/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2011 Red Hat, Inc. * * This file is released under the GPL. */ #ifndef DM_BTREE_INTERNAL_H #define DM_BTREE_INTERNAL_H #include "dm-btree.h" /*----------------------------------------------------------------*/ /* * We'll need 2 accessor functions for n->csum and n->blocknr * to support dm-btree-spine.c in that case. */ enum node_flags { … }; /* * Every btree node begins with this structure. Make sure it's a multiple * of 8-bytes in size, otherwise the 64bit keys will be mis-aligned. */ struct node_header { … } __packed __aligned(…); struct btree_node { … } __packed __aligned(…); /* * Locks a block using the btree node validator. */ int bn_read_lock(struct dm_btree_info *info, dm_block_t b, struct dm_block **result); void inc_children(struct dm_transaction_manager *tm, struct btree_node *n, struct dm_btree_value_type *vt); int new_block(struct dm_btree_info *info, struct dm_block **result); void unlock_block(struct dm_btree_info *info, struct dm_block *b); /* * Spines keep track of the rolling locks. There are 2 variants, read-only * and one that uses shadowing. These are separate structs to allow the * type checker to spot misuse, for example accidentally calling read_lock * on a shadow spine. */ struct ro_spine { … }; void init_ro_spine(struct ro_spine *s, struct dm_btree_info *info); void exit_ro_spine(struct ro_spine *s); int ro_step(struct ro_spine *s, dm_block_t new_child); void ro_pop(struct ro_spine *s); struct btree_node *ro_node(struct ro_spine *s); struct shadow_spine { … }; void init_shadow_spine(struct shadow_spine *s, struct dm_btree_info *info); void exit_shadow_spine(struct shadow_spine *s); int shadow_step(struct shadow_spine *s, dm_block_t b, struct dm_btree_value_type *vt); /* * The spine must have at least one entry before calling this. */ struct dm_block *shadow_current(struct shadow_spine *s); /* * The spine must have at least two entries before calling this. */ struct dm_block *shadow_parent(struct shadow_spine *s); int shadow_has_parent(struct shadow_spine *s); dm_block_t shadow_root(struct shadow_spine *s); /* * Some inlines. */ static inline __le64 *key_ptr(struct btree_node *n, uint32_t index) { … } static inline void *value_base(struct btree_node *n) { … } static inline void *value_ptr(struct btree_node *n, uint32_t index) { … } /* * Assumes the values are suitably-aligned and converts to core format. */ static inline uint64_t value64(struct btree_node *n, uint32_t index) { … } /* * Searching for a key within a single node. */ int lower_bound(struct btree_node *n, uint64_t key); extern const struct dm_block_validator btree_node_validator; /* * Value type for upper levels of multi-level btrees. */ extern void init_le64_type(struct dm_transaction_manager *tm, struct dm_btree_value_type *vt); /* * This returns a shadowed btree leaf that you may modify. In practise * this means overwrites only, since an insert could cause a node to * be split. Useful if you need access to the old value to calculate the * new one. * * This only works with single level btrees. The given key must be present in * the tree, otherwise -EINVAL will be returned. */ int btree_get_overwrite_leaf(struct dm_btree_info *info, dm_block_t root, uint64_t key, int *index, dm_block_t *new_root, struct dm_block **leaf); #endif /* DM_BTREE_INTERNAL_H */
Codebase Browser
linux