lssubsys patch - adds omit controllers

Changes from previous version:
* put the return value check to separate subpackages
* change the test (info.hierarchy == hierarchy) to
 (info.hierarchy != hierarchy) to decrease the nesting depth
* use memset

This patch fixes lssubsys output - it fixes two problems:
1/ if there was subsystem attached to not-mounted hierarchy then
lssubsys -a
does not show this subsystems
EXAMPLE:

BROKEN:
$ ./lssubsys -am
cpuset
cpuacct /cgroup/memoryd
memory /cgroup/memory
freezer
net_cls /cgroup/net_cls

FIXED:
$ ./lssubsys -am
cpuset
ns							<- controller is in hierarchy but it is not mounted
cpu,devices					<- controller is in hierarchy but it is not mounted
cpuacct /cgroup/memoryd
memory /cgroup/memory
freezer
net_cls /cgroup/net_cls

Signed-off-by: Ivana Hutarova Varekova <varekova@redhat.com>
Signed-off-by: Jan Safranek <jsafrane@redhat.com>

diff --git a/src/tools/lssubsys.c b/src/tools/lssubsys.c
index 3e3a3dde11a3884a43c122f028d68d8414146fc7..306d4e0e050e345ff5012da1913653c22902bda5 100644 (file)
--- a/src/tools/lssubsys.c
+++ b/src/tools/lssubsys.c
@@ -36,11 +36,16 @@ static void usage(int status, const char *program_name)
        } else {
                fprintf(stdout, "Usage: %s [-m] [controller] [...]\n",
                        program_name);
-               fprintf(stdout, "list all sybsystems of given controller\n");
+               fprintf(stdout, "Usage: %s -a [-m] \n",
+                       program_name);
+               fprintf(stdout, "List information about given controller(s). "\
+                       "If no controller is set list information about "\
+                       "all mounted controllers.\n");
                fprintf(stdout, "  -h, --help           Display this help\n");
                fprintf(stdout, "  -m, --mount-points   Display mount points\n");
-               fprintf(stdout, "  -a, --all            ");
-               fprintf(stdout, "Display all not mounted subsystems\n");
+               fprintf(stdout, "  -a, --all            "\
+                       "Display information about all controllers "\
+                       "(including not mounted ones) \n");
        }
 }
 
@@ -163,28 +168,131 @@ static int cgroup_list_controllers(const char *tname,
        return final_ret;
 }
 
-static int cgroup_list_all_controllers(const char *tname)
+/* display all controllers attached to the given hierarchy */
+static int print_all_controllers_in_hierarchy(const char *tname,
+       int hierarchy, int flags)
 {
        int ret = 0;
        void *handle;
        struct controller_data info;
+       int first = 1;
+       cont_name_t cont_name;
+       int init = 1;
+
+       /* initialize libcgroup */
+       ret = cgroup_init();
+       if (ret) {
+               /*
+                * if the group is not initialised we assume
+                * no mount points are available
+                */
+               init = 0;
+       }
 
        ret = cgroup_get_all_controller_begin(&handle, &info);
 
        while (ret != ECGEOF) {
-               if (info.hierarchy == 0)
-                       printf("%s\n", info.name);
+               /* controller is in the hierrachy */
+               if (info.hierarchy != hierarchy)
+                       goto next;
+
+               /* the first controller in the hierrachy*/
+               if (first) {
+                       /*
+                        * if mounted flag is set then
+                        * test whether it is mounted
+                        */
+                       if ((flags & FL_MOUNT) && (init == 1)) {
+                               memset(cont_name, 0, FILENAME_MAX);
+                               strncpy(cont_name, info.name,
+                                       FILENAME_MAX-1);
+
+                               ret = print_controller(cont_name,
+                                       flags + FL_LIST);
+                               /*
+                                * mount point was found,
+                                * output is done
+                                */
+                               if (ret == 0) {
+                                       cgroup_get_all_controller_end(
+                                               &handle);
+                                       return 0;
+                               }
+                       }
+                       printf("%s", info.name);
+                       first = 0;
+               } else
+                       printf(",%s", info.name);
+
+next:
                ret = cgroup_get_all_controller_next(&handle, &info);
                if (ret && ret != ECGEOF) {
                        fprintf(stderr,
                                "%s: cgroup_get_controller_next failed (%s)\n",
                                tname, cgroup_strerror(ret));
+                       cgroup_get_all_controller_end(&handle);
+                       return ret;
+               }
+       }
+
+       cgroup_get_all_controller_end(&handle);
+       printf("\n");
+
+       if (ret == ECGEOF)
+               ret = 0;
+
+       return ret;
+}
+
+/* go through the list of all controllers gather them based on hierarchy number
+ and print them */
+static int cgroup_list_all_controllers(const char *tname, int flags)
+{
+       int ret = 0;
+       void *handle;
+       struct controller_data info;
+
+       int h_list[CG_CONTROLLER_MAX];  /* list of hierarchies */
+       int counter = 0;
+       int j;
+
+       ret = cgroup_get_all_controller_begin(&handle, &info);
+
+       while (ret != ECGEOF) {
+               if (info.hierarchy == 0) {
+                       /* the controller is not attached to any hierrachy */
+                       printf("%s\n", info.name);
+               } else {
+                       /* the controller is attached to some hierarchy */
+                       h_list[counter] = info.hierarchy;
+                       counter++;
+                       for (j = 0; j < counter-1; j++) {
+                               /*
+                                * the hierarchy already was on the list
+                                * so remove the new record
+                                */
+                               if (h_list[j] == info.hierarchy) {
+                                       counter--;
+                                       break;
+                               }
+                       }
+               }
+
+               ret = cgroup_get_all_controller_next(&handle, &info);
+               if (ret && ret != ECGEOF) {
+                       fprintf(stderr,
+                               "cgroup_get_controller_next failed (%s)\n",
+                               cgroup_strerror(ret));
                        return ret;
                }
        }
 
        ret = cgroup_get_all_controller_end(&handle);
 
+       for (j = 0; j < counter; j++)
+               ret = print_all_controllers_in_hierarchy(tname,
+                       h_list[j], flags);
+
        return ret;
 
 }
@@ -231,28 +339,27 @@ int main(int argc, char *argv[])
 
        /* read the list of controllers */
        while (optind < argc) {
-
+               if (flags & FL_ALL) {
+                       fprintf(stderr, "Warning: too many parameters\n");
+                       break;
+               }
                flags |= FL_LIST;
                strncpy(cont_name[c_number], argv[optind], FILENAME_MAX);
                cont_name[c_number][FILENAME_MAX-1] = '\0';
                c_number++;
                optind++;
                if (optind == CG_CONTROLLER_MAX) {
-                       fprintf(stderr, "too much parameters\n");
+                       fprintf(stderr, "Warning: too many parameters\n");
                        break;
                }
        }
 
-       /*
-        * print the information
-        * based on list of input controllers and flags
-        */
-       ret = cgroup_list_controllers(argv[0], cont_name, flags);
-       if (ret)
-               return ret;
-
        if (flags & FL_ALL)
-               ret = cgroup_list_all_controllers(argv[0]);
+               /* print the information about all controllers */
+               ret = cgroup_list_all_controllers(argv[0], flags);
+       else
+               /* print information about mounted controllers */
+               ret = cgroup_list_controllers(argv[0], cont_name, flags);
 
        return ret;
 }