From patchwork Fri Oct 13 16:04:06 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13421409 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 5C677CDB482 for ; Fri, 13 Oct 2023 16:14:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232127AbjJMQO6 (ORCPT ); Fri, 13 Oct 2023 12:14:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231670AbjJMQOx (ORCPT ); Fri, 13 Oct 2023 12:14:53 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 271172682 for ; Fri, 13 Oct 2023 09:06:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1697213201; 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=QdFa/dxqwrihf1ZMFwRJBWJsl8hSozQZEOt+FKZWmzU=; b=NTsrLxJntmmIl3yHiSzgz6bTNlf5hk+qlkbQAQcSAgmb2JyRjW2EbDGeDjzJWScr/YJ97Z xbysfnN74XYdX2Vjf//+Trvis64gqVTGj3+jc4QYxD2CHXErqQa+ruQcOpRvGi0OPu3EHS smb8wnyTn4joPrUTuK2UldB/UrvZZUc= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-354-bIkAoftxPQSMUL0pN1n9yw-1; Fri, 13 Oct 2023 12:06:38 -0400 X-MC-Unique: bIkAoftxPQSMUL0pN1n9yw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (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 76A6A1C09A56; Fri, 13 Oct 2023 16:06:37 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.226]) by smtp.corp.redhat.com (Postfix) with ESMTP id E310525C1; Fri, 13 Oct 2023 16:06:33 +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 37/53] netfs: Support decryption on ubuffered/DIO read Date: Fri, 13 Oct 2023 17:04:06 +0100 Message-ID: <20231013160423.2218093-38-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 3.4.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org Support unbuffered and direct I/O reads from an encrypted file. This may require making a larger read than is required into a bounce buffer and copying out the required bits. We don't decrypt in-place in the user buffer lest userspace interfere and muck up the decryption. 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/direct_read.c | 10 ++++++++++ fs/netfs/internal.h | 17 +++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c index 52ad8fa66dd5..158719b56900 100644 --- a/fs/netfs/direct_read.c +++ b/fs/netfs/direct_read.c @@ -181,6 +181,16 @@ static ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_ iov_iter_advance(iter, orig_count); } + /* If we're going to do decryption or decompression, we're going to + * need a bounce buffer - and if the data is misaligned for the crypto + * algorithm, we decrypt in place and then copy. + */ + if (test_bit(NETFS_RREQ_CONTENT_ENCRYPTION, &rreq->flags)) { + if (!netfs_is_crypto_aligned(rreq, iter)) + __set_bit(NETFS_RREQ_CRYPT_IN_PLACE, &rreq->flags); + __set_bit(NETFS_RREQ_USE_BOUNCE_BUFFER, &rreq->flags); + } + /* If we're going to use a bounce buffer, we need to set it up. We * will then need to pad the request out to the minimum block size. */ diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index 8dc68a75d6cd..7dd37d3aff3f 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -196,6 +196,23 @@ static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr) netfs_group->free(netfs_group); } +/* + * Check to see if a buffer aligns with the crypto unit block size. If it + * doesn't the crypto layer is going to copy all the data - in which case + * relying on the crypto op for a free copy is pointless. + */ +static inline bool netfs_is_crypto_aligned(struct netfs_io_request *rreq, + struct iov_iter *iter) +{ + struct netfs_inode *ctx = netfs_inode(rreq->inode); + unsigned long align, mask = (1UL << ctx->min_bshift) - 1; + + if (!ctx->min_bshift) + return true; + align = iov_iter_alignment(iter); + return (align & mask) == 0; +} + /*****************************************************************************/ /* * debug tracing