From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 926DA8BBE0 for ; Thu, 27 Oct 2022 09:13:50 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 74874348A9 for ; Thu, 27 Oct 2022 09:13:50 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Thu, 27 Oct 2022 09:13:49 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 57D6044BF0 for ; Thu, 27 Oct 2022 09:13:49 +0200 (CEST) From: Fiona Ebner To: pve-devel@lists.proxmox.com Date: Thu, 27 Oct 2022 09:13:45 +0200 Message-Id: <20221027071345.12661-1-f.ebner@proxmox.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.028 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [proxmox.com, spinics.net, qemuserver.pm] Subject: [pve-devel] [PATCH v2 qemu-server] fix #4099: disable io_uring for virtual disks on CIFS storages X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Oct 2022 07:13:50 -0000 Since kernel 5.15, there is an issue with io_uring when used in combination with CIFS [0]. Unfortunately, the kernel developers did not suggest any way to resolve the issue and didn't comment on my proposed one. So for now, just disable io_uring when the storage is CIFS, like is done for other storage types that had problematic interactions. It is rather easy to reproduce when writing large amounts of data within the VM. I used dd if=/dev/urandom of=file bs=1M count=1000 to reproduce it consistently, but your mileage may vary. Some forum reports about users running into the issue [1][2][3]. [0]: https://www.spinics.net/lists/linux-cifs/msg26734.html [1]: https://forum.proxmox.com/threads/109848/ [2]: https://forum.proxmox.com/threads/110464/ [3]: https://forum.proxmox.com/threads/111382/ Signed-off-by: Fiona Ebner --- Changes from v1: * Add 'fix #4099'-prefix to commit title. PVE/QemuServer.pm | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm index 4e85dd02..513a248f 100644 --- a/PVE/QemuServer.pm +++ b/PVE/QemuServer.pm @@ -1665,8 +1665,12 @@ sub print_drive_commandline_full { # sometimes, just plain disable... my $lvm_no_io_uring = $scfg && $scfg->{type} eq 'lvm'; + # io_uring causes problems when used with CIFS since kernel 5.15 + # Some discussion: https://www.spinics.net/lists/linux-cifs/msg26734.html + my $cifs_no_io_uring = $scfg && $scfg->{type} eq 'cifs'; + if (!$drive->{aio}) { - if ($io_uring && !$rbd_no_io_uring && !$lvm_no_io_uring) { + if ($io_uring && !$rbd_no_io_uring && !$lvm_no_io_uring && !$cifs_no_io_uring) { # io_uring supports all cache modes $opts .= ",aio=io_uring"; } else { -- 2.30.2