From patchwork Sun Sep 13 08:36:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 11772249 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F103C14F6 for ; Sun, 13 Sep 2020 08:38:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9FED2158C for ; Sun, 13 Sep 2020 08:38:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599986315; bh=SHrYUdtm1g7ntgYtdzixMrvNEz6L5/D07nXI8RMvuM4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SpSRzA6zgLZFjvPHWh6WiSnXENUOqrToKdB0/Q8PJj/zTylAv/M8+MEFMjfcH6W8b i/IaaXY9vwHYno6oGKk70W4rj8MvvEK6s3yz3KYYorKmnuuYbnELAW9hsy/2MykHkB LjjLZcQjeOW/lH2xqlK9jdn6UCiMePY8q6lQDyIw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725994AbgIMIib (ORCPT ); Sun, 13 Sep 2020 04:38:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:60912 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725973AbgIMIiF (ORCPT ); Sun, 13 Sep 2020 04:38:05 -0400 Received: from sol.attlocal.net (172-10-235-113.lightspeed.sntcca.sbcglobal.net [172.10.235.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8F613221E8; Sun, 13 Sep 2020 08:38:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599986280; bh=SHrYUdtm1g7ntgYtdzixMrvNEz6L5/D07nXI8RMvuM4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=veKboLnYaZiOTtz2C8eTq+4ZzLtMFia4/2LmiMxvTMRGrBr7KkSQff6AbozrpZCjI r7KZJPqL7OLkVIJp0K7kUKARQmFdsbBKV25xdjuZcfTY+pIznei/mrRSnKdbJUGBoU ODgwD4kGxAx2Jksu0dMPri89adQ4x8OCkHTNGDEE= From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, ceph-devel@vger.kernel.org, Jeff Layton , Daniel Rosenberg Subject: [PATCH v2 10/11] fscrypt: move fscrypt_prepare_symlink() out-of-line Date: Sun, 13 Sep 2020 01:36:19 -0700 Message-Id: <20200913083620.170627-11-ebiggers@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200913083620.170627-1-ebiggers@kernel.org> References: <20200913083620.170627-1-ebiggers@kernel.org> MIME-Version: 1.0 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org From: Eric Biggers In preparation for moving the logic for "get the encryption policy inherited by new files in this directory" to a single place, make fscrypt_prepare_symlink() a regular function rather than an inline function that wraps __fscrypt_prepare_symlink(). This way, the new function fscrypt_policy_to_inherit() won't need to be exported to filesystems. Signed-off-by: Eric Biggers --- fs/crypto/hooks.c | 39 ++++++++++++++++++++++--- include/linux/fscrypt.h | 63 ++++++++++------------------------------- 2 files changed, 50 insertions(+), 52 deletions(-) diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index 7748db5092409..a399c54947f28 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -166,12 +166,43 @@ int fscrypt_prepare_setflags(struct inode *inode, return 0; } -int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, - unsigned int max_len, - struct fscrypt_str *disk_link) +/** + * fscrypt_prepare_symlink() - prepare to create a possibly-encrypted symlink + * @dir: directory in which the symlink is being created + * @target: plaintext symlink target + * @len: length of @target excluding null terminator + * @max_len: space the filesystem has available to store the symlink target + * @disk_link: (out) the on-disk symlink target being prepared + * + * This function computes the size the symlink target will require on-disk, + * stores it in @disk_link->len, and validates it against @max_len. An + * encrypted symlink may be longer than the original. + * + * Additionally, @disk_link->name is set to @target if the symlink will be + * unencrypted, but left NULL if the symlink will be encrypted. For encrypted + * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the + * on-disk target later. (The reason for the two-step process is that some + * filesystems need to know the size of the symlink target before creating the + * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.) + * + * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long, + * -ENOKEY if the encryption key is missing, or another -errno code if a problem + * occurred while setting up the encryption key. + */ +int fscrypt_prepare_symlink(struct inode *dir, const char *target, + unsigned int len, unsigned int max_len, + struct fscrypt_str *disk_link) { int err; + if (!IS_ENCRYPTED(dir) && !fscrypt_get_dummy_context(dir->i_sb)) { + disk_link->name = (unsigned char *)target; + disk_link->len = len + 1; + if (disk_link->len > max_len) + return -ENAMETOOLONG; + return 0; + } + /* * To calculate the size of the encrypted symlink target we need to know * the amount of NUL padding, which is determined by the flags set in @@ -207,7 +238,7 @@ int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, disk_link->name = NULL; return 0; } -EXPORT_SYMBOL_GPL(__fscrypt_prepare_symlink); +EXPORT_SYMBOL_GPL(fscrypt_prepare_symlink); int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, unsigned int len, struct fscrypt_str *disk_link) diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 81d6ded243288..39e7397a3f103 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -225,9 +225,9 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry, struct fscrypt_name *fname); int fscrypt_prepare_setflags(struct inode *inode, unsigned int oldflags, unsigned int flags); -int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len, - unsigned int max_len, - struct fscrypt_str *disk_link); +int fscrypt_prepare_symlink(struct inode *dir, const char *target, + unsigned int len, unsigned int max_len, + struct fscrypt_str *disk_link); int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, unsigned int len, struct fscrypt_str *disk_link); const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, @@ -520,15 +520,21 @@ static inline int fscrypt_prepare_setflags(struct inode *inode, return 0; } -static inline int __fscrypt_prepare_symlink(struct inode *dir, - unsigned int len, - unsigned int max_len, - struct fscrypt_str *disk_link) +static inline int fscrypt_prepare_symlink(struct inode *dir, + const char *target, + unsigned int len, + unsigned int max_len, + struct fscrypt_str *disk_link) { - return -EOPNOTSUPP; + if (IS_ENCRYPTED(dir)) + return -EOPNOTSUPP; + disk_link->name = (unsigned char *)target; + disk_link->len = len + 1; + if (disk_link->len > max_len) + return -ENAMETOOLONG; + return 0; } - static inline int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, unsigned int len, @@ -793,45 +799,6 @@ static inline int fscrypt_prepare_setattr(struct dentry *dentry, return 0; } -/** - * fscrypt_prepare_symlink() - prepare to create a possibly-encrypted symlink - * @dir: directory in which the symlink is being created - * @target: plaintext symlink target - * @len: length of @target excluding null terminator - * @max_len: space the filesystem has available to store the symlink target - * @disk_link: (out) the on-disk symlink target being prepared - * - * This function computes the size the symlink target will require on-disk, - * stores it in @disk_link->len, and validates it against @max_len. An - * encrypted symlink may be longer than the original. - * - * Additionally, @disk_link->name is set to @target if the symlink will be - * unencrypted, but left NULL if the symlink will be encrypted. For encrypted - * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the - * on-disk target later. (The reason for the two-step process is that some - * filesystems need to know the size of the symlink target before creating the - * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.) - * - * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long, - * -ENOKEY if the encryption key is missing, or another -errno code if a problem - * occurred while setting up the encryption key. - */ -static inline int fscrypt_prepare_symlink(struct inode *dir, - const char *target, - unsigned int len, - unsigned int max_len, - struct fscrypt_str *disk_link) -{ - if (IS_ENCRYPTED(dir) || fscrypt_get_dummy_context(dir->i_sb) != NULL) - return __fscrypt_prepare_symlink(dir, len, max_len, disk_link); - - disk_link->name = (unsigned char *)target; - disk_link->len = len + 1; - if (disk_link->len > max_len) - return -ENAMETOOLONG; - return 0; -} - /** * fscrypt_encrypt_symlink() - encrypt the symlink target if needed * @inode: symlink inode