Btrfs: add snapshot/subvolume destroy ioctl
This patch adds snapshot/subvolume destroy ioctl. A subvolume that isn't being
used and doesn't contains links to other subvolumes can be destroyed.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 5ef7259..9351428 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -94,17 +94,23 @@
goto out;
BUG_ON(ret == 0);
- 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 (path->slots[0] == 0) {
ret = 1;
goto out;
}
- read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
- sizeof(*item));
- memcpy(key, &found_key, sizeof(found_key));
+ l = path->nodes[0];
+ slot = path->slots[0] - 1;
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ if (found_key.objectid != objectid ||
+ found_key.type != BTRFS_ROOT_ITEM_KEY) {
+ ret = 1;
+ goto out;
+ }
+ 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 @@
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)