On Thu 12-01-12 12:53:35, Andreas Dilger wrote:

On 2012-01-11, at 6:20 PM, Jan Kara wrote:

quoted

/**
+ * sb_start_write - drop write access to a superblock
+ * @sb: the super we wrote to
+ *
+ * Decrement number of writers to the filesystem and wake up possible
+ * waiters wanting to freeze the filesystem.
+ */
+void sb_end_write(struct super_block *sb)
+{
+#ifdef CONFIG_SMP
+	this_cpu_dec(sb->s_writers);
+#else
+	preempt_disable();
+	sb->s_writers--;
+	preempt_enable();
+#endif
+	/*
+	 * Make sure s_writers are updated before we wake up waiters in
+	 * freeze_super().
+	 */
+	smp_mb();
+	if (waitqueue_active(&sb->s_writers_wait))
+		wake_up(&sb->s_writers_wait);
+	rwsem_release(&sb->s_writers_lock_map, 1, _RET_IP_);
+}

Since this function is needed for calling __block_page_mkwrite(), which is
EXPORT_SYMBOL(), both sb_start_write() and sb_end_write() themselves need
to be EXPORT_SYMBOL().

  Good point. Fixed. Thanks.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR