From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Biggers Subject: [PATCH v2 06/11] fscrypt: new helper function - fscrypt_require_key() Date: Mon, 9 Oct 2017 12:15:39 -0700 Message-ID: <20171009191544.43656-7-ebiggers3@gmail.com> References: <20171009191544.43656-1-ebiggers3@gmail.com> Return-path: In-Reply-To: <20171009191544.43656-1-ebiggers3@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org To: linux-fscrypt@vger.kernel.org, "Theodore Y . Ts'o" Cc: Jaegeuk Kim , linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, Eric Biggers List-Id: linux-f2fs-devel.lists.sourceforge.net From: Eric Biggers 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 Signed-off-by: Eric Biggers --- include/linux/fscrypt.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index d58e6a90cfe4..b3e2a5f93415 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -151,5 +151,30 @@ static inline bool fscrypt_has_encryption_key(const struct inode *inode) #include #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 */ -- 2.14.2.920.gcf0c67979c-goog