kern/120869: [procfs] 'stat' shows that all files have 0-length
when they are actually not empty
Bruce Evans
brde at optusnet.com.au
Thu Feb 21 10:20:05 UTC 2008
The following reply was made to PR kern/120869; it has been noted by GNATS.
From: Bruce Evans <brde at optusnet.com.au>
To: Robert Watson <rwatson at FreeBSD.org>
Cc: Bruce Evans <brde at optusnet.com.au>, remko at FreeBSD.org,
freebsd-fs at FreeBSD.org, yuri at tsoft.com, bug-followup at FreeBSD.org
Subject: Re: kern/120869: [procfs] 'stat' shows that all files have 0-length
when they are actually not empty
Date: Thu, 21 Feb 2008 21:11:46 +1100 (EST)
On Thu, 21 Feb 2008, Robert Watson wrote:
> On Thu, 21 Feb 2008, Bruce Evans wrote:
>>> [about files in procfs]
>> The bug is mainly that stat() claims that the files are regular when they
>> highly irregular (they are more like fifos). This confuses naive
>> applications into thinking that normal access methods for regular files
>> actually work.
>
> I feel this way more generally about synthetic file systems with objects in
> them that don't correspond with any of the standard file system objects that
> applications known how to deal with.
Enough to break compatibility/portabiility by adding a new file type? :-)
S_IFMT has 4 bits, so it could encode 16 file types, but it currently only
encodes 8. It looks like it once had only 3 bits but was expanded for
fifos. It was last changed in ~1993 in 4.4BSD to add whiteouts.
Bruce
More information about the freebsd-fs
mailing list