Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

Pull MD fixes from Shaohua Li:
 "Two small patches to fix long-lived raid5 stripe batch bugs, one from
  Dennis and the other from me"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid5: preserve STRIPE_ON_UNPLUG_LIST in break_stripe_batch_list
  md/raid5: fix a race condition in stripe batch

1 files changed, 10 insertions, 3 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 4188a4881148..076409455b60 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -811,6 +811,14 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh
                         spin_unlock(&head->batch_head->batch_lock);
                         goto unlock_out;
                 }
+                /*
+                 * We must assign batch_head of this stripe within the
+                 * batch_lock, otherwise clear_batch_ready of batch head
+                 * stripe could clear BATCH_READY bit of this stripe and
+                 * this stripe->batch_head doesn't get assigned, which
+                 * could confuse clear_batch_ready for this stripe
+                 */
+                sh->batch_head = head->batch_head;
 
                 /*
                  * at this point, head's BATCH_READY could be cleared, but we
@@ -818,8 +826,6 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh
                  */
                 list_add(&sh->batch_list, &head->batch_list);
                 spin_unlock(&head->batch_head->batch_lock);
-
-                sh->batch_head = head->batch_head;
         } else {
                 head->batch_head = head;
                 sh->batch_head = head->batch_head;
@@ -4599,7 +4605,8 @@ static void break_stripe_batch_list(struct stripe_head *head_sh,
 
                 set_mask_bits(&sh->state, ~(STRIPE_EXPAND_SYNC_FLAGS |
                                             (1 << STRIPE_PREREAD_ACTIVE) |
-                                            (1 << STRIPE_DEGRADED)),
+                                            (1 << STRIPE_DEGRADED) |
+                                            (1 << STRIPE_ON_UNPLUG_LIST)),
                               head_sh->state & (1 << STRIPE_INSYNC));
 
                 sh->check_state = head_sh->check_state;