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 ECE77707D6 for ; Wed, 22 Jun 2022 10:45:24 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id EA41DDA2E for ; Wed, 22 Jun 2022 10:45:24 +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) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id B85C1DA06 for ; Wed, 22 Jun 2022 10:45:23 +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 8D41143C5A for ; Wed, 22 Jun 2022 10:45:16 +0200 (CEST) From: Fabian Ebner To: pve-devel@lists.proxmox.com Date: Wed, 22 Jun 2022 10:45:11 +0200 Message-Id: <20220622084513.160867-2-f.ebner@proxmox.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220622084513.160867-1-f.ebner@proxmox.com> References: <20220622084513.160867-1-f.ebner@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SPAM-LEVEL: Spam detection results: 0 AWL 0.046 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 T_SCC_BODY_TEXT_LINE -0.01 - Subject: [pve-devel] [PATCH v2 qemu 1/3] vma: create: support 64KiB-unaligned input images 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: Wed, 22 Jun 2022 08:45:25 -0000 which fixes backing up templates with such disks in PVE, for example efitype=4m EFI disks on a file-based storage (size = 540672). If there is not enough left to read, blk_co_preadv will return -EIO, so limit the size in the last iteration. For writing, an unaligned end is already handled correctly. The call to memset is not strictly necessary, because writing also checks that it doesn't write data beyond the end of the image. But there are two reasons to do it: 1. It's cleaner that way. 2. It allows detecting when the final piece is all zeroes, which might not happen if the buffer still contains data from the previous iteration. Signed-off-by: Fabian Ebner --- Changes from v1: * Add assert just to be sure. vma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/vma.c b/vma.c index 21e765a469..6d02b29047 100644 --- a/vma.c +++ b/vma.c @@ -548,7 +548,7 @@ static void coroutine_fn backup_run(void *opaque) struct iovec iov; QEMUIOVector qiov; - int64_t start, end; + int64_t start, end, readlen; int ret = 0; unsigned char *buf = blk_blockalign(job->target, VMA_CLUSTER_SIZE); @@ -562,8 +562,16 @@ static void coroutine_fn backup_run(void *opaque) iov.iov_len = VMA_CLUSTER_SIZE; qemu_iovec_init_external(&qiov, &iov, 1); + if (start + 1 == end) { + memset(buf, 0, VMA_CLUSTER_SIZE); + readlen = job->len - start * VMA_CLUSTER_SIZE; + assert(readlen > 0 && readlen <= VMA_CLUSTER_SIZE); + } else { + readlen = VMA_CLUSTER_SIZE; + } + ret = blk_co_preadv(job->target, start * VMA_CLUSTER_SIZE, - VMA_CLUSTER_SIZE, &qiov, 0); + readlen, &qiov, 0); if (ret < 0) { vma_writer_set_error(job->vmaw, "read error", -1); goto out; -- 2.30.2