From: Jeff Mahoney <jeffm@suse.com>

The following is a patch to fix a locking problem in ACL/xattr code. It
manifests when a user attempts to set an xattr on a file which they do
not own, and on which an ACL is applied.

What happens is this:
reiserfs_setxattr [write lock inode xattr sem]
  ->xattr_set
    -> lookup
       -> __reiserfs_permission [if conditions above are met, and need_lock=
 is
          unset, read lock inode xattr sem] *lockup*

Since we already keep track of when to lock during permission calls, the
fix is simple: just make the locking conditional as it was before.

Credits to Andreas Gruenbacher <agruen@suse.de>