From 6f92e9048b5a008ac0d1dd2a81e0e8aeeffa9549 Mon Sep 17 00:00:00 2001
From: Michal Koutný <mkoutny@suse.com>
Date: May 29 2023 13:51:35 +0000
Subject: cgroup: Make cgroup_get_from_id() prettier (bsc#1205650).


---

diff --git a/patches.suse/cgroup-Make-cgroup_get_from_id-prettier.patch b/patches.suse/cgroup-Make-cgroup_get_from_id-prettier.patch
new file mode 100644
index 0000000..b48d21f
--- /dev/null
+++ b/patches.suse/cgroup-Make-cgroup_get_from_id-prettier.patch
@@ -0,0 +1,80 @@
+From: Tejun Heo <tj@kernel.org>
+Date: Fri, 23 Sep 2022 07:23:06 -1000
+Subject: cgroup: Make cgroup_get_from_id() prettier
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+Git-commit: 7e1eb5437d3c3fdb61d45378579aab383cafc694
+Patch-mainline: v6.1-rc1
+References: bsc#1205650
+
+After merging 836ac87d ("cgroup: fix cgroup_get_from_id") into for-6.1, its
+combination with two commits in for-6.1 - 4534dee9 ("cgroup: cgroup: Honor
+caller's cgroup NS when resolving cgroup id") and fa7e439c ("cgroup:
+Homogenize cgroup_get_from_id() return value") - makes the gotos in the
+error handling path too ugly while not adding anything of value.
+
+All that the gotos are saving is one extra kernfs_put() call. Let's remove
+the gotos and perform error returns directly.
+
+Signed-off-by: Tejun Heo <tj@kernel.org>
+Cc: Ming Lei <ming.lei@redhat.com>
+Cc: Michal Koutný <mkoutny@suse.com>
+
+Acked-by: Michal Koutný <mkoutny@suse.com>
+---
+ kernel/cgroup/cgroup.c | 19 ++++++++++---------
+ 1 file changed, 10 insertions(+), 9 deletions(-)
+
+diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
+index 0d93cd17548c..c1f1ef6090da 100644
+--- a/kernel/cgroup/cgroup.c
++++ b/kernel/cgroup/cgroup.c
+@@ -6066,14 +6066,16 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen)
+ struct cgroup *cgroup_get_from_id(u64 id)
+ {
+ 	struct kernfs_node *kn;
+-	struct cgroup *cgrp = NULL, *root_cgrp;
++	struct cgroup *cgrp, *root_cgrp;
+ 
+ 	kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id);
+ 	if (!kn)
+-		goto out;
++		return ERR_PTR(-ENOENT);
+ 
+-	if (kernfs_type(kn) != KERNFS_DIR)
+-		goto put;
++	if (kernfs_type(kn) != KERNFS_DIR) {
++		kernfs_put(kn);
++		return ERR_PTR(-ENOENT);
++	}
+ 
+ 	rcu_read_lock();
+ 
+@@ -6082,21 +6084,20 @@ struct cgroup *cgroup_get_from_id(u64 id)
+ 		cgrp = NULL;
+ 
+ 	rcu_read_unlock();
+-put:
+ 	kernfs_put(kn);
+ 
+ 	if (!cgrp)
+-		goto out;
++		return ERR_PTR(-ENOENT);
+ 
+ 	spin_lock_irq(&css_set_lock);
+ 	root_cgrp = current_cgns_cgroup_from_root(&cgrp_dfl_root);
+ 	spin_unlock_irq(&css_set_lock);
+ 	if (!cgroup_is_descendant(cgrp, root_cgrp)) {
+ 		cgroup_put(cgrp);
+-		cgrp = NULL;
++		return ERR_PTR(-ENOENT);
+ 	}
+-out:
+-	return cgrp ?: ERR_PTR(-ENOENT);
++
++	return cgrp;
+ }
+ EXPORT_SYMBOL_GPL(cgroup_get_from_id);
+ 
+
diff --git a/series.conf b/series.conf
index 30a9dd1..9823540 100644
--- a/series.conf
+++ b/series.conf
@@ -16710,6 +16710,7 @@
 	patches.suse/cgroup-cgroup-Honor-caller-s-cgroup-NS-when-resolving-cgroup-id.patch
 	patches.suse/cgroup-Homogenize-cgroup_get_from_id-return-value.patch
 	patches.suse/cgroup-cpuset-Enable-update_tasks_cpumask-on-top_cpuset.patch
+	patches.suse/cgroup-Make-cgroup_get_from_id-prettier.patch
 	patches.suse/livepatch-fix-race-between-fork-and-KLP-transition.patch
 	patches.suse/livepatch-Add-a-missing-newline-character-in-klp_mod.patch
 	patches.suse/kbuild-remove-the-target-in-signal-traps-when-interr.patch