md/raid5: more incorrect BUG_ON in handle_stripe_fill.

It is not incorrect to call handle_stripe_fill() when
a batch of full-stripe writes is active.
It is, however, a BUG if fetch_block() then decides
it needs to actually fetch anything.

So move the 'BUG_ON' to where it belongs.

Signed-off-by: NeilBrown  <neilb@suse.de>
Fixes: 59fc630b8b5f ("RAID5: batch adjacent full stripe write")

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 91a1e8b..415cac6 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3302,6 +3302,7 @@ static int fetch_block(struct stripe_head *sh, struct stripe_head_state *s,
                 */
                BUG_ON(test_bit(R5_Wantcompute, &dev->flags));
                BUG_ON(test_bit(R5_Wantread, &dev->flags));
+               BUG_ON(sh->batch_head);
                if ((s->uptodate == disks - 1) &&
                    (s->failed && (disk_idx == s->failed_num[0] ||
                                   disk_idx == s->failed_num[1]))) {
@@ -3370,7 +3371,6 @@ static void handle_stripe_fill(struct stripe_head *sh,
 {
        int i;
 
-       BUG_ON(sh->batch_head);
        /* look for blocks to read/compute, skip this if a compute
         * is already in flight, or if the stripe contents are in the
         * midst of changing due to a write