Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1249 insertions, 0 deletions

diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c
new file mode 100644
index 0000000..af06ab2
--- /dev/null
+++ b/src/shared/machine-image.c
@@ -0,0 +1,1249 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/file.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <linux/fs.h>
+
+#include "alloc-util.h"
+#include "btrfs-util.h"
+#include "chattr-util.h"
+#include "copy.h"
+#include "dirent-util.h"
+#include "dissect-image.h"
+#include "env-file.h"
+#include "env-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "hostname-util.h"
+#include "id128-util.h"
+#include "lockfile-util.h"
+#include "log.h"
+#include "loop-util.h"
+#include "machine-image.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "os-util.h"
+#include "path-util.h"
+#include "rm-rf.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+#include "utf8.h"
+#include "util.h"
+#include "xattr-util.h"
+
+static const char* const image_search_path[_IMAGE_CLASS_MAX] = {
+        [IMAGE_MACHINE] =  "/etc/machines\0"              /* only place symlinks here */
+                           "/run/machines\0"              /* and here too */
+                           "/var/lib/machines\0"          /* the main place for images */
+                           "/var/lib/container\0"         /* legacy */
+                           "/usr/local/lib/machines\0"
+                           "/usr/lib/machines\0",
+
+        [IMAGE_PORTABLE] = "/etc/portables\0"             /* only place symlinks here */
+                           "/run/portables\0"             /* and here too */
+                           "/var/lib/portables\0"         /* the main place for images */
+                           "/usr/local/lib/portables\0"
+                           "/usr/lib/portables\0",
+};
+
+static Image *image_free(Image *i) {
+        assert(i);
+
+        free(i->name);
+        free(i->path);
+
+        free(i->hostname);
+        strv_free(i->machine_info);
+        strv_free(i->os_release);
+
+        return mfree(i);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(Image, image, image_free);
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(image_hash_ops, char, string_hash_func, string_compare_func,
+                                      Image, image_unref);
+
+static char **image_settings_path(Image *image) {
+        _cleanup_strv_free_ char **l = NULL;
+        const char *fn, *s;
+        unsigned i = 0;
+
+        assert(image);
+
+        l = new0(char*, 4);
+        if (!l)
+                return NULL;
+
+        fn = strjoina(image->name, ".nspawn");
+
+        FOREACH_STRING(s, "/etc/systemd/nspawn/", "/run/systemd/nspawn/") {
+                l[i] = strappend(s, fn);
+                if (!l[i])
+                        return NULL;
+
+                i++;
+        }
+
+        l[i] = file_in_same_dir(image->path, fn);
+        if (!l[i])
+                return NULL;
+
+        return TAKE_PTR(l);
+}
+
+static char *image_roothash_path(Image *image) {
+        const char *fn;
+
+        assert(image);
+
+        fn = strjoina(image->name, ".roothash");
+
+        return file_in_same_dir(image->path, fn);
+}
+
+static int image_new(
+                ImageType t,
+                const char *pretty,
+                const char *path,
+                const char *filename,
+                bool read_only,
+                usec_t crtime,
+                usec_t mtime,
+                Image **ret) {
+
+        _cleanup_(image_unrefp) Image *i = NULL;
+
+        assert(t >= 0);
+        assert(t < _IMAGE_TYPE_MAX);
+        assert(pretty);
+        assert(filename);
+        assert(ret);
+
+        i = new0(Image, 1);
+        if (!i)
+                return -ENOMEM;
+
+        i->n_ref = 1;
+        i->type = t;
+        i->read_only = read_only;
+        i->crtime = crtime;
+        i->mtime = mtime;
+        i->usage = i->usage_exclusive = (uint64_t) -1;
+        i->limit = i->limit_exclusive = (uint64_t) -1;
+
+        i->name = strdup(pretty);
+        if (!i->name)
+                return -ENOMEM;
+
+        if (path)
+                i->path = strjoin(path, "/", filename);
+        else
+                i->path = strdup(filename);
+        if (!i->path)
+                return -ENOMEM;
+
+        path_simplify(i->path, false);
+
+        *ret = TAKE_PTR(i);
+
+        return 0;
+}
+
+static int extract_pretty(const char *path, const char *suffix, char **ret) {
+        _cleanup_free_ char *name = NULL;
+        const char *p;
+        size_t n;
+
+        assert(path);
+        assert(ret);
+
+        p = last_path_component(path);
+        n = strcspn(p, "/");
+
+        name = strndup(p, n);
+        if (!name)
+                return -ENOMEM;
+
+        if (suffix) {
+                char *e;
+
+                e = endswith(name, suffix);
+                if (!e)
+                        return -EINVAL;
+
+                *e = 0;
+        }
+
+        if (!image_name_is_valid(name))
+                return -EINVAL;
+
+        *ret = TAKE_PTR(name);
+        return 0;
+}
+
+static int image_make(
+                const char *pretty,
+                int dfd,
+                const char *path,
+                const char *filename,
+                const struct stat *st,
+                Image **ret) {
+
+        _cleanup_free_ char *pretty_buffer = NULL;
+        struct stat stbuf;
+        bool read_only;
+        int r;
+
+        assert(dfd >= 0 || dfd == AT_FDCWD);
+        assert(filename);
+
+        /* We explicitly *do* follow symlinks here, since we want to allow symlinking trees, raw files and block
+         * devices into /var/lib/machines/, and treat them normally.
+         *
+         * This function returns -ENOENT if we can't find the image after all, and -EMEDIUMTYPE if it's not a file we
+         * recognize. */
+
+        if (!st) {
+                if (fstatat(dfd, filename, &stbuf, 0) < 0)
+                        return -errno;
+
+                st = &stbuf;
+        }
+
+        read_only =
+                (path && path_startswith(path, "/usr")) ||
+                (faccessat(dfd, filename, W_OK, AT_EACCESS) < 0 && errno == EROFS);
+
+        if (S_ISDIR(st->st_mode)) {
+                _cleanup_close_ int fd = -1;
+                unsigned file_attr = 0;
+
+                if (!ret)
+                        return 0;
+
+                if (!pretty) {
+                        r = extract_pretty(filename, NULL, &pretty_buffer);
+                        if (r < 0)
+                                return r;
+
+                        pretty = pretty_buffer;
+                }
+
+                fd = openat(dfd, filename, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
+                if (fd < 0)
+                        return -errno;
+
+                /* btrfs subvolumes have inode 256 */
+                if (st->st_ino == 256) {
+
+                        r = btrfs_is_filesystem(fd);
+                        if (r < 0)
+                                return r;
+                        if (r) {
+                                BtrfsSubvolInfo info;
+
+                                /* It's a btrfs subvolume */
+
+                                r = btrfs_subvol_get_info_fd(fd, 0, &info);
+                                if (r < 0)
+                                        return r;
+
+                                r = image_new(IMAGE_SUBVOLUME,
+                                              pretty,
+                                              path,
+                                              filename,
+                                              info.read_only || read_only,
+                                              info.otime,
+                                              0,
+                                              ret);
+                                if (r < 0)
+                                        return r;
+
+                                if (btrfs_quota_scan_ongoing(fd) == 0) {
+                                        BtrfsQuotaInfo quota;
+
+                                        r = btrfs_subvol_get_subtree_quota_fd(fd, 0, &quota);
+                                        if (r >= 0) {
+                                                (*ret)->usage = quota.referenced;
+                                                (*ret)->usage_exclusive = quota.exclusive;
+
+                                                (*ret)->limit = quota.referenced_max;
+                                                (*ret)->limit_exclusive = quota.exclusive_max;
+                                        }
+                                }
+
+                                return 0;
+                        }
+                }
+
+                /* If the IMMUTABLE bit is set, we consider the
+                 * directory read-only. Since the ioctl is not
+                 * supported everywhere we ignore failures. */
+                (void) read_attr_fd(fd, &file_attr);
+
+                /* It's just a normal directory. */
+                r = image_new(IMAGE_DIRECTORY,
+                              pretty,
+                              path,
+                              filename,
+                              read_only || (file_attr & FS_IMMUTABLE_FL),
+                              0,
+                              0,
+                              ret);
+                if (r < 0)
+                        return r;
+
+                return 0;
+
+        } else if (S_ISREG(st->st_mode) && endswith(filename, ".raw")) {
+                usec_t crtime = 0;
+
+                /* It's a RAW disk image */
+
+                if (!ret)
+                        return 0;
+
+                (void) fd_getcrtime_at(dfd, filename, &crtime, 0);
+
+                if (!pretty) {
+                        r = extract_pretty(filename, ".raw", &pretty_buffer);
+                        if (r < 0)
+                                return r;
+
+                        pretty = pretty_buffer;
+                }
+
+                r = image_new(IMAGE_RAW,
+                              pretty,
+                              path,
+                              filename,
+                              !(st->st_mode & 0222) || read_only,
+                              crtime,
+                              timespec_load(&st->st_mtim),
+                              ret);
+                if (r < 0)
+                        return r;
+
+                (*ret)->usage = (*ret)->usage_exclusive = st->st_blocks * 512;
+                (*ret)->limit = (*ret)->limit_exclusive = st->st_size;
+
+                return 0;
+
+        } else if (S_ISBLK(st->st_mode)) {
+                _cleanup_close_ int block_fd = -1;
+                uint64_t size = UINT64_MAX;
+
+                /* A block device */
+
+                if (!ret)
+                        return 0;
+
+                if (!pretty) {
+                        r = extract_pretty(filename, NULL, &pretty_buffer);
+                        if (r < 0)
+                                return r;
+
+                        pretty = pretty_buffer;
+                }
+
+                block_fd = openat(dfd, filename, O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_NOCTTY);
+                if (block_fd < 0)
+                        log_debug_errno(errno, "Failed to open block device %s/%s, ignoring: %m", path, filename);
+                else {
+                        /* Refresh stat data after opening the node */
+                        if (fstat(block_fd, &stbuf) < 0)
+                                return -errno;
+                        st = &stbuf;
+
+                        if (!S_ISBLK(st->st_mode)) /* Verify that what we opened is actually what we think it is */
+                                return -ENOTTY;
+
+                        if (!read_only) {
+                                int state = 0;
+
+                                if (ioctl(block_fd, BLKROGET, &state) < 0)
+                                        log_debug_errno(errno, "Failed to issue BLKROGET on device %s/%s, ignoring: %m", path, filename);
+                                else if (state)
+                                        read_only = true;
+                        }
+
+                        if (ioctl(block_fd, BLKGETSIZE64, &size) < 0)
+                                log_debug_errno(errno, "Failed to issue BLKGETSIZE64 on device %s/%s, ignoring: %m", path, filename);
+
+                        block_fd = safe_close(block_fd);
+                }
+
+                r = image_new(IMAGE_BLOCK,
+                              pretty,
+                              path,
+                              filename,
+                              !(st->st_mode & 0222) || read_only,
+                              0,
+                              0,
+                              ret);
+                if (r < 0)
+                        return r;
+
+                if (size != 0 && size != UINT64_MAX)
+                        (*ret)->usage = (*ret)->usage_exclusive = (*ret)->limit = (*ret)->limit_exclusive = size;
+
+                return 0;
+        }
+
+        return -EMEDIUMTYPE;
+}
+
+int image_find(ImageClass class, const char *name, Image **ret) {
+        const char *path;
+        int r;
+
+        assert(class >= 0);
+        assert(class < _IMAGE_CLASS_MAX);
+        assert(name);
+
+        /* There are no images with invalid names */
+        if (!image_name_is_valid(name))
+                return -ENOENT;
+
+        NULSTR_FOREACH(path, image_search_path[class]) {
+                _cleanup_closedir_ DIR *d = NULL;
+                struct stat st;
+
+                d = opendir(path);
+                if (!d) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        return -errno;
+                }
+
+                /* As mentioned above, we follow symlinks on this fstatat(), because we want to permit people to
+                 * symlink block devices into the search path */
+                if (fstatat(dirfd(d), name, &st, 0) < 0) {
+                        _cleanup_free_ char *raw = NULL;
+
+                        if (errno != ENOENT)
+                                return -errno;
+
+                        raw = strappend(name, ".raw");
+                        if (!raw)
+                                return -ENOMEM;
+
+                        if (fstatat(dirfd(d), raw, &st, 0) < 0) {
+
+                                if (errno == ENOENT)
+                                        continue;
+
+                                return -errno;
+                        }
+
+                        if (!S_ISREG(st.st_mode))
+                                continue;
+
+                        r = image_make(name, dirfd(d), path, raw, &st, ret);
+
+                } else {
+                        if (!S_ISDIR(st.st_mode) && !S_ISBLK(st.st_mode))
+                                continue;
+
+                        r = image_make(name, dirfd(d), path, name, &st, ret);
+                }
+                if (IN_SET(r, -ENOENT, -EMEDIUMTYPE))
+                        continue;
+                if (r < 0)
+                        return r;
+
+                if (ret)
+                        (*ret)->discoverable = true;
+
+                return 1;
+        }
+
+        if (class == IMAGE_MACHINE && streq(name, ".host")) {
+                r = image_make(".host", AT_FDCWD, NULL, "/", NULL, ret);
+                if (r < 0)
+                        return r;
+
+                if (ret)
+                        (*ret)->discoverable = true;
+
+                return r;
+        }
+
+        return -ENOENT;
+};
+
+int image_from_path(const char *path, Image **ret) {
+
+        /* Note that we don't set the 'discoverable' field of the returned object, because we don't check here whether
+         * the image is in the image search path. And if it is we don't know if the path we used is actually not
+         * overridden by another, different image earlier in the search path */
+
+        if (path_equal(path, "/"))
+                return image_make(".host", AT_FDCWD, NULL, "/", NULL, ret);
+
+        return image_make(NULL, AT_FDCWD, NULL, path, NULL, ret);
+}
+
+int image_find_harder(ImageClass class, const char *name_or_path, Image **ret) {
+        if (image_name_is_valid(name_or_path))
+                return image_find(class, name_or_path, ret);
+
+        return image_from_path(name_or_path, ret);
+}
+
+int image_discover(ImageClass class, Hashmap *h) {
+        const char *path;
+        int r;
+
+        assert(class >= 0);
+        assert(class < _IMAGE_CLASS_MAX);
+        assert(h);
+
+        NULSTR_FOREACH(path, image_search_path[class]) {
+                _cleanup_closedir_ DIR *d = NULL;
+                struct dirent *de;
+
+                d = opendir(path);
+                if (!d) {
+                        if (errno == ENOENT)
+                                continue;
+
+                        return -errno;
+                }
+
+                FOREACH_DIRENT_ALL(de, d, return -errno) {
+                        _cleanup_(image_unrefp) Image *image = NULL;
+                        _cleanup_free_ char *truncated = NULL;
+                        const char *pretty;
+                        struct stat st;
+
+                        if (dot_or_dot_dot(de->d_name))
+                                continue;
+
+                        /* As mentioned above, we follow symlinks on this fstatat(), because we want to permit people
+                         * to symlink block devices into the search path */
+                        if (fstatat(dirfd(d), de->d_name, &st, 0) < 0) {
+                                if (errno == ENOENT)
+                                        continue;
+
+                                return -errno;
+                        }
+
+                        if (S_ISREG(st.st_mode)) {
+                                const char *e;
+
+                                e = endswith(de->d_name, ".raw");
+                                if (!e)
+                                        continue;
+
+                                truncated = strndup(de->d_name, e - de->d_name);
+                                if (!truncated)
+                                        return -ENOMEM;
+
+                                pretty = truncated;
+                        } else if (S_ISDIR(st.st_mode) || S_ISBLK(st.st_mode))
+                                pretty = de->d_name;
+                        else
+                                continue;
+
+                        if (!image_name_is_valid(pretty))
+                                continue;
+
+                        if (hashmap_contains(h, pretty))
+                                continue;
+
+                        r = image_make(pretty, dirfd(d), path, de->d_name, &st, &image);
+                        if (IN_SET(r, -ENOENT, -EMEDIUMTYPE))
+                                continue;
+                        if (r < 0)
+                                return r;
+
+                        image->discoverable = true;
+
+                        r = hashmap_put(h, image->name, image);
+                        if (r < 0)
+                                return r;
+
+                        image = NULL;
+                }
+        }
+
+        if (class == IMAGE_MACHINE && !hashmap_contains(h, ".host")) {
+                _cleanup_(image_unrefp) Image *image = NULL;
+
+                r = image_make(".host", AT_FDCWD, NULL, "/", NULL, &image);
+                if (r < 0)
+                        return r;
+
+                image->discoverable = true;
+
+                r = hashmap_put(h, image->name, image);
+                if (r < 0)
+                        return r;
+
+                image = NULL;
+        }
+
+        return 0;
+}
+
+int image_remove(Image *i) {
+        _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+        _cleanup_strv_free_ char **settings = NULL;
+        _cleanup_free_ char *roothash = NULL;
+        char **j;
+        int r;
+
+        assert(i);
+
+        if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+                return -EROFS;
+
+        settings = image_settings_path(i);
+        if (!settings)
+                return -ENOMEM;
+
+        roothash = image_roothash_path(i);
+        if (!roothash)
+                return -ENOMEM;
+
+        /* Make sure we don't interfere with a running nspawn */
+        r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+        if (r < 0)
+                return r;
+
+        switch (i->type) {
+
+        case IMAGE_SUBVOLUME:
+
+                /* Let's unlink first, maybe it is a symlink? If that works we are happy. Otherwise, let's get out the
+                 * big guns */
+                if (unlink(i->path) < 0) {
+                        r = btrfs_subvol_remove(i->path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA);
+                        if (r < 0)
+                                return r;
+                }
+
+                break;
+
+        case IMAGE_DIRECTORY:
+                /* Allow deletion of read-only directories */
+                (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL, NULL);
+                r = rm_rf(i->path, REMOVE_ROOT|REMOVE_PHYSICAL|REMOVE_SUBVOLUME);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case IMAGE_BLOCK:
+
+                /* If this is inside of /dev, then it's a real block device, hence let's not touch the device node
+                 * itself (but let's remove the stuff stored alongside it). If it's anywhere else, let's try to unlink
+                 * the thing (it's most likely a symlink after all). */
+
+                if (path_startswith(i->path, "/dev"))
+                        break;
+
+                _fallthrough_;
+        case IMAGE_RAW:
+                if (unlink(i->path) < 0)
+                        return -errno;
+                break;
+
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        STRV_FOREACH(j, settings) {
+                if (unlink(*j) < 0 && errno != ENOENT)
+                        log_debug_errno(errno, "Failed to unlink %s, ignoring: %m", *j);
+        }
+
+        if (unlink(roothash) < 0 && errno != ENOENT)
+                log_debug_errno(errno, "Failed to unlink %s, ignoring: %m", roothash);
+
+        return 0;
+}
+
+static int rename_auxiliary_file(const char *path, const char *new_name, const char *suffix) {
+        _cleanup_free_ char *rs = NULL;
+        const char *fn;
+
+        fn = strjoina(new_name, suffix);
+
+        rs = file_in_same_dir(path, fn);
+        if (!rs)
+                return -ENOMEM;
+
+        return rename_noreplace(AT_FDCWD, path, AT_FDCWD, rs);
+}
+
+int image_rename(Image *i, const char *new_name) {
+        _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT, name_lock = LOCK_FILE_INIT;
+        _cleanup_free_ char *new_path = NULL, *nn = NULL, *roothash = NULL;
+        _cleanup_strv_free_ char **settings = NULL;
+        unsigned file_attr = 0;
+        char **j;
+        int r;
+
+        assert(i);
+
+        if (!image_name_is_valid(new_name))
+                return -EINVAL;
+
+        if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+                return -EROFS;
+
+        settings = image_settings_path(i);
+        if (!settings)
+                return -ENOMEM;
+
+        roothash = image_roothash_path(i);
+        if (!roothash)
+                return -ENOMEM;
+
+        /* Make sure we don't interfere with a running nspawn */
+        r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+        if (r < 0)
+                return r;
+
+        /* Make sure nobody takes the new name, between the time we
+         * checked it is currently unused in all search paths, and the
+         * time we take possession of it */
+        r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
+        if (r < 0)
+                return r;
+
+        r = image_find(IMAGE_MACHINE, new_name, NULL);
+        if (r >= 0)
+                return -EEXIST;
+        if (r != -ENOENT)
+                return r;
+
+        switch (i->type) {
+
+        case IMAGE_DIRECTORY:
+                /* Turn of the immutable bit while we rename the image, so that we can rename it */
+                (void) read_attr_path(i->path, &file_attr);
+
+                if (file_attr & FS_IMMUTABLE_FL)
+                        (void) chattr_path(i->path, 0, FS_IMMUTABLE_FL, NULL);
+
+                _fallthrough_;
+        case IMAGE_SUBVOLUME:
+                new_path = file_in_same_dir(i->path, new_name);
+                break;
+
+        case IMAGE_BLOCK:
+
+                /* Refuse renaming raw block devices in /dev, the names are picked by udev after all. */
+                if (path_startswith(i->path, "/dev"))
+                        return -EROFS;
+
+                new_path = file_in_same_dir(i->path, new_name);
+                break;
+
+        case IMAGE_RAW: {
+                const char *fn;
+
+                fn = strjoina(new_name, ".raw");
+                new_path = file_in_same_dir(i->path, fn);
+                break;
+        }
+
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        if (!new_path)
+                return -ENOMEM;
+
+        nn = strdup(new_name);
+        if (!nn)
+                return -ENOMEM;
+
+        r = rename_noreplace(AT_FDCWD, i->path, AT_FDCWD, new_path);
+        if (r < 0)
+                return r;
+
+        /* Restore the immutable bit, if it was set before */
+        if (file_attr & FS_IMMUTABLE_FL)
+                (void) chattr_path(new_path, FS_IMMUTABLE_FL, FS_IMMUTABLE_FL, NULL);
+
+        free_and_replace(i->path, new_path);
+        free_and_replace(i->name, nn);
+
+        STRV_FOREACH(j, settings) {
+                r = rename_auxiliary_file(*j, new_name, ".nspawn");
+                if (r < 0 && r != -ENOENT)
+                        log_debug_errno(r, "Failed to rename settings file %s, ignoring: %m", *j);
+        }
+
+        r = rename_auxiliary_file(roothash, new_name, ".roothash");
+        if (r < 0 && r != -ENOENT)
+                log_debug_errno(r, "Failed to rename roothash file %s, ignoring: %m", roothash);
+
+        return 0;
+}
+
+static int clone_auxiliary_file(const char *path, const char *new_name, const char *suffix) {
+        _cleanup_free_ char *rs = NULL;
+        const char *fn;
+
+        fn = strjoina(new_name, suffix);
+
+        rs = file_in_same_dir(path, fn);
+        if (!rs)
+                return -ENOMEM;
+
+        return copy_file_atomic(path, rs, 0664, 0, COPY_REFLINK);
+}
+
+int image_clone(Image *i, const char *new_name, bool read_only) {
+        _cleanup_(release_lock_file) LockFile name_lock = LOCK_FILE_INIT;
+        _cleanup_strv_free_ char **settings = NULL;
+        _cleanup_free_ char *roothash = NULL;
+        const char *new_path;
+        char **j;
+        int r;
+
+        assert(i);
+
+        if (!image_name_is_valid(new_name))
+                return -EINVAL;
+
+        settings = image_settings_path(i);
+        if (!settings)
+                return -ENOMEM;
+
+        roothash = image_roothash_path(i);
+        if (!roothash)
+                return -ENOMEM;
+
+        /* Make sure nobody takes the new name, between the time we
+         * checked it is currently unused in all search paths, and the
+         * time we take possession of it */
+        r = image_name_lock(new_name, LOCK_EX|LOCK_NB, &name_lock);
+        if (r < 0)
+                return r;
+
+        r = image_find(IMAGE_MACHINE, new_name, NULL);
+        if (r >= 0)
+                return -EEXIST;
+        if (r != -ENOENT)
+                return r;
+
+        switch (i->type) {
+
+        case IMAGE_SUBVOLUME:
+        case IMAGE_DIRECTORY:
+                /* If we can we'll always try to create a new btrfs subvolume here, even if the source is a plain
+                 * directory. */
+
+                new_path = strjoina("/var/lib/machines/", new_name);
+
+                r = btrfs_subvol_snapshot(i->path, new_path,
+                                          (read_only ? BTRFS_SNAPSHOT_READ_ONLY : 0) |
+                                          BTRFS_SNAPSHOT_FALLBACK_COPY |
+                                          BTRFS_SNAPSHOT_FALLBACK_DIRECTORY |
+                                          BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE |
+                                          BTRFS_SNAPSHOT_RECURSIVE |
+                                          BTRFS_SNAPSHOT_QUOTA);
+                if (r >= 0)
+                        /* Enable "subtree" quotas for the copy, if we didn't copy any quota from the source. */
+                        (void) btrfs_subvol_auto_qgroup(new_path, 0, true);
+
+                break;
+
+        case IMAGE_RAW:
+                new_path = strjoina("/var/lib/machines/", new_name, ".raw");
+
+                r = copy_file_atomic(i->path, new_path, read_only ? 0444 : 0644, FS_NOCOW_FL, COPY_REFLINK);
+                break;
+
+        case IMAGE_BLOCK:
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(j, settings) {
+                r = clone_auxiliary_file(*j, new_name, ".nspawn");
+                if (r < 0 && r != -ENOENT)
+                        log_debug_errno(r, "Failed to clone settings %s, ignoring: %m", *j);
+        }
+
+        r = clone_auxiliary_file(roothash, new_name, ".roothash");
+        if (r < 0 && r != -ENOENT)
+                log_debug_errno(r, "Failed to clone root hash file %s, ignoring: %m", roothash);
+
+        return 0;
+}
+
+int image_read_only(Image *i, bool b) {
+        _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+        int r;
+
+        assert(i);
+
+        if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+                return -EROFS;
+
+        /* Make sure we don't interfere with a running nspawn */
+        r = image_path_lock(i->path, LOCK_EX|LOCK_NB, &global_lock, &local_lock);
+        if (r < 0)
+                return r;
+
+        switch (i->type) {
+
+        case IMAGE_SUBVOLUME:
+
+                /* Note that we set the flag only on the top-level
+                 * subvolume of the image. */
+
+                r = btrfs_subvol_set_read_only(i->path, b);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case IMAGE_DIRECTORY:
+                /* For simple directory trees we cannot use the access
+                   mode of the top-level directory, since it has an
+                   effect on the container itself.  However, we can
+                   use the "immutable" flag, to at least make the
+                   top-level directory read-only. It's not as good as
+                   a read-only subvolume, but at least something, and
+                   we can read the value back. */
+
+                r = chattr_path(i->path, b ? FS_IMMUTABLE_FL : 0, FS_IMMUTABLE_FL, NULL);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case IMAGE_RAW: {
+                struct stat st;
+
+                if (stat(i->path, &st) < 0)
+                        return -errno;
+
+                if (chmod(i->path, (st.st_mode & 0444) | (b ? 0000 : 0200)) < 0)
+                        return -errno;
+
+                /* If the images is now read-only, it's a good time to
+                 * defrag it, given that no write patterns will
+                 * fragment it again. */
+                if (b)
+                        (void) btrfs_defrag(i->path);
+                break;
+        }
+
+        case IMAGE_BLOCK: {
+                _cleanup_close_ int fd = -1;
+                struct stat st;
+                int state = b;
+
+                fd = open(i->path, O_CLOEXEC|O_RDONLY|O_NONBLOCK|O_NOCTTY);
+                if (fd < 0)
+                        return -errno;
+
+                if (fstat(fd, &st) < 0)
+                        return -errno;
+                if (!S_ISBLK(st.st_mode))
+                        return -ENOTTY;
+
+                if (ioctl(fd, BLKROSET, &state) < 0)
+                        return -errno;
+
+                break;
+        }
+
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        return 0;
+}
+
+int image_path_lock(const char *path, int operation, LockFile *global, LockFile *local) {
+        _cleanup_free_ char *p = NULL;
+        LockFile t = LOCK_FILE_INIT;
+        struct stat st;
+        int r;
+
+        assert(path);
+        assert(global);
+        assert(local);
+
+        /* Locks an image path. This actually creates two locks: one
+         * "local" one, next to the image path itself, which might be
+         * shared via NFS. And another "global" one, in /run, that
+         * uses the device/inode number. This has the benefit that we
+         * can even lock a tree that is a mount point, correctly. */
+
+        if (!path_is_absolute(path))
+                return -EINVAL;
+
+        if (getenv_bool("SYSTEMD_NSPAWN_LOCK") == 0) {
+                *local = *global = (LockFile) LOCK_FILE_INIT;
+                return 0;
+        }
+
+        if (path_equal(path, "/"))
+                return -EBUSY;
+
+        if (stat(path, &st) >= 0) {
+                if (S_ISBLK(st.st_mode))
+                        r = asprintf(&p, "/run/systemd/nspawn/locks/block-%u:%u", major(st.st_rdev), minor(st.st_rdev));
+                else if (S_ISDIR(st.st_mode) || S_ISREG(st.st_mode))
+                        r = asprintf(&p, "/run/systemd/nspawn/locks/inode-%lu:%lu", (unsigned long) st.st_dev, (unsigned long) st.st_ino);
+                else
+                        return -ENOTTY;
+
+                if (r < 0)
+                        return -ENOMEM;
+        }
+
+        /* For block devices we don't need the "local" lock, as the major/minor lock above should be sufficient, since
+         * block devices are device local anyway. */
+        if (!path_startswith(path, "/dev")) {
+                r = make_lock_file_for(path, operation, &t);
+                if (r < 0) {
+                        if ((operation & LOCK_SH) && r == -EROFS)
+                                log_debug_errno(r, "Failed to create shared lock for '%s', ignoring: %m", path);
+                        else
+                                return r;
+                }
+        }
+
+        if (p) {
+                mkdir_p("/run/systemd/nspawn/locks", 0700);
+
+                r = make_lock_file(p, operation, global);
+                if (r < 0) {
+                        release_lock_file(&t);
+                        return r;
+                }
+        } else
+                *global = (LockFile) LOCK_FILE_INIT;
+
+        *local = t;
+        return 0;
+}
+
+int image_set_limit(Image *i, uint64_t referenced_max) {
+        assert(i);
+
+        if (IMAGE_IS_VENDOR(i) || IMAGE_IS_HOST(i))
+                return -EROFS;
+
+        if (i->type != IMAGE_SUBVOLUME)
+                return -EOPNOTSUPP;
+
+        /* We set the quota both for the subvolume as well as for the
+         * subtree. The latter is mostly for historical reasons, since
+         * we didn't use to have a concept of subtree quota, and hence
+         * only modified the subvolume quota. */
+
+        (void) btrfs_qgroup_set_limit(i->path, 0, referenced_max);
+        (void) btrfs_subvol_auto_qgroup(i->path, 0, true);
+        return btrfs_subvol_set_subtree_quota_limit(i->path, 0, referenced_max);
+}
+
+int image_read_metadata(Image *i) {
+        _cleanup_(release_lock_file) LockFile global_lock = LOCK_FILE_INIT, local_lock = LOCK_FILE_INIT;
+        int r;
+
+        assert(i);
+
+        r = image_path_lock(i->path, LOCK_SH|LOCK_NB, &global_lock, &local_lock);
+        if (r < 0)
+                return r;
+
+        switch (i->type) {
+
+        case IMAGE_SUBVOLUME:
+        case IMAGE_DIRECTORY: {
+                _cleanup_strv_free_ char **machine_info = NULL, **os_release = NULL;
+                sd_id128_t machine_id = SD_ID128_NULL;
+                _cleanup_free_ char *hostname = NULL;
+                _cleanup_free_ char *path = NULL;
+
+                r = chase_symlinks("/etc/hostname", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path);
+                if (r < 0 && r != -ENOENT)
+                        log_debug_errno(r, "Failed to chase /etc/hostname in image %s: %m", i->name);
+                else if (r >= 0) {
+                        r = read_etc_hostname(path, &hostname);
+                        if (r < 0)
+                                log_debug_errno(errno, "Failed to read /etc/hostname of image %s: %m", i->name);
+                }
+
+                path = mfree(path);
+
+                r = chase_symlinks("/etc/machine-id", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path);
+                if (r < 0 && r != -ENOENT)
+                        log_debug_errno(r, "Failed to chase /etc/machine-id in image %s: %m", i->name);
+                else if (r >= 0) {
+                        _cleanup_close_ int fd = -1;
+
+                        fd = open(path, O_RDONLY|O_CLOEXEC|O_NOCTTY);
+                        if (fd < 0)
+                                log_debug_errno(errno, "Failed to open %s: %m", path);
+                        else {
+                                r = id128_read_fd(fd, ID128_PLAIN, &machine_id);
+                                if (r < 0)
+                                        log_debug_errno(r, "Image %s contains invalid machine ID.", i->name);
+                        }
+                }
+
+                path = mfree(path);
+
+                r = chase_symlinks("/etc/machine-info", i->path, CHASE_PREFIX_ROOT|CHASE_TRAIL_SLASH, &path);
+                if (r < 0 && r != -ENOENT)
+                        log_debug_errno(r, "Failed to chase /etc/machine-info in image %s: %m", i->name);
+                else if (r >= 0) {
+                        r = load_env_file_pairs(NULL, path, &machine_info);
+                        if (r < 0)
+                                log_debug_errno(r, "Failed to parse machine-info data of %s: %m", i->name);
+                }
+
+                r = load_os_release_pairs(i->path, &os_release);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to read os-release in image, ignoring: %m");
+
+                free_and_replace(i->hostname, hostname);
+                i->machine_id = machine_id;
+                strv_free_and_replace(i->machine_info, machine_info);
+                strv_free_and_replace(i->os_release, os_release);
+
+                break;
+        }
+
+        case IMAGE_RAW:
+        case IMAGE_BLOCK: {
+                _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
+                _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
+
+                r = loop_device_make_by_path(i->path, O_RDONLY, &d);
+                if (r < 0)
+                        return r;
+
+                r = dissect_image(d->fd, NULL, 0, DISSECT_IMAGE_REQUIRE_ROOT, &m);
+                if (r < 0)
+                        return r;
+
+                r = dissected_image_acquire_metadata(m);
+                if (r < 0)
+                        return r;
+
+                free_and_replace(i->hostname, m->hostname);
+                i->machine_id = m->machine_id;
+                strv_free_and_replace(i->machine_info, m->machine_info);
+                strv_free_and_replace(i->os_release, m->os_release);
+
+                break;
+        }
+
+        default:
+                return -EOPNOTSUPP;
+        }
+
+        i->metadata_valid = true;
+
+        return 0;
+}
+
+int image_name_lock(const char *name, int operation, LockFile *ret) {
+        const char *p;
+
+        assert(name);
+        assert(ret);
+
+        /* Locks an image name, regardless of the precise path used. */
+
+        if (!image_name_is_valid(name))
+                return -EINVAL;
+
+        if (getenv_bool("SYSTEMD_NSPAWN_LOCK") == 0) {
+                *ret = (LockFile) LOCK_FILE_INIT;
+                return 0;
+        }
+
+        if (streq(name, ".host"))
+                return -EBUSY;
+
+        mkdir_p("/run/systemd/nspawn/locks", 0700);
+        p = strjoina("/run/systemd/nspawn/locks/name-", name);
+
+        return make_lock_file(p, operation, ret);
+}
+
+bool image_name_is_valid(const char *s) {
+        if (!filename_is_valid(s))
+                return false;
+
+        if (string_has_cc(s, NULL))
+                return false;
+
+        if (!utf8_is_valid(s))
+                return false;
+
+        /* Temporary files for atomically creating new files */
+        if (startswith(s, ".#"))
+                return false;
+
+        return true;
+}
+
+bool image_in_search_path(ImageClass class, const char *image) {
+        const char *path;
+
+        assert(image);
+
+        NULSTR_FOREACH(path, image_search_path[class]) {
+                const char *p;
+                size_t k;
+
+                p = path_startswith(image, path);
+                if (!p)
+                        continue;
+
+                /* Make sure there's a filename following */
+                k = strcspn(p, "/");
+                if (k == 0)
+                        continue;
+
+                p += k;
+
+                /* Accept trailing slashes */
+                if (p[strspn(p, "/")] == 0)
+                        return true;
+
+        }
+
+        return false;
+}
+
+static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
+        [IMAGE_DIRECTORY] = "directory",
+        [IMAGE_SUBVOLUME] = "subvolume",
+        [IMAGE_RAW] = "raw",
+        [IMAGE_BLOCK] = "block",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);