diff options
Diffstat (limited to 'include/linux/fscrypt.h')
| -rw-r--r-- | include/linux/fscrypt.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index b3e2a5f93415..9c9a53f99327 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -177,4 +177,31 @@ static inline int fscrypt_require_key(struct inode *inode) return 0; } +/** + * fscrypt_prepare_link - prepare to link an inode into a possibly-encrypted directory + * @old_dentry: an existing dentry for the inode being linked + * @dir: the target directory + * @dentry: negative dentry for the target filename + * + * A new link can only be added to an encrypted directory if the directory's + * encryption key is available --- since otherwise we'd have no way to encrypt + * the filename. Therefore, we first set up the directory's encryption key (if + * not already done) and return an error if it's unavailable. + * + * We also verify that the link will not violate the constraint that all files + * in an encrypted directory tree use the same encryption policy. + * + * Return: 0 on success, -ENOKEY if the directory's encryption key is missing, + * -EPERM if the link would result in an inconsistent encryption policy, or + * another -errno code. + */ +static inline int fscrypt_prepare_link(struct dentry *old_dentry, + struct inode *dir, + struct dentry *dentry) +{ + if (IS_ENCRYPTED(dir)) + return __fscrypt_prepare_link(d_inode(old_dentry), dir); + return 0; +} + #endif /* _LINUX_FSCRYPT_H */ |