From owner-freebsd-fs@freebsd.org Thu Jul 23 05:46:03 2015 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 120369A6183 for ; Thu, 23 Jul 2015 05:46:03 +0000 (UTC) (envelope-from simon.brugger@gmail.com) Received: from mail-qk0-x231.google.com (mail-qk0-x231.google.com [IPv6:2607:f8b0:400d:c09::231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D6C9218B1 for ; Thu, 23 Jul 2015 05:46:02 +0000 (UTC) (envelope-from simon.brugger@gmail.com) Received: by qkfc129 with SMTP id c129so124638447qkf.1 for ; Wed, 22 Jul 2015 22:46:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=BqApJ77jT+BGIDrlBwLPRWS/cb08rcy4cNHsew1kAyI=; b=A6VcImJY0BaXPlrGwqXP29d4QNxaD2rNRj/DMnjwr2Fmvl8hNP7Jcr5rDQNBtYqDuj PI3fPwyBxfTiLkkb2tswJCXRjbeeLA7QZycXzJ80ZzDqCkR4cagOD7hej1OChreemH+6 +mOHOfbwE2ePN4cylarUlc7op7jgsj2O3kenYQLe5oSQH51JL996qOX1x2uazdm6AArp 1b0CylIspW+rbJBs5WYJcetHA+qpLODtSigN7BUrMI+9RkHGm0BgalhLs+mEaxXYEXo1 2lEPz1JnIUbRS40QInJzEUSXUxz6zUW3fyvJEDA7GLik9cxj3V3daUrXBDpIchHeozVZ eoCQ== MIME-Version: 1.0 X-Received: by 10.140.234.10 with SMTP id f10mr5543192qhc.11.1437630361951; Wed, 22 Jul 2015 22:46:01 -0700 (PDT) Received: by 10.140.39.202 with HTTP; Wed, 22 Jul 2015 22:46:01 -0700 (PDT) Date: Wed, 22 Jul 2015 22:46:01 -0700 Message-ID: Subject: Need help to understand inodes in FAT implementation From: Simon Brugger To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Jul 2015 05:46:03 -0000 The FAT filesystem is a design from Microsoft and the whole Windows universe. As you probably know, FAT does not support Inodes like ext3 or other UNIX/LINUX filesystem. The FreeBSD kernel provide a FAT filesystem driver but I've problems to understand the code and need help for answering the following questions: - Inodes must be generated on the fly by file access. When exactly does this happened? - How does FreeBSD generate Inodes? - How does the kernel FAT driver manage the file descriptors? Thank you very much for your help.