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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/pagemap.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 "fs.h"
21#include "accessors.h"
22#include "extent-io-tree.h"
23
24struct extent_buffer;
25struct btrfs_block_rsv;
26struct btrfs_trans_handle;
27struct btrfs_block_group;
28
29/* Read ahead values for struct btrfs_path.reada */
30enum {
31 READA_NONE,
32 READA_BACK,
33 READA_FORWARD,
34 /*
35 * Similar to READA_FORWARD but unlike it:
36 *
37 * 1) It will trigger readahead even for leaves that are not close to
38 * each other on disk;
39 * 2) It also triggers readahead for nodes;
40 * 3) During a search, even when a node or leaf is already in memory, it
41 * will still trigger readahead for other nodes and leaves that follow
42 * it.
43 *
44 * This is meant to be used only when we know we are iterating over the
45 * entire tree or a very large part of it.
46 */
47 READA_FORWARD_ALWAYS,
48};
49
50/*
51 * btrfs_paths remember the path taken from the root down to the leaf.
52 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
53 * to any other levels that are present.
54 *
55 * The slots array records the index of the item or block pointer
56 * used while walking the tree.
57 */
58struct btrfs_path {
59 struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
60 int slots[BTRFS_MAX_LEVEL];
61 /* if there is real range locking, this locks field will change */
62 u8 locks[BTRFS_MAX_LEVEL];
63 u8 reada;
64 /* keep some upper locks as we walk down */
65 u8 lowest_level;
66
67 /*
68 * set by btrfs_split_item, tells search_slot to keep all locks
69 * and to force calls to keep space in the nodes
70 */
71 unsigned int search_for_split:1;
72 unsigned int keep_locks:1;
73 unsigned int skip_locking:1;
74 unsigned int search_commit_root:1;
75 unsigned int need_commit_sem:1;
76 unsigned int skip_release_on_error:1;
77 /*
78 * Indicate that new item (btrfs_search_slot) is extending already
79 * existing item and ins_len contains only the data size and not item
80 * header (ie. sizeof(struct btrfs_item) is not included).
81 */
82 unsigned int search_for_extension:1;
83 /* Stop search if any locks need to be taken (for read) */
84 unsigned int nowait:1;
85};
86
87/*
88 * The state of btrfs root
89 */
90enum {
91 /*
92 * btrfs_record_root_in_trans is a multi-step process, and it can race
93 * with the balancing code. But the race is very small, and only the
94 * first time the root is added to each transaction. So IN_TRANS_SETUP
95 * is used to tell us when more checks are required
96 */
97 BTRFS_ROOT_IN_TRANS_SETUP,
98
99 /*
100 * Set if tree blocks of this root can be shared by other roots.
101 * Only subvolume trees and their reloc trees have this bit set.
102 * Conflicts with TRACK_DIRTY bit.
103 *
104 * This affects two things:
105 *
106 * - How balance works
107 * For shareable roots, we need to use reloc tree and do path
108 * replacement for balance, and need various pre/post hooks for
109 * snapshot creation to handle them.
110 *
111 * While for non-shareable trees, we just simply do a tree search
112 * with COW.
113 *
114 * - How dirty roots are tracked
115 * For shareable roots, btrfs_record_root_in_trans() is needed to
116 * track them, while non-subvolume roots have TRACK_DIRTY bit, they
117 * don't need to set this manually.
118 */
119 BTRFS_ROOT_SHAREABLE,
120 BTRFS_ROOT_TRACK_DIRTY,
121 BTRFS_ROOT_IN_RADIX,
122 BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
123 BTRFS_ROOT_DEFRAG_RUNNING,
124 BTRFS_ROOT_FORCE_COW,
125 BTRFS_ROOT_MULTI_LOG_TASKS,
126 BTRFS_ROOT_DIRTY,
127 BTRFS_ROOT_DELETING,
128
129 /*
130 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
131 *
132 * Set for the subvolume tree owning the reloc tree.
133 */
134 BTRFS_ROOT_DEAD_RELOC_TREE,
135 /* Mark dead root stored on device whose cleanup needs to be resumed */
136 BTRFS_ROOT_DEAD_TREE,
137 /* The root has a log tree. Used for subvolume roots and the tree root. */
138 BTRFS_ROOT_HAS_LOG_TREE,
139 /* Qgroup flushing is in progress */
140 BTRFS_ROOT_QGROUP_FLUSHING,
141 /* We started the orphan cleanup for this root. */
142 BTRFS_ROOT_ORPHAN_CLEANUP,
143 /* This root has a drop operation that was started previously. */
144 BTRFS_ROOT_UNFINISHED_DROP,
145 /* This reloc root needs to have its buffers lockdep class reset. */
146 BTRFS_ROOT_RESET_LOCKDEP_CLASS,
147};
148
149/*
150 * Record swapped tree blocks of a subvolume tree for delayed subtree trace
151 * code. For detail check comment in fs/btrfs/qgroup.c.
152 */
153struct btrfs_qgroup_swapped_blocks {
154 spinlock_t lock;
155 /* RM_EMPTY_ROOT() of above blocks[] */
156 bool swapped;
157 struct rb_root blocks[BTRFS_MAX_LEVEL];
158};
159
160/*
161 * in ram representation of the tree. extent_root is used for all allocations
162 * and for the extent tree extent_root root.
163 */
164struct btrfs_root {
165 struct rb_node rb_node;
166
167 struct extent_buffer *node;
168
169 struct extent_buffer *commit_root;
170 struct btrfs_root *log_root;
171 struct btrfs_root *reloc_root;
172
173 unsigned long state;
174 struct btrfs_root_item root_item;
175 struct btrfs_key root_key;
176 struct btrfs_fs_info *fs_info;
177 struct extent_io_tree dirty_log_pages;
178
179 struct mutex objectid_mutex;
180
181 spinlock_t accounting_lock;
182 struct btrfs_block_rsv *block_rsv;
183
184 struct mutex log_mutex;
185 wait_queue_head_t log_writer_wait;
186 wait_queue_head_t log_commit_wait[2];
187 struct list_head log_ctxs[2];
188 /* Used only for log trees of subvolumes, not for the log root tree */
189 atomic_t log_writers;
190 atomic_t log_commit[2];
191 /* Used only for log trees of subvolumes, not for the log root tree */
192 atomic_t log_batch;
193 /*
194 * Protected by the 'log_mutex' lock but can be read without holding
195 * that lock to avoid unnecessary lock contention, in which case it
196 * should be read using btrfs_get_root_log_transid() except if it's a
197 * log tree in which case it can be directly accessed. Updates to this
198 * field should always use btrfs_set_root_log_transid(), except for log
199 * trees where the field can be updated directly.
200 */
201 int log_transid;
202 /* No matter the commit succeeds or not*/
203 int log_transid_committed;
204 /*
205 * Just be updated when the commit succeeds. Use
206 * btrfs_get_root_last_log_commit() and btrfs_set_root_last_log_commit()
207 * to access this field.
208 */
209 int last_log_commit;
210 pid_t log_start_pid;
211
212 u64 last_trans;
213
214 u64 free_objectid;
215
216 struct btrfs_key defrag_progress;
217 struct btrfs_key defrag_max;
218
219 /* The dirty list is only used by non-shareable roots */
220 struct list_head dirty_list;
221
222 struct list_head root_list;
223
224 spinlock_t inode_lock;
225 /* red-black tree that keeps track of in-memory inodes */
226 struct rb_root inode_tree;
227
228 /*
229 * Xarray that keeps track of delayed nodes of every inode, protected
230 * by @inode_lock.
231 */
232 struct xarray delayed_nodes;
233 /*
234 * right now this just gets used so that a root has its own devid
235 * for stat. It may be used for more later
236 */
237 dev_t anon_dev;
238
239 spinlock_t root_item_lock;
240 refcount_t refs;
241
242 struct mutex delalloc_mutex;
243 spinlock_t delalloc_lock;
244 /*
245 * all of the inodes that have delalloc bytes. It is possible for
246 * this list to be empty even when there is still dirty data=ordered
247 * extents waiting to finish IO.
248 */
249 struct list_head delalloc_inodes;
250 struct list_head delalloc_root;
251 u64 nr_delalloc_inodes;
252
253 struct mutex ordered_extent_mutex;
254 /*
255 * this is used by the balancing code to wait for all the pending
256 * ordered extents
257 */
258 spinlock_t ordered_extent_lock;
259
260 /*
261 * all of the data=ordered extents pending writeback
262 * these can span multiple transactions and basically include
263 * every dirty data page that isn't from nodatacow
264 */
265 struct list_head ordered_extents;
266 struct list_head ordered_root;
267 u64 nr_ordered_extents;
268
269 /*
270 * Not empty if this subvolume root has gone through tree block swap
271 * (relocation)
272 *
273 * Will be used by reloc_control::dirty_subvol_roots.
274 */
275 struct list_head reloc_dirty_list;
276
277 /*
278 * Number of currently running SEND ioctls to prevent
279 * manipulation with the read-only status via SUBVOL_SETFLAGS
280 */
281 int send_in_progress;
282 /*
283 * Number of currently running deduplication operations that have a
284 * destination inode belonging to this root. Protected by the lock
285 * root_item_lock.
286 */
287 int dedupe_in_progress;
288 /* For exclusion of snapshot creation and nocow writes */
289 struct btrfs_drew_lock snapshot_lock;
290
291 atomic_t snapshot_force_cow;
292
293 /* For qgroup metadata reserved space */
294 spinlock_t qgroup_meta_rsv_lock;
295 u64 qgroup_meta_rsv_pertrans;
296 u64 qgroup_meta_rsv_prealloc;
297 wait_queue_head_t qgroup_flush_wait;
298
299 /* Number of active swapfiles */
300 atomic_t nr_swapfiles;
301
302 /* Record pairs of swapped blocks for qgroup */
303 struct btrfs_qgroup_swapped_blocks swapped_blocks;
304
305 /* Used only by log trees, when logging csum items */
306 struct extent_io_tree log_csum_range;
307
308 /* Used in simple quotas, track root during relocation. */
309 u64 relocation_src_root;
310
311#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
312 u64 alloc_bytenr;
313#endif
314
315#ifdef CONFIG_BTRFS_DEBUG
316 struct list_head leak_list;
317#endif
318};
319
320static inline bool btrfs_root_readonly(const struct btrfs_root *root)
321{
322 /* Byte-swap the constant at compile time, root_item::flags is LE */
323 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
324}
325
326static inline bool btrfs_root_dead(const struct btrfs_root *root)
327{
328 /* Byte-swap the constant at compile time, root_item::flags is LE */
329 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
330}
331
332static inline u64 btrfs_root_id(const struct btrfs_root *root)
333{
334 return root->root_key.objectid;
335}
336
337static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
338{
339 return READ_ONCE(root->log_transid);
340}
341
342static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
343{
344 WRITE_ONCE(root->log_transid, log_transid);
345}
346
347static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
348{
349 return READ_ONCE(root->last_log_commit);
350}
351
352static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
353{
354 WRITE_ONCE(root->last_log_commit, commit_id);
355}
356
357/*
358 * Structure that conveys information about an extent that is going to replace
359 * all the extents in a file range.
360 */
361struct btrfs_replace_extent_info {
362 u64 disk_offset;
363 u64 disk_len;
364 u64 data_offset;
365 u64 data_len;
366 u64 file_offset;
367 /* Pointer to a file extent item of type regular or prealloc. */
368 char *extent_buf;
369 /*
370 * Set to true when attempting to replace a file range with a new extent
371 * described by this structure, set to false when attempting to clone an
372 * existing extent into a file range.
373 */
374 bool is_new_extent;
375 /* Indicate if we should update the inode's mtime and ctime. */
376 bool update_times;
377 /* Meaningful only if is_new_extent is true. */
378 int qgroup_reserved;
379 /*
380 * Meaningful only if is_new_extent is true.
381 * Used to track how many extent items we have already inserted in a
382 * subvolume tree that refer to the extent described by this structure,
383 * so that we know when to create a new delayed ref or update an existing
384 * one.
385 */
386 int insertions;
387};
388
389/* Arguments for btrfs_drop_extents() */
390struct btrfs_drop_extents_args {
391 /* Input parameters */
392
393 /*
394 * If NULL, btrfs_drop_extents() will allocate and free its own path.
395 * If 'replace_extent' is true, this must not be NULL. Also the path
396 * is always released except if 'replace_extent' is true and
397 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
398 * the path is kept locked.
399 */
400 struct btrfs_path *path;
401 /* Start offset of the range to drop extents from */
402 u64 start;
403 /* End (exclusive, last byte + 1) of the range to drop extents from */
404 u64 end;
405 /* If true drop all the extent maps in the range */
406 bool drop_cache;
407 /*
408 * If true it means we want to insert a new extent after dropping all
409 * the extents in the range. If this is true, the 'extent_item_size'
410 * parameter must be set as well and the 'extent_inserted' field will
411 * be set to true by btrfs_drop_extents() if it could insert the new
412 * extent.
413 * Note: when this is set to true the path must not be NULL.
414 */
415 bool replace_extent;
416 /*
417 * Used if 'replace_extent' is true. Size of the file extent item to
418 * insert after dropping all existing extents in the range
419 */
420 u32 extent_item_size;
421
422 /* Output parameters */
423
424 /*
425 * Set to the minimum between the input parameter 'end' and the end
426 * (exclusive, last byte + 1) of the last dropped extent. This is always
427 * set even if btrfs_drop_extents() returns an error.
428 */
429 u64 drop_end;
430 /*
431 * The number of allocated bytes found in the range. This can be smaller
432 * than the range's length when there are holes in the range.
433 */
434 u64 bytes_found;
435 /*
436 * Only set if 'replace_extent' is true. Set to true if we were able
437 * to insert a replacement extent after dropping all extents in the
438 * range, otherwise set to false by btrfs_drop_extents().
439 * Also, if btrfs_drop_extents() has set this to true it means it
440 * returned with the path locked, otherwise if it has set this to
441 * false it has returned with the path released.
442 */
443 bool extent_inserted;
444};
445
446struct btrfs_file_private {
447 void *filldir_buf;
448 u64 last_index;
449 struct extent_state *llseek_cached_state;
450};
451
452static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
453{
454 return info->nodesize - sizeof(struct btrfs_header);
455}
456
457static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
458{
459 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
460}
461
462static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
463{
464 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
465}
466
467static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
468{
469 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
470}
471
472#define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
473 ((bytes) >> (fs_info)->sectorsize_bits)
474
475static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
476{
477 return mapping_gfp_constraint(mapping, ~__GFP_FS);
478}
479
480void btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
481int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
482 u64 num_bytes, u64 *actual_bytes);
483int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
484
485/* ctree.c */
486int __init btrfs_ctree_init(void);
487void __cold btrfs_ctree_exit(void);
488
489int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
490 const struct btrfs_key *key, int *slot);
491
492int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
493
494#ifdef __LITTLE_ENDIAN
495
496/*
497 * Compare two keys, on little-endian the disk order is same as CPU order and
498 * we can avoid the conversion.
499 */
500static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
501 const struct btrfs_key *k2)
502{
503 const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
504
505 return btrfs_comp_cpu_keys(k1, k2);
506}
507
508#else
509
510/* Compare two keys in a memcmp fashion. */
511static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
512 const struct btrfs_key *k2)
513{
514 struct btrfs_key k1;
515
516 btrfs_disk_key_to_cpu(&k1, disk);
517
518 return btrfs_comp_cpu_keys(&k1, k2);
519}
520
521#endif
522
523int btrfs_previous_item(struct btrfs_root *root,
524 struct btrfs_path *path, u64 min_objectid,
525 int type);
526int btrfs_previous_extent_item(struct btrfs_root *root,
527 struct btrfs_path *path, u64 min_objectid);
528void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
529 struct btrfs_path *path,
530 const struct btrfs_key *new_key);
531struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
532int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
533 struct btrfs_key *key, int lowest_level,
534 u64 min_trans);
535int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
536 struct btrfs_path *path,
537 u64 min_trans);
538struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
539 int slot);
540
541int btrfs_cow_block(struct btrfs_trans_handle *trans,
542 struct btrfs_root *root, struct extent_buffer *buf,
543 struct extent_buffer *parent, int parent_slot,
544 struct extent_buffer **cow_ret,
545 enum btrfs_lock_nesting nest);
546int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
547 struct btrfs_root *root,
548 struct extent_buffer *buf,
549 struct extent_buffer *parent, int parent_slot,
550 struct extent_buffer **cow_ret,
551 u64 search_start, u64 empty_size,
552 enum btrfs_lock_nesting nest);
553int btrfs_copy_root(struct btrfs_trans_handle *trans,
554 struct btrfs_root *root,
555 struct extent_buffer *buf,
556 struct extent_buffer **cow_ret, u64 new_root_objectid);
557bool btrfs_block_can_be_shared(struct btrfs_trans_handle *trans,
558 struct btrfs_root *root,
559 struct extent_buffer *buf);
560int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
561 struct btrfs_path *path, int level, int slot);
562void btrfs_extend_item(struct btrfs_trans_handle *trans,
563 struct btrfs_path *path, u32 data_size);
564void btrfs_truncate_item(struct btrfs_trans_handle *trans,
565 struct btrfs_path *path, u32 new_size, int from_end);
566int btrfs_split_item(struct btrfs_trans_handle *trans,
567 struct btrfs_root *root,
568 struct btrfs_path *path,
569 const struct btrfs_key *new_key,
570 unsigned long split_offset);
571int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
572 struct btrfs_root *root,
573 struct btrfs_path *path,
574 const struct btrfs_key *new_key);
575int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
576 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
577int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
578 const struct btrfs_key *key, struct btrfs_path *p,
579 int ins_len, int cow);
580int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
581 struct btrfs_path *p, u64 time_seq);
582int btrfs_search_slot_for_read(struct btrfs_root *root,
583 const struct btrfs_key *key,
584 struct btrfs_path *p, int find_higher,
585 int return_any);
586void btrfs_release_path(struct btrfs_path *p);
587struct btrfs_path *btrfs_alloc_path(void);
588void btrfs_free_path(struct btrfs_path *p);
589
590int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
591 struct btrfs_path *path, int slot, int nr);
592static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
593 struct btrfs_root *root,
594 struct btrfs_path *path)
595{
596 return btrfs_del_items(trans, root, path, path->slots[0], 1);
597}
598
599/*
600 * Describes a batch of items to insert in a btree. This is used by
601 * btrfs_insert_empty_items().
602 */
603struct btrfs_item_batch {
604 /*
605 * Pointer to an array containing the keys of the items to insert (in
606 * sorted order).
607 */
608 const struct btrfs_key *keys;
609 /* Pointer to an array containing the data size for each item to insert. */
610 const u32 *data_sizes;
611 /*
612 * The sum of data sizes for all items. The caller can compute this while
613 * setting up the data_sizes array, so it ends up being more efficient
614 * than having btrfs_insert_empty_items() or setup_item_for_insert()
615 * doing it, as it would avoid an extra loop over a potentially large
616 * array, and in the case of setup_item_for_insert(), we would be doing
617 * it while holding a write lock on a leaf and often on upper level nodes
618 * too, unnecessarily increasing the size of a critical section.
619 */
620 u32 total_data_size;
621 /* Size of the keys and data_sizes arrays (number of items in the batch). */
622 int nr;
623};
624
625void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
626 struct btrfs_root *root,
627 struct btrfs_path *path,
628 const struct btrfs_key *key,
629 u32 data_size);
630int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
631 const struct btrfs_key *key, void *data, u32 data_size);
632int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
633 struct btrfs_root *root,
634 struct btrfs_path *path,
635 const struct btrfs_item_batch *batch);
636
637static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
638 struct btrfs_root *root,
639 struct btrfs_path *path,
640 const struct btrfs_key *key,
641 u32 data_size)
642{
643 struct btrfs_item_batch batch;
644
645 batch.keys = key;
646 batch.data_sizes = &data_size;
647 batch.total_data_size = data_size;
648 batch.nr = 1;
649
650 return btrfs_insert_empty_items(trans, root, path, &batch);
651}
652
653int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
654 u64 time_seq);
655
656int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
657 struct btrfs_path *path);
658
659int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
660 struct btrfs_path *path);
661
662/*
663 * Search in @root for a given @key, and store the slot found in @found_key.
664 *
665 * @root: The root node of the tree.
666 * @key: The key we are looking for.
667 * @found_key: Will hold the found item.
668 * @path: Holds the current slot/leaf.
669 * @iter_ret: Contains the value returned from btrfs_search_slot or
670 * btrfs_get_next_valid_item, whichever was executed last.
671 *
672 * The @iter_ret is an output variable that will contain the return value of
673 * btrfs_search_slot, if it encountered an error, or the value returned from
674 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
675 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
676 *
677 * It's recommended to use a separate variable for iter_ret and then use it to
678 * set the function return value so there's no confusion of the 0/1/errno
679 * values stemming from btrfs_search_slot.
680 */
681#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
682 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
683 (iter_ret) >= 0 && \
684 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
685 (path)->slots[0]++ \
686 )
687
688int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
689
690/*
691 * Search the tree again to find a leaf with greater keys.
692 *
693 * Returns 0 if it found something or 1 if there are no greater leaves.
694 * Returns < 0 on error.
695 */
696static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
697{
698 return btrfs_next_old_leaf(root, path, 0);
699}
700
701static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
702{
703 return btrfs_next_old_item(root, p, 0);
704}
705int btrfs_leaf_free_space(const struct extent_buffer *leaf);
706
707static inline int is_fstree(u64 rootid)
708{
709 if (rootid == BTRFS_FS_TREE_OBJECTID ||
710 ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
711 !btrfs_qgroup_level(rootid)))
712 return 1;
713 return 0;
714}
715
716static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
717{
718 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
719}
720
721u16 btrfs_csum_type_size(u16 type);
722int btrfs_super_csum_size(const struct btrfs_super_block *s);
723const char *btrfs_super_csum_name(u16 csum_type);
724const char *btrfs_super_csum_driver(u16 csum_type);
725size_t __attribute_const__ btrfs_get_num_csums(void);
726
727/*
728 * We use page status Private2 to indicate there is an ordered extent with
729 * unfinished IO.
730 *
731 * Rename the Private2 accessors to Ordered, to improve readability.
732 */
733#define PageOrdered(page) PagePrivate2(page)
734#define SetPageOrdered(page) SetPagePrivate2(page)
735#define ClearPageOrdered(page) ClearPagePrivate2(page)
736#define folio_test_ordered(folio) folio_test_private_2(folio)
737#define folio_set_ordered(folio) folio_set_private_2(folio)
738#define folio_clear_ordered(folio) folio_clear_private_2(folio)
739
740#endif
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/pagemap.h>
11#include <linux/spinlock.h>
12#include <linux/rbtree.h>
13#include <linux/mutex.h>
14#include <linux/wait.h>
15#include <linux/list.h>
16#include <linux/atomic.h>
17#include <linux/xarray.h>
18#include <linux/refcount.h>
19#include <uapi/linux/btrfs_tree.h>
20#include "locking.h"
21#include "fs.h"
22#include "accessors.h"
23#include "extent-io-tree.h"
24
25struct extent_buffer;
26struct btrfs_block_rsv;
27struct btrfs_trans_handle;
28struct btrfs_block_group;
29
30/* Read ahead values for struct btrfs_path.reada */
31enum {
32 READA_NONE,
33 READA_BACK,
34 READA_FORWARD,
35 /*
36 * Similar to READA_FORWARD but unlike it:
37 *
38 * 1) It will trigger readahead even for leaves that are not close to
39 * each other on disk;
40 * 2) It also triggers readahead for nodes;
41 * 3) During a search, even when a node or leaf is already in memory, it
42 * will still trigger readahead for other nodes and leaves that follow
43 * it.
44 *
45 * This is meant to be used only when we know we are iterating over the
46 * entire tree or a very large part of it.
47 */
48 READA_FORWARD_ALWAYS,
49};
50
51/*
52 * btrfs_paths remember the path taken from the root down to the leaf.
53 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
54 * to any other levels that are present.
55 *
56 * The slots array records the index of the item or block pointer
57 * used while walking the tree.
58 */
59struct btrfs_path {
60 struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
61 int slots[BTRFS_MAX_LEVEL];
62 /* if there is real range locking, this locks field will change */
63 u8 locks[BTRFS_MAX_LEVEL];
64 u8 reada;
65 /* keep some upper locks as we walk down */
66 u8 lowest_level;
67
68 /*
69 * set by btrfs_split_item, tells search_slot to keep all locks
70 * and to force calls to keep space in the nodes
71 */
72 unsigned int search_for_split:1;
73 unsigned int keep_locks:1;
74 unsigned int skip_locking:1;
75 unsigned int search_commit_root:1;
76 unsigned int need_commit_sem:1;
77 unsigned int skip_release_on_error:1;
78 /*
79 * Indicate that new item (btrfs_search_slot) is extending already
80 * existing item and ins_len contains only the data size and not item
81 * header (ie. sizeof(struct btrfs_item) is not included).
82 */
83 unsigned int search_for_extension:1;
84 /* Stop search if any locks need to be taken (for read) */
85 unsigned int nowait:1;
86};
87
88#define BTRFS_PATH_AUTO_FREE(path_name) \
89 struct btrfs_path *path_name __free(btrfs_free_path) = NULL
90
91/*
92 * The state of btrfs root
93 */
94enum {
95 /*
96 * btrfs_record_root_in_trans is a multi-step process, and it can race
97 * with the balancing code. But the race is very small, and only the
98 * first time the root is added to each transaction. So IN_TRANS_SETUP
99 * is used to tell us when more checks are required
100 */
101 BTRFS_ROOT_IN_TRANS_SETUP,
102
103 /*
104 * Set if tree blocks of this root can be shared by other roots.
105 * Only subvolume trees and their reloc trees have this bit set.
106 * Conflicts with TRACK_DIRTY bit.
107 *
108 * This affects two things:
109 *
110 * - How balance works
111 * For shareable roots, we need to use reloc tree and do path
112 * replacement for balance, and need various pre/post hooks for
113 * snapshot creation to handle them.
114 *
115 * While for non-shareable trees, we just simply do a tree search
116 * with COW.
117 *
118 * - How dirty roots are tracked
119 * For shareable roots, btrfs_record_root_in_trans() is needed to
120 * track them, while non-subvolume roots have TRACK_DIRTY bit, they
121 * don't need to set this manually.
122 */
123 BTRFS_ROOT_SHAREABLE,
124 BTRFS_ROOT_TRACK_DIRTY,
125 BTRFS_ROOT_IN_RADIX,
126 BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
127 BTRFS_ROOT_DEFRAG_RUNNING,
128 BTRFS_ROOT_FORCE_COW,
129 BTRFS_ROOT_MULTI_LOG_TASKS,
130 BTRFS_ROOT_DIRTY,
131 BTRFS_ROOT_DELETING,
132
133 /*
134 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
135 *
136 * Set for the subvolume tree owning the reloc tree.
137 */
138 BTRFS_ROOT_DEAD_RELOC_TREE,
139 /* Mark dead root stored on device whose cleanup needs to be resumed */
140 BTRFS_ROOT_DEAD_TREE,
141 /* The root has a log tree. Used for subvolume roots and the tree root. */
142 BTRFS_ROOT_HAS_LOG_TREE,
143 /* Qgroup flushing is in progress */
144 BTRFS_ROOT_QGROUP_FLUSHING,
145 /* We started the orphan cleanup for this root. */
146 BTRFS_ROOT_ORPHAN_CLEANUP,
147 /* This root has a drop operation that was started previously. */
148 BTRFS_ROOT_UNFINISHED_DROP,
149 /* This reloc root needs to have its buffers lockdep class reset. */
150 BTRFS_ROOT_RESET_LOCKDEP_CLASS,
151};
152
153/*
154 * Record swapped tree blocks of a subvolume tree for delayed subtree trace
155 * code. For detail check comment in fs/btrfs/qgroup.c.
156 */
157struct btrfs_qgroup_swapped_blocks {
158 spinlock_t lock;
159 /* RM_EMPTY_ROOT() of above blocks[] */
160 bool swapped;
161 struct rb_root blocks[BTRFS_MAX_LEVEL];
162};
163
164/*
165 * in ram representation of the tree. extent_root is used for all allocations
166 * and for the extent tree extent_root root.
167 */
168struct btrfs_root {
169 struct rb_node rb_node;
170
171 struct extent_buffer *node;
172
173 struct extent_buffer *commit_root;
174 struct btrfs_root *log_root;
175 struct btrfs_root *reloc_root;
176
177 unsigned long state;
178 struct btrfs_root_item root_item;
179 struct btrfs_key root_key;
180 struct btrfs_fs_info *fs_info;
181 struct extent_io_tree dirty_log_pages;
182
183 struct mutex objectid_mutex;
184
185 spinlock_t accounting_lock;
186 struct btrfs_block_rsv *block_rsv;
187
188 struct mutex log_mutex;
189 wait_queue_head_t log_writer_wait;
190 wait_queue_head_t log_commit_wait[2];
191 struct list_head log_ctxs[2];
192 /* Used only for log trees of subvolumes, not for the log root tree */
193 atomic_t log_writers;
194 atomic_t log_commit[2];
195 /* Used only for log trees of subvolumes, not for the log root tree */
196 atomic_t log_batch;
197 /*
198 * Protected by the 'log_mutex' lock but can be read without holding
199 * that lock to avoid unnecessary lock contention, in which case it
200 * should be read using btrfs_get_root_log_transid() except if it's a
201 * log tree in which case it can be directly accessed. Updates to this
202 * field should always use btrfs_set_root_log_transid(), except for log
203 * trees where the field can be updated directly.
204 */
205 int log_transid;
206 /* No matter the commit succeeds or not*/
207 int log_transid_committed;
208 /*
209 * Just be updated when the commit succeeds. Use
210 * btrfs_get_root_last_log_commit() and btrfs_set_root_last_log_commit()
211 * to access this field.
212 */
213 int last_log_commit;
214 pid_t log_start_pid;
215
216 u64 last_trans;
217
218 u64 free_objectid;
219
220 struct btrfs_key defrag_progress;
221 struct btrfs_key defrag_max;
222
223 /* The dirty list is only used by non-shareable roots */
224 struct list_head dirty_list;
225
226 struct list_head root_list;
227
228 /*
229 * Xarray that keeps track of in-memory inodes, protected by the lock
230 * @inode_lock.
231 */
232 struct xarray inodes;
233
234 /*
235 * Xarray that keeps track of delayed nodes of every inode, protected
236 * by @inode_lock.
237 */
238 struct xarray delayed_nodes;
239 /*
240 * right now this just gets used so that a root has its own devid
241 * for stat. It may be used for more later
242 */
243 dev_t anon_dev;
244
245 spinlock_t root_item_lock;
246 refcount_t refs;
247
248 struct mutex delalloc_mutex;
249 spinlock_t delalloc_lock;
250 /*
251 * all of the inodes that have delalloc bytes. It is possible for
252 * this list to be empty even when there is still dirty data=ordered
253 * extents waiting to finish IO.
254 */
255 struct list_head delalloc_inodes;
256 struct list_head delalloc_root;
257 u64 nr_delalloc_inodes;
258
259 struct mutex ordered_extent_mutex;
260 /*
261 * this is used by the balancing code to wait for all the pending
262 * ordered extents
263 */
264 spinlock_t ordered_extent_lock;
265
266 /*
267 * all of the data=ordered extents pending writeback
268 * these can span multiple transactions and basically include
269 * every dirty data page that isn't from nodatacow
270 */
271 struct list_head ordered_extents;
272 struct list_head ordered_root;
273 u64 nr_ordered_extents;
274
275 /*
276 * Not empty if this subvolume root has gone through tree block swap
277 * (relocation)
278 *
279 * Will be used by reloc_control::dirty_subvol_roots.
280 */
281 struct list_head reloc_dirty_list;
282
283 /*
284 * Number of currently running SEND ioctls to prevent
285 * manipulation with the read-only status via SUBVOL_SETFLAGS
286 */
287 int send_in_progress;
288 /*
289 * Number of currently running deduplication operations that have a
290 * destination inode belonging to this root. Protected by the lock
291 * root_item_lock.
292 */
293 int dedupe_in_progress;
294 /* For exclusion of snapshot creation and nocow writes */
295 struct btrfs_drew_lock snapshot_lock;
296
297 atomic_t snapshot_force_cow;
298
299 /* For qgroup metadata reserved space */
300 spinlock_t qgroup_meta_rsv_lock;
301 u64 qgroup_meta_rsv_pertrans;
302 u64 qgroup_meta_rsv_prealloc;
303 wait_queue_head_t qgroup_flush_wait;
304
305 /* Number of active swapfiles */
306 atomic_t nr_swapfiles;
307
308 /* Record pairs of swapped blocks for qgroup */
309 struct btrfs_qgroup_swapped_blocks swapped_blocks;
310
311 /* Used only by log trees, when logging csum items */
312 struct extent_io_tree log_csum_range;
313
314 /* Used in simple quotas, track root during relocation. */
315 u64 relocation_src_root;
316
317#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
318 u64 alloc_bytenr;
319#endif
320
321#ifdef CONFIG_BTRFS_DEBUG
322 struct list_head leak_list;
323#endif
324};
325
326static inline bool btrfs_root_readonly(const struct btrfs_root *root)
327{
328 /* Byte-swap the constant at compile time, root_item::flags is LE */
329 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
330}
331
332static inline bool btrfs_root_dead(const struct btrfs_root *root)
333{
334 /* Byte-swap the constant at compile time, root_item::flags is LE */
335 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
336}
337
338static inline u64 btrfs_root_id(const struct btrfs_root *root)
339{
340 return root->root_key.objectid;
341}
342
343static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
344{
345 return READ_ONCE(root->log_transid);
346}
347
348static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
349{
350 WRITE_ONCE(root->log_transid, log_transid);
351}
352
353static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
354{
355 return READ_ONCE(root->last_log_commit);
356}
357
358static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
359{
360 WRITE_ONCE(root->last_log_commit, commit_id);
361}
362
363static inline u64 btrfs_get_root_last_trans(const struct btrfs_root *root)
364{
365 return READ_ONCE(root->last_trans);
366}
367
368static inline void btrfs_set_root_last_trans(struct btrfs_root *root, u64 transid)
369{
370 WRITE_ONCE(root->last_trans, transid);
371}
372
373/*
374 * Return the generation this root started with.
375 *
376 * Every normal root that is created with root->root_key.offset set to it's
377 * originating generation. If it is a snapshot it is the generation when the
378 * snapshot was created.
379 *
380 * However for TREE_RELOC roots root_key.offset is the objectid of the owning
381 * tree root. Thankfully we copy the root item of the owning tree root, which
382 * has it's last_snapshot set to what we would have root_key.offset set to, so
383 * return that if this is a TREE_RELOC root.
384 */
385static inline u64 btrfs_root_origin_generation(const struct btrfs_root *root)
386{
387 if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID)
388 return btrfs_root_last_snapshot(&root->root_item);
389 return root->root_key.offset;
390}
391
392/*
393 * Structure that conveys information about an extent that is going to replace
394 * all the extents in a file range.
395 */
396struct btrfs_replace_extent_info {
397 u64 disk_offset;
398 u64 disk_len;
399 u64 data_offset;
400 u64 data_len;
401 u64 file_offset;
402 /* Pointer to a file extent item of type regular or prealloc. */
403 char *extent_buf;
404 /*
405 * Set to true when attempting to replace a file range with a new extent
406 * described by this structure, set to false when attempting to clone an
407 * existing extent into a file range.
408 */
409 bool is_new_extent;
410 /* Indicate if we should update the inode's mtime and ctime. */
411 bool update_times;
412 /* Meaningful only if is_new_extent is true. */
413 int qgroup_reserved;
414 /*
415 * Meaningful only if is_new_extent is true.
416 * Used to track how many extent items we have already inserted in a
417 * subvolume tree that refer to the extent described by this structure,
418 * so that we know when to create a new delayed ref or update an existing
419 * one.
420 */
421 int insertions;
422};
423
424/* Arguments for btrfs_drop_extents() */
425struct btrfs_drop_extents_args {
426 /* Input parameters */
427
428 /*
429 * If NULL, btrfs_drop_extents() will allocate and free its own path.
430 * If 'replace_extent' is true, this must not be NULL. Also the path
431 * is always released except if 'replace_extent' is true and
432 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
433 * the path is kept locked.
434 */
435 struct btrfs_path *path;
436 /* Start offset of the range to drop extents from */
437 u64 start;
438 /* End (exclusive, last byte + 1) of the range to drop extents from */
439 u64 end;
440 /* If true drop all the extent maps in the range */
441 bool drop_cache;
442 /*
443 * If true it means we want to insert a new extent after dropping all
444 * the extents in the range. If this is true, the 'extent_item_size'
445 * parameter must be set as well and the 'extent_inserted' field will
446 * be set to true by btrfs_drop_extents() if it could insert the new
447 * extent.
448 * Note: when this is set to true the path must not be NULL.
449 */
450 bool replace_extent;
451 /*
452 * Used if 'replace_extent' is true. Size of the file extent item to
453 * insert after dropping all existing extents in the range
454 */
455 u32 extent_item_size;
456
457 /* Output parameters */
458
459 /*
460 * Set to the minimum between the input parameter 'end' and the end
461 * (exclusive, last byte + 1) of the last dropped extent. This is always
462 * set even if btrfs_drop_extents() returns an error.
463 */
464 u64 drop_end;
465 /*
466 * The number of allocated bytes found in the range. This can be smaller
467 * than the range's length when there are holes in the range.
468 */
469 u64 bytes_found;
470 /*
471 * Only set if 'replace_extent' is true. Set to true if we were able
472 * to insert a replacement extent after dropping all extents in the
473 * range, otherwise set to false by btrfs_drop_extents().
474 * Also, if btrfs_drop_extents() has set this to true it means it
475 * returned with the path locked, otherwise if it has set this to
476 * false it has returned with the path released.
477 */
478 bool extent_inserted;
479};
480
481struct btrfs_file_private {
482 void *filldir_buf;
483 u64 last_index;
484 struct extent_state *llseek_cached_state;
485 /* Task that allocated this structure. */
486 struct task_struct *owner_task;
487};
488
489static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
490{
491 return info->nodesize - sizeof(struct btrfs_header);
492}
493
494static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
495{
496 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
497}
498
499static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
500{
501 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
502}
503
504static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
505{
506 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
507}
508
509#define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
510 ((bytes) >> (fs_info)->sectorsize_bits)
511
512static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
513{
514 return mapping_gfp_constraint(mapping, ~__GFP_FS);
515}
516
517void btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end);
518int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
519 u64 num_bytes, u64 *actual_bytes);
520int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
521
522/* ctree.c */
523int __init btrfs_ctree_init(void);
524void __cold btrfs_ctree_exit(void);
525
526int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
527 const struct btrfs_key *key, int *slot);
528
529int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
530
531#ifdef __LITTLE_ENDIAN
532
533/*
534 * Compare two keys, on little-endian the disk order is same as CPU order and
535 * we can avoid the conversion.
536 */
537static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
538 const struct btrfs_key *k2)
539{
540 const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
541
542 return btrfs_comp_cpu_keys(k1, k2);
543}
544
545#else
546
547/* Compare two keys in a memcmp fashion. */
548static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
549 const struct btrfs_key *k2)
550{
551 struct btrfs_key k1;
552
553 btrfs_disk_key_to_cpu(&k1, disk);
554
555 return btrfs_comp_cpu_keys(&k1, k2);
556}
557
558#endif
559
560int btrfs_previous_item(struct btrfs_root *root,
561 struct btrfs_path *path, u64 min_objectid,
562 int type);
563int btrfs_previous_extent_item(struct btrfs_root *root,
564 struct btrfs_path *path, u64 min_objectid);
565void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
566 const struct btrfs_path *path,
567 const struct btrfs_key *new_key);
568struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
569int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
570 struct btrfs_key *key, int lowest_level,
571 u64 min_trans);
572int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
573 struct btrfs_path *path,
574 u64 min_trans);
575struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
576 int slot);
577
578int btrfs_cow_block(struct btrfs_trans_handle *trans,
579 struct btrfs_root *root, struct extent_buffer *buf,
580 struct extent_buffer *parent, int parent_slot,
581 struct extent_buffer **cow_ret,
582 enum btrfs_lock_nesting nest);
583int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
584 struct btrfs_root *root,
585 struct extent_buffer *buf,
586 struct extent_buffer *parent, int parent_slot,
587 struct extent_buffer **cow_ret,
588 u64 search_start, u64 empty_size,
589 enum btrfs_lock_nesting nest);
590int btrfs_copy_root(struct btrfs_trans_handle *trans,
591 struct btrfs_root *root,
592 struct extent_buffer *buf,
593 struct extent_buffer **cow_ret, u64 new_root_objectid);
594bool btrfs_block_can_be_shared(struct btrfs_trans_handle *trans,
595 struct btrfs_root *root,
596 struct extent_buffer *buf);
597int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
598 struct btrfs_path *path, int level, int slot);
599void btrfs_extend_item(struct btrfs_trans_handle *trans,
600 const struct btrfs_path *path, u32 data_size);
601void btrfs_truncate_item(struct btrfs_trans_handle *trans,
602 const struct btrfs_path *path, u32 new_size, int from_end);
603int btrfs_split_item(struct btrfs_trans_handle *trans,
604 struct btrfs_root *root,
605 struct btrfs_path *path,
606 const struct btrfs_key *new_key,
607 unsigned long split_offset);
608int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
609 struct btrfs_root *root,
610 struct btrfs_path *path,
611 const struct btrfs_key *new_key);
612int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
613 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
614int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
615 const struct btrfs_key *key, struct btrfs_path *p,
616 int ins_len, int cow);
617int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
618 struct btrfs_path *p, u64 time_seq);
619int btrfs_search_slot_for_read(struct btrfs_root *root,
620 const struct btrfs_key *key,
621 struct btrfs_path *p, int find_higher,
622 int return_any);
623void btrfs_release_path(struct btrfs_path *p);
624struct btrfs_path *btrfs_alloc_path(void);
625void btrfs_free_path(struct btrfs_path *p);
626DEFINE_FREE(btrfs_free_path, struct btrfs_path *, btrfs_free_path(_T))
627
628int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
629 struct btrfs_path *path, int slot, int nr);
630static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
631 struct btrfs_root *root,
632 struct btrfs_path *path)
633{
634 return btrfs_del_items(trans, root, path, path->slots[0], 1);
635}
636
637/*
638 * Describes a batch of items to insert in a btree. This is used by
639 * btrfs_insert_empty_items().
640 */
641struct btrfs_item_batch {
642 /*
643 * Pointer to an array containing the keys of the items to insert (in
644 * sorted order).
645 */
646 const struct btrfs_key *keys;
647 /* Pointer to an array containing the data size for each item to insert. */
648 const u32 *data_sizes;
649 /*
650 * The sum of data sizes for all items. The caller can compute this while
651 * setting up the data_sizes array, so it ends up being more efficient
652 * than having btrfs_insert_empty_items() or setup_item_for_insert()
653 * doing it, as it would avoid an extra loop over a potentially large
654 * array, and in the case of setup_item_for_insert(), we would be doing
655 * it while holding a write lock on a leaf and often on upper level nodes
656 * too, unnecessarily increasing the size of a critical section.
657 */
658 u32 total_data_size;
659 /* Size of the keys and data_sizes arrays (number of items in the batch). */
660 int nr;
661};
662
663void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
664 struct btrfs_root *root,
665 struct btrfs_path *path,
666 const struct btrfs_key *key,
667 u32 data_size);
668int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
669 const struct btrfs_key *key, void *data, u32 data_size);
670int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
671 struct btrfs_root *root,
672 struct btrfs_path *path,
673 const struct btrfs_item_batch *batch);
674
675static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
676 struct btrfs_root *root,
677 struct btrfs_path *path,
678 const struct btrfs_key *key,
679 u32 data_size)
680{
681 struct btrfs_item_batch batch;
682
683 batch.keys = key;
684 batch.data_sizes = &data_size;
685 batch.total_data_size = data_size;
686 batch.nr = 1;
687
688 return btrfs_insert_empty_items(trans, root, path, &batch);
689}
690
691int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
692 u64 time_seq);
693
694int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
695 struct btrfs_path *path);
696
697int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
698 struct btrfs_path *path);
699
700/*
701 * Search in @root for a given @key, and store the slot found in @found_key.
702 *
703 * @root: The root node of the tree.
704 * @key: The key we are looking for.
705 * @found_key: Will hold the found item.
706 * @path: Holds the current slot/leaf.
707 * @iter_ret: Contains the value returned from btrfs_search_slot or
708 * btrfs_get_next_valid_item, whichever was executed last.
709 *
710 * The @iter_ret is an output variable that will contain the return value of
711 * btrfs_search_slot, if it encountered an error, or the value returned from
712 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
713 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
714 *
715 * It's recommended to use a separate variable for iter_ret and then use it to
716 * set the function return value so there's no confusion of the 0/1/errno
717 * values stemming from btrfs_search_slot.
718 */
719#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
720 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
721 (iter_ret) >= 0 && \
722 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
723 (path)->slots[0]++ \
724 )
725
726int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
727
728/*
729 * Search the tree again to find a leaf with greater keys.
730 *
731 * Returns 0 if it found something or 1 if there are no greater leaves.
732 * Returns < 0 on error.
733 */
734static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
735{
736 return btrfs_next_old_leaf(root, path, 0);
737}
738
739static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
740{
741 return btrfs_next_old_item(root, p, 0);
742}
743int btrfs_leaf_free_space(const struct extent_buffer *leaf);
744
745static inline int is_fstree(u64 rootid)
746{
747 if (rootid == BTRFS_FS_TREE_OBJECTID ||
748 ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
749 !btrfs_qgroup_level(rootid)))
750 return 1;
751 return 0;
752}
753
754static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
755{
756 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
757}
758
759u16 btrfs_csum_type_size(u16 type);
760int btrfs_super_csum_size(const struct btrfs_super_block *s);
761const char *btrfs_super_csum_name(u16 csum_type);
762const char *btrfs_super_csum_driver(u16 csum_type);
763size_t __attribute_const__ btrfs_get_num_csums(void);
764
765/*
766 * We use folio flag owner_2 to indicate there is an ordered extent with
767 * unfinished IO.
768 */
769#define folio_test_ordered(folio) folio_test_owner_2(folio)
770#define folio_set_ordered(folio) folio_set_owner_2(folio)
771#define folio_clear_ordered(folio) folio_clear_owner_2(folio)
772
773#endif