diff options
Diffstat (limited to 'fs/btrfs/backref.h')
| -rw-r--r-- | fs/btrfs/backref.h | 76 |
1 files changed, 61 insertions, 15 deletions
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 2eb99f23cc8f..ce700dfcc016 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -13,11 +13,63 @@ #include "extent_io.h" /* - * Pass to backref walking functions to tell them to include references from - * all file extent items that point to the target data extent, regardless if - * they refer to the whole extent or just sections of it (bookend extents). + * Context and arguments for backref walking functions. Some of the fields are + * to be filled by the caller of such functions while other are filled by the + * functions themselves, as described below. */ -#define BTRFS_IGNORE_EXTENT_OFFSET ((u64)-1) +struct btrfs_backref_walk_ctx { + /* + * The address of the extent for which we are doing backref walking. + * Can be either a data extent or a metadata extent. + * + * Must always be set by the top level caller. + */ + u64 bytenr; + /* + * Offset relative to the target extent. This is only used for data + * extents, and it's meaningful because we can have file extent items + * that point only to a section of a data extent ("bookend" extents), + * and we want to filter out any that don't point to a section of the + * data extent containing the given offset. + * + * Must always be set by the top level caller. + */ + u64 extent_item_pos; + /* + * If true and bytenr corresponds to a data extent, then references from + * all file extent items that point to the data extent are considered, + * @extent_item_pos is ignored. + */ + bool ignore_extent_item_pos; + /* A valid transaction handle or NULL. */ + struct btrfs_trans_handle *trans; + /* + * The file system's info object, can not be NULL. + * + * Must always be set by the top level caller. + */ + struct btrfs_fs_info *fs_info; + /* + * Time sequence acquired from btrfs_get_tree_mod_seq(), in case the + * caller joined the tree mod log to get a consistent view of b+trees + * while we do backref walking, or BTRFS_SEQ_LAST. + * When using BTRFS_SEQ_LAST, delayed refs are not checked and it uses + * commit roots when searching b+trees - this is a special case for + * qgroups used during a transaction commit. + */ + u64 time_seq; + /* + * Used to collect the bytenr of metadata extents that point to the + * target extent. + */ + struct ulist *refs; + /* + * List used to collect the IDs of the roots from which the target + * extent is accessible. Can be NULL in case the caller does not care + * about collecting root IDs. + */ + struct ulist *roots; +}; struct inode_fs_paths { struct btrfs_path *btrfs_path; @@ -96,10 +148,9 @@ 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); +int iterate_extent_inodes(struct btrfs_backref_walk_ctx *ctx, + bool search_commit_root, + iterate_extent_inodes_t *iterate, void *user_ctx); int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, struct btrfs_path *path, void *ctx, @@ -107,13 +158,8 @@ int iterate_inodes_from_logical(u64 logical, struct btrfs_fs_info *fs_info, 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, - u64 extent_item_pos); -int btrfs_find_all_roots(struct btrfs_trans_handle *trans, - struct btrfs_fs_info *fs_info, u64 bytenr, - u64 time_seq, struct ulist **roots, +int btrfs_find_all_leafs(struct btrfs_backref_walk_ctx *ctx); +int btrfs_find_all_roots(struct btrfs_backref_walk_ctx *ctx, bool skip_commit_root_sem); char *btrfs_ref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path, u32 name_len, unsigned long name_off, |