Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[cascardo/linux.git] / fs / btrfs / extent_map.c

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 2834ca5..a4a7a1a 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -174,6 +174,14 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next)
            test_bit(EXTENT_FLAG_LOGGING, &next->flags))
                return 0;
 
+       /*
+        * We don't want to merge stuff that hasn't been written to the log yet
+        * since it may not reflect exactly what is on disk, and that would be
+        * bad.
+        */
+       if (!list_empty(&prev->list) || !list_empty(&next->list))
+               return 0;
+
        if (extent_map_end(prev) == next->start &&
            prev->flags == next->flags &&
            prev->bdev == next->bdev &&
@@ -209,9 +217,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
                        em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
                        em->mod_start = merge->mod_start;
                        em->generation = max(em->generation, merge->generation);
-                       list_move(&em->list, &tree->modified_extents);
 
-                       list_del_init(&merge->list);
                        rb_erase(&merge->rb_node, &tree->map);
                        free_extent_map(merge);
                }
@@ -227,7 +233,6 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
                merge->in_tree = 0;
                em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
                em->generation = max(em->generation, merge->generation);
-               list_del_init(&merge->list);
                free_extent_map(merge);
        }
 }
@@ -302,7 +307,7 @@ void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
  * reference dropped if the merge attempt was successful.
  */
 int add_extent_mapping(struct extent_map_tree *tree,
-                      struct extent_map *em)
+                      struct extent_map *em, int modified)
 {
        int ret = 0;
        struct rb_node *rb;
@@ -324,7 +329,10 @@ int add_extent_mapping(struct extent_map_tree *tree,
        em->mod_start = em->start;
        em->mod_len = em->len;
 
-       try_merge_map(tree, em);
+       if (modified)
+               list_move(&em->list, &tree->modified_extents);
+       else
+               try_merge_map(tree, em);
 out:
        return ret;
 }
@@ -337,8 +345,9 @@ static u64 range_end(u64 start, u64 len)
        return start + len;
 }
 
-struct extent_map *__lookup_extent_mapping(struct extent_map_tree *tree,
-                                          u64 start, u64 len, int strict)
+static struct extent_map *
+__lookup_extent_mapping(struct extent_map_tree *tree,
+                       u64 start, u64 len, int strict)
 {
        struct extent_map *em;
        struct rb_node *rb_node;