From patchwork Wed May 31 12:55:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 13262228 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D6E6C77B7A for ; Wed, 31 May 2023 12:59:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235575AbjEaM74 (ORCPT ); Wed, 31 May 2023 08:59:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53254 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236287AbjEaM7a (ORCPT ); Wed, 31 May 2023 08:59:30 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8649410F2; Wed, 31 May 2023 05:58:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=BkMJYLyGIWkYjuepxBcnRSaYAK6gaKTk6CK4IG7Jagc=; b=a+V7FBYOqSmWKU7BICZS8m3Pog +h3Wz3MRqEpA0GkjgoCFFAOXNSXfvpmy5id6oojyv9QqLV7MkTKk0Y5pwXC7oH2wJ9DETfyR0ADG3 DzmcF5ncYO4eRGu5mLsP257uUY9Q0chtNa0qjQLb4WWpKmviXwqrs9D2Nufl2sc+eHtS2jeWmimII Ytpa1OApjHx7Mn71mygtkjZeJ4on69jBo/44nLan9GaBimk8uVuIZSrv+8dK6+S7aq+W6CFqHrif2 8n1RAXi+ug1lZN2STbBwExeulaEYzJiDQAZr33zrGslFVOc6nBvN+uMr6dcNqOdad/4g/pxDgXYAv yPZMz2JQ==; Received: from [2001:4bb8:182:6d06:2e49:a56:513a:92ee] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1q4LOQ-00HSDd-2L; Wed, 31 May 2023 12:57:35 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Mike Snitzer , Joern Engel , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Pavel Machek , Loic Poulain , dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-mtd@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH 23/24] mtd: block2mtd: don't call early_lookup_bdev after the system is running Date: Wed, 31 May 2023 14:55:34 +0200 Message-Id: <20230531125535.676098-24-hch@lst.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230531125535.676098-1-hch@lst.de> References: <20230531125535.676098-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org early_lookup_bdev is supposed to only be called from the early boot code, but mdtblock_early_get_bdev is called as a general fallback when lookup_bdev fails, which is problematic because early_lookup_bdev bypasses all normal path based permission checking, and might cause problems with certain container environments renaming devices. Switch to only call early_lookup_bdev when block2mtd is built-in and the system state in not running yet. Note that this strictly speaking changes the kernel ABI as the PARTUUID= and PARTLABEL= style syntax is now not available during a running systems. They never were intended for that, but this breaks things we'll have to figure out a way to make them available again. But if avoidable in any way I'd rather avoid that. Signed-off-by: Christoph Hellwig Reviewed-by: Miquel Raynal --- drivers/mtd/devices/block2mtd.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c index 182eed68c75634..59e4c71cfc6f53 100644 --- a/drivers/mtd/devices/block2mtd.c +++ b/drivers/mtd/devices/block2mtd.c @@ -215,13 +215,23 @@ static void block2mtd_free_device(struct block2mtd_dev *dev) kfree(dev); } -static struct block_device *mdtblock_early_get_bdev(const char *devname, +/* + * This function is marked __ref because it calls the __init marked + * early_lookup_bdev when called from the early boot code. + */ +static struct block_device __ref *mdtblock_early_get_bdev(const char *devname, fmode_t mode, int timeout, struct block2mtd_dev *dev) { struct block_device *bdev = ERR_PTR(-ENODEV); #ifndef MODULE int i; + /* + * We can't use early_lookup_bdev from a running system. + */ + if (system_state >= SYSTEM_RUNNING) + return bdev; + /* * We might not have the root device mounted at this point. * Try to resolve the device name by other means.