From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 14 Dec 2024 13:54:20 +0000 (+0000)
Subject: cgroups: Refactor the code that creates a cgroup
X-Git-Tag: 0.9.30~720
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ebb69a77e52208416afdf80843b72b1b04ac3ff5;p=pakfire.git

cgroups: Refactor the code that creates a cgroup

The previous solution seemed to be very complicated, but this one will
likely have an extra syscall in some cases.

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

diff --git a/src/libpakfire/cgroup.c b/src/libpakfire/cgroup.c
index 2581426bc..786f0f898 100644
--- a/src/libpakfire/cgroup.c
+++ b/src/libpakfire/cgroup.c
@@ -161,26 +161,26 @@ static int __pakfire_cgroup_open(struct pakfire_cgroup* cgroup) {
 	if (!cgroup->parent)
 		return pakfire_cgroup_open_root(cgroup);
 
-	// Try to open the cgroup
-	fd = openat(cgroup->parent->fd, cgroup->name, O_DIRECTORY|O_PATH|O_CLOEXEC);
-	if (fd < 0) {
+	// Try creating the cgroup
+	r = mkdirat(cgroup->parent->fd, cgroup->name, 0755);
+	if (r < 0) {
 		switch (errno) {
-			case ENOENT:
-				r = mkdirat(cgroup->parent->fd, cgroup->name, 0755);
-				if (r < 0) {
-					ERROR(cgroup->ctx, "Could not create cgroup '%s': %m\n", cgroup->name);
-					return -errno;
-				}
-
-				// Try opening it again
-				return __pakfire_cgroup_open(cgroup);
+			case EEXIST:
+				break;
 
 			default:
-				ERROR(cgroup->ctx, "Could not open cgroup '%s': %m\n", cgroup->name);
+				ERROR(cgroup->ctx, "Could not create cgroup '%s': %m\n", cgroup->name);
 				return -errno;
 		}
 	}
 
+	// Try opening the cgroup
+	fd = openat(cgroup->parent->fd, cgroup->name, O_DIRECTORY|O_PATH|O_CLOEXEC);
+	if (fd < 0) {
+		ERROR(cgroup->ctx, "Could not open cgroup %s: %m\n", cgroup->path);
+		return -errno;
+	}
+
 	return fd;
 }