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

[Jan Kara <jack@suse.cz>]

On Thu 16-09-10 20:33:39, Jens Axboe wrote:
> 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?
  OK with me. Thanks.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR