linux-kernel - Re: v3.10: unmount won't work

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Message-ID: <51929A16.8050306@gmx.de>
Date:	Tue, 14 May 2013 22:09:58 +0200
From:	Toralf Förster <toralf.foerster@....de>
To:	linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org
CC:	Linux Kernel <linux-kernel@...r.kernel.org>
Subject: Re: v3.10: unmount won't work

On 05/14/2013 09:12 PM, Toralf Förster wrote:
> At a stable 32 bit stable Gentoo with kernel v3.10-rc1-113-ga2c7a54 I cannot umount an (EXT4) fs
> which was created in a file located in a tmpfs partition and loop mounted  :
> 
> That file system was used to hold victims files shared via NFSv4 to an user mode linux 
> on which trinity was used to fuzz testing a patched UML guest kernel.

FWIW the numbers are really wrong for /mnt/trinity

# df -m /mnt/trinity/
Filesystem     1M-blocks  Used Available Use% Mounted on
/dev/loop0        183851 31165    143325  18% /mnt/trinity

b/c 257 MB were specified for the file in which the EXT4FS was created:

# ls -lh /mnt/ramdisk/disk0
-rw-r--r-- 1 tfoerste users 257M May 14 20:56 /mnt/ramdisk/disk0

here is the corresponding code snippet :
	FS="ext4"
        dd if=/dev/zero of=/mnt/ramdisk/disk0 bs=1M count=257 2>/dev/null || return 2
        yes | /sbin/mkfs.$FS /mnt/ramdisk/disk0 1>/dev/null || return 3
        sudo su -c "mount -o loop /mnt/ramdisk/disk0 /mnt/trinity/; chmod 777 /mnt/trinity" || return 4

-- 
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3
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