1 files changed, 9 insertions, 1 deletions

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 0ddc5659f946..9f363e17ec74 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -418,12 +418,17 @@ static struct reada_extent *reada_find_extent(struct btrfs_root *root,
                          */
                         continue;
                 }
+                if (!dev->bdev) {
+                        /* cannot read ahead on missing device */
+                        continue;
+                }
                 prev_dev = dev;
                 ret = radix_tree_insert(&dev->reada_extents, index, re);
                 if (ret) {
                         while (--i >= 0) {
                                 dev = bbio->stripes[i].dev;
                                 BUG_ON(dev == NULL);
+                                /* ignore whether the entry was inserted */
                                 radix_tree_delete(&dev->reada_extents, index);
                         }
                         BUG_ON(fs_info == NULL);
@@ -914,7 +919,10 @@ struct reada_control *btrfs_reada_add(struct btrfs_root *root,
         generation = btrfs_header_generation(node);
         free_extent_buffer(node);
 
-        reada_add_block(rc, start, &max_key, level, generation);
+        if (reada_add_block(rc, start, &max_key, level, generation)) {
+                kfree(rc);
+                return ERR_PTR(-ENOMEM);
+        }
 
         reada_start_machine(root->fs_info);