def create(l, regnode, add_component, components):
assert(len(components) == 1)
origin = SnapshotOriginNode(l)
c = components[0]
# create a symlink so that SNAPSHOT module can find our underlying
# device later.
s = symlinknode.SymLinkNode(getSnapshotOriginOriginPath(origin.lvolid))
regnode(s)
add_component(s, c)
return origin
def do(self):
assert(len(self.components) > 0)
name = getSnapshotDevName(self.lvolid)
path = getDmDevPath(name)
if not os.path.exists(path):
origin_path = getSnapshotOriginOriginPath( \
self.snapshot_origin_lvolid)
origin_size = blockdev_getsize(origin_path)
c = self.components[0]
command = \
"echo 0 %s snapshot %s %s P %u | dmsetup create --readonly %s" \
% (origin_size, origin_path, c.path, SNAPSHOT_CHUNK_SIZE, name)
execute_retry_not_path_exist(command, path, DMSETUP_RETRY_TIMES)
self.path = path
