lkml.org 
[lkml]   [2001]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: devfs and /proc/ide/hda
From
Date
>>>>> " " == AJ Lewis <lewis@sistina.com> writes:

> On Wed, Feb 28, 2001 at 04:10:23PM +0100, Guest section DW
> wrote:
>> On Wed, Feb 28, 2001 at 08:52:54PM +1100, Glenn McGrath wrote:
>>
>> > Im running kernel 2.4.1, I have entries like /proc/ide/hda, >
>> /proc/ide/ide0/hda etc irrespective of wether im using devfs or
>> > traditional device names. > > Is always using traditional
>> device names for /proc/ide intentional, or > is it something
>> nobody has gotten around to fixing yet?
>>
>> If only humans look at /proc, and they like typing long names,
>> then there is no objection against changing /proc. As it is,
>> however, quite a few programs look at /proc for information
>> about devices. I don't think it would be a good idea to "fix"
>> /proc and simultaneously break all these programs.
> What it should do is change based on whether devfs is mounted
> or not. It doesn't make *any* sense to have
> /dev/ide/host0/foo/bar in your /proc/partitions entries if you
> aren't mounting devfs. The /proc/partitions entry is the only
> way I know of for something like LVM to determine which devices
> to scan for Volume Groups. If you can't read /proc/partitions,
> it has to attempt to scan all block devices it recognizes,
> regardless of whether they are actually on the system or not.
> This can take several minutes.
First:

% cat /proc/partitions
major minor #blocks name

3 0 20010816 ide/host0/bus0/target0/lun0/disc
3 1 192748 ide/host0/bus0/target0/lun0/part1
3 2 249007 ide/host0/bus0/target0/lun0/part2
3 3 1 ide/host0/bus0/target0/lun0/part3
3 5 289138 ide/host0/bus0/target0/lun0/part5
3 6 1951866 ide/host0/bus0/target0/lun0/part6
3 7 979933 ide/host0/bus0/target0/lun0/part7
3 8 16346106 ide/host0/bus0/target0/lun0/part8
33 0 80043264 ide/host2/bus0/target0/lun0/disc
33 1 80035798 ide/host2/bus0/target0/lun0/part1

So its already right.

Secondly with devfs, why not just scan all /dev/discs/?

% ls -l /dev/discs
total 0
lr-xr-xr-x 1 root root 30 Jan 1 1970 disc0 -> ../ide/host0/bus0/target0/lun0/
lr-xr-xr-x 1 root root 30 Jan 1 1970 disc1 -> ../ide/host2/bus0/target0/lun0/

Also if lvm opens all known devices by way of /dev/whatever while
scanning, it will only find existing devices there with devfs.

MfG
Goswin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:52    [from the cache]
©2003-2011 Jasper Spaans