From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4F1417EC; Mon, 11 Mar 2024 01:42:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.190 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710121329; cv=none; b=HVivF2l1ygHzbGke/tgq8MFaQ9l2AlhyRP8ArkKpdk/vDMCta7WFaSs+Uz26sOUTFn6OZOSKBZvz1Il3gVYhAv522fsJ6hhT2E0IA0EPLoidyaRiz61S1ymg5C7LpY/mocdkSn4rAIdWQSIeaPrGb7Wir3SjNEtUjDUocQbMLwA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710121329; c=relaxed/simple; bh=tlGY4WhXXjsLLH1CJl1ckUpvArPPoMe47vLaJrYpYlc=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=dJOJV2zgk0y/v9lQPkQma88hw0EKap76panWsJAa7TGOQaz5TkKwx0nC/umvhvceyLZcyMQhgyf+4Zbr2Z6q8fjUax5JaJ/q+EtxitZzT27w6VewqCBU9KwMBnQy+1mfrKwcfU+Nim+j6YDvN1bHC2lthsCM828KUZZtr7ZktZM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.190 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.17]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4TtKGQ386nz1xqhQ; Mon, 11 Mar 2024 09:40:14 +0800 (CST) Received: from dggpeml500022.china.huawei.com (unknown [7.185.36.66]) by mail.maildlp.com (Postfix) with ESMTPS id 2CDC41A0172; Mon, 11 Mar 2024 09:41:57 +0800 (CST) Received: from [10.67.111.104] (10.67.111.104) by dggpeml500022.china.huawei.com (7.185.36.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 11 Mar 2024 09:41:56 +0800 Message-ID: <4ddd2362-2383-434a-b4b0-2075072572d6@huawei.com> Date: Mon, 11 Mar 2024 09:41:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] bcachefs: chardev: make bch_chardev_class constant To: "Ricardo B. Marliere" , Kent Overstreet , Brian Foster CC: , , Greg Kroah-Hartman References: <20240308-bcachefs-v2-1-3e84c845055e@marliere.net> Content-Language: en-US From: Hongbo Li In-Reply-To: <20240308-bcachefs-v2-1-3e84c845055e@marliere.net> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggpeml500022.china.huawei.com (7.185.36.66) It's fine for me. On 2024/3/8 20:12, Ricardo B. Marliere wrote: > Since commit 43a7206b0963 ("driver core: class: make class_register() take > a const *"), the driver core allows for struct class to be in read-only > memory, so move the bch_chardev_class structure to be declared at build > time placing it into read-only memory, instead of having to be dynamically > allocated at boot time. Also, correctly clean up after failing paths in > bch2_chardev_init(). > > Cc: Hongbo Li > Cc: Greg Kroah-Hartman > Suggested-by: Greg Kroah-Hartman > Signed-off-by: Ricardo B. Marliere > --- > Changes in v2: > - Used "free the last thing" pattern in bch2_chardev_init(). > - Link to v1: https://lore.kernel.org/r/20240305-bcachefs-v1-1-436196e25729@marliere.net > --- > fs/bcachefs/chardev.c | 35 ++++++++++++++++++++++------------- > 1 file changed, 22 insertions(+), 13 deletions(-) > > diff --git a/fs/bcachefs/chardev.c b/fs/bcachefs/chardev.c > index 226b39c17667..dc09f547dae6 100644 > --- a/fs/bcachefs/chardev.c > +++ b/fs/bcachefs/chardev.c > @@ -940,7 +940,9 @@ static const struct file_operations bch_chardev_fops = { > }; > > static int bch_chardev_major; > -static struct class *bch_chardev_class; > +static const struct class bch_chardev_class = { > + .name = "bcachefs", > +}; > static struct device *bch_chardev; > > void bch2_fs_chardev_exit(struct bch_fs *c) > @@ -957,7 +959,7 @@ int bch2_fs_chardev_init(struct bch_fs *c) > if (c->minor < 0) > return c->minor; > > - c->chardev = device_create(bch_chardev_class, NULL, > + c->chardev = device_create(&bch_chardev_class, NULL, > MKDEV(bch_chardev_major, c->minor), c, > "bcachefs%u-ctl", c->minor); > if (IS_ERR(c->chardev)) > @@ -968,32 +970,39 @@ int bch2_fs_chardev_init(struct bch_fs *c) > > void bch2_chardev_exit(void) > { > - if (!IS_ERR_OR_NULL(bch_chardev_class)) > - device_destroy(bch_chardev_class, > - MKDEV(bch_chardev_major, U8_MAX)); > - if (!IS_ERR_OR_NULL(bch_chardev_class)) > - class_destroy(bch_chardev_class); > + device_destroy(&bch_chardev_class, MKDEV(bch_chardev_major, U8_MAX)); > + class_unregister(&bch_chardev_class); > if (bch_chardev_major > 0) > unregister_chrdev(bch_chardev_major, "bcachefs"); > } > > int __init bch2_chardev_init(void) > { > + int ret; > + > bch_chardev_major = register_chrdev(0, "bcachefs-ctl", &bch_chardev_fops); > if (bch_chardev_major < 0) > return bch_chardev_major; > > - bch_chardev_class = class_create("bcachefs"); > - if (IS_ERR(bch_chardev_class)) > - return PTR_ERR(bch_chardev_class); > + ret = class_register(&bch_chardev_class); > + if (ret) > + goto major_out; > > - bch_chardev = device_create(bch_chardev_class, NULL, > + bch_chardev = device_create(&bch_chardev_class, NULL, > MKDEV(bch_chardev_major, U8_MAX), > NULL, "bcachefs-ctl"); > - if (IS_ERR(bch_chardev)) > - return PTR_ERR(bch_chardev); > + if (IS_ERR(bch_chardev)) { > + ret = PTR_ERR(bch_chardev); > + goto class_out; > + } > > return 0; > + > +class_out: > + class_unregister(&bch_chardev_class); > +major_out: > + unregister_chrdev(bch_chardev_major, "bcachefs-ctl"); > + return ret; > } > > #endif /* NO_BCACHEFS_CHARDEV */ > > --- > base-commit: 90d35da658da8cff0d4ecbb5113f5fac9d00eb72 > change-id: 20240305-bcachefs-27a4bb8b9f4f > > Best regards,