diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fscrypt.h | 27 | ||||
| -rw-r--r-- | include/linux/fscrypt_notsupp.h | 6 | ||||
| -rw-r--r-- | include/linux/fscrypt_supp.h | 1 |
3 files changed, 34 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 */ diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index 162da6517ac4..d7d1039eb6b5 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -186,4 +186,10 @@ 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) +{ + return -EOPNOTSUPP; +} + #endif /* _LINUX_FSCRYPT_NOTSUPP_H */ diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h index fd2f6decaee4..80706283da75 100644 --- a/include/linux/fscrypt_supp.h +++ b/include/linux/fscrypt_supp.h @@ -145,5 +145,6 @@ 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); #endif /* _LINUX_FSCRYPT_SUPP_H */ |