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-rw-r--r--fs/btrfs/ref-cache.c164
1 files changed, 0 insertions, 164 deletions
diff --git a/fs/btrfs/ref-cache.c b/fs/btrfs/ref-cache.c
index a97314cf6bd6..82d569cb6267 100644
--- a/fs/btrfs/ref-cache.c
+++ b/fs/btrfs/ref-cache.c
@@ -23,56 +23,6 @@
#include "ref-cache.h"
#include "transaction.h"
-/*
- * leaf refs are used to cache the information about which extents
- * a given leaf has references on. This allows us to process that leaf
- * in btrfs_drop_snapshot without needing to read it back from disk.
- */
-
-/*
- * kmalloc a leaf reference struct and update the counters for the
- * total ref cache size
- */
-struct btrfs_leaf_ref *btrfs_alloc_leaf_ref(struct btrfs_root *root,
- int nr_extents)
-{
- struct btrfs_leaf_ref *ref;
- size_t size = btrfs_leaf_ref_size(nr_extents);
-
- ref = kmalloc(size, GFP_NOFS);
- if (ref) {
- spin_lock(&root->fs_info->ref_cache_lock);
- root->fs_info->total_ref_cache_size += size;
- spin_unlock(&root->fs_info->ref_cache_lock);
-
- memset(ref, 0, sizeof(*ref));
- atomic_set(&ref->usage, 1);
- INIT_LIST_HEAD(&ref->list);
- }
- return ref;
-}
-
-/*
- * free a leaf reference struct and update the counters for the
- * total ref cache size
- */
-void btrfs_free_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
-{
- if (!ref)
- return;
- WARN_ON(atomic_read(&ref->usage) == 0);
- if (atomic_dec_and_test(&ref->usage)) {
- size_t size = btrfs_leaf_ref_size(ref->nritems);
-
- BUG_ON(ref->in_tree);
- kfree(ref);
-
- spin_lock(&root->fs_info->ref_cache_lock);
- root->fs_info->total_ref_cache_size -= size;
- spin_unlock(&root->fs_info->ref_cache_lock);
- }
-}
-
static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
struct rb_node *node)
{
@@ -116,117 +66,3 @@ static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
}
return NULL;
}
-
-int btrfs_remove_leaf_refs(struct btrfs_root *root, u64 max_root_gen,
- int shared)
-{
- struct btrfs_leaf_ref *ref = NULL;
- struct btrfs_leaf_ref_tree *tree = root->ref_tree;
-
- if (shared)
- tree = &root->fs_info->shared_ref_tree;
- if (!tree)
- return 0;
-
- spin_lock(&tree->lock);
- while (!list_empty(&tree->list)) {
- ref = list_entry(tree->list.next, struct btrfs_leaf_ref, list);
- BUG_ON(ref->tree != tree);
- if (ref->root_gen > max_root_gen)
- break;
- if (!xchg(&ref->in_tree, 0)) {
- cond_resched_lock(&tree->lock);
- continue;
- }
-
- rb_erase(&ref->rb_node, &tree->root);
- list_del_init(&ref->list);
-
- spin_unlock(&tree->lock);
- btrfs_free_leaf_ref(root, ref);
- cond_resched();
- spin_lock(&tree->lock);
- }
- spin_unlock(&tree->lock);
- return 0;
-}
-
-/*
- * find the leaf ref for a given extent. This returns the ref struct with
- * a usage reference incremented
- */
-struct btrfs_leaf_ref *btrfs_lookup_leaf_ref(struct btrfs_root *root,
- u64 bytenr)
-{
- struct rb_node *rb;
- struct btrfs_leaf_ref *ref = NULL;
- struct btrfs_leaf_ref_tree *tree = root->ref_tree;
-again:
- if (tree) {
- spin_lock(&tree->lock);
- rb = tree_search(&tree->root, bytenr);
- if (rb)
- ref = rb_entry(rb, struct btrfs_leaf_ref, rb_node);
- if (ref)
- atomic_inc(&ref->usage);
- spin_unlock(&tree->lock);
- if (ref)
- return ref;
- }
- if (tree != &root->fs_info->shared_ref_tree) {
- tree = &root->fs_info->shared_ref_tree;
- goto again;
- }
- return NULL;
-}
-
-/*
- * add a fully filled in leaf ref struct
- * remove all the refs older than a given root generation
- */
-int btrfs_add_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref,
- int shared)
-{
- int ret = 0;
- struct rb_node *rb;
- struct btrfs_leaf_ref_tree *tree = root->ref_tree;
-
- if (shared)
- tree = &root->fs_info->shared_ref_tree;
-
- spin_lock(&tree->lock);
- rb = tree_insert(&tree->root, ref->bytenr, &ref->rb_node);
- if (rb) {
- ret = -EEXIST;
- } else {
- atomic_inc(&ref->usage);
- ref->tree = tree;
- ref->in_tree = 1;
- list_add_tail(&ref->list, &tree->list);
- }
- spin_unlock(&tree->lock);
- return ret;
-}
-
-/*
- * remove a single leaf ref from the tree. This drops the ref held by the tree
- * only
- */
-int btrfs_remove_leaf_ref(struct btrfs_root *root, struct btrfs_leaf_ref *ref)
-{
- struct btrfs_leaf_ref_tree *tree;
-
- if (!xchg(&ref->in_tree, 0))
- return 0;
-
- tree = ref->tree;
- spin_lock(&tree->lock);
-
- rb_erase(&ref->rb_node, &tree->root);
- list_del_init(&ref->list);
-
- spin_unlock(&tree->lock);
-
- btrfs_free_leaf_ref(root, ref);
- return 0;
-}