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/sched.h>
22 #include "transaction.h"
23 #include "print-tree.h"
25 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
26 *root
, struct btrfs_path
*path
, int level
);
27 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
28 *root
, struct btrfs_key
*ins_key
,
29 struct btrfs_path
*path
, int data_size
, int extend
);
30 static int push_node_left(struct btrfs_trans_handle
*trans
,
31 struct btrfs_root
*root
, struct extent_buffer
*dst
,
32 struct extent_buffer
*src
);
33 static int balance_node_right(struct btrfs_trans_handle
*trans
,
34 struct btrfs_root
*root
,
35 struct extent_buffer
*dst_buf
,
36 struct extent_buffer
*src_buf
);
37 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
38 struct btrfs_path
*path
, int level
, int slot
);
40 inline void btrfs_init_path(struct btrfs_path
*p
)
42 memset(p
, 0, sizeof(*p
));
45 struct btrfs_path
*btrfs_alloc_path(void)
47 struct btrfs_path
*path
;
48 path
= kmem_cache_alloc(btrfs_path_cachep
, GFP_NOFS
);
50 btrfs_init_path(path
);
56 void btrfs_free_path(struct btrfs_path
*p
)
58 btrfs_release_path(NULL
, p
);
59 kmem_cache_free(btrfs_path_cachep
, p
);
62 void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
65 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
68 free_extent_buffer(p
->nodes
[i
]);
70 memset(p
, 0, sizeof(*p
));
73 int btrfs_copy_root(struct btrfs_trans_handle
*trans
,
74 struct btrfs_root
*root
,
75 struct extent_buffer
*buf
,
76 struct extent_buffer
**cow_ret
, u64 new_root_objectid
)
78 struct extent_buffer
*cow
;
82 struct btrfs_key first_key
;
83 struct btrfs_root new_root
;
85 memcpy(&new_root
, root
, sizeof(new_root
));
86 new_root
.root_key
.objectid
= new_root_objectid
;
88 WARN_ON(root
->ref_cows
&& trans
->transid
!=
89 root
->fs_info
->running_transaction
->transid
);
90 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
92 level
= btrfs_header_level(buf
);
93 nritems
= btrfs_header_nritems(buf
);
96 btrfs_item_key_to_cpu(buf
, &first_key
, 0);
98 btrfs_node_key_to_cpu(buf
, &first_key
, 0);
100 first_key
.objectid
= 0;
102 cow
= __btrfs_alloc_free_block(trans
, &new_root
, buf
->len
,
104 trans
->transid
, first_key
.objectid
,
105 level
, buf
->start
, 0);
109 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
110 btrfs_set_header_bytenr(cow
, cow
->start
);
111 btrfs_set_header_generation(cow
, trans
->transid
);
112 btrfs_set_header_owner(cow
, new_root_objectid
);
114 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
115 ret
= btrfs_inc_ref(trans
, &new_root
, buf
);
119 btrfs_mark_buffer_dirty(cow
);
124 int __btrfs_cow_block(struct btrfs_trans_handle
*trans
,
125 struct btrfs_root
*root
,
126 struct extent_buffer
*buf
,
127 struct extent_buffer
*parent
, int parent_slot
,
128 struct extent_buffer
**cow_ret
,
129 u64 search_start
, u64 empty_size
)
132 struct extent_buffer
*cow
;
135 int different_trans
= 0;
137 struct btrfs_key first_key
;
139 if (root
->ref_cows
) {
140 root_gen
= trans
->transid
;
145 WARN_ON(root
->ref_cows
&& trans
->transid
!=
146 root
->fs_info
->running_transaction
->transid
);
147 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
149 level
= btrfs_header_level(buf
);
150 nritems
= btrfs_header_nritems(buf
);
153 btrfs_item_key_to_cpu(buf
, &first_key
, 0);
155 btrfs_node_key_to_cpu(buf
, &first_key
, 0);
157 first_key
.objectid
= 0;
159 cow
= __btrfs_alloc_free_block(trans
, root
, buf
->len
,
160 root
->root_key
.objectid
,
161 root_gen
, first_key
.objectid
, level
,
162 search_start
, empty_size
);
166 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
167 btrfs_set_header_bytenr(cow
, cow
->start
);
168 btrfs_set_header_generation(cow
, trans
->transid
);
169 btrfs_set_header_owner(cow
, root
->root_key
.objectid
);
171 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
172 if (btrfs_header_generation(buf
) != trans
->transid
) {
174 ret
= btrfs_inc_ref(trans
, root
, buf
);
178 clean_tree_block(trans
, root
, buf
);
181 if (buf
== root
->node
) {
182 root_gen
= btrfs_header_generation(buf
);
184 extent_buffer_get(cow
);
185 if (buf
!= root
->commit_root
) {
186 btrfs_free_extent(trans
, root
, buf
->start
,
187 buf
->len
, root
->root_key
.objectid
,
190 free_extent_buffer(buf
);
192 root_gen
= btrfs_header_generation(parent
);
193 btrfs_set_node_blockptr(parent
, parent_slot
,
195 WARN_ON(trans
->transid
== 0);
196 btrfs_set_node_ptr_generation(parent
, parent_slot
,
198 btrfs_mark_buffer_dirty(parent
);
199 WARN_ON(btrfs_header_generation(parent
) != trans
->transid
);
200 btrfs_free_extent(trans
, root
, buf
->start
, buf
->len
,
201 btrfs_header_owner(parent
), root_gen
,
204 free_extent_buffer(buf
);
205 btrfs_mark_buffer_dirty(cow
);
210 int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
211 struct btrfs_root
*root
, struct extent_buffer
*buf
,
212 struct extent_buffer
*parent
, int parent_slot
,
213 struct extent_buffer
**cow_ret
)
217 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
218 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
219 root
->fs_info
->running_transaction
->transid
);
222 if (trans
->transid
!= root
->fs_info
->generation
) {
223 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
224 root
->fs_info
->generation
);
227 if (btrfs_header_generation(buf
) == trans
->transid
) {
232 search_start
= buf
->start
& ~((u64
)BTRFS_BLOCK_GROUP_SIZE
- 1);
233 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
234 parent_slot
, cow_ret
, search_start
, 0);
238 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
240 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
242 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
248 * compare two keys in a memcmp fashion
250 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
254 btrfs_disk_key_to_cpu(&k1
, disk
);
256 if (k1
.objectid
> k2
->objectid
)
258 if (k1
.objectid
< k2
->objectid
)
260 if (k1
.type
> k2
->type
)
262 if (k1
.type
< k2
->type
)
264 if (k1
.offset
> k2
->offset
)
266 if (k1
.offset
< k2
->offset
)
272 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
273 struct btrfs_root
*root
, struct extent_buffer
*parent
,
274 int start_slot
, int cache_only
, u64
*last_ret
,
275 struct btrfs_key
*progress
)
277 struct extent_buffer
*cur
;
278 struct extent_buffer
*tmp
;
280 u64 search_start
= *last_ret
;
290 int progress_passed
= 0;
291 struct btrfs_disk_key disk_key
;
293 parent_level
= btrfs_header_level(parent
);
294 if (cache_only
&& parent_level
!= 1)
297 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
298 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
299 root
->fs_info
->running_transaction
->transid
);
302 if (trans
->transid
!= root
->fs_info
->generation
) {
303 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
304 root
->fs_info
->generation
);
308 parent_nritems
= btrfs_header_nritems(parent
);
309 blocksize
= btrfs_level_size(root
, parent_level
- 1);
310 end_slot
= parent_nritems
;
312 if (parent_nritems
== 1)
315 for (i
= start_slot
; i
< end_slot
; i
++) {
318 if (!parent
->map_token
) {
319 map_extent_buffer(parent
,
320 btrfs_node_key_ptr_offset(i
),
321 sizeof(struct btrfs_key_ptr
),
322 &parent
->map_token
, &parent
->kaddr
,
323 &parent
->map_start
, &parent
->map_len
,
326 btrfs_node_key(parent
, &disk_key
, i
);
327 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
331 blocknr
= btrfs_node_blockptr(parent
, i
);
333 last_block
= blocknr
;
336 other
= btrfs_node_blockptr(parent
, i
- 1);
337 close
= close_blocks(blocknr
, other
, blocksize
);
339 if (close
&& i
< end_slot
- 2) {
340 other
= btrfs_node_blockptr(parent
, i
+ 1);
341 close
= close_blocks(blocknr
, other
, blocksize
);
344 last_block
= blocknr
;
347 if (parent
->map_token
) {
348 unmap_extent_buffer(parent
, parent
->map_token
,
350 parent
->map_token
= NULL
;
353 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
355 uptodate
= btrfs_buffer_uptodate(cur
);
358 if (!cur
|| !uptodate
) {
360 free_extent_buffer(cur
);
364 cur
= read_tree_block(root
, blocknr
,
366 } else if (!uptodate
) {
367 btrfs_read_buffer(cur
);
370 if (search_start
== 0)
371 search_start
= last_block
;
373 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
376 (end_slot
- i
) * blocksize
));
378 free_extent_buffer(cur
);
381 search_start
= tmp
->start
;
382 last_block
= tmp
->start
;
383 *last_ret
= search_start
;
384 if (parent_level
== 1)
385 btrfs_clear_buffer_defrag(tmp
);
386 free_extent_buffer(tmp
);
388 if (parent
->map_token
) {
389 unmap_extent_buffer(parent
, parent
->map_token
,
391 parent
->map_token
= NULL
;
397 * The leaf data grows from end-to-front in the node.
398 * this returns the address of the start of the last item,
399 * which is the stop of the leaf data stack
401 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
402 struct extent_buffer
*leaf
)
404 u32 nr
= btrfs_header_nritems(leaf
);
406 return BTRFS_LEAF_DATA_SIZE(root
);
407 return btrfs_item_offset_nr(leaf
, nr
- 1);
410 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
413 struct extent_buffer
*parent
= NULL
;
414 struct extent_buffer
*node
= path
->nodes
[level
];
415 struct btrfs_disk_key parent_key
;
416 struct btrfs_disk_key node_key
;
419 struct btrfs_key cpukey
;
420 u32 nritems
= btrfs_header_nritems(node
);
422 if (path
->nodes
[level
+ 1])
423 parent
= path
->nodes
[level
+ 1];
425 slot
= path
->slots
[level
];
426 BUG_ON(nritems
== 0);
428 parent_slot
= path
->slots
[level
+ 1];
429 btrfs_node_key(parent
, &parent_key
, parent_slot
);
430 btrfs_node_key(node
, &node_key
, 0);
431 BUG_ON(memcmp(&parent_key
, &node_key
,
432 sizeof(struct btrfs_disk_key
)));
433 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
434 btrfs_header_bytenr(node
));
436 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
438 btrfs_node_key_to_cpu(node
, &cpukey
, slot
- 1);
439 btrfs_node_key(node
, &node_key
, slot
);
440 BUG_ON(comp_keys(&node_key
, &cpukey
) <= 0);
442 if (slot
< nritems
- 1) {
443 btrfs_node_key_to_cpu(node
, &cpukey
, slot
+ 1);
444 btrfs_node_key(node
, &node_key
, slot
);
445 BUG_ON(comp_keys(&node_key
, &cpukey
) >= 0);
450 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
453 struct extent_buffer
*leaf
= path
->nodes
[level
];
454 struct extent_buffer
*parent
= NULL
;
456 struct btrfs_key cpukey
;
457 struct btrfs_disk_key parent_key
;
458 struct btrfs_disk_key leaf_key
;
459 int slot
= path
->slots
[0];
461 u32 nritems
= btrfs_header_nritems(leaf
);
463 if (path
->nodes
[level
+ 1])
464 parent
= path
->nodes
[level
+ 1];
470 parent_slot
= path
->slots
[level
+ 1];
471 btrfs_node_key(parent
, &parent_key
, parent_slot
);
472 btrfs_item_key(leaf
, &leaf_key
, 0);
474 BUG_ON(memcmp(&parent_key
, &leaf_key
,
475 sizeof(struct btrfs_disk_key
)));
476 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
477 btrfs_header_bytenr(leaf
));
480 for (i
= 0; nritems
> 1 && i
< nritems
- 2; i
++) {
481 btrfs_item_key_to_cpu(leaf
, &cpukey
, i
+ 1);
482 btrfs_item_key(leaf
, &leaf_key
, i
);
483 if (comp_keys(&leaf_key
, &cpukey
) >= 0) {
484 btrfs_print_leaf(root
, leaf
);
485 printk("slot %d offset bad key\n", i
);
488 if (btrfs_item_offset_nr(leaf
, i
) !=
489 btrfs_item_end_nr(leaf
, i
+ 1)) {
490 btrfs_print_leaf(root
, leaf
);
491 printk("slot %d offset bad\n", i
);
495 if (btrfs_item_offset_nr(leaf
, i
) +
496 btrfs_item_size_nr(leaf
, i
) !=
497 BTRFS_LEAF_DATA_SIZE(root
)) {
498 btrfs_print_leaf(root
, leaf
);
499 printk("slot %d first offset bad\n", i
);
505 if (btrfs_item_size_nr(leaf
, nritems
- 1) > 4096) {
506 btrfs_print_leaf(root
, leaf
);
507 printk("slot %d bad size \n", nritems
- 1);
512 if (slot
!= 0 && slot
< nritems
- 1) {
513 btrfs_item_key(leaf
, &leaf_key
, slot
);
514 btrfs_item_key_to_cpu(leaf
, &cpukey
, slot
- 1);
515 if (comp_keys(&leaf_key
, &cpukey
) <= 0) {
516 btrfs_print_leaf(root
, leaf
);
517 printk("slot %d offset bad key\n", slot
);
520 if (btrfs_item_offset_nr(leaf
, slot
- 1) !=
521 btrfs_item_end_nr(leaf
, slot
)) {
522 btrfs_print_leaf(root
, leaf
);
523 printk("slot %d offset bad\n", slot
);
527 if (slot
< nritems
- 1) {
528 btrfs_item_key(leaf
, &leaf_key
, slot
);
529 btrfs_item_key_to_cpu(leaf
, &cpukey
, slot
+ 1);
530 BUG_ON(comp_keys(&leaf_key
, &cpukey
) >= 0);
531 if (btrfs_item_offset_nr(leaf
, slot
) !=
532 btrfs_item_end_nr(leaf
, slot
+ 1)) {
533 btrfs_print_leaf(root
, leaf
);
534 printk("slot %d offset bad\n", slot
);
538 BUG_ON(btrfs_item_offset_nr(leaf
, 0) +
539 btrfs_item_size_nr(leaf
, 0) != BTRFS_LEAF_DATA_SIZE(root
));
543 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
548 struct extent_buffer
*buf
= path
->nodes
[level
];
550 if (memcmp_extent_buffer(buf
, root
->fs_info
->fsid
,
551 (unsigned long)btrfs_header_fsid(buf
),
553 printk("warning bad block %Lu\n", buf
->start
);
558 return check_leaf(root
, path
, level
);
559 return check_node(root
, path
, level
);
563 * search for key in the extent_buffer. The items start at offset p,
564 * and they are item_size apart. There are 'max' items in p.
566 * the slot in the array is returned via slot, and it points to
567 * the place where you would insert key if it is not found in
570 * slot may point to max if the key is bigger than all of the keys
572 static int generic_bin_search(struct extent_buffer
*eb
, unsigned long p
,
573 int item_size
, struct btrfs_key
*key
,
580 struct btrfs_disk_key
*tmp
= NULL
;
581 struct btrfs_disk_key unaligned
;
582 unsigned long offset
;
583 char *map_token
= NULL
;
585 unsigned long map_start
= 0;
586 unsigned long map_len
= 0;
590 mid
= (low
+ high
) / 2;
591 offset
= p
+ mid
* item_size
;
593 if (!map_token
|| offset
< map_start
||
594 (offset
+ sizeof(struct btrfs_disk_key
)) >
595 map_start
+ map_len
) {
597 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
600 err
= map_extent_buffer(eb
, offset
,
601 sizeof(struct btrfs_disk_key
),
603 &map_start
, &map_len
, KM_USER0
);
606 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
609 read_extent_buffer(eb
, &unaligned
,
610 offset
, sizeof(unaligned
));
615 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
618 ret
= comp_keys(tmp
, key
);
627 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
633 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
638 * simple bin_search frontend that does the right thing for
641 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
642 int level
, int *slot
)
645 return generic_bin_search(eb
,
646 offsetof(struct btrfs_leaf
, items
),
647 sizeof(struct btrfs_item
),
648 key
, btrfs_header_nritems(eb
),
651 return generic_bin_search(eb
,
652 offsetof(struct btrfs_node
, ptrs
),
653 sizeof(struct btrfs_key_ptr
),
654 key
, btrfs_header_nritems(eb
),
660 static struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
661 struct extent_buffer
*parent
, int slot
)
665 if (slot
>= btrfs_header_nritems(parent
))
667 return read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
668 btrfs_level_size(root
, btrfs_header_level(parent
) - 1));
671 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
672 *root
, struct btrfs_path
*path
, int level
)
674 struct extent_buffer
*right
= NULL
;
675 struct extent_buffer
*mid
;
676 struct extent_buffer
*left
= NULL
;
677 struct extent_buffer
*parent
= NULL
;
681 int orig_slot
= path
->slots
[level
];
682 int err_on_enospc
= 0;
688 mid
= path
->nodes
[level
];
689 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
691 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
693 if (level
< BTRFS_MAX_LEVEL
- 1)
694 parent
= path
->nodes
[level
+ 1];
695 pslot
= path
->slots
[level
+ 1];
698 * deal with the case where there is only one pointer in the root
699 * by promoting the node below to a root
702 struct extent_buffer
*child
;
704 if (btrfs_header_nritems(mid
) != 1)
707 /* promote the child to a root */
708 child
= read_node_slot(root
, mid
, 0);
711 path
->nodes
[level
] = NULL
;
712 clean_tree_block(trans
, root
, mid
);
713 wait_on_tree_block_writeback(root
, mid
);
714 /* once for the path */
715 free_extent_buffer(mid
);
716 ret
= btrfs_free_extent(trans
, root
, mid
->start
, mid
->len
,
717 root
->root_key
.objectid
,
718 btrfs_header_generation(mid
), 0, 0, 1);
719 /* once for the root ptr */
720 free_extent_buffer(mid
);
723 if (btrfs_header_nritems(mid
) >
724 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
727 if (btrfs_header_nritems(mid
) < 2)
730 left
= read_node_slot(root
, parent
, pslot
- 1);
732 wret
= btrfs_cow_block(trans
, root
, left
,
733 parent
, pslot
- 1, &left
);
739 right
= read_node_slot(root
, parent
, pslot
+ 1);
741 wret
= btrfs_cow_block(trans
, root
, right
,
742 parent
, pslot
+ 1, &right
);
749 /* first, try to make some room in the middle buffer */
751 orig_slot
+= btrfs_header_nritems(left
);
752 wret
= push_node_left(trans
, root
, left
, mid
);
755 if (btrfs_header_nritems(mid
) < 2)
760 * then try to empty the right most buffer into the middle
763 wret
= push_node_left(trans
, root
, mid
, right
);
764 if (wret
< 0 && wret
!= -ENOSPC
)
766 if (btrfs_header_nritems(right
) == 0) {
767 u64 bytenr
= right
->start
;
768 u64 generation
= btrfs_header_generation(parent
);
769 u32 blocksize
= right
->len
;
771 clean_tree_block(trans
, root
, right
);
772 wait_on_tree_block_writeback(root
, right
);
773 free_extent_buffer(right
);
775 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
779 wret
= btrfs_free_extent(trans
, root
, bytenr
,
781 btrfs_header_owner(parent
),
782 generation
, 0, 0, 1);
786 struct btrfs_disk_key right_key
;
787 btrfs_node_key(right
, &right_key
, 0);
788 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
789 btrfs_mark_buffer_dirty(parent
);
792 if (btrfs_header_nritems(mid
) == 1) {
794 * we're not allowed to leave a node with one item in the
795 * tree during a delete. A deletion from lower in the tree
796 * could try to delete the only pointer in this node.
797 * So, pull some keys from the left.
798 * There has to be a left pointer at this point because
799 * otherwise we would have pulled some pointers from the
803 wret
= balance_node_right(trans
, root
, mid
, left
);
810 if (btrfs_header_nritems(mid
) == 0) {
811 /* we've managed to empty the middle node, drop it */
812 u64 root_gen
= btrfs_header_generation(parent
);
813 u64 bytenr
= mid
->start
;
814 u32 blocksize
= mid
->len
;
815 clean_tree_block(trans
, root
, mid
);
816 wait_on_tree_block_writeback(root
, mid
);
817 free_extent_buffer(mid
);
819 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
822 wret
= btrfs_free_extent(trans
, root
, bytenr
, blocksize
,
823 btrfs_header_owner(parent
),
828 /* update the parent key to reflect our changes */
829 struct btrfs_disk_key mid_key
;
830 btrfs_node_key(mid
, &mid_key
, 0);
831 btrfs_set_node_key(parent
, &mid_key
, pslot
);
832 btrfs_mark_buffer_dirty(parent
);
835 /* update the path */
837 if (btrfs_header_nritems(left
) > orig_slot
) {
838 extent_buffer_get(left
);
839 path
->nodes
[level
] = left
;
840 path
->slots
[level
+ 1] -= 1;
841 path
->slots
[level
] = orig_slot
;
843 free_extent_buffer(mid
);
845 orig_slot
-= btrfs_header_nritems(left
);
846 path
->slots
[level
] = orig_slot
;
849 /* double check we haven't messed things up */
850 check_block(root
, path
, level
);
852 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
856 free_extent_buffer(right
);
858 free_extent_buffer(left
);
862 /* returns zero if the push worked, non-zero otherwise */
863 static int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
864 struct btrfs_root
*root
,
865 struct btrfs_path
*path
, int level
)
867 struct extent_buffer
*right
= NULL
;
868 struct extent_buffer
*mid
;
869 struct extent_buffer
*left
= NULL
;
870 struct extent_buffer
*parent
= NULL
;
874 int orig_slot
= path
->slots
[level
];
880 mid
= path
->nodes
[level
];
881 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
882 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
884 if (level
< BTRFS_MAX_LEVEL
- 1)
885 parent
= path
->nodes
[level
+ 1];
886 pslot
= path
->slots
[level
+ 1];
891 left
= read_node_slot(root
, parent
, pslot
- 1);
893 /* first, try to make some room in the middle buffer */
896 left_nr
= btrfs_header_nritems(left
);
897 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
900 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
905 wret
= push_node_left(trans
, root
,
912 struct btrfs_disk_key disk_key
;
913 orig_slot
+= left_nr
;
914 btrfs_node_key(mid
, &disk_key
, 0);
915 btrfs_set_node_key(parent
, &disk_key
, pslot
);
916 btrfs_mark_buffer_dirty(parent
);
917 if (btrfs_header_nritems(left
) > orig_slot
) {
918 path
->nodes
[level
] = left
;
919 path
->slots
[level
+ 1] -= 1;
920 path
->slots
[level
] = orig_slot
;
921 free_extent_buffer(mid
);
924 btrfs_header_nritems(left
);
925 path
->slots
[level
] = orig_slot
;
926 free_extent_buffer(left
);
930 free_extent_buffer(left
);
932 right
= read_node_slot(root
, parent
, pslot
+ 1);
935 * then try to empty the right most buffer into the middle
939 right_nr
= btrfs_header_nritems(right
);
940 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
943 ret
= btrfs_cow_block(trans
, root
, right
,
949 wret
= balance_node_right(trans
, root
,
956 struct btrfs_disk_key disk_key
;
958 btrfs_node_key(right
, &disk_key
, 0);
959 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
960 btrfs_mark_buffer_dirty(parent
);
962 if (btrfs_header_nritems(mid
) <= orig_slot
) {
963 path
->nodes
[level
] = right
;
964 path
->slots
[level
+ 1] += 1;
965 path
->slots
[level
] = orig_slot
-
966 btrfs_header_nritems(mid
);
967 free_extent_buffer(mid
);
969 free_extent_buffer(right
);
973 free_extent_buffer(right
);
979 * readahead one full node of leaves
981 static void reada_for_search(struct btrfs_root
*root
, struct btrfs_path
*path
,
984 struct extent_buffer
*node
;
990 int direction
= path
->reada
;
991 struct extent_buffer
*eb
;
999 if (!path
->nodes
[level
])
1002 node
= path
->nodes
[level
];
1003 search
= btrfs_node_blockptr(node
, slot
);
1004 blocksize
= btrfs_level_size(root
, level
- 1);
1005 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
1007 free_extent_buffer(eb
);
1011 highest_read
= search
;
1012 lowest_read
= search
;
1014 nritems
= btrfs_header_nritems(node
);
1017 if (direction
< 0) {
1021 } else if (direction
> 0) {
1026 search
= btrfs_node_blockptr(node
, nr
);
1027 if ((search
>= lowest_read
&& search
<= highest_read
) ||
1028 (search
< lowest_read
&& lowest_read
- search
<= 32768) ||
1029 (search
> highest_read
&& search
- highest_read
<= 32768)) {
1030 readahead_tree_block(root
, search
, blocksize
);
1034 if (path
->reada
< 2 && (nread
> (256 * 1024) || nscan
> 32))
1036 if(nread
> (1024 * 1024) || nscan
> 128)
1039 if (search
< lowest_read
)
1040 lowest_read
= search
;
1041 if (search
> highest_read
)
1042 highest_read
= search
;
1046 * look for key in the tree. path is filled in with nodes along the way
1047 * if key is found, we return zero and you can find the item in the leaf
1048 * level of the path (level 0)
1050 * If the key isn't found, the path points to the slot where it should
1051 * be inserted, and 1 is returned. If there are other errors during the
1052 * search a negative error number is returned.
1054 * if ins_len > 0, nodes and leaves will be split as we walk down the
1055 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1058 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
1059 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
1062 struct extent_buffer
*b
;
1068 int should_reada
= p
->reada
;
1069 u8 lowest_level
= 0;
1071 lowest_level
= p
->lowest_level
;
1072 WARN_ON(lowest_level
&& ins_len
);
1073 WARN_ON(p
->nodes
[0] != NULL
);
1074 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
1077 extent_buffer_get(b
);
1079 level
= btrfs_header_level(b
);
1082 wret
= btrfs_cow_block(trans
, root
, b
,
1083 p
->nodes
[level
+ 1],
1084 p
->slots
[level
+ 1],
1087 free_extent_buffer(b
);
1091 BUG_ON(!cow
&& ins_len
);
1092 if (level
!= btrfs_header_level(b
))
1094 level
= btrfs_header_level(b
);
1095 p
->nodes
[level
] = b
;
1096 ret
= check_block(root
, p
, level
);
1099 ret
= bin_search(b
, key
, level
, &slot
);
1101 if (ret
&& slot
> 0)
1103 p
->slots
[level
] = slot
;
1104 if (ins_len
> 0 && btrfs_header_nritems(b
) >=
1105 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1106 int sret
= split_node(trans
, root
, p
, level
);
1110 b
= p
->nodes
[level
];
1111 slot
= p
->slots
[level
];
1112 } else if (ins_len
< 0) {
1113 int sret
= balance_level(trans
, root
, p
,
1117 b
= p
->nodes
[level
];
1119 btrfs_release_path(NULL
, p
);
1122 slot
= p
->slots
[level
];
1123 BUG_ON(btrfs_header_nritems(b
) == 1);
1125 /* this is only true while dropping a snapshot */
1126 if (level
== lowest_level
)
1128 bytenr
= btrfs_node_blockptr(b
, slot
);
1129 ptr_gen
= btrfs_node_ptr_generation(b
, slot
);
1131 reada_for_search(root
, p
, level
, slot
);
1132 b
= read_tree_block(root
, bytenr
,
1133 btrfs_level_size(root
, level
- 1));
1134 if (ptr_gen
!= btrfs_header_generation(b
)) {
1135 printk("block %llu bad gen wanted %llu "
1137 (unsigned long long)b
->start
,
1138 (unsigned long long)ptr_gen
,
1139 (unsigned long long)btrfs_header_generation(b
));
1142 p
->slots
[level
] = slot
;
1143 if (ins_len
> 0 && btrfs_leaf_free_space(root
, b
) <
1144 sizeof(struct btrfs_item
) + ins_len
) {
1145 int sret
= split_leaf(trans
, root
, key
,
1146 p
, ins_len
, ret
== 0);
1158 * adjust the pointers going up the tree, starting at level
1159 * making sure the right key of each node is points to 'key'.
1160 * This is used after shifting pointers to the left, so it stops
1161 * fixing up pointers when a given leaf/node is not in slot 0 of the
1164 * If this fails to write a tree block, it returns -1, but continues
1165 * fixing up the blocks in ram so the tree is consistent.
1167 static int fixup_low_keys(struct btrfs_trans_handle
*trans
,
1168 struct btrfs_root
*root
, struct btrfs_path
*path
,
1169 struct btrfs_disk_key
*key
, int level
)
1173 struct extent_buffer
*t
;
1175 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1176 int tslot
= path
->slots
[i
];
1177 if (!path
->nodes
[i
])
1180 btrfs_set_node_key(t
, key
, tslot
);
1181 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
1189 * try to push data from one node into the next node left in the
1192 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1193 * error, and > 0 if there was no room in the left hand block.
1195 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1196 *root
, struct extent_buffer
*dst
,
1197 struct extent_buffer
*src
)
1204 src_nritems
= btrfs_header_nritems(src
);
1205 dst_nritems
= btrfs_header_nritems(dst
);
1206 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1207 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1208 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1210 if (push_items
<= 0) {
1214 if (src_nritems
< push_items
)
1215 push_items
= src_nritems
;
1217 copy_extent_buffer(dst
, src
,
1218 btrfs_node_key_ptr_offset(dst_nritems
),
1219 btrfs_node_key_ptr_offset(0),
1220 push_items
* sizeof(struct btrfs_key_ptr
));
1222 if (push_items
< src_nritems
) {
1223 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
1224 btrfs_node_key_ptr_offset(push_items
),
1225 (src_nritems
- push_items
) *
1226 sizeof(struct btrfs_key_ptr
));
1228 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1229 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1230 btrfs_mark_buffer_dirty(src
);
1231 btrfs_mark_buffer_dirty(dst
);
1236 * try to push data from one node into the next node right in the
1239 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1240 * error, and > 0 if there was no room in the right hand block.
1242 * this will only push up to 1/2 the contents of the left node over
1244 static int balance_node_right(struct btrfs_trans_handle
*trans
,
1245 struct btrfs_root
*root
,
1246 struct extent_buffer
*dst
,
1247 struct extent_buffer
*src
)
1255 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1256 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1258 src_nritems
= btrfs_header_nritems(src
);
1259 dst_nritems
= btrfs_header_nritems(dst
);
1260 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1261 if (push_items
<= 0)
1264 max_push
= src_nritems
/ 2 + 1;
1265 /* don't try to empty the node */
1266 if (max_push
>= src_nritems
)
1269 if (max_push
< push_items
)
1270 push_items
= max_push
;
1272 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
1273 btrfs_node_key_ptr_offset(0),
1275 sizeof(struct btrfs_key_ptr
));
1277 copy_extent_buffer(dst
, src
,
1278 btrfs_node_key_ptr_offset(0),
1279 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
1280 push_items
* sizeof(struct btrfs_key_ptr
));
1282 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1283 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1285 btrfs_mark_buffer_dirty(src
);
1286 btrfs_mark_buffer_dirty(dst
);
1291 * helper function to insert a new root level in the tree.
1292 * A new node is allocated, and a single item is inserted to
1293 * point to the existing root
1295 * returns zero on success or < 0 on failure.
1297 static int insert_new_root(struct btrfs_trans_handle
*trans
,
1298 struct btrfs_root
*root
,
1299 struct btrfs_path
*path
, int level
)
1303 struct extent_buffer
*lower
;
1304 struct extent_buffer
*c
;
1305 struct btrfs_disk_key lower_key
;
1307 BUG_ON(path
->nodes
[level
]);
1308 BUG_ON(path
->nodes
[level
-1] != root
->node
);
1311 root_gen
= trans
->transid
;
1315 lower
= path
->nodes
[level
-1];
1317 btrfs_item_key(lower
, &lower_key
, 0);
1319 btrfs_node_key(lower
, &lower_key
, 0);
1321 c
= __btrfs_alloc_free_block(trans
, root
, root
->nodesize
,
1322 root
->root_key
.objectid
,
1323 root_gen
, lower_key
.objectid
, level
,
1324 root
->node
->start
, 0);
1327 memset_extent_buffer(c
, 0, 0, root
->nodesize
);
1328 btrfs_set_header_nritems(c
, 1);
1329 btrfs_set_header_level(c
, level
);
1330 btrfs_set_header_bytenr(c
, c
->start
);
1331 btrfs_set_header_generation(c
, trans
->transid
);
1332 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
1334 write_extent_buffer(c
, root
->fs_info
->fsid
,
1335 (unsigned long)btrfs_header_fsid(c
),
1337 btrfs_set_node_key(c
, &lower_key
, 0);
1338 btrfs_set_node_blockptr(c
, 0, lower
->start
);
1339 lower_gen
= btrfs_header_generation(lower
);
1340 WARN_ON(lower_gen
== 0);
1342 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
1344 btrfs_mark_buffer_dirty(c
);
1346 /* the super has an extra ref to root->node */
1347 free_extent_buffer(root
->node
);
1349 extent_buffer_get(c
);
1350 path
->nodes
[level
] = c
;
1351 path
->slots
[level
] = 0;
1353 if (root
->ref_cows
&& lower_gen
!= trans
->transid
) {
1354 struct btrfs_path
*back_path
= btrfs_alloc_path();
1356 ret
= btrfs_insert_extent_backref(trans
,
1357 root
->fs_info
->extent_root
,
1359 root
->root_key
.objectid
,
1360 trans
->transid
, 0, 0);
1362 btrfs_free_path(back_path
);
1368 * worker function to insert a single pointer in a node.
1369 * the node should have enough room for the pointer already
1371 * slot and level indicate where you want the key to go, and
1372 * blocknr is the block the key points to.
1374 * returns zero on success and < 0 on any error
1376 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
1377 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
1378 *key
, u64 bytenr
, int slot
, int level
)
1380 struct extent_buffer
*lower
;
1383 BUG_ON(!path
->nodes
[level
]);
1384 lower
= path
->nodes
[level
];
1385 nritems
= btrfs_header_nritems(lower
);
1388 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
1390 if (slot
!= nritems
) {
1391 memmove_extent_buffer(lower
,
1392 btrfs_node_key_ptr_offset(slot
+ 1),
1393 btrfs_node_key_ptr_offset(slot
),
1394 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
1396 btrfs_set_node_key(lower
, key
, slot
);
1397 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
1398 WARN_ON(trans
->transid
== 0);
1399 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
1400 btrfs_set_header_nritems(lower
, nritems
+ 1);
1401 btrfs_mark_buffer_dirty(lower
);
1406 * split the node at the specified level in path in two.
1407 * The path is corrected to point to the appropriate node after the split
1409 * Before splitting this tries to make some room in the node by pushing
1410 * left and right, if either one works, it returns right away.
1412 * returns 0 on success and < 0 on failure
1414 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
1415 *root
, struct btrfs_path
*path
, int level
)
1418 struct extent_buffer
*c
;
1419 struct extent_buffer
*split
;
1420 struct btrfs_disk_key disk_key
;
1426 c
= path
->nodes
[level
];
1427 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
1428 if (c
== root
->node
) {
1429 /* trying to split the root, lets make a new one */
1430 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
1434 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
1435 c
= path
->nodes
[level
];
1436 if (!ret
&& btrfs_header_nritems(c
) <
1437 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1)
1443 c_nritems
= btrfs_header_nritems(c
);
1445 root_gen
= trans
->transid
;
1449 btrfs_node_key(c
, &disk_key
, 0);
1450 split
= __btrfs_alloc_free_block(trans
, root
, root
->nodesize
,
1451 root
->root_key
.objectid
,
1453 btrfs_disk_key_objectid(&disk_key
),
1454 level
, c
->start
, 0);
1456 return PTR_ERR(split
);
1458 btrfs_set_header_flags(split
, btrfs_header_flags(c
));
1459 btrfs_set_header_level(split
, btrfs_header_level(c
));
1460 btrfs_set_header_bytenr(split
, split
->start
);
1461 btrfs_set_header_generation(split
, trans
->transid
);
1462 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
1463 write_extent_buffer(split
, root
->fs_info
->fsid
,
1464 (unsigned long)btrfs_header_fsid(split
),
1467 mid
= (c_nritems
+ 1) / 2;
1469 copy_extent_buffer(split
, c
,
1470 btrfs_node_key_ptr_offset(0),
1471 btrfs_node_key_ptr_offset(mid
),
1472 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
1473 btrfs_set_header_nritems(split
, c_nritems
- mid
);
1474 btrfs_set_header_nritems(c
, mid
);
1477 btrfs_mark_buffer_dirty(c
);
1478 btrfs_mark_buffer_dirty(split
);
1480 btrfs_node_key(split
, &disk_key
, 0);
1481 wret
= insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
1482 path
->slots
[level
+ 1] + 1,
1487 if (path
->slots
[level
] >= mid
) {
1488 path
->slots
[level
] -= mid
;
1489 free_extent_buffer(c
);
1490 path
->nodes
[level
] = split
;
1491 path
->slots
[level
+ 1] += 1;
1493 free_extent_buffer(split
);
1499 * how many bytes are required to store the items in a leaf. start
1500 * and nr indicate which items in the leaf to check. This totals up the
1501 * space used both by the item structs and the item data
1503 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
1506 int nritems
= btrfs_header_nritems(l
);
1507 int end
= min(nritems
, start
+ nr
) - 1;
1511 data_len
= btrfs_item_end_nr(l
, start
);
1512 data_len
= data_len
- btrfs_item_offset_nr(l
, end
);
1513 data_len
+= sizeof(struct btrfs_item
) * nr
;
1514 WARN_ON(data_len
< 0);
1519 * The space between the end of the leaf items and
1520 * the start of the leaf data. IOW, how much room
1521 * the leaf has left for both items and data
1523 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct extent_buffer
*leaf
)
1525 int nritems
= btrfs_header_nritems(leaf
);
1527 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
1529 printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n",
1530 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
1531 leaf_space_used(leaf
, 0, nritems
), nritems
);
1537 * push some data in the path leaf to the right, trying to free up at
1538 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1540 * returns 1 if the push failed because the other node didn't have enough
1541 * room, 0 if everything worked out and < 0 if there were major errors.
1543 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
1544 *root
, struct btrfs_path
*path
, int data_size
,
1547 struct extent_buffer
*left
= path
->nodes
[0];
1548 struct extent_buffer
*right
;
1549 struct extent_buffer
*upper
;
1550 struct btrfs_disk_key disk_key
;
1556 struct btrfs_item
*item
;
1564 slot
= path
->slots
[1];
1565 if (!path
->nodes
[1]) {
1568 upper
= path
->nodes
[1];
1569 if (slot
>= btrfs_header_nritems(upper
) - 1)
1572 right
= read_tree_block(root
, btrfs_node_blockptr(upper
, slot
+ 1),
1574 free_space
= btrfs_leaf_free_space(root
, right
);
1575 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1576 free_extent_buffer(right
);
1580 /* cow and double check */
1581 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
1584 free_extent_buffer(right
);
1587 free_space
= btrfs_leaf_free_space(root
, right
);
1588 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1589 free_extent_buffer(right
);
1593 left_nritems
= btrfs_header_nritems(left
);
1594 if (left_nritems
== 0) {
1595 free_extent_buffer(right
);
1604 i
= left_nritems
- 1;
1606 item
= btrfs_item_nr(left
, i
);
1608 if (path
->slots
[0] == i
)
1609 push_space
+= data_size
+ sizeof(*item
);
1611 if (!left
->map_token
) {
1612 map_extent_buffer(left
, (unsigned long)item
,
1613 sizeof(struct btrfs_item
),
1614 &left
->map_token
, &left
->kaddr
,
1615 &left
->map_start
, &left
->map_len
,
1619 this_item_size
= btrfs_item_size(left
, item
);
1620 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
1623 push_space
+= this_item_size
+ sizeof(*item
);
1628 if (left
->map_token
) {
1629 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
1630 left
->map_token
= NULL
;
1633 if (push_items
== 0) {
1634 free_extent_buffer(right
);
1638 if (!empty
&& push_items
== left_nritems
)
1641 /* push left to right */
1642 right_nritems
= btrfs_header_nritems(right
);
1644 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
1645 push_space
-= leaf_data_end(root
, left
);
1647 /* make room in the right data area */
1648 data_end
= leaf_data_end(root
, right
);
1649 memmove_extent_buffer(right
,
1650 btrfs_leaf_data(right
) + data_end
- push_space
,
1651 btrfs_leaf_data(right
) + data_end
,
1652 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
1654 /* copy from the left data area */
1655 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
1656 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1657 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1660 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
1661 btrfs_item_nr_offset(0),
1662 right_nritems
* sizeof(struct btrfs_item
));
1664 /* copy the items from left to right */
1665 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
1666 btrfs_item_nr_offset(left_nritems
- push_items
),
1667 push_items
* sizeof(struct btrfs_item
));
1669 /* update the item pointers */
1670 right_nritems
+= push_items
;
1671 btrfs_set_header_nritems(right
, right_nritems
);
1672 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1673 for (i
= 0; i
< right_nritems
; i
++) {
1674 item
= btrfs_item_nr(right
, i
);
1675 if (!right
->map_token
) {
1676 map_extent_buffer(right
, (unsigned long)item
,
1677 sizeof(struct btrfs_item
),
1678 &right
->map_token
, &right
->kaddr
,
1679 &right
->map_start
, &right
->map_len
,
1682 push_space
-= btrfs_item_size(right
, item
);
1683 btrfs_set_item_offset(right
, item
, push_space
);
1686 if (right
->map_token
) {
1687 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
1688 right
->map_token
= NULL
;
1690 left_nritems
-= push_items
;
1691 btrfs_set_header_nritems(left
, left_nritems
);
1694 btrfs_mark_buffer_dirty(left
);
1695 btrfs_mark_buffer_dirty(right
);
1697 btrfs_item_key(right
, &disk_key
, 0);
1698 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
1699 btrfs_mark_buffer_dirty(upper
);
1701 /* then fixup the leaf pointer in the path */
1702 if (path
->slots
[0] >= left_nritems
) {
1703 path
->slots
[0] -= left_nritems
;
1704 free_extent_buffer(path
->nodes
[0]);
1705 path
->nodes
[0] = right
;
1706 path
->slots
[1] += 1;
1708 free_extent_buffer(right
);
1713 * push some data in the path leaf to the left, trying to free up at
1714 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1716 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1717 *root
, struct btrfs_path
*path
, int data_size
,
1720 struct btrfs_disk_key disk_key
;
1721 struct extent_buffer
*right
= path
->nodes
[0];
1722 struct extent_buffer
*left
;
1728 struct btrfs_item
*item
;
1729 u32 old_left_nritems
;
1735 u32 old_left_item_size
;
1737 slot
= path
->slots
[1];
1740 if (!path
->nodes
[1])
1743 right_nritems
= btrfs_header_nritems(right
);
1744 if (right_nritems
== 0) {
1748 left
= read_tree_block(root
, btrfs_node_blockptr(path
->nodes
[1],
1749 slot
- 1), root
->leafsize
);
1750 free_space
= btrfs_leaf_free_space(root
, left
);
1751 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1752 free_extent_buffer(left
);
1756 /* cow and double check */
1757 ret
= btrfs_cow_block(trans
, root
, left
,
1758 path
->nodes
[1], slot
- 1, &left
);
1760 /* we hit -ENOSPC, but it isn't fatal here */
1761 free_extent_buffer(left
);
1765 free_space
= btrfs_leaf_free_space(root
, left
);
1766 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1767 free_extent_buffer(left
);
1774 nr
= right_nritems
- 1;
1776 for (i
= 0; i
< nr
; i
++) {
1777 item
= btrfs_item_nr(right
, i
);
1778 if (!right
->map_token
) {
1779 map_extent_buffer(right
, (unsigned long)item
,
1780 sizeof(struct btrfs_item
),
1781 &right
->map_token
, &right
->kaddr
,
1782 &right
->map_start
, &right
->map_len
,
1786 if (path
->slots
[0] == i
)
1787 push_space
+= data_size
+ sizeof(*item
);
1789 this_item_size
= btrfs_item_size(right
, item
);
1790 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
1794 push_space
+= this_item_size
+ sizeof(*item
);
1797 if (right
->map_token
) {
1798 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
1799 right
->map_token
= NULL
;
1802 if (push_items
== 0) {
1803 free_extent_buffer(left
);
1806 if (!empty
&& push_items
== btrfs_header_nritems(right
))
1809 /* push data from right to left */
1810 copy_extent_buffer(left
, right
,
1811 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
1812 btrfs_item_nr_offset(0),
1813 push_items
* sizeof(struct btrfs_item
));
1815 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1816 btrfs_item_offset_nr(right
, push_items
-1);
1818 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
1819 leaf_data_end(root
, left
) - push_space
,
1820 btrfs_leaf_data(right
) +
1821 btrfs_item_offset_nr(right
, push_items
- 1),
1823 old_left_nritems
= btrfs_header_nritems(left
);
1824 BUG_ON(old_left_nritems
< 0);
1826 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
1827 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1830 item
= btrfs_item_nr(left
, i
);
1831 if (!left
->map_token
) {
1832 map_extent_buffer(left
, (unsigned long)item
,
1833 sizeof(struct btrfs_item
),
1834 &left
->map_token
, &left
->kaddr
,
1835 &left
->map_start
, &left
->map_len
,
1839 ioff
= btrfs_item_offset(left
, item
);
1840 btrfs_set_item_offset(left
, item
,
1841 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
));
1843 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
1844 if (left
->map_token
) {
1845 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
1846 left
->map_token
= NULL
;
1849 /* fixup right node */
1850 if (push_items
> right_nritems
) {
1851 printk("push items %d nr %u\n", push_items
, right_nritems
);
1855 if (push_items
< right_nritems
) {
1856 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
1857 leaf_data_end(root
, right
);
1858 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
1859 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1860 btrfs_leaf_data(right
) +
1861 leaf_data_end(root
, right
), push_space
);
1863 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
1864 btrfs_item_nr_offset(push_items
),
1865 (btrfs_header_nritems(right
) - push_items
) *
1866 sizeof(struct btrfs_item
));
1868 right_nritems
-= push_items
;
1869 btrfs_set_header_nritems(right
, right_nritems
);
1870 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1871 for (i
= 0; i
< right_nritems
; i
++) {
1872 item
= btrfs_item_nr(right
, i
);
1874 if (!right
->map_token
) {
1875 map_extent_buffer(right
, (unsigned long)item
,
1876 sizeof(struct btrfs_item
),
1877 &right
->map_token
, &right
->kaddr
,
1878 &right
->map_start
, &right
->map_len
,
1882 push_space
= push_space
- btrfs_item_size(right
, item
);
1883 btrfs_set_item_offset(right
, item
, push_space
);
1885 if (right
->map_token
) {
1886 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
1887 right
->map_token
= NULL
;
1890 btrfs_mark_buffer_dirty(left
);
1892 btrfs_mark_buffer_dirty(right
);
1894 btrfs_item_key(right
, &disk_key
, 0);
1895 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1899 /* then fixup the leaf pointer in the path */
1900 if (path
->slots
[0] < push_items
) {
1901 path
->slots
[0] += old_left_nritems
;
1902 free_extent_buffer(path
->nodes
[0]);
1903 path
->nodes
[0] = left
;
1904 path
->slots
[1] -= 1;
1906 free_extent_buffer(left
);
1907 path
->slots
[0] -= push_items
;
1909 BUG_ON(path
->slots
[0] < 0);
1914 * split the path's leaf in two, making sure there is at least data_size
1915 * available for the resulting leaf level of the path.
1917 * returns 0 if all went well and < 0 on failure.
1919 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1920 *root
, struct btrfs_key
*ins_key
,
1921 struct btrfs_path
*path
, int data_size
, int extend
)
1924 struct extent_buffer
*l
;
1928 struct extent_buffer
*right
;
1929 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1936 int num_doubles
= 0;
1937 struct btrfs_disk_key disk_key
;
1940 space_needed
= data_size
;
1943 root_gen
= trans
->transid
;
1947 /* first try to make some room by pushing left and right */
1948 if (ins_key
->type
!= BTRFS_DIR_ITEM_KEY
) {
1949 wret
= push_leaf_right(trans
, root
, path
, data_size
, 0);
1954 wret
= push_leaf_left(trans
, root
, path
, data_size
, 0);
1960 /* did the pushes work? */
1961 if (btrfs_leaf_free_space(root
, l
) >= space_needed
)
1965 if (!path
->nodes
[1]) {
1966 ret
= insert_new_root(trans
, root
, path
, 1);
1973 slot
= path
->slots
[0];
1974 nritems
= btrfs_header_nritems(l
);
1975 mid
= (nritems
+ 1)/ 2;
1977 btrfs_item_key(l
, &disk_key
, 0);
1979 right
= __btrfs_alloc_free_block(trans
, root
, root
->leafsize
,
1980 root
->root_key
.objectid
,
1981 root_gen
, disk_key
.objectid
, 0,
1984 return PTR_ERR(right
);
1986 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
1987 btrfs_set_header_bytenr(right
, right
->start
);
1988 btrfs_set_header_generation(right
, trans
->transid
);
1989 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
1990 btrfs_set_header_level(right
, 0);
1991 write_extent_buffer(right
, root
->fs_info
->fsid
,
1992 (unsigned long)btrfs_header_fsid(right
),
1996 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1997 BTRFS_LEAF_DATA_SIZE(root
)) {
1998 if (slot
>= nritems
) {
1999 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2000 btrfs_set_header_nritems(right
, 0);
2001 wret
= insert_ptr(trans
, root
, path
,
2002 &disk_key
, right
->start
,
2003 path
->slots
[1] + 1, 1);
2006 free_extent_buffer(path
->nodes
[0]);
2007 path
->nodes
[0] = right
;
2009 path
->slots
[1] += 1;
2013 if (mid
!= nritems
&&
2014 leaf_space_used(l
, mid
, nritems
- mid
) +
2015 space_needed
> BTRFS_LEAF_DATA_SIZE(root
)) {
2020 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
2021 BTRFS_LEAF_DATA_SIZE(root
)) {
2022 if (!extend
&& slot
== 0) {
2023 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2024 btrfs_set_header_nritems(right
, 0);
2025 wret
= insert_ptr(trans
, root
, path
,
2031 free_extent_buffer(path
->nodes
[0]);
2032 path
->nodes
[0] = right
;
2034 if (path
->slots
[1] == 0) {
2035 wret
= fixup_low_keys(trans
, root
,
2036 path
, &disk_key
, 1);
2041 } else if (extend
&& slot
== 0) {
2045 if (mid
!= nritems
&&
2046 leaf_space_used(l
, mid
, nritems
- mid
) +
2047 space_needed
> BTRFS_LEAF_DATA_SIZE(root
)) {
2053 nritems
= nritems
- mid
;
2054 btrfs_set_header_nritems(right
, nritems
);
2055 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
2057 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
2058 btrfs_item_nr_offset(mid
),
2059 nritems
* sizeof(struct btrfs_item
));
2061 copy_extent_buffer(right
, l
,
2062 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
2063 data_copy_size
, btrfs_leaf_data(l
) +
2064 leaf_data_end(root
, l
), data_copy_size
);
2066 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
2067 btrfs_item_end_nr(l
, mid
);
2069 for (i
= 0; i
< nritems
; i
++) {
2070 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
2073 if (!right
->map_token
) {
2074 map_extent_buffer(right
, (unsigned long)item
,
2075 sizeof(struct btrfs_item
),
2076 &right
->map_token
, &right
->kaddr
,
2077 &right
->map_start
, &right
->map_len
,
2081 ioff
= btrfs_item_offset(right
, item
);
2082 btrfs_set_item_offset(right
, item
, ioff
+ rt_data_off
);
2085 if (right
->map_token
) {
2086 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2087 right
->map_token
= NULL
;
2090 btrfs_set_header_nritems(l
, mid
);
2092 btrfs_item_key(right
, &disk_key
, 0);
2093 wret
= insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
2094 path
->slots
[1] + 1, 1);
2098 btrfs_mark_buffer_dirty(right
);
2099 btrfs_mark_buffer_dirty(l
);
2100 BUG_ON(path
->slots
[0] != slot
);
2103 free_extent_buffer(path
->nodes
[0]);
2104 path
->nodes
[0] = right
;
2105 path
->slots
[0] -= mid
;
2106 path
->slots
[1] += 1;
2108 free_extent_buffer(right
);
2110 BUG_ON(path
->slots
[0] < 0);
2113 BUG_ON(num_doubles
!= 0);
2120 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
2121 struct btrfs_root
*root
,
2122 struct btrfs_path
*path
,
2123 u32 new_size
, int from_end
)
2128 struct extent_buffer
*leaf
;
2129 struct btrfs_item
*item
;
2131 unsigned int data_end
;
2132 unsigned int old_data_start
;
2133 unsigned int old_size
;
2134 unsigned int size_diff
;
2137 slot_orig
= path
->slots
[0];
2138 leaf
= path
->nodes
[0];
2139 slot
= path
->slots
[0];
2141 old_size
= btrfs_item_size_nr(leaf
, slot
);
2142 if (old_size
== new_size
)
2145 nritems
= btrfs_header_nritems(leaf
);
2146 data_end
= leaf_data_end(root
, leaf
);
2148 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
2150 size_diff
= old_size
- new_size
;
2153 BUG_ON(slot
>= nritems
);
2156 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2158 /* first correct the data pointers */
2159 for (i
= slot
; i
< nritems
; i
++) {
2161 item
= btrfs_item_nr(leaf
, i
);
2163 if (!leaf
->map_token
) {
2164 map_extent_buffer(leaf
, (unsigned long)item
,
2165 sizeof(struct btrfs_item
),
2166 &leaf
->map_token
, &leaf
->kaddr
,
2167 &leaf
->map_start
, &leaf
->map_len
,
2171 ioff
= btrfs_item_offset(leaf
, item
);
2172 btrfs_set_item_offset(leaf
, item
, ioff
+ size_diff
);
2175 if (leaf
->map_token
) {
2176 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2177 leaf
->map_token
= NULL
;
2180 /* shift the data */
2182 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2183 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
2184 data_end
, old_data_start
+ new_size
- data_end
);
2186 struct btrfs_disk_key disk_key
;
2189 btrfs_item_key(leaf
, &disk_key
, slot
);
2191 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
2193 struct btrfs_file_extent_item
*fi
;
2195 fi
= btrfs_item_ptr(leaf
, slot
,
2196 struct btrfs_file_extent_item
);
2197 fi
= (struct btrfs_file_extent_item
*)(
2198 (unsigned long)fi
- size_diff
);
2200 if (btrfs_file_extent_type(leaf
, fi
) ==
2201 BTRFS_FILE_EXTENT_INLINE
) {
2202 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
2203 memmove_extent_buffer(leaf
, ptr
,
2205 offsetof(struct btrfs_file_extent_item
,
2210 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2211 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
2212 data_end
, old_data_start
- data_end
);
2214 offset
= btrfs_disk_key_offset(&disk_key
);
2215 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
2216 btrfs_set_item_key(leaf
, &disk_key
, slot
);
2218 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2221 item
= btrfs_item_nr(leaf
, slot
);
2222 btrfs_set_item_size(leaf
, item
, new_size
);
2223 btrfs_mark_buffer_dirty(leaf
);
2226 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2227 btrfs_print_leaf(root
, leaf
);
2233 int btrfs_extend_item(struct btrfs_trans_handle
*trans
,
2234 struct btrfs_root
*root
, struct btrfs_path
*path
,
2240 struct extent_buffer
*leaf
;
2241 struct btrfs_item
*item
;
2243 unsigned int data_end
;
2244 unsigned int old_data
;
2245 unsigned int old_size
;
2248 slot_orig
= path
->slots
[0];
2249 leaf
= path
->nodes
[0];
2251 nritems
= btrfs_header_nritems(leaf
);
2252 data_end
= leaf_data_end(root
, leaf
);
2254 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
2255 btrfs_print_leaf(root
, leaf
);
2258 slot
= path
->slots
[0];
2259 old_data
= btrfs_item_end_nr(leaf
, slot
);
2262 if (slot
>= nritems
) {
2263 btrfs_print_leaf(root
, leaf
);
2264 printk("slot %d too large, nritems %d\n", slot
, nritems
);
2269 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2271 /* first correct the data pointers */
2272 for (i
= slot
; i
< nritems
; i
++) {
2274 item
= btrfs_item_nr(leaf
, i
);
2276 if (!leaf
->map_token
) {
2277 map_extent_buffer(leaf
, (unsigned long)item
,
2278 sizeof(struct btrfs_item
),
2279 &leaf
->map_token
, &leaf
->kaddr
,
2280 &leaf
->map_start
, &leaf
->map_len
,
2283 ioff
= btrfs_item_offset(leaf
, item
);
2284 btrfs_set_item_offset(leaf
, item
, ioff
- data_size
);
2287 if (leaf
->map_token
) {
2288 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2289 leaf
->map_token
= NULL
;
2292 /* shift the data */
2293 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2294 data_end
- data_size
, btrfs_leaf_data(leaf
) +
2295 data_end
, old_data
- data_end
);
2297 data_end
= old_data
;
2298 old_size
= btrfs_item_size_nr(leaf
, slot
);
2299 item
= btrfs_item_nr(leaf
, slot
);
2300 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
2301 btrfs_mark_buffer_dirty(leaf
);
2304 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2305 btrfs_print_leaf(root
, leaf
);
2312 * Given a key and some data, insert an item into the tree.
2313 * This does all the path init required, making room in the tree if needed.
2315 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
,
2316 struct btrfs_root
*root
,
2317 struct btrfs_path
*path
,
2318 struct btrfs_key
*cpu_key
, u32 data_size
)
2320 struct extent_buffer
*leaf
;
2321 struct btrfs_item
*item
;
2326 unsigned int data_end
;
2327 struct btrfs_disk_key disk_key
;
2329 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
2331 /* create a root if there isn't one */
2335 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
2342 slot_orig
= path
->slots
[0];
2343 leaf
= path
->nodes
[0];
2345 nritems
= btrfs_header_nritems(leaf
);
2346 data_end
= leaf_data_end(root
, leaf
);
2348 if (btrfs_leaf_free_space(root
, leaf
) <
2349 sizeof(struct btrfs_item
) + data_size
) {
2350 btrfs_print_leaf(root
, leaf
);
2351 printk("not enough freespace need %u have %d\n",
2352 data_size
, btrfs_leaf_free_space(root
, leaf
));
2356 slot
= path
->slots
[0];
2359 if (slot
!= nritems
) {
2361 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
2363 if (old_data
< data_end
) {
2364 btrfs_print_leaf(root
, leaf
);
2365 printk("slot %d old_data %d data_end %d\n",
2366 slot
, old_data
, data_end
);
2370 * item0..itemN ... dataN.offset..dataN.size .. data0.size
2372 /* first correct the data pointers */
2373 WARN_ON(leaf
->map_token
);
2374 for (i
= slot
; i
< nritems
; i
++) {
2377 item
= btrfs_item_nr(leaf
, i
);
2378 if (!leaf
->map_token
) {
2379 map_extent_buffer(leaf
, (unsigned long)item
,
2380 sizeof(struct btrfs_item
),
2381 &leaf
->map_token
, &leaf
->kaddr
,
2382 &leaf
->map_start
, &leaf
->map_len
,
2386 ioff
= btrfs_item_offset(leaf
, item
);
2387 btrfs_set_item_offset(leaf
, item
, ioff
- data_size
);
2389 if (leaf
->map_token
) {
2390 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2391 leaf
->map_token
= NULL
;
2394 /* shift the items */
2395 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ 1),
2396 btrfs_item_nr_offset(slot
),
2397 (nritems
- slot
) * sizeof(struct btrfs_item
));
2399 /* shift the data */
2400 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2401 data_end
- data_size
, btrfs_leaf_data(leaf
) +
2402 data_end
, old_data
- data_end
);
2403 data_end
= old_data
;
2406 /* setup the item for the new data */
2407 btrfs_set_item_key(leaf
, &disk_key
, slot
);
2408 item
= btrfs_item_nr(leaf
, slot
);
2409 btrfs_set_item_offset(leaf
, item
, data_end
- data_size
);
2410 btrfs_set_item_size(leaf
, item
, data_size
);
2411 btrfs_set_header_nritems(leaf
, nritems
+ 1);
2412 btrfs_mark_buffer_dirty(leaf
);
2416 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2418 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
2419 btrfs_print_leaf(root
, leaf
);
2427 * Given a key and some data, insert an item into the tree.
2428 * This does all the path init required, making room in the tree if needed.
2430 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
2431 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
2435 struct btrfs_path
*path
;
2436 struct extent_buffer
*leaf
;
2439 path
= btrfs_alloc_path();
2441 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
2443 leaf
= path
->nodes
[0];
2444 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
2445 write_extent_buffer(leaf
, data
, ptr
, data_size
);
2446 btrfs_mark_buffer_dirty(leaf
);
2448 btrfs_free_path(path
);
2453 * delete the pointer from a given node.
2455 * If the delete empties a node, the node is removed from the tree,
2456 * continuing all the way the root if required. The root is converted into
2457 * a leaf if all the nodes are emptied.
2459 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
2460 struct btrfs_path
*path
, int level
, int slot
)
2462 struct extent_buffer
*parent
= path
->nodes
[level
];
2467 nritems
= btrfs_header_nritems(parent
);
2468 if (slot
!= nritems
-1) {
2469 memmove_extent_buffer(parent
,
2470 btrfs_node_key_ptr_offset(slot
),
2471 btrfs_node_key_ptr_offset(slot
+ 1),
2472 sizeof(struct btrfs_key_ptr
) *
2473 (nritems
- slot
- 1));
2476 btrfs_set_header_nritems(parent
, nritems
);
2477 if (nritems
== 0 && parent
== root
->node
) {
2478 BUG_ON(btrfs_header_level(root
->node
) != 1);
2479 /* just turn the root into a leaf and break */
2480 btrfs_set_header_level(root
->node
, 0);
2481 } else if (slot
== 0) {
2482 struct btrfs_disk_key disk_key
;
2484 btrfs_node_key(parent
, &disk_key
, 0);
2485 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, level
+ 1);
2489 btrfs_mark_buffer_dirty(parent
);
2494 * delete the item at the leaf level in path. If that empties
2495 * the leaf, remove it from the tree
2497 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
2498 struct btrfs_path
*path
)
2501 struct extent_buffer
*leaf
;
2502 struct btrfs_item
*item
;
2509 leaf
= path
->nodes
[0];
2510 slot
= path
->slots
[0];
2511 doff
= btrfs_item_offset_nr(leaf
, slot
);
2512 dsize
= btrfs_item_size_nr(leaf
, slot
);
2513 nritems
= btrfs_header_nritems(leaf
);
2515 if (slot
!= nritems
- 1) {
2517 int data_end
= leaf_data_end(root
, leaf
);
2519 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
2521 btrfs_leaf_data(leaf
) + data_end
,
2524 for (i
= slot
+ 1; i
< nritems
; i
++) {
2527 item
= btrfs_item_nr(leaf
, i
);
2528 if (!leaf
->map_token
) {
2529 map_extent_buffer(leaf
, (unsigned long)item
,
2530 sizeof(struct btrfs_item
),
2531 &leaf
->map_token
, &leaf
->kaddr
,
2532 &leaf
->map_start
, &leaf
->map_len
,
2535 ioff
= btrfs_item_offset(leaf
, item
);
2536 btrfs_set_item_offset(leaf
, item
, ioff
+ dsize
);
2539 if (leaf
->map_token
) {
2540 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
2541 leaf
->map_token
= NULL
;
2544 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
2545 btrfs_item_nr_offset(slot
+ 1),
2546 sizeof(struct btrfs_item
) *
2547 (nritems
- slot
- 1));
2549 btrfs_set_header_nritems(leaf
, nritems
- 1);
2552 /* delete the leaf if we've emptied it */
2554 if (leaf
== root
->node
) {
2555 btrfs_set_header_level(leaf
, 0);
2557 u64 root_gen
= btrfs_header_generation(path
->nodes
[1]);
2558 clean_tree_block(trans
, root
, leaf
);
2559 wait_on_tree_block_writeback(root
, leaf
);
2560 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
2563 wret
= btrfs_free_extent(trans
, root
,
2564 leaf
->start
, leaf
->len
,
2565 btrfs_header_owner(path
->nodes
[1]),
2571 int used
= leaf_space_used(leaf
, 0, nritems
);
2573 struct btrfs_disk_key disk_key
;
2575 btrfs_item_key(leaf
, &disk_key
, 0);
2576 wret
= fixup_low_keys(trans
, root
, path
,
2582 /* delete the leaf if it is mostly empty */
2583 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
2584 /* push_leaf_left fixes the path.
2585 * make sure the path still points to our leaf
2586 * for possible call to del_ptr below
2588 slot
= path
->slots
[1];
2589 extent_buffer_get(leaf
);
2591 wret
= push_leaf_right(trans
, root
, path
, 1, 1);
2592 if (wret
< 0 && wret
!= -ENOSPC
)
2595 if (path
->nodes
[0] == leaf
&&
2596 btrfs_header_nritems(leaf
)) {
2597 wret
= push_leaf_left(trans
, root
, path
, 1, 1);
2598 if (wret
< 0 && wret
!= -ENOSPC
)
2602 if (btrfs_header_nritems(leaf
) == 0) {
2604 u64 bytenr
= leaf
->start
;
2605 u32 blocksize
= leaf
->len
;
2607 root_gen
= btrfs_header_generation(
2610 clean_tree_block(trans
, root
, leaf
);
2611 wait_on_tree_block_writeback(root
, leaf
);
2613 wret
= del_ptr(trans
, root
, path
, 1, slot
);
2617 free_extent_buffer(leaf
);
2618 wret
= btrfs_free_extent(trans
, root
, bytenr
,
2620 btrfs_header_owner(path
->nodes
[1]),
2625 btrfs_mark_buffer_dirty(leaf
);
2626 free_extent_buffer(leaf
);
2629 btrfs_mark_buffer_dirty(leaf
);
2636 * walk up the tree as far as required to find the previous leaf.
2637 * returns 0 if it found something or 1 if there are no lesser leaves.
2638 * returns < 0 on io errors.
2640 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
2645 struct extent_buffer
*c
;
2646 struct extent_buffer
*next
= NULL
;
2648 while(level
< BTRFS_MAX_LEVEL
) {
2649 if (!path
->nodes
[level
])
2652 slot
= path
->slots
[level
];
2653 c
= path
->nodes
[level
];
2656 if (level
== BTRFS_MAX_LEVEL
)
2662 bytenr
= btrfs_node_blockptr(c
, slot
);
2664 free_extent_buffer(next
);
2666 if (path
->reada
< 0)
2667 reada_for_search(root
, path
, level
, slot
);
2669 next
= read_tree_block(root
, bytenr
,
2670 btrfs_level_size(root
, level
- 1));
2673 path
->slots
[level
] = slot
;
2676 c
= path
->nodes
[level
];
2677 free_extent_buffer(c
);
2678 path
->nodes
[level
] = next
;
2679 path
->slots
[level
] = 0;
2683 reada_for_search(root
, path
, level
, 0);
2684 next
= read_tree_block(root
, btrfs_node_blockptr(next
, 0),
2685 btrfs_level_size(root
, level
- 1));
2691 * walk up the tree as far as required to find the next leaf.
2692 * returns 0 if it found something or 1 if there are no greater leaves.
2693 * returns < 0 on io errors.
2695 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
2700 struct extent_buffer
*c
;
2701 struct extent_buffer
*next
= NULL
;
2703 while(level
< BTRFS_MAX_LEVEL
) {
2704 if (!path
->nodes
[level
])
2707 slot
= path
->slots
[level
] + 1;
2708 c
= path
->nodes
[level
];
2709 if (slot
>= btrfs_header_nritems(c
)) {
2711 if (level
== BTRFS_MAX_LEVEL
)
2716 bytenr
= btrfs_node_blockptr(c
, slot
);
2718 free_extent_buffer(next
);
2721 reada_for_search(root
, path
, level
, slot
);
2723 next
= read_tree_block(root
, bytenr
,
2724 btrfs_level_size(root
, level
-1));
2727 path
->slots
[level
] = slot
;
2730 c
= path
->nodes
[level
];
2731 free_extent_buffer(c
);
2732 path
->nodes
[level
] = next
;
2733 path
->slots
[level
] = 0;
2737 reada_for_search(root
, path
, level
, 0);
2738 next
= read_tree_block(root
, btrfs_node_blockptr(next
, 0),
2739 btrfs_level_size(root
, level
- 1));