Re: reiser4 plugins

David Masover
2005-07-06T20:53:10Z

Hans Reiser wrote:
> David Masover wrote:
>
>
>>And, once we start talking about applications, /meta will be more
>>readily supported (as in, some apps will go through a pathname and
>>stop when they get to a file, and then there's tar). On apps which
>>don't have direct support for /meta, you'd be navigating to the file
>>in question and then manually typing '...' into the dialog, so I don't
>>see why typing '...' at the end is better than typing '/meta' or
>>'/meta/vfs' at the beginning.
>
>
> Performance. If you type it at the end, and you already have done the
> lookup of the filename, then you can go from the file to one of its
> methods, instead of a complete new traversal of another tree under /meta

Only, it's a different view of the same tree. That may not matter
performance-wise, though.

Also, for performance-critical applications, the /meta tree is pretty
easy -- it becomes more like /meta/inode/some_inode_number/.

There's also the chroot issue, though.

>>That said, I'm still not entirely sure how we get /meta/vfs to work
>>other than adding a '...' sort of delimiter anyway.
>>
>>
>>>>And a question: is it feasible to store, for each inode, its parent(s),
>>>>instead of just the hard link count?
>>>>
>>>>
>>>
>>>Ooh, now that is an interesting old idea I haven't considered in 20
>>>years.... makes fsck more robust too....
>>
>>
>>Doesn't it make directory operations slower, too?
>
>
> Not sure. It consumes space though.
>
>
>>And, will it require a format change?
>>
>
> Yes, but we have plugins now, so.....

So, will the format change happen at mount time? Will it need a special
mount flag? Will I need to use debugfs or some other offline tool?