Btrfs: add snapshot/subvolume destroy ioctl

[cascardo/linux.git] / fs / btrfs / root-tree.c

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 5ef7259..9351428 100644 (file)
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -94,17 +94,23 @@ int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
                goto out;
 
        BUG_ON(ret == 0);
+       if (path->slots[0] == 0) {
+               ret = 1;
+               goto out;
+       }
        l = path->nodes[0];
-       BUG_ON(path->slots[0] == 0);
        slot = path->slots[0] - 1;
        btrfs_item_key_to_cpu(l, &found_key, slot);
-       if (found_key.objectid != objectid) {
+       if (found_key.objectid != objectid ||
+           found_key.type != BTRFS_ROOT_ITEM_KEY) {
                ret = 1;
                goto out;
        }
-       read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
-                          sizeof(*item));
-       memcpy(key, &found_key, sizeof(found_key));
+       if (item)
+               read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
+                                  sizeof(*item));
+       if (key)
+               memcpy(key, &found_key, sizeof(found_key));
        ret = 0;
 out:
        btrfs_free_path(path);
@@ -249,6 +255,59 @@ err:
        return ret;
 }
 
+int btrfs_find_orphan_roots(struct btrfs_root *tree_root)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       int err = 0;
+       int ret;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       key.objectid = BTRFS_ORPHAN_OBJECTID;
+       key.type = BTRFS_ORPHAN_ITEM_KEY;
+       key.offset = 0;
+
+       while (1) {
+               ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+               if (ret < 0) {
+                       err = ret;
+                       break;
+               }
+
+               leaf = path->nodes[0];
+               if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+                       ret = btrfs_next_leaf(tree_root, path);
+                       if (ret < 0)
+                               err = ret;
+                       if (ret != 0)
+                               break;
+                       leaf = path->nodes[0];
+               }
+
+               btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+               btrfs_release_path(tree_root, path);
+
+               if (key.objectid != BTRFS_ORPHAN_OBJECTID ||
+                   key.type != BTRFS_ORPHAN_ITEM_KEY)
+                       break;
+
+               ret = btrfs_find_dead_roots(tree_root, key.offset);
+               if (ret) {
+                       err = ret;
+                       break;
+               }
+
+               key.offset++;
+       }
+
+       btrfs_free_path(path);
+       return err;
+}
+
 /* drop the root item for 'key' from 'root' */
 int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                   struct btrfs_key *key)