Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux...

[karo-tx-linux.git] / fs / btrfs / volumes.c

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6b9cff42265d06e5b26a7ed53684a5551675a930..2854c824ab6443d04eac19cf0b540f79c257cfa0 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -684,6 +684,12 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
                __btrfs_close_devices(fs_devices);
                free_fs_devices(fs_devices);
        }
+       /*
+        * Wait for rcu kworkers under __btrfs_close_devices
+        * to finish all blkdev_puts so device is really
+        * free when umount is done.
+        */
+       rcu_barrier();
        return ret;
 }
 
@@ -4929,7 +4935,18 @@ int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
        em = lookup_extent_mapping(em_tree, chunk_start, 1);
        read_unlock(&em_tree->lock);
 
-       BUG_ON(!em || em->start != chunk_start);
+       if (!em) {
+               printk(KERN_ERR "btrfs: couldn't find em for chunk %Lu\n",
+                      chunk_start);
+               return -EIO;
+       }
+
+       if (em->start != chunk_start) {
+               printk(KERN_ERR "btrfs: bad chunk start, em=%Lu, wanted=%Lu\n",
+                      em->start, chunk_start);
+               free_extent_map(em);
+               return -EIO;
+       }
        map = (struct map_lookup *)em->bdev;
 
        length = em->len;