From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF954C2D0DB for ; Fri, 24 Jan 2020 13:13:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99A7C2087E for ; Fri, 24 Jan 2020 13:13:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389219AbgAXNNg (ORCPT ); Fri, 24 Jan 2020 08:13:36 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:36551 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389187AbgAXNNg (ORCPT ); Fri, 24 Jan 2020 08:13:36 -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 1iuym5-0003aE-RR; Fri, 24 Jan 2020 14:13:25 +0100 Received: from sha by dude.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1iuym5-0006Z8-0V; Fri, 24 Jan 2020 14:13:25 +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 1/8] quota: Allow to pass mount path to quotactl Date: Fri, 24 Jan 2020 14:13:16 +0100 Message-Id: <20200124131323.23885-2-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124131323.23885-1-s.hauer@pengutronix.de> References: <20200124131323.23885-1-s.hauer@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 | 53 +++++++++++++++++++++++++++----------- include/uapi/linux/quota.h | 1 + 2 files changed, 39 insertions(+), 15 deletions(-) diff --git a/fs/quota/quota.c b/fs/quota/quota.c index 5444d3c4d93f..9ef51d02d5a5 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) @@ -821,15 +822,20 @@ 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 file_path, *file_pathp = NULL, sb_path; int ret; + bool q_path; cmds = cmd >> SUBCMDSHIFT; type = cmd & SUBCMDMASK; + if (type >= MAXQUOTAS) return -EINVAL; + 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 @@ -847,28 +853,45 @@ int kernel_quotactl(unsigned int cmd, const char __user *special, * resolution (think about autofs) and thus deadlocks could arise. */ if (cmds == Q_QUOTAON) { - ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path); + ret = user_path_at(AT_FDCWD, addr, + LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, + &file_path); if (ret) - pathp = ERR_PTR(ret); + file_pathp = ERR_PTR(ret); else - pathp = &path; + file_pathp = &file_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, + &sb_path); + if (ret) + goto out; + + sb = sb_path.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); + ret = do_quotactl(sb, type, cmds, id, addr, file_pathp); + + if (q_path) { + path_put(&sb_path); + } else { + if (!quotactl_cmd_onoff(cmds)) + drop_super(sb); + else + drop_super_exclusive(sb); + } - if (!quotactl_cmd_onoff(cmds)) - drop_super(sb); - else - drop_super_exclusive(sb); out: - if (pathp && !IS_ERR(pathp)) - path_put(pathp); + if (file_pathp && !IS_ERR(file_pathp)) + path_put(file_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 -- 2.25.0