From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751963AbdGOBiX (ORCPT ); Fri, 14 Jul 2017 21:38:23 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:53795 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbdGOB1T (ORCPT ); Fri, 14 Jul 2017 21:27:19 -0400 X-IronPort-Anti-Spam-Filtered: false From: "Levin, Alexander (Sasha Levin)" Cc: Liu Bo , David Sterba , "Levin, Alexander (Sasha Levin)" To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH for v4.9 LTS 35/87] Btrfs: fix lockdep warning about log_mutex Thread-Topic: [PATCH for v4.9 LTS 35/87] Btrfs: fix lockdep warning about log_mutex Thread-Index: AQHS/QlWqkBv/SQEOEKTkfCXQmYV1w== Date: Sat, 15 Jul 2017 01:26:08 +0000 Message-ID: <20170715012538.10101-35-alexander.levin@verizon.com> References: <20170715012538.10101-1-alexander.levin@verizon.com> In-Reply-To: <20170715012538.10101-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v6F1chvZ023224 From: Liu Bo [ Upstream commit 781feef7e6befafd4d9787d1f7ada1f9ccd504e4 ] While checking INODE_REF/INODE_EXTREF for a corner case, we may acquire a different inode's log_mutex with holding the current inode's log_mutex, and lockdep has complained this with a possilble deadlock warning. Fix this by using mutex_lock_nested() when processing the other inode's log_mutex. Reviewed-by: Filipe Manana Signed-off-by: Liu Bo Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/tree-log.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index b89004513c09..309313b71617 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -37,6 +37,7 @@ */ #define LOG_INODE_ALL 0 #define LOG_INODE_EXISTS 1 +#define LOG_OTHER_INODE 2 /* * directory trouble cases @@ -4623,7 +4624,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, if (S_ISDIR(inode->i_mode) || (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags) && - inode_only == LOG_INODE_EXISTS)) + inode_only >= LOG_INODE_EXISTS)) max_key.type = BTRFS_XATTR_ITEM_KEY; else max_key.type = (u8)-1; @@ -4647,7 +4648,13 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, return ret; } - mutex_lock(&BTRFS_I(inode)->log_mutex); + if (inode_only == LOG_OTHER_INODE) { + inode_only = LOG_INODE_EXISTS; + mutex_lock_nested(&BTRFS_I(inode)->log_mutex, + SINGLE_DEPTH_NESTING); + } else { + mutex_lock(&BTRFS_I(inode)->log_mutex); + } /* * a brute force approach to making sure we get the most uptodate @@ -4799,7 +4806,7 @@ static int btrfs_log_inode(struct btrfs_trans_handle *trans, * unpin it. */ err = btrfs_log_inode(trans, root, other_inode, - LOG_INODE_EXISTS, + LOG_OTHER_INODE, 0, LLONG_MAX, ctx); iput(other_inode); if (err) -- 2.11.0