/* SPDX-License-Identifier: GPL-2.0-only */ /* * * Copyright (C) 2011 Novell Inc. */ #include <linux/kernel.h> #include <linux/uuid.h> #include <linux/fs.h> #include <linux/fsverity.h> #include <linux/namei.h> #include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> #include "ovl_entry.h" #undef pr_fmt #define pr_fmt(fmt) … enum ovl_path_type { … }; #define OVL_TYPE_UPPER(type) … #define OVL_TYPE_MERGE(type) … #define OVL_TYPE_ORIGIN(type) … #define OVL_XATTR_NAMESPACE … #define OVL_XATTR_TRUSTED_PREFIX … #define OVL_XATTR_TRUSTED_PREFIX_LEN … #define OVL_XATTR_USER_PREFIX … #define OVL_XATTR_USER_PREFIX_LEN … #define OVL_XATTR_ESCAPE_PREFIX … #define OVL_XATTR_ESCAPE_PREFIX_LEN … #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX … #define OVL_XATTR_ESCAPE_TRUSTED_PREFIX_LEN … #define OVL_XATTR_ESCAPE_USER_PREFIX … #define OVL_XATTR_ESCAPE_USER_PREFIX_LEN … enum ovl_xattr { … }; enum ovl_inode_flag { … }; enum ovl_entry_flag { … }; enum { … }; enum { … }; enum { … }; enum { … }; /* * The tuple (fh,uuid) is a universal unique identifier for a copy up origin, * where: * origin.fh - exported file handle of the lower file * origin.uuid - uuid of the lower filesystem */ #define OVL_FH_VERSION … #define OVL_FH_MAGIC … /* CPU byte order required for fid decoding: */ #define OVL_FH_FLAG_BIG_ENDIAN … #define OVL_FH_FLAG_ANY_ENDIAN … /* Is the real inode encoded in fid an upper inode? */ #define OVL_FH_FLAG_PATH_UPPER … #define OVL_FH_FLAG_ALL … #if defined(__LITTLE_ENDIAN) #define OVL_FH_FLAG_CPU_ENDIAN … #elif defined(__BIG_ENDIAN) #define OVL_FH_FLAG_CPU_ENDIAN … #else #error Endianness not defined #endif /* The type used to be returned by overlay exportfs for misaligned fid */ #define OVL_FILEID_V0 … /* The type returned by overlay exportfs for 32bit aligned fid */ #define OVL_FILEID_V1 … /* On-disk format for "origin" file handle */ struct ovl_fb { … } __packed; /* In-memory and on-wire format for overlay file handle */ struct ovl_fh { … } __packed; #define OVL_FH_WIRE_OFFSET … #define OVL_FH_LEN(fh) … #define OVL_FH_FID_OFFSET … /* On-disk format for "metacopy" xattr (if non-zero size) */ struct ovl_metacopy { … } __packed; #define OVL_METACOPY_MAX_SIZE … #define OVL_METACOPY_MIN_SIZE … #define OVL_METACOPY_INIT … static inline int ovl_metadata_digest_size(const struct ovl_metacopy *metacopy) { … } /* No atime modification on underlying */ #define OVL_OPEN_FLAGS … extern const char *const ovl_xattr_table[][2]; static inline const char *ovl_xattr(struct ovl_fs *ofs, enum ovl_xattr ox) { … } /* * When changing ownership of an upper object map the intended ownership * according to the upper layer's idmapping. When an upper mount idmaps files * that are stored on-disk as owned by id 1001 to id 1000 this means stat on * this object will report it as being owned by id 1000 when calling stat via * the upper mount. * In order to change ownership of an object so stat reports id 1000 when * called on an idmapped upper mount the value written to disk - i.e., the * value stored in ia_*id - must 1001. The mount mapping helper will thus take * care to map 1000 to 1001. * The mnt idmapping helpers are nops if the upper layer isn't idmapped. */ static inline int ovl_do_notify_change(struct ovl_fs *ofs, struct dentry *upperdentry, struct iattr *attr) { … } static inline int ovl_do_rmdir(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { … } static inline int ovl_do_unlink(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { … } static inline int ovl_do_link(struct ovl_fs *ofs, struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) { … } static inline int ovl_do_create(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, umode_t mode) { … } static inline int ovl_do_mkdir(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, umode_t mode) { … } static inline int ovl_do_mknod(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { … } static inline int ovl_do_symlink(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry, const char *oldname) { … } static inline ssize_t ovl_do_getxattr(const struct path *path, const char *name, void *value, size_t size) { … } static inline ssize_t ovl_getxattr_upper(struct ovl_fs *ofs, struct dentry *upperdentry, enum ovl_xattr ox, void *value, size_t size) { … } static inline ssize_t ovl_path_getxattr(struct ovl_fs *ofs, const struct path *path, enum ovl_xattr ox, void *value, size_t size) { … } static inline int ovl_do_setxattr(struct ovl_fs *ofs, struct dentry *dentry, const char *name, const void *value, size_t size, int flags) { … } static inline int ovl_setxattr(struct ovl_fs *ofs, struct dentry *dentry, enum ovl_xattr ox, const void *value, size_t size) { … } static inline int ovl_do_removexattr(struct ovl_fs *ofs, struct dentry *dentry, const char *name) { … } static inline int ovl_removexattr(struct ovl_fs *ofs, struct dentry *dentry, enum ovl_xattr ox) { … } static inline int ovl_do_set_acl(struct ovl_fs *ofs, struct dentry *dentry, const char *acl_name, struct posix_acl *acl) { … } static inline int ovl_do_remove_acl(struct ovl_fs *ofs, struct dentry *dentry, const char *acl_name) { … } static inline int ovl_do_rename(struct ovl_fs *ofs, struct inode *olddir, struct dentry *olddentry, struct inode *newdir, struct dentry *newdentry, unsigned int flags) { … } static inline int ovl_do_whiteout(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { … } static inline struct file *ovl_do_tmpfile(struct ovl_fs *ofs, struct dentry *dentry, umode_t mode) { … } static inline struct dentry *ovl_lookup_upper(struct ovl_fs *ofs, const char *name, struct dentry *base, int len) { … } static inline bool ovl_open_flags_need_copy_up(int flags) { … } static inline int ovl_do_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { … } /* util.c */ int ovl_get_write_access(struct dentry *dentry); void ovl_put_write_access(struct dentry *dentry); void ovl_start_write(struct dentry *dentry); void ovl_end_write(struct dentry *dentry); int ovl_want_write(struct dentry *dentry); void ovl_drop_write(struct dentry *dentry); struct dentry *ovl_workdir(struct dentry *dentry); const struct cred *ovl_override_creds(struct super_block *sb); static inline const struct cred *ovl_creds(struct super_block *sb) { … } int ovl_can_decode_fh(struct super_block *sb); struct dentry *ovl_indexdir(struct super_block *sb); bool ovl_index_all(struct super_block *sb); bool ovl_verify_lower(struct super_block *sb); struct ovl_path *ovl_stack_alloc(unsigned int n); void ovl_stack_cpy(struct ovl_path *dst, struct ovl_path *src, unsigned int n); void ovl_stack_put(struct ovl_path *stack, unsigned int n); void ovl_stack_free(struct ovl_path *stack, unsigned int n); struct ovl_entry *ovl_alloc_entry(unsigned int numlower); void ovl_free_entry(struct ovl_entry *oe); bool ovl_dentry_remote(struct dentry *dentry); void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *realdentry); void ovl_dentry_init_reval(struct dentry *dentry, struct dentry *upperdentry, struct ovl_entry *oe); void ovl_dentry_init_flags(struct dentry *dentry, struct dentry *upperdentry, struct ovl_entry *oe, unsigned int mask); bool ovl_dentry_weird(struct dentry *dentry); enum ovl_path_type ovl_path_type(struct dentry *dentry); void ovl_path_upper(struct dentry *dentry, struct path *path); void ovl_path_lower(struct dentry *dentry, struct path *path); void ovl_path_lowerdata(struct dentry *dentry, struct path *path); struct inode *ovl_i_path_real(struct inode *inode, struct path *path); enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); enum ovl_path_type ovl_path_realdata(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_lowerdata(struct dentry *dentry); int ovl_dentry_set_lowerdata(struct dentry *dentry, struct ovl_path *datapath); const struct ovl_layer *ovl_i_layer_lower(struct inode *inode); const struct ovl_layer *ovl_layer_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); struct dentry *ovl_i_dentry_upper(struct inode *inode); struct inode *ovl_inode_upper(struct inode *inode); struct inode *ovl_inode_lower(struct inode *inode); struct inode *ovl_inode_lowerdata(struct inode *inode); struct inode *ovl_inode_real(struct inode *inode); struct inode *ovl_inode_realdata(struct inode *inode); const char *ovl_lowerdata_redirect(struct inode *inode); struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry); void ovl_dentry_clear_flag(unsigned long flag, struct dentry *dentry); bool ovl_dentry_test_flag(unsigned long flag, struct dentry *dentry); bool ovl_dentry_is_opaque(struct dentry *dentry); bool ovl_dentry_is_whiteout(struct dentry *dentry); void ovl_dentry_set_opaque(struct dentry *dentry); bool ovl_dentry_has_xwhiteouts(struct dentry *dentry); void ovl_dentry_set_xwhiteouts(struct dentry *dentry); void ovl_layer_set_xwhiteouts(struct ovl_fs *ofs, const struct ovl_layer *layer); bool ovl_dentry_has_upper_alias(struct dentry *dentry); void ovl_dentry_set_upper_alias(struct dentry *dentry); bool ovl_dentry_needs_data_copy_up(struct dentry *dentry, int flags); bool ovl_dentry_needs_data_copy_up_locked(struct dentry *dentry, int flags); bool ovl_has_upperdata(struct inode *inode); void ovl_set_upperdata(struct inode *inode); const char *ovl_dentry_get_redirect(struct dentry *dentry); void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); void ovl_dir_modified(struct dentry *dentry, bool impurity); u64 ovl_inode_version_get(struct inode *inode); bool ovl_is_whiteout(struct dentry *dentry); bool ovl_path_is_whiteout(struct ovl_fs *ofs, const struct path *path); struct file *ovl_path_open(const struct path *path, int flags); int ovl_copy_up_start(struct dentry *dentry, int flags); void ovl_copy_up_end(struct dentry *dentry); bool ovl_already_copied_up(struct dentry *dentry, int flags); char ovl_get_dir_xattr_val(struct ovl_fs *ofs, const struct path *path, enum ovl_xattr ox); bool ovl_path_check_origin_xattr(struct ovl_fs *ofs, const struct path *path); bool ovl_path_check_xwhiteout_xattr(struct ovl_fs *ofs, const struct path *path); bool ovl_init_uuid_xattr(struct super_block *sb, struct ovl_fs *ofs, const struct path *upperpath); static inline bool ovl_upper_is_whiteout(struct ovl_fs *ofs, struct dentry *upperdentry) { … } static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs, struct dentry *upperdentry) { … } int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry, enum ovl_xattr ox, const void *value, size_t size, int xerr); int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); bool ovl_inuse_trylock(struct dentry *dentry); void ovl_inuse_unlock(struct dentry *dentry); bool ovl_is_inuse(struct dentry *dentry); bool ovl_need_index(struct dentry *dentry); int ovl_nlink_start(struct dentry *dentry); void ovl_nlink_end(struct dentry *dentry); int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir); int ovl_check_metacopy_xattr(struct ovl_fs *ofs, const struct path *path, struct ovl_metacopy *data); int ovl_set_metacopy_xattr(struct ovl_fs *ofs, struct dentry *d, struct ovl_metacopy *metacopy); bool ovl_is_metacopy_dentry(struct dentry *dentry); char *ovl_get_redirect_xattr(struct ovl_fs *ofs, const struct path *path, int padding); int ovl_ensure_verity_loaded(struct path *path); int ovl_get_verity_xattr(struct ovl_fs *ofs, const struct path *path, u8 *digest_buf, int *buf_length); int ovl_validate_verity(struct ovl_fs *ofs, struct path *metapath, struct path *datapath); int ovl_get_verity_digest(struct ovl_fs *ofs, struct path *src, struct ovl_metacopy *metacopy); int ovl_sync_status(struct ovl_fs *ofs); static inline void ovl_set_flag(unsigned long flag, struct inode *inode) { … } static inline void ovl_clear_flag(unsigned long flag, struct inode *inode) { … } static inline bool ovl_test_flag(unsigned long flag, struct inode *inode) { … } static inline bool ovl_is_impuredir(struct super_block *sb, struct dentry *upperdentry) { … } static inline char ovl_get_opaquedir_val(struct ovl_fs *ofs, const struct path *path) { … } static inline bool ovl_redirect_follow(struct ovl_fs *ofs) { … } static inline bool ovl_redirect_dir(struct ovl_fs *ofs) { … } static inline bool ovl_origin_uuid(struct ovl_fs *ofs) { … } static inline bool ovl_has_fsid(struct ovl_fs *ofs) { … } /* * With xino=auto, we do best effort to keep all inodes on same st_dev and * d_ino consistent with st_ino. * With xino=on, we do the same effort but we warn if we failed. */ static inline bool ovl_xino_warn(struct ovl_fs *ofs) { … } /* * To avoid regressions in existing setups with overlay lower offline changes, * we allow lower changes only if none of the new features are used. */ static inline bool ovl_allow_offline_changes(struct ovl_fs *ofs) { … } /* All layers on same fs? */ static inline bool ovl_same_fs(struct ovl_fs *ofs) { … } /* All overlay inodes have same st_dev? */ static inline bool ovl_same_dev(struct ovl_fs *ofs) { … } static inline unsigned int ovl_xino_bits(struct ovl_fs *ofs) { … } static inline void ovl_inode_lock(struct inode *inode) { … } static inline int ovl_inode_lock_interruptible(struct inode *inode) { … } static inline void ovl_inode_unlock(struct inode *inode) { … } /* namei.c */ int ovl_check_fb_len(struct ovl_fb *fb, int fb_len); static inline int ovl_check_fh_len(struct ovl_fh *fh, int fh_len) { … } struct dentry *ovl_decode_real_fh(struct ovl_fs *ofs, struct ovl_fh *fh, struct vfsmount *mnt, bool connected); int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected, struct dentry *upperdentry, struct ovl_path **stackp); int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry, enum ovl_xattr ox, const struct ovl_fh *fh, bool is_upper, bool set); int ovl_verify_origin_xattr(struct ovl_fs *ofs, struct dentry *dentry, enum ovl_xattr ox, struct dentry *real, bool is_upper, bool set); struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index, bool connected); int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index); int ovl_get_index_name_fh(const struct ovl_fh *fh, struct qstr *name); int ovl_get_index_name(struct ovl_fs *ofs, struct dentry *origin, struct qstr *name); struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh); struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper, struct dentry *origin, bool verify); int ovl_path_next(int idx, struct dentry *dentry, struct path *path, const struct ovl_layer **layer); int ovl_verify_lowerdata(struct dentry *dentry); struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags); bool ovl_lower_positive(struct dentry *dentry); static inline int ovl_verify_origin_fh(struct ovl_fs *ofs, struct dentry *upper, const struct ovl_fh *fh, bool set) { … } static inline int ovl_verify_origin(struct ovl_fs *ofs, struct dentry *upper, struct dentry *origin, bool set) { … } static inline int ovl_verify_upper(struct ovl_fs *ofs, struct dentry *index, struct dentry *upper, bool set) { … } /* readdir.c */ extern const struct file_operations ovl_dir_operations; struct file *ovl_dir_real_file(const struct file *file, bool want_upper); int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper, struct list_head *list); void ovl_cache_free(struct list_head *list); void ovl_dir_cache_free(struct inode *inode); int ovl_check_d_type_supported(const struct path *realpath); int ovl_workdir_cleanup(struct ovl_fs *ofs, struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); int ovl_indexdir_cleanup(struct ovl_fs *ofs); /* * Can we iterate real dir directly? * * Non-merge dir may contain whiteouts from a time it was a merge upper, before * lower dir was removed under it and possibly before it was rotated from upper * to lower layer. */ static inline bool ovl_dir_is_real(struct inode *dir) { … } /* inode.c */ int ovl_set_nlink_upper(struct dentry *dentry); int ovl_set_nlink_lower(struct dentry *dentry); unsigned int ovl_get_nlink(struct ovl_fs *ofs, struct dentry *lowerdentry, struct dentry *upperdentry, unsigned int fallback); int ovl_permission(struct mnt_idmap *idmap, struct inode *inode, int mask); #ifdef CONFIG_FS_POSIX_ACL struct posix_acl *do_ovl_get_acl(struct mnt_idmap *idmap, struct inode *inode, int type, bool rcu, bool noperm); static inline struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, bool rcu) { … } static inline struct posix_acl *ovl_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, int type) { … } int ovl_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, struct posix_acl *acl, int type); struct posix_acl *ovl_get_acl_path(const struct path *path, const char *acl_name, bool noperm); #else #define ovl_get_inode_acl … #define ovl_get_acl … #define ovl_set_acl … static inline struct posix_acl *ovl_get_acl_path(const struct path *path, const char *acl_name, bool noperm) { return NULL; } #endif int ovl_update_time(struct inode *inode, int flags); bool ovl_is_private_xattr(struct super_block *sb, const char *name); struct ovl_inode_params { … }; void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip, unsigned long ino, int fsid); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, bool is_upper); bool ovl_lookup_trap_inode(struct super_block *sb, struct dentry *dir); struct inode *ovl_get_trap_inode(struct super_block *sb, struct dentry *dir); struct inode *ovl_get_inode(struct super_block *sb, struct ovl_inode_params *oip); void ovl_copyattr(struct inode *to); /* vfs inode flags copied from real to ovl inode */ #define OVL_COPY_I_FLAGS_MASK … /* vfs inode flags read from overlay.protattr xattr to ovl inode */ #define OVL_PROT_I_FLAGS_MASK … /* * fileattr flags copied from lower to upper inode on copy up. * We cannot copy up immutable/append-only flags, because that would prevent * linking temp inode to upper dir, so we store them in xattr instead. */ #define OVL_COPY_FS_FLAGS_MASK … #define OVL_COPY_FSX_FLAGS_MASK … #define OVL_PROT_FS_FLAGS_MASK … #define OVL_PROT_FSX_FLAGS_MASK … void ovl_check_protattr(struct inode *inode, struct dentry *upper); int ovl_set_protattr(struct inode *inode, struct dentry *upper, struct fileattr *fa); static inline void ovl_copyflags(struct inode *from, struct inode *to) { … } /* dir.c */ extern const struct inode_operations ovl_dir_inode_operations; int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); struct ovl_cattr { … }; #define OVL_CATTR(m) … int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir, struct dentry **newdentry, umode_t mode); struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir, struct dentry *newdentry, struct ovl_cattr *attr); int ovl_cleanup(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir); struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir, struct ovl_cattr *attr); /* file.c */ extern const struct file_operations ovl_file_operations; int ovl_real_fileattr_get(const struct path *realpath, struct fileattr *fa); int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa); int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa); int ovl_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, struct fileattr *fa); /* copy_up.c */ int ovl_copy_up(struct dentry *dentry); int ovl_copy_up_with_data(struct dentry *dentry); int ovl_maybe_copy_up(struct dentry *dentry, int flags); int ovl_copy_xattr(struct super_block *sb, const struct path *path, struct dentry *new); int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upper, struct kstat *stat); struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, bool is_upper); struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin); int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, struct dentry *upper); /* export.c */ extern const struct export_operations ovl_export_operations; extern const struct export_operations ovl_export_fid_operations; /* super.c */ int ovl_fill_super(struct super_block *sb, struct fs_context *fc); /* Will this overlay be forced to mount/remount ro? */ static inline bool ovl_force_readonly(struct ovl_fs *ofs) { … } /* xattr.c */ const struct xattr_handler * const *ovl_xattr_handlers(struct ovl_fs *ofs); int ovl_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *attr); int ovl_getattr(struct mnt_idmap *idmap, const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
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