Re: [dm-devel] [linux-lvm] do not disable ext4 discards on first discard failure? [was: Re: dm snapshot: ignore discards issued to the snapshot-origin target]

[Eric Sandeen <sandeen redhat com>]

On 4/28/11 5:59 PM, Alasdair G Kergon wrote:
> On Thu, Apr 28, 2011 at 04:28:17PM -0500, Eric Sandeen wrote:
>> I still think that concats of floppies, usb disks, and ssds should be rare, so I'm less concerned about that ;)
> 
> It's the 'undefined' cases that cause us the trouble though: we do have
> to return something and I prefer to work with defined and documented
> behaviour, rather than pretending something is 'undefined' or
> 'unimportant' and later finding people relied on its actual behaviour.

If you are saying that a target should return EOPNOTSUPP when it does not support the operation, then we are in violent agreement.   :)

-Eric
 
> Alasdair