[systemd-devel] What does udevd do

[Andrei Borzenkov]

В Sun, 31 May 2015 10:26:46 +0800
cee1 <fykcee1 at gmail.com> пишет:

> 2015-05-31 5:52 GMT+08:00 Lennart Poettering <lennart at poettering.net>:
> >> Then udevd is only responsible for
> >> 1) Making nodes, and doing other device initialization stuffs.
> >
> > udev does not create device nodes. That's the job of devtmpfs in the
> > kernel. udev will however apply access modes/acls/fix ownership create
> > symlinks and so on.
> 
> That means ** all ** dev nodes are there when devtmpfs is mounted?
> I thought devtmpfs makes a limited number of nodes for early boot-up.
> 
> 
> 

Not as a general rule but my distribution still has e.g.

/usr/lib/tmpfiles.d/parallel-printer.conf:c    /dev/lp0	 0660 root lp 	- 6:0
/usr/lib/tmpfiles.d/parallel-printer.conf:c    /dev/lp1  	 0660 root lp 	- 6:1
/usr/lib/tmpfiles.d/parallel-printer.conf:c    /dev/lp2  	 0660 root lp   - 6:2
/usr/lib/tmpfiles.d/parallel-printer.conf:c    /dev/lp3  	 0660 root lp   - 6:3

But that is rather exceptional case.