Re: [PATCH V10 11/19] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages()

2018-11-19 Thread Ming Lei
On Fri, Nov 16, 2018 at 02:46:45PM +0100, Christoph Hellwig wrote:
> > -   bio_for_each_segment_all(bv, bio, i) {
> > +   for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++) {
> 
> This really needs a comment.  Otherwise it looks fine to me.

OK, will do it in next version.

Thanks,
Ming


Re: [PATCH V10 11/19] bcache: avoid to use bio_for_each_segment_all() in bch_bio_alloc_pages()

2018-11-19 Thread Ming Lei
On Thu, Nov 15, 2018 at 04:44:02PM -0800, Omar Sandoval wrote:
> On Thu, Nov 15, 2018 at 04:52:58PM +0800, Ming Lei wrote:
> > bch_bio_alloc_pages() is always called on one new bio, so it is safe
> > to access the bvec table directly. Given it is the only kind of this
> > case, open code the bvec table access since bio_for_each_segment_all()
> > will be changed to support for iterating over multipage bvec.
> > 
> > Cc: Dave Chinner 
> > Cc: Kent Overstreet 
> > Acked-by: Coly Li 
> > Cc: Mike Snitzer 
> > Cc: dm-de...@redhat.com
> > Cc: Alexander Viro 
> > Cc: linux-fsde...@vger.kernel.org
> > Cc: Shaohua Li 
> > Cc: linux-r...@vger.kernel.org
> > Cc: linux-er...@lists.ozlabs.org
> > Cc: David Sterba 
> > Cc: linux-bt...@vger.kernel.org
> > Cc: Darrick J. Wong 
> > Cc: linux-...@vger.kernel.org
> > Cc: Gao Xiang 
> > Cc: Christoph Hellwig 
> > Cc: Theodore Ts'o 
> > Cc: linux-e...@vger.kernel.org
> > Cc: Coly Li 
> > Cc: linux-bca...@vger.kernel.org
> > Cc: Boaz Harrosh 
> > Cc: Bob Peterson 
> > Cc: cluster-de...@redhat.com
> > Signed-off-by: Ming Lei 
> > ---
> >  drivers/md/bcache/util.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/md/bcache/util.c b/drivers/md/bcache/util.c
> > index 20eddeac1531..8517aebcda2d 100644
> > --- a/drivers/md/bcache/util.c
> > +++ b/drivers/md/bcache/util.c
> > @@ -270,7 +270,7 @@ int bch_bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
> > int i;
> > struct bio_vec *bv;
> >  
> > -   bio_for_each_segment_all(bv, bio, i) {
> > +   for (i = 0, bv = bio->bi_io_vec; i < bio->bi_vcnt; bv++) {
> 
> This is missing an i++.

Good catch, will fix it in next version.

thanks,
Ming