1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2007 Oracle. All rights reserved.
9 #include <linux/pagemap.h>
12 #include "accessors.h"
14 struct btrfs_trans_handle;
15 struct btrfs_transaction;
16 struct btrfs_pending_snapshot;
17 struct btrfs_delayed_ref_root;
18 struct btrfs_space_info;
19 struct btrfs_block_group;
20 struct btrfs_ordered_sum;
23 struct btrfs_ioctl_encoded_io_args;
25 struct btrfs_fs_devices;
26 struct btrfs_balance_control;
27 struct btrfs_delayed_root;
30 /* Read ahead values for struct btrfs_path.reada */
36 * Similar to READA_FORWARD but unlike it:
38 * 1) It will trigger readahead even for leaves that are not close to
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
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.
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.
56 * The slots array records the index of the item or block pointer
57 * used while walking the tree.
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];
65 /* keep some upper locks as we walk down */
69 * set by btrfs_split_item, tells search_slot to keep all locks
70 * and to force calls to keep space in the nodes
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;
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).
83 unsigned int search_for_extension:1;
84 /* Stop search if any locks need to be taken (for read) */
85 unsigned int nowait:1;
89 * The state of btrfs root
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
98 BTRFS_ROOT_IN_TRANS_SETUP,
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.
105 * This affects two things:
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.
112 * While for non-shareable trees, we just simply do a tree search
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.
120 BTRFS_ROOT_SHAREABLE,
121 BTRFS_ROOT_TRACK_DIRTY,
123 BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
124 BTRFS_ROOT_DEFRAG_RUNNING,
125 BTRFS_ROOT_FORCE_COW,
126 BTRFS_ROOT_MULTI_LOG_TASKS,
131 * Reloc tree is orphan, only kept here for qgroup delayed subtree scan
133 * Set for the subvolume tree owning the reloc tree.
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,
151 * Record swapped tree blocks of a subvolume tree for delayed subtree trace
152 * code. For detail check comment in fs/btrfs/qgroup.c.
154 struct btrfs_qgroup_swapped_blocks {
156 /* RM_EMPTY_ROOT() of above blocks[] */
158 struct rb_root blocks[BTRFS_MAX_LEVEL];
162 * in ram representation of the tree. extent_root is used for all allocations
163 * and for the extent tree extent_root root.
166 struct rb_node rb_node;
168 struct extent_buffer *node;
170 struct extent_buffer *commit_root;
171 struct btrfs_root *log_root;
172 struct btrfs_root *reloc_root;
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;
180 struct mutex objectid_mutex;
182 spinlock_t accounting_lock;
183 struct btrfs_block_rsv *block_rsv;
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 */
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.
203 /* No matter the commit succeeds or not*/
204 int log_transid_committed;
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.
219 struct btrfs_key defrag_progress;
220 struct btrfs_key defrag_max;
222 /* The dirty list is only used by non-shareable roots */
223 struct list_head dirty_list;
225 struct list_head root_list;
227 spinlock_t log_extents_lock[2];
228 struct list_head logged_list[2];
230 spinlock_t inode_lock;
231 /* red-black tree that keeps track of in-memory inodes */
232 struct rb_root inode_tree;
235 * radix tree that keeps track of delayed nodes of every inode,
236 * protected by inode_lock
238 struct radix_tree_root delayed_nodes_tree;
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
245 spinlock_t root_item_lock;
248 struct mutex delalloc_mutex;
249 spinlock_t delalloc_lock;
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.
255 struct list_head delalloc_inodes;
256 struct list_head delalloc_root;
257 u64 nr_delalloc_inodes;
259 struct mutex ordered_extent_mutex;
261 * this is used by the balancing code to wait for all the pending
264 spinlock_t ordered_extent_lock;
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
271 struct list_head ordered_extents;
272 struct list_head ordered_root;
273 u64 nr_ordered_extents;
276 * Not empty if this subvolume root has gone through tree block swap
279 * Will be used by reloc_control::dirty_subvol_roots.
281 struct list_head reloc_dirty_list;
284 * Number of currently running SEND ioctls to prevent
285 * manipulation with the read-only status via SUBVOL_SETFLAGS
287 int send_in_progress;
289 * Number of currently running deduplication operations that have a
290 * destination inode belonging to this root. Protected by the lock
293 int dedupe_in_progress;
294 /* For exclusion of snapshot creation and nocow writes */
295 struct btrfs_drew_lock snapshot_lock;
297 atomic_t snapshot_force_cow;
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;
305 /* Number of active swapfiles */
306 atomic_t nr_swapfiles;
308 /* Record pairs of swapped blocks for qgroup */
309 struct btrfs_qgroup_swapped_blocks swapped_blocks;
311 /* Used only by log trees, when logging csum items */
312 struct extent_io_tree log_csum_range;
314 /* Used in simple quotas, track root during relocation. */
315 u64 relocation_src_root;
317 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
321 #ifdef CONFIG_BTRFS_DEBUG
322 struct list_head leak_list;
326 static inline bool btrfs_root_readonly(const struct btrfs_root *root)
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;
332 static inline bool btrfs_root_dead(const struct btrfs_root *root)
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;
338 static inline u64 btrfs_root_id(const struct btrfs_root *root)
340 return root->root_key.objectid;
343 static inline int btrfs_get_root_log_transid(const struct btrfs_root *root)
345 return READ_ONCE(root->log_transid);
348 static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid)
350 WRITE_ONCE(root->log_transid, log_transid);
353 static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root)
355 return READ_ONCE(root->last_log_commit);
358 static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id)
360 WRITE_ONCE(root->last_log_commit, commit_id);
364 * Structure that conveys information about an extent that is going to replace
365 * all the extents in a file range.
367 struct btrfs_replace_extent_info {
373 /* Pointer to a file extent item of type regular or prealloc. */
376 * Set to true when attempting to replace a file range with a new extent
377 * described by this structure, set to false when attempting to clone an
378 * existing extent into a file range.
381 /* Indicate if we should update the inode's mtime and ctime. */
383 /* Meaningful only if is_new_extent is true. */
386 * Meaningful only if is_new_extent is true.
387 * Used to track how many extent items we have already inserted in a
388 * subvolume tree that refer to the extent described by this structure,
389 * so that we know when to create a new delayed ref or update an existing
395 /* Arguments for btrfs_drop_extents() */
396 struct btrfs_drop_extents_args {
397 /* Input parameters */
400 * If NULL, btrfs_drop_extents() will allocate and free its own path.
401 * If 'replace_extent' is true, this must not be NULL. Also the path
402 * is always released except if 'replace_extent' is true and
403 * btrfs_drop_extents() sets 'extent_inserted' to true, in which case
404 * the path is kept locked.
406 struct btrfs_path *path;
407 /* Start offset of the range to drop extents from */
409 /* End (exclusive, last byte + 1) of the range to drop extents from */
411 /* If true drop all the extent maps in the range */
414 * If true it means we want to insert a new extent after dropping all
415 * the extents in the range. If this is true, the 'extent_item_size'
416 * parameter must be set as well and the 'extent_inserted' field will
417 * be set to true by btrfs_drop_extents() if it could insert the new
419 * Note: when this is set to true the path must not be NULL.
423 * Used if 'replace_extent' is true. Size of the file extent item to
424 * insert after dropping all existing extents in the range
426 u32 extent_item_size;
428 /* Output parameters */
431 * Set to the minimum between the input parameter 'end' and the end
432 * (exclusive, last byte + 1) of the last dropped extent. This is always
433 * set even if btrfs_drop_extents() returns an error.
437 * The number of allocated bytes found in the range. This can be smaller
438 * than the range's length when there are holes in the range.
442 * Only set if 'replace_extent' is true. Set to true if we were able
443 * to insert a replacement extent after dropping all extents in the
444 * range, otherwise set to false by btrfs_drop_extents().
445 * Also, if btrfs_drop_extents() has set this to true it means it
446 * returned with the path locked, otherwise if it has set this to
447 * false it has returned with the path released.
449 bool extent_inserted;
452 struct btrfs_file_private {
455 struct extent_state *llseek_cached_state;
458 static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info)
460 return info->nodesize - sizeof(struct btrfs_header);
463 static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info)
465 return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item);
468 static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info)
470 return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr);
473 static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info)
475 return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item);
478 #define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
479 ((bytes) >> (fs_info)->sectorsize_bits)
481 static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping)
483 return mapping_gfp_constraint(mapping, ~__GFP_FS);
486 int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info,
488 int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr,
489 u64 num_bytes, u64 *actual_bytes);
490 int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range);
493 int __init btrfs_ctree_init(void);
494 void __cold btrfs_ctree_exit(void);
496 int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
497 const struct btrfs_key *key, int *slot);
499 int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);
501 #ifdef __LITTLE_ENDIAN
504 * Compare two keys, on little-endian the disk order is same as CPU order and
505 * we can avoid the conversion.
507 static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key,
508 const struct btrfs_key *k2)
510 const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key;
512 return btrfs_comp_cpu_keys(k1, k2);
517 /* Compare two keys in a memcmp fashion. */
518 static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk,
519 const struct btrfs_key *k2)
523 btrfs_disk_key_to_cpu(&k1, disk);
525 return btrfs_comp_cpu_keys(&k1, k2);
530 int btrfs_previous_item(struct btrfs_root *root,
531 struct btrfs_path *path, u64 min_objectid,
533 int btrfs_previous_extent_item(struct btrfs_root *root,
534 struct btrfs_path *path, u64 min_objectid);
535 void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans,
536 struct btrfs_path *path,
537 const struct btrfs_key *new_key);
538 struct extent_buffer *btrfs_root_node(struct btrfs_root *root);
539 int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path,
540 struct btrfs_key *key, int lowest_level,
542 int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
543 struct btrfs_path *path,
545 struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
548 int btrfs_cow_block(struct btrfs_trans_handle *trans,
549 struct btrfs_root *root, struct extent_buffer *buf,
550 struct extent_buffer *parent, int parent_slot,
551 struct extent_buffer **cow_ret,
552 enum btrfs_lock_nesting nest);
553 int btrfs_force_cow_block(struct btrfs_trans_handle *trans,
554 struct btrfs_root *root,
555 struct extent_buffer *buf,
556 struct extent_buffer *parent, int parent_slot,
557 struct extent_buffer **cow_ret,
558 u64 search_start, u64 empty_size,
559 enum btrfs_lock_nesting nest);
560 int btrfs_copy_root(struct btrfs_trans_handle *trans,
561 struct btrfs_root *root,
562 struct extent_buffer *buf,
563 struct extent_buffer **cow_ret, u64 new_root_objectid);
564 int btrfs_block_can_be_shared(struct btrfs_trans_handle *trans,
565 struct btrfs_root *root,
566 struct extent_buffer *buf);
567 int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
568 struct btrfs_path *path, int level, int slot);
569 void btrfs_extend_item(struct btrfs_trans_handle *trans,
570 struct btrfs_path *path, u32 data_size);
571 void btrfs_truncate_item(struct btrfs_trans_handle *trans,
572 struct btrfs_path *path, u32 new_size, int from_end);
573 int btrfs_split_item(struct btrfs_trans_handle *trans,
574 struct btrfs_root *root,
575 struct btrfs_path *path,
576 const struct btrfs_key *new_key,
577 unsigned long split_offset);
578 int btrfs_duplicate_item(struct btrfs_trans_handle *trans,
579 struct btrfs_root *root,
580 struct btrfs_path *path,
581 const struct btrfs_key *new_key);
582 int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path,
583 u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key);
584 int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root,
585 const struct btrfs_key *key, struct btrfs_path *p,
586 int ins_len, int cow);
587 int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key,
588 struct btrfs_path *p, u64 time_seq);
589 int btrfs_search_slot_for_read(struct btrfs_root *root,
590 const struct btrfs_key *key,
591 struct btrfs_path *p, int find_higher,
593 void btrfs_release_path(struct btrfs_path *p);
594 struct btrfs_path *btrfs_alloc_path(void);
595 void btrfs_free_path(struct btrfs_path *p);
597 int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root,
598 struct btrfs_path *path, int slot, int nr);
599 static inline int btrfs_del_item(struct btrfs_trans_handle *trans,
600 struct btrfs_root *root,
601 struct btrfs_path *path)
603 return btrfs_del_items(trans, root, path, path->slots[0], 1);
607 * Describes a batch of items to insert in a btree. This is used by
608 * btrfs_insert_empty_items().
610 struct btrfs_item_batch {
612 * Pointer to an array containing the keys of the items to insert (in
615 const struct btrfs_key *keys;
616 /* Pointer to an array containing the data size for each item to insert. */
617 const u32 *data_sizes;
619 * The sum of data sizes for all items. The caller can compute this while
620 * setting up the data_sizes array, so it ends up being more efficient
621 * than having btrfs_insert_empty_items() or setup_item_for_insert()
622 * doing it, as it would avoid an extra loop over a potentially large
623 * array, and in the case of setup_item_for_insert(), we would be doing
624 * it while holding a write lock on a leaf and often on upper level nodes
625 * too, unnecessarily increasing the size of a critical section.
628 /* Size of the keys and data_sizes arrays (number of items in the batch). */
632 void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans,
633 struct btrfs_root *root,
634 struct btrfs_path *path,
635 const struct btrfs_key *key,
637 int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root,
638 const struct btrfs_key *key, void *data, u32 data_size);
639 int btrfs_insert_empty_items(struct btrfs_trans_handle *trans,
640 struct btrfs_root *root,
641 struct btrfs_path *path,
642 const struct btrfs_item_batch *batch);
644 static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans,
645 struct btrfs_root *root,
646 struct btrfs_path *path,
647 const struct btrfs_key *key,
650 struct btrfs_item_batch batch;
653 batch.data_sizes = &data_size;
654 batch.total_data_size = data_size;
657 return btrfs_insert_empty_items(trans, root, path, &batch);
660 int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path,
663 int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key,
664 struct btrfs_path *path);
666 int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key,
667 struct btrfs_path *path);
670 * Search in @root for a given @key, and store the slot found in @found_key.
672 * @root: The root node of the tree.
673 * @key: The key we are looking for.
674 * @found_key: Will hold the found item.
675 * @path: Holds the current slot/leaf.
676 * @iter_ret: Contains the value returned from btrfs_search_slot or
677 * btrfs_get_next_valid_item, whichever was executed last.
679 * The @iter_ret is an output variable that will contain the return value of
680 * btrfs_search_slot, if it encountered an error, or the value returned from
681 * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid
682 * slot was found, 1 if there were no more leaves, and <0 if there was an error.
684 * It's recommended to use a separate variable for iter_ret and then use it to
685 * set the function return value so there's no confusion of the 0/1/errno
686 * values stemming from btrfs_search_slot.
688 #define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \
689 for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \
691 (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \
695 int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq);
698 * Search the tree again to find a leaf with greater keys.
700 * Returns 0 if it found something or 1 if there are no greater leaves.
701 * Returns < 0 on error.
703 static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
705 return btrfs_next_old_leaf(root, path, 0);
708 static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p)
710 return btrfs_next_old_item(root, p, 0);
712 int btrfs_leaf_free_space(const struct extent_buffer *leaf);
714 static inline int is_fstree(u64 rootid)
716 if (rootid == BTRFS_FS_TREE_OBJECTID ||
717 ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID &&
718 !btrfs_qgroup_level(rootid)))
723 static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root)
725 return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID;
728 u16 btrfs_csum_type_size(u16 type);
729 int btrfs_super_csum_size(const struct btrfs_super_block *s);
730 const char *btrfs_super_csum_name(u16 csum_type);
731 const char *btrfs_super_csum_driver(u16 csum_type);
732 size_t __attribute_const__ btrfs_get_num_csums(void);
735 * We use page status Private2 to indicate there is an ordered extent with
738 * Rename the Private2 accessors to Ordered, to improve readability.
740 #define PageOrdered(page) PagePrivate2(page)
741 #define SetPageOrdered(page) SetPagePrivate2(page)
742 #define ClearPageOrdered(page) ClearPagePrivate2(page)
743 #define folio_test_ordered(folio) folio_test_private_2(folio)
744 #define folio_set_ordered(folio) folio_set_private_2(folio)
745 #define folio_clear_ordered(folio) folio_clear_private_2(folio)