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path: root/fs/btrfs/extent_map.c
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Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c72
1 files changed, 41 insertions, 31 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index a4a7a1a8da95..b60955d4f9bf 100644
--- 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;
}
/*
@@ -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)