From patchwork Tue Sep 26 18:01:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 13399486 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 0722CE7E62B for ; Tue, 26 Sep 2023 18:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235470AbjIZSDj (ORCPT ); Tue, 26 Sep 2023 14:03:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235455AbjIZSDi (ORCPT ); Tue, 26 Sep 2023 14:03:38 -0400 Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EE8B120 for ; Tue, 26 Sep 2023 11:03:30 -0700 (PDT) Received: by mail-qk1-x72c.google.com with SMTP id af79cd13be357-77409065623so557827585a.0 for ; Tue, 26 Sep 2023 11:03:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20230601.gappssmtp.com; s=20230601; t=1695751409; x=1696356209; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=TmXdaeI9xeYx0BBBrgcCT3hL6DULvaaya1NKFl2gOGI=; b=csRuL6/ie428vpSapLOzr+l0UYLQlXakH3ZxA9deziGbpNwS7DWSrEHjwnPEiHHQ2y sjvg0SP5f5i071bT9Yc7T4LEFUOEua77LlneovAhpKujYFQQt47jIwEOFS0BKFbLaPaG m/heSHxmLQD86b0YNtv/TXN3+zl95JdziebJmtIEhbC+u3ekzq9rKbYTvx406f01vUuj gq3X0pjl+5jYLhnDOAx2Vj89EvpRMGurtAtl98vvsVMoyW6RUU+oha9+DqtNNhvNO6OE 1fRvC0YQSyxZcNzhbmPDE8ziR1plRQvtVrn3HEjO+MJGIJZ8SacohWpkjjlGizC4tfmN ATnw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695751409; x=1696356209; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=TmXdaeI9xeYx0BBBrgcCT3hL6DULvaaya1NKFl2gOGI=; b=A9Kb/mZDu49076idsIaQU3TcomyH+01EYa0uj0ke2tSW9FnE/M1/JvaU3daATe8mMl PvuQELi93hOgniED/k3lSl3RIv8lVvoz3OTeJUiHwhaWwtevfAL7CSOIVIPvmpIXQ0E5 WeeFj29Lpeu4HbN7bxS/7zyt8AYoF+SPYx/Rlpqaq1+RlIs6IWh0CgwU2ACtIba2LpZp kOiX1Lowa6GADDqE6nz8/NFPRZQjtpbjUvLB0EUnGRx0mKy0VkAj1ZfoNQCejOfr0Apr wkS9Tv7zNES9IkhSI1bhKczp+wrCsdec6v8ZNCD6AXLxTKpTj6F7y+sguCKcd5uoetk0 3eQw== X-Gm-Message-State: AOJu0YzsssROUYZ8813xZviITy1HnkxJy99RMJWn87Q6XaPj7T9IHzf1 EGxxSaiq+DivPeUuf0mGnnfiJoPFUFPXJOB8hvU5tA== X-Google-Smtp-Source: AGHT+IH1VMMScr8itd/IGkf3v0WELyvvY4Zwh7Pl69hBp/W0isHpKhJUjVz+ZrvF1jBH1iF3em4LZw== X-Received: by 2002:a05:620a:a1e:b0:774:20bb:2473 with SMTP id i30-20020a05620a0a1e00b0077420bb2473mr8947961qka.25.1695751409393; Tue, 26 Sep 2023 11:03:29 -0700 (PDT) Received: from localhost (cpe-76-182-20-124.nc.res.rr.com. [76.182.20.124]) by smtp.gmail.com with ESMTPSA id cx18-20020a05620a51d200b007742c2ad7dfsm2497732qkb.73.2023.09.26.11.03.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Sep 2023 11:03:29 -0700 (PDT) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com, ebiggers@kernel.org, linux-fscrypt@vger.kernel.org, ngompa13@gmail.com Cc: Sweet Tea Dorminy Subject: [PATCH 14/35] btrfs: handle nokey names. Date: Tue, 26 Sep 2023 14:01:40 -0400 Message-ID: <705b288d259f0fde3949334250378c620ab84953.1695750478.git.josef@toxicpanda.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Sweet Tea Dorminy For encrypted or unencrypted names, we calculate the offset for the dir item by hashing the name for the dir item. However, this doesn't work for a long nokey name, where we do not have the complete ciphertext. Instead, fscrypt stores the filesystem-provided hash in the nokey name, and we can extract it from the fscrypt_name structure in such a case. Additionally, for nokey names, if we find the nokey name on disk we can update the fscrypt_name with the disk name, so add that to searching for diritems. Signed-off-by: Sweet Tea Dorminy Signed-off-by: Josef Bacik --- fs/btrfs/dir-item.c | 37 +++++++++++++++++++++++++++++++++++-- fs/btrfs/fscrypt.c | 27 +++++++++++++++++++++++++++ fs/btrfs/fscrypt.h | 11 +++++++++++ 3 files changed, 73 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c index a64cfddff7f0..897fb5477369 100644 --- a/fs/btrfs/dir-item.c +++ b/fs/btrfs/dir-item.c @@ -231,6 +231,28 @@ struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans, return di; } +/* + * If appropriate, populate the disk name for a fscrypt_name looked up without + * a key. + * + * @path: The path to the extent buffer in which the name was found. + * @di: The dir item corresponding. + * @fname: The fscrypt_name to perhaps populate. + * + * Returns: 0 if the name is already populated or the dir item doesn't exist + * or the name was successfully populated, else an error code. + */ +static int ensure_disk_name_from_dir_item(struct btrfs_path *path, + struct btrfs_dir_item *di, + struct fscrypt_name *name) +{ + if (name->disk_name.name || !di) + return 0; + + return btrfs_fscrypt_get_disk_name(path->nodes[0], di, + &name->disk_name); +} + /* * Lookup for a directory item by fscrypt_name. * @@ -257,8 +279,12 @@ struct btrfs_dir_item *btrfs_lookup_dir_item_fname(struct btrfs_trans_handle *tr key.objectid = dir; key.type = BTRFS_DIR_ITEM_KEY; - key.offset = btrfs_name_hash(name->disk_name.name, name->disk_name.len); - /* XXX get the right hash for no-key names */ + + if (!name->disk_name.name) + key.offset = name->hash | ((u64)name->minor_hash << 32); + else + key.offset = btrfs_name_hash(name->disk_name.name, + name->disk_name.len); ret = btrfs_search_slot(trans, root, &key, path, mod, -mod); if (ret == 0) @@ -266,6 +292,8 @@ struct btrfs_dir_item *btrfs_lookup_dir_item_fname(struct btrfs_trans_handle *tr if (ret == -ENOENT || (di && IS_ERR(di) && PTR_ERR(di) == -ENOENT)) return NULL; + if (ret == 0) + ret = ensure_disk_name_from_dir_item(path, di, name); if (ret < 0) di = ERR_PTR(ret); @@ -382,7 +410,12 @@ btrfs_search_dir_index_item(struct btrfs_root *root, struct btrfs_path *path, btrfs_for_each_slot(root, &key, &key, path, ret) { if (key.objectid != dirid || key.type != BTRFS_DIR_INDEX_KEY) break; + di = btrfs_match_dir_item_fname(root->fs_info, path, name); + if (di) + ret = ensure_disk_name_from_dir_item(path, di, name); + if (ret) + break; if (di) return di; } diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c index 588966f0414f..254e48005aec 100644 --- a/fs/btrfs/fscrypt.c +++ b/fs/btrfs/fscrypt.c @@ -14,6 +14,33 @@ #include "transaction.h" #include "xattr.h" +/* + * From a given location in a leaf, read a name into a qstr (usually a + * fscrypt_name's disk_name), allocating the required buffer. Used for + * nokey names. + */ +int btrfs_fscrypt_get_disk_name(struct extent_buffer *leaf, + struct btrfs_dir_item *dir_item, + struct fscrypt_str *name) +{ + unsigned long de_name_len = btrfs_dir_name_len(leaf, dir_item); + unsigned long de_name = (unsigned long)(dir_item + 1); + /* + * For no-key names, we use this opportunity to find the disk + * name, so future searches don't need to deal with nokey names + * and we know what the encrypted size is. + */ + name->name = kmalloc(de_name_len, GFP_NOFS); + + if (!name->name) + return -ENOMEM; + + read_extent_buffer(leaf, name->name, de_name, de_name_len); + + name->len = de_name_len; + return 0; +} + /* * This function is extremely similar to fscrypt_match_name() but uses an * extent_buffer. diff --git a/fs/btrfs/fscrypt.h b/fs/btrfs/fscrypt.h index 1647bbbcd609..c08fd52c99b4 100644 --- a/fs/btrfs/fscrypt.h +++ b/fs/btrfs/fscrypt.h @@ -9,11 +9,22 @@ #include "fs.h" #ifdef CONFIG_FS_ENCRYPTION +int btrfs_fscrypt_get_disk_name(struct extent_buffer *leaf, + struct btrfs_dir_item *di, + struct fscrypt_str *qstr); + bool btrfs_fscrypt_match_name(struct fscrypt_name *fname, struct extent_buffer *leaf, unsigned long de_name, u32 de_name_len); #else +static inline int btrfs_fscrypt_get_disk_name(struct extent_buffer *leaf, + struct btrfs_dir_item *di, + struct fscrypt_str *qstr) +{ + return 0; +} + static inline bool btrfs_fscrypt_match_name(struct fscrypt_name *fname, struct extent_buffer *leaf, unsigned long de_name,