diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dcache.h | 2 | ||||
| -rw-r--r-- | include/linux/fscrypt.h | 74 |
2 files changed, 53 insertions, 23 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 73c3a8f90580..f14e587c5d5d 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -211,7 +211,7 @@ struct dentry_operations { #define DCACHE_MAY_FREE 0x00800000 #define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */ -#define DCACHE_ENCRYPTED_WITH_KEY 0x02000000 /* dir is encrypted with a valid key */ +#define DCACHE_ENCRYPTED_NAME 0x02000000 /* Encrypted name (dir key was unavailable) */ #define DCACHE_OP_REAL 0x04000000 #define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */ diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index e5194fc3983e..28c74e0a7231 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -33,6 +33,7 @@ struct fscrypt_name { u32 hash; u32 minor_hash; struct fscrypt_str crypto_buf; + bool is_ciphertext_name; }; #define FSTR_INIT(n, l) { .name = n, .len = l } @@ -79,7 +80,8 @@ struct fscrypt_ctx { static inline bool fscrypt_has_encryption_key(const struct inode *inode) { - return (inode->i_crypt_info != NULL); + /* pairs with cmpxchg_release() in fscrypt_get_encryption_info() */ + return READ_ONCE(inode->i_crypt_info) != NULL; } static inline bool fscrypt_dummy_context_enabled(struct inode *inode) @@ -88,9 +90,21 @@ static inline bool fscrypt_dummy_context_enabled(struct inode *inode) inode->i_sb->s_cop->dummy_context(inode); } +/* + * When d_splice_alias() moves a directory's encrypted alias to its decrypted + * alias as a result of the encryption key being added, DCACHE_ENCRYPTED_NAME + * must be cleared. Note that we don't have to support arbitrary moves of this + * flag because fscrypt doesn't allow encrypted aliases to be the source or + * target of a rename(). + */ +static inline void fscrypt_handle_d_move(struct dentry *dentry) +{ + dentry->d_flags &= ~DCACHE_ENCRYPTED_NAME; +} + /* crypto.c */ extern void fscrypt_enqueue_decrypt_work(struct work_struct *); -extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t); +extern struct fscrypt_ctx *fscrypt_get_ctx(gfp_t); extern void fscrypt_release_ctx(struct fscrypt_ctx *); extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, @@ -114,6 +128,7 @@ extern int fscrypt_inherit_context(struct inode *, struct inode *, /* keyinfo.c */ extern int fscrypt_get_encryption_info(struct inode *); extern void fscrypt_put_encryption_info(struct inode *); +extern void fscrypt_free_inode(struct inode *); /* fname.c */ extern int fscrypt_setup_filename(struct inode *, const struct qstr *, @@ -214,13 +229,15 @@ extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t, /* hooks.c */ extern int fscrypt_file_open(struct inode *inode, struct file *filp); -extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir); +extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, + struct dentry *dentry); extern int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags); -extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry); +extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, + struct fscrypt_name *fname); extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, unsigned int max_len, struct fscrypt_str *disk_link); @@ -242,13 +259,16 @@ static inline bool fscrypt_dummy_context_enabled(struct inode *inode) return false; } +static inline void fscrypt_handle_d_move(struct dentry *dentry) +{ +} + /* crypto.c */ static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work) { } -static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode, - gfp_t gfp_flags) +static inline struct fscrypt_ctx *fscrypt_get_ctx(gfp_t gfp_flags) { return ERR_PTR(-EOPNOTSUPP); } @@ -322,6 +342,10 @@ static inline void fscrypt_put_encryption_info(struct inode *inode) return; } +static inline void fscrypt_free_inode(struct inode *inode) +{ +} + /* fname.c */ static inline int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname, @@ -330,7 +354,7 @@ static inline int fscrypt_setup_filename(struct inode *dir, if (IS_ENCRYPTED(dir)) return -EOPNOTSUPP; - memset(fname, 0, sizeof(struct fscrypt_name)); + memset(fname, 0, sizeof(*fname)); fname->usr_fname = iname; fname->disk_name.name = (unsigned char *)iname->name; fname->disk_name.len = iname->len; @@ -401,8 +425,8 @@ static inline int fscrypt_file_open(struct inode *inode, struct file *filp) return 0; } -static inline int __fscrypt_prepare_link(struct inode *inode, - struct inode *dir) +static inline int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, + struct dentry *dentry) { return -EOPNOTSUPP; } @@ -417,7 +441,8 @@ static inline int __fscrypt_prepare_rename(struct inode *old_dir, } static inline int __fscrypt_prepare_lookup(struct inode *dir, - struct dentry *dentry) + struct dentry *dentry, + struct fscrypt_name *fname) { return -EOPNOTSUPP; } @@ -497,7 +522,7 @@ static inline int fscrypt_prepare_link(struct dentry *old_dentry, struct dentry *dentry) { if (IS_ENCRYPTED(dir)) - return __fscrypt_prepare_link(d_inode(old_dentry), dir); + return __fscrypt_prepare_link(d_inode(old_dentry), dir, dentry); return 0; } @@ -538,27 +563,32 @@ static inline int fscrypt_prepare_rename(struct inode *old_dir, * fscrypt_prepare_lookup - prepare to lookup a name in a possibly-encrypted directory * @dir: directory being searched * @dentry: filename being looked up - * @flags: lookup flags + * @fname: (output) the name to use to search the on-disk directory * - * Prepare for ->lookup() in a directory which may be encrypted. Lookups can be - * done with or without the directory's encryption key; without the key, + * Prepare for ->lookup() in a directory which may be encrypted by determining + * the name that will actually be used to search the directory on-disk. Lookups + * can be done with or without the directory's encryption key; without the key, * filenames are presented in encrypted form. Therefore, we'll try to set up * the directory's encryption key, but even without it the lookup can continue. * - * To allow invalidating stale dentries if the directory's encryption key is - * added later, we also install a custom ->d_revalidate() method and use the - * DCACHE_ENCRYPTED_WITH_KEY flag to indicate whether a given dentry is a - * plaintext name (flag set) or a ciphertext name (flag cleared). + * This also installs a custom ->d_revalidate() method which will invalidate the + * dentry if it was created without the key and the key is later added. * - * Return: 0 on success, -errno if a problem occurred while setting up the - * encryption key + * Return: 0 on success; -ENOENT if key is unavailable but the filename isn't a + * correctly formed encoded ciphertext name, so a negative dentry should be + * created; or another -errno code. */ static inline int fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, - unsigned int flags) + struct fscrypt_name *fname) { if (IS_ENCRYPTED(dir)) - return __fscrypt_prepare_lookup(dir, dentry); + return __fscrypt_prepare_lookup(dir, dentry, fname); + + memset(fname, 0, sizeof(*fname)); + fname->usr_fname = &dentry->d_name; + fname->disk_name.name = (unsigned char *)dentry->d_name.name; + fname->disk_name.len = dentry->d_name.len; return 0; } |