2010-02-06 03:39:13

by Bai Shuwei

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Subject: device-mapper: remove ioctl failed: device or resource busy

Hi, All:
I port the xts-aes algorithm to FPGA board and use it to
encrypt/decrypt the disc. i will get the bellow information

But when excute the bellow commands
cryptsetup luksFormat -c aes-xts-plain -s 256 /dev/loop0
or
cryptsetup luksOpen /dev/loop0 test0

I get the bellow information
....
device-mapper: remove ioctl failed: device or resource busy
....

But others are all fine! I can format and mount test0. So i want to
know why the message is printed? Thanks!

Best REgards


Bai Shuwei

--
Love other people, as same as love yourself!
Don't think all the time, do it by your hands!

E-Mail: [email protected]


2010-02-06 20:13:16

by Milan Broz

[permalink] [raw]
Subject: Re: device-mapper: remove ioctl failed: device or resource busy

On 02/06/2010 04:32 AM, Bai Shuwei wrote:
> I port the xts-aes algorithm to FPGA board and use it to
> encrypt/decrypt the disc. i will get the bellow information
>
> But when excute the bellow commands
> cryptsetup luksFormat -c aes-xts-plain -s 256 /dev/loop0
> or
> cryptsetup luksOpen /dev/loop0 test0
>
> I get the bellow information
> ....
> device-mapper: remove ioctl failed: device or resource busy


Probably some udev rule triggers scan on temporary keyslot device.
This is known problem with some badly written udev rules and old versions
of DevKit-disks (recent version should not touch these internal devices at all).

Use cryptsetup 1.1.0 and run it with --debug to get more info, also see syslog (there
will be exact information which device was busy, I expect temp-cryptsetup*...)
(It will retry after 1 sec anyway, so it usually works - see that debug log.)

This is not kernel problem at all, just userspace race between some asynchronous
device scan triggered from udev (usually blkid check) and cryptsetup.

Milan