From mboxrd@z Thu Jan 1 00:00:00 1970 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=-16.7 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 autolearn=unavailable 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 E0089C07E9C for ; Sun, 11 Jul 2021 17:44:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C60FD60E08 for ; Sun, 11 Jul 2021 17:44:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233028AbhGKRrf (ORCPT ); Sun, 11 Jul 2021 13:47:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:41714 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232999AbhGKRrd (ORCPT ); Sun, 11 Jul 2021 13:47:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9CAFD61153; Sun, 11 Jul 2021 17:44:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626025486; bh=AunWFpEBTvppLmOE8HRvKrazR9bLTM9rMms+fo8lf5A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IMOXvMsNFASFp+m49G6NkcW/xN86yHCUBIoCL4OZFHcKFk4VcSVQqDfAey9k+xpNE dfReM1wY9RNgloRj1VJ9UHOxz0nZB7HCGTmTeBVKTk4wbWWOKXgkxa3/mez88nu7Au 0JWZMsW/nd+K4qabVTVaYz42wdomiyFlIs2AI53jNMM2JmmyW2WPCYumCUHv0A7T83 rw6GXxAXHq2RB0FKkfkx5aVDtHkaUYvVvgHtFTHMCkmSJQuHdzNCux4mnp16P1+jCd VVf+2EKZ3tPti/cfY5Moz6mZ8C5NB0P+N8/nr2QY6uiBGB5yMi9dGAa/vRTAHQRSza 5gEO7U4+7f5BQ== Date: Sun, 11 Jul 2021 12:44:43 -0500 From: Eric Biggers To: Jeff Layton Cc: ceph-devel@vger.kernel.org, lhenriques@suse.de, xiubli@redhat.com, linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, dhowells@redhat.com Subject: Re: [RFC PATCH v7 04/24] fscrypt: add fscrypt_context_for_new_inode Message-ID: References: <20210625135834.12934-1-jlayton@kernel.org> <20210625135834.12934-5-jlayton@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210625135834.12934-5-jlayton@kernel.org> Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Fri, Jun 25, 2021 at 09:58:14AM -0400, Jeff Layton wrote: > Most filesystems just call fscrypt_set_context on new inodes, which > usually causes a setxattr. That's a bit late for ceph, which can send > along a full set of attributes with the create request. > > Doing so allows it to avoid race windows that where the new inode could > be seen by other clients without the crypto context attached. It also > avoids the separate round trip to the server. > > Refactor the fscrypt code a bit to allow us to create a new crypto > context, attach it to the inode, and write it to the buffer, but without > calling set_context on it. ceph can later use this to marshal the > context into the attributes we send along with the create request. > > 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 ed3d623724cd..6a895a31560f 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) This generates a kerneldoc warning because "Returns" should be "Return:". - Eric