diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 27 |
1 files changed, 8 insertions, 19 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 73e53009e126..8680110f0a5a 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -147,10 +147,11 @@ noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) struct extent_buffer *btrfs_root_node(struct btrfs_root *root) { struct extent_buffer *eb; - spin_lock(&root->node_lock); - eb = root->node; + + rcu_read_lock(); + eb = rcu_dereference(root->node); extent_buffer_get(eb); - spin_unlock(&root->node_lock); + rcu_read_unlock(); return eb; } @@ -165,14 +166,8 @@ struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) while (1) { eb = btrfs_root_node(root); btrfs_tree_lock(eb); - - spin_lock(&root->node_lock); - if (eb == root->node) { - spin_unlock(&root->node_lock); + if (eb == root->node) break; - } - spin_unlock(&root->node_lock); - btrfs_tree_unlock(eb); free_extent_buffer(eb); } @@ -458,10 +453,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, else parent_start = 0; - spin_lock(&root->node_lock); - root->node = cow; extent_buffer_get(cow); - spin_unlock(&root->node_lock); + rcu_assign_pointer(root->node, cow); btrfs_free_tree_block(trans, root, buf, parent_start, last_ref); @@ -930,9 +923,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, goto enospc; } - spin_lock(&root->node_lock); - root->node = child; - spin_unlock(&root->node_lock); + rcu_assign_pointer(root->node, child); add_root_to_dirty_list(root); btrfs_tree_unlock(child); @@ -2007,10 +1998,8 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(c); - spin_lock(&root->node_lock); old = root->node; - root->node = c; - spin_unlock(&root->node_lock); + rcu_assign_pointer(root->node, c); /* the super has an extra ref to root->node */ free_extent_buffer(old); |