md: raid10: avoid direct access to bvec table in handle_reshape_read_error

All reshape I/O share pages from 1st copy device, so just use that pages
for avoiding direct access to bvec table in handle_reshape_read_error.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Shaohua Li <shli@fb.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 827bb5bef53c..0f13d57ef646 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -4653,7 +4653,10 @@ 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 page **pages;
+
+        /* reshape IOs share pages from .devs[0].bio */
+        pages = get_resync_pages(r10_bio->devs[0].bio)->pages;
 
         r10b->sector = r10_bio->sector;
         __raid10_find_phys(&conf->prev, r10b);
@@ -4682,7 +4685,7 @@ 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();