[Dev] Removable block devices in TIZEN

Rusty Lynch rusty.lynch at intel.com
Tue Oct 8 16:12:09 GMT 2013


On Tue, 2013-10-08 at 14:59 +0200, Jacek Pielaszkiewicz wrote:
> Dear all,
> 
> 	I have created set of patches to implement udisks on TIZEN and
> replace removable block devices support in system-server by udisk. Main
> reason for the proposed changes is to implement in TIZEN common and well
> known functionalities that handle removable devices.
> 
> 	Implemented changes:
> 
> (1) System-server patch - remove support for block devices in system-server
> removal - remove udev rules that triggers action in system-server (rules for
> add/remove kernel events)
> 
> (2) Udisks - initial version of the udisks repository for TIZEN - version
> 2.1.2
> 
> (3) libatasmart - initial version of the libatasmart repository for TIZEN -
> version 0.19. The library is required by udisks.
> 
> (4) udisks-agent - my implementation of an simple agent that works in user
> space. It handles events triggered by the udisks (add/remove device). The
> agent provide very basic functionality - mount/unmount removable block
> device. Any notification is not send to end-user. The agent in assumption
> should be base for future works and closer integration with rest of TIZEN
> components. To avoid any security issue I added wide rules in polkit to
> allow every user mount removable block devices.
> 
> (5) polkit patch - add support in the polkit demon to be started by systemd.
> The polkit is required by udisks.
> 

I think this is the correct direction.  We have no need to handle this
fundamentally different then most other Linux instances out there.

> 
> 	Issues/topics that required future works:
> 
> (1) Multi user support (open topic for TIZEN 3.0)
> 
> (2) Which API should we exposed for TIZEN applications - native udisk API
> (dbus based) or build a new one on top of udisk API.

Lets not create another abstraction layer.  Native apps can just
directly call into the existing dbus API and web apps do not have direct
access to arbitrary storage.

> (3) In version 2.1.2 udisks has limited support for encrypted block devices
> (only setup and mount such devices). Should we add support for other
> operations like: initial encrypted block devices setup, in place
> encryption/decryption, etc?

Does the Tizen 2.2 phone already support such things?

> (4) Mount points location - by default udisks mount new block devices in
> /run/media/__user__/__device_name__ in TIZEN it is /opt/storage/sdcard -
> hardcoded. 

I think we should stop using the oddball location
under /opt/storage/sdcard and just fix whatever middleware is working
under this hard coded assumption.

> (5) Integration udisks with TIZEN security (security-server, ...)

Last I heard the security-server was marked for death, i.e. the overall
system was being addressed such that we should not need such a beast
anymore.  But... I'll let the security folks comment on that.

    --rusty



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