Subject: Re: FFS journal
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Pawel Jakub Dawidek <pjd@FreeBSD.org>
Date: 07/09/2006 12:02:27
Content-Type: text/plain; charset=iso-8859-2
On Tue, Jul 04, 2006 at 02:27:11PM -0400, der Mouse wrote:
> >>> If an application unlinks a file which is opened, the file is not
> >>> deleted until it is closed, until that it exists as unnamed. [...]
> >> There is one way in which it can be a problem without journaling: if
> >> the filesystem is made read-only after the unlink and before the
> >> close. [...]
> > This one could be solved by deleting the file on disk when the
> > filesystem is made read-only, I think.
> That will "solve" the "problem" of the file remaining. It will not,
> however, preserve the long--standing Unix semantics of continuing to
> use open-but-unlinked files.
> Now, one could decree that converting a RW filesystem to RO includes
> the destruction of any such files. But it seems better to me to leave
> them unlinked and instead make sure the filesystem is not marked clean.
Not sure about NetBSD, but in FreeBSD you can't remount file system
read-only if there is a process which holds deleted object open.
Pawel Jakub Dawidek http://www.wheel.pl
FreeBSD committer Am I Evil? Yes, I Am!
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