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Diffstat (limited to 'fs/xfs/scrub/dirtree.h')
| -rw-r--r-- | fs/xfs/scrub/dirtree.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/fs/xfs/scrub/dirtree.h b/fs/xfs/scrub/dirtree.h new file mode 100644 index 000000000000..1e1686365c61 --- /dev/null +++ b/fs/xfs/scrub/dirtree.h @@ -0,0 +1,178 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2023-2024 Oracle. All Rights Reserved. + * Author: Darrick J. Wong <djwong@kernel.org> + */ +#ifndef __XFS_SCRUB_DIRTREE_H__ +#define __XFS_SCRUB_DIRTREE_H__ + +/* + * Each of these represents one parent pointer path step in a chain going + * up towards the directory tree root. These are stored inside an xfarray. + */ +struct xchk_dirpath_step { + /* Directory entry name associated with this parent link. */ + xfblob_cookie name_cookie; + unsigned int name_len; + + /* Handle of the parent directory. */ + struct xfs_parent_rec pptr_rec; +}; + +enum xchk_dirpath_outcome { + XCHK_DIRPATH_SCANNING = 0, /* still being put together */ + XCHK_DIRPATH_DELETE, /* delete this path */ + XCHK_DIRPATH_CORRUPT, /* corruption detected in path */ + XCHK_DIRPATH_LOOP, /* cycle detected further up */ + XCHK_DIRPATH_STALE, /* path is stale */ + XCHK_DIRPATH_OK, /* path reaches the root */ + + XREP_DIRPATH_DELETING, /* path is being deleted */ + XREP_DIRPATH_DELETED, /* path has been deleted */ + XREP_DIRPATH_ADOPTING, /* path is being adopted */ + XREP_DIRPATH_ADOPTED, /* path has been adopted */ +}; + +/* + * Each of these represents one parent pointer path out of the directory being + * scanned. These exist in-core, and hopefully there aren't more than a + * handful of them. + */ +struct xchk_dirpath { + struct list_head list; + + /* Index of the first step in this path. */ + xfarray_idx_t first_step; + + /* Index of the second step in this path. */ + xfarray_idx_t second_step; + + /* Inodes seen while walking this path. */ + struct xino_bitmap seen_inodes; + + /* Number of steps in this path. */ + unsigned int nr_steps; + + /* Which path is this? */ + unsigned int path_nr; + + /* What did we conclude from following this path? */ + enum xchk_dirpath_outcome outcome; +}; + +struct xchk_dirtree_outcomes { + /* Number of XCHK_DIRPATH_DELETE */ + unsigned int bad; + + /* Number of XCHK_DIRPATH_CORRUPT or XCHK_DIRPATH_LOOP */ + unsigned int suspect; + + /* Number of XCHK_DIRPATH_OK */ + unsigned int good; + + /* Directory needs to be added to lost+found */ + bool needs_adoption; +}; + +struct xchk_dirtree { + struct xfs_scrub *sc; + + /* Root inode that we're looking for. */ + xfs_ino_t root_ino; + + /* + * This is the inode that we're scanning. The live update hook can + * continue to be called after xchk_teardown drops sc->ip but before + * it calls buf_cleanup, so we keep a copy. + */ + xfs_ino_t scan_ino; + + /* + * If we start deleting redundant paths to this subdirectory, this is + * the inode number of the surviving parent and the dotdot entry will + * be set to this value. If the value is NULLFSINO, then use @root_ino + * as a stand-in until the orphanage can adopt the subdirectory. + */ + xfs_ino_t parent_ino; + + /* Scratch buffer for scanning pptr xattrs */ + struct xfs_parent_rec pptr_rec; + struct xfs_da_args pptr_args; + + /* Name buffer */ + struct xfs_name xname; + char namebuf[MAXNAMELEN]; + + /* Information for reparenting this directory. */ + struct xrep_adoption adoption; + + /* + * Hook into directory updates so that we can receive live updates + * from other writer threads. + */ + struct xfs_dir_hook dhook; + + /* Parent pointer update arguments. */ + struct xfs_parent_args ppargs; + + /* lock for everything below here */ + struct mutex lock; + + /* buffer for the live update functions to use for dirent names */ + struct xfs_name hook_xname; + unsigned char hook_namebuf[MAXNAMELEN]; + + /* + * All path steps observed during this scan. Each of the path + * steps for a particular pathwalk are recorded in sequential + * order in the xfarray. A pathwalk ends either with a step + * pointing to the root directory (success) or pointing to NULLFSINO + * (loop detected, empty dir detected, etc). + */ + struct xfarray *path_steps; + + /* All names observed during this scan. */ + struct xfblob *path_names; + + /* All paths being tracked by this scanner. */ + struct list_head path_list; + + /* Number of paths in path_list. */ + unsigned int nr_paths; + + /* Number of parents found by a pptr scan. */ + unsigned int parents_found; + + /* Have the path data been invalidated by a concurrent update? */ + bool stale:1; + + /* Has the scan been aborted? */ + bool aborted:1; +}; + +#define xchk_dirtree_for_each_path_safe(dl, path, n) \ + list_for_each_entry_safe((path), (n), &(dl)->path_list, list) + +#define xchk_dirtree_for_each_path(dl, path) \ + list_for_each_entry((path), &(dl)->path_list, list) + +static inline bool +xchk_dirtree_parentless(const struct xchk_dirtree *dl) +{ + struct xfs_scrub *sc = dl->sc; + + if (sc->ip == sc->mp->m_rootip) + return true; + if (VFS_I(sc->ip)->i_nlink == 0) + return true; + return false; +} + +int xchk_dirtree_find_paths_to_root(struct xchk_dirtree *dl); +int xchk_dirpath_append(struct xchk_dirtree *dl, struct xfs_inode *ip, + struct xchk_dirpath *path, const struct xfs_name *name, + const struct xfs_parent_rec *pptr); +void xchk_dirtree_evaluate(struct xchk_dirtree *dl, + struct xchk_dirtree_outcomes *oc); + +#endif /* __XFS_SCRUB_DIRTREE_H__ */ |