From owner-freebsd-doc@FreeBSD.ORG Sat May 24 21:50:01 2014 Return-Path: Delivered-To: freebsd-doc@smarthost.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 3E032D9 for ; Sat, 24 May 2014 21:50:01 +0000 (UTC) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 2975120EA for ; Sat, 24 May 2014 21:50:01 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.8/8.14.8) with ESMTP id s4OLo1x5057693 for ; Sat, 24 May 2014 21:50:01 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.8/8.14.8/Submit) id s4OLo1kl057680; Sat, 24 May 2014 21:50:01 GMT (envelope-from gnats) Date: Sat, 24 May 2014 21:50:01 GMT Message-Id: <201405242150.s4OLo1kl057680@freefall.freebsd.org> To: freebsd-doc@FreeBSD.org Cc: From: Benjamin Kaduk Subject: Re: docs/188214: Manpage for fsck(8) doesn't say what happens when no -t or -T Reply-To: Benjamin Kaduk X-BeenThere: freebsd-doc@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Documentation project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 May 2014 21:50:01 -0000 The following reply was made to PR docs/188214; it has been noted by GNATS. From: Benjamin Kaduk To: Tom Rhodes Cc: Allan Jude , bug-followup@freebsd.org Subject: Re: docs/188214: Manpage for fsck(8) doesn't say what happens when no -t or -T Date: Sat, 24 May 2014 17:42:47 -0400 (EDT) On Sat, 24 May 2014, Tom Rhodes wrote: > So, in theory, an attempt to parse /etc/fstab would be > an attempt to detect the type; however, my quick glance > at the code showed no real parsing of fstab. But in > my case, I followed to both the T and t flags, and just > glanced at what was done would they not be specified. > That was really as far as I got, and I attempted to use > very generic language in case it only does one, or the > other, or both. :) When passed no device or path arguments, fsck just checks everything from the fstab; that's not very interesting for this question. Given a path argument and no type argument to use, fstab is parsed using getfsfile() or getfsspec() around line 204 of fsck.c. This will fail (well, barring special circumstances) if the argument is instead a device name. Given a device name argument and no type argument to use, after the fstab check above, fsck opens the device and uses ioctl() to get the disklabel and does some magic to grab the fstype from it. (See getfslab(), in fsck.c) So, I think there is a fair bit of autodetection that is attempted. -Ben