From mboxrd@z Thu Jan 1 00:00:00 1970 From: Namhyung Kim Subject: A question on block_prepare_write() Date: Sat, 23 Oct 2010 22:44:42 +0900 Message-ID: <1287841482.1681.36.camel@leonhard> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: LKML To: linux-fsdevel Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hello, I see block_prepare_write() has local variable wait[2] to keep track of buffer_heads which are not up-to-date. But I'm wondering how it could be guaranteed there will be no more than 2 such buffer_heads? Is there any restriction on the usage of the function? Using MAX_BUF_PER_PAGE instead of the magic number 2 is just useless? I couldn't find any comments or documentation on this. Any of your comments would be greatly appreciated. TIA. :-) -- Regards, Namhyung Kim