Re: FIle copy to FAT FS on NVDIMM hits BUG_ON at fs/buffer.c:3305!

["Kani, Toshimitsu" <toshi.kani@hpe.com>]

On Thu, 2017-07-27 at 16:12 +0000, Kani, Toshimitsu wrote:
> On Wed, 2017-07-26 at 10:11 -0700, Matthew Wilcox wrote:
> > On Wed, Jul 26, 2017 at 06:23:08PM +0900, OGAWA Hirofumi wrote:
> > > The locking of this path seems to be broken. The guy familiar to
> > > bdev_write_page() path will made real fix though, The following
> > > patch should be explaining enough what is wrong.
> > > 
> > > In short, clean_buffers() must be called before unlocking
> > > lock_page().
> > 
> > Thanks for that.  This should fix the problem while not leaking the
> > unlock_page call outside bdev_write_page.
> > 
> > --- 8< ---
> > 
> > Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
> 
> Thanks Willy and Hirofumi for the quick fix!  I've tested the change,
> and it works fine.
> 
> Tested-by: Toshi Kani <toshi.kani@hpe.com>

Since removing rw_page would have to wait till 4.15, can we go with this
fix for 4.14?  I confirmed that Matthew's patch [1] applies cleanly to
4.14-rc1.  This patch can also be applied to stable kernels.

Matthew, can you resend this patch with description?

[1] https://www.spinics.net/lists/linux-fsdevel/msg113835.html

Thanks,
-Toshi