fscrypt: new helper function - fscrypt_require_key() (d293c3e4) · Commits · 戴 / test

Add a helper function which checks if an inode is encrypted, and if so, tries to set up its encryption key. This is a pattern which is duplicated in multiple places in each of ext4, f2fs, and ubifs --- for example, when a regular file is asked to be opened or truncated. Acked-by:

Dave Chinner <dchinner@redhat.com> Signed-off-by:

Eric Biggers <ebiggers@google.com> Signed-off-by:

Theodore Ts'o <tytso@mit.edu>

include/linux/fscrypt.h

+25 −0

Original line number	Diff line number	Diff line
		@@ -151,5 +151,30 @@ static inline bool fscrypt_has_encryption_key(const struct inode *inode)
		#include <linux/fscrypt_notsupp.h>
		#endif /* __FS_HAS_ENCRYPTION */

		/**
		* fscrypt_require_key - require an inode's encryption key
		* @inode: the inode we need the key for
		*
		* If the inode is encrypted, set up its encryption key if not already done.
		* Then require that the key be present and return -ENOKEY otherwise.
		*
		* No locks are needed, and the key will live as long as the struct inode --- so
		* it won't go away from under you.
		*
		* Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
		* if a problem occurred while setting up the encryption key.
		*/
		static inline int fscrypt_require_key(struct inode *inode)
		{
		if (IS_ENCRYPTED(inode)) {
		int err = fscrypt_get_encryption_info(inode);

		if (err)
		return err;
		if (!fscrypt_has_encryption_key(inode))
		return -ENOKEY;
		}
		return 0;
		}

		#endif /* _LINUX_FSCRYPT_H */

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