Reordered persistence lookups and boundaries (Closes: #500672).

[live-boot-grml.git] / scripts / live

diff --git a/scripts/live b/scripts/live
index f9e4fe2..7e0b100 100755 (executable)
--- a/scripts/live
+++ b/scripts/live
@@ -855,7 +855,7 @@ do_snap_copy ()
                if [ -n "${fstype}" ]
                then
                        # Copying stuff...
-                       mount -t "${fstype}" -o ro,noatime "${fromdev}" "${tomount}" || log_warning_msg "Error in mount -t ${fstype} -o ro,noatime ${fromdev} ${tomount}"
+                       mount -o ro -t "${fstype}" "${fromdev}" "${tomount}" || log_warning_msg "Error in mount -t ${fstype} -o ro ${fromdev} ${tomount}"
                        cp -a "${tomount}"/* ${todir}
                        umount "${tomount}"
                else
@@ -877,15 +877,26 @@ do_snap_copy ()
        fi
 }
 
+find_snap ()
+{
+       # Look for ${snap_label}.* in block devices
+       snap_label="${1}"
+       snapdata=$(find_files "${snap_label}.squashfs ${snap_label}.cpio.gz ${snap_label}.ext2 ${snap_label}.ext3 ${snap_label}.jffs2")
+       if [ -z "${snapdata}" ]
+       then
+               snapdata=$(find_cow_device "${snap_label}")
+       fi
+       echo "${snapdata}"
+}
+
 try_snap ()
 {
-       # Look for ${snap_label}.* in block devices and copy the contents to ${snap_mount}
+        # copy the contents of previously found snapshot to ${snap_mount}
        # and remember the device and filename for resync on exit in live-initramfs.init
 
-       snap_label="${1}"
+       snapdata="${1}"
        snap_mount="${2}"
        snap_type="${3}"
-       snapdata=$(find_files "${snap_label}.squashfs ${snap_label}.cpio.gz ${snap_label}.ext2 ${snap_label}.ext3 ${snap_label}.jffs2")
 
        if [ ! -z "${snapdata}" ]
        then
@@ -895,6 +906,10 @@ try_snap ()
                snapfile="$(echo ${snapdata} | cut -f3 -d ' ')"
 
                RES=""
+               if ! try_mount "${snapdev}" "${snapback}" "ro"
+               then
+                       break
+               fi
 
                if echo "${snapfile}" | grep -qs '\(squashfs\|ext2\|ext3\|jffs2\)'
                then
@@ -922,38 +937,36 @@ try_snap ()
                        log_warning_msg "Impossible to include the ${snapfile} Snapshot file"
                fi
 
-       else
-               # Try to find if it could be a snapshot partition
-               dev=$(find_cow_device "${snap_label}")
 
-               if [ -b "${dev}" ]
+       elif [ -b "${snapdata}" ]
+       then
+               # Try to find if it could be a snapshot partition
+               dev="${snapdata}"
+               log_success_msg "found snapshot device on ${dev}"
+               if echo "${dev}" | grep -qs loop
                then
-                       log_success_msg "found snapshot device on ${dev}"
-                       if echo "${dev}" | grep -qs loop
-                       then
-                               # strange things happens, user confused?
-                               snaploop=$( losetup ${dev} | awk '{print $3}' | tr -d '()' )
-                               snapfile=$(basename ${snaploop})
-                               snapdev=$(cat /proc/mounts | awk '{print $2,$1}' | grep -es "^$( dirname ${snaploop} )" | cut -f2 -d ' ')
-                       else
-                               snapdev="${dev}"
-                       fi
+                       # strange things happens, user confused?
+                       snaploop=$( losetup ${dev} | awk '{print $3}' | tr -d '()' )
+                       snapfile=$(basename ${snaploop})
+                       snapdev=$(cat /proc/mounts | awk '{print $2,$1}' | grep -es "^$( dirname ${snaploop} )" | cut -f2 -d ' ')
+               else
+                       snapdev="${dev}"
+               fi
 
-                       if ! do_snap_copy "${dev}" "${snap_mount}" "${snap_type}"
+               if ! do_snap_copy "${dev}" "${snap_mount}" "${snap_type}"
+               then
+                       log_warning_msg "Impossible to include the ${snap_type} Snapshot"
+                       return 1
+               else
+                       if [ -n "${snapfile}" ]
                        then
-                               log_warning_msg "Impossible to include the ${snap_label} Snapshot"
-                               return 1
-                       else
-                               if [ -n "${snapfile}" ]
-                               then
-                                       # it was a loop device, user confused
-                                       umount ${snapdev}
-                               fi
+                               # it was a loop device, user confused
+                               umount ${snapdev}
                        fi
-               else
-                       log_warning_msg "Impossible to include the ${snap_label} Snapshot"
-                       return 1
                fi
+       else
+               log_warning_msg "Impossible to include the ${snap_type} Snapshot"
+               return 1
        fi
 
        echo "export ${snap_type}SNAP="${snap_mount}":${snapdev}:${snapfile}" >> /etc/live.conf # for resync on reboot/halt
@@ -1114,7 +1127,21 @@ setup_unionfs ()
                        fi
                done
 
+               # search for label and files (this could be hugely optimized)
                cowprobe=$(find_cow_device "${root_persistence}")
+               if [ -b "${cowprobe}" ]
+               then
+                       # Blacklist /cow device, to avoid inconsistent setups for overlapping snapshots
+                       # makes sense to have both persistence for /cow and /home mounted, maybe also with
+                       # snapshots to be sure to really store some e.g key config files,
+                       # but not on the same media
+                       blacklistdev="${cowprobe}"
+               fi
+               # homecow just mount something on /home, this should be generalized some way
+               homecow=$(find_cow_device "${home_persistence}" "${blacklistdev}")
+               root_snapdata=$(find_snap "${root_snapshot_label}" "${blacklistdev}")
+               # This second type should be removed when snapshot grow smarter
+               home_snapdata=$(find_snap "${home_snapshot_label}" "${blacklistdev}")
 
                if [ -b "${cowprobe}" ]
                then
@@ -1203,7 +1230,6 @@ setup_unionfs ()
        then
                # directly mount /home
                # FIXME: add a custom mounts configurable system
-               homecow=$(find_cow_device "${home_persistence}" )
 
                if [ -b "${homecow}" ]
                then
@@ -1214,8 +1240,9 @@ setup_unionfs ()
                fi
 
                # Look for other snapshots to copy in
-               try_snap "${root_snapshot_label}" "${rootmnt}" "ROOT"
-               try_snap "${home_snapshot_label}" "${rootmnt}/home" "HOME"
+               try_snap "${root_snapdata}" "${rootmnt}" "ROOT"
+               # This second type should be removed when snapshot grow smarter
+               try_snap "${home_snapdata}" "${rootmnt}/home" "HOME"
        fi
 
        if [ -n "${SHOWMOUNTS}" ]