aboutsummaryrefslogtreecommitdiffstats
path: root/fs/btrfs/extent_map.c
diff options
context:
space:
mode:
authorLi Zefan <lizf@cn.fujitsu.com>2011-07-14 03:18:15 +0000
committerChris Mason <chris.mason@oracle.com>2011-08-01 14:30:49 -0400
commited64f06652210b4a52fe0ea65ac43f9c6af1d988 (patch)
treea4e8c63e4732384e9c72edeb552dab3f50a1351d /fs/btrfs/extent_map.c
parent7e016a038e829c7d1271e1d57b8002860bbdf0db (diff)
Btrfs: clean up code for extent_map lookup
lookup_extent_map() and search_extent_map() can share most of code. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/extent_map.c')
-rw-r--r--fs/btrfs/extent_map.c85
1 files changed, 29 insertions, 56 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 911a9db801e..df7a803005f 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -299,19 +299,8 @@ 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;
@@ -320,38 +309,42 @@ 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
* @start: byte offset to start the search
@@ -365,27 +358,7 @@ 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)
- return NULL;
-
- em = rb_entry(rb_node, struct extent_map, rb_node);
-found:
- atomic_inc(&em->refs);
- return em;
+ return __lookup_extent_mapping(tree, start, len, 0);
}
/**