/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2007 Oracle. All rights reserved. */ #ifndef BTRFS_CTREE_H #define BTRFS_CTREE_H #include "linux/cleanup.h" #include #include #include #include #include #include #include #include #include #include #include "locking.h" #include "fs.h" #include "accessors.h" #include "extent-io-tree.h" struct extent_buffer; struct btrfs_block_rsv; struct btrfs_trans_handle; struct btrfs_block_group; /* Read ahead values for struct btrfs_path.reada */ enum { READA_NONE, READA_BACK, READA_FORWARD, /* * Similar to READA_FORWARD but unlike it: * * 1) It will trigger readahead even for leaves that are not close to * each other on disk; * 2) It also triggers readahead for nodes; * 3) During a search, even when a node or leaf is already in memory, it * will still trigger readahead for other nodes and leaves that follow * it. * * This is meant to be used only when we know we are iterating over the * entire tree or a very large part of it. */ READA_FORWARD_ALWAYS, }; /* * btrfs_paths remember the path taken from the root down to the leaf. * level 0 is always the leaf, and nodes[1...BTRFS_MAX_LEVEL] will point * to any other levels that are present. * * The slots array records the index of the item or block pointer * used while walking the tree. */ struct btrfs_path { struct extent_buffer *nodes[BTRFS_MAX_LEVEL]; int slots[BTRFS_MAX_LEVEL]; /* if there is real range locking, this locks field will change */ u8 locks[BTRFS_MAX_LEVEL]; u8 reada; /* keep some upper locks as we walk down */ u8 lowest_level; /* * set by btrfs_split_item, tells search_slot to keep all locks * and to force calls to keep space in the nodes */ unsigned int search_for_split:1; unsigned int keep_locks:1; unsigned int skip_locking:1; unsigned int search_commit_root:1; unsigned int need_commit_sem:1; unsigned int skip_release_on_error:1; /* * Indicate that new item (btrfs_search_slot) is extending already * existing item and ins_len contains only the data size and not item * header (ie. sizeof(struct btrfs_item) is not included). */ unsigned int search_for_extension:1; /* Stop search if any locks need to be taken (for read) */ unsigned int nowait:1; }; #define BTRFS_PATH_AUTO_FREE(path_name) \ struct btrfs_path *path_name __free(btrfs_free_path) = NULL /* * The state of btrfs root */ enum { /* * btrfs_record_root_in_trans is a multi-step process, and it can race * with the balancing code. But the race is very small, and only the * first time the root is added to each transaction. So IN_TRANS_SETUP * is used to tell us when more checks are required */ BTRFS_ROOT_IN_TRANS_SETUP, /* * Set if tree blocks of this root can be shared by other roots. * Only subvolume trees and their reloc trees have this bit set. * Conflicts with TRACK_DIRTY bit. * * This affects two things: * * - How balance works * For shareable roots, we need to use reloc tree and do path * replacement for balance, and need various pre/post hooks for * snapshot creation to handle them. * * While for non-shareable trees, we just simply do a tree search * with COW. * * - How dirty roots are tracked * For shareable roots, btrfs_record_root_in_trans() is needed to * track them, while non-subvolume roots have TRACK_DIRTY bit, they * don't need to set this manually. */ BTRFS_ROOT_SHAREABLE, BTRFS_ROOT_TRACK_DIRTY, BTRFS_ROOT_IN_RADIX, BTRFS_ROOT_ORPHAN_ITEM_INSERTED, BTRFS_ROOT_DEFRAG_RUNNING, BTRFS_ROOT_FORCE_COW, BTRFS_ROOT_MULTI_LOG_TASKS, BTRFS_ROOT_DIRTY, BTRFS_ROOT_DELETING, /* * Reloc tree is orphan, only kept here for qgroup delayed subtree scan * * Set for the subvolume tree owning the reloc tree. */ BTRFS_ROOT_DEAD_RELOC_TREE, /* Mark dead root stored on device whose cleanup needs to be resumed */ BTRFS_ROOT_DEAD_TREE, /* The root has a log tree. Used for subvolume roots and the tree root. */ BTRFS_ROOT_HAS_LOG_TREE, /* Qgroup flushing is in progress */ BTRFS_ROOT_QGROUP_FLUSHING, /* We started the orphan cleanup for this root. */ BTRFS_ROOT_ORPHAN_CLEANUP, /* This root has a drop operation that was started previously. */ BTRFS_ROOT_UNFINISHED_DROP, /* This reloc root needs to have its buffers lockdep class reset. */ BTRFS_ROOT_RESET_LOCKDEP_CLASS, }; /* * Record swapped tree blocks of a subvolume tree for delayed subtree trace * code. For detail check comment in fs/btrfs/qgroup.c. */ struct btrfs_qgroup_swapped_blocks { spinlock_t lock; /* RM_EMPTY_ROOT() of above blocks[] */ bool swapped; struct rb_root blocks[BTRFS_MAX_LEVEL]; }; /* * in ram representation of the tree. extent_root is used for all allocations * and for the extent tree extent_root root. */ struct btrfs_root { struct rb_node rb_node; struct extent_buffer *node; struct extent_buffer *commit_root; struct btrfs_root *log_root; struct btrfs_root *reloc_root; unsigned long state; struct btrfs_root_item root_item; struct btrfs_key root_key; struct btrfs_fs_info *fs_info; struct extent_io_tree dirty_log_pages; struct mutex objectid_mutex; spinlock_t accounting_lock; struct btrfs_block_rsv *block_rsv; struct mutex log_mutex; wait_queue_head_t log_writer_wait; wait_queue_head_t log_commit_wait[2]; struct list_head log_ctxs[2]; /* Used only for log trees of subvolumes, not for the log root tree */ atomic_t log_writers; atomic_t log_commit[2]; /* Used only for log trees of subvolumes, not for the log root tree */ atomic_t log_batch; /* * Protected by the 'log_mutex' lock but can be read without holding * that lock to avoid unnecessary lock contention, in which case it * should be read using btrfs_get_root_log_transid() except if it's a * log tree in which case it can be directly accessed. Updates to this * field should always use btrfs_set_root_log_transid(), except for log * trees where the field can be updated directly. */ int log_transid; /* No matter the commit succeeds or not*/ int log_transid_committed; /* * Just be updated when the commit succeeds. Use * btrfs_get_root_last_log_commit() and btrfs_set_root_last_log_commit() * to access this field. */ int last_log_commit; pid_t log_start_pid; u64 last_trans; u64 free_objectid; struct btrfs_key defrag_progress; struct btrfs_key defrag_max; /* The dirty list is only used by non-shareable roots */ struct list_head dirty_list; struct list_head root_list; /* * Xarray that keeps track of in-memory inodes, protected by the lock * @inode_lock. */ struct xarray inodes; /* * Xarray that keeps track of delayed nodes of every inode, protected * by @inode_lock. */ struct xarray delayed_nodes; /* * right now this just gets used so that a root has its own devid * for stat. It may be used for more later */ dev_t anon_dev; spinlock_t root_item_lock; refcount_t refs; struct mutex delalloc_mutex; spinlock_t delalloc_lock; /* * all of the inodes that have delalloc bytes. It is possible for * this list to be empty even when there is still dirty data=ordered * extents waiting to finish IO. */ struct list_head delalloc_inodes; struct list_head delalloc_root; u64 nr_delalloc_inodes; struct mutex ordered_extent_mutex; /* * this is used by the balancing code to wait for all the pending * ordered extents */ spinlock_t ordered_extent_lock; /* * all of the data=ordered extents pending writeback * these can span multiple transactions and basically include * every dirty data page that isn't from nodatacow */ struct list_head ordered_extents; struct list_head ordered_root; u64 nr_ordered_extents; /* * Not empty if this subvolume root has gone through tree block swap * (relocation) * * Will be used by reloc_control::dirty_subvol_roots. */ struct list_head reloc_dirty_list; /* * Number of currently running SEND ioctls to prevent * manipulation with the read-only status via SUBVOL_SETFLAGS */ int send_in_progress; /* * Number of currently running deduplication operations that have a * destination inode belonging to this root. Protected by the lock * root_item_lock. */ int dedupe_in_progress; /* For exclusion of snapshot creation and nocow writes */ struct btrfs_drew_lock snapshot_lock; atomic_t snapshot_force_cow; /* For qgroup metadata reserved space */ spinlock_t qgroup_meta_rsv_lock; u64 qgroup_meta_rsv_pertrans; u64 qgroup_meta_rsv_prealloc; wait_queue_head_t qgroup_flush_wait; /* Number of active swapfiles */ atomic_t nr_swapfiles; /* Record pairs of swapped blocks for qgroup */ struct btrfs_qgroup_swapped_blocks swapped_blocks; /* Used only by log trees, when logging csum items */ struct extent_io_tree log_csum_range; /* Used in simple quotas, track root during relocation. */ u64 relocation_src_root; #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS u64 alloc_bytenr; #endif #ifdef CONFIG_BTRFS_DEBUG struct list_head leak_list; #endif }; static inline bool btrfs_root_readonly(const struct btrfs_root *root) { /* Byte-swap the constant at compile time, root_item::flags is LE */ return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY)) != 0; } static inline bool btrfs_root_dead(const struct btrfs_root *root) { /* Byte-swap the constant at compile time, root_item::flags is LE */ return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0; } static inline u64 btrfs_root_id(const struct btrfs_root *root) { return root->root_key.objectid; } static inline int btrfs_get_root_log_transid(const struct btrfs_root *root) { return READ_ONCE(root->log_transid); } static inline void btrfs_set_root_log_transid(struct btrfs_root *root, int log_transid) { WRITE_ONCE(root->log_transid, log_transid); } static inline int btrfs_get_root_last_log_commit(const struct btrfs_root *root) { return READ_ONCE(root->last_log_commit); } static inline void btrfs_set_root_last_log_commit(struct btrfs_root *root, int commit_id) { WRITE_ONCE(root->last_log_commit, commit_id); } static inline u64 btrfs_get_root_last_trans(const struct btrfs_root *root) { return READ_ONCE(root->last_trans); } static inline void btrfs_set_root_last_trans(struct btrfs_root *root, u64 transid) { WRITE_ONCE(root->last_trans, transid); } /* * Return the generation this root started with. * * Every normal root that is created with root->root_key.offset set to it's * originating generation. If it is a snapshot it is the generation when the * snapshot was created. * * However for TREE_RELOC roots root_key.offset is the objectid of the owning * tree root. Thankfully we copy the root item of the owning tree root, which * has it's last_snapshot set to what we would have root_key.offset set to, so * return that if this is a TREE_RELOC root. */ static inline u64 btrfs_root_origin_generation(const struct btrfs_root *root) { if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID) return btrfs_root_last_snapshot(&root->root_item); return root->root_key.offset; } /* * Structure that conveys information about an extent that is going to replace * all the extents in a file range. */ struct btrfs_replace_extent_info { u64 disk_offset; u64 disk_len; u64 data_offset; u64 data_len; u64 file_offset; /* Pointer to a file extent item of type regular or prealloc. */ char *extent_buf; /* * Set to true when attempting to replace a file range with a new extent * described by this structure, set to false when attempting to clone an * existing extent into a file range. */ bool is_new_extent; /* Indicate if we should update the inode's mtime and ctime. */ bool update_times; /* Meaningful only if is_new_extent is true. */ int qgroup_reserved; /* * Meaningful only if is_new_extent is true. * Used to track how many extent items we have already inserted in a * subvolume tree that refer to the extent described by this structure, * so that we know when to create a new delayed ref or update an existing * one. */ int insertions; }; /* Arguments for btrfs_drop_extents() */ struct btrfs_drop_extents_args { /* Input parameters */ /* * If NULL, btrfs_drop_extents() will allocate and free its own path. * If 'replace_extent' is true, this must not be NULL. Also the path * is always released except if 'replace_extent' is true and * btrfs_drop_extents() sets 'extent_inserted' to true, in which case * the path is kept locked. */ struct btrfs_path *path; /* Start offset of the range to drop extents from */ u64 start; /* End (exclusive, last byte + 1) of the range to drop extents from */ u64 end; /* If true drop all the extent maps in the range */ bool drop_cache; /* * If true it means we want to insert a new extent after dropping all * the extents in the range. If this is true, the 'extent_item_size' * parameter must be set as well and the 'extent_inserted' field will * be set to true by btrfs_drop_extents() if it could insert the new * extent. * Note: when this is set to true the path must not be NULL. */ bool replace_extent; /* * Used if 'replace_extent' is true. Size of the file extent item to * insert after dropping all existing extents in the range */ u32 extent_item_size; /* Output parameters */ /* * Set to the minimum between the input parameter 'end' and the end * (exclusive, last byte + 1) of the last dropped extent. This is always * set even if btrfs_drop_extents() returns an error. */ u64 drop_end; /* * The number of allocated bytes found in the range. This can be smaller * than the range's length when there are holes in the range. */ u64 bytes_found; /* * Only set if 'replace_extent' is true. Set to true if we were able * to insert a replacement extent after dropping all extents in the * range, otherwise set to false by btrfs_drop_extents(). * Also, if btrfs_drop_extents() has set this to true it means it * returned with the path locked, otherwise if it has set this to * false it has returned with the path released. */ bool extent_inserted; }; struct btrfs_file_private { void *filldir_buf; u64 last_index; struct extent_state *llseek_cached_state; /* Task that allocated this structure. */ struct task_struct *owner_task; }; static inline u32 BTRFS_LEAF_DATA_SIZE(const struct btrfs_fs_info *info) { return info->nodesize - sizeof(struct btrfs_header); } static inline u32 BTRFS_MAX_ITEM_SIZE(const struct btrfs_fs_info *info) { return BTRFS_LEAF_DATA_SIZE(info) - sizeof(struct btrfs_item); } static inline u32 BTRFS_NODEPTRS_PER_BLOCK(const struct btrfs_fs_info *info) { return BTRFS_LEAF_DATA_SIZE(info) / sizeof(struct btrfs_key_ptr); } static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info) { return BTRFS_MAX_ITEM_SIZE(info) - sizeof(struct btrfs_dir_item); } #define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \ ((bytes) >> (fs_info)->sectorsize_bits) static inline gfp_t btrfs_alloc_write_mask(struct address_space *mapping) { return mapping_gfp_constraint(mapping, ~__GFP_FS); } void btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end); int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes, u64 *actual_bytes); int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range); /* ctree.c */ int __init btrfs_ctree_init(void); void __cold btrfs_ctree_exit(void); int btrfs_bin_search(struct extent_buffer *eb, int first_slot, const struct btrfs_key *key, int *slot); int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2); #ifdef __LITTLE_ENDIAN /* * Compare two keys, on little-endian the disk order is same as CPU order and * we can avoid the conversion. */ static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk_key, const struct btrfs_key *k2) { const struct btrfs_key *k1 = (const struct btrfs_key *)disk_key; return btrfs_comp_cpu_keys(k1, k2); } #else /* Compare two keys in a memcmp fashion. */ static inline int btrfs_comp_keys(const struct btrfs_disk_key *disk, const struct btrfs_key *k2) { struct btrfs_key k1; btrfs_disk_key_to_cpu(&k1, disk); return btrfs_comp_cpu_keys(&k1, k2); } #endif int btrfs_previous_item(struct btrfs_root *root, struct btrfs_path *path, u64 min_objectid, int type); int btrfs_previous_extent_item(struct btrfs_root *root, struct btrfs_path *path, u64 min_objectid); void btrfs_set_item_key_safe(struct btrfs_trans_handle *trans, const struct btrfs_path *path, const struct btrfs_key *new_key); struct extent_buffer *btrfs_root_node(struct btrfs_root *root); int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key, int lowest_level, u64 min_trans); int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, struct btrfs_path *path, u64 min_trans); struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent, int slot); int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, struct extent_buffer **cow_ret, enum btrfs_lock_nesting nest); int btrfs_force_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer *parent, int parent_slot, struct extent_buffer **cow_ret, u64 search_start, u64 empty_size, enum btrfs_lock_nesting nest); int btrfs_copy_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, struct extent_buffer **cow_ret, u64 new_root_objectid); bool btrfs_block_can_be_shared(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf); int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int level, int slot); void btrfs_extend_item(struct btrfs_trans_handle *trans, const struct btrfs_path *path, u32 data_size); void btrfs_truncate_item(struct btrfs_trans_handle *trans, const struct btrfs_path *path, u32 new_size, int from_end); int btrfs_split_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, const struct btrfs_key *new_key, unsigned long split_offset); int btrfs_duplicate_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, const struct btrfs_key *new_key); int btrfs_find_item(struct btrfs_root *fs_root, struct btrfs_path *path, u64 inum, u64 ioff, u8 key_type, struct btrfs_key *found_key); int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, const struct btrfs_key *key, struct btrfs_path *p, int ins_len, int cow); int btrfs_search_old_slot(struct btrfs_root *root, const struct btrfs_key *key, struct btrfs_path *p, u64 time_seq); int btrfs_search_slot_for_read(struct btrfs_root *root, const struct btrfs_key *key, struct btrfs_path *p, int find_higher, int return_any); void btrfs_release_path(struct btrfs_path *p); struct btrfs_path *btrfs_alloc_path(void); void btrfs_free_path(struct btrfs_path *p); DEFINE_FREE(btrfs_free_path, struct btrfs_path *, btrfs_free_path(_T)) int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int slot, int nr); static inline int btrfs_del_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path) { return btrfs_del_items(trans, root, path, path->slots[0], 1); } /* * Describes a batch of items to insert in a btree. This is used by * btrfs_insert_empty_items(). */ struct btrfs_item_batch { /* * Pointer to an array containing the keys of the items to insert (in * sorted order). */ const struct btrfs_key *keys; /* Pointer to an array containing the data size for each item to insert. */ const u32 *data_sizes; /* * The sum of data sizes for all items. The caller can compute this while * setting up the data_sizes array, so it ends up being more efficient * than having btrfs_insert_empty_items() or setup_item_for_insert() * doing it, as it would avoid an extra loop over a potentially large * array, and in the case of setup_item_for_insert(), we would be doing * it while holding a write lock on a leaf and often on upper level nodes * too, unnecessarily increasing the size of a critical section. */ u32 total_data_size; /* Size of the keys and data_sizes arrays (number of items in the batch). */ int nr; }; void btrfs_setup_item_for_insert(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, const struct btrfs_key *key, u32 data_size); int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const struct btrfs_key *key, void *data, u32 data_size); int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, const struct btrfs_item_batch *batch); static inline int btrfs_insert_empty_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, const struct btrfs_key *key, u32 data_size) { struct btrfs_item_batch batch; batch.keys = key; batch.data_sizes = &data_size; batch.total_data_size = data_size; batch.nr = 1; return btrfs_insert_empty_items(trans, root, path, &batch); } int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq); int btrfs_search_backwards(struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *path); int btrfs_get_next_valid_item(struct btrfs_root *root, struct btrfs_key *key, struct btrfs_path *path); /* * Search in @root for a given @key, and store the slot found in @found_key. * * @root: The root node of the tree. * @key: The key we are looking for. * @found_key: Will hold the found item. * @path: Holds the current slot/leaf. * @iter_ret: Contains the value returned from btrfs_search_slot or * btrfs_get_next_valid_item, whichever was executed last. * * The @iter_ret is an output variable that will contain the return value of * btrfs_search_slot, if it encountered an error, or the value returned from * btrfs_get_next_valid_item otherwise. That return value can be 0, if a valid * slot was found, 1 if there were no more leaves, and <0 if there was an error. * * It's recommended to use a separate variable for iter_ret and then use it to * set the function return value so there's no confusion of the 0/1/errno * values stemming from btrfs_search_slot. */ #define btrfs_for_each_slot(root, key, found_key, path, iter_ret) \ for (iter_ret = btrfs_search_slot(NULL, (root), (key), (path), 0, 0); \ (iter_ret) >= 0 && \ (iter_ret = btrfs_get_next_valid_item((root), (found_key), (path))) == 0; \ (path)->slots[0]++ \ ) int btrfs_next_old_item(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq); /* * Search the tree again to find a leaf with greater keys. * * Returns 0 if it found something or 1 if there are no greater leaves. * Returns < 0 on error. */ static inline int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) { return btrfs_next_old_leaf(root, path, 0); } static inline int btrfs_next_item(struct btrfs_root *root, struct btrfs_path *p) { return btrfs_next_old_item(root, p, 0); } int btrfs_leaf_free_space(const struct extent_buffer *leaf); static inline int is_fstree(u64 rootid) { if (rootid == BTRFS_FS_TREE_OBJECTID || ((s64)rootid >= (s64)BTRFS_FIRST_FREE_OBJECTID && !btrfs_qgroup_level(rootid))) return 1; return 0; } static inline bool btrfs_is_data_reloc_root(const struct btrfs_root *root) { return root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID; } u16 btrfs_csum_type_size(u16 type); int btrfs_super_csum_size(const struct btrfs_super_block *s); const char *btrfs_super_csum_name(u16 csum_type); const char *btrfs_super_csum_driver(u16 csum_type); size_t __attribute_const__ btrfs_get_num_csums(void); /* * We use folio flag owner_2 to indicate there is an ordered extent with * unfinished IO. */ #define folio_test_ordered(folio) folio_test_owner_2(folio) #define folio_set_ordered(folio) folio_set_owner_2(folio) #define folio_clear_ordered(folio) folio_clear_owner_2(folio) #endif