Tested this together with the Nvidia vGPU series [0], so please consider this also:
Tested-by: Christoph Heiss <c.he...@proxmox.com> [0] https://lore.proxmox.com/pve-devel/ul3faxwxsi45hk4e44cl2fw4jomoncy53owx3you2wuvo7pymf@dchu53bqfa3p/T/#m2526c3a031aacc2f52080977febd432b4ab2efcf On Tue, Jul 23, 2024 at 10:29:25AM GMT, Dominik Csapak wrote: > 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.csa...@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. Actually catching errors here is definitely the right thing to do, IMHO. But as for not breaking existing callers, maybe a `warn` statement would be sensible? That way broken call-sites can be caught in the future and fixed as necessary. So a `noerr` parameter and `warn` if that is unset. > > 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 > > _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
