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

[Dan Williams]

On Wed, Feb 1, 2017 at 2:35 PM, Jens Axboe <axboe@xxxxxxxxx> 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