Commit 04734e84 authored by Josef Bacik's avatar Josef Bacik Committed by David Sterba
Browse files

btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_info 



We look up whatever root userspace has given us, we need to hold a ref
throughout this operation. Use 'root' only for the on fs root and not as
a temporary variable elsewhere.

Signed-off-by: default avatarJosef Bacik <josef@toxicpanda.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent b8a49ae1

fs/btrfs/ioctl.c

+8 −4
Original line number Diff line number Diff line
@@ -2681,6 +2681,10 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp) 
	root = btrfs_get_fs_root(fs_info, &key, true);

	if (IS_ERR(root)) {

		ret = PTR_ERR(root);

		goto out_free;

	}

	if (!btrfs_grab_fs_root(root)) {

		ret = -ENOENT;

		goto out;

	}

	root_item = &root->root_item;
@@ -2714,16 +2718,14 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp) 


	if (key.objectid != BTRFS_FS_TREE_OBJECTID) {

		/* Search root tree for ROOT_BACKREF of this subvolume */

		root = fs_info->tree_root;



		key.type = BTRFS_ROOT_BACKREF_KEY;

		key.offset = 0;

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);

		ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);

		if (ret < 0) {

			goto out;

		} else if (path->slots[0] >=

			   btrfs_header_nritems(path->nodes[0])) {

			ret = btrfs_next_leaf(root, path);

			ret = btrfs_next_leaf(fs_info->tree_root, path);

			if (ret < 0) {

				goto out;

			} else if (ret > 0) {
@@ -2758,6 +2760,8 @@ static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp) 
		ret = -EFAULT;



out:

	btrfs_put_fs_root(root);

out_free:

	btrfs_free_path(path);

	kzfree(subvol_info);

	return ret;