From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:35699 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757536AbbGQKXR (ORCPT ); Fri, 17 Jul 2015 06:23:17 -0400 Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id t6HANG7L032245 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 17 Jul 2015 10:23:16 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0021.oracle.com (8.13.8/8.13.8) with ESMTP id t6HANGi4011092 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Fri, 17 Jul 2015 10:23:16 GMT Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0121.oracle.com (8.13.8/8.13.8) with ESMTP id t6HANG6i031180 for ; Fri, 17 Jul 2015 10:23:16 GMT Message-ID: <55A8D791.2010402@oracle.com> Date: Fri, 17 Jul 2015 18:23:13 +0800 From: Anand Jain MIME-Version: 1.0 To: Liu Bo , linux-btrfs@vger.kernel.org Subject: Re: [PATCH 1/2] Btrfs: move kobj stuff out of dev_replace lock range References: <1437122959-23376-1-git-send-email-bo.li.liu@oracle.com> In-Reply-To: <1437122959-23376-1-git-send-email-bo.li.liu@oracle.com> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 07/17/2015 04:49 PM, Liu Bo wrote: > To avoid deadlock described in commit 084b6e7c7607 ("btrfs: Fix a lockdep warning when running xfstest."), > we should move kobj stuff out of dev_replace lock range. Is this just a lock optimizing patch or fixing _a_ cause for the deadlock. ? Am I missing something? Thanks, Anand > Signed-off-by: Liu Bo > --- > fs/btrfs/dev-replace.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c > index 862fbc2..9eb1401 100644 > --- a/fs/btrfs/dev-replace.c > +++ b/fs/btrfs/dev-replace.c > @@ -376,10 +376,6 @@ int btrfs_dev_replace_start(struct btrfs_root *root, > WARN_ON(!tgt_device); > dev_replace->tgtdev = tgt_device; > > - ret = btrfs_kobj_add_device(tgt_device->fs_devices, tgt_device); > - if (ret) > - btrfs_error(root->fs_info, ret, "kobj add dev failed"); > - > printk_in_rcu(KERN_INFO > "BTRFS: dev_replace from %s (devid %llu) to %s started\n", > src_device->missing ? "" : > @@ -402,6 +398,10 @@ int btrfs_dev_replace_start(struct btrfs_root *root, > args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR; > btrfs_dev_replace_unlock(dev_replace); > > + ret = btrfs_kobj_add_device(tgt_device->fs_devices, tgt_device); > + if (ret) > + btrfs_error(root->fs_info, ret, "kobj add dev failed"); > + > btrfs_wait_ordered_roots(root->fs_info, -1); > > /* force writing the updated state information to disk */ >