[archiso] Change cowfile_size= behavior

Move from percent to explicit size and set a default of 256M (sparse)

Signed-off-by: Gerardo Exequiel Pozzi <vmlinuz386@gmail.com>
This commit is contained in:
Gerardo Exequiel Pozzi 2014-10-12 21:03:52 -03:00
parent ccbeb35a7f
commit edfdd37ba0
3 changed files with 13 additions and 21 deletions

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@ -11,19 +11,13 @@ _mnt_fs() {
ro_dev=$(losetup --find --show --read-only "${img}")
echo ${ro_dev} >> /run/archiso/used_block_devices
ro_dev_size=$(blockdev --getsz ${ro_dev})
if [[ "${cowfile_size}" == "100" ]]; then
rw_dev_size=${ro_dev_size}
else
# size calculation done in this way to avoid integer overflow when ro_dev_size is > 10.2G
rw_dev_size=$((ro_dev_size/100*cowfile_size))
fi
if [[ "${cow_persistent}" == "P" ]]; then
if [[ -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
msg ":: Found '/run/archiso/cowspace/${cow_directory}/${img_name}.cow', using as persistent."
else
msg ":: Creating '/run/archiso/cowspace/${cow_directory}/${img_name}.cow' as persistent."
dd of="/run/archiso/cowspace/${cow_directory}/${img_name}.cow" count=0 seek=${rw_dev_size} &> /dev/null
truncate -s "${cowfile_size}" "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
fi
else
if [[ -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
@ -31,13 +25,13 @@ _mnt_fs() {
rm -f "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
fi
msg ":: Creating '/run/archiso/cowspace/${cow_directory}/${img_name}.cow' as non-persistent."
dd of="/run/archiso/cowspace/${cow_directory}/${img_name}.cow" count=0 seek=${rw_dev_size} &> /dev/null
truncate -s "${cowfile_size}" "/run/archiso/cowspace/${cow_directory}/${img_name}.cow"
fi
rw_dev=$(losetup --find --show "/run/archiso/cowspace/${cow_directory}/${img_name}.cow")
echo ${rw_dev} >> /run/archiso/used_block_devices
echo "0 ${ro_dev_size} snapshot ${ro_dev} ${rw_dev} ${cow_persistent} 8" | dmsetup create ${dm_snap_name}
dmsetup create ${dm_snap_name} --table "0 ${ro_dev_size} snapshot ${ro_dev} ${rw_dev} ${cow_persistent} 8"
_mnt_dev "/dev/mapper/${dm_snap_name}" "${newroot}${mnt}" "-w"
echo $(readlink -f /dev/mapper/${dm_snap_name}) >> /run/archiso/used_block_devices
@ -108,9 +102,7 @@ run_hook() {
[[ -z "${dm_snap_prefix}" ]] && dm_snap_prefix="arch"
[[ -z "${archisodevice}" ]] && archisodevice="/dev/disk/by-label/${archisolabel}"
if [[ -z "${cowfile_size}" ]]; then
cowfile_size="100"
else
cowfile_size=${cowfile_size/%}
cowfile_size="256M"
fi
if [[ -n "${cow_label}" ]]; then

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@ -12,6 +12,7 @@ build() {
add_binary dmsetup
add_binary losetup
add_binary mountpoint
add_binary truncate
add_file /usr/lib/udev/rules.d/60-cdrom_id.rules
add_file /usr/lib/udev/rules.d/10-dm.rules

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@ -31,27 +31,26 @@ INDEX
and continue booting if ok.
Default: (unset)
* cow_label= Set the filesystem label where COW (dm-snapshot)
files must be stored.
file must be stored.
Default: (unset)
* cow_device= Set the device node where COW (dm-snapshot) files
* cow_device= Set the device node where COW (dm-snapshot) file
must be stored.
Default: (unset) or "/dev/disk/by-label/${cow_label}"
* cow_directory= Set a directory inside ${cow_device}.
Default: "/persistent_${archisolabel}/${arch}"
* cow_persistent= Set if snapshots are persistent "P" or non-persistent "N".
* cow_persistent= Set if snapshot is persistent "P" or non-persistent "N".
Default: "N" (if no ${cow_device} is used) otherwise "P".
* cowspace_size= Set the size of tmpfs /cowspace. This space is used for
Copy-On-Write files of dm-snapshot.
Size is in bytes (suffix with "k", "m" and "g") or
in percentage of available RAM.
Default: "75%"
* cowfile_size= Set the size for all files to be used as COW (dm-snapshot),
in percentage of the ro-device.fs file. This is mostly useful
when cow_device= is used and filesystem does not support
sparse files (ie VFAT).
Default: "100%"
* cowfile_size= Set the size for COW file (dm-snapshot).
The argument is an integer and optional unit.
Units are M,G (powers of 1024) or MB,GB (powers of 1000).
Default: "256M"
* copytoram_size= Set the size of tmpfs. This space is used for
copy of all SquashFS images used, if copytoram=y.
airootfs.sfs image if copytoram=y.
Size is in bytes (suffix with "k", "m" and "g") or
in percentage of available RAM.
Default: "75%"