Re: [PATCH] common/rc: add default _udev_wait timeout

[David Disseldorp <ddiss@suse.de>]

On Fri, 20 Mar 2026 07:44:13 -0700, Darrick J. Wong wrote:
...
> > I normally have udevd running, but sometimes mess it up. My latest screw
> > up came from ommitting a "/run" dir in the initramfs test env, which
> > causes systemd-udevd to die on "/run/udev" creation. The error message
> > is hard to spot amoungst the other boot messages...  
> 
> Oh, ok.  For some reason I thought you were trying to run fstests
> without udev.  What if instead ./check looked for udevd and refused to
> proceed if it isn't running?  AFAIK even the anti-systemd distros ship
> eudev.

I've added the extra udevd sanity check to my test env, so I shouldn't
need anything in check. I'd expect NFS, SMB, CephFS, etc. may still want
to run without udevd.

> > > > The error message causes test failure via golden output mismatch and
> > > > is easier to debug than an infinite loop.
> > > > 
> > > > The timeout parameter is also compatible with existing
> > > > args="--removed <dev>" callers.
> > > > 
> > > > Signed-off-by: David Disseldorp <ddiss@suse.de>
> > > > ---
> > > >  common/rc | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/common/rc b/common/rc
> > > > index fd4ca964..aade0e5b 100644
> > > > --- a/common/rc
> > > > +++ b/common/rc
> > > > @@ -5544,7 +5544,7 @@ _udev_wait()
> > > >  	if [ -z "$UDEV_WAIT_PROG" ]; then
> > > >  		$UDEV_SETTLE_PROG >/dev/null 2>&1
> > > >  	else
> > > > -		$UDEV_WAIT_PROG $args
> > > > +		$UDEV_WAIT_PROG --timeout 10 $args    
> > > 
> > > ...a system running udevd that's taking forever to process rules can hit
> > > this 10 second timeout, at which point the test moves on and might just
> > > fail due to unconfigured /dev nodes.  
> > 
> > The 10 seconds is arbitrary. If there's a concern that the timeout will
> > prematurely fire on a regular systems then I'll gladly raise it up to a
> > minute or so. I just want to get an explicit failure instead of a
> > never-ending test.  
> 
> <nod>

I'd still like to see a timeout added, as a failed test (with timeout
msg) is IMO a far better outcome than an endless wait. Any objections if
I send a v2 patch with 60s timeout?

Thanks, David