From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [RFC PATCH] scsi, block: fix duplicate bdi name registration crashes Date: Mon, 30 Jan 2017 08:05:52 +0100 Message-ID: <59c1938d-14fc-db2f-b1ea-303c5c2d1f11@suse.de> References: <148566590827.1627.3631056985359212959.stgit@dwillia2-desk3.amr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <148566590827.1627.3631056985359212959.stgit@dwillia2-desk3.amr.corp.intel.com> Sender: linux-block-owner@vger.kernel.org To: Dan Williams , martin.petersen@oracle.com Cc: Jens Axboe , linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, James Bottomley , Bart Van Assche , Omar Sandoval , Christoph Hellwig List-Id: linux-scsi@vger.kernel.org On 01/29/2017 05:58 AM, 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. > > [1]: https://marc.info/?l=linux-scsi&m=147116857810716&w=4 > [2]: http://marc.info/?l=linux-block&m=148554717109098&w=2 > > Cc: James Bottomley > Cc: Bart Van Assche > Cc: "Martin K. Petersen" > Cc: Christoph Hellwig > Cc: Jens Axboe > Reported-by: Omar Sandoval > Signed-off-by: Dan Williams > --- > block/blk-core.c | 1 + > block/genhd.c | 7 +++++++ > drivers/scsi/sd.c | 41 +++++++++++++++++++++++++++++++++-------- > include/linux/blkdev.h | 1 + > include/linux/genhd.h | 17 +++++++++++++++++ > 5 files changed, 59 insertions(+), 8 deletions(-) > Please check the patchset from Jan Kara (cf 'BDI lifetime fix' on linux-block), which attempts to solve the same problem. Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)