linux-kernel - Re: [PATCH v3 1/4] fs/posix_acl: apply umask if superblock disables ACL support

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Date:   Fri, 17 Apr 2020 00:35:11 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Max Kellermann <mk@...all.com>
Cc:     linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org,
        trond.myklebust@...merspace.com, bfields@...hat.com, tytso@....edu,
        viro@...iv.linux.org.uk, agruenba@...hat.com,
        linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH v3 1/4] fs/posix_acl: apply umask if superblock disables
 ACL support

On Tue, Apr 07, 2020 at 04:22:40PM +0200, Max Kellermann wrote:
>  
> -	if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
> +	if (S_ISLNK(*mode))
>  		return 0;
>  
> +	if (!IS_POSIXACL(dir)) {
> +		*mode &= ~current_umask();
> +		return 0;
> +	}
> +

I think the first hunk is obviously correct, but I don't think we need
the second one, as the handling of the get_acl() eturn value should do
the right thing.  If you want to optimize it a bit, it might be worth to
move the !IS_POSIXACL check in get_acl to the top of the function,
before checking the cached ACL.