Do not return /dev/loop-control in unused_loop_device

The function unused_loop_device in /usr/libexec/zfs/common.sh
returns /dev/loop-control on the first call. This device is NOT
a loop device (https://github.com/torvalds/linux/commit/770fe30)
it is a control device. This in turn causes the script zconfig.sh
to fail with:

  zpool-create.sh: Error 1 creating /tmp/zpool-vdev0 ->
  /dev/loop-control loopback

The patch makes the function return /dev/loop[0-9]* which are
loop devices.

Signed-off-by: Andrew Reid <ColdCanuck@nailedtotheperch.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #797

diff --git a/scripts/common.sh.in b/scripts/common.sh.in
index 0e792db..3c11820 100644 (file)
--- a/scripts/common.sh.in
+++ b/scripts/common.sh.in
@@ -263,7 +263,7 @@ check_loop_utils() {
 # Find and return an unused loopback device.
 #
 unused_loop_device() {
-       for DEVICE in `ls -1 /dev/loop* 2>/dev/null`; do
+       for DEVICE in `ls -1 /dev/loop[0-9]* 2>/dev/null`; do
                ${LOSETUP} ${DEVICE} &>/dev/null
                if [ $? -ne 0 ]; then
                        echo ${DEVICE}