From: Dominik Csapak <d.csapak@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [RFC PATCH common] sysfstools: file_write: properly catch errors
Date: Tue, 23 Jul 2024 10:29:25 +0200 [thread overview]
Message-ID: <20240723082925.934603-1-d.csapak@proxmox.com> (raw)
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 <d.csapak@proxmox.com>
---
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
reply other threads:[~2024-07-23 8:28 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240723082925.934603-1-d.csapak@proxmox.com \
--to=d.csapak@proxmox.com \
--cc=pve-devel@lists.proxmox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox