[PATCH 12/18] ocfs2: use generic posix ACL infrastructure

[Christoph Hellwig]

On Tue, Dec 03, 2013 at 12:00:07AM +0100, Jan Kara wrote:
>   Hum, this changes the cluster locking. Previously ocfs2_acl_get() used
> from ocfs2_acl_chmod() grabbed cluster wide inode lock. Now getting of ACL
> isn't protected by the inode lock. That being said the cluster locking
> around setattr looks fishy anyway - if two processes on different
> nodes are changing attributes of the same file, changing ACLs post fact
> after dropping inode lock could cause interesting effects. Also I'm
> wondering how inode_change_ok() can ever be safe without holding inode
> lock... Until we grab that other node is free to change e.g. owner of the
> inode thus leading even to security implications. But maybe I'm missing
> something. Mark, Joel?

Hmm, indeed.  How does ocfs2_iop_get_acl get away without that lock?

Btw, ocfs2 changes will need careful testing as I couldn't find any easy
way to run xfstests on ocfs2 out of the box.