Subject: Re: FFS journal
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Pavel Cahyna <pavel.cahyna@st.mff.cuni.cz>
List: tech-kern
Date: 07/04/2006 20:50:39
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.

Why couldn't the file continue to be used, even if it is deleted on disk?
Remember, the filesystem is now RO, so nothing can reuse the freed data and
metadata for another purpose.

Pavel