eSATA auto mounting

[Phillip Susi]

On 6/13/2011 10:45 AM, David Zeuthen wrote:
> First is that there is no reliable way you can determine whether a
> SATA drive is connected via an eSATA connector or not. So we shouldn't
> even be trying. Even laptops for which the AHCI data will give you
> some hints (cf. bit 21 in 3.3.7 of the AHCI 1.3 spec, "External SATA
> Port (ESP)") seem to lie about it. Presumably because laptop vendors
> don't fill in the right data which is probably because Windows don't
> use it. I don't know.

Just because some hardware is broken doesn't mean you should ignore the 
flag specified by the standard.  My Dell netbook gets it right.  Those 
who have broken hardware I am sure would appreciate a workaround 
allowing them to override, but those with hardware that complies with 
the standard would appreciate their eSATA drives working correctly.

> This is why the DeviceIsSystemInternal property, this one
>
>   http://hal.freedesktop.org/docs/udisks/Device.html#Device:DeviceIsSystemInternal
>
> talks about "heuristics". Note that this property will be removed in
> udisks in the next ABI break (2.0). So we shouldn't be assuming that
> we know such things (e.g. whether it is connected via eSATA) about a
> disk drive, so we shouldn't be basing policy (e.g. whether to
> automount or not) on it since we cannot know.

So you are saying that the policy of auto mounting external drives and 
not internal ones is fundamentally broken and must go away?  Why not fix 
it to work correctly rather than remove the feature?

> Disagree because the kernel shouldn't be reporting its guesses to the user.

It isn't a guess; it is hardware information.  Arguing against reporting 
it is like arguing that the kernel should not report that a drive claims 
to use 4kb sectors.  The fact that some drives lie and claim they use 
512 bytes when they are in fact, 4kb, is not a reason to ignore drives 
that comply with the standard.