Re: [PATCH v3] scsi, block: fix duplicate bdi name registration crashes

From: Jens Axboe
Date: Wed Feb 01 2017 - 17:35:35 EST


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.

--
Jens Axboe