pungi/pungi/phases/createiso.py
Ken Dreyer 94ffa1c5c6 default "with_jigdo" to False
Fedora has not composed with jigdo in a long time. Disable it by
default.

Signed-off-by: Ken Dreyer <kdreyer@redhat.com>
Merges: https://pagure.io/pungi/pull-request/1561
Fixes: https://pagure.io/pungi/issue/1560
2021-11-04 13:37:51 +00:00

815 lines
29 KiB
Python

# -*- coding: utf-8 -*-
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Library General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <https://gnu.org/licenses/>.
import os
import random
import shutil
import stat
import json
import productmd.treeinfo
from productmd.images import Image
from kobo.threads import ThreadPool, WorkerThread
from kobo.shortcuts import run, relative_path
from six.moves import shlex_quote
from pungi.wrappers import iso
from pungi.wrappers.createrepo import CreaterepoWrapper
from pungi.wrappers import kojiwrapper
from pungi.phases.base import PhaseBase, PhaseLoggerMixin
from pungi.util import (
makedirs,
get_volid,
get_arch_variant_data,
failable,
get_file_size,
get_mtime,
read_json_file,
)
from pungi.media_split import MediaSplitter, convert_media_size
from pungi.compose_metadata.discinfo import read_discinfo, write_discinfo
from pungi.runroot import Runroot
from .. import createiso
class CreateisoPhase(PhaseLoggerMixin, PhaseBase):
name = "createiso"
def __init__(self, compose, buildinstall_phase):
super(CreateisoPhase, self).__init__(compose)
self.pool = ThreadPool(logger=self.logger)
self.bi = buildinstall_phase
def _find_rpms(self, path):
"""Check if there are some RPMs in the path."""
for _, _, files in os.walk(path):
for fn in files:
if fn.endswith(".rpm"):
return True
return False
def _is_bootable(self, variant, arch):
if arch == "src":
return False
if variant.type != "variant":
return False
skip = get_arch_variant_data(
self.compose.conf, "buildinstall_skip", arch, variant
)
if skip == [True]:
# Buildinstall is skipped for this tree. Can't create a bootable ISO.
return False
return bool(self.compose.conf.get("buildinstall_method", ""))
def _metadata_path(self, variant, arch, disc_num, disc_count):
return self.compose.paths.log.log_file(
arch,
"createiso-%s-%d-%d" % (variant.uid, disc_num, disc_count),
ext="json",
)
def save_reuse_metadata(self, cmd, variant, arch, opts):
"""Save metadata for future composes to verify if the compose can be reused."""
metadata = {
"cmd": cmd,
"opts": opts._asdict(),
}
metadata_path = self._metadata_path(
variant, arch, cmd["disc_num"], cmd["disc_count"]
)
with open(metadata_path, "w") as f:
json.dump(metadata, f, indent=2)
return metadata
def _load_old_metadata(self, cmd, variant, arch):
metadata_path = self._metadata_path(
variant, arch, cmd["disc_num"], cmd["disc_count"]
)
old_path = self.compose.paths.old_compose_path(metadata_path)
self.logger.info(
"Loading old metadata for %s.%s from: %s", variant, arch, old_path
)
try:
return read_json_file(old_path)
except Exception:
return None
def perform_reuse(self, cmd, variant, arch, opts, iso_path):
"""
Copy all related files from old compose to the new one. As a last step
add the new image to metadata.
"""
linker = OldFileLinker(self.logger)
old_file_name = os.path.basename(iso_path)
current_file_name = os.path.basename(cmd["iso_path"])
try:
# Hardlink ISO and manifest
for suffix in ("", ".manifest"):
linker.link(iso_path + suffix, cmd["iso_path"] + suffix)
# Copy log files
# The log file name includes filename of the image, so we need to
# find old file with the old name, and rename it to the new name.
log_file = self.compose.paths.log.log_file(
arch, "createiso-%s" % current_file_name
)
old_log_file = self.compose.paths.old_compose_path(
self.compose.paths.log.log_file(arch, "createiso-%s" % old_file_name)
)
linker.link(old_log_file, log_file)
# Copy jigdo files
if opts.jigdo_dir:
old_jigdo_dir = self.compose.paths.old_compose_path(opts.jigdo_dir)
for suffix in (".template", ".jigdo"):
linker.link(
os.path.join(old_jigdo_dir, old_file_name) + suffix,
os.path.join(opts.jigdo_dir, current_file_name) + suffix,
)
except Exception:
# A problem happened while linking some file, let's clean up
# everything.
linker.abort()
raise
# Add image to manifest
add_iso_to_metadata(
self.compose,
variant,
arch,
cmd["iso_path"],
bootable=cmd["bootable"],
disc_num=cmd["disc_num"],
disc_count=cmd["disc_count"],
)
def try_reuse(self, cmd, variant, arch, opts):
"""Try to reuse image from previous compose.
:returns bool: True if reuse was successful, False otherwise
"""
if not self.compose.conf["createiso_allow_reuse"]:
return
log_msg = "Cannot reuse ISO for %s.%s" % (variant, arch)
current_metadata = self.save_reuse_metadata(cmd, variant, arch, opts)
if opts.buildinstall_method and not self.bi.reused(variant, arch):
# If buildinstall phase was not reused for some reason, we can not
# reuse any bootable image. If a package change caused rebuild of
# boot.iso, we would catch it here too, but there could be a
# configuration change in lorax template which would remain
# undetected.
self.logger.info("%s - boot configuration changed", log_msg)
return False
# Check old compose configuration: extra_files and product_ids can be
# reflected on ISO.
old_config = self.compose.load_old_compose_config()
if not old_config:
self.logger.info("%s - no config for old compose", log_msg)
return False
# Convert current configuration to JSON and back to encode it similarly
# to the old one
config = json.loads(json.dumps(self.compose.conf))
for opt in self.compose.conf:
# Skip a selection of options: these affect what packages can be
# included, which we explicitly check later on.
config_whitelist = set(
[
"gather_lookaside_repos",
"pkgset_koji_builds",
"pkgset_koji_scratch_tasks",
"pkgset_koji_module_builds",
]
)
if opt in config_whitelist:
continue
if old_config.get(opt) != config.get(opt):
self.logger.info("%s - option %s differs", log_msg, opt)
return False
old_metadata = self._load_old_metadata(cmd, variant, arch)
if not old_metadata:
self.logger.info("%s - no old metadata found", log_msg)
return False
# Test if volume ID matches - volid can be generated dynamically based on
# other values, and could change even if nothing else is different.
if current_metadata["opts"]["volid"] != old_metadata["opts"]["volid"]:
self.logger.info("%s - volume ID differs", log_msg)
return False
# Compare packages on the ISO.
if compare_packages(
old_metadata["opts"]["graft_points"],
current_metadata["opts"]["graft_points"],
):
self.logger.info("%s - packages differ", log_msg)
return False
try:
self.perform_reuse(
cmd,
variant,
arch,
opts,
old_metadata["cmd"]["iso_path"],
)
return True
except Exception as exc:
self.compose.log_error(
"Error while reusing ISO for %s.%s: %s", variant, arch, exc
)
self.compose.traceback("createiso-reuse-%s-%s" % (variant, arch))
return False
def run(self):
symlink_isos_to = self.compose.conf.get("symlink_isos_to")
disc_type = self.compose.conf["disc_types"].get("dvd", "dvd")
deliverables = []
commands = []
for variant in self.compose.get_variants(
types=["variant", "layered-product", "optional"]
):
if variant.is_empty:
continue
for arch in variant.arches + ["src"]:
skip_iso = get_arch_variant_data(
self.compose.conf, "createiso_skip", arch, variant
)
if skip_iso == [True]:
self.logger.info(
"Skipping createiso for %s.%s due to config option"
% (variant, arch)
)
continue
volid = get_volid(self.compose, arch, variant, disc_type=disc_type)
os_tree = self.compose.paths.compose.os_tree(arch, variant)
iso_dir = self.compose.paths.compose.iso_dir(
arch, variant, symlink_to=symlink_isos_to
)
if not iso_dir:
continue
if not self._find_rpms(os_tree):
self.logger.warning(
"No RPMs found for %s.%s, skipping ISO" % (variant.uid, arch)
)
continue
bootable = self._is_bootable(variant, arch)
if bootable and not self.bi.succeeded(variant, arch):
self.logger.warning(
"ISO should be bootable, but buildinstall failed. "
"Skipping for %s.%s" % (variant, arch)
)
continue
split_iso_data = split_iso(
self.compose, arch, variant, no_split=bootable, logger=self.logger
)
disc_count = len(split_iso_data)
for disc_num, iso_data in enumerate(split_iso_data):
disc_num += 1
filename = self.compose.get_image_name(
arch, variant, disc_type=disc_type, disc_num=disc_num
)
iso_path = self.compose.paths.compose.iso_path(
arch, variant, filename, symlink_to=symlink_isos_to
)
if os.path.isfile(iso_path):
self.logger.warning(
"Skipping mkisofs, image already exists: %s", iso_path
)
continue
deliverables.append(iso_path)
graft_points = prepare_iso(
self.compose,
arch,
variant,
disc_num=disc_num,
disc_count=disc_count,
split_iso_data=iso_data,
)
cmd = {
"iso_path": iso_path,
"bootable": bootable,
"cmd": [],
"label": "", # currently not used
"disc_num": disc_num,
"disc_count": disc_count,
}
if os.path.islink(iso_dir):
cmd["mount"] = os.path.abspath(
os.path.join(os.path.dirname(iso_dir), os.readlink(iso_dir))
)
opts = createiso.CreateIsoOpts(
output_dir=iso_dir,
iso_name=filename,
volid=volid,
graft_points=graft_points,
arch=arch,
supported=self.compose.supported,
hfs_compat=self.compose.conf["iso_hfs_ppc64le_compatible"],
use_xorrisofs=self.compose.conf.get("createiso_use_xorrisofs"),
iso_level=self.compose.conf.get("iso_level"),
)
if bootable:
opts = opts._replace(
buildinstall_method=self.compose.conf["buildinstall_method"]
)
if self.compose.conf["create_jigdo"]:
jigdo_dir = self.compose.paths.compose.jigdo_dir(arch, variant)
opts = opts._replace(jigdo_dir=jigdo_dir, os_tree=os_tree)
# Try to reuse
if self.try_reuse(cmd, variant, arch, opts):
# Reuse was successful, go to next ISO
continue
script_file = os.path.join(
self.compose.paths.work.tmp_dir(arch, variant),
"createiso-%s.sh" % filename,
)
with open(script_file, "w") as f:
createiso.write_script(opts, f)
cmd["cmd"] = ["bash", script_file]
commands.append((cmd, variant, arch))
if self.compose.notifier:
self.compose.notifier.send("createiso-targets", deliverables=deliverables)
for (cmd, variant, arch) in commands:
self.pool.add(CreateIsoThread(self.pool))
self.pool.queue_put((self.compose, cmd, variant, arch))
self.pool.start()
def read_packages(graft_points):
"""Read packages that were listed in given graft points file.
Only files under Packages directory are considered. Particularly this
excludes .discinfo, .treeinfo and media.repo as well as repodata and
any extra files.
Extra files are easier to check by configuration (same name doesn't
imply same content). Repodata depend entirely on included packages (and
possibly product id certificate), but are affected by current time
which can change checksum despite data being the same.
"""
with open(graft_points) as f:
return set(line.split("=", 1)[0] for line in f if line.startswith("Packages/"))
def compare_packages(old_graft_points, new_graft_points):
"""Read packages from the two files and compare them."""
old_files = read_packages(old_graft_points)
new_files = read_packages(new_graft_points)
return old_files != new_files
class CreateIsoThread(WorkerThread):
def fail(self, compose, cmd, variant, arch):
self.pool.log_error("CreateISO failed, removing ISO: %s" % cmd["iso_path"])
try:
# remove incomplete ISO
os.unlink(cmd["iso_path"])
# TODO: remove jigdo & template
except OSError:
pass
if compose.notifier:
compose.notifier.send(
"createiso-imagefail",
file=cmd["iso_path"],
arch=arch,
variant=str(variant),
)
def process(self, item, num):
compose, cmd, variant, arch = item
can_fail = compose.can_fail(variant, arch, "iso")
with failable(
compose, can_fail, variant, arch, "iso", logger=self.pool._logger
):
self.worker(compose, cmd, variant, arch, num)
def worker(self, compose, cmd, variant, arch, num):
mounts = [compose.topdir]
if "mount" in cmd:
mounts.append(cmd["mount"])
bootable = cmd["bootable"]
log_file = compose.paths.log.log_file(
arch, "createiso-%s" % os.path.basename(cmd["iso_path"])
)
msg = "Creating ISO (arch: %s, variant: %s): %s" % (
arch,
variant,
os.path.basename(cmd["iso_path"]),
)
self.pool.log_info("[BEGIN] %s" % msg)
try:
run_createiso_command(
num, compose, bootable, arch, cmd["cmd"], mounts, log_file
)
except Exception:
self.fail(compose, cmd, variant, arch)
raise
add_iso_to_metadata(
compose,
variant,
arch,
cmd["iso_path"],
cmd["bootable"],
cmd["disc_num"],
cmd["disc_count"],
)
# Delete staging directory if present.
staging_dir = compose.paths.work.iso_staging_dir(
arch, variant, filename=os.path.basename(cmd["iso_path"]), create_dir=False
)
if os.path.exists(staging_dir):
try:
shutil.rmtree(staging_dir)
except Exception as e:
self.pool.log_warning(
"Failed to clean up staging dir: %s %s" % (staging_dir, str(e))
)
self.pool.log_info("[DONE ] %s" % msg)
if compose.notifier:
compose.notifier.send(
"createiso-imagedone",
file=cmd["iso_path"],
arch=arch,
variant=str(variant),
)
def add_iso_to_metadata(
compose,
variant,
arch,
iso_path,
bootable,
disc_num=1,
disc_count=1,
additional_variants=None,
):
img = Image(compose.im)
img.path = iso_path.replace(compose.paths.compose.topdir(), "").lstrip("/")
img.mtime = get_mtime(iso_path)
img.size = get_file_size(iso_path)
img.arch = arch
# XXX: HARDCODED
img.type = "dvd"
img.format = "iso"
img.disc_number = disc_num
img.disc_count = disc_count
img.bootable = bootable
img.subvariant = variant.uid
img.implant_md5 = iso.get_implanted_md5(iso_path, logger=compose._logger)
if additional_variants:
img.unified = True
img.additional_variants = additional_variants
setattr(img, "can_fail", compose.can_fail(variant, arch, "iso"))
setattr(img, "deliverable", "iso")
try:
img.volume_id = iso.get_volume_id(iso_path)
except RuntimeError:
pass
if arch == "src":
for variant_arch in variant.arches:
compose.im.add(variant.uid, variant_arch, img)
else:
compose.im.add(variant.uid, arch, img)
return img
def run_createiso_command(
num, compose, bootable, arch, cmd, mounts, log_file, with_jigdo=False
):
packages = [
"coreutils",
"xorriso" if compose.conf.get("createiso_use_xorrisofs") else "genisoimage",
"isomd5sum",
]
if with_jigdo and compose.conf["create_jigdo"]:
packages.append("jigdo")
if bootable:
extra_packages = {
"lorax": ["lorax", "which"],
"buildinstall": ["anaconda"],
}
packages.extend(extra_packages[compose.conf["buildinstall_method"]])
runroot = Runroot(compose, phase="createiso")
build_arch = arch
if runroot.runroot_method == "koji" and not bootable:
runroot_tag = compose.conf["runroot_tag"]
koji_wrapper = kojiwrapper.KojiWrapper(compose)
koji_proxy = koji_wrapper.koji_proxy
tag_info = koji_proxy.getTag(runroot_tag)
if not tag_info:
raise RuntimeError('Tag "%s" does not exist.' % runroot_tag)
tag_arches = tag_info["arches"].split(" ")
if "x86_64" in tag_arches:
# assign non-bootable images to x86_64 if possible
build_arch = "x86_64"
elif build_arch == "src":
# pick random arch from available runroot tag arches
build_arch = random.choice(tag_arches)
runroot.run(
cmd,
log_file=log_file,
arch=build_arch,
packages=packages,
mounts=mounts,
weight=compose.conf["runroot_weights"].get("createiso"),
)
def split_iso(compose, arch, variant, no_split=False, logger=None):
"""
Split contents of the os/ directory for given tree into chunks fitting on ISO.
All files from the directory are taken except for possible boot.iso image.
Files added in extra_files phase are put on all disks.
If `no_split` is set, we will pretend that the media is practically
infinite so that everything goes on single disc. A warning is printed if
the size is bigger than configured.
"""
if not logger:
logger = compose._logger
media_size = compose.conf["iso_size"]
media_reserve = compose.conf["split_iso_reserve"]
split_size = convert_media_size(media_size) - convert_media_size(media_reserve)
real_size = None if no_split else split_size
ms = MediaSplitter(real_size, compose, logger=logger)
os_tree = compose.paths.compose.os_tree(arch, variant)
extra_files_dir = compose.paths.work.extra_files_dir(arch, variant)
# scan extra files to mark them "sticky" -> they'll be on all media after split
extra_files = set(["media.repo"])
for root, dirs, files in os.walk(extra_files_dir):
for fn in files:
path = os.path.join(root, fn)
rel_path = relative_path(path, extra_files_dir.rstrip("/") + "/")
extra_files.add(rel_path)
packages = []
all_files = []
all_files_ignore = []
ti = productmd.treeinfo.TreeInfo()
ti.load(os.path.join(os_tree, ".treeinfo"))
boot_iso_rpath = ti.images.images.get(arch, {}).get("boot.iso", None)
if boot_iso_rpath:
all_files_ignore.append(boot_iso_rpath)
if all_files_ignore:
logger.debug("split_iso all_files_ignore = %s" % ", ".join(all_files_ignore))
for root, dirs, files in os.walk(os_tree):
for dn in dirs[:]:
repo_dir = os.path.join(root, dn)
if repo_dir == os.path.join(
compose.paths.compose.repository(arch, variant), "repodata"
):
dirs.remove(dn)
for fn in files:
path = os.path.join(root, fn)
rel_path = relative_path(path, os_tree.rstrip("/") + "/")
sticky = rel_path in extra_files
if rel_path in all_files_ignore:
logger.info("split_iso: Skipping %s" % rel_path)
continue
if root.startswith(compose.paths.compose.packages(arch, variant)):
packages.append((path, os.path.getsize(path), sticky))
else:
all_files.append((path, os.path.getsize(path), sticky))
for path, size, sticky in all_files + packages:
ms.add_file(path, size, sticky)
logger.debug("Splitting media for %s.%s:" % (variant.uid, arch))
result = ms.split()
if no_split and result[0]["size"] > split_size:
logger.warning(
"ISO for %s.%s does not fit on single media! It is %s bytes too big. "
"(Total size: %s B)"
% (variant.uid, arch, result[0]["size"] - split_size, result[0]["size"])
)
return result
def prepare_iso(
compose, arch, variant, disc_num=1, disc_count=None, split_iso_data=None
):
tree_dir = compose.paths.compose.os_tree(arch, variant)
filename = compose.get_image_name(arch, variant, disc_num=disc_num)
iso_dir = compose.paths.work.iso_dir(arch, filename)
# modify treeinfo
ti_path = os.path.join(tree_dir, ".treeinfo")
ti = load_and_tweak_treeinfo(ti_path, disc_num, disc_count)
copy_boot_images(tree_dir, iso_dir)
if disc_count > 1:
# remove repodata/repomd.xml from checksums, create a new one later
if "repodata/repomd.xml" in ti.checksums.checksums:
del ti.checksums.checksums["repodata/repomd.xml"]
# rebuild repodata
createrepo_c = compose.conf["createrepo_c"]
createrepo_checksum = compose.conf["createrepo_checksum"]
repo = CreaterepoWrapper(createrepo_c=createrepo_c)
file_list = "%s-file-list" % iso_dir
packages_dir = compose.paths.compose.packages(arch, variant)
file_list_content = []
for i in split_iso_data["files"]:
if not i.endswith(".rpm"):
continue
if not i.startswith(packages_dir):
continue
rel_path = relative_path(i, tree_dir.rstrip("/") + "/")
file_list_content.append(rel_path)
if file_list_content:
# write modified repodata only if there are packages available
run("cp -a %s/repodata %s/" % (shlex_quote(tree_dir), shlex_quote(iso_dir)))
with open(file_list, "w") as f:
f.write("\n".join(file_list_content))
cmd = repo.get_createrepo_cmd(
tree_dir,
update=True,
database=True,
skip_stat=True,
pkglist=file_list,
outputdir=iso_dir,
workers=compose.conf["createrepo_num_workers"],
checksum=createrepo_checksum,
)
run(cmd)
# add repodata/repomd.xml back to checksums
ti.checksums.add(
"repodata/repomd.xml", createrepo_checksum, root_dir=iso_dir
)
new_ti_path = os.path.join(iso_dir, ".treeinfo")
ti.dump(new_ti_path)
# modify discinfo
di_path = os.path.join(tree_dir, ".discinfo")
data = read_discinfo(di_path)
data["disc_numbers"] = [disc_num]
new_di_path = os.path.join(iso_dir, ".discinfo")
write_discinfo(new_di_path, **data)
if not disc_count or disc_count == 1:
data = iso.get_graft_points(compose.paths.compose.topdir(), [tree_dir, iso_dir])
else:
data = iso.get_graft_points(
compose.paths.compose.topdir(),
[iso._paths_from_list(tree_dir, split_iso_data["files"]), iso_dir],
)
if compose.conf["createiso_break_hardlinks"]:
compose.log_debug(
"Breaking hardlinks for ISO %s for %s.%s" % (filename, variant, arch)
)
break_hardlinks(
data, compose.paths.work.iso_staging_dir(arch, variant, filename)
)
# Create hardlinks for files with duplicate contents.
compose.log_debug(
"Creating hardlinks for ISO %s for %s.%s" % (filename, variant, arch)
)
create_hardlinks(
compose.paths.work.iso_staging_dir(arch, variant, filename),
log_file=compose.paths.log.log_file(
arch, "iso-hardlink-%s.log" % variant.uid
),
)
# TODO: /content /graft-points
gp = "%s-graft-points" % iso_dir
iso.write_graft_points(gp, data, exclude=["*/lost+found", "*/boot.iso"])
return gp
def load_and_tweak_treeinfo(ti_path, disc_num=1, disc_count=1):
"""Treeinfo on the media should not contain any reference to boot.iso and
it should also have a valid [media] section.
"""
ti = productmd.treeinfo.TreeInfo()
ti.load(ti_path)
ti.media.totaldiscs = disc_count or 1
ti.media.discnum = disc_num
# remove boot.iso from all sections
paths = set()
for platform in ti.images.images:
if "boot.iso" in ti.images.images[platform]:
paths.add(ti.images.images[platform].pop("boot.iso"))
# remove boot.iso from checksums
for i in paths:
if i in ti.checksums.checksums.keys():
del ti.checksums.checksums[i]
return ti
def copy_boot_images(src, dest):
"""When mkisofs is called it tries to modify isolinux/isolinux.bin and
images/boot.img. Therefore we need to make copies of them.
"""
for i in ("isolinux/isolinux.bin", "images/boot.img"):
src_path = os.path.join(src, i)
dst_path = os.path.join(dest, i)
if os.path.exists(src_path):
makedirs(os.path.dirname(dst_path))
shutil.copy2(src_path, dst_path)
def break_hardlinks(graft_points, staging_dir):
"""Iterate over graft points and copy any file that has more than 1
hardlink into the staging directory. Replace the entry in the dict.
"""
for f in graft_points:
info = os.stat(graft_points[f])
if stat.S_ISREG(info.st_mode) and info.st_nlink > 1:
dest_path = os.path.join(staging_dir, graft_points[f].lstrip("/"))
makedirs(os.path.dirname(dest_path))
shutil.copy2(graft_points[f], dest_path)
graft_points[f] = dest_path
def create_hardlinks(staging_dir, log_file):
"""Create hardlinks within the staging directory.
Should happen after break_hardlinks()
"""
cmd = ["/usr/sbin/hardlink", "-c", "-vv", staging_dir]
run(cmd, logfile=log_file, show_cmd=True)
class OldFileLinker(object):
"""
A wrapper around os.link that remembers which files were linked and can
clean them up.
"""
def __init__(self, logger):
self.logger = logger
self.linked_files = []
def link(self, src, dst):
self.logger.debug("Hardlinking %s to %s", src, dst)
os.link(src, dst)
self.linked_files.append(dst)
def abort(self):
"""Clean up all files created by this instance."""
for f in self.linked_files:
os.unlink(f)