From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH v3] scsi, block: fix duplicate bdi name registration crashes Date: Thu, 2 Feb 2017 08:23:55 -0700 Message-ID: <07c52003-cd32-ee02-1d73-64586de7e9eb@kernel.dk> References: <148598661794.11527.10024529085859239448.stgit@dwillia2-desk3.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-it0-f43.google.com ([209.85.214.43]:36756 "EHLO mail-it0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751143AbdBBPX6 (ORCPT ); Thu, 2 Feb 2017 10:23:58 -0500 Received: by mail-it0-f43.google.com with SMTP id c7so41513620itd.1 for ; Thu, 02 Feb 2017 07:23:57 -0800 (PST) In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Dan Williams Cc: "Martin K. Petersen" , linux-block@vger.kernel.org, Jan Kara , linux-scsi , "linux-kernel@vger.kernel.org" , Christoph Hellwig , James Bottomley , Bart Van Assche , Omar Sandoval , Omar Sandoval On 02/01/2017 03:43 PM, Jens Axboe wrote: > On 02/01/2017 02:40 PM, Dan Williams wrote: >> On Wed, Feb 1, 2017 at 2:35 PM, Jens Axboe wrote: >>> On 02/01/2017 02:05 PM, Dan Williams wrote: >>>> Warnings of the following form occur because scsi reuses a devt number >>>> while the block layer still has it referenced as the name of the bdi >>>> [1]: >>>> >>>> WARNING: CPU: 1 PID: 93 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80 >>>> sysfs: cannot create duplicate filename '/devices/virtual/bdi/8:192' >>>> [..] >>>> Call Trace: >>>> dump_stack+0x86/0xc3 >>>> __warn+0xcb/0xf0 >>>> warn_slowpath_fmt+0x5f/0x80 >>>> ? kernfs_path_from_node+0x4f/0x60 >>>> sysfs_warn_dup+0x62/0x80 >>>> sysfs_create_dir_ns+0x77/0x90 >>>> kobject_add_internal+0xb2/0x350 >>>> kobject_add+0x75/0xd0 >>>> device_add+0x15a/0x650 >>>> device_create_groups_vargs+0xe0/0xf0 >>>> device_create_vargs+0x1c/0x20 >>>> bdi_register+0x90/0x240 >>>> ? lockdep_init_map+0x57/0x200 >>>> bdi_register_owner+0x36/0x60 >>>> device_add_disk+0x1bb/0x4e0 >>>> ? __pm_runtime_use_autosuspend+0x5c/0x70 >>>> sd_probe_async+0x10d/0x1c0 >>>> async_run_entry_fn+0x39/0x170 >>>> >>>> This is a brute-force fix to pass the devt release information from >>>> sd_probe() to the locations where we register the bdi, >>>> device_add_disk(), and unregister the bdi, blk_cleanup_queue(). >>>> >>>> Thanks to Omar for the quick reproducer script [2]. This patch survives >>>> where an unmodified kernel fails in a few seconds. >>> >>> What is the patch against? Doesn't seem to apply cleanly for me on >>> master, nor the 4.11 block tree. >>> >> >> I built it on top of Jan's bdi fixes series [1]. I can rebase to >> block/for-next, just let me know which patches you want to take first. >> >> [1]: http://marc.info/?l=linux-block&m=148586843819160&w=2 > > Ah, no that's fine, we'll just pull Jan's stuff in first. Makes sense. Both are now applied, thanks Dan. -- Jens Axboe