From: Bob Peterson <rpeterso@redhat.com>
Date: Fri, 1 Feb 2013 17:03:02 +0000 (-0500)
Subject: GFS2: Get a block reservation before resizing a file
X-Git-Tag: v3.7.10~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=496064cd2a5ec740671a522e5fa154ce91dfb012;p=thirdparty%2Fkernel%2Fstable.git

GFS2: Get a block reservation before resizing a file

commit d2b47cfb26fe06002b8011707baac71a9ae8166f upstream.

This patch allocates a block reservation structure before growing
or shrinking a file. Without this structure, the grow or shink code
can reference the bad pointer.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1fd3ae237bdde..8f331e07177c8 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1240,6 +1240,10 @@ int gfs2_setattr_size(struct inode *inode, u64 newsize)
 
 	inode_dio_wait(inode);
 
+	ret = gfs2_rs_alloc(GFS2_I(inode));
+	if (ret)
+		return ret;
+
 	oldsize = inode->i_size;
 	if (newsize >= oldsize)
 		return do_grow(inode, newsize);