From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CEEBCCD8C9D for ; Mon, 8 Jun 2026 16:53:00 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wWdDB-000163-Qi; Mon, 08 Jun 2026 12:52:29 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wWdDA-00015T-7N for qemu-devel@nongnu.org; Mon, 08 Jun 2026 12:52:28 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wWdD8-0007Qw-LW for qemu-devel@nongnu.org; Mon, 08 Jun 2026 12:52:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1780937546; 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=BdkstQtJlrBa9g+LfmT+wxquA4LIIzMoYHUWQrCrWMg=; b=iJaXZiy0lFZVJiJYiJ76lk6oKMlUctkQ6499as2W++H8SAgAaTDcynupPfuXWQBlpickQG kyi0p+Srsg9e5arf06z/VSDVZt0T3Q3d+HCWA6QAE3YwqDeS7y57B34tsf+MNa7MDchUeC +Ip+ylQGWLgqSrLTZsSGuLNTuPHJF7U= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-569-Iftsn9zoOVaMd_bkKVgrWQ-1; Mon, 08 Jun 2026 12:52:24 -0400 X-MC-Unique: Iftsn9zoOVaMd_bkKVgrWQ-1 X-Mimecast-MFC-AGG-ID: Iftsn9zoOVaMd_bkKVgrWQ_1780937543 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7EFAD195411C; Mon, 8 Jun 2026 16:52:23 +0000 (UTC) Received: from merkur.fritz.box (unknown [10.44.50.32]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 2274C19540CB; Mon, 8 Jun 2026 16:52:21 +0000 (UTC) From: Kevin Wolf To: qemu-block@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com, qemu-devel@nongnu.org Subject: [PULL 6/8] block/export/fuse: set FUSE_DIRECT_IO_ALLOW_MMAP flag to fix regression Date: Mon, 8 Jun 2026 18:52:05 +0200 Message-ID: <20260608165207.307488-7-kwolf@redhat.com> In-Reply-To: <20260608165207.307488-1-kwolf@redhat.com> References: <20260608165207.307488-1-kwolf@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 8 X-Spam_score: 0.8 X-Spam_bar: / X-Spam_report: (0.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.445, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Fiona Ebner Commit 8599559580 ("fuse: Set direct_io and parallel_direct_writes") broke use cases that require mmap() with MAP_SHARED on the export. In particular, swtpm_setup using its 'file://' protocol requires this. >From the kernel documentation [0]: > To allow shared mmap, the FUSE_DIRECT_IO_ALLOW_MMAP flag may be > enabled in the FUSE_INIT reply. Set the FUSE_DIRECT_IO_ALLOW_MMAP flag to restore compatibility with users requiring shared mmap. The FUSE_INIT_EXT flag needs to be set for the flags2 member to have an effect. [0]: https://www.kernel.org/doc/html/next/filesystems/fuse/fuse-io.html Cc: qemu-stable@nongnu.org Fixes: 8599559580 ("fuse: Set direct_io and parallel_direct_writes") Signed-off-by: Fiona Ebner Message-ID: <20260506145424.10249-3-f.ebner@proxmox.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/export/fuse.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/block/export/fuse.c b/block/export/fuse.c index 35218e31976..c0e8dfb6430 100644 --- a/block/export/fuse.c +++ b/block/export/fuse.c @@ -856,7 +856,8 @@ static ssize_t coroutine_fn GRAPH_RDLOCK fuse_co_init(FuseExport *exp, struct fuse_init_out *out, const struct fuse_init_in *in) { - const uint32_t supported_flags = FUSE_ASYNC_READ | FUSE_ASYNC_DIO; + uint32_t supported_flags = FUSE_ASYNC_READ | FUSE_ASYNC_DIO; + uint32_t flags2 = 0; if (in->major != 7) { error_report("FUSE major version mismatch: We have 7, but kernel has %" @@ -871,13 +872,21 @@ fuse_co_init(FuseExport *exp, struct fuse_init_out *out, return -EINVAL; } + if (!using_old_fuse_init_in(in)) { + /* The flags2 flags must be shifted down by 32 bits. */ + const uint32_t supported_flags2 = FUSE_DIRECT_IO_ALLOW_MMAP >> 32; + /* flags2 is only considered if FUSE_INIT_EXT is set. */ + supported_flags = supported_flags | FUSE_INIT_EXT; + flags2 = in->flags2 & supported_flags2; + } + *out = (struct fuse_init_out) { .major = 7, .minor = MIN(FUSE_KERNEL_MINOR_VERSION, in->minor), .max_readahead = in->max_readahead, .max_write = FUSE_MAX_WRITE_BYTES, .flags = in->flags & supported_flags, - .flags2 = 0, + .flags2 = flags2, /* libfuse maximum: 2^16 - 1 */ .max_background = UINT16_MAX, -- 2.54.0