This patch adds cgset tool

This patch adds cgset tool, which sets parameters of controllers
for given cgroup based on input name-variable pairs
- the syntax is:

cgset -r <name=value> <relative path to cgroup>

-------------------------------------------------
EXAMPLES:
$ cgcreate -g cpuset:test1
$ cgset -r cpuset.cpus=1 test
$ cat ./test/cpuset.cpus
1

$ cgcreate -g cpuset:test1 -g cpuset:test2
$ cgset -r cpuset.cpus=0 test1 test2
$ cat /mnt/cgroups/cpuset/test1/cpuset.cpus
0
$ cat /mnt/cgroups/cpuset/test2/cpuset.cpus
0

Signed-off-by: Ivana Varekova <varekova@redhat.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>

diff --git a/src/tools/Makefile.am b/src/tools/Makefile.am
index 73f91300b4b5de38420d42e0ba7d805feda84c16..2b4c9e7cdcf7caf1cad426e87a8321d7b62cec88 100644 (file)
--- a/src/tools/Makefile.am
+++ b/src/tools/Makefile.am
@@ -3,7 +3,7 @@ LDADD = $(top_srcdir)/src/.libs/libcgroup.la
 
 if WITH_TOOLS
 
-bin_PROGRAMS = cgexec cgclassify cgcreate
+bin_PROGRAMS = cgexec cgclassify cgcreate cgset
 
 sbin_PROGRAMS = cgconfigparser
 

diff --git a/src/tools/cgset.c b/src/tools/cgset.c
new file mode 100644 (file)
index 0000000..be234be
--- /dev/null
+++ b/src/tools/cgset.c
@@ -0,0 +1,178 @@
+#include <libcgroup.h>
+#include <libcgroup-internal.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "tools-common.h"
+
+int main(int argc, char *argv[])
+{
+       int ret = 0;
+       int i;
+       char c;
+
+       char *buf;
+       char con[FILENAME_MAX];
+       struct control_value *name_value = NULL;
+       int nv_number = 0;
+       int nv_max = 0;
+
+       struct cgroup *cgroup;
+       struct cgroup_controller *cgc;
+
+       /* no parametr on input */
+       if (argc < 2) {
+               fprintf(stderr, "Usage is %s -r <name=value> "
+                       "<relative path to cgroup>\n", argv[0]);
+               return -1;
+       }
+
+       /* parse arguments */
+       while ((c = getopt(argc, argv, "r:")) > 0) {
+               switch (c) {
+               case 'r':
+                       /* add name-value pair to buffer
+                               (= name_value variable) */
+                       if (nv_number >= nv_max) {
+                               nv_max += CG_NV_MAX;
+                               name_value = (struct control_value *)
+                                       realloc(name_value,
+                                       nv_max * sizeof(struct control_value));
+                               if (!name_value) {
+                                       fprintf(stderr, "cgset: "
+                                               "not enough memory\n");
+                                       ret = -1;
+                                       goto err;
+                               }
+                       }
+
+                       /* parse optarg value */
+                       /* there is necessary to input the tuple n=v */
+                       buf = strtok(optarg, "=");
+                       if (buf == NULL) {
+                               fprintf(stderr, "%s: "
+                                       "wrong parameter of option -r: %s\n",
+                                       argv[0], optarg);
+                               ret = -1;
+                               goto err;
+                       }
+
+                       strncpy(name_value[nv_number].name, buf, FILENAME_MAX);
+                       name_value[nv_number].name[FILENAME_MAX-1] = '\0';
+
+                       buf = strtok(NULL, "=");
+                       if (buf == NULL) {
+                               fprintf(stderr, "%s: "
+                                       "wrong parameter of option -r: %s\n",
+                                       argv[0], optarg);
+                               ret = -1;
+                               goto err;
+                       }
+
+                       strncpy(name_value[nv_number].value, buf, CG_VALUE_MAX);
+                       name_value[nv_number].value[CG_VALUE_MAX-1] = '\0';
+
+                       nv_number++;
+                       break;
+               default:
+                       fprintf(stderr, "%s: invalid command line option\n",
+                               argv[0]);
+                       ret = -1;
+                       goto err;
+                       break;
+               }
+       }
+
+       /* no cgroup name */
+       if (!argv[optind]) {
+               fprintf(stderr, "%s: no cgroup specified\n", argv[0]);
+               ret = -1;
+               goto err;
+       }
+
+       if (nv_number == 0) {
+               fprintf(stderr, "%s: no name-value pair was set\n", argv[0]);
+               ret = -1;
+               goto err;
+       }
+
+       /* initialize libcgroup */
+       ret = cgroup_init();
+       if (ret) {
+               fprintf(stderr, "%s: libcgroup initialization failed: %s\n",
+                       argv[0], cgroup_strerror(ret));
+               goto err;
+       }
+
+       while (optind < argc) {
+
+               /* create new cgroup */
+               cgroup = cgroup_new_cgroup(argv[optind]);
+               if (!cgroup) {
+                       ret = ECGFAIL;
+                       fprintf(stderr, "%s: can't add new cgroup: %s\n",
+                               argv[0], cgroup_strerror(ret));
+                       ret = -1;
+                       goto err;
+               }
+
+               /* add pairs name-value to
+                  relevant controllers of this cgroup */
+               for (i = 0; i < nv_number; i++) {
+
+                       if ((strchr(name_value[i].name, '.')) == NULL) {
+                               fprintf(stderr, "%s: "
+                                       "wrong -r  parameter (%s=%s)\n",
+                                       argv[0], name_value[i].name,
+                                       name_value[i].value);
+                               ret = -1;
+                               goto cgroup_free_err;
+                       }
+
+                       strncpy(con, name_value[i].name, FILENAME_MAX);
+                       strtok(con, ".");
+
+                       /* add relevant controller */
+                       cgc = cgroup_add_controller(cgroup, con);
+                       if (!cgc) {
+                               fprintf(stderr, "%s: "
+                                       "controller %s can't be add\n",
+                                       argv[0], con);
+                               goto cgroup_free_err;
+                       }
+
+                       /* add name-value pair to this controller */
+                       ret = cgroup_add_value_string(cgc,
+                               name_value[i].name, name_value[i].value);
+                       if (ret) {
+                               fprintf(stderr, "%s: "
+                                       "name-value pair %s=%s "
+                                       "can't be set\n",
+                                       argv[0], name_value[i].name,
+                                       name_value[i].value);
+                               goto cgroup_free_err;
+                       }
+               }
+
+               /* modify cgroup */
+               ret = cgroup_modify_cgroup(cgroup);
+               if (ret) {
+                       fprintf(stderr, "%s: "
+                               "the group can't be modified\n",
+                               argv[0]);
+                       goto cgroup_free_err;
+               }
+
+               optind++;
+               cgroup_free(&cgroup);
+       }
+cgroup_free_err:
+       if (ret)
+               cgroup_free(&cgroup);
+err:
+       free(name_value);
+       return ret;
+}