Hello Dave,
I have been working on a new command named lscgroup to
list cgroups' information and finished it recently.
This command displays all the cgroups' information or the
appointed cgroups' information relatively according to user's
input. The following shows the two types of output.
1.Display all the cgroups' information of the system.
crash>lscgroup
blkio:/
blkio:/libvirt
blkio:/libvirt/lxc
blkio:/libvirt/qemu
net_cls:/
...
...
cpuset:/
cpuset:/libvirt
cpuset:/libvirt/lxc
cpuset:/libvirt/qemu
2.Display the appointed cgroups' information.
crash> lscgroup memory:/ cpuset:/libvirt
memory:/
memory:/libvirt
memory:/libvirt/lxc
memory:/libvirt/qemu
cpuset:/libvirt
cpuset:/libvirt/lxc
cpuset:/libvirt/qemu
To see more details, please refer to the help information and the patch.
To build the module from the top-level crash-<version> directory, enter:
$ cp <path-to>/lscgroup.c extensions
$ make extensions
/* lscgroup.c - list cgroups
*
* Copyright (C) 2012 FUJITSU LIMITED
* Author: Yu Yongming <yuym.fnst@xxxxxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include "defs.h"
#define PATHNAME_MAX 200
#define ROOT_MAX 64
#define CG_CONTROLLER_MAX 20
#define CG_HIER_MAX 20
#define FL_LIST 0x1
#define CGROUP_MEMBER_OFFSET_INIT(X,Y,Z) (cgroup_offset_table.X=MEMBER_OFFSET(Y,Z))
#define CGROUP_OFFSET(X) (OFFSET_verify(cgroup_offset_table.X, (char *)__FUNCTION__, __FILE__, __LINE__, #X))
/*
*struct declaration
*/
struct cgroup_offset_table {
long cgroupfs_root_root_list;
long cgroupfs_root_top_cgroup;
long cgroupfs_root_subsys_list;
long cgroupfs_root_actual_subsys_bits;
long cgroupfs_root_name;
long cgroup_sibling;
long cgroup_children;
long cgroup_dentry;
long cgroup_subsys_name;
long cgroup_subsys_sibling;
};
struct cgroup_group_spec {
char path[PATHNAME_MAX];
char *controllers[CG_CONTROLLER_MAX];
};
/*
*function declaration
*/
int _init(void);
int _fini(void);
void cmd_lscgroup(void);
char *help_lscgroup[];
static void cgroup_init(void);
static void get_controller_name(ulong);
static void get_cgroup_name(ulong, char *);
static void parse_top_cgroup(ulong, char *);
static void print_all_cgroups(void);
static int in_cgroupfs_root(char *, struct cgroup_group_spec *);
static ulong locate_top_cgroup(struct cgroup_group_spec *);
static void parse_path(char *, char **);
static ulong locate_cgroup(ulong, ulong, char *);
static void standarlize_path(char *);
static void cgroup_elem_cgroup(struct cgroup_group_spec *);
static void cgroup_list_cgroups(char *, struct cgroup_group_spec **, int);
static int parse_cgroup_spec(struct cgroup_group_spec **, char *);
static void cgroup_free_group_spec(struct cgroup_group_spec *);
/*
* global data
*/
static char controller_name[PATHNAME_MAX];
static struct command_table_entry command_table[] = {
{"lscgroup", cmd_lscgroup, help_lscgroup, 0},
{NULL},
};
static struct cgroup_offset_table cgroup_offset_table = { 0 };
char *help_lscgroup[] = {
"lscgroup",
"list all cgroups",
"lscgroup [<controllers>:<path>] [...][-h]",
" The command list all/chosen cgroups.",
" <controllers>:<path> defines control groups which subgroups will be shown.",
" If this parameter is not used then the command list all cgroups which are",
" present.",
"\nEXAMPLE",
" display chosen cgroups:\n",
" %s>lscgroup cpuset:/libvirt",
" cpuset:/libvirt",
" cpuset:/libvirt/lxc",
" cpuset:/libvirt/qemu",
" ",
" display all cgroups:\n",
" %s>lscgroup",
" blkio:/",
" blkio:/libvirt",
" blkio:/libvirt/lxc",
" blkio:/libvirt/qemu",
" net_cls:/",
" freezer:/",
" freezer:/libvirt",
" freezer:/libvirt/lxc",
" freezer:/libvirt/qemu",
" devices:/",
" devices:/libvirt",
" devices:/libvirt/lxc",
" devices:/libvirt/qemu",
" memory:/",
" memory:/libvirt",
" memory:/libvirt/lxc",
" memory:/libvirt/qemu",
" cpuacct:/ ",
" cpuacct:/libvirt",
" cpuacct:/libvirt/lxc",
" cpuacct:/libvirt/qemu",
" cpu:/",
" cpu:/libvirt",
" cpu:/libvirt/lxc",
" cpu:/libvirt/qemu",
" cpuset:/",
" cpuset:/libvirt",
" cpuset:/libvirt/lxc",
" cpuset:/libvirt/qemu",
NULL
};
int
_init(void)
{
register_extension(command_table);
return 1;
}
int
_fini(void)
{
return 1;
}
static void
cgroup_init(void)
{
CGROUP_MEMBER_OFFSET_INIT(cgroupfs_root_root_list, "cgroupfs_root",
"root_list");
CGROUP_MEMBER_OFFSET_INIT(cgroupfs_root_top_cgroup, "cgroupfs_root",
"top_cgroup");
CGROUP_MEMBER_OFFSET_INIT(cgroupfs_root_subsys_list, "cgroupfs_root",
"subsys_list");
CGROUP_MEMBER_OFFSET_INIT(cgroupfs_root_actual_subsys_bits,
"cgroupfs_root", "actual_subsys_bits");
CGROUP_MEMBER_OFFSET_INIT(cgroupfs_root_name, "cgroupfs_root",
"name");
CGROUP_MEMBER_OFFSET_INIT(cgroup_sibling, "cgroup", "sibling");
CGROUP_MEMBER_OFFSET_INIT(cgroup_children, "cgroup", "children");
CGROUP_MEMBER_OFFSET_INIT(cgroup_dentry, "cgroup", "dentry");
CGROUP_MEMBER_OFFSET_INIT(cgroup_subsys_name, "cgroup_subsys", "name");
CGROUP_MEMBER_OFFSET_INIT(cgroup_subsys_sibling, "cgroup_subsys",
"sibling");
}
static void
get_controller_name(ulong cgroupfs_root)
{
char name[PATHNAME_MAX];
ulong subsys, next, subsys_list, name_buf, name_addr;
int len;
readmem(cgroupfs_root + CGROUP_OFFSET(cgroupfs_root_actual_subsys_bits),
KVADDR, &subsys, sizeof(ulong), "cgroupfs_root_actual_subsys",
FAULT_ON_ERROR);
if(subsys == 0) {
readmem(cgroupfs_root + CGROUP_OFFSET(cgroupfs_root_name),
KVADDR, &name, ROOT_MAX, "cgroupfs_root_name",
FAULT_ON_ERROR);
strcat(controller_name, name);
return ;
}
subsys_list = cgroupfs_root + CGROUP_OFFSET(cgroupfs_root_subsys_list);
readmem(subsys_list, KVADDR, &next, sizeof(ulong),
"cgroupfs_root_subsys_list", FAULT_ON_ERROR);
do {
name_buf = next - CGROUP_OFFSET(cgroup_subsys_sibling)
+ CGROUP_OFFSET(cgroup_subsys_name);
readmem(name_buf, KVADDR, &name_addr, sizeof(ulong),
"cgroup_subsys_name", FAULT_ON_ERROR);
readmem(name_addr, KVADDR, name, sizeof(name),
"char* name", FAULT_ON_ERROR);
strcat(controller_name, name);
strcat(controller_name, ",");
readmem(next, KVADDR, &next, sizeof(ulong),
"list_head", FAULT_ON_ERROR);
} while(next != subsys_list);
len = strlen(controller_name);
controller_name[len-1] = '\0';
}
static void
get_cgroup_name(ulong cgroup, char *name)
{
ulong dentry, name_addr;
char *dentry_buf;
int len;
readmem(cgroup + CGROUP_OFFSET(cgroup_dentry), KVADDR,
&dentry, sizeof(ulong), "cgroup dentry",
FAULT_ON_ERROR);
dentry_buf = GETBUF(SIZE(dentry));
readmem(dentry, KVADDR, dentry_buf, SIZE(dentry),
"dentry", FAULT_ON_ERROR);
len = UINT(dentry_buf + OFFSET(dentry_d_name) + OFFSET(qstr_len));
name_addr = ULONG(dentry_buf + OFFSET(dentry_d_name) + OFFSET(qstr_name));
readmem(name_addr, KVADDR, name, len, "qstr name", FAULT_ON_ERROR);
FREEBUF(dentry_buf);
}
static void
parse_top_cgroup(ulong top_cgroup, char *path)
{
int len;
char tmp_buf[PATHNAME_MAX];
ulong list_head[2], next, child;
BZERO(tmp_buf, PATHNAME_MAX);
get_cgroup_name(top_cgroup, tmp_buf);
if (strlen(path) > 1)
strncat(path, "/", 1);
strncat(path, tmp_buf, strlen(tmp_buf));
fprintf(fp, "%s:%s\n", controller_name, path);
child = top_cgroup + CGROUP_OFFSET(cgroup_children);
readmem(child, KVADDR, list_head, sizeof(ulong) * 2,
"cgroup children", FAULT_ON_ERROR);
if ((list_head[0] == child) && (list_head[1] == child))
return;
next = list_head[0];
while (next != child) {
top_cgroup = next - CGROUP_OFFSET(cgroup_sibling);
readmem(top_cgroup + CGROUP_OFFSET(cgroup_sibling) +
OFFSET(list_head_next), KVADDR, &next, sizeof(ulong),
"cgroup siblings", FAULT_ON_ERROR);
len = strlen(path);
parse_top_cgroup(top_cgroup, path);
path[len] = '\0';
}
}
static void
print_all_cgroups(void)
{
struct syment *roots;
ulong top_cgroup;
ulong list_head[2], next, cgroupfs_root;;
char path_name[PATHNAME_MAX];
BZERO(path_name, PATHNAME_MAX);
if (!(roots = symbol_search("roots")))
error(FATAL, "roots symbol does not exist?\n");
readmem(roots->value, KVADDR, list_head, sizeof(ulong) * 2,
"list_head", FAULT_ON_ERROR);
if ((list_head[0] == roots->value) && (list_head[1] == roots->value))
return;
next = list_head[0];
while (next != roots->value) {
cgroupfs_root = next - CGROUP_OFFSET(cgroupfs_root_root_list);
get_controller_name(cgroupfs_root);
top_cgroup = cgroupfs_root +
CGROUP_OFFSET(cgroupfs_root_top_cgroup);
/* print infomation of cgroup and subcgroup */
parse_top_cgroup(top_cgroup, path_name);
readmem(next + OFFSET(list_head_next), KVADDR, &next,
sizeof(ulong), "list_head next", FAULT_ON_ERROR);
BZERO(path_name, PATHNAME_MAX);
BZERO(controller_name, PATHNAME_MAX);
}
}
static int
in_cgroupfs_root(char *tmp_name, struct cgroup_group_spec *elem)
{
char *name;
int i = 0;
name = strtok(tmp_name, ",");
while(name != NULL) {
while(elem->controllers[i] != NULL && i < CG_CONTROLLER_MAX) {
if(STREQ(name, elem->controllers[i]))
return 1;
i++;
}
name = strtok(NULL, ",");
i = 0;
}
return 0;
}
static ulong
locate_top_cgroup(struct cgroup_group_spec *elem)
{
struct syment *roots;
ulong top_cgroup;
ulong list_head[2], next, cgroupfs_root;
char tmp_name[PATHNAME_MAX];
if (!(roots = symbol_search("roots")))
error(FATAL, "roots symbol does not exist?");
readmem(roots->value, KVADDR, list_head, sizeof(ulong)*2,
"list_head", FAULT_ON_ERROR);
if ((list_head[0] == roots->value) && (list_head[1] == roots->value))
return 0;
next = list_head[0];
while (next != roots->value) {
/* begin from first root */
cgroupfs_root = next - CGROUP_OFFSET(cgroupfs_root_root_list);
get_controller_name(cgroupfs_root);
strcpy(tmp_name, controller_name);
if (in_cgroupfs_root(tmp_name, elem)) {
top_cgroup = cgroupfs_root +
CGROUP_OFFSET(cgroupfs_root_top_cgroup);
return top_cgroup;
}
readmem(next + OFFSET(list_head_next), KVADDR, &next,
sizeof(ulong), "list_head", FAULT_ON_ERROR);
BZERO(controller_name, PATHNAME_MAX);
}
return 0;
}
/*
* function parse_path and extracts the input path before the first '/' as
* relatively path which will be used to compare with path name of cgroup.
* In addition, it ignores the unnecessary '/' in the path
*/
static void
parse_path(char *path, char **elem_path)
{
char *token;
token = *elem_path;
if (token[0] == '/') {
*path++ = *token++;
} else {
while (*token) {
if (*token == '/' && *(token + 1) == '/') {
token++;
} else if (*token == '/' && *(token + 1) != '/') {
token++;
break;
} else {
*path++ = *token++;
}
}
}
*elem_path = token;
*path = '\0';
}
static ulong
locate_cgroup(ulong current, ulong prev_addr, char *elem_path)
{
char tmp_buf[PATHNAME_MAX];
char path[PATHNAME_MAX];
char *tmp_path = elem_path;
ulong child, sibling, child_offset, sibling_offset;
if (*elem_path == '\0')
return prev_addr;
BZERO(tmp_buf, PATHNAME_MAX);
get_cgroup_name(current, tmp_buf);
parse_path(path, &elem_path);
readmem(current + CGROUP_OFFSET(cgroup_children), KVADDR, &child,
sizeof(ulong), "cgroup children", FAULT_ON_ERROR);
readmem(current + CGROUP_OFFSET(cgroup_sibling), KVADDR, &sibling,
sizeof(ulong), "cgroup sibling", FAULT_ON_ERROR);
child_offset = CGROUP_OFFSET(cgroup_children);
sibling_offset = CGROUP_OFFSET(cgroup_sibling);
/* parse the children if temp=path_name, do change elem_path */
if (STREQ(tmp_buf, path)) {
if ((child - child_offset != current))
return locate_cgroup(child - sibling_offset,
current, elem_path);
else if (*elem_path == '\0')
return current;
} else {
/* parse the sibling if temp !=path_name, do not chage elem_path */
if (((sibling - child_offset) != prev_addr) &&
((sibling - sibling_offset) != current)) {
elem_path = tmp_path;
return locate_cgroup(sibling - sibling_offset,
prev_addr, elem_path);
}
}
return 0;
}
/*
* make the input path begin with character '/' and end without character '/'
* to cope with the situation that the input path may be like "/xxxxx",
* "xxxxx", "xxxxx/", or "/xxxxx/"
*/
static void
standarlize_path(char *path)
{
int len;
len = strlen(path) - 1;
if (path[len] == '/')
path[len] = '\0';
if (path[0] != '/') {
len = strlen(path);
path[len + 1] = '\0';
while (len) {
path[len] = path[len - 1];
len--;
}
path[0] = '/';
}
}
static void
mani_path(char *path)
{
int len;
standarlize_path(path);
if (STREQ(path, "/")) {
*path = '\0';
return ;
}
len = strlen(path);
while (path[len] != '/') {
path[len] = '\0';
len--;
}
path[len] = '\0';
path[0] = '/';
}
static void
cgroup_elem_cgroup(struct cgroup_group_spec *list_elem)
{
ulong top_cgroup;
ulong cgroup;
char path_name[PATHNAME_MAX];
top_cgroup = locate_top_cgroup(list_elem);
if (top_cgroup == 0) {
fprintf(fp, "cannot find top cgroup, check the input.\n");
return;
}
strcpy(path_name, list_elem->path);
standarlize_path(path_name);
cgroup = locate_cgroup(top_cgroup, top_cgroup, path_name);
if (cgroup == 0) {
fprintf(fp, "can not find cgroup %s, check the input.\n",
list_elem->path);
return ;
}
mani_path(list_elem->path);
parse_top_cgroup(cgroup, list_elem->path);
}
static void
cgroup_list_cgroups(char *tname, struct cgroup_group_spec *cgroup_list[],
int flags)
{
int i;
i = 0;
cgroup_init();
if(CGROUP_OFFSET(cgroupfs_root_root_list) == -1) {
fprintf(fp, "cgroup does not exist, check kernel version.");
return ;
}
if ((flags & FL_LIST) == 0) {
/* list all the cgroups */
print_all_cgroups();
} else {
/* list the specified cgroups */
while ((cgroup_list[i]->path != NULL)) {
cgroup_elem_cgroup(cgroup_list[i]);
i++;
}
}
}
static int
parse_cgroup_spec(struct cgroup_group_spec **list, char *optarg)
{
struct cgroup_group_spec *ptr;
int i, j;
char *controller, *path, *temp;
ptr = *list;
for (i = 0; i < CG_HIER_MAX; i++, ptr++) {
if (!list[i])
break;
}
if (i == CG_HIER_MAX) {
fprintf(fp, "Max allowed hierarchies %d reached\n",
CG_HIER_MAX);
return -1;
}
controller = strtok(optarg, ":");
if (!controller)
return -1;
path = strtok(NULL, ":");
if (!path)
return -1;
list[i] = (struct cgroup_group_spec *)GETBUF(sizeof(**list));
j = 0;
do {
if (j == 0)
temp = strtok(controller, ",");
else
temp = strtok(NULL, ",");
if (temp) {
list[i]->controllers[j] = strdup(temp);
if (!list[i]->controllers[j]) {
FREEBUF(list[i]);
fprintf(fp, "%s\n", strerror(errno));
return -1;
}
}
j++;
} while (temp && (j < (CG_CONTROLLER_MAX - 1)));
strncpy(list[i]->path, path, strlen(path));
return 0;
}
static void
cgroup_free_group_spec(struct cgroup_group_spec *elem)
{
int i;
if (!elem)
return;
for (i = 0; i < CG_CONTROLLER_MAX; i++) {
if (elem->controllers[i])
free(elem->controllers[i]);
}
FREEBUF(elem);
}
void
cmd_lscgroup(void)
{
int c, i, ret, flags;
struct cgroup_group_spec *cgroup_list[CG_HIER_MAX];
ret = flags = 0;
while ((c = getopt(argcnt, args, "h")) != EOF) {
switch(c) {
case 'h':
cmd_usage(pc->curcmd, SYNOPSIS);
return ;
default:
cmd_usage(pc->curcmd, SYNOPSIS);
return ;
}
}
if (argerrs)
cmd_usage(pc->curcmd, SYNOPSIS);
BZERO(cgroup_list, sizeof(cgroup_list));
if (optind < argcnt)
flags |= FL_LIST;
while (args[optind]) {
ret = parse_cgroup_spec(cgroup_list, args[optind]);
if (ret) {
fprintf(fp, "%s: cgroup controller"
" and path parsing failed(%s)\n",
args[0], args[optind]);
}
optind++;
}
cgroup_list_cgroups(args[0], cgroup_list, flags);
if (!cgroup_list[0])
return;
for (i = 0; i < CG_HIER_MAX; i++)
cgroup_free_group_spec(cgroup_list[i]);
}
--
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