[lxc-devel] [lxc/master] cgfsng: defer to cgfs if needed subsystems are not available
hallyn on Github
lxc-bot at linuxcontainers.org
Fri Apr 8 21:32:41 UTC 2016
A non-text attachment was scrubbed...
Name: not available
Type: text/x-mailbox
Size: 669 bytes
Desc: not available
URL: <http://lists.linuxcontainers.org/pipermail/lxc-devel/attachments/20160408/5d807f50/attachment.bin>
-------------- next part --------------
From 457ca9aa85c3682c2746f593090df2e1e6664d34 Mon Sep 17 00:00:00 2001
From: Serge Hallyn <serge.hallyn at ubuntu.com>
Date: Fri, 8 Apr 2016 16:18:04 -0500
Subject: [PATCH] cgfsng: defer to cgfs if needed subsystems are not available
This requires us to check that at cgfsng_ops_init, rather than
cgfs_init. Cache the hierarchy and cgroup.use info globally
rather than putting it into the per-container info, as cgmanager
does. This is ok as both cgroup.use and the list of usable
hierarchies are in fact global to a lxc run.
Closes #952
Signed-off-by: Serge Hallyn <serge.hallyn at ubuntu.com>
---
src/lxc/cgfsng.c | 196 ++++++++++++++++++++++---------------------------------
1 file changed, 78 insertions(+), 118 deletions(-)
diff --git a/src/lxc/cgfsng.c b/src/lxc/cgfsng.c
index cf75319..fad0be4 100644
--- a/src/lxc/cgfsng.c
+++ b/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 @@ static inline bool cgfsng_create(void *hdata)
}
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 @@ static bool cgfsng_escape()
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;
More information about the lxc-devel
mailing list