exposing Windows mountpoints in Cygwin

Fri Feb 7 10:43:57 GMT 2025

On Feb 7 11:11, Corinna Vinschen via Cygwin wrote:
> On Feb 6 13:31, Jeremy Drake via Cygwin wrote:
> > Now that my patch to escape characters in /proc/mounts has been applied,
> > I'll get back to what I was thinking about back in June. I would like to
> > have a way to list Windows volume roots in Cygwin, and it seems to make
> > sense to me to expose them via getmntent, /proc/mounts, etc. The way I
> > see this working is probably to replace the available_drives mechanism for
> > enumerating mounts in favor of using FindFirst/NextVolumeW and
> > GetVolumePathNamesForVolumeNameW to enumerate cygdrive mount points.
>> Been there, done that, but that was more than 10 years ago, so things
> might have changed. At the time, the volume manager was incredibly
> slow. Enumerating and converting volume paths from one style into the
> other just took too much time. And, as you know, Cygwin already is
> slow...
>> Still, if you want to do that, it should not be part of the standard
> mount points becasue this is another level of implementation. These are
> the POSIX mount points handled by Cygwin. That should be part of the
> cygdrive handling. Sounds like you were mulling over this anyway.
>> But it's not quite clear what the expected output should be. On this
> userspace level, we have no use for Volume paths ("\\?\Volume{UUID}"),
> and we have no use for the devices ("\\?\HarddiskVolume1").
>> And, you can already visit this info without even having to use
> the volume manager, by just looking up the NT namespace, as the
> /proc/sys emulation does, for instance:
>> $ ls -gG /proc/sys/GLOBAL\?\?/ | grep 'Volume{'
> lr--r--r-- 1 0 Feb 7 11:11 Volume{0bd61b5f-949e-4c06-9ebe-13aa68abb838} -> /proc/sys/Device/HarddiskVolume4
> lr--r--r-- 1 0 Feb 7 11:11 Volume{437ef40c-9169-4b0c-94ee-d894aae17c56} -> /proc/sys/Device/HarddiskVolume1
> lr--r--r-- 1 0 Feb 7 11:11 Volume{a326a87c-0f80-4d14-a91a-a95e822c1a60} -> /proc/sys/Device/HarddiskVolume3
> lr--r--r-- 1 0 Feb 7 11:11 Volume{adccf9db-e210-11ef-81ad-806e6f6e6963} -> /proc/sys/Device/CdRom0

Oh, and in terms of identifying the drives, we have this nice /de/disk
addition from Christian, try `ls -l /dev/disk/*'.
>> So what is the expected output in the cygdrive dir?
>> What I could imagine is something like this. Assuming two drives, one
> of them mounted into a dir:
>> C:		\Device\HarddiskVolume1
> C:\foo	\Device\HarddiskVolume2
>> $ ls -gG /cygdrive
> d---r-x---+ 1 0 Feb 7 03:38 c
> drwxrwxr-x 1 0 Jan 8 11:02 c_foo -> /mnt/c/foo
>> but other than that...
>>> Corinna
>> -- 
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