Linus Torvalds (torvalds@linux-foundation.org) on 1/28/09 wrote:
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>It has nothing to do with "metadata". It is all about
>any data.
>
>If you move data around, you'd better be conscious about
>it. If you're not, you're going to inevitably give people
>information that you didn't mean to give.

This is EXACTLY the problem which people face with ANY sort of metadata being associated with ANY file. Your argument starts off with a very nice criteria case of, "any data not explicitly visible to the user is a security hazard," then go on to close your eyes and shove your fingers in to your ears when I explain how this is a problem with virtually any sort of metadata, whether it's stuck in file headers, wrapped in to folders, inserted in to a xattrs, or shoved in to a database.

Twice. I've explained this twice, which you blissfully ignore as you type your essays, and then you accuse me of not responding to your points. I've explained how extended attributes provide a user with a one-stop shop method of wiping-out metadata if they want, but you're still busy arguing that they're going to be more painful for the user than the Watergate tapes were to Nixon.

>Don't be silly. If the metadata is in the file itself,
>the user will see it. It's about whether it is
>something that is agreed upon by the file format or not.
>It's not just hidden and unaware by the users of the file.

Oh, I see. The user always knows the file format! The user is always aware of metadata inside of a transmitted file. Now who's being silly? Look up the Cat Schwartz Photoshop incident for a glimpse in to reality.

But, I understand that you aren't thinking about real users. You're thinking about the "system software writers." Here's an idea: write a function called xattrwipe(). Now it's trivial to wipe all xattrs from all files leaving a system. Try doing that for everything wrapped inside of DOC, PDF, JPG, MOV, MP4, or any other file type that sticks metadata inside of structured file headers.

>You also ignored all my other issues, as if my only
>reason for telling you EA's were bad were security.

You also ignored the questions I posed at the end of my messages, but I'll try to touch on any point which I didn't explicitly address:

- I'd expect xattrs to be respected by NFS
- I misread your point about how editors would throw away metadata because they create new files at save. This is a big implementation problem.