# How can I know what is using a specific module?

## houqp

Hi all,

I am currently playing with a kernel module but find myself cannot successfully remove it:

```
gentoo-tpm tmp # rmmod cipherflt

ERROR: Module cipherflt is in use
```

I tried the command lsmod:

```
gentoo-tpm tmp # lsmod |grep cipherflt

cipherflt              11705  1 

redirfs                42644  1 cipherflt,[permanent]
```

It only tell me that there is something using that cipherflt module, but I cannot find out what is that. So I cannot use rmmod to remove cipherflt.

Are there other tools that I can use to get more information about the loaded module?

Thanks

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## roarinelk

it's all here:  cipherflt is used by redirfs (which cannot be unloaded, hence "permanent" marker)

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## Veldrin

actually it is the other way around...

cipherflt depends on redirfs - which cannot be removed. 

as for the original question - i do not know.

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## roarinelk

Judging from the name and what I read about RedirFS,  cipherflt seems to be a

crypto "filter" module for redirfs.   Do you have any volumes encrypted without

LVM/LUKS/other std. kernel infrastructure?

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## houqp

 *roarinelk wrote:*   

> Judging from the name and what I read about RedirFS,  cipherflt seems to be a
> 
> crypto "filter" module for redirfs.   Do you have any volumes encrypted without
> 
> LVM/LUKS/other std. kernel infrastructure?

 

Yes, you are right. I actually, I don't have any volumes encrypted. I just apply the filter to a specific directory.

Thanks,

Houqp

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## houqp

 *Veldrin wrote:*   

> actually it is the other way around...
> 
> cipherflt depends on redirfs - which cannot be removed. 
> 
> 

 

I see, so the problem is redirfs. I suspect it is also used by redirfs .

Regards,

Houqp

----------

