diff options
Diffstat (limited to 'include/linux/fscrypt.h')
| -rw-r--r-- | include/linux/fscrypt.h | 116 |
1 files changed, 112 insertions, 4 deletions
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 2ea1387bb497..e912ed9141d9 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -47,27 +47,128 @@ struct fscrypt_name { #define FSCRYPT_SET_CONTEXT_MAX_SIZE 40 #ifdef CONFIG_FS_ENCRYPTION + /* - * fscrypt superblock flags + * If set, the fscrypt bounce page pool won't be allocated (unless another + * filesystem needs it). Set this if the filesystem always uses its own bounce + * pages for writes and therefore won't need the fscrypt bounce page pool. */ #define FS_CFLG_OWN_PAGES (1U << 1) -/* - * crypto operations for filesystems - */ +/* Crypto operations for filesystems */ struct fscrypt_operations { + + /* Set of optional flags; see above for allowed flags */ unsigned int flags; + + /* + * If set, this is a filesystem-specific key description prefix that + * will be accepted for "logon" keys for v1 fscrypt policies, in + * addition to the generic prefix "fscrypt:". This functionality is + * deprecated, so new filesystems shouldn't set this field. + */ const char *key_prefix; + + /* + * Get the fscrypt context of the given inode. + * + * @inode: the inode whose context to get + * @ctx: the buffer into which to get the context + * @len: length of the @ctx buffer in bytes + * + * Return: On success, returns the length of the context in bytes; this + * may be less than @len. On failure, returns -ENODATA if the + * inode doesn't have a context, -ERANGE if the context is + * longer than @len, or another -errno code. + */ int (*get_context)(struct inode *inode, void *ctx, size_t len); + + /* + * Set an fscrypt context on the given inode. + * + * @inode: the inode whose context to set. The inode won't already have + * an fscrypt context. + * @ctx: the context to set + * @len: length of @ctx in bytes (at most FSCRYPT_SET_CONTEXT_MAX_SIZE) + * @fs_data: If called from fscrypt_set_context(), this will be the + * value the filesystem passed to fscrypt_set_context(). + * Otherwise (i.e. when called from + * FS_IOC_SET_ENCRYPTION_POLICY) this will be NULL. + * + * i_rwsem will be held for write. + * + * Return: 0 on success, -errno on failure. + */ int (*set_context)(struct inode *inode, const void *ctx, size_t len, void *fs_data); + + /* + * Get the dummy fscrypt policy in use on the filesystem (if any). + * + * Filesystems only need to implement this function if they support the + * test_dummy_encryption mount option. + * + * Return: A pointer to the dummy fscrypt policy, if the filesystem is + * mounted with test_dummy_encryption; otherwise NULL. + */ const union fscrypt_policy *(*get_dummy_policy)(struct super_block *sb); + + /* + * Check whether a directory is empty. i_rwsem will be held for write. + */ bool (*empty_dir)(struct inode *inode); + + /* The filesystem's maximum ciphertext filename length, in bytes */ unsigned int max_namelen; + + /* + * Check whether the filesystem's inode numbers and UUID are stable, + * meaning that they will never be changed even by offline operations + * such as filesystem shrinking and therefore can be used in the + * encryption without the possibility of files becoming unreadable. + * + * Filesystems only need to implement this function if they want to + * support the FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags. These + * flags are designed to work around the limitations of UFS and eMMC + * inline crypto hardware, and they shouldn't be used in scenarios where + * such hardware isn't being used. + * + * Leaving this NULL is equivalent to always returning false. + */ bool (*has_stable_inodes)(struct super_block *sb); + + /* + * Get the number of bits that the filesystem uses to represent inode + * numbers and file logical block numbers. + * + * By default, both of these are assumed to be 64-bit. This function + * can be implemented to declare that either or both of these numbers is + * shorter, which may allow the use of the + * FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags and/or the use of + * inline crypto hardware whose maximum DUN length is less than 64 bits + * (e.g., eMMC v5.2 spec compliant hardware). This function only needs + * to be implemented if support for one of these features is needed. + */ void (*get_ino_and_lblk_bits)(struct super_block *sb, int *ino_bits_ret, int *lblk_bits_ret); + + /* + * Return the number of block devices to which the filesystem may write + * encrypted file contents. + * + * If the filesystem can use multiple block devices (other than block + * devices that aren't used for encrypted file contents, such as + * external journal devices), and wants to support inline encryption, + * then it must implement this function. Otherwise it's not needed. + */ int (*get_num_devices)(struct super_block *sb); + + /* + * If ->get_num_devices() returns a value greater than 1, then this + * function is called to get the array of request_queues that the + * filesystem is using -- one per block device. (There may be duplicate + * entries in this array, as block devices can share a request_queue.) + */ void (*get_devices)(struct super_block *sb, struct request_queue **devs); }; @@ -253,6 +354,7 @@ int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, unsigned int max_size, struct delayed_call *done); +int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat); static inline void fscrypt_set_ops(struct super_block *sb, const struct fscrypt_operations *s_cop) { @@ -583,6 +685,12 @@ static inline const char *fscrypt_get_symlink(struct inode *inode, return ERR_PTR(-EOPNOTSUPP); } +static inline int fscrypt_symlink_getattr(const struct path *path, + struct kstat *stat) +{ + return -EOPNOTSUPP; +} + static inline void fscrypt_set_ops(struct super_block *sb, const struct fscrypt_operations *s_cop) { |