From patchwork Thu Aug 26 16:20:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 12460121 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=-19.7 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,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 0FB1CC4320A for ; Thu, 26 Aug 2021 16:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB41561175 for ; Thu, 26 Aug 2021 16:20:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243172AbhHZQVY (ORCPT ); Thu, 26 Aug 2021 12:21:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:44744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243129AbhHZQVS (ORCPT ); Thu, 26 Aug 2021 12:21:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E0E856113D; Thu, 26 Aug 2021 16:20:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629994830; bh=9XXws6BKxRPdG5yXmKJSHmFX2bQQCsKjQzWeVGebNqU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CceUGCxra0KYrnW0L24q3JHAhSV4IEJlBoHD0vapEVLjBdmPSQ4XRWqBMilkJA0/k XdhM3vkJk2BeRYXrp80vZdqTrjklP5KoF4jHxXar+r+zdE0dqRaO/emVUuQureiBnQ dOlv1v4ypj+4xpndNFRgqyvKAU1hV2VlgIyFvsCdWNxkmIixPqOgoxbtrXiZaIMWUv Jqz254C4lca51yB/oRJ7KmyJdW0+N/b22IsNWtHBU+AOQpSb+bRdkYPW3ivFhqVg5C /CBtXddiGgPkoliQT9oQIX755ywPerKdY/DkBjWvf3EXYC8BIRH1DxDthuF00MfRfB B+9MTvc8Be86g== From: Jeff Layton To: ceph-devel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-fscrypt@vger.kernel.org, dhowells@redhat.com, xiubli@redhat.com, lhenriques@suse.de, khiremat@redhat.com, ebiggers@kernel.org Subject: [RFC PATCH v8 15/24] ceph: send altname in MClientRequest Date: Thu, 26 Aug 2021 12:20:05 -0400 Message-Id: <20210826162014.73464-16-jlayton@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210826162014.73464-1-jlayton@kernel.org> References: <20210826162014.73464-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org In the event that we have a filename longer than CEPH_NOHASH_NAME_MAX, we'll need to hash the tail of the filename. The client however will still need to know the full name of the file if it has a key. To support this, the MClientRequest field has grown a new alternate_name field that we populate with the full (binary) crypttext of the filename. This is then transmitted to the clients in readdir or traces as part of the dentry lease. Add support for populating this field when the filenames are very long. Signed-off-by: Jeff Layton --- fs/ceph/mds_client.c | 75 +++++++++++++++++++++++++++++++++++++++++--- fs/ceph/mds_client.h | 3 ++ 2 files changed, 73 insertions(+), 5 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 649341e35b94..6e7cc6ea5502 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -950,6 +950,7 @@ void ceph_mdsc_release_request(struct kref *kref) if (req->r_pagelist) ceph_pagelist_release(req->r_pagelist); kfree(req->r_fscrypt_auth); + kfree(req->r_altname); put_request_session(req); ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation); WARN_ON_ONCE(!list_empty(&req->r_wait)); @@ -2475,6 +2476,63 @@ static inline u64 __get_oldest_tid(struct ceph_mds_client *mdsc) return mdsc->oldest_tid; } +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) +static u8 *get_fscrypt_altname(const struct ceph_mds_request *req, u32 *plen) +{ + struct inode *dir = req->r_parent; + struct dentry *dentry = req->r_dentry; + u8 *cryptbuf = NULL; + u32 len = 0; + int ret = 0; + + /* only encode if we have parent and dentry */ + if (!dir || !dentry) + goto success; + + /* No-op unless this is encrypted */ + if (!IS_ENCRYPTED(dir)) + goto success; + + ret = __fscrypt_prepare_readdir(dir); + if (ret) + return ERR_PTR(ret); + + /* No key? Just ignore it. */ + if (!fscrypt_has_encryption_key(dir)) + goto success; + + if (!fscrypt_fname_encrypted_size(dir, dentry->d_name.len, NAME_MAX, &len)) { + WARN_ON_ONCE(1); + return ERR_PTR(-ENAMETOOLONG); + } + + /* No need to append altname if name is short enough */ + if (len <= CEPH_NOHASH_NAME_MAX) { + len = 0; + goto success; + } + + cryptbuf = kmalloc(len, GFP_KERNEL); + if (!cryptbuf) + return ERR_PTR(-ENOMEM); + + ret = fscrypt_fname_encrypt(dir, &dentry->d_name, cryptbuf, len); + if (ret) { + kfree(cryptbuf); + return ERR_PTR(ret); + } +success: + *plen = len; + return cryptbuf; +} +#else +static u8 *get_fscrypt_altname(const struct ceph_mds_request *req, u32 *plen) +{ + *plen = 0; + return NULL; +} +#endif + /** * ceph_mdsc_build_path - build a path string to a given dentry * @dentry: dentry to which path should be built @@ -2695,14 +2753,15 @@ static void encode_mclientrequest_tail(void **p, const struct ceph_mds_request * ceph_encode_timespec64(&ts, &req->r_stamp); ceph_encode_copy(p, &ts, sizeof(ts)); - /* gid_list */ + /* v4: gid_list */ ceph_encode_32(p, req->r_cred->group_info->ngroups); for (i = 0; i < req->r_cred->group_info->ngroups; i++) ceph_encode_64(p, from_kgid(&init_user_ns, req->r_cred->group_info->gid[i])); - /* v5: altname (TODO: skip for now) */ - ceph_encode_32(p, 0); + /* v5: altname */ + ceph_encode_32(p, req->r_altname_len); + ceph_encode_copy(p, req->r_altname, req->r_altname_len); /* v6: fscrypt_auth and fscrypt_file */ if (req->r_fscrypt_auth) { @@ -2758,7 +2817,13 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, goto out_free1; } - /* head */ + req->r_altname = get_fscrypt_altname(req, &req->r_altname_len); + if (IS_ERR(req->r_altname)) { + msg = ERR_CAST(req->r_altname); + req->r_altname = NULL; + goto out_free2; + } + len = legacy ? sizeof(*head) : sizeof(struct ceph_mds_request_head); /* filepaths */ @@ -2784,7 +2849,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, len += sizeof(u32) + (sizeof(u64) * req->r_cred->group_info->ngroups); /* alternate name */ - len += sizeof(u32); // TODO + len += sizeof(u32) + req->r_altname_len; /* fscrypt_auth */ len += sizeof(u32); // fscrypt_auth diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index 128901a847af..6a2ac489e06e 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -284,6 +284,9 @@ struct ceph_mds_request { struct ceph_fscrypt_auth *r_fscrypt_auth; + u8 *r_altname; /* fscrypt binary crypttext for long filenames */ + u32 r_altname_len; /* length of r_altname */ + int r_fmode; /* file mode, if expecting cap */ const struct cred *r_cred; int r_request_release_offset;