From patchwork Tue Apr 2 15:48:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugen Hristev X-Patchwork-Id: 13614336 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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CC716CD1284 for ; Tue, 2 Apr 2024 15:49:09 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-3.v29.lw.sourceforge.com) by sfs-ml-3.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1rrgNo-0005EO-NV; Tue, 02 Apr 2024 15:49:09 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-3.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rrgNj-0005E7-TW for linux-f2fs-devel@lists.sourceforge.net; Tue, 02 Apr 2024 15:49:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=AKwvK/HS9IUopAhw/EmLrvhjDdrXgu3eEQUUYuZDCwo=; b=nO9lJscGGC5nAu02e7CO6kXBDi UkjNpaEho0lRwWyFuH1CmYlp+5AIUFOmq+iWVXKs50/AD5yrNo9Z1Mi/YtnAjLQ0Mpt891rHr1FSF y56Blh7luvfsOfudqt+0TRWCUQm55lAjEhWf29NwORaMcei91BA6AIHTSCL23Gup3iJc=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=AKwvK/HS9IUopAhw/EmLrvhjDdrXgu3eEQUUYuZDCwo=; b=heidlUpKEzq25OC+9MQaKl/1VJ Npe2KKb3FVr786uIXqEjtP7AeRJo5X+kuQKiu2MyYnUJOR1xLmNoANCkCkTDdGpIoStXaqh4m3uis tTeQ5q3mjbtcB8W+E7ByPXmjb0tyFXhQCSXtvIqSkte4FJpsrePNU0Pnq6iwRGiLFFQA=; Received: from madrid.collaboradmins.com ([46.235.227.194]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1rrgNj-00042s-1r for linux-f2fs-devel@lists.sourceforge.net; Tue, 02 Apr 2024 15:49:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1712072932; bh=upTn9VDPH4ATj696dO2v0HAAxcgXeQncdfgIxpTDi8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=At6Y/fkMPPh7NBpLbP7gT7+bSmI28T5D4dzO8VJBNOUGsTZxktpxHDM98g3MntF5f m5TOqJ7gc2i8eYm3AS6qmhk91epofuEbKzju3tj13nCgvP69GYQSAFakBgK0oKJwhd 8XRIua8emh7dh/OTIlgILTmd8tyaUDWlHino9Ipv4INIlCMUX+dXHCQEVFchljezWu t7WJLydJDV8jGMfUtSuvydhIL98xzzLljwXCE1WtqBioT0286Se3zouSW7W2fAH5sI o3eDK/bzu52uaZeeng7ZbS4gkS3Z6VGhMa8++2N+RYibxf4OHvab8CeXR35T7mL760 vv/fCpUeQa/4Q== Received: from eugen-station.. (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: ehristev) by madrid.collaboradmins.com (Postfix) with ESMTPSA id 30CD037820EF; Tue, 2 Apr 2024 15:48:51 +0000 (UTC) To: tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, jaegeuk@kernel.org, chao@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org Date: Tue, 2 Apr 2024 18:48:36 +0300 Message-Id: <20240402154842.508032-4-eugen.hristev@collabora.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240402154842.508032-1-eugen.hristev@collabora.com> References: <20240402154842.508032-1-eugen.hristev@collabora.com> MIME-Version: 1.0 X-Headers-End: 1rrgNj-00042s-1r Subject: [f2fs-dev] [PATCH v15 3/9] libfs: Introduce case-insensitive string comparison helper X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Eugen Hristev via Linux-f2fs-devel From: Eugen Hristev Reply-To: Eugen Hristev Cc: krisman@suse.de, brauner@kernel.org, jack@suse.cz, linux-kernel@vger.kernel.org, eugen.hristev@collabora.com, viro@zeniv.linux.org.uk, kernel@collabora.com, Gabriel Krisman Bertazi Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: Gabriel Krisman Bertazi generic_ci_match can be used by case-insensitive filesystems to compare strings under lookup with dirents in a case-insensitive way. This function is currently reimplemented by each filesystem supporting casefolding, so this reduces code duplication in filesystem-specific code. Signed-off-by: Gabriel Krisman Bertazi [eugen.hristev@collabora.com: rework to first test the exact match] Signed-off-by: Eugen Hristev --- fs/libfs.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 4 +++ 2 files changed, 81 insertions(+) diff --git a/fs/libfs.c b/fs/libfs.c index c297953db948..711eecc125bd 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1776,6 +1776,83 @@ static const struct dentry_operations generic_ci_dentry_ops = { .d_revalidate = fscrypt_d_revalidate, #endif }; + +/** + * generic_ci_match() - Match a name (case-insensitively) with a dirent. + * This is a filesystem helper for comparison with directory entries. + * generic_ci_d_compare should be used in VFS' ->d_compare instead. + * + * @parent: Inode of the parent of the dirent under comparison + * @name: name under lookup. + * @folded_name: Optional pre-folded name under lookup + * @de_name: Dirent name. + * @de_name_len: dirent name length. + * + * Test whether a case-insensitive directory entry matches the filename + * being searched. If @folded_name is provided, it is used instead of + * recalculating the casefold of @name. + * + * Return: > 0 if the directory entry matches, 0 if it doesn't match, or + * < 0 on error. + */ +int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len) +{ + 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 dirent = QSTR_INIT(de_name, de_name_len); + int res = 0, match = 0; + + if (IS_ENCRYPTED(parent)) { + const struct fscrypt_str encrypted_name = + FSTR_INIT((u8 *) de_name, de_name_len); + + if (WARN_ON_ONCE(!fscrypt_has_encryption_key(parent))) + return -EINVAL; + + decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); + if (!decrypted_name.name) + return -ENOMEM; + res = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, + &decrypted_name); + if (res < 0) + goto out; + dirent.name = decrypted_name.name; + dirent.len = decrypted_name.len; + } + + /* + * Attempt a case-sensitive match first. It is cheaper and + * should cover most lookups, including all the sane + * applications that expect a case-sensitive filesystem. + */ + if (folded_name->name) { + if (dirent.len == folded_name->len && + !memcmp(folded_name->name, dirent.name, dirent.len)) { + match = 1; + goto out; + } + res = utf8_strncasecmp_folded(um, folded_name, &dirent); + } else { + if (dirent.len == name->len && + !memcmp(name->name, dirent.name, dirent.len) && + (!sb_has_strict_encoding(sb) || !utf8_validate(um, name))) { + match = 1; + goto out; + } + res = utf8_strncasecmp(um, name, &dirent); + } + +out: + kfree(decrypted_name.name); + if (res < 0) + return res; + return (match || !res); +} +EXPORT_SYMBOL(generic_ci_match); #endif #ifdef CONFIG_FS_ENCRYPTION diff --git a/include/linux/fs.h b/include/linux/fs.h index ff1338109b54..690b37e1db95 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3281,6 +3281,10 @@ extern int generic_file_fsync(struct file *, loff_t, loff_t, int); extern int generic_check_addressable(unsigned, u64); extern void generic_set_sb_d_ops(struct super_block *sb); +extern int generic_ci_match(const struct inode *parent, + const struct qstr *name, + const struct qstr *folded_name, + const u8 *de_name, u32 de_name_len); static inline bool sb_has_encoding(const struct super_block *sb) {