From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 7014C1FF2CA for ; Tue, 23 Jul 2024 10:28:56 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 84E133E759; Tue, 23 Jul 2024 10:29:29 +0200 (CEST) From: Dominik Csapak To: pve-devel@lists.proxmox.com Date: Tue, 23 Jul 2024 10:29:25 +0200 Message-Id: <20240723082925.934603-1-d.csapak@proxmox.com> X-Mailer: git-send-email 2.39.2 MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.016 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 URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [sysfstools.pm] Subject: [pve-devel] [RFC PATCH common] sysfstools: file_write: properly catch errors 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: , Reply-To: Proxmox VE development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" since `print` is doing buffered IO, we don't always get an error there, even if the underlying write does not work. To properly catch that, do an unbuffered `syswrite` which circumvents all buffers and writes directly to the file handle. We aren't actually interested in the specific error here, but only if the write was successful or not. Signed-off-by: Dominik Csapak --- Note: this is heavily used when doing PCI passthrough, and it seems we did not catch as many errors as we thought. Maybe we should introduce an 'noerr' parameter and pass that on all current code paths, since i fear that there are many situations where the sysfs write had failed but it still works because we ignored it and qemu/the kernel do the right thing anyway. src/PVE/SysFSTools.pm | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/PVE/SysFSTools.pm b/src/PVE/SysFSTools.pm index 57f0ac8..8eb9f2e 100644 --- a/src/PVE/SysFSTools.pm +++ b/src/PVE/SysFSTools.pm @@ -198,7 +198,7 @@ sub file_write { my $fh = IO::File->new($filename, "w"); return undef if !$fh; - my $res = print $fh $buf; + my $res = defined(syswrite($fh, $buf)) ? 1 : 0; $fh->close(); -- 2.39.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel