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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 AFE84C47253 for ; Fri, 1 May 2020 13:53:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F2D22051A for ; Fri, 1 May 2020 13:53:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588341190; bh=DEKOV80S+EgZGm5x0oH/1MuU21eybiRSXazP2DjWCGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0H8Ch6htmJ0UwapC9sWO6j9lw7pDCoC71E/YgTGQOF0Ukf3f/j+Cbq5/laHlaAIrU n3aNXk3llClkE0cZ2gxeOt5VxOSLcqJaNaIU8RG6sVws31jtU2HQ9OLOo4cxIxRw5v jW7uwrIdi2Grkup49FKZRadVAaeR/Z5BO/EE4FWg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730464AbgEANgq (ORCPT ); Fri, 1 May 2020 09:36:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:35206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730877AbgEANgi (ORCPT ); Fri, 1 May 2020 09:36:38 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7734E208DB; Fri, 1 May 2020 13:36:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588340197; bh=DEKOV80S+EgZGm5x0oH/1MuU21eybiRSXazP2DjWCGA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vw+kNrV62uLWJ/fZfXCe4CCxeqd6aAUxm0oRtIJCUupGyMlm7vbfA1XHXAI1N+X9S YcRm7XIHEEzE6sGY5Pqr2TwYweFpZYWypZ8TgeVSEzZrm8BI9gYV5AvBPkWriuCB1N b/NQcpqwlrUAsSzXyI7VsiiEGIuvekoUbXLfbaaU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Furtado , Brian Foster , Chandan Rajendra , Christoph Hellwig , Allison Collins , "Darrick J. Wong" Subject: [PATCH 4.19 15/46] xfs: acquire superblock freeze protection on eofblocks scans Date: Fri, 1 May 2020 15:22:40 +0200 Message-Id: <20200501131503.899313616@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200501131457.023036302@linuxfoundation.org> References: <20200501131457.023036302@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Brian Foster commit 4b674b9ac852937af1f8c62f730c325fb6eadcdb upstream. The filesystem freeze sequence in XFS waits on any background eofblocks or cowblocks scans to complete before the filesystem is quiesced. At this point, the freezer has already stopped the transaction subsystem, however, which means a truncate or cowblock cancellation in progress is likely blocked in transaction allocation. This results in a deadlock between freeze and the associated scanner. Fix this problem by holding superblock write protection across calls into the block reapers. Since protection for background scans is acquired from the workqueue task context, trylock to avoid a similar deadlock between freeze and blocking on the write lock. Fixes: d6b636ebb1c9f ("xfs: halt auto-reclamation activities while rebuilding rmap") Reported-by: Paul Furtado Signed-off-by: Brian Foster Reviewed-by: Chandan Rajendra Reviewed-by: Christoph Hellwig Reviewed-by: Allison Collins Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_icache.c | 10 ++++++++++ fs/xfs/xfs_ioctl.c | 5 ++++- 2 files changed, 14 insertions(+), 1 deletion(-) --- a/fs/xfs/xfs_icache.c +++ b/fs/xfs/xfs_icache.c @@ -902,7 +902,12 @@ xfs_eofblocks_worker( { struct xfs_mount *mp = container_of(to_delayed_work(work), struct xfs_mount, m_eofblocks_work); + + if (!sb_start_write_trylock(mp->m_super)) + return; xfs_icache_free_eofblocks(mp, NULL); + sb_end_write(mp->m_super); + xfs_queue_eofblocks(mp); } @@ -929,7 +934,12 @@ xfs_cowblocks_worker( { struct xfs_mount *mp = container_of(to_delayed_work(work), struct xfs_mount, m_cowblocks_work); + + if (!sb_start_write_trylock(mp->m_super)) + return; xfs_icache_free_cowblocks(mp, NULL); + sb_end_write(mp->m_super); + xfs_queue_cowblocks(mp); } --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -2182,7 +2182,10 @@ xfs_file_ioctl( if (error) return error; - return xfs_icache_free_eofblocks(mp, &keofb); + sb_start_write(mp->m_super); + error = xfs_icache_free_eofblocks(mp, &keofb); + sb_end_write(mp->m_super); + return error; } default: