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From: Sven Eisenberg <sven.eisenberg@novero.com>
Subject: Re: Data not freed after remove?
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Hi Richard and all

On 01.06.2016 13:55, Richard Weinberger wrote:
> ...
> What is the return code of mount()?
>
> > Is there any reason/bug known that would cause this behavior?
>
> Hmm, I don't know.
>
> > I know this can happen, when there i an open filedescriptor to the file.
> > So i verified and this is not the case for me.
>
> Yes, remount can fail if the volume is busy. That's why i wonder what
> the return code is.

Yes the volume is busy:
mount -o remount,ro /mnt/point  = -1 EBUSY (Device or resource busy)

I could not yet identify why it is in busy state.

I added some code to check for open file descriptors. I built a test
application which simulates the sequence. But it runs without a problem.
Can i get informations from the kernel, what file or state causes the
busy state?

br, Sven Eisenberg