From patchwork Tue Jan 11 19:15:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeffrey Layton X-Patchwork-Id: 12710423 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D0A6C4167B for ; Tue, 11 Jan 2022 19:16:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346513AbiAKTQ6 (ORCPT ); Tue, 11 Jan 2022 14:16:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350593AbiAKTQe (ORCPT ); Tue, 11 Jan 2022 14:16:34 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 868DAC0611FD; Tue, 11 Jan 2022 11:16:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2466D61787; Tue, 11 Jan 2022 19:16:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23BF7C36AF2; Tue, 11 Jan 2022 19:16:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641928581; bh=zzp8Rf8VryXdSEJl4aLI+jaPmNb7jYx33G7Abyik2jQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u0OhK1V62nLHnPxVmQu9JRH51YMiDAxp4ps+PSLTenfT5t3H7q8ibMPEekDoeszPa WZByPX8BkDTLyMnkUwIebAMA5MPvlYHAtx7PYn2nOy+AJzQKbFxfln9DIxMR3a6fPr 8F1wLujAviErx8yaKL1NE2i715BbF+PPsTcoII5j0SvZ90R/vd4eGPdDHOYtSeOSPp jiOs0ARkaJ9JBwoXA1dYjIAk4NvOPffQla58bbTPBKEZxS6+lYSJqaMbVgCnBFzYeC HR9cXj4urJ7ys+czbWmIFX2bm4vRTZ3oMzqpa6hO2bsmkdQ/EQNcsqxJLeJb55xmdD l3NYrQv/DGuig== From: Jeff Layton To: ceph-devel@vger.kernel.org, linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, idryomov@gmail.com Subject: [RFC PATCH v10 15/48] ceph: send altname in MClientRequest Date: Tue, 11 Jan 2022 14:15:35 -0500 Message-Id: <20220111191608.88762-16-jlayton@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220111191608.88762-1-jlayton@kernel.org> References: <20220111191608.88762-1-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 9552a2eb3e10..8d84995481f2 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -943,6 +943,7 @@ 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)); @@ -2356,6 +2357,63 @@ 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 @@ -2576,14 +2634,15 @@ 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) { @@ -2639,7 +2698,13 @@ 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 */ @@ -2665,7 +2730,7 @@ 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;