From patchwork Fri Dec 1 22:11:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 13476457 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=toxicpanda-com.20230601.gappssmtp.com header.i=@toxicpanda-com.20230601.gappssmtp.com header.b="ZGyKVaws" Received: from mail-yw1-x1143.google.com (mail-yw1-x1143.google.com [IPv6:2607:f8b0:4864:20::1143]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 722CF128 for ; Fri, 1 Dec 2023 14:12:15 -0800 (PST) Received: by mail-yw1-x1143.google.com with SMTP id 00721157ae682-5d279bcce64so29649017b3.3 for ; Fri, 01 Dec 2023 14:12:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20230601.gappssmtp.com; s=20230601; t=1701468734; x=1702073534; 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=nGaKZfQ8xEUtcj2BvoUGwcXV31Q0VFKb7VLEms82qyQ=; b=ZGyKVaws3S0GoOwsOzviq3RAPMFOGknLTSLTqBg3I6yBiytMNnautYq3Z6FGyhKx0W aezaykvutmCXEoCso83D7mJMR0Mrqg43s98XjrXttGG0O+0/ArUdg+S+jFhISMjcVOK/ 45E9AnBb3L1SzohKM6zuFxFuXy0WQKaeyjqYDEDDMuYHQ/2MEEjFa5o4PnwcWstFMKkx x3G08Y06VyNzmeo7/gwwIleESZwvuCUW2CJ6DSkXpyljgCJSYCPFhiYBvy4+iRlbNW8P DY9PrPVBP7YxP2j8XuWBbOkwzFOaYfXSV6+W6GVI62X8ZT6AsXrUAGyqAcvx2XXh8lgf RJ5w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1701468734; x=1702073534; 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=nGaKZfQ8xEUtcj2BvoUGwcXV31Q0VFKb7VLEms82qyQ=; b=XjFVEJW+MwXom00rRw+TwOQcdxnxJEkKutK/qvjFIj7zM5hcq+DgJRql82iJAIlIxC Cip/nNo6ZdTyYjJ1VuhY+XkI8N3s4h5Bd9oYM60q6stHQcGZxwPJKV2K2rjHKXwPw4x2 vbp3zrqy7bNb+LQSCX8NlnnovLmETu2fuyMKts4sQcMw8ryrgAL93t+2WdZ/hdmf9gem cirj3qbWVQWIoKTNV/doPfxe9ZImdE0PrbYu3UFqXl7t6zH+Dv05C9TrsHdPNMThrFAG onQgmr3JSgUIF6yVKnfa0mo66XvxK0hMHcNY1/o0SCZNQHEAEMx5cCKuHy1JpTStz04y 4frg== X-Gm-Message-State: AOJu0Yz3029tYaUkwaErY3akIwlYYkpeIzKqIAlPgaYVTnMEGeprX3gb jUEevjQGDyk46i/EJzlOlrDUJQ== X-Google-Smtp-Source: AGHT+IERfmiIIYpmihLJrdT1pqpTfZYUTDg0+VM8i/Q4h5RqR5xJgNcKO+1ZfO9c3q0JsRg6HDBCGg== X-Received: by 2002:a05:690c:3387:b0:5a8:874:bb3a with SMTP id fl7-20020a05690c338700b005a80874bb3amr279105ywb.31.1701468734628; Fri, 01 Dec 2023 14:12:14 -0800 (PST) Received: from localhost (076-182-020-124.res.spectrum.com. [76.182.20.124]) by smtp.gmail.com with ESMTPSA id w72-20020a81494b000000b005d70c0a85casm151282ywa.53.2023.12.01.14.12.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Dec 2023 14:12:14 -0800 (PST) From: Josef Bacik To: linux-btrfs@vger.kernel.org, kernel-team@fb.com, linux-fsdevel@vger.kernel.org Cc: Sweet Tea Dorminy Subject: [PATCH v4 15/46] btrfs: handle nokey names. Date: Fri, 1 Dec 2023 17:11:12 -0500 Message-ID: <5729e533bb7e014a124cc48d793dec30507455b7.1701468306.git.josef@toxicpanda.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 6a4e4f63a660..9103da28af7e 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,