Old ATA disk names emulation [Was: Switch from legacy ata(4) to CAM-based ATA]

[Alexander Motin]

Andrey V. Elsukov wrote:
> On 25.04.2011 14:23, Alexander Motin wrote:
>> What will not work:
>>  - old device names won't be seen inside GEOM, so users who hardcoded
>> provider names in gmirror/gstripe/... metadata (not the default
>> behavior) are still in trouble.
>>  - patch mimics ATA_STATIC_ID behavior, if user had custom kernel
>> without it, he should update device names manually.
>>  - it won't work for users with hot-unplugging ATA controllers (not
>> devices), but I believe it is really rare case.
>>  - low-level tools, such as smartmontools, won't be able to work with
>> alias devices, as background ada driver doesn't implements legacy
>> ioctls. May be I could partially fix this.
>>
>> Except those, I think this patch should work for the most of users.
>>
>> Any more objections/ideas? Is this an acceptable solution?
> 
> what about new GEOM class? You can create new class instance after
> disk_alloc(), attach it to the new disk and create provider with old-style
> name. It seems this class will be very simple.

It sounds like less dirty option. I'll try it. Thank you. Won't
re-providing exactly the same device into GEOM create some problems?
glabel and co will connect to each of them (original and legacy) and
report two equal sets of labels.

-- 
Alexander Motin