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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 "locking.h"
11#include "fs.h"
12#include "accessors.h"
13
14struct btrfs_trans_handle;
15struct btrfs_transaction;
16struct btrfs_pending_snapshot;
17struct btrfs_delayed_ref_root;
18struct btrfs_space_info;
19struct btrfs_block_group;
20struct btrfs_ordered_sum;
21struct btrfs_ref;
22struct btrfs_bio;
23struct btrfs_ioctl_encoded_io_args;
24struct btrfs_device;
25struct btrfs_fs_devices;
26struct btrfs_balance_control;
27struct btrfs_delayed_root;
28struct reloc_control;
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/*
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 spinlock_t inode_lock;
226 /* red-black tree that keeps track of in-memory inodes */
227 struct rb_root inode_tree;
228
229 /*
230 * Xarray that keeps track of delayed nodes of every inode, protected
231 * by @inode_lock.
232 */
233 struct xarray delayed_nodes;
234 /*
235 * right now this just gets used so that a root has its own devid
236 * for stat. It may be used for more later
237 */
238 dev_t anon_dev;
239
240 spinlock_t root_item_lock;
241 refcount_t refs;
242
243 struct mutex delalloc_mutex;
244 spinlock_t delalloc_lock;
245 /*
246 * all of the inodes that have delalloc bytes. It is possible for
247 * this list to be empty even when there is still dirty data=ordered
248 * extents waiting to finish IO.
249 */
250 struct list_head delalloc_inodes;
251 struct list_head delalloc_root;
252 u64 nr_delalloc_inodes;
253
254 struct mutex ordered_extent_mutex;
255 /*
256 * this is used by the balancing code to wait for all the pending
257 * ordered extents
258 */
259 spinlock_t ordered_extent_lock;
260
261 /*
262 * all of the data=ordered extents pending writeback
263 * these can span multiple transactions and basically include
264 * every dirty data page that isn't from nodatacow
265 */
266 struct list_head ordered_extents;
267 struct list_head ordered_root;
268 u64 nr_ordered_extents;
269
270 /*
271 * Not empty if this subvolume root has gone through tree block swap
272 * (relocation)
273 *
274 * Will be used by reloc_control::dirty_subvol_roots.
275 */
276 struct list_head reloc_dirty_list;
277
278 /*
279 * Number of currently running SEND ioctls to prevent
280 * manipulation with the read-only status via SUBVOL_SETFLAGS
281 */
282 int send_in_progress;
283 /*
284 * Number of currently running deduplication operations that have a
285 * destination inode belonging to this root. Protected by the lock
286 * root_item_lock.
287 */
288 int dedupe_in_progress;
289 /* For exclusion of snapshot creation and nocow writes */
290 struct btrfs_drew_lock snapshot_lock;
291
292 atomic_t snapshot_force_cow;
293
294 /* For qgroup metadata reserved space */
295 spinlock_t qgroup_meta_rsv_lock;
296 u64 qgroup_meta_rsv_pertrans;
297 u64 qgroup_meta_rsv_prealloc;
298 wait_queue_head_t qgroup_flush_wait;
299
300 /* Number of active swapfiles */
301 atomic_t nr_swapfiles;
302
303 /* Record pairs of swapped blocks for qgroup */
304 struct btrfs_qgroup_swapped_blocks swapped_blocks;
305
306 /* Used only by log trees, when logging csum items */
307 struct extent_io_tree log_csum_range;
308
309 /* Used in simple quotas, track root during relocation. */
310 u64 relocation_src_root;
311
312#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
313 u64 alloc_bytenr;
314#endif
315
316#ifdef CONFIG_BTRFS_DEBUG
317 struct list_head leak_list;
318#endif
319};
320
321static inline bool btrfs_root_readonly(const struct btrfs_root *root)
322{
323 /* Byte-swap the constant at compile time, root_item::flags is LE */
324 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
325}
326
327static inline bool btrfs_root_dead(const struct btrfs_root *root)
328{
329 /* Byte-swap the constant at compile time, root_item::flags is LE */
330 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
331}
332
333static inline u64 btrfs_root_id(const struct btrfs_root *root)
334{
335 return root->root_key.objectid;
336}
337
338static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
339{
340 return READ_ONCE(root->log_transid);
341}
342
343static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
344{
345 WRITE_ONCE(root->log_transid, log_transid);
346}
347
348static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
349{
350 return READ_ONCE(root->last_log_commit);
351}
352
353static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
354{
355 WRITE_ONCE(root->last_log_commit, commit_id);
356}
357
358/*
359 * Structure that conveys information about an extent that is going to replace
360 * all the extents in a file range.
361 */
362struct btrfs_replace_extent_info {
363 u64 disk_offset;
364 u64 disk_len;
365 u64 data_offset;
366 u64 data_len;
367 u64 file_offset;
368 /* Pointer to a file extent item of type regular or prealloc. */
369 char *extent_buf;
370 /*
371 * Set to true when attempting to replace a file range with a new extent
372 * described by this structure, set to false when attempting to clone an
373 * existing extent into a file range.
374 */
375 bool is_new_extent;
376 /* Indicate if we should update the inode's mtime and ctime. */
377 bool update_times;
378 /* Meaningful only if is_new_extent is true. */
379 int qgroup_reserved;
380 /*
381 * Meaningful only if is_new_extent is true.
382 * Used to track how many extent items we have already inserted in a
383 * subvolume tree that refer to the extent described by this structure,
384 * so that we know when to create a new delayed ref or update an existing
385 * one.
386 */
387 int insertions;
388};
389
390/* Arguments for btrfs_drop_extents() */
391struct btrfs_drop_extents_args {
392 /* Input parameters */
393
394 /*
395 * If NULL, btrfs_drop_extents() will allocate and free its own path.
396 * If 'replace_extent' is true, this must not be NULL. Also the path
397 * is always released except if 'replace_extent' is true and
398 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
399 * the path is kept locked.
400 */
401 struct btrfs_path *path;
402 /* Start offset of the range to drop extents from */
403 u64 start;
404 /* End (exclusive, last byte + 1) of the range to drop extents from */
405 u64 end;
406 /* If true drop all the extent maps in the range */
407 bool drop_cache;
408 /*
409 * If true it means we want to insert a new extent after dropping all
410 * the extents in the range. If this is true, the 'extent_item_size'
411 * parameter must be set as well and the 'extent_inserted' field will
412 * be set to true by btrfs_drop_extents() if it could insert the new
413 * extent.
414 * Note: when this is set to true the path must not be NULL.
415 */
416 bool replace_extent;
417 /*
418 * Used if 'replace_extent' is true. Size of the file extent item to
419 * insert after dropping all existing extents in the range
420 */
421 u32 extent_item_size;
422
423 /* Output parameters */
424
425 /*
426 * Set to the minimum between the input parameter 'end' and the end
427 * (exclusive, last byte + 1) of the last dropped extent. This is always
428 * set even if btrfs_drop_extents() returns an error.
429 */
430 u64 drop_end;
431 /*
432 * The number of allocated bytes found in the range. This can be smaller
433 * than the range's length when there are holes in the range.
434 */
435 u64 bytes_found;
436 /*
437 * Only set if 'replace_extent' is true. Set to true if we were able
438 * to insert a replacement extent after dropping all extents in the
439 * range, otherwise set to false by btrfs_drop_extents().
440 * Also, if btrfs_drop_extents() has set this to true it means it
441 * returned with the path locked, otherwise if it has set this to
442 * false it has returned with the path released.
443 */
444 bool extent_inserted;
445};
446
447struct btrfs_file_private {
448 void *filldir_buf;
449 u64 last_index;
450 struct extent_state *llseek_cached_state;
451};
452
453static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
454{
455 return info->nodesize - sizeof(struct btrfs_header);
456}
457
458static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
459{
460 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
461}
462
463static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
464{
465 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
466}
467
468static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
469{
470 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
471}
472
473#define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
474 ((bytes) >> (fs_info)->sectorsize_bits)
475
476static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
477{
478 return mapping_gfp_constraint(mapping, ~__GFP_FS);
479}
480
481int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
482 u64 start, u64 end);
483int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
484 u64 num_bytes, u64 *actual_bytes);
485int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
486
487/* ctree.c */
488int __init btrfs_ctree_init(void);
489void __cold btrfs_ctree_exit(void);
490
491int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
492 const struct btrfs_key *key, int *slot);
493
494int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
495
496#ifdef __LITTLE_ENDIAN
497
498/*
499 * Compare two keys, on little-endian the disk order is same as CPU order and
500 * we can avoid the conversion.
501 */
502static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
503 const struct btrfs_key *k2)
504{
505 const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
506
507 return btrfs_comp_cpu_keys(k1, k2);
508}
509
510#else
511
512/* Compare two keys in a memcmp fashion. */
513static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
514 const struct btrfs_key *k2)
515{
516 struct btrfs_key k1;
517
518 btrfs_disk_key_to_cpu(&k1, disk);
519
520 return btrfs_comp_cpu_keys(&k1, k2);
521}
522
523#endif
524
525int btrfs_previous_item(struct btrfs_root *root,
526 struct btrfs_path *path, u64 min_objectid,
527 int type);
528int btrfs_previous_extent_item(struct btrfs_root *root,
529 struct btrfs_path *path, u64 min_objectid);
530void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
531 struct btrfs_path *path,
532 const struct btrfs_key *new_key);
533struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
534int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
535 struct btrfs_key *key, int lowest_level,
536 u64 min_trans);
537int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
538 struct btrfs_path *path,
539 u64 min_trans);
540struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
541 int slot);
542
543int btrfs_cow_block(struct btrfs_trans_handle *trans,
544 struct btrfs_root *root, struct extent_buffer *buf,
545 struct extent_buffer *parent, int parent_slot,
546 struct extent_buffer **cow_ret,
547 enum btrfs_lock_nesting nest);
548int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
549 struct btrfs_root *root,
550 struct extent_buffer *buf,
551 struct extent_buffer *parent, int parent_slot,
552 struct extent_buffer **cow_ret,
553 u64 search_start, u64 empty_size,
554 enum btrfs_lock_nesting nest);
555int btrfs_copy_root(struct btrfs_trans_handle *trans,
556 struct btrfs_root *root,
557 struct extent_buffer *buf,
558 struct extent_buffer **cow_ret, u64 new_root_objectid);
559bool btrfs_block_can_be_shared(struct btrfs_trans_handle *trans,
560 struct btrfs_root *root,
561 struct extent_buffer *buf);
562int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
563 struct btrfs_path *path, int level, int slot);
564void btrfs_extend_item(struct btrfs_trans_handle *trans,
565 struct btrfs_path *path, u32 data_size);
566void btrfs_truncate_item(struct btrfs_trans_handle *trans,
567 struct btrfs_path *path, u32 new_size, int from_end);
568int btrfs_split_item(struct btrfs_trans_handle *trans,
569 struct btrfs_root *root,
570 struct btrfs_path *path,
571 const struct btrfs_key *new_key,
572 unsigned long split_offset);
573int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
574 struct btrfs_root *root,
575 struct btrfs_path *path,
576 const struct btrfs_key *new_key);
577int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
578 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
579int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
580 const struct btrfs_key *key, struct btrfs_path *p,
581 int ins_len, int cow);
582int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
583 struct btrfs_path *p, u64 time_seq);
584int btrfs_search_slot_for_read(struct btrfs_root *root,
585 const struct btrfs_key *key,
586 struct btrfs_path *p, int find_higher,
587 int return_any);
588void btrfs_release_path(struct btrfs_path *p);
589struct btrfs_path *btrfs_alloc_path(void);
590void btrfs_free_path(struct btrfs_path *p);
591
592int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
593 struct btrfs_path *path, int slot, int nr);
594static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
595 struct btrfs_root *root,
596 struct btrfs_path *path)
597{
598 return btrfs_del_items(trans, root, path, path->slots[0], 1);
599}
600
601/*
602 * Describes a batch of items to insert in a btree. This is used by
603 * btrfs_insert_empty_items().
604 */
605struct btrfs_item_batch {
606 /*
607 * Pointer to an array containing the keys of the items to insert (in
608 * sorted order).
609 */
610 const struct btrfs_key *keys;
611 /* Pointer to an array containing the data size for each item to insert. */
612 const u32 *data_sizes;
613 /*
614 * The sum of data sizes for all items. The caller can compute this while
615 * setting up the data_sizes array, so it ends up being more efficient
616 * than having btrfs_insert_empty_items() or setup_item_for_insert()
617 * doing it, as it would avoid an extra loop over a potentially large
618 * array, and in the case of setup_item_for_insert(), we would be doing
619 * it while holding a write lock on a leaf and often on upper level nodes
620 * too, unnecessarily increasing the size of a critical section.
621 */
622 u32 total_data_size;
623 /* Size of the keys and data_sizes arrays (number of items in the batch). */
624 int nr;
625};
626
627void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
628 struct btrfs_root *root,
629 struct btrfs_path *path,
630 const struct btrfs_key *key,
631 u32 data_size);
632int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
633 const struct btrfs_key *key, void *data, u32 data_size);
634int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
635 struct btrfs_root *root,
636 struct btrfs_path *path,
637 const struct btrfs_item_batch *batch);
638
639static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
640 struct btrfs_root *root,
641 struct btrfs_path *path,
642 const struct btrfs_key *key,
643 u32 data_size)
644{
645 struct btrfs_item_batch batch;
646
647 batch.keys = key;
648 batch.data_sizes = &data_size;
649 batch.total_data_size = data_size;
650 batch.nr = 1;
651
652 return btrfs_insert_empty_items(trans, root, path, &batch);
653}
654
655int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
656 u64 time_seq);
657
658int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
659 struct btrfs_path *path);
660
661int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
662 struct btrfs_path *path);
663
664/*
665 * Search in @root for a given @key, and store the slot found in @found_key.
666 *
667 * @root: The root node of the tree.
668 * @key: The key we are looking for.
669 * @found_key: Will hold the found item.
670 * @path: Holds the current slot/leaf.
671 * @iter_ret: Contains the value returned from btrfs_search_slot or
672 * btrfs_get_next_valid_item, whichever was executed last.
673 *
674 * The @iter_ret is an output variable that will contain the return value of
675 * btrfs_search_slot, if it encountered an error, or the value returned from
676 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
677 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
678 *
679 * It's recommended to use a separate variable for iter_ret and then use it to
680 * set the function return value so there's no confusion of the 0/1/errno
681 * values stemming from btrfs_search_slot.
682 */
683#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
684 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
685 (iter_ret) >= 0 && \
686 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
687 (path)->slots[0]++ \
688 )
689
690int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
691
692/*
693 * Search the tree again to find a leaf with greater keys.
694 *
695 * Returns 0 if it found something or 1 if there are no greater leaves.
696 * Returns < 0 on error.
697 */
698static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
699{
700 return btrfs_next_old_leaf(root, path, 0);
701}
702
703static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
704{
705 return btrfs_next_old_item(root, p, 0);
706}
707int btrfs_leaf_free_space(const struct extent_buffer *leaf);
708
709static inline int is_fstree(u64 rootid)
710{
711 if (rootid == BTRFS_FS_TREE_OBJECTID ||
712 ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
713 !btrfs_qgroup_level(rootid)))
714 return 1;
715 return 0;
716}
717
718static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
719{
720 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
721}
722
723u16 btrfs_csum_type_size(u16 type);
724int btrfs_super_csum_size(const struct btrfs_super_block *s);
725const char *btrfs_super_csum_name(u16 csum_type);
726const char *btrfs_super_csum_driver(u16 csum_type);
727size_t __attribute_const__ btrfs_get_num_csums(void);
728
729/*
730 * We use page status Private2 to indicate there is an ordered extent with
731 * unfinished IO.
732 *
733 * Rename the Private2 accessors to Ordered, to improve readability.
734 */
735#define PageOrdered(page) PagePrivate2(page)
736#define SetPageOrdered(page) SetPagePrivate2(page)
737#define ClearPageOrdered(page) ClearPagePrivate2(page)
738#define folio_test_ordered(folio) folio_test_private_2(folio)
739#define folio_set_ordered(folio) folio_set_private_2(folio)
740#define folio_clear_ordered(folio) folio_clear_private_2(folio)
741
742#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/mm.h>
10#include <linux/sched/signal.h>
11#include <linux/highmem.h>
12#include <linux/fs.h>
13#include <linux/rwsem.h>
14#include <linux/semaphore.h>
15#include <linux/completion.h>
16#include <linux/backing-dev.h>
17#include <linux/wait.h>
18#include <linux/slab.h>
19#include <trace/events/btrfs.h>
20#include <asm/unaligned.h>
21#include <linux/pagemap.h>
22#include <linux/btrfs.h>
23#include <linux/btrfs_tree.h>
24#include <linux/workqueue.h>
25#include <linux/security.h>
26#include <linux/sizes.h>
27#include <linux/dynamic_debug.h>
28#include <linux/refcount.h>
29#include <linux/crc32c.h>
30#include <linux/iomap.h>
31#include <linux/fscrypt.h>
32#include "extent-io-tree.h"
33#include "extent_io.h"
34#include "extent_map.h"
35#include "async-thread.h"
36#include "block-rsv.h"
37#include "locking.h"
38#include "misc.h"
39#include "fs.h"
40
41struct btrfs_trans_handle;
42struct btrfs_transaction;
43struct btrfs_pending_snapshot;
44struct btrfs_delayed_ref_root;
45struct btrfs_space_info;
46struct btrfs_block_group;
47struct btrfs_ordered_sum;
48struct btrfs_ref;
49struct btrfs_bio;
50struct btrfs_ioctl_encoded_io_args;
51struct btrfs_device;
52struct btrfs_fs_devices;
53struct btrfs_balance_control;
54struct btrfs_delayed_root;
55struct reloc_control;
56
57/* Read ahead values for struct btrfs_path.reada */
58enum {
59 READA_NONE,
60 READA_BACK,
61 READA_FORWARD,
62 /*
63 * Similar to READA_FORWARD but unlike it:
64 *
65 * 1) It will trigger readahead even for leaves that are not close to
66 * each other on disk;
67 * 2) It also triggers readahead for nodes;
68 * 3) During a search, even when a node or leaf is already in memory, it
69 * will still trigger readahead for other nodes and leaves that follow
70 * it.
71 *
72 * This is meant to be used only when we know we are iterating over the
73 * entire tree or a very large part of it.
74 */
75 READA_FORWARD_ALWAYS,
76};
77
78/*
79 * btrfs_paths remember the path taken from the root down to the leaf.
80 * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point
81 * to any other levels that are present.
82 *
83 * The slots array records the index of the item or block pointer
84 * used while walking the tree.
85 */
86struct btrfs_path {
87 struct extent_buffer *nodes[BTRFS_MAX_LEVEL];
88 int slots[BTRFS_MAX_LEVEL];
89 /* if there is real range locking, this locks field will change */
90 u8 locks[BTRFS_MAX_LEVEL];
91 u8 reada;
92 /* keep some upper locks as we walk down */
93 u8 lowest_level;
94
95 /*
96 * set by btrfs_split_item, tells search_slot to keep all locks
97 * and to force calls to keep space in the nodes
98 */
99 unsigned int search_for_split:1;
100 unsigned int keep_locks:1;
101 unsigned int skip_locking:1;
102 unsigned int search_commit_root:1;
103 unsigned int need_commit_sem:1;
104 unsigned int skip_release_on_error:1;
105 /*
106 * Indicate that new item (btrfs_search_slot) is extending already
107 * existing item and ins_len contains only the data size and not item
108 * header (ie. sizeof(struct btrfs_item) is not included).
109 */
110 unsigned int search_for_extension:1;
111 /* Stop search if any locks need to be taken (for read) */
112 unsigned int nowait:1;
113};
114
115/*
116 * The state of btrfs root
117 */
118enum {
119 /*
120 * btrfs_record_root_in_trans is a multi-step process, and it can race
121 * with the balancing code. But the race is very small, and only the
122 * first time the root is added to each transaction. So IN_TRANS_SETUP
123 * is used to tell us when more checks are required
124 */
125 BTRFS_ROOT_IN_TRANS_SETUP,
126
127 /*
128 * Set if tree blocks of this root can be shared by other roots.
129 * Only subvolume trees and their reloc trees have this bit set.
130 * Conflicts with TRACK_DIRTY bit.
131 *
132 * This affects two things:
133 *
134 * - How balance works
135 * For shareable roots, we need to use reloc tree and do path
136 * replacement for balance, and need various pre/post hooks for
137 * snapshot creation to handle them.
138 *
139 * While for non-shareable trees, we just simply do a tree search
140 * with COW.
141 *
142 * - How dirty roots are tracked
143 * For shareable roots, btrfs_record_root_in_trans() is needed to
144 * track them, while non-subvolume roots have TRACK_DIRTY bit, they
145 * don't need to set this manually.
146 */
147 BTRFS_ROOT_SHAREABLE,
148 BTRFS_ROOT_TRACK_DIRTY,
149 BTRFS_ROOT_IN_RADIX,
150 BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
151 BTRFS_ROOT_DEFRAG_RUNNING,
152 BTRFS_ROOT_FORCE_COW,
153 BTRFS_ROOT_MULTI_LOG_TASKS,
154 BTRFS_ROOT_DIRTY,
155 BTRFS_ROOT_DELETING,
156
157 /*
158 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
159 *
160 * Set for the subvolume tree owning the reloc tree.
161 */
162 BTRFS_ROOT_DEAD_RELOC_TREE,
163 /* Mark dead root stored on device whose cleanup needs to be resumed */
164 BTRFS_ROOT_DEAD_TREE,
165 /* The root has a log tree. Used for subvolume roots and the tree root. */
166 BTRFS_ROOT_HAS_LOG_TREE,
167 /* Qgroup flushing is in progress */
168 BTRFS_ROOT_QGROUP_FLUSHING,
169 /* We started the orphan cleanup for this root. */
170 BTRFS_ROOT_ORPHAN_CLEANUP,
171 /* This root has a drop operation that was started previously. */
172 BTRFS_ROOT_UNFINISHED_DROP,
173 /* This reloc root needs to have its buffers lockdep class reset. */
174 BTRFS_ROOT_RESET_LOCKDEP_CLASS,
175};
176
177/*
178 * Record swapped tree blocks of a subvolume tree for delayed subtree trace
179 * code. For detail check comment in fs/btrfs/qgroup.c.
180 */
181struct btrfs_qgroup_swapped_blocks {
182 spinlock_t lock;
183 /* RM_EMPTY_ROOT() of above blocks[] */
184 bool swapped;
185 struct rb_root blocks[BTRFS_MAX_LEVEL];
186};
187
188/*
189 * in ram representation of the tree. extent_root is used for all allocations
190 * and for the extent tree extent_root root.
191 */
192struct btrfs_root {
193 struct rb_node rb_node;
194
195 struct extent_buffer *node;
196
197 struct extent_buffer *commit_root;
198 struct btrfs_root *log_root;
199 struct btrfs_root *reloc_root;
200
201 unsigned long state;
202 struct btrfs_root_item root_item;
203 struct btrfs_key root_key;
204 struct btrfs_fs_info *fs_info;
205 struct extent_io_tree dirty_log_pages;
206
207 struct mutex objectid_mutex;
208
209 spinlock_t accounting_lock;
210 struct btrfs_block_rsv *block_rsv;
211
212 struct mutex log_mutex;
213 wait_queue_head_t log_writer_wait;
214 wait_queue_head_t log_commit_wait[2];
215 struct list_head log_ctxs[2];
216 /* Used only for log trees of subvolumes, not for the log root tree */
217 atomic_t log_writers;
218 atomic_t log_commit[2];
219 /* Used only for log trees of subvolumes, not for the log root tree */
220 atomic_t log_batch;
221 int log_transid;
222 /* No matter the commit succeeds or not*/
223 int log_transid_committed;
224 /* Just be updated when the commit succeeds. */
225 int last_log_commit;
226 pid_t log_start_pid;
227
228 u64 last_trans;
229
230 u32 type;
231
232 u64 free_objectid;
233
234 struct btrfs_key defrag_progress;
235 struct btrfs_key defrag_max;
236
237 /* The dirty list is only used by non-shareable roots */
238 struct list_head dirty_list;
239
240 struct list_head root_list;
241
242 spinlock_t log_extents_lock[2];
243 struct list_head logged_list[2];
244
245 spinlock_t inode_lock;
246 /* red-black tree that keeps track of in-memory inodes */
247 struct rb_root inode_tree;
248
249 /*
250 * radix tree that keeps track of delayed nodes of every inode,
251 * protected by inode_lock
252 */
253 struct radix_tree_root delayed_nodes_tree;
254 /*
255 * right now this just gets used so that a root has its own devid
256 * for stat. It may be used for more later
257 */
258 dev_t anon_dev;
259
260 spinlock_t root_item_lock;
261 refcount_t refs;
262
263 struct mutex delalloc_mutex;
264 spinlock_t delalloc_lock;
265 /*
266 * all of the inodes that have delalloc bytes. It is possible for
267 * this list to be empty even when there is still dirty data=ordered
268 * extents waiting to finish IO.
269 */
270 struct list_head delalloc_inodes;
271 struct list_head delalloc_root;
272 u64 nr_delalloc_inodes;
273
274 struct mutex ordered_extent_mutex;
275 /*
276 * this is used by the balancing code to wait for all the pending
277 * ordered extents
278 */
279 spinlock_t ordered_extent_lock;
280
281 /*
282 * all of the data=ordered extents pending writeback
283 * these can span multiple transactions and basically include
284 * every dirty data page that isn't from nodatacow
285 */
286 struct list_head ordered_extents;
287 struct list_head ordered_root;
288 u64 nr_ordered_extents;
289
290 /*
291 * Not empty if this subvolume root has gone through tree block swap
292 * (relocation)
293 *
294 * Will be used by reloc_control::dirty_subvol_roots.
295 */
296 struct list_head reloc_dirty_list;
297
298 /*
299 * Number of currently running SEND ioctls to prevent
300 * manipulation with the read-only status via SUBVOL_SETFLAGS
301 */
302 int send_in_progress;
303 /*
304 * Number of currently running deduplication operations that have a
305 * destination inode belonging to this root. Protected by the lock
306 * root_item_lock.
307 */
308 int dedupe_in_progress;
309 /* For exclusion of snapshot creation and nocow writes */
310 struct btrfs_drew_lock snapshot_lock;
311
312 atomic_t snapshot_force_cow;
313
314 /* For qgroup metadata reserved space */
315 spinlock_t qgroup_meta_rsv_lock;
316 u64 qgroup_meta_rsv_pertrans;
317 u64 qgroup_meta_rsv_prealloc;
318 wait_queue_head_t qgroup_flush_wait;
319
320 /* Number of active swapfiles */
321 atomic_t nr_swapfiles;
322
323 /* Record pairs of swapped blocks for qgroup */
324 struct btrfs_qgroup_swapped_blocks swapped_blocks;
325
326 /* Used only by log trees, when logging csum items */
327 struct extent_io_tree log_csum_range;
328
329#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
330 u64 alloc_bytenr;
331#endif
332
333#ifdef CONFIG_BTRFS_DEBUG
334 struct list_head leak_list;
335#endif
336};
337
338static inline bool btrfs_root_readonly(const struct btrfs_root *root)
339{
340 /* Byte-swap the constant at compile time, root_item::flags is LE */
341 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0;
342}
343
344static inline bool btrfs_root_dead(const struct btrfs_root *root)
345{
346 /* Byte-swap the constant at compile time, root_item::flags is LE */
347 return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
348}
349
350static inline u64 btrfs_root_id(const struct btrfs_root *root)
351{
352 return root->root_key.objectid;
353}
354
355/*
356 * Structure that conveys information about an extent that is going to replace
357 * all the extents in a file range.
358 */
359struct btrfs_replace_extent_info {
360 u64 disk_offset;
361 u64 disk_len;
362 u64 data_offset;
363 u64 data_len;
364 u64 file_offset;
365 /* Pointer to a file extent item of type regular or prealloc. */
366 char *extent_buf;
367 /*
368 * Set to true when attempting to replace a file range with a new extent
369 * described by this structure, set to false when attempting to clone an
370 * existing extent into a file range.
371 */
372 bool is_new_extent;
373 /* Indicate if we should update the inode's mtime and ctime. */
374 bool update_times;
375 /* Meaningful only if is_new_extent is true. */
376 int qgroup_reserved;
377 /*
378 * Meaningful only if is_new_extent is true.
379 * Used to track how many extent items we have already inserted in a
380 * subvolume tree that refer to the extent described by this structure,
381 * so that we know when to create a new delayed ref or update an existing
382 * one.
383 */
384 int insertions;
385};
386
387/* Arguments for btrfs_drop_extents() */
388struct btrfs_drop_extents_args {
389 /* Input parameters */
390
391 /*
392 * If NULL, btrfs_drop_extents() will allocate and free its own path.
393 * If 'replace_extent' is true, this must not be NULL. Also the path
394 * is always released except if 'replace_extent' is true and
395 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
396 * the path is kept locked.
397 */
398 struct btrfs_path *path;
399 /* Start offset of the range to drop extents from */
400 u64 start;
401 /* End (exclusive, last byte + 1) of the range to drop extents from */
402 u64 end;
403 /* If true drop all the extent maps in the range */
404 bool drop_cache;
405 /*
406 * If true it means we want to insert a new extent after dropping all
407 * the extents in the range. If this is true, the 'extent_item_size'
408 * parameter must be set as well and the 'extent_inserted' field will
409 * be set to true by btrfs_drop_extents() if it could insert the new
410 * extent.
411 * Note: when this is set to true the path must not be NULL.
412 */
413 bool replace_extent;
414 /*
415 * Used if 'replace_extent' is true. Size of the file extent item to
416 * insert after dropping all existing extents in the range
417 */
418 u32 extent_item_size;
419
420 /* Output parameters */
421
422 /*
423 * Set to the minimum between the input parameter 'end' and the end
424 * (exclusive, last byte + 1) of the last dropped extent. This is always
425 * set even if btrfs_drop_extents() returns an error.
426 */
427 u64 drop_end;
428 /*
429 * The number of allocated bytes found in the range. This can be smaller
430 * than the range's length when there are holes in the range.
431 */
432 u64 bytes_found;
433 /*
434 * Only set if 'replace_extent' is true. Set to true if we were able
435 * to insert a replacement extent after dropping all extents in the
436 * range, otherwise set to false by btrfs_drop_extents().
437 * Also, if btrfs_drop_extents() has set this to true it means it
438 * returned with the path locked, otherwise if it has set this to
439 * false it has returned with the path released.
440 */
441 bool extent_inserted;
442};
443
444struct btrfs_file_private {
445 void *filldir_buf;
446 struct extent_state *llseek_cached_state;
447};
448
449static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
450{
451 return info->nodesize - sizeof(struct btrfs_header);
452}
453
454static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
455{
456 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
457}
458
459static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
460{
461 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
462}
463
464static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
465{
466 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
467}
468
469#define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
470 ((bytes) >> (fs_info)->sectorsize_bits)
471
472static inline u32 btrfs_crc32c(u32 crc, const void *address, unsigned length)
473{
474 return crc32c(crc, address, length);
475}
476
477static inline void btrfs_crc32c_final(u32 crc, u8 *result)
478{
479 put_unaligned_le32(~crc, result);
480}
481
482static inline u64 btrfs_name_hash(const char *name, int len)
483{
484 return crc32c((u32)~1, name, len);
485}
486
487/*
488 * Figure the key offset of an extended inode ref
489 */
490static inline u64 btrfs_extref_hash(u64 parent_objectid, const char *name,
491 int len)
492{
493 return (u64) crc32c(parent_objectid, name, len);
494}
495
496static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
497{
498 return mapping_gfp_constraint(mapping, ~__GFP_FS);
499}
500
501int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
502 u64 start, u64 end);
503int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
504 u64 num_bytes, u64 *actual_bytes);
505int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
506
507/* ctree.c */
508int __init btrfs_ctree_init(void);
509void __cold btrfs_ctree_exit(void);
510int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
511 int *slot);
512int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
513int btrfs_previous_item(struct btrfs_root *root,
514 struct btrfs_path *path, u64 min_objectid,
515 int type);
516int btrfs_previous_extent_item(struct btrfs_root *root,
517 struct btrfs_path *path, u64 min_objectid);
518void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info,
519 struct btrfs_path *path,
520 const struct btrfs_key *new_key);
521struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
522int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
523 struct btrfs_key *key, int lowest_level,
524 u64 min_trans);
525int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
526 struct btrfs_path *path,
527 u64 min_trans);
528struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
529 int slot);
530
531int btrfs_cow_block(struct btrfs_trans_handle *trans,
532 struct btrfs_root *root, struct extent_buffer *buf,
533 struct extent_buffer *parent, int parent_slot,
534 struct extent_buffer **cow_ret,
535 enum btrfs_lock_nesting nest);
536int btrfs_copy_root(struct btrfs_trans_handle *trans,
537 struct btrfs_root *root,
538 struct extent_buffer *buf,
539 struct extent_buffer **cow_ret, u64 new_root_objectid);
540int btrfs_block_can_be_shared(struct btrfs_root *root,
541 struct extent_buffer *buf);
542void btrfs_extend_item(struct btrfs_path *path, u32 data_size);
543void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end);
544int btrfs_split_item(struct btrfs_trans_handle *trans,
545 struct btrfs_root *root,
546 struct btrfs_path *path,
547 const struct btrfs_key *new_key,
548 unsigned long split_offset);
549int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
550 struct btrfs_root *root,
551 struct btrfs_path *path,
552 const struct btrfs_key *new_key);
553int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
554 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
555int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
556 const struct btrfs_key *key, struct btrfs_path *p,
557 int ins_len, int cow);
558int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
559 struct btrfs_path *p, u64 time_seq);
560int btrfs_search_slot_for_read(struct btrfs_root *root,
561 const struct btrfs_key *key,
562 struct btrfs_path *p, int find_higher,
563 int return_any);
564int btrfs_realloc_node(struct btrfs_trans_handle *trans,
565 struct btrfs_root *root, struct extent_buffer *parent,
566 int start_slot, u64 *last_ret,
567 struct btrfs_key *progress);
568void btrfs_release_path(struct btrfs_path *p);
569struct btrfs_path *btrfs_alloc_path(void);
570void btrfs_free_path(struct btrfs_path *p);
571
572int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
573 struct btrfs_path *path, int slot, int nr);
574static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
575 struct btrfs_root *root,
576 struct btrfs_path *path)
577{
578 return btrfs_del_items(trans, root, path, path->slots[0], 1);
579}
580
581/*
582 * Describes a batch of items to insert in a btree. This is used by
583 * btrfs_insert_empty_items().
584 */
585struct btrfs_item_batch {
586 /*
587 * Pointer to an array containing the keys of the items to insert (in
588 * sorted order).
589 */
590 const struct btrfs_key *keys;
591 /* Pointer to an array containing the data size for each item to insert. */
592 const u32 *data_sizes;
593 /*
594 * The sum of data sizes for all items. The caller can compute this while
595 * setting up the data_sizes array, so it ends up being more efficient
596 * than having btrfs_insert_empty_items() or setup_item_for_insert()
597 * doing it, as it would avoid an extra loop over a potentially large
598 * array, and in the case of setup_item_for_insert(), we would be doing
599 * it while holding a write lock on a leaf and often on upper level nodes
600 * too, unnecessarily increasing the size of a critical section.
601 */
602 u32 total_data_size;
603 /* Size of the keys and data_sizes arrays (number of items in the batch). */
604 int nr;
605};
606
607void btrfs_setup_item_for_insert(struct btrfs_root *root,
608 struct btrfs_path *path,
609 const struct btrfs_key *key,
610 u32 data_size);
611int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
612 const struct btrfs_key *key, void *data, u32 data_size);
613int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
614 struct btrfs_root *root,
615 struct btrfs_path *path,
616 const struct btrfs_item_batch *batch);
617
618static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
619 struct btrfs_root *root,
620 struct btrfs_path *path,
621 const struct btrfs_key *key,
622 u32 data_size)
623{
624 struct btrfs_item_batch batch;
625
626 batch.keys = key;
627 batch.data_sizes = &data_size;
628 batch.total_data_size = data_size;
629 batch.nr = 1;
630
631 return btrfs_insert_empty_items(trans, root, path, &batch);
632}
633
634int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path);
635int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
636 u64 time_seq);
637
638int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
639 struct btrfs_path *path);
640
641int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
642 struct btrfs_path *path);
643
644/*
645 * Search in @root for a given @key, and store the slot found in @found_key.
646 *
647 * @root: The root node of the tree.
648 * @key: The key we are looking for.
649 * @found_key: Will hold the found item.
650 * @path: Holds the current slot/leaf.
651 * @iter_ret: Contains the value returned from btrfs_search_slot or
652 * btrfs_get_next_valid_item, whichever was executed last.
653 *
654 * The @iter_ret is an output variable that will contain the return value of
655 * btrfs_search_slot, if it encountered an error, or the value returned from
656 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
657 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
658 *
659 * It's recommended to use a separate variable for iter_ret and then use it to
660 * set the function return value so there's no confusion of the 0/1/errno
661 * values stemming from btrfs_search_slot.
662 */
663#define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
664 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
665 (iter_ret) >= 0 && \
666 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
667 (path)->slots[0]++ \
668 )
669
670int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
671
672/*
673 * Search the tree again to find a leaf with greater keys.
674 *
675 * Returns 0 if it found something or 1 if there are no greater leaves.
676 * Returns < 0 on error.
677 */
678static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
679{
680 return btrfs_next_old_leaf(root, path, 0);
681}
682
683static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
684{
685 return btrfs_next_old_item(root, p, 0);
686}
687int btrfs_leaf_free_space(struct extent_buffer *leaf);
688
689static inline int is_fstree(u64 rootid)
690{
691 if (rootid == BTRFS_FS_TREE_OBJECTID ||
692 ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
693 !btrfs_qgroup_level(rootid)))
694 return 1;
695 return 0;
696}
697
698static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
699{
700 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
701}
702
703int btrfs_super_csum_size(const struct btrfs_super_block *s);
704const char *btrfs_super_csum_name(u16 csum_type);
705const char *btrfs_super_csum_driver(u16 csum_type);
706size_t __attribute_const__ btrfs_get_num_csums(void);
707
708/*
709 * We use page status Private2 to indicate there is an ordered extent with
710 * unfinished IO.
711 *
712 * Rename the Private2 accessors to Ordered, to improve readability.
713 */
714#define PageOrdered(page) PagePrivate2(page)
715#define SetPageOrdered(page) SetPagePrivate2(page)
716#define ClearPageOrdered(page) ClearPagePrivate2(page)
717#define folio_test_ordered(folio) folio_test_private_2(folio)
718#define folio_set_ordered(folio) folio_set_private_2(folio)
719#define folio_clear_ordered(folio) folio_clear_private_2(folio)
720
721#endif