On Tue, Feb 28, 2017 at 11:41:43PM +0800, Ming Lei wrote: > The cost is 128bytes(8*16) stack space in kernel thread context, and > just use the bio helper to retrieve pages from bio. > > Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx> > --- > drivers/md/raid10.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c > index 0b97631e3905..6ffb64ab45f8 100644 > --- a/drivers/md/raid10.c > +++ b/drivers/md/raid10.c > @@ -4670,7 +4670,15 @@ static int handle_reshape_read_error(struct mddev *mddev, > struct r10bio *r10b = &on_stack.r10_bio; > int slot = 0; > int idx = 0; > - struct bio_vec *bvec = r10_bio->master_bio->bi_io_vec; > + struct bio_vec *bvl; > + struct page *pages[RESYNC_PAGES]; > + > + /* > + * This bio is allocated in reshape_request(), and size > + * is still RESYNC_PAGES > + */ > + bio_for_each_segment_all(bvl, r10_bio->master_bio, idx) > + pages[idx] = bvl->bv_page; The reshape bio is doing IO against the memory we allocated for r10_bio, I'm wondering why we can't get the pages from r10_bio. In this way, we don't need access the bio_vec any more. Thanks, Shaohua > r10b->sector = r10_bio->sector; > __raid10_find_phys(&conf->prev, r10b); > @@ -4699,7 +4707,7 @@ static int handle_reshape_read_error(struct mddev *mddev, > success = sync_page_io(rdev, > addr, > s << 9, > - bvec[idx].bv_page, > + pages[idx], > REQ_OP_READ, 0, false); > rdev_dec_pending(rdev, mddev); > rcu_read_lock(); > -- > 2.7.4 >
