From: Steven Whitehouse <swhiteho@redhat.com>
Date: Fri, 14 Jun 2013 10:17:15 +0000 (+0100)
Subject: GFS2: Add atomic_open support
X-Git-Tag: omap-for-v3.11/fixes-for-merge-window~82^2~5
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6d4ade986f9c8df31e68fd30643997f79cc5a5f8;p=pandora-kernel.git

GFS2: Add atomic_open support

I've restricted atomic_open to only operate on regular files, although
I still don't understand why atomic_open should not be possible also for
directories on GFS2. That can always be added in later though, if it
makes sense.

The ->atomic_open function can be passed negative dentries, which
in most cases means either ENOENT (->lookup) or a call to d_instantiate
(->create). In the GFS2 case though, we need to actually perform the
look up, since we do not know whether there has been a new inode created
on another node. The look up calls d_splice_alias which then tries to
rehash the dentry - so the solution here is to simply check for that
in d_splice_alias. The same issue is likely to affect any other cluster
filesystem implementing ->atomic_open

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields fieldses org>
Cc: Jeff Layton <jlayton@redhat.com>
---

Reading git-diff-tree failed