From patchwork Fri Oct 13 16:04:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13421454 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 706E1CDB47E for ; Fri, 13 Oct 2023 16:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231166AbjJMQ0T (ORCPT ); Fri, 13 Oct 2023 12:26:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58116 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230281AbjJMQ0K (ORCPT ); Fri, 13 Oct 2023 12:26:10 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 460062D5F for ; Fri, 13 Oct 2023 09:06:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697213211; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OIFHeTgUMwtSvY+j42oOHHXzZS1S7Lc7r7uKXM72kUQ=; b=Xu4lGPpNyuiB3bgGvVjYJj1WDuOVHcyih0LV9Ue/iyKCYblgB1Qp/Vu+P6f18B4k0fa+qy adllP8qrJNAf9WsGhtUD7l8ISmv/n101S8br7mIkJutaU0//qQPZg+il01rH4Cni4g3fGR sPICjCssFDuiSYKt9O+AAEsgxOPWLPs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-439-jK_A197JMJ2pqz6S6X0F5A-1; Fri, 13 Oct 2023 12:06:42 -0400 X-MC-Unique: jK_A197JMJ2pqz6S6X0F5A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A39C01029F59; Fri, 13 Oct 2023 16:06:28 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1C0E72157F5A; Fri, 13 Oct 2023 16:06:26 +0000 (UTC) From: David Howells To: Jeff Layton , Steve French Cc: David Howells , Matthew Wilcox , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Dominique Martinet , Ilya Dryomov , Christian Brauner , linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-cachefs@redhat.com Subject: [RFC PATCH 35/53] netfs: Perform content encryption Date: Fri, 13 Oct 2023 17:04:04 +0100 Message-ID: <20231013160423.2218093-36-dhowells@redhat.com> In-Reply-To: <20231013160423.2218093-1-dhowells@redhat.com> References: <20231013160423.2218093-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org When dealing with an encrypted file, we gather together sufficient pages from the pagecache to constitute a logical crypto block, allocate a bounce buffer and then ask the filesystem to encrypt between the buffers. The bounce buffer is then passed to the filesystem to upload. The network filesystem must set a flag to indicate what service is desired and what the logical blocksize will be. The netfs library iterates through each block to be processed, providing a pair of scatterlists to describe the start and end buffers. Note that it should be possible in future to encrypt DIO writes also by this same mechanism. Signed-off-by: David Howells cc: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- fs/netfs/Makefile | 1 + fs/netfs/buffered_write.c | 3 +- fs/netfs/crypto.c | 89 ++++++++++++++++++++++++++++++++++++ fs/netfs/internal.h | 5 ++ fs/netfs/objects.c | 2 + fs/netfs/output.c | 7 ++- include/linux/netfs.h | 11 +++++ include/trace/events/netfs.h | 2 + 8 files changed, 118 insertions(+), 2 deletions(-) create mode 100644 fs/netfs/crypto.c diff --git a/fs/netfs/Makefile b/fs/netfs/Makefile index d5c2809fc029..5ea852ac276c 100644 --- a/fs/netfs/Makefile +++ b/fs/netfs/Makefile @@ -3,6 +3,7 @@ netfs-y := \ buffered_read.o \ buffered_write.o \ + crypto.o \ direct_read.o \ direct_write.o \ io.o \ diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c index 7163fcc05206..b81d807f89f0 100644 --- a/fs/netfs/buffered_write.c +++ b/fs/netfs/buffered_write.c @@ -77,7 +77,8 @@ static enum netfs_how_to_modify netfs_how_to_modify(struct netfs_inode *ctx, if (!maybe_trouble && offset == 0 && len >= flen) return NETFS_WHOLE_FOLIO_MODIFY; - if (file->f_mode & FMODE_READ) + if (file->f_mode & FMODE_READ || + test_bit(NETFS_ICTX_ENCRYPTED, &ctx->flags)) return NETFS_JUST_PREFETCH; if (netfs_is_cache_enabled(ctx) || diff --git a/fs/netfs/crypto.c b/fs/netfs/crypto.c new file mode 100644 index 000000000000..943d01f430e2 --- /dev/null +++ b/fs/netfs/crypto.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Network filesystem content encryption support. + * + * Copyright (C) 2023 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include +#include +#include +#include +#include +#include "internal.h" + +/* + * Populate a scatterlist from the next bufferage of an I/O iterator. + */ +static int netfs_iter_to_sglist(const struct iov_iter *iter, size_t len, + struct scatterlist *sg, unsigned int n_sg) +{ + struct iov_iter tmp_iter = *iter; + struct sg_table sgtable = { .sgl = sg }; + ssize_t ret; + + _enter("%zx/%zx", len, iov_iter_count(iter)); + + sg_init_table(sg, n_sg); + ret = extract_iter_to_sg(&tmp_iter, len, &sgtable, n_sg, 0); + if (ret < 0) + return ret; + sg_mark_end(&sg[sgtable.nents - 1]); + return sgtable.nents; +} + +/* + * Prepare a write request for writing. We encrypt in/into the bounce buffer. + */ +bool netfs_encrypt(struct netfs_io_request *wreq) +{ + struct netfs_inode *ctx = netfs_inode(wreq->inode); + struct scatterlist source_sg[16], dest_sg[16]; + unsigned int n_dest; + size_t n, chunk, bsize = 1UL << ctx->crypto_bshift; + loff_t pos; + int ret; + + _enter(""); + + trace_netfs_rreq(wreq, netfs_rreq_trace_encrypt); + + pos = wreq->start; + n = wreq->len; + _debug("ENCRYPT %llx-%llx", pos, pos + n - 1); + + for (; n > 0; n -= chunk, pos += chunk) { + chunk = min(n, bsize); + + ret = netfs_iter_to_sglist(&wreq->io_iter, chunk, + dest_sg, ARRAY_SIZE(dest_sg)); + if (ret < 0) + goto error; + n_dest = ret; + + if (test_bit(NETFS_RREQ_CRYPT_IN_PLACE, &wreq->flags)) { + ret = ctx->ops->encrypt_block(wreq, pos, chunk, + dest_sg, n_dest, + dest_sg, n_dest); + } else { + ret = netfs_iter_to_sglist(&wreq->iter, chunk, + source_sg, ARRAY_SIZE(source_sg)); + if (ret < 0) + goto error; + ret = ctx->ops->encrypt_block(wreq, pos, chunk, + source_sg, ret, + dest_sg, n_dest); + } + + if (ret < 0) + goto error_failed; + } + + return true; + +error_failed: + trace_netfs_failure(wreq, NULL, ret, netfs_fail_encryption); +error: + wreq->error = ret; + return false; +} diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index 6a67abdf71c8..3f4e64968623 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -22,6 +22,11 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq); int netfs_prefetch_for_write(struct file *file, struct folio *folio, size_t offset, size_t len); +/* + * crypto.c + */ +bool netfs_encrypt(struct netfs_io_request *wreq); + /* * direct_write.c */ diff --git a/fs/netfs/objects.c b/fs/netfs/objects.c index c1218b183197..6bf3b3f51499 100644 --- a/fs/netfs/objects.c +++ b/fs/netfs/objects.c @@ -44,6 +44,8 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, refcount_set(&rreq->ref, 1); __set_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags); + if (test_bit(NETFS_ICTX_ENCRYPTED, &ctx->flags)) + __set_bit(NETFS_RREQ_CONTENT_ENCRYPTION, &rreq->flags); if (cached) __set_bit(NETFS_RREQ_WRITE_TO_CACHE, &rreq->flags); if (file && file->f_flags & O_NONBLOCK) diff --git a/fs/netfs/output.c b/fs/netfs/output.c index bb42789c7a24..2d2530dc9507 100644 --- a/fs/netfs/output.c +++ b/fs/netfs/output.c @@ -366,7 +366,11 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait, * background whilst we generate a list of write ops that we want to * perform. */ - // TODO: Encrypt or compress the region as appropriate + if (test_bit(NETFS_RREQ_CONTENT_ENCRYPTION, &wreq->flags) && + !netfs_encrypt(wreq)) { + may_wait = true; + goto out; + } /* We need to write all of the region to the cache */ if (test_bit(NETFS_RREQ_WRITE_TO_CACHE, &wreq->flags)) @@ -378,6 +382,7 @@ int netfs_begin_write(struct netfs_io_request *wreq, bool may_wait, if (test_bit(NETFS_RREQ_UPLOAD_TO_SERVER, &wreq->flags)) ctx->ops->create_write_requests(wreq, wreq->start, wreq->len); +out: if (atomic_dec_and_test(&wreq->nr_outstanding)) netfs_write_terminated(wreq, false); diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 6244f7a9a44a..cdb471938225 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -19,6 +19,7 @@ #include #include +struct scatterlist; enum netfs_sreq_ref_trace; /* @@ -141,7 +142,9 @@ struct netfs_inode { unsigned long flags; #define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */ #define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */ +#define NETFS_ICTX_ENCRYPTED 2 /* The file contents are encrypted */ unsigned char min_bshift; /* log2 min block size for bounding box or 0 */ + unsigned char crypto_bshift; /* log2 of crypto block size */ }; /* @@ -285,6 +288,8 @@ struct netfs_io_request { #define NETFS_RREQ_USE_BOUNCE_BUFFER 8 /* Use bounce buffer */ #define NETFS_RREQ_WRITE_TO_CACHE 9 /* Need to write to the cache */ #define NETFS_RREQ_UPLOAD_TO_SERVER 10 /* Need to write to the server */ +#define NETFS_RREQ_CONTENT_ENCRYPTION 11 /* Content encryption is in use */ +#define NETFS_RREQ_CRYPT_IN_PLACE 12 /* Enc/dec in place in ->io_iter */ const struct netfs_request_ops *netfs_ops; void (*cleanup)(struct netfs_io_request *req); }; @@ -316,6 +321,11 @@ struct netfs_request_ops { void (*create_write_requests)(struct netfs_io_request *wreq, loff_t start, size_t len); void (*invalidate_cache)(struct netfs_io_request *wreq); + + /* Content encryption */ + int (*encrypt_block)(struct netfs_io_request *wreq, loff_t pos, size_t len, + struct scatterlist *source_sg, unsigned int n_source, + struct scatterlist *dest_sg, unsigned int n_dest); }; /* @@ -464,6 +474,7 @@ static inline void netfs_inode_init(struct netfs_inode *ctx, ctx->zero_point = ctx->remote_i_size; ctx->flags = 0; ctx->min_bshift = 0; + ctx->crypto_bshift = 0; #if IS_ENABLED(CONFIG_FSCACHE) ctx->cache = NULL; #endif diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h index 60f98c99fe21..70e2f9a48f24 100644 --- a/include/trace/events/netfs.h +++ b/include/trace/events/netfs.h @@ -41,6 +41,7 @@ EM(netfs_rreq_trace_assess, "ASSESS ") \ EM(netfs_rreq_trace_copy, "COPY ") \ EM(netfs_rreq_trace_done, "DONE ") \ + EM(netfs_rreq_trace_encrypt, "ENCRYPT") \ EM(netfs_rreq_trace_free, "FREE ") \ EM(netfs_rreq_trace_redirty, "REDIRTY") \ EM(netfs_rreq_trace_resubmit, "RESUBMT") \ @@ -76,6 +77,7 @@ EM(netfs_fail_copy_to_cache, "copy-to-cache") \ EM(netfs_fail_dio_read_short, "dio-read-short") \ EM(netfs_fail_dio_read_zero, "dio-read-zero") \ + EM(netfs_fail_encryption, "encryption") \ EM(netfs_fail_read, "read") \ EM(netfs_fail_short_read, "short-read") \ EM(netfs_fail_prepare_write, "prep-write") \