From patchwork Thu Jun 6 07:33:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugen Hristev X-Patchwork-Id: 13687941 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 84F45C27C52 for ; Thu, 6 Jun 2024 07:34:55 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-1.v29.lw.sourceforge.com) by sfs-ml-1.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1sF7eA-0003Wx-0Q; Thu, 06 Jun 2024 07:34:55 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-1.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1sF7e5-0003Wm-7d for linux-f2fs-devel@lists.sourceforge.net; Thu, 06 Jun 2024 07:34:50 +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=nGCRfoowmW936zp+wg6FWdWM7gCYhe027V7cxi9zvXs=; b=UpCLmjFaLaJ9X/YtVehfmCOlPj PehvQSaN4hls3CA/gtw6937hMQIUasP42qkXDM+QYgyJYfZkDg6+gK2CAyMbJtmc+tGn+9odIPIgv m94ZyBPlKl5Tf2Wwb3eizEATwpzAvn6Wm3rs3cmsaDvfQU6yPh4cmCfUJgO/gSxRBAUo=; 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=nGCRfoowmW936zp+wg6FWdWM7gCYhe027V7cxi9zvXs=; b=nDsSYZGF8v1SMm17Cxr+nWygdp lfhNEXD7kimLJ2PDwqKDaLGltHiDtpgYmm7yEOxV5xZy6BqnE6K4aEKnr+K8bI3DYMa7G/zIcSeAU khtRYfeVSwuXkQKLZ9phHUPWr6dLly0CNf0jnsxKNSlxGIhWVqR/EQR75AqvMiTzQuLg=; 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 1sF7e6-0001xb-8P for linux-f2fs-devel@lists.sourceforge.net; Thu, 06 Jun 2024 07:34:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1717659278; bh=k2lM/43/rKq0SBXPEuuWsOvKQDRgGSdsJNLUcoGSQAk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bwk759Hgvf6pJ0JDfaJ160yU1e/Ss5JUWAja70s0ShWdkVC9PUbBxMCINfP4Myiiq rm399mv27ekOXn+qCPtmZku1SCJLW8NrrxCGi5eJ4DobkE9ekAIhEvmPEiiv2GcwCU KhjHmWF8DLNhoQjf3wb54xqNLVKfLavwrl9klOeCyBTak9md39qNrdfD+tM3nHJfEV fUm3CJzsjCzeocrXduuqS/6Y519NkO2c6/JGOiVMYTHMlTlw5GT0L6j/VKz07Z9uV3 9Cwq6HxfDJNrBET59yinZnAUlf+16mQpvjKVYWTpnG8zfzMbBt6nC0HWaxJPsiAuYF F6HjLy7IEyw6g== 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 3CE2E37821D7; Thu, 6 Jun 2024 07:34:37 +0000 (UTC) To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, jaegeuk@kernel.org, adilger.kernel@dilger.ca, tytso@mit.edu Date: Thu, 6 Jun 2024 10:33:49 +0300 Message-Id: <20240606073353.47130-4-eugen.hristev@collabora.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240606073353.47130-1-eugen.hristev@collabora.com> References: <20240606073353.47130-1-eugen.hristev@collabora.com> MIME-Version: 1.0 X-Headers-End: 1sF7e6-0001xb-8P Subject: [f2fs-dev] [PATCH v18 3/7] 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, ebiggers@google.com, Eugen Hristev , 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, cleanup and add error message] Signed-off-by: Eugen Hristev --- fs/libfs.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/fs.h | 4 +++ 2 files changed, 78 insertions(+) diff --git a/fs/libfs.c b/fs/libfs.c index b635ee5adbcc..8aa34870449f 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1854,6 +1854,80 @@ 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; + + 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) { + kfree(decrypted_name.name); + return res; + } + 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 (dirent.len == name->len && + !memcmp(name->name, dirent.name, dirent.len)) + goto out; + + if (folded_name->name) + res = utf8_strncasecmp_folded(um, folded_name, &dirent); + else + res = utf8_strncasecmp(um, name, &dirent); + +out: + kfree(decrypted_name.name); + if (res < 0 && sb_has_strict_encoding(sb)) { + pr_err_ratelimited("Directory contains filename that is invalid UTF-8"); + return 0; + } + return !res; +} +EXPORT_SYMBOL(generic_ci_match); #endif #ifdef CONFIG_FS_ENCRYPTION diff --git a/include/linux/fs.h b/include/linux/fs.h index 639885621608..f8ca264a0edc 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3367,6 +3367,10 @@ 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) {