From owner-freebsd-current@FreeBSD.ORG  Wed Apr  6 05:22:56 2005
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To: Robert Watson <rwatson@FreeBSD.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Tue, 05 Apr 2005 23:55:27 BST."
             <20050405235414.D81173@fledge.watson.org> 
Date: Wed, 06 Apr 2005 07:22:49 +0200
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cc: current@FreeBSD.org
Subject: Re: Panic on mount with write-locked USB media (umass) 
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In message <20050405235414.D81173@fledge.watson.org>, Robert Watson writes:

>> There are two ways that a filesystem correctly could handle a R/O media:
>>
>> 1.	Fail with EROFS unless asked t mouned read-only
>>
>> 2.	Silently downgrade th emount to read-only.
>>
>> I personally prefer the first because that way a script does not have to 
>> check if it got the mount it wanted or not.
>
>In general, I agree, but this will de-POLA the following command:
>
>     mount -t cd9660 /dev/acd0 /cdrom

Not really.

The cd9660 filesystem can never be mounted R/W, it always mounts
R/O by default so it will still DTRT.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.