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authorLennart Poettering <lennart@poettering.net>2014-12-27 01:57:03 +0100
committerLennart Poettering <lennart@poettering.net>2014-12-28 02:08:40 +0100
commit003dffde2c1b93afbc9aff24b277276f65424406 (patch)
tree5b8cf0f35d901fcbac23dcc0a5f9bc3121ef2191 /src/shared/machine-image.c
parent58a489c2b3628f3003d3901537bec8b5e6c1b7bd (diff)
machined: Move image discovery logic into src/shared, so that we can make use of it from nspawn
Diffstat (limited to 'src/shared/machine-image.c')
-rw-r--r--src/shared/machine-image.c325
1 files changed, 325 insertions, 0 deletions
diff --git a/src/shared/machine-image.c b/src/shared/machine-image.c
new file mode 100644
index 0000000000..51f89d5921
--- /dev/null
+++ b/src/shared/machine-image.c
@@ -0,0 +1,325 @@
+/*-*- 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 "path-util.h"
+#include "machine-image.h"
+
+static const char image_search_path[] =
+ "/var/lib/machines\0"
+ "/var/lib/container\0"
+ "/usr/local/lib/machines\0"
+ "/usr/lib/machines\0";
+
+Image *image_unref(Image *i) {
+ if (!i)
+ return NULL;
+
+ free(i->name);
+ free(i->path);
+ free(i);
+ return NULL;
+}
+
+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->type = t;
+ i->read_only = read_only;
+ i->crtime = crtime;
+ i->mtime = mtime;
+
+ i->name = strdup(pretty);
+ if (!i->name)
+ return -ENOMEM;
+
+ if (path)
+ i->path = strjoin(path, "/", filename, NULL);
+ else
+ i->path = strdup(filename);
+
+ if (!i->path)
+ return -ENOMEM;
+
+ path_kill_slashes(i->path);
+
+ *ret = i;
+ i = NULL;
+
+ return 0;
+}
+
+static int image_make(
+ const char *pretty,
+ int dfd,
+ const char *path,
+ const char *filename,
+ Image **ret) {
+
+ struct stat st;
+ bool read_only;
+ int r;
+
+ assert(filename);
+
+ /* We explicitly *do* follow symlinks here, since we want to
+ * allow symlinking trees into /var/lib/container/, and treat
+ * them normally. */
+
+ if (fstatat(dfd, filename, &st, 0) < 0)
+ return -errno;
+
+ read_only =
+ (path && path_startswith(path, "/usr")) ||
+ (faccessat(dfd, filename, W_OK, AT_EACCESS) < 0 && errno == EROFS);
+
+ if (S_ISDIR(st.st_mode)) {
+
+ if (!ret)
+ return 1;
+
+ if (!pretty)
+ pretty = filename;
+
+ /* btrfs subvolumes have inode 256 */
+ if (st.st_ino == 256) {
+ _cleanup_close_ int fd = -1;
+ struct statfs sfs;
+
+ fd = openat(dfd, filename, O_CLOEXEC|O_NOCTTY|O_DIRECTORY);
+ if (fd < 0)
+ return -errno;
+
+ if (fstatfs(fd, &sfs) < 0)
+ return -errno;
+
+ if (F_TYPE_EQUAL(sfs.f_type, BTRFS_SUPER_MAGIC)) {
+ BtrfsSubvolInfo info;
+
+ /* It's a btrfs subvolume */
+
+ r = btrfs_subvol_get_info_fd(fd, &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;
+
+ return 1;
+ }
+ }
+
+ /* It's just a normal directory. */
+
+ r = image_new(IMAGE_DIRECTORY,
+ pretty,
+ path,
+ filename,
+ read_only,
+ 0,
+ 0,
+ ret);
+ if (r < 0)
+ return r;
+
+ return 1;
+
+ } else if (S_ISREG(st.st_mode) && endswith(filename, ".gpt")) {
+ usec_t crtime = 0;
+
+ /* It's a GPT block device */
+
+ if (!ret)
+ return 1;
+
+ fd_getcrtime_at(dfd, filename, &crtime, 0);
+
+ if (!pretty)
+ pretty = strndupa(filename, strlen(filename) - 4);
+
+ r = image_new(IMAGE_GPT,
+ pretty,
+ path,
+ filename,
+ !(st.st_mode & 0222) || read_only,
+ crtime,
+ timespec_load(&st.st_mtim),
+ ret);
+ if (r < 0)
+ return r;
+
+ return 1;
+ }
+
+ return 0;
+}
+
+int image_find(const char *name, Image **ret) {
+ const char *path;
+ int r;
+
+ assert(name);
+
+ /* There are no images with invalid names */
+ if (!image_name_is_valid(name))
+ return 0;
+
+ NULSTR_FOREACH(path, image_search_path) {
+ _cleanup_closedir_ DIR *d = NULL;
+
+ d = opendir(path);
+ if (!d) {
+ if (errno == ENOENT)
+ continue;
+
+ return -errno;
+ }
+
+ r = image_make(NULL, dirfd(d), path, name, ret);
+ if (r == 0 || r == -ENOENT) {
+ _cleanup_free_ char *gpt = NULL;
+
+ gpt = strappend(name, ".gpt");
+ if (!gpt)
+ return -ENOMEM;
+
+ r = image_make(NULL, dirfd(d), path, gpt, ret);
+ if (r == 0 || r == -ENOENT)
+ continue;
+ }
+ if (r < 0)
+ return r;
+
+ return 1;
+ }
+
+ if (streq(name, ".host"))
+ return image_make(".host", AT_FDCWD, NULL, "/", ret);
+
+ return 0;
+};
+
+int image_discover(Hashmap *h) {
+ const char *path;
+ int r;
+
+ assert(h);
+
+ NULSTR_FOREACH(path, image_search_path) {
+ _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;
+
+ if (!image_name_is_valid(de->d_name))
+ continue;
+
+ if (hashmap_contains(h, de->d_name))
+ continue;
+
+ r = image_make(NULL, dirfd(d), path, de->d_name, &image);
+ if (r == 0 || r == -ENOENT)
+ continue;
+ if (r < 0)
+ return r;
+
+ r = hashmap_put(h, image->name, image);
+ if (r < 0)
+ return r;
+
+ image = NULL;
+ }
+ }
+
+ if (!hashmap_contains(h, ".host")) {
+ _cleanup_(image_unrefp) Image *image = NULL;
+
+ r = image_make(".host", AT_FDCWD, NULL, "/", &image);
+ if (r < 0)
+ return r;
+
+ r = hashmap_put(h, image->name, image);
+ if (r < 0)
+ return r;
+
+ image = NULL;
+
+ }
+
+ return 0;
+}
+
+void image_hashmap_free(Hashmap *map) {
+ Image *i;
+
+ while ((i = hashmap_steal_first(map)))
+ image_unref(i);
+
+ hashmap_free(map);
+}
+
+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);