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-rw-r--r--src/nspawn/nspawn-cgroup.c112
-rw-r--r--src/nspawn/nspawn-cgroup.h2
-rw-r--r--src/nspawn/nspawn.c2
3 files changed, 76 insertions, 40 deletions
diff --git a/src/nspawn/nspawn-cgroup.c b/src/nspawn/nspawn-cgroup.c
index b64475bcb4..795ad5f4ae 100644
--- a/src/nspawn/nspawn-cgroup.c
+++ b/src/nspawn/nspawn-cgroup.c
@@ -25,7 +25,9 @@
#include "fs-util.h"
#include "mkdir.h"
#include "mount-util.h"
+#include "parse-util.h"
#include "path-util.h"
+#include "process-util.h"
#include "rm-rf.h"
#include "string-util.h"
#include "strv.h"
@@ -59,25 +61,6 @@ static int chown_cgroup_path(const char *path, uid_t uid_shift) {
return 0;
}
-static int chown_cgroup(pid_t pid, uid_t uid_shift) {
- _cleanup_free_ char *path = NULL, *fs = NULL;
- int r;
-
- r = cg_pid_get_path(NULL, pid, &path);
- if (r < 0)
- 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 host file system path for container cgroup: %m");
-
- r = chown_cgroup_path(fs, uid_shift);
- if (r < 0)
- return log_error_errno(r, "Failed to chown() cgroup %s: %m", fs);
-
- return 0;
-}
-
static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner_cgver, uid_t uid_shift) {
_cleanup_free_ char *cgroup = NULL;
char mountpoint[] = "/tmp/containerXXXXXX", pid_string[DECIMAL_STR_MAX(pid) + 1];
@@ -87,13 +70,6 @@ static int sync_cgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner
#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, LOG_PFIX ": failed to determine host cgroup version: %m", pid);
-
- if ((outer_cgver >= CGROUP_UNIFIED_SYSTEMD) == (inner_cgver >= CGROUP_UNIFIED_SYSTEMD))
- return 0;
-
/* When the host uses the legacy cgroup setup, but the
* container shall use the unified hierarchy, let's make sure
* we copy the path from the name=systemd hierarchy into the
@@ -168,9 +144,6 @@ static int create_subcgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified
* did not create a scope unit for the container move us and
* the container into two separate subcgroups. */
- if (inner_cgver == CGROUP_UNIFIED_NONE || outer_cgver == CGROUP_UNIFIED_NONE)
- return 0;
-
r = cg_mask_supported(&supported);
if (r < 0)
return log_error_errno(r, "Failed to create host subcgroup: Failed to determine supported controllers: %m");
@@ -194,22 +167,85 @@ static int create_subcgroup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified
return 0;
}
-int cgroup_setup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner_cgver, uid_t uid_shift, bool keep_unit) {
- int r;
+static int cgpath_count_procs(const char *cgpath, Set **ret_pids) {
+ char line[LINE_MAX];
+ _cleanup_set_free_ Set *pid_set = NULL;
+ _cleanup_fclose_ FILE *procs = NULL;
- r = sync_cgroup(pid, outer_cgver, inner_cgver, uid_shift);
- if (r < 0)
- return r;
+ pid_set = set_new(NULL);
+ if (!pid_set)
+ return -ENOMEM;
+
+ procs = fopen(prefix_roota(cgpath, "cgroup.procs"), "re");
+ if (!procs)
+ return -errno;
- if (keep_unit) {
- r = create_subcgroup(pid, outer_cgver, inner_cgver);
+ FOREACH_LINE(line, procs, return -errno) {
+ int r;
+ pid_t pid;
+
+ truncate_nl(line);
+ r = parse_pid(line, &pid);
if (r < 0)
return r;
+ set_put(pid_set, PID_TO_PTR(pid));
}
- r = chown_cgroup(pid, uid_shift);
+ if (ret_pids) {
+ *ret_pids = pid_set;
+ pid_set = NULL;
+ }
+ return 0;
+}
+
+int cgroup_setup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner_cgver, uid_t uid_shift) {
+ _cleanup_free_ char *cgpath = NULL, *cgroup = NULL;
+ _cleanup_set_free_ Set *peers = NULL;
+ int r;
+
+ if ((outer_cgver >= CGROUP_UNIFIED_SYSTEMD) != (inner_cgver >= CGROUP_UNIFIED_SYSTEMD)) {
+ /* sync the name=systemd hierarchy with the unified hierarchy */
+ r = sync_cgroup(pid, outer_cgver, inner_cgver, uid_shift);
+ if (r < 0)
+ return r;
+ }
+
+ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
if (r < 0)
- return r;
+ return log_error_errno(r, "Failed to get host cgroup of the container: %m");
+
+ r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, cgroup, NULL, &cgpath);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get host file system path for container cgroup: %m");
+
+ r = cgpath_count_procs(cgpath, &peers);
+ if (r < 0)
+ return log_error_errno(r, "Unable to count the processes in the container's cgroup: %m");
+
+ /* This applies only to the unified hierarchy */
+ if (outer_cgver >= CGROUP_UNIFIED_SYSTEMD && inner_cgver >= CGROUP_UNIFIED_SYSTEMD) {
+ if (set_size(peers) == 2 && set_contains(peers, PID_TO_PTR(getpid()))) {
+ char *tmp;
+
+ r = create_subcgroup(pid, outer_cgver, inner_cgver);
+ if (r < 0)
+ return r;
+
+ set_remove(peers, PID_TO_PTR(getpid()));
+ tmp = strappend(cgpath, "/payload");
+ if (!tmp)
+ return log_oom();
+ cgpath = tmp;
+ }
+ }
+
+ /* This applies only to the name=systemd/unified hierarchy, but IMO it should apply to all
+ * hierarchies. */
+ if (uid_shift != UID_INVALID && set_size(peers) == 1) {
+ r = chown_cgroup_path(cgpath, uid_shift);
+ if (r < 0)
+ return log_error_errno(r, "Failed to chown() cgroup %s: %m", cgpath);
+ }
return 0;
}
diff --git a/src/nspawn/nspawn-cgroup.h b/src/nspawn/nspawn-cgroup.h
index b141c4e5d3..e677766726 100644
--- a/src/nspawn/nspawn-cgroup.h
+++ b/src/nspawn/nspawn-cgroup.h
@@ -24,7 +24,7 @@
#include "cgroup-util.h"
-int cgroup_setup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner_cgver, uid_t uid_shift, bool keep_unit);
+int cgroup_setup(pid_t pid, CGroupUnified outer_cgver, CGroupUnified inner_cgver, uid_t uid_shift);
int mount_cgroups(const char *dest, CGroupUnified outer_cgver, CGroupUnified inner_cgver, bool userns, uid_t uid_shift, uid_t uid_range, const char *selinux_apifs_context, bool use_cgns);
int mount_systemd_cgroup_writable(const char *dest, CGroupUnified inner_cgver);
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index 33863b01b3..caf8ba3868 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -3875,7 +3875,7 @@ static int run(int master,
return r;
}
- r = cgroup_setup(*pid, outer_cgver, arg_unified_cgroup_hierarchy, arg_uid_shift, arg_keep_unit);
+ r = cgroup_setup(*pid, outer_cgver, arg_unified_cgroup_hierarchy, arg_uid_shift);
if (r < 0)
return r;