Re: VFS 64-bit clean

Itai Nahshon (nahshon@actcom.co.il)
Wed, 25 Feb 1998 22:37:48 +0200


Theodore Y. Ts'o wrote:
>
> B-tree directories can be cleanly added to ext2. The hard part is
> writing code that implements B-trees cleanly in the kernel (including
> handling the case of B-tree splits in the SMP case). Once we have this

IMHO B-tree joins may be more difficult but not that necessary.

> code written, we then simply make actual *use* of B-tree directories to
> be optional, and that makes for an easy transition path.
>
> I know how to handle the integration and backwards compatibility issues;
> and honestly, they're not hard. Handling the B-tree code cleanly and
> robustly is really the hard part of the problem.
>

What does Posix say about directory operations if the directory is
changed (telldir, seekdir and readdir)? It will be difficult to
guarantee
any kind of consistency.
Even if posix does not require anything, a program that reads
a directory must be able to resynchronize to the next directory entry
if the directory was modified beneath it.

> - Ted

-- 
Itai Nahshon   nahshon@actcom.co.il
        Also   nahshon@vnet.ibm.com

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