X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fextent_map.c;h=28d87ba60ce8170d0c10d14225dc5ce37eb24beb;hb=861248d177145fc5861507e4607fec89fd0a0462;hp=b187917b36fa8c19202b1e5049f3bbf9aaef451f;hpb=ff0a5836ac48554b9f3b9d3c5f5bce4ddea11f1f;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index b187917..28d87ba 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -6,19 +6,14 @@
 #include <linux/hardirq.h>
 #include "extent_map.h"
 
-/* temporary define until extent_map moves out of btrfs */
-struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
-				       unsigned long extra_flags,
-				       void (*ctor)(void *, struct kmem_cache *,
-						    unsigned long));
 
 static struct kmem_cache *extent_map_cache;
 
 int __init extent_map_init(void)
 {
-	extent_map_cache = btrfs_cache_create("extent_map",
-					    sizeof(struct extent_map), 0,
-					    NULL);
+	extent_map_cache = kmem_cache_create("extent_map",
+			sizeof(struct extent_map), 0,
+			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
 	if (!extent_map_cache)
 		return -ENOMEM;
 	return 0;
@@ -40,10 +35,9 @@ void extent_map_exit(void)
  */
 void extent_map_tree_init(struct extent_map_tree *tree, gfp_t mask)
 {
-	tree->map.rb_node = NULL;
-	spin_lock_init(&tree->lock);
+	tree->map = RB_ROOT;
+	rwlock_init(&tree->lock);
 }
-EXPORT_SYMBOL(extent_map_tree_init);
 
 /**
  * alloc_extent_map - allocate new extent map structure
@@ -64,7 +58,6 @@ struct extent_map *alloc_extent_map(gfp_t mask)
 	atomic_set(&em->refs, 1);
 	return em;
 }
-EXPORT_SYMBOL(alloc_extent_map);
 
 /**
  * free_extent_map - drop reference count of an extent_map
@@ -83,7 +76,6 @@ void free_extent_map(struct extent_map *em)
 		kmem_cache_free(extent_map_cache, em);
 	}
 }
-EXPORT_SYMBOL(free_extent_map);
 
 static struct rb_node *tree_insert(struct rb_root *root, u64 offset,
 				   struct rb_node *node)
@@ -163,20 +155,6 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
 	return NULL;
 }
 
-/*
- * look for an offset in the tree, and if it can't be found, return
- * the first offset we can find smaller than 'offset'.
- */
-static inline struct rb_node *tree_search(struct rb_root *root, u64 offset)
-{
-	struct rb_node *prev;
-	struct rb_node *ret;
-	ret = __tree_search(root, offset, &prev, NULL);
-	if (!ret)
-		return prev;
-	return ret;
-}
-
 /* check to see if two extent_map structs are adjacent and safe to merge */
 static int mergable_maps(struct extent_map *prev, struct extent_map *next)
 {
@@ -206,6 +184,56 @@ 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)
+{
+	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);
+		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);
+	}
+
+	free_extent_map(em);
+out:
+	write_unlock(&tree->lock);
+	return ret;
+
+}
+
 /**
  * add_extent_mapping - add new extent map to the extent tree
  * @tree:	tree to insert new map in
@@ -214,7 +242,7 @@ static int mergable_maps(struct extent_map *prev, struct extent_map *next)
  * Insert @em into @tree or perform a simple forward/backward merge with
  * existing mappings.  The extent_map struct passed in will be inserted
  * into the tree directly, with an additional reference taken, or a
- * reference dropped if the merge attempt was sucessfull.
+ * reference dropped if the merge attempt was successfull.
  */
 int add_extent_mapping(struct extent_map_tree *tree,
 		       struct extent_map *em)
@@ -230,7 +258,6 @@ int add_extent_mapping(struct extent_map_tree *tree,
 		ret = -EEXIST;
 		goto out;
 	}
-	assert_spin_locked(&tree->lock);
 	rb = tree_insert(&tree->map, em->start, &em->rb_node);
 	if (rb) {
 		ret = -EEXIST;
@@ -264,7 +291,6 @@ int add_extent_mapping(struct extent_map_tree *tree,
 out:
 	return ret;
 }
-EXPORT_SYMBOL(add_extent_mapping);
 
 /* simple helper to do math around the end of an extent, handling wrap */
 static u64 range_end(u64 start, u64 len)
@@ -294,7 +320,6 @@ struct extent_map *lookup_extent_mapping(struct extent_map_tree *tree,
 	struct rb_node *next = NULL;
 	u64 end = range_end(start, len);
 
-	assert_spin_locked(&tree->lock);
 	rb_node = __tree_search(&tree->map, start, &prev, &next);
 	if (!rb_node && prev) {
 		em = rb_entry(prev, struct extent_map, rb_node);
@@ -326,7 +351,54 @@ found:
 out:
 	return em;
 }
-EXPORT_SYMBOL(lookup_extent_mapping);
+
+/**
+ * search_extent_mapping - find a nearby 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.
+ *
+ * If one can't be found, any nearby extent may be returned
+ */
+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_PTR(PTR_ERR(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;
+}
 
 /**
  * remove_extent_mapping - removes an extent_map from the extent tree
@@ -341,9 +413,7 @@ int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
 	int ret = 0;
 
 	WARN_ON(test_bit(EXTENT_FLAG_PINNED, &em->flags));
-	assert_spin_locked(&tree->lock);
 	rb_erase(&em->rb_node, &tree->map);
 	em->in_tree = 0;
 	return ret;
 }
-EXPORT_SYMBOL(remove_extent_mapping);