From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725913AbgHWJLA (ORCPT ); Sun, 23 Aug 2020 05:11:00 -0400 From: Christoph Hellwig Subject: fix block device size update serialization v2 Date: Sun, 23 Aug 2020 11:10:40 +0200 Message-Id: <20200823091043.2600261-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Jens Axboe Cc: Justin Sanders , Josef Bacik , Xianting Tian , linux-block@vger.kernel.org, dm-devel@redhat.com, Stefan Haberland , Jan Hoeppner , linux-kernel@vger.kernel.org, nbd@other.debian.org, linux-nvme@lists.infradead.org, linux-s390@vger.kernel.org Hi Jens, this series fixes how we update i_size for the block device inodes (and thus the block device). Different helpers use two different locks (bd_mutex and i_rwsem) to protect the update, and it appears device mapper uses yet another internal lock. A lot of the drivers do the update handcrafted in often crufty ways. And in addition to that mess it turns out that the "main" lock, bd_mutex is pretty dead lock prone vs other spots in the block layer that acquire it during revalidation operations, as reported by Xianting. Fix all that by adding a dedicated spinlock just for the size updates. Changes since v1: - don't call __invalidate_device under the new spinlock - don't call into the file system code from the nvme removal code