From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 7 Sep 2018 19:14:59 +0200 From: Valentin Vidic To: drbd-user@lists.linbit.com Cc: Jens Axboe , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-block@vger.kernel.org, xen-devel@lists.xenproject.org, Roger Pau =?iso-8859-1?Q?Monn=E9?= Message-ID: <20180907171459.GO26705@gavran.carpriv.carnet.hr> References: <20180829065214.23546-1-Valentin.Vidic@CARNet.hr> <20180905103649.edugijsjx4v2fbxd@mac.bytemobile.com> <20180905162756.GA26705@gavran.carpriv.carnet.hr> <20180907120337.GB11834@soda.linbit> <20180907121348.GM26705@gavran.carpriv.carnet.hr> <20180907132828.GC11834@soda.linbit> <20180907164500.GN26705@gavran.carpriv.carnet.hr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180907164500.GN26705@gavran.carpriv.carnet.hr> Subject: Re: [DRBD-user] [PATCH] xen-blkback: Switch to closed state after releasing the backing device List-ID: On Fri, Sep 07, 2018 at 06:45:00PM +0200, Valentin Vidic wrote: > Adding a dump_stack in drbd_release gives two possible code paths, > both from xen_blkback and the first one from workqueue being the > problematic one: In fact the first one is the original code path before I modified blkback. The problem is it gets executed async from workqueue so it might not always run before the call to drbdadm secondary. > [ 530.698782] CPU: 0 PID: 4 Comm: kworker/0:0 Tainted: G O 4.9.0-8-amd64 #1 Debian 4.9.110-3+deb9u4 > [ 530.698783] Hardware name: HP ProLiant BL460c Gen9, BIOS I36 09/12/2016 > [ 530.698784] Workqueue: events xen_blkif_deferred_free [xen_blkback] > [ 530.698785] 0000000000000000 ffffffff81331e54 ffff883f82143800 ffff883f741b5660 > [ 530.698787] ffffffffc03a309e ffff883f741b5580 ffffffff81245ca8 0000000281a186b5 > [ 530.698789] 000000008935f100 8412ffa31a64cc4c 000000000000020a ffff883fa6218280 > [ 530.698791] Call Trace: > [ 530.698792] [] ? dump_stack+0x5c/0x78 > [ 530.698805] [] ? drbd_release+0x1e/0x40 [drbd] > [ 530.698810] [] ? __blkdev_put+0x1e8/0x2a0 > [ 530.698813] [] ? xen_vbd_free.isra.9+0x48/0x60 [xen_blkback] > [ 530.698814] [] ? xen_blkif_deferred_free+0x27/0x70 [xen_blkback] > [ 530.698816] [] ? process_one_work+0x18a/0x420 > [ 530.698817] [] ? worker_thread+0x4d/0x490 > [ 530.698818] [] ? process_one_work+0x420/0x420 > [ 530.698820] [] ? kthread+0xd9/0xf0 > [ 530.698822] [] ? kthread_park+0x60/0x60 > [ 530.698823] [] ? ret_from_fork+0x57/0x70 -- Valentin