2 * Copyright (C) 2011 STRATO. 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.
23 #include "transaction.h"
24 #include "delayed-ref.h"
27 struct extent_inode_elem
{
30 struct extent_inode_elem
*next
;
33 static int check_extent_in_eb(struct btrfs_key
*key
, struct extent_buffer
*eb
,
34 struct btrfs_file_extent_item
*fi
,
36 struct extent_inode_elem
**eie
)
40 struct extent_inode_elem
*e
;
42 data_offset
= btrfs_file_extent_offset(eb
, fi
);
43 data_len
= btrfs_file_extent_num_bytes(eb
, fi
);
45 if (extent_item_pos
< data_offset
||
46 extent_item_pos
>= data_offset
+ data_len
)
49 e
= kmalloc(sizeof(*e
), GFP_NOFS
);
54 e
->inum
= key
->objectid
;
55 e
->offset
= key
->offset
+ (extent_item_pos
- data_offset
);
61 static int find_extent_in_eb(struct extent_buffer
*eb
, u64 wanted_disk_byte
,
63 struct extent_inode_elem
**eie
)
67 struct btrfs_file_extent_item
*fi
;
74 * from the shared data ref, we only have the leaf but we need
75 * the key. thus, we must look into all items and see that we
76 * find one (some) with a reference to our extent item.
78 nritems
= btrfs_header_nritems(eb
);
79 for (slot
= 0; slot
< nritems
; ++slot
) {
80 btrfs_item_key_to_cpu(eb
, &key
, slot
);
81 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
83 fi
= btrfs_item_ptr(eb
, slot
, struct btrfs_file_extent_item
);
84 extent_type
= btrfs_file_extent_type(eb
, fi
);
85 if (extent_type
== BTRFS_FILE_EXTENT_INLINE
)
87 /* don't skip BTRFS_FILE_EXTENT_PREALLOC, we can handle that */
88 disk_byte
= btrfs_file_extent_disk_bytenr(eb
, fi
);
89 if (disk_byte
!= wanted_disk_byte
)
92 ret
= check_extent_in_eb(&key
, eb
, fi
, extent_item_pos
, eie
);
101 * this structure records all encountered refs on the way up to the root
103 struct __prelim_ref
{
104 struct list_head list
;
106 struct btrfs_key key_for_search
;
109 struct extent_inode_elem
*inode_list
;
111 u64 wanted_disk_byte
;
115 * the rules for all callers of this function are:
116 * - obtaining the parent is the goal
117 * - if you add a key, you must know that it is a correct key
118 * - if you cannot add the parent or a correct key, then we will look into the
119 * block later to set a correct key
123 * backref type | shared | indirect | shared | indirect
124 * information | tree | tree | data | data
125 * --------------------+--------+----------+--------+----------
126 * parent logical | y | - | - | -
127 * key to resolve | - | y | y | y
128 * tree block logical | - | - | - | -
129 * root for resolving | y | y | y | y
131 * - column 1: we've the parent -> done
132 * - column 2, 3, 4: we use the key to find the parent
134 * on disk refs (inline or keyed)
135 * ==============================
136 * backref type | shared | indirect | shared | indirect
137 * information | tree | tree | data | data
138 * --------------------+--------+----------+--------+----------
139 * parent logical | y | - | y | -
140 * key to resolve | - | - | - | y
141 * tree block logical | y | y | y | y
142 * root for resolving | - | y | y | y
144 * - column 1, 3: we've the parent -> done
145 * - column 2: we take the first key from the block to find the parent
146 * (see __add_missing_keys)
147 * - column 4: we use the key to find the parent
149 * additional information that's available but not required to find the parent
150 * block might help in merging entries to gain some speed.
153 static int __add_prelim_ref(struct list_head
*head
, u64 root_id
,
154 struct btrfs_key
*key
, int level
,
155 u64 parent
, u64 wanted_disk_byte
, int count
)
157 struct __prelim_ref
*ref
;
159 /* in case we're adding delayed refs, we're holding the refs spinlock */
160 ref
= kmalloc(sizeof(*ref
), GFP_ATOMIC
);
164 ref
->root_id
= root_id
;
166 ref
->key_for_search
= *key
;
168 memset(&ref
->key_for_search
, 0, sizeof(ref
->key_for_search
));
170 ref
->inode_list
= NULL
;
173 ref
->parent
= parent
;
174 ref
->wanted_disk_byte
= wanted_disk_byte
;
175 list_add_tail(&ref
->list
, head
);
180 static int add_all_parents(struct btrfs_root
*root
, struct btrfs_path
*path
,
181 struct ulist
*parents
, int level
,
182 struct btrfs_key
*key
, u64 wanted_disk_byte
,
183 const u64
*extent_item_pos
)
186 int slot
= path
->slots
[level
];
187 struct extent_buffer
*eb
= path
->nodes
[level
];
188 struct btrfs_file_extent_item
*fi
;
189 struct extent_inode_elem
*eie
= NULL
;
191 u64 wanted_objectid
= key
->objectid
;
194 if (level
== 0 && extent_item_pos
) {
195 fi
= btrfs_item_ptr(eb
, slot
, struct btrfs_file_extent_item
);
196 ret
= check_extent_in_eb(key
, eb
, fi
, *extent_item_pos
, &eie
);
200 ret
= ulist_add(parents
, eb
->start
, (unsigned long)eie
, GFP_NOFS
);
208 * if the current leaf is full with EXTENT_DATA items, we must
209 * check the next one if that holds a reference as well.
210 * ref->count cannot be used to skip this check.
211 * repeat this until we don't find any additional EXTENT_DATA items.
215 ret
= btrfs_next_leaf(root
, path
);
222 for (slot
= 0; slot
< btrfs_header_nritems(eb
); ++slot
) {
223 btrfs_item_key_to_cpu(eb
, key
, slot
);
224 if (key
->objectid
!= wanted_objectid
||
225 key
->type
!= BTRFS_EXTENT_DATA_KEY
)
227 fi
= btrfs_item_ptr(eb
, slot
,
228 struct btrfs_file_extent_item
);
229 disk_byte
= btrfs_file_extent_disk_bytenr(eb
, fi
);
230 if (disk_byte
== wanted_disk_byte
)
239 * resolve an indirect backref in the form (root_id, key, level)
240 * to a logical address
242 static int __resolve_indirect_ref(struct btrfs_fs_info
*fs_info
,
243 int search_commit_root
,
245 struct __prelim_ref
*ref
,
246 struct ulist
*parents
,
247 const u64
*extent_item_pos
)
249 struct btrfs_path
*path
;
250 struct btrfs_root
*root
;
251 struct btrfs_key root_key
;
252 struct btrfs_key key
= {0};
253 struct extent_buffer
*eb
;
256 int level
= ref
->level
;
258 path
= btrfs_alloc_path();
261 path
->search_commit_root
= !!search_commit_root
;
263 root_key
.objectid
= ref
->root_id
;
264 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
265 root_key
.offset
= (u64
)-1;
266 root
= btrfs_read_fs_root_no_name(fs_info
, &root_key
);
273 root_level
= btrfs_header_level(root
->node
);
276 if (root_level
+ 1 == level
)
279 path
->lowest_level
= level
;
280 ret
= btrfs_search_old_slot(root
, &ref
->key_for_search
, path
, time_seq
);
281 pr_debug("search slot in root %llu (level %d, ref count %d) returned "
282 "%d for key (%llu %u %llu)\n",
283 (unsigned long long)ref
->root_id
, level
, ref
->count
, ret
,
284 (unsigned long long)ref
->key_for_search
.objectid
,
285 ref
->key_for_search
.type
,
286 (unsigned long long)ref
->key_for_search
.offset
);
290 eb
= path
->nodes
[level
];
298 if (ret
== 1 && path
->slots
[0] >= btrfs_header_nritems(eb
)) {
299 ret
= btrfs_next_leaf(root
, path
);
305 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
308 ret
= add_all_parents(root
, path
, parents
, level
, &key
,
309 ref
->wanted_disk_byte
, extent_item_pos
);
311 btrfs_free_path(path
);
316 * resolve all indirect backrefs from the list
318 static int __resolve_indirect_refs(struct btrfs_fs_info
*fs_info
,
319 int search_commit_root
, u64 time_seq
,
320 struct list_head
*head
,
321 const u64
*extent_item_pos
)
325 struct __prelim_ref
*ref
;
326 struct __prelim_ref
*ref_safe
;
327 struct __prelim_ref
*new_ref
;
328 struct ulist
*parents
;
329 struct ulist_node
*node
;
330 struct ulist_iterator uiter
;
332 parents
= ulist_alloc(GFP_NOFS
);
337 * _safe allows us to insert directly after the current item without
338 * iterating over the newly inserted items.
339 * we're also allowed to re-assign ref during iteration.
341 list_for_each_entry_safe(ref
, ref_safe
, head
, list
) {
342 if (ref
->parent
) /* already direct */
346 err
= __resolve_indirect_ref(fs_info
, search_commit_root
,
347 time_seq
, ref
, parents
,
355 /* we put the first parent into the ref at hand */
356 ULIST_ITER_INIT(&uiter
);
357 node
= ulist_next(parents
, &uiter
);
358 ref
->parent
= node
? node
->val
: 0;
360 node
? (struct extent_inode_elem
*)node
->aux
: 0;
362 /* additional parents require new refs being added here */
363 while ((node
= ulist_next(parents
, &uiter
))) {
364 new_ref
= kmalloc(sizeof(*new_ref
), GFP_NOFS
);
369 memcpy(new_ref
, ref
, sizeof(*ref
));
370 new_ref
->parent
= node
->val
;
371 new_ref
->inode_list
=
372 (struct extent_inode_elem
*)node
->aux
;
373 list_add(&new_ref
->list
, &ref
->list
);
375 ulist_reinit(parents
);
382 static inline int ref_for_same_block(struct __prelim_ref
*ref1
,
383 struct __prelim_ref
*ref2
)
385 if (ref1
->level
!= ref2
->level
)
387 if (ref1
->root_id
!= ref2
->root_id
)
389 if (ref1
->key_for_search
.type
!= ref2
->key_for_search
.type
)
391 if (ref1
->key_for_search
.objectid
!= ref2
->key_for_search
.objectid
)
393 if (ref1
->key_for_search
.offset
!= ref2
->key_for_search
.offset
)
395 if (ref1
->parent
!= ref2
->parent
)
402 * read tree blocks and add keys where required.
404 static int __add_missing_keys(struct btrfs_fs_info
*fs_info
,
405 struct list_head
*head
)
407 struct list_head
*pos
;
408 struct extent_buffer
*eb
;
410 list_for_each(pos
, head
) {
411 struct __prelim_ref
*ref
;
412 ref
= list_entry(pos
, struct __prelim_ref
, list
);
416 if (ref
->key_for_search
.type
)
418 BUG_ON(!ref
->wanted_disk_byte
);
419 eb
= read_tree_block(fs_info
->tree_root
, ref
->wanted_disk_byte
,
420 fs_info
->tree_root
->leafsize
, 0);
422 btrfs_tree_read_lock(eb
);
423 if (btrfs_header_level(eb
) == 0)
424 btrfs_item_key_to_cpu(eb
, &ref
->key_for_search
, 0);
426 btrfs_node_key_to_cpu(eb
, &ref
->key_for_search
, 0);
427 btrfs_tree_read_unlock(eb
);
428 free_extent_buffer(eb
);
434 * merge two lists of backrefs and adjust counts accordingly
436 * mode = 1: merge identical keys, if key is set
437 * FIXME: if we add more keys in __add_prelim_ref, we can merge more here.
438 * additionally, we could even add a key range for the blocks we
439 * looked into to merge even more (-> replace unresolved refs by those
441 * mode = 2: merge identical parents
443 static int __merge_refs(struct list_head
*head
, int mode
)
445 struct list_head
*pos1
;
447 list_for_each(pos1
, head
) {
448 struct list_head
*n2
;
449 struct list_head
*pos2
;
450 struct __prelim_ref
*ref1
;
452 ref1
= list_entry(pos1
, struct __prelim_ref
, list
);
454 for (pos2
= pos1
->next
, n2
= pos2
->next
; pos2
!= head
;
455 pos2
= n2
, n2
= pos2
->next
) {
456 struct __prelim_ref
*ref2
;
457 struct __prelim_ref
*xchg
;
459 ref2
= list_entry(pos2
, struct __prelim_ref
, list
);
462 if (!ref_for_same_block(ref1
, ref2
))
464 if (!ref1
->parent
&& ref2
->parent
) {
469 ref1
->count
+= ref2
->count
;
471 if (ref1
->parent
!= ref2
->parent
)
473 ref1
->count
+= ref2
->count
;
475 list_del(&ref2
->list
);
484 * add all currently queued delayed refs from this head whose seq nr is
485 * smaller or equal that seq to the list
487 static int __add_delayed_refs(struct btrfs_delayed_ref_head
*head
, u64 seq
,
488 struct list_head
*prefs
)
490 struct btrfs_delayed_extent_op
*extent_op
= head
->extent_op
;
491 struct rb_node
*n
= &head
->node
.rb_node
;
492 struct btrfs_key key
;
493 struct btrfs_key op_key
= {0};
497 if (extent_op
&& extent_op
->update_key
)
498 btrfs_disk_key_to_cpu(&op_key
, &extent_op
->key
);
500 while ((n
= rb_prev(n
))) {
501 struct btrfs_delayed_ref_node
*node
;
502 node
= rb_entry(n
, struct btrfs_delayed_ref_node
,
504 if (node
->bytenr
!= head
->node
.bytenr
)
506 WARN_ON(node
->is_head
);
511 switch (node
->action
) {
512 case BTRFS_ADD_DELAYED_EXTENT
:
513 case BTRFS_UPDATE_DELAYED_HEAD
:
516 case BTRFS_ADD_DELAYED_REF
:
519 case BTRFS_DROP_DELAYED_REF
:
525 switch (node
->type
) {
526 case BTRFS_TREE_BLOCK_REF_KEY
: {
527 struct btrfs_delayed_tree_ref
*ref
;
529 ref
= btrfs_delayed_node_to_tree_ref(node
);
530 ret
= __add_prelim_ref(prefs
, ref
->root
, &op_key
,
531 ref
->level
+ 1, 0, node
->bytenr
,
532 node
->ref_mod
* sgn
);
535 case BTRFS_SHARED_BLOCK_REF_KEY
: {
536 struct btrfs_delayed_tree_ref
*ref
;
538 ref
= btrfs_delayed_node_to_tree_ref(node
);
539 ret
= __add_prelim_ref(prefs
, ref
->root
, NULL
,
540 ref
->level
+ 1, ref
->parent
,
542 node
->ref_mod
* sgn
);
545 case BTRFS_EXTENT_DATA_REF_KEY
: {
546 struct btrfs_delayed_data_ref
*ref
;
547 ref
= btrfs_delayed_node_to_data_ref(node
);
549 key
.objectid
= ref
->objectid
;
550 key
.type
= BTRFS_EXTENT_DATA_KEY
;
551 key
.offset
= ref
->offset
;
552 ret
= __add_prelim_ref(prefs
, ref
->root
, &key
, 0, 0,
554 node
->ref_mod
* sgn
);
557 case BTRFS_SHARED_DATA_REF_KEY
: {
558 struct btrfs_delayed_data_ref
*ref
;
560 ref
= btrfs_delayed_node_to_data_ref(node
);
562 key
.objectid
= ref
->objectid
;
563 key
.type
= BTRFS_EXTENT_DATA_KEY
;
564 key
.offset
= ref
->offset
;
565 ret
= __add_prelim_ref(prefs
, ref
->root
, &key
, 0,
566 ref
->parent
, node
->bytenr
,
567 node
->ref_mod
* sgn
);
580 * add all inline backrefs for bytenr to the list
582 static int __add_inline_refs(struct btrfs_fs_info
*fs_info
,
583 struct btrfs_path
*path
, u64 bytenr
,
584 int *info_level
, struct list_head
*prefs
)
588 struct extent_buffer
*leaf
;
589 struct btrfs_key key
;
592 struct btrfs_extent_item
*ei
;
597 * enumerate all inline refs
599 leaf
= path
->nodes
[0];
600 slot
= path
->slots
[0];
602 item_size
= btrfs_item_size_nr(leaf
, slot
);
603 BUG_ON(item_size
< sizeof(*ei
));
605 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
606 flags
= btrfs_extent_flags(leaf
, ei
);
608 ptr
= (unsigned long)(ei
+ 1);
609 end
= (unsigned long)ei
+ item_size
;
611 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
612 struct btrfs_tree_block_info
*info
;
614 info
= (struct btrfs_tree_block_info
*)ptr
;
615 *info_level
= btrfs_tree_block_level(leaf
, info
);
616 ptr
+= sizeof(struct btrfs_tree_block_info
);
619 BUG_ON(!(flags
& BTRFS_EXTENT_FLAG_DATA
));
623 struct btrfs_extent_inline_ref
*iref
;
627 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
628 type
= btrfs_extent_inline_ref_type(leaf
, iref
);
629 offset
= btrfs_extent_inline_ref_offset(leaf
, iref
);
632 case BTRFS_SHARED_BLOCK_REF_KEY
:
633 ret
= __add_prelim_ref(prefs
, 0, NULL
,
634 *info_level
+ 1, offset
,
637 case BTRFS_SHARED_DATA_REF_KEY
: {
638 struct btrfs_shared_data_ref
*sdref
;
641 sdref
= (struct btrfs_shared_data_ref
*)(iref
+ 1);
642 count
= btrfs_shared_data_ref_count(leaf
, sdref
);
643 ret
= __add_prelim_ref(prefs
, 0, NULL
, 0, offset
,
647 case BTRFS_TREE_BLOCK_REF_KEY
:
648 ret
= __add_prelim_ref(prefs
, offset
, NULL
,
652 case BTRFS_EXTENT_DATA_REF_KEY
: {
653 struct btrfs_extent_data_ref
*dref
;
657 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
658 count
= btrfs_extent_data_ref_count(leaf
, dref
);
659 key
.objectid
= btrfs_extent_data_ref_objectid(leaf
,
661 key
.type
= BTRFS_EXTENT_DATA_KEY
;
662 key
.offset
= btrfs_extent_data_ref_offset(leaf
, dref
);
663 root
= btrfs_extent_data_ref_root(leaf
, dref
);
664 ret
= __add_prelim_ref(prefs
, root
, &key
, 0, 0,
672 ptr
+= btrfs_extent_inline_ref_size(type
);
679 * add all non-inline backrefs for bytenr to the list
681 static int __add_keyed_refs(struct btrfs_fs_info
*fs_info
,
682 struct btrfs_path
*path
, u64 bytenr
,
683 int info_level
, struct list_head
*prefs
)
685 struct btrfs_root
*extent_root
= fs_info
->extent_root
;
688 struct extent_buffer
*leaf
;
689 struct btrfs_key key
;
692 ret
= btrfs_next_item(extent_root
, path
);
700 slot
= path
->slots
[0];
701 leaf
= path
->nodes
[0];
702 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
704 if (key
.objectid
!= bytenr
)
706 if (key
.type
< BTRFS_TREE_BLOCK_REF_KEY
)
708 if (key
.type
> BTRFS_SHARED_DATA_REF_KEY
)
712 case BTRFS_SHARED_BLOCK_REF_KEY
:
713 ret
= __add_prelim_ref(prefs
, 0, NULL
,
714 info_level
+ 1, key
.offset
,
717 case BTRFS_SHARED_DATA_REF_KEY
: {
718 struct btrfs_shared_data_ref
*sdref
;
721 sdref
= btrfs_item_ptr(leaf
, slot
,
722 struct btrfs_shared_data_ref
);
723 count
= btrfs_shared_data_ref_count(leaf
, sdref
);
724 ret
= __add_prelim_ref(prefs
, 0, NULL
, 0, key
.offset
,
728 case BTRFS_TREE_BLOCK_REF_KEY
:
729 ret
= __add_prelim_ref(prefs
, key
.offset
, NULL
,
733 case BTRFS_EXTENT_DATA_REF_KEY
: {
734 struct btrfs_extent_data_ref
*dref
;
738 dref
= btrfs_item_ptr(leaf
, slot
,
739 struct btrfs_extent_data_ref
);
740 count
= btrfs_extent_data_ref_count(leaf
, dref
);
741 key
.objectid
= btrfs_extent_data_ref_objectid(leaf
,
743 key
.type
= BTRFS_EXTENT_DATA_KEY
;
744 key
.offset
= btrfs_extent_data_ref_offset(leaf
, dref
);
745 root
= btrfs_extent_data_ref_root(leaf
, dref
);
746 ret
= __add_prelim_ref(prefs
, root
, &key
, 0, 0,
760 * this adds all existing backrefs (inline backrefs, backrefs and delayed
761 * refs) for the given bytenr to the refs list, merges duplicates and resolves
762 * indirect refs to their parent bytenr.
763 * When roots are found, they're added to the roots list
765 * FIXME some caching might speed things up
767 static int find_parent_nodes(struct btrfs_trans_handle
*trans
,
768 struct btrfs_fs_info
*fs_info
, u64 bytenr
,
769 u64 delayed_ref_seq
, u64 time_seq
,
770 struct ulist
*refs
, struct ulist
*roots
,
771 const u64
*extent_item_pos
)
773 struct btrfs_key key
;
774 struct btrfs_path
*path
;
775 struct btrfs_delayed_ref_root
*delayed_refs
= NULL
;
776 struct btrfs_delayed_ref_head
*head
;
779 int search_commit_root
= (trans
== BTRFS_BACKREF_SEARCH_COMMIT_ROOT
);
780 struct list_head prefs_delayed
;
781 struct list_head prefs
;
782 struct __prelim_ref
*ref
;
784 INIT_LIST_HEAD(&prefs
);
785 INIT_LIST_HEAD(&prefs_delayed
);
787 key
.objectid
= bytenr
;
788 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
789 key
.offset
= (u64
)-1;
791 path
= btrfs_alloc_path();
794 path
->search_commit_root
= !!search_commit_root
;
797 * grab both a lock on the path and a lock on the delayed ref head.
798 * We need both to get a consistent picture of how the refs look
799 * at a specified point in time
804 ret
= btrfs_search_slot(trans
, fs_info
->extent_root
, &key
, path
, 0, 0);
809 if (trans
!= BTRFS_BACKREF_SEARCH_COMMIT_ROOT
) {
811 * look if there are updates for this ref queued and lock the
814 delayed_refs
= &trans
->transaction
->delayed_refs
;
815 spin_lock(&delayed_refs
->lock
);
816 head
= btrfs_find_delayed_ref_head(trans
, bytenr
);
818 if (!mutex_trylock(&head
->mutex
)) {
819 atomic_inc(&head
->node
.refs
);
820 spin_unlock(&delayed_refs
->lock
);
822 btrfs_release_path(path
);
825 * Mutex was contended, block until it's
826 * released and try again
828 mutex_lock(&head
->mutex
);
829 mutex_unlock(&head
->mutex
);
830 btrfs_put_delayed_ref(&head
->node
);
833 ret
= __add_delayed_refs(head
, delayed_ref_seq
,
836 spin_unlock(&delayed_refs
->lock
);
840 spin_unlock(&delayed_refs
->lock
);
843 if (path
->slots
[0]) {
844 struct extent_buffer
*leaf
;
848 leaf
= path
->nodes
[0];
849 slot
= path
->slots
[0];
850 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
851 if (key
.objectid
== bytenr
&&
852 key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
853 ret
= __add_inline_refs(fs_info
, path
, bytenr
,
854 &info_level
, &prefs
);
857 ret
= __add_keyed_refs(fs_info
, path
, bytenr
,
863 btrfs_release_path(path
);
865 list_splice_init(&prefs_delayed
, &prefs
);
867 ret
= __add_missing_keys(fs_info
, &prefs
);
871 ret
= __merge_refs(&prefs
, 1);
875 ret
= __resolve_indirect_refs(fs_info
, search_commit_root
, time_seq
,
876 &prefs
, extent_item_pos
);
880 ret
= __merge_refs(&prefs
, 2);
884 while (!list_empty(&prefs
)) {
885 ref
= list_first_entry(&prefs
, struct __prelim_ref
, list
);
886 list_del(&ref
->list
);
889 if (ref
->count
&& ref
->root_id
&& ref
->parent
== 0) {
890 /* no parent == root of tree */
891 ret
= ulist_add(roots
, ref
->root_id
, 0, GFP_NOFS
);
894 if (ref
->count
&& ref
->parent
) {
895 struct extent_inode_elem
*eie
= NULL
;
896 if (extent_item_pos
&& !ref
->inode_list
) {
898 struct extent_buffer
*eb
;
899 bsz
= btrfs_level_size(fs_info
->extent_root
,
901 eb
= read_tree_block(fs_info
->extent_root
,
902 ref
->parent
, bsz
, 0);
904 ret
= find_extent_in_eb(eb
, bytenr
,
905 *extent_item_pos
, &eie
);
906 ref
->inode_list
= eie
;
907 free_extent_buffer(eb
);
909 ret
= ulist_add_merge(refs
, ref
->parent
,
910 (unsigned long)ref
->inode_list
,
911 (unsigned long *)&eie
, GFP_NOFS
);
912 if (!ret
&& extent_item_pos
) {
914 * we've recorded that parent, so we must extend
915 * its inode list here
920 eie
->next
= ref
->inode_list
;
929 mutex_unlock(&head
->mutex
);
930 btrfs_free_path(path
);
931 while (!list_empty(&prefs
)) {
932 ref
= list_first_entry(&prefs
, struct __prelim_ref
, list
);
933 list_del(&ref
->list
);
936 while (!list_empty(&prefs_delayed
)) {
937 ref
= list_first_entry(&prefs_delayed
, struct __prelim_ref
,
939 list_del(&ref
->list
);
946 static void free_leaf_list(struct ulist
*blocks
)
948 struct ulist_node
*node
= NULL
;
949 struct extent_inode_elem
*eie
;
950 struct extent_inode_elem
*eie_next
;
951 struct ulist_iterator uiter
;
953 ULIST_ITER_INIT(&uiter
);
954 while ((node
= ulist_next(blocks
, &uiter
))) {
957 eie
= (struct extent_inode_elem
*)node
->aux
;
958 for (; eie
; eie
= eie_next
) {
959 eie_next
= eie
->next
;
969 * Finds all leafs with a reference to the specified combination of bytenr and
970 * offset. key_list_head will point to a list of corresponding keys (caller must
971 * free each list element). The leafs will be stored in the leafs ulist, which
972 * must be freed with ulist_free.
974 * returns 0 on success, <0 on error
976 static int btrfs_find_all_leafs(struct btrfs_trans_handle
*trans
,
977 struct btrfs_fs_info
*fs_info
, u64 bytenr
,
978 u64 delayed_ref_seq
, u64 time_seq
,
979 struct ulist
**leafs
,
980 const u64
*extent_item_pos
)
985 tmp
= ulist_alloc(GFP_NOFS
);
988 *leafs
= ulist_alloc(GFP_NOFS
);
994 ret
= find_parent_nodes(trans
, fs_info
, bytenr
, delayed_ref_seq
,
995 time_seq
, *leafs
, tmp
, extent_item_pos
);
998 if (ret
< 0 && ret
!= -ENOENT
) {
999 free_leaf_list(*leafs
);
1007 * walk all backrefs for a given extent to find all roots that reference this
1008 * extent. Walking a backref means finding all extents that reference this
1009 * extent and in turn walk the backrefs of those, too. Naturally this is a
1010 * recursive process, but here it is implemented in an iterative fashion: We
1011 * find all referencing extents for the extent in question and put them on a
1012 * list. In turn, we find all referencing extents for those, further appending
1013 * to the list. The way we iterate the list allows adding more elements after
1014 * the current while iterating. The process stops when we reach the end of the
1015 * list. Found roots are added to the roots list.
1017 * returns 0 on success, < 0 on error.
1019 int btrfs_find_all_roots(struct btrfs_trans_handle
*trans
,
1020 struct btrfs_fs_info
*fs_info
, u64 bytenr
,
1021 u64 delayed_ref_seq
, u64 time_seq
,
1022 struct ulist
**roots
)
1025 struct ulist_node
*node
= NULL
;
1026 struct ulist_iterator uiter
;
1029 tmp
= ulist_alloc(GFP_NOFS
);
1032 *roots
= ulist_alloc(GFP_NOFS
);
1038 ULIST_ITER_INIT(&uiter
);
1040 ret
= find_parent_nodes(trans
, fs_info
, bytenr
, delayed_ref_seq
,
1041 time_seq
, tmp
, *roots
, NULL
);
1042 if (ret
< 0 && ret
!= -ENOENT
) {
1047 node
= ulist_next(tmp
, &uiter
);
1058 static int __inode_info(u64 inum
, u64 ioff
, u8 key_type
,
1059 struct btrfs_root
*fs_root
, struct btrfs_path
*path
,
1060 struct btrfs_key
*found_key
)
1063 struct btrfs_key key
;
1064 struct extent_buffer
*eb
;
1066 key
.type
= key_type
;
1067 key
.objectid
= inum
;
1070 ret
= btrfs_search_slot(NULL
, fs_root
, &key
, path
, 0, 0);
1074 eb
= path
->nodes
[0];
1075 if (ret
&& path
->slots
[0] >= btrfs_header_nritems(eb
)) {
1076 ret
= btrfs_next_leaf(fs_root
, path
);
1079 eb
= path
->nodes
[0];
1082 btrfs_item_key_to_cpu(eb
, found_key
, path
->slots
[0]);
1083 if (found_key
->type
!= key
.type
|| found_key
->objectid
!= key
.objectid
)
1090 * this makes the path point to (inum INODE_ITEM ioff)
1092 int inode_item_info(u64 inum
, u64 ioff
, struct btrfs_root
*fs_root
,
1093 struct btrfs_path
*path
)
1095 struct btrfs_key key
;
1096 return __inode_info(inum
, ioff
, BTRFS_INODE_ITEM_KEY
, fs_root
, path
,
1100 static int inode_ref_info(u64 inum
, u64 ioff
, struct btrfs_root
*fs_root
,
1101 struct btrfs_path
*path
,
1102 struct btrfs_key
*found_key
)
1104 return __inode_info(inum
, ioff
, BTRFS_INODE_REF_KEY
, fs_root
, path
,
1109 * this iterates to turn a btrfs_inode_ref into a full filesystem path. elements
1110 * of the path are separated by '/' and the path is guaranteed to be
1111 * 0-terminated. the path is only given within the current file system.
1112 * Therefore, it never starts with a '/'. the caller is responsible to provide
1113 * "size" bytes in "dest". the dest buffer will be filled backwards. finally,
1114 * the start point of the resulting string is returned. this pointer is within
1116 * in case the path buffer would overflow, the pointer is decremented further
1117 * as if output was written to the buffer, though no more output is actually
1118 * generated. that way, the caller can determine how much space would be
1119 * required for the path to fit into the buffer. in that case, the returned
1120 * value will be smaller than dest. callers must check this!
1122 static char *iref_to_path(struct btrfs_root
*fs_root
, struct btrfs_path
*path
,
1123 struct btrfs_inode_ref
*iref
,
1124 struct extent_buffer
*eb_in
, u64 parent
,
1125 char *dest
, u32 size
)
1131 s64 bytes_left
= size
- 1;
1132 struct extent_buffer
*eb
= eb_in
;
1133 struct btrfs_key found_key
;
1134 int leave_spinning
= path
->leave_spinning
;
1136 if (bytes_left
>= 0)
1137 dest
[bytes_left
] = '\0';
1139 path
->leave_spinning
= 1;
1141 len
= btrfs_inode_ref_name_len(eb
, iref
);
1143 if (bytes_left
>= 0)
1144 read_extent_buffer(eb
, dest
+ bytes_left
,
1145 (unsigned long)(iref
+ 1), len
);
1147 btrfs_tree_read_unlock_blocking(eb
);
1148 free_extent_buffer(eb
);
1150 ret
= inode_ref_info(parent
, 0, fs_root
, path
, &found_key
);
1155 next_inum
= found_key
.offset
;
1157 /* regular exit ahead */
1158 if (parent
== next_inum
)
1161 slot
= path
->slots
[0];
1162 eb
= path
->nodes
[0];
1163 /* make sure we can use eb after releasing the path */
1165 atomic_inc(&eb
->refs
);
1166 btrfs_tree_read_lock(eb
);
1167 btrfs_set_lock_blocking_rw(eb
, BTRFS_READ_LOCK
);
1169 btrfs_release_path(path
);
1171 iref
= btrfs_item_ptr(eb
, slot
, struct btrfs_inode_ref
);
1174 if (bytes_left
>= 0)
1175 dest
[bytes_left
] = '/';
1178 btrfs_release_path(path
);
1179 path
->leave_spinning
= leave_spinning
;
1182 return ERR_PTR(ret
);
1184 return dest
+ bytes_left
;
1188 * this makes the path point to (logical EXTENT_ITEM *)
1189 * returns BTRFS_EXTENT_FLAG_DATA for data, BTRFS_EXTENT_FLAG_TREE_BLOCK for
1190 * tree blocks and <0 on error.
1192 int extent_from_logical(struct btrfs_fs_info
*fs_info
, u64 logical
,
1193 struct btrfs_path
*path
, struct btrfs_key
*found_key
)
1198 struct extent_buffer
*eb
;
1199 struct btrfs_extent_item
*ei
;
1200 struct btrfs_key key
;
1202 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
1203 key
.objectid
= logical
;
1204 key
.offset
= (u64
)-1;
1206 ret
= btrfs_search_slot(NULL
, fs_info
->extent_root
, &key
, path
, 0, 0);
1209 ret
= btrfs_previous_item(fs_info
->extent_root
, path
,
1210 0, BTRFS_EXTENT_ITEM_KEY
);
1214 btrfs_item_key_to_cpu(path
->nodes
[0], found_key
, path
->slots
[0]);
1215 if (found_key
->type
!= BTRFS_EXTENT_ITEM_KEY
||
1216 found_key
->objectid
> logical
||
1217 found_key
->objectid
+ found_key
->offset
<= logical
) {
1218 pr_debug("logical %llu is not within any extent\n",
1219 (unsigned long long)logical
);
1223 eb
= path
->nodes
[0];
1224 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
1225 BUG_ON(item_size
< sizeof(*ei
));
1227 ei
= btrfs_item_ptr(eb
, path
->slots
[0], struct btrfs_extent_item
);
1228 flags
= btrfs_extent_flags(eb
, ei
);
1230 pr_debug("logical %llu is at position %llu within the extent (%llu "
1231 "EXTENT_ITEM %llu) flags %#llx size %u\n",
1232 (unsigned long long)logical
,
1233 (unsigned long long)(logical
- found_key
->objectid
),
1234 (unsigned long long)found_key
->objectid
,
1235 (unsigned long long)found_key
->offset
,
1236 (unsigned long long)flags
, item_size
);
1237 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
)
1238 return BTRFS_EXTENT_FLAG_TREE_BLOCK
;
1239 if (flags
& BTRFS_EXTENT_FLAG_DATA
)
1240 return BTRFS_EXTENT_FLAG_DATA
;
1246 * helper function to iterate extent inline refs. ptr must point to a 0 value
1247 * for the first call and may be modified. it is used to track state.
1248 * if more refs exist, 0 is returned and the next call to
1249 * __get_extent_inline_ref must pass the modified ptr parameter to get the
1250 * next ref. after the last ref was processed, 1 is returned.
1251 * returns <0 on error
1253 static int __get_extent_inline_ref(unsigned long *ptr
, struct extent_buffer
*eb
,
1254 struct btrfs_extent_item
*ei
, u32 item_size
,
1255 struct btrfs_extent_inline_ref
**out_eiref
,
1260 struct btrfs_tree_block_info
*info
;
1264 flags
= btrfs_extent_flags(eb
, ei
);
1265 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
1266 info
= (struct btrfs_tree_block_info
*)(ei
+ 1);
1268 (struct btrfs_extent_inline_ref
*)(info
+ 1);
1270 *out_eiref
= (struct btrfs_extent_inline_ref
*)(ei
+ 1);
1272 *ptr
= (unsigned long)*out_eiref
;
1273 if ((void *)*ptr
>= (void *)ei
+ item_size
)
1277 end
= (unsigned long)ei
+ item_size
;
1278 *out_eiref
= (struct btrfs_extent_inline_ref
*)*ptr
;
1279 *out_type
= btrfs_extent_inline_ref_type(eb
, *out_eiref
);
1281 *ptr
+= btrfs_extent_inline_ref_size(*out_type
);
1282 WARN_ON(*ptr
> end
);
1284 return 1; /* last */
1290 * reads the tree block backref for an extent. tree level and root are returned
1291 * through out_level and out_root. ptr must point to a 0 value for the first
1292 * call and may be modified (see __get_extent_inline_ref comment).
1293 * returns 0 if data was provided, 1 if there was no more data to provide or
1296 int tree_backref_for_extent(unsigned long *ptr
, struct extent_buffer
*eb
,
1297 struct btrfs_extent_item
*ei
, u32 item_size
,
1298 u64
*out_root
, u8
*out_level
)
1302 struct btrfs_tree_block_info
*info
;
1303 struct btrfs_extent_inline_ref
*eiref
;
1305 if (*ptr
== (unsigned long)-1)
1309 ret
= __get_extent_inline_ref(ptr
, eb
, ei
, item_size
,
1314 if (type
== BTRFS_TREE_BLOCK_REF_KEY
||
1315 type
== BTRFS_SHARED_BLOCK_REF_KEY
)
1322 /* we can treat both ref types equally here */
1323 info
= (struct btrfs_tree_block_info
*)(ei
+ 1);
1324 *out_root
= btrfs_extent_inline_ref_offset(eb
, eiref
);
1325 *out_level
= btrfs_tree_block_level(eb
, info
);
1328 *ptr
= (unsigned long)-1;
1333 static int iterate_leaf_refs(struct extent_inode_elem
*inode_list
,
1334 u64 root
, u64 extent_item_objectid
,
1335 iterate_extent_inodes_t
*iterate
, void *ctx
)
1337 struct extent_inode_elem
*eie
;
1340 for (eie
= inode_list
; eie
; eie
= eie
->next
) {
1341 pr_debug("ref for %llu resolved, key (%llu EXTEND_DATA %llu), "
1342 "root %llu\n", extent_item_objectid
,
1343 eie
->inum
, eie
->offset
, root
);
1344 ret
= iterate(eie
->inum
, eie
->offset
, root
, ctx
);
1346 pr_debug("stopping iteration for %llu due to ret=%d\n",
1347 extent_item_objectid
, ret
);
1356 * calls iterate() for every inode that references the extent identified by
1357 * the given parameters.
1358 * when the iterator function returns a non-zero value, iteration stops.
1360 int iterate_extent_inodes(struct btrfs_fs_info
*fs_info
,
1361 u64 extent_item_objectid
, u64 extent_item_pos
,
1362 int search_commit_root
,
1363 iterate_extent_inodes_t
*iterate
, void *ctx
)
1366 struct list_head data_refs
= LIST_HEAD_INIT(data_refs
);
1367 struct list_head shared_refs
= LIST_HEAD_INIT(shared_refs
);
1368 struct btrfs_trans_handle
*trans
;
1369 struct ulist
*refs
= NULL
;
1370 struct ulist
*roots
= NULL
;
1371 struct ulist_node
*ref_node
= NULL
;
1372 struct ulist_node
*root_node
= NULL
;
1373 struct seq_list seq_elem
= {};
1374 struct seq_list tree_mod_seq_elem
= {};
1375 struct ulist_iterator ref_uiter
;
1376 struct ulist_iterator root_uiter
;
1377 struct btrfs_delayed_ref_root
*delayed_refs
= NULL
;
1379 pr_debug("resolving all inodes for extent %llu\n",
1380 extent_item_objectid
);
1382 if (search_commit_root
) {
1383 trans
= BTRFS_BACKREF_SEARCH_COMMIT_ROOT
;
1385 trans
= btrfs_join_transaction(fs_info
->extent_root
);
1387 return PTR_ERR(trans
);
1389 delayed_refs
= &trans
->transaction
->delayed_refs
;
1390 spin_lock(&delayed_refs
->lock
);
1391 btrfs_get_delayed_seq(delayed_refs
, &seq_elem
);
1392 spin_unlock(&delayed_refs
->lock
);
1393 btrfs_get_tree_mod_seq(fs_info
, &tree_mod_seq_elem
);
1396 ret
= btrfs_find_all_leafs(trans
, fs_info
, extent_item_objectid
,
1397 seq_elem
.seq
, tree_mod_seq_elem
.seq
, &refs
,
1402 ULIST_ITER_INIT(&ref_uiter
);
1403 while (!ret
&& (ref_node
= ulist_next(refs
, &ref_uiter
))) {
1404 ret
= btrfs_find_all_roots(trans
, fs_info
, ref_node
->val
,
1406 tree_mod_seq_elem
.seq
, &roots
);
1409 ULIST_ITER_INIT(&root_uiter
);
1410 while (!ret
&& (root_node
= ulist_next(roots
, &root_uiter
))) {
1411 pr_debug("root %llu references leaf %llu, data list "
1412 "%#lx\n", root_node
->val
, ref_node
->val
,
1414 ret
= iterate_leaf_refs(
1415 (struct extent_inode_elem
*)ref_node
->aux
,
1416 root_node
->val
, extent_item_objectid
,
1423 free_leaf_list(refs
);
1426 if (!search_commit_root
) {
1427 btrfs_put_tree_mod_seq(fs_info
, &tree_mod_seq_elem
);
1428 btrfs_put_delayed_seq(delayed_refs
, &seq_elem
);
1429 btrfs_end_transaction(trans
, fs_info
->extent_root
);
1435 int iterate_inodes_from_logical(u64 logical
, struct btrfs_fs_info
*fs_info
,
1436 struct btrfs_path
*path
,
1437 iterate_extent_inodes_t
*iterate
, void *ctx
)
1440 u64 extent_item_pos
;
1441 struct btrfs_key found_key
;
1442 int search_commit_root
= path
->search_commit_root
;
1444 ret
= extent_from_logical(fs_info
, logical
, path
,
1446 btrfs_release_path(path
);
1447 if (ret
& BTRFS_EXTENT_FLAG_TREE_BLOCK
)
1452 extent_item_pos
= logical
- found_key
.objectid
;
1453 ret
= iterate_extent_inodes(fs_info
, found_key
.objectid
,
1454 extent_item_pos
, search_commit_root
,
1460 static int iterate_irefs(u64 inum
, struct btrfs_root
*fs_root
,
1461 struct btrfs_path
*path
,
1462 iterate_irefs_t
*iterate
, void *ctx
)
1471 struct extent_buffer
*eb
;
1472 struct btrfs_item
*item
;
1473 struct btrfs_inode_ref
*iref
;
1474 struct btrfs_key found_key
;
1477 path
->leave_spinning
= 1;
1478 ret
= inode_ref_info(inum
, parent
? parent
+1 : 0, fs_root
, path
,
1483 ret
= found
? 0 : -ENOENT
;
1488 parent
= found_key
.offset
;
1489 slot
= path
->slots
[0];
1490 eb
= path
->nodes
[0];
1491 /* make sure we can use eb after releasing the path */
1492 atomic_inc(&eb
->refs
);
1493 btrfs_tree_read_lock(eb
);
1494 btrfs_set_lock_blocking_rw(eb
, BTRFS_READ_LOCK
);
1495 btrfs_release_path(path
);
1497 item
= btrfs_item_nr(eb
, slot
);
1498 iref
= btrfs_item_ptr(eb
, slot
, struct btrfs_inode_ref
);
1500 for (cur
= 0; cur
< btrfs_item_size(eb
, item
); cur
+= len
) {
1501 name_len
= btrfs_inode_ref_name_len(eb
, iref
);
1502 /* path must be released before calling iterate()! */
1503 pr_debug("following ref at offset %u for inode %llu in "
1505 (unsigned long long)found_key
.objectid
,
1506 (unsigned long long)fs_root
->objectid
);
1507 ret
= iterate(parent
, iref
, eb
, ctx
);
1510 len
= sizeof(*iref
) + name_len
;
1511 iref
= (struct btrfs_inode_ref
*)((char *)iref
+ len
);
1513 btrfs_tree_read_unlock_blocking(eb
);
1514 free_extent_buffer(eb
);
1517 btrfs_release_path(path
);
1523 * returns 0 if the path could be dumped (probably truncated)
1524 * returns <0 in case of an error
1526 static int inode_to_path(u64 inum
, struct btrfs_inode_ref
*iref
,
1527 struct extent_buffer
*eb
, void *ctx
)
1529 struct inode_fs_paths
*ipath
= ctx
;
1532 int i
= ipath
->fspath
->elem_cnt
;
1533 const int s_ptr
= sizeof(char *);
1536 bytes_left
= ipath
->fspath
->bytes_left
> s_ptr
?
1537 ipath
->fspath
->bytes_left
- s_ptr
: 0;
1539 fspath_min
= (char *)ipath
->fspath
->val
+ (i
+ 1) * s_ptr
;
1540 fspath
= iref_to_path(ipath
->fs_root
, ipath
->btrfs_path
, iref
, eb
,
1541 inum
, fspath_min
, bytes_left
);
1543 return PTR_ERR(fspath
);
1545 if (fspath
> fspath_min
) {
1546 pr_debug("path resolved: %s\n", fspath
);
1547 ipath
->fspath
->val
[i
] = (u64
)(unsigned long)fspath
;
1548 ++ipath
->fspath
->elem_cnt
;
1549 ipath
->fspath
->bytes_left
= fspath
- fspath_min
;
1551 pr_debug("missed path, not enough space. missing bytes: %lu, "
1552 "constructed so far: %s\n",
1553 (unsigned long)(fspath_min
- fspath
), fspath_min
);
1554 ++ipath
->fspath
->elem_missed
;
1555 ipath
->fspath
->bytes_missing
+= fspath_min
- fspath
;
1556 ipath
->fspath
->bytes_left
= 0;
1563 * this dumps all file system paths to the inode into the ipath struct, provided
1564 * is has been created large enough. each path is zero-terminated and accessed
1565 * from ipath->fspath->val[i].
1566 * when it returns, there are ipath->fspath->elem_cnt number of paths available
1567 * in ipath->fspath->val[]. when the allocated space wasn't sufficient, the
1568 * number of missed paths in recored in ipath->fspath->elem_missed, otherwise,
1569 * it's zero. ipath->fspath->bytes_missing holds the number of bytes that would
1570 * have been needed to return all paths.
1572 int paths_from_inode(u64 inum
, struct inode_fs_paths
*ipath
)
1574 return iterate_irefs(inum
, ipath
->fs_root
, ipath
->btrfs_path
,
1575 inode_to_path
, ipath
);
1578 struct btrfs_data_container
*init_data_container(u32 total_bytes
)
1580 struct btrfs_data_container
*data
;
1583 alloc_bytes
= max_t(size_t, total_bytes
, sizeof(*data
));
1584 data
= kmalloc(alloc_bytes
, GFP_NOFS
);
1586 return ERR_PTR(-ENOMEM
);
1588 if (total_bytes
>= sizeof(*data
)) {
1589 data
->bytes_left
= total_bytes
- sizeof(*data
);
1590 data
->bytes_missing
= 0;
1592 data
->bytes_missing
= sizeof(*data
) - total_bytes
;
1593 data
->bytes_left
= 0;
1597 data
->elem_missed
= 0;
1603 * allocates space to return multiple file system paths for an inode.
1604 * total_bytes to allocate are passed, note that space usable for actual path
1605 * information will be total_bytes - sizeof(struct inode_fs_paths).
1606 * the returned pointer must be freed with free_ipath() in the end.
1608 struct inode_fs_paths
*init_ipath(s32 total_bytes
, struct btrfs_root
*fs_root
,
1609 struct btrfs_path
*path
)
1611 struct inode_fs_paths
*ifp
;
1612 struct btrfs_data_container
*fspath
;
1614 fspath
= init_data_container(total_bytes
);
1616 return (void *)fspath
;
1618 ifp
= kmalloc(sizeof(*ifp
), GFP_NOFS
);
1621 return ERR_PTR(-ENOMEM
);
1624 ifp
->btrfs_path
= path
;
1625 ifp
->fspath
= fspath
;
1626 ifp
->fs_root
= fs_root
;
1631 void free_ipath(struct inode_fs_paths
*ipath
)
1635 kfree(ipath
->fspath
);