1 files changed, 37 insertions, 4 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index be90596a9e2a..4c340c85b122 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1641,7 +1641,7 @@ static void btree_gc_start(struct cache_set *c)
         mutex_unlock(&c->bucket_lock);
 }
 
-size_t bch_btree_gc_finish(struct cache_set *c)
+static size_t bch_btree_gc_finish(struct cache_set *c)
 {
         size_t available = 0;
         struct bucket *b;
@@ -1703,9 +1703,6 @@ size_t bch_btree_gc_finish(struct cache_set *c)
 
                         if (!GC_MARK(b) || GC_MARK(b) == GC_MARK_RECLAIMABLE)
                                 available++;
-
-                        if (!GC_MARK(b))
-                                bch_bucket_add_unused(ca, b);
                 }
         }
 
@@ -1836,6 +1833,42 @@ int bch_btree_check(struct cache_set *c)
         return btree_root(check_recurse, c, &op);
 }
 
+void bch_initial_gc_finish(struct cache_set *c)
+{
+        struct cache *ca;
+        struct bucket *b;
+        unsigned i;
+
+        bch_btree_gc_finish(c);
+
+        mutex_lock(&c->bucket_lock);
+
+        /*
+         * We need to put some unused buckets directly on the prio freelist in
+         * order to get the allocator thread started - it needs freed buckets in
+         * order to rewrite the prios and gens, and it needs to rewrite prios
+         * and gens in order to free buckets.
+         *
+         * This is only safe for buckets that have no live data in them, which
+         * there should always be some of.
+         */
+        for_each_cache(ca, c, i) {
+                for_each_bucket(b, ca) {
+                        if (fifo_full(&ca->free[RESERVE_PRIO]))
+                                break;
+
+                        if (bch_can_invalidate_bucket(ca, b) &&
+                            !GC_MARK(b)) {
+                                __bch_invalidate_one_bucket(ca, b);
+                                fifo_push(&ca->free[RESERVE_PRIO],
+                                          b - ca->buckets);
+                        }
+                }
+        }
+
+        mutex_unlock(&c->bucket_lock);
+}
+
 /* Btree insertion */
 
 static bool btree_insert_key(struct btree *b, struct bkey *k,