picnoir
/
Systemd
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

basic/cgroup-util: let cgroup_unified_flush() return the detected hierarchy 

This avoid the use of the global variable.

Also rename cgroup_unified_update() to cgroup_unified_cached() and
cgroup_unified_flush() to cgroup_unified() to better reflect their new roles.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2019-08-01 12:48:41 +02:00
parent 5a1c1b534f
commit d4d99bc6e4
7 changed files with 38 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

61
src/basic/cgroup-util.c
View File

@ -2526,20 +2526,20 @@ int cg_kernel_controllers(Set **ret) {
return 0;
}
static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN;
/* The hybrid mode was initially implemented in v232 and simply mounted cgroup2 on /sys/fs/cgroup/systemd. This
* unfortunately broke other tools (such as docker) which expected the v1 "name=systemd" hierarchy on
* /sys/fs/cgroup/systemd. From v233 and on, the hybrid mode mountnbs v2 on /sys/fs/cgroup/unified and maintains
* "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility with other tools.
/* The hybrid mode was initially implemented in v232 and simply mounted cgroup2 on
* /sys/fs/cgroup/systemd. This unfortunately broke other tools (such as docker) which expected the v1
* "name=systemd" hierarchy on /sys/fs/cgroup/systemd. From v233 and on, the hybrid mode mounts v2 on
* /sys/fs/cgroup/unified and maintains "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility
* with other tools.
*
* To keep live upgrade working, we detect and support v232 layout. When v232 layout is detected, to keep cgroup v2
* process management but disable the compat dual layout, we return %true on
* cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) and %false on cg_hybrid_unified().
* To keep live upgrade working, we detect and support v232 layout. When v232 layout is detected, to keep
* cgroup v2 process management but disable the compat dual layout, we return true on
* cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER) and false on cg_hybrid_unified().
*/
static thread_local bool unified_systemd_v232;
static int cg_unified_update(void) {
int cg_unified_cached(bool flush) {
static thread_local CGroupUnified unified_cache = CGROUP_UNIFIED_UNKNOWN;
struct statfs fs;
@ -2548,8 +2548,10 @@ static int cg_unified_update(void) {
* have any other trouble determining if the unified hierarchy
* is supported. */
if (unified_cache >= CGROUP_UNIFIED_NONE)
return 0;
if (flush)
unified_cache = CGROUP_UNIFIED_UNKNOWN;
else if (unified_cache >= CGROUP_UNIFIED_NONE)
return unified_cache;
if (statfs("/sys/fs/cgroup/", &fs) < 0)
return log_debug_errno(errno, "statfs(\"/sys/fs/cgroup/\") failed: %m");
@ -2585,20 +2587,20 @@ static int cg_unified_update(void) {
"Unknown filesystem type %llx mounted on /sys/fs/cgroup.",
(unsigned long long)fs.f_type);
return 0;
return unified_cache;
}
int cg_unified_controller(const char *controller) {
int r;
r = cg_unified_update();
r = cg_unified_cached(false);
if (r < 0)
return r;
if (unified_cache == CGROUP_UNIFIED_NONE)
if (r == CGROUP_UNIFIED_NONE)
return false;
if (unified_cache >= CGROUP_UNIFIED_ALL)
if (r >= CGROUP_UNIFIED_ALL)
return true;
return streq_ptr(controller, SYSTEMD_CGROUP_CONTROLLER);
@ -2607,27 +2609,21 @@ int cg_unified_controller(const char *controller) {
int cg_all_unified(void) {
int r;
r = cg_unified_update();
r = cg_unified_cached(false);
if (r < 0)
return r;
return unified_cache >= CGROUP_UNIFIED_ALL;
return r >= CGROUP_UNIFIED_ALL;
}
int cg_hybrid_unified(void) {
int r;
r = cg_unified_update();
r = cg_unified_cached(false);
if (r < 0)
return r;
return unified_cache == CGROUP_UNIFIED_SYSTEMD && !unified_systemd_v232;
}
int cg_unified_flush(void) {
unified_cache = CGROUP_UNIFIED_UNKNOWN;
return cg_unified_update();
return r == CGROUP_UNIFIED_SYSTEMD && !unified_systemd_v232;
}
int cg_enable_everywhere(
@ -2740,10 +2736,10 @@ int cg_enable_everywhere(
bool cg_is_unified_wanted(void) {
static thread_local int wanted = -1;
int r;
bool b;
const bool is_default = DEFAULT_HIERARCHY == CGROUP_UNIFIED_ALL;
_cleanup_free_ char *c = NULL;
int r;
/* If we have a cached value, return that. */
if (wanted >= 0)
@ -2751,8 +2747,9 @@ bool cg_is_unified_wanted(void) {
/* If the hierarchy is already mounted, then follow whatever
* was chosen for it. */
if (cg_unified_flush() >= 0)
return (wanted = unified_cache >= CGROUP_UNIFIED_ALL);
r = cg_unified_cached(true);
if (r >= 0)
return (wanted = r >= CGROUP_UNIFIED_ALL);
/* If we were explicitly passed systemd.unified_cgroup_hierarchy,
* respect that. */
@ -2777,8 +2774,7 @@ bool cg_is_legacy_wanted(void) {
return wanted;
/* Check if we have cgroup v2 already mounted. */
if (cg_unified_flush() >= 0 &&
unified_cache == CGROUP_UNIFIED_ALL)
if (cg_unified_cached(true) == CGROUP_UNIFIED_ALL)
return (wanted = false);
/* Otherwise, assume that at least partial legacy is wanted,
@ -2801,8 +2797,7 @@ bool cg_is_hybrid_wanted(void) {
/* If the hierarchy is already mounted, then follow whatever
* was chosen for it. */
if (cg_unified_flush() >= 0 &&
unified_cache == CGROUP_UNIFIED_ALL)
if (cg_unified_cached(true) == CGROUP_UNIFIED_ALL)
return (wanted = false);
/* Otherwise, let's see what the kernel command line has to say.

5
src/basic/cgroup-util.h
View File

@ -258,7 +258,10 @@ bool cg_ns_supported(void);
int cg_all_unified(void);
int cg_hybrid_unified(void);
int cg_unified_controller(const char *controller);
int cg_unified_flush(void);
int cg_unified_cached(bool flush);
static inline int cg_unified(void) {
return cg_unified_cached(true);
}
bool cg_is_unified_wanted(void);
bool cg_is_legacy_wanted(void);

2
src/core/cgroup.c
View File

@ -2839,7 +2839,7 @@ int manager_setup_cgroup(Manager *m) {
if (r < 0)
return log_error_errno(r, "Cannot find cgroup mount point: %m");
r = cg_unified_flush();
r = cg_unified();
if (r < 0)
return log_error_errno(r, "Couldn't determine if we are running in the unified hierarchy: %m");

2
src/libsystemd/sd-bus/test-bus-creds.c
View File

@ -13,7 +13,7 @@ int main(int argc, char *argv[]) {
test_setup_logging(LOG_DEBUG);
if (cg_unified_flush() == -ENOMEDIUM)
if (cg_unified() == -ENOMEDIUM)
return log_tests_skipped("/sys/fs/cgroup/ not available");
r = sd_bus_creds_new_from_pid(&creds, 0, _SD_BUS_CREDS_ALL);

2
src/nspawn/nspawn.c
View File

@ -4720,7 +4720,7 @@ static int run(int argc, char *argv[]) {
if (r < 0)
goto finish;
r = cg_unified_flush();
r = cg_unified();
if (r < 0) {
log_error_errno(r, "Failed to determine whether the unified cgroups hierarchy is used: %m");
goto finish;

4
src/test/test-cgroup-util.c
View File

@ -385,12 +385,12 @@ static void test_is_wanted(void) {
static void test_cg_tests(void) {
int all, hybrid, systemd, r;
r = cg_unified_flush();
r = cg_unified();
if (r == -ENOMEDIUM) {
log_notice_errno(r, "Skipping cg hierarchy tests: %m");
return;
}
assert_se(r == 0);
assert_se(r >= 0);
all = cg_all_unified();
assert_se(IN_SET(all, 0, 1));

2
src/test/test-condition.c
View File

@ -124,7 +124,7 @@ static void test_condition_test_control_group_controller(void) {
_cleanup_free_ char *controller_name = NULL;
int r;
r = cg_unified_flush();
r = cg_unified();
if (r < 0) {
log_notice_errno(r, "Skipping ConditionControlGroupController tests: %m");
return;