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
73 struct buffer_head
*cow
;
74 struct btrfs_node
*cow_node
;
77 WARN_ON(!buffer_uptodate(buf
));
78 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
79 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
80 root
->fs_info
->running_transaction
->transid
);
83 if (trans
->transid
!= root
->fs_info
->generation
) {
84 printk(KERN_CRIT
"trans %Lu running %Lu\n", trans
->transid
,
85 root
->fs_info
->generation
);
88 if (btrfs_header_generation(btrfs_buffer_header(buf
)) ==
93 cow
= btrfs_alloc_free_block(trans
, root
, buf
->b_blocknr
);
96 cow_node
= btrfs_buffer_node(cow
);
97 if (buf
->b_size
!= root
->blocksize
|| cow
->b_size
!= root
->blocksize
)
99 memcpy(cow_node
, btrfs_buffer_node(buf
), root
->blocksize
);
100 btrfs_set_header_blocknr(&cow_node
->header
, bh_blocknr(cow
));
101 btrfs_set_header_generation(&cow_node
->header
, trans
->transid
);
102 btrfs_set_header_owner(&cow_node
->header
, root
->root_key
.objectid
);
103 ret
= btrfs_inc_ref(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 btrfs_free_extent(trans
, root
, bh_blocknr(buf
), 1, 1);
119 btrfs_block_release(root
, buf
);
120 btrfs_mark_buffer_dirty(cow
);
126 * The leaf data grows from end-to-front in the node.
127 * this returns the address of the start of the last item,
128 * which is the stop of the leaf data stack
130 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
131 struct btrfs_leaf
*leaf
)
133 u32 nr
= btrfs_header_nritems(&leaf
->header
);
135 return BTRFS_LEAF_DATA_SIZE(root
);
136 return btrfs_item_offset(leaf
->items
+ nr
- 1);
140 * compare two keys in a memcmp fashion
142 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
146 btrfs_disk_key_to_cpu(&k1
, disk
);
148 if (k1
.objectid
> k2
->objectid
)
150 if (k1
.objectid
< k2
->objectid
)
152 if (k1
.flags
> k2
->flags
)
154 if (k1
.flags
< k2
->flags
)
156 if (k1
.offset
> k2
->offset
)
158 if (k1
.offset
< k2
->offset
)
163 static int check_node(struct btrfs_root
*root
, struct btrfs_path
*path
,
166 struct btrfs_node
*parent
= NULL
;
167 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
170 struct btrfs_key cpukey
;
171 u32 nritems
= btrfs_header_nritems(&node
->header
);
173 if (path
->nodes
[level
+ 1])
174 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
176 slot
= path
->slots
[level
];
177 BUG_ON(nritems
== 0);
179 struct btrfs_disk_key
*parent_key
;
181 parent_slot
= path
->slots
[level
+ 1];
182 parent_key
= &parent
->ptrs
[parent_slot
].key
;
183 BUG_ON(memcmp(parent_key
, &node
->ptrs
[0].key
,
184 sizeof(struct btrfs_disk_key
)));
185 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
186 btrfs_header_blocknr(&node
->header
));
188 BUG_ON(nritems
> BTRFS_NODEPTRS_PER_BLOCK(root
));
190 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
- 1].key
);
191 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) <= 0);
193 if (slot
< nritems
- 1) {
194 btrfs_disk_key_to_cpu(&cpukey
, &node
->ptrs
[slot
+ 1].key
);
195 BUG_ON(comp_keys(&node
->ptrs
[slot
].key
, &cpukey
) >= 0);
200 static int check_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
203 struct btrfs_leaf
*leaf
= btrfs_buffer_leaf(path
->nodes
[level
]);
204 struct btrfs_node
*parent
= NULL
;
206 int slot
= path
->slots
[0];
207 struct btrfs_key cpukey
;
209 u32 nritems
= btrfs_header_nritems(&leaf
->header
);
211 if (path
->nodes
[level
+ 1])
212 parent
= btrfs_buffer_node(path
->nodes
[level
+ 1]);
214 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
220 struct btrfs_disk_key
*parent_key
;
222 parent_slot
= path
->slots
[level
+ 1];
223 parent_key
= &parent
->ptrs
[parent_slot
].key
;
224 BUG_ON(memcmp(parent_key
, &leaf
->items
[0].key
,
225 sizeof(struct btrfs_disk_key
)));
226 BUG_ON(btrfs_node_blockptr(parent
, parent_slot
) !=
227 btrfs_header_blocknr(&leaf
->header
));
230 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
- 1].key
);
231 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) <= 0);
232 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
- 1) !=
233 btrfs_item_end(leaf
->items
+ slot
));
235 if (slot
< nritems
- 1) {
236 btrfs_disk_key_to_cpu(&cpukey
, &leaf
->items
[slot
+ 1].key
);
237 BUG_ON(comp_keys(&leaf
->items
[slot
].key
, &cpukey
) >= 0);
238 BUG_ON(btrfs_item_offset(leaf
->items
+ slot
) !=
239 btrfs_item_end(leaf
->items
+ slot
+ 1));
241 BUG_ON(btrfs_item_offset(leaf
->items
) +
242 btrfs_item_size(leaf
->items
) != BTRFS_LEAF_DATA_SIZE(root
));
246 static int check_block(struct btrfs_root
*root
, struct btrfs_path
*path
,
249 struct btrfs_node
*node
= btrfs_buffer_node(path
->nodes
[level
]);
250 if (memcmp(node
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
251 sizeof(node
->header
.fsid
)))
254 return check_leaf(root
, path
, level
);
255 return check_node(root
, path
, level
);
259 * search for key in the array p. items p are item_size apart
260 * and there are 'max' items in p
261 * the slot in the array is returned via slot, and it points to
262 * the place where you would insert key if it is not found in
265 * slot may point to max if the key is bigger than all of the keys
267 static int generic_bin_search(char *p
, int item_size
, struct btrfs_key
*key
,
274 struct btrfs_disk_key
*tmp
;
277 mid
= (low
+ high
) / 2;
278 tmp
= (struct btrfs_disk_key
*)(p
+ mid
* item_size
);
279 ret
= comp_keys(tmp
, key
);
295 * simple bin_search frontend that does the right thing for
298 static int bin_search(struct btrfs_node
*c
, struct btrfs_key
*key
, int *slot
)
300 if (btrfs_is_leaf(c
)) {
301 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
302 return generic_bin_search((void *)l
->items
,
303 sizeof(struct btrfs_item
),
304 key
, btrfs_header_nritems(&c
->header
),
307 return generic_bin_search((void *)c
->ptrs
,
308 sizeof(struct btrfs_key_ptr
),
309 key
, btrfs_header_nritems(&c
->header
),
315 static struct buffer_head
*read_node_slot(struct btrfs_root
*root
,
316 struct buffer_head
*parent_buf
,
319 struct btrfs_node
*node
= btrfs_buffer_node(parent_buf
);
322 if (slot
>= btrfs_header_nritems(&node
->header
))
324 return read_tree_block(root
, btrfs_node_blockptr(node
, slot
));
327 static int balance_level(struct btrfs_trans_handle
*trans
, struct btrfs_root
328 *root
, struct btrfs_path
*path
, int level
)
330 struct buffer_head
*right_buf
;
331 struct buffer_head
*mid_buf
;
332 struct buffer_head
*left_buf
;
333 struct buffer_head
*parent_buf
= NULL
;
334 struct btrfs_node
*right
= NULL
;
335 struct btrfs_node
*mid
;
336 struct btrfs_node
*left
= NULL
;
337 struct btrfs_node
*parent
= NULL
;
341 int orig_slot
= path
->slots
[level
];
342 int err_on_enospc
= 0;
348 mid_buf
= path
->nodes
[level
];
349 mid
= btrfs_buffer_node(mid_buf
);
350 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
352 if (level
< BTRFS_MAX_LEVEL
- 1)
353 parent_buf
= path
->nodes
[level
+ 1];
354 pslot
= path
->slots
[level
+ 1];
357 * deal with the case where there is only one pointer in the root
358 * by promoting the node below to a root
361 struct buffer_head
*child
;
362 u64 blocknr
= bh_blocknr(mid_buf
);
364 if (btrfs_header_nritems(&mid
->header
) != 1)
367 /* promote the child to a root */
368 child
= read_node_slot(root
, mid_buf
, 0);
371 path
->nodes
[level
] = NULL
;
372 clean_tree_block(trans
, root
, mid_buf
);
373 wait_on_buffer(mid_buf
);
374 /* once for the path */
375 btrfs_block_release(root
, mid_buf
);
376 /* once for the root ptr */
377 btrfs_block_release(root
, mid_buf
);
378 return btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
380 parent
= btrfs_buffer_node(parent_buf
);
382 if (btrfs_header_nritems(&mid
->header
) >
383 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
386 if (btrfs_header_nritems(&mid
->header
) < 2)
389 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
390 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
392 /* first, try to make some room in the middle buffer */
394 wret
= btrfs_cow_block(trans
, root
, left_buf
,
395 parent_buf
, pslot
- 1, &left_buf
);
400 left
= btrfs_buffer_node(left_buf
);
401 orig_slot
+= btrfs_header_nritems(&left
->header
);
402 wret
= push_node_left(trans
, root
, left_buf
, mid_buf
);
405 if (btrfs_header_nritems(&mid
->header
) < 2)
410 * then try to empty the right most buffer into the middle
413 wret
= btrfs_cow_block(trans
, root
, right_buf
,
414 parent_buf
, pslot
+ 1, &right_buf
);
420 right
= btrfs_buffer_node(right_buf
);
421 wret
= push_node_left(trans
, root
, mid_buf
, right_buf
);
422 if (wret
< 0 && wret
!= -ENOSPC
)
424 if (btrfs_header_nritems(&right
->header
) == 0) {
425 u64 blocknr
= bh_blocknr(right_buf
);
426 clean_tree_block(trans
, root
, right_buf
);
427 wait_on_buffer(right_buf
);
428 btrfs_block_release(root
, right_buf
);
431 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
435 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
439 btrfs_memcpy(root
, parent
,
440 &parent
->ptrs
[pslot
+ 1].key
,
442 sizeof(struct btrfs_disk_key
));
443 btrfs_mark_buffer_dirty(parent_buf
);
446 if (btrfs_header_nritems(&mid
->header
) == 1) {
448 * we're not allowed to leave a node with one item in the
449 * tree during a delete. A deletion from lower in the tree
450 * could try to delete the only pointer in this node.
451 * So, pull some keys from the left.
452 * There has to be a left pointer at this point because
453 * otherwise we would have pulled some pointers from the
457 wret
= balance_node_right(trans
, root
, mid_buf
, left_buf
);
464 if (btrfs_header_nritems(&mid
->header
) == 0) {
465 /* we've managed to empty the middle node, drop it */
466 u64 blocknr
= bh_blocknr(mid_buf
);
467 clean_tree_block(trans
, root
, mid_buf
);
468 wait_on_buffer(mid_buf
);
469 btrfs_block_release(root
, mid_buf
);
472 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
475 wret
= btrfs_free_extent(trans
, root
, blocknr
, 1, 1);
479 /* update the parent key to reflect our changes */
480 btrfs_memcpy(root
, parent
,
481 &parent
->ptrs
[pslot
].key
, &mid
->ptrs
[0].key
,
482 sizeof(struct btrfs_disk_key
));
483 btrfs_mark_buffer_dirty(parent_buf
);
486 /* update the path */
488 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
490 path
->nodes
[level
] = left_buf
;
491 path
->slots
[level
+ 1] -= 1;
492 path
->slots
[level
] = orig_slot
;
494 btrfs_block_release(root
, mid_buf
);
496 orig_slot
-= btrfs_header_nritems(&left
->header
);
497 path
->slots
[level
] = orig_slot
;
500 /* double check we haven't messed things up */
501 check_block(root
, path
, level
);
503 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[level
]),
508 btrfs_block_release(root
, right_buf
);
510 btrfs_block_release(root
, left_buf
);
514 /* returns zero if the push worked, non-zero otherwise */
515 static int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
516 struct btrfs_root
*root
,
517 struct btrfs_path
*path
, int level
)
519 struct buffer_head
*right_buf
;
520 struct buffer_head
*mid_buf
;
521 struct buffer_head
*left_buf
;
522 struct buffer_head
*parent_buf
= NULL
;
523 struct btrfs_node
*right
= NULL
;
524 struct btrfs_node
*mid
;
525 struct btrfs_node
*left
= NULL
;
526 struct btrfs_node
*parent
= NULL
;
530 int orig_slot
= path
->slots
[level
];
536 mid_buf
= path
->nodes
[level
];
537 mid
= btrfs_buffer_node(mid_buf
);
538 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
540 if (level
< BTRFS_MAX_LEVEL
- 1)
541 parent_buf
= path
->nodes
[level
+ 1];
542 pslot
= path
->slots
[level
+ 1];
546 parent
= btrfs_buffer_node(parent_buf
);
548 left_buf
= read_node_slot(root
, parent_buf
, pslot
- 1);
550 /* first, try to make some room in the middle buffer */
553 left
= btrfs_buffer_node(left_buf
);
554 left_nr
= btrfs_header_nritems(&left
->header
);
555 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
558 ret
= btrfs_cow_block(trans
, root
, left_buf
, parent_buf
,
559 pslot
- 1, &left_buf
);
563 left
= btrfs_buffer_node(left_buf
);
564 wret
= push_node_left(trans
, root
,
571 orig_slot
+= left_nr
;
572 btrfs_memcpy(root
, parent
,
573 &parent
->ptrs
[pslot
].key
,
575 sizeof(struct btrfs_disk_key
));
576 btrfs_mark_buffer_dirty(parent_buf
);
577 if (btrfs_header_nritems(&left
->header
) > orig_slot
) {
578 path
->nodes
[level
] = left_buf
;
579 path
->slots
[level
+ 1] -= 1;
580 path
->slots
[level
] = orig_slot
;
581 btrfs_block_release(root
, mid_buf
);
584 btrfs_header_nritems(&left
->header
);
585 path
->slots
[level
] = orig_slot
;
586 btrfs_block_release(root
, left_buf
);
588 check_node(root
, path
, level
);
591 btrfs_block_release(root
, left_buf
);
593 right_buf
= read_node_slot(root
, parent_buf
, pslot
+ 1);
596 * then try to empty the right most buffer into the middle
600 right
= btrfs_buffer_node(right_buf
);
601 right_nr
= btrfs_header_nritems(&right
->header
);
602 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
605 ret
= btrfs_cow_block(trans
, root
, right_buf
,
606 parent_buf
, pslot
+ 1,
611 right
= btrfs_buffer_node(right_buf
);
612 wret
= balance_node_right(trans
, root
,
619 btrfs_memcpy(root
, parent
,
620 &parent
->ptrs
[pslot
+ 1].key
,
622 sizeof(struct btrfs_disk_key
));
623 btrfs_mark_buffer_dirty(parent_buf
);
624 if (btrfs_header_nritems(&mid
->header
) <= orig_slot
) {
625 path
->nodes
[level
] = right_buf
;
626 path
->slots
[level
+ 1] += 1;
627 path
->slots
[level
] = orig_slot
-
628 btrfs_header_nritems(&mid
->header
);
629 btrfs_block_release(root
, mid_buf
);
631 btrfs_block_release(root
, right_buf
);
633 check_node(root
, path
, level
);
636 btrfs_block_release(root
, right_buf
);
638 check_node(root
, path
, level
);
643 * look for key in the tree. path is filled in with nodes along the way
644 * if key is found, we return zero and you can find the item in the leaf
645 * level of the path (level 0)
647 * If the key isn't found, the path points to the slot where it should
648 * be inserted, and 1 is returned. If there are other errors during the
649 * search a negative error number is returned.
651 * if ins_len > 0, nodes and leaves will be split as we walk down the
652 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
655 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
656 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
659 struct buffer_head
*b
;
660 struct buffer_head
*cow_buf
;
661 struct btrfs_node
*c
;
666 WARN_ON(p
->nodes
[0] != NULL
);
667 WARN_ON(!mutex_is_locked(&root
->fs_info
->fs_mutex
));
672 c
= btrfs_buffer_node(b
);
673 level
= btrfs_header_level(&c
->header
);
676 wret
= btrfs_cow_block(trans
, root
, b
,
681 btrfs_block_release(root
, cow_buf
);
685 c
= btrfs_buffer_node(b
);
687 BUG_ON(!cow
&& ins_len
);
688 if (level
!= btrfs_header_level(&c
->header
))
690 level
= btrfs_header_level(&c
->header
);
692 ret
= check_block(root
, p
, level
);
695 ret
= bin_search(c
, key
, &slot
);
696 if (!btrfs_is_leaf(c
)) {
699 p
->slots
[level
] = slot
;
700 if (ins_len
> 0 && btrfs_header_nritems(&c
->header
) >=
701 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
702 int sret
= split_node(trans
, root
, p
, level
);
707 c
= btrfs_buffer_node(b
);
708 slot
= p
->slots
[level
];
709 } else if (ins_len
< 0) {
710 int sret
= balance_level(trans
, root
, p
,
717 c
= btrfs_buffer_node(b
);
718 slot
= p
->slots
[level
];
719 BUG_ON(btrfs_header_nritems(&c
->header
) == 1);
721 b
= read_tree_block(root
, btrfs_node_blockptr(c
, slot
));
723 struct btrfs_leaf
*l
= (struct btrfs_leaf
*)c
;
724 p
->slots
[level
] = slot
;
725 if (ins_len
> 0 && btrfs_leaf_free_space(root
, l
) <
726 sizeof(struct btrfs_item
) + ins_len
) {
727 int sret
= split_leaf(trans
, root
, key
,
740 * adjust the pointers going up the tree, starting at level
741 * making sure the right key of each node is points to 'key'.
742 * This is used after shifting pointers to the left, so it stops
743 * fixing up pointers when a given leaf/node is not in slot 0 of the
746 * If this fails to write a tree block, it returns -1, but continues
747 * fixing up the blocks in ram so the tree is consistent.
749 static int fixup_low_keys(struct btrfs_trans_handle
*trans
, struct btrfs_root
750 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
755 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
756 struct btrfs_node
*t
;
757 int tslot
= path
->slots
[i
];
760 t
= btrfs_buffer_node(path
->nodes
[i
]);
761 btrfs_memcpy(root
, t
, &t
->ptrs
[tslot
].key
, key
, sizeof(*key
));
762 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
770 * try to push data from one node into the next node left in the
773 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
774 * error, and > 0 if there was no room in the left hand block.
776 static int push_node_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
777 *root
, struct buffer_head
*dst_buf
, struct
778 buffer_head
*src_buf
)
780 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
781 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
787 src_nritems
= btrfs_header_nritems(&src
->header
);
788 dst_nritems
= btrfs_header_nritems(&dst
->header
);
789 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
791 if (push_items
<= 0) {
795 if (src_nritems
< push_items
)
796 push_items
= src_nritems
;
798 btrfs_memcpy(root
, dst
, dst
->ptrs
+ dst_nritems
, src
->ptrs
,
799 push_items
* sizeof(struct btrfs_key_ptr
));
800 if (push_items
< src_nritems
) {
801 btrfs_memmove(root
, src
, src
->ptrs
, src
->ptrs
+ push_items
,
802 (src_nritems
- push_items
) *
803 sizeof(struct btrfs_key_ptr
));
805 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
806 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
807 btrfs_mark_buffer_dirty(src_buf
);
808 btrfs_mark_buffer_dirty(dst_buf
);
813 * try to push data from one node into the next node right in the
816 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
817 * error, and > 0 if there was no room in the right hand block.
819 * this will only push up to 1/2 the contents of the left node over
821 static int balance_node_right(struct btrfs_trans_handle
*trans
, struct
822 btrfs_root
*root
, struct buffer_head
*dst_buf
,
823 struct buffer_head
*src_buf
)
825 struct btrfs_node
*src
= btrfs_buffer_node(src_buf
);
826 struct btrfs_node
*dst
= btrfs_buffer_node(dst_buf
);
833 src_nritems
= btrfs_header_nritems(&src
->header
);
834 dst_nritems
= btrfs_header_nritems(&dst
->header
);
835 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
836 if (push_items
<= 0) {
840 max_push
= src_nritems
/ 2 + 1;
841 /* don't try to empty the node */
842 if (max_push
> src_nritems
)
844 if (max_push
< push_items
)
845 push_items
= max_push
;
847 btrfs_memmove(root
, dst
, dst
->ptrs
+ push_items
, dst
->ptrs
,
848 dst_nritems
* sizeof(struct btrfs_key_ptr
));
850 btrfs_memcpy(root
, dst
, dst
->ptrs
,
851 src
->ptrs
+ src_nritems
- push_items
,
852 push_items
* sizeof(struct btrfs_key_ptr
));
854 btrfs_set_header_nritems(&src
->header
, src_nritems
- push_items
);
855 btrfs_set_header_nritems(&dst
->header
, dst_nritems
+ push_items
);
857 btrfs_mark_buffer_dirty(src_buf
);
858 btrfs_mark_buffer_dirty(dst_buf
);
863 * helper function to insert a new root level in the tree.
864 * A new node is allocated, and a single item is inserted to
865 * point to the existing root
867 * returns zero on success or < 0 on failure.
869 static int insert_new_root(struct btrfs_trans_handle
*trans
, struct btrfs_root
870 *root
, struct btrfs_path
*path
, int level
)
872 struct buffer_head
*t
;
873 struct btrfs_node
*lower
;
874 struct btrfs_node
*c
;
875 struct btrfs_disk_key
*lower_key
;
877 BUG_ON(path
->nodes
[level
]);
878 BUG_ON(path
->nodes
[level
-1] != root
->node
);
880 t
= btrfs_alloc_free_block(trans
, root
, root
->node
->b_blocknr
);
883 c
= btrfs_buffer_node(t
);
884 memset(c
, 0, root
->blocksize
);
885 btrfs_set_header_nritems(&c
->header
, 1);
886 btrfs_set_header_level(&c
->header
, level
);
887 btrfs_set_header_blocknr(&c
->header
, bh_blocknr(t
));
888 btrfs_set_header_generation(&c
->header
, trans
->transid
);
889 btrfs_set_header_owner(&c
->header
, root
->root_key
.objectid
);
890 lower
= btrfs_buffer_node(path
->nodes
[level
-1]);
891 memcpy(c
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
892 sizeof(c
->header
.fsid
));
893 if (btrfs_is_leaf(lower
))
894 lower_key
= &((struct btrfs_leaf
*)lower
)->items
[0].key
;
896 lower_key
= &lower
->ptrs
[0].key
;
897 btrfs_memcpy(root
, c
, &c
->ptrs
[0].key
, lower_key
,
898 sizeof(struct btrfs_disk_key
));
899 btrfs_set_node_blockptr(c
, 0, bh_blocknr(path
->nodes
[level
- 1]));
901 btrfs_mark_buffer_dirty(t
);
903 /* the super has an extra ref to root->node */
904 btrfs_block_release(root
, root
->node
);
907 path
->nodes
[level
] = t
;
908 path
->slots
[level
] = 0;
913 * worker function to insert a single pointer in a node.
914 * the node should have enough room for the pointer already
916 * slot and level indicate where you want the key to go, and
917 * blocknr is the block the key points to.
919 * returns zero on success and < 0 on any error
921 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
922 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
923 *key
, u64 blocknr
, int slot
, int level
)
925 struct btrfs_node
*lower
;
928 BUG_ON(!path
->nodes
[level
]);
929 lower
= btrfs_buffer_node(path
->nodes
[level
]);
930 nritems
= btrfs_header_nritems(&lower
->header
);
933 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
935 if (slot
!= nritems
) {
936 btrfs_memmove(root
, lower
, lower
->ptrs
+ slot
+ 1,
938 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
940 btrfs_memcpy(root
, lower
, &lower
->ptrs
[slot
].key
,
941 key
, sizeof(struct btrfs_disk_key
));
942 btrfs_set_node_blockptr(lower
, slot
, blocknr
);
943 btrfs_set_header_nritems(&lower
->header
, nritems
+ 1);
944 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
945 check_node(root
, path
, level
);
950 * split the node at the specified level in path in two.
951 * The path is corrected to point to the appropriate node after the split
953 * Before splitting this tries to make some room in the node by pushing
954 * left and right, if either one works, it returns right away.
956 * returns 0 on success and < 0 on failure
958 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
959 *root
, struct btrfs_path
*path
, int level
)
961 struct buffer_head
*t
;
962 struct btrfs_node
*c
;
963 struct buffer_head
*split_buffer
;
964 struct btrfs_node
*split
;
970 t
= path
->nodes
[level
];
971 c
= btrfs_buffer_node(t
);
972 if (t
== root
->node
) {
973 /* trying to split the root, lets make a new one */
974 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
978 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
979 t
= path
->nodes
[level
];
980 c
= btrfs_buffer_node(t
);
982 btrfs_header_nritems(&c
->header
) <
983 BTRFS_NODEPTRS_PER_BLOCK(root
) - 1)
989 c_nritems
= btrfs_header_nritems(&c
->header
);
990 split_buffer
= btrfs_alloc_free_block(trans
, root
, t
->b_blocknr
);
991 if (IS_ERR(split_buffer
))
992 return PTR_ERR(split_buffer
);
994 split
= btrfs_buffer_node(split_buffer
);
995 btrfs_set_header_flags(&split
->header
, btrfs_header_flags(&c
->header
));
996 btrfs_set_header_level(&split
->header
, btrfs_header_level(&c
->header
));
997 btrfs_set_header_blocknr(&split
->header
, bh_blocknr(split_buffer
));
998 btrfs_set_header_generation(&split
->header
, trans
->transid
);
999 btrfs_set_header_owner(&split
->header
, root
->root_key
.objectid
);
1000 memcpy(split
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1001 sizeof(split
->header
.fsid
));
1002 mid
= (c_nritems
+ 1) / 2;
1003 btrfs_memcpy(root
, split
, split
->ptrs
, c
->ptrs
+ mid
,
1004 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
1005 btrfs_set_header_nritems(&split
->header
, c_nritems
- mid
);
1006 btrfs_set_header_nritems(&c
->header
, mid
);
1009 btrfs_mark_buffer_dirty(t
);
1010 btrfs_mark_buffer_dirty(split_buffer
);
1011 wret
= insert_ptr(trans
, root
, path
, &split
->ptrs
[0].key
,
1012 bh_blocknr(split_buffer
), path
->slots
[level
+ 1] + 1,
1017 if (path
->slots
[level
] >= mid
) {
1018 path
->slots
[level
] -= mid
;
1019 btrfs_block_release(root
, t
);
1020 path
->nodes
[level
] = split_buffer
;
1021 path
->slots
[level
+ 1] += 1;
1023 btrfs_block_release(root
, split_buffer
);
1029 * how many bytes are required to store the items in a leaf. start
1030 * and nr indicate which items in the leaf to check. This totals up the
1031 * space used both by the item structs and the item data
1033 static int leaf_space_used(struct btrfs_leaf
*l
, int start
, int nr
)
1036 int nritems
= btrfs_header_nritems(&l
->header
);
1037 int end
= min(nritems
, start
+ nr
) - 1;
1041 data_len
= btrfs_item_end(l
->items
+ start
);
1042 data_len
= data_len
- btrfs_item_offset(l
->items
+ end
);
1043 data_len
+= sizeof(struct btrfs_item
) * nr
;
1044 WARN_ON(data_len
< 0);
1049 * The space between the end of the leaf items and
1050 * the start of the leaf data. IOW, how much room
1051 * the leaf has left for both items and data
1053 int btrfs_leaf_free_space(struct btrfs_root
*root
, struct btrfs_leaf
*leaf
)
1055 int nritems
= btrfs_header_nritems(&leaf
->header
);
1056 return BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
1060 * push some data in the path leaf to the right, trying to free up at
1061 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1063 * returns 1 if the push failed because the other node didn't have enough
1064 * room, 0 if everything worked out and < 0 if there were major errors.
1066 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
1067 *root
, struct btrfs_path
*path
, int data_size
)
1069 struct buffer_head
*left_buf
= path
->nodes
[0];
1070 struct btrfs_leaf
*left
= btrfs_buffer_leaf(left_buf
);
1071 struct btrfs_leaf
*right
;
1072 struct buffer_head
*right_buf
;
1073 struct buffer_head
*upper
;
1074 struct btrfs_node
*upper_node
;
1080 struct btrfs_item
*item
;
1085 slot
= path
->slots
[1];
1086 if (!path
->nodes
[1]) {
1089 upper
= path
->nodes
[1];
1090 upper_node
= btrfs_buffer_node(upper
);
1091 if (slot
>= btrfs_header_nritems(&upper_node
->header
) - 1) {
1094 right_buf
= read_tree_block(root
,
1095 btrfs_node_blockptr(btrfs_buffer_node(upper
), slot
+ 1));
1096 right
= btrfs_buffer_leaf(right_buf
);
1097 free_space
= btrfs_leaf_free_space(root
, right
);
1098 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1099 btrfs_block_release(root
, right_buf
);
1102 /* cow and double check */
1103 ret
= btrfs_cow_block(trans
, root
, right_buf
, upper
,
1104 slot
+ 1, &right_buf
);
1106 btrfs_block_release(root
, right_buf
);
1109 right
= btrfs_buffer_leaf(right_buf
);
1110 free_space
= btrfs_leaf_free_space(root
, right
);
1111 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1112 btrfs_block_release(root
, right_buf
);
1116 left_nritems
= btrfs_header_nritems(&left
->header
);
1117 if (left_nritems
== 0) {
1118 btrfs_block_release(root
, right_buf
);
1121 for (i
= left_nritems
- 1; i
>= 1; i
--) {
1122 item
= left
->items
+ i
;
1123 if (path
->slots
[0] == i
)
1124 push_space
+= data_size
+ sizeof(*item
);
1125 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1129 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1131 if (push_items
== 0) {
1132 btrfs_block_release(root
, right_buf
);
1135 if (push_items
== left_nritems
)
1137 right_nritems
= btrfs_header_nritems(&right
->header
);
1138 /* push left to right */
1139 push_space
= btrfs_item_end(left
->items
+ left_nritems
- push_items
);
1140 push_space
-= leaf_data_end(root
, left
);
1141 /* make room in the right data area */
1142 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1143 leaf_data_end(root
, right
) - push_space
,
1144 btrfs_leaf_data(right
) +
1145 leaf_data_end(root
, right
), BTRFS_LEAF_DATA_SIZE(root
) -
1146 leaf_data_end(root
, right
));
1147 /* copy from the left data area */
1148 btrfs_memcpy(root
, right
, btrfs_leaf_data(right
) +
1149 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1150 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
1152 btrfs_memmove(root
, right
, right
->items
+ push_items
, right
->items
,
1153 right_nritems
* sizeof(struct btrfs_item
));
1154 /* copy the items from left to right */
1155 btrfs_memcpy(root
, right
, right
->items
, left
->items
+
1156 left_nritems
- push_items
,
1157 push_items
* sizeof(struct btrfs_item
));
1159 /* update the item pointers */
1160 right_nritems
+= push_items
;
1161 btrfs_set_header_nritems(&right
->header
, right_nritems
);
1162 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1163 for (i
= 0; i
< right_nritems
; i
++) {
1164 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1165 btrfs_item_size(right
->items
+ i
));
1166 push_space
= btrfs_item_offset(right
->items
+ i
);
1168 left_nritems
-= push_items
;
1169 btrfs_set_header_nritems(&left
->header
, left_nritems
);
1171 btrfs_mark_buffer_dirty(left_buf
);
1172 btrfs_mark_buffer_dirty(right_buf
);
1174 btrfs_memcpy(root
, upper_node
, &upper_node
->ptrs
[slot
+ 1].key
,
1175 &right
->items
[0].key
, sizeof(struct btrfs_disk_key
));
1176 btrfs_mark_buffer_dirty(upper
);
1178 /* then fixup the leaf pointer in the path */
1179 if (path
->slots
[0] >= left_nritems
) {
1180 path
->slots
[0] -= left_nritems
;
1181 btrfs_block_release(root
, path
->nodes
[0]);
1182 path
->nodes
[0] = right_buf
;
1183 path
->slots
[1] += 1;
1185 btrfs_block_release(root
, right_buf
);
1188 check_node(root
, path
, 1);
1192 * push some data in the path leaf to the left, trying to free up at
1193 * least data_size bytes. returns zero if the push worked, nonzero otherwise
1195 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
1196 *root
, struct btrfs_path
*path
, int data_size
)
1198 struct buffer_head
*right_buf
= path
->nodes
[0];
1199 struct btrfs_leaf
*right
= btrfs_buffer_leaf(right_buf
);
1200 struct buffer_head
*t
;
1201 struct btrfs_leaf
*left
;
1207 struct btrfs_item
*item
;
1208 u32 old_left_nritems
;
1212 slot
= path
->slots
[1];
1216 if (!path
->nodes
[1]) {
1219 t
= read_tree_block(root
,
1220 btrfs_node_blockptr(btrfs_buffer_node(path
->nodes
[1]), slot
- 1));
1221 left
= btrfs_buffer_leaf(t
);
1222 free_space
= btrfs_leaf_free_space(root
, left
);
1223 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1224 btrfs_block_release(root
, t
);
1228 /* cow and double check */
1229 ret
= btrfs_cow_block(trans
, root
, t
, path
->nodes
[1], slot
- 1, &t
);
1231 /* we hit -ENOSPC, but it isn't fatal here */
1234 left
= btrfs_buffer_leaf(t
);
1235 free_space
= btrfs_leaf_free_space(root
, left
);
1236 if (free_space
< data_size
+ sizeof(struct btrfs_item
)) {
1237 btrfs_block_release(root
, t
);
1241 if (btrfs_header_nritems(&right
->header
) == 0) {
1242 btrfs_block_release(root
, t
);
1246 for (i
= 0; i
< btrfs_header_nritems(&right
->header
) - 1; i
++) {
1247 item
= right
->items
+ i
;
1248 if (path
->slots
[0] == i
)
1249 push_space
+= data_size
+ sizeof(*item
);
1250 if (btrfs_item_size(item
) + sizeof(*item
) + push_space
>
1254 push_space
+= btrfs_item_size(item
) + sizeof(*item
);
1256 if (push_items
== 0) {
1257 btrfs_block_release(root
, t
);
1260 if (push_items
== btrfs_header_nritems(&right
->header
))
1262 /* push data from right to left */
1263 btrfs_memcpy(root
, left
, left
->items
+
1264 btrfs_header_nritems(&left
->header
),
1265 right
->items
, push_items
* sizeof(struct btrfs_item
));
1266 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
1267 btrfs_item_offset(right
->items
+ push_items
-1);
1268 btrfs_memcpy(root
, left
, btrfs_leaf_data(left
) +
1269 leaf_data_end(root
, left
) - push_space
,
1270 btrfs_leaf_data(right
) +
1271 btrfs_item_offset(right
->items
+ push_items
- 1),
1273 old_left_nritems
= btrfs_header_nritems(&left
->header
);
1274 BUG_ON(old_left_nritems
< 0);
1276 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
1277 u32 ioff
= btrfs_item_offset(left
->items
+ i
);
1278 btrfs_set_item_offset(left
->items
+ i
, ioff
-
1279 (BTRFS_LEAF_DATA_SIZE(root
) -
1280 btrfs_item_offset(left
->items
+
1281 old_left_nritems
- 1)));
1283 btrfs_set_header_nritems(&left
->header
, old_left_nritems
+ push_items
);
1285 /* fixup right node */
1286 push_space
= btrfs_item_offset(right
->items
+ push_items
- 1) -
1287 leaf_data_end(root
, right
);
1288 btrfs_memmove(root
, right
, btrfs_leaf_data(right
) +
1289 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
1290 btrfs_leaf_data(right
) +
1291 leaf_data_end(root
, right
), push_space
);
1292 btrfs_memmove(root
, right
, right
->items
, right
->items
+ push_items
,
1293 (btrfs_header_nritems(&right
->header
) - push_items
) *
1294 sizeof(struct btrfs_item
));
1295 btrfs_set_header_nritems(&right
->header
,
1296 btrfs_header_nritems(&right
->header
) -
1298 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
1300 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1301 btrfs_set_item_offset(right
->items
+ i
, push_space
-
1302 btrfs_item_size(right
->items
+ i
));
1303 push_space
= btrfs_item_offset(right
->items
+ i
);
1306 btrfs_mark_buffer_dirty(t
);
1307 btrfs_mark_buffer_dirty(right_buf
);
1309 wret
= fixup_low_keys(trans
, root
, path
, &right
->items
[0].key
, 1);
1313 /* then fixup the leaf pointer in the path */
1314 if (path
->slots
[0] < push_items
) {
1315 path
->slots
[0] += old_left_nritems
;
1316 btrfs_block_release(root
, path
->nodes
[0]);
1318 path
->slots
[1] -= 1;
1320 btrfs_block_release(root
, t
);
1321 path
->slots
[0] -= push_items
;
1323 BUG_ON(path
->slots
[0] < 0);
1325 check_node(root
, path
, 1);
1330 * split the path's leaf in two, making sure there is at least data_size
1331 * available for the resulting leaf level of the path.
1333 * returns 0 if all went well and < 0 on failure.
1335 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
1336 *root
, struct btrfs_key
*ins_key
,
1337 struct btrfs_path
*path
, int data_size
)
1339 struct buffer_head
*l_buf
;
1340 struct btrfs_leaf
*l
;
1344 struct btrfs_leaf
*right
;
1345 struct buffer_head
*right_buffer
;
1346 int space_needed
= data_size
+ sizeof(struct btrfs_item
);
1352 int double_split
= 0;
1353 struct btrfs_disk_key disk_key
;
1355 /* first try to make some room by pushing left and right */
1356 wret
= push_leaf_left(trans
, root
, path
, data_size
);
1360 wret
= push_leaf_right(trans
, root
, path
, data_size
);
1364 l_buf
= path
->nodes
[0];
1365 l
= btrfs_buffer_leaf(l_buf
);
1367 /* did the pushes work? */
1368 if (btrfs_leaf_free_space(root
, l
) >=
1369 sizeof(struct btrfs_item
) + data_size
)
1372 if (!path
->nodes
[1]) {
1373 ret
= insert_new_root(trans
, root
, path
, 1);
1377 slot
= path
->slots
[0];
1378 nritems
= btrfs_header_nritems(&l
->header
);
1379 mid
= (nritems
+ 1)/ 2;
1381 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1382 if (IS_ERR(right_buffer
))
1383 return PTR_ERR(right_buffer
);
1385 right
= btrfs_buffer_leaf(right_buffer
);
1386 memset(&right
->header
, 0, sizeof(right
->header
));
1387 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1388 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1389 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1390 btrfs_set_header_level(&right
->header
, 0);
1391 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1392 sizeof(right
->header
.fsid
));
1395 leaf_space_used(l
, mid
, nritems
- mid
) + space_needed
>
1396 BTRFS_LEAF_DATA_SIZE(root
)) {
1397 if (slot
>= nritems
) {
1398 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1399 btrfs_set_header_nritems(&right
->header
, 0);
1400 wret
= insert_ptr(trans
, root
, path
,
1402 bh_blocknr(right_buffer
),
1403 path
->slots
[1] + 1, 1);
1406 btrfs_block_release(root
, path
->nodes
[0]);
1407 path
->nodes
[0] = right_buffer
;
1409 path
->slots
[1] += 1;
1416 if (leaf_space_used(l
, 0, mid
+ 1) + space_needed
>
1417 BTRFS_LEAF_DATA_SIZE(root
)) {
1419 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1420 btrfs_set_header_nritems(&right
->header
, 0);
1421 wret
= insert_ptr(trans
, root
, path
,
1423 bh_blocknr(right_buffer
),
1427 btrfs_block_release(root
, path
->nodes
[0]);
1428 path
->nodes
[0] = right_buffer
;
1430 if (path
->slots
[1] == 0) {
1431 wret
= fixup_low_keys(trans
, root
,
1432 path
, &disk_key
, 1);
1442 btrfs_set_header_nritems(&right
->header
, nritems
- mid
);
1443 data_copy_size
= btrfs_item_end(l
->items
+ mid
) -
1444 leaf_data_end(root
, l
);
1445 btrfs_memcpy(root
, right
, right
->items
, l
->items
+ mid
,
1446 (nritems
- mid
) * sizeof(struct btrfs_item
));
1447 btrfs_memcpy(root
, right
,
1448 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
1449 data_copy_size
, btrfs_leaf_data(l
) +
1450 leaf_data_end(root
, l
), data_copy_size
);
1451 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
1452 btrfs_item_end(l
->items
+ mid
);
1454 for (i
= 0; i
< btrfs_header_nritems(&right
->header
); i
++) {
1455 u32 ioff
= btrfs_item_offset(right
->items
+ i
);
1456 btrfs_set_item_offset(right
->items
+ i
, ioff
+ rt_data_off
);
1459 btrfs_set_header_nritems(&l
->header
, mid
);
1461 wret
= insert_ptr(trans
, root
, path
, &right
->items
[0].key
,
1462 bh_blocknr(right_buffer
), path
->slots
[1] + 1, 1);
1465 btrfs_mark_buffer_dirty(right_buffer
);
1466 btrfs_mark_buffer_dirty(l_buf
);
1467 BUG_ON(path
->slots
[0] != slot
);
1469 btrfs_block_release(root
, path
->nodes
[0]);
1470 path
->nodes
[0] = right_buffer
;
1471 path
->slots
[0] -= mid
;
1472 path
->slots
[1] += 1;
1474 btrfs_block_release(root
, right_buffer
);
1475 BUG_ON(path
->slots
[0] < 0);
1476 check_node(root
, path
, 1);
1480 right_buffer
= btrfs_alloc_free_block(trans
, root
, l_buf
->b_blocknr
);
1481 if (IS_ERR(right_buffer
))
1482 return PTR_ERR(right_buffer
);
1484 right
= btrfs_buffer_leaf(right_buffer
);
1485 memset(&right
->header
, 0, sizeof(right
->header
));
1486 btrfs_set_header_blocknr(&right
->header
, bh_blocknr(right_buffer
));
1487 btrfs_set_header_generation(&right
->header
, trans
->transid
);
1488 btrfs_set_header_owner(&right
->header
, root
->root_key
.objectid
);
1489 btrfs_set_header_level(&right
->header
, 0);
1490 memcpy(right
->header
.fsid
, root
->fs_info
->disk_super
->fsid
,
1491 sizeof(right
->header
.fsid
));
1492 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
1493 btrfs_set_header_nritems(&right
->header
, 0);
1494 wret
= insert_ptr(trans
, root
, path
,
1496 bh_blocknr(right_buffer
),
1500 if (path
->slots
[1] == 0) {
1501 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1505 btrfs_block_release(root
, path
->nodes
[0]);
1506 path
->nodes
[0] = right_buffer
;
1508 check_node(root
, path
, 1);
1509 check_leaf(root
, path
, 0);
1513 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
1514 struct btrfs_root
*root
,
1515 struct btrfs_path
*path
,
1521 struct btrfs_leaf
*leaf
;
1522 struct buffer_head
*leaf_buf
;
1524 unsigned int data_end
;
1525 unsigned int old_data_start
;
1526 unsigned int old_size
;
1527 unsigned int size_diff
;
1530 slot_orig
= path
->slots
[0];
1531 leaf_buf
= path
->nodes
[0];
1532 leaf
= btrfs_buffer_leaf(leaf_buf
);
1534 nritems
= btrfs_header_nritems(&leaf
->header
);
1535 data_end
= leaf_data_end(root
, leaf
);
1537 slot
= path
->slots
[0];
1538 old_data_start
= btrfs_item_offset(leaf
->items
+ slot
);
1539 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1540 BUG_ON(old_size
<= new_size
);
1541 size_diff
= old_size
- new_size
;
1544 BUG_ON(slot
>= nritems
);
1547 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1549 /* first correct the data pointers */
1550 for (i
= slot
; i
< nritems
; i
++) {
1551 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1552 btrfs_set_item_offset(leaf
->items
+ i
,
1555 /* shift the data */
1556 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1557 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
1558 data_end
, old_data_start
+ new_size
- data_end
);
1559 btrfs_set_item_size(leaf
->items
+ slot
, new_size
);
1560 btrfs_mark_buffer_dirty(leaf_buf
);
1563 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1565 check_leaf(root
, path
, 0);
1569 int btrfs_extend_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1570 *root
, struct btrfs_path
*path
, u32 data_size
)
1575 struct btrfs_leaf
*leaf
;
1576 struct buffer_head
*leaf_buf
;
1578 unsigned int data_end
;
1579 unsigned int old_data
;
1580 unsigned int old_size
;
1583 slot_orig
= path
->slots
[0];
1584 leaf_buf
= path
->nodes
[0];
1585 leaf
= btrfs_buffer_leaf(leaf_buf
);
1587 nritems
= btrfs_header_nritems(&leaf
->header
);
1588 data_end
= leaf_data_end(root
, leaf
);
1590 if (btrfs_leaf_free_space(root
, leaf
) < data_size
)
1592 slot
= path
->slots
[0];
1593 old_data
= btrfs_item_end(leaf
->items
+ slot
);
1596 BUG_ON(slot
>= nritems
);
1599 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1601 /* first correct the data pointers */
1602 for (i
= slot
; i
< nritems
; i
++) {
1603 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1604 btrfs_set_item_offset(leaf
->items
+ i
,
1607 /* shift the data */
1608 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1609 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1610 data_end
, old_data
- data_end
);
1611 data_end
= old_data
;
1612 old_size
= btrfs_item_size(leaf
->items
+ slot
);
1613 btrfs_set_item_size(leaf
->items
+ slot
, old_size
+ data_size
);
1614 btrfs_mark_buffer_dirty(leaf_buf
);
1617 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1619 check_leaf(root
, path
, 0);
1624 * Given a key and some data, insert an item into the tree.
1625 * This does all the path init required, making room in the tree if needed.
1627 int btrfs_insert_empty_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1628 *root
, struct btrfs_path
*path
, struct btrfs_key
1629 *cpu_key
, u32 data_size
)
1634 struct btrfs_leaf
*leaf
;
1635 struct buffer_head
*leaf_buf
;
1637 unsigned int data_end
;
1638 struct btrfs_disk_key disk_key
;
1640 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
1642 /* create a root if there isn't one */
1645 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, data_size
, 1);
1652 slot_orig
= path
->slots
[0];
1653 leaf_buf
= path
->nodes
[0];
1654 leaf
= btrfs_buffer_leaf(leaf_buf
);
1656 nritems
= btrfs_header_nritems(&leaf
->header
);
1657 data_end
= leaf_data_end(root
, leaf
);
1659 if (btrfs_leaf_free_space(root
, leaf
) <
1660 sizeof(struct btrfs_item
) + data_size
) {
1663 slot
= path
->slots
[0];
1665 if (slot
!= nritems
) {
1667 unsigned int old_data
= btrfs_item_end(leaf
->items
+ slot
);
1670 * item0..itemN ... dataN.offset..dataN.size .. data0.size
1672 /* first correct the data pointers */
1673 for (i
= slot
; i
< nritems
; i
++) {
1674 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1675 btrfs_set_item_offset(leaf
->items
+ i
,
1679 /* shift the items */
1680 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
+ 1,
1682 (nritems
- slot
) * sizeof(struct btrfs_item
));
1684 /* shift the data */
1685 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1686 data_end
- data_size
, btrfs_leaf_data(leaf
) +
1687 data_end
, old_data
- data_end
);
1688 data_end
= old_data
;
1690 /* setup the item for the new data */
1691 btrfs_memcpy(root
, leaf
, &leaf
->items
[slot
].key
, &disk_key
,
1692 sizeof(struct btrfs_disk_key
));
1693 btrfs_set_item_offset(leaf
->items
+ slot
, data_end
- data_size
);
1694 btrfs_set_item_size(leaf
->items
+ slot
, data_size
);
1695 btrfs_set_header_nritems(&leaf
->header
, nritems
+ 1);
1696 btrfs_mark_buffer_dirty(leaf_buf
);
1700 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1702 if (btrfs_leaf_free_space(root
, leaf
) < 0)
1704 check_leaf(root
, path
, 0);
1710 * Given a key and some data, insert an item into the tree.
1711 * This does all the path init required, making room in the tree if needed.
1713 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
1714 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
1718 struct btrfs_path
*path
;
1721 path
= btrfs_alloc_path();
1723 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
1725 ptr
= btrfs_item_ptr(btrfs_buffer_leaf(path
->nodes
[0]),
1726 path
->slots
[0], u8
);
1727 btrfs_memcpy(root
, path
->nodes
[0]->b_data
,
1728 ptr
, data
, data_size
);
1729 btrfs_mark_buffer_dirty(path
->nodes
[0]);
1731 btrfs_free_path(path
);
1736 * delete the pointer from a given node.
1738 * If the delete empties a node, the node is removed from the tree,
1739 * continuing all the way the root if required. The root is converted into
1740 * a leaf if all the nodes are emptied.
1742 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1743 struct btrfs_path
*path
, int level
, int slot
)
1745 struct btrfs_node
*node
;
1746 struct buffer_head
*parent
= path
->nodes
[level
];
1751 node
= btrfs_buffer_node(parent
);
1752 nritems
= btrfs_header_nritems(&node
->header
);
1753 if (slot
!= nritems
-1) {
1754 btrfs_memmove(root
, node
, node
->ptrs
+ slot
,
1755 node
->ptrs
+ slot
+ 1,
1756 sizeof(struct btrfs_key_ptr
) *
1757 (nritems
- slot
- 1));
1760 btrfs_set_header_nritems(&node
->header
, nritems
);
1761 if (nritems
== 0 && parent
== root
->node
) {
1762 struct btrfs_header
*header
= btrfs_buffer_header(root
->node
);
1763 BUG_ON(btrfs_header_level(header
) != 1);
1764 /* just turn the root into a leaf and break */
1765 btrfs_set_header_level(header
, 0);
1766 } else if (slot
== 0) {
1767 wret
= fixup_low_keys(trans
, root
, path
, &node
->ptrs
[0].key
,
1772 btrfs_mark_buffer_dirty(parent
);
1777 * delete the item at the leaf level in path. If that empties
1778 * the leaf, remove it from the tree
1780 int btrfs_del_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
1781 struct btrfs_path
*path
)
1784 struct btrfs_leaf
*leaf
;
1785 struct buffer_head
*leaf_buf
;
1792 leaf_buf
= path
->nodes
[0];
1793 leaf
= btrfs_buffer_leaf(leaf_buf
);
1794 slot
= path
->slots
[0];
1795 doff
= btrfs_item_offset(leaf
->items
+ slot
);
1796 dsize
= btrfs_item_size(leaf
->items
+ slot
);
1797 nritems
= btrfs_header_nritems(&leaf
->header
);
1799 if (slot
!= nritems
- 1) {
1801 int data_end
= leaf_data_end(root
, leaf
);
1802 btrfs_memmove(root
, leaf
, btrfs_leaf_data(leaf
) +
1804 btrfs_leaf_data(leaf
) + data_end
,
1806 for (i
= slot
+ 1; i
< nritems
; i
++) {
1807 u32 ioff
= btrfs_item_offset(leaf
->items
+ i
);
1808 btrfs_set_item_offset(leaf
->items
+ i
, ioff
+ dsize
);
1810 btrfs_memmove(root
, leaf
, leaf
->items
+ slot
,
1811 leaf
->items
+ slot
+ 1,
1812 sizeof(struct btrfs_item
) *
1813 (nritems
- slot
- 1));
1815 btrfs_set_header_nritems(&leaf
->header
, nritems
- 1);
1817 /* delete the leaf if we've emptied it */
1819 if (leaf_buf
== root
->node
) {
1820 btrfs_set_header_level(&leaf
->header
, 0);
1822 clean_tree_block(trans
, root
, leaf_buf
);
1823 wait_on_buffer(leaf_buf
);
1824 wret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
1827 wret
= btrfs_free_extent(trans
, root
,
1828 bh_blocknr(leaf_buf
), 1, 1);
1833 int used
= leaf_space_used(leaf
, 0, nritems
);
1835 wret
= fixup_low_keys(trans
, root
, path
,
1836 &leaf
->items
[0].key
, 1);
1841 /* delete the leaf if it is mostly empty */
1842 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
1843 /* push_leaf_left fixes the path.
1844 * make sure the path still points to our leaf
1845 * for possible call to del_ptr below
1847 slot
= path
->slots
[1];
1849 wret
= push_leaf_left(trans
, root
, path
, 1);
1850 if (wret
< 0 && wret
!= -ENOSPC
)
1852 if (path
->nodes
[0] == leaf_buf
&&
1853 btrfs_header_nritems(&leaf
->header
)) {
1854 wret
= push_leaf_right(trans
, root
, path
, 1);
1855 if (wret
< 0 && wret
!= -ENOSPC
)
1858 if (btrfs_header_nritems(&leaf
->header
) == 0) {
1859 u64 blocknr
= bh_blocknr(leaf_buf
);
1860 clean_tree_block(trans
, root
, leaf_buf
);
1861 wait_on_buffer(leaf_buf
);
1862 wret
= del_ptr(trans
, root
, path
, 1, slot
);
1865 btrfs_block_release(root
, leaf_buf
);
1866 wret
= btrfs_free_extent(trans
, root
, blocknr
,
1871 btrfs_mark_buffer_dirty(leaf_buf
);
1872 btrfs_block_release(root
, leaf_buf
);
1875 btrfs_mark_buffer_dirty(leaf_buf
);
1882 * walk up the tree as far as required to find the next leaf.
1883 * returns 0 if it found something or 1 if there are no greater leaves.
1884 * returns < 0 on io errors.
1886 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
1891 struct buffer_head
*c
;
1892 struct btrfs_node
*c_node
;
1893 struct buffer_head
*next
= NULL
;
1895 while(level
< BTRFS_MAX_LEVEL
) {
1896 if (!path
->nodes
[level
])
1898 slot
= path
->slots
[level
] + 1;
1899 c
= path
->nodes
[level
];
1900 c_node
= btrfs_buffer_node(c
);
1901 if (slot
>= btrfs_header_nritems(&c_node
->header
)) {
1905 blocknr
= btrfs_node_blockptr(c_node
, slot
);
1907 btrfs_block_release(root
, next
);
1908 next
= read_tree_block(root
, blocknr
);
1911 path
->slots
[level
] = slot
;
1914 c
= path
->nodes
[level
];
1915 btrfs_block_release(root
, c
);
1916 path
->nodes
[level
] = next
;
1917 path
->slots
[level
] = 0;
1920 next
= read_tree_block(root
,
1921 btrfs_node_blockptr(btrfs_buffer_node(next
), 0));
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