)
990 push_items
= src_nritems
;
992 btrfs_memcpy(root
, dst
, dst
->ptrs
+ dst_nritems
, src
->ptrs
,
993 push_items
* sizeof(struct btrfs_key_ptr
));
994 if (push_items
< src_nritems
) {
995 btrfs_memmove(root
, src
, src
->ptrs
, src
->ptrs
+ push_items
,
996 (src_nritems
- push_items
) *
997 sizeof(struct btrfs_key_ptr
));
999 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
1000 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
1001 btrfs_mark_buffer_dirty(src_buf
);
1002 btrfs_mark_buffer_dirty(dst_buf
);
1007 * try to push data from one node into the next node right in the
1010 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1011 * error, and > 0 if there was no room in the right hand block.
1013 * this will only push up to 1/2 the contents of the left node over
1015 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
1016 btrfs_root
*root
, struct buffer_head
*dst_buf
,
1017 struct buffer_head
*src_buf
)
1019 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
1020 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
1027 src_nritems
= btrfs_header_nritems(&src
->header
);
1028 dst_nritems
= btrfs_header_nritems(&dst
->header
);
1029 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1030 if (push_items
<= 0) {
1034 max_push
= src_nritems
/ 2 + 1;
1035 /* don't try to empty the node */
1036 if (max_push
> src_nritems
)
1038 if (max_push
< push_items
)
1039 push_items
= max_push
;
1041 btrfs_memmove(root
, dst
, dst
->ptrs
+ push_items
, dst
->ptrs
,
1042 dst_nritems
* sizeof(struct btrfs_key_ptr
));
1044 btrfs_memcpy(root
, dst
, dst
->ptrs
,
1045 src
->ptrs
+ src_nritems
- push_items
,
1046 push_items
* sizeof(struct btrfs_key_ptr
));
1048 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
1049 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
1051 btrfs_mark_buffer_dirty(src_buf
);
1052 btrfs_mark_buffer_dirty(dst_buf
);
1057 * helper function to insert a new root level in the tree.
1058 * A new node is allocated, and a single item is inserted to
1059 * point to the existing root
1061 * returns zero on success or < 0 on failure.
1063 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
1064 *root
, struct btrfs_path
*path
, int level
)
1066 struct buffer_head
*t
;
1067 struct btrfs_node
*lower
;
1068 struct btrfs_node
*c
;
1069 struct btrfs_disk_key
*lower_key
;
1071 BUG_ON(path
->nodes
[level
]);
1072 BUG_ON(path
->nodes
[level
-1] != root
->node
);
1074 t
= btrfs_alloc_free_block(trans
, root
, root
->node
->b_blocknr
, 0);
1077 c
= btrfs_buffer_node(t
);
1078 memset(c
, 0, root
->blocksize
);
1079 btrfs_set_header_nritems(&c
->header
, 1);
1080 btrfs_set_header_level(&c
->header
, level
);
1081 btrfs_set_header_blocknr(&c
->header
, bh_blocknr(t
));
1082 btrfs_set_header_generation(&c
->header
, trans
->transid
);
1083 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
1084 lower
= btrfs_buffer_node(path
->nodes
[level
-1]);
1085 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1086 sizeof(c
->header
.fsid
));
1087 if (btrfs_is_leaf(lower
))
1088 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
1090 lower_key
= &lower
->ptrs
[0].key
;
1091 btrfs_memcpy(root
, c
, &c
->ptrs
[0].key
, lower_key
,
1092 sizeof(struct btrfs_disk_key
));
1093 btrfs_set_node_blockptr(c
, 0, bh_blocknr(path
->nodes
[level
- 1]));
1095 btrfs_mark_buffer_dirty(t
);
1097 /* the super has an extra ref to root->node */
1098 btrfs_block_release(root
, root
->node
);
1101 path
->nodes
[level
] = t
;
1102 path
->slots
[level
] = 0;
1107 * worker function to insert a single pointer in a node.
1108 * the node should have enough room for the pointer already
1110 * slot and level indicate where you want the key to go, and
1111 * blocknr is the block the key points to.
1113 * returns zero on success and < 0 on any error
1115 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
1116 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
1117 *key
, u64 blocknr
, int slot
, int level
)
1119 struct btrfs_node
*lower
;
1122 BUG_ON(!path
->nodes
[level
]);
1123 lower
= btrfs_buffer_node(path
->nodes
[level
]);
1124 nritems
= btrfs_header_nritems(&lower
->header
);
1127 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
1129 if (slot
!= nritems
) {
1130 btrfs_memmove(root
, lower
, lower
->ptrs
+ slot
+ 1,
1132 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
1134 btrfs_memcpy(root
, lower
, &lower
->ptrs
[slot
].key
,
1135 key
, sizeof(struct btrfs_disk_key
));
1136 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
1137 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
1138 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1139 check_node(root
, path
, level
);
1144 * split the node at the specified level in path in two.
1145 * The path is corrected to point to the appropriate node after the split
1147 * Before splitting this tries to make some room in the node by pushing
1148 * left and right, if either one works, it returns right away.
1150 * returns 0 on success and < 0 on failure
1152 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
1153 *root
, struct btrfs_path
*path
, int level
)
1155 struct buffer_head
*t
;
1156 struct btrfs_node
*c
;
1157 struct buffer_head
*split_buffer
;
1158 struct btrfs_node
*split
;
1164 t
= path
->nodes
[level
];
1165 c
= btrfs_buffer_node(t
);
1166 if (t
== root
->node
) {
1167 /* trying to split the root, lets make a new one */
1168 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
1172 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
1173 t
= path
->nodes
[level
];
1174 c
= btrfs_buffer_node(t
);
1176 btrfs_header_nritems(&c
->header
) <
1177 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1)
1183 c_nritems
= btrfs_header_nritems(&c
->header
);
1184 split_buffer
= btrfs_alloc_free_block(trans
, root
, t
->b_blocknr
, 0);
1185 if (IS_ERR(split_buffer
))
1186 return PTR_ERR(split_buffer
);
1188 split
= btrfs_buffer_node(split_buffer
);
1189 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
1190 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
1191 btrfs_set_header_blocknr(&split
->header
, bh_blocknr(split_buffer
));
1192 btrfs_set_header_generation(&split
->header
, trans
->transid
);
1193 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
1194 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1195 sizeof(split
->header
.fsid
));
1196 mid
= (c_nritems
+ 1) / 2;
1197 btrfs_memcpy(root
, split
, split
->ptrs
, c
->ptrs
+ mid
,
1198 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
1199 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
1200 btrfs_set_header_nritems(&c
->header
, mid
);
1203 btrfs_mark_buffer_dirty(t
);
1204 btrfs_mark_buffer_dirty(split_buffer
);
1205 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
1206 bh_blocknr(split_buffer
), path
->slots
[level
+ 1] + 1,
1211 if (path
->slots
[level
] >= mid
) {
1212 path
->slots
[level
] -= mid
;
1213 btrfs_block_release(root
, t
);
1214 path
->nodes
[level
] = split_buffer
;
1215 path
->slots
[level
+ 1] += 1;
1217 btrfs_block_release(root
, split_buffer
);
1223 * how many bytes are required to store the items in a leaf. start
1224 * and nr indicate which items in the leaf to check. This totals up the
1225 * space used both by the item structs and the item data
1227 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
1230 int nritems
= btrfs_header_nritems(&l
->header
);
1231 int end
= min(nritems
, start
+ nr
) - 1;
1235 data_len
= btrfs_item_end(l
->items
+ start
);
1236 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
1237 data_len
+= sizeof(struct btrfs_item
) * nr
;
1238 WARN_ON(data_len
< 0);
1243 * The space between the end of the leaf items and
1244 * the start of the leaf data. IOW, how much room
1245 * the leaf has left for both items and data
1247 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
1249 int nritems
= btrfs_header_nritems(&leaf
->header
);
1250 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
1254 * push some data in the path leaf to the right, trying to free up at
1255 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1257 * returns 1 if the push failed because the other node didn't have enough
1258 * room, 0 if everything worked out and < 0 if there were major errors.
1260 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
1261 *root
, struct btrfs_path
*path
, int data_size
)
1263 struct buffer_head
*left_buf
= path
->nodes
[0];
1264 struct btrfs_leaf
*left
= btrfs_buffer_leaf(left_buf
);
1265 struct btrfs_leaf
*right
;
1266 struct buffer_head
*right_buf
;
1267 struct buffer_head
*upper
;
1268 struct btrfs_node
*upper_node
;
1274 struct btrfs_item
*item
;
1279 slot
= path
->slots
[1];
1280 if (!path
->nodes
[1]) {
1283 upper
= path
->nodes
[1];
1284 upper_node
= btrfs_buffer_node(upper
);
1285 if (slot
>= btrfs_header_nritems(&upper_node
->header
) - 1) {
1288 right_buf
= read_tree_block(root
,
1289 btrfs_node_blockptr(btrfs_buffer_node(upper
), slot
+ 1));
1290 right
= btrfs_buffer_leaf(right_buf
);
1291 free_space
= btrfs_leaf_free_space(root
, right
);
1292 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1293 btrfs_block_release(root
, right_buf
);
1296 /* cow and double check */
1297 ret
= btrfs_cow_block(trans
, root
, right_buf
, upper
,
1298 slot
+ 1, &right_buf
);
1300 btrfs_block_release(root
, right_buf
);
1303 right
= btrfs_buffer_leaf(right_buf
);
1304 free_space
= btrfs_leaf_free_space(root
, right
);
1305 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1306 btrfs_block_release(root
, right_buf
);
1310 left_nritems
= btrfs_header_nritems(&left
->header
);
1311 if (left_nritems
== 0) {
1312 btrfs_block_release(root
, right_buf
);
1315 for (i
= left_nritems
- 1; i
>= 1; i
--) {
1316 item
= left
->items
+ i
;
1317 if (path
->slots
[0] == i
)
1318 push_space
+= data_size
+ sizeof(*item
);
1319 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1323 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1325 if (push_items
== 0) {
1326 btrfs_block_release(root
, right_buf
);
1329 if (push_items
== left_nritems
)
1331 right_nritems
= btrfs_header_nritems(&right
->header
);
1332 /* push left to right */
1333 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
1334 push_space
-= leaf_data_end(root
, left
);
1335 /* make room in the right data area */
1336 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1337 leaf_data_end(root
, right
) - push_space
,
1338 btrfs_leaf_data(right
) +
1339 leaf_data_end(root
, right
), BTRFS_LEAF_DATA_SIZE(root
) -
1340 leaf_data_end(root
, right
));
1341 /* copy from the left data area */
1342 btrfs_memcpy(root
, right
, btrfs_leaf_data(right
) +
1343 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1344 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1346 btrfs_memmove(root
, right
, right
->items
+ push_items
, right
->items
,
1347 right_nritems
* sizeof(struct btrfs_item
));
1348 /* copy the items from left to right */
1349 btrfs_memcpy(root
, right
, right
->items
, left
->items
+
1350 left_nritems
- push_items
,
1351 push_items
* sizeof(struct btrfs_item
));
1353 /* update the item pointers */
1354 right_nritems
+= push_items
;
1355 btrfs_set_header_nritems(&right
->header
, right_nritems
);
1356 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1357 for (i
= 0; i
< right_nritems
; i
++) {
1358 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1359 btrfs_item_size(right
->items
+ i
));
1360 push_space
= btrfs_item_offset(right
->items
+ i
);
1362 left_nritems
-= push_items
;
1363 btrfs_set_header_nritems(&left
->header
, left_nritems
);
1365 btrfs_mark_buffer_dirty(left_buf
);
1366 btrfs_mark_buffer_dirty(right_buf
);
1368 btrfs_memcpy(root
, upper_node
, &upper_node
->ptrs
[slot
+ 1].key
,
1369 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
1370 btrfs_mark_buffer_dirty(upper
);
1372 /* then fixup the leaf pointer in the path */
1373 if (path
->slots
[0] >= left_nritems
) {
1374 path
->slots
[0] -= left_nritems
;
1375 btrfs_block_release(root
, path
->nodes
[0]);
1376 path
->nodes
[0] = right_buf
;
1377 path
->slots
[1] += 1;
1379 btrfs_block_release(root
, right_buf
);
1382 check_node(root
, path
, 1);
1386 * push some data in the path leaf to the left, trying to free up at
1387 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1389 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1390 *root
, struct btrfs_path
*path
, int data_size
)
1392 struct buffer_head
*right_buf
= path
->nodes
[0];
1393 struct btrfs_leaf
*right
= btrfs_buffer_leaf(right_buf
);
1394 struct buffer_head
*t
;
1395 struct btrfs_leaf
*left
;
1401 struct btrfs_item
*item
;
1402 u32 old_left_nritems
;
1406 slot
= path
->slots
[1];
1410 if (!path
->nodes
[1]) {
1413 t
= read_tree_block(root
,
1414 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[1]), slot
- 1));
1415 left
= btrfs_buffer_leaf(t
);
1416 free_space
= btrfs_leaf_free_space(root
, left
);
1417 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1418 btrfs_block_release(root
, t
);
1422 /* cow and double check */
1423 ret
= btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
1425 /* we hit -ENOSPC, but it isn't fatal here */
1428 left
= btrfs_buffer_leaf(t
);
1429 free_space
= btrfs_leaf_free_space(root
, left
);
1430 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1431 btrfs_block_release(root
, t
);
1435 if (btrfs_header_nritems(&right
->header
) == 0) {
1436 btrfs_block_release(root
, t
);
1440 for (i
= 0; i
< btrfs_header_nritems(&right
->header
) - 1; i
++) {
1441 item
= right
->items
+ i
;
1442 if (path
->slots
[0] == i
)
1443 push_space
+= data_size
+ sizeof(*item
);
1444 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1448 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1450 if (push_items
== 0) {
1451 btrfs_block_release(root
, t
);
1454 if (push_items
== btrfs_header_nritems(&right
->header
))
1456 /* push data from right to left */
1457 btrfs_memcpy(root
, left
, left
->items
+
1458 btrfs_header_nritems(&left
->header
),
1459 right
->items
, push_items
* sizeof(struct btrfs_item
));
1460 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1461 btrfs_item_offset(right
->items
+ push_items
-1);
1462 btrfs_memcpy(root
, left
, btrfs_leaf_data(left
) +
1463 leaf_data_end(root
, left
) - push_space
,
1464 btrfs_leaf_data(right
) +
1465 btrfs_item_offset(right
->items
+ push_items
- 1),
1467 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1468 BUG_ON(old_left_nritems
< 0);
1470 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1471 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1472 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1473 (BTRFS_LEAF_DATA_SIZE(root
) -
1474 btrfs_item_offset(left
->items
+
1475 old_left_nritems
- 1)));
1477 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1479 /* fixup right node */
1480 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1481 leaf_data_end(root
, right
);
1482 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1483 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1484 btrfs_leaf_data(right
) +
1485 leaf_data_end(root
, right
), push_space
);
1486 btrfs_memmove(root
, right
, right
->items
, right
->items
+ push_items
,
1487 (btrfs_header_nritems(&right
->header
) - push_items
) *
1488 sizeof(struct btrfs_item
));
1489 btrfs_set_header_nritems(&right
->header
,
1490 btrfs_header_nritems(&right
->header
) -
1492 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1494 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1495 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1496 btrfs_item_size(right
->items
+ i
));
1497 push_space
= btrfs_item_offset(right
->items
+ i
);
1500 btrfs_mark_buffer_dirty(t
);
1501 btrfs_mark_buffer_dirty(right_buf
);
1503 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1507 /* then fixup the leaf pointer in the path */
1508 if (path
->slots
[0] < push_items
) {
1509 path
->slots
[0] += old_left_nritems
;
1510 btrfs_block_release(root
, path
->nodes
[0]);
1512 path
->slots
[1] -= 1;
1514 btrfs_block_release(root
, t
);
1515 path
->slots
[0] -= push_items
;
1517 BUG_ON(path
->slots
[0] < 0);
1519 check_node(root
, path
, 1);
1524 * split the path's leaf in two, making sure there is at least data_size
1525 * available for the resulting leaf level of the path.
1527 * returns 0 if all went well and < 0 on failure.
1529 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1530 *root
, struct btrfs_key
*ins_key
,
1531 struct btrfs_path
*path
, int data_size
)
1533 struct buffer_head
*l_buf
;
1534 struct btrfs_leaf
*l
;
1538 struct btrfs_leaf
*right
;
1539 struct buffer_head
*right_buffer
;
1540 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1546 int double_split
= 0;
1547 struct btrfs_disk_key disk_key
;
1549 /* first try to make some room by pushing left and right */
1550 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1554 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1558 l_buf
= path
->nodes
[0];
1559 l
= btrfs_buffer_leaf(l_buf
);
1561 /* did the pushes work? */
1562 if (btrfs_leaf_free_space(root
, l
) >=
1563 sizeof(struct btrfs_item
) + data_size
)
1566 if (!path
->nodes
[1]) {
1567 ret
= insert_new_root(trans
, root
, path
, 1);
1571 slot
= path
->slots
[0];
1572 nritems
= btrfs_header_nritems(&l
->header
);
1573 mid
= (nritems
+ 1)/ 2;
1575 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
, 0);
1576 if (IS_ERR(right_buffer
))
1577 return PTR_ERR(right_buffer
);
1579 right
= btrfs_buffer_leaf(right_buffer
);
1580 memset(&right
->header
, 0, sizeof(right
->header
));
1581 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1582 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1583 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1584 btrfs_set_header_level(&right
->header
, 0);
1585 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1586 sizeof(right
->header
.fsid
));
1589 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1590 BTRFS_LEAF_DATA_SIZE(root
)) {
1591 if (slot
>= nritems
) {
1592 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1593 btrfs_set_header_nritems(&right
->header
, 0);
1594 wret
= insert_ptr(trans
, root
, path
,
1596 bh_blocknr(right_buffer
),
1597 path
->slots
[1] + 1, 1);
1600 btrfs_block_release(root
, path
->nodes
[0]);
1601 path
->nodes
[0] = right_buffer
;
1603 path
->slots
[1] += 1;
1610 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1611 BTRFS_LEAF_DATA_SIZE(root
)) {
1613 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1614 btrfs_set_header_nritems(&right
->header
, 0);
1615 wret
= insert_ptr(trans
, root
, path
,
1617 bh_blocknr(right_buffer
),
1621 btrfs_block_release(root
, path
->nodes
[0]);
1622 path
->nodes
[0] = right_buffer
;
1624 if (path
->slots
[1] == 0) {
1625 wret
= fixup_low_keys(trans
, root
,
1626 path
, &disk_key
, 1);
1636 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1637 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1638 leaf_data_end(root
, l
);
1639 btrfs_memcpy(root
, right
, right
->items
, l
->items
+ mid
,
1640 (nritems
- mid
) * sizeof(struct btrfs_item
));
1641 btrfs_memcpy(root
, right
,
1642 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1643 data_copy_size
, btrfs_leaf_data(l
) +
1644 leaf_data_end(root
, l
), data_copy_size
);
1645 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1646 btrfs_item_end(l
->items
+ mid
);
1648 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1649 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1650 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1653 btrfs_set_header_nritems(&l
->header
, mid
);
1655 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1656 bh_blocknr(right_buffer
), path
->slots
[1] + 1, 1);
1659 btrfs_mark_buffer_dirty(right_buffer
);
1660 btrfs_mark_buffer_dirty(l_buf
);
1661 BUG_ON(path
->slots
[0] != slot
);
1663 btrfs_block_release(root
, path
->nodes
[0]);
1664 path
->nodes
[0] = right_buffer
;
1665 path
->slots
[0] -= mid
;
1666 path
->slots
[1] += 1;
1668 btrfs_block_release(root
, right_buffer
);
1669 BUG_ON(path
->slots
[0] < 0);
1670 check_node(root
, path
, 1);
1674 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
, 0);
1675 if (IS_ERR(right_buffer
))
1676 return PTR_ERR(right_buffer
);
1678 right
= btrfs_buffer_leaf(right_buffer
);
1679 memset(&right
->header
, 0, sizeof(right
->header
));
1680 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1681 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1682 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1683 btrfs_set_header_level(&right
->header
, 0);
1684 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1685 sizeof(right
->header
.fsid
));
1686 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1687 btrfs_set_header_nritems(&right
->header
, 0);
1688 wret
= insert_ptr(trans
, root
, path
,
1690 bh_blocknr(right_buffer
),
1694 if (path
->slots
[1] == 0) {
1695 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1699 btrfs_block_release(root
, path
->nodes
[0]);
1700 path
->nodes
[0] = right_buffer
;
1702 check_node(root
, path
, 1);
1703 check_leaf(root
, path
, 0);
1707 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
1708 struct btrfs_root
*root
,
1709 struct btrfs_path
*path
,
1715 struct btrfs_leaf
*leaf
;
1716 struct buffer_head
*leaf_buf
;
1718 unsigned int data_end
;
1719 unsigned int old_data_start
;
1720 unsigned int old_size
;
1721 unsigned int size_diff
;
1724 slot_orig
= path
->slots
[0];
1725 leaf_buf
= path
->nodes
[0];
1726 leaf
= btrfs_buffer_leaf(leaf_buf
);
1728 nritems
= btrfs_header_nritems(&leaf
->header
);
1729 data_end
= leaf_data_end(root
, leaf
);
1731 slot
= path
->slots
[0];
1732 old_data_start
= btrfs_item_offset(leaf
->items
+ slot
);
1733 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1734 BUG_ON(old_size
<= new_size
);
1735 size_diff
= old_size
- new_size
;
1738 BUG_ON(slot
>= nritems
);
1741 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1743 /* first correct the data pointers */
1744 for (i
= slot
; i
< nritems
; i
++) {
1745 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1746 btrfs_set_item_offset(leaf
->items
+ i
,
1749 /* shift the data */
1750 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1751 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
1752 data_end
, old_data_start
+ new_size
- data_end
);
1753 btrfs_set_item_size(leaf
->items
+ slot
, new_size
);
1754 btrfs_mark_buffer_dirty(leaf_buf
);
1757 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1759 check_leaf(root
, path
, 0);
1763 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1764 *root
, struct btrfs_path
*path
, u32 data_size
)
1769 struct btrfs_leaf
*leaf
;
1770 struct buffer_head
*leaf_buf
;
1772 unsigned int data_end
;
1773 unsigned int old_data
;
1774 unsigned int old_size
;
1777 slot_orig
= path
->slots
[0];
1778 leaf_buf
= path
->nodes
[0];
1779 leaf
= btrfs_buffer_leaf(leaf_buf
);
1781 nritems
= btrfs_header_nritems(&leaf
->header
);
1782 data_end
= leaf_data_end(root
, leaf
);
1784 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1786 slot
= path
->slots
[0];
1787 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1790 BUG_ON(slot
>= nritems
);
1793 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1795 /* first correct the data pointers */
1796 for (i
= slot
; i
< nritems
; i
++) {
1797 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1798 btrfs_set_item_offset(leaf
->items
+ i
,
1801 /* shift the data */
1802 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1803 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1804 data_end
, old_data
- data_end
);
1805 data_end
= old_data
;
1806 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1807 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1808 btrfs_mark_buffer_dirty(leaf_buf
);
1811 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1813 check_leaf(root
, path
, 0);
1818 * Given a key and some data, insert an item into the tree.
1819 * This does all the path init required, making room in the tree if needed.
1821 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1822 *root
, struct btrfs_path
*path
, struct btrfs_key
1823 *cpu_key
, u32 data_size
)
1828 struct btrfs_leaf
*leaf
;
1829 struct buffer_head
*leaf_buf
;
1831 unsigned int data_end
;
1832 struct btrfs_disk_key disk_key
;
1834 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1836 /* create a root if there isn't one */
1839 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1846 slot_orig
= path
->slots
[0];
1847 leaf_buf
= path
->nodes
[0];
1848 leaf
= btrfs_buffer_leaf(leaf_buf
);
1850 nritems
= btrfs_header_nritems(&leaf
->header
);
1851 data_end
= leaf_data_end(root
, leaf
);
1853 if (btrfs_leaf_free_space(root
, leaf
) <
1854 sizeof(struct btrfs_item
) + data_size
) {
1857 slot
= path
->slots
[0];
1859 if (slot
!= nritems
) {
1861 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1864 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1866 /* first correct the data pointers */
1867 for (i
= slot
; i
< nritems
; i
++) {
1868 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1869 btrfs_set_item_offset(leaf
->items
+ i
,
1873 /* shift the items */
1874 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
+ 1,
1876 (nritems
- slot
) * sizeof(struct btrfs_item
));
1878 /* shift the data */
1879 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1880 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1881 data_end
, old_data
- data_end
);
1882 data_end
= old_data
;
1884 /* setup the item for the new data */
1885 btrfs_memcpy(root
, leaf
, &leaf
->items
[slot
].key
, &disk_key
,
1886 sizeof(struct btrfs_disk_key
));
1887 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1888 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1889 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1890 btrfs_mark_buffer_dirty(leaf_buf
);
1894 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1896 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1898 check_leaf(root
, path
, 0);
1904 * Given a key and some data, insert an item into the tree.
1905 * This does all the path init required, making room in the tree if needed.
1907 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1908 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1912 struct btrfs_path
*path
;
1915 path
= btrfs_alloc_path();
1917 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
1919 ptr
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]),
1920 path
->slots
[0], u8
);
1921 btrfs_memcpy(root
, path
->nodes
[0]->b_data
,
1922 ptr
, data
, data_size
);
1923 btrfs_mark_buffer_dirty(path
->nodes
[0]);
1925 btrfs_free_path(path
);
1930 * delete the pointer from a given node.
1932 * If the delete empties a node, the node is removed from the tree,
1933 * continuing all the way the root if required. The root is converted into
1934 * a leaf if all the nodes are emptied.
1936 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1937 struct btrfs_path
*path
, int level
, int slot
)
1939 struct btrfs_node
*node
;
1940 struct buffer_head
*parent
= path
->nodes
[level
];
1945 node
= btrfs_buffer_node(parent
);
1946 nritems
= btrfs_header_nritems(&node
->header
);
1947 if (slot
!= nritems
-1) {
1948 btrfs_memmove(root
, node
, node
->ptrs
+ slot
,
1949 node
->ptrs
+ slot
+ 1,
1950 sizeof(struct btrfs_key_ptr
) *
1951 (nritems
- slot
- 1));
1954 btrfs_set_header_nritems(&node
->header
, nritems
);
1955 if (nritems
== 0 && parent
== root
->node
) {
1956 struct btrfs_header
*header
= btrfs_buffer_header(root
->node
);
1957 BUG_ON(btrfs_header_level(header
) != 1);
1958 /* just turn the root into a leaf and break */
1959 btrfs_set_header_level(header
, 0);
1960 } else if (slot
== 0) {
1961 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1966 btrfs_mark_buffer_dirty(parent
);
1971 * delete the item at the leaf level in path. If that empties
1972 * the leaf, remove it from the tree
1974 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1975 struct btrfs_path
*path
)
1978 struct btrfs_leaf
*leaf
;
1979 struct buffer_head
*leaf_buf
;
1986 leaf_buf
= path
->nodes
[0];
1987 leaf
= btrfs_buffer_leaf(leaf_buf
);
1988 slot
= path
->slots
[0];
1989 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1990 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1991 nritems
= btrfs_header_nritems(&leaf
->header
);
1993 if (slot
!= nritems
- 1) {
1995 int data_end
= leaf_data_end(root
, leaf
);
1996 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1998 btrfs_leaf_data(leaf
) + data_end
,
2000 for (i
= slot
+ 1; i
< nritems
; i
++) {
2001 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
2002 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
2004 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
,
2005 leaf
->items
+ slot
+ 1,
2006 sizeof(struct btrfs_item
) *
2007 (nritems
- slot
- 1));
2009 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
2011 /* delete the leaf if we've emptied it */
2013 if (leaf_buf
== root
->node
) {
2014 btrfs_set_header_level(&leaf
->header
, 0);
2016 clean_tree_block(trans
, root
, leaf_buf
);
2017 wait_on_buffer(leaf_buf
);
2018 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
2021 wret
= btrfs_free_extent(trans
, root
,
2022 bh_blocknr(leaf_buf
), 1, 1);
2027 int used
= leaf_space_used(leaf
, 0, nritems
);
2029 wret
= fixup_low_keys(trans
, root
, path
,
2030 &leaf
->items
[0].key
, 1);
2035 /* delete the leaf if it is mostly empty */
2036 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
2037 /* push_leaf_left fixes the path.
2038 * make sure the path still points to our leaf
2039 * for possible call to del_ptr below
2041 slot
= path
->slots
[1];
2043 wret
= push_leaf_left(trans
, root
, path
, 1);
2044 if (wret
< 0 && wret
!= -ENOSPC
)
2046 if (path
->nodes
[0] == leaf_buf
&&
2047 btrfs_header_nritems(&leaf
->header
)) {
2048 wret
= push_leaf_right(trans
, root
, path
, 1);
2049 if (wret
< 0 && wret
!= -ENOSPC
)
2052 if (btrfs_header_nritems(&leaf
->header
) == 0) {
2053 u64 blocknr
= bh_blocknr(leaf_buf
);
2054 clean_tree_block(trans
, root
, leaf_buf
);
2055 wait_on_buffer(leaf_buf
);
2056 wret
= del_ptr(trans
, root
, path
, 1, slot
);
2059 btrfs_block_release(root
, leaf_buf
);
2060 wret
= btrfs_free_extent(trans
, root
, blocknr
,
2065 btrfs_mark_buffer_dirty(leaf_buf
);
2066 btrfs_block_release(root
, leaf_buf
);
2069 btrfs_mark_buffer_dirty(leaf_buf
);
2076 * walk up the tree as far as required to find the next leaf.
2077 * returns 0 if it found something or 1 if there are no greater leaves.
2078 * returns < 0 on io errors.
2080 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
2085 struct buffer_head
*c
;
2086 struct btrfs_node
*c_node
;
2087 struct buffer_head
*next
= NULL
;
2089 while(level
< BTRFS_MAX_LEVEL
) {
2090 if (!path
->nodes
[level
])
2092 slot
= path
->slots
[level
] + 1;
2093 c
= path
->nodes
[level
];
2094 c_node
= btrfs_buffer_node(c
);
2095 if (slot
>= btrfs_header_nritems(&c_node
->header
)) {
2099 blocknr
= btrfs_node_blockptr(c_node
, slot
);
2101 btrfs_block_release(root
, next
);
2103 reada_for_search(root
, path
, level
, slot
);
2104 next
= read_tree_block(root
, blocknr
);
2107 path
->slots
[level
] = slot
;
2110 c
= path
->nodes
[level
];
2111 btrfs_block_release(root
, c
);
2112 path
->nodes
[level
] = next
;
2113 path
->slots
[level
] = 0;
2117 reada_for_search(root
, path
, level
, slot
);
2118 next
= read_tree_block(root
,
2119 btrfs_node_blockptr(btrfs_buffer_node(next
), 0));
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