GFS2: Clear dirty bit at end of inode glock sync

The dirty bit can get set during the inode glock sync. Its too
complicated to change that at the moment, so this is the quick
fix - to clear the bit again at the end of the function.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glops.c

@@ -156,6 +156,12 @@ static void inode_go_sync(struct gfs2_glock *gl)
 	error = filemap_fdatawait(metamapping);
 	mapping_set_error(metamapping, error);
 	gfs2_ail_empty_gl(gl);
+	/*
+	 * Writeback of the data mapping may cause the dirty flag to be set
+	 * so we have to clear it again here.
+	 */
+	smp_mb__before_clear_bit();
+	clear_bit(GLF_DIRTY, &gl->gl_flags);
 }
 
 /**