linux-kernel - Re: (un)mount ramfs from C code

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Message-ID: <C6DE73D6.12872%brian@visionpro.com>
Date:	Tue, 22 Sep 2009 12:30:14 -0700
From:	Brian McGrew <brian@...ionpro.com>
To:	Luciano Rocha <luciano@...otux.com>
CC:	<linux-kernel@...r.kernel.org>
Subject: Re: (un)mount ramfs from C code

> You mean without using system(3), right? System call is how your program
> interacts with the outside world.
> 
> The relevant system calls are:
>   - mount(2): mount("none", "/mnt", "ramfs", 0, NULL);
>   - umount(2): umount("/mnt");
> 

Thanks for the help!  I'm getting there.  Considering the following:

If (mount("ramfs", rd_path, "ramfs", MS_NOEXEC | MS_NOSUID, "size=2000m") <
0) {
    strerror(errno);
} else {
    std::cout << "mounted";
}

Works great!  Thank you.  However, even though the filesystem is mounted and
/bin/mountpoint confirms it's a mountpoint, I do not see the mountpoint
listed in /etc/mtab.

Also, according to what I've read about ramfs, the size is supposed to be
limited to size=, however, I can cat /dev/zero until the box it out of
memory (and swap).

I think I'm just missing something and google's not helping a whole lot
since ramfs isn't the most popular subject today.

Thanks,

-b

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