From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (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 07D7E1B967; Fri, 22 Mar 2024 06:52:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711090352; cv=none; b=Ui/FpEeajAuaDkL+zw6dfV9iSgUMeT9Ig7sDHaEnMTB/zv78CuJjF9G25MgZzMWWgqhk/EZNf0YKc1cO56ZFQHslzXLuc0JTX4bllydJIPFS5acQ2V4UZXfsbztJJVkx4aOAXBVrtem8ebzcu9W57y20dG5EZeoIdZV9zT+fAs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711090352; c=relaxed/simple; bh=bC0VwAMmjjaPlPp/AY14cXKkkFDIEQiIYzG/xloaQLY=; h=Subject:To:Cc:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=ZAX87Ml3D/ELoxFlNxvRd7++ZNUgKC+K4D8QbcZFSxq3f+6jkbM7wzzTr2Fl0P3HSi/p76a/T5qs4iezAsTgMxwM+7hQgPGqhZ28Y4JJlf6n+KCTCvN/Em42TfinQXK07wxccJYWxTN1V2La/CwACywzeeKUCZCwApvmSyN9pUE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.216]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4V1CgG6b9Fz4f3m6f; Fri, 22 Mar 2024 14:52:10 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.112]) by mail.maildlp.com (Postfix) with ESMTP id E008A1A0199; Fri, 22 Mar 2024 14:52:18 +0800 (CST) Received: from [10.174.176.73] (unknown [10.174.176.73]) by APP1 (Coremail) with SMTP id cCh0CgBHZQ6hKv1l5bTaHg--.60999S3; Fri, 22 Mar 2024 14:52:18 +0800 (CST) Subject: Re: [RFC v4 linux-next 19/19] fs & block: remove bdev->bd_inode To: Al Viro , Yu Kuai Cc: Jan Kara , Christoph Hellwig , brauner@kernel.org, axboe@kernel.dk, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, "yukuai (C)" References: <20240317213847.GD10665@lst.de> <022204e6-c387-b4b2-5982-970fd1ed5b5b@huaweicloud.com> <20240318013208.GA23711@lst.de> <5c231b60-a2bf-383e-e641-371e7e57da67@huaweicloud.com> <20240318232245.GA17831@lst.de> <20240321112737.33xuxfttrahtvbej@quack3> <240b78df-257e-a97c-31ff-a8b1b1882e80@huaweicloud.com> <20240322063718.GC3404528@ZenIV> <20240322063955.GM538574@ZenIV> From: Yu Kuai Message-ID: <170c544c-164e-368c-474a-74ae4055d55f@huaweicloud.com> Date: Fri, 22 Mar 2024 14:52:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240322063955.GM538574@ZenIV> Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgBHZQ6hKv1l5bTaHg--.60999S3 X-Coremail-Antispam: 1UD129KBjvdXoW7XF45GFW7ZrW7Gryruw1Dtrb_yoWDuFX_XF y8uF9Yyw1UXFn5uan0kFyrJryqqw1DZrW3t39xX34rXwn3Xas3uF1rC34xAF98Gw4UKrsx Cr1rXFW5XryxtjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUb3AFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2IYs7xG 6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8w A2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j 6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcVAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2kI c2xKxwCYjI0SjxkI62AI1cAE67vIY487MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4 AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE 17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMI IF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_WFyUJVCq 3wCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCT nIWIevJa73UjIFyTuYvjfUoOJ5UUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ Hi, ÔÚ 2024/03/22 14:39, Al Viro дµÀ: > On Fri, Mar 22, 2024 at 06:37:18AM +0000, Al Viro wrote: >> On Thu, Mar 21, 2024 at 08:15:06PM +0800, Yu Kuai wrote: >> >>>> blkdev_iomap_begin() etc. may be an arbitrary filesystem block device >>>> inode. But why can't you use I_BDEV(inode->i_mapping->host) to get to the >>>> block device instead of your file_bdev(inode->i_private)? I don't see any >>>> advantage in stashing away that special bdev_file into inode->i_private but >>>> perhaps I'm missing something... >>>> >>> >>> Because we're goning to remove the 'block_device' from iomap and >>> buffer_head, and replace it with a 'bdev_file'. >> >> What of that? file_inode(file)->f_mapping->host will give you bdevfs inode >> just fine... > > file->f_mapping->host, obviously - sorry. > . Yes, we already get bdev_inode this way, and use it in blkdev_iomap_begin() and blkdev_get_block(), the problem is that if we want to let iomap and buffer_head to use bdev_file for raw block fops as well, we need a 'bdev_file' somehow. Thanks, Kuai >