From mboxrd@z Thu Jan 1 00:00:00 1970 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 DF914C43217 for ; Tue, 29 Mar 2022 16:11:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239367AbiC2QM7 (ORCPT ); Tue, 29 Mar 2022 12:12:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58436 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239424AbiC2QMy (ORCPT ); Tue, 29 Mar 2022 12:12:54 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [46.235.227.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68BF6179B2B for ; Tue, 29 Mar 2022 09:11:10 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: krisman) with ESMTPSA id B20161F43BEF DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1648570269; bh=+nF0Nh8Kpe7S8dE2sih8gQscORN4DBqfR+PhxmMpRsI=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=QMToq4AE7tSpPM6UOpE3M0cSCbO4W0lyL1+zo6ew4ktnuF1BIRexOwAq2BTuTG8Ky vckBLZpRtDklEcwydska0Ckw5/zgGGfjR9UhJQxpEoPx12QVVBHj8JeofvCEBQ4a/c LfVF864iwJYKtS1Bd5brJz4ZUqGm41GDZauryrPU2lEs/BRXGK/RPEdqbG4sYAvrJX pjSxnNRA+zQ0pfDYTAMP0jgHstiW/FNBdW15bo2+OjfMCD3186lhZvDxino1yH9bPq /4v0dCp/to48PlxUPHhVbbe6lHio+o4/E7voCsluRGO0doOaeDug8DhYg+Hl5N23ea OV8WOYTshvYVw== From: Gabriel Krisman Bertazi To: Eric Biggers Cc: tytso@mit.edu, jaegeuk@kernel.org, linux-ext4@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCH 3/5] ext4: Implement ci comparison using fscrypt_name Organization: Collabora References: <20220322030004.148560-1-krisman@collabora.com> <20220322030004.148560-4-krisman@collabora.com> Date: Tue, 29 Mar 2022 12:11:04 -0400 In-Reply-To: (Eric Biggers's message of "Mon, 28 Mar 2022 20:08:23 -0700") Message-ID: <87k0ccrb6v.fsf@collabora.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Eric Biggers writes: > On Mon, Mar 21, 2022 at 11:00:02PM -0400, Gabriel Krisman Bertazi wrote: >> By using fscrypt_name here, we can hide most of the caching casefold >> logic from ext4. The condition in ext4_match is now quite redundant, >> but this is addressed in the next patch. >> >> Signed-off-by: Gabriel Krisman Bertazi >> --- >> fs/ext4/namei.c | 26 ++++++++++++-------------- >> include/linux/fscrypt.h | 4 ++++ >> 2 files changed, 16 insertions(+), 14 deletions(-) >> >> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c >> index 8976e5a28c73..71b4b05fae89 100644 >> --- a/fs/ext4/namei.c >> +++ b/fs/ext4/namei.c >> @@ -1321,10 +1321,9 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) >> /** >> * ext4_ci_compare() - Match (case-insensitive) a name with a dirent. >> * @parent: Inode of the parent of the dentry. >> - * @name: name under lookup. >> + * @fname: 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. If quick is set, the @name being looked up is >> @@ -1333,8 +1332,9 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) >> * 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_ci_compare(const struct inode *parent, >> + const struct fscrypt_name *fname, >> + u8 *de_name, size_t de_name_len) >> { >> const struct super_block *sb = parent->i_sb; >> const struct unicode_map *um = sb->s_encoding; >> @@ -1357,10 +1357,10 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, >> entry.len = decrypted_name.len; >> } >> >> - if (quick) >> - ret = utf8_strncasecmp_folded(um, name, &entry); >> + if (fname->cf_name.name) >> + ret = utf8_strncasecmp_folded(um, &fname->cf_name, &entry); >> else >> - ret = utf8_strncasecmp(um, name, &entry); >> + ret = utf8_strncasecmp(um, fname->usr_fname, &entry); >> >> if (!ret) >> match = true; >> @@ -1370,8 +1370,8 @@ static int ext4_ci_compare(const struct inode *parent, const struct qstr *name, >> * the names have invalid characters. >> */ >> ret = 0; >> - match = ((name->len == entry.len) && >> - !memcmp(name->name, entry.name, entry.len)); >> + match = ((fname->usr_fname->len == entry.len) && >> + !memcmp(fname->usr_fname->name, entry.name, entry.len)); >> } >> >> out: >> @@ -1440,6 +1440,8 @@ static bool ext4_match(struct inode *parent, >> #endif >> >> #if IS_ENABLED(CONFIG_UNICODE) >> + f.cf_name = fname->cf_name; >> + >> if (parent->i_sb->s_encoding && IS_CASEFOLDED(parent) && >> (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { >> if (fname->cf_name.name) { >> @@ -1451,13 +1453,9 @@ static bool ext4_match(struct inode *parent, >> return false; >> } >> } >> - ret = ext4_ci_compare(parent, &fname->cf_name, de->name, >> - de->name_len, true); >> - } else { >> - ret = ext4_ci_compare(parent, fname->usr_fname, >> - de->name, de->name_len, false); >> } >> >> + ret = ext4_ci_compare(parent, &f, de->name, de->name_len); >> if (ret < 0) { >> /* >> * Treat comparison errors as not a match. The >> diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h >> index 91ea9477e9bd..5dc4b3c805e4 100644 >> --- a/include/linux/fscrypt.h >> +++ b/include/linux/fscrypt.h >> @@ -36,6 +36,10 @@ struct fscrypt_name { >> u32 minor_hash; >> struct fscrypt_str crypto_buf; >> bool is_nokey_name; >> + >> +#ifdef CONFIG_UNICODE >> + struct qstr cf_name; >> +#endif >> }; >> > > This seems like the wrong approach. struct fscrypt_name shouldn't have fields > that aren't used by the fs/crypto/ layer. > > Did you check what f2fs does? It has a struct f2fs_filename to represent > everything f2fs needs to know about a filename, and it only uses > struct fscrypt_name when communicating with the fs/crypto/ layer. > > struct ext4_filename already exists. Couldn't you use that here? Hi Eric, The reason I'm not using struct ext4_filename here is because I'm trying to make this generic, so this function can be shared across filesystems implementing casefold. Since the fscrypt_name abstraction is used for case-sensitive comparison, I was trying to reuse that type for case-insensitive as well. It seemed unnecessary to define a generic casefold_name type just for passing the cf_name and disk_name to this function, considering that fscrypt_name is already initialized by ext4_match. -- Gabriel Krisman Bertazi