5 files changed, 34 insertions, 10 deletions

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 05be59ae21b2..6ae2329052c9 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -265,6 +265,7 @@ struct bcache_device {
 #define BCACHE_DEV_WB_RUNNING		3
 #define BCACHE_DEV_RATE_DW_RUNNING	4
 	int			nr_stripes;
+#define BCH_MIN_STRIPE_SZ		((4 << 20) >> SECTOR_SHIFT)
 	unsigned int		stripe_size;
 	atomic_t		*stripe_sectors_dirty;
 	unsigned long		*full_dirty_stripes;
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index ae5cbb55861f..261596791218 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1000,6 +1000,9 @@ err:
  *
  * The btree node will have either a read or a write lock held, depending on
  * level and op->lock.
+ *
+ * Note: Only error code or btree pointer will be returned, it is unncessary
+ *       for callers to check NULL pointer.
  */
 struct btree *bch_btree_node_get(struct cache_set *c, struct btree_op *op,
 				 struct bkey *k, int level, bool write,
@@ -1111,6 +1114,10 @@ retry:
 	mutex_unlock(&b->c->bucket_lock);
 }
 
+/*
+ * Only error code or btree pointer will be returned, it is unncessary for
+ * callers to check NULL pointer.
+ */
 struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op,
 				     int level, bool wait,
 				     struct btree *parent)
@@ -1368,7 +1375,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
 	memset(new_nodes, 0, sizeof(new_nodes));
 	closure_init_stack(&cl);
 
-	while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b))
+	while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b))
 		keys += r[nodes++].keys;
 
 	blocks = btree_default_blocks(b->c) * 2 / 3;
@@ -1515,7 +1522,7 @@ out_nocoalesce:
 	bch_keylist_free(&keylist);
 
 	for (i = 0; i < nodes; i++)
-		if (!IS_ERR(new_nodes[i])) {
+		if (!IS_ERR_OR_NULL(new_nodes[i])) {
 			btree_node_free(new_nodes[i]);
 			rw_unlock(true, new_nodes[i]);
 		}
@@ -1532,6 +1539,8 @@ static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
 		return 0;
 
 	n = btree_node_alloc_replacement(replace, NULL);
+	if (IS_ERR(n))
+		return 0;
 
 	/* recheck reserve after allocating replacement node */
 	if (btree_check_reserve(b, NULL)) {
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 8bd899766372..bfe1685dbae5 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -905,6 +905,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned int block_size,
 
 	if (!d->stripe_size)
 		d->stripe_size = 1 << 31;
+	else if (d->stripe_size < BCH_MIN_STRIPE_SZ)
+		d->stripe_size = roundup(BCH_MIN_STRIPE_SZ, d->stripe_size);
 
 	n = DIV_ROUND_UP_ULL(sectors, d->stripe_size);
 	if (!n || n > max_stripes) {
@@ -2016,7 +2018,7 @@ static int run_cache_set(struct cache_set *c)
 		c->root = bch_btree_node_get(c, NULL, k,
 					     j->btree_level,
 					     true, NULL);
-		if (IS_ERR_OR_NULL(c->root))
+		if (IS_ERR(c->root))
 			goto err;
 
 		list_del_init(&c->root->list);
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 45d8af755de6..a438efb66069 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -1104,7 +1104,7 @@ SHOW(__bch_cache)
 			sum += INITIAL_PRIO - cached[i];
 
 		if (n)
-			do_div(sum, n);
+			sum = div64_u64(sum, n);
 
 		for (i = 0; i < ARRAY_SIZE(q); i++)
 			q[i] = INITIAL_PRIO - cached[n * (i + 1) /
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 24c049067f61..3accfdaee6b1 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -913,7 +913,7 @@ static int bch_dirty_init_thread(void *arg)
 	int cur_idx, prev_idx, skip_nr;
 
 	k = p = NULL;
-	cur_idx = prev_idx = 0;
+	prev_idx = 0;
 
 	bch_btree_iter_init(&c->root->keys, &iter, NULL);
 	k = bch_btree_iter_next_filter(&iter, &c->root->keys, bch_ptr_bad);
@@ -977,24 +977,35 @@ static int bch_btre_dirty_init_thread_nr(void)
 void bch_sectors_dirty_init(struct bcache_device *d)
 {
 	int i;
+	struct btree *b = NULL;
 	struct bkey *k = NULL;
 	struct btree_iter iter;
 	struct sectors_dirty_init op;
 	struct cache_set *c = d->c;
 	struct bch_dirty_init_state state;
 
+retry_lock:
+	b = c->root;
+	rw_lock(0, b, b->level);
+	if (b != c->root) {
+		rw_unlock(0, b);
+		goto retry_lock;
+	}
+
 	/* Just count root keys if no leaf node */
-	rw_lock(0, c->root, c->root->level);
 	if (c->root->level == 0) {
 		bch_btree_op_init(&op.op, -1);
 		op.inode = d->id;
 		op.count = 0;
 
 		for_each_key_filter(&c->root->keys,
-				    k, &iter, bch_ptr_invalid)
+				    k, &iter, bch_ptr_invalid) {
+			if (KEY_INODE(k) != op.inode)
+				continue;
 			sectors_dirty_init_fn(&op.op, c->root, k);
+		}
 
-		rw_unlock(0, c->root);
+		rw_unlock(0, b);
 		return;
 	}
 
@@ -1014,23 +1025,24 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 		if (atomic_read(&state.enough))
 			break;
 
+		atomic_inc(&state.started);
 		state.infos[i].state = &state;
 		state.infos[i].thread =
 			kthread_run(bch_dirty_init_thread, &state.infos[i],
 				    "bch_dirtcnt[%d]", i);
 		if (IS_ERR(state.infos[i].thread)) {
 			pr_err("fails to run thread bch_dirty_init[%d]\n", i);
+			atomic_dec(&state.started);
 			for (--i; i >= 0; i--)
 				kthread_stop(state.infos[i].thread);
 			goto out;
 		}
-		atomic_inc(&state.started);
 	}
 
 out:
 	/* Must wait for all threads to stop. */
 	wait_event(state.wait, atomic_read(&state.started) == 0);
-	rw_unlock(0, c->root);
+	rw_unlock(0, b);
 }
 
 void bch_cached_dev_writeback_init(struct cached_dev *dc)