Re: Adding subroot information to /proc/mounts, or obtaining that through other means

H. Peter Anvin
2007-06-20T21:24:44Z

Al Viro wrote:
> On Wed, Jun 20, 2007 at 01:57:33PM -0700, H. Peter Anvin wrote:
>> ... or, alternatively, add a subfield to the first field (which would
>> entail escaping whatever separator we choose):
>>
>> /dev/md6 /export ext3 rw,data=ordered 0 0
>> /dev/md6:/users/foo /home/foo ext3 rw,data=ordered 0 0
>> /dev/md6:/users/bar /home/bar ext3 rw,data=ordered 0 0
>
> Hell, no. The first field is in principle impossible to parse unless
> you know the fs type.
>
> How about making a new file with sane format? From the very
> beginning. E.g. mountpoint + ID + relative path + type + options,
> where ID uniquely identifies superblock (e.g. numeric st_dev)
> and backing device (if any) is sitting among the options...

Okay, I see there has been some discussion on this earlier, based on a
proposal by Ram Pai, so it pretty much comes down to redesigning this
right. I see some issues with his proposal (device numbers exported to
userspace in text form should be separated into major:minor form, for
one thing.) I know the util-linux-ng people have also had issues with
/proc/mounts that they would like resolved in order to finally nuke
/etc/mtab.

Is Ram still working on this? I'd like to help make this happen so we
can be done with it.

-hpa