testing/questions about latest Reiser4

testing/questions about latest Reiser4

[Grant Miner]

Does Reiser4 store stat data in real files, or some special way?  Are 
pseudo files just representation of stat data stored a special way?  Is 
it possible to do streams/forks with a plugin easily?

I mounted latest Reiser4 snapshot + linux 2.6.4 with acl and xattr 
options but when I tried "getfattr" I received "operation not supported"?

I'm using Reiser4 as root fs for some days now, and it is great!  Only 
problem is whenever I run 'make' it always recompiles everything; 
perhaps this has to do with time stamps?  Oh and fibration is cool :) 
How do I switch to the other fibration plugins for a directory?

Re: testing/questions about latest Reiser4

[Vladimir Saveliev]

Hello

On Mon, 2004-04-05 at 08:48, Grant Miner wrote:
> Does Reiser4 store stat data in real files, or some special way?

files are built of items. Every file has item of stat data type. So,
reiser4 stores stat data as an item.

>   Are 
> pseudo files just representation of stat data stored a special way? 

Pseudo files are not stored anywhere

>  Is 
> it possible to do streams/forks with a plugin easily?
> 
> I mounted latest Reiser4 snapshot + linux 2.6.4 with acl and xattr 
> options but when I tried "getfattr" I received "operation not supported"?
> 
reiser4 does not support xattrs. You may try to #define XATTR (1) in
fs/reiser4/reiser4.h and try to mount with -o xattr. This code was
disabled sometime ago. So, it is not guarantted to work.

> I'm using Reiser4 as root fs for some days now, and it is great!  Only 
> problem is whenever I run 'make' it always recompiles everything;

I just tried to compile reiserfsprogs, and it worked as expected. Can
you, please, say more how to reproduce this problem?

>  
> perhaps this has to do with time stamps?  Oh and fibration is cool :) 
> How do I switch to the other fibration plugins for a directory?
> 

echo -n 'ext-3\0' > ./metas/plugin/fibration

Re: testing/questions about latest Reiser4

[Valdis.Kletnieks]

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On Mon, 05 Apr 2004 19:23:08 +0400, Vladimir Saveliev said:

> >   Are 
> > pseudo files just representation of stat data stored a special way? 
> 
> Pseudo files are not stored anywhere

Subtle distinction here - the data in a pseudo file has to be stored
*somewhere* if you want it to persist across reboots, and even for things that
don't survive a reboot, the data has to be saved *someplace* in memory, even if
it's only in a variable or a dentry structure or something like that....

So more accurate might be to say "The content of pseudo files is created on the
fly from metadata that is managed (and possibly saved) by the file system".

(Sorry to be pedantic, but it's a point that will cause a lot of confusion if you
don't really understand it)...

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Re: testing/questions about latest Reiser4

[Vladimir Saveliev]

Hello

On Tue, 2004-04-06 at 03:00, Valdis.Kletnieks@vt.edu wrote:
> On Mon, 05 Apr 2004 19:23:08 +0400, Vladimir Saveliev said:
> 
> > >   Are 
> > > pseudo files just representation of stat data stored a special way? 
> > 
> > Pseudo files are not stored anywhere
> 
> Subtle distinction here - the data in a pseudo file has to be stored
> *somewhere* if you want it to persist across reboots, and even for things that
> don't survive a reboot, the data has to be saved *someplace* in memory, even if
> it's only in a variable or a dentry structure or something like that....
> 
> So more accurate might be to say "The content of pseudo files is created on the
> fly from metadata that is managed (and possibly saved) by the file system".
> 

Yes, thanks, I should have said something like that

> (Sorry to be pedantic, but it's a point that will cause a lot of confusion if you
> don't really understand it)...

Re: testing/questions about latest Reiser4

[Hans Reiser]

Grant Miner wrote:

> Does Reiser4 store stat data in real files, or some special way?

It presents stat data to user space as a file (or via stat()), but below 
the fs interface it stores it in a stat item, which you can think of as 
a compressed format for stat files.

>   Are pseudo files just representation of stat data stored a special 
> way?  Is it possible to do streams/forks with a plugin easily?
>
> I mounted latest Reiser4 snapshot + linux 2.6.4 with acl and xattr 
> options but when I tried "getfattr" I received "operation not supported"?
>
> I'm using Reiser4 as root fs for some days now, and it is great!  Only 
> problem is whenever I run 'make' it always recompiles everything; 
> perhaps this has to do with time stamps?

Probably, talk to vs about it, ok?

>   Oh and fibration is cool :) How do I switch to the other fibration 
> plugins for a directory?
>
>


-- 
Hans