From patchwork Tue Sep 11 17:57:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Josef Bacik X-Patchwork-Id: 10596087 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A44CC14BD for ; Tue, 11 Sep 2018 17:58:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 908A629B9D for ; Tue, 11 Sep 2018 17:58:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 851BF29BA0; Tue, 11 Sep 2018 17:58:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2306C29B9D for ; Tue, 11 Sep 2018 17:58:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728309AbeIKW7K (ORCPT ); Tue, 11 Sep 2018 18:59:10 -0400 Received: from mail-qk1-f194.google.com ([209.85.222.194]:36864 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728184AbeIKW7K (ORCPT ); Tue, 11 Sep 2018 18:59:10 -0400 Received: by mail-qk1-f194.google.com with SMTP id f17-v6so17317280qkh.4 for ; Tue, 11 Sep 2018 10:58:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=toxicpanda-com.20150623.gappssmtp.com; s=20150623; h=from:to:subject:date:message-id:in-reply-to:references; bh=BgDRhtJ88t7ugG2XXq1rTUKV8IL4k8Uo9zOi0L9ZWBs=; b=c7DefdZl4bCNJNOAVjAhWQG3BReN3w6cVvjC2l4l4wfvZGb0r9IUlTP762j5xN+yw9 9uKsFKeYP68oLZQDBvTDkJI2NSYT1FkO+D6ciJZoPCQ1DZ1ilKQegVNoaO0TrvqSfkE7 WcJTeZ699LBILm+CioCB38fKk47YPVr5KgC8YpektepUYFL98dcJ67rVYycO0nkuTQHe lzv2Smxg1eI7+B1UtC3l/GDOI7qX3jiVyj5SJBJRq9zdJfDk056pa08LNISeh1jYPlVs QbMOtlfspCGZI+VvMAqvd8syJ6lx1YeyYynHqkH9O6TMhhvEKcmTW27UTF0HTR12FNi2 eEeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references; bh=BgDRhtJ88t7ugG2XXq1rTUKV8IL4k8Uo9zOi0L9ZWBs=; b=g/PrNWv/Lt5KJtmAuF69d+fAqAZEPdaWz5hMW3qF1oxPIMl2Cmff0qJOlH0Pfzt2TX bDGKVCUNQdmnT7tc9lkj7H0cWm9XYN2jPFr8QHX5hmYN6KJclin8ChpvM5Tc5lMCxzVI qVqDJ3OV86mpGy+JVGdQXT+7UOj4tqKvgqZrdgexiU2E+7vjMh4NtS2UluYxSUdjUgDI zLYeX0jZWbHMzzROUA3cJCqA7K6/Rvo9m2pLIth0RC2RkWlg4ih38yJFmyyBe8tfpgX8 Ob177Alqc7GWIcLwh3mjUrRfzPveDba0fjV6d/0SG5xWfZsov4HbO/RcZBfPlsN1PrMk C7NA== X-Gm-Message-State: APzg51BoCfmjmmOBb/DCJKn9SulinRD0iQ0QRaFEhrQEmJEJseohTX1g VSWPitSlUzj3IjGXUiXE3UZctQ== X-Google-Smtp-Source: ANB0Vdb/ISdhru1MWaTw5WiV0ThHZUAXnx35ZOIlSh0vo2RP/jPcqPoy6b0uN0RCYb/nY2px0o7zhQ== X-Received: by 2002:a37:6142:: with SMTP id v63-v6mr19834902qkb.80.1536688723796; Tue, 11 Sep 2018 10:58:43 -0700 (PDT) Received: from localhost ([107.15.81.208]) by smtp.gmail.com with ESMTPSA id f25-v6sm12982918qkh.13.2018.09.11.10.58.42 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 11 Sep 2018 10:58:42 -0700 (PDT) From: Josef Bacik To: kernel-team@fb.com, linux-btrfs@vger.kernel.org Subject: [PATCH 18/36] btrfs: move the dio_sem higher up the callchain Date: Tue, 11 Sep 2018 13:57:49 -0400 Message-Id: <20180911175807.26181-19-josef@toxicpanda.com> X-Mailer: git-send-email 2.14.3 In-Reply-To: <20180911175807.26181-1-josef@toxicpanda.com> References: <20180911175807.26181-1-josef@toxicpanda.com> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We're getting a lockdep splat because we take the dio_sem under the log_mutex. What we really need is to protect fsync() from logging an extent map for an extent we never waited on higher up, so just guard the whole thing with dio_sem. Signed-off-by: Josef Bacik --- fs/btrfs/file.c | 12 ++++++++++++ fs/btrfs/tree-log.c | 2 -- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 095f0bb86bb7..c07110edb9de 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2079,6 +2079,14 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) goto out; inode_lock(inode); + + /* + * We take the dio_sem here because the tree log stuff can race with + * lockless dio writes and get an extent map logged for an extent we + * never waited on. We need it this high up for lockdep reasons. + */ + down_write(&BTRFS_I(inode)->dio_sem); + atomic_inc(&root->log_batch); /* @@ -2087,6 +2095,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) */ ret = btrfs_wait_ordered_range(inode, start, len); if (ret) { + up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } @@ -2110,6 +2119,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) * checked called fsync. */ ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err); + up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } @@ -2128,6 +2138,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); + up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } @@ -2149,6 +2160,7 @@ int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) * file again, but that will end up using the synchronization * inside btrfs_sync_log to keep things safe. */ + up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); /* diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 1650dc44a5e3..66b7e059b765 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4374,7 +4374,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, INIT_LIST_HEAD(&extents); - down_write(&inode->dio_sem); write_lock(&tree->lock); test_gen = root->fs_info->last_trans_committed; logged_start = start; @@ -4440,7 +4439,6 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans, } WARN_ON(!list_empty(&extents)); write_unlock(&tree->lock); - up_write(&inode->dio_sem); btrfs_release_path(path); if (!ret)