From patchwork Wed May 11 19:31:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriel Krisman Bertazi X-Patchwork-Id: 1629706 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: bilbo.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.a=rsa-sha256 header.s=mail header.b=BGGfiu69; dkim-atps=neutral Received: from gandalf.ozlabs.org (gandalf.ozlabs.org [150.107.74.76]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by bilbo.ozlabs.org (Postfix) with ESMTPS id 4Kz4mQ03WXz9sFk for ; Thu, 12 May 2022 05:32:06 +1000 (AEST) Received: from gandalf.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4Kz4mP6SfHz4xVP for ; Thu, 12 May 2022 05:32:05 +1000 (AEST) Received: by gandalf.ozlabs.org (Postfix) id 4Kz4mP6QQRz4xXh; Thu, 12 May 2022 05:32:05 +1000 (AEST) Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: gandalf.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-ext4-owner@vger.kernel.org; receiver=) Authentication-Results: gandalf.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.a=rsa-sha256 header.s=mail header.b=BGGfiu69; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by gandalf.ozlabs.org (Postfix) with ESMTP id 4Kz4mP6Gclz4xVP for ; Thu, 12 May 2022 05:32:05 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346868AbiEKTcD (ORCPT ); Wed, 11 May 2022 15:32:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37138 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343611AbiEKTcB (ORCPT ); Wed, 11 May 2022 15:32:01 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7212115FDA for ; Wed, 11 May 2022 12:31:59 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id 153E61F42928 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1652297518; bh=O8zfH0g0Xeoi4Ay416v/LfViHrCuc8wWuQ7aplb+RbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BGGfiu69jffYTnTizKAlYk9TfjMnygcZFTtSWqP+htDMYOmxRV6x9cUGTt7ccG1hm BwLwhe3v7WDKQjpN0TzLrVszCppRlCfuRekqHtRp9k1xb2HqHoRGsTj0etGS54tTwt MSDAitgjs5oSwWK07k4t7X3mDgm8zWfHFTqi7ka7Gnftqn/LHHZel5qoxgs1VpCCgC B7kCCuamekyIG3NFF9/OuVpVmZ41bIRpvbmADZSuA9SJlPzEq3BruzNp9waeNfqbY6 fnkm6/HLFMoHivGL5HLb5KKdWiKP40ayc3F1OMITIhtzEo3YAnacqJx1HjxtZGRgjI Ruo9DGi81whVw== From: Gabriel Krisman Bertazi To: tytso@mit.edu, adilger.kernel@dilger.ca, jaegeuk@kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, ebiggers@kernel.org, Gabriel Krisman Bertazi , kernel@collabora.com Subject: [PATCH v4 01/10] ext4: Match the f2fs ci_compare implementation Date: Wed, 11 May 2022 15:31:37 -0400 Message-Id: <20220511193146.27526-2-krisman@collabora.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220511193146.27526-1-krisman@collabora.com> References: <20220511193146.27526-1-krisman@collabora.com> MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE,UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org ext4_ci_compare originally follows utf8_*_strcmp, which means return zero on match. This means that every usage of that in ext4 negates the return. Turn it into a predicate function, let it follow the kernel convention and return true on match, which means it's now the same as its f2fs counterpart and can be extracted into generic code. This change also makes it more obvious that we are ignoring error handling in ext4_match, which can occur since casefolding support (bad utf8 name due to disk corruption on strict mode causes -EINVAL) and casefold+encryption (-ENOMEM). For now, keep the behavior. It is handled by the following patches. While we are there, change the comment to the kernel-doc style. Signed-off-by: Gabriel Krisman Bertazi --- changes since v3: - move variable into code guard (lkp) changes since v1: - rename to match f2fs naming (Eric) --- fs/ext4/namei.c | 66 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 44 insertions(+), 22 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 767b4bfe39c3..59eb3ecfdea7 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1318,22 +1318,29 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) } #if IS_ENABLED(CONFIG_UNICODE) -/* +/** + * ext4_match_ci() - Match (case-insensitive) a name with a dirent. + * @parent: Inode of the parent of the dentry. + * @name: name under lookup. + * @de_name: Dirent name. + * @de_name_len: dirent name length. + * @quick: whether @name is already casefolded. + * * Test whether a case-insensitive directory entry matches the filename - * being searched for. If quick is set, assume the name being looked up - * is already in the casefolded form. + * being searched. If quick is set, the @name being looked up is + * already in the casefolded form. * - * Returns: 0 if the directory entry matches, more than 0 if it - * doesn't match or less than zero on error. + * Return: > 0 if the directory entry matches, 0 if it doesn't match, or + * < 0 on error. */ -static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, - u8 *de_name, size_t de_name_len, bool quick) +static int ext4_match_ci(const struct inode *parent, const struct qstr *name, + u8 *de_name, size_t de_name_len, bool quick) { const struct super_block *sb = parent->i_sb; const struct unicode_map *um = sb->s_encoding; struct fscrypt_str decrypted_name = FSTR_INIT(NULL, de_name_len); struct qstr entry = QSTR_INIT(de_name, de_name_len); - int ret; + int ret, match = false; if (IS_ENCRYPTED(parent)) { const struct fscrypt_str encrypted_name = @@ -1354,20 +1361,22 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, ret = utf8_strncasecmp_folded(um, name, &entry); else ret = utf8_strncasecmp(um, name, &entry); - if (ret < 0) { - /* Handle invalid character sequence as either an error - * or as an opaque byte sequence. + + if (!ret) + match = true; + else if (ret < 0 && !sb_has_strict_encoding(sb)) { + /* + * In non-strict mode, fallback to a byte comparison if + * the names have invalid characters. */ - if (sb_has_strict_encoding(sb)) - ret = -EINVAL; - else if (name->len != entry.len) - ret = 1; - else - ret = !!memcmp(name->name, entry.name, entry.len); + ret = 0; + match = ((name->len == entry.len) && + !memcmp(name->name, entry.name, entry.len)); } + out: kfree(decrypted_name.name); - return ret; + return (ret >= 0) ? match : ret; } int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, @@ -1431,6 +1440,8 @@ static bool ext4_match(struct inode *parent, #if IS_ENABLED(CONFIG_UNICODE) if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) && (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { + int ret; + if (fname->cf_name.name) { struct qstr cf = {.name = fname->cf_name.name, .len = fname->cf_name.len}; @@ -1442,11 +1453,22 @@ static bool ext4_match(struct inode *parent, return false; } } - return !ext4_ci_compare(parent, &cf, de->name, - de->name_len, true); + ret = ext4_match_ci(parent, &cf, de->name, + de->name_len, true); + } else { + ret = ext4_match_ci(parent, fname->usr_fname, + de->name, de->name_len, false); + } + + if (ret < 0) { + /* + * Treat comparison errors as not a match. The + * only case where it happens is on a disk + * corruption or ENOMEM. + */ + return false; } - return !ext4_ci_compare(parent, fname->usr_fname, de->name, - de->name_len, false); + return ret; } #endif