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>
21 #include <linux/rbtree.h>
24 #include "transaction.h"
25 #include "print-tree.h"
28 static int split_node(struct btrfs_trans_handle
*trans
, struct btrfs_root
29 *root
, struct btrfs_path
*path
, int level
);
30 static int split_leaf(struct btrfs_trans_handle
*trans
, struct btrfs_root
31 *root
, struct btrfs_key
*ins_key
,
32 struct btrfs_path
*path
, int data_size
, int extend
);
33 static int push_node_left(struct btrfs_trans_handle
*trans
,
34 struct btrfs_root
*root
, struct extent_buffer
*dst
,
35 struct extent_buffer
*src
, int empty
);
36 static int balance_node_right(struct btrfs_trans_handle
*trans
,
37 struct btrfs_root
*root
,
38 struct extent_buffer
*dst_buf
,
39 struct extent_buffer
*src_buf
);
40 static void del_ptr(struct btrfs_root
*root
, struct btrfs_path
*path
,
42 static void tree_mod_log_free_eb(struct btrfs_fs_info
*fs_info
,
43 struct extent_buffer
*eb
);
44 static int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
);
46 struct btrfs_path
*btrfs_alloc_path(void)
48 struct btrfs_path
*path
;
49 path
= kmem_cache_zalloc(btrfs_path_cachep
, GFP_NOFS
);
54 * set all locked nodes in the path to blocking locks. This should
55 * be done before scheduling
57 noinline
void btrfs_set_path_blocking(struct btrfs_path
*p
)
60 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
61 if (!p
->nodes
[i
] || !p
->locks
[i
])
63 btrfs_set_lock_blocking_rw(p
->nodes
[i
], p
->locks
[i
]);
64 if (p
->locks
[i
] == BTRFS_READ_LOCK
)
65 p
->locks
[i
] = BTRFS_READ_LOCK_BLOCKING
;
66 else if (p
->locks
[i
] == BTRFS_WRITE_LOCK
)
67 p
->locks
[i
] = BTRFS_WRITE_LOCK_BLOCKING
;
72 * reset all the locked nodes in the patch to spinning locks.
74 * held is used to keep lockdep happy, when lockdep is enabled
75 * we set held to a blocking lock before we go around and
76 * retake all the spinlocks in the path. You can safely use NULL
79 noinline
void btrfs_clear_path_blocking(struct btrfs_path
*p
,
80 struct extent_buffer
*held
, int held_rw
)
84 #ifdef CONFIG_DEBUG_LOCK_ALLOC
85 /* lockdep really cares that we take all of these spinlocks
86 * in the right order. If any of the locks in the path are not
87 * currently blocking, it is going to complain. So, make really
88 * really sure by forcing the path to blocking before we clear
92 btrfs_set_lock_blocking_rw(held
, held_rw
);
93 if (held_rw
== BTRFS_WRITE_LOCK
)
94 held_rw
= BTRFS_WRITE_LOCK_BLOCKING
;
95 else if (held_rw
== BTRFS_READ_LOCK
)
96 held_rw
= BTRFS_READ_LOCK_BLOCKING
;
98 btrfs_set_path_blocking(p
);
101 for (i
= BTRFS_MAX_LEVEL
- 1; i
>= 0; i
--) {
102 if (p
->nodes
[i
] && p
->locks
[i
]) {
103 btrfs_clear_lock_blocking_rw(p
->nodes
[i
], p
->locks
[i
]);
104 if (p
->locks
[i
] == BTRFS_WRITE_LOCK_BLOCKING
)
105 p
->locks
[i
] = BTRFS_WRITE_LOCK
;
106 else if (p
->locks
[i
] == BTRFS_READ_LOCK_BLOCKING
)
107 p
->locks
[i
] = BTRFS_READ_LOCK
;
111 #ifdef CONFIG_DEBUG_LOCK_ALLOC
113 btrfs_clear_lock_blocking_rw(held
, held_rw
);
117 /* this also releases the path */
118 void btrfs_free_path(struct btrfs_path
*p
)
122 btrfs_release_path(p
);
123 kmem_cache_free(btrfs_path_cachep
, p
);
127 * path release drops references on the extent buffers in the path
128 * and it drops any locks held by this path
130 * It is safe to call this on paths that no locks or extent buffers held.
132 noinline
void btrfs_release_path(struct btrfs_path
*p
)
136 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++) {
141 btrfs_tree_unlock_rw(p
->nodes
[i
], p
->locks
[i
]);
144 free_extent_buffer(p
->nodes
[i
]);
150 * safely gets a reference on the root node of a tree. A lock
151 * is not taken, so a concurrent writer may put a different node
152 * at the root of the tree. See btrfs_lock_root_node for the
155 * The extent buffer returned by this has a reference taken, so
156 * it won't disappear. It may stop being the root of the tree
157 * at any time because there are no locks held.
159 struct extent_buffer
*btrfs_root_node(struct btrfs_root
*root
)
161 struct extent_buffer
*eb
;
165 eb
= rcu_dereference(root
->node
);
168 * RCU really hurts here, we could free up the root node because
169 * it was cow'ed but we may not get the new root node yet so do
170 * the inc_not_zero dance and if it doesn't work then
171 * synchronize_rcu and try again.
173 if (atomic_inc_not_zero(&eb
->refs
)) {
183 /* loop around taking references on and locking the root node of the
184 * tree until you end up with a lock on the root. A locked buffer
185 * is returned, with a reference held.
187 struct extent_buffer
*btrfs_lock_root_node(struct btrfs_root
*root
)
189 struct extent_buffer
*eb
;
192 eb
= btrfs_root_node(root
);
194 if (eb
== root
->node
)
196 btrfs_tree_unlock(eb
);
197 free_extent_buffer(eb
);
202 /* loop around taking references on and locking the root node of the
203 * tree until you end up with a lock on the root. A locked buffer
204 * is returned, with a reference held.
206 static struct extent_buffer
*btrfs_read_lock_root_node(struct btrfs_root
*root
)
208 struct extent_buffer
*eb
;
211 eb
= btrfs_root_node(root
);
212 btrfs_tree_read_lock(eb
);
213 if (eb
== root
->node
)
215 btrfs_tree_read_unlock(eb
);
216 free_extent_buffer(eb
);
221 /* cowonly root (everything not a reference counted cow subvolume), just get
222 * put onto a simple dirty list. transaction.c walks this to make sure they
223 * get properly updated on disk.
225 static void add_root_to_dirty_list(struct btrfs_root
*root
)
227 spin_lock(&root
->fs_info
->trans_lock
);
228 if (root
->track_dirty
&& list_empty(&root
->dirty_list
)) {
229 list_add(&root
->dirty_list
,
230 &root
->fs_info
->dirty_cowonly_roots
);
232 spin_unlock(&root
->fs_info
->trans_lock
);
236 * used by snapshot creation to make a copy of a root for a tree with
237 * a given objectid. The buffer with the new root node is returned in
238 * cow_ret, and this func returns zero on success or a negative error code.
240 int btrfs_copy_root(struct btrfs_trans_handle
*trans
,
241 struct btrfs_root
*root
,
242 struct extent_buffer
*buf
,
243 struct extent_buffer
**cow_ret
, u64 new_root_objectid
)
245 struct extent_buffer
*cow
;
248 struct btrfs_disk_key disk_key
;
250 WARN_ON(root
->ref_cows
&& trans
->transid
!=
251 root
->fs_info
->running_transaction
->transid
);
252 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
254 level
= btrfs_header_level(buf
);
256 btrfs_item_key(buf
, &disk_key
, 0);
258 btrfs_node_key(buf
, &disk_key
, 0);
260 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, 0,
261 new_root_objectid
, &disk_key
, level
,
266 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
267 btrfs_set_header_bytenr(cow
, cow
->start
);
268 btrfs_set_header_generation(cow
, trans
->transid
);
269 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
270 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
271 BTRFS_HEADER_FLAG_RELOC
);
272 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
273 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
275 btrfs_set_header_owner(cow
, new_root_objectid
);
277 write_extent_buffer(cow
, root
->fs_info
->fsid
,
278 (unsigned long)btrfs_header_fsid(cow
),
281 WARN_ON(btrfs_header_generation(buf
) > trans
->transid
);
282 if (new_root_objectid
== BTRFS_TREE_RELOC_OBJECTID
)
283 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
285 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
290 btrfs_mark_buffer_dirty(cow
);
299 MOD_LOG_KEY_REMOVE_WHILE_FREEING
,
300 MOD_LOG_KEY_REMOVE_WHILE_MOVING
,
302 MOD_LOG_ROOT_REPLACE
,
305 struct tree_mod_move
{
310 struct tree_mod_root
{
315 struct tree_mod_elem
{
317 u64 index
; /* shifted logical */
321 /* this is used for MOD_LOG_KEY_* and MOD_LOG_MOVE_KEYS operations */
324 /* this is used for MOD_LOG_KEY* and MOD_LOG_ROOT_REPLACE */
327 /* those are used for op == MOD_LOG_KEY_{REPLACE,REMOVE} */
328 struct btrfs_disk_key key
;
331 /* this is used for op == MOD_LOG_MOVE_KEYS */
332 struct tree_mod_move move
;
334 /* this is used for op == MOD_LOG_ROOT_REPLACE */
335 struct tree_mod_root old_root
;
338 static inline void tree_mod_log_read_lock(struct btrfs_fs_info
*fs_info
)
340 read_lock(&fs_info
->tree_mod_log_lock
);
343 static inline void tree_mod_log_read_unlock(struct btrfs_fs_info
*fs_info
)
345 read_unlock(&fs_info
->tree_mod_log_lock
);
348 static inline void tree_mod_log_write_lock(struct btrfs_fs_info
*fs_info
)
350 write_lock(&fs_info
->tree_mod_log_lock
);
353 static inline void tree_mod_log_write_unlock(struct btrfs_fs_info
*fs_info
)
355 write_unlock(&fs_info
->tree_mod_log_lock
);
359 * Increment the upper half of tree_mod_seq, set lower half zero.
361 * Must be called with fs_info->tree_mod_seq_lock held.
363 static inline u64
btrfs_inc_tree_mod_seq_major(struct btrfs_fs_info
*fs_info
)
365 u64 seq
= atomic64_read(&fs_info
->tree_mod_seq
);
366 seq
&= 0xffffffff00000000ull
;
368 atomic64_set(&fs_info
->tree_mod_seq
, seq
);
373 * Increment the lower half of tree_mod_seq.
375 * Must be called with fs_info->tree_mod_seq_lock held. The way major numbers
376 * are generated should not technically require a spin lock here. (Rationale:
377 * incrementing the minor while incrementing the major seq number is between its
378 * atomic64_read and atomic64_set calls doesn't duplicate sequence numbers, it
379 * just returns a unique sequence number as usual.) We have decided to leave
380 * that requirement in here and rethink it once we notice it really imposes a
381 * problem on some workload.
383 static inline u64
btrfs_inc_tree_mod_seq_minor(struct btrfs_fs_info
*fs_info
)
385 return atomic64_inc_return(&fs_info
->tree_mod_seq
);
389 * return the last minor in the previous major tree_mod_seq number
391 u64
btrfs_tree_mod_seq_prev(u64 seq
)
393 return (seq
& 0xffffffff00000000ull
) - 1ull;
397 * This adds a new blocker to the tree mod log's blocker list if the @elem
398 * passed does not already have a sequence number set. So when a caller expects
399 * to record tree modifications, it should ensure to set elem->seq to zero
400 * before calling btrfs_get_tree_mod_seq.
401 * Returns a fresh, unused tree log modification sequence number, even if no new
404 u64
btrfs_get_tree_mod_seq(struct btrfs_fs_info
*fs_info
,
405 struct seq_list
*elem
)
409 tree_mod_log_write_lock(fs_info
);
410 spin_lock(&fs_info
->tree_mod_seq_lock
);
412 elem
->seq
= btrfs_inc_tree_mod_seq_major(fs_info
);
413 list_add_tail(&elem
->list
, &fs_info
->tree_mod_seq_list
);
415 seq
= btrfs_inc_tree_mod_seq_minor(fs_info
);
416 spin_unlock(&fs_info
->tree_mod_seq_lock
);
417 tree_mod_log_write_unlock(fs_info
);
422 void btrfs_put_tree_mod_seq(struct btrfs_fs_info
*fs_info
,
423 struct seq_list
*elem
)
425 struct rb_root
*tm_root
;
426 struct rb_node
*node
;
427 struct rb_node
*next
;
428 struct seq_list
*cur_elem
;
429 struct tree_mod_elem
*tm
;
430 u64 min_seq
= (u64
)-1;
431 u64 seq_putting
= elem
->seq
;
436 spin_lock(&fs_info
->tree_mod_seq_lock
);
437 list_del(&elem
->list
);
440 list_for_each_entry(cur_elem
, &fs_info
->tree_mod_seq_list
, list
) {
441 if (cur_elem
->seq
< min_seq
) {
442 if (seq_putting
> cur_elem
->seq
) {
444 * blocker with lower sequence number exists, we
445 * cannot remove anything from the log
447 spin_unlock(&fs_info
->tree_mod_seq_lock
);
450 min_seq
= cur_elem
->seq
;
453 spin_unlock(&fs_info
->tree_mod_seq_lock
);
456 * anything that's lower than the lowest existing (read: blocked)
457 * sequence number can be removed from the tree.
459 tree_mod_log_write_lock(fs_info
);
460 tm_root
= &fs_info
->tree_mod_log
;
461 for (node
= rb_first(tm_root
); node
; node
= next
) {
462 next
= rb_next(node
);
463 tm
= container_of(node
, struct tree_mod_elem
, node
);
464 if (tm
->seq
> min_seq
)
466 rb_erase(node
, tm_root
);
469 tree_mod_log_write_unlock(fs_info
);
473 * key order of the log:
476 * the index is the shifted logical of the *new* root node for root replace
477 * operations, or the shifted logical of the affected block for all other
481 __tree_mod_log_insert(struct btrfs_fs_info
*fs_info
, struct tree_mod_elem
*tm
)
483 struct rb_root
*tm_root
;
484 struct rb_node
**new;
485 struct rb_node
*parent
= NULL
;
486 struct tree_mod_elem
*cur
;
488 BUG_ON(!tm
|| !tm
->seq
);
490 tm_root
= &fs_info
->tree_mod_log
;
491 new = &tm_root
->rb_node
;
493 cur
= container_of(*new, struct tree_mod_elem
, node
);
495 if (cur
->index
< tm
->index
)
496 new = &((*new)->rb_left
);
497 else if (cur
->index
> tm
->index
)
498 new = &((*new)->rb_right
);
499 else if (cur
->seq
< tm
->seq
)
500 new = &((*new)->rb_left
);
501 else if (cur
->seq
> tm
->seq
)
502 new = &((*new)->rb_right
);
509 rb_link_node(&tm
->node
, parent
, new);
510 rb_insert_color(&tm
->node
, tm_root
);
515 * Determines if logging can be omitted. Returns 1 if it can. Otherwise, it
516 * returns zero with the tree_mod_log_lock acquired. The caller must hold
517 * this until all tree mod log insertions are recorded in the rb tree and then
518 * call tree_mod_log_write_unlock() to release.
520 static inline int tree_mod_dont_log(struct btrfs_fs_info
*fs_info
,
521 struct extent_buffer
*eb
) {
523 if (list_empty(&(fs_info
)->tree_mod_seq_list
))
525 if (eb
&& btrfs_header_level(eb
) == 0)
528 tree_mod_log_write_lock(fs_info
);
529 if (list_empty(&fs_info
->tree_mod_seq_list
)) {
531 * someone emptied the list while we were waiting for the lock.
532 * we must not add to the list when no blocker exists.
534 tree_mod_log_write_unlock(fs_info
);
542 * This allocates memory and gets a tree modification sequence number.
544 * Returns <0 on error.
545 * Returns >0 (the added sequence number) on success.
547 static inline int tree_mod_alloc(struct btrfs_fs_info
*fs_info
, gfp_t flags
,
548 struct tree_mod_elem
**tm_ret
)
550 struct tree_mod_elem
*tm
;
553 * once we switch from spin locks to something different, we should
554 * honor the flags parameter here.
556 tm
= *tm_ret
= kzalloc(sizeof(*tm
), GFP_ATOMIC
);
560 spin_lock(&fs_info
->tree_mod_seq_lock
);
561 tm
->seq
= btrfs_inc_tree_mod_seq_minor(fs_info
);
562 spin_unlock(&fs_info
->tree_mod_seq_lock
);
568 __tree_mod_log_insert_key(struct btrfs_fs_info
*fs_info
,
569 struct extent_buffer
*eb
, int slot
,
570 enum mod_log_op op
, gfp_t flags
)
573 struct tree_mod_elem
*tm
;
575 ret
= tree_mod_alloc(fs_info
, flags
, &tm
);
579 tm
->index
= eb
->start
>> PAGE_CACHE_SHIFT
;
580 if (op
!= MOD_LOG_KEY_ADD
) {
581 btrfs_node_key(eb
, &tm
->key
, slot
);
582 tm
->blockptr
= btrfs_node_blockptr(eb
, slot
);
586 tm
->generation
= btrfs_node_ptr_generation(eb
, slot
);
588 return __tree_mod_log_insert(fs_info
, tm
);
592 tree_mod_log_insert_key_mask(struct btrfs_fs_info
*fs_info
,
593 struct extent_buffer
*eb
, int slot
,
594 enum mod_log_op op
, gfp_t flags
)
598 if (tree_mod_dont_log(fs_info
, eb
))
601 ret
= __tree_mod_log_insert_key(fs_info
, eb
, slot
, op
, flags
);
603 tree_mod_log_write_unlock(fs_info
);
608 tree_mod_log_insert_key(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
,
609 int slot
, enum mod_log_op op
)
611 return tree_mod_log_insert_key_mask(fs_info
, eb
, slot
, op
, GFP_NOFS
);
615 tree_mod_log_insert_key_locked(struct btrfs_fs_info
*fs_info
,
616 struct extent_buffer
*eb
, int slot
,
619 return __tree_mod_log_insert_key(fs_info
, eb
, slot
, op
, GFP_NOFS
);
623 tree_mod_log_insert_move(struct btrfs_fs_info
*fs_info
,
624 struct extent_buffer
*eb
, int dst_slot
, int src_slot
,
625 int nr_items
, gfp_t flags
)
627 struct tree_mod_elem
*tm
;
631 if (tree_mod_dont_log(fs_info
, eb
))
635 * When we override something during the move, we log these removals.
636 * This can only happen when we move towards the beginning of the
637 * buffer, i.e. dst_slot < src_slot.
639 for (i
= 0; i
+ dst_slot
< src_slot
&& i
< nr_items
; i
++) {
640 ret
= tree_mod_log_insert_key_locked(fs_info
, eb
, i
+ dst_slot
,
641 MOD_LOG_KEY_REMOVE_WHILE_MOVING
);
645 ret
= tree_mod_alloc(fs_info
, flags
, &tm
);
649 tm
->index
= eb
->start
>> PAGE_CACHE_SHIFT
;
651 tm
->move
.dst_slot
= dst_slot
;
652 tm
->move
.nr_items
= nr_items
;
653 tm
->op
= MOD_LOG_MOVE_KEYS
;
655 ret
= __tree_mod_log_insert(fs_info
, tm
);
657 tree_mod_log_write_unlock(fs_info
);
662 __tree_mod_log_free_eb(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
)
668 if (btrfs_header_level(eb
) == 0)
671 nritems
= btrfs_header_nritems(eb
);
672 for (i
= nritems
- 1; i
>= 0; i
--) {
673 ret
= tree_mod_log_insert_key_locked(fs_info
, eb
, i
,
674 MOD_LOG_KEY_REMOVE_WHILE_FREEING
);
680 tree_mod_log_insert_root(struct btrfs_fs_info
*fs_info
,
681 struct extent_buffer
*old_root
,
682 struct extent_buffer
*new_root
, gfp_t flags
,
685 struct tree_mod_elem
*tm
;
688 if (tree_mod_dont_log(fs_info
, NULL
))
692 __tree_mod_log_free_eb(fs_info
, old_root
);
694 ret
= tree_mod_alloc(fs_info
, flags
, &tm
);
698 tm
->index
= new_root
->start
>> PAGE_CACHE_SHIFT
;
699 tm
->old_root
.logical
= old_root
->start
;
700 tm
->old_root
.level
= btrfs_header_level(old_root
);
701 tm
->generation
= btrfs_header_generation(old_root
);
702 tm
->op
= MOD_LOG_ROOT_REPLACE
;
704 ret
= __tree_mod_log_insert(fs_info
, tm
);
706 tree_mod_log_write_unlock(fs_info
);
710 static struct tree_mod_elem
*
711 __tree_mod_log_search(struct btrfs_fs_info
*fs_info
, u64 start
, u64 min_seq
,
714 struct rb_root
*tm_root
;
715 struct rb_node
*node
;
716 struct tree_mod_elem
*cur
= NULL
;
717 struct tree_mod_elem
*found
= NULL
;
718 u64 index
= start
>> PAGE_CACHE_SHIFT
;
720 tree_mod_log_read_lock(fs_info
);
721 tm_root
= &fs_info
->tree_mod_log
;
722 node
= tm_root
->rb_node
;
724 cur
= container_of(node
, struct tree_mod_elem
, node
);
725 if (cur
->index
< index
) {
726 node
= node
->rb_left
;
727 } else if (cur
->index
> index
) {
728 node
= node
->rb_right
;
729 } else if (cur
->seq
< min_seq
) {
730 node
= node
->rb_left
;
731 } else if (!smallest
) {
732 /* we want the node with the highest seq */
734 BUG_ON(found
->seq
> cur
->seq
);
736 node
= node
->rb_left
;
737 } else if (cur
->seq
> min_seq
) {
738 /* we want the node with the smallest seq */
740 BUG_ON(found
->seq
< cur
->seq
);
742 node
= node
->rb_right
;
748 tree_mod_log_read_unlock(fs_info
);
754 * this returns the element from the log with the smallest time sequence
755 * value that's in the log (the oldest log item). any element with a time
756 * sequence lower than min_seq will be ignored.
758 static struct tree_mod_elem
*
759 tree_mod_log_search_oldest(struct btrfs_fs_info
*fs_info
, u64 start
,
762 return __tree_mod_log_search(fs_info
, start
, min_seq
, 1);
766 * this returns the element from the log with the largest time sequence
767 * value that's in the log (the most recent log item). any element with
768 * a time sequence lower than min_seq will be ignored.
770 static struct tree_mod_elem
*
771 tree_mod_log_search(struct btrfs_fs_info
*fs_info
, u64 start
, u64 min_seq
)
773 return __tree_mod_log_search(fs_info
, start
, min_seq
, 0);
777 tree_mod_log_eb_copy(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*dst
,
778 struct extent_buffer
*src
, unsigned long dst_offset
,
779 unsigned long src_offset
, int nr_items
)
784 if (tree_mod_dont_log(fs_info
, NULL
))
787 if (btrfs_header_level(dst
) == 0 && btrfs_header_level(src
) == 0) {
788 tree_mod_log_write_unlock(fs_info
);
792 for (i
= 0; i
< nr_items
; i
++) {
793 ret
= tree_mod_log_insert_key_locked(fs_info
, src
,
797 ret
= tree_mod_log_insert_key_locked(fs_info
, dst
,
803 tree_mod_log_write_unlock(fs_info
);
807 tree_mod_log_eb_move(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*dst
,
808 int dst_offset
, int src_offset
, int nr_items
)
811 ret
= tree_mod_log_insert_move(fs_info
, dst
, dst_offset
, src_offset
,
817 tree_mod_log_set_node_key(struct btrfs_fs_info
*fs_info
,
818 struct extent_buffer
*eb
, int slot
, int atomic
)
822 ret
= tree_mod_log_insert_key_mask(fs_info
, eb
, slot
,
824 atomic
? GFP_ATOMIC
: GFP_NOFS
);
829 tree_mod_log_free_eb(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
)
831 if (tree_mod_dont_log(fs_info
, eb
))
834 __tree_mod_log_free_eb(fs_info
, eb
);
836 tree_mod_log_write_unlock(fs_info
);
840 tree_mod_log_set_root_pointer(struct btrfs_root
*root
,
841 struct extent_buffer
*new_root_node
,
845 ret
= tree_mod_log_insert_root(root
->fs_info
, root
->node
,
846 new_root_node
, GFP_NOFS
, log_removal
);
851 * check if the tree block can be shared by multiple trees
853 int btrfs_block_can_be_shared(struct btrfs_root
*root
,
854 struct extent_buffer
*buf
)
857 * Tree blocks not in refernece counted trees and tree roots
858 * are never shared. If a block was allocated after the last
859 * snapshot and the block was not allocated by tree relocation,
860 * we know the block is not shared.
862 if (root
->ref_cows
&&
863 buf
!= root
->node
&& buf
!= root
->commit_root
&&
864 (btrfs_header_generation(buf
) <=
865 btrfs_root_last_snapshot(&root
->root_item
) ||
866 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)))
868 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
869 if (root
->ref_cows
&&
870 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
876 static noinline
int update_ref_for_cow(struct btrfs_trans_handle
*trans
,
877 struct btrfs_root
*root
,
878 struct extent_buffer
*buf
,
879 struct extent_buffer
*cow
,
889 * Backrefs update rules:
891 * Always use full backrefs for extent pointers in tree block
892 * allocated by tree relocation.
894 * If a shared tree block is no longer referenced by its owner
895 * tree (btrfs_header_owner(buf) == root->root_key.objectid),
896 * use full backrefs for extent pointers in tree block.
898 * If a tree block is been relocating
899 * (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID),
900 * use full backrefs for extent pointers in tree block.
901 * The reason for this is some operations (such as drop tree)
902 * are only allowed for blocks use full backrefs.
905 if (btrfs_block_can_be_shared(root
, buf
)) {
906 ret
= btrfs_lookup_extent_info(trans
, root
, buf
->start
,
907 btrfs_header_level(buf
), 1,
913 btrfs_std_error(root
->fs_info
, ret
);
918 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
919 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
920 flags
= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
925 owner
= btrfs_header_owner(buf
);
926 BUG_ON(owner
== BTRFS_TREE_RELOC_OBJECTID
&&
927 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
));
930 if ((owner
== root
->root_key
.objectid
||
931 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) &&
932 !(flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)) {
933 ret
= btrfs_inc_ref(trans
, root
, buf
, 1, 1);
934 BUG_ON(ret
); /* -ENOMEM */
936 if (root
->root_key
.objectid
==
937 BTRFS_TREE_RELOC_OBJECTID
) {
938 ret
= btrfs_dec_ref(trans
, root
, buf
, 0, 1);
939 BUG_ON(ret
); /* -ENOMEM */
940 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
941 BUG_ON(ret
); /* -ENOMEM */
943 new_flags
|= BTRFS_BLOCK_FLAG_FULL_BACKREF
;
946 if (root
->root_key
.objectid
==
947 BTRFS_TREE_RELOC_OBJECTID
)
948 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
950 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
951 BUG_ON(ret
); /* -ENOMEM */
953 if (new_flags
!= 0) {
954 int level
= btrfs_header_level(buf
);
956 ret
= btrfs_set_disk_extent_flags(trans
, root
,
959 new_flags
, level
, 0);
964 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
) {
965 if (root
->root_key
.objectid
==
966 BTRFS_TREE_RELOC_OBJECTID
)
967 ret
= btrfs_inc_ref(trans
, root
, cow
, 1, 1);
969 ret
= btrfs_inc_ref(trans
, root
, cow
, 0, 1);
970 BUG_ON(ret
); /* -ENOMEM */
971 ret
= btrfs_dec_ref(trans
, root
, buf
, 1, 1);
972 BUG_ON(ret
); /* -ENOMEM */
974 clean_tree_block(trans
, root
, buf
);
981 * does the dirty work in cow of a single block. The parent block (if
982 * supplied) is updated to point to the new cow copy. The new buffer is marked
983 * dirty and returned locked. If you modify the block it needs to be marked
986 * search_start -- an allocation hint for the new block
988 * empty_size -- a hint that you plan on doing more cow. This is the size in
989 * bytes the allocator should try to find free next to the block it returns.
990 * This is just a hint and may be ignored by the allocator.
992 static noinline
int __btrfs_cow_block(struct btrfs_trans_handle
*trans
,
993 struct btrfs_root
*root
,
994 struct extent_buffer
*buf
,
995 struct extent_buffer
*parent
, int parent_slot
,
996 struct extent_buffer
**cow_ret
,
997 u64 search_start
, u64 empty_size
)
999 struct btrfs_disk_key disk_key
;
1000 struct extent_buffer
*cow
;
1003 int unlock_orig
= 0;
1006 if (*cow_ret
== buf
)
1009 btrfs_assert_tree_locked(buf
);
1011 WARN_ON(root
->ref_cows
&& trans
->transid
!=
1012 root
->fs_info
->running_transaction
->transid
);
1013 WARN_ON(root
->ref_cows
&& trans
->transid
!= root
->last_trans
);
1015 level
= btrfs_header_level(buf
);
1018 btrfs_item_key(buf
, &disk_key
, 0);
1020 btrfs_node_key(buf
, &disk_key
, 0);
1022 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
1024 parent_start
= parent
->start
;
1030 cow
= btrfs_alloc_free_block(trans
, root
, buf
->len
, parent_start
,
1031 root
->root_key
.objectid
, &disk_key
,
1032 level
, search_start
, empty_size
);
1034 return PTR_ERR(cow
);
1036 /* cow is set to blocking by btrfs_init_new_buffer */
1038 copy_extent_buffer(cow
, buf
, 0, 0, cow
->len
);
1039 btrfs_set_header_bytenr(cow
, cow
->start
);
1040 btrfs_set_header_generation(cow
, trans
->transid
);
1041 btrfs_set_header_backref_rev(cow
, BTRFS_MIXED_BACKREF_REV
);
1042 btrfs_clear_header_flag(cow
, BTRFS_HEADER_FLAG_WRITTEN
|
1043 BTRFS_HEADER_FLAG_RELOC
);
1044 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1045 btrfs_set_header_flag(cow
, BTRFS_HEADER_FLAG_RELOC
);
1047 btrfs_set_header_owner(cow
, root
->root_key
.objectid
);
1049 write_extent_buffer(cow
, root
->fs_info
->fsid
,
1050 (unsigned long)btrfs_header_fsid(cow
),
1053 ret
= update_ref_for_cow(trans
, root
, buf
, cow
, &last_ref
);
1055 btrfs_abort_transaction(trans
, root
, ret
);
1060 btrfs_reloc_cow_block(trans
, root
, buf
, cow
);
1062 if (buf
== root
->node
) {
1063 WARN_ON(parent
&& parent
!= buf
);
1064 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
||
1065 btrfs_header_backref_rev(buf
) < BTRFS_MIXED_BACKREF_REV
)
1066 parent_start
= buf
->start
;
1070 extent_buffer_get(cow
);
1071 tree_mod_log_set_root_pointer(root
, cow
, 1);
1072 rcu_assign_pointer(root
->node
, cow
);
1074 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
1076 free_extent_buffer(buf
);
1077 add_root_to_dirty_list(root
);
1079 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1080 parent_start
= parent
->start
;
1084 WARN_ON(trans
->transid
!= btrfs_header_generation(parent
));
1085 tree_mod_log_insert_key(root
->fs_info
, parent
, parent_slot
,
1086 MOD_LOG_KEY_REPLACE
);
1087 btrfs_set_node_blockptr(parent
, parent_slot
,
1089 btrfs_set_node_ptr_generation(parent
, parent_slot
,
1091 btrfs_mark_buffer_dirty(parent
);
1093 tree_mod_log_free_eb(root
->fs_info
, buf
);
1094 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
1098 btrfs_tree_unlock(buf
);
1099 free_extent_buffer_stale(buf
);
1100 btrfs_mark_buffer_dirty(cow
);
1106 * returns the logical address of the oldest predecessor of the given root.
1107 * entries older than time_seq are ignored.
1109 static struct tree_mod_elem
*
1110 __tree_mod_log_oldest_root(struct btrfs_fs_info
*fs_info
,
1111 struct extent_buffer
*eb_root
, u64 time_seq
)
1113 struct tree_mod_elem
*tm
;
1114 struct tree_mod_elem
*found
= NULL
;
1115 u64 root_logical
= eb_root
->start
;
1122 * the very last operation that's logged for a root is the replacement
1123 * operation (if it is replaced at all). this has the index of the *new*
1124 * root, making it the very first operation that's logged for this root.
1127 tm
= tree_mod_log_search_oldest(fs_info
, root_logical
,
1132 * if there are no tree operation for the oldest root, we simply
1133 * return it. this should only happen if that (old) root is at
1140 * if there's an operation that's not a root replacement, we
1141 * found the oldest version of our root. normally, we'll find a
1142 * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here.
1144 if (tm
->op
!= MOD_LOG_ROOT_REPLACE
)
1148 root_logical
= tm
->old_root
.logical
;
1152 /* if there's no old root to return, return what we found instead */
1160 * tm is a pointer to the first operation to rewind within eb. then, all
1161 * previous operations will be rewinded (until we reach something older than
1165 __tree_mod_log_rewind(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
,
1166 u64 time_seq
, struct tree_mod_elem
*first_tm
)
1169 struct rb_node
*next
;
1170 struct tree_mod_elem
*tm
= first_tm
;
1171 unsigned long o_dst
;
1172 unsigned long o_src
;
1173 unsigned long p_size
= sizeof(struct btrfs_key_ptr
);
1175 n
= btrfs_header_nritems(eb
);
1176 tree_mod_log_read_lock(fs_info
);
1177 while (tm
&& tm
->seq
>= time_seq
) {
1179 * all the operations are recorded with the operator used for
1180 * the modification. as we're going backwards, we do the
1181 * opposite of each operation here.
1184 case MOD_LOG_KEY_REMOVE_WHILE_FREEING
:
1185 BUG_ON(tm
->slot
< n
);
1187 case MOD_LOG_KEY_REMOVE_WHILE_MOVING
:
1188 case MOD_LOG_KEY_REMOVE
:
1189 btrfs_set_node_key(eb
, &tm
->key
, tm
->slot
);
1190 btrfs_set_node_blockptr(eb
, tm
->slot
, tm
->blockptr
);
1191 btrfs_set_node_ptr_generation(eb
, tm
->slot
,
1195 case MOD_LOG_KEY_REPLACE
:
1196 BUG_ON(tm
->slot
>= n
);
1197 btrfs_set_node_key(eb
, &tm
->key
, tm
->slot
);
1198 btrfs_set_node_blockptr(eb
, tm
->slot
, tm
->blockptr
);
1199 btrfs_set_node_ptr_generation(eb
, tm
->slot
,
1202 case MOD_LOG_KEY_ADD
:
1203 /* if a move operation is needed it's in the log */
1206 case MOD_LOG_MOVE_KEYS
:
1207 o_dst
= btrfs_node_key_ptr_offset(tm
->slot
);
1208 o_src
= btrfs_node_key_ptr_offset(tm
->move
.dst_slot
);
1209 memmove_extent_buffer(eb
, o_dst
, o_src
,
1210 tm
->move
.nr_items
* p_size
);
1212 case MOD_LOG_ROOT_REPLACE
:
1214 * this operation is special. for roots, this must be
1215 * handled explicitly before rewinding.
1216 * for non-roots, this operation may exist if the node
1217 * was a root: root A -> child B; then A gets empty and
1218 * B is promoted to the new root. in the mod log, we'll
1219 * have a root-replace operation for B, a tree block
1220 * that is no root. we simply ignore that operation.
1224 next
= rb_next(&tm
->node
);
1227 tm
= container_of(next
, struct tree_mod_elem
, node
);
1228 if (tm
->index
!= first_tm
->index
)
1231 tree_mod_log_read_unlock(fs_info
);
1232 btrfs_set_header_nritems(eb
, n
);
1236 * Called with eb read locked. If the buffer cannot be rewinded, the same buffer
1237 * is returned. If rewind operations happen, a fresh buffer is returned. The
1238 * returned buffer is always read-locked. If the returned buffer is not the
1239 * input buffer, the lock on the input buffer is released and the input buffer
1240 * is freed (its refcount is decremented).
1242 static struct extent_buffer
*
1243 tree_mod_log_rewind(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
,
1246 struct extent_buffer
*eb_rewin
;
1247 struct tree_mod_elem
*tm
;
1252 if (btrfs_header_level(eb
) == 0)
1255 tm
= tree_mod_log_search(fs_info
, eb
->start
, time_seq
);
1259 if (tm
->op
== MOD_LOG_KEY_REMOVE_WHILE_FREEING
) {
1260 BUG_ON(tm
->slot
!= 0);
1261 eb_rewin
= alloc_dummy_extent_buffer(eb
->start
,
1262 fs_info
->tree_root
->nodesize
);
1264 btrfs_set_header_bytenr(eb_rewin
, eb
->start
);
1265 btrfs_set_header_backref_rev(eb_rewin
,
1266 btrfs_header_backref_rev(eb
));
1267 btrfs_set_header_owner(eb_rewin
, btrfs_header_owner(eb
));
1268 btrfs_set_header_level(eb_rewin
, btrfs_header_level(eb
));
1270 eb_rewin
= btrfs_clone_extent_buffer(eb
);
1274 btrfs_tree_read_unlock(eb
);
1275 free_extent_buffer(eb
);
1277 extent_buffer_get(eb_rewin
);
1278 btrfs_tree_read_lock(eb_rewin
);
1279 __tree_mod_log_rewind(fs_info
, eb_rewin
, time_seq
, tm
);
1280 WARN_ON(btrfs_header_nritems(eb_rewin
) >
1281 BTRFS_NODEPTRS_PER_BLOCK(fs_info
->tree_root
));
1287 * get_old_root() rewinds the state of @root's root node to the given @time_seq
1288 * value. If there are no changes, the current root->root_node is returned. If
1289 * anything changed in between, there's a fresh buffer allocated on which the
1290 * rewind operations are done. In any case, the returned buffer is read locked.
1291 * Returns NULL on error (with no locks held).
1293 static inline struct extent_buffer
*
1294 get_old_root(struct btrfs_root
*root
, u64 time_seq
)
1296 struct tree_mod_elem
*tm
;
1297 struct extent_buffer
*eb
= NULL
;
1298 struct extent_buffer
*eb_root
;
1299 struct extent_buffer
*old
;
1300 struct tree_mod_root
*old_root
= NULL
;
1301 u64 old_generation
= 0;
1305 eb_root
= btrfs_read_lock_root_node(root
);
1306 tm
= __tree_mod_log_oldest_root(root
->fs_info
, eb_root
, time_seq
);
1310 if (tm
->op
== MOD_LOG_ROOT_REPLACE
) {
1311 old_root
= &tm
->old_root
;
1312 old_generation
= tm
->generation
;
1313 logical
= old_root
->logical
;
1315 logical
= eb_root
->start
;
1318 tm
= tree_mod_log_search(root
->fs_info
, logical
, time_seq
);
1319 if (old_root
&& tm
&& tm
->op
!= MOD_LOG_KEY_REMOVE_WHILE_FREEING
) {
1320 btrfs_tree_read_unlock(eb_root
);
1321 free_extent_buffer(eb_root
);
1322 blocksize
= btrfs_level_size(root
, old_root
->level
);
1323 old
= read_tree_block(root
, logical
, blocksize
, 0);
1324 if (!old
|| !extent_buffer_uptodate(old
)) {
1325 free_extent_buffer(old
);
1326 pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
1330 eb
= btrfs_clone_extent_buffer(old
);
1331 free_extent_buffer(old
);
1333 } else if (old_root
) {
1334 btrfs_tree_read_unlock(eb_root
);
1335 free_extent_buffer(eb_root
);
1336 eb
= alloc_dummy_extent_buffer(logical
, root
->nodesize
);
1338 eb
= btrfs_clone_extent_buffer(eb_root
);
1339 btrfs_tree_read_unlock(eb_root
);
1340 free_extent_buffer(eb_root
);
1345 extent_buffer_get(eb
);
1346 btrfs_tree_read_lock(eb
);
1348 btrfs_set_header_bytenr(eb
, eb
->start
);
1349 btrfs_set_header_backref_rev(eb
, BTRFS_MIXED_BACKREF_REV
);
1350 btrfs_set_header_owner(eb
, btrfs_header_owner(eb_root
));
1351 btrfs_set_header_level(eb
, old_root
->level
);
1352 btrfs_set_header_generation(eb
, old_generation
);
1355 __tree_mod_log_rewind(root
->fs_info
, eb
, time_seq
, tm
);
1357 WARN_ON(btrfs_header_level(eb
) != 0);
1358 WARN_ON(btrfs_header_nritems(eb
) > BTRFS_NODEPTRS_PER_BLOCK(root
));
1363 int btrfs_old_root_level(struct btrfs_root
*root
, u64 time_seq
)
1365 struct tree_mod_elem
*tm
;
1367 struct extent_buffer
*eb_root
= btrfs_root_node(root
);
1369 tm
= __tree_mod_log_oldest_root(root
->fs_info
, eb_root
, time_seq
);
1370 if (tm
&& tm
->op
== MOD_LOG_ROOT_REPLACE
) {
1371 level
= tm
->old_root
.level
;
1373 level
= btrfs_header_level(eb_root
);
1375 free_extent_buffer(eb_root
);
1380 static inline int should_cow_block(struct btrfs_trans_handle
*trans
,
1381 struct btrfs_root
*root
,
1382 struct extent_buffer
*buf
)
1384 /* ensure we can see the force_cow */
1388 * We do not need to cow a block if
1389 * 1) this block is not created or changed in this transaction;
1390 * 2) this block does not belong to TREE_RELOC tree;
1391 * 3) the root is not forced COW.
1393 * What is forced COW:
1394 * when we create snapshot during commiting the transaction,
1395 * after we've finished coping src root, we must COW the shared
1396 * block to ensure the metadata consistency.
1398 if (btrfs_header_generation(buf
) == trans
->transid
&&
1399 !btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_WRITTEN
) &&
1400 !(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
&&
1401 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)) &&
1408 * cows a single block, see __btrfs_cow_block for the real work.
1409 * This version of it has extra checks so that a block isn't cow'd more than
1410 * once per transaction, as long as it hasn't been written yet
1412 noinline
int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
1413 struct btrfs_root
*root
, struct extent_buffer
*buf
,
1414 struct extent_buffer
*parent
, int parent_slot
,
1415 struct extent_buffer
**cow_ret
)
1420 if (trans
->transaction
!= root
->fs_info
->running_transaction
)
1421 WARN(1, KERN_CRIT
"trans %llu running %llu\n",
1422 (unsigned long long)trans
->transid
,
1423 (unsigned long long)
1424 root
->fs_info
->running_transaction
->transid
);
1426 if (trans
->transid
!= root
->fs_info
->generation
)
1427 WARN(1, KERN_CRIT
"trans %llu running %llu\n",
1428 (unsigned long long)trans
->transid
,
1429 (unsigned long long)root
->fs_info
->generation
);
1431 if (!should_cow_block(trans
, root
, buf
)) {
1436 search_start
= buf
->start
& ~((u64
)(1024 * 1024 * 1024) - 1);
1439 btrfs_set_lock_blocking(parent
);
1440 btrfs_set_lock_blocking(buf
);
1442 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
1443 parent_slot
, cow_ret
, search_start
, 0);
1445 trace_btrfs_cow_block(root
, buf
, *cow_ret
);
1451 * helper function for defrag to decide if two blocks pointed to by a
1452 * node are actually close by
1454 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
1456 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
1458 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
1464 * compare two keys in a memcmp fashion
1466 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
1468 struct btrfs_key k1
;
1470 btrfs_disk_key_to_cpu(&k1
, disk
);
1472 return btrfs_comp_cpu_keys(&k1
, k2
);
1476 * same as comp_keys only with two btrfs_key's
1478 int btrfs_comp_cpu_keys(struct btrfs_key
*k1
, struct btrfs_key
*k2
)
1480 if (k1
->objectid
> k2
->objectid
)
1482 if (k1
->objectid
< k2
->objectid
)
1484 if (k1
->type
> k2
->type
)
1486 if (k1
->type
< k2
->type
)
1488 if (k1
->offset
> k2
->offset
)
1490 if (k1
->offset
< k2
->offset
)
1496 * this is used by the defrag code to go through all the
1497 * leaves pointed to by a node and reallocate them so that
1498 * disk order is close to key order
1500 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
1501 struct btrfs_root
*root
, struct extent_buffer
*parent
,
1502 int start_slot
, u64
*last_ret
,
1503 struct btrfs_key
*progress
)
1505 struct extent_buffer
*cur
;
1508 u64 search_start
= *last_ret
;
1518 int progress_passed
= 0;
1519 struct btrfs_disk_key disk_key
;
1521 parent_level
= btrfs_header_level(parent
);
1523 WARN_ON(trans
->transaction
!= root
->fs_info
->running_transaction
);
1524 WARN_ON(trans
->transid
!= root
->fs_info
->generation
);
1526 parent_nritems
= btrfs_header_nritems(parent
);
1527 blocksize
= btrfs_level_size(root
, parent_level
- 1);
1528 end_slot
= parent_nritems
;
1530 if (parent_nritems
== 1)
1533 btrfs_set_lock_blocking(parent
);
1535 for (i
= start_slot
; i
< end_slot
; i
++) {
1538 btrfs_node_key(parent
, &disk_key
, i
);
1539 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
1542 progress_passed
= 1;
1543 blocknr
= btrfs_node_blockptr(parent
, i
);
1544 gen
= btrfs_node_ptr_generation(parent
, i
);
1545 if (last_block
== 0)
1546 last_block
= blocknr
;
1549 other
= btrfs_node_blockptr(parent
, i
- 1);
1550 close
= close_blocks(blocknr
, other
, blocksize
);
1552 if (!close
&& i
< end_slot
- 2) {
1553 other
= btrfs_node_blockptr(parent
, i
+ 1);
1554 close
= close_blocks(blocknr
, other
, blocksize
);
1557 last_block
= blocknr
;
1561 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
1563 uptodate
= btrfs_buffer_uptodate(cur
, gen
, 0);
1566 if (!cur
|| !uptodate
) {
1568 cur
= read_tree_block(root
, blocknr
,
1570 if (!cur
|| !extent_buffer_uptodate(cur
)) {
1571 free_extent_buffer(cur
);
1574 } else if (!uptodate
) {
1575 err
= btrfs_read_buffer(cur
, gen
);
1577 free_extent_buffer(cur
);
1582 if (search_start
== 0)
1583 search_start
= last_block
;
1585 btrfs_tree_lock(cur
);
1586 btrfs_set_lock_blocking(cur
);
1587 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
1590 (end_slot
- i
) * blocksize
));
1592 btrfs_tree_unlock(cur
);
1593 free_extent_buffer(cur
);
1596 search_start
= cur
->start
;
1597 last_block
= cur
->start
;
1598 *last_ret
= search_start
;
1599 btrfs_tree_unlock(cur
);
1600 free_extent_buffer(cur
);
1606 * The leaf data grows from end-to-front in the node.
1607 * this returns the address of the start of the last item,
1608 * which is the stop of the leaf data stack
1610 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
1611 struct extent_buffer
*leaf
)
1613 u32 nr
= btrfs_header_nritems(leaf
);
1615 return BTRFS_LEAF_DATA_SIZE(root
);
1616 return btrfs_item_offset_nr(leaf
, nr
- 1);
1621 * search for key in the extent_buffer. The items start at offset p,
1622 * and they are item_size apart. There are 'max' items in p.
1624 * the slot in the array is returned via slot, and it points to
1625 * the place where you would insert key if it is not found in
1628 * slot may point to max if the key is bigger than all of the keys
1630 static noinline
int generic_bin_search(struct extent_buffer
*eb
,
1632 int item_size
, struct btrfs_key
*key
,
1639 struct btrfs_disk_key
*tmp
= NULL
;
1640 struct btrfs_disk_key unaligned
;
1641 unsigned long offset
;
1643 unsigned long map_start
= 0;
1644 unsigned long map_len
= 0;
1647 while (low
< high
) {
1648 mid
= (low
+ high
) / 2;
1649 offset
= p
+ mid
* item_size
;
1651 if (!kaddr
|| offset
< map_start
||
1652 (offset
+ sizeof(struct btrfs_disk_key
)) >
1653 map_start
+ map_len
) {
1655 err
= map_private_extent_buffer(eb
, offset
,
1656 sizeof(struct btrfs_disk_key
),
1657 &kaddr
, &map_start
, &map_len
);
1660 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
1663 read_extent_buffer(eb
, &unaligned
,
1664 offset
, sizeof(unaligned
));
1669 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
1672 ret
= comp_keys(tmp
, key
);
1688 * simple bin_search frontend that does the right thing for
1691 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
1692 int level
, int *slot
)
1695 return generic_bin_search(eb
,
1696 offsetof(struct btrfs_leaf
, items
),
1697 sizeof(struct btrfs_item
),
1698 key
, btrfs_header_nritems(eb
),
1701 return generic_bin_search(eb
,
1702 offsetof(struct btrfs_node
, ptrs
),
1703 sizeof(struct btrfs_key_ptr
),
1704 key
, btrfs_header_nritems(eb
),
1708 int btrfs_bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
1709 int level
, int *slot
)
1711 return bin_search(eb
, key
, level
, slot
);
1714 static void root_add_used(struct btrfs_root
*root
, u32 size
)
1716 spin_lock(&root
->accounting_lock
);
1717 btrfs_set_root_used(&root
->root_item
,
1718 btrfs_root_used(&root
->root_item
) + size
);
1719 spin_unlock(&root
->accounting_lock
);
1722 static void root_sub_used(struct btrfs_root
*root
, u32 size
)
1724 spin_lock(&root
->accounting_lock
);
1725 btrfs_set_root_used(&root
->root_item
,
1726 btrfs_root_used(&root
->root_item
) - size
);
1727 spin_unlock(&root
->accounting_lock
);
1730 /* given a node and slot number, this reads the blocks it points to. The
1731 * extent buffer is returned with a reference taken (but unlocked).
1732 * NULL is returned on error.
1734 static noinline
struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
1735 struct extent_buffer
*parent
, int slot
)
1737 int level
= btrfs_header_level(parent
);
1738 struct extent_buffer
*eb
;
1742 if (slot
>= btrfs_header_nritems(parent
))
1747 eb
= read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
1748 btrfs_level_size(root
, level
- 1),
1749 btrfs_node_ptr_generation(parent
, slot
));
1750 if (eb
&& !extent_buffer_uptodate(eb
)) {
1751 free_extent_buffer(eb
);
1759 * node level balancing, used to make sure nodes are in proper order for
1760 * item deletion. We balance from the top down, so we have to make sure
1761 * that a deletion won't leave an node completely empty later on.
1763 static noinline
int balance_level(struct btrfs_trans_handle
*trans
,
1764 struct btrfs_root
*root
,
1765 struct btrfs_path
*path
, int level
)
1767 struct extent_buffer
*right
= NULL
;
1768 struct extent_buffer
*mid
;
1769 struct extent_buffer
*left
= NULL
;
1770 struct extent_buffer
*parent
= NULL
;
1774 int orig_slot
= path
->slots
[level
];
1780 mid
= path
->nodes
[level
];
1782 WARN_ON(path
->locks
[level
] != BTRFS_WRITE_LOCK
&&
1783 path
->locks
[level
] != BTRFS_WRITE_LOCK_BLOCKING
);
1784 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1786 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
1788 if (level
< BTRFS_MAX_LEVEL
- 1) {
1789 parent
= path
->nodes
[level
+ 1];
1790 pslot
= path
->slots
[level
+ 1];
1794 * deal with the case where there is only one pointer in the root
1795 * by promoting the node below to a root
1798 struct extent_buffer
*child
;
1800 if (btrfs_header_nritems(mid
) != 1)
1803 /* promote the child to a root */
1804 child
= read_node_slot(root
, mid
, 0);
1807 btrfs_std_error(root
->fs_info
, ret
);
1811 btrfs_tree_lock(child
);
1812 btrfs_set_lock_blocking(child
);
1813 ret
= btrfs_cow_block(trans
, root
, child
, mid
, 0, &child
);
1815 btrfs_tree_unlock(child
);
1816 free_extent_buffer(child
);
1820 tree_mod_log_set_root_pointer(root
, child
, 1);
1821 rcu_assign_pointer(root
->node
, child
);
1823 add_root_to_dirty_list(root
);
1824 btrfs_tree_unlock(child
);
1826 path
->locks
[level
] = 0;
1827 path
->nodes
[level
] = NULL
;
1828 clean_tree_block(trans
, root
, mid
);
1829 btrfs_tree_unlock(mid
);
1830 /* once for the path */
1831 free_extent_buffer(mid
);
1833 root_sub_used(root
, mid
->len
);
1834 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
1835 /* once for the root ptr */
1836 free_extent_buffer_stale(mid
);
1839 if (btrfs_header_nritems(mid
) >
1840 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
1843 left
= read_node_slot(root
, parent
, pslot
- 1);
1845 btrfs_tree_lock(left
);
1846 btrfs_set_lock_blocking(left
);
1847 wret
= btrfs_cow_block(trans
, root
, left
,
1848 parent
, pslot
- 1, &left
);
1854 right
= read_node_slot(root
, parent
, pslot
+ 1);
1856 btrfs_tree_lock(right
);
1857 btrfs_set_lock_blocking(right
);
1858 wret
= btrfs_cow_block(trans
, root
, right
,
1859 parent
, pslot
+ 1, &right
);
1866 /* first, try to make some room in the middle buffer */
1868 orig_slot
+= btrfs_header_nritems(left
);
1869 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1875 * then try to empty the right most buffer into the middle
1878 wret
= push_node_left(trans
, root
, mid
, right
, 1);
1879 if (wret
< 0 && wret
!= -ENOSPC
)
1881 if (btrfs_header_nritems(right
) == 0) {
1882 clean_tree_block(trans
, root
, right
);
1883 btrfs_tree_unlock(right
);
1884 del_ptr(root
, path
, level
+ 1, pslot
+ 1);
1885 root_sub_used(root
, right
->len
);
1886 btrfs_free_tree_block(trans
, root
, right
, 0, 1);
1887 free_extent_buffer_stale(right
);
1890 struct btrfs_disk_key right_key
;
1891 btrfs_node_key(right
, &right_key
, 0);
1892 tree_mod_log_set_node_key(root
->fs_info
, parent
,
1894 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
1895 btrfs_mark_buffer_dirty(parent
);
1898 if (btrfs_header_nritems(mid
) == 1) {
1900 * we're not allowed to leave a node with one item in the
1901 * tree during a delete. A deletion from lower in the tree
1902 * could try to delete the only pointer in this node.
1903 * So, pull some keys from the left.
1904 * There has to be a left pointer at this point because
1905 * otherwise we would have pulled some pointers from the
1910 btrfs_std_error(root
->fs_info
, ret
);
1913 wret
= balance_node_right(trans
, root
, mid
, left
);
1919 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1925 if (btrfs_header_nritems(mid
) == 0) {
1926 clean_tree_block(trans
, root
, mid
);
1927 btrfs_tree_unlock(mid
);
1928 del_ptr(root
, path
, level
+ 1, pslot
);
1929 root_sub_used(root
, mid
->len
);
1930 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
1931 free_extent_buffer_stale(mid
);
1934 /* update the parent key to reflect our changes */
1935 struct btrfs_disk_key mid_key
;
1936 btrfs_node_key(mid
, &mid_key
, 0);
1937 tree_mod_log_set_node_key(root
->fs_info
, parent
,
1939 btrfs_set_node_key(parent
, &mid_key
, pslot
);
1940 btrfs_mark_buffer_dirty(parent
);
1943 /* update the path */
1945 if (btrfs_header_nritems(left
) > orig_slot
) {
1946 extent_buffer_get(left
);
1947 /* left was locked after cow */
1948 path
->nodes
[level
] = left
;
1949 path
->slots
[level
+ 1] -= 1;
1950 path
->slots
[level
] = orig_slot
;
1952 btrfs_tree_unlock(mid
);
1953 free_extent_buffer(mid
);
1956 orig_slot
-= btrfs_header_nritems(left
);
1957 path
->slots
[level
] = orig_slot
;
1960 /* double check we haven't messed things up */
1962 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
1966 btrfs_tree_unlock(right
);
1967 free_extent_buffer(right
);
1970 if (path
->nodes
[level
] != left
)
1971 btrfs_tree_unlock(left
);
1972 free_extent_buffer(left
);
1977 /* Node balancing for insertion. Here we only split or push nodes around
1978 * when they are completely full. This is also done top down, so we
1979 * have to be pessimistic.
1981 static noinline
int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
1982 struct btrfs_root
*root
,
1983 struct btrfs_path
*path
, int level
)
1985 struct extent_buffer
*right
= NULL
;
1986 struct extent_buffer
*mid
;
1987 struct extent_buffer
*left
= NULL
;
1988 struct extent_buffer
*parent
= NULL
;
1992 int orig_slot
= path
->slots
[level
];
1997 mid
= path
->nodes
[level
];
1998 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
2000 if (level
< BTRFS_MAX_LEVEL
- 1) {
2001 parent
= path
->nodes
[level
+ 1];
2002 pslot
= path
->slots
[level
+ 1];
2008 left
= read_node_slot(root
, parent
, pslot
- 1);
2010 /* first, try to make some room in the middle buffer */
2014 btrfs_tree_lock(left
);
2015 btrfs_set_lock_blocking(left
);
2017 left_nr
= btrfs_header_nritems(left
);
2018 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
2021 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
2026 wret
= push_node_left(trans
, root
,
2033 struct btrfs_disk_key disk_key
;
2034 orig_slot
+= left_nr
;
2035 btrfs_node_key(mid
, &disk_key
, 0);
2036 tree_mod_log_set_node_key(root
->fs_info
, parent
,
2038 btrfs_set_node_key(parent
, &disk_key
, pslot
);
2039 btrfs_mark_buffer_dirty(parent
);
2040 if (btrfs_header_nritems(left
) > orig_slot
) {
2041 path
->nodes
[level
] = left
;
2042 path
->slots
[level
+ 1] -= 1;
2043 path
->slots
[level
] = orig_slot
;
2044 btrfs_tree_unlock(mid
);
2045 free_extent_buffer(mid
);
2048 btrfs_header_nritems(left
);
2049 path
->slots
[level
] = orig_slot
;
2050 btrfs_tree_unlock(left
);
2051 free_extent_buffer(left
);
2055 btrfs_tree_unlock(left
);
2056 free_extent_buffer(left
);
2058 right
= read_node_slot(root
, parent
, pslot
+ 1);
2061 * then try to empty the right most buffer into the middle
2066 btrfs_tree_lock(right
);
2067 btrfs_set_lock_blocking(right
);
2069 right_nr
= btrfs_header_nritems(right
);
2070 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
2073 ret
= btrfs_cow_block(trans
, root
, right
,
2079 wret
= balance_node_right(trans
, root
,
2086 struct btrfs_disk_key disk_key
;
2088 btrfs_node_key(right
, &disk_key
, 0);
2089 tree_mod_log_set_node_key(root
->fs_info
, parent
,
2091 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
2092 btrfs_mark_buffer_dirty(parent
);
2094 if (btrfs_header_nritems(mid
) <= orig_slot
) {
2095 path
->nodes
[level
] = right
;
2096 path
->slots
[level
+ 1] += 1;
2097 path
->slots
[level
] = orig_slot
-
2098 btrfs_header_nritems(mid
);
2099 btrfs_tree_unlock(mid
);
2100 free_extent_buffer(mid
);
2102 btrfs_tree_unlock(right
);
2103 free_extent_buffer(right
);
2107 btrfs_tree_unlock(right
);
2108 free_extent_buffer(right
);
2114 * readahead one full node of leaves, finding things that are close
2115 * to the block in 'slot', and triggering ra on them.
2117 static void reada_for_search(struct btrfs_root
*root
,
2118 struct btrfs_path
*path
,
2119 int level
, int slot
, u64 objectid
)
2121 struct extent_buffer
*node
;
2122 struct btrfs_disk_key disk_key
;
2128 int direction
= path
->reada
;
2129 struct extent_buffer
*eb
;
2137 if (!path
->nodes
[level
])
2140 node
= path
->nodes
[level
];
2142 search
= btrfs_node_blockptr(node
, slot
);
2143 blocksize
= btrfs_level_size(root
, level
- 1);
2144 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
2146 free_extent_buffer(eb
);
2152 nritems
= btrfs_header_nritems(node
);
2156 if (direction
< 0) {
2160 } else if (direction
> 0) {
2165 if (path
->reada
< 0 && objectid
) {
2166 btrfs_node_key(node
, &disk_key
, nr
);
2167 if (btrfs_disk_key_objectid(&disk_key
) != objectid
)
2170 search
= btrfs_node_blockptr(node
, nr
);
2171 if ((search
<= target
&& target
- search
<= 65536) ||
2172 (search
> target
&& search
- target
<= 65536)) {
2173 gen
= btrfs_node_ptr_generation(node
, nr
);
2174 readahead_tree_block(root
, search
, blocksize
, gen
);
2178 if ((nread
> 65536 || nscan
> 32))
2183 static noinline
void reada_for_balance(struct btrfs_root
*root
,
2184 struct btrfs_path
*path
, int level
)
2188 struct extent_buffer
*parent
;
2189 struct extent_buffer
*eb
;
2195 parent
= path
->nodes
[level
+ 1];
2199 nritems
= btrfs_header_nritems(parent
);
2200 slot
= path
->slots
[level
+ 1];
2201 blocksize
= btrfs_level_size(root
, level
);
2204 block1
= btrfs_node_blockptr(parent
, slot
- 1);
2205 gen
= btrfs_node_ptr_generation(parent
, slot
- 1);
2206 eb
= btrfs_find_tree_block(root
, block1
, blocksize
);
2208 * if we get -eagain from btrfs_buffer_uptodate, we
2209 * don't want to return eagain here. That will loop
2212 if (eb
&& btrfs_buffer_uptodate(eb
, gen
, 1) != 0)
2214 free_extent_buffer(eb
);
2216 if (slot
+ 1 < nritems
) {
2217 block2
= btrfs_node_blockptr(parent
, slot
+ 1);
2218 gen
= btrfs_node_ptr_generation(parent
, slot
+ 1);
2219 eb
= btrfs_find_tree_block(root
, block2
, blocksize
);
2220 if (eb
&& btrfs_buffer_uptodate(eb
, gen
, 1) != 0)
2222 free_extent_buffer(eb
);
2226 readahead_tree_block(root
, block1
, blocksize
, 0);
2228 readahead_tree_block(root
, block2
, blocksize
, 0);
2233 * when we walk down the tree, it is usually safe to unlock the higher layers
2234 * in the tree. The exceptions are when our path goes through slot 0, because
2235 * operations on the tree might require changing key pointers higher up in the
2238 * callers might also have set path->keep_locks, which tells this code to keep
2239 * the lock if the path points to the last slot in the block. This is part of
2240 * walking through the tree, and selecting the next slot in the higher block.
2242 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
2243 * if lowest_unlock is 1, level 0 won't be unlocked
2245 static noinline
void unlock_up(struct btrfs_path
*path
, int level
,
2246 int lowest_unlock
, int min_write_lock_level
,
2247 int *write_lock_level
)
2250 int skip_level
= level
;
2252 struct extent_buffer
*t
;
2254 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2255 if (!path
->nodes
[i
])
2257 if (!path
->locks
[i
])
2259 if (!no_skips
&& path
->slots
[i
] == 0) {
2263 if (!no_skips
&& path
->keep_locks
) {
2266 nritems
= btrfs_header_nritems(t
);
2267 if (nritems
< 1 || path
->slots
[i
] >= nritems
- 1) {
2272 if (skip_level
< i
&& i
>= lowest_unlock
)
2276 if (i
>= lowest_unlock
&& i
> skip_level
&& path
->locks
[i
]) {
2277 btrfs_tree_unlock_rw(t
, path
->locks
[i
]);
2279 if (write_lock_level
&&
2280 i
> min_write_lock_level
&&
2281 i
<= *write_lock_level
) {
2282 *write_lock_level
= i
- 1;
2289 * This releases any locks held in the path starting at level and
2290 * going all the way up to the root.
2292 * btrfs_search_slot will keep the lock held on higher nodes in a few
2293 * corner cases, such as COW of the block at slot zero in the node. This
2294 * ignores those rules, and it should only be called when there are no
2295 * more updates to be done higher up in the tree.
2297 noinline
void btrfs_unlock_up_safe(struct btrfs_path
*path
, int level
)
2301 if (path
->keep_locks
)
2304 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2305 if (!path
->nodes
[i
])
2307 if (!path
->locks
[i
])
2309 btrfs_tree_unlock_rw(path
->nodes
[i
], path
->locks
[i
]);
2315 * helper function for btrfs_search_slot. The goal is to find a block
2316 * in cache without setting the path to blocking. If we find the block
2317 * we return zero and the path is unchanged.
2319 * If we can't find the block, we set the path blocking and do some
2320 * reada. -EAGAIN is returned and the search must be repeated.
2323 read_block_for_search(struct btrfs_trans_handle
*trans
,
2324 struct btrfs_root
*root
, struct btrfs_path
*p
,
2325 struct extent_buffer
**eb_ret
, int level
, int slot
,
2326 struct btrfs_key
*key
, u64 time_seq
)
2331 struct extent_buffer
*b
= *eb_ret
;
2332 struct extent_buffer
*tmp
;
2335 blocknr
= btrfs_node_blockptr(b
, slot
);
2336 gen
= btrfs_node_ptr_generation(b
, slot
);
2337 blocksize
= btrfs_level_size(root
, level
- 1);
2339 tmp
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
2341 /* first we do an atomic uptodate check */
2342 if (btrfs_buffer_uptodate(tmp
, gen
, 1) > 0) {
2347 /* the pages were up to date, but we failed
2348 * the generation number check. Do a full
2349 * read for the generation number that is correct.
2350 * We must do this without dropping locks so
2351 * we can trust our generation number
2353 btrfs_set_path_blocking(p
);
2355 /* now we're allowed to do a blocking uptodate check */
2356 ret
= btrfs_read_buffer(tmp
, gen
);
2361 free_extent_buffer(tmp
);
2362 btrfs_release_path(p
);
2367 * reduce lock contention at high levels
2368 * of the btree by dropping locks before
2369 * we read. Don't release the lock on the current
2370 * level because we need to walk this node to figure
2371 * out which blocks to read.
2373 btrfs_unlock_up_safe(p
, level
+ 1);
2374 btrfs_set_path_blocking(p
);
2376 free_extent_buffer(tmp
);
2378 reada_for_search(root
, p
, level
, slot
, key
->objectid
);
2380 btrfs_release_path(p
);
2383 tmp
= read_tree_block(root
, blocknr
, blocksize
, 0);
2386 * If the read above didn't mark this buffer up to date,
2387 * it will never end up being up to date. Set ret to EIO now
2388 * and give up so that our caller doesn't loop forever
2391 if (!btrfs_buffer_uptodate(tmp
, 0, 0))
2393 free_extent_buffer(tmp
);
2399 * helper function for btrfs_search_slot. This does all of the checks
2400 * for node-level blocks and does any balancing required based on
2403 * If no extra work was required, zero is returned. If we had to
2404 * drop the path, -EAGAIN is returned and btrfs_search_slot must
2408 setup_nodes_for_search(struct btrfs_trans_handle
*trans
,
2409 struct btrfs_root
*root
, struct btrfs_path
*p
,
2410 struct extent_buffer
*b
, int level
, int ins_len
,
2411 int *write_lock_level
)
2414 if ((p
->search_for_split
|| ins_len
> 0) && btrfs_header_nritems(b
) >=
2415 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3) {
2418 if (*write_lock_level
< level
+ 1) {
2419 *write_lock_level
= level
+ 1;
2420 btrfs_release_path(p
);
2424 btrfs_set_path_blocking(p
);
2425 reada_for_balance(root
, p
, level
);
2426 sret
= split_node(trans
, root
, p
, level
);
2427 btrfs_clear_path_blocking(p
, NULL
, 0);
2434 b
= p
->nodes
[level
];
2435 } else if (ins_len
< 0 && btrfs_header_nritems(b
) <
2436 BTRFS_NODEPTRS_PER_BLOCK(root
) / 2) {
2439 if (*write_lock_level
< level
+ 1) {
2440 *write_lock_level
= level
+ 1;
2441 btrfs_release_path(p
);
2445 btrfs_set_path_blocking(p
);
2446 reada_for_balance(root
, p
, level
);
2447 sret
= balance_level(trans
, root
, p
, level
);
2448 btrfs_clear_path_blocking(p
, NULL
, 0);
2454 b
= p
->nodes
[level
];
2456 btrfs_release_path(p
);
2459 BUG_ON(btrfs_header_nritems(b
) == 1);
2470 * look for key in the tree. path is filled in with nodes along the way
2471 * if key is found, we return zero and you can find the item in the leaf
2472 * level of the path (level 0)
2474 * If the key isn't found, the path points to the slot where it should
2475 * be inserted, and 1 is returned. If there are other errors during the
2476 * search a negative error number is returned.
2478 * if ins_len > 0, nodes and leaves will be split as we walk down the
2479 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
2482 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
2483 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
2486 struct extent_buffer
*b
;
2491 int lowest_unlock
= 1;
2493 /* everything at write_lock_level or lower must be write locked */
2494 int write_lock_level
= 0;
2495 u8 lowest_level
= 0;
2496 int min_write_lock_level
;
2498 lowest_level
= p
->lowest_level
;
2499 WARN_ON(lowest_level
&& ins_len
> 0);
2500 WARN_ON(p
->nodes
[0] != NULL
);
2505 /* when we are removing items, we might have to go up to level
2506 * two as we update tree pointers Make sure we keep write
2507 * for those levels as well
2509 write_lock_level
= 2;
2510 } else if (ins_len
> 0) {
2512 * for inserting items, make sure we have a write lock on
2513 * level 1 so we can update keys
2515 write_lock_level
= 1;
2519 write_lock_level
= -1;
2521 if (cow
&& (p
->keep_locks
|| p
->lowest_level
))
2522 write_lock_level
= BTRFS_MAX_LEVEL
;
2524 min_write_lock_level
= write_lock_level
;
2528 * we try very hard to do read locks on the root
2530 root_lock
= BTRFS_READ_LOCK
;
2532 if (p
->search_commit_root
) {
2534 * the commit roots are read only
2535 * so we always do read locks
2537 b
= root
->commit_root
;
2538 extent_buffer_get(b
);
2539 level
= btrfs_header_level(b
);
2540 if (!p
->skip_locking
)
2541 btrfs_tree_read_lock(b
);
2543 if (p
->skip_locking
) {
2544 b
= btrfs_root_node(root
);
2545 level
= btrfs_header_level(b
);
2547 /* we don't know the level of the root node
2548 * until we actually have it read locked
2550 b
= btrfs_read_lock_root_node(root
);
2551 level
= btrfs_header_level(b
);
2552 if (level
<= write_lock_level
) {
2553 /* whoops, must trade for write lock */
2554 btrfs_tree_read_unlock(b
);
2555 free_extent_buffer(b
);
2556 b
= btrfs_lock_root_node(root
);
2557 root_lock
= BTRFS_WRITE_LOCK
;
2559 /* the level might have changed, check again */
2560 level
= btrfs_header_level(b
);
2564 p
->nodes
[level
] = b
;
2565 if (!p
->skip_locking
)
2566 p
->locks
[level
] = root_lock
;
2569 level
= btrfs_header_level(b
);
2572 * setup the path here so we can release it under lock
2573 * contention with the cow code
2577 * if we don't really need to cow this block
2578 * then we don't want to set the path blocking,
2579 * so we test it here
2581 if (!should_cow_block(trans
, root
, b
))
2584 btrfs_set_path_blocking(p
);
2587 * must have write locks on this node and the
2590 if (level
> write_lock_level
||
2591 (level
+ 1 > write_lock_level
&&
2592 level
+ 1 < BTRFS_MAX_LEVEL
&&
2593 p
->nodes
[level
+ 1])) {
2594 write_lock_level
= level
+ 1;
2595 btrfs_release_path(p
);
2599 err
= btrfs_cow_block(trans
, root
, b
,
2600 p
->nodes
[level
+ 1],
2601 p
->slots
[level
+ 1], &b
);
2608 BUG_ON(!cow
&& ins_len
);
2610 p
->nodes
[level
] = b
;
2611 btrfs_clear_path_blocking(p
, NULL
, 0);
2614 * we have a lock on b and as long as we aren't changing
2615 * the tree, there is no way to for the items in b to change.
2616 * It is safe to drop the lock on our parent before we
2617 * go through the expensive btree search on b.
2619 * If cow is true, then we might be changing slot zero,
2620 * which may require changing the parent. So, we can't
2621 * drop the lock until after we know which slot we're
2625 btrfs_unlock_up_safe(p
, level
+ 1);
2627 ret
= bin_search(b
, key
, level
, &slot
);
2631 if (ret
&& slot
> 0) {
2635 p
->slots
[level
] = slot
;
2636 err
= setup_nodes_for_search(trans
, root
, p
, b
, level
,
2637 ins_len
, &write_lock_level
);
2644 b
= p
->nodes
[level
];
2645 slot
= p
->slots
[level
];
2648 * slot 0 is special, if we change the key
2649 * we have to update the parent pointer
2650 * which means we must have a write lock
2653 if (slot
== 0 && cow
&&
2654 write_lock_level
< level
+ 1) {
2655 write_lock_level
= level
+ 1;
2656 btrfs_release_path(p
);
2660 unlock_up(p
, level
, lowest_unlock
,
2661 min_write_lock_level
, &write_lock_level
);
2663 if (level
== lowest_level
) {
2669 err
= read_block_for_search(trans
, root
, p
,
2670 &b
, level
, slot
, key
, 0);
2678 if (!p
->skip_locking
) {
2679 level
= btrfs_header_level(b
);
2680 if (level
<= write_lock_level
) {
2681 err
= btrfs_try_tree_write_lock(b
);
2683 btrfs_set_path_blocking(p
);
2685 btrfs_clear_path_blocking(p
, b
,
2688 p
->locks
[level
] = BTRFS_WRITE_LOCK
;
2690 err
= btrfs_try_tree_read_lock(b
);
2692 btrfs_set_path_blocking(p
);
2693 btrfs_tree_read_lock(b
);
2694 btrfs_clear_path_blocking(p
, b
,
2697 p
->locks
[level
] = BTRFS_READ_LOCK
;
2699 p
->nodes
[level
] = b
;
2702 p
->slots
[level
] = slot
;
2704 btrfs_leaf_free_space(root
, b
) < ins_len
) {
2705 if (write_lock_level
< 1) {
2706 write_lock_level
= 1;
2707 btrfs_release_path(p
);
2711 btrfs_set_path_blocking(p
);
2712 err
= split_leaf(trans
, root
, key
,
2713 p
, ins_len
, ret
== 0);
2714 btrfs_clear_path_blocking(p
, NULL
, 0);
2722 if (!p
->search_for_split
)
2723 unlock_up(p
, level
, lowest_unlock
,
2724 min_write_lock_level
, &write_lock_level
);
2731 * we don't really know what they plan on doing with the path
2732 * from here on, so for now just mark it as blocking
2734 if (!p
->leave_spinning
)
2735 btrfs_set_path_blocking(p
);
2737 btrfs_release_path(p
);
2742 * Like btrfs_search_slot, this looks for a key in the given tree. It uses the
2743 * current state of the tree together with the operations recorded in the tree
2744 * modification log to search for the key in a previous version of this tree, as
2745 * denoted by the time_seq parameter.
2747 * Naturally, there is no support for insert, delete or cow operations.
2749 * The resulting path and return value will be set up as if we called
2750 * btrfs_search_slot at that point in time with ins_len and cow both set to 0.
2752 int btrfs_search_old_slot(struct btrfs_root
*root
, struct btrfs_key
*key
,
2753 struct btrfs_path
*p
, u64 time_seq
)
2755 struct extent_buffer
*b
;
2760 int lowest_unlock
= 1;
2761 u8 lowest_level
= 0;
2763 lowest_level
= p
->lowest_level
;
2764 WARN_ON(p
->nodes
[0] != NULL
);
2766 if (p
->search_commit_root
) {
2768 return btrfs_search_slot(NULL
, root
, key
, p
, 0, 0);
2772 b
= get_old_root(root
, time_seq
);
2773 level
= btrfs_header_level(b
);
2774 p
->locks
[level
] = BTRFS_READ_LOCK
;
2777 level
= btrfs_header_level(b
);
2778 p
->nodes
[level
] = b
;
2779 btrfs_clear_path_blocking(p
, NULL
, 0);
2782 * we have a lock on b and as long as we aren't changing
2783 * the tree, there is no way to for the items in b to change.
2784 * It is safe to drop the lock on our parent before we
2785 * go through the expensive btree search on b.
2787 btrfs_unlock_up_safe(p
, level
+ 1);
2789 ret
= bin_search(b
, key
, level
, &slot
);
2793 if (ret
&& slot
> 0) {
2797 p
->slots
[level
] = slot
;
2798 unlock_up(p
, level
, lowest_unlock
, 0, NULL
);
2800 if (level
== lowest_level
) {
2806 err
= read_block_for_search(NULL
, root
, p
, &b
, level
,
2807 slot
, key
, time_seq
);
2815 level
= btrfs_header_level(b
);
2816 err
= btrfs_try_tree_read_lock(b
);
2818 btrfs_set_path_blocking(p
);
2819 btrfs_tree_read_lock(b
);
2820 btrfs_clear_path_blocking(p
, b
,
2823 b
= tree_mod_log_rewind(root
->fs_info
, b
, time_seq
);
2824 p
->locks
[level
] = BTRFS_READ_LOCK
;
2825 p
->nodes
[level
] = b
;
2827 p
->slots
[level
] = slot
;
2828 unlock_up(p
, level
, lowest_unlock
, 0, NULL
);
2834 if (!p
->leave_spinning
)
2835 btrfs_set_path_blocking(p
);
2837 btrfs_release_path(p
);
2843 * helper to use instead of search slot if no exact match is needed but
2844 * instead the next or previous item should be returned.
2845 * When find_higher is true, the next higher item is returned, the next lower
2847 * When return_any and find_higher are both true, and no higher item is found,
2848 * return the next lower instead.
2849 * When return_any is true and find_higher is false, and no lower item is found,
2850 * return the next higher instead.
2851 * It returns 0 if any item is found, 1 if none is found (tree empty), and
2854 int btrfs_search_slot_for_read(struct btrfs_root
*root
,
2855 struct btrfs_key
*key
, struct btrfs_path
*p
,
2856 int find_higher
, int return_any
)
2859 struct extent_buffer
*leaf
;
2862 ret
= btrfs_search_slot(NULL
, root
, key
, p
, 0, 0);
2866 * a return value of 1 means the path is at the position where the
2867 * item should be inserted. Normally this is the next bigger item,
2868 * but in case the previous item is the last in a leaf, path points
2869 * to the first free slot in the previous leaf, i.e. at an invalid
2875 if (p
->slots
[0] >= btrfs_header_nritems(leaf
)) {
2876 ret
= btrfs_next_leaf(root
, p
);
2882 * no higher item found, return the next
2887 btrfs_release_path(p
);
2891 if (p
->slots
[0] == 0) {
2892 ret
= btrfs_prev_leaf(root
, p
);
2896 p
->slots
[0] = btrfs_header_nritems(leaf
) - 1;
2902 * no lower item found, return the next
2907 btrfs_release_path(p
);
2917 * adjust the pointers going up the tree, starting at level
2918 * making sure the right key of each node is points to 'key'.
2919 * This is used after shifting pointers to the left, so it stops
2920 * fixing up pointers when a given leaf/node is not in slot 0 of the
2924 static void fixup_low_keys(struct btrfs_root
*root
, struct btrfs_path
*path
,
2925 struct btrfs_disk_key
*key
, int level
)
2928 struct extent_buffer
*t
;
2930 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2931 int tslot
= path
->slots
[i
];
2932 if (!path
->nodes
[i
])
2935 tree_mod_log_set_node_key(root
->fs_info
, t
, tslot
, 1);
2936 btrfs_set_node_key(t
, key
, tslot
);
2937 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
2946 * This function isn't completely safe. It's the caller's responsibility
2947 * that the new key won't break the order
2949 void btrfs_set_item_key_safe(struct btrfs_root
*root
, struct btrfs_path
*path
,
2950 struct btrfs_key
*new_key
)
2952 struct btrfs_disk_key disk_key
;
2953 struct extent_buffer
*eb
;
2956 eb
= path
->nodes
[0];
2957 slot
= path
->slots
[0];
2959 btrfs_item_key(eb
, &disk_key
, slot
- 1);
2960 BUG_ON(comp_keys(&disk_key
, new_key
) >= 0);
2962 if (slot
< btrfs_header_nritems(eb
) - 1) {
2963 btrfs_item_key(eb
, &disk_key
, slot
+ 1);
2964 BUG_ON(comp_keys(&disk_key
, new_key
) <= 0);
2967 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
2968 btrfs_set_item_key(eb
, &disk_key
, slot
);
2969 btrfs_mark_buffer_dirty(eb
);
2971 fixup_low_keys(root
, path
, &disk_key
, 1);
2975 * try to push data from one node into the next node left in the
2978 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
2979 * error, and > 0 if there was no room in the left hand block.
2981 static int push_node_left(struct btrfs_trans_handle
*trans
,
2982 struct btrfs_root
*root
, struct extent_buffer
*dst
,
2983 struct extent_buffer
*src
, int empty
)
2990 src_nritems
= btrfs_header_nritems(src
);
2991 dst_nritems
= btrfs_header_nritems(dst
);
2992 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
2993 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
2994 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
2996 if (!empty
&& src_nritems
<= 8)
2999 if (push_items
<= 0)
3003 push_items
= min(src_nritems
, push_items
);
3004 if (push_items
< src_nritems
) {
3005 /* leave at least 8 pointers in the node if
3006 * we aren't going to empty it
3008 if (src_nritems
- push_items
< 8) {
3009 if (push_items
<= 8)
3015 push_items
= min(src_nritems
- 8, push_items
);
3017 tree_mod_log_eb_copy(root
->fs_info
, dst
, src
, dst_nritems
, 0,
3019 copy_extent_buffer(dst
, src
,
3020 btrfs_node_key_ptr_offset(dst_nritems
),
3021 btrfs_node_key_ptr_offset(0),
3022 push_items
* sizeof(struct btrfs_key_ptr
));
3024 if (push_items
< src_nritems
) {
3026 * don't call tree_mod_log_eb_move here, key removal was already
3027 * fully logged by tree_mod_log_eb_copy above.
3029 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
3030 btrfs_node_key_ptr_offset(push_items
),
3031 (src_nritems
- push_items
) *
3032 sizeof(struct btrfs_key_ptr
));
3034 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
3035 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
3036 btrfs_mark_buffer_dirty(src
);
3037 btrfs_mark_buffer_dirty(dst
);
3043 * try to push data from one node into the next node right in the
3046 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
3047 * error, and > 0 if there was no room in the right hand block.
3049 * this will only push up to 1/2 the contents of the left node over
3051 static int balance_node_right(struct btrfs_trans_handle
*trans
,
3052 struct btrfs_root
*root
,
3053 struct extent_buffer
*dst
,
3054 struct extent_buffer
*src
)
3062 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
3063 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
3065 src_nritems
= btrfs_header_nritems(src
);
3066 dst_nritems
= btrfs_header_nritems(dst
);
3067 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
3068 if (push_items
<= 0)
3071 if (src_nritems
< 4)
3074 max_push
= src_nritems
/ 2 + 1;
3075 /* don't try to empty the node */
3076 if (max_push
>= src_nritems
)
3079 if (max_push
< push_items
)
3080 push_items
= max_push
;
3082 tree_mod_log_eb_move(root
->fs_info
, dst
, push_items
, 0, dst_nritems
);
3083 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
3084 btrfs_node_key_ptr_offset(0),
3086 sizeof(struct btrfs_key_ptr
));
3088 tree_mod_log_eb_copy(root
->fs_info
, dst
, src
, 0,
3089 src_nritems
- push_items
, push_items
);
3090 copy_extent_buffer(dst
, src
,
3091 btrfs_node_key_ptr_offset(0),
3092 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
3093 push_items
* sizeof(struct btrfs_key_ptr
));
3095 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
3096 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
3098 btrfs_mark_buffer_dirty(src
);
3099 btrfs_mark_buffer_dirty(dst
);
3105 * helper function to insert a new root level in the tree.
3106 * A new node is allocated, and a single item is inserted to
3107 * point to the existing root
3109 * returns zero on success or < 0 on failure.
3111 static noinline
int insert_new_root(struct btrfs_trans_handle
*trans
,
3112 struct btrfs_root
*root
,
3113 struct btrfs_path
*path
, int level
)
3116 struct extent_buffer
*lower
;
3117 struct extent_buffer
*c
;
3118 struct extent_buffer
*old
;
3119 struct btrfs_disk_key lower_key
;
3121 BUG_ON(path
->nodes
[level
]);
3122 BUG_ON(path
->nodes
[level
-1] != root
->node
);
3124 lower
= path
->nodes
[level
-1];
3126 btrfs_item_key(lower
, &lower_key
, 0);
3128 btrfs_node_key(lower
, &lower_key
, 0);
3130 c
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
3131 root
->root_key
.objectid
, &lower_key
,
3132 level
, root
->node
->start
, 0);
3136 root_add_used(root
, root
->nodesize
);
3138 memset_extent_buffer(c
, 0, 0, sizeof(struct btrfs_header
));
3139 btrfs_set_header_nritems(c
, 1);
3140 btrfs_set_header_level(c
, level
);
3141 btrfs_set_header_bytenr(c
, c
->start
);
3142 btrfs_set_header_generation(c
, trans
->transid
);
3143 btrfs_set_header_backref_rev(c
, BTRFS_MIXED_BACKREF_REV
);
3144 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
3146 write_extent_buffer(c
, root
->fs_info
->fsid
,
3147 (unsigned long)btrfs_header_fsid(c
),
3150 write_extent_buffer(c
, root
->fs_info
->chunk_tree_uuid
,
3151 (unsigned long)btrfs_header_chunk_tree_uuid(c
),
3154 btrfs_set_node_key(c
, &lower_key
, 0);
3155 btrfs_set_node_blockptr(c
, 0, lower
->start
);
3156 lower_gen
= btrfs_header_generation(lower
);
3157 WARN_ON(lower_gen
!= trans
->transid
);
3159 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
3161 btrfs_mark_buffer_dirty(c
);
3164 tree_mod_log_set_root_pointer(root
, c
, 0);
3165 rcu_assign_pointer(root
->node
, c
);
3167 /* the super has an extra ref to root->node */
3168 free_extent_buffer(old
);
3170 add_root_to_dirty_list(root
);
3171 extent_buffer_get(c
);
3172 path
->nodes
[level
] = c
;
3173 path
->locks
[level
] = BTRFS_WRITE_LOCK
;
3174 path
->slots
[level
] = 0;
3179 * worker function to insert a single pointer in a node.
3180 * the node should have enough room for the pointer already
3182 * slot and level indicate where you want the key to go, and
3183 * blocknr is the block the key points to.
3185 static void insert_ptr(struct btrfs_trans_handle
*trans
,
3186 struct btrfs_root
*root
, struct btrfs_path
*path
,
3187 struct btrfs_disk_key
*key
, u64 bytenr
,
3188 int slot
, int level
)
3190 struct extent_buffer
*lower
;
3194 BUG_ON(!path
->nodes
[level
]);
3195 btrfs_assert_tree_locked(path
->nodes
[level
]);
3196 lower
= path
->nodes
[level
];
3197 nritems
= btrfs_header_nritems(lower
);
3198 BUG_ON(slot
> nritems
);
3199 BUG_ON(nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
));
3200 if (slot
!= nritems
) {
3202 tree_mod_log_eb_move(root
->fs_info
, lower
, slot
+ 1,
3203 slot
, nritems
- slot
);
3204 memmove_extent_buffer(lower
,
3205 btrfs_node_key_ptr_offset(slot
+ 1),
3206 btrfs_node_key_ptr_offset(slot
),
3207 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
3210 ret
= tree_mod_log_insert_key(root
->fs_info
, lower
, slot
,
3214 btrfs_set_node_key(lower
, key
, slot
);
3215 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
3216 WARN_ON(trans
->transid
== 0);
3217 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
3218 btrfs_set_header_nritems(lower
, nritems
+ 1);
3219 btrfs_mark_buffer_dirty(lower
);
3223 * split the node at the specified level in path in two.
3224 * The path is corrected to point to the appropriate node after the split
3226 * Before splitting this tries to make some room in the node by pushing
3227 * left and right, if either one works, it returns right away.
3229 * returns 0 on success and < 0 on failure
3231 static noinline
int split_node(struct btrfs_trans_handle
*trans
,
3232 struct btrfs_root
*root
,
3233 struct btrfs_path
*path
, int level
)
3235 struct extent_buffer
*c
;
3236 struct extent_buffer
*split
;
3237 struct btrfs_disk_key disk_key
;
3242 c
= path
->nodes
[level
];
3243 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
3244 if (c
== root
->node
) {
3246 * trying to split the root, lets make a new one
3248 * tree mod log: We don't log_removal old root in
3249 * insert_new_root, because that root buffer will be kept as a
3250 * normal node. We are going to log removal of half of the
3251 * elements below with tree_mod_log_eb_copy. We're holding a
3252 * tree lock on the buffer, which is why we cannot race with
3253 * other tree_mod_log users.
3255 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
3259 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
3260 c
= path
->nodes
[level
];
3261 if (!ret
&& btrfs_header_nritems(c
) <
3262 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3)
3268 c_nritems
= btrfs_header_nritems(c
);
3269 mid
= (c_nritems
+ 1) / 2;
3270 btrfs_node_key(c
, &disk_key
, mid
);
3272 split
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
3273 root
->root_key
.objectid
,
3274 &disk_key
, level
, c
->start
, 0);
3276 return PTR_ERR(split
);
3278 root_add_used(root
, root
->nodesize
);
3280 memset_extent_buffer(split
, 0, 0, sizeof(struct btrfs_header
));
3281 btrfs_set_header_level(split
, btrfs_header_level(c
));
3282 btrfs_set_header_bytenr(split
, split
->start
);
3283 btrfs_set_header_generation(split
, trans
->transid
);
3284 btrfs_set_header_backref_rev(split
, BTRFS_MIXED_BACKREF_REV
);
3285 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
3286 write_extent_buffer(split
, root
->fs_info
->fsid
,
3287 (unsigned long)btrfs_header_fsid(split
),
3289 write_extent_buffer(split
, root
->fs_info
->chunk_tree_uuid
,
3290 (unsigned long)btrfs_header_chunk_tree_uuid(split
),
3293 tree_mod_log_eb_copy(root
->fs_info
, split
, c
, 0, mid
, c_nritems
- mid
);
3294 copy_extent_buffer(split
, c
,
3295 btrfs_node_key_ptr_offset(0),
3296 btrfs_node_key_ptr_offset(mid
),
3297 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
3298 btrfs_set_header_nritems(split
, c_nritems
- mid
);
3299 btrfs_set_header_nritems(c
, mid
);
3302 btrfs_mark_buffer_dirty(c
);
3303 btrfs_mark_buffer_dirty(split
);
3305 insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
3306 path
->slots
[level
+ 1] + 1, level
+ 1);
3308 if (path
->slots
[level
] >= mid
) {
3309 path
->slots
[level
] -= mid
;
3310 btrfs_tree_unlock(c
);
3311 free_extent_buffer(c
);
3312 path
->nodes
[level
] = split
;
3313 path
->slots
[level
+ 1] += 1;
3315 btrfs_tree_unlock(split
);
3316 free_extent_buffer(split
);
3322 * how many bytes are required to store the items in a leaf. start
3323 * and nr indicate which items in the leaf to check. This totals up the
3324 * space used both by the item structs and the item data
3326 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
3328 struct btrfs_item
*start_item
;
3329 struct btrfs_item
*end_item
;
3330 struct btrfs_map_token token
;
3332 int nritems
= btrfs_header_nritems(l
);
3333 int end
= min(nritems
, start
+ nr
) - 1;
3337 btrfs_init_map_token(&token
);
3338 start_item
= btrfs_item_nr(l
, start
);
3339 end_item
= btrfs_item_nr(l
, end
);
3340 data_len
= btrfs_token_item_offset(l
, start_item
, &token
) +
3341 btrfs_token_item_size(l
, start_item
, &token
);
3342 data_len
= data_len
- btrfs_token_item_offset(l
, end_item
, &token
);
3343 data_len
+= sizeof(struct btrfs_item
) * nr
;
3344 WARN_ON(data_len
< 0);
3349 * The space between the end of the leaf items and
3350 * the start of the leaf data. IOW, how much room
3351 * the leaf has left for both items and data
3353 noinline
int btrfs_leaf_free_space(struct btrfs_root
*root
,
3354 struct extent_buffer
*leaf
)
3356 int nritems
= btrfs_header_nritems(leaf
);
3358 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
3360 printk(KERN_CRIT
"leaf free space ret %d, leaf data size %lu, "
3361 "used %d nritems %d\n",
3362 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
3363 leaf_space_used(leaf
, 0, nritems
), nritems
);
3369 * min slot controls the lowest index we're willing to push to the
3370 * right. We'll push up to and including min_slot, but no lower
3372 static noinline
int __push_leaf_right(struct btrfs_trans_handle
*trans
,
3373 struct btrfs_root
*root
,
3374 struct btrfs_path
*path
,
3375 int data_size
, int empty
,
3376 struct extent_buffer
*right
,
3377 int free_space
, u32 left_nritems
,
3380 struct extent_buffer
*left
= path
->nodes
[0];
3381 struct extent_buffer
*upper
= path
->nodes
[1];
3382 struct btrfs_map_token token
;
3383 struct btrfs_disk_key disk_key
;
3388 struct btrfs_item
*item
;
3394 btrfs_init_map_token(&token
);
3399 nr
= max_t(u32
, 1, min_slot
);
3401 if (path
->slots
[0] >= left_nritems
)
3402 push_space
+= data_size
;
3404 slot
= path
->slots
[1];
3405 i
= left_nritems
- 1;
3407 item
= btrfs_item_nr(left
, i
);
3409 if (!empty
&& push_items
> 0) {
3410 if (path
->slots
[0] > i
)
3412 if (path
->slots
[0] == i
) {
3413 int space
= btrfs_leaf_free_space(root
, left
);
3414 if (space
+ push_space
* 2 > free_space
)
3419 if (path
->slots
[0] == i
)
3420 push_space
+= data_size
;
3422 this_item_size
= btrfs_item_size(left
, item
);
3423 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
3427 push_space
+= this_item_size
+ sizeof(*item
);
3433 if (push_items
== 0)
3436 WARN_ON(!empty
&& push_items
== left_nritems
);
3438 /* push left to right */
3439 right_nritems
= btrfs_header_nritems(right
);
3441 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
3442 push_space
-= leaf_data_end(root
, left
);
3444 /* make room in the right data area */
3445 data_end
= leaf_data_end(root
, right
);
3446 memmove_extent_buffer(right
,
3447 btrfs_leaf_data(right
) + data_end
- push_space
,
3448 btrfs_leaf_data(right
) + data_end
,
3449 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
3451 /* copy from the left data area */
3452 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
3453 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
3454 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
3457 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
3458 btrfs_item_nr_offset(0),
3459 right_nritems
* sizeof(struct btrfs_item
));
3461 /* copy the items from left to right */
3462 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
3463 btrfs_item_nr_offset(left_nritems
- push_items
),
3464 push_items
* sizeof(struct btrfs_item
));
3466 /* update the item pointers */
3467 right_nritems
+= push_items
;
3468 btrfs_set_header_nritems(right
, right_nritems
);
3469 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
3470 for (i
= 0; i
< right_nritems
; i
++) {
3471 item
= btrfs_item_nr(right
, i
);
3472 push_space
-= btrfs_token_item_size(right
, item
, &token
);
3473 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
3476 left_nritems
-= push_items
;
3477 btrfs_set_header_nritems(left
, left_nritems
);
3480 btrfs_mark_buffer_dirty(left
);
3482 clean_tree_block(trans
, root
, left
);
3484 btrfs_mark_buffer_dirty(right
);
3486 btrfs_item_key(right
, &disk_key
, 0);
3487 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
3488 btrfs_mark_buffer_dirty(upper
);
3490 /* then fixup the leaf pointer in the path */
3491 if (path
->slots
[0] >= left_nritems
) {
3492 path
->slots
[0] -= left_nritems
;
3493 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
3494 clean_tree_block(trans
, root
, path
->nodes
[0]);
3495 btrfs_tree_unlock(path
->nodes
[0]);
3496 free_extent_buffer(path
->nodes
[0]);
3497 path
->nodes
[0] = right
;
3498 path
->slots
[1] += 1;
3500 btrfs_tree_unlock(right
);
3501 free_extent_buffer(right
);
3506 btrfs_tree_unlock(right
);
3507 free_extent_buffer(right
);
3512 * push some data in the path leaf to the right, trying to free up at
3513 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3515 * returns 1 if the push failed because the other node didn't have enough
3516 * room, 0 if everything worked out and < 0 if there were major errors.
3518 * this will push starting from min_slot to the end of the leaf. It won't
3519 * push any slot lower than min_slot
3521 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
3522 *root
, struct btrfs_path
*path
,
3523 int min_data_size
, int data_size
,
3524 int empty
, u32 min_slot
)
3526 struct extent_buffer
*left
= path
->nodes
[0];
3527 struct extent_buffer
*right
;
3528 struct extent_buffer
*upper
;
3534 if (!path
->nodes
[1])
3537 slot
= path
->slots
[1];
3538 upper
= path
->nodes
[1];
3539 if (slot
>= btrfs_header_nritems(upper
) - 1)
3542 btrfs_assert_tree_locked(path
->nodes
[1]);
3544 right
= read_node_slot(root
, upper
, slot
+ 1);
3548 btrfs_tree_lock(right
);
3549 btrfs_set_lock_blocking(right
);
3551 free_space
= btrfs_leaf_free_space(root
, right
);
3552 if (free_space
< data_size
)
3555 /* cow and double check */
3556 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
3561 free_space
= btrfs_leaf_free_space(root
, right
);
3562 if (free_space
< data_size
)
3565 left_nritems
= btrfs_header_nritems(left
);
3566 if (left_nritems
== 0)
3569 return __push_leaf_right(trans
, root
, path
, min_data_size
, empty
,
3570 right
, free_space
, left_nritems
, min_slot
);
3572 btrfs_tree_unlock(right
);
3573 free_extent_buffer(right
);
3578 * push some data in the path leaf to the left, trying to free up at
3579 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3581 * max_slot can put a limit on how far into the leaf we'll push items. The
3582 * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
3585 static noinline
int __push_leaf_left(struct btrfs_trans_handle
*trans
,
3586 struct btrfs_root
*root
,
3587 struct btrfs_path
*path
, int data_size
,
3588 int empty
, struct extent_buffer
*left
,
3589 int free_space
, u32 right_nritems
,
3592 struct btrfs_disk_key disk_key
;
3593 struct extent_buffer
*right
= path
->nodes
[0];
3597 struct btrfs_item
*item
;
3598 u32 old_left_nritems
;
3602 u32 old_left_item_size
;
3603 struct btrfs_map_token token
;
3605 btrfs_init_map_token(&token
);
3608 nr
= min(right_nritems
, max_slot
);
3610 nr
= min(right_nritems
- 1, max_slot
);
3612 for (i
= 0; i
< nr
; i
++) {
3613 item
= btrfs_item_nr(right
, i
);
3615 if (!empty
&& push_items
> 0) {
3616 if (path
->slots
[0] < i
)
3618 if (path
->slots
[0] == i
) {
3619 int space
= btrfs_leaf_free_space(root
, right
);
3620 if (space
+ push_space
* 2 > free_space
)
3625 if (path
->slots
[0] == i
)
3626 push_space
+= data_size
;
3628 this_item_size
= btrfs_item_size(right
, item
);
3629 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
3633 push_space
+= this_item_size
+ sizeof(*item
);
3636 if (push_items
== 0) {
3640 if (!empty
&& push_items
== btrfs_header_nritems(right
))
3643 /* push data from right to left */
3644 copy_extent_buffer(left
, right
,
3645 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
3646 btrfs_item_nr_offset(0),
3647 push_items
* sizeof(struct btrfs_item
));
3649 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
3650 btrfs_item_offset_nr(right
, push_items
- 1);
3652 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
3653 leaf_data_end(root
, left
) - push_space
,
3654 btrfs_leaf_data(right
) +
3655 btrfs_item_offset_nr(right
, push_items
- 1),
3657 old_left_nritems
= btrfs_header_nritems(left
);
3658 BUG_ON(old_left_nritems
<= 0);
3660 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
3661 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
3664 item
= btrfs_item_nr(left
, i
);
3666 ioff
= btrfs_token_item_offset(left
, item
, &token
);
3667 btrfs_set_token_item_offset(left
, item
,
3668 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
),
3671 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
3673 /* fixup right node */
3674 if (push_items
> right_nritems
)
3675 WARN(1, KERN_CRIT
"push items %d nr %u\n", push_items
,
3678 if (push_items
< right_nritems
) {
3679 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
3680 leaf_data_end(root
, right
);
3681 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
3682 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
3683 btrfs_leaf_data(right
) +
3684 leaf_data_end(root
, right
), push_space
);
3686 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
3687 btrfs_item_nr_offset(push_items
),
3688 (btrfs_header_nritems(right
) - push_items
) *
3689 sizeof(struct btrfs_item
));
3691 right_nritems
-= push_items
;
3692 btrfs_set_header_nritems(right
, right_nritems
);
3693 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
3694 for (i
= 0; i
< right_nritems
; i
++) {
3695 item
= btrfs_item_nr(right
, i
);
3697 push_space
= push_space
- btrfs_token_item_size(right
,
3699 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
3702 btrfs_mark_buffer_dirty(left
);
3704 btrfs_mark_buffer_dirty(right
);
3706 clean_tree_block(trans
, root
, right
);
3708 btrfs_item_key(right
, &disk_key
, 0);
3709 fixup_low_keys(root
, path
, &disk_key
, 1);
3711 /* then fixup the leaf pointer in the path */
3712 if (path
->slots
[0] < push_items
) {
3713 path
->slots
[0] += old_left_nritems
;
3714 btrfs_tree_unlock(path
->nodes
[0]);
3715 free_extent_buffer(path
->nodes
[0]);
3716 path
->nodes
[0] = left
;
3717 path
->slots
[1] -= 1;
3719 btrfs_tree_unlock(left
);
3720 free_extent_buffer(left
);
3721 path
->slots
[0] -= push_items
;
3723 BUG_ON(path
->slots
[0] < 0);
3726 btrfs_tree_unlock(left
);
3727 free_extent_buffer(left
);
3732 * push some data in the path leaf to the left, trying to free up at
3733 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3735 * max_slot can put a limit on how far into the leaf we'll push items. The
3736 * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
3739 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
3740 *root
, struct btrfs_path
*path
, int min_data_size
,
3741 int data_size
, int empty
, u32 max_slot
)
3743 struct extent_buffer
*right
= path
->nodes
[0];
3744 struct extent_buffer
*left
;
3750 slot
= path
->slots
[1];
3753 if (!path
->nodes
[1])
3756 right_nritems
= btrfs_header_nritems(right
);
3757 if (right_nritems
== 0)
3760 btrfs_assert_tree_locked(path
->nodes
[1]);
3762 left
= read_node_slot(root
, path
->nodes
[1], slot
- 1);
3766 btrfs_tree_lock(left
);
3767 btrfs_set_lock_blocking(left
);
3769 free_space
= btrfs_leaf_free_space(root
, left
);
3770 if (free_space
< data_size
) {
3775 /* cow and double check */
3776 ret
= btrfs_cow_block(trans
, root
, left
,
3777 path
->nodes
[1], slot
- 1, &left
);
3779 /* we hit -ENOSPC, but it isn't fatal here */
3785 free_space
= btrfs_leaf_free_space(root
, left
);
3786 if (free_space
< data_size
) {
3791 return __push_leaf_left(trans
, root
, path
, min_data_size
,
3792 empty
, left
, free_space
, right_nritems
,
3795 btrfs_tree_unlock(left
);
3796 free_extent_buffer(left
);
3801 * split the path's leaf in two, making sure there is at least data_size
3802 * available for the resulting leaf level of the path.
3804 static noinline
void copy_for_split(struct btrfs_trans_handle
*trans
,
3805 struct btrfs_root
*root
,
3806 struct btrfs_path
*path
,
3807 struct extent_buffer
*l
,
3808 struct extent_buffer
*right
,
3809 int slot
, int mid
, int nritems
)
3814 struct btrfs_disk_key disk_key
;
3815 struct btrfs_map_token token
;
3817 btrfs_init_map_token(&token
);
3819 nritems
= nritems
- mid
;
3820 btrfs_set_header_nritems(right
, nritems
);
3821 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
3823 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
3824 btrfs_item_nr_offset(mid
),
3825 nritems
* sizeof(struct btrfs_item
));
3827 copy_extent_buffer(right
, l
,
3828 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
3829 data_copy_size
, btrfs_leaf_data(l
) +
3830 leaf_data_end(root
, l
), data_copy_size
);
3832 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
3833 btrfs_item_end_nr(l
, mid
);
3835 for (i
= 0; i
< nritems
; i
++) {
3836 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
3839 ioff
= btrfs_token_item_offset(right
, item
, &token
);
3840 btrfs_set_token_item_offset(right
, item
,
3841 ioff
+ rt_data_off
, &token
);
3844 btrfs_set_header_nritems(l
, mid
);
3845 btrfs_item_key(right
, &disk_key
, 0);
3846 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
3847 path
->slots
[1] + 1, 1);
3849 btrfs_mark_buffer_dirty(right
);
3850 btrfs_mark_buffer_dirty(l
);
3851 BUG_ON(path
->slots
[0] != slot
);
3854 btrfs_tree_unlock(path
->nodes
[0]);
3855 free_extent_buffer(path
->nodes
[0]);
3856 path
->nodes
[0] = right
;
3857 path
->slots
[0] -= mid
;
3858 path
->slots
[1] += 1;
3860 btrfs_tree_unlock(right
);
3861 free_extent_buffer(right
);
3864 BUG_ON(path
->slots
[0] < 0);
3868 * double splits happen when we need to insert a big item in the middle
3869 * of a leaf. A double split can leave us with 3 mostly empty leaves:
3870 * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
3873 * We avoid this by trying to push the items on either side of our target
3874 * into the adjacent leaves. If all goes well we can avoid the double split
3877 static noinline
int push_for_double_split(struct btrfs_trans_handle
*trans
,
3878 struct btrfs_root
*root
,
3879 struct btrfs_path
*path
,
3887 slot
= path
->slots
[0];
3890 * try to push all the items after our slot into the
3893 ret
= push_leaf_right(trans
, root
, path
, 1, data_size
, 0, slot
);
3900 nritems
= btrfs_header_nritems(path
->nodes
[0]);
3902 * our goal is to get our slot at the start or end of a leaf. If
3903 * we've done so we're done
3905 if (path
->slots
[0] == 0 || path
->slots
[0] == nritems
)
3908 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
3911 /* try to push all the items before our slot into the next leaf */
3912 slot
= path
->slots
[0];
3913 ret
= push_leaf_left(trans
, root
, path
, 1, data_size
, 0, slot
);
3926 * split the path's leaf in two, making sure there is at least data_size
3927 * available for the resulting leaf level of the path.
3929 * returns 0 if all went well and < 0 on failure.
3931 static noinline
int split_leaf(struct btrfs_trans_handle
*trans
,
3932 struct btrfs_root
*root
,
3933 struct btrfs_key
*ins_key
,
3934 struct btrfs_path
*path
, int data_size
,
3937 struct btrfs_disk_key disk_key
;
3938 struct extent_buffer
*l
;
3942 struct extent_buffer
*right
;
3946 int num_doubles
= 0;
3947 int tried_avoid_double
= 0;
3950 slot
= path
->slots
[0];
3951 if (extend
&& data_size
+ btrfs_item_size_nr(l
, slot
) +
3952 sizeof(struct btrfs_item
) > BTRFS_LEAF_DATA_SIZE(root
))
3955 /* first try to make some room by pushing left and right */
3956 if (data_size
&& path
->nodes
[1]) {
3957 wret
= push_leaf_right(trans
, root
, path
, data_size
,
3962 wret
= push_leaf_left(trans
, root
, path
, data_size
,
3963 data_size
, 0, (u32
)-1);
3969 /* did the pushes work? */
3970 if (btrfs_leaf_free_space(root
, l
) >= data_size
)
3974 if (!path
->nodes
[1]) {
3975 ret
= insert_new_root(trans
, root
, path
, 1);
3982 slot
= path
->slots
[0];
3983 nritems
= btrfs_header_nritems(l
);
3984 mid
= (nritems
+ 1) / 2;
3988 leaf_space_used(l
, mid
, nritems
- mid
) + data_size
>
3989 BTRFS_LEAF_DATA_SIZE(root
)) {
3990 if (slot
>= nritems
) {
3994 if (mid
!= nritems
&&
3995 leaf_space_used(l
, mid
, nritems
- mid
) +
3996 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
3997 if (data_size
&& !tried_avoid_double
)
3998 goto push_for_double
;
4004 if (leaf_space_used(l
, 0, mid
) + data_size
>
4005 BTRFS_LEAF_DATA_SIZE(root
)) {
4006 if (!extend
&& data_size
&& slot
== 0) {
4008 } else if ((extend
|| !data_size
) && slot
== 0) {
4012 if (mid
!= nritems
&&
4013 leaf_space_used(l
, mid
, nritems
- mid
) +
4014 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
4015 if (data_size
&& !tried_avoid_double
)
4016 goto push_for_double
;
4024 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
4026 btrfs_item_key(l
, &disk_key
, mid
);
4028 right
= btrfs_alloc_free_block(trans
, root
, root
->leafsize
, 0,
4029 root
->root_key
.objectid
,
4030 &disk_key
, 0, l
->start
, 0);
4032 return PTR_ERR(right
);
4034 root_add_used(root
, root
->leafsize
);
4036 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
4037 btrfs_set_header_bytenr(right
, right
->start
);
4038 btrfs_set_header_generation(right
, trans
->transid
);
4039 btrfs_set_header_backref_rev(right
, BTRFS_MIXED_BACKREF_REV
);
4040 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
4041 btrfs_set_header_level(right
, 0);
4042 write_extent_buffer(right
, root
->fs_info
->fsid
,
4043 (unsigned long)btrfs_header_fsid(right
),
4046 write_extent_buffer(right
, root
->fs_info
->chunk_tree_uuid
,
4047 (unsigned long)btrfs_header_chunk_tree_uuid(right
),
4052 btrfs_set_header_nritems(right
, 0);
4053 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
4054 path
->slots
[1] + 1, 1);
4055 btrfs_tree_unlock(path
->nodes
[0]);
4056 free_extent_buffer(path
->nodes
[0]);
4057 path
->nodes
[0] = right
;
4059 path
->slots
[1] += 1;
4061 btrfs_set_header_nritems(right
, 0);
4062 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
4064 btrfs_tree_unlock(path
->nodes
[0]);
4065 free_extent_buffer(path
->nodes
[0]);
4066 path
->nodes
[0] = right
;
4068 if (path
->slots
[1] == 0)
4069 fixup_low_keys(root
, path
, &disk_key
, 1);
4071 btrfs_mark_buffer_dirty(right
);
4075 copy_for_split(trans
, root
, path
, l
, right
, slot
, mid
, nritems
);
4078 BUG_ON(num_doubles
!= 0);
4086 push_for_double_split(trans
, root
, path
, data_size
);
4087 tried_avoid_double
= 1;
4088 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
4093 static noinline
int setup_leaf_for_split(struct btrfs_trans_handle
*trans
,
4094 struct btrfs_root
*root
,
4095 struct btrfs_path
*path
, int ins_len
)
4097 struct btrfs_key key
;
4098 struct extent_buffer
*leaf
;
4099 struct btrfs_file_extent_item
*fi
;
4104 leaf
= path
->nodes
[0];
4105 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4107 BUG_ON(key
.type
!= BTRFS_EXTENT_DATA_KEY
&&
4108 key
.type
!= BTRFS_EXTENT_CSUM_KEY
);
4110 if (btrfs_leaf_free_space(root
, leaf
) >= ins_len
)
4113 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
4114 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
4115 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
4116 struct btrfs_file_extent_item
);
4117 extent_len
= btrfs_file_extent_num_bytes(leaf
, fi
);
4119 btrfs_release_path(path
);
4121 path
->keep_locks
= 1;
4122 path
->search_for_split
= 1;
4123 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
4124 path
->search_for_split
= 0;
4129 leaf
= path
->nodes
[0];
4130 /* if our item isn't there or got smaller, return now */
4131 if (ret
> 0 || item_size
!= btrfs_item_size_nr(leaf
, path
->slots
[0]))
4134 /* the leaf has changed, it now has room. return now */
4135 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= ins_len
)
4138 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
4139 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
4140 struct btrfs_file_extent_item
);
4141 if (extent_len
!= btrfs_file_extent_num_bytes(leaf
, fi
))
4145 btrfs_set_path_blocking(path
);
4146 ret
= split_leaf(trans
, root
, &key
, path
, ins_len
, 1);
4150 path
->keep_locks
= 0;
4151 btrfs_unlock_up_safe(path
, 1);
4154 path
->keep_locks
= 0;
4158 static noinline
int split_item(struct btrfs_trans_handle
*trans
,
4159 struct btrfs_root
*root
,
4160 struct btrfs_path
*path
,
4161 struct btrfs_key
*new_key
,
4162 unsigned long split_offset
)
4164 struct extent_buffer
*leaf
;
4165 struct btrfs_item
*item
;
4166 struct btrfs_item
*new_item
;
4172 struct btrfs_disk_key disk_key
;
4174 leaf
= path
->nodes
[0];
4175 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < sizeof(struct btrfs_item
));
4177 btrfs_set_path_blocking(path
);
4179 item
= btrfs_item_nr(leaf
, path
->slots
[0]);
4180 orig_offset
= btrfs_item_offset(leaf
, item
);
4181 item_size
= btrfs_item_size(leaf
, item
);
4183 buf
= kmalloc(item_size
, GFP_NOFS
);
4187 read_extent_buffer(leaf
, buf
, btrfs_item_ptr_offset(leaf
,
4188 path
->slots
[0]), item_size
);
4190 slot
= path
->slots
[0] + 1;
4191 nritems
= btrfs_header_nritems(leaf
);
4192 if (slot
!= nritems
) {
4193 /* shift the items */
4194 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ 1),
4195 btrfs_item_nr_offset(slot
),
4196 (nritems
- slot
) * sizeof(struct btrfs_item
));
4199 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
4200 btrfs_set_item_key(leaf
, &disk_key
, slot
);
4202 new_item
= btrfs_item_nr(leaf
, slot
);
4204 btrfs_set_item_offset(leaf
, new_item
, orig_offset
);
4205 btrfs_set_item_size(leaf
, new_item
, item_size
- split_offset
);
4207 btrfs_set_item_offset(leaf
, item
,
4208 orig_offset
+ item_size
- split_offset
);
4209 btrfs_set_item_size(leaf
, item
, split_offset
);
4211 btrfs_set_header_nritems(leaf
, nritems
+ 1);
4213 /* write the data for the start of the original item */
4214 write_extent_buffer(leaf
, buf
,
4215 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
4218 /* write the data for the new item */
4219 write_extent_buffer(leaf
, buf
+ split_offset
,
4220 btrfs_item_ptr_offset(leaf
, slot
),
4221 item_size
- split_offset
);
4222 btrfs_mark_buffer_dirty(leaf
);
4224 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
4230 * This function splits a single item into two items,
4231 * giving 'new_key' to the new item and splitting the
4232 * old one at split_offset (from the start of the item).
4234 * The path may be released by this operation. After
4235 * the split, the path is pointing to the old item. The
4236 * new item is going to be in the same node as the old one.
4238 * Note, the item being split must be smaller enough to live alone on
4239 * a tree block with room for one extra struct btrfs_item
4241 * This allows us to split the item in place, keeping a lock on the
4242 * leaf the entire time.
4244 int btrfs_split_item(struct btrfs_trans_handle
*trans
,
4245 struct btrfs_root
*root
,
4246 struct btrfs_path
*path
,
4247 struct btrfs_key
*new_key
,
4248 unsigned long split_offset
)
4251 ret
= setup_leaf_for_split(trans
, root
, path
,
4252 sizeof(struct btrfs_item
));
4256 ret
= split_item(trans
, root
, path
, new_key
, split_offset
);
4261 * This function duplicate a item, giving 'new_key' to the new item.
4262 * It guarantees both items live in the same tree leaf and the new item
4263 * is contiguous with the original item.
4265 * This allows us to split file extent in place, keeping a lock on the
4266 * leaf the entire time.
4268 int btrfs_duplicate_item(struct btrfs_trans_handle
*trans
,
4269 struct btrfs_root
*root
,
4270 struct btrfs_path
*path
,
4271 struct btrfs_key
*new_key
)
4273 struct extent_buffer
*leaf
;
4277 leaf
= path
->nodes
[0];
4278 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
4279 ret
= setup_leaf_for_split(trans
, root
, path
,
4280 item_size
+ sizeof(struct btrfs_item
));
4285 setup_items_for_insert(root
, path
, new_key
, &item_size
,
4286 item_size
, item_size
+
4287 sizeof(struct btrfs_item
), 1);
4288 leaf
= path
->nodes
[0];
4289 memcpy_extent_buffer(leaf
,
4290 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
4291 btrfs_item_ptr_offset(leaf
, path
->slots
[0] - 1),
4297 * make the item pointed to by the path smaller. new_size indicates
4298 * how small to make it, and from_end tells us if we just chop bytes
4299 * off the end of the item or if we shift the item to chop bytes off
4302 void btrfs_truncate_item(struct btrfs_root
*root
, struct btrfs_path
*path
,
4303 u32 new_size
, int from_end
)
4306 struct extent_buffer
*leaf
;
4307 struct btrfs_item
*item
;
4309 unsigned int data_end
;
4310 unsigned int old_data_start
;
4311 unsigned int old_size
;
4312 unsigned int size_diff
;
4314 struct btrfs_map_token token
;
4316 btrfs_init_map_token(&token
);
4318 leaf
= path
->nodes
[0];
4319 slot
= path
->slots
[0];
4321 old_size
= btrfs_item_size_nr(leaf
, slot
);
4322 if (old_size
== new_size
)
4325 nritems
= btrfs_header_nritems(leaf
);
4326 data_end
= leaf_data_end(root
, leaf
);
4328 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
4330 size_diff
= old_size
- new_size
;
4333 BUG_ON(slot
>= nritems
);
4336 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4338 /* first correct the data pointers */
4339 for (i
= slot
; i
< nritems
; i
++) {
4341 item
= btrfs_item_nr(leaf
, i
);
4343 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4344 btrfs_set_token_item_offset(leaf
, item
,
4345 ioff
+ size_diff
, &token
);
4348 /* shift the data */
4350 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4351 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
4352 data_end
, old_data_start
+ new_size
- data_end
);
4354 struct btrfs_disk_key disk_key
;
4357 btrfs_item_key(leaf
, &disk_key
, slot
);
4359 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
4361 struct btrfs_file_extent_item
*fi
;
4363 fi
= btrfs_item_ptr(leaf
, slot
,
4364 struct btrfs_file_extent_item
);
4365 fi
= (struct btrfs_file_extent_item
*)(
4366 (unsigned long)fi
- size_diff
);
4368 if (btrfs_file_extent_type(leaf
, fi
) ==
4369 BTRFS_FILE_EXTENT_INLINE
) {
4370 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
4371 memmove_extent_buffer(leaf
, ptr
,
4373 offsetof(struct btrfs_file_extent_item
,
4378 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4379 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
4380 data_end
, old_data_start
- data_end
);
4382 offset
= btrfs_disk_key_offset(&disk_key
);
4383 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
4384 btrfs_set_item_key(leaf
, &disk_key
, slot
);
4386 fixup_low_keys(root
, path
, &disk_key
, 1);
4389 item
= btrfs_item_nr(leaf
, slot
);
4390 btrfs_set_item_size(leaf
, item
, new_size
);
4391 btrfs_mark_buffer_dirty(leaf
);
4393 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4394 btrfs_print_leaf(root
, leaf
);
4400 * make the item pointed to by the path bigger, data_size is the added size.
4402 void btrfs_extend_item(struct btrfs_root
*root
, struct btrfs_path
*path
,
4406 struct extent_buffer
*leaf
;
4407 struct btrfs_item
*item
;
4409 unsigned int data_end
;
4410 unsigned int old_data
;
4411 unsigned int old_size
;
4413 struct btrfs_map_token token
;
4415 btrfs_init_map_token(&token
);
4417 leaf
= path
->nodes
[0];
4419 nritems
= btrfs_header_nritems(leaf
);
4420 data_end
= leaf_data_end(root
, leaf
);
4422 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
4423 btrfs_print_leaf(root
, leaf
);
4426 slot
= path
->slots
[0];
4427 old_data
= btrfs_item_end_nr(leaf
, slot
);
4430 if (slot
>= nritems
) {
4431 btrfs_print_leaf(root
, leaf
);
4432 printk(KERN_CRIT
"slot %d too large, nritems %d\n",
4438 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4440 /* first correct the data pointers */
4441 for (i
= slot
; i
< nritems
; i
++) {
4443 item
= btrfs_item_nr(leaf
, i
);
4445 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4446 btrfs_set_token_item_offset(leaf
, item
,
4447 ioff
- data_size
, &token
);
4450 /* shift the data */
4451 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4452 data_end
- data_size
, btrfs_leaf_data(leaf
) +
4453 data_end
, old_data
- data_end
);
4455 data_end
= old_data
;
4456 old_size
= btrfs_item_size_nr(leaf
, slot
);
4457 item
= btrfs_item_nr(leaf
, slot
);
4458 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
4459 btrfs_mark_buffer_dirty(leaf
);
4461 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4462 btrfs_print_leaf(root
, leaf
);
4468 * this is a helper for btrfs_insert_empty_items, the main goal here is
4469 * to save stack depth by doing the bulk of the work in a function
4470 * that doesn't call btrfs_search_slot
4472 void setup_items_for_insert(struct btrfs_root
*root
, struct btrfs_path
*path
,
4473 struct btrfs_key
*cpu_key
, u32
*data_size
,
4474 u32 total_data
, u32 total_size
, int nr
)
4476 struct btrfs_item
*item
;
4479 unsigned int data_end
;
4480 struct btrfs_disk_key disk_key
;
4481 struct extent_buffer
*leaf
;
4483 struct btrfs_map_token token
;
4485 btrfs_init_map_token(&token
);
4487 leaf
= path
->nodes
[0];
4488 slot
= path
->slots
[0];
4490 nritems
= btrfs_header_nritems(leaf
);
4491 data_end
= leaf_data_end(root
, leaf
);
4493 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
4494 btrfs_print_leaf(root
, leaf
);
4495 printk(KERN_CRIT
"not enough freespace need %u have %d\n",
4496 total_size
, btrfs_leaf_free_space(root
, leaf
));
4500 if (slot
!= nritems
) {
4501 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
4503 if (old_data
< data_end
) {
4504 btrfs_print_leaf(root
, leaf
);
4505 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
4506 slot
, old_data
, data_end
);
4510 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4512 /* first correct the data pointers */
4513 for (i
= slot
; i
< nritems
; i
++) {
4516 item
= btrfs_item_nr(leaf
, i
);
4517 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4518 btrfs_set_token_item_offset(leaf
, item
,
4519 ioff
- total_data
, &token
);
4521 /* shift the items */
4522 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
4523 btrfs_item_nr_offset(slot
),
4524 (nritems
- slot
) * sizeof(struct btrfs_item
));
4526 /* shift the data */
4527 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4528 data_end
- total_data
, btrfs_leaf_data(leaf
) +
4529 data_end
, old_data
- data_end
);
4530 data_end
= old_data
;
4533 /* setup the item for the new data */
4534 for (i
= 0; i
< nr
; i
++) {
4535 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
4536 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
4537 item
= btrfs_item_nr(leaf
, slot
+ i
);
4538 btrfs_set_token_item_offset(leaf
, item
,
4539 data_end
- data_size
[i
], &token
);
4540 data_end
-= data_size
[i
];
4541 btrfs_set_token_item_size(leaf
, item
, data_size
[i
], &token
);
4544 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
4547 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
4548 fixup_low_keys(root
, path
, &disk_key
, 1);
4550 btrfs_unlock_up_safe(path
, 1);
4551 btrfs_mark_buffer_dirty(leaf
);
4553 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4554 btrfs_print_leaf(root
, leaf
);
4560 * Given a key and some data, insert items into the tree.
4561 * This does all the path init required, making room in the tree if needed.
4563 int btrfs_insert_empty_items(struct btrfs_trans_handle
*trans
,
4564 struct btrfs_root
*root
,
4565 struct btrfs_path
*path
,
4566 struct btrfs_key
*cpu_key
, u32
*data_size
,
4575 for (i
= 0; i
< nr
; i
++)
4576 total_data
+= data_size
[i
];
4578 total_size
= total_data
+ (nr
* sizeof(struct btrfs_item
));
4579 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
4585 slot
= path
->slots
[0];
4588 setup_items_for_insert(root
, path
, cpu_key
, data_size
,
4589 total_data
, total_size
, nr
);
4594 * Given a key and some data, insert an item into the tree.
4595 * This does all the path init required, making room in the tree if needed.
4597 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
4598 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
4602 struct btrfs_path
*path
;
4603 struct extent_buffer
*leaf
;
4606 path
= btrfs_alloc_path();
4609 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
4611 leaf
= path
->nodes
[0];
4612 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
4613 write_extent_buffer(leaf
, data
, ptr
, data_size
);
4614 btrfs_mark_buffer_dirty(leaf
);
4616 btrfs_free_path(path
);
4621 * delete the pointer from a given node.
4623 * the tree should have been previously balanced so the deletion does not
4626 static void del_ptr(struct btrfs_root
*root
, struct btrfs_path
*path
,
4627 int level
, int slot
)
4629 struct extent_buffer
*parent
= path
->nodes
[level
];
4633 nritems
= btrfs_header_nritems(parent
);
4634 if (slot
!= nritems
- 1) {
4636 tree_mod_log_eb_move(root
->fs_info
, parent
, slot
,
4637 slot
+ 1, nritems
- slot
- 1);
4638 memmove_extent_buffer(parent
,
4639 btrfs_node_key_ptr_offset(slot
),
4640 btrfs_node_key_ptr_offset(slot
+ 1),
4641 sizeof(struct btrfs_key_ptr
) *
4642 (nritems
- slot
- 1));
4644 ret
= tree_mod_log_insert_key(root
->fs_info
, parent
, slot
,
4645 MOD_LOG_KEY_REMOVE
);
4650 btrfs_set_header_nritems(parent
, nritems
);
4651 if (nritems
== 0 && parent
== root
->node
) {
4652 BUG_ON(btrfs_header_level(root
->node
) != 1);
4653 /* just turn the root into a leaf and break */
4654 btrfs_set_header_level(root
->node
, 0);
4655 } else if (slot
== 0) {
4656 struct btrfs_disk_key disk_key
;
4658 btrfs_node_key(parent
, &disk_key
, 0);
4659 fixup_low_keys(root
, path
, &disk_key
, level
+ 1);
4661 btrfs_mark_buffer_dirty(parent
);
4665 * a helper function to delete the leaf pointed to by path->slots[1] and
4668 * This deletes the pointer in path->nodes[1] and frees the leaf
4669 * block extent. zero is returned if it all worked out, < 0 otherwise.
4671 * The path must have already been setup for deleting the leaf, including
4672 * all the proper balancing. path->nodes[1] must be locked.
4674 static noinline
void btrfs_del_leaf(struct btrfs_trans_handle
*trans
,
4675 struct btrfs_root
*root
,
4676 struct btrfs_path
*path
,
4677 struct extent_buffer
*leaf
)
4679 WARN_ON(btrfs_header_generation(leaf
) != trans
->transid
);
4680 del_ptr(root
, path
, 1, path
->slots
[1]);
4683 * btrfs_free_extent is expensive, we want to make sure we
4684 * aren't holding any locks when we call it
4686 btrfs_unlock_up_safe(path
, 0);
4688 root_sub_used(root
, leaf
->len
);
4690 extent_buffer_get(leaf
);
4691 btrfs_free_tree_block(trans
, root
, leaf
, 0, 1);
4692 free_extent_buffer_stale(leaf
);
4695 * delete the item at the leaf level in path. If that empties
4696 * the leaf, remove it from the tree
4698 int btrfs_del_items(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
4699 struct btrfs_path
*path
, int slot
, int nr
)
4701 struct extent_buffer
*leaf
;
4702 struct btrfs_item
*item
;
4709 struct btrfs_map_token token
;
4711 btrfs_init_map_token(&token
);
4713 leaf
= path
->nodes
[0];
4714 last_off
= btrfs_item_offset_nr(leaf
, slot
+ nr
- 1);
4716 for (i
= 0; i
< nr
; i
++)
4717 dsize
+= btrfs_item_size_nr(leaf
, slot
+ i
);
4719 nritems
= btrfs_header_nritems(leaf
);
4721 if (slot
+ nr
!= nritems
) {
4722 int data_end
= leaf_data_end(root
, leaf
);
4724 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4726 btrfs_leaf_data(leaf
) + data_end
,
4727 last_off
- data_end
);
4729 for (i
= slot
+ nr
; i
< nritems
; i
++) {
4732 item
= btrfs_item_nr(leaf
, i
);
4733 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4734 btrfs_set_token_item_offset(leaf
, item
,
4735 ioff
+ dsize
, &token
);
4738 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
4739 btrfs_item_nr_offset(slot
+ nr
),
4740 sizeof(struct btrfs_item
) *
4741 (nritems
- slot
- nr
));
4743 btrfs_set_header_nritems(leaf
, nritems
- nr
);
4746 /* delete the leaf if we've emptied it */
4748 if (leaf
== root
->node
) {
4749 btrfs_set_header_level(leaf
, 0);
4751 btrfs_set_path_blocking(path
);
4752 clean_tree_block(trans
, root
, leaf
);
4753 btrfs_del_leaf(trans
, root
, path
, leaf
);
4756 int used
= leaf_space_used(leaf
, 0, nritems
);
4758 struct btrfs_disk_key disk_key
;
4760 btrfs_item_key(leaf
, &disk_key
, 0);
4761 fixup_low_keys(root
, path
, &disk_key
, 1);
4764 /* delete the leaf if it is mostly empty */
4765 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
4766 /* push_leaf_left fixes the path.
4767 * make sure the path still points to our leaf
4768 * for possible call to del_ptr below
4770 slot
= path
->slots
[1];
4771 extent_buffer_get(leaf
);
4773 btrfs_set_path_blocking(path
);
4774 wret
= push_leaf_left(trans
, root
, path
, 1, 1,
4776 if (wret
< 0 && wret
!= -ENOSPC
)
4779 if (path
->nodes
[0] == leaf
&&
4780 btrfs_header_nritems(leaf
)) {
4781 wret
= push_leaf_right(trans
, root
, path
, 1,
4783 if (wret
< 0 && wret
!= -ENOSPC
)
4787 if (btrfs_header_nritems(leaf
) == 0) {
4788 path
->slots
[1] = slot
;
4789 btrfs_del_leaf(trans
, root
, path
, leaf
);
4790 free_extent_buffer(leaf
);
4793 /* if we're still in the path, make sure
4794 * we're dirty. Otherwise, one of the
4795 * push_leaf functions must have already
4796 * dirtied this buffer
4798 if (path
->nodes
[0] == leaf
)
4799 btrfs_mark_buffer_dirty(leaf
);
4800 free_extent_buffer(leaf
);
4803 btrfs_mark_buffer_dirty(leaf
);
4810 * search the tree again to find a leaf with lesser keys
4811 * returns 0 if it found something or 1 if there are no lesser leaves.
4812 * returns < 0 on io errors.
4814 * This may release the path, and so you may lose any locks held at the
4817 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
4819 struct btrfs_key key
;
4820 struct btrfs_disk_key found_key
;
4823 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, 0);
4827 else if (key
.type
> 0)
4829 else if (key
.objectid
> 0)
4834 btrfs_release_path(path
);
4835 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
4838 btrfs_item_key(path
->nodes
[0], &found_key
, 0);
4839 ret
= comp_keys(&found_key
, &key
);
4846 * A helper function to walk down the tree starting at min_key, and looking
4847 * for nodes or leaves that are have a minimum transaction id.
4848 * This is used by the btree defrag code, and tree logging
4850 * This does not cow, but it does stuff the starting key it finds back
4851 * into min_key, so you can call btrfs_search_slot with cow=1 on the
4852 * key and get a writable path.
4854 * This does lock as it descends, and path->keep_locks should be set
4855 * to 1 by the caller.
4857 * This honors path->lowest_level to prevent descent past a given level
4860 * min_trans indicates the oldest transaction that you are interested
4861 * in walking through. Any nodes or leaves older than min_trans are
4862 * skipped over (without reading them).
4864 * returns zero if something useful was found, < 0 on error and 1 if there
4865 * was nothing in the tree that matched the search criteria.
4867 int btrfs_search_forward(struct btrfs_root
*root
, struct btrfs_key
*min_key
,
4868 struct btrfs_key
*max_key
,
4869 struct btrfs_path
*path
,
4872 struct extent_buffer
*cur
;
4873 struct btrfs_key found_key
;
4880 WARN_ON(!path
->keep_locks
);
4882 cur
= btrfs_read_lock_root_node(root
);
4883 level
= btrfs_header_level(cur
);
4884 WARN_ON(path
->nodes
[level
]);
4885 path
->nodes
[level
] = cur
;
4886 path
->locks
[level
] = BTRFS_READ_LOCK
;
4888 if (btrfs_header_generation(cur
) < min_trans
) {
4893 nritems
= btrfs_header_nritems(cur
);
4894 level
= btrfs_header_level(cur
);
4895 sret
= bin_search(cur
, min_key
, level
, &slot
);
4897 /* at the lowest level, we're done, setup the path and exit */
4898 if (level
== path
->lowest_level
) {
4899 if (slot
>= nritems
)
4902 path
->slots
[level
] = slot
;
4903 btrfs_item_key_to_cpu(cur
, &found_key
, slot
);
4906 if (sret
&& slot
> 0)
4909 * check this node pointer against the min_trans parameters.
4910 * If it is too old, old, skip to the next one.
4912 while (slot
< nritems
) {
4916 blockptr
= btrfs_node_blockptr(cur
, slot
);
4917 gen
= btrfs_node_ptr_generation(cur
, slot
);
4918 if (gen
< min_trans
) {
4926 * we didn't find a candidate key in this node, walk forward
4927 * and find another one
4929 if (slot
>= nritems
) {
4930 path
->slots
[level
] = slot
;
4931 btrfs_set_path_blocking(path
);
4932 sret
= btrfs_find_next_key(root
, path
, min_key
, level
,
4935 btrfs_release_path(path
);
4941 /* save our key for returning back */
4942 btrfs_node_key_to_cpu(cur
, &found_key
, slot
);
4943 path
->slots
[level
] = slot
;
4944 if (level
== path
->lowest_level
) {
4946 unlock_up(path
, level
, 1, 0, NULL
);
4949 btrfs_set_path_blocking(path
);
4950 cur
= read_node_slot(root
, cur
, slot
);
4951 BUG_ON(!cur
); /* -ENOMEM */
4953 btrfs_tree_read_lock(cur
);
4955 path
->locks
[level
- 1] = BTRFS_READ_LOCK
;
4956 path
->nodes
[level
- 1] = cur
;
4957 unlock_up(path
, level
, 1, 0, NULL
);
4958 btrfs_clear_path_blocking(path
, NULL
, 0);
4962 memcpy(min_key
, &found_key
, sizeof(found_key
));
4963 btrfs_set_path_blocking(path
);
4967 static void tree_move_down(struct btrfs_root
*root
,
4968 struct btrfs_path
*path
,
4969 int *level
, int root_level
)
4971 BUG_ON(*level
== 0);
4972 path
->nodes
[*level
- 1] = read_node_slot(root
, path
->nodes
[*level
],
4973 path
->slots
[*level
]);
4974 path
->slots
[*level
- 1] = 0;
4978 static int tree_move_next_or_upnext(struct btrfs_root
*root
,
4979 struct btrfs_path
*path
,
4980 int *level
, int root_level
)
4984 nritems
= btrfs_header_nritems(path
->nodes
[*level
]);
4986 path
->slots
[*level
]++;
4988 while (path
->slots
[*level
] >= nritems
) {
4989 if (*level
== root_level
)
4993 path
->slots
[*level
] = 0;
4994 free_extent_buffer(path
->nodes
[*level
]);
4995 path
->nodes
[*level
] = NULL
;
4997 path
->slots
[*level
]++;
4999 nritems
= btrfs_header_nritems(path
->nodes
[*level
]);
5006 * Returns 1 if it had to move up and next. 0 is returned if it moved only next
5009 static int tree_advance(struct btrfs_root
*root
,
5010 struct btrfs_path
*path
,
5011 int *level
, int root_level
,
5013 struct btrfs_key
*key
)
5017 if (*level
== 0 || !allow_down
) {
5018 ret
= tree_move_next_or_upnext(root
, path
, level
, root_level
);
5020 tree_move_down(root
, path
, level
, root_level
);
5025 btrfs_item_key_to_cpu(path
->nodes
[*level
], key
,
5026 path
->slots
[*level
]);
5028 btrfs_node_key_to_cpu(path
->nodes
[*level
], key
,
5029 path
->slots
[*level
]);
5034 static int tree_compare_item(struct btrfs_root
*left_root
,
5035 struct btrfs_path
*left_path
,
5036 struct btrfs_path
*right_path
,
5041 unsigned long off1
, off2
;
5043 len1
= btrfs_item_size_nr(left_path
->nodes
[0], left_path
->slots
[0]);
5044 len2
= btrfs_item_size_nr(right_path
->nodes
[0], right_path
->slots
[0]);
5048 off1
= btrfs_item_ptr_offset(left_path
->nodes
[0], left_path
->slots
[0]);
5049 off2
= btrfs_item_ptr_offset(right_path
->nodes
[0],
5050 right_path
->slots
[0]);
5052 read_extent_buffer(left_path
->nodes
[0], tmp_buf
, off1
, len1
);
5054 cmp
= memcmp_extent_buffer(right_path
->nodes
[0], tmp_buf
, off2
, len1
);
5061 #define ADVANCE_ONLY_NEXT -1
5064 * This function compares two trees and calls the provided callback for
5065 * every changed/new/deleted item it finds.
5066 * If shared tree blocks are encountered, whole subtrees are skipped, making
5067 * the compare pretty fast on snapshotted subvolumes.
5069 * This currently works on commit roots only. As commit roots are read only,
5070 * we don't do any locking. The commit roots are protected with transactions.
5071 * Transactions are ended and rejoined when a commit is tried in between.
5073 * This function checks for modifications done to the trees while comparing.
5074 * If it detects a change, it aborts immediately.
5076 int btrfs_compare_trees(struct btrfs_root
*left_root
,
5077 struct btrfs_root
*right_root
,
5078 btrfs_changed_cb_t changed_cb
, void *ctx
)
5082 struct btrfs_trans_handle
*trans
= NULL
;
5083 struct btrfs_path
*left_path
= NULL
;
5084 struct btrfs_path
*right_path
= NULL
;
5085 struct btrfs_key left_key
;
5086 struct btrfs_key right_key
;
5087 char *tmp_buf
= NULL
;
5088 int left_root_level
;
5089 int right_root_level
;
5092 int left_end_reached
;
5093 int right_end_reached
;
5098 u64 left_start_ctransid
;
5099 u64 right_start_ctransid
;
5102 left_path
= btrfs_alloc_path();
5107 right_path
= btrfs_alloc_path();
5113 tmp_buf
= kmalloc(left_root
->leafsize
, GFP_NOFS
);
5119 left_path
->search_commit_root
= 1;
5120 left_path
->skip_locking
= 1;
5121 right_path
->search_commit_root
= 1;
5122 right_path
->skip_locking
= 1;
5124 spin_lock(&left_root
->root_item_lock
);
5125 left_start_ctransid
= btrfs_root_ctransid(&left_root
->root_item
);
5126 spin_unlock(&left_root
->root_item_lock
);
5128 spin_lock(&right_root
->root_item_lock
);
5129 right_start_ctransid
= btrfs_root_ctransid(&right_root
->root_item
);
5130 spin_unlock(&right_root
->root_item_lock
);
5132 trans
= btrfs_join_transaction(left_root
);
5133 if (IS_ERR(trans
)) {
5134 ret
= PTR_ERR(trans
);
5140 * Strategy: Go to the first items of both trees. Then do
5142 * If both trees are at level 0
5143 * Compare keys of current items
5144 * If left < right treat left item as new, advance left tree
5146 * If left > right treat right item as deleted, advance right tree
5148 * If left == right do deep compare of items, treat as changed if
5149 * needed, advance both trees and repeat
5150 * If both trees are at the same level but not at level 0
5151 * Compare keys of current nodes/leafs
5152 * If left < right advance left tree and repeat
5153 * If left > right advance right tree and repeat
5154 * If left == right compare blockptrs of the next nodes/leafs
5155 * If they match advance both trees but stay at the same level
5157 * If they don't match advance both trees while allowing to go
5159 * If tree levels are different
5160 * Advance the tree that needs it and repeat
5162 * Advancing a tree means:
5163 * If we are at level 0, try to go to the next slot. If that's not
5164 * possible, go one level up and repeat. Stop when we found a level
5165 * where we could go to the next slot. We may at this point be on a
5168 * If we are not at level 0 and not on shared tree blocks, go one
5171 * If we are not at level 0 and on shared tree blocks, go one slot to
5172 * the right if possible or go up and right.
5175 left_level
= btrfs_header_level(left_root
->commit_root
);
5176 left_root_level
= left_level
;
5177 left_path
->nodes
[left_level
] = left_root
->commit_root
;
5178 extent_buffer_get(left_path
->nodes
[left_level
]);
5180 right_level
= btrfs_header_level(right_root
->commit_root
);
5181 right_root_level
= right_level
;
5182 right_path
->nodes
[right_level
] = right_root
->commit_root
;
5183 extent_buffer_get(right_path
->nodes
[right_level
]);
5185 if (left_level
== 0)
5186 btrfs_item_key_to_cpu(left_path
->nodes
[left_level
],
5187 &left_key
, left_path
->slots
[left_level
]);
5189 btrfs_node_key_to_cpu(left_path
->nodes
[left_level
],
5190 &left_key
, left_path
->slots
[left_level
]);
5191 if (right_level
== 0)
5192 btrfs_item_key_to_cpu(right_path
->nodes
[right_level
],
5193 &right_key
, right_path
->slots
[right_level
]);
5195 btrfs_node_key_to_cpu(right_path
->nodes
[right_level
],
5196 &right_key
, right_path
->slots
[right_level
]);
5198 left_end_reached
= right_end_reached
= 0;
5199 advance_left
= advance_right
= 0;
5203 * We need to make sure the transaction does not get committed
5204 * while we do anything on commit roots. This means, we need to
5205 * join and leave transactions for every item that we process.
5207 if (trans
&& btrfs_should_end_transaction(trans
, left_root
)) {
5208 btrfs_release_path(left_path
);
5209 btrfs_release_path(right_path
);
5211 ret
= btrfs_end_transaction(trans
, left_root
);
5216 /* now rejoin the transaction */
5218 trans
= btrfs_join_transaction(left_root
);
5219 if (IS_ERR(trans
)) {
5220 ret
= PTR_ERR(trans
);
5225 spin_lock(&left_root
->root_item_lock
);
5226 ctransid
= btrfs_root_ctransid(&left_root
->root_item
);
5227 spin_unlock(&left_root
->root_item_lock
);
5228 if (ctransid
!= left_start_ctransid
)
5229 left_start_ctransid
= 0;
5231 spin_lock(&right_root
->root_item_lock
);
5232 ctransid
= btrfs_root_ctransid(&right_root
->root_item
);
5233 spin_unlock(&right_root
->root_item_lock
);
5234 if (ctransid
!= right_start_ctransid
)
5235 right_start_ctransid
= 0;
5237 if (!left_start_ctransid
|| !right_start_ctransid
) {
5238 WARN(1, KERN_WARNING
5239 "btrfs: btrfs_compare_tree detected "
5240 "a change in one of the trees while "
5241 "iterating. This is probably a "
5248 * the commit root may have changed, so start again
5251 left_path
->lowest_level
= left_level
;
5252 right_path
->lowest_level
= right_level
;
5253 ret
= btrfs_search_slot(NULL
, left_root
,
5254 &left_key
, left_path
, 0, 0);
5257 ret
= btrfs_search_slot(NULL
, right_root
,
5258 &right_key
, right_path
, 0, 0);
5263 if (advance_left
&& !left_end_reached
) {
5264 ret
= tree_advance(left_root
, left_path
, &left_level
,
5266 advance_left
!= ADVANCE_ONLY_NEXT
,
5269 left_end_reached
= ADVANCE
;
5272 if (advance_right
&& !right_end_reached
) {
5273 ret
= tree_advance(right_root
, right_path
, &right_level
,
5275 advance_right
!= ADVANCE_ONLY_NEXT
,
5278 right_end_reached
= ADVANCE
;
5282 if (left_end_reached
&& right_end_reached
) {
5285 } else if (left_end_reached
) {
5286 if (right_level
== 0) {
5287 ret
= changed_cb(left_root
, right_root
,
5288 left_path
, right_path
,
5290 BTRFS_COMPARE_TREE_DELETED
,
5295 advance_right
= ADVANCE
;
5297 } else if (right_end_reached
) {
5298 if (left_level
== 0) {
5299 ret
= changed_cb(left_root
, right_root
,
5300 left_path
, right_path
,
5302 BTRFS_COMPARE_TREE_NEW
,
5307 advance_left
= ADVANCE
;
5311 if (left_level
== 0 && right_level
== 0) {
5312 cmp
= btrfs_comp_cpu_keys(&left_key
, &right_key
);
5314 ret
= changed_cb(left_root
, right_root
,
5315 left_path
, right_path
,
5317 BTRFS_COMPARE_TREE_NEW
,
5321 advance_left
= ADVANCE
;
5322 } else if (cmp
> 0) {
5323 ret
= changed_cb(left_root
, right_root
,
5324 left_path
, right_path
,
5326 BTRFS_COMPARE_TREE_DELETED
,
5330 advance_right
= ADVANCE
;
5332 WARN_ON(!extent_buffer_uptodate(left_path
->nodes
[0]));
5333 ret
= tree_compare_item(left_root
, left_path
,
5334 right_path
, tmp_buf
);
5336 WARN_ON(!extent_buffer_uptodate(left_path
->nodes
[0]));
5337 ret
= changed_cb(left_root
, right_root
,
5338 left_path
, right_path
,
5340 BTRFS_COMPARE_TREE_CHANGED
,
5345 advance_left
= ADVANCE
;
5346 advance_right
= ADVANCE
;
5348 } else if (left_level
== right_level
) {
5349 cmp
= btrfs_comp_cpu_keys(&left_key
, &right_key
);
5351 advance_left
= ADVANCE
;
5352 } else if (cmp
> 0) {
5353 advance_right
= ADVANCE
;
5355 left_blockptr
= btrfs_node_blockptr(
5356 left_path
->nodes
[left_level
],
5357 left_path
->slots
[left_level
]);
5358 right_blockptr
= btrfs_node_blockptr(
5359 right_path
->nodes
[right_level
],
5360 right_path
->slots
[right_level
]);
5361 if (left_blockptr
== right_blockptr
) {
5363 * As we're on a shared block, don't
5364 * allow to go deeper.
5366 advance_left
= ADVANCE_ONLY_NEXT
;
5367 advance_right
= ADVANCE_ONLY_NEXT
;
5369 advance_left
= ADVANCE
;
5370 advance_right
= ADVANCE
;
5373 } else if (left_level
< right_level
) {
5374 advance_right
= ADVANCE
;
5376 advance_left
= ADVANCE
;
5381 btrfs_free_path(left_path
);
5382 btrfs_free_path(right_path
);
5387 ret
= btrfs_end_transaction(trans
, left_root
);
5389 btrfs_end_transaction(trans
, left_root
);
5396 * this is similar to btrfs_next_leaf, but does not try to preserve
5397 * and fixup the path. It looks for and returns the next key in the
5398 * tree based on the current path and the min_trans parameters.
5400 * 0 is returned if another key is found, < 0 if there are any errors
5401 * and 1 is returned if there are no higher keys in the tree
5403 * path->keep_locks should be set to 1 on the search made before
5404 * calling this function.
5406 int btrfs_find_next_key(struct btrfs_root
*root
, struct btrfs_path
*path
,
5407 struct btrfs_key
*key
, int level
, u64 min_trans
)
5410 struct extent_buffer
*c
;
5412 WARN_ON(!path
->keep_locks
);
5413 while (level
< BTRFS_MAX_LEVEL
) {
5414 if (!path
->nodes
[level
])
5417 slot
= path
->slots
[level
] + 1;
5418 c
= path
->nodes
[level
];
5420 if (slot
>= btrfs_header_nritems(c
)) {
5423 struct btrfs_key cur_key
;
5424 if (level
+ 1 >= BTRFS_MAX_LEVEL
||
5425 !path
->nodes
[level
+ 1])
5428 if (path
->locks
[level
+ 1]) {
5433 slot
= btrfs_header_nritems(c
) - 1;
5435 btrfs_item_key_to_cpu(c
, &cur_key
, slot
);
5437 btrfs_node_key_to_cpu(c
, &cur_key
, slot
);
5439 orig_lowest
= path
->lowest_level
;
5440 btrfs_release_path(path
);
5441 path
->lowest_level
= level
;
5442 ret
= btrfs_search_slot(NULL
, root
, &cur_key
, path
,
5444 path
->lowest_level
= orig_lowest
;
5448 c
= path
->nodes
[level
];
5449 slot
= path
->slots
[level
];
5456 btrfs_item_key_to_cpu(c
, key
, slot
);
5458 u64 gen
= btrfs_node_ptr_generation(c
, slot
);
5460 if (gen
< min_trans
) {
5464 btrfs_node_key_to_cpu(c
, key
, slot
);
5472 * search the tree again to find a leaf with greater keys
5473 * returns 0 if it found something or 1 if there are no greater leaves.
5474 * returns < 0 on io errors.
5476 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
5478 return btrfs_next_old_leaf(root
, path
, 0);
5481 int btrfs_next_old_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
5486 struct extent_buffer
*c
;
5487 struct extent_buffer
*next
;
5488 struct btrfs_key key
;
5491 int old_spinning
= path
->leave_spinning
;
5492 int next_rw_lock
= 0;
5494 nritems
= btrfs_header_nritems(path
->nodes
[0]);
5498 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, nritems
- 1);
5503 btrfs_release_path(path
);
5505 path
->keep_locks
= 1;
5506 path
->leave_spinning
= 1;
5509 ret
= btrfs_search_old_slot(root
, &key
, path
, time_seq
);
5511 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
5512 path
->keep_locks
= 0;
5517 nritems
= btrfs_header_nritems(path
->nodes
[0]);
5519 * by releasing the path above we dropped all our locks. A balance
5520 * could have added more items next to the key that used to be
5521 * at the very end of the block. So, check again here and
5522 * advance the path if there are now more items available.
5524 if (nritems
> 0 && path
->slots
[0] < nritems
- 1) {
5531 while (level
< BTRFS_MAX_LEVEL
) {
5532 if (!path
->nodes
[level
]) {
5537 slot
= path
->slots
[level
] + 1;
5538 c
= path
->nodes
[level
];
5539 if (slot
>= btrfs_header_nritems(c
)) {
5541 if (level
== BTRFS_MAX_LEVEL
) {
5549 btrfs_tree_unlock_rw(next
, next_rw_lock
);
5550 free_extent_buffer(next
);
5554 next_rw_lock
= path
->locks
[level
];
5555 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
5561 btrfs_release_path(path
);
5565 if (!path
->skip_locking
) {
5566 ret
= btrfs_try_tree_read_lock(next
);
5567 if (!ret
&& time_seq
) {
5569 * If we don't get the lock, we may be racing
5570 * with push_leaf_left, holding that lock while
5571 * itself waiting for the leaf we've currently
5572 * locked. To solve this situation, we give up
5573 * on our lock and cycle.
5575 free_extent_buffer(next
);
5576 btrfs_release_path(path
);
5581 btrfs_set_path_blocking(path
);
5582 btrfs_tree_read_lock(next
);
5583 btrfs_clear_path_blocking(path
, next
,
5586 next_rw_lock
= BTRFS_READ_LOCK
;
5590 path
->slots
[level
] = slot
;
5593 c
= path
->nodes
[level
];
5594 if (path
->locks
[level
])
5595 btrfs_tree_unlock_rw(c
, path
->locks
[level
]);
5597 free_extent_buffer(c
);
5598 path
->nodes
[level
] = next
;
5599 path
->slots
[level
] = 0;
5600 if (!path
->skip_locking
)
5601 path
->locks
[level
] = next_rw_lock
;
5605 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
5611 btrfs_release_path(path
);
5615 if (!path
->skip_locking
) {
5616 ret
= btrfs_try_tree_read_lock(next
);
5618 btrfs_set_path_blocking(path
);
5619 btrfs_tree_read_lock(next
);
5620 btrfs_clear_path_blocking(path
, next
,
5623 next_rw_lock
= BTRFS_READ_LOCK
;
5628 unlock_up(path
, 0, 1, 0, NULL
);
5629 path
->leave_spinning
= old_spinning
;
5631 btrfs_set_path_blocking(path
);
5637 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
5638 * searching until it gets past min_objectid or finds an item of 'type'
5640 * returns 0 if something is found, 1 if nothing was found and < 0 on error
5642 int btrfs_previous_item(struct btrfs_root
*root
,
5643 struct btrfs_path
*path
, u64 min_objectid
,
5646 struct btrfs_key found_key
;
5647 struct extent_buffer
*leaf
;
5652 if (path
->slots
[0] == 0) {
5653 btrfs_set_path_blocking(path
);
5654 ret
= btrfs_prev_leaf(root
, path
);
5660 leaf
= path
->nodes
[0];
5661 nritems
= btrfs_header_nritems(leaf
);
5664 if (path
->slots
[0] == nritems
)
5667 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
5668 if (found_key
.objectid
< min_objectid
)
5670 if (found_key
.type
== type
)
5672 if (found_key
.objectid
== min_objectid
&&
5673 found_key
.type
< type
)