From patchwork Fri Jan 28 23:39:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12729262 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 E5579C433EF for ; Fri, 28 Jan 2022 23:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351787AbiA1XkF (ORCPT ); Fri, 28 Jan 2022 18:40:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230352AbiA1XkE (ORCPT ); Fri, 28 Jan 2022 18:40:04 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 150E5C061714; Fri, 28 Jan 2022 15:40:04 -0800 (PST) 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 E47D361F28; Fri, 28 Jan 2022 23:40:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03707C340E8; Fri, 28 Jan 2022 23:40:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643413202; bh=yiJ5auAF7JlzipXtd7lawfYtaCcPGJqBWUK7WtxVTJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XdMaShpIV4mcMhEEUMQ+vmfTLdENDgUwM4qV149wNeY7xw8aE6S5zgQ1DNLvS2He+ JXLPtrbLOwALBQtzm45D58Dco9sOCUgIVINqAW9unbiplh6y4ATbb+S8FphWg06v3G sm8TgSoft6a/6d3UqG0gJBmSudZrHHCREL/4bFe+L32I9MANMQE5L24lElKTiEV2L8 ZkM2V9txAiN3jkZDU0Jklr/7y62Z9skQgDd66R92uKE1GzkYHOnMFYzJdmihTO9quC dr83hY4EzsmkedIW1PMg7KHDFgd6sl3jYVtwA4JCiiAghr+odI786ET/Hba2HUz4lh T+ZAs3Dq0CKqg== 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 1/5] fscrypt: add functions for direct I/O support Date: Fri, 28 Jan 2022 15:39:36 -0800 Message-Id: <20220128233940.79464-2-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. In preparation for supporting this, add the following functions: - fscrypt_dio_supported() checks whether a DIO request is supported as far as encryption is concerned. Encrypted files will only support DIO when inline encryption is used and the I/O request is properly aligned; this function checks these preconditions. - fscrypt_limit_io_blocks() limits the length of a bio to avoid crossing a place in the file that a bio with an encryption context cannot cross due to a DUN discontiguity. This function is needed by filesystems that use the iomap DIO implementation (which operates directly on logical ranges, so it won't use fscrypt_mergeable_bio()) and that support FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32. Co-developed-by: Satya Tangirala Signed-off-by: Satya Tangirala Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig --- fs/crypto/crypto.c | 8 ++++ fs/crypto/inline_crypt.c | 93 ++++++++++++++++++++++++++++++++++++++++ include/linux/fscrypt.h | 18 ++++++++ 3 files changed, 119 insertions(+) diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 4ef3f714046aa..4fcca79f39aeb 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -69,6 +69,14 @@ void fscrypt_free_bounce_page(struct page *bounce_page) } EXPORT_SYMBOL(fscrypt_free_bounce_page); +/* + * Generate the IV for the given logical block number within the given file. + * For filenames encryption, lblk_num == 0. + * + * Keep this in sync with fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks() + * needs to know about any IV generation methods where the low bits of IV don't + * simply contain the lblk_num (e.g., IV_INO_LBLK_32). + */ void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num, const struct fscrypt_info *ci) { diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index c57bebfa48fea..93c2ca8580923 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -17,6 +17,7 @@ #include #include #include +#include #include "fscrypt_private.h" @@ -315,6 +316,10 @@ EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh); * * fscrypt_set_bio_crypt_ctx() must have already been called on the bio. * + * This function isn't required in cases where crypto-mergeability is ensured in + * another way, such as I/O targeting only a single file (and thus a single key) + * combined with fscrypt_limit_io_blocks() to ensure DUN contiguity. + * * Return: true iff the I/O is mergeable */ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, @@ -363,3 +368,91 @@ bool fscrypt_mergeable_bio_bh(struct bio *bio, return fscrypt_mergeable_bio(bio, inode, next_lblk); } EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh); + +/** + * fscrypt_dio_supported() - check whether a DIO (direct I/O) request is + * supported as far as encryption is concerned + * @iocb: the file and position the I/O is targeting + * @iter: the I/O data segment(s) + * + * Return: %true if there are no encryption constraints that prevent DIO from + * being supported; %false if DIO is unsupported. (Note that in the + * %true case, the filesystem might have other, non-encryption-related + * constraints that prevent DIO from actually being supported.) + */ +bool fscrypt_dio_supported(struct kiocb *iocb, struct iov_iter *iter) +{ + const struct inode *inode = file_inode(iocb->ki_filp); + const unsigned int blocksize = i_blocksize(inode); + + /* If the file is unencrypted, no veto from us. */ + if (!fscrypt_needs_contents_encryption(inode)) + return true; + + /* We only support DIO with inline crypto, not fs-layer crypto. */ + if (!fscrypt_inode_uses_inline_crypto(inode)) + return false; + + /* + * Since the granularity of encryption is filesystem blocks, the file + * position and total I/O length must be aligned to the filesystem block + * size -- not just to the block device's logical block size as is + * traditionally the case for DIO on many filesystems. + * + * We require that the user-provided memory buffers be filesystem block + * aligned too. It is simpler to have a single alignment value required + * for all properties of the I/O, as is normally the case for DIO. + * Also, allowing less aligned buffers would imply that data units could + * cross bvecs, which would greatly complicate the I/O stack, which + * assumes that bios can be split at any bvec boundary. + */ + if (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), blocksize)) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(fscrypt_dio_supported); + +/** + * fscrypt_limit_io_blocks() - limit I/O blocks to avoid discontiguous DUNs + * @inode: the file on which I/O is being done + * @lblk: the block at which the I/O is being started from + * @nr_blocks: the number of blocks we want to submit starting at @lblk + * + * Determine the limit to the number of blocks that can be submitted in a bio + * targeting @lblk without causing a data unit number (DUN) discontiguity. + * + * This is normally just @nr_blocks, as normally the DUNs just increment along + * with the logical blocks. (Or the file is not encrypted.) + * + * In rare cases, fscrypt can be using an IV generation method that allows the + * DUN to wrap around within logically contiguous blocks, and that wraparound + * will occur. If this happens, a value less than @nr_blocks will be returned + * so that the wraparound doesn't occur in the middle of a bio, which would + * cause encryption/decryption to produce wrong results. + * + * Return: the actual number of blocks that can be submitted + */ +u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks) +{ + const struct fscrypt_info *ci; + u32 dun; + + if (!fscrypt_inode_uses_inline_crypto(inode)) + return nr_blocks; + + if (nr_blocks <= 1) + return nr_blocks; + + ci = inode->i_crypt_info; + if (!(fscrypt_policy_flags(&ci->ci_policy) & + FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) + return nr_blocks; + + /* With IV_INO_LBLK_32, the DUN can wrap around from U32_MAX to 0. */ + + dun = ci->ci_hashed_ino + lblk; + + return min_t(u64, nr_blocks, (u64)U32_MAX + 1 - dun); +} +EXPORT_SYMBOL_GPL(fscrypt_limit_io_blocks); diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 91ea9477e9bd2..50d92d805bd8c 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -714,6 +714,10 @@ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, bool fscrypt_mergeable_bio_bh(struct bio *bio, const struct buffer_head *next_bh); +bool fscrypt_dio_supported(struct kiocb *iocb, struct iov_iter *iter); + +u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks); + #else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ static inline bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode) @@ -742,6 +746,20 @@ static inline bool fscrypt_mergeable_bio_bh(struct bio *bio, { return true; } + +static inline bool fscrypt_dio_supported(struct kiocb *iocb, + struct iov_iter *iter) +{ + const struct inode *inode = file_inode(iocb->ki_filp); + + return !fscrypt_needs_contents_encryption(inode); +} + +static inline u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, + u64 nr_blocks) +{ + return nr_blocks; +} #endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */ /** From patchwork Fri Jan 28 23:39:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12729266 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 C98ABC433FE for ; Fri, 28 Jan 2022 23:40:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344347AbiA1XkN (ORCPT ); Fri, 28 Jan 2022 18:40:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230352AbiA1XkH (ORCPT ); Fri, 28 Jan 2022 18:40:07 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6405AC06173B; Fri, 28 Jan 2022 15:40:05 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 1F08BB8272E; Fri, 28 Jan 2022 23:40:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7DD01C340EF; 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=1643413202; bh=nHFxT7m7n/PO9ZU3JSReFnLKGQ9T4BVIVZVRwmNnf2g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fj+13BS78mdCrmo5S6M/b382/MAfnkitlX3HyZoWmg4D+9S0x/95C5cct4w4L9zBW VjsPvxInYpZiwtX4aOKrk/DlSBmvh6e4WBo34Pdv1quVkpRO1NW/F7WTht7toJ+SoG IsWT0ATowuzfE57mX9sMPlYEQaGPf3HDehY7aecPAI93s3dtWaVQPd1vbJCa8uhglS nufOl+TZz3h/qsbsVyjEBWtnDXq2teEP/DMidl5gsMnWNaCEG24rXCxMzWNLHn1DPN 8os7U5SMIGS1+SJu5EgxfDU+HQS7FnKhlNduWLwTVnCzBNZdQghd1dWynd4il7K2T2 BXrL26K8jIJ+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 2/5] iomap: support direct I/O with fscrypt using blk-crypto Date: Fri, 28 Jan 2022 15:39:37 -0800 Message-Id: <20220128233940.79464-3-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. Add support for this to the iomap DIO implementation by calling fscrypt_set_bio_crypt_ctx() to set encryption contexts on the bios. Don't check for the rare case where a DUN (crypto data unit number) discontiguity creates a boundary that bios must not cross. Instead, filesystems are expected to handle this in ->iomap_begin() by limiting the length of the mapping so that iomap doesn't have to worry about it. Co-developed-by: Satya Tangirala Signed-off-by: Satya Tangirala Acked-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Eric Biggers --- fs/iomap/direct-io.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 03ea367df19a4..20325b3926fa3 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include #include @@ -179,11 +180,14 @@ static void iomap_dio_bio_end_io(struct bio *bio) static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio, loff_t pos, unsigned len) { + struct inode *inode = file_inode(dio->iocb->ki_filp); struct page *page = ZERO_PAGE(0); int flags = REQ_SYNC | REQ_IDLE; struct bio *bio; bio = bio_alloc(GFP_KERNEL, 1); + fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, + GFP_KERNEL); bio_set_dev(bio, iter->iomap.bdev); bio->bi_iter.bi_sector = iomap_sector(&iter->iomap, pos); bio->bi_private = dio; @@ -310,6 +314,8 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, } bio = bio_alloc(GFP_KERNEL, nr_pages); + fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, + GFP_KERNEL); bio_set_dev(bio, iomap->bdev); bio->bi_iter.bi_sector = iomap_sector(iomap, pos); bio->bi_write_hint = dio->iocb->ki_hint; 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; From patchwork Fri Jan 28 23:39:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12729265 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 2BADAC4321E for ; Fri, 28 Jan 2022 23:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351790AbiA1XkK (ORCPT ); Fri, 28 Jan 2022 18:40:10 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:43464 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243675AbiA1XkH (ORCPT ); Fri, 28 Jan 2022 18:40:07 -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 ams.source.kernel.org (Postfix) with ESMTPS id 028A0B82722; Fri, 28 Jan 2022 23:40:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77C0AC340F2; Fri, 28 Jan 2022 23:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643413203; bh=LuDFDhqfRMf5XNrJxODhsKvMEoMr5mmsePqMCFxBMwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=m4mBSoJ6eUvtHyPrP4gwPfdZRKUbE5cORinvPjBDH3fLCbfPpOsgdEK9mfPgXiatk +IOvMbz45hpLUufIIFh591vHBZKCWrpJr6UVb2daSwOfq6apsXEeZdxG1AM2sTCrSD 9jMU34IAOJrl/oVzg1IVzS+ZgXp+7Wfrjx6lerJYkN9y/1oC1KuG2EZPkYv9nbaRX1 Ao4IFDkkteu8DugSNoKhIX75sxHXmlyKyu2+Um1GKfCjVsBSPAWo4PRkUtJkaXuRBK R8xzXV6+/s/aGrLoVLdGbQXKayJ0i+z2ZnFcHcRTisC6ds2XE64tcwMP5ZqMQP/OxO Gk7gN9UpoWejA== 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 4/5] f2fs: support direct I/O with fscrypt using blk-crypto Date: Fri, 28 Jan 2022 15:39:39 -0800 Message-Id: <20220128233940.79464-5-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 f2fs support DIO on files that are using inline encryption. Since f2fs 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 f2fs_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 Signed-off-by: Eric Biggers Acked-by: Jaegeuk Kim --- fs/f2fs/data.c | 7 +++++++ fs/f2fs/f2fs.h | 6 +++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8c417864c66ae..020d47f97969c 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -4044,6 +4044,13 @@ static int f2fs_iomap_begin(struct inode *inode, loff_t offset, loff_t length, iomap->offset = blks_to_bytes(inode, map.m_lblk); + /* + * 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); + if (map.m_flags & (F2FS_MAP_MAPPED | F2FS_MAP_UNWRITTEN)) { iomap->length = blks_to_bytes(inode, map.m_len); if (map.m_flags & F2FS_MAP_MAPPED) { diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index eb22fa91c2b26..db46f3cf0885d 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4371,7 +4371,11 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, struct f2fs_sb_info *sbi = F2FS_I_SB(inode); int rw = iov_iter_rw(iter); - if (f2fs_post_read_required(inode)) + if (!fscrypt_dio_supported(iocb, iter)) + return true; + if (fsverity_active(inode)) + return true; + if (f2fs_compressed_file(inode)) return true; /* disallow direct IO if any of devices has unaligned blksize */ From patchwork Fri Jan 28 23:39:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 12729264 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 A74ADC433F5 for ; Fri, 28 Jan 2022 23:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351808AbiA1XkK (ORCPT ); Fri, 28 Jan 2022 18:40:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241190AbiA1XkF (ORCPT ); Fri, 28 Jan 2022 18:40:05 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1899C061714; Fri, 28 Jan 2022 15:40:04 -0800 (PST) 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 6F84261F2E; Fri, 28 Jan 2022 23:40:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF1C5C340E8; Fri, 28 Jan 2022 23:40:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643413204; bh=spfZ0C7Zzj01hpeB+SKGd/oodc1v3r1noyh70XVyPBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r2Pk9YJCttEO3LXCWN96An7pNpeozJNfzD23KRTrHMV4ZDMWkGzZptp9dr+An7tHk AT7joZu6qGP3AlKNTtjhVXZr6d7kRRqTTijWcyXgYlXw2Kbj+gwNfWj6etyiOvYyXO zXvVSwby5N6+/nPPzvCxS4JqAHAI7z9cpk1jfcRsypsUtvpr4sAothr5bYJRXrsR9l cJ618VQ3o8Bt2meiuZCADNKl8Vv+EaHKGCNETgm7GqFQL2Oams+5KMQ+J9eLQG3+2c 1AZRvJA6RVW0wa5BwmjzWu9JSsc3QH1lUEBg9IB25aqfT1p0uOuuJ757Oso4Yk7te2 ZtCemJbi/UbuA== 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 Subject: [PATCH v11 5/5] fscrypt: update documentation for direct I/O support Date: Fri, 28 Jan 2022 15:39:40 -0800 Message-Id: <20220128233940.79464-6-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 Now that direct I/O is supported on encrypted files in some cases, document what these cases are. Signed-off-by: Eric Biggers Reviewed-by: Christoph Hellwig --- Documentation/filesystems/fscrypt.rst | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 4d5d50dca65c6..6ccd5efb25b77 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -1047,8 +1047,8 @@ astute users may notice some differences in behavior: may be used to overwrite the source files but isn't guaranteed to be effective on all filesystems and storage devices. -- Direct I/O is not supported on encrypted files. Attempts to use - direct I/O on such files will fall back to buffered I/O. +- Direct I/O is supported on encrypted files only under some + circumstances. For details, see `Direct I/O support`_. - The fallocate operations FALLOC_FL_COLLAPSE_RANGE and FALLOC_FL_INSERT_RANGE are not supported on encrypted files and will @@ -1179,6 +1179,27 @@ Inline encryption doesn't affect the ciphertext or other aspects of the on-disk format, so users may freely switch back and forth between using "inlinecrypt" and not using "inlinecrypt". +Direct I/O support +================== + +For direct I/O on an encrypted file to work, the following conditions +must be met (in addition to the conditions for direct I/O on an +unencrypted file): + +* The file must be using inline encryption. Usually this means that + the filesystem must be mounted with ``-o inlinecrypt`` and inline + encryption hardware must be present. However, a software fallback + is also available. For details, see `Inline encryption support`_. + +* The I/O request must be fully aligned to the filesystem block size. + This means that the file position the I/O is targeting, the lengths + of all I/O segments, and the memory addresses of all I/O buffers + must be multiples of this value. Note that the filesystem block + size may be greater than the logical block size of the block device. + +If either of the above conditions is not met, then direct I/O on the +encrypted file will fall back to buffered I/O. + Implementation details ======================