From patchwork Wed May 9 16:04:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Sandeen X-Patchwork-Id: 10389897 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 58B0B60318 for ; Wed, 9 May 2018 16:04:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 46F05251F4 for ; Wed, 9 May 2018 16:04:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3ACD928455; Wed, 9 May 2018 16:04:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 96E5E251F4 for ; Wed, 9 May 2018 16:04:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965237AbeEIQEH (ORCPT ); Wed, 9 May 2018 12:04:07 -0400 Received: from sandeen.net ([63.231.237.45]:46626 "EHLO sandeen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935151AbeEIQEF (ORCPT ); Wed, 9 May 2018 12:04:05 -0400 Received: from Liberator-5.local (liberator [10.0.0.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by sandeen.net (Postfix) with ESMTPSA id 717924CDD43; Wed, 9 May 2018 11:02:39 -0500 (CDT) Subject: [PATCH 2/2] man2: New page documenting filesystem get/set label ioctls To: Eric Sandeen , fsdevel , "linux-btrfs@vger.kernel.org" , Linux API , "Michael Kerrisk (man-pages)" References: From: Eric Sandeen Openpgp: preference=signencrypt Autocrypt: addr=sandeen@sandeen.net; prefer-encrypt=mutual; keydata= xsFNBE6x99QBEADMR+yNFBc1Y5avoUhzI/sdR9ANwznsNpiCtZlaO4pIWvqQJCjBzp96cpCs nQZV32nqJBYnDpBDITBqTa/EF+IrHx8gKq8TaSBLHUq2ju2gJJLfBoL7V3807PQcI18YzkF+ WL05ODFQ2cemDhx5uLghHEeOxuGj+1AI+kh/FCzMedHc6k87Yu2ZuaWF+Gh1W2ix6hikRJmQ vj5BEeAx7xKkyBhzdbNIbbjV/iGi9b26B/dNcyd5w2My2gxMtxaiP7q5b6GM2rsQklHP8FtW ZiYO7jsg/qIppR1C6Zr5jK1GQlMUIclYFeBbKggJ9mSwXJH7MIftilGQ8KDvNuV5AbkronGC sEEHj2khs7GfVv4pmUUHf1MRIvV0x3WJkpmhuZaYg8AdJlyGKgp+TQ7B+wCjNTdVqMI1vDk2 BS6Rg851ay7AypbCPx2w4d8jIkQEgNjACHVDU89PNKAjScK1aTnW+HNUqg9BliCvuX5g4z2j gJBs57loTWAGe2Ve3cMy3VoQ40Wt3yKK0Eno8jfgzgb48wyycINZgnseMRhxc2c8hd51tftK LKhPj4c7uqjnBjrgOVaVBupGUmvLiePlnW56zJZ51BR5igWnILeOJ1ZIcf7KsaHyE6B1mG+X dmYtjDhjf3NAcoBWJuj8euxMB6TcQN2MrSXy5wSKaw40evooGwARAQABzSVFcmljIFIuIFNh bmRlZW4gPHNhbmRlZW5Ac2FuZGVlbi5uZXQ+wsF7BBMBAgAlAhsDBgsJCAcDAgYVCAIJCgsE FgIDAQIeAQIXgAUCUzMzbAIZAQAKCRAgrhaS4T3e4Fr7D/wO+fenqVvHjq21SCjDCrt8HdVj aJ28B1SqSU2toxyg5I160GllAxEHpLFGdbFAhQfBtnmlY9eMjwmJb0sCIrkrB6XNPSPA/B2B UPISh0z2odJv35/euJF71qIFgWzp2czJHkHWwVZaZpMWWNvsLIroXoR+uA9c2V1hQFVAJZyk EE4xzfm1+oVtjIC12B9tTCuS00pY3AUy21yzNowT6SSk7HAzmtG/PJ/uSB5wEkwldB6jVs2A sjOg1wMwVvh/JHilsQg4HSmDfObmZj1d0RWlMWcUE7csRnCE0ZWBMp/ttTn+oosioGa09HAS 9jAnauznmYg43oQ5Akd8iQRxz5I58F/+JsdKvWiyrPDfYZtFS+UIgWD7x+mHBZ53Qjazszox gjwO9ehZpwUQxBm4I0lPDAKw3HJA+GwwiubTSlq5PS3P7QoCjaV8llH1bNFZMz2o8wPANiDx 5FHgpRVgwLHakoCU1Gc+LXHXBzDXt7Cj02WYHdFzMm2hXaslRdhNGowLo1SXZFXa41KGTlNe 4di53y9CK5ynV0z+YUa+5LR6RdHrHtgywdKnjeWdqhoVpsWIeORtwWGX8evNOiKJ7j0RsHha WrePTubr5nuYTDsQqgc2r4aBIOpeSRR2brlT/UE3wGgy9LY78L4EwPR0MzzecfE1Ws60iSqw Pu3vhb7h3c7BTQROsffUARAA0DrUifTrXQzqxO8aiQOC5p9Tz25Np/Tfpv1rofOwL8VPBMvJ X4P5l1V2yd70MZRUVgjmCydEyxLJ6G2YyHO2IZTEajUY0Up+b3ErOpLpZwhvgWatjifpj6bB SKuDXeThqFdkphF5kAmgfVAIkan5SxWK3+S0V2F/oxstIViBhMhDwI6XsRlnVBoLLYcEilxA 2FlRUS7MOZGmRJkRtdGD5koVZSM6xVZQSmfEBaYQ/WJBGJQdPy94nnlAVn3lH3+N7pXvNUuC GV+t4YUt3tLcRuIpYBCOWlc7bpgeCps5Xa0dIZgJ8Louu6OBJ5vVXjPxTlkFdT0S0/uerCG5 1u8p6sGRLnUeAUGkQfIUqGUjW2rHaXgWNvzOV6i3tf9YaiXKl3avFaNW1kKBs0T5M1cnlWZU Utl6k04lz5OjoNY9J/bGyV3DSlkblXRMK87iLYQSrcV6cFz9PRl4vW1LGff3xRQHngeN5fPx ze8X5NE3hb+SSwyMSEqJxhVTXJVfQWWW0dQxP7HNwqmOWYF/6m+1gK/Y2gY3jAQnsWTru4RV TZGnKwEPmOCpSUvsTRXsVHgsWJ70qd0yOSjWuiv4b8vmD3+QFgyvCBxPMdP3xsxN5etheLMO gRwWpLn6yNFq/xtgs+ECgG+gR78yXQyA7iCs5tFs2OrMqV5juSMGmn0kxJUAEQEAAcLBXwQY AQIACQUCTrH31AIbDAAKCRAgrhaS4T3e4BKwD/0ZOOmUNOZCSOLAMjZx3mtYtjYgfUNKi0ki YPveGoRWTqbis8UitPtNrG4XxgzLOijSdOEzQwkdOIp/QnZhGNssMejCnsluK0GQd+RkFVWN mcQT78hBeGcnEMAXZKq7bkIKzvc06GFmkMbX/gAl6DiNGv0UNAX+5FYh+ucCJZSyAp3sA+9/ LKjxnTedX0aygXA6rkpX0Y0FvN/9dfm47+LGq7WAqBOyYTU3E6/+Z72bZoG/cG7ANLxcPool LOrU43oqFnD8QwcN56y4VfFj3/jDF2MX3xu4v2OjglVjMEYHTCxP3mpxesGHuqOit/FR+mF0 MP9JGfj6x+bj/9JMBtCW1bY/aPeMdPGTJvXjGtOVYblGZrSjXRn5++Uuy36CvkcrjuziSDG+ JEexGxczWwN4mrOQWhMT5Jyb+18CO+CWxJfHaYXiLEW7dI1AynL4jjn4W0MSiXpWDUw+fsBO Pk6ah10C4+R1Jc7dyUsKksMfvvhRX1hTIXhth85H16706bneTayZBhlZ/hK18uqTX+s0onG/ m1F3vYvdlE4p2ts1mmixMF7KajN9/E5RQtiSArvKTbfsB6Two4MthIuLuf+M0mI4gPl9SPlf fWCYVPhaU9o83y1KFbD/+lh1pjP7bEu/YudBvz7F2Myjh4/9GUAijrCTNeDTDAgvIJDjXuLX pA== Message-ID: <708b8e2a-2bc2-df38-ec9c-c605203052b5@sandeen.net> Date: Wed, 9 May 2018 11:04:03 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This documents the proposed new vfs-level ioctls which can get or set a mounted filesytem's label. Signed-off-by: Eric Sandeen --- btrfs folks, please verify that this accurately describes your current behavior, thanks. diff --git a/man2/ioctl_fslabel.2 b/man2/ioctl_fslabel.2 new file mode 100644 index 0000000..150aa53 --- /dev/null +++ b/man2/ioctl_fslabel.2 @@ -0,0 +1,83 @@ +.\" Copyright (c) 2018, Red Hat, Inc. All rights reserved. +.\" +.\" %%%LICENSE_START(GPLv2+_DOC_FULL) +.\" This is free documentation; you can redistribute it and/or +.\" modify it under the terms of the GNU General Public License as +.\" published by the Free Software Foundation; either version 2 of +.\" the License, or (at your option) any later version. +.\" +.\" The GNU General Public License's references to "object code" +.\" and "executables" are to be interpreted as the output of any +.\" document formatting or typesetting system, including +.\" intermediate and printed output. +.\" +.\" This manual is distributed in the hope that it will be useful, +.\" but WITHOUT ANY WARRANTY; without even the implied warranty of +.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +.\" GNU General Public License for more details. +.\" +.\" You should have received a copy of the GNU General Public +.\" License along with this manual; if not, see +.\" . +.\" %%%LICENSE_END +.TH IOCTL-FSLABEL 2 2018-05-02 "Linux" "Linux Programmer's Manual" +.SH NAME +ioctl_fslabel \- get or set a filesystem label +.SH SYNOPSIS +.br +.B #include +.br +.B #include +.sp +.BI "int ioctl(int " fd ", FS_IOC_GETFSLABEL, char " label [FSLABEL_MAX]); +.br +.BI "int ioctl(int " fd ", FS_IOC_SETFSLABEL, char " label [FSLABEL_MAX]); +.SH DESCRIPTION +If a filesystem supports online label manipulation, these +.BR ioctl (2) +operations can be used to get or set the filesystem label for the filesystem +on which +.B fd +resides. +.SH RETURN VALUE +On success zero is returned. On error, \-1 is returned, and +.I errno +is set to indicate the error. +.PP +.SH ERRORS +Error codes can be one of, but are not limited to, the following: +.TP +.B EINVAL +The specified label exceeds the maximum label length for the filesystem. +.TP +.B ENOTTY +This can appear if the filesystem does not support online label manipulation. +.TP +.B EPERM +The calling process does not have sufficient permissions to set the label. +.TP +.B EFAULT +.I label +references an inaccessible memory area. +.SH VERSIONS +These ioctl operations first appeared in Linux 4.18. +They were previously known as +.B BTRFS_IOC_GET_FSLABEL +and +.B BTRFS_IOC_SET_FSLABEL +and were private to Btrfs. +.SH CONFORMING TO +This API is Linux-specific. +.SH NOTES +The maximum string length for this interface is +.BR FSLABEL_MAX , +including the terminating null byte (\(aq\\0\(aq). +Filesystems have differing maximum label lengths, which may or +may not include the terminating null. The string provided to +.B FS_IOC_SETFSLABEL +must always be null-terminated, and the string returned by +.B FS_IOC_GETFSLABEL +will always be null-terminated. +.SH SEE ALSO +.BR ioctl (2), +.BR blkid (8) diff --git a/man2/ioctl_getfslabel.2 b/man2/ioctl_getfslabel.2 new file mode 100644 index 0000000..bfa8dca --- /dev/null +++ b/man2/ioctl_getfslabel.2 @@ -0,0 +1 @@ +.so man2/ioctl_fslabel.2 diff --git a/man2/ioctl_setfslabel.2 b/man2/ioctl_setfslabel.2 new file mode 100644 index 0000000..bfa8dca --- /dev/null +++ b/man2/ioctl_setfslabel.2 @@ -0,0 +1 @@ +.so man2/ioctl_fslabel.2