From: Steven Whitehouse <swhiteho@redhat.com>
Date: Thu, 17 Jan 2008 15:12:03 +0000 (+0000)
Subject: [GFS2] Fix page_mkwrite truncation race path
X-Git-Tag: v2.6.25-rc1~1241^2~2
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b7fe2e391ee7b711d6dfd6a694d60c4f21113cbb;p=linux-2.6

[GFS2] Fix page_mkwrite truncation race path

There was a bug in the truncation/invalidation race path for
->page_mkwrite for gfs2. It ought to return 0 so that the effect is the
same as if the page was truncated at any of the other points at which
the page_lock is dropped. This will result in the restart of the whole
page fault path. If it was due to a real truncation (as opposed to an
invalidate because we let a glock go) then the ->fault path will pick
that up when it gets called again.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
---

diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
index d7f4726ae0..f4842f2548 100644
--- a/fs/gfs2/ops_file.c
+++ b/fs/gfs2/ops_file.c
@@ -394,6 +394,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct page *page)
 	last_index = ip->i_inode.i_size >> PAGE_CACHE_SHIFT;
 	if (page->index > last_index)
 		goto out_unlock_page;
+	ret = 0;
 	if (!PageUptodate(page) || page->mapping != ip->i_inode.i_mapping)
 		goto out_unlock_page;
 	if (gfs2_is_stuffed(ip)) {