[PATCH] r/o bind mounts: monitor zeroing of i_nlink

Some filesystems, instead of simply decrementing i_nlink, simply zero it
during an unlink operation.  We need to catch these in addition to the
decrement operations.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index e40c95e..7316332 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -876,7 +876,7 @@
 		udf_warning(inode->i_sb, "udf_rmdir",
 			"empty directory has nlink != 2 (%d)",
 			inode->i_nlink);
-	inode->i_nlink = 0;
+	clear_nlink(inode);
 	inode->i_size = 0;
 	inode_dec_link_count(inode);
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_fs_time(dir->i_sb);