Merge tag 'dm-3.14-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device...

[~andy/linux] / fs / btrfs / extent_map.c

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index a4a7a1a8da95c4c1e7571d99e0d58a7b5209f4ee..996ad56b57db64bbc0516f4674d8ad3fd2d43976 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -79,12 +79,21 @@ void free_extent_map(struct extent_map *em)
        }
 }
 
-static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
-                                  struct rb_node *node)
+/* simple helper to do math around the end of an extent, handling wrap */
+static u64 range_end(u64 start, u64 len)
+{
+       if (start + len < start)
+               return (u64)-1;
+       return start + len;
+}
+
+static int tree_insert(struct rb_root *root, struct extent_map *em)
 {
        struct rb_node **p = &root->rb_node;
        struct rb_node *parent = NULL;
-       struct extent_map *entry;
+       struct extent_map *entry = NULL;
+       struct rb_node *orig_parent = NULL;
+       u64 end = range_end(em->start, em->len);
 
        while (*p) {
                parent = *p;
@@ -92,19 +101,37 @@ static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
 
                WARN_ON(!entry->in_tree);
 
-               if (offset < entry->start)
+               if (em->start < entry->start)
                        p = &(*p)->rb_left;
-               else if (offset >= extent_map_end(entry))
+               else if (em->start >= extent_map_end(entry))
                        p = &(*p)->rb_right;
                else
-                       return parent;
+                       return -EEXIST;
        }
 
-       entry = rb_entry(node, struct extent_map, rb_node);
-       entry->in_tree = 1;
-       rb_link_node(node, parent, p);
-       rb_insert_color(node, root);
-       return NULL;
+       orig_parent = parent;
+       while (parent && em->start >= extent_map_end(entry)) {
+               parent = rb_next(parent);
+               entry = rb_entry(parent, struct extent_map, rb_node);
+       }
+       if (parent)
+               if (end > entry->start && em->start < extent_map_end(entry))
+                       return -EEXIST;
+
+       parent = orig_parent;
+       entry = rb_entry(parent, struct extent_map, rb_node);
+       while (parent && em->start < entry->start) {
+               parent = rb_prev(parent);
+               entry = rb_entry(parent, struct extent_map, rb_node);
+       }
+       if (parent)
+               if (end > entry->start && em->start < extent_map_end(entry))
+                       return -EEXIST;
+
+       em->in_tree = 1;
+       rb_link_node(&em->rb_node, orig_parent, p);
+       rb_insert_color(&em->rb_node, root);
+       return 0;
 }
 
 /*
@@ -228,7 +255,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
                merge = rb_entry(rb, struct extent_map, rb_node);
        if (rb && mergable_maps(em, merge)) {
                em->len += merge->len;
-               em->block_len += merge->len;
+               em->block_len += merge->block_len;
                rb_erase(&merge->rb_node, &tree->map);
                merge->in_tree = 0;
                em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
@@ -310,20 +337,11 @@ int add_extent_mapping(struct extent_map_tree *tree,
                       struct extent_map *em, int modified)
 {
        int ret = 0;
-       struct rb_node *rb;
-       struct extent_map *exist;
 
-       exist = lookup_extent_mapping(tree, em->start, em->len);
-       if (exist) {
-               free_extent_map(exist);
-               ret = -EEXIST;
-               goto out;
-       }
-       rb = tree_insert(&tree->map, em->start, &em->rb_node);
-       if (rb) {
-               ret = -EEXIST;
+       ret = tree_insert(&tree->map, em);
+       if (ret)
                goto out;
-       }
+
        atomic_inc(&em->refs);
 
        em->mod_start = em->start;
@@ -337,14 +355,6 @@ out:
        return ret;
 }
 
-/* simple helper to do math around the end of an extent, handling wrap */
-static u64 range_end(u64 start, u64 len)
-{
-       if (start + len < start)
-               return (u64)-1;
-       return start + len;
-}
-
 static struct extent_map *
 __lookup_extent_mapping(struct extent_map_tree *tree,
                        u64 start, u64 len, int strict)