Merge branch 'slab/urgent' into slab/next

[pandora-kernel.git] / fs / btrfs / extent_map.c

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 2d04103..7c97b33 100644 (file)
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -183,22 +183,10 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next)
        return 0;
 }
 
-int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len)
+static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
 {
-       int ret = 0;
        struct extent_map *merge = NULL;
        struct rb_node *rb;
-       struct extent_map *em;
-
-       write_lock(&tree->lock);
-       em = lookup_extent_mapping(tree, start, len);
-
-       WARN_ON(!em || em->start != start);
-
-       if (!em)
-               goto out;
-
-       clear_bit(EXTENT_FLAG_PINNED, &em->flags);
 
        if (em->start != 0) {
                rb = rb_prev(&em->rb_node);
@@ -225,6 +213,24 @@ int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len)
                merge->in_tree = 0;
                free_extent_map(merge);
        }
+}
+
+int unpin_extent_cache(struct extent_map_tree *tree, u64 start, u64 len)
+{
+       int ret = 0;
+       struct extent_map *em;
+
+       write_lock(&tree->lock);
+       em = lookup_extent_mapping(tree, start, len);
+
+       WARN_ON(!em || em->start != start);
+
+       if (!em)
+               goto out;
+
+       clear_bit(EXTENT_FLAG_PINNED, &em->flags);
+
+       try_merge_map(tree, em);
 
        free_extent_map(em);
 out:
@@ -247,7 +253,6 @@ int add_extent_mapping(struct extent_map_tree *tree,
                       struct extent_map *em)
 {
        int ret = 0;
-       struct extent_map *merge = NULL;
        struct rb_node *rb;
        struct extent_map *exist;
 
@@ -263,30 +268,8 @@ int add_extent_mapping(struct extent_map_tree *tree,
                goto out;
        }
        atomic_inc(&em->refs);
-       if (em->start != 0) {
-               rb = rb_prev(&em->rb_node);
-               if (rb)
-                       merge = rb_entry(rb, struct extent_map, rb_node);
-               if (rb && mergable_maps(merge, em)) {
-                       em->start = merge->start;
-                       em->len += merge->len;
-                       em->block_len += merge->block_len;
-                       em->block_start = merge->block_start;
-                       merge->in_tree = 0;
-                       rb_erase(&merge->rb_node, &tree->map);
-                       free_extent_map(merge);
-               }
-        }
-       rb = rb_next(&em->rb_node);
-       if (rb)
-               merge = rb_entry(rb, struct extent_map, rb_node);
-       if (rb && mergable_maps(em, merge)) {
-               em->len += merge->len;
-               em->block_len += merge->len;
-               rb_erase(&merge->rb_node, &tree->map);
-               merge->in_tree = 0;
-               free_extent_map(merge);
-       }
+
+       try_merge_map(tree, em);
 out:
        return ret;
 }
@@ -299,19 +282,8 @@ static u64 range_end(u64 start, u64 len)
        return start + len;
 }
 
-/**
- * lookup_extent_mapping - lookup extent_map
- * @tree:      tree to lookup in
- * @start:     byte offset to start the search
- * @len:       length of the lookup range
- *
- * Find and return the first extent_map struct in @tree that intersects the
- * [start, len] range.  There may be additional objects in the tree that
- * intersect, so check the object returned carefully to make sure that no
- * additional lookups are needed.
- */
-struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
-                                        u64 start, u64 len)
+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;
@@ -320,37 +292,41 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
        u64 end = range_end(start, len);
 
        rb_node = __tree_search(&tree->map, start, &prev, &next);
-       if (!rb_node && prev) {
-               em = rb_entry(prev, struct extent_map, rb_node);
-               if (end > em->start && start < extent_map_end(em))
-                       goto found;
-       }
-       if (!rb_node && next) {
-               em = rb_entry(next, struct extent_map, rb_node);
-               if (end > em->start && start < extent_map_end(em))
-                       goto found;
-       }
        if (!rb_node) {
-               em = NULL;
-               goto out;
-       }
-       if (IS_ERR(rb_node)) {
-               em = ERR_CAST(rb_node);
-               goto out;
+               if (prev)
+                       rb_node = prev;
+               else if (next)
+                       rb_node = next;
+               else
+                       return NULL;
        }
+
        em = rb_entry(rb_node, struct extent_map, rb_node);
-       if (end > em->start && start < extent_map_end(em))
-               goto found;
 
-       em = NULL;
-       goto out;
+       if (strict && !(end > em->start && start < extent_map_end(em)))
+               return NULL;
 
-found:
        atomic_inc(&em->refs);
-out:
        return em;
 }
 
+/**
+ * lookup_extent_mapping - lookup extent_map
+ * @tree:      tree to lookup in
+ * @start:     byte offset to start the search
+ * @len:       length of the lookup range
+ *
+ * Find and return the first extent_map struct in @tree that intersects the
+ * [start, len] range.  There may be additional objects in the tree that
+ * intersect, so check the object returned carefully to make sure that no
+ * additional lookups are needed.
+ */
+struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
+                                        u64 start, u64 len)
+{
+       return __lookup_extent_mapping(tree, start, len, 1);
+}
+
 /**
  * search_extent_mapping - find a nearby extent map
  * @tree:      tree to lookup in
@@ -365,38 +341,7 @@ out:
 struct extent_map *search_extent_mapping(struct extent_map_tree *tree,
                                         u64 start, u64 len)
 {
-       struct extent_map *em;
-       struct rb_node *rb_node;
-       struct rb_node *prev = NULL;
-       struct rb_node *next = NULL;
-
-       rb_node = __tree_search(&tree->map, start, &prev, &next);
-       if (!rb_node && prev) {
-               em = rb_entry(prev, struct extent_map, rb_node);
-               goto found;
-       }
-       if (!rb_node && next) {
-               em = rb_entry(next, struct extent_map, rb_node);
-               goto found;
-       }
-       if (!rb_node) {
-               em = NULL;
-               goto out;
-       }
-       if (IS_ERR(rb_node)) {
-               em = ERR_CAST(rb_node);
-               goto out;
-       }
-       em = rb_entry(rb_node, struct extent_map, rb_node);
-       goto found;
-
-       em = NULL;
-       goto out;
-
-found:
-       atomic_inc(&em->refs);
-out:
-       return em;
+       return __lookup_extent_mapping(tree, start, len, 0);
 }
 
 /**