1 files changed, 17 insertions, 4 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 038a5229404a..ed1f7ce7219a 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2945,6 +2945,9 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
                 list_del_init(&em->list);
                 if (em->generation <= test_gen)
                         continue;
+                /* Need a ref to keep it from getting evicted from cache */
+                atomic_inc(&em->refs);
+                set_bit(EXTENT_FLAG_LOGGING, &em->flags);
                 list_add_tail(&em->list, &extents);
         }
 
@@ -2954,13 +2957,18 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
                 em = list_entry(extents.next, struct extent_map, list);
 
                 list_del_init(&em->list);
+                clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
 
                 /*
                  * If we had an error we just need to delete everybody from our
                  * private list.
                  */
-                if (ret)
+                if (ret) {
+                        free_extent_map(em);
                         continue;
+                }
+
+                write_unlock(&tree->lock);
 
                 /*
                  * If the previous EM and the last extent we left off on aren't
@@ -2971,21 +2979,26 @@ static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
                         ret = copy_items(trans, inode, dst_path, args.src,
                                          args.start_slot, args.nr,
                                          LOG_INODE_ALL);
-                        if (ret)
+                        if (ret) {
+                                free_extent_map(em);
+                                write_lock(&tree->lock);
                                 continue;
+                        }
                         btrfs_release_path(path);
                         args.nr = 0;
                 }
 
                 ret = log_one_extent(trans, inode, root, em, path, dst_path, &args);
+                free_extent_map(em);
+                write_lock(&tree->lock);
         }
+        WARN_ON(!list_empty(&extents));
+        write_unlock(&tree->lock);
 
         if (!ret && args.nr)
                 ret = copy_items(trans, inode, dst_path, args.src,
                                  args.start_slot, args.nr, LOG_INODE_ALL);
         btrfs_release_path(path);
-        WARN_ON(!list_empty(&extents));
-        write_unlock(&tree->lock);
         return ret;
 }