[arch-releng] [RFC] [archiso] Add support for img_label= and allow img_dev same as cow_dev

[Gerardo Exequiel Pozzi]

* Support img_label=
* Allow use img_dev= as cow_device=
* Use new function _mnt_dev() from archiso.
* Check for error while setting loopback device.

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386 at yahoo.com.ar>
---
 README                         |    4 +++-
 archiso/hooks/archiso_loop_mnt |   35 +++++++++++++++++------------------
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/README b/README
index 55e84d8..a7c76a2 100644
--- a/README
+++ b/README
@@ -81,8 +81,10 @@ INDEX
 
 ** hooks/archiso_loop_mnt
 
-* img_dev=          Device where archiso-image.iso reside.
+* img_label=        Set the filesystem label where archiso-image.iso.
                     Default: (unset)
+* img_dev=          Device where archiso-image.iso reside.
+                    Default: (unset) or "/dev/disk/by-label/${img_label}"
 * img_loop=         Full path where archiso-image.iso is located on ${img_dev}
                     Default: (unset)
 
diff --git a/archiso/hooks/archiso_loop_mnt b/archiso/hooks/archiso_loop_mnt
index 18419e3..c1b25df 100644
--- a/archiso/hooks/archiso_loop_mnt
+++ b/archiso/hooks/archiso_loop_mnt
@@ -1,7 +1,8 @@
 # vim: set ft=sh:
 
 run_hook () {
-    if [ -n "${img_dev}" ] && [ -n "${img_loop}" ]; then
+    [[ -n "${img_label}" ]] && img_dev="/dev/disk/by-label/${img_label}"
+    if [[ -n "${img_dev}" && -n "${img_loop}" ]]; then
         mount_handler="archiso_loop_mount_handler"
     fi
 }
@@ -9,30 +10,28 @@ run_hook () {
 archiso_loop_mount_handler () {
     newroot="${1}"
 
-    msg ":: Waiting for boot device..."
-    while ! poll_device ${img_dev} 30; do
-        echo "ERROR: boot device didn't show up after 30 seconds..."
+    msg ":: Setup a loop device from ${img_loop} located at device ${img_dev}"
+    if [[ "${img_dev}" -ef "${cow_device}" ]]; then
+        _mnt_dev "${img_dev}" "/run/archiso/img_dev"
+    else
+        _mnt_dev "${img_dev}" "/run/archiso/img_dev" "-r"
+    fi
+
+    _dev_loop=$(losetup -f)
+    if ! losetup "${_dev_loop}" "/run/archiso/img_dev/${img_loop}"; then
+        echo "ERROR: Setting loopback device '${_dev_loop}'"
+        echo "   for file '/run/archiso/img_dev/${img_loop}'"
         echo "   Falling back to interactive prompt"
         echo "   You can try to fix the problem manually, log out when you are finished"
         launch_interactive_shell
-    done
-
-    msg "::: Setup a loop device from ${img_loop} located at device ${img_dev}"
-    FSTYPE=$(blkid -o value -s TYPE -p ${img_dev} 2> /dev/null)
-    if [ -n "${FSTYPE}" ]; then
-        mkdir -p /run/archiso/img_dev
-        if mount -r -t "${FSTYPE}" ${img_dev} /run/archiso/img_dev > /dev/null 2>&1; then
-            _dev_loop=$(losetup -f)
-            losetup ${_dev_loop} /run/archiso/img_dev/${img_loop}
-        fi
     fi
 
     archiso_mount_handler ${newroot}
 
-    if [ "${copytoram}" = "y" ]; then
-        msg "::: Deataching loop device ${_dev_loop}"
+    if [[ "${copytoram}" == "y" ]]; then
         losetup -d ${_dev_loop}
-        msg "::: Unmounting ${img_dev}"
-        umount ${img_dev}
+        umount /run/archiso/img_dev
+    else
+        echo ${_dev_loop} > /run/archiso/img_dev_loop
     fi
 }
-- 
1.7.6