Hi Martin, Dirk, Paolo, (and Leituviu?) -

I wasn't thinking and didn't include recent committers to the testdisk

and partclone packages in my initial post.  Neither has a listed

maintainer for the openSUSE packages.  I'd like feedback on whether

libreiserfs support can be dropped from these packages.

The TL;DR version of the below is that I inherited libreiserfs at some

point.  I haven't maintained it except for a small build fix years ago

and will not maintain it.  libreiserfs is only used as a direct

dependency by these two packages.  It was a transitive dependency via

parted, but that dependency has been obsolete since 2011 and I've pushed

an SR to fix that.  Reiserfs support for the dozen or so other packages

that require it is provided by the libreiserfscore0 library from the

'reiserfs' package that I do maintain.  The libreiserfs package is an

abandoned project that has no official location from which to download

it and hasn't been updated since 2004 except when people notice the

build has broken and fix it.

The alternatives to dropping support for libreiserfs is that someone

else steps up to maintain it or someone steps up to port the reiserfs

functionality to libreiserfscore0.  The functionality in partclone is

pretty trivial but the functionality in testdisk is more involved (and

has to be buggy already, based on the interfaces).

Thanks,

-Jeff

On 3/19/21 12:25 PM, Jeff Mahoney wrote:

On 3/19/21 12:09 PM, Neal Gompa wrote:

On Fri, Mar 19, 2021 at 12:01 PM Jeff Mahoney <jeffm@suse.com> wrote:

Hi all -

I'm technically the maintainer for the libreiserfs package.  Outside of

a minor build fix years ago, I've had nothing to do with it.  Best I can

tell, it was originally brought in for parted in 2005 and then used by

the 'testdisk' and 'partclone' pacakges in Factory (but never SLE).  The

official reiserfsprogs are maintained by me upstream (handwavy, they

don't take much maintenance), and are available on kernel.org.

Libreiserfs hasn't been touched by its author since 2004 and has no

official location for download.  We have a copy cached.  Other distros

have a copy cached.  That's it.

Parted stopped using file system libraries for any file system in 2011

and the dependencies are obsolete.  I've filed submit requests for SLE

and the Base:System project to remove them.

Testdisk uses it to recover reiserfs file systems, but it's clear it

hasn't seen real usage or even testing.  The libreiserfs API to iterate

over file contents is restricted to blocks, which means that any file

tails would be skipped entirely.  Digging through the code, it also

shows that even if that functionality was to be used, it requires

patches be applied to libreiserfs which we are not applying.  It can't work.

Partclone uses the library to iterate over the block-in-use bitmap to

copy only the parts of the file system in use.  That's simple to switch

over to libreiserfscore but I'm not volunteering to do it.  Practically,

as these would be old file systems and on relatively small devices

compared to today's devices. Reiserfs has an official file system size

limit of 16 TB but a practical limit of 8 TB.  Outside of a very

specific customer request a long time ago, I've never seen anyone trying

to use it on devices that large.  It's also pretty unlikely that anyone

with file systems that old that they are using and don't want to migrate

are using Tumbleweed or, really, any recent release.  dd will work just

fine.

Both of these packages reference that libreiserfs is optional and give

no hint as to where to locate it.  Outside of our own enabling that

support, I doubt it's used anywhere.

So, we have a situation where we have a library that has been abandoned

by its author and two relatively simple dependencies for a file system

that may still be in use for very old file systems (which also means

relatively small file systems compared to today's device sizes), and for

very limited use cases.  In some cases those are broken as well.

Someone else is welcome to step up to maintain this library and keep

those packages working with reiserfs (and fix those bugs) and I'm happy

to turn it over, but the real question is: do we really need to keep

this functionality around?

So, my proposal is:

- Remove libreiserfs as a dependency for parted (already submitted, not

much to discuss here)

- Remove libreiserfs as a dependency for partclone and testdisk.

- Remove libreiserfs entirely.

Isn't this used by btrfs-progs to support reiserfs->btrfs conversions?

Do we care that would be broken going forward?

No.  libreiserfs was a separate implementation that was never officially

adopted as part of the reiserfs project.  btrfsprogs and a little over a

dozen other package use libreiserfscore0 from reiserfsprogs (our

'reiserfs' package) for reiserfs support.

-Jeff

-- 

Jeff Mahoney

Director, SUSE Labs Data & Performance