From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 7F42774E0E; Tue, 6 Feb 2024 04:20:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707193216; cv=none; b=cKrZdiYQul5iUH68Zge+DGrfOyue1L+n5tMX71iszAJoP6cLTqEojR5gqtnLj1x2nIMrQ7C29QXSIKhZzRgGRCoQzcNWbVw63xC2nZJnp8xk/EnBJMkD8AdRJ5huXli/xf0mMv30LWH2QlHSphJUhEjYADgr3FFQiiu63HgIF8o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707193216; c=relaxed/simple; bh=v2eV89CFfg0ysp6EkHVTL96Fg1zaUIzw2XEMoAZm9IU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=klojETWzc0W4Njot3rERkkGQVgSyn6GUlut6P+PpiEd1HA6gWOqTuO/C4iLs6+y6L+9V4ayJngM7RwVVcmfQ2t+vJt4iclJcQFtrHSKDlc+TmJAaroUrgLWY0NmaZ4+lvKyw2sfyG9osixoBu+94Hk6pXuqUUcbn/a1Z+6Wfh6o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=QsZRrd1H; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="QsZRrd1H" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=8KnBD4rHlGntZQoBsKk3YytjdSLLdJZ0CNvsOChcWKY=; b=QsZRrd1HhHlHz06X66uZZdqjLo 1+rrPAIvCkAAJicO7CBx5oJZBvt1/VlxVYJFQ9ewI/sAlcGLZsJ83g+tZpP41dzF9OaMLI6KpM9im atfaWBSSAn/MWNpj9QqA3/ZZp+RG4J+vSne+7YWKd7DsX8+/dcj68yXltM/tPC6gawnHsPy80ll74 MGelLAYtiPlBRJF6xcsvRXTxAUAyvWawp0I9p7M/LcJChVxjh3/fdId8UiF5X+Dana6FI7YEYLopk jt3O7jAimwRImUScVUyDcQsXpfs/zZ7ALi4qFfPGWkf+i0orGluaGXP98zTFWugC+asTTjgjNJRwL /IlzbF8g==; Received: from [50.53.50.0] (helo=[192.168.254.15]) by bombadil.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1rXCwN-0000000603T-0d86; Tue, 06 Feb 2024 04:20:11 +0000 Message-ID: Date: Mon, 5 Feb 2024 20:20:10 -0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/6] fs: FS_IOC_GETSYSFSNAME Content-Language: en-US To: dsterba@suse.cz, Kent Overstreet Cc: "Darrick J. Wong" , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, Christian Brauner , Jan Kara , Dave Chinner , Theodore Ts'o , Josef Bacik References: <20240205200529.546646-1-kent.overstreet@linux.dev> <20240205200529.546646-5-kent.overstreet@linux.dev> <20240205222732.GO616564@frogsfrogsfrogs> <7si54ajkdqbauf2w64xnzfdglkokifgsjptmkxwdhgymxpk353@zf6nfn53manb> <20240206013931.GK355@twin.jikos.cz> From: Randy Dunlap In-Reply-To: <20240206013931.GK355@twin.jikos.cz> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/5/24 17:39, David Sterba wrote: > On Mon, Feb 05, 2024 at 05:43:37PM -0500, Kent Overstreet wrote: >> On Mon, Feb 05, 2024 at 02:27:32PM -0800, Darrick J. Wong wrote: >>> On Mon, Feb 05, 2024 at 03:05:15PM -0500, Kent Overstreet wrote: >>>> @@ -231,6 +235,7 @@ struct fsxattr { >>>> #define FS_IOC_SETFSLABEL _IOW(0x94, 50, char[FSLABEL_MAX]) >>>> #define FS_IOC_GETFSUUID _IOR(0x94, 51, struct fsuuid2) >>>> #define FS_IOC_SETFSUUID _IOW(0x94, 52, struct fsuuid2) >>>> +#define FS_IOC_GETFSSYSFSNAME _IOR(0x94, 53, struct fssysfsname) >>> >>> 0x94 is btrfs, don't add things to their "name" space. >> >> Can we please document this somewhere!? >> >> What, dare I ask, is the "namespace" I should be using? > > Grep for _IOCTL_MAGIC in include/uapi: > > uapi/linux/aspeed-lpc-ctrl.h:#define __ASPEED_LPC_CTRL_IOCTL_MAGIC 0xb2 > uapi/linux/aspeed-p2a-ctrl.h:#define __ASPEED_P2A_CTRL_IOCTL_MAGIC 0xb3 > uapi/linux/bt-bmc.h:#define __BT_BMC_IOCTL_MAGIC 0xb1 > uapi/linux/btrfs.h:#define BTRFS_IOCTL_MAGIC 0x94 > uapi/linux/f2fs.h:#define F2FS_IOCTL_MAGIC 0xf5 > uapi/linux/ipmi_bmc.h:#define __IPMI_BMC_IOCTL_MAGIC 0xB1 > uapi/linux/pfrut.h:#define PFRUT_IOCTL_MAGIC 0xEE > uapi/rdma/rdma_user_ioctl.h:#define IB_IOCTL_MAGIC RDMA_IOCTL_MAGIC > uapi/rdma/rdma_user_ioctl_cmds.h:#define RDMA_IOCTL_MAGIC 0x1b > > The label ioctls inherited the 0x94 namespace for backward > compatibility but as already said, it's the private namespace of btrfs. > or more generally, see Documentation/userspace-api/ioctl/ioctl-number.rst. For 0x94, it says: 0x94 all fs/btrfs/ioctl.h Btrfs filesystem and linux/fs.h some lifted to vfs/generic -- #Randy