btrfs: hold a ref on the root in search_ioctl

We lookup a arbitrary fs root, we need to hold a ref on that root. If we're using our own inodes root then grab a ref on that as well to make the cleanup easier. Signed-off-by: Josef Bacik <[email protected]> Reviewed-by: David Sterba <[email protected]> Signed-off-by: David Sterba <[email protected]>
mrcsosa · Mar 23, 2020 · 3ca35e8 · 3ca35e8
1 parent fc92f79
commit 3ca35e8
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
@@ -2180,7 +2180,7 @@ static noinline int search_ioctl(struct inode *inode,
 
 	if (sk->tree_id == 0) {
 		/* search the root of the inode that was passed */
-		root = BTRFS_I(inode)->root;
+		root = btrfs_grab_fs_root(BTRFS_I(inode)->root);
 	} else {
 		key.objectid = sk->tree_id;
 		key.type = BTRFS_ROOT_ITEM_KEY;
@@ -2190,6 +2190,10 @@ static noinline int search_ioctl(struct inode *inode,
 			btrfs_free_path(path);
 			return PTR_ERR(root);
 		}
+		if (!btrfs_grab_fs_root(root)) {
+			btrfs_free_path(path);
+			return -ENOENT;
+		}
 	}
 
 	key.objectid = sk->min_objectid;
@@ -2214,6 +2218,7 @@ static noinline int search_ioctl(struct inode *inode,
 		ret = 0;
 err:
 	sk->nr_items = num_found;
+	btrfs_put_fs_root(root);
 	btrfs_free_path(path);
 	return ret;
 }