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
);
1092 tree_mod_log_free_eb(root
->fs_info
, buf
);
1093 btrfs_free_tree_block(trans
, root
, buf
, parent_start
,
1097 btrfs_tree_unlock(buf
);
1098 free_extent_buffer_stale(buf
);
1099 btrfs_mark_buffer_dirty(cow
);
1105 * returns the logical address of the oldest predecessor of the given root.
1106 * entries older than time_seq are ignored.
1108 static struct tree_mod_elem
*
1109 __tree_mod_log_oldest_root(struct btrfs_fs_info
*fs_info
,
1110 struct extent_buffer
*eb_root
, u64 time_seq
)
1112 struct tree_mod_elem
*tm
;
1113 struct tree_mod_elem
*found
= NULL
;
1114 u64 root_logical
= eb_root
->start
;
1121 * the very last operation that's logged for a root is the replacement
1122 * operation (if it is replaced at all). this has the index of the *new*
1123 * root, making it the very first operation that's logged for this root.
1126 tm
= tree_mod_log_search_oldest(fs_info
, root_logical
,
1131 * if there are no tree operation for the oldest root, we simply
1132 * return it. this should only happen if that (old) root is at
1139 * if there's an operation that's not a root replacement, we
1140 * found the oldest version of our root. normally, we'll find a
1141 * MOD_LOG_KEY_REMOVE_WHILE_FREEING operation here.
1143 if (tm
->op
!= MOD_LOG_ROOT_REPLACE
)
1147 root_logical
= tm
->old_root
.logical
;
1151 /* if there's no old root to return, return what we found instead */
1159 * tm is a pointer to the first operation to rewind within eb. then, all
1160 * previous operations will be rewinded (until we reach something older than
1164 __tree_mod_log_rewind(struct extent_buffer
*eb
, u64 time_seq
,
1165 struct tree_mod_elem
*first_tm
)
1168 struct rb_node
*next
;
1169 struct tree_mod_elem
*tm
= first_tm
;
1170 unsigned long o_dst
;
1171 unsigned long o_src
;
1172 unsigned long p_size
= sizeof(struct btrfs_key_ptr
);
1174 n
= btrfs_header_nritems(eb
);
1175 while (tm
&& tm
->seq
>= time_seq
) {
1177 * all the operations are recorded with the operator used for
1178 * the modification. as we're going backwards, we do the
1179 * opposite of each operation here.
1182 case MOD_LOG_KEY_REMOVE_WHILE_FREEING
:
1183 BUG_ON(tm
->slot
< n
);
1185 case MOD_LOG_KEY_REMOVE_WHILE_MOVING
:
1186 case MOD_LOG_KEY_REMOVE
:
1187 btrfs_set_node_key(eb
, &tm
->key
, tm
->slot
);
1188 btrfs_set_node_blockptr(eb
, tm
->slot
, tm
->blockptr
);
1189 btrfs_set_node_ptr_generation(eb
, tm
->slot
,
1193 case MOD_LOG_KEY_REPLACE
:
1194 BUG_ON(tm
->slot
>= n
);
1195 btrfs_set_node_key(eb
, &tm
->key
, tm
->slot
);
1196 btrfs_set_node_blockptr(eb
, tm
->slot
, tm
->blockptr
);
1197 btrfs_set_node_ptr_generation(eb
, tm
->slot
,
1200 case MOD_LOG_KEY_ADD
:
1201 /* if a move operation is needed it's in the log */
1204 case MOD_LOG_MOVE_KEYS
:
1205 o_dst
= btrfs_node_key_ptr_offset(tm
->slot
);
1206 o_src
= btrfs_node_key_ptr_offset(tm
->move
.dst_slot
);
1207 memmove_extent_buffer(eb
, o_dst
, o_src
,
1208 tm
->move
.nr_items
* p_size
);
1210 case MOD_LOG_ROOT_REPLACE
:
1212 * this operation is special. for roots, this must be
1213 * handled explicitly before rewinding.
1214 * for non-roots, this operation may exist if the node
1215 * was a root: root A -> child B; then A gets empty and
1216 * B is promoted to the new root. in the mod log, we'll
1217 * have a root-replace operation for B, a tree block
1218 * that is no root. we simply ignore that operation.
1222 next
= rb_next(&tm
->node
);
1225 tm
= container_of(next
, struct tree_mod_elem
, node
);
1226 if (tm
->index
!= first_tm
->index
)
1229 btrfs_set_header_nritems(eb
, n
);
1233 * Called with eb read locked. If the buffer cannot be rewinded, the same buffer
1234 * is returned. If rewind operations happen, a fresh buffer is returned. The
1235 * returned buffer is always read-locked. If the returned buffer is not the
1236 * input buffer, the lock on the input buffer is released and the input buffer
1237 * is freed (its refcount is decremented).
1239 static struct extent_buffer
*
1240 tree_mod_log_rewind(struct btrfs_fs_info
*fs_info
, struct extent_buffer
*eb
,
1243 struct extent_buffer
*eb_rewin
;
1244 struct tree_mod_elem
*tm
;
1249 if (btrfs_header_level(eb
) == 0)
1252 tm
= tree_mod_log_search(fs_info
, eb
->start
, time_seq
);
1256 if (tm
->op
== MOD_LOG_KEY_REMOVE_WHILE_FREEING
) {
1257 BUG_ON(tm
->slot
!= 0);
1258 eb_rewin
= alloc_dummy_extent_buffer(eb
->start
,
1259 fs_info
->tree_root
->nodesize
);
1261 btrfs_set_header_bytenr(eb_rewin
, eb
->start
);
1262 btrfs_set_header_backref_rev(eb_rewin
,
1263 btrfs_header_backref_rev(eb
));
1264 btrfs_set_header_owner(eb_rewin
, btrfs_header_owner(eb
));
1265 btrfs_set_header_level(eb_rewin
, btrfs_header_level(eb
));
1267 eb_rewin
= btrfs_clone_extent_buffer(eb
);
1271 extent_buffer_get(eb_rewin
);
1272 btrfs_tree_read_unlock(eb
);
1273 free_extent_buffer(eb
);
1275 extent_buffer_get(eb_rewin
);
1276 btrfs_tree_read_lock(eb_rewin
);
1277 __tree_mod_log_rewind(eb_rewin
, time_seq
, tm
);
1278 WARN_ON(btrfs_header_nritems(eb_rewin
) >
1279 BTRFS_NODEPTRS_PER_BLOCK(fs_info
->tree_root
));
1285 * get_old_root() rewinds the state of @root's root node to the given @time_seq
1286 * value. If there are no changes, the current root->root_node is returned. If
1287 * anything changed in between, there's a fresh buffer allocated on which the
1288 * rewind operations are done. In any case, the returned buffer is read locked.
1289 * Returns NULL on error (with no locks held).
1291 static inline struct extent_buffer
*
1292 get_old_root(struct btrfs_root
*root
, u64 time_seq
)
1294 struct tree_mod_elem
*tm
;
1295 struct extent_buffer
*eb
= NULL
;
1296 struct extent_buffer
*eb_root
;
1297 struct extent_buffer
*old
;
1298 struct tree_mod_root
*old_root
= NULL
;
1299 u64 old_generation
= 0;
1303 eb_root
= btrfs_read_lock_root_node(root
);
1304 tm
= __tree_mod_log_oldest_root(root
->fs_info
, eb_root
, time_seq
);
1308 if (tm
->op
== MOD_LOG_ROOT_REPLACE
) {
1309 old_root
= &tm
->old_root
;
1310 old_generation
= tm
->generation
;
1311 logical
= old_root
->logical
;
1313 logical
= eb_root
->start
;
1316 tm
= tree_mod_log_search(root
->fs_info
, logical
, time_seq
);
1317 if (old_root
&& tm
&& tm
->op
!= MOD_LOG_KEY_REMOVE_WHILE_FREEING
) {
1318 btrfs_tree_read_unlock(eb_root
);
1319 free_extent_buffer(eb_root
);
1320 blocksize
= btrfs_level_size(root
, old_root
->level
);
1321 old
= read_tree_block(root
, logical
, blocksize
, 0);
1322 if (!old
|| !extent_buffer_uptodate(old
)) {
1323 free_extent_buffer(old
);
1324 pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
1328 eb
= btrfs_clone_extent_buffer(old
);
1329 free_extent_buffer(old
);
1331 } else if (old_root
) {
1332 btrfs_tree_read_unlock(eb_root
);
1333 free_extent_buffer(eb_root
);
1334 eb
= alloc_dummy_extent_buffer(logical
, root
->nodesize
);
1336 eb
= btrfs_clone_extent_buffer(eb_root
);
1337 btrfs_tree_read_unlock(eb_root
);
1338 free_extent_buffer(eb_root
);
1343 extent_buffer_get(eb
);
1344 btrfs_tree_read_lock(eb
);
1346 btrfs_set_header_bytenr(eb
, eb
->start
);
1347 btrfs_set_header_backref_rev(eb
, BTRFS_MIXED_BACKREF_REV
);
1348 btrfs_set_header_owner(eb
, btrfs_header_owner(eb_root
));
1349 btrfs_set_header_level(eb
, old_root
->level
);
1350 btrfs_set_header_generation(eb
, old_generation
);
1353 __tree_mod_log_rewind(eb
, time_seq
, tm
);
1355 WARN_ON(btrfs_header_level(eb
) != 0);
1356 WARN_ON(btrfs_header_nritems(eb
) > BTRFS_NODEPTRS_PER_BLOCK(root
));
1361 int btrfs_old_root_level(struct btrfs_root
*root
, u64 time_seq
)
1363 struct tree_mod_elem
*tm
;
1365 struct extent_buffer
*eb_root
= btrfs_root_node(root
);
1367 tm
= __tree_mod_log_oldest_root(root
->fs_info
, eb_root
, time_seq
);
1368 if (tm
&& tm
->op
== MOD_LOG_ROOT_REPLACE
) {
1369 level
= tm
->old_root
.level
;
1371 level
= btrfs_header_level(eb_root
);
1373 free_extent_buffer(eb_root
);
1378 static inline int should_cow_block(struct btrfs_trans_handle
*trans
,
1379 struct btrfs_root
*root
,
1380 struct extent_buffer
*buf
)
1382 /* ensure we can see the force_cow */
1386 * We do not need to cow a block if
1387 * 1) this block is not created or changed in this transaction;
1388 * 2) this block does not belong to TREE_RELOC tree;
1389 * 3) the root is not forced COW.
1391 * What is forced COW:
1392 * when we create snapshot during commiting the transaction,
1393 * after we've finished coping src root, we must COW the shared
1394 * block to ensure the metadata consistency.
1396 if (btrfs_header_generation(buf
) == trans
->transid
&&
1397 !btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_WRITTEN
) &&
1398 !(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
&&
1399 btrfs_header_flag(buf
, BTRFS_HEADER_FLAG_RELOC
)) &&
1406 * cows a single block, see __btrfs_cow_block for the real work.
1407 * This version of it has extra checks so that a block isn't cow'd more than
1408 * once per transaction, as long as it hasn't been written yet
1410 noinline
int btrfs_cow_block(struct btrfs_trans_handle
*trans
,
1411 struct btrfs_root
*root
, struct extent_buffer
*buf
,
1412 struct extent_buffer
*parent
, int parent_slot
,
1413 struct extent_buffer
**cow_ret
)
1418 if (trans
->transaction
!= root
->fs_info
->running_transaction
)
1419 WARN(1, KERN_CRIT
"trans %llu running %llu\n",
1420 (unsigned long long)trans
->transid
,
1421 (unsigned long long)
1422 root
->fs_info
->running_transaction
->transid
);
1424 if (trans
->transid
!= root
->fs_info
->generation
)
1425 WARN(1, KERN_CRIT
"trans %llu running %llu\n",
1426 (unsigned long long)trans
->transid
,
1427 (unsigned long long)root
->fs_info
->generation
);
1429 if (!should_cow_block(trans
, root
, buf
)) {
1434 search_start
= buf
->start
& ~((u64
)(1024 * 1024 * 1024) - 1);
1437 btrfs_set_lock_blocking(parent
);
1438 btrfs_set_lock_blocking(buf
);
1440 ret
= __btrfs_cow_block(trans
, root
, buf
, parent
,
1441 parent_slot
, cow_ret
, search_start
, 0);
1443 trace_btrfs_cow_block(root
, buf
, *cow_ret
);
1449 * helper function for defrag to decide if two blocks pointed to by a
1450 * node are actually close by
1452 static int close_blocks(u64 blocknr
, u64 other
, u32 blocksize
)
1454 if (blocknr
< other
&& other
- (blocknr
+ blocksize
) < 32768)
1456 if (blocknr
> other
&& blocknr
- (other
+ blocksize
) < 32768)
1462 * compare two keys in a memcmp fashion
1464 static int comp_keys(struct btrfs_disk_key
*disk
, struct btrfs_key
*k2
)
1466 struct btrfs_key k1
;
1468 btrfs_disk_key_to_cpu(&k1
, disk
);
1470 return btrfs_comp_cpu_keys(&k1
, k2
);
1474 * same as comp_keys only with two btrfs_key's
1476 int btrfs_comp_cpu_keys(struct btrfs_key
*k1
, struct btrfs_key
*k2
)
1478 if (k1
->objectid
> k2
->objectid
)
1480 if (k1
->objectid
< k2
->objectid
)
1482 if (k1
->type
> k2
->type
)
1484 if (k1
->type
< k2
->type
)
1486 if (k1
->offset
> k2
->offset
)
1488 if (k1
->offset
< k2
->offset
)
1494 * this is used by the defrag code to go through all the
1495 * leaves pointed to by a node and reallocate them so that
1496 * disk order is close to key order
1498 int btrfs_realloc_node(struct btrfs_trans_handle
*trans
,
1499 struct btrfs_root
*root
, struct extent_buffer
*parent
,
1500 int start_slot
, u64
*last_ret
,
1501 struct btrfs_key
*progress
)
1503 struct extent_buffer
*cur
;
1506 u64 search_start
= *last_ret
;
1516 int progress_passed
= 0;
1517 struct btrfs_disk_key disk_key
;
1519 parent_level
= btrfs_header_level(parent
);
1521 WARN_ON(trans
->transaction
!= root
->fs_info
->running_transaction
);
1522 WARN_ON(trans
->transid
!= root
->fs_info
->generation
);
1524 parent_nritems
= btrfs_header_nritems(parent
);
1525 blocksize
= btrfs_level_size(root
, parent_level
- 1);
1526 end_slot
= parent_nritems
;
1528 if (parent_nritems
== 1)
1531 btrfs_set_lock_blocking(parent
);
1533 for (i
= start_slot
; i
< end_slot
; i
++) {
1536 btrfs_node_key(parent
, &disk_key
, i
);
1537 if (!progress_passed
&& comp_keys(&disk_key
, progress
) < 0)
1540 progress_passed
= 1;
1541 blocknr
= btrfs_node_blockptr(parent
, i
);
1542 gen
= btrfs_node_ptr_generation(parent
, i
);
1543 if (last_block
== 0)
1544 last_block
= blocknr
;
1547 other
= btrfs_node_blockptr(parent
, i
- 1);
1548 close
= close_blocks(blocknr
, other
, blocksize
);
1550 if (!close
&& i
< end_slot
- 2) {
1551 other
= btrfs_node_blockptr(parent
, i
+ 1);
1552 close
= close_blocks(blocknr
, other
, blocksize
);
1555 last_block
= blocknr
;
1559 cur
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
1561 uptodate
= btrfs_buffer_uptodate(cur
, gen
, 0);
1564 if (!cur
|| !uptodate
) {
1566 cur
= read_tree_block(root
, blocknr
,
1568 if (!cur
|| !extent_buffer_uptodate(cur
)) {
1569 free_extent_buffer(cur
);
1572 } else if (!uptodate
) {
1573 err
= btrfs_read_buffer(cur
, gen
);
1575 free_extent_buffer(cur
);
1580 if (search_start
== 0)
1581 search_start
= last_block
;
1583 btrfs_tree_lock(cur
);
1584 btrfs_set_lock_blocking(cur
);
1585 err
= __btrfs_cow_block(trans
, root
, cur
, parent
, i
,
1588 (end_slot
- i
) * blocksize
));
1590 btrfs_tree_unlock(cur
);
1591 free_extent_buffer(cur
);
1594 search_start
= cur
->start
;
1595 last_block
= cur
->start
;
1596 *last_ret
= search_start
;
1597 btrfs_tree_unlock(cur
);
1598 free_extent_buffer(cur
);
1604 * The leaf data grows from end-to-front in the node.
1605 * this returns the address of the start of the last item,
1606 * which is the stop of the leaf data stack
1608 static inline unsigned int leaf_data_end(struct btrfs_root
*root
,
1609 struct extent_buffer
*leaf
)
1611 u32 nr
= btrfs_header_nritems(leaf
);
1613 return BTRFS_LEAF_DATA_SIZE(root
);
1614 return btrfs_item_offset_nr(leaf
, nr
- 1);
1619 * search for key in the extent_buffer. The items start at offset p,
1620 * and they are item_size apart. There are 'max' items in p.
1622 * the slot in the array is returned via slot, and it points to
1623 * the place where you would insert key if it is not found in
1626 * slot may point to max if the key is bigger than all of the keys
1628 static noinline
int generic_bin_search(struct extent_buffer
*eb
,
1630 int item_size
, struct btrfs_key
*key
,
1637 struct btrfs_disk_key
*tmp
= NULL
;
1638 struct btrfs_disk_key unaligned
;
1639 unsigned long offset
;
1641 unsigned long map_start
= 0;
1642 unsigned long map_len
= 0;
1645 while (low
< high
) {
1646 mid
= (low
+ high
) / 2;
1647 offset
= p
+ mid
* item_size
;
1649 if (!kaddr
|| offset
< map_start
||
1650 (offset
+ sizeof(struct btrfs_disk_key
)) >
1651 map_start
+ map_len
) {
1653 err
= map_private_extent_buffer(eb
, offset
,
1654 sizeof(struct btrfs_disk_key
),
1655 &kaddr
, &map_start
, &map_len
);
1658 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
1661 read_extent_buffer(eb
, &unaligned
,
1662 offset
, sizeof(unaligned
));
1667 tmp
= (struct btrfs_disk_key
*)(kaddr
+ offset
-
1670 ret
= comp_keys(tmp
, key
);
1686 * simple bin_search frontend that does the right thing for
1689 static int bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
1690 int level
, int *slot
)
1693 return generic_bin_search(eb
,
1694 offsetof(struct btrfs_leaf
, items
),
1695 sizeof(struct btrfs_item
),
1696 key
, btrfs_header_nritems(eb
),
1699 return generic_bin_search(eb
,
1700 offsetof(struct btrfs_node
, ptrs
),
1701 sizeof(struct btrfs_key_ptr
),
1702 key
, btrfs_header_nritems(eb
),
1706 int btrfs_bin_search(struct extent_buffer
*eb
, struct btrfs_key
*key
,
1707 int level
, int *slot
)
1709 return bin_search(eb
, key
, level
, slot
);
1712 static void root_add_used(struct btrfs_root
*root
, u32 size
)
1714 spin_lock(&root
->accounting_lock
);
1715 btrfs_set_root_used(&root
->root_item
,
1716 btrfs_root_used(&root
->root_item
) + size
);
1717 spin_unlock(&root
->accounting_lock
);
1720 static void root_sub_used(struct btrfs_root
*root
, u32 size
)
1722 spin_lock(&root
->accounting_lock
);
1723 btrfs_set_root_used(&root
->root_item
,
1724 btrfs_root_used(&root
->root_item
) - size
);
1725 spin_unlock(&root
->accounting_lock
);
1728 /* given a node and slot number, this reads the blocks it points to. The
1729 * extent buffer is returned with a reference taken (but unlocked).
1730 * NULL is returned on error.
1732 static noinline
struct extent_buffer
*read_node_slot(struct btrfs_root
*root
,
1733 struct extent_buffer
*parent
, int slot
)
1735 int level
= btrfs_header_level(parent
);
1736 struct extent_buffer
*eb
;
1740 if (slot
>= btrfs_header_nritems(parent
))
1745 eb
= read_tree_block(root
, btrfs_node_blockptr(parent
, slot
),
1746 btrfs_level_size(root
, level
- 1),
1747 btrfs_node_ptr_generation(parent
, slot
));
1748 if (eb
&& !extent_buffer_uptodate(eb
)) {
1749 free_extent_buffer(eb
);
1757 * node level balancing, used to make sure nodes are in proper order for
1758 * item deletion. We balance from the top down, so we have to make sure
1759 * that a deletion won't leave an node completely empty later on.
1761 static noinline
int balance_level(struct btrfs_trans_handle
*trans
,
1762 struct btrfs_root
*root
,
1763 struct btrfs_path
*path
, int level
)
1765 struct extent_buffer
*right
= NULL
;
1766 struct extent_buffer
*mid
;
1767 struct extent_buffer
*left
= NULL
;
1768 struct extent_buffer
*parent
= NULL
;
1772 int orig_slot
= path
->slots
[level
];
1778 mid
= path
->nodes
[level
];
1780 WARN_ON(path
->locks
[level
] != BTRFS_WRITE_LOCK
&&
1781 path
->locks
[level
] != BTRFS_WRITE_LOCK_BLOCKING
);
1782 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1784 orig_ptr
= btrfs_node_blockptr(mid
, orig_slot
);
1786 if (level
< BTRFS_MAX_LEVEL
- 1) {
1787 parent
= path
->nodes
[level
+ 1];
1788 pslot
= path
->slots
[level
+ 1];
1792 * deal with the case where there is only one pointer in the root
1793 * by promoting the node below to a root
1796 struct extent_buffer
*child
;
1798 if (btrfs_header_nritems(mid
) != 1)
1801 /* promote the child to a root */
1802 child
= read_node_slot(root
, mid
, 0);
1805 btrfs_std_error(root
->fs_info
, ret
);
1809 btrfs_tree_lock(child
);
1810 btrfs_set_lock_blocking(child
);
1811 ret
= btrfs_cow_block(trans
, root
, child
, mid
, 0, &child
);
1813 btrfs_tree_unlock(child
);
1814 free_extent_buffer(child
);
1818 tree_mod_log_set_root_pointer(root
, child
, 1);
1819 rcu_assign_pointer(root
->node
, child
);
1821 add_root_to_dirty_list(root
);
1822 btrfs_tree_unlock(child
);
1824 path
->locks
[level
] = 0;
1825 path
->nodes
[level
] = NULL
;
1826 clean_tree_block(trans
, root
, mid
);
1827 btrfs_tree_unlock(mid
);
1828 /* once for the path */
1829 free_extent_buffer(mid
);
1831 root_sub_used(root
, mid
->len
);
1832 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
1833 /* once for the root ptr */
1834 free_extent_buffer_stale(mid
);
1837 if (btrfs_header_nritems(mid
) >
1838 BTRFS_NODEPTRS_PER_BLOCK(root
) / 4)
1841 left
= read_node_slot(root
, parent
, pslot
- 1);
1843 btrfs_tree_lock(left
);
1844 btrfs_set_lock_blocking(left
);
1845 wret
= btrfs_cow_block(trans
, root
, left
,
1846 parent
, pslot
- 1, &left
);
1852 right
= read_node_slot(root
, parent
, pslot
+ 1);
1854 btrfs_tree_lock(right
);
1855 btrfs_set_lock_blocking(right
);
1856 wret
= btrfs_cow_block(trans
, root
, right
,
1857 parent
, pslot
+ 1, &right
);
1864 /* first, try to make some room in the middle buffer */
1866 orig_slot
+= btrfs_header_nritems(left
);
1867 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1873 * then try to empty the right most buffer into the middle
1876 wret
= push_node_left(trans
, root
, mid
, right
, 1);
1877 if (wret
< 0 && wret
!= -ENOSPC
)
1879 if (btrfs_header_nritems(right
) == 0) {
1880 clean_tree_block(trans
, root
, right
);
1881 btrfs_tree_unlock(right
);
1882 del_ptr(root
, path
, level
+ 1, pslot
+ 1);
1883 root_sub_used(root
, right
->len
);
1884 btrfs_free_tree_block(trans
, root
, right
, 0, 1);
1885 free_extent_buffer_stale(right
);
1888 struct btrfs_disk_key right_key
;
1889 btrfs_node_key(right
, &right_key
, 0);
1890 tree_mod_log_set_node_key(root
->fs_info
, parent
,
1892 btrfs_set_node_key(parent
, &right_key
, pslot
+ 1);
1893 btrfs_mark_buffer_dirty(parent
);
1896 if (btrfs_header_nritems(mid
) == 1) {
1898 * we're not allowed to leave a node with one item in the
1899 * tree during a delete. A deletion from lower in the tree
1900 * could try to delete the only pointer in this node.
1901 * So, pull some keys from the left.
1902 * There has to be a left pointer at this point because
1903 * otherwise we would have pulled some pointers from the
1908 btrfs_std_error(root
->fs_info
, ret
);
1911 wret
= balance_node_right(trans
, root
, mid
, left
);
1917 wret
= push_node_left(trans
, root
, left
, mid
, 1);
1923 if (btrfs_header_nritems(mid
) == 0) {
1924 clean_tree_block(trans
, root
, mid
);
1925 btrfs_tree_unlock(mid
);
1926 del_ptr(root
, path
, level
+ 1, pslot
);
1927 root_sub_used(root
, mid
->len
);
1928 btrfs_free_tree_block(trans
, root
, mid
, 0, 1);
1929 free_extent_buffer_stale(mid
);
1932 /* update the parent key to reflect our changes */
1933 struct btrfs_disk_key mid_key
;
1934 btrfs_node_key(mid
, &mid_key
, 0);
1935 tree_mod_log_set_node_key(root
->fs_info
, parent
,
1937 btrfs_set_node_key(parent
, &mid_key
, pslot
);
1938 btrfs_mark_buffer_dirty(parent
);
1941 /* update the path */
1943 if (btrfs_header_nritems(left
) > orig_slot
) {
1944 extent_buffer_get(left
);
1945 /* left was locked after cow */
1946 path
->nodes
[level
] = left
;
1947 path
->slots
[level
+ 1] -= 1;
1948 path
->slots
[level
] = orig_slot
;
1950 btrfs_tree_unlock(mid
);
1951 free_extent_buffer(mid
);
1954 orig_slot
-= btrfs_header_nritems(left
);
1955 path
->slots
[level
] = orig_slot
;
1958 /* double check we haven't messed things up */
1960 btrfs_node_blockptr(path
->nodes
[level
], path
->slots
[level
]))
1964 btrfs_tree_unlock(right
);
1965 free_extent_buffer(right
);
1968 if (path
->nodes
[level
] != left
)
1969 btrfs_tree_unlock(left
);
1970 free_extent_buffer(left
);
1975 /* Node balancing for insertion. Here we only split or push nodes around
1976 * when they are completely full. This is also done top down, so we
1977 * have to be pessimistic.
1979 static noinline
int push_nodes_for_insert(struct btrfs_trans_handle
*trans
,
1980 struct btrfs_root
*root
,
1981 struct btrfs_path
*path
, int level
)
1983 struct extent_buffer
*right
= NULL
;
1984 struct extent_buffer
*mid
;
1985 struct extent_buffer
*left
= NULL
;
1986 struct extent_buffer
*parent
= NULL
;
1990 int orig_slot
= path
->slots
[level
];
1995 mid
= path
->nodes
[level
];
1996 WARN_ON(btrfs_header_generation(mid
) != trans
->transid
);
1998 if (level
< BTRFS_MAX_LEVEL
- 1) {
1999 parent
= path
->nodes
[level
+ 1];
2000 pslot
= path
->slots
[level
+ 1];
2006 left
= read_node_slot(root
, parent
, pslot
- 1);
2008 /* first, try to make some room in the middle buffer */
2012 btrfs_tree_lock(left
);
2013 btrfs_set_lock_blocking(left
);
2015 left_nr
= btrfs_header_nritems(left
);
2016 if (left_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
2019 ret
= btrfs_cow_block(trans
, root
, left
, parent
,
2024 wret
= push_node_left(trans
, root
,
2031 struct btrfs_disk_key disk_key
;
2032 orig_slot
+= left_nr
;
2033 btrfs_node_key(mid
, &disk_key
, 0);
2034 tree_mod_log_set_node_key(root
->fs_info
, parent
,
2036 btrfs_set_node_key(parent
, &disk_key
, pslot
);
2037 btrfs_mark_buffer_dirty(parent
);
2038 if (btrfs_header_nritems(left
) > orig_slot
) {
2039 path
->nodes
[level
] = left
;
2040 path
->slots
[level
+ 1] -= 1;
2041 path
->slots
[level
] = orig_slot
;
2042 btrfs_tree_unlock(mid
);
2043 free_extent_buffer(mid
);
2046 btrfs_header_nritems(left
);
2047 path
->slots
[level
] = orig_slot
;
2048 btrfs_tree_unlock(left
);
2049 free_extent_buffer(left
);
2053 btrfs_tree_unlock(left
);
2054 free_extent_buffer(left
);
2056 right
= read_node_slot(root
, parent
, pslot
+ 1);
2059 * then try to empty the right most buffer into the middle
2064 btrfs_tree_lock(right
);
2065 btrfs_set_lock_blocking(right
);
2067 right_nr
= btrfs_header_nritems(right
);
2068 if (right_nr
>= BTRFS_NODEPTRS_PER_BLOCK(root
) - 1) {
2071 ret
= btrfs_cow_block(trans
, root
, right
,
2077 wret
= balance_node_right(trans
, root
,
2084 struct btrfs_disk_key disk_key
;
2086 btrfs_node_key(right
, &disk_key
, 0);
2087 tree_mod_log_set_node_key(root
->fs_info
, parent
,
2089 btrfs_set_node_key(parent
, &disk_key
, pslot
+ 1);
2090 btrfs_mark_buffer_dirty(parent
);
2092 if (btrfs_header_nritems(mid
) <= orig_slot
) {
2093 path
->nodes
[level
] = right
;
2094 path
->slots
[level
+ 1] += 1;
2095 path
->slots
[level
] = orig_slot
-
2096 btrfs_header_nritems(mid
);
2097 btrfs_tree_unlock(mid
);
2098 free_extent_buffer(mid
);
2100 btrfs_tree_unlock(right
);
2101 free_extent_buffer(right
);
2105 btrfs_tree_unlock(right
);
2106 free_extent_buffer(right
);
2112 * readahead one full node of leaves, finding things that are close
2113 * to the block in 'slot', and triggering ra on them.
2115 static void reada_for_search(struct btrfs_root
*root
,
2116 struct btrfs_path
*path
,
2117 int level
, int slot
, u64 objectid
)
2119 struct extent_buffer
*node
;
2120 struct btrfs_disk_key disk_key
;
2126 int direction
= path
->reada
;
2127 struct extent_buffer
*eb
;
2135 if (!path
->nodes
[level
])
2138 node
= path
->nodes
[level
];
2140 search
= btrfs_node_blockptr(node
, slot
);
2141 blocksize
= btrfs_level_size(root
, level
- 1);
2142 eb
= btrfs_find_tree_block(root
, search
, blocksize
);
2144 free_extent_buffer(eb
);
2150 nritems
= btrfs_header_nritems(node
);
2154 if (direction
< 0) {
2158 } else if (direction
> 0) {
2163 if (path
->reada
< 0 && objectid
) {
2164 btrfs_node_key(node
, &disk_key
, nr
);
2165 if (btrfs_disk_key_objectid(&disk_key
) != objectid
)
2168 search
= btrfs_node_blockptr(node
, nr
);
2169 if ((search
<= target
&& target
- search
<= 65536) ||
2170 (search
> target
&& search
- target
<= 65536)) {
2171 gen
= btrfs_node_ptr_generation(node
, nr
);
2172 readahead_tree_block(root
, search
, blocksize
, gen
);
2176 if ((nread
> 65536 || nscan
> 32))
2182 * returns -EAGAIN if it had to drop the path, or zero if everything was in
2185 static noinline
int reada_for_balance(struct btrfs_root
*root
,
2186 struct btrfs_path
*path
, int level
)
2190 struct extent_buffer
*parent
;
2191 struct extent_buffer
*eb
;
2198 parent
= path
->nodes
[level
+ 1];
2202 nritems
= btrfs_header_nritems(parent
);
2203 slot
= path
->slots
[level
+ 1];
2204 blocksize
= btrfs_level_size(root
, level
);
2207 block1
= btrfs_node_blockptr(parent
, slot
- 1);
2208 gen
= btrfs_node_ptr_generation(parent
, slot
- 1);
2209 eb
= btrfs_find_tree_block(root
, block1
, blocksize
);
2211 * if we get -eagain from btrfs_buffer_uptodate, we
2212 * don't want to return eagain here. That will loop
2215 if (eb
&& btrfs_buffer_uptodate(eb
, gen
, 1) != 0)
2217 free_extent_buffer(eb
);
2219 if (slot
+ 1 < nritems
) {
2220 block2
= btrfs_node_blockptr(parent
, slot
+ 1);
2221 gen
= btrfs_node_ptr_generation(parent
, slot
+ 1);
2222 eb
= btrfs_find_tree_block(root
, block2
, blocksize
);
2223 if (eb
&& btrfs_buffer_uptodate(eb
, gen
, 1) != 0)
2225 free_extent_buffer(eb
);
2227 if (block1
|| block2
) {
2230 /* release the whole path */
2231 btrfs_release_path(path
);
2233 /* read the blocks */
2235 readahead_tree_block(root
, block1
, blocksize
, 0);
2237 readahead_tree_block(root
, block2
, blocksize
, 0);
2240 eb
= read_tree_block(root
, block1
, blocksize
, 0);
2241 free_extent_buffer(eb
);
2244 eb
= read_tree_block(root
, block2
, blocksize
, 0);
2245 free_extent_buffer(eb
);
2253 * when we walk down the tree, it is usually safe to unlock the higher layers
2254 * in the tree. The exceptions are when our path goes through slot 0, because
2255 * operations on the tree might require changing key pointers higher up in the
2258 * callers might also have set path->keep_locks, which tells this code to keep
2259 * the lock if the path points to the last slot in the block. This is part of
2260 * walking through the tree, and selecting the next slot in the higher block.
2262 * lowest_unlock sets the lowest level in the tree we're allowed to unlock. so
2263 * if lowest_unlock is 1, level 0 won't be unlocked
2265 static noinline
void unlock_up(struct btrfs_path
*path
, int level
,
2266 int lowest_unlock
, int min_write_lock_level
,
2267 int *write_lock_level
)
2270 int skip_level
= level
;
2272 struct extent_buffer
*t
;
2274 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2275 if (!path
->nodes
[i
])
2277 if (!path
->locks
[i
])
2279 if (!no_skips
&& path
->slots
[i
] == 0) {
2283 if (!no_skips
&& path
->keep_locks
) {
2286 nritems
= btrfs_header_nritems(t
);
2287 if (nritems
< 1 || path
->slots
[i
] >= nritems
- 1) {
2292 if (skip_level
< i
&& i
>= lowest_unlock
)
2296 if (i
>= lowest_unlock
&& i
> skip_level
&& path
->locks
[i
]) {
2297 btrfs_tree_unlock_rw(t
, path
->locks
[i
]);
2299 if (write_lock_level
&&
2300 i
> min_write_lock_level
&&
2301 i
<= *write_lock_level
) {
2302 *write_lock_level
= i
- 1;
2309 * This releases any locks held in the path starting at level and
2310 * going all the way up to the root.
2312 * btrfs_search_slot will keep the lock held on higher nodes in a few
2313 * corner cases, such as COW of the block at slot zero in the node. This
2314 * ignores those rules, and it should only be called when there are no
2315 * more updates to be done higher up in the tree.
2317 noinline
void btrfs_unlock_up_safe(struct btrfs_path
*path
, int level
)
2321 if (path
->keep_locks
)
2324 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2325 if (!path
->nodes
[i
])
2327 if (!path
->locks
[i
])
2329 btrfs_tree_unlock_rw(path
->nodes
[i
], path
->locks
[i
]);
2335 * helper function for btrfs_search_slot. The goal is to find a block
2336 * in cache without setting the path to blocking. If we find the block
2337 * we return zero and the path is unchanged.
2339 * If we can't find the block, we set the path blocking and do some
2340 * reada. -EAGAIN is returned and the search must be repeated.
2343 read_block_for_search(struct btrfs_trans_handle
*trans
,
2344 struct btrfs_root
*root
, struct btrfs_path
*p
,
2345 struct extent_buffer
**eb_ret
, int level
, int slot
,
2346 struct btrfs_key
*key
, u64 time_seq
)
2351 struct extent_buffer
*b
= *eb_ret
;
2352 struct extent_buffer
*tmp
;
2355 blocknr
= btrfs_node_blockptr(b
, slot
);
2356 gen
= btrfs_node_ptr_generation(b
, slot
);
2357 blocksize
= btrfs_level_size(root
, level
- 1);
2359 tmp
= btrfs_find_tree_block(root
, blocknr
, blocksize
);
2361 /* first we do an atomic uptodate check */
2362 if (btrfs_buffer_uptodate(tmp
, gen
, 1) > 0) {
2367 /* the pages were up to date, but we failed
2368 * the generation number check. Do a full
2369 * read for the generation number that is correct.
2370 * We must do this without dropping locks so
2371 * we can trust our generation number
2373 btrfs_set_path_blocking(p
);
2375 /* now we're allowed to do a blocking uptodate check */
2376 ret
= btrfs_read_buffer(tmp
, gen
);
2381 free_extent_buffer(tmp
);
2382 btrfs_release_path(p
);
2387 * reduce lock contention at high levels
2388 * of the btree by dropping locks before
2389 * we read. Don't release the lock on the current
2390 * level because we need to walk this node to figure
2391 * out which blocks to read.
2393 btrfs_unlock_up_safe(p
, level
+ 1);
2394 btrfs_set_path_blocking(p
);
2396 free_extent_buffer(tmp
);
2398 reada_for_search(root
, p
, level
, slot
, key
->objectid
);
2400 btrfs_release_path(p
);
2403 tmp
= read_tree_block(root
, blocknr
, blocksize
, 0);
2406 * If the read above didn't mark this buffer up to date,
2407 * it will never end up being up to date. Set ret to EIO now
2408 * and give up so that our caller doesn't loop forever
2411 if (!btrfs_buffer_uptodate(tmp
, 0, 0))
2413 free_extent_buffer(tmp
);
2419 * helper function for btrfs_search_slot. This does all of the checks
2420 * for node-level blocks and does any balancing required based on
2423 * If no extra work was required, zero is returned. If we had to
2424 * drop the path, -EAGAIN is returned and btrfs_search_slot must
2428 setup_nodes_for_search(struct btrfs_trans_handle
*trans
,
2429 struct btrfs_root
*root
, struct btrfs_path
*p
,
2430 struct extent_buffer
*b
, int level
, int ins_len
,
2431 int *write_lock_level
)
2434 if ((p
->search_for_split
|| ins_len
> 0) && btrfs_header_nritems(b
) >=
2435 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3) {
2438 if (*write_lock_level
< level
+ 1) {
2439 *write_lock_level
= level
+ 1;
2440 btrfs_release_path(p
);
2444 sret
= reada_for_balance(root
, p
, level
);
2448 btrfs_set_path_blocking(p
);
2449 sret
= split_node(trans
, root
, p
, level
);
2450 btrfs_clear_path_blocking(p
, NULL
, 0);
2457 b
= p
->nodes
[level
];
2458 } else if (ins_len
< 0 && btrfs_header_nritems(b
) <
2459 BTRFS_NODEPTRS_PER_BLOCK(root
) / 2) {
2462 if (*write_lock_level
< level
+ 1) {
2463 *write_lock_level
= level
+ 1;
2464 btrfs_release_path(p
);
2468 sret
= reada_for_balance(root
, p
, level
);
2472 btrfs_set_path_blocking(p
);
2473 sret
= balance_level(trans
, root
, p
, level
);
2474 btrfs_clear_path_blocking(p
, NULL
, 0);
2480 b
= p
->nodes
[level
];
2482 btrfs_release_path(p
);
2485 BUG_ON(btrfs_header_nritems(b
) == 1);
2496 * look for key in the tree. path is filled in with nodes along the way
2497 * if key is found, we return zero and you can find the item in the leaf
2498 * level of the path (level 0)
2500 * If the key isn't found, the path points to the slot where it should
2501 * be inserted, and 1 is returned. If there are other errors during the
2502 * search a negative error number is returned.
2504 * if ins_len > 0, nodes and leaves will be split as we walk down the
2505 * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
2508 int btrfs_search_slot(struct btrfs_trans_handle
*trans
, struct btrfs_root
2509 *root
, struct btrfs_key
*key
, struct btrfs_path
*p
, int
2512 struct extent_buffer
*b
;
2517 int lowest_unlock
= 1;
2519 /* everything at write_lock_level or lower must be write locked */
2520 int write_lock_level
= 0;
2521 u8 lowest_level
= 0;
2522 int min_write_lock_level
;
2524 lowest_level
= p
->lowest_level
;
2525 WARN_ON(lowest_level
&& ins_len
> 0);
2526 WARN_ON(p
->nodes
[0] != NULL
);
2531 /* when we are removing items, we might have to go up to level
2532 * two as we update tree pointers Make sure we keep write
2533 * for those levels as well
2535 write_lock_level
= 2;
2536 } else if (ins_len
> 0) {
2538 * for inserting items, make sure we have a write lock on
2539 * level 1 so we can update keys
2541 write_lock_level
= 1;
2545 write_lock_level
= -1;
2547 if (cow
&& (p
->keep_locks
|| p
->lowest_level
))
2548 write_lock_level
= BTRFS_MAX_LEVEL
;
2550 min_write_lock_level
= write_lock_level
;
2554 * we try very hard to do read locks on the root
2556 root_lock
= BTRFS_READ_LOCK
;
2558 if (p
->search_commit_root
) {
2560 * the commit roots are read only
2561 * so we always do read locks
2563 b
= root
->commit_root
;
2564 extent_buffer_get(b
);
2565 level
= btrfs_header_level(b
);
2566 if (!p
->skip_locking
)
2567 btrfs_tree_read_lock(b
);
2569 if (p
->skip_locking
) {
2570 b
= btrfs_root_node(root
);
2571 level
= btrfs_header_level(b
);
2573 /* we don't know the level of the root node
2574 * until we actually have it read locked
2576 b
= btrfs_read_lock_root_node(root
);
2577 level
= btrfs_header_level(b
);
2578 if (level
<= write_lock_level
) {
2579 /* whoops, must trade for write lock */
2580 btrfs_tree_read_unlock(b
);
2581 free_extent_buffer(b
);
2582 b
= btrfs_lock_root_node(root
);
2583 root_lock
= BTRFS_WRITE_LOCK
;
2585 /* the level might have changed, check again */
2586 level
= btrfs_header_level(b
);
2590 p
->nodes
[level
] = b
;
2591 if (!p
->skip_locking
)
2592 p
->locks
[level
] = root_lock
;
2595 level
= btrfs_header_level(b
);
2598 * setup the path here so we can release it under lock
2599 * contention with the cow code
2603 * if we don't really need to cow this block
2604 * then we don't want to set the path blocking,
2605 * so we test it here
2607 if (!should_cow_block(trans
, root
, b
))
2610 btrfs_set_path_blocking(p
);
2613 * must have write locks on this node and the
2616 if (level
> write_lock_level
||
2617 (level
+ 1 > write_lock_level
&&
2618 level
+ 1 < BTRFS_MAX_LEVEL
&&
2619 p
->nodes
[level
+ 1])) {
2620 write_lock_level
= level
+ 1;
2621 btrfs_release_path(p
);
2625 err
= btrfs_cow_block(trans
, root
, b
,
2626 p
->nodes
[level
+ 1],
2627 p
->slots
[level
+ 1], &b
);
2634 BUG_ON(!cow
&& ins_len
);
2636 p
->nodes
[level
] = b
;
2637 btrfs_clear_path_blocking(p
, NULL
, 0);
2640 * we have a lock on b and as long as we aren't changing
2641 * the tree, there is no way to for the items in b to change.
2642 * It is safe to drop the lock on our parent before we
2643 * go through the expensive btree search on b.
2645 * If cow is true, then we might be changing slot zero,
2646 * which may require changing the parent. So, we can't
2647 * drop the lock until after we know which slot we're
2651 btrfs_unlock_up_safe(p
, level
+ 1);
2653 ret
= bin_search(b
, key
, level
, &slot
);
2657 if (ret
&& slot
> 0) {
2661 p
->slots
[level
] = slot
;
2662 err
= setup_nodes_for_search(trans
, root
, p
, b
, level
,
2663 ins_len
, &write_lock_level
);
2670 b
= p
->nodes
[level
];
2671 slot
= p
->slots
[level
];
2674 * slot 0 is special, if we change the key
2675 * we have to update the parent pointer
2676 * which means we must have a write lock
2679 if (slot
== 0 && cow
&&
2680 write_lock_level
< level
+ 1) {
2681 write_lock_level
= level
+ 1;
2682 btrfs_release_path(p
);
2686 unlock_up(p
, level
, lowest_unlock
,
2687 min_write_lock_level
, &write_lock_level
);
2689 if (level
== lowest_level
) {
2695 err
= read_block_for_search(trans
, root
, p
,
2696 &b
, level
, slot
, key
, 0);
2704 if (!p
->skip_locking
) {
2705 level
= btrfs_header_level(b
);
2706 if (level
<= write_lock_level
) {
2707 err
= btrfs_try_tree_write_lock(b
);
2709 btrfs_set_path_blocking(p
);
2711 btrfs_clear_path_blocking(p
, b
,
2714 p
->locks
[level
] = BTRFS_WRITE_LOCK
;
2716 err
= btrfs_try_tree_read_lock(b
);
2718 btrfs_set_path_blocking(p
);
2719 btrfs_tree_read_lock(b
);
2720 btrfs_clear_path_blocking(p
, b
,
2723 p
->locks
[level
] = BTRFS_READ_LOCK
;
2725 p
->nodes
[level
] = b
;
2728 p
->slots
[level
] = slot
;
2730 btrfs_leaf_free_space(root
, b
) < ins_len
) {
2731 if (write_lock_level
< 1) {
2732 write_lock_level
= 1;
2733 btrfs_release_path(p
);
2737 btrfs_set_path_blocking(p
);
2738 err
= split_leaf(trans
, root
, key
,
2739 p
, ins_len
, ret
== 0);
2740 btrfs_clear_path_blocking(p
, NULL
, 0);
2748 if (!p
->search_for_split
)
2749 unlock_up(p
, level
, lowest_unlock
,
2750 min_write_lock_level
, &write_lock_level
);
2757 * we don't really know what they plan on doing with the path
2758 * from here on, so for now just mark it as blocking
2760 if (!p
->leave_spinning
)
2761 btrfs_set_path_blocking(p
);
2763 btrfs_release_path(p
);
2768 * Like btrfs_search_slot, this looks for a key in the given tree. It uses the
2769 * current state of the tree together with the operations recorded in the tree
2770 * modification log to search for the key in a previous version of this tree, as
2771 * denoted by the time_seq parameter.
2773 * Naturally, there is no support for insert, delete or cow operations.
2775 * The resulting path and return value will be set up as if we called
2776 * btrfs_search_slot at that point in time with ins_len and cow both set to 0.
2778 int btrfs_search_old_slot(struct btrfs_root
*root
, struct btrfs_key
*key
,
2779 struct btrfs_path
*p
, u64 time_seq
)
2781 struct extent_buffer
*b
;
2786 int lowest_unlock
= 1;
2787 u8 lowest_level
= 0;
2789 lowest_level
= p
->lowest_level
;
2790 WARN_ON(p
->nodes
[0] != NULL
);
2792 if (p
->search_commit_root
) {
2794 return btrfs_search_slot(NULL
, root
, key
, p
, 0, 0);
2798 b
= get_old_root(root
, time_seq
);
2799 level
= btrfs_header_level(b
);
2800 p
->locks
[level
] = BTRFS_READ_LOCK
;
2803 level
= btrfs_header_level(b
);
2804 p
->nodes
[level
] = b
;
2805 btrfs_clear_path_blocking(p
, NULL
, 0);
2808 * we have a lock on b and as long as we aren't changing
2809 * the tree, there is no way to for the items in b to change.
2810 * It is safe to drop the lock on our parent before we
2811 * go through the expensive btree search on b.
2813 btrfs_unlock_up_safe(p
, level
+ 1);
2815 ret
= bin_search(b
, key
, level
, &slot
);
2819 if (ret
&& slot
> 0) {
2823 p
->slots
[level
] = slot
;
2824 unlock_up(p
, level
, lowest_unlock
, 0, NULL
);
2826 if (level
== lowest_level
) {
2832 err
= read_block_for_search(NULL
, root
, p
, &b
, level
,
2833 slot
, key
, time_seq
);
2841 level
= btrfs_header_level(b
);
2842 err
= btrfs_try_tree_read_lock(b
);
2844 btrfs_set_path_blocking(p
);
2845 btrfs_tree_read_lock(b
);
2846 btrfs_clear_path_blocking(p
, b
,
2849 b
= tree_mod_log_rewind(root
->fs_info
, b
, time_seq
);
2850 p
->locks
[level
] = BTRFS_READ_LOCK
;
2851 p
->nodes
[level
] = b
;
2853 p
->slots
[level
] = slot
;
2854 unlock_up(p
, level
, lowest_unlock
, 0, NULL
);
2860 if (!p
->leave_spinning
)
2861 btrfs_set_path_blocking(p
);
2863 btrfs_release_path(p
);
2869 * helper to use instead of search slot if no exact match is needed but
2870 * instead the next or previous item should be returned.
2871 * When find_higher is true, the next higher item is returned, the next lower
2873 * When return_any and find_higher are both true, and no higher item is found,
2874 * return the next lower instead.
2875 * When return_any is true and find_higher is false, and no lower item is found,
2876 * return the next higher instead.
2877 * It returns 0 if any item is found, 1 if none is found (tree empty), and
2880 int btrfs_search_slot_for_read(struct btrfs_root
*root
,
2881 struct btrfs_key
*key
, struct btrfs_path
*p
,
2882 int find_higher
, int return_any
)
2885 struct extent_buffer
*leaf
;
2888 ret
= btrfs_search_slot(NULL
, root
, key
, p
, 0, 0);
2892 * a return value of 1 means the path is at the position where the
2893 * item should be inserted. Normally this is the next bigger item,
2894 * but in case the previous item is the last in a leaf, path points
2895 * to the first free slot in the previous leaf, i.e. at an invalid
2901 if (p
->slots
[0] >= btrfs_header_nritems(leaf
)) {
2902 ret
= btrfs_next_leaf(root
, p
);
2908 * no higher item found, return the next
2913 btrfs_release_path(p
);
2917 if (p
->slots
[0] == 0) {
2918 ret
= btrfs_prev_leaf(root
, p
);
2922 p
->slots
[0] = btrfs_header_nritems(leaf
) - 1;
2928 * no lower item found, return the next
2933 btrfs_release_path(p
);
2943 * adjust the pointers going up the tree, starting at level
2944 * making sure the right key of each node is points to 'key'.
2945 * This is used after shifting pointers to the left, so it stops
2946 * fixing up pointers when a given leaf/node is not in slot 0 of the
2950 static void fixup_low_keys(struct btrfs_root
*root
, struct btrfs_path
*path
,
2951 struct btrfs_disk_key
*key
, int level
)
2954 struct extent_buffer
*t
;
2956 for (i
= level
; i
< BTRFS_MAX_LEVEL
; i
++) {
2957 int tslot
= path
->slots
[i
];
2958 if (!path
->nodes
[i
])
2961 tree_mod_log_set_node_key(root
->fs_info
, t
, tslot
, 1);
2962 btrfs_set_node_key(t
, key
, tslot
);
2963 btrfs_mark_buffer_dirty(path
->nodes
[i
]);
2972 * This function isn't completely safe. It's the caller's responsibility
2973 * that the new key won't break the order
2975 void btrfs_set_item_key_safe(struct btrfs_root
*root
, struct btrfs_path
*path
,
2976 struct btrfs_key
*new_key
)
2978 struct btrfs_disk_key disk_key
;
2979 struct extent_buffer
*eb
;
2982 eb
= path
->nodes
[0];
2983 slot
= path
->slots
[0];
2985 btrfs_item_key(eb
, &disk_key
, slot
- 1);
2986 BUG_ON(comp_keys(&disk_key
, new_key
) >= 0);
2988 if (slot
< btrfs_header_nritems(eb
) - 1) {
2989 btrfs_item_key(eb
, &disk_key
, slot
+ 1);
2990 BUG_ON(comp_keys(&disk_key
, new_key
) <= 0);
2993 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
2994 btrfs_set_item_key(eb
, &disk_key
, slot
);
2995 btrfs_mark_buffer_dirty(eb
);
2997 fixup_low_keys(root
, path
, &disk_key
, 1);
3001 * try to push data from one node into the next node left in the
3004 * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
3005 * error, and > 0 if there was no room in the left hand block.
3007 static int push_node_left(struct btrfs_trans_handle
*trans
,
3008 struct btrfs_root
*root
, struct extent_buffer
*dst
,
3009 struct extent_buffer
*src
, int empty
)
3016 src_nritems
= btrfs_header_nritems(src
);
3017 dst_nritems
= btrfs_header_nritems(dst
);
3018 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
3019 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
3020 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
3022 if (!empty
&& src_nritems
<= 8)
3025 if (push_items
<= 0)
3029 push_items
= min(src_nritems
, push_items
);
3030 if (push_items
< src_nritems
) {
3031 /* leave at least 8 pointers in the node if
3032 * we aren't going to empty it
3034 if (src_nritems
- push_items
< 8) {
3035 if (push_items
<= 8)
3041 push_items
= min(src_nritems
- 8, push_items
);
3043 tree_mod_log_eb_copy(root
->fs_info
, dst
, src
, dst_nritems
, 0,
3045 copy_extent_buffer(dst
, src
,
3046 btrfs_node_key_ptr_offset(dst_nritems
),
3047 btrfs_node_key_ptr_offset(0),
3048 push_items
* sizeof(struct btrfs_key_ptr
));
3050 if (push_items
< src_nritems
) {
3052 * don't call tree_mod_log_eb_move here, key removal was already
3053 * fully logged by tree_mod_log_eb_copy above.
3055 memmove_extent_buffer(src
, btrfs_node_key_ptr_offset(0),
3056 btrfs_node_key_ptr_offset(push_items
),
3057 (src_nritems
- push_items
) *
3058 sizeof(struct btrfs_key_ptr
));
3060 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
3061 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
3062 btrfs_mark_buffer_dirty(src
);
3063 btrfs_mark_buffer_dirty(dst
);
3069 * try to push data from one node into the next node right in the
3072 * returns 0 if some ptrs were pushed, < 0 if there was some horrible
3073 * error, and > 0 if there was no room in the right hand block.
3075 * this will only push up to 1/2 the contents of the left node over
3077 static int balance_node_right(struct btrfs_trans_handle
*trans
,
3078 struct btrfs_root
*root
,
3079 struct extent_buffer
*dst
,
3080 struct extent_buffer
*src
)
3088 WARN_ON(btrfs_header_generation(src
) != trans
->transid
);
3089 WARN_ON(btrfs_header_generation(dst
) != trans
->transid
);
3091 src_nritems
= btrfs_header_nritems(src
);
3092 dst_nritems
= btrfs_header_nritems(dst
);
3093 push_items
= BTRFS_NODEPTRS_PER_BLOCK(root
) - dst_nritems
;
3094 if (push_items
<= 0)
3097 if (src_nritems
< 4)
3100 max_push
= src_nritems
/ 2 + 1;
3101 /* don't try to empty the node */
3102 if (max_push
>= src_nritems
)
3105 if (max_push
< push_items
)
3106 push_items
= max_push
;
3108 tree_mod_log_eb_move(root
->fs_info
, dst
, push_items
, 0, dst_nritems
);
3109 memmove_extent_buffer(dst
, btrfs_node_key_ptr_offset(push_items
),
3110 btrfs_node_key_ptr_offset(0),
3112 sizeof(struct btrfs_key_ptr
));
3114 tree_mod_log_eb_copy(root
->fs_info
, dst
, src
, 0,
3115 src_nritems
- push_items
, push_items
);
3116 copy_extent_buffer(dst
, src
,
3117 btrfs_node_key_ptr_offset(0),
3118 btrfs_node_key_ptr_offset(src_nritems
- push_items
),
3119 push_items
* sizeof(struct btrfs_key_ptr
));
3121 btrfs_set_header_nritems(src
, src_nritems
- push_items
);
3122 btrfs_set_header_nritems(dst
, dst_nritems
+ push_items
);
3124 btrfs_mark_buffer_dirty(src
);
3125 btrfs_mark_buffer_dirty(dst
);
3131 * helper function to insert a new root level in the tree.
3132 * A new node is allocated, and a single item is inserted to
3133 * point to the existing root
3135 * returns zero on success or < 0 on failure.
3137 static noinline
int insert_new_root(struct btrfs_trans_handle
*trans
,
3138 struct btrfs_root
*root
,
3139 struct btrfs_path
*path
, int level
)
3142 struct extent_buffer
*lower
;
3143 struct extent_buffer
*c
;
3144 struct extent_buffer
*old
;
3145 struct btrfs_disk_key lower_key
;
3147 BUG_ON(path
->nodes
[level
]);
3148 BUG_ON(path
->nodes
[level
-1] != root
->node
);
3150 lower
= path
->nodes
[level
-1];
3152 btrfs_item_key(lower
, &lower_key
, 0);
3154 btrfs_node_key(lower
, &lower_key
, 0);
3156 c
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
3157 root
->root_key
.objectid
, &lower_key
,
3158 level
, root
->node
->start
, 0);
3162 root_add_used(root
, root
->nodesize
);
3164 memset_extent_buffer(c
, 0, 0, sizeof(struct btrfs_header
));
3165 btrfs_set_header_nritems(c
, 1);
3166 btrfs_set_header_level(c
, level
);
3167 btrfs_set_header_bytenr(c
, c
->start
);
3168 btrfs_set_header_generation(c
, trans
->transid
);
3169 btrfs_set_header_backref_rev(c
, BTRFS_MIXED_BACKREF_REV
);
3170 btrfs_set_header_owner(c
, root
->root_key
.objectid
);
3172 write_extent_buffer(c
, root
->fs_info
->fsid
,
3173 (unsigned long)btrfs_header_fsid(c
),
3176 write_extent_buffer(c
, root
->fs_info
->chunk_tree_uuid
,
3177 (unsigned long)btrfs_header_chunk_tree_uuid(c
),
3180 btrfs_set_node_key(c
, &lower_key
, 0);
3181 btrfs_set_node_blockptr(c
, 0, lower
->start
);
3182 lower_gen
= btrfs_header_generation(lower
);
3183 WARN_ON(lower_gen
!= trans
->transid
);
3185 btrfs_set_node_ptr_generation(c
, 0, lower_gen
);
3187 btrfs_mark_buffer_dirty(c
);
3190 tree_mod_log_set_root_pointer(root
, c
, 0);
3191 rcu_assign_pointer(root
->node
, c
);
3193 /* the super has an extra ref to root->node */
3194 free_extent_buffer(old
);
3196 add_root_to_dirty_list(root
);
3197 extent_buffer_get(c
);
3198 path
->nodes
[level
] = c
;
3199 path
->locks
[level
] = BTRFS_WRITE_LOCK
;
3200 path
->slots
[level
] = 0;
3205 * worker function to insert a single pointer in a node.
3206 * the node should have enough room for the pointer already
3208 * slot and level indicate where you want the key to go, and
3209 * blocknr is the block the key points to.
3211 static void insert_ptr(struct btrfs_trans_handle
*trans
,
3212 struct btrfs_root
*root
, struct btrfs_path
*path
,
3213 struct btrfs_disk_key
*key
, u64 bytenr
,
3214 int slot
, int level
)
3216 struct extent_buffer
*lower
;
3220 BUG_ON(!path
->nodes
[level
]);
3221 btrfs_assert_tree_locked(path
->nodes
[level
]);
3222 lower
= path
->nodes
[level
];
3223 nritems
= btrfs_header_nritems(lower
);
3224 BUG_ON(slot
> nritems
);
3225 BUG_ON(nritems
== BTRFS_NODEPTRS_PER_BLOCK(root
));
3226 if (slot
!= nritems
) {
3228 tree_mod_log_eb_move(root
->fs_info
, lower
, slot
+ 1,
3229 slot
, nritems
- slot
);
3230 memmove_extent_buffer(lower
,
3231 btrfs_node_key_ptr_offset(slot
+ 1),
3232 btrfs_node_key_ptr_offset(slot
),
3233 (nritems
- slot
) * sizeof(struct btrfs_key_ptr
));
3236 ret
= tree_mod_log_insert_key(root
->fs_info
, lower
, slot
,
3240 btrfs_set_node_key(lower
, key
, slot
);
3241 btrfs_set_node_blockptr(lower
, slot
, bytenr
);
3242 WARN_ON(trans
->transid
== 0);
3243 btrfs_set_node_ptr_generation(lower
, slot
, trans
->transid
);
3244 btrfs_set_header_nritems(lower
, nritems
+ 1);
3245 btrfs_mark_buffer_dirty(lower
);
3249 * split the node at the specified level in path in two.
3250 * The path is corrected to point to the appropriate node after the split
3252 * Before splitting this tries to make some room in the node by pushing
3253 * left and right, if either one works, it returns right away.
3255 * returns 0 on success and < 0 on failure
3257 static noinline
int split_node(struct btrfs_trans_handle
*trans
,
3258 struct btrfs_root
*root
,
3259 struct btrfs_path
*path
, int level
)
3261 struct extent_buffer
*c
;
3262 struct extent_buffer
*split
;
3263 struct btrfs_disk_key disk_key
;
3268 c
= path
->nodes
[level
];
3269 WARN_ON(btrfs_header_generation(c
) != trans
->transid
);
3270 if (c
== root
->node
) {
3272 * trying to split the root, lets make a new one
3274 * tree mod log: We don't log_removal old root in
3275 * insert_new_root, because that root buffer will be kept as a
3276 * normal node. We are going to log removal of half of the
3277 * elements below with tree_mod_log_eb_copy. We're holding a
3278 * tree lock on the buffer, which is why we cannot race with
3279 * other tree_mod_log users.
3281 ret
= insert_new_root(trans
, root
, path
, level
+ 1);
3285 ret
= push_nodes_for_insert(trans
, root
, path
, level
);
3286 c
= path
->nodes
[level
];
3287 if (!ret
&& btrfs_header_nritems(c
) <
3288 BTRFS_NODEPTRS_PER_BLOCK(root
) - 3)
3294 c_nritems
= btrfs_header_nritems(c
);
3295 mid
= (c_nritems
+ 1) / 2;
3296 btrfs_node_key(c
, &disk_key
, mid
);
3298 split
= btrfs_alloc_free_block(trans
, root
, root
->nodesize
, 0,
3299 root
->root_key
.objectid
,
3300 &disk_key
, level
, c
->start
, 0);
3302 return PTR_ERR(split
);
3304 root_add_used(root
, root
->nodesize
);
3306 memset_extent_buffer(split
, 0, 0, sizeof(struct btrfs_header
));
3307 btrfs_set_header_level(split
, btrfs_header_level(c
));
3308 btrfs_set_header_bytenr(split
, split
->start
);
3309 btrfs_set_header_generation(split
, trans
->transid
);
3310 btrfs_set_header_backref_rev(split
, BTRFS_MIXED_BACKREF_REV
);
3311 btrfs_set_header_owner(split
, root
->root_key
.objectid
);
3312 write_extent_buffer(split
, root
->fs_info
->fsid
,
3313 (unsigned long)btrfs_header_fsid(split
),
3315 write_extent_buffer(split
, root
->fs_info
->chunk_tree_uuid
,
3316 (unsigned long)btrfs_header_chunk_tree_uuid(split
),
3319 tree_mod_log_eb_copy(root
->fs_info
, split
, c
, 0, mid
, c_nritems
- mid
);
3320 copy_extent_buffer(split
, c
,
3321 btrfs_node_key_ptr_offset(0),
3322 btrfs_node_key_ptr_offset(mid
),
3323 (c_nritems
- mid
) * sizeof(struct btrfs_key_ptr
));
3324 btrfs_set_header_nritems(split
, c_nritems
- mid
);
3325 btrfs_set_header_nritems(c
, mid
);
3328 btrfs_mark_buffer_dirty(c
);
3329 btrfs_mark_buffer_dirty(split
);
3331 insert_ptr(trans
, root
, path
, &disk_key
, split
->start
,
3332 path
->slots
[level
+ 1] + 1, level
+ 1);
3334 if (path
->slots
[level
] >= mid
) {
3335 path
->slots
[level
] -= mid
;
3336 btrfs_tree_unlock(c
);
3337 free_extent_buffer(c
);
3338 path
->nodes
[level
] = split
;
3339 path
->slots
[level
+ 1] += 1;
3341 btrfs_tree_unlock(split
);
3342 free_extent_buffer(split
);
3348 * how many bytes are required to store the items in a leaf. start
3349 * and nr indicate which items in the leaf to check. This totals up the
3350 * space used both by the item structs and the item data
3352 static int leaf_space_used(struct extent_buffer
*l
, int start
, int nr
)
3354 struct btrfs_item
*start_item
;
3355 struct btrfs_item
*end_item
;
3356 struct btrfs_map_token token
;
3358 int nritems
= btrfs_header_nritems(l
);
3359 int end
= min(nritems
, start
+ nr
) - 1;
3363 btrfs_init_map_token(&token
);
3364 start_item
= btrfs_item_nr(l
, start
);
3365 end_item
= btrfs_item_nr(l
, end
);
3366 data_len
= btrfs_token_item_offset(l
, start_item
, &token
) +
3367 btrfs_token_item_size(l
, start_item
, &token
);
3368 data_len
= data_len
- btrfs_token_item_offset(l
, end_item
, &token
);
3369 data_len
+= sizeof(struct btrfs_item
) * nr
;
3370 WARN_ON(data_len
< 0);
3375 * The space between the end of the leaf items and
3376 * the start of the leaf data. IOW, how much room
3377 * the leaf has left for both items and data
3379 noinline
int btrfs_leaf_free_space(struct btrfs_root
*root
,
3380 struct extent_buffer
*leaf
)
3382 int nritems
= btrfs_header_nritems(leaf
);
3384 ret
= BTRFS_LEAF_DATA_SIZE(root
) - leaf_space_used(leaf
, 0, nritems
);
3386 printk(KERN_CRIT
"leaf free space ret %d, leaf data size %lu, "
3387 "used %d nritems %d\n",
3388 ret
, (unsigned long) BTRFS_LEAF_DATA_SIZE(root
),
3389 leaf_space_used(leaf
, 0, nritems
), nritems
);
3395 * min slot controls the lowest index we're willing to push to the
3396 * right. We'll push up to and including min_slot, but no lower
3398 static noinline
int __push_leaf_right(struct btrfs_trans_handle
*trans
,
3399 struct btrfs_root
*root
,
3400 struct btrfs_path
*path
,
3401 int data_size
, int empty
,
3402 struct extent_buffer
*right
,
3403 int free_space
, u32 left_nritems
,
3406 struct extent_buffer
*left
= path
->nodes
[0];
3407 struct extent_buffer
*upper
= path
->nodes
[1];
3408 struct btrfs_map_token token
;
3409 struct btrfs_disk_key disk_key
;
3414 struct btrfs_item
*item
;
3420 btrfs_init_map_token(&token
);
3425 nr
= max_t(u32
, 1, min_slot
);
3427 if (path
->slots
[0] >= left_nritems
)
3428 push_space
+= data_size
;
3430 slot
= path
->slots
[1];
3431 i
= left_nritems
- 1;
3433 item
= btrfs_item_nr(left
, i
);
3435 if (!empty
&& push_items
> 0) {
3436 if (path
->slots
[0] > i
)
3438 if (path
->slots
[0] == i
) {
3439 int space
= btrfs_leaf_free_space(root
, left
);
3440 if (space
+ push_space
* 2 > free_space
)
3445 if (path
->slots
[0] == i
)
3446 push_space
+= data_size
;
3448 this_item_size
= btrfs_item_size(left
, item
);
3449 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
3453 push_space
+= this_item_size
+ sizeof(*item
);
3459 if (push_items
== 0)
3462 WARN_ON(!empty
&& push_items
== left_nritems
);
3464 /* push left to right */
3465 right_nritems
= btrfs_header_nritems(right
);
3467 push_space
= btrfs_item_end_nr(left
, left_nritems
- push_items
);
3468 push_space
-= leaf_data_end(root
, left
);
3470 /* make room in the right data area */
3471 data_end
= leaf_data_end(root
, right
);
3472 memmove_extent_buffer(right
,
3473 btrfs_leaf_data(right
) + data_end
- push_space
,
3474 btrfs_leaf_data(right
) + data_end
,
3475 BTRFS_LEAF_DATA_SIZE(root
) - data_end
);
3477 /* copy from the left data area */
3478 copy_extent_buffer(right
, left
, btrfs_leaf_data(right
) +
3479 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
3480 btrfs_leaf_data(left
) + leaf_data_end(root
, left
),
3483 memmove_extent_buffer(right
, btrfs_item_nr_offset(push_items
),
3484 btrfs_item_nr_offset(0),
3485 right_nritems
* sizeof(struct btrfs_item
));
3487 /* copy the items from left to right */
3488 copy_extent_buffer(right
, left
, btrfs_item_nr_offset(0),
3489 btrfs_item_nr_offset(left_nritems
- push_items
),
3490 push_items
* sizeof(struct btrfs_item
));
3492 /* update the item pointers */
3493 right_nritems
+= push_items
;
3494 btrfs_set_header_nritems(right
, right_nritems
);
3495 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
3496 for (i
= 0; i
< right_nritems
; i
++) {
3497 item
= btrfs_item_nr(right
, i
);
3498 push_space
-= btrfs_token_item_size(right
, item
, &token
);
3499 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
3502 left_nritems
-= push_items
;
3503 btrfs_set_header_nritems(left
, left_nritems
);
3506 btrfs_mark_buffer_dirty(left
);
3508 clean_tree_block(trans
, root
, left
);
3510 btrfs_mark_buffer_dirty(right
);
3512 btrfs_item_key(right
, &disk_key
, 0);
3513 btrfs_set_node_key(upper
, &disk_key
, slot
+ 1);
3514 btrfs_mark_buffer_dirty(upper
);
3516 /* then fixup the leaf pointer in the path */
3517 if (path
->slots
[0] >= left_nritems
) {
3518 path
->slots
[0] -= left_nritems
;
3519 if (btrfs_header_nritems(path
->nodes
[0]) == 0)
3520 clean_tree_block(trans
, root
, path
->nodes
[0]);
3521 btrfs_tree_unlock(path
->nodes
[0]);
3522 free_extent_buffer(path
->nodes
[0]);
3523 path
->nodes
[0] = right
;
3524 path
->slots
[1] += 1;
3526 btrfs_tree_unlock(right
);
3527 free_extent_buffer(right
);
3532 btrfs_tree_unlock(right
);
3533 free_extent_buffer(right
);
3538 * push some data in the path leaf to the right, trying to free up at
3539 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3541 * returns 1 if the push failed because the other node didn't have enough
3542 * room, 0 if everything worked out and < 0 if there were major errors.
3544 * this will push starting from min_slot to the end of the leaf. It won't
3545 * push any slot lower than min_slot
3547 static int push_leaf_right(struct btrfs_trans_handle
*trans
, struct btrfs_root
3548 *root
, struct btrfs_path
*path
,
3549 int min_data_size
, int data_size
,
3550 int empty
, u32 min_slot
)
3552 struct extent_buffer
*left
= path
->nodes
[0];
3553 struct extent_buffer
*right
;
3554 struct extent_buffer
*upper
;
3560 if (!path
->nodes
[1])
3563 slot
= path
->slots
[1];
3564 upper
= path
->nodes
[1];
3565 if (slot
>= btrfs_header_nritems(upper
) - 1)
3568 btrfs_assert_tree_locked(path
->nodes
[1]);
3570 right
= read_node_slot(root
, upper
, slot
+ 1);
3574 btrfs_tree_lock(right
);
3575 btrfs_set_lock_blocking(right
);
3577 free_space
= btrfs_leaf_free_space(root
, right
);
3578 if (free_space
< data_size
)
3581 /* cow and double check */
3582 ret
= btrfs_cow_block(trans
, root
, right
, upper
,
3587 free_space
= btrfs_leaf_free_space(root
, right
);
3588 if (free_space
< data_size
)
3591 left_nritems
= btrfs_header_nritems(left
);
3592 if (left_nritems
== 0)
3595 return __push_leaf_right(trans
, root
, path
, min_data_size
, empty
,
3596 right
, free_space
, left_nritems
, min_slot
);
3598 btrfs_tree_unlock(right
);
3599 free_extent_buffer(right
);
3604 * push some data in the path leaf to the left, trying to free up at
3605 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3607 * max_slot can put a limit on how far into the leaf we'll push items. The
3608 * item at 'max_slot' won't be touched. Use (u32)-1 to make us do all the
3611 static noinline
int __push_leaf_left(struct btrfs_trans_handle
*trans
,
3612 struct btrfs_root
*root
,
3613 struct btrfs_path
*path
, int data_size
,
3614 int empty
, struct extent_buffer
*left
,
3615 int free_space
, u32 right_nritems
,
3618 struct btrfs_disk_key disk_key
;
3619 struct extent_buffer
*right
= path
->nodes
[0];
3623 struct btrfs_item
*item
;
3624 u32 old_left_nritems
;
3628 u32 old_left_item_size
;
3629 struct btrfs_map_token token
;
3631 btrfs_init_map_token(&token
);
3634 nr
= min(right_nritems
, max_slot
);
3636 nr
= min(right_nritems
- 1, max_slot
);
3638 for (i
= 0; i
< nr
; i
++) {
3639 item
= btrfs_item_nr(right
, i
);
3641 if (!empty
&& push_items
> 0) {
3642 if (path
->slots
[0] < i
)
3644 if (path
->slots
[0] == i
) {
3645 int space
= btrfs_leaf_free_space(root
, right
);
3646 if (space
+ push_space
* 2 > free_space
)
3651 if (path
->slots
[0] == i
)
3652 push_space
+= data_size
;
3654 this_item_size
= btrfs_item_size(right
, item
);
3655 if (this_item_size
+ sizeof(*item
) + push_space
> free_space
)
3659 push_space
+= this_item_size
+ sizeof(*item
);
3662 if (push_items
== 0) {
3666 if (!empty
&& push_items
== btrfs_header_nritems(right
))
3669 /* push data from right to left */
3670 copy_extent_buffer(left
, right
,
3671 btrfs_item_nr_offset(btrfs_header_nritems(left
)),
3672 btrfs_item_nr_offset(0),
3673 push_items
* sizeof(struct btrfs_item
));
3675 push_space
= BTRFS_LEAF_DATA_SIZE(root
) -
3676 btrfs_item_offset_nr(right
, push_items
- 1);
3678 copy_extent_buffer(left
, right
, btrfs_leaf_data(left
) +
3679 leaf_data_end(root
, left
) - push_space
,
3680 btrfs_leaf_data(right
) +
3681 btrfs_item_offset_nr(right
, push_items
- 1),
3683 old_left_nritems
= btrfs_header_nritems(left
);
3684 BUG_ON(old_left_nritems
<= 0);
3686 old_left_item_size
= btrfs_item_offset_nr(left
, old_left_nritems
- 1);
3687 for (i
= old_left_nritems
; i
< old_left_nritems
+ push_items
; i
++) {
3690 item
= btrfs_item_nr(left
, i
);
3692 ioff
= btrfs_token_item_offset(left
, item
, &token
);
3693 btrfs_set_token_item_offset(left
, item
,
3694 ioff
- (BTRFS_LEAF_DATA_SIZE(root
) - old_left_item_size
),
3697 btrfs_set_header_nritems(left
, old_left_nritems
+ push_items
);
3699 /* fixup right node */
3700 if (push_items
> right_nritems
)
3701 WARN(1, KERN_CRIT
"push items %d nr %u\n", push_items
,
3704 if (push_items
< right_nritems
) {
3705 push_space
= btrfs_item_offset_nr(right
, push_items
- 1) -
3706 leaf_data_end(root
, right
);
3707 memmove_extent_buffer(right
, btrfs_leaf_data(right
) +
3708 BTRFS_LEAF_DATA_SIZE(root
) - push_space
,
3709 btrfs_leaf_data(right
) +
3710 leaf_data_end(root
, right
), push_space
);
3712 memmove_extent_buffer(right
, btrfs_item_nr_offset(0),
3713 btrfs_item_nr_offset(push_items
),
3714 (btrfs_header_nritems(right
) - push_items
) *
3715 sizeof(struct btrfs_item
));
3717 right_nritems
-= push_items
;
3718 btrfs_set_header_nritems(right
, right_nritems
);
3719 push_space
= BTRFS_LEAF_DATA_SIZE(root
);
3720 for (i
= 0; i
< right_nritems
; i
++) {
3721 item
= btrfs_item_nr(right
, i
);
3723 push_space
= push_space
- btrfs_token_item_size(right
,
3725 btrfs_set_token_item_offset(right
, item
, push_space
, &token
);
3728 btrfs_mark_buffer_dirty(left
);
3730 btrfs_mark_buffer_dirty(right
);
3732 clean_tree_block(trans
, root
, right
);
3734 btrfs_item_key(right
, &disk_key
, 0);
3735 fixup_low_keys(root
, path
, &disk_key
, 1);
3737 /* then fixup the leaf pointer in the path */
3738 if (path
->slots
[0] < push_items
) {
3739 path
->slots
[0] += old_left_nritems
;
3740 btrfs_tree_unlock(path
->nodes
[0]);
3741 free_extent_buffer(path
->nodes
[0]);
3742 path
->nodes
[0] = left
;
3743 path
->slots
[1] -= 1;
3745 btrfs_tree_unlock(left
);
3746 free_extent_buffer(left
);
3747 path
->slots
[0] -= push_items
;
3749 BUG_ON(path
->slots
[0] < 0);
3752 btrfs_tree_unlock(left
);
3753 free_extent_buffer(left
);
3758 * push some data in the path leaf to the left, trying to free up at
3759 * least data_size bytes. returns zero if the push worked, nonzero otherwise
3761 * max_slot can put a limit on how far into the leaf we'll push items. The
3762 * item at 'max_slot' won't be touched. Use (u32)-1 to make us push all the
3765 static int push_leaf_left(struct btrfs_trans_handle
*trans
, struct btrfs_root
3766 *root
, struct btrfs_path
*path
, int min_data_size
,
3767 int data_size
, int empty
, u32 max_slot
)
3769 struct extent_buffer
*right
= path
->nodes
[0];
3770 struct extent_buffer
*left
;
3776 slot
= path
->slots
[1];
3779 if (!path
->nodes
[1])
3782 right_nritems
= btrfs_header_nritems(right
);
3783 if (right_nritems
== 0)
3786 btrfs_assert_tree_locked(path
->nodes
[1]);
3788 left
= read_node_slot(root
, path
->nodes
[1], slot
- 1);
3792 btrfs_tree_lock(left
);
3793 btrfs_set_lock_blocking(left
);
3795 free_space
= btrfs_leaf_free_space(root
, left
);
3796 if (free_space
< data_size
) {
3801 /* cow and double check */
3802 ret
= btrfs_cow_block(trans
, root
, left
,
3803 path
->nodes
[1], slot
- 1, &left
);
3805 /* we hit -ENOSPC, but it isn't fatal here */
3811 free_space
= btrfs_leaf_free_space(root
, left
);
3812 if (free_space
< data_size
) {
3817 return __push_leaf_left(trans
, root
, path
, min_data_size
,
3818 empty
, left
, free_space
, right_nritems
,
3821 btrfs_tree_unlock(left
);
3822 free_extent_buffer(left
);
3827 * split the path's leaf in two, making sure there is at least data_size
3828 * available for the resulting leaf level of the path.
3830 static noinline
void copy_for_split(struct btrfs_trans_handle
*trans
,
3831 struct btrfs_root
*root
,
3832 struct btrfs_path
*path
,
3833 struct extent_buffer
*l
,
3834 struct extent_buffer
*right
,
3835 int slot
, int mid
, int nritems
)
3840 struct btrfs_disk_key disk_key
;
3841 struct btrfs_map_token token
;
3843 btrfs_init_map_token(&token
);
3845 nritems
= nritems
- mid
;
3846 btrfs_set_header_nritems(right
, nritems
);
3847 data_copy_size
= btrfs_item_end_nr(l
, mid
) - leaf_data_end(root
, l
);
3849 copy_extent_buffer(right
, l
, btrfs_item_nr_offset(0),
3850 btrfs_item_nr_offset(mid
),
3851 nritems
* sizeof(struct btrfs_item
));
3853 copy_extent_buffer(right
, l
,
3854 btrfs_leaf_data(right
) + BTRFS_LEAF_DATA_SIZE(root
) -
3855 data_copy_size
, btrfs_leaf_data(l
) +
3856 leaf_data_end(root
, l
), data_copy_size
);
3858 rt_data_off
= BTRFS_LEAF_DATA_SIZE(root
) -
3859 btrfs_item_end_nr(l
, mid
);
3861 for (i
= 0; i
< nritems
; i
++) {
3862 struct btrfs_item
*item
= btrfs_item_nr(right
, i
);
3865 ioff
= btrfs_token_item_offset(right
, item
, &token
);
3866 btrfs_set_token_item_offset(right
, item
,
3867 ioff
+ rt_data_off
, &token
);
3870 btrfs_set_header_nritems(l
, mid
);
3871 btrfs_item_key(right
, &disk_key
, 0);
3872 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
3873 path
->slots
[1] + 1, 1);
3875 btrfs_mark_buffer_dirty(right
);
3876 btrfs_mark_buffer_dirty(l
);
3877 BUG_ON(path
->slots
[0] != slot
);
3880 btrfs_tree_unlock(path
->nodes
[0]);
3881 free_extent_buffer(path
->nodes
[0]);
3882 path
->nodes
[0] = right
;
3883 path
->slots
[0] -= mid
;
3884 path
->slots
[1] += 1;
3886 btrfs_tree_unlock(right
);
3887 free_extent_buffer(right
);
3890 BUG_ON(path
->slots
[0] < 0);
3894 * double splits happen when we need to insert a big item in the middle
3895 * of a leaf. A double split can leave us with 3 mostly empty leaves:
3896 * leaf: [ slots 0 - N] [ our target ] [ N + 1 - total in leaf ]
3899 * We avoid this by trying to push the items on either side of our target
3900 * into the adjacent leaves. If all goes well we can avoid the double split
3903 static noinline
int push_for_double_split(struct btrfs_trans_handle
*trans
,
3904 struct btrfs_root
*root
,
3905 struct btrfs_path
*path
,
3913 slot
= path
->slots
[0];
3916 * try to push all the items after our slot into the
3919 ret
= push_leaf_right(trans
, root
, path
, 1, data_size
, 0, slot
);
3926 nritems
= btrfs_header_nritems(path
->nodes
[0]);
3928 * our goal is to get our slot at the start or end of a leaf. If
3929 * we've done so we're done
3931 if (path
->slots
[0] == 0 || path
->slots
[0] == nritems
)
3934 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
3937 /* try to push all the items before our slot into the next leaf */
3938 slot
= path
->slots
[0];
3939 ret
= push_leaf_left(trans
, root
, path
, 1, data_size
, 0, slot
);
3952 * split the path's leaf in two, making sure there is at least data_size
3953 * available for the resulting leaf level of the path.
3955 * returns 0 if all went well and < 0 on failure.
3957 static noinline
int split_leaf(struct btrfs_trans_handle
*trans
,
3958 struct btrfs_root
*root
,
3959 struct btrfs_key
*ins_key
,
3960 struct btrfs_path
*path
, int data_size
,
3963 struct btrfs_disk_key disk_key
;
3964 struct extent_buffer
*l
;
3968 struct extent_buffer
*right
;
3972 int num_doubles
= 0;
3973 int tried_avoid_double
= 0;
3976 slot
= path
->slots
[0];
3977 if (extend
&& data_size
+ btrfs_item_size_nr(l
, slot
) +
3978 sizeof(struct btrfs_item
) > BTRFS_LEAF_DATA_SIZE(root
))
3981 /* first try to make some room by pushing left and right */
3982 if (data_size
&& path
->nodes
[1]) {
3983 wret
= push_leaf_right(trans
, root
, path
, data_size
,
3988 wret
= push_leaf_left(trans
, root
, path
, data_size
,
3989 data_size
, 0, (u32
)-1);
3995 /* did the pushes work? */
3996 if (btrfs_leaf_free_space(root
, l
) >= data_size
)
4000 if (!path
->nodes
[1]) {
4001 ret
= insert_new_root(trans
, root
, path
, 1);
4008 slot
= path
->slots
[0];
4009 nritems
= btrfs_header_nritems(l
);
4010 mid
= (nritems
+ 1) / 2;
4014 leaf_space_used(l
, mid
, nritems
- mid
) + data_size
>
4015 BTRFS_LEAF_DATA_SIZE(root
)) {
4016 if (slot
>= nritems
) {
4020 if (mid
!= nritems
&&
4021 leaf_space_used(l
, mid
, nritems
- mid
) +
4022 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
4023 if (data_size
&& !tried_avoid_double
)
4024 goto push_for_double
;
4030 if (leaf_space_used(l
, 0, mid
) + data_size
>
4031 BTRFS_LEAF_DATA_SIZE(root
)) {
4032 if (!extend
&& data_size
&& slot
== 0) {
4034 } else if ((extend
|| !data_size
) && slot
== 0) {
4038 if (mid
!= nritems
&&
4039 leaf_space_used(l
, mid
, nritems
- mid
) +
4040 data_size
> BTRFS_LEAF_DATA_SIZE(root
)) {
4041 if (data_size
&& !tried_avoid_double
)
4042 goto push_for_double
;
4050 btrfs_cpu_key_to_disk(&disk_key
, ins_key
);
4052 btrfs_item_key(l
, &disk_key
, mid
);
4054 right
= btrfs_alloc_free_block(trans
, root
, root
->leafsize
, 0,
4055 root
->root_key
.objectid
,
4056 &disk_key
, 0, l
->start
, 0);
4058 return PTR_ERR(right
);
4060 root_add_used(root
, root
->leafsize
);
4062 memset_extent_buffer(right
, 0, 0, sizeof(struct btrfs_header
));
4063 btrfs_set_header_bytenr(right
, right
->start
);
4064 btrfs_set_header_generation(right
, trans
->transid
);
4065 btrfs_set_header_backref_rev(right
, BTRFS_MIXED_BACKREF_REV
);
4066 btrfs_set_header_owner(right
, root
->root_key
.objectid
);
4067 btrfs_set_header_level(right
, 0);
4068 write_extent_buffer(right
, root
->fs_info
->fsid
,
4069 (unsigned long)btrfs_header_fsid(right
),
4072 write_extent_buffer(right
, root
->fs_info
->chunk_tree_uuid
,
4073 (unsigned long)btrfs_header_chunk_tree_uuid(right
),
4078 btrfs_set_header_nritems(right
, 0);
4079 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
4080 path
->slots
[1] + 1, 1);
4081 btrfs_tree_unlock(path
->nodes
[0]);
4082 free_extent_buffer(path
->nodes
[0]);
4083 path
->nodes
[0] = right
;
4085 path
->slots
[1] += 1;
4087 btrfs_set_header_nritems(right
, 0);
4088 insert_ptr(trans
, root
, path
, &disk_key
, right
->start
,
4090 btrfs_tree_unlock(path
->nodes
[0]);
4091 free_extent_buffer(path
->nodes
[0]);
4092 path
->nodes
[0] = right
;
4094 if (path
->slots
[1] == 0)
4095 fixup_low_keys(root
, path
, &disk_key
, 1);
4097 btrfs_mark_buffer_dirty(right
);
4101 copy_for_split(trans
, root
, path
, l
, right
, slot
, mid
, nritems
);
4104 BUG_ON(num_doubles
!= 0);
4112 push_for_double_split(trans
, root
, path
, data_size
);
4113 tried_avoid_double
= 1;
4114 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= data_size
)
4119 static noinline
int setup_leaf_for_split(struct btrfs_trans_handle
*trans
,
4120 struct btrfs_root
*root
,
4121 struct btrfs_path
*path
, int ins_len
)
4123 struct btrfs_key key
;
4124 struct extent_buffer
*leaf
;
4125 struct btrfs_file_extent_item
*fi
;
4130 leaf
= path
->nodes
[0];
4131 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4133 BUG_ON(key
.type
!= BTRFS_EXTENT_DATA_KEY
&&
4134 key
.type
!= BTRFS_EXTENT_CSUM_KEY
);
4136 if (btrfs_leaf_free_space(root
, leaf
) >= ins_len
)
4139 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
4140 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
4141 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
4142 struct btrfs_file_extent_item
);
4143 extent_len
= btrfs_file_extent_num_bytes(leaf
, fi
);
4145 btrfs_release_path(path
);
4147 path
->keep_locks
= 1;
4148 path
->search_for_split
= 1;
4149 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
4150 path
->search_for_split
= 0;
4155 leaf
= path
->nodes
[0];
4156 /* if our item isn't there or got smaller, return now */
4157 if (ret
> 0 || item_size
!= btrfs_item_size_nr(leaf
, path
->slots
[0]))
4160 /* the leaf has changed, it now has room. return now */
4161 if (btrfs_leaf_free_space(root
, path
->nodes
[0]) >= ins_len
)
4164 if (key
.type
== BTRFS_EXTENT_DATA_KEY
) {
4165 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
4166 struct btrfs_file_extent_item
);
4167 if (extent_len
!= btrfs_file_extent_num_bytes(leaf
, fi
))
4171 btrfs_set_path_blocking(path
);
4172 ret
= split_leaf(trans
, root
, &key
, path
, ins_len
, 1);
4176 path
->keep_locks
= 0;
4177 btrfs_unlock_up_safe(path
, 1);
4180 path
->keep_locks
= 0;
4184 static noinline
int split_item(struct btrfs_trans_handle
*trans
,
4185 struct btrfs_root
*root
,
4186 struct btrfs_path
*path
,
4187 struct btrfs_key
*new_key
,
4188 unsigned long split_offset
)
4190 struct extent_buffer
*leaf
;
4191 struct btrfs_item
*item
;
4192 struct btrfs_item
*new_item
;
4198 struct btrfs_disk_key disk_key
;
4200 leaf
= path
->nodes
[0];
4201 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < sizeof(struct btrfs_item
));
4203 btrfs_set_path_blocking(path
);
4205 item
= btrfs_item_nr(leaf
, path
->slots
[0]);
4206 orig_offset
= btrfs_item_offset(leaf
, item
);
4207 item_size
= btrfs_item_size(leaf
, item
);
4209 buf
= kmalloc(item_size
, GFP_NOFS
);
4213 read_extent_buffer(leaf
, buf
, btrfs_item_ptr_offset(leaf
,
4214 path
->slots
[0]), item_size
);
4216 slot
= path
->slots
[0] + 1;
4217 nritems
= btrfs_header_nritems(leaf
);
4218 if (slot
!= nritems
) {
4219 /* shift the items */
4220 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ 1),
4221 btrfs_item_nr_offset(slot
),
4222 (nritems
- slot
) * sizeof(struct btrfs_item
));
4225 btrfs_cpu_key_to_disk(&disk_key
, new_key
);
4226 btrfs_set_item_key(leaf
, &disk_key
, slot
);
4228 new_item
= btrfs_item_nr(leaf
, slot
);
4230 btrfs_set_item_offset(leaf
, new_item
, orig_offset
);
4231 btrfs_set_item_size(leaf
, new_item
, item_size
- split_offset
);
4233 btrfs_set_item_offset(leaf
, item
,
4234 orig_offset
+ item_size
- split_offset
);
4235 btrfs_set_item_size(leaf
, item
, split_offset
);
4237 btrfs_set_header_nritems(leaf
, nritems
+ 1);
4239 /* write the data for the start of the original item */
4240 write_extent_buffer(leaf
, buf
,
4241 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
4244 /* write the data for the new item */
4245 write_extent_buffer(leaf
, buf
+ split_offset
,
4246 btrfs_item_ptr_offset(leaf
, slot
),
4247 item_size
- split_offset
);
4248 btrfs_mark_buffer_dirty(leaf
);
4250 BUG_ON(btrfs_leaf_free_space(root
, leaf
) < 0);
4256 * This function splits a single item into two items,
4257 * giving 'new_key' to the new item and splitting the
4258 * old one at split_offset (from the start of the item).
4260 * The path may be released by this operation. After
4261 * the split, the path is pointing to the old item. The
4262 * new item is going to be in the same node as the old one.
4264 * Note, the item being split must be smaller enough to live alone on
4265 * a tree block with room for one extra struct btrfs_item
4267 * This allows us to split the item in place, keeping a lock on the
4268 * leaf the entire time.
4270 int btrfs_split_item(struct btrfs_trans_handle
*trans
,
4271 struct btrfs_root
*root
,
4272 struct btrfs_path
*path
,
4273 struct btrfs_key
*new_key
,
4274 unsigned long split_offset
)
4277 ret
= setup_leaf_for_split(trans
, root
, path
,
4278 sizeof(struct btrfs_item
));
4282 ret
= split_item(trans
, root
, path
, new_key
, split_offset
);
4287 * This function duplicate a item, giving 'new_key' to the new item.
4288 * It guarantees both items live in the same tree leaf and the new item
4289 * is contiguous with the original item.
4291 * This allows us to split file extent in place, keeping a lock on the
4292 * leaf the entire time.
4294 int btrfs_duplicate_item(struct btrfs_trans_handle
*trans
,
4295 struct btrfs_root
*root
,
4296 struct btrfs_path
*path
,
4297 struct btrfs_key
*new_key
)
4299 struct extent_buffer
*leaf
;
4303 leaf
= path
->nodes
[0];
4304 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
4305 ret
= setup_leaf_for_split(trans
, root
, path
,
4306 item_size
+ sizeof(struct btrfs_item
));
4311 setup_items_for_insert(root
, path
, new_key
, &item_size
,
4312 item_size
, item_size
+
4313 sizeof(struct btrfs_item
), 1);
4314 leaf
= path
->nodes
[0];
4315 memcpy_extent_buffer(leaf
,
4316 btrfs_item_ptr_offset(leaf
, path
->slots
[0]),
4317 btrfs_item_ptr_offset(leaf
, path
->slots
[0] - 1),
4323 * make the item pointed to by the path smaller. new_size indicates
4324 * how small to make it, and from_end tells us if we just chop bytes
4325 * off the end of the item or if we shift the item to chop bytes off
4328 void btrfs_truncate_item(struct btrfs_root
*root
, struct btrfs_path
*path
,
4329 u32 new_size
, int from_end
)
4332 struct extent_buffer
*leaf
;
4333 struct btrfs_item
*item
;
4335 unsigned int data_end
;
4336 unsigned int old_data_start
;
4337 unsigned int old_size
;
4338 unsigned int size_diff
;
4340 struct btrfs_map_token token
;
4342 btrfs_init_map_token(&token
);
4344 leaf
= path
->nodes
[0];
4345 slot
= path
->slots
[0];
4347 old_size
= btrfs_item_size_nr(leaf
, slot
);
4348 if (old_size
== new_size
)
4351 nritems
= btrfs_header_nritems(leaf
);
4352 data_end
= leaf_data_end(root
, leaf
);
4354 old_data_start
= btrfs_item_offset_nr(leaf
, slot
);
4356 size_diff
= old_size
- new_size
;
4359 BUG_ON(slot
>= nritems
);
4362 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4364 /* first correct the data pointers */
4365 for (i
= slot
; i
< nritems
; i
++) {
4367 item
= btrfs_item_nr(leaf
, i
);
4369 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4370 btrfs_set_token_item_offset(leaf
, item
,
4371 ioff
+ size_diff
, &token
);
4374 /* shift the data */
4376 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4377 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
4378 data_end
, old_data_start
+ new_size
- data_end
);
4380 struct btrfs_disk_key disk_key
;
4383 btrfs_item_key(leaf
, &disk_key
, slot
);
4385 if (btrfs_disk_key_type(&disk_key
) == BTRFS_EXTENT_DATA_KEY
) {
4387 struct btrfs_file_extent_item
*fi
;
4389 fi
= btrfs_item_ptr(leaf
, slot
,
4390 struct btrfs_file_extent_item
);
4391 fi
= (struct btrfs_file_extent_item
*)(
4392 (unsigned long)fi
- size_diff
);
4394 if (btrfs_file_extent_type(leaf
, fi
) ==
4395 BTRFS_FILE_EXTENT_INLINE
) {
4396 ptr
= btrfs_item_ptr_offset(leaf
, slot
);
4397 memmove_extent_buffer(leaf
, ptr
,
4399 offsetof(struct btrfs_file_extent_item
,
4404 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4405 data_end
+ size_diff
, btrfs_leaf_data(leaf
) +
4406 data_end
, old_data_start
- data_end
);
4408 offset
= btrfs_disk_key_offset(&disk_key
);
4409 btrfs_set_disk_key_offset(&disk_key
, offset
+ size_diff
);
4410 btrfs_set_item_key(leaf
, &disk_key
, slot
);
4412 fixup_low_keys(root
, path
, &disk_key
, 1);
4415 item
= btrfs_item_nr(leaf
, slot
);
4416 btrfs_set_item_size(leaf
, item
, new_size
);
4417 btrfs_mark_buffer_dirty(leaf
);
4419 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4420 btrfs_print_leaf(root
, leaf
);
4426 * make the item pointed to by the path bigger, data_size is the added size.
4428 void btrfs_extend_item(struct btrfs_root
*root
, struct btrfs_path
*path
,
4432 struct extent_buffer
*leaf
;
4433 struct btrfs_item
*item
;
4435 unsigned int data_end
;
4436 unsigned int old_data
;
4437 unsigned int old_size
;
4439 struct btrfs_map_token token
;
4441 btrfs_init_map_token(&token
);
4443 leaf
= path
->nodes
[0];
4445 nritems
= btrfs_header_nritems(leaf
);
4446 data_end
= leaf_data_end(root
, leaf
);
4448 if (btrfs_leaf_free_space(root
, leaf
) < data_size
) {
4449 btrfs_print_leaf(root
, leaf
);
4452 slot
= path
->slots
[0];
4453 old_data
= btrfs_item_end_nr(leaf
, slot
);
4456 if (slot
>= nritems
) {
4457 btrfs_print_leaf(root
, leaf
);
4458 printk(KERN_CRIT
"slot %d too large, nritems %d\n",
4464 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4466 /* first correct the data pointers */
4467 for (i
= slot
; i
< nritems
; i
++) {
4469 item
= btrfs_item_nr(leaf
, i
);
4471 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4472 btrfs_set_token_item_offset(leaf
, item
,
4473 ioff
- data_size
, &token
);
4476 /* shift the data */
4477 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4478 data_end
- data_size
, btrfs_leaf_data(leaf
) +
4479 data_end
, old_data
- data_end
);
4481 data_end
= old_data
;
4482 old_size
= btrfs_item_size_nr(leaf
, slot
);
4483 item
= btrfs_item_nr(leaf
, slot
);
4484 btrfs_set_item_size(leaf
, item
, old_size
+ data_size
);
4485 btrfs_mark_buffer_dirty(leaf
);
4487 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4488 btrfs_print_leaf(root
, leaf
);
4494 * this is a helper for btrfs_insert_empty_items, the main goal here is
4495 * to save stack depth by doing the bulk of the work in a function
4496 * that doesn't call btrfs_search_slot
4498 void setup_items_for_insert(struct btrfs_root
*root
, struct btrfs_path
*path
,
4499 struct btrfs_key
*cpu_key
, u32
*data_size
,
4500 u32 total_data
, u32 total_size
, int nr
)
4502 struct btrfs_item
*item
;
4505 unsigned int data_end
;
4506 struct btrfs_disk_key disk_key
;
4507 struct extent_buffer
*leaf
;
4509 struct btrfs_map_token token
;
4511 btrfs_init_map_token(&token
);
4513 leaf
= path
->nodes
[0];
4514 slot
= path
->slots
[0];
4516 nritems
= btrfs_header_nritems(leaf
);
4517 data_end
= leaf_data_end(root
, leaf
);
4519 if (btrfs_leaf_free_space(root
, leaf
) < total_size
) {
4520 btrfs_print_leaf(root
, leaf
);
4521 printk(KERN_CRIT
"not enough freespace need %u have %d\n",
4522 total_size
, btrfs_leaf_free_space(root
, leaf
));
4526 if (slot
!= nritems
) {
4527 unsigned int old_data
= btrfs_item_end_nr(leaf
, slot
);
4529 if (old_data
< data_end
) {
4530 btrfs_print_leaf(root
, leaf
);
4531 printk(KERN_CRIT
"slot %d old_data %d data_end %d\n",
4532 slot
, old_data
, data_end
);
4536 * item0..itemN ... dataN.offset..dataN.size .. data0.size
4538 /* first correct the data pointers */
4539 for (i
= slot
; i
< nritems
; i
++) {
4542 item
= btrfs_item_nr(leaf
, i
);
4543 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4544 btrfs_set_token_item_offset(leaf
, item
,
4545 ioff
- total_data
, &token
);
4547 /* shift the items */
4548 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
+ nr
),
4549 btrfs_item_nr_offset(slot
),
4550 (nritems
- slot
) * sizeof(struct btrfs_item
));
4552 /* shift the data */
4553 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4554 data_end
- total_data
, btrfs_leaf_data(leaf
) +
4555 data_end
, old_data
- data_end
);
4556 data_end
= old_data
;
4559 /* setup the item for the new data */
4560 for (i
= 0; i
< nr
; i
++) {
4561 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
+ i
);
4562 btrfs_set_item_key(leaf
, &disk_key
, slot
+ i
);
4563 item
= btrfs_item_nr(leaf
, slot
+ i
);
4564 btrfs_set_token_item_offset(leaf
, item
,
4565 data_end
- data_size
[i
], &token
);
4566 data_end
-= data_size
[i
];
4567 btrfs_set_token_item_size(leaf
, item
, data_size
[i
], &token
);
4570 btrfs_set_header_nritems(leaf
, nritems
+ nr
);
4573 btrfs_cpu_key_to_disk(&disk_key
, cpu_key
);
4574 fixup_low_keys(root
, path
, &disk_key
, 1);
4576 btrfs_unlock_up_safe(path
, 1);
4577 btrfs_mark_buffer_dirty(leaf
);
4579 if (btrfs_leaf_free_space(root
, leaf
) < 0) {
4580 btrfs_print_leaf(root
, leaf
);
4586 * Given a key and some data, insert items into the tree.
4587 * This does all the path init required, making room in the tree if needed.
4589 int btrfs_insert_empty_items(struct btrfs_trans_handle
*trans
,
4590 struct btrfs_root
*root
,
4591 struct btrfs_path
*path
,
4592 struct btrfs_key
*cpu_key
, u32
*data_size
,
4601 for (i
= 0; i
< nr
; i
++)
4602 total_data
+= data_size
[i
];
4604 total_size
= total_data
+ (nr
* sizeof(struct btrfs_item
));
4605 ret
= btrfs_search_slot(trans
, root
, cpu_key
, path
, total_size
, 1);
4611 slot
= path
->slots
[0];
4614 setup_items_for_insert(root
, path
, cpu_key
, data_size
,
4615 total_data
, total_size
, nr
);
4620 * Given a key and some data, insert an item into the tree.
4621 * This does all the path init required, making room in the tree if needed.
4623 int btrfs_insert_item(struct btrfs_trans_handle
*trans
, struct btrfs_root
4624 *root
, struct btrfs_key
*cpu_key
, void *data
, u32
4628 struct btrfs_path
*path
;
4629 struct extent_buffer
*leaf
;
4632 path
= btrfs_alloc_path();
4635 ret
= btrfs_insert_empty_item(trans
, root
, path
, cpu_key
, data_size
);
4637 leaf
= path
->nodes
[0];
4638 ptr
= btrfs_item_ptr_offset(leaf
, path
->slots
[0]);
4639 write_extent_buffer(leaf
, data
, ptr
, data_size
);
4640 btrfs_mark_buffer_dirty(leaf
);
4642 btrfs_free_path(path
);
4647 * delete the pointer from a given node.
4649 * the tree should have been previously balanced so the deletion does not
4652 static void del_ptr(struct btrfs_root
*root
, struct btrfs_path
*path
,
4653 int level
, int slot
)
4655 struct extent_buffer
*parent
= path
->nodes
[level
];
4659 nritems
= btrfs_header_nritems(parent
);
4660 if (slot
!= nritems
- 1) {
4662 tree_mod_log_eb_move(root
->fs_info
, parent
, slot
,
4663 slot
+ 1, nritems
- slot
- 1);
4664 memmove_extent_buffer(parent
,
4665 btrfs_node_key_ptr_offset(slot
),
4666 btrfs_node_key_ptr_offset(slot
+ 1),
4667 sizeof(struct btrfs_key_ptr
) *
4668 (nritems
- slot
- 1));
4670 ret
= tree_mod_log_insert_key(root
->fs_info
, parent
, slot
,
4671 MOD_LOG_KEY_REMOVE
);
4676 btrfs_set_header_nritems(parent
, nritems
);
4677 if (nritems
== 0 && parent
== root
->node
) {
4678 BUG_ON(btrfs_header_level(root
->node
) != 1);
4679 /* just turn the root into a leaf and break */
4680 btrfs_set_header_level(root
->node
, 0);
4681 } else if (slot
== 0) {
4682 struct btrfs_disk_key disk_key
;
4684 btrfs_node_key(parent
, &disk_key
, 0);
4685 fixup_low_keys(root
, path
, &disk_key
, level
+ 1);
4687 btrfs_mark_buffer_dirty(parent
);
4691 * a helper function to delete the leaf pointed to by path->slots[1] and
4694 * This deletes the pointer in path->nodes[1] and frees the leaf
4695 * block extent. zero is returned if it all worked out, < 0 otherwise.
4697 * The path must have already been setup for deleting the leaf, including
4698 * all the proper balancing. path->nodes[1] must be locked.
4700 static noinline
void btrfs_del_leaf(struct btrfs_trans_handle
*trans
,
4701 struct btrfs_root
*root
,
4702 struct btrfs_path
*path
,
4703 struct extent_buffer
*leaf
)
4705 WARN_ON(btrfs_header_generation(leaf
) != trans
->transid
);
4706 del_ptr(root
, path
, 1, path
->slots
[1]);
4709 * btrfs_free_extent is expensive, we want to make sure we
4710 * aren't holding any locks when we call it
4712 btrfs_unlock_up_safe(path
, 0);
4714 root_sub_used(root
, leaf
->len
);
4716 extent_buffer_get(leaf
);
4717 btrfs_free_tree_block(trans
, root
, leaf
, 0, 1);
4718 free_extent_buffer_stale(leaf
);
4721 * delete the item at the leaf level in path. If that empties
4722 * the leaf, remove it from the tree
4724 int btrfs_del_items(struct btrfs_trans_handle
*trans
, struct btrfs_root
*root
,
4725 struct btrfs_path
*path
, int slot
, int nr
)
4727 struct extent_buffer
*leaf
;
4728 struct btrfs_item
*item
;
4735 struct btrfs_map_token token
;
4737 btrfs_init_map_token(&token
);
4739 leaf
= path
->nodes
[0];
4740 last_off
= btrfs_item_offset_nr(leaf
, slot
+ nr
- 1);
4742 for (i
= 0; i
< nr
; i
++)
4743 dsize
+= btrfs_item_size_nr(leaf
, slot
+ i
);
4745 nritems
= btrfs_header_nritems(leaf
);
4747 if (slot
+ nr
!= nritems
) {
4748 int data_end
= leaf_data_end(root
, leaf
);
4750 memmove_extent_buffer(leaf
, btrfs_leaf_data(leaf
) +
4752 btrfs_leaf_data(leaf
) + data_end
,
4753 last_off
- data_end
);
4755 for (i
= slot
+ nr
; i
< nritems
; i
++) {
4758 item
= btrfs_item_nr(leaf
, i
);
4759 ioff
= btrfs_token_item_offset(leaf
, item
, &token
);
4760 btrfs_set_token_item_offset(leaf
, item
,
4761 ioff
+ dsize
, &token
);
4764 memmove_extent_buffer(leaf
, btrfs_item_nr_offset(slot
),
4765 btrfs_item_nr_offset(slot
+ nr
),
4766 sizeof(struct btrfs_item
) *
4767 (nritems
- slot
- nr
));
4769 btrfs_set_header_nritems(leaf
, nritems
- nr
);
4772 /* delete the leaf if we've emptied it */
4774 if (leaf
== root
->node
) {
4775 btrfs_set_header_level(leaf
, 0);
4777 btrfs_set_path_blocking(path
);
4778 clean_tree_block(trans
, root
, leaf
);
4779 btrfs_del_leaf(trans
, root
, path
, leaf
);
4782 int used
= leaf_space_used(leaf
, 0, nritems
);
4784 struct btrfs_disk_key disk_key
;
4786 btrfs_item_key(leaf
, &disk_key
, 0);
4787 fixup_low_keys(root
, path
, &disk_key
, 1);
4790 /* delete the leaf if it is mostly empty */
4791 if (used
< BTRFS_LEAF_DATA_SIZE(root
) / 3) {
4792 /* push_leaf_left fixes the path.
4793 * make sure the path still points to our leaf
4794 * for possible call to del_ptr below
4796 slot
= path
->slots
[1];
4797 extent_buffer_get(leaf
);
4799 btrfs_set_path_blocking(path
);
4800 wret
= push_leaf_left(trans
, root
, path
, 1, 1,
4802 if (wret
< 0 && wret
!= -ENOSPC
)
4805 if (path
->nodes
[0] == leaf
&&
4806 btrfs_header_nritems(leaf
)) {
4807 wret
= push_leaf_right(trans
, root
, path
, 1,
4809 if (wret
< 0 && wret
!= -ENOSPC
)
4813 if (btrfs_header_nritems(leaf
) == 0) {
4814 path
->slots
[1] = slot
;
4815 btrfs_del_leaf(trans
, root
, path
, leaf
);
4816 free_extent_buffer(leaf
);
4819 /* if we're still in the path, make sure
4820 * we're dirty. Otherwise, one of the
4821 * push_leaf functions must have already
4822 * dirtied this buffer
4824 if (path
->nodes
[0] == leaf
)
4825 btrfs_mark_buffer_dirty(leaf
);
4826 free_extent_buffer(leaf
);
4829 btrfs_mark_buffer_dirty(leaf
);
4836 * search the tree again to find a leaf with lesser keys
4837 * returns 0 if it found something or 1 if there are no lesser leaves.
4838 * returns < 0 on io errors.
4840 * This may release the path, and so you may lose any locks held at the
4843 int btrfs_prev_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
4845 struct btrfs_key key
;
4846 struct btrfs_disk_key found_key
;
4849 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, 0);
4853 else if (key
.type
> 0)
4855 else if (key
.objectid
> 0)
4860 btrfs_release_path(path
);
4861 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
4864 btrfs_item_key(path
->nodes
[0], &found_key
, 0);
4865 ret
= comp_keys(&found_key
, &key
);
4872 * A helper function to walk down the tree starting at min_key, and looking
4873 * for nodes or leaves that are have a minimum transaction id.
4874 * This is used by the btree defrag code, and tree logging
4876 * This does not cow, but it does stuff the starting key it finds back
4877 * into min_key, so you can call btrfs_search_slot with cow=1 on the
4878 * key and get a writable path.
4880 * This does lock as it descends, and path->keep_locks should be set
4881 * to 1 by the caller.
4883 * This honors path->lowest_level to prevent descent past a given level
4886 * min_trans indicates the oldest transaction that you are interested
4887 * in walking through. Any nodes or leaves older than min_trans are
4888 * skipped over (without reading them).
4890 * returns zero if something useful was found, < 0 on error and 1 if there
4891 * was nothing in the tree that matched the search criteria.
4893 int btrfs_search_forward(struct btrfs_root
*root
, struct btrfs_key
*min_key
,
4894 struct btrfs_key
*max_key
,
4895 struct btrfs_path
*path
,
4898 struct extent_buffer
*cur
;
4899 struct btrfs_key found_key
;
4906 WARN_ON(!path
->keep_locks
);
4908 cur
= btrfs_read_lock_root_node(root
);
4909 level
= btrfs_header_level(cur
);
4910 WARN_ON(path
->nodes
[level
]);
4911 path
->nodes
[level
] = cur
;
4912 path
->locks
[level
] = BTRFS_READ_LOCK
;
4914 if (btrfs_header_generation(cur
) < min_trans
) {
4919 nritems
= btrfs_header_nritems(cur
);
4920 level
= btrfs_header_level(cur
);
4921 sret
= bin_search(cur
, min_key
, level
, &slot
);
4923 /* at the lowest level, we're done, setup the path and exit */
4924 if (level
== path
->lowest_level
) {
4925 if (slot
>= nritems
)
4928 path
->slots
[level
] = slot
;
4929 btrfs_item_key_to_cpu(cur
, &found_key
, slot
);
4932 if (sret
&& slot
> 0)
4935 * check this node pointer against the min_trans parameters.
4936 * If it is too old, old, skip to the next one.
4938 while (slot
< nritems
) {
4942 blockptr
= btrfs_node_blockptr(cur
, slot
);
4943 gen
= btrfs_node_ptr_generation(cur
, slot
);
4944 if (gen
< min_trans
) {
4952 * we didn't find a candidate key in this node, walk forward
4953 * and find another one
4955 if (slot
>= nritems
) {
4956 path
->slots
[level
] = slot
;
4957 btrfs_set_path_blocking(path
);
4958 sret
= btrfs_find_next_key(root
, path
, min_key
, level
,
4961 btrfs_release_path(path
);
4967 /* save our key for returning back */
4968 btrfs_node_key_to_cpu(cur
, &found_key
, slot
);
4969 path
->slots
[level
] = slot
;
4970 if (level
== path
->lowest_level
) {
4972 unlock_up(path
, level
, 1, 0, NULL
);
4975 btrfs_set_path_blocking(path
);
4976 cur
= read_node_slot(root
, cur
, slot
);
4977 BUG_ON(!cur
); /* -ENOMEM */
4979 btrfs_tree_read_lock(cur
);
4981 path
->locks
[level
- 1] = BTRFS_READ_LOCK
;
4982 path
->nodes
[level
- 1] = cur
;
4983 unlock_up(path
, level
, 1, 0, NULL
);
4984 btrfs_clear_path_blocking(path
, NULL
, 0);
4988 memcpy(min_key
, &found_key
, sizeof(found_key
));
4989 btrfs_set_path_blocking(path
);
4993 static void tree_move_down(struct btrfs_root
*root
,
4994 struct btrfs_path
*path
,
4995 int *level
, int root_level
)
4997 BUG_ON(*level
== 0);
4998 path
->nodes
[*level
- 1] = read_node_slot(root
, path
->nodes
[*level
],
4999 path
->slots
[*level
]);
5000 path
->slots
[*level
- 1] = 0;
5004 static int tree_move_next_or_upnext(struct btrfs_root
*root
,
5005 struct btrfs_path
*path
,
5006 int *level
, int root_level
)
5010 nritems
= btrfs_header_nritems(path
->nodes
[*level
]);
5012 path
->slots
[*level
]++;
5014 while (path
->slots
[*level
] >= nritems
) {
5015 if (*level
== root_level
)
5019 path
->slots
[*level
] = 0;
5020 free_extent_buffer(path
->nodes
[*level
]);
5021 path
->nodes
[*level
] = NULL
;
5023 path
->slots
[*level
]++;
5025 nritems
= btrfs_header_nritems(path
->nodes
[*level
]);
5032 * Returns 1 if it had to move up and next. 0 is returned if it moved only next
5035 static int tree_advance(struct btrfs_root
*root
,
5036 struct btrfs_path
*path
,
5037 int *level
, int root_level
,
5039 struct btrfs_key
*key
)
5043 if (*level
== 0 || !allow_down
) {
5044 ret
= tree_move_next_or_upnext(root
, path
, level
, root_level
);
5046 tree_move_down(root
, path
, level
, root_level
);
5051 btrfs_item_key_to_cpu(path
->nodes
[*level
], key
,
5052 path
->slots
[*level
]);
5054 btrfs_node_key_to_cpu(path
->nodes
[*level
], key
,
5055 path
->slots
[*level
]);
5060 static int tree_compare_item(struct btrfs_root
*left_root
,
5061 struct btrfs_path
*left_path
,
5062 struct btrfs_path
*right_path
,
5067 unsigned long off1
, off2
;
5069 len1
= btrfs_item_size_nr(left_path
->nodes
[0], left_path
->slots
[0]);
5070 len2
= btrfs_item_size_nr(right_path
->nodes
[0], right_path
->slots
[0]);
5074 off1
= btrfs_item_ptr_offset(left_path
->nodes
[0], left_path
->slots
[0]);
5075 off2
= btrfs_item_ptr_offset(right_path
->nodes
[0],
5076 right_path
->slots
[0]);
5078 read_extent_buffer(left_path
->nodes
[0], tmp_buf
, off1
, len1
);
5080 cmp
= memcmp_extent_buffer(right_path
->nodes
[0], tmp_buf
, off2
, len1
);
5087 #define ADVANCE_ONLY_NEXT -1
5090 * This function compares two trees and calls the provided callback for
5091 * every changed/new/deleted item it finds.
5092 * If shared tree blocks are encountered, whole subtrees are skipped, making
5093 * the compare pretty fast on snapshotted subvolumes.
5095 * This currently works on commit roots only. As commit roots are read only,
5096 * we don't do any locking. The commit roots are protected with transactions.
5097 * Transactions are ended and rejoined when a commit is tried in between.
5099 * This function checks for modifications done to the trees while comparing.
5100 * If it detects a change, it aborts immediately.
5102 int btrfs_compare_trees(struct btrfs_root
*left_root
,
5103 struct btrfs_root
*right_root
,
5104 btrfs_changed_cb_t changed_cb
, void *ctx
)
5108 struct btrfs_trans_handle
*trans
= NULL
;
5109 struct btrfs_path
*left_path
= NULL
;
5110 struct btrfs_path
*right_path
= NULL
;
5111 struct btrfs_key left_key
;
5112 struct btrfs_key right_key
;
5113 char *tmp_buf
= NULL
;
5114 int left_root_level
;
5115 int right_root_level
;
5118 int left_end_reached
;
5119 int right_end_reached
;
5124 u64 left_start_ctransid
;
5125 u64 right_start_ctransid
;
5128 left_path
= btrfs_alloc_path();
5133 right_path
= btrfs_alloc_path();
5139 tmp_buf
= kmalloc(left_root
->leafsize
, GFP_NOFS
);
5145 left_path
->search_commit_root
= 1;
5146 left_path
->skip_locking
= 1;
5147 right_path
->search_commit_root
= 1;
5148 right_path
->skip_locking
= 1;
5150 spin_lock(&left_root
->root_item_lock
);
5151 left_start_ctransid
= btrfs_root_ctransid(&left_root
->root_item
);
5152 spin_unlock(&left_root
->root_item_lock
);
5154 spin_lock(&right_root
->root_item_lock
);
5155 right_start_ctransid
= btrfs_root_ctransid(&right_root
->root_item
);
5156 spin_unlock(&right_root
->root_item_lock
);
5158 trans
= btrfs_join_transaction(left_root
);
5159 if (IS_ERR(trans
)) {
5160 ret
= PTR_ERR(trans
);
5166 * Strategy: Go to the first items of both trees. Then do
5168 * If both trees are at level 0
5169 * Compare keys of current items
5170 * If left < right treat left item as new, advance left tree
5172 * If left > right treat right item as deleted, advance right tree
5174 * If left == right do deep compare of items, treat as changed if
5175 * needed, advance both trees and repeat
5176 * If both trees are at the same level but not at level 0
5177 * Compare keys of current nodes/leafs
5178 * If left < right advance left tree and repeat
5179 * If left > right advance right tree and repeat
5180 * If left == right compare blockptrs of the next nodes/leafs
5181 * If they match advance both trees but stay at the same level
5183 * If they don't match advance both trees while allowing to go
5185 * If tree levels are different
5186 * Advance the tree that needs it and repeat
5188 * Advancing a tree means:
5189 * If we are at level 0, try to go to the next slot. If that's not
5190 * possible, go one level up and repeat. Stop when we found a level
5191 * where we could go to the next slot. We may at this point be on a
5194 * If we are not at level 0 and not on shared tree blocks, go one
5197 * If we are not at level 0 and on shared tree blocks, go one slot to
5198 * the right if possible or go up and right.
5201 left_level
= btrfs_header_level(left_root
->commit_root
);
5202 left_root_level
= left_level
;
5203 left_path
->nodes
[left_level
] = left_root
->commit_root
;
5204 extent_buffer_get(left_path
->nodes
[left_level
]);
5206 right_level
= btrfs_header_level(right_root
->commit_root
);
5207 right_root_level
= right_level
;
5208 right_path
->nodes
[right_level
] = right_root
->commit_root
;
5209 extent_buffer_get(right_path
->nodes
[right_level
]);
5211 if (left_level
== 0)
5212 btrfs_item_key_to_cpu(left_path
->nodes
[left_level
],
5213 &left_key
, left_path
->slots
[left_level
]);
5215 btrfs_node_key_to_cpu(left_path
->nodes
[left_level
],
5216 &left_key
, left_path
->slots
[left_level
]);
5217 if (right_level
== 0)
5218 btrfs_item_key_to_cpu(right_path
->nodes
[right_level
],
5219 &right_key
, right_path
->slots
[right_level
]);
5221 btrfs_node_key_to_cpu(right_path
->nodes
[right_level
],
5222 &right_key
, right_path
->slots
[right_level
]);
5224 left_end_reached
= right_end_reached
= 0;
5225 advance_left
= advance_right
= 0;
5229 * We need to make sure the transaction does not get committed
5230 * while we do anything on commit roots. This means, we need to
5231 * join and leave transactions for every item that we process.
5233 if (trans
&& btrfs_should_end_transaction(trans
, left_root
)) {
5234 btrfs_release_path(left_path
);
5235 btrfs_release_path(right_path
);
5237 ret
= btrfs_end_transaction(trans
, left_root
);
5242 /* now rejoin the transaction */
5244 trans
= btrfs_join_transaction(left_root
);
5245 if (IS_ERR(trans
)) {
5246 ret
= PTR_ERR(trans
);
5251 spin_lock(&left_root
->root_item_lock
);
5252 ctransid
= btrfs_root_ctransid(&left_root
->root_item
);
5253 spin_unlock(&left_root
->root_item_lock
);
5254 if (ctransid
!= left_start_ctransid
)
5255 left_start_ctransid
= 0;
5257 spin_lock(&right_root
->root_item_lock
);
5258 ctransid
= btrfs_root_ctransid(&right_root
->root_item
);
5259 spin_unlock(&right_root
->root_item_lock
);
5260 if (ctransid
!= right_start_ctransid
)
5261 right_start_ctransid
= 0;
5263 if (!left_start_ctransid
|| !right_start_ctransid
) {
5264 WARN(1, KERN_WARNING
5265 "btrfs: btrfs_compare_tree detected "
5266 "a change in one of the trees while "
5267 "iterating. This is probably a "
5274 * the commit root may have changed, so start again
5277 left_path
->lowest_level
= left_level
;
5278 right_path
->lowest_level
= right_level
;
5279 ret
= btrfs_search_slot(NULL
, left_root
,
5280 &left_key
, left_path
, 0, 0);
5283 ret
= btrfs_search_slot(NULL
, right_root
,
5284 &right_key
, right_path
, 0, 0);
5289 if (advance_left
&& !left_end_reached
) {
5290 ret
= tree_advance(left_root
, left_path
, &left_level
,
5292 advance_left
!= ADVANCE_ONLY_NEXT
,
5295 left_end_reached
= ADVANCE
;
5298 if (advance_right
&& !right_end_reached
) {
5299 ret
= tree_advance(right_root
, right_path
, &right_level
,
5301 advance_right
!= ADVANCE_ONLY_NEXT
,
5304 right_end_reached
= ADVANCE
;
5308 if (left_end_reached
&& right_end_reached
) {
5311 } else if (left_end_reached
) {
5312 if (right_level
== 0) {
5313 ret
= changed_cb(left_root
, right_root
,
5314 left_path
, right_path
,
5316 BTRFS_COMPARE_TREE_DELETED
,
5321 advance_right
= ADVANCE
;
5323 } else if (right_end_reached
) {
5324 if (left_level
== 0) {
5325 ret
= changed_cb(left_root
, right_root
,
5326 left_path
, right_path
,
5328 BTRFS_COMPARE_TREE_NEW
,
5333 advance_left
= ADVANCE
;
5337 if (left_level
== 0 && right_level
== 0) {
5338 cmp
= btrfs_comp_cpu_keys(&left_key
, &right_key
);
5340 ret
= changed_cb(left_root
, right_root
,
5341 left_path
, right_path
,
5343 BTRFS_COMPARE_TREE_NEW
,
5347 advance_left
= ADVANCE
;
5348 } else if (cmp
> 0) {
5349 ret
= changed_cb(left_root
, right_root
,
5350 left_path
, right_path
,
5352 BTRFS_COMPARE_TREE_DELETED
,
5356 advance_right
= ADVANCE
;
5358 WARN_ON(!extent_buffer_uptodate(left_path
->nodes
[0]));
5359 ret
= tree_compare_item(left_root
, left_path
,
5360 right_path
, tmp_buf
);
5362 WARN_ON(!extent_buffer_uptodate(left_path
->nodes
[0]));
5363 ret
= changed_cb(left_root
, right_root
,
5364 left_path
, right_path
,
5366 BTRFS_COMPARE_TREE_CHANGED
,
5371 advance_left
= ADVANCE
;
5372 advance_right
= ADVANCE
;
5374 } else if (left_level
== right_level
) {
5375 cmp
= btrfs_comp_cpu_keys(&left_key
, &right_key
);
5377 advance_left
= ADVANCE
;
5378 } else if (cmp
> 0) {
5379 advance_right
= ADVANCE
;
5381 left_blockptr
= btrfs_node_blockptr(
5382 left_path
->nodes
[left_level
],
5383 left_path
->slots
[left_level
]);
5384 right_blockptr
= btrfs_node_blockptr(
5385 right_path
->nodes
[right_level
],
5386 right_path
->slots
[right_level
]);
5387 if (left_blockptr
== right_blockptr
) {
5389 * As we're on a shared block, don't
5390 * allow to go deeper.
5392 advance_left
= ADVANCE_ONLY_NEXT
;
5393 advance_right
= ADVANCE_ONLY_NEXT
;
5395 advance_left
= ADVANCE
;
5396 advance_right
= ADVANCE
;
5399 } else if (left_level
< right_level
) {
5400 advance_right
= ADVANCE
;
5402 advance_left
= ADVANCE
;
5407 btrfs_free_path(left_path
);
5408 btrfs_free_path(right_path
);
5413 ret
= btrfs_end_transaction(trans
, left_root
);
5415 btrfs_end_transaction(trans
, left_root
);
5422 * this is similar to btrfs_next_leaf, but does not try to preserve
5423 * and fixup the path. It looks for and returns the next key in the
5424 * tree based on the current path and the min_trans parameters.
5426 * 0 is returned if another key is found, < 0 if there are any errors
5427 * and 1 is returned if there are no higher keys in the tree
5429 * path->keep_locks should be set to 1 on the search made before
5430 * calling this function.
5432 int btrfs_find_next_key(struct btrfs_root
*root
, struct btrfs_path
*path
,
5433 struct btrfs_key
*key
, int level
, u64 min_trans
)
5436 struct extent_buffer
*c
;
5438 WARN_ON(!path
->keep_locks
);
5439 while (level
< BTRFS_MAX_LEVEL
) {
5440 if (!path
->nodes
[level
])
5443 slot
= path
->slots
[level
] + 1;
5444 c
= path
->nodes
[level
];
5446 if (slot
>= btrfs_header_nritems(c
)) {
5449 struct btrfs_key cur_key
;
5450 if (level
+ 1 >= BTRFS_MAX_LEVEL
||
5451 !path
->nodes
[level
+ 1])
5454 if (path
->locks
[level
+ 1]) {
5459 slot
= btrfs_header_nritems(c
) - 1;
5461 btrfs_item_key_to_cpu(c
, &cur_key
, slot
);
5463 btrfs_node_key_to_cpu(c
, &cur_key
, slot
);
5465 orig_lowest
= path
->lowest_level
;
5466 btrfs_release_path(path
);
5467 path
->lowest_level
= level
;
5468 ret
= btrfs_search_slot(NULL
, root
, &cur_key
, path
,
5470 path
->lowest_level
= orig_lowest
;
5474 c
= path
->nodes
[level
];
5475 slot
= path
->slots
[level
];
5482 btrfs_item_key_to_cpu(c
, key
, slot
);
5484 u64 gen
= btrfs_node_ptr_generation(c
, slot
);
5486 if (gen
< min_trans
) {
5490 btrfs_node_key_to_cpu(c
, key
, slot
);
5498 * search the tree again to find a leaf with greater keys
5499 * returns 0 if it found something or 1 if there are no greater leaves.
5500 * returns < 0 on io errors.
5502 int btrfs_next_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
)
5504 return btrfs_next_old_leaf(root
, path
, 0);
5507 int btrfs_next_old_leaf(struct btrfs_root
*root
, struct btrfs_path
*path
,
5512 struct extent_buffer
*c
;
5513 struct extent_buffer
*next
;
5514 struct btrfs_key key
;
5517 int old_spinning
= path
->leave_spinning
;
5518 int next_rw_lock
= 0;
5520 nritems
= btrfs_header_nritems(path
->nodes
[0]);
5524 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, nritems
- 1);
5529 btrfs_release_path(path
);
5531 path
->keep_locks
= 1;
5532 path
->leave_spinning
= 1;
5535 ret
= btrfs_search_old_slot(root
, &key
, path
, time_seq
);
5537 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
5538 path
->keep_locks
= 0;
5543 nritems
= btrfs_header_nritems(path
->nodes
[0]);
5545 * by releasing the path above we dropped all our locks. A balance
5546 * could have added more items next to the key that used to be
5547 * at the very end of the block. So, check again here and
5548 * advance the path if there are now more items available.
5550 if (nritems
> 0 && path
->slots
[0] < nritems
- 1) {
5557 while (level
< BTRFS_MAX_LEVEL
) {
5558 if (!path
->nodes
[level
]) {
5563 slot
= path
->slots
[level
] + 1;
5564 c
= path
->nodes
[level
];
5565 if (slot
>= btrfs_header_nritems(c
)) {
5567 if (level
== BTRFS_MAX_LEVEL
) {
5575 btrfs_tree_unlock_rw(next
, next_rw_lock
);
5576 free_extent_buffer(next
);
5580 next_rw_lock
= path
->locks
[level
];
5581 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
5587 btrfs_release_path(path
);
5591 if (!path
->skip_locking
) {
5592 ret
= btrfs_try_tree_read_lock(next
);
5593 if (!ret
&& time_seq
) {
5595 * If we don't get the lock, we may be racing
5596 * with push_leaf_left, holding that lock while
5597 * itself waiting for the leaf we've currently
5598 * locked. To solve this situation, we give up
5599 * on our lock and cycle.
5601 free_extent_buffer(next
);
5602 btrfs_release_path(path
);
5607 btrfs_set_path_blocking(path
);
5608 btrfs_tree_read_lock(next
);
5609 btrfs_clear_path_blocking(path
, next
,
5612 next_rw_lock
= BTRFS_READ_LOCK
;
5616 path
->slots
[level
] = slot
;
5619 c
= path
->nodes
[level
];
5620 if (path
->locks
[level
])
5621 btrfs_tree_unlock_rw(c
, path
->locks
[level
]);
5623 free_extent_buffer(c
);
5624 path
->nodes
[level
] = next
;
5625 path
->slots
[level
] = 0;
5626 if (!path
->skip_locking
)
5627 path
->locks
[level
] = next_rw_lock
;
5631 ret
= read_block_for_search(NULL
, root
, path
, &next
, level
,
5637 btrfs_release_path(path
);
5641 if (!path
->skip_locking
) {
5642 ret
= btrfs_try_tree_read_lock(next
);
5644 btrfs_set_path_blocking(path
);
5645 btrfs_tree_read_lock(next
);
5646 btrfs_clear_path_blocking(path
, next
,
5649 next_rw_lock
= BTRFS_READ_LOCK
;
5654 unlock_up(path
, 0, 1, 0, NULL
);
5655 path
->leave_spinning
= old_spinning
;
5657 btrfs_set_path_blocking(path
);
5663 * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps
5664 * searching until it gets past min_objectid or finds an item of 'type'
5666 * returns 0 if something is found, 1 if nothing was found and < 0 on error
5668 int btrfs_previous_item(struct btrfs_root
*root
,
5669 struct btrfs_path
*path
, u64 min_objectid
,
5672 struct btrfs_key found_key
;
5673 struct extent_buffer
*leaf
;
5678 if (path
->slots
[0] == 0) {
5679 btrfs_set_path_blocking(path
);
5680 ret
= btrfs_prev_leaf(root
, path
);
5686 leaf
= path
->nodes
[0];
5687 nritems
= btrfs_header_nritems(leaf
);
5690 if (path
->slots
[0] == nritems
)
5693 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
5694 if (found_key
.objectid
< min_objectid
)
5696 if (found_key
.type
== type
)
5698 if (found_key
.objectid
== min_objectid
&&
5699 found_key
.type
< type
)