Reiser4 DOS

Reiser4 DOS

[Michael Buesch]

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Hi,

I'm running linux-2.6.5 with latest reiser4 snapshot patch.
The following script makes my system completely
unresponsive in a short time.

#!/bin/sh
mount -treiser4 /dev/hdX /mnt/reiser4
cd /mnt/reiser4
while `/bin/true`; do
	cd metas
done

- -- 
Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]

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Re: Reiser4 DOS

[Rene Rebe]

Hi,

On: Sun, 2 May 2004 15:38:47 +0200,
    Michael Buesch <mbuesch@freenet.de> wrote:

> #!/bin/sh
> mount -treiser4 /dev/hdX /mnt/reiser4
> cd /mnt/reiser4
> while `/bin/true`; do
> 	cd metas
> done

Are you sure this does not happen on other filesystem? This loop
mainly creates process creation pressure and is more likely some
scheduler thing than Reiser4.

Maybe you can cure this using:

while : ; do
...

Sincerely yours,
  René Rebe
    - ROCK Linux stable release maintainer

--  
René Rebe - Europe/Germany/Berlin
  rene@rocklinux.org rene@rocklinux-consulting.de
http://www.rocklinux.org http://www.rocklinux-consulting.de

Re: Reiser4 DOS

[Michael Buesch]

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On Sunday 02 May 2004 15:54, you wrote:
> Are you sure this does not happen on other filesystem? This loop

No, I don't know another filesystem with some kind of these
meta-files and directories.

> mainly creates process creation pressure and is more likely some
> scheduler thing than Reiser4.
> 
> Maybe you can cure this using:
> 
> while : ; do
> ...

Same thing. Memory usage grows and grows until the
system is dead.

> 
> Sincerely yours,
>   René Rebe
>     - ROCK Linux stable release maintainer

- -- 
Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]


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Re: Reiser4 DOS

[mjt]

On Sun, May 02, 2004 at 03:38:47PM +0200, Michael Buesch wrote:
>
>#!/bin/sh
>mount -treiser4 /dev/hdX /mnt/reiser4
>cd /mnt/reiser4
>while `/bin/true`; do
>	cd metas
>done

Do I remember something of my own, or wasn't there some discussion about
this?

"Should meta files have meta files"

I'd say this is a bug, meta files seem like they shouldn't have meta
data, by definition.

Is this going away in the next snapshot?

What about the metas dir inheriting +x from it's parent DIRECTORY, and
not necessarily parent FILE?

-- 
mjt

Re: Reiser4 DOS

[Hans Reiser]

Markus Törnqvist wrote:

>On Sun, May 02, 2004 at 03:38:47PM +0200, Michael Buesch wrote:
>  
>
>>#!/bin/sh
>>mount -treiser4 /dev/hdX /mnt/reiser4
>>cd /mnt/reiser4
>>while `/bin/true`; do
>>	cd metas
>>done
>>    
>>
>
>Do I remember something of my own, or wasn't there some discussion about
>this?
>
>"Should meta files have meta files"
>
>I'd say this is a bug, meta files seem like they shouldn't have meta
>data, by definition.
>  
>
Nikita....

>Is this going away in the next snapshot?
>
>What about the metas dir inheriting +x from it's parent DIRECTORY, and
>not necessarily parent FILE?
>
>  
>

Re: Reiser4 DOS

[Nikita Danilov]

Michael Buesch writes:
 > -----BEGIN PGP SIGNED MESSAGE-----
 > Hash: SHA1
 > 
 > Hi,
 > 
 > I'm running linux-2.6.5 with latest reiser4 snapshot patch.
 > The following script makes my system completely
 > unresponsive in a short time.
 > 
 > #!/bin/sh
 > mount -treiser4 /dev/hdX /mnt/reiser4
 > cd /mnt/reiser4
 > while `/bin/true`; do
 > 	cd metas
 > done

One can DoS any Linux file-system by

$ while : ;do mkdir x && cd x ;done

Due to some shell peculiarities (like doing getcwd() on each cd), it may
be necessary to re-write this in C. Problem is less grave on SMP system,
but it's only matter of running enough instances of this in parallel. :)

Nikita.

 > 
 > - -- 
 > Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]
 > 
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Re: Reiser4 DOS

[Hans Reiser]

why does it work? Does it really work, or does it just make the machine 
heavily loaded?

Re: Reiser4 DOS

[Redeeman]

On Sun, 2004-05-02 at 15:38, Michael Buesch wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Hi,
> 
> I'm running linux-2.6.5 with latest reiser4 snapshot patch.
> The following script makes my system completely
> unresponsive in a short time.
> 
> #!/bin/sh
> mount -treiser4 /dev/hdX /mnt/reiser4
> cd /mnt/reiser4
> while `/bin/true`; do
> 	cd metas
> done
> 
i tried this, my system doesent lock in any form :) however, it does use
alot cpu, but still my system runs strong

> - -- 
> Regards Michael Buesch  [ http://www.tuxsoft.de.vu ]
> 
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> =6bBp
> -----END PGP SIGNATURE-----
-- 
Regards, Redeeman
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