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 13163B169 for ; Thu, 29 Jun 2023 12:32:51 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id E11563E8B2 for ; Thu, 29 Jun 2023 12:32:20 +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, 29 Jun 2023 12:32:20 +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 EFC5541F93 for ; Thu, 29 Jun 2023 12:32:19 +0200 (CEST) From: =?UTF-8?q?Fabian=20Gr=C3=BCnbichler?= To: pbs-devel@lists.proxmox.com Date: Thu, 29 Jun 2023 12:32:13 +0200 Message-Id: <20230629103213.1041236-1-f.gruenbichler@proxmox.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.071 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy 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 T_SCC_BODY_TEXT_LINE -0.01 - Subject: [pbs-devel] [PATCH proxmox-backup] mapped loop device: use read loop instead of read_exact X-BeenThere: pbs-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox Backup Server development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Jun 2023 10:32:51 -0000 since read_exact does not support short reads, which can easily happen if the mapped image's EOF is not aligned with the request size. Signed-off-by: Fabian Grünbichler --- Notes: reported on the forum: https://forum.proxmox.com/threads/problem-backing-up-using-backup-client.129347 did a quick test reading from a mapped image full of random data, observed no performance difference.. pbs-fuse-loop/src/fuse_loop.rs | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/pbs-fuse-loop/src/fuse_loop.rs b/pbs-fuse-loop/src/fuse_loop.rs index 3d0ef123..7e780799 100644 --- a/pbs-fuse-loop/src/fuse_loop.rs +++ b/pbs-fuse-loop/src/fuse_loop.rs @@ -188,13 +188,20 @@ impl FuseLoopSession { match self.reader.seek(SeekFrom::Start(req.offset)).await { Ok(_) => { let mut buf = vec![0u8; req.size]; - match self.reader.read_exact(&mut buf).await { - Ok(_) => { - req.reply(&buf) - }, - Err(e) => { - req.io_fail(e) + let mut read = 0; + let mut res = Ok(()); + while read < req.size && res.is_ok() { + match self.reader.read(&mut buf).await { + Ok(0) => { break; }, + Ok(n) => { read += n; }, + Err(e) => { res = Err(e); }, } + }; + if let Err(e) = res { + req.io_fail(e) + } else { + buf.truncate(read); + req.reply(&buf) } }, Err(e) => { -- 2.39.2