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From: Tejun Heo <tj@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Chengming Zhou <zhouchengming@bytedance.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Imran Khan <imran.f.khan@oracle.com>,
	kernel-team@fb.com, Tejun Heo <tj@kernel.org>
Subject: [PATCH 3/9] kernfs: Refactor kernfs_get_open_node()
Date: Sat, 27 Aug 2022 19:04:34 -1000	[thread overview]
Message-ID: <20220828050440.734579-4-tj@kernel.org> (raw)
In-Reply-To: <20220828050440.734579-1-tj@kernel.org>

Factor out commont part. This is cleaner and should help with future
changes. No functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com>
---
 fs/kernfs/file.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 6437f7c7162d..7060a2a714b8 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -554,31 +554,28 @@ static int kernfs_fop_mmap(struct file *file, struct vm_area_struct *vma)
 static int kernfs_get_open_node(struct kernfs_node *kn,
 				struct kernfs_open_file *of)
 {
-	struct kernfs_open_node *on, *new_on = NULL;
+	struct kernfs_open_node *on;
 	struct mutex *mutex;
 
 	mutex = kernfs_open_file_mutex_lock(kn);
 	on = kernfs_deref_open_node_locked(kn);
 
-	if (on) {
-		list_add_tail(&of->list, &on->files);
-		mutex_unlock(mutex);
-		return 0;
-	} else {
+	if (!on) {
 		/* not there, initialize a new one */
-		new_on = kmalloc(sizeof(*new_on), GFP_KERNEL);
-		if (!new_on) {
+		on = kmalloc(sizeof(*on), GFP_KERNEL);
+		if (!on) {
 			mutex_unlock(mutex);
 			return -ENOMEM;
 		}
-		atomic_set(&new_on->event, 1);
-		init_waitqueue_head(&new_on->poll);
-		INIT_LIST_HEAD(&new_on->files);
-		list_add_tail(&of->list, &new_on->files);
-		rcu_assign_pointer(kn->attr.open, new_on);
+		atomic_set(&on->event, 1);
+		init_waitqueue_head(&on->poll);
+		INIT_LIST_HEAD(&on->files);
+		rcu_assign_pointer(kn->attr.open, on);
 	}
-	mutex_unlock(mutex);
 
+	list_add_tail(&of->list, &on->files);
+
+	mutex_unlock(mutex);
 	return 0;
 }
 
-- 
2.37.2


  parent reply	other threads:[~2022-08-28  5:05 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-28  5:04 [PATCHSET v2 for-6.1] kernfs, cgroup: implement kernfs_show() and cgroup_file_show() Tejun Heo
2022-08-28  5:04 ` [PATCH 1/9] kernfs: Simply by replacing kernfs_deref_open_node() with of_on() Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 2/9] kernfs: Drop unnecessary "mutex" local variable initialization Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` Tejun Heo [this message]
2022-09-09 14:00   ` [tip: sched/psi] kernfs: Refactor kernfs_get_open_node() tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 4/9] kernfs: Skip kernfs_drain_open_files() more aggressively Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 5/9] kernfs: Improve kernfs_drain() and always call on removal Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 6/9] kernfs: Add KERNFS_REMOVING flags Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 7/9] kernfs: Factor out kernfs_activate_one() Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 8/9] kernfs: Implement kernfs_show() Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  5:04 ` [PATCH 9/9] cgroup: Implement cgroup_file_show() Tejun Heo
2022-09-09 14:00   ` [tip: sched/psi] " tip-bot2 for Tejun Heo
2022-08-28  8:33 ` [PATCHSET v2 for-6.1] kernfs, cgroup: implement kernfs_show() and cgroup_file_show() Chengming Zhou

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