The overriding feature can be turned on/used by prefixing the file
system type to the path, separated from the device node with a colon.
Example (good override): ext4:/dev/vda49/path/to/grml.iso
If the file system specification contains any non-alphanumerical
characters other than '-' or '_', it will be treated as part of the
actual path, since, at least currently, all known file systems match
this rule.
Example (no override): cra$$$yf§:/dev/sr0/another_path/to/grml.iso
In the former example, no file system type override is detected, which
means that the code will eventually search for a device called
'cra$$$yf§:/dev/sr0' (which, granted, doesn't make a lot of sense).
Sometimes it's necessary or at least handy to specify the file system
used for mounting the fromiso backing device directly.
For instance, putting the ISO file on a RAID1-backed device will fail to
mount it through autodetection (which, really, in most cases is a good
thing to not corrupt the array).
This change also mounts the backing device read-only, which should
enable safe usage and mounting even on RAID1 devices. Note, though, that
read-only mounts are not really very much "read-only", since they
actually sometimes still change on-disk file system metadata, like the
last time the device was mounted).
This said, it should be safe enough and users can easily re-sync the
array to ensure consistency later on.
# support for fromiso=.../isofrom=....
if [ -n "$FROMISO" ]
then
# support for fromiso=.../isofrom=....
if [ -n "$FROMISO" ]
then
- ISO_DEVICE=$(dirname $FROMISO)
+ fs_type="${FROMISO%%:*}"
+ fs_type_auto='1'
+ ISO_DEVICE="${FROMISO}"
+ if echo "${fs_type}" | grep -q '[^[:alnum:]_-]'; then
+ # Not a valid file system name. Treat as part of the
+ # path, and, especially, use autodetection.
+ fs_type=''
+ else
+ # Looks like a file system specification, treat it
+ # like that.
+ fs_type_auto='0'
+ ISO_DEVICE="${ISO_DEVICE#*:}"
+ fi
+ ISO_DEVICE=$(dirname "${ISO_DEVICE}")
if ! [ -b $ISO_DEVICE ]
then
# to support unusual device names like /dev/cciss/c0d0p1
if ! [ -b $ISO_DEVICE ]
then
# to support unusual device names like /dev/cciss/c0d0p1
# example an ISO when booting on an ONIE system
if echo "${FROMISO}" | grep -q "\.iso$"
then
# example an ISO when booting on an ONIE system
if echo "${FROMISO}" | grep -q "\.iso$"
then
- fs_type=$(get_fstype "${FROMISO}")
+ if [ '0' -ne "${fs_type_auto}" ]; then
+ # Autodetect fs type if not overridden.
+ fs_type=$(get_fstype "${FROMISO}")
+ fi
if is_supported_fs ${fs_type}
then
mkdir /run/live/fromiso
if is_supported_fs ${fs_type}
then
mkdir /run/live/fromiso
- mount -t $fs_type "${FROMISO}" /run/live/fromiso
+ mount -t "${fs_type}" -o 'ro' "${FROMISO}" '/run/live/fromiso'
- echo "Warning: unable to mount ${FROMISO}." >>/boot.log
+ echo "Warning: unable to mount ${FROMISO} (type ${fs_type})." >>/boot.log
fi
devname="/run/live/fromiso"
fi
fi
devname="/run/live/fromiso"
fi
echo "Warning: device for bootoption fromiso= ($FROMISO) not found.">>/boot.log
fi
else
echo "Warning: device for bootoption fromiso= ($FROMISO) not found.">>/boot.log
fi
else
- fs_type=$(get_fstype "${ISO_DEVICE}")
+ # Need to extract actual ISO file path later on,
+ # initialize first.
+ iso_name="${FROMISO}"
+
+ if [ '0' -ne "${fs_type_auto}" ]; then
+ # Try to auto-detect file system if not
+ # explicitly provided.
+ fs_type=$(get_fstype "${ISO_DEVICE}")
+ else
+ # Delete file system type override.
+ iso_name="${iso_name#*:}"
+ fi
+ # At this point, the backing device should always be
+ # at the very front, so remove that - leaving only the
+ # ISO file path.
+ iso_name="$(echo "${iso_name}" | sed "s|^${ISO_DEVICE}||")"
if is_supported_fs ${fs_type}
then
mkdir /run/live/fromiso
if is_supported_fs ${fs_type}
then
mkdir /run/live/fromiso
- mount -t $fs_type "$ISO_DEVICE" /run/live/fromiso
- ISO_NAME="$(echo $FROMISO | sed "s|$ISO_DEVICE||")"
- loopdevname=$(setup_loop "/run/live/fromiso/${ISO_NAME}" "loop" "/sys/block/loop*" "" '')
+ mount -t "${fs_type}" -o 'ro' "$ISO_DEVICE" '/run/live/fromiso'
+ loopdevname=$(setup_loop "/run/live/fromiso/${iso_name}" "loop" "/sys/block/loop*" "" '')
devname="${loopdevname}"
else
devname="${loopdevname}"
else
- echo "Warning: unable to mount $ISO_DEVICE." >>/boot.log
+ echo "Warning: unable to mount $ISO_DEVICE (type ${fs_type})." >>/boot.log