diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | api.c | 150 | ||||
| -rw-r--r-- | libcg.h | 23 |
3 files changed, 90 insertions, 85 deletions
@@ -20,7 +20,7 @@ LDFLAGS= -L . all: cgconfig libcg.so cgconfig: libcg.so config.c y.tab.c lex.yy.c libcg.h file-ops.c - $(CXX) $(CFLAGS) -o $@ y.tab.c lex.yy.c config.c file-ops.c $(LDFLAGS) $(LIBS) + $(CC) $(CFLAGS) -o $@ y.tab.c lex.yy.c config.c file-ops.c $(LDFLAGS) $(LIBS) y.tab.c: parse.y lex.yy.c byacc -v -d parse.y @@ -75,21 +75,33 @@ static inline pid_t cg_gettid() return syscall(__NR_gettid); } -/* +static char* cg_build_path(char *name, char *path) +{ + strcpy(path, MOUNT_POINT); + strcat(path, name); + strcat(path, "/"); + return path; +} + +/** cg_attach_task_pid is used to assign tasks to a cgroup. + * struct cgroup *cgroup: The cgroup to assign the thread to. + * pid_t tid: The thread to be assigned to the cgroup. + * + * returns 0 on success. + * returns ECGROUPNOTOWNER if the caller does not have access to the cgroup. + * returns ECGROUPNOTALLOWED for other causes of failure. */ -int cg_attach_task_pid(char *cgroup, pid_t tid) +int cg_attach_task_pid(struct cgroup *cgroup, pid_t tid) { char path[FILENAME_MAX]; FILE *tasks; - if (cgroup == NULL) { - cgroup = (char *) malloc(sizeof(char)); - cgroup = "\0"; + if (cgroup == NULL) + strcpy(path, MOUNT_POINT); + else { + cg_build_path(cgroup->name, path); } - strcpy(path, MOUNT_POINT); - strcat(path, "/"); - strcat(path, cgroup); strcat(path, "/tasks"); tasks = fopen(path, "w"); @@ -107,12 +119,12 @@ int cg_attach_task_pid(char *cgroup, pid_t tid) } -/* - * Used to attach the task to a control group. +/** cg_attach_task is used to attach the current thread to a cgroup. + * struct cgroup *cgroup: The cgroup to assign the current thread to. * - * WARNING: Will change to use struct cgroup when it is implemented. + * See cg_attach_task_pid for return values. */ -int cg_attach_task(char *cgroup) +int cg_attach_task(struct cgroup *cgroup) { pid_t tid = cg_gettid(); int error; @@ -192,46 +204,37 @@ static int cg_set_control_value(char *path, char *val) return 0; } -/* - * WARNING: This API is not final. It WILL change format to use - * struct cgroup. This API will then become internal and be called something - * else. +/** cg_modify_cgroup modifies the cgroup control files. + * struct cgroup *cgroup: The name will be the cgroup to be modified. + * The values will be the values to be modified, those not mentioned + * in the structure will not be modified. * - * I am still not happy with how the data structure is looking at the moment, - * plus there are a couple of additional details to be worked out. Please - * do not rely on this API. - * - * Be prepared to change the implementation later once it shifts to - * struct cgroup in the real alpha release. - * - * The final version is expected to be - * - * int modify_cgroup(struct cgroup *original, struct cgroup *final); + * The uids cannot be modified yet. * - * where original is the cgroup which is to be modified and final is how it - * should look. + * returns 0 on success. * - * Also this version is still at one level since we do not have - * multi-hierarchy support in kernel. The real alpha release should have this - * issue sorted out as well. */ -int cg_modify_cgroup(char *cgroup, struct control_value *values[], int n) +int cg_modify_cgroup(struct cgroup *cgroup) { char path[FILENAME_MAX], base[FILENAME_MAX]; int i; int error; - strcpy(base, MOUNT_POINT); - strcat(base, "/"); - strcat(base, cgroup); - strcat(base, "/"); - - for (i = 0; i < n; i++, strcpy(path, base)) { - strcat(path, values[i]->name); - error = cg_set_control_value(path, values[i]->value); - if (error) - goto err; + cg_build_path(cgroup->name, base); + + for (i = 0; i < CG_CONTROLLER_MAX && cgroup->controller[i]; + i++, strcpy(path, base)) { + int j; + for(j = 0; j < CG_NV_MAX && + cgroup->controller[i]->values[j]; + j++, strcpy(path, base)) { + strcat(path, cgroup->controller[i]->values[j]->name); + error = cg_set_control_value(path, + cgroup->controller[i]->values[j]->value); + if (error) + goto err; + } } return 0; err: @@ -261,7 +264,7 @@ err: * multi-hierarchy support in kernel. The real alpha release should have this * issue sorted out as well. */ -int cg_create_cgroup(char *cgroup, struct control_value *values[], int n) +int cg_create_cgroup(struct cgroup *cgroup) { char path[FILENAME_MAX], base[FILENAME_MAX]; int i; @@ -270,46 +273,37 @@ int cg_create_cgroup(char *cgroup, struct control_value *values[], int n) if (MOUNT_POINT == NULL) return ECGROUPNOTMOUNTED; - strcpy(path, MOUNT_POINT); - strcat(path, "/"); - strcat(path, cgroup); + cg_build_path(cgroup->name, path); error = cg_create_control_group(path); - strcat(path, "/"); + strcpy(base, path); - for (i = 0; i < n; i++, strcpy(path, base)) { - strcat(path, values[i]->name); - error = cg_set_control_value(path, values[i]->value); - if (!error) - return error; + for (i = 0; i < CG_CONTROLLER_MAX && cgroup->controller[i]; + i++, strcpy(path, base)) { + int j; + for(j = 0; j < CG_NV_MAX && cgroup->controller[i]->values[j]; + j++, strcpy(path, base)) { + strcat(path, cgroup->controller[i]->values[j]->name); + error = cg_set_control_value(path, + cgroup->controller[i]->values[j]->value); + chown(path, cgroup->control_uid, cgroup->control_gid); + if (!error) + return error; + } } + strcpy(path, base); + strcat(path, "tasks"); + chown(path, cgroup->tasks_uid, cgroup->tasks_gid); return error; } -/* - * WARNING: This API is not final. It WILL change format to use - * struct cgroup. This API will then become internal and be called something - * else. - * - * I am still not happy with how the data structure is looking at the moment, - * plus there are a couple of additional details to be worked out. Please - * do not rely on this API. - * - * Be prepared to change the implementation later once it shifts to - * struct cgroup in the real alpha release. - * - * The final version is expected to be +/** cg_delete cgroup deletes a control group. + * struct cgroup *cgroup takes the group which is to be deleted. * - * int delete_cgroup(struct cgroup *group); - * - * where group is the group to be deleted. - * - * Also this version is still at one level since we do not have - * multi-hierarchy support in kernel. The real alpha release should have this - * issue sorted out as well. + * returns 0 on success. */ -int cg_delete_cgroup(char *cgroup) +int cg_delete_cgroup(struct cgroup *cgroup) { FILE *delete_tasks, *base_tasks; int tids; @@ -321,10 +315,8 @@ int cg_delete_cgroup(char *cgroup) base_tasks = fopen(path, "w"); - strcpy(path, MOUNT_POINT); - strcat(path, "/"); - strcat(path, cgroup); - strcat(path,"/tasks"); + cg_build_path(cgroup->name, path); + strcat(path,"tasks"); delete_tasks = fopen(path, "r"); @@ -333,9 +325,7 @@ int cg_delete_cgroup(char *cgroup) fprintf(base_tasks, "%d", tids); } - strcpy(path, MOUNT_POINT); - strcat(path, "/"); - strcat(path, cgroup); + cg_build_path(cgroup->name, path); error = rmdir(path); @@ -21,6 +21,7 @@ __BEGIN_DECLS #include <grp.h> +#include <linux/types.h> #include <stdio.h> #include <sys/stat.h> @@ -139,17 +140,31 @@ int cg_unmount_controllers(void); int cg_load_config(const char *pathname); void cg_unload_current_config(void); +#define CG_NV_MAX 100 +#define CG_CONTROLLER_MAX 100 /* Functions and structures that can be used by the application*/ struct control_value { char name[FILENAME_MAX]; char *value; }; +struct cgroup{ + char *name; + struct { + char *name; + struct control_value *values[CG_NV_MAX]; + } *controller[CG_CONTROLLER_MAX]; + uid_t tasks_uid; + gid_t tasks_gid; + uid_t control_uid; + gid_t control_gid; +}; + int cg_init(void); -int cg_attach_task(char *cgroup); -int cg_modify_cgroup(char *cgroup, struct control_value *values[], int n); -int cg_create_cgroup(char *cgroup, struct control_value *values[], int n); -int cg_delete_cgroup(char *cgroup); +int cg_attach_task(struct cgroup *cgroup); +int cg_modify_cgroup(struct cgroup *cgroup); +int cg_create_cgroup(struct cgroup *cgroup); +int cg_delete_cgroup(struct cgroup *cgroup); __END_DECLS |