Skip to content

L
lxc
Commit bebc48f1 by Christian Brauner
Options

Merge pull request #956 from hallyn/2016-04-08/cgnfs-defer

cgfsng: defer to cgfs if needed subsystems are not available
parents 32036de0 457ca9aa
Showing with 78 additions and 118 deletions
src/lxc/cgfsng.c
......@@ -72,10 +72,6 @@ struct hierarchy {
/*
* The cgroup data which is attached to the lxc_handler.
* @hierarchies - a NULL-terminated array of struct hierarchy, one per
* hierarchy. No duplicates. First sufficient, writeable mounted
* hierarchy wins
* @cgroup_use - a copy of the lxc.cgroup.use
* @cgroup_pattern - a copy of the lxc.cgroup.pattern
* @container_cgroup - if not null, the cgroup which was created for
* the container. For each hierarchy, it is created under the
......@@ -84,13 +80,23 @@ struct hierarchy {
* @name - the container name
*/
struct cgfsng_handler_data {
struct hierarchy **hierarchies;
char *cgroup_use;
char *cgroup_pattern;
char *container_cgroup; // cgroup we created for the container
char *name; // container name
};
/*
* @hierarchies - a NULL-terminated array of struct hierarchy, one per
* hierarchy. No duplicates. First sufficient, writeable mounted
* hierarchy wins
*/
struct hierarchy **hierarchies;
/*
* @cgroup_use - a copy of the lxc.cgroup.use
*/
char *cgroup_use;
static void free_string_list(char **clist)
{
if (clist) {
......@@ -218,25 +224,8 @@ static void must_append_controller(char **klist, char **nlist, char ***clist, ch
(*clist)[newentry] = copy;
}
static void free_hierarchies(struct hierarchy **hlist)
{
if (hlist) {
int i;
for (i = 0; hlist[i]; i++) {
free(hlist[i]->mountpoint);
free(hlist[i]->base_cgroup);
free(hlist[i]->fullcgpath);
free_string_list(hlist[i]->controllers);
}
free(hlist);
}
}
static void free_handler_data(struct cgfsng_handler_data *d)
{
free_hierarchies(d->hierarchies);
free(d->cgroup_use);
free(d->cgroup_pattern);
free(d->container_cgroup);
free(d->name);
......@@ -247,15 +236,15 @@ static void free_handler_data(struct cgfsng_handler_data *d)
* Given a handler's cgroup data, return the struct hierarchy for the
* controller @c, or NULL if there is none.
*/
struct hierarchy *get_hierarchy(struct cgfsng_handler_data *d, const char *c)
struct hierarchy *get_hierarchy(const char *c)
{
int i;
if (!d || !d->hierarchies)
if (!hierarchies)
return NULL;
for (i = 0; d->hierarchies[i]; i++) {
if (string_in_list(d->hierarchies[i]->controllers, c))
return d->hierarchies[i];
for (i = 0; hierarchies[i]; i++) {
if (string_in_list(hierarchies[i]->controllers, c))
return hierarchies[i];
}
return NULL;
}
......@@ -422,10 +411,10 @@ static bool controller_found(struct hierarchy **hlist, char *entry)
* found. The required list is systemd, freezer, and anything in
* lxc.cgroup.use.
*/
static bool all_controllers_found(struct cgfsng_handler_data *d)
static bool all_controllers_found(void)
{
char *p, *saveptr = NULL;
struct hierarchy ** hlist = d->hierarchies;
struct hierarchy ** hlist = hierarchies;
if (!controller_found(hlist, "name=systemd")) {
ERROR("no systemd controller mountpoint found");
......@@ -436,9 +425,9 @@ static bool all_controllers_found(struct cgfsng_handler_data *d)
return false;
}
if (!d->cgroup_use)
if (!cgroup_use)
return true;
for (p = strtok_r(d->cgroup_use, ",", &saveptr); p;
for (p = strtok_r(cgroup_use, ",", &saveptr); p;
p = strtok_r(NULL, ",", &saveptr)) {
if (!controller_found(hlist, p)) {
ERROR("no %s controller mountpoint found", p);
......@@ -508,8 +497,7 @@ static bool is_cgroupfs(char *line)
}
/* Add a controller to our list of hierarchies */
static void add_controller(struct cgfsng_handler_data *d, char **clist,
char *mountpoint, char *base_cgroup)
static void add_controller(char **clist, char *mountpoint, char *base_cgroup)
{
struct hierarchy *new;
int newentry;
......@@ -520,8 +508,8 @@ static void add_controller(struct cgfsng_handler_data *d, char **clist,
new->base_cgroup = base_cgroup;
new->fullcgpath = NULL;
newentry = append_null_to_list((void ***)&d->hierarchies);
d->hierarchies[newentry] = new;
newentry = append_null_to_list((void ***)&hierarchies);
hierarchies[newentry] = new;
}
/*
......@@ -732,16 +720,16 @@ static void print_init_debuginfo(struct cgfsng_handler_data *d)
printf("Cgroup information:\n");
printf(" container name: %s\n", d->name);
printf(" lxc.cgroup.use: %s\n", d->cgroup_use ? d->cgroup_use : "(none)");
printf(" lxc.cgroup.use: %s\n", cgroup_use ? cgroup_use : "(none)");
printf(" lxc.cgroup.pattern: %s\n", d->cgroup_pattern);
printf(" cgroup: %s\n", d->container_cgroup ? d->container_cgroup : "(none)");
if (!d->hierarchies) {
if (!hierarchies) {
printf(" No hierarchies found.\n");
return;
}
printf(" Hierarchies:\n");
for (i = 0; d->hierarchies[i]; i++) {
struct hierarchy *h = d->hierarchies[i];
for (i = 0; hierarchies[i]; i++) {
struct hierarchy *h = hierarchies[i];
int j;
printf(" %d: base_cgroup %s\n", i, h->base_cgroup);
printf(" mountpoint %s\n", h->mountpoint);
......@@ -769,7 +757,7 @@ static void print_basecg_debuginfo(char *basecginfo, char **klist, char **nlist)
* At startup, parse_hierarchies finds all the info we need about
* cgroup mountpoints and current cgroups, and stores it in @d.
*/
static bool parse_hierarchies(struct cgfsng_handler_data *d)
static bool parse_hierarchies(void)
{
FILE *f;
char * line = NULL, *basecginfo;
......@@ -808,7 +796,7 @@ static bool parse_hierarchies(struct cgfsng_handler_data *d)
if (!controller_list)
continue;
if (controller_list_is_dup(d->hierarchies, controller_list)) {
if (controller_list_is_dup(hierarchies, controller_list)) {
free(controller_list);
continue;
}
......@@ -835,7 +823,7 @@ static bool parse_hierarchies(struct cgfsng_handler_data *d)
free(base_cgroup);
continue;
}
add_controller(d, controller_list, mountpoint, base_cgroup);
add_controller(controller_list, mountpoint, base_cgroup);
}
free_string_list(klist);
......@@ -846,35 +834,39 @@ static bool parse_hierarchies(struct cgfsng_handler_data *d)
fclose(f);
free(line);
print_init_debuginfo(d);
/* verify that all controllers in cgroup.use and all crucial
* controllers are accounted for
*/
if (!all_controllers_found(d))
if (!all_controllers_found())
return false;
return true;
}
static bool collect_hierarchy_info(void)
{
const char *tmp;
errno = 0;
tmp = lxc_global_config_value("lxc.cgroup.use");
if (!cgroup_use && errno != 0) { // lxc.cgroup.use can be NULL
SYSERROR("cgfsng: error reading list of cgroups to use");
return false;
}
cgroup_use = must_copy_string(tmp);
return parse_hierarchies();
}
static void *cgfsng_init(const char *name)
{
struct cgfsng_handler_data *d;
const char *cgroup_use, *cgroup_pattern;
const char *cgroup_pattern;
d = must_alloc(sizeof(*d));
memset(d, 0, sizeof(*d));
d->name = must_copy_string(name);
errno = 0;
cgroup_use = lxc_global_config_value("lxc.cgroup.use");
if (!cgroup_use && errno != 0) { // lxc.cgroup.use can be NULL
SYSERROR("Error reading list of cgroups to use");
goto out_free;
}
d->cgroup_use = must_copy_string(cgroup_use);
cgroup_pattern = lxc_global_config_value("lxc.cgroup.pattern");
if (!cgroup_pattern) { // lxc.cgroup.pattern is only NULL on error
ERROR("Error getting cgroup pattern");
......@@ -882,9 +874,6 @@ static void *cgfsng_init(const char *name)
}
d->cgroup_pattern = must_copy_string(cgroup_pattern);
if (!parse_hierarchies(d))
goto out_free;
print_init_debuginfo(d);
return d;
......@@ -1006,10 +995,10 @@ static void cgfsng_destroy(void *hdata, struct lxc_conf *conf)
if (!d)
return;
if (d->container_cgroup && d->hierarchies) {
if (d->container_cgroup && hierarchies) {
int i;
for (i = 0; d->hierarchies[i]; i++) {
struct hierarchy *h = d->hierarchies[i];
for (i = 0; hierarchies[i]; i++) {
struct hierarchy *h = hierarchies[i];
if (h->fullcgpath) {
recursive_destroy(h->fullcgpath, conf);
free(h->fullcgpath);
......@@ -1023,6 +1012,8 @@ static void cgfsng_destroy(void *hdata, struct lxc_conf *conf)
struct cgroup_ops *cgfsng_ops_init(void)
{
if (!collect_hierarchy_info())
return NULL;
return &cgfsng_ops;
}
......@@ -1080,14 +1071,14 @@ again:
}
if (idx)
snprintf(offset, 5, "-%d", idx);
for (i = 0; d->hierarchies[i]; i++) {
if (!create_path_for_hierarchy(d->hierarchies[i], cgname)) {
for (i = 0; hierarchies[i]; i++) {
if (!create_path_for_hierarchy(hierarchies[i], cgname)) {
int j;
SYSERROR("Failed to create %s: %s", d->hierarchies[i]->fullcgpath, strerror(errno));
free(d->hierarchies[i]->fullcgpath);
d->hierarchies[i]->fullcgpath = NULL;
SYSERROR("Failed to create %s: %s", hierarchies[i]->fullcgpath, strerror(errno));
free(hierarchies[i]->fullcgpath);
hierarchies[i]->fullcgpath = NULL;
for (j = 0; j < i; j++)
remove_path_for_hierarchy(d->hierarchies[j], cgname);
remove_path_for_hierarchy(hierarchies[j], cgname);
idx++;
goto again;
}
......@@ -1110,7 +1101,6 @@ static const char *cgfsng_canonical_path(void *hdata)
static bool cgfsng_enter(void *hdata, pid_t pid)
{
struct cgfsng_handler_data *d = hdata;
char pidstr[25];
int i, len;
......@@ -1118,8 +1108,8 @@ static bool cgfsng_enter(void *hdata, pid_t pid)
if (len < 0 || len > 25)
return false;
for (i = 0; d->hierarchies[i]; i++) {
char *fullpath = must_make_path(d->hierarchies[i]->fullcgpath,
for (i = 0; hierarchies[i]; i++) {
char *fullpath = must_make_path(hierarchies[i]->fullcgpath,
"cgroup.procs", NULL);
if (lxc_write_to_file(fullpath, pidstr, len, false) != 0) {
SYSERROR("Failed to enter %s", fullpath);
......@@ -1148,7 +1138,6 @@ struct chown_data {
static int chown_cgroup_wrapper(void *data)
{
struct chown_data *arg = data;
struct cgfsng_handler_data *d = arg->d;
uid_t destuid;
int i;
......@@ -1161,8 +1150,8 @@ static int chown_cgroup_wrapper(void *data)
destuid = get_ns_uid(arg->origuid);
for (i = 0; d->hierarchies[i]; i++) {
char *fullpath, *path = d->hierarchies[i]->fullcgpath;
for (i = 0; hierarchies[i]; i++) {
char *fullpath, *path = hierarchies[i]->fullcgpath;
if (chown(path, destuid, 0) < 0) {
SYSERROR("Error chowning %s to %d", path, (int) destuid);
......@@ -1334,9 +1323,9 @@ static bool cgfsng_mount(void *hdata, const char *root, int type)
root) < 0)
goto bad;
for (i = 0; d->hierarchies[i]; i++) {
for (i = 0; hierarchies[i]; i++) {
char *controllerpath, *path2;
struct hierarchy *h = d->hierarchies[i];
struct hierarchy *h = hierarchies[i];
char *controller = strrchr(h->mountpoint, '/');
int r;
......@@ -1431,9 +1420,9 @@ static int cgfsng_nrtasks(void *hdata) {
char *path;
int count;
if (!d || !d->container_cgroup || !d->hierarchies)
if (!d || !d->container_cgroup || !hierarchies)
return -1;
path = must_make_path(d->hierarchies[0]->fullcgpath, NULL);
path = must_make_path(hierarchies[0]->fullcgpath, NULL);
count = recursive_count_nrtasks(path);
free(path);
return count;
......@@ -1455,9 +1444,9 @@ static bool cgfsng_escape()
return false;
}
for (i = 0; d->hierarchies[i]; i++) {
char *fullpath = must_make_path(d->hierarchies[i]->mountpoint,
d->hierarchies[i]->base_cgroup,
for (i = 0; hierarchies[i]; i++) {
char *fullpath = must_make_path(hierarchies[i]->mountpoint,
hierarchies[i]->base_cgroup,
"cgroup.procs", NULL);
if (lxc_write_to_file(fullpath, "0", 2, false) != 0) {
SYSERROR("Failed to escape to %s", fullpath);
......@@ -1478,11 +1467,10 @@ out:
static bool cgfsng_unfreeze(void *hdata)
{
struct cgfsng_handler_data *d = hdata;
char *fullpath;
struct hierarchy *h = get_hierarchy(d, "freezer");
struct hierarchy *h = get_hierarchy("freezer");
if (!d || !h)
if (!h)
return false;
fullpath = must_make_path(h->fullcgpath, "freezer.state", NULL);
if (lxc_write_to_file(fullpath, THAWED, THAWED_LEN, false) != 0) {
......@@ -1495,12 +1483,7 @@ static bool cgfsng_unfreeze(void *hdata)
static const char *cgfsng_get_cgroup(void *hdata, const char *subsystem)
{
struct cgfsng_handler_data *d = hdata;
struct hierarchy *h;
if (!d)
return NULL;
h = get_hierarchy(d, subsystem);
struct hierarchy *h = get_hierarchy(subsystem);
if (!h)
return NULL;
......@@ -1527,7 +1510,6 @@ static char *build_full_cgpath_from_monitorpath(struct hierarchy *h,
static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
{
struct cgfsng_handler_data *d;
char pidstr[25];
int i, len;
......@@ -1535,13 +1517,9 @@ static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
if (len < 0 || len > 25)
return false;
d = cgfsng_init(name);
if (!d)
return false;
for (i = 0; d->hierarchies[i]; i++) {
for (i = 0; hierarchies[i]; i++) {
char *path, *fullpath;
struct hierarchy *h = d->hierarchies[i];
struct hierarchy *h = hierarchies[i];
path = lxc_cmd_get_cgroup_path(name, lxcpath, h->controllers[0]);
if (!path) // not running
......@@ -1552,13 +1530,11 @@ static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
if (lxc_write_to_file(fullpath, pidstr, len, false) != 0) {
SYSERROR("Failed to attach %d to %s", (int)pid, fullpath);
free(fullpath);
free_handler_data(d);
return false;
}
free(fullpath);
}
free_handler_data(d);
return true;
}
......@@ -1570,7 +1546,6 @@ static bool cgfsng_attach(const char *name, const char *lxcpath, pid_t pid)
static int cgfsng_get(const char *filename, char *value, size_t len, const char *name, const char *lxcpath)
{
char *subsystem, *p, *path;
struct cgfsng_handler_data *d;
struct hierarchy *h;
int ret = -1;
......@@ -1583,20 +1558,13 @@ static int cgfsng_get(const char *filename, char *value, size_t len, const char
if (!path) // not running
return -1;
d = cgfsng_init(name);
if (!d) {
free(path);
return false;
}
h = get_hierarchy(d, subsystem);
h = get_hierarchy(subsystem);
if (h) {
char *fullpath = build_full_cgpath_from_monitorpath(h, path, filename);
ret = lxc_read_from_file(fullpath, value, len);
free(fullpath);
}
free_handler_data(d);
free(path);
return ret;
......@@ -1610,7 +1578,6 @@ static int cgfsng_get(const char *filename, char *value, size_t len, const char
static int cgfsng_set(const char *filename, const char *value, const char *name, const char *lxcpath)
{
char *subsystem, *p, *path;
struct cgfsng_handler_data *d;
struct hierarchy *h;
int ret = -1;
......@@ -1623,20 +1590,13 @@ static int cgfsng_set(const char *filename, const char *value, const char *name,
if (!path) // not running
return -1;
d = cgfsng_init(name);
if (!d) {
free(path);
return false;
}
h = get_hierarchy(d, subsystem);
h = get_hierarchy(subsystem);
if (h) {
char *fullpath = build_full_cgpath_from_monitorpath(h, path, filename);
ret = lxc_write_to_file(fullpath, value, strlen(value), false);
free(fullpath);
}
free_handler_data(d);
free(path);
return ret;
......@@ -1657,7 +1617,7 @@ static int lxc_cgroup_set_data(const char *filename, const char *value, struct c
if ((p = strchr(subsystem, '.')) != NULL)
*p = '\0';
h = get_hierarchy(d, subsystem);
h = get_hierarchy(subsystem);
if (h) {
char *fullpath = must_make_path(h->fullcgpath, filename, NULL);
ret = lxc_write_to_file(fullpath, value, strlen(value), false);
......@@ -1685,7 +1645,7 @@ static bool cgfsng_setup_limits(void *hdata, struct lxc_list *cgroup_settings,
}
if (do_devices) {
h = get_hierarchy(d, "devices");
h = get_hierarchy("devices");
if (!h) {
ERROR("No devices cgroup setup for %s", d->name);
return false;
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment