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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 7CE0EC32753 for ; Wed, 14 Aug 2019 23:40:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 4BA9B206C1 for ; Wed, 14 Aug 2019 23:40:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LaR/vLaJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BA9B206C1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk 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=bombadil.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=nftolgEwdhaoJ9e0BASViDOmVb8S00rw3LfDovtFcx4=; b=LaR/vLaJi7npVD jkWSY7qxb3NRMawOoko8d68d/1TrQZe+TMiOlYpq9QabMCzntBTFnWzc21u1aTAiz/DQ2dNQ8EDkl TWd5ITk4qya395ekVbmWObVHRpnTn6W5/Uw8GwQPS4YoEhxHF8EGlNU54syI8fRA9vJVcfr3uOGAC QryxGqUdRmLKRoiG2YWOM5ZLjbEHDiCeOPlXmspi+iIQlnKJQyvBv50AH3HFtG3iLy6f4jJ+iEyb+ 4R9FGLV5zKi83uc7aw+Y7YVegBUdkdyv4BNOSds0v9tT7bdtgomba0BGOgRHwrNLnooXAxkn+Xitz sovWfRuX9RcC5ogOeqQw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hy2rw-0002s2-8Q; Wed, 14 Aug 2019 23:39:52 +0000 Received: from zeniv.linux.org.uk ([195.92.253.2]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hy2rs-0002m0-Qd for linux-mtd@lists.infradead.org; Wed, 14 Aug 2019 23:39:49 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hy2rq-0001jN-5Z; Wed, 14 Aug 2019 23:39:46 +0000 Date: Thu, 15 Aug 2019 00:39:46 +0100 From: Al Viro To: Sascha Hauer Subject: Re: [PATCH 05/11] quota: Allow to pass quotactl a mountpoint Message-ID: <20190814233946.GX1131@ZenIV.linux.org.uk> References: <20190814121834.13983-1-s.hauer@pengutronix.de> <20190814121834.13983-6-s.hauer@pengutronix.de> <20190814233632.GW1131@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190814233632.GW1131@ZenIV.linux.org.uk> User-Agent: Mutt/1.12.0 (2019-05-25) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190814_163948_865061_7B9172C8 X-CRM114-Status: GOOD ( 11.97 ) 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: linux-fsdevel@vger.kernel.org, Richard Weinberger , linux-mtd@lists.infradead.org, kernel@pengutronix.de, Jan Kara 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 Thu, Aug 15, 2019 at 12:36:32AM +0100, Al Viro wrote: > On Wed, Aug 14, 2019 at 02:18:28PM +0200, Sascha Hauer wrote: > > +/** > > + * reference_super - get a reference to a given superblock > > + * @sb: superblock to get the reference from > > + * > > + * Takes a reference to a superblock. Can be used as when the superblock > > + * is known and leaves it in a state as if get_super had been called. > > + */ > > +void reference_super(struct super_block *sb) > > +{ > > + spin_lock(&sb_lock); > > + sb->s_count++; > > + spin_unlock(&sb_lock); > > + > > + down_read(&sb->s_umount); > > +} > > +EXPORT_SYMBOL_GPL(reference_super); > > NAK, for a plenty of reasons > > 1) introduction of EXPORT_SYMBOL_GPL garbage > 2) aforementioned garbage on something that doesn't need to be exported > 3) *way* too easily abused - get_super() is, at least, not tempting to > play with in random code. This one is, and it's too low-level to > allow. ... and this is a crap userland API. *IF* you want mountpoint-based variants of quotactl() commands, by all means, add those. Do not overload the old ones. And for path-based you don't need to mess with superblock references - just keep the struct path until the end. That will keep the superblock alive and active just fine. ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/