Re: [PATCH] block: Fix race during disk initialization

[Jens Axboe <axboe@kernel.dk>]

On 2010-09-16 20:20, Jan Kara wrote:
> When a new disk is being discovered, add_disk() first ties the bdev to gendisk
> (via register_disk()->blkdev_get()) and only after that calls
> bdi_register_bdev(). Because register_disk() also creates disk's kobject, it
> can happen that userspace manages to open and modify the device's data (or
> inode) before its BDI is properly initialized leading to a warning in
> __mark_inode_dirty().
> 
> Fix the problem by registering BDI early enough.
> 
> This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=16312
> 
> Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  block/genhd.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
>  Jens, would you consider merging this fix? The kernel boots with it but
> I'm not too familiar with this area of kernel so there can be something subtle
> I've missed. So please review. Thanks.

It looks sane. How about we add it to the .37 lineup and mark it for
stable backport?

-- 
Jens Axboe