From patchwork Thu Oct 3 10:26:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Kent X-Patchwork-Id: 11172467 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5FE0014DB for ; Thu, 3 Oct 2019 10:26:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A66321D71 for ; Thu, 3 Oct 2019 10:26:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728689AbfJCK03 (ORCPT ); Thu, 3 Oct 2019 06:26:29 -0400 Received: from icp-osb-irony-out7.external.iinet.net.au ([203.59.1.107]:43057 "EHLO icp-osb-irony-out7.external.iinet.net.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727657AbfJCK03 (ORCPT ); Thu, 3 Oct 2019 06:26:29 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2AiAADHy5Vd/7q70HYNWRwBAQEEAQEMBAEBgVQGAQELAYQ5hCKPKgMGgRGKGo8xgXsJAQEBAQEBAQEBNwEBhDsDAgKCaDUIDgIMAQEBBAEBAQEBBQMBhViGGgIBAyMETQUQGA0CJgICRxAGE4UZrgx1fzMaiieBDCgBgWSKQXiBB4EQNIMdh1GCWASPMDeGOUOWVIItlTMMgi2LZgOLHC2ECoswmW8DggxNLgqDJ1CQRmeOSSuCJwEB X-IPAS-Result: A2AiAADHy5Vd/7q70HYNWRwBAQEEAQEMBAEBgVQGAQELAYQ5hCKPKgMGgRGKGo8xgXsJAQEBAQEBAQEBNwEBhDsDAgKCaDUIDgIMAQEBBAEBAQEBBQMBhViGGgIBAyMETQUQGA0CJgICRxAGE4UZrgx1fzMaiieBDCgBgWSKQXiBB4EQNIMdh1GCWASPMDeGOUOWVIItlTMMgi2LZgOLHC2ECoswmW8DggxNLgqDJ1CQRmeOSSuCJwEB X-IronPort-AV: E=Sophos;i="5.67,251,1566835200"; d="scan'208";a="207652925" Received: from unknown (HELO [192.168.1.222]) ([118.208.187.186]) by icp-osb-irony-out7.iinet.net.au with ESMTP; 03 Oct 2019 18:26:27 +0800 Subject: [PATCH v4 13/17] xfs: mount api - add xfs_reconfigure() From: Ian Kent To: linux-xfs Cc: Brian Foster , Eric Sandeen , David Howells , Dave Chinner , Al Viro Date: Thu, 03 Oct 2019 18:26:27 +0800 Message-ID: <157009838772.13858.3951542955676751036.stgit@fedora-28> In-Reply-To: <157009817203.13858.7783767645177567968.stgit@fedora-28> References: <157009817203.13858.7783767645177567968.stgit@fedora-28> User-Agent: StGit/unknown-version MIME-Version: 1.0 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Add the fs_context_operations method .reconfigure that performs remount validation as previously done by the super_operations .remount_fs method. An attempt has also been made to update the comment about options handling problems with mount(8) to reflect the current situation. Signed-off-by: Ian Kent --- fs/xfs/xfs_super.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index ddcf030cca7c..06f650fb3a8c 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1544,6 +1544,73 @@ xfs_fs_remount( return 0; } +/* + * There can be problems with options passed from mount(8) when + * only the mount point path is given. The options are a merge + * of options from the fstab, mtab of the current mount and options + * given on the command line. + * + * But this can't be relied upon to accurately reflect the current + * mount options. Consequently rejecting options that can't be + * changed on reconfigure could erronously cause a mount failure. + * + * Nowadays it should be possible to compare incoming options + * and return an error for options that differ from the current + * mount and can't be changed on reconfigure. + * + * But this still might not always be the case so for now continue + * to return success for every reconfigure request, and silently + * ignore all options that can't actually be changed. + * + * See the commit log entry of this change for a more detailed + * desription of the problem. + */ +STATIC int +xfs_reconfigure( + struct fs_context *fc) +{ + struct xfs_fs_context *ctx = fc->fs_private; + struct xfs_mount *mp = XFS_M(fc->root->d_sb); + struct xfs_mount *new_mp = fc->s_fs_info; + xfs_sb_t *sbp = &mp->m_sb; + int flags = fc->sb_flags; + int error; + + error = xfs_validate_params(new_mp, ctx, false); + if (error) + return error; + + /* inode32 -> inode64 */ + if ((mp->m_flags & XFS_MOUNT_SMALL_INUMS) && + !(new_mp->m_flags & XFS_MOUNT_SMALL_INUMS)) { + mp->m_flags &= ~XFS_MOUNT_SMALL_INUMS; + mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount); + } + + /* inode64 -> inode32 */ + if (!(mp->m_flags & XFS_MOUNT_SMALL_INUMS) && + (new_mp->m_flags & XFS_MOUNT_SMALL_INUMS)) { + mp->m_flags |= XFS_MOUNT_SMALL_INUMS; + mp->m_maxagi = xfs_set_inode_alloc(mp, sbp->sb_agcount); + } + + /* ro -> rw */ + if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(flags & SB_RDONLY)) { + error = xfs_remount_rw(mp); + if (error) + return error; + } + + /* rw -> ro */ + if (!(mp->m_flags & XFS_MOUNT_RDONLY) && (flags & SB_RDONLY)) { + error = xfs_remount_ro(mp); + if (error) + return error; + } + + return 0; +} + /* * Second stage of a freeze. The data is already frozen so we only * need to take care of the metadata. Once that's done sync the superblock @@ -2069,6 +2136,7 @@ static const struct super_operations xfs_super_operations = { static const struct fs_context_operations xfs_context_ops = { .parse_param = xfs_parse_param, .get_tree = xfs_get_tree, + .reconfigure = xfs_reconfigure, }; static struct file_system_type xfs_fs_type = {