From patchwork Fri Jan 28 23:39:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12729263 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68DFAC433F5 for ; Fri, 28 Jan 2022 23:40:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351793AbiA1XkF (ORCPT ); Fri, 28 Jan 2022 18:40:05 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:47534 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235971AbiA1XkE (ORCPT ); Fri, 28 Jan 2022 18:40:04 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DBF6B61DD5; Fri, 28 Jan 2022 23:40:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 01578C340FA; Fri, 28 Jan 2022 23:40:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643413203; bh=oM29BnV9ToRiA87Xa8vy8Ps9akFPyNK8+ftmkwPDABQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ByH2OKYnBLJShtun1wY2/hje/k3qpSBktCbkbBFhJt+I1eDSwYZWhncN+2YEBotgp UieLA//E4zlEzUBKKNk1wboM8vHakppCj1SxDrPiZJ8gaxbWvhjA3Ir/ks+dpkFEqF VdiJpDiUSsdUlzylaZgoSJc4u0Km2ZB7ynv7ytUoeRp5HGW9d39cp7+t0VStVRxLdM R5g4Hel17nV1LzVP9xq+LXqrArP2ONxbnIefYXlqmhwLrGa4FkAF8wmYalUlyoLPnH uimhJD1dOK94KVt8Zhj1wwvVIozrMrt/b5kACue/LgRmkRRy9yn2Z3AbOd+wQ5t4uX MNMGudgBTVO+g== From: Eric Biggers To: linux-fscrypt@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, Theodore Ts'o , Jaegeuk Kim , Christoph Hellwig , "Darrick J . Wong" , Dave Chinner , Satya Tangirala Subject: [PATCH v11 3/5] ext4: support direct I/O with fscrypt using blk-crypto Date: Fri, 28 Jan 2022 15:39:38 -0800 Message-Id: <20220128233940.79464-4-ebiggers@kernel.org> X-Mailer: git-send-email 2.35.0 In-Reply-To: <20220128233940.79464-1-ebiggers@kernel.org> References: <20220128233940.79464-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Eric Biggers Encrypted files traditionally haven't supported DIO, due to the need to encrypt/decrypt the data. However, when the encryption is implemented using inline encryption (blk-crypto) instead of the traditional filesystem-layer encryption, it is straightforward to support DIO. Therefore, make ext4 support DIO on files that are using inline encryption. Since ext4 uses iomap for DIO, and fscrypt support was already added to iomap DIO, this just requires two small changes: - Let DIO proceed when supported, by checking fscrypt_dio_supported() instead of assuming that encrypted files never support DIO. - In ext4_iomap_begin(), use fscrypt_limit_io_blocks() to limit the length of the mapping in the rare case where a DUN discontiguity occurs in the middle of an extent. The iomap DIO implementation requires this, since it assumes that it can submit a bio covering (up to) the whole mapping, without checking fscrypt constraints itself. Co-developed-by: Satya Tangirala Signed-off-by: Satya Tangirala Reviewed-by: Jaegeuk Kim Acked-by: Theodore Ts'o Signed-off-by: Eric Biggers --- fs/ext4/file.c | 10 ++++++---- fs/ext4/inode.c | 7 +++++++ 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 8cc11715518ac..8bd66cdc41be2 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -36,9 +36,11 @@ #include "acl.h" #include "truncate.h" -static bool ext4_dio_supported(struct inode *inode) +static bool ext4_dio_supported(struct kiocb *iocb, struct iov_iter *iter) { - if (IS_ENABLED(CONFIG_FS_ENCRYPTION) && IS_ENCRYPTED(inode)) + struct inode *inode = file_inode(iocb->ki_filp); + + if (!fscrypt_dio_supported(iocb, iter)) return false; if (fsverity_active(inode)) return false; @@ -61,7 +63,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to) inode_lock_shared(inode); } - if (!ext4_dio_supported(inode)) { + if (!ext4_dio_supported(iocb, to)) { inode_unlock_shared(inode); /* * Fallback to buffered I/O if the operation being performed on @@ -509,7 +511,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from) } /* Fallback to buffered I/O if the inode does not support direct I/O. */ - if (!ext4_dio_supported(inode)) { + if (!ext4_dio_supported(iocb, from)) { if (ilock_shared) inode_unlock_shared(inode); else diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5f79d265d06a0..7af1bba34b8b8 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3409,6 +3409,13 @@ static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, if (ret < 0) return ret; out: + /* + * When inline encryption is enabled, sometimes I/O to an encrypted file + * has to be broken up to guarantee DUN contiguity. Handle this by + * limiting the length of the mapping returned. + */ + map.m_len = fscrypt_limit_io_blocks(inode, map.m_lblk, map.m_len); + ext4_set_iomap(inode, iomap, &map, offset, length, flags); return 0;