linux-kernel - Re: [PATCH v18 11/22] vfs: Cache base

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20160311140746.GC14808@infradead.org>
Date:	Fri, 11 Mar 2016 06:07:46 -0800
From:	Christoph Hellwig <hch@...radead.org>
To:	Andreas Gruenbacher <agruenba@...hat.com>
Cc:	Alexander Viro <viro@...iv.linux.org.uk>,
	"J. Bruce Fields" <bfields@...ldses.org>,
	linux-nfs@...r.kernel.org, Theodore Ts'o <tytso@....edu>,
	linux-cifs@...r.kernel.org, linux-api@...r.kernel.org,
	Trond Myklebust <trond.myklebust@...marydata.com>,
	linux-kernel@...r.kernel.org, xfs@....sgi.com,
	Christoph Hellwig <hch@...radead.org>,
	Andreas Dilger <adilger.kernel@...ger.ca>,
	linux-fsdevel@...r.kernel.org,
	Jeff Layton <jlayton@...chiereds.net>,
	linux-ext4@...r.kernel.org,
	Anna Schumaker <anna.schumaker@...app.com>, jaegeuk@...nel.org,
	chao2.yu@...sung.com
Subject: Re: [PATCH v18 11/22] vfs: Cache base_acl objects in inodes

On Mon, Feb 29, 2016 at 09:17:16AM +0100, Andreas Gruenbacher wrote:
> POSIX ACLs and richacls are both objects allocated by kmalloc() with a
> reference count which are freed by kfree_rcu().  An inode can either
> cache an access and a default POSIX ACL, or a richacl (richacls do not
> have default acls).  To allow an inode to cache either of the two kinds
> of acls, introduce a new base_acl type and convert i_acl and
> i_default_acl to that type. In most cases, the vfs then doesn't care which
> kind of acl an inode caches (if any).

This base_acl object is pointless.  I've asked in the past to have
a proper container for the ACLs in common code, but a union
of a refcount and a rcu head doesn't really fit that category.

But this points out that the f2fs folks really need a couple of
slaps on their hands.  Not if generic funtionality doesn't
fit your needs you are not going to blindly copy and paste it,
please talk to find a solution instead of duplicating it.

Folks, please come up with a suggestion to get rid of f2fs_acl_clone,
f2fs_acl_create_masq and f2fs_acl_create ASAP.