From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:57966 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750831AbdAXJBz (ORCPT ); Tue, 24 Jan 2017 04:01:55 -0500 Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v0O8wcIj068595 for ; Tue, 24 Jan 2017 04:01:54 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0b-001b2d01.pphosted.com with ESMTP id 28612we5bw-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 24 Jan 2017 04:01:54 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 24 Jan 2017 09:01:53 -0000 From: Christian Borntraeger To: Chris Mason Cc: Linux Kernel Mailing List , linux-btrfs , Christian Borntraeger Subject: [PATCH 2/2] btrfs: add lockdep annotation for btrfs_log_inode Date: Tue, 24 Jan 2017 10:01:47 +0100 In-Reply-To: <1485248507-6079-1-git-send-email-borntraeger@de.ibm.com> References: <20161126134638.GA79987@clm-mbp.masoncoding.com> <1485248507-6079-1-git-send-email-borntraeger@de.ibm.com> Message-Id: <1485248507-6079-2-git-send-email-borntraeger@de.ibm.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: Add a proper subclass to get rid of the following lockdep error. [ INFO: possible recursive locking detected ] 4.9.0+ #279 Not tainted --------------------------------------------- vim/4801 is trying to acquire lock: (&ei->log_mutex){+.+...}, at: [<000003ff82057592>] btrfs_log_inode+0x182/0xfa8 [btrfs] (&ei->log_mutex){+.+...}, at: [<000003ff82057592>] btrfs_log_inode+0x182/0xfa8 [btrfs] Possible unsafe locking scenario: CPU0 ---- lock(&ei->log_mutex); lock(&ei->log_mutex); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by vim/4801: #0: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<000003ff81fc274c>] btrfs_sync_file+0x204/0x728 [btrfs] #1: (sb_internal#2){.+.+..}, at: [<000003ff81fa38e0>] start_transaction+0x318/0x770 [btrfs] #2: (&ei->log_mutex){+.+...}, at: [<000003ff82057592>] [...] Call Trace: ([<0000000000115ffc>] show_trace+0xe4/0x108) [<00000000001160f8>] show_stack+0x68/0xe0 [<0000000000652d52>] dump_stack+0x9a/0xd8 [<0000000000209bb0>] __lock_acquire+0xac8/0x1bd0 [<000000000020b3c6>] lock_acquire+0x106/0x4a0 [<0000000000a1fb36>] mutex_lock_nested+0xa6/0x428 [<000003ff82057592>] btrfs_log_inode+0x182/0xfa8 [btrfs] [<000003ff82057c76>] btrfs_log_inode+0x866/0xfa8 [btrfs] [<000003ff81ffe278>] btrfs_log_inode_parent+0x218/0x988 [btrfs] [<000003ff81ffffaa>] btrfs_log_dentry_safe+0x7a/0xa0 [btrfs] [<000003ff81fc29b6>] btrfs_sync_file+0x46e/0x728 [btrfs] [<000000000044aeee>] do_fsync+0x5e/0x90 [<000000000044b2ba>] SyS_fsync+0x32/0x40 [<0000000000a26786>] system_call+0xd6/0x288 Signed-off-by: Christian Borntraeger --- fs/btrfs/tree-log.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 3d33c4e..a3ec717 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4648,7 +4648,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, return ret; } - mutex_lock(&BTRFS_I(inode)->log_mutex); + mutex_lock_nested(&BTRFS_I(inode)->log_mutex, inode_only); /* * a brute force approach to making sure we get the most uptodate -- 2.7.4