Re: reiser4progs do not handle the reiser4 format changes

[Edward Shishkin <edward@namesys.com>]

David Masover wrote:

> Edward Shishkin wrote:
>
>> Hans Reiser wrote:
>>
>>> Edward Shishkin wrote:
>>>
>>>  
>>>
>>>> David Masover wrote:
>>>>
>>>>  
>>>>
>>>>> E.Gryaznova wrote:
>>>>>
>>>>>    
>>>>>
>>>>>> Notification:
>>>>>>
>>>>>> The reiser4 format was changed in reiser4-for-2.6.11-5.patch and new
>>>>>> reiser4 kernel code is able to handle the old format.
>>>>>>       
>>>>>
>>>>>
>>>>>
>>>>> Good, so I don't have to reformat _immediately_...
>>>>>
>>>>> But, why isn't it for 2.6.12 yet?  We're already on at least
>>>>> 2.6.12.2, last I checked...
>>>>>
>>>>>    
>>>>>
>>>>>> The reiser4progs-1.0.4 are not able to handle the format changes.
>>>>>> The fix for reiser4progs will be ready next week.
>>>>>>       
>>>>>
>>>>>
>>>>>
>>>>> Will there be a conversion tool?
>>>>>
>>>>>
>>>>>     
>>>>
>>>>
>>>> No. Reiser4progs just will support a set of new plugins which have
>>>> been added to the kernel.
>>>> In particular, mkfs.reiser4 should allow user to specify the plugins
>>>> like other existing
>>>> ones. This will be a way to create cryptcompress files per superblock.
>>>> There is another
>>>> more flexible way (which is compatible with the previous one) to
>>>> create it per file/directory,
>>>> but it uses deprecated metas interface..
>>>> Note: since cryptcompress plugin is unstable, the new options are
>>>> supposed to be undocumented.
>>>>
>>>> Thanks,
>>>> Edward.
>>>>
>>>>
>>>>
>>>>   
>>>
>>>
>>> So why does this create a format change that breaks things?  I cannot
>>> see why it should do so, please explain.
>>>  
>>>
>>
>> I have lost a track who first called upgrading plugin_set by the 
>> terrible
>> words "disk format change". Plugin set is not a disk format, it is 
>> supposed
>> to be upgraded..
>
>
> Ok, please explain what this actually means for users.
>
> How will an FS made by the current reiser4progs be different than that 
> made by the new (patched) ones that will be coming out?  Is the new 
> way better?  If so, how can one take an existing FS and 
> convert/update/tweak it to the new way?
>

This is a common scenario:

Each disk reiser4 is supposed to be supported by all kernel/reiser4.
Both kernel and reiser4progs have a plugin table which should be 
upgraded in sync.
For each point A of upgrading the plugin table all reiser4progs of 
versions < A
become invalid for disk reiser4 being once mounted in the kernel/reiser4 
of version >= A.

Is it okay?
Perhaps introducing a special sub-versions of reiser4/reiser4progs for 
upgrading
the plugin table will improve the situation..


Edward.

>
>