Hi, ----- Original Message ----- > From: "Anthony Jones" <[email protected]> > To: [email protected] > Sent: Monday, June 10, 2013 3:26:35 PM > Subject: Re: [b2g] Moving apps to the sdcard > > On Mon, Jun 10, 2013 at 9:23 AM, Mike Habicher <[email protected]> > wrote: > > On 13-06-10 12:18 PM, Jonas Sicking wrote: > > I think someone else has already mentioned that since USB mass > > storage mode > > mounts the SD card as a block device, there's no security we can > > provide to > > the contents of the SD card when the phone is plugged into a PC > > with USBMS > > enabled. > > Using a loopback device would allow us to use directory permissions. > If > we want the data to be non-transferable then we encrypt it and store > the > key on the main flash. Storing the encryption key in the network (or > the > SIM) would make it transferable.
I think that using a loopback device on a backing store that can go away unexpectedly is asking for all kinds of trouble. The user can remove the physical sdcard, which means that any unwritten data will not get written, and the looped file system will potentially be corrupted (you now have 2 filesystems that could have unwritten data - the FAT filesystem on the sdcard and the looped filesystem). FAT filesystems tend to be synchronous, i.e. all writes are flushed out as soon as possible, and android does a chkdsk on the sdcard everytime its inserted. We would need to do similar things to the looped storage area (i.e. flush out all writes as soon as possible, and do a manual chkdsk on the looped filesystem every time the sdcard is inserted. Dave Hylands _______________________________________________ dev-b2g mailing list [email protected] https://lists.mozilla.org/listinfo/dev-b2g
