From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3A4741C6A; Wed, 13 Mar 2024 23:17:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710371825; cv=none; b=XMNZMLFV9xIEKE/zu2VH0bN/KV3LHcSrg31E8dEZwO2oc+ODFsKM9jLPFXP7Vx5bnK8o8bwAnqJxaygz+bzLpgkV/BBGZIyFkA1wfyoGA/AEUf+/810O3yNtqT0wNmvO642pkyg+hrqj4+VEhmgW8/I/UGvIgHgWIwsFMzHQzuw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710371825; c=relaxed/simple; bh=8lzW/AQHC+tREFa+aWy43EFhJt/UIZCWdjroRaubi+I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=P2Ze8fyoAq/ek7gTAxuPBaFPQmtMN5Sjeq4ZCRWDO+viSkSqbNkzsdNjzc4aVV8ijaC554Uuiw0Q7Ljsuideoll48+T2a85lBF7kOQnS8U0Mh/ntMmKyYkbpu5nRgr+2F3w/sKOW5qb0Gc0V0/+85Ltr8RzM4Eb3i0wsE304SG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=GqWrSyHq; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=i9lzNmZ8; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=GqWrSyHq; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=i9lzNmZ8; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="GqWrSyHq"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="i9lzNmZ8"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="GqWrSyHq"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="i9lzNmZ8" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (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) by smtp-out1.suse.de (Postfix) with ESMTPS id BAF6821C8B; Wed, 13 Mar 2024 23:17:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1710371821; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j7RbUqbuA7M29O8XyGy5jta6BO+8xzgDHtTQ2mM79V8=; b=GqWrSyHqcJY1yQWvgbV+eS7TGk3R1eowFEWk8qH++wqW1XOoog8N1CRLbQ/5syORsdTWs2 E3Sw0PmY8ySJuHqw2q8llZjFUnrCE1+vOZZHrnVxpz8ejlZlK1C5janPKENqbus7Frm9lT HFEJEruoNqLwoAeqYWOs99xStMyqLcQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1710371821; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j7RbUqbuA7M29O8XyGy5jta6BO+8xzgDHtTQ2mM79V8=; b=i9lzNmZ8JB8vdNSz3LV4JUZq2HVGHzkH69nJEdM9rL25pEZfNX8gmbKBMpZ68Bw6enKDBi 5e0qyiWiCOXTJoBg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1710371821; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j7RbUqbuA7M29O8XyGy5jta6BO+8xzgDHtTQ2mM79V8=; b=GqWrSyHqcJY1yQWvgbV+eS7TGk3R1eowFEWk8qH++wqW1XOoog8N1CRLbQ/5syORsdTWs2 E3Sw0PmY8ySJuHqw2q8llZjFUnrCE1+vOZZHrnVxpz8ejlZlK1C5janPKENqbus7Frm9lT HFEJEruoNqLwoAeqYWOs99xStMyqLcQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1710371821; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=j7RbUqbuA7M29O8XyGy5jta6BO+8xzgDHtTQ2mM79V8=; b=i9lzNmZ8JB8vdNSz3LV4JUZq2HVGHzkH69nJEdM9rL25pEZfNX8gmbKBMpZ68Bw6enKDBi 5e0qyiWiCOXTJoBg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (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) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 80CC213977; Wed, 13 Mar 2024 23:17:01 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 3BhxGe0z8mU0BQAAD6G6ig (envelope-from ); Wed, 13 Mar 2024 23:17:01 +0000 From: Gabriel Krisman Bertazi To: Eugen Hristev Cc: 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, linux-kernel@vger.kernel.org, kernel@collabora.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, Gabriel Krisman Bertazi Subject: Re: [PATCH v13 3/9] libfs: Introduce case-insensitive string comparison helper In-Reply-To: <20240305101608.67943-4-eugen.hristev@collabora.com> (Eugen Hristev's message of "Tue, 5 Mar 2024 12:16:02 +0200") Organization: SUSE References: <20240305101608.67943-1-eugen.hristev@collabora.com> <20240305101608.67943-4-eugen.hristev@collabora.com> Date: Wed, 13 Mar 2024 19:16:56 -0400 Message-ID: <87il1pk9hz.fsf@mailhost.krisman.be> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Authentication-Results: smtp-out1.suse.de; none X-Spam-Level: X-Spam-Score: -4.30 X-Spamd-Result: default: False [-4.30 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[text/plain]; HAS_ORG_HEADER(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; RCPT_COUNT_TWELVE(0.00)[14]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] X-Spam-Flag: NO Eugen Hristev writes: > 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 | 81 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/fs.h | 4 +++ > 2 files changed, 85 insertions(+) > > diff --git a/fs/libfs.c b/fs/libfs.c > index c297953db948..c107c24f33b9 100644 > --- a/fs/libfs.c > +++ b/fs/libfs.c > @@ -1776,6 +1776,87 @@ 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, 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 (match) /* matched by direct comparison */ > + return 1; > + else if (!res) /* matched by utf8 comparison */ > + return 1; > + else if (res < 0) /* error on utf8 comparison */ > + return res; > + return 0; /* no match */ > +} I think I've made this comment before, but I'd prefer this to be written in a much simpler way if (res < 0) return res; return (match || !res); Other than that, this looks good to me. -- Gabriel Krisman Bertazi