remove second call to free up loop device

remove second call to free up loop device

Change-Id: Ibf52597f01b7868f8472d2042e4d335442b82597

TEST=manually build a dev recovery image and verified no loop device warning
was outputted by losetup call

[Tan Gao, 2010-09-24 01:40:02]

Hi Will,

This CL fixes one more error in the clean-up part of
mod_image_for_dev_recovery.sh. In short, when we unmount a mount point for a
loop device, the loop device is freed as part of the unmount action. Hence,
there's no need to explicitly free the same loop device a second time :-(

Since adlr is OOO, you get the honor of approval :-)

PTAL thx!
Tan

[Will Drewry, 2010-09-29 22:19:02]

http://codereview.chromium.org/3439024/diff/3001/4001
File mod_image_for_dev_recovery.sh (right):

http://codereview.chromium.org/3439024/diff/3001/4001#newcode78
mod_image_for_dev_recovery.sh:78: mount | grep -q " on ${mnt_pt}" && sudo umount
${mnt_pt}
does this need to be umount -d, or is it implicit?

[Tan Gao, 2010-09-30 16:55:50]

Thanks for the review!

http://codereview.chromium.org/3439024/diff/3001/4001
File mod_image_for_dev_recovery.sh (right):

http://codereview.chromium.org/3439024/diff/3001/4001#newcode78
mod_image_for_dev_recovery.sh:78: mount | grep -q " on ${mnt_pt}" && sudo umount
${mnt_pt}
it's implicit. Quoting the man page

"The umount command will free the loop device (if any) associated with the
mount, in case it finds the option 'loop=...' in /etc/mtab, or when the -d
option was given."

[Will Drewry, 2010-09-30 17:37:50]

LGTM

[sosa, 2010-10-01 00:08:23]

I have a very strong suspicion this is incorrect.  Please see 
http://groups.google.com/a/chromium.org/group/chromium-os-dev/browse_thread/t...

I've started noticing we're losing loopback devices again.

[Will Drewry, 2010-10-01 00:59:04]

Hrm  - perhaps it is because the mtab is out of whack, default
behavior doesn't happen. boo.


On Thu, Sep 30, 2010 at 7:08 PM,  <sosa@chromium.org> wrote:
> I have a very strong suspicion this is incorrect.  Please see
>
http://groups.google.com/a/chromium.org/group/chromium-os-dev/browse_thread/t...
>
> I've started noticing we're losing loopback devices again.
>
> http://codereview.chromium.org/3439024/show
>