2 * Copyright (C) 2007,2008 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>
20 #include <linux/slab.h>
23 #include "transaction.h"
24 #include "print-tree.h"
27 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
28 *root
, struct btrfs_path
*path
, int level
);
29 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
30 *root
, struct btrfs_key
*ins_key
,
31 struct btrfs_path
*path
, int data_size
, int extend
);
32 static int push_node_left(struct btrfs_trans_handle
*trans
,
33 struct btrfs_root
*root
, struct extent_buffer
*dst
,
34 struct extent_buffer
*src
, int empty
);
35 static int balance_node_right(struct btrfs_trans_handle
*trans
,
36 struct btrfs_root
*root
,
37 struct extent_buffer
*dst_buf
,
38 struct extent_buffer
*src_buf
);
39 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
40 struct btrfs_path
*path
, int level
, int slot
);
41 static int setup_items_for_insert(struct btrfs_trans_handle
*trans
,
42 struct btrfs_root
*root
, struct btrfs_path
*path
,
43 struct btrfs_key
*cpu_key
, u32
*data_size
,
44 u32 total_data
, u32 total_size
, int nr
);
47 struct btrfs_path
*btrfs_alloc_path(void)
49 struct btrfs_path
*path
;
50 path
= kmem_cache_zalloc(btrfs_path_cachep
, GFP_NOFS
);
57 * set all locked nodes in the path to blocking locks. This should
58 * be done before scheduling
60 noinline
void btrfs_set_path_blocking(struct btrfs_path
*p
)
63 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
64 if (p
->nodes
[i
] && p
->locks
[i
])
65 btrfs_set_lock_blocking(p
->nodes
[i
]);
70 * reset all the locked nodes in the patch to spinning locks.
72 * held is used to keep lockdep happy, when lockdep is enabled
73 * we set held to a blocking lock before we go around and
74 * retake all the spinlocks in the path. You can safely use NULL
77 noinline
void btrfs_clear_path_blocking(struct btrfs_path
*p
,
78 struct extent_buffer
*held
)
82 #ifdef CONFIG_DEBUG_LOCK_ALLOC
83 /* lockdep really cares that we take all of these spinlocks
84 * in the right order. If any of the locks in the path are not
85 * currently blocking, it is going to complain. So, make really
86 * really sure by forcing the path to blocking before we clear
90 btrfs_set_lock_blocking(held
);
91 btrfs_set_path_blocking(p
);
94 for (i
= BTRFS_MAX_LEVEL
- 1; i
>= 0; i
--) {
95 if (p
->nodes
[i
] && p
->locks
[i
])
96 btrfs_clear_lock_blocking(p
->nodes
[i
]);
99 #ifdef CONFIG_DEBUG_LOCK_ALLOC
101 btrfs_clear_lock_blocking(held
);
105 /* this also releases the path */
106 void btrfs_free_path(struct btrfs_path
*p
)
110 btrfs_release_path(NULL
, p
);
111 kmem_cache_free(btrfs_path_cachep
, p
);
115 * path release drops references on the extent buffers in the path
116 * and it drops any locks held by this path
118 * It is safe to call this on paths that no locks or extent buffers held.
120 noinline
void btrfs_release_path(struct btrfs_root
*root
, struct btrfs_path
*p
)
124 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
129 btrfs_tree_unlock(p
->nodes
[i
]);
132 free_extent_buffer(p
->nodes
[i
]);
138 * safely gets a reference on the root node of a tree. A lock
139 * is not taken, so a concurrent writer may put a different node
140 * at the root of the tree. See btrfs_lock_root_node for the
143 * The extent buffer returned by this has a reference taken, so
144 * it won't disappear. It may stop being the root of the tree
145 * at any time because there are no locks held.
147 struct extent_buffer
*btrfs_root_node(struct btrfs_root
*root
)
149 struct extent_buffer
*eb
;
152 eb
= rcu_dereference(root
->node
);
153 extent_buffer_get(eb
);
158 /* loop around taking references on and locking the root node of the
159 * tree until you end up with a lock on the root. A locked buffer
160 * is returned, with a reference held.
162 struct extent_buffer
*btrfs_lock_root_node(struct btrfs_root
*root
)
164 struct extent_buffer
*eb
;
167 eb
= btrfs_root_node(root
);
169 if (eb
== root
->node
)
171 btrfs_tree_unlock(eb
);
172 free_extent_buffer(eb
);
177 /* cowonly root (everything not a reference counted cow subvolume), just get
178 * put onto a simple dirty list. transaction.c walks this to make sure they
179 * get properly updated on disk.
181 static void add_root_to_dirty_list(struct btrfs_root
*root
)
183 if (root
->track_dirty
&& list_empty(&root
->dirty_list
)) {
184 list_add(&root
->dirty_list
,
185 &root
->fs_info
->dirty_cowonly_roots
);
190 * used by snapshot creation to make a copy of a root for a tree with
191 * a given objectid. The buffer with the new root node is returned in
192 * cow_ret, and this func returns zero on success or a negative error code.
194 int btrfs_copy_root(struct btrfs_trans_handle
*trans
,
195 struct btrfs_root
*root
,
196 struct extent_buffer
*buf
,
197 struct extent_buffer
**cow_ret
, u64 new_root_objectid
)
199 struct extent_buffer
*cow
;
202 struct btrfs_disk_key disk_key
;
204 WARN_ON(root
->ref_cows
&& trans
->transid
!=
205 root
->fs_info
->running_transaction
->transid
);
206 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
208 level
= btrfs_header_level(buf
);
210 btrfs_item_key(buf
, &disk_key
, 0);
212 btrfs_node_key(buf
, &disk_key
, 0);
214 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, 0,
215 new_root_objectid
, &disk_key
, level
,
220 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
221 btrfs_set_header_bytenr(cow
, cow
->start
);
222 btrfs_set_header_generation(cow
, trans
->transid
);
223 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
224 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
225 BTRFS_HEADER_FLAG_RELOC
);
226 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
227 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
229 btrfs_set_header_owner(cow
, new_root_objectid
);
231 write_extent_buffer(cow
, root
->fs_info
->fsid
,
232 (unsigned long)btrfs_header_fsid(cow
),
235 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
236 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
237 ret
= btrfs_inc_ref(trans
, root
, cow
, 1);
239 ret
= btrfs_inc_ref(trans
, root
, cow
, 0);
244 btrfs_mark_buffer_dirty(cow
);
250 * check if the tree block can be shared by multiple trees
252 int btrfs_block_can_be_shared(struct btrfs_root
*root
,
253 struct extent_buffer
*buf
)
256 * Tree blocks not in refernece counted trees and tree roots
257 * are never shared. If a block was allocated after the last
258 * snapshot and the block was not allocated by tree relocation,
259 * we know the block is not shared.
261 if (root
->ref_cows
&&
262 buf
!= root
->node
&& buf
!= root
->commit_root
&&
263 (btrfs_header_generation(buf
) <=
264 btrfs_root_last_snapshot(&root
->root_item
) ||
265 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)))
267 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
268 if (root
->ref_cows
&&
269 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
275 static noinline
int update_ref_for_cow(struct btrfs_trans_handle
*trans
,
276 struct btrfs_root
*root
,
277 struct extent_buffer
*buf
,
278 struct extent_buffer
*cow
,
288 * Backrefs update rules:
290 * Always use full backrefs for extent pointers in tree block
291 * allocated by tree relocation.
293 * If a shared tree block is no longer referenced by its owner
294 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
295 * use full backrefs for extent pointers in tree block.
297 * If a tree block is been relocating
298 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
299 * use full backrefs for extent pointers in tree block.
300 * The reason for this is some operations (such as drop tree)
301 * are only allowed for blocks use full backrefs.
304 if (btrfs_block_can_be_shared(root
, buf
)) {
305 ret
= btrfs_lookup_extent_info(trans
, root
, buf
->start
,
306 buf
->len
, &refs
, &flags
);
311 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
312 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
313 flags
= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
318 owner
= btrfs_header_owner(buf
);
319 BUG_ON(owner
== BTRFS_TREE_RELOC_OBJECTID
&&
320 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
));
323 if ((owner
== root
->root_key
.objectid
||
324 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) &&
325 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)) {
326 ret
= btrfs_inc_ref(trans
, root
, buf
, 1);
329 if (root
->root_key
.objectid
==
330 BTRFS_TREE_RELOC_OBJECTID
) {
331 ret
= btrfs_dec_ref(trans
, root
, buf
, 0);
333 ret
= btrfs_inc_ref(trans
, root
, cow
, 1);
336 new_flags
|= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
339 if (root
->root_key
.objectid
==
340 BTRFS_TREE_RELOC_OBJECTID
)
341 ret
= btrfs_inc_ref(trans
, root
, cow
, 1);
343 ret
= btrfs_inc_ref(trans
, root
, cow
, 0);
346 if (new_flags
!= 0) {
347 ret
= btrfs_set_disk_extent_flags(trans
, root
,
354 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
) {
355 if (root
->root_key
.objectid
==
356 BTRFS_TREE_RELOC_OBJECTID
)
357 ret
= btrfs_inc_ref(trans
, root
, cow
, 1);
359 ret
= btrfs_inc_ref(trans
, root
, cow
, 0);
361 ret
= btrfs_dec_ref(trans
, root
, buf
, 1);
364 clean_tree_block(trans
, root
, buf
);
371 * does the dirty work in cow of a single block. The parent block (if
372 * supplied) is updated to point to the new cow copy. The new buffer is marked
373 * dirty and returned locked. If you modify the block it needs to be marked
376 * search_start -- an allocation hint for the new block
378 * empty_size -- a hint that you plan on doing more cow. This is the size in
379 * bytes the allocator should try to find free next to the block it returns.
380 * This is just a hint and may be ignored by the allocator.
382 static noinline
int __btrfs_cow_block(struct btrfs_trans_handle
*trans
,
383 struct btrfs_root
*root
,
384 struct extent_buffer
*buf
,
385 struct extent_buffer
*parent
, int parent_slot
,
386 struct extent_buffer
**cow_ret
,
387 u64 search_start
, u64 empty_size
)
389 struct btrfs_disk_key disk_key
;
390 struct extent_buffer
*cow
;
399 btrfs_assert_tree_locked(buf
);
401 WARN_ON(root
->ref_cows
&& trans
->transid
!=
402 root
->fs_info
->running_transaction
->transid
);
403 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
405 level
= btrfs_header_level(buf
);
408 btrfs_item_key(buf
, &disk_key
, 0);
410 btrfs_node_key(buf
, &disk_key
, 0);
412 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
414 parent_start
= parent
->start
;
420 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, parent_start
,
421 root
->root_key
.objectid
, &disk_key
,
422 level
, search_start
, empty_size
);
426 /* cow is set to blocking by btrfs_init_new_buffer */
428 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
429 btrfs_set_header_bytenr(cow
, cow
->start
);
430 btrfs_set_header_generation(cow
, trans
->transid
);
431 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
432 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
433 BTRFS_HEADER_FLAG_RELOC
);
434 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
435 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
437 btrfs_set_header_owner(cow
, root
->root_key
.objectid
);
439 write_extent_buffer(cow
, root
->fs_info
->fsid
,
440 (unsigned long)btrfs_header_fsid(cow
),
443 update_ref_for_cow(trans
, root
, buf
, cow
, &last_ref
);
446 btrfs_reloc_cow_block(trans
, root
, buf
, cow
);
448 if (buf
== root
->node
) {
449 WARN_ON(parent
&& parent
!= buf
);
450 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
451 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
452 parent_start
= buf
->start
;
456 extent_buffer_get(cow
);
457 rcu_assign_pointer(root
->node
, cow
);
459 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
461 free_extent_buffer(buf
);
462 add_root_to_dirty_list(root
);
464 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
465 parent_start
= parent
->start
;
469 WARN_ON(trans
->transid
!= btrfs_header_generation(parent
));
470 btrfs_set_node_blockptr(parent
, parent_slot
,
472 btrfs_set_node_ptr_generation(parent
, parent_slot
,
474 btrfs_mark_buffer_dirty(parent
);
475 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
479 btrfs_tree_unlock(buf
);
480 free_extent_buffer(buf
);
481 btrfs_mark_buffer_dirty(cow
);
486 static inline int should_cow_block(struct btrfs_trans_handle
*trans
,
487 struct btrfs_root
*root
,
488 struct extent_buffer
*buf
)
490 if (btrfs_header_generation(buf
) == trans
->transid
&&
491 !btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_WRITTEN
) &&
492 !(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
&&
493 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)))
499 * cows a single block, see __btrfs_cow_block for the real work.
500 * This version of it has extra checks so that a block isn't cow'd more than
501 * once per transaction, as long as it hasn't been written yet
503 noinline
int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
504 struct btrfs_root
*root
, struct extent_buffer
*buf
,
505 struct extent_buffer
*parent
, int parent_slot
,
506 struct extent_buffer
**cow_ret
)
511 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
512 printk(KERN_CRIT
"trans %llu running %llu\n",
513 (unsigned long long)trans
->transid
,
515 root
->fs_info
->running_transaction
->transid
);
518 if (trans
->transid
!= root
->fs_info
->generation
) {
519 printk(KERN_CRIT
"trans %llu running %llu\n",
520 (unsigned long long)trans
->transid
,
521 (unsigned long long)root
->fs_info
->generation
);
525 if (!should_cow_block(trans
, root
, buf
)) {
530 search_start
= buf
->start
& ~((u64
)(1024 * 1024 * 1024) - 1);
533 btrfs_set_lock_blocking(parent
);
534 btrfs_set_lock_blocking(buf
);
536 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
537 parent_slot
, cow_ret
, search_start
, 0);
539 trace_btrfs_cow_block(root
, buf
, *cow_ret
);
545 * helper function for defrag to decide if two blocks pointed to by a
546 * node are actually close by
548 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
550 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
552 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
558 * compare two keys in a memcmp fashion
560 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
564 btrfs_disk_key_to_cpu(&k1
, disk
);
566 return btrfs_comp_cpu_keys(&k1
, k2
);
570 * same as comp_keys only with two btrfs_key's
572 int btrfs_comp_cpu_keys(struct btrfs_key
*k1
, struct btrfs_key
*k2
)
574 if (k1
->objectid
> k2
->objectid
)
576 if (k1
->objectid
< k2
->objectid
)
578 if (k1
->type
> k2
->type
)
580 if (k1
->type
< k2
->type
)
582 if (k1
->offset
> k2
->offset
)
584 if (k1
->offset
< k2
->offset
)
590 * this is used by the defrag code to go through all the
591 * leaves pointed to by a node and reallocate them so that
592 * disk order is close to key order
594 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
595 struct btrfs_root
*root
, struct extent_buffer
*parent
,
596 int start_slot
, int cache_only
, u64
*last_ret
,
597 struct btrfs_key
*progress
)
599 struct extent_buffer
*cur
;
602 u64 search_start
= *last_ret
;
612 int progress_passed
= 0;
613 struct btrfs_disk_key disk_key
;
615 parent_level
= btrfs_header_level(parent
);
616 if (cache_only
&& parent_level
!= 1)
619 if (trans
->transaction
!= root
->fs_info
->running_transaction
)
621 if (trans
->transid
!= root
->fs_info
->generation
)
624 parent_nritems
= btrfs_header_nritems(parent
);
625 blocksize
= btrfs_level_size(root
, parent_level
- 1);
626 end_slot
= parent_nritems
;
628 if (parent_nritems
== 1)
631 btrfs_set_lock_blocking(parent
);
633 for (i
= start_slot
; i
< end_slot
; i
++) {
636 if (!parent
->map_token
) {
637 map_extent_buffer(parent
,
638 btrfs_node_key_ptr_offset(i
),
639 sizeof(struct btrfs_key_ptr
),
640 &parent
->map_token
, &parent
->kaddr
,
641 &parent
->map_start
, &parent
->map_len
,
644 btrfs_node_key(parent
, &disk_key
, i
);
645 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
649 blocknr
= btrfs_node_blockptr(parent
, i
);
650 gen
= btrfs_node_ptr_generation(parent
, i
);
652 last_block
= blocknr
;
655 other
= btrfs_node_blockptr(parent
, i
- 1);
656 close
= close_blocks(blocknr
, other
, blocksize
);
658 if (!close
&& i
< end_slot
- 2) {
659 other
= btrfs_node_blockptr(parent
, i
+ 1);
660 close
= close_blocks(blocknr
, other
, blocksize
);
663 last_block
= blocknr
;
666 if (parent
->map_token
) {
667 unmap_extent_buffer(parent
, parent
->map_token
,
669 parent
->map_token
= NULL
;
672 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
674 uptodate
= btrfs_buffer_uptodate(cur
, gen
);
677 if (!cur
|| !uptodate
) {
679 free_extent_buffer(cur
);
683 cur
= read_tree_block(root
, blocknr
,
685 } else if (!uptodate
) {
686 btrfs_read_buffer(cur
, gen
);
689 if (search_start
== 0)
690 search_start
= last_block
;
692 btrfs_tree_lock(cur
);
693 btrfs_set_lock_blocking(cur
);
694 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
697 (end_slot
- i
) * blocksize
));
699 btrfs_tree_unlock(cur
);
700 free_extent_buffer(cur
);
703 search_start
= cur
->start
;
704 last_block
= cur
->start
;
705 *last_ret
= search_start
;
706 btrfs_tree_unlock(cur
);
707 free_extent_buffer(cur
);
709 if (parent
->map_token
) {
710 unmap_extent_buffer(parent
, parent
->map_token
,
712 parent
->map_token
= NULL
;
718 * The leaf data grows from end-to-front in the node.
719 * this returns the address of the start of the last item,
720 * which is the stop of the leaf data stack
722 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
723 struct extent_buffer
*leaf
)
725 u32 nr
= btrfs_header_nritems(leaf
);
727 return BTRFS_LEAF_DATA_SIZE(root
);
728 return btrfs_item_offset_nr(leaf
, nr
- 1);
733 * search for key in the extent_buffer. The items start at offset p,
734 * and they are item_size apart. There are 'max' items in p.
736 * the slot in the array is returned via slot, and it points to
737 * the place where you would insert key if it is not found in
740 * slot may point to max if the key is bigger than all of the keys
742 static noinline
int generic_bin_search(struct extent_buffer
*eb
,
744 int item_size
, struct btrfs_key
*key
,
751 struct btrfs_disk_key
*tmp
= NULL
;
752 struct btrfs_disk_key unaligned
;
753 unsigned long offset
;
754 char *map_token
= NULL
;
756 unsigned long map_start
= 0;
757 unsigned long map_len
= 0;
761 mid
= (low
+ high
) / 2;
762 offset
= p
+ mid
* item_size
;
764 if (!map_token
|| offset
< map_start
||
765 (offset
+ sizeof(struct btrfs_disk_key
)) >
766 map_start
+ map_len
) {
768 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
772 err
= map_private_extent_buffer(eb
, offset
,
773 sizeof(struct btrfs_disk_key
),
775 &map_start
, &map_len
, KM_USER0
);
778 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
781 read_extent_buffer(eb
, &unaligned
,
782 offset
, sizeof(unaligned
));
787 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
790 ret
= comp_keys(tmp
, key
);
799 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
805 unmap_extent_buffer(eb
, map_token
, KM_USER0
);
810 * simple bin_search frontend that does the right thing for
813 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
814 int level
, int *slot
)
817 return generic_bin_search(eb
,
818 offsetof(struct btrfs_leaf
, items
),
819 sizeof(struct btrfs_item
),
820 key
, btrfs_header_nritems(eb
),
823 return generic_bin_search(eb
,
824 offsetof(struct btrfs_node
, ptrs
),
825 sizeof(struct btrfs_key_ptr
),
826 key
, btrfs_header_nritems(eb
),
832 int btrfs_bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
833 int level
, int *slot
)
835 return bin_search(eb
, key
, level
, slot
);
838 static void root_add_used(struct btrfs_root
*root
, u32 size
)
840 spin_lock(&root
->accounting_lock
);
841 btrfs_set_root_used(&root
->root_item
,
842 btrfs_root_used(&root
->root_item
) + size
);
843 spin_unlock(&root
->accounting_lock
);
846 static void root_sub_used(struct btrfs_root
*root
, u32 size
)
848 spin_lock(&root
->accounting_lock
);
849 btrfs_set_root_used(&root
->root_item
,
850 btrfs_root_used(&root
->root_item
) - size
);
851 spin_unlock(&root
->accounting_lock
);
854 /* given a node and slot number, this reads the blocks it points to. The
855 * extent buffer is returned with a reference taken (but unlocked).
856 * NULL is returned on error.
858 static noinline
struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
859 struct extent_buffer
*parent
, int slot
)
861 int level
= btrfs_header_level(parent
);
864 if (slot
>= btrfs_header_nritems(parent
))
869 return read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
870 btrfs_level_size(root
, level
- 1),
871 btrfs_node_ptr_generation(parent
, slot
));
875 * node level balancing, used to make sure nodes are in proper order for
876 * item deletion. We balance from the top down, so we have to make sure
877 * that a deletion won't leave an node completely empty later on.
879 static noinline
int balance_level(struct btrfs_trans_handle
*trans
,
880 struct btrfs_root
*root
,
881 struct btrfs_path
*path
, int level
)
883 struct extent_buffer
*right
= NULL
;
884 struct extent_buffer
*mid
;
885 struct extent_buffer
*left
= NULL
;
886 struct extent_buffer
*parent
= NULL
;
890 int orig_slot
= path
->slots
[level
];
896 mid
= path
->nodes
[level
];
898 WARN_ON(!path
->locks
[level
]);
899 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
901 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
903 if (level
< BTRFS_MAX_LEVEL
- 1)
904 parent
= path
->nodes
[level
+ 1];
905 pslot
= path
->slots
[level
+ 1];
908 * deal with the case where there is only one pointer in the root
909 * by promoting the node below to a root
912 struct extent_buffer
*child
;
914 if (btrfs_header_nritems(mid
) != 1)
917 /* promote the child to a root */
918 child
= read_node_slot(root
, mid
, 0);
920 btrfs_tree_lock(child
);
921 btrfs_set_lock_blocking(child
);
922 ret
= btrfs_cow_block(trans
, root
, child
, mid
, 0, &child
);
924 btrfs_tree_unlock(child
);
925 free_extent_buffer(child
);
929 rcu_assign_pointer(root
->node
, child
);
931 add_root_to_dirty_list(root
);
932 btrfs_tree_unlock(child
);
934 path
->locks
[level
] = 0;
935 path
->nodes
[level
] = NULL
;
936 clean_tree_block(trans
, root
, mid
);
937 btrfs_tree_unlock(mid
);
938 /* once for the path */
939 free_extent_buffer(mid
);
941 root_sub_used(root
, mid
->len
);
942 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
943 /* once for the root ptr */
944 free_extent_buffer(mid
);
947 if (btrfs_header_nritems(mid
) >
948 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
951 btrfs_header_nritems(mid
);
953 left
= read_node_slot(root
, parent
, pslot
- 1);
955 btrfs_tree_lock(left
);
956 btrfs_set_lock_blocking(left
);
957 wret
= btrfs_cow_block(trans
, root
, left
,
958 parent
, pslot
- 1, &left
);
964 right
= read_node_slot(root
, parent
, pslot
+ 1);
966 btrfs_tree_lock(right
);
967 btrfs_set_lock_blocking(right
);
968 wret
= btrfs_cow_block(trans
, root
, right
,
969 parent
, pslot
+ 1, &right
);
976 /* first, try to make some room in the middle buffer */
978 orig_slot
+= btrfs_header_nritems(left
);
979 wret
= push_node_left(trans
, root
, left
, mid
, 1);
982 btrfs_header_nritems(mid
);
986 * then try to empty the right most buffer into the middle
989 wret
= push_node_left(trans
, root
, mid
, right
, 1);
990 if (wret
< 0 && wret
!= -ENOSPC
)
992 if (btrfs_header_nritems(right
) == 0) {
993 clean_tree_block(trans
, root
, right
);
994 btrfs_tree_unlock(right
);
995 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
999 root_sub_used(root
, right
->len
);
1000 btrfs_free_tree_block(trans
, root
, right
, 0, 1);
1001 free_extent_buffer(right
);
1004 struct btrfs_disk_key right_key
;
1005 btrfs_node_key(right
, &right_key
, 0);
1006 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
1007 btrfs_mark_buffer_dirty(parent
);
1010 if (btrfs_header_nritems(mid
) == 1) {
1012 * we're not allowed to leave a node with one item in the
1013 * tree during a delete. A deletion from lower in the tree
1014 * could try to delete the only pointer in this node.
1015 * So, pull some keys from the left.
1016 * There has to be a left pointer at this point because
1017 * otherwise we would have pulled some pointers from the
1021 wret
= balance_node_right(trans
, root
, mid
, left
);
1027 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1033 if (btrfs_header_nritems(mid
) == 0) {
1034 clean_tree_block(trans
, root
, mid
);
1035 btrfs_tree_unlock(mid
);
1036 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
1039 root_sub_used(root
, mid
->len
);
1040 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
1041 free_extent_buffer(mid
);
1044 /* update the parent key to reflect our changes */
1045 struct btrfs_disk_key mid_key
;
1046 btrfs_node_key(mid
, &mid_key
, 0);
1047 btrfs_set_node_key(parent
, &mid_key
, pslot
);
1048 btrfs_mark_buffer_dirty(parent
);
1051 /* update the path */
1053 if (btrfs_header_nritems(left
) > orig_slot
) {
1054 extent_buffer_get(left
);
1055 /* left was locked after cow */
1056 path
->nodes
[level
] = left
;
1057 path
->slots
[level
+ 1] -= 1;
1058 path
->slots
[level
] = orig_slot
;
1060 btrfs_tree_unlock(mid
);
1061 free_extent_buffer(mid
);
1064 orig_slot
-= btrfs_header_nritems(left
);
1065 path
->slots
[level
] = orig_slot
;
1068 /* double check we haven't messed things up */
1070 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
1074 btrfs_tree_unlock(right
);
1075 free_extent_buffer(right
);
1078 if (path
->nodes
[level
] != left
)
1079 btrfs_tree_unlock(left
);
1080 free_extent_buffer(left
);
1085 /* Node balancing for insertion. Here we only split or push nodes around
1086 * when they are completely full. This is also done top down, so we
1087 * have to be pessimistic.
1089 static noinline
int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
1090 struct btrfs_root
*root
,
1091 struct btrfs_path
*path
, int level
)
1093 struct extent_buffer
*right
= NULL
;
1094 struct extent_buffer
*mid
;
1095 struct extent_buffer
*left
= NULL
;
1096 struct extent_buffer
*parent
= NULL
;
1100 int orig_slot
= path
->slots
[level
];
1105 mid
= path
->nodes
[level
];
1106 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1108 if (level
< BTRFS_MAX_LEVEL
- 1)
1109 parent
= path
->nodes
[level
+ 1];
1110 pslot
= path
->slots
[level
+ 1];
1115 left
= read_node_slot(root
, parent
, pslot
- 1);
1117 /* first, try to make some room in the middle buffer */
1121 btrfs_tree_lock(left
);
1122 btrfs_set_lock_blocking(left
);
1124 left_nr
= btrfs_header_nritems(left
);
1125 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1128 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
1133 wret
= push_node_left(trans
, root
,
1140 struct btrfs_disk_key disk_key
;
1141 orig_slot
+= left_nr
;
1142 btrfs_node_key(mid
, &disk_key
, 0);
1143 btrfs_set_node_key(parent
, &disk_key
, pslot
);
1144 btrfs_mark_buffer_dirty(parent
);
1145 if (btrfs_header_nritems(left
) > orig_slot
) {
1146 path
->nodes
[level
] = left
;
1147 path
->slots
[level
+ 1] -= 1;
1148 path
->slots
[level
] = orig_slot
;
1149 btrfs_tree_unlock(mid
);
1150 free_extent_buffer(mid
);
1153 btrfs_header_nritems(left
);
1154 path
->slots
[level
] = orig_slot
;
1155 btrfs_tree_unlock(left
);
1156 free_extent_buffer(left
);
1160 btrfs_tree_unlock(left
);
1161 free_extent_buffer(left
);
1163 right
= read_node_slot(root
, parent
, pslot
+ 1);
1166 * then try to empty the right most buffer into the middle
1171 btrfs_tree_lock(right
);
1172 btrfs_set_lock_blocking(right
);
1174 right_nr
= btrfs_header_nritems(right
);
1175 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1178 ret
= btrfs_cow_block(trans
, root
, right
,
1184 wret
= balance_node_right(trans
, root
,
1191 struct btrfs_disk_key disk_key
;
1193 btrfs_node_key(right
, &disk_key
, 0);
1194 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
1195 btrfs_mark_buffer_dirty(parent
);
1197 if (btrfs_header_nritems(mid
) <= orig_slot
) {
1198 path
->nodes
[level
] = right
;
1199 path
->slots
[level
+ 1] += 1;
1200 path
->slots
[level
] = orig_slot
-
1201 btrfs_header_nritems(mid
);
1202 btrfs_tree_unlock(mid
);
1203 free_extent_buffer(mid
);
1205 btrfs_tree_unlock(right
);
1206 free_extent_buffer(right
);
1210 btrfs_tree_unlock(right
);
1211 free_extent_buffer(right
);
1217 * readahead one full node of leaves, finding things that are close
1218 * to the block in 'slot', and triggering ra on them.
1220 static void reada_for_search(struct btrfs_root
*root
,
1221 struct btrfs_path
*path
,
1222 int level
, int slot
, u64 objectid
)
1224 struct extent_buffer
*node
;
1225 struct btrfs_disk_key disk_key
;
1230 int direction
= path
->reada
;
1231 struct extent_buffer
*eb
;
1239 if (!path
->nodes
[level
])
1242 node
= path
->nodes
[level
];
1244 search
= btrfs_node_blockptr(node
, slot
);
1245 blocksize
= btrfs_level_size(root
, level
- 1);
1246 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
1248 free_extent_buffer(eb
);
1254 nritems
= btrfs_header_nritems(node
);
1257 if (direction
< 0) {
1261 } else if (direction
> 0) {
1266 if (path
->reada
< 0 && objectid
) {
1267 btrfs_node_key(node
, &disk_key
, nr
);
1268 if (btrfs_disk_key_objectid(&disk_key
) != objectid
)
1271 search
= btrfs_node_blockptr(node
, nr
);
1272 if ((search
<= target
&& target
- search
<= 65536) ||
1273 (search
> target
&& search
- target
<= 65536)) {
1274 readahead_tree_block(root
, search
, blocksize
,
1275 btrfs_node_ptr_generation(node
, nr
));
1279 if ((nread
> 65536 || nscan
> 32))
1285 * returns -EAGAIN if it had to drop the path, or zero if everything was in
1288 static noinline
int reada_for_balance(struct btrfs_root
*root
,
1289 struct btrfs_path
*path
, int level
)
1293 struct extent_buffer
*parent
;
1294 struct extent_buffer
*eb
;
1301 parent
= path
->nodes
[level
+ 1];
1305 nritems
= btrfs_header_nritems(parent
);
1306 slot
= path
->slots
[level
+ 1];
1307 blocksize
= btrfs_level_size(root
, level
);
1310 block1
= btrfs_node_blockptr(parent
, slot
- 1);
1311 gen
= btrfs_node_ptr_generation(parent
, slot
- 1);
1312 eb
= btrfs_find_tree_block(root
, block1
, blocksize
);
1313 if (eb
&& btrfs_buffer_uptodate(eb
, gen
))
1315 free_extent_buffer(eb
);
1317 if (slot
+ 1 < nritems
) {
1318 block2
= btrfs_node_blockptr(parent
, slot
+ 1);
1319 gen
= btrfs_node_ptr_generation(parent
, slot
+ 1);
1320 eb
= btrfs_find_tree_block(root
, block2
, blocksize
);
1321 if (eb
&& btrfs_buffer_uptodate(eb
, gen
))
1323 free_extent_buffer(eb
);
1325 if (block1
|| block2
) {
1328 /* release the whole path */
1329 btrfs_release_path(root
, path
);
1331 /* read the blocks */
1333 readahead_tree_block(root
, block1
, blocksize
, 0);
1335 readahead_tree_block(root
, block2
, blocksize
, 0);
1338 eb
= read_tree_block(root
, block1
, blocksize
, 0);
1339 free_extent_buffer(eb
);
1342 eb
= read_tree_block(root
, block2
, blocksize
, 0);
1343 free_extent_buffer(eb
);
1351 * when we walk down the tree, it is usually safe to unlock the higher layers
1352 * in the tree. The exceptions are when our path goes through slot 0, because
1353 * operations on the tree might require changing key pointers higher up in the
1356 * callers might also have set path->keep_locks, which tells this code to keep
1357 * the lock if the path points to the last slot in the block. This is part of
1358 * walking through the tree, and selecting the next slot in the higher block.
1360 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
1361 * if lowest_unlock is 1, level 0 won't be unlocked
1363 static noinline
void unlock_up(struct btrfs_path
*path
, int level
,
1367 int skip_level
= level
;
1369 struct extent_buffer
*t
;
1371 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1372 if (!path
->nodes
[i
])
1374 if (!path
->locks
[i
])
1376 if (!no_skips
&& path
->slots
[i
] == 0) {
1380 if (!no_skips
&& path
->keep_locks
) {
1383 nritems
= btrfs_header_nritems(t
);
1384 if (nritems
< 1 || path
->slots
[i
] >= nritems
- 1) {
1389 if (skip_level
< i
&& i
>= lowest_unlock
)
1393 if (i
>= lowest_unlock
&& i
> skip_level
&& path
->locks
[i
]) {
1394 btrfs_tree_unlock(t
);
1401 * This releases any locks held in the path starting at level and
1402 * going all the way up to the root.
1404 * btrfs_search_slot will keep the lock held on higher nodes in a few
1405 * corner cases, such as COW of the block at slot zero in the node. This
1406 * ignores those rules, and it should only be called when there are no
1407 * more updates to be done higher up in the tree.
1409 noinline
void btrfs_unlock_up_safe(struct btrfs_path
*path
, int level
)
1413 if (path
->keep_locks
)
1416 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1417 if (!path
->nodes
[i
])
1419 if (!path
->locks
[i
])
1421 btrfs_tree_unlock(path
->nodes
[i
]);
1427 * helper function for btrfs_search_slot. The goal is to find a block
1428 * in cache without setting the path to blocking. If we find the block
1429 * we return zero and the path is unchanged.
1431 * If we can't find the block, we set the path blocking and do some
1432 * reada. -EAGAIN is returned and the search must be repeated.
1435 read_block_for_search(struct btrfs_trans_handle
*trans
,
1436 struct btrfs_root
*root
, struct btrfs_path
*p
,
1437 struct extent_buffer
**eb_ret
, int level
, int slot
,
1438 struct btrfs_key
*key
)
1443 struct extent_buffer
*b
= *eb_ret
;
1444 struct extent_buffer
*tmp
;
1447 blocknr
= btrfs_node_blockptr(b
, slot
);
1448 gen
= btrfs_node_ptr_generation(b
, slot
);
1449 blocksize
= btrfs_level_size(root
, level
- 1);
1451 tmp
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
1453 if (btrfs_buffer_uptodate(tmp
, 0)) {
1454 if (btrfs_buffer_uptodate(tmp
, gen
)) {
1456 * we found an up to date block without
1463 /* the pages were up to date, but we failed
1464 * the generation number check. Do a full
1465 * read for the generation number that is correct.
1466 * We must do this without dropping locks so
1467 * we can trust our generation number
1469 free_extent_buffer(tmp
);
1470 tmp
= read_tree_block(root
, blocknr
, blocksize
, gen
);
1471 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
1475 free_extent_buffer(tmp
);
1476 btrfs_release_path(NULL
, p
);
1482 * reduce lock contention at high levels
1483 * of the btree by dropping locks before
1484 * we read. Don't release the lock on the current
1485 * level because we need to walk this node to figure
1486 * out which blocks to read.
1488 btrfs_unlock_up_safe(p
, level
+ 1);
1489 btrfs_set_path_blocking(p
);
1491 free_extent_buffer(tmp
);
1493 reada_for_search(root
, p
, level
, slot
, key
->objectid
);
1495 btrfs_release_path(NULL
, p
);
1498 tmp
= read_tree_block(root
, blocknr
, blocksize
, 0);
1501 * If the read above didn't mark this buffer up to date,
1502 * it will never end up being up to date. Set ret to EIO now
1503 * and give up so that our caller doesn't loop forever
1506 if (!btrfs_buffer_uptodate(tmp
, 0))
1508 free_extent_buffer(tmp
);
1514 * helper function for btrfs_search_slot. This does all of the checks
1515 * for node-level blocks and does any balancing required based on
1518 * If no extra work was required, zero is returned. If we had to
1519 * drop the path, -EAGAIN is returned and btrfs_search_slot must
1523 setup_nodes_for_search(struct btrfs_trans_handle
*trans
,
1524 struct btrfs_root
*root
, struct btrfs_path
*p
,
1525 struct extent_buffer
*b
, int level
, int ins_len
)
1528 if ((p
->search_for_split
|| ins_len
> 0) && btrfs_header_nritems(b
) >=
1529 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3) {
1532 sret
= reada_for_balance(root
, p
, level
);
1536 btrfs_set_path_blocking(p
);
1537 sret
= split_node(trans
, root
, p
, level
);
1538 btrfs_clear_path_blocking(p
, NULL
);
1545 b
= p
->nodes
[level
];
1546 } else if (ins_len
< 0 && btrfs_header_nritems(b
) <
1547 BTRFS_NODEPTRS_PER_BLOCK(root
) / 2) {
1550 sret
= reada_for_balance(root
, p
, level
);
1554 btrfs_set_path_blocking(p
);
1555 sret
= balance_level(trans
, root
, p
, level
);
1556 btrfs_clear_path_blocking(p
, NULL
);
1562 b
= p
->nodes
[level
];
1564 btrfs_release_path(NULL
, p
);
1567 BUG_ON(btrfs_header_nritems(b
) == 1);
1578 * look for key in the tree. path is filled in with nodes along the way
1579 * if key is found, we return zero and you can find the item in the leaf
1580 * level of the path (level 0)
1582 * If the key isn't found, the path points to the slot where it should
1583 * be inserted, and 1 is returned. If there are other errors during the
1584 * search a negative error number is returned.
1586 * if ins_len > 0, nodes and leaves will be split as we walk down the
1587 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1590 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
1591 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
1594 struct extent_buffer
*b
;
1599 int lowest_unlock
= 1;
1600 u8 lowest_level
= 0;
1602 lowest_level
= p
->lowest_level
;
1603 WARN_ON(lowest_level
&& ins_len
> 0);
1604 WARN_ON(p
->nodes
[0] != NULL
);
1610 if (p
->search_commit_root
) {
1611 b
= root
->commit_root
;
1612 extent_buffer_get(b
);
1613 if (!p
->skip_locking
)
1616 if (p
->skip_locking
)
1617 b
= btrfs_root_node(root
);
1619 b
= btrfs_lock_root_node(root
);
1623 level
= btrfs_header_level(b
);
1626 * setup the path here so we can release it under lock
1627 * contention with the cow code
1629 p
->nodes
[level
] = b
;
1630 if (!p
->skip_locking
)
1631 p
->locks
[level
] = 1;
1635 * if we don't really need to cow this block
1636 * then we don't want to set the path blocking,
1637 * so we test it here
1639 if (!should_cow_block(trans
, root
, b
))
1642 btrfs_set_path_blocking(p
);
1644 err
= btrfs_cow_block(trans
, root
, b
,
1645 p
->nodes
[level
+ 1],
1646 p
->slots
[level
+ 1], &b
);
1653 BUG_ON(!cow
&& ins_len
);
1654 if (level
!= btrfs_header_level(b
))
1656 level
= btrfs_header_level(b
);
1658 p
->nodes
[level
] = b
;
1659 if (!p
->skip_locking
)
1660 p
->locks
[level
] = 1;
1662 btrfs_clear_path_blocking(p
, NULL
);
1665 * we have a lock on b and as long as we aren't changing
1666 * the tree, there is no way to for the items in b to change.
1667 * It is safe to drop the lock on our parent before we
1668 * go through the expensive btree search on b.
1670 * If cow is true, then we might be changing slot zero,
1671 * which may require changing the parent. So, we can't
1672 * drop the lock until after we know which slot we're
1676 btrfs_unlock_up_safe(p
, level
+ 1);
1678 ret
= bin_search(b
, key
, level
, &slot
);
1682 if (ret
&& slot
> 0) {
1686 p
->slots
[level
] = slot
;
1687 err
= setup_nodes_for_search(trans
, root
, p
, b
, level
,
1695 b
= p
->nodes
[level
];
1696 slot
= p
->slots
[level
];
1698 unlock_up(p
, level
, lowest_unlock
);
1700 if (level
== lowest_level
) {
1706 err
= read_block_for_search(trans
, root
, p
,
1707 &b
, level
, slot
, key
);
1715 if (!p
->skip_locking
) {
1716 btrfs_clear_path_blocking(p
, NULL
);
1717 err
= btrfs_try_spin_lock(b
);
1720 btrfs_set_path_blocking(p
);
1722 btrfs_clear_path_blocking(p
, b
);
1726 p
->slots
[level
] = slot
;
1728 btrfs_leaf_free_space(root
, b
) < ins_len
) {
1729 btrfs_set_path_blocking(p
);
1730 err
= split_leaf(trans
, root
, key
,
1731 p
, ins_len
, ret
== 0);
1732 btrfs_clear_path_blocking(p
, NULL
);
1740 if (!p
->search_for_split
)
1741 unlock_up(p
, level
, lowest_unlock
);
1748 * we don't really know what they plan on doing with the path
1749 * from here on, so for now just mark it as blocking
1751 if (!p
->leave_spinning
)
1752 btrfs_set_path_blocking(p
);
1754 btrfs_release_path(root
, p
);
1759 * adjust the pointers going up the tree, starting at level
1760 * making sure the right key of each node is points to 'key'.
1761 * This is used after shifting pointers to the left, so it stops
1762 * fixing up pointers when a given leaf/node is not in slot 0 of the
1765 * If this fails to write a tree block, it returns -1, but continues
1766 * fixing up the blocks in ram so the tree is consistent.
1768 static int fixup_low_keys(struct btrfs_trans_handle
*trans
,
1769 struct btrfs_root
*root
, struct btrfs_path
*path
,
1770 struct btrfs_disk_key
*key
, int level
)
1774 struct extent_buffer
*t
;
1776 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1777 int tslot
= path
->slots
[i
];
1778 if (!path
->nodes
[i
])
1781 btrfs_set_node_key(t
, key
, tslot
);
1782 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
1792 * This function isn't completely safe. It's the caller's responsibility
1793 * that the new key won't break the order
1795 int btrfs_set_item_key_safe(struct btrfs_trans_handle
*trans
,
1796 struct btrfs_root
*root
, struct btrfs_path
*path
,
1797 struct btrfs_key
*new_key
)
1799 struct btrfs_disk_key disk_key
;
1800 struct extent_buffer
*eb
;
1803 eb
= path
->nodes
[0];
1804 slot
= path
->slots
[0];
1806 btrfs_item_key(eb
, &disk_key
, slot
- 1);
1807 if (comp_keys(&disk_key
, new_key
) >= 0)
1810 if (slot
< btrfs_header_nritems(eb
) - 1) {
1811 btrfs_item_key(eb
, &disk_key
, slot
+ 1);
1812 if (comp_keys(&disk_key
, new_key
) <= 0)
1816 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
1817 btrfs_set_item_key(eb
, &disk_key
, slot
);
1818 btrfs_mark_buffer_dirty(eb
);
1820 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1825 * try to push data from one node into the next node left in the
1828 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1829 * error, and > 0 if there was no room in the left hand block.
1831 static int push_node_left(struct btrfs_trans_handle
*trans
,
1832 struct btrfs_root
*root
, struct extent_buffer
*dst
,
1833 struct extent_buffer
*src
, int empty
)
1840 src_nritems
= btrfs_header_nritems(src
);
1841 dst_nritems
= btrfs_header_nritems(dst
);
1842 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1843 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1844 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1846 if (!empty
&& src_nritems
<= 8)
1849 if (push_items
<= 0)
1853 push_items
= min(src_nritems
, push_items
);
1854 if (push_items
< src_nritems
) {
1855 /* leave at least 8 pointers in the node if
1856 * we aren't going to empty it
1858 if (src_nritems
- push_items
< 8) {
1859 if (push_items
<= 8)
1865 push_items
= min(src_nritems
- 8, push_items
);
1867 copy_extent_buffer(dst
, src
,
1868 btrfs_node_key_ptr_offset(dst_nritems
),
1869 btrfs_node_key_ptr_offset(0),
1870 push_items
* sizeof(struct btrfs_key_ptr
));
1872 if (push_items
< src_nritems
) {
1873 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
1874 btrfs_node_key_ptr_offset(push_items
),
1875 (src_nritems
- push_items
) *
1876 sizeof(struct btrfs_key_ptr
));
1878 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1879 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1880 btrfs_mark_buffer_dirty(src
);
1881 btrfs_mark_buffer_dirty(dst
);
1887 * try to push data from one node into the next node right in the
1890 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
1891 * error, and > 0 if there was no room in the right hand block.
1893 * this will only push up to 1/2 the contents of the left node over
1895 static int balance_node_right(struct btrfs_trans_handle
*trans
,
1896 struct btrfs_root
*root
,
1897 struct extent_buffer
*dst
,
1898 struct extent_buffer
*src
)
1906 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1907 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1909 src_nritems
= btrfs_header_nritems(src
);
1910 dst_nritems
= btrfs_header_nritems(dst
);
1911 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1912 if (push_items
<= 0)
1915 if (src_nritems
< 4)
1918 max_push
= src_nritems
/ 2 + 1;
1919 /* don't try to empty the node */
1920 if (max_push
>= src_nritems
)
1923 if (max_push
< push_items
)
1924 push_items
= max_push
;
1926 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
1927 btrfs_node_key_ptr_offset(0),
1929 sizeof(struct btrfs_key_ptr
));
1931 copy_extent_buffer(dst
, src
,
1932 btrfs_node_key_ptr_offset(0),
1933 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
1934 push_items
* sizeof(struct btrfs_key_ptr
));
1936 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
1937 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
1939 btrfs_mark_buffer_dirty(src
);
1940 btrfs_mark_buffer_dirty(dst
);
1946 * helper function to insert a new root level in the tree.
1947 * A new node is allocated, and a single item is inserted to
1948 * point to the existing root
1950 * returns zero on success or < 0 on failure.
1952 static noinline
int insert_new_root(struct btrfs_trans_handle
*trans
,
1953 struct btrfs_root
*root
,
1954 struct btrfs_path
*path
, int level
)
1957 struct extent_buffer
*lower
;
1958 struct extent_buffer
*c
;
1959 struct extent_buffer
*old
;
1960 struct btrfs_disk_key lower_key
;
1962 BUG_ON(path
->nodes
[level
]);
1963 BUG_ON(path
->nodes
[level
-1] != root
->node
);
1965 lower
= path
->nodes
[level
-1];
1967 btrfs_item_key(lower
, &lower_key
, 0);
1969 btrfs_node_key(lower
, &lower_key
, 0);
1971 c
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
1972 root
->root_key
.objectid
, &lower_key
,
1973 level
, root
->node
->start
, 0);
1977 root_add_used(root
, root
->nodesize
);
1979 memset_extent_buffer(c
, 0, 0, sizeof(struct btrfs_header
));
1980 btrfs_set_header_nritems(c
, 1);
1981 btrfs_set_header_level(c
, level
);
1982 btrfs_set_header_bytenr(c
, c
->start
);
1983 btrfs_set_header_generation(c
, trans
->transid
);
1984 btrfs_set_header_backref_rev(c
, BTRFS_MIXED_BACKREF_REV
);
1985 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
1987 write_extent_buffer(c
, root
->fs_info
->fsid
,
1988 (unsigned long)btrfs_header_fsid(c
),
1991 write_extent_buffer(c
, root
->fs_info
->chunk_tree_uuid
,
1992 (unsigned long)btrfs_header_chunk_tree_uuid(c
),
1995 btrfs_set_node_key(c
, &lower_key
, 0);
1996 btrfs_set_node_blockptr(c
, 0, lower
->start
);
1997 lower_gen
= btrfs_header_generation(lower
);
1998 WARN_ON(lower_gen
!= trans
->transid
);
2000 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
2002 btrfs_mark_buffer_dirty(c
);
2005 rcu_assign_pointer(root
->node
, c
);
2007 /* the super has an extra ref to root->node */
2008 free_extent_buffer(old
);
2010 add_root_to_dirty_list(root
);
2011 extent_buffer_get(c
);
2012 path
->nodes
[level
] = c
;
2013 path
->locks
[level
] = 1;
2014 path
->slots
[level
] = 0;
2019 * worker function to insert a single pointer in a node.
2020 * the node should have enough room for the pointer already
2022 * slot and level indicate where you want the key to go, and
2023 * blocknr is the block the key points to.
2025 * returns zero on success and < 0 on any error
2027 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
2028 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
2029 *key
, u64 bytenr
, int slot
, int level
)
2031 struct extent_buffer
*lower
;
2034 BUG_ON(!path
->nodes
[level
]);
2035 btrfs_assert_tree_locked(path
->nodes
[level
]);
2036 lower
= path
->nodes
[level
];
2037 nritems
= btrfs_header_nritems(lower
);
2038 BUG_ON(slot
> nritems
);
2039 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
2041 if (slot
!= nritems
) {
2042 memmove_extent_buffer(lower
,
2043 btrfs_node_key_ptr_offset(slot
+ 1),
2044 btrfs_node_key_ptr_offset(slot
),
2045 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
2047 btrfs_set_node_key(lower
, key
, slot
);
2048 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
2049 WARN_ON(trans
->transid
== 0);
2050 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
2051 btrfs_set_header_nritems(lower
, nritems
+ 1);
2052 btrfs_mark_buffer_dirty(lower
);
2057 * split the node at the specified level in path in two.
2058 * The path is corrected to point to the appropriate node after the split
2060 * Before splitting this tries to make some room in the node by pushing
2061 * left and right, if either one works, it returns right away.
2063 * returns 0 on success and < 0 on failure
2065 static noinline
int split_node(struct btrfs_trans_handle
*trans
,
2066 struct btrfs_root
*root
,
2067 struct btrfs_path
*path
, int level
)
2069 struct extent_buffer
*c
;
2070 struct extent_buffer
*split
;
2071 struct btrfs_disk_key disk_key
;
2077 c
= path
->nodes
[level
];
2078 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
2079 if (c
== root
->node
) {
2080 /* trying to split the root, lets make a new one */
2081 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
2085 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
2086 c
= path
->nodes
[level
];
2087 if (!ret
&& btrfs_header_nritems(c
) <
2088 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3)
2094 c_nritems
= btrfs_header_nritems(c
);
2095 mid
= (c_nritems
+ 1) / 2;
2096 btrfs_node_key(c
, &disk_key
, mid
);
2098 split
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
2099 root
->root_key
.objectid
,
2100 &disk_key
, level
, c
->start
, 0);
2102 return PTR_ERR(split
);
2104 root_add_used(root
, root
->nodesize
);
2106 memset_extent_buffer(split
, 0, 0, sizeof(struct btrfs_header
));
2107 btrfs_set_header_level(split
, btrfs_header_level(c
));
2108 btrfs_set_header_bytenr(split
, split
->start
);
2109 btrfs_set_header_generation(split
, trans
->transid
);
2110 btrfs_set_header_backref_rev(split
, BTRFS_MIXED_BACKREF_REV
);
2111 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
2112 write_extent_buffer(split
, root
->fs_info
->fsid
,
2113 (unsigned long)btrfs_header_fsid(split
),
2115 write_extent_buffer(split
, root
->fs_info
->chunk_tree_uuid
,
2116 (unsigned long)btrfs_header_chunk_tree_uuid(split
),
2120 copy_extent_buffer(split
, c
,
2121 btrfs_node_key_ptr_offset(0),
2122 btrfs_node_key_ptr_offset(mid
),
2123 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
2124 btrfs_set_header_nritems(split
, c_nritems
- mid
);
2125 btrfs_set_header_nritems(c
, mid
);
2128 btrfs_mark_buffer_dirty(c
);
2129 btrfs_mark_buffer_dirty(split
);
2131 wret
= insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
2132 path
->slots
[level
+ 1] + 1,
2137 if (path
->slots
[level
] >= mid
) {
2138 path
->slots
[level
] -= mid
;
2139 btrfs_tree_unlock(c
);
2140 free_extent_buffer(c
);
2141 path
->nodes
[level
] = split
;
2142 path
->slots
[level
+ 1] += 1;
2144 btrfs_tree_unlock(split
);
2145 free_extent_buffer(split
);
2151 * how many bytes are required to store the items in a leaf. start
2152 * and nr indicate which items in the leaf to check. This totals up the
2153 * space used both by the item structs and the item data
2155 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
2158 int nritems
= btrfs_header_nritems(l
);
2159 int end
= min(nritems
, start
+ nr
) - 1;
2163 data_len
= btrfs_item_end_nr(l
, start
);
2164 data_len
= data_len
- btrfs_item_offset_nr(l
, end
);
2165 data_len
+= sizeof(struct btrfs_item
) * nr
;
2166 WARN_ON(data_len
< 0);
2171 * The space between the end of the leaf items and
2172 * the start of the leaf data. IOW, how much room
2173 * the leaf has left for both items and data
2175 noinline
int btrfs_leaf_free_space(struct btrfs_root
*root
,
2176 struct extent_buffer
*leaf
)
2178 int nritems
= btrfs_header_nritems(leaf
);
2180 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
2182 printk(KERN_CRIT
"leaf free space ret %d, leaf data size %lu, "
2183 "used %d nritems %d\n",
2184 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
2185 leaf_space_used(leaf
, 0, nritems
), nritems
);
2191 * min slot controls the lowest index we're willing to push to the
2192 * right. We'll push up to and including min_slot, but no lower
2194 static noinline
int __push_leaf_right(struct btrfs_trans_handle
*trans
,
2195 struct btrfs_root
*root
,
2196 struct btrfs_path
*path
,
2197 int data_size
, int empty
,
2198 struct extent_buffer
*right
,
2199 int free_space
, u32 left_nritems
,
2202 struct extent_buffer
*left
= path
->nodes
[0];
2203 struct extent_buffer
*upper
= path
->nodes
[1];
2204 struct btrfs_disk_key disk_key
;
2209 struct btrfs_item
*item
;
2218 nr
= max_t(u32
, 1, min_slot
);
2220 if (path
->slots
[0] >= left_nritems
)
2221 push_space
+= data_size
;
2223 slot
= path
->slots
[1];
2224 i
= left_nritems
- 1;
2226 item
= btrfs_item_nr(left
, i
);
2228 if (!empty
&& push_items
> 0) {
2229 if (path
->slots
[0] > i
)
2231 if (path
->slots
[0] == i
) {
2232 int space
= btrfs_leaf_free_space(root
, left
);
2233 if (space
+ push_space
* 2 > free_space
)
2238 if (path
->slots
[0] == i
)
2239 push_space
+= data_size
;
2241 if (!left
->map_token
) {
2242 map_extent_buffer(left
, (unsigned long)item
,
2243 sizeof(struct btrfs_item
),
2244 &left
->map_token
, &left
->kaddr
,
2245 &left
->map_start
, &left
->map_len
,
2249 this_item_size
= btrfs_item_size(left
, item
);
2250 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
2254 push_space
+= this_item_size
+ sizeof(*item
);
2259 if (left
->map_token
) {
2260 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
2261 left
->map_token
= NULL
;
2264 if (push_items
== 0)
2267 if (!empty
&& push_items
== left_nritems
)
2270 /* push left to right */
2271 right_nritems
= btrfs_header_nritems(right
);
2273 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
2274 push_space
-= leaf_data_end(root
, left
);
2276 /* make room in the right data area */
2277 data_end
= leaf_data_end(root
, right
);
2278 memmove_extent_buffer(right
,
2279 btrfs_leaf_data(right
) + data_end
- push_space
,
2280 btrfs_leaf_data(right
) + data_end
,
2281 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
2283 /* copy from the left data area */
2284 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
2285 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
2286 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
2289 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
2290 btrfs_item_nr_offset(0),
2291 right_nritems
* sizeof(struct btrfs_item
));
2293 /* copy the items from left to right */
2294 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
2295 btrfs_item_nr_offset(left_nritems
- push_items
),
2296 push_items
* sizeof(struct btrfs_item
));
2298 /* update the item pointers */
2299 right_nritems
+= push_items
;
2300 btrfs_set_header_nritems(right
, right_nritems
);
2301 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
2302 for (i
= 0; i
< right_nritems
; i
++) {
2303 item
= btrfs_item_nr(right
, i
);
2304 if (!right
->map_token
) {
2305 map_extent_buffer(right
, (unsigned long)item
,
2306 sizeof(struct btrfs_item
),
2307 &right
->map_token
, &right
->kaddr
,
2308 &right
->map_start
, &right
->map_len
,
2311 push_space
-= btrfs_item_size(right
, item
);
2312 btrfs_set_item_offset(right
, item
, push_space
);
2315 if (right
->map_token
) {
2316 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2317 right
->map_token
= NULL
;
2319 left_nritems
-= push_items
;
2320 btrfs_set_header_nritems(left
, left_nritems
);
2323 btrfs_mark_buffer_dirty(left
);
2325 clean_tree_block(trans
, root
, left
);
2327 btrfs_mark_buffer_dirty(right
);
2329 btrfs_item_key(right
, &disk_key
, 0);
2330 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
2331 btrfs_mark_buffer_dirty(upper
);
2333 /* then fixup the leaf pointer in the path */
2334 if (path
->slots
[0] >= left_nritems
) {
2335 path
->slots
[0] -= left_nritems
;
2336 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
2337 clean_tree_block(trans
, root
, path
->nodes
[0]);
2338 btrfs_tree_unlock(path
->nodes
[0]);
2339 free_extent_buffer(path
->nodes
[0]);
2340 path
->nodes
[0] = right
;
2341 path
->slots
[1] += 1;
2343 btrfs_tree_unlock(right
);
2344 free_extent_buffer(right
);
2349 btrfs_tree_unlock(right
);
2350 free_extent_buffer(right
);
2355 * push some data in the path leaf to the right, trying to free up at
2356 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2358 * returns 1 if the push failed because the other node didn't have enough
2359 * room, 0 if everything worked out and < 0 if there were major errors.
2361 * this will push starting from min_slot to the end of the leaf. It won't
2362 * push any slot lower than min_slot
2364 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
2365 *root
, struct btrfs_path
*path
,
2366 int min_data_size
, int data_size
,
2367 int empty
, u32 min_slot
)
2369 struct extent_buffer
*left
= path
->nodes
[0];
2370 struct extent_buffer
*right
;
2371 struct extent_buffer
*upper
;
2377 if (!path
->nodes
[1])
2380 slot
= path
->slots
[1];
2381 upper
= path
->nodes
[1];
2382 if (slot
>= btrfs_header_nritems(upper
) - 1)
2385 btrfs_assert_tree_locked(path
->nodes
[1]);
2387 right
= read_node_slot(root
, upper
, slot
+ 1);
2391 btrfs_tree_lock(right
);
2392 btrfs_set_lock_blocking(right
);
2394 free_space
= btrfs_leaf_free_space(root
, right
);
2395 if (free_space
< data_size
)
2398 /* cow and double check */
2399 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
2404 free_space
= btrfs_leaf_free_space(root
, right
);
2405 if (free_space
< data_size
)
2408 left_nritems
= btrfs_header_nritems(left
);
2409 if (left_nritems
== 0)
2412 return __push_leaf_right(trans
, root
, path
, min_data_size
, empty
,
2413 right
, free_space
, left_nritems
, min_slot
);
2415 btrfs_tree_unlock(right
);
2416 free_extent_buffer(right
);
2421 * push some data in the path leaf to the left, trying to free up at
2422 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2424 * max_slot can put a limit on how far into the leaf we'll push items. The
2425 * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
2428 static noinline
int __push_leaf_left(struct btrfs_trans_handle
*trans
,
2429 struct btrfs_root
*root
,
2430 struct btrfs_path
*path
, int data_size
,
2431 int empty
, struct extent_buffer
*left
,
2432 int free_space
, u32 right_nritems
,
2435 struct btrfs_disk_key disk_key
;
2436 struct extent_buffer
*right
= path
->nodes
[0];
2440 struct btrfs_item
*item
;
2441 u32 old_left_nritems
;
2446 u32 old_left_item_size
;
2449 nr
= min(right_nritems
, max_slot
);
2451 nr
= min(right_nritems
- 1, max_slot
);
2453 for (i
= 0; i
< nr
; i
++) {
2454 item
= btrfs_item_nr(right
, i
);
2455 if (!right
->map_token
) {
2456 map_extent_buffer(right
, (unsigned long)item
,
2457 sizeof(struct btrfs_item
),
2458 &right
->map_token
, &right
->kaddr
,
2459 &right
->map_start
, &right
->map_len
,
2463 if (!empty
&& push_items
> 0) {
2464 if (path
->slots
[0] < i
)
2466 if (path
->slots
[0] == i
) {
2467 int space
= btrfs_leaf_free_space(root
, right
);
2468 if (space
+ push_space
* 2 > free_space
)
2473 if (path
->slots
[0] == i
)
2474 push_space
+= data_size
;
2476 this_item_size
= btrfs_item_size(right
, item
);
2477 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
2481 push_space
+= this_item_size
+ sizeof(*item
);
2484 if (right
->map_token
) {
2485 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2486 right
->map_token
= NULL
;
2489 if (push_items
== 0) {
2493 if (!empty
&& push_items
== btrfs_header_nritems(right
))
2496 /* push data from right to left */
2497 copy_extent_buffer(left
, right
,
2498 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
2499 btrfs_item_nr_offset(0),
2500 push_items
* sizeof(struct btrfs_item
));
2502 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
2503 btrfs_item_offset_nr(right
, push_items
- 1);
2505 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
2506 leaf_data_end(root
, left
) - push_space
,
2507 btrfs_leaf_data(right
) +
2508 btrfs_item_offset_nr(right
, push_items
- 1),
2510 old_left_nritems
= btrfs_header_nritems(left
);
2511 BUG_ON(old_left_nritems
<= 0);
2513 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
2514 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
2517 item
= btrfs_item_nr(left
, i
);
2518 if (!left
->map_token
) {
2519 map_extent_buffer(left
, (unsigned long)item
,
2520 sizeof(struct btrfs_item
),
2521 &left
->map_token
, &left
->kaddr
,
2522 &left
->map_start
, &left
->map_len
,
2526 ioff
= btrfs_item_offset(left
, item
);
2527 btrfs_set_item_offset(left
, item
,
2528 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
));
2530 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
2531 if (left
->map_token
) {
2532 unmap_extent_buffer(left
, left
->map_token
, KM_USER1
);
2533 left
->map_token
= NULL
;
2536 /* fixup right node */
2537 if (push_items
> right_nritems
) {
2538 printk(KERN_CRIT
"push items %d nr %u\n", push_items
,
2543 if (push_items
< right_nritems
) {
2544 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
2545 leaf_data_end(root
, right
);
2546 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
2547 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
2548 btrfs_leaf_data(right
) +
2549 leaf_data_end(root
, right
), push_space
);
2551 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
2552 btrfs_item_nr_offset(push_items
),
2553 (btrfs_header_nritems(right
) - push_items
) *
2554 sizeof(struct btrfs_item
));
2556 right_nritems
-= push_items
;
2557 btrfs_set_header_nritems(right
, right_nritems
);
2558 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
2559 for (i
= 0; i
< right_nritems
; i
++) {
2560 item
= btrfs_item_nr(right
, i
);
2562 if (!right
->map_token
) {
2563 map_extent_buffer(right
, (unsigned long)item
,
2564 sizeof(struct btrfs_item
),
2565 &right
->map_token
, &right
->kaddr
,
2566 &right
->map_start
, &right
->map_len
,
2570 push_space
= push_space
- btrfs_item_size(right
, item
);
2571 btrfs_set_item_offset(right
, item
, push_space
);
2573 if (right
->map_token
) {
2574 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2575 right
->map_token
= NULL
;
2578 btrfs_mark_buffer_dirty(left
);
2580 btrfs_mark_buffer_dirty(right
);
2582 clean_tree_block(trans
, root
, right
);
2584 btrfs_item_key(right
, &disk_key
, 0);
2585 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2589 /* then fixup the leaf pointer in the path */
2590 if (path
->slots
[0] < push_items
) {
2591 path
->slots
[0] += old_left_nritems
;
2592 btrfs_tree_unlock(path
->nodes
[0]);
2593 free_extent_buffer(path
->nodes
[0]);
2594 path
->nodes
[0] = left
;
2595 path
->slots
[1] -= 1;
2597 btrfs_tree_unlock(left
);
2598 free_extent_buffer(left
);
2599 path
->slots
[0] -= push_items
;
2601 BUG_ON(path
->slots
[0] < 0);
2604 btrfs_tree_unlock(left
);
2605 free_extent_buffer(left
);
2610 * push some data in the path leaf to the left, trying to free up at
2611 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2613 * max_slot can put a limit on how far into the leaf we'll push items. The
2614 * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
2617 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
2618 *root
, struct btrfs_path
*path
, int min_data_size
,
2619 int data_size
, int empty
, u32 max_slot
)
2621 struct extent_buffer
*right
= path
->nodes
[0];
2622 struct extent_buffer
*left
;
2628 slot
= path
->slots
[1];
2631 if (!path
->nodes
[1])
2634 right_nritems
= btrfs_header_nritems(right
);
2635 if (right_nritems
== 0)
2638 btrfs_assert_tree_locked(path
->nodes
[1]);
2640 left
= read_node_slot(root
, path
->nodes
[1], slot
- 1);
2644 btrfs_tree_lock(left
);
2645 btrfs_set_lock_blocking(left
);
2647 free_space
= btrfs_leaf_free_space(root
, left
);
2648 if (free_space
< data_size
) {
2653 /* cow and double check */
2654 ret
= btrfs_cow_block(trans
, root
, left
,
2655 path
->nodes
[1], slot
- 1, &left
);
2657 /* we hit -ENOSPC, but it isn't fatal here */
2662 free_space
= btrfs_leaf_free_space(root
, left
);
2663 if (free_space
< data_size
) {
2668 return __push_leaf_left(trans
, root
, path
, min_data_size
,
2669 empty
, left
, free_space
, right_nritems
,
2672 btrfs_tree_unlock(left
);
2673 free_extent_buffer(left
);
2678 * split the path's leaf in two, making sure there is at least data_size
2679 * available for the resulting leaf level of the path.
2681 * returns 0 if all went well and < 0 on failure.
2683 static noinline
int copy_for_split(struct btrfs_trans_handle
*trans
,
2684 struct btrfs_root
*root
,
2685 struct btrfs_path
*path
,
2686 struct extent_buffer
*l
,
2687 struct extent_buffer
*right
,
2688 int slot
, int mid
, int nritems
)
2695 struct btrfs_disk_key disk_key
;
2697 nritems
= nritems
- mid
;
2698 btrfs_set_header_nritems(right
, nritems
);
2699 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
2701 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
2702 btrfs_item_nr_offset(mid
),
2703 nritems
* sizeof(struct btrfs_item
));
2705 copy_extent_buffer(right
, l
,
2706 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
2707 data_copy_size
, btrfs_leaf_data(l
) +
2708 leaf_data_end(root
, l
), data_copy_size
);
2710 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
2711 btrfs_item_end_nr(l
, mid
);
2713 for (i
= 0; i
< nritems
; i
++) {
2714 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
2717 if (!right
->map_token
) {
2718 map_extent_buffer(right
, (unsigned long)item
,
2719 sizeof(struct btrfs_item
),
2720 &right
->map_token
, &right
->kaddr
,
2721 &right
->map_start
, &right
->map_len
,
2725 ioff
= btrfs_item_offset(right
, item
);
2726 btrfs_set_item_offset(right
, item
, ioff
+ rt_data_off
);
2729 if (right
->map_token
) {
2730 unmap_extent_buffer(right
, right
->map_token
, KM_USER1
);
2731 right
->map_token
= NULL
;
2734 btrfs_set_header_nritems(l
, mid
);
2736 btrfs_item_key(right
, &disk_key
, 0);
2737 wret
= insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
2738 path
->slots
[1] + 1, 1);
2742 btrfs_mark_buffer_dirty(right
);
2743 btrfs_mark_buffer_dirty(l
);
2744 BUG_ON(path
->slots
[0] != slot
);
2747 btrfs_tree_unlock(path
->nodes
[0]);
2748 free_extent_buffer(path
->nodes
[0]);
2749 path
->nodes
[0] = right
;
2750 path
->slots
[0] -= mid
;
2751 path
->slots
[1] += 1;
2753 btrfs_tree_unlock(right
);
2754 free_extent_buffer(right
);
2757 BUG_ON(path
->slots
[0] < 0);
2763 * double splits happen when we need to insert a big item in the middle
2764 * of a leaf. A double split can leave us with 3 mostly empty leaves:
2765 * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
2768 * We avoid this by trying to push the items on either side of our target
2769 * into the adjacent leaves. If all goes well we can avoid the double split
2772 static noinline
int push_for_double_split(struct btrfs_trans_handle
*trans
,
2773 struct btrfs_root
*root
,
2774 struct btrfs_path
*path
,
2782 slot
= path
->slots
[0];
2785 * try to push all the items after our slot into the
2788 ret
= push_leaf_right(trans
, root
, path
, 1, data_size
, 0, slot
);
2795 nritems
= btrfs_header_nritems(path
->nodes
[0]);
2797 * our goal is to get our slot at the start or end of a leaf. If
2798 * we've done so we're done
2800 if (path
->slots
[0] == 0 || path
->slots
[0] == nritems
)
2803 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
2806 /* try to push all the items before our slot into the next leaf */
2807 slot
= path
->slots
[0];
2808 ret
= push_leaf_left(trans
, root
, path
, 1, data_size
, 0, slot
);
2821 * split the path's leaf in two, making sure there is at least data_size
2822 * available for the resulting leaf level of the path.
2824 * returns 0 if all went well and < 0 on failure.
2826 static noinline
int split_leaf(struct btrfs_trans_handle
*trans
,
2827 struct btrfs_root
*root
,
2828 struct btrfs_key
*ins_key
,
2829 struct btrfs_path
*path
, int data_size
,
2832 struct btrfs_disk_key disk_key
;
2833 struct extent_buffer
*l
;
2837 struct extent_buffer
*right
;
2841 int num_doubles
= 0;
2842 int tried_avoid_double
= 0;
2845 slot
= path
->slots
[0];
2846 if (extend
&& data_size
+ btrfs_item_size_nr(l
, slot
) +
2847 sizeof(struct btrfs_item
) > BTRFS_LEAF_DATA_SIZE(root
))
2850 /* first try to make some room by pushing left and right */
2852 wret
= push_leaf_right(trans
, root
, path
, data_size
,
2857 wret
= push_leaf_left(trans
, root
, path
, data_size
,
2858 data_size
, 0, (u32
)-1);
2864 /* did the pushes work? */
2865 if (btrfs_leaf_free_space(root
, l
) >= data_size
)
2869 if (!path
->nodes
[1]) {
2870 ret
= insert_new_root(trans
, root
, path
, 1);
2877 slot
= path
->slots
[0];
2878 nritems
= btrfs_header_nritems(l
);
2879 mid
= (nritems
+ 1) / 2;
2883 leaf_space_used(l
, mid
, nritems
- mid
) + data_size
>
2884 BTRFS_LEAF_DATA_SIZE(root
)) {
2885 if (slot
>= nritems
) {
2889 if (mid
!= nritems
&&
2890 leaf_space_used(l
, mid
, nritems
- mid
) +
2891 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
2892 if (data_size
&& !tried_avoid_double
)
2893 goto push_for_double
;
2899 if (leaf_space_used(l
, 0, mid
) + data_size
>
2900 BTRFS_LEAF_DATA_SIZE(root
)) {
2901 if (!extend
&& data_size
&& slot
== 0) {
2903 } else if ((extend
|| !data_size
) && slot
== 0) {
2907 if (mid
!= nritems
&&
2908 leaf_space_used(l
, mid
, nritems
- mid
) +
2909 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
2910 if (data_size
&& !tried_avoid_double
)
2911 goto push_for_double
;
2919 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2921 btrfs_item_key(l
, &disk_key
, mid
);
2923 right
= btrfs_alloc_free_block(trans
, root
, root
->leafsize
, 0,
2924 root
->root_key
.objectid
,
2925 &disk_key
, 0, l
->start
, 0);
2927 return PTR_ERR(right
);
2929 root_add_used(root
, root
->leafsize
);
2931 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
2932 btrfs_set_header_bytenr(right
, right
->start
);
2933 btrfs_set_header_generation(right
, trans
->transid
);
2934 btrfs_set_header_backref_rev(right
, BTRFS_MIXED_BACKREF_REV
);
2935 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
2936 btrfs_set_header_level(right
, 0);
2937 write_extent_buffer(right
, root
->fs_info
->fsid
,
2938 (unsigned long)btrfs_header_fsid(right
),
2941 write_extent_buffer(right
, root
->fs_info
->chunk_tree_uuid
,
2942 (unsigned long)btrfs_header_chunk_tree_uuid(right
),
2947 btrfs_set_header_nritems(right
, 0);
2948 wret
= insert_ptr(trans
, root
, path
,
2949 &disk_key
, right
->start
,
2950 path
->slots
[1] + 1, 1);
2954 btrfs_tree_unlock(path
->nodes
[0]);
2955 free_extent_buffer(path
->nodes
[0]);
2956 path
->nodes
[0] = right
;
2958 path
->slots
[1] += 1;
2960 btrfs_set_header_nritems(right
, 0);
2961 wret
= insert_ptr(trans
, root
, path
,
2967 btrfs_tree_unlock(path
->nodes
[0]);
2968 free_extent_buffer(path
->nodes
[0]);
2969 path
->nodes
[0] = right
;
2971 if (path
->slots
[1] == 0) {
2972 wret
= fixup_low_keys(trans
, root
,
2973 path
, &disk_key
, 1);
2978 btrfs_mark_buffer_dirty(right
);
2982 ret
= copy_for_split(trans
, root
, path
, l
, right
, slot
, mid
, nritems
);
2986 BUG_ON(num_doubles
!= 0);
2994 push_for_double_split(trans
, root
, path
, data_size
);
2995 tried_avoid_double
= 1;
2996 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
3001 static noinline
int setup_leaf_for_split(struct btrfs_trans_handle
*trans
,
3002 struct btrfs_root
*root
,
3003 struct btrfs_path
*path
, int ins_len
)
3005 struct btrfs_key key
;
3006 struct extent_buffer
*leaf
;
3007 struct btrfs_file_extent_item
*fi
;
3012 leaf
= path
->nodes
[0];
3013 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3015 BUG_ON(key
.type
!= BTRFS_EXTENT_DATA_KEY
&&
3016 key
.type
!= BTRFS_EXTENT_CSUM_KEY
);
3018 if (btrfs_leaf_free_space(root
, leaf
) >= ins_len
)
3021 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
3022 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
3023 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3024 struct btrfs_file_extent_item
);
3025 extent_len
= btrfs_file_extent_num_bytes(leaf
, fi
);
3027 btrfs_release_path(root
, path
);
3029 path
->keep_locks
= 1;
3030 path
->search_for_split
= 1;
3031 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
3032 path
->search_for_split
= 0;
3037 leaf
= path
->nodes
[0];
3038 /* if our item isn't there or got smaller, return now */
3039 if (ret
> 0 || item_size
!= btrfs_item_size_nr(leaf
, path
->slots
[0]))
3042 /* the leaf has changed, it now has room. return now */
3043 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= ins_len
)
3046 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
3047 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3048 struct btrfs_file_extent_item
);
3049 if (extent_len
!= btrfs_file_extent_num_bytes(leaf
, fi
))
3053 btrfs_set_path_blocking(path
);
3054 ret
= split_leaf(trans
, root
, &key
, path
, ins_len
, 1);
3058 path
->keep_locks
= 0;
3059 btrfs_unlock_up_safe(path
, 1);
3062 path
->keep_locks
= 0;
3066 static noinline
int split_item(struct btrfs_trans_handle
*trans
,
3067 struct btrfs_root
*root
,
3068 struct btrfs_path
*path
,
3069 struct btrfs_key
*new_key
,
3070 unsigned long split_offset
)
3072 struct extent_buffer
*leaf
;
3073 struct btrfs_item
*item
;
3074 struct btrfs_item
*new_item
;
3080 struct btrfs_disk_key disk_key
;
3082 leaf
= path
->nodes
[0];
3083 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < sizeof(struct btrfs_item
));
3085 btrfs_set_path_blocking(path
);
3087 item
= btrfs_item_nr(leaf
, path
->slots
[0]);
3088 orig_offset
= btrfs_item_offset(leaf
, item
);
3089 item_size
= btrfs_item_size(leaf
, item
);
3091 buf
= kmalloc(item_size
, GFP_NOFS
);
3095 read_extent_buffer(leaf
, buf
, btrfs_item_ptr_offset(leaf
,
3096 path
->slots
[0]), item_size
);
3098 slot
= path
->slots
[0] + 1;
3099 nritems
= btrfs_header_nritems(leaf
);
3100 if (slot
!= nritems
) {
3101 /* shift the items */
3102 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ 1),
3103 btrfs_item_nr_offset(slot
),
3104 (nritems
- slot
) * sizeof(struct btrfs_item
));
3107 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
3108 btrfs_set_item_key(leaf
, &disk_key
, slot
);
3110 new_item
= btrfs_item_nr(leaf
, slot
);
3112 btrfs_set_item_offset(leaf
, new_item
, orig_offset
);
3113 btrfs_set_item_size(leaf
, new_item
, item_size
- split_offset
);
3115 btrfs_set_item_offset(leaf
, item
,
3116 orig_offset
+ item_size
- split_offset
);
3117 btrfs_set_item_size(leaf
, item
, split_offset
);
3119 btrfs_set_header_nritems(leaf
, nritems
+ 1);
3121 /* write the data for the start of the original item */
3122 write_extent_buffer(leaf
, buf
,
3123 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
3126 /* write the data for the new item */
3127 write_extent_buffer(leaf
, buf
+ split_offset
,
3128 btrfs_item_ptr_offset(leaf
, slot
),
3129 item_size
- split_offset
);
3130 btrfs_mark_buffer_dirty(leaf
);
3132 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
3138 * This function splits a single item into two items,
3139 * giving 'new_key' to the new item and splitting the
3140 * old one at split_offset (from the start of the item).
3142 * The path may be released by this operation. After
3143 * the split, the path is pointing to the old item. The
3144 * new item is going to be in the same node as the old one.
3146 * Note, the item being split must be smaller enough to live alone on
3147 * a tree block with room for one extra struct btrfs_item
3149 * This allows us to split the item in place, keeping a lock on the
3150 * leaf the entire time.
3152 int btrfs_split_item(struct btrfs_trans_handle
*trans
,
3153 struct btrfs_root
*root
,
3154 struct btrfs_path
*path
,
3155 struct btrfs_key
*new_key
,
3156 unsigned long split_offset
)
3159 ret
= setup_leaf_for_split(trans
, root
, path
,
3160 sizeof(struct btrfs_item
));
3164 ret
= split_item(trans
, root
, path
, new_key
, split_offset
);
3169 * This function duplicate a item, giving 'new_key' to the new item.
3170 * It guarantees both items live in the same tree leaf and the new item
3171 * is contiguous with the original item.
3173 * This allows us to split file extent in place, keeping a lock on the
3174 * leaf the entire time.
3176 int btrfs_duplicate_item(struct btrfs_trans_handle
*trans
,
3177 struct btrfs_root
*root
,
3178 struct btrfs_path
*path
,
3179 struct btrfs_key
*new_key
)
3181 struct extent_buffer
*leaf
;
3185 leaf
= path
->nodes
[0];
3186 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
3187 ret
= setup_leaf_for_split(trans
, root
, path
,
3188 item_size
+ sizeof(struct btrfs_item
));
3193 ret
= setup_items_for_insert(trans
, root
, path
, new_key
, &item_size
,
3194 item_size
, item_size
+
3195 sizeof(struct btrfs_item
), 1);
3198 leaf
= path
->nodes
[0];
3199 memcpy_extent_buffer(leaf
,
3200 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
3201 btrfs_item_ptr_offset(leaf
, path
->slots
[0] - 1),
3207 * make the item pointed to by the path smaller. new_size indicates
3208 * how small to make it, and from_end tells us if we just chop bytes
3209 * off the end of the item or if we shift the item to chop bytes off
3212 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
3213 struct btrfs_root
*root
,
3214 struct btrfs_path
*path
,
3215 u32 new_size
, int from_end
)
3219 struct extent_buffer
*leaf
;
3220 struct btrfs_item
*item
;
3222 unsigned int data_end
;
3223 unsigned int old_data_start
;
3224 unsigned int old_size
;
3225 unsigned int size_diff
;
3228 leaf
= path
->nodes
[0];
3229 slot
= path
->slots
[0];
3231 old_size
= btrfs_item_size_nr(leaf
, slot
);
3232 if (old_size
== new_size
)
3235 nritems
= btrfs_header_nritems(leaf
);
3236 data_end
= leaf_data_end(root
, leaf
);
3238 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
3240 size_diff
= old_size
- new_size
;
3243 BUG_ON(slot
>= nritems
);
3246 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3248 /* first correct the data pointers */
3249 for (i
= slot
; i
< nritems
; i
++) {
3251 item
= btrfs_item_nr(leaf
, i
);
3253 if (!leaf
->map_token
) {
3254 map_extent_buffer(leaf
, (unsigned long)item
,
3255 sizeof(struct btrfs_item
),
3256 &leaf
->map_token
, &leaf
->kaddr
,
3257 &leaf
->map_start
, &leaf
->map_len
,
3261 ioff
= btrfs_item_offset(leaf
, item
);
3262 btrfs_set_item_offset(leaf
, item
, ioff
+ size_diff
);
3265 if (leaf
->map_token
) {
3266 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
3267 leaf
->map_token
= NULL
;
3270 /* shift the data */
3272 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3273 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
3274 data_end
, old_data_start
+ new_size
- data_end
);
3276 struct btrfs_disk_key disk_key
;
3279 btrfs_item_key(leaf
, &disk_key
, slot
);
3281 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
3283 struct btrfs_file_extent_item
*fi
;
3285 fi
= btrfs_item_ptr(leaf
, slot
,
3286 struct btrfs_file_extent_item
);
3287 fi
= (struct btrfs_file_extent_item
*)(
3288 (unsigned long)fi
- size_diff
);
3290 if (btrfs_file_extent_type(leaf
, fi
) ==
3291 BTRFS_FILE_EXTENT_INLINE
) {
3292 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
3293 memmove_extent_buffer(leaf
, ptr
,
3295 offsetof(struct btrfs_file_extent_item
,
3300 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3301 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
3302 data_end
, old_data_start
- data_end
);
3304 offset
= btrfs_disk_key_offset(&disk_key
);
3305 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
3306 btrfs_set_item_key(leaf
, &disk_key
, slot
);
3308 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3311 item
= btrfs_item_nr(leaf
, slot
);
3312 btrfs_set_item_size(leaf
, item
, new_size
);
3313 btrfs_mark_buffer_dirty(leaf
);
3316 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3317 btrfs_print_leaf(root
, leaf
);
3324 * make the item pointed to by the path bigger, data_size is the new size.
3326 int btrfs_extend_item(struct btrfs_trans_handle
*trans
,
3327 struct btrfs_root
*root
, struct btrfs_path
*path
,
3332 struct extent_buffer
*leaf
;
3333 struct btrfs_item
*item
;
3335 unsigned int data_end
;
3336 unsigned int old_data
;
3337 unsigned int old_size
;
3340 leaf
= path
->nodes
[0];
3342 nritems
= btrfs_header_nritems(leaf
);
3343 data_end
= leaf_data_end(root
, leaf
);
3345 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
3346 btrfs_print_leaf(root
, leaf
);
3349 slot
= path
->slots
[0];
3350 old_data
= btrfs_item_end_nr(leaf
, slot
);
3353 if (slot
>= nritems
) {
3354 btrfs_print_leaf(root
, leaf
);
3355 printk(KERN_CRIT
"slot %d too large, nritems %d\n",
3361 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3363 /* first correct the data pointers */
3364 for (i
= slot
; i
< nritems
; i
++) {
3366 item
= btrfs_item_nr(leaf
, i
);
3368 if (!leaf
->map_token
) {
3369 map_extent_buffer(leaf
, (unsigned long)item
,
3370 sizeof(struct btrfs_item
),
3371 &leaf
->map_token
, &leaf
->kaddr
,
3372 &leaf
->map_start
, &leaf
->map_len
,
3375 ioff
= btrfs_item_offset(leaf
, item
);
3376 btrfs_set_item_offset(leaf
, item
, ioff
- data_size
);
3379 if (leaf
->map_token
) {
3380 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
3381 leaf
->map_token
= NULL
;
3384 /* shift the data */
3385 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3386 data_end
- data_size
, btrfs_leaf_data(leaf
) +
3387 data_end
, old_data
- data_end
);
3389 data_end
= old_data
;
3390 old_size
= btrfs_item_size_nr(leaf
, slot
);
3391 item
= btrfs_item_nr(leaf
, slot
);
3392 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
3393 btrfs_mark_buffer_dirty(leaf
);
3396 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3397 btrfs_print_leaf(root
, leaf
);
3404 * Given a key and some data, insert items into the tree.
3405 * This does all the path init required, making room in the tree if needed.
3406 * Returns the number of keys that were inserted.
3408 int btrfs_insert_some_items(struct btrfs_trans_handle
*trans
,
3409 struct btrfs_root
*root
,
3410 struct btrfs_path
*path
,
3411 struct btrfs_key
*cpu_key
, u32
*data_size
,
3414 struct extent_buffer
*leaf
;
3415 struct btrfs_item
*item
;
3422 unsigned int data_end
;
3423 struct btrfs_disk_key disk_key
;
3424 struct btrfs_key found_key
;
3426 for (i
= 0; i
< nr
; i
++) {
3427 if (total_size
+ data_size
[i
] + sizeof(struct btrfs_item
) >
3428 BTRFS_LEAF_DATA_SIZE(root
)) {
3432 total_data
+= data_size
[i
];
3433 total_size
+= data_size
[i
] + sizeof(struct btrfs_item
);
3437 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
3443 leaf
= path
->nodes
[0];
3445 nritems
= btrfs_header_nritems(leaf
);
3446 data_end
= leaf_data_end(root
, leaf
);
3448 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
3449 for (i
= nr
; i
>= 0; i
--) {
3450 total_data
-= data_size
[i
];
3451 total_size
-= data_size
[i
] + sizeof(struct btrfs_item
);
3452 if (total_size
< btrfs_leaf_free_space(root
, leaf
))
3458 slot
= path
->slots
[0];
3461 if (slot
!= nritems
) {
3462 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
3464 item
= btrfs_item_nr(leaf
, slot
);
3465 btrfs_item_key_to_cpu(leaf
, &found_key
, slot
);
3467 /* figure out how many keys we can insert in here */
3468 total_data
= data_size
[0];
3469 for (i
= 1; i
< nr
; i
++) {
3470 if (btrfs_comp_cpu_keys(&found_key
, cpu_key
+ i
) <= 0)
3472 total_data
+= data_size
[i
];
3476 if (old_data
< data_end
) {
3477 btrfs_print_leaf(root
, leaf
);
3478 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
3479 slot
, old_data
, data_end
);
3483 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3485 /* first correct the data pointers */
3486 WARN_ON(leaf
->map_token
);
3487 for (i
= slot
; i
< nritems
; i
++) {
3490 item
= btrfs_item_nr(leaf
, i
);
3491 if (!leaf
->map_token
) {
3492 map_extent_buffer(leaf
, (unsigned long)item
,
3493 sizeof(struct btrfs_item
),
3494 &leaf
->map_token
, &leaf
->kaddr
,
3495 &leaf
->map_start
, &leaf
->map_len
,
3499 ioff
= btrfs_item_offset(leaf
, item
);
3500 btrfs_set_item_offset(leaf
, item
, ioff
- total_data
);
3502 if (leaf
->map_token
) {
3503 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
3504 leaf
->map_token
= NULL
;
3507 /* shift the items */
3508 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
3509 btrfs_item_nr_offset(slot
),
3510 (nritems
- slot
) * sizeof(struct btrfs_item
));
3512 /* shift the data */
3513 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3514 data_end
- total_data
, btrfs_leaf_data(leaf
) +
3515 data_end
, old_data
- data_end
);
3516 data_end
= old_data
;
3519 * this sucks but it has to be done, if we are inserting at
3520 * the end of the leaf only insert 1 of the items, since we
3521 * have no way of knowing whats on the next leaf and we'd have
3522 * to drop our current locks to figure it out
3527 /* setup the item for the new data */
3528 for (i
= 0; i
< nr
; i
++) {
3529 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
3530 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
3531 item
= btrfs_item_nr(leaf
, slot
+ i
);
3532 btrfs_set_item_offset(leaf
, item
, data_end
- data_size
[i
]);
3533 data_end
-= data_size
[i
];
3534 btrfs_set_item_size(leaf
, item
, data_size
[i
]);
3536 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
3537 btrfs_mark_buffer_dirty(leaf
);
3541 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
3542 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3545 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3546 btrfs_print_leaf(root
, leaf
);
3556 * this is a helper for btrfs_insert_empty_items, the main goal here is
3557 * to save stack depth by doing the bulk of the work in a function
3558 * that doesn't call btrfs_search_slot
3560 static noinline_for_stack
int
3561 setup_items_for_insert(struct btrfs_trans_handle
*trans
,
3562 struct btrfs_root
*root
, struct btrfs_path
*path
,
3563 struct btrfs_key
*cpu_key
, u32
*data_size
,
3564 u32 total_data
, u32 total_size
, int nr
)
3566 struct btrfs_item
*item
;
3569 unsigned int data_end
;
3570 struct btrfs_disk_key disk_key
;
3572 struct extent_buffer
*leaf
;
3575 leaf
= path
->nodes
[0];
3576 slot
= path
->slots
[0];
3578 nritems
= btrfs_header_nritems(leaf
);
3579 data_end
= leaf_data_end(root
, leaf
);
3581 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
3582 btrfs_print_leaf(root
, leaf
);
3583 printk(KERN_CRIT
"not enough freespace need %u have %d\n",
3584 total_size
, btrfs_leaf_free_space(root
, leaf
));
3588 if (slot
!= nritems
) {
3589 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
3591 if (old_data
< data_end
) {
3592 btrfs_print_leaf(root
, leaf
);
3593 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
3594 slot
, old_data
, data_end
);
3598 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3600 /* first correct the data pointers */
3601 WARN_ON(leaf
->map_token
);
3602 for (i
= slot
; i
< nritems
; i
++) {
3605 item
= btrfs_item_nr(leaf
, i
);
3606 if (!leaf
->map_token
) {
3607 map_extent_buffer(leaf
, (unsigned long)item
,
3608 sizeof(struct btrfs_item
),
3609 &leaf
->map_token
, &leaf
->kaddr
,
3610 &leaf
->map_start
, &leaf
->map_len
,
3614 ioff
= btrfs_item_offset(leaf
, item
);
3615 btrfs_set_item_offset(leaf
, item
, ioff
- total_data
);
3617 if (leaf
->map_token
) {
3618 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
3619 leaf
->map_token
= NULL
;
3622 /* shift the items */
3623 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
3624 btrfs_item_nr_offset(slot
),
3625 (nritems
- slot
) * sizeof(struct btrfs_item
));
3627 /* shift the data */
3628 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3629 data_end
- total_data
, btrfs_leaf_data(leaf
) +
3630 data_end
, old_data
- data_end
);
3631 data_end
= old_data
;
3634 /* setup the item for the new data */
3635 for (i
= 0; i
< nr
; i
++) {
3636 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
3637 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
3638 item
= btrfs_item_nr(leaf
, slot
+ i
);
3639 btrfs_set_item_offset(leaf
, item
, data_end
- data_size
[i
]);
3640 data_end
-= data_size
[i
];
3641 btrfs_set_item_size(leaf
, item
, data_size
[i
]);
3644 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
3648 struct btrfs_disk_key disk_key
;
3649 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
3650 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3652 btrfs_unlock_up_safe(path
, 1);
3653 btrfs_mark_buffer_dirty(leaf
);
3655 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3656 btrfs_print_leaf(root
, leaf
);
3663 * Given a key and some data, insert items into the tree.
3664 * This does all the path init required, making room in the tree if needed.
3666 int btrfs_insert_empty_items(struct btrfs_trans_handle
*trans
,
3667 struct btrfs_root
*root
,
3668 struct btrfs_path
*path
,
3669 struct btrfs_key
*cpu_key
, u32
*data_size
,
3678 for (i
= 0; i
< nr
; i
++)
3679 total_data
+= data_size
[i
];
3681 total_size
= total_data
+ (nr
* sizeof(struct btrfs_item
));
3682 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
3688 slot
= path
->slots
[0];
3691 ret
= setup_items_for_insert(trans
, root
, path
, cpu_key
, data_size
,
3692 total_data
, total_size
, nr
);
3699 * Given a key and some data, insert an item into the tree.
3700 * This does all the path init required, making room in the tree if needed.
3702 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
3703 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
3707 struct btrfs_path
*path
;
3708 struct extent_buffer
*leaf
;
3711 path
= btrfs_alloc_path();
3714 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
3716 leaf
= path
->nodes
[0];
3717 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
3718 write_extent_buffer(leaf
, data
, ptr
, data_size
);
3719 btrfs_mark_buffer_dirty(leaf
);
3721 btrfs_free_path(path
);
3726 * delete the pointer from a given node.
3728 * the tree should have been previously balanced so the deletion does not
3731 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
3732 struct btrfs_path
*path
, int level
, int slot
)
3734 struct extent_buffer
*parent
= path
->nodes
[level
];
3739 nritems
= btrfs_header_nritems(parent
);
3740 if (slot
!= nritems
- 1) {
3741 memmove_extent_buffer(parent
,
3742 btrfs_node_key_ptr_offset(slot
),
3743 btrfs_node_key_ptr_offset(slot
+ 1),
3744 sizeof(struct btrfs_key_ptr
) *
3745 (nritems
- slot
- 1));
3748 btrfs_set_header_nritems(parent
, nritems
);
3749 if (nritems
== 0 && parent
== root
->node
) {
3750 BUG_ON(btrfs_header_level(root
->node
) != 1);
3751 /* just turn the root into a leaf and break */
3752 btrfs_set_header_level(root
->node
, 0);
3753 } else if (slot
== 0) {
3754 struct btrfs_disk_key disk_key
;
3756 btrfs_node_key(parent
, &disk_key
, 0);
3757 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, level
+ 1);
3761 btrfs_mark_buffer_dirty(parent
);
3766 * a helper function to delete the leaf pointed to by path->slots[1] and
3769 * This deletes the pointer in path->nodes[1] and frees the leaf
3770 * block extent. zero is returned if it all worked out, < 0 otherwise.
3772 * The path must have already been setup for deleting the leaf, including
3773 * all the proper balancing. path->nodes[1] must be locked.
3775 static noinline
int btrfs_del_leaf(struct btrfs_trans_handle
*trans
,
3776 struct btrfs_root
*root
,
3777 struct btrfs_path
*path
,
3778 struct extent_buffer
*leaf
)
3782 WARN_ON(btrfs_header_generation(leaf
) != trans
->transid
);
3783 ret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
3788 * btrfs_free_extent is expensive, we want to make sure we
3789 * aren't holding any locks when we call it
3791 btrfs_unlock_up_safe(path
, 0);
3793 root_sub_used(root
, leaf
->len
);
3795 btrfs_free_tree_block(trans
, root
, leaf
, 0, 1);
3799 * delete the item at the leaf level in path. If that empties
3800 * the leaf, remove it from the tree
3802 int btrfs_del_items(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
3803 struct btrfs_path
*path
, int slot
, int nr
)
3805 struct extent_buffer
*leaf
;
3806 struct btrfs_item
*item
;
3814 leaf
= path
->nodes
[0];
3815 last_off
= btrfs_item_offset_nr(leaf
, slot
+ nr
- 1);
3817 for (i
= 0; i
< nr
; i
++)
3818 dsize
+= btrfs_item_size_nr(leaf
, slot
+ i
);
3820 nritems
= btrfs_header_nritems(leaf
);
3822 if (slot
+ nr
!= nritems
) {
3823 int data_end
= leaf_data_end(root
, leaf
);
3825 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3827 btrfs_leaf_data(leaf
) + data_end
,
3828 last_off
- data_end
);
3830 for (i
= slot
+ nr
; i
< nritems
; i
++) {
3833 item
= btrfs_item_nr(leaf
, i
);
3834 if (!leaf
->map_token
) {
3835 map_extent_buffer(leaf
, (unsigned long)item
,
3836 sizeof(struct btrfs_item
),
3837 &leaf
->map_token
, &leaf
->kaddr
,
3838 &leaf
->map_start
, &leaf
->map_len
,
3841 ioff
= btrfs_item_offset(leaf
, item
);
3842 btrfs_set_item_offset(leaf
, item
, ioff
+ dsize
);
3845 if (leaf
->map_token
) {
3846 unmap_extent_buffer(leaf
, leaf
->map_token
, KM_USER1
);
3847 leaf
->map_token
= NULL
;
3850 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
3851 btrfs_item_nr_offset(slot
+ nr
),
3852 sizeof(struct btrfs_item
) *
3853 (nritems
- slot
- nr
));
3855 btrfs_set_header_nritems(leaf
, nritems
- nr
);
3858 /* delete the leaf if we've emptied it */
3860 if (leaf
== root
->node
) {
3861 btrfs_set_header_level(leaf
, 0);
3863 btrfs_set_path_blocking(path
);
3864 clean_tree_block(trans
, root
, leaf
);
3865 ret
= btrfs_del_leaf(trans
, root
, path
, leaf
);
3869 int used
= leaf_space_used(leaf
, 0, nritems
);
3871 struct btrfs_disk_key disk_key
;
3873 btrfs_item_key(leaf
, &disk_key
, 0);
3874 wret
= fixup_low_keys(trans
, root
, path
,
3880 /* delete the leaf if it is mostly empty */
3881 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
3882 /* push_leaf_left fixes the path.
3883 * make sure the path still points to our leaf
3884 * for possible call to del_ptr below
3886 slot
= path
->slots
[1];
3887 extent_buffer_get(leaf
);
3889 btrfs_set_path_blocking(path
);
3890 wret
= push_leaf_left(trans
, root
, path
, 1, 1,
3892 if (wret
< 0 && wret
!= -ENOSPC
)
3895 if (path
->nodes
[0] == leaf
&&
3896 btrfs_header_nritems(leaf
)) {
3897 wret
= push_leaf_right(trans
, root
, path
, 1,
3899 if (wret
< 0 && wret
!= -ENOSPC
)
3903 if (btrfs_header_nritems(leaf
) == 0) {
3904 path
->slots
[1] = slot
;
3905 ret
= btrfs_del_leaf(trans
, root
, path
, leaf
);
3907 free_extent_buffer(leaf
);
3909 /* if we're still in the path, make sure
3910 * we're dirty. Otherwise, one of the
3911 * push_leaf functions must have already
3912 * dirtied this buffer
3914 if (path
->nodes
[0] == leaf
)
3915 btrfs_mark_buffer_dirty(leaf
);
3916 free_extent_buffer(leaf
);
3919 btrfs_mark_buffer_dirty(leaf
);
3926 * search the tree again to find a leaf with lesser keys
3927 * returns 0 if it found something or 1 if there are no lesser leaves.
3928 * returns < 0 on io errors.
3930 * This may release the path, and so you may lose any locks held at the
3933 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
3935 struct btrfs_key key
;
3936 struct btrfs_disk_key found_key
;
3939 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, 0);
3943 else if (key
.type
> 0)
3945 else if (key
.objectid
> 0)
3950 btrfs_release_path(root
, path
);
3951 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3954 btrfs_item_key(path
->nodes
[0], &found_key
, 0);
3955 ret
= comp_keys(&found_key
, &key
);
3962 * A helper function to walk down the tree starting at min_key, and looking
3963 * for nodes or leaves that are either in cache or have a minimum
3964 * transaction id. This is used by the btree defrag code, and tree logging
3966 * This does not cow, but it does stuff the starting key it finds back
3967 * into min_key, so you can call btrfs_search_slot with cow=1 on the
3968 * key and get a writable path.
3970 * This does lock as it descends, and path->keep_locks should be set
3971 * to 1 by the caller.
3973 * This honors path->lowest_level to prevent descent past a given level
3976 * min_trans indicates the oldest transaction that you are interested
3977 * in walking through. Any nodes or leaves older than min_trans are
3978 * skipped over (without reading them).
3980 * returns zero if something useful was found, < 0 on error and 1 if there
3981 * was nothing in the tree that matched the search criteria.
3983 int btrfs_search_forward(struct btrfs_root
*root
, struct btrfs_key
*min_key
,
3984 struct btrfs_key
*max_key
,
3985 struct btrfs_path
*path
, int cache_only
,
3988 struct extent_buffer
*cur
;
3989 struct btrfs_key found_key
;
3996 WARN_ON(!path
->keep_locks
);
3998 cur
= btrfs_lock_root_node(root
);
3999 level
= btrfs_header_level(cur
);
4000 WARN_ON(path
->nodes
[level
]);
4001 path
->nodes
[level
] = cur
;
4002 path
->locks
[level
] = 1;
4004 if (btrfs_header_generation(cur
) < min_trans
) {
4009 nritems
= btrfs_header_nritems(cur
);
4010 level
= btrfs_header_level(cur
);
4011 sret
= bin_search(cur
, min_key
, level
, &slot
);
4013 /* at the lowest level, we're done, setup the path and exit */
4014 if (level
== path
->lowest_level
) {
4015 if (slot
>= nritems
)
4018 path
->slots
[level
] = slot
;
4019 btrfs_item_key_to_cpu(cur
, &found_key
, slot
);
4022 if (sret
&& slot
> 0)
4025 * check this node pointer against the cache_only and
4026 * min_trans parameters. If it isn't in cache or is too
4027 * old, skip to the next one.
4029 while (slot
< nritems
) {
4032 struct extent_buffer
*tmp
;
4033 struct btrfs_disk_key disk_key
;
4035 blockptr
= btrfs_node_blockptr(cur
, slot
);
4036 gen
= btrfs_node_ptr_generation(cur
, slot
);
4037 if (gen
< min_trans
) {
4045 btrfs_node_key(cur
, &disk_key
, slot
);
4046 if (comp_keys(&disk_key
, max_key
) >= 0) {
4052 tmp
= btrfs_find_tree_block(root
, blockptr
,
4053 btrfs_level_size(root
, level
- 1));
4055 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
4056 free_extent_buffer(tmp
);
4060 free_extent_buffer(tmp
);
4065 * we didn't find a candidate key in this node, walk forward
4066 * and find another one
4068 if (slot
>= nritems
) {
4069 path
->slots
[level
] = slot
;
4070 btrfs_set_path_blocking(path
);
4071 sret
= btrfs_find_next_key(root
, path
, min_key
, level
,
4072 cache_only
, min_trans
);
4074 btrfs_release_path(root
, path
);
4080 /* save our key for returning back */
4081 btrfs_node_key_to_cpu(cur
, &found_key
, slot
);
4082 path
->slots
[level
] = slot
;
4083 if (level
== path
->lowest_level
) {
4085 unlock_up(path
, level
, 1);
4088 btrfs_set_path_blocking(path
);
4089 cur
= read_node_slot(root
, cur
, slot
);
4091 btrfs_tree_lock(cur
);
4093 path
->locks
[level
- 1] = 1;
4094 path
->nodes
[level
- 1] = cur
;
4095 unlock_up(path
, level
, 1);
4096 btrfs_clear_path_blocking(path
, NULL
);
4100 memcpy(min_key
, &found_key
, sizeof(found_key
));
4101 btrfs_set_path_blocking(path
);
4106 * this is similar to btrfs_next_leaf, but does not try to preserve
4107 * and fixup the path. It looks for and returns the next key in the
4108 * tree based on the current path and the cache_only and min_trans
4111 * 0 is returned if another key is found, < 0 if there are any errors
4112 * and 1 is returned if there are no higher keys in the tree
4114 * path->keep_locks should be set to 1 on the search made before
4115 * calling this function.
4117 int btrfs_find_next_key(struct btrfs_root
*root
, struct btrfs_path
*path
,
4118 struct btrfs_key
*key
, int level
,
4119 int cache_only
, u64 min_trans
)
4122 struct extent_buffer
*c
;
4124 WARN_ON(!path
->keep_locks
);
4125 while (level
< BTRFS_MAX_LEVEL
) {
4126 if (!path
->nodes
[level
])
4129 slot
= path
->slots
[level
] + 1;
4130 c
= path
->nodes
[level
];
4132 if (slot
>= btrfs_header_nritems(c
)) {
4135 struct btrfs_key cur_key
;
4136 if (level
+ 1 >= BTRFS_MAX_LEVEL
||
4137 !path
->nodes
[level
+ 1])
4140 if (path
->locks
[level
+ 1]) {
4145 slot
= btrfs_header_nritems(c
) - 1;
4147 btrfs_item_key_to_cpu(c
, &cur_key
, slot
);
4149 btrfs_node_key_to_cpu(c
, &cur_key
, slot
);
4151 orig_lowest
= path
->lowest_level
;
4152 btrfs_release_path(root
, path
);
4153 path
->lowest_level
= level
;
4154 ret
= btrfs_search_slot(NULL
, root
, &cur_key
, path
,
4156 path
->lowest_level
= orig_lowest
;
4160 c
= path
->nodes
[level
];
4161 slot
= path
->slots
[level
];
4168 btrfs_item_key_to_cpu(c
, key
, slot
);
4170 u64 blockptr
= btrfs_node_blockptr(c
, slot
);
4171 u64 gen
= btrfs_node_ptr_generation(c
, slot
);
4174 struct extent_buffer
*cur
;
4175 cur
= btrfs_find_tree_block(root
, blockptr
,
4176 btrfs_level_size(root
, level
- 1));
4177 if (!cur
|| !btrfs_buffer_uptodate(cur
, gen
)) {
4180 free_extent_buffer(cur
);
4183 free_extent_buffer(cur
);
4185 if (gen
< min_trans
) {
4189 btrfs_node_key_to_cpu(c
, key
, slot
);
4197 * search the tree again to find a leaf with greater keys
4198 * returns 0 if it found something or 1 if there are no greater leaves.
4199 * returns < 0 on io errors.
4201 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
4205 struct extent_buffer
*c
;
4206 struct extent_buffer
*next
;
4207 struct btrfs_key key
;
4210 int old_spinning
= path
->leave_spinning
;
4211 int force_blocking
= 0;
4213 nritems
= btrfs_header_nritems(path
->nodes
[0]);
4218 * we take the blocks in an order that upsets lockdep. Using
4219 * blocking mode is the only way around it.
4221 #ifdef CONFIG_DEBUG_LOCK_ALLOC
4225 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, nritems
- 1);
4229 btrfs_release_path(root
, path
);
4231 path
->keep_locks
= 1;
4233 if (!force_blocking
)
4234 path
->leave_spinning
= 1;
4236 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
4237 path
->keep_locks
= 0;
4242 nritems
= btrfs_header_nritems(path
->nodes
[0]);
4244 * by releasing the path above we dropped all our locks. A balance
4245 * could have added more items next to the key that used to be
4246 * at the very end of the block. So, check again here and
4247 * advance the path if there are now more items available.
4249 if (nritems
> 0 && path
->slots
[0] < nritems
- 1) {
4256 while (level
< BTRFS_MAX_LEVEL
) {
4257 if (!path
->nodes
[level
]) {
4262 slot
= path
->slots
[level
] + 1;
4263 c
= path
->nodes
[level
];
4264 if (slot
>= btrfs_header_nritems(c
)) {
4266 if (level
== BTRFS_MAX_LEVEL
) {
4274 btrfs_tree_unlock(next
);
4275 free_extent_buffer(next
);
4279 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
4285 btrfs_release_path(root
, path
);
4289 if (!path
->skip_locking
) {
4290 ret
= btrfs_try_spin_lock(next
);
4292 btrfs_set_path_blocking(path
);
4293 btrfs_tree_lock(next
);
4294 if (!force_blocking
)
4295 btrfs_clear_path_blocking(path
, next
);
4298 btrfs_set_lock_blocking(next
);
4302 path
->slots
[level
] = slot
;
4305 c
= path
->nodes
[level
];
4306 if (path
->locks
[level
])
4307 btrfs_tree_unlock(c
);
4309 free_extent_buffer(c
);
4310 path
->nodes
[level
] = next
;
4311 path
->slots
[level
] = 0;
4312 if (!path
->skip_locking
)
4313 path
->locks
[level
] = 1;
4318 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
4324 btrfs_release_path(root
, path
);
4328 if (!path
->skip_locking
) {
4329 btrfs_assert_tree_locked(path
->nodes
[level
]);
4330 ret
= btrfs_try_spin_lock(next
);
4332 btrfs_set_path_blocking(path
);
4333 btrfs_tree_lock(next
);
4334 if (!force_blocking
)
4335 btrfs_clear_path_blocking(path
, next
);
4338 btrfs_set_lock_blocking(next
);
4343 unlock_up(path
, 0, 1);
4344 path
->leave_spinning
= old_spinning
;
4346 btrfs_set_path_blocking(path
);
4352 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
4353 * searching until it gets past min_objectid or finds an item of 'type'
4355 * returns 0 if something is found, 1 if nothing was found and < 0 on error
4357 int btrfs_previous_item(struct btrfs_root
*root
,
4358 struct btrfs_path
*path
, u64 min_objectid
,
4361 struct btrfs_key found_key
;
4362 struct extent_buffer
*leaf
;
4367 if (path
->slots
[0] == 0) {
4368 btrfs_set_path_blocking(path
);
4369 ret
= btrfs_prev_leaf(root
, path
);
4375 leaf
= path
->nodes
[0];
4376 nritems
= btrfs_header_nritems(leaf
);
4379 if (path
->slots
[0] == nritems
)
4382 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
4383 if (found_key
.objectid
< min_objectid
)
4385 if (found_key
.type
== type
)
4387 if (found_key
.objectid
== min_objectid
&&
4388 found_key
.type
< type
)