| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Copyright (C) 2008 Oracle. All rights reserved. |
| */ |
| |
| #ifndef BTRFS_DELAYED_REF_H |
| #define BTRFS_DELAYED_REF_H |
| |
| #include <linux/refcount.h> |
| |
| /* these are the possible values of struct btrfs_delayed_ref_node->action */ |
| #define BTRFS_ADD_DELAYED_REF 1 /* add one backref to the tree */ |
| #define BTRFS_DROP_DELAYED_REF 2 /* delete one backref from the tree */ |
| #define BTRFS_ADD_DELAYED_EXTENT 3 /* record a full extent allocation */ |
| #define BTRFS_UPDATE_DELAYED_HEAD 4 /* not changing ref count on head ref */ |
| |
| struct btrfs_delayed_ref_node { |
| struct rb_node ref_node; |
| /* |
| * If action is BTRFS_ADD_DELAYED_REF, also link this node to |
| * ref_head->ref_add_list, then we do not need to iterate the |
| * whole ref_head->ref_list to find BTRFS_ADD_DELAYED_REF nodes. |
| */ |
| struct list_head add_list; |
| |
| /* the starting bytenr of the extent */ |
| u64 bytenr; |
| |
| /* the size of the extent */ |
| u64 num_bytes; |
| |
| /* seq number to keep track of insertion order */ |
| u64 seq; |
| |
| /* ref count on this data structure */ |
| refcount_t refs; |
| |
| /* |
| * how many refs is this entry adding or deleting. For |
| * head refs, this may be a negative number because it is keeping |
| * track of the total mods done to the reference count. |
| * For individual refs, this will always be a positive number |
| * |
| * It may be more than one, since it is possible for a single |
| * parent to have more than one ref on an extent |
| */ |
| int ref_mod; |
| |
| unsigned int action:8; |
| unsigned int type:8; |
| /* is this node still in the rbtree? */ |
| unsigned int is_head:1; |
| unsigned int in_tree:1; |
| }; |
| |
| struct btrfs_delayed_extent_op { |
| struct btrfs_disk_key key; |
| u8 level; |
| bool update_key; |
| bool update_flags; |
| bool is_data; |
| u64 flags_to_set; |
| }; |
| |
| /* |
| * the head refs are used to hold a lock on a given extent, which allows us |
| * to make sure that only one process is running the delayed refs |
| * at a time for a single extent. They also store the sum of all the |
| * reference count modifications we've queued up. |
| */ |
| struct btrfs_delayed_ref_head { |
| u64 bytenr; |
| u64 num_bytes; |
| refcount_t refs; |
| /* |
| * the mutex is held while running the refs, and it is also |
| * held when checking the sum of reference modifications. |
| */ |
| struct mutex mutex; |
| |
| spinlock_t lock; |
| struct rb_root_cached ref_tree; |
| /* accumulate add BTRFS_ADD_DELAYED_REF nodes to this ref_add_list. */ |
| struct list_head ref_add_list; |
| |
| struct rb_node href_node; |
| |
| struct btrfs_delayed_extent_op *extent_op; |
| |
| /* |
| * This is used to track the final ref_mod from all the refs associated |
| * with this head ref, this is not adjusted as delayed refs are run, |
| * this is meant to track if we need to do the csum accounting or not. |
| */ |
| int total_ref_mod; |
| |
| /* |
| * This is the current outstanding mod references for this bytenr. This |
| * is used with lookup_extent_info to get an accurate reference count |
| * for a bytenr, so it is adjusted as delayed refs are run so that any |
| * on disk reference count + ref_mod is accurate. |
| */ |
| int ref_mod; |
| |
| /* |
| * when a new extent is allocated, it is just reserved in memory |
| * The actual extent isn't inserted into the extent allocation tree |
| * until the delayed ref is processed. must_insert_reserved is |
| * used to flag a delayed ref so the accounting can be updated |
| * when a full insert is done. |
| * |
| * It is possible the extent will be freed before it is ever |
| * inserted into the extent allocation tree. In this case |
| * we need to update the in ram accounting to properly reflect |
| * the free has happened. |
| */ |
| unsigned int must_insert_reserved:1; |
| unsigned int is_data:1; |
| unsigned int is_system:1; |
| unsigned int processing:1; |
| }; |
| |
| struct btrfs_delayed_tree_ref { |
| struct btrfs_delayed_ref_node node; |
| u64 root; |
| u64 parent; |
| int level; |
| }; |
| |
| struct btrfs_delayed_data_ref { |
| struct btrfs_delayed_ref_node node; |
| u64 root; |
| u64 parent; |
| u64 objectid; |
| u64 offset; |
| }; |
| |
| struct btrfs_delayed_ref_root { |
| /* head ref rbtree */ |
| struct rb_root_cached href_root; |
| |
| /* dirty extent records */ |
| struct rb_root dirty_extent_root; |
| |
| /* this spin lock protects the rbtree and the entries inside */ |
| spinlock_t lock; |
| |
| /* how many delayed ref updates we've queued, used by the |
| * throttling code |
| */ |
| atomic_t num_entries; |
| |
| /* total number of head nodes in tree */ |
| unsigned long num_heads; |
| |
| /* total number of head nodes ready for processing */ |
| unsigned long num_heads_ready; |
| |
| u64 pending_csums; |
| |
| /* |
| * set when the tree is flushing before a transaction commit, |
| * used by the throttling code to decide if new updates need |
| * to be run right away |
| */ |
| int flushing; |
| |
| u64 run_delayed_start; |
| |
| /* |
| * To make qgroup to skip given root. |
| * This is for snapshot, as btrfs_qgroup_inherit() will manually |
| * modify counters for snapshot and its source, so we should skip |
| * the snapshot in new_root/old_roots or it will get calculated twice |
| */ |
| u64 qgroup_to_skip; |
| }; |
| |
| enum btrfs_ref_type { |
| BTRFS_REF_NOT_SET, |
| BTRFS_REF_DATA, |
| BTRFS_REF_METADATA, |
| BTRFS_REF_LAST, |
| }; |
| |
| struct btrfs_data_ref { |
| /* For EXTENT_DATA_REF */ |
| |
| /* Root which refers to this data extent */ |
| u64 ref_root; |
| |
| /* Inode which refers to this data extent */ |
| u64 ino; |
| |
| /* |
| * file_offset - extent_offset |
| * |
| * file_offset is the key.offset of the EXTENT_DATA key. |
| * extent_offset is btrfs_file_extent_offset() of the EXTENT_DATA data. |
| */ |
| u64 offset; |
| }; |
| |
| struct btrfs_tree_ref { |
| /* |
| * Level of this tree block |
| * |
| * Shared for skinny (TREE_BLOCK_REF) and normal tree ref. |
| */ |
| int level; |
| |
| /* |
| * Root which refers to this tree block. |
| * |
| * For TREE_BLOCK_REF (skinny metadata, either inline or keyed) |
| */ |
| u64 root; |
| |
| /* For non-skinny metadata, no special member needed */ |
| }; |
| |
| struct btrfs_ref { |
| enum btrfs_ref_type type; |
| int action; |
| |
| /* |
| * Whether this extent should go through qgroup record. |
| * |
| * Normally false, but for certain cases like delayed subtree scan, |
| * setting this flag can hugely reduce qgroup overhead. |
| */ |
| bool skip_qgroup; |
| |
| /* |
| * Optional. For which root is this modification. |
| * Mostly used for qgroup optimization. |
| * |
| * When unset, data/tree ref init code will populate it. |
| * In certain cases, we're modifying reference for a different root. |
| * E.g. COW fs tree blocks for balance. |
| * In that case, tree_ref::root will be fs tree, but we're doing this |
| * for reloc tree, then we should set @real_root to reloc tree. |
| */ |
| u64 real_root; |
| u64 bytenr; |
| u64 len; |
| |
| /* Bytenr of the parent tree block */ |
| u64 parent; |
| union { |
| struct btrfs_data_ref data_ref; |
| struct btrfs_tree_ref tree_ref; |
| }; |
| }; |
| |
| extern struct kmem_cache *btrfs_delayed_ref_head_cachep; |
| extern struct kmem_cache *btrfs_delayed_tree_ref_cachep; |
| extern struct kmem_cache *btrfs_delayed_data_ref_cachep; |
| extern struct kmem_cache *btrfs_delayed_extent_op_cachep; |
| |
| int __init btrfs_delayed_ref_init(void); |
| void __cold btrfs_delayed_ref_exit(void); |
| |
| static inline void btrfs_init_generic_ref(struct btrfs_ref *generic_ref, |
| int action, u64 bytenr, u64 len, u64 parent) |
| { |
| generic_ref->action = action; |
| generic_ref->bytenr = bytenr; |
| generic_ref->len = len; |
| generic_ref->parent = parent; |
| } |
| |
| static inline void btrfs_init_tree_ref(struct btrfs_ref *generic_ref, |
| int level, u64 root) |
| { |
| /* If @real_root not set, use @root as fallback */ |
| if (!generic_ref->real_root) |
| generic_ref->real_root = root; |
| generic_ref->tree_ref.level = level; |
| generic_ref->tree_ref.root = root; |
| generic_ref->type = BTRFS_REF_METADATA; |
| } |
| |
| static inline void btrfs_init_data_ref(struct btrfs_ref *generic_ref, |
| u64 ref_root, u64 ino, u64 offset) |
| { |
| /* If @real_root not set, use @root as fallback */ |
| if (!generic_ref->real_root) |
| generic_ref->real_root = ref_root; |
| generic_ref->data_ref.ref_root = ref_root; |
| generic_ref->data_ref.ino = ino; |
| generic_ref->data_ref.offset = offset; |
| generic_ref->type = BTRFS_REF_DATA; |
| } |
| |
| static inline struct btrfs_delayed_extent_op * |
| btrfs_alloc_delayed_extent_op(void) |
| { |
| return kmem_cache_alloc(btrfs_delayed_extent_op_cachep, GFP_NOFS); |
| } |
| |
| static inline void |
| btrfs_free_delayed_extent_op(struct btrfs_delayed_extent_op *op) |
| { |
| if (op) |
| kmem_cache_free(btrfs_delayed_extent_op_cachep, op); |
| } |
| |
| static inline void btrfs_put_delayed_ref(struct btrfs_delayed_ref_node *ref) |
| { |
| WARN_ON(refcount_read(&ref->refs) == 0); |
| if (refcount_dec_and_test(&ref->refs)) { |
| WARN_ON(ref->in_tree); |
| switch (ref->type) { |
| case BTRFS_TREE_BLOCK_REF_KEY: |
| case BTRFS_SHARED_BLOCK_REF_KEY: |
| kmem_cache_free(btrfs_delayed_tree_ref_cachep, ref); |
| break; |
| case BTRFS_EXTENT_DATA_REF_KEY: |
| case BTRFS_SHARED_DATA_REF_KEY: |
| kmem_cache_free(btrfs_delayed_data_ref_cachep, ref); |
| break; |
| default: |
| BUG(); |
| } |
| } |
| } |
| |
| static inline void btrfs_put_delayed_ref_head(struct btrfs_delayed_ref_head *head) |
| { |
| if (refcount_dec_and_test(&head->refs)) |
| kmem_cache_free(btrfs_delayed_ref_head_cachep, head); |
| } |
| |
| int btrfs_add_delayed_tree_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_ref *generic_ref, |
| struct btrfs_delayed_extent_op *extent_op, |
| int *old_ref_mod, int *new_ref_mod); |
| int btrfs_add_delayed_data_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_ref *generic_ref, |
| u64 reserved, int *old_ref_mod, |
| int *new_ref_mod); |
| int btrfs_add_delayed_extent_op(struct btrfs_trans_handle *trans, |
| u64 bytenr, u64 num_bytes, |
| struct btrfs_delayed_extent_op *extent_op); |
| void btrfs_merge_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_head *head); |
| |
| struct btrfs_delayed_ref_head * |
| btrfs_find_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, |
| u64 bytenr); |
| int btrfs_delayed_ref_lock(struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_head *head); |
| static inline void btrfs_delayed_ref_unlock(struct btrfs_delayed_ref_head *head) |
| { |
| mutex_unlock(&head->mutex); |
| } |
| void btrfs_delete_ref_head(struct btrfs_delayed_ref_root *delayed_refs, |
| struct btrfs_delayed_ref_head *head); |
| |
| struct btrfs_delayed_ref_head *btrfs_select_ref_head( |
| struct btrfs_delayed_ref_root *delayed_refs); |
| |
| int btrfs_check_delayed_seq(struct btrfs_fs_info *fs_info, u64 seq); |
| |
| /* |
| * helper functions to cast a node into its container |
| */ |
| static inline struct btrfs_delayed_tree_ref * |
| btrfs_delayed_node_to_tree_ref(struct btrfs_delayed_ref_node *node) |
| { |
| return container_of(node, struct btrfs_delayed_tree_ref, node); |
| } |
| |
| static inline struct btrfs_delayed_data_ref * |
| btrfs_delayed_node_to_data_ref(struct btrfs_delayed_ref_node *node) |
| { |
| return container_of(node, struct btrfs_delayed_data_ref, node); |
| } |
| |
| #endif |