Re: Locking of serial devices and devfs
On Thursday 21 June 2001 16:09, Wichert Akkerman wrote:
> Previously Cyrille Chepelov wrote:
> > ... until one uses a lean version of devfs, which doesn't have these
> > numbers, but just uses the pathname instead. Why design for a fragile
> > system ? Device names aren't going away.
>
> Using just names you loose since a single device can show up as
> multiple names.
True. The current code is provably broken in the case of sym-links.
/dev/modem is a very common sym-link. The current ppp code will create
LCK..modem for opening /dev/modem and LCK..ttyS0 for opening /dev/ttyS0,
if /dev/modem is a sym-link to /dev/ttyS0 then you're stuffed.
We could have our locking programs de-reference sym-links before creating
lock files, but that wouldn't work with hard links or multiple creations
of nodes. For example inserting a PCMCIA modem will create /dev/ttyS3 as
well as having devfs create /dev/tts/3...
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