From patchwork Wed Nov 6 09:15:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sascha Hauer X-Patchwork-Id: 11229699 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 1C955112B for ; Wed, 6 Nov 2019 09:15:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0345B2178F for ; Wed, 6 Nov 2019 09:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727735AbfKFJPm (ORCPT ); Wed, 6 Nov 2019 04:15:42 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:47065 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727363AbfKFJPm (ORCPT ); Wed, 6 Nov 2019 04:15:42 -0500 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iSHPg-0002eW-I5; Wed, 06 Nov 2019 10:15:40 +0100 Received: from sha by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1iSHPe-0000Ao-H0; Wed, 06 Nov 2019 10:15:38 +0100 From: Sascha Hauer To: linux-fsdevel@vger.kernel.org Cc: linux-mtd@lists.infradead.org, Jan Kara , Richard Weinberger , kernel@pengutronix.de, Sascha Hauer Subject: [PATCH 1/7] quota: Allow to pass mount path to quotactl Date: Wed, 6 Nov 2019 10:15:31 +0100 Message-Id: <20191106091537.32480-2-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.24.0.rc1 In-Reply-To: <20191106091537.32480-1-s.hauer@pengutronix.de> References: <20191106091537.32480-1-s.hauer@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-fsdevel@vger.kernel.org Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This patch introduces the Q_PATH flag to the quotactl cmd argument. When given, the path given in the special argument to quotactl will be the mount path where the filesystem is mounted, instead of a path to the block device. This is necessary for filesystems which do not have a block device as backing store. Particularly this is done for upcoming UBIFS support. Signed-off-by: Sascha Hauer --- fs/quota/quota.c | 37 ++++++++++++++++++++++++++++--------- include/uapi/linux/quota.h | 1 + 2 files changed, 29 insertions(+), 9 deletions(-) diff --git a/fs/quota/quota.c b/fs/quota/quota.c index cb13fb76dbee..035cdd1b022b 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -19,6 +19,7 @@ #include #include #include +#include static int check_quotactl_permission(struct super_block *sb, int type, int cmd, qid_t id) @@ -825,12 +826,16 @@ int kernel_quotactl(unsigned int cmd, const char __user *special, { uint cmds, type; struct super_block *sb = NULL; - struct path path, *pathp = NULL; + struct path path, *pathp = NULL, qpath; int ret; + bool q_path; cmds = cmd >> SUBCMDSHIFT; type = cmd & SUBCMDMASK; + q_path = cmds & Q_PATH; + cmds &= ~Q_PATH; + /* * As a special case Q_SYNC can be called without a specific device. * It will iterate all superblocks that have quota enabled and call @@ -855,19 +860,33 @@ int kernel_quotactl(unsigned int cmd, const char __user *special, pathp = &path; } - sb = quotactl_block(special, cmds); - if (IS_ERR(sb)) { - ret = PTR_ERR(sb); - goto out; + if (q_path) { + ret = user_path_at(AT_FDCWD, special, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, + &qpath); + if (ret) + goto out1; + + sb = qpath.mnt->mnt_sb; + } else { + sb = quotactl_block(special, cmds); + if (IS_ERR(sb)) { + ret = PTR_ERR(sb); + goto out; + } } ret = do_quotactl(sb, type, cmds, id, addr, pathp); - if (!quotactl_cmd_onoff(cmds)) - drop_super(sb); - else - drop_super_exclusive(sb); + if (!q_path) { + if (!quotactl_cmd_onoff(cmds)) + drop_super(sb); + else + drop_super_exclusive(sb); + } out: + if (q_path) + path_put(&qpath); +out1: if (pathp && !IS_ERR(pathp)) path_put(pathp); return ret; diff --git a/include/uapi/linux/quota.h b/include/uapi/linux/quota.h index f17c9636a859..e1787c0df601 100644 --- a/include/uapi/linux/quota.h +++ b/include/uapi/linux/quota.h @@ -71,6 +71,7 @@ #define Q_GETQUOTA 0x800007 /* get user quota structure */ #define Q_SETQUOTA 0x800008 /* set user quota structure */ #define Q_GETNEXTQUOTA 0x800009 /* get disk limits and usage >= ID */ +#define Q_PATH 0x400000 /* quotactl special arg contains mount path */ /* Quota format type IDs */ #define QFMT_VFS_OLD 1