raid5: get_active_stripe avoids device_lock

[linux.git] / drivers / md / raid5.c

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index a904a2c80fc83fc5651fe7f26ed37cd40bb37224..25247a8529124f7cc93eda0db7033655d52f2ef7 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -679,14 +679,9 @@ get_active_stripe(struct r5conf *conf, sector_t sector,
                                init_stripe(sh, sector, previous);
                                atomic_inc(&sh->count);
                        }
-               } else {
+               } else if (!atomic_inc_not_zero(&sh->count)) {
                        spin_lock(&conf->device_lock);
-                       if (atomic_read(&sh->count)) {
-                               BUG_ON(!list_empty(&sh->lru)
-                                   && !test_bit(STRIPE_EXPANDING, &sh->state)
-                                   && !test_bit(STRIPE_ON_UNPLUG_LIST, &sh->state)
-                                       );
-                       } else {
+                       if (!atomic_read(&sh->count)) {
                                if (!test_bit(STRIPE_HANDLE, &sh->state))
                                        atomic_inc(&conf->active_stripes);
                                BUG_ON(list_empty(&sh->lru) &&