From patchwork Wed Jan 20 18:28:34 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 367936 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD156C433DB for ; Wed, 20 Jan 2021 18:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69635233FC for ; Wed, 20 Jan 2021 18:33:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391879AbhATScb (ORCPT ); Wed, 20 Jan 2021 13:32:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:51522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404417AbhATS3s (ORCPT ); Wed, 20 Jan 2021 13:29:48 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 864AD2342C; Wed, 20 Jan 2021 18:28:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611167331; bh=ZPy7MsX3VP8mNVh0Wc4o/iMp/H7aNB3koRbPlYWauRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ru2hGep58ZTWV1ml83eSbhzQdoy4hbTv3CSB0er10n4F3QyOJx27P8YPZ7sT7Q2Mo 7ttjz/TOw+zn6S7yhYmRiFDncyakiwbgr2uJaJCgFSdaNoCUV/SAAyiykMvB68q+Xs JjTCqQ1dovoDMU8f6w5QmAisqSjuXzuIkbEqmKptr/MzDuTC0x7v52SxAeQapuyrWo Mzs3NH4vybDg27s30j71kTjabpW4DZEft2WsGmyu4ZaUcbDxJluTQ9yUEXsmodmB/2 Cl93gNZ/VNzRTpM9aKLHo3zX4PpDSEUxzQBxiqVRnKrc0QPen6Rf/pWOjMWaAUlyyA LYBjZvw/E+6Tg== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH v4 04/17] fscrypt: add fscrypt_context_for_new_inode Date: Wed, 20 Jan 2021 13:28:34 -0500 Message-Id: <20210120182847.644850-5-jlayton@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210120182847.644850-1-jlayton@kernel.org> References: <20210120182847.644850-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org CephFS will need to be able to generate a context for a new "prepared" inode. Add a new routine for getting the context out of an in-core inode. Signed-off-by: Jeff Layton --- fs/crypto/policy.c | 34 ++++++++++++++++++++++++++++------ include/linux/fscrypt.h | 1 + 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index a51cef6bd27f..44b4236427ba 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -664,6 +664,31 @@ const union fscrypt_policy *fscrypt_policy_to_inherit(struct inode *dir) return fscrypt_get_dummy_policy(dir->i_sb); } +/** + * fscrypt_context_for_new_inode() - create an encryption context for a new inode + * @ctx: where context should be written + * @inode: inode from which to fetch policy and nonce + * + * Given an in-core "prepared" (via fscrypt_prepare_new_inode) inode, + * generate a new context and write it to ctx. ctx _must_ be at least + * FSCRYPT_SET_CONTEXT_MAX_SIZE bytes. + * + * Returns size of the resulting context or a negative error code. + */ +int fscrypt_context_for_new_inode(void *ctx, struct inode *inode) +{ + struct fscrypt_info *ci = inode->i_crypt_info; + + BUILD_BUG_ON(sizeof(union fscrypt_context) != FSCRYPT_SET_CONTEXT_MAX_SIZE); + + /* fscrypt_prepare_new_inode() should have set up the key already. */ + if (WARN_ON_ONCE(!ci)) + return -ENOKEY; + + return fscrypt_new_context(ctx, &ci->ci_policy, ci->ci_nonce); +} +EXPORT_SYMBOL_GPL(fscrypt_context_for_new_inode); + /** * fscrypt_set_context() - Set the fscrypt context of a new inode * @inode: a new inode @@ -680,12 +705,9 @@ int fscrypt_set_context(struct inode *inode, void *fs_data) union fscrypt_context ctx; int ctxsize; - /* fscrypt_prepare_new_inode() should have set up the key already. */ - if (WARN_ON_ONCE(!ci)) - return -ENOKEY; - - BUILD_BUG_ON(sizeof(ctx) != FSCRYPT_SET_CONTEXT_MAX_SIZE); - ctxsize = fscrypt_new_context(&ctx, &ci->ci_policy, ci->ci_nonce); + ctxsize = fscrypt_context_for_new_inode(&ctx, inode); + if (ctxsize < 0) + return ctxsize; /* * This may be the first time the inode number is available, so do any diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index b5c31baaa8bf..087fa87bca0b 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -178,6 +178,7 @@ int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg); int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *arg); int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg); int fscrypt_has_permitted_context(struct inode *parent, struct inode *child); +int fscrypt_context_for_new_inode(void *ctx, struct inode *inode); int fscrypt_set_context(struct inode *inode, void *fs_data); struct fscrypt_dummy_policy {