Received: by 2002:ad5:474a:0:0:0:0:0 with SMTP id i10csp3466842imu; Sun, 11 Nov 2018 15:45:53 -0800 (PST) X-Google-Smtp-Source: AJdET5ed52wXO3cwqU6h5wMQ/CfuslxKLTMZTSMwKgsuqzDVa6eTKnO/FYpaAOZtOHaueoaWA+je X-Received: by 2002:a17:902:8504:: with SMTP id bj4-v6mr17287118plb.99.1541979953854; Sun, 11 Nov 2018 15:45:53 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1541979953; cv=none; d=google.com; s=arc-20160816; b=iVvErEsck9QHv9XGFJAC8pV6SoDn/4auoGZ0ThqDh4fF0RRxGLpevuOOEqkpdmAi9t /OlisPglyePbfrVtAQAttIbKDK7R5zNdbnynvNAh02WqndbT/iCvTGcC+/Ii6BQLb4aG 4vvHAvZGHTXeiMV24cAhFmMF64nKI/x+IKrBMlhE/XVFicJB4/s+/8ZgiT7Hi2kbPP7A thA6hmslNWL3FPjWnzjxpFeCKc0iIcQB34IN1KkbnDZUQ2UIMT7K+Noq/yYeaBvmfBxV S3hIVlFabiDy+SEub+d0+WYuHEj5ScgfogNXf8IgjtPHtdcoMnWb2L3HHm8l6gXJ6t2J Rh2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=TeJVIL9YXAZfWwfzZ9lQ2Wb/U6uzA0CjTwVxszPCr7M=; b=RUmtEOoBD0eQ7OVtlhCM3V8S1TyvoqIdu+7kgHZy3uys98Mv2goJRE5k1D/s92TMg9 9DtLDD5AjAWl/PcSZTIbwc08D/PkM5YQrTaz7uvLu6KQomAVFBGZSH0v09lIGn52SEzI FHKx6Df8QdctmpYNDNmviET+1NTdWDne49jnsY/JZJrlAJeJe1sWepy2pPmtiC18PFc7 bv9a0IxRQFGHd3KM7TtvABQzHZUigFOban7pAE0R5q/kbQe9P+zwUgKmuhO6bNRTHtbK GyOzC65k0/hMqadKId1Wzrg8x/uk0dmFBfPeNVzkRFgIUVYtkZ+Mld3nOMohasFzYsjG KeiA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=fr5HCFi0; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id w13-v6si13552207pgj.229.2018.11.11.15.45.39; Sun, 11 Nov 2018 15:45:53 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=fr5HCFi0; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387462AbeKLITH (ORCPT + 99 others); Mon, 12 Nov 2018 03:19:07 -0500 Received: from mail.kernel.org ([198.145.29.99]:39838 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733303AbeKLITH (ORCPT ); Mon, 12 Nov 2018 03:19:07 -0500 Received: from localhost (unknown [206.108.79.134]) (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 7774321527; Sun, 11 Nov 2018 22:29:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541975350; bh=qOb4exMRqZxMTjavLOg0Wuq4mYGHud1Ov3vdJWEsMS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fr5HCFi0dS70gns127Fwm3UPtVtgsGukWZUSDJLBUAw1Fjg3hfSMJNwhJrt5KQVwv wZ2J/BoLS9tzn4zkLIsbD2BY1EUCaqte/t6XSNdxC9S89zAFIIjk51tGtuOd9z5Jv9 qtq9KoLwP872ymH9hAhpZ6ZNQ/bnf4k/UTC7Bwus= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Filipe Manana , Josef Bacik , David Sterba Subject: [PATCH 4.19 354/361] btrfs: move the dio_sem higher up the callchain Date: Sun, 11 Nov 2018 14:21:41 -0800 Message-Id: <20181111221701.786512084@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josef Bacik commit c495144bc6962186feae31d687596d2472000e45 upstream. 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. ====================================================== WARNING: possible circular locking dependency detected 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Not tainted ------------------------------------------------------ aio-dio-invalid/30928 is trying to acquire lock: 0000000092621cfd (&mm->mmap_sem){++++}, at: get_user_pages_unlocked+0x5a/0x1e0 but task is already holding lock: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&ei->dio_sem){++++}: lock_acquire+0xbd/0x220 down_write+0x51/0xb0 btrfs_log_changed_extents+0x80/0xa40 btrfs_log_inode+0xbaf/0x1000 btrfs_log_inode_parent+0x26f/0xa80 btrfs_log_dentry_safe+0x50/0x70 btrfs_sync_file+0x357/0x540 do_fsync+0x38/0x60 __ia32_sys_fdatasync+0x12/0x20 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #4 (&ei->log_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_record_unlink_dir+0x2a/0xa0 btrfs_unlink+0x5a/0xc0 vfs_unlink+0xb1/0x1a0 do_unlinkat+0x264/0x2b0 do_fast_syscall_32+0x9a/0x2f0 entry_SYSENTER_compat+0x84/0x96 -> #3 (sb_internal#2){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 start_transaction+0x3e6/0x590 btrfs_evict_inode+0x475/0x640 evict+0xbf/0x1b0 btrfs_run_delayed_iputs+0x6c/0x90 cleaner_kthread+0x124/0x1a0 kthread+0x106/0x140 ret_from_fork+0x3a/0x50 -> #2 (&fs_info->cleaner_delayed_iput_mutex){+.+.}: lock_acquire+0xbd/0x220 __mutex_lock+0x86/0xa10 btrfs_alloc_data_chunk_ondemand+0x197/0x530 btrfs_check_data_free_space+0x4c/0x90 btrfs_delalloc_reserve_space+0x20/0x60 btrfs_page_mkwrite+0x87/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #1 (sb_pagefaults){.+.+}: lock_acquire+0xbd/0x220 __sb_start_write+0x14d/0x230 btrfs_page_mkwrite+0x6a/0x520 do_page_mkwrite+0x31/0xa0 __handle_mm_fault+0x799/0xb00 handle_mm_fault+0x7c/0xe0 __do_page_fault+0x1d3/0x4a0 async_page_fault+0x1e/0x30 -> #0 (&mm->mmap_sem){++++}: __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 down_read+0x48/0xb0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 __blockdev_direct_IO+0x32d/0x1c20 btrfs_direct_IO+0x227/0x400 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 io_submit_one+0x3a9/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 other info that might help us debug this: Chain exists of: &mm->mmap_sem --> &ei->log_mutex --> &ei->dio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->dio_sem); lock(&ei->log_mutex); lock(&ei->dio_sem); lock(&mm->mmap_sem); *** DEADLOCK *** 1 lock held by aio-dio-invalid/30928: #0: 00000000cefe6b35 (&ei->dio_sem){++++}, at: btrfs_direct_IO+0x3be/0x400 stack backtrace: CPU: 0 PID: 30928 Comm: aio-dio-invalid Not tainted 4.18.0-rc4-xfstests-00025-g5de5edbaf1d4 #411 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 Call Trace: dump_stack+0x7c/0xbb print_circular_bug.isra.37+0x297/0x2a4 check_prev_add.constprop.45+0x781/0x7a0 ? __lock_acquire+0x42e/0x7a0 validate_chain.isra.41+0x7f0/0xb00 __lock_acquire+0x42e/0x7a0 lock_acquire+0xbd/0x220 ? get_user_pages_unlocked+0x5a/0x1e0 down_read+0x48/0xb0 ? get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_unlocked+0x5a/0x1e0 get_user_pages_fast+0xa4/0x150 iov_iter_get_pages+0xc3/0x340 do_direct_IO+0xf93/0x1d70 ? __alloc_workqueue_key+0x358/0x490 ? __blockdev_direct_IO+0x14b/0x1c20 __blockdev_direct_IO+0x32d/0x1c20 ? btrfs_run_delalloc_work+0x40/0x40 ? can_nocow_extent+0x490/0x490 ? kvm_clock_read+0x1f/0x30 ? can_nocow_extent+0x490/0x490 ? btrfs_run_delalloc_work+0x40/0x40 btrfs_direct_IO+0x227/0x400 ? btrfs_run_delalloc_work+0x40/0x40 generic_file_direct_write+0xcf/0x180 btrfs_file_write_iter+0x308/0x58c aio_write+0xf8/0x1d0 ? kvm_clock_read+0x1f/0x30 ? __might_fault+0x3e/0x90 io_submit_one+0x3a9/0x620 ? io_submit_one+0xe5/0x620 __ia32_compat_sys_io_submit+0xb2/0x270 do_int80_syscall_32+0x5b/0x1a0 entry_INT80_compat+0x88/0xa0 CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Filipe Manana Signed-off-by: Josef Bacik Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/file.c | 12 ++++++++++++ fs/btrfs/tree-log.c | 2 -- 2 files changed, 12 insertions(+), 2 deletions(-) --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2078,6 +2078,14 @@ int btrfs_sync_file(struct file *file, l 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); /* @@ -2086,6 +2094,7 @@ int btrfs_sync_file(struct file *file, l */ ret = btrfs_wait_ordered_range(inode, start, len); if (ret) { + up_write(&BTRFS_I(inode)->dio_sem); inode_unlock(inode); goto out; } @@ -2109,6 +2118,7 @@ int btrfs_sync_file(struct file *file, l * 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; } @@ -2127,6 +2137,7 @@ int btrfs_sync_file(struct file *file, l 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; } @@ -2148,6 +2159,7 @@ int btrfs_sync_file(struct file *file, l * 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); /* --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4393,7 +4393,6 @@ static int btrfs_log_changed_extents(str INIT_LIST_HEAD(&extents); - down_write(&inode->dio_sem); write_lock(&tree->lock); test_gen = root->fs_info->last_trans_committed; logged_start = start; @@ -4459,7 +4458,6 @@ process: } WARN_ON(!list_empty(&extents)); write_unlock(&tree->lock); - up_write(&inode->dio_sem); btrfs_release_path(path); if (!ret)