Linux with Android MTP

[E.S. Rosenberg]

With MTP and similar stuff on cameras a lot of GUIs on different
platforms don't even offer unmount options, and yes fsck wouldn't do
anything since you don't have access to the filesystem, only to a
software layer in front of the filesystem (which also helps the device
OS protects its' files).

2013/10/24 Oleg Goldshmidt <pub at goldshmidt.org>:
> "E.S. Rosenberg" <esr+linux-il at g.jct.ac.il> writes:
>
>> Always unmounting properly is obviously best practise but isn't the
>> whole point of mtp that unmount isn't strictly needed since you are
>> not interacting with the fs but rather with some daemon on the device,
>> so worst that can happen when you unplug is a corrupt file?
>
> As far as I understand MTP is supposed to act as a transactional
> filesystem, i.e., if you want to modify a file you operate on a copy and
> then write the whole file or nothing. Potentially slow, of course. The
> actual filesystem is implemented on the device and not on the host. This
> indicates - theoretically! - that you may be right.[1]
>
> I *read* that Google's MTP implementation on Android extends the
> standard to avoid the potentially expensive copying of whole files back
> and forth.[2] If that is the case then maybe properly unmounting is
> prudent, after all. Maybe (I do not *know*) you still cannot damage the
> filesystem itself, but you *may* be able to corrupt files.
>
> Disclaimer: I don't really know the details - do not believe my words
> without checking on your own.
>
> [1] This also means, I *suppose*, that fsck on the host will not help
>     you out if the filesystem on your device gets corrupted.
>
> [2] It is not clear to me whether all the Android manufacturers
>     implement these extensions. Again, I *read somewhere*[3] that
>     Samsung do not.
>
> [3] Oh, hell, what is Google for? http://intr.overt.org/blog/?p=174 -
>     NB: this is the GNOME/GVFS guy, simple-mtpfs may be different.
>
> --
> Oleg Goldshmidt | pub at goldshmidt.org