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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.c155
1 files changed, 50 insertions, 105 deletions
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 2d04103..7c97b33 100644
--- 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;
@@ -320,38 +292,42 @@ 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
@@ -365,38 +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);
}
/**