From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Koss Subject: dummy fs Date: Wed, 11 Jan 2006 20:18:57 +0300 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from uproxy.gmail.com ([66.249.92.195]:32215 "EHLO uproxy.gmail.com") by vger.kernel.org with ESMTP id S1751467AbWAKRS7 convert rfc822-to-8bit (ORCPT ); Wed, 11 Jan 2006 12:18:59 -0500 Received: by uproxy.gmail.com with SMTP id s2so55445uge for ; Wed, 11 Jan 2006 09:18:57 -0800 (PST) To: kernelnewbies@nl.linux.org, linux-fsdevel@vger.kernel.org Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Hello. I want implement educational file-system for Linux. I suppose it would be very simplified UFS (for example, with such limitations like: size of file <=8K, length of name <20 characters and so on). The main goal is simplicity, small size of implementation and space for speedup improvements. 1)May be some one hear about such for Linux 2.6 ? 2)Currently I'm investigating how "truncate" method should works on the filesystem layer. Is any description how it should works? I mean, as I understand first I should truncate page cache (block_truncate_page?), what about "buffer_head" which now not belong to my file and may be used by another process at the same time? 3)As I see sb_find_get_block return "buffer_head", with b_count==2, (if nobody before use this "buffer_head"), is it right behavior? Should I call two time brelse to free "buffer_head", which I get using sb_find_get_block? 4)Is there set of tests to check work of ordinary Unix file-system? For example: one process creates files, and another check using (readdir) is all right, one open file for writing, another open the same file for reading... etc