Re: ReiserFS is not suitable for a root FS.

[Carl-Daniel Hailfinger <c-d.hailfinger.kernel.2003@gmx.net>]

Oleg Drokin wrote:
> Hello!
> 
> On Sat, May 17, 2003 at 02:01:00PM +0200, Carl-Daniel Hailfinger wrote:
> 
>>>>>With a ReiserFS file system you can't FSCK a file system that is mounted
>>>>>read-only.  This means that when a root file system needs to be FSCK'd
>>>>>you need to boot from installation media (or convert the swap space into
>>>>>a temporary root file system).
>>>>
>>>>I take this as a feature request. Right? It would certainly be nice to
>>>>have.
>>>
>>>Yes.
>>
>>Oleg? Given a statically linked reiserfsck binary completely loaded into
>>memory and an initrd below the reiserfs root filesystem, it should be
>>possible to completely unmount the root fs because the initrd is still
>>there and can serve as root fs.
>>In this situation, reiserfsck sould have no problems anymore because the
>>partition is not mounted at all.
>>
> 
> 
> Initrd is not always present, you know. And sticking 300k (dynamic) or 600k (static)
> reiserfsck in there is not all that fun probably.
> Our current idea is to check if fsck is going to repair the
> mounted partition and if this partition happens to contain the reiserfsck itself,
> then mlockall() is done to page in all the pages of executable
> (otherwise if we need to page something in in the middle of updating tree root pointer,
> we won't be able to find anythig and die) and then proceed as normal.

Any progress on this?

> This is still somewhat risky, though.
> And if fsck will die in the middle of repairing rootfs (which still can happen) (And say it was
> doing --rebuild-tree run), you won't be able to mount this fs anymore.


Regards,
Carl-Daniel