HAL methods at storage device level, to mount/unmount/eject volumes

[Danny Kukawka]

On Friday 09 December 2005 18:49, David Zeuthen wrote:
> On Thu, 2005-12-08 at 20:20 +0100, Danny Kukawka wrote:
> > I discussed this already with Kay and we agree to extend the mount with
> > fstype to: Mount(string:directory, string:fstype, string:options).
> >
> > We need this at least to be able to mount with subfs, captive or fuse
> > (e.g. ntfsmount) so we work on a new version.
>
> So tell me why exactly is this useful? Why not just use the in-kernel
> ntfs driver? And why is it useful to use subfs?

From manpage of ntfsmount:
-----------------------------------------------------------------------
 ntfsmount is a FUSE module that rely on libntfs. You need FUSE to 
 compile it, xattr is recommended, but not mandatory. 

 Fully implemented ntfsmount features: 
  · Read-write access to normal and sparse files. 
  · Read-only access to compressed files. 
  · Access to special Interix files (symlinks, devices, FIFOs). 
  · List/Read/Write/Add/Remove named data streams. 
  · Supports Linux and FreeBSD. 
 
 Partly implemented features: 
  · Create/Delete/Move files and directories. · Hard link files.

[...]

 /etc/fstab entry: 
  /dev/hda5 /home/user/mnt ntfs-fuse ro,uid=1000 0 0
-----------------------------------------------------------------------

Some features of the kernel driver:
 - Full (read-only) support for sparse and compressed files also on 
   Windows XP/2003/2000.
But:
 - Still read-only, but with safe file overwrite support on all 
   Windows versions without changes to the file size (uncompressed, 
   unencrypted, nonsparse files only).

You can also get full write support for ntf with captive, but the project self 
is no longer under active development. Captive need LUFS, but there is IMO a 
experimental LUFS-FUSE bridge to get captive running. I used captive and LUFS 
at least with SUSE 9.2 and it worked perfect, I maybe test this with lufs 
bridge (lufis) in the next weeks.

IMO both are usefull to get well write access to ntfs and so we should support 
this. You can't autodetect this so you should support this from the desktop. 
And for this we need a way to specify the filesystem for the mount command.


And why it is usefull to mount with subfs? From the submount/subfs homepage:
-------------------------------------------------------------------
Submount is a system for automatically mounting and unmounting removable media 
drives like cdroms and floppy disk drives.  It works with the Linux 2.6 
kernel series. Once installed, it allows removable media drives to be 
accessed as if they were permanently mounted.
-------------------------------------------------------------------

SUSE use subfs/submout since a long time and also in the next releases to 
mount by default e.g. CD/DVD media. And it work(ed) well. For subfs you also 
need to specify the fstype: 

 /dev/cdrom /media/cdrom subfs 
			fs=cdfss,ro,procuid,nosuid,nodev,exec,iocharset=utf8 0 0

So why not support it?

Cheers,

Danny