GFS2: Increase i_writecount during gfs2_setattr_size

This patch calls get_write_access in a few functions. This
merely increases inode->i_writecount for the duration of the function.
That will ensure that any file closes won't delete the inode's
multi-block reservation while the function is running.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 1dc9a13..93b5809 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1286,17 +1286,26 @@
 	if (ret)
 		return ret;
 
+	ret = get_write_access(inode);
+	if (ret)
+		return ret;
+
 	inode_dio_wait(inode);
 
 	ret = gfs2_rs_alloc(GFS2_I(inode));
 	if (ret)
-		return ret;
+		goto out;
 
 	oldsize = inode->i_size;
-	if (newsize >= oldsize)
-		return do_grow(inode, newsize);
+	if (newsize >= oldsize) {
+		ret = do_grow(inode, newsize);
+		goto out;
+	}
 
-	return do_shrink(inode, oldsize, newsize);
+	ret = do_shrink(inode, oldsize, newsize);
+out:
+	put_write_access(inode);
+	return ret;
 }
 
 int gfs2_truncatei_resume(struct gfs2_inode *ip)