cgls: beef up control group dumping and introduce cgls tool

6 files changed, 304 insertions, 49 deletions

diff --git a/src/cgroup-show.c b/src/cgroup-show.c
index b637c1c163..b44180e1fb 100644
--- a/src/cgroup-show.c
+++ b/src/cgroup-show.c
@@ -21,6 +21,8 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <dirent.h>
+#include <errno.h>
 
 #include "util.h"
 #include "macro.h"
@@ -36,25 +38,57 @@ static int compare(const void *a, const void *b) {
         return 0;
 }
 
-void show_cgroup(const char *name, const char *prefix, unsigned columns) {
+static char *get_cgroup_path(const char *name) {
+
+        if (startswith(name, "name=systemd:"))
+                name += 13;
+
+        if (path_startswith(name, "/cgroup"))
+                return strdup(name);
+
+        return strappend("/cgroup/systemd/", name);
+}
+
+static unsigned ilog10(unsigned long ul) {
+        int n = 0;
+
+        while (ul > 0) {
+                n++;
+                ul /= 10;
+        }
+
+        return n;
+}
+
+static int show_cgroup_full(const char *name, const char *prefix, unsigned n_columns, bool more) {
         char *fn;
         FILE *f;
         size_t n = 0, n_allocated = 0;
         pid_t *pids = NULL;
+        char *p;
+        int r;
+        unsigned long biggest = 0;
 
-        if (!startswith(name, "name=systemd:"))
-                return;
+        if (n_columns <= 0)
+                n_columns = columns();
 
-        if (asprintf(&fn, "/cgroup/systemd/%s/cgroup.procs", name + 13) < 0) {
-                log_error("Out of memory");
-                return;
-        }
+        if (!prefix)
+                prefix = "";
+
+        if (!(p = get_cgroup_path(name)))
+                return -ENOMEM;
 
-        f = fopen(fn, "r");
+        r = asprintf(&fn, "%s/cgroup.procs", p);
+        free(p);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        f = fopen(fn, "re");
         free(fn);
 
         if (!f)
-                return;
+                return -errno;
 
         while (!feof(f)) {
                 unsigned long ul;
@@ -71,7 +105,7 @@ void show_cgroup(const char *name, const char *prefix, unsigned columns) {
                         n_allocated = MAX(16U, n*2U);
 
                         if (!(npids = realloc(pids, sizeof(pid_t) * n_allocated))) {
-                                log_error("Out of memory");
+                                r = -ENOMEM;
                                 goto finish;
                         }
 
@@ -80,6 +114,9 @@ void show_cgroup(const char *name, const char *prefix, unsigned columns) {
 
                 assert(n < n_allocated);
                 pids[n++] = (pid_t) ul;
+
+                if (ul > biggest)
+                        biggest = ul;
         }
 
         if (n > 0) {
@@ -102,33 +139,124 @@ void show_cgroup(const char *name, const char *prefix, unsigned columns) {
                 /* And sort */
                 qsort(pids, n, sizeof(pid_t), compare);
 
-                if (!prefix)
-                        prefix = "";
-
-                if (columns > 8)
-                        columns -= 8;
+                if (n_columns > 8)
+                        n_columns -= 8;
                 else
-                        columns = 20;
-
-                printf("%s\342\224\202\n", prefix);
+                        n_columns = 20;
 
                 for (i = 0; i < n; i++) {
                         char *t = NULL;
 
-                        get_process_cmdline(pids[i], columns, &t);
+                        get_process_cmdline(pids[i], n_columns, &t);
 
-                        printf("%s%s %5lu %s\n",
+                        printf("%s%s %*lu %s\n",
                                prefix,
-                               i < n-1 ? "\342\224\234" : "\342\224\224",
-                               (unsigned long) pids[i], strna(t));
+                               (more || i < n-1) ? "\342\224\234" : "\342\224\224",
+                               ilog10(biggest),
+                               (unsigned long) pids[i],
+                               strna(t));
 
                         free(t);
                 }
         }
 
+        r = 0;
+
 finish:
         free(pids);
 
         if (f)
                 fclose(f);
+
+        return r;
+}
+
+int show_cgroup(const char *name, const char *prefix, unsigned n_columns) {
+        return show_cgroup_full(name, prefix, n_columns, false);
+}
+
+int show_cgroup_recursive(const char *name, const char *prefix, unsigned n_columns) {
+        DIR *d;
+        char *last = NULL;
+        char *p1 = NULL, *p2 = NULL, *fn = NULL;
+        struct dirent *de;
+        bool shown_pids = false;
+        int r;
+
+        assert(name);
+
+        if (n_columns <= 0)
+                n_columns = columns();
+
+        if (!prefix)
+                prefix = "";
+
+        if (!(fn = get_cgroup_path(name)))
+                return -ENOMEM;
+
+        if (!(d = opendir(fn))) {
+                free(fn);
+                return -errno;
+        }
+
+        while ((de = readdir(d))) {
+
+                if (de->d_type != DT_DIR)
+                        continue;
+
+                if (ignore_file(de->d_name))
+                        continue;
+
+                if (!shown_pids) {
+                        show_cgroup_full(name, prefix, n_columns, true);
+                        shown_pids = true;
+                }
+
+                if (last) {
+                        printf("%s\342\224\234 %s\n", prefix, file_name_from_path(last));
+
+                        if (!p1)
+                                if (!(p1 = strappend(prefix, "\342\224\202 "))) {
+                                        r = -ENOMEM;
+                                        goto finish;
+                                }
+
+                        show_cgroup_recursive(last, p1, n_columns-2);
+
+                        free(last);
+                        last = NULL;
+                }
+
+                if (asprintf(&last, "%s/%s", name, de->d_name) < 0) {
+                        log_error("Out of memory");
+                        goto finish;
+                }
+        }
+
+        if (!shown_pids)
+                show_cgroup_full(name, prefix, n_columns, !!last);
+
+        if (last) {
+                printf("%s\342\224\224 %s\n", prefix, file_name_from_path(last));
+
+                if (!p2)
+                        if (!(p2 = strappend(prefix, "  "))) {
+                                r = -ENOMEM;
+                                goto finish;
+                        }
+
+                show_cgroup_recursive(last, p2, n_columns-2);
+        }
+
+        r = 0;
+
+finish:
+        free(p1);
+        free(p2);
+        free(last);
+        free(fn);
+
+        closedir(d);
+
+        return r;
 }
diff --git a/src/cgroup-show.h b/src/cgroup-show.h
index 3def2f3095..1f0c319054 100644
--- a/src/cgroup-show.h
+++ b/src/cgroup-show.h
@@ -22,6 +22,7 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-void show_cgroup(const char *name, const char *prefix, unsigned columns);
+int show_cgroup(const char *name, const char *prefix, unsigned columns);
+int show_cgroup_recursive(const char *name, const char *prefix, unsigned columns);
 
 #endif
diff --git a/src/systemctl.c b/src/systemctl.c
index bb831adb5c..a9a975ee81 100644
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -110,30 +110,6 @@ static int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *da
         return 0;
 }
 
-static int columns(void) {
-        static int parsed_columns = 0;
-        const char *e;
-
-        if (parsed_columns > 0)
-                return parsed_columns;
-
-        if ((e = getenv("COLUMNS")))
-                parsed_columns = atoi(e);
-
-        if (parsed_columns <= 0) {
-                struct winsize ws;
-                zero(ws);
-
-                if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
-                        parsed_columns = ws.ws_col;
-        }
-
-        if (parsed_columns <= 0)
-                parsed_columns = 80;
-
-        return parsed_columns;
-}
-
 static void warn_wall(enum action action) {
         static const char *table[_ACTION_MAX] = {
                 [ACTION_HALT]      = "The system is going down for system halt NOW!",
@@ -1076,7 +1052,7 @@ static void print_status_info(UnitStatusInfo *i) {
                 else
                         c = 0;
 
-                show_cgroup(i->default_control_group, "\t\t  ", c);
+                show_cgroup_recursive(i->default_control_group, "\t\t  ", c);
         }
 }
 
@@ -3068,7 +3044,7 @@ static int systemctl_main(DBusConnection *bus, int argc, char *argv[]) {
                 { "reboot",            EQUAL, 1, start_special   },
                 { "default",           EQUAL, 1, start_special   },
                 { "rescue",            EQUAL, 1, start_special   },
-                { "emergency",         EQUAL, 1, start_special   },
+                { "emergency",         EQUAL, 1, start_special   }
         };
 
         int left;
diff --git a/src/systemd-cgls.c b/src/systemd-cgls.c
new file mode 100644
index 0000000000..6614f0fd25
--- /dev/null
+++ b/src/systemd-cgls.c
@@ -0,0 +1,121 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd 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.
+
+  systemd 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.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <limits.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <getopt.h>
+#include <string.h>
+
+#include "cgroup-show.h"
+#include "log.h"
+#include "util.h"
+
+static void help(void) {
+
+        printf("%s [OPTIONS...] [CGROUP...]\n\n"
+               "Recursively show control group contents.\n\n"
+               "  -h --help         Show this help\n",
+               program_invocation_short_name);
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        static const struct option options[] = {
+                { "help",      no_argument,       NULL, 'h'         },
+                { NULL,        0,                 NULL, 0           }
+        };
+
+        int c;
+
+        assert(argc >= 1);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        return -EINVAL;
+                }
+        }
+
+        return 1;
+}
+
+int main(int argc, char *argv[]) {
+        int r = 0, retval = 1;
+
+        log_parse_environment();
+
+        if ((r = parse_argv(argc, argv)) < 0)
+                goto finish;
+        else if (r == 0) {
+                retval = 0;
+                goto finish;
+        }
+
+        if (optind < argc) {
+                unsigned i;
+
+                for (i = (unsigned) optind; i < (unsigned) argc; i++) {
+                        int q;
+                        printf("%s:\n", argv[i]);
+
+                        if ((q = show_cgroup_recursive(argv[i], NULL, 0)) < 0)
+                                r = q;
+                }
+
+        } else {
+                char *p;
+
+                if (!(p = get_current_dir_name())) {
+                        log_error("Cannot determine current working directory: %m");
+                        goto finish;
+                }
+
+                if (path_startswith(p, "/cgroup")) {
+                        printf("Working Directory %s:\n", p);
+                        r = show_cgroup_recursive(p, NULL, 0);
+                } else
+                        r = show_cgroup_recursive("", NULL, 0);
+
+                free(p);
+        }
+
+        if (r < 0)
+                log_error("Failed to list cgroup tree: %s", strerror(-r));
+
+        retval = 0;
+
+finish:
+
+        return retval;
+}
diff --git a/src/util.c b/src/util.c
index 6cbc7ce477..2e5827f32d 100644
--- a/src/util.c
+++ b/src/util.c
@@ -609,6 +609,9 @@ int get_process_cmdline(pid_t pid, size_t max_length, char **line) {
 
         fclose(f);
 
+        if (r[0] == 0)
+                return get_process_name(pid, line);
+
         *line = r;
         return 0;
 }
@@ -2798,6 +2801,30 @@ char **replace_env_argv(char **argv, char **env) {
         return r;
 }
 
+int columns(void) {
+        static __thread int parsed_columns = 0;
+        const char *e;
+
+        if (parsed_columns > 0)
+                return parsed_columns;
+
+        if ((e = getenv("COLUMNS")))
+                parsed_columns = atoi(e);
+
+        if (parsed_columns <= 0) {
+                struct winsize ws;
+                zero(ws);
+
+                if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
+                        parsed_columns = ws.ws_col;
+        }
+
+        if (parsed_columns <= 0)
+                parsed_columns = 80;
+
+        return parsed_columns;
+}
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",
diff --git a/src/util.h b/src/util.h
index b29f890b5f..5d51c07e2f 100644
--- a/src/util.h
+++ b/src/util.h
@@ -328,6 +328,8 @@ void status_vprintf(const char *format, va_list ap);
 void status_printf(const char *format, ...);
 void status_welcome(void);
 
+int columns(void);
+
 const char *ioprio_class_to_string(int i);
 int ioprio_class_from_string(const char *s);