Those following the evolution of the Reiser4 filesystem will be interested in learning that it has become "fairly stable for average users", so much so that Namesys is soon planning to push patches [story] to 2.6 kernel maintainer Andrew Morton [interview]. Once the two remaining known bugs are fixed, the warnings against using reiser4 on a production system will likely be removed. Hans Reiser explains:

"We have one NFS related bug remaining, and one mmap all of memory related bug (and performance issue) that you can hit using iozone. We will fix both of these in next week's snapshot, they were both multi-day bug fixes. When they are fixed, unless users/distros find bugs next week we will submit it for inclusion in the -mm and then the official kernel."

Hans goes on to note, "We need a lot more real user testers, because we have run out of scripts that can crash it, and there are distros that would like to ship it soon." Read on for the full thread, including links to the latest snapshot and changelog.

From: Nikita Danilov [email blocked]
To: Linux Kernel Mailing List [email blocked]
Subject: [ANNOUNCE] new reiser4 snapshot released.
Date: Fri, 26 Mar 2004 19:45:10 +0300

Hello,

new reiser4 snapshot against 2.6.5-rc2 is available at

http://www.namesys.com/snapshots/2004.03.26/

It is mainly bug-fixing release. See READ.ME for the list of fixes and
caveats.

Should no significant problems be found in this snapshot, we shall start
sending patches to -mm next week.

Nikita.



From: Hans Reiser [email blocked]
Subject: Reiser4 needs more testers
Date: Fri, 26 Mar 2004 09:05:05 -0800

We have one NFS related bug remaining, and one mmap all of memory 
related bug (and performance issue) that you can hit using iozone.  We 
will fix both of these in next week's snapshot, they were both multi-day 
bug fixes.  When they are fixed, unless users/distros find bugs next 
week we will submit it for inclusion in the -mm and then the official 
kernel.

We hope it is now fairly stable for average users if you avoid those two 
issues (we need to get rid of those dire warnings about its 
stability...., we will remember that next snapshot....;-) )

We need a lot more real user testers, because we have run out of scripts 
that can crash it, and there are distros that would like to ship it 
soon.  Please also complain to [email blocked] and [email blocked] 
about poor documentation, etc., ....

The new reiser4 snapshot (against 2.6.5-rc2) is available at

http://www.namesys.com/snapshots/2004.03.26/


-- 
Hans

From: Jonathan Briggs [email blocked]
Subject: Re: [ANNOUNCE] new reiser4 snapshot released.
Date: Fri, 26 Mar 2004 10:23:54 -0700

On Fri, 2004-03-26 at 09:45, Nikita Danilov wrote:
> Hello,
> 
> new reiser4 snapshot against 2.6.5-rc2 is available at
> 
> http://www.namesys.com/snapshots/2004.03.26/
> 
> It is mainly bug-fixing release. See READ.ME for the list of fixes and
> caveats.

A definition of fibration:
http://mathworld.wolfram.com/Fibration.html

I'm going to have to study math for about a year before I understand all
that, I think.

It's a good thing we won't have to understand "fiber bundles",
"paracompact topological space" and the "homotopy lifting property" to
USE Reiser4.

*grin*

If I missed the discussion or a web page, I am sorry.  But could someone
post a quick explanation or pointer to one about this fibration plugin? 
What does it do and what effects will it have?

-- 
Jonathan Briggs
[email blocked]



From: Nikita Danilov [email blocked]
Subject: Re: [ANNOUNCE] new reiser4 snapshot released.
Date: Fri, 26 Mar 2004 21:11:45 +0300

Jonathan Briggs writes:
 > On Fri, 2004-03-26 at 09:45, Nikita Danilov wrote:
 > > Hello,
 > > 
 > > new reiser4 snapshot against 2.6.5-rc2 is available at
 > > 
 > > http://www.namesys.com/snapshots/2004.03.26/
 > > 
 > > It is mainly bug-fixing release. See READ.ME for the list of fixes and
 > > caveats.
 > 
 > A definition of fibration:
 > http://mathworld.wolfram.com/Fibration.html

Reiser4 plugin was named this was due to some (arguably vague)
similarity with mathematical fibrations.

 > 
 > I'm going to have to study math for about a year before I understand all
 > that, I think.
 > 
 > It's a good thing we won't have to understand "fiber bundles",
 > "paracompact topological space" and the "homotopy lifting property" to
 > USE Reiser4.
 > 
 > *grin*

Why, of course one has to understand it. Reiser4 refuses to mount unless
supplied with the homotopy group of the tangent bundle of hard drive,
for sure.

 > 
 > If I missed the discussion or a web page, I am sorry.  But could someone
 > post a quick explanation or pointer to one about this fibration plugin? 
 > What does it do and what effects will it have?

Fibration plugin affects how disk blocks are allocated for the files
within the same directory. Basically, in reiser4 all file system data
and meta-data (except for allocator bitmaps) are stored in a single
balanced tree. Every piece of information in the file system (byte of
file data, on-disk inode, directory entry containing file name, etc.)
has a key that allows to locate this information in the tree. This
imposes natural order on all file system data (because keys are just
large integers, and can be compared).

Block allocator tries to allocate blocks in a parent-first tree
order. This means, that things with close keys have chances to be close
to each other on a disk. This leads to the main high-level mechanism
that reiser4 uses to control disk layout: through key assignment.

In particular fibration plugin is called when new name is inserted into
a directory, and, based on a name, selects some (otherwise unused) 7 bits
in a key of directory entry. This allows to "slice" directory content
into "fibers", hence the name.

For example, one possible implementation is to place .o files in one
fiber and all others in another. This significantly speeds compilations
up, because .o files are created close to each other and don't interfere
with sources. Fibrations, and well as other plugins, can be set
per-object, see http://www.namesys.com/v4/pseudo.html for details.

 > 
 > -- 
 > Jonathan Briggs
 > [email blocked]
 > 

Nikita.



From: Hans Reiser [email blocked]
Subject: Re: [ANNOUNCE] new reiser4 snapshot released.
Date: Fri, 26 Mar 2004 09:11:00 -0800

Nikita, would you confirm that the default fibration is to sort all 
files with '.' as the penultimate character by their last character 
first and then by the rest of the name in the usual lexicographic order? 
(If that is not the default, then please make it the default.)

Also, please note that the URL you supplied does not yet describe the 
fibration plugin and its available settings.  Please correct that on Monday.

-- 
Hans

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