Re: [PATCH v3] btrfs: send: add support for fs-verity

[David Sterba <dsterba@suse.cz>]

On Mon, Aug 01, 2022 at 11:54:40AM -0700, Boris Burkov wrote:
> +static int process_new_verity(struct send_ctx *sctx)
> +{
> +	int ret = 0;
> +	struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> +	struct inode *inode;
> +	struct fs_path *p;
> +
> +	inode = btrfs_iget(fs_info->sb, sctx->cur_ino, sctx->send_root);
> +	if (IS_ERR(inode))
> +		return PTR_ERR(inode);
> +
> +	ret = fs_info->sb->s_vop->get_verity_descriptor(inode, NULL, 0);

This is a long way to call btrfs_get_verity_descriptor from
fs/btrfs/verity.c , is there a reason we can't call it directly?

> +	if (ret < 0)
> +		goto iput;
> +
> +	if (ret > FS_VERITY_MAX_DESCRIPTOR_SIZE) {
> +		ret = -EMSGSIZE;
> +		goto iput;
> +	}
> +	if (!sctx->verity_descriptor) {
> +		sctx->verity_descriptor = kvmalloc(FS_VERITY_MAX_DESCRIPTOR_SIZE, GFP_KERNEL);
> +		if (!sctx->verity_descriptor) {
> +			ret = -ENOMEM;
> +			goto iput;
> +		}
> +	}
> +
> +	ret = fs_info->sb->s_vop->get_verity_descriptor(inode, sctx->verity_descriptor, ret);
> +	if (ret < 0)
> +		goto iput;
> +
> +	p = fs_path_alloc();
> +	if (!p) {
> +		ret = -ENOMEM;
> +		goto iput;
> +	}
> +	ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p);
> +	if (ret < 0)
> +		goto free_path;
> +
> +	ret = send_verity(sctx, p, sctx->verity_descriptor);
> +	if (ret < 0)
> +		goto free_path;
> +
> +free_path:
> +	fs_path_free(p);
> +iput:
> +	iput(inode);
> +	return ret;
> +}