Check losetup capabilities before specifying to mount as read-only.

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

diff --git a/scripts/live-helpers b/scripts/live-helpers
index 771ab85..20952f3 100644 (file)
--- a/scripts/live-helpers
+++ b/scripts/live-helpers
@@ -29,6 +29,20 @@ subdevices ()
        echo ${r}
 }
 
+is_supported_fs ()
+{
+       # FIXME: do something better like the scan of supported filesystems
+       fstype="${1}"
+
+       case ${fstype} in
+               vfat|iso9660|udf|ext2|ext3|ntfs|jffs2)
+               return 0
+               ;;
+       esac
+
+       return 1
+}
+
 get_fstype ()
 {
        local FSTYPE
@@ -153,6 +167,7 @@ setup_loop ()
        local pattern=${3}
        local offset=${4}
        local encryption=${5}
+       local readonly=${6}
 
        modprobe -q -b "${module}"
        udevsettle
@@ -164,6 +179,14 @@ setup_loop ()
                        dev=$(sys2dev "${loopdev}")
                        options=''
 
+                       if [ -n ${readonly} ]
+                       then
+                               if /sbin/losetup --help 2>&1 | grep -q -- "-r\b"
+                               then
+                                       options="${options} -r"
+                               fi
+                       fi
+
                        if [ 0 -lt "${offset}" ]
                        then
                                options="${options} -o ${offset}"
@@ -234,7 +257,7 @@ find_cow_device ()
        pers_label="${1}"
        cow_backing="/${pers_label}-backing"
 
-       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop)
+       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
        do
                for dev in $(subdevices "${sysblock}")
                do
@@ -244,20 +267,24 @@ find_cow_device ()
                        then
                                echo "${devname}"
                                return
-                       elif [ "$(get_fstype ${devname})" = "vfat" ]
-                       then
-                               # FIXME: all supported block devices should be scanned
-                               mkdir -p "${cow_backing}"
-                               try_mount "${devname}" "${cow_backing}" "rw"
-
-                               if [ -e "${cow_backing}/${pers_label}" ]
-                               then
-                                       echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*")
-                                       return 0
-                               else
-                                       umount ${cow_backing}
-                               fi
                        fi
+
+                       case "$(get_fstype ${devname})" in
+                               vfat|ext2|ext3|jffs2)
+                                       mkdir -p "${cow_backing}"
+                                       try_mount "${devname}" "${cow_backing}" "rw"
+
+                                       if [ -f "${cow_backing}/${pers_label}" ]
+                                       then
+                                               echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*")
+                                               return 0
+                                       else
+                                               umount ${cow_backing}
+                                       fi
+                                       ;;
+                               *)
+                                       ;;
+                       esac
                done
        done
 }
@@ -270,22 +297,21 @@ find_files ()
        filenames="${1}"
        snap_backing="/snap-backing"
 
-       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop)
+       for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram | grep -v fd)
        do
                for dev in $(subdevices "${sysblock}")
                do
                        devname=$(sys2dev "${dev}")
                        devfstype="$(get_fstype ${devname})"
 
-                       if [ "${devfstype}" = "vfat" ] ||  [ "${devfstype}" = "ext2" ] || [ "${devfstype}" = "ext3" ] || [ "${devfstype}" = "jffs2" ]
+                       if is_supported_fs ${devfstype}
                        then
-                               # FIXME: all supported block devices should be scanned
                                mkdir -p "${snap_backing}"
                                try_mount "${devname}" "${snap_backing}" "ro"
 
                                for filename in ${filenames}
-                               do
-                                       if [ -e "${snap_backing}/${filename}" ]
+                                       do
+                                       if [ -f "${snap_backing}/${filename}" ]
                                        then
                                                echo "${devname} ${snap_backing} ${filename}"
                                                return 0