From patchwork Fri Apr 5 12:13:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugen Hristev X-Patchwork-Id: 13618992 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 77186CD1299 for ; Fri, 5 Apr 2024 12:14:21 +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 1rsiSa-0003yU-O0; Fri, 05 Apr 2024 12:14:21 +0000 Received: from [172.30.20.202] (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 1rsiSX-0003yG-RC for linux-f2fs-devel@lists.sourceforge.net; Fri, 05 Apr 2024 12:14:18 +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=Vc7fqOC7SkJfepNzo44OucZ7wbHiHZxidGx82bq3P88=; b=DmLSVjrSXgrq+l0sOEf+oTz5m8 TvkKUeFKIsvMgXEV0C6IOR+rx5u5WIScrdFDipCY+ljEYCP7S98BVzFbwqCiLNGN79glaKB7LQa2S e70X8KHm5bU2nLWERoJVCNn7USXIU3irkosx3gxt4vE5hQ8AhHI2lTgLzD0rxYsnBWzk=; 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=Vc7fqOC7SkJfepNzo44OucZ7wbHiHZxidGx82bq3P88=; b=XDo1aSIcPf4I+1gacAXP02nO/g 3Htxx794Y6hOaU68mSgie7vIe3XfMUDyvA2udJ5edjBhmU5TXNgf9C7ZhJoYjgb0iGQxZq3DMCD62 8HNiS/0F6DutW5yNTBMrJ5mV8F3cXxC76j9np/3u4cgOnt9y0GK4iOkpFzvC9+EP/DJk=; 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 1rsiSW-0004Xh-Ji for linux-f2fs-devel@lists.sourceforge.net; Fri, 05 Apr 2024 12:14:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1712319245; bh=swtZ6BKu+FGmiqRjglGL90hSAB3JlB+upSuAXL/TJpA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LeamS+SotQsJpfKSCnUeuxt8Br9jyLEZm/Oc4Fdf61ABZ3mc4VL304RbXIFEtCkeR JYxBeVgFsCJzLqMa5IqSF2ZK0MzIDm8C729n0aqoLmXu0rbmWIAkpTvoLx1CJBzbfx rda9j9UBrt5qJ+5WB3xuDfM+rTKK+mUxL/3B8JMaobZtTB/967CD9SuuWhzhqRQc/2 19AYHVTMDxFXo36IaWAuVEw4jiZohKW3c6dB/58mcM6ubmX1zy4HYwGefqWHR3ilaI BV0Qq5AyYQl/GsVKY0R5JcCKJCqrztVWK+nV0uYTvuH9WExXQSqoHb9ao14NzWBPDd Gkanvxpl+ny5Q== 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 CD38E3782133; Fri, 5 Apr 2024 12:14:04 +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: Fri, 5 Apr 2024 15:13:27 +0300 Message-Id: <20240405121332.689228-5-eugen.hristev@collabora.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240405121332.689228-1-eugen.hristev@collabora.com> References: <20240405121332.689228-1-eugen.hristev@collabora.com> MIME-Version: 1.0 X-Headers-End: 1rsiSW-0004Xh-Ji Subject: [f2fs-dev] [PATCH v16 4/9] ext4: Reuse generic_ci_match for ci comparisons 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, ebiggers@kernel.org, viro@zeniv.linux.org.uk, kernel@collabora.com, Gabriel Krisman Bertazi Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net From: Gabriel Krisman Bertazi Instead of reimplementing ext4_match_ci, use the new libfs helper. It also adds a comment explaining why fname->cf_name.name must be checked prior to the encryption hash optimization, because that tripped me before. Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Eugen Hristev Reviewed-by: Eric Biggers --- fs/ext4/namei.c | 91 +++++++++++++++---------------------------------- 1 file changed, 27 insertions(+), 64 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index b96983a4c185..2d0ee232fbe7 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1390,58 +1390,6 @@ static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block) } #if IS_ENABLED(CONFIG_UNICODE) -/* - * 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. - * - * Returns: 0 if the directory entry matches, more than 0 if it - * doesn't match or less than zero 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) -{ - 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; - - if (IS_ENCRYPTED(parent)) { - const struct fscrypt_str encrypted_name = - FSTR_INIT(de_name, de_name_len); - - decrypted_name.name = kmalloc(de_name_len, GFP_KERNEL); - if (!decrypted_name.name) - return -ENOMEM; - ret = fscrypt_fname_disk_to_usr(parent, 0, 0, &encrypted_name, - &decrypted_name); - if (ret < 0) - goto out; - entry.name = decrypted_name.name; - entry.len = decrypted_name.len; - } - - if (quick) - 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 (sb_has_strict_encoding(sb)) - ret = -EINVAL; - else if (name->len != entry.len) - ret = 1; - else - ret = !!memcmp(name->name, entry.name, entry.len); - } -out: - kfree(decrypted_name.name); - return ret; -} - int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname, struct ext4_filename *name) { @@ -1503,20 +1451,35 @@ static bool ext4_match(struct inode *parent, #if IS_ENABLED(CONFIG_UNICODE) if (IS_CASEFOLDED(parent) && (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) { - if (fname->cf_name.name) { - if (IS_ENCRYPTED(parent)) { - if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || - fname->hinfo.minor_hash != - EXT4_DIRENT_MINOR_HASH(de)) { + int ret; - return false; - } - } - return !ext4_ci_compare(parent, &fname->cf_name, - de->name, de->name_len, true); + /* + * Just checking IS_ENCRYPTED(parent) below is not + * sufficient to decide whether one can use the hash for + * skipping the string comparison, because the key might + * have been added right after + * ext4_fname_setup_ci_filename(). In this case, a hash + * mismatch will be a false negative. Therefore, make + * sure cf_name was properly initialized before + * considering the calculated hash. + */ + if (IS_ENCRYPTED(parent) && fname->cf_name.name && + (fname->hinfo.hash != EXT4_DIRENT_HASH(de) || + fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de))) + return false; + + ret = generic_ci_match(parent, fname->usr_fname, + &fname->cf_name, de->name, + de->name_len); + 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