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From: "Michal Koutný" <mkoutny@suse.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	cgroups@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>, Tejun Heo <tj@kernel.org>,
	Zefan Li <lizefan.x@bytedance.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Dave Chinner <dchinner@redhat.com>,
	Rik van Riel <riel@surriel.com>, Jiri Wiesner <jwiesner@suse.de>
Subject: [RFC PATCH 1/3] cgroup: Drop unused function for cgroup_path
Date: Tue,  2 May 2023 15:38:45 +0200	[thread overview]
Message-ID: <20230502133847.14570-2-mkoutny@suse.com> (raw)
In-Reply-To: <20230502133847.14570-1-mkoutny@suse.com>

There is no current user and there are alternative methods to obtain
task's cgroup path.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
 kernel/cgroup/cgroup.c | 39 ---------------------------------------
 1 file changed, 39 deletions(-)

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 625d7483951c..55e5f0110e3b 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2378,45 +2378,6 @@ int cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen,
 }
 EXPORT_SYMBOL_GPL(cgroup_path_ns);
 
-/**
- * task_cgroup_path - cgroup path of a task in the first cgroup hierarchy
- * @task: target task
- * @buf: the buffer to write the path into
- * @buflen: the length of the buffer
- *
- * Determine @task's cgroup on the first (the one with the lowest non-zero
- * hierarchy_id) cgroup hierarchy and copy its path into @buf.  This
- * function grabs cgroup_mutex and shouldn't be used inside locks used by
- * cgroup controller callbacks.
- *
- * Return value is the same as kernfs_path().
- */
-int task_cgroup_path(struct task_struct *task, char *buf, size_t buflen)
-{
-	struct cgroup_root *root;
-	struct cgroup *cgrp;
-	int hierarchy_id = 1;
-	int ret;
-
-	cgroup_lock();
-	spin_lock_irq(&css_set_lock);
-
-	root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
-
-	if (root) {
-		cgrp = task_cgroup_from_root(task, root);
-		ret = cgroup_path_ns_locked(cgrp, buf, buflen, &init_cgroup_ns);
-	} else {
-		/* if no hierarchy exists, everyone is in "/" */
-		ret = strscpy(buf, "/", buflen);
-	}
-
-	spin_unlock_irq(&css_set_lock);
-	cgroup_unlock();
-	return ret;
-}
-EXPORT_SYMBOL_GPL(task_cgroup_path);
-
 /**
  * cgroup_attach_lock - Lock for ->attach()
  * @lock_threadgroup: whether to down_write cgroup_threadgroup_rwsem
-- 
2.40.1


  reply	other threads:[~2023-05-02 13:39 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-02 13:38 [RFC PATCH 0/3] Rework locking when rendering mountinfo cgroup paths Michal Koutný
2023-05-02 13:38 ` Michal Koutný [this message]
2023-05-02 19:58   ` [RFC PATCH 1/3] cgroup: Drop unused function for cgroup_path Waiman Long
2023-05-02 13:38 ` [RFC PATCH 2/3] cgroup: Rely on namespace_sem in current_cgns_cgroup_from_root explicitly Michal Koutný
2023-05-02 19:50   ` Waiman Long
2023-05-23 10:42   ` Christian Brauner
2023-05-23 19:12     ` Tejun Heo
2023-05-02 13:38 ` [RFC PATCH 3/3] cgroup: Do not take css_set_lock in cgroup_show_path Michal Koutný
2023-05-02 19:56   ` Waiman Long
2023-05-05 15:45   ` Tejun Heo
2023-05-05 17:32     ` Michal Koutný
2023-05-05 18:17       ` Tejun Heo
2023-05-09 10:34         ` Michal Koutný
2023-05-22 20:55           ` Tejun Heo
2023-05-23 12:09 ` [RFC PATCH 0/3] Rework locking when rendering mountinfo cgroup paths Christian Brauner

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