From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934998AbcLTQNX (ORCPT ); Tue, 20 Dec 2016 11:13:23 -0500 Received: from mail-yb0-f193.google.com ([209.85.213.193]:35451 "EHLO mail-yb0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933675AbcLTQMc (ORCPT ); Tue, 20 Dec 2016 11:12:32 -0500 From: Tejun Heo To: gregkh@linuxfoundation.org, lizefan@huawei.com, hannes@cmpxchg.org Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, kernel-team@fb.com, Tejun Heo Subject: [PATCH 3/5] cgroup add cftype->open/release() callbacks Date: Tue, 20 Dec 2016 11:12:20 -0500 Message-Id: <20161220161222.15234-4-tj@kernel.org> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20161220161222.15234-1-tj@kernel.org> References: <20161220161222.15234-1-tj@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Pipe the newly added kernfs->open/release() callbacks through cftype. While at it, as cleanup operations now can be performed from ->release() instead of ->seq_stop(), make the latter optional. Signed-off-by: Tejun Heo --- include/linux/cgroup-defs.h | 3 +++ kernel/cgroup.c | 24 +++++++++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 861b467..8a916dc 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -388,6 +388,9 @@ struct cftype { struct list_head node; /* anchored at ss->cfts */ struct kernfs_ops *kf_ops; + int (*open)(struct kernfs_open_file *of); + void (*release)(struct kernfs_open_file *of); + /* * read_u64() is a shortcut for the common case of returning a * single integer. Use it in place of read() diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 2ee9ec3..87167e4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -3503,6 +3503,23 @@ static int cgroup_events_show(struct seq_file *seq, void *v) return 0; } +static int cgroup_file_open(struct kernfs_open_file *of) +{ + struct cftype *cft = of->kn->priv; + + if (cft->open) + return cft->open(of); + return 0; +} + +static void cgroup_file_release(struct kernfs_open_file *of) +{ + struct cftype *cft = of->kn->priv; + + if (cft->release) + cft->release(of); +} + static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { @@ -3553,7 +3570,8 @@ static void *cgroup_seqfile_next(struct seq_file *seq, void *v, loff_t *ppos) static void cgroup_seqfile_stop(struct seq_file *seq, void *v) { - seq_cft(seq)->seq_stop(seq, v); + if (seq_cft(seq)->seq_stop) + seq_cft(seq)->seq_stop(seq, v); } static int cgroup_seqfile_show(struct seq_file *m, void *arg) @@ -3575,12 +3593,16 @@ static int cgroup_seqfile_show(struct seq_file *m, void *arg) static struct kernfs_ops cgroup_kf_single_ops = { .atomic_write_len = PAGE_SIZE, + .open = cgroup_file_open, + .release = cgroup_file_release, .write = cgroup_file_write, .seq_show = cgroup_seqfile_show, }; static struct kernfs_ops cgroup_kf_ops = { .atomic_write_len = PAGE_SIZE, + .open = cgroup_file_open, + .release = cgroup_file_release, .write = cgroup_file_write, .seq_start = cgroup_seqfile_start, .seq_next = cgroup_seqfile_next, -- 2.9.3