image.c revision cd61c3bfd718fb398cc53ced906266a9297782c9
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <sys/statfs.h>
#include "strv.h"
#include "utf8.h"
#include "btrfs-util.h"
#include "image.h"
#include "bus-label.h"
Image *image_unref(Image *i) {
if (!i)
return NULL;
free(i->name);
free(i->path);
free(i);
return NULL;
}
static int add_image(
Hashmap *h,
ImageType t,
const char *name,
const char *path,
bool read_only,
usec_t mtime,
usec_t btime) {
_cleanup_(image_unrefp) Image *i = NULL;
int r;
assert(h);
assert(t >= 0);
assert(t < _IMAGE_TYPE_MAX);
assert(name);
i = new(Image, 1);
if (!i)
return -ENOMEM;
i->type = t;
i->read_only = read_only;
i->mtime = mtime;
i->btime = btime;
i->name = strdup(name);
if (!i->name)
return -ENOMEM;
if (path) {
i->path = strdup(path);
if (!i->path)
return -ENOMEM;
}
r = hashmap_put(h, i->name, i);
if (r < 0)
return r;
i = NULL;
return 0;
}
int image_discover(Hashmap *h) {
const char *path;
int r;
assert(h);
FOREACH_STRING(path, "/var/lib/container", "/var/lib/machine") {
_cleanup_closedir_ DIR *d = NULL;
struct dirent *de;
d = opendir(path);
if (!d) {
if (errno == ENOENT)
return 0;
return -errno;
}
FOREACH_DIRENT_ALL(de, d, return -errno) {
struct stat st;
if (STR_IN_SET(de->d_name, ".", ".."))
continue;
/* Temporary files for atomically creating new files */
if (startswith(de->d_name, ".#"))
continue;
if (string_has_cc(de->d_name, NULL))
continue;
if (!utf8_is_valid(de->d_name))
continue;
if (hashmap_contains(h, de->d_name))
continue;
/* We explicitly *do* follow symlinks here,
* since we want to allow symlinking trees
* into /var/lib/container/, and treat them
* normally. */
if (fstatat(dirfd(d), de->d_name, &st, 0) < 0) {
if (errno == ENOENT)
continue;
return -errno;
}
if (S_ISDIR(st.st_mode)) {
/* btrfs subvolumes have inode 256 */
if (st.st_ino == 256) {
_cleanup_close_ int fd = -1;
struct statfs sfs;
fd = openat(dirfd(d), de->d_name, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
if (fd < 0) {
if (errno == ENOENT)
continue;
return -errno;
}
if (fstatfs(fd, &sfs) < 0)
return -errno;
if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC)) {
usec_t btime = 0;
int ro;
/* It's a btrfs subvolume */
ro = btrfs_subvol_is_read_only_fd(fd);
if (ro < 0)
return ro;
/* r = btrfs_subvol_get_btime(fd, &btime); */
/* if (r < 0) */
/* return r; */
r = add_image(h,
IMAGE_SUBVOLUME,
de->d_name,
path,
ro,
0,
btime);
if (r < 0)
return r;
continue;
}
}
/* It's just a normal directory. */
r = add_image(h,
IMAGE_DIRECTORY,
de->d_name,
path,
false,
0,
0);
if (r < 0)
return r;
} else if (S_ISREG(st.st_mode) &&
endswith(de->d_name, ".gpt")) {
/* It's a GPT block device */
r = add_image(h,
IMAGE_GPT,
de->d_name,
path,
!!(st.st_mode & 0111),
timespec_load(&st.st_mtim),
0);
if (r < 0)
return r;
}
}
}
return 0;
}
void image_hashmap_free(Hashmap *map) {
Image *i;
while ((i = hashmap_steal_first(map)))
image_unref(i);
hashmap_free(map);
}
char *image_bus_path(const char *name) {
_cleanup_free_ char *e = NULL;
assert(name);
e = bus_label_escape(name);
if (!e)
return NULL;
return strappend("/org/freedesktop/machine1/image/", e);
}
static const char* const image_type_table[_IMAGE_TYPE_MAX] = {
[IMAGE_DIRECTORY] = "directory",
[IMAGE_SUBVOLUME] = "subvolume",
[IMAGE_GPT] = "gpt",
};
DEFINE_STRING_TABLE_LOOKUP(image_type, ImageType);