/* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (C) 2011 STRATO. All rights reserved. */ #ifndef BTRFS_BACKREF_H #define BTRFS_BACKREF_H #include <linux/btrfs.h> #include "ulist.h" #include "disk-io.h" #include "extent_io.h" struct inode_fs_paths { struct btrfs_path *btrfs_path; struct btrfs_root *fs_root; struct btrfs_data_container *fspath; }; typedef int (iterate_extent_inodes_t)(u64 inum, u64 offset, u64 root, void *ctx); int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical, struct btrfs_path *path, struct btrfs_key *found_key, u64 *flags); int tree_backref_for_extent(unsigned long *ptr, struct extent_buffer *eb, struct btrfs_key *key, struct btrfs_extent_item *ei, u32 item_size, u64 *out_root, u8 *out_level); int iterate_extent_inodes(struct btrfs_fs_info *fs_info, u64 extent_item_objectid, u64 extent_offset, int search_commit_root, iterate_extent_inodes_t *iterate, void *ctx, bool ignore_offset); int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, struct btrfs_path *path, iterate_extent_inodes_t *iterate, void *ctx, bool ignore_offset); int paths_from_inode(u64 inum, struct inode_fs_paths *ipath); int btrfs_find_all_leafs(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 time_seq, struct ulist **leafs, const u64 *extent_item_pos, bool ignore_offset); int btrfs_find_all_roots(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 time_seq, struct ulist **roots, bool ignore_offset); char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, u32 name_len, unsigned long name_off, struct extent_buffer *eb_in, u64 parent, char *dest, u32 size); struct btrfs_data_container *init_data_container(u32 total_bytes); struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root, struct btrfs_path *path); void free_ipath(struct inode_fs_paths *ipath); int btrfs_find_one_extref(struct btrfs_root *root, u64 inode_objectid, u64 start_off, struct btrfs_path *path, struct btrfs_inode_extref **ret_extref, u64 *found_off); int btrfs_check_shared(struct btrfs_root *root, u64 inum, u64 bytenr, struct ulist *roots, struct ulist *tmp_ulist); int __init btrfs_prelim_ref_init(void); void __cold btrfs_prelim_ref_exit(void); struct prelim_ref { struct rb_node rbnode; u64 root_id; struct btrfs_key key_for_search; int level; int count; struct extent_inode_elem *inode_list; u64 parent; u64 wanted_disk_byte; }; /* * Iterate backrefs of one extent. * * Now it only supports iteration of tree block in commit root. */ struct btrfs_backref_iter { u64 bytenr; struct btrfs_path *path; struct btrfs_fs_info *fs_info; struct btrfs_key cur_key; u32 item_ptr; u32 cur_ptr; u32 end_ptr; }; struct btrfs_backref_iter *btrfs_backref_iter_alloc( struct btrfs_fs_info *fs_info, gfp_t gfp_flag); static inline void btrfs_backref_iter_free(struct btrfs_backref_iter *iter) { if (!iter) return; btrfs_free_path(iter->path); kfree(iter); } static inline struct extent_buffer *btrfs_backref_get_eb( struct btrfs_backref_iter *iter) { if (!iter) return NULL; return iter->path->nodes[0]; } /* * For metadata with EXTENT_ITEM key (non-skinny) case, the first inline data * is btrfs_tree_block_info, without a btrfs_extent_inline_ref header. * * This helper determines if that's the case. */ static inline bool btrfs_backref_has_tree_block_info( struct btrfs_backref_iter *iter) { if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY && iter->cur_ptr - iter->item_ptr == sizeof(struct btrfs_extent_item)) return true; return false; } int btrfs_backref_iter_start(struct btrfs_backref_iter *iter, u64 bytenr); int btrfs_backref_iter_next(struct btrfs_backref_iter *iter); static inline bool btrfs_backref_iter_is_inline_ref( struct btrfs_backref_iter *iter) { if (iter->cur_key.type == BTRFS_EXTENT_ITEM_KEY || iter->cur_key.type == BTRFS_METADATA_ITEM_KEY) return true; return false; } static inline void btrfs_backref_iter_release(struct btrfs_backref_iter *iter) { iter->bytenr = 0; iter->item_ptr = 0; iter->cur_ptr = 0; iter->end_ptr = 0; btrfs_release_path(iter->path); memset(&iter->cur_key, 0, sizeof(iter->cur_key)); } /* * Backref cache related structures * * The whole objective of backref_cache is to build a bi-directional map * of tree blocks (represented by backref_node) and all their parents. */ /* * Represent a tree block in the backref cache */ struct btrfs_backref_node { struct { struct rb_node rb_node; u64 bytenr; }; /* Use rb_simple_node for search/insert */ u64 new_bytenr; /* Objectid of tree block owner, can be not uptodate */ u64 owner; /* Link to pending, changed or detached list */ struct list_head list; /* List of upper level edges, which link this node to its parents */ struct list_head upper; /* List of lower level edges, which link this node to its children */ struct list_head lower; /* NULL if this node is not tree root */ struct btrfs_root *root; /* Extent buffer got by COWing the block */ struct extent_buffer *eb; /* Level of the tree block */ unsigned int level:8; /* Is the block in a non-shareable tree */ unsigned int cowonly:1; /* 1 if no child node is in the cache */ unsigned int lowest:1; /* Is the extent buffer locked */ unsigned int locked:1; /* Has the block been processed */ unsigned int processed:1; /* Have backrefs of this block been checked */ unsigned int checked:1; /* * 1 if corresponding block has been COWed but some upper level block * pointers may not point to the new location */ unsigned int pending:1; /* 1 if the backref node isn't connected to any other backref node */ unsigned int detached:1; /* * For generic purpose backref cache, where we only care if it's a reloc * root, doesn't care the source subvolid. */ unsigned int is_reloc_root:1; }; #define LOWER 0 #define UPPER 1 /* * Represent an edge connecting upper and lower backref nodes. */ struct btrfs_backref_edge { /* * list[LOWER] is linked to btrfs_backref_node::upper of lower level * node, and list[UPPER] is linked to btrfs_backref_node::lower of * upper level node. * * Also, build_backref_tree() uses list[UPPER] for pending edges, before * linking list[UPPER] to its upper level nodes. */ struct list_head list[2]; /* Two related nodes */ struct btrfs_backref_node *node[2]; }; struct btrfs_backref_cache { /* Red black tree of all backref nodes in the cache */ struct rb_root rb_root; /* For passing backref nodes to btrfs_reloc_cow_block */ struct btrfs_backref_node *path[BTRFS_MAX_LEVEL]; /* * List of blocks that have been COWed but some block pointers in upper * level blocks may not reflect the new location */ struct list_head pending[BTRFS_MAX_LEVEL]; /* List of backref nodes with no child node */ struct list_head leaves; /* List of blocks that have been COWed in current transaction */ struct list_head changed; /* List of detached backref node. */ struct list_head detached; u64 last_trans; int nr_nodes; int nr_edges; /* List of unchecked backref edges during backref cache build */ struct list_head pending_edge; /* List of useless backref nodes during backref cache build */ struct list_head useless_node; struct btrfs_fs_info *fs_info; /* * Whether this cache is for relocation * * Reloction backref cache require more info for reloc root compared * to generic backref cache. */ unsigned int is_reloc; }; void btrfs_backref_init_cache(struct btrfs_fs_info *fs_info, struct btrfs_backref_cache *cache, int is_reloc); struct btrfs_backref_node *btrfs_backref_alloc_node( struct btrfs_backref_cache *cache, u64 bytenr, int level); struct btrfs_backref_edge *btrfs_backref_alloc_edge( struct btrfs_backref_cache *cache); #define LINK_LOWER (1 << 0) #define LINK_UPPER (1 << 1) static inline void btrfs_backref_link_edge(struct btrfs_backref_edge *edge, struct btrfs_backref_node *lower, struct btrfs_backref_node *upper, int link_which) { ASSERT(upper && lower && upper->level == lower->level + 1); edge->node[LOWER] = lower; edge->node[UPPER] = upper; if (link_which & LINK_LOWER) list_add_tail(&edge->list[LOWER], &lower->upper); if (link_which & LINK_UPPER) list_add_tail(&edge->list[UPPER], &upper->lower); } static inline void btrfs_backref_free_node(struct btrfs_backref_cache *cache, struct btrfs_backref_node *node) { if (node) { ASSERT(list_empty(&node->list)); ASSERT(list_empty(&node->lower)); ASSERT(node->eb == NULL); cache->nr_nodes--; btrfs_put_root(node->root); kfree(node); } } static inline void btrfs_backref_free_edge(struct btrfs_backref_cache *cache, struct btrfs_backref_edge *edge) { if (edge) { cache->nr_edges--; kfree(edge); } } static inline void btrfs_backref_unlock_node_buffer( struct btrfs_backref_node *node) { if (node->locked) { btrfs_tree_unlock(node->eb); node->locked = 0; } } static inline void btrfs_backref_drop_node_buffer( struct btrfs_backref_node *node) { if (node->eb) { btrfs_backref_unlock_node_buffer(node); free_extent_buffer(node->eb); node->eb = NULL; } } /* * Drop the backref node from cache without cleaning up its children * edges. * * This can only be called on node without parent edges. * The children edges are still kept as is. */ static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree, struct btrfs_backref_node *node) { ASSERT(list_empty(&node->upper)); btrfs_backref_drop_node_buffer(node); list_del_init(&node->list); list_del_init(&node->lower); if (!RB_EMPTY_NODE(&node->rb_node)) rb_erase(&node->rb_node, &tree->rb_root); btrfs_backref_free_node(tree, node); } void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache, struct btrfs_backref_node *node); void btrfs_backref_release_cache(struct btrfs_backref_cache *cache); static inline void btrfs_backref_panic(struct btrfs_fs_info *fs_info, u64 bytenr, int errno) { btrfs_panic(fs_info, errno, "Inconsistency in backref cache found at offset %llu", bytenr); } int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache, struct btrfs_path *path, struct btrfs_backref_iter *iter, struct btrfs_key *node_key, struct btrfs_backref_node *cur); int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache, struct btrfs_backref_node *start); void btrfs_backref_error_cleanup(struct btrfs_backref_cache *cache, struct btrfs_backref_node *node); #endif