From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com ([156.151.31.81]:24646 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751027AbcIIIb0 (ORCPT ); Fri, 9 Sep 2016 04:31:26 -0400 Subject: Re: Another 4.8-rc locked splat: btrfs_close_devices() To: Ilya Dryomov , Chris Mason , David Sterba References: <36933898-3295-a9ae-aefd-3483333743dc@oracle.com> Cc: linux-btrfs@vger.kernel.org From: Anand Jain Message-ID: Date: Fri, 9 Sep 2016 16:33:01 +0800 MIME-Version: 1.0 In-Reply-To: <36933898-3295-a9ae-aefd-3483333743dc@oracle.com> Content-Type: text/plain; charset=windows-1252; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Looks like we need to take time to clean up device_list_mutex, chunk_mutex, volume_mutex and rcu. As of now I have sent out, [PATCH] btrfs: fix a possible umount deadlock This has passed xfstests/btrfs. Thanks, Anand On 09/09/2016 08:38 AM, Anand Jain wrote: > > Thanks for the report Ilya. > > Yep. Have seen similar issues during hotspare fixes as well. > Where the vfs call to btrfs_show_devname() and its > device_list_mutex lock is conflicting. One of that is fixed > here. > > ------ > 779bf3fefa835cb52a07457c8acac6f2f66f2493 > btrfs: fix lock dep warning, move scratch dev out of > device_list_mutex and uuid_mutex > ------ > > I was kind of expecting this here as well when wrote 142388194191. > However couldn't reproduce. > > To fix this permanently, I see the following choices, > > Chris/David, > > 1. Do you think device_list_mutex is needed at btrfs_show_devname() > or rcu should suffice. ? > > 2. To me the roles of fs_info->volume_mutex can be replaced with > device_list_mutex. Any idea, if I am missing something ? > > Thanks, Anand > > > On 09/08/2016 10:34 PM, Ilya Dryomov wrote: >> Hello, >> >> This one seems to have appeared after Anand's commit >> 142388194191 ("btrfs: do not background blkdev_put()") got merged into >> 4.8-rc4. >> >> Thanks, >> >> Ilya >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html