Re: [PATCH 4/6] fuse: return correct dentry for ->mkdir

[Al Viro <viro@zeniv.linux.org.uk>]

On Fri, Feb 21, 2025 at 10:36:33AM +1100, NeilBrown wrote:

> @@ -871,7 +870,12 @@ static int fuse_mknod(struct mnt_idmap *idmap, struct inode *dir,
>  	args.in_args[0].value = &inarg;
>  	args.in_args[1].size = entry->d_name.len + 1;
>  	args.in_args[1].value = entry->d_name.name;
> -	return create_new_entry(idmap, fm, &args, dir, entry, mode);
> +	de = create_new_entry(idmap, fm, &args, dir, entry, mode);
> +	if (IS_ERR(de))
> +		return PTR_ERR(de);
> +	if (de)
> +		dput(de);
> +	return 0;

Can that really happen?

> @@ -934,7 +939,12 @@ static int fuse_symlink(struct mnt_idmap *idmap, struct inode *dir,
>  	args.in_args[1].value = entry->d_name.name;
>  	args.in_args[2].size = len;
>  	args.in_args[2].value = link;
> -	return create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> +	de = create_new_entry(idmap, fm, &args, dir, entry, S_IFLNK);
> +	if (IS_ERR(de))
> +		return PTR_ERR(de);
> +	if (de)
> +		dput(de);
> +	return 0;

Same question.

> +	de = create_new_entry(&invalid_mnt_idmap, fm, &args, newdir, newent, inode->i_mode);
> +	if (!IS_ERR(de)) {
> +		if (de)
> +			dput(de);
> +		de = NULL;

Whoa...  Details, please.  What's going on here?