enter_chroot: when preparing chroot, mount devpts filesystem as well

enter_chroot: when preparing chroot, mount devpts filesystem as well

* This also adds reverse sort into the umount list, because of cascading mounts, so that /foo/anything is always before /foo, and as such is always unmounted first. If the list were not sorted, "mount point busy" errors might occur, depending on various conditions.

TEST=
 1) With a previously created chroot, I ran enter_chroot.sh, and got the correct prompt. After logging out of that prompt, everything else was correctly unmounted, without any error messages. When entering chroot twice from two different shells, everything was correctly unmounted after the last shell exited.
 2) Repeat 1 but with cleanly created chroot just for this purpose.
 3) In the chroot, make packages for one board (x86-generic) using build_packages
 4) The messages "openpty failed: 'out of pty devices'" whenever trying to emerge anything (or other commands looking up pts) have disappeared.

[sosa, 2010-06-10 20:15:04]

Can you add a TEST= stanza to the issue to indicate how you tested this change.

http://codereview.chromium.org/2714010/diff/1/2
File enter_chroot.sh (right):

http://codereview.chromium.org/2714010/diff/1/2#newcode216
enter_chroot.sh:216: # sort the list of mounts in reverse order, to ensure
umount of cascading mounts in proper order
> 80 chars

http://codereview.chromium.org/2714010/diff/1/2#newcode217
enter_chroot.sh:217: for i in $(mount | grep -F "on $MOUNTED_PATH/" | sort -r |
awk '{print $3}'); do
> 80 chars

[zbehan, 2010-06-10 21:28:36]

On 2010/06/10 20:15:04, sosa wrote:
> Can you add a TEST= stanza to the issue to indicate how you tested this
change.

Will do.

> http://codereview.chromium.org/2714010/diff/1/2#newcode216
> enter_chroot.sh:216: # sort the list of mounts in reverse order, to ensure
> umount of cascading mounts in proper order
> > 80 chars
> 
> http://codereview.chromium.org/2714010/diff/1/2#newcode217
> enter_chroot.sh:217: for i in $(mount | grep -F "on $MOUNTED_PATH/" | sort -r
|
> awk '{print $3}'); do
> > 80 chars

I'll fix the 80 character lines and re-upload.

[sosa, 2010-06-10 21:32:14]

lgtm with another nit and assumes you add a TEST stanza

http://codereview.chromium.org/2714010/diff/6001/7001
File enter_chroot.sh (right):

http://codereview.chromium.org/2714010/diff/6001/7001#newcode219
enter_chroot.sh:219: $(mount | grep -F "on $MOUNTED_PATH/" | sort -r | awk
'{print $3}'); do
One more space indent

[zbehan, 2010-06-10 23:44:20]

http://codereview.chromium.org/2714010/diff/6001/7001
File enter_chroot.sh (right):

http://codereview.chromium.org/2714010/diff/6001/7001#newcode219
enter_chroot.sh:219: $(mount | grep -F "on $MOUNTED_PATH/" | sort -r | awk
'{print $3}'); do
On 2010/06/10 21:32:15, sosa wrote:
> One more space indent

Done.

[sosa, 2010-06-10 23:48:19]

lgtm