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path: root/src/nspawn/nspawn-cgroup.c
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Diffstat (limited to 'src/nspawn/nspawn-cgroup.c')
-rw-r--r--src/nspawn/nspawn-cgroup.c44
1 files changed, 28 insertions, 16 deletions
diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c
index df0044990a..b64475bcb4 100644
--- a/src/nspawn/nspawn-cgroup.c
+++ b/src/nspawn/nspawn-cgroup.c
@@ -65,11 +65,11 @@ static int chown_cgroup(pid_t pid, uid_t uid_shift) {
r = cg_pid_get_path(NULL, pid, &path);
if (r < 0)
- return log_error_errno(r, "Failed to get container cgroup path: %m");
+ return log_error_errno(r, "Failed to get host cgroup of the container: %m");
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, path, NULL, &fs);
if (r < 0)
- return log_error_errno(r, "Failed to get file system path for container cgroup: %m");
+ return log_error_errno(r, "Failed to get host file system path for container cgroup: %m");
r = chown_cgroup_path(fs, uid_shift);
if (r < 0)
@@ -82,12 +82,14 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner
_cleanup_free_ char *cgroup = NULL;
char mountpoint[] = "/tmp/containerXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1];
bool undo_mount = false;
- const char *fn;
+ const char *fn, *inner_hier;
int r;
+#define LOG_PFIX "PID " PID_FMT ": sync host cgroup -> container cgroup"
+
unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
if (unified < 0)
- return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
+ return log_error_errno(unified, LOG_PFIX ": failed to determine host cgroup version: %m", pid);
if ((outer_cgver >= CGROUP_UNIFIED_SYSTEMD) == (inner_cgver >= CGROUP_UNIFIED_SYSTEMD))
return 0;
@@ -99,20 +101,27 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
if (r < 0)
- return log_error_errno(r, "Failed to get control group of " PID_FMT ": %m", pid);
+ return log_error_errno(r, LOG_PFIX ": failed to determine host cgroup: %m", pid);
/* In order to access the container's hierarchy we need to mount it */
if (!mkdtemp(mountpoint))
- return log_error_errno(errno, "Failed to generate temporary mount point for container hierarchy: %m");
+ return log_error_errno(errno, LOG_PFIX ": failed to create temporary mount point for container cgroup hierarchy: %m", pid);
if (outer_cgver >= CGROUP_UNIFIED_SYSTEMD) {
+ /* host: v2 ; container: v1 */
+ inner_hier = "?:name=systemd";
r = mount_verbose(LOG_ERR, "cgroup", mountpoint, "cgroup",
MS_NOSUID|MS_NOEXEC|MS_NODEV, "none,name=systemd,xattr");
- else
+ } else {
+ /* host: v1 ; container: v2 */
+ inner_hier = "0:";
r = mount_verbose(LOG_ERR, "cgroup", mountpoint, "cgroup2",
MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL);
- if (r < 0)
+ }
+ if (r < 0) {
+ log_error(LOG_PFIX ": failed to mount container cgroup hierarchy", pid);
goto finish;
+ }
undo_mount = true;
@@ -128,17 +137,20 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner
sprintf(pid_string, PID_FMT, pid);
r = write_string_file(fn, pid_string, 0);
if (r < 0) {
- log_error_errno(r, "Failed to move process: %m");
+ log_error_errno(r, LOG_PFIX ": failed to move process to `%s:%s': %m", pid, inner_hier, cgroup);
goto finish;
}
fn = strjoina(mountpoint, cgroup);
r = chown_cgroup_path(fn, uid_shift);
if (r < 0)
- log_error_errno(r, "Failed to chown() cgroup %s: %m", fn);
+ log_error_errno(r, LOG_PFIX ": chown(path=\"%s\", uid=" UID_FMT "): %m", pid, fn, uid_shift);
finish:
- if (undo_mount)
- (void) umount_verbose(mountpoint);
+ if (undo_mount) {
+ r = umount_verbose(mountpoint);
+ if (r < 0)
+ log_error_errno(r, LOG_PFIX ": umount(\"%s\"): %m", pid, mountpoint);
+ }
(void) rmdir(mountpoint);
return r;
@@ -161,21 +173,21 @@ static int create_subcgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified
r = cg_mask_supported(&supported);
if (r < 0)
- return log_error_errno(r, "Failed to determine supported controllers: %m");
+ return log_error_errno(r, "Failed to create host subcgroup: Failed to determine supported controllers: %m");
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
if (r < 0)
- return log_error_errno(r, "Failed to get our control group: %m");
+ return log_error_errno(r, "Failed to create host subcgroup: Failed to get our control group: %m");
child = strjoina(cgroup, "/payload");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid);
if (r < 0)
- return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
+ return log_error_errno(r, "Failed to create host subcgroup: Failed to create %s subcgroup: %m", child);
child = strjoina(cgroup, "/supervisor");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0);
if (r < 0)
- return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
+ return log_error_errno(r, "Failed to create host subcgroup: Failed to create %s subcgroup: %m", child);
/* Try to enable as many controllers as possible for the new payload. */
(void) cg_enable_everywhere(supported, supported, cgroup);