1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#ifndef BTRFS_CTREE_H
7#define BTRFS_CTREE_H
8
9#include <linux/cleanup.h>
10#include <linux/spinlock.h>
11#include <linux/rbtree.h>
12#include <linux/mutex.h>
13#include <linux/wait.h>
14#include <linux/list.h>
15#include <linux/atomic.h>
16#include <linux/xarray.h>
17#include <linux/refcount.h>
18#include <uapi/linux/btrfs_tree.h>
19#include "locking.h"
20#include "accessors.h"
21
22struct extent_buffer;
23struct btrfs_block_rsv;
24struct btrfs_trans_handle;
25struct btrfs_block_group;
26
27/* Read ahead values for struct btrfs_path.reada */
28enum {
29 READA_NONE,
30 READA_BACK,
31 READA_FORWARD,
32 /*
33 * Similar to READA_FORWARD but unlike it:
34 *
35 * 1) It will trigger readahead even for leaves that are not close to
36 * each other on disk;
37 * 2) It also triggers readahead for nodes;
38 * 3) During a search, even when a node or leaf is already in memory, it
39 * will still trigger readahead for other nodes and leaves that follow
40 * it.
41 *
42 * This is meant to be used only when we know we are iterating over the
43 * entire tree or a very large part of it.
44 */
45 READA_FORWARD_ALWAYS,
46};
47
48/*
49 * btrfs_paths remember the path taken from the root down to the leaf.
50 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
51 * to any other levels that are present.
52 *
53 * The slots array records the index of the item or block pointer
54 * used while walking the tree.
55 */
56struct btrfs_path {
57 struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
58 int slots[BTRFS_MAX_LEVEL];
59 /* if there is real range locking, this locks field will change */
60 u8 locks[BTRFS_MAX_LEVEL];
61 u8 reada;
62 u8 lowest_level;
63
64 /*
65 * set by btrfs_split_item, tells search_slot to keep all locks
66 * and to force calls to keep space in the nodes
67 */
68 bool search_for_split:1;
69 /* Keep some upper locks as we walk down. */
70 bool keep_locks:1;
71 bool skip_locking:1;
72 bool search_commit_root:1;
73 bool need_commit_sem:1;
74 bool skip_release_on_error:1;
75 /*
76 * Indicate that new item (btrfs_search_slot) is extending already
77 * existing item and ins_len contains only the data size and not item
78 * header (ie. sizeof(struct btrfs_item) is not included).
79 */
80 bool search_for_extension:1;
81 /* Stop search if any locks need to be taken (for read) */
82 bool nowait:1;
83};
84
85#define BTRFS_PATH_AUTO_FREE(path_name) \
86 struct btrfs_path *path_name __free(btrfs_free_path) = NULL
87
88/*
89 * The state of btrfs root
90 */
91enum {
92 /*
93 * btrfs_record_root_in_trans is a multi-step process, and it can race
94 * with the balancing code. But the race is very small, and only the
95 * first time the root is added to each transaction. So IN_TRANS_SETUP
96 * is used to tell us when more checks are required
97 */
98 BTRFS_ROOT_IN_TRANS_SETUP,
99
100 /*
101 * Set if tree blocks of this root can be shared by other roots.
102 * Only subvolume trees and their reloc trees have this bit set.
103 * Conflicts with TRACK_DIRTY bit.
104 *
105 * This affects two things:
106 *
107 * - How balance works
108 * For shareable roots, we need to use reloc tree and do path
109 * replacement for balance, and need various pre/post hooks for
110 * snapshot creation to handle them.
111 *
112 * While for non-shareable trees, we just simply do a tree search
113 * with COW.
114 *
115 * - How dirty roots are tracked
116 * For shareable roots, btrfs_record_root_in_trans() is needed to
117 * track them, while non-subvolume roots have TRACK_DIRTY bit, they
118 * don't need to set this manually.
119 */
120 BTRFS_ROOT_SHAREABLE,
121 BTRFS_ROOT_TRACK_DIRTY,
122 BTRFS_ROOT_IN_RADIX,
123 BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
124 BTRFS_ROOT_DEFRAG_RUNNING,
125 BTRFS_ROOT_FORCE_COW,
126 BTRFS_ROOT_MULTI_LOG_TASKS,
127 BTRFS_ROOT_DIRTY,
128 BTRFS_ROOT_DELETING,
129
130 /*
131 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
132 *
133 * Set for the subvolume tree owning the reloc tree.
134 */
135 BTRFS_ROOT_DEAD_RELOC_TREE,
136 /* Mark dead root stored on device whose cleanup needs to be resumed */
137 BTRFS_ROOT_DEAD_TREE,
138 /* The root has a log tree. Used for subvolume roots and the tree root. */
139 BTRFS_ROOT_HAS_LOG_TREE,
140 /* Qgroup flushing is in progress */
141 BTRFS_ROOT_QGROUP_FLUSHING,
142 /* We started the orphan cleanup for this root. */
143 BTRFS_ROOT_ORPHAN_CLEANUP,
144 /* This root has a drop operation that was started previously. */
145 BTRFS_ROOT_UNFINISHED_DROP,
146 /* This reloc root needs to have its buffers lockdep class reset. */
147 BTRFS_ROOT_RESET_LOCKDEP_CLASS,
148};
149
150/*
151 * Record swapped tree blocks of a subvolume tree for delayed subtree trace
152 * code. For detail check comment in fs/btrfs/qgroup.c.
153 */
154struct btrfs_qgroup_swapped_blocks {
155 spinlock_t lock;
156 /* RM_EMPTY_ROOT() of above blocks[] */
157 bool swapped;
158 struct rb_root blocks[BTRFS_MAX_LEVEL];
159};
160
161/*
162 * in ram representation of the tree. extent_root is used for all allocations
163 * and for the extent tree extent_root root.
164 */
165struct btrfs_root {
166 struct rb_node rb_node;
167
168 struct extent_buffer *node;
169
170 struct extent_buffer *commit_root;
171 struct btrfs_root *log_root;
172 struct btrfs_root *reloc_root;
173
174 unsigned long state;
175 struct btrfs_root_item root_item;
176 struct btrfs_key root_key;
177 struct btrfs_fs_info *fs_info;
178 struct extent_io_tree dirty_log_pages;
179
180 struct mutex objectid_mutex;
181
182 spinlock_t accounting_lock;
183 struct btrfs_block_rsv *block_rsv;
184
185 struct mutex log_mutex;
186 wait_queue_head_t log_writer_wait;
187 wait_queue_head_t log_commit_wait[2];
188 struct list_head log_ctxs[2];
189 /* Used only for log trees of subvolumes, not for the log root tree */
190 atomic_t log_writers;
191 atomic_t log_commit[2];
192 /* Used only for log trees of subvolumes, not for the log root tree */
193 atomic_t log_batch;
194 /*
195 * Protected by the 'log_mutex' lock but can be read without holding
196 * that lock to avoid unnecessary lock contention, in which case it
197 * should be read using btrfs_get_root_log_transid() except if it's a
198 * log tree in which case it can be directly accessed. Updates to this
199 * field should always use btrfs_set_root_log_transid(), except for log
200 * trees where the field can be updated directly.
201 */
202 int log_transid;
203 /* No matter the commit succeeds or not*/
204 int log_transid_committed;
205 /*
206 * Just be updated when the commit succeeds. Use
207 * btrfs_get_root_last_log_commit() and btrfs_set_root_last_log_commit()
208 * to access this field.
209 */
210 int last_log_commit;
211 pid_t log_start_pid;
212
213 u64 last_trans;
214
215 u64 free_objectid;
216
217 struct btrfs_key defrag_progress;
218 struct btrfs_key defrag_max;
219
220 /* The dirty list is only used by non-shareable roots */
221 struct list_head dirty_list;
222
223 struct list_head root_list;
224
225 /* Xarray that keeps track of in-memory inodes. */
226 struct xarray inodes;
227
228 /* Xarray that keeps track of delayed nodes of every inode. */
229 struct xarray delayed_nodes;
230 /*
231 * right now this just gets used so that a root has its own devid
232 * for stat. It may be used for more later
233 */
234 dev_t anon_dev;
235
236 spinlock_t root_item_lock;
237 refcount_t refs;
238
239 struct mutex delalloc_mutex;
240 spinlock_t delalloc_lock;
241 /*
242 * all of the inodes that have delalloc bytes. It is possible for
243 * this list to be empty even when there is still dirty data=ordered
244 * extents waiting to finish IO.
245 */
246 struct list_head delalloc_inodes;
247 struct list_head delalloc_root;
248 u64 nr_delalloc_inodes;
249
250 struct mutex ordered_extent_mutex;
251 /*
252 * this is used by the balancing code to wait for all the pending
253 * ordered extents
254 */
255 spinlock_t ordered_extent_lock;
256
257 /*
258 * all of the data=ordered extents pending writeback
259 * these can span multiple transactions and basically include
260 * every dirty data page that isn't from nodatacow
261 */
262 struct list_head ordered_extents;
263 struct list_head ordered_root;
264 u64 nr_ordered_extents;
265
266 /*
267 * Not empty if this subvolume root has gone through tree block swap
268 * (relocation)
269 *
270 * Will be used by reloc_control::dirty_subvol_roots.
271 */
272 struct list_head reloc_dirty_list;
273
274 /*
275 * Number of currently running SEND ioctls to prevent
276 * manipulation with the read-only status via SUBVOL_SETFLAGS
277 */
278 int send_in_progress;
279 /*
280 * Number of currently running deduplication operations that have a
281 * destination inode belonging to this root. Protected by the lock
282 * root_item_lock.
283 */
284 int dedupe_in_progress;
285 /* For exclusion of snapshot creation and nocow writes */
286 struct btrfs_drew_lock snapshot_lock;
287
288 atomic_t snapshot_force_cow;
289
290 /* For qgroup metadata reserved space */
291 spinlock_t qgroup_meta_rsv_lock;
292 u64 qgroup_meta_rsv_pertrans;
293 u64 qgroup_meta_rsv_prealloc;
294 wait_queue_head_t qgroup_flush_wait;
295
296 /* Number of active swapfiles */
297 atomic_t nr_swapfiles;
298
299 /* Record pairs of swapped blocks for qgroup */
300 struct btrfs_qgroup_swapped_blocks swapped_blocks;
301
302 /* Used only by log trees, when logging csum items */
303 struct extent_io_tree log_csum_range;
304
305 /* Used in simple quotas, track root during relocation. */
306 u64 relocation_src_root;
307
308#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
309 u64 alloc_bytenr;
310#endif
311
312#ifdef CONFIG_BTRFS_DEBUG
313 struct list_head leak_list;
314#endif
315};
316
317static inline bool btrfs_root_readonly(const struct btrfs_root *root)
318{
319 /* Byte-swap the constant at compile time, root_item::flags is LE */
320 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
321}
322
323static inline bool btrfs_root_dead(const struct btrfs_root *root)
324{
325 /* Byte-swap the constant at compile time, root_item::flags is LE */
326 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
327}
328
329static inline u64 btrfs_root_id(const struct btrfs_root *root)
330{
331 return root->root_key.objectid;
332}
333
334static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
335{
336 return READ_ONCE(root->log_transid);
337}
338
339static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
340{
341 WRITE_ONCE(root->log_transid, log_transid);
342}
343
344static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
345{
346 return READ_ONCE(root->last_log_commit);
347}
348
349static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
350{
351 WRITE_ONCE(root->last_log_commit, commit_id);
352}
353
354static inline u64 btrfs_get_root_last_trans(const struct btrfs_root *root)
355{
356 return READ_ONCE(root->last_trans);
357}
358
359static inline void btrfs_set_root_last_trans(struct btrfs_root *root, u64 transid)
360{
361 WRITE_ONCE(root->last_trans, transid);
362}
363
364/*
365 * Return the generation this root started with.
366 *
367 * Every normal root that is created with root->root_key.offset set to it's
368 * originating generation. If it is a snapshot it is the generation when the
369 * snapshot was created.
370 *
371 * However for TREE_RELOC roots root_key.offset is the objectid of the owning
372 * tree root. Thankfully we copy the root item of the owning tree root, which
373 * has it's last_snapshot set to what we would have root_key.offset set to, so
374 * return that if this is a TREE_RELOC root.
375 */
376static inline u64 btrfs_root_origin_generation(const struct btrfs_root *root)
377{
378 if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID)
379 return btrfs_root_last_snapshot(s: &root->root_item);
380 return root->root_key.offset;
381}
382
383/*
384 * Structure that conveys information about an extent that is going to replace
385 * all the extents in a file range.
386 */
387struct btrfs_replace_extent_info {
388 u64 disk_offset;
389 u64 disk_len;
390 u64 data_offset;
391 u64 data_len;
392 u64 file_offset;
393 /* Pointer to a file extent item of type regular or prealloc. */
394 char *extent_buf;
395 /*
396 * Set to true when attempting to replace a file range with a new extent
397 * described by this structure, set to false when attempting to clone an
398 * existing extent into a file range.
399 */
400 bool is_new_extent;
401 /* Indicate if we should update the inode's mtime and ctime. */
402 bool update_times;
403 /* Meaningful only if is_new_extent is true. */
404 int qgroup_reserved;
405 /*
406 * Meaningful only if is_new_extent is true.
407 * Used to track how many extent items we have already inserted in a
408 * subvolume tree that refer to the extent described by this structure,
409 * so that we know when to create a new delayed ref or update an existing
410 * one.
411 */
412 int insertions;
413};
414
415/* Arguments for btrfs_drop_extents() */
416struct btrfs_drop_extents_args {
417 /* Input parameters */
418
419 /*
420 * If NULL, btrfs_drop_extents() will allocate and free its own path.
421 * If 'replace_extent' is true, this must not be NULL. Also the path
422 * is always released except if 'replace_extent' is true and
423 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
424 * the path is kept locked.
425 */
426 struct btrfs_path *path;
427 /* Start offset of the range to drop extents from */
428 u64 start;
429 /* End (exclusive, last byte + 1) of the range to drop extents from */
430 u64 end;
431 /* If true drop all the extent maps in the range */
432 bool drop_cache;
433 /*
434 * If true it means we want to insert a new extent after dropping all
435 * the extents in the range. If this is true, the 'extent_item_size'
436 * parameter must be set as well and the 'extent_inserted' field will
437 * be set to true by btrfs_drop_extents() if it could insert the new
438 * extent.
439 * Note: when this is set to true the path must not be NULL.
440 */
441 bool replace_extent;
442 /*
443 * Used if 'replace_extent' is true. Size of the file extent item to
444 * insert after dropping all existing extents in the range
445 */
446 u32 extent_item_size;
447
448 /* Output parameters */
449
450 /*
451 * Set to the minimum between the input parameter 'end' and the end
452 * (exclusive, last byte + 1) of the last dropped extent. This is always
453 * set even if btrfs_drop_extents() returns an error.
454 */
455 u64 drop_end;
456 /*
457 * The number of allocated bytes found in the range. This can be smaller
458 * than the range's length when there are holes in the range.
459 */
460 u64 bytes_found;
461 /*
462 * Only set if 'replace_extent' is true. Set to true if we were able
463 * to insert a replacement extent after dropping all extents in the
464 * range, otherwise set to false by btrfs_drop_extents().
465 * Also, if btrfs_drop_extents() has set this to true it means it
466 * returned with the path locked, otherwise if it has set this to
467 * false it has returned with the path released.
468 */
469 bool extent_inserted;
470};
471
472struct btrfs_file_private {
473 void *filldir_buf;
474 u64 last_index;
475 struct extent_state *llseek_cached_state;
476 /* Task that allocated this structure. */
477 struct task_struct *owner_task;
478};
479
480static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
481{
482 return info->nodesize - sizeof(struct btrfs_header);
483}
484
485static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
486{
487 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
488}
489
490static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
491{
492 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
493}
494
495static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
496{
497 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
498}
499
500int __init btrfs_ctree_init(void);
501void __cold btrfs_ctree_exit(void);
502
503int btrfs_bin_search(const struct extent_buffer *eb, int first_slot,
504 const struct btrfs_key *key, int *slot);
505
506int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
507
508#ifdef __LITTLE_ENDIAN
509
510/*
511 * Compare two keys, on little-endian the disk order is same as CPU order and
512 * we can avoid the conversion.
513 */
514static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
515 const struct btrfs_key *k2)
516{
517 const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
518
519 return btrfs_comp_cpu_keys(k1, k2);
520}
521
522#else
523
524/* Compare two keys in a memcmp fashion. */
525static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
526 const struct btrfs_key *k2)
527{
528 struct btrfs_key k1;
529
530 btrfs_disk_key_to_cpu(&k1, disk);
531
532 return btrfs_comp_cpu_keys(&k1, k2);
533}
534
535#endif
536
537int btrfs_previous_item(struct btrfs_root *root,
538 struct btrfs_path *path, u64 min_objectid,
539 int type);
540int btrfs_previous_extent_item(struct btrfs_root *root,
541 struct btrfs_path *path, u64 min_objectid);
542void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
543 const struct btrfs_path *path,
544 const struct btrfs_key *new_key);
545struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
546int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
547 struct btrfs_key *key, int lowest_level,
548 u64 min_trans);
549int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
550 struct btrfs_path *path,
551 u64 min_trans);
552struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
553 int slot);
554
555int btrfs_cow_block(struct btrfs_trans_handle *trans,
556 struct btrfs_root *root, struct extent_buffer *buf,
557 struct extent_buffer *parent, int parent_slot,
558 struct extent_buffer **cow_ret,
559 enum btrfs_lock_nesting nest);
560int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
561 struct btrfs_root *root,
562 struct extent_buffer *buf,
563 struct extent_buffer *parent, int parent_slot,
564 struct extent_buffer **cow_ret,
565 u64 search_start, u64 empty_size,
566 enum btrfs_lock_nesting nest);
567int btrfs_copy_root(struct btrfs_trans_handle *trans,
568 struct btrfs_root *root,
569 struct extent_buffer *buf,
570 struct extent_buffer **cow_ret, u64 new_root_objectid);
571bool btrfs_block_can_be_shared(const struct btrfs_trans_handle *trans,
572 const struct btrfs_root *root,
573 const struct extent_buffer *buf);
574int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
575 struct btrfs_path *path, int level, int slot);
576void btrfs_extend_item(struct btrfs_trans_handle *trans,
577 const struct btrfs_path *path, u32 data_size);
578void btrfs_truncate_item(struct btrfs_trans_handle *trans,
579 const struct btrfs_path *path, u32 new_size, int from_end);
580int btrfs_split_item(struct btrfs_trans_handle *trans,
581 struct btrfs_root *root,
582 struct btrfs_path *path,
583 const struct btrfs_key *new_key,
584 unsigned long split_offset);
585int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
586 struct btrfs_root *root,
587 struct btrfs_path *path,
588 const struct btrfs_key *new_key);
589int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
590 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
591int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
592 const struct btrfs_key *key, struct btrfs_path *p,
593 int ins_len, int cow);
594int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
595 struct btrfs_path *p, u64 time_seq);
596int btrfs_search_slot_for_read(struct btrfs_root *root,
597 const struct btrfs_key *key,
598 struct btrfs_path *p, int find_higher,
599 int return_any);
600void btrfs_release_path(struct btrfs_path *p);
601struct btrfs_path *btrfs_alloc_path(void);
602void btrfs_free_path(struct btrfs_path *p);
603DEFINE_FREE(btrfs_free_path, struct btrfs_path *, btrfs_free_path(_T))
604
605int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
606 struct btrfs_path *path, int slot, int nr);
607static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
608 struct btrfs_root *root,
609 struct btrfs_path *path)
610{
611 return btrfs_del_items(trans, root, path, slot: path->slots[0], nr: 1);
612}
613
614/*
615 * Describes a batch of items to insert in a btree. This is used by
616 * btrfs_insert_empty_items().
617 */
618struct btrfs_item_batch {
619 /*
620 * Pointer to an array containing the keys of the items to insert (in
621 * sorted order).
622 */
623 const struct btrfs_key *keys;
624 /* Pointer to an array containing the data size for each item to insert. */
625 const u32 *data_sizes;
626 /*
627 * The sum of data sizes for all items. The caller can compute this while
628 * setting up the data_sizes array, so it ends up being more efficient
629 * than having btrfs_insert_empty_items() or setup_item_for_insert()
630 * doing it, as it would avoid an extra loop over a potentially large
631 * array, and in the case of setup_item_for_insert(), we would be doing
632 * it while holding a write lock on a leaf and often on upper level nodes
633 * too, unnecessarily increasing the size of a critical section.
634 */
635 u32 total_data_size;
636 /* Size of the keys and data_sizes arrays (number of items in the batch). */
637 int nr;
638};
639
640void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
641 struct btrfs_root *root,
642 struct btrfs_path *path,
643 const struct btrfs_key *key,
644 u32 data_size);
645int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
646 const struct btrfs_key *key, void *data, u32 data_size);
647int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
648 struct btrfs_root *root,
649 struct btrfs_path *path,
650 const struct btrfs_item_batch *batch);
651
652static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
653 struct btrfs_root *root,
654 struct btrfs_path *path,
655 const struct btrfs_key *key,
656 u32 data_size)
657{
658 struct btrfs_item_batch batch;
659
660 batch.keys = key;
661 batch.data_sizes = &data_size;
662 batch.total_data_size = data_size;
663 batch.nr = 1;
664
665 return btrfs_insert_empty_items(trans, root, path, batch: &batch);
666}
667
668int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
669 u64 time_seq);
670
671int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
672 struct btrfs_path *path);
673
674int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
675 struct btrfs_path *path);
676
677/*
678 * Search in @root for a given @key, and store the slot found in @found_key.
679 *
680 * @root: The root node of the tree.
681 * @key: The key we are looking for.
682 * @found_key: Will hold the found item.
683 * @path: Holds the current slot/leaf.
684 * @iter_ret: Contains the value returned from btrfs_search_slot or
685 * btrfs_get_next_valid_item, whichever was executed last.
686 *
687 * The @iter_ret is an output variable that will contain the return value of
688 * btrfs_search_slot, if it encountered an error, or the value returned from
689 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
690 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
691 *
692 * It's recommended to use a separate variable for iter_ret and then use it to
693 * set the function return value so there's no confusion of the 0/1/errno
694 * values stemming from btrfs_search_slot.
695 */
696#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
697 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
698 (iter_ret) >= 0 && \
699 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
700 (path)->slots[0]++ \
701 )
702
703int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
704
705/*
706 * Search the tree again to find a leaf with greater keys.
707 *
708 * Returns 0 if it found something or 1 if there are no greater leaves.
709 * Returns < 0 on error.
710 */
711static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
712{
713 return btrfs_next_old_leaf(root, path, time_seq: 0);
714}
715
716static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
717{
718 return btrfs_next_old_item(root, path: p, time_seq: 0);
719}
720int btrfs_leaf_free_space(const struct extent_buffer *leaf);
721
722static inline bool btrfs_is_fstree(u64 rootid)
723{
724 if (rootid == BTRFS_FS_TREE_OBJECTID)
725 return true;
726
727 if ((s64)rootid < (s64)BTRFS_FIRST_FREE_OBJECTID)
728 return false;
729
730 if (btrfs_qgroup_level(qgroupid: rootid) != 0)
731 return false;
732
733 return true;
734}
735
736static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
737{
738 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
739}
740
741#endif
742

source code of linux/fs/btrfs/ctree.h