fscrypt: new helper function - fscrypt_prepare_link() (0ea87a96) · Commits · 戴 / test

fs/crypto/hooks.c

+15 −0

Original line number	Diff line number	Diff line
		@@ -47,3 +47,18 @@ int fscrypt_file_open(struct inode inode, struct file filp)
		return err;
		}
		EXPORT_SYMBOL_GPL(fscrypt_file_open);

		int __fscrypt_prepare_link(struct inode inode, struct inode dir)
		{
		int err;

		err = fscrypt_require_key(dir);
		if (err)
		return err;

		if (!fscrypt_has_permitted_context(dir, inode))
		return -EPERM;

		return 0;
		}
		EXPORT_SYMBOL_GPL(__fscrypt_prepare_link);

+27 −0

Original line number	Diff line number	Diff line
		@@ -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 */

+6 −0

Original line number	Diff line number	Diff line
		@@ -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 */

+1 −0

Original line number	Diff line number	Diff line
		@@ -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 */