raid5: need to set STRIPE_HANDLE for batch head

With commit 6ce220dd2f8ea71d6afc29b9a7524c12e39f374a ("raid5: don't set
STRIPE_HANDLE to stripe which is in batch list"), we don't want to set
STRIPE_HANDLE flag for sh which is already in batch list.

However, the stripe which is the head of batch list should set this flag,
otherwise panic could happen inside init_stripe at BUG_ON(sh->batch_head),
it is reproducible with raid5 on top of nvdimm devices per Xiao oberserved.

Thanks for Xiao's effort to verify the change.

Fixes: 6ce220dd2f8ea ("raid5: don't set STRIPE_HANDLE to stripe which is in batch list")
Reported-by: Xiao Ni <xni@redhat.com>
Tested-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index f0fc538bfe597f7a1179b31eeaa8a8bfa837101a..d4d3b67ffbba7c7b57b142efb5f9441d8511c9a1 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5726,7 +5726,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
                                do_flush = false;
                        }
 
-                       if (!sh->batch_head)
+                       if (!sh->batch_head || sh == sh->batch_head)
                                set_bit(STRIPE_HANDLE, &sh->state);
                        clear_bit(STRIPE_DELAYED, &sh->state);
                        if ((!sh->batch_head || sh == sh->batch_head) &&