1 files changed, 60 insertions, 13 deletions

diff --git a/extent_io.c b/extent_io.c
index 1c6c1425..eda1fb6f 100644
--- a/extent_io.c
+++ b/extent_io.c
@@ -22,11 +22,13 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <stdbool.h>
 #include "kerncompat.h"
 #include "extent_io.h"
 #include "list.h"
 #include "ctree.h"
 #include "volumes.h"
+#include "utils.h"
 #include "internal.h"
 
 void extent_io_tree_init(struct extent_io_tree *tree)
@@ -35,6 +37,14 @@ void extent_io_tree_init(struct extent_io_tree *tree)
 	cache_tree_init(&tree->cache);
 	INIT_LIST_HEAD(&tree->lru);
 	tree->cache_size = 0;
+	tree->max_cache_size = (u64)total_memory() / 4;
+}
+
+void extent_io_tree_init_cache_max(struct extent_io_tree *tree,
+				   u64 max_cache_size)
+{
+	extent_io_tree_init(tree);
+	tree->max_cache_size = max_cache_size;
 }
 
 static struct extent_state *alloc_extent_state(void)
@@ -67,16 +77,21 @@ static void free_extent_state_func(struct cache_extent *cache)
 	btrfs_free_extent_state(es);
 }
 
+static void free_extent_buffer_final(struct extent_buffer *eb);
 void extent_io_tree_cleanup(struct extent_io_tree *tree)
 {
 	struct extent_buffer *eb;
 
 	while(!list_empty(&tree->lru)) {
 		eb = list_entry(tree->lru.next, struct extent_buffer, lru);
-		fprintf(stderr, "extent buffer leak: "
-			"start %llu len %u\n",
-			(unsigned long long)eb->start, eb->len);
-		free_extent_buffer(eb);
+		if (eb->refs) {
+			fprintf(stderr,
+				"extent buffer leak: start %llu len %u\n",
+				(unsigned long long)eb->start, eb->len);
+			free_extent_buffer_nocache(eb);
+		} else {
+			free_extent_buffer_final(eb);
+		}
 	}
 
 	cache_tree_free_extents(&tree->state, free_extent_state_func);
@@ -567,7 +582,21 @@ struct extent_buffer *btrfs_clone_extent_buffer(struct extent_buffer *src)
 	return new;
 }
 
-void free_extent_buffer(struct extent_buffer *eb)
+static void free_extent_buffer_final(struct extent_buffer *eb)
+{
+	struct extent_io_tree *tree = eb->tree;
+
+	BUG_ON(eb->refs);
+	BUG_ON(tree->cache_size < eb->len);
+	list_del_init(&eb->lru);
+	if (!(eb->flags & EXTENT_BUFFER_DUMMY)) {
+		remove_cache_extent(&tree->cache, &eb->cache_node);
+		tree->cache_size -= eb->len;
+	}
+	free(eb);
+}
+
+static void free_extent_buffer_internal(struct extent_buffer *eb, bool free_now)
 {
 	if (!eb || IS_ERR(eb))
 		return;
@@ -575,19 +604,23 @@ void free_extent_buffer(struct extent_buffer *eb)
 	eb->refs--;
 	BUG_ON(eb->refs < 0);
 	if (eb->refs == 0) {
-		struct extent_io_tree *tree = eb->tree;
 		BUG_ON(eb->flags & EXTENT_DIRTY);
-		list_del_init(&eb->lru);
 		list_del_init(&eb->recow);
-		if (!(eb->flags & EXTENT_BUFFER_DUMMY)) {
-			BUG_ON(tree->cache_size < eb->len);
-			remove_cache_extent(&tree->cache, &eb->cache_node);
-			tree->cache_size -= eb->len;
-		}
-		free(eb);
+		if (eb->flags & EXTENT_BUFFER_DUMMY || free_now)
+			free_extent_buffer_final(eb);
 	}
 }
 
+void free_extent_buffer(struct extent_buffer *eb)
+{
+	free_extent_buffer_internal(eb, 0);
+}
+
+void free_extent_buffer_nocache(struct extent_buffer *eb)
+{
+	free_extent_buffer_internal(eb, 1);
+}
+
 struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree,
 					 u64 bytenr, u32 blocksize)
 {
@@ -619,6 +652,18 @@ struct extent_buffer *find_first_extent_buffer(struct extent_io_tree *tree,
 	return eb;
 }
 
+static void trim_extent_buffer_cache(struct extent_io_tree *tree)
+{
+	struct extent_buffer *eb, *tmp;
+
+	list_for_each_entry_safe(eb, tmp, &tree->lru, lru) {
+		if (eb->refs == 0)
+			free_extent_buffer_final(eb);
+		if (tree->cache_size <= ((tree->max_cache_size * 9) / 10))
+			break;
+	}
+}
+
 struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 					  u64 bytenr, u32 blocksize)
 {
@@ -649,6 +694,8 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree,
 		}
 		list_add_tail(&eb->lru, &tree->lru);
 		tree->cache_size += blocksize;
+		if (tree->cache_size >= tree->max_cache_size)
+			trim_extent_buffer_cache(tree);
 	}
 	return eb;
 }