From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Tue, 10 Jan 2023 14:13:27 +0000 (+0000)
Subject: tools/cgdelete: add support for default systemd delegation slice/scope
X-Git-Tag: v3.1.0~209
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=529f0e77f4e252187298a4e91c891efc1223cd56;p=thirdparty%2Flibcgroup.git

tools/cgdelete: add support for default systemd delegation slice/scope

Enhance the cgdelete tool to support default systemd delegation
slice/scope, if set in the cgconfig.conf's systemd setting.  Parse the
configuration file and read the systemd::delegate setting, if any,
and set it as the default systemd slice/scope in systemd_default_cgroup.
Setting it appends the slice/scope name to the constructed default cgroup
mount path.

When the user passes the relative cgroup name, its appends to the
sub-tree (delegated slice/scope) by default and if the user wishes to
delete the cgroups in another subtree or cgroup root hierarchy, they
need to use the absolute path. For example:
		  cgroup_root
		 /	    \
		/	     \
	 systemd.slice*      cgrp1
	       |
	 systemd.scope
	       |
	    cgrp-d1

* default system delegation slice/scope - read from cgconfig.conf
$ sudo cgdelete -g cpu:cgrp-d1

will delete the cgroup cgrp-d1 under the
cgroup_root:systemd_default_cgroup:cgrp-d1

and for deleting the cgroup cgrp1, the user can use:
$ sudo cgdelete -g cpu:/cgrp1

or use the newly introduced -b switch to ignore the systemd slice/scope:
$ sudo cgdelete -b -g cpu:cgrp1

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
---

diff --git a/src/tools/cgdelete.c b/src/tools/cgdelete.c
index 8bedc5de..5e85a931 100644
--- a/src/tools/cgdelete.c
+++ b/src/tools/cgdelete.c
@@ -44,6 +44,9 @@ static void usage(int status, const char *program_name)
 	info("  -g <controllers>:<path>	Control group to be removed (-g is optional)\n");
 	info("  -h, --help			Display this help\n");
 	info("  -r, --recursive		Recursively remove all subgroups\n");
+#ifdef WITH_SYSTEMD
+	info("  -b				Ignore default systemd delegate hierarchy\n");
+#endif
 }
 
 /*
@@ -110,6 +113,7 @@ static int skip_add_controller(int counter, int *skip, struct ext_cgroup_record
 
 int main(int argc, char *argv[])
 {
+	int ignore_default_systemd_delegate_slice = 0;
 	struct cgroup_group_spec **cgroup_list = NULL;
 	struct ext_cgroup_record *ecg_list = NULL;
 	struct cgroup_controller *cgc;
@@ -150,9 +154,16 @@ int main(int argc, char *argv[])
 	}
 
 	/* Parse arguments */
-	while ((c = getopt_long(argc, argv, "rhg:",
-		long_options, NULL)) > 0) {
+#ifdef WITH_SYSTEMD
+	while ((c = getopt_long(argc, argv, "rhg:b", long_options, NULL)) > 0) {
 		switch (c) {
+		case 'b':
+			ignore_default_systemd_delegate_slice = 1;
+			break;
+#else
+	while ((c = getopt_long(argc, argv, "rhg:", long_options, NULL)) > 0) {
+		switch (c) {
+#endif
 		case 'r':
 			flags |= CGFLAG_DELETE_RECURSIVE;
 			break;
@@ -175,6 +186,10 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	/* this is false always for disable-systemd */
+	if (!ignore_default_systemd_delegate_slice)
+		cgroup_set_default_systemd_cgroup();
+
 	/* parse groups on command line */
 	for (i = optind; i < argc; i++) {
 		ret = parse_cgroup_spec(cgroup_list, argv[i], argc);