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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 52B61C433DB for ; Thu, 11 Feb 2021 16:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11EBC64D9E for ; Thu, 11 Feb 2021 16:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231735AbhBKQgh (ORCPT ); Thu, 11 Feb 2021 11:36:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231348AbhBKPbQ (ORCPT ); Thu, 11 Feb 2021 10:31:16 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 494EFC061574 for ; Thu, 11 Feb 2021 07:30:36 -0800 (PST) Received: from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lADvG-0006zD-Op; Thu, 11 Feb 2021 16:30:26 +0100 Received: from sha by dude02.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lADvF-0000AD-N5; Thu, 11 Feb 2021 16:30:25 +0100 From: Sascha Hauer To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Christoph Hellwig , kernel@pengutronix.de, Jan Kara , Richard Weinberger , Sascha Hauer Subject: [PATCH 1/2] quota: Add mountpath based quota support Date: Thu, 11 Feb 2021 16:30:22 +0100 Message-Id: <20210211153024.32502-2-s.hauer@pengutronix.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210211153024.32502-1-s.hauer@pengutronix.de> References: <20210211153024.32502-1-s.hauer@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::28 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-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add syscall quotactl_path, a variant of quotactl which allows to specify the mountpath instead of a path of to a block device. The quotactl syscall expects a path to the mounted block device to specify the filesystem to work on. This limits usage to filesystems which actually have a block device. quotactl_path replaces the path to the block device with a path where the filesystem is mounted at. The global Q_SYNC command to sync all filesystems is not supported for this new syscall, otherwise quotactl_path behaves like quotactl. Signed-off-by: Sascha Hauer --- fs/quota/quota.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/fs/quota/quota.c b/fs/quota/quota.c index 6d16b2be5ac4..6f1df32abeea 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include "compat.h" @@ -968,3 +969,51 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special, path_put(pathp); return ret; } + +SYSCALL_DEFINE4(quotactl_path, unsigned int, cmd, const char __user *, + mountpoint, qid_t, id, void __user *, addr) +{ + struct super_block *sb; + struct path mountpath; + unsigned int cmds = cmd >> SUBCMDSHIFT; + unsigned int type = cmd & SUBCMDMASK; + int ret; + + if (type >= MAXQUOTAS) + return -EINVAL; + + if (!mountpoint) + return -ENODEV; + + ret = user_path_at(AT_FDCWD, mountpoint, + LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT, &mountpath); + if (ret) + return ret; + + sb = mountpath.dentry->d_inode->i_sb; + + if (quotactl_cmd_write(cmds)) { + ret = mnt_want_write(mountpath.mnt); + if (ret) + goto out; + } + + if (quotactl_cmd_onoff(cmds)) + down_write(&sb->s_umount); + else + down_read(&sb->s_umount); + + ret = do_quotactl(sb, type, cmds, id, addr, ERR_PTR(-EINVAL)); + + if (quotactl_cmd_onoff(cmds)) + up_write(&sb->s_umount); + else + up_read(&sb->s_umount); + + if (quotactl_cmd_write(cmds)) + mnt_drop_write(mountpath.mnt); +out: + path_put(&mountpath); + + return ret; +} -- 2.20.1