Messages in this thread |  | | | Date | Tue, 13 Jul 2004 01:09:50 -0700 | | From | Chris Wedgwood <> | | Subject | Re: XFS: how to NOT null files on fsck? |
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On Tue, Jul 13, 2004 at 07:25:29AM +0000, Anton Ertl wrote: > A secure FS must ensure that other people's deleted data does not > end up in the file. AFAIK FSs don't record owners for free blocks, > so they can only ensure this by zeroing the blocks.
How can free blocks have an owner? They wouldn't be free then.
> So I doubt that you will see any different behaviour from an FS that > keeps only meta-data consistent and writes meta-data before data.
You do, some fs' will return stale data.
> It's too hard to fix the applications, since there is no easy way to > test that they are really fixed.
No, it's not hard to fix the applications and it's easy to tell if they are fixed.
> Also, the number of applications is much higher than the number of > file systems.
You don't fix all applications, only ones where data is critical and their handling of it is poor. MTAs like postfix don't have a problem for example, they are generally written well.
> The file system should provide something that I call in-order > semantics, i.e., that the disk state always represents an existing > (possibly old) logical state of the FS, not some state that never > existed, or some existing state with missing data.
ext3 and reiserfs have what amounts to this as an option right now. It has some performance implications but I'm told works great.
I don't think the current XFS behaviour is undesirable or broken.
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