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
);
42 struct btrfs_path
*btrfs_alloc_path(void)
44 struct btrfs_path
*path
;
45 path
= kmem_cache_zalloc(btrfs_path_cachep
, GFP_NOFS
);
50 * set all locked nodes in the path to blocking locks. This should
51 * be done before scheduling
53 noinline
void btrfs_set_path_blocking(struct btrfs_path
*p
)
56 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
57 if (!p
->nodes
[i
] || !p
->locks
[i
])
59 btrfs_set_lock_blocking_rw(p
->nodes
[i
], p
->locks
[i
]);
60 if (p
->locks
[i
] == BTRFS_READ_LOCK
)
61 p
->locks
[i
] = BTRFS_READ_LOCK_BLOCKING
;
62 else if (p
->locks
[i
] == BTRFS_WRITE_LOCK
)
63 p
->locks
[i
] = BTRFS_WRITE_LOCK_BLOCKING
;
68 * reset all the locked nodes in the patch to spinning locks.
70 * held is used to keep lockdep happy, when lockdep is enabled
71 * we set held to a blocking lock before we go around and
72 * retake all the spinlocks in the path. You can safely use NULL
75 noinline
void btrfs_clear_path_blocking(struct btrfs_path
*p
,
76 struct extent_buffer
*held
, int held_rw
)
80 #ifdef CONFIG_DEBUG_LOCK_ALLOC
81 /* lockdep really cares that we take all of these spinlocks
82 * in the right order. If any of the locks in the path are not
83 * currently blocking, it is going to complain. So, make really
84 * really sure by forcing the path to blocking before we clear
88 btrfs_set_lock_blocking_rw(held
, held_rw
);
89 if (held_rw
== BTRFS_WRITE_LOCK
)
90 held_rw
= BTRFS_WRITE_LOCK_BLOCKING
;
91 else if (held_rw
== BTRFS_READ_LOCK
)
92 held_rw
= BTRFS_READ_LOCK_BLOCKING
;
94 btrfs_set_path_blocking(p
);
97 for (i
= BTRFS_MAX_LEVEL
- 1; i
>= 0; i
--) {
98 if (p
->nodes
[i
] && p
->locks
[i
]) {
99 btrfs_clear_lock_blocking_rw(p
->nodes
[i
], p
->locks
[i
]);
100 if (p
->locks
[i
] == BTRFS_WRITE_LOCK_BLOCKING
)
101 p
->locks
[i
] = BTRFS_WRITE_LOCK
;
102 else if (p
->locks
[i
] == BTRFS_READ_LOCK_BLOCKING
)
103 p
->locks
[i
] = BTRFS_READ_LOCK
;
107 #ifdef CONFIG_DEBUG_LOCK_ALLOC
109 btrfs_clear_lock_blocking_rw(held
, held_rw
);
113 /* this also releases the path */
114 void btrfs_free_path(struct btrfs_path
*p
)
118 btrfs_release_path(p
);
119 kmem_cache_free(btrfs_path_cachep
, p
);
123 * path release drops references on the extent buffers in the path
124 * and it drops any locks held by this path
126 * It is safe to call this on paths that no locks or extent buffers held.
128 noinline
void btrfs_release_path(struct btrfs_path
*p
)
132 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
137 btrfs_tree_unlock_rw(p
->nodes
[i
], p
->locks
[i
]);
140 free_extent_buffer(p
->nodes
[i
]);
146 * safely gets a reference on the root node of a tree. A lock
147 * is not taken, so a concurrent writer may put a different node
148 * at the root of the tree. See btrfs_lock_root_node for the
151 * The extent buffer returned by this has a reference taken, so
152 * it won't disappear. It may stop being the root of the tree
153 * at any time because there are no locks held.
155 struct extent_buffer
*btrfs_root_node(struct btrfs_root
*root
)
157 struct extent_buffer
*eb
;
161 eb
= rcu_dereference(root
->node
);
164 * RCU really hurts here, we could free up the root node because
165 * it was cow'ed but we may not get the new root node yet so do
166 * the inc_not_zero dance and if it doesn't work then
167 * synchronize_rcu and try again.
169 if (atomic_inc_not_zero(&eb
->refs
)) {
179 /* loop around taking references on and locking the root node of the
180 * tree until you end up with a lock on the root. A locked buffer
181 * is returned, with a reference held.
183 struct extent_buffer
*btrfs_lock_root_node(struct btrfs_root
*root
)
185 struct extent_buffer
*eb
;
188 eb
= btrfs_root_node(root
);
190 if (eb
== root
->node
)
192 btrfs_tree_unlock(eb
);
193 free_extent_buffer(eb
);
198 /* loop around taking references on and locking the root node of the
199 * tree until you end up with a lock on the root. A locked buffer
200 * is returned, with a reference held.
202 struct extent_buffer
*btrfs_read_lock_root_node(struct btrfs_root
*root
)
204 struct extent_buffer
*eb
;
207 eb
= btrfs_root_node(root
);
208 btrfs_tree_read_lock(eb
);
209 if (eb
== root
->node
)
211 btrfs_tree_read_unlock(eb
);
212 free_extent_buffer(eb
);
217 /* cowonly root (everything not a reference counted cow subvolume), just get
218 * put onto a simple dirty list. transaction.c walks this to make sure they
219 * get properly updated on disk.
221 static void add_root_to_dirty_list(struct btrfs_root
*root
)
223 if (root
->track_dirty
&& list_empty(&root
->dirty_list
)) {
224 list_add(&root
->dirty_list
,
225 &root
->fs_info
->dirty_cowonly_roots
);
230 * used by snapshot creation to make a copy of a root for a tree with
231 * a given objectid. The buffer with the new root node is returned in
232 * cow_ret, and this func returns zero on success or a negative error code.
234 int btrfs_copy_root(struct btrfs_trans_handle
*trans
,
235 struct btrfs_root
*root
,
236 struct extent_buffer
*buf
,
237 struct extent_buffer
**cow_ret
, u64 new_root_objectid
)
239 struct extent_buffer
*cow
;
242 struct btrfs_disk_key disk_key
;
244 WARN_ON(root
->ref_cows
&& trans
->transid
!=
245 root
->fs_info
->running_transaction
->transid
);
246 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
248 level
= btrfs_header_level(buf
);
250 btrfs_item_key(buf
, &disk_key
, 0);
252 btrfs_node_key(buf
, &disk_key
, 0);
254 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, 0,
255 new_root_objectid
, &disk_key
, level
,
260 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
261 btrfs_set_header_bytenr(cow
, cow
->start
);
262 btrfs_set_header_generation(cow
, trans
->transid
);
263 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
264 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
265 BTRFS_HEADER_FLAG_RELOC
);
266 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
267 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
269 btrfs_set_header_owner(cow
, new_root_objectid
);
271 write_extent_buffer(cow
, root
->fs_info
->fsid
,
272 (unsigned long)btrfs_header_fsid(cow
),
275 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
276 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
277 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
279 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
284 btrfs_mark_buffer_dirty(cow
);
290 * check if the tree block can be shared by multiple trees
292 int btrfs_block_can_be_shared(struct btrfs_root
*root
,
293 struct extent_buffer
*buf
)
296 * Tree blocks not in refernece counted trees and tree roots
297 * are never shared. If a block was allocated after the last
298 * snapshot and the block was not allocated by tree relocation,
299 * we know the block is not shared.
301 if (root
->ref_cows
&&
302 buf
!= root
->node
&& buf
!= root
->commit_root
&&
303 (btrfs_header_generation(buf
) <=
304 btrfs_root_last_snapshot(&root
->root_item
) ||
305 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)))
307 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
308 if (root
->ref_cows
&&
309 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
315 static noinline
int update_ref_for_cow(struct btrfs_trans_handle
*trans
,
316 struct btrfs_root
*root
,
317 struct extent_buffer
*buf
,
318 struct extent_buffer
*cow
,
328 * Backrefs update rules:
330 * Always use full backrefs for extent pointers in tree block
331 * allocated by tree relocation.
333 * If a shared tree block is no longer referenced by its owner
334 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
335 * use full backrefs for extent pointers in tree block.
337 * If a tree block is been relocating
338 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
339 * use full backrefs for extent pointers in tree block.
340 * The reason for this is some operations (such as drop tree)
341 * are only allowed for blocks use full backrefs.
344 if (btrfs_block_can_be_shared(root
, buf
)) {
345 ret
= btrfs_lookup_extent_info(trans
, root
, buf
->start
,
346 buf
->len
, &refs
, &flags
);
351 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
352 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
353 flags
= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
358 owner
= btrfs_header_owner(buf
);
359 BUG_ON(owner
== BTRFS_TREE_RELOC_OBJECTID
&&
360 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
));
363 if ((owner
== root
->root_key
.objectid
||
364 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) &&
365 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)) {
366 ret
= btrfs_inc_ref(trans
, root
, buf
, 1, 1);
369 if (root
->root_key
.objectid
==
370 BTRFS_TREE_RELOC_OBJECTID
) {
371 ret
= btrfs_dec_ref(trans
, root
, buf
, 0, 1);
373 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
376 new_flags
|= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
379 if (root
->root_key
.objectid
==
380 BTRFS_TREE_RELOC_OBJECTID
)
381 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
383 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
386 if (new_flags
!= 0) {
387 ret
= btrfs_set_disk_extent_flags(trans
, root
,
394 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
) {
395 if (root
->root_key
.objectid
==
396 BTRFS_TREE_RELOC_OBJECTID
)
397 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
399 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
401 ret
= btrfs_dec_ref(trans
, root
, buf
, 1, 1);
404 clean_tree_block(trans
, root
, buf
);
411 * does the dirty work in cow of a single block. The parent block (if
412 * supplied) is updated to point to the new cow copy. The new buffer is marked
413 * dirty and returned locked. If you modify the block it needs to be marked
416 * search_start -- an allocation hint for the new block
418 * empty_size -- a hint that you plan on doing more cow. This is the size in
419 * bytes the allocator should try to find free next to the block it returns.
420 * This is just a hint and may be ignored by the allocator.
422 static noinline
int __btrfs_cow_block(struct btrfs_trans_handle
*trans
,
423 struct btrfs_root
*root
,
424 struct extent_buffer
*buf
,
425 struct extent_buffer
*parent
, int parent_slot
,
426 struct extent_buffer
**cow_ret
,
427 u64 search_start
, u64 empty_size
)
429 struct btrfs_disk_key disk_key
;
430 struct extent_buffer
*cow
;
439 btrfs_assert_tree_locked(buf
);
441 WARN_ON(root
->ref_cows
&& trans
->transid
!=
442 root
->fs_info
->running_transaction
->transid
);
443 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
445 level
= btrfs_header_level(buf
);
448 btrfs_item_key(buf
, &disk_key
, 0);
450 btrfs_node_key(buf
, &disk_key
, 0);
452 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
454 parent_start
= parent
->start
;
460 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, parent_start
,
461 root
->root_key
.objectid
, &disk_key
,
462 level
, search_start
, empty_size
, 1);
466 /* cow is set to blocking by btrfs_init_new_buffer */
468 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
469 btrfs_set_header_bytenr(cow
, cow
->start
);
470 btrfs_set_header_generation(cow
, trans
->transid
);
471 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
472 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
473 BTRFS_HEADER_FLAG_RELOC
);
474 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
475 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
477 btrfs_set_header_owner(cow
, root
->root_key
.objectid
);
479 write_extent_buffer(cow
, root
->fs_info
->fsid
,
480 (unsigned long)btrfs_header_fsid(cow
),
483 update_ref_for_cow(trans
, root
, buf
, cow
, &last_ref
);
486 btrfs_reloc_cow_block(trans
, root
, buf
, cow
);
488 if (buf
== root
->node
) {
489 WARN_ON(parent
&& parent
!= buf
);
490 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
491 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
492 parent_start
= buf
->start
;
496 extent_buffer_get(cow
);
497 rcu_assign_pointer(root
->node
, cow
);
499 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
501 free_extent_buffer(buf
);
502 add_root_to_dirty_list(root
);
504 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
505 parent_start
= parent
->start
;
509 WARN_ON(trans
->transid
!= btrfs_header_generation(parent
));
510 btrfs_set_node_blockptr(parent
, parent_slot
,
512 btrfs_set_node_ptr_generation(parent
, parent_slot
,
514 btrfs_mark_buffer_dirty(parent
);
515 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
519 btrfs_tree_unlock(buf
);
520 free_extent_buffer_stale(buf
);
521 btrfs_mark_buffer_dirty(cow
);
526 static inline int should_cow_block(struct btrfs_trans_handle
*trans
,
527 struct btrfs_root
*root
,
528 struct extent_buffer
*buf
)
530 /* ensure we can see the force_cow */
534 * We do not need to cow a block if
535 * 1) this block is not created or changed in this transaction;
536 * 2) this block does not belong to TREE_RELOC tree;
537 * 3) the root is not forced COW.
539 * What is forced COW:
540 * when we create snapshot during commiting the transaction,
541 * after we've finished coping src root, we must COW the shared
542 * block to ensure the metadata consistency.
544 if (btrfs_header_generation(buf
) == trans
->transid
&&
545 !btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_WRITTEN
) &&
546 !(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
&&
547 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)) &&
554 * cows a single block, see __btrfs_cow_block for the real work.
555 * This version of it has extra checks so that a block isn't cow'd more than
556 * once per transaction, as long as it hasn't been written yet
558 noinline
int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
559 struct btrfs_root
*root
, struct extent_buffer
*buf
,
560 struct extent_buffer
*parent
, int parent_slot
,
561 struct extent_buffer
**cow_ret
)
566 if (trans
->transaction
!= root
->fs_info
->running_transaction
) {
567 printk(KERN_CRIT
"trans %llu running %llu\n",
568 (unsigned long long)trans
->transid
,
570 root
->fs_info
->running_transaction
->transid
);
573 if (trans
->transid
!= root
->fs_info
->generation
) {
574 printk(KERN_CRIT
"trans %llu running %llu\n",
575 (unsigned long long)trans
->transid
,
576 (unsigned long long)root
->fs_info
->generation
);
580 if (!should_cow_block(trans
, root
, buf
)) {
585 search_start
= buf
->start
& ~((u64
)(1024 * 1024 * 1024) - 1);
588 btrfs_set_lock_blocking(parent
);
589 btrfs_set_lock_blocking(buf
);
591 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
592 parent_slot
, cow_ret
, search_start
, 0);
594 trace_btrfs_cow_block(root
, buf
, *cow_ret
);
600 * helper function for defrag to decide if two blocks pointed to by a
601 * node are actually close by
603 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
605 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
607 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
613 * compare two keys in a memcmp fashion
615 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
619 btrfs_disk_key_to_cpu(&k1
, disk
);
621 return btrfs_comp_cpu_keys(&k1
, k2
);
625 * same as comp_keys only with two btrfs_key's
627 int btrfs_comp_cpu_keys(struct btrfs_key
*k1
, struct btrfs_key
*k2
)
629 if (k1
->objectid
> k2
->objectid
)
631 if (k1
->objectid
< k2
->objectid
)
633 if (k1
->type
> k2
->type
)
635 if (k1
->type
< k2
->type
)
637 if (k1
->offset
> k2
->offset
)
639 if (k1
->offset
< k2
->offset
)
645 * this is used by the defrag code to go through all the
646 * leaves pointed to by a node and reallocate them so that
647 * disk order is close to key order
649 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
650 struct btrfs_root
*root
, struct extent_buffer
*parent
,
651 int start_slot
, int cache_only
, u64
*last_ret
,
652 struct btrfs_key
*progress
)
654 struct extent_buffer
*cur
;
657 u64 search_start
= *last_ret
;
667 int progress_passed
= 0;
668 struct btrfs_disk_key disk_key
;
670 parent_level
= btrfs_header_level(parent
);
671 if (cache_only
&& parent_level
!= 1)
674 if (trans
->transaction
!= root
->fs_info
->running_transaction
)
676 if (trans
->transid
!= root
->fs_info
->generation
)
679 parent_nritems
= btrfs_header_nritems(parent
);
680 blocksize
= btrfs_level_size(root
, parent_level
- 1);
681 end_slot
= parent_nritems
;
683 if (parent_nritems
== 1)
686 btrfs_set_lock_blocking(parent
);
688 for (i
= start_slot
; i
< end_slot
; i
++) {
691 btrfs_node_key(parent
, &disk_key
, i
);
692 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
696 blocknr
= btrfs_node_blockptr(parent
, i
);
697 gen
= btrfs_node_ptr_generation(parent
, i
);
699 last_block
= blocknr
;
702 other
= btrfs_node_blockptr(parent
, i
- 1);
703 close
= close_blocks(blocknr
, other
, blocksize
);
705 if (!close
&& i
< end_slot
- 2) {
706 other
= btrfs_node_blockptr(parent
, i
+ 1);
707 close
= close_blocks(blocknr
, other
, blocksize
);
710 last_block
= blocknr
;
714 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
716 uptodate
= btrfs_buffer_uptodate(cur
, gen
);
719 if (!cur
|| !uptodate
) {
721 free_extent_buffer(cur
);
725 cur
= read_tree_block(root
, blocknr
,
729 } else if (!uptodate
) {
730 btrfs_read_buffer(cur
, gen
);
733 if (search_start
== 0)
734 search_start
= last_block
;
736 btrfs_tree_lock(cur
);
737 btrfs_set_lock_blocking(cur
);
738 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
741 (end_slot
- i
) * blocksize
));
743 btrfs_tree_unlock(cur
);
744 free_extent_buffer(cur
);
747 search_start
= cur
->start
;
748 last_block
= cur
->start
;
749 *last_ret
= search_start
;
750 btrfs_tree_unlock(cur
);
751 free_extent_buffer(cur
);
757 * The leaf data grows from end-to-front in the node.
758 * this returns the address of the start of the last item,
759 * which is the stop of the leaf data stack
761 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
762 struct extent_buffer
*leaf
)
764 u32 nr
= btrfs_header_nritems(leaf
);
766 return BTRFS_LEAF_DATA_SIZE(root
);
767 return btrfs_item_offset_nr(leaf
, nr
- 1);
772 * search for key in the extent_buffer. The items start at offset p,
773 * and they are item_size apart. There are 'max' items in p.
775 * the slot in the array is returned via slot, and it points to
776 * the place where you would insert key if it is not found in
779 * slot may point to max if the key is bigger than all of the keys
781 static noinline
int generic_bin_search(struct extent_buffer
*eb
,
783 int item_size
, struct btrfs_key
*key
,
790 struct btrfs_disk_key
*tmp
= NULL
;
791 struct btrfs_disk_key unaligned
;
792 unsigned long offset
;
794 unsigned long map_start
= 0;
795 unsigned long map_len
= 0;
799 mid
= (low
+ high
) / 2;
800 offset
= p
+ mid
* item_size
;
802 if (!kaddr
|| offset
< map_start
||
803 (offset
+ sizeof(struct btrfs_disk_key
)) >
804 map_start
+ map_len
) {
806 err
= map_private_extent_buffer(eb
, offset
,
807 sizeof(struct btrfs_disk_key
),
808 &kaddr
, &map_start
, &map_len
);
811 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
814 read_extent_buffer(eb
, &unaligned
,
815 offset
, sizeof(unaligned
));
820 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
823 ret
= comp_keys(tmp
, key
);
839 * simple bin_search frontend that does the right thing for
842 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
843 int level
, int *slot
)
846 return generic_bin_search(eb
,
847 offsetof(struct btrfs_leaf
, items
),
848 sizeof(struct btrfs_item
),
849 key
, btrfs_header_nritems(eb
),
852 return generic_bin_search(eb
,
853 offsetof(struct btrfs_node
, ptrs
),
854 sizeof(struct btrfs_key_ptr
),
855 key
, btrfs_header_nritems(eb
),
861 int btrfs_bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
862 int level
, int *slot
)
864 return bin_search(eb
, key
, level
, slot
);
867 static void root_add_used(struct btrfs_root
*root
, u32 size
)
869 spin_lock(&root
->accounting_lock
);
870 btrfs_set_root_used(&root
->root_item
,
871 btrfs_root_used(&root
->root_item
) + size
);
872 spin_unlock(&root
->accounting_lock
);
875 static void root_sub_used(struct btrfs_root
*root
, u32 size
)
877 spin_lock(&root
->accounting_lock
);
878 btrfs_set_root_used(&root
->root_item
,
879 btrfs_root_used(&root
->root_item
) - size
);
880 spin_unlock(&root
->accounting_lock
);
883 /* given a node and slot number, this reads the blocks it points to. The
884 * extent buffer is returned with a reference taken (but unlocked).
885 * NULL is returned on error.
887 static noinline
struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
888 struct extent_buffer
*parent
, int slot
)
890 int level
= btrfs_header_level(parent
);
893 if (slot
>= btrfs_header_nritems(parent
))
898 return read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
899 btrfs_level_size(root
, level
- 1),
900 btrfs_node_ptr_generation(parent
, slot
));
904 * node level balancing, used to make sure nodes are in proper order for
905 * item deletion. We balance from the top down, so we have to make sure
906 * that a deletion won't leave an node completely empty later on.
908 static noinline
int balance_level(struct btrfs_trans_handle
*trans
,
909 struct btrfs_root
*root
,
910 struct btrfs_path
*path
, int level
)
912 struct extent_buffer
*right
= NULL
;
913 struct extent_buffer
*mid
;
914 struct extent_buffer
*left
= NULL
;
915 struct extent_buffer
*parent
= NULL
;
919 int orig_slot
= path
->slots
[level
];
925 mid
= path
->nodes
[level
];
927 WARN_ON(path
->locks
[level
] != BTRFS_WRITE_LOCK
&&
928 path
->locks
[level
] != BTRFS_WRITE_LOCK_BLOCKING
);
929 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
931 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
933 if (level
< BTRFS_MAX_LEVEL
- 1) {
934 parent
= path
->nodes
[level
+ 1];
935 pslot
= path
->slots
[level
+ 1];
939 * deal with the case where there is only one pointer in the root
940 * by promoting the node below to a root
943 struct extent_buffer
*child
;
945 if (btrfs_header_nritems(mid
) != 1)
948 /* promote the child to a root */
949 child
= read_node_slot(root
, mid
, 0);
951 btrfs_tree_lock(child
);
952 btrfs_set_lock_blocking(child
);
953 ret
= btrfs_cow_block(trans
, root
, child
, mid
, 0, &child
);
955 btrfs_tree_unlock(child
);
956 free_extent_buffer(child
);
960 rcu_assign_pointer(root
->node
, child
);
962 add_root_to_dirty_list(root
);
963 btrfs_tree_unlock(child
);
965 path
->locks
[level
] = 0;
966 path
->nodes
[level
] = NULL
;
967 clean_tree_block(trans
, root
, mid
);
968 btrfs_tree_unlock(mid
);
969 /* once for the path */
970 free_extent_buffer(mid
);
972 root_sub_used(root
, mid
->len
);
973 btrfs_free_tree_block(trans
, root
, mid
, 0, 1, 0);
974 /* once for the root ptr */
975 free_extent_buffer_stale(mid
);
978 if (btrfs_header_nritems(mid
) >
979 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
982 btrfs_header_nritems(mid
);
984 left
= read_node_slot(root
, parent
, pslot
- 1);
986 btrfs_tree_lock(left
);
987 btrfs_set_lock_blocking(left
);
988 wret
= btrfs_cow_block(trans
, root
, left
,
989 parent
, pslot
- 1, &left
);
995 right
= read_node_slot(root
, parent
, pslot
+ 1);
997 btrfs_tree_lock(right
);
998 btrfs_set_lock_blocking(right
);
999 wret
= btrfs_cow_block(trans
, root
, right
,
1000 parent
, pslot
+ 1, &right
);
1007 /* first, try to make some room in the middle buffer */
1009 orig_slot
+= btrfs_header_nritems(left
);
1010 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1013 btrfs_header_nritems(mid
);
1017 * then try to empty the right most buffer into the middle
1020 wret
= push_node_left(trans
, root
, mid
, right
, 1);
1021 if (wret
< 0 && wret
!= -ENOSPC
)
1023 if (btrfs_header_nritems(right
) == 0) {
1024 clean_tree_block(trans
, root
, right
);
1025 btrfs_tree_unlock(right
);
1026 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
+
1030 root_sub_used(root
, right
->len
);
1031 btrfs_free_tree_block(trans
, root
, right
, 0, 1, 0);
1032 free_extent_buffer_stale(right
);
1035 struct btrfs_disk_key right_key
;
1036 btrfs_node_key(right
, &right_key
, 0);
1037 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
1038 btrfs_mark_buffer_dirty(parent
);
1041 if (btrfs_header_nritems(mid
) == 1) {
1043 * we're not allowed to leave a node with one item in the
1044 * tree during a delete. A deletion from lower in the tree
1045 * could try to delete the only pointer in this node.
1046 * So, pull some keys from the left.
1047 * There has to be a left pointer at this point because
1048 * otherwise we would have pulled some pointers from the
1052 wret
= balance_node_right(trans
, root
, mid
, left
);
1058 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1064 if (btrfs_header_nritems(mid
) == 0) {
1065 clean_tree_block(trans
, root
, mid
);
1066 btrfs_tree_unlock(mid
);
1067 wret
= del_ptr(trans
, root
, path
, level
+ 1, pslot
);
1070 root_sub_used(root
, mid
->len
);
1071 btrfs_free_tree_block(trans
, root
, mid
, 0, 1, 0);
1072 free_extent_buffer_stale(mid
);
1075 /* update the parent key to reflect our changes */
1076 struct btrfs_disk_key mid_key
;
1077 btrfs_node_key(mid
, &mid_key
, 0);
1078 btrfs_set_node_key(parent
, &mid_key
, pslot
);
1079 btrfs_mark_buffer_dirty(parent
);
1082 /* update the path */
1084 if (btrfs_header_nritems(left
) > orig_slot
) {
1085 extent_buffer_get(left
);
1086 /* left was locked after cow */
1087 path
->nodes
[level
] = left
;
1088 path
->slots
[level
+ 1] -= 1;
1089 path
->slots
[level
] = orig_slot
;
1091 btrfs_tree_unlock(mid
);
1092 free_extent_buffer(mid
);
1095 orig_slot
-= btrfs_header_nritems(left
);
1096 path
->slots
[level
] = orig_slot
;
1099 /* double check we haven't messed things up */
1101 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
1105 btrfs_tree_unlock(right
);
1106 free_extent_buffer(right
);
1109 if (path
->nodes
[level
] != left
)
1110 btrfs_tree_unlock(left
);
1111 free_extent_buffer(left
);
1116 /* Node balancing for insertion. Here we only split or push nodes around
1117 * when they are completely full. This is also done top down, so we
1118 * have to be pessimistic.
1120 static noinline
int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
1121 struct btrfs_root
*root
,
1122 struct btrfs_path
*path
, int level
)
1124 struct extent_buffer
*right
= NULL
;
1125 struct extent_buffer
*mid
;
1126 struct extent_buffer
*left
= NULL
;
1127 struct extent_buffer
*parent
= NULL
;
1131 int orig_slot
= path
->slots
[level
];
1136 mid
= path
->nodes
[level
];
1137 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1139 if (level
< BTRFS_MAX_LEVEL
- 1) {
1140 parent
= path
->nodes
[level
+ 1];
1141 pslot
= path
->slots
[level
+ 1];
1147 left
= read_node_slot(root
, parent
, pslot
- 1);
1149 /* first, try to make some room in the middle buffer */
1153 btrfs_tree_lock(left
);
1154 btrfs_set_lock_blocking(left
);
1156 left_nr
= btrfs_header_nritems(left
);
1157 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1160 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
1165 wret
= push_node_left(trans
, root
,
1172 struct btrfs_disk_key disk_key
;
1173 orig_slot
+= left_nr
;
1174 btrfs_node_key(mid
, &disk_key
, 0);
1175 btrfs_set_node_key(parent
, &disk_key
, pslot
);
1176 btrfs_mark_buffer_dirty(parent
);
1177 if (btrfs_header_nritems(left
) > orig_slot
) {
1178 path
->nodes
[level
] = left
;
1179 path
->slots
[level
+ 1] -= 1;
1180 path
->slots
[level
] = orig_slot
;
1181 btrfs_tree_unlock(mid
);
1182 free_extent_buffer(mid
);
1185 btrfs_header_nritems(left
);
1186 path
->slots
[level
] = orig_slot
;
1187 btrfs_tree_unlock(left
);
1188 free_extent_buffer(left
);
1192 btrfs_tree_unlock(left
);
1193 free_extent_buffer(left
);
1195 right
= read_node_slot(root
, parent
, pslot
+ 1);
1198 * then try to empty the right most buffer into the middle
1203 btrfs_tree_lock(right
);
1204 btrfs_set_lock_blocking(right
);
1206 right_nr
= btrfs_header_nritems(right
);
1207 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
1210 ret
= btrfs_cow_block(trans
, root
, right
,
1216 wret
= balance_node_right(trans
, root
,
1223 struct btrfs_disk_key disk_key
;
1225 btrfs_node_key(right
, &disk_key
, 0);
1226 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
1227 btrfs_mark_buffer_dirty(parent
);
1229 if (btrfs_header_nritems(mid
) <= orig_slot
) {
1230 path
->nodes
[level
] = right
;
1231 path
->slots
[level
+ 1] += 1;
1232 path
->slots
[level
] = orig_slot
-
1233 btrfs_header_nritems(mid
);
1234 btrfs_tree_unlock(mid
);
1235 free_extent_buffer(mid
);
1237 btrfs_tree_unlock(right
);
1238 free_extent_buffer(right
);
1242 btrfs_tree_unlock(right
);
1243 free_extent_buffer(right
);
1249 * readahead one full node of leaves, finding things that are close
1250 * to the block in 'slot', and triggering ra on them.
1252 static void reada_for_search(struct btrfs_root
*root
,
1253 struct btrfs_path
*path
,
1254 int level
, int slot
, u64 objectid
)
1256 struct extent_buffer
*node
;
1257 struct btrfs_disk_key disk_key
;
1263 int direction
= path
->reada
;
1264 struct extent_buffer
*eb
;
1272 if (!path
->nodes
[level
])
1275 node
= path
->nodes
[level
];
1277 search
= btrfs_node_blockptr(node
, slot
);
1278 blocksize
= btrfs_level_size(root
, level
- 1);
1279 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
1281 free_extent_buffer(eb
);
1287 nritems
= btrfs_header_nritems(node
);
1291 if (direction
< 0) {
1295 } else if (direction
> 0) {
1300 if (path
->reada
< 0 && objectid
) {
1301 btrfs_node_key(node
, &disk_key
, nr
);
1302 if (btrfs_disk_key_objectid(&disk_key
) != objectid
)
1305 search
= btrfs_node_blockptr(node
, nr
);
1306 if ((search
<= target
&& target
- search
<= 65536) ||
1307 (search
> target
&& search
- target
<= 65536)) {
1308 gen
= btrfs_node_ptr_generation(node
, nr
);
1309 readahead_tree_block(root
, search
, blocksize
, gen
);
1313 if ((nread
> 65536 || nscan
> 32))
1319 * returns -EAGAIN if it had to drop the path, or zero if everything was in
1322 static noinline
int reada_for_balance(struct btrfs_root
*root
,
1323 struct btrfs_path
*path
, int level
)
1327 struct extent_buffer
*parent
;
1328 struct extent_buffer
*eb
;
1335 parent
= path
->nodes
[level
+ 1];
1339 nritems
= btrfs_header_nritems(parent
);
1340 slot
= path
->slots
[level
+ 1];
1341 blocksize
= btrfs_level_size(root
, level
);
1344 block1
= btrfs_node_blockptr(parent
, slot
- 1);
1345 gen
= btrfs_node_ptr_generation(parent
, slot
- 1);
1346 eb
= btrfs_find_tree_block(root
, block1
, blocksize
);
1347 if (eb
&& btrfs_buffer_uptodate(eb
, gen
))
1349 free_extent_buffer(eb
);
1351 if (slot
+ 1 < nritems
) {
1352 block2
= btrfs_node_blockptr(parent
, slot
+ 1);
1353 gen
= btrfs_node_ptr_generation(parent
, slot
+ 1);
1354 eb
= btrfs_find_tree_block(root
, block2
, blocksize
);
1355 if (eb
&& btrfs_buffer_uptodate(eb
, gen
))
1357 free_extent_buffer(eb
);
1359 if (block1
|| block2
) {
1362 /* release the whole path */
1363 btrfs_release_path(path
);
1365 /* read the blocks */
1367 readahead_tree_block(root
, block1
, blocksize
, 0);
1369 readahead_tree_block(root
, block2
, blocksize
, 0);
1372 eb
= read_tree_block(root
, block1
, blocksize
, 0);
1373 free_extent_buffer(eb
);
1376 eb
= read_tree_block(root
, block2
, blocksize
, 0);
1377 free_extent_buffer(eb
);
1385 * when we walk down the tree, it is usually safe to unlock the higher layers
1386 * in the tree. The exceptions are when our path goes through slot 0, because
1387 * operations on the tree might require changing key pointers higher up in the
1390 * callers might also have set path->keep_locks, which tells this code to keep
1391 * the lock if the path points to the last slot in the block. This is part of
1392 * walking through the tree, and selecting the next slot in the higher block.
1394 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
1395 * if lowest_unlock is 1, level 0 won't be unlocked
1397 static noinline
void unlock_up(struct btrfs_path
*path
, int level
,
1401 int skip_level
= level
;
1403 struct extent_buffer
*t
;
1405 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1406 if (!path
->nodes
[i
])
1408 if (!path
->locks
[i
])
1410 if (!no_skips
&& path
->slots
[i
] == 0) {
1414 if (!no_skips
&& path
->keep_locks
) {
1417 nritems
= btrfs_header_nritems(t
);
1418 if (nritems
< 1 || path
->slots
[i
] >= nritems
- 1) {
1423 if (skip_level
< i
&& i
>= lowest_unlock
)
1427 if (i
>= lowest_unlock
&& i
> skip_level
&& path
->locks
[i
]) {
1428 btrfs_tree_unlock_rw(t
, path
->locks
[i
]);
1435 * This releases any locks held in the path starting at level and
1436 * going all the way up to the root.
1438 * btrfs_search_slot will keep the lock held on higher nodes in a few
1439 * corner cases, such as COW of the block at slot zero in the node. This
1440 * ignores those rules, and it should only be called when there are no
1441 * more updates to be done higher up in the tree.
1443 noinline
void btrfs_unlock_up_safe(struct btrfs_path
*path
, int level
)
1447 if (path
->keep_locks
)
1450 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1451 if (!path
->nodes
[i
])
1453 if (!path
->locks
[i
])
1455 btrfs_tree_unlock_rw(path
->nodes
[i
], path
->locks
[i
]);
1461 * helper function for btrfs_search_slot. The goal is to find a block
1462 * in cache without setting the path to blocking. If we find the block
1463 * we return zero and the path is unchanged.
1465 * If we can't find the block, we set the path blocking and do some
1466 * reada. -EAGAIN is returned and the search must be repeated.
1469 read_block_for_search(struct btrfs_trans_handle
*trans
,
1470 struct btrfs_root
*root
, struct btrfs_path
*p
,
1471 struct extent_buffer
**eb_ret
, int level
, int slot
,
1472 struct btrfs_key
*key
)
1477 struct extent_buffer
*b
= *eb_ret
;
1478 struct extent_buffer
*tmp
;
1481 blocknr
= btrfs_node_blockptr(b
, slot
);
1482 gen
= btrfs_node_ptr_generation(b
, slot
);
1483 blocksize
= btrfs_level_size(root
, level
- 1);
1485 tmp
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
1487 if (btrfs_buffer_uptodate(tmp
, 0)) {
1488 if (btrfs_buffer_uptodate(tmp
, gen
)) {
1490 * we found an up to date block without
1497 /* the pages were up to date, but we failed
1498 * the generation number check. Do a full
1499 * read for the generation number that is correct.
1500 * We must do this without dropping locks so
1501 * we can trust our generation number
1503 free_extent_buffer(tmp
);
1504 btrfs_set_path_blocking(p
);
1506 tmp
= read_tree_block(root
, blocknr
, blocksize
, gen
);
1507 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
1511 free_extent_buffer(tmp
);
1512 btrfs_release_path(p
);
1518 * reduce lock contention at high levels
1519 * of the btree by dropping locks before
1520 * we read. Don't release the lock on the current
1521 * level because we need to walk this node to figure
1522 * out which blocks to read.
1524 btrfs_unlock_up_safe(p
, level
+ 1);
1525 btrfs_set_path_blocking(p
);
1527 free_extent_buffer(tmp
);
1529 reada_for_search(root
, p
, level
, slot
, key
->objectid
);
1531 btrfs_release_path(p
);
1534 tmp
= read_tree_block(root
, blocknr
, blocksize
, 0);
1537 * If the read above didn't mark this buffer up to date,
1538 * it will never end up being up to date. Set ret to EIO now
1539 * and give up so that our caller doesn't loop forever
1542 if (!btrfs_buffer_uptodate(tmp
, 0))
1544 free_extent_buffer(tmp
);
1550 * helper function for btrfs_search_slot. This does all of the checks
1551 * for node-level blocks and does any balancing required based on
1554 * If no extra work was required, zero is returned. If we had to
1555 * drop the path, -EAGAIN is returned and btrfs_search_slot must
1559 setup_nodes_for_search(struct btrfs_trans_handle
*trans
,
1560 struct btrfs_root
*root
, struct btrfs_path
*p
,
1561 struct extent_buffer
*b
, int level
, int ins_len
,
1562 int *write_lock_level
)
1565 if ((p
->search_for_split
|| ins_len
> 0) && btrfs_header_nritems(b
) >=
1566 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3) {
1569 if (*write_lock_level
< level
+ 1) {
1570 *write_lock_level
= level
+ 1;
1571 btrfs_release_path(p
);
1575 sret
= reada_for_balance(root
, p
, level
);
1579 btrfs_set_path_blocking(p
);
1580 sret
= split_node(trans
, root
, p
, level
);
1581 btrfs_clear_path_blocking(p
, NULL
, 0);
1588 b
= p
->nodes
[level
];
1589 } else if (ins_len
< 0 && btrfs_header_nritems(b
) <
1590 BTRFS_NODEPTRS_PER_BLOCK(root
) / 2) {
1593 if (*write_lock_level
< level
+ 1) {
1594 *write_lock_level
= level
+ 1;
1595 btrfs_release_path(p
);
1599 sret
= reada_for_balance(root
, p
, level
);
1603 btrfs_set_path_blocking(p
);
1604 sret
= balance_level(trans
, root
, p
, level
);
1605 btrfs_clear_path_blocking(p
, NULL
, 0);
1611 b
= p
->nodes
[level
];
1613 btrfs_release_path(p
);
1616 BUG_ON(btrfs_header_nritems(b
) == 1);
1627 * look for key in the tree. path is filled in with nodes along the way
1628 * if key is found, we return zero and you can find the item in the leaf
1629 * level of the path (level 0)
1631 * If the key isn't found, the path points to the slot where it should
1632 * be inserted, and 1 is returned. If there are other errors during the
1633 * search a negative error number is returned.
1635 * if ins_len > 0, nodes and leaves will be split as we walk down the
1636 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
1639 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
1640 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
1643 struct extent_buffer
*b
;
1648 int lowest_unlock
= 1;
1650 /* everything at write_lock_level or lower must be write locked */
1651 int write_lock_level
= 0;
1652 u8 lowest_level
= 0;
1654 lowest_level
= p
->lowest_level
;
1655 WARN_ON(lowest_level
&& ins_len
> 0);
1656 WARN_ON(p
->nodes
[0] != NULL
);
1661 /* when we are removing items, we might have to go up to level
1662 * two as we update tree pointers Make sure we keep write
1663 * for those levels as well
1665 write_lock_level
= 2;
1666 } else if (ins_len
> 0) {
1668 * for inserting items, make sure we have a write lock on
1669 * level 1 so we can update keys
1671 write_lock_level
= 1;
1675 write_lock_level
= -1;
1677 if (cow
&& (p
->keep_locks
|| p
->lowest_level
))
1678 write_lock_level
= BTRFS_MAX_LEVEL
;
1682 * we try very hard to do read locks on the root
1684 root_lock
= BTRFS_READ_LOCK
;
1686 if (p
->search_commit_root
) {
1688 * the commit roots are read only
1689 * so we always do read locks
1691 b
= root
->commit_root
;
1692 extent_buffer_get(b
);
1693 level
= btrfs_header_level(b
);
1694 if (!p
->skip_locking
)
1695 btrfs_tree_read_lock(b
);
1697 if (p
->skip_locking
) {
1698 b
= btrfs_root_node(root
);
1699 level
= btrfs_header_level(b
);
1701 /* we don't know the level of the root node
1702 * until we actually have it read locked
1704 b
= btrfs_read_lock_root_node(root
);
1705 level
= btrfs_header_level(b
);
1706 if (level
<= write_lock_level
) {
1707 /* whoops, must trade for write lock */
1708 btrfs_tree_read_unlock(b
);
1709 free_extent_buffer(b
);
1710 b
= btrfs_lock_root_node(root
);
1711 root_lock
= BTRFS_WRITE_LOCK
;
1713 /* the level might have changed, check again */
1714 level
= btrfs_header_level(b
);
1718 p
->nodes
[level
] = b
;
1719 if (!p
->skip_locking
)
1720 p
->locks
[level
] = root_lock
;
1723 level
= btrfs_header_level(b
);
1726 * setup the path here so we can release it under lock
1727 * contention with the cow code
1731 * if we don't really need to cow this block
1732 * then we don't want to set the path blocking,
1733 * so we test it here
1735 if (!should_cow_block(trans
, root
, b
))
1738 btrfs_set_path_blocking(p
);
1741 * must have write locks on this node and the
1744 if (level
+ 1 > write_lock_level
) {
1745 write_lock_level
= level
+ 1;
1746 btrfs_release_path(p
);
1750 err
= btrfs_cow_block(trans
, root
, b
,
1751 p
->nodes
[level
+ 1],
1752 p
->slots
[level
+ 1], &b
);
1759 BUG_ON(!cow
&& ins_len
);
1761 p
->nodes
[level
] = b
;
1762 btrfs_clear_path_blocking(p
, NULL
, 0);
1765 * we have a lock on b and as long as we aren't changing
1766 * the tree, there is no way to for the items in b to change.
1767 * It is safe to drop the lock on our parent before we
1768 * go through the expensive btree search on b.
1770 * If cow is true, then we might be changing slot zero,
1771 * which may require changing the parent. So, we can't
1772 * drop the lock until after we know which slot we're
1776 btrfs_unlock_up_safe(p
, level
+ 1);
1778 ret
= bin_search(b
, key
, level
, &slot
);
1782 if (ret
&& slot
> 0) {
1786 p
->slots
[level
] = slot
;
1787 err
= setup_nodes_for_search(trans
, root
, p
, b
, level
,
1788 ins_len
, &write_lock_level
);
1795 b
= p
->nodes
[level
];
1796 slot
= p
->slots
[level
];
1799 * slot 0 is special, if we change the key
1800 * we have to update the parent pointer
1801 * which means we must have a write lock
1804 if (slot
== 0 && cow
&&
1805 write_lock_level
< level
+ 1) {
1806 write_lock_level
= level
+ 1;
1807 btrfs_release_path(p
);
1811 unlock_up(p
, level
, lowest_unlock
);
1813 if (level
== lowest_level
) {
1819 err
= read_block_for_search(trans
, root
, p
,
1820 &b
, level
, slot
, key
);
1828 if (!p
->skip_locking
) {
1829 level
= btrfs_header_level(b
);
1830 if (level
<= write_lock_level
) {
1831 err
= btrfs_try_tree_write_lock(b
);
1833 btrfs_set_path_blocking(p
);
1835 btrfs_clear_path_blocking(p
, b
,
1838 p
->locks
[level
] = BTRFS_WRITE_LOCK
;
1840 err
= btrfs_try_tree_read_lock(b
);
1842 btrfs_set_path_blocking(p
);
1843 btrfs_tree_read_lock(b
);
1844 btrfs_clear_path_blocking(p
, b
,
1847 p
->locks
[level
] = BTRFS_READ_LOCK
;
1849 p
->nodes
[level
] = b
;
1852 p
->slots
[level
] = slot
;
1854 btrfs_leaf_free_space(root
, b
) < ins_len
) {
1855 if (write_lock_level
< 1) {
1856 write_lock_level
= 1;
1857 btrfs_release_path(p
);
1861 btrfs_set_path_blocking(p
);
1862 err
= split_leaf(trans
, root
, key
,
1863 p
, ins_len
, ret
== 0);
1864 btrfs_clear_path_blocking(p
, NULL
, 0);
1872 if (!p
->search_for_split
)
1873 unlock_up(p
, level
, lowest_unlock
);
1880 * we don't really know what they plan on doing with the path
1881 * from here on, so for now just mark it as blocking
1883 if (!p
->leave_spinning
)
1884 btrfs_set_path_blocking(p
);
1886 btrfs_release_path(p
);
1891 * adjust the pointers going up the tree, starting at level
1892 * making sure the right key of each node is points to 'key'.
1893 * This is used after shifting pointers to the left, so it stops
1894 * fixing up pointers when a given leaf/node is not in slot 0 of the
1897 * If this fails to write a tree block, it returns -1, but continues
1898 * fixing up the blocks in ram so the tree is consistent.
1900 static int fixup_low_keys(struct btrfs_trans_handle
*trans
,
1901 struct btrfs_root
*root
, struct btrfs_path
*path
,
1902 struct btrfs_disk_key
*key
, int level
)
1906 struct extent_buffer
*t
;
1908 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
1909 int tslot
= path
->slots
[i
];
1910 if (!path
->nodes
[i
])
1913 btrfs_set_node_key(t
, key
, tslot
);
1914 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
1924 * This function isn't completely safe. It's the caller's responsibility
1925 * that the new key won't break the order
1927 int btrfs_set_item_key_safe(struct btrfs_trans_handle
*trans
,
1928 struct btrfs_root
*root
, struct btrfs_path
*path
,
1929 struct btrfs_key
*new_key
)
1931 struct btrfs_disk_key disk_key
;
1932 struct extent_buffer
*eb
;
1935 eb
= path
->nodes
[0];
1936 slot
= path
->slots
[0];
1938 btrfs_item_key(eb
, &disk_key
, slot
- 1);
1939 if (comp_keys(&disk_key
, new_key
) >= 0)
1942 if (slot
< btrfs_header_nritems(eb
) - 1) {
1943 btrfs_item_key(eb
, &disk_key
, slot
+ 1);
1944 if (comp_keys(&disk_key
, new_key
) <= 0)
1948 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
1949 btrfs_set_item_key(eb
, &disk_key
, slot
);
1950 btrfs_mark_buffer_dirty(eb
);
1952 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
1957 * try to push data from one node into the next node left in the
1960 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
1961 * error, and > 0 if there was no room in the left hand block.
1963 static int push_node_left(struct btrfs_trans_handle
*trans
,
1964 struct btrfs_root
*root
, struct extent_buffer
*dst
,
1965 struct extent_buffer
*src
, int empty
)
1972 src_nritems
= btrfs_header_nritems(src
);
1973 dst_nritems
= btrfs_header_nritems(dst
);
1974 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
1975 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
1976 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
1978 if (!empty
&& src_nritems
<= 8)
1981 if (push_items
<= 0)
1985 push_items
= min(src_nritems
, push_items
);
1986 if (push_items
< src_nritems
) {
1987 /* leave at least 8 pointers in the node if
1988 * we aren't going to empty it
1990 if (src_nritems
- push_items
< 8) {
1991 if (push_items
<= 8)
1997 push_items
= min(src_nritems
- 8, push_items
);
1999 copy_extent_buffer(dst
, src
,
2000 btrfs_node_key_ptr_offset(dst_nritems
),
2001 btrfs_node_key_ptr_offset(0),
2002 push_items
* sizeof(struct btrfs_key_ptr
));
2004 if (push_items
< src_nritems
) {
2005 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
2006 btrfs_node_key_ptr_offset(push_items
),
2007 (src_nritems
- push_items
) *
2008 sizeof(struct btrfs_key_ptr
));
2010 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
2011 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
2012 btrfs_mark_buffer_dirty(src
);
2013 btrfs_mark_buffer_dirty(dst
);
2019 * try to push data from one node into the next node right in the
2022 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
2023 * error, and > 0 if there was no room in the right hand block.
2025 * this will only push up to 1/2 the contents of the left node over
2027 static int balance_node_right(struct btrfs_trans_handle
*trans
,
2028 struct btrfs_root
*root
,
2029 struct extent_buffer
*dst
,
2030 struct extent_buffer
*src
)
2038 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
2039 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
2041 src_nritems
= btrfs_header_nritems(src
);
2042 dst_nritems
= btrfs_header_nritems(dst
);
2043 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
2044 if (push_items
<= 0)
2047 if (src_nritems
< 4)
2050 max_push
= src_nritems
/ 2 + 1;
2051 /* don't try to empty the node */
2052 if (max_push
>= src_nritems
)
2055 if (max_push
< push_items
)
2056 push_items
= max_push
;
2058 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
2059 btrfs_node_key_ptr_offset(0),
2061 sizeof(struct btrfs_key_ptr
));
2063 copy_extent_buffer(dst
, src
,
2064 btrfs_node_key_ptr_offset(0),
2065 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
2066 push_items
* sizeof(struct btrfs_key_ptr
));
2068 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
2069 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
2071 btrfs_mark_buffer_dirty(src
);
2072 btrfs_mark_buffer_dirty(dst
);
2078 * helper function to insert a new root level in the tree.
2079 * A new node is allocated, and a single item is inserted to
2080 * point to the existing root
2082 * returns zero on success or < 0 on failure.
2084 static noinline
int insert_new_root(struct btrfs_trans_handle
*trans
,
2085 struct btrfs_root
*root
,
2086 struct btrfs_path
*path
, int level
)
2089 struct extent_buffer
*lower
;
2090 struct extent_buffer
*c
;
2091 struct extent_buffer
*old
;
2092 struct btrfs_disk_key lower_key
;
2094 BUG_ON(path
->nodes
[level
]);
2095 BUG_ON(path
->nodes
[level
-1] != root
->node
);
2097 lower
= path
->nodes
[level
-1];
2099 btrfs_item_key(lower
, &lower_key
, 0);
2101 btrfs_node_key(lower
, &lower_key
, 0);
2103 c
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
2104 root
->root_key
.objectid
, &lower_key
,
2105 level
, root
->node
->start
, 0, 0);
2109 root_add_used(root
, root
->nodesize
);
2111 memset_extent_buffer(c
, 0, 0, sizeof(struct btrfs_header
));
2112 btrfs_set_header_nritems(c
, 1);
2113 btrfs_set_header_level(c
, level
);
2114 btrfs_set_header_bytenr(c
, c
->start
);
2115 btrfs_set_header_generation(c
, trans
->transid
);
2116 btrfs_set_header_backref_rev(c
, BTRFS_MIXED_BACKREF_REV
);
2117 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
2119 write_extent_buffer(c
, root
->fs_info
->fsid
,
2120 (unsigned long)btrfs_header_fsid(c
),
2123 write_extent_buffer(c
, root
->fs_info
->chunk_tree_uuid
,
2124 (unsigned long)btrfs_header_chunk_tree_uuid(c
),
2127 btrfs_set_node_key(c
, &lower_key
, 0);
2128 btrfs_set_node_blockptr(c
, 0, lower
->start
);
2129 lower_gen
= btrfs_header_generation(lower
);
2130 WARN_ON(lower_gen
!= trans
->transid
);
2132 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
2134 btrfs_mark_buffer_dirty(c
);
2137 rcu_assign_pointer(root
->node
, c
);
2139 /* the super has an extra ref to root->node */
2140 free_extent_buffer(old
);
2142 add_root_to_dirty_list(root
);
2143 extent_buffer_get(c
);
2144 path
->nodes
[level
] = c
;
2145 path
->locks
[level
] = BTRFS_WRITE_LOCK
;
2146 path
->slots
[level
] = 0;
2151 * worker function to insert a single pointer in a node.
2152 * the node should have enough room for the pointer already
2154 * slot and level indicate where you want the key to go, and
2155 * blocknr is the block the key points to.
2157 * returns zero on success and < 0 on any error
2159 static int insert_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
2160 *root
, struct btrfs_path
*path
, struct btrfs_disk_key
2161 *key
, u64 bytenr
, int slot
, int level
)
2163 struct extent_buffer
*lower
;
2166 BUG_ON(!path
->nodes
[level
]);
2167 btrfs_assert_tree_locked(path
->nodes
[level
]);
2168 lower
= path
->nodes
[level
];
2169 nritems
= btrfs_header_nritems(lower
);
2170 BUG_ON(slot
> nritems
);
2171 if (nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
))
2173 if (slot
!= nritems
) {
2174 memmove_extent_buffer(lower
,
2175 btrfs_node_key_ptr_offset(slot
+ 1),
2176 btrfs_node_key_ptr_offset(slot
),
2177 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
2179 btrfs_set_node_key(lower
, key
, slot
);
2180 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
2181 WARN_ON(trans
->transid
== 0);
2182 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
2183 btrfs_set_header_nritems(lower
, nritems
+ 1);
2184 btrfs_mark_buffer_dirty(lower
);
2189 * split the node at the specified level in path in two.
2190 * The path is corrected to point to the appropriate node after the split
2192 * Before splitting this tries to make some room in the node by pushing
2193 * left and right, if either one works, it returns right away.
2195 * returns 0 on success and < 0 on failure
2197 static noinline
int split_node(struct btrfs_trans_handle
*trans
,
2198 struct btrfs_root
*root
,
2199 struct btrfs_path
*path
, int level
)
2201 struct extent_buffer
*c
;
2202 struct extent_buffer
*split
;
2203 struct btrfs_disk_key disk_key
;
2209 c
= path
->nodes
[level
];
2210 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
2211 if (c
== root
->node
) {
2212 /* trying to split the root, lets make a new one */
2213 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
2217 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
2218 c
= path
->nodes
[level
];
2219 if (!ret
&& btrfs_header_nritems(c
) <
2220 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3)
2226 c_nritems
= btrfs_header_nritems(c
);
2227 mid
= (c_nritems
+ 1) / 2;
2228 btrfs_node_key(c
, &disk_key
, mid
);
2230 split
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
2231 root
->root_key
.objectid
,
2232 &disk_key
, level
, c
->start
, 0, 0);
2234 return PTR_ERR(split
);
2236 root_add_used(root
, root
->nodesize
);
2238 memset_extent_buffer(split
, 0, 0, sizeof(struct btrfs_header
));
2239 btrfs_set_header_level(split
, btrfs_header_level(c
));
2240 btrfs_set_header_bytenr(split
, split
->start
);
2241 btrfs_set_header_generation(split
, trans
->transid
);
2242 btrfs_set_header_backref_rev(split
, BTRFS_MIXED_BACKREF_REV
);
2243 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
2244 write_extent_buffer(split
, root
->fs_info
->fsid
,
2245 (unsigned long)btrfs_header_fsid(split
),
2247 write_extent_buffer(split
, root
->fs_info
->chunk_tree_uuid
,
2248 (unsigned long)btrfs_header_chunk_tree_uuid(split
),
2252 copy_extent_buffer(split
, c
,
2253 btrfs_node_key_ptr_offset(0),
2254 btrfs_node_key_ptr_offset(mid
),
2255 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
2256 btrfs_set_header_nritems(split
, c_nritems
- mid
);
2257 btrfs_set_header_nritems(c
, mid
);
2260 btrfs_mark_buffer_dirty(c
);
2261 btrfs_mark_buffer_dirty(split
);
2263 wret
= insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
2264 path
->slots
[level
+ 1] + 1,
2269 if (path
->slots
[level
] >= mid
) {
2270 path
->slots
[level
] -= mid
;
2271 btrfs_tree_unlock(c
);
2272 free_extent_buffer(c
);
2273 path
->nodes
[level
] = split
;
2274 path
->slots
[level
+ 1] += 1;
2276 btrfs_tree_unlock(split
);
2277 free_extent_buffer(split
);
2283 * how many bytes are required to store the items in a leaf. start
2284 * and nr indicate which items in the leaf to check. This totals up the
2285 * space used both by the item structs and the item data
2287 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
2290 int nritems
= btrfs_header_nritems(l
);
2291 int end
= min(nritems
, start
+ nr
) - 1;
2295 data_len
= btrfs_item_end_nr(l
, start
);
2296 data_len
= data_len
- btrfs_item_offset_nr(l
, end
);
2297 data_len
+= sizeof(struct btrfs_item
) * nr
;
2298 WARN_ON(data_len
< 0);
2303 * The space between the end of the leaf items and
2304 * the start of the leaf data. IOW, how much room
2305 * the leaf has left for both items and data
2307 noinline
int btrfs_leaf_free_space(struct btrfs_root
*root
,
2308 struct extent_buffer
*leaf
)
2310 int nritems
= btrfs_header_nritems(leaf
);
2312 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
2314 printk(KERN_CRIT
"leaf free space ret %d, leaf data size %lu, "
2315 "used %d nritems %d\n",
2316 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
2317 leaf_space_used(leaf
, 0, nritems
), nritems
);
2323 * min slot controls the lowest index we're willing to push to the
2324 * right. We'll push up to and including min_slot, but no lower
2326 static noinline
int __push_leaf_right(struct btrfs_trans_handle
*trans
,
2327 struct btrfs_root
*root
,
2328 struct btrfs_path
*path
,
2329 int data_size
, int empty
,
2330 struct extent_buffer
*right
,
2331 int free_space
, u32 left_nritems
,
2334 struct extent_buffer
*left
= path
->nodes
[0];
2335 struct extent_buffer
*upper
= path
->nodes
[1];
2336 struct btrfs_map_token token
;
2337 struct btrfs_disk_key disk_key
;
2342 struct btrfs_item
*item
;
2348 btrfs_init_map_token(&token
);
2353 nr
= max_t(u32
, 1, min_slot
);
2355 if (path
->slots
[0] >= left_nritems
)
2356 push_space
+= data_size
;
2358 slot
= path
->slots
[1];
2359 i
= left_nritems
- 1;
2361 item
= btrfs_item_nr(left
, i
);
2363 if (!empty
&& push_items
> 0) {
2364 if (path
->slots
[0] > i
)
2366 if (path
->slots
[0] == i
) {
2367 int space
= btrfs_leaf_free_space(root
, left
);
2368 if (space
+ push_space
* 2 > free_space
)
2373 if (path
->slots
[0] == i
)
2374 push_space
+= data_size
;
2376 this_item_size
= btrfs_item_size(left
, item
);
2377 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
2381 push_space
+= this_item_size
+ sizeof(*item
);
2387 if (push_items
== 0)
2390 if (!empty
&& push_items
== left_nritems
)
2393 /* push left to right */
2394 right_nritems
= btrfs_header_nritems(right
);
2396 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
2397 push_space
-= leaf_data_end(root
, left
);
2399 /* make room in the right data area */
2400 data_end
= leaf_data_end(root
, right
);
2401 memmove_extent_buffer(right
,
2402 btrfs_leaf_data(right
) + data_end
- push_space
,
2403 btrfs_leaf_data(right
) + data_end
,
2404 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
2406 /* copy from the left data area */
2407 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
2408 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
2409 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
2412 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
2413 btrfs_item_nr_offset(0),
2414 right_nritems
* sizeof(struct btrfs_item
));
2416 /* copy the items from left to right */
2417 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
2418 btrfs_item_nr_offset(left_nritems
- push_items
),
2419 push_items
* sizeof(struct btrfs_item
));
2421 /* update the item pointers */
2422 right_nritems
+= push_items
;
2423 btrfs_set_header_nritems(right
, right_nritems
);
2424 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
2425 for (i
= 0; i
< right_nritems
; i
++) {
2426 item
= btrfs_item_nr(right
, i
);
2427 push_space
-= btrfs_token_item_size(right
, item
, &token
);
2428 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
2431 left_nritems
-= push_items
;
2432 btrfs_set_header_nritems(left
, left_nritems
);
2435 btrfs_mark_buffer_dirty(left
);
2437 clean_tree_block(trans
, root
, left
);
2439 btrfs_mark_buffer_dirty(right
);
2441 btrfs_item_key(right
, &disk_key
, 0);
2442 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
2443 btrfs_mark_buffer_dirty(upper
);
2445 /* then fixup the leaf pointer in the path */
2446 if (path
->slots
[0] >= left_nritems
) {
2447 path
->slots
[0] -= left_nritems
;
2448 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
2449 clean_tree_block(trans
, root
, path
->nodes
[0]);
2450 btrfs_tree_unlock(path
->nodes
[0]);
2451 free_extent_buffer(path
->nodes
[0]);
2452 path
->nodes
[0] = right
;
2453 path
->slots
[1] += 1;
2455 btrfs_tree_unlock(right
);
2456 free_extent_buffer(right
);
2461 btrfs_tree_unlock(right
);
2462 free_extent_buffer(right
);
2467 * push some data in the path leaf to the right, trying to free up at
2468 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2470 * returns 1 if the push failed because the other node didn't have enough
2471 * room, 0 if everything worked out and < 0 if there were major errors.
2473 * this will push starting from min_slot to the end of the leaf. It won't
2474 * push any slot lower than min_slot
2476 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
2477 *root
, struct btrfs_path
*path
,
2478 int min_data_size
, int data_size
,
2479 int empty
, u32 min_slot
)
2481 struct extent_buffer
*left
= path
->nodes
[0];
2482 struct extent_buffer
*right
;
2483 struct extent_buffer
*upper
;
2489 if (!path
->nodes
[1])
2492 slot
= path
->slots
[1];
2493 upper
= path
->nodes
[1];
2494 if (slot
>= btrfs_header_nritems(upper
) - 1)
2497 btrfs_assert_tree_locked(path
->nodes
[1]);
2499 right
= read_node_slot(root
, upper
, slot
+ 1);
2503 btrfs_tree_lock(right
);
2504 btrfs_set_lock_blocking(right
);
2506 free_space
= btrfs_leaf_free_space(root
, right
);
2507 if (free_space
< data_size
)
2510 /* cow and double check */
2511 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
2516 free_space
= btrfs_leaf_free_space(root
, right
);
2517 if (free_space
< data_size
)
2520 left_nritems
= btrfs_header_nritems(left
);
2521 if (left_nritems
== 0)
2524 return __push_leaf_right(trans
, root
, path
, min_data_size
, empty
,
2525 right
, free_space
, left_nritems
, min_slot
);
2527 btrfs_tree_unlock(right
);
2528 free_extent_buffer(right
);
2533 * push some data in the path leaf to the left, trying to free up at
2534 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2536 * max_slot can put a limit on how far into the leaf we'll push items. The
2537 * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
2540 static noinline
int __push_leaf_left(struct btrfs_trans_handle
*trans
,
2541 struct btrfs_root
*root
,
2542 struct btrfs_path
*path
, int data_size
,
2543 int empty
, struct extent_buffer
*left
,
2544 int free_space
, u32 right_nritems
,
2547 struct btrfs_disk_key disk_key
;
2548 struct extent_buffer
*right
= path
->nodes
[0];
2552 struct btrfs_item
*item
;
2553 u32 old_left_nritems
;
2558 u32 old_left_item_size
;
2559 struct btrfs_map_token token
;
2561 btrfs_init_map_token(&token
);
2564 nr
= min(right_nritems
, max_slot
);
2566 nr
= min(right_nritems
- 1, max_slot
);
2568 for (i
= 0; i
< nr
; i
++) {
2569 item
= btrfs_item_nr(right
, i
);
2571 if (!empty
&& push_items
> 0) {
2572 if (path
->slots
[0] < i
)
2574 if (path
->slots
[0] == i
) {
2575 int space
= btrfs_leaf_free_space(root
, right
);
2576 if (space
+ push_space
* 2 > free_space
)
2581 if (path
->slots
[0] == i
)
2582 push_space
+= data_size
;
2584 this_item_size
= btrfs_item_size(right
, item
);
2585 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
2589 push_space
+= this_item_size
+ sizeof(*item
);
2592 if (push_items
== 0) {
2596 if (!empty
&& push_items
== btrfs_header_nritems(right
))
2599 /* push data from right to left */
2600 copy_extent_buffer(left
, right
,
2601 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
2602 btrfs_item_nr_offset(0),
2603 push_items
* sizeof(struct btrfs_item
));
2605 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
2606 btrfs_item_offset_nr(right
, push_items
- 1);
2608 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
2609 leaf_data_end(root
, left
) - push_space
,
2610 btrfs_leaf_data(right
) +
2611 btrfs_item_offset_nr(right
, push_items
- 1),
2613 old_left_nritems
= btrfs_header_nritems(left
);
2614 BUG_ON(old_left_nritems
<= 0);
2616 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
2617 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
2620 item
= btrfs_item_nr(left
, i
);
2622 ioff
= btrfs_token_item_offset(left
, item
, &token
);
2623 btrfs_set_token_item_offset(left
, item
,
2624 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
),
2627 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
2629 /* fixup right node */
2630 if (push_items
> right_nritems
) {
2631 printk(KERN_CRIT
"push items %d nr %u\n", push_items
,
2636 if (push_items
< right_nritems
) {
2637 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
2638 leaf_data_end(root
, right
);
2639 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
2640 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
2641 btrfs_leaf_data(right
) +
2642 leaf_data_end(root
, right
), push_space
);
2644 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
2645 btrfs_item_nr_offset(push_items
),
2646 (btrfs_header_nritems(right
) - push_items
) *
2647 sizeof(struct btrfs_item
));
2649 right_nritems
-= push_items
;
2650 btrfs_set_header_nritems(right
, right_nritems
);
2651 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
2652 for (i
= 0; i
< right_nritems
; i
++) {
2653 item
= btrfs_item_nr(right
, i
);
2655 push_space
= push_space
- btrfs_token_item_size(right
,
2657 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
2660 btrfs_mark_buffer_dirty(left
);
2662 btrfs_mark_buffer_dirty(right
);
2664 clean_tree_block(trans
, root
, right
);
2666 btrfs_item_key(right
, &disk_key
, 0);
2667 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
2671 /* then fixup the leaf pointer in the path */
2672 if (path
->slots
[0] < push_items
) {
2673 path
->slots
[0] += old_left_nritems
;
2674 btrfs_tree_unlock(path
->nodes
[0]);
2675 free_extent_buffer(path
->nodes
[0]);
2676 path
->nodes
[0] = left
;
2677 path
->slots
[1] -= 1;
2679 btrfs_tree_unlock(left
);
2680 free_extent_buffer(left
);
2681 path
->slots
[0] -= push_items
;
2683 BUG_ON(path
->slots
[0] < 0);
2686 btrfs_tree_unlock(left
);
2687 free_extent_buffer(left
);
2692 * push some data in the path leaf to the left, trying to free up at
2693 * least data_size bytes. returns zero if the push worked, nonzero otherwise
2695 * max_slot can put a limit on how far into the leaf we'll push items. The
2696 * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
2699 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
2700 *root
, struct btrfs_path
*path
, int min_data_size
,
2701 int data_size
, int empty
, u32 max_slot
)
2703 struct extent_buffer
*right
= path
->nodes
[0];
2704 struct extent_buffer
*left
;
2710 slot
= path
->slots
[1];
2713 if (!path
->nodes
[1])
2716 right_nritems
= btrfs_header_nritems(right
);
2717 if (right_nritems
== 0)
2720 btrfs_assert_tree_locked(path
->nodes
[1]);
2722 left
= read_node_slot(root
, path
->nodes
[1], slot
- 1);
2726 btrfs_tree_lock(left
);
2727 btrfs_set_lock_blocking(left
);
2729 free_space
= btrfs_leaf_free_space(root
, left
);
2730 if (free_space
< data_size
) {
2735 /* cow and double check */
2736 ret
= btrfs_cow_block(trans
, root
, left
,
2737 path
->nodes
[1], slot
- 1, &left
);
2739 /* we hit -ENOSPC, but it isn't fatal here */
2744 free_space
= btrfs_leaf_free_space(root
, left
);
2745 if (free_space
< data_size
) {
2750 return __push_leaf_left(trans
, root
, path
, min_data_size
,
2751 empty
, left
, free_space
, right_nritems
,
2754 btrfs_tree_unlock(left
);
2755 free_extent_buffer(left
);
2760 * split the path's leaf in two, making sure there is at least data_size
2761 * available for the resulting leaf level of the path.
2763 * returns 0 if all went well and < 0 on failure.
2765 static noinline
int copy_for_split(struct btrfs_trans_handle
*trans
,
2766 struct btrfs_root
*root
,
2767 struct btrfs_path
*path
,
2768 struct extent_buffer
*l
,
2769 struct extent_buffer
*right
,
2770 int slot
, int mid
, int nritems
)
2777 struct btrfs_disk_key disk_key
;
2778 struct btrfs_map_token token
;
2780 btrfs_init_map_token(&token
);
2782 nritems
= nritems
- mid
;
2783 btrfs_set_header_nritems(right
, nritems
);
2784 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
2786 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
2787 btrfs_item_nr_offset(mid
),
2788 nritems
* sizeof(struct btrfs_item
));
2790 copy_extent_buffer(right
, l
,
2791 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
2792 data_copy_size
, btrfs_leaf_data(l
) +
2793 leaf_data_end(root
, l
), data_copy_size
);
2795 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
2796 btrfs_item_end_nr(l
, mid
);
2798 for (i
= 0; i
< nritems
; i
++) {
2799 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
2802 ioff
= btrfs_token_item_offset(right
, item
, &token
);
2803 btrfs_set_token_item_offset(right
, item
,
2804 ioff
+ rt_data_off
, &token
);
2807 btrfs_set_header_nritems(l
, mid
);
2809 btrfs_item_key(right
, &disk_key
, 0);
2810 wret
= insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
2811 path
->slots
[1] + 1, 1);
2815 btrfs_mark_buffer_dirty(right
);
2816 btrfs_mark_buffer_dirty(l
);
2817 BUG_ON(path
->slots
[0] != slot
);
2820 btrfs_tree_unlock(path
->nodes
[0]);
2821 free_extent_buffer(path
->nodes
[0]);
2822 path
->nodes
[0] = right
;
2823 path
->slots
[0] -= mid
;
2824 path
->slots
[1] += 1;
2826 btrfs_tree_unlock(right
);
2827 free_extent_buffer(right
);
2830 BUG_ON(path
->slots
[0] < 0);
2836 * double splits happen when we need to insert a big item in the middle
2837 * of a leaf. A double split can leave us with 3 mostly empty leaves:
2838 * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
2841 * We avoid this by trying to push the items on either side of our target
2842 * into the adjacent leaves. If all goes well we can avoid the double split
2845 static noinline
int push_for_double_split(struct btrfs_trans_handle
*trans
,
2846 struct btrfs_root
*root
,
2847 struct btrfs_path
*path
,
2855 slot
= path
->slots
[0];
2858 * try to push all the items after our slot into the
2861 ret
= push_leaf_right(trans
, root
, path
, 1, data_size
, 0, slot
);
2868 nritems
= btrfs_header_nritems(path
->nodes
[0]);
2870 * our goal is to get our slot at the start or end of a leaf. If
2871 * we've done so we're done
2873 if (path
->slots
[0] == 0 || path
->slots
[0] == nritems
)
2876 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
2879 /* try to push all the items before our slot into the next leaf */
2880 slot
= path
->slots
[0];
2881 ret
= push_leaf_left(trans
, root
, path
, 1, data_size
, 0, slot
);
2894 * split the path's leaf in two, making sure there is at least data_size
2895 * available for the resulting leaf level of the path.
2897 * returns 0 if all went well and < 0 on failure.
2899 static noinline
int split_leaf(struct btrfs_trans_handle
*trans
,
2900 struct btrfs_root
*root
,
2901 struct btrfs_key
*ins_key
,
2902 struct btrfs_path
*path
, int data_size
,
2905 struct btrfs_disk_key disk_key
;
2906 struct extent_buffer
*l
;
2910 struct extent_buffer
*right
;
2914 int num_doubles
= 0;
2915 int tried_avoid_double
= 0;
2918 slot
= path
->slots
[0];
2919 if (extend
&& data_size
+ btrfs_item_size_nr(l
, slot
) +
2920 sizeof(struct btrfs_item
) > BTRFS_LEAF_DATA_SIZE(root
))
2923 /* first try to make some room by pushing left and right */
2925 wret
= push_leaf_right(trans
, root
, path
, data_size
,
2930 wret
= push_leaf_left(trans
, root
, path
, data_size
,
2931 data_size
, 0, (u32
)-1);
2937 /* did the pushes work? */
2938 if (btrfs_leaf_free_space(root
, l
) >= data_size
)
2942 if (!path
->nodes
[1]) {
2943 ret
= insert_new_root(trans
, root
, path
, 1);
2950 slot
= path
->slots
[0];
2951 nritems
= btrfs_header_nritems(l
);
2952 mid
= (nritems
+ 1) / 2;
2956 leaf_space_used(l
, mid
, nritems
- mid
) + data_size
>
2957 BTRFS_LEAF_DATA_SIZE(root
)) {
2958 if (slot
>= nritems
) {
2962 if (mid
!= nritems
&&
2963 leaf_space_used(l
, mid
, nritems
- mid
) +
2964 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
2965 if (data_size
&& !tried_avoid_double
)
2966 goto push_for_double
;
2972 if (leaf_space_used(l
, 0, mid
) + data_size
>
2973 BTRFS_LEAF_DATA_SIZE(root
)) {
2974 if (!extend
&& data_size
&& slot
== 0) {
2976 } else if ((extend
|| !data_size
) && slot
== 0) {
2980 if (mid
!= nritems
&&
2981 leaf_space_used(l
, mid
, nritems
- mid
) +
2982 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
2983 if (data_size
&& !tried_avoid_double
)
2984 goto push_for_double
;
2992 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
2994 btrfs_item_key(l
, &disk_key
, mid
);
2996 right
= btrfs_alloc_free_block(trans
, root
, root
->leafsize
, 0,
2997 root
->root_key
.objectid
,
2998 &disk_key
, 0, l
->start
, 0, 0);
3000 return PTR_ERR(right
);
3002 root_add_used(root
, root
->leafsize
);
3004 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
3005 btrfs_set_header_bytenr(right
, right
->start
);
3006 btrfs_set_header_generation(right
, trans
->transid
);
3007 btrfs_set_header_backref_rev(right
, BTRFS_MIXED_BACKREF_REV
);
3008 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
3009 btrfs_set_header_level(right
, 0);
3010 write_extent_buffer(right
, root
->fs_info
->fsid
,
3011 (unsigned long)btrfs_header_fsid(right
),
3014 write_extent_buffer(right
, root
->fs_info
->chunk_tree_uuid
,
3015 (unsigned long)btrfs_header_chunk_tree_uuid(right
),
3020 btrfs_set_header_nritems(right
, 0);
3021 wret
= insert_ptr(trans
, root
, path
,
3022 &disk_key
, right
->start
,
3023 path
->slots
[1] + 1, 1);
3027 btrfs_tree_unlock(path
->nodes
[0]);
3028 free_extent_buffer(path
->nodes
[0]);
3029 path
->nodes
[0] = right
;
3031 path
->slots
[1] += 1;
3033 btrfs_set_header_nritems(right
, 0);
3034 wret
= insert_ptr(trans
, root
, path
,
3040 btrfs_tree_unlock(path
->nodes
[0]);
3041 free_extent_buffer(path
->nodes
[0]);
3042 path
->nodes
[0] = right
;
3044 if (path
->slots
[1] == 0) {
3045 wret
= fixup_low_keys(trans
, root
,
3046 path
, &disk_key
, 1);
3051 btrfs_mark_buffer_dirty(right
);
3055 ret
= copy_for_split(trans
, root
, path
, l
, right
, slot
, mid
, nritems
);
3059 BUG_ON(num_doubles
!= 0);
3067 push_for_double_split(trans
, root
, path
, data_size
);
3068 tried_avoid_double
= 1;
3069 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
3074 static noinline
int setup_leaf_for_split(struct btrfs_trans_handle
*trans
,
3075 struct btrfs_root
*root
,
3076 struct btrfs_path
*path
, int ins_len
)
3078 struct btrfs_key key
;
3079 struct extent_buffer
*leaf
;
3080 struct btrfs_file_extent_item
*fi
;
3085 leaf
= path
->nodes
[0];
3086 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3088 BUG_ON(key
.type
!= BTRFS_EXTENT_DATA_KEY
&&
3089 key
.type
!= BTRFS_EXTENT_CSUM_KEY
);
3091 if (btrfs_leaf_free_space(root
, leaf
) >= ins_len
)
3094 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
3095 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
3096 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3097 struct btrfs_file_extent_item
);
3098 extent_len
= btrfs_file_extent_num_bytes(leaf
, fi
);
3100 btrfs_release_path(path
);
3102 path
->keep_locks
= 1;
3103 path
->search_for_split
= 1;
3104 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
3105 path
->search_for_split
= 0;
3110 leaf
= path
->nodes
[0];
3111 /* if our item isn't there or got smaller, return now */
3112 if (ret
> 0 || item_size
!= btrfs_item_size_nr(leaf
, path
->slots
[0]))
3115 /* the leaf has changed, it now has room. return now */
3116 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= ins_len
)
3119 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
3120 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3121 struct btrfs_file_extent_item
);
3122 if (extent_len
!= btrfs_file_extent_num_bytes(leaf
, fi
))
3126 btrfs_set_path_blocking(path
);
3127 ret
= split_leaf(trans
, root
, &key
, path
, ins_len
, 1);
3131 path
->keep_locks
= 0;
3132 btrfs_unlock_up_safe(path
, 1);
3135 path
->keep_locks
= 0;
3139 static noinline
int split_item(struct btrfs_trans_handle
*trans
,
3140 struct btrfs_root
*root
,
3141 struct btrfs_path
*path
,
3142 struct btrfs_key
*new_key
,
3143 unsigned long split_offset
)
3145 struct extent_buffer
*leaf
;
3146 struct btrfs_item
*item
;
3147 struct btrfs_item
*new_item
;
3153 struct btrfs_disk_key disk_key
;
3155 leaf
= path
->nodes
[0];
3156 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < sizeof(struct btrfs_item
));
3158 btrfs_set_path_blocking(path
);
3160 item
= btrfs_item_nr(leaf
, path
->slots
[0]);
3161 orig_offset
= btrfs_item_offset(leaf
, item
);
3162 item_size
= btrfs_item_size(leaf
, item
);
3164 buf
= kmalloc(item_size
, GFP_NOFS
);
3168 read_extent_buffer(leaf
, buf
, btrfs_item_ptr_offset(leaf
,
3169 path
->slots
[0]), item_size
);
3171 slot
= path
->slots
[0] + 1;
3172 nritems
= btrfs_header_nritems(leaf
);
3173 if (slot
!= nritems
) {
3174 /* shift the items */
3175 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ 1),
3176 btrfs_item_nr_offset(slot
),
3177 (nritems
- slot
) * sizeof(struct btrfs_item
));
3180 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
3181 btrfs_set_item_key(leaf
, &disk_key
, slot
);
3183 new_item
= btrfs_item_nr(leaf
, slot
);
3185 btrfs_set_item_offset(leaf
, new_item
, orig_offset
);
3186 btrfs_set_item_size(leaf
, new_item
, item_size
- split_offset
);
3188 btrfs_set_item_offset(leaf
, item
,
3189 orig_offset
+ item_size
- split_offset
);
3190 btrfs_set_item_size(leaf
, item
, split_offset
);
3192 btrfs_set_header_nritems(leaf
, nritems
+ 1);
3194 /* write the data for the start of the original item */
3195 write_extent_buffer(leaf
, buf
,
3196 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
3199 /* write the data for the new item */
3200 write_extent_buffer(leaf
, buf
+ split_offset
,
3201 btrfs_item_ptr_offset(leaf
, slot
),
3202 item_size
- split_offset
);
3203 btrfs_mark_buffer_dirty(leaf
);
3205 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
3211 * This function splits a single item into two items,
3212 * giving 'new_key' to the new item and splitting the
3213 * old one at split_offset (from the start of the item).
3215 * The path may be released by this operation. After
3216 * the split, the path is pointing to the old item. The
3217 * new item is going to be in the same node as the old one.
3219 * Note, the item being split must be smaller enough to live alone on
3220 * a tree block with room for one extra struct btrfs_item
3222 * This allows us to split the item in place, keeping a lock on the
3223 * leaf the entire time.
3225 int btrfs_split_item(struct btrfs_trans_handle
*trans
,
3226 struct btrfs_root
*root
,
3227 struct btrfs_path
*path
,
3228 struct btrfs_key
*new_key
,
3229 unsigned long split_offset
)
3232 ret
= setup_leaf_for_split(trans
, root
, path
,
3233 sizeof(struct btrfs_item
));
3237 ret
= split_item(trans
, root
, path
, new_key
, split_offset
);
3242 * This function duplicate a item, giving 'new_key' to the new item.
3243 * It guarantees both items live in the same tree leaf and the new item
3244 * is contiguous with the original item.
3246 * This allows us to split file extent in place, keeping a lock on the
3247 * leaf the entire time.
3249 int btrfs_duplicate_item(struct btrfs_trans_handle
*trans
,
3250 struct btrfs_root
*root
,
3251 struct btrfs_path
*path
,
3252 struct btrfs_key
*new_key
)
3254 struct extent_buffer
*leaf
;
3258 leaf
= path
->nodes
[0];
3259 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
3260 ret
= setup_leaf_for_split(trans
, root
, path
,
3261 item_size
+ sizeof(struct btrfs_item
));
3266 ret
= setup_items_for_insert(trans
, root
, path
, new_key
, &item_size
,
3267 item_size
, item_size
+
3268 sizeof(struct btrfs_item
), 1);
3271 leaf
= path
->nodes
[0];
3272 memcpy_extent_buffer(leaf
,
3273 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
3274 btrfs_item_ptr_offset(leaf
, path
->slots
[0] - 1),
3280 * make the item pointed to by the path smaller. new_size indicates
3281 * how small to make it, and from_end tells us if we just chop bytes
3282 * off the end of the item or if we shift the item to chop bytes off
3285 int btrfs_truncate_item(struct btrfs_trans_handle
*trans
,
3286 struct btrfs_root
*root
,
3287 struct btrfs_path
*path
,
3288 u32 new_size
, int from_end
)
3291 struct extent_buffer
*leaf
;
3292 struct btrfs_item
*item
;
3294 unsigned int data_end
;
3295 unsigned int old_data_start
;
3296 unsigned int old_size
;
3297 unsigned int size_diff
;
3299 struct btrfs_map_token token
;
3301 btrfs_init_map_token(&token
);
3303 leaf
= path
->nodes
[0];
3304 slot
= path
->slots
[0];
3306 old_size
= btrfs_item_size_nr(leaf
, slot
);
3307 if (old_size
== new_size
)
3310 nritems
= btrfs_header_nritems(leaf
);
3311 data_end
= leaf_data_end(root
, leaf
);
3313 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
3315 size_diff
= old_size
- new_size
;
3318 BUG_ON(slot
>= nritems
);
3321 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3323 /* first correct the data pointers */
3324 for (i
= slot
; i
< nritems
; i
++) {
3326 item
= btrfs_item_nr(leaf
, i
);
3328 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
3329 btrfs_set_token_item_offset(leaf
, item
,
3330 ioff
+ size_diff
, &token
);
3333 /* shift the data */
3335 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3336 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
3337 data_end
, old_data_start
+ new_size
- data_end
);
3339 struct btrfs_disk_key disk_key
;
3342 btrfs_item_key(leaf
, &disk_key
, slot
);
3344 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
3346 struct btrfs_file_extent_item
*fi
;
3348 fi
= btrfs_item_ptr(leaf
, slot
,
3349 struct btrfs_file_extent_item
);
3350 fi
= (struct btrfs_file_extent_item
*)(
3351 (unsigned long)fi
- size_diff
);
3353 if (btrfs_file_extent_type(leaf
, fi
) ==
3354 BTRFS_FILE_EXTENT_INLINE
) {
3355 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
3356 memmove_extent_buffer(leaf
, ptr
,
3358 offsetof(struct btrfs_file_extent_item
,
3363 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3364 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
3365 data_end
, old_data_start
- data_end
);
3367 offset
= btrfs_disk_key_offset(&disk_key
);
3368 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
3369 btrfs_set_item_key(leaf
, &disk_key
, slot
);
3371 fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3374 item
= btrfs_item_nr(leaf
, slot
);
3375 btrfs_set_item_size(leaf
, item
, new_size
);
3376 btrfs_mark_buffer_dirty(leaf
);
3378 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3379 btrfs_print_leaf(root
, leaf
);
3386 * make the item pointed to by the path bigger, data_size is the new size.
3388 int btrfs_extend_item(struct btrfs_trans_handle
*trans
,
3389 struct btrfs_root
*root
, struct btrfs_path
*path
,
3393 struct extent_buffer
*leaf
;
3394 struct btrfs_item
*item
;
3396 unsigned int data_end
;
3397 unsigned int old_data
;
3398 unsigned int old_size
;
3400 struct btrfs_map_token token
;
3402 btrfs_init_map_token(&token
);
3404 leaf
= path
->nodes
[0];
3406 nritems
= btrfs_header_nritems(leaf
);
3407 data_end
= leaf_data_end(root
, leaf
);
3409 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
3410 btrfs_print_leaf(root
, leaf
);
3413 slot
= path
->slots
[0];
3414 old_data
= btrfs_item_end_nr(leaf
, slot
);
3417 if (slot
>= nritems
) {
3418 btrfs_print_leaf(root
, leaf
);
3419 printk(KERN_CRIT
"slot %d too large, nritems %d\n",
3425 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3427 /* first correct the data pointers */
3428 for (i
= slot
; i
< nritems
; i
++) {
3430 item
= btrfs_item_nr(leaf
, i
);
3432 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
3433 btrfs_set_token_item_offset(leaf
, item
,
3434 ioff
- data_size
, &token
);
3437 /* shift the data */
3438 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3439 data_end
- data_size
, btrfs_leaf_data(leaf
) +
3440 data_end
, old_data
- data_end
);
3442 data_end
= old_data
;
3443 old_size
= btrfs_item_size_nr(leaf
, slot
);
3444 item
= btrfs_item_nr(leaf
, slot
);
3445 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
3446 btrfs_mark_buffer_dirty(leaf
);
3448 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3449 btrfs_print_leaf(root
, leaf
);
3456 * Given a key and some data, insert items into the tree.
3457 * This does all the path init required, making room in the tree if needed.
3458 * Returns the number of keys that were inserted.
3460 int btrfs_insert_some_items(struct btrfs_trans_handle
*trans
,
3461 struct btrfs_root
*root
,
3462 struct btrfs_path
*path
,
3463 struct btrfs_key
*cpu_key
, u32
*data_size
,
3466 struct extent_buffer
*leaf
;
3467 struct btrfs_item
*item
;
3474 unsigned int data_end
;
3475 struct btrfs_disk_key disk_key
;
3476 struct btrfs_key found_key
;
3477 struct btrfs_map_token token
;
3479 btrfs_init_map_token(&token
);
3481 for (i
= 0; i
< nr
; i
++) {
3482 if (total_size
+ data_size
[i
] + sizeof(struct btrfs_item
) >
3483 BTRFS_LEAF_DATA_SIZE(root
)) {
3487 total_data
+= data_size
[i
];
3488 total_size
+= data_size
[i
] + sizeof(struct btrfs_item
);
3492 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
3498 leaf
= path
->nodes
[0];
3500 nritems
= btrfs_header_nritems(leaf
);
3501 data_end
= leaf_data_end(root
, leaf
);
3503 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
3504 for (i
= nr
; i
>= 0; i
--) {
3505 total_data
-= data_size
[i
];
3506 total_size
-= data_size
[i
] + sizeof(struct btrfs_item
);
3507 if (total_size
< btrfs_leaf_free_space(root
, leaf
))
3513 slot
= path
->slots
[0];
3516 if (slot
!= nritems
) {
3517 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
3519 item
= btrfs_item_nr(leaf
, slot
);
3520 btrfs_item_key_to_cpu(leaf
, &found_key
, slot
);
3522 /* figure out how many keys we can insert in here */
3523 total_data
= data_size
[0];
3524 for (i
= 1; i
< nr
; i
++) {
3525 if (btrfs_comp_cpu_keys(&found_key
, cpu_key
+ i
) <= 0)
3527 total_data
+= data_size
[i
];
3531 if (old_data
< data_end
) {
3532 btrfs_print_leaf(root
, leaf
);
3533 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
3534 slot
, old_data
, data_end
);
3538 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3540 /* first correct the data pointers */
3541 for (i
= slot
; i
< nritems
; i
++) {
3544 item
= btrfs_item_nr(leaf
, i
);
3545 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
3546 btrfs_set_token_item_offset(leaf
, item
,
3547 ioff
- total_data
, &token
);
3549 /* shift the items */
3550 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
3551 btrfs_item_nr_offset(slot
),
3552 (nritems
- slot
) * sizeof(struct btrfs_item
));
3554 /* shift the data */
3555 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3556 data_end
- total_data
, btrfs_leaf_data(leaf
) +
3557 data_end
, old_data
- data_end
);
3558 data_end
= old_data
;
3561 * this sucks but it has to be done, if we are inserting at
3562 * the end of the leaf only insert 1 of the items, since we
3563 * have no way of knowing whats on the next leaf and we'd have
3564 * to drop our current locks to figure it out
3569 /* setup the item for the new data */
3570 for (i
= 0; i
< nr
; i
++) {
3571 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
3572 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
3573 item
= btrfs_item_nr(leaf
, slot
+ i
);
3574 btrfs_set_token_item_offset(leaf
, item
,
3575 data_end
- data_size
[i
], &token
);
3576 data_end
-= data_size
[i
];
3577 btrfs_set_token_item_size(leaf
, item
, data_size
[i
], &token
);
3579 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
3580 btrfs_mark_buffer_dirty(leaf
);
3584 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
3585 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3588 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3589 btrfs_print_leaf(root
, leaf
);
3599 * this is a helper for btrfs_insert_empty_items, the main goal here is
3600 * to save stack depth by doing the bulk of the work in a function
3601 * that doesn't call btrfs_search_slot
3603 int setup_items_for_insert(struct btrfs_trans_handle
*trans
,
3604 struct btrfs_root
*root
, struct btrfs_path
*path
,
3605 struct btrfs_key
*cpu_key
, u32
*data_size
,
3606 u32 total_data
, u32 total_size
, int nr
)
3608 struct btrfs_item
*item
;
3611 unsigned int data_end
;
3612 struct btrfs_disk_key disk_key
;
3614 struct extent_buffer
*leaf
;
3616 struct btrfs_map_token token
;
3618 btrfs_init_map_token(&token
);
3620 leaf
= path
->nodes
[0];
3621 slot
= path
->slots
[0];
3623 nritems
= btrfs_header_nritems(leaf
);
3624 data_end
= leaf_data_end(root
, leaf
);
3626 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
3627 btrfs_print_leaf(root
, leaf
);
3628 printk(KERN_CRIT
"not enough freespace need %u have %d\n",
3629 total_size
, btrfs_leaf_free_space(root
, leaf
));
3633 if (slot
!= nritems
) {
3634 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
3636 if (old_data
< data_end
) {
3637 btrfs_print_leaf(root
, leaf
);
3638 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
3639 slot
, old_data
, data_end
);
3643 * item0..itemN ... dataN.offset..dataN.size .. data0.size
3645 /* first correct the data pointers */
3646 for (i
= slot
; i
< nritems
; i
++) {
3649 item
= btrfs_item_nr(leaf
, i
);
3650 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
3651 btrfs_set_token_item_offset(leaf
, item
,
3652 ioff
- total_data
, &token
);
3654 /* shift the items */
3655 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
3656 btrfs_item_nr_offset(slot
),
3657 (nritems
- slot
) * sizeof(struct btrfs_item
));
3659 /* shift the data */
3660 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3661 data_end
- total_data
, btrfs_leaf_data(leaf
) +
3662 data_end
, old_data
- data_end
);
3663 data_end
= old_data
;
3666 /* setup the item for the new data */
3667 for (i
= 0; i
< nr
; i
++) {
3668 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
3669 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
3670 item
= btrfs_item_nr(leaf
, slot
+ i
);
3671 btrfs_set_token_item_offset(leaf
, item
,
3672 data_end
- data_size
[i
], &token
);
3673 data_end
-= data_size
[i
];
3674 btrfs_set_token_item_size(leaf
, item
, data_size
[i
], &token
);
3677 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
3681 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
3682 ret
= fixup_low_keys(trans
, root
, path
, &disk_key
, 1);
3684 btrfs_unlock_up_safe(path
, 1);
3685 btrfs_mark_buffer_dirty(leaf
);
3687 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
3688 btrfs_print_leaf(root
, leaf
);
3695 * Given a key and some data, insert items into the tree.
3696 * This does all the path init required, making room in the tree if needed.
3698 int btrfs_insert_empty_items(struct btrfs_trans_handle
*trans
,
3699 struct btrfs_root
*root
,
3700 struct btrfs_path
*path
,
3701 struct btrfs_key
*cpu_key
, u32
*data_size
,
3710 for (i
= 0; i
< nr
; i
++)
3711 total_data
+= data_size
[i
];
3713 total_size
= total_data
+ (nr
* sizeof(struct btrfs_item
));
3714 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
3720 slot
= path
->slots
[0];
3723 ret
= setup_items_for_insert(trans
, root
, path
, cpu_key
, data_size
,
3724 total_data
, total_size
, nr
);
3731 * Given a key and some data, insert an item into the tree.
3732 * This does all the path init required, making room in the tree if needed.
3734 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
3735 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
3739 struct btrfs_path
*path
;
3740 struct extent_buffer
*leaf
;
3743 path
= btrfs_alloc_path();
3746 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
3748 leaf
= path
->nodes
[0];
3749 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
3750 write_extent_buffer(leaf
, data
, ptr
, data_size
);
3751 btrfs_mark_buffer_dirty(leaf
);
3753 btrfs_free_path(path
);
3758 * delete the pointer from a given node.
3760 * the tree should have been previously balanced so the deletion does not
3763 static int del_ptr(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
3764 struct btrfs_path
*path
, int level
, int slot
)
3766 struct extent_buffer
*parent
= path
->nodes
[level
];
3771 nritems
= btrfs_header_nritems(parent
);
3772 if (slot
!= nritems
- 1) {
3773 memmove_extent_buffer(parent
,
3774 btrfs_node_key_ptr_offset(slot
),
3775 btrfs_node_key_ptr_offset(slot
+ 1),
3776 sizeof(struct btrfs_key_ptr
) *
3777 (nritems
- slot
- 1));
3780 btrfs_set_header_nritems(parent
, nritems
);
3781 if (nritems
== 0 && parent
== root
->node
) {
3782 BUG_ON(btrfs_header_level(root
->node
) != 1);
3783 /* just turn the root into a leaf and break */
3784 btrfs_set_header_level(root
->node
, 0);
3785 } else if (slot
== 0) {
3786 struct btrfs_disk_key disk_key
;
3788 btrfs_node_key(parent
, &disk_key
, 0);
3789 wret
= fixup_low_keys(trans
, root
, path
, &disk_key
, level
+ 1);
3793 btrfs_mark_buffer_dirty(parent
);
3798 * a helper function to delete the leaf pointed to by path->slots[1] and
3801 * This deletes the pointer in path->nodes[1] and frees the leaf
3802 * block extent. zero is returned if it all worked out, < 0 otherwise.
3804 * The path must have already been setup for deleting the leaf, including
3805 * all the proper balancing. path->nodes[1] must be locked.
3807 static noinline
int btrfs_del_leaf(struct btrfs_trans_handle
*trans
,
3808 struct btrfs_root
*root
,
3809 struct btrfs_path
*path
,
3810 struct extent_buffer
*leaf
)
3814 WARN_ON(btrfs_header_generation(leaf
) != trans
->transid
);
3815 ret
= del_ptr(trans
, root
, path
, 1, path
->slots
[1]);
3820 * btrfs_free_extent is expensive, we want to make sure we
3821 * aren't holding any locks when we call it
3823 btrfs_unlock_up_safe(path
, 0);
3825 root_sub_used(root
, leaf
->len
);
3827 extent_buffer_get(leaf
);
3828 btrfs_free_tree_block(trans
, root
, leaf
, 0, 1, 0);
3829 free_extent_buffer_stale(leaf
);
3833 * delete the item at the leaf level in path. If that empties
3834 * the leaf, remove it from the tree
3836 int btrfs_del_items(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
3837 struct btrfs_path
*path
, int slot
, int nr
)
3839 struct extent_buffer
*leaf
;
3840 struct btrfs_item
*item
;
3847 struct btrfs_map_token token
;
3849 btrfs_init_map_token(&token
);
3851 leaf
= path
->nodes
[0];
3852 last_off
= btrfs_item_offset_nr(leaf
, slot
+ nr
- 1);
3854 for (i
= 0; i
< nr
; i
++)
3855 dsize
+= btrfs_item_size_nr(leaf
, slot
+ i
);
3857 nritems
= btrfs_header_nritems(leaf
);
3859 if (slot
+ nr
!= nritems
) {
3860 int data_end
= leaf_data_end(root
, leaf
);
3862 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
3864 btrfs_leaf_data(leaf
) + data_end
,
3865 last_off
- data_end
);
3867 for (i
= slot
+ nr
; i
< nritems
; i
++) {
3870 item
= btrfs_item_nr(leaf
, i
);
3871 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
3872 btrfs_set_token_item_offset(leaf
, item
,
3873 ioff
+ dsize
, &token
);
3876 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
3877 btrfs_item_nr_offset(slot
+ nr
),
3878 sizeof(struct btrfs_item
) *
3879 (nritems
- slot
- nr
));
3881 btrfs_set_header_nritems(leaf
, nritems
- nr
);
3884 /* delete the leaf if we've emptied it */
3886 if (leaf
== root
->node
) {
3887 btrfs_set_header_level(leaf
, 0);
3889 btrfs_set_path_blocking(path
);
3890 clean_tree_block(trans
, root
, leaf
);
3891 ret
= btrfs_del_leaf(trans
, root
, path
, leaf
);
3895 int used
= leaf_space_used(leaf
, 0, nritems
);
3897 struct btrfs_disk_key disk_key
;
3899 btrfs_item_key(leaf
, &disk_key
, 0);
3900 wret
= fixup_low_keys(trans
, root
, path
,
3906 /* delete the leaf if it is mostly empty */
3907 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
3908 /* push_leaf_left fixes the path.
3909 * make sure the path still points to our leaf
3910 * for possible call to del_ptr below
3912 slot
= path
->slots
[1];
3913 extent_buffer_get(leaf
);
3915 btrfs_set_path_blocking(path
);
3916 wret
= push_leaf_left(trans
, root
, path
, 1, 1,
3918 if (wret
< 0 && wret
!= -ENOSPC
)
3921 if (path
->nodes
[0] == leaf
&&
3922 btrfs_header_nritems(leaf
)) {
3923 wret
= push_leaf_right(trans
, root
, path
, 1,
3925 if (wret
< 0 && wret
!= -ENOSPC
)
3929 if (btrfs_header_nritems(leaf
) == 0) {
3930 path
->slots
[1] = slot
;
3931 ret
= btrfs_del_leaf(trans
, root
, path
, leaf
);
3933 free_extent_buffer(leaf
);
3935 /* if we're still in the path, make sure
3936 * we're dirty. Otherwise, one of the
3937 * push_leaf functions must have already
3938 * dirtied this buffer
3940 if (path
->nodes
[0] == leaf
)
3941 btrfs_mark_buffer_dirty(leaf
);
3942 free_extent_buffer(leaf
);
3945 btrfs_mark_buffer_dirty(leaf
);
3952 * search the tree again to find a leaf with lesser keys
3953 * returns 0 if it found something or 1 if there are no lesser leaves.
3954 * returns < 0 on io errors.
3956 * This may release the path, and so you may lose any locks held at the
3959 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
3961 struct btrfs_key key
;
3962 struct btrfs_disk_key found_key
;
3965 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, 0);
3969 else if (key
.type
> 0)
3971 else if (key
.objectid
> 0)
3976 btrfs_release_path(path
);
3977 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3980 btrfs_item_key(path
->nodes
[0], &found_key
, 0);
3981 ret
= comp_keys(&found_key
, &key
);
3988 * A helper function to walk down the tree starting at min_key, and looking
3989 * for nodes or leaves that are either in cache or have a minimum
3990 * transaction id. This is used by the btree defrag code, and tree logging
3992 * This does not cow, but it does stuff the starting key it finds back
3993 * into min_key, so you can call btrfs_search_slot with cow=1 on the
3994 * key and get a writable path.
3996 * This does lock as it descends, and path->keep_locks should be set
3997 * to 1 by the caller.
3999 * This honors path->lowest_level to prevent descent past a given level
4002 * min_trans indicates the oldest transaction that you are interested
4003 * in walking through. Any nodes or leaves older than min_trans are
4004 * skipped over (without reading them).
4006 * returns zero if something useful was found, < 0 on error and 1 if there
4007 * was nothing in the tree that matched the search criteria.
4009 int btrfs_search_forward(struct btrfs_root
*root
, struct btrfs_key
*min_key
,
4010 struct btrfs_key
*max_key
,
4011 struct btrfs_path
*path
, int cache_only
,
4014 struct extent_buffer
*cur
;
4015 struct btrfs_key found_key
;
4022 WARN_ON(!path
->keep_locks
);
4024 cur
= btrfs_read_lock_root_node(root
);
4025 level
= btrfs_header_level(cur
);
4026 WARN_ON(path
->nodes
[level
]);
4027 path
->nodes
[level
] = cur
;
4028 path
->locks
[level
] = BTRFS_READ_LOCK
;
4030 if (btrfs_header_generation(cur
) < min_trans
) {
4035 nritems
= btrfs_header_nritems(cur
);
4036 level
= btrfs_header_level(cur
);
4037 sret
= bin_search(cur
, min_key
, level
, &slot
);
4039 /* at the lowest level, we're done, setup the path and exit */
4040 if (level
== path
->lowest_level
) {
4041 if (slot
>= nritems
)
4044 path
->slots
[level
] = slot
;
4045 btrfs_item_key_to_cpu(cur
, &found_key
, slot
);
4048 if (sret
&& slot
> 0)
4051 * check this node pointer against the cache_only and
4052 * min_trans parameters. If it isn't in cache or is too
4053 * old, skip to the next one.
4055 while (slot
< nritems
) {
4058 struct extent_buffer
*tmp
;
4059 struct btrfs_disk_key disk_key
;
4061 blockptr
= btrfs_node_blockptr(cur
, slot
);
4062 gen
= btrfs_node_ptr_generation(cur
, slot
);
4063 if (gen
< min_trans
) {
4071 btrfs_node_key(cur
, &disk_key
, slot
);
4072 if (comp_keys(&disk_key
, max_key
) >= 0) {
4078 tmp
= btrfs_find_tree_block(root
, blockptr
,
4079 btrfs_level_size(root
, level
- 1));
4081 if (tmp
&& btrfs_buffer_uptodate(tmp
, gen
)) {
4082 free_extent_buffer(tmp
);
4086 free_extent_buffer(tmp
);
4091 * we didn't find a candidate key in this node, walk forward
4092 * and find another one
4094 if (slot
>= nritems
) {
4095 path
->slots
[level
] = slot
;
4096 btrfs_set_path_blocking(path
);
4097 sret
= btrfs_find_next_key(root
, path
, min_key
, level
,
4098 cache_only
, min_trans
);
4100 btrfs_release_path(path
);
4106 /* save our key for returning back */
4107 btrfs_node_key_to_cpu(cur
, &found_key
, slot
);
4108 path
->slots
[level
] = slot
;
4109 if (level
== path
->lowest_level
) {
4111 unlock_up(path
, level
, 1);
4114 btrfs_set_path_blocking(path
);
4115 cur
= read_node_slot(root
, cur
, slot
);
4118 btrfs_tree_read_lock(cur
);
4120 path
->locks
[level
- 1] = BTRFS_READ_LOCK
;
4121 path
->nodes
[level
- 1] = cur
;
4122 unlock_up(path
, level
, 1);
4123 btrfs_clear_path_blocking(path
, NULL
, 0);
4127 memcpy(min_key
, &found_key
, sizeof(found_key
));
4128 btrfs_set_path_blocking(path
);
4133 * this is similar to btrfs_next_leaf, but does not try to preserve
4134 * and fixup the path. It looks for and returns the next key in the
4135 * tree based on the current path and the cache_only and min_trans
4138 * 0 is returned if another key is found, < 0 if there are any errors
4139 * and 1 is returned if there are no higher keys in the tree
4141 * path->keep_locks should be set to 1 on the search made before
4142 * calling this function.
4144 int btrfs_find_next_key(struct btrfs_root
*root
, struct btrfs_path
*path
,
4145 struct btrfs_key
*key
, int level
,
4146 int cache_only
, u64 min_trans
)
4149 struct extent_buffer
*c
;
4151 WARN_ON(!path
->keep_locks
);
4152 while (level
< BTRFS_MAX_LEVEL
) {
4153 if (!path
->nodes
[level
])
4156 slot
= path
->slots
[level
] + 1;
4157 c
= path
->nodes
[level
];
4159 if (slot
>= btrfs_header_nritems(c
)) {
4162 struct btrfs_key cur_key
;
4163 if (level
+ 1 >= BTRFS_MAX_LEVEL
||
4164 !path
->nodes
[level
+ 1])
4167 if (path
->locks
[level
+ 1]) {
4172 slot
= btrfs_header_nritems(c
) - 1;
4174 btrfs_item_key_to_cpu(c
, &cur_key
, slot
);
4176 btrfs_node_key_to_cpu(c
, &cur_key
, slot
);
4178 orig_lowest
= path
->lowest_level
;
4179 btrfs_release_path(path
);
4180 path
->lowest_level
= level
;
4181 ret
= btrfs_search_slot(NULL
, root
, &cur_key
, path
,
4183 path
->lowest_level
= orig_lowest
;
4187 c
= path
->nodes
[level
];
4188 slot
= path
->slots
[level
];
4195 btrfs_item_key_to_cpu(c
, key
, slot
);
4197 u64 blockptr
= btrfs_node_blockptr(c
, slot
);
4198 u64 gen
= btrfs_node_ptr_generation(c
, slot
);
4201 struct extent_buffer
*cur
;
4202 cur
= btrfs_find_tree_block(root
, blockptr
,
4203 btrfs_level_size(root
, level
- 1));
4204 if (!cur
|| !btrfs_buffer_uptodate(cur
, gen
)) {
4207 free_extent_buffer(cur
);
4210 free_extent_buffer(cur
);
4212 if (gen
< min_trans
) {
4216 btrfs_node_key_to_cpu(c
, key
, slot
);
4224 * search the tree again to find a leaf with greater keys
4225 * returns 0 if it found something or 1 if there are no greater leaves.
4226 * returns < 0 on io errors.
4228 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
4232 struct extent_buffer
*c
;
4233 struct extent_buffer
*next
;
4234 struct btrfs_key key
;
4237 int old_spinning
= path
->leave_spinning
;
4238 int next_rw_lock
= 0;
4240 nritems
= btrfs_header_nritems(path
->nodes
[0]);
4244 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, nritems
- 1);
4249 btrfs_release_path(path
);
4251 path
->keep_locks
= 1;
4252 path
->leave_spinning
= 1;
4254 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
4255 path
->keep_locks
= 0;
4260 nritems
= btrfs_header_nritems(path
->nodes
[0]);
4262 * by releasing the path above we dropped all our locks. A balance
4263 * could have added more items next to the key that used to be
4264 * at the very end of the block. So, check again here and
4265 * advance the path if there are now more items available.
4267 if (nritems
> 0 && path
->slots
[0] < nritems
- 1) {
4274 while (level
< BTRFS_MAX_LEVEL
) {
4275 if (!path
->nodes
[level
]) {
4280 slot
= path
->slots
[level
] + 1;
4281 c
= path
->nodes
[level
];
4282 if (slot
>= btrfs_header_nritems(c
)) {
4284 if (level
== BTRFS_MAX_LEVEL
) {
4292 btrfs_tree_unlock_rw(next
, next_rw_lock
);
4293 free_extent_buffer(next
);
4297 next_rw_lock
= path
->locks
[level
];
4298 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
4304 btrfs_release_path(path
);
4308 if (!path
->skip_locking
) {
4309 ret
= btrfs_try_tree_read_lock(next
);
4311 btrfs_set_path_blocking(path
);
4312 btrfs_tree_read_lock(next
);
4313 btrfs_clear_path_blocking(path
, next
,
4316 next_rw_lock
= BTRFS_READ_LOCK
;
4320 path
->slots
[level
] = slot
;
4323 c
= path
->nodes
[level
];
4324 if (path
->locks
[level
])
4325 btrfs_tree_unlock_rw(c
, path
->locks
[level
]);
4327 free_extent_buffer(c
);
4328 path
->nodes
[level
] = next
;
4329 path
->slots
[level
] = 0;
4330 if (!path
->skip_locking
)
4331 path
->locks
[level
] = next_rw_lock
;
4335 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
4341 btrfs_release_path(path
);
4345 if (!path
->skip_locking
) {
4346 ret
= btrfs_try_tree_read_lock(next
);
4348 btrfs_set_path_blocking(path
);
4349 btrfs_tree_read_lock(next
);
4350 btrfs_clear_path_blocking(path
, next
,
4353 next_rw_lock
= BTRFS_READ_LOCK
;
4358 unlock_up(path
, 0, 1);
4359 path
->leave_spinning
= old_spinning
;
4361 btrfs_set_path_blocking(path
);
4367 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
4368 * searching until it gets past min_objectid or finds an item of 'type'
4370 * returns 0 if something is found, 1 if nothing was found and < 0 on error
4372 int btrfs_previous_item(struct btrfs_root
*root
,
4373 struct btrfs_path
*path
, u64 min_objectid
,
4376 struct btrfs_key found_key
;
4377 struct extent_buffer
*leaf
;
4382 if (path
->slots
[0] == 0) {
4383 btrfs_set_path_blocking(path
);
4384 ret
= btrfs_prev_leaf(root
, path
);
4390 leaf
= path
->nodes
[0];
4391 nritems
= btrfs_header_nritems(leaf
);
4394 if (path
->slots
[0] == nritems
)
4397 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
4398 if (found_key
.objectid
< min_objectid
)
4400 if (found_key
.type
== type
)
4402 if (found_key
.objectid
== min_objectid
&&
4403 found_key
.type
< type
)