From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 9 Aug 2022 13:52:23 +0000 (+0000)
Subject: cgroup: Fix destruction function
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=01cf61344d3eb6cfb3e16f875037361e35c647b5;p=people%2Fstevee%2Fpakfire.git

cgroup: Fix destruction function

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/libpakfire/cgroup.c b/src/libpakfire/cgroup.c
index 0c902d85..873d13da 100644
--- a/src/libpakfire/cgroup.c
+++ b/src/libpakfire/cgroup.c
@@ -156,6 +156,16 @@ static void pakfire_cgroup_free(struct pakfire_cgroup* cgroup) {
 	free(cgroup);
 }
 
+static int pakfire_cgroup_open_root(struct pakfire_cgroup* cgroup) {
+	int fd = open(ROOT, O_DIRECTORY|O_PATH|O_CLOEXEC);
+	if (fd < 0) {
+		ERROR(cgroup->pakfire, "Could not open %s: %m\n", ROOT);
+		return -1;
+	}
+
+	return fd;
+}
+
 static int __pakfire_cgroup_create(struct pakfire_cgroup* cgroup) {
 	char path[PATH_MAX];
 	int r;
@@ -179,16 +189,13 @@ static int __pakfire_cgroup_create(struct pakfire_cgroup* cgroup) {
 	This function returns a negative value on error.
 */
 static int __pakfire_cgroup_open(struct pakfire_cgroup* cgroup) {
-	int rootfd = -1;
 	int fd = -1;
 	int r;
 
 	// Open file descriptor of the cgroup root
-	rootfd = open(ROOT, O_DIRECTORY|O_PATH|O_CLOEXEC);
-	if (rootfd < 0) {
-		ERROR(cgroup->pakfire, "Could not open %s: %m\n", ROOT);
+	int rootfd = pakfire_cgroup_open_root(cgroup);
+	if (rootfd < 0)
 		return -1;
-	}
 
 	// Return the rootfd for the root group
 	if (pakfire_cgroup_is_root(cgroup))
@@ -508,25 +515,39 @@ int pakfire_cgroup_killall(struct pakfire_cgroup* cgroup) {
 int pakfire_cgroup_destroy(struct pakfire_cgroup* cgroup) {
 	int r;
 
+	// Cannot call this for the root group
+	if (pakfire_cgroup_is_root(cgroup)) {
+		errno = EPERM;
+		return 1;
+	}
+
+	DEBUG(cgroup->pakfire, "Destroying cgroup %s\n", pakfire_cgroup_name(cgroup));
+
 	// Kill everything in this group
 	r = pakfire_cgroup_killall(cgroup);
 	if (r)
 		return r;
 
-	// Delete the directory
-	r = rmdir(cgroup->path);
-	if (r) {
-		ERROR(cgroup->pakfire, "Could not destroy cgroup: %m\n");
-		return r;
-	}
-
 	// Close the file descriptor
 	if (cgroup->fd) {
 		close(cgroup->fd);
 		cgroup->fd = 0;
 	}
 
-	return 0;
+	// Open the root directory
+	int fd = pakfire_cgroup_open_root(cgroup);
+	if (fd < 0)
+		return 1;
+
+	// Delete the directory
+	r = unlinkat(fd, cgroup->path, AT_REMOVEDIR);
+	if (r)
+		ERROR(cgroup->pakfire, "Could not destroy cgroup: %m\n");
+
+	// Close fd
+	close(fd);
+
+	return r;
 }
 
 int pakfire_cgroup_fd(struct pakfire_cgroup* cgroup) {