Re: silent semantic changes with reiser4

Felipe Alfaro Solana
2004-08-26T14:39:45Z

On Thursday 26 August 2004 15:59, Spam wrote:

> Backup to me is a special case, not simply a copy of files, but also
> retaining all the extra data, info, attributes, etc, that comes with
> the file.
>
> Enabling support to have all of this extra stuff below the
> application level it will be possible to retain everything even
> though applications do not support them.
>
> Backup tools, however, must know about these new features to be able
> to backup them. And so will every tool that directly accesses the
> filesystem instead of using the OS API for it.

Thus, this kind of metadata API must be made accessible through the VFS layer,
if we want to make it FS-independent (not tied to Reiser4). If the real FS
does not support metadata operations, just ignore them (much like in ISO9660
ignoring write operations).

> And from I learned in an earlier message, tools like cp actually
> work on the fs level and themselves move the data to the new file
> instead of letting the OS handle it. This seem to me as it could
> be dangerous and could also prevent any kind of enhancements to the
> FS unless every tool like cp is patched.

I still don't understand why a copy_file() syscall is still missing.