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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 3828DC43381 for ; Tue, 26 Jan 2021 16:20:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E09820735 for ; Tue, 26 Jan 2021 16:20:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391043AbhAZQTn (ORCPT ); Tue, 26 Jan 2021 11:19:43 -0500 Received: from mx2.suse.de ([195.135.220.15]:35982 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392835AbhAZQTL (ORCPT ); Tue, 26 Jan 2021 11:19:11 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2EEAFACF5; Tue, 26 Jan 2021 16:18:30 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id A22FF1E0879; Tue, 26 Jan 2021 17:18:29 +0100 (CET) Date: Tue, 26 Jan 2021 17:18:29 +0100 From: Jan Kara To: Christoph Hellwig Cc: Jan Kara , Sascha Hauer , linux-fsdevel@vger.kernel.org, Richard Weinberger , linux-mtd@lists.infradead.org, kernel@pengutronix.de, Jan Kara Subject: Re: [PATCH 1/8] quota: Allow to pass mount path to quotactl Message-ID: <20210126161829.GG10966@quack2.suse.cz> References: <20210122151536.7982-1-s.hauer@pengutronix.de> <20210122151536.7982-2-s.hauer@pengutronix.de> <20210122171658.GA237653@infradead.org> <20210125083854.GB31738@pengutronix.de> <20210125154507.GH1175@quack2.suse.cz> <20210125204249.GA1103662@infradead.org> <20210126131752.GB10966@quack2.suse.cz> <20210126133406.GA1346375@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210126133406.GA1346375@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue 26-01-21 13:34:06, Christoph Hellwig wrote: > On Tue, Jan 26, 2021 at 02:17:52PM +0100, Jan Kara wrote: > > Well, I don't think that "wait until unfrozen" is that strange e.g. for > > Q_SETQUOTA - it behaves like setxattr() or any other filesystem > > modification operation. And IMO it is desirable that filesystem freezing is > > transparent for operations like these. For stuff like Q_QUOTAON, I agree > > that returning EBUSY makes sense but then I'm not convinced it's really > > simpler or more useful behavior... > > If we want it to behave like other syscalls we'll just need to throw in > a mnt_want_write/mnt_drop_write pair. Than it behaves exactly like other > syscalls. Right, we could do that. I'd just note that the "wait until unfrozen" and holding of sb->s_umount semaphore is equivalent to mnt_want_write/mnt_drop_write pair. But I agree mnt_want_write/mnt_drop_write is easier to understand and there's no reason not to use it. So I'm for that simplification in the new syscall. Honza -- Jan Kara SUSE Labs, CR 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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 59826C433DB for ; Tue, 26 Jan 2021 16:19:36 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F264720735 for ; Tue, 26 Jan 2021 16:19:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F264720735 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=wXBU98OJ5rta6Ay4Qslfzxvi1bPV9Ff/YBP1lSS3d0Q=; b=2QEihpPA3SeMeVWPrhi3wuFqB l/EhuixuRjZAXeX49Hz6lMv+m/HNU5451TM2TAOqLBFxDkOyVMOn4By+2ikLJLHY2ARCzJ9GaqtUg ZwyCW4jbO3e53y+oQnduICPz8ZWYEbk+WyODaX7xEowACTgbTlpnlSi9DL9OGsxbO5y98t6E/a8Aj EEuhqwMO6mbeoPOFyVvhCN8tIsFtQ0JVPKhtABghkxJqtafXK+La7V2U3/L0lI9ptxsZ71duddwFn UvPEwwsAfBw5sRCKinBUAUVX2LSRrIJNycPeDclWRDgwiqVJ+1jcQyIOxay5MC0HIVcr8WYz8rVDM YnzbvHnCA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4R35-0000jr-VR; Tue, 26 Jan 2021 16:18:36 +0000 Received: from mx2.suse.de ([195.135.220.15]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l4R32-0000jD-Ne for linux-mtd@lists.infradead.org; Tue, 26 Jan 2021 16:18:33 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2EEAFACF5; Tue, 26 Jan 2021 16:18:30 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id A22FF1E0879; Tue, 26 Jan 2021 17:18:29 +0100 (CET) Date: Tue, 26 Jan 2021 17:18:29 +0100 From: Jan Kara To: Christoph Hellwig Subject: Re: [PATCH 1/8] quota: Allow to pass mount path to quotactl Message-ID: <20210126161829.GG10966@quack2.suse.cz> References: <20210122151536.7982-1-s.hauer@pengutronix.de> <20210122151536.7982-2-s.hauer@pengutronix.de> <20210122171658.GA237653@infradead.org> <20210125083854.GB31738@pengutronix.de> <20210125154507.GH1175@quack2.suse.cz> <20210125204249.GA1103662@infradead.org> <20210126131752.GB10966@quack2.suse.cz> <20210126133406.GA1346375@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210126133406.GA1346375@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210126_111832_892597_5A7B5EA2 X-CRM114-Status: GOOD ( 17.59 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jan Kara , Richard Weinberger , Sascha Hauer , linux-mtd@lists.infradead.org, kernel@pengutronix.de, Jan Kara , linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Tue 26-01-21 13:34:06, Christoph Hellwig wrote: > On Tue, Jan 26, 2021 at 02:17:52PM +0100, Jan Kara wrote: > > Well, I don't think that "wait until unfrozen" is that strange e.g. for > > Q_SETQUOTA - it behaves like setxattr() or any other filesystem > > modification operation. And IMO it is desirable that filesystem freezing is > > transparent for operations like these. For stuff like Q_QUOTAON, I agree > > that returning EBUSY makes sense but then I'm not convinced it's really > > simpler or more useful behavior... > > If we want it to behave like other syscalls we'll just need to throw in > a mnt_want_write/mnt_drop_write pair. Than it behaves exactly like other > syscalls. Right, we could do that. I'd just note that the "wait until unfrozen" and holding of sb->s_umount semaphore is equivalent to mnt_want_write/mnt_drop_write pair. But I agree mnt_want_write/mnt_drop_write is easier to understand and there's no reason not to use it. So I'm for that simplification in the new syscall. Honza -- Jan Kara SUSE Labs, CR ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/