Re: ext4 inode tagging

On Thu, Jan 12, 2012 at 08:01:29PM +0100, [email protected] wrote:
> On 01/12/2012 03:13 AM, Herbert Poetzl wrote:
>> On Wed, Jan 11, 2012 at 07:31:09PM +0100, Roberto Puzzanghera wrote:
>>> Hello,

>>> I failed to tag my ext4 /vservers' partition and I found out
>>> that this is not yet supported for ext4.
>> hmm, what kernel/patch do you use?

> # vserver-info
> Versions:
>                    Kernel: 3.1.4-vs2.3.2.1-smp
>                    VS-API: 0x00020308
>                       VCI: 0x0000000013000f11
>              util-vserver: 0.30.216-pre3004; Dec  5 2011, 15:29:49

> Features:
>                        CC: gcc, gcc (GCC) 4.5.2
>                  CPPFLAGS: ''
>                    CFLAGS: '-g -O2 -std=c99 -Wall -pedantic -W 
> -funit-at-a-time'
>                build/host: 
> x86_64-unknown-linux-gnu/x86_64-unknown-linux-gnu
>              Use dietlibc: yes
>        Build C++ programs:
>        Build C99 programs: yes
>            Available APIs: v13,net,v21,v22,v23,netv2
>             ext2fs Source: e2fsprogs
>     syscall(2) invocation: alternative
>       vserver(2) syscall#: 236/glibc
>                crypto api: beecrypt
>           python bindings: no
>    use library versioning: yes

thanks!

>> it might not be working as expected as nobody I know
>> uses ext4 (too fragile and buggy) yet, but it should
>> definitely be supported/implemented in recent kernels

>>> As I have to decide to switch to ext3 or wait, is there any
>>> plan to implement this funcionality in the near future?
>> a good start would be to produce a test case which
>> goes wrong for you, so that we can look into it

>> best,
>> Herbert

> I'm following the howto on the wiki. The /vservers partition is
> mounted with "-o tag" as explained, but when I try to tag the
> guest's files I get the following error:

> # chxid -URx -c slacky /vservers/<vserver-name>/
> /vservers/<vserver-name>/<file-name>: Invalid argument
> ... and so on

> Of course, in case the linux-vserver team needs it, I would be
> glad to provide the access to my server for a test with ext4.

no, I don't think that will be necessary, but
could you run the following script on your system
and provide upload the output somewhere/

 # mkdir /test
 # testfs.sh -vvv -x -F ext4 -M /test -D <device>

note that <device> should be a partition, disk or
loopback device you do not mind to be reformatted
with ext4 (all data will be destroyed)

you can simply create one with:
 # dd if=/dev/zero of=/path/to/somewhere bs=1M count=1024
 # losetup /dev/loop0 /path/to/somewhere

also, no problem to use /mnt or /media/test instead
of just /test (i.e. it doesn't matter as long as
you specify the path in -M <path>)

the test script can be found here:
http://vserver.13thfloor.at/Stuff/SCRIPT/testfs.sh

thanks in advance,
Herbert

> Best regards
> Roberto Puzzanghera